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Home My WebLink AboutCordova Power Supply Interim Feasibility Assessment Addendum 1, Nov 19821 Ave. > Alaska 99501 ‘Anchorage, Alaska CORDOVA POWER SUPPLY INTERIM FEASIBILITY ASSESSMENT ADDENDUM |! NOVEMBER 1982 Stone & Webster Engineering Corporation ALASKA POWER AUTHORITY | i a | | a 1 7 i L i i i i i i i i STONE & WEBSTER ENGINEERING CORPORATION DENVER OPERATIONS CENTER GREENWOOD PLAZA, DENVER, COLORADO ADDRESS ALL CORRESPONDENCE TO P.O. BOX 5406. DENVER, COLORADO 60217 BOSTON N TELEPHONE: 303-770-7700 NEW YORK W.U.TELEX:45-4401 CHERRY HILL.N.J. DENVER CHICAGO HOUSTON PORTLAND, OREGON SAN DIEGO WASHINGTON, D.C Mr. Eric Yould November 22, 1982 Executive Director Alaska Power Authority J. O. No. 14101.90 334 W. 5th Avenue, 2nd Floor Anchorage Alaska, 99501 Dear Mr. Yould: ADDENDUM TO THE INTERIM FEASIBILITY ASSESSMENT CORDOVA FEASIBILITY STUDY - PHASE I The attached Addendum contains supplementary information to the Interim Feasibility Assessment of power supply alternatives for the City of Cordova accomplished for the Alaska Power Authority under contract CC08-2318. The Addendum provides an assessment of potential hydroelectric sites in the Copper River drainage basin downstream of Taral and a wood-fired powerplant in Cordova not previously considered. The economic life of the diesel waste heat options were extended and the cost of diesel fuel was adjusted to reflect the October 1982 price in Cordova. The operations and maintenance costs for each hydroelectric site and its associated transmission line have been revised based upon the recent Power Authority experience for the Solomon Gulch Hydroelectric Project. In addition, the hydroelectric estimates were updated to include costs associated with land and damages and reservoir clearing not previously considered. The present worth cost and the benefit/cost ratios were re-calculated for the revised best generation alternatives identified in the Interim Feasibility Assessment and the three new Copper River alternatives, Van Cleve Lake and two Tiekel River Sites, for low, mean and high electrical demand forecasts. The forecasts are predicated on the demand forecasts of wes Mr. E. Yould November 22, 1982 Page Two R. W. Retherford Associates Reconnaissance Study of Energy Requirements and Alternatives for the City of Cordova, June 1981; and the Battelle, Pacific Northwest Laboratories Railbelt Electric Power Alternative Study: Evaluation of Electric Energy Plans, Addendum, November 1982. The low forecasts upon which project economics were based, are 2 percent annual growth, which is lower than Battelle's current thinking, and about 40 percent lower than recent statewide power growth history. We believe this demonstrates a most conservative approach to determining the economic sensitivity of the preferred alternatives. The Silver Lake alternative remains the "best cost" alternative when considered on a regional basis and the low forecast cited above. Five months of environmental and geologic field investigations have been completed which have confirmed the viability of development at Silver Lake. We again recommend that the Power Authority initiate a feasibility study of the Silver Lake option. Very truly yours, Mtrdnckeowts N. K. Whitcomb Project Manager NKW/NAB/ke Enclosure ADDENDUM CORDOVA POWER SUPPLY INTERIM FEASIBILITY ASSESSMENT Volume 1 November 1982 goe0 a KE Wren 10.0 11.0 ADDENDUM CORDOVA POWER SUPPLY INTERIM FEASIBILITY REPORT TABLE OF CONTENTS VOLUME 1 Executive Summary Introduction Existing Power Supply System Electrical Energy Forecasts Diesel Generation Coal Generation Hydroelectric Generation Transmission Systems Economics Comparison of Alternatives Conclusions and Recommendations Appendix - Meetings and Comments Assessment Cost Estimates Van Cleve Lake Tiekel River - River Mile 11.3 Tiekel River - River Mile 13.5 Engineering Memoranda VOLUME 2 Silver Lake Field Data VOLUMES 3 AND 4 Supplementary Economic Data Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table -4-2 4-3 24-5 4-6 «4-7 0-1 0-2 0-3 -0-4 ‘025 0-6 sFot LIST OF TABLES Present Worth Costs and Benefit/Cost Ratios Best Generation Alternatives Low Electrical Load Forecast City of Cordova Mean Electrical Load Forecast City of Cordova Highest Electrical Load Forecast City of Cordova Forecast of Cordova Power Requirements Forecast of Valdez-Glennallen Power Requirements Effect of Solomon Gulch on Valdez-Glennallen Load Forecasts Cordova-Valdez-Glennallen Combined Load Forecast Hydroelectric Plant 0 & M Costs Silver Lake Hydroelectric Project Transmission Line O & M Costs (TO2) Hydroelectric Plant O & M Costs Allison Lake Hydroelectric Project Transmission Line O & M Costs (TO1) Hydroelectric Plant 0 & M Costs Crater Lake, Sheep River Lake, Lake 1488 Hydroelectric Project Transmission Line O & M Costs Small Hydro Cost Estimate Van Cleve Lake Table Table Table Table Table Table Table Table Table Table Table Table 10.0-1 10.0-2 10.0-3 10.0-4 Hydroelectric Plant 0 & M Costs Van Cleve Lake Hydroelectric Project Transmission Line 0 & M Costs Van Cleve Lake (TO3 Plus 4 Mile Tap) Cost Estimate Tiekel River Hydroelectric Plant O & M Costs Tiekel River Hydroelectric Project Transmission Line 0 & M Costs Tiekel River (TO1 Plus 6 Miles Tap to CVEA Solomon Gulch-Glennallen Line) Excess Hydroelectric Power Sold to CVEA Cordova Low-Growth Load Valdez-Glennallen Low-Growth Load Excess Hydroelectric Power Sold to CVEA Cordova Mean-Growth Load Valdez-Glennallen Low-Growth Load Excess Hydroelectric Power Sold to CVEA Cordova Level 2 (High) Load Valdez-Glennallen Low-Growth Load Benefit/Cost Ratios Cordova Low-Growth Load Benefit/Cost Ratios Cordova Mean-Growth Load Benefit-Cost Ratios Cordova Level 2 (High) Load Present Worth Costs and Benefit/Cost Ratios Best Generation Alternatives Figures 4.4-1 Figures 4.4-2 Figure Figure Figure Figure Figure Figure Figure Figure Figure 4.4-3 4.4-4 4.4-5 5.5°1 7-0-3 7 .@-2 9.3-1 9.32 9.3-3 LIST OF FIGURES Cordova Space Heating Fuel Escalation, APA FY82 Criteria, 2.6% Fuel Escalation Cordova Consumer Space Heating Alternative Costs, Silver Lake - 15 MW Capacity - Excess Power Sold to CVEA, Cordova Low-Growth Load, Valdez-Glennallen Low-Growth Load, No State Funding, APA FY82 Criteria, 2.6% Fuel Escalation Average 1981 Commercial/Industrial Power Consumption Average 1981 Residential Power Consumption Cordova, Valdez, and Glennallen Low-Growth Load CEC Diesel Fuel Cost Hydroelectric Sites (Rev. 1) Hydroelectric Sites Small Hydroelectric Combination 3, Cordova Low-Growth Scenario Small Hydroelectric Combination 4, Cordova Low-Growth Scenario Small Hydroelectric Combination 5, Cordova Low-Growth Scenario 1.0 EXECUTIVE SUMMARY The purpose of the Interim Feasibility Assessment is to formulate the optimal plan for providing electric power to the City of Cordova. This addendum provides supplementary information to the Cordova Power Supply Interim Feasibility Assessment, dated June 1982, and was developed as a result of comments to the June Report. The more competitive generation alternatives were re-evaluated based on a lower electrical demand forecast than previously considered in the Interim Feasibility Assessment. The revised low demand forecast is consistent with the low demand forecast of R. W. Retherford Associates’ Reconnaissance Study of Energy Requirements and Alternatives for the City of Cordova, June 1981; and also a recent Addendum to the Battelle, Pacific Northwest Laboratories’ Railbelt Electric Power Alternative Study: Evaluation of Electric Energy Plans, February 1982. The load forecasts which are used to evaluate generation alternatives do not include space heating by electricity, because in the near term, the cost of generating electricity by hydroelectric power or other means is not expected to be sufficiently different from current power costs to cause economic incentives to change space meeting methods. This addendum provides assessments of potential hydroelectric sites in the Copper River Basin downstream of Taral and a wood fired powerplant in Cordova which were suggested at public meetings and in correspondence received from the Eyak natives. The economic life of the diesel waste heat options was extended and the cost of diesel fuel was lowered to reflect the October 1982 price in Cordova. The diesel alternative present worth costs were recomputed. The operation and maintenance costs for each hydroelectric site and its associated transmission line have been revised for use in the economic evaluations based upon recent Power Authority experience for the Solomon Gulch Hydroelectric Project. In addition, cost estimates for land and damages and reservoir clearing have been included with a 30 percent STONE & WEBSTER A contingency for all hydroelectric power alternatives. Five months of field environmental and geologic investigations have been conducted at the Silver Lake site over the summer of 1982. These studies have confirmed that there are no unmitigatable environmental or geologic problems that would prevent hydroelectric development at the site. In fact, site conditions at Silver Lake appear quite favorable. Field data collected to date is contained in Volume 2. The Present Worth costs and the Benefit/Cost Ratios of the Best Generation Alternatives are included in Table 1.0-1. The small hydroelectric alternative has the lowest present worth cost for the one case of the lowest electrical demand projection and supplying the Cordova load only. However, Silver Lake still remains the "best cost" alternative when considered on a regional basis, even under the most conservative load growth assumptions. Preparation of a final feasibility study of Silver Lake is recommended based on our findings. 1-2 STONE & WEBSTER a» TABLE 1.0-1 PRESENT WORTH COSTS AND BENEFIT/COST RATIOS BEST GENERATION ALTERNATIVES PRESENT WORTH COST (MILLIONS OF $) BENEFIT /COST RATIOS3 LEVEL 2 LEVEL 2 CORDOVA LOAD PROJECTIONS: LOW MEAN (HIGH) LOW MEAN (HIGH) CASES 1. Diesel Base Case (w/o Waste Heat Recovery) * 117.8 141.9 176.2 1.00 1.00 1.00 2. Diesel Base Case (w/Waste Heat Recovery) * : 117.2 140.6 174.9 1.01 1.01 1.01 3. Coal-Fired Option 123.0 140.8 166.5 0.96 1.01 1.06 4. Small Hydro & Transmission 89.3 118.0 138.3 1.32 1.20 1.27 5. Silver Lake & Transmission 103.31 104.61 123.12 1.14 1.36 1.42 6. Silver Lake & Transmission Sale of Excess Power to CVEA** 67.32 85.62 113.22 1.45 1.49 1.51 * Diesel Fuel (Oct, 1982) - $1.0695/Gallon, Fuel Escalation 2.6% per APA FY 82 Criteria ## Valdez-Glennallen Low-Demand Load Benefit calculated using CVEA diesel generator fuel rate of 0.0769 gallons/kWh produced and the 1982 CVEA diesel fuel cost of $1.03/gallon (escalated at 2.6% per year). 1 9 MW installed capacity 2 15 MW installed capacity 3 See Tables 10.0-1, 10.0-2, and 10.0-3 for calculation of Benefit/Cost ratio STONE & WEBSTER A 2.0 INTRODUCTION The study purpose remains unchanged. Additional generation alternatives have been investigated, including a wood-fired power plant in Cordova, and 13 hydroelectric sites within the Copper River Basin downstream of Taral. The study methodology and the study assumptions and contraints as described in the Interim Feasibility Assessment also remain unchanged. STONE & WEBSTER A 3.0 EXISTING POWER SUPPLY SYSTEM This section remains unchanged. STONE & WEBSTER A 4.0 ELECTRICAL ENERGY FORECASTS To supplement the Electrical Energy Forecast previously prepared for the Interim Feasibility Assessment, a new section 4.4 has been prepared which presents further discussion of Cordova and the Cordova-Valdez-Glennallen Region future electric requirements. STONE & WEBSTER A 4.4 REVIEW OF JUNE 1982 ELECTRICAL ENERGY FORECASTS 4.4.1 General In order to further investigate the sensitivity of the better generation alternatives over a more conservative range of load forecasts: revised low, mean, and high demand forecasts were prepared for Cordova (CEC), the Valdez-Glennallen Region (CVEA). The two primary references for the Electrical Energy Forecast are R. W. Retherford Associates Reconnaissance Study of Energy Requirements and Alternatives for the City of Cordova, June 1981; and the Battelle, Pacific Northwest Laboratories Addendum to the Railbelt Electric Power Alternative Study: Evaluation of Electric Energy Plans, September 1982. Stone & Webster personnel met with Battelle personnel in Battelle's offices in November to review in detail their assumptions and bases for their revised forecasts which are being published in their Addendum to the Railbelt Electric Power Alternative Study. Essentially, the new forecasts are based on rather bleak economic conditions, where oil revenues to the state are down, and corresponding state spending will also be reduced to avoid deficit spending. The forecasts upon which Stone & Webster has re-evaluated its energy alternatives are based on, or are consistent with, the Battelle forecasts. Corvoda's mean and high rates of growth and Battelle's Valdez-Glennallen mean rate of growth were previously considered in the Interim Report. We have used the low forecast of Retherford's Reconnaissance Study report for evaluating those generation alternatives designed for Cordova's load only and a Valdez-Glennallen low-growth case having a power demand lower than Battelle's, Plan 1B, Glennallen-Valdez nonsustainable government spending low-growth forecast. The Valdez-Glennallen low-growth forecast was combined with the Cordova low-growth forecast to evaluate the sale of excess power beyond Cordova's requirements to Valdez-Glennallen. The Cordova low-growth load forecast has as a compound rate of growth in peak demand of 4.4 percent and compound growth rate in average annual energy usage of 2.6 percent. These rates are considerably below Cordova's recent 4-2 STONE & WEBSTER A growth trends. The Valdez-Glennallen low-growth peak demand forecast has a compound growth of 2 percent annually, and compound growth in average annual energy usage of 2 percent. This growth is less than the Battelle's Glennallen-Valdez, Plan 1B, low economic scenario or nonsustainable gavernment spending scenario, and is: about 40 percent lower than recent post-pipeline era statewide electrical growth history. The Valdez-Glennallen low-growth load forecast was chosen by Stone & Webster to show sensitivity of the generation alternatives to lower rates of growth than any load forecast projected by Batelle. We believe this sensitivity test to be quite conservative and the lowest limitation on project economics. The cost of space heating by electricity versus propane, oil or wood alternatives is further addressed to clarify its potential effect on the Cordova demand forecast. In addition, the impact of the conservation measures discussed in Retherford's Reconnaissance Study and raised in comments to the Interim Report, are addressed. 4.4.2 Space Heating Cordova presently has a summer peaking electric load caused by fish industry canning operations, and the related influx of workers during the summer months. An increase in space heating would not increase Cordova's peak demand. Glennallen-Valdez has a winter peaking electric load and electric space heating would increase the winter peak. In both locations, the energy demand would increase should electric space heating occur. The cost of space heating by diesel-generated electricity is unattractive at present due to the high cost of power by this fuel. For consistency and conservatism, we have reanalyzed the more competitive generation alternatives based upon load forecasts that do not include space heating. However, there may be a potential for some electric space heating in the future if hydroelectric power is developed, and the resultant power costs stabilize over time. Figure 4.4-1 shows the present day Cordova fuel costs expressed in ¢/kWh, escalated at 2.6 percent in accordance with the Power Authority's FY-82 - STONE & WEBSTER A economic criteria. The cost per gallon of the fuels, both present day and projected to 2002, are as follows: CORDOVA FUEL COST 1982 2002 Fuel Cost per Gallon Cost per Gallon Remarks Propane $1.97 $3.29 Diesel 1.07 1.79 (Cost to CEC includes delivery) #1 Oil 1.45 2.43 (0-100 gallons) 1.35 2.25 (100-200 gallons) 1.38 2.22 (200-300 gallons) 1.29 2.15 (300 up gallons) #2 Oil 1.38 2.30 (0-100 gallons) 1.28 2.15 (100-200 gallons) 1.24 2.07 (200-300 gallons) 1.23 2.05 (300 up gallons) NOTE: All costs rounded to the nearest whole cent Propane, which has the highest per gallon price, is presently used in trailers and mobile homes in Cordova (32 percent of the housing) for heating and cooking. Retherford's Reconnaissance Study projects that propane will continue to be used as follows: Propane Use in Cordova Estimated use in 2000 1979 (actual) Low Medium High 65,250 gallons 91,000 111,000 124,000 gallons The corresponding equivalent cost of propane in 2002 based upon 2.6 percent escalation is approximately 19 cents per kilowatt hour. To graphically demonstrate the impact of hydroelectric energy on consumer electric costs, Figure 4.4-2 shows the consumer cost of electricity for the Silver Lake development based on the sale of excess energy to CVEA (Valdez and Glennallen) and no state financing subsidies for the project. This figure indicates that electric costs will be at or below 19 cents per kilowatt hour and there is a potential for conversion from propane to other heating alternatives in trailers and mobile homes before the year 2002. The lowest cost fuel for space heating is oil. However, the actual selection of a 4-4 STONE & WEBSTER A heating option is also based upon the capital cost and life of heating equipment, convenience, expected extent of usage, and other factors which will influence a consumer's decisions. 4.4.3 Conservation Measures Retherford's Reconnaissance Study identified and recommended a number of conservation methods for the City of Cordova which, if implemented, would lower heating oil consumption, but have virtually no impact on electrical demands. Based on Cordova's current usage, it is obvious that significant conservation has already occurred. Unit commercial and residential usage in Cordova as shown in Figures 4.4-3 and 4.4-4 are low when compared with other Alaskan communities with cheaper power. The high cost of electric energy has made conservation a necessity in Cordova. It will be difficult to force the Cordova residents to further electrical conservation as their consumption is well below the state average. Should the cost of power reduce, negative conservation could take place, increasing per customer consumption as shown for other Alaskan communities on Figures 4.4-3 and 4.4-4. 4.4.4 New and Proposed Events Potentially Affecting Forecasts The load forecast assumed the Chugach Fisheries would change over from self-generation to purchased power from the Cordova Electric Cooperative (CEC) in 1982, adding about 1MW to the CEC system peak demand. Mr. D. Bechtel of CEC advised that Chugach Fisheries began purchasing power from CEC on June 30, 1982. Their peak demand to date has been 360 kW. On September 22, 1982, Mr. P. Lovett, Cordova's City Manager, indicated that a shift from canning to freezing is expected for the fishing industry. He anticipates three freezers will be added within the next five years. Presently, the canning operations burn fuel oil to produce steam for the canning process. Freezing will be electricity dependent and will increase the projected electrical demands for CEC above that projected in the low forecast. 4-5 STONE & WEBSTER A 4.4.5 Cordova Forecast The Cordova forecasts use growth projections from the study "North Gulf of Alaska, Petroleum Development Scenarios, Local Socioeconomic Impacts: Alaskan OCS Socioeconomics Studies Program, Technical Report 33, October 1979." The OCS (Outer Continental Shelf) study developed three growth scenarios, including a base case. The base case assumed growth due to the fishing industries and services with no offshore oil development. The high-growth scenario assumed a significant level of petroleum discoveries and the completion of an offshore terminal that would be staffed from the Cordova area. Under the high-growth scenario, the probability of such a significant level of discovery was assumed to be 5 percent. In contrast to the low probability contingent upon a petroleum discovery, the mean-growth scenario represents offshore exploration with limited offshore development. This case has a 50 percent probability of occurance. Tables 4.4-1, 4.4-2, and 4.4-3 show the Cordova low, mean and highest forecasts. The following is a summary of the energy forecasts assumptions for Cordova. Cordova Low-growth scenario assumptions ° Employment will grow at an annual rate of about 1.5 percent in the economic sectors of trade services and fishing. ° The trade and service sectors will increase by about 4.0 percent per year as tourism and recreation opportunities increase. ° Manufacturing employment, primarily processing, will increase by 1.5 percent per year. The growth will keep pace with estimated increases in fish harvests. - STONE & WEBSTER A Surface transportation is assumed to increase by only 2 percent per year. This employment will result from increases in tourism and recreation. Government employment will grow at a rate of only 1 percent per year. Secondary employment estimates are based on an _ employment multiplier of 1.47. This low multiplier is reasonable in view of the convenience to purchase goods and services in Anchorage. As the trade and commercial sectors of Cordova's economy grow, a higher multiplier can be expected as discussed in the OCS Study page 61. Population estimates are based on a population employment ratio of 2.0, the 1978 ratio. This ratio resulted in a _ forecasted population growth of 1,320 from 1981 to the year 2000 for the Cordova area. The low-growth scenario is used as the basis for change in the number of electric customers and the use per customer for the other growth scenarios. No OCS leasing. Half of the new growth for Cordova would come from new developments and improvements in the fish processing industry. Half would come through development of the local service sector. A shift from canning to freezing is considered with three freezers added over the next five years. 4-7 STONE & WEBSTER dD Cordova Mean-growth scenario assumptions ° Same as above, except expected growth is based on a weighted average of limited petroleum exploration and growth associated with staged development of offshore facilities and construction and operations of an offshore terminal. Retherford and the OCS study indicate that Cordova would provide family housing to support OCS work. Population Percentage Low Median Diff. of Low 1982 2,488 2,499 ital 0.4% 1985 Z OLS 2,639 26 1.0% 1990 2,850 3538 488 17.1% 1995 3,154 3,695 541 Niaz 2000 Soe 4,073 552 15.7% This table was prepared on the basis that each OCS worker is part of a family of three (below the national average) with the OCS and Retherford forecasted population increases.” OCS Pop. OCS Workers Increase (based on 3 Member Family) 1982 5 1 4 1985 26 9 1990 488 163 1995 541 181 2000 552 184 In 1990 the OCS field investigations would enter into a limited drilling program accounting for the population increase. This level of OCS effort is relatively small and would relate to a very limited OCS work effort. The Retherford and OCS weighted average approach provides reasonable labor values. 4-8 STONE & WEBSTER A Cordova Highest-growth scenario assumptions ° Same as low-growth scenario assumptions, except expected growth is based on a full production OCS development. ° Based upon OCS high-growth scenario. ° Assumes a significant level of OCS petroleum discoveries. ° Assumes completion of an offshore oil terminal. ° Projects a 7.7 percent energy growth and 7.6 percent peak demand growth. Level 2 (High) growth scenario assumptions ° Due to the 5 percent probability for an OCS significant oil discovery, SWEC has prepared an intermediate high-growth projection which provides a rate of growth between the mean- and highest-growth scenarios which is more consistent with the actual CEC generation experienced since 1977. The general ‘approach of the forecast for Cordova was to review the existing energy and peak load studies for reasonableness to ensure that any unique situations are identified and appropriately considered. Interviews and discussions were held to identify the current conditions as of November 1982, and likely possible changes in energy requirements and peak demands. Based on the interviews and information from source documents, the existing studies of energy consumption and peak demands were modified as deemed appropriate to reflect the information obtained. Further, we reviewed the actual annual maximum demand, and annual energy generation for the Cordova 4-9 STONE & WEBSTER A Electric Cooperative (CEC) as furnished by Mr. D. Bechtel: Sales Generation Peak Demand Annual Energy Annual Energy Year kW MWh MWh 1977 2,750 14,354 13,754 1978 3,150 15,660 15,060 1979 3,500 16,494 14,622 1980 3,730 16h 151 14,665 1981 3,750 17,474 16,859 1982 4,000 Not Available Not Available Peak demand has grown from 1977 to 1982 at 6.4 percent and annual energy from 1977 to 1981 has grown at 4.2 percent. The highest growth load forecast projects a 7.7 percent energy growth and a 7.6 percent peak demand growth which is consistent with the 8 percent growth rate forecast by CEC. We have reviewed Retherford's assumptions and approach for the Reconnaissance Study load forecasts for Cordova's Power Requirements, and as discussed, find them to be reasonable. We do not believe CEC's growth will continue at nearly 8 percent unless there are significant oil, gas, or mineral discoveries, or outside influences which are presently unforeseen, and have a low probability of occurance. SWEC believes that an intermediate electric load growth will occur in the Cordova-Valdez-Glennallen area should the price of electricity to the consumer be reduced as shown in Figures 4.4-3 and 4.4-4. Since the degree of state participation in a project is uncertain, it is conservative to assume no state participation, little or no reduction in power cost, and, therefore, a low growth rate. Questions were raised concerning the potential for peak-shaving strategies. Cordova's load is currently summer peaking due to fish canning, and the predicted change from canning to freezing will probably cause an increase in peak demand growth. Peak shaving, except by hydroelectric operations storing water during off-peak times, is unacceptable because it would have a direct negative impact on the Cordova economy. 4-10 STONE & WEBSTER A 4.4.6 Valdez-Glennallen Forecast The actual Copper Valley Electric Association, Inc. (CVEA) records were obtained to document the recent demand growth between 1976-1981: Valdez-Glennallen Sales Generation Peak Demand Annual Energy Annual Energy Year kW GWh GWh 1976 65975 33.9 40.0 1977 8,990 42.4 48.7 1978 8,750 38.8 45.0 1979 7,695 36.5 42.6 1980 8,180 37.4 45.1 1981 8,350 39.4 46.3 Based upon the monthly peak demand records of CVEA, the peak demand occurs in December or January. In 1978 and 1979 the demand and generation dropped and rose again in 1980 and 1981. The trend between 1979 and 1981 would indicate a 2.8 percent growth in peak demand and a 2.8 percent growth in annual energy. Battelle, Pacific Northwest Laboratories prepared a number of load growth forecasts for Valdez-Glennallen as part of the Railbelt Electric Power Alternatives Study: Evaluation of Railbelt Electric Energy Plans, September 1982 draft. Several documents have been prepared in conjuntion with Battelle's study which are presently being reviewed by the State of Alaska. The Battelle forecasts use growth projection information developed by the Institute of Social and Economic Research (ISER). The Battelle Plan 1B forecasts were compared on the basis of compound growth for the period between 1980 and 2010. The following table shows the annual energy forecast for Plan 1B, low, nonsustainable government spending (NSGS), medium, and high-growth scenarios, and the average compound growth rates for each scenario. 4-11 STONE & WEBSTER A Annual Energy Forecast (Gwh) Valdez-Glennallen Year Low NSGS Medium High 1980 39 39 39 39 1985 42 47 47 55 1990 54 62 92 757 1995 69 79 110 782 2000 85 94 130 809 2005 104 108 155 844 2010 128 124 186 887 Average Compound Growth Rate (1980-2010) Ave. Compound Probability (Gwh) (Gwh) Rate of Occurance Case 1980 2010 (Percent) (Percent) Low 39 128 4 90-95 NSGS 39 124 4 Not Provided Medium 39 186 5 50 High 39 887 11 5-10 The average compound growth rate for Battelle's low and nonsustainable government spending cases is above the actual 2.8 percent growth in generation between 1979 and 1981. To avoid using a forecast which has a higher growth rate than that actually experienced in Valdez-Glennallen in recent years, Stone & Webster has decided to use a low-growth load forecast of 2 percent through the years 1982 to 2002. Such a conservative forecast should demonstrate the economic sensitivity of the projects studied to the potential for a lower than expected growth rate. The Battelle Plan 1B, low and medium growth scenarios have a reasonable probability of occurance and are used by Stone & Webster as_ the Valdez-Glennallen medium and high load forecasts. The Battelle Plan 1B high demand forecast has a low-probability of occurance and is not used. The Battelle forecasts were adjusted to reflect actual CVEA generation in 1980 and 1981. 4-12 STONE & WEBSTER Xd Table 4.4-5, shows the Valdez-Glennallen low, mean and high-growth load forecasts as recommended by Stone & Webster. The following is a summary of the energy forecast assumptions for Valdez-Glennallen. Valdez-Glennallen Low-growth scenario assumptions ° The aggregate growth rates would slow from the 2.8 percent rate experienced between 1979 and 1981 to a 2 percent future average compounding rate of growth. The rate of growth in employment in all economic sectors will slow causing limited growth in secondary employment. ° No effect of the recent reduction in consumer electric rates caused by Solomon Gulch generation. ° The 2 percent peak demand and annual energy growth rate was selected to be below the state average annual energy generation growth between 1978 and 1981 of 3.54 percent. Valdez-Glennallen Mean-growth scenario assumptions ° Low growth is the basic sector activity in the private economy. ° Growth in state government spending at a rate which maintains the initial per capita level. ° Population growth occurs during the mid1980's resulting from the construction of the gas pipeline but slows considerably in the decade of the 1990's. The employment peaks in the late 1980's when the pipeline is nearly complete and is followed by a period of out-migration as the natural increase in the resident population generates larger yearly increases in the labor force than jobs provided by the economy. The late 1980's population projection corresponds with the 1999 level. mn STONE & WEBSTER A Three variables were used by ISER to monitor the credibility of the economic projections. ii The ratio of civilian employment to population increases in the late 1980's and then falls in the early 1990's. The subsequent decline in this ratio does not return to its value, indicating that employment as a proportion of its population is continuing its historical trend upwards. 2. The ratio of the Alaskan to the average U.S. price level is projected to decline with time. This is also consistent with historical trend. SF The ratio of real personal income per capita in Alaska and the U.S. is likewise projected to decline over time in a return to the long-standing historical relationship. This trend is reversed in the mid1980's, due to the construction activity. The employment mix on the structure of the economy measured by employment remains influenced by government spending even at a slower growth in government spending from the high-growth scenario. The slower rate of government spending results from the associated slow growth in the private sector basic activities and the continued strong presence of the federal government. The number of households rises corresponding to the gas pipeline construction activity during the mid1980's and then falls during the period of out-migration. Population projections were based upon the Valdez-Chitina-Whitier region which in 1979 had a population of 7,013 with corresponding employment of 2,320. This represents a population to employment ratio of 3.02. nai STONE & WEBSTER A ° Manufacturing for local Alaskan use which excludes expansion of existing production as well as new manufacturing is 1 percent of total employment. ° Fisheries has no new development. ° Food processing has no new development. ° Expansion of timber, lumber and pulp industries has little effect on region. ° A 0.5 percent increase in Federal civilian employment with the military remaining constant. ° A 2 percent tourism employment growth. ° State government per capita spending remains unchanged, but grows with population, prices and incomes. ° This case has a 90-95 percent probability that actual developments will equal or exceed this projection. Valdez-Glennallen High-growth scenario assumptions ° Moderate growth in basic sector economic activity. ° Moderate growth in state government expeditures. ° 1980's growth pattern predicated on the decade of growth in the 1970's followed by a decade of slightly slower but more stable growth. ° Cyclical growth in the 1980's is attributable to the simultaneous construction of several large construction projects resulting in a rapid employment and population buildup, followed by a few years of slack activity as the economy "fills in." 4-15 STONE & WEBSTER d»& The proportion of total employment that is government related falls, while private sector employment grows. The proportion of the basic sector employment increases from 23 to 25 percent. The proportion of the support sector employment increases from 39 to 43 percent. The military and native segments of the population decline as a proportion with the total population over the planning period. A rapid growth in civilian non-native households nearly doubling in total within the planning period. Average household size and the rate at which household size diminishes varies with the status of the head of household. Native households are larger than civilian non-native household or military households. ~ State revenues exceed expenditures consistently through the planning period and the permanent fund and general fund balances increase. Population projections were based upon the Valdez-Chitina-Whitier region which had a 1979 population of 7,013 with corresponding employment of 2,320. This represents a population to employment ratio of 3.02. Three variables were used by ISER to monitor the credibility of the economic projections. ee The ratio of civilian employment to population increases in the late 1980's and then falls in the early 1990's. The subsequent decline in this ratio does not return to its value, indicating that employment as a proportion of its population is continuing its historical trend upwards. 4-16 STONE & WEBSTER dM ae The ratio of the Alaskan to the average U.S. price level is projected to decline with time. This is also consistent with historical trend. Ss The ratio of real personal income per capita in Alaska and the U.S. is likewise projected to decline over time in a return to the long-standing historical relationship. This trend is reversed in the mid1980's, due to the construction activity. Agriculture, predicated upon various state and Federal policies, and market conditions, has an 8 percent employment growth rate. Fisheries industry has a 50 percent replacement to bottom fishing. Employment expected to be constant. Slow development of non-Prudhoe Bay on-land oil fields. Outer Continental Shelf (OCS) activity has the sale of 3 leases after 1985; 7 billion bbl are discovered and developed. Limited population increase with Valdez providing family housing to support OCS work. Hardrock mining will have a 1 percent growth of employment Food processing development based on growth of fisheries activity. No growth is expected in this sector only possible replacement of canning operations by freezers. Manufacturing for local Alaskan use which includes expansion of existing production as well as new manufacturing is 2 percent of total employment. A 0.5 percent increase in civilian employment with military remaining constant. 