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HomeMy WebLinkAboutManokotak Transmission Line Study 1986polarconsult — <i “<= , CONSULTING ENGINEERS AND PLANNERS polarconsult Polarconsult is an Alaskan consulting firm pro- viding a wide range of professional services in cold region engineering and planning, with particular ex- pertise and emphasis in the fields of eriergy and community and regional planning. As outlined below, our staff in Alaska is experienced in many disciplines. In addition, we can draw on an interna- tional pool of talent b i S inavi countries, giving us the tually all types and siz climates. DIL Polarconsult was for engineering, architectur the harsh climate of nor owners had considerab similar work in Denmar ott WAINWRIGHT \ ru, Lhd ENERGY PLANNING energy planning and energym energy ce HIGHSMITH #42-222L HYDROPOWER DE -% small scale projects « RENEWABLE ENERGY wind power utilization « solar energy t ISSUED TO the Faeroe Islands. After several years of providing specialized services to a _ large number of municipalities and remote Native settlements throughout Greenland, a logical step was to offer similar relevant services in Alaska. In 1979, Polar- consult established an office in Anchorage and com- bined international expertise with that of longtime ; ced. in. design and construction. 2nd of talents. The Scan- ar ahead of Alaska in of the problems of living g this experience with id understanding of our pproach to problem solv- nts effective answers to NITY AND REGIONAL planning : ensive land use planning and subdivision layouts planning sing UTILITIES PLANNING AND DESIGN © power supply alternatives ¢ district heating * water and sewer systems © solid waste disposal CONSTRUCTION MANAGEMENT all project types Pie oo4 polarconsult alaska, inc. ENGINEERS ¢ ARCHITECTS ¢ ENERGY CONSULTANTS June 26, 1986 Alaska Power Authority P.O. Box 190869 Anchorage, AK 99519-0869 Attention: Peter Hansen Project Manager Subject: Contract No. CC08-5315 Service Request Manokotak Transmission Line Study Dear Mr. Hansen, As required by the above contract, and as requested, we are transmitting 10 copies of a study on Manokotak Transmission Line. In addition to the study, we include some miscellaneous drill log information. I must say that this study was fun to do as it stretches the imagination. It would appear from the results that if adequate terms can be arranged with Nushagak Electric Cooperative (NEC), Manokotak will no longer have to run their own generator. One item not mentioned in the study is that while In Dillingham we took a brief look at land status for the route around the airport to the power plant. It looks somewhat confused. Sincerely yours, Ea. Qusmne Earle Ausman, P.E. Chief Engineer EA/MS Enclosures 2735 EAST TUDOR ROAD ¢ SUITE 201 * ANCHORAGE, ALASKA 99507 PHONE (907) 561-1933 SECTION II III IV APPENDIX GRAPHS TABLES SOILS LOGS DRAWINGS TABLE OF CONTENTS PART TITLE PAGE EXECUTIVE SUMMARY A BASIS STUDY 1 B ROUTING 1 c DESIGN 2 D COST 6 E MAINTENANCE 7 F RELIABILITY 8 G INTERCONNECTION 9 A UNDERGROUND CABLE ALTERNATIVE 10 B OPERATION & MAINTENANCE 10 c EXPERIENCE 11 D RELIABILITY 11 E COSTS 11 A CONCLUSIONS 13 A RECOMMENDATIONS 16 CONSTRUCTION COSTS & LOSSES W/ PILES CONSTRUCTION COSTS & LOSSES W/ BURIED POLES LOSSES CONSTRUCTION COSTS W/ PILES CONSTRUCTION COSTS W/ BURIED POLES CABLE CONSTRUCTION COSTS & LOSSES W/ PILES CONSTRUCTION COSTS & LOSSES W/ BURIED POLES LOSSES CONSTRUCTION COSTS W/ PILES CONSTRUCTION COSTS W/ BURIED POLES MANOKOTAK TRANSMISSION ROUTE & SOILS SHEET 1 OF MANOKOTAK TRANSMISSION ROUTE & SOILS SHEET 2 OF polarconsult Executive Summary The purpose of this study is to determine the costs of providing an electrical transmission line connecting Manokotak Heights to the Nushagak Electric Cooperative in Dillingham. The Nushagak Electric Cooperative, NEC, has an installed capacity of 4,270 kw of diesel electric generators. Their electrical loads are approximately as follows: NEC kwh Manokotak 1985 April 926,000 May 935,000 June 1,112,000 July 954,000 51,000 Aug 1,057,000 Sept 899,000 82,400 Oct 955,000 43,000 Nov 1,089,000 50,400* Dec 1,070,000 57,900 1986 Jan 999,000 56,500 Feb 1,093,000 51,200 Mar 1,008,000 51,200 TOTAL 12,096,000 469,000* Manokotak's use was about 3.9 percent of the energy generated by NEC. The reported maximum demand for Manokotak was 163 kw. In this report, it was assumed that NEC would sell electricity at their diesel fuel cost of about 9 cents/kwh and capacity would be based on an incremental $300/kw. Manokotak has about 81 metered utility customers with’ the Laundromat and two other community facilities unmetered. NEC has 1037 metered customers. Twenty-four new homes will be added to the Manokotak system at Manokotak Heights. The number of metered customers would remain constant in that the new occupants would be from Manokotak. However, additional households and modern appliances” will increase loads. Assuming an average of 250 kwh/month, the ditterential increase will be 72,000 kwh/year. NEC's energy use is higher during the summer than the winter, and Manokotak's energy use during the summer is very low. Theretore, the addition of Manokotak to NEC should have only small system effects. polarconsult The results of a_transmission line feasibility study are contained herein. This study is to "Determine the technical feasibility of constructing a transmission line from Dillingham to Manokotak (CManokotak Heights) that will be acceptable to Alaska Power Authority, the taxpayers of Alaska, Nushagak Electric, and the City Council of Manokotak." Because of the undefined nature of the term "acceptable", four routes were analyzed, using various voltages, phase configurations, conductor sizes and voltages. A single underground cable case was analyzed. The results of the studies conclude that the least costly case, including losses, was a single phase 7.2 kv underground cable from the Nelsonville area to Manokotak Heights. This case had a construction cost of $301,700 and a combined Cwith losses) cost of $321,700 over a 20 year period. The second least expensive alternative over the same route was a single wire ground return CSWGR) system operating at 22 kv. The construction cost was estimated at $338,900, with losses at $6,400, over a 20 year period. If a SWGR system cannot be used, the third ranking alternative was a 14.4 kv single phase, REA construction system which had a $401,800 construction cost, with losses at $23,900 over a 20 year period. It is the view of the authors that the need for a direct connection to the power plant, when, or if, analyzed would probably be technically unnecessary, and that single phase power can be accommodated by the Dillingham Utility. This study concludes that properly protected cable or SWGR systems will not degrade Nushagak Electric Cooperative's CNEC) reliability, and that Manokotak does not require three phase power. A waiver of the codes may be required to run a SWGR system. The reliability of the SWGR system has been shown in Bethel where such a system is now being used. This study further concludes that the southern route would be the most easily maintained, will best serve the boat launch facility and will more likely be paralleled by a future road. It is therefore recommended that an underground cable or single wire ground return system be selected if it proves to be technically CNEC'S system), economically, and politically feasible. It is further recommended that this transmission line be connected to the Nushagak Electric Cooperatives' system near Nelsonville and follow the southern route "D'" to Manokotak Heights. II SECTION 1 A. Basis Study General: The study basis for this project is complicated by the following factors: 1. The termination potnt Is not clearly established. 2. Several routes can be chosen. ae The decision to go single phase or three phase depends on more than economics. 4, The loads are not well known. 5. Solls and logistics are very poor. Because of these complicating factors, it was decided to look at several termination points and several basic_ routes. This resulted In four different routes. Because of the single phase, three phase uncertainty, both situations were analyzed. Because conductor size Influences not only losses, but support spanning as well, a series of conductor sizes were analyzed for each case. This resulted In a number of cases which were set up and analyzed on a computer. Study results are shown on tabulated tables and on associated = graphs. Results are presented In terms of constructlon cost, and present worth values of losses. B. Routing Basically, there are four routes. Two start at the power plant and the other two routes start 24 miles south of the airfield near Nelsonville. One of each sending end locations takes the practical shortest distance - the second swings south and crosses the Snake River just south of the confluence of the Snake and Weary Rivers. This Is the point where the village of Manokotak Proposes to terminate the road from Manokotak Heights, the termination of the power lines. This river crossing potnt will be used for boat launching and servicing, as it fs only a few miles from Nushagak Bay. The current village location on the Igushik River Is hours from Nushagak Bay. The route miles are as follows: A - Power plant direct to Manokotak Helghts 18.0 miles B - Nelsonville 7 = 7 " 15.0 miles C - Power plant via Snake to Manokotak Helghts 20.5 miles D - Nelsonville " 7 " a 7 16.5 miles Route Descriptions: River Crossings Clearin Malntenance Route Snake Weary Snake Miles Maint. access 845 ft 1056 ft 1850 ft best poor access Imtd. A xX xX 4.8 X B x xX 2.8 x c X 5.2 xX D 4 2.2 X Routes A & B cross the two rivers