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Brightwater Treatment Plant

Find information and facts about Brightwater Treatment Plant located near Woodinville, including the treatment process, capital and improvement projects, and visiting the facility and grounds.

October 2025

Brightwater is part of King County’s regional wastewater system and serves parts of north King County and south Snohomish County.

Brightwater was recognized for outstanding performance by the Department of Ecology! We appreciate our skilled operators and staff who keep the treatment plant running 24/7. This helps keep our waters clean and communities healthy.

This fall and winter, remember to keep trash and fats, oils, and grease out of the toilet. This prevents build up in your pipes and ours and saves time and money on clean up.

Read about all of this and more in our recent email!  

Read the recent Brightwater email.

Sign up for Brightwater emails to stay up to date!

Visit Brightwater’s Public Engagement web page to read past emails, newsletters, and blog stories related to Brightwater. Our 2024 Brightwater newsletter is available in English, Español (Spanish), 中文 (Chinese, Simplified), 正體字 (Chinese, traditional), and Русский (Russian).

Located just north of Woodinville, Brightwater Treatment Plant (Brightwater) began operating in 2011. It is our newest regional wastewater treatment facility and features an educational and event center, natural areas and hiking trails, and public art. Brightwater treats an average of 36 million gallons of wastewater per day from communities in northeast King County and southeast Snohomish County. The facility is nationally recognized for its award-winning design and its consistent compliance with state and federal discharge limits.

 

Aerial view of the Brightwater treatment plant, looking north.  

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