Department of Ecology News Release - Nov. 6, 2019

King County fined for sewer overflow violations

Seattle –

King County will pay $105,500 to the state Department of Ecology and U.S. Environmental Protection Agency (EPA) for violating conditions of its state water quality permit that regulate combined sewer overflows (CSO) from parts of the county’s sewer collection system.

In 2017 and 2018, King County exceeded pollutant limits 18 times at its four wastewater plants that treat CSO discharges. The county also reported one unpermitted overflow during the same period and one instance where the disinfection system at the Elliott West Treatment plant failed in April 2018.

The penalty involves discharges that entered Puget Sound, the Duwamish River, and Elliott Bay. Releases contained bacteria and other pollutants that can make waters unsafe for people and pets.

The violations do not involve the county’s main wastewater treatment plants –  Brightwater, South Plant in Renton, and West Point.

The payments are required under a 2013 legal agreement between the county, Ecology and EPA on controlling overflows from combined sewage lines. Ecology and EPA developed this agreement with the county to reinforce requirements for the county to comply with the state’s CSO regulations by 2030.

Under the legal agreement – and earlier agreed orders with Ecology – the county committed to control CSOs according state regulations. While the county has completed projects to reduce CSO discharges over the last several years, additional work is needed to fully meet state requirements. Ecology expects the county to further reduce discharges as current and future projects come on line. Ecology also expects the county to continue efforts to prevent future violations at its CSO treatment plants.

Combined sewers were historically built with overflow outfalls that can operate during high stormwater flows. State and federal law requires communities to eliminate these overflows except in extreme weather circumstances.

Ecology will receive half of the penalty. Water quality penalty payments to Ecology are placed into the state’s Coastal Protection Fund, which provides grants to public agencies and tribes for water quality restoration projects.

The county may invoke dispute resolution procedures if it believes Ecology and EPA have assessed the penalties incorrectly.


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Contact information

Jeff Zenk
Communications manager
Primary: 360-407-6239 Mobile:
Twitter: ecyseattle