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Home My WebLink AboutAPA4155pt3?lee eUed o5 ~ rut tlee eu4tett ~ o5 tlee ~ 7<~~~.~ by Duane A. Klarich Jim Thomas Water Quality Bureau Montana Department of Health and Environmental Sciences TECHNICAL REPORT NO. 3 conducted by the Water Resources Division Montana Department of Natural Resources and Conservation 32 S. Ewing Helena, MT 59601 Bob Anderson, Project Administrator Shari Meats and Dave Lambert, Editors for the Old West Regional Commission 228 Hedden Empire Building B.i 11 i ngs, MT 59101 Kenneth A. Blackburn, Project Coordinator July 1977 1730 K Street, H. W. Suite 426 The Old West Regional Commission is a Federal-State pannership designed to solve regional economic problems and stimulate orderly economic growth in the states of Montana. Nebraska, North Dakota. South Dakota and Wyoming. Established in 1972 under the Public Works and Economic Development Act of 1965, it is one of seven identical commissions throughout the country engaged in formulating and carrying out coordinated action plans lor regional economic development. COMMISSION MEMBERS State Cochairman Gov. Thomas L. Judge of Montana Alternate: Dean Hart Federal Cochairman George D. McCarthy State Members Gov. Edgar J. Herschler of Wyoming Alternate: Steve F. Freudenthal Gov. J. James Exon of Nebraska Alternate: Jon H. Oberg Gov. Arthur A. Link of North Dakota Alternate: Woody Gagnon Gov. Richard F. Kneip of South Dakota Alternate: Theodore R. Muenster COI·IMISSION OFFICES 201 r4ain Street Suite D Washington, D. C. 20006 202/967-3491 Rapid City, South Dakota 57701 605/348-6310 Suite 228 Heddon-Empire Building Billings, Montana 59101 406/657-6665 i i \ . ) j I I I ' \ I ! FOREWORD The Old West Regional Commission wishes to express its appreciation for this report to the Montana Department of Natural Resources and Conservation, and more specifically to those Department staff members who participated · directly in the project and in preparation of various reports, to Dr. Kenneth A. Blackburn of the Commission staff who coordinated the project, and to the subcontractors who also participated. The Yellowstone Impact Study was one of the first major projects funded by the Commission that was directed at investigating the potential environmental impacts relating to energy develop- ment. The Commission is pleased to have been a part of this important research. George D. McCarthy Federal Cochairman FIGURES. TABLES . ABBREVIATIONS USED IN THIS REPORT PREFACE. The River . . The Conflict. The Study . . Acknowledgments INTRODUCTION Purpose Scope Measurement. Parameter Groups Water Quality Index. Description of Study Area Drainage Basins Examined and Associated Streams. METHODS ............ · . Data Sources and Chemical Analyses .. United States Geological Survey. Montana Water Quality Bureau . . . . . . . Miscellaneous Sources and Other Investigations Water Quality Reference Criteria ........ . Rationale .................. . Montana Stream and Water-Use Classifications . Montana Water Quality Criteria ..... Drinking Water and Surface Public Supply Criteria. Agricultural Criteria ...... . Biological Criteria ...... . Tabular and Statistical Considerations. Impacts of Water Withdrawals ..... . Description of Methods ..... . WATER QUALITY PROBLEMS IN THE YELLOWSTONE RIVER BASIN. Introduction ......... . Mining ........... . Drainage Water ..... . Erosion and Sedimentation. Leaching . . . . . . . Miscellaneous . . . . . . Control of Wastewaters From Mining iv vii X XX 1 1 1 3 4 5 5 5 6 B 11 12 12 19 19 19 24 31 32 32 33 34 36 36 40 49 54 54 63 63 63 63 63 64 65 66 Power Plants. . . . . . . . . . . . . . . . . . . . . . . . Synthetic Fuel Plants . . . . . . . . . . . . . . . . . . . Control of Wastewaters from Coal-Conversion Facilities Municipal and Industrial Wastes .......... . Municipal Waste1~ater ............. . Industrial Wastewater ............. . Control of Municipal and Industrial Wastewaters. Irrigation Return Flow. . . . . .... . Control of Wastewater from Irrigation .. . Nonpoint Sources of Pollution ........ . Control of Pollution from ilonpoint Sources Slurry Pipelines. EXISTING SITUATION ..... . Yellowstone River Mainstem Above the Mouth of the Clarks Fork . . . 67 70 71 73 73 75 76 77 79 80 81 81 83 Yellows tone River. . . . . . . . . 83 Yellowstone River--Clarks Fork River to Bighorn River 94 Yellows tone Mains tern . . . . 94 i·liscellaneous Tributaries. . . 107 Pryor, Arrow, and Fly Creeks . 108 Little Bighorn River Drainage . . . 114 Little Bighorn River Mainstem. 114 Tributary Streams. . . 119 Bighorn River Drainage. . . . . . . 122 Bighorn River Mainstem . . . . 122 Beauvais Creek . . . . . . . . 129 Other Tributaries Above Hardin 134 Tullock Creek. . . . . . . . . 139 Yellowstone River--Bighorn River to Powder River. 141 Yellowstone Mainstem . . . . . 141 Sarpy Creek Drainage . . . . . 157 Armells Creek Drainage . . . . 163 Miscellaneous Tributaries and Sunday Creek 172 Rosebud Creek Drainage . . 177 Tongue River Drainage. . . . . . . . 188 Powder River Drainage. . . . . . . . 225 Yellowstone River--Powder River to Montana-North Dakota Border. 244 Yellowstone Mainstem . . 244 O'Fallon Creek Drainage. 253 Tributary Streams. . 257 SUMMARY OF EXISTING SITUATION. . 261 Yellowstone River Mainstem. 261 TDS Concentrations . . 261 Changes in Chemistry . 261 Changes in Water Quality 264 Associated Drainages. . 265 TDS Concentrations 265 Salinity . . . . 267 PH Values. . . . . 267 Temperature .. : . 267 Dissolved Oxygen . 268 Organic Pollution. 268 v Chemical Composition ... Turbidities, TSS, and Flow Water Quality Degradation. Water Quality Index . . . . . . Potential Water Quality Problems in Relation to Water Use IMPACTS OF WATER WITHDRAWALS Projections of Future Use ... Potential Water Quality Effects by Subregion. Upper Yellowstone Basin. Bighorn Subbasin ..... Mid-Yellowstone Subbasin . Tongue Subbasin. . . . . . Powder River Subbasin ... Lower Yellowstone Subbasin Sensitivity Analyses .. . Introduction ... . Distribution of Salt Return. Salt Pickup ... Exogenous Influences. Dryland Farming .. . Saline Seep .... . Silviculture ... . Noncoal Mineral Extraction Wyoming Activities .... National and State Policies. Recommendations ........ . APPENDIX A. Projections of Future Use LITERATURE CITED .... v; 268 269 270 270 272 305 305 305 305 311 317 327 343 353 362 362 362 365 371 371 371 371 372 372 372 372 375 383 1. 2. Primary and Secondary Study Areas and Associated Subregions. Simplified Diagram of Water and Salt Movement 3. Median TDS Concentrations at Various Sites on the Yellowstone River During Four Seasons of the Year. 4. Median TSS Conce-ntrations at Various Sites on the Yellowstone River During Four Seasons of the Year. 5. Average Monthly TDS Concentrations in the Yellowstone 6. 7. 8. 9. 10. 11. River at Billings at 50th Percentile Values ..... . Average Monthly TDS Concentrations in the Yellowstone River at Billings at 90th Percentile Values ..... . Average Monthly TDS Concentrations in the Bighorn River near St. Xavier, 1968-74 0 0 0 0 0 0 0 0 Average Monthly TDS in the Bighorn River near Bighorn at 50th Percentile Values ...... 0 0 0 0 0 0 Average Monthly TDS Concentrations in the Bighorn River near Bighorn at 90th Percentile Values. 0 0 0 Discharge Relationship between the Yellowstone River near Miles City and the Yellowstone River near Sidney ..... TDS Relationship between the Yellowstone River near Miles City and the Yellowstone River near Sidney ....... . 12. Comparison of Historical and Simulated TDS Concentrations in the Yellowstone River near Miles City at 50th Percentile 0 0 0 0 - 0 13 55 262 266 310 310 312 316 316 318 320 Values ................................. 324 13. 14. Comparison of Historical and Simulated TDS Concentrations in the Yellowstone River near Miles City at 90th Percentile Values .......................... . Comparison of Historical and Simulated TDS Concentrations in the Tongue River near Miles City at 50th Percentile Values • 15. Comparison of Historical and Simulated TDS Concentrations in 325 333 the Tongue River near Miles City at 90th Percentile Values , ..... 334 16. Comparison of TDS Concentrations in the Tongue River at Miles City Computed from Records at.Miles City and the State Border, Assuming Complete Mixing in the Reservoir, and Using the Low Level of Development at 50th Percentile Values ............. 336 vii 17. Comparison of TDS Concentrations in the Tongue River at Miles City Computed from Records at Miles City and the State Border, Assuming Complete Mixing in the Reservoir, and Using the Low Level of Development at 90th Percentile Values. . ... 337 18. Comparison of TDS Concentrations in the Tongue River at Miles City Computed from Records at Miles City and the State Border, Assuming Complete Mixing in the Reservoir, and Using the Intermediate Level of Development at 50th Percentile Values . . . . . . . . . . . . . . . . . . . . ..... 338 19. Comparison of TDS Concentrations in the Tongue River at Miles City Computed from Records at Miles City and the State Border, Assuming Complete Mixing in the Reservoir, and Using the Intermediate Level of Development at 90th Percent i1 e Va 1 ues . . . . . . . . . . . . . . . . . . . . . . . . . . 339 20. Comparison of TDS Concentrations in the Tongue River at Miles City Computed from Records at Miles City and the State Border, Assuming Complete Mixing in the Reservoir, and Using the High Level of Development at 50th Percentile Values . . . . 340 21. 22. 23. 24. 25. Comparison of TDS Concentrations in the Tongue River at Miles City and the State Border, Assuming Complete Mixing in the Reservoir, and Using the High Level of Development at 90th Percentile Values . . . . ....... . Effects of Reservoir Storage on TDS Concentrations in the Powder River near Moorhead. . . . ....... . Effects of Active Storage Level on ·Average Monthly TDS Concentrations in the Powder River near Locate ..... Average Monthly TDS Concentrations in the Powder River near Locate at 50th Percentile Values with 1,150,000 af Storage. Average Monthly TDS Concentrations in the Powder River at Locate at 90th Percentile Values with 1,150,000 af Storage. 26. Comparison of Historical and Simulated TDS Concentrations in the Yellowstone River near Sidney at 50th Percentile Flow 341 345 346 349 350 Va 1 ues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358 27. Comparison of Historical and Simulated TDS Concentrations in the Yellowstone River near Sidney at 90th Percentile Flow Values .............. . 28. Comparison of so 4 and TDS Concentrations in the Yellowstone River near Sidney .................... . 29. Effect on TDS Concentrations of Changing the Monthly Distri- bution of Salt Return from Irrigation in the Tongue River near 359 360 Miles City, Using the Intermediate Level of Development . . . . 363 Vi i i ~ I 30. Effects on TDS Concentrations of Changing the Monthly Distribution of Salt Return from Irrigation in the Tongue River near Mi 1 es City, Using the High Leve 1 of Development. . .. . . . .3fA 31. 32. Effects on TDS Levels of Adjusting the Monthly Distribution of Salt Return from Irrigation in the Yellowstorre River near Sidney, Using the Intermediate Level of Development .. Effects on TDS Levels of Adjusting the Monthly Distribution of Salt Return from Irrigation in the Yellowstone River near Sidney, Using the High Level of Development 3f.f 3[7 33. Water Temperatures Observed on the Lower Yellowstone Project, 1971 . . . . . . . . . . . . . . . . . . . . . .... 368 34. Effects of Salt Pickup Rate on TDS Concentrations in the Yellowstone River near Sidney, Using the lnterm~diate Level of Deve 1 opment at 50th Percent i 1 e Flows . . . . . . . . . . . . . . . 369 35. Effects of Salt Pickup Rate on TDS Concentrations in the Tongue River near Miles City, Using the Intermediate Level of Development at 50th Percentile Flows ............... 370 ix 1. 2. Methods of Analysis .................... . Water Quality Monitoring Stations in the Yellowstone River Basin of Montana Operated by the USGS between September 1965 arid September _197 4 . . . . . . . . . . . . . . . . . . 3. 4. Water Quality Monitoring Stations in Operation between October 1965 and September 1974 with Published Records Maintained by the USGS on the Yellowstone River and in the Yellowstone River Basin of Montana below this Confluence . . . . . . . . . . . . . . . . . . . . . . Water Quality Monitoring Stations Maintained by the USGS in the Study Area for Which Information is Being or Has Been Obtained on Several Parameters ........ . 5. Additional USGS Water Quality Monitoring Sites in Operation During 1976 Which Had No Published Records as of July 1976 .................. . 6. Streams Sampled by the State WQB in the Secondary and Primary Inventory Areas of the Yellowstone River Basin Since the Summer of 1973 . . . . . . 7. Hardness and salinity classification 8. Montana Water Quality Criteria ... 9. Selected Water Quality Criteria and Standards for Drinking Water and Public Surface Supply ........ . 10. Water Quality Criteria for Stock as Set Forth by the California Water Quality Control Board ...... . 11. Water Quality Criteria Recommended by the EPA for Stock. 12. Threshold Salinity (TOS) Levels for Farm Animals .... 13. Use and Effect of Saline Water on Livestock and Poultry. 14. Montana Salinity Classification of Waters ....... . . 15. Summary Classification of Irrigation Waters and Associated Water Quality Criteria and Recommended Maximum Concentrations of Trace Elements for All Plants in Continuously Used 16. Irrigation Waters ................. . Recommended Maximum Concentrations of Trace Elements for All Plants in Continuously Used Irrigation Waters .. X 7 21 22 23 25 28 33 35 37 . 38 38 39 39 39 41 42 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. Relative Tolerances of Various Crops and Forage to Salinity and Boron ................ . Impact Reference System for Turbidity and Suspended Sediment . . . . . . . . . . . . . . . . . . . . . Recommended Maximum Concentrations of Trace Elements for Freshwater Aquatic Life and for Marine Aquatic Life .. Sample Calculation of TDS in the Tongue River at Miles City Assuming a Low Level of Development .... Quantity and Nature of Major Wastewater Streams from 270 x 1 o6 SCF /day P.l ant Proposed for Wyoming. . . . . Physical Parameters of Waters from Armells Creek and Montana Power Company Ponds in and near Colstrip ... Summary of Salt and Water Discharges in the Yellowstone River Basin, 1944-1973 ........... . Nonpoint Waste Sources and Characteristics in the Yellowstone River Basin ......... . Summary of the Physical Parameters Measured in the Yellowstone River at Corwin Springs ....... . Summary of the Physical Parameters Measured in the Yellowstone River near Livingston ..... Summary of the Physical Miscellaneious Sites on Big Timber and Columbus Parameters Measured on the Yellowstone River Between 28. Summary of the Physical Parameters Measured in the Yellowstone River at Laurel Above the Clarks Fork 29. 30. 31. 32. 33. Yellowstone River ................ . Summary of Trace Element and Miscellaneous Constituent Concentrations Measured in the Yellowstone River above the Confluence of the Clarks Fork Yellowstone River ... Summary of the Physical Parameters Measured in the Yellowstone River near Laurel below the Confluence of the Clarks Fork Yellowstone River (Duck Creek Bridge) Summary of the Physical Parameters Measured in the Yellowstone River at Billings ....... . Summary of the Physical Parmeters Measured in the Yellowstone River at Huntley ..... Summary of the Physical Parameters Measured in the Yellowstone River at Custer ........... . xi 43 47 50 58 71 74 78 80 84 85 86 87 92 96 97 98 99 34. 3S. 36. 37. Proportions of sodium and sulfate in the Yellowstone River below Laurel ............... . BODs Values and Median TOC and COD Concentrations above Laurel and in the Laurel-to-Custer Reach ..... Summary of Trace Element and Miscellaneous Constituent Concentration Measured in the Yellowstone River between Laurel and Custer . . . . . . . . . . . . Median TR and Dissolved Concentrations of Sr, Fe, and Mn below Corwin Springs .......... . 38. Summary of the Physical Parameters Measured in Spring, 39. 40. 41. 42. 43. Duck, and Canyon Creeks (Minor Yellowstone Tributaries), and in East Fork Creek (a Minor Tributary to Pryor Creek) . Summary of Trace Element and Miscellaneous Constituent Concentrations Measured in Various Secondary Streams in the Yellowstone Drainage between Laurel and Custer Summary of the Physical Parameters Measured in the Pryor Creek Drainage and in Arrow Creek near Ballantine-Worden. Summary of the Physical Parameters Measured in Fly Creek at Pompeys Pi 11 ar . . . . . Summary of the Physical Parameters Measured in the Little Bighorn River near Wyola. Summary of the Physical Parameters Measured in the Little Bighorn River near Hardin . . 44. Summary of Trace Element and Miscellaneous Constitutent Concentrations Measured in the Little Bighorn River Drainage. 45. Summary of the Physical Parameters Measured in Various Tributaries to the Little Bighorn River .. 46. Summary of the Physical Parameters Measured in the Bighorn River at St. Xavier . 47. Summary of the Physical Parameters 11easured in the Bighorn River near Hardin . 4B. Summary of the Physical Parameters Measured in the Bighorn 49. so. River at Bighorn. . Summary of Trace Element and Miscellaneous Constituent Concentrations Measured in the Bighorn River. . Summary of the Physical Parameters Measured in Beauvais Creek near St. Xavier (Bighorn River tributary) .... xii 100 103 104 106 108 110 111 112 llS 118 120 121 123 125 126 128 130 51. 52. 53. 54. 55. 56. 57. 58. Summary of Trace Element and Miscellaneous Constituent Concentrations Measured in Tributaries to the Bighorn River. Summary of the Physical Parameters Measured in Various Tributaries to the Bighorn River Summary of the Physical Parameters and Total Recoverab 1 e Meta 1 s Measured in Sage Creek near l1arren During the August-October Period Summary of the Physical Parameters and Trace Elements Measured in the Tullock Creek Drainage Summary of the Physical Parameters Measured in the Yellowstone River at Myers . . . Summary of the Physical Parameters Measured in the Yellowstone River near Forsyth Summary of the Physical Parameters Measured in the Yellowstone River near Miles City . Salinity Change Per River Mile in the Bighorn-to-Powder Segment . . . . . . . . . . . 59. Downstream Composition Changes on the Bighorn-to-Powder Reach of the Yellowstone River ......... . 60. Average May-October Warm-Weather Data for Sequential Sites 61. 62. 63. 64. 65. 66. 67. Summary of Miscellaneous Constituent and Trace Element Concentrations Measured in the Yellowstone River at Myers and near Forsyth . . . . . . . . . . . . . . . . . . . Summary of Miscellaneous Constituent and Trace Element Concentrations Measured in the Yellowstone River near Miles City .................... . Concentration Increases of TR and Dissolved Forms of Fe, Mn, and Sr in the Yellowstone River above Custer and at Myers, Forsyth, and Miles City ....... . Summary of the Physical Parameters Measured in the Upper Sarpy Creek Drainage near Westmoreland . . . . Summary of the Physical Parameters Measured in Sarpy Creek near Hysham ........ . Summary of Miscellaneous Constituent and Trace Element Concentrations Measured in the Sarpy Creek Drainage .. Summary of of Armells Colstrip . the Physical Parameters Measured in the East Fork Creek and Sheep Creek Tributary (One Sample) near • • • • • • • 0 • 0 • • • • • • • 0 0 0 • • • • • xiii . . . . . 132 135 138 140 144 145 146 147 150 150 153 154 156 158 160 162 164 68. Summary of the Physical Parameters Measured in the West Fork of Armells Creek near Colstrip ......... . 69. Summary of the Physical Parameters Measured in Armells Creek near Forsyth ........... ·. 70. Mean (Ca + Mg):Na and HC03:S04 Ratios from the Mouth and East and West Forks of Armells Creek ........ . 71. Summary of Miscellaneous Constituent and Trace Element Concentrations Measured in the Armells Creek Drainage. 72. Surr111ary of Trace Element Concentrations Measured in the Arme 11 s Creek Drainage . . . . . . . . . 73. Summary of Miscellaneous Constituent and Trace Element Concentrations Measured in Armells Creek near Forsyth. 74. 75. 76. 77. Trace Elements in Armells Creek Grouped According to their Maximum and Median, TR and Dissolved Concentrations in Relation to Water Quality Criteria .......... . Summary of the Physical Parameters Measured in Small Tributaries to the Yellowstone River between the Bighorn and Powder Rivers . . . . . . . . . . . . . . . . . . . Summary of the Total Recoverable Metals Measured Tributaries to the Yellowstone River between the and Powder Rivers ............. . in Small Bighorn Summary of the Physical Parameters Measured in Sunday Creek near Miles City .................. . 78. Summary of the Total Recoverable Metals Measured in Sunday Creek near Miles City. . . . . . . ..... 79. Summary of the Physical Parameters Measured in the Upper Reach of Rosebud Creek near Kirby-Busby. . . . .... 80. Summary of Total Recoverable Metals Measured in the Upper Reach of Rosebud Creek near Kirby-Busby ......... . 81. Low-Flow and High-Flow Levels of (Ca + Mg):NA, HC0 3 : S04 in Rosebud Creek. . . . . . . . . . . 82. Summary of the Physical Parameters Measured in Reach of Rosebud Creek near Colstrip ..... 83. Summary of the Physical Parameters Measured in Reach of Rosebud Creek near Rosebud . . . . . Ca :Mg, and 0 the Middle the Lower 84. Summary of f·1i see 11 aneous Constituent and Trace Element Concentrations Measured in the Middle and Lower Reaches of Rosebud Creek . . . . . . . . . . . . . . . . . . . . . . xiv 165 166 167 0 0 0 169 0 0 0 170 0 0 171 172 174 174 175 175 178 178 179 0 0 180 0 181 183 85. 86. 87 0 88. 89. 90. 91. 92. 93. 94. Seasonal Changes in Median TDS Concentrations between Low and High Flows in the Yellowstone River ......... . Summary of the Physical Parameters Measured in the Rosebud Creek Tributaries near Kirby, Busby, and Lame Deer Summary of the Total Recoverable Metals Measured in the Rosebud Creek Tributaries near Kirby, Busby, and Lame Deer Summary of the Physical Parameters Measured on Various Sites on the Tongue River near Decker (above the Tongue River Reservoir) .................... . Salinity Hazard for Irrigation from the Upper Tongue River Depending Upon Flow and Season . . . . . . . . . . . . . . Summary of the Physical Parameters Measured on Various Sites on the Tongue River near Birney (below the Tongue River Reservoir) .· . . . . . . . . . . . . . . . . . . . . . Summary of the Physical Parameters Measured on Various Sites on the Tongue River near Ashland-Brandenburg ..... Summary of Physical Parameters Measured in the Tongue River near Miles City. . . . . . . . . . . . . . . . Percentage of Temperature Readings in the Tongue River During the June-September Period, 1970-1974, Greater or Less Than a Particular Temperature. . ......... . Downstream Increases in TDS in the Tongue River between Birney and Miles City .... : .......... . 95. Ratios of Low-Flow Seasonal TDS Concentrations to Runoff TDS Levels in the Four Tongue Segments . , . . .... 96. Seasonal (Ca + Mg):Na and HC0 3 :S04 Ratios in the Tongue River. 97. 98. 99. 100. 101. Salinity Hazard for Irrigation in the Upper and Lower Tongue River . . . . . . . . . . . . . . . . . . . . . Summary of Miscellaneous Constituent and Trace Element Concentrations Measured in the Tongue River above Ashland, Montana. . . . . . . . . . . . . . . . . . . Sunmary of r~i scell aneous Constituent and Trace Element Concentrations Measured in the Tongue River below Ashland, Montana. . . . . . . . . . . . . . . . . . . . Summary of the Physical Parameters Measured in Small Streams in the Tongue River Drainage . . . . . . . ... Summary of Miscellaneous Constituent and Concentrations Measured in Small Streams River Drainage ............ . XV Trace Element in the Tongue 184 186 187 190 191 194 195 196 198 200 200 202 203 205 206 209 210 102. 103. 104. Summary of the Physical Parameters Measured in Hanging Woman Creek near Birney. . . . . . . ... Summary of Miscellaneous Constituent and Trace Element Concentrations Measured in Hanging Woman and Otter Creeks. Summary of the Physical Parameters Measured in Otter Creek at Ashland . . . . . ...... . 212 215 217 105. Effects of Hanging Woman and Otter Creeks Towards . 218 Increasing TDS Levels in the Tongue River below the Dam ..... . 106. Summary of the Physical Parameters Measured in the Pumpkin Creek Drainage .......... . 107. Summary of the t1iscellaneous Constituent and Trace Element Concentrations Measured in the Pumpkin Creek Drainage (mg/1) 108. log. 110. 111. 112. 113. 114. 115. Summary of the Physical Parameters Measured in the Powder River near Moorhead-Broadus: . . . . . . . . . . ... Summary of the Physical Parameters Measured in the Powder River near Locate-Terry. . . . . . . . . . . ... Calculated Percentage Increases in River from Miles City to below the Powder River .......... . TDS of the Yellowstone Confluence of the Percentage of Powder River Samples with TDS and SC Concentrations in Particular Ranges ..... . Summary of Miscellaneous Constituent and Trace Element· Concentrations Measured in the Powder River ..... . Calculated Percentage Increases.in TSS in the Yellowstone from near Miles City to below the Confluence of the Powder Summary of the Physical Parameters Measured in the Little Powder River near the Montana-Hyoming State Line and near Broadus . . . . . . . . . . . . . . . . . Summary of Miscellaneous Constituent and Trace Element Concentrations Measured in Tributaries to the Powder River 116. Summary of the Physical Parameters Measured in the Mizpah Creek Ora in age . . . . .. . . . . . . . . . . . . . . . . . 117. Summary of the Physical Parameters Measured on t~i scellaneous Sites on the Yellowstone River between Terry and Intake. 118. Summary of the Physical Parameters t~easured in ·the Yellowstone River near Sidney, Montana .... xvi 221 222 227 228 229 231 233 235 239 241 243 245 246 119. 120. 121. 122. 123. 124. Summary of Miscellaneous Constituent and Trace Element Concentrations f1easured in the Yellowstone River between Terry and near the Montana-North Dakota Border. . . Percentage Increases in TDS Concentrations and SC Levels Downstream in the Yellowstone River from Miles City to Sidney . . . . . . . . . . . . Summary of the Physical Parameters Measured in the O'Fallon Creek Ora i nage. . · . . . . . . . • Summary of Trace Element and Miscellaneous Constituent Concentrations Measured in the O'Fallon Creek Drainage in Small Tributaries to the Yellowstone River below Fa 11 on, Montana . . . . Summary of the Physical Parameters Measured in Small Tributaries to the Yellowstone River below Fallon, Montana . . . . . Ratios of Median Calcium to Sodium Concentrations and Median Bicarbonate to Sulfate·Concentrations at Various Sites on the Yellowstone River Through Four Seasons of the Year. . . . . and 125. Water Quality Index (WQI) of Samples Collected by the State WQB from Various Streams, Stream Reaches, and Drainage Areas in the Yellowstone Basin . . . 126. 127. 128. 129. 130. 131. 132. 133. Summary of Water Quality in the Yellowstone River Basin of Montana for Surface Water Public Supply and Drinking Water . . . . . . Summary of Water Quality in the Yellowstone River Basin of Montana for Livestock. . .. Summary of Water Quality in the Yellowstone River Basin of Montana for Irrigation . . . Summary of Water Quality in the Yellowstone River Basin of Montana for Aquatic Biota. . Summary of the Potential for Organic Pollution in the Yellowstone River Basin of Montana. . . Summary of Violations of State Water Quality Standards in the Yellowstone River Basin of Montana. . . Summary of Aesthetic Quality in the Yellowstone River Basin of Montana . . . . . . . . . . Summary of Miscellaneous Constituents in the Yellowstone River Basin of Montana. . . . . . . .. xvii 247 249 254 256 258 263 271 274 279 282 287 295 297 299 303 134. 135. 136. 137. Regression Equations Between TDS (in mg/1) and Monthly Discharge (Q} (in Acre-feet) in the Yellowstone River at Bi 11 i ngs, 1951-1958 and 1963-69. . . . , . . . . . . TDS Values in the Yellowstone River at Billings, Assuming a Low Level of Development without the Fish and Game Reservati on . . . . . . . . . . . . . . . . . . . . . . . TDS Values in the Yellowstone River at Billings, Assuming an Intermediate Level of Development without the Fish and Game Reservation .................. . TDS Values in the Yellowstone River near Billings, Assuming a High Level of Development without the Fish and Game Reservation . . . . . . . . . . . . . . . . . . . . . . . 138. ·TDS Values in the Bighorn River, Assuming an Intermediate Level of Development without the Fish and Game Flows ... 139. TDS Values in the Bighorn River at Bighorn, Assuming a High Level of Development without the Fish and Game Flows 140. TDS Values in the Mid-Yellowstone River, Assuming a Low Level of Development with No Reservation of Fish and Game Flows. . . . . . . . . . . . . . . . . . 141. TDS Values in the Mid-Yellowstone River, Assuming an Intermediate Level of Development with No Reservation of Fish and Game Flows ............... . 142. TDS Values in the Mid-Yellowstone River, Assuming a High Level of Development with No Reservation of Fish and Game Flows . . . . . . . . . . . . . . . . . . . . . . . 306 307 308 309 314 315 321 322 323 143 .. Regression Equation between TDS Concentrations and Monthly Discharge (Q) in the Tongue River near Miles City, 1951-1969. 328 144. 145. 146. 147. 148. TDS Values in the Tongue River, Assuming a Low Level of Development with 100 Percent of the Northern Great Plains Resources Program's Fish and Game Flows . . . . . . . .. TDS Values in the Tongue River, Assuming an Intermediate Level of Development with 60 Percent of the Northern Great Plains Resources Program's Fish and Game Flows ..... TDS Values in the Tongue River Assuming a High Level of Development without ·the Fish and Game Flows .. TDS Values in the Tongue River, Assuming a High Level of Development with Fish and Game Flows .......... . Regression Equation between TDS Concentrations and Monthly Discharge (Q} in the Tongue River at the State Border near Decker, 1966-1970 . . . . . . . . . . . . . . . . . . . . . XViii 329 330 331 332 335 149. 150. 151. 152. 153. 154. 155. 156. Regression Equations between TDS and Monthly Discharge (Q) in the Powder River near Locate, 1951-1963 ...... . TDS Values in the Powder River, Assuming a Low Level of Development with 1,150,000 af Storage ...... , . TDS Values in the Powder River at Locate, Assuming a High Level of Development with 1,150,000 af Storage Concentrations of Dissolved Minerals and SAR Value That Would Be Released from a Reservoir Constructed on the Powder River, Based upon Historical Records .. Regression Equations between.TDS and Monthly Discharge in the Yellowstone River near Sidney, 1951-1969 .... TDS Values in the Lower Yellowstone River near Sidney, Assuming a Low Level of Development ........ . TDS Values in the Lower Yellowstone River near Sidney Assuming an Intermediate Level of Development .... TDS Values in the Lower Yellowstone River near Sidney, Assuming a High Level of Development ......... . xix 0 • 0 ~ • 0 344 347 34B 351 354 355 356 357 af af/y A PHil. APO b/d BU~ BOD BOD, c J cfs em COD DHES DNRC DO E EIS EPA F FC FWPCAA gp~ hm hm3/y JTU km KWH ~'BAS m me/1 mg/l mg P/1 mg N/1 mi maf maf I d rrr.~af/y mcfd 111!1 mmt/.y ~~~~~c mw N NGPP.P Nl acre-feet acre-feet per year . American Public Health Association area-1~ide planning organization barrels per clay Bureau of Land Management biochemical oxygen demand five-day biochemi ca 1 oxygen demand Celsius cubic feet per second centimeters chemical oxyqen demand Department of Health and Environmental Sciences Department of Natural Resources and Conservation di sso 1 ved oxygen estimated flow environmental impact statement Environmental Protection Agency Fahrenheit fecal coliforms Federal ~later Poll uti on Control Act Amendments of 1972 gallons per minute cubic hectometers cubic hectometers per year Jackson Turbidity Units kilometers kilowatt hours methylene blue active substance--dye measure of apparent detergents meters milliequivalents per liter milligrams per liter milligrams phosphorus per liter milligrams nitrogen per liter mile million acre-feet million acre-feet per day million acre-feet per year million.cubic feet per day mi 11 imeter million tons per year Montana Pollutant Discharge Elimination System cubic meters per second megawatts nitrogen Northern Great Plains Resources Program no i nforma ti on XX rmc O&G p PHS RC s SAR sc SCF/D ST STORET T TA TDS TH TOC TR TSIN TSS Turb T/d USBR USDA USDI USDHEW US EPA USGS WRCB WQB WQCB WQI \J \Jg/1 \Jmhos/cm < > National Technical Advisory Committee oil and ')rease phosohorus Public Health Service rad i ochemi ca 1 sen.sitive sodium adsorption ratio specific conductance standard cubic feet per day semi-tolerant a national data storaqe & retreival system tolerant · total alkalinity total dissolved solids total hardness total organic carbon total recoverable total soluble inorganic nitrogen total suspended sediment turbidity tons per day United States Bureau of Reclamation United States Department of Agriculture United States Department of the Interior United States Department of Health, Education and Welfare United States Environmental Protection Aqency United States Geological Survey Water Rights Control Board l~a ter Qua 1 ity Bureau Water Quality Control Board water quality index micro micrograms per liter micromhos per centimeter less than greater than xxi THE RIVER The Yellowstone River Basin of southeastern Montana, northern Wyoming, and western North Dakota encompasses approximately 180,000 km2 (71 ,000 square miles), 92,200 (35,600) of them in Montana. Montana's portion of the basin comprises 24 percent of the state's land; where the river crosses the border into North Dakota, it carries about 8.8 million acre-feet of water per year, 21 percent of the state's average annual outflow. The mainstem of the Yellowstone rises in northwestern Wyoming and flows generally northeast to its confluence with the Missouri River just east of the Montana-North Dakota border; the river flows through Montana for about 550 of its 680 miles. The major tributaries, the Boulder, Stillwater, Clarks Fork, Bighorn, Tongue, and Powder rivers, all flow in a northerly direction. The western part of the basin is part of the middle Rocky Mountains physiographic province; the easter'n section is located in the northern Great Plains (Rocky Mountain Association of Geologists 1972). THE COiiFLJCT Historically, agriculture has been r4ontana's most ir.1portant industry. In 1975, over 40 percent of the primary employment in Montana was provided by agriculture (r~ontana Department of Comr1unity Affairs 1976). In 1973, a good year for agriculture, the earnings of labor and proprietors involved in agricultural production in the fourteen counties that approximate the Yellowstone Basin were over $141 million, as opposed to $13 million for mining and $55 million for manufacturing. Cash receipts for Montana '·s agricultural products more than doubled from 1968 to 1973. Since that year, receipts have declined because of unfavorable market conditions; some improvement may be in sight, however. In 1970, over 75 percent of the Yellowstone Basin's land was in agricultural use (State Conservation Needs Committee 1970). Irrigated agriculture is the basin's largest water use, consuming annually about 1.5 million acre-feet (af) of water (Montana DNRC 1977) 0 There is another industry in the Yellowstone Basin which, though it con- sumes 1 ittle water now, may require more in the future, and that is the coal development industry. In 1971, the North Central Power Study (North Central Power Study Coordinating Committee 1971) identified 42 potential power plant sites in the five-state (Montana, North and South Dakota, Uyoming, and Colorado) northern Great Plains region, 21 of them in Montana. These plants, all to be fired by northern Great Plains coal, ~10uld generate 200,000 mega1~atts (mw) of electricity, consume 3.4 mill ion acre-feet per year (mmaf/y) of water, and result in a large population increase. Administrative, economic, legal, 1 and technological considerations have kept most of these conversion facilities, identified in the i·lorth Central Po~1er Studv as necessary for 1930, on the drawing board or in the courtroom. There is now no chance of their being completed by that date or even soon after, which wi 11 de 1 ay and diminish the economic benefits some basin residents had expected as a result of coal development. On the other hand, contracts have been signed for the mining of large amounts of Hontana coal, and applications have been a[Jproved not only for new and expanded coal mines but also for Colstrip Units 3 and 4, twin 700-mw, coal-fired, electric generating plants. In 1975, ov.er 22 mill ion tons of coal were mined in the state, up frorri 14 million in 1974, 11 million in 1973, and 1 million in 1969 .. By 1980, even if no new contracts are entered, Montana's annual coal production will exceed 40 million tons. Coal reserves, estimated at over 50 billion economically strippable tons (t·lontana Energy Arlvisory Council 1976), pose no serious con- straint to the lev~ls of development projected by this study, which range from 186.7 to 462.8, million tons stripped in the basin annually by the year 2000. Strip mining itself involves little use of water. How important the energy industry becomes as a water user in the basin will depend on: 1) how much of the coal mined in Montana is exported, and by what means, and 2) by what process and to what end product the remainder is converted within the state. If conversion follows the patterns projected in this study, the energy industry will use fror~ 48,350 to 326,740 af of 1·1ater annually by the year 2000. A third consumptive use of water, municipal use, is also bound to increase as the basin population increases in response to increased employment opportunities in agriculture and the energy industry. Can the Yellowstone River satisfy all of these demands for her water? Perhaps in the mainstem. But the tributary basins, especially the Sighorn, Tongue, and Powder, have much smaller flows, and it is in those basins that much of the increased agricultural and industrial water demand is expected. Some impacts could occur even in the mainstem. 1-Jhat would happen to water quality after massive depletions? Ho1~ would a chan9e in water quality affect existing and future agricultural,industrial, and municipal users? What would happen to fish, furbearers, and migratory waterf01·1l that are dependent on a certain level of instream flow? Would the river be as attractive a place for recreation after dewatering? One of the first mani fes tat ions of t·1ontana 's grm~i ng concern for water in the Yellowstone Basin and else~1here in the state was the passage of. significant legislation. The Hater Use Act of 1973, which, among other things, mandates the adjudication of all existing water rights and makes possible the reservation of water for future beneficial use, was followed by the l~ater Moratorium Act of 1974, ~1hich delayed action on major applications for Yello1·tstone [lasin water for three years. The moratorium, by any standard a bold action, was prompted by a steadily increasing rush of applications and filings for water (mostly for· industrial use) which, in two tributary basins to the Yello~1stone, exceeded supply. The DNRC's intention during the moratorium was to study the basin's water and related land resources, as well as existing and future need for the basin's water, so that 2 the state would be able to proceed wisely with the allocation of that water. The study which resulted in this series of reports was one of the fruits of that intention. Several other Yello~1stone water studies ~1ere undertaken during the moratorium at the state and federal levels. Early in 1977, the 45th l·iontana Legislature extended the moratorium to allo~1 more time to con- sider reservations of water for future use in the basin. THE STUDY The Yellowstone Impact Study, conducted by the Water Resources Division of the 1-lontana Department of Natural Resources and Conservation and financed by the Old \~est Regional Commission, was designed to evaluate the potential physical, biological, and water use impacts of water withdrav1als and water development on the middle and lower reaches of the Yellowstone River Basin in Montana. The study's plan of operation 1~as to project three possible levels of future agricultural, industrial, and municipal development in the Yellowstone Basin and the streamflow depletions associated with that develop- ment. Impacts on river morphology and water quality were then assessed, and, finally, the impacts of altered streamflow, morphology, and water quality on such factors as migratory birds, furbearers, recreation, and existing water users were analyzed. The study began in the fall of 1974. By its conclusion in December of 1976, the information generated by the study had already been used for a number of moratorium-related projects--the EIS on reservations of water in the Yellowstone Basin, for example (Montana DNRC 1976). The study -resulted in a final report summarizing all aspects of the study and in eleven specialized technical reports: Report No. 1 Report No. 2 Report No. 3 Report No. 4 Report No. 5 Report llo. 6 Report No. 7 Future Developn~nt Projections and Hydrologic Modeling in the Yellowstone River Basin, Montana. The Effect of Altered Streamflow on the Hydrology and Geomorphology of the Yellowstone River 3asin, t·1ontana. The Effect of Altered Streamflow on the Hater Quality of the Yello~1stone River Basin, Montana. The Adequacy of 11ontana 's Regula tory Framework for Water Qua 1 i ty Contra 1 Aquatic Invertebrates of the Yellowstone River Basin, 1·1ontana. The Effect of Altered Streamflow on Furbearing f1ammals of the Yellowstone River Basin, Montana. The Effect of Altered Streamflow on Migratory Birds of the Yellowstone River Basin, 11ontana. 3 Report No. 8 Report ilo. 9 Report No. 1 0 Report No. 11 The Effect of .1\ltered Streamflow on Fish of the Yellowstone and Tongue Rivers, Montana. The Effect of Altered Streamflow on Existing f·1unicipal and Agricultural Users of the Yellowstone River Basin, Montana. The Effect of Altered Streamflow on Water-Based Recreation in the Yellowstone River Basin, Montana. The Economics of Altered Streamflow in the Yellowstone River Basin, t1ontana. ACKNOWLEDGMENTS A special thanks is due to Shari Meats, the editor, who saw this massive project through to completion single-handedly, even at the expense of leisure time (for months) and alteration of her personal plans. To save time, she typed most of this report herself. Other DNRC personnel provided assistance. Barbara Williams and Janet Cawlfield typed parts of the report. Graphics were coordinated and performed by Gary Wolf, with the assistance of June Virag and of D.C. Howard, who also designed and executed the cover. Cindi Koch, with the Billings office of the Montana Department of Health and Environmental Sciences' Water Quality Bureau, typed the first draft of the report. 4 PURPOSE The overall goal of this study was to investigate the impacts of coal de- velopment--existing and potential--on water quality in the Yellowstone River Basin. Specific tasks included: 1) the accumulation and analyses of water quality data for all significant surface waters in the area; 2) the investigation of water quality problems directly associated with mining and energy conversion; 3) an investigation of the effects of stream dewatering on water quality; and 4) recommendations on methods of improving the state's water quality program. Alterations in water quality are expected to occur in streams of the Yellowstone drainage as a result of water withdrawals and development. To assess potential impacts on beneficial uses of these surface waters, the cur- rent baseline water quality status of the affected streams must be determined through analyses of available chemical and biological data. Baseline data provide a reference point for assessing the degree of potential impact. For example, a particular surface water might be judged through such assessments as unsuitable for irrigation but of adequate quality for the maintenance of a warm-water fishery and of excellent quality for the watering of stock. Negative alterations of stream quality, therefore, would not affect its use for irrigation but could affect the stream's fishery and reduce the stream's value as a source of water for stock. Assessments of available data should illustrate such existing use-quality relationships and indicate the greatest potential point of impact. These considerations describe the primary purposes for initiating this phase of the study: the gathering and analyses of water quality data for all significant surface waters in the prescribed areas. Such analyses were com- pleted in part by delineating the critical water quality parameters of a system through the comparisons of its physical, chemical, and biological data with pertinent reference criteria and water quality standards. SCOPE In addition to a thorough inventory of baseline water quality of streams in the study area, present and potential activities in the basin that affect water quality were reviewed. Using mathematical models and computer simula- tions, estimates were made of future changes in water quality resulting from 5 new diversions for irrigation, energy conversion, and municipal use projected in the three levels of development explained in appendix A. The primary water quality parameter modeled was total dissolved solids (TDS), but other para- meters were considered where appropriate. The thirty-year period from 1944 to 1973 was the basis for all analyses. MEASUREMENT To completely describe the water quality in any given aquatic system, analyses of water samples must include a large number of physical and biolog- ical parameters. STORET has the potential to store data from the measurements of over 1,500 physical, chemical, and biological parameters. In addition, the United States Geological Survey (USGS) and the Water Quality Bureau (state WQB) of the Montana Department of Health and Environmental Sciences (Montana DHES), between 1965 and 1975, analyzed between 58 and 131 distinct water quality para- meters in samples from the Yellowstone River above Custer, Montana (USDI 1966- 1974b). Data from such analyses include the direct measurements of the concen- . trations of a variety of single chemical constituents in the samples either in their dissolved (on filtered aliquots) or total (on unfiltered aliquots) forms; calcium, magnesium, bicarbonate, carbonate, and the metals are some of the con- stituents measured, typically in milligrams per liter (mg/1) or micrograms per liter (IJg!l) but occasionally as milliequivalents per liter (me/1). Determin- ations of particular parameters in combination have also been made, including total hardness (calcium plus magnesium), total alkalinity (HCO-+CO-+ OH-), sodium adsorption ratios (Hem 1970), dissolved solids as the sdm of ~rominent constituents, and sums of cations-anions. Some constituents can be measured in a variety of different forms through the various steps of their analyses, such as phosphorus (total-P, total ortho-P, dissolved-P, dissolved ortho-P and organic-P, among others), and some of the parameters afford an indirect measurement of general features of the water. For example, specific conduc- tance indicates salinity of dissolved solids and turbidity; suspended sediment, transparency, and chlorophyll indicate algal biomass. In addition, sample water can be used in various laboratory or field tests to define aspects of its quality apart from the chemical analyses, e.g., in bioassays which can be used to delineate a water's possible toxicity or eutrophic potential. Data for all of these parameters can be used to characterize certain as- pects of a water's quality. In general, however, complete descriptions of the water quality in a lake or stream cannot be made because analyses cannot be directed to the entire spectrum of possible parameters; rather, a small subset of parameters is defined by the objectives of the sampling program or study. In addition, the parametric composition of the subsets can vary among the various sampling programs within any given region. As a result, dis- cussions of water quality must revolve around a small percentage of the total possible parameters; such parameters have data which are consistently avail- able through the time frame and between the streams and locations under con- sideration. Several parameters meet these criteria for this inventory and form the basis of a water quality discussion on the Yellowstone River Basin; these are listed in table 1 as common constituents, critical nutrients, metals, and field parameters. In addition to iron, boron, and arsenic, other metals with 6 TABLE 1. f·1ethods of analysis. Parameter ~1ethod Common Constituents--Cations Sodium Calcium ~!agnes i urn Potassium Hardness Common Constituents--Anions Chloride Sulfate Bicarbonate-Carbonate Fluoride Alkalinity Critical Nutrients Ammonia-Nitroqen Nitrate + Nitrite-Nitrogen Orthophosphate-Phosphorus Tota 1 Phosphorus Most metals Iron Boron Arsenic ~leta 1 s Field Parameters Dissolved oxygen pH Specific conductance Temperature Turbidity Feca 1 co 1 i forms Biochemical oxygen demand Atomic absorptjona EDTA titrationa EDTA titration a Atomic absorpt~on EDTA titration Mercuric nitratebtitrationa Thorin titratiRn Acid titra~ion Complexone a Acid titration Phenylatec a Hydrazine reduEtion, diazotization ,c Single reagent c Persulfate digestion, single reagent Atomic absorptiona b Ferron-orthophenanthroline Carmina a Silver diethyldithiocarbamate Modified Winklerc Potentiometric (meter) . ~·lheatstone bridge (meter)a Calibrated me~cury thermometer Nephelometric d t·1embrane filter, colony coun£sa' Incubation, modified Winkler ,c NOTE: f•1any of these analyses ~1ere completed using a Technicon auto- analyzer. aAPHA et al. 1971. bBrown et al. 1970. ~~1illipore Corporation 1976. U.S. Environmental Protection Agency 1974a. 7 relatively consistent data include manganese, copper, zinc, cadmium, and mer- cury; however, several of the metals were only sporadically analyzed through the various sampling programs in the region. These and other parameters with less consistent data (e.g., pesticides and radiochemical variables) were con- sidered as available for a particular stream or basin. PARAMETER GROUPS Related water quality parameters can be combined into various groups for the general purpose of organizing the water quality discussions. The grouping employed for this inventory was adapted from that used by the U.S. Environ- mental Protection Agency (EPA) in its National Water Quality Inventory (USEPA 1974b); the EPA's system was modified slightly to better conform with the types and amounts of data available on the Yellowstone Basin. As a result, five parameter groups were defined for this inventory: (1) physical factors, (2) oxygen status, (3) eutrophic potential, (4) salinity and common ions, and {5) toxic and harmful substances and health hazards. These groups and their associated parameters are briefly described below; more complete descriptions of these groups and their associated implications as pollutants are available in the EPA's report (USEPA 1974b). There is some similarity between groups; many of the parameters placed into one of the groups could easily fit into one or two of the others in par- ticular situations. Some of the parameters in these groups definitely cause pollution and detract from the quality of water for man's activities; consid- erations of such pollutants formed the crux of the EPA's national inventory. However, some of the water quality parameters are not so obviously pollution- causing because they arise from natural features or nonpoint sources. Never- theless, they still detract from water quality and its beneficial use. Both types of parameters are considered in this inventory. Following are descrip- tions of the five parameter groups. Physical Factors Flow, which describes the size of a stream and provides part of the data necessary for calculating loads, can be classified as a physical factor. Load data for a parameter provides the requisite information for judging the poten- tial effect of a tributary stream or point discharge upon the receiving waters. Temperature is another physical factor. Changes in temperature primarily detract from the biotic aspects of an aquatic system by altering its biological composition and the rates of biological activity. Transparency is another physical factor that can, upon alteration, affect biological systems (e.g., by reducing light penetration). Transparency is generally measured indirectly through turbidity. High levels of turbidity imply low transparencies and aesthetic degradation of a stream or lake. Suspended sediment and suspended solids are physical factors that can be determined directly or, through the measurement of turbidity, indirectly. High levels of suspended materials can also directly affect biotic systems and can 8 restrict other uses of the water, such as recreation and public surface supply. High levels of suspended sediment in a stream are typically derived from natur- al or nonpoint sources. Color is another physical factor, but inadequate data are available for consideration of this parameter. Only a few measurements of water color have been made in the Yellowstone Basin. Oxygen Status Adequate levels of dissolved oxygen (00) are critical in aquatic systems for the maintenance of most aquatic life. Low levels of 00 (less than that expected on the basis of a system's temperature and pressure profile--less than 100 percent saturation) often indicate organic pollution and oxidation of organic materials. Organic pollution can arise from a variety of point and nonpoint sources (including runoff from agricultural areas, municipal and industrial point-source discharges, storm sewers, sanitary sewer over- flows, and unsewered discharges) and from natural sources, e.g., inputs of soil organic matter (humus), animal droppings, and vegetative debris such as leaves. 00 expressed as percentage of saturation is an inverse measure of organic pollution; i.e., lower values suggest greater levels of organic input into the water tested. Other parameters, such as five-day biochemical oxygen demand (BOOs), are more valuable in directly quantifying the magnitude of this type of problem. Considerable BODs and DO data are available from streams in the Yellowstone Basin. Data for two other common indices of organic pollution-- chemical oxygen demand (COD) and total organic carbon (TOC)--are relatively sparse and sporadic in this drainage. Eutrophic Potential Eutrophication is the process of nutrient enrichment in a body of water, typically accompanied by increases in plant growth and production which can lead to nuisance algal blooms and macrophyte growths with associated odor and taste problems, oxygen reductions upon decay, and aesthetic degradation. Eutrophi- cation occurs naturally with the normal aging (in geologic time) of streams and lakes, but this process can be and has been greatly accelerated by inputs from point and nonpoint sources of pollution in recent historic time. Numerous chemical elements are required by aquatic plants in varying de- grees for their optimum growth and development; such constituents in the water are classified as nutrients. This includes the macronutrients, a group of elements required by plants in relatively large amounts (Ca, Mg, S, C, P, and N, among others). Plants also require, in extremely small amounts, a group of elements called the micronutrients (Zn, Cu, B, Co, Mn, Mo, and Fe), but all of these parameters, occurring below critical concentrations, can be equally limiting to plant growth. Attention is generally directed to nitrogen (N) or phosphorus (P) as the most likely limiting factor(s) in aquatic systems. High concentrations of these constituents imply a high eutrophic potential in a lake or stream, and additional inputs of Nand P, when limiting, have been found to greatly increase plant production. For this inventory, N and Pare assumed to be the critical limiting nutrients in the Yellowstone River Basin. There are several forms of phosphorus in water; this is also true of nitrogen. However, N and P data in the Yellowstone drainage are available primarily as ( N0 2 + N0 3) -N or rw 3 - N and as ortho-P. Some ana 1 yses have also been completed for ammonia-nitrogen and total-P, but available data are incomplete for the bulk of the.N and P species, including total-N, Kjeldahl-N, organic-N, and organic-P. As a result, N0 2 + N03 (or N0 3 , and NH3 as avail- able) and ortho-P (and/or total-P) are considered to be the prime indices of eutrophic potentia 1 in this inventory. Ortho-P, N03, N02, and NH3 are the forms usually absorbed by plants and therefore most directly involved in the stimula- tion of plant growth. Salinity and Common Ions This grouping consists of a large number of water quality parameters. In many instances, salinity (total dissolved solids) is considered to be the main factor in assessing or describing a water quality. However, many of the common ions that comprise the TDS concentration of a water can individually detract from a water use when in extremely high concentrations. The common consti- tuents listed for this parameter group include primarily the anions and cations described in table 1 and silica. The salinity of a water can be measured or estimated in several ways--in- directly, via the specific conductance of a sample or as the sum of individual constituents (predominantly the common ions) after chemical analyses, or di- rectly, by weighing the filterable residue of an aliquot of water sample after evaporation at 180°C. High levels of salinity and of certain common ions in a pond, lake, or stream are commonly derived from natural sources, but this problem can be intensified by inputs of TDS from nonpoint sources (e.g., from saline seep areas aggravated by poor agricultural practices or from irrigation return flows) and, in some cases, by unique point-source discharges .. Other parameters placed in this group are hardness and alkalinity, which can a 1 so detra·ct from water use and its qua 1 ity, a 1 though adequate 1 eve 1 s of alkalinity are important in acting as a buffer to acid inputs to a stream. The sodium adsoption ratio (SAR) is also included in this group because it is a summary variable describing the Na: Ca-Mg relationships of a water relative to irrigational use. In addition, pH is considered to belong to this group. Excluding silica, considerable amounts of data are available for most of these parameters. Toxic and Harmful Substances and Health Hazards Numerous constituents potentia 11 y present in the water can act as toxic, harmful substances (affecting the biota) or as health hazards (affecting man). This includes some of the parameters described previously in other groupings, although a set of parameters not yet discussed is generally placed into this category--the metals, pesticides and herbicides, radiochemical parameters, phenols, oil and grease, the coliforms (total, fecal, and strep), and the polychlorinated biphenyls. Most of these constituents are pollution-causing, many are abiotic, and most do not usually arise in high concentrations from natural sources. 10 I Only sparse data are available for most of these parameters. As a re- sult, this inventory was directed primarily to certain of the metals and to the fecal coliforms. This latter feature is an indirect indicator of a po- tential health hazard when measured at high levels in a sample. The other parameters that fit into this group are briefly considered for those streams on which such data are available. Even for some of the metals, only sporadic analyses were made. WATER QUALITY INDEX Because the water quality information available for a region under con- sideration was collected by a variety of agencies and is often variable in time, location, and scope, comparison and interpretation of this information is often difficult. The National Sanitation Fuundation has attempted to de- velop a water quality index (WQI) which would: "(1) Make available a tool for dependably treating water quality data and presenting them as a single numeri- cal index, and (2) promote utilization of a process for effectively communica- ting water quality conditions to all concerned" (McClelland 1974). The WQI has been defined as a "single numerical expression which reflects the composite influence of nine significant physical, chemical, and micro- biological parameters of water quality" (McClelland 1974). Nine variables are included in the WQI: DO as percentage of saturation, fecal coliform density, pH, BOD 5 , nitrates (N0 3-N), phosphates {P04-P), temperature departure from equilibrium, turbidity, and total solids. These parameters basically reflect polluted conditions when they deviate from a qualitative, prescribed norm. The WQI is derived from a multiplicative model in which the nine parameters are weighted (as ordered above) 1vith respect to their overall importance to water.quality. The resulting WQI ranges from zero to 100 with the higher val- ues indicative of a better water quality relative to these variables. A value of 100 for a sample would reflect a case where none of the parameters had de- viated from the norm. One disadvantage of this vJQI lies in the necessity of knowing all nine values and in the possibility of missing data. According to Inhaber (1975), "Almost no environmental information is now (or has been) collected with an .index in mind, and so the data tend to be highly non-uniform and difficult to amalgamate." As a result, certain of the nine parameters may be missing from the analysis, in which case the WQI would be incalculable. In addition, the WQI, developed in part by McClelland (1974), may not represent the best index for regions with particular problems; a different weighting, ex.clusion of some of the nine parameters, or the inclusion of other variables could afford a more appropriate WQI for some areas. In any event, WQI's have been calculated for those streams in the Yellowstone drainage sampled by the state WQB for all of the critical parameters. Determinations of these nine variables have been stressed in the analysis of recent samples obtained by the state WQB. More complete considerations of the rationale, procedures, calculations, historical background, and applications of the WQI are available from Brown et al. (1970), Brmvn et al. (1973), McClelland (1974), and Brown and McClelland (1974). 11 DESCRIPTION OF STUDY AREA Three segments of the Yellowstone River can be delineated in Montana, de- fined on the basis of the type of drainage associated with each. The upper, southwestern reach comprising about 168 miles (270 km) above Laurel, Montana, has tributaries that drain primarily mountainous areas; several of these streams are relatively large, and many of the streams in this drainage seg- ment have continuous, natural flows. Most of the smaller tributaries also have mountainous origins. In contrast, although the larger streams in the 253-mile (407-km) middle segment (Laurel to Terry, Montana) also have their headwaters in mountainous areas, they also have an extensive prairie drainage. The larger streams in the middle segment typically have a continuous flow, but many of the smaller tributaries are ephemeral or intermittent in nature and have a plains rather than a mountainous origin. Poorer qualities of water are typically associated with streams that have extensive prairie watersheds than those with mountain- ous drainage systems. Low volumes of tributary flow characterize the 129-mile (208-km) segment of the river between Terry and Fairview, Montana. Tributaries are typically small and often intermittent streams of prairie origin. This lower, north- eastern segment, along with the upper and middle· segments and associated drain- ages, roughly correspond to the three water quality management planning areas defined by the state WQB for the Yellowstone River drainage. The water quality in these three segments of the mainstem and the changes in quality through the reaches are in part a reflection of the types and magnitudes of surface water contributions to the mainstem from the drainages associated with the segments. DRAINAGE BASINS EXAMINED AND ASSOCIATED STREAMS The study area has been divided into a primary and secondary area, each of which is subdivided into several subregions (figure 1). Subregions are natural hydrological basins and generally correspond to combinations of two or three minor drainage basins delineated by the Montana Department of Natural Resources and Conservation (Montana Hater Resources Board, no date). The secondary, less extensive survey area extends from the Yellowstone National Park border to the mouth of the Clarks Fork Yellowstone River and consists of b1o minor drainage basins (43B and 43QJ). The associated drainage basins of the major tributaries to the mainstem in this upper segment-- the Shields (.43A), Boulder (43BJ), Stillwater (.43C), and Clarks Fork (43D) rivers, and Sweetgrass Creek (43BV) drainages--were not considered in this inven- tory; tabular summaries and discussions of the chemistry and quality of water in these minor basins are available in a water quality management planning report prepared by Karp et al. (1976). Water quality information for the sec- ondary study area of this inventory is available from several sequential sam- pling locations along the river. One of the sites, at Corwin Springs, about 6.5 miles (10.5 km) below Gardiner, is the most westerly location, while the one at Laurel, Montana, is located near the eastern border of this secondary area. 12 YEllowsTONE RIVER BASIN PRIMARY ANd SEcoNdARY STudy AREAs ANd AssociATEd SubREGIONs 40 60 80 100 Miles I I I I 0 10 20 40 60 80 100 Kilomelers ~~t=i-.. .t===il----lt==:jl ! MUSSELSHELL WHEATLAND GOLDEN\ I VALLEY 43 YELLOWSTONE NATIONAL PARK \ I • ( N \ ' l I \-- ' ) YELLOWSTONE RIVER BASIN GARFIELD WYOMING McCONE 42 c I r ----, I 42 M --l, I I l GLENDIVE) J J , I I _ _. A -----;-WI 8 I ----- ICil ,g li I~ -~~~ I ~ I Six major subregions were defined ·for the primary inventory portion of the Yellowstone drainage; these subregions were further subdivided. Three of the subregions in the primary study area had segments of the Yellowstone main- stem as the major stream whereas the other three subregions consisted of the drainage area associated with a major tributary to the Yellowstone: 1) Yellowstone mainstem between the mouths of the Clarks Fork Yellowstone and Bighorn rivers; 2) Yellowstone mainstem between the mouths of the Bighorn and Powder rivers; 3) Yellowstone mainstem from the mouth of the Powder River to the state line; 4) Bighorn River; 5) Tongue River; and 6) Powder River. Mainstem Subregions The most western subregion of the primary inventory area that includes a segment of the mainstem consists of the Yellowstone River and tributaries be- tween the confluences of the Clarks Fork Yellowstone (at Laurel) and Bighorn rivers (at Bighorn) (basin 43Q). The major tributary of the Yellowstone in this segment is Pryor Creek (43E) which originates in the Pryor Mountains and flows northward to join the mainstem at Huntley, Montana. Relatively complete chemical data (i.e., .various common ions such as Ca and so 4 , critical nutrients such as N03+N02-N and P0 4-P, several metals such as Fe and Zn, cal- culated information such as sodium adsorption ratio and total dissolved solids, and field parameters--e.g., specific conductance, dissolved oxygen coli forms, and temperature) are available for this creek and a few small tributary streams (e.g., Hay Creek) and for several locations on the mainstem through this seg- ment, including Laurel to the west and Custer to the east. In addition, com- plete chemistry data is available for several of the smaller streams in this region--Arrow and Fly creeks east of Huntley and Canyon and Duck creeks west. Of these four and Pryor Creek, only Canyon Creek drains an area north of the Yellowstone River. Partial chemical data (analysis of a few specific para- meters such as suspended sediment, conductivity, and critical nutrients) are available for several mainstem locations and for numerous small creeks west of Huntley (Fivemile, Alkali, and Blue creeks in addition to Canyon and Duck creeks). These more specific water quality data were collected in conjunction with a waste-load allocation investigation of the Yellowstone River in the vicinity of Billings being completed by the state WQB (Karp et al. 1976b, Klarich 1976). The second mainstem subregion extends from the confluence of the Bighorn River to the confluence of the Powder River near Terry, Montana. This middle region consists of two unequal minor basins--42KJ to the west and a small basin to the east (42K), which consists primarily of the Sunday Creek drainage 15 north of the river near Miles City. The drainage areas of the two major tri- butaries that delimit this middle area (the Bighorn and Powder rivers) plus that of the Tongue River located between these two streams were considered separate subregions. As a result, Rosebud Creek is the major tributary with- in this middle subregion (basin 42A). The creek has its headwaters in the Rosebud Mountains in southeastern Montana and flows in a north to north- easterly direction from its origin, joining the Yellowstone River near For- syth, Montana. Rosebud Creek is close to the town of Colstrip, the site of extensive coal-fired, electrical generation development. Considerable water quality data has been gathered for several locations on this stream through sampling programs for environmental impact statement (EIS) purposes (Montana DNRC 1974). This was also the case for two minor Yellowstone tributaries in the drainage--Sarpy and Armells creeks south of the mainstem between Hysham and Forsyth. In addition to Sunday Creek, complete chemical data are avail- able for other mainstem tributaries in this middle subregion (Froze-to-Death, Great, and Little Porcupine creeks north of the river, and Reservation, Sweeney, and Moon creeks south and for several of the Rosebud Creek tributaries (Davis, Lame Deer, and Muddy creeks near Busby and Lame Deer on the Northern Cheyenne Indian Reservation). Many of these are small, and some are intermittent. Data for the mainstem in this subregion are available for several locations, in- cluding Myers (to the west), Miles City, and Terry (near the eastern boundary). Tributaries to the mainstem in the eastern or lower segment of the Yellow- stone River (a relatively expansive minor basin (42M) that extends from the mouth of the Powder River to the Montana-North Dakota border) are typically small with generally low volumes of flow; many of these streams are intermit- tent. Some complete water quality data are available for a few of these small streams including Cabin, Cedar, and Glendive creeks south of the mainstem be- tween Fallon and Glendive and Fox Creek north of the river near Sidney. The Yellowstone River has been sampled at several locations in this lower sub- region, including sites (in downstream order from the southwest to the north- east) at Terry-Fallon, Glendive, Intake, and Sidney, plus a site in North Dakota between Cartwright and Fairview, Montana (Highway 200 bridge). One of the major tributaries to the Yellowstone in this subregion is O'Fallon Creek (basin 42L). Complete chemical data are available for this stream and for two of its tribu- taries--Sandstone and Pennel creeks near Ismay, Montana. Tributary Subregions Three major tributaries join the Yellowstone River in the primary inven- tory area--the Bighorn, Tongue, and Powder rivers. All of these streams enter the mainstem from the south and have their origins in the mountainous regions of Wyoming (the Bighorn and Owl Creek mountains and the Rattlesnake Range). The drainage areas of these large tributaries were considered separate sub- regions due to the large amount of water quality data available for these basins. Complete chemical information is generally available for several well-spaced lo- cations on the main river in each of these subregions and for several locations on its major tributaries. Similar to the sampling sites on the mainstem, the sampling locations on these major streams were dispersed along the length of the I river in Montana. In addition, chemical data are available from at least one i location on many of the smaller creeks in each of these subregions. 16 The three tributary subregions and associated major rivers are the Big- horn-Little Bighorn rivers drainage (43P and 430) located in the southwestern portion of the primary study area, the Powder-Little Powder rivers drainage (42J and 42I) covering the southeastern sector, and, contiguous in the extreme southern segment of Montana to both of these drainages, the intermediately lo- cated Tongue River drainage (42B and 42C). The Clarks Fork-Pryor Creek-Fly Creek drainages 1 i e to the ~1es t of the Bi ghom sys tern, and the 0' Fa 11 on Creek- Little Missouri systems lie to the east of the Powder-Little Powder rivers drainage. The upstream portion of the Bighorn River in Montana is inundated by Yellowtail Reservoir (Bighorn Lake). One set of chemical data is available for several streams (e.g., Black Canyon and Dry Head creeks) that drain par- tially unsurveyed terrain around Yellowtail Reservoir in Montana and Wyoming and then empty into the reservoir. Water quality data also are available for the Bighorn and Little Bighorn rivers and for several of the smaller streams in their drainage, including Pass, Owl, Lodge Grass, and Reno creeks, which are tributaries of the Little Bighorn River, and Soap, Rotten Grass, Beauvais, and Tullock creeks, tributaries of the Bighorn. Additional data are available for a few miscellaneous creeks in this drainage (e.g., Sioux Pass Creek). In addition, some data have been collected for Sage Creek (basin 42N) near Warren, which originates in the Pryor Mountains of Montana but has the bulk of its drainage in Wyoming where it joins the Bighorn River. Many of the streams in the Bighorn-Little Bighorn system are located totally or in part on the Crow Indian Reservation. Major tributaries in the Tongue River and Powder River systems are Hanging Woman, Otter, and Pumpkin creeks in the former, and Mizpah Creek and the Little Powder River in the latter; a considerable amount of complete chemical data are available for these particular streams. In addition, many small, generally intermittent streams have been sampled during the past year in the Decker- Birney-Ash 1 and a rea of the Tongue River drainage by the Burea.u of Land Manage- ment (BLM) under contract to the USGS for an EIS related to the leasing of federal land for coal mining in this region. Examples of such streams include Fourmile, Bull, and Cook creeks near Birney; Threemile, Beaver, and Liscom creeks near Ashland, and Bear Creek at Otter, Montana (USDI 1976). Other small streams in the Tongue River drainage for which some chemical data are avail- able include Young, Squirrel, and Deer creeks near Decker and Little Pumpkin Creek near Volborg. Complete water quality information for the Powder-Little Powder River subregion was collected primarily from these two rivers and from Mizpah Creek. Single sets of data are available for two minor streams in this drainage--Sand Creek near Volborg and Sheep Creek near Locate. The three segments described on page 12 were not defined strictly on the basis of hydrological basins as ~1ere primary and secondary survey areas and their respective subregions. However, the upper segment of the Yellowstone above Laurel generally corresponds to the subregion defined as the mainstem above the confluence of the Clarks Fork River. The next two downstream sub- regions in the primary study area--the mainstem from the Clarks Fork Yellow- stone to the Bighorn and from the Bighorn to the Powder--closely relate to the middle segment of the river (extending from Laurel to Terry). The lower seg- ment of the Yellowstone below Terry closely corresponds to the final downstream subregion from the Powder River confluence to the Montana-North Dakota border. 17 Theoretically, the adjustments should be made to Or and LTDS 1 (figure 2) before initiating the process detailed in table 20 so that increased salt concentrations would be considered in the water diverted for, and returned from, irrigation. Computational problems ~10uld have increased by at least a factor of 30, however, and that consideration, plus time and logistic factors, made that course of action prohibitive. Adjustments to the salt loads were small in most cases, and only a fraction of Or. the total flow, ~1as diverted in a given month. Consequently, any errors introduced by adjusting salt loads after, instead of before, simulating water quality were judged to be minor. 11ethodology for Other Parameters !'lost conservative parameters can be estimates from total dissolved solids through the use of linear regression equations. Therefore, common ions and hardness were related to TDS by simple linear regression equations developed from data published by the USGS (1966-1974). Two to four years of data were used for each station. Generally, excellent results were obtained (regres- sion coefficients greater than 0.9). Consequently, once future TDS concen- trations were calculated by methods described previously, concentrations of individual ions were computed from regression equations. Determination of hardness, also a linear function of TDS, was obtained in the same manner. Sodium, sulfate, chloride, and bicarbonate ions were examined for each basin and, along with hardness, are discussed under "Other Parameters" for each subbasin where changes in concentration are significant. Sodium adsorption ratio is a nonlinear function of the concentrations of sodium, calcium, and magnesium ions. SAR was estimated by t1·1o methods: {1) SAR as a linear function of TDS, and (2) SAR as a function of sodium, calcium, and magnesium ion concentrations, which were obtained from regres- sion equations applied to simulated TDS values. Results of the two meth- ods generally were similar. No attempt was made to simulate nonconservative parameters such as dis- solved oxygen, fecal coliform bacteria, nutrients, and water temperature. Regression equations were obtai ned for avera9e monthly water temperature as a function of average monthly air temperature and monthly discharge for the Yellowstone River near Sidney during July and August. Results, although not always statistically significant, were used as a guide in estimating the effect of decreased streamflows on water temperature. Generally, however, estimates of the effects of the levels of development on nonconservative parameters, including sediment, ~1ere only qualitative and based on the judgement of the authors. 18 Two levels of water quality inventory and survey were conducted for this study. Because the major water use impacts from water withdrawal and develop- ment were expected to occur in the middle and lower portions of the Yellowstone drainage in association with the Fort Union coal formation, an intensive survey was designed for the Yellowstone River system below the mouth of the Clarks Fork Yellowstone River, which corresponds to the middle and lower segments described above. In this case, the inventory was directed not only to the Yellowstone mainstem but also to all significant surface waters in the drainage, including major tributaries such as the Little Bighorn, Bighorn, Tongue, and Powder rivers, the significant streams in their drainages (e.g., Tullock, Otter, and Hanging Woman creeks and the Little Powder River), and small but significant tributaries of the Yellowstone River, e.g., Sarpy, Armells, and Rosebud creeks . . For comparative purposes and to describe the quality of water entering the in- tensive survey region, a second, less intensive level of inventory was planned for the Yellowstone drainage above the Clarks Fork Yellowstone River--the upper segment described previously. In this case, none of the numerous major or minor streams in the drainage (e.g., the Shields, Boulder, Stillwater, and Clarks Fork Yellowstone rivers, and Tom Miner, Bill, Big Timber, Sweetgrass, and Deer creeks) were considered to any great detail; only the water quality status of the upper Yellowstone River mainstem was surveyed. Eighty percent of the additional agricultural development and all of the future energy development is projected to occur in eastern Montana (see appendix A). Consequently, only that portion of the basin east of Billings was analyzed for changes in water quality. To facilitate the analysis, the watershed was di- vided into six subbasins along hydrological boundaries. Each subbasin, and the station used to gage outflow at the subbasin's lower boundary, is listed below: 1) upper Yellowstone--Yellowstone River at Billings; 2) Bighorn--Bighorn River at Bighorn; 3) mid-Yellowstone--Yellowstone River near Miles City; 4) Tongue--Tongue River at Miles City; 5) Powder--Powder River near Locate; and 6) lower Yellowstone--Yellowstone River near Sidney. DATA SOURCES AND CHEMICAL ANALYSES UNITED STATES GEOLOGICAL SURVEY One major source of water quality information used. in this inventory was the USGS. The USGS is primarily a contractual agency that maintains several water quality monitoring stations on various streams throughout the inventory area and the state as funded by interested groups (e.g., the Montana Department of Fish and Game, the Environmental Protection Agency, and the United States Bureau of Reclamation) (USDI 1976). The chemical, physical, and biological data obtained from their sampling programs are summarized by water year in 19 Water Resources Data for Montana, Part 2--Water Quality Records. Because the period since September 1965 was defined as "current" for this inventory, only data obtained since then were used for this review with a few exceptions (USDI 1966-1974b). Water quality information obtained during water year 1975 and the first part of 1976 had not yet been published at the time of this writing. The water quality sampling program of the USGS prior to 1966 was directed to only a few streams and locations in the Yellowstone River Basin of Montana. In addition, neither the amounts (sampling frequency, historic record) nor the parametric spectrum of the chemical data were particularly extensive during this pre-1966 period. A large part of this pre-1966 data was obtained during an extensive suspended sediment-temperature investigation of Bluewater Creek (to collect baseline data for determining the feasibility of placing a fish hatchery on the stream) and from four irrigation network stations--the Yellow- stone River at Billings and Sidney, the Bighorn River at Bighorn, and the Tongue River at Miles City. In the former case, daily temperature and suspended sedi- ment information, but no related chemical data, were collected for several years. However, Bluewater Creek is not considered a part of the secondary area for this inventory since it is a tributary of the Clarks Fork River. Temperature data and some chemical information, primarily for those parameters that more directly influence the irrigative use of water, were obtained from the irrigation network stations. Since about 1968-1969, water quality sampling programs in the Yellowstone Basin have increased in the number of stations, spectrum of parameters, and frequency of collections (table 2). The irrigation network stations, now more comprehensive in the range of data gathered, have been continued. The USGS National Stream Quality Accounting Network and the International Hydrological Decade Station programs have added a few water-quality stations to the region, as has the establishment of hydrologic benchmark stations in the drainages of Montana. The development of radiochemical, pesticide, and suspended sediment stations has also further increased the water quality data base for the region in recent years. As an example of this increased emphasis on water quality sampling since 1968, in water year 1966, only eleven water quality sites, including two on the Yello~1stone River, three on Bluewater Creek (only temperature and sediment data), and two on the Bighorn River where only temperature data were obtained, were sampled in the Yellowstone River Basin of Montana. At the USGS station in Billings, about 18 parameters were directly analyzed, including discharge and chemical analyses (common ions plus N0 3, boron, dissolved solids, specific con- ductance, and pH). In contrast, 10 sites were sampled on the Yellowstone River in· 1974, and 26 within the Yellowstone Basin of Montana during this time. In water year 1971, 54 rather than 18 parameters were analyzed in samples taken at Billings, including a number of pesticides, radiochemical parameters, some metals, and some suspended sediment measurements in addition to the analyses listed previously. Table 3 summarizes the streams and associated locations for which water quality data between October, 1965 and September, 1974 are available from USGS publications (USDI 1966-1974b). Specific parameters analyzed at these sites are considered on pages 83 to 305 in this report. Table 4 presents a list 20 --------------- TABLE 2. Water quality monitoring stations in the Yellowstone River Basin of !•fontana operated by the USGS between September 1965 and September 1974. Years of Recordb Site Designation Locationa Chemical Temperature Sediment North Fork Bluewater Creek near Bridger 06S 24E l5CB l /66-9/70 3/60-9/62 10/63-9/70 Bluewater Creek near Bridger 06S 24E 09AA 5/60-9/66c 4/60-9/70 10/67-9/70 Bluewater Creek at Sanford Ranch, 06S 24E 06CD 10/63-9/70 3/60-9/62 near Bridger 10/63-9/70 Bluewater Creek near Fromberg 05S 23E 27DC 10/63-9/70 3/60-9/62 10/63-9/70 Bluewater Creek at Fromberg 055 23E 21CB 8/61-9/64 4/60-9/70 l/66-9/70 Yellowstone River at Billings OlN 26E 34AA 10/50-9/53 12/50-9/58 7/63-9/74 7/63-9/74 "' Yellowstone River at Huntley 0211 27E 24C 10/50-9/52 ..... 7/72-9/74 Bighorn River near St. Xavier 06S 31E 16AB 10/66-9/74 12/62-9/74 Bighorn River near llardin 015 33E 24DA l/51-9/51 12/62-9/73 7/69-9/73 Bighorn River at Bighorn 05N 34E 33AA ll/45-8/47 4/49-9/51 5/46-9/54 8/48 8/52-11/58 10/55-9/58 3/49-9/74 6/59-9/74 10/59-6/72 Tongue River at Miles City 07N 47E 230 9/48-9/49 4/49-9/74 6/46-9/51 l/51-9/74 Powder River at l·ioorhead 095 48E 08B 2/51-9/53 2/51-9/53 10/55-9/57 10/55-9/57 7/69-7/72 4/74-9/74 Yellowstone River at Sidney 22N 59E 09CAC 9/48-9/74 1/51-9/74 10/71-9/74 alocations given as township-range-section and in quarter sections as available. bYears of record before 1965 are shown for some stations •1here applicable. cUnreliable data. TABLE 3. Water quality monitoring stations in operation between October 1965 and September 1974 with published records maintained by the USGS on the Yellow- stone River and in the Yellowstone River Basin of nontana below this confluence. Site Designation Yellowstone River at Corwin Springs Yellowstone River near Livingston Yellm~stone River at Laurelc d Yellowstone River near Laurel Yellowstone River at Billings Yellowstone River at Huntley Fly Creek at Pompeys Pillar Yello~1stone River at Custer Bighorn River near St. Xavier Beauvais Creek near St. Xavier Bighorn River near Hardin Little Bighorn River below Pass Creek, near Wyola Little Bighorn River near Hardin Bighorn River at Bighorn Yellowstone River at Myers Yello~1stone River at Forsyth Yellm'lstone River near ~1iles City Tongue River at state line, near Decker Tongue River below Hanging Homan Creek, near Birney Tongue .River bel ow Brandenburg Bridge, near Ashland Tongue River at Miles City Yellowstone River near Shirley Powder River below Fence Creek, near 1·1oorhead in Hyoming Powder River at t1oorhead Little Powder River near \~yomi ng- 1·1ontana state 1 ine in Hyoming YellOI'Istone River near Terry Lower Yellowstone Project Main Canal at Intake Lower Yellowstone Project Main Canal Drain near Cartwright, N.D. Sears Creek near Crain Yellowstone River near Sidney Location a 08S OSE 30BD 03S 09E 12BBA 02S 24E 15CCC 02S 25E 04A OlN 26E 34AA 02N 27E 24C 03N 30E 23DB 05N 33E 35AD 06S 31E 16AB 04S 30E 15 01 S 33E 24DA 07S 35E 35C OlS 34E 19AA 0511 34E 33AA 06N 35E 21DCC 06N 40E 22AAD 08N 47E 31CD 09S 40E 33AB 06S 42E OlDDC OlN 45E 06BCA 07N 47E 23D 1 ON 49E 32 58N 75W 31CBC 09S 48E OSB 58N 71W 36BA 12N 51E lOCO 18N 56E 25CDC 151N 104H 21N 58E 27CBC 22N 59E 09CAC Period of Record between 9/65 and 9/74 7 /69-12/lt 10/69-9/74 2/74-9/74~ 7/69-6/72 1 0/65-9/74c 7 /72-9/74c 1 0/68-9/74~ 7/69-6/70 1 0/65-9/74e 9/67-10/74c 10/65-9/73b,e,f 1 0/69-9/74C 10/69-9/74c 10/65-9/74c 4/74-9/74c 4/74-9/74c 1 0/68-9/74~ 10/65-9/74 4/74-9/74c 4/74-9/74c 1 0/65-9/74c 5/70-9/70b ,e 6/74-10/74b,e 7/69-7/72, 4/74-9/74c 1 0/69-5/lOb 4/74-9/74c 10/70-9/71 b ,e 10/70-9/71 b ,e 10/70-9/7lb,e 1 0/65-9/74c ~Given in township-range-section and in quarter sections as available. ~~~~~~o~h~i~~~~~~~~~~-of the Clarks Fork Yellowstone River. Below the confluence of the Clarks Fork Yello~1stone River. ~Temperature records only are available for some years at these sites. Continued as a continuous thermograph station in water year 1974. 22 i ' TABLE 4. Water quality monitoring stations maintained by the USGS in the study area for which information is being or has been obtained on several parameters. Site Designation Yell01~stone River at Corwin Springs Yello~tstone River near Livingston Yellowstone River near Laurel Yellowstone River at Billings Fly Creek at Pompeys Pillar Yello~tstone River at Custer Bighorn River near St. Xavier Beauvais Creek near St. Xavier Bighorn River near Hardin Little Bighorn River below Pass Creek, near ~/yo 1 a Little Bighorn River near Hardin Bighorn River at Bighorn Sarpy Creek near Hysham Armells Creek near Forsyth Rosebud Creek at mouth, near Rosebud Yell01~stone River near ~1iles City Tongue River at state line, near Decker Otter Creek at Ashland ' Tongue River below Brandenburg Bridge, near Ashland Pumpkin Creek near t•liles City Tongue River at t·liles City Powder River at Moorhead Po~1der River at Broadus Mizpah Creek near Mizpah Powder River near Locate Yellowstone River near Sidney Temp b,c b,c b,c b,c c c b,c b,c b,c b,c b b,c b b b b,c sc b,c b,c b,c b,c c b,c b,c b,c b,c b b,c b b,c Parameters a TSS Pest d b,c c b,c c,d d e b,e d b b b b,c c c c c c c c d b,c RC b,c c b b b b b b b b SG b b b b b b b b NOTE: Temperature-only stations are not included on this list. alnformation is being or has been obtained for the following parameters: temperature (Temp), daily specific conductance (SC), daily total suspended sedi- ment (TSS), pesticide (Pest) levels, radiochemical (RC) analyses, and spectro- graphic (SG) analyses. bData obtained during 1976. cData available for some periods during 10/65-9/74. dRecent periphyton-phytoplankton sampling station. eRecent continuous turbidity, dissolved oxygen, and pH monitoring site. 23 of sites for which once-daily or continuous temperature, specific conductance, or suspended sediment data are available and where pesticide, radioche~ical, or spectrographic data are being or have been collected by the USGS. Biological sampling programs have also increased in recent years; table 4 shows bacteriol- ogical analyses at many locations in the basin and phytoplankton-periphyton assessments at sites on the Yellowstone and Tongue rivers. Algae collections are being made on the Yellowstone River at 1-lyers and near Terry and on the Tongue River below Hanging \·Joman Creek near Birney. The trend towards greater data accumulation has accelerated during the past two years because of concern about the potential dewatering and polluting impacts of irrigation and coal development. Several additional 1·1ater quality stations have been recently put into operation by the USGS. The sampling of a number of small creeks in the Decker-Birney-Ashland area is being funded by the BLM. In addition, the EPA and the USGS are funding the operation of several stations in the lower two-thirds of the Yellowstone River Basin. Table 5 lists additional water quality monitoring sites maintained by the USGS in 1976 but for which no published records are yet available (USDI 1976). In addition to water quality monitoring stations, the USGS operates numer- ous flow gaging stations in the Yellowstone River Basin (USDI l966-1974a, USDI 1976). Many of these are coincident with the ~1ater quality sampling sites, and many are located independently of water quality sites. Some of the water quality sites do not have a corresponding continuous flow measuring capability; instantaneous or estimated flows can be obtained at these locations. A number of the gaging stations are located on the mainstem and major tributaries, and several sites are also located on the smaller and minor streams in the region (e.g., Tullock Creek near Bighorn, Sarpy Creek near Hysham, and Sunday Creek near Mi 1 es City). Methods of chemical analysis utilized by the USGS are generally referenced in their Water Quality Records publications (USDI l966-1974b). Examples would include the following: Rainwater and Thatcher (1960}, Guy (1969}, Hem (1970), Brown et al. (1970), Standard Methods for the Examination of Water and l~aste water (1971}, and Slack et al. (1973). MONTANA WATER QUALITY BUREAU Since about 1973, the. Hater Quality Bureau of the Montana Department of Health and Environmental Sciences has undertaken in the Yellowstone Basin several water quality sampling programs designed to obtain comprehensive water quality baseline data for several studies being completed by the Bureau. Some of these efforts have been finished, and final reports, including tabular sum- maries of water quality data collected by the state ~IQB (and the USGS) along with general discussions of the status of water quality in the related drainage basins, are now available. Included among these reports are three water quality inventory and manage- ment plans prepared by the Bureau for three large sections of the Yellowstone Basin in ~lantana--the upper Yellowstone drainage (above Pryor Creek), the middle Yellowstone River drainage (between Pryor Creek and the Tongue River), and the 24 TABLES. Additional USGS water quality monitoring sites in operation during 1976 1-1hich had no published records as of July 1976. Site Designation Sarpy Creek near Hysham East Fork Armells Creek near Colstrip West Fork Armells Creek near Forsyth Armells Creek near Forsyth Rosebud Creek near Colstrip Greenleaf Creek near Colstrip Rosebud Creek above Pony Creek near Colstrip Rosebud Creek near Rosebud Rosebud Creek at mouth, near Rosebud Squirrel Creek near Decker ·Deer Creek near Decker Tongue River at Tongue River Dam near Decker Fourmile Creek near Birney Bull Creek near Birney Hanging ~Joman Creek near Birney Cook Creek near Birney Bear Creek at Otter Threemile Creek near Ashland Otter Creek at Ashland Beaver Creek near Ashland Liscom Creek near Ashland Foster Creek near Volborg Pumpkin Creek near Sonnette Pumpkin Creek near Loesch Little Pumpkin Creek near Volborg Pumpkin Creek near Volborg Pumpkin Creek near Miles City Powder River at Broadus Mizpah Creek at Olive r~izpah Creek near Volborg Mizpah Creek near Hi zpahb Powder River near Locate Burns Creek near Savage Locationa 06N 37E 30DD 03N 41E 28CCD 04N 40E 21BCC 06N 39E 26ABD OlS 42E 08ACD OlN 43E 29BBB 02tl 43E 2QDDA 04N 42E 12CAC 06N 42E 21ABC 09S 39E 14BB 09S 41E lOCCB 08S 40E 13A 07S 41E 2BABA 06S 42E 28BCA 06S 43E 19DB OSS 42E 2SBAC 07S 4SE 02 04S 4SE 03DDB 035 44E llDAA OlN 44E 34ADB D2N 4SE 27BBD 03N 46E 12BDA 03S 48E 29DDA OlS 49E 31B OlS 49E 06 OlN 49E OS 06N 48E 35CBD ass SlE 03 03S 50E 26C 02N 51E 09C 06N 51E 24CAB 08!1 51 E 14CB 19N 57E 27DDA aLocations given in township-range-section and in quarter sections as available. bsome historical water quality data are available on this stream. 25 lower Yellowstone region (below the Tongue River). These plans were prepared under the direction of the EPA (Karp and Botz 1975a, Karp et al. 1975b, Karp et al. 1976a). In addition, data were collected by the state WQB in a large section of the Yellowstone Basin (from parts of the middle and lm~er drainages) in conjunction with the state's EIS concernin~ electrical generation develop- ments at Co 1 strip, Montana (l1ontana D~RC 1974). The state l~QB has a 1 so re- cently prepared a report dealing with the salinity-water quality aspects of the saline seep phenomenon in Montana (Kaiser et al. 1975); several of the water samples collected and analyzed for the purposes of this study were obtained froo1 the Yellowstone Basin. Appropriate data from all of these sampling pro- grams were considered in their application to this particular inventory. Some of the investigations recently undertaken by the stat~ WQB in the Yellowstone Basin have not been completed at present; hOIC\'t•, in most instan- ces the field 1\Qrk has been largely terminated with the associated data now available for review. In some cases, preliminary drafts of the study reports have been completed, with final drafts anticipated in the coming year. Some of the sampling programs initiated by the state WQB were designed primarily as data-gathering efforts, with no reports expected. All of the information col- lected from these sampling programs, now on file ~lith the state WQB, has been reviewed for applicability to this inventory. These additional studies can be summarized as follows: 1) As previously noted, a waste load allocation investigation of the Yellowstone River between Laurel and Huntley, l·lontana is near com- pletion. This study ~1as funded by the EPA and both chemical and biological aspects were considered; final drafts of two corresponding reports are available (Karp et al. 1976b, Klarich 1976). 2) A limnological investigation of the Tongue River Reservoir in con- junction with strip mining activity in the area is also near com- pletion; a final report for the EPA should soon be available. 3) An extension of the saline seep sampling program described above was funded by the ~lantana Department of State Lands for the collection of additional biological and chemical data from afflicted areas. 4) The Yellowstone-Tongue Area-wide Planning Organization has funded the chemical analyses of samples collected from the Tongue River in re- lation to the closure of the Tongue ~iver dam for repairs in the fall of 1975. 5) The BLM, in cooperation with the USGS and the Montana Departments of Fish and Game and Natural Resources and Conservation, has funded the chemical analysis of a number of sa1~ples collected at eighteen sequen- tial sites along the Yellowstone River from Corwin Springs to Sidney, ~lantana ("water quality runs"). Several sets of such samples were collected at different times of the year. In addition, numerous supplemental water quality samples were collected from the Yellowstone drainage through the past two years as a part of this study funded by the Old Hest Regional Commission. 26 , Most of the sampling programs initiated by the state WQB are best described as geographically complete rather than historically. The intent of these pro- grams was to supplement the data available from the USGS; as a result, sampling was conducted at numerous sites in a study area but with collections at any par- ticular site relatively few in number. Relative to the USGS data, the main dis- advantage of the state WQB's data is the lack of extensive sample replication at a site through time; the main advantage is that the state WQB's sampling efforts have provid.ed information on a variety of streams and locations for which no · previous data are available. In addition, many of the sampling programs com- pleted by the state WQB on thelarger streams of the basin utilized water quality runs wherein several sequential sites were sampled on a stream within a short period of time. Such runs provide some insight into the downstream changes in a stream's water quality and can provide information on any selected phase of the stream's hydrological cycle at any time of the year. For these reasons, USGS and state WQB data appear to be generally complemen- tary. The state WQB programs provide some data on current water quality status of the smaller streams; the USGS programs provide in-depth water quality infor- mation for a few locations on the major streams. Therefore, the USGS informa- tion lends itself more readily to historical interpretation than the state WQB data. However, the water quality runs of the state WQB are more helpful in judging the longitudinal changes that occur in the water quality of major streams for the particular time of year that the run was made. Table 6 summarizes by basin the streams in the secondary and primary study areas that have been sampled by the state WQB through these programs. The num- ber of locations sampled on each of the streams and the number of samples col- lected by the state WQB are also included in the table. Only those samples that underwent a complete chemical analysis have been tabulated for this sum- mary. Field procedures and methods of chemical analyses of water samples col- lected by the state WQB, summarized in a manual available through the state WQB, were generally in accord with standard techniques (Jankowski and Botz 1974). Chemical analyses of most parameters were completed by the Chemistry Laboratory Bureau of the Laboratory Division, Montana DHES; field parameters were analyzed by state WQB personnel shortly after collection of each sample. Methods of analysis are summarized in table 1. Suspended solids were determined gravimetrically after filtering an appro- priate aliquot of the sample through fiberglass filters and drying. Dissolved solids were calculated as the sum of constituents. Sodium adsorption ratios (SAR) were calculated from sodium, calcium, and magnesium milliequivalency data following an equation in Hem (1970). Metals were determined primarily as "total recoverable" rather than dissolved because most analyses were completed on unfiltered samples preserved with concentrated nitric acid (five milliliters of acid per liter of sample (Jankowski and Botz 1974). Flow measurements were made on many of the smaller streams in association with the collection of grab samples. "Gurley" or pygmy current meters were used to measure the velocity of discharge along with the appropriate depth and width·measurements to assess the areal component of flow (Carter and Davidian 1968, Jankowski and Botz 1974). In some cases, the instantaneous discharge of a creek was estimated, but, when- ever possible, flow measurements were obtained either from a USGS gaging station on the stream or as indicated above. 27 \ TABLE 6. Streams sampled by the state WQB in the secondary and primary inven- tory areas of the Yellowstone River Basin since the summer of 1973. Stream and Basin Yellowstone River above confluence Clarks Fork Yellowstone River Mainstem (secondary area)a,b,j Yellowstone River drainage beb1een Clarks Fork and Bighorn riversc t·1a ins tema ,b ,h ,j Spring Creekd Duck Creek Canyon Cree~ Pryor CreekJ Hay Creek East Fork Pryor Creek East Fork Creek Arrow Creek~ Fly Creek a ,J Bighorn-Little Bighorn rivers drainage Little Bighorn Rivera,j Spring Creek Pass Creek East (Little) Owl Creek Sioux Pass Creek Owl Creek Gray Blanket Creek Lodge Grass Creek Reno Creek a f . Bighorn River ' ,J Sage Creek Crooked Creek Porcupine Creekg Dry Head Creekg Hoodoo Creekg Big Bull Elk Creekg Little Bull Elk Creekg Black Canyqn Creekg Soap CreekJ Rotten Grass Creek Tullock Creek 2fl Locations Sampled 10 4 1 1 1 2 1 1 1 2 1 4 1 1 1 1 2 1 1 1 3 2 1 1 1 1 1 1 1 1 2 2 Number of Samples 42 27 1 1 1 9 2 2 1 5 3 9 1 2 1 1 3 1 4 1 13 2 2 1 1 1 1 1 1 2 5 15 TABLE 6. Continued Locations Number of ' Stream and Basin Sampled Samples r Yellowstone River drainage between Bighorn and Powder rivers Mainstema,b~h,j 6 43 Sarpy CreekJ 2 9 Reservation Creek 1 3 East Fork Armells Creek. 3 9 Hes t Fork Arme 11 s CreekJ 2 3 Arme 11 s CreekJ 2 9 Sheep Creek 1 1 Smith Creek . 1 2 Rosebud CreekJ 6 30 Indian Creek 1 1 Davis Creek 1 2 Muddy Creek 1 1 Lame Deer Creek 1 3 Sweeney Creek 1 2 Moon Creek 1 2 A lf Creek 1 1 Froze-to-Death Creek 1 1 Starve-to-Death Creek 1 2 Great Porcupine Creek 2 3 Little Porcupine Creek 1 3 Sunday Creek 1 9 Tongue River drainage rlainstema' i ,j 10 54 Youngs Creek 1 1 Squirrel Creek 1 1 Deer Creek 1 1 Stroud Creek 1 1 Canyon Creek 1 1 Cow Creek Creekj 1 1 Hanging Woman 2 11 Logging Creek 1 1 Otter CreekJ . 3 11 Pumpkin CreekJ 2 16 Little Pumpkin Creek 1 1 ~ Powder River drainage Mainstema,j Rivera 6 26 Little Powder 1 12 Sheep Creek 1 1 Mizpah Creek 3 12 Sand Creek 1 1 29 TABLE 6. Continued Stream and Basin Yellowstone River drainage below confluence Powder River Mainstema,b,j . 0' Fall on CreekJ . Sandstone CreekJ Pennel Creek Cabin Creek Cedar Creek Sevenmile Creek Glendive Creek Fox Creek Lonetree Creek Second Hay Creek Tota 1 s Locations Sampled 7 3 1 1 2 1 1 1 1 1 1 149 Number of Samples 28 14 2 1 3 2 1 3 3 1 1 512 aSome published water quality records between the years of 1965 and 1975 are available for these streams from the USGS. bseveral of the locations in these reaches were utilized for the Yellowstone water quality runs; two additional sets of samples have been collected from these sites on recent runs but not tabulated because the results of the chemical anal- yses are not yet available. cNumerous samples from the mainstem and certain tributaries have not been tabulated for this region; these were collected for partial chemical analyses as part of the ~1aste load allocation investigation of the YelloHstone River beb1een Laurel and Huntley. dThis creek joins the Clarks Fork River very near the river's mouth. eSeveral other samples were collected from this stream but not tabulated; these were obtained as part of an irrigation study dealing with specific para- meters. Data are also available for irrigation return flows and canals. f\·later quality information is available from the USGS for the Beauvais Creek tributary of the Bighorn River. gThese creeks are Bighorn tributaries in the vicinity of Yellowtail Reser- voir (Bighorn Lake). hsamples tabulated include those obtained from several Yellowstone River backwater areas. ;Samples tabulated include those collected for complete analyses during the closure of the Tongue River Dam for repairs; however, the listing does not in- clude those samples collected for partial analyses as a part of the Tongue River Reservoir strip mining study. jPartial chemical analyses are also available for these streams; these samples were not included in the tabulations. 10 , MISCELLANEOUS SOURCES AND OTHER INVESTIGATIONS Water quality data from various streams in the Yellowstone River Basin are also available from STORET (a national data storage and retrieval system). Although this information was surveyed for this inventory, a major portion of the data stored in this computer system was originally obtained by the USGS and is therefore published in its annual Water Quality Records publications (USDI 1966-1974b). The main value of STORET to this study was in the retriev- al of more recent and currently unpublished water quality data collected by the USGS (from October of 1974 to January of 1976). Unpublished and provisional water quality data collected by the USGS in the last two years was obtained directly from the USGS in conjunction with monitoring activities of the state WQB (e.g., to supplement continued monitor- ing on Armells and Rosebud creeks in the Colstrip area). Data collected by the USGS during the closure of the Tongue River Dam in the fall of 1975 was also reviewed for this inventory. In addition to the programs of the USGS and the state WQB, water-quality- related studies and planning efforts have been or are being completed in the Yellowstone River Basin by other state and federal agencies. These range from broad, general studies covering large geographic areas to specific investiga~ tions typically concerned with particular streams, stream segments, lakes- reservoirs, or with particular water quality problems. The Missouri River Basin Comprehensive Framework Study (Missouri River Basin Inter-Agency Com- mittee 1969), a Bureau of Reclamation resources report (USDI 1972), the inter- agency Northern Great Plains Resources Program (NGPRP 1974), and the Decker- Birney Resource Study of the Bureau of Land Management and the United States Forest Service (USDI and USDA 1974b) all serve as examples of·the more general type of study. The earliest effort was directed at broadly describing water and related resources in the upper Missouri River Basin of which the Yellow- stone drainage is a part. The Bureau of Reclamation study was directed at more specifically delineating the resources in the basins of eastern Montana, in- cluding considerations of the basins' water resources and water quality attri- butes. The Water Quality Subgroup of the NGPRP has attempted to provide al- ternative methods for the development of water resources in the basins of southeastern Montana; water quality aspects were considered in the study as well as the effects of in-stream flow variations on aquatic life (Boree 1975, USEPA 1974). The Decker-Birney Resource Study was initiated in conjunction with the federal leasing of lands for coal and energy development. In addition, the National Commission on Water Quality has become involved in the Yellowstone drainage, and the Missouri River Basin Commission is preparing a Level B study which will attempt to resolve conflicts between industrial and agricultural de- velopment and in-stream flow requirements. The recently established area-wide planning organizations (APOs) funded through the EPA are also directing their efforts to water quality problems in their respective regions (208 planning districts). Two such districts are lo- cated in parts of the Yellowstone drainage--a Mid-Yellowstone APO headquartered in Billings, and the Yellowstone-Tongue APO located in Broadus--with a state- wide 208 covering the remainder of the basin. A research group from Montana State University directed by Dr. J.· C. Wright has recently completed an extensive limnological investigation of 31 Yellowtail Reservoir (Soltero 1971, Soltero et al. 1973, Wright and Soltero 1973). The Cooperative Fishery Research Unit at Montana State is conducting a limnological-fishery study of the Tongue River Reservoir in relation to· strip mining activities in the area (Whalen et al. 1976). Other important studies of a more specific nature in the Yellowstone Basin include the work of the Montana University Joint Water Resources Research Center and the ground and surface water quality monitoring efforts of the Montana Bureau of Mines and Geology in the Colstrip and Decker strip mine areas (Van Voast 1974, Van Voast and Hedges 1976). The study of the Water Resources Research Center involved a chemical and biological analysis of the upper Yellov1stone River as baseline data in response to the possibility of construction of Allenspur Dam on the mainstem above Livingston, Montana. Similar information is also available from Stadnyck (1971). Other examples of specific investigations in the basin include: 1) the strip mine spoils and reclamation research of the Montana Agricultural Experiment Station (Hodder et al. 1972, Hodder et al. 1973); 2) studies of sediment problems originating from the Clarks Fork Yellowstone River drainage (Beartooth Resource Conservation and Development Project et al. 1973); and 3) an interagency land use study of the Pryor Mountains which also considered the problem of siltation in Crooked Creek (USDI and USDA 1973, 1974a). In addition, the EPA is completing a national eutrophication survey which in- cludes the Tongue River and Yellowtail reservoirs (USEPA 1975). More detailed listings and descriptions of the water quality and planning studies in the Yellowstone Basin are available in the three management plans prepared for the region by the state WQB (Karp and Botz 1975, Karp et al. 1975b, Karp et al. 1976). WATER QUALITY REFERENCE CRITERIA RATIONALE Water quality considerations are relative--that is, the suitability of water is dependent upon its intended use. For example, the quality needed for stockwater is different from that necessary for man's consumption and domestic use. Criteria and standards have been developed through the years to serve as reference points for evaluating a body of water and the levels of its various chemical, physical, andbiological constituents in relation to various water uses. These criteria and standards can also serve as reference bases for the general assessment and evaluation of surface waters in a given study region. Literature sources were reviewed for those criteria and standards that would delineate the critical concentrations of parameters in relation to the common uses of water in the Yellowstone River Basin. These criteria serve as the basis for the discussions of this inventory. 