4-17 STONE & WEBSTER A ° State government per capita spending increases at the same rate as per capita income growing with population, prices and incomes. ° A 4 percent tourism employment growth. The general approach of the forecast for Valdez-Glennallen was to review the existing energy and peak load studies for reasonableness to ensure that any unique situations are identified and appropriately considered. Discussions were held with Battelle personnel during November 1982 and likely changes to the draft version of the Railbelt Electric Power Alternative Study: Evaluation of Railbelt Electric Energy Plans were discussed. Utilization of a lower growth forecast than Battelle's Plan 1B low economic growth or nonsustainable government spending scenarios resulted. Battelle has proposed an Addendum to the Executive Summary presenting the effects of lower oil prices as have been experienced during that last nine months. This addendum proposes lower rates of economic growth resulting in a lower electrical growth forecast. The SWEC Valdez-Glennallen low-growth demand forecast is consistent with these lower rates of economic’ growth. The forecast of Valdez-Glennallen power requirements are shown on Table 4.4-5. 4.4.7 Forecast Utilization A regional evaluation was performed which included the sale of excess Silver Lake power to Valdez-Glennallen (CVEA). For this evaluation, the load projections for Valdez-Glennallen were used. The Valdez-Glennallen load projections and the additional energy requirements over Solomon Gulch output are shown on Table 4.4-6. The combined Cordova-Valdez-Glennallen electrical demand forecasts are presented in Table 4.4-7. When the Cordova load requirement is added to the CVEA load projections, it is clear that a significant load will develop beyond Solomon Gulch capacity. This implies a regional need for additional generating capacity, such as Allison Lake and Silver Lake. This is illustrated in Figure 4.4-5 which shows the relationship between Cordova low-growth (CEC) and Valdez-Glennallen low-growth (CVEC) load projections, Solomon Gulch capacity, and Silver Lake capacity. 4-18 STONE & WEBSTER a Based upon the economic results to date, Silver Lake remains economically superior to Allison Lake and it would be in the best interest of the region to build Silver Lake initially followed by Allison Lake. Silver Lake has an additional regional advantage, as recommended in the interim report, due to the large storage available at Silver Lake. The combined operations of Silver Lake and Solomon Gulch may further increase combined firm power production. Lastly, previous reports have discussed the ALYESKA Pressure Reducing Turbine (PRT) alternative as a possible energy source for CVEA. We have received a letter from Alyeska, dated October 11, 1982, in which they state "Alyeska Engineering Department has just completed a study of the relative merits of a PRT. Based on the results of this study, Alyeska does not " believe that installation of a PRT is appropriate at this time. Therefore, the PRT is at this time not a viable energy source. 4-19 STONE & WEBSTER A TABLE 4.4-1 LOW ELECTRICAL LOAD FORECAST CITY OF CORDOVA YEAR: 1980 A. Number & Type of Consumer: 1. Residential 719 2. Small Commercial ( 50 kVA) 2u7 1 3. Large Commercial (50 to 350 kVA) 7 4. Large Commercial ( 350 kVA) 3 5. Public Lights, etc. 2 6. Unaccounted Power 10% B. Average Consumption (kWh) Per Year Per Consumer 1. Residential 5 ,833 2. Small Commercial 20,615 2 3. Large Commercial 280,000 2 4. Large Commercial 1,212,000 2 5. Public Lights, etc. 9,000 6. Unaccounted Power 12% C. Total Energy (103 MWh): 16.7 D. Maximum Demand (MW): 3.4 3 Increase of 1% a year Increase of 2% a year Increase of 4% a year Addition of 500 kW load Frwnhr 1985 1990 756 795 260 273 8 8 3 3 2 3 10% 10% 5,800 5,500 22,750 25,100 309 ,000 341, 000 1,340,000 1,477,000 9,000 9,000 10% 10% 18.5 20.2 4. 5.0 werrewo 5,500 27,750 377,000 1,631,000 1, 9,000 10% 24.8 6.6 4 2000 878 301 10 10% 5,300 30, 600 416,000 800,000 9, 000 10% 27.8 8.0 2002 * 29.2 8.4 Reference: Final Report: Reconnaissance Study of Energy Requirements and Alternatives for Cordova, Robert W. Retherford Associates, Anchorage, Alaska, June 1981. * Projected values based upon Retherford's assumptions. STONE & WEBSTER A YEAR: 1980 1985 1990 1995 2000 A. Number & Type 7 of Consumers: 1. Residential 719 833 3 897 4 gh2 991 2. Small Commercial ( 50 kVA) 2u7 272 300 3 323 348 3. Large Commercial if 10 alk 13) 17. ( 50 to 350 kVA) 4. Large Commercial ( 350 kVA) 3 4 4 5 5 5. Public Lighting, etc. 2 4 5 6 6 6. Unaccounted Loads (4%) ie. 12 10 12 10 (city, plant & losses) B. Average Consumption (kWh) Per Consumer Per Year 1. Residential 5,833 6,000 5,800 5,800 6, 0002 2. Small Commercial 20,615 21,500 23,000 24,500 27,000 3. Large Commercial 280,000 335,000 388,000 450,000 521,000 4. Large Commercial 1,212,000 1,368,000 1,510,000 1,520,000 1,680,000 5. Public Lighting, etc. 9,000 9,000 9,000 9,000 9,000 C. Total Energy Consumption (103 MWh): 16.7 22.0 24.7 30.1 35.9 D. Maximum Demand (MW): 3.4 1 5.0 5.8 TH 8.6 Note TABLE 4.4-2 MEAN ELECTRICAL LOAD FORECAST s: 1 2 3 m Refe A growth rate of 3% is assumed during this period. A growth rate of 2% is assumed during this period. A growth rate of 1.5% is assumed during this period. A growth rate of 1% is assumed during this period. ° ooo0o0o0 CITY OF CORDOVA Additional Data: Addition 1,000 kW, 1.6 MWh load of Chugach Fisheries to CEC in 1983. 2002 * 38.3 9.2 Addition of a 600 kW, 1 GWh future customer in 1992. Increase in transmission network in 1983. Decrease due to system improvements in 1986. Expansion of transmission network in 1983. Transmission line improvements in 1996. Drop due to rising cost in 1986. rence: Final Report: Reconnaissance Study of Energy Requirements and Alternatives for Cordova, Robert W. Retherford Associates, Anchorage, Alaska, June 1981. * Projected values based upon Retherford's assumptions. STONE & WEBSTER A TABLE 4.4-3 HIGHEST ELECTRICAL LOAD FORECAST CITY OF CORDOVA (See Table 4.4-4 for Cordova Level 2 (High) Growth Demand) YEAR: 1980 1985 1990 A. Number & Type of Consumer: 1. Residential 719 1 834 966 2. Small Commercial ( 50 kVA) 247 286 eS 3. Large Commercial (50 to 350 kVA) 7 10 15 4, Large Commercial ( 350 kVA) 3 4 6 5. Public Lights, etc. 2 4 6 6. Unaccounted Power 10% 10% 10% B. Average Consumption’ (kWh) Per Year Per Consumer 1. Residential 5,833 2 7,100 8,600 2. Small Commercial 20,615 2 25,000 30,500 3. Large Commercial 280,000 2 340 , 600 415,000 4. Large Commercial 1,212,000 2 1,475,000 1,794,000 5. Public Lights, etc. 9,000 9,000 9,000 6. Unaccounted Power 12% 10% 10% C. Total Energy (103 MWh): 16.7 26.3 39.0 D. Maximum Demand (MW): 3.4 3 5.7 8.3 1 3% increase every year. 2 4% increase in consumption. 1995 1,120 332 18 10% 10 ,500 37, 100 504, 000 2, 183,000 9,000 10% 58.2 11218) 2000 1,298 385 20 10 10 10% 12,750 45,000 614, 000 2,656,000 9, 000 10% 80.0 16.5 2002 * 90.1 3 6% increase + large loads (1 MW in 1983 for Chugach Fisheries & 350 kW per customer thereafter). Reference: Final Report: Robert W. Retherford Associates, Anchorage, Alaska, June 1981. * Projected values based upon Retherford's assumptions. Reconnaissance Study of Energy Requirements and Alternatives for Cordova, STONE & WEBSTER jd FORECAST OF Cordova Low-growth (2.7% Growth) Cordova Mean-growth - Level 0 (3.8% Growth) Cordova Level 2 (High) growth (5.3% Growth) Cordova Highest-growth (7.7% Growth) Cordova Low-growth (4.3% Growth) Cordova Mean-growth - Level 0 (4.8% Growth) Cordova Level 2 (High) growth (6.2% Growth) Cordova Highest-growth (7.6% Growth) Note: TABLE 4.4-4 CORDOVA POWE R REQUIREMENTS Total Energy (GWh) 1982 1987 1992 1997 2002 17.3 19.7 23.0 26.1 29.2 18.2 22.3 27.7 31.8 38.3 18.2 24.4 34.1 41.1 50.9 20.5 31.4 46.7 66.9 90.1 Peak Demand (MW) 1982 1987 1992 1997 2002 3.6 4.4 5.6 Gue 8.4 2.0 5.3 6.8 7.9 Sia 3.6 5.3 7.7 9.7 12.0 4.3 6.7 9.7 13.7 18.7 Cordova Highest-growth forecast is based upon a 5% probability of occurance which is relatively remote and, therefore, was not used to evaluate generation alternatives. STONE & WEBSTER A . TABLE 4.4-5 FORECAST OF VALDEZ-GLENNALLEN POWER REQUIREMENTS Total Energy (GWh) 1982 1987 1992 19977, 2002 Valdez-Glennallen Low-growth 47.2 Sy seal Sed! 63755) 70.1 Valdez-Glennallen Mean-growth 47.2 49.9 60.0 7534 92.6 Valdez-Glennallen High-growth 47.2 657515 99.2 118.0 140.0 Peak Demand (MW) 1982 1987 1992 1997 2002 Valdez-Glennallen Low-growth 8.5 9.4 10.4 11.4 12.6 Valdez-Glennallen Mean-growth © $.5 10.2 13.2 16.6 20.6 Valdez-Glennallen High-growth 85: 14.4 22.6 26.6 3110) Notes: 1. Valdez-Glennallen Mean-growth electrical forecast is based upon Battelle's Plan 1B, Low-growth scenario. 27 Valdez-Glennallen High-growth electrical forecast is based upon Battelle's Plan 1B, Mean-growth scenario. STONE & WEBSTER A 1982 1987 1992 1997 2002 1982 1987 1992 1997 2002 1982 1987 1992 1997 2002 TABLE 4.4-6 EFFECT OF SOLOMON GULCH ON VALDEZ-GLENNALLEN LOAD FORECASTS Low Load Total Energy Forecast Low Load, Solomon Gulch Additional CVEA GWH Output, GWH Energy Required, GWH 47.2 41.0 6.2 52.1 41.0 11.1 57.5 41.0 16.5 63.5 41.0 22.5 70.1 41.0 29.1 Mean Load Total Energy Forecast Mean Load, Solomon Gulch Additional CVEA GWH Output, GWH Energy Required, GWH 47.2 41.0 6.2 49.9 41.0 8.9 60.0 41.0 19.0 Tih 41.0 34.4 92.6 41.0 51.6 High Load Total Energy Forecast High Load, Solomon Gulch Additional CVEA GWH Output, GWH Energy Required, GWH 47.2 41.0 6.2 65.1 41.0 24.1 99.2 41.0 58.2 118.0 41.0 77.0 140.0 41.0 99.0 STONE & WEBSTER A TABLE 4.4-7 CORDOVA-VALDEZ-GLENNALLEN COMBINED LOAD FORECAST Total Energy (GWh) 1982 1987 1992 1997 2002 Combined Low-growth 64.5 71.8 80.5 89.6 S93 Combined Mean-growth 65.4 W2ee B7e7. 107.2 130.9 Combined High-growth 65.4 89.5 133.3 159.1 190.9 Peak Demand (MW) 1982 1987 1992 1997 2002 Combined Low-growth : ray 13.8 16.0 18.6 21.0 Combined Mean-growth 12.1 | 20.0 24.5 29.8 Combined High-growth rat G7) 30.3 36.3 43.0 STONE & WEBSTER A A1082036 PROPANE ENERGY COST ¢/kWh * 1982 DOLLARS HEATING OIL #1 HEATING OIL #2 * INCLUDES 70 % FURNACE EFFICIENCY Figure 4.4-1_ CORDOVA SPACE HEATING FUEL ESCALATION, APA FY82 CRITERIA, 2.6% FUEL ESCALATION STONE & WEBSTER A A1082037 PROPANE SILVER LAKE HYDRO 1982 DOLLARS * = = x = o KE a ° Oo > Oo a w 2 w HEATING OIL #1 HEATING OIL #2 2000 * INCLUDES 70 % FURNACE EFFICIENCY Figure 4.4-2 CORDOVA CONSUMER SPACE HEATING ALTERNATIVE COSTS, SILVER LAKE — 15 MW CAPACITY — EXCESS POWER SOLD TO CVEA, CORDOVA LOW-GROWTH LOAD, VALDEZ — GLENNALLEN LOW-GROWTH LOAD, p NO STATE FUNDING, APA FY82 CRITERIA, 2.6% FUEL ESCALATION STONE & WEBSTER A1082013 SOUTH CENTRAL REGION STATE AVERAGE e VALDEZ (PRE-SOLOMON GULCH) @ SEWARD CORDOVA REFERENCE: ALASKA ELECTRIC POWER STATISTICS 1960 THROUGH 1981 ALASKA POWER ADMINISTRATION, U.S. DEPARTMENT OF ENERGY 7th EDITION, AUGUST, 1982 : | c w = ° Ee a 2? o c wi a 2 Q - a = 2 a 2 Q oO a Ww = o a > a c < Ww > wi Oo < c Wu > < 10 AVERAGE COST OF POWER TO THE CONSUMER — ¢/kWh (INCLUDES STATE SUBSIDY IF APPLICABLE) Figure 4.4-3 AVERAGE 1981 COMMERCIAL/INDUSTRIAL POWER CONSUMPTION STONE & WEBSTER A A1082012 ANCHORAGE STATE AVERAGE CORDOVA REFERENCE: ALASKA ELECTRIC POWER STATISTICS 1960 THROUGH 1981 ALASKA POWER ADMINISTRATION, U.S. DEPARTMENT OF ENERGY 7th EDITION,AUGUST, 1982 : | a er = ° FE a > oO c Ww a 2 ° - a = = a 2 Q o c WW = o a > a c < wi > WwW Oo < a wu > < 10 AVERAGE COST OF POWER TO THE CONSUMER — ¢/kWh (INCLUDES STATE SUBSIDY IF APPLICABLE) Figure 4.4-4 AVERAGE 1981 RESIDENTIAL POWER CONSUMPTION STONE & WEBSTER A LLozsoliw — SILVER LAKE HYDRO (46.7 GWh) — CORDOVA, VALDEZ AND GLENNALLEN COMBINED LOW-GROWTH LOADS — VALDEZ — GLENNALLEN LOW-GROWTH LOAD = = = > 9 i w 2 a a < 2 io E o wh = wa — SOLOMON GULCH HYDRO (41 GWh) — CORDOVA LOW-GROWTH LOAD Figure 4.4-5 CORDOVA, VALDEZ, AND GLENNALLEN LOW-GROWTH LOAD STONE & WEBSTER a 5.0 DIESEL GENERATION Several different diesel generation options were evaluated in the Interim Feasibility Assessment. The descriptions of the diesel system designs, operating procedures, etc., are unchanged. However, for this addendum, the diesel fuel price was reduced to the current 1982 (CEC) price, a new diesel option was developed for the Cordova Low-Growth Load, and the economic life of the diesel waste heat recovery system was labeled. The changes are described in the following sections. 5.5 FUEL SUPPLY AND COSTS In the Interim Feasibility Assessment, the early 1982 cost of diesel fuel trucked to the Eyak Lake diesel generating plant was $1.11 per gallon. A review of recent diesel fuel prices as shown on Figure 5.5-1 indicates that the rate of escalation of diesel fuel costs in Cordova between 1979 and 1982 was in excess of eight percent. However, in October of 1982, CEC was purchasing diesel fuel at $1.052 per gallon at the dock in Cordova and paying $0.0175 per gallon for transport to the plant for a total cost of $1.0695 per gallon. This recent price reduction resulted primarily from an oversupply of refined petroleum products in the U. S. markets. For the economic analyses in this addendum, the more recent diesel fuel price of $1.0695 per gallon was used in place of the higher value from the Interim Feasibility Assessment. In all economic evaluations, the diesel price was assumed to escalate at 2.6 percent as required by the Power Authority economic guidelines. In general, one penny's difference in fuel cost in 1982 is worth a little less than a million dollars in present worth cost over the 20-year economic evaluation period. 5.7 DIESEL VARIATIONS Variations of the diesel generation options were considered in the Interim Feasibility Assessment, including differences in Cordova's (CEC) demand and the use of diesel generator waste heat recovery for community building STONE & WEBSTER A space heating. In this addendum, an additional CEC load projection, the Cordova Low-Growth Load forecast, and changes to the waste heat recovery system were analyzed. 5.7.1 Variable Demands In addition to the CEC load projections described in the Interim Feasibility Assessment, a diesel generation option was developed for the Cordova Low-Growth Load forecast. This diesel plant, based on option DOl, was sized at 11 MW in the year 2002 in order to meet the projected 8 MW demand with sufficient reserve capacity. For this low-growth option, the capital cost expenditures (1982 dollars) for the diesel generation plant over time would be as follows: Year Capital Cost 1983 $6,839,000 1987 693,000 1992 2,400,000 1996 2,666,000 1999 : 1,333,000 The major work items performed would be similar to those described in Section 5.4.1 of the Interim Feasibility Assessment. Consistent with the previous work, the heat rate for the diesel generator units was assumed constant at 10,900 BTU per KWh generated. This heat rate was derived from operating reports of the existing Eyak diesel generating plant and performance specifications for differing sizes and manufacturers of diesel generator sets. 5.7.2 Diesel Waste Heat For the Interim Feasibility Assessment, an analysis was performed to determine the value of waste heat recovery from the jacket water cooling systems of the diesel generator units. This energy would be used to heat community buildings in the vicinity of Eyak diesel plant. The Cordova public buildings that can be economically supplied by waste heat recovery are all located between a half mile to a mile from the Eyak plant. The buildings are listed on page 5-9 of the Interim Feasibility Assessment. 5-2 STONE & WEBSTER A Calculations were prepared of diesel waste heat availability, the distribution system design, and estimates of the capital cost and maintenance expenditures for the waste heat distribution system were made. The Power Authority requested a second analysis based on the following modifications to conditions assumed originally: 1. The life of the waste heat distribution system was changed from 10 years (Power Authority FY82 requirement) to 20 years (Power Authority FY83 requirement). 2. The 200°F waste heat water supply temperature remained unchanged, but the 80°F return temperature was increased to 120°F. This means that more water would have to be pumped for a given exchange of heat in the buildings. 3. System flow rates, pumping power requirements, etc., were adjusted according to the revised return temperature. In both analyses, the fuel savings (i.e. benefit) resulting from the use of the waste heat recovery system were unchanged. With either the original or revised assumptions for the waste heat system, sufficient energy recovery was possible to supply the entire space heat load for the buildings considered. For both cases, the waste heat benefit was 127,000 gallons of diesel fuel saved per year. The waste heat recovery system capital cost ($1,025,000) was unchanged from the value in the Interim Feasibility Assessment for the Cordova Mean-Growth and Level 2 Cordova load forecasts except that replacement of the system was calculated at 20 years instead of 10 years. However, for the Cordova Low-Growth Load, additional capital cost will be incurred because of the need to capture diesel waste heat from the exhaust gas as well as the jacket water cooling to meet the full space heating requirements of the community buildings. The total waste heat recovery system capital cost for this case was $1,450,000. In all cases, the waste heat distribution system operating and maintenance costs were assumed to be $77,000 per year. 3=3 STONE & WEBSTER A ugzLSE3M @ 3NO1S 41809 14N4 143S310 939 1-G°G anbly COST OF DIESEL FUEL ( ¢/GALLON ) s 8 PRESENT DAY [<] [7 | |= | > | = a [= | [> | o | 1O | [2 | Lo | Le | [| [=] [> | [= | le | |> | || LO | [= | [o | le | [7] [S| > | [=| le | Le | [> | [| [O | [2 [o | [= | > | = =| Le | > | | [Oo | 2 | cl = © Ss © = © oo o A1082015 6.0 COAL GENERATION Several different coal-fired power plant options were considered in the Interim Feasibility Assessment. These options remain unchanged except for the cost of diesel fuel used for diesel generators. These diesel generators would supply power to Cordova until the coal plants came on-line in 1986 and then supply backup power during coal plant outages. As described previously, the 1982 cost of diesel fuel was reduced from $1.11 to $1.0695 per gallon. For this addendum, a coal-fired plant design was formulated to supply the Cordova Low-Growth Load projection. This plant consisted of two 4.2 MW stoker-fired units using 11,000 BTU/1b coal. The capital cost for this plant was estimated to be $45,202,000 (1982 dollars), and was assumed to be on-line in 1986. The plant features, operation and maintenance cost, etc., are consistent with the descriptions in Section 6 of the Interim Feasibility Assessment. Process heat can be recovered from a coal-fired power plant and used for applications such as building space heating. However, in both the Interim Feasibility Assessment and this addendum, waste heat recovery was not economic for the coal generation options. Waste heat in coal-fired power plants come from condenser cooling water, equipment bearing cooling water, and stack flue gasses. The temperatures of these heat sources do not generally exceed 105°F, 120°F and 220°F, respectively. It is preferable to maintain flue gas temperatures above acid dewpoints to minimize corrosion and to maximize plume rise to reduce ground level emission concentrations. Consequently, flue gas heat is not generally used for waste heat. The cooling water temperatures are too low to be used effectively in a waste heat exchange system. Diesel plant water jacket temperatures are much higher and can be effectively used. STONE & WEBSTER A Process steam can be extracted from the cycle and used to heat buildings heating water in a cogeneration cycle. However, because the coal-fired power plant at Fleming Spit is more than twice the distance to the buildings to be heated than the diesel plant, waste heat is not economical. As discussed in Section 9 of this addendum, the cost of diesel waste heat recovery was slightly lower than the present worth costs for diesel generation alone. For the three different Cordova load projections, the net present worth savings were $1,300,000 or less in each case. The savings were solely attributable to the increased system life assumed by APA. STONE & WEBSTER A 7.0 HYDROELECTRIC GENERATION 7.0.1 General In addition to the hydroelectric sites discussed in the Interim Feasibility Assessment, sites have been studied within the Copper River Basin downstream of Taral. Each hydroelectric site is identified on maps of the study, |||region.)|||/ ri gures|||7/,0-1il\CRev,.|||)1) |||andiIli7/0-2 .IIllSeCcion)|||7/.7,, | included, herein, addresses the Copper River Basin sites. 7.0.2 Hydroelectric Cost Estimates The cost estimates presented in the Interim Feasibility Assessment did not include costs associated with land and damages and reservoir clearing costs. These have now been included and the revised capital costs with the 30% contingency are as follows: REVISED HYDROELECTRIC PLANT COSTS Old Revised Capacity Capital Costs Capital Costs Site (MW) ($1000) ($1000) Silver Lake 9.0 39,186 403275 Silver Lake 15.0 50,209 Sis269 Allison Lake 9:50 65,823 No change Crater Lake 2, LoS 11,412 Sheep River Lakes 30 32,805 32,912 Lake 1488 4.3 33,055 33,163 Note: Capital costs shown do not include costs associated transmission costs. 7.0.3 Hydroelectric Operations and Maintenance Costs In addition, operation and maintenance costs have been revised for the hydroelectric sites and transmission lines for use in the economic evaluations, which include a 20 percent emergency contingency. This contingency includes an amount to accumulate reserve funds to cover the cost of major maintenance, which would occur at 5 to 10 year intervals. The annual operations and maintenance costs are shown on tables 7.0-1 through 7.0-6. STONE & WEBSTER A 7.0.4 Silver Lake Environmental and Geologic Field Investigations Five months of environmental and geologic investigations were conducted at the Silver Lake site during the summer of 1982. These studies have confirmed that there are no environmental or geologic problems that would prevent hydroelectric development at the site. Six photographs have been included at the end of this section that were obtained during the field investations at the site. These photos show Silver Lake, the dam site, the Duck River near the powerhouse site, the lagoon and dock site. The major elements of the 1982 field season are nearly complete and the field camp along the lower Duck River has been closed. Field work throughout the coming winter and spring will be conducted by means of scheduled monthly visits to collect electronically recorded data. The preliminary analysis of the field work indicates: ° There are no terrestrial ecological constraints to the proposed development. ° There are no archaeological or cultural resource constraints to the proposed development. ° The preliminary hydological data tends to confirm the historical 1913 USGS hydrograph as well as the conservative generation stream flows used in the Interim Feasibility Assessment. ° The lower Duck River - lagoon system is a major spawning and rearing area for both pink and chum _ salmon. The proposed hydroelectric development would consist of the powerhouse located on the Duck River at approximately elevation 65 returning the water back to the river channel upstream of the spawning beds. 7-2 STONE & WEBSTER A The proposed facility and its subsequent operation provides an opportunity for enhancement of the fisheries assuming regulated release of water. It appears that impacts related to the project construction and operations can be mitigated at relatively low cost particularly with reference to the lagoon. The socioeconomic impacts identified to date are positive. No rare or endangered species have been identified in the project area. The reconnaissance level underwater investigation at the construction dock site revealed no invertebrate population that would impose any constraints on the proposed development. ‘The resource agencies have not raised any major objections relative to the proposed project. Geologic and geotechnical information was collected to confirm that the project development is favorable. Data included, regional geology; detailed geology at the dam site, the proposed road and penstock routes, and the powerhouse site; geologic hazards; and on-site availability of construction matrerials. No major constraints to development have been identified. The four borings taken at the dam site have confirmed surface observations of highly competent rock. Pressure tests of the bore holes show only negligible losses. No faults are known to cross the dam site and faults in the general area are probably inactive. The rim of the south abutment side channel was investigated with hand probes, one drill hole and seismic refraction. Preliminary 7-3 p STONE & WEBSTER results from these investigations indicate that the top of bedrock is 10 feet or less below the ground surface. ° Avalanche trails, steep slopes and local areas of peat will influence the siting of the road, penstock and powerhouse. Careful attention to location and design should allow construction without extraordinary costs. ° Rock quarry sites have been identifed should crushing of bedrock be necessary. ° Large gravel sites have been located at the Southeast end of Silver Lake. This gravel has low percentages of some particle sizes needed to make concrete. The quantity of the deposit is sufficient to allow retrieval and screening of the size fractions necessary for a proper concrete mix design. ° The proposed dock would be founded on bedrock. The dock site has exposed bedrock at low tide and no unusual geotechnical problems are anticipated. Engineering Memoranda are included in the Appendix from DOWL Engineers, who have conducted the Silver Lake 1982 field investigations. The Volume 2 of the Addendum contains the 1982 field data. The field investigations have confirmed that there are no environmental or geologic concerns that would prevent the hydroelectric development of this project. The field work ongoing through the winter and spring includes: ° Maintaining the two hydrological stations and obtaining hydrologic data. ° Installing and maintaining facility to determine wind and ice loadings on the proposed transmission line conductors, and collecting weather data. STONE & WEBSTER A ° Make appropriate biological observations. ° Environmental and geological field data analysis. 7=5 STONE & WEBSTER A oa GYQHmaWnh iso] PAUH aA Note: TABLE 7.0-1 HYDROELECTRIC PLANT O & M COSTS SILVER LAKE Item Plant operators at $66,000 to provide daily coverage and limited daily maintenance Plant production supervisor; assigned 25% of time at $72,600/yr APA operations staff time at 100 hrs/yr Consulting services contracts for operation and maintenance Department of energy fees CEC administration overhead costs APA administrative overhead costs Minor operation contracts Annual replacement costs Miscellaneous services and supplies Subtotal 20% Emergency contingency TOTAL Use TABLE 7.0-2 Annual Estimated Cost $132,000 18,105 4,000 20,000 2,500 17,400 15,000 20,000 17,500 15,600 $331,350 66 ,270 $397,620 $400,000 HYDROELECTRIC PROJECT TRANSMISSION LINE O & M COSTS (T02) Item Substation periodic inspection and testing Transmission line inspection and maintenance including SCADA Comm. line rental charge Maintenance of SCADA System Annual relay and meter inspection, testing, and calibration Right-of-way clearing, inspection and maintenance Transmission line loss insurance CEC administrative overhead costs APA operations staff time at 200 hours APA administrative overhead costs APA accounting costs Annual replacement costs Miscellaneous supplies and services Subtotal 20% Emergency contingency TOTAL Use Totals rounded up to the nearest $10,000 Annual Estimated Cost $31,600 123,400 7,500 17,600 42,500 10 ,000 12,000 8,400 8,000 2,000 7,093 4,000 $274,093 54,819 $328,912 $330,000 STONE & WEBSTER A TABLE 7.0-3 HYDROELECTRIC PLANT O & M COSTS ALLISON LAKE Annual Item Estimated Cost A. Plant operators at $66,000 to provide daily coverage and limited daily maintenance $132,000 Br Plant production supervisor; assigned 25% of time at $72,600/yr 18,105 CG. APA operations staff time at 100 hrs/yr 4,000 D. Consulting services contracts for operation and maintenance 20,000 E. Department of energy fees 2,500 F. CEC administration overhead costs 17,400 Ge APA administrative overhead costs 15,000 iG Minor operation contracts 20,000 i Annual replacement costs 17,500 ue Miscellaneous services and supplies 15 ,600 Subtotal $331,350 20% Emergency contingency 66,270 TOTAL $397 ,620 Use $400,000 TABLE 7.0-4 HYDROELECTRIC PROJECT TRANSMISSION LINE 0 & M COSTS ; (TO1) Annual Item Estimated Cost A. Substation periodic inspection and testing $31,600 B Transmission line inspection and maintenance including SCADA Comm. line rental charge 123,400 Cc. Maintenance of SCADA System 7,500 Ds Annual relay and meter inspection, testing, and calibration 17,600 E. Right-of-way clearing, inspection and maintenance 42,500 F Transmission line loss insurance 10,000 G. CEC administrative overhead costs 12,000 H. APA operations staff time at 200 hours 8,400 an APA administrative overhead costs 8,000 J APA accounting costs 2,000 K Annual replacement costs 7,093 L Miscellaneous supplies and services 4,000 Subtotal $274,093 20% Emergency contingency 54,819 TOTAL $328 ,912 Use $330,000 Note: Totals rounded up to the nearest $10,000 STONE & WEBSTER A oa GQHma|WH ca iso] BPAGH RAM Note: TABLE 7.0-5 HYDROELECTRIC PLANT 0 & M COSTS CRATER LAKE, SHEEP RIVER LAKE, LAKE 1488 Annual Item Estimated Cost Plant operators at $66,000 to provide daily coverage and limited daily maintenance $132,000 Plant production supervisor; assigned 25% of time at $72,600/yr 18,105 APA operations staff time at 100 hrs/yr 4,000 Consulting services contracts for operation and maintenance 20,000 Department of energy fees 2,500 CEC administration overhead costs 17,400 APA administrative overhead costs 15,000 Minor operation contracts 20,000 Annual replacement costs 17,500 Miscellaneous services and supplies 15,600 Subtotal $331,350 20% Emergency contingency 66,270 TOTAL $397,620 Use $400,000 TABLE 7.0-6 HYDROELECTRIC PROJECT TRANSMISSION LINE O & M COSTS ' SMALL HYDRO Annual Item Estimated Cost Substation periodic inspection and testing $31,600 Transmission line inspection and maintenance including SCADA Comm. line rental charge 52,000 Maintenance of SCADA System 7,500 Annual relay and meter inspection, testing, and calibration 17,600 Right-of-way clearing, inspection and maintenance 42,500 Transmission line loss insurance 10,000 CEC administrative overhead costs 12,000 APA operations staff time at 200 hours 8,400 APA administrative overhead costs 8,000 APA accounting costs j 2,000 Annual replacement costs 7,093 Miscellaneous supplies and services 4,000 Subtotal $202,693 20% Emergency contingency 40 ,539 TOTAL $243,232 Use $250,000 Totals rounded up to the nearest $10,000 STONE & WEBSTER A PHOTO 1 SILVER LAKE LOOKING UPSTREAM FROM DAM SITE PHOTO 2 SILVER LAKE LOOKING DOWNSTREAM AT THE LAKE MOUTH AND GALENA BAY IN THE DISTANCE SILVER LAKE PHOTO 3 SILVER LAKE DAM SITE LOOKING UPSTREAM FROM THE SOUTH BANK OF THE DUCK RIVER PHOTO 4 DUCK RIVER NEAR POWERHOUSE SITE THE LAGOON PHOTO 5 DUCK RIVER DELTA AT THE LAGOON “2 GALENA BAY <—= DOCK SITE . = PHOTO 6 GALENA BAY DOCK SITE THE LAGOON 100¢8908 ‘CORDOVA =! SELDMON duicd a » Teoastat ROUTE)... Gut TH TAP TO SILVER LAKE) -FIDALGO CREEK — sat we ) 2 } ae LOMON G: a rn me (WITH TAP TO SILVER LAI if LET Le gs # he tort aie “LAKES 1181» 18? AZO PRINCE WILLIAM SOUND de a ,4 Chest, F Teed! Paleo Tow? RN CORDOVA — BERING “(COAL FIELDS) a we 4 a wot Lv & it ' : * SE sai Ae. § ee NOTE: SEE Figure 7. o- 2 ‘FOR ADDITIONAL HYDROELECTRIC SITES. Figure 7.0-1 HYDROELECTRIC SITES (REV 1) STONE & WEBSTER A e00zsolg TAZLIN ed t &> Pes e ( Tonsina re a Figure 7.0-2 HYDROELECTRIC SITES STONE & WEBSTER A 7.7 COPPER RIVER BASIN SITES 7.7.1 General The Copper River has several large capacity (100 MW or_ greater) hydroelectric sites. These sites would offer potential power far in excess of Cordova local or Valdez-Glennallen-Cordova regional requirements. The development of these sites at the present would be too complex and expensive to supply the relatively small load of the Cordova-Valdez-Glennallen region. On this basis, main river development was not considered. Potential hydroelectric sites were identified within the Copper River Drainage Basin downstream of the Taral based upon a review of the topographic maps of the area, The Retherford Reconnaissance Study of Energy Requirements and Alternatives for Cordova, Corps of Engineers’ Interim Feasibility Report and Final Environmental Impact Statement: Electrical Power for Valdez and the Copper River Basin, and the Grumman Ecosystems' Report of Navigability of Streams Tributary to the Copper River and Prince William Sound. The Wrangell-St. Elias National Park and Preserve is located east of the Copper River. Bounded on the south near the Wernicke River and Glacier, the Park lands within the study area extend northward to the Chitina River and are generally designated as wilderness land. Five hydroelectric sites were identified and assessed including Little Bremner River, Falls Creek, Tebay Lakes, Tebay River and Summit Lake. There are a number of hydroelectric sites outside of the Wrangell-St. Elias National Park and Preserve. These sites include Lake 1282, Lake 1120, Van Cleve Lake, Unnamed Creek near Allen Glacier, Tasnuna River, Tiekel River, Cleve Creek and Tonsina River. Cost estimates were prepared for Van Cleve Lake and Tiekel River. All other sites had technical, geographic, or economic flaws which made preparation of cost estimates unnecessary. 7-6 STONE & WEBSTER A An estimate for each site was prepared to determine the total quantity of streamflow available and the annual variance of flow for each watershed considered for hydroelectric development. Observed and recorded streamflow were available from the following gaging stations: Station Location 15201000 Dry Creek near Glennallen 15201100 Little Nelchina River Tributary near Eureka Lodge 15201900 Moose Creek Tributary at Glennallen 15202000 Tazlina River near Glennallen 15206000 Klutina River at Copper Creek 15208000 Tonsina River at Tonsina 15208100 Squirrel Creek at Tonsina 15208200 Rock Creek near Tonsina 15216000 Power Creek 15217000 Strelna Creek near Chitna 15211900 O'Brien Creek near Chitna 15212000 Copper River near Chitna 15226000 Solomon Gulch Other temporary gaging stations have also been established in the area, but these have limited or discrete records. The portion of the Copper River basin near the Gulf of Alaska was evaluated based on the U.S. Forest Service R-10 Water Resources Atlas for streamflow estimates in the Chugach National Forest. For the portion of the Copper River Basin upstream of the Chugach Mountains, the Grumman Ecosystem Mean Annual Precipitation Isohyet Map was used to develop average annual streamflow estimates. 7.7.2 Lake 1282 Lake 1282 is located above Sheep Creek southeast of the Copper River. The lake was dammed by the McPherson Glacier, but due to a recent glacial breakout, the lake no longer exists. The site offers nearly 1,000 feet of head and a drainage basin of nearly 13 square miles. Expected rainfall within the drainage basin is estimated to be 145 inches per year corresponding to a mean annual flow of approximately 120 cfs. iT, STONE & WEBSTER A To develop this site would require two major dams, one located downstream of the McPherson Glacier, and the other in a saddle directly north draining into Sheep Creek. Based upon a review of aerial photographs, a dam in the north saddle is probably feasible although there is an abundance of recent glacial deposits. However, no geologically sound site could be located for a dam downstream of the McPherson Glacier. The combination of poor abutment material, the dynamic nature of the glacier and potential for the glacier to reestablish an ice dam and later breakout, makes this site unsuitable for development. 7.7.3 Lake 1120 Lake 1120 is located above the Martin River west of Martin Lake in the Ragged Mountains. The site offers approximately 1,000 feet of head with a 0.8 square mile drainage basin. Expected precipitation within the drainage basin is estimated annually to be 160 inches which corresponds to a 9 cfs mean annual flow. The site could develop a 1.24 MW plant capacity based upon a 50 percent plant factor. The average annual generation is estimated to be 5,500 MWh. Site development would consist of a small 70 high ft dam providing a maximum water surface elevation at 1190. A 4,500 feet long penstock would connect the dam to a powerhouse at elevation 83. Access to this site would require a new 12.5 mile road constructed from the existing Copper River Highway across the Copper River delta mud flats. The road would require approximately 25 bridges. A 49 mile transmission line would be constructed adjacent to the Copper River Highway and new road. This site would be viable with the development at Katalla of the Bering River coal fields. Further consideration of this site is not warranted at this time due to the site's small capacity in relationship to the project and access road complexity, and potential impacts associated with the access road. In addition, the project costs associated with the new road and transmission line will be large relative to the site's annual generation. 