The Environmental Protection Agency is overstepping its authority if it continues to enforce Obama administration-era environmental rules for uranium mining, said Sen. John Barrasso, R-Wyo., in a letter to the agency.

Barrasso, chairman of the Senate Environment and Public Works Committee, sent a letter to EPA Administrator Scott Pruitt on Thursday, asking him to take immediate steps to eliminate duplicative environmental regulations requiring ground water monitoring by "in situ" uranium mine operators that inject water into the earth to pump the uranium to processing facilities.

Barrasso said the uranium mining industry is suffering from the lowest production since before nuclear power plants were in operation.

"It is incumbent upon EPA to refrain from imposing regulations that are not technically feasible or are unreasonably burdensome on licensees," Barrasso wrote.

The Nuclear Regulatory Commission already requires the same environmental requirements that the Obama EPA had established for uranium mining last year. The previous administration had re-proposed a new version of the rule before leaving office in January. Barrasso and the NRC see both the new and prior EPA versions of the regulation as unnecessary, an overreach and duplicative.

"I have come to learn that the Nuclear Regulatory Commission (NRC) has had — from this rulemaking’s inception — serious concerns with EPA’s proposals," Barrasso wrote. "I share NRC’s concerns about EPA’s rule and ask that you withdraw the rule."

Barrasso's committee has direct oversight of the EPA and NRC. He told Pruitt that the NRC general counsel issued a memo stating "that if promulgated, the rule would reach beyond EPA’s authority in key areas."

"The rule — rather than setting generally applicable standards — would impose implementation standards," which the law "delegates to the NRC, not EPA," Barrasso wrote. The NRC authorized the general counsel in 2015 "to convey both substantive and jurisdictional concerns to EPA."

In July 2017, NRC filed 25 pages of comments elaborating on its concerns about jurisdictional overreach.

"The comments explain that the NRC and its agreement states 'have been safely, securely, and successfully regulating ISR facilities since the 1970’s.' They state that 'in almost 40 years of operational experience, the NRC staff is aware of no documented instance of an ISR wellfield being the source of contamination of an adjacent or nearby aquifer, or of the non-exempt portion of the same aquifer in which [in situ uranium mining] activities are being conducted,” the letter read.

The Nuclear Regulatory Commission stated that there is “no health or safety justification for [the] rulemaking,” Barrasso wrote in the letter.

"Finally, the comments detail how the rule 'encroaches upon NRC’s jurisdiction, and includes requirements that are not technically feasible or are unreasonably burdensome on ... licensees without providing any equivalent benefit,'” the letter said.