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09/26/94 Fraser/Kalispell North Water Well-THC)MAS, DEAF- ": HOSKfNS 1 ENGINEERING CONSULTANTS No. 6 Sunset Plaza • Kalispell. Montana 59901 • 406) 752-5246 • FAX (406) 752.5230 September 26, 1994 John Wilson, City Engineer City of Kalispell P.O. Box 1997 Kalispell, MT 59903-1997 RE: Kalispell North Water l eo,- Dear John: e1)605 Please find enclosed the Supplemental Design Report for the Kalispell North Water prepared as a comparison of the DSL well and college site. If you have any questions, please feel free to contact us. MWF:mj K94-28-9 Encl: a:jw.ltr Very truly yours, THOMAS, DE �;712� &C. Vh4 W. Fraser OFFICES IN GREAT FALLS, BOZEMAN, KALISPELL AND SPOKANE A comparison of Department of State Lands Well and New Wells Introduction The City of Kalispell has developed the hydrological analysis and recommendations for construction of two 12" diameter wells on the college property with the potential for supplying 2,000 gpm to the upper zone. An evaluation has also been completed on the potential of utilizing a large diameter irrigation well located on the Department of State Lands (DSL) property as a supplemental source for the upper pressure district in lieu of the two 121, diameter wells. A joint comparison of the alternative wells with an evaluation of the benefits and drawbacks as well as costs must be completed to provide the City adequate information for determining the best source for meeting the needs of the upper pressure district. Basic groundwater criteria will be used as a comparison of the two alternatives to provide the basis for recommendation. The evaluation will generally follow the criteria established by the Water Quality Bureau in Circular One for Ground Water Development. Quality Both wells hydrologically would withdraw water from the same aquifer. This aquifer is apparently the aquifer currently being tapped by the Buffalo Hill well. All chemical criteria are in compliance with State and EPA rules. The City has every reason to believe either alternative source would have the same quality and meet the rules. Well head protection is also an issue which must be addressed. Well head protection will become a more stringent requirement over time. The college site is sewered by the City and has historically had agricultural uses limited to farming. The nearest industrial use is NUPAC, approximately one mile north. Groundwater flow is from the north to south. Industrial uses on the NUPAC site are limited and would probably not pose a risk to wells on the college property. The Department of State Lands well (DSL) is immediately north of an agricultural feed operation and is surrounded by agricultural properties similar to those north of the college property. There are no known chemical spills or contamination sites near or adjoining this site. The City have every reason to believe there are no potentials for contamination. The aquifer is very similar throughout these sections of the Flathead Valley. The data available on the DSL well indicates a 3,000 gpm test pump but over a very limited time period. The quality of the aquifer would indicate 2,000 gpm is available at the site. The hydrological evaluation of the college property indicates the available water, 2,000 gpm, is expected to be produced at the college site with minimal impact on the aquifer. Well production is limited by two factors other than the aquifer capability, inlet velocities and test pumping. The DSL well is perforated and based upon the well log and calculations the inlet velocity is 7.6 times the velocity allowed by the standards. A deviation from the standards would be required to allow this well's use as a public water supply. There is also a concern over long term production from the well at excessive velocities which could cause crustations in the openings and over time reduce the efficiency and yield of the well. The excessive inlet velocity also creates greater drawdown to produce the same quantities of water and therefore decreases the efficiency of the well which results in an increase in pump horsepower and long term energy costs. Construction of two new wells on the college property meeting the requirements of the standards would result in efficient wells with adequate area so the inlet velocities are less than the standards. Additional perforations may be added to the DSL well for a cost. It is doubtful enough perforations could be added to provide inlet area to meet the standards. Adding additional perforations to the well would also result in the need to further develop the well at a cost. Construction The DSL well is constructed with 20" and 161, casing. Casing thickness meets the standards. Well logs do not indicate a surface seal is present. One would have to be added or a deviation obtained to meet the standards. The log does not indicate a seal is present between the 161, and 201, casing. One would have to be added or a deviation obtained from the standards. The test pumping does not meet the standards. An additional test pumping would have to be completed to meet the standards and to determine the actual yield of the well. Construction of wells on the college property would be according to the standards. At the completion of the construction the wells would be useable for the City with no additional work, with the assurance that all the features meet the requirements of the standards. Well head development is the pumping and transmission improvements necessary to bring the water to the City to be utilized in the system. The college property adjoins a 12" line and a very short length of main would be necessary. One pump house would be built which would provide the metering and future chlorination facilities for the wells at the college. The DSL well is well over a mile from the City. Because of this distance a 16" main is recommended to reduce the friction and head losses and improve the efficiency of transmission. The cost of this main is considerably greater than the cost of the connection improvements for the college property. Costs Two separate cost estimates have been prepared for the alternatives and are enclosed as an attachment to this report. Development of the wells on the college property provide the greatest economy both in construction and efficiency for the City. Recommendations Over all the DSL wells suitability and immediate availability is unknown, since it is currently committed as part of the lease hold improvements to agricultural user. It could be utilized as part of an expansion of the Cities system at the time the property is acquired, which may be several years away. The need for additional supply is eminent within the north upper pressure zone. Delaying the supply for several years could result in loss of essential service during critical time periods as well as place a undue strain on the Buffalo Hill Well. When all factors are considered, the continued development of the wells on the college property appears to be in the best interest of the City. The utilization of the DSL well should also be held as a benefit to the property as a fair grounds site. This benefit may either be as irrigation water or as additional supply to an ever expanding City system. Prepared By: THOMAS, DEAN & HOSKINS, INC. Utv� Michael W. Fraser K94-28-9 A:SUPPLEME.DSG UXT '- Test Well Production Wells Construction $ 66,500.00 Contingency 6,650.00 Engineering etal 10,400.00 Subtotal $ 83,550.00 ;;0 Contingency0000 LegalAdmin. 26,200.00 Subtotal $ 229,675.00 Piping, Pumphouse & Telemetry $ 180,580.00 Contingency 18,100.00 Engineering, Legal Admin. 36,200.00 Subtotal $ 234,880.00 TOTAL PROJECT $ 548,105.00 May 12, 1994 DEPARTMENT OF STATE LANDS PROJECT COST ESTIMATE Phase I - Well Evaluation Estimated Unit Item Description Quan/Unit Price Amount 1. Install Meter for Test Pumping Lump Sum $ 2,000-00 2. Test Pumping & Monitoring (Labor Only) 48 Hrs. $ 90.00 4,320-00 3. Remove and Replace Pump 24 Hrs. 125.00 3,000.00 4. Television Inspection 400 L.F. 15.00 6,000.00 Subtotal $ 15,320.00 Contingency 6,000.00 Engineering, Legal, Administration and Construction 4,800.00 TOTAL $ 26,120.00 Phase II - Well Improvement Estimated Unit Item Description Quan/Unit Price Amount 1. Perforations 100 L.F. 200.00 $ 20,000.00 2. Surface Seal/ Grout 50 L.F. Lump sum 10,000.00 3. Casing Seal 1 EA Lump Sum 6,000.00 Subtotal $ 36,000.00 Contingency 7,200.00 Engineer, Legal and Administration 4,400.00 TOTAL $ 47,600.00 September 22, 1994 1. Piping, Pumphouse Telemetry I EA Lump Sum $180,580.00 2. Transmission Main 16" PVC 7600 L.F. 40.00 304,000.00 3. Connection at Grandview including Bore 1 EA Lump Sum .21,500.00 Subtotal $512,080.00 Contingency 51,208.00 Engineering, Legal, Administration, and Construction 85,000.00 TOTAL $648,288.00 TOTAL PROJECT $722,008.00