7-8 STONE & WEBSTER aR 7.7.4 Van Cleve Lake Van Cleve Lake is located north of the Miles Glacier and northeast of Miles Lake on the Copper River. The lake is dammed by the Miles Glacier on the southwest. The drainage basin is approximately 80 square miles and has an expected annual average rainfall of approximately 100 inches which corresponds to an average flow of 530 cfs. Assuming that the existing lake water level is at the top of bedrock below the Miles Glacier, the site could develop 40 MW capacity based on a 50 percent plant factor and annual average energy of approximately 170,000 MWh. The proposed development would include an 11 feet diameter concrete lined tunnel from Baird Canyon through the mountain adjacent to LaGorce Glacier at approximately elevation 575 and a lake tap approximately 200 feet below the existing water surface, elevation 801. The required tunnel would be approximately 4 miles in length. The powerhouse would be located at approximately elevation 200 on the bank of the Copper River approximately 1.8 miles upstream of the Abercrombie Rapids. A 3,000 feet penstock would connect the powerhouse and tunnel. Access to the powerhouse would be by the Copper River Highway to’an access road approximately 4 miles long with a bridge across the Copper River at the Abercrombie Rapids. Van Cleve Lake is subject to glacial breakouts as documented by Post and Mayo, "Glacier Dammed Lakes and Outburst Floods in Alaska," (U.S.G.S. HA-455). This Lake drained catastrophically in both 1909 and 1912. The 1912 event was caused ' ‘perhaps from the draining of a marginal lake and swept down the Copper River from Miles Glacier. It raised the water level 12 feet at the railway bridge east of Childs Glacier and swept away 1,600 feet of railway trestle 20 miles further south." The depth of Van Cleve Lake is presently unknown. The Lake appears to drain towards the Miles Glacier with the natural rock below the glacier presumably regulating the lake elevation. This would be difficult if not impossible to confirm. 7-9 STONE & WEBSTER A Transmission Lines for the project would include Cordova To Solomon Gulch - Copper River Route (T03). A 4 mile tie would be constructed from the powerhouse to T03. The capital cost associated with the hydroelectric development is $458 million. Table 7.7-1 is a summary cost sheet with the detailed assessment cost estimate presented in the Appendix. Two possible 138 kV transmission alternatives would be possible with a hydroelectric development at Van Cleve Lake The first alternative would be to construct a transmission river crossing over the Copper River upstream of the Abercrombie Rapids and route the transmission line along the railroad grade and Copper River Highway to Cordova; and construct the Cordova to Solomon Gulch - Coastal Route (TO1) described in the Interim Feasibility Assessment. This transmission route is approximately 125 miles long. The second alternative would be to construct a transmission river crossing over the Copper River upstream of the Abercrombie Rapids and connect with the Cordova to Solomon Gulch - Copper River Route (T03) described in the Interim Feasibility Assessment. This transmission route is approximately 135 miles long. The first and second alternatives have the same transmission distance to Cordova, however, the transmission distance to Solomon Gulch by the first alternative is 125 miles and the second alternative, 78 miles. In addition, the combined Cordova-Valdez-Glennallen load would be carried by the first alternative through Cordova. Therefore, the first alternative would have more line loss than the second alternative. Since there is only 10 miles difference between the two alternatives and the second alternative has less line loss than the first alternative, either transmission line would be acceptable for the Van Cleve development. The Cordova to Solomon Gulch - Copper River Route (T03) was chosen for the purpose of economic evaluation. The capital cost for this transmission route is $59 million as presented in Table 8.10-3 of the Interim Feasibility Assessment. The 710) / STONE & WEBSTER A capital cost of the Copper River crossing upstream of Abercrombie Rapids and substations to T03 route is included in hydroelectric capital cost. It is proposed that operations and maintenance personnel live at the site and man the plant 24 hours a day due to its distance from Cordova and Valdez. The station would be computer controlled. Dispatching would be performed by the operations personnel. We have prepared a budget of 0 & M costs for Hydroelectric Plant and Transmission costs for use in the economic evaluations which includes a 20 percent emergency contingency. This contingency includes an amount to accumulate reserve funds to cover the cost of major maintenance which occurs at 5 to 10 year intervals. The O & M budget is presented in more detail in Tables 7.7-2 and 7.7-3. 7.7.5 Unnamed Creek Near Allen Glacier The unnamed creek is located parallel to and north of the Allen Glacier on the west bank of the Copper River. The creek has a steep gradient within a relatively narrow canyon. The drainage basin is approximately 2.5 square miles and has an annual expected average rainfall of 80 inches, corresponding to an average annual streamflow of 13 cfs. The proposed dam would be 120 feet high with the maximum water surface at elevation 1620. The powerhouse would be located at elevation 400 and a 1.5 feet diameter penstock approximately 1.75 miles long would connect the two. Access to the site would be from the Copper River Highway and the existing railroad grade upstream of the Allen Glacier. A 2.5 mile road would be constructed from the railroad grade to the powerhouse site. The project would develop average annual energy of 3,300 MWh with a 750 kW capacity and 50 percent plant factor. Due to its long transmission line to Cordova, development of this site without development of a larger capacity nearby site such as Van Cleve Lake would not be economically realistic and further consideration at this time is unwarranted. 7-11 5 STONE & WEBSTER 7.7.6 Tasnuna River The Tasnuna River is located west of the Copper River Basin and originates near Marshall Pass. The drainage basin contains the Tasnuna Glacier, Marshall Glacier, Woodworth Glacier, Schwan Glacier, and various smaller unnamed glaciers. The basin is generally wide and has a gentle gradient downstream of the Tasnuna Glacier falling 600 feet in approximately 18 miles. The proposed dam site would be near river mile 20 and has a 55 square mile drainage area. The average annual precipitation is approximately 60 inches corresponding to an average annual streamflow of 200 cfs. The proposed development would include a dam approximately 120 feet high providing a maximum reservoir water surface elevation 700 with a 4 mile long penstock. The powerhouse would be located at elevation 400 on the north bank of the river. The proposed installed capacity would be 2 MW based upon a 50 percent plant factor. Access to the project would be by the Copper River Highway and existing railroad grade to the mouth of the Tasnuna. A new bridge across the Tasnuna and 20 miles of new road would be required on the north bank. Due to the site's long penstock and access route, further consideration is not warranted at this time. 7.7.7 Tiekel River The upper portion of the Tiekel River is located adjacent to the Richardson Highway. The river separates from the highway and flows eastward to the Copper River. The Tiekel River has a 452 square mile drainage basin. Three sites were considered at River Mile 4.8, 11.3 and 13.5, respectively. The River Mile 4.8 site has a drainage basin of approximately 425 square miles and expected average annual precipitation of 55 inches which corresponds to average annual streamflow of 1,500 cfs. This site has very limited storage and would require a 300 feet high dam to develop 2 riz STONE & WEBSTER A megawatts of capacity based upon a 50% plant factor. The powerhouse would be located at the dam. Further consideration of this site is unwarranted due to the large dam required for a relatively small installed capacity. The River Mile 11.3 site has a drainage basin of approximately 365 square miles and average annual precipitation of 55 inches which corresponds to an average annual stream flow of 1,275 cfs. With a 200 feet high dam with a maximum water surface at elevation 1100 and 6.5 miles of 6 feet diameter penstock, 10 megawatts of capacity can be developed based upon a 50 percent plant factor. The firm annual energy available is approximately 43,800 MWh. The proposed River Mile 11.3 site development would include a 200 ft high concrete faced rock filled dam with the powerhouse located at elevation 500. A concrete low level outlet and diversion works as well as a concrete lined spillway would be incorporated in the dam. The diversion can accommodate 35,000 cfs and the unregulated spillway 165,000 cfs. The main project structures have been assumed to be founded on rock. However, this is not confirmed. The access road to the dam and powerhouse would be from the Richardson highway via one bridge over the Tiekel River. The River Mile 13.5 site has a drainage basin of approximately 345 square miles and average annual precipitation of 55 inches which corresponds to an average annual streamflow of 1,200 cfs. With a 200 feet high dam and 2.9 miles of 9 feet diameter penstock approximately 15 megawatts of capacity can be developed based upon a 50 percent plant factor. The firm annual energy available is approximately 65,700 MWh. The proposed River Mile 13.5 site development would include a 200 ft high concrete faced rock filled dam with the powerhouse located at elevation 800. A concrete low level outlet and diversion works as well as a concrete lined spillway would be incorporated in the dam. The diversion can accommodate 32,000 cfs and the unregulated spillway 150,000 cfs. The main project structures have been assumed to be founded on rock. However, this is not confirmed. The reservoir as dipicted will inundate about 7 miles of the Richardson highway, Trans-Alaska Pipeline, and Solomon Gulch to Glennallen transmission line, requiring their relocation to higher ground. 7-12 STONE & WEBSTER A The access road to the dam and powerhouse would be from the relocated highway via two bridges over the Tiekel River. Transmission lines to either site would include Cordova to Solomon Gulch - Coastal Route (TO1). A transmission tie and switchyard would be constructed to connect the project with the existing Solomon Gulch to Glennallen transmission line. Based upon the above description of the proposed project development including required facilities relocation and new transmission tie, the capital cost estimate is $692 million for the River Mile 11.3 site and $ 648 million for the River Mile 13.5. Table 7.7-4 is a breakdown of this estimate. The Cordova to Solomon Gulch - Coastal Route (T0O1) capital cost estimate is $28.6 million. This transmission estimate is included in the Interim Feasibility Assessment in Table 8.10-1. It is proposed to provide living quarters at the site but only man the plant on a daily basis, as the site has relatively good access via the Richardson Highway to Valdez, Copper Center, or Glennallen. The station would be computer controlled with operations automated to the extent possible. Dispatching would be performed by the operations personnel. We have prepared a budget of O&M costs for Hydroelectric Plant and Transmission costs for use in the economic evaluations which includes a 20 percent emergency contingency. This contingency includes an amount to accumulate reserve build up funds to cover the cost of major maintenance which occurs at 5 to 10 year intervals. The O&M budget is presented in more detail in Tables 7.7-5 and 7.7-6. 7.7.8 Cleave Creek Cleave Creek is located between the Tasnuna and Tiekel Rivers. The creek originates at the Cleave Creek Glacier and has a drainage basin of approximately 45 square miles. The proposed dam site would have a drainage basin of approximately 35 square miles with an average annual expected precipitation of 60 inches, 7-14 STONE & WEBSTER A which corresponds to an average annual streamflow of 130 cfs. The powerhouse would be located at elevation 400 approximately 1.6 miles downstream of the dam. Based upon a 200 ft high dam with maximum water surface elevation 800, the installed capacity would be 1.3 MW based upon a 50 percent plant factor. Access to the project site would be from the existing railroad grade to the Copper River Highway. A transmission line approximately 90 miles in length would be constructed adjacent to the railroad grade and highway from the project to Cordova. In view of this site's small capacity and high cost of the long access road and transmission lines, further consideration of this site is unwarranted. 7.7.9 Little Bremner River The Little Bremner River is located on the east side of the Copper River within the Wrangell-Saint Elias National Park and Preserve. The Little Bremner is a tributary of the Bremner River located upstream of Miles Lake and Baird Canyon. The proposed development is located on the East Fork of the Little Bremner. The drainage basin upstream of the dam site is 60 square miles and has an expected annual precipitation of 40 inches. The estimated average annual streamflow is estimated to be 145 cfs. Based upon a 200 ft high dam with maximum water surface elevation 1400 and a 2.3 miles of 2.5 ft diameter penstock, 2.5 megawatts of capacity can be developed based upon a 50 percent plant factor. The powerhouse would be located at elevation 400 on the Little Bremner downstream of the East Fork. A 20 mile access road including a bridge accross the Copper River would be required from the railroad grade on the west bank of the Copper River. Due to the site's small capacity relative to the site's access difficulties, and the site's location within a wilderness area, further consideration of this site is unwarranted. 7-15 STONE & WEBSTER A 7.7.10 Tebay Lakes The Tebay Lakes are located northeast of the Bremner River and east of the Copper River within the Wrangell-Saint Elias National Park and Preserve. The Tebay River originates at the Tebay Lakes and discharges into the Chitina River upstream of its junction with the Copper River at Chitina. For the main Tebay Lakes, the lower is at elevation 1799, the middle is at elevation 1816, and the upper is at elevation 1842. There are a number of small lakes which surround the three main lakes. The proposed development would consist of a concrete overflow section approximately 200 ft long and a nonoverflow rock fill dam approximately 1400 ft in length with a maximum height of 50 ft. The drainage basin is 45 square miles with an expected annual precipitation of 30 inches which corresponds to an available streamflow of 80 cfs. The 50 ft high dam would raise the water level of the three main lakes to approximately elevation 1850. A 30 ft deep channel would connect the Upper and Middle Lakes. A lake tap would divert water from the Upper Tebay Lake through a tunnel and powerhouse discharging into the Little Bremner River. Three 5 ft diameter tunnel lengths of 3, 4 and 5.2 miles were considered; the corresponding capacities are 10, 12, and 14 megawatts based upon a 50 percent plant factor. A 22 mile access road including a bridge accross the Copper River would be required to the powerhouse from the railroad grade on the west bank of the Copper River. Access to the dam site would require a 15 mile construction road and bridge across the Chitina River. The Tebay Lakes are surrounded by the wilderness area, although the reservoir and dam would not be within this area; however, the roads, transmission lines, powerhouse and support facilities are within the wilderness area. The complexity of developing this site, its limited capacity, and location within the wilderness area, make further consideration of this site unwarranted. 7-16 STONE & WEBSTER A 7.7.11 Falls Creek Falls Creek is located on the west end of the Upper Tebay Lake within the Wrangell-Saint Elias National Park and Preserve. The creek discharges into the Little Bremner River. The drainage basin upstream of the proposed dam site is approximately 40 square miles and has an expected average annual precipitation of 30 inches corresponding to a streamflow of 75 cfs. Based upon a 100 ft high dam with a maximum water surface elevation 2000, and a 2.3 mile 2.5 ft diameter penstock, 4.5 megawatts of capacity can be developed based upon a 50 percent plant factor. The powerhouse would be located at elevation 1200. A 22 mile access road including a bridge accross the Copper River would be required to the powerhouse from the railroad grade on the west bank of the Copper River. The complexity of developing this site, its limited capacity, and location within the wilderness area, make further consideration of this site unwarranted. 7.7.12 Tebay Lakes and Falls Creek Diversion The Tebay Lakes and Falls Creek location descriptions are discussed in sections 7.7.10 and 7.7.11 and will not be repeated. The Falls Creek flow would be diverted into the Upper Tebay Lake by a small 30 ft high diversion dam on Falls Creek and a 4000 ft long 15 ft deep canal. The combined drainage basin is 85 square miles and 155 cfs average streamflow. A 50 ft high dam would raise the water level of the three main Tebay Lakes to approximately elevation 1850. A 40 ft deep channel would connect the Upper and Middle lakes and a 10 ft deep channel would connect the Middle and Lower lakes. A lake tap would divert water from the Upper Tebay Lake through a tunnel and powerhouse, discharging into the Little Bremner River. Three 6 ft diameter tunnel lengths of 3, 4 and 5.2 miles were considered; the 7-17 STONE & WEBSTER A corresponding plant capacities are 20, 24 and 28 megawatts based upon a 50 percent plant factor, and average annual energy generation of 88,000, 105,000 and 123,000 MWh, respectively. A 22 mile access road including a bridge across the Copper River would be required to the powerhouse from the railroad grade on the west bank of the Copper River. Access to the dam sites would require a 23 mile construction road and bridge across the Chitina River. The Falls Creek diversion dam and canal, access roads, transmission lines, powerhouse and support facilities are within the wilderness area. The complexity of accessing and developing this site, the inability of the region to absorb the available generated energy from the development, and its location within the wilderness area, make further consideration of this site unwarranted. 7.7.13 Tebay River The Tebay River originates at the Lower Tebay Lake. The proposed dam site would be located downstream of the junction of the Hanagita River and Bridge Creek with the Tebay River. The project would be entirely in the Wrangell-Saint Elias National Park and Preserve wilderness area. The drainage area upstream of the dam site is 295 square miles and the expected average annual precipitation is 30 inches, which corresponds to an average annual streamflow of 530 cfs. Three levels of development were considered for this site based upon a 200 ft high concrete faced rock fill dam with a maximum watrer surface elevation of 1700. The dam and the powerhouse would be connected by a 7.5 ft diameter concrete lined tunnel. The three alternatives are the powerhouse at the dam, the powerhouse 2 miles downstream, and the powerhouse 6.5 miles downstream; based upon a 50 percent plant factor, the respective capacities are 4, 13.5 and 32 megawatts. The corresponding firm annual generations and 17,500, 58,700 and 141,000MWh. The powerhouse location 6.5 miles downstream (32 MW) was considered further. 7-18 STONE & WEBSTER A The first section of access road would be an improvement of 15 miles of existing road and railroad grade on the north bank of the Chitina River upstream from Chitina. Approximately 9 miles of new road and a bridge accross the Chitina River would be required to the powerhouse. A 4.5 mile construction haul road would be constructed to the dam site. A 35 mile transmission line would be constructed to connect the Tebay River powerhouse to the existing Solomon Gulch-Glennallen transmission at Pippin Lake near Tonsina. The transmission line would follow the access road to Chitina and the Edgerton Highway to Pippin Lake. The complexity of accessing and developing this site and its location within the wilderness area, make ‘further consideration of this site unwarranted. 7.7.14 Summit Lake Summit Lake is located northwest of the Tebay River. Bridge Creek originates at the Lake and joins with Tebay River. The lake is located at elevation 2818. The project would be entirely in the Wrangell-Saint Elias National Park and Preserve wilderness area. The drainage area upstream of the dam site at the mouth of the lake is 15 square miles and the expected average annual precipitation is 20 inches; the corresponding streamflow is 17 cfs. Based upon a 30 ft high dam with a maximum water surface elevation of 2840, 2.5 miles of 2.5 ft penstock, and a powerhouse located to discharge into the Tebay River reservoir (section 7.7.13), the capacity would be 2.3 Megawatts, and average annual generation of 10,000MWh. The access road and transmission would be as discussed for the Tebay River site. 7-19 STONE & WEBSTER A Due to the site's small capacity and access difficulties, and the site's location within a wilderness area, further consideration of this site is unwarranted. 7.7.15 Tebay River and Summit Lake Combined With Tebay River site and Summit Lake combined the total installed capacity would be 34.3 Megawatts and firm annual generation of 151,000 MWh. The complexity of accessing and developing the combined site, the inability of the region to absorb the available generated energy, and the location within a wilderness area, make further consideration of this site unwarranted. 7-20 STONE & WEBSTER A 10. 11. 12. 13. 14. 15. TABLE 7.7-1 COST ESTIMATE VAN CLEVE LAKE Mobilization and Site Preparation Work Land and Damages Access Road and Bridge Intake Works, Tunnel, and Penstock Power Plant Transmission Tap to TO1 incl. Switchyard Buildings, Grounds and Utilities Total Direct Costs Engineering and Design (10%) Construction Management (10%) Subtotal Contingency Total Project Costs Interest During Construction Total Cost Rounded to Costs ($1,000) Installed Capacity 40 MW 3,000 3,720 42,581 214,969 14,000 2,280 1,000 281,550 28,155 28,155 337,860 101,358 439,219 18,680 457,899 $458 Million STONE & WEBSTER A TABLE 7.7-2 HYDROELECTRIC PLANT O & M COSTS VAN CLEVE LAKE Annual Item Estimated Cost A. Plant operators at $66,000 to provide daily coverage and daily maintenance (7 operators/maintenance personnel) $462,000 B. Plant production supervisor assign 100% of time at $72,600/yr 72,600 Cc. APA operations staff time at 200 hrs/yr 8,000 D. Consulting services contracts for operation and maintenance 20,000 E. Department of energy fees 2,500 F. CEC administration overhead costs * 17,400 G. APA administrative overhead costs 15,000 H. Minor operation contracts 40,000 I. Annual replacement costs 35,000 J. Miscellaneous services and supplies 31,200 Subtotal 703,700 20% Emergency contingency 140,740 TOTAL $845 ,440 Use $850,000 TABLE 7.7-3 HYDROELECTRIC PROJECT TRANSMISSION LINE O & M COSTS VAN CLEVE LAKE (TO3 Plus 4 Mile Tap) Annual Item Estimated Cost A. Substation periodic inspection and testing $31,600 B Transmission line inspection and maintenance including SCADA Comm. line rental charge 123,400 c. Maintenance of SCADA System 7,500 D. Annual relay and meter inspection, testing, and calibration 17,600 Eis Right-of-way clearing, inspection and maintenance 42,500 F. Transmission line loss insurance 10,000 G. CEC administrative overhead costs 12,000 H. APA operations staff time at 200 hours 8,400 L. APA administrative overhead costs 8,000 Js APA accounting costs 2,000 K. Annual replacement costs 7,093 L. Miscellaneous supplies and services 4,000 Subtotal $274,093 20% Emergency contingency 54,819 TOTAL $328,912 Use $330,000 Note: Totals rounded up to the nearest $10,000 STONE & WEBSTER A TABLE 7.7-4 COST ESTIMATE TIEKEL RIVER 1. Mobilization and Site Preparation Work 2. Land and Damages 3. Access Road, incl. Bridge(s) 4. Intake Works, Tunnel, and Penstock 5. Main Dam, incl. Diversion 6. Spillway and Plunge Pool 7. Power Plant 8. Transmission Tap to CVEA Line incl. Switchyard 9. Buildings, Grounds and Utilities 10. Total Direct Costs 11. Engineering and Design (10%) 12. Construction Management (10%) 13. Subtotal 14. Contingency 15. Total Project Costs 16. Interest During Construction 17. Total Cost Rounded to R.M. = River Mile Costs ($1,000) Installed Capacity RM 11.3 RM 13.5 (LOMW) (15MW) 3,000 3,000 1,320 45,900*) 23,972 20, 566%) 194,272 100,155 73,638 101,676 115,255 112,930 8,000 11,150 4,520 1,820 1,000 1,000 424,977 398,197 42,498 39,820 42,498 39,820 509,973 477,837 152,992 143,351 662,965 621,188 29,170 27,332 692,135 648,520 $692 Million $648 Million *) includes relocation of Trans-Alaska Pipeline and Valdez-Glennallen Transmission Line %*%*) includes relocation of Richardson Highway STONE & WEBSTER A TABLE 7.7-5 HYDROELECTRIC PLANT O & M COSTS TIEKEL RIVER Annual Item . Estimated Cost A. Plant operators at $66,000 to provide daily coverage and limited daily maintenance $132,000 B. Plant production supervisor assign 25% of time at $72,600/yr 18,105 Cc. APA operations staff time at 100 hrs/yr 4,000 D. Consulting services contracts for operation and maintenance 20,000 E. Department of energy fees 2,500 Fs CEC administration overhead costs 17,400 G. APA administrative overhead costs 15,000 H. Minor operation contracts 20,000 in Annual replacement costs 17,500 J. Miscellaneous services and supplies 15,600 Subtotal $331,350 20% Emergency contingency 66,270 TOTAL $397,620 Use $400,000 TABLE 7.7-6 HYDROELECTRIC PROJECT TRANSMISSION LINE O & M COSTS TIEKEL RIVER (TO1 Plus 6 Miles Tap to CVEA Glennallen Line) Annual Item Estimated Cost A. Substation periodic inspection and testing $31,600 B. Transmission line inspection and maintenance including SCADA Comm. line rental charge 123,400 Cc. Maintenance of SCADA System 7,500 Ds Annual relay and meter inspection, testing, and calibration 17,600 E. Right-of-way clearing, inspection and maintenance 42,500 F. Transmission line loss insurance : 10,000 G. CEC administrative overhead costs 12,000 H. APA operations staff time at 200 hours 8,400 Te APA administrative overhead costs 8,000 J. APA accounting costs 2,000 Re Annual replacement costs 7,093 L. Miscellaneous supplies and services 4,000 Subtotal $274,093 20% Emergency contingency 54,819 TOTAL $328,912 Use $330,000 Note: Totals rounded up to the nearest $10,000 STONE & WEBSTER Ad 8.0 TRANSMISSION SYSTEMS This section remains essentially unchanged. The costs associated with operations and maintenance have been revised for those transmission alternatives which would connect the hydroelectric alternatives with Cordova and/or Valdez. The revised transmission annual operations and maintenance cost are presented in Section 7 of this addendum with each hydroelectric alternative. STONE & WEBSTER dA 9.0 ECONOMIC EVALUATIONS This addendum includes economic evalutaions of the most promising alternatives identified in the Interim Feasibility Assessment plus evaluations of the additional options considered herein. Certain revised costs and economic parameters were used in the economic analyses which differed from those used in the Interim Feasibility Assessment. The differences are described in the following sections with the revised economic results. 9.1 ECONOMIC PARAMETERS AND ASSUMPTIONS The economic parameters and assumptions used to calculate present worth costs were in conformance with the Power Authority guideline, "Economic Analysis for Alaska Power Authority Reconnaissance and Feasibility Studies - Standard Procedure and Sample Cost Calculation - FY82", except for the economic lifetimes of two equipment types. As for the Interim Feasibility Assessment, the economic lifetime of transmission lines was increased from the suggested 20 years to a value of 40 years due to the longer lifetime of steel transmission towers compared to wooden poles. In addition, the economic lifetime for diesel waste heat recovery equipment was increased from 10 to 20 years. The parameters listed in Table 9.1-1 of the Interim Feasibility Assessment were used in the economic analysis for all scenarios. As before, inflation was assumed to be zero and all costs (with the exception of petroleum fuels) were expressed in terms of 1982 dollars. Petroleum fuels were assumed to escalate at a rate of 2.6 percent above inflation. All annual costs for each scenario were assigned as described in Section 9.1 of the Interim Feasibility Assessment. Lastly, in accordance with Power Authority Guidelines, the costs developed in these evaluations represent busbar costs and do not include all items which affect actual consumer cost. For example, cost allowances were not made for electrical distribution within Cordova, administration, taxes, depreciation, debt service on existing equipment, or insurance. If ‘these STONE & WEBSTER a costs were included, the present worth of consumer costs would be higher than the present worth of busbar costs determined in this study. However, the inclusion of these additional consumer costs would not affect the relative comparison of the present worth value of alternatives since these costs remain essentially the same in all cases. 9.2 ECONOMIC ANALYSIS METHODOLOGY The major steps involved in determining present worth costs for each power supply alternative remain unchanged from the description in Section 9.2 of the Interim Feasibility Assessment. The same computer program was used to determine present worth costs as prescribed in the FY-82 Power Authority Guidelines. Computer printouts for each alternative subjected to economic evaluation are included in a supplement to this addemdum. 9.3 ECONOMIC ANALYSIS OF ALTERNATIVES Total present worth costs were developed for each alternative examined certain sensitivity studies were performed. The results of these analyses are provided below. 9.3.1 Economics of Diesel Generation The diesel generation options considered in this study were very similar to those considered previously. The capital costs, O&M costs, and gallons of diesel fuel required were assigned as described in the Interim Feasibility Assessment. The specific values used are shown on the economic evaluation computer listings included in the supplement to this study. Alternative DO1, Eyak Plant Expansion, was the basis for the evaluations of the diesel generation in this addendum. Based on actual CEC cost data, the diesel fuel price used was $1.0695/gallon ($1.052/gallon for the diesel fuel plus $0.0175/gallon for transport to the plant). Parts and miscellaneous expenses, excluding labor, were based on CEC records and cost 4.8 mills/kWh. The plant staff was estimated to consist of eight people (including supervision) at an average salary, including benefits, of $25/hour. The total present worth life-cycle cost for each diesel generation alternative is: 9-2 STONE & WEBSTER A Present Worth of Diesel Generation Options Present Worth CEC Load Projection Millions of $ Cordova Low - Growth Load 78 Cordova Mean - Growth Load 141.9 Cordova Level 2 (High) Growth Load 7 Glee, Variations to the continued use of diesel generation were also evaluated, including the use of diesel waste heat recovery for space heating in Cordova public buildings (see Section 5.7.2 in the Interim Feasibility Assessment). The annual benefit accruing from the waste heat recovery was calculated as the cost of diesel fuel not needed to be burned to provide space heating for these buildings. The resulting present worth life-cycle costs for the diesel generation plus waste heat recovery systems are: Present Worth of Diesel Generation and Waste Heat Recovery Options Present Worth CEC Load Projection Millions of $ Cordova Low - Growth Load L732) c Cordova Mean - Growth Load 140.6 Cordova Level 2 (High) Growth Load 174.9 A small savings in present worth cost results when a waste heat recovery system is used in conjunction with the diesel generation option. Lastly, a special economic sensitivity evaluation was performed for the diesel generation options in regard to diesel fuel escalation. As previously discussed, a diesel fuel escalation rate of 2.6 percent per year was used for the base case diesel generation options. However, these evaluations were repeated with a value of zero diesel escalation per year to illustrate the effect of lower than expected diesel price increases. The present worth life-cycle costs for no diesel fuel escalation are: ae STONE & WEBSTER aR Diesel Generation Options No Diesel Fuel Escalation Present Worth Option Millions of $ No Waste Heat Recovery - Cordova Low - Growth Load 90.5 - Cordova Mean - Growth Load 106.8 - Cordova Level 2 (High) Growth Load 130.2 With Waste Heat Recovery - Cordova Low - Growth Load 91.4 - Cordova Mean - Growth Load 107.0 - Cordova Level 2 (High) Growth Load 130.4 These results show that the economic viability of diesel waste heat recovery depends on the fuel escalation rate. At 2.6 percent per year diesel escalation, the use of a waste heat recovery system results in slightly lower present worth costs compared to diesel generation alone. However, without diesel fuel escalation, the waste heat recovery systems result in slightly higher present worth costs, indicating that the diesel savings are not sufficient to offset the waste heat system capital and O&M costs. 9.3.2 Economics of Coal-Fired Generation As discussed in the Interim Feasibility Assessment, the coal-fired alternatives were assumed to be installed and operating by 1985. Operating and maintenance costs were estimated at 1¢/kWh for the dual unit plants with an availability of 96 percent. A plant staff of 20 earning an average salary of $25/hour (including benefits) was used to develop total operating costs. All coal alternatives include a back-up diesel generation plant with a capital cost of $3.4 million. The coal plants are of similar design, are located at the Fleming Spit site, and include the predicted site preparation costs. The present worth life-cycle costs are: ae STONE & WEBSTER a Coal-Fired Options Present Worth Cordova Load Projection Millions of $ Cordova Low-Growth Load Dual 4.2 MW units 123.0 Cordova Mean-Growth Load Dual 5.0 MW Units 140.8 Cordova Level 2 (High) Growth Load Growth - Dual 6.0 MW Units 166.5 9.3.3 Economics of Hydroelectric Generation In this addendum, those hydroelectric options which were identified in the Interim Feasibility Assessment as potentially viable power supply options for Cordova were reevaluated along with several new sites. This analysis was performed because of changes in the following costs as described earlier in this addendum: o hydroelectric 0&M costs o transmission O&M costs o land acquisition costs o reduction in diesel fuel cost used as back-up from $1.11 to $1.0695/gallon The hydroelectric options which have been evaluated include Silver Lake, small hydroelectric facility combinations, Allison Lake, Van Cleve Lake, and Tiekel River. To determine the present worth costs of the small hydroelectric facilities, the timing in which these sites would be brought on-line must be examined. For the Cordova Mean-Growth Load and Level 2 (High) Growth Load, small hydroelectric Combinations 1 and 2 were previously formulated and described in the Interim Feasibility Assessment (Section 9.3.3). The timing for the small hydroelectric projects in Combinations 1 and 2 has not been changed in this addendum, but the present worth life-cycle costs have been revised based on the changes in the four cost categories. 