King County responds to wastewater overflows caused by Monday’s rainstorm

King County's sewer utility crews responded quickly to three Eastside wastewater overflows that occurred during Monday’s torrential rainstorm.

Wastewater spilled from a manhole cover on North Mercer Island, with highly diluted wastewater spilling into Lake Washington. Crews posted a nearby beach as closed to the public.

An overflow occurred in Medina on Monday. Water volumes into the Medina pump station were more than the system is designed to handle, leading to an overflow of highly diluted wastewater into Lake Washington.

A wastewater line in Kenmore also overflowed Monday because of high volumes, leading to a small spill into the Sammamish River.

Two smaller overflows occurred at Yarrow Bay and Juanita pump stations, when excessive flows overwhelmed the system. Highly diluted wastewater was discharged into Lake Washington via local storm lines.

King County Environmental Laboratory staff took water samples water bodies near all overflow events, and public health and regulatory agencies were notified.

People enjoy clean water and a healthy environment because of King County's wastewater treatment program. The county's Wastewater Treatment Division protects public health and water quality by serving 17 cities, 17 local sewer utilities and more than 1.4 million residents in King, Snohomish and Pierce counties. Formerly called Metro, the regional clean-water agency now operated by King County has been preventing water pollution for more than 40 years.