King County quickly responds to wastewater overflow in Seattle

King County's wastewater treatment system is operating normally again after a brief blockage caused a wastewater overflow Monday morning in southwest Seattle.

Facilities inspection staff are on site to complete clean-up of the spill at the West Michigan Regulator Station, 6769 W. Marginal Way S. in Seattle. The spill was likely caused by a blockage in the trunk line that transports untreated wastewater to a treatment plant.

Because of the blockage, untreated wastewater was discharged into the Duwamish River for approximately five hours this morning. The volume of the spill has been estimated at about 56,000 gallons.

To protect public health, the area was posted and a clean-up plan put into place. King County Environmental Laboratory staff took water samples at the water body, and public health and regulatory agencies were notified.

Related information

King County's Combined Sewer Overflow Control Program

King County Wastewater Treatment