9-5 STONE & WEBSTER A For the Cordova Low-Growth Load, three new small hydroelectric scenarios have been formulated. These scenarios, designated Combinations 3, 4, and _5, are illustrated in Figures 9.3-1, 9.3-2, and 9.3-3, respectively. The timing of the small hydroelectric project combination are as follows: Small Hydroelectric Scenarios Project On-Line date Combination 3 Lake 1488 1986 Crater Lake 1994 Combination 4 Lake 1488 1986 Combination 5 Sheep River Lakes 1986 Crater Lake 1986 As shown on the three figures, supplemental diesel generation is used when the Cordova load exceeds the hydroelectric output. The present worth life-cycle costs for the hydroelectric projects are: Hydroelectric Options* Cordova Only Present Worth, Millions of $ Level 2 Cordova Load Growth Projection: Low Mean (High) Silver Lake + Transmission 103.3 104.6 115.1 Best Small Hydroelectric Combination + Transmission** 89.3 118.0 138.3 Allison Lake + Transmission 119.5 1327.0 167.8 * Due to its large capacity, the Van Cleve Lake Project was not evaluated for the Cordova-only case. ** The best small hydroelectric combination for the Cordova low growth load is Combination 4, and for the Cordova Mean and Level 2 (High) growth load is Combination 2. The other Combinations provide higher present worth costs for the applicable load forecast. o STONE & WEBSTER A Lastly, an additional hydroelectric variation was studied which considered the sole development of Silver Lake, Allison Lake, Van Cleve Lake, and Tiekel River. It was assumed that any surplus capacity from the project above the Cordova (CEC) load could be sold to Valdez-Glennallen (CVEA) to displace diesel-fired electrical generation. The three Cordova load projections and the Valdez-Glennallen Low-Growth Load were included in this analysis. The CVEA load above the capacity of the Solomon Gulch Hydroelectric Plant is currently supplied by diesel generation and is the load that can potentially be supplied by excess hydroelectric capacity. Solomon Gulch has a firm capacity of 41,000 MWh per year. The CEC load, CVEA load, and quantity of energy assumed to be sold to CVEA are shown in Tables 9.3-1, 9.3-2, and 9.3-3 for the Cordova Low-Growth Load, Mean-Growth Load, and Level 2 (High) Growth Load. The benefit from the sale of this energy, in terms of gallons of diesel saved, was calculated using a CVEA diesel generator fuel rate of 0.0769 gallons/kWh produced. In order to calculate the annual savings resulting from this benefit, the 1982 CVEA diesel price of $1.03/gal was used. This cost was escalated at 2.6 percent per year after 1982 through the year 2002. The results of the present worth life-cycle analyses for the hydroelectric sites are shown below: Sale of Excess Hydroelectric Energy to CVEA* Present Worth Scenario Millions of $ Cordova Low-Growth Load - Silver Lake** (r/c) - Allison Lake 105.6 - Van Cleve Lake 443.3 - Tiekel River RM 11.3 635.9 RM 13.5 STi Cordova Mean-Growth Load - Silver Lake** 85.6 - Allison Lake Qi ioe) - Van Cleve Lake 444.5 - Tiekel River RM 11.3 654.8 RM 13.5 575.2 9-7 STONE & WEBSTER aR Sale of Excess Hydroelectric Energy to CVEA* Present Worth Scenario Millions of $ Cordova Level 2 (High) Growth Load - Silver Lake** 113.1 - Allison Lake 165.8 - Van Cleve Lake 445.2 - Tiekel River RM 11.3 683.9 RM 13.5 596.7 * Valdez-Glennallen Low-Growth Load ** 15 MW capacity Significant regional benefits result when excess hydroelectric energy is supplied to CVEA. 9.3.4 Economics of Wood-Fired Generation The evaluation of a wood-fired power plant was not included in the Interim Feasibility Assessment. However, for this addendum, a wood-fired power plant has been evaluated for each of the three Cordova (CEC) load projections. The design and economic analysis of these plants were based on the following assumptions: o The capital cost of the wood-fired units would be the same as for the equivalent coal units except that no flue-gas scrubber system would be required; o due to differences in energy content of wood and coal, the required fuel rate for the wood-fired plant would be 20 percent greater than for a coal-fired plant using Healy coal; o the operation and maintenance costs for the wood-fired plant, after being adjusted for the wood fuel rate and ash disposal, would be identical to the coal plant costs. The evaluation was performed for several different wood fuel prices due to the uncertainty regarding the wood cost in Cordova for a large-scale timber 9-8 STONE & WEBSTER a harvesting operation. This price would represent the delivered, pelletized wood price at the power plant. The present worth life-cycle costs for the wood-fired options are as follows: Wood-Fired Power Plant Present Worth, Millions of $ Wood Cost $/ton 0 16 32 48 64 $/cord 0 20 40 60 80 Cordova Load Projection Cordova Low-Growth Load 98.4 108.4 118.5 128.5 138.5 Cordova Mean-Growth Load 109.6 122;.2 134.9 147.6 160.2 Level 2 (High) Growth Load 121.2 137.6 153.9 170.3 186.6 The wood-fired plant was assumed to be located at Fleming Spit and, as for the coal-fired plants, includes expected site preparation costs in the capital cost estimate. The computer listings from the economic analyses for the wood-fired options are included in the supplement to this addendum. 9-9 STONE & WEBSTER A Year 1982 1983 1984 1985- 1986 1987 1988 1989 1990 1991 1992 1993 1994 995 1996 1997 1998 1999 2000 2001 2002 TABLE 9.3-1 EXCESS HYDROELECTRIC POWER SOLD TO CVEA* CORDOVA LOW-GROWTH LOAD VALDEZ-GLENNALLEN LOW-GROWTH LOAD CVEA Load Minus CEC_Load, CVEA, Load, Solomon Gulch 103 MWh 103 MWh Output, 103MWh NS 47.2 6.2 17.5 48.1 el 18.0 49.1 Ber! 18.5 50.1 9.1 19.1 51.1 10.1 19.7 52.1 ave 20.2 53.2 Ne 21.0 54.2 age) 21.8 55.3 SS 22.4 56.4 15.4 23.0 57.5 16.5 23.8 58.7 Wa 24.5 59.9 18.9 24.8 ener 20.1 25.5 62.3 213) 26ul 63.5 22.5 26.7 64.8 23.8 272 66.1 25.1 27.8 67.4 26.4 28.5 68.8 27.8 29.2 Onl 29.1 CVEA Load Supplied by Excess Hydroelectric Power, 103 MWh Silver Allison Van Teikel River Lake Lake Cleve RM 11.3 RM_ 13.5 10.1 10.1 10.1 10.1 10.1 eo! elt 11.1 elven 11.1 12.2 12.0 12.2 12.2 12.2 13.2 11.2 13.2 13.2 13.2 14.3 10.4 14.3 14.3 14.3 15.4 9.8 15.4 15.4 15.4 16.5 9.2 16.5 16.5 16.5 Aone 8.4 17.7 Aiat Teil 18.9 7.7 18.9 18.9 18.9 20.1 7.4 20.1 19.0 20.1 21.2 Gen} anes 1633) 21.3 20.6 6.1 22.5 Tiel) 22.5 20.0 5.5 23.8 [je 23.8 19.5 5.0 25.1 16.6 25.1 18.9 44 26.4 16.0 26.4 18.2 3.7 27.8 15.3 27.8 1725 3.0 29.1 14.6 29.1 * Solomon Gulch output = 41,000 MWh/yr; Silver Lake output = 46,700 MWh/yr; Allison Lake output = 32,200 MWh/yr; Van Cleve output = 170,000 MWh/yr; Tiekel (RM 11.3) output = 43,800 MWh/yr; Tiekel (RM 13.5) output = 65,700 MWh/yr *#* In economic analyses, these values were reduced by 2% due to hydroelectric outage factor. STONE & WEBSTER A TABLE 9.3-2 EXCESS HYDROELECTRIC POWER SOLD TO CVEA* CORDOVA MEAN-GROWTH LOAD VALDEZ-GLENNALLEN LOW-GROWTH LOAD CVEA Load Minus CVEA Load Supplied by Excess Hydroelectric Power, 103 MWh CEC Load, CVEA Load, Solomon Gulch Silver Allison Van Tiekel River Year 103 MWh 103 MWh Output, 103MWh Lake Lake Cleve RM 11.3 RM 13.5 1982 18.2 47.2 6.2 - - = = 1983 20.5 48.1 Tell = - - = 1984 2102 49.1 8.1 = = = = 1985 22.0 50.1 9.1 s x a 1986 22.1 51.1 10.1 9.0 10.1 10.1 10.1 10.1 1987 22.3 52.1 Ted 12.0 9.9 Ted aaa 11.1 1988 23.3 53.2 1242 15.0 8.9 12.2 New 12.2 1989 23.8 54.2 13.2 18.0 8.4 ase 1352 13.2 1990 24.7 55.3 14.3 21.0 7.5 14.3 14.3 14.3 1991 26.0 56.4 15.4 24.4 6.2 15.4 15.4 15.4 1992 QT 57.5 16.5 27.8 4.5 16.5 16.1 16.5 1993 28.9 58.7 TT 27.5 363 Via 14.9 Mie? 1994 29.6 59.9 18.9 Ajo 2.6 18.9 14.2 18.9 1995 30.1 611 20.1 16.6 2.1 20.1 Sey 20.1 1996 31.0 62.3 2103 15.7 Tee 21.3 12.8 21.3 1997 31.8 63.5 22.5 14.9 0.4 22.5 12.0 22.5 1998 33.0 64.8 23.8 ATS 7 - 23.8 10.8 23.8 1999 34.5 66.1 25.1 Ne) - 25.1 9.3 25.1 2000 35.8 67.4 26.4 10.9 - 26.4 8.0 26.4 2001 36.8 68.8 27.8 9.9 = 27.8 T20 27.8 2002 38.3 70.1 29.1 8.4 - 29.1 5.5 27.4 * Solomon Gulch output = 41,000 MWh/yr; Silver Lake output = 46,700 MWh/yr; Allison Lake output = 32,200 MWh/yr; Van Cleve output = 170,000 MWh/yr; Tiekel (RM 11.3) output = 43,800 MWh/yr; Tiekel (RM 13.5) output = 65,700 MWh/yr ** In economic analyses, these values were reduced by 2% due to hydroelectric outage factor. STONE & WEBSTER A TABLE 9.3-3 EXCESS HYDROELECTRIC POWER SOLD TO CVEA* CORDOVA LEVEL 2 (HIGH) LOAD VALDEZ-GLENNALLEN LOW-GROWTH LOAD CVEA Load Minus CVEA Load Supplied by Excess Hydroelectric Power, 103 MWh CEC_Load, CVEA Load, Solomon Gulch Silver Allison Van Tiekel River Year 103 MWh 103 MWh Output, 103MWh Lake Lake Cleve RM 11.3 RM 13.5 1982 18.2 47.2 Cae: - - - - ios 1983 20.5 48.1 ok - - - - - 1984 21.2 49.1 Col: - - - - - 1985 23.0 SO edu 9.1 - - - - - 1986 23.9 Sie 10.1 10.1 8.3 10.1 10.1 10.1 1987 24.4 52.1 11.1 aakeat 7.8 lee: eee Lo 1988 27.4 S32 bene ese 4.8 2c 12.2 12.2 1989 28.4 54.2 13.2 13.2 3.8 istee 13.2 D302 1990 29.8 5563 14.3 14.3 2.4 14.3 14.0 14.3 1991 31.7 56.4 15.4 15.0 0.5 15.4 1201 15.4 1992 34.1 57.5 16.5 12.6 - 16.5 9.7 16.5 1993 35.7 58.7 17.7 11.0 - 17.7 Bor vee foye 1994 37.0 59.9 18.9 9.7 - 18.9 6.8 18.9 1995 38.2 61.1 20.1 8.5 - 20.1 5.6 20.1 1996 39.7 62.3 21.3 7.0 ~ 2is3 4.1 21.3 1997 41.1 63.5 22.5 5.6 - 22.5 Zell 225) 1998 42.9 64.8 23.8 3.9 - 23.8 1.0 22.9 1999 45.1 66.1 25.1 1.6 - 25.1 - 20.6 2000 47.1 67.4 26.4 - - 26.4 - 18.6 2001 48.7 68.8 27.8 - - 27.8 - 17.0 2002 50.9 70.1 29.1 - - 29.1 - 14.8 * Solomon Gulch output = 41,000 MWh/yr; Silver Lake output = 46,700 MWh/yr; Allison Lake output = 32,200 MWh/yr; Van Cleve output = 170,000 MWh/yr; Tiekel (RM 11.3) output = 43,800 MWh/yr; Tiekel (RM 13.5) output = 65,700 MWh/yr ** In economic analyses, these values were reduced by 2% due to hydroelectric outage factor. STONE & WEBSTER A A1082042 DIESEL ENERGY, 102 MWh LAKE 1488 DIESEL Figure 9.3-1 SMALL HYDROELECTRIC COMBINATION 3, CORDOVA LOW-GROWTH SCENARIO STONE & WEBSTER A A1082040 = = = 7 ° = > oO a wi 2 wi LAKE 1488 DIESEL Figure 9.3-2 SMALL HYDROELECTRIC COMBINATION 4, CORDOVA LOW-GROWTH SCENARIO STONE & WEBSTER A A1082041 CRATER LAKE ENERGY, 102 MWh DIESEL . SHEEP RIVER LAKES Figure 9.3-3| SMALL HYDROELECTRIC COMBINATION 5, CORDOVA LOW-GROWTH SCENARIO STONE & WEBSTER A 10.0 COMPARISON OF ALTERNATIVES 10.1 GENERAL The technical and environmental evaluation discussed in the Interim Feasibility Assessment remains unchanged. The revised economic evaluation of the most competitive generation alternatives was performed based on a low, mean, and high demand forecast for Cordova (CEC) and a low, mean, and high demand forecast for the Cordova-Valdez-Glennallen Region (CEC & CVEA). The sale of excess power to CVEA is sensitive only to the low Valdez-Glennallen demand forecast. This addendum provides an evaluation of the most competive generation alternatives to supply power for demand forecasts with low rates of demand growth not previously considered in the Interim Feasibility Assessment. The load forecasts considered do not include space heating. The economic evaluation of the most competitive generation alternatives was previously performed for higher demand forecasts in the Interim Feasibility Assessment and has not been repeated. The economic comparison has been revised to include: - ° The change in the CEC diesel fuel cost to $1.0695/gallon o Diesel generation waste heat o The hydroelectric site costs associated with land and damages, and reservoir clearing o The revised operations and maintenance costs for each hydroelectric site and its associated transmission line 10.2 ECONOMIC RANKING In Section 9 of the Interim Feasibility Assessment and this Addendum, the present worth of the capital costs was developed for all alternatives considered as viable solutions for Cordova's energy needs. The purchased power alternative was not considered in the addendum due to its high present worth cost when compared with other alternatives in the Interim Feasibility Assessment. STONE & WEBSTER A The "cost ratio" depicting the relationship of a generation alternative to the present worth value of the diesel base case were used for comparison purposes in the Interim Feasibility Assessment. This addendum discontinues the use of "cost ratios" and utilizes benefit/cost ratios to compare and rank generation alternatives. Tables 10.0-1, 10.0-2 and 10.0-3 show the best generation alternatives of the Interim Feasibility Assessment plus the Van Cleve and two Tiekel River hydroelectric alternatives for each electric load forecast. Present worth costs and benefit/cost ratios are provided for each alternative. These three tables are further summarized on Table 10.0-4, which present only the most competive generation alternatives. 10-2 STONE & WEBSTER A TABLE 10.0-1 BENEFIT/COST RATIOS CORDOVA LOW-GROWTH LOAD Case Diesel Base Case Subsidiary Present Net Present Worth Cost, Worth Benefit, Benefit/ Millions of $ Millions of $ Cost Ratio (w/o Waste Head Recovery) 117.8 - 1.00 Diesel Base Case (w/Waste Heat Recovery) 117.8 0.6 1.01 Coal-Fired Option 123.0 - 0.96 Silver Lake Hydro (9 MW) + Transmission 103.3 - 1.14 Small Hydro + Transmission: Combination 3 92.2 - 1.28 Combination 4 89.3 - 1.32 Combination 5 104.9 - 1.12 Allison Lake Hydro + Transmission 11955 - 0.99 Tiekel River Hydro + Transmission: River Mile 11.3 676.0 - 0.17 River Mile 13.5 636.7 - 0.19 Sell Excess Hydro Power to CVEA: Silver Lake (15 MW) + Transmission 113.1 45.8 1.45 Allison Lake + Transmission 119.5 13.9 1.10 Van Cleve Lake + Transmission 508.7 65.4 0.36 Tiekel River Mile 11.3 + Transmission 676.0 40.1 0.23 Tiekel River Mile 13.5 + Transmission 636.7 65.4 0.29 Notes: 1. Sale of excess power to CVEA is based on the Valdez-Glennallen Low-Demand Forecast. 2. Benefit/ = Base Benefit + Subsidiary Benefit Cost Ratio Base Benefit* = Diesel generation present worth cost Subsidiary Benefit* = Present Worth Cost* Present Worth Cost Subsidiary net present worth benefit which represents the cost of diesel fuel or heating oil saved. Present worth cost of the generation alternative *Obtained from Economic Computer Output STONE & WEBSTER A TABLE 10.0-2 BENEFIT/COST RATIOS CORDOVA MEAN-GROWTH LOAD Subsidiary Present Net Present Worth Cost, Worth Benefit, Benefit/ Case Millions of $ Millions of $ Cost Ratio Diesel Base Case (w/o Waste Heat Recovery) 141.9 - 1.00 Diesel Base Case (w/Waste Heat Recovery 141.9 nats 1.01 Coal-Fired Option 140.8 - 1.01 Silver Lake Hydro (9 MW) + Transmission 104.6 - 1.36 Small Hydro + Transmission: Combination 1 122.1 - 1.16 Combination 2 118.0 - 1.20 Allison Lake Hydro + Transmission 132.0 - 1.08 Tiekel River Hydro + Transmission: River Mile 11.3 677.2 - 0.21 River Mile 13.5 638.0 - 0.22 Sell Excess Hydro Power to CVEA: Silver Lake (15 MW) + Transmission 114.3 28.7 1.49 Allison Lake + Transmission 132.0 4.8 1.11 Van Cleve Lake + Transmission 509.9 65.4 0.41 Tiekel River Mile 11.3 + Transmission 677.2 22.4 0.24 Tiekel River Mile 13.5 + Transmission 638.0 62.8 0.32) Notes: 1. Sale of excess power to CVEA is based on the Valdez-Glennallen Low-Demand Forecast. 2. Benefit/ = Base Benefit + Subsidiary Benefit Cost Ratio Base Benefit* = Diesel generation present worth cost Subsidiary Benefit* = Present Worth Cost* Present Worth Cost Subsidiary net present worth benefit which represents the cost of diesel fuel or heating oil saved. Present worth cost of the generation alternative *Obtained from Economic Computer Output STONE & WEBSTER A TABLE 10.0-3 BENEFIT/COST RATIOS CORDOVA LEVEL 2 (HIGH) LOAD Subsidiary Present Net Present Worth Cost, Worth Benefit, Benefit/ Case Millions of $ Millions of $ Cost Ratio Diesel Base Case (w/o Waste Heat Recovery) 176.2 - 1.00 Diesel Base Case (w/Waste Heat Recovery) 176.2 V3 1.01 Coal-Fired Option 166.5 - 1.06 Silver Lake Hydro (15 MW) + Transmission 123.1 - eS Small Hydro + Transmission: Combination 1 139.7 - 1.26 Combination 2 138.3 - 1.27 Allison Lake Hydro + Transmission 167.8 - 1.05 Tiekel River Hydro + Transmission: River Mile 11.3 692.0 - 0.25 River Mile 13.5 638.7 - 0.28 Sell Excess Hydro Power to CVEA: Silver Lake (15 MW) + Transmission 123.1 9.9 1.51 Allison Lake + Transmission 167.8 2.0 1.06 Van Cleve Lake + Transmission 510.6 65.4 0.47 Tiekel River Mile 11.3 + Transmission 692.0 8.1 0.27 Tiekel River Mile 13.5 + Transmission 638.7 42.0 0.34 Notes: 1. Sale of excess power to CVEA is based on the Valdez-Glennallen Low-Demand Forecast. 2. Benefit/ = Base Benefit + Subsidiary Benefit Cost Ratio Present Worth Cost Base Benefit* = Diesel generation present worth cost Subsidiary Benefit* = Subsidiary net present worth benefit which represents the cost of diesel fuel or heating oil saved. Present Worth Cost* Present worth cost of the generation alternative *Obtained from Economic Computer Output STONE & WEBSTER A TABLE 10.0-4 PRESENT WORTH COSTS AND BENEFIT/COST RATIOS BEST GENERATION ALTERNATIVES PRESENT WORTH COST (MILLIONS OF $) BENEFIT/COST RATIOS3 LEVEL 2 LEVEL 2 * CORDOVA LOAD PROJECTIONS: LOW MEAN (HIGH) LOW MEAN (HIGH) CASES 1. Diesel Base Case (w/o Waste Heat Recovery) * 117.8 141.9 176.2 1.00 1.00 1.00 2. Diesel Base Case (w/Waste Heat Recovery) * 117.2 140.6 174.9 1.01 1.01 1.01 3. Coal-Fired Option 123.0 140.8 166.5 0.96 1.01 1.06 4. Small Hydro & Transmission 89.3. 118.0 138.3 1.32 1.20 Nee 5. Silver Lake & Transmission 103.31 104.61 123.12 1.14 1.36 1.42 6. Silver Lake & Transmission Sale of Excess Power to CVEA** 67.32 85.62 113.22 1.45 1.49 1.51 * Diesel Fuel (Oct, 1982) - $1.0695/Gallon, Fuel Escalation 2.6% per APA FY 82 Criteria ** Valdez-Glennallen Low-Demand Load Benefit calculated using CVEA diesel generator fuel rate of 0.0769 gallons/kWh produced and the 1982 CVEA diesel fuel cost of $1.03/gallon (escalated at 2.6% per year). al 9 MW installed capacity 2 15 MW installed capacity 3. See Tables 10.0-1, 10.0-2 and 10.0-3 for calculation of Benefit/Cost Ratio STONE & WEBSTER A 11.0 CONCLUSIONS AND RECOMMENDATIONS 11.1 CONCLUSIONS Two alternatives, Silver Lake and a combination of small hydroelectric sites, are the most competitive sources of energy to meet Cordova's needs. As shown on Table 10.0-4, the small hydro alternative has the lowest present worth cost for the one case of the lowest load projection supplying the Cordova load only. Silver Lake provides a single energy source requiring one-time development while the small hydro alternative would require the development of two or three sites. From a regional viewpoint, Silver Lake is clearly the best alternative. With credit for excess hydroelectric power to replace Copper Valley's anticipated diesel generation, the cost advantage for Silver Lake over the small hydro alternative is significant. Silver Lake remains the "best cost" alternative. The field investigations conducted at Silver Lake have confirmed that the site does not have an environmental or geotechnical fatal flaw and appears technically and environmentally suitable for hydroelectric development. 11.2 RECOMMENDATIONS Based upon the further analysis presented in this addendum, Stone & Webster Engineering Corporation continues to recommend that the optimization of the Silver Lake hydroelectric project be pursued during the second phase of this study as the preferred plan for meeting Cordova's future energy needs. The project would include an overhead transmission intertie between Cordova and Solomon Gulch and a transmission tap to Silver Lake. The Silver Lake Project remains the "best cost" alternative with the highest benefit/cost ratio on a regional basis, and a feasibility study of this alternative is appropriate. STONE & WEBSTER A APPENDIX Table of Contents MEETINGS AND COMMENTS ASSESSMENT COST ESTIMATES ENGINEERING MEMORANDA APPENDIX MEETINGS AND COMMENTS Preface This Section of the Appendix contains reports of scheduled public meetings and agency comments after June through October, 1982, on the Cordova Power Supply Interim Feasibility Assessment. Contents 1. Public Meeting September 22, 1982 Cordova 2 Agency Comments June 28, 1982 Chugach Natives No response required July 13, 1982 Cordova Electric Cooperative For response see Cordova Public Meeting Notes, September 22, 1982 July 20, 1982 City of Cordova For response see Cordova Public Meeting Notes, September 22, 1982 July 26, 1982 Eyak Corporation Letter on Wood Fired Electrical Generation September 8, 1982 SWEC Response to Eyak Corporation July 26, 1982 Letter July 30, 1982 Department of Energy Letter on Interim Feasibility Assessment APA Response to Department of Energy August 9, 1982 Department of Energy Letter on Interim Feasibility Assessment APA Response to Department of Energy August 17, 1982 Division of Management and Budget, Office of the Governor, State of Alaska October 14, 1982 SWEC response to August 17, 1982 Memorandum from the Division of Management and Budget October 11, 1982 Alyeska Pipeline on PRT No response required October 25, 1982 Board of Directors of the Cordova Electric Cooperative resolution urging legislative funding and construction of the Silver Lake Hydroelectric Project and construction of a transmission line from MEETING: Public Meeting - Cordova DATE: September 22, 1982 LOCATION: Cordova Public Library meeting rooms PURPOSE: To present the study findings, update attendees on findings from recent field investigations at Silver Lake and discuss possible State finanacial support options and cost of electricity to the consumer. ATTENDEES: See attached list PRESENTATION: P. Lovett (Cordova) introduced those to make presentations and informed audience of purpose of meeting. N._K. Whitcomb (SWEC) briefed attendees on the work which had taken place since the April 21, 1982 Public meeting and on the results of the study in which development of a hydroelectric project at Silver Lake to supply the needs of Cordova and the CVEA region is recommended. R. Dagon (DOWL) briefed the attendees on their findings to that point of the field investigations being conducted at the Silver Lake Site. The field investigation included environmental and geologic data gathering. The field investigations indicated favorable environmental and geotechnical conditions for construction of a dam at the mouth of Silver Lake. Mr. Dagon presented slides of the lake, proposed dam site, penstock and access road route and a proposed barge dock site. D. LaRue (Dryden & LaRue) discussed the transmission routes studied and the reasons for the route selected for the Silver Lake project. E. Yould (APA) briefed the attendees on how the State participates in the funding of hydroelectric projects, what level of participation has occurred on other projects, and the activities and support required from Cordovans to obtain State participation. Two charts were presented which indicated the consumer cost of electricity for a range of assumed State participation. Mr. Yould emphasized that the consumer cost of power would probably not decrease immediately, although some drop-off might occur as Silver Lake's capacity was fully used, but that power cost would then remain constant over the years in which large savings would be realized compared to diesel generation. During all of the presentations questions were asked by the attendees into the details of the data and information being presented. Both APA and SWEC recommended strongly that Cordova support the Silver Lake project. Mr Bechtel of CEC showed support for the project while recommending that Cordova be tied by transmission to the Railbelt area. Tog Mee [ING - Lobrevn Aibeney CoRObVH ENERGY ALTERNATIVES Seo ag ere ATTENDANCE & Ze yovro - Awsices (buele A. "TY Lie Wate wtG14N1 a 22 * ef Aban kizaend - StoweZ Waters Exute. Cont > Bw SHAvaNess - sf 4 “ ae ee phen = = 2D inss: Paes Der hake - Lay pen ¢ kalo (200 iy ewan, = Comoe Sly Nee (Oba Beth = FAR = CEC Rica Sames Ed Ken Sat Mle Pa mcigt Mek ap nia nee pe reas ata Qi (Jow Ph) jj — Mfpitid. face Cort, he ferreg D. Aovert Owe (avager Ce CXivere Osborn EhryScian (on <lec. Board. ) Grdoyo Dotty Con 6 kn faclisrie. On CRA wD CafyWA MO Grado Ei, Sime ecteie (CEC Bevel) Corda NiCHARD W, GRoFF Vice -Mp-teR. oF Cop rovA- Die Kaki! M ANB BS A_ ee iar W3 Sey CHUGACH NATIVES, INC. 903 WEST NORTHERN LIGHTS, SUITE 201 » ANCHORAGE, ALASKA 99503 (907) 276-1080 TELEX 26-497 June 28, 1982 Mr. Eric Yould, Executive Director Alaska Power Authority 334 W. Fifth Avenue Anchorage, AK 99501 Dear Mr. Yould: In the Interim Feasibility Assessment report of Cordova's Power Supply released earlier this month, the APA, through its consultant Stone & Webster Engineering Corporation, recommended the pursuit of a hydro- electric facility at Silver Lake as its preferred alternative. This facility would then be connected by overhead transmission line to an intertie running between Cordova and Solomon Gulch. This facility would have an installed generator capacity of approximately 15 MW, and an estimated capital cost (in 1982 dollars) of approximately $89 million. On June 8 the announcement of a settlement in principle between Chugach and the federal government covering our land claims was made. One feature of the settlement provides for 55,680 acres at Silver Lake to be transferred from the Forest Service to Chugach. This area includes Silver Lake in its entirety, a large part of its watershed, the pro- posed dam site and the proposed location of the powerhouse. The purpose of this letter is to inform you that our corporation is in full support of the development of the Silver Lake hydro project. Ne have already begun working with Mr. Bruce Bedard of your staff in his capacity as Native liatson officer for the APA, and with the Forest Service in their issuance of the necessary special use permit to OOWL Engineers for the 1982 fieldwork. We believe that private ownership of this property may in fact serve to expedite your federal licensing re- quirements, and thus be of benefit to APA, Chugach, and all future users of the electricity generated by this project. Please don't hesitate to contact me or my staff if you have any further questions concerning Chugach's involvement in this project. Sincerely, * ~ Sda- ery Edgar Blatchford, Chairman cc: John Allen, Tatitlek Corporation R. J. Kopchak, Eyak Corporation R Norman K. Whitcomb, Stone & Webster ECEIVED Perry Lovett, City of Cordova JUL 1 1882 Doug Bechtel, Cordova Electric Cooperative Reed Stoops, ONR Aas‘ No Response Required , Ap " QRDOVAELECTRIC GOPERATIVE | REC Box 20 * Cordova, Alaska 99574 © 424-3131 July 13, 1982 Mr. Eric A. Marchegiani ' Project Manager Alaska Power Authority 334 West Fifth Avenue Anchorage, AK 99501 Dear Eric: The Board of Directors of Cordova Electric Cooperative spent a considerable amount of time at their meeting last night discussing the future of our alternative energy study currently underway. In such a broad area, it is difficult for the Board to come up with a precise direction for your continued efforts. I want to give you a general concensus of their feelings. First, the Board concurs with the recommendation of Stone and Webster that we continue to investigate the Silver Lake Hydro-electric site. The Board also believes that a transmission line intertie extending from Cordova to Anchorage (Susitna) will ultimately be built. The Board did request that the Power Authority and Stone and Webster move at an early date to come up with a definite contractual agreement with Chugach Natives, Inc. for the Silver Lake site. We do not foresee any problems in coming to an agreement with Chugach Natives over this site, but feel that it is in everyone's interest to address it at this stage rather than a year or more down the road. The Board also expressed concerns over the environmental impact/land right-of-way of the transmission line between Valdez and Cordova. There was a significant amount of feeling on the Board that the submarine transmission line be kept on a back burner in case an overland route proves not feasible. tel Les, 7 Mr. Eric A. Marchegiani Page Two ae The Board also felt that a 98 percent availability of overhead transmission lines is optimistic and, while the mean time to repair submarine cables is longer, its increased reliability might offer some advantages. The Board discussed the problems of tapping into a DC transmission line for Silver Lake or Tatitlek and realizes that there are obstacles. We support your efforts to keep this project moving along during the summer for data collection. If there is anything further we can do to help you, please let us know. Sincerely, , W. D. Bechtel General Manager WDB: vjc Mr. Norm Whitcomb Stone & Webster For Response See Cordova Public Meeting Notes, September 22, 1982 Box 1210 602 Railroad Avenue Cordova, Alaska 99574 = Phone: (907) 424-3237 or 424-3238 “The Friendly City” James A. Poor July 20, 1982 Mayor Eric P. Yould, Executive Director Perry D. Lovett, Alaska Power Authority Manager Suite 31 5 as 333 W. 4th. Avenue jonna M. Sherby, Cae Anchorage, AK 99501 Danaweee Dear Mr. Yould: Jay Synum aoa: The Cordova City Council at its regular meeting of July 19, 1982 Garry Purnis addressed the Cordova Alternate Energy Study Phase I. These Joe Gunderson recommendations for study and action in Phase II are: 1. Continue study of Silver Lake Hydro Site. 2. Immediately begin negotiations with Chugach Natives Inc. to obtain right-of-way for lake impoundment Power house and transmission lines. Obtain right- -of-way from Eyak Corporati on for transmission lines where required. 3. Pursue the Teeland Intertie. y The Council believes that the Teeland Intertie is the long-range 2 solution’ to Cordova's energy needs and should be diligently uy pursued. They further feel that the right-of-way issue should — be resolved immediately at Silver Lake. There is no need to S continue investigation of this alternate if it is determined that = the cost of land is prohibitive. CNI has indicated strong support > of the project and willingness to cooperate. it is essential that = the right-of-way be resolved at this time while they are ina = cooperative stance, and before any further funds are expended s other than the most essential environmental surveys. oe S g Attached are copies of CNI's letter, my memo to Council and Cordova Electric Cooperative's memo to Eric Marchegiani. Again, we encourage haste in resolving the right-of-way issue. Very truly yours, ity Manager Attachment: Lovett's memo 7/19/82 cc: OD. Bechtel, CEC CNI letter of 6/28/82 “ Norm Whitcomb, Bechtel's letter 7/13/82 Stone & Webster James A. Poor Mayor Perry D. Lovett, Manager Donna M. Sherby, Clerk / Treasurer Council Members Don Narrance Jay Bynum Richard Groff KJ. Ropehais Garry Purvis Joe Gunderson Box 1210 602 Railroad Avenue Cordova, Alaska 99574 Phone: (907) 424-3237 or 424-3233 “The Friendly City” July 19, 1982 To: Mayor & City Council From: City Manager Re: Alternate Energy Alternative Selection After reviewing the materials presented in the Study conducted by Stone and Webster, it is my opinion that in the long run the best alternative is to construct the Teeland Intertie. This would put Cordova on a grid that would include either future gas at Fairbanks, hydro at Susitna or coal in the railbelt area. At present the Silver Lake hydrosite should be investigated fruther as recommended by Stone & Webster. Emphasis should be placed on immediate negotiation with the Chugach Natives, Inc. to secure either a longterm lease, purchase or possible state trade of land for the right-of- way necessary for both the impoundment area and the right-of-way for the transmission line. CNI has expressed a willingness to cooperate. It should be noted that the Silver Lake area was included in the land settlement after Stone and Webster had identified it as a hydro site, and with CNI's letter indicating support for the project the right-of-way details should be handled at this time while everyone is in general agreemant. I would suggest that the Teeland Intertie and the Silver Lake Hydro site be selected as the alternates to study further together with immediately addressing the right-of- way question. cc: Eric P. Yould, Executive Director APA Att: CEC letter of 7/13/82 For Response See Cordova Public Meeting Notes, September 22, 1982 THE EYAK CORPORATION July 26, 1982 Alaska Power Authority RECEIVED 344 West 5th Ave. Anchorage, AK 99501 JUL 29 1982 ALASKA POWER 4 Dear Sirs: UTHORITY I have reviewed Phase 1, Cordova Power Supply Interim Feasibility Assessment. In general I find the document satisfactory and the recommended alternative acceptable. To a point, the establishment of a sincle large facility is much more acceptable to me, both environmentally and logistically, than several smailer facilities. Also I support designs that minimize detrimental impacts on fisheries through preventative measures ,such as a ven stock outlet above spawning areas and water mixing intakes for discharge water temperature control. : ; At this time however, it appears that your Graft feasibility study is incomplete. .I suggest that its deficiencies ce corrected in Phase II. I refer to: ; 1) . The need for study of a Thermal Differential Generation System, to be built near Scott Glacier 10 miles from Cordova, taking advantage of the temrerature differential between the area's ground water and the glacier's water. And more importantly: . 