This month, EPA restored the legal foundation for regulating emissions of mercury and other hazardous air pollutants (HAPs) from coal- and oil-fired power plants under section 112 of the Clean Air Act. EPA reaffirmed that this regulation is appropriate and necessary after weighing its significant public health benefits, costs, and other factors. EPA concluded that the methodology it applied in 2020 is “ill-suited” to the appropriate and necessary determination because, among other reasons, it gave inadequate weight to the significant adverse health and environmental effects of HAPs that cannot be quantified or monetized.
In the final rule, EPA found the regulation would be appropriate even without considering the effects of reducing non-HAP emissions, but adopted a preferred methodology that considers all of the advantages and disadvantages of its decision, including the significant beneficial impacts of reducing non-HAP emissions. Policy Integrity has long recommended that EPA adopt such an approach that considers unquantified and ancillary effects, as is consistent with the best economic practices and the law, including through our comments on the 2022 proposed rule and an amicus brief opposing the 2020 finding. Use of these analytical tools were in the crosshairs of litigation over earlier iterations of the finding, but no challenges were brought against the 2023 Rule.