The Washington Department of Ecology is investigating sewage treatment failures at King County’s two largest sewage treatment plants. The following is the latest information Ecology has on the unauthorized discharges at the West Point Wastewater Treatment Plant and Renton Wastewater Treatment Plant.
Early this morning, the West Point Wastewater Treatment Plant released an estimated 3 million gallons of untreated sewage for approximately 27 minutes, after backup pumping systems failed during power disruptions at the plant. The system diverted incoming wastewater to an emergency outfall near North Beach in Discovery Park.
On July 18, there was a different power failure at the county’s Renton Wastewater Treatment Plant, resulting in potentially limited disinfection of treated wastewater. This limited disinfection lasted approximately 50 minutes. The Renton plant discharges into Puget Sound, about two miles offshore, northwest of Duwamish Head in Seattle.
Ecology is investigating both incidents as unauthorized discharges that would violate the state’s water quality permits for the facilities. The county reported the incidents to Ecology. Ecology anticipates taking necessary enforcement actions after its full investigation.
The release of sewage into Puget Sound has prompted local health departments to issue several beach closures. Ecology keeps a list of current beach closures online. We advise the public to check with their local health departments for beach closure updates.