Montana coal ash pollution cleanup gets state approval

BILLINGS, Mont. (AP) — Montana regulators have given conditional approval to plans to inject clean water underground around the city of Colstrip to flush out water reserves polluted by coal ash from the small southwestern community’s namesake power plant, state officials said Wednesday.

Some details are still in the works, but pumping water into the 54 injection wells could begin by next year, said Sara Edinberg, a hydrogeologist with the Montana Department of Environmental Quality.

Leaking ash ponds at the plant operated by Talen Energy have contaminated groundwater in the area with boron, sulfate and other potentially harmful materials.

The ash pond cleanup at Colstrip could cost an estimated $400 million to $700 million and is expected to last decades. It's being carried out under a 2012 legal agreement reached by Talen's predecessor, PPL Montana, and state officials.

Most Colstrip residents and businesses get water from the Yellowstone River. But some ranches rely on the underground water reserves for their livestock.

The cleanup plan covers two of the power plant's four units. Talen is required to post a $107 million bond to ensure the work is completed.

Some of the pollution that’s deepest underground would not be pumped out under the plan approved Tuesday, and instead is expected to naturally decrease in concentration over time.

Talen would monitor the plume of pollution to make sure it does not become a risk to human health or the environment.

If Talen can’t show the plume is decreasing, state officials said they would require additional work to remove the pollution.

Cleanup plans are still pending for the plant's other two units, where the pollution is ongoing and expected to be more complicated to resolve.

“Part of the pond is unlined and will...