In a triangle which appears could easily be a flood plain during unusual IcIngs or floods. This triangle between the rivers would restrict summer maintenance to a helicopter unless a boat and light tracked rig or four wheeler were utilized after the river had broken up. A small Hovercraft vehicle could be capable of serving the area, provided It was not called on to transport large loads. Routes C & D, altnough longer, will have better accessibility tor malntenance and they are not In a flood plain. Additionally, if a road [fs built to the Snake River from Manokotak Helghts then the six miles of these routes, along the road, wlll be easy to maintain. These routes being longer will have greater costs, more losses and some Increased chance of failure because of their Increased length. However, they will not be as exposed to river Ice or flood as on Routes A & B. A long river crossing will also be required. This crossing, If overhead, could pose a hazard to low flying air craft. However, It Is not expected that the Snake River Is a major small plane flight route. C. Design General: Basic design parameters are conductor size, voltages and structure. When the voltage Is changed, losses change as a function of the voltage squared. When conductor sizes change, losses change as a linear function. Conductor size and spanning affect pole class and length; therefore, thelr alterations affect costs not only of the conductor itself but of the structures as well. Kelvins law states that the most efficient conductor Is that In which the annual cost of the conductor equals the annual cost of the losses. However, the conductor Influences’ the support costs so the system was analyzed as a whole. Because of poor foundation conditions, It was assumed that the number of structures would be significant In establishing minimum costs. As an example, It costs little more to set a 5' taller structure with a greater span which results In lowered costs. Because of questions of reliability, all conductor spacings were analyzed for galloping. Although single wire ground return was not part of the scope of work, It was analyzed In that It would be ideal for this project. Electrical: Electrical design was simplified for this study. It was assumed that losses were a function of conductor resistance. Power factor In these villages Is high and was’ therefore neglected In the computations whIch were based on ohms law losses per conductor. Single phase line losses were based on data from REA Bulletin No. 60-9, "Economical Design of Primary Lines for Rural Distributlions System." For single phase, REA configuration conductor losses system are predicated on all poles_ being grounded to the neutral and a substantial portion of the current passing through the ground. That Is, the REA takes credit for ground return. As an example, for 1/0 conductor the resistance Is about 0.89 ohms/mile, with a pure Isolated neutral the ohms would be 1.78; REA uses 1.12 ohms In thelr calculations. On three phase grounded and ungrounded systems, the assumptions were a balanced system with no return through the ground. The resistance of the ground for the single ground return was assumed to be equal to that measured on the Bethel to Napakliak SWRG system, 6.3 ohms. Losses were based on the method outlined In REA Bulletin No. 60-9. The assumptions used were as follows: Kwh/year 469,000 Peak requirement, kw 163 Average kw 53.54 Loss Factor 0.84 Load Factor 0.16 Load Growth, percent 2 Interest, percent 9 Capacity value; Incremental/kw $300 Energy value, $/kwh $0.09 Project Life, years 20 A loss value was developed which multiplied the Initial years losses by 12.22 to arrive at a present worth value of the life time losses. A number of different voltages were explored which ranged from 7.2 kv to 22 kv to ground. The light load at the village Is below the surge Independence loadings of the lines. On the higher voltage lines there could be some voltage increases because of capacitance. For final design voltages should be computed. Grounding system for SWGR was comprised of a number of driven copper ground rods’ Interconnected with copper wire. With non-frozen wet silts, marine and other type, an excellent low resistance ground can be easily and economically obtained. It was assumed that there would be three ground fields; one at each end of the line and one at the Snake River for a_ future Interconnection. Reclosers were planned for the sending end as were airbreak switches with fuses for system Isolation. Transformers were assumed for each system with higher voltages than Dillingham. Transformer capacity was standard and was assumed to be 300 kva. Structural General: The structures chosen for analysis on this line were of the wood pole type. For the standard wood pole structure, It was assumed that the poles were set two feet deeper than normal east of the Snake or Weary Rivers. In the high ground to the west, poles were set one foot deeper. This decision was based on discussions with Hal Borrego of Bethel Utilities, Harlan Willis who had been a foreman for Nushagak Electric Cooperative for many years, observations of solls and pole setting depths near Dillingham and in Manokotak, and as a result of solls surveys. The design for structure loading was In accordance with NESC heavy loading which Is four pounds per square foot wind and 4 Inch radial conductor Icing. Conductor tension was based on a very conservative 33 percent under that loading. Pole helght established to obtaln NESC clearance was based on a conservative 33 percent conductor tension under heavy loading. Since heavy loading and ultimate conductor tenslion controlled the conductor sag, It controlled pole spacing, pole heights, and spans for each conductor type. Conductor tensions were selected at a lower value than 40 percent, which Is frequently used, to provide allowance for reduced fatigue from aeolean vibration. Because the country Is open and Icing potential Is not an infrequent occurrence, the conductors and neutral wire were spaced to allow single node galloping up to 600 teet and to have clearance for double node galloping for spans over 600 feet. This spacing followed recommendations In ALCO 4-7 and REA "Mechanical Design for Overhead Lines." The result of these analyses were as shown In the table presented below. From this table It can be seen that the maximum span for 1/0 conductor, as DI1llIingham uses, is 465 feet for single phase 2 wire, and 420 feet tor 3 phase 4 wires. Observations of the Dillingham system Indicate spans in that class but without the larger cross-arms, of ten and twelve feet, and Increased neutral to hot wire clearance as used In this analysis. Poles were all assumed to be Douglas Fir. Poles were analyzed for normal loading, wind loads of 4 pounds per square foot when the conductor was Iced, and heavy loading, winds of 31 pounds per square foot, without conductor Icing. 1 WIRE 2 WIRE 3 WIRES Single Phase Single Phase Three Phase KV Number Number Number Phase Span(ft) Cpole/mi) SpanCft) Cpole/mi) Span(ft) Cpole/mI) Conductor-~------------------------------------------------------ 1 470.00 11.2 450.00 11.7 390.00 13.5 1/0 510.00 10.4 465.00 11.4 420.00 12.6 2/0 550.00 9.6 490.00 10.8 435.00 12.1 3/0 570.00 9.3 520.00 10.2 460.00 11.5 4/0 610.00 8.7 550.00 9.6 495.00 10.7 7#10 800.00 6.6 660.00 8.0 800.00 6.6 7#11 735.00 Te2 610.00 8.7 735.00 7.2 7#12 670.00 7.9 560.00 9.4 670.00 7.9 347 750.00 7.0 620.00 8.5 750.00 7.0 3#8 710.00 7.4 590.00 8.9 710.00 7.4 Since the line has comparatively few turns, and hills. are Infrequent and gentle, spans will be quite uniform. River Crossings: River crossings were analyzed using a guyed lattice tower which was extracted from a Rohn catalog. It was assumed that river crossing towers would set on a pile and would be deadend structures. All river crossings were assumed to be made with 7#10 Alumaweld conductors which give the least height towers which was 140 feet on the largest Snake River crossing, and 50 feet on the Weary River crossing. Crossing Distances: Lines A & B Snake 1056 ft. Weary 845 ft. Lines C &€ D Snake 1850 ft. Wind loads on these structures were 31 pounds per square foot. River crossing clearances were governed by minimum national electrical safety code clearances using 4 psf wind, 3" radtal Ice, and 33 percent conductor tension. The summer clearance, no IcIng, was found to be about 60 feet which Is well above the clearance of approximately 40 foot required by the U.S. Coast Guard for other navigable channels of the same size and usage as the Snake River. A. permit for an overhead crossing of a navigable channel Is required from the U.S. Coast Guard at which time they will set the required river crossing clearance. It may be possible to plow In a cable for the river crossings using a wheeled cable plow and a tractor or winch. This was done tn Cordova across Eyak River and the Carl Brady Glacier Streams. If a cable went out, generally it could only be replaced; not repaired. Pole Support: Emperical Information supports the case where most poles, even In poor ground, can support themselves If buried one foot or more over their normal burial depth. Normal burial depth Is usually about 10 percent of pole helght plus 2 feet. In some cases, these deeper buried poles can be In very wet, saturated stilt or In a peat bog and may not have adequate lateral stability. In such cases it would be appropriate to wind guy the poles. This could elther be done during construction or after or both. The second means of dealing with poor solls was by using piles and pole bands such as Joslyn Mfg Glant No. 1, Stock No. J6850. In this case, a 20 foot pile would be driven 15 feet or to refusal, which ever Is less in the