2) The need for a study of a olant to burn pelletized wood oroducts. Innovative design would allow the plant to help alleviate Cordova's waste disposal problem and would also provide an optisn to convert or utilize coal if and when that product becomes cost effective. Currently the Eyak Corporation holds title to over 63,000 acres of land around the Cordova area. Additionally, 52,000 acres are to be conveyed in the mear future. Over 40% of these Lands contain commercially harvestable volumes of timber. Gross estimates of the timber on these lands exceed 1,200 million soard feet, or 100 million cubic feet of volume. P.O. BOX 340 CORDOVA, ALASKA 99574 (907)424-7161 THE EYAK CORPORATION Eyak Corporation would like to provide the . wood product for the pelletized plant, and as such . - would like to become involved in the feasibility study. Additionally, other woods product sources exist on both private and federal lands. Overall interest in developing the resource is high. Large amounts of currently unmerchantable or un-exportable material, which currently make up the majority of the area's timber stands, are available. If the plant needed 144 million Btu daily for average production, that energy demand could be met by 800 cubic feet of local wood product. Yearly consumption would be in the 3C€0,000 cubic foot range which is equal to about 3.5 million board feet. That amount of yearly harvest would - be feasible on Eyak lands assuming the gross volume would be used, including tops, limbs, and cull logs. I urge you to conduct a detailed feasibility study of a wood fired system as Evyak is in earnest in providing that wood source. The local hires related to narvest would be an important added consideration. The use of a renewable resource, especially one which currently has no other market, is very important in Alaska. In this day when the State of Alaska is concerned with the export of its non-renewable resources anc its dependence on imports, the development of its cwn resources is of utmost importance. I feel it is imperative that a wood fueled boiler be included in this state funded study. The Eyak Land Department is ready to lend assistance as needed. Sincerely, Thomas G. Somrak Lands Manager P.9.BGX 240 CORDOVA, ALASKA 99574 (907)424-7161 ett oaer ALASKA POWER AUTHORITY 334 WEST 5th AVENUE - ANCHORAGE, ALASKA 99501 Phone: (907) 277-7641 (907) 276-0001 September 21, 1982 Mr. Thomas G. Somrak Lands Manager The Eyak Corporation P.0. Box 340 Cordova, AK 99574 Dear Mr. Somrak: Please reference your letter of July 26, 1982, to the Alaska Power Authority concerning a Thermal Differential Generation System and the possibility of utilizing wocd as a source of energy to meet Cordova's energy requirements. Unfortunately I have been unable to respond to your letter sooner; but I felt thet the two areas of concern you raised needed to be investigated in more detail. I requested the Power Authority's consultant, Stone & Wepster Engineering Corporation, to investigate both areas. The Therial Generation System is still in the research and develonirent piiase and thus the performance, reliability, anc cost effectiveness are yet to be proven. Since there is no commercially available ans oF acai systen and the technology has yet to be proven, this aiternetive be considered wurther at this tine. {Use of an unpro technole could even cost residential consumers more than other a iternutives. ) The wood fired power plant was the seccnd alternative which you proposed. Please refer to the enciosec Stone & Webster letter dated (September 8, 1982) to me, concerning your letter. The letter cutlines the various assumptions which were made about the wood plant and provides a summary of the computer output (also enclosed) in Table 1 ana graphed on Figure 1. Figure 1 jilustrates that the Silver Leake hydroelectric development for providing energy only to Cordova is better than the high wood plant capital costs. If one considers the low wood plant capita) costs, then the price of wood must drop below $10/ton ($12.50/cord) before the wood generation eiternative is more cos effective. This price for the wood is unrealistically low considering that the costs of the wocd would also have to inciude a transportation cost. If the Silver Lake alternative provides excess energy to Copper Vailey~Electric Association, which is expected to occur if the project is developed, then the Silver Lake alternative is better than either the high or low wood plant capital cost. Therefore, it appears that the Silver Lake alternative will provide capacity and energy to the people of Cordova at a lower cost than a wood generation pliant. Mr. Thomas G. September 21, Page 2 FOR THE EXECU Somrak 1982 JOL TTY Hl E DIRECTOR » of answered your to contact me. Cordove STONE & WEBSTER ENGINEERING CORPORATICN 7 < i> & Mr. Eric P. Yould September 8, 1982 Executive Director alasxa Power Authority J.0. No. 14101.29 324 Wd. Stn Avenue Letter No. SnEC/APA=21 | anchcrage, Alaska ¢9501 Attn: Mr. Erte Marcnegiani Project Manager f Dear Eric: THE EYAK CORPCRATION cULY 26, 1952 LETTER t CORDCVA PCwER SUPEI we have prepared a response to the ietter received frem Mr. Thomas G. Scmrak of the Eyak Corporation (dated July 26, 1582) containing ccm=ments on the Phase I Corcova Power Sucply Interis Feasibility Assessment Rescrt. “nr. Somrak suggested that tne Power Authority ccnsider two acaitional power supply cptions for Corcova. These included: 10) Fe 10 ie a Thermal Differential Generaticn System to be built near Scott Glacier which would cperate on the temperature differential Setween tne glacial seit anc the lecal grcouncwater, and 2e a steam power pliant fueled by pelletized weed frem Eyak Corporation rerest lancs. First, in regara to the Thermal Generation Systen, federally-funded researcn anc development nas ceen underway fcr seversi years cn a sizilar concept, Ccean Thermal Energy Conversion (OTEC). OTEC systems use the thermal gradients between the warms surface of the oceans and the cocler temperatures of the ocean depths to produce electrical pcower. The CTEC power conversion equipment would be very similar to that for a systen operating on the grouncwater/glacial melt thermal cifferential. ‘uch of one power conversicn equipment is still in the research and develcpment Stage, with performance, reliability, ana firm cost data yet to be oe li Wita recent federal funding cutbacks in the CTEC program, it i3 unclear as to tne ruture cate when these systems will be fully developed and commercialiy availiable fer installation. fcr these reasons, SwcC recommends that the concept nct se considered further at this tine ror Cordova. STONE & WESSTER ENGINEERING CORPORATION rcueglana . ceptenoer 6, 178 Page 2 Regaracing tae second 3sugssstion, owae sas perrsrmec a orief assessment of a wocg=fired power Plait cased cn tae Folscwing ass t2023: 1. The capital cost of two d= woou-iirec units would de tae same as Yor tae equivalent coal units except tnat no lrice-sus acruoocer syStem woula ve required; ee due to cifferences in heat content of wood and coal, tre requiree fuel rate for tne wood-rirec plant woula oe cus greater tuan ror a coal-rired plant; Se tae operation ana maintenance costs fcr the anocd-ilred plant, aster cesag adjusted for tae wood ruei rate ane asa cispesai, wCuld oe essentially icentical to tre coal plant costs. scononic evalustions were dace for a weccer:redc power Piast raving tet Orin waits. ine setnocoicwgy and economic parameters useu were as cescrioec in section y.U of tre interim Feaslviicsty assessment aeport. ise evaluation was pervormeu for several crfrerent wood ruel prices (tais price wou. represent aesivereu, pelletices wcca at the power Diant) plus 2isn and icw capital cost estimates for tre wood=firgc piant. Tue capital cost variation resuits from cirferences in a3ssumea 3ite preparation Dequirements. ‘ise present wortn of tne woou-fired pcewer piant lifeecyc.e costs are display2u ia Tadie 1. These results sinoula Se compares to tue present worta costs for otser power supply options 3nown on paze 10-9 of the iaterim reasiviiity assessment. Tne eccnomae c Pintouts for tre wood-fired power pliant are attacaed for your 2 omputer arormaticn. visgare 1 sbows tne present worta cost versus wocd price for the wocderire plant. Present worts costs for tne Siiver Lace sycroelectric Pianat are aiso snown on figure 1, wita ane witncut tae propusea 3aie of sxcess power tO tae Copper Vailey zlectric Association (cVea). i: cae excess Siiver make Power is solu to CVba, cnen tae present worte cost cr Sliver vaxe is igss taan that or tse woouefired power plant, even if tae wocd cSuel is free. However, if 24cesS oilver Laxe power canact ve soica to UVsa, 4 Woodefired pewer piant (low capital cost estimate) would 3e competitive cniy if ceiavered pellatic wood costs $10 per ton or iess. Althougn tuere is uncertainty regarding tne delivered, pelletized wocu cost in vorcova for a larseescala timoer harvesting cperation, sweC expects Suet tae finai cost would oe sisaificantiy sreater taan $10 per ton. ia acdaticn, tne envirenmental impact of suco a tinoer aarvesting cperation cannot oe fruliy icentaried at tars time, out severe impacts can de anctocipatea. bce conciusions ciscussed in Section 11 of tne ianteria jf Assessment ave act deen alcerec sy tnis anely3is or a da power plant. cweC stiil recommends ciat Sluver uade oe pUrsusd ML22IZ CasZe 24 OF TIS sbucy aS Gue preiepres cption ror Deeting biz Tuture ceicCtricai power seeds of vordova. STONE 4 WEBSTER ENGINEERING CORPORATION 4r. arcnesian2 seotenver 6d, 140 Page s -F you or wir. Somrax nave any questions, piease co not Awsitate to ccutacc =e. Very truly yours, Mi = YO04) — Shaugnnassy wey oS we Ne. Ke whitcomd Project Manaser ural 1B/1L5 ! astacsaents > \ STONE 3 WEBSTER ENGINEERING CORPORATION 2 oN £ TASLE 1 PRESENT WORTH CCSTS FOR WCCD-FrIRED PCRER PLANT 1962 CCLLARS ‘ - aCGD COST, PRESENT WORTH, $102 ' S/TCH 23 APITAL COST* Loh CAPITAL CCST? 5 121,807 93,013 le 138,014 109, 266 32 154,362 125,796 7 36 170,707 142,083 bi 187,053 158,399 4Capital cost variation is cue to aifferences in assured site preparation requirements. Aog82011 200 HIGH WOOD PLANT CAPITAL cost * 175F ‘o LOW WOOD PLANT a CAPITAL COST * & 150 ° oO xr = a g . * CAPITAL COST 2 VARIATION IS DUE TO w 125)- DIFFERENCES IN SITE ie PREPARATION eS HEQUIREMENTS SILVER LAKE 100 HYDRO SILVER LAKE HYDRO PLUS 1S SALE OF EXCESS TOCVEA 0 10 16 32 48 64 $/TON 0 12.5 20 40 60 80 $/CORD wooD Cost PRESENT WORTH COSTS FOR WOOD-FIRED POWER PLANT COMPARED TO SILVER LAKE HYDROELECTRIC PLANT LEVEL 2 CORDOVA SPACE HEAT LOAD FIGURE 1 THE WOOD-FIRED POWER PLANT ECONOMIC COMPUTER PRINTOUTS ARE CONTAINED IN THE ADDENDUM 1 SUPPLEMENT ECONOMIC DATA- PART 1 d Department Of Energy Alaska Power Administration P.O. Box 50 Juneau, Alaska 99802 July 30, 1982 Mr. Eric Yould \ Executive Director \ Alaska Power Authority \ 334 West 5th Avenue, 2nd Floor i Anchorage, AK 99501 ' Dear Mr. Yould: AULD We have reviewed the Cordova Power Supply, Interim Feasibility Assessment, June 1982, prepared by Stone & Webster Engineering Corporation, and have the following comments. The report contains very little information on the plans evaluated and the specific design and cost assumptions used. It could be that this information is available in supporting reports. We would urge a review to assure that the alternatives are evaluated on the basis of comparable design and cost assumptions. We were quite surprised that Stone & Webster found Silver Lake to be a much more economical project than Allison Creek. Allison seems to have a simpler development plan as well as significant advantages in ease of access for design, construction and operations. The environmental analysis also suggests Silver Lake would have more difficult fishery problems. The transmission routes between Valdez and Cordova appear to involve extremely difficult terrain, weather, and access problems. We would urge a careful review of the transmission feasibility and costs before Proceeding with more detailed studies. Some of the previous studies, including the Corp's work on Allison Creek, indicated excellent promise for a pressure reducing turbine (PRT) in the 2 Alaska pipeline. If it is accurate that the best alternative for Cordova involves interconnection with Valdez, then it might be desirable to consider earlier construction of the PRT. Thanks for the opportunity to comment. Sincerely, ae Robert J. Cross Administrator cc: W. Doug, Bechtel, Cordova Electric Cooperative, Inc. RY ALASKA POWER AUTHORITY 334 WEST 5th AVENUE - ANCHORAGE, ALASKA 99501 Phone: (907) 277-7641 (907) 276-0001 August 9, 1982 Robert J. Cross Administrator Alaska Power Administration P. 0. Box 50 Juneau, Alaska 99802 Dear Bob: Please reference your letter of July 30, 1982, in which you ex- pressed some surprise that Stone & Webster found Silver Lake to be more economical than Allison Creek. The Power Authority is presently reviewing the reports which you were sent as well as additional back-up (including cost estimates) used in preparing the report. Based on information provided in this report, the Power Authority is not irrevocably committed to Silver Lake. I have enclosed a copy of the technical and economic appendices along with | detailed cost estimates for Allison Creek, Silver Lake and the trans- mission line between Valdez and Cordova with a spur to Silver Lake. I would appreciate any additional comments you may have with respect to this additional data. Stone & Webster has expressed a technical concern regarding the development of the Allison Creek site. This concern is related to the geology of the tunnel. They believe that the tunnel material quantities estimated by the Corps were low; specifically, there is a large quantity of artesian water without a commensurate amount of concrete lining in the tunnel. The Corps also indicated in their geologic report that the artesian conditions in the lake tap area could pose problems during construction. The combination of these factors lead to a higher es- , timated cost of the Allison project than what was projected by the Corps. The proposed transmission line between Valdez and Cordova does traverse some very difficult terrain and is exposed to severe weather. The entire route was traversed by helicopter and a number of on-the-ground inspections were made by Dryden and LaRue and a transmission line construction contractor. The meteorologic data which was used to design the transmission line is contained in the technical appendix. This information should clear up some of your questions regarding the adequacy of design information. In either development of Allison Creek or Silver i Lake, a transmission system would be required to transmit power to Cordova. Robert J. Cross August 11, 1982 Page 2 Although the Pressure Reducing Turbine (PRT) appears to have favorable economics, the institutional constraints apparently have been so great that its development is still very much in question. Thank you for your initial comments. Any additional comments on this additional information would be very much appreciated. Sincerely, Eric P. Yould Executive Director cc: Norm Whitcomb, Stone & Webster ies MEMORANDUM - FROM: On File D. correr. Ais... See Robert Mohn, Director oar, = August 17, ATBE Ace . of Engineering NE Alaska Power Authority pees ; a 465-2213 George — Analyst SUBJECT: Cordova Power Supply Division of Budget and Management Interim Feasibility Assessment Office of the Governor Thank you for the opportunity to review the “Cordova Power Supply Interim Feasibility Assessment". Hopefully the following comments will heip achieve a Phase II study which complies with feasibility study statutes and regulations. Load Forecast - The interim report states that "SWMCI found it improbable that conversion to residential electric space heating would occur unless the cost of energy fell to less than 6¢/kwh from its current cost of approximately 20¢/kwh" (Appendix, p. 2). The report also states "CEC currently charges residential customers about 10¢/kwh for depreciation, operations and administrative costs. Therefore, even if hydroelectric power was free, the electric power cost to the customers would be a minimum of 10¢/kwh" (p. 9-10). Despite the unattractive cost of electric heat, the load forecast devotes considerable effort to speculating what demand for electric space neating may occur “if future electricity is provided at a significantly lower cost” (p. 4-2). A number of scenarios for conversion to electric space heating are described, which gives the impression that it's a question of now much rather than if. Figure 9.3-9 adds to this impression by plotting how long it would take for fuel oi] space heating to reach l10¢/kwn if fuel oi] experienced a real escalation of 4, 6, and 8% instead of the 2.5% fuel escalation rate provided by Alaska Power Authority (APA) criteria. No rational is given for such high fuel escalation rates. Also, the report does not verify, with actual data, its assumptions on Cordova's annual household energy consumption for space heating. “Conservation measures previously identified and recommended in the Reconnaissance study were not considered” (p.2-5). Nevertheless, the load forecast used to compare the total present cost of each alternative "is based on a moderate space heating scenario for Cordova" (p. 1-32). Present costs for a no space heating lcad forecast are also given but in the form of a sensitivity test rather than a most likely scenario. - The load forecast assumed that the 1MW load for Chugach Fisheries, which is now self-generated, would be added to the utilities load and “that an additional cannery would be constructed in 1992". (Appendix, p. 8). The report also states that “the number of processing plants in Cordova is also likely to remain constant since the plants have additional capacity or have the capability to increase their capacity “and” Cordova has ample freezing and cold storage facilities to handle present and future fish production". (Appendix, p. 6). It is mot clear whether the 1MW load represents current or potential demand or that an additional fish processing plant is needed. The load forecast relied heavily on an Alaskan OCS socioeconomics study for Cordova. The study assumed a mean-growth case “wnich is the expected growth based on the weighted average of limited petroleum exploration scenario and the growth associated with a scenario of significant discoveries and the development of an offshore terminal" (Appendix, p. 7). The mean-growth case may not be realistic. For instance, can one assume that there will be half of an offshore terminal. These assumptions need better description and, perhaps, separate load forecast for each scenario. The load forecast used 1981 as a base year and the report provided the actual data for that year. (It would have been useful to also provide actual data for the past five years in order to have some feel for what trends exist.) The 1981 actual data (energy - 16,000 Mwn and demand 3.8 MW) differred from the forecast data (17,500 MWh and demand 3.5 MW). Also, the report assumes that the peak demand will increase at a rate of 4.8% while Cordova Electric Cooperation forecasts an 8% growth rate. It would be useful to have a better understanding of peak demand. Pernaps some peak - shaving strategies need to be considered. Diesel Generation Tne diesel generation alternative used for the present cost analysis included 15MW of installed capacity. Cordova's peak demand for the year 2002 is expected to be 9.2 MW without electric space heating and 12.0 MW with moderate space heating. Given the unlikely occurence of electric space heating in Cordova, it is not reasonable to estimate the costs of diesel generation based on meeting a moderate space heating load. Fuel cost are presented for diesel generation but not the heat rate. This information should be included. The report concludes that the benefits of waste neat utilization from diesel generators is marginal even though there are nearby public buildings. No details are presented to support this conclusion. Is the waste heat distribution system optimized for cost-effectiveness or does it include buildings which are too distant from the powernouse to be economically feasible? Further studies should use the most recent price for fuel oil. If the recent reductions in fuel oil prices are not accounted for, the fuel escalation rate may be excessive. Silver Lake The report states that “the hydroelectric development proposed for Silver Lake is based on a 120 foot high concrete dam located at the lake mouth... At this time no fatal flaws have been identified which would prevent project development". However, the report also states that “Duck River, which drains Silver Lake, is one of the more productive salmon streams in the area. Assuming that the powerhouse is placed above the upper extent of spawning, a run-of-the-river hydroelectric facility should have minimal environmental impact. However, a project involving a major dam could seriously affect the fisheries resource." (al] quotes from p. 1-17 and 1-18). It appears as if the Silver Lake Project may have “fatal environmental fiaws." Also, possible impacts con fisheries during construction and reservoir filling are not adequately addressed. The Comparison of Alternatives section of the report evaluates Silver Lake (and all other alternatives) for several technical and environmental factors. The evaluation assigns either a preferred, acceptable, not acceptable or unknown rating. Despite the possible environmental impacts and lack of geotechnical data, the Silver Lake Project is given a rating of preferred or acceptable for all factors. t seems that an unknown rating would be more appropriate in many cases. A letter from the Alaska District Corps of Engineers states that "Several major errors and omissions in the cost estimate for the Silver Lake alternative are evident". "“Sased on similar size projects in remote areas, we believe that the $120,000 operating and maintenance cost is too low. When compared with similar size projects in remote areas with severe climate and topographic conditions, we believe that the modification and site preparation costs are unrealistically low, the $5.2 million cost for the dam and spillway is unrealistically low. The cost for lands and rights-of-way should be included as an economic cost. Similarly, the cast of an access road should be included." The Corps further states that “the report appears positively biased towards development of the Silver Lake site". [t appears is if the cost cf the Silver Lake Project may be somewhat higher than that provided by the report. If so, it is premature to strongly emphasize Silver Lake in future studies and exclude similiar emphasize on other alternatives, as recommended by the consultant. Smal] Hydroelectric Site The present cost of the small hydroelectric site alternative ($93.8 million) is nearly identical to the Silver Lake alternative ($92.9 million) without electric space heating. However, the data used for the present cost analysis is very preliminary and comparisons between alternatives may be premature. The cost for the small hydroelectric alternative does not include diesel reserve capacity nor does it adequately consider the importance of timing. Power Creek Coal The Army Corps of Engineers has been investigating the technical feasibility of the Power Creek hydroelectric site near Cordova. Apparently the site has a number of geotechnical problems which precludes the development of a large storage dam above Ohman Falls and limits the site to a run-of-the-river project. However the Corps of Engineers letter states that “the report draws subjective conclusions against hydropower development of this stream” and recommends that “the Power Creek alternative with diesel backup should be presented to the city as an alternative to be give consideration". It does not appear that the Power Creek alternative has been adequately considered or included in the small hydroelectric site alternatives. The report assessed several options for coal-fired electric generation. Because of "reliability, conventional design and intermediate load efficiencies", the preferred option includes two 6 MW stoker-fired boilers. The present worth of the capital costs for this option is given as $56 million. However, the present worth of the capital costs for two 6 MW fluidized-bed units is estimated at $48 million. No information was presented on the heat rates of each option or the comoarative advantages in fuel consumption. Considering that fluidized bed boilers tend to be more efficient than conventional boilers, it appears as if the fluidized bed option is most cost-effective. A coal-fired power plant has potential for waste - heat utilization. However, the report did not give consideration to this potential or attempt to determine the benefits which could occur. Regional Options This review does not evaluate the various regional options or the sale of Silver Lake power to Copper Valley Electric Association. It is assumed that the ioad forecasts and power supp!y options are consistent with other reports. Economic Analysis The comparison of present cost of alternatives (p. 10-9 and 10-10) are backwards. The cost of the base case (diesel) should be the numerator rather than the denominator when calculating cost/cost. The yearly present cost calculations are based on the total annual costs (table 9.2-1) which includes amortized capital costs instead of capital costs applied to the year in which it is incurred. APA procedures require the latter approach. The advantage of this approacn is especially apparent when phasing in different projects sucn as the small hydroelectric alternative. - The report included the economic analysis print-out of only one alternative. These printouts are critical to reviewing any study. The consultant should not consider that assessment or recommendations will be accepted without providing detailed support data such as economic analysis printouts. - The statement that the “rank order of alternatives is not sensitive to variation in energy demand" jis questionable. Variations in the assumptions may be greater than differences in the rank order. - The "Cordova Power Supply Interim Feasibility Assessment" has a number of jnmadequacies. To summarize aly There are numerous inconsistencies between the data in the report and its interpretation. Some of these inconsistencies are brought out in this memo. 2. The report is incomplete. Statements are made without adequate support data. 3. The report includes a number of questionable assumptions. As pointed out by the Army Corps of Engineers, the report seems biased towards making the Silver Lake option work out. 4. The report recommends virtual commitment to the Silver Lake Project without fully developing its technical, economic, or environmental . justification. To recommend that “preparation of necessary permit and license applications to be pursued in Phase II of the study” is premature and does not give the impression of an objective evaluation of alternatives. It is recommended that the APA not accept the consultants recommendation when contracting for the Chase IT study. A more comrrehensive effort is needed to meet statutory and regulatory conditions. Based on this review, it appears as if 1) Silver Lake 2) small hydroelectric sites 3) fluidized bed coal generation and 4) the diesel base case should be evaluated in greater detail. Emphasis should be placed on construction startup timing. In addition, the load forecast should not include electric space heating and more than one forecast should be used. STONE & WEBSTER ENGINEERING CORPORATION FILE COPY - poston ce: N. K. Whitcomb w/encl. N. A. Bishop w/encl. D. Hooker w/encl. S. Peterson w/encl. General Files/Boston General Files/DOC Chrono File w/encl. Clerk/JB# 14101 8.2 W. E. Shaughnessy w/encl. Mr. Eric P. Yould October 14, 1982 Executive Director Alaska Power Authority J. 0. No. 14101.2 334 W. 5th Avenue Anchorage, Alaska 99501 Attn: Mr. Eric Marchegiani Project Manager Dear Mr. Marchegiani: COMMENTS ON OMB MEMO OF AUGUST 17, 1982 INTERIM FEASIBILITY ASSESSMENT CORDOVA POWER SUPPLY Attached are cur responses to the comments raised by Mr. Matz's memorandum of August 17, 1982. We have modified our previous responses of September 10, 1982, co include our economic analysis of competitive alternatives to meet a new low-load growth projection requested by the Power Authority. We have also made other minor changes as have been requested. This information will be included in the Addendum to the Feasibility Assessment Report. ote N. K. Whitcomb Project Manager NKW/WES/ke Enclosures Load Forecast - The interim report states that "SWMCI found it improbable that conversion to residential electric space heating would occur unless the cost of energy fell to less than 6¢/kWh from its current cost of approximately 20¢/kWh" (Appendix. 2). The report also states "CEC currently charges residential customers about 10¢/kWh for depreciation operations, and administrative costs. Therefore, even if hydroelectric power was free, the electric power cost to the customers would be a minimum of 10¢/kWh" (p. 9-10). Despite the unattractive cost of electric heat, the load forecast devoted considerable effort to speculating what demand for electric space heating may occur "if future electricity is provided at a significantly lower cost" (p. 4-2). A number of scenarios for conversion to electric space heating are described, which gives the impression that it's a question of how much rather than if. Figure 9.3-9 adds to this impression by plotting how long it would take for fuel oil space heating to reach 10¢/kWh if fuel oil experienced a real escalation of 4, 6, and 8% instead of the 2.6% fuel escalation rate provided by Alaska Power Authority (APA) criteria. No rational is given for such high fuel escalation rates. Also, the report does not verify with actual data its assumptions on Cordova's annual household energy consumption for space heating. "Conservation measures previously identified and recommended in the Reconnaissance study were not considered" (p. 2-5). Nevertheless, the load forecast used to compare the total present cost of each alternative "is based on a moderate space heating scenario for Cordova" (p. 1-32). Present costs for a no space heating load forecast are also given but in the form of a sensitivity test rather than a most likely scenario. The cost of space heating by electricity is unattractive at present due to the high cost of generating electricity with diesel fuel. On this basis, we have analyzed the best generation alternatives based upon load forecasts that do not include space heating. The load forecasts are discussed under item 3. Figure A shows the present day Cordova fuel costs escalated at 2.6% in accordance with the Power Authority's FY-82 economic criteria. The cost per gallon of the fuels, both present day and projected to 2002, are as follows: BASIS FOR FIGURE A Present Day 2002 Fuel Cost per Gallon Cost per Gallon Remarks Propane Si 97 $3.29 Diesel 1.07 1.79 (Cost to CEC includes delivery) #1 Oil 1.45 2.43 (0-100 gallons) Leo) Za25) (100-200 gallons) 1.38 Zeta. (200-300 gallons) 1.29 215 (300 up gallons) #2 Oil 138 250) (0-100 gallons) 1.28 2135 (100-200 gallons) 1.24 2.07 (200-300 gallons) doiZd 2505 (300 up gallons) NOTE: All costs rounded to the nearest whole cent Propane, which has the highest per gallon price, is presently used in trailers and mobil homes in Cordova (32% of the housing) for heating and cooking. R. W. Retherford Associates projects that propane will continue to be used as follows: Propane Use in Cordova Forecasted use in 2000 1979 (actual) Low Medium High 65,250 gallons 91,000 111,000 124,000 gallons The corresponding equivalent cost of propane in 2002 based upon 2.6% escalation is approximately 19 cents per kilowatt hour. To graphically demonstrate the impact of hydroelectric energy on consumer electric costs, Figure B shows the consumer cost of electricity for the Silver Lake development based on the sale of excess energy to CVEA (Valdez and Glennallen) and the Power Authority FY 82 criteria. This figure indicates that electric costs will be at or below 19 cents per kilowatt hour and there is a potential for conversion from propane to electricity in trailers and mobil homes before the year 2002. The most economical space heating option remains heating oil. However, the actual consumer selection of a space heating option is also based upon capital cost of the furnace and other factors too difficult to predict with certainty 10 to 15 years in the future and have used load forecasts without space heating. The 4%, 6%, and 8% escalation rates for fuel shown in Figure 9.3-9 were used only to graphically show their effects. They were not used in evaluation of the alternatives. As required by the Power Authority, the FY 82 criteria fuel escalation rate of 2.6% was used. However, a review of recent diesel fuel costs as shown on Figure E indicates that the rate of escalation of diesel fuel costs in Cordova between 1979 and 1982 were far in excess of 8%. In January 1979, diesel fuel cost 48.5 cents per gallon, in October 1982, 105.2 cents per gallon, a difference of 56.7 cents per gallon in 3.8 years, corresponding to a 15 percent escalation rate. The quotation "Conservation measures previously identified and recommended in the Reconnaissance Study were not considered" (p. 2-5) is somewhat misleading. Based on Cordova's current usage, it is obvious that a significant number of conservation measures have been implemented. Unit residential usage as shown in Figures F and G are low when compared with other Alaskan communities. The high cost of electric energy has made conservation a necessity in Cordova. It will be difficult to force the Cordova residents to further conservation as their consumption is well below the state average. Should the cost of power reduce, negative conservation could take place, negating the effects of the Reconnaissance Study's recommendations for additional conservation on the demand forecast. In order to demonstrate the sensitivity to the forecast, we have evaluated the previously found most competitive generation alternatives *o supply power for no space heating demand forecast with low and high rates of growth. We have used the low forecast of the Retherford report for evaluating those generation alternatives designed for Cordova's load only and the Battelle Glennallen-Valdez nonsustainable government spending, Plan 1B, forecast combined with the Low Retherford forecast to evaluate the sale of excess Silver Lake power. The Low Retherford forecast has as a compound growth rate in peak demand of 4.4% and compound growth rate in average annual energy usage of 2.6%. The Battelle Glennallen-Valdez nonsustainable government spending, Plan 1B, forecast has a compound growth rate in peak demand of 3.7% and compound growth rate in average annual energy usage of 4.2%. We have found that the hydroelectric options continue to be the most cost competitive on a present worth basis for these low-load forecast. In addition, the Silver Lake option with sale of excess power to Glennallen-Valdez (CVEA) continues to be the most’ cost-effective alternative. Attached is Table A which presents present worth costs for the most competitive alternatives for the various load forecasts. 1. 2. 3. 4, 5. 1 CEC LOAD PROJECTIONS: CASES Diesel Base Case (w/Waste Heat Recovery)* Coal-Fired Option Small Hydro & Transmission Silver Lake & Transmission Silver Lake & Transmission Sale of Excess Power to CVEA*®* TABLE A PRESENT WORTH COSTS AND COST RATIOS BEST GENERATION ALTERNATIVES PRESENT WORTH COST ($1,000) RETHERFORD RETHERFORD LOW MEAN LEVEL 2 117,200 140,600 174,900 123,000 140,800 166,500 89,300 116,000 138, 300 103, 300 104, 600 115,100 33,400 52,500 88,400 Diesel Fuel (Oct, 1982) - $1.0695/Gallon, Fuel Escalation 2.6% per APA FY 62 Criteria Battelle Nonsustainable Government Spending Load for CVEA Benefit calculated using CVEA diesel generator fuel rate of 0.0769 gallons/kWh produced and the 1982 CVEA diesel fuel cost of $1.03/gallon (escalated at 2.6% per year). Present Worth Cost yf Diesel Base Case Diesel Base Case 7 Present Worth Cost RETHERFORD LOW 1.00/1.00 1,05/0.95 0.76/1.31 0.68/1.13 0.28/3.51 cost RaTIos 1 RETHERFORD MEAN 1.00/1.00 1,00/1.00 0.84/1.19 0.74/1.34 0.37/2.68 LEVEL 2 1.00/1.00 0.95/1.05 0.79/1.26 0.66/1.52 0.51/1.98 ENERGY COST ¢/kWh * 1982 DOLLARS PROPANE HEATING OIL #1 HEATING OIL #2 * incLUDES 70% FURNACE EFFICIENCY Figure A CORDOVA SPACE HEATING FUEL ESCALATION, APA FY82 CRITERIA, 2.6% FUEL ESCALATION A1082036 PROPANE SILVER LAKE HYDRO ENERGY COST ¢/kWh * 1982 DOLLARS HEATING OIL #1 “HEATING OIL #2 2000 *incLUDES 70% FURNACE EFFICIENCY Figure B CORDOVA CONSUMER SPACE HEATING ALTERNATIVE COSTS, SILVER LAKE — 15 MW CAPACITY — EXCESS POWER SOLD TO CVEA, RETHERFORD LOW-GROWTH CORDOVA LOAD, BATTELLE NON-SUSTAINABLE GOVT SPENDING CVEA LOAD, NO STATE FUNDING, APA FY82 CRITERIA, 2.6% FUEL ESCALATION A1082037 Al1082015 COST OF ACOUISITION OF DIESEL FUEL ( ¢/GALLON } PRESENT DAY 1979 1980 1981 "1982 oT [mam] Ts [als ]olu[o] se [ufale a] s[als[o[n] ols] r [um] alu] y[s]a[s]olnpo] s]e[m]alm] s[s [aslo] nyo! Figure E CEC DIESEL FUEL COST z <= ! Loaf w = Oo - a > oO a wi a 2 ° e a = 2 “a 2 ° oO c w = o a > a ec < wi > w oO < a w > < SOUTH CENTRAL REGION STATE AVERAGE ° VALDEZ » (PRE-SOLOMON GULCH) @ SEWARD CORDOVA REFERENCE: ALASKA ELECTRIC POWER STATISTICS 1960 THROUGH 1981 ALASKA POWER ADMINISTRATION, U.S. DEPARTMENT OF ENERGY 7th EDITION, AUGUST, 1932 10 AVERAGE COST OF POWER TO THE CONSUMER — ¢/kWh (INCLUDES STATE SUBSIDY IF APPLICABLE) Figure F AVERAGE 1981 COMMERCIAL/INDUSTRIAL POWER CONSUMPTION At082013 é = < ! [oad w = oO e nan 2 oO a ul a 2 2 ig oO, = 2 a 2 ° oO c w = So a > a c < w > w Oo < c w > < = o REFERENCE: ANCHORAGE STATE AVERAGE ALASKA ELECTRIC POWER STATISTICS 1960 THROUGH 1981 ALASKA POWER ADMINISTRATION, U.S. DEPARTMENT OF ENERGY 7th EDITION,AUGUST, 1982 10 AVERAGE COST OF POWER TO THE CONSUMER — ¢/kWh (INCLUDES STATE SUBSIDY IF APPLICABLE) Figure G AVERAGE 1981 RESIDENTIAL POWER CONSUMPTION CORDOVA A1082012 2 - The load forecast assumed that the 1MW_ load for Chugach Fisheries, which is now self-generated, would be added to " the utilities load and ‘that an additional cannery would be constructed in 1992." (Appendix, p. 8). The report also states that "the number of processing plants in Cordova is also likely to remain constant since the plants have additional capacity or have the capability to increase their capacity "and" Cordova has ample freezing and cold storage facilites to handle present and future fish production." (Appendix, p. 6). It is not clear whether the 1MW load represents current or potential demand or that an_ additional fish processing plant is needed. The load forecast assumed the Chugach Fisheries would change over from self-generation to purchased power from the Cordova Electric Cooperative (CEC) in 1982, adding about 1MW to the CEC system peak demand. Mr. D. Bechtel of CEC advised that Chugach Fisheries began purchasing power from CEC on June 30, 1982. Their peak demand to date has been 360 kW. On September 22, 1982, Mr. P. Lovett, Cordova's City Manager, indicated that a shift from canning to freezing is expected for the fishing industry. He anticipates three freezers will be added within the next five years. Presently the canning operations are fossil fuel dependent to produce steam to run the process equipment. Freezing will be electricity dependent and will increase the projected demands for CEC. In addition to the Chugach Fisheries load, the load forecast "study assumed that an additional cannery would be constructed in 1992" (Appendix p. 8). This is in keeping with the Retherford forecast assumption that “one new commercial/industrial facility would come on line in 1992 with a maximum demand of 600 kW and annual electric load of iGWh." @) It is anticipated that the freezer load would replace and exceed the load from the existing canning operations and the additional 1992 cannery. () Reconnaissance Study of Energy Requirements for Cordova, Robert W. Retherford Associates, Anchorage, Alaska, June 1981 LZ) 3 The load forecast relied heavily on an Alaskan OCS socioeconomics study for Cordova. The study assumed a mean-growth case "which is the expected growth based on the weighted average of limited petroleum exploration scenario and the growth associated with a scenario of significant discoveries and the development of an offshore terminal” (Appendix, op. 7). The mean-growth case may not _ be realistic. For instance, can one assume that there will be half of an offshore terminal? These assumptions need better description and, perhaps, a separate load forecast for each scenario. The load forecast used 1981 as a base year and the report provided the actual data for that year. (It would have been useful to also provide actual data for the past five years in order to have some feel for what trends exist.) The 1981 actual data (energy - 16,000 MWh and demand 3.8 MW) differred from the forecast data (17,500 MWh and demand 3.5 MW). Also, the report assumes that the peak demand will increase at a rate of 4.8% while Cordova Electric Cooperative forecasts an 8% growth rate. It would be useful to have a better understanding of peak demand. Perhaps some peak - shaving strategies need to be considered. The Retherford forecast used growth projections from the study "North Gulf of Alaska, Petroleum Development Scenarios, Local Socioeconomic Impacts: Alaskan OCS Socioeconomics Studies Program, Technical Report 33, October 1979." The OCS (Outer Continental Shelf) study developed three growth scenarios, including a base case. The base case assumed growth due to the fishing industries and services with no offshore oil development. The high-growth scenario assumed a significant level of petroleum discoveries and the completion of an offshore terminal that would be staffed from the Cordova area. Under the high-growth scenario, the probability of such a significant level of discovery was assumed to be 5 percent. In our opinion, it would not be prudent to design alternative power sources with such a low probability for occurance and the OCS high-growth scenario was therefore discarded as not relevant to the study. We have included copies of the Retherford low, mean and high forecast. Cc apc -_- RETHERFORD'S LOW ELECTRICAL LOAD FORECAST CITY OF CORDOVA YEAR: 1980 1985 1990 1995 2000 2002 * A. Number & Type of Consumer: 1. Residential 719 756 195 835 878 2. Small Commercial ( 50 kVA) 2yu7 1 260 273 287 301 3. Large Commercial (50 to 350 kVA) 7 8 8 9 10 4, Large Commercial ( 350 kVA) 3 3 5 4 4 5. Public Lights, etc. 2 2 B 4 y 6. Unaccounted Power 10% 10% 10% 10% 10% B. Average Consumption (kWh) Per Year Per Consumer 1. Residential 5,833 5,800 5,500 5,500 5,300 2. Small Commercial 20,615 2 22,750 25,100 27,750 30,600 3. Large Commercial 280,000 2 309,000 341,000 377,000 416,000 4, Large Commercial 1,212,000 2 1,340,000 1,477,000 1,631,000 1,800,000 5. Public Lights, etc. 9,000 9,000 9,000 9,000 9,000 6. Unaccounted Power 12% 10% 10% 10% 10% C. Total Energy (103 MWh): L607 18.5 20.2 24.8 27.8 29.2 D. Maximum Demand (MW): 3.4 3 4.1 5.0 6.6 4 8.0 8.4 Increase of 1% a year Increase of 2% a year Increase of 4% a year Addition of 500 kW load Swne Reference: Final Report: Reconnaissance Study of Energy Requirements and Alternatives for Cordova, Robert W. Retherford Associates, Anchorage, Alaska, June 1981. * Projected values based upon Retherford's assumptions. RETHERFORD'S MEAN ELECTRICAL LOAD FORECAST CITY OF CORDOVA YEAR: 1980 1985 1990 1995 2000 A. Number & Type of Consumers: 1. Residential 719 833 3 897 4 gua 991 2. Small Commercial ( 50 kVA) 247 ele 300 3) 323 348 3. Large Commercial i 10 ll 5) 17 (50 to 350 kVA) 4, Large Commercial ( 350 kVA) 3 4 4 5 5 5. Public Lighting, etc. 2 4 5 6 6 6. Unaccounted Loads (4) 12 12 10 12 10 (city, plant & losses) B. Average Consumption (kWh) Per Consumer Per Year 1. Residential 5,833 6,000 5,800 2 5, 800 6,000 2. Small Commercial 20,615 21,500 23,000 24,500 27,000 3. Large Commercial 280,000 335,000 388,000 450,000 521,000 4. Large Commercial 1,212,000 1, 368,000 1,510,000 1,520,000 1,680,000 5. Public Lighting, etc. 9,000 9,000 9,000 9,000 9,000 C. Total Energy Consumption (103 MWh): 16.7 22.0 24.7 30.1 35.9 D. Maximum Demand (MW): 3.4 2 5.0 5.8 7.4 8.6 Notes: rate rate rate rate A growth A growth A growth A growth SFwnre Reference: Final Report: of 3% is assumed during this period. of 2% is assumed during this period. Additional Data: Addition 1,000 kW, 1.6 GWh load of Chugach oO of 1.5% is assumed during this period. ° of 1% is assumed during this period. ooooo$o Fisheries to CEC in 1983. Addition of a 600 kW, 1 GWh future customer in 1992. 