DULUTH, Minn.-The U.S. Environmental Protection Agency has announced that it won't require mining companies to prove they have the cash available to clean up future pollution problems, often called financial assurance, despite government reports that show huge legacy cleanup costs to taxpayers.

The move, announced late Friday, would undo a requirement set in place under the Obama administration to require companies set aside money for future Superfund cleanup costs from unexpected toxic releases long after mines close.

EPA Administrator Scott Pruitt said modern mining practices and state and federal rules already in place adequately address the risks from mines that are currently operating. Requiring mining company cash be set aside for potential future problems "would impose an undue burden on this important sector of the American economy and rural America, where most of these jobs are based," Pruitt said in a statement.

The mining rule was proposed one year ago after a federal judge, in a case won by environmental groups, found that the EPA had been ignoring a provision of the 1980 federal Superfund law. The court ruled that the government indeed should require the up-front money from mining companies considering the long history of legacy cleanup costs.

The EPA faced a Dec. 1 court-imposed deadline to enact the rule.

Environmental groups said the rule was needed because, unlike other financial assurance requirements by state and federal agencies, it would have covered the cleanup costs of spills and accidents involving hazardous substances unforeseen by a mine plan or mine permits.

"These rules are necessary because new mines are added to the Superfund list almost every year," said Bonnie Gestring of Earthworks. "It's galling to see the Trump administration side with industry over the American taxpayer and the many American communities that live with the toxic pollution from these facilities."

"We'll see them back in court," she added.

The Obama-era rule would have applied to so-called "hard-rock mining" including iron ore, gold, silver, copper and nickel.

Minnesota has its own set of mining rules regarding financial assurance for future projects such as the proposed PolyMet copper-nickel mine near Babbitt. Those state requirements would not be impacted by the EPA action. But the state's rules don't apply to unforeseen spills after mines close - only expected mine cleanup and closure costs, so-called mine reclamation.

Paula Maccabee, attorney for the group Water Legacy, said the EPA move could have profound impacts on prospective Minnesota mining projects if they end up polluting after they close.

Minnesota's financial assurance law "handles normal closure of the mine. What it doesn't cover is a toxic spill into the aquifer, or a toxic seep that happens after closure ... those have been dealt with as Superfund issues, so the taxpayers have to pay to clean it up, assuming there's money available," Maccabee said. "What this would have done is made sure there's money available to pay for these mine Superfund sites that pop up long after the company is gone."

The National Mining Association said it welcomed the decision, calling the EPA rule duplicative, unnecessary and "crippling" for mining companies.

"When litigation is used as a tool to attempt to force the government into unnecessary action against an industry, the result is bad policy," said Hal Quinn, the mining association's CEO, in a statement. The Trump administration's action "shows that reason can prevail. Modern, advanced mining practices - coupled with existing state and federal environmental and financial assurance requirements - comprehensively cover the same risks."

The EPA spent $1.1 billion on cleanup work at abandoned hard-rock mining and processing sites across the U.S. from 2010 to 2014, the agency revealed last year. The EPA estimates the backlog of cleanup costs for mines nationwide approaches $54 billion, more than the entire annual Superfund budget.