Seattle Public Utilities Mami Hara, General Manager/CEO

Fremont Ship Canal Water Quality


The Fremont site for the Ship Canal Water Quality Project.

What & Why

Seattle Public Utilities (SPU) and King County’s Ship Canal Water Quality Project is a 2.7-mile, approximately 14-18-foot diameter tunnel that will capture and temporarily hold more than 15 million gallons of stormwater mixed with some sewage during heavy rains. When the storm passes, flows will be sent to King County’s West Point Wastewater Treatment Plant in Magnolia.

The Ship Canal Water Quality Project includes the following activities in Fremont:

  • Building the new storage tunnel
  • Installing new pipes to convey polluted stormwater and sewage to the tunnel
  • Building a drop shaft to collect flows entering the tunnel near the intersection of 3rd Avenue NW, Leary Way NW and NW 36th Street
  • Building a new microtunnel under the Ship Canal to convey polluted stormwater and sewage from Queen Anne to the new storage tunnel
  • Providing odor control to minimize odor

What’s happening now?

Elements of the Ship Canal Water Quality Project in Fremont are currently in the design phase. Construction is expected in 2019.

Project goals and benefits

Once complete, the Ship Canal Water Quality project will prevent 60 million gallons of raw sewage and polluted stormwater from flowing into Lake Union, the Ship Canal, and Salmon Bay each year.

Meetings and Events

Attend a community event to learn more about upcoming work in Fremont and Wallingford:

Fremont Sunday Market
Sunday, November 5, 10 a.m. – 4 p.m.
3410 Evanston Ave North, Seattle, WA 98103

Fremont PCC Market
Thursday, November 9, 4 – 6 p.m.
600 N 34th St, Seattle, WA 98103


Richard Fernandez
(206) 684-0285

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