Reserve Street Lift Station

The City of Missoula’s new Reserve Street lift station increased capacity and saved money and energy at the same time.

In 2008, the City of Missoula planned to upgrade the failing Reserve Street Lift Station but had to stop due to the recession. Years later, when the city started again on the project, Morrison-Maierle bid on the project and completed construction administration services. After reviewing the original plans and current conditions, Morrison-Maierle determined it would be best to use a new approach.

The 2008 plans called for a two-pump system (a lead pump plus a standby).
Morrison-Maierle determined that the pumps would be very large and difficult to service due to the depth of the wet-well (over 35 feet deep). This setup also meant that the pumps were switching on and off several times an hour—increasing wear and tear, electrical usage, and maintenance needs.

Morrison-Maierle proposed moving away from the traditional two-pump approach to a four-pump system. This configuration results in smaller pumps with less horsepower, but greater responsiveness to changing flows throughout the day (peak flow mid-day, low flow during nights).
The pumps also used Variable Frequency Drives (VFD), which allow the lift station to respond to changing flow conditions and come on, and stay on, rather than shutting on and off multiple times an hour. VFDs also offer greater flexibility in operating speeds and flow ranges than traditional
pumps which also saves energy.

Morrison-Maierle also developed a strategy to construct the project outside
the footprint of the existing wet-well so the project could be built during the
winter. This choice addresses potential groundwater problems and reduces the amount of bypass pumping. The project was completed in April 2020, just four months after construction start.

The City of Missoula now has ample levels of service for existing and anticipated use, and they are saving $500 a month in energy use. Because of these savings, the city will pay the pumps off in 20 years simply due to lower electrical bills from this project.