A million-gallon coal ash wastewater spill in Minnesota is being investigated by state and federal regulators.

The State Pollution Control Agency says it began at Minnesota Power’s Energy Center in Cohasset, near Grand Rapids.

“It is abnormal for us to have one of this large volume,” says Josh Skelton, Chief Operating Officer of Minnesota Power. “Its uniqueness is that it was underground, hard to detect.”

The Duluth-based utility says a loss of pressure in an underground plastic pipe on Tuesday morning alerted staffers that something was wrong.

The pipeline transfers wastewater from an inactive coal ash pond to the plant for reuse.

Crews later found a crack — and water where it shouldn’t be.

“They noticed an accumulation of water and did a further investigation, noticed that water was making its way into a woodland area, ultimately through Black Water Creek, with potential impacts to Black Water Lake,” Skelton explains.

Workers took action to contain the leak as soon as it was detected, the company says.

The plant is not far from the lake.

Some of those million gallons spilled over land, but it’s unknown how much got into the lake itself.
  
“It’s potentially a pretty significant deal,” notes Trevor Russell, the Water Program director with Friends of the Mississippi River. “A million gallons of anything is a lot.”
  
Russell says he’s worried about the environmental impact of such a large spill. 

“We’re concerned a spill of this magnitude may impact the Mississippi River, both in the immediate area and downstream,” he declares. “The longer these contaminants stay in the water, the more rapidly they diffuse, and more likely they are to work their way up to the aquatic food chain.”

Minnesota Power says there’s no visual plume of any pollutants but that there will be chemical testing and analysis to see how nearby waterways may have been affected.

“We believe there’s minimal solids there,” Skelton says. “Things that we would look for would be any heavy metals or anything that contains sulfate, the impacts you don’t normally see.”

Minnesota Power says it’s unknown how long that pipeline had been leaking — that’s all part of the investigation.

The company says its already installed earthen berms, booms and silk fences in waterways near the plant.

“We want to minimize any impacts,” Skelton says. “We want to be stewards of the environment, so we’re working hard to minimize those.”

In a statement, the MPCA says staffers ‘continue to investigate and work with the company, the U.S. EPA, and cleanup contractors to assess the situation and determine strategies to minimize impacts to the creek and the lake.’

There’s no timeline on a cleanup or how long the investigation will take.

Friends of the Mississippi River says it’s watching all of this closely because waters from Black Water Lake feed into the river.

“They will almost certainly have to install additional monitoring equipment at the site, to make sure we get a full picture of how much continents there are in the lake and moving through the aquatic ecosystem,” Russell says. “A spill like this, while identified early, contained and in the process of cleanup, can still pose long-term risks to the health of the Mississippi River and its wildlife.”