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