Update: Discovery Park beaches reopen after water testing confirms safe conditions

January 18, 2021

Summary

Discovery Park beaches were reopened to the public on Jan. 18 after water quality testing showed safe results. The beaches, near West Point Treatment Plant, were closed out of an abundance of caution on Jan. 13 following a stormwater and sewer overflow caused by a power outage during heavy rains. Consecutive days of testing confirmed that the water is safe.

Story

Beaches at Discovery Park in Seattle were reopened to the public on Monday, Jan. 18 following consecutive days of testing that confirmed safe conditions. The beaches were closed out of an abundance of caution Jan. 13 following a stormwater and sewer overflow caused by a power outage during heavy rainfall.

King County reported stormwater and sewer overflows into Puget Sound from West Point Treatment Plant and Richmond Beach pump station early in the morning on Wednesday, Jan. 13, as a result of widespread power outages.

Between midnight and 2 a.m., West Point experienced a series of voltage fluctuations causing in-plant pumping stations to shut down repeatedly. While county field operators worked to get the pumps running consistently, operators were able to mitigate the amount of the overflow by controlling the partial closing of the emergency bypass gate. Equipment and operations worked as needed to protect the plant and employee safety from flooding. All systems were back online within two hours.
 
The emergency caused an estimated 11 million gallons to overflow without treatment into Puget Sound. Approximately 80% was stormwater and 20% was sewage. Large volumes of rainfall throughout the day and into the night exceeded the capacity of the Richmond Beach pump station, and the volume of flow through the Medina Pump Station overwhelmed the station as it transitioned from line power to generator power and back to utility power. These two stations overflowed estimated volumes of 165,000 and 80,600 gallons respectively.

King County notified health and regulatory agencies, and tested water quality and posted signs at beaches advising people to avoid contact with the water as a precaution to protect public health.

King County operates 48 pump stations and 25 regulator stations. Crews worked throughout the night to make sure they operated without incident. A total of 17 pump stations had to run on generator power throughout the storm before returning to utility power.

FOR MORE INFORMATION, CONTACT:
Marie Fiore, 206-263-0284 or mfiore@kingcounty.gov

About the King County Wastewater Treatment Division
King County’s Wastewater Treatment Division protects public health and enhances the environment by collecting and treating wastewater while recycling valuable resources for the Puget Sound region. The division provides wastewater treatment services to 17 cities, 17 local sewer districts and more than 1.8 million residents across a 420-square-mile area in King, Snohomish and Pierce counties.