West Point Treatment Plant
West Point, located next to Discovery Park in Seattle, is part of King County’s regional wastewater treatment system.
West Point treats wastewater from homes and businesses in Seattle, Shoreline, north Lake Washington, north King County and parts of south Snohomish County. Seattle’s combined stormwater/wastewater sewer system also flows into West Point.
Approximately 90 million gallons a day of wastewater is treated at this facility during the dry months. During the rain/storm season, West Point provides secondary treatment for flows up to 300 million gallons a day (mgd) and provides primary treatment and disinfection for flows exceeding 300 mgd and up to 440 mgd.