Current Status
On March 6, 2023, EPA issued its final rule finding it is “appropriate and necessary” to regulate hazardous air pollutant (HAP) emissions from power plants, which did not get challenged in court. On May 7, 2024, EPA published its final rule regulating HAPs from Coal- and Oil-Fired EGUs based on the Residual Risk and Technology Review (RTR). The rule sets new limits for filterable particulate matter (fPM) for coal- and lignite-fired power plants and mandates that sources use PM Continuous Emissions Monitoring Systems (PM CEMS) to demonstrate compliance. On May 8, 2024, 24 states challenged the final rule in the D.C. Circuit.
Why it Matters
Mercury and Air Toxics Standards (MATS) limit the amount of mercury and other toxic emissions from power plants. Mercury is a powerful neurotoxin that ends up in the water and soil, and concentrates up the food chain, especially in fish. It is particularly dangerous for pregnant women and young children. In response to the Supreme Court’s decision, Michigan v. EPA, EPA had to determine whether it was “appropriate and necessary” to regulate toxic pollution from power plants. The Biden administration confirmed in a final rule that it was appropriate and necessary to regulate mercury emissions from power plants, and that determination was not challenged in court.
Key Resources
MATS, Cost-Benefit Analysis, and the Appropriate and Necessary Finding
Preview: Mercury and Air Toxics Standards (MATS) – EPA Review
Legal Analysis of MATS Rule and MATS Review Proposal
Timeline of Events
OBAMA ADMINISTRATION
Feb. 16, 2012 EPA finalized the Mercury and Air Toxics Standards requiring coal- and oil-fired power plants to achieve the standards by Spring 2016. Industry groups and several states challenge the rule. (lead case) (D.C. Cir.).
Apr. 15, 2014 The D.C. Circuit upheld the rule on all questions presented to the court by the industry and state petitioners who challenged the rule. White Stallion Energy Center v. EPA, 748 F.3d, 1222 (D.C. Cir. 2014).
June 29, 2015 The Supreme Court held that EPA interpreted §7412(n)(1)(A) of the Clean Air Act unreasonably when it “deemed cost irrelevant to the decision to regulate [HAP emissions from] power plants” and remands the rule to the D.C. Circuit to assess how EPA should proceed with additional cost-benefit analyses. The D.C. Circuit sends the MATS back to EPA to determine if the standards are “appropriate and necessary.”
April 25, 2016 EPA published its Supplemental Finding on the costs and benefits of MATS and finds them to be justified in light of the enormous anticipated health benefits. Within hours, opponents sue. Murray Energy v. EPA, No. 16-1127 (D.C. Cir.).
TRUMP ADMINISTRATION
Jan. 31, 2017 Petitioners sought a 45-day extension in the briefing schedule.
Feb. 9, 2017 The D.C. Circuit denied the extension.
April 18, 2017 EPA asked the Court to delay oral arguments, scheduled for May 18, 2017.
April 27, 2017 The D.C. Circuit removed the argument from its calendar, suspending the case indefinitely, and directed EPA to file 90-day status reports.
July 10, 2018 The Edison Electric Institute and several other industry trade groups and unions send a letter to EPA air chief Bill Wehrum asking him to leave the MATS in place and finish the residual risk and technology review “as expeditiously as possible.” The letter also emphasizes that “…all covered plants have implemented the regulations and that pollution controls — where needed — are installed and operating.”
Aug. 24, 2018 Senators Tom Carper (D-Del.) and Lamar Alexander (R-Tenn.) send a letter to acting EPA Administrator Andrew Wheeler urging EPA to retain MATS. The senators explain, “Keeping the current rule in place will provide much-needed certainty for the electric power industry and help protect the health of all Americans.”
Dec. 28, 2018 EPA released a proposal to revise the 2016 Supplemental Cost Finding and Residual Risk and Technology Review for MATS. The proposal would limit consideration of health benefits in regulation. For more information about the impacts of the issues in this proposal, read EELP Executive Director Joe Goffman’s discussion of potential changes EPA could make here.
March 18, 2019 A bipartisan group of six senators sent a letter to EPA Administrator Wheeler, urging him to withdraw the proposal to revise the appropriate and necessary finding and voicing their opposition to any action that could lead to undoing the Mercury and Air Toxics Standards.
March 26, 2019 Several industry trade groups and labor unions sent a letter to EPA air chief Bill Wehrum urging EPA to maintain its 2012 regulations and “…take no action that would jeopardize these investments or the underlying rule.” The letter also suggested that “…EPA should consider the impacts such an action would have on these costs already borne by industry and how the recovery of these sunk costs could be put in jeopardy….”
April 17, 2019 The attorneys general of 21 states submitted comments to EPA opposing its proposal to withdraw the appropriate and necessary finding.
Dec. 31, 2019 EPA’s Science Advisory Board released a draft report that recommends a new risk assessment be completed for the revised Supplemental Cost Finding and Residual Risk and Technology Review and any future mercury regulation. The new risk assessment should include the mercury-related health effects of consuming all fish, going beyond recreationally caught freshwater fish.
April 9, 2020 EPA finalized rule adjusting emissions limits for four power plants that burn eastern bituminous coal refuse (a form of coal mining waste). The new standards allow the affected plants to release higher amounts of acid gases and SO2 emissions.
April 9, 2020 EPA’s Science Advisory Board critiqued EPA’s assessment of the residual risks to human health from pollutants regulated by MATS. The results of EPA’s final assessment (known as the Residual Risk Assessment) will determine whether EPA must set more stringent pollution control requirements for power plants.
