Kalispell readies for massive sewer project

As Kalispell continues to grow, the strain on infrastructure is exacerbated. New developments are constructed and expanded underground pipes are required to service new homes and businesses.

Last week, Kalispell opened up a request for bids from contractors for the massive Westside Interceptor Project, which will allow for continued development to the west and north of the city.

More than 40,000 feet of sewage line between 21-inch and 30-inch diameter will be constructed to carry sewage to the wastewater treatment plant on the south end of town. The $10 million project is targeted to begin in June and wrap up by December.

The work has been broken up into five phases. Most of the pipes will use gravity to transport waste, but because of topographic constraints seven pump stations are planned.

Once complete, the sewer lines will expand capacity by 4,936 developable acres, or give the city the capacity to accommodate nearly 45,000 additional people, said Public Works Director Susie Turner.

The project will be financed by a loan from the state revolving loan fund for the full cost of the project. The 30-year loan is fixed at 2.5 percent interest, and will be repaid from funds taken from the municipal sewer impact fee, Turner said.

She said that while the county has been involved, the project is completely driven by city resources.

The city is doing our own facility planning and putting in projects to meet growth and to alleviate some of our current capacity issues in the downtown area,” Turner said.

The new line begins near Flathead High School and runs the length of the U.S. 93 bypass to Reserve Drive on the north end of town.

The first section will hook into a 30-inch section of pipe about two blocks south of Flathead High School and meander northwest until it crosses the U.S. 93 bypass. A section of piping was installed beneath the bypass when it was built in anticipation of the project.

From there, the second section runs from the west side of the bypass just beyond the point where it crosses under and up to the vicinity of Two Mile Drive.

A section of the piping will be installed along a stretch of Two Mile Drive between Big Sky Boulevard and Skyline Drive. The contractor that does that section will be required to stagger road closures to minimize the impact on area residents. The second section extends north after passing Skyline Drive for a short distance.

The third phase is shorter but also requires the construction of several pump stations. The third and fourth sections traverse north past Three Mile Drive and Four Mile Drive and ends near Glacier High School.

The fifth and final section spans Old Reserve Drive between Stillwater Road on the west and U.S. 93.

Last week Flathead County Commissioners heard from Ryan Mitchell of Robert Peccia & Associates about the project. The firm analyzed zoning requirements and future density projections using Geographic Information System technology to determine how the new piping should be constructed to best serve the city.

Commissioners asked some questions about the technical details of the project, including how long different sections would be and clarifying that not all of the roads would be shut at the same time during the work.

Commissioners also made sure that the manhole covers used to access the lines from the street would placed in the middle of one of the lanes.

“Wow this is a big project — holy smokes,” commissioner Phil Mitchell commented.

A complete schedule and more information about each section can be found on the city website, at http://www.kalispell.com/bids.aspx?bidid=7.

Reporter Peregrine Frissell can be reached at (406) 758-4438 or pfrissell@dailyinterlake.com.