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Wastewater Treatment

King County, Washington

For questions about the Wastewater Treatment Division website, please send an e-mail message or contact us at:

King Street Center
201 S. Jackson St., Suite 500
Seattle, WA 98104-3855
Phone: 206-477-5371
Fax: 206-684-1741
Telecommunication device for the deaf (TTY): 711

Get Directions to our office location in Seattle, Washington.

Staff Contacts

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.

Newsletters | NPDES permit  

West Point
View more photos (external link, Flickr).


West Point Treatment Plant Sewer News
  • Fall 2015 (PDF, 2MB)
    • West Point Treatment Plant turns 50!
    • Save yourself the aggravation, don't park in the West Point's emergency turnaround areas
    • King County has asked the City of Seattle to expand the allowable access hours for biosolids trucks
    • Upgrade to water reservoirs near Loop Trail in Discovery Park
    • West Point Treatment Plant has earned another Platinum Peak Performance Award 
  • Spring 2014(PDF, 1MB)
  • Summer 2013 (PDF, 800KB)
  • Summer 2012 (PDF, 2MB)
  • Spring 2011 (PDF, 735KB)

New hours for Loop biosolids trucks entering and leaving King County West Point Treatment Plant have been approved by the City of Seattle. Learn more.

Contact us

24-hour emergency and odor reporting: 206-263-3801
Administration: 206-477-9800

1400 Discovery Park Blvd Seattle WA 98199
View directions and map.

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