A coal ash pond is shown next to Alabama Power's James M. Barry Electric Generating Plant in Bucks, Alabama.
CNN  — 

The US Environmental Protection Agency announced Tuesday it will begin enforcing regulations that require coal-fired power plants to clean up their coal-ash waste – the toxic byproduct of burning coal to generate electricity.

There are approximately 500 unlined coal-ash ponds in the United States, according to the EPA, which can leak toxins into the surrounding environment, including into freshwater sources that power plants are often situated near.

Regulations on coal-ash ponds were announced in 2015 during the Obama administration, and the Trump administration was criticized by environmental groups for not enforcing the rules. A subsequent ruling on a lawsuit filed by nonprofit environmental group Earthjustice effectively required facilities to start phasing out and closing ash ponds. The deadline to initiate closures was April 2021.

“I’ve seen firsthand how coal ash contamination can hurt people and communities. Coal ash surface impoundments and landfills must operate and close in a manner that protects public health and the environment,” said EPA Administrator Michael S. Regan. “For too long, communities already disproportionately impacted by high levels of pollution have been burdened by improper coal ash disposal.”

The EPA said 57 facilities covered by the regulations, some of which have multiple coal-ash ponds, have requested deadline extensions. It has so far proposed determinations on four – one will be conditionally approved for an extension and three will be denied. The agency is required to take public comment on the proposed determinations for 30 days.

Some coal-ash ponds sit below the water table, the point below which the ground is saturated with water.

EPA is also notifying several coal ash facilities suspected of improper groundwater monitoring and not posting enough information about their obligations to comply with federal regulations. 

Facilities impacted by EPA’s Tuesday announcement are located in New York, Illinois, Michigan, Missouri, Indiana, Ohio, Iowa and Kentucky. 

Lisa Evans, senior counsel at nonprofit Earthjustice, told CNN that it’s encouraging to see the EPA initiate action on these facilities.

“Enforcement of the rule’s provisions is desperately needed, as coal plants have demonstrated they don’t care about polluting water or putting people’s health at risk, and they have taken full advantage of the Trump EPA’s hands-off policy,” Evans told CNN. “The result is nationwide pollution of water at coal plants.”

Evans said this announcement appears to be the first in a longer plan of action.

“More than 100 toxic ponds are potentially sitting in groundwater, and almost all are starting closure, so a definitive statement from EPA that ash ponds cannot close in groundwater is a game changer and will protect the water of millions of Americans,” Evans said.

Coal ash is toxic, containing pollutants including mercury, cadmium, and arsenic that can pollute rivers and poison drinking water. Though the Obama administration took steps in 2015 to regulate it, the rule categorized coal ash as solid waste instead of hazardous waste – largely allowing the utilities to police themselves.

“We’re pretty far down the road on this and we recognize the sense of urgency,” Regan told CNN last year.

EPA’s announcement also alluded to future additional regulations, finalizing a federal permitting program for how companies should safely dispose of coal ash, and establishing regulations for legacy coal ash surface impoundments.

Correction: A previous version of this story included a mislabeled map. This story has been updated.

CNN’s Isabelle Chapman contributed to this report.