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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

Business center

  • Capacity charge online payment
    You can now pay your sewage treatment capacity charge online. Payments can be made through your checking account (e-check) or by credit card (Visa and Master Cards are accepted).
  • Industrial wastewater discharge permit application
    Prior to discharging industrial waste in to the sewer system, all dischargers who generate and dispose of industrial wastewater must contact the King County Industrial Waste Program for approval to discharge. In most cases potential dischargers will need to submit a wastewater discharge permit application.
  • Septage disposal
    King County provides septage disposal for commercial haulers at the South Treatment Plant, Renton.
  • Consultant Forum 
    Learn about upcoming King County Wastewater Treatment Division projects.
  • Requesting WTD engineering design standards
    These standards have been adopted by King County's Wastewater Treatment Division (WTD). All drawings for WTD projects, whether produced by County employees or by consultants, must comply with these Standards documents.

WTD finances and budget

King County's wastewater utility is entirely funded by the ratepayers who invest in our programs and services through their monthly rate and capacity charge bills.

Doing business with the county

The Procurement and Contract Services Section (PCSS) web site is designed to assist users who do business with King County. The web site provides procurement and contract information for:

  • Construction 
  • A&E and Professional Services 
  • Technical Services 
  • Goods and Services