Lift Station Design

Challenge

The City of Plymouth, Wisconsin, planned to improve two lift stations and add a third to resolve issues with high flows within their sanitary sewer system. Cleaning and maintaining the existing lift stations were problematic due to continuous high flows that prevented complete shutdown or the ability to isolate portions of the lift station.

The steel can style lift stations required confined space entry during routine maintenance tasks. The city requested eliminating this requirement in the design of the new lift station.

The city wanted to replace the steel can type municipal lift station on CTH PP, rehabilitate the steel can style municipal lift station at the Sunset location, and add a new lift station at Willow Road.

Solution

Kapur prepared the design and provided construction management for the three lift station projects. Site grading and associated landscaping were included. The site access road and parking areas at the lift stations were designed to accommodate heavy-duty maintenance truck traffic.

• Willow Road Lift Station – The new 30-foot-deep wet well was designed with a dry cell for future flows. Initially, two submersible pumps were installed on the active side and a third pump will be installed as flows increase over time, thus doubling the capacity of the lift station with no extended detention times.
• CTH PP Lift Station – The upgraded 34-foot-deep wet well was designed with a splitter box on the headworks that separates the flow coming into the wet well into two chambers, each containing two new submersible pumps. This design feature allows the owner to isolate half the wet well for cleaning without shutting the station down.
• Sunset Lift Station – The 21-foot-deep wet well was designed with an above-ground pump station, which allows the owner to maintain the system without entering underground structures.

Results

The designs of all three lift stations eliminated the need for confined space entry during routine maintenance. The ability to isolate flows makes cleaning the lift stations much easier.