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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

Brightwater Treatment Plant

The Brightwater Treatment Plant is located along State Route 9, north of Woodinville, in unincorporated Snohomish County. The plant is part of King County's regional wastewater treatment system. Every day Brightwater treats wastewater from homes, offices, schools, agencies, businesses and industries in north King County and south Snohomish County.

Brightwater has the capacity to treat an average of 36 million gallons of wastewater per day (mgd). By 2040, treatment capacity may be expanded to 54 mgd. These capacities are for average wet-weather flows.

The plant design integrates landscape, architecture, wildlife habitat, engineering, art, and education.

Brightwater Center | NPDES permit

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Contact us

24 hour emergency and odor reporting: 206-263-9500
Administration: 206-263-9465

22505 State Route 9 S.E.
Woodinville, WA 98072-6010;
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