32 , ~ ' In addition to these reference criteria, other classification schemes, descriptive in nature and not delineative of critical concentrations relative to some water use, have been developed for certain water quality parameters. These systems are of value in verbally describing and summarizing certain water quality attributes. The Water Quality Index serves as one example. As ·further examples, classification systems have been proposed that describe vari- ous levels of hardness and salinity. These systems are summarized in table 7. TABLE 7. ~ardness and salinity classification. Hardness a Salinityb Range (mg/1 as Caco 3 ) Description 0 to 60 Soft 61 to 120 Moderately hard 121 to 180 ~ard >180 Very hard aDurfor and Beckner 1964. bRobinove et al. 1968. Range (mg/1 as TDS) <50 < 1 ,000 1,000 to 3,000 3,000 to 10,000 10,000 to 35,000 >35,000 Description Non-saline (rain and snow) Non-saline (most fresh- water) Slightly saline (some freshwater) Moderately saline (estuaries) Very saline (oceans and estuaries) Briny {miscellaneous systems) The range of values delineating a "very hard" water was not defined as delimiting particular water uses, nor was the "very saline" category of dis- solved solids. ~owever, waters with such high levels of salinity and hardness are not suitable for certain uses. Although the American Water Works Assoc- iation considers a water with less than 80 mg/1 hardness "ideal" (Bean 1962), no definite limits for hardness in public water supply can be specified be- cause consumer" ... sensitivity is often related to the hardness to which the public has become accustomed, and acceptance may be tempered by economic considerations" (USEPA 1973). In contrast, the United States Public Health Service (1962) recommends that waters containing dissolved solids in excess of 500 mg/1 should not be used for drinking water if other more potable and less mineralized sources are available. MONTANA STREAM AND WATER-USE CLASSIFICATIONS The State of Montana had, by 1960, classified the streams of the state according to their most beneficial uses and has also established water quality criteria for the streams relative to these uses. This classification system designated that streams in the state were to be kept, for the large part, in suitable condition for water supply, fishing and other recreation, agriculture, and for industrial water. supply (Montana D~ES 1973). Compliance with the water- 33 use classifications required the treatment of wastewaters untreated prior to 1960 and the improvement of some of the existing treatment facilities in order to meet the new requirements. The stream classifications and water quality criteria of the state were updated and upgraded after 1965 with the passage of the Federal Water Quality Act; minor revisions were also added in response to the Federal Water Pollution Control Act Amendments of 1972. Classifications and standards currently in effect became official on November 4, 1973 (Montana DHES 1973). All surface waters in the primary and secondary inventory areas of this study have been assigned a B-D classification by the State of Montana. The water-use description for this class of surface water has been summarized as follows (Montana DHES undated): The quality is to be maintain~d suitable for drinking, culinary and food processing purposes after adequate treatment equal to coagulation, sedimentation, filtration, disinfection and any additional treatment necessary to remove naturally present im- purities; bathing, swimming, and recreation; growth and (1) pro- pagation of salmonid fishes (a B-D1 stream), (2) marginal propa- gation of salmonid fishes· (a B-D 2 stream), or (3) propagation of non-salmonid fishes (a B-D3 water) and associated aquatic life, waterfowl and furbearers; and agricultural and industrial water supply. The water-use descriptions of the B-D streams contrast to that applied to E-F waters which have a more limited use: "The quality is to be maintained for agricultural and industrial water uses other than food processing" (Montana DHES undated) . B-D 1 surface waters in the Yellowstone River Basin (self-sustaining trout fisheries) include the Yellowstone drainage above Laurel, the Pryor Creek drainage, and the upper portions of the Little Bighorn-Bighorn and Clarks Fork River drainages. B-D2 waters in the region (marginal trout fisheries) include the Yellowstone River and tributaries between Laurel and Billings, the lower Little Bighorn-Bighorn and Clarks Fork River drainages, the upper Tongue River drainage, and Fox Creek in eastern Montana. The Yellowstone River and certain of its tributaries belo~t Billings (e.g., the Powder River drainage and the lower Tongue River drainage) have been designated non-salmonid, warm-water fisheries and given a B-D 3 classification (Montana DHES undated). MONTANA WATER QUALITY CRITERIA Water quality standards have been established by the State of Montana for the B-D stream classification. For some parameters, such as turbidity, the standard specifies an allowable maximum change in stream concentration rather than a specific upper limit; this type of standard is not amenable to use as a reference criteria. However, definite limits or allowable ranges have been established for other parameters by the state, and these standards can be utilized for this purpose (Montana DHES undated); these are summarized in table 8. In addition, Montana's water quality standards reference the 1962 U.S. P~blic Health Service Drinking Wate~ Standards (or later editions) for recommended limits on a number of water quality parameters including inorganic materials and heavy metals (USDHEW 1962). 34 1 w <1'1 -. ~--~----- TABLE 8. t~ontana water qua 1 i ty criteria. as pCi/L Fecal Coliforms Gross Stream (number per 100 ml) f·1i n imum pHC d Oi 1 Beta Classi-Average 10% a Oissol~ed ~lax imum and Radi urn-Radio- fication Number t·1aximum Oxygen Range Temperature Grease 226 activity B-o 1 200 400 7. 0 mg/1 6.5-8.5 67 F (19.4 C) 10 mg/1 1.0 100 B-Of 200 400 6.5-9.0 67 F (19.4 C) 10 mg/1 1.0 100 10/ -611 7.0 mg/1 6/2-9/30 6.0 mg/1 B-03 200 400 5.0 mg/1 6.5-9.0 80 F (26.7 C) 10 mg/1 1.0 100 YR, B-Ie 82 F (27.8 C) YR, 1-NDf 85 F (29.4 C) SOURCE: f•1ontana OHES undated. aTen percent of the total number of samples obtained in a thirty-day period are not to exceed this value. bOissolved oxygen concentrations are not to be reduced below these limits. cNo.changes of pH are allowed outside of these values. dNo increases of temperature are allowed above these limits when the water's naturally occurring tempera- tures are 0.5 F less than these values. eYR, B-1: Yellowstone River between Billings and the Intake diversion structure near Glendive, Montana. fYR, 1-ND: Yellowstone River from Intake to the Montana-North Dakota border. DRINKING WATER AND SURFACE PUBLIC SUPPLY CRITERIA Several communities located along the Yellowstone River, including Living- ston, Laurel, Billings, and Miles Cfty, use this stream as a source of public supply for drinking water and other purposes. U.S. Public Health Service rec- ommendations for the maximum concentrations of various water quality parameters in drinking water, as referenced in Montana Hater Quality Standards (Montana DHES undated), are summarized in table 8. Standards for fluoride in this re- ference are variable depending upon the "annual average of maximum daily air temperatures" in-a region (USDHEW 1962). Lower concentrations are recommended for the warmer climates. Data to provide some idea of the magnitude of this temperature variable in the study region of this inventory were obtained from Karp et al. (1975b) for several weather stations in eastern Montana; this tem- perature factor was estimated as the annual average of these stations (6.3°C, 43.3DF) plus the addition of four to eight degrees Celsius (seven to fifteen degrees Fahrenheit) to afford an adjustment to the maximum. Fluoride standards relative to this temperature estimation are included in table 9. In addition to the Public Health Service standards for drinking water, other sources were reviewed for criteria applicable to public (USEPA 1973) and surface supply (Montana DHES undated). These criteria are also summarized in table 9. In general, the recommended standards for specific parameters are similar among the three sources. AGRICULTURAL CRITERIA Water use for stock and water use for irrigation are the major agricul- tural uses of itreams, lakes, and ponds in the inventory area. In general, waters that have been judged to be safe for human consumption (relative to the criteria in table 9) can also be used for the watering of stock. Animals can, for the most part, tolerate waters with significantly higher. salinities and higher levels of dissolved constituents than can humans, although their overall productivities may be curtailed to some extent through the utilization of such waters (McKee and Wolf 1974). The more lenient water quality stan- dards typically applied to stock water reflect this greater tolerance of ani- mals to dissolved materials. Criteria for stock water, including standards for specific dissolved constituents and for salinity along with the salinity requirements of several domestic animals, were obtained from the EPA (1973), McKee and Wolf (1974), and Seghetti (1951), and are summarized in tables 10-14. Threshold levels denote the concentration of a particular constituent where its physiological effects are first observed in an animal. In contrast to the specific-reference criteria available for animals (in- cluding man), criteria for irrigation water are, of necessity, more arbitrary and flexible due to the variables involved: type of soil, climate, type of crop, and management practices. As a result, specific analyses of particular systems can become complex, and absolute limits and general criteria cannot be rigid (McKee and Wolf 1974). Waters for irrigation are typically divided into broad classes such as "excellent," "good," "injurious," and "unsatisfactory," with a set of appli- cable chemical criteria associated with each water class. Groups of plants are classified as tolerant, semi-or moderately tolerant, or sensitive in relation to each water class in accordance with the plants' ability to tolerate its chemical characteristics. McKee and Wolf (1974) conducted an extensive 36 I I ~ TABLE 9. Selected water quality criteria and standards for drinking water and public surface supply PHS NTAC EPA Standarda Rejectionb Permissible Desirable Constituent Criteria Criteria Reco11111endation Ammon ia-N ----0.5 <.01 0.5 ArsenicC 0.01 0.05 0.05 absent 0. 1 Bariumc --1.0 1.0 absent 1.0 Boronc ----1.0 absent -- Cadmiumc --0.01 0.01 absent 0.01 Chloridec 250 --250 <25 250 Chromium (Cr+6)c --0.05 0.05 absent 0.05 Copperc 1.0 --1.0 near zero 1.0 Total dissolved solidsc 500 --500 <200 -- Fecal coliforms (f) (f) 2000 <20 2000 Iron 0.3 --0.3 near zero 0.3 Leadc --0.05 0.05 absent 0.05 flanganeseC 0.05 --0.05 absent 0.05 flercuryc --------0.0002 Nitratec,d 45 --------Ni tra te-Nc ,d 10.2 ------10 NOtN0 2-f·lc • d ----10.0 near zero --Ni rite-Nc,d --------1.0 Oxygen (dissolved) ---->3 saturated -- pH ----6.0-8.5 --5.0-9.0 Phenols c 0.001 --0.001 absent 0. 001 Selenium --0.01 0.01 absent 0. 01 S il verc --0.05 0.05 absent -- SulfateC 250 --250 <50 250 Turbidity (JTU) 5 --75 near zero --Zincc 5.0 --5.0 near zero 5.0 Radioactivity· as pCi /l : Gross betaC (1' 1000 <100 --Radium-226c 3 < 1 --Fluoride:c,e Upper 1 imi t 1.5-1.7 2.2-2.4 2.2-2.4 Optimum 1.1-1.2 --(same) -- Control limits 0.8-1.7 ---- SOURCES: U.S. Public Health Service (PHS) 1962, National Technical Advisory Comnittee (IITAC) 1968, and the U.S. Environmental Protection Agency (EPA) 1972. NOTE: Concentrations given in mg/1 unless otherwise specified; fecal coliforms given as the number per 100 ml. aThese chemical substances should not be present in water supplies in excess of the listed concentrations where other suitable supplies are or can be made available. bThe presence of these substances in excess of the listed concentrations consti- tutes grounds for rejection of the supply. cTreatment--deffned as coagulation, sedimentation, rapid sand filtration, and chlorination--has little effect on these constituents. dAdverse physiological effects on infants may occur in extremely high concen- trations. eCriteria varies with the annual average of maximum daily air temperatures; with fluoridation, average fluoride levels should be kept within the control limits. fc ·t · n er1a technique. varies with the volume of sample, sampling frequency, and analytical 37 I TABLE 10. Water quality criteria for stock as set forth by the California Water Quality Control Board. Threshold Level Limiting Level pH 6.0 and 8.5 5.6 and 9.0 TDS 2500 5000 HC03 500 500 Ca 500 1000 CI 1500 3000 F 1.0 6.0 ~1g 250 500 Na 1000 2000 so 4 500 1000 As 1.0 SOURCE: California Water Quality Control Board 1963. NOTE: Concentrations expressed in mg/1. TABLE 11. Water quality criteria recommended by the EPA for stock. Chemical Constituents Al As B Cd Cr Co Cu F Pb Hg N02+N03-N rw 2-N Se v Recommended Concentrations (in mg/1) 5 0.2 5.0 0.05 1.0 1.0 0.5 2.0 0. 1 0.01 100 10 0.05 o. 1 SOURCE: U.S. Environmental Protection Agency 1973. 38 I ~ TABLE 12. Threshold salinity (TDS) levels for fann animals. Animal Salinity Level Poultry Pigs Horses Dairy cattle Beef cattle Adult dry sheep SOURCE: l~cKee and flolf 1974. 2,860 4,290 6,435 7,150 10,000 12,900 NOTE: Concentrations expressed in mg/1. TABLE 13. Use and effect of saline waters on livestock and poultry. Use and Effect Excellent for all stock Very satisfactory for livestock and poultry; temporary effects, if any Satisfactory for livestock; poor for poultry Permissible for livestock; unacceptable for poultry and lactating animals Somewhat risky with older livestock and poor for swine; unacceptable for young and lactating animals and for poultry Generally unsuitable for most animals SOURCE: U.S. Environmental Protection Agency 1973. NOTE: Concentrations expressed in mg/1. Salinity Level <1,000 1,000-3,000 3,000-5,000 5,000-7,000 7,000-10,000 >10,000 TABLE 14. Montana salinity classification of waters. Water Class Good Fair Poor Unfit SOURCE: Seghetti 1951. Salinity Range <2500 2500-3500 3500-4500 >4500 NOTE: Measurements expressed in mg/1. 39 survey of the literature and developed the classification scheme for irrigation waters presented in tables 15 and 16. Also included in this table are recom- mendations for the maximum concentrations of trace elements that should be present in irrigation waters used continuously on all soils (USEPA 1973). The chemical criteria in this table can be used to judge the quality of Yellowstone River Basin water for irrigative use. Classification of the boron and salinity tolerances of Yellowstone Basin crops, garden plants, and forage are presented in table 17 (Allison 1964, Hem 1970). Agricultural Handbook No. 60 (USDA 1954) lists four broad ranges or classes of salinity in relation to a water's use for irrigation--a low salinity hazard with specific conductances (SC) less than 250 ~mhos/em at 25oc, a medium salinity hazard (SC = 250 to 750 ~mhos), a high salinity hazard (SC = 750 to 2250 ~mhos), and a very high salinity hazard (SC > 2250). These classes, in combination with four sodium hazard ranges based on the sodium adsorption ratios of a water (Hem 1970) provide sixteen classes of water with varying levels of value for irrigation use (Richards 1954). The Cl-Sl class of water is probably suitable for the watering of most plants under most conditions, whereas the C4-S4 class is probably unsuitable for irrigation except in a few unique cases. BIOLOGICAL CRITERIA Water quality criteria in this case deal with two aspects of the biology of aquatic systems: (1) critical nutrient levels that indicate eutrophic con- ditions, and (2) the concentrations of particular parameters that might prove to be toxic or harmful to aquatic life. As with irrigation waters, such cri- teria are difficult to establish in a definitive sense due to the variability among biological systems and among individual organisms. However, general levels can be established for some parameters that at least serve as first- order approximations of critical concentrations, and these can be used as reference criteria in water quality inventories. Nitrogen and Phosphorus Lund (1965), in his extensive literature review, concluded that ''nitrogen and phosphorus can still be considered as two of the major elements limiting primary production." Gerloff and Skoog (1957) suggested that nitrogen appears to be the more critical factor in the limitation of algal production in natural waters because phosphorus is often stored in excess in algal cells beyond ac- tual need (luxury uptake). But phosphorus concentrations can be very low in some waters, and this parameter may be the more limiting parameter in these particular cases (Lund 1965). Specific criteria describing the critical levels of nitrogen and phosphorus limiting to aquatic systems and necessary to pro- mote nuisance algae blooms have not been firmly established due to the complex- ity of the relationships between these two constituents and between these two constituents and the remaining chemical and physical-biological components of an ecosystem (USEPA 1973). As a result, such criteria, as developed through sev- eral investigations, are variable. For example, the EPA (1974b) in its National Water Quality Inventory used 0.1 mg/1 of total-P and 0.3 mg/1 of dissolved phos- phate (0.1 mg/l of P0 4-P) and 0.9 mg/l of nitrite plus nitrate (as N) as re- ference criteria for these constituents. However, based on information from 40 • = TABLE 15. Summary classification of irrigation waters and associated water quality criteria and recommended maximum concentrations of trace elements for all plants in continuously used irrigation waters. Water Speci fie Salinity Class Boron (mg/1) SAR Cl (me/1) so 4 (me/1) Conductance TDS (mg/1) Hazard I <1.0 <1.0-4.2 a <2-5.5 <4-10 <500-lOOOb <700 low-medium I I <2.0 1.0-11.6 2-16 4-20 500-3000 350-2100 medium- very high Ill <3.0 >9.0-11.6 >6-16 >12-20 >2500-3000 >2500-3000 very high SOURCE: McKee and Wolf (1974). NOTE: The water classes are defined for two purposes. First, for purposes of overall soil/climate man- agement, they are defined as follows: I Excellent to good; suitable under most conditions. II Good to injurious; harmful under certain conditions of soil, climate, and practices. III Injurious to unsatisfactory; unsuitable under most conditions. Second, water classes as they relate specifically to plants are defined as follows: I Suitable for irrigation of all or most plants, including salinity-and boron-sensitive species. II Not suitable for most salinity-and boron-sensitive plants; suitable for all tolerant and many semi-tolerant species. III Unsatisfactory for most plants except those that have a high tolerance to saline conditions and to high boron levels. aRecent work favors the upper limit. bin ~mhos/em at 25°C. TABLE 16. Recommended maximum concentrations of trace elements for all plants in continuously used irrigation waters. Trace Element Recommendation Al 5.0 Be 0. 1 Cd 0.01 Cr 0. 1 Co 0.05 Cu 0.2 F 1.0 Fe 5.0 Pb 5.0 Li 2.5 Mn 0.2 Mo 0.01 Ni 0.2 Se 0.02 v 0.1 Zn 2.0 SOURCE: u.s. Environmental Protection Agency (1973). NOTE: Recommendations expressed in mg/1. 42 ' I I J / TABLE 17. Relative tolerances of various crops and forage to salinity and boron. Salinity Boron a Tolerant b Moderately ob semi -tolerant Sensitive b (12 to 6) (8 to 4) (6 to 3)b ( 3 to 1. 5) Field, truck, and fruit crops Barley X ST Sugar beet X T Rape X Nl Garden beets X T Kale X Nl Asparagus X T Spinach X NI ..,. Rye X NI w Wheat X ST Oats X ST Corn X ST Flax X NI Sunflower X ST Tomato X ST Broccoli X Nl Cabbage X T Cauliflower X NI Lettuce X T Sweet corn X ST Potatoes X ST Bell pepper X ST Carrot X T Onion X T Peas X ST Squash X Nl Cucumber X NI Field beans X T Radish X ST Green beans X T TABLE 17. Continued Salinity Boron Tolerant b Moderately or semi-tolerant Sensitive b (12 to 6) (8 to 4)b (6 to J)b ( 3 to 1 . 5) Field, truck, and fruit crops Apple X s Boysenberries X NI Blackberries X s Raspberries X NI Strawberries X NI Forage crops Sal tgrass X NJ' Bennudagrass X NI Tall wheatgrass X Nl """ Rhodesgrass X NI """ Canada wildrye X NI Western wheatgrass X NI Ta 11 fescue X Nl Barley (hay) X NI Birdsfoot trefoil X NI Sweetclover X NI Perennial ryegrass X NI Mountain brome X Nl Harding grass X Nl Beardless wildrye X NI Strawberry clover X NI Dallisgrass X Nl Sudangrass X NI Hubam clover X Nl Alfalfa X T Rye (hay) X Nl Wheat (hay) X NI Oats (hay) X Nl Orchardgrass X Nl . ---------------- TABLE 17. Continued Forage crops Blue grama Meadow fescue Reed canary Big trefoil Smooth brome Tall meadow oatgrass Mil kvetch Sourclover White dutch clover Meadow foxta i 1 Alsike clover Red clover Ladino clover Burnet Tolerant b ( 12 to 6) SOURCES: Allison (1964), Hem (1970). Salinity Moderately or semi-toler~nt (8 to 4)b (6 to 3)D X X X X X X X X Sensitive b ( 3 to 1. 5) X X X X X X aTolerance to boron is defined as follows: T tolerant ST semi-tolerant S sensitive NI no information for the species of plant Boron a NI NI NI NI NI NI NI NI NI NI NI NI NI NI bNumbers denote the range of specific conductance for each plant group in millimhos/cm at 25°C. other sources, lower, more stringent criteria for N and P have been adopted for use in this inventory in jud~ing the eutrophic potential of streams. Phosphorus levels exceeding 0.2 mg/1 hav~ produced no problems in some potable supplies (USEPA 1973). In uncontaminated lakes, phosphorus has been found in the range of 0.01 to 0.03 mg/1 and higher {Salvato 1958). Federal surveys have indicated that 48 percent of the aquatic sites sampled across the nation had phosphorus concentrations in excess of 0.05 mg/1 (Gunnerson 1966). The EPA (1973) has suggested that total phosphorus in concentrations less than 0.05 mg/1 would probably restrict nuisance plant growths in flo~ling waters. In contrast, much higher concentrations of inorganic nitrogen are neces- sary to initiate algal blooms; studies have indicated that excessive growths of plants are avoided when inorganic nitrogen concentrations are less than 0.35 mg/1 (Mackenthun 1969, 1·1uller 1953). These two values--0.05 mg/1 for phosphorus and 0.35 mg/1 for inorganic nitrogen--can serve as general refer- ence criteria for nitrogen and phosphorus in waters of the Yell011stone Basin. Streams or lentic systems in the basin ~lith total-P (or P04-P if total-P data are unavailable) or inorganic nitrogen (or t!OrN• rW 2+!10rNI concentrations less than 0.05 mg/1 and Q.35 mg/1, respectively, mignt be reliably judged as noneutrophic or oligotrophic. Haters with phosphorus and nitrogen concentra- tions in excess of 0.1 Mg/1 and 0.9 mg/1, respectively {USEPA lg74b), can be judged as eutrophic. Intemer!iate concentrations of P and N (i.e., 0.05-0.10 mg/1 and 0.35 to 0.90 mg/1, respectively) suggest, at a lower degree of pre-· dictive success, potentially eutrophic waters. Other Constituents In addition to nitrogen and phosphorus, a variety of other water quality constituents affect aquatic life. Such effects can be positive and beneficial to the biota of an ecosystem at particular concentrations (e.g., availability of essential clements in appropriate concentrations, appropriate temperatures, adequate dissolved oxygen levels, absence of toxic substances, and appropriate salinity and turbidity levels), but can be detrimental at other levels (e.g., low and limiting concentrations of an essential element, excessively high tem- peratures, lo~1 dissolved oxygen concentrations and high organic loads, pres- ence of toxic substances, high concentrations of TDS and suspended materials). Most commonly, attention is directed toward the potential detrimental effects of these constituents on a biota 11hen their concentrations become too high or too low in a water--either in a toxic-lethal or depressing sense on individual organisms or in the sense of reducing the biomass or number of individuals and species in a conmunity (thereby altering its diversity and structure) and of lowering its primary and secondary productivity. A list of such affecting parameters would include the most obvious--oxygen, temperature, pH, salinity, various common constituents, turbidity-suspended sediment, nitrogen, and phos- phorus--along with the trace elements and such toxic substances as herbicides, pesticides, and heavy metals. Reference criteria for dissolved oxygen, pH, and temperature in 11ontana's B-0 1 , B-0 2 , and B-0 3 streams have been described previously (table 8). The ranges of pR listed for such streams are similar to those recommended by the Commit tee on I·! a ter Qua 1 i ty Criteria to afford a moderate-to-high level of protection in a body of water (USEPA 1973). The 46 criteria for dissolved oxygen in a B-o 3 stream is identical to that recommended by Ellis (lg44) for a mixed, warm-water fish population. Suspended Sediment and Turbidity Concerning suspended sediment, the European Inland Fisheries Advisory Commission (1965) and the EPA (1973) came to the following conclusions: 1) There is no evidence that concentrations of suspended solids less than 25 mg/1 have any harmful effects on fisheries (a high level of protection at 25 mg/1). 2) It should usually be possible to maintain good or moderate "fisheries in waters that rormally contain 25 to 80 mg/1 suspended solids; other factors being equal, however, the yield of fish from such waters might be somewhat lower than from those in the preceding category (a moderate level of protection at 80 mg/1). 3) Waters normally containing from 80 to 400 mg/1 suspended solids are unlikely to support good freshwater fisheries, although fisheries may sometimes be found at lower concentrations within this range (a low level of protection at 400 mg/1). 4) Only poor fisheries are likely to be found in waters that con- tain more than 400 mg/1 suspended solids (a very low level of protection over 400 mg/1). These conclusions form a reference for this important variJble. For the Yellow- stone system, suspended sediment concentrations can be converted to turbidity in Jackson Turbidity Units (JTU) with some degree of precision (r=0.95) using a graph available in Karp et al. (1976b), resulting in the reference system shown in table 18. TABLE 18. Impact reference system for turbidity and suspended sediment. Class of Fisherya Excellent Good to Moderate Fair to Poor Very Poor Suspended Sedi~ent Range (mg/1) <25 25 to eo 30 to 40'l >400 Corresponding Turbidity Range (JTU) <8 8 to 2G 26 to 91 >gl aThis assumes that other factors are not limiting. Table lB's reference levels forsuspended materials and turbidity imply a relatively constant exposure of a fishery to the indicated concentrations (e.g., as expressed by a median value) in order to invoke the associated type of fishery (excellent to very poor), as fish can tolerate relatively high concentrations for limited periods of time (Whalen 1951). Waters with med- ian 1 eve 1 s of suspended so 1 ids and turbidity of 15 mg/1 and 5 JTIJ and occa- sional extremes of 100 mg/1 and 30 JTU ~ould be expected to provide conditions for a better fishery than a stream with medians of 70 mg/1 and 23 JTU and 1' 47 occasional extremes of 150 mg/1 and 40 JTll, and waters with medians of 100 mg/1 and 30 JTU should be more productive than streams with medians of 300 mg/1 and 70 JTU. However," ... although several thousand parts per million suspended solids may not kill fish during several hours or days exposure, temporary ~igh concentrations should be prevented in rivers where good fisheries are to be maintained. The spawning grounds of most fish should be kept as free as pos- sible from fir.ely divided solids" (USEPA 1973). A stream with generally low med- ian suspended sediment and turbidity levels (e.g., <100 mg/1 anJ <30 JTU) but with high and temporary concentrations of sediment at certain periods of the year (e.g., 400 mg/1 and 91 JTU) may be able to Su?port a migratory or stocked fishery in its waters but not a resident (breeding) population, because the pulse of sediment could elimin~te spawning grounds. Salinity The salinity level (dissolved solids concentration) of freshl·;ater lentic and lotic systems is important in the assessment of its aquatic biota as well as in judQing its potenti;;l for irrigation .• ~ccording to the EPA (1973): The quantity an'' rwality of dissolved solids are major fac- tors in cctenr:ining the variety and abundance of plants and animals in ar. aquatic system .... A major change in the quantity or ccmrosition of total dissolved sol ids changes the structure and fur.ction of a~u~tic ecosysteos ... Jlowever," ... such c~anges Jre difficult to predict" (USEPA 1973). Hart et al. (1~45) observed that only five percent of the inland waters supporting a mixed biota had salinities in excess of 400 mg/1 (as specific conductance greater than abotlt 600 umhos/cm at 25°C; however, ten percent of these ~1aters hiid dissolved solid concentratio,,s greater than 400 ng/1. This discrepancy bet~1een percentages r.Jay i 11 us tra te a Lreak i ng point in the success of freshwater co~~unities at 400 mg/1. Ellis (1944) recommends that a maximum specific conductance of 1000 umhos (about 670 mg/1 of dissolved constituents), and possibly approaching 2000 umhos, is penrissible in western alkaline streams in order to support a good mixed fish fauna. Incorporating these sources yields the following general reference criteria: healthy, mixed aquatic communities would be expected to be found in waters with dissolved solid concentrations less than 400 mg/1 given no other affecting factors; some adverse effects might be expected with salinities greater than 4no mg/1 and approaching 670 mg/1. In turn, a salinity in excess of 2000 umhos (about 1350 mg/1) would be detrimental to most freshwater systems. Trace Elements and Toxic Substances In addition to the more common parameters described previously, a variety of trace elements and toxic substances can also dran·:atically affect aquatic systems. These are generally difficult to assess because their effects are often variable among individual organisms and species and are dependent upon the nature of the remaining chemical constituents of a water; for example, effects can vary with the level of hardness in a system. As a result, such 48 factors as acclimatization and antagonistic-synergistic reactions would have to be considered for a complete discussion of one of these parameters in a particular body of water. However, the Corrnnittee on l~ater Quality Criteria (USEPA 1973) has established, for certain of these constituents, recommenda- tions for an absolute or maximum concentration that should be present in freshwater or seawater; lower concentrations could be recor.mended for parti- cular cases. General recommendations from this committee and from other re- ferences for certain of these parameters, including the metals, are summarized in table 19. These recorrnnendations can be used as reference criteria for the corresponding variables in water quality discussions. Recommendations devel- oped by the Committee on Hater Quality Criteria (USEPA 1973) and other sources for other trace elements and toxicants are considered for those streams where appropriate data are available. TABULAR AND STATISTICAL CDNSIDERATIOilS In tables summarizing the water quality information available for the Yellowstone River Basin {primary and secondary inventory areas), the comnon constituents and metals are designated by their accepted chemical symbols. Concentrations are given as milligrams per liter (mg/1). Distinctions are made between total recoverable and dissolved metals. Parameters consistently tabulated through the basin discussions of this report include those for which c!ata are regularly available from the USGS or the state WQB for the various stream stations. Other water quality variables, such as the pesticides, which have less consistent data for the basin, ·will be considered separately for those streams where such data are available. The concentratiuns of critical nutrients {phosphorus and nitrogen species) are listed in the tables according to their P or il components rather than their radical weights; where available, total-P and (N0 2+N03)-N data were used in the statistical determinations; where unavailable, the concentrations of the ortho-PO~;-P anc tiOTN species were used as subsets of the preferred fo~1s. Additional abbrev1ations and concentration units that have been used for other water quality parameters summarized in the tables can be listed as follows: llOD five-day, biochemical oxygen demand (BOD 5 ) in mg/1 DO dissolved oxygen in mg/1 E an estimated flow FC feca 1 co 1 iforms as counts (col on i es) per 100 ml of sample Flow stream discharge in cubic feet per second (cfs); flow in cfs car be converted to flow in cubic meters per second (m3/sec) as fol· lows: m3fsec = 0.0283 x cfs i·1ax the maximum value of a parameter that occurs in a set of data from a particular stream station (high extreme) Med the median value of a parameter that occurs in a set of data from a particular stream station--the middle value in an orderei or ranked set of figures, i.e., 50 percent of the remaining values occur above the median and 50 percent belo~1 the median concentration 49 TABLE 19. Recommended maximum concentrations of trace elements for freshwater aquatic life and for marine aquatic life. Trace Element Al Ag As B Ba Be Cd Co Cr Cu Cyanide Recommended Maximum Concentrations 0.1 mg/1 (B); >I.S mg/1 hazard, <0.2 mg/1 minimal risk (C) >.OOS mg/1 hazard, <.001 mg/1 minimal risk (C) 1.0 mg/1 (A); >.OS mg/1 hazard, <.01 mg/1 minimal risk (C); arsenic tends to be concentrated by aquatic organisms >S.O mg/1 hazard, <S.O mg/1 minimal risk (C) S.O mg/1 (tentative)(A); >1.0 mg/1 hazard, <.S mg/1 minimal risk (C); barium tends to be concentrated by aquatic organisms >1.0 mg/1 hazard, <0. I mg/1 minimal risk (C); based on data from hard freshwater 0.03 mg/1 if hardness >100 mg/1 as CaC0 3, 0.004 mg/1 if hardness <100 mg/1 (B); >.01 mg/1 hazard, <.2 ugrl minimal risk (C); synergistic with copper and zinc about 1.0 mg/1 (tentative) (A) O.OS mg/1 (A,B); >.I mg/1 hazard, <.OS mg/1 minimal risk (C); particularly toxic to lower forms of aquatic life--accumulates at all trophic levels 0.02 mg/1 freshwater, O.OS mg/1 seawater (A); >.OS mg/1 hazard, <.01 mg/1 minimal risk (C) O.OOS mg/1 (B); >0.01 mg/1 hazard, <.OOS mg/1 minimal risk (C) F I.S mg/1 (A); >I.S mg/1 hazard, <.S mg/1 minimal risk (C) Fe <.2 mg/1 (A); >.3 mg/1 hazard, <.OS mg/1 minimal risk (C) Total Hg Mn NH (unioniz~d) Ni Pb 0.2 ug/1 (grab sample), O.OS ug/1 (average)(B); >.I ug/1 hazard (C) 1.0 mg/1 (A); >.1 mg/1 hazard, <.02 mg/1 minimal risk (C); manganese tends to be concentrated by aquatic organisms 0.02 mg/1 (B); >0.4 mg/1 hazard, <.01 mg/1 minimal risk (C) >.I mg/1 hazard, <.002 mg/1 minimal risk (C) <.I m~/1 (A); 0.03 mg/1 (B); >.OS mg/1 hazard, <.01 mg/1 minimal ____ r:_ci sk (C) Phenols Se Zn SOURCES: 0.2 mg/1 (A); 0.1 mg/1 (B); 0.02 m911 to 0.1S mg/1, potential tainting of fish flesh (B); 0.001 mg/1 reference criteria (D) >.01 mg/1 hazard, <.005 mg/1 minimal risk (C) >.I mg/1 hazard, <.02 mg/1 minimal risk (C) (A) McKee and Wolf (1974). (B) U.S. Environmental Protection Agency (lg73) ("Freshwater Aquatic Life and Wildlife"). (C) U.S. Environmental Protection Agency (1g73) ("Marine Aquatic Life and Wildlife"). (D) U.S. Environmental Protection Agency (lg74). l·~in the minimum value of a parameter that occurs in a set of uata from a particular stream station (lov1 extreme) N concentration cf nitrogen species in mg/1 as elemental nitrogen excludin~ organic and ammonia nitrogen H. the number of data points comprising a parametric set of data P concentration of phosphorus species in mg/1 as ele~ental phos- phorus pH in standard units SAR sodium adsorption ratio; see Hem (1970), pp. 228-229, for definition SC specific conductance in ~mhos/em at 25°C TA total alkalinity as mg/1 of CaC0 3 TDS total dissolved solids in mg/1 calculated as the sum of consti- tuents or determined as the 1~ei<:~t of filterdble residue after evapordtion at 82DC (180°F) Temp temperature in degrees Celsius TI-l total hardness as mg/1 of Caco 3 TSS total suspended solids in mg/1 Turb turbidity in Jackson Turbidity Units (JTU) Minimum, maximum, and median values 1 isted for temperature and specific conductance were those obtained fran grab samples rather than from continuous or once-daily records. In addition to the mo1ie common parameters listed previously, miscellaneous constituents can also be i~portant in some instances in reducing the quality of water in streams. As a result, these parameters will also be considered for those streams and stations v1here appropriate data are available. Such para- meters and associated symbols, concentrational units, and related information can be summarized as follows: COD Color chemical oxygen demand in mg/1 is a measure of oxidizable com- pounds in a sample through dichromate reduction (APIIA et al. 1971, USDI 1966-1974b) an aesthetic evaluation in platinum-cobalt units (APHA et al. 1971); color in water is generally caused by unknown, dissolved organic materials of high molecular weight and is generally unnoticeable to the human eye at less than 10 units (Hem.l970) 51 MBAS methylene blue active substance in mg/1; MBAS is a measure of apparent detergents after the formation of a blue color when the methylene blue dye reacts with synthetic detergent compounds (USDI 1966-1974b) O&G oil and grease in mg/1 as measured gravimetrically after petrol- eum ether extraction and evaporation (APHA et al. 1971) TOC total organic carbon in mg/1 Phenols are determined in milligrams per liter following methods outlined in Standard Methods (APHA et al. 1971). :·then large amounts of water quality cata are available, a statistical sum- mary is necessary for each sampling station. In the STOR.ET summaries, the mean, variance, and other statistics from the available data for each parameter are presented for each sampling location. This approach compacts the data and allows for overa 11 comparisons; however, a mean, in most cases, is probab 1 y not the best estimator of central tendency. Since the concentrations of water quality parameters tend to be affected by flow quantities to varying degrees, parametric concentrations do not generally approach a normal distribution but are most often skewed to some extent, which weights the mean. For example, the distribution of dissolved solids levels (concentrations versus the percentage of samples having a particular concentration) may be skewed to the right (high) because high concentrations are obtained for a large proportion of the year at low flows but with a few samples of extremely low concentrations obtained during the high-flow periods of much shorter duration. These low values then can weight the mean concentration of a parameter toward low, so that the mean would not reflect the most common concentration of the constituent over the year. The opposite waul d be true for parameters which have concentrations directly re 1 a ted to flow, e.g., suspended sediment and fecal colifonns, with a weighting toward high producing excessively large means. The EPA (1974b) took a different approach in its National Water Quality Inventory and used the median concentration of a parameter as an expression of· central tendency; it also determined the 15th (low concentration) and the 85th (high concentration) percentiles of a parametric data set which served to illus- trate the degree of dispersion or typical concentration range, excluding the extreme values (USEPA 1974a). With one modification, this approach was gener- ally utilized in the Yellowstone Basin water quality inventory conducted by the state WQB for this study. Since post-1965 data from the basin ~.•ere of insuffi- cient magnitude for the calculation of meaningful 15th and 85th percentiles, the maximum and minimum values of a data sE!t were~used~to indicate the degree of dispersion; these are representative of the true concentration range of a parameter s i nee the extreme va 1 ues are inc 1 uded. In a few cases in which un- iquely high concentrations were obtained for particular constituents, the next highest value served as the maximum value. In general, the median would appear to be a better indicator of central tendency in non-normal data than the mean sin.ce the median provides a definite middle point of reference. Two types of water quality parameters were recognized in this survey: 1) the major parameters most typically considered in water quality 52 surveys (e.g., common ionic constituents, cissolvec! cxyf)en, susper.ded sediment, pH, ar,d critical nutrier.ts) and for ~1:1ich there are ~cner ally ·lar~e amounts of datD; an~ 2) the miscellane·ous COI!Stituents ancl trace ele1cents 11hich are r.ut as commonly cc-nsi~ere~ in ir.vcntories or are rtdateC: to sr.ccific pro- blems (e.g., r·:5AS, fecal strep, cyanide, ve.rious "'£'t~1s, i:il;lE!Onia, anc so forth) anc/or for whic:1 data Dt'e cotl!parat.ively sparse in r:,ost cases. Due to t~cse differences, wo t'istinct approac!1es were used in t~c statistical sumnaries of these t1·10 pJrantct;·,r ~roups. P.n attempt 1·:as l'ladro to classify accerciin~ to flo~; ull of t!J~ ,:a::u ;;vail- able for tile mJjor llarilr.let•?rs at eJcl': samplin9 station. This classification, bilsed primarily on the dischDrge cycl£ of the Ye 11m,stone f:ivcr, cor.sistt'd of fuur periods: r.wnt~s •,;hich gr:nerJlly have r,igl! fltMs (s;:t·ing runoff ir. :::ay, June, and July), ~1ann-weat;1E>r lo~: flows (llusust, Scnen:ber, ctnd C:ctobo.r), cclt:- weather lov; flows ('/over.lter, Decer,tbe:r, January, a11d February), or spring fliNS (March and April). The :larc'l-t.pril Period ~1as distirguis!led becJuse pany (;f the lowland streams have a rur.off period at this tk(!, earl i•"r· t~an the 'lay- July runoff period in strea~s with mountaincus origins. Parametric ~edians and ranges were then detenni neG frorn these seJsona ll :• c 1 ass i fi ed s uilsets cf data. For stations (typically the non-USGS sites) or~ 1·1hich datil fur tile r;ejor purameters 11ere missin!) for some se>asor.s or for l'i:1ic'1 onl:• a few n~aJir~~·s werr: available for this seasonal separation, t'le data •·ter(· dir~ctly cla:;sifie<.: ac- cording to flo1·1 (where possihle) l)y C:evelc;.>in<; ti'!C ~.L;bsets of ;Jurar.ietric values--one for samples obtained during reliltively fiigh flows (>8.0 cfs) ar.d one for samples obtained dllring lm~-flo"' periods (<i!.IJ cfs in t!:is ir:stance). Medians and muximum-r.lir.i"luni values fc;r e,ach pararr,eter •·t~re tl~en uetcrr.lined fr01.1 these flow-classified subsets. For some stations, datJ 1·1ere insufficient for even tllis latter type of separation, and the pilrametric filedian, maximum, and r.linimur:1 Villues for these stations were cleterminec from the entire set of uata. In some instances, llat•?r quality data from closely related stations on a stream were cumbir.eci <~nd t:1e statistics then determined eithtr directly from the conbined sr!t of data or from subsets as described dtovc. Statistics th~s derivcc would ~escribc a strear.1 reach rather than a specific location. For some draina9c· areas, data from closely associated streams 1·:ere co1~bined tc increase the sa:;;ple size, this uat;, would describe a region rather than a streum lccaticn or reac11. In all 1·1ater quality tables presented in the follo~ling section of this report, tfle sample sizes of each of the parameter-data sets (~) invclve~ in the median, maxinum, and minimum deten;linations are given to ~rovide J basis for judging reliability. Due to the ')eneral lack of information, no attempt was made to classify by flow the miscellaneous consti~uents or trace elements. In most instances, data for these pilrameters from t1vo to several adjacent locations on a streafil or from several stations on associated strear.1s in a drainage were ilmalgamdted to increase sample size for the median, maximum, and minir;Jum determincttions. 51 Through these various statistical approaches, some order should be im- parted to the large amounts of diverse water quality data now available for the Yello~1stone River Basin. Some meaningful conclusions concerning the status of water quality in the drainage might then be derived from this data. IMPACTS OF WATER WITHDRAWALS DESCRIPTION OF METHODS Introduction TDS was the principal water quality parameter modeled; it was chosen for severa 1 reasons: 1) it can be a limiting factor for several beneficial uses, including drinking water, irrigation, industrial, and fish and aquatic life; 2) common constituents and hardness generally are linearly related to TDS; 3) adequate records of TDS are available from publications of the USGS; 4) TDS is relatively easy to model, being a conservative substance that is transported with the water; 5) for a given reach of stream, TDS is highly correlated with electri- cal conductivity, which can be measured easily and inexpensively; and 6) TDS is an indicator of the overall chemical quality of the water. Nonconservative parameters such as temperature, dissolved oxygen, bio- chemical oxygen demand, and coliform bacteria generally are not a problem in the Yellowstone River Basin. Detailed analysis of these parameters was not a primary goal of this study; however, streams on which future development seems likely to adversely affect nonconservative parameters are identified. General The basic principle governing the analysis is that mass must be conserved. All water and dissolved minerals available to the basin in~a given-time period (a month in this case) will be removed permanently from the system, stored temporarily for release later, or discharged from the basin via the stream or groundwater during the same month. The quantity of water available is ob- tained from hydrologic simulations (refer to task 9); the corresponding salt load is computed from regression equations relating average monthly TDS to total monthly discharge. Figure 2 illustrates the gross movement of water and salt within the basin. The following equations account mathematically for the water and salt: 54 Undi verted Qu, LTDSU Total Availab 1 e Energy Diversions QE, LTDSE ' ' ' ' lrrigat1on Diversions Q1 , LTDS 1 ' ' ' ' --- Municipal Diversions ------ ...... )>' .... ---.-----'----=---, Depletions Q0 , LTDS 0 Net Flow leaving Basin QN' l TDSN Figure 2. Simplified diagram of water and salt movement. 11 ON= Or-OE-Or~ 0M +OR 2) L TDSN = L TDST -LTDSE - L TDS I -LTDSn + L TDSR where: ON is net flow leaving the basin QT is total flow available before OE is diversion for energy Or is diversion for ne1·1 i rri gat ion Or1 is diversion for new municipal OR is return flow LTDSN is net salt load leaving the LTDS 1 is total load of salt in QN LTDSE is salt load in QE LTDS 1 is salt load in Or 55 diversions use basin L ms~1 is salt load in QM LTDSR is salt load in QR The flows are in acre-feet and salt load trations 3) of TDS in mg/l is L TDS TDS = Q (.00136) calculated as is in tons. Therefore, the concen- follows: The equations are applied for each month. Additional details are described in the following sections. Regression Equation for TDS Published records of the USGS ~1ere used to obtain basic data on discharge and TDS. Water quality data are reported as concentrations (mg/1) for periods usually ranging from one to thirty days. Samples are collected daily and com- posited by discharge before analysis so that results represent discharge- weighted averages for the compositing period. Published values for TDS were weighted by water volume for each compositing period during a month in order to obtain monthly discharge-weighted values. For example, the following in- formation was·published for the Yellowstone River at ~1iles City: Date Nov. 1-12, 197 4 Nov. 13-30, 1974 Discharge ll , 200 cfs 9,740 cfs TDS 503 mg/1 477 mg/l The discharge-weighted average monthly TDS is computed as follows: TDS = 12 X ll , 200 X 503 + 18 X 9, 7 40 X 4 77 = 488 mg/l ave 12 x ll,200 + 18 x 9,740 · Where the compositing period covered parts of two months, the water volume was linearly apportioned according to the number of days in each· month cov- ered by the composite analysis. The quantity of dissolved minerals in natural water is orimarilv a func- tion of the tvoe of rocks or soils with ~1hich the water has been in contact, the duration of contact, and the oH of the water. Groundwater; which-supplied much of the flow in dry, low-flow months is normally more highly mineralized than surface runoff. Hence, TDS of water in the stream is usually less when streamflo~1 is high because surface runoff tends to dilute the base flow from groundwater. Both surface runoff and groundwater, h011ever, vary in quality with time and location in response to natural geologic and hydrologic pheno- mena and as a result of man's activities such as agriculture, mining, oil well drilling, and industrial and municipal pollution. Consequently, the expected inverse relationship between TDS and Q may not be well-defined mathe- matically for all stations, or the "best-fit" equation may take different forms for different stations or for different periods of the year at a given station. 56 I Regression equations were obtained for TDS (average monthly total dis- solved solids in mg/1) as a function of Q (total monthly discharge, acre-feet). Resulting equations were of the following forms: 4) TDS = a + b Q 5) TDS = c + d log Q 6) log TDS = e + f log Q 7) 1 og TDS = g + h Q Generally, data most often fit equations 5 and 6 better than 4 or 7. Equations were obtained for all stations in the basin with adequate records. For some stations, sufficient records were available to enable equations to be derived for each month of the year. Equations were tested for statistical significance using tables developed by 2Snedecor (1946). Generally, the significant regres- sion equations produced r values ranging from 0.60-0.90, indicating that Q accounted for 60 to 90 percent of the variation in TDS. Conservation of Water and Salt Generally, water quality records for 1951-1974 were used to develop the regression equations. No station, however, had more than 19 years of record during this period; most had less. It was assumed.that these data represented the normal situation, i.e., the cause-effect relationship was constant. For calculation purposes, any changes in the causative factors were assumed to be superimposed upon the normal relationship. For example, the Q the TDS used in deriving the regression equ*tions represent the ''total available'' values indi- cated in figure 2. The QT and LTDST are for the basin outfl 01~ under norma 1 conditions. Therefore,-in order to ase the equation derived for TDS versus Q, Q must be the normal unaltered value at the basins outlet, which then makes it r lssible to obtain the corresponding normal TDS. Once QT and LTDST are established (see the explanations below for columns 1, 2, and 3), the logic of figure 2 and equations 1 and 2 can be employed. Table 20 illus- trates the application of the regression equations and equations 1, 2, and 3 to a representative subbasin, the Tongue River. An explanation of each col- umn is presented below. Column 1. flow that would occurring under Total Available, Hater (af). These numbers represent the pass Miles City if no diversions occurred other than those normal conditions; in other words, historical flows. Column 2. Total Available TDS (mg/1). the regression equations between TDS and Q, For April the appropriate equation is TDS = yields a TDS of 580 for a Q of 21,888. These values are obtained from using column 1 values for Q. 1524.7-217.70712 log Q, which Column 3. Total Available TDS (tons). The load of dissolved salts in tons is obtained from equation 3 by multiplying column 1 x Column 2 x 0.00136 (a conversion factor). Column 4. Enerav Diversion. Water. The amount of water diverted for energy purposes, given from the level of development assumed. 57 c.n OJ TABLE 20. Sample calculation of TDS in the Tongue River at Miles City assuming a low level of development. ( l ) (2) ( 3) (4) (5) (6) (7) ( 8) (9) ( l 0) ( 11) ( 12) Irrigation Month Total Available Energy Diversion Diversion Return Flow Outflow QT TDS LTDST QE LTD\ QI LTDS 1 QR LTDSR LTDSN QN TDS (a f) (mg/1) (tons) (a f) (tons) (a f) (tons) (a f) (tons) (tons) (a f) (mg/1) Apr 21 ,888 580 l 7 '265 g55 753 220 174 293 471 16,809 21 ,006 May l68,gg8 347 7g,754 955 451 2,855 l '347 805 l ,294 79,250 l65,9g3 June 299,879 186 75,857 955 242 3,730 944 1,025 l ,647 76,318 296,219 July 24,285 370 12,220 955 481 7,030 3,537 l ,318 2,117 10,319 17,618 Aug 7,859 510 5,451 955 662 5,490 3,808 l ,317 2 '117 3,098 2 '731 Sept 8,549 535 6,220 955 695 2,415 1 '757 732 1 '176 4,944 5,911 Oct 5,458 655 ' 4,862 955 851 200 196 585 941 4,756 4,868 Nov 17,487 592 • 14,079 955 769 0 0 366 588 13,898 16,898 Dec 14,643 672 ' 13,383 955 873 0 0 293 471 12 '981 13 '981 : Jan ll ,647 677 I 10,724 955 879 0 0 220 353 l 0.198 10,912 Feb 12 '734 586 I 10 '148 955 761 0 0 146 235 9,622 11 '925 Mar 28,346 479 . 18,466 955 622 0 0 220 353 18,197 27,611 Annual 621,773 317 268,429 11 ,460 8,039 21,960 11 '763 7,370 11 '763 260,390 595,673 NOTE: These calculations are based upon 100 percent of the Northern Great Plains Resource Program fish and game flows; salt pickup 0 ton~ per acre (1944-1945). 588 351 189 431 834 615 718 605 683 687 593 485 321 , , Column 5. Enerqy Diversion, Salt. The amount of salt dissolved in the water diverted for energy, obtained from equation 3 by multiplying column 4 x column x 0.00136. Column 6. Irrigation Diversion, Water. The amount of ~tater diverted for irrigation during the month, given from the level of development assumed. Column 7. Irrigation Diversion, Salt. the water diverted for irrigation, obtained column 6 x column 2 x 0.00136. The amount of salt dissolved in from equation 3 by multiplying Co 1 umn 8. Return Flow, Hater. The amount of return f1 ow that appears in the stream during the month. It was assumed that energy diversions ~~ould pro- duce no return flow and that one-third of irrigation diversions and· one-half of municipal diversions would eventually return to the stream. Return flo1~ is allocated according to the follo1~ing percentages of the total annual return flow, beginning with April: 4, ll, 14, 18, 18, 10, 8, 5, 4, 3, 2, 3 (Koch 1977). Therefore, the total annual return flo~t is one-third of 21,960--7,320. Four percent, or 293, return in April; eleven percent, or 805, in 11ay; and so forth. No municipal diversions were made under the level of development il- lustrated, but had there been a municipal diversion, one-half of the vearlv total ~tould have appeared as return flo~t. distributed in the same manner as irriqation return flm~. This assumPtion ~tas made for ease of calculation. Actually, most water used for domestic purposes will be returned to the stream durinq the month it is diverted. Onlv that portion used for irriqation of lawns, parks, and cemetaries will behave as irriqation return flow. In all levels of develoPment, ho~tever, municipal diversions ~tere so small (less than three Percent of total diversions) that no further refinement ~tas deemed nec- essary. Column 9. Return Flow, Salts. The salt load that will return to the stream is unknown and varies from place to place. Ideally, return flow from irrigation should remove, as a minimum, the salt contained in the applied water. Otherwise salt will accumulate in the soil and eventually reduce productivity. It is common where water is plentiful to over-irrigate, a practice which often leaches naturally occurring salts from the soil. Under the assumptions of this study, over-irrigation would not occur; thus, leach- ing should not be excessive. For purposes of analysis, three levels of salt pickup l·tere considered: zero, one-half, and one ton per acre per year. The total at the bottom of column 9 represents the dissolved salt in the irriga- tion return flow. It is obtained by adding zero, one-half, or one ton per acre times the number of acres irrigated to the salt in the applied water, the total of column 7 (in the example, zero salt pickup is assumed). This load was distributed monthly according to the distribution used for column 8. The quality of irrigation return water can vary considerably throughout the year in response to a multitude of factors: quantity of applied water, quality of applied water, method of irrigating, type of soil, crop, growth stage, drain- age sys tern, and others. ilorma lly, some return flow will perco 1 ate through the soi 1 and return as subsurface return flow, which is usually higher in dis- solved salts than surface return flow. Obviously, return flows in the non- irrigation months (November-f1arch) will consist entirely of subsurface flows and will have a higher concentration than return flows during the irrigation months (April-October) when a portion of the return flow is surface. With 59 the low application rates assumed in this study (three af/acre), surface re- turn flows will probably be small. It is likely that subsurface return flows, which should exhibit more uniform concentrations. will predominate. There- fore, no attempt ~1as made to differentiate in quality between surface and subsurface return flows. The value for April, for example, is simply four percent of the annual total of 11,763 tons. Column 10; Outflow, Salt. Salt load is obtained from equation 2: col- umn 10 = column 3 -column 5 -column 7 + column 9. If municipal diversions had been significant, they would be subtracted. Return flow from municfpal diversions would be added. Column 11. Outflow, Uater. The values o_f QN in the table were obtained from equation l: column ll = column l -column 4 -column 6 + column 8; muni- cipal diversions, if significant, would be handled as described in the pre- vious paragraph. These illustrative calculations follow the logic of figure 2. Actually, however, values for Q were simulated by the hydrologic model (refer to task 9, Hater Model Calib~ation and River Basin Simulations for an explanation of the model). Basically, the model used more refined techniques to simulate 1~ater movement in the basin, so the resulting basin outfl0\·1 was used for Q~ instead of the value from equation 1. Column 12. TDS of Outflow (mg/1}. The concentration of the basin out- flow is obtained from equation 3: column 12 = column 10 7 column 12 7 0.00136. Adjustments for Storaqe The procedure outlined above assumes that the historical relationship be- tween TDS and Q will be preserved, subject only to the effects of diversions and return flows under the various levels of development. Construction of a dam, however, 1·1ill alter the relationship between TDS ·and Q below the dam by virtue of the storage and mixing that occurs within the reservoir. The effects of an impoundment can be evaluated if the waters of the reservoir are suffi- ciently mixed so that an assumption of complete mixing of inflow and storage does not lead to large errors. If stratification occurs, the complete mixing assumption is invalid, but the state of the art generally does not permit a prediction of the stratification of planned reservoirs. The simplest technique assumes that reservoir outflow during a given ttme period is of constant quality. Further, it is assumed that inflow occurs in- dependently of outflow and that reservoir quality is determined by both a salt and water balance at the end of the time period. The reservoir lessens 1~ater quality variations, with a slightly higher mean concentration (because of evap- oration l. The equations·for the quality of reservoir water and discharge are given belo~1. For ~~ater: fiO where: VI l pl = El = = volume in reservoir (storage) at end of month 1 = volume in reservoir at end of month 0 (or at beginning of month 1) = volume of inflm1 to reservoir during month precipitation on reservoir during month 1 evaporation from reservoir during month vo 1 = volume of outflow during month 1 For salt: where: VR 1 , VR 0 , VI 1 , and vo 1 are volumes described previously and CR 1 = concentration of water in reservoir at end of month 1 CR 0 = concentration of water in reservoir at beginning of month 1 (end of month 0) Cll = concentration of inflow during month 1 co, = concentration of outflow during month 1 Note that precipitation and evaporation are assumed to have 0 concentrations. In applying equations 8 and 9 all quantities must be known except the out- flow (volume and quality) and final reservoir storage (volume and quality); that is, VR 1 , CRj, V0 1 , and C0 1 . The re 1 at i onsh i p between water quantities, VR and VO , wil be aeterminea by the operating rules for the reservoir, re- sulting in 1 three equations and four unknowns. The necessary fourth equation is obtained by making an assumption regarding CR and CO. One approach is to assume complete mixing of reservoir contents before outflow occurs, or CR 1 equals co,. Combining this assumption with equations 8 and 9 yields the following: 10) The analysis is repeated for successive months until the quality routing is completed. Other assumptions involving CR and CO are possible, such as aver- aging inflow and outflow quality at the beginning and end of each month and using an iterative process, but equation 10 was used in this analysis. 61 The historical relationship between TDS and Q is used to obtain inflow quality (CIJ) from inflow quantity (VIJ) vr 1. The other quantities were avail- able from the hydrologic simulations. Equation 10 was used to obtain the qual- ity of reservoir outflow (COl), which became the basis for the calculations outlined in figure 2. In effect, the quantities of water and salt represented by V01 and C01 replace QT and LTDST in equations 1 and 2. Thereafter, calcul- ations proceed as described previously. Adjustments for Upstrea~ Changes in Water Quality The historical relationship between TDS and Q at a given point in a river can be altered also by changes in diversion patterns upstream. Sub- stantial diversions for irrigation above Miles City, for example, would in- crease TDS concentrations and render invalid the equation based on historical records of TDS and Q at Sidney. Therefore, calculations for the two subbasins with major new upstream diversions, the mid-Yellowstone and lower Yellowstone, required significant modifications to the basic procedure described previously. Essentially, such modifications consist of adding the increased salt produced by diversions above the subbasin in question to the salt load at the mouth of the subbasin calculated assuming no change in the TDS-Q relationship. The procedure is demonstrated by the following example for the mid-Yellowstone subbasin. 1) First, the procedure outlined in figure 2 using the regression equation between TDS and Q to obtain the initial TDS was followed to produce simulated Q and TDS values. These values reflect only the effect of diversions within the subbasin. 2) The flow at t1iles City essentially is the sum of discharges from two other subbasins, the upper Yellowstone and the Bighorn. Therefore, adjustments to the TDS values from step 1 were based on the difference il) TDS (for the two upper subbasins) between historical and simulated TDS concentrations for identical dis- charges. For example, from step 1, Q and TDS for the Yellm1stone at t~iles City during August 1954 would be 215,827 af and 673 mg/1, respectively for the high level of development. During the same. month, the discharge from the Bighorn would be 31,549 af. His- torically, the Bighorn flow of 31,549 af in August would produce a TDS of 475 mg/1; under the high level of development, however, TDS would increase to 564 mg/1. Therefore, the Bighorn would contribute, under the high level of development, 31,549 x (564 ----~ 475) x .00136 = 3,819 more tons of salt than it would naturally (1 mg/1 = 0.00136 tons/af). Similarly, the upper Yellowstone would contribute 204,654 af of water with a concentration 1.5 mg/1 higher than naturally, or 204,654 x 1.5 x .00136 = 418 tons more. Of the August 1954 flow of the mid-Yello~1stone, 4.8 percent would be diverted for energy use which has no return flow. Thus, only 95.2 percent of the additional salt would leave the subbasin at Miles City. Consequently, .952 (3,819 + 418), or 4,034 tons must be added to the salt load of the Yellowstone River at 1·1iles City during August 1954. The adjusted concentration would be 687, or 14 mg/1 (2 percent) higher than the value simulated, ig- noring upstream effects. 62 ' I r t INTRODUCTION Many diverse and complex phenomena, both natural and man-caused, influence water quality in streams of the Yellowstone River Basin. The major water qual- ity problems are associated with man's activities. Those described in this section include mining, coal-fired power plants, synthetic fuel plants, slurry pipelines, municipalities and industries, agriculture, and construction. Also discussed are methods of alleviating water pollution resulting from these acti- vities. Treatment systems are well established for some pollutants, such as domestic waste; control methodologies are not well defined for other pollutants, such as nonpoint wastes and effluents from synthetic fuel plants. Acceptable and potentially acceptable techniques for treating or controlling wastewaters are described. MINWG Large-scale surface mining of coal in the northern Great Plains is a rather recent development. Consequently, the long-term effects of surface mining on the environment, including water quality, have not been fully documented. The NGPRP (1974) study included a general discussion of water quality impacts asso- ciated with coal mining. Van Voast (1974), Van Voast et al. (1975), Hodder (1976), Pollhopf and Majerus (1975), and Van Voast and Hedges (1975, 1976), have reported results of research on the effect of Montana strip mining on water qual- ity, but few data are available on water quality after strip mining ceases. On- site water pollution problems of Montana mines are categorized and discussed below. DRAINAGE WATER In many cases coal beds are aquifers. Re~oval of the coal results in an accumulation of water in the pit being mined, necessitating its drainage. Al- though water occurring naturally in the coal bed may be of potable quality, activities resulting from mining can contaminate the water with silt, coal fires, oil and grease from machinery, nitrates from blasting agents, and sulfurous or other compounds, including undesirable trace elements dissolved from the coal or overburden. Discharge of pit water would require a permit from the Montana DHES. The discharge permit 1~ould specify allowable levels of contaminants in the ef- fluent. Treatment may be required in order for the effluent to meet the criteria specified in the permit. Often pit water will be stored and used for dust control. EROSION AND SEDIMENTATION Strip mining severely disturbs the surface of the ground not only in the mining area, but also in the provision of ancillary facilities such as roads, buildings, parking lots, water control structures, crushing and screening 63 facilities, and loading areas. Any surface disturoance increases the erosion potential and changes the quality of runoff. Montana law requires that during active mining, sedimentation oasins oe constructed to contain sediment within mine ooundaries. Proper grading, reapplication of top soil, and establishment of vegetation will minimize erosion and sedimentation after mining ceases. The Bureau of Land Management (1975) estimates that at the Otter Creek Coalfield, annual sed- iment yield of the overourden after the soils and perennial vegetation have stabilized will be approximately the same as oefore mining, out sediment yields will be approximately douoled during the five-to-ten-year reclamation period. The maximum potential for erosion occurs immediately 3fter grading and oefore vegetation has developed a root system. If seeding is done in the spring, it coincides with the period of intense thunderstorms, which, combined with vulner- able soils, can produce substantial erosion. Such an event in May 1976 at Western Energy Company's mine near Colstrip severely eroded a newly planted reclamation site and filled a settling pond. The automatic discharge device for the pond failed to operate, necessitating the release of sediment-laden water into a trioutary of Rosebud Creek (Schmidt 1976). Thus, prevention of water pollution by surface runoff depends to a large extent on the success of reclamation. If reclamation is successful in retaining rainfall on the soil, runoff and erosion will be reduced accordingly. Jensen (1975) describes a project to maximize moisture retention by mechanically mani- pulating the surface to create depressions which reduce surface runoff and im- prove plant growth. Success of that project and others led Hodder (1976) to conclude that "in general, water pollution problems associated with mining in Montana have been minimal as far as surface water is concerned." LEACHING Over geologic time, natural drainage systems have developed within soil and rocks overlying coal beds. Strip mining entails removal and stockpiling of this overburden and the destruction of those drainage systems. After mining, the overburden is replaced prior to grading, topsoiling, and revegetation. There- sultant drainage pattern, both surface and subsurface, will differ considerably from the old, due to the general lowering of the ground surface, elimination of the coal seam (which might have been an aquifer), and refilling the pit with a heterogeneous mixture of soil, rock, and waste coal--which may become a new · aquifer. Consequently, overburden material which was in contact with water infre- quently or not at all before mining, may be used to refill the void left by removal of the coal seam. This material may oecome saturated and thus contin- uously exposed to the water's persistent solvent action. Therefore, after min- ing and reclamation are completed, groundwater in the spoil areas could be more highly mineralized than water in nearby undisturbed aquifers. This has oeen documented by Van Voast and Hedges (1975) for the Rosebud Mine near Colstrip. But, they point out, although" ... alterations of groundwater quality will occur within the downgradient from mined and reclaimed areas ... the simple acknowledgement of hydrologic effects has little meaning without establishment of their significance.'' fi4 I ~ The crux of the matter is the significance of changes in groundwater qual- ity caused by strip mining: the degree to which such changes would be detri- mental to the aquifer, whether toxic elements would travel downgrade and _render the water a health hazard for humans and livestock, whether undesirable chemi- cals would discharge via the groundwater into a stream and adversely affect fish and aquatic life, wildlife, and beneficial uses of the stream's water, whether water quality in the spoils would improve or deteriorate with time, and whether effects would be localized or contaminate entire aquifers downstream of the mine. These and similar questions can be answered only with time and con- siderable field data. Also, answers valid for one site may not be valid at another because of differences in geology, hydrology, precipitation, and other physical and chemical factors. Van Voast and Hedges (1976) have summarized hydrogeologic conditions near Colstrip for areas undisturbed by mining, areas currently being mined, and areas that were mined and abandoned or reclaimed. Among their observations are the following: 1. Water qua 1 i ty data "exemplify the striking 1 ack of uniformity or predictability of groundwater quality in the Colstrip area." Water quality varied widely at different locations and depths, even within the same aquifer. Spoils in younger parts of the mined area contain waters that are chemically similar to waters from undisturbed aquifers, but water from older spoils is more mineralized than water in nearby undisturbed aquifers. 2. ''Occurrences and concentrations of trace elements in mine-area waters are sporadic and do not relate definitely to past mining operations." 3. ''Chemical qualities of active-mine effluents will be similar to those of other area waters; dissolved solids concentrations will range between 500 and 3,000 mg/1. Leachates from spoils will probably have dissolved solids concentrations ranging between 1,000 and 5,000 mg/1, of which the principal constituents will .be magnesium and sulfate, and the general quality of groundwater in the mined areas will ultimately alter to become more representa- tive of waters in other non-coal aquifers." Van Voast and Hedges (1975), through research on areas before, during, and after strip mining and with the development of simulation techniques believe that potential hydrologic effects (including water quality) of "future mine operations will become predictable." In the interim, the safe approach re- quires thorough monitoring of groundwater quality downgrade from active and reclaimed mining areas in order to detect significant changes in undesirable or potentially toxic substances before they reach hazardous levels. MISCELLANEOUS Several other activities at a mine have the potential to contribute to water pollution, including the following: fi5 Sanitary Facilities Wastewaters from showers, washrooms, bathrooms, cooking and eating facili~ ties, and cleaning operations should present no unusual difficulties if proper treatment and disposal systems, e.g., lagoons or septic tanks, are used. Equipment Wastes Equipment maintenance requires the handling of a variety of substances, in- cluding fuels, lubricants, and antifreeze, which, along with detergents used in cleaning operations, are potential pollutants. Disposal sites for these wastes should be located where the threat of water pollution is minimal. Air-borne Wastes Water pollution can result from air-borne contaminant.s such as soil and coal dust from construction, haul roads, crushing and loading, wind erosion, and chemicals emitted from diesel and gasoline engines. Coal Washing Although no mines in Montana presently wash the coal before loading, it may become necessary in the future at existing or new mines. If so, additional water would be required by the mine and another wastewater stream would be created. It is likely that wash water would be recycled to avoid a discharge, and that solid material washed from the coal ~10uld be evaporative-dried and ·eventually buried. CONTROL OF WASTE\1ATERS FROM MINING Mining techniques to minimize water pollution are described by Persse (1975). Possible methods of controlling water pollution at strip mines include the fol- lowing: 1. Water collected in the pits can be pumped to storage basins where settleable solids will be deposited. If the decantate is of sufficient quality, it can be discharged; otherwise, it must be treated or stored until evaporated. Often pit water will be used for dust control or irrigation of reclaimed land. 2. Diversion channels can be constructed to direct surface run- off away from the highly erodible spoil piles. 3. Sediment basins can be formed to collect internal surface runoff from spoil piles and thus prevent sediment from leaving the mine area. If necessary for flood control or to prevent surface runoff from polluting streams below the mine, the sediment-control basins could be expanded to act as storage reservoirs during the period of active mining. fifi I I I I I ~ r I , ,. 4. Reclamation can be designed to retain precipitation on-site to be used by vegetation, and thereby minimize surface run- off. 5. Known toxic spoil material can be buried between impervious layers or otherwise separated from contact with water. 6. Haste oil and other substances resulting from equipment maintenance can be stored in leak-proof containers for pos- sible recycling, or disposed of in a manner to prevent water pollution, such as oiling roads or placing in imper- vious landfills. 7. Properly designed and operated septic tank systems or lagoons can be used for treatment of sanitary waste. POWER PLANTS A modern coal-fired electric generating plant burns coal in a boiler to produce high temperature and high-pressure steam, which passes through a tur- bine where the thermal energy of the steam is converted to rotating mechanical energy. The turbine transfers energy to the generator, which produces electri- cal energy. After turning the turbine, the steam enters the condenser, where energy is transferred to the cooling fluid, and the steam reverts to the liquid phase. This last step produces very low pressure on the outlet side of the tur- bine, necessary for efficient operation of the plant. The lower the outlet pressure, the higher the efficiency; the more heat absorbed by the cooling fluid, the lower the pressure wi 11 be; and the lower the temperature of the cooling fluid, the more heat will be absorbed. Due to inefficiencies in the conversion processes, energy is lost at each step in the process. The laws of thermodynamics limit the overall efficiency of a coal-fired plant to approximately 40 percent. Hence, each kilowatt hour (KWH) of electricity (one KWH is 3,413 BTU's) requires a "heat rate" of ·3,413 ~ .40, or 8,533 BTU's. Some energy, approximately ten percent, enters the atmo- sphere through the smokestacks. Another five percent is lost within the plant. So the heat that must be rejected to the cooling system is equal to .85 x 8,533- 3,413, or 3,840 BTU/KWH, which represents 45 percent of the energy.obtained from burning the coal. Thus, for each 100 units of energy introduced into the plant, 40 leave as electricity, ten go up the smokestack, five are lost within the plant, and 45 are rejected to the cooling system. Two fluids are used to absorb the heat rejected in the condenser: water and air. Presently, only one plant in the United States--the 30 MW l~yodak unit in northeastern Wyoming--uses air as the cooling medium in dry cooling towers. All others require water. Although power plants use water for other purposes such as boiler feedwater to supply the stream, in ash handling and stack gas cleaning, and service water for drinking, cleaning, and sanitary purposes, more than 95 percent of the 1~ater requirement in a wet system is for cooling. The advantages and disadvantages of various cooling devices are discussed by Thomas (1975) and Moseley (1974). For the northern Great Plains, estimated 67 net consumption would range from approximately seven af/y per megawatt capacity for once-through cooling to up to twenty-one af/y per megawatt capacity for spray ponds. Dry or hybrid systems (devices which use both air and water as cooling mediums) theoretically could be designed to use little or no water. However, no such systems have been built in the United States for large power plants. Closed-cycle wet cooling systems are designed to alleviate thermal pollution associated with once-through cooling. However, use of these devices does not en- tirely eliminate environmental problems. Fogging, drift, icing, and steam plumes may occur downwind. In addition to cooling, water is used for several other im- portant functions in a coal-fired power plant. Each of these functions can con- tribute its own characteristic waste. Sanitary wastes are not unique to a power plant so they will not be discussed. More important are the wastes from: (1) the condenser cooling system, (2) boiler feedwater treatment operations, (3) plant system cleaning water, {4) exhaust gas treatment system, and (5) solid waste handling system. Where once-through cooling is not possible, auxiliary offstream cooling de- vices such as cooling towers and ponds are required. Since these devices, with the exception of dry towers, rely primarily on evaporation for cooling, total dissolved solids gradually become more concentrated and can lead to precipitation of solids inside the condenser. Calcium sulfate and calcium carbonate are often the controlling compounds; thus, recirculating water must stay below their solu- bility limits. Clogging also may result from silica, iron, and silt in the cooling water. Therefore, chemicals routinely are added to recirculating water cooling systems to prevent clogging, scaling, and biological growth in the condenser. Boies et al. (1973) discuss the various methods employed to control these poten- tial problems. Chemicals used include alum, ferric chloride, or sodium alum- inate (for coagulation), lime (for softening), acid (to control pH), zinc- chromate-phosphate inhibitors {for corrosion prevention), phosphonate compounds and various polymers (for scale prevention), and chlorine and biocides (for control of biological growth). Water treated with these chemicals is flushed periodically through the condenser and subsequently removed from the cooling system. This "blowdown" can be heavily contaminated with TDS and suspended solids, plus residues of the chemicals added to the water. Similar wastes are released from the boiler feedwater treatment system and from boiler blowdown. Without extensive treatment, blowdown could not be discharged into Montana streams. It is likely that blowdown would be placed in ponds constructed to prevent outflows and seepage. Hater would evaporate, theoretically leaving the impurities in permanent storage. Flue gas desulfurization systems based on the use of lime or limestone nec- essitate the disposal of large quantities of sludge. Pending and landfilling currently provide the major means for disposal of these sludges. This sludge is a potential source of both surface and groundwater pollution, depending upon the characteristics of the waste and the disposal site. Potential water pollu- tion problems are the following: 68 I I I ~ 1 I 1) soluble· toxic species; e.g., heavy metals; 2) chemical oxygen demand; 3) excessive total dissolved solids; 4) excessive levels of specific species; e.g., sulfate and chloride; and 5) excessive suspended solids. Bottom ash is usually transported by water to settling ponds. The water can evaporate, seep into the groundwater, or be discharged into a stream. The decantate has a high pH and a high concentration of TDS (approximately 5,000 mg/1). In addition, it is expected that trace quantities of arsenic, barium, copper, iron, mercury, lead, and other elements ~1ill be present in solution or in suspension in the decanted water. It is anticipated that the sludge generated from wet scrubbing processes and the bottom ash will be stored in ponds or used in landfill. For coal of one percent sulfur content and ten percent ash (typical-Montana coal), the vol- umes of sludge and ash will be approximately 85 and 215 tons of dry solids per megawatt per year (Casper 1975). With average dry densities of 42 pounds per. cubic foot (pcf) for scrubber sludge and 85 pcf for ash, a 1 ,000 MW plant would produce more than 200 af of dry solids per year. Ash is relatively easy to de- water but sludge is not. Therefore, the solids probably would require a volume of 400-500 af/y for storage. Waters used to transport this material, as well as other wastewater from a power plant, obviously have the potential to degrade receiving waters and dis- rupt aquatic life. Under Montana regulations, discharges of sludges and water from sludges to waters of the state generally would not be allowed. It is lik- ely that such waste, as well as blowdown, will be stored in large ponds from which the water will evaporate. The solids would be stored in the ponds or buried in the stripmine pits during reclamation. Although it is relatively easy to prevent surface outflow from storage ponds, seepage into the groundwater can be eliminated only by careful construc- tion of concrete or membrane linings. The cost would be substantial. Evidence to support a zero-seepage requirement is lacking at present. Colstrip Unit 1 will be intensively monitored to detect undesirable seepage from storage ponds. If seepage threatens to contaminate the groundwater, remedial measures can be required by the Montana DHES. Possible adverse effects of stack emissions from large coal-fired power plants in the northern Great Plains have yet to be monitored and quantified. The environmental impact statement on Colstrip Units 3 and 4 (Montana DNRC 1974) concluded that stack emissions probably would damage vegetation but that " ... acid production from sulfur dioxide emitted from Colstrip Units 1, 2, 3, and 4 would not create significant pH changes in nearby streams ... " and that, with respect to lead, mercury, and fluoride, " ... there appears to be no reason to assume that adverse concentrations of these elements will occur in streams of the area." The cumulative effect of numerous power plants the size of the Colstrip units and synthetic fuel facilities may not be negligible, however. Trace ele- ments from many coal-conversion installations could lead to the accumulation of toxic materials in the watershed and adversely affect water quality, particularly 69 in lakes and reservoirs. As with pollutants from ashes, blowdown, and overbur- den, the logical approach is to systematically monitor affected waters near existing installations in order to detect significant changes in important trace elements before concentrations reach unacceptable levels. Such information also will provide data that can be used to predict the effects of future projects on water quality. SYNTHETIC FUEL PLANTS Basically, the conversion of coal into oil or gas consists of adding hydro- gen to coal. Water (as steam) is the source of hydrogen. Every conversion pro- cess, of which there are several (Mudge et al. 1974, Battella 1974, Chopey 1974, Probstein et al. 1974), must involve a gasification step in which coal reacts with steam to produce a synthesis gas that can be modified with more steam to obtain more of the hydrogen needed to convert coal into oil and hydrocarbon gas (Cochran 1976). In addition to· processing, water is used for cooling, generating steam energy, ash handling, sanitary purposes, and flushing of the cooling system. Water requirements are expected to range from 5,000 to 10,000 af/y for a 250 million standard cubic-foot-per-day gasification plant (Thomas 1975) up to 29,000 af/y for a 100,000-barrel-per-day synthetic crude oil facility (Dickinson 1974). The synthetic crude plant would consume 18 million tons of coal per year; the gasification plant, 7.6 million. A coal conversion complex could produce a combination of pipeline quality gas, synthetic, crude oil, low-sulfur fuel oils, solid char, solvent refined coal, and various byproducts. Water requirements of a specific facility would depend on many factors, including the processes used in converting coal to other products, the mix of oils and gas produced, moisture content of the raw coal, degree of water recycling, and type of cooling system used. Synthetic fuel facilities ideally will recycle all water until it is con- sumed (Beychok 1975, SERNCO 1974, USDI 1974). Thus, there should be no waste- water discharge. Rubin and McMichael (1975), however, believe that it "is often technically or economically infeasible to recycle all wastewaters consumptively." Table 21 identifies the quantity and nature of major wastewater streams within a 270 million standard cubic-foot-per-day gasification plant proposed for Wyoming (SERNCO 1974). Because of water's great solvent ability, the composition of process waters will be complex and contain small amounts of practically all com- pounds in the coal, in addition to the contaminants shown in table 21. Lique- faction processes will produce wastes of similar quality._ Such wastewaters could not be discharged to Montana streams under existing statutes and rules. Therefore, water not evaporated or incorporated into fuel products will accompany solid wastes and brines leaving the plant. The liquid portion will eventually evaporate or seep into the ground. The remaining solid material--ashes, sludges, and other wastes--will be permanently stored in sealed ponds or buried. The pollution potential of these wastes is similar to that of power plant wastes. 70 .. t TABLE 21. Quantity and nature of major wastewater streams from 270 x 10 6 SCF/day plant proposed for Wyoming. Source Major phenosolvan effluent Minor phenosolvan effluent Oily sewer Sanitary waste Storm and fire Selected blowdowns SOURCE: SERNCO (lg74). aGallons per minute. Design Quantity gpma z,g47 1 ,097 180 lg 67 327 Nature Rich in NH3, H2S, and low- boiling organics Rich in high-boiling organics, fatty acids, ammonia, coal dust, and total dissolved solids Oily with suspended solids Like municipal sewage Oily with suspended solids Clean with moderate total dis- solved solids CONTROL OF WASTEWATERS FROM COAL-CONVERSION FACILITIES The conversion of coal into electricity, substitute natural gas, synthetic crude oil, and other gaseous and liquid products results in a variety of pol- lutants detrimental to water quality. Potential problem areas are: (1) heat from cooling devices, (2) blowdown, (3) process wastewaters, and (4) solid waste. Methods of controlling these wastes to prevent water pollution are des- cribed below. Heat From Cooling Devices Approximately two-thirds of the energy content of coal is rejected to the environment in a coal-fired power plant; a synthetic fuel plant rejects approx- imately one-third. This lost energy is ultimately transferred to the atmosphere, directly or through evaporation of cooling water. Under current Montana regu- lations, little heated water could be discharged into a stream. Therefore, closed-cycle wet cooling devices; e.g., cooling ponds or evaporative towers, dry (air-cooled) towers, or hybrid (wet-dry) devices would be required for energy conversion facilities in Montana. Consequently, no direct thermal addition to streams should occur. 71 l \:. I ;-- Slowdown The following methods have been used to handle blowdown from large cooling towers (Boice et al. 1973): (1) discharge directly to receiving waters, ( 2) treatment and discharge, and ( 3) evaporation or treatment for reuse (zero- discharge). The quality of blowdown can be controlled somewhat through the use of cor- rosion resistant pipes, pretreatment of recirculating water, the use of physical (brushes or balls to mechanically scrape the interior of pipes) rather than chemical means to remove scale, and other methods. It is highly unlikely that any blowdown, however, could be legally discharged directly into Montana streams. Consequently, treatment of blowdown before discharge or complete use (zero- discharge) are more probable solutions. Treatment would have to remove suspended sediment, chlorine residual, and any other objectionable constituent, and cool the blowdown to approximately the temperature of the receiving streams. Settling ponds can achieve much of the required treatment, but the effluent still may contain traces of pollutants. Therefore, to avoid expensive additional treatment and in order to utilize water fully in semiarid areas, it is probable that blowdown ultimately will' be stored in ponds, perhaps with ashes and sludges, where the water will evaporate, leav- ing only a solid residue to be handled. The blowdown could be recycled several times or combined with other waste streams or cooling water before final storage. Process Wastewaters Characteristics of wastewater streams in a gasification plant are given in table 21. Rubin and McMichael (1975) list similar waste for other coal conver- sion processes and state that '' ... coal process waters have an inorganic com- position as saline as seawater with the addition of small amounts of practically all the organic compounds found in coal." Since there are more than two dozen technically feasible gasification systems and more than a dozen liquefaction processes, the mix of pollutants in wastewater streams from a synthetic fuel p 1 ant depends upon the process emp 1 oyed, as well as the composition of the co a 1 and the quality of the raw water supply. Effluent standards for synthetic fuel plants have not been established be- cause no commercial plants are operating in the United States. In view of the goal of no discharge of pollutants by 1985, the need for water conservation in semiarid regions, and the difficulty of treating wastewaters from coal conver- siurr facilities, it is probable that energy plants-proposed for Montana will have no discharge of effluent wastewater. Water not evaporated or converted to fuel ultimately will be buried with wet ash and sludge in the strip mine pits or stored in ponds. Ramifications of subsurface disposal of such wastes are discussed in the section entitled "Impacts of Water Withdrawals." Solid Waste Solid waste from coal conversion processes consists of bottom ash from the boiler, fly ash, ash from gasifiers, refuse from coal preparation, sludges from 72 f I ~ I , scrubber systems, sludges from water treatment, organic waste from domestic sewage, and dissolved and suspended solids contained in the various wastewater streams that transport or are combined with the ashes and sludges. Solid waste production, including the moisture contained in the material, will range from less than 1,000 tons per day from a 1,000 MW power plant up to 3,500-6,000 tons per day from a 250 MM SCFD gasification complex (SERNCO 1974, Beychak 1975). Liquefaction wastes should be comparable to those from gasification. The fol- lowing methods can be used to handle these solid wastes: 1) burial of coarse wastes (principally ashes) in strip mine pits under six to ten feet of overburden; and 2) storage of fine materials in storage ponds which would be buried permanently after completion of the project, or periodic removal and burial of the solids in the pits. There is legitimate concern that seepage from ponds or infiltration of water through the buried wastes will contaminate the groundwater reservoir. Although according to Persse (1975), "To date, there is no evidence to substantiate this concept," table 22 indicates that the wastewaters from the power plant at Col- strip contain trace elements which could adversely affect groundwater quality. Consequently, it would be advisable to permanently isolate these wastes from the groundwater. Isolation could be accomplished by burial above the.water table, on top of an impervious layer of clay or other lining, and under several feet of overburden. Only additional field monitoring can determine if the threat to groundwater quality is sufficient to justify the extra cost of pro- viding permanent segregation where natural geologic formations fail to do so. The EPA (1976) points out that permanent storage of solid and initially liquid wastes in holding ponds is not without peril. Effluents are concen- trated substantially during storage. Accidental release, perhaps as a result of earthquakes, flash floods, or structural failure, would produce acute ef- fects, as opposed to chronic effects of a small continuous discharge. The fate of storage sites after termination of the project requires attention also. Perhaps imbankments and impermeable membranes can be maintained during the active life of an energy-conversion facility, but there remains the question of who will be responsible for them when the plant is abandoned after producing 3D to 40 years' volume of wastes. MUNICIPAL AND INDUSTRIAL WASTES MUNICIPAL WASTEWATER Increased mining and transportation of coal and the construction and oper- ation of coal-conversion complexes and other facilities related to mining will initiate an influx of people into eastern Montana. This increase -in population will burden the region with additional domestic waste. The chief pollutants in domestic wastewater are pathogens, organic matter, and nutrients. The organic material--dissolved, suspended, and settleable--can become foodstuff for the · complex interdependent system of plant and animal life in receiving waters. If sufficient oxygen is present, the end products will be stable forms of carbon, nitrogen, sulfur, and phosphorus. TABLE 22. Physical parameters of waters from ArmellS Creek and Montana Power Company ponds in and near Colstrip. Source of Water Dead Cooling Cooling East Fork East Fork Flyash Bottom Bottom Storage· Tower Tower Fishing Anrells Creek Anne 11 s Creek Pond A Ash Pond Ash Pond Pond B Slowdown Slowdown Pond above Colstrip below Col !.trip 2/10/76 2/10/76 5/13/76 5/13/76 2/10/76 5/13/76 2/10/76 2/10/76 2/10/76 Temp 0.0 0.0 0.0 6.5 pit 4.6 10.22 9. 79 8.09 7. 77 8.37 7.96 7.79 7. 72 sc 7007 2813 3806 3494 4605 3214 4464 2985 2508 TDS 7337 2375 4080 4315 2784 1988 Turb 14 21 105 32 11 44 Ttl 5596 1306 1822 2802 1764 1090 TA 2 43 102 355 448 307 N03-N 10.3 1.5 2.8 .06 .38 . 15 POfP .015 .002 1.32 .015 .054 I. 62 SA 0. 5 2.5 5.1 2.0 1.6 2. 2 Ca 494 449 433 162 217 150 M9 1060 4S 180 582 297 174 II a 91 210 S44 240 150 165 K 6.2 5.8 34 22 12 22 Co .10 .03 .02 .04 <.01 <.01 rli . 37 .08 .06 .06 .01 <.01 s;o2 200 .so 83 2. 2 12 25 Cd .025 .005 .007 .007 .005 .003 Ba .20 . 10 . 30 <.10 .I 0 .10 v .65 <. 10 0.1 <.1 <. 1 < .1 AI 17 .65 2.3 .70 .15 1.4 Sn <.50 <.50 .50 <.SO <.50 <.SO Hg .0076 .0018 .0002 .0014 <.0002 <.0002 Cr .07 .01 .05 .01 .01 .01 011 1.2 Se . 18 .051 .018 .008 .007 .009 .001 .007 As .001 .004 .035 .004 .004 .004 Li . 35 .07 .09 .03 .02 .OS 11:103 2 0! i 124 433 547 37S C03 0 23 0 0 0 0 Cl 15.8 18.8 78 25 0.7 61 so4 S650 1620 2720 28SO 1560 1040 Fe .63 .11 1.7 .45 .56 2.2 Mn 5.5 .02 . 13 .35 1.2 .89 Zn .23 .56 <.01 "<. 01 .56 <.01 <.01 .27 .03 Cn . 24 . 01 .02 .03 1.1 .06 .02 .01 .04 B 32 24.8 . 74 .50 .27 .50 Pb . 12 .05 .08 .07 .05 <.05 Sr 6.9 5.0 B. 4 4.8 9.3 8.5 F 8.4 .46 2.6 . 15 .22 1.2 Sb .64 . 10 .10 . 10 <.01 <.01 Ag <.01 <.01 <.01 .01 <.01 <.01 Be .01 <.01 <.01 <.01 <.01 <.01 Mo <.05 <.05 <.05 <.05 <.05 <.05 tlOTE: All measurements expressed 'in mg/1 . .... In the absence of oxygen, on the other hand, decomposition will be accom- panied by unsightly scum, sludge, and offensive odors. Since natural streams contain a limited quantity of dissolved oxygen (about 5-12 mg/1) and untreated domestic wastes usually require 200 mg/1 or more of oxygen for decomposition, a large dilution factor or extensive treatment before discharge is required to prevent depletion of a stream's oxygen supply and the resultant destruction of fish. The goal of modern treatment processes is to provide a favorable environ- ment for the growth of organisms which will perform most of the decomposition before the wastewater is discharged to the receiving waters. Even with normal (secondary) treatment, however, the effluent will contain nutrients, principally compounds of nitrogen and phosphorus, which can over- fertilize plants in the water and cause unsightly algae blooms. Unchecked, the result is premature aging of lakes and streams--a process called eutrophi- cation. It brings changes in water quality, depletion of oxygen, and replace- ment of desirable fish species with less desirable species. If eutrophication is a serious threat, advanced treatment processes may be required to remove the nutrients from wastewater. Karp and Botz (1975) and Karp et al. (1975, 1976) have described thoroughly the 46 existing wastewater treatment facilities in the Yellowstone Basin. The low population density, availability of land, and the minimal maintenance re- quirement have made lagoons the favored type of domestic wastewater treatment facility. Most towns use multicell lagoon systems to treat their domestic waste- water, although Billings has a complete mix activated sludge system and Living- ston and Laurel have primary treatment plants. All towns that discharge from their treatment systems are under the Montana Pollutant Discharge Elimination System (MPDES) permit program that placed them on a compliance schedule to meet requirements of federal laws for secondary treatment by July 1, 1977. However, the degradation of streams by municipal wastewater discharges is decreasing as communities upgrade their treatment processes (Karp et al. 1g75). The 208 plans will identify treatment systems that may require upgrading and expansion as a result of anticipated population increases. Localized problems may occur where: (1) population increases are.so rapid that existing facilities become overloaded before the community can expand its treatment facilities, or (2) domestic waste from individual or clustered dwel- lings (such as mobile home courts in unincorporated "areas) may, because of overloaded or improperly designed treatment systems, reach a watercourse. Septic tank effluents also may have a significant impact on groundwater sys- tems. Soil has a natural renovative capacity for septic tank effluent, but where the density of septic tanks is high, this capacity may be exceeded, pol- luting the groundwater system. Advance planning and strict enforcement of existing zoning and sanitation laws can minimize these problems. INDUSTRIAL WASTEWATER Karp and Botz (197~ and Karp et al. {1976) identified 25 industrial dis- chargers in the basin, including three oil refineries, two coal-fired power plants, two sugar refineries, and several miscellaneous industries such as meat packing plants, oil well fields, and coal mines. All are under the MPDES permit 75 program and are following schedules to comply with requirements of the 1972 Federal Water Pollution Control Act Amendments (FWPCAA), which call for use of the "best practical control technology" by 1977, "best available control techno 1 ogy" by l g83, and "no discharge of pollutants" by 1985. At present, industrial wastewaters are a decreasing or stable problem. Water quality in the Laurel-Billings reach of the river, which receives wastes from three oil refineries, one steam generating plant, two municipal waste- water treatment plants, two water treatment plants, a sugar beet factory, two meat packing plants (that pretreat wastewaters before discharging to the Bil- lings wastewater treatment plant), and several storm drains, has improved markedly in recent years as modern pollution control techniques have been adopted by industries and by the City of Billings (Klarich 1976). Improvement should continue in the future as industries further reduce their waste discharges in response to deadlines established by the 1972 FWPCAA. Problems of new coal- energy industries are described in previous sections. CONTROL OF MUNiCIPAL AND INDUSTRIAL WASTEWATERS Under existing federal law all publically owned treatment works must have employed the equivalent of secondary treatment by July l, 1977, best practicable waste treatment technology by 1983, and eliminate discharges of waste by 1985. Karp et al. (1975, 1976) and Karp and Botz (1975) reviewed the performance of all community-owned treatment works in the basin and concluded that: (l) the degradation of streams by municipal wastewater is decreasing as treatment pro- cesses are upgraded, and (2) the potential for correction of problem areas is good; the principal need is for additional federal grant funding. Several techniques are available to upgrade the effectiveness of the la- goons serving the majority of communities in the basin. Methods include: 1) construction of sufficient capacity so that no discharge occurs and all influent evaporates; 2) mechanical aeration to add oxygen to a system; 3) use of rock or intermittent sand filters to "polish" the effluent; 4) application of effluent to land; 5) addition of chemicals to aid in treatment; and 6) biological harvesting to control effluent solids and nutrients. Further descriptions of these and other methods are given by Lewis and Smith (1973) and Middlebrooks et al. (1974). Thus, municipalities in the basin should be able to achieve secondary treatment as grant funds become available. Industries, like municipalities, are under schedules established by the 1972 FWPCAA to reduce and eventually eliminate discharges of pollutants into state waters. Substantial progress has been made through combinations of the following practices: 76 I m 1) modification of industrial processes to reduce the volume and nature of wastewaters; e.g., recycling and inline treatment; 2) installation of more refined treatment processes to reduce pollutants in the effluent; and 3) rerouting of industrial wastewaters, perhaps after pretreat- ment, into municipal treatment systems. The Yellowstone River's water quality has improved significantly in recent years as municipalities and industries have adopted better methods of handling waste- waters. IRRIGATION RETURN FLOW Salt is a product of geologic weathering. Precipitation and drainage trans- port salt into streams and rivers and maintain the quantity of dissolved minerals in the soil at levels which allow plant growth. Thus, through the ages, salt from the watershed has been carried to the ocean by rivers. In changing from natural vegetation to irrigated croplands, dissolved salts as well as water are diverted to the land. If the salt is not removed the land eventually will be- come too saline for continued agriculture. Therefore, sound agricultural prac- tices dictate that a salt balance be maintained: all salt in the diverted water must be returned to the stream. Since the river will have less water (some having been consumed by evapotranspiration), the concentration of salt will be increased downstream of the irrigated area. Where excess water is applied to the land or the soils contain excessive soluble salts, irrigation return flows may dissolve additional salt and carry it into the stream, thereby forcing the river to carry more salt with less water. Each successive diversion and irri- gation cycle on a stream further increases the salt concentration. Irrigation return flows also may deteriorate in quality through the presence of fertilizers, pesticides, and suspended solids acquired during the irrigation cycle. The effects of irrigation return flows on water quality have been well- studied in many parts of the western United States (Utah State University Foun- dation 1969, Scofield 1936, Pillsbury and Bloney 1966, Sylvester and Seabloom 1963, Eldridge 1960). Generally, research was directed at areas with the greatest water quality problems, such as Imperial Valley, California and the Colorado River Basin. Regions endowed with abundant high water quality, such as the Yellowstone River, have received little attention from researchers; consequently, possible effects of irrigation on water quality in the Yellow- stone River have not been documented. The United States Bureau of Reclamation (USSR) has completed some unpublished studies on irrigation return flow in the Wyoming portion of the basin (Madsen 1975). Another USSR project has collected extensive data on quantity and quality of diversions and return flows in the Yellowstone Basin in both Wyoming and Montana, but final results are not yet available (Manfredi 1976). The state WQB (1975) has collected and analyzed water quality samples from miscellaneous irrigation return flows in the Yel- lowstone Valley below Billings. Data from the USSR projects and the state WQB indicate that salt concentra- tion in the irrigation return flow may be several times higher than that of the applied water. The USSR data, for example, revealed concentration factors (salt 77 concentration in irrigation return flow divided by salt concentration in ap- plied water) ranging from 1.8 to 3.1 (Manfredi 1976) in surface return flows. Returns identified as subsurface concentrated salts by a factor of 4.9. These concentration factors result from two processes: (1) the extrac- tion of essentially pure (nearly distilled) water by plants in their growth processes, which concentrates the dissolved salts in the water remaining in the soil, and (2) the leaching of additional salts ("salt pickup") by water as it percolates through the soil. By measuring the volumes and TDS of di- versions and return flows on an irrigated area, it is possible to compute the salt pickup. Data from Madsen (1975) indicate that salt pickup ranged from 0.84 to 8. 73 tons per acre per year in several USBR projects in Wyoming. In- complete data from Manfredi (1976) reveal gross estimates of less than 0 (in- dicating that salt is accumulating in the soil) up to one-half ton per acre per year salt pickup in various portions of the Yellowstone Basin in Montana. These estimates are somewhat low because: (1) most measurements were made on surface return flows which have less opportunity to leach salts from the soil profile than subsurface return flows, and (2) measurements were terminated in early fall, whereas subsurface returns may continue for several months after irrigation and surface returns cease. Gross estimates of salt pickup between Billings and Sidney can be obtained from table 23, which summarizes water and TDS discharges of the Yellowstone River and major tributaries. For example, if the contributions from the Big- horn, Tongue, and Powder rivers are subtracted, table 23 reveals that the area along the mainstem of the Yellowstone between Billings and Sidney contributed 892,986 tons of salt and 228,010 net acre-feet of water to the river. These TABLE 23. Summary of salt and water discharges in the Yellowstone River Basin, 1944-1973. Station Water Discharge Total Dissolved Solids (acre-feet) (Tons) (mg/1) Yellowstone River & Billings 5,276,494 1 ,306,038 182 Bighorn River near Bighorn 2,596,214 2,076,140 588 Yellowstone River near Miles City . 