UPDATE: Power Failure Causes Sewage Overflow into Lake Washington

About 8,000 gallons of sewage overflowed into the storm drain system from a pump station in downtown Kirkland during a power failure Thursday, and some of it spilled into Lake Washington, says a county spokesperson.

Crews in vacuum trucks were able to recover an unknown amount of the sewage from underground pipes between the pump station at Third Street and Park Lane downtown and an emergency outfall in the lake off .

But some sewage did reach the lake, and signs have been posted at the park warning the public as a precaution, said Annie Kolb-Nelson, spokeswoman for King County Parks and Natural Resources.

The overflow lasted 18 minutes, and is not expected to have a significant impact on the lake’s ecology or public health.

“It is, of course, something we take seriously, but the volume overall in the big picture is not a large amount,” Kolb-Nelson said.

The power outage was caused by a surge during routine maintenance just before 9:30 a.m. Thursday, and a backup generator failed to start because of a faulty breaker, she said.

An electrician was called and restored power within 50 minutes.

County staff took water quality samples in the lake and notified health and regulatory agencies about the overflow.

“We’ll know by (Friday) afternoon what the bacteria counts are,” Kolb-Nelson said, adding that the warnings would remain posted until health authorities were sure there were no public health issues.