2002 * 38.3 9.2 Increase in transmission network in 1983. Decrease due to system improvements in 1986. Expansion of transmission network in 1983. Transmission line improvements in 1996. Drop due to rising cost in 1986. Reconnaissance Study of Energy Requirements and Alternatives for Cordova, Robert W. Retherford Associates, Anchorage, Alaska, June 1981. * Projected values based upon Retherford's assumptions. OT RETHERFORD'S HIGH ELECTRICAL LOAD FORECAST CITY OF CORDOVA YEAR: 1980 A. Number & Type of Consumer: 1. Residential ng i 2. Small Commercial ( 50 kVA) 247 1 3. Large Commercial (50 to 350 kVA) 7 4. Large Commercial ( 350 kVA) 3 5. Public Lights, etc. 2 6. Unaccounted Power 10% B. Average Consumption (kWh) Per Year Per Consumer 1. Residential 5,833 2 2. Small Commercial 20,615 2 3. Large Commercial 280,000 2 4. Large Commercial 1,212,000 2 5. Public Lights, etc. 9,000 6. Unaccounted Power 12% C. Total Energy (103 MWh): 16.7 D. Maximum Demand (MW): 3.4 3 1 3% increase every year. 2 4% increase in consumption. 3 6% increase + large loads (1 MW in 1983 for Chugach Fisheries & 350 kW per customer thereafter). Reference: * Projected values based upon Retherford's assumptions. Final Report: Reconnaissance Study of Energy Requirements and Alternatives for Cordova, 1985 834 286 10 10% 7,100 25,000 340, 600 1,475,000 9,000 10% 26.3 5.7 1990 966 273 15 10% 8,600 30,500 415,000 1,794,000 9,000 10% 39.0 8.3 1,120 332 18 10% 10,500 37,100 504, 000 2,183,000 9,000 10% 58.2 11.8 Robert W. Retherford Associates, Anchorage, Alaska, June 1981. 2000 1,298 385 20 10 10 10% 12,750 45,000 614,000 2,656,000 9,000 10% 80.0 16.5 2002 * 90.1 18.7 aw @ w& The following is an encapsulation of the Retherford energy requirements scenario assumptions for Cordova. Low-growth scenario assumptions (stated on page 7 of the Electrical Energy Forecast - Cordova Alaska) ° Employment will grow at an annual rate of about 1.5 percent in the economic sectors of trade services and fishing. The trade and service sectors will increase by about 4.0 percent per year as tourism and recreation opportunities increase. Manufacturing employment, primarily processing, will increase by 1.5 percent per year. The growth will keep pace with forecasted increases in fish harvests. Surface transportation is assumed to increase by only 2 percent per year. This employment will result from increases in tourism and recreation. Government employment will grow at a rate of only 1 percent per year. Secondary employment estimates are based on an employment multiplier of 1.47. This low multiplier is reasonable in view of the convenience to purchase goods and services in Anchorage. As the trade and commercial sectors of Cordova's economy grow, a higher multiplier can be expected as discussed in the OCS Study page 61. Population estimates are based cn a population employment ratio of 2.0, the 1978 ratio. This ratio resulted in a forecasted population growth of 1,320 from 1981 to the year 2000 for the Cordova area. The low-growth scenario is used as the basis for change in the number of electric customers and the use per customer. el ° No OCS leasing. ° Half of the new growth for Cordova would come from new developments and improvements in the fish processing industry. ° Half would come through development of the local service sector. Mean-growth scenacio assumptions ° Same as above, except expected growth is based on a weighted average of limited petroleum exploration and growth associated with staged development of offshore facilities and construction and operations of an offshore’ terminal. Retherford and the OCS study indicate that Cordova would provide family housing to support OCS work. Population Percentage Low Median Diff. of Low 1982 2,488 2,499 1 0.4% 1985 201s 2059 26 1.0% 1990 2,850 3,338 488 17.1% 1995 3,154 3,695 541 17.2% 2000 Ss52L 4,073 552 15.7% Assuming that each OCS worker has a family of three (below the national average), and the OCS and Retherford forecasted population increases. OCS Pop. OCS Workers Increase (based on 3 Member Familv) 1982 a 4 1985 26 9 1990 488 163 1995 541 181 2000 552, 184 This level of OCS effort is relatively small and would relate to a very limited OCS work effort. The Retherford and OCS weighted average approach provides reasonable labor values. 12 The general approach for the Electrical Energy Forecast for Cordova, Alaska was to review the existing energy and peak loed studies for Cordova for reasonableness to ensure that any unique situations are identified and appropriately considered. Interviews and discussions were held to identify the current conditions as of November 1981 and likely possible changes in energy requirements and peak demands. Based on the interviews and information from source documents, the existing studies of energy consumption and peak demands were modified as deemed appropriate to reflect the information obtained. Further, we reviewed the actual annual and maximum demand and annual energy generation for the Cordova Electric Cooperative (CEC) as furnished by Mr. D. Bechtel:. Peak Demand Annual Energy Year kW MWh 1977 2,750 135754 1978 3,150 15,060 1979 3,500 16,494 1980 3,750 16) Lo 1981 37150 16,859 1982 4,000 Not Available Peak demand has grown from 1977 to 1982 at a 6.4 % growth rate and annual energy from 1977 to 1981 has grown at a 4.2% growth rate. Briefly, actual past experience is the basis for CEC's forecasted 8% growth rate. Retherford's high load forecast which projects a 7.7% energy growth and a 7.6 % maximum demand growth would substantiate CEC's 8% forecast growth rate. However, to base the design of alternative power sources on a forecast having a 5% probability of occurance is not prudent. We have reviewed Retherford's assumtions and approach for the low and mean forecasts for Cordova's Power Requirements, and as discussed, find them to be realisitc. We cannot substantiate CEC's continued growth at 8% unless there are significant oil discoveries, mineral discoveries, or outside influences which are presently unforeseen and have a low probability of occurance. Table B showing the Forecasts of Cordova's Power Requirements is attached. To avoid utilizing the high Retherford forecast, we have established an intermediate load level 2 forecast. Level 2 is based upon a 5.3% energy growth and a 6.2% maximum demand growth, less than Cordova's 13 past demand growth of 6.4% between 1977 and 1981. Level 2 is used solely as a means to demonstrate sensitivity for the design of alternative power sources to higher levels of forecasted demand. Peak-shaving strategies have been discussed with Mr. D. Becntel of CEC. Cordova's load is summer peaking due to fish canning, even with the predicted change from canning to freezing, this is not likely to change. Disruptions to this industry caused by load shedding is simply not an acceptable alternative. 14 TABLE B FORECAST OF CORDOVA POWER REQUIREMENTS Low Retherford (2.7% Growth) Mean Retherford - Level 0 (3.8% Growth) Level 2 (5.3% Growth) High Retherford (7.7% Growth) Low Retherford (4.3% Growth) Mean Retherford - Level 0 (4.8% Growth) Level 2 (6.2% Growth) High Retherford (7.6% Growth) Total Energy (103 MWh) 1992 1997 23.0 26.1 27.7 31.8 34.1 41.1 46.7 66.9 Maximum Demand (MW) 1987 17.3 19.7 18.2 22.3 18.2 24.4 20.5 31.4 1982 1987 3.6 4.4 3.6 5.3 3.6 523 4.3 6.7 1992 1997 5.6 7.2 6.8 7.9 7.7 9-7 9.7 13.7 2002 29.2 38.3 50.9 90.1 2002 8.4 9.2 12.0 18.7 Note: High Retherford forecast based upon a 5% probability of occurance which is relatively remote and therefore was not used. oe The diesel generation alternative used for the present cost analysis included 15 MW of installed capacity. Cordova's peak demand for the year 2002 is expected to be 9.2 MW without electric space heating and 12.0 MW with moderate space heating. Given the unlikely occurence of electric space heating in Cordova, it is not reasonable to estimate the costs of diesel generation based on meeting a moderate space heating load. The installed diesel generation capacity was selected to provide Cordova a reliable source of power. In designing electrical systems with reciprocating engines, installation of spare units is a necessity to ensure system reliability. The installed capacity allows for (1) the largest generating unit to be shut down for maintenance and (2) the next largest unit to experience a failure. This would allow CEC to still have sufficient capacity to supply peak electrical load and would eliminate the requirement for load shedding. This method to determine diesel generation capacity is currently used by the Cordova Electric Cooperative and other Alaskan utilities in remote areas where manpower and spare parts are limited. The diesel generation base case for the Level 2 load had 15 MW of installed capacity in the year 2002. However, the diesel base case for the Retherford mean forecast (Level 0) had only 12 MW of installed capacity in 2002 and only 11 MW of installed capacity for the Retherford low-growth load. To put the cost of providing this increased reliability in perspective, the estimated cost of one 2,500 kW diesel generator set installed with auxiliaries is $965,000. The total accumulated present worth of costs through the life of alternative DO1l (Retherford mean load) with no space heating is $141,900,000. Therefore, the increment in cost for one spare 2,500 kW diesel generator unit is less than 1% of the present worth of evaluated costs and certainly a small price to pay for reliable power. 15 ee Fuel costs are presented for diesel generation but not the heat rate. This information should be included. The heat rate used for the diesel generator sets evaluated in the interim report was assumed constant at 10,900 Btu per kWh generated. This heat rate was derived from operating reports of the existing Eyak diesel generating plant and performance specifications for differing sizes and manufacturers of diesel generator sets. 16 6 - The report concludes that the benefits of waste heat utilization from diesel generators is marginal even though there are nearby public buildings. No details are presented to support this conclusion. Is the waste heat distribution system optimized for cost-effectiveness or does it include buildings which are too distant from the powerhouse to be economically feasible? The Cordova public buildings that can potentially be supplied by waste heat are listed in the diesel waste heat section (page 5-9) of the interim report. These buildings are all located between 2,400 and 4,800 ft from the existing Eyak diesel generating plant. There are no evident benefits to supplying waste heat to any combination of the buildings other than those listed in the interim report. SWEC prepared detailed calculations of diesel waste heat availability, the distribution system design, and capital cost and maintenance expenditures for the waste heat distribution system. These calculations were recently reviewed by the Alaska Power Authority. The Power Authority requested SWEC to use economic lifetimes for the waste heat equipment from the FY83 guidelines (20 year life) instead of the FY82 guidelines (10 year life). The Power Authority comments were incorporated into the analysis and the life-cycle present worth costs were re-evaluated based upon the CEC diesel fuel cost of $1.0695 per gallon and the changes discussed above, resulting in slightly more attractive values for the waste heat systems. The revised present worth costs are as follows: Present Worth Cost, $1000 ee Retherford Retherford Mean Level 2 Low-Growth Load Load (Level 0) Load Diesel Generation 117,800 141,900 176,200 Diesel Generation + 117,200 140,600 174,900 Waste Heat Recovery 7, As discussed above, the present worth values for the diesel generation alternatives are slightly improved with the addition of waste heat recovery. Therefore, diesel generation with waste heat recovery will be carried forward as the base case. However, it should be noted that the present worth values for the new base case are higher than for other generation alternatives. 18 7 - Further studies should use the most recent price for fuel oil. If the recent reductions in fuel oil prices are not accounted for, the fuei escalation rate may be excessive. The fuel oil prices were current at the time that the study was performed. In April of 1982, Mr. W. D. Bechtel, General Manager, Cordova Electric Cooperative (CEC), reviewed a SWEC summary progress report and provided comments on diesel transportation charges. During subsequent phone conversations, agreement was reached between SWEC and Mr. Bechtel regarding the current, delivered diesel cost per gallon experienced by CEC. These diesel costs were used in the final report (i.e. $1.11/gallon delivered). To confirm the magnitude of the recent fuel oil price change, we contacted Mr. D. Bechtel on August 31, 1982. He advised that CEC presently buys diesel at $1.052 per gallon at the dock in Cordova and pays $0.0175 per gallon transport to the plant (i.e. $1.0695/gallon). It should be noted that in August 1982 diesel prices were depressed by an oversupply of refined petroleum products on the U.S. market. Mr. Bechtel advised that the price used as the basis for the interim report should not be changed as the fuel price fell early in the year but is expected to begin rising again. Figure E illustrates the CEC diesel fuel cost on a monthly basis since 1979. The diesel escalation rate used in the study (2.6 percent per year) was specified in the FY 1982 Power Authority economic guidelines. This rate of increase is intended to reflect the average annual rate expected over the complete analysis period (1982 through 2002) and not short-term variations such as those caused by the current economic recession and oversupply of oil. _ In order to illustrate the effect of varying assumptions regarding the 1982 diesel price, the diesel cases were re-evaluated using $1.0695/gallon in 1982. The following results were obtained for the Cordova load projections: 19 Present Worth Cost ($1000) Retherford Retherford Level 2 Low-Growth Mean Growth Growth Diesel Generation $1.11/gallon in 1982 N/A 145 ,900 181,400 $1.0695/gallon in 1982 117,800 141,900 176,200 Thus, although the present worth costs are lower with the $1.0695/gallon diesel price, they are still considerably higher than for other generation alternatives. 20 Silver Lake 8 - The report states that "the hydroelectric development proposed for Silver Lake is based on a 120 foot high concrete dam located at the lake mouth... At this time no fatal flaws have been identified which would prevent project development". However, the report also states that "Duck River, which drains Silver Lake, is one of the more productive salmon streams in the area. Assuming that the powerhouse is placed above the upper extent of spawning, a run-of-the-river hydroelectric facility should have minimal environmental impact. However, @ project involving a major dam_ could seriously affect the fisheries resource." (all quotes from p. 1-17 and 1-18). It appears as if the Silver Lake Project may have "fatal environmental flaws." Also, possible impacts on fisheries during construction and reservoir filling are not adequately addressed. The report is as assessment and is not intended to be a final feasibility report. The interim report describes the Silver Lake resource and indicate that no fatal flaws have been identified for the Silver Lake development. By definition a fatal flaw is a defect or an unmitigatable issue which would prevent development of a site. If a technical environmental problem was identified it was noted and discussed in the interim report to allow for careful field study and further investigation. These field studies were initiated in April 1982 and have been ongoing. These field investigations have shown that there are no environmental fatal flaws at Silver Lake. Previous concerns have each been studied and the environmental issues are mitigatable. During construction of the Silver Lake project, it is proposed that there will be no change in the natural lake outflow. Upon completion of the dam and auxilliary structures reservoir filling would be initiated and 21 throughout the filling period a minimum outflow of 100 cfs would be maintained (the natural low base outflow is 25 to 30 cfs). The reservoir filling will be studied in more detail during the next phase of the study. Attached is an October 8, 1982 memo from Mr. Ron Dagon, DOWL to Mr. N. K. Whitcomb, SWEC. Also attached is a memo from Mr. B. Burke, DOWL geologist to Mr. Ron Dagon, DOWL. 22 Ipl0}2 FROM: October 8, 1982 W.O. 2050024 Norm Whitcomb - Stone & Webster Ron Dagon \ a SUBJECT: Cordova Power - Silver Lake Alternative; Status of Field Investigations (environmental/geotechnical) As you have requested, the following is being provided to confirm at this point in time the lack of a "fatal Taw" for the Silver Lake site. The major elements of our 1982 field season are nearly complete and our field camp located at the lagoon on lower Duck River is being closed out this date. How- ever, our hydrological stations will be maintained throughout the coming winter season and routine visits to the sites are scheduled that will gather hydrologi- cal data, maintain the "ice test" facility, and make appropriate biological observations. Additional instream work relative to fisheries will also be con- ducted during a 2-3 day site visit in early November and the "ice test" facility installation will be accom- plished during to or prior to this period. The following salient points can be provided at this time relative to a preliminary analysis of the work to date: ° there are no terrestrial ecological constraints to the proposed development. 23 Mr. Nor October Page 2 ° ° m Whitcomb 8, 1982 there are no archaeological or cultural resource con- straints to the proposed development (see attached 9/20/82 letter). preliminary hydrological data tends to confirm the historical USGS hydrograph as well as the conserva- tive water forecast used in the preliminary analysis by SWEC. while the lower Duck River - lagoon system is a major spawning and rearing area for both pink and chum salmon, it appears that the proposed facility and its subsequent operation provides an opportunity for enhancement of the fisheries assuming regulated release of water. it also appears that any impacts related to the con- struction and operation of the proposed facility could be mitigated at relatively low cost particular- ly with reference to the lagoon. all socioeconomic impacts identified to date are positive. no rare or endangered species have been identified in the project area. reconnaissance level underwater investigation of the construction dock site revealed no invertebrate popu- lation that would impose any constraint on the pro- posed development. 24 Mr. “Norm Whitcomb October 8, 1982 Page 3 ° no resource agency to date has raised any major issue (objection) relative to the proposed project. 4. Attached is a summary of the current status of the ageologic/geotechnical work at the site provided by Bob Burk. 25 October 10, 1982 W.0. #050024 TO} Ron Dagon FROM: Rob Burk SUBJECT: Silver Lake Geology/Geotechnical Work Geologic and geotechnical fieldwork at the feasibility study level was performed in the Silver Lake area during August and September 1982. These studies were intended to provide information on the geologic and geotechnical constraints to development of a proposed iydroelectric power facility at this site. Regional geology;-detailed geology, at the dam- site, along the road and penstock routes, and at the power- house site; geologic hazards; and jon site) /availability | of materials have all been evaluated. Although final data reduction and analysis is not complete, no major constraints to development have been identified. Four drill holes have confirmed surface observations of nighly competent rock at the damsite. Pressure tests of these holes showed negligible losses. No faults are known to cross the damsite and faults in the general area are probably inactive. A side channel near the proposed damsite has been investi- gated by hand probes, one drill hole and seismic refrac- tion. Preliminary results from these methods show that bed- rock is present at no greater than 10 feet below ground surface. 26 Mr. Ron Dagon October 10, 1982 Page 2 Avalanche tracks, steep slopes and local areas of peat are the principal factors which will influence the siting of the penstock and powerhouse. Careful attention to location and design should allow construction without extraordinary costs. A large materials site has been located at the southeast end of Silver Lake. This gravel has low percentages of some of the sizes needed to make concrete. However, the quantity of the deposit as a whole is sufficient to allow screening and retrieval of the size fractions necessary for an appropriate mix design. Rock quarry sites have also been identified, should crushing of bedrock be necessary. The proposed dock site would be founded on bedrock and no unusual geotechnical problems are expected. Portions of the road leading to the dock site will have to be constructed across areas with up to 9 feet of peat. Careful attention to design and location will be especially important over those portions of the route and will help to minimize costs. 27 7 amas | ~ Sys SILA . Not om aN pihtaetroret lee Soca pteee nee y Eee ty "D169 ING. Renered jas PLL AIECS, SLASKA C9707 DIONE: (207) 452-7689 September 20, 1982 Mr. Ron Dagon, Project Manager DOWL Engineers 4040 B Street Anchorage, Alaska 99503 Reference: Silver Lake Hydroelectric Project Cultural Resources Investigation Dear Mr. Dagon: We are pleased to inform you that the field work portion of the preliminary cultural resources assessment of the Silver Lake hydroelectric project has been completed. Analysis and report write up will be conducted over the next few weeks as per our agreement; the final report will be delivered on or about November 1, 1982. In the meantime we wish to give some preliminary indications of the results of the field investigations. The archeological potential of the proposed powerline right-of-way between Cordova and Valdez is variable. That portion at high elevations has limited potential for evidence of past human activity, and aerial survey by helicopter should suffice to verify the absence of significant cultural remains there. Near the northern terminus of the route to Valdez, some on-the-ground survey should be conducted, prior to construction in that area, where the right-of- way ties into the existing power grid. At the southern end of the route to Cordova, the right-of-way crosses the heads of several bays and over streams supporting salmon runs. Because of the high potential for aboriginal use of such areas, both in historic and prenistoric times, several places along this portion of the route will require intensive on-the-ground inspection prior to ground altering activities. In Orca Bay, where the corridor travels down Humpback Creek to intersect the coastline, the powerline crosses directly over an historic site which contains remains of at least two structures. Other debris is scattered nearby. From the air one ruin appeared to contain a large flywheel assembly, suggesting that the site has some functional identity beyond that of a homesteader's cabin. At least two cultural sites were discovered in the near vicinity of the dam and reservoir project area. The first is a large stack of cut timbers on the small peninsula in Galena Bay, which is the proposed dock site. The logs were probably rafted in on a high tide, perhaps as much as sixty or seventy years ago. Preliminary speculation by local informants as to the functional identity of these logs includes: (1) floaters for a floating fish trap, stored on the shore by a local cannery, and (2) timbers intended for the development of the Vesuvius Mine, operated by the Galena Bay Mining Company (the dock site for the historic mine is within % mile to the west). * Fis ta STS TG SSSR RSS CES Sees Wa eee ee SS TL SINS 5 SEE Sto Nesom ante ip tals etre sects saute area tat mor ttUGe Silver Lake Archeology September 20, 1982 page 2. The second cultural site consists of three depressions located in a group on a stabilized portion of the Duck River delta, just south of the stream's mouth at the lagoon. Charocal was discovered below the ground surface in a test excavation near one of the depressions. Charcoal suggests a cultural origin for the depressions, and they may reflect a native fish camp occupied at some time in the past. An alternate interpretation is that the pits are the result of early prospecting activity. A third locality at the northeast margin of the lagoon may contain a cultural site also, although test excavation was inconclusive. A discrete area approximately eight by six feet was found to contain considerable charcoal and carbonaceous soil; but no depressions or other artifacts were discovered. Local informants mentioned a historic trail from the lagoon to Silver Lake. This trail apparently followed the south side of the Duck River. Additional Ground survey may be required if it is decided that this trail should be further documented. The potential for archeology along the margins of Silver Lake is limited. However, local scurces pointed out the location of a storage area where a small boat/raft used to be stored at the southwest part of the shoreline. In concluding these remarks, I have been requested by Chuck Mobley and Risa Carlson to extend their thanks for the courtesy and help extended to them by DOWL personnel. To theirs I add my own thanks. Kindest regards, Alaska Heritage Research Group, Inc. q Vb doar Glenn 8acon Vice President GB:CM:me ai i 1 i ” 4 i ii is % ; i 1 1 i The Comparison of Alternatives section of the report evaluates Silver Lake (and all other aiternatives) for several technical and environmental factors. The evaluation assigns either a preferred, acceptable, not acceptable or unknown rating. Despite the possible environmental impacts and lack of geotechnical data, the Silver Lake Project is given a rating of preferred or acceptable for all factors. It_seems that an unknown rating would be more appropriate in many cases. Subjective rankings at the assessment level are commonly used as a means for qualitative comparison. The word "unknown" would be appropriate only if no assessment or information was available. To date our ongoing field studies still support the qualitative comparisons presented in the interim report. There appears to be a misunderstanding in regards to Silver Lake's environmental rating. To clarify this we have prepared the following chart to clarify the key presented at the bottom of Table 10.2-1, Environmental Factors. HO2 - Silver Lake Community & Agency Preferences A - Acceptable - moderate impact Impact on Community Infrastructure P - Preferred Timing in Relation to Other limited impact Capital Projects P - Preferred - limited impact Air Quality P - Preferred - limited impact Water Quality P - Preferred - limited impact Fish and Wildlife Habitat A - Acceptable - moderate impact Land Use Impact and Ownership A - Acceptable - moderate impact Terrestrial Impacts A - Acceptable - moderate impact Recreational Value A - Acceptable - moderate impact Visual Impact A - Acceptable - moderate impact The environmental ratings are not simply P - preferred, but P - preferred - limited impact, to suggest further study required. 29 10 - A letter from the Alaska District Co that "Sey t ict estimate for the Silver Lake alternativ are i "Based on similar size projects in remote areas, we believe een eee ene that the $120,000 operating and maintenance cost is too low. When compared with similar size projects in remote areas with severe climate and topographic conditions, believe that the modification and site preparation costs are unrealistically low, the $5.2 million cost for the dam and spiliway is unrealistically low. The cost for lands and rights-of-way should be included as an economic cost. Similarly, the cost of an access road should be included." " The Corps further states that the report appears positively biased towards development of the Silver Lake site." It appears as if the cost of the Silver Lake Project may be somewhat higher than that provided by the report. If so, it is premature to strongly emphasize Silver Lake in future studies and exclude similiar emphasis on other alternatives, as recommended by the consultant. The letter rom the Alaska District Corps of Engineers (COE) discussed above was not based upon the Interim report (June 1982)but rather on the March 22, 1982, Summary Progress Report. Upon receipt of the Alaska District Corps of Engineers' letter, dated May 7, 1982, we discussed the comments with Mr. Carl Borash, COE. To clarify the basis for the Corps of Engineers' comments on Silver Lake, Mr. Harlan Moore, Chief, Engineering Division, COE, Anchorage, provided us copies of the Bradley Lake Hydroelectric Project Design Memorandum No. 2, dated February i982. We received the Design Memorandum on June 8, 1982. To the extent possible due to timing, COE comments were incorporated in the interim report. The following is a discussion of the COE comments on the Summary Progress Report. 30 The 2 to 6 cents per kWh appears unrealistically low (page 8, paragraph 3 and 4) The backup information is included in Volume 2 of the interim report, “Electrical Energy Forecast - Cordova, Alaska. Each scenario is discussed in detail. Also, see comments and figures under item 1. The annual power consumption of 50,900 MW hours with a peak of 12 MW appears high. age 9, paragraph 4.3 During the years 1977 to date, Cordova has experienced the following growth in required generation: Year Energy (MWh) Peak Load (kW) 1977 13,754 25750. 