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The Vashon Sewer District contracted with King County in 1999 to take over operation of the Vashon Treatment Plant.

King County constructed a new treatment plant (completed in 2006) next to the existing treatment plant.

The plant was dedicated at a community open house in May 2007  .

Regional system history

In 1958 voters approved the creation of a regional wastewater treatment system to clean the wastewater being generated from the developing cities. Metro was formed as the organization to build and manage this system and was later merged with King County. More regional wastewater system history.

rsz_15099156863_fb1303681a_zVashon Treatment Plant ribbon cutting event 2007

View more photos on our Flickr site  .

Contact us

24 hour emergency and odor reporting:   206-263-1760
Administration:  206-463-7318

9615 S.W. 171st St.
Vashon, WA 98070

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