This is a digital document from the collections of the Wyoming Water Resources Data System (WRDS) Library.

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1 This is a digital document from the collections of the Wyoming Water Resources Data System (WRDS) Library. For additional information about this document and the document conversion process, please contact WRDS at wrds@uwyo.edu and include the phrase Digital Documents in your subject heading. To view other documents please visit the WRDS Library online at: Mailing Address: Water Resources Data System University of Wyoming, Dept E University Avenue Laramie, WY Physical Address: Wyoming Hall, Room 249 University of Wyoming Laramie, WY Phone: (307) Fax: (307) Funding for WRDS and the creation of this electronic document was provided by the Wyoming Water Development Commission (

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3 THAYNE WATER SUPPLY EXECUTIVE SUMMARY November, 1997 SUBMITTED TO > C ::J I en - -..J W > W..J WYOMING WATER DEVELOPMENT COMMISSION Prepared by FORSGREN ASSOCIATES, INC. 849 Front Street, Suite 201 Evanston, WY 82930

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5 SECTION 1.0 EXECUTIVE SUMMARY 1.1 PROJECT OVERVIEW The Town of Thayne is located in Lower (north) Star Valley, Wyoming near the Wyoming-Idaho border. As with most Star Valley communities, Thayne is situated in an area surrounded by exceptional natural beauty. This location makes the greater Thayne area particularly attractive for development and growth. Thayne is perhaps best known for the Star Valley Cheese factory located at the south end of town. The Thayne water system presently has 160 connections serving a population of about 300. In general, the Thayne water system is reported to be well maintained and in good condition. Much of the town's water piping has been constructed within the past ten years. Thayne's sole water supply source is the Flat Creek Springs located approximately 1 mile east of town. The town has a shared filing on these springs with the Star Valley Cheese factory. Both entities also share a single gravity feed line from the springs. The town's supply is directed to a booster pump station located adjacent to the cheese factory where the water is pumped to a 300,000 gallon steel tank (also located east of town). During most times of the year, the springs have adequate yield to meet the town's present demands. Thayne does, however, experience periodic water supply shortages during high demand periods and in the early spring (February March) when spring yields are historically at their lowest. Water rationing is periodically imposed. The Town of Thayne and Star Valley Cheese have shared water rights and facilities for many years. In 1947 and again in 1949, the two entities filed for water rights and were given appropriations from the Flat Creek drainage. A common transmission pipeline was constructed from Flat Creek Springs to the Star Valley cheese plant. In the 1980's, Thayne added distribution pipelines and a 300,000 gallon storage tank to better meet the needs of their residents. Existing system pressures typically range from 45 to 65 psi. During the summer months, system pressures drop as much as 20 psi, due to tank draw down, pipe losses, and/or supply shortages. The resulting low pressures, in our opinion, represent a serious health risk to the community. Wyoming DEQ regulations require a minimum of 35 psi working pressure at all points in the system during summer demand periods. Thayne's EPA compliance record is generally good. However, it is reported that the town relies on continuous chlorination to control bacteriologic growth in the water system. This is not a normal situation for a "true" spring that is properly developed. Of equal concern to the Town of Thayne is the lack of sufficient water to meet present and future demands. Summer-time rationing is a common event in Thayne. Water resources are a controlling factor in the economic growth of the community. This Level II study is largely in response to this concern. 1-1

6 1.2 PRESENT SERVICE AREA POPULATION A physical count of homes and businesses within the Thayne corporate boundaries revealed 91 homes, 23 mobile homes, 12 apartment units, 42 commercial businesses, 3 churches, 1 school, a cemetery, and the Star Valley Cheese Factory. The present population of Thayne is estimated to be 295 persons. 1.3 EXISTING SYSTEM DESCRIPTION The Town of Thayne receives it's water supply from the Flat Creek Springs located about 1 mile east of town. The water is delivered from the spring site to the town (and Star Valley Cheese) through a 10-inch transmission line. The town's water is then pumped directly to their water storage tank through a 6-inch PVC main where it is in tum delivered to the distribution system. Disinfection occurs immediately downstream of the pump station Water Supply Source The Town of Thayne (and Star Valley Cheese) is wholly dependent upon the Flat Creek Springs for their source of supply. These springs are located approximately one mile east of town. The spring was initially developed in 1948 with a single concrete collection box located about 20 feet from the bank of the Flat Creek "pond". Three more collection boxes were constructed upstream of the initial box in the early 1960's. From that point, the water is delivered to Thayne through a 10-inch transmission line. Excess spring water overflows into Flat Creek. The water level in the lower collection box is typically 2.5 feet higher than the water surface of Flat Creek pond. The bottom of the collection box is clearly below the pond surface. This box was originally built as a spring collection (vs. storage) facility and is open to infiltration. The box is subject to flooding and possible surface water contamination as presently constructed. This condition, in our opinion, represents a health and safety risk to the community. The overall spring collection area can be described as ''wet and marshy" during much of the year. The springs are, in our opinion, at risk from surface water influence. The health hazards are aggravated by the practice of grazing immediately upstream of the springs. Particulate (MPA) testing of the springs confirms that some surface water infiltration is occurring at the springs and/or in the transmission piping. The hydrogeology of the Flat Creek Springs was investigated by Tri-Hydro corporation. It was concluded by their study that the springs are "gravity springs of the fracture type" originating in the fractured conglomerate deposits of the Salt Lake Formation. The geology indicates that they are ''true'' groundwater sources. As presently developed, however, Flat Creek Springs could be classified as being "under the influence of surface water" thus requiring filtration treatment under EPA's Surface Water Treatment Rule (SWTR). 1-2

