EPA Proposes Reinstating Finding Underpinning Mercury and Air Toxics Regulations for Power Plants

On January 31, 2022, the Environmental Protection Agency (EPA) proposed revoking a 2020 rule that stated it was not appropriate and necessary to regulate mercury and air toxics (MATS) from coal- and oil-fired electric utility steam generating units (EGUs) under Clean Air Act (CAA) Section 112. The 2020 rule relied on EPA's rejection of the value of co-benefits — reductions in other pollutants not directly covered by MATS. While the 2020 rule did not rescind a 2012 rule requiring facilities to achieve an emissions rate for MATS consistent with the implementation of the maximum available control technology (MACT), advocates had worried that EPA’s refusal to consider co-benefits would make it more difficult to justify future rulemakings that are protective of public health. EPA’s January 2021 proposed rule would also reaffirm the pre-2020 finding that it is appropriate and necessary to regulate hazardous air pollutant (HAP) emissions from EGUs after considering cost.

EPA is accepting comments until April 11, 2022. EPA is also soliciting information on the performance and cost of new or improved technologies that control HAP emissions, improved methods of operation, and relevant risk-related information.