The Environmental Protection Agency has announced it will leave the 2012 Mercury and Air Toxics Standards (MATS) in place but intends to change the way it calculates the costs and benefits of the rule.

The decision is a rejection of an Obama-era ruling that declared it "appropriate and necessary" for EPA to regulate mercury emissions from power plants. In its recent finding, EPA notes that the electric power sector has already invested significant resources that have dramatically reduced mercury emissions at power plants.

"Clean, affordable energy is the priority for electric co-ops," said Dan Chartier, NRECA's regulatory director for environmental policy. "EPA's proposal to recognize the compliance investments made by electric co-ops and provide regulatory certainty is a step in the right direction."

Chartier said retaining the MATS rule is reasonable as utilities continue efforts to reduce emissions of mercury, fine particulate matter, sulfur dioxide, and regional haze. These ongoing compliance commitments, he noted, support business and regulatory certainty for the electric power sector, which operates emission controls on 87.4 gigawatts of coal capacity.

Chartier added that rescinding the rule would not measurably alter the trajectory of coal generation in the U.S.

"Very simply, units retired in the face of the original rule, whether due to the cost of compliance, low natural gas prices or other factors, would likely not be restarted," he said.

"NRECA is continuing to review the proposal and will coordinate with our co-op members to submit comments to EPA as it moves forward to finalize the proposed revisions to this rule."

The proposal will be open for 60 days of public comment after its publication in the Federal Register.