7 1.3.2 Spring Transmission Pipeline Spring water is delivered to Thayne through a 10-inch transmission pipeline approximately 6200 feet in length. It was constructed in Available record drawings indicate that the pipe is either concrete or asbestos cement. The line was not excavated as part of this study due to the reportedly fragile condition of the pipe and the high liability associated with water interruption to the town and the cheese factory. This line was placed further "at risk" when a localized mud slide occurred into the canal adjacent to the pipeline during the summer of Booster Pump Station The pump station is a packaged unit consisting of two 7.5 HP booster pumps operating at 3500 rpm. The original pumps installed in 1985 are still in use. They are each rated at 150 gpm with 100 foot TDH Disinfection System Thayne's water is continuously disinfected as it leaves the booster pump station. The disinfection system uses gas chlorine System Storage Thayne presently utilizes a single 300,000 gallon bolted steel tank. The tank was constructed in 1985 and appears to be in good condition. The tank elevation is considered "marginal" but acceptable based on DEQ chapter XII requirements for working pressures Distribution Piping The town's original distribution piping was constructed in the late 1940's. In 1985, PVC distribution piping was selectively constructed to replace older lines and to expand the system. There is concern about the condition and integrity of the older piping remaining in service. Overall, the Town of Thayne has been diligent in the maintenance of their distribution system. 1.4 WATER QUALITY HISTORY In general, the Town of Thayne has a history of full compliance with EPA water quality criteria. We are concerned, however, about the reported need for continuous disinfection to control bacteriological growth. MPA particulate testing was conducted as part of this study to ascertain if the towns supply was subject to surface water influence. Spring samples showed minor surface water influence. The influence was more pronounced in the samples taken from the transmission pipeline. 1-3

8 1.5 WATER SUPPLY NEEDS Thayne's water demand was measured on a relatively cool day in late June. It is fet, therefore, that the measured demands were probably reflective of usage between an "average day" and a "summer day" demand. An average summer day usage for Thayne can also be estimated from the measured pumping capacity and consistent reports that the Town's summer-time supply was marginally adequate with both pumps running. The measured pump capacity was 240 gpm indicating a per-capita summer day usage of about 1200 gallons per capita per day. This estimate appears to be realistic when compared with Bedford, Alpine, and other near by Star Valley communities. Based on that data, present and future water demands have been calculated. This information is presented in Table 1.1. Water needs are presented separately for the Town of Thayne (present and future), the Star Valley Cheese Factory, and outlying subdivisions. 1-4

9 TABLE 1.1 THAYNE AREA WATER SUPPLY NEEDS Riverv iew, (3) South brook and Town of Town of Town Of1) Star'2) Jeppersons Thayne Thayne Thayne Valley Subdivisions {prlllnl} {2g1g} {202 } Cheele {w/full buildoyt} No. Connections Est. Population N/A Served MOO MGD MGD MGD MGD Est. Average Day Demand (900 gpcpd) Est. Summer Day Demand (1200 gpcpd) Est. Peak Day Demand _(1500 gpcpd) Notes: (1) Future demands for the Town of Thayne are based on a 3% annual growth of the existing service area. (2) Star Valley Cheese demands are based on meter records provided by the plant. Future demands are assumed to remain constant. (3) Subdivision demands assume full build-out based on discussions with Lincoln County planning office. Population estimates are based on 2.3 persons per household. Jepperson Subdivision: 6-18 lots Southbrook Subdivision: 39 lots Riverview Subdivision: lots (4) Peak day demand based on current peak system pumping capacity of approximately 300gpm±. 1-5

