A Seattle City Light power outage is being blamed for an unauthorized discharge of three million gallons of untreated wastewater at the West Point Wastewater Treatment Plant early Friday morning.

“We were able to stem the overflow within 27 minutes, so the plant actually operated the way it was supposed to, and an emergency bypass started pumping out water to prevent a flood in the treatment plant,” said King County Wastewater Division spokesperson Marie Fiore. “It’s then pumped out into the Puget Sound through an overflow there, so it doesn’t back up into the plant itself.”

Fiore said it was determined that 80 percent of the discharge was stormwater while the other 20 percent was untreated sewage.

In response to the untreated wastewater discharge, King County’s health department has closed a number of affected beaches, including at Discovery Park, Carkeek Park, the Elliott Bay Marina, Magnolia Tidelands Park and Terminal 91.

The Washington Department of Ecology fined King County $361,000 and ordered that improvements be made at West Point following a plant failure on Feb. 9, 2017 that resulted in untreated wastewater entering Puget Sound. It was the largest fine Ecology had imposed on a publicly owned wastewater treatment plant at the time.

“Many improvements were made since then,” Fiore said, “and as a result that’s why the response time in order to get [the plant] back online was only 27 minutes.”

Ecology spokesperson Colleen Keltz said the county reported the unauthorized discharge to the agency, and the event remains under investigation. The county should have a full report to Ecology regarding the discharge sometime next week, she said, as required under the state’s water quality permit for the facility in the event of an unauthorized discharge investigation.

King County employees were out collecting water samples on Friday morning, according to a new release.

“According to an analysis from Seattle City Light, 55 percent of the disruptions at West Point over the last 17 years were caused by malfunctioning electrical facilities,” the release states. “King County has raised concerns about power reliability. A 2017 letter from Department of Natural Resources and Parks to Seattle City Light identified 104 power failures to West Point from 2001 to 2017.”

The July 19 outage, which affected 10,200 City Light customers, was caused when an insulator released electricity due to rain and environmental contaminants, which then started a fire on the upper cross arm of a double-gang pole at West Nickerson Street and 14th Avenue West, according to City Light spokesperson Julie Moore. The pole broke off and the upper wires struck lower wires, which caused arcing that locked out two feeders, Moore tells Queen Anne News. Affected neighborhoods included North Queen Anne, Magnolia, Interbay, Fremont and Ballard. Around 180 customers in the immediate area where the pole went down were still without power as of 4:30 p.m. Friday.

Fiore confirmed West Point does have emergency generators, adding there was no equipment failure at the plant. Ecology’s news release states “backup pumping systems failed during power disruptions at the plant.”