The White House is preparing to reverse regulations covering mercury emissions, the latest move in President Donald Trump’s steady rollback of Obama-era environmental rules.

The Environmental Protection Agency has prepared and delivered a legal proposal to the White House that would rollback regulations pertaining to mercury, a toxic chemical that is emitted from coal-fired power plants. The administration plans to weaken this rule by changing they way officials analyze its costs and benefits.

First established in 2011 by the Obama administration, the Mercury and Air Toxics Standards (MATS) finds the EPA must factor in additional “co-benfits” when evaluating a regulation’s cost compared to its expected health benefits. The Obama White House was able to justify expensive regulation to the coal industry by adding additional health benefits to its cost-and-analysis evaluation.

“The MATS Rule was an egregious example of the Obama administration’s indifference toward required cost benefit analysis,” EPA spokesman John Konkus told The Washington Post. “EPA knows these issues are of importance to the regulated community and the public at large and is committed to a thoughtful and transparent regulatory process in addressing them.”

The Obama administration originally found that forcing coal-fired plants to use the mercury control technology would cost an estimated $9.6 billion a year — the most expensive clean air regulation. This cost was far higher than the expected annual health savings of $6 million. However, the administration was able to rack up these health saving numbers by enabling the MATS Rule, with co-benefits adding another $80 billion, according to The New York Times.

The Trump administration’s new evaluation eliminates this “co-benefit” factor, sharply reducing official health savings of implementing the mercury rule.

Environmental advocacy groups are attacking the expected rollback and have pledged to take the issue to court.

“What [acting EPA administrator Andrew] Wheeler and [EPA air office head Bill] Wehrum are pursuing — the fraudulent denial of real-world benefits from clean air and climate safeguards — is the unholy grail of EPA haters and polluting industry lobbyists for decades,” stated John Walke, an attorney for the Natural Resources Defense Council.

The mercury rule change is just the latest in a growing list of environmental regulation rollbacks by the Trump administration. The White House in September rescinded a methane rule and slapped down incoming train regulation — both established under the Obama administration.

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This article originally appeared in The Daily Caller