8,240,640 4,16g,lo5 372 Tongue River at Miles City 289,151 178,533 454 Powder River near Locate 335,067 518,121 1 • 137 Yellowstone River near .Sidney 8,724,936 4,971,818 419 NOTE: Values were measured or simulated based upon relationships developed from measured data. data suggest that the additional inflow (228,010) contained an average of 3.92 tons per acre-foot, or 2,880 mg/1. However, records of streams in eastern Montana indicate that the TDS of surface runoff is about 1,200-1,300 mg/1. Therefore, surface runoff could account for only 40 percent to 50 percent of the salt increase. Assuming that 45 percent of the 892,986 tons result from surface runoff, 491,142 tons can be attributed to other sources: groundwater 7fl discharge, seeps, springs, and irrigation return flows. If all of it were at- tributed to the 291,985 acres of irrigated land along the mainstem of the Yel- lowstone, salt pickup would be 2.12 tons per acre. Such a gross estimate, however, is somewhat misleading. Table 23 shows that most of the increase in salt load occurs between Billings and Miles City. Between Miles City and Sidney (adjusting for the higher salt loads contributed by the Tongue and Powder rivers), the Yellowstone gains only 106,000 tons of salt per year, but loses 140,000 acre-feet of water. Therefore, salt pickup cannot be estimated for the Miles City-to-Sidney reach. One can conclude only that: (1) the salt load generally increases between Billings and Sidney, (2) irrigation along the mainstem of the Yellowstone contributes an average salt pickup of no more than two tons per acre per year, and (3) the salt pick- up varies between different parts of the basin; some irrigated lands may con- tribute several tons per acre and others may remove salt and store it in the soil. Irrigation may also change the concentration of suspended solids, depending upon TSS levels in the applied water, the method of applying the water, type of soil, tillage methods, slope, type of drainage system, and similar factors. Preliminary data from Manfredi (1976) indicate that TSS may be increased or de-. creased by the irrigation cycle. In some reaches of the Yellowstone, TSS of surface return flow increased by a factor ranging from 1.1 to 4.9; in other reaches or tributaries, TSS was actually lower in the surface return flow than in the applied water. In subsurface returns, TSS should be low because of the filtering action of the soil. Subsurface drainage in the lower Yellowstone Basin averaged only 6 mg/1 TSS and 254 mg/1 in the applied water. If it is assumed that new irrigation systems will be more efficient than existing systems, surface return flow should be minimal. Most return flow will reach the stream by deep percolation through the soil. ·Consequently, such re- turn flows should be characterized by low concentrations of TSS but high con- centrations of TDS. Sprinkler irrigation on slopes, however, could have tne opposite effect--significant surface return flows high in TSS and little sub- surface return flow. CONTROL OF WASTEWATER FROM IRRIGATION The principal method employed to reduce salt pickup is to reduce the vol- ume of subsurface return flows. Seepage losses can be reduced by lining canals and laterals. Deep percolation losses can be reduced by improved irrigation methods that minimize over-irrigation and uneven applications of water. Tile drainage can be installed immediately below the root zone, thus intercepting percolating waters before they have the opportunity to seep through subsurface soils and dissolve additional salts. Highly mineralized return flows can be conveyed to evaporation ponds. Similarly, silt-laden return flows could be stored temporarily in a sediment basin to allow some of the silt to settle out before the water is discharged. In an extreme case, irrigation return flows could be treated with coagulants in holding ponds to remove suspended solids or by desalinization facilities to reduce TDS. Treatment is expensive, however, and is not usually practical. The practices most likely to reduce the adverse 79 effects of irrigation return flows in the Yellowstone Basin are those involving better water management: lining of ditches, land leveling, converting to sprink- ler irrigation, avoiding the over-application of water, and monitoring of soil moisture. · NONPOINT SOURCES OF POLLUTION The Montana DHES discussed problems of nonpoint pollution in the Yellow- stone River Basin in its Water Quality Inventory and Management Plans (Karp and Botz 1975, Karp et al. 1975, 1976). Agriculture, runoff from urban areas, con- struction projects, inadvertent spills, and natural phenomena were identified as activities which contribute nonpoint pollution (table 24). TABLE 24. Nonpoint waste sources and characteristics in the Yellowstone River Basin. Activity Waste Characteristics Irrigation return flows Runoff from pasture lands Runoff from saline seep areas ·Runoff from cultivated land Storm drains and urban runoff Construction projects, streambank riprapping Coal mining Dissolved and suspended solids, pesti- cides, nutrients, heat Animal wastes, sediment Salts, sediment Fertilizers, pesticides, dissolved salts, sediment Oil and grease, coliforms, biological oxidizable material, suspended solids, toxicants Sediment, equipment wastes Dissolved and suspended solids, trace elements, equipment waste SOURCE: Karp and Botz ( 1975), Karp et a 1. ( 1975, 1976). According to the ,Montana DHES, agricultural nonpoint discharge is the most serious problem in the basin, followed by storm drains and urban runoff, con- struction projects, accidental discharges, and natural nonpoint sources. Agri- cultural runoff and runoff from saline seep areas are the most significant pro- blems in the lower portion of the basin, particularly below Glendive. Unfortunately, available data are not sufficient to quantify nonpoint pol- lution from the individual sources. The cumulative effect, however, is reflected in the gradual deterioration in water quality between Corwin Springs and Cart- wright, North Dakota. Several recent and on-going projects will provide further 80 information on the nature and magnitude of nonpoint pollution problems in Montana. Kaiser et al. (1975), jn the first comprehensive report on saline seep in Montana, listed 28,000 acres in the Yellowstone Basin affected by saline seep and 24,700 additional acres with irrigation salinity problems. One of their conclusions was that "some current land uses are creating sal- inity problems, and, if left unaltered, will pose economic and environmental problems to future generations." The environmental problems include salini- zation of groundwater and streams. · Another report by the state WQB (Karp et al., in preparation) identifies and quantifies nonpoint sources in the Billings area. In addition, the 208 planning efforts by the mid-Yellowstone and Yellowstone-Tongue area planning organizations (APO's) and by the state WQB on areas not covered by the regional APO's are including nonpoint pollution as a major study item. CONTROL OF POLLUTION FRON NONPOINT SOURCES Water pollution from nonpoint sources can be controlled by the use of ap- propriate management practices. Some sections in this report describe tech- niques applicable to irrigation return flows and surface mining of coal--two major sources of nonpoint pollution. According to the EPA (1973}, goals of reducing water pollution from agricultural land may be achieved by containing erosion at the source by means of effective conservation practice·s applied to the land, and by applying fertilizers and pesticides in appropriate amounts at the proper times and in the proper places. Methods used to control wastes from livestock are described by Manges et al. (1975) and Horton et al. (1976). More difficult to control than livestock wastes will be the management of polluted runoff from urban areas--"runoff generated by precipitation which washes and cleanses an urban environment, and then transports the dirt, filth, etc. to the nearest natural or man-made water- course" (Colston 1974). Urban runoff can be: (1) treated in municipal waste- water treatment plants (but a high volume of runoff during a short time inter- val may overload treatment facilities and result fn ineffectual treatment), or (2) stored temporarily in retention basins before being released to a stream or to wastewater treatment facilities. Both methods are relatively expensive and not entirely satisfactory. It is hoped that the 208 plans will identify nonpoint pollution problems in the Yellowstone River Basin and recommend feasible control techniques. SLURRY PIPELINES Slurry pipelines would transport a mixture of approximately one-half fine coal and one-half water, by weight. An economically sized facility would re- quire 7,500 acre-feet to transport ten million tons of coal per year. The initial terminal would require storage facilities for large volumes of both coal and water. Water storage should present no pollution problem. If treat- ment of the water is required, various chemicals, solids, and sludges may have to be handled. Water may leach through coal piles and contribute suspended and 81 dissolved contaminants to local water supplies. One remedy involves storing the coal on impermeable sites with a settling basin downstream to collect surface runoff. Currently, the export of coal via slurry pipelines is not a beneficial use under Montana water law. 82 YELLOWSTONE RIVER MAINSTEM ABOVE THE MOUTH OF THE CLARKS FORK YELLOWSTONE RIVER The Yellowstone River drainage above the confluence of the Clarks Fork River has been defined as the secondary study area, and only the mainstem of the region has been inventoried in this survey. Water quality data are avail- able from the USGS, which has maintained three monitoring stations on this reach of the stream; however, these data are not extensive, particularly for certain parameters, because the USGS stations have been in operation for only a short period of tine (table 2). Supplemental data, collected as a part of water quality runs on the mainstem (Peterman and Knudson 1975) and from other programs (Karp et al. l976a) are available from the state WQB for several lo- cations on this segment of the river (table 4). Data from the two agencies were combined for this inventory to provide information for four stations or reaches of the Yellowstone from Corwin Springs to Laurel, 1·1ontana: at Corwin Springs, near Livingston, between Big Timber and Columbus, and at Laurel (above the Clarks Fork), in downstream order. Statistical summaries of the major parameters are included in tables 25-28 for these locations. In some cases, data obtained by the state WQB from closely related sites were combined in order to expand the data base. Thurston et al. (1975) also present some water quality information for the upper Yellowstone, but ~hese data were not reviewed for the current survey. As indicated in table 25, the Yellowstone River at Corwin Springs has a sodium-bicarbonate water through most seasons. The waters are generally soft and would be classified as ideal for municipal supply (Bean 1972). The ionic composition is probably a reflection of the river's proximity to its mountain- ous headwaters. Yello~1stone National Park streams are often quite sadie (Klarich and Wright 1974, Rasmussen 1968, USEPA 1972, Wright and Mills no date) as a result of the park's thermal discharges that flo~1 over rhyolite bedrock composed of sodium feldspars; calcium-containing rocks are relatively rare (Boyd 1961, Roeder 1966). The sadie nature of the Yellowstone at Corwin Springs is most distinct during low-flow periods when a large portion of the discharge in the river below Gardiner (north park entrance) is due to the in- flow from Yellowstone Park with reduced flows in Montana's tributary streams. The high concentrations of fluoride and phosphorus in the river at Corwin Springs and the purported arsenic problem of the upper Yellowstone River (Montana DHES 1975, 11ontana DHES 1976) are also probably related to influences originating within Yellowstone Park, e.g., from geyser activity. During the spring high-flow period of the Yell01~stone at Corwin Springs, the waters have a higher ratio of calcium to sodium than at other seasons (table 25), probably related to the greater flows and increased influence of the tributary streams at this time. Yellowstone tributaries in Montana are largely calcium bicarbonate above the confluence of the Clarks Fork River (Karp et al. 1976). The effects of these tributary streams, e.g., the Shields, Boulder, and Stillwater rivers ~1hich drain the Crazy, Absaroka, and Beartooth mountains, are also evident in the mainstem in a downstream direction below Corwin Springs through the increased flows of the river; in addition, calcium 83 TABLE 25. Summary of the physical parameters measured in the Yellowstone River at Corwin Springs. August-October November-February March-Apri 1 May-July N ~1ln r~ax Med II Min Max fled N Min Max /·led II Min Max Med Flow 13 1320 4910 1920 12 854 3650 1045 6 978 1560 1095 12 3610 22,400 8190 Temp 11 5.5 17.2 8.0 12 0.0 5.0 1.8 6 4.5 9.0 7.3 12 4.5 17.0 10.8 pH 12 6.8 8.6 7.85 12 7.0 8. 2 7. 75 6 6.9 B. 7 8.4 12 6.1 R.O 7.5 sc 14 154 255 220 12 230 300 280 6 240 300 283 13 80 .161 130 TOS 13 lOB 178 151 12 156 218 190 6 93 220 186 12 60 130 86 Turb 4 1.0 3.8 3.2 5 2.0 5 3.0 2 4.0 6.0 5.0 6 8.0 50 11 TSS 1 ----9.4 1 ----2.0 0 ------3 17 4R. 5 38.9 00 12 8.4 11.8 10.1 12 10.6 13.2 12.0 6 10.7 12.2 11.4 12 8.1 11 9.7 BOO 11 0.6 1.6 1.0 12 0.6 3.0 1.4 6 0.9 1.5 1.2 12 0.6 2.6 1.1 FC 7 4 88 30 7 0 42 11 4 2 7 5 8 2 30 <10 Ca TO 12 18 15 8 15 23 18 4 17 20 19 9 7. g 20 TO Mg TO 3.4 6.0 5.0 8 4.7 7. 1 5.6 4 5.8 6.4 6.1 g 1.2 3.9 2. g TH 13 46 68 58 12 58 87 73 6 66 76 73 12 28 44 35 Na 10 12 22 19 8 13 28 24 4 15 26 23 9 6.0 14 TO K 1 ----2.5 1 ----5.5 0 ------2 1.6 2.5 2.1 SAR 2 0.7 1.1 0.9 1 ----1.5 0 ------3 0.5 0.6 0.5 HC0 3 2 59 70 65 1 ----79 0 ------3 43 72 61 TA 11 47 114 58 10 59 83 72 4 68 72 71 10 17 59 39 504 13 17 36 30 12 30 48 40 6 32 46 36 12 7.5 60 12 C1 10 6.5 11 9.8 8 9. 9 18 13 4 12 14 13 g 2.1 7.0 4.0 F 9 0.5 0.9 0.8 8 0.9 1.1 1.0 4 0. 7 1.1 1.0 g 0.3 0.6 0. 4 N 9 0.02 0.20 0.09 9 0.18 0.40 0.27 5 0.10 0.30 0.20 TO 0.03 1.9 0.08 p 10 0.01 0.12 0.06 8 0.02 0.39 0.07 5 0.03 0.08 0.06 g 0.03 0.48 0.07 NOTE: Measurements given in mg/1. co '-" TABLE 26. Summary of the physical parameters measured in the Yellowstone River near livingston. August-October November-February March-April N ,.lin t·lax Med N r~in ,.\ax Med N Min Max Flow 32 1920 6190 3020 36 961 2350 1525 20 1240 2950 Temp 6 5.0 15.3 7.0 5 0.0 3.5 1.5 5 6.5 ll.O pH 24 7.2 8. 3 7.85 32 7.3 8.5 7.9 18 7.4 8.6 sc 29 160 273 213 32 232 334 284 18 219 329 TDS 29 105 189 145 32 154 216 185 18 143 205 Turb l ----2.6 l ----2 0 ---- TSS l ----9.7 l ----2.0 0 ---- DO 3 8.5 11.9 10.0 l ----12.3 0 ---- BOD l ----1.30 l ----1.9 0 ---- FC l ----0 l ----7 0 ---- Ca 29 14 23 19 32 21 30 24 18 19 27 M9 33 4.0 8.2 5.6 32 5.9 8.9 7. 7 18 5.7 B. 5 Til 29 51 87 71 32 77 110 93 18 71 100 ria 29 II 21 16 32 17 25 20 18 15 24 K 27 2. I 5.3 3.3 32 3.6 6.7 5.0 18 3.6 6.4 SAR 29 0.6 l.O 0.8 32 0.8 l.O 0.9 18 0.8 1.1 HC0 3 29 70 116 94 32 98 131 110 18 83 120 TA 3 60 85 83 l ----83 0 ---- 504 29 10 3< 25 32 24 50 35 18 26 47 Cl 29 3. 8 8.8 7. l 32 7.6 14 II 18 6.6 12 F 27 0. 5 ·a. 8 0.6 32 0. 7 1.3 0.8 18 0.5 0. 9 r1 27 0.0 0.09 0.01 29 0.0 0. 39 0.13 18 0.0 0.13 p 15 0.0 0.19 0.05 17 0.0 0.15 0.03 8 0.01 0.08 rWTE: Measurements expressed in mg/1. -------.,------------------- May-July Med r1 Min Max Med 1630 44 1820 27,700 9090 8.5 10 4.5 17.0 13.0 7.9 39 6.4 8.2 7.6 278 42 93 272 141 181 42 68 176 92 --3 8.6 18 15 --3 26 83.8 66 --5 8.5 ll.O 10.0 --3 2.0 3.0 2.3 --3 5 80 10 23 42 9.2 24 12 7. 4 48 1.7 7. l 3. 8 87 42 33 89 48 21 42 4.9 18 8.6 5.0 39 1.2 6.3 2. l 0.9 42 0.3 0.8 0.5 107 42' 44 Ill 63 --5 53 41 63 35 42 5.8 34 12 ll 42 l.O ll 3.4 0.8 40 0.2 0.7 0.4 0.03 42 0.0 1.2 0.01 0.04 15 0.01 0.06 0.04 CX> "' TABLE 27. Sumnary of the physical parameters measured on miscellaneous sites on the Yellowstone River between Blg Timber and Columbus. AuguStaOctober November-February March-April Hay-July N Min Max fled N Min Max Med II Min Max Med N Min Max Med Flow 2 2870E 5460E 4165E 1 ----1760E llo data available 3 4990E 15,200E 7890E Temp 2 17.6 20.2 18.9 2 0.0 0.8 0.4 7 5.0 10.0 9. 1 pH 5 8.30 8.39 8.30 2 8.14 8.23 8.19 7 7.63 8.02 7.89 sc 5 189 292 278 2 320 345 333 7 1 31 281 201 TDS 5 150 219 207 2 246 267 257 7 112 232 166 Turb 2 2.1 3. 5 2.8 2 2 3 2.5 7 31 47 36 TSS 2 4.2 9.5 6.9 2 2 4 3.0 7 103 197 134 DO 5 9.0 11.2 10.1 2 12.4 12.9 12.7 7 9.7 10.9 10.0 BOD 2 1.0 1.1 1.1 2 2.6 2.9 2.8 7 1.7 4.1 3.1 FC 2 0 50 25 2 3 12 8 7 <10 150 50 Ca 5 19 29 27 2 32 35 34 7 16 39 27 Mg 5 5.1 9.6 7.3 2 7. 1 9.3 8.2 7 1.9 8.0 4.8 TH 5 69 108 98 2 108 125 117 7 56 115 91 II a 5 12 17 15 2 23 23 23 7 6.0 16 9.7 K 2 2.5 2.7 2.6 2 4.1 4.3 4.2 5 1.7 2.1 1.9 SAR 5 0.6 0. 7 0.6 2 0.9 1.0 1.0 7 0.3 0.6 0.4 HC0 3 5 91 129 115 2 126 143 135 7 70 143 104 TA 5 75 106 94 2 103 117 110 7 58 118 85 504 5 13 34 29 2 42 42 42 7 11 27 16 C1 5 5.3 6.9 5.7 2 9.9 11.6 10.8 7 1.0 3. 1 2.5 F 2 0.5 0. 5 0.5 2 0.6 0.8 0. 7 7 0.2 0.2 0.2 II 5 <.01 0.04 0.01 2 0.20 0.21 0.21 7 0.05 0. 78 0.23 p 5 0.01 0.04 0.02 2 0.01 0.02 0.02 7 0.03 0.22 0.04 NOTE: Measurements expressed in mg/1. TABLE 28. Sumnary of the physical parameters measured in the Yellowstone River at Laurel above the Clarks Fork Yellowstone River. August-October November-February March-April May-July N Nin Max Med fl Min Max Med fl Min Max Med N Min Max Med F'low 5 4030 713 5310 2 2500 3400£ 2950£ 5 2460 6500 3190 6 5510 50,900 16,150 Temp 6 14.5 20.8 15.3 3 0.1 4.5 1.0 5 1.5 13.5 8.0 9 6.5 19.5 14.5 pH 6 7.6 8.52 8.15 3 8.1 8.50 8.16 5 7.5 8.5 7. 9 9 7.4 8.6 7.8 -sc 7 204 315 245 3 324 410 342 5 238 337 310 9 115 443 170 TOS 6 128 199 151 3 206 309 247 5 128 201 183 9 60 291 123 Turb 5 1.3 4 3 2 5 5 5 5 3 70 30 9 2 100 30 TSS 5 1 16 12 2 a 9 a. 5 5 a 169 89 9 9 472 106 00 5 8.6 9.4 8.9 2 12.8 12.9 12.9 5 9.8 12.8 10.8 9 8.0 11.0 9.6 BOO 5 1.1 1.6 1.5 1 ----2.4 4 1.9 6.1 3.8 7 0.7 3.0 1.5 FC 5 3 86 50 2 2 10 6 5 0 57 30 8 0 660 24 Ca 2 18 21 20 3 32 39 33 2 32 32 32 5 12 37 26 Mq 2 5. 9 13 9.7 3 9.5 12 10 2 9.1 9.2 9.2 5 2.9 14 5.2 Til 2 77 100 89 3 118 147 120 2 120 120 120 5 42 ISO 83 Na 2 12 IS 14 3 21 26 22 2 19 21 20 5 5.1 13 11 K 1 ----2.3 2 3.8 3.9 3.9 2 3.5 4.0 3.8 4 1.7 2.3 2 .I SAR 2 0.6 0.6 0.6 3 0.8 0.9 0.9 2 0.8 0.8 0. 8 5 0.3 0.8 0.5 HC0 3 2 96 117 107 3 134 155 144 3 134 142 141 5 58 143 97 TA 2 81 97 39 3 115 127 118 2 116 117 117 5 48 117 85 504 2 15 29 22 2 43 63 53 3 35 42 39 5 7. 9 69 17 Cl 2 4.7 5.5 5.1 2 8.0 8.6 8.3 3 7 .I a. 7 7.8 5 1 .0 4.2 2.9 F 1 ----o·.4 1 ----0. 7 0 ---- -- 3 0.2 0.2 0.2 If 6 0.0 0.13 0.04 3 0.04 0.42 0.06 5 0.01 0.38 0.07 9 0.0 0.36 0.01 p 6 0.01 0.06 0.03 3 0.02 0.05 0.03 5 0.0 0.28 0.14 9 0.03 1.8 0.12 r:OTE: Measurements expre.ssed in mg/1. concentrations increase downstream while ·sodium levels in the river remain fairly constant from Corwin Springs to Laurel. As a result, the Yellowstone at Laurel is moderately hard with a calcium bicarbonate composition in all seasons (table 28}. A gradual decrease in fluoride and phosphorus concen- trations is also evident in the mainstem to Laurel due to a dilution by tri- butary streams which have relatively low concentrations of these constituents (Karp et al. 1976). Similarly, there is a small but consistent increase in magnesium levels downstream, accompanied by a decline in chloride concentra- tions from Corwin Springs to Laurel. This further suggests the gradual de- crease of Yellowstone National Park influences by progressive inputs of tri- butary water. However, in all segments of the river above the Clarks Fork River, magnesium, potassium, and chloride are minor constituents of the water, with sulfate being the secondary anion. A small downstream increase in median salinity of 10 percent to 45 percent, as expressed in terms of dissolved solids and specific conductance, is evident for the 158-mi 1 e segment of the upper Yellowstone between Corwin Springs and Laurel; however, this increase is not totally consistent between all sites or for all seasons. The increase in.salinity is greatest during the May-July period (between 30 percent and 45 percent}, lowest during the summer and spring (less than 15 percent), and intermediate durin·g the winter (between 20 percent and 30 percent). In addition, dissolved constituent concentrations in the upper river are definitely flow-related, with higher levels generally obtained during the 1 ow-flow periods-. The four sampling stations on the upper segment demonstrate a median difference in dissolved solids concentration between the May-July, high-flow period and the low flows of winter. However, none of the common ions have markedly high concentrations during any of the seasons or at any of the locations. Thus, the water in the upper Yellowstone River can be characterized as distinctively non-saline with maximum dissolved solid and specific conductance levels of 309 mg/1 and 443 vmhos/cm (at Laurel}; minimum values are 60 mg/1 and 80·vmhos at Corwin Springs. On the basis of salinity and the common ions, the waters in the upper reach appear to be suitable for application to all major beneficial uses, ·including agricultural, municipal supply, and aquatic life. As indicated in tables 15 and 16, SAR and specific conductance levels in water from the upper Yellowstone, along with the river's chloride, sulfate, and dissolved solids concentrations, indicate that the stream has a low salinity hazard and a low sodium or alkali hazard for irrigation. As a result, the Yellow- stone in this reach has a Class I water suitable for application to all crop and forage plants, including the salinity-intolerant species (table 17). These waters may also be classified as good in relation to livestock, as they are excellent for the watering of all farm and domestic animals (tables 10-14). Common con- stituent concentrations in the upper river were well below the threshold levels established by the California State Water Quality Control Board (Calif- ornia WQCB 1963}. Of the ionic constituents, only fluoride occasionally ex- ceeded the California WQCB threshold levels for stock in a few samples from the river at Corwin Springs. This·was generally not true at Livingston and further downstream due to the subsequent dilutions of fluoride by inputs from tributary streams. Even the occasionally high values of fluoride did not approach levels that would be limiting (a maximum of 1.3 mg/1 versus the 6.0 mg/1 standard), and fluoride concentrations in all samples were well below the criteria for livestock recommended by the EPA (USEPA 1973). As a result, 88 fluoride and dissolved solids concentrations of the upper river are \·tell with- in the prescribed limits for freshwater aquatic life. Fluorides in the Yello~tstone River above Laurel are below the recommended upper limits for human consumption and are well below concentrations that would constitute a rejection of public supply (table 9). Similarly, concentrations of dissolved solids and common constituents such as chloride and sulfate are considerably below the standards, criteria, and recommendations established by various agencies for drinking water and surface vtater, and municipal supply (USEPA 1973, USDI 1968, USDHE\~ 1962). In fact, the concentrations of these constituents and the soft water would make the river desirable as a water supply, according to the NTAC's recommendation (USDI 1968). The relatively high level of fluoride in the river at Corwin Springs is acfually within the optimum range (USDHE~J 1962) and may be advantageous in eliminating the need for accessory fluoridation. Thus, the occurrence of high fluorides in the upper Yellowstone, stemming from thermal activity in Yellowstone National Park, may not be as degrading to the river or to its beneficial use as has been suggested in other water quality surveys (Montana DHES 1975, Montana DHES 1976). Turbidity and total suspended sediment (TSS) levels in the upper Yellow- stone at Corwin Springs are low in comparison with other streams of the in- ventory area (table 25), even during the spring runoff period when the turbidity and TSS are highest (Karp and Botz 1975, Karp et al. 1975): This is also t7ue of the river near Livingston (table 26) although there is a slight downstn!!i~ increase in TSS between the t1·10 sites during high-flow periods. The low tur!. bidity and relatively uncolored waters (color ranging between one and four units) indicate that the extreme upper reach of the Yellowstone is aestheti- cally pleasing during a large part of the year. In turn, the low TSS and TDS concentrations and the low turbidity of the Corwin Springs-Livingston reach describe a ~tater potentially excellent for a freshwater fishery (Ell is 1944, European Inland Fisheries Advisory Commission 1965). Furthermore, the maximum temperatures of the Corwin Springs-Livingston reach (tables 25 and 26) and the temperatures recorded by the USGS for the stream at Livingston are typically below the critical maximum temperatures designated for B-D1 and B-D 2 class streams (table 8). For example, since 1970, only 9.7 percent of the once-daily temperature measurements at Livingston exceeded 19.5°C for the June-to-September, warm-weather period; 4.8 percent equalled or exceeded 20.0°C (USDI 1966-1974a). As a result, the upper Yellowstone fishery should be salmonid and cold-water, in accordance with the river's classification as a blue ribbon trout stream above Big Timber (Berg 1977). Turbidity and TSS concentrations are also low during periods of reduced flovt through the lower segment of the upper river (tables 27 and 28), but there is a distinct downstream increase in these para~eters during the spring and at high flows. This does not detract, however, from the value of the river as a water supply for municipalities, as the stream's turbidities, with only a few exceptions, are below the permissible criteria for surface supply throughout the year at all locations. The major effect, therefore, of the increased TSS lev~ls may contribute to a degradation and alteration of the river's fishery, as turbidity-TSS levels at Laurel would classify the stream as only fair through the March-to-July period (European Inland Fisheries Ad- visory Commission 1965). In addition, the river tends to warm below Big Timber. 89 This, in turn, may also reduce the potential of the river as a cold-water fishery. Median temperatures were usually higher at Laurel than at Corwin Springs (except in the winter), and temperatures greater than 19.5°C were more common in the Laurel segment. Since 1970, 16.7 percent of the minimum daily temperatures in the Yellowstone at Billings, about 36 river miles be- low Laurel, were in excess of 19.5°C with 11.5 percent equal to or greater than 20.0°C (USDI l966-1974b); this contrasts with the smaller, once-daily percentages obtained for the Yellowstone at Livingston. These varying ob- servations correspond to the classifications of the river bebteen Big Timber and Laurel to Custer as a transition zone fishery, changing from a cold-water stream above Big Timber to a warm-water stream belo~t the confluence of the Bighorn River (Peterman 1977). The Yellowstone River above Laurel appears to be non-eutrophic as concen- trations of phosphorus and nitrogen were usually below the designated criti- cal levels (0.05 mg P/1 and 0.35 mg N/1). For the most part, nutrient con-· centrations, particularly nitrogen, were well below the reference levels specified by the EPA (USEPA 1974b)--O. 1 mg P/1 and 0.9 mg N/1. On the basis of nutrient concentrations, the river at Corwin Springs makes the closest approach to eutrophy, particularly during the winter-to-spring (table 25). Due to Yellowstone National Park influences, median phosphorus concentrations in the river at this upper station exceeded the reference criteria; however, median nitrogen concentrations were below this value, apparently preventing eutrophication. Below Conlin Springs, phosphorus levels generally tended to decline downstream with the exception of a marked increase at Laurel during the March-to-July period (table 28). These high phosphorus concentrations at Laurel might have been derived from confluences to the river below Columbus, possibly in association with high flows and sediment inputs, as TSS levels were also high during this period. Ho~tever, extremely low nitrogen concentra- tions again apparently precluded the development of eutrophic conditions. Other than this spring-summer pulse of phosphorus at Laurel, no seasonal trends were evident in this variable at any of the stations. Nitrogen concentrations also tended to decline downstream from Corwin Springs, and they were noticeably low in the river at Laurel. Nitrogen levels were consistently low during the summer period when the river's flora would be in full bloom. There appeared to be a nitrogen peak during the dormant winter season when biotic uptake would be at a minimum, and concentrations were high in the spring. The general declines in phosphorus and nitrogen downstream might have been due to tributary dilutions below Corwin Springs or to the pro- gressive use of these nutrients by the stream's periphyton. The upper river appears to be more nitrogen-than phosphorus-limited. The average median con- centration of phosphorus equalled 109 percent of its reference level in con- trast to 28 percent for nitrogen. These observations of nitrogen limitation and non-eutrophy in the upper Yellowstone are in accordance with Klarich's (lg76) conclusions concerning the Yellowstone between Laurel and Huntley. Due to the low total alkalinities of the upper Yellowstone (the state average is 134 mg/1 Caco 3 ) (Botz and Peterson lg76), the river would be sen- sitive to acid discharges. However, the river does not appear to be affected in this manner since the ranges of pH in the stream are closely coincidental 1·1ith the range that is typical of most natural waters: 6.0 to 8.5 units (Hem 1970). ~1edian pH's for all locations and seasons are well 1~ithin the 90 , r ' ' standards established for B-D1 streams (table B); thus, pH should not detract from the river's beneficial use as a sport fishery or for livestock and muni- cipal supply. Seasonal trends in pH are not obvious, although relatively low pH values were obtained during the high flows in association with the reduced alkalinities at this time. In addition, median pH tended to decline upstream in correspondence with the decrease in total alkalinity and bicarbonate. Dissolved oxygen (DO) levels in the upper Yellowstone are also in accord with· the stream's value as a fishery and municipal supply. f·1inimum DO concen- trations at all stations, even during the warm-weather periods, were ~~ell above the critical value specified by the state's water quality standards for B-D 1 streams (r~ontana DHES undated). ~led ian DO concentrations were very near saturation in the upper Yellowstone (table 29); individual samples.varied be- tween 92 percent and 124 percent of saturation. This aspect and the generally low five-~ay BOD's of the river samples indicate no extensive organic pollu- tion in the upper Yellowstone drainage. For example, about 90 percent of the samples had BODs values less than or equal to 3.0 mg/1, while 98 percent had BODs values less than S.O mg/1. The general absence of allochthonous organic matter in the upper river is confirmed by the low total organic carbon (TOC) and chemical oxygen demand (COD) concentrations of the samples (table 29). Median TOC levels in the upper Yellowstone were actually less than an average _value (10 mg/1) obtained from unpolluted waters (Lee and Hoodley 1967). In addition to the data available for the major parameters su~narized in tables 25-28 for the upper Yellowstone River, some data are also available for various trace elements, such as metals, and for other constituents such as color, TOC, COD, and MBAS (methylene blue active substances). Since these data are generally not abundant, stations were combined to expand the data base of these parameters into two reaches of the upper river--a reach above Livingston to Corwin Springs, and one extending from Livingston to Laurel. The total recoverable and the dissolved concentrations of the trace elements were compiled separately, as applicable, because a metal's dissolved compon- ent represents a subset of its total recoverable concentrations, i.e., total recoverable should exceed dissolved. A summary of the trace element concen- trations and the other minor constituent levels for the two reaches are pre- sented in table 29. None of the miscellaneous, non-metal constituent concentrations in the upper Yellowstone suggest pollution problems. Silica concentrations were high above Livingston, which is probably accounted for by the alumino-silicate type of rock in the stream's drainage in Yellowstone National Park (Boyd 1961 ). However, silica concentrations declined below Livingston, and the median value in this reach was equal to the median value for the nation's surface waters (Davis 1964). Cyanide (CN) was not detected in any of the samples examined for this constituent, and the general lack of MBAS reactions in the samples indicates an absence of synthetic detergents in the river (USDI l966-1974b). The median oil and grease value was below state standards (table 8), although one of the samples collected for this analysis exceeded this criteria. Fecal colifonns were low at all stations for most of the year, indicating a general absence of marked municipal pollution reaching the river. Fecal levels were below state criteria, and fecal coliforms, along with boron, were well be- neath the recommended levels of the NTAC and the EPA .for public (and livestock) water supplies (table 9). In addition, boron concentrations in the upper 91 "' "' TABLE 29. Summary of trace element and miscellaneous constituent concentrations measured in the Yellowstone River above the confluence of the Clarks Fork Yellowstone River. Yellowstone River between Yellowstone River above Livingston Livingston and Laurel Total Recoverable Metals and Total Recoverable Metals and Miscellaneous Constituents Dissolved Metals Miscellaneous Constituents N Min Max Med N Min Max Med N Min Max Med COD 16 1 40 11 Color 5 1 4 3 CN 7 0.0 0.0 0.0 Do a 16 92 124 102 MBAS 12 0.0 0.1 0.0 NHrN 20 0.0 0.29 0.06 15 0.02 0.43 0.07 0& 2 3 13 8 Si 26 17 24 20 5 0.0 16 14 TOC 2 3 6 4.5 18 2. 1 14 5.7 Ag 12 0.0 .001 0.0 As 4 <.01 . 031 .020 11 0.0 .030 .012 10 <.01 .022 .011 B 18 <. 1 . 34 0. 1 46 .054 .630 .316 19 <. 10 0.29 0.12 Ba 4 0.0 0.0 0.0 Be 10 0.0 0.0 0.0 Cd 19 <.001 <.01 <.001 12 0.0 .001 0.0 23 <.001 <.01 <.001 Co 4 0.0 0.0 0.0 Cr 8 0.0 <.01 0.0 6 0.0 . 001 0.0 6 <.01 <. 01 <.01 Cu 19 <.01 0.01 <.01 12 0.0 .056 .008 27 <.004 0.040 <.01 Fe 19 . 10 1.8 .42 95 0.0 .326 .020 27 .05 . 9.8 .55 Hg 12 <.0002 0.0003 <.0002 7 0.0 .0018 .0001 13 <.0002 0.0012 <.0002 (0.15?) Mn 18 <.01 0.26 0.04 23 0.0 .760 .013 26 <.01 0.32 0.11 Mo 12 0.0 .009 .003 Ni 12 0.0 .023 .001 Pb 19 <.01 <.05 <.05 12 0.0 .005 0.0 26 <.05 0.04 <.05 Se 7 0.0 .006 .004 4 0.0 .002 .001 Sr 15 <. 10 0.25 0.08 4 . 148 .224 .208 16 <.03 0.87 0.19 v 15 <.05 <.5 <.5 4 .001 .002 .001 16 <.05 <.5 <. 1 Zn 19 <.01 0.03 <. 01 12 0.0 .050 .010 27 <.01 0.58 <. 01 (1.1?) NOTE: Measurements expressed in mg/1. aDO expressed as percentage of saturation. Yellowstone are in accordance with the classification of the stream as a Class I water for irrigation, suitable for application to boron-sensitive crops · (tables 15-17). Ammonia concentrations were similar in both reaches of the upper river; ammonia levels were well below the permissible criteria and recommendations of the NTAC and the EPA for domestic use. At the median pH levels of the river, between 7.5 and 8.4 units, about two percent to twelve percent of the ammonia concentrations listed in table 29 would be in an un-ionized form and potentially toxic to aquatic life (USEPA 1973); this would afford median con- centrations of un-ionized ammonia in the stream between 0.001 mg N/1 and 0.008 mg N/1 and a maximum concentration of 0.05 mg N/1. However, these med- ian values are less than the criteria listed by the EPA for this constituent in relation to freshwater aquatic life (table 19), and they afford a minimal risk to the river's biota. In addition to its potential toxicity, ammonia can be used by aquatic plants as a nutrient and is a potential eutrophicant, as it may add to a water's nitrogen concentration. However, this does not appear to be true in the upper Yellowstone as median ammonia concentrations in the river would be at levels inadequate to increase inorganic nitrogen to the point of causing eutrophy. For example, the median (N02 + N0 3 )-N concentrations of the river at Corwin Springs in the winter (maximum eutrophic potential) plus the median NH 3-N value equalled only 0.33 mg fl/1, below the critical reference levels. The generally greater total recoverable (TR) levels of a trace element over its dissolved component are illustrated in table 29 for the As, Fe, and Mn data. High TR concentrations may indicate·a water quality problem, but not the specific problem because a large portion of the metal may be associated with particulate matter and therefore not free in the water. High dissolved concentrations of a metal would afford a more accurate diagnosis. However, low TR (and dissolved) levels of a trace element ~10uld definitely indicate the absence of those problems in a water associated with that particular con- stituent. On this basis, even though many of the trace elements were detected in low levels at least in some of the samples from the upper Yello~1stone, most do not appear to be at concentrations sufficient to detract from the water's use. As indicated in table 29, this would include most notably: Ag, Ba, Be, Cd, Co, Cr, Cu, Pb, and Zn; concentrations were usually well below the vari- ous reference criteria for aquatic life, for drinking water and public supply, and for livestock water and irrigation. Of the various metals, iron and manganese were most commonly found in high concentrations in the upper Yellowstone samples; the high TR levels were generally obtained in conjunction with high river flows and in association with the larger sediment concentrations. Total recoverable Fe and Mn concen- trations often exceeded the criteria for drinking water and public supply, and the former parameter often exceeded the recommended maximum concentration for freshwater aquatic life. As noted previously, however, TR concentrations are suggestive of potential problems only; the median dissolved concentrations of these two constituents would indicate that Fe and ~In, for the most part, do not detract from the beneficial uses of the upper river. This also ap- plies to most of the other trace elements that were commonly found in detec- table concentrations--B. Mo, Ni, Se, Sr, and V, and possibly As .. Arsenic levels 93 were also relatively high in the upper river, corresponding to the designation of this parameter as a potential nonpoint water,quality problem originating from Yello~1stone National Park and adjacent areas (Montana DHES 1975, J~ontana DHES 1976). Although median concentrations were above the American Public Health Service standard for drinking water (USDHEH 1962), they were below the permissible level designated by NTAC and below the recommendation of the EPA for public water supplies (table 9). In addition, arsenic concentrations tended to decline downstream, posing a less critical problem for the river at Laurel, and this parameter does not appear to be at hazardous levels for the river's biota. Of more immediate interest are the occasionally high TR levels obtained for mercury in excess of the criteria for aquatic life and public supply. Particularly notable is the fact that the high median dissolved concentrations of mercury are greater than the average level recommended for freshwater life by the EPA (table 19). Thus, high mercury levels may actually represent a greater water quality problem for the upper drainage than arsenic, and this parameter definitely merits further consideration in future monitoring pro- grams. Some pesticide and herbicide data are also available for the Laurel and Corwin Springs stations on the Yellowstone River. In contrast to mercury, however, these potential pollutants apparently have no effect on the water· quality in the stream. Of the 332 analyses for these various chemical con- stituents 114 parameters including lindane; DDT; endrin; 2,4,5-T; and silvex), only one parameter in one sample (0.3 percent of the analyses) was found in detectable concentrations--2,4-D at 0.04 ~g/1 (USDI 1966-1974b). In summary, it may be easily concluded that an excellent water quality generally enters the primary survey area from the upper reaches of the Yellow- s tone River. YELLOWSTONE RIVER--CLARKS FORK RIVER TO BIGHORN RIVER YELLOWSTONE t~I NSTETI Several tributary streams of varying flo~/ magnitudes enter the mainstem through this reach. These can be classified into three groups: (1) the large streams, the Clarks Fork Yellowstone River, and Pryor Creek, which have a dis- tinct loading potential and thereby a potential to affect water quality in the mainstem; (2) various intermediate streams, such as Fly Creek; and (3) numerous streams with small flows, such as Duck Creek, Blue Creek, and Alkali Creek; these creeks probably exert minor individual effects on the mainstem but may have cumulative influences on the river's quality as the Yellowstone passes through this study reach. The Clarks Fork River is the largest of these tri- butaries and was defined as occupying the eastern segment of the secondary study area. As a result, the quality of water in this river will not be directly inventoried in this survey. However, several reports are available that have considered the quality of water in the Clarks Fork River in detail (Karp et al. 1976a, Karp et al. 1976b, Klarich 1976), and this information will be used as a reference point for assessing the potential effects of the Clarks Fork on the mainstem. 94 Considerable amounts of USGS water quality data are available for the Yellowstone River at Billings (table 3). In addition, lesser amounts of data have been collected by this agency for three other locations on this reach as supplemented by state WQB data (table 6)--near Laurel (below the Clarks Fork), at Billings, at Huntley, and at Custer. This information is ·summarized in tables 30-33 for the major parameters. The data in table 31 for the Yellowstone River at Billings is probably most representative of the river's overall quality in this segment due to the greater period of col- lection. The Yellowstone in the Laurel-to-Custer reach has a calcium-bicarbonate type of water, and sodium and sulfate are secondary ionic constituents. r·1ag- nesium, potassium, and chloride are again minor components of the water and have no major effect on the river's quality in terms of its various bene- ficial uses. This is also true of fluoride with concentrations at low levels in this downstream segment in comparison to the river at Cor1~in Springs. The concentrations of these four minor constituents varied inversely with flow and are at the same levels observed for the river at Laurel (table 29). In contrast to the downstream increase in magnesium and the downstream decrease in fluoride and chloride noted for the upper river, the concentrations of these four minor constituents remained remarkably constant throughout the Laurel-to-Custer segment of the stream. The primary and secondary ions also varied inversely with flow, but in contrast to the minor constituents,· these components tended to increase downstream in relation to the Yellowstone at Laurel as a reference point. As a result, the increase in salinity (total dis- solved solids or specific conductance) observed for the upper river continues to occur through the Billings segment of the mainstem. On the basis of these dissolved constituents, the quality of water in the Yellowstone is best at upstream sites during the periods of higher flow. In contrast to the upper river, the downstream increase of salinity in the Laurel-to-Custer reach was greatest during the August-to-October period (rather than at high flows) and ranged between 50 percent and 68 percent in the vicinity of Laurel, and from 91 percent to 113 percent for the entire segment. The increase near Laurel was probably a reflection of the confluence of the Clarks Fork Yellm~stone River which has high specific conductances in comparison to the mainstem (Karp et al. 1976a, Karp et al. lg76b, Klarich 1976). Through the remainder of the year, the increase in salinity ~1as lowest during. the winter (7 percent to 23 percent near Laurel and 40 percent to 47 percent for the segment) and somewhat higher during the spring-to-summer period (23 percent to 49 percent near Laurel and 55 percent to 82 percent overall). The overall increase in salinity was much greater through the 91-mile Laurel-to- Custer segment of the stream than for the 158-mile stretch of the upper river-- a maximum increase of about 1.1 percent per river-mile and a minimum of 0.5 percent per mile below Laurel versus a maximum salinity increase of 0.2 per- cent per mile and a minimum of about 0.05 percent per river-mile above Laurel. For the entire reach of the river from Corwin Springs to Custer, salinity in- creased between 70 percent and 122 percent during low-flow periods and between 122 percent and 150 percent during the high-flow period, indicating a definite downstream degradation in mainstem ~later quality. Regardless of the marked increases in salinity, the entire Laurel-to- Custer segment of the river remains non-saline in character (Robinove et al. 1958); however, it becomes more typically hard in nature in this reach, 95 "' "' TABLE 30. Summary of the physical parameters measured in the Yellowstone River near Laurel below the confluence of the Clarks Fork Yellowstone River (Duck Creek Bridge). August-October November-February March-April May-July N Min ~1ax Med N Min Max Med N Min Max Med N Min Max Flow 13 1300 8980 4100 13 1300 4620 2930 7 1330 5340 3590 10 1200 41,800 Temp 11 3.0 22.0 12.0 13 0.0 4.0 0.0 6 2.0 10.5 7.3 11 10.0 20.0 pH 12 7 .I 8.6 8.2 13 7.2 8. 3 8.0 5 7.8 8.4 8.2 10 7.2 8.2 sc 12 238 430 368 11 240 580 420 6 360 610 460 11 140 490 TDS 12 160 295 253 13 207 337 264 6 222 304 273 11 90 197 Turb 4 2.0 14 4.4 5 4.0 20 4.0 2 10 70 40 5 13 300 TSS 1 ----14.4 1 ----10 0 ------2 214 226 DO 11 7 .a 11.6 9.6 12 10.2 13.1 12.3 6 7.2 12.6 10.8 11 8.0 9.5 BOD 10 0.4 2.4 1.6 13 o. 5 2.6 1.3 5 1.3 2.7 1.8 11 1.0 5.2 FC 6 27 420 70 6 6 390 13 7 4 70 30 7 70 1800 Ca 9 22 41 32 9 37 47 42 4 33 42 40 8 12 28 Mg 9 7. 1 15 12 9 9. 7 14 14 4 11 14 13 8 3.3 8.8 TH 12 84 186 137 13 125 180 159 6 130 184 159 11 44 114 Na 5 14 27 21 3 21 29 24 2 23 25 24 4 7.0 21 K I -- -- 2.4 1 -- -- 3.2 0 ---- -- I -- -- SAR 3 0.6 0.8 0.8 1 ----1. 0 0 ---- -- 2 0.3 0.4 HC0 3 3 106 147 128 1 ----160 0 ------2 79 106 TA 6 89 159 122 5 121 186 134 2 127 190 159 5 65 102 504 9 29 85 56 12 51 90 72 6 55 91 77 10 11 53 Cl 8 4.3 7.0 4.8 9 4.7 17 7.3 4 4.6 6.8 5.8 7 1.4 3. I F 4 0.3 0.6 0.4 4 0.4 0.7 0.6 2 0.6 0.6 0.6 4 0.1 0. 3 N 11 0.01 0.61 0.04 11 0.10 0.50 0.30 6 0.0 0. 20 0.11 11 0.03 0.40 p 12 0.01 0.19 0.04 11 0.0 0.49 0.02 6 0.04 0.15 0.11 11 0.0 1.2 NOTE: Measurements expressed in mg/1. Med 14,100 13.5 7.8 215 150 58 220 8.6 1.5 390 19 4.7 76 8.2 1.4 0.4 93 87 24 2.6 0.2 0.10 0.20 -• TABLE 31. Summary of the physical parameters measured 1n the Yellowstone River at Billings. August-October November-February March-Apri 1 May-July N Min Max Med N Min Max Med N Min Max Med N Min Max l~ed Flow 44 2600 20,000 5BBO 59 1330 5370 3330 27 2550 7610 3680 52 3390 6Z,BOO 1_8 ,060 Temp 25 3. 5 22.5 19.0 30 0.0 6.3 0.5 15 0.5 IZ.B 6.0 30 B.5 21.9 15.4 pH 41 6.B B. 7 7 .B 57 7.2 B.5 B.O 27 7.4 B.6 7 .B 57 7.0 B.2 7.7 sc 43 252 5BZ 34B 57 340 602 439 27 265 4B3 422 57 liB 549 193 TOS 37 157 301 232 54 210 415 276 27 159 306 260 52 7B 352 132 Turb 5 7.7 76 15 1 ----9 0 -- ----10 zz 88 49 TS_S 12 6 222 26 14 z 110 7 4 7 I 30 64 20 19 430 153 00 1 ----8. 3 1 ----12.1 0 ------3 8. 7 9.4 9.4 BOO 1 ----1.9 I ----9.3 0 ------3 2.4 3.2 2.5 I FC I ----56.000 I ----2230 1 -- --20 3 40 2210 745 Ca 21 22 41 34 31 34 51 43 16 34 47 40 24 14 46 19 Mg 21 B. I I 7 12 33 10 20 14 18 12 16 14 25 3. 1 18 6.3 Til 38 B9 211 137 56 130 207 168 27 104 180 155 52 28 190 83 I Ia 39 16 41 24 57 21 40 27 27 16 35 27 51 5.8 46 " K IB 2.4 4.2 2.7 34 2.5 7. I 3.4 15 2.8 4.6 3.5 19 1.2 7.7 1.8 SAR 38 0.7 1.2 0.8 56 0.8 1.2 0.9 27 0. 7 1.2 1.0 52 0.3 1.5 0.6 IIC0 3 38 103 187 143 55 128 202 163 27 117 172 153 52 56 197 92 TA I ----99 I ----151 0 ------4 55 98 67 504 39 39 I 36 60 57 49 118 81 27 36 103 77 51 12 120 24 Cl 21 3.5 6.6 5.2 33 3.5 10 6.6 1B 6.4 10 . 7.8 25 1.1 8.8 2. 9 F 18 0.3 0.8 0.5 32 0. 3 0.7 0.5 15 0. 3 1.1 0.6 21 0.1 0.6 0.3 N 26 0.0 1.2 0.08 39 0.0 0.64 0.25 20 0.0 0.64 0.10 29 0.01 0.95 0.08 p 14 0.0 0. 12 0.04 19 0.01 0.12 0.03 10 0.0 0." 0.06 14 0.0 0.19 0.03 NOTE: r~easurements expressed in mg/1. <.0 ::0 TABLE 32. Summary of the physical parameters measured in the Yellowstone River at Huntley. August-October November-February March-Apri 1 N Min Mo• fled N Min Max Med N Min Max Flow II 3BOO 9420 7230 6 2700 5400 3190 B 2790 B530 Temp 10 B.O 24.5 17.3 9 0.0 5.5 1.0 9 2.0 14.0 pH 11 7.6 B.6 B.2 7 7.3 B.3 7.7 B 7.4 B. 5 sc 11 290 470 380 B 400 540 494 B 269 523 lOS 11 166 316 239 B 254 412 302 B 163 332 Turb 5 5 80 7 2 8 20 14 6 1 90 TSS 5 8 . 190 20 2 30.5 82 56.3 6 10 254 DO 11 7.4 12.0 B.4 7 B.2 12.9 12.3 B B. 9 11.4 BOO 10 1.4 3.2 2.0 6 2.0 3.3 2.4 5 2.5 7.0 FC 11 91 2000 560 7 B 2300 220 10 24 570 Ca 6 2B 43 36 B 36 52 44 5 37 44 Mg 7 9.6 16 12 8 13 19 16 5 11 17 TH 7 67 170 132 8 140 204 175 5 136 1BO Na 7 19 33 22 B 25 35 33 5 22 35 K 2 2.5 2.8 2. 7 2 3.1 4.3 3.6 2 3.8 4.1 SAR 7 0.8 1.1 0.9 8 0.9 1.1 1.1 5 O.B 1.1 HC0 3 2 123 148 136 3 169 174 174 3 137 170 TA 7 92 129 116 7 120 166 139 5 112 139 504 7 55 96 68 8 73 122 100 5 64 110 C1 7 4.3 6.8 5.2 8 5.9 9.9 8.2 5 4.6 9. 7 F 6 0.4 0.6 0.5 5 0.4 0.6 0.6 2 0.5 0.6 N 8 0.05 0. 31 0.09 6 0.17 0.38 0.29 7 0.13 0.42 p 8 0.01 0.17 0.06 6 0.04 0.28 0.07 7 0.05 0.29 NOTE: Measurements expressed 1n mg(l. May-July Med tl Min Max Med 3930 11 6700 63,300 14,400 B.O 12 B.O 21.0 15.5 7. 9 12 6.9 B. 3 7.B5 440 12 145 4BO 210 295 12 B9 297 145 55 8 2 100 45 146 B 21 51B 124 10.3 12 7.5 10.7 B. 7 2.6 10 1.0 5.0 2.2 290 11 120 530 2400 42 7 15 43 19 15 7 3.6 15 6.9 170 7 57 170 76 31 7 6.8 35 13 4.0 3 1.4 2.1 2.0 1.1 7 0.4 1.2 0.7 164 3 69 128 81 135 7 50 152 71 91 7 13 93 33 7.7 7 1.5 5.7 . 3.0 0.6 6 0.2 0.5 0.3 0.15 11 0.0 0.30 O.OB 0.15 11 0.03 0.54 0.11 -... . .... TABLE 33. Summary of the physical parameters measured in the Yellowstone River at Custer. August-October flovember-Februa ry March-Apri 1 <:: May-July rl ~1i n Max Hed N Min Hax l~ed rl Min Max Med rl Min Hax Mod Flow 4 3550 8890 3850 7 2900 4200 3400 3 3000 5700 3200 5 11 ,400 42,000 17,000 Temp 4 3.5 21.3 18.7 6 0.0 1.5 0.0 3 3.5 15.2 4.5 6 13.0 22.0 14.3 pH 5 6.8 8.6 8.29 6 7.8 8.3 8.1 2 7. 9 8.0 8.0 6 7.5 8.08 7.75 sc 4 328 557 468 4 430 562 504 3 397 590 480 6 185 361 288 TOS 5 255 366 321 6 JOB 437 345 3 287 360 333 6 149 279 215 Turb 4 7 10 9. 5 6 3.0 10 9 3 30 60 55 6 41 300 113 TSS 1 ----26.8 2 22 73 48 1 ----73 3 240 514 292 DO 5 7.6 12.4 10.2 6 9.8 13.6 12.4 3 8.9 11.4 10.2 6 8.2 10.6 9.3 BOD 4 0.4 2.4 2.0 6 1.7 8.1 2.2 3 2.6 4.1 2.8 6 0.2 5.5 4.2 FC 1 ----3315 2 40 148 94 1 ----66 3 <10 9200 230 Ca 2 29 39 34 2 51 53 52 1 ----39 3 22 34 32 M9 2 11 18 15 2 8.4 23 16 1 ----11 3 6.0 12 9.1 TH 5 116 207 172 6 165 222 180 3 143 198 161 6 79 134 103 1/a 3 23 31 30 4 33 37 37. 1 ----25 4 10 25 20 K 3 2. 6 3. 6 2.8 3 3.1 4.2 4.1 0 -- ----3 1.6 2.5 2.4 SAR 2 0.9 1.0 1.0 2 1.1 1.1 1.1 1 ----0.9 3 0.5 0.9 0.6 I/C0 3 2 127 147 137 2 154 185 170 1 ----141 3 87 134 128 lA 5 103 172 131 6 127 167 148 2 116 154 135 6 71 110 97 504 5 58 96 91 6 95 129 104 3 46 lOB 64 6 21 68 47 Cl 2 4.6 6.1 5.4 2 7.0 8.2 7.6 1 -- -- 6.0 3 1.8 3.6 3.5 F 3 0.3 0.8 0.4 3 0.3 0.6 0.5 0 ------4 0.2 0.4 0.2 N 5 0.0 0.61 0.02 5 0.20 0. 75 0.39 J 0.10 0.28 0.17 6 0.0 0.61 0.28 p 5 0.02 0.55 0.11 6 0.02 0.24 0.08 3 0.05 0.28 0.15 6 0.0 0.88 0.33 rlQTE: Measurements e,(pressed in mg/1. rather than soft or moderately hard, and therefore it is not an ideal public supply (Bean 1972). In addition, this reach is not as desirable a source for municipal water as it is upstream due to the increases in sulfate and total dissolved solids. Nevertheless, on the basis of tloe dissolved common con- stituents, the water in the Laurel-to-Custer reach of the Yellowstone is suit- able for this use and has an excellent quality for the watering of all live- stock, as sulfate, chloride, and total dissolved solids concentrations (and bicarbonate, calcium, magnesium, and sodium levels) were well below the rec- ommended maximum criteria for these applications (tables 9-14). Given these aspects .Plus the 1 ow SAR va 1 ues of the samples, the river between Laure 1 and Custer possesses a low sodium hazard and a medium salinity hazard for irrigation (Richards 1954) and a Class I type of water that may be successfully applied to most crop and forage species (tables 15-17). In addition, this reach of the river should also be suitable for the support of viable fresh-1 water communities. As described previously, 400 mg/1 of total dissolved solids 1 represents a general threshold guideline for distinguishing the possible ef- fects of salinity on the aquatic biota. Although total dissolved solids oc- casionally exceeded 400 mg/1 below Billings during low-flow periods, these occurrences were quite rare and would not be expected to adversely influence the river's biota on a long-term basis. In addition to the increase in total dissolved solids concentrations to Custer, a downstream change in chemical composition is also evident in the Laurel-to-Custer reach of the Yellowstone River. This alteration represents a general reversal of the trends described for the upper river. In the upper segment, the water tends to become more calcium bicarbonate towards Laurel with tributary inputs generally negating the 1~ater quality characteristics originating in Yellowstone National Park. Below Laurel, the proportions of sodium and sulfate in the river tend to increase to Custer. These changes can be illustrated by Ca/Na and HC03/S04 ratios as follows in table 34. TABLE 34. Proportions of sodium and sulfate in the Yell01~stone River below Laurel Ca/Na HC01/S04 Low Flows High Flows Low Flows High fl 0~/S at Corwin Springs 0. 79 1.00 2.18 5.08 at Laurel above the Clarks Fork 1. 51 2.36 3.73 5.71 near Laurel below the Clarks Fork 1.65 2. 31 2.33 3.87 at Billings 1.49 1. 72 2.12 3.83 at Huntley 1.44 1.46 1.88 2.45 at Custer 1. 37 1.60 1. 78 2.72 NOTE: Measurements expressed in mg/1. I I I I I ~ ! Both ratios tend to increase from Corwin Springs to Laurel above the Clarks Fork, but then tend to decline downstream in the mainstem below Laurel. This is a probable reflection of the more sodium sulfate type of streams with prairi· drainages that join the river below Laurel in contrast to the calcium bicarbon· ate type of tributaries that drain the mountainous areas of the upper reach. The influences of the Clarks Fork Yellowston~ River Iabove Laurel versus the point near Laurel below the Clarks Fork) in increasing the proportion of sul- fate in the mainstem while not affecting its sodium levels are quite distinct. This tributary tends to have a calcium sulfate type of water (Karp et al. 1976c In addition, the two ratios are highest during the high-flow periods when in- fluences from the upstream calcium bicarbonate tributaries would be most pro- nounced in relation to the magnitude of the downstream inputs with their sodiur, sulfate types of 1~a ters. In contrast to total dissolved solids, suspended solids-turbidity con- centrations are directly related to the magnitude of flow. As a result, tur- bidity-TSS levels in the river below Laurel were low during the low-flow seasons and markedly increased during runoff periods. Thus, these physical factors tended to detract from the better 1~ater quality that occurs during the high flows as a result of the reduced total dissolved solids concentrations. In general, turbidity-TSS levels tended to be higher in the reach of the river below Laurel than for the mainstem above the Clarks Fork River at Laurel (tables 28 and 30). However, given the purported sediment load of the Clarks Fork Yellowstone River (Beartooth Resource Conservation Development Project et al. 1973), this increase was not as distinctive as might be expected, averaging 20 percent and 23 percent for turbidity and TSS, respectively, at low flows, and averaging 93 percent and 108 percent at high flows. In ad- dition, although not totally consistent from site to site through all seasons, these parameters also continued to increase downstream through the Laurel-to- Custer segment. For the most part, turbidity was not at adequate levels in the Laurel-to- Custer segment to preclude the use of this water as a public supply. Only a few samples had turbidities in excess of 75 JTU (table 9), and these were most commonly collected during high flows, although occasionally high turbidities were also obtained during most seasons through the stations. The occurrences of high turbidity were much more frequent in this reach of the river than up- stream; this is suggestive of a less suitable source for municipal use in terms of water treatment costs. The sporadic collections of high turbidity samples were probably associated with runoff events in the surrounding drainage below Laurel, e.g., from the Clarks Fork Yellowstone River and from Pryor Creek (Karp et al. 1975b}. The turbidity problem was most pronounced in the Yellow- stone at Custer, particularly during the May-to-July period when median levels ~1ere in excess of the 75 JTU reference value. The major effect of TSS in this reach of the Yellowstone appears to be related to aesthetics and to a potential degradation of the Yellowstone salmon- id fishery. Bishop (1974} suggests that the high spring sediment loads of the Clarks Fork River and the Yellowstone near and below Laurel generally eliminat1 these stretches of water as spawning grounds for trout; the salmonids require gravel bars that are relatively free of sediment for the successful incubation of redds (Peters 1962). This then may account for the general decline of the trout fishery between Laurel and Huntley (Karp et al. 1976b, Marcuson and Bishop 1973}, although temperature may also play an instrumental role. 101 I ! . However, other fish species are not as sensitive to sediment as trout in terms of their spawning activities, and these, therefore, could establish a resident population within this reach if sediment levels are not delimiting for other reasons. As noted, this fishery would probably be ~tarm-water in character; a downstream increase in the proportion of warm-water species along with a cor- responding decline in the salmonid forms has been observed for the Laurel-to- Custer segment of the river (Karp et al. 1976b). Sediment levels during low-flow periods enable the Yellowstone to serve as an excellent fishery immediately below Laurel, and good-to-moderate below Billings. Ho~tever, at high flows the fishery would be fair-to-poor at all locations (European Inland Fisheries Advisory Commission 1965). As described previously, fish may be able to survive temporary slugs of high sediment con- centrations (e.g., during a high-flow period) but not sustained applications at high levels. As a result, the yearly ~edian sediment concentration at a location may provide an index to assess the overall intensity of sediment ex- posure according to the classification scheme of the European Inland Fisheries Advisory Committee (1965). Using this index, the Yellowstone River should provide a good-to-moderate fishery in the Laurel-to-Huntley segment with an- nual median TSS levels ranging between 58 and 88 mg/1, while providing a fair fishery in the vicinity of Custer ~tith a yearly median on the order of 108 mg/1. Potential pollutive influences from the Billings area on this Laurel- to-Custer fishery are considered in another report (Karp et al. 1976b). A major portion of the Yellowstone reach below Laurel has been classified a B-0 3 stream, i.e., a warm-water fishery (Montana DHES undated). This is in accora with the temperature characteristics of the stream at Billings des- cribed previously and in accord with the high maximum, ~tarm-~teather tempera- tures obtained throughout the reach (tables 30-33). Oxygen concentrations are also appropriate for this designation and for a B-D 1 stream (table 8), as minimum DO's were well above 5.0 mg/1 and always in excess of 7.0 mg/1. Med- ian DO's were very near saturation (96 percent) and varied between 85 percent and lll percent. Similarly, pH values were in accord with the criteria for a B-D3 stream. Thus, neither extremely high pH's nor extremely 101~ pH's (i.e., >g.o or <6.0) would negate any beneficial river uses. During high-flow per- iods, pH tended to be lowest, in association with the low total alkalinities at these times. Median phosphorus concentrations in the Laurel-to-Custer segment of the Yellowstone were higher in the spring and during the high-flow period than in the summer and winter. With the exception of the Billings station (table 31), the March-July pulse of phosphorus first observed in the river at Laurel (table 28) was also evident downstream to Custer. During the summer high-. growth period and during winter, phosphorus levels generally increased down- stream below Laurel. At Laurel and Billings during these two seasons, phos- phorus concentrations in the river were less than the reference criteria diagnostic of eutrophic conditions (tables 30 and 31); however, phosphorus exceeded this value (0.05 mg P/1) at Huntley and at Custer (tables 32 and 33), although lower than the criteria established by the EPA (USEPA 1974b). In terms of nuisance algal blooms, the development of high phosphorus levels would be more critical during the summer months than during the dormant winter season. Median phosphorus concentrations were generally in excess of the EPA's (1974b) reference criteria (0.1 mg P/1) during the March-to-July period at all stations. 102 These aspects suggest eutrophic conditions in the Yellowstone below Laurel at most stations during most seasons. However, median nitrogen concentrations were typically below the reference value for this parameter, possibly preventing the development of nuisance plant gr011ths. Nitrogen did not exhibit any dis- tinct downstream trends, although concentrations appeared to be highest in the mainstem at Custer. Nitrogen levels ~1ere lowest during the summer period of high biological activity and nutrient uptake, and highest during the cold weath- er period. The Laurel-to-Custer segment appears to be nitrogen-limited and non- eutrophic at present, but this reach is much closer to eutrophy than the stretch of water above Laurel. The Laurel-to-Custer reach appears to be particularly vulnerable to eventual eutrophication if nitrogen inputs to the river are in- creased. Of the eight sites considered so far, the Yellowstone at Custer is the most representative of eutrophic conditions. In association with the high percentage of DO saturations, the low BODs values of the Laurel-to-Custer segment indicate the general absence of exten- sive organic pollution. This is confirmed by the generally low median TOC (less than average) and COD concentrations ( tab.l e 36). However, this effect appears to be slightly more prominent in this reach than in the upper river, po~sibly in response to influences emanating from the more urbanized Laurel-Billings areas (e.g., wastewater treatment plant discharges). These aspects can be illustrated as follows in table 3S. TABLE 3S. BODs values and median TOC and COD concentrations Laurel and in the Laurel-to-Custer reach. above Average Number Samples Uniquely High River Reach BODs BODs>S mg/1 BODs Values Median TOC Median COD Above Laurel l . 9 mg/1 2 6. l mg/l S. 6 mg/l ll mg/l Laurel-to-7.0,8.1, Custer 2. 2 mg/l 6 to 8 and 9.3 mg/1 6.4 mg/l 19 mg/1 The problem of organic pollution is discussed more fully in a report prepared by the state WQB (Karp et al. l976b). Trace element and minor constituent concentrations in the Yellowstone be- tween Laurel and Custer are presented in table 36. This summary involves an amalgamation of sites as described for the upper river in order to increase the data base of each parameter. The data in table 36 indicate the absence of sev- eral potential water quality problems from the stream: l) synthetic detergents (t.IBAS values very low); 2) cyanide (generally undetectable); 3) oil and grease (values typically near zero and less than state standards; 4) organic pollution (TOC and COD concentrations low); S) aesthetics-color (color usually unnoticeable to the human eye); and 6) ammonia (low levels of the non-ionic toxic form). 103 TABL£ 36 Sl.Cmldry of tr.1ce ele=lent and ciscellaneous constituent concentrdtion l!'('dsu.-ed in t~ ~ellowstone River between ldurel dnd Custer Yellowstone River near ldurel (Duck and at Billings Tota I Recoverable Metah oJnd Miscellaneous Constituents " Min "" ""' '" 9 0.0 0.01 0.0 coo Color 27 0 27 ] oo• MBA.S 12 0.0 0.03 0.0 NH 3-N 56 0.0 2.4 0.05 O&G Phenols 4 <.001 0.002 0.002 Si 10C A9 A1 ,, B B• Be Cd Co ,, '" re H9 u "" "' fli Pb s. 5c ' '" " B. 7 10 14 2 1 B 5 ] ( .001 0.016 0.010 10 <. 10 0. 17 <. 10 I ----< .01 11 <. 001 <' 01 <.001 1 ----( .01 13 a.o < .01 o.a 11 <.01 <.01 <.01 11 0.14 • '9 0.62 s <.0002 <.001 <.0002 (. 33?) J 0.03 0. 75 .050 11 <.01 0.21 0.05 9 <.01 < .05 < .05 1 --·-<.001 7 < .03 0.28 0.23 ' <.05 '· 5 <. 10 11 <.01 0.02 < .01 flDT£: i'Ceasure~~~ents e•pressed In 1111]/1. a{)() eAprt'SSI!d dS ~rcentage Of SaturdtiOn. bBe:<.Ol ,11•1; Co:<.OI ,tl•l. 'Be:<.ODJ ,N=Z. II 14 J " 64 6 11 17 9 7 16 " s 15 " " 17 • s 6 17 Creek Bridqe) Oissohed ~u1s "'" ,., a. a .002 .096 . zoo 0. 0 .OliO 0.009 0. 504 0.0 o.a o.a .007 o.a .001 0.0 .001 0.0 o.a 0.0 .0~2 0.0 0. 374 0.0 .0003 0.0 .060 0.0 .008 a.o .008 0.0 .014 .006 .040 . 140 .530 .001 .006 0.0 .047 Yello><~Stone River at lluntley dnd at Cuner toul Recoverdble 14et8hb and Olnolved Hetahc Mt ue 1\aneou~ ConstItuent\ ""' II Hlo ... "'' II Min ""' "'' 16 • 68 19 5 I 6 • 18 85 Ill " 12 0.0 o. 02 0.0 28 0.0 0.58 o. 12 12 0 7 a 2 0.002 0.003 0.003 • 10 14 13 17 1.1 16 6.6 a.a 4 a.o .001 .0005 '100 . 007 • .001 .022 .01{) 4 .003 .010 . 009 0.170 11 <. 10 0. JO 0. 14 • .106 .228 . 137 o.a 4 a.o 0.0 o.a 0.0 0.0 14 < .001 < .01 <. 001 4 0.0 .001 o.o 0.0 4 0.0 0.0 0.0 0.0 B o.o < .01 < .01 .aO< 10 <.01 0. 05 ~ .01 4 .007 .025 .012 0.0< 19 0. 24 9.] 1.5 • .040 .211 .084 .0001 9 0.0 0.001 < 0001 I ----< 01 . 011 19 .10 .OJ .39 • .011 .at)) .029 0.0 • .002 .Oil .004 .001 • o.a .015 .002 0.0 " <.01 <.I ... 05 • 0.0 0.0 0.0 .009 5 < .001 0.003 0.002 . 408 9 0.03 0. 70 0.30 • . 336 . 510 .455 .001 10 ".05 0. 27 '' 1 • .0009 .003 .0016 .017 19 ( .0\ 0.\1 <.01 • .021 .052 .037 104 However, ammonia-N may.contribute more significantly to the eutrophic potential of the Laurel-to-Custer reach than upstream as inorganic (NOz + N03)-N concen- trations were close to the critical reference criteria in the downstream segment. In addition, the TR levels of several metals indicate that these trace elements pose no problems to any of the water uses. This includes boron (irrigation), Be, Cd, Co, Cr, Cu, Pb, V, and Zn. This is substantiated by the low dissolved con- centrations of these constituents, and on this basis, Ag, Ba, Li, Ho, Ni, and Se might also be eliminated from consideration as possible water quality pro- blems. Median silica concentrations in the Laurel-to-Custer segment were similar to those observed in the river at Laurel and about equal to the national average for surface 1·1a ters (Davis 1964). Stront i urn 1 eve 1 s, on the other hand, tended to increase downstream from Corwin Springs. Median Sr concentrations ~1ere some1~hat higher than the average levels in major North American rivers (0.06 mg/1) (Durum and Haffty 1963), and higher than the median content of the larger public water supplies (0. 11 mg/1) (Hem 1970). However, strontium has not generally been known to be toxic {r1cKee and Wolf 1974); the major interest in this element lies in its chemical similarity to calcium and in its radioactive Sr-90 isotope which can replace calcium in various biochemical reactions. However, the concentra- tions of strontium in the Yellowstone do not appear to be at adequate levels to allow its Sr-90 proportion to constitute a water quality hazard. For example, Sr-go is a beta emitter, and dissolved gross beta levels in the Yellowstone at Billings (ranging bet1~een 2.5 PC/1 and 7.8 PC/1 with a median of4.3 PC/1) were below the criteria established for the State of Montana (table 8) and well below the desirable level established by the NTAC (1968) for surface water-public sup- ply (table g). In addition, Sr levels in the Yellowstone were much lower than concentrations in some natural waters that have been utilized as a domestic supply (e.g., 52 mg/1) (Hem 1970). r1cKee and Holf (1974) point out that the major hazard of Sr-90 " ... lies not in direct consumption but in plants and fish that accumulate this element." The high arsenic and mercury levels described for the upper Yellowstone are apparently carried into the Laurel-to-Custer reach of the river (table 36). However, arsenic does not appear to be a water quality problem in this section as its dissolved concentrations were generally belo1~ the Public Health Service (1962) drinking water standard and far below the criteria for freshwater aquatic life (USEPA 1973). In contrast, the median dissolved concentration of mercury was again above the average level recommended for the aquatic biota (as observed for the upper river), and grab sample concentrations also occasionally exceeded this criteria as well as the standard for surface-municipal supply. A review of the water quality data from the Yellowstone below Custer indicates that detec- table mercury levels are also present in the lo~1er river. As a result, mercury, along with the phenols and fecal coliforms, appear to represent the major water quality problems in the Laurel-to-Custer segment of the river. As indicated in tables 30-33, median fecal coliform levels were often in excess of the state's criteria for the average number of organisms that should be present at any B-D stream location, and grab samples were also often in ex- cess of the maximum criteria for this parameter (Montana DHES undated), parti- cularly at high flows. But median fecal concentrations were generally less than the more lenient NTAC and EPA criteria (table 9) for surface water and municipal supply. In comparison to the upper river, markedly high fecal levels were 1115 occasionally obtained (>2000 colonies, per 100 ml) that exceeded even these latter standards. These violations become progressively more common in a down- stream direction as the river passes through the urbanized areas of Laurel and Billings. In addition to the coliform problem, early water quality surveys of the Yello~tstone revealed a flavoring of fish flesh and drinking water in this seg- ment, attributed to high concentrations of phenolic compounds (Montana Board of Health et al. 1956, Spindler undated). With the recent development of better waste11ater treatment systems at oil refineries in the Laurel-Billings area (Montana DHES 1972), the concentrations of phenols no~t appear to be at border- line levels in the river in relation to these taste and odor problems (table 19). However, phenol levels in the Laurel-to-Custer reach are still in excess of drinking water and public supply criteria (USEPA 1973, USDI 1968, USDHEW 1962) and are also in excess of tl1e EPA's (1974b) national inventory, reference cri- teria (USEPA 1974b). In consideration of fecal coliform and phenol violations, the state WQB is completing a waste load investigation of the Yellov1stone be- t11een Laurel and Huntley where these parameters form the focal point of the allocation (Karp et al. 1976b). Hith the operation of a new secondary sewage treatment plant at Billings, and with the continued improvement of oil refinery effluents, the fecal coliform and phenol problems may ultimately decline to non- critical levels. For the time being, hov1ever, these parameters are real pro- blems in the Yellowstone River. Overall concentrations of trace elements tended to increase downstream below Corwin Springs. This can be illustrated by the median TR and dissolved (Dis) concentrations of Sr, Fe, and Mn as follows in table 3~ TABLE 37. t·1edian TR and dissolved concentrations of Sr, Fe, and ~1n below Corwin Springs Total Recoverable Dissolved Concentrations A B c D A B c D Stront'ium 0.08 0. 19 0.23 0.30 0.208 --0.408 0.455 Iron 0.42 0.55 0.62 1.5 0.020 --0.04 0.084 f4anganese 0.04 0. ll 0.05 0.39 0.013 --0.05 0.029 NOTE: A, B, C, and D represent sequential downstream reaches of the river. Regardless of such increases, most of the trace elements do not appear to pre- sent a 1·1ater quality problem to the lower sections. The greater TR over dis- solved concentrations in a sample are illustrated by the Fe and t·1n data; how- ever, this does not apply to Sr for some unknol'ln reason. Downstream increases in TR (and thereby dissolved levels) are possibly related to the downstream in- creases in suspended sediment. In turn, the high maximum TR concentrations of Fe and i·1n were generally obtained in conjunction with the occurrence of high sediment loads. Of the various metals, the concentrations of Fe and Mn 11ere typically the highest, affording the greatest probability of exceeding water quality criteria. A comparison of the above TR concentrations to various stan- dards suggests that Fe and ~1n levels did exceed many of the reference values; this is not borne out by their dissolved concentrations, which v1ere typically HHi less than the criteria for municipal supply, stockwater, irrigation, and aquatic life. Thus, these trace elements do not appear to detract from the river's qual- ity, even though they can exhibit high TR levels. This is illustrative of the fact that high TR concentrations are only suggestive of possible water quality prob 1 ems, meriting careful consideration and i nterpreta ti on. As indicated previously, radiochemical data from the Yellowstone River at Billings (USDI 1966-1974b) point to a general absence of this type of problem in the stream. This is also the case for the herbicides and pesticides. Similar to the gross beta concentrations, dissolved radium concentrations were well be- low the state and NTAC criteria for this parameter (tables Band 9); Ra-226 ranged between 0.01 PC/1 and 0.11 PC/1 with a median of 0.055 PC/1. Dissolved uranium concentrations ranged between 0.16 ~g/1 and 3.2 ~g/1 with median of 1.7 ~g/1. Of the 761 individual pesticide and herbicide analyses (fourteen para- meters) on samples from the Yellowstone near Laurel and at Billings, only 1.05 percent demonstrated detectable levels, about 3.5 times greater than the detec- tion success at Corwin Springs. The parameter most commonly detected was 2,4-D (with a range of 0.02 ~g/1 to 0.42 ~g/1 and a median of 0.045 ~g/1 at N=6). Also detected were 2,4,5-T (0.01 pg/1) and DDT (0.01 pg/1) in single samples. All of these concentrations are ~1ell below levels that have been shown to di- rectly affect rainbow trout (McKee and Wolf lg74), e.g., 2.2 mg/1 for 2,4-D and 24 to 74 ~g/1 for DDT. MISCELLANEOUS TRIBUTARIES A number of small streams join the Yellowstone River between Laurel and Custer. Some partial chemical data are available for most of these creeks as a result of the state l'JQB's waste load allocation investigation of the mainstem (Karp et al. 1976b), but this information was not reviewed for this inventory. Complete chemical analyses were performed on single grab samples from three of these streams as summarized in table 38, which also includes data from a small tributary to Pryor Creek. These data should provide some insight into the type of water that enters the mainstem via these small streams. Of the four streams, Canyon Creek is unique, as it receives irrigation return flo~1s originating from the Yellowstone River. As evident in table 38, this factor probably produces a dilution of its natural quality. For example, total dissolved solids levels in Canyon Creek are only slightly higher than those in the Yellowstone near Laurel. Temperature, pH, turbidity-TSS, DO, and BOD 5 values of single samples from each stream are not suggestive of pollutive cond1tions in their drainages. In addition, phosphorus and nitrogen concentrations did not indicate eutrophic con- ditions. In contrast, the few data that are available consistently indicate the occurrence of high fecal coliform concentrations in these streams in excess of state standards; this may produce a cumulative fecal loading on the mainstem which corresponds to the downstream increase in this variable. Most noticeable in these tributaries, except in Canyon Creek, are the high dissolved solids- specific conductance levels, suggestive of a generally poor water quality. However, the small flows of these streams probably preclude most water uses other than stock watering. On the basis of TDS, these streams might be rated generally good for stock watering. Ho1~ever, East Fork Creek is unsuitable, and Duck and Spring creeks may also be unsuitable as sulfate concentrations were in 107 TABLE 38. Summary of the physical parameters measured in Spring, Duck, and Canyon creeks (minor Yellowstone tributaries), and in East Fork Creek (a minor tributary to Pryor Creek). Spring Creek Duck Creek Canyon Creek East Fork Creek Flow 1. 39 1. 58 260 2.0 Temp 16.0 171 10.5 pH 8.17 8.38 7.80 8. 30 sc 2410 2903 494 5030 TDS 1895 2298 366 4567 Turb 4 TSS 9 1.5 73 16 DO 12 0 1 12 0 1 10.9 9.9 BOD 3 0 1 2.5 2.3 FC 800 3450 >1000 Ca 104 164 40 228 Mg 58 95 18 243 TH 500 800 172 1570 Na 380 390 35 800 K SAR 7.4 6.0 1.2 8.8 HC03 293 283 156 430 TA 241 236 128 363 so4 1053 1358 109 2820 CI 2.5 6.0 7.7 40 F N 0.79 0.02 0.04 0.0 p 0.01 < .01 0.06 0.01 NOTE: Measurements expressed in mg/1. excess of the limiting level for stock (tables 10-14). In turn, these waters would be unfit for human consumption and would be Class II type waters for irri- gation given their high SAR values and TDS concentrations. The potential cumulative effect of these small streams on the mainstem is most obvious in terms of high TDS and specific conductance levels. Several such sequential inputs would act to increase the TDS levels of the Yellowstone. For example, ten tributaries having the flow and chemical characteristics of Duck Creek in table 38 could increase the TDS concentration of the mainstem about three percent to four percent from that in the river near Laurel. In addition, the sodium sulfate nature of these small streams is in accord with the gradual increase in the proportion of these parameters from Laurel to Custer in the mainstem. PRYOR, ARROW, AND FLY CREEKS These streams also JOln the Yellowstone in its Laurel-to-Custer segment. Next to the Clarks Fork Yellowstone River, Pryor Creek is the major tributary 1 fl!l D through this reach, and, therefore, it could have a significant effect on main- stem water quality. However, very little water-quality information is available on Pryor Creek other than that collected by the state WQB as part of its water- quality management plans (Karp and Botz 1975). Samples were collected from the stream's upper drainage and from a station near its mouth at Huntley; however, data from these samples were insufficient to allow for a seasonal or flow-based classification of the creek's quality. Fly. and Arrow creeks have lower discharges than Pryor Creek and may be con- sidered intermediate tributaries in the Laurel-to-Custer segment, as they have higher flows than such streams as Duck and Spring creeks. Adequate data are available on Arrow Creek through a state WQB irrigation return flow sampling program to allow for a flow classification of the stream's quality, but detail is insufficient for a seasonal separation. Most water quality information for these Laurel-to-Custer tributaries is available on Fly Creek since the USGS has maintained a monitoring station on this stream for several years (table 3). This allowed for a seasonal classification of the water quality data from Fly Creek as applied to the Yellowstone River. Data on the minor constituents and trace elements in these tributaries were relatively sparse, both in the number of parameters analyzed and in the number of analyses per parameter. As a result, these data from the streams were combin• to provide one statistical summary (table 39). With the exception of a few occasionally high readings for some of the metals (e.g., zinc), most of the tracE elements do not appear to be at levels sufficient to suggest water quality pro- blems. As observed on the mainstem, median iron and manganese concentrations were high, but it should be noted that these were TR levels and should be con- sidered in that context. For example, dissolved iron concentrations in Fly Creek were well below the various water quality criteria, but dissolved mangan- ese concentrations were high and exceeded the standards for drinking water and surface water supply (although they were at levels safe for other uses). Silica concentrations in Fly Creek equalled the national average for surface waters, and the water in this creek was generally uncolored. However, TDC levels in Fly Creek were higher than in the mainstem, indicating a greater than average concentration of organic matter, but this was not reflected in the BOD levels of the creek. Therefore, although the high manganese concentrat i ens may degrade water quality, major water-quality problems in these tributaries are apparently related to the high concentrations of certain major parameters (tables 40 and 41 Fecal coliform concentrations in Pryor Creek and the intermediate streams were high and occasionally in excess of state standards; pH and DO levels in the streams were within state criteria and did not indicate pollution. Median soo 5 levels were probably higher overall than those in the mainstem, but they were less than 5.0 mg/1 in all cases and did not suggest extensive organic pollution. With the exception of Arrow Creek at high-flow periods, these tributary streams were generally non-eutrophic with phosphorus levels below the critical referenc( criteria. Nitrogen levels were occasionally high in the streams (in Arrow Cree~ and in Fly Creek during the winter), but for the most part, the concentrations of this parameter were well below the levels that indicate eutrophic conditions. Grab sample temperatures usually did not reveal any conspicuous values, although high warm-weather readings were obtained from Pryor Creek on a few occasions; this is not consistent with the stream's B-D1 designation (Montana DHES, undated 109 TABLE 39. Summary of trace element and miscellaneous constituent concentrations measured in various secondary streams in the Yellowstone drainage between Laurel and Custer. Fly Creek Fly Creek plus other streams Miscellaneous Constituents and Dissolved Metals Total Recoverable Metals N Min Max Med N Min Max ~led Color 38 2 40 6 Si 175 5.0 18 14 TOC 3 37 50 37 As 18 <.001 0.02 <.01 B 79 0.010 0.530 0.277 4 <. 10 0.56 0.13 Cd 22 <. 001 0.001 <.001 Cr 2 <.01 <.01 <.01 Cu 22 <.01 0.02 0. 01 Fe 112 0.0 0. 70 0.02 21 . 10 21 .55 Hg 7 <.001 <.001 <.001 ( .007?) Mn 11 0.0 0.190 0.080 18 <.01 1.7 0.18 Pb 9 ·<. 01 <. 01 <.01 ( . 04?) v 2 <.05 <.05 <.05 Zn 20 <.01 0.14 0.01 NOTE: Measurements expressed in mg/1. In addition, the consistently high turbidity-TSS levels in Pryor Creek suggest a poor fishery (European Inland Fisheries Advisory Commission 1965) which is also contrary to its B-Dl designation. Although most obvious in Pryor Creek, turbid- ity-TSS levels could also be high in Fly and Arrow creeks (particularly at high flows), and this may partially account for the downstream increase in suspended sediment that occurs in the mainstem towards Custer. Probably the most obvious water quality attribute of these tributary streams is their high lOS-specific conductance levels which were two to seven times higher than those in the mainstem at Huntley (table 32) during low-flow periods. Sequential inputs of such waters to the Yellowstone probably accounts for at least part of the downstream increase in TDS between Laurel and Custer. However, these particular streams would have a greater effect on the mainstem than Duck Creek, for example, due to their higher flows and greater TDS loads. The median data for Pryor Creek indicate that this tributary could increase the winter TDS level in the Yellowstone about nine percent below their confluence at Huntley. Although these tributaries are non-saline or only slightly saline (Arrow and Fly creeks at low flows), their waters were very hard and their TDS concentrations consistently exceeded the recommendations for drinking water and public supply (table 9). In addition, sulfate concentrations often exceeded these criteria (particularly at low flows), and turbidities in Pryor Creek were generally greater than that deemed desirable for this use. As a result, the waters in these three tributaries are probably not suitable for municipal supply 110 ...... ...... ...... --· ·--· --· --· ------------------------ TABLE 40. Summary of the physical parameters measured in the Pryor Creek drainage and in Arrow Creek near Ballantine~Worden. Upper Pryor Creek Drain- age near Pryor Pryor Creek at Huntley Arrow Creek (<16 cfs) Arrow Creek (>16 cfs) N Min Max Med N Min Max Med N Min Max Med N Min Max Med Flow 6 5 72 22 4 106 582 222 11 0.3 15.3 2.0 8 36.3 150 104 Temp 6 0.0 7.2 2.8 8 0.0 29.4 11. 3 12 0.0 19.0 11.4 7 13.0 18.5 16.5 pH 6 7.90 8.40 8.20 8 8.00 8.60 8.30 12 7.98 8.48 8.16 8 7.68 8.40 7. 86 sc 6 480 1184 773 9 804 1460 982 12 1353 1850 1565 8 470 894 628 TOS 6 409 898 606 7 666 850 722 3 1078 1317 1130 2 497 651 574 Turb 5 10 175 120 6 39 160 86 12 1 24 6.3 8 8.2 89 36 TSS 6 26 427 122 7 <25 3436 711 11 7.1 61 22 8 19 266 117 00 6 10.3 13.3 11.8 7 7.8 12.6 10.0 3 , . 1 14. 1 13.1 0 -- ---- BOO 4 1.8 3.8 3.3 6 1.8 4.2 3.3 3 2.4 3.2 3.2 0 ------ FC 6 <100 >1000 >100 5 40 1060 140 2 <100 860 --0 ------ Ca 6 55 93 68 7 60 85 66 3 85 104 88 2 48 54 51 Mg 20 32 25 7 31 45 35 3 65 73 66 2 22 25 24 TH 6 218 361 283 7 279 355 339 3 479 560 490 2 211 238 225 Na 6 7.0 121 67 7 54 128 75 3 126 168 136 2 56 88 72 K 3 12 34 25 1 ----4.5 0 ------2 4.0 4.1 4.1 SAR 6 0.2 2.8 1.8 7 1.3 3.3 1.8 3 2.5 3.1 2.7 2 1.7 2.5 2.1 HC0 3 6 228 382 253 7 203 317 268 3 357 397 363 2 209 255 232 TA 6 187 240 210 7 167 268 226 3 293 326 298 2 171 209 190 504 6 34 419 201 7 162 348 262 3 426 568 469 2 148 215 182 C1 6 0.0 8.0 2.6 7 6.3 27 8.2 3 4.2 13 12 2 8.6 9.4 9.0 F 3 0.3 0.4 0.4 4 0.4 0.6 0.5 2 0.3 0. 3 0. 3 2 0.5 0.6 0.6 N 6 0.0 0.14 0.08 7 0.03 0. 68 0.11 12 0.02 1.5 0.73 8 0.27 . 0.81 0.67 ( 10?) p 6 0.01 0.11 0.02 7 0.01 0.25 0.04 12 < .01 0.05 0.03 7 0.03 0.25 0.11 NOTE: 11easurements expressed t n m9!l. ' lt....\ ..... ...... N TABLE 41. Summary of the physical pdrarreters measured in Fly Creek clt Pompeys Pillar. Au gus t-Oe to be r November-february flarch-April N r-1in Max Med N r-lin Max Mcd N ,..lin Max Flow 50 10 148 51 44 2.5 76 7 8. 5 30 6.0 2050 Temp 8 12.0 18.5 14.5 7 0. 5 2.5 2.0 8 0.0 7.0 pH 43 7.6 8.3 8.0 44 7.5 8. 4 8.1 30 7.3 8.4 sc 48 747 2120 1025 44 344 1B80 2245 30 312 3020 TDS 48 471 1620 717 44 232 2230 1720 30 204 2370 Tur··b 0 ------1 ----5 2 5 6.5 TSS 0 ------0 -- ----2 15 21 00 0 ------I ----13.1 2 13.0 13.4 BOO 0 ------I ----2.4 2 3.6 4.8 FC 0 ---- -- 0 ------2 5 <100 Ca 48 50 101 64 44 27 140 106 30 26 145 Mg 48 27 91 37 44 9.7 120 91 30 8.8 119 TH 43 240 660 327 44 110 820 640 30 101 802 IJd 48 66 300 108 44 30 410 304 30 20 468 K 48 1.5 6.0 4.4 44 4.3 8. 3 5.3 30 4.5 7.5 SAR 48 2.6 1.8 5.2 44 1.3 6.5 5.2 30 0. 9 7.5 HC0 3 48 202 441 264 44 80 503 393 30 94 464 TA 0 ------1 ----380 1 ---- $04 48 190 890 324 44 110 1300 950 30 67 1390 Cl 48 4.2 15 8.3 44 3.1 29 15 30 2.0 37 f 48 0.3 0.8 0.5 44 0.1 0. 7 0.5 30 0. 2 0.6 II 46 0.0 0.45 0.04 41 0.0 0.68 0.36 32 0.0 0.68 p 39 0.0 0.11 0.03 38 0.0 0.21 0.02 28 0.0 0.11 Hay-July Med II 1-lin r1ax Med 11 53 7.8 241 51 2.0 7 10.0 20.0 15.5 8.1 52 7. 3 8. 3 8.0 2355 53 404 2960 942 1775 53 265 2190 640 5.8 1 -- -- 47 18 1 ----168 13.2 1 ----8.7 4.2 1 ----3.4 --I ----280 110 53 31 120 57 86 53 12 110 34 655 53 130 750 280 323 53 31 440 110 5.6 53 2.0 10 3.6 5.7 53 1.2 7.0 2.8 363 53 117 357 191 364 1 -- -- 118 980 53 93 1300 324 22 53 19 32 8.1 0.4 53 0.1 0.9 0.3 0.08 53 0.0 0. 35 0.01 0.02 44 0.0 0.10 0.03 if other sources are available. The high TDS concentrations of the streams were due primarily to sodium, calcium, bicarbonate, and sulfate, the major ionic con- stituents; relative proportions varied depending upon the stream, reach, and flow regime. Magnesium concentrations were somewhat higher in these streams than in the Yellowstone, although fluoride, chloride, and potassium were again minor constituents in the waters. The water quality in Pryor Creek is apparently somewhat better in its upper drainage where the composition is calcium-sodium-bicarbonate; however, TDS levels were still high even in this creek's headwaters region. TDS concentrations in- creased downstream to the creek's mouth, accompanied by a shift in ionic propor- tions so that the stream became, like the Clarks Fork Yellowstone River, more calcium sulfate in nature with almost equal proportions of the majo~ cations and the major anions. This is probably a reflection of the inputs of tributaries such as East Fork Creek (table 38), which have sodium sulfate waters and high specific conductances. Due to the low sodium concentrations, Pryor Creek has a low sodium hazard for irrigation; this, and its medium-to-high salinity hazard and low boron levels indicated that Pryor Creek has a borderline Class I-II water for irrigation. As a result, this water should be applied cautiously to salinity- sensitive forage and crop plants. However, the water in Pryor Creek is excellent for watering stock animals. Water quality in Arrow Creek is definitely related to flow; the stream shows a 50 percent to 60 percent reduction in salinity with a better water qual- ity during the high-flow periods. With discharge in excess of 16 cfs, the water in Arrow Creek has a calcium bicarbonate-composition, but during.low flows the stream is sodium sulfate in character. These features may reflect the irriga- tion return flows that enter the creek. These returns would tend to increase the creek's flow, dilute the stream's initial quality, and alter its ionic character from a sodium sulfate water to one more characteristic of the original source of the irrigation water (e.g., the calcium bicarbonate type of water in the Yellowstone River). Thus, in small prairie streams such as Arrow and Canyon creeks, irrigation return flows probably have a ·beneficial effect in increasing discharge and in improving an otherwise naturally poor water quality. As a· result, although the water quality in Arrow Creek is probably excellent during all seasons for stock, it is more beneficial during the high-flow irrigation return flow periods. Of the three Laurel-to-Custer tributaries, the more eastern Fly Creek (table 41) has the poorest water quality, but only because of its high salinity levels. Although based on slight evidence, pH, temperature, dissolved oxygen, BOD 5 , and most trace element levels (except manganese) did not indicate water quality problems in the drainage. In addition, TSS and fecal coliform concen- trations are not at particularly high concentrations in comparison to those observed in other streams, such as Pryor Creek and in the Yellowstone River at Huntley. The major water quality problem in Fly Creek, TDS, is definitely flow- related, with a better quality evident during high-flow periods. Surprisingly, highest flows were obtained during the summer-early fall, perhaps reflecting irrigation returns (Durfor and Becker 1964). The waters in Fly Creek are sod- ium sulfate in nature during all seasons, although this is most prominent during the low-flow winter-spring seasons when irrigation returns would be at a minimum. The downstream increase fn the proportions of sodium and sulfate in the Yellow- stone mainstem is probably related to the sequential inputs of tributaries such 113 as Fly Creek. During high flows, the water in Fly Creek is applicable to all stock, but this use may be curtailed during the November-to-March period as sulfate concentrations in the stream approach levels limiting to animals at this time (approaching 1000 mg/1) (tables 10-14). This is another example of the beneficial aspects of irrigation return flows reaching these small prairie streams. Using only the May-to-October data, Fly Creek has a high salinity hazard for irrigation, but low sodium and boron hazards (tables 15 and 16). However, with the high TDS and sulfate concentrations, this stream is best classified as Class II, which should not be applied to salinity-sensitive plants. As spe- cified by the EPA (1976), TDS concentrations of 500-1000 mg/1 indicate" ... a water which can have detrimental effects on sensitive crops." In addition, the salinity levels in ·Fly Creek, as well as in Arrow and Pryor creeks, are approach- ing concentrations which may affect freshwater biota. Median TDS concentrations in Fly Creek during the winter and spring definitely exceed the maximum value that allows for the support of a good mixed fish fauna (Ellis 1944). As a result, the biotic structure and composition of these saline streams might be consider- ably different from that in streams with much lower TDS concentrations. Along with the high TSS levels (and the possibility of high summer temperatures), the high salinity levels would also operate against the designation of Pryor Creek as a B-D1 class water. · · LITTLE BIGHORN RIVER DRAINAGE LITTLE BIGHORN RIVER MAINSTEM The Little Bighorn River is the major tributary of the Bighorn River in Montana. Considerable water quality information on the river is available from the USGS, and this has been supplemented by state WQB collections in the drain- age (table 6). The USGS maintains two water quality sampling stations on the Little Bighorn--one near Wyola (near the Montana-Wyoming state border) and one near Hardin near the confluence of the stream with the Bighorn River. A stretch of river about 50 miles long separates the two USGS stations .. As illustrated in table 42, a good-to-excellent water quality enters Montana from Wyoming via this river. The upper Little Bighorn River is classified as a B-Dj stream; dissolved oxygen, pH, and fecal coliform levels in the stream near Wyo a were well within the state standards for this designation. Grab sample temperatures were also generally within this criteria, although a few tempera- tures during the summer exceeded 19.40C. These factors, along with the low BODs levels of the water samples, indicate no pollution problems in the river's upper drainage. Total dissolved solids in the Little Bighorn were inversely related to flow, but TDS concentrations and specific conductance levels in the upper stream were low even during the periods of reduced discharge. For example, TDS concentrations in the upper Little Bighorn River were only about 6.7 percent to.8.7 percent higher than those in the Yellowstone at Custer during the low-flow August-to- February period, and about 18 percent to 29 percent higher during the high-flow period of March-to-July. The waters in the upper Little Bighorn had a predomi- nantly calcium bicarbonate composition during the entire year. Sodium and magnesium, the secondary cations, were found in nearly equal concentrations; 114 ..... ...... 01 TABLE 42. Summary of the physical parameters measured in the Little Bighorn River ncar Wyola. August-October Novembe r-'F eb rua ry March-Apri 1 II Min Max Med N Min Max Med N Min Max Flow 27 115 281 145 44 58 439 130 26 65 551 Temp 19 6.0 22.0 16.0 24 0.0 7.0 0.5 13 0.0 8.0 pH 21 7.6 8. 3 8.1 40 7.2 8.5 8.15 24 7.6 8.5 sc 26 482 673 556 44 413 675 596 26 350 759 TDS 27 3D6 404 349 43 266 526 368 26 281 566 Turb D ---- -- 2 2 lD 6 1 ---- TSS 12 21 248 62 13 22 346 49 7 18 799 DO 0 ---- -- 2 12.3 13.4 12.9 2 12.3 12.5 BOD 0 ------2 2.5 3.2 2.9 1 ---- FC D ------2 0 3 2 1 0 9 Ca 27 55 70 63 43 43 81 67 26 40 78 M9 27 21 31 26 43 16 33 27 26 16 38 TH 27 250 300 260 43 17D 330 280 26 180 313 Na 27 13 27 21 43 17 40 22 26 9.4 50 K 27 0.9 2.2 1.6 42 1.0 4.5 1.6 25 1.3 8 SAR 27 0.4 0. 7 0.6 43 0.4 1.1 0.6 26 0. 3 1.3 HC0 3 27 229 288 249 43 171 292 248 26 166 279 TA 3 195 219 216 5 209 231 216 4 136 229 504 27 81 120 100 43 85 160 120 26 22 190 Cl 27 0.8 3.0 1.4 43 0.4 3. 1 1.5 26 0.2 4 F 27 0.0 0.7 0.2 42 0.1 0.5 0.2 26 0.1 0.5 II 23 0.0 o. 10 0.01 39 0.0 0.50 0.10 26 0.0 0.42 p 17 0.0 0.07 0.02 20 0.0 0.09 0.02 10 0.01 0.21 NOTE: Measurements expressed in mg/1. May-July Med II Min Max Med 187 39 174 1820 611 2.5 17 5.4 18.0 10.5 8.1 34 7.3 8. 5 8.1 600 39 314 712 424 43D 39 193 462 255 0 2 6 14 lD 51 9 9.0 125D 216 12.4 2 1D.9 11.5 11.2 2.8 2 1.5 2.9 2.2 5 2 12 20 16 68 39 37 70 52 30 39 13 31 18 299 39 170 303 210 35 39 1.3 47 10 2.3 37 0.7 7.8 1.3 0.9 39 0.0 1.2 0. 3 247 39 170 256 214 202 5 149 203 189 170 38 13 178 54 2.0 39 0.2 3.0 1.1 0.2 37 0.0 0.4 0.2 0.03 39 0.0 0.4 0.01 0.03 14 0.0 0.06 0.02 sulfate was the secondary anion. Although the waters were non-saline, they were very hard (Bean 1962, Durfor and Becker 1964) due to the high calcium and mag- nesium levels. SAR values were low for this same reason. Chloride, fluoride, and potassium concentrations were insignificant in the samples, and phosphorus and nitrogen levels were also remarkably low in comparison to other streams in the study area and in comparison to their reference criteria. The low phosphorus and nitrogen levels indicate non-eutrophic conditions in the upper river. On the basis of the major parameters, therefore, waters in the upper Little Bighorn River appear to be suitable for the following beneficial uses: 1) stock animals--TDS, common constituents, fluoride, and nitrate- nitrite concentrations were at below-threshold levels (tables 10-14); 2) irrigation--the water has a low sodium, medium salinity hazard, and due to the low SAR, chloride, sulfate, and TDS-specific conductance levels, it is a Class I water suitable for application to most crop and forage plants (tables 15-17); 3) drinking water and surface water public supply--TDS, fecal coliforms, nitrate-nitrite, DO, pH, chloride, sulfate, and fluoride levels were in accord with the permissible criteria, standards, and recommenda- tions given in table 9; and 4) freshwater aquatic life--TDS concentrations were generally less than 400 mg/1 and consistently less than 670 mg/1. The low fluoride concentrations in the Little Bighorn indicate the need for ac- cessory fluoridation in order to reach the optimum level for drinking water (USDHEW 1962). Of the major parameters summarized in table 42, the high TSS levels may detract from the stream's quality to the greatest degree. As observed on the Yellowstone River, TSS levels were directly related to flow, with highest median concentrations during the May-to-July high runoff period. Through the remainder of the year in the upper river, median seasonal concentrations were generally similar and much lower, although high levels of sediment 1~ere obtained spora- dically during all seasons in response to meteorological runoff events. The overall sediment levels in the river might have been sufficient to reduce the value of the stream as a fishery. Using the index described previously to assess the Yellowstone River, the upper reach of the Little Bighorn probably has only a fair to moderate fishery, with an annual median TSS concentration of about 94 mg/1. In addition, although not evident in table 42 due to the lack of turbidity data, TSS levels in the upper river appeared to be high enough on some occasions to detrace from its use as a public supply. That is, TSS con- centrations in excess of 325 mg/1 were obtained during most seasons (e.~., the maximum concentrations in table 42); using the equation in Karp et al. (1976), this converts to a turbidity in excess of 75 JTU. This violates the NTAC per- missible criteria for public supply (table 9). In terms of median flow, the Little Bighorn River is beb1een 1.2 and 2.4 times larger near its mouth than at the state border, probably due to tributary inputs to the river below Wyola. The flow differences between sites varied by factors of 1.3 to 1.6 during the May-to-February period, and it was considerably greater in March-April (a factor of 2.4). This larger flow increase in the early spring was probably a reflection of runoff events in these tributaries lln because prairie streams have their spring flood phase earlier than streams with a mountainous drainage such as the upper Little Bighorn River. These differ- ences in flow regimes, in turn, would become evident in the greater downstream increases in mainstem flows at this time, as illustrated in table 43. In addi- tion, such relationships should also become evident in the water quality data since the prairie tributaries generally have a lesser water quality than the receiving stream. A comparison of tables 42 and 43 shows a general degradation of water quality through the 50-mile reach of the Little Bighorn River between Wyola and Hardin. This is probably related to tributary inputs of inferior quality, but was manifested primarily by increases in TDS and TSS rather than in parameters that are more directly descriptive of pollution problems. That is, BODs, pH, and DO levels in the lower segment were similar to those in the stream near Wyola, and, although fecal coliforms increased somewhat downstream, their con- centrations continued to be less than the state criteria for a B-D stream.· The river's lower segment is classified a B-D2 stream, corresponding with the higher maximum and median temperatures observed there (table 43), along with the greater frequency of grab sample temperatures exceeding 19.4°C. This change of classi- fication corresponds to the increase in yearly median TSS concentrations in the river from Wyola to Hardin (to 154 mg/1), also descriptive of a poorer fishery. TDS concentrations increased downstream from 27 percent to 43 percent, depending upon season. The increase was smallest during the summer when tribu- tary flows were at their lowest, and the increase was greatest in April-March when the tributaries probably had their high-flow periods. In addition, TSS concentrations in the mainstem near Hardin were lowest during the summer in correspondence to the reduced flows of the tributaries. Although TSS concentra- tions were highest during the spring runoff stage of the Little Bighorn in May- July, a distinct secondary pulse of sediment was also evident in March-April near Hardin, but absent upstream, also probably related to the earlier high flows of the tributaries. Sodium and sulfate levels were exceptionally high in March-April. As a result, the Little Bighorn River near Hardin, like the upper reach, was a calcium bicarbonate stream from May to February, but it had a calcium-sodium-bicarbonate-sulfate type of water in March-April when these constituents were present on an equivalent basis. With the exception of fluoride, all of the common constituents tended to increase in concentration below Wyola to some extent during some season, but increases in chloride, potassium, calcium, phosphorus, and nitrogen were small. Thus, the waters in the river remained non-eutrophic throughout its entire length. The downstream increase in TDS was related primarily to the greater concentrations of sodium and sulfate in the lower segment, although magnesium also increased significantly towards Hardin, producing a distinct increase in hardness. Such increases in TDS and changes in chemical composition may detract from the use of the lower river as a surface water public supply; this is related primarily to the high TDS levels, the river's extreme hardness, and the occasion- ally high turbidity and sulfate levels. The waters still have a low sodium hazard (low SAR's) and a medium salinity hazard for irrigation (Richards 1954), but they are probably less applicable to irrigation than upstream waters due to the higher salinities. The lower river becomes a borderline Class I water which could affect sensitive species (USEPA 1976). However, salinities probably would not affect the river's aquatic biota to a large extent, and the stream is an excellent source of water for all stock animals. 117 .. ...... ...... co TABLE 43. Summary of the physical parameters measured in the Little Bighorn River near Hardin. August·October November· February March-Apr; 1 N Min Max Med N Min Max Med N Min Max Flow 28 146 494 190 44 82 791 177 29 238 2160 Temp 19 6.5 29.0 17.0 25 0.0 6.0 0.0 12 0.0 14.0 pll 21 7. 7 8.4 8.1 37 7.3 8. 3 8.1 29 7.6 8.4 sc 26 635 819 696 41 503 1450 772 30 637 1290 -lOS 28 401 509 445 41 331 737 501 29 411 861 Turb 0 ------1 -- -- 23 2 48 51 TSS 15 15 280 72 18 30 338 80 11 84 1570 00 0 -- -- -- I -- -- 12. 1 2 II. 3 12.5 BOO 0 ------1 ----2.3 2 2.6 3.5 FC 0 ---- -- 1 ----70 2 10 25 Ca 28 54 73 59 44 44 100 71 29 48 87 Mg 28 30 37 34 43 20 52 38 28 25 54 111 29 260 330 290 41 190 60 320 29 220 440 II a 28 33 52 42 41 32 69 49 29 53 130 K 2B 0.9 3.3 2.7 43 2.2 5.7 2.B 2B 2.7 5.6 SAR 2B 0.9 1.3 1.1 44 1.0 I. 7 1.2 29 1. 3 2.7 HC0 3 28 220 2B5 246 44 162 410 2B4 29 lBO 323 TA 4 198 234 207 B 229 313 256 2 249 265 so 4 2B 140 210 170 41 140 260 200 29 lBO 410 Cl 2B ·1.5 4.3 3.0 44 2.4 7 3.2 29 2.2 B. 1 r 28 0.0 0.3 0.2 43 0.1 0.5 0.2 20 0.1 0.6 II 27 0.01 0.09 0.0 40 0.0 0.43 0.13 29 0.01 0.20 p IB 0.0 o.oa 0.02 24 0.0 0. In 0.02 11 0.01 0.27 NOTE: Measurements ex~ressed in mg/l. May-July Med N Min Max Med 448 41 150 2370 960 3.6 16 11.0 25.0 17.5 B. 1 38 7.4 8. 5 8.1 927 42 407 1240 573 614 43 251 867 356 50 2 24 41 33 189 13 87 1350 306 11.9 2 10.7 10.8 10.8 3. 1 2 2.5 2.6 2.6 13 2 28 51 35 72 43 48 81 58 40 43 17 51 26 348 43 200 410 250 74 43 13 130 28 4.4 41 1.4 5.8 2.3 1.7 43 0.4 2.8 0.8 274 43 206 300 242 257 5 171 221 209 270 43 50 450 110 4.4 43 1.0 7 2.0 0.2 41 0.0 0. 7 0.2 0.06 43 0.0 0.38 0.02 0.06 17 0.01 0.06 0.02 Some trace element data are-also available for the Little Bighorn River as summarized in table 44. Overall, concentrations were lower than those in the Yellowstone, indicating an excellent water class. For example, the median silica level in the Little Bighorn was about 50 percent of that in the Yellow- stone and well below the national average (Davis 1964). As a result, TSS and TDS appear to be the major problems detracting from water quality in the Little Bighorn River, and this appears to be generally true of most streams in the Yellowstone Basin. TRIBUTARY STREAMS Some water quality data are available on various tributaries to the Little Bighorn River as a result of a state WQB sampling program in the drainage. These streams are listed in table 44. The data are relatively sparse, however, and not conducive to a seasonal or flow-based water quality classification. As indicated in table 44, trace elements in these tributary streams were found in relatively low concentrations. Many of the TR levels of these constituents were never found in detectable concentrations in the samples; the metals that were detected were only occasionally or never observed in excess of water quality criteria. As examples, boron concentrations were well below the critical levels that would be detrimental to irrigation, and Co and V were always below the cri- teria for irrigation, stock water, and aquatic life. The few samples with mer- cury in detectable levels may be the major exceptions, although concentrations were not analyzed to adequately low levels to resolve the status of mercury in relation to the various reference criteria; this applies also to the Little Bighorn River. Of the metals, Fe and Mn were most commonly found in relatively high concentrations, but their median concentrations did not exceed any of the reference criteria. In addition, these were analyzed according to total recov- erable components and their dissolved concentrations would probably be relatively low and not indicative of water quality problems. Levels of pH, BOD, DO, and possibly the fecal coliform levels in most of the tributary streams do not appear to have water quality problems (table 45). In addition, all of these streams were non-eutrophic with low nitrogen and phosphorus concentrations; this in turn corresponds to the lack of downstream change in the eutrophic status of the Little Bighorn. Turbidity-TSS and fecal coliform levels may pose water quality problems-for Pass and Owl creeks, but this does not seem to be true for Lodge Grass Creek or for the various minor tributaries such as Reno Creek, where attention focuses primarily on the high TDS concentrations. The Little Bighorn tributaries had a calcium bicarbonate water (with the exception of a calcium sulfate water in Lodge Grass Creek), and their ionic compositions were quite similar to those in the mainstem near Hardin; i.e., Mg < Na < Ca and so 4 < HC0 3 with F and Cl insignificant. However, TDS concen- trations were distinctively higher in the tributaries than in the Little Bighorn, although a wide range of variation (between 10 percent and 257 percent) was evi- dent in these comparisons, depending upon the tributary stream, mainstem reach, and season. On the average, TDS levels in the tributaries were 131 percent higher than those in the upper reach of the mainstem and 68 percent higher than those in the Little Bighorn near Hardin. This ln turn corresponds to the down- stream increase in mainstem TDS concentrations. The tributary streams were very hard with low SAR values, and they created a high salinity hazard for use in 119 -N 0 TABLE 44. Summary of trace element and miscellaneous constituent concentrations measured in the Little Bighorn River drainage. Little Bighorn River Little Bighorn River Little Bighorn River near Wyola and near Little Bighorn River near Wyola near Hardin Hardin together tributariesa Miscellaneous Constituents and Dissolved Metals Total Recoverable Metals N Min Max Med N Min Max Med N Min Max Med N Min Max Med Si 130 5.2 11 7.2 140 4.5 13 7.6 As 4 <.001 <.01 <.01 5 <.001 <.01 <.01 B 37 0.0 0.320 0.075 62 0.009 0.151 0.108 2 .05 . 18 .115 2 .05 .23 . 14 Be 2 <.01 <.01 <.01 2 <.01 <.01 <.01 Cd 8 <.001 <.01 <.01 14 <.001 <.01 <.01 Co 2 <.01 <.01 <.01 2 . 01 .03 .02 Cr 3 <.01 0. 01 --2 <.01 <.01 <.01 Cu 8 <.01 0.01 <.01 14 <.01 <.01 <.01 Fe 103 0.0 0.16 0.02 113 0.0 0.20 0.01 8 . 13 2.5 .50 14 <.01 2.5 0.33 Hg 7 <.001 0.001 <.001 12 <.001 . 0.001 <.001 Li 2 . 01 . 01 . 01 2 <.01 0.10 -- Mn 23 0.0 0.07 0.01 26 0.0 0.06 0.01 6 <.01 0.08 0.055 12 <.01 0.15 0.05 Pb 2 <.01 <.01 <.01 2 <.01 <.01 <.01 Se 2 <.001 <.001 <.001 2 <.001 <.001 <.001 v 2 .03 .03 .03 2 .03 .07 .05 Zn 8 <.01 0.02 <.01 14 <.01 0.02 <.01 NOTE: Measurements expressed in mg/1. aTributaries sampled were the following: Pass Creek (N=2), Spring Creek (N=l), Owl Creek (N=3), Little Owl Creek (N=l), Sioux Pass Creek (N=l), Lodge Grass Creek (N=4), Grey Blanket Creek (N=l), and Reno Creek (N=l). I i ' ' ...... "' ...... TABLE 45. SUIIITlary of the physical parameters measured in various tributaries to the little Bighorn River. Owl Creek drainage (Little Owl, Owl, and Sioux Pass creeks near Lodge Grass Creek at Pass Creek ncar Wyola Lodge Grass) Lodge Grass N Min Max Med N r~; n Max Mcd N Min Max 11ed Flow 2 20.8 117 68.9 5 6.5 35.3 17.6 4 6.81 55.4 33.3 Temp 2 0.0 10.0 5.0 5 0.0 10.5 9.3 4 o:o 11.9 2.9 pH 2 8. 3 8.4 8.35 5 8. 3 a. 5 8. 3 4 a. 1 8.5 8. 35 sc 2 601 1023 al2 5 769 1156 970 4 a43 15aa 1121 TDS 2 494 856 675 5 648 a29 791 4 659 1297 911 Turb 2 30 53 42 5 3 60 34 4 2 13 6 TSS 2 82 226 154 5 a.6 182 87 3 6.0 28.5 7.0 DO I .. . . 9. 7 5 9.3 12.2 10.6 4 10.2 12.9 12.2 BOD I .. .. 1.5 5 1.7 2. 5 2.3 4 1.1 2.9 2.2 rc 2 4 580 292 5 18 600 30 4 0 30 8 Ca 2 67 83 75 5 58 86 68 4 92 119 105 11g 2 27 37 32 5 41 76 57 4 38 75 51 TH 2 280 359 320 5 313 507 400 4 385 609 4 71 I Ia 2 24 85 55 5 20 60 53 4 33 144 81 K l .. .. 27 0 . . . . . . 0 . . .. .. SAR 2 0.6 2.0 1.3 5 0.4 1.3 1.3 4 0.7 2.5 1.6 HC0 3 2 278 298 288 5 406 451 429 4 217 338 288 TA 2 234 244 239 5 333 370 357 4 186 287 236 504 2 92 325 209 5 87 204 168 4 238 607 400 Cl 2 1.0 1.4 1.2 5 2.0 3.6 2.4 4 1.2 6.8 3.2 r I . . .. 0.2 0 . . . . . . I . . . . 0.2 N 2 0.0 0.13 0.07 5 0.0 0. 75 0. ll 4 0.0 0.07 0.01 p 2 <.01 0.02 .. 5 <.01 0.07 0.03 4 <.01 0.17 <.01 NOT(: Meosuren1ent~ expressed in rn~J/1. --------------- Minor tributaries (Spring, Grey Blanket, and Reno creeks) N Min Max Med 3 l. 32 5.0 3.0[ 3 8.0 l 3. 3 9.7 3 a.2 8. 7 8.5 3 a37 1414 1036 3 692 1215 a6l 3 <l 7 5 3 2 14.2 6.0 3 11.5 12.6 12.4 3 1.2 3.5 2.2 3 0 55 53 3 ·45 117 70 3 40 76 60 3 360 489 45a 3 13 208 49 0 . . .. . . 3 0.3 4.a 1.0 3 253 637 418 3 208 566 367 3 230 268 238 3 0.2 3.0 0.2 l .. . . 0. l 3 0.0 0.06 0.05 3 ., .01 0.02 0.01 irrigation (typically Class II waters,·tables 15 and 16). Although these streams apparently have a good-to-excellent water quality for application to all stock animals, they do not appear to be suitable as a source of drinking water or public supply because of their high TDS·and total hardness levels. In addition, the salinity levels iu these streams were at levels adequate to influence the aquatic biota (i.e., generally greater than 670 mg/1) and to affect salinity- sensitive crop and forage species. Thus, water quality in the Little Bighorn River tributaries would probably be judged as only fair, primarily degraded by salinity factors; this is true of many prairie streams in eastern Montana. BIGHORN RIVER DRAINAGE BIGHORN RIVER MAINSTEM The Bighorn represents a major river system with an extensive drainage in both Wyoming and Montana; it is the largest tributary to the Yellowstone River. As a resuft of its length, a large portion of the Bighorn's water has traveled considerable distances before it reaches the mainstem. Consequently, it is susceptible to a variety of factors, including reservoirs, tributary inputs, evaporation, and point and nonpoint pollution, which may degrade its initial quality. The Bighorn River originates in Montana as the outlet from Yellowtail Reser- voir, and the potential effect of the reservoir on downstream water quality has been discussed in several papers and reports (Soltero 1971, Soltero et al. 1973). Due to the dam, the current flow regimes and qualities in the river are probably not reflective of its natural condition. A few of these effects are readily apparent in the data summaries prepared for this inventory and will be considered in later sections in this report. Although the annual average flows in the Yellowstone River at Billings are about 44 percent higher than those in the Bighorn at Bighorn (near the Yellow- stone confluence) (USDI 1974), a large part of this excess is due to the spring flood, or the mainstem which is largely absent from the Bighorn due to artificial regulation. Median flows during the May-to-July period, as tabulated for this inventory, were about 222 percent higher in the Yellowstone at Billings than in the Bighorn at its mouth for the same period (a 3. 22-fo 1 d difference). In turn, during the November-March 1 ow-flow peri ads in the Ye 11 ows tone, median B.i ghorn flows were actually 13 percent to 18 percent higher than those in the mainstem at Billings (table 31). As noted, the Bighorn would tend to have a relatively poor water quality due to its drainage length. Given the high flows of this stream, it therefore has the potential to exert a significant influence on Yellowstone mainstem quality. Due to the flow relationships described above, this influence should be strongest during the late summer, winter, and early spring when Yellowstone flows are at their minimum. Water quality data are available from three stations on the Bighorn River as a part of USGS monitoring programs in the region (table 3). The three sites are equidistant with an upper station at St. Xavier just below the dam, a middle location near Hardin, and a·lower site near the river's mouth at Bighorn. These data have been supplemented by a few WQB collections from various locations on the river. For many of the parameters, the data from the uppermost site (table 46) are representative of quality in the entire length of the stream, as 122 .. ...... N w --------------~----- TABLE 46. Surrmary of the physical parameters rreasured in the Bighorn River at St. Xavier. August-October November-February March-Apri 1 May-July N Min Max Med N Min Max Med II Min Max Med N Min Max Med Flow 51 124 5980 3140 53 1722 5580 3890 28 521 6700 4020 47 1670 20,240 5123 Temp 15 9.5 19.5 14.5 17 2.0 12.5 7.0 11 1.0 4.0 3.0 13 4.5 12.5 6.0 pH 39 7 .o 8.2 7.8 46 7.2 8.4 8.0 26 7.3 8. 3 8.0 42 6.6 8.5 7.9 sc 47 515 1090 765 51 657 1150 859 28 788 1160 924 47 576 1100 875 TOS 49 322 788 503 50 441 842 570 27 475 831 625 47 362 790 582 Turb 3 1.2 2.0 2.0 5 2.0 4.0 2.0 2 2.0 3.0 2.5 3 1.4 6.0 2.0 TSS 0 ---- --1 -- --8.0 0 ------1 ----8.0 00 3 9.6 10.8 10.0 5 11.2 12.8 11.4 2 12.8 12.8 12.8 4 10.6 13.2 12. 1 BOO 3 0.7 1.5 0.8 5 0. 7 2.4 1.2 2 0.6 0. 7 0. 7 4 0.7 2.7 1.8 FC 0 ---- -- 1 ----26 0 ------1 ----26 Ca 48 43 92 65 49 56 99 73 27 62 98 81 46 46 96 75 Hg 48 13 32 21 49 20 36 24 27 21 37 27 46 14 34 26 Til 50 160 360 249 53 220 389 286 28 240 394 316 48 180 380 294 Na 48 40 107 66 49 61 118 78 27 59 113 80 46 49 108 80 K 48 1.3 4.3 3.5 49 2.9 5.6 3.8 27 3.0 5.2 3.9 45 1.7 5.1 3.8 SAR 48 1.4 2.5 1.9 49 1.6 2.6 2. 1 27 1.7 2.6 2.0 46 1.5 2.5 2.0 IIC0 3 48 130 224 178 49 180 241 197 27 175 263 216 46 130 252 208 TA 8 115 156 140 10 150 180 162 4 181 198 183 7 162 187 182 504 50 140 362 230 53 190 393 270 28 210 394 286 48 160 362 270 C1 48 3.4 15 8. 5 49 8 15 10 27 6.7 16 11 46 6.6 15 12 F 48 0.1 0. 5 0.4 49 0.3 'o.8 0.4 27 0.4 0.8 0.4 46 0. 