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Protecting our waters

Doing our part on rainy days
For questions about the King County Protecting Our Waters Program, please contact John Phillips.

Wastewater Treatment Division
King Street Center
201 S. Jackson St., Suite 505
Seattle, WA 98104-3855

Get Directions to our office location in Seattle, Washington.

Real Time Combined Sewer Overflow (CSO) Notification

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Protecting our Waters by Controlling Combined Sewer Overflows

Important pollution control program nearing the finish line

Protecting Our Waters is King County’s program to prevent pollution caused by excess stormwater in the sewer system on rainy days.

The older parts of King County's wastewater system use a single set of pipes to carry both sewage and rain running off streets and buildings. Most of the time, this polluted water goes to a wastewater treatment plant. But in heavy rains, the pipes can overflow into rivers, lakes, or Puget Sound. Overflow points called “combined sewer overflows” or CSOs are built into the system. CSOs prevent sewer backups into homes and streets.

The water released by CSOs is 10 percent sewage and 90 percent stormwater. CSOs may be harmful to people and animals living in the water because they carry chemicals and disease-causing germs. Since 1979, King County has reduced its overflows by 90 percent and succeeded in keeping more than 2.3 billion gallons of sewage and stormwater out of local waterways.

How do I …

Find out if rain is causing sewage to overflow right now?
Check if a CSO is overflowing before I play in the water
Find out why we have these overflows and the solutions for Protecting Our Waters?
Find out why we have these overflows and the solutions for Protecting Our Waters
 
Learn about projects needed for Protecting Our Waters?
Learn about projects needed for Protecting Our Waters
Learn about RainWise rebates for homeowners?
Learn about RainWise rebates for homeowners
Understand the requirements for Protecting Our Waters?
Understand the requirements for Protecting Our Waters
Locate technical documents & information?
Locate technical documents & information

Related topics

  • Consent decree: In 2013, King County entered a consent decree, which is a legal settlement with the U.S. Department of Justice and EPA that ensures its CSO control plan is completed by 2030 
  • Overflow status: Find out if overflows are happing now.

News releases

For more information