May 22, 2020 EPA finalized rule withdrawing the appropriate and necessary finding. EPA also finalizes the residual risk and technology review and determines that after compliance with MATS, the residual risks from power plant hazardous air pollutant emissions are acceptable and the standards should not be tightened.
May/June 2020 Westmoreland Mining Holdings LLC filed a petition for review in the D.C. Circuit challenging the legality of MATS. Many of the parties also moved to intervene in the lawsuit to defend EPA’s decision to not rescind MATS, including power companies, coalitions of states, and coalition of advocacy organizations.Westmoreland Mining Holdings v. EPA, No. 20-1160 (D.C. Cir.). American Academy of Pediatrics v. Andrew Wheeler, No. 20-01221 (D.C. Cir.); Massachusetts v. EPA, No. 20-01265 (D.C. Cir.); Advanced Emissions Solutions v. EPA, No. 20-01266 (D.C. Cir.); Puget Sound Energy v. EPA, No. 20-1271 (D.C. Cir.).
July 31, 2020 The D.C. Circuit suspended (held in abeyance) for 90 days the challenge to EPA’s less stringent acid gases and SO2 limits for power plants burning eastern bituminous coal refuse. The environmental groups requested this hold to give EPA time to respond to their request that the agency reconsider the final rule. Citizens for Pennsylvania’s Future v. EPA, No. 20-1207 (D.C. Cir.).
Aug. 28, 2020 Westmoreland Mining Holdings LLC requested that the D.C. Circuit sever and put on hold its case challenging the legality of MATS. This would allow the cases challenging the reversal of the appropriate and necessary finding to advance separately. The public health and environmental organizations that intervened in the case supported this motion. Westmoreland Mining Holdings v. EPA, No. 20-1160 (D.C. Cir.).
Sep. 28, 2020 The D.C. Circuit granted Westmoreland’s request to sever and put on hold its case challenging the legality of MATS. Westmoreland Mining Holdings v. EPA, No. 20-1160 (D.C. Cir.).
BIDEN ADMINISTRATION
Jan. 20, 2021 President Biden issued an Executive Order directing the EPA Administrator to consider suspending, revising, or rescinding the May 2020 rule reversing the appropriate and necessary finding. EPA had to complete that review by August 2021.
Feb. 12, 2021 EPA filed motions to hold in abeyance several cases challenging EPA’s reversal of the appropriate and necessary finding. The D.C. Circuit granted those motions on Feb. 16, directing EPA to file an abeyance status report on June 16, 2021, and at 120-day intervals thereafter. American Academy of Pediatrics v. Andrew Wheeler, No. 20-01221 (D.C. Cir.); Massachusetts v. EPA, No. 20-01265 (D.C. Cir.); Advanced Emissions Solutions v. EPA, No. 20-01266 (D.C. Cir.); Puget Sound Energy v. EPA, No. 20-1271 (D.C. Cir.).
Jan. 31, 2022 The Biden Administration proposed to reaffirm its 2016 finding that it remains “appropriate and necessary” to regulate HAP emissions from coal-fired power plants and revoke its 2020 finding. EPA also requested comment on specific questions as part of its review of the residual risk and technology review. .
Mar 6, 2023 EPA published the final rule finding it is “appropriate and necessary” to regulate HAP emissions from coal- and oil-fired power plants in the Federal Register.
April 24, 2023 EPA released its proposed residual risk and technology review. For certain emissions standards, EPA proposes more stringent emission limits for existing coal-fired and lignite-fired electric generating units (EGUs) and proposes to update some of compliance requirements. EPA proposed that the more stringent emission limits would apply within three years of the rule’s effective date. Comments will be due 60 days after publication in the Federal Register.
July 13, 2023 EPA issued a final rule revoking the Trump Administration’s Clean Air Act Cost-Benefit Rule that limited the scope of benefits that EPA could consider in its Clean Air Act rulemakings. To learn more about the Trump rule, read our analysis: New Cost-Benefit Rule Hampers EPA’s Ability to Regulate Harmful Air Pollutants.
May 7, 2024 EPA finalized its Residual Risk and Technology Review (RTR) for coal- and oil-fired EGUs. The rule set new limits for filterable particulate matter (fPM) for coal- and lignite-fired power plants and mandates that sources use PM Continuous Emissions Monitoring Systems (PM CEMS) to demonstrate compliance.
May/June 2024 North Dakota and 23 states filed a petition in the D.C. Circuit challenging the new MATS. Several additional industry organizations filed challenges. States and environmental and public health organizations intervened in support of EPA’s final rule. North Dakota, et al v. EPA, Docket No. 24-1119 (May 8, 2024).
June 7, 2024 State petitioners filed a motion to stay the final MATS rule, including: ND, WV, AK, AR, GA, ID, IN, IA, KS, KY, LA, MS, MO, MT, NE, OK, SC, SD, TN, TX, UT, VA, and WY. June 14, 2024 The D.C. Circuit issued an order setting July 2, 2024 as the deadline for parties to respond to State Petitioners’ motion for stays.
June 21, 2024 Industry challengers joined the State Petitioners’ motion for stay, including: National Rural Electric Cooperative Association, Lignite Energy Council, National Mining Association, Minnkota Power Cooperative, East Kentucky Power Cooperative, Associated Electric Cooperative, Basin Electric Power Cooperative, and Rainbow Energy Center. State of North Dakota v. EPA, Docket No. 24-01119 (D.C. Cir. May 8, 2024).