2 0.8 0.4 N 50 0.0 0.48 0.21 53 0.0 0.6 0.30 30 O.IJl 0.8 0.29 50 0.02 0.5 0.18 p 25 0.0 0.08 0.03 29 0.0 0.12 0.02 13 0.01 0.08 0.02 21 0.0 0.07 0.02 (.47?) NOTE: Measurements expressed in mg/1. downstream water quality changes did not appear to be as great in the larger river as those in the Little Bighorn. The Bighorn River has a sodium-calcium-sulfate water throughout its length, and magnesium and bicarbonate are secondary ionic constituents. Fluoride, chlor- ide, and potassium were minor constituents (although chloride levels were some- what higher in the Bighorn River than in the Little Bighorn River). The waters in the river were very hard and non-saline, although TDS concentrations were high in comparison to the Little Bighorn and Yellowstone rivers--on the average, 1.43 times higher than the Little Bighorn, 2.64 times higher than the Yellow- stone at Billings, and 1.95 times higher than the Yellowstone at Custer. The upper Bighorn showed a direct linear relationship between flow and TDS; this is generally the opposite of what has been observed in other large streams, and may be a reflection of reservoir influences which were carried downstream to Bighorn. Also, the unusually low TSS and turbidity levels at St. Xavier were probably the result of the reservoir acting as a sediment trap. Dissolved oxygen, BOD, and pH did not indicate water quality problems anyplace on the river, and fecal coli- forms and TSS did not indicate water quality problems in the upper reach. All of these parameters were in accord with state criteria and the state's desig- nation of the upper segment as a B-D1 stream (Montana DHES, undated). Grab sample temperatures were also in accord with this criteria because temperatures were generally less than l9.40C (table 8). Salinity and potential eutrophica- tion therefore appear to be the major water quality problems in the upper reach. The high salinities approach values (670 mg/1) that could affect the aquatic biota, but the B-D 1 designation of the upper reach and its water quality are reinforced by the purported success of trout fisherman in this segment of the Bighorn River. The concentrations of dissolved constituents remained constant throughout the extensive reach of the Bighorn in Montana; the greatest downstream increase was in sulfate (tables 47 and 48). As a result, TDS levels increased only slightly from St. Xavier to Bighorn (less than ll percent). This suggests that due to their low flows or to their nearly equal salinity concentrations, the various Montana tributaries did not affect the river's salinity levels much. On the basis of these major parameters, the water in the Bighorn is expected to be excellent for the watering of all stock but unsuitable for municipal supply as a result of the high TDS and sulfate levels (table 9). Due to the high calcium- magnesium concentrations, the Bighorn has low SAR values and a low sodium hazard for irrigation; however, it has a high salinity hazard and is probably a Class II water that should be used with care in the irrigation of certain plants. The river's TSS levels increased downstream below St. Xavier. Like the Little Bighorn, a spring sediment pulse is also evident in the Bighorn at Big- horn, probably a reflection of tributary inputs with their early spring runoff periods. As a result of the increase in TSS, the value of the stream's fishery would be expected to decline downstream. Using the index defined previously, the upstream fishery would be excellent (having turbidities less than 8 JTU) but would then become a fair fishery near its mouth, with an annual median TSS concentration of 120 mg/1 (European Inland Fisheries Advisory Commission 1965). This is in accord with the state's classification chan~e of the river from a B-Dl in the upper reach to a B-D2 stream below Hardin (Karp et al. lg76a). Med1an and maximum grab sample temperatures increased towards Bighorn during the March-to-October period--also in accord with the classification change. 1?.4 ..... N <.n ·---------------------------------~~-------------------------- TABLE 47. Su~ry of the physical parameters measured tn the Bighorn River near Hardin. August-October November-February March-Apri 1 May-July rl Min Max Med rl Min Max Med N Min Max fled N Min ~lax Med Flow 13 1600 5020 2960 16 2900 5200 3850 9 500 6550 4820 14 1500 8000 4420 Temp 13 10.8 21.0 15. 3 16 0.0 10.0 3.0 10 0.0 7.0 4.0 14 0.5 18.0 11.8 pH 10 7.6 8. 7 8. 3 12 6.9 8.4 8.0 7 7.8 8.30 8.0 11 7. 1 8.20 8.0 sc 11 560 1000 840 14 740 1160 875 7 770 1100 900 10 750 1110 885 TDS 12 362 722 580 16 514 691 632 9 538 952 689 13 472 787 637 Turb 0 ---- -- 0 -- -- -- 1 -- -- 4 0 -- ---- TSS 0 ---- --0 ------1 ----14.8 0 -- ---- DO 10 8. 2 12.6 9.2 12 10.4 15.0 12.0 7 11.2 13.2 12.4 II 9.1 12.8 11.0 BOD 10 1.2 3.3 1.8 12 0.7 3.2 1.5 7 0.9 2.5 1.2 11 1.1 2.8 1. 5 FC 10 1 490 IOD 10 0 130 8 7 D 27D 12 6 41 7700 142 Ca 13 32 79 64 12 57 79 73 7 71 87 78 11 42 86 69 M9 10 15 2.7 22 12 20 26 24 7 23 29 27 11 19 31 26 TH 10 140 310 250 12 230 300 280 7 270 340 300 11 180 340 280 Na 4 51 79 65 4 69 77 73 3 76 82 79 5 60 99 80 K 0 -- ----0 ------0 ------0 ------ SAR 4 1.5 2.0 1.8 4 1 '8 2.1 1.9 2 1.9 2.0 2.0 5 1.7 2.3 2.0 HC0 3 0 ------0 ------I -- -- 205 0 -- ---- TA 4 108 166 131 4 152 172 165 3 168 193 176 5 149 185 166 so. 10 150 310 239 15 230 332 280 9 260 440 303 13 200 370 276 C1 12 4.8 12 7. 9 16 3.4 12 10 9 9.4 14 12 13 7.0 14 12 F 4 0.4 0.7 0.4 4 0.4 0.6 0.4 2 0.4 0.6 0.5 5 0.3 0.6 0.4 N 11 0.13 0.60 0. 30 13 0.10 0.60 0.38 8 0.21 0.50 0.28 11 0.02 0.40 0.18 p 11 0.02 0.25 0.08 12 0.01 0.26 0.06 8 0.04 0.50 0.08 11 0.0 0.21 0.1 (I .01) NOTE: Measurements expressed in mg/1. ..... "' "' TABLE 48. Summary of the physical parameters measured in the Bighorn River at Bighorn. August·October November-February March-April N Min Max Med N Min Max Med N Min Max flow 50 860 5970 3296 64 706 6500 3770 36 685 8520 Temp 23 7.0 21.0 16 28 0.0 8. 5 2.0 17 1.5 10.5 pH 44 7. 1 8.8 7.8 59 7.4 8.6 8.0 34 7.3 8.5 sc 44 580 1160 855 60 740 1180 911 34 555 1210 TOS 42 365 836 555 57 516 854 621 33 362 862 Turb 5 3 20 10 8 3 30 8 4 18 120 TSS 16 14 288 80 14 15 973 40 15 35 1450 00 8 7.6 10.5 8.9 8 10. 1 13.2 12.3 6 10.5 11.8 BOD 3 0.9 1.7 1.2 2 2.5 5. 1 3.8 4 1.6 2.4 FC 4 30 2520 89 6 21 170 25 4 3 41 Ca 25 48 96 65 32 64 98 75 21 42 92 Mg 29 16 34 24 33 16 39 26 24 16 47 TH 43 190 384 273 59 250 402 300 33 171 415 Na 44 46 118 74 60 69 120 83 33 52 123 K 28 2.5 4.7 3. 4 31 2.3 4.7 3.6 23 1.4 5.6 SAR 44 1.5 2.6 2.0 59 1.8 2.6 2.0 33 1.6 2.7 HC0 3 44 106 233 186 59 183 256 211 33 132 279 TA 6 127 161 153 8 157 194 166 3 184 197 504 44 160 400 264 60 206 397 287 32 164 431 Cl 28 5.0 15 8 33 6.0 19 11 23 3.5 14 F 28 0.2 1.0 0.4 31 0.3 0.6 0.4 22 0. 3 0.6 u 23 0.0 0.53 0.20 30 0.0 0.43 0.3 22 0.07 0.45 p 12 0.0 0. 14 0.05 15 0.0 0.07 0.01 11 0.01 0.33 UOTE: Measurements expressed in mg/1. May-July Med II Min Max Med 4325 57 820 23,000 5610 4.8 29 . 0.6 21.7 15.5 8.1 51 7.4 8.53 7.9 950 51 599 1090 899 666 49 371 848 619 62 8 11 260 75 114 28 39.2 6460 342 11.0 11 7.8 11.7 9.0 1.8 6 1.0 5.1 2.2 16 1 25 310 80 82 25 58 91 76 31 26 22 41 27 332 49 224 400 316 86 49 33 120 81 4.2 24 2.6 6.1 3.7 2. 1 49 0.9 2.7 2.0 226 49 152 256 217 189 1 153 210 176 300 49 150 450 285 12 26 7.4 14 10 0. 5 25 0.2 0.8 0.4 0.23 24 0.01 0.41 3.22 0.02 17 0.0 o.2u 0.02 The warm winter temperatures in the river at St. Xavier (table 46) and the sub- sequent declines of winter temperatures downstream to Bighorn (tables 47 and 48) probably reflect reservoir influences. Fecal coliform concentrations also tended to be higher in the lower river, but the state's criteria for average and grab sample concentrations in B-D 2 streams were violated in only a few instances. Eutrophication may be a problem in the Bighorn River, but it is most obvious in the middle segment of the stream near Hardin. Of the various streams inven- toried, this type of problem is most likely to occur in the Bighorn River. As observed on the Yellowstone, a distinct seasonal nitrogen cycle also became evi- dent in the Bighorn River wherein nitrogen (N) levels were typically highest during the dormant winter and early spring seasons and lowest during the warmer, late spring-to-fall periods when biological activity would be at its highest. Distinct seasonal alternations were not evident in the phosphorus (P) data. At St. Xavier, both median N and P concentrations were below their reference cri- teria (table 46). ·However, eutrophic potential increased to Hardin where median P levels exceeded 0.05 mg/1 during all seasons (table 47). In addition, median N concentrations at this location were very-close to their reference ·level, especially during the critical summer period. Since median ammonia concentrations in the Bighorn ranged between 0.05 mg/1 and 0.10 mg/1 (table 49), total inorganic N concentrations in the stream might have been at levels high enough to exceed theN criteria (0.35 mg/1) for a large percentage of the time during the August- to-April period. Thus, eutrophy would be indicated when both P and N often ex- ceed these nutrient standards, demonstrated by extensive algal growths or "moss" in the middle river near Hardin. However, eutrophic potential appears to decline downstream below Hardin to Bighorn due to the decline in median P levels (table 48). The river is probably more P-than N-limited at St. Xavier, with a lower probability of eutrophy than near Hardin where the river is most likely nitrogen-limited. Also, the river is probably more P-limited near its mouth with a lower probability of eutrophy than indicated at Hardin. However, median N and P concentrations in the Bighorn were well below the reference criteria used by the EPA (USEPA 1974b). Data for the minor constituents and trace elements in the Bighorn River are summarized in table 49. Silica concentrations were below the national average for surface waters, and all metal concentrations were generally very low in the upper river and did not indicate water quality problems. This was also true of the river at Bighorn, although the metals tended to increase in concentration downstream. The trace elements would not be expected to detract from any water uses, with the possible exception of mercury, which was observed at levels approaching 7 ~g/1 in a few samples. The high TR concentrations of iron in the lower river were probably related .to the high sediment levels that were occasion- ally obtained there. High TR levels of Fe were not observed in the upper reach where TSS concentrations were consistently low, and dissolved concentrations of Fe in the river near Bighorn were generally insignificant in all samples. Stron- tium levels were in excess of·the average value for major streams (Durum and Haffty 1963) and did not indicate excessive Sr-90 levels. Minor constituents on the whole did not cause pollution. In general, there was no extensive organic pollution (dissolved oxygen was near saturation and TOC levels were low), no synthetic detergents (1·1BAS values were low), and no ammonia 127 TABLE 49. Sl.ll1!lolry of troJ.ce elCilll!nt and rnlscellaneou~ cnnstllu!•nt contentrations l!'"('.l5<jff?l1 In the Bighorn River. Upper river near St. Hisccllo~ne-ou!. Conn i tuents and Q\<i,solvl!d Hetals " "'' ''" ,.,. Color 61 I 21 5 oo' fecal Strep "'" " 0.0 o.to 0.01 /tll)·N " o.o 0. 59 0.05 " 161 6.0 16 II lot II 1.0 " 4.0 ,, • 0.0 .001 0.0 AI ,, • 0.0 .006 .001 B IJ< .060 '300 .110 .. • o.u 0.0 o.o "" 2 0.0 n.o 0.0 Cd 4 0.0 0.0 0.0 c. 4 o.o .001 0.0 ,, '" • .004 .030 .013 '" .. 0.0 . 210 .010 ,, Ll ... 31 0.0 . 132 .005 ,., • 0.0 .020 .004 "' • 0.0 .010 .003 Pb • 0.0 0.0 0.0 "' ,, 4 0.804 1.070 0.910 v 4 0.0 .0014 .0010 '" 4 .017 . 051 .022 NOT[: Meao;urt'llent'i c•preo;~ed in rNJ/1. 11Pb: <0.01, N•2). Xavier dnd nedr Hardin lou I Recoverable l"etdl s~ " "'' ... ,.,. 3 ~ .001 < .01 < .01 I .. .. .II I .. .. < .01 4 < .001 < .01 < .01 I .. .. .02 6 0.0 < .01 0.0 • ,.;,Ql "-.01 < .01 4 .16 ·" ·" 3 < .001 0.007 < .001 I .. .. . 05 ' .01 .01 . o• I .. .. <.001 I .. .. .04 3 <' 01 0.01 <.01 boo c•prC!!.!.e-d u DercentaqP or 'idturdtion. 128 lower river " Mlscelldr~eous ConHituent!. ar1d Dluolved Metal<; II Min • •• "'' 10 I 12 4 " " 109 100 II ' 1300 66 6 0.04 0.19 Q_JQ 91 •. 0 21 '' 6 5 4.8 II 7.6 5 o.o .002 .002 50 .058 .200 .120 5 0.0 .001 0.0 5 0.0 0.0 0.0 5 0.0 0.0 0.0 5 .001 .003 .002 , 0.0 .360 .030 5 0.0 0.0 0.0 II 0.0 .020 .010 5 .001 .003 .002 5 .QOl .003 .002 5 .002 .020 .010 Bighorn TOld\ Recoverab I e Metal!. II "'" ... "'' I .. .. .BOO 7 <.001 < .01 0.002 6 -:.10 0.46 0. 13 I .. .. ' .01 " 0.0 0.02 ' 01 6 ... 01 o.oa ' 05 7 0.0 0.05 ' 01 " <.01 0.05 0.01 " .01 8.2 -" 12 o.o 0.007 < .0002 I .. .. .04 13 .02 -" .05 II < 01 0.100 ,.;,100 ' ' .001 0.00~ 0.002 3 .36 2 I .52 3 < .01 '' 10 (. 10 14 < .01 0 05 0.02 toxicity (un-ionized ammonia concentrations were low given the median total- NHJ and pH levels of the stream). In addition, municipal wastewater discharges do not appear to have a major effect on the Bighorn River, as the median annual fecal coliform to fecal strep ratio was less than one (FC:FS=O.BO). FC:FS ratios between 0.7 and 1.0 indicate that stream bacteria are derived primarily from animal and soil rather than human'sources (Millipore Corporation 1972). As a final point, the waters of the Bighorn River were uncolored--color was typically less than ten units. As a result, the waters in the river should be aesthetically pleasant unless turbidity or eutrophication occur. BEAUVAIS CREEK In addition to the Little Bighorn River, several other smaller streams (with median flows about 5 cfs to 50 cfs) join the Bighorn River in Montana or have portions of their drainage areas in the state. The USGS has sampled Beauvais Creek, which drains the west central part of the Bighorn drainage be- tween Yellowtail Reservoir and Hardin, for several years as a hydrologic bench- mark station." The USDI (1974) describes this type of station as one that: ... provides hydrologic data for a basin in which the hydrologic regimen will likely be governed solely by natural conditions. Data collected at a benchmark station may be used to separate effects of natural from manmade changes in other basins which have been developed and in which the physiography, climate, and geology are similar to those in the undeveloped benchmark basin. Beauvais Creek provides insight into the natural quality of water in streams that have a prairie, rather than a mountainous, origin. As indicated in table 50, data were sufficient for a ·seasonal classification of this stream's water quality. As might be predicted for a stream that is little affected by man's acti- vities, median BOD 5 levels in Beauvais Creek were consistently low (<1.6 mg/1). However, values in excess of 5 mg/1 and approaching 10 mg/1 were obtained spor- adically, indicating that moderately high background BODs concentrations can occur from natural sources at particular times. Occasionally, high BODs levels have been measured in other streams of the basin in relation to their typically low median concentrations. However, even a BOD 5 of 10 mg/1 is not particularly high in comparison to values that have been obtained in organically polluted streams. As a result, DO concentrations in Beauvais Creek were near saturation (with a median DO saturation of 97 percent), and minimum values were consis- tently above the state's criteria for a B-D stream. Similarly, values of pH were typically within state standards (table 8), and median levels were close to those obtained on other streams possessing an adequate number of readings (approaching a value of B.O units for the entire study area). Also, grab sample temperatures from Beauvais Creek were not outstanding, but the relatively high maximum readings in the summer would indicate that this creek is probably a warm-water fishery--a B-D3 rather than a B-D 1 or B-D2 stream. The direct relationship between flow and suspended sediment and the in- verse relationship between flow and dissolved solids were not as noticeable 129 TABLE SO. Summary of th~ physical parameters measured in Beauvais Creek near St. Xavier (Bighorn River tributary). August-October November-Fehrua ry March-Apri 1 Nay-July II Min ~lax Med N Min Max Med II ~1i n Max Med II Min ~1ax Med Flow 26 3.0 15. 7.9 31 1.5 182. 8.6 15 8.8 169. 22. 24 6.2 254. 27 Temp 23 3.0 22.0 13.0 28 0.0 6.0 0.0 10 0.0 10.0 3.0 20 9.0 20.0 17.3 pH 26 7.4 8.4 8.0 31 6.8 B. 7 7 .B 14 7.4 8.5 8.0 23 7. 1 8.6 7.8 sc 26 1100 1920 1395 31 600 2150 1530 14 580 1490 1160 2~ 930 1500 1170 TDS 26 868 1360 1105 31 433 2020 1160 14 418 1120 830 23 655 1240 903 . Turb 0 ---- -- 0 -- ----0 ------0 ------ TSS 12 32 2400 121 17 37 3380 286 8 84 5940 634 13 104 9870 322 DO 22 7.2 12.0 8.8 28 10.0 12.6 12.0 11 9.8 11.1 11.6 20 7.2 11.0 9.2 BOO 18 0. 3 4.0 1.4 20 0.4 7.7 1.5 10 1.0 10.0 1.5 16 0.2 2.8 1.2 FC 5 29 1600 140 8 13 510 50 3 11 200 100 6 20 1500 145 Ca 26 133 268 225 31 39 380 230 14 45 200 124 23 R3 215 170 Mg 26 31 56 48 31 11 84 52 14 11 48 31 23 23 50 43 TH 26 457 893 750 31 140 1290 770 14 158 700 432 23 305 738 610 II a 26 20 79 36 31 40 130 67 14 43 172 88 23 13 120 43 I ( 193?) K 26 1.8 5.3 3.4 31 2.3 7.4 3.2 14 2.0 5. 9 3. 3 23 2.0 6.5 2. 9 SAR 26 0. 3 1.4 0.6 31 0.6 3.0 1.0 14 0.8 3.8 1.9 23 0.3 3.0 0.8 (3. 9?) HC0 3 26 150 273 191 31 92 319 247 14 95 284 204 23 150 270 224 TA 7 136 224 169 9 80 248 218 4 129 189 142 6 173 221 195 504 26 510 778 656 31 240 1160 680 14 200 670 450 23 330 655 510 C1 26 1.6 6. 2.5 31 1.6 9. 3.8 14 1.6 7.2 3.8 23 1.4 8.0 2.7 F 26 0.0 0.9 0.4 31 0.3 0.7 0.4 14 0.4 1.0 0.5 23 0.0 1.1 0.4 II 24 o.o 0.58 0.02 29 0.0 0.45 0.20 14 0.0 0. 72 0. 11 23 0.0 0.29 0.07 p 26 0.0 0.21 0.05 31 0.01 1.5 0.05 13 0.02 2.2 0.10 23 <.01 0.52 0.05 NOTE: Measurements expressed in mg/1. , in Beauvais Creek as in some of the other streams of the study area. These contradictions were most obvious in the transition from spring to summer, when flows and dissolved solids concentrations increased, but suspended sediment decreased. Like the lower Little Bighorn River, Beauvais Creek also demonstrated a secondary flow peak in the spring, probably reflective of the earlier prairie runoff period. The stream's proportions of sodium, its SAR ratios, and its TSS levels also increased at this time, although its TDS concentrations declined. However, regardless of runoff events, both TDS and TSS concentrations were high in Veauvais Creek during all seasons, suggesting naturally high background levels of these parameters in the Bighorn drainage and in the prairie-type of stream in general. As a result, and on the basis of the common constituents and TSS, Beauvais Creek apparently has a naturally poor water quality in relation to most beneficial uses. The waters tended to be slightly saline, and the TDS, sulfate, and probably the turbidity levels of the stream were for the most part above the recommended standards and permissible criteria for drinking water and public supply (table 9). Although TDS concentrations were less than the reference levels for various stock animals, sulfate concentrations were in excess of the threshold level for stock in nearly 70 percent of the samples. The stream has a low sodium hazard for irrigation (SAR values are low) but probably has a high salinity hazard (Richards 1954), Class II water for this use due to the creek's hi~h specific conductance levels and high sulfate concentrations (tables 15 and 16). Furthermore, these salinity features also suggest a potential to adversely affect the aquatic biota (TDS levels were in excess of 670 mg/1). More important, the high suspended sediment levels would probably degrade the creek's fishery, as the annual median TSS concentration (314 mg/1) indicates a poor class of stream (European Inland Fisheries Advisory Commission 1965). TSS concentrations in excess of 2000 mg/1 were obtained occasionally from the creek during all seasons; these slugs of sediment may also affect the biota. As in most Yellowstone drainage streams, chloride, fluoride, and potassium were insignificant constituents in Beauvais Creek. The waters were calcium sulfate; sodium and magnesium were the secondary cations and bicarbonate was the secondary anion. As a result of the high calcium and magnesium concentra- tions, SAR values were low, but the waters were unusually hard, which would detract from the stream's value as a potential domestic supply. Median phos- phorus levels in Beauvais Creek were equal to or in excess of the reference criteria indicating conditions for eutrophication; however, the waters were nitrogen-limited and therefore non-eutrophic. Less than 12 percent of the samples from Beauvais Creek had both P and N in excess of the corresponding criteria, and none of the samples had both P and N in excess of the EPA's nu- trient standards for eutrophication (USEPA 1974b). Peak nitrogen levels were again obtained during the dormant winter season, declining considerably during the biologically active summer-fall period. The Beauvais Creek data indicate that high phosphorus concentrations, along with the high TSS and TDS levels, are natural features of this drainage area. High natural levels of bacteria, both fecal coliform and fecal strep are also evident in the drainage during all seasons (tables 50 and 51). Median fecal concentrations in Beauvais Creek did not exceed the state's average criteria (Montana DHES, undated), but 18 percent of the grab samples had fecal levels in excess of 400 colonies per 100 ml. This violates the state's 131 TABLE 51. s~ry of trdCe ele.nent and r:~i~cellaneous constituent concentrations measured in tributaries to the BlghOm River. Tributaries to So<lp <~ntj Ve11owt<~11 PC!servoi r Rotten Grass cree~s Total P~coverablf! 14e'tals " "'" "'' '"" Color '" oo' fee a 1 " Ag AI " a a. "' " Co ,, ,, ,, Hg Ll "" l!o N! Pb ,, ,, v '" Strep I ----.001 7 <.001 <,001 <.001 7 ' 01 ' 01 <.01 7 ' 01 4 5 0.18 • ' 001 ' 001 .:.001 ; <.01 o.zs 0.01 7 ".01 0.03 0.01 NOTE: Meo:lsurcl:l!nts are c•prcsscd in mg/1. <lAI]: 0.0, /'l•l. boo elpressed as percenuge of saturation. " "'" "'' "'' l ~.OJ ~.01 ". 01 8 <.001 <.01 <.01 a <.01 0.01 ·:.01 8 .18 9.; 1.5 ; ( .001 ( .001 < .001 • .13 .50 .11 • ".01 ( .01 < .01 a <.01 0.01 o.oz 132 Bea1.1va 1 s Creek Miscellaneous Constituel'lts '"' Dts~olv£>d ~tah<l Total Recoverable ~tals " Min "'' "'' " Min ... , "'' 21 I 48 4 I -- --0.0 " 87 Ill 97 Zl ]4 )100 410 95 ;. a " 14 I ----..-.01 a o.o .500 0.0 I -· --.100 ' o.o 0.0 0.0 4 .001 .02 .002 ll .oao .424 .160 I -· --0.0 I ----0.0 I ----0.0 13 0.0 .003 0.0 4 < .01 0 .oz 0.01 13 o.o .001 0.0 8 o.o 0.0 0.0 ' 0.0 .04 0.0 " Q.O .OZ4 .006 4 <.01 0.08 o.oz 70 o.o .75 .31 4 . 98 14 ' • ' 0.0 0.0002 ' 0001 " o.o .06 . OJ 38 o.o .31 .OJ • ·" '-' ... 10 o.o .018 .002 " o.o .008 .004 13 o.o .017 .002 ' ". 100 <. 100 <.100 I ----.OIZ ' .001 .005 .003 " .37 l. 8 Z. Z5 I ----.0014 14 o.o .o; .02 4 .07 .31 .20 standard (table 8). An annual median FC:FS ratio of 0.26 was obtained in the stream, and this" ... may be taken as strong evidence that pollution derives predominantly or entirely from ... (animal) wastes" (Millipore Corporation 1972). This would be expected given the isolation of Beavais Creek from man's activities. Most of the fecal loads in the Little Bighorn and Bighorn rivers, the Yellowstone River above Laurel, and Owl and Lodge Grass creeks are probably derived from natural sources. A major exception is the Yellowstone River below Billings which has median fecal concentrations at Huntley (table 32) in excess of the 145 colonies per 100 ml obtained from Beauvais Creek; this is probably a result of the municipal wastewater discharges that reach the Yellowstone through the urbanized Laurel-Billings reach of the river (Karp et al. 1976b). The water in Beauvais Creek was generally clear and the median silica con- centration was equal to the national average for surface waters (Davis 1964). The trace elements, except cyanide, barium, lead, and silver, had detectable TR concentrations in at least some samples, and several of the TR values (Fe, Mn, and Zn, and possibly Cd and Cu) suggested potential water quality problems (table 51). As observed in most of the streams, B, Fe, Mn, and Sr were usually high. However, the high TR concentrations were probably related to the high suspended sediment levels of the stream, and dissolved concentrations indicated non-critical levels of most of the trace elements, particularly B, Cd, Cu, Mn, and Zn. Although dissolved strontium concentrations were high, radiochemical analyses did not indicate a problem (USDI 1966-1974b), as dissolved gross beta concentrations (a median of 6.3 PC/1 and a range of 3.5 to 14 PC/1) and dis- solved radium-226 concentrations (a median of 0.08 PC/1 and a range of 0.05 to 0.15 PC/1) were well below the state and NTAC criteria (tables 8 and 9). Dissolved uranium concentrations ranged from 1.2 ~g/1 to 4.6 ~g/1, within the range (0.1 to 10 ~g/1) found in most natural waters (USDI 1970). Of the trace elements, only iron may be a potential water quality problem in Beauvais Creek; concentrations may be too high for the aquatic biota and municipal supply. The median dissolved concentration of iron exceeded the criteria for fresh- water life, and about 68 percent of the samples from Beauvais Creek had dis- solved iron levels in excess of the criteria for the aquatic biota (table 19). The median dissolved concentration of iron was almost equal to the reference criteria and standard for surface water public supply and for drinking water; thus, about 50 percent of the samples from Beauvais Creek had dissolved iron concentrations above these specified levels. However, the high levels of iron in Beauvais Creek are apparently not related to pollution inputs, but rather originate from natural scurces. This suggests that naturally high iron concen- trations may be characteristic of the Yellowstone Basin, particularly in asso- ciation with high suspended sediment concentrations, with the iron derived pri- marily from the prairie streams. Data are also available for various herbicide-pesticide analyses of samples from Beauvais Creek (USDI l966-1974b). Of the 102 individual analyses for 18 parameters only DDT was detected (0.02 ~g/1), and only in a single sample (a detection success of 1.0 percent). Detection of these parameters was more common in the Bighorn River at St. Xavier due to proximity of agricultural activity; 4.2 percent of the analyses provided detectable concentrations. DDT and 2,4-D were detected in single cases with concentrations of 0.08 and 0.04 ~g/ However, the low probability of detecting herbicides and pesticides and their generally low concentrations indicate that they do not cause water quality pro- blems in the Bighorn drainage. 133 OTHER TRIBUTARIES ABOVE HARDIN Some water quality data are available on several other streams in the Big- horn drainage as a result of state WQB sampling programs in the region (Karp and Botz 1975, Slack et al. 1973). These tributaries can be separated into four groups: 1) streams which drain the same general area as Beauvais Creek between Yellowtail Reservoir and Hardin, but on the opposite (eastern) side of the Bighorn River (Soap and Rotten Grass creeks); 2) creeks which drain the mountainous areas around Bighorn Lake in south central Montana and empty directly into the reser- voir; 3) Sage Creek, west of Bighorn Lake and unique in its southerly flow, which joins the Bighorn system in Wyoming; and 4) Tullock Creek, which drains the northeast segment of the Bighorn drainage between Hardin and Bighorn, joining the mainstem very near its mouth. Statistical summaries of the major water quality parameters for the first two groups listed above are presented in table 52. Tullock Creek is discussed in the next section of this report. Date from Beauvais Creek indicate that high concentrations of suspended sediment and dissolved solids probably occur naturally in many of the streams in the Bighorn, and, possibly, the Yellowstone drainages. Thus, as in Beauvais Creek, the high levels of TDS and TSS in Soap and Rotten Grass creeks are pro- bably the result of natural features, although they may be amplified by man's activities. Man's activities may also account for the slightly greater BOD 5 levels in Soap and Rotten Grass creeks over those in Beauvais Creek (table 50). However, neither the BOD 5 concentrations nor the levels of pH, DO, and SAR in Soap and Rotten Grass creeks suggested pollution problems, although fecal coli- form concentrations were high and occasionally exceeded the state recommendation. Several other similarities are evident between Beauvais, Soap, and Rotten Grass creeks, possibly due to the closeness of the respective drainage areas. They all have streams with similar flows tending to have slightly saline, calcium sulfate compositions and extremely hard waters. In all three streams sodium, magnesium, and bicarbonate are secondary-ions and chloride and fluoride · ·-- concentrations are apparently insignificant; SAR ratios are low; waters are non-eutrophic and nitrogen-limited with median phosphorus concentrations very near or greater than reference level; and concentrations of metals are low with the possible exceptions of iron, manganese, and zinc (table 51). The calcium sulfate water in these group 1 streams suggests that gypsum (Caso 4 ) formations may exist in the Yellowtail-Hardin portion of the Bighorn drainage; this is most apparent in Gypsum Creek (table 52). In general, the water quality in Soap and Rotten Grass creeks is poor and poses the same problems for water use as Beauvais Creek. The high TDS and sulfate (and possibly iron) concentrations and the occasionally high turbidi- ties would detract from using the streams as municipal supplies (USDHEW 1962) 134 ,_. w 01 TABLE 52. Surrmary of the physical parameters measured in vario-us tributaries to the Bighorn River. Flow Temp pH sc TDS Turb TSS DO BOD FC Ca Mg TH Na K SAR HC03 TA so4 Cl F N p Tributaries to Yellowtaila Soap Creek near Rotten Grass Creek Reservoir near Fort Smith St. Xavier near St. Xavier N Min Max Med N Min Max Med N Min Max Med 8 0.5Eb 168 23.8 3 12.5 138 15E 4 18 112 20.2 8 6.5 13.0 9.9 3 0.0 3.0 15. 1 5 0.0 11.6 0.5 8 7.90 8.50 8.30 3 7.40 8.50 8.40 5 7.60 8.30 8.20 8 307 23oob 388 3 849 1500 1021 5 843 2020 1536 8 243 2162b 302 2 690 822 756 4 726 1318 1237 7 2 125 7 3 8 80 51 4 19 90 65 8 6 402 25.5 3 22.8 341 178 4 25 996 183 8 9.5 11.8 10.4 3 9.9 13.2 10.5 5 10.3 13. 1 12.2 7 1.3 2.2 2.0 3 1.6 3.2 2.5 5 1.8 4. 1 2.9 7 0 480 0 2 4 610 307 5 20 1980 84 8 44 483b 54 2 84 117 101 4 83 160 142 8 8.9 84 18 2 42 44 43 4 38 83 67 8 152 1552b 205 2 391 467 429 4 362 715 641 8 1.0 21 4.8 2 43 56 50 4 65 124 115 1 ----18 0 ------0 ------ 8 0.0 0.3 0.2 2 0.9 1.1 1.0 4 1.5 2.2 1.7 8 148 234 195 2 257 285 271 4 254 314 285 8 121 198 165 2 224 241 233 4 208 257 233 8 6.6 1392b 34 2 227 334 281 4 283 656 621 8 0.3 15 1.5 2 2.3 7.0 4.7 4 3.4 7.0 6.0 1 ----l.2b 1 ----0.5 1 ----0.4 8 0.0 0.25 0.06 2 0.03 0.04 0.035 4 0.06 0.79 0.14 8 <.01 0.04 <.01 2 0.04 0.04 0.04 4 0.03 0.24 0.10 NOTE: Measurements are expressed in mg/1. aCrooked, Gypsum, Porcupine, Dry Head, Hoodo, Big Bull Elk, Little Bull Elk, and Black Canyon creeks. bData from Gypsum Creek. as would the very hard nature of the water. The high TSS-turbidity and TDS levels may also adversely affect the aquatic biota (European Inland Fisheries Advisory Commission 1965, Ellis 1964); consequently, these streams indicate poor water quality for fishery needs. These creeks have low sodium hazards but high salinity hazards for irri- gation (probably a Class II water) that should be used with care in application to certain crop and forage species (tables 15-17). In addition, although TDS concentrations are indicative of a good class of water for stock animals, sul- fate concentrations in Rotten Grass Creek exceeded the threshold concentration for stock animals (California WQCB 1963}. The Yellowtail tributaries have the best water quality in the Bighorn drainage. This can be shown by ranking the annual median TDS concentrations of the various streams as follows: l) 2) 3} 4) 5) 6) 7) 8) 16l 11) Yellowtail tributaries--about 302 mg/1; upper Little Bighorn River--346 mg/1; Sage Creek--about 464 mg/l; lower Little Bighorn River--470 mg/1; upper Bighorn River--566 mg/1; lower Bighorn River--612 mg/1; middle Bighorn River--630 mg/1; Little Bighorn River tributaries--about 810 mg/1; Soap and Rotten Grass creeks--about 1000 mg/1; Beauvais Creek--1026 mg/1; and Tullock Creek--about 1280 mg/1. Except in the Yellowtail tributaries, Sage Creek, and the Little Bighorn River, water quality in the tributaries is generally poorer than that in the mainstem streams. The effect of Beauvais, Soap, and Rotten Grass creeks on the Bighorn River is evident in the above listing by the increase in mainstem TDS concentrations from St. Xavier to Hardin. The decline in mainstem TDS from Hardin to Bighorn is probably due to dilution from the Little Bighorn River, which joins the Big- horn below the mainstem-Hardin sampling station. The low TSS-turbidity values and low TDS and fecal coliform concentrations in the Yellowtail tributaries (excluding Gypsum Creek) probably result from the mountainous drainages of these streams (the Pryor and Bighorn mountains) and the general lack of an extensive prairie system (USDI 1968). The waters were definitely non-saline, although they were very hard as a result of the high calcium concentrations. Pollution problems were not indicated by DO, pH, and BOD~ values; this is appropriate as the streams are generally removed from man s activities. All of the constituents for which there were data were in accord with state standards (table 8). Consequently, the tributary streams to Yellowtail Reservoir appear to be suitable for all beneficial uses--drinking water and public supply (although softening may be required due to the hard waters}, stock water, and the irrigation of all crop and forage plants (a Class I water}; however, the unsurveyed, mountainous and remote nature of these streams would probably preclude their extensive use by man (USDI 1968}. 13fi The TR concentrations of the metalsin the Yellowtail tributaries were generally low (table 51); thus, the trace elements should not detract from any of the water uses. In addition, these streams should be excellent fish- eries, if no physical barriers are present. The tributary fisheries would probably be cold-water due to the orographic locations of the streams; these creeks have been given a B-D1 designation by the State of Montana (Montana DHES, undated). In contrast to the Bighorn River, the waters in these tri- butaries were non-eutrophic and probably more phosphorus-than nitrogen- limited. Concentrations of all ionic constituents, with the exception of .calcium and bicarbonate, were relatively low in the group two streams. This was most distinct in terms of their low sodium (and SAR) and sulfate levels i'n relation to the higher concentrations of these two ions in the other streams of the Bighorn drainage. The presence of such chemical features would indicate ex- tensive limestone formations in the Bighorn-Pryor Mountains. Although Sage Creek has a different drainage pattern than the other Big- horn tributaries, it originates in the same mountainous area as the western tributaries to Yellowtail Reservoir (Pryor Mountains), and as a result, Sage Creek has a similar type of water as the group two streams (table 53). However, Sage Creek has a more extensive prairie drainage above its sampling location near Warren, contributing to its water quality. Sage Creek also has non-saline and calcium bicarbonate waters which are very hard with low trace element con- centrations, but higher concentrations of TDS and most ionic constituents than the Yellowtail tributaries. Concentrations of sodium and sulfate are particu- larly high. These higher ionic concentrations would not preclude the use of the stream's water for stock or irrigation. That is, Sage Creek may be clas- sified as a Class I water with a low sodium and a medium salinity hazard, al- though its high TDS levels and hardness might give the water a borderline classification for public supply and drinking water. Relatively high TR iron (and possibly manganese) levels were evident in Sage Creek, as in many streams in the Yellowstone Basin. Iron was found in high concentrations in one sample in association with high suspended sediment concentrations. Such high iron and manganese levels may reduce the water's value as municipal supply, but the data were not adequate for a definite assessment of this nature. The water in Sage Creek was non-eutrophic, and DO, pH, BODs, SAR, fecal coliform, and most ionic constituent levels conformed to state criteria where applicable. The relatively high TSS-turbidity levels, therefore, may be the major detractions from the water quality. The high TSS levels in Sage Creek at Warren may be related to its comparatively long prairie segment, a5 in Pryor Creek, and in contrast to the orographic drainage of the Yellowtail tri- butaries. The Montana fishery in Sage Creek is probably cold-water due to its close- ness to the Pryor Mountains. This means that it is classified as a B-D] stream, although the stream would probably provide only a fair fishery due to the high TSS concentrations. 137 TABLE 53. Summary of the physical parameters and total recoverable metals measured in Sage Creek near Warren during the August-October period. Physical Parameters Total Recoverable Metals N Min Max Med N Min Max Med Flow 2 15 62.0 38.5 As 2 <.001 <.001 <.001 Temp 2 4.0 12.0 8.0 Cd 2 <.001 <.001 <.001 pH . 2 8.20 8.40 8.30 Cu 2 <.01 <.01 <.01 sc 2 488 662 575 Fe 2 0.3 4.1 2.2 TDS 2 401 527 464 Hg 1 ----<.001 Turb 2 7 44 26 Mn 2 <.01 0.11 -- TSS 2 22 154 88 Zn 2 <. 01 0.02 -- DO 2 9.3 10.9 10. 1 BOD 2 1.5 1.7 1.6 FC 2 <100 115 -- Ca 2 63 67 65 Mg 2 22 28 25 TH 2 260 272 266 Na 2 1.8 42 22 K 0 ------ SAR 2 0.0 1.1 0.6 HC0 3 2 212 248 230 TA 2 174 212 193 so4 2 56 173 115 Cl 2 0.1 9.0 4.6 F 0 ---- -- N 2 0.15 0.01 0.08 p 2 <.01 0.05 -- NOTE: Measurements are expressed in mg/1. 138 TULLOCK CREEK Tullock Creek is the most northern tributary of the Bighorn River (USDI 1968), and as a result, has an extensive prairie drainage. This is reflected in the type of water in the creek and in its quality. As suggested previously, Tullock Creek probably has the poorest water quality in the Bighorn drainage. Some water quality data are available from the state WQB for an upper site on the stream and for a lower station near its mouth (table 6). The upstream data were insufficient for a seasonal or flow-related classification; data from the lower location were adequate for a separation based on flow, as seen in table 54. The chemical composition of water in Tullock Creek was generally different from that in other streams in the Bighorn system. Upstream, the waters were sodium bicarbonate in nature, with sulfate the secondary ionic constituent. Downstream at low flows, the waters became sodium sulfate in character, which is characteristic of many prairie streams. ·However, at high flows the creek in its lower reach retained its sodium bicarbonate type of water--probably a reflection of upstream influences being carried downstream during the periods of high discharge. Calcium and magnesium are the secondary cations in Tullock Creek. The greater magnesium over calcium concentrations, particularly noticeable on an equivalence basis, differed from the other streams inventoried, which had greater calcium over magnesium concentrations. As in most streams in the Yellowstone Basin, chloride and fluoride concentrations were insignificant in Tullock Creek. Median values of pH and BODs were slightly higher in Tullock Creek than those established for other streams in the study area--higher than the median pH approaching 8.0 units and higher than the median BOD 5 which was generally less than 3.0 mg/1. However, Tullock Creek is a B-D 2 stream, and its pH values were ~ithin the state criteria for this designation (table 8). In addition, its BOD 5 levels, though comparatively high, did not suggest that too much organic pollution was reaching the stream. As suggested by the Beauvais Creek data, sporadically high BODs levels in excess of 4 mg/1 and approaching 10 mg/1 might be expected as a natural occurrence. The stream's DO concentrations were greater than the state's ·minimum cri- teria for a B-D? stream; a few samples, however, demonstrated DO values slight- ly less than th1s recommendation (7 mg/1). This fact, and the hi~h maximum summer temperatures obtained from the stream (greater than l9.4°C) indicate that it would be more appropriate to classify Tullock Creek a B-D3 stream in- stead of a B-D2 stream. This is probably true of many of the small lowland streams in the Bighorn drainage. Fecal coliform concentrations tended to increase downstream in Tullock Creek, and occasional grab sample concentrations at the lower site exceeded the state recommendation; however, the median levels of fecals were less than the state's average criteria. Also, trace element concentrations appeared to be high (except As, Cd, Hg, and Pb) in Tullock Creek (table 54). This was true of iron and manganese, but, after studying the matter, TR concentrations of B, Co, Cr, Li, and V do not appear to be critical levels in relation to 139 -.;. 0 rlow T~mp pH sc Ill~ Tur·IJ T5S orr 000 rc (a fig Trr !Ia r. SMl IIC0 3 !A so, Cl r N p Upper TuJI(JC~-(r1:•~~-ruJlod Creek rr /lin ~~.1 • r-~"d :r 3 I. [ (5.5 7•1.1 7 "I 0.0 17.7 n.o 6 3 7.90 R.P.O H.t.O 7 3 1 1 f~ I) 12/0 1?26 7 3 943 lORI 960 6 3 27 .... 1 3~ 7 2 3R 118 78 6 3 R.O II .r, 1\. s 5 3 4.4 4, 9 4.9 5 2 0 5 3 5 3 32 41 3·1 7 3 39 62 4) 7 3 245 359 256 6 3 170 res 184 7 0 --:l I --4 3 4.2 5: 1 4.6 6 3 382 514 421 7 3 313 506 351 6 3 230 323 267 7 3 4.0 4.5 4. 1 7 0 ------6 3 0.02 0.52 0. 32 6 3 0.02 0.13 0.04 7 NOTE: Hra~urerr:elltS arc expressed in mg/1 . • less than 8.0 cfs. bGreater than 8.0 cfs 1 • I cae: -:.01, N=l; Se: ~!.oo1. N=l. I f-iin 0.0 0.0 I. 70 (}(_12 ~~6 13 30.11 4.1! 1.4 II 33 20 197 71 3. 0 2. 1 179 149 220 3.8 0.3 0.01 0.01 n~.lr- 1·1,1 ( 7. u 21.6 H.69 ?.P.flll 2·115 42 91.6 9.>l 5.11 50{1 Ul 77 521 536 7.0 11.4 645 529 1070 21 0.5 0.62 0.10 - fliqhorn ,, Tullock Crt~,!~: nr~r1 r Bi(jhorn l> lotid n:covl'r.JlJ!e mctalsc r-~~! 11 rl f1 in t·Ll•. t-h~d II i1 in f·\;} ~-Mcd 2. [ 7 IR •1H1 30.1 ,,, 5 <.01 <.01 <.01 ( .007) 10.6 7 0. 2 I~~-0 4.5 8 7 <.I 0 0. lr. 0.10 11.25 7 7.00 R.RO s. 31 Cd 14 "'.001 0.01 <.001 2107 7 236 2422 911 Co 1 ----.03 1651 6 196 1971 1221 Cr 3 < .01 0.02 0.01 30 7 21 ·IRS 85 Cu 14 .... 01 0.05 0.01 5B.4 7 80.!> 9110 164 rc 14 .47 11 1.5 R. 2 6 7' 7 11.9 9.8 llg 3 <.001 ., .001 ,. '001 3.1 6 2.1 :> 11 ·1. 6 L i I ----.OJ 34 4 0 690 151 f·ln I 3 .04 1.4 . 11 54 7 17 57 37 Pb 3 <.01 <.01 <.01 62 7 B. 3 73 37 v I ----.03 380 7 79 ·133 245 Zn 14 <.01 0.06 0.01 345 7 18 450 200 6.0 7 4.5 7' 7 6.9 7.6 7 0.9 9.7 5.6 566 7 93 686 412 462 7 76 589 346 6t.O 7 20 735 312 10.0 7 0.4 14 4.8 0. 4 4 0.1 0.3 0. 2 0.17 7 0.02 0. 34 0.10 0.02 7 0.02 0.49 0.05 I various reference criteria. Table 51 shows that seven to ten percent of the TR and dissolved concentrations of Fe, Mn, and Zn in Beauvais Creek were present in the dissolved form. Thus, the dissolved metals concentrations, including those of Fe, Mn, and Zn in Tullock Creek (and also in Rotten Grass, Soap, and Sage creeks) do not appear to cause water quality problems because the calcu- lated dissolved concentrations would be lower than the corresponding reference criteria. Major features that degrade Tullock Creek's quality apparently are its high dissolved and suspended solids concentrations. Suspended sediment levels in Tullock Creek were relatively high throughout the stream and were directly related to flow. Dissolved solids concentrations were also high, but they tended to increase downstream at a level of 26 percent at similar flows, and they were negatively correslated with discharge. The waters were typically slightly saline and very hard; these features together with the h1gh sulfate concentrations would generally eliminate the creek as a source for domestic supply. Turbidities also often exceeded the permissible criteria for surface water public supply. Although the stream may be considered a good source of stock water on the basis of TDS levels, the high sulfate and bicarbonate con- centrations of the creek occasionally exceeded the threshold and limiting levels of these parameters (tables 10-14) at all locations and flow regimes. Most common near the stream's mouth during periods of low discharge, this would· re- duce the value of the creek as a source of water for domestic animals. In turn, the high TDS and TSS concentrations, particularly in the downstream reach at low flows, would be expected to have a detrimental effect on the stream's biota. On the basis of overall TSS concentrations, .the stream would probably support a poor fishery. Tullock Creek appears ·to have the poorest water quality for irrigation of any of the streams analyzed. It has a high salinity hazard and a medium sodium hazard for this use (USDA 1954) in contrast to the low sodium hazards observed in other streams of the Bighorn drainage. With high sulfate, sodium, SAR, and specific conductance-TDS levels in the stream, Tullock Creek definitely has a Class II water for irrigation (tables 15 and 16) that should be used with caution when applied to some crop and forage species. YELLOWSTONE MAINSTEM YELLOWSTONE RIVER BIGHORN RIVER TO POWDER RIVER This is an extensive reach of the Yellowstone River that receives water from numerous small prairie tributaries of potentially poor quality and from several large tributaries, including the Bighorn River. The larger tributaries, such as the Bighorn, would be expected to affect the water quality of the Yel- lowstone mainstem, and cumulative effects would be expected from the smaller streams. Several water qual1ty trends and problems are evident in the mainstem above Custer. Some water quality trends observed on the Yellowstone River above Custer are summarized as follows: 11! 1 1) There is an inverse relationship between TDS concentrations and flow, with salinity increasing downstream. This is due primarily to increasing sodium, sulfate, calcium (and total hardness), and bicarbonate levels. 2) Magnesium, potassium, chloride, and fluoride are minor con- stituents in the river above Custer and lack distinct changes in concentration downstream. 3) The water is calcium bicarbonate with increasing proportions of sodium and sulfate and generally lower Ca:~1g and HC03:S04 ratios downstream. 4) Values of pH tend to be lower at high flows and upstream with the reduced alkalinities. · 5) There exists a tendency towards a greater, but apparently non-critical, organic loading in the river below Billings. 6) Temperatures become warmer below Big Timber. 7) A direct relationship has been observed between TSS-turbidity and flow, the levels of which generally increase downstream to Custer. B) Metals concentrations increase downstream, as shown by the TR and dissolved levels of Fe, Mn, and Sr. g) A spring-summer, March-July pulse of high phosphorus concen- trations occurs with a downstream increase in phosphorus during the winter and summer. 10) Non-eutrophic conditions prevail due to a nitrogen limita- tion, although the river tends to become more eutrophic downstream. 11) Peak nitrogen concentrations occur during the winter and low levels during the summer. 12) Pesticide-herbicide detection is more successful downstream. ·Potential water quality problems in the Yellowstone above Custer might be listed as follows: 1) The river has relatively high fluoride concentrations above Livingston, possibly detracting from the stream's use for stock water and irrigation. 2) High phenol and fecal coliform concentrations occur below Laurel. 3) High TSS-turbidity and TDS concentrations develop downstream. 142 4) Arsenic and mercury concentrations are potentially high. 5) Eutrophy.may occur downstream near Custer. Ammonia may be a eutrophic element in the Laurel-to-Custer reach of the river, as the stream is nitrogen-limited. Water quality data on the Bighorn River-to-Powder River reach of the Yellowstone River are available from the USGS for three locations. In down- stream order, they are at Myers below the Bighorn River, at Forsyth above Rosebud Creek and at Miles City above the Tongue River. The USGS site at Terry in the subsequent study segment lies below the confluence of the Tongue and Powder rivers and may be expected to show the effects of these tributaries on the mainstem (USDI 1968). The site at Miles City is probably most representative of the river's quality in the Bighorn-to-Powder reach due to the longer period of collection (table 3). Stations at Billings and near Livingston also gave more accurate information for their reaches for the same reason. Thus, inter-reach water quality comparisons are probably most valid when made between the Livingston, Billings, and Miles City locations. The USGS data for the Bighorn-to-Powder reach were supplemented by information collected by the state WQB as a part of various sampling programs (Karp and Botz 1975, Montana DNRC 1974, Peterman and Knudson 1975). Closely related state WQB sites on the river were com- bined to correspond to the three USGS locations (Myers, Forsyth, and Miles City); this accounts for the modifications of the USGS site designations in the water quality tables of this report (tables 55-57) for major parameters. An inverse relationship between flow and TDS concentrations was evident in the Bighorn-to-Powder segment of the Yellowstone River. A two-fold increase in TDS was observed from the May-July runoff period to the low-flow winter- spring seasons. However, this relationship was not as obvious throughout the entire year in the Bighorn-to-Powder reach as it was upstream. Above Custer, median TDS concentrations increased from the May-July period to the winter season, and concentrations in the winter and spring (March-April) were then closely equivalent. Only a 17 mg/1 or 6.6 percent difference in TDS was ob- tained between the May-July-to-winter and the winter-to spring periods (a 6.2 percent average difference in specific conductance). Median flows decreased from the runoff period to the winter with flows during the winter and spring seasons also closely equivalent, i.e., a 338 cfs or 5.5 percent average dif- ference between these seasons. In contrast, in the Yellowstone below Custer, median TDS levels consistently increased from the runoff period through the spring phase, averaging 62 mg/1 or 13.1 percent higher in the spring than in the winter. However, median flows also increased dramatically from the winter to the spring, averaging 2917 cfs or 38.5 percent higher during the latter season. This secondary peak in flows during the spring, along with the increase in TDS concentrations, is probably a reflection of inputs to the Bighorn-to- Powder segment from prairie streams which have an earlier runoff period and a relatively poor water quality; this, in turn produces a direct relationship between flow and TDS for a portion of the year in the lower river. Salinity in the Yellowstone River, as measured by total dissolved solids or specific conductance, was found to increase downstream from Corwin Springs 143 -... ... TABLE 55. Surrrnary of the physical parameters measured in the Yellowstone River at Myers. August-Octobt?r November-February March-Apri 1 rl Min Hax Med N Min flax fled N Min r~ax Flow 7 8100 14,500 9620 7 7000 10,000 7680 7 8000 14.700 Temp 7 10.5 21.0 15.0 8 0.0 5.5 1.1 8 2.2 13.1 pH 7 8.0 8.7 8. 3 8 7.7 8.4 8.4 8 8.00 8.35 sc 7 431 750 520 8 640 760 727 8 6!8 789 TDS 6 279 . 397 369 7 410 565 470 8 395 616 Turb 4 5 25 10 4 4 59 12 5 22 340 TSS 3 13 100 16.8 2 22 94 58 6 50 126 DO 7 7.6 10.6 9.3 8 11.4 !3.0 12.2 8 10.0 12.4 BOD 3 0.8 2.0 1.7 2 2".0 3.8 2.9 7 1.5 4.3 FC I ----3500 2 58 70 64 4 9 64 Ca 6 39 53 45 7 55 66 64 8 53 70 Mg 7 14 21 20 8 19 27 21 8 19 30 TH 6 156 220 180 7 220 269 240 8 210 300 Na 6 36 51 42 7 50 62 58 8 48 76 K 6 2. 7 3.8 3. I 6 3.2 5.0 3.3 6 1.9 4.2 SAR 6 1.2 1.6 1.4 7 1.4 1.7 1.6 8 1.4 2.0 IIC0 3 7 142 188 162 7 174 197 195 8 166 207 TA 7 116 154 !38 7 143 162 160 8 136 170 504 6 95 160 !33 7 170 210 200 8 170 260 C! 6 5.6 9 6.5 7 8 10 9.3 8 7.6 12 F 6 0.3 0.4 0. 4 6 0.4 0.4 0.4 6 0.4 0.7 rl 6 0.06 0. 31 0 .I 7 0.2 0. 72 0. 34 7 0.!4 0.7 p G 0.01 0.07 0.04 7 u.u 0.0~ 0.0] u U.IJ£ 0. JU NOTE: Meilsurenll!nts e,xpresscd in mg/ I. Hay-July Med N Min Max Med 12,360 9 12,000 57,200 33,500 3.8 10 10.0 23.5 14.3 8.2 12 7.78 8.4 7.94 735 . 12 265 764 438 540 12 !56 620 292 27 9 24 200 85 71 7 63 534 348 10.8 12 5.8 11.3 8.8 2.5 9 0.9 5.6 2.8 26 4 90 >10 4 3!5 65 12 24 65 38 25 12 7.2 26 13 264 12 90 268 !46 65 12 16 70 3Z 3.6 10 1.6 3.9 2.5 1.8 12 0.7 1.9 1.1 !94 12 88 209 !30 !59 12 72 171 121 224 12 49 237 96 10 12 2.6 9.5 5.5 0.5 12 0.2 0.6 0.4 0.28 10 0.09 0.4 0.22 0.05 9 0.03 0.54 O.IH TABLE 56. Summary of the physical parameters measured in the Yellowstone River near Forsyth. August-October Novemb£!r-February March-Apri 1 May-July N Min Max 11ed N Hin Max Med N Min Max Med N Min Max Med . -- Flow 7 7900 14,500 9480 8 7000 9970 7550 8 7740 14,800 9980 11 10,800 61 ,800 33,800 Temp 7 10.5 22.3 15.0 9 0.0 4.5 1.0 9 5.6 14.4 6.5 13 10.0 22.7 16.0 pH 8 8.0 8.5 8. 5 9 7.4 8.5 8.3 9 8.1 8.6 8.2 13 7.6 8. 5 8.12 sc 8 450 760 565 9 610 755 740 9 580 859 735 13 245 500 435 TOS 7 296 486 367 7 417 548 467 9 362 668 560 13 145 357 254 Turb 4 5 48 9 4 4 66 16 6 3 140 22 10 25 320 Ill TSS 3 12 135 32 3 8.8 54 28 7 10 155 38 9 122 992 363 00 7 7. 7 11.0 8.8 9 11.0 13.1 12.4 9 9. 3 12.3 10.8 12 7.3 10.6 8.5 BOD 3 0. 7 2.4 1.7 3 2.6 4.6 3.8 7 1.8 3.3 2.1 8 0.6 4.8 2.4 FC 1 ----7900 3 1 52 20 5 D 130 10 5 9 855 315 Ca 7 39 55 45 7 54 64 62 9 49 74 67 13 23 50 33 ~\g 8 14 21 18 8 18 25 22 9 17 29 25 13 4.2 17 11 TH 7 154 220 190 7 208 260 250 9 190 300 270 13 33 180 120 Na 7 37 58 49 7 52 62 55 9 43 81 69 13 16 80 29 K 7 2.7 3.4 3.1 6 3.1 4.8 3.3 4 2.9 4.3 4.2 8 1.7 3.2 2.4 SAR 7 1.3 1.7 1.5 7 1.5 1.7 1.6 9 1.4 2. 1 1.9 13 0.8 2.6 1.1 HC0 3 8 138 185 165 7 151 200 195 9 162 203 193 13 87 169 115 TA 8 117 152 141 6 152 164 160 10 124 174 168 13 71 139 95 504 7 110 172 150 7 170 210 190 9 150 273 220 13 44 190 88 Cl 7 5.1 9 6.5 7 7.0 11 9 9 6.8 12 9.6 13 3 7 4.9 F 7 0.3 0. 5 0.4 6 0.4. 0.4 0.4 6 0. 5 0.7 0.5 11 0.2 0.4 0.3 " 7 0.06 0.21 0.1 7 0.3 0.47 0.4 8 0.07 0.4 0.16 13 0.04 0.40 0.19 p 7 0.01 0.16 0.05 7 0.0 0.04 0.03 9 0.02 0. 33 0.04 13 0.02 0.55 0.12 NOTE: f'easurements expressed in mg/1. TABlE 57. Sur;Jnary of the physical parameters measured in the Yellm.,stone River near Miles City. August-October November-February r~arch-Apri l May-July :: Hin ~lax fled r: Min Max fled r: r·1in r·lax l·led r: Min Max r1ed flow 36 6160 19,000 9115 37 4200 33,700 7490 25 57RO 22,000 9130 39 9030 66,000 26,200 Temp 19 B. 5 23.2 16.5 21 0.0 6.5 1.0 15 0.0 17.0 2.0 23 9.5 24.7 15.0 pH 32 7.2 B.7 8.1 39 7.0 B. 5 B. 1 26 7.4 8. 7 7. 9 44 6.B B.5 7.9 sc 35 430 724 600 39 391 913 740 28 5Bl 926 760 46 245 B70 410 TOS 34 272 523 391 37 254 615 4B2 27 3B5 638 506 46 150 . 648 258 Turb 12 2 50 12 15 3 200 9 12 4 200 36 20 24 BOO 142 TSS 6 13 liB 31. 7 3 39 lBO 62 8 10 421 77.5 13 121 1140 456 00 14 7.6 11.6 9. I 15 11. 1 l3.B 12.6 II B.O 12.3 11.1 20 7.4 I 0.1 B.B BOO 3 0. 9 2.8 1.6 2 3.8 B.3 6. I 6 1.4 4.8 2.3 9 0.5 5. 1 1.9 FC 11 0 13,400 9 11 0 1200 7 II 0 300 12 16 7 2100 385 Ca 29 36 59 50 34 37 73 61 24 46 72 65 43 23 58 3B Mg 29 13 23 18 34 10 29 22 24 16 30 25 43 7.0 25 12 TH 30 120 241 201 33 130 286 246 25 1B2 292 260 43 B6 246 1~0 Na 29 34 71 52 34 37 73 61 24 50 BO 66 43 15 75 30 K 27 2. I 4.B 3.4 33 2.B 5. 3 3.B 22 2. 9 5.5 4.1 38 1.5 4. 9 2.6 SAR 30 1.2 2.0 1.6 33 1.1 2.4 1. 7 25 1.5 2.1 l.B 43 0.7 2.4 1.1 11[03 30 142 196 174 34 13B 220 193 24 149 213 196 44 B3 204 123 TA 9 117 157 151 10 127 175 157 6 122 169 160 9 BB 134 94 504 29 100 210 160 34 100 2B9 201 24 146 266 224 42 46 200 94 Cl 29 5.3 10 7.9 33 4.3 12 9.6 25 2.9 14 10 43 2.2 9.5 5.5 f 27 0.3 0.9 0.4 33 0.3 0.6 0.4 23 0. 3 0. 7 0.5 41 0.0 0. 9 0. 3 " 33 o.o 0.98 0.06 3B 0.0 0. 71 0.30 29 0.0 0.6 0.23 4B 0.0 1.1 0.10 p 26 0.0 0.16 0.04 30 0.0 0.13 0.03 19 0.01 0.40 0.04 2B 0.03 1.6 0.11 tlOTE: l'leasurcments expressed in lll!.J/1. to Custer. This trend was also evident in the Bighorn-to-Powder reach of the river, but it was most obvious and consistent between the Custer and Nyers sampling locations around the confluence of the Bighorn River. Below Myers, salinity increases downstream were relatively small. This indicates that tributary effects on the river below Myers were not as distinct as those eman- ating from the Bighorn River. For example, the increase in salinity from Custer to Myers averaged 38.7 percent, and ·that from Custer to Miles City averaged 38.6 percent. This suggests that the Bighorn River had a significant effect on the Yellowstone with negligible effects developing from the smaller tributaries in the Bighorn-to-Powder segment. The overall increase in salinity from Custer to Miles City ranged from about 22 percent to 58 percent, depending upon season and parameter (i.e., specific conductance or TDS). The total in- crease in salinity in the river from Corwin Springs to Miles City ranged from 164 percent to 173 percent and from 153 percent to 172 percent during the August-to-April period for specific conductance and TDS, respectively, and it equalled 215 percent and 200 percent during the runoff period. The change in salinity per river mile in the Bighorn-to-Powder segment (to Miles City) was greater than that in the upper river above Laurel but less than that in the Laurel-to-Custer reach. This can be shown in table 58 below. TABLE 58. Salinity change per river mile in the Bighorn-to-Powder segment. Reach above Laurel Laurel to Custer Custer to Miles City Percentage increase in salinity per river mile Maximum 0.2 1.1 0.5 Mini mum 0.05 0.5 0.2 In the upper river above Laurel, the downstream increase in salinity was greatest during the May-July runoff phase, intermediate during the winter, and lowest during the August-October and the spring (March-April) periods. ·A dif- ferent pattern was evident in the Laurel-to-Custer segment of the Yellowstone-- the salinity increase was greatest during the August-October period, inter- mediate between March and July, and lowest during the winter. On the Bighorn- to-Powder reach of the Yellowstone, the increase-was lowest in the August- October period when flows and TDS concentrations in the Bighorn River (table 48), and therefore the tributary's TDS loads, were at their lowest. The salin- ity increase was greatest during the winter-spring, November-April period when the TDS concentrations in the Bighorn were high and when its median flows were greater than those in the mainstem at Billings. Intermediate increases in salinity were obtained during the runoff period below Custer when the high flows in the Yellowstone would tend to negate the TDS loadings from the Bighorn River. Therefore, on the basis of total dissolved solids, there was a con- tinued downstream degradation of water quality in the Yellowstone below Custer to Miles City; the quality was poorest below Custer in the spring and greatest during the runoff period (ignoring the TSS factor). Suspended sediment concentrations were generally much greater throughout the Yellowstone River during the May-July period of high flows than during the rest of the year. Although considerable variation was obtained between sampling 1117 stations (probably due to the general absence of TSS data), an 18-fold maximum average difference became evident between low and high-flow seasons over the entire river above Miles City. The direct relationship between flow and TSS was fairly consistent in the river above Huntley, although TSS-turbidity levels in the spring (March-April) tended to be somewhat higher than might be expected on the basis of flow. This discrepancy was more noticeable in the river below Billings, and in the Bighorn- to-Powder segment, the spring increase in TSS corresponded to a secondary, March- April peak in flow below Custer. The spring increase in TSS, like TDS, can be attributed to inputs from prairie tributaries with their earlier runoff periods and relatively high TSS loads. Most sites on the Yellowstone above Huntley demonstrated a slight decline in TSS-turbidity from August-October to the win- ter period and coincided with a drop in flow. Below Billings, however, TSS- turbidity increased between these seasons regardless of the flow decline, and this continued into the spring season. This might also be attributed to early runoff events from the lowland regions during the winter period. A general downstream increase in TSS-turbidity occurred during all seasons; this was observed in the river above Custer and was carried into the Bighorn-to- Powder reach of the river to Miles City. As a result, water quality in the Yellowstone River also declined downstream, as measured by the presence of suspended sediment and turbidity; these variables detracted from the better water quality during the runoff period. This in turn may affect various water uses in the Bighorn-to-Powder segment. Most notably, the high turbidities at high flows would detract from the use of the river as a domestic supply during runoff season, as median turbidities exceeded permissible criteria for surface water public supply (table 9). The consistently high turbidities would tend to degrade the river aesthetically regardless of the generally uncolored water (color was typically less than 10 units). The high TSS concentrations may affect the Yellowstone fishery. Such a condition was observed in the Laurel-to-Custer reach, and any degradation would be more pronounced below Myers because of the greater TSS concentrations. On the basis of annual median TSS levels (156 mg/1), the river at Miles City pro- bably is a fair fishery judging from the observations of the European Inland Fisheries Advisory Commission (1965). This contrasts with the good-to-moderate fishery in the Yellowstone above Huntley to Laurel and blue-ribbon fishery in the river at Corwin Springs (Berg 1977). With the possible exceptions of fluoride and potassium, the concentrations of most dissolved ionic constituents in the river increased to some extent from Custer to Myers (comparing tables 33 and 55)-in response to inputs from the Bighorn River and the increase in total dissolved solids through this segment. However, fluoride, potassium, magnesium, and chloride continued to be secondary or insignificant components of the samples, and sodium, calcium, sulfate, and bicarbonate dominated the chemical composition of the water. This was also true in the segment of the river below Myers where the levels of dissolved con- stieuents remained constant with small and inconsistent concentration changes in most parameters downstream to Miles City. This is appropriate, as there are no marked increases in TDS levels throughout this reach. Regardless of initial concentration increases in the Bighorn-to-Powder segment, none of the major ionic constituents or the TDS concentrations appeared to be at levels sufficient 148 to consistently and significantly detract from any of the water uses. The water in the Yellowstone between Myers and Miles City was obviously unsui tab 1 e as a surface water public supply due to its high TDS levels and low fluoride concentrations, but it probably could be used for public supply if given cer- tain reservations. The Miles City data (table 57) shows that TDS and sulfate concentrations occasionally exceeded the permissible criteria and standards for public supply and drinking water. About 28 percent of the samples from the Bighorn-to-Powder reach had TDS in excess of 500 mg/1; this was most frequent during the November- to-April period. About 15 percent of the samples had sulfate concentrations in excess of its reference criteria. These findings, and the unusually hard nature of the water, detract from the river's potential value as a municipal supply. Salinity levels in the Bighorn-to-Powder reach may influence the aquatic biota with TDS concentrations occasionally in excess of 400 mg/1. This effect, however, would probably be mild, as TDS exceeded 400 mg/1 in only about 56 percent of the samples and never exceeded the critical 680 mg/1 level through- out this reach. The Bighorn-to-Powder segment may be expected to provide excellent water quality for stock animals, as total dissolved solids and ionic constituents are well below threshold levels. Also, it is qualified to be a Class I water for irrigation, as the boron (<0.35 mg/1), SAR, chloride, sulfate, and TDS-specific conductance levels were well within range of values for this classification (tables 15 and 16). The Yellowstone consistently had a low sodium hazard for irrigation between Custer and Miles City due to the high calcium and low sodium concentrations, and, consequently, the low SAR values. However, it had a med- ium salinity hazard for irrigation from May to October, and the river tended to have a high salinity hazard during the winter and spring when TDS concen- trations were high. A high salinity hazard during the spring could reduce the river's value for irrigation during the March-April period. Sodium, calcium, and sulfate showed the greatest increases in concentration below Custer, consistent with the calcium-sodium sulfate water in the Bighorn River (table 48). As a result, the trend for the Yellowstone to become more sodium sulfate in character downstream continued through the Bighorn-to-Powder reach of the stream. This can be shown using Ca:Na and HC0 3 :S04 ratios as seen in table 59. The effect of the Bighorn was less pronounced when the Yellow- stone had high fl01~s. which would tend to mask the TDS loading from the tributary to some extent. The effect of the tributary was greatest in terms of the HC0 3 : S04 ratios due to the high concentrations of sulfate in the Bighorn; this was also observed on the Clarks Fork Yellowstone River. The extremely low HC03:so 4 ratios in the Yellowstone below Custer occurred during the winter and spring periods when TDS concentrations and flows in the tributary were high in compar- ison to the mainstem. An intermediate HC0 3 :so4 ration was obtained from August to October when Bighorn TDS levels and flows were low. Due to these features, the Bighorn-to-Powder reach tends to have calcium bicarbonate water during high flows, a calcium-sodium bicarbonate water in the late summer and early fall, and a calcium-sodium sulfate water during the late fall, winter, and spring. As observed on the Ye 11 ows tone above Custer, va 1 ues of pH in the Bighorn- to-Powder segment tended to be lower during the high-flow periods in association 149 TABLE 59. Downstream composition changes on the Bighorn-to-Powder reach of the Yellowstone River. Ca:Na Low Flows High Flows HC03:S04 Low Flows High Flows above Laurel 1. 51 2.36 3.73a 5. 71 Billings 1.49 1. 72 2. 12a 3.83 Huntley 1.44 1.46 1. 88a 2.45 Custer 1. 37 1.60 1. 78a 2. 72 Myers 1. 06 1. 19 1.22b 1. 35 0.93C near Forsyth 0.98 1.14 l.]Ob 1. 31 0.96C Miles City 0.98 1. 27 1.o8b 1. 31 0.92c NOTE: Measurements are given inmg/1. aAugust-April. bAugust-October. CNovember-April. with the reduced alkalinities. Also, pH tended to increase downstream below Custer to Forsyth in accordance with the increase in alkalinity through this segment. However, the ranges of this parameter in all seasons and at all sta- tions were never outside of the state's criteria for pH in a B-D3 stream, and they were not indicative of pollution problems. Although median pH decreased from Forsyth to Miles City, pH levels were generally greater in the river at Miles City (table 57) than at Billings (table 31). The river tends to change from a cold-water fishery above Big Timber (Berg 1977) to a warm-water fishery downstream, with the Laurel-to-Custer reach of the river in a transition zone (Peterman 1977). A continuation of this trend is evident below Custer, and the Yellowstone is most likely a warm-water stream at that point. With the exception of the winter season when median temperatures were consistently less than 2.ooc throughout the river and maximums were less than 7.0°C, and ignoring inconsistencies between sites due to lack of data, maximum and median grab sample temperatures increased downstream from Corwin Springs to Miles City. This can be demonstrated by averaging the May-October warm-weather data for sequential sites corresponding to a cold-water reach (Corwin Springs to Big Timber), a transition zone reach (Big Timber to Huntley), and a warm-water reach (Huntley to Miles City) as follows in table 60. TABLE 60. Average May-October warm-weather data for sequential sites. Corwin Springs to Big Timber Big Timber to Huntley Huntley to Miles City Median Temperatures 9.7°C 14.7°C 15. 8°C 150 Maximum Temperatures 16. 6°C 19.60C 22.6°C The different temperature characteristics of the extreme upper Yellowstone and the lower river can also be demonstrated by USGS temperature data taken once daily from the stream near Livingston and at Miles City. Since 1970, only 9.7 percent of the readings from the river near Livingston exceeded 19.4°C during the June-September warm-weather period; only 4.8 percent were equal to or greater than 20oc. In contrast, for the same seasonal and historic intervals, 64.3 per- cent of the once-daily readings at Miles City exceeded 19.40C with 60.9 percent greater than or equal to 2ooc. None of the readings from the river at Living- ston exceeded 22.soc, and maximum temperatures through the five years ranged between 20.5°C and 21oc. At Miles City, however, 24.1 percent of the once- daily temperatures were greater than 22.soc, with maximum temperatures ranging between 240C and 270C. These data show that the Yellowstone River below Billings is appropriately classified a B-03 stream. High phosphorus concentrations were found in the Yellowstone at Custer in excess of reference criteria as a result of a general downstream increase below Laurel and an accentuation of a May-July (and March-April) pulse which first became evident at Laurel (table 28). This spring-early summer pulse of phos- phorus might have been related to the high sediment levels in association with the high flows. Thus, with the high nitrogen concentrations, the Yellowstone at Custer (and Huntley) was potentially eutrophic, although nitrogen-limited. The trend towards eutrophy was apparently negated below Custer with an initial decline in median phosphorus concentrations to Myers, and with a lessening of the March-July pulse of phosphorus. This was probably caused by dilutions from the Bighorn River which had low phosphorus concentrations at its mouth during all seasons, lacking the high-flow pulse. Below Custer, therefore, median phosphorus concentrations were less than or equal to the reference criteria, except during the runoff period, when phosphorus concentrations were constant throughout the Myers-to-Miles City segment of the stream. The river does not appear to be eutrophic below Myers; less than 18 percent of the samples from the Bighorn-to-Powder segment would have both P and N in excess of the nutrient reference criteria, and less than five samples would have both of these nutri- ents in excess of the EPA's (1974b) criteria. Nitrogen concentrations remained high below Custer, although median values were typically less than the corresponding standard for eutrophication. This in turn corresponds to the high, but noncritical,·nitrogen concentrations in the Bighorn River. High winter and low summer variations of this parameter were observed in the Bighorn-to-Powder reach, as in the upper Yellowstone and the Bighorn rivers. Below Myers, nitrogen tended to decline downstream, al- though this was not totally consistent between all sites and during all seasons. The decline was greatest during the runoff period. From Custer to Myers, ni- trogen either increased or decreased by season, depending on the nitrogen level and flow (or nitrogen loading) relationships between the Bighorn River at Big- horn and the Yellowstone River at Custer. That is, nitrogen concentrations in- creased between stations from August to October and from March to April when nitrogen levels in the Bighorn were high compared to those in the Yellowstone. When the opposite conditions were in effect, during the winter and high-flow periods, nitrogen concentrations decreased from Custer to Myers. A slight and noncritical organic loading became evident in the Laurel-to- Custer reach of the river, probably caused by various industrial and municipal discharges from the urbanized Laurel-Billings area. Although sporadically high 151 BODs levels were obtained below Custer, organic loading did not appear to rise in the Myers-to-Miles City reach, as median BODs levels in this lower segment were generally equal to those upstream; the average BODs level at Huntley and Custer equalled 2.6 mg/l whereas that below Custer equalled 2.7 mg/1. Occasion- ally high BODs values, but less than 10 mg/l (table 50), might be expected as natural occurrences. BOD 5 values in the Bighorn-to-Powder reach of the Yellow- stone never exceeded 9 mg;l, and only 14 percent of the samples had BODs levels in excess of 4 mg/1. In addition, median TOC and median COD concentrations (tables 61 and 62) were equivalent to or less than the average for natural surface waters (Lee and Hoadley 1967). Organically polluted streams, such as Yegen Drain in Billings (Karp et al. 1976b, Klarich 1976), demonstrate much higher grab sample BODs and TOC concen- trations and more frequent high values. In Yegen Drain, for example, a median BODs of 14.5 mg/1 and a median TOC of 35 mg/1 was obtained with several grab samples having BODs levels in excess of 80 mg/1; 100 percent of the samples had BODs concentrations greater than 4.0 mg/1 and TOC concentrations greater than 35 mg/1. Based upon these findings, organic pollution does not appear to be a problem in the Yellowstone River. This was confirmed by the high dissolved oxygen levels in the Bighorn-to-Powder reach--minimum values were well above the state criteria for a B-D3 stream and median values were very near satur- ation (tables 61 and 62). A noticeable fecal coliform problem developed in the river through the Laurel-to-Custer reach as a result of wastewater discharges from the Laurel- Billings area. This was most obvious at Billings and Huntley (tables 31 and 32) where median and grab sample concentrations commonly exceeded Montana's water quality standards (Montana DHES 1973). Concentrations were too high to be attributed to natural occurrences. The fecal problem was also evident in the river at Custer, though it apparently had lessened through the Huntley- Custer reach, as there were fewer violations and generally lower concentrations downstream (table 33). At all stations below Billings, fecal concentrations were greatest at high flows. Fecal levels tended to increase downstream from Custer during the May-July period, but they tended to decline in the river be- low Custer to Miles City (tables 33 and 55-57) through the rest of the year. Below Custer, median fecal concentrations in the river were within the state's average criteria at all sites and during all seasons. This suggests a further lessening of the fecal problem due to a natural die-off following the upstream inputs; however, occasional grab samples had concentrations still in excess of state criteria. Nevertheless, fecal levels, for the most part, do not appear to restrict the use of water from the Bighorn-to-Powder segment of the Yellow- stone for municipal supply. Only 7 percent of the samples from the Bighorn-to- Powder reach had levels in excess of the NTAC(l968) and the EPA (1973) recom- mendations for surface water public supply. (USEPA 1973, USDI 1968). The phenol problem that developed in the Laurel-to-Custer segment of the river cannot be assessed in the Bighorn-to-Powder reach because data are un- available. Similarly, herbicide-pesticide concentrations and detection success cannot be established in the Bighorn-to-Powder reach. However, herbicide- pesticide information is available from the USGS on the river at Sidney (USDI 1966-1974b). The potential upstream fluoride problem is apparently eliminated from the river before it reaches Livingston due to tributary dilution. Fluoride concentrations remained low in the Bighorn-to-Powder reach and did not suggest 152 TABLE: 61, Stmr.~ary of l!liscellaneous conHilu('nt dn<l trace (']er.ent concentrations ..-.nured in th(' lellowstone River dl M1ers and near ror!.yth oo' NH 3-fl 5I TOC ,, AI ,, B .. Be Cd co ,, '" fe Hg u ,.., Ho Ill Pb s. S< v '" Yellow!tone Fiver at Hyers Hiscellaneous t~~~~ t ~~~~!.~a~~~a metals N Nin <•· 11('d 22 60 lOB " 7 0.03 o. 14 0.01 20 B. 7 lJ 11 • 2. I lJ B.9 7 0 .• '·' 0, B • .005 .055 .018 11 "'· 10 0. 33 0.10 " 0 0 0.001 ( .001 ( .027) 2 .01 .02 .02 19 ' 01 0.06 c. 01 " 0. 13 11 1.6 " 0.0 c.OOI <.,0002 ( .002?) " -<.01 o. 37 0. 11 lJ ( .05 0.10 ... 10 B 0.0 .004 .002 6 .oa 1.2 . 40 19 <.01 0.07 o. 03 riOT[: MN5urements are eApressed in mull. aV: '-· 10, N•S. bBe: <.01, N•2. 'Ag: 0. N•2: Cr: c.OI, 11•6. dOO e~pressed as percenta10e of s•turu lor~. Oi ssolved N Mh1 2 0.0 5 0.0 ' .002 12 .05 2 .100 ' 0.0 ; 0.0 2 0.0 ' 0.0 ' .001 I; .01 ' 0.0 3 .03 15 0.0 3 0.0 ' .001 5 0.0 6 .Wi J .53 5 .0004 ' .01 meuls ... "' .001 . 001 .01 .04 .006 . on5 .15 " .100 . 100 0.02 < .01 0.001 c.OOI .001 .001 ~ .01 0.0 .019 .004 .15 .03 .0002 0.0 .05 .03 .03 .01 .003 .0(12 . 013 .002 .00~ .002 .002 .002 ·" .50 .002 .001 .04 .02 153 iellowstone River near rorsyth Miscellaneous canst i tucnt~ dndb tot~l recoverable met<JI5 Dissolved metals' II Hir~ ... Mt~d N "'" ••• Mod 22 86 lOB 05 7 ').02 0. 14 0.10 20 B. 5 lJ 11 • •. 7 " 10 B 0.10 " 1.2 6 0. 0 .15 .02 ; ' 01 '023 .002 5 .ooj .005 .004 11 ' . 10 0. 29 0.10 12 " ·" .14 3 0.0 '.I '.I 5 0.0 0.01 ~ .01 20 0.0 ( .01 .002 ; c.OOI 0.001 0.0 2 <.OJ 0.01 0.01 2 o.o '002 .001 5 0.0 0.09 < .01 24 < .01 0.17 0.01 ' .001 .006 .002 20 .02 19 1.7 "· 0.0 .10 .04 I . 44?) 19 0.0 c .0029 .0006 ' 0.0 0.0010 0.0001 ' ~ .01 0.05 0. 02 18 .03 ... .12 15 0.0 .OJ .01 (. 3?) • 0. 0 .00? .002 5 .001 .02 .005 20 < 01 (. 10 ( .05 5 o.o .003 .001 ' < 001 0.004 0.002 5 .001 .003 .002 5 .06 1.2 ... 3 .55 .6< .50 B <.OS 0.18 <.I 5 .0001 .001 .001 24 ( .01 0.12 0.02 6 0.0 .OJ .02 TABLE 62. Summary of miscellaneous constituent and trace element concentrations measured in the Yellowstone River near Miles City. COD Color ooa NH3-N Si TOC Al As B Be Cd Co Cr Cu Fe Hg Li Mn Mo Ni Pb Se Sr v Zn Mi see 11 aneous constituents and dissolved metals N Min Max Med 16 6 73 15 15 l 11 6 45 66 117 97 16 0. 01 0.41 0.13 114 3.8 17 11 43 1.4 16 6.0 3 <.01 0.03 0.01 3 <.01 0.03 0.01 53 .016 .224 . 150 3 <.01 <.01 <.01 3 0.0 0.0 0.0 3 0.0 . 01 0.0 3 0.0 .002 .002 82 0.0 1.8 .02 3 0.0 .0002 .0001 4 <.01 0.05 0.03 17 0.0 .05 .005 3 .001 .003 .002 3 .002 .006 .003 3 .001 .002 .001 3 . 001 .002 .001 3 . 001 .002 .002 3 0.0 .02 0.0 NOTE: Measurements are expressed in mg/1. aDO expressed as percentage of saturation. 154 Total recoverable metals N Min Max Med 3 1.9 9.0 2.2 11 <.001 0.03 0.009 10 <. 10 0.22 0. l 0 l -- -- <. 01 22 <.001 0.003 <.001 l -- -- . 01 7 0.0 0.02 <.01 25 <.01 0. l 0 0.01 24 .02 38 1.8 13 <.0002 0.001 0.0002 23 .01 1.5 . 12 14 <.01 <. ll <.05 6 <.001 0.002 0.001 5 .06 l.l .42 6 <.05 0.22 <. l 0 25 <.01 0.27 0.02 I problems other than being below the optimum level for drinking water. In con- trast, the high arsenic and mercury levels observed in the upper river were ap- parently carried into the Bighorn-to-Powder reach of the stream (tables 61 and 62). Upstream, arsenic occasionally violated the Public Health Service (1962) standard for drinking water, although it was not at levels high enough to necessitate a rejection of supply or to violate the NTAC and the EPA criteria (table 9). Dissolved and TR concentrations of arsenic showed an overall de- cline downstream with a lower frequency of violations in the Bighorn-to-Powder reach. Arsenic was never at levels sufficient in the Yellowstone to exceed the criteria for livestock and the aquatic biota. Grab sample and median concentrations of mercury, both in its dissolved and TR forms, often exceeded criteria for aquatic life. For example; of the samples analyzed for mercury from the Bighorn-to-Powder reach with a sufficient detection limit (to 1 ~g/1), 29 percent had TR concentrations equal to or greater than 2 ~g/1, and 10 percent had TR concentrations between 10 ~g/1 and 20 ~g/1; between 45 percent and 81 percent of the samples had TR concentrations equal to or greater than 1 pg/1. In measuring the dissolved concentrations, 46 percent of the samples had detectable levels of mercury (>1 pg/1), and 31 percent of the samples had levels equal to or grea.ter than 2 pg/1. Grab sample mercury concentrations also occasionally exceeded the EPA's criteria for public water supplies, although they were not at levels sufficient to be harmful to stock animals (California WQCB 1963). Like mercury and arsenic, all of the remaining metals and trace elements were detected in some of the samples from the Bighorn-to-Powder reach of the Yellowstone, at least in their TR forms (tables 61 and 62). Although silica declined downstream below Custer, the overall concentrations of these constit- uents appeared to be somewhat higher in the Bighorn-to-Powder reach than in the Laurel-to-Custer segment upstream. For example, the mean median TR and mean median dissolved concentrations of nine metals that were consistently analyzed at all sampling stations equalled 0.18-0.19 mg/1 and 0.079 mg/1, respectively, the in Laurel-to-Custer reach. Higher levels of 0.26-0.27 mg/1 and 0.089- 0.090 mg/1 were obtained in the Bighorn-to-Powder segment. In both reaches, higher TR concentrations were obtained.for the metals; about 43 percent of the TR concentrations in the Laurel-to-Custer reach were in the dissolved form and 34 percent in the dissolved form downstream. Thus, the TR levels of the metals apparently increased more between the Laurel-to-Custer and Bighorn-to-Powder segments than their increased components; this is probably a function of the higher sediment levels in the river below Custer. However, the concentration increases of the TR and dissolved forms of Fe, Mn, and Sr from Custer to Miles City were not as great or as consistent as they were in the river from Corwin Springs to Custer. This can be seen in table 63. Greater TR over dissolved concentrations of Sr and boron were evident in the Bighorn-to-Powder reach, as in the upstream segment. Several trace elements demonstrated high median and grab sample concentra- tions, particularly in their TR forms, which may indicate water quality problems. This includes silica, ammonia, Al, As, B, Cr, Cu, Fe, Hg, Mn, Sr, V, and Zn; but especially Al, Fe, Mn, and Sr. The high maximum concentrations of these vari- ables were generally obtained in conjunction with high suspended sediment levels. However, the concentrations of several other trace elements were low even in the TR form, and, as a result, these variables probably would not detract from 155 any water uses. These constituents would include Ag, Be, Se, and Mo, particu- larly, but also Cd, Co, and Li. TABLE 63. Concentration increases of TR and dissolved forms of Fe, Mn, and Sr in the Yellowstone River above Custer and at Myers, Forsyth, and Miles City. Fe Mn Sr TR Dissolved TR Dissolved TR Dissolved Yellowstone above Cus tera A D.42 0.020 0.04 0.013 0.08 0.208 B 0.55 --0. 11 --o. 19 -- c 0.62 0.04 0.05 0.05 0.23 0.408 D 1.5 0.084 0.39 0.029 0.30 0.455 Yellowstone at Myers 1.6 0.03 0.11 0.01 0.40 0.60 Yellowstone at Forsyth 1.7 0.04 0.12 0.01 0.41 0.60 Yellowstone at Miles City 1.8 0.02 0.12 0.005 0.42 -- aPoints A, B, C, and D represent sequential downstream reaches of the Yellowstone River above Custer. Of those trace elements demonstrating occasionally high TR levels, many had low median TR concentrations or low dissolved concentrations. This would indicate that Al, Cr, Cu, and V, and also Ba, Ni, and Pb caused no water qual- ity problems as their median dissolved levels were 1~ell below various reference criteria at all stations. Of the trace elements, therefore, ammonia, As, B, Fe, Hg, Mn, Sr, and Zn seem to have the greatest potential for causing water use problems. This would exclude silica with median concentrations in the Bighorn- to-Powder reach below the average for surface waters (Davis 1964). Arsenic and mercury may cause water quality problems. Strontium concen- trations do not appear to be at levels adequate to promote radiochemical pro- blems for the reasons mentioned in the description of Beauvais Creek. Dissolved boron levels were well below the criteria for public supply, stock animals, and aquatic life, and they were well below the irrigation criteria for a Class I water. Maximum and median dissolved manganese concentrations were also less than these reference criteria; this was most obvious in zinc concentrations. Median dissolved iron concentrations were also below the criteria for drinking water and public supply, irrigation, and aquatic life; maximum dissolved values at l~yers and near Forsyth were also less than these levels. However, occasion- ally high maximum levels of iron were obtained in the dissolved and TR components near Miles City, suggesting the development of iron-related water quality pro- blems in the lower reach of the Yellowstone River. For example, about 7 percent of the Yellowstone samples from the Miles City locations had dissolved iron concentrations in excess of 0.2 mg/1·, and about 6 percent of the samples had concentrations in excess of 0.3 mg/1. Median ammonia concentrations were high in the Yellowstone River at Huntley-Custer (table 36) and in the Bighorn River at its mouth. (table 48). As a result, high ammonia concentrations were also obtained in the Yellowstone downstream of Custer. Median ammonia levels tended to decline from Custer to 156 l Myers (comparing tables 36 and 61) and then show a steady downstream increase from Myers to Miles City (tables 61 and 62). However, at the median pH levels of the mainstem at Miles City, only about four to five percent of the ammonia would be in the un-ionized and toxic, NH 3 form (<0.01 mg/1). This was also true in the Yellowstone at Myers-Forsyth, and un-ionized ammonia concentrations would be below the critical level established by the EPA (1973). Thus, ammonia would not be present in the river as a toxicant to.aquatic life, but it may be a eutrophic factor. That is, if annual median ammonia-nitrogen concentrations are added to the median inorganic nitrogen levels obtained from the various stations below Custer, total soluble inorganic nitrogen (TSIN) concentrations would exceed the nitrogen reference criteria for eutrophication during some seasons, but not the criteria·used by the EPA (1974b). However, these higher TSIN levels apparently do not alter the non-eutrophic status of the Yellowstone described previously. During the critical summer-to-late fall period of high biological activity in the river, the Yellowstone did not appear to be eutrophic as both TSIN and P concentrations were below the corresponding reference levels;· the river would be more N-than P-limited during this August-to-October season. During the less critical and biologically dormant seasons of winter and spring, TSIN con- centrations generally exceeded the N criteria due to the seasonal nitrogen peak at this time. Phosphorus was generally below its reference levels, establish- ing the river as non-eutrophic and P-limited during the November-to-April. During the May-to-July period, TSIN concentrations were below the N criteria, but phosphorus exceeded its criteria due to the high-flow pulse of phosphorus described previously. Thus, the river was non-eutrophic and distinctly N- limited during this particular phase of the hydrologic cycle. SARPY CREEK DRAINAGE Sarpy Creek is a small intermittent tributary to the Yellowstone River; however, it does have a rather extensive drainage area south of Hysham between the Tullock and Armells Creek systems. During 1974, 35 percent of the measure- ments taken showed zero flow fn the stream and 56 percent of the flow measure- ments were less than one cfs (USDI 1974). Sarpy Creek, therefore, would not be expected to have a significant effect on the Yellowstone mainstem; its im- portance lies in the fact that its headwaters are in an active strip mining area. Because of this, considerable water quality data are available on its upper drainage due to sampling programsi nit fated for environmental impact statements (USDI 1976). Data are also available from the USGS for a location near the creek's mouth (USDI 1976), and from the state WQB. The upper Sarpy Creek drainage has unusually poor water quality (table 64). Although occasionally high concentrations of TSS were obtained upstream in the creek, the 38,650 mg/1 reading is especially notable. Overall, TSS levels did not significantly detract from the creek's quality; median TSS concentrations were less than those in the Yellowstone River. Rather, the poor quality was caused primarily by the extremely high TDS concentrations of the upper reaches-- median TDS levels were 4.5 to 11.6 times greater than those in the Yellowstone River, depending upon season. As in most streams, TDS and flow were for the most part inversely related in upper Sarpy Creek with extremely high concentra- tions during the low flows of summer and low concentrations during the March- 157 TABLE 64.-SurTrnary of the phys,cal paramet~rs measur.ed in the Upper Sarpy Creek drainage near Westmoreland. August-October November-February March-Apri 1 May-July N Min Hax fled N ~1in Nax 11ed N f1in Mox Med N ~1in Max Med Flow 16 0.1 0.0 0.6 6 0.0 25.9 0.7 138 0.1 78.1 1.2 55 0.0 21.2 0.7 Temp 20 2.5 35 13.5 22 0.0 3.5 0.0 26 0.0 9.0 4 32 6.7 31 18.5 pH 21 7.6 8.7 8.1 26. 7 .I 8.4 7.65 26 7.26 8.5 8.0 34 7.5 9.1 8.14 sc 3. 3077 5181 4762 Hi 283 6660 2500 14 275 3300 2795 18 1800 5650 3320 lOS 14 1442 5862 4203 22 101 7002 2303 22 351 3154 2286 29 1565 5462 2987 Turb 21 2 >1000 15 26 2 180 12 25 4 172 10 36 0 62 16 TSS 20 1 38,650 12 26 2 190 16.5 29 1 216 8.5 39 0 209 11 DO 0 ----0 2 4.7 11. 1 7.9 7 10.2 11.3 10.8 4 8.0 8.6 8.2 BOD 3 9 16 II 10 1.8 >11 4 13 1.0 5.0 4.1 20 <.I 52 6.6 FC 0 ------5. 1 500 11 6 0 86 10 8 <I 1030 175 Ca 3 150 290 190 12 18.8 229 109 12 9 178 129 18 30 210 143 Mg 2 264 342 303 9 9.2 356 203 12 18 238 177 IS 209 425 275 TH 3 1607 1881 1812 10 85 1880 906 12 170 1387 1080 15 134 2029 1608 II a 4 235 805 552 II 20 913 194 16 19 370 214 21 218 1077 371 K 0 ------4 13 54 27 7 6 12 7 9 11. 7 29.5 14 SAR 0 ------6 0.9 9.5 2.5 7 0. 7 3.7 2.7 9 2.6 5.8 3.5 HC0 3 3 220 610 610 10 76 1999 598 12 144 641 539 15 529 1002 683 TA 21 lBO 1900 568 26 50 1638 490 23 116 641 480 34 430 867 555 504 21 224 3687 1817 26 18 3825 1082 26 81 2383 1219 36 718 3480 1650 Cl 3 24 84 24 10 5.0 27 10.5 14 4 26 12.0 15 0 35 19 F 21 0.4 1.4 0. 7 25 0.1 0.8 0.4 29 0.1 1.1 0.5 38 <.2 1.2 0.4 II 3 <.02 <.05 <.02 10 0.02 0. 57 0.27 12 0.0 0.04 <.02 18 <.02 3.75 0. 22 p 3 0.03 0.03 0.03 .9 <.01 0.30 <.03 14 <.01 0.07 0.03 18 0.0 0.10 <.03 rwn: f.lcasurements expressed in mg/ 1. ~------------ April peak flow period. This shows the influence of the earlier runoff period in lowland prairie regions over mountainous drainages which, in turn, is re- flected in mainstem discharge (secondary March-April peak) and TDS levels (highest in March-April below Custer). The waters in upper Sarpy Creek were slightly saline (moderately saline in the summer), extremely hard, and they had a sodium sulfate composition char- acteristic of many small streamsin eastern Montana. Sulfate concentrations were high--about 50 percent of the TDS weight was sulfate. All dissolved constituents were in greater concentrations in upper Sarpy Creek than in the Yellowstone River, although fluoride, chloride, and potassium were minor ions. Calcium- magnesium and bicarbonate were secondary constituents with magnesium concen- trations greater than calcium concentrations. This suggests an extension of the dolomitic formations into the Sarpy Creek drainage. The high TDS and high ionic constituent concentrations preclude many water uses from the stream, in- cluding that of surface water public supply--TDS and sulfate concentrations are well above the reference criteria for this use (table 9). In addition, although the overall TSS levels of the stream would not be expected to affect the aquatic biota, TOS concentrations exceeded 1350 mg/1 and specific conduc- tances greater than 2000 ~mhos/em would indicate a detrimental influence on freshwater life (Ellis 1944). Upper Sarpy Creek has a poor Class III water for irrigation due to the high TDS and sulfate concentrations (tables 15 and 16); the water has a very high salinity hazard for this use but a low sodium hazard due to the low SAR values (table 64). As indicated by the EPA (1976), water of this nature" can be used for tolerant plants on permeable soils with careful management practices." Such tolerant crop and forage species are listed in table 17. Regardless of water quality, however, the generally low flows in the upper reach would probably eliminate the possibility for many of these uses. The water quality in upper Sarpy Creek is only fair for application to stock ani- mals (tables 10-14), and, due to the high TDS levels, it should not be used to water poultry. Median sulfate and bicarbonate concentrations were consistently greater than the limiting levels for stock animals, and magnesium concentra- tions occasionally exceeded threshold levels. Extended consumption of these high sulfate waters could be harmful~to animals (California WRCB 1974). How- ever, TDS concentrations decline downstream in Sarpy Creek to its mouth (table 65), suggesting that the waters in lower Sarpy Creek may be more suitable for stock animals. Sarpy Creek was unusual because it showed a general downstream improvement in water quality and a reduction in TDS concentrations from about 23 percent to 37 percent, depending upon season; the reverse was found to be true in most other streams. Sarpy Creek also showed a slight downstream increase in TSS concentrations, but they were not noticeably high even in the lower reach, and were not expected to significantly affect the aquatic biota. As in the upper reach, salinity appeared to be the major problem in down- stream quality, especially during the lower flows. The lower reach, therefore, probably would not be suitable as a surface water public supply, due again to the high TDS, sulfate, and hardness levels. Salinity may cause problems for the aquatic biota in the lower reach, as median TDS concentrations exceeded 159 .... "' 0 TABLE 65. Summary of the physical parameters measured in Sarpy Creek near Hysham. August-October November-February II Min Max Med N. Min Max Med N Flow 3 0.02 0. 3 0.2 9 0. 3 193 1 3 Temp 3 7 .o 18.5 8.2 8 0.0 6.5 0.5 4 pH 3 8.20 8.5 8.4 9 7.6 8. 5 8.10 4 sc 3 2340 4300 3130 9 288 3720 2395 4 TOS 3 1890 4280 2689 9 182 2610 1650 3 Turb 3 7 14 8 9 3 30 4 4 TSS 0 ------2 6.0 9.5 7.8 2 DO 2 1.8 8.4 5. 1 9 8.0 12.5 10.2 4 000 0 ------2 2.8 3.0 2.9 2 FC 0 ------2 18 20 19 2 ca 3 59 190 122 9 18 110 86 3 Mg 3 92 210 113 9 8.0 130 74 3 TH 3 530 1300 770 9 78 810 535 3 ua 3 430 880 515 9 27 600 370 3 K 2 9.7 12 10.9 7 7.2 14 9.8 2 SAR 3 B. 1 10.0 8.2 9 1.3 9.2 7.0 3 HC0 3 3 548 886 573 9 89 853 605 3 TA 3 470 727 471 9 73 700 496 3 504 3 1000 2500 1345 9 64 1300 750 3 Cl 3 16 33 17 9 3 . 21 14 3 r 3 0. 3 0.4 0.4 8 0.1 0.5 0.4 2 ll 3 0.0 0. 75 0.01 8 0.0 0.2 0.03 3 p 3 0.01 0.05 0.03 9 0.0 0.46 0.02 3 NOTE: Measurements expressed in miJ/1. I On 0 March-Apri 1 May-July Min Max Med N Min Max Med 3.2 387 15 6 0.4E 30.2 15.5 0.0 10.5 ?..5 6 11.0 23.0 14.9 7.9 8. 5 8.25 6 8.2 8. 70 8.4 215 2800 2203 6 1151 4300 2603 150 2269 1430 5 1570 3578 2300 10 100 24 5 7 81 48 14.0 47 30.5 3 12 148 66.2 10.4 11.2 10.9 5 7.8 8.6 8.1 2.7 3. 7 3.2 2 4. 9 6.3 5.6 29 79 54 1 ----0 20 91 88 6 48 130 83 10 129 95 6 52 190 130 91 758 610 6 336 885 715 14 385 240 6 105 770 383 7.4 9.9 8.4 4 4.4 11 9.3 0.6 6.1 4.2 5 2.5 6.9 5.6 95 556 425 6 235 704 474 78 456 349 6 193 604 417 40 1096 770 6 340 1841 1131 4 11.8 11 6 0. 2 17 14 0.1 0.3 0.2 4 0.3 0.4 0.4 0.1 0.24 0.1 6 0.0 0.5 0.04 0.02 0. 35 0.02 6 0.02 0.11 0.03 l· ~ . ' 1350 mg/1 and specific conductances exceeded 2000 ~mhos/em. Furthermore, the waters would have a high or very high salinity hazard for irrigation. Because of the downstream reduction in TDS concentrations, the lower reach waters would have good quality for stock (Seghetti 1951), although bicarbonate and sulfate concentrations were still greater than the limiting levels for animals (California WQCB 1963). A change in chemical composition became evident in Sarpy Creek, probably a reflection of intermediate inputs with a different water quality diluting the TDS concentrations. In general, calcium plus magnesium and sulfate concentra- tions declined downstream, sodium levels increased significantly, and bicar- bonate declined slightly. Fluoride, chloride, and potassium continued to be insignificant constituents of the water. The stream near Hysham tended to become more sodium sulfate; the average (Ca + Mg):Na ratio declined from 1.39 to 0.55, and the average HC03:S04 value increased slightly from 0.44 to 0.55. The average Ca:Mg ratio increased to the lower reach from 0.60 to 0.95, indi- cating that the intermediate inputs to Sarpy Creek were probably sodium sulfate- bicarbonate and not derived from dolomitic regions. The lower reach's water samples showed higher SAR values (table 65). As a result, the lower reach had a median sodium hazard for irrigation. Overall, the lower segment of Sarpy Creek appears to have a poor quality, borderline. Class !!/Class III water for irrigation (tables 15 and 16), and the low summer flows may eliminate the use of the stream for irrigation altogether. Sarpy Creek has been classified a B-D 3 stream by the State of Montana (Montana DHES, undated), although the water-use description for this classifi- cation is not very appropriate for the water quality in the stream. Because of the ~later's high TDS concentrations, Sarpy Creek does not appear to be " ... suitable for drinking, culinary, and food processing purposes ... " (Montana DHES, undated), and it does not appear to be suitable for the " .. . propagation of non-sa lmoni d fishes . . . " (Montana DHES, undated). Its va 1 ue as an agricultural supply is also questionable. High inorganic nitrogen and ammonia concentrations, which might have been derived from explosives used in strip mining activities in the region, were occasionally obtained from·the stream. Also, ammonia levels appeared to be sufficiently high at times (table 66) to be potentially toxic to the aquatic biota through the pH levels of the water--un-ionized, gaseous ammonia was sometimes in excess of 0.02 mg/1 (USEPA 197 3). Other physical characteristics indicate, however, that Sarpy Creek's B-D3 classification is appropriate. For example, the pH and dissolved oxygen levels were in accord with the criteria for a B-D3 water, and the high maximum temper- atures were also normal for this classification. Also, fecal coliform concentra- tions declined downstream and did not generally suggest water quality problems in either the upper or the lower segment (tables 8 and 9). The creek was defin- itely non-eutrophic as both median nitrogen and phosphorus concentrations were be 1 ow the reference criteria. The upper drainage of Sarpy Creek appears to be organically polluted to some extent with high BOD 5 concentrations; median values were generally greater than those obtained in other streams. However, this pollution does not appear to be caused directly by municipal discharge due to the low fecal coliform 151 TABL[ G6 SLJrTP.lry of misce11a.ncous con~~ituent and tr~cc e\cr:'(!nl concentrations 11\CdSured in the Sarpy Creel drain.,ge. Upper Sarpy Creel drainage near "-'t~stmon•land Sarpy Cree~ ncar fiysham Miscella.neous Mi!.ce11aneous ccnH illll"nl\ a.n-d con!.tituents dncl total recoverable tot.tl reco•·er.,blo Dissol~ecl cet.th" metals Dissolved n>lolls ~:~eta ls " I'\ in .... ,.., " ~in ,,,. ,., " Min .... ""' " "'" ""' "'' ,, 21 0.0 0.0 0.0 coo 26 II '" J8 Color 26 ' 1 Sa 4) oo' 14 16 108 80 laiJ·II 29 o. r 1.2 'I O!G 94 0.0 ~~. 4 , ' 16 0.0 0.0 o.o Si 6 0.0 \4. s '. 9 14 0. R 12 !1. 5 " l9 .05 3. 9 .35 30 o.u < .01 ( .01 • .II 1.5 .21 2 '.0 0.01 .005 ,, II 0.0 .011 .002 2 .DOl .002 .002 B 3 .16 .51 .33 " .II ·" ·" " 2 .06 .07 .07 ,, 2 ( .01 < .01 ~. 01 2 0.0 < .01 < .01 (d 10 ~. 001 0 .()][, ~ .002 13 0.0 0.02 (. 01 2 0.0 .001 .001 Co 2 .04 .08 .06 2 ~ .015 < .016 ~.016 Cc 32 ' ''" 0.04 0.009 10 0.0 0.04 .003 2 0.0 -<.01 ( .01 (. 171?) '" '2 .002 0.06 0.01 13 ( .01 0.09 ( .01 2 .QOI .003 .002 ,, 10) ' 02 22 0 39 " 0.0 0.60 0.07 13 ·" II .bO 14 .01 .41 .07 "" 16 < 0001 0.007 0. 001 II 0.0 < .001 .0001 2 0.0 ~ .000\ ... 0001 Ll 1 .02 .07 .045 2 .04 .08 .06 Hn " .009 1.1 .15 II .02 .69 .17 2 ·" .13 .09 (6 .0? l "" 2 ... 005 < .005 ( .005 IIi " .OOJ .08 .01 2 .001 .005 .003 PD 10 < .01 0.10 '. 10 2 .001 .OOJ .002 s. 10 0.0 .{1!)1 0.0 Sc 2 15 2' s 2.0 ' ' .04 .51 .29 2 < .00!1 '.008 <.008 '" '1 <_QOS 0. ()') 0.012 8 <.01 0.12 0.0.1 2 .01 .01 .01 ~~'J: ··.ooz. 11•2; S••: o.o. 11•1. bOO ~·•pr·e!.sed as percentci!Jl' of saturation. 162 .< (tables 64 and 65) and oil and grease (table 66) concentrations, although it might ultimately have been derived from this source via groundwater inputs. As alternatives, the high BODs levels could have been derived from the same sources as the high nitrogen concentrations or from concentrated soil extracts reaching the stream. The latter alternative would probably color the water, aesthetically degrading the stream; the upper Sarpy samples were noticeably colored (table 66). Organic pollution from some source was also indicated by the upper creek's high COD levels and in the low percentage of DO saturations near Hysham. The BODs concentrations appeared to be significantly diluted by the time the stream reached its mouth, and they were of insufficient magnitude to consistently reduce the stream's DO concentrations to levels in violation of the state criteria for a B-D 3 stream. Most of the trace elements were detected in at least some of the samples from Sarpy Creek (table 66). High TR concentrations were obtained in some in- stances, especially Fe and Mn, but also Al, B, Sr, Si, and V. Some of the minor constituents--Ag, Be, Br, Mo, and S--were never detected in the samples. Several of the remaining minor constituents--As, Cr, Li, Ni, and Se--may cause water quality problems due to their low median and maximum TR concentrations. In some cases, median TR or dissolved levels were below various criteria, but occasional samples--Cd, Co, Cu, Pb, V, and Zn--had TR concentrations in excess of reference levels. These six constituents probably did not indicate water quality problems in Sarpy Creek, but they would be more likely to than the trace elemenets mentioned previously. Median TR concentrations of Al, Fe, and Mn exceeded various water quality criteria, indicating that these trace elements are potentially limiting. How- ever, as the median dissolved concentrations of the first two parameters were less than the reference levels, Al, Fe, and l~n probably did not detract from water use except in a few instances when dissolved levels were high (e.g., in 14 percent of the samples, iron concentrations were greater than 0.3 mg/1). B, Ba, Si, and Sr·did not indicate water quality problems. Of the trace ele- ments, therefore, mercury seems to have the greatest potential to affect the aquatic biota and other water uses, particularly in the upper reach of Sarpy Creek. Additional data would be necessary, however, to more fully assess the extent of this possible effect. ARMELLS CREEK DRAINAGE Armells Creek is anothe~ smull tributary to the Yellowstone River, and is not expected to have a substantial effect on mainstem quality. Armells Creek probably has a greater tendency towards perenniality than Sarpy Creek. Armells Creek also drains an active strip mining area with a coal-fired electrical generating facility, and, as a result, a great deal of water quality information has recently been gathered on the stream by the USGS (USDI 1976) and by the state WQB (Montana DNRC 1974)·. The USGS maintains three sampling stations in the drainage as indicated in tables 67-69, and the more dispersed collections of the state WQB were combined in conjunction with these three USGS locations. Many of the water quality features observed in Sarpy Creek also occur in Armells Creek. However, certain differences are evident. Both streams had high TDS concentrations, which significantly degrade the water quality. This 163 TABLE 67. Summary of the physical parameters measured in the east fork of Armells Creek and Sheep Creek tributary (one sample) near Colstrip. August-October flovcmbcr-February Harch-Apri 1 May-July I~ Min Max Med I~ folin Max Med II Min Max Med N Min Max fled Flow 4 0.0 3. 7 1. 45 7 0.05 169 1.8 9 0.07 21 2.04 6 1.4 20E 4.0 Temp 3 6.0 19.0 7 .o 7 0.0 5.0 0. 5 9 0.0 24.0 11.8 8 9.0 26.1 15.5 pH 4 8.20 8.80 8.3 7 7.5 8.6 7. 9 9 7.7 8.30 8.1 8 7.60 8.80 8.05 sc 4 2330 4524 3185 7 290 4820 3780 9 703 5043 3700 8 1299 8850 3400 TDS 4 2000 3835 2870 7 178 3720 2970 9 514 4885 3150 7 981 8955 3310 Turb 4 0 25 2 7 1 40 4 9 4 155 10 8 2 135 9 TSS 0 ------2 10.5 39.0 24.8 5 7.2 245 28 3 31.2 201 77 00 2 8.6 11. 1 9.9 7 8.7 11.0 10.0 8 8.0 12.5 9.8 6 3.5 15.4 8.8 ( 1. 9?) BOD 2 1.2 1.3 1.3 7 0.1 4.4 0.7 9 1.7 5.3 2.8 4 0.6 1.7 1.2 ( 9. 5?) ( 11. ? ) FC 0 . ------2 0 0 0 5 0 36 0 1 ----0 Ca 4 48 285 145 7 22 280 240 9 11 290 228 8 98 291 210 Mg 4 81 362 175 7 13 340 240 9 2.9 487 290 8 91 835 315 Til 4 455 2200 1100 7 110 2100 1600 9 40 2520 1800 8 620 4165 1850 l~a 4 220 1030 261 7 13 410 300 9 72 669 310 8 50 1220 310 K 2 16 19 18 5 7.4 23 21 4 8.9 21 17 7 12 18 17 SAR 4 2.5 21 3.1 7 o. 5 4.0 3.7 9 1.5 9.5 3.6 8 0.9 8.2 3.5 HC0 3 4 376 651 512 7 71 621 549 9 175 612 506 8 159 570 419 TA 4 308 593 420 7 58 509 450 9 144 502 419 8 130 468 348 504 4 1200 2078 1585 7 75 2300 1900 9 170 3048 2000 8 564 6184 2100 Cl 4 18 86 42 7 4.1 66 48 9 0.2 52 26 8 5.3 75 49 f 4 0.3 0.7 0.5 5 0.0 0.7 0.5 8 0.1 0.6 0.3 7 0.3 0.5 0.3 I~ 4 0.03 .10.10 0.04 7 0.06 0.52 0.13 9 0.0 1.81 0.04 8 0.0 0.89 0.09 ' p 4 0.02 0.28 0.03 7 0.0 0.22 0.04 9 <.01 0. 30 0.03 8 0.01 0.33 0.06 fiOTE: f1easurernents expressed in mg/1. I ) : . / .. .. Flow Temp pH sc TOS Turb TSS DO BOD FC Ca M9 TH Na K SAR HC0 3 TA II p parameters measured in the west fork of Armells Creek near Colstrip. N 0 0 August-October l~ln Hax Ned 0.01 5.0 8.6 6740 5710 20 11.6 1.7 140 300 1600 1200 16 13 411 34 7 3800 44 0.2 0.0 0.04 liOTE: Measurements expressed in mg/1. tlovember-February N Min 1·1ax Med 7 7 7 7 7 7 6 7 7 7 7 6 7 7 7 7 7 6 7 7 0.01 3.11 0.05 0.0 9.0 2.0 7.4 8.9 7.8 3272 7100 5000 2510 5660 3810 2 20 3 6. 4 0.5 130 120 820 468 10 6.6 353 290 1500 18 0.2 0.0 0.01 11 4.4 280 290 10.5 10.2 2.0 0 167 190 1900 1300 1200 690 15 14 12 8.2 875 486 718 417 3400 2300 39 15 0.4 0. 3 0.36 0.0 0.06 0.01 II 7 7 7 7 6 7 3 7 7 3 6 6 6 6 6 6 6 6 6 6 7 7 March-April Min Max Med 0. 5 0.0 7.5 765 383 4 28 1. 60 15.0 6.0 8.4 7.95 5820 4190 5026 4695 210 17 16.8 1504 28 8.8 0.8 0 33 27 190 57 6.9 1.8 134 110 180 0.2 0.1 0.0 0.0 13.2 11.1 8.4 1.5 190 250 301 6 206 255 1720 1650 940 889 14 12 9.9 9. 5 748 658 614 540 3000 2900 31 19 0.6 0.4 0.09 0.0 0.27 0.02 II 5 5 5 5 5 5 0 5 5 0 5 5 5 5 5 5 5 5 5 5 5 5 5 May-July Ml n Max fled 0.10 17 2.0 7.5 22.5 18.5 7. 7 8. 1" 8.1 3700 6000 5200 3270 5030 4550 3 55 10 6.7 0.9 160 160 8.8 2.1 200 280 8.3 1.4 200 230 1100 1600 1400 630 1100 930 12 15 13 8.2 12 11 481 666 593 395 546 486 2000 3200 2800 22 81 27 0.3 0.4 0.3 0.0 0.12 0.02 0.01 0.11 0.04 ..... 0\ "' TABLE 69. Sunmdry of the physical parameters rreasured in Annells Creek. near Forsyth. August-October Uovember-February N ~lin Max Med N ~1in Max Med II Flow 4 0.05 2.1 0.54 12 0.24 462 1.94 9 Temp 4 7.0 25.0 16.5 12 0.0 5.5. 0.0 9 pH 3 8.0 8. 7 8.4 12 7.4 8. 32 7.95 9 sc 4 3300 4240 4030 12 395 6500 3340 9 lOS 4 2240 3840 3025 11 245 4100 2560 B Turb 4 1 50 14 12 6 400 20 9 TSS 0 ------5 23 180 28 4 DO 4 ' 7.8 10.4 9.4 12 9.2 13.3 11. 7 9 BOD 4 2.4 3.1 2.5 12 0.3 11.0 3.0 9 Fe 0 ---- -- 3 0 1120 2 4 Ca 4 40 85 66 11 24 210 104 8 Mg 4 67 I 30 82 11 5.8 190 68 8 TH 4 420 750 480 II 110 1300 540 8 II a 4 560 960 B40 II 35 1000 450 8 K 4 7.5 12 9.5 9 6.5 12 11 4 SAR 4 11 18 16 11 1.5 16 9.0 8 HC0 3 4 38B 664 583 11 89 913 501 8 TA 4 370 545 508 11 73 749 411 8 so. 4 1200 2400 1700 11 110 2400 1500 B Cl 4 16 27 22 II 4.7 39 20 8 F 4 0.4 0~6 0.5 9 0.1 0.6 0.4 6 I II 4 0.01 0.07 0.03 II 0.04 0. 32 0.13 B ! p 4 0.02 o:. 14 0.07 11 0.01 0. 37 0.07 8 IIOTE: in m~/1. ~1arch-Apri 1 May-July Hin Max Med II Min t1ax ~ed 2.30 76 4.2 7 1.6 19 3.2 0.0 14.0 7.0 8 13.0 27.8 21.3 7.90 8. 5 8. 30 8 8.00 B. 70 8.4 680 4750 3210 8 650 4230 3910 379 4210 2707 7 480 4030 2960 15 400 33 7 6 210 18 38 93 64 3 23 380 51. 2 10.6 13.0 11.0 6 7.0 11.2 8. 5 0.0 7.B 3.6 4 I. 3 3.0 ?..0 so 260 122 1 ----110 33 190 112 B 39 170 110 28 230 98 8 13 210 155 200 1400 6B3 8 152 1300 940 54 840 529 8 82 820 633 7.0 12 10.2 5 10 12 11 1.7 10.8 9.0 8 2. 9 11.8 9.8 131 613 470 B 134 588 454 107 503 390 B 110 482 393 180 2400 1472 8 205 2500 1800 4.8 260 20 8 5.5 29 23 0.2 0.4 0.3 6 0.3 0.4 0.4 0.01 0.17 0.07 8 0.0 0. 12 0.01 0.01 0.51 0.03 8 <.01 0.09 0.04 -----· ---~-- was especially noticeable in the moderately saline east and west forks of Anne 11 s Creek. For the most part, Anne 11 s Creek was much more sa 1 i ne than Sarpy Creek. Annells Creek was slightly saline at its mouth and demonstrated a downstream improvement in water quality and a decrease in TDS concentrations. The inverse relationship between flow and TDS was not well defined in Annells Creek, and, as a result, lowest TDS concentrations were not necessarily ob- tained during high-flow periods. This marking of flow-TDS relationships seems typical of small prairie streams. Like Sarpy Creek, Annells Creek had a sodium sulfate composition which tended to become more pronounced downstream; this can be shown by the mean (Ca + Mg):Na and HC03:SD4 ratios from each station as follows in table 70. TABLE 70. Mean (Ca + Mg):Na and HC03:so 4 ratios from the mouth and east and west forks of Annells Creek. Mouth East Fork West Fork (Ca + Mg) :Na 0.35 1.57 0.47 0. 31 0.27 0.19 Calcium-magnesium and bicarbonate were secondary ions in Annells Creek, and fluoride, chloride, and potassium were insignificant components. Due to the low (Ca + Mg):Na ratios, SAR values in Annells Creek were much higher than those in Sarpy Creek, creating a low-medium (east fork) to medium-very high (west fork and mainstem) sodium hazard for irrigation. Chloride levels were somewhat higher than those in Sarpy Creek, and sulfate concentrations were es- pecially high in the more eastern stream. Magnesium concentrations generally exceeded calcium levels in the upper drainage of Annells Creek, and Ca:Mg ratios then declined downstream to the creek's mouth. The high TDS and constituent concentrations in Annells Creek would be ex- pected to affect many of the water uses described for Sarpy Creek. The west fork water would be poor or unfit as a source for stock animals, and waters in the east fork and mainstem would of only fair quality for this use (California WRCB 1951). None of these waters should be used for poultry. The high sulfate and bicarbonate concentrations in the creek would further degrade the water as a source for stock animals since these constituents exceeded limiting levels (tables _10-14). Also as a result of these features, Armells Creek, with its very hard water, would be particularly unsuitable as a source for municipal supply. In tenns of irrigation, Annells Creek would have a poor quality, Class Ill water due to high SAR, sulfate, TDS, and specific conductance (very high salinity hazard) levels (tables 15 and 16). Boron, however, should not affect this use (<1 mg/1). Thus, the water in this creek would not be applicable to variety of salinity-sensitive and semi-tolerant crop and forage species as summarized in table 17. In addition, the high TDS levels would be expected to have an adverse effect on the aquatic biota (Ellis 1g44). TSS concentrations in Annells Creek were not high in comparison to many other streams. They were generally similar to those in Sarpy Creek, and 167 median values were less than those observed in the Yellowstone River. Occasion- ally high values were obtained in correspondence to high flows, but TSS would not be expected to have as great an effect on the aquatic biota as would salin- ity. Armells Creek has been designated a warm-water, B-D3 stream by the State of Montana; however, like Sarpy Creek, its water quality does not appear to conform to the water-use description of this classification, due primarily to high salinities. Dissolved oxygen, pH, fecal coliform, and temperature levels were generally in accord with this classification. BODs levels in Armells Creek did not indicate organic pollution; this was generally substantiated by the high DO saturations (tables 71-73). In addition, Armells Creek did not appear to be eutrophic as it had low inorganic nitrogen concentrations (tables 67-69) during all seasons. Phosphorus concentrations were also low, and median values exceeded the P criteria only at certain sea- sons in the east fork and mainstem of Armells Creek. Thus the creek appeared to be N-limited. However, high inorganic nitrogen and ammonia levels (tables 71-73) were occasionally obtained, but only in samples from the east fork; this segment of Armells Creek was directly associated with strip mining activities. Median ammonia concentrations were not at levels high enough to alter the eutro- phic status of the stream or to be toxic to aquatic organisms. A variety of trace elements were analyzed in the Armells Creek samples as a result of the stream's juxtaposition to strip mining and electrical generating facilities. With the exception of silica (concentrations were below levels typical of surface waters, Sr, and ammonia, trace elements in Armells Creek can be separated into six groups on the basis of their maximum and median, TR and dissolved concentrations in relation to the water quality criteria. The six classes, ranked according to their potentials to detract from water quality, are summarized in table 74. As seen in tables 71-73, most of the trace elements, except those in Group I on table 74, were detected in at least a few of the samples. In some instances, constituents were detected in a large percentage of the collections and were found in high concentrations .. As observed in other streams, Al, B, Fe, Mn, Sr, and V were most noticeable. However, the high concentrations of many consti- tuents were generally obtained in the TR form with dissolved levels comparativ- ely low. Therefore, most of the trace elements, including ammonia and stron- tium, would not be expected to detract from the water quality of Armells Creek (that is, the trace elements included in Groups I through IV in table 74). Of the 29 trace elements, Ba, Fe, Hg, and Mn may cause occasional water quality problems at particular locations, as dissolved levels sometimes ex- ceeded certain reference criteria. In the upstream reaches, mercury may some- times influence the aquatic biota (table 19), and barium may detract from the value of downstream waters as a source for irrigation. However, iron and manganese are probably more obvious problems to the creek's use; iron could affect the aquatic biota and lower the value of the stream as a surface water public supply, and manganese could detract from its potential for irrigation (tables 15 and 16) and human consumption. The poor water quality in Armells Creek is caused primarily by its extremely saline nature, which probably exerts a more direct effect on water use than do any of the trace elements. 