Holiday closure Monday May 28: Most county offices will be closed in observance of Memorial Day.

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: 206-684-1280
Fax: 206-684-1741
Telecommunication device for the deaf (TTY): 711

Get Directions to our office location in Seattle, Washington.

Staff Contacts

Puget Sound shoreline next to the West Point Treatment Plant, Seattle

South Treatment Plant

Welcome to the South Treatment Plant in Renton, Washington.

South Treatment Plant, Renton, WA
South Treatment Plant
(Click image for larger view.)

Service area for the South Treatment Plant
South Treatment Plant service area. View larger version (PDF, 2.1MB).

The plant is part of King County's regional wastewater treatment system that serves more than 1.5 million people and covers 420 square miles in the Puget Sound region. Every day, South Plant cost-effectively treats millions of gallons of wastewater from our homes, offices, schools, agencies, businesses and industries along the east side of Lake Washington from south Snohomish County to north Pierce County.

What's happening at South Plant