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1. Whitefish Stage Sewer Interceptor UpdateC,ity of Kalispell Public Works Department Past Office Box 1997, Kalispell, Montana 9903-1997 - Telephone (406)758-7 t20, Fax 6`g75 - 7 31 REPORT TO: Mayor and City Council FROM: James C. Hansz, P.E., Director of Public W SUBJECT: Whitefish Stage Road Sewer Extension Eng°�e g Report MEETING DATE: Work Session 22 February 2005 BACKGROUND: At the meeting of 20 December 2004 City Council approved Resolution 4965 directing staff to conduct preliminary engineering for extension of sewer north along Whitefish Stage Road to Rose Crossing. The intent of the extension is to serve development in the area of the proposed Two Rivers Master Plan Amendment currently under review by Flathead County. Using the current task order contract for the City's wastewater treatment plant expansion project, Task Order #2 was issued for the work which included analysis of the new development area to identify potential population to be served, flow impacts on the system, and facilities required to meet demand. Several alternatives were developed and a preferred alternate was identified. In addition, in response to direction taken during the initial work session on this issue, the task order was amended to include these work items for water. All this work was performed within the cost ceiling established by City Council in Resolution 4965. Work was completed within 20 working days of execution of the task order. A copy of the final draft report is attached for your review. SEWER: The report identifies three options for extending a 15-inch diameter sewer from the vicinity of West Evergreen Drive and Whitefish Stage Road north to Rose Crossing. Due to severe conflicts with underground utilities not known to exist at the time of the first work session, the recommended alternative is to extend sewer north along the easterly edge of the north -bound travel lane of Whitefish Stage Road to Rose Crossing. This will avoid costly relocations of other utilities and possible damage to the main AT&T fiber optic cable linking Spokane with Calgary. It will require significant pavement rehabilitation, but we believe this cost can be managed. The estimated construction cost of this alternative is $1,841,000.00. This cost includes a 20% contingency. Engineering is anticipated to be completed in- house. Staff currently is working on this in anticipation that Council will give direction for a spring contract let date. This target date was indicated during the initial work session discussion. This extension will serve approximately 2,000 acres and a service population which could reach 8,000 at build -out. WATER: The report also examined the feasibility of providing water service for the area. This is somewhat more difficult because there are no City facilities east of the river which may be conveniently February 22, 2005 Whitefish Stage Server Extension.doe extended. Service would require extension of facilities from the vicinity of Home Depot. Nonetheless, four alternatives were identified, two involving extensions of main line only and two involving main line and a production well to enhance capacity within the installed main. The recommended alternative would install a 12-inch diameter main with a 500 gpm production well in the service area. The estimated construction cost of this alternative is $1,791,000.00. This cost includes a 20% contingency. Engineering is anticipated to be completed in -Douse. The recommendation to install a 500 gpm well is intended to allow for greater flexibility of design, reduced construction costs, and an increased probability of achieving the desired flow rate. This configuration would allow for service to be provided to a population of approximately of 4,600 with additional capability to serve more than 6,000 by adding an additional well. As the served population continues to rise additional facilities for storage and/or production may become necessary. A fifth alternative, a potential stand-alone satellite extension that would not be directly connected to the existing City water system was briefly examined. This alternative was not developed in detail for reasons stated in the report. The report will be reviewed with City Council at the work session of 22 February, and staff and the consultant will be available to answer questions and receive direction from City Council regarding further development of this project. February 22, 2005 whitefish stage server Eixtension.doc