16B TABLE 71. Summary of miscellaneous constituent and trace element concentrations measured in the Armells Creek drainage. East Fork Armells Creek West Fork Arme 11 s Creek Miscellaneous Mi see 11 aneous constituents and Total recoverable constituents and Total recoverable DDa NH 3-N Si B Cd Cu Fe Mn dissolved metals metals N Min Max Med N Min 15 67 205 90 16 0.0 1.1 0.14 16 1.4 17 7.5 16 0.12 0.97 0.71 18 <.001 17 <.01 15 0.02 0.16 0.06 18 0.08 17 <.01 NOTE: Measurements are expressed in mg/1. aDO expressed as·percentage of saturation. Max 0.02 0.04 2.7 3.0 Med <.01 0.01 0.45 0.18 dissolved metals metals N Min Max Med N Min Max Med 16 49 103 87 16 0.02 0.11 0.04 16 1.0 19 8.4 16 0. 13 0.71 0.51 9 <.001 0.03 0. 01 9 0.01 0.03 0.01 16 0.01 0.42 0.05 .9 0.23 0.92 0.54 9 0.05 0.80 0.13 TABLE 72. Summary of trace element concentrations measured in the Armells Creek drainage. East and west forks East and west forks Dissolved metalsa Total recoverab 1 e meta 1 s N Min Max Med N Min Max Med Ag 2 <.002 <.004 <.004 Al 3 0.0 .03 .01 10 .02 .30 . 14 As 3 .001 .002 .001 16 0.0 .006 .001 B 5 .21 .75 .40 Ba 2 .02 .06 .04 Be 3 0.0 . 01 .01 17 0.0 0.01 <.01 Cd 3 0.0 . 001 0.0 Co 3 .07 .08 .07 Cr 3 0.0 . 01 .002 18 0.0 .04 . 01 Cu 3 0.0 .016 .001 Hg 3 0.0 .0001 0.0 25 0.0 . 001 .0003 Li .2 .05 . 10 .075 17 <.01 0. 13 0.05 Mn 3 0.0 .25 .04 Mo 2 .002 .002 .002 14 0.0 .003 .001 Ni 3 0.0 .004 .004 14 0.0 . 15 <.05 Pb 3 .002 .004 .003 16 0.0 . 100 <.100 Se 2 0.0 0.0 0.0 17 0.0 .004 0.0 Sr 2 1.7 5.0 3.4 v 2 .0016 .0017 .0017 3 .42 . 71 .50 Zn 3 . 01 .02 .02 23 0.0 . 14 . 01 NOTE: Measurements are expressed in mg/1. aGa: <.03, N=2; Bi, Co, Sn,' Ti: <.04, N=2; Ge, Zr: <.05, N=2. 170 TABLE 73. Summary of miscellaneous constituent and trace element concentrations measured in Armells Creek near Forsyth. Mi see 11 aneous constituents and dissolved metalsa Total recoverab 1 e meta 1 s N Min Hax Med N Min Max Med oob 22 69 137 95 NH3-N 22 0.0 0.16 0.04 Si 22 1.2 14 6.9 Al 2 .01 . 01 . 01 6 .21 2.2 .64 As 2 .001 .002 .002 14 0.0 <.01 .002 B 22 . 14 .60 .47 5 <.10 0.58 0.20 Ba 2 .082 .100 .091 Be 2 0.0 <.01 <.01 15 0.0 0.02 <.01 Cd 19 <.001 0.02 0.01 Co 4 .03 .08 .07 Cr 2 <.01 0.01 0.01 16 0.0 .064 0.01 Cu 2 .001 .003 .002 19 <.01 0.30 0.01 Fe 22 0.0 . 51 .03 19 . 16 9.7 .75 Hg 18 0.0 .004 .0002 Li 2 .03 .04 .04 15 <.01 0.06 0.03 Mn 2 .06 .21 . 14 17 .03 .33 . 19 Mo 2 <.006 <.006 <.006 11 0.0 .005 .002 (. 002) Ni 2 .003 .006 .005 11 <.05 0.10 0.05 Pb 2 0.0 .003 .002 13 <.01 0.10 <. 10 Se 15 0.0 0.001 <.001 Sr 2 1.5 '2 .6 2. 1 v 2 <.008 <.008 <.008 3 .03 .72 .39 ( .0023) Zn 2 <.01 0.02 --14 <.01 0.04 0.02 NOTE: Measurements are expressed in mg/1. a Cd, Se: 0.0; Hg: <.0001; Ag: <.002; Co, Ga, Sn, Ti: <.02; Bi, Ge: <.03; Zr: <.04; N=2. boo expressed as percentage of saturation. 171 TABLE 74. Trace elements in Armells Creek grouped according to their maximum and median, TR and dissolved concentrations in relation to water quality criteria. Group a TR Dissolved Comments Max Med Max Med I Undetected Undetected No problems anticipated. I I < < < < No problems anticipated. III > < < < Water quality problems doubtful. IV > > < < Low probability of continuous problems. v > > > < Occasional water quality problems. VI > > > > High probability of continuous problems. NOTE: TR and dissolved concentrations of the trace elements within each group were either greater than (>) or less than (<) corresponding water quality criteria. aThe trace Group I Group I I Group I I I Group IV Group V elements belonging to each group ar~ the following: Ag, Bi, Ga, Ge, Sn, Ti, and Zr at all stations As, B, Be, Li, Mo, and Se at all stations; Ba and Cr in the east and west forks; and Zn in the mainstem near Forsyth Cu, Ni, and Pb at all stations; Zn in the east and west forks; and Cr in the mainstem near Forsyth Al, Ce, Co, and V at all stations; Fe in the east fork; and Hg in the mainstem near Forsyth ~g and Mn in the east and west forks; Fe in the west fork and 1n the mainstem near Forsyth; and Ba in the mainstem near Forsyth Group VI r~n in the mainstem near Forsyth MISCELLANEOUS TRIBUTARIES AND SUNDAY CREEK Several other small streams join the Yellowstone River between the Bi and Powder rivers. Overall, the flows of these streams are smaller and are expected to have only a minor influence on mainstem water quality. Because these miscellaneous creeks are not directly affected by coal mining activities, very little water quality information has been collected from them other than that obtained from eight streams by the state WQB (Karp and Botz 1975, Karp et al. 1975b, Montana DNRC 1974). Due to the scarcity of data, this information 172 was coordinated by combining streams into three groups as follows (USDI lg68): 1) small tributaries north of the Yellowstone River between Bighorn and Miles City--Starve-to-Death, Great Porcupine, and Little Porcupine creeks; 2) small tributaries south of the mainstem between Bighorn and Miles City--Reservation, Smith, Sweeney, and Moon creeks; and 3) Sunday Creek near and northeast of Miles City. A few of these streams have rather extensive drainage areas; Sunday Creek pro- bably has the largest discharge. Data for Sunday Creek were adequate for a flow-based classification of information, although this was not possible for the other streams. These miscellaneous tributaries and Sunday Creek have been designated B-D3 streams. As indicated in tables 7S-78, the streams' pH ranges, temperature characteristics, fecal coliform levels (except in Sunday Creek), and dissolved oxygen concentrations were generally in accord with this classification. High fecal counts were obtained from Sunday Creek, which frequently (in four of seven samples) showed levels in violation of state criteria. The origin of these fecals is unknown, but they were probably derived from animal sources, judging from the remoteness of Sunday Creek's drainage area. Overall BODs concentrations were also high in Sunday Creek and in the other northern tributaries. This was not true of creeks draining the more southern regions of the Yellowstone Basin. The high BODs levels were probably natural, considering the sparse human populations in the Bighorn-Miles City area. Most of these streams are probably non-eutrophic with very low median phosphorus concentrations and low nitrogen levels; however, occasionally high values of these parameters were obtained in some samples. The only exception was Sunday Creek, which tended towards eutrophy during low-flow periods. The waters in Sunday and the Group I and II creeks (table 74) had a sodium sulfate composition with bicarbonate as the secondary anion. Calcium concen- trations significantly exceeded magnesium levels. This, coupled with the high chloride concentrations in the northern tributaries (including Sunday Creek), suggests different geologies in the northern and the southern drainages of these streams. Sunday Creek is particularly noticeable in having high chloride concentrations, which significantly exceeded the creek's Ca + Mg levels. This is a unique feature among the streams inventoried so far in this report, and suggests different rock formations in the northern portions of the Yellowstone Basin. However, fluoride and potassium concentrations were again low in these small tributaries and did not indicate water ~uality problems. Similarly, TR trace element concentrations in the Group I and II streams (tables 7S and 76) and in Sunday Creek (tables 77 and 78) were generally similar to those found in Armells Creek. High concentrations of certain constituents were occasion- ally obtained in excess of certain reference criteria (e.g., Co, Fe, Hg, Mn, V, and Zn), but in general, median TR levels indicated low dissolved concentrations and did not suggest difficulties in water use. Iron, which had significantly high TR levels in some samples, may be the major exception. Data were insuf- ficient to describe the status of mercury in this regard. 173 TABLE 75. Summary of the physical parameters measured in small tributaries to the Yellowstone River between the Bighorn and Powder rivers. Tributaries to the n~rth Tributaries to the south of the Yellowstone River in mg/1 of the Yellowstone Riverb in mg/1 N Min Max Med N Min Max Med Flow 12 0.0 lOE 0.5 9 0.17 1.47 0.79 Temp 11 0.0 17.7 13.0 9 0.0 19.5 9.2 pH 12 6.60 8.20 7.75 9 7.50 8.60 8.30 sc 19 lOll 6290 2165 9 807 2200 1918 TDS 12 695 4100 1684 9 606 1778 1530 Turb 10 6 350 17 9 1 340 12 TSS 10 6.5 824 36.3 9 3.5 482 21.5 DO 6 9.8 12.0 10.5 9 8.4 12.9 10.7 BOD 6 3. 1 8.2 4.2 9 1.1 10. 1 2.6 FC 6 0 80 4 8 0 460 4 Ca 12 51 465 131 9 39 98 57 Mg 12 11 248 63 9 0.0 6g 34 TH 12 174 1598 588 9 101 530 266 Na 12 45 800 328 9 116 431 278 K 4 11 25 15 0 ------ SAR 12 0.9 8.8 5.8 9 3.8 11.7 7.7 HC03 12 18 451 249 9 218 608 458 TA 12 15 370 205 9 179 516 375 so4 12 410 2950 1067 9 205 745 648 Cl 12 3.6 34g 33 9 0.0 15 8.3 F 7 0.3 2.7 0.5 5 0.3 0.9 0.5 N 12 0.0 1.88 0.08 8 0.0 0.43 0.06 p 12 0.0 0. 10 0.01 9 <.01 o.og 0.01 aTwo samples from Starve-to-Death Creek, five samples from Great Porcupine Creek, and five samples from Little Porcupine Creek. bThree samples from Reservation Creek, two samples from Smith Creek, two samples from Sweeney Creek, and two samples from Moon Creek. TABLE 76. Summary of the total recoverable metals measured in small tributaries to the Yellowstone River between the Bighorn and Powder rivers. N ·Min Max Med As 2 <.01 < .01 <.01 B 4 . 15 1.4 .34 Be 2 <.01 <.01 <.01 Cd 14 <.001 <.01 0.001 Co 2 .05 .07 .06 Cr 2 .03 .04 .035 Cu 14 <.01 0.02 <.01 Fe 14 . 16 6.5 . 52 Hg 13 <.001 0.002 <.001 Li 2 <.01 <.01 <.01 Mn 11 <.01 0.50 0.06 Pb 3 <.01 <.01 <.01 Se 2 <.001 <.001 < .001 v 2 .46 .63 .55 Zn 14 <.01 0.04 0.01 174 TABLE 77. Summary of the physical parameters measured in Sunday Creek near Miles City. Flm~ less than· 9 cfs. Flow greater than 9 cfs. N Min Max Med N ~1i n Max ~1ed Flow 6 0.0 8. 7 2.04 5 lOE 198 50E Temp 6 0.5 30.1 9. 1 5 5.0 23.5 13.5 pH 6 7. 13 8.89 8.00 ·s 7.50 8.62 8.30 sc 6 623 2550 1148 5 345 3274 1610 TDS 6 427 1948 826 5 422 2021 1103 Turb 5 4 250 35 5 10 3000 210 TSS 6 10.0 358 52.3 5 7.0 5650 1004. DO 6 8.1 12.2 11. 1 3 8.9 11.0 10.3 BOD 5 1.4 > 11 5.4 3 4.2 6.9 4.3 FC 4 0 7000 213 3 0 1030 600 Ca 6 13 64 25 5 15 81 48 Mg 6 4.6 28 8.2 5 1.2 31 17 TH 6 52 269 94 5 43 331 191 Na 6 105 485 220 5 80 563 265 K 3 5.8 6.8 6.5 4 8.1 65 9. 1 SAR 6 5.6 13.4 9.9 5 3.9 13.5 8.2 HC03 6 130 616 224 5 145 290 219 TA 6 106 505 197 5 119 242 180 504 6 103 745 243 5 112 570 332 Cl 6 0.6 374 60 5 10 556 118 F 4 0.2 0.5 0.4 4 0.2 1.4 0.4 N 6 0.0 4.5 0.40 5 0.02 0.69 0. 11 p 6 0. 01 0.59 0.15 5 0. 01 o. 12 0.01 NOTE: Measurements are expressed in mg/1. TABLE 78. Summary of the total recoverable metals measured in Sunday Creek near Miles City. N Min ~1ax Med As 2 <.01 <.01 <.01 B 6 <. 10 0.17 0.11 Cd 9 <.001 0.001 <.001 Cr 1 <.01 Cu 9 <.01 0.08 0.01 Fe g .25 18 1.1 Hg 3 <.0002 <.001 <.001 Mn 9 <.01 1. 06 0.04 Pb 2 <.01 <.05 <.05 Sr 1 .58 v 1 <. 10 Zn g <.01 0.20 <.01 NOTE: Measurements are expressed in mg/1. 175 Levels of TSS and turbidity in the Group I and II streams were generally similar to those in Armells and Sarpy creeks. Occasionally high sediment con- centrations were obtained, probably in association with high flows, but low median values. The median TSS concentrations in these streams indicate an excellent-to-good fishery (European Inland Fisheries Advisory Commission lg65), ignoring the probable effects of high TDS concentrations and low flows. Thus, in these streams, salinity seems to be the major factor degrading water quality. In Sunday Creek, TSS-turbidity levels were significantly higher, parti- cularly at high flows, and noticeably high values were obtained at times--as high as 5.7 mg/1. Considering the low TDS concentrations of the stream, TSS- turbidity may be a major detraction from stream quality, potentially affecting the stream's fishery, if there is one, and lowering the value of the water as a public supply. Salinity also degrades Sunday Creek's water quality. Although high TDS-specific conductance levels were occasionally obtained in samples from these small tributaries, the overall salinities in these Group I and II streams were significantly less than those in the Armells Creek drain- age and generally similar to those in Sarpy Creek near its mouth. The streams with drainages to the south of the Yellowstone River were less saline than those to the north,except Sunday Creek which had the lowest salinity of any small stream in the Bighorn-Miles City portion of the Yellowstone Basin. The masking of the TDS-flow relationship was also evident in Sunday Creek, where TDS and flow, like TSS and flow, appeared to be directly related. Regardless of the lower TDS concentrations, salinities were still at adequate levels in these various streams to potentially influence the aquatic biota and restrict many of the water uses. Effects on aquatic life would be most noticeable in the Group I and II creeks, as median TDS and specific conductance levels were greater than 1350 mg/1 and 2000 vmhos/cm, respectively. Such effects would be lower in Sunday Creek, but TDS and SC levels may still have some detrimental effects with levels at 670 mg/1 and 1000 vmhos/cm. Using TDS as a measure .of quality, the 1·1aters in these streams would pro- bably be good for application to all stock animals (Seghetti 1951), particularly in Sunday Creek where median sulfate concentrations were low. Sulfate levels in the other tributaries, primarily in the Group I streams (tables 75 and 76), however, could degrade the value of the stream for this use because median sul- fate concentrations either exceeded the limiting levels for stock (in the nor- thern tributaries) or exceeded the animals' threshold levels (in the southern tributaries) (tables 10-14). These eight streams would be poor sources of surface water for public supply due to their hardnesses (Bean 1962) and high TDS and sulfate levels. In Sunday Creek (tables 77 and 78), this would account for the occasionally high turbidity, fecal coliform, and chloride concentrations. Boron would not affect the use of the water for municipal supply or irrigation, but the Group I and II tributaries would probably still have a poor quality, borderline Class 1-11 water for irrigation as a result of their high sodium and SAR values (producing a medium sodium hazard), high sulfate concentrations, and high TDS- SC levels (producing a high salinity hazard) (tables 15 and 16). With the generally lower TDS and sulfate concentrations, Sunday Creek would probably have a better Class II water for irrigation. It would not have a Class I water for this use because of its high sodium concentrations and SAR values and its 176 tendency to have high chloride levels. In general, these streams have a poor- to-fair water quality. ROSEBUD CREEK DRAINAGE Rosebud Creek Mainstem Rosebud Creek is a large tributary in eastern Montana that joins the Yellowstone River between Forsyth and Miles City (USDI lg68). Its flow is significantly smaller than that of the Bighorn River, but it has a larger dis- charge than many streams east of Myers. Rosebud Creek does not have a sub- stantial effect on mainstem quality judging from the fact that there is no real change in Yellowstone water chemistry between Forsyth and Miles City (tables 56 and 57). Due to the higher flows, Rosebud Creek is a more suitable source of water for uses such as irrigation than the smaller Bighorn-Miles City streams. As a portion of the Rosebud drainage lies very close to the Colstrip strip mining development, particularly the Peabody mine, an extensive water quality sampling program was recently initiated by the USGS on the creek (USDI 1976). The USGS maintains four sampling stations on the stream (table 3); to expand the data base and to facilitate this review, water quality information from these sta- tions was combined to represent two reaches of the creek--a middle reach in close association with Colstrip, and a lower reach near the stream's mouth near Rosebud. Data available from the state WQB for Rosebud Creek (Karp and Botz 1975, Montana DNRC 1974) were combined with the USGS information, and these data were sufficient for a seasonal classification. In addition, some data are also available from the state WQB for an upper reach of the creek near its headwaters in the Rosebud Mountains, upstream from Busby. The data for this upper segment were flow-classified, as shown in tables 79 and 80. The water quality in upper Rosebud Creek was good compared to other tri- butaries in the Bighorn-Powder rivers portion of the Yellowstone Basin. Dis- solved concentrations were much lower, and TDS levels were similar to those obtained from the Bighorn and Tongue rivers (table 48). However, TDS concen- trations in this segment were about 20 percent to 110 percent higher than those in the Yellowstone River near Forsyth, depending upon season, and they were found to be a magnitudes sufficient to degrade this reach as a surface water public supply (i.e, median TDS values were greater than the standards for this parameter and water use as summarized in table 9). According to the EPA (lg76), waters with TDS concentrations between 500 mg/1 and 1000 mg/1 can have detri- mental effects on sensitive crops. The stream's salinity also could have a mild effect on the aquatic biota in this segment--median values were between 4DO mg/1 and 670 mg/1. In contrast, the upstream waters were excellent for the watering of all stock animals, and this reach for the most part probably has a good Class I water for irrigation, as it has low boron, SAR, chloride, sulfate, and SC-TDS levels. The stream had a low sodium hazard and a medium-high salinity hazard for irrigation (USDA 1954). 177 TABLE 79. Summary of the physical parameters measured in the upper reach of Rosebud Creek near Kirby-Busby. Less than 23 cfs. Greater than 23 cfs. N Min Max Med N Min Max Med Flow 5 5.7 22.7 11.2 2 63.B 75.6 69.7 Temp 5 0.0 18.0 0.0 2 0.0 11.8 5.9 pH 5 8.00 8.40 8.30 2 7.60 8.30 7.95 sc 5 760 997 785 2 485 805 645 TDS 5 613 851 672 2 363 705 534 Turb 4 2 10 8 2 2 78 40 TSS 4 9 28 15 2 25.9 254 140 DO 5 7.9 12.9 11.3 2 9.8 11.6 10.7 BOD 5 1.7 4.3 3.2 2 3.0 ---- (11.4?) FC 5 2 7700 41 2 30 480 255 Ca 5 58 88 72 2 47 66 57 Mg 5 41 73 57 2 19 60 40 TH 5 381 473 403 2 197 412 305 Na 5 11 46 23 2 18 28 23 K 0 ------0 -- -- -- SAR 5 0.2 0.9 0.5 2 0.6 0.6 0.6 HC0 3 5 367 472 431 2 213 429 321 TA 5 315 387 357 2 175 352 264 SD4 5 85 189 118 2 61 118 90 Cl 5 0.3 1.6 1.5 2 2.5 3. 1 2.8 F 2 0.5 D.5 0.5 1 ----0.2 N 5 0.01 0.21 0.05 2 0.03 0.25 0.14 p 5 0.01 0.07 0.02 2 0.03 0.17 0.10 NOTE: Measurements are expressed in mg/1. TABLE 80. Summary of total recoverable metals measured in the upper reach of Rosebud Creek near Kirby-Busby. N Min Max Med As 5 <.01 0.01 <.01 B 1 .07 Be 1 <.01 Cd 7 <.001 <.01 <.01 Co 1 . 01 Cr-3 <.01 <. 01 <.01 Cu 7 <.01 0.01 <.01 Hg 4 <. 001 <.001 <.001 Fe 7 .08 3.2 .44 Mn 2 .08 . 21 . 15 Pb 5 <.01 <.01 <.01 Se 1 <.001 v 1 .09 Zn 6 <.01 0.01 0.01 NOTE: Measurements are expressed in mg/1; Li: <.01, N=l. 178 None of the major ionic constituents had concentrations high enough to degrade any water uses. Trace elements, also, showed low concentrations (tables 79 and 80), except the high TR iron and manganese concentrations. The high TR iron and manganese concentrations could affect the aquatic biota (table 19), and, in combination with the hardness of the water, could detract from the domestic use of the upper stream. The chemical composition of upper Rosebud Creek was somewhat different from other streams in the Bighorn-Miles City segment of the Yellowstone drain- age (USDI 1968). The waters were calcium bicarbonate, indicating limestone formations in the Rosebud Mountains, and magnesium and sulfate were secondary ions. Calcium concentrations were significantly higher than magnesium concen- trations. Chloride and fluoride were insignificant constituents, and sodium concentrations were also low. Such low sodium concentrations produced parti- cularly low SAR values considering the extremely hard nature of the water. However, several downstream changes in the chemical composition of Rosebud Creek made the lower segment more consistent with other Bighorn-Miles City tri- butaries. Apparently, intermediate inputs to Rosebud Creek, geographically on line with the upper Armells, Sarpy, and Tullock creek drainages; have similar water quality. Fluoride, chloride, and potassium continued to be insignificant constituents, but the waters in Rosebud Creek tended to become more sodium sul- fate in character downstream, with higher SAR values and with such great in- creases in magnesium that magnesium levels exceeded calcium concentrations in the lower segments (tables 82 and 83). This trend towards a sodium sulfate water became most noticeable in the extreme lower reach of Rosebud Creek near its mouth, as indicated in table 81. TABLE 81. Low-flow and high-flow levels of (Ca + Mg):NA, ~a:Mg, and HC03:so 4 in Rosebud Creek. (Ca + Mg) :Na Ca:Mg HC0 3 :S0 4 Low High Low High Low High Flows Flows Flows Flows Flows Flows Upper Rosebud 5.61 4.22 1.26 1.42 3.65 3.57 Middle Rosebud 2.41 2.89 0.87 0.96 l. 61 1.82 Lower Rosebud 1.80 l. 74 0.81 0.87 l. 30 1.48 Such downstream changes were less noticeable during the high-flow period when runoff from the Ros-ebud Mountains would be greatest. Rosebud Creek has been classified a B-D3 stream by the State of Montana (Montana DHES, undated). This designation is appropriate for the high maximum warm-weather temperatures of this stream in its lower reaches, and its pH and dissolved oxygen levels in all segments. The lower pH values were most con- sistently obtained in the winter rather than during the May-July runoff period. In the upper reach, however, lowest values were obtained in conjunction with the higher flows. As observed on almost all of the streams in the Yellowstone Basin, DO concentrat1ons were highest during the cold-weather periods and lowest during the summer in association with the high water temperatures. Occasionally, 17CJ TABLE 82. Surrrnary of the physical parameters measured in the middle reach of Rosebud Creek near Colstrip. August-October November-February ~lclrch-Apri 1 May-July II t-tin Max fled II ~lin ~ldX Med II t·1in Max Med N Min Max Med Flow 9 15 52 36 19 18 IOUE 32 II 24.5 236 6~ 12 55 258 110 Temp 9 7.5 20.5 16.0 20 0.0 4.5 0.0 13 0.0 13.5 0.5 13 9.5 24.0 19.5 pH 9 a. 3 8.8 8.4 20 7.5 8:4 8.05 13 7.5 8.9 8.30 13 8.1 8. 70 8. 3 sc 9 930 150_0 1060 20 699 1860 1315 13 310 1400 1230 \3 900 1900 1000 TDS 9 707 841 782 19 523 1040 899 12 198 1150 846 13 627 886 703 Turb 9 7 80 20 19 5 20 10 13 8 190 60 12 46 200 115 TSS 0 -----. 5 8.0 36 20.8 5 13.5 597 254 1 ----112 DO 9 6.2 11.2 8.1 20 7.0 12.8 11.5 11 9.2 13.0 10.1 13 6.6 9. 7 7.6 (2.8?) BOD 3 1.0 2.6 1.2 10 0. 2 9.3 0. 7 9 0.6 4.1 3.1 6 1.5 2.9 2.4 rc 0 ------3 2 100 20 4 4 40 21 1 ----20 Ca 9 62 80 66 19 58 104 89 12 28 93 80 13 56 82 75 Mg 9 79 98 90 19 34 120 95 12 19 110 86 13 68 89 78 HI 9 490 590 540 19 286 730 610 12 150 690 560 13 470 570 500 :la 9 56 86 66 19 31 98 75 12 13 120 69 13 44 72 53 K 9 8.7 12 10 17 9.1 11 10 8 8. 7 12 9.1 12 7.3 9.0 8.0 (1.1?) SAR 9 1.1 1.6 1.2 19 0.8 1.6 1.4 12 0.5 2.0 1.3 13 0.9 1.4 1.0 ,IIC0 3 9 411 504 438 19 254 617 551 12 132 520 483 13 376 472 455 TA 9 350 425 365 19 209 506 452 12 108 427 396 13 322 387 373 504 9 250 350 270 19 140 430 327 12 54 560 314 13 190 330 250 Cl 9 4 6 5 19 3.0 7.4 6 12 1 7 4.0 13 3.0 13 4.0 r 9 0.5 0.7 0. 6 18 0.3 0. 6 0.6 8 0.2 0.7 0.6 12 0. 4 0. 6 0. 5 II 9 0.0 0.02 0.01 19 0.0 0.37 0.2 13 0.0 0.23 0. I 13 0.0 0.42 0. IS p 9 0.03 0.15 0.07 19 0.0 0.11 0.04 13 0.02 0.23 0.06 13 0.02 0.41 0.18 tiOTE: i·ledsuref!ents expressed in rng{l. ..... 00 ..... TABLE 83. Summary of the physical parameters measured in the lower reach of Rosebud Creek near Rosebud. August-October Novcmbe r-F ehrua ry March-Apri 1 II Min Max l~ed II l·lin Max Med N ~11 n ~1ax Mod Flow 13 4 55 31 19 14 180 36.9 12 30.6 244 70 Temp 12 6.0 22.6 12.0 22 0.0 3. 5 0.3 16 o.o 14.2 3.0 pH 13 8.3 8.50 8.40 19 7. 40 8.4 8.0 14 7.6 8.50 8. 3 sc 13 1000 1598 1230 19 584 2060 1500 14 330 1550 1177 TOS 13 710 1345 891 18 419 1210 946 13 215 1100 943 Turb 12 5 800 50 18 15 300 28 15 12 240 100 TSS 2 19 96.2 57.6 7 22 200 52 8 33 2620 194 DO 10 5. 9 11.4 8. 5 19 9.0 13.0 12.1 14 9.8 12.6 11.4 BOO J 1.2 3.8 2. 2 7 0.2 2.7 1.5 10 0.7 4.9 3.3 ( 11.61) FC 0 ------2 16 240 128 6 0 170 62 Ca 1 J 51 135 71 18 49 110 82 13 26 87 66 Mg 13 72 100 91 18 13.3 120 96 13 17 100 81 TH 13 470 634 560 18 183 770 595 13 140 630 510 Na 13 69 155 90 18 47 140 91 13 21 140 90 K 11 8.8 14 11 17 8.9 11 10 8 6.9 12 3. 7 SAR 13 1.4 2.8 1.7 18 1 .4 2.2 1.7 13 0.8 2.5 1.7 IIC0 3 13 336 504 469 18 163 636 486 13 133 540 417 TA 13 326 429 385 18 134 522 415 13 109 443 358 504 13 270 495 340 18 137 490 380 13 fi2 550 338 Cl 13 4. 1 8.0 6 18 4 8 6 13 2.6 6.3 4.8 F 13 0.5 0.7 0.6 17 0.3 0.7 0.6 8 0.2 1.1 0.5 II 13 0.01 0. 34 0.02 18 0.01 0. 31 0.07 13 0.0 0.22 o. 13 p 13 0.01 0. 75 0.08 18 0.02 0.40 0.06 13 0.01 0. 31 0.08 riOTE: Measuremenls expressed in mg/1. May-July II Min Max Hed 15 29 905 109 20 10.0 27.8 18.5 18 7.88 8.70 8.30 18 580 1538 1059 17 378 1268 841 17 38 2500 180 8 97.3 5100 311 16 3.9 9.6 8. 3 8 0.8 6.1 1.8 3 70 135 100 17 25 85 69 17 12 102 79 17 110 600 500 17 51 150 85 15 5.0 13.5 8. 3 17 1.0 3.8 1.5 17 187 484 445 17 153 397 376 17 140 505 300 17 3.0 7.3 4.7 15 0.3 0.6 0. 5 1 7 0.0 0. 5 0. 20 17 0.01 0.67 0.14 (2. 3') unexpectedly low DO concentrations were obtained, but these instances appeared to be correlated with extremely high TSS concentrations and high settleable solids contents (e.g., the May-July data in table 83) rather than with organic discharges. In general, median BODs levels did not indicate organic pollution, and only 16 percent of the samples nad BODs levels greater than 3.g mg/1. These occasionally high BODs values, approaching 10 mg/1, were probably natural (as in Beauvais Creek) rather than the result of man's activities. DO percentage- of-saturation data indicated no extensive organic inputs to Rosebud Creek; only 17.5 percent of the samples had DO concentrations less than 8S percent saturation, and less than 10 percent had DO levels less than 80 percent saturation. In addition, median DO concentrations in Rosebud Creek were greater than 90 per- cent of saturation (table 84). Thus, temperature, pH, BODs, and DO levels in Rosebud Creek do not seem to detract from the quality of its water. Although I fecal coliform concentrations were high in some samples from Rosebud Creek, median values were generally in line with the state's average criteria (except the upper station at high flows), and only 8 percent of the samples had fecals in excess of the state standard for grab samples (all from the upper reach). As a result of these features, and because Rosebud Creek is non-eutrophic and N-limited, the high total solids concentrations, particularly in the lower seg- ments, appear to be the major water quality problems in the stream. Dissolved solids concentrations in Rosebud Creek tended to increase down- stream to its mouth, probably due to its extensive prairie drainage system below Busby. An increase in median TDS of 31.6 percent occurred during high flows between the upper segment above Busby and the middle reach near Colstrip, with a 16.4 percent to 33.7 percent increase during the low-flow periods. An increase of about S7.3 percent at high flows and between 32.6 percent and 40.8 percent at low flows developed through the entire length of the stream to its lower reach near Rosebud. These TDS increases were caused primarily by in- creasing Mg, Na, and so 4 concentrations; increases inCa and HC0 3 were small, and K, Cl, and F continued to be insignificant constituents in tne lower stream. Suspended solids also tended to increase downstream, mostly near the creek's mouth at low flows (table 83). All of these features indicate a downstream degradation in water quality and additional restrictions on water use. For example, although TSS concentra- tions were high at high flows in the upper segment above Busby (tables 79 and 80), the overall median TSS level in this segment (22 mg/1) indicated an excel- lent fishery (European Inland Fisheries Advisory Commission 196S). In the lower reach, however, an annual median TSS concentration of 142 mg/1 indicates only a fair fishery (European Inland Fisheries Advisory Commission 196S). In turn, the greater downstream salinities with TDS generally in excess of 670 mg/l are another source of degradation to the Rosebud fishery. That is, TDS and SC levels in the middle and lower reaches of Rosebud Creek were at levels suffi- cient to suggest adverse effects on the aquatic biota, although these effects would be small with TDS and SC less than 1350 mg/1 and 2000 ~mhos/em. The water in lower Rosebud Creek was of lesser quality for municipal supply than that upstream as a result of·the high TDS and sulfate concentrations and the high turbidities. For example, the annual median turbidity uf the lower reach of Rosebud Creek (84 JTU) was much greater than that upstream (about 8 JTU) and greater than the permissible criteria for surface water public sup- plies established by the NTAC (1968). Also, the waters in the lower reaches 182 iASL[ 84 SLJrmlclry o• mlscellaneoLJs cons:.itu~nt and trace f'\cment concentra~ions n-e<.~~LJn'd in t~e mid!ll~ o~nd IO'ofer r~o~c~r·s o! RoseiJLJd Creek Hiadll! reach neo~r Colstrip Lo"'•!r n•ac~ !l!'<lr Rn~!'hLJd Hisccl1aneous ~\1 SCI:! \1 <.IOC'OUS constitLJents e~nd ~~~~~; ~~~n ~t:~~D dissolved rretalsa Toto~\ rt'Co;·t'rdblo! ~t>:~tals Total recove-rable metal~ " I~ in ~lax ""' N ~~ n ''" Mr!d " Mir1 f-1,,. Mr!d " M\11 ... ""' oo' IO ll 118 91 47 G7 Ill % ~HJ-/1 2l 0.0 o. 11 0.02 21 0.0 0.119 0.01 II 45 1.\ , 16 " 7.1 2l " " ' 0.0 .01 .01 IJ .10 8.0 . ~7 ' 0.0 .01 .005 11 . 70 6.' 1.8 ,, 6 .001 . 028 . OOJ 25 0.0 . 018 .002 I 0.0 . 003 .002 25 0.0 .010 .002 8 " .10 .24 .16 2 . I 3 . 2?. .18 46 ·" .23 .18 R .:.Hl 0. ~I 0. 11 ,, J .080 . 110 . 100 3 . 010 .04~ .092 " ' u.o 0.01 < .01 II 0.0 .01 o. a ' rJ.O 0.01 •. 01 13 0.0 0.01 < .01 (d " 0.0 0.02 < .01 34 0.0 0.02 < 01 Co 2 .01 .02 . 015 3 .01 .03 .01 ,, ' 0.0 .: .01 < .01 23 0.0 .02 0.0 ' 0.0 Q,01 •. 01 '" 0.0 .04 .01 '" ' 0.0 .OOJ . 002 " 0.0 .13 .01 ' 0.0 .002 .001 14 < .01 0.06 0.01 ,, " 0.0 .21 . 03 " .ll 16 .II<J ,, 0.0 .16 .02 34 ·" 32 2. I Hg " 0. 0 .001 .0001 19 0.0 .001? .0002 ( < .01} l i ' .050 .055 . 052 10 ~.01 0.06 0.05 ' .o.:.o .056 .052 13 < .01 0.06 0.05 Mn 4 .010 .020 .01~ 25 .02 .60 .06 • 0.0 .03 .03 31 ·" .51 .11 "' 4 < .003 O.OOJ O.OGJ g .002 .21 .001 ' ~ .003 0.00) <.003 I .002 .003 .002 IIi 4 .001 .001 .001 I < .05 0 .OS < .05 4 0.0 .003 .002 10 0.0 0.10 < 01 Pb 4 0.0 .001 .001 25 <.01 0. 10 <. 10 4 0.0 .00) .001 " < .01 0.10 < • 10 Se 1 0.0 .001 . 001 13 0.0 .001 .001 I ----.001 26 0.0 0.001 . .001 ,, J I .I 1.9 1.9 ' 1.1 1.1 1, J J ·" 2.6 1 .J v ' < .003 < .004 0.003 1 . OJ .13 .08 4 < .00! <,004 < ,QOJ 5 < .05 0 . 13 <. 10 '" • 0.0 o.o3 <. 01 10 <.01 0.08 0.02 4 0.0 .02 .01 " •. 01 0. lJ 0.02 IOOTE: P4eaSLJren!n:.~ C"•Pressed in cg/1. <lAg: 001, r-o:J; Bl: •0.10, 11~1; Cd, Co: • .OJ, ~·3; H9: <.0001. 71•4: t.a, Ge. Sn, Ii, lr: <.01, N•l. bAg; 002, N-~; Cd: 0.0. /1=4; Co:~ 02, N•3; H9: <.0001. N~4:•Bl. G.!r, te, Sn. Ii, lr: •.02, N•l. 181 appeared to be of 1 esser qua 1 i ty for i rri gat ion than above Busby, due primarily to the higher TDS-SC levels and salinities--the downstream increases in boron, fluoride, SAR, chloride, and sulfate would not alter the creek's classification. Rosebud Creek becomes a Class II water for irrigation near Colstrip, with a low sodium hazard but with a high salinity hazard, which would restrict its application to certain plant species. However, the downstream water quality would still be good for watering all stock animals (Seghetti 1951). Discharge in lower Rosebud Creek was highest during the Hay-July period, probably caused by snowmelt runoff from its mountainous headwaters, and lowest in the August-to-October winter season. TDS concentrations were lowest during the runoff period (although the higher TSS levels in May-July detract from the better water quality), and highest in the winter. The creek had a secondary flow peak in the spring, probably caused by early runoff from the prairie low- lands. TSS levels were intermediate during this secondary flow peak, and TDS concentrations were high during this March-April period regardless of the great- er flows. This probably stems from the poor water quality associated with low- land runoff in various small prairie streams. As a result, the usual inverse relationship between flow and TDS was not as apparent in Rosebud Creek, and the seasonal changes in median TDS concentrations between _low and high flows were not as great as those in the Yellowstone River. These effects can be seen in table 85, which gives Yellowstone River data comparing stations above Livingston with largely mountainous drainages to those below Billings that are cumulatively affected by prairie inputs. TABLE 85. Seasonal changes in median TDS concentrations between low and high flows in the Yellowstone River. Yellowstone-Corwin Springs Yellowstone-livingston Yellowstone Billings Yellowstone-Miles City Yellowstone-Sidney Rosebud-Rosebud 0March-Apri 1. High Flow: Low Flow 7.84 5.96 5.42 3.50 3.21 3. 51 High Flow TDS: Low Flow TDS 0.46 0.50 0.48 0.54 0.57 o.g4 Spring Flowa: Low Flow 1.05 1.07 1.11 1.22 1.36 2.25 Spring Flow TDS•: Low Flow TDS o.ga 0.98 o.g4 1.05 1.05 1.06 As indicated in table 85, both the seasonal flow and TDS variations declined downstream in the Yellowstone River, showing a direct relationship between spring flow and TDS in the lower reach. Phosphorus concentrations were high throughout Rosebud Creek (tables 79, 80, 82, and 83); this was particularly noticeable in association with the high TSS levels during the high flows. Phosphorus concentrations were usually greater than the reference level for eutrophication during all seasons; 62 percent of 184 the samples had concentrations greater than or equal to 0.05 mg P/1. However, the creek is probably non-eutrophic judging by the low median nitrogen concen- trations; 93 percent of the samp 1 es were generally be 1 ow the reference criteria. Therefore, only 4.5 percent o• the samples from Rosebud Creek would be expected to have both phosphorus and nitrogen in excess of their criteria for eutrophi- cation. Ammonia-nitrogen concentrations were also low (table 84), and probably would not be toxic to the stream's biota or alter the eutrophic status of the creek. The high inorganic nitrogen and ammonia concentrations occasionally observed in other streams and attributed to strip mining activities were not evident in Rosebud Creek. The stream did, however, demonstrate a summer low in nitrogen, and it had a major winter peak in concentrations and a secondary runoff peak in the middle_reach (table 82). The winter maximum in nitrogen was not evident in the lower segment. Many other trace elements were analyzed in samples from the lower two reaches of Rosebud Creek (table 84). To facilitate their review, these consti- tuents were split into the following groups: Group I Ag, Bi, Ga, Ge, Sn, Ti, and Zr in both reaches Group II B, Ba, Be, Co, Cr, L i, and Se in both reaches; Ni and Zn in the middle reach; and Mo in the lower reach Group III Cd, Cu, Pb, and V in both reaches; possibly As (one high dissolved reading was obtained) and Mo in the middle reach; and As, Ni, and Zn in the lower reach Group IV Al, Fe, Hg, and Mn in both reaches In general, trace element concentrations in Rosebud Creek seemed lower than those in Armells Creek (table 84). Practically none of these minor constituents were at concentrations high enough to indicate major water quality problems. This would include silica, strontium, and metals such as Al, Fe, and Mn that were observed in high concentrations in their TR forms. Such high TR concen- trations were probably correlated with the high TSS levels of Rosebud (reek, as the TR concentrations of several metals (particularly Al, Fe, and Mn) in- creased downstream in association with the downstream increase in suspended sediment. Dissolved concentrations, h01~ever, did not increase to the creek's mouth. Of the trace elements, only iron may cause water quality problems. Tributary Streams The state WQB collected samples from four tributaries in the region (tables 86 and 87). All of these streams are located in the southern portions of the Rosebud Creek drainage above Colstrip; the most southern streams had chemical compositions similar to the composition of upper Rosebud Creek above Busby (e.g., the minimum data in tables 86 and 87--Indian Creek). These streams had low TDS-SC levels and a calcium bicarbonate water in which calcium was higher than magnesium, calcium and sulfate were the secondary ions, and sodium concen- trations were high, producing higher SAR values. With the exception of TSS, which was in low concentrations, the median quality of the seven samples col- lected from these streams was most similar to those in the middle and lower 185 TABLE 86. Summary of the physical parameters measured in the Rosebud Creek tribu- tari es near Kirby, Busby, and Lame Deer. N Min Max Med Flow 7 2.0 5E 2.9 Temp 7 0.0 16.3 4.5 pH 7 8.20 8.60 8.30 sc 7 577 1685 1181 TDS 7 485 1477 1034 Turb 7 2 23 7 TSS 7 6 69 21.0 DO 7 9.5 13.5 11.8 BOD 7 1.5 7.5 3.2 FC 7 0 550 12 Ca 7 54 74 65 Mg 7 37 129 86 TH 7 302 696 530 Na 7 11 150 83 K 0 SAR 7 0.3 2.5 1.6 HC03 7 328 652 534 TA 7 269 551 438 504 7 47 462 212 Cl 7 0.2 8.8 3.8 F 1 1.0 N 7 0.0 0.66 0.03 p 7 <.01 0.29 0.04 NOTE: Measurements are expressed in mg/1. One sample was taken from Indian Creek near Kirby, two samples were taken from Davis Creek near Busby, three samples were taken from Lame Deer Creek near Lame Deer, and one sample was taken from Muddy Creek near Lame Deer. 186 TABLE 87. Summary of the total recoverable metals measured in the Rosebud Creek tributaries near Kirby, Busby, and Lame Deer.a Total Recoverable Metals N t~i n Max Med As 4 <.01 <.01 <.01 Cd 7 <.001 <.01 <.01 Cr 2 <.01 <.01 <.01 Cu 7 7 0.01 <.01 Fe 7 <.Ol l. 10 0.25 Hg 5 <.001 <.001 < .001 Mn 6 0.02 0.20 0.05 Pb 3 <.01 <.01 <.01 Zn 7 <.01 0.02 <.01 NOTE: Measurements expressed in mg/1. aOne sample was taken in Indian Creek near Kirby, two samples were taken from Davis Creek near Busby, three samples were taken from Lame Deer Creek near Lame Deer, and one sample was taken from Muddy Creek near Lame Deer. reaches of Rosebud Creek. The tributary waters were non-eutrophic and nitrogen- limited with pH, dissolved oxygen, temperature, fecal coliform, BOD 5 , and trace element levels in accord with state criteria for B-D3 streams. Sal1nity and high concentrations of related constituents appeared to be the primary factors detracting from the water quality in these tributaries. Median TDS-SC levels in these small streams were generally greater than those in Rosebud Creek; e.g., the tributaries had l.Qg to 1.23 times higher median TDS concentrations than the lower reach of Rosebud Creek (table 83), depending upon season. These differences were greater in an upstream direction (tables 79 and 80)--differences of 1.54 to 1.94 times higher were observed above Busy--correlating with the downstream increase in the mainstem below Busby. As a result, the same potential effects of salinity and other ions in Rosebud Creek wou'ld apply more strongly to these tributary streams. For example, although the water in the tributaries would still be good for stock on the basis of TDS (Seghetti 1951), the median bicarbonate concentration was.high enough to further degrade its value for this use; median bicarbonate was greater than 500 mg/1--higher than the limiting level of this parameter for domestic animals (California WQCB 1963). The tributary waters would also be unfit for municipal supply due to the high TDS concentrations and hardness levels; however, lower sulfate concentrations were generally obtained from the smaller streams than in Rosebud Creek. The tributaries provide a less suitable source of water (Class II) for irrigation; they have low sodium hazard (low SAR values) but high salinity hazard for this use. The greater salinities in some of the Rosebud tributaries may also have a slightly greater effect on the aquatic biota than does the main- stem, but the effect would be mild because TDS concentrations were generally less than 1350 mg/1. In turn, the effects of TSS on aquatic life would be minute in the Rosebud tributaries in comparison to the TSS influences pre- dicted for the lower reaches of Rosebud Creek. 1B7 TONGUE RIVER DRAINAGE Tongue River t1ainstem The Tongue River is one of seven major tributaries joining the Yellowstone River in Montana, and one of three major tributaries entering the mainstem east of Billings. The Tongue River's flow is only about 11 percent of the Bighorn's, but its discharge is about seven times greater than Rosebud· Creek's. The Tongue at its mouth at Miles City has an annual average flow of about four percent of that of the Yellowstone at Miles City above their confluence (USDI lg74). Thus, the Tongue River may exert some influence on the water quality in the Yellow- stone mainstem, assuming that it has a significantly lower quality than the bigger stream. This may also apply to the Powder River, located about 39 miles farther east near Terry. The annual average flow of the Tongue and Powder rivers is about 9.5 percent of that of the Yellowstone River at Miles City. The potential cumulative effects of the Tongue and Powder rivers on mainstem quality can be judged by comparing Yellowstone data obtained at Miles City (above the Tongue confluence, table 57) to the Yellowstone data obtained from sampling stations below Terry. Two long-term water quality monitoring stations have been maintained by the USGS on the Tongue River (USDI l966-l974a)--at the state line near Decker (an extreme upstream station where the river enters Montana above the Tongue River Reservoir), and at Miles City (an extreme downstream station near the stream's mouth). About 30 to 50 samples from these two locations have been analyzed each seasonal period for many of the water quality parameters, and the data from these two stations are directly comparable due to their similar per- iods of collection. In addition, the USGS has recently begun sampling three intermediate water quality stations on the Tongue River as summarized in table 3; about four to fourteen samples have been collected from these locations each seasonal period. Data from these intermediate locations are directly compar- able to each other due to their similar sampling periods, but the·y are not as amenable for comparison with the long-term stations which have been sampled over a longer time span. For this review, data from two adjacent and intermediate USGS stations were combined (Tongue River below Hanging Woman Creek near Birney and Tongue River at Tongue River dam near Decker) to represent a segment .of the river immediately below the Tongue River Reservoir. In addition,. considerable amounts of data are also available from the state WQB on the Tongue River and its tri- butaries. The USGS and the state WQB data were further combined to ultimately represent four reaches of the Tongue River as follows (USDI 1976): 1) near Decker above the reservoir (from near the state line to the inflow of the reservoir); 2) near Birney (from the Tongue River dam outflow to near Birney); 3) from near Ashland to the Brandenburg bridge; and 4) from Brandenburg bridge to near the river's mouth. Of special interest in the water quality inventory of this drainage is the Tongue River Reservoir and its potential effect on mainstem quality; it is 188 discussed later in this section. The statistical summary of water quality data from the upper reach of the Tongue River is presented in table 88. The flow pattern in this reach is sim- ilar to the patterns in other streams located near their mountainous head- waters regions (e.g., the Yellowstone River near Livingston and the Little Big- horn River near Wyola). These streams have a winter low, a runoff peak in May- July, and intermediate and closely similar flows in the summer (August to October) and spring (March-April) periods. The March-April, secondary spring flow peak and associated TSS concentrations observed in the Little Bighorn River near Hardin and in lower Rosebud Creek was not observed in the upper reach of the Tongue River. This may be because of the upper river's proximity to the Bighorn Mountains and because it has no extensive prairie drainage sys- tem. Except during the runoff period, the inverse relationship between flow and TDS-SC was not obvious in the upper Tongue, even though the high-flow:low- flow ratio of S.04 and the high-flow TDS:low-flow TDS ratio of 0.4S were similar to those obtained in the more mountainous segments of the Yellowstone River. The direct relationship between flow and TSS-turbidity, however, was noticeable. In general, TDS concentrations in the upper Tongue were high when compared to those obtained in the upper Yellowstone (tables 2S-28), and the Boulder and Stillwater rivers (Karp et al. l976a). Of the larger streams in eastern Mon- tana, TDS concentrations in the upper Tongue River were generally higher than those in the upper Little Bighorn River (table 42), slightly lower than those in the Bighorn River near St. Xavier (table 46), and generally similar to those in upper Rosebud Creek (tables 79 and 80). All of these stream reaches, and the upper Tongue, are close to each other and to mountainous regions; thus, TDS levels in the upper Tongue were not particularly high on a regional basis. Total dissolved solids concentrations were significantly lower in samples from the Tongue River than in samples from the small prairie streams such as Armells and Sarpy creeks (tables 64-69). The upper reaches of the Tongue River have been classified as B-D2 by the State of Montana; B-D 2 segments should have a marginal or transition zone, cold- water salmonid fishery (Montana DHES, undated). The high maximum summer temp- eratures of the upper Tongue indicate that this segment is definitely not B-Dl in character. Dissolved oxygen concentrations, including the minimum levels obtained during warm-weather periods and median pH values, were within the state's criteria for a B-D2 stream. Similar median pH values were obtained during all seasons, but meaian TDS levels demonstrated the characteristic cold- weather/warm-weather variations observed in Rosebud Creek and in other streams of the Yellowstone Basin. Neither the DO nor the BODs concentrations suggested severe organic pollution. This observation was reinforced by the low TOC con- centrations with a median TOC in the upper,reach (9. 1 mg/l) close to the na- tional average for unpolluted surface waters (Lee and Hoodley 1967). Thus, pH, DO, and BODs concentrations do not indicate water quality problems in the upper Tongue River. The outstanding issue is whether temperature is a water quality problem, and, if so, whether the upper Tongue has been appropriately classified a B-D2 segment, or whether a B-D3 designation would be more reason- able. Fecal coliform concentrations were occasionally high in the upper Tongue, particularly during the runoff period, and sometimes violated state standards. 189 TABLE 88. Summary of the physical parameters measured on various sites on the Tongue River near Decker (above the Tongue River Reservoir). August-October tlovember-February Harch-Apri 1 May-July r1 Min M.lx lied N Hin f-lax Med N r~i n Max Med N Min Max Med Flow 41 74.2 694 324 47 93.4 1000 230 29 153 2550 328 47 35.2 3390 1160 Temp 25 5.0 24.5 12.5 27 0.0 4.0 0.0 15 0.0 12.5 4.5 23 5.5 26.0 16.0 ( 17. 0?) pH 43 7.7 8.5 8.2 45 7.0 8.5 8.1 28 7.0 8. 5 8. 2 47 7.0 8.6 8.1 sc 43 531 1070 798 46 475 897 773 28 531 1061 838 47 230 1190 379 TDS 42 326 762 528 45 313 685 515 28 358 853 566 46 130 810 233 lurb 7 3.5 20 10 12 1 30 7 6 5 70 17.5 5 28 100 40 TSS 4 6.6 16 11 1 ----10.0 3 6 31 14.0 5 II 121 85.5 DO 9 6.0 11.0 8.5 12 9.6 12.8 10.9 7 7.9 13.4 11.4 8 7. 1 11.2 9.6 BOD 4 0.5 4.0 1.3 0 ------3 2.1 3. 5 3.4 5 0.4 4.3 3.2 FC 8 0 -96 43 11 24 540 68 6 2 130 16 5 23 2400 1800 Ca 42 38 91 69 46 30 84 71 28 43 110 67 46 24 70 38 Mg 42 27 85 50 46 26 77 47 28 25 72 50 46 4.6 80 18 TH 42 248 490 376 46 220 420 370 28 212 510 379 46 100 477 163 Na 42 15 68 38 45 19 48 34 28 21 59 41 46 5.5 110 13 K 42 2.3 6.9 4.0 45 2.2. 7.6 3.5 26 1.6 11 3. 9 44 1.3 5.8 2.2 SAR 42 0.4 1.4 0.8 45 0.6 1.0 0.8 28 0.6 1.2 1.0 46 0.2 2.2 0.5 HC0 3 42 171 331 282 46 159 330 284 28 143 314 266 46 100 271 143 TA 6 205 263 244 8 205 271 256 4 225 259 244 5 82 123 92 504 42 100 370 210 46 120 270 200 28 125 330 240 46 8.5 478 67 Cl 42 1.5 13 4.0 46 1.0 17 5.0 28 1.0 8.1 5.0 46 0.0 8. 9 2.0 F 42 0.2 0.6 0.4 45 0.2 0.5 0.4 28 0.3 0.6 0.4 44 0.1 0. 5 0.2 N 44 0.0 0.16 0.05 so 0.0 1.1 0. 31 30 0.0 0.84 0.11 48 0.0 0.54 0.09 ( . 9?) p 10 0.0 0.12 0.03 15 0.01 0. 32 0.08 8 0.01 o. 38 0.08 10 0.0 0.39 0.06 r~OTE: Measurements expressed in mg/1. Of the samples analyzed for fecals, 17 percent had concentrations in excess of state criteria for grab samples, 23 percent exceeded 200 colonies per 100 ml, and the median concentration of fecals during the May-July period was even greater, and, therefore, in excess of the state's average standard. However, 93 percent of the annual coliform load was observed during the high-flow period, dictating that the fecals were derived primarily from non-human and natural sources. This observation, and the fact that only seven percent of the samples had fecal concentrations exceeding the permissible criteria for surface water public supply (2000 colonies per 100 ml), indicates that this variable was not a major problem in the upper reach. Fluoride, chloride, and potassium were miscellaneous components of the calcium bicarbonate water in the upper Tongue, suggesting limestone formations within the upper drainage. Sulfate concentrations were also high and nearly equal to the bicarbonate levels; sulfate and magnesium were the secondary ions. In contrast, sodium concentrations were low, producing low SAR values; as a result, the waters were non-saline but very hard. The high calcium and sul- fate concentrations indicate that gypsum formations are also present in the upper Tongue River drainage (Bighorn Mountains). Because suspended sediment concentrations in the upper Tongue were not particularly high, salinity and common ion concentrations were the major potential water quality problems. The median annual suspended sediment concentration was 30 mg/1, indicating a good fishery (European Inland Fisheries Advisory Commission lg65). Highest TSS-turbidity levels occurred at high flows, but the median value and the max- imum concentration were still not particularly high in comparison to those in other rivers in the basin, including the Yellowstone mainstem. Judging from the common constituents, the waters in the upper Tongue River can be considered generally suitable for agricultural supply and excellent for all stock animals (tables 10-14). The waters have a low sodium hazard for irri- gation and low SAR values at all times, but they had a low-to-high salinity hazard for this use depending upon flow and season as shown in table 89. TABLE 89. Salinity hazard for irrigation from the upper Tongue River depending upon flow and season. Aug-Oct Nov-Feb March-April May-June Percentage of samples having a particular salinity hazard: low medium high TDS > 500 mg/1 TDS < 500 mg/1 0.0 0.0 0.0 8.5 30.2 32.6 32. 1 83.0 69.8 67.4 67.9 8.5 64.3 60.0 78.6 10.9 35.7 40.0 21.4 89.1 Overall, the upper Tongue has a Class I water for irrigation due to the low boron (less than 0.5 mg/1), SAR, chloride, sulfate, and SC-TDS levels (tables 15 and 16). However, according to the EPA (1976), waters with TDS concentra- tions in excess of 500 mg/1 should be used cautiously on salinity-sensitive crop and forage plants (USEPA 1g72). As indicated in table 89, the upper river would have TDS levels exceeding 500 mg/1 for a large percentage of the early spring and late summer-early fall portions of the irrigation season and in 191 the winter; the waters would have a high salinity hazard for irrigation during these periods. The best irrigation water from the upper Tongue would occur during the runoff season, which has a medium salinity hazard; runoff ~1aters would be applicable to all crop and forage species for about 90 percent of the time during ~lay, June, and July. The upper Tongue should probably not be used as a surface water public supply if other more suitable sources of water are readily available. This is due primarily to the hard (~1ay-July)-to-very hard (remainder of the year) water and to its high dissolved solids concentrations. As indicated in table 89, about 66 percent of the samples collected from the upper Tongue between August and April had TOS levels greater than 500 mg/1, in excess of the permissible criteria for public supply and the standard for drinking water (table 9). The water would be much more acceptable for public supply and drinking water during the May-July period, as only 11 percent of the runoff samples had TDS concen- trations in excess of these criteria and standards. However, the stream's tur- bidities during the runoff season would degrade the segment as a municipal supply source because they would exceed 75 JTU and the permissible criteria for turbidity in 40 percent of the high-flow samples. In addition, sulfate would tend to detract from the value of the upper Tongue as a public supply-- 22 percent of the samples had sulfate concentrations in excess of recommended levels during the August-to-April period. Regardless of the general unsuita- bility of the upper Tongue for human use, sa 1 i nity in this stream reach ~1oul d have only mild effects, if any, upon the aquatic biota of the river. Only 7.5 percent of the samples had TDS levels in excess of 670 mg/1, and only 4.9 percent had a specific conductance in excess of 1000 ~mhos/em. The major por- tion of the samples from the upper river had TDS and SC levels between 400 and 670 mg/1 (65 percent) and between 600 and 1000 ~mhos/em, respectively. Low nitrogen and phosphorus concentrations were evident in the upper Tongue during the late summer-to-early fall period of peak biological activity (table 88); in turn, a peak in nitrogen levels was obtained during the dormant winter season. Except during the August-October period, median phosphorus concentrations were at levels high enough to suggest eutrophic conditions, al- though they did not exceed the EPA's (1974b) criteria for eutrophication. The stream was probably non-eutrophic due to the low median nitrogen concentrations during all seasons except the less critical and dormant winter season of low temperatures (near o.ooc). About 17 percent of the samples from the upper Tongue had nitrogen levels in excess of the reference criteria (0.35 mg N/1), and 72 percent of these violations occurred during the winter season. However, only 1.7 percent of the samples had nitrogen levels in excess of the EPA's criteria. In contrast, 56 percent of the samples had phosphorus levels in excess of the criteria, and 5 percent had concentrations greater than the EPA's more stringent reference levels. As a result, only 9.4 percent of the total samples from the upper Tongue had both phosphorus and nitrogen at levels sufficient to cause eutrophy; 25 percent of the winter samples would have this status and only 3.5 percent would have this characteristic during the warmer weather periods of the rest of the year. Less than 0.1 percent of the samples had both phosphorus and nitrogen in excess of the EPA's reference criteria. These relationships further indicate an absence of eutrophy in the upper Tongue River. Although high salinity levels restrict certain water uses, the non-eutrophic waters of the upper Tongue have fairly good quality. Trace element concentrations, 192 which are discussed in greater detail later in this section, do not generally detract from this quality. Of considerable itnerest, therefore, is the poten- tial effect of the Tongue River Reservoir on the upper Tongue's quality; below are five possible effects: 1) concentrations of dissolved constituents via a water residence in the reservoir, and, consequently, an evaporation; 2) a lessening of seasonal oscillations in TOS and chemical com- position; 3) an alteration of seasonal chemical compositions through a water retention time and mixing; 4) action as a nutrient and sediment trap or sink; and 5) changing the fecal coliform, B00 5 , 00, pH, and temperature characteristics of the stream. Some of these effects may be related to an alteration of the seasonal flow pat- terns of the stream through artificial regulation with a general reduction in stream discharge as a result of reservoir evaporation. These assessments can most readily be made by comparing water quality and flow data from the inflow to the reservoir (i.e., the reach above the reservoir near Decker, table BB) to that from the outflow (i.e., the reach of the Tongue below the reservoir near Birney, table go). However, these stations may not be comparable due to the different periods of collection; thus, the data from the river near Miles City should also be considered in this regard as a check. In terms of subsequent water quality changes below the reservoir, comparisons of data from the Birney segment to that from the downstream Ashland-Brandenburg reach (table 91) are most appropriate. An assessment of the overall changes in water quality in the Tongue River from the state line to its mouth can readily be made by com- paring data from the upper reach above the reservoir to that from the river near Miles City (table 92) because these sites had similar sampling periods. The most obvious effects of the Tongue River Reservoir on downstream quality were related to changes in the river's TSS and fecal coliform concen- trations; these particular alterations might be considered beneficial. Fecal coliform levels were noticeably lower in the river below the reservoir, pro- bably as a result of water residence time in the impoundment with a subsequent die-off of coliform organisms. The low concentrations of fecals were obvious in the Birney and the Ashland-to-Brandenburg segments of the riv~r. Although coliform levels tended to increase slightly below Brandenburg, the effect of the reservoir on this variable was apparent to the lower reach of the stream, as the Miles City segment also demonstrated low bacteriological concentrations. As a result, fecal coliforms pose only occasional problems for use as public supply in the lower segments of the Tongue--only 3.7 percent of the samples collected from the river below the dam had fecals in excess of state criteria. In addition to the decline in coliform levels, TSS concentrations were definitely lower in the river immediately below the impoundment than in the Decker reach. The reservoir, therefore, apparently acts as a sediment trap. The annual median TSS concentration declined from 30 mg/l above the reservoir 193 TABLE 90. Sumnary of the physical parameters measured on various sites on the Tongue River near Birney (below the Tongue River Reservoir). August-October Novcmb~r-Fcbrua ry March-Apri 1 May-July fl f~in ~lax Med II ~11 n r~ax Med II :~in Max fled N Min l-1ax lied Flow 12 143£ 650 225 12 21.2 302 155 3 217 500 283 8 432 3500 930 (23?) Temp 14 10.0 22.0 14.8 14 0.0 9.9 1.0 5 0.0 7.0 3.8 8 8.0 23.0 15.4 pll 11 8.0 8.6 8. 32 14 8.0 B. 5 8.22 5 7.8 8.4 8.4 8 7.7 8.4 8.3 sc 13 372 949 725 14 765 1310 913 5 368 2550 890 8 280 801 670 TDS 10 228 743 543 13 480 1220 717 4 226 694 559 8 176 650 418 Turb 8 1 13 6.6 10 1 7 2. 5 2 2 5 3.5 3 19 42 22 TSS 6 3 9 5.4 6 2.4 12.6 4.1 3 3 12.8 6.0 5 16.4 51l 24 DO 11 7.2 10.3 8.8 13 11.4 13.9 12.2 5 9.4 13.8 11.4 8 7.4 10.0 9.3 BOD 6 0.8 3.3 1.4 5 1.8 3.7 2.2 3 2.3 3.7 2.8 5 1.7 3.9 2.2 rc 6 0 300 10 6 0 9 1 2 0 1 1 0 ------ (d 10 36 77 67 13 64 83 74 4 35 73 70 8 30 67 54 fig 11 17 55 47 14 44 110 53 4 17 50 48 8 13 46 38 TH 10 160 404 365 13 340 660 410 4 160 380 373 8 130 352 240 ila 10 15 51 39 13 37 170 52 4 18 56 47 8 13 51 34 K 10 2.7 5.3 4.6 12 3.4 15 4.6 3 4.6 6.9 6.9 6 1.7 5.8 2.9 SAR 10 0. 5 1.1 0.9 13 0.6 2.9 1.0 4 0.6 1.3 1.0 8 0.5 1.2 0.9 tlC0 3 11 157 300 274 13 271 621 300 4 125 240 287 8 122 254 225 TA 11 129 246 225 13 222 509 246 4 103 240 235 8 100 209 184 504 10 71 260 225 13 190 500 255 4 77 270 235 8 47 235 165 Cl 10 2 5 3. 7 13 1.2 10 4 4 2.0 4 3.4 8 1.4 5 3.0 r 10 0.2 0. 4 0.3 12 0.2 1.1 0.3 4 0. 2 0.4 0.3 6 0.2 0.3 0.2 N 13 <.01 0. 3 0.02 18 0.0 0.7 0.02 7 0.02 0.8 0. 2 10 0.0 0.4 0.1 p 13 0.01 0.21 0.03 18 0.0 0.03 0.01 7 <.OJ 0.38 0.05 10 0.0 0.4 0.1 r:OTE: ~:easurements elfpressed in mg/1. --,-~-~- TABLE 91. Summary of the physical parameters measured on various sites on the Tongue River near Ashland-Brandenburg. August-October r~ovembe r-February f·larch-Apri 1 1-ldy-July tl Min ~lax Med II !·lin Max Med II f·lin Max l·lod tl Min Hax Mod Flow II 187 806 245 11 83 298 218 6 202 1340 278 11 423 4270 780 Ternp 11 5.5 22.5 14.9 13 0.0 9. 3 0.7 6 0.0 10.5 3.0 II 14.0 26.0 18.0 pH 11 7.4 8.6 8.4 13 7.7 8.4 8.2 6 7.3 8.4 8.15 11 7.6 8.6 8.2 sc 11 452 1060 916 13 850 1430 1065 6 420 1073 1007 10 315 870 628 lOS 8 356 802 632 14 528 1265 . 748 5 225 797 773 7 203 694 564 Turb 8 1 18 2.2 13 1 20 3 5 3 200 a 4 4a 150 73 TSS 6 I. a 13 3. I a 1.0 33 4.0 5 <I 19 11 7 19 216 74 DO 9 7.2 12.0 9.7 12 a.o 12.8 II. 7 7 9.4 13.0 12.7 11 6.8 12.9 B. 4 BOD 5 1.3 3.4 .1.8 6 1.5 3.4 2.1 5 0.7 4.6 3.5 a 1.0 4.6 2.8 FC 4 0 10 0 7 0 65 0 3 0 0 0 3 0 29 20 Ca 8 52 71 66 13 63 a a 75 5 27 76 67 7 25 71 63 l~g 8 za 62 51 13 44 81 55 5 17 71 53 7 25 71 47 TH 8 250 418 379 13 340 536 408 5 140 410 404 7 120 373 350 Na 8 19 69 57 13 49 165 69 5 21 a3 6a 7 17 56 48 K a 3.2 6. I 5. 1 12 4.3 9.1 5.5 2 6.1 8.3 7.2 3 2.1 6.9 2. 3 SAR a 0.5 1.5 1.3 13 1.1 3.1 1.4 5 o.a 1.9 1.5 7 0.5 1.3 0.9 HC0 3 a 193 312 288 13 27a 426 327 5 124 301 275 7 130 260 256 TA a 175 266 240 13 22a 356 26a 5 102 256 226 7 107 220 210 504 a 130 300 250 13 210 500 zao 5 80 320 290 7 42 260 240 Cl 8 2.0 5 4. I 13 3.0 7.2 5 5 2.0 5 3.5 7 0.8 4.0 3. 0 F 8 0.3 0.4 0. 3 13 0.3 0.5 0.3 3 0.2 0.4 0.3 4 0.1 0.3 0.3 II 10 0.0 0.1 0.01 13 0.0 0.12 0.02 6 0.0 0.1 0.04 II 0.01 0.23 0.07 p 10 0.0 O.OB 0.112 13 0.0 0.06 0.01 6 '.01 0.3 0.03 II <.01 0.26 0.09 NOTE: /·1ea5urernent~ e~prcsscd in IIUJ/l. TMJI.E 92. SutlllltH"Y of physical parameters measured ·ln the Tongue River n('c1r Miles City. Au1JuSt-October /lovember-Fehruu ry March-Apri 1 floy-Ju I y II ~~ j II Nax fled II !~in Max Hed N Min 1·1ax f1ed II Min /1rlX Med flow -17 33 1070 235 52 70 1370 237 31 1~4 3370 430 48 52 1]~10 ell 1 C!tnp 23 6. I 24.4 17.0 27 0.0 9.4 0.0 16 0.0 20.3 4.3 25 II. 0 28.0 10.0 pll 46 7. 5 8.6 8.0 54 7.0 8.8 8.1 31 7.2 8.7 8.2 49 7.5 8.6 7. 9 sc 46 530 1170 811 54 377 1530 1020 31 441 1170 930 49 362 1100 628 105 44 362 817 518 50 24 3 1242 686 30 282 857 631 47 215 748 411 Turb 7 2 130 19 10 I 20 7 4 12 500 206 8 23 1200 130 rss 5 5. I 75.2 24 3 2 2 11.8 8.2 4 9 594 40 9 22 Rl4 264 00 9 8.2 11.6 9.7 9 10.6 13.2 12.9 6 9.0 13.3 10.9 12 6.5 9.8 8.4 800 ; 0. 7 3.0 1.8 2 1.4 2.6 2.0 4 2. I 3.5 3.0 9 0.6 6.2 2.2 rc 6 0 10,700 II 6 0 290 6 5 0 59 8 6 20 2800 37 Co 27 44 76 57 33 58 95 77 18 31 7R 67 26 27 72 49 fig 27 25 56 3R 33 39 72 57 18 17 62 49 26 14 51 29 Til 46 186 441 313 53 124 520 410 30 ISO 450 370 48 ISO 394 243 llo 46 32 110 60 53 26 130 74 30 29 100 70 40 17 110 47 t: 27 3.0 9.9 4.9 33 4.0 8. 7 5.5 16 4.5 8.2 6.0 23 1.9 7.8 3. 7 sr,R 46 0.9 2.5 1.5 53 1.0 3.0 1.6 30 1.0 2.4 1.6 4R 0.6 2.5 1.2 !IC0 3 46 204 365 262 53 136 448 334 30 139 343 286 48 137 316 226 TA 8 174 255 237 10 215 356 236 5 125 260 220 8 113 218 156 5114 46 120 360 210 53 78 4 75 21!2 30 an 360 262 48 68 360 158 Cl 27 1.7 6 3.4 34 3.4 12 5. I 18 2 8.9 4.4 26 0.6 5. 7 2. 9 F 27 0.2 O.R 0.3 33 0.2 0.6 0.3 17 0. 2 0.6 0.3 24 0.2 0.6 0.3 II 26 0.0 0.22 0.05 32 0.0 0.3 0.06 19 0.0 0. 35 0.06 26 0.0 0.21 0.06 (. 97?) p 14 .. OOR . 18 .02 18 0.0 . 15 .015 9 0.0 .82 .01 15 0.0 . 31 .027 (1.0') ---~-~----- to about 10 mg/1 in the Birney reach, with an annual median TSS concentration of 23 mg/1 in the downstream Ashland-to-Brandenburg segment. TSS levels also tended to increa~e downstream below the reservoir, and this increase was most obvious at high flows and in the Miles City reach of the river, which had an annua 1 medi a·n concentration of 82 mg/l . Thus, regardless of the reservoir's influence, the Tongue fishery's quality would lessen in a downstream direction, judging from TSS levels. The fishery should be good above the impoundment, excellent below the dam to Brandenburg due to the trapping effect of the reser- voir, and fair near Miles City as a result of the marked downstream sediment accumulation below Brandenburg. This accrual of sediment and consequent tur- bidity was apparently at high enough levels in the Miles City segment to also degrade the value of the stream as a surface water public supply for a large portion of the year (> 7S JTU). The Tongue River Reservoir also apparently acts as nutrient sink with generally lower concentrations of nitrogen and phosphorus obtained in the lower reach of the river from the dam to Miles City. This downstream reduction in nutrient concentrations was greatest during the winter, and resulted in an elimination of the November-February nitrogen peak in the lower river; the only exception to these reductions occurred during the runoff period in the segment of the river immediately below the dam near Birney. The entire lower segment of the river was definitely non-eutrophic during all seasons and much less eu- trophic than upstream above the reservoir; this was most noticeable in the reach of the river near its mouth near Miles City. The lower river, like the reach near Decker, was probably nitrogen-limited, but low phosphorus concentrations would be much more critical in curtailing stream production in the Miles City reach than in any of the remaining segments of the stream. Based on the cri- tical nutrient data (table 92), the low primary production potential of the Miles City reach of the river could reduce the harvest of the Tongue fishery. In the lower river, only 0.7 percent of the samples would have both nitrogen and phosphorus concentrations in excess of their reference criteria, contrasting to a 9.4-percent value for samples from the Decker segment. The reservoir apparently had little or no effect on the pH, temperature, dissolved oxygen, and BODs characteristics of the stream; none of these para- meters violated state criteria for a B-D 2 or B-D3 stream (table 8) or indicated pollution problems in the lower segments of the Tongue River. BOD 5 values might have declined below the reservoir, and all reaches demonstrated a March-April high in this variable with an obvious low during the August-October season; the BODs concentrations did not indicate organic pollution in any instance. This was also reflected in the stream's generally high DO concentrations and in the absence of definite, consistent downstream DO changes in the river. The inverse relationship between DO and warm-weather/cold-weather tempera- tures was again evident in the Tongue. The river had slightly warmer winter temperatures immediately below the dam than in the Decker reach, but with cooler grab sample temperatures in the spring and lower warm-weather maximums in the Birney segment. This trend ~1as reversed in the river below the reservoir towards Miles City, where winter temperatures again approached 0.0°C and a general down- stream increase in median and maximum values were evident below Birney through the remainder of the year. Grab sample temperatures appeared to be higher in Miles City than in the Decker reach, which corresponds to the classification change of the Tongue River from a B-D 2 to a warm-water, B-D3 stream towards its 197 mouth. The high maximum temperatures near Miles City also indicate a B-D3 stretch of water. The general tendency for the Tongue to have warmer down- stream temperatures can also be seen in the once-daily temperature data from the USGS (USDI 1955-1974b) for the June-September period (1970-1974) as seen in table g3. TABLE 93. Percentage of temperature readings in the Tongue River during the June-September period, 1970-1974, greater or less than a particular temperature. Temperature Range Tongue River near Decker Tongue River at Miles City <19.40C 66.6 53.2 >lg.40C 33.4 45.8 >20.0°C 32.6 42.0 >22.0°C 8.9 10.3 SOURCE: USDI 1955-1974b. The Tongue River Reservoir apparently has a definite effect in reducing down-reservoir flow volumes in the Tongue River; this is evident both in the USGS (1974) average discharge data for various sites on the river and in the flow data of tables 88 and 90-92. The USGS has obtained a yearly mean flow at the state line near Decker (above the impoundment) of 495 cfs (14 years of record) with an 8.5 percent decrease in average discharge at the dam (to 454 cfs with 35 years of record) (USDI 1974). Evaporation from the reservoir pro- bably accounts for at least a portion of this loss in water volume. An addi- tional 5.4 percent decrease in average annual flow is evident in the Tongue at Miles City (to 427 cfs with 31 years of record) (USDI 1974). This added downstream loss in water volume may be due, in part, to subsequent diversions for irrigation because of minor tributary inputs below the dam. Yearly dis- charges as cubic-feet-per-second, calculated from the data in tables 88 and 90-92 by weighting the median flows on the basis of months-per-seasonal-period, were similar to the annual mean flows obtained by the USGS as follows (in- cluding the percentage of difference between the two determinations): Tongue River above the reservoir near Decker--503 cfs (+ 1.4 percent); Tongue River below the dam near Birney--388 cfs (-14.5 percent); Tongue River near Ashland-Brandenburg--375 cfs; and Tongue River near Miles City--413 cfs (-3.3 percent). The greatest discrepancy between the two sets of annual flow estimates was ob- tained on the Birney reach (and the Ashland-to-Brandenburg segment), on which the tabulated data would not be as readily comparable to the USGS information as the other locations due to the shorter period of collection and smaller sam- ple size. As a result, inter-reach flow comparisons are most valid when made between the Decker and Miles City and between· the Birney and Ashland-Brandenburg data. 198 I ~ The Birney:Ashland-Brandenburg comparison (tables 90 and 91) indicates a downstream decline in flow below the reservoir while the Decker:Miles City comparison (tables 88 and 92)) shows the overall decline in yearly flow through the Montana reach of the Tongue (about 17:9 percent). The Decker:Miles City comparison suggests definite alterations in the seasonal flow patterns of the river from above the reservoir to the stream's mouth; these alterations can be seen in the percentage change in flow by season from the Decker to the Miles City reach as follows: August-October, -27.5 percent; November-February, +3.0 percent; March-April, +31.1 percent; and May-July, -30.1 percent. Flows remained relatively constant from the upper to the lower reach of the river during the winter months, indicating that reservoir inflow equalled outflow. In contrast, the lower reach had significantly higher flows than the upper segment in March and April, suggesting an artificial regulation wherein the reservoir was drawn down in anticipation of the runoff season (outflow greater than inflow); however, an early spring runoff from the lowlands below the reservoir could also have contributed to the secondary March-April flow peak--particularly noticeable at Miles City (table 92). The lower reach below the impoundment had significantly lower flows than the upper segment during the runoff season; this might have been related to reservoir regulation through a storage of good quality runoff water in which the inflow was greater than the outflow. Downstream flows were also significantly lower during the August- October period, which might have been due at least partially to irrigation di- versions below the reservoir during this period of the year. Such reductions in river flow below the reservoir--8.5 percent near Birney and 13.9 percent to Miles City (USDI 1974)--would imply a concentration of the dissolved constituents in the upper Tongue of about 9.2 percent to the lower stream near Birney and about 16.2 percent near Miles City. Annual median TDS levels were found to be about 25.4 percent higher in the reach immediately below the reservoir than near Decker and 19.7 percent greater at Miles City as follows: Decker reach, 456 mg/1; Birney reach, 572 mg/1; Ashland-Brandenburg segment, 677 mg/1; and the Miles City reach, 566 mg/1. The annual TDS load of the river near Decker was similar to that at Miles City--619 tons per day and 631 tons per day, respectively, and the 1.9 percent downstream increase in loads might have been a reflection of tributary inputs to the lower river. Tributary inputs may also account for the greater increase in TDS at Miles City than was predicted on the basis of water volume loss. As a result, the Decker: Miles City comparison (tables 88 and 92) suggests an overall downstream increase in TDS in the Tongue River. · The Decker:Birney comparison indicates that a part of this downstream in- crease in TDS was due to the concentrating effects of the reservoir, and the Birney:Ashland-Brandenburg comparison points to a subsequent increase in TDS below the reservoir to Miles City. However, this latter feature was not totally consistent in the data from Birney to Miles City; i.e, data from the Ashland-to- Brandenburg reach appeared to be anomalous. This apparent anomaly was most likely due to the incomparability of data from the Birney:Ashland-to-Brandenburg reaches to that from the Miles City segment because of their different collec- tion periods (table 3). Water quality runs conducted by the state WQB along various stations on the lower river at similar dates also indicated a down- stream increase in TDS (about 23 percent) between Birney and Miles City; this can be shown by the station (USDI 1968) means of TDS and SC across the six 199 collection sites listed in table 94. TABLE 94. Downstream increases in TDS in the Tongue River between Birney and Miles City. Tongue River Station· TDS (mg/1) sc (\lmhos/cm) TDS/SC Pyramid Butte above Birney 711 9D9 D.7B Birney Village 761 953 D.8D Ashland 762 951 D.8D Brandenburg 818 1D60 0. 77 Carland 851 1 D81 0.79 Miles City 876 1D98 0.80 The Decker:Birney water quality data are not readily comparable because of different collection periods; this may account for the wide discrepancy be- tween the predicted percentage increase (9.2 percent) in TDS on the basis of water volume lost and the observed increase (25.4 percent) from above to below the reservoir. Therefore, the Tongue River's downstream increase in TDS from Decker to ~1iles City cannot be quantitatively separated from the effect of the downstream effects below the reservoir on the basis of the data in tables 88 and 90-92. Data from the limnological investigations of the Tongue River Res- ervoir may more accurately describe the impoundment's influence in concentrating downstream dissolved solids because the reservoir's inflow and outflow are regularly sampled in these studies. The influences of the impoundment on lessening seasonal fluctuations in TDS concentrations and chemical composition and its effect in altering seasonal and downstream chemical compositions are much more obvious from the data in tables 88 and 9D-92. The lessening of seasonal TDS oscillations are shown by the ratios of low-flow seasonal TDS concentrations of the four Tongue segments to their runoff TDS levels in table 95. TABLE 95. Ratios of low-flow seasonal TDS concentrations to runoff TDS levels in the four Tongue segments. Ashland-to- Brandenburg Decker Reach Birney Reach Reach Miles City Reach Aug-Oct 2.27 1.30 1.46 1.26 Nov-Feb 2.21 1. 72 1. 70 1.67 March-Apri 1 2.43 1. 34 1. 60 1. 54 May-June 1.00 1.00 1.00 1.00 These ratios were significantly lower below the reservoir, indicating the develop- ment of reduced differences between runoff and low-flow TDS concentrations below the impoundment; this suggests a mixing of seasonal waters as they are stored in the reservoir. The high TDS season occurred during the March-to-April period in the upper segment of the Tongue, but high TDS levels developed during the winter 200 season below the dam. early fall than during the Tongue; this would TDS concentrations were lower during the the runoff period in the Birney-to-Miles be advantageous for irrigation purposes. late summer- City reach of Downstream increases in TDS from Decker to Miles City varied considerably between the four monthly periods. The total downstream percentage increases in TDS by season were: August to October, -1.9 percent; November to February, 33.2 percent; March to April, 11.5 percent; and May to July, 76.4 percent. Such seasonal differences were probably the results of reservoir mixing. For example, the good quality of runoff water coming into the reservoir would be altered somewhat by combining with the previously stored lower quality of low- flow water; this mixed water would then be released, partially accounting for the 76.4 percent increase in TDS downstream below the dam during the May-July period. However, a part of the seasonal increases in TDS may also have been due to tributary inputs to the river below the reservoir. The downstream in- crease in TDS was lowest during the August-October period, contributing to the development of a fairly good water quality in the lower river during a critical phase of the irrigation season. The effect of the reservoir in lessening the Tongue's downstream seasonal fluctuations in chemi~al composition and initiating a general downstream chem- istry change is shown in table 96. In the upper Tongue, the (Ca + Mg):Na and HC03:S04 ratios were high during the runoff season when influences from the mountainous headwater areas having calcium bicarbonate waters would be at their greatest. The ratios were lowest during the March-April period in correlation with the early runoff from lowland areas having a sodium sulfate water. The two ratios from the late summer through winter were intermediate to these sea- sonal extremes. This pattern has been observed in the Little Bighorn and Yellowstone rivers. In the lower river, however, such obvious seasonal dif- ferences in ratios and chemical compositions were largely ameliorated with the calcium-magnesium-sodium and bicarbonate-sulfate relationships which were similar through all seasons and not descriptive of any obvious seasonal patterns (except the low HC03:S0 4 ratio during the spring near Miles City). These de- velopments were also probably related to the reservoir mixing of seasonal waters before release. A general tendency for the river to become more sodium sulfate in character towards its mouth is also indicated by these ratios, particularly those based on annual median concentrations. The more sodium-sulfate water in· downstream reaches near the mainstem is also characteristic of many streams in the Yellowstone Basin. The downstream increase in total dissolved solids indicates a general down- stream degradation of water quality in the Tongue River. As a result, the waters in the lower segments of the river would_restr.ict use more than would waters upstream-from-the reservoir. · Ca 1 ci um. and magnesium concentrations did not increase to any great extent in the Tongue River towards its mouth, and the downstream increases in TDS and SC were primarily related to the 2.0-fold increase in annual median sodium concentrations from Decker to Miles City with 1.2-and 1.3-fold increases in sulfate and bicarbonate, respectively. However, the river was generally calcium bicarbonate in nature throughout its length in Montana, although the stream tended to· have a calcium-sodium bicarbonate water near its mouth. Calcium exceeded magnesium in all segments during .all seasons; magnesium, sodium, and sulfate were secondary ionic constituents, and fluoride, chloride, and potassium were insignificant constituents. The waters were very 201 N C) N TABLE 96. Seasonal (Ca + Mg):Na and HC0 3 :so 4 ratios in the Tongue River. Ashland-Brandenburg Decker reach Birney reach reach (Ca + Mg):Na HC0 3 :so 4 (Ca + Mg) :Na HC0 3 :so 4 (Ca + Mg) :Na HC0 3 :so 4 Aug-Oct 3.13 1. 34 2.92 1.22 2.05 1. 15 Nov-Feb 3.47 1.42 2.46 1.18 1.88 1.17 Mar-Apr 2.85 1.10 2. 51 1.22 1. 76 0.95 May-June 4.31 2.13 2.70 1. 36 2.29 1.07 Annual Median 3.32 1. 39 2.65 1.23 1.97 1.10 Miles City reach (Ca+Mg):Na HC0 3 :so 4 1.58 1.24 1. 81 1.18 1.65 1.09 1.65 1.43 1. 70 1.22 hard during all seasons in the lower segments, and they were generally non- saline with the exception of a few slightly saline winter samples. Waters in the lower Tongue River below the dam (tables 90-92) have a low sodium hazard (SAR values less than 3.1), but a high salinity hazard for irri- gation during the low-flow periods of the year, and a medium salinity hazard during the runoff season (USDA 1954). Like the upper segment, the lower Tongue also has largely a Class I water for irrigation due to the low boron (less than 0.5 mg/l), SAR, chloride, sulfate, SC, and TDS levels (tables 15 and 16). How- ever, this water is less suitable for the irrigation of salinity-sensitive crop and forage plants than the water in the Decker reach because a higher propor- tion of the lower Tongue samples had TDS concentrations in excess of 500 mg/l (USEPA 1976). The major .exception waul d be the August-October peri.od. The greater potential effects of salinity on using the lower Tongue waters for irri- gation against using that upstream above the reservoir is shown in table 97. TABLE 97. Salinity hazard for irrigation in the upper and lower Tongue River. Percentage of samples having a particular salinity hazard: upper Tongue near Decker lower Tongue below the dam medium high TDS > 500 mg/l medi urn high TDS > 500 mg/l Aug-Oct 30.2 69.8 64.3 35.7 64.3 58. l Nov-Feb 32.6 67.4 60.0 3.7 96.3 93.5 March-April 32. l 67.9 78.6 21.4 78.5 76.9 May-June 83.0 8.5 10.9 59.7 40.3 38.7 The best water quality for irrigation occurred during the runoff season in all segments of the Tongue River, although there was a definite downstream degradation during this period with a greater proportion of the samples from the lower reach below the dam having a high salinity hazard. The runoff waters from the lower segments would probably be applicable to salinity-sensitive spe- cies about 61 percent of the time, as opposed to 90 percent of the time from the upper reach above the Tongue River Reservoir. This May-July degra- dation in downstream quality might have been related to reservoir concentrating effects and seasonal mixing, to the mode of reservoir operation, or to down- stream tributary inputs with a poor water quality. A lesser quality or irri- gation water was available from the Tongue during the late summer and early fall than during the runoff period, when there was a high salinity hazard in most of these warm-weather samples; these waters would be applicable to salinity- sensitive plants for only about 36 percent to 42 percent of the time during this season. The quality remained unchanged or improved downstream from August to October, contrasting with the degradation observed during the runoff season. Absence of downstream change might have been due to reservoir operations causing the water quality to be artificially maintained for irrigation. That is, if water quality during August-October had been allowed to change in a fashion similar to that .observed during the winter season, then the waters would have been much less fit for irrigation than was observed. The Tongue River during the March-April period also demonstrated a slight downstream de- gradation in quality and an increase in salinity; these waters would be generally unfit for the irrigation of salinity-sensitive species during about 77 percent to 7g percent of this early spring season. The lower segments below the dam would also be generally unsuitable as a surface water public supply due to the water's extremely hard nature, high total dissolved solids concentrations, and high sulfate levels; the lower Tongue would be less suitable for this use than the upper reach due to the downstream in- creases in TDS and sulfate. In the lower segments of the river, 78 percent of the samples collected between August and April had TDS levels in excess of the permissible criteria and standards for public supply and drinking water; this was true of 66 percent of the samples above the reservoir. The waters of the lower Tongue would be ~ore acceptable for public supply during the runoff period when the TDS levels are diluted, but it would still have a much lower value than the upper reach--about 40 percent of the lower reach May-July samples had TDS levels greater than 500 mg/1, and only 11 percent of the upstream segment sam- ples. The high suspended sediment concentrations of the runoff season would tend to detract from the better water quality for municipal supply at this time, particularly near Miles City where 63 percent of the May-July samples had turbidities in excess of 75 JTU (compared to 40 percent of the samples collected above the reservoir); 14 percent of the samples collected between August and April near Miles City had turbidities in excess of this reference criteria. Turbidity would be much less critical above Miles City to the dam, as only 6 percent of the yearly samples would have turbidities greater than 75 JTU as a result of the trapping effect of the reservoir. Twice as many samples collected below the dam over the Decker reach had sulfate concentrations in excess of the recommendations for public supply (45 percent as opposed to 22 percent). The downstream salinity increase in the Tongue River could also produce somewhat greater effects on the stream's biota in the lower segments than up- stream. About 31 percent and 23 percent of the samples from the river below the Tongue River dam had TDS concentrations and SC levels greater than 670 mg/1 and 1000 ~mhos/em, respectively; in contrast, only 7.5 percent and 4.9 percent of the samples from the upstream reach had TDS and SC in excess of these refer- ence levels. However, the overall effects of salinity on aquatic life would be expected to be mild throughout the river from Decker to Miles City because most of the samples collected from the lower segments had TDS concentrations between 400 mg/1 and 670 mg/1 (50.8 percent) and less than 400 mg/1 (18.3 percent). SC levels were usually between 600 ~mhos/em and 1000 ~mhos/em (59.6 percent) and less than 600 ~mhos/em (17.3 percent). The entire length of the Tongue River in Montana should be an excellent source of water for all stock animals because TDS and ionic constituent concentrations in samples from the stream were well below the threshold and limiting levels prescribed for these parameters (tables 10-14). Data for miscellaneous constituents and numerous trace elements, .in both TR and dissolved forms, are also available on the Tongue River from the USGS and the state WQB. These data were not seasonally classified and were compiled according to river reach as summarized in table 98 for the Birney and Decker segments and in table 99 for the Ashland-Brandenburg and Miles City segments. As indicated in these tables, ammonia concentrations were low and were not at levels high enough to significantly increase the eutrophic potential during most seasons. Ammonia was not at adequate pH levels to suggest toxicity to 204 TABLl 98 Surm~.~ry of miscellaneoi.IS constituent and trace elerrent concent!'ations measured in the longue River aOOve Ashland, Montana. Various ~ites n!!ar Declel' above Ule r!.!Scrvoi r 111scellaneous constituents and a total recoverable IX!tals " Min ''" "'' oo' rec~ 1 strep NH 3-Ij a 0.02 o. 14 0.06 Sl IOC .., A1 •• B ,, ,, co '" ,, '" ,, "' ll l~rl "' Ill " ,, ,, v '" " 3.4 " a. 1 • '·a 16 9.1 l .13 2.a .50 7 0 0 <.01 .ouz l < .1 .12 .11 I .. .. <.01 ' 0.0 ",OJ < 001 I .. < 01 • 0.0 0.01 < 01 ' ~ .01 0.01 < 01 " . 05 '. 8 .17 • 0.0 <.00\ ".001 ' .02 ·" .06 6 0.0 (. 10 <.05 • 0.0 < .CXll 0.0 2 .39 .57 .~B l <:.10 .;.10 (. 10 10 ~.OJ 0.03 0.01 NOTE: MeaSLm~nts are c•preHed in rrrg{l. '\1: 01. N•1. bB!!.CO.andLi: Ol.N•l. 'cd: u.o, rl•1; Co: ·:.007. N~l. dDO c~JlrcsscCI as perccntaqP. of satur·atlon. Dis~olved metals " Min "" 7 0 0 .OJ 2 0.0 0.0 137 0.0 .38 2 0.0 ~.01 2 0.0 0.001 2 0.0 0. 01 7 . 002 .011 '6 0.0 o.' ' 0.0 .0002 2 0.0 .02 2 .01 .Ol 2 0.0 0.001 2 .002 .002 7 .001 .009 ' 0.0 .002 2 .001 .001 7 0.0 .OJ 205 Various sites below the rc~ervoir and above Ashland Hiscellanf!ou~ canst i tuents an db totd 1 recove rab I e Dissolved meta he IIINdlS ""' " Min ''" ""' " "'" ... 23 81 107 93 1 .. . . 10 13 .-.ol o. 1) 0.03 " 1.1 7. 7 5.3 (21?) ' 6 10 ' l 0.0 < .001 .01 ' <. 10 O.S4 0.29 5 .01 ·" 0.0 a < 001 (.Q\ 0.002 5 0.0 .002 .O'l 11 <. 10 0.18 0.10 l .10 ·" (, B?) l 0.0 .07 -=.01 5 0 0 .01 -=.001 16 (. 001 0.01 <.001 <.01 • < .01 0.01 < . 01 1 .. .. .00~ " 0.0 0.02 < . 01 6 .ooz .004 .12 " .04 '-' .IS " 0.0 .09 0.0 " 0.0 < .001 < .0002 • 0.0 0.0001 .01 l .02 .Ol .02 " ( .01 O.IZ 0.04 23 0.0 .12 ( .001 l 0.0 .002 .002 5 0.0 .006 .004 " < .01 <. 10 < .05 6 0.0 .006 .001 10 0.0 0.001 <.001 6 0.0 .001 6 .55 ·" .63 l • S2 .IJ .001 11 ( .05 <.II < 10 5 .001 .009 .01 23 ~.01 0.06 < 01 6 .002 .02 I .28?) Hed 0.0 .02 0.0 .11 0.0 0.0 .002 ·. .004 .OJ ( .26?) .-.0001 .02 .01 .002 .002 001 .001 .52 .002 .01 ( 1. 9?) TA.BlE 99. SI.SII\.Jry of mhce\lo~neou~ constituent and tr'.Jte eleJ~en~ tcnctntr<Jti~;~n~ ~a~ured In tl'le Tongue River below A~nl~nd. ~ontand. Various sites near Ashldnd-Brandenburq Mlscelldnf'ou~ cnrtHit•IPntl ant\ tDtd I recoverab 1 o! Oi..,soh-ed !'letah~ ~Uis " I": in "" ''" " "'" !1u Co lor oo' 22 61 106 96 Feco~ I streP I ----0 NH)·N 12 < .01 0.\8 0.06 " roc ,, AI " 8 8• •• Cd Co ,, '" ,, "' u Hn Mo ,, Pb s. 5' v '" IB I.B 10 6.5 5 8 17 10 6 <. 10 0.90 0. )0 (6.0?) " < .001 <.at 0.002 II <. 10 0. 49 0. II 26 o.o 0.01 < .001 7 0.0 0.05 0.01 28 0.0 0.03 < .01 26 ... ).2 .21 (. 13?) 14 0.0 <.001 ~ .0002 12 ( .01 0.20 0.02 20 < .01 0.10 .05 9 0.0 .001 0.1 9 .65 1.0 .77 10 <.05 <.II <. 10 10 <.OJ 0.05 < .01 llOU: Measurements are expreso;ed In mg/1. 11Co: <.01. rt•2; Se: 0.0, ll•l. bBe: <.01, r~~2. 2 0.0 ~ .001 2 0.0 .030 2 0.0 0.001 " .02 .17 2 .076 .OIJO 1 .01 .01 1 0.0 0.001 2 0.0 ~ .01 ' .001 .005 15 o.o ·" 2 <.0001 0.0001 2 .OJ .OJ 2 0.0 .02 ' 0.0 < .002 1 .002 .008 ' .001 .002 2 .69 ·" 2 ( .003 < .003 ' 0.0 .08 CA9: <.001. :.1: 0.02, Be: 0.0\, !1a: 0.0, Ni: 0.00\; o~ll N•l. dOO e•pressed as percental]!! of uturation. "'' < .001 .015 ~ .001 . 10 .083 .01 <. 001 < .01 .003 ·"' -- .OJ .01 < .002 .005 .002 .82 < .003 .04 206 lledr ~!i les City ~heel \ano~ous constltu~nts ~ndb lDtJI I'~COVC!rdble t:'<!ta Is Diuohed sr.et.Jls ' "'" '"' ''" ' !',In "" TO ' 20 6 2l " 110 9) 12 16 3<00 " II -:.01 o. 14 0.04 92 2. 6 12 7.0 7 6. 8 27 16 3 .31 3.' .60 9 < .001 0.026 0.002 6 0.0 .001 ll < .10 0.24 0.10 39 .025 .210 I ---- 21 0.0 o. 02 <. 001 6 0.0 .00\ 7 ~ .01 0.10 < .05 6 o.o < .01 9 0.0 0.08 <.01 6 0.0 .01 2l < .01 0. 17 < .01 6 .001 .007 21 .OJ 7• .68 " 0.0 . 255 " 0.0 0.0035 < .0002 6 0.0 .0002 11 < .01 0.01 --I ---- " .01 .68 .05 18 o.u .02 18 0.0 <.10 <.0) 6 .001 .005 10 0.0 .003 .001 6 0.0 .001 8 .08 1.3 .75 I ---- II '.05 0. 17 <. 10 I ---- 2l ~.a 1 0. l4 0.01 6 .01 .02 ' "'' 0.0 .110 .09 0.0 0.0 0.0 .003 .OJ 0.0 03 .01 .00) 0.0 .86 .001 .01 the river's biota, even at maximum concentrations. The lower river below the dam was close to DO saturation in all segments, and the percentage of DO saturation tended to increase downstream in opposition to a general increase in TOC levels. Median TOC concentrations were near the national average for unpolluted streams (Lee and Hoadley 1967) between Decker and Brandenburg, and TOC was only slightly above the national average concen- tration near Miles City. Fecal strep concentrations did not indicate municipal- organic pollution, and the annual median fecal coliform:fecal strep ratio near Miles City (0. 17) indicated that the fecal counts obtained from the Tongue River were probably derived from animal rather than human sources (Millipore Corporation 1972). Silica concentrations in the Tongue were also generally below the national average for surface waters (Davis 1964), and silica levels tended to drop immediately below the dam from up-reservoir concentrations, pos- sibly as a result of phytoplankton utilization in the impoundment and an ulti- mate deposition to the sediments via the diatom frustules. Silica concentra- tions then tended to increase from Birney to Miles City. None of these constituents suggested water quality problems. The high TDS levels of the stream, and the high TSS concentrations in some reaches and seasons, are the main detractions from the river's water quality. Most of the trace elements in the Tongue River were in low concentrations and did not suggest major water quality problems. Of the total recoverable and dissolved concentrations, this includes Ag, As, Ba, Be, Cd, Co, Cr, Li, Mo, Ni, Pb, Se, and V. TR concentrations of Al, Fe, and Mn were occasionally high in the river samples, but this was probably related to suspended sediment levels, since the maximum-median TR levels of these parameters declined below the dam near Birney in correspondence with the decrease in TSS. The TR levels of Al, Fe, and Mn then demonstrated a subsequent downstream increase below the reser- voir in correlation with the downstream increase in TSS; this was particularly noticeable near Miles City in relation to the high TSS concentrations of this stream segment. However, the dissolved concentrations of these three consti- tuents were low and usually below their reference criteria. Only 2 percent and 4 percent of the samples from the Tongue had dissolved concentrations of Fe and Mn, respectively, in excess of these criteria. High TR concentrations of B, Cu, Sr, and Zn were also occasionally obtained in the Tongue samples, but the dis- solved levels of B, Cu, and Zn were consistently below their reference levels, and Sr was not at adequate levels to pose water quality problems. Of the metals, therefore, only mercury appeared to have TR and dissolved concentrations high enough to detract from the stream's quality by sporadically exceeding the grab sample criteria for public supply and aquatic life (tables 9 and 19}. Median dissolved concentrations of mercury were consistently below these reference levels, but 26.3 percent of the samples from the Tongue had ·detectable levels of this constituent, and 10.5 percent of the samples had concentrations as large as 2 ~g/1. Miscellaneous Tributaries Most drainage basins, like the Tongue River system, are characterized by having a few major tributaries and numerous minor tributaries to the mainstem. ·Generally, water quality data are not available for the minor streams due to their small flow volumes or their intermittent-ephemeral natures. However, 207 some data have been collected for such streams in the Tongue River drainage as a result of the strippable coal deposits in the region and the related necessity of preparing environmental impact statements. The USGS has recently initiated a sampling program that includes many of these small streams (table 3), and the state WQB has collected some samples from several of these tributaries (table 6). Nevertheless, such data are not abun- dant due to the short periods of collection, and, since many of these small streams are intermittent or ephemeral, this would preclude sampling for several months of the year when the creeks happened to be dry, further reducing sample size. The data, therefore, were insufficient for a seasonal classification, and water quality information was combined geographically in order to expand the data base, as shown in table 100. Trace element data were further combined on this basis as shown in table 101. The major tributaries--Hanging Woman, Otter, and Pumpkin creeks--are considered in other sections of this report. The various small and minor streams of the Tongue River drainage do not appear to be affected by large pollution inputs. Values of pH were neither distinctively high nor noticeably low, and they were within the state criteria for B-D streams. Dissolved oxygen levels were high and also within state stan- dards, and median DO concentrations were usually within 10-11 percent of satur- ation. These features, plus the low BOD 5 levels, suggest a general absence of organic inputs; however, median TOC concentrations were above the national average, particularly in the lower streams of the drainage below Birney. Fecal coliform concentrations were low and did not suggest municipal pollution. These features, plus the fact that the TSS-turbidity levels of these small streams were not particularly high in comparison to those obtained from the Tongue River and other streams in the Yellowstone Basin, indicate that the high TDS and ionic constituent concentrations are the major features detracting from the water qual- ity of these small tributaries. However, the importance of TDS varied consid- erably among the 15 creeks. In some instances, TDS and ionic constituent concentrations were remarkably low and did not preclude any·water uses. This is seen in the minimum values for the data sets and by some of the median concentrations. In these cases, collec- tions were probably made during a runoff period from a recent rain or snowmelt, explaining the high maximum flows. Diluted TDS concentrations would be expected from these samples. The ephemeral streams of the region would probably produce this type of water quality data. The more southern tributaries of this nature above Birney were generally calcium-magnesium bicarbonate, and sodium and sul- fate were the secondary ionic constituents. However, the more northern tribu- taries were sodium sulfate, which corresponds to the downstream chemical change in the Tongue River to a more sodium sulfate composition. SAR values were low in these two classes of streams. Some samples were collected which had high TDS and ionic constituent con- centrations. This is demonstrated by the maximum values of each data set and by the median data for Deer and Cook creeks. Streams having this type of water quality are probably the intermittent and perennial minor streams of the region, sampled during low-flow periods, with small but generally sustained flows (explaining the low minimum flows). Although low water volumes would probably preclude many of the water uses from these streams, they would probably have a poor class of water for irrigation during most of the year (Class II or 20B N 0 <D TABLE 100. Summary of the physical parameters measured in small streams in the Tongue River drainage. Creeks above Birney (Bull, Canyon, Fourmile, Deer Creek near Decker Stroud, Squirrel, Young) Cook Creek near Birney II ~1i n Max Ned II Min ~lax l·led II Min Max Mcd Flow 8 0.1 9 0.42 11 <l 14 2 13 0.4 43 1 Temp 8 0.0 20.2 10.8 11 0.0 19.0 0.5 13 0.0 19.0 2.0 pll 8 7.4 8.4 B. 2 12 7. 5 8.46 8.2 13 7. 7 8.6 8.1 sc 8 450 6250 5350 11 170 2617 1240 13 270 2250 IH40 TOS 8 268 5299 4070 10 102 2179 835 12 152 1470 1325 Turb 7 2 400 12 8 1 4B 35 12 1 2400 3 TSS 1 ----29 5 4.7 124 85 1 -- -- 2 DO 8 8.6 13. I 10.9 II 8.0 12.4 11.2 13 6.8 13.B 12.0 (18.1) BOD 1 ----4.4 4 1.7 4.5 2.2 0 ---- -- FC 0 -- -- --3 0 76 13 0 -- -- -- Ca 8 32 320 275 10 13 100 65 12 19 97 82 Mg B 14 340 240 10 6.7 126 B7 12 II 130 115 Til 8 140 2200 1650 10 60 732 54B 12 93 780 670 1/a 8 30 B75 685 10 6.5 372 45 12 16 200 190 K 7 7. 9 17 10 7 7. 1 15 9.9 12 4.7 15 13 SAR B 1.1 8.6 6.9 10 0.3 6.0 1.1 12 0. 7 3.5 3.1 HC0 3 8 86 638 563 10 71 603 402 12 92 670 639 TA 8 71 52:1 469 10 58 525 332 12 75 550 525 504 8 130 3250 2550 10 26 966 275 12 46 670 550 Cl 8 4 27 14 10 2 8.6 4.8 12 2 9 6 F 7 0.1 0.5 0. 3 7 0.1 0.7 0.3 12 0. I 1.2 1.1 N 8 0.0 0.6 0.05 26 0.0 O.B 0.1 . 12 0.01 1.7 0.55 p 8 <.01 0. 34 0.04 26 0.0 0.46 0.06 12 0.0 0.21 0.03 (1.5') NOTE: f-1easurements e,.;.pressed in mg/1. Creeks below Birney (Bear, Beaver, Cow, Foster, Liscom, Logging, Threemi 1 e) II ~lin f~ax Med 21 0.05 300 7 21 0.0 19.5 2.0 21 7.0 8.6 7.9 21 120 4200 583 21 84 3100 441 21 2 200 30 3 2.0 32 0.0 21 6.3 12.4 10.6 2 1.3 1.8 1.6 2 0 >200 -- 21 15 170 31 21 3.9 220 27 21 59 lJOO 190 21 3. 7 780 43 19 5.0 20 9.0 21 0.2 lJ.O 1.5 21 60 747 137 21 49 613 112 21 15 1800 160 21 1.0 16 4 20 0.0 1.1 1.3 21 0.0 0.2 0.03 21 <.01 0.54 0.16 lABLE 101. S:;•1dry of rnio;c.e11.!neou'> ccr.stiluent dnd ~r~c.e e1~n~ c.o~c.entr<t~ions ~reHt:ret:: tn ~-=-..J11 strear::s In the Tonqu!! Rive..-!lr.}inat;('. DJ' ,, IOC AI ,, 0 o. "' " Co ,, '" ,, Hg ll "" "" r;t " So S< v '" t~C!' CrcPl dnd other cr'"e~~ Mi~ce11dn ... ous const 1 tuf!rlts and !'If~) rf"rnvrrJblr wet.ll s " M1r1 "" ''"'11 " 78 "' 90 14 '·I 19 7.2 I .. .. I• ' .06 ·" .11 II 0.0 -.01 .DDZ I .. .. 15 6 <.001 o.oz 0.001 7 0.0 .06 .01 II 0.0 .07 .01 12 .06 5.0 .96 12 0.0 < .001 .0002 12 .01 .61 . 16 7 <.O!i 0.20 0.10 7 0.0 0.0 0.0 I .. .. .55 I .. .. '-.1 9 < .01 0.05 0.01 tmT£; Mf'aSur('~fltS <Ire t'•Prt'SSed In ~/1. <1A9: 001. II• I. bAIJ: .002, /1•2. 'oo expressed~~ pe.-cr:nto~.qe of sature~tion. " 1 ' 14 I 3 1 I ' ' " I r 1 l ' ' I l ' abO•"t• Blr~et Dlno1ved ~'l.'t~1sd ~Hn fl,h ned .03 .06 .c.::. .004 .01>' .004 .07 .19 .ll .. .. .07 0 0 ~. 003 0. 0 0 0 .DOl .. .. .. ~ .006 0.0 ~ .006 ~ .005 .005 .009 .007 .01 .29 .10 .. .. .0001 .. . . .06 .oz .12 .07 .. .. c .003 < 006 < OOb <.006 (.002) <.006 <.00(, ... 006 ( .004) .. . . .87 .. .. ·:.OOJ .01 .06 .035 210 Coot Creek e~nd o~her crPei.s tx.>1o., Bl rney l-ll~c': 11 dneous constltue'll~ .-1nd tol•l rrcov•r•blr- '"ctalsb mctJls Dissolved " Min ~~~. ~~~d " Mlc Ma• Yod 31 63 117 89 ll 1. 7 " 8.8 1 " 4) 39 5 .10 II .17 J 0.0 .01 .01 18 0.0 .005 .002 ' .001 .004 .003 l2 .07 -" .16 ' .043 . 060 .052 J 0.0 .01 < .00~ 18 < .001 0.03 0.01 J 0.0 < OJ 0.0 ' < .009 < Oil < Oil 16 0.0 .01 .01 J 0.0 <.013 < 010 17 ~ .01 0.05 . 0.01 J .002 .oos .DOl " .OS 10 1.1 l2 0.0 .23 .OS 17 0.0 < .001 0.0 ' 0.0 ~ .0001 <.0001 ( .0002) ' .10 .II . 105 17 ~ .01 0.11 o.oa J .01 . OS -" ' < .OOJ ~ .004 < .oo: J < 006 ... 008 < 008 ( .002) 16 <. 10 ~ .10 <. 10 J < .009 <-.013 < Oil ( .006) 16 0.0 .003 .001 ' I ·' I .6 1.6 ' .liD~ OOB ( .008 7 0.0 .07 .01 J 0.0 .01 .01 Class III) and be poor sources of water for municipal supply (with high TDS, sulfate, and hardness levels) and stock (with high TDS, magnesium, and sulfate levels in excess of the threshold and limiting criteria for many stock animals, particularly in Deer Creek). These streams, with their low flows, would also provide a poor environment for freshwater biota since TDS and SC levels usually exceeded 1350 mg/1 and 2000 umhos/cm. These streams had either a sodium sulfate (as in Deer Creek) or a sodium bicarbonate water (as in Cook Creek), with magnesium, calcium, and sulfate or bicarbonate the secondary ionic constituents; SAR values were high. Fluoride, chloride, and potassium were insignificant constituents of all of these miscellaneous waters, and nitrogen and phosphorus were not in concentra- tions high enough to suggest eutrophy, except in a few isolated samples. Trace element levels did not indicate water quality problems (table 101). Of these constituents, only manganese had dissolved concentrations in excess of the ref- erence criteria (in 40 percent of the samples). Hanging Woman Creek Hanging Woman and Otter creeks, two of the major tributaries of the Tongue River, join the river in the southern portion of its drainage in Montana (USDI 1968). Hanging Woman Creek is the more southern of the two streams, flowing in a northerly direction from Wyoming and joining the mainstem near Birney. Although the volumes of flow in these two creeks are not particularly high, they appear to be perennial, as no days of zero flow were recorded by the USGS in 1g74 (USDI 1974). Flows in Hanging Woman Creek were somewhat less than those in Otter Creek during this year. These streams had an average annual flow between 5 cfs and 8 cfs in 1974, and daily flows ranged from about 0.2 cfs in the late summer to values approaching 150 cfs during the chinook per- iods of the winter season (in January and February) (USDI 1974). Such early runoff events are characteristic of lowland prairie streams. The added average discharge of the two creeks represents about 3 percent of the mean annual flow of the Tongue River; thus, these major tributaries could exert an influence on Tongue River quality, particularly if they happen to have the high TDS concentrations that are also typical of a prairie stream. Some water quality data have been collected from these two streams by the state WQB, and the USGS has recently initiated a monthly water quality sampling program on the creeks in conjunction with their flow gaging stations. As a result of these efforts, data for the major parameters were adequate for a seasonal clas- sification as summarized in table 102 for Hanging Woman Creek. The water quality in Hanging Woman Creek is characteristic of what might be expected from a lowland, eastern stream in the Yellowstone Basin; this is evident in its high TDS concentrations and SC levels and in its sodium sulfate composition. These features correlate with the downstream increases in TDS-SC in the Tongue River below the reservoir and to the river's chemical change towards a more sodium sulfate water in a downstream direction to Miles City. TDS concentrations in Hanging Woman Creek were between 2.43 times greater in the winter and 6.14 times greater during the runoff period than those in the Tongue River below the dam near Birney; data from these two locations are directly comparable due to their similar periods of collection (table 3). Specific 211 N -N TABLE 102. Sun111ary of the physical parameters measored ln Hanging Woman Creek near Birney. ' Auyust-October flovembe r-February March-Apri 1 II ~lin Max fled N Nin Max Med N Min Mux flow 7 0.4E 3.2E 2 11 1 65 3 7 2.E 125 Temp 7 8.0 20.5 16.0 11 0.0 6.5 0.0 7 0. 5 9.0 pH 6 8.1 8.50 8.22 11 7.7 8. 3 8.1 7 7.4 8.50 sc 7 2300 3210 2700 11 630 2680 2500 7 240 3963 TDS 6 1620 2526 2055 11 "404 2283 1740 6 176 3668 Turb 2 6 12 9 4 6 42 11 4 4 187 TSS 2 2.5 13.8 8.2 4 9.0 30 17.7 4 11.0 67.5 DO 5 5.8 9.6 8.6 10 8.4 12.D 11.4 7 11.2 13.2 BOD 1 ----0. 5 4 1.6 7.8 4.0 4 3.2 6.D FC 3 5 1D10 10 4 0 70 5 3 D 260 Ca 6 87 114 liD 11 31 120 100 6 27 235 fig 6 110 155 130 11 21 130 120 6 11 160 Til 5 700 858 810 11 160 794 770 6 110 1270 Na 6 300 440 360 11 63 370 300 6 17 620 K 5 15 18 16 9 11 19 14 3 7.0 15 SAR 6 4.9 6.5 5.4 11 2. 1 5.7 4.8 6 0. 7 7.5 HC0 3 6 426 631 604 11 112 669 619 6 89 604 TA 6 431 518 496 11 92 549 507 6 73 513 504 6 760 1333 1070 11 210 1030 820 6 57 2080 C1 6 0.0 14 12 11 3.5 14 11 6 1.8 12 F 6 0.2 1.1 1.0 9 0.1 1.1 1.0 4 0.1 0. 9 II 6 0.0 0.2 0.02 11 0.02 0.43 0.22 7 0.0 0.3 p 5 <.01 0.11 0.02 11 0.0 0.32 0.02 7 < .01 0.56 flOTE: Medsurcments e:.:pressed in mg/1. ---~-- May-July Mcd N Min t·lax Med 2.9 5 0.4 10 7 3.8 5 10.0 22.0 15.0 7. 95 5 8.0 8.40 8.20 2600 5 2814 4736 3310 2059 5 211D 4196 2565 23 1 ----24 19.5 2 33.0 70 51.5 11.8 5 5.8 11.8 10.0 4.1 2 2.9 3.5 3.2 72 2 2 92 52 97 5 110 196 125 124 5 130 230 160 796 5 835 1438 1000 341 5 370 725 430 8.0 3 14 16 15 5.2 5 5.5 8.3 5.9 518 5 505 668 585 424 5 414 548 480 1035 5 1115 2464 1400 6.5 5 11 14 12 0.7 3 0.7 0.9 0.8 <.01 5 0.0 0.1 0.0 0.02 5 <.01 0. 78 0.04 -- conductance levels in Hanging Woman Creek were between 2.74. times higher in the winter and 4.94 times higher during the runoff season than those in the Tongue near their confluence. The waters in the smaller stream were extremely hard, but they were slightly saline, and TDS concentrations in Hanging Woman Creek were at levels high enough to affect most water uses. The TSS-turbidity levels of the tributary were low and did not indicate major water quality problems; annual median values of 16 JTU and 40 mg/1 would indicate a good-to-moderate fishery (European Inland Fisheries Advisory Commi- ttee 196S), given no other limiting factors. Such low TSS-turbidity levels in this tributary correspond to the general absence of distinct downstream in- creases in these variables in the Tongue River between the dam and Brandenburg. However, the high maximum turbidity value in March-April indicates occasional large slugs of sediment in this tributary. Highest TSS levels in Hanging Woman Creek were obtained during the May-July, high-flow period of the stream, cor- relating with the season of maximum downstream increase in TSS in the Tongue mainstem. Although the median BODs levels in Hanging Woman Creek during the winter and the spring were somewhat higher than the BODs levels typical of most streams in the Yellowstone drainage, they were not at levels high enough to suggest organic pollution--only 36 percent and 9 percent of the samples~had BODs con- centrations in excess of 4 mg/1 and 7 mg/1, respectively. High BODs levels occasionally exceeding 4 mg/1 and approaching 10 mg/1 can be expected to occur even under natural conditions. The high DO concentrations and low fecal coli- form levels indicate an absence of pollution inputs to the creek. The concen- trations of these variables were generally within the state criteria for a B-D3 stream during all seasons, as were the pH values, and the fecal counts were well below the permissible level for a surface water supply (USDI 1968). In addition, Hanging Woman Creek does not appear to be in a eutrophic condition at present. Although a few samples were obtained from the creek with high phosphorus con- centrations in excess -of the EPA's (1974b) reference criteria (0.3S mg P/1), 93 percent of the samples had phosphorus concentrations less than this level, and the median concentrations of this critical nutrient were less than O.OS mg P/1 during all seasons. Because nitrogen concentrations were extremely low, except for a winter peak observed in other streams, only 1 percent of the sam- ples from Hanging Woman Creek would be expected to have both nitrogen and phos- phorus in excess of their reference levels. These features, and the water's low suspended sediment concentrations, indicate that salinity is the major water quality problem of the stream. Sodium and sulfate are the dominant cation and anion in water samples'from the creek (table 102). As a result, SAR values were high, indicating a medium sodium hazard for irrigation at the specific conductance levels of the stream. Magnesium concentrations exceeded those of calcium; together, these constituents were the secondary cations. Bicarbonate was the secondary anion, and chloride, fluoride, and potassium were the minor chemical components of the samples. Fluoride concentrations were somewhat higher in Hanging Woman Creek than in most other streams of the Yellowstone Basin, with the exception of those in the upper reach of the Yellowstone mainstem near Yellowstone National Park above livingston tables 2S and 26). Fluoride levels were also very close to the optimum range for drinking water in Hanging Woman Creek and were generally within the control limits (table 9). 