BILLINGS, Mont. (AP) — The Trump administration said Tuesday that it won't require electric utilities to show they have money to clean up hazardous spills from power plants despite a history of toxic coal ash releases contaminating rivers and aquifers.

Environmental Protection Agency officials said Tuesday that modern industry practices and recently enacted regulations are sufficient to shield taxpayers from potential cleanup costs.

The finding comes after the EPA last year reversed a related proposal under President Barack Obama that would have imposed new financial requirements on the hardrock mining industry.

In both cases, industry lobbyists pushed back against requirements that could have meant higher costs for companies.

The Associated Press reported last year that major utilities across the nation have found evidence of groundwater contamination at landfills and ponds used for decades as dumping grounds for coal ash.

Heightened levels of pollutants — including arsenic and radium in some cases — were documented at plants in numerous states, from Virginia and Montana to Alaska.

Utilities and other companies in 2017 produced more than 111 million tons (101 million metric tons) of coal ash, primarily from burning the fuel for power generation, according to the American Coal Ash Association. Much of the ash is recycled or used for industrial purposes such as concrete additives, but huge volumes end up in long-term storage.

Coal ash disposal went largely unregulated until a 2008 spill at a Tennessee Valley Authority power plant in Kingston, Tennessee. A containment dike burst and flooding covered less than half a square mile (nearly 1.2 square kilometers), dumped waste into two nearby rivers, destroyed homes and brought national attention to the issue.

In 2014, an estimated 39,000 tons (35,380 metric tons) of coal ash spewed into the Dan River after a drainage pipe running below a waste dump collapsed at a Duke Energy plant in Eden, North Carolina. The toxic sludge turned the river gray for more than 70 miles (112 kilometers).

Those accidents helped spur new EPA regulations in 2015 that were intended to increase oversight of the industry.

Under Trump, the EPA is in the process of revising the 2015 coal ash rules. Attorney Lisa Evans with the environmental group Earthjustice said that could undermine efforts to protect against pollution.

"EPA tried hard to justify this reckless outcome, but its reasoning will make sense only to the coal industry," Evans said.

EPA officials did not respond to a request for an interview. They said in Tuesday's announcement that the new rules "have materially reduced risk" of future coal ash spills. The changes included additional monitoring requirements and new standards intended to prevent the failures of dikes that contain coal ash.

"EPA believes that the network of federal and state regulations creates a comprehensive framework that applies to prevent releases that could result in a need for future cleanup," the agency said.

Other pollutants from the power industry, such as PCBs and asbestos, are being addressed through separate regulations, EPA officials said.

Under a court order, the EPA has spent the past several years reviewing the extent to which the nation's most polluting industries cover cleanup costs.

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