Pump Station 22

Project Description

The Magnolia Basin 60 is a combined sewer basin located south of the Ship Canal and directly to the east of Discovery Park. In this area, stormwater and sewage in the basin is collected and flows to Pump Station 22.
During heavy rain events, high volumes of stormwater can overwhelm the pump station causing an overflow into Salmon Bay. The combined mixture of stormwater and sewage can be harmful to humans, aquatic life, and other wildlife.
For the Pump Station 22 Retrofit and Force Main Replacement project, Seattle Public Utilities (SPU) will upgrade the pumping capacity of the pump station and the sewer pipeline in the Magnolia neighborhood.
This project will help reduce the number of overflows and improve water quality offshore. In addition, SPU will perform safety improvements to the pump station as part of the project.


Construction will occur along W Cramer St, 40th Ave W, and Commodore Way with most of the work occurring at the street end of W Cramer St.

What's Happening Now?

A contractor has been selected for this project and construction is expected to begin in mid-September. We expect construction to wrap up in Fall/Winter 2020. Work started on W Cramer St, where crews are installing a new force main under the street. Crews plan to work their way south on the west side of 40th Ave W to the intersection with W Commodore Way. Later this year, crews will begin work at the pump station. Residents will be notified prior to starting this phase of the work. Project work will be broken into smaller work areas to minimize impacts on residents and commuters.

Community Benefits

  1. New pavement and ADA ramps along the alignment of the new force main.
  2. Replacement of pump station infrastructure that is near the design life cycle.
  3. Better water quality by reducing combined sewer overflows.
  4. Improved safety conditions for SPU pump station maintenance crews.
  5. The creation of a shoreline viewpoint and public access at the street end of W. Cramer Street in accordance with Seattle Municipal Code 23.60A.578.

Anticipated Impacts

What you can expect during construction

  • Typical work hours are Monday through Friday, 7 a.m to 5:30 p.m.
  • Increased construction traffic, noise, dirt, and vibrations
  • Pavement excavation and restoration
  • Parking restrictions in areas adjacent to work zone
  • ocal access to homes will be maintained to the extent possible
  • Lane reductions on 40th Ave W and W Commodore Way during force main replacement
    • During lane restrictions, flaggers will be onsite to maintain two-way traffic via the open lane.
    • When possible, the contractor will re-open travel lanes in both directions during nights and weekends
    • Access to driveways will generally be maintained through most of construction. The contractor will coordinate with impacted residents, as needed.
    • Later in construction, W Commodore Way will be closed 24/7 while crews connect the new force main to King County's pipe. Local access and pedestrian access will be maintained. Through traffic will be detoured around the site.
  • Regular solid waste pickup will be maintained
  • Emergency vehicles will continue to have access throughout construction

The contractor plans to stage equipment at Fort Lawton to mitigate construction equipment in the roadway. To access the potential staging area, the contractor will primarily use Texas Way and 40th Ave W.
SPU will provide updates to the community during construction. To receive updates about the project, please subscribe for updates by submitting your email on the right-hand side of this page.
SPU has performed work on an emergency force main replacement project in the area in 2019. That was a separate project to replace a damaged sewer force main that runs underneath the Shilshole Bay Waterway west of Commodore Park.

Community Engagement

SPU will provide updates to the community during construction. To receive updates about the project, please subscribe to the project email list.


Early 2018

  • Designed phase neighborhood outreach
  • Held community drop-in session
  • Project design continued

Mid 2018

  • Project design continued
  • Permitting and environmental review process

Late 2018

  • Conducted final design phase neighborhood outreach
  • Held community open house

Early 2019

  • Finalize design and award construction contract
  • Pre-construction community notification

Late 2019

  • Construction tentatively scheduled to begin in fall 2019 and take about 12 to 14 months*
  • Construction updates, as needed, via website and listserv

Mid- to Late 2020

  • Complete construction

*Schedule is dependent on weather and other factors.