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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

How to report sewer odor complaints

  • Try to locate the source of the odor. Odors could come from local sewers or King County’s system. Many King County sewer manholes have "METRO" on the lid.
  • Report the odor as soon as possible. Give the location and the time it occurred. This information will help locate the odor and investigation.
  • For odors occurring in homes, businesses and local sewer pipes and storm drains, call your local sewer agency. The phone number to your local agency can be found in your sewer bill.
  • For odors that can't be specifically located, call the closest King County treatment plant's Odor Control Hotline for assistance. 

King County is committed to odor control. However, we cannot guarantee that there will be no odors in our existing system. Occasionally, equipment will need to be shut down for clean up, preventive maintenance or repairs. Please call the odor hotline if you experience odors, and we will do everything we can to restore our high level of odor control.

How to contact us

Brightwater Treatment Plant
(includes Influent Pump Station at N Creek Parkway & NE 19th St, Bothell)
24-hour Odor Control Hotline: 206-263-9500

West Point Treatment Plant
24-hour Odor Control Hotline: 206-263-3801

South Treatment Plant
(includes Carnation and Vashon Plants)
24-hour Odor Control Hotline: 206-263-1760

Odor control hotlines
King County Wastewater Odor Control Hotline
(PDF)

 Many King County sewer manholes have 'METRO' on the lid.
Try to locate the source of the odor. Odors could come from local sewers or King County’s system. Many King County sewer manholes have "METRO" on the lid.

News releases

Other agency contacts

  • Puget Sound Clean Air Agency: 206-343-8800
  • To identify and contact your local sewer agency, check your sewer bill.

Tips for reducing household sewer odors

  • The “p” trap under every sink, tub and floor drain is a water barrier that keeps sewer odors from coming back into your house. Normal use will keep the “p” traps full of water.
  • Don’t make any plumbing hook-up straight into the house side sewer—always install a “p” trap.
  • Periodically run water through drains that aren’t used often, such as floor or garage drains or utility sinks.
  • Make sure all plumbing vents go outside the house. Standard plumbing per code will ensure proper venting.

sink
After water drains from a sink or tub, the “p” trap remains filled, thus preventing gases from entering your home.