HELENA — The Montana Environmental Review Board on Friday rejected a permit to expand a coal mine in the Bull Mountains over concerns about a state agency’s analysis on the long-term effects to the groundwater.
The Montana Environmental Information Center had appealed state regulators’ 2013 decision to issue a permit to Signal Peak Energy for a 7,100-acre expansion of the Bull Mountain Mine near Roundup to reach 110 million tons of mineable coal.
The environmental organization argued the state Department of Environmental Quality’s analysis on whether groundwater outside the mining area would be affected contained errors, and the five-member review board agreed.
“It’s a very important step toward protecting groundwater,” MEIC executive director Anne Hedges said of the board’s decision.
The environmental group said the coal seam that Signal Peak wants to remove is saturated with water that functions as an aquifer and is the water source for wells in the Bull Mountains. If water polluted by mining spread to nearby streams and to the water used by homes and ranches, it would threaten long-term economic and environmental harm, MEIC officials argued.
The agency had concluded, and Signal Peak officials agreed, that water contaminated by mining activities would stay within or very near to the mining boundaries, making the chances remote that outside water sources would be harmed.
However, the DEQ’s analysis stopped 50 years after the completion of mining activities, a timeline that is not supported by state laws or regulations, board member Chris Tweeten said.
“This seems to be an arbitrary figure that was picked by the department,” Tweeten said. “Apparently, from all that appears in the record, there was no mechanism in place to determine whether water quality would be affected outside the mine’s area 75 years down the road.”
MEIC attorney Shiloh Hernandez also argued that it was uncertain whether mine access points called “gate roads” will collapse as planned after mining is completed, which would affect the rate at which the contaminated water would spread over time.
Finally, the board questioned DEQ’s approval of Signal Peak’s plan to ease the effects of the mine by pumping in water from a deeper underground aquifer. Tweeten said state law requires the project be designed to prevent - not mitigate - harm to water outside the mining area, and it wasn’t clear whether pumping in replacement water followed the law.
The board voted 4-1 to vacate the permit and send the matter back to the DEQ to address the problems.
Tweeten was the sole vote against the measure, even though he was the member of the panel to outline the main problems. He said disagreed with the board’s decision to adopt MEIC’s other arguments made in legal filings besides those that had been discussed.
DEQ legal counsel Dana David said he did not have any comment on the decision.