1978 15,060 3,150 1979 16,494 37500) 1980 16,151 35750 1981 16,859 35750 1982 Not available 4,000 During the period 1977 to 1981, Cordova's energy requirements have increased an average of approximately 4.2 percent, and peak load has increased 6.4 percent. The year 2002 forecasted annual power consumption of 50,900 MWh with a peak load of 12 MW corresponds to increases of 5.3 percent and 6.2 percent, respectively. When comparing the predicted growth to histcrical records, the predicted values appear reasonable. The 1982 peak occurred in August with the city of Cordova peaking at 4 MW which is higher than predicted. The energy consumption for 1982 will not be available until January 1983, but Mr. D. Bechtel indicates that consumption will also exceed the predicted 17,500 MWh. Other forecasts have been prepared and used to evaluate the various alternatives. The lowest forecast has an annual power consumption of 29,200 MWh with a peak demand of 8.4 MWh in the a year 2002. This forecast uses an average increase in power consumption of 2.7% and in peak demand of 4.3% both of which are well below the historical growth. An intermediate growth forecast between the low and the 12 MW as well as a high growth forecast were made and used in evaluation of the alternatives. We suggest that the diesel backup capability should be 9.2 MW rather than 7.6 MW _as_ facilities required to meet additional demand after 1996 should not depend on emergency standby equipment (page 9, paragraph 4.3) The 7,625 kW would meet Cordova's peak emergency requirements through 1996 (7,600 kW). The peak requirements occur during July or August during the canning season and are reduced throughout the rest of the year. We believe that peak requirements in excess of 7.6 MW which may occur after 1996 could be met by the use of emergency generators now available to principal Cordova industrial and municipal energy users. This would avoid additional cost to consumers for standby equipment. This matter will be discussed more fully with the CEC in Phase II. The text is not clear _as to whether any fuel cost escalation is considered (page 13, Paragraph 5.7) The Power Authority's Economic Criteria required a fuel escalation rate of 2.6 percent per year. Qur__and_ other agency studies have documented geologic, topographic, hydrologic conditions along Power Creek. The report makes it clear that little reliable background data exists for the considered Siiver Lake site. Yet, the report draws subjective conclusions favoring the more remote Silver Lake alternative. We have found Silver Lake to be an economically attractive alternative worth recommendation for additional study. In April 1982 we initiated field studies to document geologic, topographic, hydrologic conditions at the Silver Lake site. The "subjective conclusions" are economically based. Our preliminary economic sensitivity analysis indicates that the price of alternative fuels are not competitive with Silver Lake. 32 mh The 1982 field program has collected geologic, topographic and hydroiogic data on the Silver Lake site. All the field data collected has indicated site conditions are very favorable for development. The proposed Power Creek tunnel or penstock would be 4,000 to 5,000 feet long rather than 5 to 6,000 feet long (page 37, paragraph 7.2.1.5) We have made the correction in the interim report. No authoritative studies have been made that would support the conclusion that a sluiceway is infeasible (page 38, paragraph Dmidneics) We agree and have changed the wording of the sentence in the summary report: "Construction of a sedimentation sluiceway at the dam would not be feasible because of the resulting high concentration of sediment released over a short period of time may affect downstream spawning beds and fish resources." To the following for the interim report: "The construction of a sedimentation sluiceway at the dam may not be feasible because the resulting high concentration of sediment released over a short period of time may affect downstream spawning beds and other fish resources." However, we are concerned about the sudden increase of silt on the downstream river ecosystem and believe that sluicing could present a severe environmental impact. The development of the Silver Lake alternative is based on very limited hydrologic and geologic data. Yet the cost contingency factor for this alternative reflects a higher degree of confidence than for Allison Lake when more data is available. (page 39, paragraph 7.3.1.3 to 7.3.1.4) 33 We will adjust the Allison Lake unit costs to reflect present day costs and a 30 percent contingency. The contingency was not intended to reflect a higher degree of confidence in Silver Lake but rather uncertainties regarding underground construction at Allison versus aboveground construction at Silver Lake. The Silver Lake analysis assumes that foundation conditions at the damsite are adequate and an on-site aggregate source exists. If either or both assumptions are wrong, significant changes in project costs would result. (page 41, paragraph 7.3.3.1) We agree, and as discussed herein we have performed detailed on-site geological studies. See comments under item 8. The rock at Silver Lake is superior for the purposes of dam construction when compared with other areas of the region where Valdez Group rocks are exposed. To provide preliminary confirmation of the characteristics of the abutment rock at the dam site, three 50 to 75 ft long bore holes were drilled in the approximate orientation shown on Figure 7.3-2. NX core was obtained from the bore holes. The drill holes confirm there is little or no depth of overburden at the dam site. Open joints or fractures occur only near the rock surface and the depth of excavation required to reach a suitable dam foundation will be minimal. At depth the rock cores are sound with the joints and fractures healed and filled with quartzite. The holes were water tested and found to have very low permability. The rock at the dam site is sound and water tight and will make an excellent foundation for the dam. We question whether a 15 MW capacity can be sustained. Based on similar size projects in remote areas, we believe that the $120,000 0 & M Cost is too low. (page 42, paragraph 7.3.5) We have proposed a 9 to 15 MW plant capacity in the interim report to provide a cost estimate range. We believe that an increased capacity may be warranted in combined operation with Solomon Guich. This will be studied in detail in Phase II. 34 Based on recent data received from the Power Authority, we have revised the 0 & M costs for all the hydroelectric alternatives. The revised 0 & M costs are used in the economic evaluations discussed under other comments. The O & M costs for the hydroplants and their respective transmission lines are contained in the following tables. The 20% emergency contingency is the same percentage used by the Power Authority, and it is our understanding that about 75% of that amount is to build up funds to cover the cost of the major maintenance activities which occur at 5 to 10 year intervals instead of annually. Hydroelectric Plant 0 & M Costs Annual Item Estimated Cost A. Plant operators at $66,000 to provide daily coverage and limited daily maintenance $132,000 Br Plant production supervisor assign 25% of time at $72,600/yr 18,105 G. APA operations staff time at 100 hrs/yr 4,000 D. Consulting services contracts for operation and maintenance 20,000 E.. Department of energy fees 2,500 F. CEC administration overhead costs 17,400 G. APA administrative overhead costs 15,000 He Minor operation contracts 20,000 is Annual replacement costs 17,500 Je Miscellaneous services and supplies 15,600 Subtotal 3415350 20% Emergency contingency 66,270 TOTAL $397,620 Use $400 ,000 35 Hydroelectric Project Transmission Line O & M Costs Annual Item Estimated Cost A. Substation periodic inspection and testing $31,600 Bi Transmission line inspection and maintenance including SCADA Comm. line rental charge 52,000 Gy Maintenance of SCADA System 7,500 De Annual relay and meter inspection, testing, and calibration 7,600 E. Right-of-way clearing, inspection and maintenance 42,500 Rs Transmission line loss insurance 10,000 Ge CEC administrative overhead costs 12,000 H. APA operations staff time at 200 hours 8,400 les APA administrative overhead costs 8,000 J APA accounting costs 2,000 K Annual replacement costs 7,093 i Miscellaneous supplies and services 4,000 Subtotal $202,693 20% Emergency contingency 40,539 TOTAL $243, 23 Use $250,000 Annual O & M cost for Silver Lake Transmission Line was estimated at $330,000. The increase over the other project transmission lines is to account for the longer line required for Silver Lake. When compared with similar size projects in remote areas with several climatic and topographic conditions. we believe that: The mobilization and site preparation costs are unrealistically low, the $5.2 million cost for the dam and spillway is unrealisticallv low when compared _to the similar sized Bradley Lake dam and spillway cost of around $27 million. (Table 7.3.2) The mobilization and site preparation costs estimated as $1.1 million, will be reviewed during the Phase II of the feasibility study. Certainly the Silver Lake development cannot be compared on the same basis as the 135 MW Bradley Lake Project. The proposed concrete gravity dam and spiilway for Silver Lake are of conventional placed, roller compacted concrete (50,000 cubic yards) which is much less than the quantity of concrete required for the Bradley Lake dam (73,500 cubic yards). 36 The Bradley Lake dam is proposed as conventional mass concrete priced at $21C per yard while we have priced the conventional placed, roller compacted concrete at $60 per cubic yard. The COE is presently constructing a roller compacted concrete dam at Willow Creek Hepner, Oregon, for a unit price under $24 per yard. At $60 per cubic yard the 50,000 cu yd gravity dam at Silver Lake would cost about $3,000,000. We have looked at the possibility of placing an arch dam which would have 10,000 cu yds of concrete at Silver Lake. Based on the cost of concrete for the Swan Lake arch dam of $350 per cubic yard, an arch dam at Silver Lake would be $3,500,000 or very close in cost to the gravity dam included in the estimate. However, the selection of dam type will require a detail analysis of all alternatives which will be performed during the next phase of the work. The costs for lands and rights-of-way should be included as an economic cost. Similarly, the cost of an access road should be included. The stated power plant costs also appear low. (Table 7.9.2) Land acquisition costs for the hydroelectric alternatives have been included in the revised cost estimates and economic evaluations included herein. The estimated cost of land has been based on the "Chugach Regional Study Analysis of the Federal Alternative and Comparison with the No Forest and Status Quo Alternatives," Institute of Social and Economic Research, University of Alaska, 1981. The estimated land aquisition costs for each project are as follows: Estimated Cost Project Estimated Cost w/30% Contingency Crater Lake $160,000 $208 ,000 Sheep River Lakes 62,000 80,600 Lake 1488 58,500 76,000 Silver Lake 552,900 718,800 37 The cost of the access road is included in the estimate. The powerplant costs vary from 39 million at 9 MW to 58 million at 15 MW. Standard horizontal axis split case Francis turbines are proposed with floor mounted generators. The powerhouse is a simple structure as shown in section 7.0 of the Interim Report. We will review the estimates once the powerhouse is sited during Phase II. We cannot understand the rationale used to nearly double the Allison Lake project cost estimate when much more data _ is available than is for the Silver Lake alternative. This increase should be clearly documented. (page 44, paragraph 7.4.3) See the attached estimate. We were requested to review the COE estimate for Allison Lake by the Power Authority. The tunnel concrete lining was omitted and we believe tunneling and penstock costs were underestimated. 38 Cost Account Number ol ou ou.t 04.2 MOB & PREP WORK LANDS & DAMAGES Government Admin Cost Powerhouse & Trans- mission Facilities (Private Lands) TOTAL - LAND & DAMAGES INTAKE WORKS & PENSTOCK LAKE TAP & ROCK TRAP Excavation Concrete Reinforcement Trashrack Rock Bolts, Lake Tap "x7! TOTAL - LAKE TAP & ROCK TRAP GATE CONTROL ROOM Slide Gate, heavy duty Slide Gate, Std. type Access Hatch Ladder (w/cage) 200' Hydraulic Unit & Elevator, 3,0004 cap Elevator, 1,000f cap Vent, 8" 0 pipe Hoist 10-ton cap. Excavation, Rock Concrete Lining Reinforcement Rock Bolts, 1"0 x 7! Elec Equipment/Operators Dewatering/Grout TOTAL = GATE CONTROL ROOM * Unit Price Adjustment *# Omission TABLE D-4 DETAILED COST ESTIMATE VALDEZ HYDROCLECTRIC PROJECT COE ALTERNATE SITE NO, 2 CORP _OF ENGINEERS Quantity S/unit ($1,000) 1 1,340,00 1,340 1 400,00 4oo 1 32h, 00 32h 72" 350 15 26.2 30 600 18.0 3,000 0.75 2.2 30,000 2 60.0 25 210 5.2 1 420, 000 420.0 613.3 10,000 5) 50.0 6,000 5 30.0 1 1,500 1.5 1 3,000 3.0 1 60,000 60.0 300 40 12.0 2 30,000 60.0 2,790 250 607.5 754 700 527.8 38,000 1 37.7 350 250 87.5 1,567 cy cy LB LB EA Ls ” Hneo uF CA cy CY LB EA 350 30 3,000 30,000 25 1 10,000 6,000 300 2,790 754 38,000 350 TER REVIEW S/Unit ($1,000) 1,340,00 1,340 400,00 400 324,00 324 724 75 20.2) 600 18.0 1.30 3.9* 2 60.0 210 Site. 500,000 __ 500.0" 613.3 5) 50.0 2 30.0 3,000 3.0# 10,000 10.0* 300,000 (1) 300.0 4O 12.0) 60,000 120.0* 500 1395.0* 700 527.8 1.30 no. ue 250 87.5 Allow __500.0** 3084.7 TABLE D-4 (cont) Cost CORP OF ENGINEERS STONE & WEBSTER REVIEW Account Number Description or Item Unit Quantity S/uUnit ($1,000) Unit Quantity S$/Unit ($1,000) O4.3 ACCESS ADIT AND STAGING AREA Excavation CY, 3,180 15 238.5 cy 3,180 1D 238.5 Rock cy 1,360 15 20.4 cy 1,360 ie 20.4 Common cy 95 600 57.0 cy 95 600 57.0 Reinforcement LB 4, 800 0.75 3.6 cy 4,800 1.3 6.2* Excavation (Adit) cy 215 200 43.0 cy 210 HOO 86.0" Rockbolts, 1" x 10° EA 130 300 39.0 EA 130 300 39.0 TOTAL - ACCESS ADIT 4O1.5 Wu7.1 ou.5 POWER TUNNEL Tunnel Excavation (Rock) CY, 21,763 225 4,896.7 cy 21,763 hoo 8705.0* Concrete Lining CY 4,889 600 2,933.4 CY 10,800 800 (2) 8640.7 Reinforcement LB 26h, 450 0.75 183.3 (Bo 2h, 450 es 317.8% Rock Bolts, 1" x 10° EA 8,338 210 1,751.0 EA 8,338 300 2501.4% Portal (Including Secondary Rock Trap, Transition, Staging Area and Haul Road) Rock Excavation CY 17,014 30 510.4 cy 17,014 50 850.7* Overburden CY 150,009 10 1,500.1 cy 150,009 10 1500.1 Concrete cy 172 700 120.4 cy 172 700 120.4 Reinforcement LB 11,100 0.75 6.3 LB 11,100 1.3 1H .5* Rock Bolts, 1"x14' LA 90 460 Hid [A 90 "60 wit Rock Bolts, 1"x7' EA 130 2715 35.7 EA 130 275 35.7 Rails and Tracks UF 800 50 no LF 800 50 oO Testle Ls 1 100,00 WOOL Ls 1 100,00 100 __ TOTAL - POWER TUNNEL 12,120.7 22,867.7 On.5 PENSTOCK Steel, "8"0 (1B 1,063,000 2.50 2,657.5 LB1,063,000 H.15 (3)N, 011.5 Ring Stiffeners, Exp. LB 74,410 3 223.2 Anchors, Anchor Stupporst Concrete Support Piers C4 190 300 57 cy 190 700 133.0% Concrete Anchor Blocks cy 16 300 4.8 cy 16 850 13.7% TOTAL - PENSTOCK 2,9h2.5 4558.2 o7 POWERPLANT 07.1 POWERHOUSE Mobilization & Preparatory Work Ls 1 120,000 120 Ls 1 120,000 120.0 Excavation and Concrete Ls 1 230,000 230.0 Ls 1 230,000 230.0 * Unit Price Adjustment TABLE D-4 (cont) Cost CORP OF ENGINEERS STONE & WEBSTER REVIEW Account Number Description or Item Quantity S2Unit {$1, 000) Unit — Quantity S/Unit ($1,000) 07.1 POWERHOUSE (cont) Building Superstructure Ls 1 72,000 72 Ls 1 350,000 350.0* Misc. Building Item Ls 1 97,000 97 Ls 1 97,000 97.0 Bifurcation & Ls 1 36,000 36 Ls 1 150,000 150.0* Branch Pipe Valves EA 2 145,000 290.0 EA 2 145,000 29U.0 TOTAL - POWERHOUSE 845.0 1,237.0 07.2 TURBINES AND GENERATORS Turbines, Governor & LA 2 308,500 617.0 EA 2 617,000 (4) 1,234.0 Cooling System Generators & Excitation EA 2 600, 000 1,200 EA 2 600,000 1,200.0 Equipment . A TOTAL - TURBINES AND GENERATORS 1,817.0 2,434.0 07.3 ACCESSORY ELECTRICAL EQUIPMENT Switchgear, Breaker & Ls 1 211,00 2i1 Ls 1 211,000 211.0 Busses & Station Service Unit Supervisory Control Ls 1 317,000 317 ts 1 317,000 317.0 System Misc, Electrical System ts 1 36,000 Jt 36 Ls 1 36,000 36.0 TOTAL - ACCESSORY ELECTRICAL EQUIPMENT o7.4 AUXILLARY SYSTEMS AND EQUIPMENT Neating & Ventilating Ls 1 7,000 A is 1 7,000 7.0 Equipment Bridge Crane LS 1 120,000 120 Ls 1 120,000 120.0 & Misc. Mechanical Systems ee TOTAL - AUXILLARY SYSTEMS AND EQUIPMENT 127.0 127.0 07.5 SWITCHYARD Power Transformer Ls 1 222,000 222 L$ 1 222,000 222.0 Disconnects & Electrical ts 1 18,000 18 ts 1 18,000 18.0 Equipment goes . TOTAL - SWITCHYARD 240.0 . 240.0 * Unit Price Adjustment Cos Account t Number 19 30 31 7.6 v7 Description or Item TAILRACE CHANNEL Overburden Excavation cy Rock Excavation CY Concrete cy Reinforcement LB Steel Pipe LB Misc. Steel LB Riprap CY Stoplogs EA TOTAL - TAILRACE CHANNEL TRANSMISSION LINE 115 KV (WITH INSPECTION ACCESS TRAIL) Clearing AC Line Conductors & MILE Single Wood Pole Structures (55 pes) TOTAL - TRANSMISSION LINE BUILDINGS, GROUNDS, AND UTILITIES Maintenance Equipment & Supply Storage Warehouse Ls Quantity NB 20 38 1,900 270,440 27,044 he 2 4O 3.5 TOTAL. - BUILDINGS, GROUNDS, AND UTILITIES SUBTOTAL - CONSTRUCTION COSTS ENGINEERING AND DESIGN 10% ENGINEERING AND DESIGN 8% SUPERVISION AND ADMINISTRATION 10% SUPERVISION AND ADMINISTRATION 8% SUBTOTAL - PROJECT COST CONTINGENCY 30% ° CONTINGENCY 20% TOTAL PROJECT COST INTEREST DURING CONSTRUCTION TOTAL * Unit Price Adjustment JS 10 25 300 o. 2. es 30 7,000 2,500 65,000 250,000 TABLE D-4 (cont) 15 25 50 ($1,000) a ac - =HNeuVnHoso lownunsuu ~ cS S oc 100.0 227.5 327.5 Unit. Quantity cy 48 cy 20 cy 38 1B 1,900 LB 270,440 LB 27,044 cy ne EA 2 AC 40 Mile 309 us 1 34 »301 Si ($1,000) 10 0.5 25 0.5 300 11.4 0.75 5.2 2.25 608.5 30 67.6 30 1.3 7,000 14.0 709.0 2,500 100.0 150,000 1050.0* 1150.0 250,000 250.0 250.0 40, 346.0 4034.6 4034.5 48,415.2 14,523.8 62,939.0 2,884.0 65,823.0 NOTES (1) (2) (3) 3000 # Elevator (Passenger freight type) suggested due to material & equipment in gate control room. Concrete lining necessary in pressure tunnel. Unit price difference penstock is of special fabrication and transportation; special welding and handling at the site is required due to penstock thicknesses, we would recommend the higher unit price. Unit price includes stiffeners. Turbines & Generator prices given by COE are typical of purchased price quotes we have received. Our price includes both purchase and installation. "m'', we would like to see documented the 50 percent contingency factor (see m above). The slides at the April 23, 1982, briefing showed a transmission line design based on a 115 mph wind with 150 mph gusts. The report shows a 50 mph wind. This inconsistency should be clarified. The transmission lines are designed for multiple metorologic As_in comment conditions. Without ice loading, they are designed to withstand 115 mph wind with 150 mph gusts. With radial icing on conductors of up to 5 1/2 inches, a 50 mph wind load is applied. The 10 percent contingency factor is unrealistically low. The costs for lands and rights-of-way should be reflected as economic costs. (pages 55 and 56, paragraph 8.2.3C and 8.3.3C) The 10% contingency was arrived at after consulting with several Alaskan transmission contractors. The cost of right-of-way acquisition are included in the interim report. The estimate will be reviewed in detail during Phase II o hh ct o oO study. The 30 percent contingency factor for this overland alternative seems low when compared to a _1C percent factor for a coastal route. This difference should be documented. The costs for lands and rights-of-way should also be included. (page 62, paragraph 8.7.3B) The cost of right-of-way acquisition is included in the interim report. Due to the timing regarding the Power Authority's authorization to proceed on this alternative, work was still in progress and a high contingency was warranted, at che time the summary report was issued. 39 Small Hydroelectric Sites i. The present cost of the small hydroelectric sites alternative ($93.8 million) is nearly identical to the Silver Lake alternative ($92.9 million) without electric space heating. However, the data used for the present cost analysis is very preliminary and comparisons between a * alternatives may be premature. Cost comparisons are essential when ranking alternatives even at an assessment level. All assessment level cost estimates are of a preliminary nature and will be until more detailed engineering is accomplished. We acknowledged that little information is available for the Sheep River Lakes and Lake 1488. These sites appear to be economically attractive and should be considered in future expansion studies. However, field problems can compound in developing these sites. Mobilizing and operating three remote stations instead of one can present operations and maintenance problems, which can not be fully quantified. In accordance with instructions from the Power Authority, we have reanalyzed the small hydro option based on the Retherford Low, Retherford Mean (Level 0) and Level 2 forecasts for the present day diesel fuel costs, Operations and Maintenance Costs based on the 1982 APA budget for Solomon Gulch hydro, and land acquisition and reservoir clearing costs. In addition, we have adjusted the timing to obtain the lowest possible project present worth cost. Figures H, I, J show combinations 3, 4, and 5 for small hydro based on the Retherford Low forecast. Other small hydro combinations for higher load forecasts were addressed in the interim feasibility assessment and will not be repeated here. Present Worth, $ 16° Combination 3 (Figure H) 92,200 Combination 4 (Figure I) 89,300 Combination 5 (Figure J) 104,900 Combination 4 is best economic alternative. 40 We agree that the data used for the cost analysis is preliminary as we have conducted no field investigations for these sites. However, the economic comparisons are useful when attempting to obtain the least present worth cost alternative. As shown in Table A, development of Silver Lake is clearly the "best cost" solution at any growth scenario projected for Cordova, if regional requirements are to be met. To provide power only for Cordova, then within the accuracy of current estimates the combination of small hydro sites is essentially equal to Silver Lake and both should be pursued to develop more definitive estimates. 41 Figure H DIESEL ENERGY, 102 MWh LAKE 1488 DIESEL SMALL HYDROELECTRIC COMBINATION 3, RETHERFORD LOW-GROWTH SCENARIO FOR CORDOVA A1082042 Figure | : ” o = Ss Oo c w é w LAKE 1488 DIESEL SMALL HYDROELECTRIC COMBINATION 4, RETHERFORD LOW-GROWTH SCENARIO FOR CORDOVA A1082040 Figure J CRATER LAKE ENERGY, 102 MWh DIESEL SHEEP RIVER LAKES SMALL HYOROELECTRIC COMBINATION 5, RETHERFORD LOW-GROWTH SCENARIO FOR CORDOVA A1082041 The cost for the small hydroelectric alternative does not include diesel reserve capacity nor does it adeauately D. pUatery. consider the importance of timing. These costs are considered in the economic analysis. See interim report Figures 9.3-1 through 9.3-6, Hydroelectric Combinations 1 and 2, and the respective economic analysis for each alternative attached. It appears that OMB did not have the Economic Data (Volume 4) during its review of the interim report. 42 Power Creek 13 - The Army Corps of Engineers has been investigating the technical feasibility of the Power Creek hydroelectric site near Cordova. Apparently the site has a number of geotechnical problems which precludes the development of a large storage dam above Ohman Falls and limits the site to a__run-of-the-river project. However, the Corps of Engineers’ letter states that "the report draws subjective conclusions against hydropower development of this stream" and recommends that the Power Creek alternative with diesel backup should be presented to the city as an alternative to be given consideration." It does not appear that the Power Creek alternative has been adequately considered or included in the small hydroelectric site alternatives. Our Power Creek study was done with full knowledge that the Corp of Engineers was continuing to pursue this alternative. We frequently discussed progress with the COE and our work complemented rather than duplicated their effort. Unfortunately, due to budget limitations, the COE report on Power Creek was not issued in accordance with their original schedule (March 1982). A draft copy is now being completed for submittal to their Portland Office for review and approval. It is our understanding that the draft report indicates a benefit/cost ratio less than 0.9 and recommends that Power Creek not receive further study. The technical problems described in the interim report effected the Project's Capital, Operations and Maintenance Costs. Based upon our work and the work done by the COE, we believe that Power Creek was given adequate consideration, and we concur with the COE that Power Creek should not receive further study. 43 4 - The report assessed several options for coal-fired electric generation. Because of "reliability, conventional design and intermediate load efficiencies", the preferred option includes two 6 MW stoker-fired boilers. The present worth of the capital costs for this option is given as $56 million. However, the present worth of the capital costs for two 6 MW fluidized-bed units is estimated at $48 million. No information was presented on the heat rates of each option or the comparative advantages in fuel consumption. Considering that fluidized bed boilers tend to be more efficient than conventional boilers, it appears as if the fluidized bed option is most cost-effective. From a conceptual viewpoint the fluidized bed boiler alternative might be considered most cost effective. However, from a practical standpoint, the application of this "state-of-the-art" technology in a remote area would present problems. Utility operating experience with demonstration units indicates that there are operating and maintenance complexities with fluidized bed boilers that can only be handled by a staff of skilled operators The CEC has experienced difficulty in recruiting and holding trained operating personnel for its diesel plant. Operating a "state-of-the-art" power generating facility with fluidized bed boilers is difficult under best conditions and would be extremely difficult in a remote area with limited skilled manpower such as Cordova. Due to complexities inherent in the operating and maintenance aspects of the fluidized bed option and its operation, the stoker fired option was selected for further evaluation. 44 iS A coal-fired power plant has potential for waste - heat utilization. However, the report did not give consideration to this potential or attempt to determine the benefits which could occur. Sources of waste heat in coal-fired power plants are condenser cooling water, equipment bearing cooling water and stack flue gasses. The temperatures of these heat sources are generally limited to 105°F, 120°F and 220°F, respectively. Since the flue gas heat source must be maintained at the elevated temperature to have effective plume dispersion in the atmosphere, this source cannot be utilized. The cooling water waste heat sources from a coal-fired power plant could be utilized by distribution to public buildings as with the diesel waste heat distribution system. However, the economics for installing a system from the existing Eyak diesel plant are better than from a coal-fired power plant sited at Fleming Spit, because the existing Eyak diesel plant is located much closer to the center of town. In addition, the temperatures of the coal plant cooling water sources are lower than from the diesel generators, making this heat more expensive to transport. As discussed in the reponse to question 8, the use of diesel waste heat recovery resulted in slightly lower present worth costs than for diesel generation alone. For the three different Cordova load projections, the net present worth savings were $1,300,000 or less in each case. The coal plant waste heat savings would be less than this value due to the further distance from Cordova and lower waste heat temperature. Even with this savings, however, the coal plant with waste heat recovery is not competitive with other alternatives. Another option with coal-fired power plants is using process steam, or water heated by process steam, for district heating. In a coal-fired power plant this process steam may be taken at its highest energy level in a high pressure superheated state from the boiler exit or at a lower energy level such as a lower pressure saturated state from turbine extractions. 45 These extractions for process steam lower the overall efficiency of the coal-fired plant. Lowering the plant efficiency would make tne coal-fired plant economically less attractive from a power production standpoint. 46 Regional Options Lome This review does not evaluate the various regional options or _ the sale of Silver Lake power to Copper Valley Electric Association. It is assumed that the Load forecasts and power supply options are consistent with other reports. Please refer to Volume 2 of the interim report, " Cordova Power Supply Study Regional Power Supply Alternative", which contains regional load forecasts and power supply options which we believe are consistent with other reports. As described earlier, a regional evaluation was performed which included the sale of excess Silver Lake power to CVEA. For this evaluation, the Battelle, Plan 1B, Mean Load and Nonsustainable Government Spending load projections for Valdez-Glennallen (CVEA) were used. The CVEA Nonsustainable Government Spending load projection has the lowest growth rate of any of the Battelle projections. The two Battelle load projections for CVEA and the additional energy requirements over Solomon Gulch output are shown on Table C. When the Cordova load requirement is added to either CVEA load projection, it is clear that a significant load exists beyond Solomon Gulch capacity. This implies a regional need for additional generating capacity, such as Allison Lake and Silver Lake. This is illustrated in Figure K which shows the relationship between Retherford low (CEC) and Battelle's Nonsustainable Government Spending (CVEC) load projections, Solomon Gulch capacity, and Silver Lake capacity. Based upon the economic's to date, Silver Lake is economically superior to Allison Lake and it would be in the best interest of the region to build Silver Lake initially and then Allison Lake. 47 Silver Lake has an additional regional advantage, as recommended in the interim report, due to the large storage available at Silver Lake. The combined operations of Silver Lake and Solomon Gulch may further increase combined firm power production. Lastly, previous reports have discussed the ALEYSKA Pressure Reducing Turbine (PRT) alternative as a possible energy source for CVEA. We have received a letter from Aleyska, dated October 11, 1982, in which they state “Aleyska Engineering Department has just completed a study of the relative merits of a PRT. Based on the results of this study, Aleyska does not t believe that installation of a PRT is appropriate at this time.' Therefore, the PRT is at this time not a viable energy source. 48 TABLE C Battelle Plan 1B CVEA Load Projections (Glennallen/Vaidez) Mean Load Forecast Mean Load, Solomon Gulch Additional CVEA GWH Output, GWH Energy Required, GWH . 1982 42.0 41.0 120 1987 6rS) 41.0 20.5 1992 98.8 41.0 S78. 1997 117.6 41.0 76.6 2002 139.5 41.0 98.5 Nonsustainable Government Spending (NSGS) Load Forecast NSGS Load, Solomon Gulch Additional CVA GWH Output, GWH Energy Required, GWH 1982 42.0 41.0 10) 1987 5330 41.0 12730 1992 68.8 41.0 2120) 1997 85.0 41.0 44.0 2002 99.6 41.0 58.6 Liotsoty ~— COMBINED CEC & CVEA LOW ENERGY DEMAND “—SILVER LAKE HYDRO (56.4 GWh) — CVEA ENERGY DEMAND NONSUSTAINABLE GOVERMENT SPENDING BATTELLE PLAN 1B 4—— SOLOMON GULCH HYDRO (41 GWh) = = 2 > ° c - 2 w = < Ss c - Oo w = aw — CEC ENERGY DEMAND LOW RETHERFORD CVEA — COPPER VALLEY ELECTRIC ASSOCIATION CEC -— CORDOVA ELECTRIC COOPERATIVE Figure K COMBINED CEC & CVEA LOW ENERGY DEMAND 17 - The comparison of present cost of alternatives (p. 10-9 and 10-10) are backwards. The cost of the base case (diesel should be the numerator rather than the denominator when calculating cost/cost. The revised total present worth of the most competitive alternatives is presented in Table A. The ratios in that response have the base case diesel in the numerator as you requested. 49 18 The yearly present cost calculations are based on the total annual costs (Table 9.2-1) which includes amortized capital costs instead of capital costs applied to the year in which it is incurred. APA procedures require the latter approach. The advantage of this approach is especially apparent when phasing in different projects such as the small hydroelectric alternative. During the period of performance of this study, the FY 82 Power Authority economic guidelines were in effect. These guidelines specifically require the economic analyses to be performed in the manner shown in Table 9.2-1. The following is an excerpt from the "Standard Procedures" section of the FY 82 guidelines: "5. Capital costs are treated in the following manner: (a) Calculate the investment cost as of the project's on-line date. The investment cost is the sum of the capital costs over the construction period plus interest during construction at 3 percent. For a project with a one-year construction period, investment cost can be assumed to equal the capital cost. (b) Calculate the equivalent average annual cost of the investment over the project's economic life using an interest rate of 3 percent. (This is the annual uniform interest and amortization payment.) (c) Assign the equivalent average annual cost to each year from the on-line date to the end of the planning period." The suggested method of analysis would be in nonconformance with the FY 82 Power Authority economic guidelines. 50 19 The report included the economic analysis print-out of only one alternative. These printouts are critical to reviewing any study. The consultant should not consider that assessment or recommendations will be accepted without providing detailed support data such as economic analysis printouts. The single economic analysis printout included in Volume 1 of the report was intended solely as an example of the analysis performed and not as detailed supporting data (see page 9-3). Since SWEC is fully aware that detailed support data is critical to reviewing the study, two supplementary data volumes were provided the Power Authority as part of the Interim report. One of the volumes contained technical data, and the contained copies of the printouts other for every final economic evaluation performed during the study. It would appear that the supplementary volumes were not provided to OMB. Dd 20 - The statement that the "rank order of alternatives ‘s not sensitive to variation in energy demand" is questionable. Variations in the assumptions may be greater than differences in the rank order. The statement on page 10-10 regarding the insensitivity of rank order to energy demand is based on the results presented on pages 10-9 and i0-10. Since this study represents an "Interim Feasibility Assessment," cost uncertainties are inherent due to the lack of detailed information. If a decision regarding the preferred energy option is to be made in a timely manner, it must be based on a comparison of alternatives with reasonable assumptions for system cost and performance plus consistent economic analysis parameters and methodology. The system cost and performance for each alternative included in the report represent, in SWEC's judgment, the most likely to occur. In addition, the FY 82 Power Authority economic guidelines, which were strictly followed in SWEC's analysis, provide a consistent economic’ evaluation. On these bases, SWEC ranked the alternatives on pages 10-9 and 10-10 of the report for three different energy demamd forecasts and concluded that for a regional solution the "rank order of alternatives is not sensitive to variations in energy demand." No new data have been presented that would change that conclusion. 52 - The "Cordova Power Supply Interim Feasibility Assessment" has a number of inadequacies. To summarize ln There are numerous inconsistencies between the data in the report and its interpretation. Some of these inconsistencies are brought qut in this memo. (35 The report is incomplete. Statements are made without adequate support data. he The report includes a number of questionable assumptions. As pointed out by the Army Corps of Engineers, the report seems biased towards making the Silver Lake option work out. 4. The report recommends virtual commitment to the Silver Lake Project without fully developing its technical, economic, or environmental justification. To ___ recommend that "preparation of necessary permit and license applications to be pursued _in Phase II of the study" is premature and does not give the impression of an cbjective evaluation of alternatives. We do not agree that there are numerous inconsistencies between the data in the interim report and its interpretation. We have performed within the requirements dictated by the Power Authority and good engineering practice and believe the statement to be unjustified. The report is not incomplete. It is an assessment report and does not provide the same level of detail as a final feasibility report. The report assesses potential project resources and potential site hazards within the scope of work established by the Power Authority and provides the basis for comparison and ranking of alternatives. We do agree that at the time of the interim report (June 1982) it would have 53 been invaluable to have more site information for Silver Lake. However, as of October 1982 no site geological or environmental investigation has identified a fatal flaw or changed the basis for recommending Silver Lake as the preferred alternative to the Power Authority. We now have confirmed the geology and identified a potential source of concrete aggregate. We believe the Corps of Engineers would agree that Silver Lake is an acceptable alternative for Cordova's energy requirements based upon their negative findings regarding Power Creek. Both the COE and SWEC are concerned about providing the best possible Silver Lake estimates and they will be reviewed in detail as part of Phase II of this study. We do recommend a commitment to proving the feasibility of the Silver Lake Project. We believe this is required to avoid duplication and additional expense to the Power Authority. The economics are clearly in favor of Silver Lake as a regional solution. 54 22> It_is recommended that APA not accept the consultants recommendation when contracting for the Phase II study. A more comprehensive effort is needed to meet statutory and regulatory conditions. Based on this review, it appears as if; (1) Silver Lake, (2) small hydroelectric sites, (3) fiuidized building load generation, and (4) the diesei base case should be evaluated in greater detail. Emphasis should be placed on construction startup timing. In addition, the load forecast should not include electric ee ee space heating and more than one forecast should be used. The interim feasibility assessment report is not intended to be a final feasibility report, rather it is intended to be an assessment of generation alternatives. We understand that a more comprehensive effort is needed to meet regulatory requirements to determine feasibility. It is recognized, as shown on Table A, that the small hydro alternative has the lowest present worth cost for the one case of the lowest load projection and supplying the Cordova load only. However, Silver Lake remains the "best cost" alternative when considered on a regional basis and a feasibility study of this alternative is appropriate. 