Minnesota Power now estimates 5.5 million gallons of ash wastewater leaked at its Boswell Energy Center in Cohasset, Minnesota.

The update on Friday afternoon is that monitoring and sampling indicate increased levels of sulfate and boron in the immediate area where the wastewater entered Blackwater Creek.

Sulfate levels, according to the utility, are below the federal drinking water standard, but higher than the wild rice based standard.

No immediate impacts to fish or aquatic plants have been observed. Mitigation activities will continue through the weekend.

There are plans to excavate affected soils to remove contaminants, and the area was assessed for cultural and tribal resources.

The wastewater is pumped from a pond to the facility for operations. The water is leftover from when they used the wet scrubbing process, which is no longer used.

Employees noticed the pressure was down, and went to check out the pipe.

They found water pooling by the pipe, and had it shut down immediately, according to Chief Operating Officer Josh Skelton. This was around 11:15am on Tuesday, and then they notified the state.

Both MPCA and EPA staff arrived by Tuesday evening.

The staff had to dig down and found the leak underground, where the pipe goes from underground to above ground.

The company will also be working on replacing the pipe, and determining why there was a failure.