ground. The pile would then have a stub pole clamped to It. The stub pole would be framed and equipped with appropriate. stringing blocks while It was on the ground. Structural design for single wire ground return Is very simple as galloping Is not a problem. The wire Is supported with a simple pole top pin. The 25 kv Insulators used have a much higher rated M&E strength than Is needed. Solls: Terrain types are shown on the photographic maps In the appendix. Terrain types were verified by six soll borings which were made during a fleld trip on May 22, 1986. Solls logs are presented In the appendix. In addition, the results of this survey were further extended by Alaska Department of Highways drill logs from "Matertals Reconnaissance FS 411 to Kanakanak, Mile 3.6 to 6.1, Project S - 04 "(C4)", copy Included. Generally, solls are predominantly organic peat, of varying depth, over-lying silts. Stilts range from saturated to unsaturated In character. Although soil borings did not disclose deep peat deposits, other evidence from excavations and other drill holes near the airport show organic soll depths to 25 feet. Therefore, it can be expected that some structures will end up belIng located In deep, low strength soll deposits. Generally, however, It Is expected that the dominant solution wlll be a foot or so of organics over silt. Of interest during the drilling was the thickness of the active layer. During the drilling It ranged from 18 to 24 Inches. This winter was warm but generally devoid of snow untI1 later than is customary. Because of this relatively thin frozen layer the size of equipment will need to be restricted. This Is born out by communications with residents who state a D-6 is alright on the surrounding tundra, a D-7 may be okay but a D-8 Is out of the question. D. Cost General: Costs were estimated by breaking each Job component Into Its constituent parts and determining the equipment, time and materlals that were requlired. Equipment was brought to Dillingham if it could not be obtained locally. Equipment not available locally was assumed to be shipped to Dillingham from Anchorage by barge. Machinery like D-6's can be rented from several places in Dillingham. A D-6 was assumed to be one of the Indispensable pleces of equipment used to haul poles, rip top frost for piling, pull trailers, haul and help string conductors, clear snow, and walk down small trees. A warm-up shack was to be used with the operation for safety and for tool storage. Material Prices: These were based on Anchorage prices for pole top unlIts and conductor. Poles were priced In Seattle and were to be shipped to DI11ingham by barge. Logistics: A number of different means were explored to provide materlal distribution on the Job. Costs were Investigated to barge up the Snake River, use a helicopter, and spot material with a D-6 and sled. Concern with shallow depth of freeze resulted In checking with locals on the ability to cross the rivers with the equipment. Because of this concern, It was calculated that each river crossing would require flooding to guarantee the requisite Ice thickness. Cost estimates used helicopter spotting as it was less expensive than barging poles up the Snake River and distributing them with a cat. Equipment: Selection of equipment’ was based on a D-6, sled/trailer, warm up shack, Nodwell with auger, Bomardier with plle driver, snow machines, and stringing blocks. Labor: Rates for labor were based on union scale for 10 hour days, 50 work minutes per hour. Since construction will be done In the March - April time frame, It Is very probable that extra overtime will not be required. Staking: Survey for line route was assumed to occur with the combined use of a D-6 for clearing and transport. Staking was estimated at $600 per mile. Anchors: All anchors were of the power-Installed screw type with an assumed depth of 11+ feet. Other Expenses: Contractor overhead was calculated at superviston for five months at $6,000 per month to arrange for material logistics, etc. General contractor overhead’ was estimated at 25 percent, profit at 10 percent with contingencies at 15 percent over the entire job. E. Malntenance In this study there is no value assigned to differential malntenance. It Is apparent that the more complex structures with added conductors wlll have greater maintenance costs. As to comparing deep burial structures with pile structure, there will probable need to be some addition or tightening of wind guys on these structures. However, on pile structure a check and retightening of bands will be required after the poles shrink over a long dry winter. In any event, the entire line will need to be checked after construction In the fall to assure structures are not failing. It Is obvious that SWGR, with Its lower structural loading and simplicity of construction and design, will require the least malntenance. The value of this reduction Is difficult to quantify. There are some times during the year - break-up, and freeze-up, where some line locations, Routes A & B, will be difficult to maintaIn as they are located between the Snake and the Weary Rivers. If there Is an emergency In this section, a helicopter or perhaps a Hovercraft is the best means of maintaining the line. One argument for Route C & D Is that the east side of the Snake River during summer can be maintained from Dillingham and the west bank from Manokotak Heights. If the proposed road Is constructed to the Snake from Manokotak Helghts, then that section will be readily accessible all seasons of the year. If properly trained, the local personnel should be able to maintalIn the transmission system, especially with SWGR. F. Rellability With a conservative design, strong conductor strung at low tension, and Increased spacings, the galloping reliability should be high after the Initial shakedown pertod has passed. Rellability, though Important, Is not of absolute consequence to Manokotak as long as a line Is not down long enough to create excessive use of an emergency standby generator. For Dillingham conductor clashing, or failures, will decrease to an extent the reliability of their line to Kanakanak. But with Increased phase spacing and reclosers, the proposed line should be more reliable than that to Aleknagik. However, with a neutral wire and added phases, conductor jumping during release of Ice can cause splIkes and recloser operation. SWGR has only one wire so there can not be line to ground faults or phase to phase faults from conductor jumping or from galloping. The only types of failure for SWGR Is a broken conductor or an_ Insulator failure. With coordinated reclosers and fuses, Nushagak Electric Cooperative (NEC), should be well protected from failure; they may, however, experience addition voltage spikes. Manokotak will use the line primarily as a source of lower cost energy and a reasonable outage time will be of no economic consequence to them. Currently, Manokotak turns the etectricity off during the day to conserve fuel, so the people have accommodated thelr life style to an Interruptible electricity source. G. Interconnection NEC wants a 3 phase powerline to run directly to their powerhouse. NEC's concerns are that they do not want a line connected near Kanakanak as thelr line Is fully loaded. NEC ts concerned with a reduction In reliability of their system and does not want the unbalanced load of single phase. As-bullt drawings of NEC's system were unavallable for analysis. Manokotak does not require 3 phase as their only 3 phase loads are several small pumps. These pumps can be converted to single phase for a low cost. SECTION II A. Underground Cable Alternative General: Usually URD cable for a distance of 16.5 miles or so Is not an economic alternative. To check this assumption, a case was analyzed for a single phase 1/0 aluminum, full concentric neutral cable with 220 mills of Insulation. The selected case was to operate at 7.2 kv to ground. It was assumed this cable could be plowed In to depths of 36-42 inches. Local Expertence: Local operators claim bad experiences with cable. However, the cable used was manufactured In 1970's and was found to be defective In that the conductor was not In the center of the Insulation. The reason cable may be effective In this case Is the route Is all fine silts and organics and the frost depth In the wooded areas Is about a maximum of two feet. Because of the shallow frost depth, contraction cracking should not be a problem, as the cable will be beneath the frozen layer. Cable Installation: It was assumed that there would be a single run with two D-6 cats; one with a ripper, to break up the top two feet of frost. The same two cats would then pull a cable plow. Splices, which are the weak link of many cable Installations, were assumed to be requlired each mile. Splices could be set In cans, with slack, so they will not pull apart. Single phase sectlionalizers would be used each three miles or so for test purposes. The cable can be plowed across the Snake River during a low tide period when the Ice Is grounded. Ice wlll need to be cleared for this operation. Ramps would be dozed into each bank for transitlIons, as will ramps In small incised stream crossings. Electrical: Rough electrical calculations show that at the cable charging current will be about 12 amps. It Is expected that under these conditions there will be a voltage rise. At 300 kw, the voltage drop Is about 10 percent with a drop of 5 percent or so at current peak loads. A voltage regulator will probably be needed at the receiving end of the system. If the cable option Is used, more detalled calculations will be needed. Losses are expected to approximate, but will be higher than, those used