From the Document: "In April 2020, the U.S. Environmental Protection Agency (EPA) concluded that limits on hazardous air pollutants (HAPs) from coal- and oil-fired power plants are not 'appropriate and necessary' (A&N) under Clean Air Act (CAA) Section 112(n)(1) ('Reconsideration of Supplemental Finding and Residual Risk and Technology Review,' April 16, 2020). The 2020 A&N rule reversed prior A&N determinations, which led to the 2000 listing of coal- and oil-fired power plants as a major source of HAPs and the 2012 Mercury and Air Toxics Standards (MATS) limiting those HAPs. Notwithstanding the 2020 A&N rule, the 2012 MATS limits remain in effect for power plants because EPA determined that it could not meet the criteria under CAA 112(c)(9) to delist them. Furthermore, the A&N finding does not change the regulatory status of other pollution sources because CAA Section 112(n)(1) applies only to power plants. Some have raised questions about why EPA reversed the A&N finding and how it might affect regulated entities. For example, some power plant owners are concerned the A&N reversal may compromise their ability to recover from ratepayers the costs of installing MATS pollution controls. Others find this unlikely, but legal challenges to the 2020 A&N rule are expected."
CRS In Focus, IF11078
Congressional Research Service: https://crsreports.congress.gov/