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Crews respond to overflow at King County’s South Mercer Pump Station


King County's South Mercer Pump Station is operating normally following a mechanical failure that caused a 20-minute overflow during a power outage on Sunday, Jan. 8.


Sewer utility crews responded late Sunday morning, Jan. 8, to an overflow from King County’s South Mercer Pump Station.

An undetermined quantity of wastewater overflowed into Lake Washington for about 20 minutes from the station, which is located at the intersection of East Mercer Way and Southeast 72nd Street on Mercer Island.

The overflow was caused by a mechanical problem during a power outage, and the issue was corrected shortly after by a worker who reported to the site. The station is now operating normally, and operations crews will continue to monitor the facility.

King County will notify health and regulatory agencies, sample water quality and post signs warning people to avoid contact with the water over the next several days as a precaution to protect public health.

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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 districts and more than 1.7 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 50 years.