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West Point Treatment Plant
Find information and facts about West Point Treatment Plant located next to Discovery Park in Seattle, including the treatment process, capital and improvement projects, and ongoing public engagement.
Updates
December 1, 2025
Temporary traffic change on Discovery Park Boulevard begins as early as January 5, 2026
King County Wastewater Treatment Division (WTD) will close one lane of traffic to repair a portion of Discovery Park Boulevard for three weeks. The work will take place on weekdays from Monday, January 5, through Friday, January 23, 2026. One travel lane will be closed, but vehicle through-traffic will be maintained. Learn more about travel impacts.
Part of the work will include removing two small trees and trimming back some foliage along the roadway. WTD will follow local requirements for replacing plants that were removed during construction. Construction schedules are approximate and subject to change. Check back here for updates to the schedule.
Necessary repairs
A section of Discovery Park Boulevard has developed a noticeable dip due to a failing stormwater pipe beneath the roadway. This pipe damage has caused the ground beneath the road to sink. WTD will repair the road to maintain access to our essential wastewater treatment facility and the scenic South Beach area of Discovery Park.
Looking ahead
This is a short-term, temporary solution to fix the dip in the roadway. In the future, there will be a long-term fix to better stabilize the roadway and ensure continued access to West Point Treatment Plant and the South Beach parking area. WTD is working closely with the City of Seattle to determine the plan for a long-term repair. .
Located next to Discovery Park in Seattle, West Point Treatment Plant (West Point) began operating in 1966. West Point cleans more wastewater each day than any other plant in Washington. Approximately 90 million gallons of wastewater per day are treated at the facility during the dry months. Seattle’s combined stormwater/wastewater sewer system also flows into West Point. West Point serves homes and businesses in Seattle, Shoreline, north Lake Washington, north King County, and parts of south Snohomish County.
Learn more
- Learn how West Point's treatment process works.
- Get the facts on the West Point's operations.
- Discover how West Point contributes to a sustainable future for the surrounding community and environment.