for the 1/0 overhead single phase REA system. Therefore, losses should be about $20,000 per year. Use of higher voltage, 15 kv to ground, would reduce resistance losses but It would quadruple the charging current and tIncrease the cable cost. Polyethylene Insulated cable should be used as It has the lowest dielectric constant which will reduce the reactive component and charging current requirements. i B. Operation & Maintenance Operation of a cable system Is slightly more sophisticated than the overhead. Repairs, though Infrequent, can occur during times when cable fault location and excavation Is difficult. However, with the shallow active layer In this area and the more easily 10 excavated fine-grained frozen solls, repairs should not be as difficult as In other areas of the State where the climate and solls are more adverse. Maintenance wlll require’ special training and tools. It Is not, however, as complex as repalring an engine, which the village routinely does. Maintenance should be low, requiring checks to see If scouring of stream banks has encroached on burlal depths. Because the cable outages are not colncidental with weather, cable outages should have little consequential attect on NEC's rellability. C. Experience Cable was plowed from Eyak Lake to Cordova alrport. This cable has been reliable. Chugach Electric Assoclation (CCEA) reports they are usIng a 30 year life for their local cable Installations. CEA Is using loop teed In thelr densely populated area to provide Increased reliability If there are electrical problems. Their experftence with cable fallures have been due to cut cables during excavations. Excavations will not be a problem In the area as this line Its remote from human habitations. D. Reliability The cable system should be reliable as it is Isolated from weather and outages should be on a random basis. Although reliability Is Important, It Is primarily required for economic reasons, that Is, the cost of repairs, and the time when power can not be purchased from NEC. The single feature that has the potential to create long system down times Is an outage at the Snake River crossing. Therefore, while In the process of plowing In one cable, a second could also be plowed In. The two cables would be connected at each end as It Is best to keep these cables energized. Although there are potential events which could create outages on both cables, complete failure from installation damage or from improper manufacture would be Improbable. Tt: ts Proposed to hi pot all cable for this crossing prior to Installation. System reliability is further enhanced as 220 mi11 Insulation Is specifled rather than the usual 175 mills used on most 7.2 kv URD cables. This added Insulation is comparatively Inexpensive but has a definite effect on rellablility. E. Costs Construction was assumed to use a spread consisting of three men plus two cats and snow machines. A fork lift would be used to load cable. Unloading the reels will probably be done by rolling or skidding the reels off of a sled or trailer. Setting the cable Into the cable plow reel holder can be accomplished with a light A frame and a tag line off of the D-6 winch drum. The Job Is simple and should be very definable with one exception, which Is, the Snake River crossing. This crossing could be difticult as there may be Incised channels and It might be difficult to clear a path through the Ice. However, two lIight cats, one with wide pads and a winch, should be effective for this work. il Because of this uncertainty, contingencies were Increased to 20 percent. It may be desirable to use a semiconductor jacket over the concentric neutral to prevent corrosion of the concentric neutral. If this were done It would add 25 to 30 cents per foot to the cable price or about $30,000 to the entire job. 12 SECTION III A. Conclustons The graph of the pile/pole system for route B (the direct route from Nelsonville to Manokotak Helghts), shows the 22 KV SWGR system to have a combined cost of $331,200. The 14.4 kv single phase REA ltine has a combined cost of $410,000 for the same route. The present worth value of the losses for SWGR with a 7#10 Alumaweld conductor Is about $7,000 and about $21,000 with a 3#8 Alumaweld conductor for the 14.4 kv ltIne. For a burled pole situation the construction costs are higher, with a combined cost of $367,000 for the SWGR and $440,000 for the single phase 14.4 kv line. Route D, from Nelsonville via the Snake River to Manokotak Heights, which can serve the boat launch facility and will potentially be easier to maintain, will have total costs of $345,000 for the SWGR and $425,700 for the single phase 14.4 kv construction. The underground system Is the least expensive system of all. For route D It will have a combined cost of $321,700 for a system using a single phase full concentric neutral cable, operating at 7.2 KV to. ground. The construction cost for this' system, assuming a single crossing of the Snake River, is about $301,700 with present worth value of losses of about $20,000. An additional Snake River crossing might add $20,000. A summary of the results of the computer runs using the most economical conductors are presented In the table below. Presented In the Included graphs In the appendix are analyses showIng construction costs, value of losses, and combined value for all overhead routes, conductor sizes and for two construction types. It Is concluded that SWGR or URD cable will be a highly reliable system and with properly coordinated fuses, and/or reclosures, should have almost no effect on the reliability of NEC's distribution system. It Is also concluded, based on discussions with Moses Toyukak, Sr., that there Is no requirement tor a 3 phase system at Manokotak or at Manokotak Heights. It Is evident that 3 phase transmission Is more expensive for this lightly loaded system. It Is} concluded’ that It Is probable that technically, a connectlion can be made to NEC's system near Nelsonville without creating difficult system problems. 13 TABLE SUMMARY OF SYSTEM COSTS Yost Economical Conductor i Re Sonstruction Econ. Rt. From From Via Constr. Value Combined Cost Iverhead Poles U.G. Cond. Pw. Nelson- Snake Snake Cost $ Losses Size PLNT. ville Weary (S.) $ 7.2 kv 14.4 kv 22 kv 7.2 CN.) hase 169 36 16 386 SWGR cable K 1/0 A xX x 472,800 19,300 492,100 " B x x 424,300 16,000 440,300 " Cc xX x 508,700 21,900 530,600 " D x x 443,900 17,700 _461,600 X 348 A Xx X 533,900 34,200 563,100 " B x x 478,700 28,500 507,200 " Cx x 573,500 38,900 612,400 " D x x 499,800 31,300 531,100 X 348 Ax X 428,500 26,100 454,600 " B x x 387,500 21,800 409,300 " c xX x 456,300 29,800 486,100 " D x x 401,800 23,900 425,700 X 348 AX X 538,800 8,500 547,300 " B x x 482,700 7,100 489,800 " Cc X x 578,900 9,700 588,600 " D x x 504,200 7,800 512,000 X 7#10 Ax X 354,300 7,000 361,300 " B x x 325,400 5,800 331,200 " Cc xX x 377,500 8,000 385,500 " D x x 338,900 6,400 345,300 X 1/0 D X x 301,700 20,000 321,700 vt In terms of rellabIlity, the SWGR or the underground cable would be the most rellable system with the least probabl lity of outage. The 14.4 kv REA single phase system would follow. The shorter the line, the more rellable and the less potential cost of maintenance, except the northern crossings of the Snake and the Weary Rivers, which could be difficult to maintain and could be more prone to ice problems. The southern route Is more apt to parallel a future road and will easily serve the projected boat facility. 15 SECTION IV A. Recommendations General: It Is clear from the results of this study what the most economical means of transmission of electrical energy to Manokotak Is - a cable or a SWGR system from the NEC's line near Kanakanak. Whether the route should be from this point via the southern route, or via the northern route would depend on future considerations as to the probability of a malntenance road and the Importance of serving a boat launch, etc.- Whether It Is potentially or electrically feasible to connect to NEC's line at this point Is not Included in the scope of this study. Cable Is the least expensive and potentially very rellable. More detailed voltage calculations should be made, and if results show they are within the necessary parameters, then cable should be considered the primary means of power supply to Manokotak Helghts. SWGR has been tried In one other case In Alaska. Although electrically there were no problems, there were problems with the A frame structural design. There is no technical reason that with proper structures that a SWGR cannot serve a remote, lightly loaded village like Manokotak In a very reliable manner. It Is recommended that strong considerations be given to the unique characteristics of Alaska and this services requirements, which Includes the low probability of intermediate Interconnections and also consider SWGR for this application. If SWGR is not to be used, the third most economical system Is a single phase line operating at 14.4 kv to ground. It Is recommended that the 7#10 or 3#7 Alumaweld conductor sizes be considered for SWGR and 3#8 A.W. conductor sizes for the single phase 14.4 kv line. Calculations should be made of NEC's system to determine if it can support Manokotak's minor load near Kanakanak. It Is expected that It wlll be able to. Since Manokotak's load wil] strongly approximate the characteristics of the local loads, shifting a few Intermediate transformer connections can balance phases. Reclosers and _ coordinated fuses will reduce’ the Probability of failure to the NEC's system to a very low value; therefore, there is no strong reason to cast this alternative out for these reliability reasons. Therefore, It Is recommended that Interconnection