"Today, the EPA corrected flaws in the 2016 Supplemental Cost Finding for the Mercury and Air Toxic Standards (MATS) for coal- and oil-fired power plants, consistent with a 2015 US Supreme Court decision", Wheeler said in a press release on Thursday.
The EPA Administrator also said the agency completed the Clean Air Act-required residual risk and technology review for MATS.
"Today’s action maintains the mercury emissions standard, and meets the statutory obligation to review the adequacy of those standards", Wheeler said.
The regulation leaves the MATS in existence for now, but opens the way to scrap federal regulation of the emissions, the release said, adding that it also weakens federal regulations on the release of other toxic metals from oil and coal-fired power plants.
The results of the risk and technology review, conducted by the EPA, have shown that emissions of hazardous air pollutants (HAP) have been reduced such that residual risk is at acceptable levels, that there are no developments in HAP emissions controls to achieve further cost-effective reductions beyond the current standards, and no changes to the MATS rule are warranted.