Twenty-One AGs Filed Comments Opposing EPA’s Proposal to Revisit Legal Foundation for Mercury and Air Toxics Standards

APRIL 17, 2019

Massachusetts Attorney General Maura Healey led a coalition of 21 state attorneys general in filing comments opposing the Environmental Protection Agency’s (EPA) proposal to reverse its finding that regulations on emissions of hazardous air pollutants from fossil-fuel fired power plants — commonly known as Mercury and Air Toxics Standards (MATS) — are appropriate and necessary under the Clean Air Act. The proposal, if finalized, would undermine the legal foundation of the MATS rule, which since 2012 has yielded an 86 percent reduction in power plant mercury reductions, as well as massive reductions in other hazardous air pollutants. In their comments, the attorneys general questioned the EPA’s assertion that the agency should have ignored the co-benefits of reducing harmful particulates when calculating the rule’s costs and benefits, noting that this change goes against decades of established regulatory precedent. The attorneys general also emphasized that the EPA’s attempt to ignore human health co-benefits from the rule’s reduction of harmful particulates is arbitrary and capricious, and called the agency’s attempt to revisit prior findings “an improper attempt by the EPA to evade clear statutory limitations on its authority.”