213 Hanging Woman Creek would provide a very poor class of water for public supply due to its extremely high total dissolved solids, sulfate, and hardness levels. Median sulfate concentrations of the stream exceeded the threshold levels for stock during the winter months and 1~ere greater than the 1 imiting levels during the remaining seasons; median bicarbonate concentrations also were in violation of the limiting criteria for stock animals during the entire year (California WQCB 1963). These characteristics would definitely reduce the value of the stream as an agricultural supply even though median TDS concen- trations (less than 2500 mg/1) were not at levels high enough to degrade the creek for this use; only 7 percent of the samples from Hanging Woman Creek had TDS concentrations in excess of 3000 mg/1. This creek would also be a poor source of water for irrigation, as it had a medium sodium hazard and a very high salinity hazard for this use (USDA 1954). The waters in the creek would be designated as a borderline, Class II water for this purpose (tables 15 and 16) due to the high SAR, sulfate, specific con- ductance, and total dissolved solids levels. As noted by the EPA (1976), waters with TDS concentrations greater than 2000 mg/1 " ... can be used for tolerant plants on permeable soils with careful management practices." These waters, therefore, should probably not be applied to the salinity-sensitive and semi- tolerant species listed in table 17, particularly during the May-July period. Similarly, the high salinity levels of Hanging Woman Creek would be expected to affect the aquatic biota, as 82 percent to 86 percent of the samples had TDS- SC levels greater than 1350 mg/1 and 2000 ~mhos/em. Salinities in excess of these levels might be judged to have detrimental influences on the freshwater biota. Hanging Woman Creek, like many prairie streams in eastern Montana, might be considered to have a poor class of water, principally on the basis of its high TDS levels. Hanging Woman Creek has been designated a 8-D 3 stream by the State of Montana, butits waters, as noted above, would definitely not be suitable for "drinking, culinary· and food processing purposes" (Montana DHES, undated) without the application of extensive treatment for the removal of total dis- solved solids. In addition, the suitability of its waters for the "growth and propagation of non-salmonid fishes and associated aquatic life" and for agri- cultural supply might be questioned. Thus, although most of the water quality parameters in samples from the creek, such as pH, DO, temperature, and fecal coliforms, were in accord with its B-D3 designation, salinity would certainly make inappropriate certain of the water-use descriptions associated with a B-D 3 classification, given no accessory treatment. This is true of many streams in eastern Montana. As a result, in order to more accurately describe such streams, some supplementary designation should be applied where water uses are restricted by high salinities but not by pollution inputs or other factors. Miscellaneous constituent and trace element data are available for Hanging Woman Creek as summarized in table 103. Median silica and TOC concentrations were somewhat greater than the national average or median for surface waters, but these constituents did not suggest pollution problems. The low TOC values were in accord with the low BOD5 concentrations of the creek and also indicate the absence of organic inputs to the stream. All of the tributaries to the Tongue River, including Otter Creek, had median DO concentrations between 88 percent and 91 percent (tables 101 and 103) of saturation; such consistencies in percentage of saturation among these creeks suggests the natural level of 214 I IAE!L[ 103. Sunm.Jry of m1scello~neou~ CDrl\tltuer~t and trace ele:TEnt concentroJtions r.ea<>ured In Hanging r.'ort~~~n and Ottt'r Cl"'l'e•s. Ho~nging 'olc.~o!n Creek nro1r Birney Otter Creek at Ashlo~nd Ml see llaneous M"iscellcmeous con!. t ttuent '> .tnd ccr1H lluents o~n::lb total n!COverable to::al reco~erat>1e Dis<>olved =>eta he metals Dissolved l:l:'tdl<>11 llletd Is " "'" ''" ... , " "'" ... ... , " ~hn !'Ia. ""' , Min "'" "'' oo' " 72 1 .. .. II " 110 91 I.:Hl-N 2 o.oz o.os 0.015 l 0.0 0.06 O.UJ ;; " 6.7 " 16 II 2. I II 7.3 IOC 2 II 14 12 ; 2 ll 16 \4.5 " l 0.9 6.4 2.0 l 0.0 .0< .02 l .16 .78 .23 4 0.0 .so .25 ,, 15 0.0 ~ .01 .002 2 0.0 0.001 <. 001 IS 0.0 < .01 .001 2 .001 .001 .001 ( .006) B 4 ·" ·" .23 18 .12 .82 .28 4 .36 . 53 .<0 " ·" ·" .45 •• J .0)\ .<l'O .040 ) .Ol .OJ .01 Be ) 0.0 < 01 .005 • ~ .001 0.01 ~ .01 Cd 19 < .001 0.02 ~ .01 ) 0.0 .035 < OJI " ~ .001 0.01 < .01 4 0.0 · .OS .001 ( .001) ,, 10 0.0 .014 <.01 ) < .01 0:. oz ( .02 g 0.0 .09 0.0 4 0.0 .·.OJ ... 01 ( .006) ,, 19 <.OJ o. 02 ( .01 ) < .00) 0.004 <. 00) 19 0.0 .II .01 4 . 001 .01 . 005 ,, 19 .22 ). ' .66 " 0.0 I . ; ·" 20 .15 1. g .49 II .01 . ,, ·" Hg 16 0.0 < .001 ~ .oooz 1 0. 0 < .0001 ( .0001 15 0.0 ~ .001 ·: .0002 2 0.0 <. .0001 < .0001 ( .0004) (.OOOS) ll J .09 .10 . 10 I .. .. • IS 4 .ll ·" .IJ "" " .04 . )9 .II ) .01 .OJ .01 " .01 .36 .08 4 .01 .04 .04 Mo ) < 000 0. 005 < 005 I .. .. .007 4 <. .006 .01 ( .01 ( .004) Nl J • .. ooa 0.01 .008 4 .010 < 0\4 < 010 " 12 <. 01 0.10 ... 10 l <.01 <. .oz ' 01 ll , .. 01 0.10 •.. 10 • ' 010 .0\4 < .010 ,, 8 0.0 .002 .001 I .. .. .001 8 0.0 .003 .001 I .. .. .001 ,, ) I . ; 2 ) 1.6 J I . ) I .4 1.3 ) I B 1 ) 2 0 ) I .I I .8 I .I v 4 .. 10 .10 < .10 J .005 ' 01 ( .005 4 ' ID ' 10 10 4 <.01 < 01 ' 01 '" 14 ( .01 o.oz 0.01 ) 0.0 .01 .01 " ' 01 0.04 0.01 4 0.0 0. 11 .005 rfOTE: Hed<>urelfll;!nl'> o~re I!•PI"'l'\~ed in mq/1. 11 G<11: 01. N·l~ Bi, f.(', Sn, It. lr: ~.oz. N•L Ag: •.002. II•J: Co: <.OZ. 1/;J. DSt>; 0.0\, N•l: 111: 0.05, II• I. eGo!. 11: 01, 71•1; 1l1, Ce. Sn, lr: <.OZ. N·l~ Ag: <.DOZ. /1=3: Co: <.OH, /1=3. dOO t'>Prr~·.e::l H oercenl.tij(' of \.tlt.~r.tt ion. 215 DO saturation that characterizes these streams. Like the TOC levels, ammonia concentrations were also low, and they were not at levels high enough to in- crease the stream's eutrophic potential or to be toxic to aquatic life. This latter feature also applies to most of the trace elements with small TR or dissolved concentrations. Of these constituents, only iron had its maximum dissolved concentration in excess of the reference criteria for drinking water (USDHEW 1962), public supply (USDI 1968), and aquatic life (table 19); this was not the case, however, for its median dissolved concentrations, and only 17 percent of the samples from Hanging Woman Creek had dissolved iron in excess of 0.3 mg/1. As a result, the trace elements did not significantly detract from the quality of water in this stream. Otter Creek Otter Creek, another of the major Tongue River tributaries, flows in a northerly direction before joining the Tongue near Ashland (USDI 1968). How- ever, Otter Creek has all of its drainage in Montana. Data for the major para- meters are summarized in table 104 for Otter Creek, and data for the trace elements and miscellaneous constituents are presented in table 103. The TR concentrations of trace elements of most Otter Creek samples did not indicate great water quality problems. This would include, most notably, ammonia, As, Be, Cd, Hg, Li, Mo, Ni, Se, and V; the dissolved concentrations of these 10 constituents were also low or undetectable, as were the dissolved levels of 9 other trace elements which had no TR information--Ag, Ba, Bi, Co, Ga, Ge, Ti, Sn, and Zr. However, some of the trace elements had high median or maximum TR levels. Silica, Al, 8, Fe, Mn, and Sr were noticeable in this regard, but also Cr, Cu, Pb, and Zn. Such high TR levels were probably asso- ciated with suspended sediment because the dissolved concentrations of most of these constituents were low and below their reference criteria; this would in- clude B, Cr, Cu, Mn, and Pb. Silica and Sr concentrations did not indicate water quality problems. Of the various trace elements, only Al and Fe had dissolved concentrations in excess of certain reference criteria. The median and maxi- mum idssolved levels of Al were greater than the recommendation of the EPA (1973) in relation to aquatic life. In terms of iron, 18 percent of the sam- ples from Otter Creek had dissolved concentrations in excess of the criteria for drinking water (USDHEW 1962), surface water public supply (USEPA 1973, USDI 1968), and aquatic life (USEPA 1973),· although the median dissolved level of this constituent was less than these values. In addition, one of the sam- ples from Otter Creek analyzed for zinc demonstrated a dissolved concentration in excess of its reference criteria for the aquatic biota (USEPA lg73). For the most part, however, the trace elements do not appear to be at levels high j enough to consistently detract from most of the water uses from Otter Creek. 1 As suggested by the trace element data (table 103), the water quality in 1 Hanging Woman and Otter creeks was found to be similar, which might be expected considering the proximity of their drainage areas (USDI lg68). Both of these creeks had poor inverse relationships between median seasonal flows and TDS-SC levels. In Hanging Woman Creek (table 102), the highest median TDS-SC levels were obtained during the May-July period of greatest flow. In Otter Creek (table 104), median TDS concentrations were closely equivalent through all seasons regardless of median flows. For example, a maximum difference in 216 N ..... __, TABlE 104. Su~ry of the physical par~meters measured in Otter Creek at Ashland. August-October November-February il f~in Mox I· led II ~1i n 1·1ax Med II Flow 7 0.1 4 1 11 I. 5E 131 4 6 Temp 7 5.0 24.0 11 0 11 0.0 7.5 0.0 6 pll 6 8.1 8.62 8.6 12 7.7 8.5 8.1 6 sc 7 1616 3080 2950 11 410 3900 "3125 6 TOS 6 2080 1676 2255 11 240 2861 2390 5 Turb 1 1 9.0 5.5 5 7 14 8 4 TSS 1 13.0 23 18 5 I 35 18.0 4 00 6 7.4 11.7 3.4 11 10 6 12.4 11.9 6 BOO 1 . . .. 3.3 3 2.2 3.3 2.1 4 FC 3 0 200 a 4 0 18 7 4 (a 6 57 77 66 11 23 169 99 5 >19 6 ISO 190 162 11 15 182 170 5 Til 6 780 930 843 11 120 1116 960 5 lid 6 313 460 395 II 30 460 420 5 K 6 8.1 24 22 9 8.5 27 20 2 SAR 6 5.6 6.8 6.0 II 1.2 6.5 5.7 5 HC0 3 6 542 670 628 10 110 750 663 5 TA 6 438 550 531 11 90 664 539 5 so. 6 1100 1300 1162 ll 100 1500 1190 5 Cl 6 0.0 16 l 3 II 3 16 12 5 F 6 0.7 1.0 0.3 10 0. l 0.8 O.R 4 N 6 0.01 0. 13 0. l 11 0. 10 1.6 0.40 6 p c -:.01 0.11 0.04 II 0.0 0.17 O.Ol r, fi(JI[: /~ed'.un~~~~~~rll', I~J.prt:~.~.cd in UUJ/l. ~1arch-Apri I May-July ~1i n f~ax Med ll f·1in Max Med 6.0E 160 11.7 5 0.03 15 6 0.0 13.0 1.1 5 10.5 11.0 18.2 7.2 . 8.40 8.35 5 7.9 8.40 8.1 370 2961 2355 5 1810 3305 3070 128 1533 1204 5 2110 2786 1190 5 37 11 0 . . .. .. 4 79.5 16 1 . . .. 2.0 9.9 13.5 11.6 5 5.0 10.0 9.6 ( 18.0?) 2.5 3.7 3.0 2 3.9 3.9 3. 9 0 100 5 1 .. --4 23 92 H4 5 73 162 91 17 171 13A 5 160 193 180 l 30 934 795 5 840 1199 950 26 400 350 5 360 470 390 10 15 13 3 17 17 17 1.0 5. 7 5. l 5 4.9 6.6 5.4 . 120 590 52 A 5 SOl 628 593 98 497 449 5 411 519 4U6 80 1270 1070 5 1200 1530 1300 1.5 10 fLS 5 10 13 11 0.2 1.0 0.6 3 0.6 0. 7 0.7 0.0 0.3 0.1 5 0.0 0.1 0.04 ., .01 0.6fl 0 .Ill 5 <:.01 O.OR 0.04 - median TDS between seasons of only 8 percent was obtained in Otter Creek, with only a 2 percent difference in median TDS between the low-and high-flow periods (August-October to March-April); this contrasts with the 96-percent and 87- percent values obtained for the Yellowstone River near Miles City. Water samples from Otter Creek also had high TDS-SC levels, along with a sodium sulfate com- position that characterizes most of the lowland streams in eastern Montana. The waters in Otter Creek were extremely hard and were usually slightly to moderatley saline. TDS concentrations and SC levels were possibly somewhat higher in Otter than in Hanging Woman Creek during most seasons, with annual median TDS and SC values in the first stream (2300 mg/1 and 2937 ~mhos/em) about 1.11 and 1.06 times greater than the annual medians in Hanging Woman Creek: TDS concentrations in Otter Creek were between 3.33 times in the winter and 5.47 times during May-July greater than those in Tongue River near Birney. Although the tributary flows were comparatively low, the high TDS concentrations of these two creeks indicate a potential salinity loading to the Tongue mainstem via these sources, corresponding to the downstream increase of TDS in the Tongue below the dam. The possible effect of Hanging Woman and Otter creeks towards increasing TDS levels in the Tongue River below the dam can be shown in table 105. TABLE 105. Effects of Hanging Woman and Otter creeks towards increasing TDS levels in the Tongue River below the dam. Hanging Woman Tongue River from Tongue River from and Otter creeks Ashland to Brandenburga Ashland to Brandenburgb ch mg/~ mg/1 Increased mg/1 Increased Flow TDS T~ TDS Aug-Oct 3 2122 563 3.7% 6~ 16.4% Nov-Feb 7 2111 777 8.4% 748 4.3% March-April 15.6 2177 644 15.2% 773 38.3% May-July 13 2438 446 6.7% 564 34.9% Annual 38.6 2249 531 8.4% 640 30.6% ~Calculated. Observed. ~Flow weighted. Percentage increase in TDS over that in the Birney reach (table 90). As indicated by the above loading calculations, these two tributaries apparently have an influence on the salinity levels of the Tongue River, and they may be able to increase the median TDS concentrations of the mainstem about 3.7 percent to 15.2 percent, depending upon season. The annual increase in median TDS due to these two streams would be nearly 8.4 percent. However, the individual daily effects from these creeks could be greater or less than these values depending upon the specific flow-TDS relationships of the Tongue and its tributaries at that particular time. Except during the winter, mainstem TDS increases attri- butable to these two creeks were significantly less than the observed increases 21fl ~ i ' from the Birney reach to the Ashland-Brandenburg segment of the Tongue. TDS inputs from Otter and Hanging Woman creeks would account for only about 27 percent of the median yearly downstream increase in mainstem salinity below the reservoir. As a result, other features were also apparently contributing to this increase in salt concentrations in the Tongue River. Such·features could include, as examples, inputs of other saline tributaries below the dam (i.e., the minor tributaries, such as Cook Creek, summarized in table 100, and others), irrigation diversions and evaporation with the subsequent inputs of saltier return flows, accrual of lowland groundwater with high TDS concentra- tions, and saline seep (Montana DHES 1975). The chemical composition of water in Otter Creek was found to be quite similar to that in Hanging Woman Creek. In both cases, sodium and sulfate were the dominant ions, producing high SAR values and a medium sodium hazard for irrigation. Fluoride concentrations in Otter Creek were less than those in Hanging Woman Creek, but fluorides in the first stream were also higher than the values typical of most streams in the middle-lower Yellowstone Basin (gen- erally less than 0.7 mg/1). However, fluoride levels were not high enough to ~etract from water uses. Magnesium-calcium and bicarbonate were the secondary ionic constituents of Otter Creek, and fluoride, chloride, and potassium were insignificant components. In both streams, calcium concentrations were less than the magnesium levels; this feature was greatest in Otter Creek. Such low Ca:Mg ratios suggest dolomitic formations in the middle Tongue River Basin, in accord with the latitudinal-geographic similarity and orientation of the Otter Creek drainage in relation to other drainages east of the Bighorn River that also had high magnesium concentrations (e.g., Tullock, Sarpy, Armells, and lower Rosebud creeks). The Ca:Mg ratios generally declined downstream in the Tongue River in response to these tributary inputs as follows (based on the annual median Ca and Mg concentrations: Decker reach, 1.51; Birney reach, 1.42; Ash- land-to-Brandenburg, 1.31; and the Miles City reach, 1.43. Salinity and the high concentrations of particular ionic constituents ap- peared to be the major factors detracting from water quality in Otter Creek; none of the remaining parameters and trace elements (table 103) appeared to have concentrations· high enough to consistently alter the creek's quality. Sample pH levels from the stream did not suggest water pollution problems. The pH and DO levels of the stream and the fecal coliform concentrations were consistently in accord with Montana's requirements for a B-D3 water. With the high DO concentrations (the median value was within 9 percent of·saturation) and the low BOD 5 , TOC, and fecal levels, Otter Creek was apparently free from significant organic-municipal inputs. In addition, TSS-turbidity levels did not lower the water quality in the creek. The levels of these variables in the Otter Creek samples were generally less than those obtained from Hanging Woman Creek, and the. annual median TSS concentration, 14 mg/1; would suggest an excellent fishery in Otter Creek (Euro- pean Inland Fisheries Advisory Commission 1965), given no other limiting factors. Similarly, the low phosphorus and nitrogen concentrations indicate no eutrophy problems in Otter Creek. Median phosphorus concentrations were less than its reference level for eutrophy during all seasons; with the exception of a winter concentrational peak, this was also true of nitrogen. Only 7 percent of the samples collected from Otter Creek.would be expected to have both phosphorus and nitrogen in excess of their reference levels, and the bulk of these samples would be collected during the less critical winter period. As a result, Otter Creek, like most streams in the Yellowstone Basin, does not appear to be eutro- phic at present. 219 Although measurements of many of the major parameters indicate excellent water quality (table 103), the water in Otter Creek is unfit for most, if not all, beneficial uses due to salinity. Water-use limitations and associated rationale would be the same as those for Hanging Woman Creek. This would nec- essitate eliminating the stream as a suitable source of water for public supply due to its high TOS, sulfate, and hardness levels. Its very high salinity haz- ard makes it unsuitable for irrigation (it is a Class II to borderline Class III water for this use), along with its high sulfate concentrations, in excess of limiting levels for stock animals. Also, Otter Creek would provide a poor en- vironment for the freshwater aquatic biota, as 93 percent of the Otter samples had TDS concentrations in excess of 1350 mg/1 and 90 percent of the samples had SC levels in excess of 2000 ~mhos/em. The waters in Otter Creek therefore has a poor quality for most beneficial applications. Pumpkin Creek Pumpkin Creek is the third major tributary to the Tongue River. It is the most northern of these streams and has a rather extensive drainage area located entirely within Montana. It also flows in a northerly direction before joining the mainstem about 15 miles south of Miles City. Water quality and grab sample flow data for Pumpkin Creek are summarized in tables 106 and 107. Pumpkin Creek can be characterized by its wide fluctuations in flow, ranging from zero on numerous occasions to daily flows approaching 900 cfs, and instanta- neous flows as high as 1660 cfs (USDI 1966-1974b). Zero discharges and low flow values were usually observed from summer to early winter, and the maximum discharges were usually observed during the late winter and spring. However, extremely high flows also occurred during other periods of the year (USOI 1966- 1974b). High flows were most consistently obtained between February and mid- July. Pumpkin Creek is an intermittent stream which measured zero flow on 25 per- percent of the days monitored by the USGS. Although Pumpkin Creek is inter- mittent, its average annual flows were the same or greater than those in Hanging Woman and Otter creeks. Discharge in Pumpkin Creek averaged 14.3 cfs in water year 1973 and 4.5 cfs in water year 1974; this compares to average flows during these years of 5.2 cfs to 7.8 cfs in the other major tributaries (USDI 1966- 1974a). The similarity in mean flows between intermittent and perennial streams of the Tongue River drainage was due to the weighting effect of the large slugs of water that can develop in Pumpkin Creek. The median annual flow of Pumpkin Creek (0.7 cfs) (tables 106 and 107) are considerably less than the median annual flows of Otter (5.2 cfs) and Hanging Woman (3.7 cfs) creeks (tables 102 and 104). Water quality data for Pumpkin Creek near its mouth (close to Hiles City) are available from the state WQB and from the USGS. However, the state WQB data are not very extensive, and the USGS initiated its water quality sampling pro- gram on Pumpkin Creek later than it did on the other streams in the Tongue River drainage. As a result, a great deal of chemical data are not yet available. Data for Pumpkin Creek near Miles City were inadequate for the seasonal classifications applied to Hanging Woman and Otter creeks; but the information was sufficient for a flow-based classification (tables 106 and 107). In 220 N N ..... TABLE 106. Summary of the physical parameters measured in the Pumpkin Creek drainage. Flow Temp pH sc TDS Turb TSS DO BOD FC Ca Mg TH Na K SAR HC03 TA so 4 Cl F N p Pumpkin Creek and Little Pumpkin Creek Pumpkin Creek near Volborg near Miles Citya N Min Max Med N 3 0.09 0.21 0.1 8 (40) 4 12.0 17.9 14.7 8 4 8.20 8. 50 8.35 8 3 5400 6570 5840 8 ( 1460) 3 4766 6315 5394 7 2 5 5 5 5 3 2.0 10 5.6 7 (228) 4 9. 1 10. 7 9.9 8 4 2.0 4.0 3.3 7 2 0 0 0 6 3 139 166 164 7 3 218 481 253 7 3 1314 2390 1391 7 3 956 1150 1050 7 0 -- ----4 3 9.3 13.4 11.5 7 3 643 920 673 7 3 542 754 572 7 3 2773 3700 3150 7 3 0.0 16 0.0 7 1 ----0.6 5 4 0.0 0.05 0.01 6 4 <.01 0.01 <.01 6 NOTE: Measurements are expressed in mg/1. aLess than 0.99 cfs. bGreater than 0.99 cfs. Min Max 0.05 0.7 1.1 22.B 8.20 8.62 1977 3545 1585 3063 6 15 11.4 41 9.3 12.4 2.2 5.9 0 12,700 58 81 35 69 289 484 325 780 10 13 7. 1 16.2 381 582 335 477 720 1580 5.4 12 0.3 0.6 0.0 0.95 0.01 0.05 Pumpkin Creek b near Miles City Med N Min Max 0.26 7 1.0 240 8.9 7 0.0 20.5 8.46 7 6.67 8.49 3130 7 247 4200 2729 7 188 3723 14 7 14 220 20.2 7 11.0 1830 10.3 6 7.4 12.7 2.8 6 3.0 >12 42 5 0 5000 67 7 10.4 141 58 7 6.1 176 393 6 51 477 680 7 26 720 12 4 5.8 17 14.0 6 1.4 12.0 472 7 73 517 397 6 60 340 1320 7 56 2140 9.0 7 3.0 12 0.5 5 0.1 0.5 0.03 7 0.02 0.45 0.03 7 0.01 0.41 Med 25 8.5 8.20 1380 1081 175 360 10.5 5.2 9 60 43 315 195 8.8 4.2 306 223 535 5.5 0.3 0.13 0.02 TABLE l 07. Sununary of the miscellaneous constituent and trace element con- centrations measured in the Pumpkin Creek drainage (mg/1). Miscellaneous Constituents and Total Recoverable Dissolved Metalsa Metals N Min Max Med NH -N 2 0.02 0.04 0.03 Si 3 l 8.4 TOC 2 10 30 20 Ag <.002 Al 0.03 As 6 < .001 0.004 <. 01 B 8 <. l 0 0.40 0.37 0.34 Ba 0.09 Be <.003 Bi < .013 Cd 16 < .001 < .01 < .001 0.0 Co <.013 Cr <.013 Cu 16 <. 01 0.04 < .01 0.01 Fe 16 <.04 13 0.34 0.07 Ga <.006 Ge <.02 Hg 9 <.0002 0.0026 < .001 Li 0.04 Mn 16 . 01 .36 .07 0. 01 Mo < .01 Ni <.013 Pb 5 <.01 0.05 <.05 <.013 Sn < .013 Sr 4 1.3 3.7 1.6 l.l Ti <.009 v 4 < .10 < .l 0 <. l 0 <.013 Zn 16 <. 01 0.08 0.01 0.0 Zr <.030 a N = l in a 11 cases 222 addition, some water quality information was collected by the state WQB from the upper reaches of Pumpkin Creek near Volborg (USDI 1968), and these data have also been included in tables lD6 and 107. The trace element and miscel- laneous constituent data from all reaches were combined for the statistical analyses; this information is also presented in tables 106 and 107. Pumpkin Creek can also be characterized by its high TDS concentrations and its distinct sodium sulfate water in all reaches during all seasons. The upper reach of Pumpkin Creek also had greater magnesium concentrations than calcium, although this relationship became much less noticeable near the stream's mouth. Fluoride, chloride, and potassium were insignificant constituents of the Pumpkin Creek samples, and magnesium-calcium and bicarbonate were the secon- dary cations and anion. TDS concentrations were highest in the upper reach of Pumpkin Creek near Volborg; they declined to the creek's mouth, showing a down- stream improvement in water quality, particularly during high-flow periods. The waters in Pumpkin Creek were moderately saline in the upper reach, slightly saline in the lower reach at low flows, and ~on-saline downstream about 40 percent of the time during the high-flow periods. The waters, how- ever, were very hard in most cases. Annual median TDS-SC levels in Pumpkin Creek near Miles City (1931 mg/1 and 2S64 ~mhos/em) were slightly less than the median values obtained in Hanging Woman and Otter creeks. TDS-SC levels were about 3.4 times and 3.0 times greater than the annual median levels of the Tongue River near Miles City (table 92). But the effect of Pumpkin Creek on the salinity levels of the mainstem near Miles City is slight. For example, at the median flows of the Tongue River near Miles City and lower Pumpkin Creek (about 0.7 cfs), this tributary would increase the annual median TDS level of the mainstem only about 0.4 percent. Median phosphorus and nitrogen (including ammania-N) concentrations were low in Pumpkin Creek and below the reference levels that indicate eutrophy. Only 18 percent of the samples from the stream had phosphorus in excess of the reference ~riteria, 12 percent had excessive nitrogen, and 6 percent had both phosphorus and nitrogen in excess of the reference criteria. With the exception of salinity (TDS-SC) levels and some of the dissolved constituents, the remain- ing major parameters did not suggest water quality problems. Pumpkin Creek has been designated a B-D 3 stream by the State of Montana. Sample pH values, although high in correspondence to the high alkalinities, were in accord with the criteria of a B-D3 classification. Values of pH were lowest at the Miles City station during the high-flow regimes when alkalinities were also low. The DO concentrations of the creek and the median fecal coliform counts were also in accord with the standards for a B-D3 stream; however, high fecal concentra- tions were obtained in occasional samples (lS percent) that exceeded the state recommendations for grab samples (Montana DHES, undated) and the NTAC (1968) permissible criteria for a surface water public supply. BODs values were also low in Pumpkin Creek, particularly during low flows, which indicates that no organic pollution reaches the stream. The slightly higher BODs concentrations during the high-flow periods; along with the above average TOC levels, indicate inputs of some organic material during this phase of the hydrologic cycle, but these somewhat higher BODs concentrations were most likely derived from natural sources, such as organic pickup in association with the overland flow that de- velops during these runoff events. 223 TSS-turbidity levels were greatest in the lower reach and during the per- iods of high flow; this has been observed on many streams in the Yellowstone Basin. At low flows, TSS concentrations and turbidity values would not be at levels high enough to significantly degrade the quality of the creek's water. At high flows, TSS and turbidity values were at sufficient levels to detract from the better quality of water characteristic of the stream at this time due to lower salinities. Turbidity during ~igh flows would generally preclude the use of the stream as a public supply (NTAC recommendation, table 9), and the median values of turbidity and TSS during runoff events (tables 106 and 107) could adversely affect the aquatic biota. But on a yearly basis, the annual median TSS and turbidity values of Pumpkin Creek (29.3 mg/1 and 15 JTU) would indicate a good fishery (European Inland Fisheries Advisory Commission 1965). As a result, salinity is the major detractor from the water quality in this stream, particularly in an upstream direction. Pumpkin Creek would provide a poor source of water for public and domestic supply and throughout the entire year in all reaches because of its high TDS levels. Only 12 percen~ of the samples had TDS concentrations below 500 mg/1, and all of these were obtained at high flows (29 percent of the runoff collec- tions). The high levels of sulfate and the extremely hard nature of the water in Pumpkin Creek would further preclude domestic use. Only 12 percent of the samples, all of which were collected at high flows, had sulfate concentrations less than 250 mg/1, and 88 percent of the samples had very hard waters. Pumpkin Creek would provide a poor source of water for stock; this would be most apparent in the upper reach near Volborg where the waters would be classified as unfit for most farm animals (Seghetti 1951). According to the EPA (1973), waters in upper Pumpkin Creek would be "permissible for livestock, (but) unacceptable for poultry and lactating animals" (USEPA 1973), and the TDS concentrations would be above the salinity threshold level for pigs (McKee and Wolf 1974). The waters in the lower reach of Pumpkin Creek were somewhat better for this use and applicable to most stock animals (tables 10-14). According to Seghetti (1951), the lower section of the stream can be classified as fair during low flows to good during high flows for agricultural supply. However, concentrations of individual ions would further delimit the value of this water as a source for stock. In upper Pumpkin Creek, sulfate concentra- tions were well above the limiting levels for stock, with sodium and magnesium slightly in excess of the proposed thresholds above which physiological effects may occur in consuming animals. In the lower reach, sulfate concentrations were also in excess of the limiting levels at low flows; they were greater than the threshold value for a large percentage of the time during the high-flow period. Consequently, the waters in Pumpkin Creek may be considered poor for most beneficial uses. Samples from Pumpkin Creek indicate that it has a very high salinity haz- ard for irrigation in its upper reach and also in its lower reach during low flows. In addition, the upper reach and the lower reach of Pumpkin Creek at low flows would also have a high-to-very high sodium hazard for irrigation due to the sadie nature of the water and the high SAR values. Because of this latter feature, Pumpkin Creek would be less suitable as a source of water for irrigation at low flows than Hanging Woman or Otter creeks, which have lower sodium hazards. 224 Low discharges may preclude the use of Pumpkin Creek for irrigation through a large part of the year, judging from the fact that its flows were less than 1.0 cfs on about 62 percent of the days monitored by the USGS (USDI 1966-1974a). With such a high proportion of low-flow days, Pumpkin Creek would have a poor class of water for a major part of the year. Nevertheless, about 3600 acres of land are irrigated from Pumpkin Creek (USDI 1974), but this usually occurs during the high-flow periods when water quantity and quality is greater. Waters in the upstream reach would probably be unacceptable for irrigation due to its extremely high TDS-SC and sulfate levels. The concentrations of these variables generally exceeded the minimum limits prescribed for a Class III water, and the TDS concentrations were greater than the maximum level listed by the EPA (1976) for application to tolerant plants. The best water quality for irrigation develops in Pumpkin Creek at high flows, which occur over about 38 percent of the year. It would seem that the lower TDS-SC and sulfate concen- trations downstream near Miles City at low flows would indicate a Class II water at these times, but the lower reach probably would retain its Class III water at low flows due to the high SAR values (tables 106 and 107). The median SAR, sulfate, and TDS-SC values indicate that the water is more appropriately Class II also, but water with TDS concentrations between 1000 mg/1 and 2000 mg/1 "may have adverse effects on many crops and requires careful management prac- tices" (US EPA 1976). Careful management practices would therefore be necessary in the use of this water for irrigation, even though it would be applicable to a wider variety of crop and forage species as a result of its lower salinities. Trace element levels in Pumpkin Creek did not generally suggest water quality problems (tables 106 and 107}; TR concentrations of most constituents were typically below the reference criteria. This includes Si (concentrations were below the national average), NHJ-N (at non-toxic levels), As, B, Cd, Cu, Pb, Sr, V, and Zn. Almost all of these constituents had low dissolved concen- trations. Although based on only one sample analysis, low dissolved concentra- tions eliminate the following trace elements as potential causes of water qual- ity problems: Ag, Al, Ba, Be, Bi, Co, Cr, Ga, Ge, Li, Mo, Ni, Sn, Ti, and Zr. Only Fe and ~In had TR concentrations high enough to exceed water qua 1 ity cri- teria; the dissolved levels of Fe and Mn were well below the reference ·criteria for water use. Additional analyses are necessary in order to adequately judge the potential effects of TR and dissolved concentrations of trace elements in Pumpkin Creek. POWDER RIVER DRAINAGE Powder River Maihstem The Powder River is the most eastern of the major tributaries that join the Yellowstone River in Montana. Its headwaters are on the eastern slopes of the Bighorn Mountains in Wyoming; it has an extensive reach in Wyoming and an extensive prairie reach and drainage in Montana before it joins the Yellowstone near Terry (USDI 1968}. Poor water quality might be expected in the Powder River due to its long length, providing opportunities for accessory inputs. On the basis of average annual discharge, the Powder River is about 1.44 times larger than the Tongue River, but only 16 percent as large as the Bighorn River (USDI 1974). However, on certain days, flows in the Tongue River exceed 225 those in the Powder. The Powder River has an average.annual discharge equal to about 5 percent of that in the Yellowstone River at Miles City. As a re- sult, the Powder could have a significant effect on mainstem quality, particu- larly if it has significantly poorer quality than the lower Yellowstone. How- ever, very little.water quality information is available on the Powder River. Since 1965, the USGS has sporadically sampled two stations on an upper reach of the Powder River above Broadus (table 3), and the USGS has initiated a monthly sampling program on this segment near Moorhead and at a downstream station near its mouth close to Locate. Also, the state WQB has collected several samples from the river at various locations along its length in Montana. The available USGS data and the state WQB data were combined to represent two segments of the stream--an upper reach from near Broadus to Moorhead close to the Montana-Wyoming border, and a lower reach below Broadus from near Locate to near Terry. With this combination of data, water quality information were sufficient for a seasonal classification of the two segments as summarized in tables 108 and 109. Of the major streams in the Yellowstone River Basin, the Powder River is unusual to have a definite sodium sulfate water with high TDS-SC levels,. even in its upper Montana segment. Many of the other large streams in the Yellow- stone Basin have calcium bicarbonate water, the Clarks Fork and Tongue rivers have calcium-sodium bicarbonate water, and the Bighorn River has calcium-sodium sulfate water. The major tributaries to the Yellowstone above Billings, including the Clarks Fork River, usually have TDS-SC levels less than 300 mg/1 and 400 ~mhos/em in the upper reaches, and TDS-SC levels typically less than 500 mg/1 and 600 ~mhos/em near their mouths (Karp et al. 1976a). The major streams below Billings (the Little Bighorn, Bighorn, and Tongue rivers) have SC levels ranging between 350 and 950 ~mhos/em in the upper reaches, depending upon season and the parti- cular stream, and between 550 and 1025 ~mhos/em in the lower segments. TDS concentrations in these rivers range between 200 and 625 mg/1 in the upper seg- ments and between 300 and 700 mg/1 in the lower sections of the streams, depen- ding upon season and drainage. The TDS-SC levels of the Powder were signifi- cantly greater than these values; TDS levels varied between 950 and 1650 mg/1, and SC levels between 1260 and 2175 ~mhos/em. The Powder River near its mouth had median TDS levels 2.74 to 4.18 times greater, and SC levels 2.30 to 3.62 times greater than those of the Yellowstone River near Miles City, depending upon reach and season. Evidence of the greatest differences between the Powder and Yellowstone rivers was obtained during the low-flow August-October period and the May-July runoff period of the year. The high TDS concentrations .of this major Yellow- stone tributary may be related to its long length from its headwaters in Wyoming to its mouth in Montana. The Bighorn River, which also has an exten- sive drainage system, also had comparatively high TDS levels (table 48). Flow patterns in both reaches of the Powder River (tables 108 and 109) were generally similar to those of the other large streams in eastern Montana. Flow was low in the late summer-early fall. Peak flows occurred during the May-July period due to runoff from the river's mountainous headwaters. Median seasonal flows consistently increased from the summer low through the winter and spring months to the May-July maximum, and a secondary peak in flow became 226 J N N ..... --.... ---- TABLE 108. Summary of the physical parameters measured in the Powder River near Moorhead~Broadus. August-October November-February March-April N Min Max Med N Min Max Med II Min Max Flow 18 7.7 302[ 109 16 87 1520 234 8 340[ 4930 Temp 19 2.0 28.5 14.2 21 0.0 5.0 0.0 10 0.5 10.0 pH 19 7.7 B.6 8.30 19 7.53 8.6 7.9 8 7.5 8.3 sc 18 1525 5000 2175 20 775 2800 2040 9 850 2300 lOS 18 1240 4080 1635 22 584 1710 1369 9 642 1755 Turb 10 5.2 390 30 12 20 300 68 5 125 1100 TSS 5 12.0 972 112 6 66 644 165 2 1240 2910 DO 18 7.6 11.6 9.4 18 3.0 12.6 10.4 9 7.0 12.0 BOO 12 0.7 4.1 2.0 12 1.5 8. I 3.1 6 2. 1 10.6 FC 9 0 100 24 11 0 270 20 5 20 180 Ca 15 105 228 150 19 79 160 130 9 58 143 M9 15 56 132 73 19 25 72 56 9 25 64 TH 18 493 1110 720 18 431 700 565 9 248 619 Na 12 190 300 220 16 66 310 240 8 62 320 K 10 6.0 17 B. 3 10 3.4 7.3 6.1 5 5.3 8.0 SAR 10 3.0 5.4 4. I 13 4.1 5.3 4.5 7 1.5 5.9 HC0 3 9 231 294 261 12 254 427 314 5 150 295 TA 12 190 246 217 12 209 350 259 5 123 242 504 16 570 1240 820 17 280 730 570 9 260 850 C1 13 35 230 93 19 36 260 160 9 10 180 (2.0?) F 12 0.3 0. 5 0.4 12 0.3 0. 5 0.4 7 0.2 0. 7 (2.2?) N 16 0.0 0.40 0.03 20 0.18 0.64 0.3 9 0.20 0. 5 p 16 0.0 1.9 0.04 20 0.01 0.82 0.08 9 0.02 1.7 NOTE: Measurements expressed in mg/1. May-July Med N Min Max Med 664 14 486 12,060 845 3.0 15 9.0 26.0 17.5 7.85 15 7.5 8.40 8.0 1750 15 624 2950 1350 1390 15 461 2230 954 300 7 180 8120 220 2075 4 1223 8900 1914 10.4 14 5.2 9.6 7.8 3.9 11 1.8 9.0 2.4 100 11 20 4100 350 130 14 52 130 90 56 14 12 50 35 560 15 196 1220 370 250 10 58 200 139 6.4 6 3.1 6.3 4.6 5. 1 9 1.8 4.2 3.5 272 8 116 189 162 223 10 95 160 139 660 15 193 690 439 120 14 23 100 75 0.6 8 0.0 0.6 0.4 0.40 15 0.0 0.93 o,25 0.40 15 0.01 2. 9 0.3 N N co TABLE 109. SuR~ary of the physical parameters measured in the Powder River near locate-Terry. August-October November-February March-Apri 1 N Min Max Med N Min Max ~led N Min Max Med Flow 8 33 265 166 6 154 700 308 4 732 4296 1520 Temp 7 4.5 19.5 17.3 7 0.0 2.5 0.0 4 1.0 18.0 4.3 pH 8 8.17 8.4 8.3 7 7.7 8.5 8.20 4 7.80 8.3 8.20 sc 8 1483 2250 2020 7 1700 2400 2140 4 1220 2998 2025 TDS 8 ll42 1870 1529 7 1210 1800 1460 3 993 2205 1530 Turb 7 4 5800 160 7 10 200 40 3 1000 > 1000 ll50 TSS 7 33 740 282 5 92 1750 206 4 4130 62,800 4965 00 6 8.0 12.4 10.3 7 11.2 12.8 ll. 9 4 5.1 10.8 7.3 (2. 7?) BOO l ----6.1 l ----4.6 2 2. 9 5.9 4.4 FC 6 30 7900 141 5 3 66 10 3 23 3100 27 Ca 8 74 145 Ill 7 97 160 120 3 77 190 120 Mg 8 53 80 56 7 43 74 54 3 35 79 56 TH 8 470 615 517 7 420 680 520 3 . 340 802 530 rra B 150 350 273 7 210 340 260 3 190 375 260 K 7 6.4 3.6 7.5 6 6. I 8. 7 6.8 2 7.4 8. l 7.8 SAR 8 3.0 6.3 5.2 7 4.0 5.9 4.7 3 4.5 5.8 4.9 IIC0 3 9 218 345 258 6 267 454 303 3 179 265 254 TA 8 179 241 215 7 219 372 250 3 14 7 217 209 504 8 545 970 745 7 500 740 600 3 490 1190 720 Cl 8 36 140 78 7 106 220 150 3 72 116 100 (4.5?) F 7 0.2 0.4 0.3 6 0. 3 0.4 0.4 2 0. 4 0.5 0.5 u 7 0.0 0.2 0.02 7 0.2 0. 57 0.3 4 0.07 0. 74 0.47 p 7 0.01 0. 72 0.10 7 0.03 0.62 0.10 4 0.01 l.l 0.51 1/0TE: f~ci.lsurcments expressed in 1ug/1. 0 GCi.-0 May-July N Min Hax Med 7 67 3600 1670 7 10.5 24.5 17. 5 8 7.68 8. 20 8.10 8 882 2309 1268 7 629 1797 1050 8 41 2150 505 7 1070 10,600 5530 7 6.4 9.9 7.6 4 2. l 6.4 5.7 7 65 1300 360 7 62 Ill 81 7 20 62 36 7 236 580 350 7 98 350 180 6 4.3 10 5.3 7 2.7 6.5 4.2 7 123 238 217 7 101 195 178 7 300 935 450 7 21 97 81 7 0.4 0.5 0.4 7 0.0 0. 38 0.18 7 <.01 1.5 0.04 I I evident during the March-April period, probably due to runoff from the low- lands area. At Locate, this secondary flow peak was almost equivalent to the May-July runoff value. Median flows also increased significantly in a down- stream direction in the Powder, from Moorhead to Locate, with this increase greatest during the two runoff periods. The downstream percentage increases by season were: August-October, 52.3 percent; November-February, 31.6 percent; March-April, 128.9 percent; and May-July, 97.6 percent. The Powder drainage in Montana therefore appears to contribute significantly to the volumes of water at the river's mouth. · Although the Powder River had an average annual discharge equal to about 5 percent of that in the Yellowstone upstream of its confluence, this percen- tage varied considerably between seasons as follows: August-October, 1.8 per- cent; November-February, 4.1 percent; March-April, 16.6 percent; and May-July, 6.3 percent. These variations in flow and the high TDS concentrations indicate that the Powder River could have a significant salinity loading effect on the mainstem, particularly during the March-April period. The potential effect of the Powder and Tongue rivers in increasing main- stem salinities is shown in table 110. TABLE 110. Calculated percentage increases in TDS of the Yellowstone River from Miles City to below the confluence of the Powder River. Powder River Powder plus Tongue Rivers Tongue River Aug-Oct 5. 1 5.9 0.8 Nov-Feb 8.1 9. 1 1.0 Ma rch-Apri 1 28.9 28.7 -0.2 May-July 18.2 lg.4 1.2 Annual Median 14.5 15.2 0.7 As indicated in table 110, the effects of the Tongue River would be negligible during the March-April season and small through the rest of the year. The Tongue would increase the annual median TDS level of the mainstem by only 0.7 percent, but the Powder would increase it by 14. 5 percent. The effects of the Powder are apparently smallest between August and February when flows in the tributary would be low, and these effects would increase through those months from summer to winter in correspondence to the increase in Powder flows. The influences of the Powder on mainstem salinities are greatest during the March- April period when its discharge would be high with high TDS concentrations. Intermediate effects would be obtained during the May-July runoff period when TDS levels in the Yellowstone River are low. Except during the March·-Apri 1 season, the median seasona 1 TDS concentra- tions in both reaches of the Powder River were inversely related to flow .. ·. The unusually high TDS-SC levels of the March-April season corresponded to the secondary peak in flow; the high salinities at this time probably reflected inputs from lowland runoff with an inferior water quality. Median TDS and SC levels tended to increase downstream in the river from Moorhead to Terry, although increases were not totally consistent in all seasons or for·both 229 parameters. They were highest during the November-April period, and slightly lower in the August-October season. Overall, downstream changes in Powder sal- inity were small. An annual median increase of 1852 mhos/em to 1872 mhos/em (1.1 percent) was evident downstream in SC from the Moorhead to the Locate reach. An annual median increase of 1335 mg/1 upstreatn to 1387 mg/1 (3.9 per- cent) near Locate in TDS also was evident between the two segments. TDS:SC ratios were 0.72 near Moorhead-Broadus and 0.74 at Locate-Terry. Although TDS loads increased greatly downstream in the Powder River because of accessory TDS inputs (from 1546 tons per day to 3067 tons per day annually), the overall TDS concentrations of the Montana input waters would not be very much higher than those of the mainstem, or significantly different from the TDS concentrations of small prairie streams. The following measurements were determined from the TDS load differences between reaches: August-October, 1326 mg/1; November- February, 1748 mg/1; March-April, 1639 mg/1; May-July, 1148 mg/1; and annually, 1444 mg/1. A fairly large percentage of the salt load in the Powder River was apparently obtained in Wyoming. Median values were between 70 percent and 71 percent during low flows, between 40 percent and 46 percent during the high flows, and 50 percent annually. Waters in the Powder River were extremely hard (Bean 1962, Durfor and Becker 1964) and slightly saline (Robinove et al. 1958) in both reaches in all seasons; 83 percent of the samples collected from the Powder had TDS concentra- tions in excess of 1000 mg/1. Sulfate and sodium, the dominant cation and anion, accounted for 60 percent to 62 percent of the annual median TDS concen- tration. Calcium and bicarbonate were the secondary ions, and fluoride and potassium were insignificant constituents. The Powder·River had high chloride concentrations, an unusual occurrence in the Yellowstone Basin. A large proportion of the chloride loading in the Powder was apparently derived from its Wyoming drainage, judging by the high chloride levels obtained from the Moorhead-Broadus samples (table 108). Chlor- ide concentrations then tended to decrease slightly downstream to the Locate reach. But the significant increases in chloride loads below Moorhead indi- cated supplemental inputs of chloride from the Montana portion of the river's drainage. Calculations based on the differences of chloride loads between reaches indicated that these Montana inputs would have overall chloride con- centrations ranging between 49 mg/1 and 118 mg/1, depending upon season. Calcium and magnesium tended to decrease slightly downstream, as did total hardness, contrasting to the river's significant downstream increase in sodium levels. As a result, the Powder River tended to become more sodic in character towards its mouth after passing through its prairie drainage, showing a defin- ite downstream decline in its Ca:Na ratios. Sulfate and bicarbonate concentra-I tions remained fairly constant throughout the river, and HC03:S04 ratios did I not decrease downstream in the Powder River as they did in the Yellowstone River and most other streams. Calcium concentrations exceeded magnesium levels in both reaches of the Powder River. Ca:Mg ratios tended to increase from the low-to the high-flow periods, and they tended to decline slightly downstream. The slightly saline nature of the Powder River and the high concentrations of some ionic constituents would be expected to lower the value of this stream for many water uses. Obviously, the river would not be expected to be a good source of water for public supply due to its high TDS, sulfate, and hardness 230 I (Ca + Mg) levels. About 99 percent of the samples from the Powder had TDS and sulfate concentrations in excess of the permissible criteria, recommendations, and standards established by the NTAC (1968) and the EPA (1973) for surface water public supply, and by the Public Health Service (1962) for drinking water (table 9). About 66 percent of the Powder samples had turbidity levels in ex- cess of the permissible level recommended for public supply (NTAC 1968). These levels were most common during the March-to-July high-flow season and they were highest in a downstream direction. The water in the Powder River would not be of ideal quality for irrigation because of a high salinity hazard during most of the year, along with a medium sodium hazard at certain times of the year due to the river's high sodium con- centrations and SAR values. The sodium hazard was greatest in the lower seg- ment near Locate and most common during the August-April period. As indicated by tables 15, 16, 108, and 109, the water in the Powder would be mostly Class II and should consequently be used for irrigation with certain restrictions. As noted by the EPA (1976), waters like those in. the Powder with salinities typically between 1000 and 2000 mg/1 of TDS--as in 75 percent of the samp 1 es from the Powder River--". . . may have adverse effects on many crops ... (requiring) careful management practices." The best water quality for irrigation from the Powder occurs, of course, during the high-flow, low TDS runoff period of May-July; however, the high TSS concentrations typical of this season may complicate irrigation use (USEPA 1973). Salinities in the Powder River may have some detrimental effects on the stream's aquatic biota since TDS concentrations and SC levels commonly exceeded 670 mg/1 and 1000 mhos/em, and were often greater than 1350 mg/1 and 2000 mhos/em, as shown in table 111. TABLE 111. Percentage of Powder River samples with TDS and SC concentrations in particular ranges. Upper Reach Lower Reach March-March- Low Flow Apri 1 Runoff Low Flow April Runoff TDS (mg/1) <670 3 11 20 0 0 29 670-1350 23 33 67 33 33 43 >1350 75 56 13 67 67 29 SC (JJmhos/cm) <1000 5 22 20 0 0 38 1000-2000 37 33 73 40 50 38 >2000 58 44 7 60 50 25 However, suspended sediment and turbidity levels of the Powder River may affect the stream's biota more than its salinity. The Powder should provide a good quality water for all livestock (USEPA 1973, McKee and Wolf 1974, Seghetti 1951), 231 but the river's sulfate concentrations appeared to be at levels that would de- tract from this good quality. As in many eastern Montana streams, sulfate con- centrations were commonly in excess of the threshold levels for domestic ani- mals (California WQCB 1963). TDS concentrations would not affect animals physiologically, but the sulfate levels of the Powder samples may do so, con- ceivably reducing stock production. Df the major parameters summarized in tables 1D8 and 1D9, salinity (TDS-SC), suspended sediment, turbidity, total hardness (calcium plus magnesium), SAR (sodium), sulfate, and possibly the critical nutrients (phosphorus and nitrogen) indicated water quality problems in the Powder River. None of the remaining major parameters (fluoride, chloride, bicarbonate-total alkalinity, and potas- sium) appeared to be significant. The Powder River has been designated a B-D 3 warm-water stream by the State of r~ontana. This _classification is appropriate considering the high maximum water temperatures obtained from the stream during warm-weather periods; the pH values and DO concentrations were also in accordance with a B-D3 classifi- cation. Low DO levels were measured in a few of the samples from the stream, but they were generally obtained in conjunction with high TSS levels. For the most part, the river was very close to oxygen saturation throughout its length, with median DO levels within S percent to .6 percent of saturation (table 112). The high DO levels of the Powder River suggest that no substantial organic pollution reaches the stream; and this was substantiated in the upper reach by the low BODs concentrations. BOD 5 values tended to increase downstream to the lower reach during all seasons, which suggests organic inputs between Moorhead and Terry. This was also indicated by the associated downstream increase in TOC levels and by the slight downstream decline in median DO saturation. These downstream increases in BODs were small, and occasionally high values approach- ing 10 mg/1 can be expected as a natural occurrence. The downstream BODs con- centrations near Locate were at insufficient levels to indicate that extensive organic pollution reaches the river. The small organic inputs to the Powder River seem to be more like those obtained from natural sources than from muni- cipal effluents, although the town of Broadus may contribute (USDI 1968). The annual median BODs loading to the Powder River would amount to about 8 tons per day, or only 8 mg/1. Fecal coliform concentrations also increased downstream in the Powder River, but not consistently through all seasons. Annual median fecal concen- trations ·increased slightly from 117 colonies per 100 ml near Moorhead-Broadus to 133 colonies per 100 ml near Locate-Terry. Coliform concentrations were not noticeably high in either reach, except during the runoff season, and seasonal l median concentrations were within the state's average criteria in all months except May to July. About 16 percent of the samples had coliform concentrations in excess of the state's criteria for grab samples. This percentage was slight- ly greater than the 10 percent leeway prescribed by the state for a 30-day period (table 8). However, 78 percent of these grab sample excesses occurred during the high-flow period when high fecal counts would result from overland runoff. Only 7 percent of the grab samples had fecals in excess of the NTAC (1968) and the EPA (1973) recommendations for public supply. Fecal strep levels in the Powder River were also low (table 112), and the annual median fecal coli- form:fecal strep ratio (0.83) indicates a "predominance of livestock and poultry 232 I j TASLE-llZ Su:u.!ry of e~i!.cell.!neous constituent .!nd trace ele!:ll'nt concentrations ~.!lo;urcd In the PCNQer River Near Moorhead·Bro.!du~ 1:eo1r Locolte·Tcrr:y Mi see 11 aneous Mi~cellaneous t~~~~ t !!~~~!~d~~:.!l constituent\ o1nd Dissolved IICtdlsb total recoverable r.-etals r.-euh Ois\olved II!Clah " Hlo .... "" " Min "" ,.,, II Min ..... ... , II Min "" "'' Color 4 9 " " "' 8 0.0 .01 0.0 oo' 15 31 108 " 15 " 104 94 reca I strep " ll 970 110 HIIAS " 0.0 .06 .005 flli3·11 J3 0.0 0.61 O.DB Sl " 3.3 " 6.8 15 .., " 8.3 Tot 1 ----6 s 6.6 5l J3 "' 14 0.0 c .00) 0.0 ( .002) " 6 3. 6 270 14 ' o.o .OJ .02 ,, 10 < 001 a. Jso 0.006 1l 0.0 .006 0.0 9 < .001 0.060 0.008 s 0.0 .002 .001 8 6 < 10 0.42 0. \9 '" .10 .89 .26 6 <.10 0.20 0.18 .. ' 0.0 .01 0.0 (d Z3 0.0 0.02 .003 14 0.0 .002 0.0 15 ' 001 0.01 <.01 5 0.0 .001 0.0 Co ' 0.0 < .025 .001 5 < .05 0.15 <.as ' 0.0 .001 .0005 ,, 12 0.0 0.50 <.01 6 0.0 .10 .OJ 5 0.0 .01 0.0 ,, " < .01 0.90 0.02 15 0.0 .030 .00, 15 <.01 0.22 0.02 5 .003 .008 .005 ,, Z3 0.09 600 6 ] " 0.0 .39~ .030 15 0.03 170 '. 3 5 .02 .15 .06 H9 " 0.0 .0011 ~.001 11 0.0 .0000 .0002 9 < .0002 (,001 ;:1.0002 5 0.0 .0003 .0001 Ll 2 .06 .06 .06 ,., " < .01 6.8 0.26 IS 0.0 .240 .017 14 0.03 14.0 0. 46 5 0.0 .01 0.0 ,., 1l 0.0 .OJ I .003 /li 14 0.0 .030 .005 Pb 11 <.01 0.80 <. 10 " 0.0 .008 .0005 10 <. 10 0.20 (. 10 s 0.0 .oo• .002 Se ' 0.0 .008 .002 " 0.0 .011 .002 s .00\ .oos .002 s .001 .003 .002 ,, ' 1.20 2.43 1.4) 3 . 50 1 . s 1.4 ' ' 0.0 <.006 . 0017 3 ' OS '· 10 .OS '" Z1 <.01 1.0 o.os 16 0.0 .180 . ozo 15 ' 01 1.8 0.05 5 .02 .04 .02 r:QTE: Hca!.urel:ll'nt'> are eJpressed in ~-9/1. bat>: <0.01. N•l1; Cr: <.01, 11"9, cOO e)(pressed as percentage of saturation. 233 wastes in mixed pollution" (Millipore Corporation 1972). Data presented here indicate that bacterial contamination of the Powder River, including that from human sources, is not a major water quality problem. Phosphorus concentrations were high in both reaches of the Powder River (tables 108 and 109); the median concentration exceeded the reference criteria for eutrophication in 75 percent of the seasonal periods. About 60 percent of the samples from the Powder had phosphorus levels in excess of 0.05 mg P/1, and 49 percent of the samples had concentrations greater than the reference levels established by the EPA (l974b) for eutrophication. The high phosphorus levels were possibly related to the river's high TSS concentrations as the median phos- phorus values tended to increase downstream from Moorhead to Locate except during the May-July period. Nitrogen concentrations were also high in the Powder River except during the summer. Nitrogen concentrations showed warm-weather low median values in August-October and high concentrations during winter and spring. However, the river was nitrogen-limited, with median nitrogen concentrations lower than or closer to the reference level than was phosphorus. About 32 percent of the samples from the Powder River had nitrogen concentrations in excess of 0.35 mg N/1, but only 1.2 percent had levels in excess of the EPA's (1974b) more strin- gent criteria for eutrophication. The river was non-eutrophic during the cri- tical summer season due to the low median nitrogen concentrations, but if median ammonia concentrations are considered (table 112), the river was potentially eutrophic during the less critical and coole1· November-to-Apri 1 period because both median phosphorus and nitrogen levels would exceed reference levels at this time. During the May-July period, the river was limited in either nitro- gen (Moorhead reach) or in both nitrogen and phosphorus (Locate reach), although the upper reach had median concentrations approaching eutrophic levels. The Powder River came closer to eutrophy than most of the streams and reaches in the Yellowstone Basin. On a yearly basis, about 29 percent of the samples from the Powder River would be expected to have both nitrogen and phosphorus in ex- cess of their reference criteria, but only 0.4 percent of the samples would have both of these nutrients in excess of the reference levels established by the EPA (1974b). Probably the most distinctive water quality features of the Powder River in all reaches are its high suspended sediment concentrations and its high tur- bidity values. At low flows median TSS concentrations in the Powder near Locate were between 3.3 and 8.9 times greater than those in the Yellowstone River near Miles City in comparable seasons. Median turbidities were between 4.4 and 13.9 times greater in the Powder than in the mainstem. Maximum TSS concentrations in the Powder near Locate during the low-flow seasons were as much as 9.7 times higher than the maximums recorded at low flows in the Yellowstone above the confluence of the Powder. Such high TSS concentrations were most noticeable during the March-July high-flow periods at which times high median TSS-turbidity values were obtained in excess of 2000 mg/1 and 200 JTU and particularly high values were obtained from some grab samples. The 62,800 mg/1 value recorded in table 109 is espec- ially noticeable; 33 percent of the sample volume was due to settleable solids (Karp et al. 1975). At high flows, median TSS levels in the Powder near its mouth were between 64 times (during March-April) and 12 times (during. May-July) 234 higher than those in the Yellowstone near Miles City, and maximum values were between 149 times and 9.3 times higher than the maximums obtained from the main- stem. High flow turbidities were between 3.6 times (during March-April)· and 32 times (during May-July) higher than those in the Yellowst"one near Miles City, and maximum values were between >1.3 times and 11 times higher than the maxi- mums obtained from the mainstem. Consequently, the Powder River would be ex- pected to have a considerable influence on mainstem water quality. The potential of the Powder and Tongue rivers to increase mainstem sus- pended sediment concentrations is shown through the loading calculations pre- sented in table 113. TABLE 113. Calculated percentage increases in TSS in the Yellowstone from near Miles City to below the confluence of the Powder. Powder River Powder plus Tongue Rivers Tongue River Aug-Oct 14.2 13.2 -1.0 Nov-Jan 9.2 6.3 -2.9 March-April 900.0 863.0 -37.0 May-July 66.7 63.6 -3. 1 Annual Median 84.6 80.8 -3.8 These percentages suggest that the Tongue River should have a negligible effect on the TSS levels of the Yellowstone mainstem. Comparisons of the TSS data in tables 57 and 92 indicate that inputs from the Tongue River would reduce the TSS concentrations in the mainstem below the confluence (between 0.6 percent and 2.7 percent) since the Tongue had lower TSS levels than the Yellowstone near Miles City during all seasons. As shown in table 113, the Tongue, through the addition of water volume, would negate the subsequent effects of the Powder on mainstem TSS concentrations. The Powder River would significantly increase mainstem TSS levels, but this increase would be small during the August.-to- October period when flows and TSS concentrations would be low, The most sig- nificant effects would be obtained during the March-April season (the secondary runoff peak) when flows of the Powder would be high in comparison to those of the mainstem. Intermediate effects would be observed during the May-July sea-. son because the high flow-high TSS inputs from the Powder would be less notice- able due to the high Yellowstone flows and the high TSS levels already devel- oped in the mainstem from upstream sources. On a yearly basis, the Powder River could increase the annual median TSS level of the Yellowstone about 85 percent; the Tongue would decrease TSS levels by about 4 percent. The Powder River is therefore responsible for a net annual median accrual in TSS of nearly 81 percent from Miles City to Fallon. Suspended solids concentrations were related to flow in the Po~1der River (tables 108 and 109). Median TSS .concentrations consistently increased down- stream through all seasons, indicating a downstream degradation in water quality. Median TSS concentrations increased by the following percentages from the Moor- head-Broadus to the Locate-Terry reach in each season: August-October, 152 percent; November-February, 25 percent; March-April, 139 percent; May-July, 189 percent. Annual median TSS levels increased from 914 mg/1 upstream to 235 2365 mg/1 near Locate, an increase of 159 percent. Median TSS loads in the upper reach of the Powder ranged from 33 tons per day to 104 tons per day dur- ing low flows (August-February) and ranged from 3720 tons per day to 4367 tons per day during high flows (March-July). Median TSS loads were significantly higher in the lower reach, ranging between 126 tons per day and 171 tons per day and between 20,376 tons per day and 24,935 tons per day for the same sea- sonal periods. This marked downstream increase in TSS loading in the river suggests significant inputs of suspended sediment from the Montana portion of its drainage. Comparisons of the TSS loads in the two reaches indicate that the Wyoming portion of the Powder drainage would contribute only 18 percent to 26 percent of the suspended sediment in the river between March and October and 61 percent during the winter. The drainage above Moorhead would contribute between 40 percent and 71 percent, depending upon flow, of the river's TDS levels. Loading calculations indicate that inputs of water from the Montana drain- age would require median TSS concentrations between 336 mg/1 and 507 mg/1 during low flows, and between 7207 mg/1 and 9234 mg/1 during high flows in order to account for the increase in suspended sediment in the Powder from Moorhead to its mouth. Such high calculated concentrations indicate that some of the TSS in the river probably comes from natural bank and stream bottom erosion and from channel redefinition in addition to surface water confluences. During low-flow periods with a stable discharge and reduced surface runoff, suspended sediment levels in the Powder are significantly lower and are probably derived from these autochthonous actions. This type of scouring continues throughout the year and would be greatly increased during periods of greater discharge. However, during the high-flow periods, the marked increases in TSS that occur are also probably due in part to inputs from overland flow and surface runoff with the associated erosion of adjacent lands. In any event, the high TSS levels of the Powder indicate readily erodible soils in the region. The high salinities of the Powder River indicate poor water quality, re- stricting many beneficial uses of the stream. This is reinforced by the high suspended sediment levels of the stream which further restrict water uses. The Powder would be a poor source of water for public supply because of its high turbidities and its high TDS levels. About two-thirds of the samples collected from the Powder had turbidities in excess of the 75 JTU permissible level for this parameter (NTAC 1968). The high TSS concentrations of the stream could also cause indirect problems and expense to irrigation use by tending ". . . to fi 11 cana 1 s and ditches, causing serious cleaning and dredging pro- blems" (USEPA 1973). In addition, the application of irrigation waters with high TSS concentrations could tend" ... to further reduce the already low infiltration characteristics of slowly permeable soils ... " (USEPA 1g73), assuming that such soils are present in the Powder drainage. The apparent erodibility of the adjacent lands, attested to by the high TSS levels of the river, indicates that this is the case. This in turn further complicates irrigation and other agricultural pursuits through the need for more careful management practices. The high TSS level of the Powder River would be expected to adversely affect the aquatic biota. The annual median TSS concentrations of the stream suggest a very poor fishery (European Inland Fisheries Advisory Commission 1965). A resident fishery in the Powder might be somewhat different from the 236 rest of the Yellowstone Basin because of its requisite adaptation to high silt loads; the unique occurrence of the sturgeon chub in the Powder drainage is possibly related to this fact (Karp et al. 1975). However, migrant warm-water game fish have been observed in the river, and this stream is apparently used as a spawning ground by various species originating in the Yellowstone (Peterman 1977). The high TSS-turbidity levels of the Powder may have added effects on the biota by reducing primary production in the stream through the sediment's scouring action on the benthos and through decreased light penetration. Klarich (1976) observed that the high turbidities of the Clarks Fork River apparently kept production below the potential inherent in the river's nutrient concen- trations. This could also apply to the Powder River, which had significantly greater turbidities than the Clarks Fork (Karp et al. 1976a). Such restric- tions of primary production could affect other aspects of the river's biota. The Powder River also had high TR concentrations of several trace elements in both reaches (table 112). High TR concentrations of Al, Fe, and Mn have been observed in the Yellowstone River and many other streams, but they were much higher in the Powder samples. The TR concentrations of Co, Cr, Cu, Pb, and Zn were also high in the Powder collections, unlike those in most of the other waters of the Yellowstone Basin. The low dissolved concentrations of many of the trace elements--Al, Ag, As, B, Ba, Be, Cd, Cr, Co, Cu, Li, Mo, Ni, Pb, Se, and V--indicate no potential water quality problems; maximum and median dissolved concentrations were well below the reference criteria. The high TR levels of the Powder samples were probably related to their high TSS concentrations, and because the Powder had significantly greater suspended sediment levels than most of the other streams, higher TR concentrations might be expected as a natural development. In addi- tion, Si, Sr, MBAS, ammonia, and cyanide were not at levels high enough to in- dicate water quality problems or pollution inputs. However, the Powder River was somewhat colored (i.e., color greater than 10 units), and this, along with the high turbidities, would indicate aesthetic degradation of the stream. Therefore, color, Fe, Hg, Mn, and Zn appear to be the greatest potential water quality problems in the Powder River. In the upper reach, the maximum dissolved concentrations of Fe and Mn exceeded the reference criteria for public supply and drinking water (USEPA 1973, NTAC 1968, USOHEW 1962), and, along with zinc, also exceeded the criteria for aquatic life (USEPA 1973). Such problems would be expected to be occasional in the· upper segment, however, since the median dissolved concentrations were below the reference levels. In the Locate-Terry reach, Fe, Mn, and Zn concentrations did not indicate water quality problems at any time. Of the metals, mercury appears to be the great- est continual problem to aquatic life and municipal supply; the median and grab sample dissolved concentrations often equalled or exceeded water-use criteria in both reaches (tables 9 and 19). Of the samples from the Powder analyzed, 44 percent had dissolved Hg equal to or greater than 2.0 ~g/1, and 56 percent had dissolved Hg equal to or greater than 1.0 vg/1. 237 Little Powder River The Little Powder River and Mizpah Creek are the Powder River's two major tributaries in ~lontana. Mizpah Creek has a rather extensive drainage area lo- cated entirely in Montana adjacent to Pumpkin Creek drainage; it joins the Powder from the southwest about 37 miles upstream from Terry near Mizpah (USDI 1968). The Little Powder River has most of its drainage in Wyoming, with only a short 34-mile segment located in Montana before it joins the mainstem from the southeast near Broadus ( USDI 1968). Both of these tri buta ri es tend towards intermittency with extremely low flows recorded through part of the year; zero flows have been observed in both streams (USDI 1966-1974a). This intermittency, however, is greatest in Mizpah Creek, particularly in the upper reaches. Mon- tana's Little Powder is probably more perennial than intermittent because it is ponded throughout the year. The annual average discharge of both streams is low--39.6 cfs in the Little Powder River (USDI 1966-1974a). The volume of water in these two tributaries is not at adequate levels to account for a very large percentage of the 290 cfs annual median downstream increase in mainstem flows from Moorhead to Terry. Some water quality data are also available from the USGS on the Little Powder (USDI 1966-1974b) as a result of a past sampling program (table 3). These USGS data, combined with several state WQB collec- tions from the stream, were adequate for a seasonal classification (table 114). The chemical composition of the Little Powder's water was similar to that of the mainstem. TDS concentrations and SC levels were generally the same in both streams, although they were slightly higher in the smaller river (27 per- cent to 39 percent on an annual basis). This correlates with the downstream increase in TDS in the Powder. Waters of both streams were extremely hard and slightly saline (Bean 1962, Dur.for and Becker 1964, Robinove et al. 19S8). The Little Powder River also had a definite sodium sulfate water, and calcium and bicarbonate were the secondary ions. As a result, SAR values were also high. As in the Powder River, calcium concentrations exceeded magnesium levels, and potassium and 'fluoride were insignificant constituents of the samples. Chlor- ide concentrations were significantly lower than those of the Powder, and po- tassium concentrations were slightly higher. The critical nutrient concentra- tions in the Little Powder were also significantly lower than those in the mainstem, and the smaller stream was obviously non-eutrophic during all seasons. TSS-turbidity levels were high in the Little Powder River, but not as high as those in the Powder River. This tributary would apparently not contribute sig- nificantly to the downstream increases in TSS loads that characterize the main- stem; the median TSS concentrations were only between 14 percent and 46 percent of those in the Powder near Broadus. TSS concentrations and flow were directly related in the Little Powder, but the maximum flows and TSS levels were ob- tained during the March-April season, suggesting an early prairie runoff. The Little Powder River has been classified a B-D3 stream by the State of Montana, which is appropriate considering the high max1mum warm-weather temp- eratures obtained in conjunction with grab samples. Values of pH and concen- trations of DO and fecal coliforms were also in accord with this B-D3 designa- tion (table 8). Although median BODs levels were slightly higher in the Little Powder samples than in most water samples from the Yellowstone Basin, maximum values were not very different from those obtained in Beauvais Creek. Median BODs values were also high in the lower Powder River (table 109). The low maximum BODs values suggest natural lowland prairie streams rather than organic 238 "" w "' TABLE 114. Summary of the physical parameters measured ln the Little Powder River near the Montana-Wyoming state line and near Broadus. August-October November-February ~1arch-Apri 1 May-July N ~lin ·f-lax Med N Min Hax Med N f.lln Max Med II Min Max Hed Flow 7 O.DE 0.40 0.06E 6 O.OE 17 0.80 6 <. 1 E 95 35.5 11 1.4 55 8.8 Temp 7 10.2 26 19.4 3 0.0 3.3 D. 1 3 1.0 11.0 9.0 9 13.8 28.5 20.0 pH 7 7.5 8.4 8. 30 5 6.95 8.20 7.87 4 7. 27 8.17 8.03 9 7. 8 8.6 8.24 sc 7 2245 4056 3210 5 789 4950 1846 4 564 3050 2557 9 1300 3003 2049 TOS 7 IBIS 3386 2810 5 609 4487 1420 4' 389 2163 1615 9 924 2364 1630 Turb 4 6 31 22 2 7 49 28 3 24 225 150 6 28 260 88 TSS 2 24.2 54 39.1 4 9.8 122 76 5 42 5100 485 6 74.5 950 276 DO 3 7.6 8.9 8.2 2 11.6 12:3 12.0 2 10.2 11.5 10.9 5 6.0 9.9 9.5 ODD 2 3.2 4.2 3.7 2 5.2 > 11.6 >5.2 2 5. 9 9.6 7.8 3 3.0 6.6 4.9 FC 4 0 880 89 3 0 380 0 1 ----0 4 25 340 138 Ca 7 42 160 138 5 30 258 93 4 25 114 106 9 75 170 102 M9 7 39 159 115 5 16 162 57 4 12 78 62 9 39 122 102 TH 7 326 922 831 5 143 1310 467 4 109 586 520 9 374 926 516 Na 7 410 720 580 5 125 910 24 7 4 72 430 302 9 151 456 282 K 7 7.5 20 19 4 4.5 23 15 4 8.0 14 8.8 8 12 18 14 SAR 7 6.6 10.9 9. 9 5 4.1 11 . 3 5.0 4 3.0 7.7 5.8 9 3.4 7.5 5.2 HC0 3 7 189 473 390 5 148 732 320 4 123 431 317 9 165 472 337 TA 4 251 388 347 3 121 423 262 3 101 354 290 3 212 371 278 504 7 820 2160 1740. 5 250 2620 686 4 106 980 855 9 540 1240 BOO Cl 6 1.0 28 15 5 4. I 35 17 4 9.0 123 45 9 4.2 45 8.4 F 7 0.2 0.6 0.4 4 0.1 1.2 0.6 4 0.2 2. I 0.4 8 0.3 I .4 0.5 N 6 0.02 0.05 0.02 4 0.04 0.17 0.08 4 0.00 0. 14 0.10 9 0.0 0.18 0.01 p 5 0.0 0.01 0.01 2 <.01 0.03 <.03 3 0.02 0.19 0.02 6 <.01 D. 10 0.035 NOTE: Neasurements expressed in mgjl. inputs from pollution sources. This supposition is supported by the low TOC concentration of one sample from the Little Powder River (table 115). The major water quality problems in the Little Powder River appear to be essen- tially the same as thos.e in the Powder River but not nearly as severe. Water quality problems evident in the Little Powder were salinity (with high TDS-SC levels), hardness (with high magnesium and calcium concentrations), SAR (with high sodium levels), sulfate (with high concentrations), and possi- bly turbidity and suspended sediment (with high levels). The associated water- use restrictions can be summarized as follows: 1) For use as a surface water public supply and drinking water, the waters had high hardness and turbidity. Also, TDS and sulfate levels were generally in excess of reference criteria (table 9). 2) For livestock watering, the water had high sulfate concentrations commonly in excess of the threshold (November to July) or the limiting (August to October) levels. This may produce physiolo- gical effects (California WQCB 1963), but the TDS concentrations indicated a fair-to-good/very satisfactory class for all live- stock (tables 10-14). 3) For irrigation, the water had a high-to-very high salinity hazard and a medium sodium hazard (USDA 1954), and a Class II water due to the high SAR, sulfate, and TDS-SC levels (tables 15 and 16) that " ... may have adverse effects on many crops (table 17) (requiring) careful management practices ... " (USEPA 1976). 4) For aquatic life, the water had high TDS and SC levels commonly in excess of 1350 mg/1 and 2000 ~mhos/em (Ellis 1944). This was true in 72 percent of the Little Powder samples in which TDS was measured and in 68 percent of the samples in which SC was measured. Annual median TSS-turbidity levels (62 JTU and 186 mg/1) suggest a fair warm-water fishery in the stream (European Inland Fisheries Advisory Commission 1965). High TR concentrations of Al, Fe, and Mn were obtained in correspondence with high TSS levels. Low TR and dissolved concentrations of As, B, Be, Cr, Li, Mo, Ni, Pb, Sb, Se, V, and Zn were obtained, indicating no water quality problems. Low dissolved concentrations of Al, Cd, and Cu were obtained, but their TR 1 eve 1 s exceeded various reference criteria. However, only Fe and Mn levels were high enough to adversely affect at least two water uses--public supply/drinking water and aquatic biota. Mizpah Creek Drainage Not much historical water quality and flow information is available on Mizpah Creek (USDI 1966-1974a, USDI 1966-lg74b); however, the USGS has initiated a sampling program on this stream (table 3) (USDI 1976). The state WQB has also sampled this stream as a part of two water quality inventories (Karp et al. 1975, Montana DNRC 1974). Combining the data from these two agencies allowed for a flow-based (although not a seasonal-based) classification of 240 ~-· ' ~- Trilil[ 115. SuliiTla,·y_of mhcellaneous constituent ant! trace clCII't'nt concer>tration~ J:"CCJSured in trlbutuies to the Powder Ri~er. oo' liH 3-N Sl TOC AI A; B ,, Cd ,, '" ,, Hg li "" "' ~~ i Pb Sb Se v '" Lit tie Powder River near the r1on tana-lo'yomi ng state 1 inc MHpah Creel <lnd Ti!~<l r ero~du~ Misccll.mcous Miscellaneous constituents andb constituents ood total recoverable tota 1 rccove r<~.b 1 e no~tals Dissolved r.-ctal s ~tals " 11in "" "'' " ~\in r'>o~• ~l,·d N Min "" ' 58 60 ' 0.0 .13 _(')4 12 3.0 14 10 ' 14 IS 1 .. .. 12 4 0. 32 s 00 3. I~ ' 0.0 0. 0 0.0 I .. .. 6 < 001 0.020 0.007. 1 0.0 0.0 0.0 ' 0.0 U.Ol6 16 . .10 U. 26 O.W 4 .00 .14 . \75 6 <. 10 0.4 ' O.{J ~ .01 .: ,(Jl IG '.001 () .010 0.001 ' o.u IJ.OOI , .. 001 IS < .001 < .01 s 0.0 .01 0.0 ' 0.0 0.0 0. 0 I .. .. IG < .01 u OG 0.01 ' .002 .OOJ .007.5 IS <.01 0 OG 24 " 1. 8 .6< 4 0.0 1.10 D. SS 15 . 28 6 ; 6 0.0 < .001 . 0004 ' 0.0 (').001')1 < .0001 6 < .001 .Ofll ' .03 ·" .O.l 2 .03 .05 ·" 16 .03 1.J .13 ' .05 .II .00 15 .02 .91 ' .001 .005 .002 ' .02 . 05 '03!1 4 ··.OS 0.05 <.OS ' .00~ .007 .om, 1 .001 .004 .007.5 1 .. .. 1 .. .. 0.0 I .. . . 0.0 ' . 001 .002 .001 ' .001 .001 .001 1 .. .. I .. .. .10 ' .00[)6 .oozo .0013 1 .. .. 16 < .01 0.08 0.01 ' 0." 0.010 0.005 15 ~. 01 0.05 /101[: lo\e<~.surc~nts an~ given in mg/l. aSanr1 <lnd Sheep creek~. upper l~iz[lah Cree~ near '/olbor'), lower ~lizpnh Creek near 1-!lzpah. bBe: <.01, N·4·, Pb: <.100, 1:=5. cOO c•pressed .as percentage of saturat1on. 241 ~led 64 IS .OS < .001 0. \9 ·: .001 ( . 004} 0.0 -:.01 ·" < .001 .13 <. 100 0.0 . 80 0.01 ( '21 ?) drainagea Dissolved rnet.JIS " !~.in l'·d~ ' .27 . 35 ' .(J3 -:J2 ,., . Jl .115 water quality information available on the lower segment of the stream near Mizpah. Statistical summaries of the data from the upper reach of Mizpah Creek and from the two Mizpah tributaries are presented in table 116. The ldgh maximum wat"lll-weather temperatures, pll values, and DO and fecal coliform concentrations in samples from the Mizpah Creek drainage were gener- ally in accord with the B-D3 designation applied to these .waters (Montana DHES undated). In 15 percent of the samples high fecal counts in violation of the state's coliform standards were obtained, particularly in the upper reach, but for the most part, fecal concentrations were well within permissible criteria for a surface water public supply (NTAC 196B). This and the fact that BOD5 concentrations were low indicates that no municipal-organic pollution reaches the drainage. The streams in the Mizpah drainage had very low critical nutrient concen- trations, indicating that they are probably non-eutrophic. The major water quality problems and water-use restrictions appear to be related primarily to salinity and to the high concentrations of particular ionic constituents. Iron and manganese could detract from the quality of their water, and TSS-turbidity levels could restrict certain water uses, primarily municipal-public supply. However, levels of these parameters were below those in the Little Powder River, and they were not remarkable compared to other streams of the Yellowstone Basin. In general, therefore, suspended sediment and turbidity do not suggest water quality problems in Mizpah Creek except during portions of the high-flow periods. Mizpah Creek near Mizpah did not have TSS levels or flows high enough to con- tribute to the marked downstream increases in suspended sediment loads observed on the Powder mainstem. The TDS-SC levels of the Mizpah Creek samples and their chemical composi- tions were similar to those obtained from the Little Powder River, although ionic concentrations were significantly higher in the two Mizpah tributary streams. The waters were extremely hard (Bean 1962, Durfor and Becker 1964) in the Mizpah drainage; they were slightly saline in Mizpah Creek and moder- ately saline in the tributaries (Robinove et al. 1958). These streams had a definite sodium sulfate water with high SAR values, and calcium-magnesium and bicarbonate were the secondary ions. Fluoride, chloride, and potassium were observed in very low concentrations. Water quality problems and water-use restrictions in Mizpah Creek would be generally the same as those in the Little Powder. The low chlori.de levels of both the Little Powder River and Mizpah Creek were well below the calculated overall chloride concentrations of input waters to the Powder (49 mg/1 to 118 mg/1); this suggests that other significant sources of water reach and affect the mainstem (possibly groundwater). 242 - N ..,. w TABLE 116. Summary of the physical parameters measured in the Mizpah Creek drainage. Sand and Sheep creeks Upper Mizpah Creek near 1 lower Mizpah Creek near (Mizpah Creek tributaries) Volborg I Mizpah (<1.0 cfs) N Min Max Med N Min Max Med ~ N Min Max Med Flow 2 0.0 0. 0 0.0 4 0.0 0.1 0.05, 5 .-:. 1 E 0.9 0.4 Temp 2 11.0 16.0 13.5 4 1.0 g_3 1.9 4 10.3 23.3 15.0 pll 2 8.41 8.50 8.46 4 7.62 8.20 7.75 5 8. 30 8. 73 8. 70 sc 2 5010 5530 5270 4 1923 3752 2770 5 2092 8391 3020 TDS 2 4D98 4819 4459 3 196D 3307 197D 4 1695 3923 2414 Turb 2 25 180 103 4 2 18 3 4 7 40 33 TSS 1 -- -- 55 2 2. 6 25 13.8 5 15 70 46.0 DO 1 ----6.9 4 6.6 9.8 8.5 4 7.5 10.0 9.0 BOD 1 ----3.2 2 1.5 4.7 3.1 3 1.5 5.9 3. 1 FC 2 56 60 58 2 10 408D 2045 5 D 48D 196 Ca 2 36 115 76 3 130 256 140 4 38 114 4& Mg 2 40 121 81 3 7D 241 72 4 38 83 50 TH 2 256 784 520 3 61D 1632 650 4 282 626 3D8" Na 2 1160 1188 1171 3 375 42D 420 4 410 1090 5D7 K 1 ----9.7 2 8.8 9. 1 9.0 3 11 14 12 SAR 2 18.5 31.6 25.1 3 4.0 7.4 7.2 4 8.6 26.2 13. 3 !IC0 3 2 756 923 840 3 470 621 608 4 349 548 519 TA 2 628 783 706 3 385 509 499 4 310 507 444 504 2 20P.6 2456 2271 3 1000 1945 1000 4 814 2141 1171 C1 1 ----3.) 3 7· 20 9 4 0.5 8.9 8.1 F 1 ----1.2 2 0.3 0.3 0.3 3 o.; 0.7 0.5 N 1 ----0.0 J. 0.0 0.02 0.0 3 0.0 0.03 0.0 I' 1 ----O.U2 1 IJ.O 11.01 fJ.CI 3 O.!Jl 0.07. 0.02 t;QT£; f.,CdSUr'r'lliCOUa cxprc~SCd in lil!J/1. Lower Mizpah Creek near Mizpah (>1.0 cfs) N Min Max Med 6 1.5 95 18 6 0.3 2g.2 5.4 6 7.24 8.58 8.15 0 440 2370 1832 6 310 2029 1410 5 18 170 36 6 25.0 6000 105 6 7.6 12.2 10.3 6 3.2 11.2 5.9 4 D 145 5 6 16 87 60 6 2.4 58 43 6 79 457 323 6 56 43D 302 4 3.6 10 7.3 6 2. 7 8.8 7.4 6 89 416 331 6 73 343 272 6 132 102D 67D 6 0.8 6.2 4.0 4 0.1 0.4 0.4 6 0.01 0.42 0.17 fi 0.01 0. 36 D.03 YELLOWSTONE RIVER POWDER RIVER TO. MONTANA-NORTH DAKOTA BORDER YELLOWSTONE MAINSTEM The USGS has maintained a single water quality irrigati.on network station on the lower Yellowstone River near Sidney for several years (USDI 1974), and the state WQB has also made collections. from various sites on the lower river in recent years. Appropriate data from these two agencies were combined and seasonally classified to represent a reach of the Yellowstone River near Sidney. These data confirm that between Corwin Springs and Miles City, the Yellowstone River had significant and consistent downstream increases in TDS and ionic constituent concentrations during all seasons. Calculations of po- tential TDS loading to the mainstem from the Tongue and Powder rivers suggestea that such concentration increases would continue below Miles City to the river's mouth near Fairview. Also, salinity-related water quality problems and assoc- iated water-use restrictions probably would be greatest and most critical in the lower reach of the river. State WQB data from the upstream locations below Miles City were separately combined to represent another river reach west of Sidney between Terry and In- take (USDI lg68); in this manner, the water quality data from the Terry-to- Intake sampling sites could also be seasonally classified. Information from the Sidney reach was the most extensive due to the USGS's longer sampling per- iod, and the data were therefore directly comparable to the Yellowstone River data near Miles City (table 57). Less.valid comparisons can be made between the Terry-Intake reach and the Miles City or Sidney segments because little data is available on the Terry-Intake reach. Statistical summaries of data on the major water quality parameters are presented in table 117 for the Terry-to-Intake reach and in table 118 for the Sidney segment. Data for the miscellaneous con- stieuents and trace elements were not seasonally classified, but they were sep- arated by reach as shown in table 119. The lower Yellowstone River had definite seasonal variations in nitrogen levels. Extremely low nitrogen concentrations were noted during the warm late summer-early fall season of high biological activity. High nitrogen concentra- tions developed in conjunction with the colder temperatures of the dormant winter season. However, no distinct downstream trends became evident from <1 Miles City to Sidney. Phosphorus concentrations tended to increase downstream in the lower river during the March-to-July period and remained constant through the remainder of the year. Like nitrogen, phosphorus also demonstrated a seasonal variation in concentration, but the higher concentrations 1~ere recorded during the high-flow, high TSS periods of the year (March-July). At least some phosphorus variations in the lower Yellowstone were probably correlated with alterations in suspended sediment levels. The river was apparently non-eutrophic and usually N-limited in all reaches during most seasons; this was most noticeable during the critical August-October period. During the winter, the median total soluble inorganic nitrogen concen- trations in the lower river (including the median ammania-N levels) exceeded the 244 .. , I TABLE 117. Summary of the physical parameters measured on miscellaneous sites on the Yellowstone River between Terry and Intake. August -Oc taber Novembcr-Februa ry f-1ilrch-Apri 1 Hay-July N f-1in Nax l·led N Nin f-1ilx Med N f-1i n Max Med II Min f-lax fled Flow 9 8300 14,700[ 10,800 6 6000E 10,200 8295 4 9430 15,500 13,300 10 9760E 61 ,500E 26,200 Temp 10 6.5 22.8 19.0 9 0.0 3. 5 0.0 4 0.5 16.5 9.0 17 10.5 24.6 16.1 pH 12 8.0 8.8 8.5 9 7. 97 8.6 8.3 4 7. 70 8. 3 8.15 17 7.5 8.40 8.09 sc 11 478 840 570 10 686 910 760 4 560 1144 878 16 290 910 475 T05 9 315 508 418 8 467 564 535 4 441 847 609 17 173 514 349 Turb 6 6 230 15 5 10 45 30 2 190 >1000 --11 40 280 205 T55 8 12 147 24.5 3 8 84 78 2 61.4 118 84.7 13 90 1930 740 DO 12 8.0 12.0 9.4 9 11.3 13.8 12.6 4 7.4 11.2 10.1 17 7.1 10.0 9.0 BOD 5 0.9 2.5 2.5 3 2. 9 3.8 3.0 2 1.6 3.9 2.3 13 0.6 6.3 3. 9 FC 4 2 29,400 22.350 3 10 32 19 1 ----104 10 <10 855 300 Ca 9 39 59 5i 8 58 75 63 4 50 71 70 17 25 59 41 fig 9 15 23 20 9 15 28 25 4 23 38 30 17 7. 8 23 16 TH 9 161 240 210 8 212 300 254 4 220 333 295 17 95 240 170 Na 9 40 70 55 8 56 75 65 4 65 123 90 17 19 66 44 K 7 2.8 4.0 3.4 8 3.4 4.1 3.7 3 4.3 4.8 4.5 13 2.0 3.6 2.7 5AR 9 1.4 2.0 1.6 8 1 . 5 2.0 1.8 4 1.9 2.9 2. 3 17 0.9 1.8 1.4 HC0 3 9 145 195 177 8 184 235 196 4 169 214 213 17 93 174 140 TA 8 119 160 146 9 151 193 158 4 139 176 175 17 76 143 115 504 9 120 191 180 8 175 270 210 4 190 372 280 17 57 220 136 Cl 9 5.5 13 8. 2 8 5 15 13 4 15 31 20 17 3.2 13 8.0 F 7 0.1 0. 4 0.4 8 0.3 0.4 0.4 3 0.4 0.6 0.6 17 0.2 0.7 0.3 N 9 0.0 0.21 0.02 7 0.2 0.5 0. 36 4 0.18 0.32 0.25 16 0.03 0.52 o. 27 p 9 0.0 0.28 0.03 7 0.0 0.06 0.04 4 0.01 1.4 0.30 17 <.01 1.5 0.41 IOOTE: Measurements expressed 1 n m9/l. TABLE 118. Surnnary Of the physical parameters measured in the Yellowstone River near Sidney, Montana. August-October November-February March-April May-July N Min '1ax 1·1ed II Min Max Med N Min Max Med N mn Max Med Flow 56 2804 17,000 9395 78 3080 18,200 7408 44 4900 35,800 10,050 72 3737 73,200 23,750 Temp 34 4.5 25.0 15.3 41 0.0 8.5 1.5 23 0.5 12.0 6.1 38 10.0 26.0 19.5 pH 62 7.4 8.9 8.0 84 7.3 8.9 8.1 47 7.4 8.5 8.0 77 6.4 8.6 7.9 sc 56 440 939 678 74 460 1050 817 41 562 1050 844 72 274 934 509 TDS 55 271 629 434 72 280 719 545 41 404 684 570 69 158 647 309 Turb 14 4 70 24 15 4 70 8 9 28 920 100 17 30 680 195 TSS 18 20 2910 274 14 44 270 117 14 79 3120 300 23 82 4630 676 DO 25 7.4 11 .6 9.2 27 9.2 12.6 11.4 15 7.2 11.6 9.8 26 7.0 9.8 8.1 BOO 14 1.0 3.5 2.0 15 0. 7 5.3 1.5 10 1.2 3.2 2.1 17 0.7 4.5 1.9 FC 21 0 13,400 36 22 0 108 10 15 0 400 20 26 0 2500 165 Ca 27 40 62 54 37 41 89 65 22 46 78 62 35 23 63 40 Mg 29 15 27 22 37 14 36 26 21 13 33 26 38 7.9 29 14 TH 52 164 291 222 68 160 363 279 37 170 330 259 63 90 283 165 Na 48 42 100 60 68 39 97 73 35 47 100 78 64 20 96 42 K 26 2.8 6.7 3.7 41 2.7 5.8 4.2 26 3. 9 6.4 4.7 36 2.1 5. 5 3.0 SAR 50 1.3 2.6 1.8 68 1.4 2.3 1.9 37 1.5 3.1 2.1 62 0.9 2.5 1.4 HC0 3 50 145 220 187 64 126 275 221 37 153 236 204 63 90 277 156 TA 17 121 175 140 18 144 204 168 7 126 185 164 17 77 167 105 504 50 120 224 180 71 100 305 233 38 139 304 240 68 47 288 124 Cl 29 4.4 19 9.4 37 6.6 20 13 25 8.4 21 15 38 3.6 23 7.0 r 26 0.2 0.8 0.4 37 0.3 0.6 o. 5 25 0. 3 0.8 0.4 38 0.2 0.6 0.4 N 36 0.0 0. 39 0.02 44 0.0 0.60 0. 30 30 0.0 0.6 0.16 51 0.0 0.69 0.15 p 33 0.0 0.24 0.06 38 0.0 0.17 0.04 21 0.01 1.4 0.18 34 0.01 2.7 0.30 IWTE: 1·1easurements expressed ln ·mg/1. If.[IL[ 119, Sur:-.rn.,ry of ~~iscell.lneous r.onHitu1~nt and trace elel'hl!nt concentration~ rr..easun:od in the VciJowo,tone River bett~C"r.n Ierrv an1 near the "'ontana-rlorth Oa~ota border. Mhce11anffius sites between Terry 01nd Intake Yellowstone ~iver ne01r Sidney Miscl'llaneous Mtscello~ne<lus conHituents <~nd constituenu and tot" I recoverdble tot.sl n-covero~ble Oissohcd noto~lsb meta Is Dissolved ~toll~ ~t4ls 11 N Min "" ""' cou Color oo' 22 19 \04 91 reca 1 stn~p MBAS NH 3 -N ' 0.01 o.zo 0.09 (I. Z1) II TOC A9 AI ,, 0 .. Oo Cd ,, '" ,, "' Ll ,., "" Iii Pb I• I' v '" 21 1.8 12 9.8 6 ' \5 " ' .30 " 4.9 6 <.01 .014 .007 " <' 10 o. ~z 0.10 23 < .001 0.01 ~. 001 6 ( .01 0.56 0.02 26 ~ .01 0.08 0.01 23 .OJ " 8.4 15 0.0 0.0017 "-.0002 21 .01 3. 8 .ll II <. 01 0.100 .._ .05 ' 0.0 .004 .002 14 .05 3. I .10 15 .:.OS <. 10 (. 10 27 < .01 0. 47 0. 0~ NOTE: Meuurerrents e•Prl!SseQ 111 rrrtJ/1. <ICo: < OS,N•2. bSe; <.01. /1•3. Co: 0.0. N•Z. c.oo e~tll"'eSSI'd .,., percento~ge of >aturo~tion N "'" ''" ""' 0 --.. -- I 0.0 0.01 cOl I 0.0 . 007 .004 12 . 070 .160 .HS I <. 10 <. 10 <",10 I 0.0 0.01 < 01 3 o.o .ooz 0 0 I 0.0 .01 0.0 4 .001 .001 .003 14 0.0 .OB .01 1 .02 .01 .04 " 0.0 .01 0.0 ( .261) 3 .001 .002 .0!)2 3 .002 .001 .ooz 4 .001 .004 .001 6 .001 .003 .ooz I .19 .61 .60 6 0.0 .002 .001 6 0.0 .05 .01 247 " Min ... Mt~d N Min . .... Hcd 16 " 64 20 . 3• I 20 I 41 63 109 " 22 I 700 21 " 0.0 .04 0.0 II 0.0 ·" .06 109 I. 9 , 10 " '.0 27 4.9 4 .41 42 " 9 .0001 .02 .0002 ' .003 .034 .007 I .001 .DOS .003 9 .-.10 0.30 0.10 so 0.0 .23 . 11 15 < .001 0.01 "'.01 5 0.0 .001 0.0 ' 0.0 0.05 0.01 I 0.0 .01 0.0 14 .-.01 0. 14 o.oz I .002 .010 .004 14 .04 ll 1.5 81 0.0 2.6 .04 12 0.0 o.oooa .-.oooz I 0.0 .0007 .0002 I .0046?) 3 .02 .05 .OJ 15 .01 .97 .06 39 0.0 .12 .00. 3 .001 .001 .002 3 0.0 .003 .003 14 ~ .01 0.100 "'.05 5 0.0 .003 JXll ( .0151) 6 .001 .003 .002 5 .001 .002 .001 8 .06 1.3 .44 6 < .05 0.10 <. 10 3 .0003 .ooz .002 14 < .01 0. )] 0.05 5 .01 .02 .01 reference criteria, and phosphorus was limiting with median concentrations below its reference point. Throughout the entire year, 64 percent of the samples from the lower river had phosphorus concentrations exceeding the reference levels, and 47 percent of the samples had phosphorus greater than the EPA's (1974b) cri- teria for eutrophication. None of the samples had nitrogen in excess of the EPA's (1974b) criteria, and only 25 percent of the collections had nitrogen levels greater than or equal to 0.35 mg N/1. Only 16 percent of the lower river samples suggest eutrophy. The high maximum grab sample temperatures obtained from the lower reach during warm-weather seasons (22DC to 26DC) are in accord with its B-D 3 designa- tion (Montana DHES, undated). The lower Yellowstone is a warm-water fishery (Perman 1977), and except during the winter, median grab sample temperatures tended to increase downstream from Miles City to Sidney. Dissolved oxygen con- centrations and pH values were also appropriate for a B-D 3 classification. Med- ian seasonal pH values in the Sidney reach were measured at 8.0 units, and a slightly lower median pH was measured during the runoff season in correlation with greatly reduced alkalinities. With two exceptions (both from the Terry-to- Intake reach with its reduced sample sizes), median fecal coliform concentra- tions were also within the state's average criteria. Near Sidney (table 118), only 12 percent of the collections had fecal counts in excess of the state's criteria for grab samples, very close to the 10 percent monthly leeway that is allowed by state standards (table 8). Only 5 percentof the samples exceeded the permissible criteria for surface water public supply (table 9). In the Terry-to-Intake reach, however, the somewhat higher median fecal values and the extremely high grab sample concentrations obtained on occasion (table 117) suggested pollution problems, possibly derived from municipalities (Miles City, Terry, and Glendive). In the Terry-to-Intake reach, 38 percent of the samples exceeded the state's grab sample criteria for fecals (far above the 10 percent leeway factor), and 14 percent had concentrations greater than the recommendation of 2000 colonies per 100 ml for public supply (USEPA 1973, NTAC 1968). Apparently the problem lessens towards Sidney with flow time and assoc- iated die-off. In addition, although the annual median fecal strep concentration of samples from the river ne·ar Sidney were low and did not suggest pollution in- puts (table 119), the annual median fecal coliform:fecal strep ratio (2.1) indi- cated municipal contamination and human wastes in mixed pollution (Millipore Corporation 1972). Consequently, municipal-bacteriological pollution is a mild water quality problem in some segments of the lower Yellowstone with a subsequent recovery further downstream. Although the biological parameters suggested pollution inputs to the lower river, this was not reflected in the oxygen data. DO concentrations were always well above the state's minimum requirement for a B-D~ stream. Median DO concen- trations were with 5 percent to 9 percent of saturat1on, and 67 percent of the grab samples from the lower river had DO levels within 10 percent of saturation; only 12 percent of the samples had DO levels less than 80 percent of saturation. The seasonal variations in median DO concentrations were probably inversely re- lated to seasonal changes in temperature. Low median DO levels were measured during the May-July period (8. 1 mg/1 to 9.4 mg/1) in relation to the high median temperatures (15.JOC to 19.5DC). High median DO levels were obtained between November and April (9.8 mg/l to 12.6 mg/1) in conjunction with the low median temperatures of this period (o.ooc to 9.ooc). 248 DO levels, the low TOC concentrations (the median value was near the nation- al average for surface waters), and the low COD and BODs concentrations indicate that there is no extensive organic input to the lower stream. For example, the maximum BODs concentrations obtained from the lower river were only S.3 mg/1 in the Sidney reach and 6.3 mg/1 in the Terry-to-Intake segment; much higher natural BODs concentrations have been obtained from unpolluted streams in eastern Mon- tana.· Of the lower Yellowstone samples, 89 percent had BODs levels less than 4.1 mg/1; 89 percent of the high values occurred during the May-July runoff sea- son. Much higher BODs, TOC, and COD concentrations, and much lower dissolved oxygen concentrations and percentages of DO saturation would have been expected considering the marked organic pollution entering the lower Yellowstone River. TDS concentrations and SC levels increased downstream in the Yellowstone River from Miles City to Sidney during all seasons, as seen in table 120. TABLE 120. Percentage increases in TDS concentrations and SC levels downstream in the Yellowstone River from Miles City to Sidney. August to October November to February March to April May to July Total Dissolved Solids 11.0 13.1 12.6 19.8 Specific Conductance 13.0 9.4 11.0 24.1 Downstream increases in salinity were fairly similar through a large part of the year in the lower Yellowstone (August to April) and much greater during the low TDS runoff period. The percentages given in table 120 for TDS increases indicate that the loading calculations made for the Tongue and Powder rivers to the Yellowstone were underestimated for the August-to-February low-flow periods at S.9 percent and 9.1 percent, and they were greatly overestimated for the March-to-April early runoff season at 28.7 percent. The 19.4 percent calcula- tion was fairly accurate for the May-to-July period. Annual median TDS concen- trations increased by 13.8 percent from Miles City to Sidney, close to the 1S.2 percent value predicted from the loading calculations. The calculated concen- trations confirmed that the Tongue and Powder rivers have significant effects on mainstem salinity. Discrepancies between the actual and calculated percentage increases of TDS might have been caused by incomparability of station data due to different per- iods of collection. A shorter sampling period, and thus a smaller sample size was obtained on the Powder River (table 109) than on the Yellowstone near Miles City and Sidney (table 3). The downstream increases in TDS suggest a degradation of water quality in the lower Yellowstone River to Sidney, and a large proportion of this degradation appears traceable to the confluences of the Tongue and the Powder rivers. However, the marked effect on the Yellowstone predicted during the March-to-April high-flow/high TDS period apparently did not occur in the mains tern. 249 The Yellowstone tends to become progressively more sodium sulfate downstream due to inputs originating from the lowland sodium sulfate tributary streams. As a result, Ca:Na and HC03:S04 ratios consistently declined downstream until the river, for all practical purposes, became sodium sulfate in its Sidney reach; annual median Ca:Na and HC03:S04 ratios were less than 1.0 in this segment. The river's sodium sulfate character was greatest in the lower Yellowstone during the March-April season in correlation with the secondary peak in mainstem flow originating from lowland runoff (adding sodium sulfate, high TDS waters); the river's sodium sulfate character was least obvious during the May-July runoff period from the basin's mountainous headwaters regions, which had predominantly .calcium bicarbonate, low TDS inputs. Salinity in the· lower Yellowstone was also greatest during the March-April period of lowland runoff, and, as a result, the inverse relationship between flow and TDS-SC was poorly defined through this season. However, calcium-sodium and bicarbonate-sulfate concentrations were not as dissimilar in the lower Yellow- stone as they were upstream; magnesium, therefore, can be considered the secon- dary ionic constituent in the lower reach. Fluoride, chloride, and potassium had insignificant concentrations. Chloride levels were somewhat higher in the Sidney than in the Miles City segment, possibly resulting from Powder River in- puts (table 109). In addition to the mild coliform problem described previously and the poten- tial water quality problems from certain trace elements, the major features de- tracting from water quality in the lower Yellowstone River were related to TSS and TDS. The waters in the lower river were hard during the runoff season and very hard between August and April. They were non-saline throughout the year. Except for TDS, total hardness, and sulfate, none of the remaining dissolved ionic constituents, including fluoride, appear at levels that would preclude water use. Median TDS concentrations in the lower river from November to April were greater than the permissible criteria and standards for pub 1 i c· supply and drinking water in both the Terry-to-Intake and Sidney reaches (table 9). During this six-month period, 81 percent of the samples from the lower river had TDS levels in excess of 500 mg/1. From August to October, 22 percentof the collec- tions had TDS levels exceeding 500 mg/1, compared to only 10 percent of the run- off samples. As a result, the lower Yellowstone, judging from salinity levels, would be a poor source of water for public supply from late fall through spring, but may have an acceptable water quality from May to October. The high turbidities of the lower Yellowstone would further degrade and probably preclude the use of the water for municipal supply during the March- April season and also during the May-to-July period of low TDS levels. Median turbidities during these two periods in both reaches exceeded the 75 JTU per- missible criteria for public supply (NTAC 1968), and 82 percent of the grab sam- ples from the lower river had individual turbidities greater than this level. Thus, the August-to-October season, with its low TDS concentrations and low tur- bidities, would appear to be the only season in which the lower Yellowstone might be directly applicable as a public supply without extensive treatment. Water hardness and high sulfate concentrations would also detract from the value of the lower river as a municipal supply, as sulfate concentrations were oc- casionally in excess of the recommended levels for this use (USEPA 1973, NTAC 1968, USDHEW 1962). . 250 The 1 ower Yellowstone River at present has an excellent water qua 1 ity for agricultural use, including the watering of all stock animals. The lower river also has a medium-to-high salinity hazard for irrigation, depending upon season, and a low sodium hazard. It has a Class I water for irrigation due to the low boron (table ll9), SAR, chloride, sulfate, and TDS-SC levels (tables 15 and 16). Waters with TDS concentrations less than 500 mg/1 are generally those " ... from which no detrimental effects will be usually noticed ... " (USEPA lg76) on plants after irrigation, including salinity-sensitive species. About 45 per- cent of the samples from the lower segment had TDS concentrations in excess of 500 mg/1, which would indicate that the above description does not apply to the lower Yellowstone much of the time. However, a significant number of samples with such high TDS levels were collected during the winter season, which had high median TDS values; the river usually would not be used for irrigation dur- ing this period. The proportion of high TDS samples was much lower during the irrigation season in correlation with the lower median TDS concent'rations as follows: May to July, 10.5 percent and August to October, 11.9 percent, as opposed to November to February, 80.0 percent and March to April, 82.2 percent. Therefore, effects of salinity on irrigation would be expected to occur mostly during the March-April period. Although the EPA's (1976) description of an excellent irrigation water ap- plies to the lower Yellowstone, the water has annual median TDS values of 472 mg/1 in the Terry-to-Intake reach, and 463 mg/1 in the Sidney reach. The lower river, therefore, appears to have borderline quality for irrigation and is par- ticularly susceptible to future degradation that might result in salinity in- creases. For example, an overall increase factor of only 1.5 in salinity could significantly reduce the lower river's value as an irrigation supply, particu- larly during the August-October season, by greatly increasing the proportion of samples with TDS concentrations in excess of 500 mg/1. Sensitive crop and forage species would then be affected (table 17). Salinity levels in the lower Yellowstone River should have mild, if any, effects on the aquatic biota judging from the small percentage of samples which had TDS concentrations in excess of 670 mg/1 (3.3 percent) and SC levels in ex- cess of 1000 ~mhos/em (2.1 percent). None of the samples from the lower river had TDS and SC levels greater than the more critical 1350 mg/1 and.2000 ~mhos/em values for freshwater biota, and 30.5 percent and 32.3 percent of the samples had TDS and SC levels less than 400 mg/1 and 600 ~mhos/em. Most collections had TDS- SC levels between 400 and 670 mg/1 and between 600 and 1000 ~mhos/em (66.2 per- cent and 65.5 percent) which, according to Ellis (1944), are accP.ptable levels of salinity for the support of viable and mixed fish fauna in western alkaline streams. However, the high suspended sediment concentrations of the lower Yel- lowstone and the associated high turbidities could have a much more significant effect on the stream's biota than would salinity, particularly in the Sidney reach. TSS-turbidity levels in the lower Yellowstone usually varied directly in response to the magnitude of flow; extremely high median and maximum values were obtained in both reaches of the lower stream during the May-July runoff period. TSS concentrations in excess of 1000 mg/1 and approaching 5000 mg/1 were obtained in some samples, with turbidities in excess of 100 JTU. In the Sidney reach, high median TSS~turbidity levels were also observed during the early spring secondary runoff phase, and high levels were noted even during 251 the August-to-February low-flow periods. However, TSS concentrations and tur- bidities were significantly lower in the upstream Terry-to-Intake reach from August to April. The annual median TSS-turbidity levels in the Terry-to-Intake segment of the lower Yellowstone (231 mg/1 and 70 JTU) would indicate a poor-to- fair fishery, and the higher values in the Sidney reach (327 mg/1 and 74 JTU) would sugges-t a poor fishery in the extreme lower reach of the river. The high turbidities of the 1 ower river could a 1 so affect the aquatic biota by reducing light penetration and retarding primary production (Klarich 1976). The high TSS levels of the water could also indirectly affect the use of the lower Yellowstone for irrigation by reducing soil permeability and clogging ditches and canals, which would lead to the extra expense of periodic dredging (USEPA 1972). The lower Yellowstone River would thus appear to have only fair water quality, at best, leading to curtailment of various water uses because of its high suspended sediment levels. Such high suspended sediment concentrations in the lower Yellowstone were deemed likely on the basis of the high TSS levels in the Powder River with the associated TSS loadings to the mainstem. Distinct increases in TSS were pre- dicted for the reach of the river below Miles City, and comparisons between tables 57, 117, and 118 indicate that TSS-turbidity levels did in fact consis- tently and significantly increase from the Miles City reach, through the Terry- to-Intake segment of the stream. Percentage increases in TSS through the lower river from Miles City to Sidney can be summarized by season: August-October, 764 percent; November-February, 88.7 percent; March-April, 287 percent; and May-July, 48.2 percent. Annual median TSS levels increased by 108 percent from Miles City to Sidney, slightly higher than the 81-percent increase predicted by the Tongue-Powder loading calculations. These comparisons indicate that the Powder does have a significant effect in degrading mainstem quality through the introduction of suspended sediment, although the slight discrepancy between the observed annua 1 median concentration and the ca 1 cul a ted TSS 1 eve 1 fndi cates the operation of other influential factors and inputs. The Tongue-Powder loading calculations (6.3 percent and 13.2 percent) for TSS were considerably less than the observed increases below Miles City during the low-flow August-February period, and calculations were considerably greater (863 percent) than the actual increase during the March-April season. The ob- served and calculated (64 percent) values were similar during the May-July runoff period. Marked downstream increases in TSS were observed during all seasons in the lower Yellowstone River, with a significant portion of this increase attri- buted to inputs from the Powder River. As observed in the Powder River and several other streams, the TR concen- trations of Al, Fe, and Mn were generally greater in the lower Yellowstone than those from upstream sites on the mainstem. The maximum TR concentrations of Cr, · Du, and An were also high. Suspended sediment levels also increased downstream in the Yellowstone in correlation with the greater TR values of the lower reach samples. In turn, the dissolved concentrations of most of the trace elements were low, and they did not suggest water quality problems. Only iron and man- ganese indicated occasional water quality problems; a few of the samples from the Sidney reach (less than 8 percent) had dissolved concentrations in excess of most reference criteria listed in tables 9-14 and 19. Mercury was a more 252 continuous problem in the lower segment, as its median and maximum concentra- tions exceeded the reference criteria for public supply and-aquatic life. In general, the dissolved levels of Al, As, B, Ba, Be, Ca, Co, Cr, Cu, Li, Mo, Ni, Pb, Se, Sr, U, and Zn in the lower Yellowstone would not be expected to degrade the water quality in the stream. This may be said also of the stream's miscellaneous constituents: Si had concentrations close to the national average for surface waters; TOC-COD-fecal strep levels indicated no problems; ammonia was at non-toxic levels but was at levels high enough to be a potential eutroph- icant; MBAS indicated no synthetic detergent inputs; color was generally absent, indicating no aesthetic degradation except by turbidity; and the insecticides- herbicides ~1ere generally undetectab 1 e--speci es were detected in only 4 percent of the analyses performed by the USGS (1966-1974b) in concentrations ranging from 0.01 ~g/1 to 0.05 ~g/1. O'FALLON CREEK DRAINAGE The Yellowstone River has a rather extensive reach about 150 miles below the confluence of the Powder River before it leaves Montana and enters North Da- kota near Fairview, Montana. No large tributaries enter the river through this segment, but numerous small streams do (USDI 1968), many of which are inter- mittent in nature. This probably accounts for the absence of distinct and con- sistent increases in TDS-SC between the Terry-to-Intake and Sidney reaches of the mainstem (tables 117 and 118). For example, the Terry-to-Intake segment had -an annual median TDS concentration of 472 mg/1, and the downstream Sidney reach had the very similar value of 463 mg/1. O'Fallon Creek, with its small flows, is representative of the small tributaries entering the extreme lower segment of the Yellowstone (table 121). Individual TDS loading effects on the Yellowstone mainstem from streams of this nature would be expected to be small, although a number of them could produce a cumulative effect. Due to the distance of O'Fallon Creek from the currently active coal fields, and due to its rather inconspicuous nature, very little water quality information is available on this small drainage basin. The state WQB, however, has made several collections from near the stream's mouth near Fallon plus a few collec- tions from the upper reaches of the creek near Ismay. The state WQB has also obtained a few samples from two of O'Fallon's major tributaries, Sandstone and Pennel creeks. These data were insufficient for a seasonal classification, and a flow-based separation of data from O'Fallon Creek near its mouth failed to reveal the occurrence of definite flow-related trends found to occur in Mizpah Creek (table 116). The data on this small drainage were separated by stream and reach, but were statistically summarized without the application of additional classifications (table 121). O'Fallon Creek and its tributaries are lowland streams, and this is gener- ally reflected in the chemical composition of their waters. Like many of the prairie streams, O'Fallon, Sandstone, and Pennel creeks have a distinct sodium sulfate water with high SAR values and dissolved solids concentrations; calcium- magnesium and bicarbonate were the secondary cations and anion of the waters. In most cases, calcium and magnesium concentrations were closely equivalent, and chloride, fluoride, and potassium were found in insignificant proportions. The waters in the O'Fallon Creek drainage were generally extremely hard (Bean 1962, 253 TABLE 121. SUll1tlary of the physical parameters measured in the o•rallon Creek drainage. Uppor O'Fallon Crook Lower O'Fallon Creek Sandstone Creek near Ismay near Fallon near Plevna Pennel Creek near Ismay II Min Max Mod N Min Max Mod II Min Max Mod II Min Max Med flow 4 0.05 6.6 0.28 7 0.1 85.E 15.4 3 0.0 3.5 <.IE I ----<.2E Temp 5 9.0 21.0 14.3 10 0.2 26.2 13.5 3 7.5 18.5 14.8 I ----20.0 pH 6 8.20 9.24 8.35 12 7.60 8.65 8. 25 4 7.60 8. 