The EPA on Monday proposed to make it easier for power companies to dispose of the toxic residues from burning coal, building on other steps the agency has already taken to rewrite Obama-era rules for coal ash pollution.

The EPA’s actions would unwind some of the requirements for treating toxic wastewater and ash that coal power plants discharge that were set in that 2015 rule, which implemented the first federal limits on the levels of toxic metals that can be discharged in wastewater from power plants, and required companies to use updated technology to prevent such pollution.

Separately, the EPA is working on broader regulations to address other parts of the Obama administration rule.

The EPA at the time estimated the 2015 rule would “reduce the amount of toxic metals, nutrients, and other pollutants that steam electric power plants are allowed to discharge by 1.4 billion pounds and reduce water withdrawal by 57 billion gallons.”

However power companies that burn coal, such as AES Corp. of Arlington, Va., and utility trade associations like Utility Solid Waste Activities Group, which represents several power companies, have said the rules were too stringent and raised their operational costs.

The EPA said on Monday the proposed revisions would save coal-burning industries more than $175 million a year.

The agency said it’s making “several planned revisions to provide a clear and stable regulatory framework for coal ash management and disposal” and address issues raised in “litigation, legislation, petitions for reconsideration, and rule implementation.”

The changes, the EPA said, would provide “regulatory clarity and flexibility” for companies, but environmental advocates instead accused the administration of putting industry profits ahead of public health.

Coal ash is known to contain several heavy metals and other toxins including arsenic, mercury and cadmium that have been linked to a myriad of health problems. Some of it is stored in dry form or as wet slurry in ponds. It can also be used as a substitute for soil or as fill material in construction.

“It is outrageous that Trump’s team is so beholden to polluters that they are willing to let power plants continue to dump lead, mercury, chromium and other dangerous chemicals into our water supply to preserve every last cent of their profits,” said Thom Cmar, deputy managing attorney of Earthjustice’s Coal Program.

Other rules

The EPA has proposed separate rules to lift limitations placed by the Obama administration on the amount of coal ash that can be used in certain types of construction. The agency also proposed delaying deadlines for the closure of some unlined coal ash ponds that the Obama administration had asked companies to shut down because they didn’t meet the agency’s safety standards.

Patrick Morrisey, attorney general for West Virginia, which has historically relied heavily on coal for its economy, said the changes will protect coal mining and the livelihoods of those who depend on the industry.

“The proposed regulations will improve the regulatory burden on the coal industry and lower the cost of electricity for West Virginians,” he said.

Catastrophic coal ash spills in recent years have drawn attention to the dangers of coal ash, the disposal of which was largely unregulated for decades.

A coal ash slurry pond at a Tennessee Valley Authority plant in Kingston, Tenn., overflowed in 2008, releasing 1.1 billion gallons of slurry. The flood of ash leveled homes and covered about half a mile of land, leaving behind $1.2 billion in cleanup costs. That disaster prompted the Obama administration to write the rules it completed in 2015.

In 2014, a Duke Energy plant in North Carolina released millions of liquid ash from a shuttered plant. And last year, Hurricane Florence triggered the closure of another Duke plant — the L.V. Sutton station — after the breach of its coal ash stockpile. Slurry there seeped into the Cape Fear River.

Betsy Southerland, who as director of the EPA’s office of water under the Obama administration helped write the rules, said the agency “documented that coal-fired power plants discharge over 1 billion pounds of pollutants every year into 4,000 miles of rivers, contaminating the drinking water and fisheries of 2.7 million” people.

A study by the groups Environmental Integrity Project and Earthjustice released in March found 91 percent of U.S. coal-fired plants that must test their groundwater have unsafe groundwater levels.

About 6 million people live within three miles of a coal-fired plant and those populations are disproportionately people of color and lower-income communities, according to Mustafa Santiago Ali, former director of the EPA’s Office of Environmental Justice.

“The rule announced today puts millions of people’s drinking water in jeopardy, streams, rivers and even private wells are in the crosshairs of this pollution and when tragedy strikes from a flood, hurricane or a breach from an unlined coal ash pit or pond everyday citizens are left with contaminated water, and increasing water cleanup costs that are passed on to them,” Santiago Ali said.

A 60-day comment period on the proposed rule will commence after its publication on the Federal Register.

The EPA’s actions would unwind some requirements set by the Obama administration for treating toxic wastewater and ash that coal power plants.