E.P.A. to Tighten Limits on Mercury and Other Pollutants From Power Plants

“By presenting all of those rules at the same time to the industry,” Mr. Regan said at an oil and gas conference last year, “the industry gets a chance to take a look at this suite of rules all at once and say, ‘Is it worth doubling down in investments in this current facility? Or should we look at that cost and say now it’s time to pivot and invest in a clean energy future?’”

On Wednesday, Mr. Regan said the new rule would ensure “historic protections” for communities located near power plants. Known as fenceline communities, they are typically home to low-income people of color who suffer from elevated rates of asthma, cancer and other health effects. The Biden administration has made it a priority to address the disproportionate environmental burdens carried by such communities.

The proposal drew criticism from Republicans and the coal industry.

Michelle Bloodworth, president and chief executive of America’s Power, a trade group that advocates for coal-powered electricity, said the industry is concerned that the combined effect of E.P.A.’s regulations will lead to premature retirements of coal plants. The industry group has argued if coal plants shutter too quickly it will hurt the reliability of the electricity grid.

Senator Shelley Moore Capito, Republican of West Virginia, said the Biden administration “continues to wage war on coal” with the regulation. Ms. Capito called the regulation unnecessary and said that it “put politics over sound policy.”

Democrats praised the proposal and said it will lead to health improvements nationwide.

“The Mercury and Air Toxics Standards continue to be a remarkable, cost-effective success in reducing mercury and other toxic air pollution,” Senator Tom Carper, Democrat of Delaware and chairman of the Senate Committee on Environment and Public Works, said in a statement. He said the new rule “will help save lives.”

The E.P.A. estimated that the health benefits over the lifetime of the rule would be between $2.4 billion and $3 billion, from the prevention of deaths or hospitalizations for respiratory and cardiovascular disease. The agency put the estimated cost to the industry of complying with the rule at between $230 million and $300 million.

“Childhood exposure to mercury has very profound health effects,” said Matthew Davis, a vice president of federal policy at the League of Conservation Voters and a former E.P.A. official whose research underpinned the first rules cutting mercury emissions from coal power plants. He called the proposed rule significant.