The Environmental Protection Agency on Friday announced the first-ever national regulations for the safe disposal of coal ash from coal-fired power plants, a move meant to protect the public from disasters like the 2008 Tennessee breach that spilled more than 5 million cubic yards of toxic ash that contaminated a nearby river and surrounding communities.

Coal ash is a toxic byproduct of burning coal, and until now it could be stored in open, earthen pits. This led to groundwater contamination and ash blowing through the air into neighboring communities. The ash can include arsenic, mercury and lead and can raise the risk of cancer, neurological problems and other illnesses.

“This is a huge step forward,” EPA Administrator Gina McCarthy said Friday in a conference call with reporters. “This is the first time we have had federal standards in place to ensure coal ash is properly disposed of and managed.”

There were previously no national standards in place to regulate the disposal of coal ash, but a 2012 lawsuit by environmental groups and a Native American tribe against the EPA changed that. That lawsuit was settled in January, and gave the government a deadline of Dec. 19 to finalize new federal regulations.

When asked why such regulations were not implemented years ago, EPA officials said that they had taken all measures authorized by Congress — and that it was only recent spills in Tennessee and elsewhere that had raised the matter to national concern.

“We now have the information in hand that tells us the risks,” McCarthy said.

“The most immediate thing for us is corrective action,” EPA Assistant Administrator for the Office of Solid Waste and Emergency said in the conference call. “In addition they will have to put all these engineering measures to prevent contamination … and putting in a long-term monitoring program.”

“These [new rules] are designed to prevent catastrophic failure by setting structural requirements for new and existing impoundments,” McCarthy said in Friday’s conference. “It restricts the location of new surface impoundments and landfills so that they are not built in sensitive areas like wetlands or earthquake zones. They must be designed with liners to prevent groundwater pollution, and this rule also protects communities from windblown coal ash.”

EPA officials developed the rules over the past months after a review of more than 450,000 public comments, a risk assessment based on studying more than 500 impoundments, and meetings with the public and nongovernmental organizations to gather opinions and advice, McCarthy said.

The new regulations require groundwater monitoring systems that will let the public check each utility’s compliance online. The EPA will not enforce compliance; instead, each state will have to craft and enforce its own rules, with the federal standards as a baseline.

“The question is how do we make sure the utilities are complying,” McCarthy said. “First, we are requiring public reporting … and that will open utilities up to liability and will also allow public citizens to sue if they are not complying.”