at this location be pursued. It Is also recommended that If a transmission system Is used, that an emergency generator be retained for standby use at Manokotak as system maintenance can be difficult during some times of the year. The current 300 kw emergency generator has the single phase capacity to easIly handle Manokotak's present demand. If It Is decided to construct this system, the designs should consider bid alternatives for the cable system and both 16 types of overhead structures, deep burial and piles. Some contractors would propose to excavate for deep burial with a backhoe. One problem with this Is that proper compaction of backfill will be extremely difficult to achleve. A contractor might be able to provide adequate pole burial depths In this soft matertal with down force, on a clamp, from a vibrating pile driver. Unfortunately, on these small Jobs, contractors can Ilittle afford research and development to determine a more efficient construction method. Further, after development of such a method, another contractor will utilize it on the next job. Thus, there Is no economic Incentive for such development and costs always remain high. It Is recommended that the State explore and finance methods of Introducing Innovation In design and construction of transmission for generic problems of this type. 17 DOLLARS: (Thousends) DOLLARS (Thousends) ROUTE A Construction Cost + Losses POLES STRAPPED TO 20’ PLES 700 e80 e680 eo 420 @00 660 660 640 620 600 480 460 440 420 400 360 360 1 1/o 2/0 3/o 4/0 7g100— 711 7H12 347 348 CONDUCTOR O 7.2 kv 1g 014.4 kv 1p x 22.0 kv 196 + 7.2 kv 36 O14.4 kv 39 ROUTE B- Construction Cost + Losses POLES STRAPPED TO 20’ PLES @20 600 §60 860 §40 620 §00 480 460 440 420 400 380 3%60 xO 320 1 1/0 2/o 3/0 4/0 -7#10s 714 7HIZ Ss 3GT 3¥8 ROUTE C_ Construction Cost + Losses POLES STRAPPED TO 20° PLES 7912347 348 7911 7#10 4/o CONDUCTOR 2/fo 3/0 18 x 22.0 kv 16 30 O14.4 kv 414.4 kv 712 HT 3#8 7911 || 7H10 4/o CONDUCTOR POLES STRAPPED TO 20’ PLES 2/fo 3/0 ROUTE D- Construction Cost + Losses 1/o A 8288 ene (spuosnouwL) suvnoa COLLARS (Mousonde) ROUTE A Construction Cost + Losses 700 80 @60 640 @20 @00 §80 560 640 620 600 480 460 440 420 400 t ° 1 1/o 2/0 3/o 4/0 = 7$10s7Bti so 7gt2s3GT? 348 CONDUCTOR O 7.2 kv 16 O14.4 kv 16 x 22.0 kv 18 + 7.2 kv 36 414.4 kv 36 ROUTE B- Construction Cost + Losses 620 €00 §@0 660 640 620 §00 460 460 440 420 400 - 380 360 1 1fo 2/0 3/0 4/0 7H10s7pt ss 7H1D_s3GT 348 (Teveende) SSSESEERSEE SE SE (TMoueande) ‘ROUTE C Construction Cost + Losses 760 740 720 Joo @s0 e680 eo 4@20 @00 680 660 840 620 600 480 460 440 420 1 1/o 2/o 3/o 4/0 7g10 7H THi2 347 3gs8 CONDUCTOR O7.2 kv 16 O14.4 kv 16 x 22.0 kv 196 + 7.2 kv 36 414.4 kv 36 ROUTE D- Construction Cost + Losses 1 1/o 2/0 3/0 4/0 7#10ss7pi— 71D ST 3s CONDUCTOR ROUTE A_ Losses OVER PROJECT UFE DOLLARS (TMovueande) 1 1/o 2/0 3/o 4/0 = 7H10—ss7H1 (HID s3GT age CONDUCTOR 07.2 kv 16 O14.4 kv 16 x 22.0 kv 16 + 7.2 kv 36 O14.4 kv 36 ROUTE B- Losses OVER PROJECT LIFE DOLLARS (Thoveands) 1 1/0 2/o 3/o 4/0 = 7H10s7HI 71D GTB CONDUCTOR ROUTE C_ Losses OVER PROJECT UFE = 140 é 130 120 110 100 90 |: 70 12 60 40 30 20 10 o 1 1/o 2/0 3/o 4/0 7#10 0 7gtt 7H12 347 3g8 CONDUCTOR 0 7.2 kv 16 2 14.4 kv 19 x 22.0 kv 19 + 7.2 kv 39 414.4 kv 36 ROUTE D- Losses OVER PROJECT UFE 110 100 DOLLARS (Thousende) 8 6 8&8 § 8 8 8 8 1 1/o 2/o 3/o 4/0 #1071 7HID_—s3GT 348 DOLLARS (Thousende) (Thoueende) ROUTE A Construction Cost 1 fo 2/0 3/0 4/0 710 «71d | O7pI2 Oe? OSS CONDUCTOR O7.2 kv 19 14.4 kv 16 x 22.0 kv 18 + 7.2 kv 36 414.4 kv 39 ROUTE B- Construction Cost POLES STRAPPED TO 20’ PLES 620 @0 660 660 s40 620 $00 480 460 44 420 400 380 30 sO m0 1 1/o 2/o 3/o 4/o = 710s 711 i 7IDT. see CONDUCTOR DOLLARS (Thousende) (Mousende) ROUTE CC Construction Cost POLES STRAPPED TO 20° PLES @00 760 700 0 @00 §60 g00 460 400 360 1 1/o 2/o 3/o 4/0 7g10 7#11 7912 347 38 CONDUCTOR O 7.2 kv 16 14.4 kv 1g x 22.0 kv 19 + 7.2 kv 36 414.4 kv 36 ROUTE D- Construction Cost POLES STRAPPED TO 20' PLES e680 40 @20 @00 80 660 640 : 600 480 460 440 420 400 380 380 so 320 1 1/o 2/0 3/o 4/o —-7H10s7Btt 71237 3g COLLARS (TMeoveende) DOLLARS (TMovusends) Pe tte ROUTE A Construction Cost 700 20 eso e410 @20 600 880 660 640 20 600 460 460. 440 420 400 ‘legs 1 1/0 2/o 3/o 4/o 7$10002 7g 7#12 347 398 CONDUCTOR O7.2 kv 16 O14.4 kv 18 x 22.0 kv 16 + 7.2 kv 39 414.4 kv 36 ROUTE B_~ Construction Cost 1 1/o 2/o 3/o 4/0 = 710s 7B TBD ST age (Thousende) (Mousends) EESSSESESER EES EB ROUTE C Construction Cost fo 2/0 3/0 4fo CONDUCTOR 7$10 7#10 7911 7911 7p12 7912 7 OH8 x 22.0 kv 16 78 Filename: CABLE Factors: Overhead= Conting. = Profit= Multiplier Wages: Operator= Lineman= Laborer= Operation: Clearing & Staking= Turf Ripping= Cable Spotting= Cable Laying= River-X= Machines: D-6= Sno Mach= Hoe= Shack= Sled= Misc. River-X Material: Freight= Cable= Trans. Recieving= Switching= Volt. Regulator= 1 Ph Sectionalizer= Route: D Miles: Total= Clearing= "Wet"= "Dry"= Clearing Conductor Staking 1/0 17820 25. 00% 22. @@% 10. 00% 1.65 $55 $55 $55 $600 $240 $240 $240 $11,100 $65. 00 $9.12 $4,030 $5,720 $5, 000 $2, 000 $3,000 $9.13 $900 $5, 227 $7,183 $4,183 $5,183 $6,548 18.00 4.80 16.50 1.50 River-X 23265 NOTE: Losses assumed a little Total: (Construction Daily Wor Time: /hour /hour /hour Total Time (hr) /mile n/a /hour 25. 80 /hour 48.60 /hour 25. 80 total 2 weeks /hour work /hour standby 2 for 1 month 1 for 1 week 1 for 1 month 1 for 1 month 2 weeks 4/100# 40, 000# mini 41000’ Weight= /mile total Weight= total Weight= total Weight= total Weight= River-X: 1 Phase Misc. Cable Machines 233022 27637.5 graeter than 1/02 ov + Losses)= $321,744 26-Jun-86 k @.83 Hr/Hr (S@min/hr Labor) Work Return Travel Travel (mph) (mph) n/a n/a 1 3 4 4 1 3 (local rental) (local rental) (local rental) (local rental) (local rental) (local rental) (local rental) mum 5200 #/mile 2000 # 2000 # 2000 # 1000 # B Snake= 1 7.2 KV Construction Total $301,744 erhead or : $20,000 Filename: ATOTPILE $ Total Cost of Route A (Piles) Construction Cost + Losses Routes Miles: Conductor 1 1/8 2/8 3/8 4/@ 7#12 7#1i1 7#1e 387 348 $ Total Cost of Route B (Piles) Construction Costs + Route: Miles: Conductor 1 1/2 2/8 3/2 4/8 7#1 7#11 7#i2 387 348 a Total= Clearing= Wet= Dry= KV ” Phase B Total= Clearing= Wet= Dry= KV Phase 18.08 4.88 16.50 1.58 7.2 1 492416 492092 506282 510035 521722 515880 534527 551197 523017 531046 15. 08 2.88 13.50 1.50 7 1 440596 440322 452141 455262 464995 460112 475776 489948 466183 473033 miles miles miles miles 3 630638 624311 642631 663398 691175 587906 576046 584519 578711 568117 miles miles miles miles 3 559091 553815 569078 586377 609516 523418 513662 S20969 515881 507178 River-X:s 14.4 1 477394 488070 496623 52579 515779 461956 467584 467099 462244 454581 River-Xs 14 1 428077 430303 444092 449849 460043 415175 419990 419866 415539 409312 Weary= Snake= Snake= 3 634165 628291 647169 668184 695969 574327 558191 561257 562935 547278 Losses Weary= Snake= Snake= 3 562036 557132 572859 598365 613511 512102 498782 501584 502734 489806 18-Jun-86 22 1 393628 386016 388762 392846 395854 361323 366754 375516 363284 366045 22 1 358111 351768 354854 357462 359965 331198 335749 343257 332858 335206 % Total Cost of Route C (Piles) Construction Cost + Losses Routes: Miles: Conductor 1 1/8 2/8 3/8 4/8 7#10 7#il 7#12 347 348 c Total= 28. 5 Clearing= 5.20 Wet= 19. 80 Dry= 1.58 KV 7 Phase 1 531001 538635 546801 551081 564395 557755 578176 595294 S65@69 573149 miles miles miles miles 3 685179 677998 698858 722515 754157 636579 622238 630243 625274 612377 River-Xs 14 1 513893 516943 535801 542589 557626 496342 501936 499516 495855 486064 $ Total Cost of Route D (Piles) Construction Cost Route: Miles: Conductor 1 1/@ 2/8 3/8 4/0 7#10 7#11 7#12 3#7 348 D Total= 16.50 Clearing= 2.20 Wet= 15. @@ Dry= 1.50 KV 7 Phase 1 461927 461608 474613 478250 488760 483397 499841 513628 489290 495799 miles miles miles miles 3 589793 583996 602787 619820 645278 550595 539859 545518 541501 531125 River-X:s 14 1 448137 450588 465759 471215 483312 433967 438477 436538 433581 425785 Weary= Snake= B Snake= 3 689204 682523 704026 727966 759617 621114 681903 683750 687307 588635 + Losses Weary= Snake= B Snake= 3 593033 587644 604947 624207 649673 538147 S22692 524186 527048 512016 “es 2e 1 422227 413558 416683 421337 424762 ~ 385435 391398 399963 387439 390258 “e090 22 1 374870 367893 378428 374154 376911 345258 358051 356951 346870 349139 Filename: ATOTPOLE % Total Cost of Route A (Poles) Construction Cost + Losses Route: Miles: Conductor 1 1/8 2/0 3/8 4/8 7#10 7#11 7#12 387 348 A Total= Clearing= Wet= Dry= KV Phase 18.02 4.88 16.50 1.52 7.2 1 553973 551479 564773 564823 573218 557838 58@391 599543 568050 578579 miles miles miles miles 3 672520 655932 664192 672224 683625 572396 567838 591151 571063 562178 River-Xs 14.4 1 538954 539468 555117 557378 567272 503916 513451 515448 587279 494117 $ Total Cost of Route B (Poles) Construction Cost Route: Miles: Conductor i 1/8 2/8 3/8 4/8 7#18 7#i1 7#12 347 348 B Total= Clearing= Wet= Dry= KV Phase 15.02 2.8 13.52 1.52 7 1 495028 492845 503763 503632 510468 497214 516308 532755 S5e@5986 507358 miles miles miles miles 3 593378 579589 586488 593205 682735 510192 506492 526134 5@9185 501043 River-Xs 14 1 478839 479274 492342 494242 5@2512 449775 457815 459724 452677 440838 Weary Snake= B Snake= 3 676049 659906 668724 677004 688413 558812 549977 567883 555281 541325 + Losses Weary= Snake= B Snake= 3 596319 582901 598265 597189 686725 498878 491608 5@6744 496033 483666 18-Jun-86 1 1 @ 22 1 468454 454504 456823 458348 456660 404581 414347 428284 489799 410441 22 1 419951 408366 410333 411612 410248 366935 375880 386869 371297 371018 $ Total Cost of Route C (Poles) Construction Cost + Losses Routes Miles: Conductor 1 1/@ 2/0 3/8 4/2 7#18 7#1i1 7#12 347 3#8 c Total= 2a. 5 Clearing= 5.20 Wet= 19. 