Twenty-One AGs Challenged EPA Reversal of Mercury and Air Toxics Standards ‘Appropriate and Necessary’ Determination

JULY 20, 2020

Massachusetts Attorney General Maura Healey led a coalition of 21 attorneys general in filing a petition for review of the Environmental Protection Agency’s (EPA) final rule that undercuts the legal basis of the agency’s Mercury and Toxic Air Standards (MATS), which have driven major reductions in emissions of mercury and other toxic heavy metals from coal- and oil-fired power plants. The rule relies on a contorted cost-benefit analysis to justify reversing the EPA’s prior, well-documented finding that the MATS regulations are “appropriate and necessary” under the Clean Air Act. In particular, the final rule grossly under-assessed the direct benefits of reduced mercury emissions—valued at well over $150 billion—and ignored as much as $90 billion in “co-benefits” from reductions in fine particulate pollution (PM 2.5).