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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

Wastewater Treatment Division

King County, Washington, protects water quality and prevents water pollution by providing wastewater treatment to 17 cities and 17 local sewer utilities. The county's Wastewater Treatment Division serves about 1.5 million people, including most urban areas of King County and parts of south Snohomish County and northeast Pierce County. More about our system and facilities.


Start you RainWise project today! Get ready for spring! Learn more.
The RainWise program provides rebates that cover most or all of the cost of installing cisterns and rain gardens on your property. To receive a rebate, you must live in an eligible combined sewer overflow basin. Learn more.

Community Voices videos
Our Duwamish: In this series of Community Voices videos, residents talk about why they live here and share their vision for the neighborhood’s future.

West Point Treatment Plant tour
View a tour of the West Point Treatment Plant.

Loop -- turn your dirt around
Turn your dirt around. Learn more about Loop.

Reporting and viewing problems

Doing business with WTD

Learning about projects (under construction or in planning)

Getting involved in protecting the environment--citizen action

Related agencies

Regional wastewater treatment plants



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