10 1.6 WATER RIGHTS (FLAT CREEK) On July 29, 1947, shortly after the Town of Thayne was incorporated, the town and the Star Valley Cheese factory successfully filed for proportionate water rights to the Flat Creek Springs. Thayne was granted rights to cfs (300 gpm) and the cheese factory was granted rights to cfs (500 gpm). Subsequent water rights to the Alpha and Beta springs in the same drainage were granted equally to the town and the cheese factory. It appears that the Alpha and Beta springs were never developed. These water rights are summarized in Table 1.2 below. TABLE 1.2 TOWN OF THAYNE/STAR VALLEY CHEESE WATER RIGHTS TOWN OF STAR VALLEY EBMII tl. E!RIORITY SOURCE TI::IAYE CHEESE EAIORY July 29, 1947 Flat Creek CFS CFS Springs Jan. 8, 1949 Beta Spring (Flat Creek) Jan. 8, 1949 Alpha Spring MQ MQ (Flat Creek) CFS CFS (690 gpm) (890 gpm) 1.7 RECOMMENDED IMPROVEMENIS Thayne is presently facing EPA compliance and water supply problems primarily due to increasingly rigid regulatory requirements and increased demands on the system. Recommendations for addressing these long-term concerns are shown schematically in Figure 1.2 and discussed below: Redevelop Flat Creek Springs and Reconstruct Transmission Pioeline It is recommended that the Flat Creek Springs be fully redeveloped as required to minimize the potential for surface water influence. This is felt to be necessary to avoid the need for filtration under EPA's Surface Water Treatment Rule. It is also recommended that the transmission line from the springs to town be replaced due to it's age, fragile condition, and localized soil failure(s). 1-6

11 ,- ' ---- "--.. / ' -"- -- LEGEND J ' rv - --I (" ',.J : 14 1 \ " -- '- "7L ' - t I () \ ROADS ELEVATION CONTOURS RIVER/CREEK WATER TANK SPRING EXISTING PIPELINE CORPORATE LIMITS PROPOSED PIPELINE!.{l : _!J I-- - i (: ROBERTS ST.! ") 6" \ L ll / / r t,.. ', I r':--=-} \\ \-=>:!'.\ ' 10" 0 : \ '" : I CORPORATE LIMITS 1 : PROSED j {]d' 1.-iI[.r r -" l=i TRAN=S=M=ISS;'ONiLliNEAI S", \!,\il '1-0::':"!-l :' 4"«o '1'- f (. I \ \-- \li '\ : " 1'L PROPOSED THA NE 1 NO. MUNICIPAL WELL, "\t-.;;--\ " f --,\, '"'\'0 I \ \ \ I " '\ EESE AR VALLEY PLANT TOWN OF THAYNE. ROVEMENTS PROPOSEEDWR SYSTEM THAYN ) /1 ::::::c::c===-::;.:. R S GR E N "'OCIATES F A / INC, FIGURE:

12 1.7.2 Construct Supplemental Groundwater Well and Transmission Line A supplemental groundwater well is recommended to meet Thayne's longterm water supply needs. This well will also provide important system redundancy to better protect the public health and safety during emergencies. A successful test well was drilled, tested and developed as part of this Level II Study Well Head Protection Presently there are no detailed regulatory requirements in place for well head protection. There are many preventive "common sense" things the Town and County can do to protect Thayne's groundwater supply. Perhaps the most important among these is the proper control of the potentially detrimental aspects of development (such as septic systems) in the vicinity of the well. For that reason, it is recommended that the town extend their present sewer collection system east to the center of Section 24 near the well as part of this project. This represents a relatively inexpensive and proactive approach for better protecting Thayne's valuable groundwater resource Install Meters Master meter(s) are recommended to allow the town to better track actual water consumption in the future. This can be a valuable management tool for system planning and operation. It should also be noted that individual meters are a requirement for RUS funding. 1.8 ECONOMIC DATA Star Valley Cheese Factory The Town of Thayne and the Star Valley Cheese factory have been friends and economic partners in the community for many years. The town and the cheese factory are each viewed as independent drinking water systems by the EPA even though they share the Flat Creek Springs and transmission line. This project may provide the town and the cheese factory with an excellent opportunity to negotiate a water service agreement in which the town would accept responsibility for operation and maintenance of the springs and the cheese factory would receive water from the town at an agreed user rate. This approach would eliminate redundant water quality testing and simplify water rights issues Thayne project Budget The budget for the 'NWDC eligible project is $945,200 as summarized in Table 1.3. It should be noted that this budget includes $85,000 for the cost of the well drilling as part of this Level II study. Non-eligible costs are summarized in Table

