South Treatment Plant
South Treatment Plant, also referred to as South Plant, is located in Renton and is part of King County's regional wastewater treatment system. South Plant was built in 1965.
January 2023 Update
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.
We want to hear from you: Our goal is to protect public health and the environment while being a good neighbor. Please take the South Treatment Plant Near Neighbor Survey to share your thoughts and experiences with us. We will use the survey results to give you information that matters to you and your community.
South Plant treats wastewater for about 839,000 people living in Auburn, Kent, Renton, Bellevue, Issaquah, and Sammamish, 24 hours a day, 365 days a year. During the dry months, about 90 million gallons per day of wastewater gets treated. About 300 million gallons per day can be treated during the rain/storm season. South Plant also recovers valuable resources from the treatment process, including recycled water, biogas, and Loop biosolids.
24 hour emergency and odor reporting: 206-263-1760
1200 Monster Road S.W.
Renton, WA 98057
If you’d like to receive email or text updates on the South Treatment Plant: