Puget Sound Sewage Spill

Event Year: 2009 Reliability: Confirmed
Country: United States
Industry Type: Water/Waste Water

A sensor on a valve malfunctioned and resulted in the release of 10 milliion gallons of untreated wastewater into Puget Sound.  In the early morning at the West Point plant in Discovery Park, a mishap with a sensor sent the roughly 5-to-1 mixture of stormwater and sewage through a pipe into the shallow waters of the Ellliot Bay.  Ecologists expect short term impacts.  However, the untreated waste would be higher in nitrogen which can contribute to fish-killing low-oxygen zones like the one in Hood Canal.


A faulty sensor is responsible for the release of 10 million gallons of untreated wastewater in Puget Sound.  This spill is being called King County’s worst spill in decades.

Action Description: Treatment plant workers plan to examine their equipment and their responses to try to prevent sewage spills.