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West Point Treatment Plant bypassing some flows as storm affects plant still in recovery


Heavy rains early Wednesday morning, Feb. 15, caused a partial bypass of combined wastewater and stormwater flows to Puget Sound at the West Point Treatment Plant. The plant is operating at about 50 percent capacity since a storm last week led to a power failure and flooding in portions of the facility.


Heavy rains overnight on Feb. 15 have filled the combined storm and sewer system that sends flows to King County’s West Point Treatment Plant, exceeding capacity at the plant and resulting in a temporary bypass of combined stormwater and wastewater through an emergency outfall into Puget Sound.

While most of the incoming stormwater and wastewater is being treated at West Point and satellite facilities in King County’s wastewater treatment system, flows are bypassing through the emergency outfall at a rate of approximately 50 million gallons per day.

The stormwater-wastewater bypass began at about 3:30 a.m. on Feb. 15. Flows consist of about 90 percent stormwater and 10 percent untreated sewage. The action is necessary to protect plant workers and West Point’s current level of wastewater treatment.

West Point has been operating at about half of its designed capacity while cleanup and restoration activities continue following the Feb. 9 equipment failure during an intense storm that led to flooding in portions of the plant.

Teams of responders restored reduced primary treatment within a day, and crews have been working to bring the treatment plant up to full capacity. King County crews and contractors continue cleaning the treatment plant and assessing damage to equipment and systems as a result of the Feb. 9 flood.

Water quality monitoring has been ongoing and will continue.  Warning signs are posted at North Beach and South Beach in Discovery Park. 

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.

People should watch for notifications and updates and heed warning signs on beaches. Water quality monitoring results and updates are posted at:

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