82 Dry= 1.58 KV 7 Phase 1 601048 598196 613319 613358 622893 685338 632732 654444 618673 622026 miles miles miles miles 3 732896 713974 723369 732497 745457 618658 615192 642244 618861 609426 River-Xs 14 1 583943 584508 602322 604869 616128 543927 556495 558669 549462 534944 % Total Cost of Route D (Poles) Construction Cost Route: Miles: Conductor 1 1/8 2/0 3/8 4/2 7#10 7#i1 7#12 347 348 D Total= 16.50 Clearing= 2.20 Wet= 15. @@ Dry= 1.50 KV 7 Phase 1 See455 520018 531972 531778 539237 524506 547289 565394 535921 537731 miles miles miles miles 3 627373 612184 619764 627139 637604 535717 533398 555555 536356 527913 River-Xs 14 1 583789 5042608 518623 520699 529784 471739 482314 484371 476659 463985 Weary= Snake= B Snake= 3 736914 718501 728530 737941 750910 603187 594851 615745 620887 585677 + Losses Weary= Snake= B Snake= 3 630608 615828 623918 631520 641993 S23265 517025 534227 521890 508798 -es 22 1 507367 491446 494058 495772 493835 434445 447826 464025 442641 444599 “ee ee 1 442695 429928 432071 433469 431943 384251 395471 408804 391306 392034 $ Cost Losses on Route A over Route: Miles: Conductor 1 1/8 2/8 3/8 4/8 7#18 7#11 7#1e 347 3H8 % Cost Losses Route: Miles: Conductor i 1/8 2/2 3/8 4/8 7#18 7#il 7#12 347 348 A Total= Clearing= Wet= Dry= KV Phase B Total= Clearing= Wet= Dry= KV Phase 18.8 4.80 16.50 1.52 7.2 1 23365 19258 15941 12828 1@653 74172 91717 114810 83451 104497 on Route B over 15. aa 2.82 13.50 1.5@ 7 1 19471 16248 13285 10692 8877 61818 76431 95675 69543 87081 project life miles River-X3s Weary= miles Snake= miles B Snake= miles 14.4 3 1 3 6855 5841 1714 5435 4814 1359 4321 3985 1080 3428 3207 857 2724 2663 681 23748 18543 5937 29949 2e929 7487 37753 28703 9438 27854 20863 6763 34154 26124 8538 project life miles River-X: Weary= miles Snake= miles B Snake= miles 14 3 1 3 5713 4868 1428 4529 4012 1132 3621 3321 900 2856 2672 714 2270 2219 567 19798 15453 4948 24957 19108 6239 31461 23919 7865 22545 17386 5636 28461 21778 7115 2021 1604 1276 1014 807 6988 8810 1115 7959 10047 1684 1336 1064 845 672 5823 7342 9254 6633 8372 % Cost Losses on Route C over Routes Miles: Conductor 1 1/8 2/2 3/8 4/2 7#18 7411 7#1ie 347 348 c Total= Clearing= Wet= Dry= KV Phase 20. 50 5.20 19. 0@ 1.52 7 1 26618 21933 18156 14610 12132 84474 104455 130756 95042 119810 % Cost Losses on Route D over Route: Miles: Conductor 1 1/8 2/0 3/8 4/2 7#10 7H#11 7eie 347 348 D Total= Clearing= Wet= Dry= KV Phase 16.52 2.20 15.00 1.50 7 1 21418 17653 14613 11759 9765 @ 67991 84074 105243 76497 95789 project life miles River-Xs miles miles miles 14 3 1 7807 6653 6190 5483 4921 4539 3904 3652 3102 3833 27047 21118 34108 26114 42996 32689 30811 23762 38897 29753 project life miles River-Xe miles miles miles 14 3 1 6284 5355 4982 4413 3961 3653 3142 2948 2497 2441 @ @ 21769 16998 27453 21018 34687 26311 24799 19124 31307 23947 Weary= Snake= B Snake= i952 1548 1230 976 776 6762 8527 10749 7783 9724 Weary= Snake= B Snake= 1571 1246 992 785 624 5442 6863 8652 6200 7827 “eo 2302 1827 1454 1154 919 7958 10034 12647 9265 11442 “ese 1853 1478 1178 9e9 739 6485 8276 10179 7296 9209 $ Total Construction Cost of Route A (Piles) Routes Miles: Conductor 1 1/8 2/8 3/8 4/8 7H1D 7#11 7#el2 347 38 A Total= Clearing= Wet= Dry= KV Phase 18.08 4.88 16.58 1.52 7.2 1 469051 472834 498348 497207 511069 441788 442810 436387 439566 426549 miles miles miles miles 3 623775 618876 638312 659971 688452 564158 546097 546766 551657 533964 River-Xs 14.4 1 471553 475255 492638 499372 513115 443413 444655 438397 441381 428456 $ Total Construction Cost of Route B (Piles) Routes Miles: Conductor 1 1/@ 2/8 3/8 4/8 7#12 7#H#i1 7#e12 347 3#8 B Total= Clearing= Wet= Dry= KV Phase 15.00 2.82 13.52 1.50 7 1 421125 424273 438856 444572 456118 398301 399345 394272 396642 385952 miles miles miles miles 3 553378 549286 565477 583521 607247 503628 4887085 489528 493336 478717 River-Xs 14 1 423218 426291 440771 446376 457824 399722 480882 395947 398153 387542 Weary= Snake= Snake= 3 632451 626932 646089 667327 695288 568398 552704 551818 556172 338732 Weary= Snake= Snake= 3 560608 556000 571959 589651 612944 5@7155 492543 493719 4970398 482699 orm 22 1 391606 384412 387484 391833 395047 354335 357943 364412 355325 355998 22 1 356426 350431 352992 356615 359293 325367 328407 334803 326225 326834 $ Total Construction Cost of Route C (Piles) Route: Miles: Conductor “1 1/8 2/8 3/8 4/8 7#18 7#11 7#12 347 348 c Total= 20. 50 Clearing= 5.20 Wet= 19. 88 Dry= 1.52 KV 7 Phase 1 504391 58873 528645 536471 552263 473282 473721 464538 470028 454139 miles miles miles miles 3 677372 671880 693937 718611 751855 609532 588130 587247 594463 573488 River-Xs 14 1 507240 511462 531262 538937 554593 475223 475822 466827 472095 456311 $ Total Construction Cost of Route D (Piles) Routes Miles: Conductor 1 1/8 2/8 3/8 4/8 7H#18 7#i1 7#12 347 3#8 D Total= 16.52 Clearing= 2.20 Wet= 15. @@ Dry= 1.58 KV 7 Phase 1 440489 443955 462000 466291 478995 415406 415767 488385 412793 482010 miles miles miles miles 3 583589 579013 596826 616678 642762 528825 511606 518983 516782 499818 River-Xs 14 1 442783 446174 462106 468276 480871 416969 417459 410227 414457 401758 Weary= Snake= Snake= 3 687253 688975 702796 726998 758841 614352 593376 593001 5996084 578911 Weary= Snake= Snake= 3 591462 586399 603956 623422 649049 532785 515828 515535 52084a 504189 -oe9s 22 1 419925 411731 4152e9 420183 423843 377477 381356 387316 378374 378816 “es 22 1 373018 366423 369238 373225 376171 338853 341975 346772 339574 339938 $ Total Construction Cost of Route A ( buried poles ) Route: A Miles: Total= 18.82 miles River-Xs Weary= i Clearing= 4.82 miles Bnake= 1 Wet= 16.50 miles B Snake= @ Dry= 1.50 miles KV 7.2 14.4 22 Phase * 3 1 3 1 Conductor 1 530688 665665 533113 674335 466433 1/2 532221 650496 534645 658547 452901 2/2 548831 659878 551132 667644 455547 3/8 551995 668797 554163 676147 457326 4/0 562558 680901 564607 - 687732 £455853 7#10 483666 548648 485373 552874 397593 7#i11 488674 537889 490522 542490 405536 7#12 484733 553398 486745 558445 417188 347 484598 544009 486416 548518 401839 348 466082 5280e4 467993 532787 480395 $ Total Construction Cost of Route B ( buried poles ) Route: B Miles: Total= 15.@@ miles River-Xs Weary= i Clearing= 2.82 miles Snake= 1 Wet= 13.5@ miles B Snake= @ Dry= 1.5@ miles KV 7.2 14.4 22 Phase 1 3 1 3 1 Conductor 1 475557 587665 473971 594890 418266 1/8 476797 575860 475262 581769 487832 2/0 490478 582887 489021 589365 489269 3/8 492942 598349 491578 596475 418768 4/@ 501591 600465 580293 606158 409568 7#18 435404 498400 434322 493922 361112 7#i1 439878 481535 438707 485368 367738 7#12 437280 494674 435805 498879 377615 347 436443 486640 435291 498397 364664 3#8 420277 472582 419867 476551 362646 % Total Construction Cost of Route C ( buried poles ) Route: C Miles: Total= 20.50 miles River-Xs Weary= @ Clearing= 5.22 miles Snake= @ Wet= 19.00 miles B Snake= 1 Dry= 1.52 miles KV 7.2 14.4 22 Phase 1 3 1 3 1 Conductor 1 574437 = 725088 577298 734963 S565 1/2 576264 707784 579824 716953 489619 2/8 595164 718447 597783 727300 492604 3/8 598748 728594 601217 736965 494617 4/8 610761 742355 613095 750134 492917 7#18 520864 591612 522809 596425 426487 7Hil 528277 581084 530381 586324 437792 7#12 523688 599248 52598 604996 451377 347 523631 588e5e@ 525702 593184 433576 3#8 5@3016 5708529 505191 575953 433157 $ Total Construction Cost of Route D ( buried poles ) Route: D Miles: Total= 16.52 miles River-X: Weary= @ Clearing= 2.20 miles Snake= @ Wet= 15.@@ miles B Snake= i Dry= 1.5@ miles KV 7.2 14.4 22 Phase 1 3 1 3 1 Conductor 1 501837 621089 498435 629037 440843 1/8 582365 687202 499847 614582 428458 2/8 517359 615803 514969 622928 430901 3/2 520011 623997 517759 630735 432548 4/8 529472 635187 527343 641369 431203 7H#12 456515 513948 454741 517822 377846 7#i1i 463215 5e@5945 461296 510162 387395 7#12 460151 520949 458260 525575 398625 3#7 459424 511557 457535 515690 384018 348 441942 496606 439957 500971 382824 ORLG MANOKOTAK TRANSMISSION LINE SéO/(L3 LOGS &. Eluis G-3-8¢ i-2 MANO KOTAK TRANSMISSION LINE Sots LOGD Priority A TUNDrw —-—— FRost tine 2 PT Pear 4 — — — Bot. FRosr o OL OG. Now PLAST. sicT VAY Low UNIT wT. Parrcaity #( #2, #9 o SWAMP Geass & Ih! 2 ML, Gray douPeasr: Stet 4 ‘ 5 6 Parioaity #3 °' SWAMP GRASS 2 ML Sir same *1 4 (NON PLAST.) a ‘' ML “Cuayer Sur Samp. #2 E. Eccts LocaTED oN East Sipe oF RoAD MILE PosT S&S BETWEEN DILLINGHAM 4@€ NELSoN vVICLE low meadow lke depression, Now Plastic Silt Exposed 10 TELEPHONE CHALE TRENCH oN WEST s(DE of Rear. Suake RWER Bank TIDE RISES to within * [' SORFACE. OF JIANOKOTAK TRANMISSION Me. LINE E. Eis Sat > Logs HicctroP o GRASSES , SECGES, BRUSH lLecateo oN Low (so't) 2 HILL w/ STUNTED BiRcH ML Gia Now Plasr. Sur AND 30'~4o' SpaucEe 4 « Sauo - BLAck APPERZS re ML Sanoy Ser Samp. *3 BE FIRST INOICATTOI OF a (Nom PLAST.) WeArnereo Reck PRioaitTY #6 ,a> > MUSKEG Locatep iw LAKE AREA 2 pr RETWEEN WEARY 2 SNAKE yw QiVERS - 1 x § ML GRAY SILT (Nd ROAST.) 