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Crews working to resume regular operations after storm disruption at King County's West Point Treatment Plant


King County crews are working to resume normal wastewater treatment operations at the West Point Treatment Plant after an equipment failure during a heavy rainstorm led to a shutdown at the facility early on Thursday, Feb. 9.


Standard wastewater treatment operations are carefully being restored at King County’s West Point Treatment Plant in Seattle following an equipment failure during a heavy rainstorm in the early hours of Thursday, Feb. 9 that led to the plant’s shutdown.

Crews have restored many of the functions at the treatment plant, which went offline following the failure of an effluent pump station at approximately 2 a.m. on Feb. 9.

The pump station went offline at a time when the treatment plant was operating at maximum capacity.

As a result of the equipment failure, portions of the plant were flooded with combined wastewater and stormwater.

Wastewater managers had to divert approximately 260 million gallons of combined stormwater and wastewater to an emergency bypass outfall into Puget Sound while the West Point Treatment Plant was offline. The discharge through the bypass last for about 19 hours and consisted of about 85-90 percent stormwater and about 10-15 percent sewage.

During that time, up to 200 million gallons of wastewater were diverted to other treatment facilities in the regional system for treatment. Flow diversion ended at 10:45 p.m. on Feb. 9.

West Point managers continue their work to restore full operations at this important regional treatment facility. There will be ongoing efforts to evaluate equipment for potential damage and assess the cause of the equipment failure.

Water quality monitoring will continue in potentially affected areas until values have returned to baseline and Public Health reviews the data. Water quality monitoring results will be posted at

King County has notified health and regulatory agencies and is warning people to avoid contact with the water over the next several days as a precaution to protect public health. Beach areas at Discovery Park and some Seattle beachfront parks are posted with warning signs.

This release is also posted on the Department of Natural Resources and Parks website: