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King County restores full wastewater operations following system disruptions during record rainstorm

Summary

King County wastewater crews quickly restored full operation at a wet weather treatment station in north Seattle during Tuesday’s record rainfall, while disinfected stormwater and wastewater flows were temporarily diverted from South Treatment Plant in Renton to a deepwater outfall in Puget Sound during the storm.

News

King County’s wastewater treatment system is operating normally following disruptions at two facilities during record rainfall Tuesday.

South Treatment Plant in Renton bypassed partially treated flows during the height of the storm, which dropped more than 5 inches of rain in some parts of King County. Approximately 8 million gallons of stormwater and wastewater received primary treatment and disinfection but not secondary treatment before being discharged 10,000 feet offshore into central Puget Sound through an outfall on the bottom of the sound.

The disinfectant system at King County’s Carkeek Combined Sewer Overflow Treatment Facility in northwest Seattle malfunctioned and intermittently released non-disinfected wastewater during the peak of the storm, which dumped nearly four inches of rain in 24 hours. Responding King County crews promptly diagnosed and repaired the equipment.

The Washington State Department of Ecology was informed of both incidents, and Public Health – Seattle & King County has determined no additional measures such as water sampling or beach closures are needed to protect public health.

As a general health precaution, people should avoid entering local waterbodies for 48 hours following a storm.

The regional wastewater system overall operated well throughout the storm, including the county’s other main treatment plants at West Point in Seattle and Brightwater in Woodinville. The Georgetown Wet Weather Treatment Station, operating in its second year, came online during the storm to protect the Duwamish River and Puget Sound and treated 21 million gallons of polluted water over the course of the two-day storm.

“Our employees worked hard to manage an urgent and complex situation, and all the preparation leading up to this event and the winter storm season paid real dividends,” said Wastewater Treatment Division Director Kamuron Gurol. “These big storms offer opportunities to learn from and improve our operations, helping us to be even better prepared for future events.”

Related

Quote

Our employees worked hard to manage an urgent and complex situation, and all the preparation leading up to this event and the winter storm season paid real dividends. These big storm events offer opportunities to learn from and improve our operations, helping us to be even better prepared for future events. 

Kamuron Gurol Wastewater Treatment Division Director

Contact

Alison Hawkes, King County Wastewater Treatment Division, 206-898-0947

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