6 Peionitr 48 TUNDAA -——> FReSt LINE PT PEAT —— - Fost LINE ML GRAY Mou PLAST SILT Genege Note 2 Ace Rwen Banes Lookeo APPeLOx SAME — GRASS ORL TUNDRA OVER GAY SILT, No DEEP Deposits oF PEAT VISIBLE IN RIVER BANKS. ros 2 Field Ie. She (Helscopter or Float plame” O = Frel& Lrveshg chon Stes (Helicopter) : = Field Site Des cripten Cor Log) eee MATERIALS RECONNAISSANCE FAS 411 to Kanakanak Mile 3.6 to 6.1 Project S-0411(4) S. STATE OF ALASKA . DEPARTMENT OF EIGHITAYS WESTERN DISTRICT MATERIALS SECTION ENGINEERING GHOLOGY BRANCH 4 > STATE OF ALASKA’ 22 PEAS OF HIGHWAYS (a (2. Materials Recoana..s: Project S-0411(4) INTRODUCTION This report contains the centerline soils and material site reconnaissa of TAS 41) Spur to Nanakanak. The reconnaissance was initiated August 6 and completed August 19, 1968, by Engineering Geologist, J. G. Moores. Hoke) On September 14, 1965, seven test holes vere placed at ayprexinately one half wile intervals elong the Kanakanak Spur while prespeeting for gravel on the Dillingha nagik project. S s analyses of samples taken at that time vere verforiued by the Anchorage District Materials Laborat Two previous materials reports entitled: Mates Re , Aleknagik, August 1967 and Surnlenmer han-Aleknogik January 1968, contain information pertinent to the Manekanak Spur. ’ al Mate LOCATION AMD ACCESS This project is located in southwestern Alaska, north of Bristol Bay, at the head of Nushagak Bay. The Kanakanak Spur begins at Mile 3.6 on the Dillingham-Aleknagik highway ard terminates at Mile 6.1 at Kanakanak Hospital. Since this is a remote project which is not connected directly to the Alaska Highway System, heavy equipment will most likely have to be trans- ported to Dillingham by airplane, ship, or sea going barge. The period of normal shipping activity for this area is between April and September. METHOD OF INVESTIGATION The test holes placed along the Kanakanak Spur during the preli materials investigation of the Dill irery gham Aleknagik project were cugeread mates z by means of a track mounted Mebile Drill utilizing a 6 inch di ti ous flight auser. Additional field yo ners oe SEANCES CONS! Stee. -5 to dateyz al (peat), ond id aU: tes. ALL of the above information is incluc axa brous organic in potential nater this report. of the Manakanak Spur is ly slopes to a east tevare the Rust depressions coutain des organi a3 ereeks. Generally the water table at or within a few feat of the ural ground surface. Several of the ridges adjacent to the muskegs. Borings in that cilt, up to 18 feet thickness, mantles the length of the vroject. Testing indicates that the natural. moisture of the silt is higher than the licuid limit. Tt is ce-- sidered unstable and is generally very difficult to work. Vegetation o most of the high ground and in nearly 211 ef the depressions consists of mosses. The high ground also contains scattered stands of sma with thick brush. Nearly fc rm gs drai contain springs at their eat er 2. Project 5-0411(4) MATERIAL SITES With winor exception, most of the material used to construct the KRanel-anak Spur came frem the vicinity of Scuaw Creek. Material for maintenance of this road is currently obtained from M.S. 411-015-1 which is located right of the Dillingham Aleknagik Road, one mile northwest of the Kanakanck aad Aleknagik Lake Road Junction, An abandoned borrow source is located right of the alignment at Mile 4.35. This source has never been used as 2 maint- enance source since the overburden exceeds 6 feet in thickness. The deep fill across Bradford Creek in the vieinity of Mile 6.0 was constructed with silt excavated from Kanakanal: Will and Nospital Hill, left of the aligmaent at the beginning and end of the £311. The above informaticr vas provided by Dillingham Maintenance Supervisor, Mr. William M, Tenneyson. Previous exploration for material sources, and recent hand augering and probing indicate that material suitable for borrow may be found in sui cient quantity to meet the recuirements of this project in the folloving locations: - 1. The abandoned material source located right of the Kanakanak Spur at Mile 4.35. 2. The ridge between the forks of Squaw Creck 1/8 of a mile northeast of M.S. 411-015-1. 3. Within M.S. 411-018-1 north of Area "A", It is anticipated that the overburden may be as deep as 11 feet, 4. Gravel is exposed in the ridge across Scuaw Creek east of N.S, 41]-018-1. This area was not investigated in the past because of multiple oimership. 5. Gravel also occurs on the Henry Shade proyerty northwest of M.S. 411-016- 1; however, the haul distance to the beginning of the Kanakanal: Spur vould be about 2.5 miles. CENTERLINE SOILS DESCRIPTION (Referenced by Mile Post) io duter ec: of the Dillons, . 1.69 also ceincides -; a soject. Mile 0,00 bests This pooject 2 e 3.60 at Aleknagik Read and the to Kanakanak. 1 Lo Station 151150 of the Dillingham Aleknag in Dillingham. ME me A cecoanaissance of the in place culv de in the accompaninent shan Maintenance Supervisor, information on the culverts reflects tir. several years maintenance experience. ALJ of th: the Following sections were augered to a depth °° 13 feet. pproximately 35 years ago ty the existing gravel 3 the spring the road The existing road to Kanakanak was constructed : and was corduroyed throughout its length. Gene overlay is twe feet or less in thickness, Durin breaks up at several locations. Mile 3.60 (B.0.P.) to Mile 4.01 This section consists of tvo silt rieges separac.d 3: a shortmediun suskeg segment. The first silt ridge, Mile 3.60 (i,0.P.) to Mile 3.30 censists of brow silt. Test hole 35, placed in th: vicinity of Mile oo =~ Project $-0411(4) indicates that the brow silt (A-4, 74) is underlajn by a brown pebbly silt (A-4, F4), The water table was encountercd at a depth of 9 feet. The muskeg segment, Mile 3.80 to Mile 3,84, is approximately 200 feet in Jength and has a im depth of about 16 feet, Probing indicates that the living suxficial mosses are underlain by fibrous peat interbedded with silt lenses. This’ muskeg is drained by the cast fork of Bartman Creek. An 18 inch culvert is lecated undor the existing prism and has been adecucte. The thickness of the fibrous ozganic material and intexbedded silt vari between 13 avd 16 feet, es The remaining segment, Mile 3.84 to Mile 4.9], consists of a long silt ridge. One test hole (418) was placed in the vicinity of Mile 4.00. This boring indicates that the ridge consists of brow: silt (A-4, F4) over brown pebbly silt (4-4, F4), The water table was encountered at a depth of 15 feet, ; Mile 4.01 to Mile 4.35 This section begins in a short deep muskeg segment and ends in a long silt ridge. The ruskeg segment, Mile 4.01 to Mile 4.10, is approximately 425 feet in length and has a maximum depth of about 27 feet. The living sur- ficial mosses are underlain by fibrous peat interbedded with silt lenses. This muskeg is drained by the west fork of Bartman Creek, Three culverts (one 24 inches and two 36 inches in diameter) drain the muskeg right of the alignment and would be adequate if drainage left of the alignment were improved, Probings indicate that the fibrous organic material (living surficial mosses and underlying peat) and interbedded silt average 26 feet in thick- ness. A spring occurs right of the alignment 159 feet ahead of Mile 4.99 silt ridge. This spring bas been a source of notable cad in the long silt ridge, Mile 4.19 to Mile 4.25 : 4.25. Tris boring (419) indicates that thi dse lt (A-4, F4) over brown vebbly silt (A-4, F4). necuntered at a depth of six fect. j rand decrest muiskey segnent encounrt on this project an: s ina long rollin; silt ridge, The muskeg so Mile 4.35 to ifile 4.59, is approximately 6990 feet in length with a maximum denth of about 31 fect. The living mosses ave underlain by fibrous peat interbedded with silt lenses. This muskeg is drained by Kloudike Creek, Three culverts (one 69 inches ard tvo 18 inches in diameter) drain the muskeg right of the alignment and anveay te be adequate. the long: Probings indicate thet the fibrous organic material aud interbedded silt average 29 feet in thickness. A spriny occurs right of the alignment 1090 feet ahead of Mile 4.35 at the base of the silt ridge. This spring ts a Cc -4- 2. Project S-0411(4) : source of potable water and is currently in use. At one time a wood struc- ture bridged Klondike Creek, Three bents of 4 piles each, 35 fect in length, were placed at the creck crossing. During the driving of the piling one pile dropped 33 feet with only one blow of the hatmer. Onc test hole was placed in the long rolling silt ridge, Mile 4.50 to Mile 4.90, in the vicinity of Mile 4.90. This boring (420) indicates that the ridge consists of brown to grey silt (A-4, F4), The water table was en- countered six jnches below the natural ground surface. Side hill musteg sections containing fibrous organic material which varies between 2 and 6 feet in thickness occur left and right of the alignment for the fulJ length of this ridge. Mile 4.90 to Mile 5.95 : This section begins in a short muskeg segment and ends in a rolling silt ridge containing perched side hill muskeg segments separated by stands of thick brush. The muskeg segment, Mile 4.90 to Mile 4.95, is approximately 300 fect in length with a maximum depth of about 19} feet. The living mosses at the surface are underlain by fibrous peat interbedded with silt lenses. One 18 inch culvert drains the area right of the alignment and appears to be adequate. The living surficial mosses in the side hill mus- keg areas are underlain by 4 to 11 feet of fibrous peat. Probing indicates that the organic material is thicker right of the alignment. Three test holes have been placed in this section at Mile 5.20 (TH 421), 5.50 (TH 422), and 5.80 (TH 423). Testing indicates that the material in all three test holes consists of brow to grey silt (A-4, F4). The water table varied between 3 and 6 fect. An 18 inch culvert has been placed in the vicinity of Mile 5.30. Probings-off the ends of this culvert indicate the fibrous organic material is 18% to 19 feet in thickness. Mile 5.95 to Mile 6.10 (2.0.P.) This section begins in a deep fill across the muskeg drained by Bradford Creek and ends on Hospital Hill at Kanakanak. The muskeg segment, Mile 5.95 to Mile 6.01, is approximately 300 feet in length with a maximun depth of about 24 fect. In all of the other deep muskeg segments, probing