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South Treatment Plant

Find information and facts about South Treatment Plant located in Renton, including the treatment process, capital and improvement projects, and visiting the facility and grounds.

October 2023

Thank you for your survey feedback! We appreciate all the responses we received on the South Treatment Plant Near Neighbor Survey and are reviewing your feedback. We will use the survey results to give you information that matters to you and your community. Stay tuned for an update on the survey results later this summer. 

Want to learn about our wet weather preparation, read here: Ready for the Next Rainy Season? The Work to Shore Up Clean Water Systems Begins Now. (Clean Water stories)

View the Winter 2023 newsletter to learn more about how South Plant protects public health and the environment, turns waste into valuable resources, and offers education and training programs to the community.

Aerial picture of south treatment plant

Aerial view of South Treatment Plant in Renton.

Located in Renton, South Treatment Plant (South Plant) began operating in 1965. South Plant features a 1.5-acre demonstration farm, CitySoil, that produces more than 5,000 pounds of food for a local foodbank. South Plant is our most visited facility, hosting robust on-site educational programming for school groups and plant tours. The facility is also host to a septage disposal facility for commercial haulers. South Plant treats an average of 90 million gallons of wastewater per day from communities in Auburn, Bellevue, Issaquah, Kent, Renton, and Sammamish.

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