70 8.08 I ----8.50 sc 6 2458 3440 3000 12 685 2890 1623 4 1380 3993 3440 I ----4530 TOS 5 1943 2505 2235 12 522 2290 1326 3 1084 3171 2645 I ----3796E Turb 4 21 88 36 12 <I 750 33 3 62 96 74 0 ------ TSS 4 26 170 94.3 11 0.0 4550 59 3 37.5 228 180 0 ------ 00 2 9.5 9.8 9.7 11 7.5 12.3 9.7 2 7.3 9.4 8.4 0 ------ BOD I ----2.3 11 1.6 11.6 4.8 D ------0 ------ FC 3 D 430 80 10 0 6000 105 3 20 120 90 0 ------ c. 5 33 80 60 12 25 83 54 3 45 79 53 I ----370 Mg 5 o.o 74 61 12 19 75 50 3 28 98 61 I ----70 TH 5 180 450 400 12 140 514 320 3 230 602 384 I ----1214 11a 5 410 650 540 12 81 500 283 3 235 750 650 I ----688 K 3 8.2 10 9.6 10 1.8 11.0 7.9 2 9.7 10.8 10.3 I ----10 SAR 5 8.4 18.3 11.7 12 2.1 9.6 7.3 3 6.7 14.4 13.3 I -- -- 8.6 HC0 3 5 403 583 549 12 147 437 273 3 255 582 500 I ----342 TA 5 350 502 460 12 121 390 256 3 209 477 410 I ----320 504 5 925 1177 1075 12 222 1177 591 3 510 1560 1370 I ----2251E Cl 5 0.2 15 6.0 12 0.8 25 11 '7 3 0.0 90 9.0 I ----30 F 4 .4 .5 .5 II 0.1 0.5 0.4 3 0.3 0.6 0.5 0 ------ II 4 0.06 0.99 0.19 12 0.0 0.99 0.13 2 0.04 0.27 0.16 I ----0.29 p 3 0.01 0.02 0.01 12 0.01 0.09 0.04 2 0.06 0.07 0.07 0 ------ NOT£: Measurements expressed in m«J/l. Durfor and Becker 1964) and usually slightly saline (Robinove et al. 19S8). Judging by TDS and dissolved constituent concentrations, water quality was better in O'Fallon Creek than in its tributary streams, and improved towards the down- stream reaches as a result of the 41 percent to 46 percent reductions in TDS-SC levels. Due to similarities in chemical composition, the water-use restrictions in the O'Fallon Creek drainage would be essentially the same as those noted in the Little Powder River and Mizpah Creek, and for the same reasons. This would pre- clude the use of the water as a surface water public supply due to the high TDS, sulfate, and hardness levels of the stream. Also, various agricultural uses and the aquatic biota could also be affected. Such restrictions, of course, would be greatest in the tributary streams and in the upper reaches of O'Fallon Creek as a result of the greater salinities and dissolved constituent concentra- tions. The streams in the 0' Fallon Creek drainage were obviously non-eutrophic; nitrogen and phosphorus concentrations were well below the reference levels. High TSS-turbidity levels were occasionally obtained in conjunction with run- off events; this was most noticeable in the lower reach of O'Fallon Creek. How- ever, the median concentrations of these constituents were not particularly high, and they were not significantly higher than those in other prairie streams. Turbidities occasionally may be too high for municipal use without extensive treatment for dissolved and suspended solids, but the median TSS-turbidity lev- els of the streams suggest a fair fishery. The O'Fallon Creek drainage does not appear to be affected by marked muni- cipal-organic pollution at present, as its BODs concentrations were not particu- larly high. BODs values and fecal coliform concentrations were generally simi- lar to the ranges obtained from Beauvais Creek and other small prairie streams. The TOC concentration of a single sample from lower O'Fallon Creek (table 122) also suggested no organic inputs entering the streams. Like most of the small creeksin eastern Montana, O'Fallon Creek and its tributaries have been classified as B-D3 streams by the State of Montana. With the exception of a few runoff samples, fecal counts from these waters were gen- erally within the coliform standards prescribed for this class of stream (table 8). In addition, the high maximum temperatures from the creeks were in accord with the B-D3 designation, as were the grab sample DO concentrations. Values of pH were also typically within the maximum-minimum, B-D3 criteria, although high pH values were occasionally obtained, and one reading from upper O'Fallon Creek exceeded the maximum standard. For the most part, however, temperature, pH, TSS-turbidity, DO, BODs, and fecal coliforms did not suggest significant water quality problems in the O'Fallon drainage. Nitrogen, phosphorus, fluoride, chloride, potassium, and most of the trace elements monitored from O'Fallon and Sandstone creeks (table 122) were not de- tected in levels high enough to detract from the streams' quality. The TR con- centrations of As, B, Cd, Cr, Cu, Pb, U, and Zn were consistently below the associated reference criteria. Of the metals, only the presence of iron and manganese suggested problems, as median TR levels exceeded the criteria for public supply-drinking water and aquatic life. However, the magnitude of the 2S5 N "' "' TABLE 122. Sunlllilry of trace elerr.cnt and miscellaneous constituent concentrations measured in the O'fc!.llon Creek drainaQe and in sc1..tll tributarie!l to the YcllO~IStone River below F"c!.llon, r-~ontana. As B Cd Cr Cu Fe 119 1·\n Pb TOC v Zn Cabin, Cedar, Hay. and Scvcnmi le cree~.s Upper 0' Fallon Lower O'Fallon Sandstone Creek betv.·cen Fallon Creek ncar (Sillily Creek near fallon near Plevna Glendive II I-I in 11ax ~ed II Min /·lax Mcd II Min ~ja:.. l·lcd II ~lin ~lh 2 '.001 <. 01 0::.01 3 <.001 < .01 <.001 2 <. 01 <.01 ., '01 2 <.DOl 0.00& I ----0.32 8 0.10 0. 30 0.15 1 -- -- 0.67 1 -- -- 3 <.001 <:,01 <.001 11 '.001 < .01 <.OOlb 3 <.001 -:.01 <.001 3 '.001 ..:.01 1 -- --<.01 1 ---- 3 <.01 0.01 < .01 11 -.:.01 0.04 <.01 3 <.01 0.01 -:.01 3 <.01 0.03 3 0. 31 1.1 0.49 11 0.02 17.2 0.95 3 0. 70 1.9 1.2 ) 0.42 1.9 1 ----<.001 2 0.08 0.11 0.095 10 0.03' 0. 77 0.05 2 0.20 0.26 0.23 3 0.1 0.17 1 ----<.01 2 ·:.01 0.01 --1 ----0.02 1 ---- 1 ----9 I -- -- 0.13 1 ----0. 14 1 ---- 3 ..::.01 0.02 ·:.01 11 <.01 0.09 0.01 3 ..:.01 0.02 0.02 3 .. 01 0.02 r:OTE: f~casurcmcnts arc expressed in mg/1; all metals arc total ret:over,,hlc ml'tJls. a Also .. 002 w,Js obtained. bAlsa, .007 was obtained. and ~led -- 0. 49 '. 001 .· .01 '.01 1.4 0.15 <.01 0. 35 0.01 Glendive Creek Fo> (reek ot Glendive flCilf Sidney II ~1 iII I·IJ~ ~led II Min f·\.JX. 2 0.00-1 0.01 0.007 3 '.001 '.01 2 -: 001 • .. 01 <-01 3 '.001 .,_01 I --.. <.01 1 ---- 2 0.01 0 03 0.02 3 -:.ol •, .Ill 2 1.2 1.7 I . 45 3 0.27 0. 32 1 ----0.06 2 0.0·1 0.06 2 ' .01 -:.01 -:.01 2 .. 01 ' '01 2 ., 01 0.02 --3 '.01 '.01 l~ed .· .o1• -:.001 -c..Ol · .. 01 0. 30 0. 0~) .. 01 .. 01 potential Fe-Mn problem, and that of mercury, cannot be definitely assessed be- cause dissolved concentration data is unavailable. In conclusion, the salinity-related factors--TDS-SC, hardness, sodium, and sulfate--appear to be the major ·factors detracting from the water quality in the O'Fallon Creek drainage. TRIBUTARY STREAMS In addition to O'Fallon Creek, numerous other small tributaries join the Yellowstone River below the confluence of the Powder River (USDI 1968). Except for a few collections completed by the state WQB on seven of the larger tribu- taries, very little water quality information is now available on these streams. The data were too sparse for a season-or flow-based classification; to increase the data base for the statistical summaries, the streams were combined geograph- ically wherever possible (major parameters are summarized in table 123). Trace element data are presented in table 122. Most Yellowstone tributaries in the lower drainage, like the mainstem, have been classified as B=D 3 streams; only Fox Creek is classified as B-D2. These tributaries generally have lower water quality than those in the mainstem; sam- ples from some streams in the lower basin had the lowest water quality in the entire Yellowstone region. For example, samples from Lonetree, Hay, Cedar, and Cabin creeks had TDS concentrations in excess of 8000 mg/1 and specific conduc- tance levels greater than 9000 vmhos/cm. The small Fox Creek tributary near Sidney, however, had high water quality. Fox Creek is largely perennial, and it had a sodium bicarbonate water. It also had low suspended and dissolved solids concentrations, low SC levels and SAR values, and cool temperatures. Fox Creek supports a small viable trout fishery (Karp et al. 1975), which is unique for eastern Montana and in accord with its B-D2 classification (Montana DHES, undated). The remaining small streams draining the region below the O'Fallon Creek subbasin are intermittent in nature and have the sodium sulfate water-character- istic of lowland streams. The TDS, SC, and SAR values were high and more typi- cal of prairie streams than those in Fox Creek. Suspended sediment concentra- tions and turbidities were low except in Glendive Creek, where they were quite high. This would preclude the use of Glendive Creek for public supply and as a fishery. Saline seep degradation of agricultural lands is becoming a prevalent pro- blem in many areas of Montana, including the northern counties of the lower Yellowstone drainage (Kaiser et al. 1975). This can affect the surface water quality in other streams in such saline seep regions. Surface runoff and ground- water return from afflicted areas could contribute to the high TDS-SC levels observed in some streams in the lower Yellowstone area--Hay Creek in Dawson County, Cabin Creek in Prairie and Fallon counties, Cedar Creek in Dawson and Wibaux counties, and Lonetree Creek in Richland County. All five of these counties have recognized saline seep acreages (Kaiser et al. 1975). The high nitrate-N concentrations shown in some of the samples from the region (table 123) 257 N U'l 00 TABLE 123. Sur11nary of the physicc11 parameters measured in small tributaries to the Yellowstone River below Fallon, Montana. Cabin, Cedar. Hay. and Sevenmile Crc~ks between Fallon and Glendive Glendive Creek at Glendive Fox Creek near Sidney lonetree Creek at Sidney N Min Max fled II Min M•x Mod N Min Max Med II Min Ma. Med Flow 7 0.0 1. OE 0.01 3 1.2 4.5 2.7 3 1.8 4.1 4.0 1 ----0.0 lemp 6 4.0 26.5 17.4 2 14.1 15.5 14.8 2 8.0 11.5 9.8 0 ------ pll 7 7.90 8.60 8.30 3 8.20 9.20 B.BO 3 B. 10 B.40 8.30 1 -- -- 7.80 sc 7 9BO 17,500 3670 3 1134 2264 2200 3 1137 1185 1163 1 -- -- 9125 TDS 7 953 15,302 2899 3 1257 1B95 1877 3 1004 1127 10B7 1 ----9127 Turb 1 ----30 2 44 8900 --1 ----1 0 ------ TSS 3 12 121 24 3 26 66,000 972 2 5 B.S 6.B 0 ------ DO 2 10.9 11.0 11.0 3 6.9 11.1 9.8 2 9.8 10.8 10.3 0 ------ BOD 0 ------2 1.2 3.3 2.3 2 3.6 5.6 4.6 0 -- -- -- FC 2 2 24 7 125 2 0 17,000 --2 640 >1000 --0 ---- -- Ca 7 20 495 71 3 9.6 88 13.9 3 63 77 76 1 ----184 fly 7 14 677 69 3 4.4 S.B 5.8 3 61 74 67 1 ----939 TH 7 108 4025 460 3 42 244 58 3 434 495 439 1 -- -- 4328 Na 7 212 3550 730 3 280 555 536 3 107 145 118 1 ----1225 K 2 11 15 13 2 4.0 9.5 6.8 2 5.2 6.5 5.9 0 ------ SAR 7 7. 1 26.0 13.4 3 7.8 37.3 30.5 3 2.2 3.0 2.3 1 ----8.1 HC0 3 7 151 527 293 3 441 800 767 3 379 578 428 1 ----122 TA 7 124 466 240 3 361 794 707 3 319 474 351 1 ----100 504 7 265 8400 1698 3 402 505 438 3 275 412 317 1 -- -- 6656 C1 7 0.0 1893 30 3 0.5 30 1.0 3 1.0 10 7.7 0 -- ---- F 3 -0. 2 0.6 0.4 2 0.9 0.9 0.9 3 0.3 0.8 0.4 0 ------ II 5 0.04 2.01 0.38 3 0.06 0.19 0.15 3 0.0 0.68 0.07 0 ------ p 4 0.01 0.22 0.06 3 0.02 0.06 0.03 3 <.01 0.04 0.02 0 ------ UOTE: Measurements expressed in ntg/l. ~ ---------- I I were also symptomatic of saline seep inputs to the waters, but they were not at levels that would affect surface water public supply (table 9) and livestock watering (tables 10-14}. The waters in these creeks were extremely hard except in some of the Glen- dive Creek samples, and slightly saline. The saline seep-affected streams had samples moderate to high in salinity (Robinove et al. 1958}. These waters would have a very high salinity hazard for irrigation and a high-to-very high sodium hazard (Fox Creek would have a high salinity hazard and a low sodium hazard) (USOA 1954). The chemical compositions of the waters varied considerably. Calcium and magnesium levels were usually fairly equal, although the Lonetree Creek sample had noticeably high magnesium concentrations; this may reduce its value as a source of water for stock. Glendive Creek had low calcium-magnesium concentra- tions and hardness levels, and Lonetree Creek had low bicarbonate concentrations. Chloride concentrations were particularly high in a few of the samples collected between Fallon and Glendive, further restricting the water's use for public sup- ply, irrigation, and livestock watering. For the most part, however, chloride, fluoride, potassium, and magnesium were minor constituents and did not suggest water quality problems. Sodium and sulfate were the dominant ions in the sam- ples. High sodium (SAR), sulfate, TDS-SC, and hardness levels would restrict many water uses, and such restrictions would be much greater in the streams with mod- erate-to-high salinity. In fact, waters with extremely high TDS-SC levels might be classified as unuseable even for livestock (Seghetti 1951). The major water- use restrictions for most of these streams can be briefly summarized as follows: 1) For use as surface water public supply, all streams had high TDS, sulfate (table 9), and hardness levels, and Glendive Creek had high turbidities. 2) For irrigation, Fox Creek had Class II waters, and other streams had Class Ill waters due to high sulfate and TDS-SC levels or high SAR and chloride values (tables 15 and 16). 3} For the aquatic biota (not in Fox Creek), major effects were evident with TDS-SC levels commonly in excess of 1350 mg/1 and 2000 ~mhos/em, and in the high TSS levels in Glendive Creek. 4) For the aquatic biota in Box Creek, some mild_ salinity effects were evident, as TDS concentrations were greater than 660 mg/1 and SC levels were greater than 1000 vmhos/cm. 5) For livestock watering, sulfate levels were high and sometimes TDS levels were high, except in Glendive and Fox creeks. Apart from salinity-related factors (and TSS-turbidity in Glendive Creek), most of the remaining major parameters did not suggest water quality degradation or water-use restrictions. BOD~ concentrations were not at levels high enough to indicate that organic pollut1on reaches the streams, and pH levels (with the exception of one sample) and DO concentrations were within the state standards for a B-D3 stream (table 8}. Stream temperatures also suggested B-D3 waters 259 (B-D2 waters in Fox Creek). Fecal coliform concentrations were high in the stream samples, and they were in excess of state criteria in several instances. However, with only six analyses for fecals available, additional collections would be necessary in order to fully assess the problem. Because of high sal- inity levels, these waters are unsuitable for public supply anyway except in Fox Creek. 260 1 YELLOWSTONE RIVER MAINSTEM TDS CONCENTRATIONS The Yellowstone River in Montana shows an obvious downstream change in water quality from its entrance to the state near Corwin Springs (from Yellow- stone National Park) to its exit into North Dakota near Fairview, Montana. Such downstream changes in water quality are conunon in ·.many streams, and are best seen in the Yellowstone by the increase in TDS concentrations towards the river's mouth. Figure 3 shows the median TDS concentrations for various sites on the river having adequate post-1966 USGS and state WQB records. Data in figure 3 were grouped by month to correspond to the seasons of the year, a high-flow·period (May to July), warm-and cold-weather low-flow periods, and the March-Apri 1 spring season. · As indicated in fi_gure 3, downstream increases in TDS occurred ttrrough all seasons of the year along the Yellowstone River. At all ·sites, lowest con- centrations occurred during the late spring/early summer runoff period. How- ever, the greatest increase in TDS between Corwin Springs and Sidney was noted during this high-flow season with a factor increase of 3.6 during May-July, and between 2.85 and 3.15 over the remainder of the year. The greatest increase in TDS occurred through the Billings-to-Miles City segment, which includes the con- fluence of the Bighorn River. This increase was observed during all seasons. Negligible alterations were recorded from Corwin Springs to Livingston, where small tributaries with excellent water quality join the mainstem. Moderate in- creases in TDS were recorded-for the Livingston-to-Billings reach (includin9 the confluence of the Clarks Fork River) and in the reach below Miles City (in- cluding the confluences of the Tongue and Powder rivers). Differences in TDS levels between seasons were greatest at sites on the lower reach of the river. Much higher concentrations of TDS were observed in the March-April and November-February periods than in the late spring/early sum- mer; intermediate concentrations were observed during the August-October season. In the upper river, seasonal differences in TDS were much less noticeable, al- though the high TDS:low TDS seasonal ratios were similar throughout the mainstem. Maximum changes in median TDS at sites on the Yellowstone River above Custer occurred between the high-flow period and the cold-weather low-flow season, and ranged from factors of 2.0 to 2.2. Seasonal changes in TDS at sites on the river below Custer ranged from factors of 1.8 to 2.0 and occurred between the high- flow period and the March-April early spring season. Seasonal TDS changes oc- curred at a factor of 1.6 in the river at Custer. Consequently, it may be con- cluded that the effect of the Bighorn River on the quality of the Yellowstone River was greatest during the early spring season. CHANGES IN CHEMISTRY Downstream changes in the Yellowstone River's water quality are also evi- dent through alterations in the stream's chemistry (table 124). Near Yellowstone 261 700 600 500 ~ 400 ..... .,. ..s <J) 0 1- 300 200 100 0 - » Q) c ..., en -~ » <J) ~ -:::;; u U) March-., Q) ~ ....... ~ ., ....... ..... .... ..... -I .... ...., I - I December- January-I February I ······· ... ~ ... ... ., ... . . . --········ U) ::> .... ····· August-u ····· .. .... September- :;;. October j/ c ~ a; iii . ~ ., . -::> . ...... :~ 0 ......... -· c ...J /.:" I -· <J) 1/ v, .............. .-·-· May- c ..... i ....... ·-June- "i : i July ~ /. 0 u 1:' .' -' .. / I ~--~-----· I _.: / ; ......... , ...... ······ .......... / --~ ~--· -· --· -· -· ~-----·- I I I 600 500 400 300 200 100 River Miles 900 800 700 600 500 400 300 200 Kilometers Figure 3. Median TDS concentrations at various sites on the Yellowstone River during four seasons of the year. 21i2 100 I 0 0 N 0'1 w -.... -----~------------------~ ----.. TABLE 124. Ratios of median calcium to sodium concentrations and median bicarbonate to sulfate concentrations at various sites on the Yellowstone River through four seasons of the year. August-October November-February r~a rch -Apri 1 May-July Ca:Na HC03:S04 Ca:Na HC03:S04 Ca:Na HC03:S04 Ca:Na HC03:S04 Corwin Springs 0.79 2. 17 0.75 1.98 0.83 --1.00 5.08 Livingston 1.19 3.76 1.20 3.14 1.10 3.06 1.40 5.25 Billings 1.42 2.38 1.59 2.01 1.48 1.99 1. 73 3.83 Custer 1.13 1. 51 1. 41 1.63 1.56 2.20 1.60 2. 72 Myers 1.07 1.22 1.10 0.98 1.00 0.87 1.19 1.35 Forsyth 0.92 1.10 1.13 1.03 0.97 0.88 1.14 1. 31 Miles City 0.96 1.09 1.00 0.96 0.98 0.88 1.27 1. 31 Fallon 0.93 0.98 0.96 0.93 0.78 0. 76 0.93 1 . 03 Sidney 0.90 1.03 0.89 0.95 0.79 0.85 0.95 1.26 National Park the river has a definite sodium-bicarbonate water during most of the year. However, tributaries to the Yellowstone above Billings typically have a calcium-bicarbonate composition, and this is reflected in the chemistry of the mainstem which gradually becomes calcium-bicarbonate from Corwin Springs to Billings. With river inputs below Billings, the water then tends to become progressively more sodium-sulfate because Ca:Na and HC0 3 :so 4 ratios decline to Custer. This, in turn, reflects tributary inputs to the ma1nstem because the tributary streams below Billings tend to have sodium-sulfate compositions. This alteration in the Yellowstone chemistry becomes very noticeable below the con- fluence of the Bighorn River, with its large volume of flow. The Yellowstone River tends to retain its calcium-bicarbonate composition at high-flow periods in the lower river from May to July due to the influence of the upstream cal- cium-bicarbonate tributary streams which have their peak flows then. The sodium- sulfate streams below Billings tend to have peak flows earlier in the year, and this is reflected in the low Ca:Na and HCO~:S04 ratios obtained during the March- April season at some locations. However, 1n the extreme lower river below Fallon, the Yellowstone River is mainly a sodium-sulfate stream. CHANGES IN WATER QUALITY Although there is a general deterioration in water quality and an alter- ation in chemistry downstream from Corwin Springs', the water quality in the upper Yellowstone River above Billings appears to be quite good, ·and suitable for all potential uses. This quality degradation is primarily due to increases in stream salinity. There is no evidence of marked pollution inputs to the stream. None of the concentrations of common constituents exceed recommended levels for human con- sumption and use, for stock water, or for irrigation. Fluoride concentrations were high near Corwin Springs due to the ·Yellowstone Park drainage, but· rapidly becomes diluted downstream in Montana. Dissolved oxygen concentrations are usually near saturation, and BOD levels do not indicate organic ·pollution. Most of the dissolved metalS do not appear to be in toxic concentrations. Possible exceptions are arsenic, apparently deri~d from Yellowstone Park, and mercury, which had grab sample concentrations occasionally in excess. of water use criteria. ·The critical· nutrients in the upper river are not generally at·levels character- istic of eutrophy, although the Yellowstone comes close to this condition in the segment near Custer. Temperatures in the Yellowstone River above Billings are generally comparable to those of a cold-water fishery. Of the water quality parameters, the fecal coliforms and possibly the phenols occur at concentrations that could indicate pollution problems. Concentrations of these two pollutants occur in the river near Billings, which has a number of industrial and waste- water discharges. Although the water quality in the lower river remains generally good, it shows a degradation due to increasing salinities which continues in the river as it flows from Billings to its confluence with the Missouri River in North Dakota; this is most obvious below the confluence of the Bighorn River (figure 3). A few specific parameters reach potential problem levels. Temperatures in the river below Billings are typical of a warm-water fishery and of a cold-water/warm-water transition zone between Big Timber and Bighorn. 264 , I I Dissolved oxygen levels remain very close to saturation but occur in lower con- centrations than levels observed upstream. BOD levels indicate no organic pol- lution, and fecal coliform concentrations do not indicate water quality problems. Dissolved metals usually do not approach toxic levels, but iron, manganese, and mercury have dissolved concentrations occasionally in excess of 1~ater use cri- teria. There is no evidence that the waters become eutrophic in the segment of the stream below Billings. The lower river's water therefore appears to be suitable for most beneficial uses. Drinking water may be the only exception. In the extreme lower segment of the river below Miles City, median TDS concen- trations and sulfate levels exceed recommended criteria for drinking water (500 mg/1 and 250 mg/1) from November to April, the seasonal low-flow period (figure 3). As illustrated in figure 4. turbidity and high levels of TSS may cause water quality problems below Miles City. A definite increase in TSS occurs downstream through all sites during the high-flow period with concentrations in the river exceeding 100 mg/1 below Laurel. At periods of low flow, however, TSS concentrations are typically less than BO mg/1 above Miles City. A marked increase in TSS occurs below this point through all seasons, and median TSS concentrations exceed 100 mg/1 through most of the year below Fallon ~elow the confluence of the Powder River). Such high TSS levels in the lower river de- grade its quality and could restrict certain beneficial water uses, such as a particular fishery or a source of public supply. In general, the water quality in the Yellowstone River is best at upstream sites and at high-flow periods, although the increase in TSS during this period detracts from its value. There is a general degradation in the river's quality downstream to Sidney, and TDS, sulfate, and TSS levels appear to be the main reasons. However, there is no evidence of extensive pollution inputs through most of the river's length. Water quality is generally good above Miles City and suitable for most uses. Below Miles City, sediment, TDS, and sulfate levels may restrict some water uses because· of the lower water quality through this segment. Nonpoint tributary inputs of inferior quality are the major contributors to downstream degradation of mainstem waters. ASSOCIATED DRAINAGES TDS CONCENTRATIONS TDS concentrations were found to be variable among the tributary streams of the Yellowstone Basin. High values were obtained in some cases and a wide range of SC levels was measured, varying from 250 to 17,500 ~mhos/em, depending on the stream and season of collection. TDS concentrations were generally greater in the primary, secondary, and tertiary tributary streams than at their points of juncture with the mainstem of the Yellowstone River. For the most part, TDS concentrations and SC levels increased downstream in these tributaries, and they were usually higher in the smaller streams of any particular subbasin. 265 ' "" .s (/) (/) I- 700- 600 - 500- 400 - 300 - Q; / ~ I u I / / .I / / / / / I / ""' .. c: "C (/) / May-I June-/ July / I / / I .i ; March-I April 1 /./ I / .· ~ I I g' I I . 200 - g _ I :"August- Ill I 1 1 :" September ~ I 1 / October 100 0 - 600 .~ (/) c: :t ~ 0 u ~ 3 .' / "" / I ~ .-/ ~~ ....... .-"" .· .. ,·' ~~~~ , I ,... . ..,· .," ', ...---...,..-------· November- ..,.~ ..-"' .,..... .-· December- :~--~~~---············· .. ····· 0-.. ···················· .... t~~~~~r; 500 900 800 700 I 400 600 300 River Miles 500 400 Kilometers I 200 300 200 I 100 100 Figure 4. Median TSS concentrations at various sites on the Yellowstone River during four seasons of the year. 266 l 0 0 I TOS concentrations in the streams of the study area were high and exceeded the recommended public water supply and drinking water standards in many cases.· The waters in many of the smaller streams and in the Powder River were usually slightly saline. Concentrations were consistently highest in the smaller streams such as Armells, Little Porcupine, Reservation, Otter, and Pumpkin creeks which have their headwaters directly in the basin. Values greater than 1000 mg/1 were typical. In some instances, TOS concentrations exceeded the threshold concentrations for stock water. Rosebud Creek and most of the larger streams had TOS concentrations typi- cally ranging between 500 and 1000 mg/1, although the Powder River had TOS con- centrations greater than 1000 mg/1. Of the other large streams, the Yellowstone and the Little Bighorn rivers had the lowest TDS concentrations in the basin. They were generally followed in order by the Bighorn River, the Tongue River and Pryor Creek, tributaries of the Little Bighorn and Bighorn rivers, and Rosebud Creek and the Powder River drainage. SALINITY Water quality in the Yellowstone Basin, judging by salinity levels, gener- ally declined in an eastward and downstream direction. Quality was generally inversely related to the size of the stream; that is, the smaller streams typi- cally had lesser water quality. Numerous exceptions, however, became evident. Some prairie streams, such as Sarpy Creek, actually showed downstream improve- ments in water quality. Also, the west-flowing Bighorn River, one of the larger streams in the Yellowstone Basin, had comparatively poor water quality, and the smaller east-flowing Fox Creek had comparatively good water quality. PH VALUES Values of pH in the various streams of the basin typically ranged between 7.8 and 8.5 units. In some cases, field readings were above or below these values. Values greater than 9.0 were obtained in a few of the smaller streams, but readings outside the recommended limits in tables 8-14 were rare. With few exceptions, pH values were well within the range recommended by the Committee· on Water Quality Criteria for aquatic systems (USEPA 1973). TEMPERATURE Stream temperatures in the basin generally varied from near 0 C in the win- ter to between 20 C and 29 C during the summer. This range and the warm summer· temperatures are typical of warm-water habitats in the Northern Great Plains .. An extreme temperature of 28.5 C was noted in the Powder River; high tempera- tures were more common in the smaller streams than in the Yellowstone River. In general, warm-weather water temperatures are in accord with the B-02 and B-03 designations applied to the tributary streams in the Yellowstone Basin be- low Laurel (Montana DHES, undated). The only inappropriate classification, in terms of temperature, may be Pryor Creek, with its B-01 designation. 2~7 DISSOLVED OXYGEN Dissolved oxygen (DO) is a critical water quality parameter related more to-biological and ecological factors than to human use. However, low DO con- tent in surface waters may indicate that it is organically polluted and there- fore unfit for human consumption. Groundwaters are often naturally devoid of oxygen; waters lacking oxygen generally have a "flat" taste, especially after boiling. From a biological point of view, game fish require DO concentrations of at least S ppm to reproduce, and they generally die if DO falls below 3 ppm (Salvato 1gS8). Montana criteria for oxygen in B-D 1 , B-D2, and B-D3 class streams are listed in table 8. With few exceptions, DO concentrations within the streams of the basin were at or near saturation levels during the period of sampling. DO levels ranged from about 6.0 to 13.S mg/1; the higher values were obtained during the winter, with water temperatures approaching o.ooc. As a result, DO values in the basin were typically greater than the minimum Montana requirements for salmonid propagation. The few exceptions were in the smaller streams, such as Sarpy Creek. ORGANIC POLLUTION Consistently high DO values in the streams of the study area indicate a general absence of major organic pollution in the basin. This is confirmed by data from the numerous BODs determinations, typically less than 6 mg/1 in most of the stream samples, but ranging up to about ll.S mg/1. Even the higher val- ues are not particularly high considering those taken from sewage outfalls. In a well-operated and functional lagoon system, values were generally between 40 and 80 mg/1, but approached 140 mg/1, and, in some instances, exceeded 200 mg/1 in poorly managed or nonfunctional systems. Yegen Ditch in Billings is an examp 1 e of an organically polluted flowing stream with BODs 1 eve 1 s ·between 20 and 2S mg/1 during some periods. Here, a BODs level of ll.S mg/1 is not indi- cative of a gross organic pollution. The general absence of municipal pollution in the middle Yellowstone River Basin is indicated by the bacteriological data. Fecal coliform counts varied widely at any given site between sampling dates and between streams. This data demonstrated a positive correlation with flow. Fecal counts were usually much lower than the permissible criteria listed in table 9, but often were higher than that level deemed desirable by the National Technical Advisory Board (NTAC 1968) for public supply. Because fecal counts were only occasionally greater than the standards established by the State of Montana forB class waters, they would not suggest water quality problems or indicate that extensive municipal inputs enter the Yellowstone tributaries. CHEMICAL COMPOSITION The larger streams varied considerably in their chemical compositions, but the smaller prairie creeks were usually sodium sulfate in character. Magnesium was an abundant cation in almost all of the tributaries and small streams; it often exceeded calcium on a weight and/or equivalence basis, suggesting dolomitic 268 J ' ' formations in the secondary cation. the waters in the basin. Generally, however, calcium was the major primary or As a result of the high calcium and magnesium concentrations, Yellowstone Basin were usually extremely hard. With a few exceptions, fluorides in the surface waters were below the upper limits for drinking water, and should therefore not prevent stock or human use. Chlorides, like potassium, were at negligible levels, and bicarbonate-carbonate and sulfate were the dominant anions. The major exceptions were in Sunday Creek and the Powder River, where sulfate exceeded the recommended criteria for human use in many cases; in some of the smaller streams, both of the dominant anions exceeded the threshold or limiting concentrations for livestock. Like sulfate, sodium was a common ion in all waters of the basin and was the dominant cation in many streams, but it exceeded threshold values for live- stock in only a few samples. A review of the SAR data in the samples. taken also indicates that waters from most of the larger streams of the Yellowstone River Basin--the Yellowstone, Little Bighorn, Bighorn, and Tongue rivers, and Rosebud Creek--are safe for irrigation. These data also indicate that most of the smal- ler streams (Tullock, Pryor, and Fly creeks, and the Little Powder River) of the basin and the Powder River could have sodium hazards for irrigation. Standards have been established (table 9) for nitrate in municipal supplies according to infant toxicities. None of the samples collected from the streams in the Yellowstone Basin exceeded or approached this limit. Phosphate standards for public supply and drinking water have not yet been established by the EPA or the U.S. Public Health Service. However, phosphate and nitrate even at such low concentrations remain critical parameters because they play critical roles in the development of toxic or nuisance algae and macrophyte blooms in surface waters, which influence human use. Data on nitrogen and phosphorus from the Yellowstone Basin indicate that none of the streams are obviously eutrophic, and that most are nitrogen-limited. Locations most likely to develop eutrophic conditions were the Yellowstone River near Custer and Sidney, the Bighorn River near Hardin, the Powder River, and various small streams in the extreme eastern portion of the basin. TURBIDITIES, TSS, AND FLOW Turbidity, TSS, and flow were found to be positively related. TSS values showed wide fluctuations between dates and streams. For example, in the Yellow- stone River TSS ranged from 8.8 to 992 mg/1 on different dates at Forsyth in correlation with flows of 7400 to 33,800 cfs. Similar wide fluctuations were evident in the smaller streams: Starved-to-Death Creek. 6.5-220 mg/1 and 0.01- 0.9 cfs; Pumpkin Creek, 13.0-1016 mg/1 and 0.6-42.7 cfs; and Moon Creek, 4.5- 482 mg/1 and 0.2-1.3 cfs. Rosebud Creek, Pryor Creek and the Powder River were unusual to have consistently high TSS values through the lower reaches regard- less of flow. Pryor Creek also had extremely high TSS values in some of its samples (values of 1720 and 3436 mg/1). Consequently, extremely high TSS con- centrations were also obtained in some of the streams of the lower basin; values exceeding 1000 mg/1 were found in the Yellowstone and Powder rivers and in Sunday and Glendive creeks. Extreme values of 62,800 mg/1 were obtained in the Powder River and 66,000 mg/1 in Glendive Creek. In the Yellowstone, TSS values 269 of 2600 and 9450 mg/1 were obtained. Such high TSS concentrations obviously degrade the quality of these streams, most noticeably in the Powder River. Turbidities varied greatly within and between the streams of the lower Ycllol"lstone Basin. Such fluctuations were apparently related to flow, judging from data from the Yellowstone River in which values varied from 6 JTU at 9300 cfs to 220 JTU at 35,100 cfs. During an extended rain in Sunday Creek, turbi- dities varied from 4 JTU at 0.6 cfs to 210 JTU at 75 cfs. Although turbidities less than 30 JTU were measured in almost all of the streams at appropriate sea- sons, values in the Little Powder and Powder rivers were consistently greater than 30 JTU. Fox Creek had turbidities consistently less than 10 JTU, possibly accounting for its value as a minor trout fishery. WATER QUALITY DEGRADATION It may be concluded that because of high TDS and TSS concentrations in some of the streams of the Yellowstone River Basin, the water quality in many of the tributaries and associated waters are poor, with a variety of water-use restric- tions. The main problems contributed by TDS concentrations are bicarbonate and sulfate as anions and sodium as a cation; TSS levels are particularly detrimental to water quality at high-flow periods. · Concentrations of iron, manganese, and mercury may detract somewhat from water quality, but the remaining water quality parameters--dissolved oxygen, BOD, bacterial counts, pH, temperature, and nutrients (nitrate and phosphate)-- apparently do not. WATER QUALITY INDEX The water quality index (WQI) of samples provides a valuable tool for as- sessing the relative water quality status of a stream. The WQI, developed by the National Sanitation Foundation (Brown et al. 1970, Brown et al. 1973, Brown and McClelland 1974, McClelland 1974), has been applied to several of the sam- ples collected by the state WQB from the Yellowstone Basin in Montana from the mainstem and from numerous of the tributary streams (table 125). Waters in the upper Yellowstone above Laurel can be considered good on the basis of their WQI's (Brown and McClelland 1974), but they show a general down- stream decline in quality from Laurel to the North Dakota border. Brown and McClelland (1974) have developed the following relationships for the WQI: 0-25, very bad; 26-50, bad; 51-70, medium; 71-90, good; and 91-100, excellent. In these terms, the Laurel-to-Bighorn reach of the Yellowstone has water quality ranging from medium (51-70) to good (71-90); according to the mean WQI, a good quality is most typical .. The same analysis applies to the Bighorn-to-Miles City reach, although a few samples with a bad rating (26-50) were also obtained there. In the extreme lower reach, a medium-minus classification (with a mean WQI equal to 55) would best describe its type of water. The quality of waters in the Yellowstone Basin as a whole ranged from bad- to-good according to the WQI values. On the basis of average WQI"'s, the waters 270 ' 1 , ~ TABLE 125. Water quality index (WQI) of samples collected by the state WQB from various streams, stream reaches, and drainage areas in the Yellowstone Basin. Number of Points of Collection Samples Range of WQI Mean WQI Yellowstone River above Laurel 10 72.6-B5.1 79.4 Yellowstone, Laurel to Bighorn 11 53.5-81.1 68.8 Yellowstone, Bighorn to Miles City 17 48.9-81.1 66.1 Yellowstone, Miles City to mouth 10 50.3~69.7 54.9 Pryor drainage 7 49.7-75.4 62.8 Arrow and Fly creeks 4 62.7-70.8 67.3 Little Bighorn River tributaries 13 60.4-84.3 72.2 Little Bighorn River 9 64.4-81.9 74.3 Bighorn-Yellowtail tributaries 6 76.7-91.3 85.7 lull ock Creek 7 61.7-75.9 68.9 Other Bighorn tributaries 7 57.3-75.7 65.4 Bighorn River 10 58.3-76.3 70.2 Sarpy and Armells creeks 20 44.5-83.2 69.7 Other small streams 14 54.3-83.6 73.4 Rosebud Creek tributaries 7 55.7-80.0 71.0 . Upper Rosebud Creek 6 55.1-78.3 67.7 Middle Rosebud Creek 6 57.7-75.0 66.2 Lower Rosebud Creek 7 46.6-72.0 58.3 Tongue River tributaries 12 62.3-81.6 72.9 Pumpkin Creek 7 44.5-89.0 74.0 Upper Tongue River 3 77.4-78.5 77.8 Middle Tongue River 6 70.6-81.1 77.3 Tongue River-Miles City 6 55.0-80.2 . 69.8 Sunday Creek 4 56.9-82.9 62.9 Little Powder River 5 54.4-74.1 63.2 Mizpah Creek drainage 7 56.0-77.6 67.8 Upper Powder River 6 50.5-75.9 61.7 Lower Powder River 6 50.8-64.6 58.4 0' Fallon Creek 8 49.3-79.5 65.8 Basin Averages 57.2-78.8 68.8· Totals 241 Extremes 44.5-91.3 54.9-85.7 ranged from medium-to-good, with a medium-plus designation (a mean WQI equal to 69) most representative of the entire basin. The best water quality was obtained from the Yellowtail-Bighorn tributaries and from the upper Yellowstone River above Laurel. The lesser water quality was obtained from lower Rosebud Creek, from lower Powder River, and from the extreme lower reach of the Yellowstone River below Miles City. The tributaries to the Yellowstone and the associated streams typically had medium-to-good water quality. The water quality in Rosebud Creek, the Tongue River, and the Powder River also declined to some extent downstream. In most cases, the tributary streams had slightly lesser water qualities than the mainstem, but the Yellowstone River had a lower quality than most of its tributaries at their points of confluence, 271 according to the WQI. On the basis of a nationwide comparison made possible through the use of a standardized WQI, the waters of the Yellowstone Basin, including those in many of the small prairie tributaries and the Powder River, apparently have a fairly good quality according to the WQI. However, the description of a good water quality in terms of the variables considered in the WQI is obviously not appropriate to water uses of the Yellow- stone Basin as outlined throughout this report. The WQI designation of Sarpy and Armells creeks as having "almost" a ~ood water quality (.i.e., a mean WQI of 6g.7 compared with the standard of 71) and a better quality than the Yellow- stone seems ludicrous, but this is apparently true on a national scale of com- parison. The development of a more specific WQI that relates directly to the Yellowstone drainage and its particular water uses and water quality problems may resolve such discrepancies. POTENTIAL HATER QUALITY PROBLEMS IN RELATION TO WATER USE The most obvious water-use restrictions throughout the Yellowstone Basin would be directed towards using the streams for surface water public supply and for drinking water. This is due primarily to the high TDS, sulfate, and hard- ness levels (table 9). Turbidity and the occasionally high fecal coliform, iron, manganese, and mercury concentrations could also restrict use for surface water · public supply and for drinking water during some or all seasons in several of the streams. The unsuitability of water for public supply was found in almost all of the smaller streams in the primary study area of the basin and in many of the larger streams, including the lower reach of the Yellowstone River below Miles City. The waters in the Yellowstone Basin, for the most part, should provide a good quality of water for stock animals (Seghetti 1951), and it should be excel- lent for all types of livestock (USEPA 1973). In some cases, however, particul- arly in the smaller streams, sulfate concentrations exceeded the limiting or threshold levels of livestock, which could affect the animals adversely. In a very few instances, other dissolved constituents, e.g., magnesium and bicarbon- ate, exceeded reference levels. Most commonly, TDS concentrations and sulfate exceeded the theshold-limiting levels; these waters were considered fair for livestock and not applicable to poultry. Highly saline waters termed poor and unfit were collected from a few of the smaller streams. Their use would be even more restricted. In general, though, the waters in the Yellowstone Basin appear to be highly suitable for livestock. Restrictions to aquatic life in the Yellowstone Basin were also caused pri- marily by TDS concentrations. Temperature, of course, naturally regulates types of fisheries in the streams of the basins by providing warm-water and cold-water salmonid fisheries. The Yellowstone River gradates from a cold-water stream above Big Timber near the mountains to a warm-water stream below Bighorn in the lowlands (Berg 1977, Peterman 1977). There is no evidence that man's activities through point-source inputs disrupt or alter these natural changes to any great extent, except possibly through the industrialized Billings area (Karp et al. 1976b). Nonpoint influences would be much more likely in the Yellowstone Basin, but these would be difficult to recognize and quantify. 272 ~ 1 ' 1 On the whole, dissolved oxygen, pH, temperature levels, and fecal coliform concentrations were within the criteria and standards established by the State of Montana (table 8) for stream designations applied to the waters of the Yellowstone drainage (Montana DHES, undated). The effects of salinity and sus- pended solids on the aquatic biota are expected to be much greater than the influences of most of the other water quality variables. However, iron and mercury had dissolved concentrations occasionally (and, in one case, the phenols) in excess of the reference criteria for aquatic life in some streams and reaches, including the Yellowstone River (table 19). The effects of salinity on the aquatic biota would probably vary among the streams of the Yellowstone Basin, corresponding to the highly variable salinity levels of the region. In many instances, no effects or only mild influences are anticipated, with TDS and SC levels less than 670 mg/1 and 1000 ~mhos/em. Ellis (1944) claims that these salinity levels are acceptable in western alkaline streams supporting a viable and mixed fish fauna. This is probably true in most of the large streams in the study area. In many of the smaller lowland creeks, more adverse effects might be ex- pected with TDS and SC levels greater than the values specified by Ellis (1944). In a few instances, salinity would be more detrimental to the freshwater biota, with TDS and SC levels greater than 1350 mg/1 and 2000 ~mhos/em. Although salin- ity in many of the basin's streams was not at adequate levels to exert a marked influence over the aquatic biota, high suspended solids concentrations in their waters could act in this manner. This could result in a degradation of the stream's fishery potential (USEPA 1973, European Inland Fisheries Advisory Com- mission 1965, Bishop 1975, Peters 1962} and a reduction in its productivity (Klarich 1976) regardless of the low TDS levels. Many of the larger streams in the Yellowstone drainage would be affected in this way, including Pryor Creek, the Little Bighorn River, the lower Bighorn, Tongue, and Yellowstone rivers, and Rosebud Creek. In some cases, especially in the Powder River and in certain of the smaller streams, the dissolved and suspended solids would act together to degrade the aquatic environment. Salinity was at adequate levels to reduce the value of some of the waters in the Yellowstone Basin for irrigation (Allison 1964, USEPA 1973, California WRCB 1974, USDA 1954, USEPA 1976). But this influence and its associated re- strictions would vary considerably throughout the basin because of the variable TDS and SC levels among the streams. Some of the streams in the ·drainage would have an excellent source of water for application to all crop and forage species with minimal risk, and other streams would be unsuitable for a variety of plant types, particularly the salinity-sensitive species (table 17). Overall, restrictions on water use are due to the high TDS-SC levels and their high sulfate concentrations rather than from high boron, chloride, or SAR (sodium) levels. The concentrations of the various trace elements (tables 15 and 16) generally do not reduce the value of a particular water for irrigation. The Powder River drainage and a few of the smaller streams have a high sodium hazard for irrigation because of the water's high sodium concentrations and SAR values, and its high salinity hazard. But in most instances, salinity is the major deterrant to irrigation, and the better water quality for irrigation is usually found in the larger streams which have lower salinity levels. 273 "' ..... ... TABLE 126. Summary of water quality in the Yellowstone River Basin of Montana for surface water public supply and drinking water. Parameter Group Salinity and common ions Restricting Parametersa pH {R) (NTAC permissible criteria) pH {R) (EPA recommen- dation) Chloride (R) Chloride (0) Fluoride (R) Total hardnessb Total hardnessb Total hardnessb TDS ( R) TDS {0) TDS (F) TDS (C) ( R) (F) (C) Affected Streams Most streams in the Yellowstone Basin Upper Sarpy, upper O'Fallon, and Glendive creeks Small Yellowstone tributaries below the Bighorn River, and the upper Powder River Sunday Creek Small Yellowstone tributaries between the Bighorn and Powder rivers; Little Powder River Yellowstone-Big Timber to Laurel Yellowstone-Laurel to Custer; Sunday and Glendive creeks Yellowstone-Bighorn to mouth; remaining streams in the Yellowstone Basin Upper Little Bighorn River; Bighorn-Yellowtail tributaries Sage Creek; Yellowstone-Myers to Miles City Lower Little Bighorn River; Yellowstone below Miles City; Tongue River Pryor drainage; Arrow and Fly creeks; Little Bighorn tributaries; Bighorn River; remaining Bighorn tribu- taries; Sarpy and Armells creeks; Sunday Creek; small Yellowstone tributaries below Laurel; Rosebud drain- age; Tongue tributaries; Powder and O'Fallon drainages N ...... U1 Table 126 (continued) Parameter Group Salinity and common ions (continued) Physical factors Toxic-Harmful substances and health hazards Restricting Parameters a Sulfate (R) Sulfate (O) Sulfate (F) Sulfate (C) Turbidity-TSS (R) Turbidity-TSS (0) Turbidity-TSS (F) Turbidity-TSS (C) Fecal coliforms (R) Affected Streams Bighorn-Yellowtail tributaries; Yellowstone-Myers to Miles City Little Bighorn River and tributaries; Yellowstone- below Miles City; Rosebud tributaries; Tongue River Pryor drainage; Arrow Creek; upper Bighorn River; Sunday Creek Fly Creek; lower Bighorn River; other Bighorn tribu- taries (except Sage Creek); Sarpy and Armells creeks; small Yellowstone tributaries below Laurel; remaining Rosebud Creek (except the upper Rosebud); Tongue tri- butaries; Powder and O'Fallon drainages Yellowstone-Laurel; Little Bighorn tributaries; Big- horn-Yellowtail tributaries; upper Tongue River; Hanging Woman Creek; possibly Otter Creek Yellowstone-Billings to Intake; Arrow Creek; Little Bighorn River; lower Bighorn River; Bighorn tributar- ies (Soap, Rotten Grass, and Tullock creeks); Sarpy and Armells creeks; small Yellowstone tributaries below Bighorn; upper Rosebud Creek; small Tongue tributaries; Pumpkin Creek; Little Powder River; Mizpah Creek; O'Fallon drainage Beauvais Creek; Sunday Creek; middle and lower Rose- bud Creek; lower Tongue River (except below the dam); upper Powder River; lower Yellowstone River-Sidney Pryor drainage; lower Powder River Lower Bighorn River; Yellowstone-Myers to Miels City; Sunday Creek; upper Rosebud Creek; upper and lower Tongue (not the middle Tongue below the dam); Pumpkin Creek; Powder River; Mizpah Creek; O'Fallon Creek, small Yellowstone tributaries below the Powder River and between Laurel and Custer N ..... 0\ Table 126 (continued) Parameter Group Toxic-Harmful substances (continued) Restricting Parametersa Fecal coliforms (0) Fecal coliforms (F) Arsenic (R) U.S. Public Health Service standard Arsenic (0) U.S. Public Health Service standard Arsenic (F) U.S. Public Health Service standard Arsenic (R) U.S. Public Health Service rejection and NTAC criteria Selenium (R?) Selenium (R) Cadmium (R?) Iron (R) Iron (R?) Iron (0) Iron (0?) Affected Streams Yellowstone-Billings and Custer; Pryor drainage; Yellowstone-Terry to mouth Yellowstone River-Huntley Yellowstone-Huntley to Miles City; middle Rosebud Creek Yellowstone-Laurel to Billings Yellowstone above Laurel Yellowstone-Laurel to Billings Beauvais Creek Yellowstone-Laurel to Bil]ings Sarpy and Armells drainages Yellowstone River; Fly Creek; lower Bighorn River; Sarpy and Armells drainages; Hanging Woman and Otter creeks; upper Powder River Other Yellowstone tributaries between Laurel and Custer and below the Powder River; Bighorn-Yellowtail tributaries; Pumpkin Creek; lower Powder River; Miz- pah Creek; O'Fallon drainage Upper Tongue River Most Bighorn tributaries (Soap, Rotten Grass, Sage, and Tullock creeks); small Yellowstone tributaries between the Bighorn and Powder rivers; Sunday Creek "' ..... ..... Table 126 (continued) Parameter Group Toxic-Harmful substances (continued) Restricting Parametersa I ron (F) Manganese (R) Manganese (R?) Manganese (0) Manganese (O?) Manganese (F) Manganese (F?) Mercury (R) Mercury (R?) Mercury (0) Mercury ( 0?) Ni trite-Nitrate Affected Streams Beauvais Creek; little Powder River Yellowstone River; little Bighorn River; upper Big- horn River; upper Tongue River and below the dam; small Tongue tributaries; upper Powder River Little Bighorn tributaries, lower Bighorn River, Bighorn-Yellowtail tributaries, lower Tongue River (except, possibly, Tongue-Miles City); lower Powder River; Mizpah Creek; O'Fallon drainage; Yellowstone tributaries below the Powder River Sarpy Creek; east and west fork Armells Creek; small Yellowstone tributaries between the Bighorn and Powder rivers Bighorn tributaries (Soap, Rotten Grass, Sage, and Tullock creeks); Sunday Creek Fly Creek; Beauvais Creek; lower Armells Creek, little Powder River Other Yellowstone tributaries between Laurel and Custer Yellowstone-Myers to Miles City; small Yellowstone tributaries between the Bighorn and Powder rivers; upper Tongue River and Tongue-Miles City; lower Powder River; little Powder River Yellowstone-Huntley to Custer; Bighorn River; Beauvais Creek; Armells Creek Yellowstone River above Huntley and the lower Yellow~ stone near Sidney; upper Powder River Upper Sarpy Creek (possibly not lower Sarpy) No streams in the Yellowstone Basin ~ Table 126 (continued) Parameter Group Toxic-Harmful substances (continued) Restricting Ammonia (R) Ammonia (0) Ammonia (C) Phenols (F) Parameters a Affected Streams Yellowstone-Laurel to Custer; upper Bighorn River; upper Powder River East fork Armells Creek Upper Sarpy Creek Yellowstone-Laurel to Custerc NOTE: Streams not listed were not affected by the restricting parameters. Also, non-affecting parameters are usually omitted. aRestricting water quality parameters listed are those which rarely (R), occasionally (0), frequently (F), consistently (C), or never (N) exceeded the associated reference criteria for a water use or feature. bwaters were classified as hard-very hard. ~ cThis stream reach was the only one with available phenol data. N ..... 1.0 TABLE 127. Summary of water quality in the Yellowstone River Basin of Montana for livestock. Parameter Group Salinity and common ions Restricting Parametersa TDS (threshold)b (R) TDS (threshold)b (0) TDS.(threshold)b (F) TDS (threshold)b (C) TDS (limiting)c (R) TDS (limiting)c (0) TDS (limiting)c (F) TDS (limiting)c (C) pH (threshold) (NTAC permissible criteria pH (limiting) (EPA recommendation) Bicarbonate (R) Affected Streams Small Yellowstone tributaries between the Bighorn and Powder rivers; small Tongue tributaries Small Yellowstone tributaries between Laurel and Custer; lower Sarpy Creek; Hanging Woman, Otter, and lower Pumpkin creeks; Little Powder River; O'Fallon drainage Upper Sarpy Creek Armells drainage; upper Pumpkin Creek; Mizpah drainage; small Yellowstone tributaries below the Powder River (except Fox and Glendive creeks) East fork Armells Creek; small Tongue tributaries; Mizpah Creek Upper Sarpy Creek; west fork Arme.lls Creek; small Yellowstone tributaries below the Powder River (ex- cept Fox and Glendive creeks) · Upper Pumpkin Creek Mizpah Creek tributaries Most streams in the Yellowstone Basin Upper Sarpy, upper O'Fallon, and Glendive creeks Fly Creek; minor little Bighorn tributaries; small Yellowstone tributaries below Bighorn; Sunday Creek; lower Rosebud Creek; little Powder River N ()) C> Table 127 (continued} Parameter Group Salinity &Qd common ions (cont1nued) Restricting Parametersa Bicarbonate (0) Bicarbonate (F) Bicarbonate (C) Fluoride (threshold) (R) Fluoride (threshold) (0) Fluoride (R) (EPA recommendation) Magnesium (threshold} ( R) Magnesium (threshold) (0} Magnesium (threshold) (F) Magnesium (limiting) (R) Sodium ( thresho 1 d) ( R) Sodium (threshold} (F) Sodium (threshold) (C) Sodium (limiting) (R) Sulfate (threshold) (R) Sulfate (threshold) (0) Affected Streams Tullock and lower Pumpkin creeks; O'Fallon drainage Lower Sarpy Creek; Armells drainage; Rosebud and small Tongue tributaries; Mizpah drainage Upper Sarpy, Hanging Woman, Otter, and upper Pumpkin creeks Yellowstone above Huntley; Beauvais Creek; small Yellowstone tributaries between the Bighorn and Powder rivers; Sunday and lower Rosebud creeks; little Powder River Upper Sarpy Creek; small Tongue tributaries Small Yellowstone tributaries between the Bighorn and Powder rivers; little Powder River Small Tongue tributaries Upper Sarpy and upper Armells creeks Upper Pumpkin Creek Cedar Creek Upper Sarpy Creek; Armells drainage; Lonetree Creek Upper Pumpkin Creek Mizpah Creek tributaries Cedar and Second Hay creeks Arrow, Sunday, and lower Rosebud creeks Rotten Grass Creek ~ -Table 127 (continued) Parameter Group Salinity and common ions (continued) Toxic-Harmful substances and health hazards Restricting Parametersa Sulfate (threshold) (F) Sulfate (threshold) (C) Sulfate (limiting) (R) Sulfate (limiting) (0) Sulfate (limiting) (F) Sulfate (limiting) (C) Chloride (threshold) (R) Nitrite-Nitrate Vanadium (R?) Affected Streams Lower Tullock Creek; small Tongue tributaries Small Yellowstone tributaries-Laurel to mouth; Fly, Beauvais, and Sarpy creeks; Armells drainage; major Tongue tributaries; Powder and O'Fallon drainages Beauvais and lower Tullock creeks; Powder River Fly Creek; small Yellowstone tributaries below Bighorn; small Tongue tributaries; little Powder River Lower Sarpy, Hanging Woman, and lower Pumpkin creeks Small Yellowstone tributaries between Laurel and Custer; upper Sarpy Creek; Armells drainage; Otter and upper Pumpkin creek; Mizpah and O'Fallon drainages Cedar Creek No streams in the Yellowstone Basin Lower Sarpy and Armells creeks; small Yellowstone tributaries below Bighorn NOTES: Streams not listed were not affected by the restricting parameters. Also, non-affecting parameters are usually omitted. No apparent problems were noted for stock from trace elements and metals in the basin. aRestricting water quality parameters listed are those which rarely (R), occasionally (O), frequently (F), consistently (C), or never (N) exceeded the associated reference criteria for a water use or feature. bFair-to-poor waters for stock. cGenerally unfit waters for stock. "' ()) "' TABLE 128. Summary of water quality in the Yellowstone River Basin of Montana for irrigation. Parameter Group Salinity and common ions - Restricting Parametersa High salinity hazardb High salinity hazardb High salinity hazardb High salinity hazardb Very high salinity hazardC (0) Very high salinity hazardc (F) Very high salinity hazardC (C) Medium-high sodium hazardd (R) Medium-high sodium hazardd (0) Medium-high sodium hazardd (F) (R) (O) (F) (C) Affected Streams Yellowstone-Myers to Forsyth; upper Little Bighorn River Lower little Bigh~rn River; Yellowstone-Miles City to Intake Upper Tongue River and below dam; lower Yellowstone River near Sidney Pryor drainage; Arrow and Fly creeks; little Bighorn tributaries; Bighorn River; Bighorn tributaries (Beauvais, Soap, Rotten Grass, and Tullock creeks); Sunday and Rosebud creeks; Rosebud tributaries; lower Tongue River; small Tongue tributaries; lower Pumpkin Creek; Powder River; Fox Creek Fly and lower Tullock creeks; Powder River Small Yellowstone tributaries (except Fox Creek); small Tongue tributaries; lower Pumpkin Creek Sarpy and Armells drainages; Hanging Woman, Otter, and upper Pumpkin creeks; little Powder River; Mizpah and O'Fallon drainages Upper Sarpy and east fork Armells creeks; small Tongue tributaries (except Deer Creek) Upper Powder River Small Yellowstone tributaries-Laurel to Custer; Fly and Tullock creeks; Deer Creek; lower Powder River N (I) w - Table 128 (continued) Parameter Group Salinity and common ions (continued) Restricting Parameters Medium-high sodium hazardd (C) High-very high hazarde ( R) sodium High-very high sodium hazarde (O) High-very high hazarde (F) sodium High-very high sodium hazarde (C) Potential chloride problems (R) Potential chloride problems (O) Minor suvate problems (R) Minor sulfate problemsf (0) Minor sulfate problemsf (F) Affected Streams Lower Sarpy and west fork Armells creeks; lower Armells Creek; small Yellowstone tributaries be- tween the Bighorn and Powder rivers; Sunday, Hanging Woman, and Otter creeks; little Powder River; Mizpah and O'Fallon drainages Lower Armells and Sunday creeks Mizpah Creek Pumpkin Creek; O'Fallon drainage; small Yellowstone tributaries below the Powder River (except Fox Creek) Mizpah tributaries Small Yellowstone tributaries between the Bighorn and Powder rivers; Powder River; Cedar Creek Sunday Creek Sunday Creek Beauvais and lower Tullock creeks; small Tongue tri- butaries (except·Deer Creek); upper Powder River; 0' Fall on Creek Small Yellowstone tributaries-Laurel to the Powder River; Fly Creek; lower Pumpkin Creek; lower Powder River; Mizpah Creek Table 128 (continued) Parameter Group Salinity and common ions (continued) Toxic-Harmful substances and health hazards Restricting Parametersa Minor sulfate problemsf (C) Major sulfate problems9 (R) Major sulfate problems9 (0) Major sulfate problemsg (F) Major sulfate problemsg (C) Fluoride (threshold) (R) Fluoride (threshold) (0) Boron Cadmium (R?) Manganese ( R) Manganese (R?) Molybdenum ( R) Affected Streams Sarpy, Hanging Woman, and Otter creeks; little Powder River Otter Creek Lower Sarpy, Hanging Woman, and lower Pumpkin creeks; little Powder River; Mizpah Creek Upper Sarpy and Deer creeks; O'Fallon tributaries Armells drainage; upper Pumpkin Creek; Mizpah tribu- taries; small Yellowstone tributaries below the Powder River (except Fox and Glendive creeks) Yellowstone above Huntley; Beauvais Creek; small Yellowstone tributaries between the Bighorn and Powder rivers; Sunday and lower Rosebud creeks; little Powder River Upper Sarpy Creek; small Tongue tributaries Does not appear to be an affecting factor in the Yellowstone Basin Sarpy and Armells drainages Yellowstone above Livingston; Beavais Creek; Armells drainage; upper Powder River Soap, Rotten Grass, and Tullock creeks Beauvais Creek "' co (J1 Table 128 (continued) Parameter Group Physical factors Restricting Parametersa Molybdenum (0) Selenium (0) Vanadium (R?) Flow Tssh ( R) Tssh (R,O) Tssh (OJ Tssh (F) Tssh (c) Affected Streams Upper Bighorn River Yellowstone-Laurel to Billings Sarpy and Armells creeks; small Yellowstone tribu- taries below the Bighorn River Many of the smaller streams are restricted to flood irrigation during high-flow runoff periods Yellowstone-Laurel to Custer; upper Pryor and Sarpy creeks; Armells drainage; Yellowstone tributaries beb1een the Bighorn and Powder rivers; Mizpah and O'Fallon drainages Yellowstone-Myers to Miles City; Tongue River near Miles City Little Bighorn and lower Bighorn rivers; Rotten Grass, Soap, lower Tullock, Sunday, lower Rosebud, and Pump- kin creeks; Yellowstone-Terry to Intake Lower Pryor Creek; Beauvais Creek; upper Powder River; little Powder River; lower Yellowstone River near Sidney; Glendive Creek Lower Powder River NOTE: Streams not listed were not affected by the restricting parameters. Also, non-affecting parameters are usually omitted. aRestricting water quality parameters listed are those which rarely (R), occasionally (0), frequently (F), consistently (C), or never (N) exceeded the associated reference criteria for a water use or feature. N CD en Table 128 (continued) bBased on TDS concentrations and SC levels; waters are most typically Class II. cBased on TDS concentrations and SC levels; waters are most typically Class III. dBased on SAR values; waters are most typically Class II. eBased on SAR values; values are most typically Class III. fMost typical of Class II waters. gMos t typi ca 1 of Class II I waters. h There is an indirect effect on irrigation by silting ditches and the potentially reduced soil permeability; 300 mg/1 is used as a general guide. N CX> .... ----- TABLE 129. Summary of water quality in the Yellowstone River Basin of Montana for aquatic biota. Parameter Group Salinity and common ions Physical factors- TSS (Turbidity)C Restricting Parametersa Potential effectsb (R) Potential effectsb (0) Potential effectsb (F) Potential effectsb (C) Detrimental effectsb ( R) Detrimenta 1 effectsb (0) Detrimental effectsb (F) Detrimenta 1 effectsb (C) pH (B-D 1 stream) (R) pH (B-D 2 , B-D 3 streams (R) Poor fishery (R) Affected Streams Little Bighorn and upper Tongue rivers; Yellowstone- Powder River to mouth Pryor and Arrow creeks; Bighorn River; upper Rosebud Creek; lower Tongue River Fly Creek; small Tongue tributaries; Fox Creek Beauvais, Soap, Rotten Grass, Tullock, Sunday, and lower Rosebud creeks; Rosebud tributaries; Pumpkin Creek; Powder River; lower O'Fallon Creek Beauvais Creek Fly Creek; small Tongue tributaries Lower Tullock and Pumpkin creeks; Powder River; lower O'Fallon Creek Small Yellowstone tributaries (except Fox Creek); Sarpy Creek; Armells drainage; Hanging Woman and Otter creeks; little Powder River; Mizpah drainage; upper O'Fallon Creek and tributaries Yellowstone River above Laurel; lower Pryor Creek Upper Sarpy and O'Fallon creeks; Glendive Creek Yellowstone-Custer to Miles City; little Bighorn River; Bighorn near Bighorn (mouth); Soap, Rotten Grass, and lower Tullock creeks; Tongue River near Miles City N co co Table 129 (continued} Parameter Group Physical factors- TSS (turbidity)C (continued) Physical factors- Temperatured Physical factors- Turbiditye - Restricting Parametersa Poor fishery (0) Poor fishery (F) Poor fishery (C) Very poor fishery Very poor fishery Very poor fishery ·Very poor fishery ( R) (0) (F) (C) B-0~ streams (definite pro lem) B-D streams (po~sible problem) B-D streams (po~sible problem) Turbidity effects ( R) Turbidity effects (O) Turbidity effects (F) Affected Streams Lower Pumpkin Creek; Yellowstone-Terry to Intake Beauvais, Sunday, and lower Rosebud creeks; little Powder River Lower Pryor Creek; Powder River; Yellowstone River near Sidney Yellowstone-Terry to Intake Beauvais and Sunday creeks; little Powder River; Yellowstone River near Sidney Upper Powder River Lower Pryor Creek; lower Powder River; Glendive Creek Lower Pryor Creek Lower little Bighorn and upper Tongue rivers Sunday and lower Mizpah creeks Yellowstone-Big Timber to Laurel; small Yellowstone tributaries-Laurel to Custer Yellowstone-Laurel to Miles City; Arrow and Fly creeks; upper little Bighorn River; Sage Creek; lower Sarpy and lower Armells creeks; upper Rosebud Creek; upper Tongue River (except the Tongue below dam}; small Tongue tributaries; Hanging Woman and lower Pumpkin creeks Lower little Bighorn, lower Bighorn, and lower Tongue rivers --~---~--------------'--L-------~----L---~-~----- N 00 <.0 Table 129 (continued) Parameter Group Physical factors- Turbiditye (continued) Eutrophic potentialf Restricting Parametersa Turbidity effects (C) B-0 3 streams (R) Critical levels (<3mg/l) (R) Phosphorus (R,O) Phosphorus (F) Phosphorus (C) Phosphorus (F) (EPA recommendation) Phosphorus (C) (EPA recommendation) Nitrogen (R,O) Affected Streams Pryor Creek; Pass and Owl creeks (little Bighorn tributaries); Beauvais, Soap, Rotten Grass, and Tullock creeks; Sunday Creek; lower Rosebud Creek; Powder and little Powder rivers; lower Mizpah and tributaries; Yellowstone-Terry to Sidney; O'Fallon drainage; Glendive Creek Lower Tullock, Sarpy, and east fork of Armells creeks; lower Rosebud and Otter creeks; upper Powder River Lower Sarpy Creek; upper Powder River Most of the streams in the Yellowstone Basin produced a few or occasional samples with phosphorus in excess of reference criteria and the EPA's reference levels. Yellowstone River near Laurel; Arrow and Sunday creeks; Yellowstone-Terry to Intake Yellowstone near Corwin Springs; Yellowstone-Huntley to Custer; Bighorn River near Hardin; Beauvais and Rotten Grass creeks; lower Rosebud Creek; upper Ton- gue River; Powder River; Yello~1stone near Sidney Yellowstone River near Huntley; Bighorn River near Hardin; Beauvais, Sunday, and lower Rosebud creeks; upper Tongue River Yellowstone near Custer; Powder River; Yellowstone near Sidney Most of the streams in the Yellowstone Basin produced a few or occasional samples with nitrogen in excess of reference criteria and the EPA's reference levels. TABLE 129 (continued) Parameter Group Eutrophic potentialf (continued) "' <0 0 Toxic-Harmful substances and health hazards ---- Restricting Parametersa Nitrogen (F) Nitrogen (C) Nitrogen (F,C) (EPA recommendation) Phosphorus and nitrogen (N,R) Phosphorus and nitrogen (0) Phosphorus and nitrogen (F) Phosphorus and nitrogen (C) Phosphorus and nitrogen (F,C) (EPA recommendation) Aluminum Silver Arsenic Affected Streams Yellowstone River near Custer; Bighorn River near Hardin; Sunday Creek; Powder River; Yellowstone- Terry to Intake and near Sidney Arrow Creek No streams in the Yellowstone Basin Most streams in the Yellowstone Basin were non- eutrophic Sunday Creek; Yellowstone-Terry to Intake Arrow Creek; Yellowstone near Custer; Bighorn near Hardin; Powder River; Yellowstone near Sidney No streams (possibly eutrophic) No streams (high probability of eutrophy) Yellowstone, Bighorn, and Tongue Rivers; Otter and Beauvais creeks all had a few samples in excess of reference criteria, but this probably does not suggest a hazard. TR concentrations were generally high but dissolved levels were typically low. Only a few analyses were made; some samples were in excess of minimal risk levels, but did not indicate a hazard No apparent problems, even in the upper Yellowstone "' <0 ...... Table 129 (continued) Parameter Group Toxic-Harmful substances (continued) Restricting Parametersa Copper (R) Copper (R?) Iron (R) Iron (R?) Iron (0) Iron (0?) Iron (C) Tota 1 mercury (grab sample) ( R) Tota 1 mercury (grab sample) (R?) Tota 1 mercury (grab sample) (0) Affected Streams Yellowstone River above Livingston; upper Bighorn River; Beauvais Creek; upper Yellowstone Small Yellowstone tributaries between Laurel and Custer; Tullock and Sunday creeks; Mizpah drainage Yellowstone above Custerg, upper Bighorn River; lower Bighorn Riverg; west fork Armells Creekg, lower Armells Creekg; Rosebud drainage; Tongue River near Miles City (except below dam to Brandenburg); small Tongue tributaries; Hanging Womang, Otterg, and Pumpking creeks; Powder Riverg; Yellowstone near Sidneyg. Small Yellowstone tributaries below Laurelg; Sage Creek Yellowstone River eear Miles Cityg; Sarpy Creekg; upper Tongue River Soapg, Rotten Grassg, and Tullockg creeks; Sunday Creekg; Mizpahg and O'Fallong drainages Beauvais Creekg; little Powder Riverg Bighorn River; Yellowstone River near Myers; upper Tongue and lower Tongue River below Birney; Hanging Woman, Otter, and Pumpkin creeks Little Bighorn River and tributaries; Tongue River below the dam Yellowstone above Huntleyh; Beauvais Creek; small Yellowstone tributaries between th~ Bighorn and Powder rivehs; lower Rosebud Creek ; small Tongue tributaries ; Yellowstone River-Terry to Intake; Yellowstone River near Sidneyh N <.0 N Table 129 (continued) Parameter Group Toxic-Harmful substances (continued) Restricting Parametersa Tota 1 mercury {grab sample) (F) Tota 1 mercury (grab sample) (C) Inadequate mercury data Manganese (distinct hazard) Manganese (slight hazard) (F) Manganese (slight hazard) (R?) Manganese (slight hazard) (0) Selenium (R) Zinc (very slight hazard) (R) Zinc (very slight hazard) (R?) Zinc (very slight hazard) (R,O) Affected Streams Yellowstone-Forsyth to Miles Cityh; lower Sarpy Creek; lower Armells Creekh; Powder Riverh Upper Sarpyh and Armellsh creeks; little Powder Ri verh Small Yellowstone tributaries; little Bighorn River and tributaries; upper Bighorn River and most tri- butaries; Sunday Creek; upper Rosebud Creek and tributaries; upper Tongue and below dam; Pumpkin Creek; Mizpah and O'Fallon drainages No streams in the Yellowstone Basin Yellowstone above Laurel; upper Bighorn River; Beauvais, Tullock, and Sarpy creeks; small Tongue tributaries; upper Powder and little Powder rivers; Yellowstone near Sidney Small Yellowstone tributaries between Laurel and Custer; Sunday Creek; Mizpah drainage Arme ll s Creek Yellowstone-Laurel to Billings; Beauvais Creek; upper Powder River Yellowstone River above Billings; Yellowstone River near Miles City; Armells Creek; Rosebud drainage; Yellowstone River near Sidney Soap, Rotten Grass, and Tullock creeks; Sarpy and Pumpkin creeks Tongue River - Table 129 (continued) Parameter Group Toxic-Harmful substances (continued) Restricting Parameters Zinc (very slight hazard) (O) Zinc (very slight hazard) (F) Zinc (very slight hazard) (C) Zinc (definite hazard) ( R) Fluoride (R) Cyanide (R) Phenols Ammonia (un-ionized); (R) Ammonia (un-ionized); (0) Ammonia (unionized); (C) - Affected Streams Yellowstone-Myers to Forsyth; small Tongue tribu- taries; Otter Creek; Yellowstone River-Terry to Intake Beauvais Creek; Powder River Bighorn River Small Yellowstone tributaries between the Bighorn and Powder rivers; little Powder River Small Yellowstone tributaries between the Bighorn and Powder rivers; little Powder River Yellowstone River-Laurel to Billings; upper Powder River Probably not at-levels high enough to affect the aquatic biota Yellowstone-Livingston to Laurel; upper Bighorn River; Yellowstone River near Miles City; upper Powder River Yellowstone-Laurel to Custer; east fork of Armells Creek Upper Sarpy Creek NOTE: Streams not listed were not affected by the restricting parameters. Also, non-affecting parameters are usually omitted. aRestricting water quality parameters listed are those which rarely (R), occasionally (0), frequently (F), consistently {C), or never (N) exceeded the associated reference criteria for a water use or feature. / Table 129 (continued) bBased on TDS concentrations and SC levels. cGenerally based on median seasonal suspended sediment concentrations. Samples where high suspended sediment levels were frequently and consistently obtained probably indicate major overall degradation of the fishery; samples where high suspended sediment levels were only rarely or occasionally obtained indicate runoff events with lesser effects on the fishery. din general, temperature ranges and maximum temperatures of the streams in the Yellowstone Basin were in accord with the B-D designations assigned by the State of Montana. eRetardation of primary production through reduced light penetration; generally based on a median turbidity of 25 JTU (from Klarich 1976). f . Arrow Creek, the Yellowstone River near Custer, the Bighorn River near Hardin, the Powder River, and the Yellowstone River near Sidney were the locations most likely to have eutrophic conditions, but none demonstrated a high probability of developing eutrophy. gPotentially hazardous iron levels to aquatic life occurred. hMedian mercury exceeded the average criteria. Detection levels of numerous analyses were inadequate to fully assess the potential mercury problems in many cases. 1Based on a pH value of 8.0; ammonia data are not available on many streams. - N ·.o U1 ----• --- TABLE 130. Summary of the potential for organic pollution in the Yellowstone River Basin of Montana. Parameter Group Oxygen status Restricting Parametersa Low percenta9e DO saturationb (R) Low percentage DO saturationb (0) Low percenta9e DO percentageb (F) High BOOse (R) High BOOSe (0) High BOOSe (F) High TOCd (R) High TOCd (0) High TOCd (F) High TOCd (F?) High TOCd (C) Affected Streams Yellowstone-Myers to Sidney; lower Tongue River; Powder River (a few extremely low readings of less than 40 percent were obtained in conjunction with high.TSS levels) Armells and Rosebud creeks; small Tongue tributaries; Hanging Woman and Otter creeks Sarpy and Mizpah creeks Tullock, lower Sarpy, and lower Armells creeks; small Yellowstone tributaries between the Bighorn and Powder rivers; Sunday and Pumpkin creeks Mizpah drainage and lower O'Fallon Creek Upper Sarpy Creek; little Powder River Yellowstone River above Livingston never had excessive TOC levels; Yellowstone-Livingston to Laurel; Yellow- stone-Laurel to Billings never had excessive TOC levels; Yellowstone-Huntley to Custer; Bighorn River; Yellowstone-Myers to Miles City Upper and middle Tongue River; Yellowstone-Terry to Sidney Tongue River near Miles City Little Powder River All Tongue tributaries; lower Powder River N •.!) "' Table 130 (continued) Parameter Group Oxygen status (continued) Restricting Parametersa Very hi~h TOG and COD levels {>40 mg/1 in at least one sample) Affected Streams Yellowstone River below Livingston; upper Sarpy Creek; small Tongue tributaries; lower Powder River NOTES: Streams not listed for a water quality parameter were not affected by the restricting parameters; also, non-affecting parameters are omitted. No COD data was available on Armells and Rosebud creeks and many other streams. aWater quality parameters listed are those that rarely (R), occasionally (0), frequently (F), consistently (C), or never (N) exceeded the associated reference criteria for a water use or feature. bBased on Beauvais Creek data. cA median value of 5 mg/1 and a maximum level of 10 mg/1 from Beauvais Creek were used as reference points, but even these values are not particularly notable. dValues of 10 mg/1 were used for TOC and 20 mg/1 for COD, surface water average, for general reference. These levels were not exceptional. In general, the Yellowstone Basin does not appear to be influenced by much organic pollution, including the reach near Laurel-Billings. The only exception may be in upper Sarpy Creek. · • ------ ---- TABLE 131. Summary of violations of state water quality standards in the Yellowstone River Basin of Montana. Parameter Group Salinity and common ions Physical factors- temperatureb Toxic-Harmful substances and health hazards Restricting Parametersa pH (B-0 1 stream) (R) pH (B-0 2 , B-0 3 streams ( R) B-0 streams (definite problem) B-0 streams (po§sible problem) B-D streams (po~sible problem) Fecal coliforms (grab sample} (R) Feca 1 coli forms (grab sample) (R?) Feca 1 co 1 i forms (grab sample) (0) Feca 1 co 1 iforms (grab sample) (0?) Affected Streams Yellowstone River above Laurel; lower Pryor Creek Upper Sarpy and O'Fallon creeks; Glendive Creek Lower Pryor Creek Lower little Bighorn and upper Tongue rivers Sunday and lower Mizpah creeks Yellowstone near Laurel; Owl and Pass creeks (little Bighorn tributaries); lower Armells Creek; small Yellowstone tributaries below Bighorn; all Tongue tributaries Fly Creek; upper Rosebud Creek and tributaries (the lower Rosebud never had excessive levels) Yellowstone-Custer to Forsyth; Pryor Creek drainage; most Bighorn tributaries and the little Bighorn River; upper Sarpy Creek; upper Tongue River (the middle Tongue never had excessive levels); lo~1er Tongue near Miles City; Powder and little Powder rivers; Yellowstone near Sidney; O'Fallon drainage Arrow Creek N <.0 co Table 131 (continued) Parameter Group Toxic-Harmful substances (continued) Restricting Parametersa Fecal col iforms (grab sample) (F) Feca 1 co 1 i forms (average) (R?) Feca 1 co 1 iforms (average) (0) Feca 1 co 1 i forms (average) (0?) Feca 1 Co 1 i forms (average) (F) Feca 1 coli forms (average) (C) Radiochemistry Oil and grease (R) Affected Streams Yellowstone-Billings to Huntley; Yellowstone near Miles City; Sunday Creek; Mizpah drainage; Yellow- stone-Terry to Intake Arrow and Fly creeks; Pass Creek; upper Rosebud Creek and tributaries (the lower Rosebud never had excessive levels) Yellowstone River near Custer; Pryor Creek drainage; Yellowstone-Myers. to Miles City; upper Tongue River (the remainder of the Tongue below the dam never had excessive levels); Powder River; Mizpah drainage Soap Creek (Bighorn tributary) Yellowstone River near Billings and from Terry to Intake; Sunday Creek Yellowstone River near Huntley The small amounts of radiochemical data available on the Yellowstone Basin indicate that these constituents should cause no· problems. Yellowstone-Livingston to Laurel (Yellowstone-Huntley to Custer never had excessive levels); upper Sarpy Creek NOTES: Streams not listed were not affected by the restricting parameters. Also, non-affecting parameters are usually omitted. In many cases, the Rand 0 .violations listed for fecal coliforms were associated primarily with runoff. aRestricting water quality parameters listed are those which rarely (R), occasionally (0), frequently (F), consistently (C), or never (N) exceeded the associated reference criteria for a water use or feature. bin general, temperature ranges and maximum temperatures of the streams in the Yellowstone Basin were in accord with the B-D designations assigned by the State of Montana. "' <D "' - TABLE 132. Summary of aesthetic quality in the Yellowstone River Basin of Montana. Parameter Group Physical factors Restricting Parametersa Color (slightly colored)b (R) Color (sli(htly colored)b N) Color (slightly colored)b (C) Color (highly colored)b (0) Color (highly colored)b (C) Turbidity (TSS) ( R) Turbidity-TSS (0) Affected Streams Yellowstone-Laurel to Billings; Bighorn River and Beauvais Creek; Yellowstone River near Miles City; Tongue River near Miles City; Yellowstone near Sidney No data is available on Yellowstone-Livingston to Laurel, Yellowstone-Custer to Forsyth, Tongue River above Miles City, Yellowstone-Terry to Intake Yellowstone-Corwin Springs to Livingston; Yellow- stone-Billings to Custer Upper Powder River; no data is available on the lower Powder and little Powder r-vers Upper Powder River Up~er Sarpy Creek; no data available on lower Sarpy Yellowstone-Laurel; little Bighorn tributaries; Big- horn-Yellowtail tributaries; upper Tongue River; Hanging Woman Creek; possibly Otter Creek Yellowstone-Billings to Intake; Arrow Creek; little Bighorn River; lower Bighorn River; Bighorn tribu- taries (Soap, Rotten Grass, and Tullock creeks); Sarpy and Armells creeks; small Yellowstone tribu- taries below Bighorn; upper Rosebud Creek; small Tongue tributaries; Pumpkin Creek; little Powder River; Mizpah Creek; O'Fallon drainage w 0 0 Table 132 (continued) Parameter Group Physical factors (continued) Eutrophic potentialc Restricting Parameters Turbidity-TSS (F) Turbidity-TSS (C) Phosphorus (R,O) Phosphorus (F) Phosphorus (C) Phosphorus (F) (EPA recommendation) Phosphorus (C) (EPA recommendation) Nitrogen (R,O) Nitrogen (F) Nitrogen (C) Nitrogen (F,C) (EPA recommendation) Affected Streams Beauvais Creek; Sunday Creek; middle and lower Rose- bud Creek; lower Tongue River (except below the dam); upper Powder River; lower Yellowstone River-Sidney Pryor drainage; 1 0\~er Powder River Most of the streams in the"Yellowstone Basin produced a few or occasional samples with phosphorus in excess of reference criteria and the EPA's reference levels. Yellowstone River near Laurel; Arrow and Sunday creeks; Yellowstone-Terry to Intake Yellowstone near Corwin Springs; Yellowstone-Huntley to Custer; Bighorn River near Hardin; Beauvais and Rotten Grass creeks; lower Rosebud Creek; upper Ton- gue River; Powder River; Yellowstone near Sidney Yellowstone River near Huntley; Bighorn River near Hardin; Beauvais, Sunday, and lower Rosebud creeks; upper Tongue River Yellowstone near Custer; Powder River; Yellowstone near Sidney Most of the streams in the Yellowstone Basin produced a few or occasional samples with nitrogen in excess of reference criteria and the EPA's reference levels. Yellowstone River near Custer;.Bighorn River near Hardin; Sunday Creek; Powder River; Yellowstone- Terry to Intake and near Sidney Arrow Creek No streams in the Yellowstone Basin - Table 132 (continued) Parameter Group Eutrophic potentialc (continued) w Toxic-Harmful substances => ..... and health hazards Restricting Parameters Phosphorus and nit regen ( N , R) Phosphorus and nitrogen (0) Phosphorus and nitrogen (F) Phosphorus and nitrogen (C) Phosphorus and nitrogen (F,C) (EPA reconunendation) Oil and grease ( R) Oil and grease (N) Phenols MBASd (detectable) (~) MBASd (detectable) ( R) MBASd (detectable) (F) MBASd (high levels) Affected Streams Most streams in the Yellowstone Basin were non- eutrophic Sunday Creek; Yellowstone-Terry to Intake Arrow Creek; Yellowstone near Custer; Bighorn near Hardin; Powder River; Yellowstone near Sidney No streams (possibly eutrophic) No streams (high probability of eutrophy) Yellowstone-Livingston to Laurel; upper Sarpy Creek Yellowstone-Huntley to Custer The small amount of data available on phenols indi- cate that this constituent is apparently not at adequate levels to taint fish flesh and degrade sports fisheries at present; however, this has been a problem in the Yellowstone River below Billings in past years Several locations on the Yellowstone River Upper Bighorn River (no data available on lower reach) Upper Powder River (no data available on lower reach) No streams with available data Table 132 (continued) NOTE: Streams not listed were not affected by the restricting parameters. Also, non-affecting parameters are usually omitted. aRestricting water quality parameters listed are those which rarely (R), occasionally (0), frequently (F), consistently (C), or never (N) exceeded the associated reference criteria for a water use or feature. bColor of ten units was used as a reference point. Color data was not available for many streams, such as the Little Bighorn River; Armells, Rosebud, and Mizpah creeks; and most small streams. CArrow Creek, the Yellowstone River near Custer, the Bighorn River near Hardin, the Powder River, and the Yellowstone River near Sidney were the locations most likely to have eutrophic conditions, but none demonstrated a high probability of developing eutrophy. dMBAS data indicate the occurrence of synthetic detergents. Concentrations higher than 0.5 mg/1 indicate the potential development of unsightly foaming in flowing waters. However, this does not appear likely in the Yellowstone Basin, which had MBAS levels generally less than 0.05 mg/1, but data are lacking for most streams in the drainage. w 0 w TABLE 133. Summary of miscellaneous constituents in the Yellowstone River Basin of Montana. Constituentsa Pesticides-herbicides Strontium Silica Fecal strepb (R) Fecal strepb (F) Affected Streams Available data indicate that pesticides-herbicides probably do not cause water quality problems in the Yellowstone Basin. These constituents were detected in only a small percentage of the samples analyzed and in small concentrations. This constituent does not appear to be at levels high enough to cause radiochemical water quality problems in the Yellowstone drainage. This constituent does not occur in concentrations high enough to degrade water quality in the Yellow- stone Basin. Lower Bighorn, lower Tongue, and lower Powder rivers; lower Yellowstone River near Sidney Beauvais Creek NOTE: Streams not listed were not affected by the constituents listed. aConstituents listed are those which rarely (R), occasionally (0), frequently (F), consistently (C), or never (N) exceeded the associated reference criteria for a water use or feature. bFecal strep data are available on only a few streams in the Yellowstone drainage; the state's fecal coliform criteria for grab samples serves as the reference point. As indicated, fecal strep concentrations were not particularly high and did not suggest municipal pollution; FC:FS ratios generally indicate animal rather than human wastes entering the streams. FC:FS values were typically less than one. The major exception was found in the lower segment of the Yellowstone River near Sidney, wh1ch was apparently affected by municipal inputs judging from its FC:FS ratio greater than two. Fecal strep data are not available on the Yellowstone River below Laurel-Billings, where municipal pollution is al~o ap- parently a problem. I PROJECTIONS OF FUTURE USE In order to adequately and uniformly assess the potential effects of water withdrawals on the many aspects of the present study, it was necessary to make projections of specific levels of future withdrawals. The methodol- ogy by which this was done is explained in report No. 1 in this series, in which also the three projected levels of development, low, intermediate, and high, are explained in more detail. Summarized in appendix A, these three future levels of development were formulated for energy, irrigation, and municipal water use. Annual water depletions associated with the future levels of development were included in the projections. These projected depletions, and the types of development projected, provide a basis for deter- mining the level of impact that would occur if these levels of development were carried through. POTENTIAL WATER QUALITY EFFECTS BY SUBREGION UPPER YELLOWSTONE SUBBASIN Total Dissolved Solids Fourteen years of records (1951-58, 1963-69) on the Yellowstone River at Billings were used to develop the regression equations given in table 134 which were the basis for the analyses. Three levels of development were projected for the Yellowstone River at Billings. In each, a negligible or zero salt input to the stream was assumed for one set of calculations under a 50th per- centile median flow and a 90th percentile low flow. Calculations were also made with salt pickups of one-half ton per acre per year and one ton per acre per year under the conditions of each projection and with each of the two associated flow levels. This approach provided 18 separate analyses of the Yellowstone River at Billings as summarized in table 135 (low level of develop- ment), table 136 (intermediate level of development), and table 137 (high level of development). Low Level of Development. Projected increases in TDS in the Yellowstone River at Billings under the low level of development generally would have neg- ligible effects on irrigation; this is true regardless of the flow assumption and even when a maximum salt pickup of one ton per acre per year is assumed in the calculations. In fact, the inclusion of salt pickup by irrigation return flows had only a small effect on increasing the TDS levels of the river under the low level of development. As indicated in figure 5, major increases in TDS are projected to occur during the late summer and fall. With median flows, significant increases in TDS concentrations were obtained only in August and September (12.3 percent to 14.3 percent), and increases of less than 7 percent were obtained during the rest of the year. For 90th percentile low flows, in- creases were greater through most of the year, ranging from a low of less than 1 percent in March to highs approaching 25 percent during the fall (figure 6). 3()5 ------------------------------------------·--· TABLE 134. Regression equations between TDS (in mg/1) and monthly discharge (Q) (in acre-feet) in the Yellowstone River at Billings, 1951-58 and 1963-69. Month Best Fit Equation Jan log TDS = 3.16424 -. 12912 log Q Feb log TDS = 3.54116 -.20614 log Q Mar TDS = 1527.71 -235.17461 log Q Apr log TDS = 4.24384 -.34054 log Q May TDS = 924.22705 -131.16983 log Q June log TDS = 2.57791 -.08230 log Q July TDS = 935.46143 -135.05623 log Q Aug log TDS = 4.27605 -.35261 log Q Sept TDS = 1622.26001 -251.31508 log Q Oct log TDS = 5.05812 -.48689 . log Q Nov TDS = 2255.61938 -368.94141 log Q Dec TDS = 2119.83569 -346.26465 log Q All months log TDS = 4.82194 -.44798 log Q aNot significant at 5 percent level. bSignificant at 1 percent level. r2 Significance .073 a .196 a .766 b .645· b .606 b .063 a . 827 b .850 b .868 b .834 b .806 b . 510 b .934 b However, such increases under low-flow conditions would appear to be of insuffi- cient magnitude to affect the use of the Yellowstone River at Billings for irri- gational or municipal purposes. Intermediate Level of Development. TDS increases under the intermediate level of development at 50th percentile values are projected to be very small over most of the year. Major effects are predicted to occur in August and September (increases of 16 percent to 19 percent over the historical). Concen- tration increases are greater through a large portion of the year under low- flow conditions. These range from less than 1 percent during the winter and spring to highs approaching 22 percent during the fall. However, TDS concentra- tions do not increase to a level that would preclude the use of Yellowstone River water for beneficial uses in the vicinity of Billings; this would be true under median flow and drought/low-flow conditions, even with a maximum salt pickup. 306 w 0 ..... • TABLE 135. TDS values in the Yellowstone River at Billings, assuming a low level of development without the Fish and Game reservation. 50th Percentile Values 90th.Percentile Values Simulated Simulated Historical TDS at Historical TDS at Q TDS Q Salt pickupa of: Q TDS Q Salt pickupa of: 0 ~ 1 0 ~ (a f) (mg/l) (a f) (mg/l) (mg/l) (mg/1) (a f) (mg/1) (a f) (mg/l) (mg/l) Oct 259,964 264 245,036 273 273 274 178,376 317 163,456 332 334 Nov 219,651 285 219,666 285 286 286 188,047 310 188,062 311 311 Dec 178,447 301 178,411 302 302 303 133,321 345 133,290 346 347 Jan 152,g97 312 153,036 313 313 314 100,573 330 100,470 331 331 Feb 159,627 294 159,451 295 295 295 120,732 312 120,568 312 312 March 210,571 276 210,452 276 277 277 143,958 315 143,850 315 316 April 245,835 256 241,904 258 258 258 171,383 289 167,308 292 293 May 755,249 153 697,674 158 159 159 398,290 190 340,719 200 200 June 1 ,617,805 117 1 ,545,894 117 118 118 1,137,038 120 1,065,127 121 122 July 906,166 131 804,278 138 139 139 481 ,261 168 379,376 183 184 Aug 322,491 216 230,954 243 245 247 211 ,401 250 119,876 307 310 Sept 247,691 267 184,038 300 301 302 172,160 306 108,507 358 360 fflnua 1 5,276,494 182 4,870,794 187 188 188 3,436,540 211 3,030,609 220 221 aSalt pickup given in tons per acre per year. 1 (mg/l) 335 312 347 332 313 316 293 201 122 185 314 362 221 TABLE 136. TDS values in the Yellowstone River at Billings, assuming an intermediate level of development without the Fish and Game reservation. 50th Percentile Values 90th Percentile Values Simulated Simulated Historical TDS at a Historical TDS at a Q TDS Q Salt pickup of: Q TDS Q Salt pickup 0 !:2 1 0 !:2 (a f) (mg/1) (a f) (mg/1) (mg/1) (mg/1) (a f) (mg/1) (a f) (mg/1) (mg/l) Oct 259,964 264 244,956 274 275 277 178.376 317 163,380 334 336 Nov 219,651 285 219,982 286 287 288 188,047 310 188,379 312 313 Dec 178,447 301 178,661 302 303 304 133,321 345 133,545 346 348 Jan 152,997 312 153,219 313 314 315 100,573. 330 100,663 331 332 Feb 159,627 294 159,567 295 295 296 120,732 312 120,690 310 313 March 210,571 276 210,636 277 277 278 143,958 315 144,040 316 317 Apri 1 245,835 256 241 ,574 258 259 260 171,383 289 166,985 293 294 May 755,249 153 691 ,032 159 160 ' 161 398,290 190 334 ,079 202 203 June 1,617,805 117 1,537,069 118 118 119 1 '137 ,038 120 1,056,308 122 123 July 906,166 131 787,143 140 141 142 481,261 168 362,245 187 189 Aug 322,491 216 217,809 249 253 257 211 ,401 250 106,737 319 327 Sept 247,691 267 178.382 303 306 309 172,160 306 102,850 364 368 Annua 1 5,276,494 182 4,820,030 189 189 191 3,436,540 211 2,979,901 222 223 aSalt pickup given in tons per acre per year. of: 1 (mg/1) 339 314 349 334 314 318 295 205 123 191 335 373 225 TABLE 137. TDS values in the Yellowstone River near Billings, assuming a high level of development without the Fish and Game reservation. 50th Percentile Values 90th Percentile Values Simulated Simulated Historical TDS at a Historical TDS at Q TDS Q Salt pickup of: Q TDS Q Salt pickupa of: 0 ~ 1 0 ~ 1 (a f) (mg/1) (a f) (mg/1) (mg/1) ( mg/1 ) (a f) (mg/1) (a f) (mg/1) (mg/1) (mg/1) Oct 259,964 264 244,866 274 277 279 178,376 317 163,295 335 339 342 Nov 219,651 285 220,263 286 288 289 188,047 310 188,660 312 314 316 Dec 178,447 301 178,882 302 304 306 133,321 345 133,769 347 349 351 Jan 152,997 312 153,367 313 315 316 100,573 330 100,820 332 334 336 Feb 159,627 294 159,657 295 296 297 120,732 312 120,787 313 314 315 March 210,571 276 210,786 277 278 279 143,958 315 144,195 316 318 319 April 245,835 256 241,219 258 260 261 171,383 289 166,637 294 295 297 May 755,249 153 684,165 160 161 162 398,290 190 327,214 204 206 209 June 1 ,617 ,805 117 1,528,209 118 119 119 1 '137 ,038 120 1,047,449 123 124 125 July 906,166 131 769,993 142 143 145 481 ,261 168 345,099 190 194 198 Aug 322,491 216 204.654 255 261 267 211 ,401 250 93,589 334 348 362 Sept 247,691 267 172,690 307 311 315 172,160 306 97 '157 371 378 385 Annual 5,276,494 182 4,768,751 190 191 192 3,436,540 211 2,928,671 223 226 228 aSalt pickup given in tons· per acre per year. :::: "' E "' 0 .... ~ :;: c 0 ,. .. "' 0 :;; > "" -:::: "' ~ "' 0 .... ~ :;: c 0 ,. .. "' ~ .. > "" 400 350 300 250 200 150 100 50 Level of Development HiQh HiQh Intermediate Historical Salt Pickup ( lons/ocre/year) I 0 0 NOTE: 5oth Percentile Values without F S G Reservation o;---,---,---,---r---r--or--.---.--~--~---r--~ Oct Nov Dec Jon Feb Mar. Apr May June July Aug Sept Figure 5. Average monthly TDS concentrations in the Yellow- stone River at Billings at 50th percentile values. 400 350 300 250 200 150 100 Level of Development HiQh High Intermediate Historical Salt Pickup (tons /acre/year) I 0 0 -·· .-·-· ... ··) I ,•'/ I. _/·., .. -" .. ' tr· If . ,, 11 i..~ iii if/ i/ l .I/ I~ NOTE: 901h Percentile Values without F 8 G Reservation 0 4---~--~--~---r---r---r---r---r---r--~--~--~ Oct Nov Dec Jan Feb Mar Apr May June July Auo Sept Figure 6. stone River at Average monthly TDS concentrations Billings at 90th percentile values. 310 in the Yellow- High Level of Development. Effects of the high level of development in increasing mean monthly TDS concentrations in the Yellowstone River at Billings are illustrated in figure 5 for median flows and in figure 6 for 90th percentile low flows. The major increases in TDS under this level of development occur from July to October in both flow regimes; however, effects are more noticeable under drought conditions. As noted on other levels of development, the inclusion of a one ton per acre per year salt pickup does not greatly increase TDS levels through any of the months with the possible exception of August. Projected TDS concentrations in the Yellowstone River at Billings under this level of develop- ment are somewhat higher than those projected from the others, but not to a large degree. As a result, conditions defining the high level of development would not be expected to cause alterations in the TDS levels in the river in sufficient magnitude to affect its use. Other Parameters In general, other parameters should show only minor changes under any level of development. Possible exceptions might be evident during August and Sep- tember of low-flow years. Nintieth percentile flows are reduced approximately 50 percent during these two months. Such a drastic reduction in flow could adversely affect the river's ability to assimilate waste from the Billings area and result in high water temperatures and reduced dissolved oxygen levels that would temporarily stress the aquatic ecosystem. Data were not available to quantify these effects. Conclusion Although both the intermediate and high levels of development would cause measurable increases in TDS and a general reduction in water quality, the Yellowstone River would still contain water of fairly high quality suitable for almost all beneficial uses. BIGHORN SUBBASIN Total Dissolved Solids The usual inverse relationship between TDS and discharge (Q) has been obliterated because of storage and regulation by Yellowtail dam. Insufficient below-dam records were available to develop monthly relationships, and a single equation for all months failed to predict seasonal variations. Therefore, a two-stage method was used to obtain initial TDS concentrations: 1) average monthly TDS concentrations for the 1968-74 period were computed for the Bighorn River near St. Xavier (figure 7); and 2) thirty-nine months of concurrent water quality rec.ords (1966-69) at two stations--Bighorn River near St. Xavier and Bighorn River at Bighorn--were used to develop the following linear regression equation (11): TDSB = 57.1 + .93596 TDSsx (r2 = .928) 311 ' "' E (f) 0 1- .?- .<: -c 0 :::E ., "' 0 ~ ., ~ 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 ---Time Weighted Average Oct Figure 7. Average monthly TDS concentrations in the Bighorn River near St. Xavier, 1968-74. 312 where: TDSR is the average monthly TDS at Bighorn, and TDSsx is the average monthly TDS near St. Xavier. Equation (11) was used with the average monthly TDS concentrations near St. Xavier from figure 7 to compute average monthly TDS values for the Bighorn River near Bighorn; this became the basis for LTDST of figure 2 and equation (2) (equations 1 through 10 are presented in "Impacts of Water Withdrawals" in the Methods section of this report). Results for the Bighorn Subbasin are presented in tables 138 and 139 and figures 8 and 9, and summarized below for the intermediate and high levels of development . A low level of development was not formally simulated because the effects on flow and TDS would have been insignificant. Intermediate Level of Development. The annual average TDS concentration increased 1.5 percent for the 50th percentile flow and 2.2 percent for the 90th percentile flow with 0 salt pickup, and 1.9 percent 3.1 percent for 1 ton per acre per year salt pickup. Most of the increase occurred in July and August. At the 90th percentile flow level, for example, TDS concentrations in August increased from 475 mg/1 (natural) to 526 mg/1 and 557 mg/1 for 0 and 1 ton per acre per year salt pickup. High Level of Development. Annual TDS concentrations were less than 2 percent higher than comparable values under the intermediate level of devel- opment. Again, July and August accounted for most of the increase. August increases ranged from 5.3 percent for 50th percentile flows with no salt pickup to 32 percent for 90th percentile flows with one ton per acre per year salt pickup. Salinity levels near the mouth of the Bighorn River would increase somewhat in normal years. (Assuming 0 salt pickup, 50 percentile values in August would increase from 475 mg/1 to 575 mg/1.) A series of dry years, accompanied by the higher TDS concentrations, could adversely affect cropland irrigated with the water. In general, however, irrigators should experience no major new problems under either level of development. Other Parameters The increase in TDS will be accompanied by increases in ilardness and S04 (sulfate) concentration, all of which will render the water less desirable for domestic purposes. Fiftieth percentile flow S04 values for August, will increase from 216 mg/1 to 288 mg/1 under the high level of development with 1 ton per acre per year salt pickup (based on the equation S04 = -54.0 + .56781 TDS (r2 = .978). Nintieth percentile flow values will exceed 300 mg/l for the same month and level of development. The recommended limits for drinking water are 250 mg/1 for S04 and 500 mg/1 for TDS. These limits are presently exceeded during much of the year, and they would be exceeded even more under the intermediate and high levels of deve 1 opment. Although no limits have been established for hardness, current Bighorn River water is considered hard, averaging more than 300 mg;l as CaC03. Hardness will 313 w .... ... TABLE 138. TDS values in the Bighorn· River, assuming an intermediate level of development without the Fish and Game flows. 50th Percentile Values 90th Percentile Values Simulated Simulated Historical Historical Q TDS Q TDS at a Salt pickup of: Q TDS Q TDS at a Salt pickup of: 0 lz 1 0 lz 1 (a f) (mg/1) (a f) (mg/l) (mg/l) (mg/l) (a f) (mg/1) (a f) (mg/1) (mg/l) (mg/1) Oct 197,267 622 194,045 626 629 131,491 622 140,169 627 631 Nov 183,408 588 184,077 591 593 108,807 588 142,153 590 591 Dec 170,710 sg2 164,977 594 595 115,815 592 109,022 595 597 Jan 144,461 573 143,34g 575 576 102,107 573 100,767 576 577 Feb 144,973 607 144,398 609 610 109,160 607 107,600 609 610 March 199,787 627 211 ,631 628 629 116,122 627 157,238 629 630 Apri 1 182,515 621 204,188 623 624 123,442 621 119,215 624 626 May 280,501 628 259,527 632 634 103,152 628 135,198 635 640 June 464,795 609 566,793 612 613 165,561 609 137 ,846 618 625 July 312,406 552 261,441 559 563 58,461 552 30,130 609 647 Aug 143,048 475 81,338 500 512 78,132 475 36,351 526 557 Sept 172,343 502 155,622 508 512 98,694 502 91 ,851 512 519 folua 1 2,596,214 588 2,571,386 597 599 1,310,944 590 1,307,540 603 608 aSalt pickup given in tons per acre per year. '"" -01 TABLE 139. TDS values in the Bighorn River at Bighorn, assuming a high level of development without the Fish and Game flows. 50th Percentile Values 90th Percentile Values Simulated Simulated Historical TDS at a Historical TDS at Q TDS. Q Salt pickup of: Q TDS Q Salt pickupa of: 0 ~ 1 0 '> 1 (a f) (mg/l) (a f) (mg/l) (mg/l) (mg/l) (a f) · (mg/l) (a f) (mg/l) (mg/l) (mg/l) Oct 197,267 622 188,241 628 632 131 ,491 622 134 ,252 628 631 Nov 183,408 588 180,204 592 594 108,807 588 138,223 593 596 Dec 170,710 592 160,974 595 597 115,815 592 104,977 597 601 Jan 144,461 573 139,343 576 578 102,107 573 96,807 577 580 Feb 144,973 607 140,336 609 611 109,160 607 107,737 610 612 March 199,787 627 207,573 629 630 116,122 627 153,146 630 632 Apri 1 182,515 621 198,322 623 625 123,442 621 113,168 625 629 May 280,501 628 234,007 634 639 103,152 628 109,680 642 651 June 464,795 609 534,673 613 615 165,561 609 105,791 628 640 July 312,406 552 204,851 565 573 58,461 552 30,000 640 697 Aug 143,048 475 35,368 555 603 78,132 475 30,000 569 626 Sept 172,343 502 131,494 513 521 98,694 502 57,261 528 545 Amual 2,596,215 588 2,355,386 603 607 1,310,944 590 1,181,042 610 618 aSalt pickup given in tons per acre per year. 800 700 Level or Development -·-·--· High High ------Intermediate Historical Salt Pickup (ton a I acre/year) I 0 0 -600 :::: ·:-.... ...... - k "' .s "' 0 .... 500 ~ 400 ~ c 0 :IE .. "' 2 .. 300 ~ 200 :::: "' E "' 0 .... ~ " 'E 0 :IE .. "' 2 .. > "" 100 NOTE: 50 1h Percentile Values without F 8 G Flows o+---r--.---.--.---r--.---.--.---.--.---.~ Oct Nov Dec Jon Feb Mar Apr May June July Aug Sept Figure 8. Average monthly TDS in the Bighorn River near Big- horn at 50th percentile values. 800 700 600 500 400 300 200 100 Level or Development High High Intermediate Historical Salt Pickup (tons I acre/year) I 0 0 NOTE' goth Percentile Values without F 8 G Flows o+---~--r--,--~~-r~.---~--r--,---.---.--~ Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Figure 9. Average monthly TDS concentrations in the Bighorn River near Bighorn at 90th percentile values. 316 increase linearly with TDS. Therefore, problems associated with hard water--the necessity for using more soap in cleaning and laundering, the formation of scales in pipes, and the need to soften water before using it for certain purposes--will increase proportionately. Projected increases in hardness are so slight that consumers, principally residents of Hardin who draw their water supply from the Bighorn River, would hardly notice the change. Major reductions in flow (50 percent or more) projected under both levels of development for July, August, and September, could have adverse impacts on other water quality parameters such as dissolved oxygen and temperature; this, in turn, could produce deleterious effects on the aquatic ecosystem. Discharges of 30,000 af (488 cfs) during July and August are less than historical extreme low flows both before and after the completion of Yellowtail dam. Therefore, it would be beneficial to maintain higher flows, of about 1000 cfs, in the river during all months. This flow would enhance water quality and improve the aquatic environment. Summary The intermediate level of development would produce only minor changes in water quality. Degradation of water quality under the high level of develop- ment would be somewhat more severe, especially in dry years. Bighorn River water is naturally high in total dissolved solids, including sulfate, and is hard. Values of all three of these parameters will increase, and thus render the water less desirable for beneficial uses. Furthermore, the low flows projected for July and August could result in detrimental changes in dissolved oxygen and water temperatures, with concomitant injury to the aquatic ecosystem. MID-YELLOWSTONE SUBBASIN Total Dissolved Solids Only six years (1969-74) of TDS records were available on the Yellowstone River near Miles City, not enough to derive monthly relationships between TDS and Q. A significant relationship was obtained using data for all months, but it failed to accurately reflect the monthly variation in TDS. Consequently, monthly values of TDS at Miles City were obtained from regression equations between: (a) TDS and Qat Sidney, (b) TDS at Miles City and TDS at Sidney, and (c) Q at Sidney and Qat Miles City. Basically, the computational procedure was as follows: 1) Monthly values of Q were determined from hydrologic simulations. 2) The regression equation between Q at Sidney and Q at Miles City was used to obtain Qat Sidney corresponding to Q from step 1. The equation (figure 10) is: (12) OsD = -1.388 + 1.126 QMc 317 ... -(.) .. .. :IE ~ D ., z ~ ., .:: 0: .. c D -.. J: D ~ ~ -w D .... ~ C> ., "' ~ D .c u ., 0 ... .c -c D :I (.) :IE 0 3,000,000 2,500,000 2,000,000 • 1,500,000 1,000,000 Oso = -1.388 + 1.126 QMC r = .97 500,000 0~-------r-------r-------r-------r-------r-------r------~ 0 500,000 1,000,000 1,500,000 2,000,000 2,500,000 3,000,000 3,500,000 Oso : Monthly Discharc;~e (af) Yellowstone River Near Sidney Figure 10. Discharge relationship between the Yellowstone River near r·1iles City and the Yellowstone River near Sidney. where: QSD = discharge at Sidney, 1000 af QMC = discharge at Miles City, 1000 af 3) QsD from step 2 and the appropriate monthly TDS-Q relationship for the Yellowstone River near Sidney (table 153) were used to obtain TDS for Sidney. 4) The regression equation between TDS at Miles City and TDS at Sidney (figure 11) was used to obtain TDS at Miles City corresponding to Q from step 1. The procedure described is somewhat circuitous, but it more accurately reflects monthly variations in TDS than the use of a single relationship for all months. Results are presented in tables 140-142 and in figures 12 and 13, and are discussed below. Low Level of Develo~ment. Diversions and return flows under this level of development would pro uce minor changes in TDS concentrations. Annual values would increase 3.0 percent (3.2 percent with a salt pickup of 1 ton per acre per year) with 50th percentile flows; and 3.7 percent (4.2 percent with salt pickup of 1 ton per acre per year) with 90th percentile flows. Significant increases occur only during July to September, when TDS values average 9.6 percent (10.1 percent with salt pickup of 1 ton per acre per year) higher at 50th percentile flows and 10.9 percent (11.7 percent with salt pickup of 1 ton per acre per year) higher at 90th percentile flows. August increases are approximately 15 percent at 50th percentile flows and 20 percent at 90th percentile flows. Projected increases in TDS would not be sufficient to affect use of the water for common beneficial uses. September values, for example, would be 507 mg/1 at 50th percentile flows and 565 mg/1 at 90th percentile flows. Intermediate Level of Develo ment. Annual average TDS values would be 4.0 percent 4.8 percent with salt p1ckup) higher than for natural concentra- tions at 50th percentile flows, and 5.1 percent (6.8 percent with salt pickup) higher at 90th percentile flows. Most of the increase would occur during the July-to-October period. Monthly TDS increases would be generally less than 10 percent except during August, when increases would be 21 percent (24 percent with salt pickup) under 50th percentile flows, and 33 percent (37 percent with salt pickup) under 90th percentile flows. Also, during July there would be an increase of 15 percent (17 percent with salt pickup) under 90th percentile flows. Projected TDS concentrations should pose little or no additional threat to current beneficial uses. Only August and September concentrations would be significantly higher than naturally occurring values: 50th percentile values would increase from 389 mg/1 to 472 mg/1 during August, and from 473 mg/1 to 518 mg/1 during September; 90th percentile values would increase from 459 mg/1 to 610 mg/1 during August, and from 595 mg/1 to 583 mg/1 during September. High Level of Development. Average annual TDS increases would be less than 10 percent. Average annual values are misleading, however, because of the weighting effect of June, which produces the largest flow (26 to 28 percent of annual volume) and the lowest TDS concentrations of any month. Some months would show substantially higher increases that would render the water less 319 w "' 0 600 >-~ (.) ., .!! :::E ~ 500 0 .. z ~ ., .:!: a: ., c: 400 0 -II) ): .2 ~ ' "' 300 • E ~ "' 0 • 1- ~ ~ -200 c: 0 • :::E .. TDSMC = -25.7 + .9598 TDSso "' 0 ~ r = .953 "' > < 100 (.) :::E "' 0 1- 0 ~------~--------.--------.-------.--------~-------r------~ 0 100 200 300 400 500 600 700 TDSso: Averooe Monthly TDS (mo/ll Yellowstone River Near Sidney Figure 11. TDS relationship between the Yellowstone River near 11iles City and the Yellow- stone River near Sidney. w N ...... TABLE 140. TDS values in the mid-Yellowstone River, assuming a low level of development with no reservation or Fish and Game flows. 50th Percentile Values 90th Percentile Values Simulated Simulated Historical TDS at Historical TDS at Q TDS Q Salt pickupa of: Q TDS Q Salt pickupa of: 0 ~ 1 0 ~ 1 (a f) (mg/1) (a f) (mg/1) (mg/1) (mg/1) (a f) (mg/1) (a f) (mg/1) (mg/1) (mg!]) Oct 484,960 477 462,205 488 48g 340,670 560 323,536 573 574 Nov 414,095 517 4og,310 518 520 322,048 578 333,575 568 570 Dec 348,555 572 337,255 577 580 221,141 657 217,102 657 661 Jan 301,526 590 296,842 589 594 199,194 672 lg4,918 667 676 Feb 301,438 542 302,286 544 542 230,446 580 225,893 578 584 March 471 ,873 493 488,389 486 488 298,629 568 294,533 568 572 Apri 1 477,479 545 465,915 547 549 334,211 582 326,058 583 586 May 1,079,204 304 988,032 322 323 523 '115 412 439,194 430 431 June 2,234,590 251 2,129,436 247 249 1,280,809 214 1 '175,717 213 213 July 1,240,724 255 1,080,117 272 273 547,511 290 436 ,485 315 317 Aug 458,038 389 305,904 447 449 275,029 459 170,649 553 559 Sept 428' 158 473 ' 342,057 507 510 252,952 545 218,790 565 568 Amual 8,240,640 372 7,607,748 383 384 4,825,755 428 4,348,450 444 446 aSalt pickup given in tons per acre per year. w N N TABLE 141. TDS values in the mid-Yellowstone River, assuming an intermediate level of development with no reservation or Fish and Game flows. 50th Percentile Values 90th Percentile Values Simulated Simulated Historical TDS at Historical Q TDS Q Sa 1t pi ckupa of: Q TDS Q TDS at a Salt pickup of: 0 la 1 0 la 1 (a f) (mg/1) (a f) (mg/1) (mg/1) (mg/1) (a f) (mg/1) (a f) (mg/1) (mg/1) (mg/1) Oct 484,960 477 459,151 493 497 340,670 560 320,492 579 585 Nov 414,095 517 406,677 521 526 322,048 578 330,930 570 577 Dec 348,555 572 334,446 579 585 221,141 657 214,307 659 669 Jan 301 ,526 590 293,910 589 599 199.194 672 191,983 669 685 Feb 301 ,438 542 299,204 537 546 230,446 580 222,809 577 589 March 471 ,873 493 485,442 488 491 298,629 568 291,594 570 576 Apri 1 477,479 545 462,291 549 553 334,211 582 322 ,432 586 591 May 1 ,079,204 304 975,673 326 329 523,115 412 426,837 439 444 ' June 2,234,590 251 2 ,114,183 249 251 1,280,809 214 1,160,467 216 218 July 1 ,240. 