indicated that the fibrous organic material was interbedded with silt lenses; however, the foundation material in this segment appears progress~ ively stiffer with depth. The existing fill has a maximum height of 15 from the bottem of the culvert. The embankment material in the fill consists generally of brown silt excavated back and ahead of the fill from the ridges left of the alignment. This fill has apparently not settled since it was constructed, The 72 inch culvert installed at BradfordCreek appears to be adequate. One auger boring (TH 424) has been placed on Uospital Hill left of the existing road in the vicinity of Mile 6.01. This test hole was placed in the area where material was excavated for the construction of the above fill. This boring indicates that the brown silt (A-4, F4) on Hospital Hill extends at least 18 feet in depth. The water table was encountered at a depth of 6 feet. C -5- Cc Project $-0411(4) CONCLUSIONS AND RECONMENDATIONS 1. The Annual Traffic Report put out by the Planning and Research Depart- ment for 1967 states that the Kanakanak Spur is utilized by 50 vehicles per day, This is also the same number of vehicles which utilize the Dillingham-Alecknagik Road between the Kanakanak Spur Junction and Lake Aleknagik, Although design data is incomplete at this time it is antici- pated that the’ design data will generally match that of the Dillingham- Aleknagik project. Therefore, the following Dillingham-Aleknagik Design Data will generally apply. Design Data ADT (1961) 75 Design Speed 40 mph ADT (1981) 175 Subgrade Width 28! DHV (1981) 35 Driving Lanes 2 T 5% Terrain Classification rolling Class E Category 2 Design Index 3 General Overlay Reauirements Frest Class Minimum Required Overlay NFS g" F-1 11" F-2 14" F-3 22" F-4 22" 2. Soil information on this spur indicates that most of the material along the alignment is silt with a high water table, Natural moisture samples of the silt were not taken during this investiczation. Generally the natural moistures taken of similar silt on the Dillingham-Aleknagik project exceeded the liquid limit, Therefore, it is recommended that deep cut sections in the silt be avoided. In those areas where design requirements will make silt cuts necessary, the silt will probably have to be wasted, 3. The existing original soil throughout the length of the Kanakanal: Sour consists of silt and muskeg. The silt has a frost classification of F4. Therefore, it is recemmended that the minimum overlay requirement for F4& material be set at 22 inches which is the same requirement for F4 material as determined on the Dillingham-Aleknagik project. A normal overlay method could be used on most muskeg areas with surcharging being recuired only at culvert locations. The minimum overlay thickness on the nuskeg should be at least 4 feet. 4. Anticipated consolidation for major muskeg areas has been estimated between 1 and 4 feet, based on the depth of the underlying organic material, > M.S. 411-016-1 . OKROIUN i Sigs SE a8 S, 411-015-1 ei Me M.S ‘ld ‘ -2i 4 Poe Mile 3.60 BsO.Po ~ Z («Gf 1H 920; . it , 4 | -———Mile 6,10 E.0.P. 3 —— omen cna ae Loe ee ee Grassy Island . : , | \ : ce \ i , “1 a . i VICINITY MAP , ‘s FAS 411 SPU ‘0 ‘" i KANAKANAK 1% ' Project No. Seil(h) 404% Scale 1" = 1 mile t ha i November 1968 say Role : ‘ms : c we Ltn TH:XX Test Hole No. Gravel Frost Zone Sondy Gravel Gravelly Sand Ice Lens Sand Field Sample Silty Sand Moisture Sample Silty Gravel & % Water Silty Sand Similar to FS:X Silty Gravel . Clayey Sand Frost Class Clayey Gravel Clayey Sand Depth in Feet Clayey Gravel Water Table Gravelly Silt Silt Silts NOTE :No water encountered except Clay Lie as indicated. Clay Organics , Organic Silt Bedrock Volcanic Ash Noted MATERIALS DESCRIPTION EXPLANATION gril = gravel peb = pebble wt = woter table i sa = sand bid = boulder bkn = broken si = silt grn = green rk = rock cl = clay bl = blue pt = peat gr = gray fib = fibrous “blk = black coo = coarse br = brown fi = fine y = yellow cob = cobble wh = white S-O4l1 (4) PROJECT NO. 38K z SN {REST Ha ~ . ~ Nae Wad iif JM ¢ sa gis TS regs \ TH 424 THA org/g/s/ 1 TH 42° tle 5 ~N% 689 es HWAYS MATERIALS SECTION TA L DEPARTMENT OF HIG Project Number S-Oll1 (4) Project Name FAS h11.Spur_to Kanakanak Mile a37_| [21/17/65 11/10/64 11/9/65 [12/9/65 | | 11-13 10-13 ear a RT 1 Aor eae rere ore f i ft BRE t ne ADDITIONAL EXPERTISE For larger projects our Alaskan staff is complemented by our parent com- panies in Scandinavia. With over 2500 professionals to draw from and nearly thirty years’ experience we can quickly mobilize a project team well suited for the tasks at hand. Our arctic and subarc- tic experience is thus extended into the following fields of activity: STRUCTURAL WORK ¢ roads and bridges * port facilities * buildings HYDROELECTRIC PLANNING AND ENGINEERING ¢ large scale projects ON AND OFFSHORE OIL AND GAS * exploration | ¢ development and production ¢ storage and transportation | ARCHITECTURE, CIVIL AND MINING | * geology * evaluation of resources © general design ¢ transport systems ZZ TRANSPORTATION PLANNING AND Ci ENGINEERING VoD Le * traffic planning ¢ heliports and runways TOURISM AND ECONOMIC PLANNING ‘ * population surveys and forecasts Tee \ © marketing economics WKS ZL . © tourism and recreational planning Z \ 93678 , inc. ult alaska polarcons PROJECT CODE DATE JUNE 86 DRAWN MD CHECKED QUADRANGLE LOCATION COMPLEX TERRAIN UNIT MAP DESCRIPTIONS |i 2El _ Scattered Loess over Moraine Peat is generally not present. Loess Mt - Tidal Flat Typically non-plastic silts that have a liquid Gn probably less than 5-10 feet thick over moraine limit lower than the natural moisture content. in most places. _Q _ Organics over Tide Flat The limited field observations El _ Loess over Till If peat is present it is probably less than 3 Mt made in this study revealed apparent peat Gt feet thick over loess. Loess generally ranges thicknesses of less than 5 feet over tidal from 5 - 15 feet thick over till. deposits in the extensive Snake - Weary river flats (Ausman/Ellis field trip-June, 1986). —?70___ Organics over Loess and Till Peat is generally 2 - 10 feet thick over loess It should be noted, however, that organic El+Gt and till. Alaska Dept. of Highways Materials occurrances in the Dillingham area of up to 31 Reconnaissance” indicates that peat up to 20 feet thigk are present in similar landscape feet deep might be expected in drainage bottans settings”. Therefore the possibility of and closed depressions. sigificantly thicker organic deposits throughout this unit should not be excluded. OtE]? _ Organics and Loess(?) Peat and loess(?) is generally 5 -15 feet thick Gt over Til] over till. The loess may also be redeposited a _ SHEET NUMBER or mixed in places with tidal deposits. 1) Alaska. Dept. of Highways (1968) Materials Reconnaissance. FAS 41] to Kanakanak. _Q _ Thick Organics over Till Peat is generally over 10 feet thick covering Mile 3.6 to 6.1. Project S-0411(4). Gt till. In the Dillingham - Kanakanak area peat up to 32 feet has been encountered’. 2) Alaska. Dept. of Highways (1967) Materials Report. Dillingham to Aleknagik. | Station 10+00 to 1142+42. Project Number i Os _ Strinc Fen over Till Peat is generally over 10 feet thick coverino S-0411(4). 7Gt till. String fens have standing water at the | surface. 2 MANOKOTAK TRANSMISSION LINE TFT 93678 Inc. SNAKE RIVER polarconsult alaska, 2735 EAST TUDOR ROAD e ANCHORAGE, ALASKA 99507 Y) - a _ sam —_ Y) = O O > © cc LU = LL e ep) rae © LLJ E ao O co < e ” co Lu Lu = So = Lu PROJECT CODE DATE JUNE 86 DRAWN MD CHECKED QUADRANGLE LOCATION | COMPLEX TERRAIN UNIT MAP DESCRIPTIONS 2EL _ Scattered Loess over Moraine Peat is generally not present. Loess Mt - Tidal Flat Typically non-plastic silts that have a liquid Gn probably less than 5-10 feet thick over moraine | limit lower than the natural moisture content, in most places, i | Pl -~O _ Organics over Tide (‘Flat The limited field observations ; El _ Loess over Till If peat is present it is probably less than 3 =~ asc made in this study revealed apparent peat cel ee Gt ge Bea feet thick over loess. Loess generally ranges : thicknesses of less than 5 feet over tidal i from 5 - 15 feet thick over till. | deposits in the extensive Snake - Weary river : ! flats (Ausnan/Ellis field trip-June, 1986) . —?0___ Organics over Loess and Till Peat is generally 2 - 10 feet thick over loess It should be noted, however, that organic E1+Gt and till. Alaska Dept. of Highways Materials i oceurrances in the Dillingham area of up to 31 Reconnaissance” indicates that peat up to 20 | feet thigk are present in similar landscape | feet deep might be expected in drainage bottans settings®. Therefore the possibility of | and closed depressions. Sigificantly thicker organic deposits throughout this unit should not be excluded. QtEl? _ Organics and Loess(?) Peat and loess(?) is generally 5 -15 feet thick | Gt over Till over till. The loess may also be redeposited ‘ | or mixed in places with tidal deposits. i | 1) Alaska. Dept. of Highway (1968) Materials Reconnaissance. FAS 41] to Kanakanak. _O _ Thick Organics over Till Peat is generally over 10 feet thick covering Mile 3.6 to 6.1. Project S-0411(4). I ?Gt till. In the Dillingham - Kana k area peat ‘= | i ip ko 25 fact aac betes anced’. 2) Alaska. Dept. of Highways (1967) Materials Report. Dillingham to Aleknagik. i Station 10+00 to 1142+42, Project Number Os _ String Fen over Till Peat is generally over 10 feet thick covering =| S-0411(4). é i- Gt till. String fens have standing water at the surface. : polarconsult alaska, inc. CONSULTING ENGINEERS AND PLANNERS 2735 EAST TUDOR ROAD ° SUITE 201 * ANCHORAGE, ALASKA 99507 (907) 561-1933 ¢ TELEX: 26708 PCA AHG