Fast action stops sewage overflow near Woodinville

Cleanup under way, flows rerouted while crews complete repairs

Employees with King County’s Wastewater Treatment Division worked quickly to stop a sewage overflow that occurred near the 15900 block of Woodinville-Redmond Road shortly after 4 p.m. on Thursday.

It’s estimated that 325,000 gallons of sewage overflowed for 18 minutes through a manhole connected to King County’s North Creek Forcemain into a culvert between the road and Burlington Northern Railroad right-of-way. The culvert likely flows to the Sammamish River.

To stop the leak, crews temporarily shut down the North Creek Pump Station in Bothell and redirected the flows to West Point Treatment Plant in Seattle.
Normally, the forcemain sends wastewater from North Creek to the York Pump Station in Redmond and eventually to the South Treatment Plant in Renton.

The overflow occurred when a 12-inch cap blew off of an access shaft on the forcemain. The cause of the cap failure is under investigation, and crews will continue repairs today. The system is again operating normally.

County employees notified health and regulatory agencies about the overflow and took water quality samples in the Sammamish River. Cleanup crews will likely use vactor trucks to remove debris.