55 Alyeska pipeline RVICE COMPANY 1835 SOUTH BRAGAW STREET, ANCHORAGE, ALASKA 99512, TELEPHONE (907) 278-1611, TELEX 090-25-127 October 11, 1982 Mr. Eric P. Yould Executive Director Alaska Power Authority 334 West Fifth Avenue Anchorage, AK 99501 Dear Mr. Yould: Your letter of September 7, 1982 references discussions with the City of Valdez concerning the possible installation of a power reducing turbine (PRT) in TAPS to furnish power to the Valdez- Glennallen power grid. Such discussions have occurred. Alyeska's Engineering Department has just completed a study of the relative merits of a PRT. Based on the results of this study, Alyeska does not believe that the installation of a PRT is appro- priate at this time. Sincerely yours, Td. ~~ F. G. Turp President mr 1211 RESOLUTION 82-2 RESOLUTION FROM:BOARD OF DIRECTORS OF THE CORDOVA ELECTRIC COOPERATIVE A RESOLUTION URGING LEGISLATIVE FUNDING AND CONSTRUCTION OF THE SILVER LAKE HYDRO ELECTRIC FACILITY AND CONSTRUCTION OF A TRANSMISSION LINE FROM VALDEZ TO CORDOVA WITH A TAP TO SILVER LAKE. WHEREAS, The Alaska Power Authority, in conjunction with Cordova Electric Cooperative and the City of Cordova has conducted a study entitled: CORDOVA POWER SUPPLY INTERIM FEASIBILITY ASSESSMENT, and; ‘ WHEREAS, This study has shown that the lowest cost electric energy option available to Cordova is construction of the Silver Lake Hydro Electric site with the associated transmission line, and; WHEREAS, Energy surplus to the requirements of Cordova will be available in the early years of this project, which may be sold to the Valdez, Glenallen market, and; WHEREAS, The cost of electric energy produced by this project will be determined by the amount of debt financing required; NOW, THEREFORE BE IT RESOLVED, That the Board of Directors of Cordova Electric Cooperative supports the construction of the Silver Lake Hydro Electric site to produce elsactric energy for Cordova; BE IT FURTHER RESOLVED, That the Board of Directors supports construction of a transmission line from the Silver Lake site to Cordova to deliver this power and a transmission line from Silver Lake to Valdez to sell excess power; BE IT FURTHER RESOLVED, That the combination of projects listed above be termed "THE CORDOVA ENERGY SOLUTION" to indicate to all that it provides a long term solution to Cordova's energy needs; BE IT FURTHER RESOLVED, That the Board of Directors urges 100 percent State of Alaska Equity Financing of this project. ae RN e PASSED AND APPROVED THIS 25 DAY OF Sore ycherc ’ 19 $2. Secretary APPENDIX ASSESSMENT COST ESTIMATES Preface This Section of the Appendix contains Assessment Cost Estimates for Van Cleve Lake, and Tiekel River sites at River Mile 11.3 and 13.5. a so1080 __ ESTIMATE - SOE CLIENT STATION ESTIMATE NO. JO NO SHEET NO HEH SKA Waa ete Cua ee de DE: PTH ANTITIES BY CHECKED B} PRI A5s€sSMENT ESTIMATE — Van Creve LAKE GR Na _| y DATE ‘APPROVED NEAR CORDOVA, PLASKA LL Wisfer __\ aa DESCRIPTION Ce SURES | “WaT aera MATERIAL LL Leees ana TOTAL [wav sours ; I eee ae TT it *DENOTES CONTRACTED WORK Hi TT | ih 9 301, 200 ‘A 601080 ESTIMATE ; CLIENT 2 p q STATION A i, ESTIMATE NO JO NO ‘SHEET NO DESCRIPTION OF WORK cs TY Yaw, te LAKE Jouanpyigs av CHECKED BY PRICES eo} | ASsessHent ESriMatvé - Van Creve LAKE AGS Nhe) NEAIe CokDOvA, QLASKA - ae = add t DESCRIPTION QUANTITIES WAT MHURATE MATERIAL Lasor TOTAL MAN-HOURS | _|_M = Tr IL i a4 | wrake Wakks # Power Conduir a | 7 ie i" El a4) | LAKE Tab Owen. 2ock ¢ reas Teed) | | TO | — TASH LACK C ste.) [ta teu |-vooo ~ ConereTe sd cn ev | Gd | SELLE = Hinowance Fok. LYst SHor oF PhuGll Lume | Jt REMOTE BLAST Fak. INTAKE GATE CHA+BER || — BewWFoRCEMENT dS tot Nc Cin. ACCESS TVNNE ks fo = ExC@avation Crock) M,000.C¥|| SOO 2480 ey || 700- — Stkuctukan ConcRetTé | on ey || 880 a L ~ ABO_TON 12600 — £ocK ‘h) | 2000 | 35 — SreAPPING Csreexs ) 24 oN ||4000 —_JyTakE Gare Cite! Lt! / 100 251) 1 [sa,200 ~ Mise Sreen | 200 raw|| 4200 NANA = |] 75,200} L = 3000 * Toky — ft. - One (1) HELICOPTEX. PAd Lue | *DENOTES CONTRACTED WORK _ = je ~& wu ESTIMATE Hi ON AuASKA Power HuTHORITY da eae dene TT 2 se ie DESCRIPTION OF WORK ||| ASSESSMENT | ESTIMATE |- ner Crusve Lene PAG Aa Neak. CokdovA, ALASKA TILE Tit aeeeteezee ETL IDL VIII | Naan DESCRIPTION QUANTITIES wae Se eRATE MATERIAL LABOR MAN-HOURS [ nl | 04.2 | Coors) TT HH — One C1.) Exeoteican Powe FEED || LunP || 7 | wit STERL bow TR AEDS C So _| EEN te Lit HM eee OT Ts | — Dae C1) Seevice BuiwdinG || avnp | Ly Saeeee ATE — Newarereine & GrovtinG | wo EEL cea IT | 04.3 | Power Tomes CM «Vl ou) HEEL PCT fee PEE EEE — Excavation Crock) Ney Soaer| 400 vn TTT — Concrete Linies _||45,500 c¥|| 800 LEI BELA es c = __ 500 reall 2200 4th LT ttt ESE - Rock Bots Ci" x 10’) | 40,000. |.450 LL Hooke = Arar —Csreeu 400 Tont|-¥00O | Wap piac Ma a aa TTT [Loe | PULL a eae a cae NTA TCT aoner| 450 ~~] LLL LY | lage eee ees MM a ATH ELH 25m eerol—— LTT HL — Cpex Boers Citgrin'h) | ynoo _fasol “IU i AE: — SQreabewe 12. Ton 42001 I LE EEE |= Ewer Sropnoes ¢ Gunes Greer)| 35 row |toool EE A — SO_7aa_ Haar ee ul LEE ELL = Pecrap Bune ComPu. Soxsp | asoacl 75_ LLL TN “DENOTES CONTRACTED WORK /50,/80, 500 a 801080 ESTIMATE eek (EF deeage Power. Aarapaurs "Von Cuan nee [| Bypi.at [oy a? DESCRIPTION OF WORK AssESSHENT Est HATE a Van (Q5 ve LAKE wllf2 | 77 Nenk. Cordova, ALASKA APTA | en tr DESCRIPTION I QUANTITIES MATL MH/RATE MATERIAL Medios ome il Lf | | oy.s | Pewsrace # Toweitn. Aoemu Sec. i — Excavation Crocx ) lg20acy || 50_ | = Sr Pewsrack Cneu BIEVRC NS 218" ron||83D0 ai | wal — | , REINFORCEMENT SO* fey 90 Taal 2.00 | = “fen Bours Cig 210") _lases_|.as0! Srbepe ee ae — Poorman. Excavation ENTRANCE |e5,a00 ey || si ier cee ‘ c a Bi Ul it 1 esr NTE = Aocess oad: B/aust to PaeTAL Meee UU ANTI O4.to | SLANTED Sukeace PenstacKs CA). oe TE i 4 cee ee a Mee — Vanve House % Hecess Ue IC ee =I STEEL, melt CK ( INSTALLED eS 5 1Y700 TOA! 8.300 — Conceete (T-brocns # Grade Beats )\\a400 cy || Baa. | 4 = eee lll ED Ton. gud |. Rock Lorts (1h x 10’) 1000350 |, i | = Ta (2) Bucubcapials (8g to 2x 200) Tart 18.30 a | HZ | 3.5/@ 350 231) Lu al MAE: | ILA Bees {Hh *DENOTES CONTRACTED WORK 7 i Th ql LTT il iI i i : 53536, 750 ‘a 601080 ESTIMATE CLIENT STATION, , nt ESTIMATE NO JO NO | sneer no hy ASKA OWEN? WH Ty Vi ai a DESCRIPTION OF WORK P a HIN Eve LAKE QUANTINSS BY tah ¥40¢ ad. et = AssessNENT Estrin ATE - VAN Creve LAKE 7 GP | re are | fale pe ACEOUND DESCRIPTION __ ff quannimies: MATT cost ie MATERIAL \asor TOTAL MAN-HOURS ) cel ace | tH rT TTT TTT | L—]| Powebdouse Sreyerune |p | |p HT al ttt wee | [LT THe rT | t= pA seecaveous Marys |) Ht + i 1 | | Extra Excavatiaw hf Sst coe i 1 Ade Re et . soovon tt = ttt tt. - : DENOTES CONTRACTED WORK 9,080, 400 a corso ESTIMATE CLIENT STATION ESTIMATE NO 730 NO SHEETNO ALAS! Van Ceve Lane | ea a 7 | HssESSNENT ESTIMATE - VN Creve LAKE fee Ni CEIEVALULL DATE Bz ‘APPROVED. Nenk Cokbova, ALAsKA Ea eet ee CL! UNIT COST MAN-HOURS MATERIAL LABOR NO. | MATL [MH/RATE 4 ACCOUNT DESCRIPTION QUANTITIES feelin dooms worl AURTATTT | *DENOTES CONTRACTED WORK Tie5o)} noe) & 601080 ESTIMATE DESCRIPTION OF WORK STATION eAsKka Creve Lace _| HSSESSMENT Essr7HATé - VAN Creve LAKE DATE M4 “Wwf ‘APPROVED ESTIMATE NO JO NO ‘SHEET NO. 7 QUANDIIES BY CHECKED BY PRICES BY (A Je Nad oF ACCOUNT NO DESCRIPTION QUANTITIES UNIT COST “MATL _[MH/RATE MATERIAL a ALA p LABOR TOTAL avons “DENOTES CONTRACTED WORK 4 601080 ESTIMATE CLIENT STATION _ ESTIMATE NO JO NO ‘SHEET NO o DESCRIPTION OF WORK : : LEKEL x ver Cu} | QUANTITIES BY |S | xfer tacts Se 2 DATE a A “[aPrnoven - AssessHlENt £STIMATE - RIVER MILE 1.3 SITE |" nfie~ RECOUNT DESCRIPTION QUANTITIES want Re RATE MATERIAL LABOR TOTAL MAN-HOURS | [ed iI ] [or | roa Pece Woex ore | || THT ; O31 Hocess oub CH ot) ETE ~ oan Cor Am 104.000 +f. 3° ~ Som REMOVAL 4 res anne 42° | — Fue Gm (Crean GRANULAR dp 250 000.61 7.50 lJ o3.2_|7A | been cee | ; SMB To OVERLAND T-LINe_) = ace BREESE |} *DENOTES CONTRACTED WORK Ss a : 3/81, £00 eaioes ESTIMATE | CLIENT 7, 0, r ) STATION — 2 E : 3 ESTIMATE NO. JO NO ‘SHEET NO LEBEL Kd QUANTINIE x CHECKED BY = DESCRIPTION OF WORK JUANTITIES BY HI PRICES BY NAB = = oat = [arenoveo = HS5SESSMENT ESTIMATE - RIVER 1416E (113 SITE ufifer ACCOUNT UNIT COST NO. DESCRIPTION QUANTITIES “MATL MH/RATE MATERIAL LABOR TOTAL MAN-HOURS Peta — ConleR£TE 2500.0. il a | | = Leweo uoO* fay | a5 tocilAle lal - LOGS 3x Ho _|| 50 reall Yao I - Cues 20 Taek - | | \ i *DENOTES CONTRACTED WORK a aay : oer 23 935, 000 a 601080 ESTIMATE La all CLIENT STATION 4 ESTIMATE NO 40 NO ‘SHEET NO EXEL Rive. CH 4 J DESCRIPTION OF WORK QUANTITIES BY CHECKED BY PRICES BY _| WAG ae ‘APPROVED f ER MILE 1.3 SITE, upsfer ACCOUNT UNIT COST NO DESCRIPTION Cea TES MATL MH/RATE MATERIAL LABOR TOTAL [man nouns a — DvERBVADEN 2 one esr mete ULE pesgacdey o>? , “DENOTES CONTRACTED WORK Ap, 000 cll £5,°° | YOZ,TOO & 601080 ESTIMATE DESCRIPTION OF WORK OY AeASKA Powek Aurnokity Fieger Liver. C2 ESTIMATE NO JO NO £Y0L. 24 | Y #9 SHEET NO QUANTITIES BY a) DATE ‘APPROVED Assessoent ESTIMATE -RWER MILE 11.3 SiTe “Lsfr> ACCOUNT DESCRIPTION auantinies [Path Cost MATERIAL LABOR TOTAL MAN-HOURS, ee 4 f+ |_ Qo Seuzway 2B Auwiae Pron. Ta To | | | u = — - TH | Olo.d |OxCAVATIAN PAT Li | — DvVEPAURDEN as cnt || to = Aen —_|b 75,000 cyl) 25 | | 06.2. | Coveke re 2000 cy} 400 LL | | Dlo..3 OZ | WARE heme at) |Corceenam — sacer Pie # woaners | 5 ron L3Q Tan 3S. Ton ATION 40.10 = ae phot aol LT 4 HT Hu AO |_| ede | 2 TTT 2a et ol fi] | il tH fi Gk 1 “DENOTES CONTRACTED WORK ~ 18, 138,500 oe «soos ESTIMATE CLIENT y D My STATION ee Pwvek_C } ESTIMATE NO JO NO ae oD DESCRIPTION OF WORK QUANTITIES BY \ CHECKED BY us BY AsséssMenr £,STIMATE - RIVER MILE 113 SITE “alse |r" dd DESCRIPTION | avantinies ait Oe MATERIAL LaBor TOTAL MAN-HOURS Poze CONT 'S : ae | | — Jrasveacks Csreen) A ra | — Guaes ©.3 sens) Csreen.) | Ao row vand|—_| Pt = 5 aw Seevce Crane Caeiace) LEA |w50a I dele = E E ea0 er 4 75 = | — Burrswa 4 psa. JSreen za. ron| wool. | | O7.3 Powek. Tanaléke Ca.s ere », ——— 1 EL — Lock Excavartian __ 74000 us] Mol | — Concketé Linck. san 94) B00 -— Rack Barts _l* fh x 0'k Hp00 eal 350) — SeAPRIMG _C SIEE, L300 rom W200. | 4 — MEWEORLEMENT YD zor} Badd) AH EE LE LE Edd Lor Likes Subee Cxauger | || | . Rocx Exenyation W850. vo 5|| OL ALE = Conehete Lier ___} 750 3750 |<] 4] LES = RENEORCEMENT | XQ ran 200} |. | HEEL — Roce Bovts 1 gx 1d! \1o0.ea\aso SAE =Sraaneng —Cstece.) Aton |moool—_| | | 1 AL — SA oon iL - _ — TT - eb ft Th 228 tate Th ele, “DENOTES CONTRACTED WORK 4 601080 ESTIMATE | CLIENT STATION ESTIMATE NO TIEK EL. MvER. C12 DESCRIPTION OF WORK QUANTITIES BY JO NO SHEET NO CHECKED BY PRICES BY oF DATE A i ‘APPROVED HsSESSMENT ESTIMATE -RWER MILE }/-3 SITE TN, ‘cr! x ACCOUNT DESCRIPTION 7 QUANTITIES maT See aRTE MATERIAL LABOR | TOTAL MAN. Hours| = rane | | tf HT — Roce Excavation tana vo} 450 }ti ttt tt ts cS — Concrete hiner. 415003, 750. || — REINFORCE MENTO To cone — Mace Barts i’ ¢ x wo’ __|4450.€dl 3 LL — Seabee Csreen) 10.5100 i { : — EMekeewoy Srobiace Csreez\ Ma raoll4l LEE pee = Euwes Csteen AO ra|4 TEL iste = _Srepkawe Csreen) “DENOTES CONTRACTED WORK | - | EEL LVAD Penstacn 2 Zinwet.— agers (Eee eeeee Eeele LL L L Mock LxcavaTioN——__—fettoo wif voo lL atic — Opueretre_Lineeh_——————dgamrand aol TTT LTT eb ae — Rock Baers i"hx o'h _ |ayoo caso. Sat TTT _ ESTIMATE CLIENT ALAS KA Power AvurhoRiTy STATION TIEKEL H Rwer_ Cee ee Jo 1410. 24 freewd 3 | DESCRIPTION OF WORK QuaNriTies BY N CHECKED BY PRICES BY be Ogee ial Assessnent Estinare — RiveR MLE fl. 3 SITe Silee/of/eeal [ole [ RCO DESCRIPTION 1 LABOR | TOTAL MAN-HOURS 3 ROWIERINOUSioluLL oy ulna aes O8.| | PowERNouUSE STRUCTURE Hike —Hommwi2zarioN ¢ PRee vie | — Excavation al — Cone Ceré ii fected ~ RemlForeencdt — SUPERSTRICWRE Loe — Wise, MATERIALS | —TAlL RACE el ee 08-2 | Seueeieau Vatves 2 180,002, —__ = VALVES E eLtateate | retell | Zen - Evten Evaadariond f| ietetel Ete — Evra Cole pert Lone | — ExrR a RevifoRe ere Alta al — tise “DENOTES CONTRACTED WORK K a sororo ESTIMATE CLIENT STATION TLE ESTIMATE NO 720 NO [sneer no Y Anaska Power. Hurnobutt ——" Texen eiver. Cu “yoL.ed |" Ao 9 | DESCRIPTION OF WORK QUANTITIES BY NB PRICES BY ASSESSMENT ESTUAATE-RIVERI1N1LE //.3 SITE Te wae He ACCOUNT DESCRIPTION QUANTITIES mart Soe Rie MATERIAL 06.3 | P/M EquPeent rn | | — Power TRANSFORMERS Pi 13.8 Kv [A30 KV Ax IS HUA) 09.0 5 TCH’ ea = LLL ; | — Civ, Wokxs LLL ~*DENOTES CONTRACTED WORK ast & 50108D CLIENT a Power. Hurnokary 77, DESCRIPTION OF WORK ESTIMATE STATION TEKREL OVER. C3) ACCOUNT ESTIMATE NO JO NO. QUANTITIES BY cc { CHECKED BY NAB PRICES BY ay fe o Be 9 DATE ufifrr ‘APPROVED LABOR MAN-HOURS C3 yenks - Pawer an Lie 29788 )- “DENOTES CONTRACTED WOKK 7eee mn TINE EE WO [Enenechine A Desien Cov) a ep aedne THT 1 — eee le nn i) 7 13.0 ICowtTinGency © 30%) a a TUL LD ye sca ee | a HUET 1} ants ESTIMATE wee eA oKA 0 w TiEKEL RIVER. pee ed |B DESCRIPTION OF WORK ssessMenT ESTIMATE = kwh MLE 43.5 STE 2 ke _ NAb e 1 ZSINA LIVER A Llofer en DESCRIPTION quantities |g aT] OS aE MATERIAL LaBor TOTAL MAN-HOURS| THT Tf OL ¢ PREP Wak | LaetP FI 111 bsbalddadg| —__] sini Crt } jf | diy | 4800 aceeh i | Seer or =) Ge i I ; HTT EEEEEEEEE | 23.4 | ; d Eo aida eal Cette LL | IT] [ WE MiCHAR DAS ON HIGHWAY? 16.5 me || 11 — (2) Svan Beunaes Coa £7.) | 2 Neca anal 4d ~ Loan Cur /2 ouo,anncy| 4/30 es 4h 5 Erect = Sow Rétovah VS sana eyll 9° | EE — Fun Contan Gkaven) <5 ry yxooooer 7° ee liao | 03.2 | Cenocarian of VALOE2 -GLENAAEN| ttt eae | N 7ieawsen SSian LivE Series : LE Ae ~— Mew Link ConsThvetian US.KY aeien lei ee LEE ELL LY da PE TT EI ere a LE LT 103.3 Wenncaon of Teans-fuaskn Ppenite | ie a JUL PO | New LENGTH _ || A3 At |.900,000 + ads Lig oe TEE oo : =| id eo aa ta pd od “DENOTES CONTRACTED WORK a Peoter a 24, Vee 6, 000: ESTIMATE 4 601080 oss tcl oes ENT STATION ESTIMATE NO 30 NO ‘SHEET NO. nee OF WORK ZjEKEL ; AWER Srr€ | ouannines wy etd ag 28 | ij AssessHENT £STIHATE WER Pie 725 SIT je "WAB DATE TarPnoves A wer “Lee l@~ ACCOUNT UNIT COST | NO DESCRIPTION QUANTITIES MATL |MH/RATE MATERIAL —t LABOR TOTAL MAN-HOURS N = : 5 E N | NOTE £ COFFER, DAN vith 2. ee, *DENOTES CONTRACTED WORK 36, 4549, 000 4 801080 ESTIMATE STIMATE NO DATE CLIENT STATION | & | Auvska Power AuTHorRiTY TiEKE Liver. in DESCRIFNON OF WORK ASSESSMENT ESTIMATE RIVER ME 13.8 sive |e * KA I TSINA_ RIVER. ufee fer Tr) ‘SHEET NO y, OF CHECKED 4B PRICES BY ‘APPROVED UNIT COST MATERIAL LABOR TOTAL an-nours| aoe DESCRIPTION ouanTcs MATL [MH/RATE - + las i ven TU Ml o ___l50, 200 CY °° — ocx isn poo Cyl /5,°° a | PT i O52 RoCKEL N na 50 NTT ee o \3a,000 CY TTL {SDD Teshl 24D0 - 4,700 2¥ ZOD os # | 3.35 taal 2lc00 oe eae 2XG | SPuway z Penn Ge Poon tt —}— “DENOTES CONTRACTED WORK ESTIMATE a 601080 CLIENT im STATIONS LL we 7 ER ESTIMATE NO JO NO SHEET NO / £L ALLY. oF DESCRIPTION OF WORK AISSESS NENT ES TIMATE RIVER ANLE “3. 5 STE | wantines ev x ice PRICES BY DATE APPROVED (L Tawa River. wfie[C— ACCOUNT DESCRIPTION auantimies geht [RHA aie arena Lasor TOTAL MAN-HOURS| = — j= 4 e | Ota | Concrete _|Booon0.cY sof | — Rock Bours (1g x 10's ) 450 £8l| 750 THEE ATT Lora | Zone, Vs TAWK C.3t200') | — Excavation Chock) — CONCRETE LiinG Datel lagaet Wey il - Lack Bours Cs" fx io'L) COU eel nae Pyare ULE LIU ian ee LE “DENOTES CONTRACTED WORK ESTIMATE CLIENT 4, a 5 2 STATION TERK EL Ay = ESTIMATE NO "dale ay pe a DESCRIPTION OF WORK ASSESSHENT ESTINATE RIVER AVILE 43, 5 S/TE QUANTITIES BY R ha = PRICES BY | Ay dus ae Coneuwence wf Tan LWe = [eee ACCOUNT DESCRIPTION auantinies [Pg eht eet ait MATERIAL LABOR TOTAL MAN- HOURS | 0%.3 | Sukce CxaHper nat | THT cea = Excavation Crocx ) 43D0_CY || -/50. ditt tty -— Cowereté kine ann cyl 250 TILL LETT bh - RénNfO_100* Ley ___||40 raw || | ae = . Ly |anoo ealssa |] | ATT ~ STRAPPING dN A re oool— | | LEE EE = Srp Laas Csrece 37 lwa00 EEE a — Guires Cres exten) |v | tna LEE ~- Hoist 40 Tan | 2 des | — PREFAB SWeCK lan el 5 | LLL | a74 | Penstacx Ena % TavK 0o' | | oe — Excavation Crock) | quanev|-/50 is _ — Sreé, Pewsrock sd 2 ln | LEE EEL a - Conereré Liék Le 20.crl| 750 ULL - Bemro Csteen) | 55 zoned 1 tk Pensrocx Exp Ys zanx von’ | sit TLE BAGG: | — Srecu Péenstack 2 pv llazn0 : LL — ConChkETeé id a ey! 250 Lt LE - REmfo Csreen) 55 aw ftuca0 TIL TLL - Rock Bours C1" bx lob) | 45 eal.aso 4 Ie oan ala a i oh a 7 ia 1 = — 1 1 al 1 “DENOTES CONTRACTED WORK ~ B4,903, 750 & 801080 CLIENT ESTIMATE STATION ESTIMATE NO JO NO EKEL RIVER. [Y¥/OL. AY | a* B DESCRIPTION OF WORK ASSESS MENT ESTIMATE River MILE AS. 5 SITE JUANTITIES BY M TT ne PRICES BY Vi A VER ‘DATE the fer ‘APPROVED. aaa DESCRIPTION QUANTITIES watt Cae ae MATERIAL LABOR TOTAL MAN-HOURS pa ote. | ArEvRCATIDA t Atco Exri-n tavaP ai 28 | Power. House 7 pee ae 08.1 | Power Hovse ~TTRVCT URE, | gu — Mob & eee Worx = Ex0AvATionl ee ee YA pee CE NEDO INCL. AH — Sve Srhucruke — Msa Materia | — Th LACE 08.2_| AurékeLy Vanves ia - Yauves (.3.4'¢ @ 250 psi) LB _bes = (rae ee a Hire Peter ete ILO UL LUMP 1 | - Extee Covchere 9 FEWER a I TT il t *DENOTES CONTRACTED WORK & 801080 CLIENT DESCRIPTION OF WORK YSSESSHMENT ESTIMATE STATION RAVER (ULE 13.5 5 ESTIMATE NO JO NO CHECKED BY av ‘SHEET NO PRICES BY ITE QUANTITIES BY y GH OM“ NRO He INA Liver aie DATE “Wfele> eer ACCOUNT DESCRIPTION + Sea ees Laat OS ATE MATERIAL LABOR TOTAL aan nours| | 08-3 | Poweitwiouse Laursen, ee eed =e) 4 (ae | ee eee z LT — GENERATORS £ L£xCuTATION | & || 7 I | | Su peevsady Conran Sys7en| 1 Set - sou. Puase bus, B&caver, Pkorecr| 2 een = a SysréHs HW hvetP Wr ince Ei | - E 1 He ee alt — PJ CRANE ee fe | - (1sa. Mecon. SysreHd | LumtP |) | = Tk VE) | ee 72 ees | eee 08.4 | SwiTeHVARL ie esi a\a|a | — £QuUIRMENT AMP Ht 4 PCy Wards AauMP || cl | 08.5 |Zaawsaussion Live (A530 8) 3.5. 241 Len, 7 (mE Srvé To ketocaTe T-A T= Line) i et eee ESN PG RIG Hen esLLaLLeeHiiat ee i ate Sella — ConDvucroes INC | ie | a TOowERS 2. Ze poe ae +H seers Ee ee | Stay) ees S| £51) 07 H “DENOTES CONTRACTED WORK 6,820 COO a 501080 ESTIMATE CLIENT STATION Tip. ee Auaska Power Avtaakury —" Tiexen Rwek. DESCRIPTION OF WORK A. ISsESSMENT ESTIMATE ESTIMATE NO. RIVER NILE 13.5 SITE QUANTITIES BY mM DATE a 0% /. SHEET NO a 3 CHECKED BY PRICES BY NAB ‘APPROVED Ue ler MATERIAL LABOR TOTAL MAN-HOURS C wa MK iver_ ACCOUNT UNIT COST pos DESCRIPTION QUANTITIES |"QaTL_[MH/RATE APA FY-82 GuU/0ELING PREPARED Ob THE BASIS OF *DENOTES CONTRACTED WORK APPENDIX ENGINEERING MEMORANDA Preface This Section of the Appendix contains Engineering Memorandum on Environmental/Geotechnical Field Investigations at Silver Lake, Geologic Notes on Alternative Dam Sites (Copper River Basin) and Hydropower Suitability for two Copper River Basin Lakes. Environmental/Geotechnical Investigation at Silver Lake: A Status Report as of Mid-October, 1982 DOWL Engineers October 1982 The 1982-1983 environmental/geotechnical investigations currently underway at Silver Lake are based on a revised "study plan" dated July 4, 1982 which incorporates’ the agency comments to date and is based on the assumption that the results of the study effort will be used in the prepara- tion of an Exhibit E to a FERC application. Following an early April scoping session with the requlatory agencies and a preliminary site visit to establish gaging locations on the Duck River and at Silver Lake outlet, the field program was initiated in late April. Among the principal activities undertaken and accomplished to date: establishment of several continuous recording stations for water quantity and temperature and/or surface water and ground water temperatures. Numerous site visits of varying duration during the period May - October to: - provide for an interagency site visit. provide for a site visit by the local utility and city government provide photo control for the topographic mapping and survey support for the other field activities continue discharge measurements on a routine basis and develop correlations with similar watersheds initiate and maintain studies on water quality both in the lake and river as well as the lagoon establish and maintain precipitation gages at the head of Silver Lake and at the outlet of lower Duck River observe avian and terrestrial species in the project area and determine the extent of utilization of the area by these species map vegetation and classify wildlife habitat in the project area conduct a geotechnical program that included mapping of the regional geology, site specific geology (structure, stratigraphy, micro-structure, and sur- ficial geology), detailed geology along the road and penstock routes and at the powerhouse site, core drilling (four holes) at the dam site and spillway location, identification of geologic hazards, and an assessment of available construction materials. - conduct a fisheries field program related primarily to anadromous fish in the lower Duck River and the tidal lagoon and coordinate these activities with ADF&G in anticipation of a future instream flow assessment. - conduct a sampling program for invertebrates (both freshwater and intertidal) in the lake, river, lagoon and Galena Bay - inventory recreation and subsistence use of the resources within the project area - conduct a reconnaissance level survey of the cul- tural, historical and archaeological resources within the project site. establishment and operation of a field camp (for 55 days) at the mouth of lower Duck River to permit daily observations to support the on-going hydrology and fisheries investigations and to document temperature, salinity and tidal variations in the lagoon as well as provide general support to other elements of the field program. literature reviews, agency contacts and briefings, local village and community contacts and briefings, and the preparation of a draft socioeconomic assessment. The major elements of the 1982 field season are nearly com- plete and the field camp located at the lagoon on lower Duck River is closed. However, the hydrological stations will be Maintained throughout the coming winter season and routine visits to the sites are scheduled that will gather hydro- logical data, maintain the "ice test" facility, and make appropriate biological observations. Additional instream work relative to fisheries will also be conducted during a 2-3 day site visit in early November and the “ice test" facility installation will be accomplished during to or prior to this period. The following salient points can be provided at this time relative to a preliminary analysis of the work to date: there are no terrestrial ecological constraints to the proposed development. there are mo archaeological or cultural resource con- straints to the proposed development though at least two cultural sites were discovered in the near vicinity of the dam and reservoir project area. preliminary hydrological data tends to confirm the his- torical USGS hydrograph as well as the conservative water forecast used in the preliminary analysis by SWEC. while the lower Duck River - lagoon system is a major spawning and rearing area for both pink and chum sal- mon, it appears that the proposed facility and its sub- sequent operation provides an opportunity for enhance- ment of the fisheries assuming regulated release of water. it also appears that any impacts related to the con- struction and operation of the proposed facility could be mitigated at relatively low cost particularly with reference to the lagoon. all socioeconomic impacts identified to date are posi- tive. no rare or endangered species have been identified in the project area. reconnaissance level underwater investigation of the construction dock site revealed no invertebrate popula- tion that would impose any constraint on the proposed development. although final data reduction and analysis is not com- plete, no major geological constraints to development have been identified. Four drill holes have confirmed surface observations of highly competent rock at the damsite. Pressure tests of these holes showed negli- gible losses. No faults are known to cross the damsite and faults in the general area are probably inactive. A side channel near the proposed damsite has been investigated by hand probes, one drill hole and seismic refraction. Preliminary results from these methods show that bedrock is present at no greater than 10 feet below ground surface. Avalanche tracks, steep slopes and local areas of peat are the principal factors which will influence the siting of the penstock and power- house. Careful attention to location and design should allow construction without extraordinary costs. A large materials site has been located at the southeast end of Silver Lake. This gravel has low percentages of some of the sizes needed to make concrete. However, the quantity of the deposit as a whole is sufficient to allow screening and retrieval of the size fractions necessary for an appropriate mix design. Rock quarry sites have also been identified, should crushing of bedrock be necessary. The proposed dock site would be founded on bedrock and no unusual geotechnical problems are expected. no resource agency to date has raised any major issue (objection) relative to the proposed project. ing f Qe a & a | From ,Conhauous | sircam ii Downs Engineers yi tS Daily discharge. of Duck Awe tote ct ei i ¢ ’ zs peeve imine 2 cccied uae aH Plime enceetiss oH EET a : a inet stebaaeraessinn a ab ta, AYEKST Duck Iriver gage rr of . ie la | i | feeel| | | | Ss eet ge. B12. Na : | i ‘ dischas rom lhe | uw | | | | | | i lowe} yt PAR Yee ee 4 4 ane 14) 39 i yH STAT MMM ii AG PIN Srttnam potene Sonos © Geologic Notes on Alternative Dam Sites The following lakes and rivers were investigated as possible alternative hydropower sites. Photogeologic analyses of false-color infared photographs and examination of existing geologic maps provided the basis for these notes. No on- site fieldwork was conducted. Should any of these locations appear feasible a more comprehensive assessment of the geologic conditions would be necessary. iis Lake 1120 (Cordova B2) Importance of proximity to Ragged Mountain fault (long considered active) 2-1/4 miles to the east should be evaluated to determine seismic design criteria. However, Tysdal, et al, 1976 interpret lack of 1964 movement and mapping along fault trace to mean that the fault is not presently active and does not constitute a serious earthquake hazard. Potential for smaller quakes probably does exist. A strong lineament is present in the Lake 83 valley. Generalized Bedrock Description: Orca Group (lower Eocene and/or Paleocene). Interbedded sandstone and volcanics. Sandstone is rhythmically deposited, dark-grey, fine-grained and forms tightly cemented beds grading upward into siltstone (locally cal- careous sandstone and siltstone are present). Volcanic rocks include greenstone, tuff, tuff breccia and pillow basalt. Locally these rocks are weakly metamorphosed. (Tysdal, et al, 1976) Abutments -- No problems were observed with using the bedrock for abutment material. as East Fork Little Bremner (Valdez A1) Park and wilderness classification. Generalized Bedrock Description: Valdez Group sedi- mentary rocks. Weakly to strongly foliated metamorphosed marine argillite, siltstone, sandstone, and conglomeratic sandstone. (Winkler and Plafker, 1981) Abutments -- Bedrock at the head of a narrow bedrock canyon would form the abutments. Photogeologic work showed no obvious problems. 3. Summit Lake (Valdez B1) Park and wilderness classification. Generalized Bedrock Description: Haley Creek terrane. Metamorphosed plutonic and sedimentary rocks. Complexly deformed and tectonically mixed. All rocks cut by veins of quartz and other minerals. (Winkler and Plafker, 1981) Abutments -- The dam would probably need to be located approximately 1 mile downstream from existing lake outlet in the narrow canyon. The lake outlet may be unsuitable due to an alluvial fan on the north side and a probably moraine on the south side. Cleave Creek (Valdez A3) Generalized Bedrock Description: Valdez Group sedi- mentary rocks, see #2 East Fork) The Cleave Creek glacier is approximately 3-1/2 miles above the dam site and extensive channel fill and build up of sediment behind the dam may be a problem. Potential avalanche (rock and snow) hazards exist for the dam and penstock. Abutments -- The bedrock in the abutment area appears poorly consolidated and careful field checking of this site is recommended. Tebay Lake -- lower outlet (Valdez A1) Park classification. Generalized Bedrock Description: Valdez Group sedi- mentary rocks, see #2 East Fork) Abutments -- The east abutment is in bedrock and its competence is probably acceptable; the west abutment is probably bedrock, however additional study is needed. Tebay--Falls Creek (Valdez A2) Park and wilderness classification. Generalized Bedrock Description: Valdez Group sedi- mentary rocks, see #2 East Fork) Abutments -- Bedrock knobs, which appear to exhibit near vertical beds form the abutments. Low relief behind dam and to the sides of the abutments may mean accessory saddle dams would be necessary. Tebay--Hanagita (Valdez B1) Park and wilderness classification. Generalized Bedrock Description: Meta-plutonic rocks of the Haley Creek terrane. (Winkler and Plafker, 1981) . Abutments -- bedrock. No problems observed. Tasnuna River--Mile 20 (Valdez A4) High stream load may cause rapid sedimentation behind the dam. Generalized Bedrock Description: Valdez Group sedi- mentary rocks, see #2 East Fork). Penstock/powerhouse--broad, braided channel, and steep bedrock walls may cause some routing problems. Abutments -- Dam width could be up to 0.3-0.5 miles, to reach bedrock. . Tiekel River-Mile 4.8 (Valdez B4) Depth and permeability of channel fill could be an important factor in determining the cost of a dam. Generalized Bedrock Description: Valdez Group sedimentary rocks, see #2 East Fork) Transportation corridor would need relocation. Relocation of the town of Tiekel would depend on dam size and exact location. Abutments -- bedrock, dam width of approximately 0.4 miles would be necessary to reach bedrock. 10. 11. 12. Tiekel River-Mile 11.3 (Valdez B4) Site below Tiekel Cache. Lower transportation corridor would need to be moved. Generalized Bedrock Description: Valdez Group sedi- mentary rocks, see #2 East Fork) Abutments -- Bedrock for the abutments is probably incompetent. This site needs very careful fieldwork. Channel fill from both the main channel and one side channel may be an important factor in evaluating the cost of the dam. Tiekel River-Mile 13.5 (Valdez B4) Site above Tiekel Cache. Transportation corridor would need to be moved. Generalized Bedrock Description: Valdez Group sedi- mentary rocks, see #2 East Fork) Abutments -- Left abutment possibly colluvium requiring additional excavation to bedrock. Potential dam width of 0.4 miles. Allen Glacier (Cordova D2) Generalized Bedrock Description: Metasedimentary rocks, undivided, of the Valdez Group. These rocks consist of thick, rhythmically bedded sequences of multiply deformed metamorphosed turbidites which include metasandstone, meta- siltstone, argillite, slate, and phyllite, with rare beds of pebbly argillite. (Winkler and Plafker, 1981) Penstock -- potential avalanche hazards exist along the penstock route. Abutments -- abutment material is probably bedrock but may be of poor quality. Photo quality was excep- tionally poor. References Cited Tysdal, R.G., et al, 1976, Surface features and recent movement along the Ragged Mountain Fault, Alaska: Map MF-782 U.S. Geological Survey. Winkler, G.R. and G. Plafker, 1981, Geologic map and cross sections of the Cordova and Middleton Island quadrangles, southern Alaska: Open-file report 81-1164 U.S. Geological Survey. ~~ DOWL_ Engineers 4040 “B” Street Anchorage, Alaska 99503 Phone (907) 278-1551 _( Telecopier (907) 272-5742 ) MEMORANDUM TO: Norm Bishop, SWEC FROM: Bob Burk/Jan Mulder DATE: October 20, 1982 RE: Hydropower Suitability for Two Copper River Basin Lakes WO #D50024 At your request we examined two lakes within the Copper River basin as possible alternatives to the proposed Silver Lake damsite. Both of these, Van Cleve Lake and an unnamed lake tributary to Sheep Creek, are glacier dammed lakes formed where valley glaciers blocked off ice-free side valleys. Both lakes drain subglacially and have emptied abruptly, with little or no warning, several times since 1900. This has been documented by both aerial photography and personal accounts. The unnamed lake, for example, was mapped on the 1959 (minor revisions, 1973) U.S.G.S. Cordova C-2 quad (Figure 1). However, aerial photos taken during August 1978 show this same lake as drained (Figure 2). Austin Post and Lawrence R. Mayo, "Glacier Dammed Lakes and Outburst Floods in Alaska," (U.S.G.S. HA-455), describe the occurence and formation of glacier dammed lakes as well as the hazard presented by catastrophic flooding. Personal accounts of these floods are also included. Van Cleve Lake drained catastrophically in both 1909 and 1912. The 1912 event was caused "perhaps from the draining of a marginal lake and swept down the Copper River from Miles Glacier. It raised the water level 12 feet at the railway bridge east of Childs Glacier and swept away 1600 feet of railway trestle 20 miles further south." The unnamed lake caused flooding during the summer of 1962 or 1963. According to R. Kennedy, "frightened animals were seen running along the Copper River Highway without regard to traffic. Road maintenance personnel witnessed a great flood in progress on Sheep Creek, which had been tranquil only hours before. By morning, a mile of roadway had been washed out and the streamflow had returned to normal." Another flood from this lake again washed out part of the highway in 1965. There are also reports of earlier flooding (Figures 3 and 4). Lewis E. Dickinson Maurice P. Oswald Kenneth B. Walch Melvin R. Nichols Memorandum Norm Bishop October 20, 1982 Page 2 Locating a structure within an area subject to glacier outburst flooding is very risky. Even when no surface lake is visible, considerable water may be stored in or under glaciers and may be rapidly released. The inadequacy of the usual methods of storm frequency analysis as well as a lack of base-line data compound the problem. Due to changes in glaciers, new lakes may form, old ones disappear, or the frequency and/or volume of discharge may be altered. The possibility of a glacial advance within the lifetime of the dam cannot be overlooked. Although it might be argued that glacial retreat is more likely, this is not a certainty, especially in this area. A dam on the Sheep Creek tributary shown on the U.S.G.S. quad sheet is probably feasible although the abundance of recent glacial deposits makes careful fieldwork mandatory. Such a dam, however, would depend on the integrity of the McPherson Glacier or mean that a second dam must be constructed near the glacier. Analysis of stereo air photographs shows no geologically sound site for this second dam. The combination of poor abutment material and the dynamic nature of glacier and flood activity in this area should rule out this lake from further consideration. If a proposed project can tolerate a dam 1-1/2 miles wide with construction mostly underwater then Van Cleve Lake is a possibility. A glacier dam is unsuitable for dependable power production. BB:JM:kk Enclosures 5 Wl XS iO} \\ Figure 1 Figure 2 ozozsliv <a Sete BRIDGE AT SHEEP CREEK, EAST OF VALDEZ ON THE RICHARDSON HIGHWAY DENSE LOW WILLOW AND ALDER GROWING ON THE FLOOD PLAIN INDICATE SEVERAL YEARS WITHOUT FLOOD ACTIVITY, BUT ‘ABSENCE OF LARGE TREES SUGGESTS THAT DAM- AGING FLOODS HAD OCCURRED EARLIER. BRIDGE FORMS A CONSTRUCTION IN THE FLOOD PLAIN. ALASKA DEPARTMENT OF HIGHWAYS PHOTOGRAPH, DATE UNKNOWN. Figure 3 tzozsliv SAME BRIDGE AT SHEEP CREEK PARTIALLY BURIED BY DEBRIS RESULTING FROM A GLA- CIER OUTBURST FLOOD FROM A TINY GLACIER DAMMED LAKE ‘NO. 23) SEDIMENT BURIED MUCH OF THE WILLOW AND ALDER BRUSH. BUT AS THE FLOOD DID NOT CARRY AWAY THE COTTONWOOD TREES AT THE EDGE OF THE FLOOD PLAIN THIS FLOOD COULD NOT HAVE BEEN OF MUCH GREATER VOLUME THAN PREVIOUS FLOODS APPROXIMATELY 7.5 METERS (25 FEET) DEPTH OF DEBRIS WAS DEPOSITED AT THE BRIDGE SITE: LARGE-SCALE EROSION UPSTREAM MUST HAVE TAKEN PLACE TO PRO- VIDE THE thee MATERIAL. ALASKA DEPARTMENT OF HIGHWAYS PHOTOGRAPH. SEPTEMBER 1945 Figure 4