724 255 1 ,053,213 278 280 547,511 290 409,575 332 339 Aug 458,038 389 284,700 472 483 275,029 459 149,464 610 630 Sept 428,158 473 331 • 134 518 524 252,952 545 199,867 583 593 Annual 8,240,640 372 7,500,023 387 390 4,825,755 428 4,240,757 450 457 aSalt pickup given in tons per acre per year. w N w TABLE 142. TDS values in the mid-Yellowstone River, assuming a high level of development with no reservation or Fish and Game flows. 50th Percentile Values 90th Percentile Values Simulated Simulated Historical TDS at a Historical TDS at a Q TDS Q Salt pickup of: Q TDS Q Salt pickup of: 0 ~ 1 0 ~ 1 (a f) (mg/l) (a f) (mg/1) (mg/l) (mg/1) (a f) (mg/l) (a f) (mg/l) (mg/l) (mg/1) Oct 464,960 477 448,648 500 506 340,670 560 310,188 589 598 Nov 414,095 517 398,081 525 533 322,048 578 322,045 576 585 Dec 348,555 572 325,382 582 592 221,141 657 205,456 662 678 Jan 301,526 590 264,947 591 605 199,194 672 182,934 672 693 Feb 301,438 542 290,037 537 551 230,446 580 213,586 577 595 March 471,873 493 476,136 489 495 298,629 568 282,481 573 581 Apri 1 477,479 545 451 • 155 552 557 334,211 582 311 ,278 590 598 May 1,079,204 304 935,515 335 339 523,115 412 386,800 452 461 June 2,234,590 251 2,064,900 249 251 1,280,809 214 1 ,111 ,223 216 221 July 1,240,724 255 968,080 286 291 547,511 290 352,967 351 365 Aug 458,038 389 215,827 527 548 275,029 459 92,445 762 808 Sept 428,158 473 291,202 539 549 252,952 545 137,652 629 648 Pilnua 1 8,240,640 372 7,149,910 392 398 4,825,755 428 3,909,055 458 469 aSalt pickup given in tons per acre per year. 1000 900 800 700 ' "' E en 600 c 1- .?-500 ""' -c 0 :IE 400 CD "' 0 ~ CD > 300 <I 200 100 0 Oct Nov Jon Level of Development High High Intermediate Historical Feb Mar Apr Salt Pickup (tons/acre/year) I 0 0 ~--·-·1 ·•············· ( ................ " .--{1 .,·I /; l; fl J/ ... ~. ~ NOTE, 501h Percentile Values without F a G Reservation without F a G Flows May June July Aug Sept Figure 12. Comparison of historical and simulated TDS concen- trations in the Yellowstone River near Miles City at 50th percentile values. 324 1000 900 800 ~ 700 :::;:: "' E en 600 0 1-,.. 500 :c -c:: 0 ::;; .. 400 "' 0 ~ .. > 300 <t 200 100 0 Oct Level of Development -·-·-·-· High ····················· High ------Intermediate Historical Nov Dec Jon Salt Pickup (tons /acre/year) I 0 0 "· i~. \ "i · .. \ 1: ·· ... \ j! ···· .. \ j/ -·· .. :.\ .; . t , __ _ ·:: I -.._ f: I r 1 ·; I [I #I .: I [, ,, /J // !'/ NOTE: goth Percentile Values without F a G Reservation without F a G Flows Figure 13. Comparison of historical and simulated TDS concentra- tions in the Yellowstone River near Miles City at 90th percentile values. 325 desirable. for beneficial uses, especially during August, September, and October of dry years. At 50th percentile flows, August and September concentrations would be 36 percent (41 percent with salt pickup of 1 ton-per acre per year), and 14 percent (16 percent with salt pickup of 1 ton per acre per year) higher than existing levels. Corresponding 90th percentile values would be 66 percent (76 percent) and 15 percent (19 percent) higher. Resulting concentrations would shift the water from a medium to a high salinity hazard (Richards 1954) during August, September, and October under both 50th percentile flows and 90th percentile flows. TDS concentrations would exceed 500 mg/1 eight months of the year at 50th percentile flows--three more than under current conditions. TDS concentrations would exceed 500 mg/1 nine months of the year at 90th per- centile flows--one more than under current conditions, and 600 mg/1 four months of the year--two more than under current conditions. As shown in figures 12 and 13 the high level of development would degrade water quality significantly more than the intermediate level -of development during the July-October period, particularly during low-flow years. Irrigators, municipalities, and industry would experience higher costs and more management problems associated with the use of more saline water. Other Parameters Reduction in flow and increases in TDS concentrations would result in the degradation of other water quality parameters. Common dissolved constituents are approximately linear functions of TDS and would show proportionate increases. Sulfate, for example, would increase from 194 mg/1 to 273 mg/1 as TDS increases from 450 mg/1 to 600 mg/1 (S04 = -42.18 + .5256 TDS; r = .995). The Montana standard for sulfate in the Yellowstone River is 250 mg/1. The SAR would in- crease slightly (SAR = 0.4687 + .00264 TDS; r = .950), from about 1.66 to 2.05 as TDS increases from 450 mg/1 to 600 mg/1, but the water would still have a low sodium hazard (Richards 1954). Each hundred-unit increase in TDS would increase the hardness of the water by approximately 40 mg/1. Since the water is already hard (200 mg/1 as caco 3 at a TDS of 380 mg/1), further increases would be undesirable. Nutrients levels may rise because of increased use of fertilizers on new irrigation lands and because of the concentrating effect of reduced streamflows. Water temperatures would increase slightly but probably less than 1°C. Diurnal variations in temperature and dissolved oxygen would increase slightly. Summary The low level of development would produce a slight reduction in water quality. Degradation would be somewhat more severe under the intermediate level, but major beneficial users would probably experience few long-term adverse impacts. The high level of development, however, would bring significant de- leterious effects on water quality, particularly during low-flow years. Water quality would not degrade to the point that the water would be rendered unsuit- able for beneficial uses, but it would require more costly treatment or more careful management. ~6 TONGUE SUBBASIN Total Dissolved Solids Nineteen years of monthly records (1951-1969) on the Tongue River near Miles City were used to derive the regression equations between TDS and Q listed in table 143. All monthly equations are significant at the 1 percent level. The equations represent historical conditions with the existing Tongue River Reservoir at 68,000 af capacity in place. The intermediate and high levels of development project a 320,000-af reservoir at the same site, and the low level assumes a 112-af reservoir. Enlargement of the Tongue River Reservoir would modify the conditions upon which the regression equations were based. The extent of the modifications cannot be accurately predicted. Therefore, first the equations in table 143 were used unaltered for all levels of development according to the methodology illustrated in figure 2 (in the Methods section of this report). To check the results, TDS values at Miles City were recomputed based on water quality and discharge records for the Tongue River at the state border, assuming complete mixing in the reservoir according to equations (8), (g), and (10) (in "Impacts of Water Withdrawals" under the Methods section), and following the logic of figure 2. Results of the first simulations are presented in tables 144-147 and in figures 14 and 15, and are summarized briefly below. Note that in most instances,·monthly increases in TDS concen- trations are much more severe than those indicated by annual values, which reflect the diluting effect of the spring runoff. Annual changes in TDS concentrations showed a 1 percent ecrease 53 percent increase with a salt pickup of 1 ton per acre per year) at 50th percentile flows and a 16 percent (28 percent with a salt pickup of 1 ton per acre per year) increase at 90th percentile low flows. In- creases from July through November would be substantial, averaging 48 percent (87 percent with salt pickup of 1 ton per acre per year) higher at 50th percen- tile flows and 79 percent (149 percent with salt pickup) higher at 90th percen- tile flows. Actual concentrations would average 746 mg/1 (944 mg/1 with salt pickup) at 50th percentile flows, compared with 502 mg/1 under current conditions. August concentrations would increase by factors of 2.4 (3.9 with salt pickup) and 2.0 (3.0 with salt pickup) at 50th percentile and 90th percentile flows, or from 509 mg/1 to 1238 mg/1 (1973 mg/1 with salt pickup) and from 765 mg/1 to 1565 mg/1 (2300 mg/1 with salt pickup). Intermediate Level of Develo ment. Annual increases in TDS concentrations would be 20 percent 39 percent with salt pickup of 1 ton per acre per year) at 50th percentile values, and 39 percent (78 percent with salt pickup) at 90th percentile values. Values in July and August at 50th percentile flows would increase by factors of 2.4 (3.9 with salt pickup) to 3.1 (5.1 with salt pickup). TDS concentrations at 50th percentile flows would exceed 600 mg/1 10 months of the year; TDS concentrations at 90th percentile flows would exceed 679 mg/1 every month of the year. Concentrations in July and August would exceed 1149 mg/1 (1884 mg/1 with salt pickup) at 50th percentile flows. TDS concentrations would exceed 1277 mg/1 (2012 mg/1 with salt pickup) from June through October at 90th percentile flows, making the water undesirable for most beneficial uses. 327 TABLE 143. Regression equation between TDS concentrations and monthly discharge (Q) in the Tongue River near Miles City, 1951-1969. Month Best Fit Equation r2 Significance Jan log TDS = 2.968046 -.00001178 Q . 373 a Feb log TDS = 2.8869196 -.0000093196 Q .718 a Mar TDS = 1445.71 -217.25081 log Q .539 a Apr TDS = 1524.68 -217.70712 log Q .867 a May TDS = 1348.75 -191 . 64864 log Q .546 a June TDS = 1221.21 -189.03383 log Q . 750 a July TDS = 1513.50 -260.79199 log Q .815 a Aug TDS = 1686. 28 -301.87476 log Q .819 a Sept log TDS = 3.51775 -.20078 log Q .869 a Oct TDS = 164 7. 14 -265.4541 log Q .787 a Nov log TDS = 3,6g492 - . 21753 log Q .627 a Dec TDS = 2375.20 -408.74805 log Q .420 a All months TDS = 1672.10 · -267. 8859g. log Q .583 a NOTE: TDS concentrations represent average monthly figures in mg/1; Q figures are in acre-feet. aSignificant at 1 percent level. High Level of Development Without Fish and Game Flows. Because of the large storage capacity and the elimination of flows for instream purposes, flows and concentrations would be fairly uniform throughout the year, consisting essentially of irrigation return flow except during the June 50th percentile values when excess water must be released. Annual TDS concentrations would be 41 percent (88 percent with salt pickup of 1 ton per acre per year) and 60 per- cent (128 percent with salt pickup) higher than historical values, and would average about 1180 mg/1 (1900 mg/1 with salt pickup) and 1280 mg/1 (2000 mg/1 with salt pickup) during most months at 50th percentile and 90th percentile flows, respectively. 328 w N <0 TABLE 144. TDS values in the Tongue River, assuming a low level of development with 100 percent of the Northern Great Plains Resources Program's Fish and Game flows. 50th Percentile Values 90th Percentile Values .. Simulated Simulated Historical TDS at Historical Q TDS Q Salt pickupa of: Q TDS Q TDS at a Salt pickup of: 0 '> 1 0 ~ 1 (a f) (mg/l) (a f) (mg/1) (mg/1) (mg/l) (a f) (mg/1) (a f) (mg/l) (mg/l) (mg/l) Oct 14,569 540 6,585 682 715 748 2,152 762 1 ,562 1 ,062 1,285 1,338 Nov 17,490 590 6,365 753 774 795 5,533 760 4,943 825 852 879 Dec 12,356 703 8,390 775 787 800 6,332 820 5,667 860 879 898 Jan 10,266 700 8,320 740 750 759 8,114 740 7,379 766 777 788 Feb 11 • 882 596 8,245 646 653 659 6,385 670 5,834 681 690 700 March 28,278 480 23,812 499 502 505 13,524 548 12,260 570 578 583 April 24,569 570 23,129 581 . 586 590 8,923 665 11 ,375 653 662 672 May 43,154 459 44,807 465 472 478 12,479 563 15,337 584 603 622 June 82,096 291 103,865 279 283 286 13,564 440 4,479 746 831 915 July 25,204 368 13.994 442 471 499 3,135 604 1 • 315 1 ,565 1,933 2,300 Aug 7,746 509 1 ,315 l,238 1,606 1 • 973 l, 107 765 1 ,315 1 ,565 1,933 2,300 Sept 11 • 541 501 6,730 614 654 693 1 ,190 800 730 1 ,457 1,825 2,192 Jlllrua 1 289,151 454 255,557 448 458 468 82,438 623 72,196 722 761 796 aSalt pickup given in tons per acre per year. w w 0 TABLE 145. TDS values in the Tongue River, assuming an intermediate level of development with 60 percent of the Northern Great Plains Resources Program's Fish and Game flows. 50th Percentile Values 90th Percentile Values Simulated Simulated His tori ca 1 TDS at Historical TDS at a Q TDS Q Salt pickupa of: Q TDS Q Salt pickup of: 0 ~ 1 0 llj 1 (a f) (mg/1 ) (a f) (mg/1) (mg/1) (mg/1) (a f) (mg/1) (a f) (mg/1) (mg/1) (mg/1) Oct 14,569 540 4,770 767 947 2,152 762 1 ,170 1 ,277 2,012 Nov 17,490 590 4,335 800 925 5,533 760 2,338 955 1 ,186 Dec 12,356 703 5,445 816 895 6,332 820 2,862 886 1,036 Jan 10,266 700 5,300 775 836 8,114 740 4,624 800 870 Feb 11 ,882 596 5,150 674 715 6,385 670 2,745 719 796 March 28,278 480 7,640 605 647 13,524 548 7,640 610 652 Apri 1 24,569 570 8,860 669 717 8,923 665 5,133 736 819 May 43.154 459 17,205 566 634 12,479 563 9,237 679 807 June 82,096 291 57,310 344 370 13,564 440 2,045 1 ,371 2 ,1 07 July 25,204 368 2,630 1 '149 1 ,884 3,135 604 2,630 1 ,371 2 '106 Aug 7,746 509 2,630 1 ,236 1 ,971 1 '1 07 765 2,630 1 ,371 2,106 Sept 11 ,541 501 4 '182 776 1 ,033 1 '190 800 1,460 1 ,372 2,107 A1nual 289,151 454 125,457 547 633 82,438 623 44,514 869 1 ,110 aSalt pickup given in tons per acre per year. w w .... TABLE 146. TDS values in the Tongue River, assuming a high level of development without the Fish and Game flows. 50th Percentile Values 90th Percentile Values Simulated Simulated Historical TDS at Historical TDS at a Q TDS Q Salt pickupa of: Q TDS Q Salt pickup 0 ~ 1 0 ~ (a f) (mg/1) (a f) (mg/1) (mg/1) (mg/1) (a f) (mg/1) (a f) (mg/1) (mg/1) Oct 14,569 540 1 • 755 1,178 1 ,545 1 ,913 2,152 762 1 • 755 1,282 1 ,650 Nov 17,490 590 1,097 1 ,177 1,545 1 ,913 5,533 760 1 ,097 1,282 1 ,650 Dec 12 ,356 703 878 1 ,177 1 ,545 1 • 912 6,332 820 878 1 ,282 1,649 Jan 10,266 700 658 1 ,178 1,545 1 ,913 8,114 740 658 1 ,283 1 ,650 Feb 11,882 596 439 1 ,177 1 ,545 1 ,912 6,385 670 439 1 ,282 1 ,649 March 28,278 480 658 1,172' 1,540 1,908 13,524 548 658 1 ,283 1 ,650 April 24,569 570 878 1 ,136 1 ,504 1 ,872 8,923 665 878 1 ,282 1,649 May 43.154 459 2,413 1 ,137 1 ,505 1 ,872 12,479 563 2,413 1 ,282 1,650 June 82,096 291 45,968 379 404 429 13,564 440 3,072 1 ,281 1,650 July 25,204 368 3,949 1 ,178 1 ,545 1 ,913 3,135 604 3,949 1,282 1,650 Aug 7,746 509 3,949 1.178 1,545 1,913 1,107 765 3,949 1,282 1,650 Sept 11 ,541 501 2,194 1 ,177 1,545 1 ,913 1 ,190 800 2,194 1,282 1 ,650 l'finua 1 289,151 454 64,836 609 734 857 82,438 623 21,940 1 ,282 1,650 aSalt pickup given in tons per acre per year. of: 1 (mg/1) 2,018 2,017 2,017 2,018 2,017 2,018 2,017 2,018 2,017 2,018 2,018 2,017 2,018 w w N TABLE 147. TDS values in the Tongue River, assuming a high level of development with Fish and Game flows. 50th Percentile Values 90th Percentile Values Simulated Simulated Historical TDS at Historical TDS at a Q TDS Q Salt pickupa of: Q TDS Q Salt pickup 0 !:; 1 0 !:; (a f) (mg/1) (a f) (mg/1) (mg/1) (mg/1) (a f) (mg/1) (a f) (mg/1) (mg/1) Oct 14,569 540 2,655 1 ,003 1,246 1 ,489 2,152 762 2,655 1 ,077 1 ,313 Nov 17,490 590 1,997 998 1 ,200 1 ,402 5,533 760 1 ,997 1 ,054 1 ,256 Dec 12 ,356 703 1 • 778 1 ,018 1 ,200 1 ,381 6,332 820 1 ,778 1 ,069 1,250 Jan 10,266 700 1 ,558 967 1 ,122 1 ,277 8,114 740 1,558 1 ,010 1 ,165 Feb 11 ,882 596 1,339 852 972 1 ,093 6,385 670 1 ,339 885 1 ,006 March 28,278 480 3,358 722 794 866 13,524 548 3,358 743 815 April 24,569 570 3,578 793 883 973 8,923 665 3,578 828 918 May 43,154 459 5,113 827 1 ,000 1 ,174 12 ,479 563 5,113 895 1 ,069 June 82,096 291 40.320 394 422 450 13,564 440 3,972 1 ,091 1 ,376 July 25,204 368 4,849 1 ,032 1 • 331 1 ,631 3,135 604 4,849 1 • 115 1 ,414 Aug 7,746 509 4,849 1 ,035 1 ,335 1 ,632 1 ,1 07 765 4,849 1 ,118 1 ,417 Sept 11 • 541 501 3,094 985 1 ,245 1 ,506 1 • 190 800 3,094 1 ,056 1 ,317 Alnua 1 289,151 454 74,488 638 747 855 82,438 623 38,140 998 1 ,210 aSalt pickup given in tons per acre per year. of: 1 (mg/1) 1 ,556 1,458 1 ,432 1,320 1 ,126 887 1,008 1 ,242 1 ,660 1 • 714 1 • 717 1,578 1 ,421 ~ ...... "' ..§. Cl) 0 1-,.. J: -c 0 :IE .. "' 0 ~ .. > c( 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 ' 500 400 300 200 100 Level of Development Salt Pickup (tons/acre/year) -· -· -·-High without F 8 G Flows 0 -----High with F8 G Flows 0 -········· ·········· Intermediate with 60% NGPRP F 8 G Flows 0 -------Low with 100% NGPRP F 8 G Flows 0 Historical NOTE: 50 1h Percentile Volues •• -·-·-·-·-·--·-·-··-·-·-·-·-·• t7"'::<]l_. __ _ .............. ...-I l. ---·-·-~ r I f \ i I ~ I l I' I I i I ,.,...--.-...,"-______ .......__ I I ...... ............. I il I 1\"'• '. I j' I 1\ ,, \ i I I I '. ' I ., I I ; \ . j/ I I '· ............ ········•· .. ····--... '\ /.---\ \ j, I \ \ •.. __ ....... . "' \ .I [/ I I • .-.... __ ·.. ' -,, I I "' ..... •·. \. .., .... / ''... y "' ,.... 'I II I I •" ' ··.. \ . !I I '-=<······..... ..··········..... \\ I ' ~ \ ···-... I I I \ / ''.., \\ : ~ .... \\\f f \ 't.: ,. .._ i I \"' I .._, I ii / 0 -r--~---.----r---~---r--~---.----r---~---r--~---. Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Figure 14. Comparison of historical and simulated TDS concentra- tions in the Tongue River near Miles C1ty at 50th percentile values. 333 1600 1500 1400 1300 1200 1100 1000 ..... "' E - U) 900 c 1- :;::. 800 .c; -c 0 ::lE ., 700 "' 0 ~ ., > 600 <( 500 400 300 200 100 0 ·-----, ' I ' I ', I '• I I I ~-·······--r·•·············•·············• ! I i I \----·-·-·+-·-·--·-·-··-----e-----------·-·-r-·r··-·--------- \ I I , I -•---..... . !~~ ' -~ I ' • -....... __ _., -' I • ' \ ' !, I \ ·• ... ' \. ' I ~~ \ . ' I \ t. \ /1 I ' ·········... ' i I \ ' I : \ '··-.. a, /• .' I \ "' ' I / : I \ ,/~ I Level of Development '.,/ J -····. I ·e I I I I ":-/ I Sol! Pickup (Ions/ acre/year) -·-·-·-High without FaG Flows 0 -----High with FaG Flows 0 ................... -. Intermediate with 60% NGPRP Fa G Flows 0 -------Low with 100% NGPRP FaG Flows 0 Historical NOTE: goth Percentile Values Oct Nov Feb Mar Apr May June July Aug Sept Figure 15. Comparison of historical and simulated TDS concentra- tions in the Tongue River near Miles City at 90th percentile values. 334 , • High Level of Development with Fish and Game Flows. The higher flows at this level of development would alleviate somewhat the impacts projected under the high level of development without the fish and game flows, but TDS concentrations would still increase substantially over present values. Monthly TDS values would average over 1000 mg/1 (1500 mg/1 with salt pickup of 1 ton· per acre per year) from July through December at 50th percentile flows, and about 10 percent less than 90th percentile values. Overall, average annual concentrations would increase 60 percent (128 percent with salt pickup) at 50th percentile flows, and 41 percent (88 percent with salt pickup) at 90th percen- tile flows. July and .August concentrations would be somewhat less than under the intermediate level of development, but 11 out of 12 months would show TDS values exceeding 722 mg/1 (866 mg/1 with salt pickup) during 50 percent of the years. Check on Simulated TDS Concentrations. Because of the proposed enlarge- ment of the Tongue River Reservoir, the equations listed in table 143, which were the basis for simulating future TDS values, may not be valid in the future. Therefore, regression equations developed from five years (1966-1970) .of records on the Tongue River at the state border near Decker and equations (8), (9), and (10), which describe TDS changes in the reservoir, were used to check results. The applicable equations are given in table 148. TABLE 148. Regression equation between TDS concentrations and monthly discharge (Q) in the Tongue River at the state border near Decker 1966-1970 • . Months Best Fit Equation r2 Significance Mar-Apr · log TDS = 2.85147 -.00455 Q .45 a May-July log TDS = 3.0107 -.32961 log Q .84 b Aug-Feb log TDS = 3.10784-.35604 log Q .76 b NOTE: TDS concentrations represent average monthly figures in mg/1; Q represents monthly discharge in thousands of acre-feet. aSignificant at 5 percent level. bSignificant at 1 percent level. In essence, co, from equation (10) is used·to obtain LTDST of equation (2). TDS values obtained from using the state border records, method B, theoretically should be less than values obtained using records at Miles City, method A, be- cause method A reflects the natural increase in TDS between the ·dam and Miles City. In general, this expectation was realized. Figures 16-21 compare simulated TDS values from both methods for the various levels of development . Comparisons lead to the following comments: 1) There was good agreement between the methods at the 90th percentile flows. 335 -. ~ ' ... E en 0 1-,.. :c -c 0 :IE .. ... 0 ~ .. ~ 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 •·················• Miles City n------11 State Line Histaricol Percentile Values so'h- so'h NOTE' Law Level of Development 100% NGPRP F S G Flows ....... ········•·····-···-... ~ ~ .. ···· · ... ... · ·•·· .. ..•. : .. ... .... ..... 0 Salt Pickup 0 Salt Pickup ........... .... ::~... ··· .. , ........ ' ~---J:~----!l----ll---~---12:" ', . ' ... Oct Nov Dec Jan Feb Mar 'tl ..... ' . ' ' ' • :: ., :: j I~ ; I ! I I ! I I ! I 1 ! I I : I I ~ ! I I ~ ! I I ~ : I I ~ . I . ; I \ :I I • ! I I :1 I 'I il I I I b. j / .f July Aug Sept Figure 16. Comparison of TDS concentrations in the Tongue River at Miles City computed from records at Hiles City and the state bor- der, assuming complete mixing in the reservoir, and usi.ng the low level of development at 50th percentile values. 336 2800 2600 2400 2200 2000 -=-1800 ...... "' E ~ (f) 1600 0 1- ~ 1400 .r:; -c: 0 ::Iii ., 1200 "' 0 ~ ., > 1000 <[ BOO 600 400 200 J • ~ ' Oct •····· ········ ··• Miles City 1:1------11 State Line Historical Percentile Values NOTE: Low Level of Development 100% NGPRP F 8 G Flows ' . \ ..................... . ' ' \ n.. ............... n.. ton/acre/year Salt Pickup ton/acre/year Salt Pickup ~-···············. '1;1-----n.. I ', ••• I ', I ll I I I I I I I I !I " ll il ; I :I il 'I ;I 'I .... , / I /I / I .i I ····•/ ----"ll-------1:(_ ,....- ---~""" Dec Jan Aug Sept Figure 17. Comparison of TDS concentrations in the Tongue R·iver at Miles City computed from records at Miles City and the state bor- der, assuming complete mixing in the reservoir, and using the lm~ level of development at 90th percentile values. 337 1400 1300 1200 1100 1000 ~ 900 ::::: "' E. ~ IJl 800 0 1- ?--700 .<::: -c: 0 ::;: Cl) 600 "' 0 ~ Cl) > 500 <( 400 300 200 100 .... •·················• Miles City 11------a State Line Historical Percentile Values 0 Salt Pickup 0 Soil Pickup NOTE' Intermediate Level of Development 60% NGPRP F S G Flows ... ··········•···· .. ·· ··· .... ••• ··. ··· .... ··· ... ·· ... ......... ••• .··· ·. •••• • ' fl / I / I / I : / I ' ~ I ; I \ ; I \ j / I ' I \ . i I • ; I 1 ' I I f I 1 :I t1 'I !I j ........ •·. I I 'n. ---a.._ _-ll----""!l----n----a-- Oct Dec Jon Feb \ i ·, . '·... I '\.J ·,~ Aug Sept Figure 18. Comparison of TDS concentrations in the Tongue River at Miles City computed from records at Miles City and the state bor- der, assuming complete mixing in the reservoir, and using the inter- mediate level of development at 50th percentile values. 338 1 r ~ ' "' E ~ en 0 1- ~ .c -c 0 ::;: ., "' 0 ~ ., ~ r 2800 2600 2400 2200 2000 1800 1600 1400 1200 1000 800 600 400 200 •····· .............. Miles City 1:1------n State Line Historical Percentile Values I ton/acre/year Salt Pickup I ton/acre/year Salt Pickup NOTE' Intermediate Level of Development 60% NGPRP F 8 G Fows li' \ I '· I ; I ; I \ I \ I ; I '· I ', I ; I ·, I \ I \ I ; I. I ·· ... I I ~ ' ' ' ·· ...• ·· ... •············-•··············•···············• _.::1----Il---~ . --; ;r-. o I " I I I . I ' I : I u il ; I iJ 'I o I 'I !I 'I !I il '---..... , I ······································~ ·· ....•...... ' ' ' ):1..._ _.,.tl --n..._ ----tt--- 0 ~--~--~----~--~--,---~--~----~--~--~---r--~ Oct Nov Dec Jon Feb Mar Apr May June July Aug Sept Figure 19. Comparison of .TDS concentrations in the Tongue River at t1iles City computed from records at Miles City and the state bor- der, assuming complete mixing in _the reservoir, and using the inter- mediate level of development at 90th percentile values. 339 1400 1300 1200 1100 1000 ' 900 "' E ~ U) 800 0 ... ,.. 700 :;: -c 0 ::lii ., 600 "' 0 ~ .. > 500 < 400 300 200 100 .................... Miles City n------n State Line Historical Percentile Values NOTE' High Level of Development with F 8 G Flows ............•..........• , .. ···· ... 0 Salt Pickup 0 Salt Pickup 1::1----xx.. I ' .!. ..............•.... ', r' · .. ' /'' ··· ... -:... ···•·······... fi • ' t ' /'' ·· .... ', t n..., ··•·· I! ..... ,n... ... ···~ r ' •. tf .... ,'ll... ....... I! ' ..•.... ···· )l\ f ---',,'rl / \ \ { ' ,/ \\ ( ' ../ 1\ ,, ', ,'~ I\ { ' ""' \": '·' )r \\ \ { \ li \ ti \w .. Oct Nov Dec Jon Feb Mar Apr May Aug Sept Figure 20. Comparison of TDS concentrations in the Tongue River at Miles City computed from records at Miles City and the state bor- der, assuming complete mixing in the reservoir, and using the high level of development at 50th percentile values. 340 ' , 2800 2600 2400 2200 2000 ~ 1800 ' ..... "' E (/) 1600 0 1- J!:o 1400 .c:; -c 0 :::;; ., 1200 "' 0 ~ ., > 1000 <( 800 600 400 200 , 0 Percentile Values •··················• Miles City goth n-------n State Line goth Historical NOTE' High Level of Development with F 8 G Flows tan/acre/year Salt Pickup tan/acre/year Salt Pickup ~...a----il.. f"'"~ ', I .... ····•····-······· ''--1····· ·· ..... ll A I! ·· .. ·~., I/ .. '<:·.. I/ ,.............. 1/ "11... ··... I i '',-n.. ····... •. rj/ ......... ··...• hili '"1:1.,. ····.... ,_:.• ' ·. r ', ... ../ ' ·... /1 'l:l._ ··.... 'I ' ··.. . .. ····1 ', ·· ............ .-Ji ' .... b--.... Oct Nav Dec Jan Feb Mar Apr May June July Aug Sept Figure 21. Comparison of TDS concentrations in the Tongue River at 11iles City computed from records at Miles City and the state border, assuming complete mixing in the reservoir, and using the high level of development at 90th percentile values. 341 2) Fiftieth percentile values were consistently lower from method B. Except during the summer, method B produced TDS concentrations lower than historical values; this is not impossible considering the lessening effect of the reservoir, but it is probably unreal- istic considering the deterioration in quality between the dam and Miles City. 3) The general conclusions are the same under either method. Further development of the Tongue River would cause significant increases in TDS concentrations at Miles City, especially during the summer and fall. Other Parameters Major reductions in flow, accompanied by substantial increases in TDS, would produce significant deterioration of overall water quality. Dissolved constituents generally increase linearly with TDS concentrations. Sodium is naturally low and should not become a problem; the SAR would increase from 1.38 when TDS is 450 to 2.6 when TDS is 1200 (SAR = .573 + .00169. TDS; r = .708). Sulfate, on the other hand, is fairly high now--182 mg/1 at a TDS of 450 (S04 = -41.4 + .496 TDS; r = .985). It would reach 256 mg/1 for TDS con- centratlons of 600 mg/1 and 554 mg/1 for TDS concentrations of 1200 mg/1. Hardness also would increase substantially from its already high levels of 250-400 mg/1. Nutrients may increase because of the irrigation of new land and the concomitant increase in irrigation return flow. Water temperatures would be higher because of reduced streamflows, but the magnitude of these increases is difficult to predict. The waste assimilation capacity would be reduced, perhaps accompanied by a reduction in dissolved oxygen. TSS concen- tration tends to decrease as discharge is reduced. Moreover, the larger Tongue River Reservoir should remove more sediment from the water than the existing structure. However, these effects may be offset at least partially by the increased production of sediment from expanded mining and agricultural operations. Summary All levels of development analyzed for the Tongue River subbasin would produce significant reductions in water quality at Miles City, primarily be- cause of the combination of substantially reduced streamflows and increased salt loads from irrigation return flows. TDS, sulfate, and hardness would increase above the already high levels. Sodium would probably increase but not enough to cause a problem. The aquatic environment would be severely stressed by the low late suomer flows which would be higher in dissolved minerals and nutrients, possibly lower in dissolved oxygen, and subject to higher temperatures and increased diurnal variation in both temperature and dissolved oxygen. 342 ' r POWDER RIVER SUBBASIN Total Dissolved Solids The Powder River is characterized by large variations in flow and water quality. Historically, discharge at Locate, near the mouth, has varied from 0 to 31,000 cfs., with flows less than 30 cfs. and greater than 5000 cfs. common. The Powder River carries an extremely high sediment load and annually contributes several million tons of sediment to the Yellowstone River (an average of 6 million tons per year for 1951-1953 and 1974). In addition, the water carries a high and variable load of TDS concentrations. Because of the wide variation in discharge and quality, and the paucity of water quality records (1951-1963 is available on the Powder River near Locate), the regres- sion equations between TDS and discharge in table 149 generally are not as reliable as similar equations for the other subbasins. The listed equations, however, were used to obtain estimates of historical TDS values. The projected construction of a large dam on the Powder River at Moorhead required that equations (8), (9), and (10), which describe water quality changes in a reservoir, be employed. Analysis of concurrent records for the February 1951 to September 1953 period (the only period with records at Moorhead) re- vealed no statistically significant difference between average monthly TDS values of the Powder River near Locate and the Powder River at Moorhead. Con- sequently, equations between TDS and Q for the Powder River near Locate (table 149) were used to calculate TDS of reservoir inflow, CI1 of equation (9). Because of the excessive sediment carried by the Powder River, the proposed dam at Moorhead was assumed to provide 875,000 af of inactive storage capacity in which to store incoming sediment. Theoretically, at the end of the economic life of the reservoir, this space would be filled with sediment, leaving only 275,000 af of a total storage capacity of 1,150,000 af for use (USBR 1969). Because water quality calculations are based on complete mixing of incoming flow with reservoir contents, VRo, the storage in the reservoir, could become an important parameter of equation (8). Therefore, water quality was simulated separately using both the initial 1,150,000 af and the final 275,000 af storage capacities. Results, illustrated in figures 22 and 23, indicate that TDS is relatively insensitive to the storage capacity. Consequently, the discussion that follows considers only the case of 1,150,000 af active storage, which would be more indicative of the early life of the structure. Only two levels of development, labeled low and high, were considered for the Powder Subbasin. Results are presented in tables 150 and 151 and in figures 24 and 25, and are briefly summarized below. Low Level of Development. A large dam at Moorhead would lessen the natural variation in TDS immediately below the dam, as indicated in figure 22, and pro- duce a nearly constant concentration of approximately 1100 mg/1. Subsequent use of reservoir releases for· irrigation, however, would significantly increase TDS concentrations at the mouth of the Powder River. Annual concentrations would increase 18 percent (25 percent with salt pickup of 1 ton per acre per year) and 97 percent (129 percent with salt pickup) at the 50th percentile and 90th percentile flows, respectively, from 1137 mg/1 to 1339 mg/1 (1423 mg/1 ~3 TABLE 149. Regression equations between TDS and monthly discharge (Q) in the Powder River near Locate, 1951-1963. Month Best Fit Equation 2 Significance r Jan TDS = 2009.9 - . 04002 Q .154 a Feb TDS = 3965.75 -663.84961 log Q .745 b Mar log TDS = 3.14148-.0000027288 Q .863 b Apr TDS = 1603.99-.00769 Q .764 b May TDS = 2952.2 -408.35 1 og Q . 179 a June log TDS = 3.50657 - . 102 53 log Q .256 a July TDS = 4378.26 -707.0542 log Q .579 b Aug TDS = 2171.01 -136.38783 log Q .067 a Sept log TDS = 3.35371 -0.06055 log Q . 170 a Oct TDS = 3479.57 -521.59961 log Q . 517 b Nov log TDS = 3.37988 -.00002 Q .856 b Dec log TDS = 3.40523 -.00002 Q .759 b All months TDS = 3348.9 -469.92334 .457 b NOTE: TDS represents average monthly figures in mg/1; Q represents monthly discharge in acre-feet. aNot significant at 4 percent level. bSignificant at 1 percent level. with salt pickup) and from 1390 mg/1 to 2739 mg/1 (3188 mg/1 with salt pickup). Monthly increases would be more dramatic. July through January values would increase by factors ranging from 1.69 (2.07 with salt pickup) to 2.46 (3.05 with salt pickup) at 50th percentile flows, or from an average 7-month concentration of 1552 mg/1 to 3221 mg/1 (3956 mg/1 with salt pickup). February through June increases would be comparatively modest at 50th percentile flows, but at 90th percentile flows, all months would show high TDS waters; over ten months of the year (June-March) TDS concentrations would exceed 3400 mg/1 (4100 mg/1 with salt pickup). During many months (even in average years), the Powder River at its mouth would consist almost entirely of irrigation return flow and would have TDS concentrations exceeding 3000 mg/1. Obviously such water would not be suitable for most beneficial uses. 344 ' 1700 1600 1500 1400 1300 1200 1100 ::::: "' 1000 E ~ "' 0 900 f- >. .t::. -c:: 800 0 :::;: ., "' 0 700 ~ ., > ct 600 500 400 300 200 100 ~-----11 ll·················ll ... ____ ..... •················• Oct Nov Jan Level of Development High High Low Low Historical Mixing Storage (of) 1,150,000 275,000 1,150,000 275,000 May June July Aug Sept Figure 22. Effects of reservoir storage on TDS concentrations in the Powder River near Moorhead. 345 5100 4800 4500 4200 3goo 3600 3300 ~ :;::: "' 3000 .§. en 0 2700 1- :?:-.c -c: 2400 0 :::E ., "' 2100 0 ~ ., > <l 1800 1500 1200 goo 600 300 0 !\ ... .... /J{\ ! I I ' j I I \ j I I ·, : I I ·. ! I I '. f I I : ! I I ' ! I I '· J::l.···········ti···········J::I.··········Il············l:l············ll······ f I I h-········tl·········-ll··········tl ·····'Jll I I I tl----tt----tl----tl----ll---I I Jl----tl----tl -!l----ll .\. --p:-- ·----·----•············ ............. ~, ...... . .... . .... , .,., \: 1: \~ 1\ 1: 1: ,: ~ ~ ~ ~ i t ~ t \ t \ f"" j l f j 1 I I I I I 1 ~~-f ...... ......... ~ ''=.::,::-..... ·.:.. _.-•r:::::. ::.-:::::::: ·----· tl'(. ······••·••·• / Level of Percentile Mixing Storage Development Values (of) n------Il High goth 1,150,000 tl········ .... ······tl High goth 275,000 ~------Low 5oth 1,150,000 •················• Low soth 275,000 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Figure 23. Effects of active storage level on average monthly TDS concentrations in the Powder River near Locate. 346 C...r: .· TABLE 150. TDS values in the Powder River, assuming a low level of development with 1,150,000 af storage. 50th Percentile.Values 90th Percentile Values Simulated ' Simulated Historical· TDS at Historical TDS at a Q TDS Q Salt pickupa of: Q TDS Q Salt pickup of: 0 .. 1 0 .. 1 (a f) (mg/l) (a f) (mg/l) (mg/ 1 ) (mg/l) (a f) (mg/l) (a f) (mg/l) (mg/l) (mg/l) OcJ: 7 '192 1,468 2,000 3,267 4,003 553 2,049 2,000 3,511 4,246 Nov 10,351 1 ,475 1,250 3,267 4,002 3,688 2,017 1 ,250 3 '511 4,246 Dec 7,069 1 '929 1 ,000 3,267 4,002 3,750 2,196 1 ,000 3,511 4,246 Jan 6,393 1 '754 750 3' 121 3,856 1 ,967 1 '931 750 3,511 4,246 Feb 11 '160 1 ,279 3,312 1 ,320 1 ,431 3,565 1,608 500 3,511 4,246 March 53,543 989 34,922 1 '163 1 '178 17,889 1 ,238 750 3,472 4,208 Apri 1 34,266 1 ,340 30,600 1 '192 1 ,216 20,643 1 ,445 2,315 2,059 2,376 May 63,747 990 51,484 1 '189 1 ,200 26,065 1 '149 14,066 1,704 1 '743 June 100,360 986 91 ,303 1,204 1 ,256 10,946 1 ,237 3,500 3,439 4 '174 July 27,601 1 ,238 4,500 3,041 3,776 2,889 1 ,931 4,500 3,511 4,246 Aug 9,221 1 ,637 4,500 3,292 4,027 861 1 '771 4,500 3,511 4,246 Sept 4,164 1,363 2,500 3,292 4,027 . 535 1 ,544 2,500 3,511 4,246 Jlnnua 1 335,067 1 '137 228,121 1,339 1 ,423 93,331 1 ,390 37 ,631 2,739 3 '188 aSalt pickup given in tons per acre per year. TABLE 151. TDS values in the Powder· River at Locate, assuming a high level of development with 1,150,000 af storage. 50th Percentile Values 90th Percentile Values Simulated Simulated Hi stori ca 1 TDS at a Historical TDS at Q TDS Q Salt pickup of: Q TDS Q Sa 1t pi ckupa 0 ~ 1 0 ~ (a f) (mg/1) (a f) (mg/1) (mg/1) (mg/1) (a f) (mg/1) (a f) (mg/1) (mg/1) Oct 7,192 1 ,468 3,000 3,504 4,320 553 2,049 3,000 3,699 Nov 10.351 1 ,475 1,880 3,467 4,281 3,688 2,017 1,880 3,692 Dec 7,069 1,929 1 ,500 3,476 4,290 3,750 2,196 1,500 3,702 Jan 6,393 1 , 754 1 , 130 3,460 4,274 1 , 967 1 ,931 1 '130 3,685 Feb 11 '160 1 ,279 750 3,462 .4 ,276 3,565 1,608 750 3,702 March 53,543 989 3,054 1 ,953 2,254 17,889 1,238 1 ; 130 3,644 April 34,266 1 ,340 22,028 1 ,312 1 ,367 20,643 1 ,445 1,500 3,660 May 63,747 990 33,507 1 ,464 1 ,492 26,065 1 '149 4,040 4,639 June 100,360 986 66,765 1,200 1,265 10,946 1,237 5,260 3,604 July 27,601 1,238 6,760 3,433 4,249 2,889 1 '931 6,760 3,694 Aug 9,221 1 ,637 6,760 3,499 4,315 861 1 '771 6,760 3,694 Sept 4,164 1 '363 3,760 3,498 4,312 535 1 ,544 3,760 3,693 • fmual 335,067 1 '137 150,894 1 ,675 1,862 93,331 1 ,390 37,470 3,781 aSalt pickup given in tons per acre per year. of: 1 (mg/1) 4,515 4,506 4,516 4,499 4,515 4,457 4,474 4,867 4,419 4,510 4,510 4,506 4,532 5100 4800 4500 4200 3900 r 3600 3300 ...... "' 3000 ..s rn c 2700 I- J!::o .c:; -c: 2400 0 :::;: ., "' 2100 0 ~ ., > ~ 1800 1500 1200 900 600 300 n------n n .............. u ·-----~ •··············• Level of Development High High Low Low Historical Soli Pickup ( tons/ocre/yeor) I 0 I 0 NOTE: 501h Percentile Values 1,150,000 af Storage n--n ~ -"-ll---~----!l----"1 'il-------~ ·----.-----...... ........ '~ I I I I I I I I ,.----• I I / I I ,, I I •/ I I I I 1 I \ If .n·········-n I I ;n··········· I I : ll···········n···········O············n·\··········~ . I \ I I : I I I! .············• ············•············ \ ···· .....• I Oct Nov Dec \ I \ I '· I ~ I : I ~ I : I ~ I : I :1 : I :1 ·:I :I ":1 '.\ " ~ • . , . I I 1 : .·· :. I I' _.. II.:• .. : I \ I 1,:: : I l(i : I /iif : 1 Iff; : I 1/ii \ I II:; : I l(f \ \ IIi: ·.n ll'i \\ 10 : I IF' ·, 1 u!! 1:1 1 11:: "-. I 1/f \ I 11; · .. I llf \1 ~ ·. I 1/: ·· .. I ~:fl... "' ., ·.1 ~-: ...... ,.. 1 . ~ .... ~ .... ":~~ ····-~-~-~..-=---=- Jon Feb Mar Apr Moy June July Aug Sept Figure 24. Average monthly TDS concentrations in the Powder River near Locate at 50th percentile values with 1,150,000 af storage. 349 5100 4800 4500 4200 3900 3600 3300 ~ ;;::: ~ 3000 - (/) 0 2700 1- :!:::-.c; -c 2400 0 ::E .. "' 2100 0 ~ .. > <t 1800 1500 1200 900 600 300 0 l"f\ I \ \ I tl \ I .. \ I ', n----n----l:l----!::1----l:l--J i · ' _.ll----ll----n --n----"' . 'l:t--- ·--------·----·----------tit .----.. ----·----· I I I I I . I I ·. I I '1 I : Jl ........... Jl. .......... Jl ........... a, ......... n ........... ~ .. 1 ...... !:i r-. n ......... n----·····-n -I : tx·····"" ............................................................... \ \ I ,. ................................ . . I I i Jl-----.Jl ll"""""""Jl ·-----.. •··············• NOTE: 90th Oct Nov Dec Jon '· I I : ·, I I i Level ; I I i \ I /i : I . :. I I : :_ I I ; ·.. I I ; of ; I I ; ': I I ; ':_ 1 I; : I I i ; I /' : I If \ \ li •·· .. \ " ·.. \ li ·· .. \ f ·--~ Salt Pickup Development (tons/acre/year) High I High 0 Low I Low 0 Historical Percentile Values 1,150,000 of Storage Feb Mar Apr May June July Aug Sept Figure 25. Average monthly TDS concentrations in the Powder River at Locate at 90th percentile values with 1,150,000 af storage. 350 -, High Level of Development. Annual TDS concentrations would increase 47 percent (64 percent with salt pickup of 1 ton per acre per year) and 172 per- cent (226 percent with salt pickup) at 50th percentile and 90th percentile flows, respectively. Concentrations would be about doubled--to 3600 mg/1 (4500 mg/1 with salt pickup) or more--for all months under 90th percentile flows. At 50th percentile flows, TDS concentrations would average about 3500 mg/1 (4300 mg/1 with salt pickup) from July through February, or approximately 2.3 (2.8) times natural levels; factor increases would be 1.97 (2.27 with salt pickup) for ~larch, 0.98 (1.02 with salt pickup) for April, 1.48 (1.51 with salt pickup) for May, and 1.22 (1.28 with salt pickup) for June. Flows at the mouth of the Powder River would consist essentially of irrigation return flows which would be unsuitable for most beneficial uses. Depending upon the location of new irrigated land, soil properties, and the type of irrigation system used, the water may become unsuitable for irrigation before it reaches the mouth of the river. In fact, water released from the dam would be classified as high salinity water and could not be used on soils with restricted drainage; according to Richards (1954), " ... even with adequate drainage, special management for salinity control may be required and plants with good salt tolerance should be selected." Obviously, before any land in the Powder River Valley is brought under irrigation, a thorough investigation should be undertaken to determine the compatibility of crop, soil, and water. Other Parameters Powder River water is characterized by high TSS as well as high TDS concen- trations. Dissolved constituents consist primarily of sodium and sulfate ions, with lesser, but significant, concentrations of calcium, bicarbonate, and chloride. SAR values sometimes exceed 5 or 6, but generally range from 3-4. Construction of a large reservoir would tend to stabilize the concentrations of all dissolved minerals and the value of SAR (assuming no significant dissolution or precipitation of minerals within the reservoir). Moreover, incoming sediment would be trapped behind the dam. Based on historical records, and assuming com- plete mixing within the reservoir, releases from the dam should have approximat- ely the concentrations listed in table 152. TABLE 152. Concentrations of dissolved minerals and SAR value that would be released from a reservoir constructed on the Powder River, based upon historical records. TDS Na 504 HC03 Hardness SAR Concentrations 1125 mg/1 159 mg/1 572 mg/1 209 mg/1 486 mg/1 3.13 Such water would be undesirable for most beneficial uses. It would be suitable for irrigation only for salt resistant crops on well-drained soils. The high 351 levels of TDS, S04, and hardness preclude its use for domestic purposes unless no better source 1s available. The significant increases in TDS that would result from using reservoir releases for irrigation would be accompanied by corresponding increases in the dissolved constituents. The mix of ions may be altered somewhat, depending upon chemical properties of the soils irrigated. The net result, in any case, would be further contamination. By the time it enters the Yellowstone, Powder River water would contain excessive concentrations of several minerals, and would be unuseable for almost all beneficial purposes. Containment of flood waters, with their enormous sediment loads, behind the dam would reduce the sediment concentration in water released from the reser- voir. The Powder River channel is highly erodible, and it is likely that con- siderable scouring would occur below the dam. For a given discharge, the river may eventually carry as much sediment after construction of the dam as it did before. Because the dam would store floodwaters and release a more uniform flow downstream, however, the total annual sediment load discharged into the Yellow- stone River should be reduced by construction of the dam. In an average year, under both levels of development, discharges would be reduced 10 percent to 85 percent during the July-to-September period. The result could be an increase in water temperature, a decrease in dissolved oxygen, and an increase in the diurnal variation of both. At 90th percentile flows, on the other hand, discharges would be higher than under natural conditions. Therefore, water temperatures and dissolved oxygen levels may increase. The key factor would be the effect of the large reservoir on water quality below the dam. The quality of releases would depend on many factors, including the nature of chemi- cal and physical changes that may occur during storage, biological activity in the reservoir, and the depth at which water is withdrawn--factors that are dif- ficult to quantify before construction and operation of the prototype. Summary Powder River water naturally contains relatively high concentrations of both TDS and TSS. Construction of a large dam at Moorhead would reduce the sediment load in the river below the dam and tend to stabilize the concentration of TDS at approximately 1100 mg/1, which would classify the water as having a high salinity hazard. Subsequent use of such water for irrigation would in- crease TDS concentrations by factors of 2 to 3 before the water would reach the Yellowstone River. The low flows (which would often consist essentially of irrigation return flows) and high TDS levels would be accompanied by higher SAR values and in- creased hardness, plus higher concentrations of all dissolved minerals. Many of these parameters, such as sodium, sulfate, and hardness, are already excessive (the sulfate standard is 250 mg/1, and water is hard at 100 mg/1; typical concentrations in the Powder River are 400-700 mg/1 sulfates and 300- 600 mg/1 hardness). Moreover, dissolved oxygen levels may be depressed and water temperatures elevated under either level of development, thereby greatly 352 J stressing the aquatic environment. Obviously, any proposed developments on the Powder River should be carefully and thoroughly scrutinized to determine their economic feasibility and environmental desirability. LOWER YELLOWSTONE SUBBASIN Total Dissolved Solids Nineteen years of records (1951-1969) on the Yellowstone River near Sidney were used to develop the regression equations between TDS and discharge given in table 153. Three levels of development were analyzed, each for an assumed salt pickup of 0 and 1 ton per acre per year. Results are presented in tables 154, 155, and 156, and are illustrated graphically in figures 26 and 27. Each level of development is discussed below. Low Level of Development. Realization of the low level of development would cause a moderate increase in TDS concentrations in the Yellowstone River at Sidney. Average annual increases in TDS would be from 422 to 434 mg/1 (445 mg/1 with salt pickup of 1 ton per acre per year) at 50th percentile flows and from 486 to 515 mg/1 (524 mg/1 with salt pickup) at 90th percentile flows. Individ- ual monthly increases generally would be less than 15 percent. Notable exceptions would be July and August at 90th percentile flows, when increases would be 20 percent (23 percent with salt pickup) and 31 percent (38 percent with salt pickup), respectively. The August concentration would increase from 542 to 709 mg/1 (748 mg/1 with salt pickup). Intermediate Level of Development. Average annual increases in TDS would range from 9.5 percent at 50th percentile flows~with 0 salt pickup to 15.2 per- cent at 90th percentile flows with 1 ton per acre per year salt pickup. At 50th percentile values, only March, August, and September would show major in- creases in salinity: 24 percent (26 percent with salt pickup of 1 ton per acre per year), 28 percent (47 percent with salt pickup), and 18 percent (21 percent with salt pickup). Increases would be more severe at 90th percentile flows. Percentage increases from July through October would be 37 (45 with salt pickup), 68 (83 with salt pickup), 17 (27 with salt pickup), and 10 (13 with salt pickup). Actual concentrations would average 691 mg/1 (701 mg/1 with salt pickup) from August through October at 90th percentile flow levels. High Level of Development. If the development assumed by this projection were to occur, the lower Yellowstone Subbasin would show a major increase in TDS concentrations, especially during July, August, and September. Annual con- centrations would increase from 422 to 459 mg/1 {477 mg/1 with salt pickup of 1 ton per acre per year) at 50th percentile flows and from 486 to 541 mg/1 (586 mg/1 with salt pickup) at 90th percentile flows. July, August, and September concentrations, however, would increase by 24 percent (36 percent with salt pickup), 41 percent (52 percent with salt pickup), and 24 percent (29 percent with salt pickup) at 50th percentile flows; and by 38 percent (60 percent with salt pickup), 108 percent (168 percent with salt pickup), and 30 percent (55 percent with salt pickup) at 90th percentile flows. August through October concentrations would average 637 mg/1 (670 mg/1 with salt pickup) at 50th percentile flows and 881 mg/1 (1052 mg/1 with salt pickup) at 90th percentile 353 flows. Thus, even in average flow years, river water would have a high salinity hazard (Richards 1954) after July and during April. TABLE 153. Regression equations between TDS and monthly discharge in the Yellowstone River near Sidney, 1951-1969. Month Best Fit Equation 2 Significance r Jan log TDS = 4.45663 -.2983 log Q .655 a Feb TDS = 2469.44 -339.72412 log Q .580 a Mar TDS = 2785.62 -392.1665 log Q .571 a Apr 1 og TDS = 2.864506 -.0000001684 Q .634 a May TDS = 561.71 -0.00017959 Q .494 a June TDS = 198.98 + 0.00003539 Q .247 b July TDS = 917.41 -101.69664 log Q .250 b Aug TDS = 2303.31 -327.66333 log Q .602 a Sept 1 og TDS = 2.85842 -.0000002973 Q . 543 a Oct TDS = 3745.50 -561.71338 log Q .722 a Nov TDS = 3852.08 -579.99414 log Q .629 a Dec TDS = 863.67 -.00061612 Q .446 a All months TDS = 2827.38 -403.47119 log Q .685 a NOTE: TDS represents average"monthly concentrations in mg/1; Q represents monthly discharge in acre-feet. aSignificant at 1 percent level. bSignificant at 5 percent level. Other Parameters Significant reductions in flow and major increases in TDS would result in concomitant degradation of water quality as measured by various parameters. Unfortunately, techniques are not currently available to determine the magnitude of changes in most parameters. ~1ost dissolved constituents vary fairly 1 inearly with TDS concentrations. The plot for sulfate (S04) is shown on figure 28. A 20 percent increase in TDS, from 500 mg/1 to 600 mg/1, would increase so 4 from _ 354 w (J"I (J"I .. TABLE 154. TDS values in the lower Yellowstone River near Sidney, assuming a low level of development. 50th Percentile Values 90th Percentile Values Simulated Simulated His tori ca 1 TDS at Historical TDS at Q TDS Q Salt pickupa of: Q TDS Q Sa 1t pi ckupa 0 lo 1 0 J.o (a f) (mg/1) (a f) (mg/1) (mg/l) (mg/1) (a f) (mg/l) (a f) (mg/l) (mg/l) Oct 489,571 549 453,165 580 585 338,778 639 305,608 680 Nov 441 ,416 578 441,005 580 587 340,461 644 340,600 647 Dec 360,109 642 350,824 642 651 243,249 714 234,670 718 Jan 327,344 648 316,982 650 662 200,095 750 201,851 743 Feb 340,096 590 338,537 587 597 256,410 632 249,182 630 March 635,385 510 612,714 514 • 518 343,573 615 304,539 633 April 547,605 592 538,938 582 586 345,280 640 388,858 621 May 1,139,647 357 1,037,764 349 391 569,424 459 480,471 496 June 2 ,321 ,298 281 2,217,202 283 285 1 ,217,402 242 1,123,425 250 July 1 ,244,331 298 1,085,901 336 342 532,541 335 393,007 403 Aug 446,355 452 353,761 516 537 237.778 542 138,179 709 Sept 431 ,778 537 326,062 599 609 218,388 622 174,059 685 l'mual 8,724,936 422 8,072,855 435 445 4,843,379 486 4,335,349 515 aSalt pickup given in tons per acre per year. of: 1 (mg/1) 690 657 732 760 643 641 627 501 254 412 748 704 524 TABLE 155. TDS values in the lower Yello~stone River near Sidney, assuming an intermediate level of deve 1 opment. 50th Percentile Values 90th Percentile Values Simulated Simulated Historical TDS at a Historical TDS at Q TDS Q Salt pickup of: Q TDS Q Salt pickupa of: 0 !-, 1 0 !-, 1 (a f) (mg/1) (a f) (mg/1) (mg/1) (mg/1) (a f) (mg/1) (a f) (mg/1) (mg/1) (mg/1) Oct 489 ,571 549 450,778 598 610 338,778 639 305,093 705 722 Nov 441 ,416 578 422,969 597 614 340,461 644 337,869 654 674 Dec 360,109 642 339,545 655 677 243,249 714 231,366 718 751 Jan 327,344 648 310,589 648 677 200,095 750 198,777 735 780 Feb 340,096 590 329,219 584 610 256,410 632 246,089 623 656 March 635,385 510 592,839 633 643 343,573 615 294,179 647 666 April 547,605 592 513,823 602 611 345,280 640 363,422 647 661 May 1,139,647 357 1 ,001 ,548 403 407 569,424 459 440,103 532 543 June 2,321,298 281 2,155,473 287 291 1 ,217,402 242 1 '101 ,047 265 273 July 1 ,244,331 298 1 ,049 ,411 356 364 532,541 335 358,134 459 486 Aug 446,355 452 325,254 579 663 237 '778 542 109,601 910 994 Sept 431 '778 537 309,139 634 651 218,388 622 160,003 725 790 A111ua 1 8,724,936 422 7,800,587 462 475 4,843,379 486 4,145,683 539 560 aSalt pickup given in tons per acre per year. - TABLE 156. TDS values in the lower Yellowstone River near Sidney, assuming a high level of development. 50th Percentile Values 90th Percentile Values Simulated Simulated His tori ca 1 TDS at a Historical TDS at a Q TDS Q Salt pickup of: Q TDS Q Salt pickup of: 0 lo 1 0 lo 1 (a f) (mg/1) (a f) (mg/1) (mg/1) (mg/l) (a f) (mg/1) (a f) (mg/1) (mg/l) (mg/l) Oct 489,571 549 437,762 610 627 338,778 639 294,921 706 745 Nov 441 ,416 578 410,592 605 626 340,461 644 325,594 663 689 Dec 360,109 642 325.177 663 691 243,249 714 217,052 723 771 Jan 327,344 648 295,093 656 691 200,095 750 183,233 748 805 Feb 340,096 590 313,099 589 620 256,410 632 232,731 629 669 March 635,385 510 574,039 523 535 343,573 615 279,314 651 679 April 547,605 592 496,380 606 619 345,280 640 346,372 649 673 May 1 ,139 ,647 357 953,657 399 406 569,424 459 387,996 529 576 June 2,321,298 281 2,091 ,091 288 292 1 ,217,402 242 1 ,051 ,323 261 283 July 1 ,244. 331 298 961 ,489 368 405 532,541 335 324,521 463 537 Aug 446,355 452 279,027 638 688 237.778 542 76,264 1 , 127 1 ,450 Sept 431 , 778 537 266,401 663 694 218,388 622 98,503 809 961 Jlnnua 1 8,724,936 422 7,403,807 459 477 4,843,379 486 3,817,824 541 586 aSalt pickup given in tons per acre per year. 1500 1400 1300 1200 1100 1000 ~ ' "' 900 E - (/) 0 800 1- ,.., :.: -700 c 0 :::E ., "' 600 0 ~ ., > "' 500 400 300 200 100 0 Oct Nov Level of Development High High Intermediate Historical NOTE: 501h Percentile Values Feb Mar Apr Salt Pickup (tons /acre/year) I 0 0 r-·---·· . ········• '······ . .... . /.' ..... . ..... ,._ .... , .... . .'I .'-... , -'it .lit I it .J...-i /..., .. ·f / .. -;, /.·-/ .. ,. May June Sept Figure 26. Comparison"of historical and simulated TDS concentra- tions in the Yellowstone River near Sidney at 50th percentile flow values. 358 1500 1400 1300 1200 " \ 1100 1000 ..... "' 900 E ~ en 0 800 ~ ~ .t:: c 700 0 ::;: "' "' 600 0 ~ "' > < 500 400 300 200 100 NOTE: 901h Level of Development High High Intermediate Historical Percentile Values Salt Pickup (tons /acre/year) I 0 0 ~ I i ; i I I I I I I I I I I I I !' ; f\ \ I I \ I : i j ~ ! j I\ I ! I ' I I ~ . , I ' . --• ! ; I \ • /.-\ I j I \ • ... , / -"\ 1ft ~ e.... ·. ·-.. .•. /_,._,. " ' . ' I Oct ....._'-;,;,;, .. --~ \!~ ·'..----.... -·-·-•-! ! I .. -~·~ .. ---'·, IiI Nov Dec Feb Mar ' . l"jl \>-. ·il '\..'-,_ h ' f!l " f.'J \. . .1 ,, /I \\ It \\ i I \" . I \\ /I \1 y May June July Aug Figure 27. Comparison of historical and simulated TDS concentra- tions in the Yellowstone River near Sidney at 90th percentile flow values. 359 400 • -300 • • ...... • • "' •• E -• • • c • • 0 • -• • • 0 ·-~ -.... c CD •• • .., c 200 • • • 0 u • "' --0 w -• m :::1 • o (/) • •• ..,. • • 0 ., 1/) 100 • • • • 0 0 100 200 300 400 500 600 700 TDS: Total Dissolved Solids (me;~ II) Figure 28. Comparison of S04 ~nd TDS concentrations in the Yellowstone River near Sidney. 215 mg/1 to 275 mg/1 (approximately). The so 4 water quality standard of 250 mg/1 is exceeded in five months of the year under historical (considered natural by Montana law) conditions during a 50th percentile flow year. This frequency of standard violation would increase to seven months per year under the low level of development and to eight months under the intermediate and high levels of development. Hardness would increase in proportion to higher TDS levels. In the Yellow- stone River near Sidney, a 100 mg/1 increase in TDS increases hardness by approx- imately 45 units. An increase in TDS from 500 to 600 mg/1 would therefore result in a hardness of 290 mg/1. Although no legal standards have been adopted for hardness, anything over 100 mg/1 becomes increasingly inconvenient for domes- tic use and some industrial applications. Nutrient concentrations may increase because of fertilizer applications to new irrigation lands and because less water would be in the stream for dilution. Water temperatures would be somewhat higher because of .reduced streamflows, but probably not more than Y,CC. The river's waste assimilation capacity would be diminished. Dissolved oxygen levels may be reduced and diurnal variations would increase, primarily in late summer of low-flow years (Knudson and Swanson 1976). Summary The low level of development would have minor impacts on the overall water quality of the Yellowstone River near Sidney--only August and September of dry years would show significant increases in TDS. The high level of development, however, would cause a major reduction in water quality, especially during July, August, September, and October. During this four-month period, 50th percentile level discharges would be reduced more than 25 percent (38 percent during August and September) and 90th percentile level discharges would be reduced more than 40 percent (65 percent during August and September). Flow reductions of such magnitude would be accompanied by major increases in salinity, especially during the latter part of the irrigation season. Furthermore, nutrient levels pro- bably would increase; water temperature and its diurnal range may increase, and dissolved oxygen and suspended sediment concentrations may decrease. The net effect would be a deterioration of water quality and the aquatic environment. The water would be suitable for most beneficial uses most of the time. Municipal and industrial users may sustain higher treatment costs (al- though a reduction in TSS, if it were to occur, could reduce treatment costs) or more inconvenience (scaling, for example). Irrigators may encounter more salinity and drainage problems, reduced yields, or the necessity of more con- trolled management of their irrigation practices. The aquatic environment would suffer stresses because of the reductions in flow and degradation of water quality. 361 SENSITIVITY ANALYSES INTRODUCTION The methodology described in previous sections should not be considered infallible, but rather a "first generation" attempt to evaluate the flow of water and salt through the Yellowstone River Basin. There are several areas in which improvement could be made. Unfortunately, most such improvements are dependent upon data which have not been collected and field studies that have not been performed. Hence, there is an element of the unknown in several of the assumptions used. One unknown, total salt pickup by irrigation return flows, was acknowledged in the model through the use of two levels of salt pickup in most subbasins; that is, zero and one ton per acre per year. The actual salt pickup probably varies over a wide range of values throughout the basin. Also unknown is the distribution of return flows and the concentration of salts in return flow, both of which probably show considerably spatial and temporal variation. DISTRIBUTION OF SALT RETURN In the model irrigation return flows both salt and water were distributed according to the monthly percentages discussed previously in the explanation of table 20. In effect, irrigation return flow was assumed to have the same TDS concentration each month of the year. To test the sensitivity of the model a different distribution of salts was used, based on the following assumptions: 1) Return flow (water) is distributed according to the original assumption; i.e., beginning in April, each month's percentage of the total annual return flow is as follows: 4, 11, 14, lB, 18, 10, 8, 5, 4, "3, 2, 3. 2) Fifty percent of salt is returned during the October-to-March period, when flow is essentially all subsurface. 3) Fifty percent of salt is returned during the April-to-September period. 4) The resulting percentages of salt returned each month are as follows, beginning with April : 2 . 7 , 7. 3 , 9 . 3 , 12. 0, 12 . 0, 6. 7 , 16 . 0 , 1 0. 0, 8.0, 6.0, 4.0, 6.0. This is the ''adjusted'' salt distribution. The above distribution reflects the concept that subsurface return flow which predominates during the nonirrigation season, is higher in dissolved solids than surface return flow, which is assumed to dominate during the irrigation season. Comparisons were made of simulated stream TDS values in both the Tongue River and lower Yellowstone subbasins. Results are discussed below. Tongue River Subbasin The Tongue River was selected for analysis because the original simulations indicated that TDS would be increased substantially by further development. Use of the adjusted salt return distribution did not alter the basic conclusion. Figures 29 and 30 indicate that, as expected, the adjusted distribution simply 31\2 1700 160.0 1500 1400 1300. 1200 1100 ::::: "' 1000 E - (/) c 1-900 ,.. -~ c 800 0 ::E .... r Cl' c 700 ~ ., > <[ 600 500 400 300 200 100 ' ,.--.. . . . . '~ ~ ' ' ' j \ \ ' \ \ ' \ ' \ \ . • ' • • • ' ' • ' •, ' \' ' --"" . ' / ' ~ \. v"' .. ~ . .•.. . . . . . · ... .. .;_._ : ... ··' '. _. -.-s:· ) ', -. ' Oct Nov Level of Development Intermediate· · Intermediate· - · Historical -No .• Salt Return Distribution Adjusted Original-- New Diversions ._. i·· .. :. .. . . . . . . . . . . . . . . : . . . . . .. . . .. :: .-. . . ·. : \ . \ : . • " :-. . . . ,. ! I ' : 1 ' . : ' -~-: 1. ·:/ I I I I l ·I· i Aug Sept Figure. 29. -.Effect' on TDS concentrations of changing the-monthly distribution of salt return from irrigation in· the TonguE! River near Miles City, using the intermediate 'level of develop!llent. 363 ·r ,._. '<· :r. ._., ::::: "' .s (/) 0 1- ~ .<= -c 0 ::E ., "' 0 ~ ., > <( 1700 1600 I I 1500 I \ 1400 \ \ I 1300 \ \ 1200 \ \ \ 1100 \ \ 1000 \ \ 900 \ \ \ 800 0 \ ·. 0 ,,.. 700 0 .... 600 500 400 300 200 100 ----- 0 •••••• 0 •••••••• ---, ,. \ / ......... ···. .. 0 0 0 Level of Development High High Historical -No Salt Return Distribution Adjusted Original New Diversions 0 0 0 0 0 : ...... ··-: ~ 0 ~--,---,----.---r---r---r---r---r---r---.---.~-, Jan Feb Mar Apr May June July Aug Sept Oct Nov Figure 30. Effects on TDS concentrations of changing the monthly distribution of salt return from irrigation in the Tongue River near Miles City, using the high level of development. 364 shifts the highest simulated TDS values from July and August to October. Such a shift, if it occurred in practice, would lessen the impacts of increased salinity on irrigation because stream TDS would be less during the late irri- gation season. Concentrations would still be significantly higher than under natural conditions. Moreover, the maximum concentrations would increase, though in October instead of August. Lower Yellowstone Subbasin The same change in stream salinity was evident in the lower Yellowstone Subbasin as in the Tongue--TDS levels would be reduced in late summer and in- creased during the fall and winter (figures 31 and 32}. A shift of this nature could be beneficial to irrigators. It must be emphasized, however, that the adjusted salt return distribution probably underestimates the salt load return- ing to the stream in late summer. Water temperature data from the Lower Yellow- stone Project, for example, indicate that substantial subsurface return flows may re-enter the river during the July-August period. During May, June, and the first half of July, temperatures in the main canal drain were higher than temperatures of the diverted water; from about July 15 until September 15 the reverse was true--the drainage water was lower in temperature than the diverted water (figure 33). A logical explanation is that during the early part of the irrigation season, drainage water consisted primarily of surface irrigation retirn flows which had increased in temperature during the irrigation cycle; after mid-July the drainage canal recovered significant inputs of subsurface irrigation return flows which tend to be cooler than surface flows. Hence, drainage water containing subsurface return flows would be cooler than diverted river water. Subsurface return flows from irrigation also are generally higher in salinity than surface returns. Thus it is conceivable that June, July~ and September flows would have higher salt loads than originally assumed. The conclusion remains the same: additional irrigation development of the magnitude envisioned under the intermediate and high levels of development, would increase TDS concentrations significantly and to the detriment of current irrigators. SALT PICKUP The analyses for each subbasin included two levels of salt pickup, zero and one ton per acre per year. Generally, the graphs of TDS for each subbasin contained a plot of the high level of development values for both levels of salt pickup. In some instances, the intermediate level of development with one ton per acre per year salt pickup would have a more severe impact than the high level of development with zero salt pickup. In the lower Yellowstone, for example, the average TDS would be 459 mg/1 for the high level of development with zero salt pickup, but 475 mg/1 for the intermediate level of development with one ton per acre per year salt pickup. Thus, the leaching of salts by irrigation return flows can have significant impacts on stream salinity. Figures 34 and 35 illustrate the importance of salt pickup on the Tongue River and the lower Yellowstone. Obviously, as irrigation return flows comprise a larger portion of total streamflow, the rate of salt accretion assumes more importance. 365 ..... "' E ~ en 0 1-... ~ -c: 0 ::::E .. "' D ~ .. > <( 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 Level of Development Intermediate I ntermed ia te Historical -No Salt Return Distribution Adjusted Original New Diversions 0~--~--~r---~--,----r--~--~r---~--,---~--~--~ Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Figure 31. Effects on TDS levels of adjusting the monthly distrib- ution of salt return from irrigation in the Yellowstone River near Sid- ney, using the intermediate level of development. 366 l ' J ..... "' E IJ) 0 1- .?:- .<:: -c 0 ::!! ., "' 0 ~ ., > <! 1700 1600 1500 1400 1300 1200 1100 1000 900 BOO 700 600 500 400 300 200 100 Level of Development High High Historical -No New Salt Return Distribution Adjusted Original Diversions .·. : · .. : · .. . ·. : · .. : · .. : ,--- : I j I ! I :1 ~······· · f I --······ ., --..::..·····'1 .... .., 0~---r---.----.---.---,----r---.----.---.---,----r---, Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Figure 32. Effects on TDS levels of adjusting the monthly distrib- ution of salt return from irrigation in the Yellowstone River near Sid- ney, using the high level of development. 367 u !... 28 26 24 ., 22 ~ :::1 0 ~ ., Cl. 20 E ~ ~ ., -0 ;t: 0 0 E :::1 18 16 E 14 " 0 ~ 12 10 Main Canol at Intake Main Canol Drain Near Cartwright '"I I I )I I ,\ I I I • ~ ~~'" !\ lv\1 \ I I I I I I ~ I I I 11 I 1 I i ~ I I I 1 1 I I 1 0 I I I t I I I I I I I \ I \ I I I ' I ' I I I I I I I I I I I I I I II II I ~ I I I I I I I I I I I I I I 5 June I I I fl I I I I 1 I I I I -I \ 1 I 1 ~ I I I I I " I II I 1 II I 1 ~ II ~ I' I I -I 1\ I o I I II I ~, I I I I I~ ! I ~I I vv~'~\~ I I I I I I ' I I ,' \ I I I \1 \I ~ I I I I I August September Figure 33. Water temperatures observed on the Lower Yellowstone Project, 1971. -- .· c 1700 1600 1500 1400 : 1300 . 1200 1100 ...... . "' 1000 E ~ (/) 0 • 1-900 >o .s:: --~. 800 :::10 "' "' 700 0 ~ "' > <( ·soo .r 500 400 300 200 100 ' : . '} J ............. ----- NOTE' . . ' '· 50'h ' . ~ ,l ~: ' I ' ' . ·; ~;' ·-~-"'~ -Level.~ of .· Developmef!t .. Intermediate lntermedio.te lntermed iot.e Percentile Values . -·-:;;-.-~"; ..,------- Salt Pickup (tons /acre /year) 2 I 0 "'r.. .• 0 -+---r---r---r"'"'---r-'--:':r'-'-~-...;o."'""'"T:----r------."--....,..,----.---, · ·· -. Oct Nov Dec Jon · ·Feb': Mcir; Apr: May June July· Aug Sept ' ·'· -· ... '·.'Figure· 34.: ·Effects ·of ·salt' pickup. rate on TDS concentrations in . '. .the' Yellowstone River near Sidney, using the intermediate. level of de- velopmenf at 50th percentile flows. · 369 3400 3200 3000 2800 2600 2400 2200 ' E' 2ooo ~ en 0 1800 1-,.. .c -" 1600 0 ::E Ql "' " 1400 ... Ql > <( 1200 1000 800 600 400 200 Level of Development Intermediate Salt Pickup (tons /acre/year) 2 -----Intermediate I Intermediate 0 NOTE: 501h Percentile Values ··· ... ·· .......... . .. ..... .._ ·· ... ---....... ·· .. ............... ·· .. -------'· .. ' ..... . .............. ·· ....... . -- .. ···~ :. . . ·. . . . I . . . . 04----r--~----r---~--~---r--~----r---~--~--~--~ Oct Nov Dec Jon Feb Mar Apr May June July Aug Sept Figure 35. Effects of salt pickup rate on TDS concentrations in the Tongue River near ~1iles City, using the intennediate level of development at 50th percentile flows. 370 EXOGENOUS INFLUENCES According to the assumptions of this study, the three dominant beneficial uses for which water will be diverted from streams in the basin over the next several years will be for irrigation, energy conversions, and municipal use. Consequently, water quality would be influenced primarily by these uses. There are other land and water uses, however, with the potential to diminish water quality, particularly in smaller streams or short reaches of larger streams. DRYLAND FARMING In eastern Montana, large tracts of rangeland are being converted to dry- land farming, principally for the production of wheat. Geissler {1976) quotes an agricultural official's estimate that 50,000 new acres were turned over to wheat farming in 1975 and 1976. Some of this land is very fragile, and increased erosion by both wind and water is likely. The EPA (1973) reports that average erosion rates are 15 to 20 times higher from cropland than from rangeland. Through increased erosion, cropland may also contribute sediment, salts, nutri- ents, pesticides, organic loads, and bacteria. Consequently, increased dryland farming ·may adversely affect the water quality of streams in the Yellowstone River Basin. SALINE SEEP Saline seep is a process in which surface water infiltrates the soil pro- file, encounters a saline layer from which salts are dissolved, and emerges downslope. This saline seep may pond below the point of emergence, killing the vegetation and leaving a deposit of white salt when the water evaporates, or it may enter a watercourse and increase stream salinity. Kaiser et al. (1975) estimate that more than 25,000 acres in the Yellowstone River Basin of Montana are affected by saline seep. Dryland farming aggravates this condition; unless different farming methods are adopted, saline seep is likely to become a greater problem. Saline seep also can be caused by brines from oil and gas drilling operations, and possibly by leaching from coal spoil banks--both activities are prevalent in eastern Montana. SILVICULTURE About 11.5 percent of the Yellowstone River's watershed in Montana is comprised of forests. For physical and economic reasons, only a limited amount of timber harvesting from these forests occurs at present, and production is unlikely to increase dramatically in the future. Selective harvesting, however, has the potential to significantly degrade local water quality. Some of the major sources of pollution from forests are disturbances which may be of natural origin, such as fires, disease, and earthquakes. Others may be caused by man. Principal pollutants are sediment, organic matter, chemicals (such as pesticides, fertilizers, and fire retardants), nutrients, and bacteria. Moreover, removal of streamside vegetation can cause thermal pollution of streams. The erosion rate from a harvested forest can be sao times higher than that from an undis- turbed forest and 2.5 times greater than that from copland, according to a 371 report by the EPA (1973). The same report also describes methods of predicting and controlling pollution from silviculture activities; these practices should, if followed, adequately contain water pollution. NONCOAL MINERAL EXTRACTION Eastern Montana contains several minerals other than coal that are commer- cially extractable, including oil and gas, sand and gravel, clays, gypsum, uranium, thorium, and chromite. All are potential contributors to water pol- lution. Currently, oil and gas wells are a widespread source of brine waters, but pollution can be limited to areas near the wells through pending and in- jection techniques. Potential problems are the mining of chromite from the Stillwater Complex in Sweetgrass and Stillwater counties, and the extraction of uranium and thorium from Carbon and Bighorn counties or from the Wyoming portion of the watershed. WYOMING ACTIVITIES Under the Yellowstone River Compact, Wyoming is entitled to a substantial portion of unappropriated waters of major tributaries to the Yellowstone River, ranging from 40 percent of the Tongue River to 80 percent of the Bighorn River. Although the exact quantities have not been determined, Wyoming estimates its share to be more than 2.4 mmaf/y. Although Wyoming has no firm plans to use this much water, significant diversions and depletions upstream, accompanied by return flows of lower quality than existing streamflows, could degrade water quality of the tributaries, especially the Powder and Tongue rivers and the lower Yellowstone River. NATIONAL ANO STATE POLICIES Controls have been or can be developed to control most water pollution. Remedies may require treatment of wastewater before discharge, modifications to the process producing the waste, or in an extreme case, curtailment of the pollution-causing activity. All remedies are influenced or controlled by governmental regulations. Thus, the major exogenous factors affecting future water quality of the Yellowstone River may well be policies of state and fed- eral governments. An increasing demand in the future for food and energy could lead to weakening of environmental standards. The combination of addi- tional energy extraction and conversion, expanded agricultural activities in the Yellowstone River Basin, and relaxed controls on environmental pollution could result in a major deterioration of water quality. RECOMMENDATIONS 1) The study was hindered because of lack of information on irrigation practices in the Yellowstone River Basin. It is suggested that a systematic long-term research program be initiated to collect data on the following: amount of water diverted for irrigation, volume and distribution of return flows, quality of return flows, and the impact of irrigation on streamflow. 372 2) A good beginning was made on integrating salinity calculations into the stat"e wate·r planning model~ · Addit"ional work is necessary, however, to refine the salinity. modeling, particularly on the lower subbasins. 3) Operations at Colstrip involving wastewater should be carefully moni-. to red to determine the impact of a 1 arge energy conversion faci 1 ity 4) 5) on,water quality.-····· -------~----~---· In July and August of low-flow ye'ars, salinity in the Bighorn River increases significantly. Salinity would be reduced and water quality .enhanced if_a minimum flow of· about 1000 cfs were maintained in the .river. / . Considering the potential adverse impacts on water quality resulting from additional irrigation in· the Powder and Tongue subbasins, it is suggested that a more thorough analysis be made of these two basins before substantial new developments are undertaken. 373 ·I ' ' . ' :: .·· ' " ' ,·, PR6.i~~TIONS 'OF FUTURE USE I . • ~-I I: : ,.,/: ' ' . . 'q : '':: :.: ''. , . FIGURES A-1. . r.~--... -·;...· .j.~· •. The tline Planning Subbas:ins of the. Yellowstone Basin ...... 377 TABl:ES A-.1. Increased Water: Requ'i rements • for Co a 1 Development in. the··Yellowstrine·.Basin in·2000:' ... -~ .. :; ·; : · 377 ··f _ ;· •· • o":, .2, • ' A-2. The Increase in. Water Depletion.: for Energy. A-3. A-4. ·,· r 11', , A-6: by the:."Y~ar 2000-by:Subbasin.~ .• ~--;-~-· .. :;· ~~.: .. ~ . ·.--. -:.:__ .•. \,;;:-.(;' •. ::;;,··. _;' _·:,-''.:,1: ·:_. :[ Feasib JY. Irri gable Acreage by :County· .and Subliasi n :.f: ·: · ~ .by 2000,.-fligh Level of Development:".~·.: ... -.. c·;·: •.•• . , -t··) ·. -', 1·;1· ~.-• f}'' ~ The i~c~eas~ iri Water Depletion for Irrigated Agricult~re !:bY 2000~by:·-Sutlbasin~~ :.; ..... ~ ~ . . . . . .... ·. . . . . . . --~·-__ ,._ ::..·1· .. ~---__ .-~. :· -· -.,,_ 378 379 380 . The .Incr:ease.-in Wate!' .. Depletion :for Municipal Use by 2000 380 :-.. -~::.-· .. _ ... __ -·._:,..-. __ ,r."'~·..:r;..:--:.:.~~: .::~· ·:::,:; -~ ~:--.. ·The.Increase in Water Depletion·:for. Consumpfive,Use .... (.·' ·by 2000 by Subbasin. ·. :. · _.,: .·,,.'.;.;r;._,.,, ..... ···' ... 381 .. · : ~: ' ~.-- ' ' '. '' ' . _:, l" .-· . :; '. . '' . ,. ; '-'• 375 •• l . . . ,· In order to adequately and uniformly assess the potential effects of water withdrawals on the many aspects of the present study, projections of specific levels of future withdrawals were necessary. The methodology by which these projections were done is explained in Report No. l in this series, in which also the three projected levels of development, low, intermediate, and high, are explained in more detail. Summarized bel01~. these three future levels of development were formulated for energy, irrigation, and municipal 1~ater use for each of the nine subbasins identified in figure A-1. ENERGY HATER USE In 1975, over 22 million.tons of coal (19 million metric tons) were mined in the state, up from 14 million (13 million metric) in 1974, ll million (10 million metric) in 1973, and 1 million (.9 million metric) in 1969. By 1980, even if no new contracts are entered, Montana's annual coal production will exceed 40 million tons (36 million metric tons). Coal reserves, estimated at over 50 billion economically strippable tons (45 billion metric tons) (Montana Energy Advisory Council 1976), pose no serious constraint to the levels of development projected, which range from 186.7 (170.3 metric) to 462.8 (419.9 metric) million tons stripped in the basin annually by the year 2000. Table A-1 shows the amount of coal mined, total conversion production, and associated consumption for six coal development activities expected to take place in the basin by the year 2000. Table A-2 sh01~s water consumption by sub- basin for those six activities. Only the Bighorn, Mid-Yellowstone, Tongue, Powder, and Lower Yellowstone subbasins would experience coal mining or associated development in these projections. IRRIGATION WATER USE Lands in the basin which are now either fully or partially irrigated total about 263,000 ha (650,000 acres) and consume annually about l ,850 hm3 ll ,5 mmaf) of water. Irrigated agriculture in the Yellowstone Basin has been increasing since 1971 (Montana DNRC 1975). Much of this expansion can be attributed to the introduction of sprinkler irrigation systems. After evaluating Yellowstone Basin land suitability for irrigation, con- sidering soils, economic viability, and water availability (only the Yell01~stone River and its four main tributaries, Clarks Fork, Bighorn, Tongue, and Powder, were considered as water sources), this study concluded that 95,900 ha (237,000 acres) in the basin are financially feasible for irrigation. These acres are identified by county and subbasin in table A-3; table A-4 presents projections of water depletion. Three levels of development were projected. The lo~1est includes one-third, the intermediate, two-thirds, and the highest, all of the feasibly irrigable acreage. 376 1 2 3 4 5 6 7 8 9 Upper Yellowstone Clarks Fork Yellowstone Billings Area Bighorn Mid -Yellowstone Tongue Kinsey Powder Lower Area Yellowstone ~ .. vsSlL!o"lLL ... r.aTL.&'"D I \ .J GOLCI"' ~ Figure A-1. The nine planning subbasins of the Yellowstone basin. TABLE A-1. Increased water requirements for coal development in the Yellowstone Basin in 2000. level of Oevelopr:~cnt Low Intermediate High Low Intenr.ediate Hiqh Low Intermediate High Electric Generation 8.0 24.0 32.0 2000 IIJool 6000 lrPoo' 8000 mw 30.000 90.000 120.000 I Coal Oevelop~nt Activity Gasifi-I cation Syncrude I COAL IIWED (r.r.~t/y) 7.6 0.0 7.6 0.0 22.8 36.0 CQ;IVERSIQ:I PRODUCTIO;I 250 mcfd 0 b/d 250 rrmcfd 0 b/d Ferti-1 l izer 0 0 0.0 3.5 a t/d 0 t/d 750 mcfd 200,000 b/d 2300 t/d WATER cmrsu;~PTI011 (af/v) 9.000 0 0 9.000 0 0 27,000 58.000 13.000 CONVERSIO;IS: 1 mt/y (short) • .907 rnt/y (rnetric) 1 af/y • .()0123 hm3jy Export I 171 . I 293.2 368.5 d 31,910 80.210 Strip Mininq 9.350 16.250 22.980 aNa water consumption is shown for export under tl1e low level of development because, for that development level, it is assiJmcd that all e:w;port is by rail, rather than by sliJrry pipelfn~. 377 Toul 186.7 324.8 462.8 43.350 147.160 321 .190 TABLE A-2. The increase in water depletion for energy by the year 2000 by subbasin. INCREASE II~ DEPLETIOI~ (af/v) Elec. Gasifi-Syn-Ferti-Strip Subbasin Generation cation crude lizer Export Mining Total LOV/ LEVEL OF DEVELOPMENT Bighorn 0 0 0 0 0 860 860 Mid-Yellowstone 22,500 9,000 0 0 0 3,680 35.1 so Tongue 7,500 0 0 0 0 3,950 11 ,450 Powder 0 0 0 0 0 860 B60 Lower Yellowstone 0 0 0 0 0 0 0 Total 30,000 9,000 9,350 48,350 INTERI~EOIATE LEVEL OF DEVELOPMENT Bighorn 0 0 0 0 4,420 1 ,470 5,890 Mid-Yellowstone 45,000 9,000 0 0 15,380 6 ,llO 75,490 Tongue 30,000 0 0 0 9,goo 7,000 46,900 Powder 15,000 0 0 0 2,210 1 ,670 18,880 Lower Yellowstone 0 0 0 0 0 0 0 Total 90,000 9,000 31,910 16,250 147,160 HIGH LEVEL OF DEVELOPMENT Bighorn 15,000 0 0 0 11 ,100 2,050 28,150 Mid-Yellowstone 45,000 18,000 29,000 0 38.700 8,710 13g,410 ·Tongue 45,000 9,000 29,000 0 24,860 10.170 118,030 Powder 15,000 0 0 0 5,550 2,050 22.600 Lower Yellowstone 0 0 0 13,000 0 0 13.000 Total 120,000 27,000 58,000 13,000 80,210 22,980 321,190 CONVERSIONS: 1 af/y = .00123 hm 3ty NOTE: The four subbasins not sho•m (Upper Yellowstone, Billings Area, Clarks Fork Yellowstone, Kinsey Area) are not expected to experience water depletion associated with coal development. 378 TABLE A-3. Feasibly irrigable acreage by county and subbasin by 2000, high level. of development. County Park Sweet Gras St iII water Carbon Yellow- stone Big Horn Treasure · Rosebud Powder River Custer Prairie Dawson Rich 1 and Wibaux BAS !r1 TOTALS Upper Clarks' Billings Sig Hid Tongue KiMey Powder Lower ellowstone Fork Area Horn Yellow'itone River Ar"ea River Yellowstone 21 ,664 10.20"- 6,208 38,076 2.160 2.160 19,412 13,037 9,591 11,408 4,230 19,412 13.037 25.229 2.185 9,727 10,035 21 ,947 46.813 3,092 26.<38 1,644 1,914 8.231 18,351 10,421 633 4,736 75.205 37.670 CONVERSIONS: 1 acre • .405 ha NOTE: The number of lrrlgable acres for the low and inte~ediate develo[)l!l(!nt levels are one-third and two-thirds, respectively, of the numbers given here. This table should not be considered an exhaustive listing of o~.l\ feasibly trrlqable acreo~.ge in t~e Yellowstone Basin: it includes only the acreaqe identified County Totals 21 ,564 10,20~ 6,208 2,160 19,•H2 1 5.222 9. 591 21 • 135 46,813 43,795 ·11,789 18,355 10,421 633 237,472 as feasibly lrrtgable accol"dlng to the geographic and econOC'lic constraints eKolalned elsewhere in this report. MUNICIPAL WATER USE The basin's projected population increase and associated municipal water use depletion for each level of development are shown in table A-5. Even the 13 hm3/y (10,620 af/y) depletion increase by 2000 shown for the highest develop- ment level is not significant compared to the projected depletion increases for irrigation or coal development. Nor is any problem anticipated in the availability of water to satisfy this increase in municipal use. WATER AVAILABILITY FOR CONSUfiPTIVE USE The average annua~ yield of the Yellowstooe River Basin at Sidney, r1ontana, at the 1970 level of development, is 10,850 hmJ (8.8 million af). As shown in table A-6, the additional annual depletions required for the high projected level of development total about 999 hm3 (Bl2,000 acre-feet). Comparison of these two numbers might lead to the conclusion that there is ample water for such development, and more. That conclusion would be erroneous, however, because of the extreme variation of Yellowstone Basin streamflows from year to year, from month to month, and from place to place. At certain places and at certain times the water supply will be adequate in the fore·seeable future. But in some of the tributaries and during low-flow times of many years, water ava i 1 ability prob 1 ems, even under the 1 0~1 1 eve 1 of deve 1 opment, wi 11 be very rea 1 and sometimes very serious. 37g TABLE A-4. The increase in water depletion for irrigated agriculture by 2000 by subbasin. Subbasin Upper Yellowstone Clarks Fork Billings Area Bighorn Mid-Yellowstone Tongue Kinsey Area Powder Lower Yellowstone TOTAL Acreage Increase HJr,H LEVEL OF DEVELOPMENT 38,080 2,160 19,410 13.040 25,230 21 • 950 4,740 75,200 37,670 237,480 Increase in Depletion (af/y) 76 ,160 4,320 38,820 26,080 50,460 43,900 9,480 150,400 75,340 474,960 INTERMEDIATE LEVEL OF DEVELOPMENT BASIN TOTAL 1 158.320 316,640 LOW LEVEL OF DEVELOPMENT BASIN TOTAL 79. 160 158,320 CONYERS IONS: l acre = . 405 ha l af/y = .00123 hm3/y NOTE: The numbers of irrigated acres at the low and intermediate levels of development are not shown by subbasin; however, those numbers are one-third and two-thirds, respectively of the acres shown for each subbasin at the high level of development.' TABLE A-5. The increase in water depletion for municipal use by 2000. Level of Development Low Intermediate High Population Increase 56,858 62,940 94,150 CONVERSIONS: l af/y = .00123 hm3/y 380 Increase in Depletion (af/y) 5,880 6,g6o 10,620 TABLE A-6. The increase in water depletion for consumptive use by 2000 by subbasin. Increase in Depletion (af/y) Subbasin Irrigation Energy Municipal Total LOW LEVEL OF DEVELOPMENT Upper Yellowstone 25,380 0 0 25,380 Clarks Fork l ,440 0 0 l ,440 Billings Area 12.940 0 3,480 16,420 Bighorn 8,700 860 negligible 9,560 f1i d-Ye ll ows tone 16,820 35,180 l ,680 53,680 Tongue 14,640 ll ,450 negligible 26,090 Kinsey Area 3,160 0 0 3,160 P01·1der so. 140 860 360 51 ,360 LOI<er Yellowstone 2 5.120 0 360 25,480 TOTAL 158,340 48,350 5,880 212,570 INTERMEDIATE LEVEL OF DEVELOPriENT Upper Yellowstone 50 ,78D 0 0 50,780 Clarks Fork 2,880 0 0 2,880 Billings Area 25,880 0 3,540 29,420 Bighorn 17,3130 5,890 300 23.570 Mid-Yellowstone 33,640 75,490 1 ,360 110.990 Tongue 29,260 46,900 . 300 76,460 Kinsey Area 6,320 0 0 6,320 Powder 100,280 18,380 600 119,760 Lower Yellowstone 50,200 0 360 50,560 TOTAL 316,620 147,160 6,960 470,740 HIGH LEVEL OF DEVELOPMENT Upper Yellowstone 76 ,160 0 0 76,160 Clarks Fork 4,320 0 0 4,320 Billings Area 38,820 0 3,900 42,720 Bighorn 26,080 28.150 480 54,710 f1id-Yellowstone 50,460 139,410 3,1340 193,710 Tongue 43,900 118,030 780 162,710 Kinsey Area 9,480 0 0 9,480 Powder 150,400 22,600 1.140 174,140 Lower Yellowstone 75,340 13,000 480 88,82C TOTAL 474,960 321,190 10,620 806.770 COrNERS IONS: 1 af/y = .00123 hm3/y 381 Allison, L.E. 1964. Salinity in relation to irrigation. Advances in Agronomy 16:139-180. APHA, AWWA, and WPCF. and wastewater. York. 1971. Standard methods for the examination of water 13th edition. American Public Health Association, New Battelle Columbus Laboratories. 1974. Liquefaction and chemical refining of coal. Columbus, Ohio. Bean, E.H. 1962. Progress report on water quality criteria. American Water Works Association Journal 54:1313-1331. Beartooth Resource Conservation and Development Project (and other agencies). 1973. A study of erosion and sedimentation--Montana portion, Clarks Fork Yellowstone River Basin. Prepared for the 1973 Montana Legislative Assembly, Helena. Berg, R. 1977. Upper Yellowstone fishery. Montana Outdoors 8{2):27-29. Montana Department of Fish and Game, Helena. Beychok, M. R. 1975. Process and environmental technology for producing SNG and liquid fuels. EPA-660/2-75.011. U.S. Environmental Protection Agency, Corvallis, Oregon. Bishop, C. 1974. Interview with district fisheries manager, Montana Department of Fish and Game,. Billings, June 25. Boies, D. B., J. E. Levin, and B. Baratz. 1973. Technical and economic evaluations of cooling systems blowdown control techniques. EPA-650/2-73-026 U.S. Environmental Protection Agency, Washington, D.C. Botz, M.K. and D. Pederson. 1975. Summary of water quality criteria {preliminary draft). Water Quality Bureau, Montana Department of Health and Environmental Sciences, Helena. 2 pp. Bovee, K.D. 1975. The determination, assessment, and design of "instream va 1 ue" studies for the northern Great Plains region. Prepared for the Northern Great Plains Resources Program, Denver; University of Montana, Missoula. 205 pp. Boyd, F. R. 1951. Welded tuffs Yellowstone Park, Wyoming. 72:387-426. and flows in the rhyolite plateau of Geological Society of America Bulletin. Brown, E., M.W. Skougstad, and M.J. Fishman. 1970. Methods for collection and analysis of water samples for dissolved minerals and gases. U.S. Geological Survey Techniques of Water Resources Inventory, book 5, chapter Al; United States Department of. the Interior, Washington> D.C. 150 pp. 3R3 Brown, R.M., N.J. McClelland, R.A. Deininger, and R.G. Tozer. 1970. A water quality index -do we dare? (Presented at the National Symposium on Data and Instrumentation for Water Quality Management, Madison, Wisconsin) Water & Sewage Works 117:20. Brown, R.M., N.J. McClelland, R.A. Deininger, and J.M. Landwehr. 1973. Validating the WQI. Presented at the American Society of Civil Engineers National Meeting on Water Resources Engineering, Washington, D.C. Brown, R.M. and N.J. McClelland. 1974. Up from chaos: the Water Quality Index as an effective instrument in water quality management. Presented to the Conference of State Sanitary Engineers during the Meeting of the Interstate Conference on the Environment, Cincinnati, Ohio. National Sanitation Foundation, Ann Arbor, Michigan. 27 pp. California State Water Quality Control Board. 1963. Water Quality for live- stock: guides for the evaluation of the quality of water used by live- stock. State Water Resources Control Board, Sacramento, California. Carter, R.W. and J. Davidian. 1968. General procedure for gaging streams. U.S. Geological Survey Techniques of Water Resources Inventory book 3, Chapter A6; United States Department of the Interior, Washington, D.C. 13 pp. Chopey, N.O. 1974. Gas-from-coal: an update. Chemical Engineering. March. Cochran, N.P. 1976. Oil and gas from coal. Scientific American. Vol. 234, No. 5. May. Colston, N.V. Jr. 1974. Characterization and treatment of urban land run-off. EPA-670/2-74-096. U.S. Environmental Protection Agency, Cincinati, Ohio. Cooper, H. B.H. Jr. 1975. The ultimate disposal of ash and other solids from electric power generation. Presented at Eighth Water Resources Symposium on Water Management by the Electric Power Industry. January, 1976. University of Texas, Austin, Texas. Davis, S.N. 1964. Silica in streams and ground water. American Journal of Science 262:870-891. Dickinson, E. 1975. Impact of developing synthetic fuels from coal and oil shale in the western Unfted States. Seminar at Montana State University, Bozeman, Montana. December 15. Dollhoph, D.J. and M.E. Majeras. 1975. Strip mine reclamation research located at Decker Coal Company, Decker, Montana. Montana Agriculture Experimentation Research Report 83. Durfor, C.N. and E. Becker. 1964. Public water supplies of the 100 largest cities in the United States, 1962. U.S. Geological Survey Water Supply Paper 1812; United States Department of the Interior, Washington, D.C. 364 pp. 384 \ Durum, W.H. and J. Haffty. 1963. Implications of the minor element content of some major streams of the world. Geochim. et Cosmochim. Acta 27:1-11. Eldridge, E.F. 1960. Return irrigation waters: characteristics and effects. U.S. Department of Health, Education, and Welfare. Portland, Oregon. Ellis, M.M. 1944. Water purity standards for fresh-water fishes. Special Scientific Report No. 2, United States Department of the Interior, Washington, D.C. European Inland Fisheries Advisory Commission. 1965. Report on finely divided solids and inland fisheries. Working Party on Water Quality Criteria for European Freshwater Fish, Air Water Pollution 9(3):151-168. Geissler, R.H. 1976. Range lands ripped for new wheat boom. Billings Gazette, Billings, Montana. May 16. Gerloff, G.C. and F. Skoog. 1957. Nitrogen as a limiting factor for the growth of Microcystis aeruginosa in southern Wisconsin lakes. Ecology 38(4):556-561. Gunnerson, C. 1966. An atlas of water pollution surveillance in.the U.S., to September 30, 1965. Federal Water Pollution Control United States Department of the Interior, Cincinnati, October 1 , 1957 Administration, Ohio. 78 pp. Guy, H.R. 1969. Laboratory theory and methods for sediment analysis. U.S. Geological Survey Techniques of Water Resources Inventory, book 5, chapter Cl; United States Department of the Interior, Washington, D.C. 58 pp. Hart, W.B., P. Doudoroff, and J. Greenbank. 1945. The evaluation of the toxicity of industrial wastes, chemicals and other substances to fresh- water fishes. Haste Control Laboratory, The Atlantic Refining Company of Philadelphia, Philadelphia, Pennsylvania. Hem, J.D. 1970. Study and interpretation of the chemical characteristics of natural water. 2nd edition. U.S. Geological Survey Water Supply Paper 1473; United States Department of the Interior, Washington, D.C. 363 pp. Hodder, R.L. 1976. Senior Research Associate, Department of Animal and Range Sciences, Montana State University, Bozeman. Personal communication. Hodder, R.L., D. E. Ryerson, R. Mogen, and J. Buchholz. 1972. Coal mine spoils reclamation research project located at Western Energy·Company, Colstrip, Montana (progress report, 1970). Research Report 8, Montana Agricultural Experiment Station, Montana State University, Bozeman, 56 pp. Hodder, R.L., B.W. Sindelar, J. Buchholz, and D. E. Ryerson. 1973. Coal mine land reclamation research located at Western Energy Company, Colstrip, Montana (progress report, 1971). Research Report 20, Montana Agricultural Experiment Station, Montana State University, Bozeman. 45 pp. ' 385 Horton, M.L., J.L. Wiersma, and J.L. Holbeisin. 1976. in the northern Great Plains. EPA-600/2-76-188. Protection Agency, Ada, Oklahoma. Animal waste management U.S. Environmental Inhaber, H. 1975. An approach to a water quality index for Canada. Water Research (Pergamon Press, Great Britain) 9:B21-833. Jankowski, W.A. and M.K. Botz. 1974. Field procedures manual--collection, analysis and reporting of water quality samples (preliminary draft). Water Quality Bureau, Montana Department of Health and Environmental Sciences, Helena. 70 pp. Jensen, I.B. 1975. Effects of surface configuration in water pollution con- trol on semiarid surface mined lands. Animal and Range Sciences Department, Montana State University, Bozeman. Kaiser, J., P. Gorman, and M.K. Botz. 1975. Investigations of salinity in hydrological systems in Montana. Technical Report 75-l, Water Quality Bureau, Montana Department of Health and Environmental Sciences, Helena. 102 pp. Karp, R.W. and M.K. Botz. 1975. Water quality inventory and management plan--Middle Yellowstone River Basin, Montana. Water Quality Bureau, Montana Department of Health and Environmental Sciences, Helena. 177 pp. Karp, R.W., D.A. Klarich, and M.K. Botz. 1975b. Water quality inventory and management plan--Lower Yellowstone River Basin, Montana. Water Quality Bureau, Montana Department of Health and Environmental Sciences, Helena, 136 pp. 1976a. Water quality inventory and management plan--Upper Yellowstone Basin, Montana. Water Quality Bureau, Montana Department of Health and Environmental Sciences, Helena. 153 pp. Karp, R.W., W.H. Garvin, M.K. Botz, and D.A. Klarich. 1976b. Waste load allocation investigation of the Yellowstone River in the vicinity of Billings, Montana (in preparation). Water Quality Bureau, Montana Department of Health and Environmental Sciences, Helena. Klarich, D.A. 1976. Periphyton community structure in the Yellowstone River (Laurel to Huntley, Montana) and estimates of primary production (preliminary draft). Water Quality Bureau, Billings Branch Office, Montana Department of Health and Environmental Sciences, Billings. 107 pp. Klarich, D.A. and J.C. Wright. 1974. Effect of removal of wastewater treat- ment plant effluent from the Madison River, Yellowstone National Park. A final report for contract CX 6000-3-0075, National Park Service, Yellowstone National Park, Mammoth, Wyoming. 44 pp. Knudson, K. and D. Swanson. 1976. Effects of decreased water quantity and increased nutrient additions on algal biomass accumulation, and subsequently, the dissolved oxygen balance of the Yellowstone River. Montana Department of Fish and Game, Helena. 386 \. Koch, R. 1977. The effect of altered streamflow on the hydrology and geo- morphology of the Yellowstone River Basin, Montana. Yellowstone Impact Study technical report No. 7. Montana Department of Natural Resources and Conservation, Helena. Lee, G.F. and A.W. Hoodley. 1967. Biological activity in relation to chemical equilibrium composition of natural waters. In: Equilibrium concepts in natural water systems. American Chemical Society Advances in Chemistry Series, 67:319-338. Lewis, K.F. and J.M. Smith. 1973. Upgrading existing lagoons. National Environmental Research Center, Cincinnati, Ohio. Lund, J.W.G. 1965. The ecology of freshwater phytoplankton. Biological Review 40:231-293. Mackenthun, K. 1969. The practice of water pollution biology. Federal Water Pollution Control Administration, United States Department of the Interior, Washington, D.C. 281 pp. Madsen, R. 1975. U.S. Bureau of Reclamation, Billings, Montana. Ur.published data. Manfredi, J. 1976. U.S. Bureau of Reclamation, Billings, Montana. Personal communication. Manges, N.L., R.I. Lipper, L.S. Murphy, W.L. Powers, and L.A. Schmid. 1975. Treat- ment and ultimate disposal of cattle feedlot wastes; EPA-660/2-75-013. U.S. Environmental Protection Agency, Corvallis, Oregon. Marcuson, P. and G.G. Bishop. 1973. South central Montana fisheries study-- inventory of the waters of the project area. Job progress report: Project F-20-R-16, Job 1-a, Fisheries Division, Montana Department of Fish and Game, Billings. ll pp. McClelland, Basin. Kansas N.J. 1974. Water Quality Index application in the Kansas River EPA-907/9-74-001, United States Environmental Protection Agency, City, Missouri. 226 pp. McKee, J.E. and H.W. Wolf, eds. 1974. Water quality criteria. 2nd edition. Publication 3-A, California State Water Resources Control Board, Sacramento, California. 548 pp. Middlebrooks, E.J., D.H. Falkenborg, R.F. Lewis, and D.J. Ehreth. 1974. Upgrading wastewater stabilization ponds to meet new discharge standards. Utah Water Research Laboratory Report PRWG 159-1. Logan, Utah. Millipore Corporation. 1g72. Biological analysis of water and wastewater. Application Manual AM 302. Bedford, Massachusetts. 80 pp. Missouri River Basin Inter-Agency Committee. 1969. Comprehensive framework study. Volumes 1-9. Montana Department of Community Affairs. 1976 (December). Economic conditions in Montana: a report to the Governor. Research and Information Systems Division, Helena. 35 pp. 387 1-lontana Department of Health and Environmental Sciences. 1972. Yellowstone County--Water pollution control report. Water Quality Bureau, Billings Branch Office, Environmental Sciences Division, Billings. 22 pp . . 1973. Summary of state and federal water pollution control laws, ----~w7a~te~r pollution control legislation, status of municipal and industrial dischargers. Montana Water Pollution Control Report, Water Quality Bureau, Environmental Sciences Division, Helena. 10 pp. 1975. Montana water pollution control program plan for fiscal year 1976. Water Quality Bureau, Environmental Sciences Division, Helena. 99 pp. 1976. Water quality in Montana. Report prepared for the Environmental Protection Agency pursuant to Public Law 92-500, Section 305(b). Water Quality Bureau, Environmental Sciences Division, Helena. 36 pp. Montana Water quality standards. ~1AC 16-2.14(10)-Sl4480. Helena. 26 pp. Montana Department of Natural Resources and Conservation. 1974. Draft environ- menta 1 impact statement on the proposed Montana Power 'Company, Puget Sound Power and Light Company, Portland General Electric Company, Pacific Power and Light Company, and Washington Water Power Company, Colstrip electrical generating units 3 & 4, 500 kilovolt KV transmission lines from Colstrip to Hot Springs, Montana, and associated facilities. Volumes 1-4. Energy Planning Division. Helena. 1g75. A study to evaluate potential physical, biological, and water use impacts of water withdrawals and water development on the middle and lower' portions of the Yellowstone River drainage in Montana. Water Resources Division, Helena. 1976 (December). Yellowstone River Basin: draft environmental 1mpact statement for water reservation applications. Two volumes. Water Resources Division, Helena. 412 pp. 1977 (January). The future of the Yellowstone River. . ? Water Resources Division, Helena. 107 pp. Montana Energy Advisory Council. 1976 (June). Montana energy position paper: a Montana Energy Advisory Council staff report, by Theodore H. Clack, Jr. Helena. 56 pp. Montana State Board of Health, Helena; State Department of Health, Bismarck, North Dakota; and the United States Public Health Service (HEW, Region VI). 1956. Yellowstone River pollution study, November, lg55-- Pollution of the Yellowstone River as related to taste and odor problems in municipal water supplies in Montana and North Dakota. Helena. 31 PP·. Montana Water Quality Bureau. 1975. Open-file data. Billings. Montana Water Resources Board. An atlas of water resources in Montana by hydrologic basin. Helena. 388 I ~ Moseley, J.C. II. 1974. Establishment of operational guidelines for Texas coastal zone managment. Final report on example application I. Civil Engineering Department, University of Texas, Austin, Texas. Mudge, L.K., G.F. Schiefelbein, C.T. Li, and R.H. Moore. 1974. The gasification of coal. Battelle Pacific Northwest Laboratories, Richland, Washington. Muller, W. 1953. Nitrogen content and pollution of streams. Water Pollution Abstracts 28(2), Abstract No. 454. National Commission on Water Quality. 1976. Report to the Congress. U.S. Government Printing Office, Washington, D.C. March 18. National Technical Advisory Committee. 1968. Water quality criteria. Report to the Secretary of the Interior, United States Department of the Interior, Washington, D.C. 20 pp. North Central Power Study Coordinating Committee. 1971 (October). North central power study: report of phase I. Volume I. Bureau of Reclamation, Billings, Montana. 80 pp. Northern Great Plains Resources Program. 1974. Water quality subgroup report. United States Environmental Protection Agency, Region VIII, Denver, Colorado. 530 pp. Persse, F.H. 1975. Strip mining techniques to minimize environmental damage in the upper Missouri River Basin states. Bureau of Mines information circular 1975. U.S. Department of Interior. Peterman, L. and K. Knudson. 1975. Water quality proposal--Yellowstone River: acquisition of water quality data necessary for the prediction of impacts on aquatic communities in the Yellowstone River Basin resulting from reduced stream flows associated with energy development. Montana Department of Fish and Game, Miles City. 15 pp. Peterman, L. 1977. Lower Yellowstone fishery. Montana Outdoors 8(2):33-35. Montana Department of Fish and Game, Helena. Peters, J.C. 1962. The effects of sedimentation on trout embryo survival. Third Seminar on Biological Problems in Water pollution, August: 275-279. Project F-20-R, Montana Department of Fish and Game, Billings. Pillsbury, A.F. and H.F. Blaney, 1966. Salinity problems and management in river systems. Journal of Irrigation and Drainage Division, American Society of Civil Engineers. March. Rainwater, F.H. and L.L. Thatcher. 1960. Methods for collection and analysis of water samples. U.S. Geological Survey Water Supply Paper 1454; United States Department of the Int.eri or, Washington, D.C. 301 pp. Rasmussen, S.M. 1968. Composition and structure of macrophyte vegetation of the Firehole River, Yellowstone National Park, as related to physical and chemical factors. M.S. thesis, Montana State University, Bozeman. 46 pp. 339 Richards, L.A., ed. 1954 .. Diagnosis and improvement of saline and alkali soils. USDA Agricultural Handbook No. 60, U.S. Salinity Laboratory Staff, United States Department of Agriculture, Washington, D.C. Robinove, C.J., R.H. Langford, and J.W. Brookhart. 1958. Saline-water· r·esources of North Dakota. U.S. Geological Survey Water Supply Paper 1428; United States Department of the Interior, Washington, D.C. 72 pp. Rocky Mountain Association of Geologists. 1972. Mountain Region: Uni_ted States of America. Geologic atlas of the Rocky . Denver. 331 pp. Roeder, T.S. 1966. Ecology of diatom communities of the upper Madison River system, Yellowstone National Park. Ph.D. thesis, Montana State University, Bozeman. 85 pp. Rubin, E.S. and F.C. McMichael. 1975. Impact of regulations on coal conver- sion plants. Environmental Science and Technology. February. Ruff, J.F., M.W. Skinner, J.W. Keys III, and D. Waugaman. 1972. A remote sensing study of sediment in the Clarks Fork Yellowstone River. Prepared "' ~or the Bureau of Reclamation, Denver; Civil Engineering Department, _ ~olorado State University, Fort Collins. 95 pp. Salvato, J. 1958. Environmental sanitation. John Wiley and Sons, Inc., flew' York. 637 pp. Schmidt, J. 1976. Montana Department of State Lands. Personal communication. Scofield, C.S. 1936. The salinity of irrigation water. Smithsonian Report for 1935. Seghetti, L. 1951. Correspondence to the project engineer from Montana State College, Agricultural Experiment Station, Bozeman, Montana (Aug. 15). Referenced in Water Quality Criteria, Publication 3-A, California State Water Resources Control Board, Sacramento, California. p. 113. SERNCO. 1974. Applicant's environmental impact assessment for a proposed gasification project in Campbell and Converse Counties, Wyoming. Slack, K.V. et al. 1973. Methods for collection and analysis of aquatic biological and microbiological samples. U.S. Geological Survey Techniques of Water Resources Inventory, books, chapter A4. United States Department of the Interior, Washington, D.C. 165 pp. Snedecor, G.W. 1946. Statistical methods. Iowa State University Press. Ames, Iowa. Soltero, R.A. 1971. Linological studies on Bighorn Lake (Yellowtail Dam) and its tributaries. Ph.D. thesis, Montana State University, Bozeman. 271 pp. Soltera, R.A. et al. 1973. Effects of impoundment on the water quality of the Bighorn River. _Water Research (Pergamon Press, Great Britain) 7:343-354. 390 I ' I ~ \ Sprindler, J.C. Field investigation: Yellowstone River between Laurel and Huntley (lg65). Report on ·file with the Water Quality Bureau, Montana Department of Health and Environmental Sciences, Billings. 10 pp. Stadnyk, L. 1971. Factors affecting the distribution of stoneflies in the Yellowstone River, Montana. Ph.D. Thesis, Montana State University, Bozeman. 36 pp. State Conservation Needs Committee. 1970. Montana soil and water conservation needs inventory. Soil Conservation Service, Bozeman. 1972 pp. Sylvester, R.O. and R.W. Seabloom. 1963 (September). Quality and signi- ficance of irrigation return flow. Journal of Irrigation and Drainage Division, American Society of Civil Engineers. Thomas, J.L. 1975. Water requirements and wastewater potential of coal- energy facilities. Proceedings of Fort Union Coal Field Symposium, held at Eastern Montana College in Billings, Montana. April 25 and 26. Thurston, R.V., R.J. Luedtke, and R.C. Russo. 1975. Completion report: upper Yellowstone River water quality, August 1973 to August 1974. project No. A-081-MONT, Montana University Joint Water Resources Research Center, Report No. 68; Fishe-ries Bioassay Laboratory, Montana State University, Bozeman. 57 pp. U.S. Bureau of Indian Affairs. 1976. Draft environmental impact statement: Crow ceded area coal leases, Tracts II and Ill, Westmoreland Resources. Appendix F: Hydrology. DES 76-30. U.S. Department of the Interior, Billings. U.S. Department of Health, Education and Welfare. 1962. Drinking water standards, 1962. Public Health Service Publication No. 956. Washington, D.C. 61 pp. U.S. Department of the Interior. 1966-74a (annual publication). Water resources data for Montana. Part 1. Surface Water records. Water Resources Division, Geological Survey, Helena, Montana. l966-74b (annual publication). Part 2. Water quality records. Water Survey, Helena, Montana. Water resources data for Montana. Resources Division, Geological 1968. State of Montana: major, submajor, and minor drainage basins (map). Geological Survey, Washington, D.C. Powder Bureau 1969. Reconnaissance report on Moorhead Unit. Montana-Wyoming, Division, Missouri River Project. Upper Missouri Project Office of Reclamation, Great Falls, Montana. ' 1972. Report on resources of eastern Montana basins. Pick-Sloan Missouri Basin Program. Bureau of Reclamation, Billings, Montana 128 pp. 391 1974. El Paso coal gasification project, draft environmental impact statement. 1974. Water resources data for Montana. Part 1. Surface water records. Water Resources Divis ion, Geological Survey, Helen a, Montana. 289 pp. 1974. Water resources data for Montana. Part 2. Water quality records. Water Resources Division, Geological Survey, Helena, Montana. 194 pp 0 1975. Otter creek study site. EMRIA Report 1. Bureau of Land Management. 1976. Water-resources investigations of the U.S. Geological Survey in the Northern Great Plains coal region of eastern Montana, 1975-1976. Open-file report; Water Resources Division, Geological Survey, Helena, Montana. U.S. Departments of the Interior and Agriculture. 1973. Land use recommendations for the Pryor Mountains. Bureau of Land Management and Forest Service. Washington, D.C. u.s. l974a. Pryor Mountains complex land-use decisions. Bureau of Land Management and Forest Service, Washington, D.C. l974b. Summary: Decker-Birney resource study. Bureau of Land Management and Forest Service. Washington, D.C. 89 pp. Environmental Protection Agency. 1972. baseline water quality survey report. City, Missouri. 174 pp. Yellowstone National Park Regions VII and VIII, Kansas 1973. Methods and practice for controling water pollution from agricultural nonpoint sources. EPA-430/9-73-015. Washington, D.C. 1973. Methods for identifying and extent of nonpoint sources of pollution. Washington, D.C . evaluating the nature and EPA-430/9-73-014. . 1973. Water quality criteria, 1972. Report of the Committee ----~o~n'Water Quality Criteria, EPA-R3-73-033. Environmental Studies Board, National Academy of Sciences and National Academy of Engineering. Washington, D.C. 594 pp. 1974a. Methods for the chemical analysis of water and wastes. Cincinnati, Ohio. 1974b. National water Volume I. EPA-440/9-74-001. Washington, D.C. 305 pp. quality inventory--1974 report to Congress. Office of Water Planning and Standards, 197~. National eutrophication survey: national eutrophication survey methods, 1973-1976. Working paper series: Working Paper No. 175, National Environmental Research Center, Corvallis, Oregon and Las Vegas, Nevada. 91 pp. 392 1976. Draft first year progress report of a techn0logy assessment of western energy resources development. Contract No. 68-01-1916. Office of Research and Development, Washington, D.C. 1976. Qua 1 ity criteria for water. EPA-440/9-76-023. ~Ia shi ngton, D.C. 501 pp. Utah State University Foundation. 1969. The characteristics and pollution problems of irrigation return flows. U.S. Department of Interior, Federal Water Pollution Control Administration. Van Voast, W.A. 1974. Hydrologic effects of strip coal mining in southeastern Montana -emphasis: one year of mining near Decker. Bulletin 93. Montana College of Mineral Science and Technology, Butte. Van Voast, W.A., R.B. Hedges, and G.K. Pagenkopf. of coal mine effluents and spoil leachates. Coal Field Symposium held at Eastern Montana Montana, on April 25 and 26. 1975. Hydrologic impacts Proceedings of Fort Union College in Billings, Van Voast, W.A. and R.B. Hedges. 1975. Hydrogeologic aspects of existing and proposed strip coal mines near Decker, southeastern Montana .. Bulletin 97. Montana College of Mineral Science and Technology, Butte. · 1976. Hydrogeologic conditions and projections related to mining near Colstrip, southeastern Montana. Open-file report. Montana College of Mineral Science and Technology, Butte. Whalen, I.E. 1951. The direct effect of turbidity on fishes. Bulletin of Oklahoma Agricultural and Mechanical College. 48(2):1-27. Whalen, S.C., P.J. Garrison, and R.W. Gregory. April 15, 1976. Limnology of the Tongue River Reservoir, existing and potential impact of coal strip mining. Second progress report. Cooperative Fishery Research Unit, Department of Biology, Montana State University, Bozeman. 70 pp, Wright, J.C. and I.K. Mills. Productivity studies on the Madison River, Yellowstone National Park. Limnology and Oceanography 12(4):568-577. Wright, J.C. and R.A. Soltero. 1973. Limnology of Yellowtail Reservoir and the Bighorn River. EPA-R3-73-002. Ecological Research Series. United States Environmental Protection Agency, Washington, D.C. ·105 pp. 393