Gasoline spill in sewer system causes partial shutdown of Mendenhall Wastewater Treatment Plant

A gasoline spill in Juneau’s sewer system shut down half of the Mendenhall Wastewater Treatment Plant on Saturday morning. 

Officials have not identified the source of the contamination and are requesting help from the community. 

Chad Gubala is the production and treatment manager at the city’s wastewater utility. He said that they don’t know exactly how much gasoline spilled. 

“It was large enough to affect about half of the Mendenhall treatment plant. We had to shut down and isolate a portion of the plant,” Gubala said. 

He said that gasoline kills the biological agents the city uses to scrub sewage of harmful bacteria and viruses. 

“It essentially killed the bugs that were doing the treatment work in the plant,” he said. “So it would have resulted in a discharge of untreated sewage to the lower Mendenhall River.”

If that had happened, he said that it could have exposed people to fecal matter and affected wildlife in the river and sea. He said it is fortunate the operator caught the spill before untreated sewage was released.

Gubala said that treatment plant staff shut down operations and evacuated as soon as they smelled the gasoline. They searched for signs of spills at gas stations in the Mendenhall Valley and Lemon Creek areas, but did not find the source. He said gasoline is tricky to trace since it evaporates quickly. 

Rachael Krajewski, the state’s on-scene coordinator for spill prevention and response at the Department of Environmental Conservation, said they are still investigating the cause of the spill. 

“We are looking for the community to call and report anything that they may have seen relating to this incident,” she said.

The spill reporting hotline is 1-800-478-9300.

Officials say the spill looks like an isolated incident, and the wastewater treatment plant was back up and running as of Sunday evening.