13 1.8.3 project Financing It is present practice for WNDC to fund this type of eligible project with a 60%. grant and a 40% loan at 7%% annual interest over a period of 20 to 30 years. Items considered ineligible for W'NDC financing are proposed to be funded through the Wyoming Farm Loan Board program with 50% grant and 50% loan (7%% interest, years). The Town of Thayne is classified as a "Iow-to-moderate" income community and qualifies for federal funding through the USDA Rural Utility Service, (RUS, formerly FmHA) program for this type of project. The town can reduce user rate impacts by requesting RUS loan money in lieu of \N\NDC loan money at a lower interest rate. (Estimated to be 5.0% vs. 7.25%). It should be noted that the RUS program requires the installation and use of individual water meters as condition of funding. Funding scenarios with and without RUS funding participation are summarized in Tables 1.5 and

14 TABLE 1.3 TOWN OF THAYNE PRELIMINARY PROJECT BUDGET SUPPLY, TRANSMISSION, AND STORAGE NEEDS WWDC ELIGIBLE COSTS Item No. Description Est. Cost 1 Flat Creek Springs Rehabilitation $235,000 2 Spring Transmission Line $135,900 *3 Groundwater Well $189,400 4 Well Transmission Line $ 83,400 5 Misc. $ 30,400 Subtotal $674,100 Preparation of Plans and Specs Permitting & Mitigation Legal Fees R.O.W. Acquisition $ 64,800 $ 7,000 $ 6,000 $15,000 Construction Cost (from above) $674,100 Construction Engineering (10%)-( exclusive of well drilling) $ 58,900 Subtotal $733,000 Contingency (15%) $110,000 Construction Total $843,000 $843,000 PROJECT TOTAL $935,800 *Note: Includes cost of well completed as part of Level II study. Well to be purchased by the Town of Thayne from WWDC. 1-9

15 TABLE 1.4 TOWN OF THAYNE PRELIMINARY PROJECT BUDGET METERING, DISTRIBUTION, MISCELLANEOUS NON-WWDC ELIGIBLE COSTS (including meters) Item No. Description Est. Cost 1 Service Meters $109,700 2 Highway 89 & Wright St. $ 4,500 3 Sewerline Extension (well head projection) $ 27,600 Subtotal $141,800 Preparation of Plans and Specs Permitting & Mitigation Legal Fees R.O.W. Acquisition $14,200 $ 0 $ 0 $ 0 Construction Cost (from above) $141,800 Construction Engineering (10%)-( exclusive of well drilling) $ 14,200 Subtotal $156,000 Contingency (15%) $ 15,600 Construction Total $171,600 $171,600 PROJECT TOTAL $185,

16 TABLE 1.5 TOWN OF THAYNE TYPICAL PROJECT FUNDING *(WITHOUT RUS LOAN PARTICIPATION) - NO METERS *\NWOC Grant (60%) \NWOC Loan (40%) WFLB Grant (50%) WFLB Loan (50%) Annual Loan Payment (7%% - 30 year) Monthly rate impact (181 equivalent connections) $ 510,500 $ 374,300 $ 21,000 $ $ 926,800 $32,660/year $15.Q4/conn.lmo. *Note: WWDC Grant amount reduced by $51,000 to reflect 60% of the cost of well drilling already completed and paid as part of Level II Study. TABLE 1.6 TOWN OF THAYNE PROJECT FUNDING (WITH RUS LOAN PARTICIPATION) -INCLUDING METERS WNDC Grant (60%) WFLB Grant RUS Loan Annual Loan Payment (5% - 30 year) Monthly rate impact (181 equivalent connections) $ 510,500 $ 92,900 $ $1,075,500 $30,710/year $14. 14/conn.lmo. Notes: 1. Thayne's median per household income ($17,969.00) is per connection. Assumed RUS interest rate = 5%. 2. Project loan costs reflect $5,000 for bonding. 3. WWDC Grant amount reduced by $51,000 to reflect 60% of the cost of well drilling already completed and paid as part of Level II Study. 1-11

17 1.8.4 User Rate Impacts Average "immediate" user rate impacts are estimated to be between $14.14/conn/month and $15.04/conn/month depending on RUS funding participation. 1.9 WHAT NEXT It is recommended that the Thayne Water Project be advanced to a Level III status for WWDC funding of design and construction. 1-12