Vashon Treatment Plant
The Vashon Treatment Plant, located on Vashon Island, is part of King County's regional wastewater treatment system.
It treats wastewater from homes and businesses within the Vashon Sewer District. Approximately 180,000 gallons a day of wastewater is treated at this facility. A maximum of 1.4 million gallons per day can be treated during the rain/storm season.
View the Vashon Treatment Plant Spring 2022 newsletter .
View more photos on our Flickr site .
Contact us
24 hour emergency and odor reporting: 206-263-1760
Administration: 206-463-7318
Address
9615 S.W. 171st St.
Vashon, WA 98070
Related content
Public treatment plant tours (available but limited)
Education resources for schools and community groups
View NPDES permit