Non-GHG Emission Standards with GHG Co-Benefits

Emissions Standards (NESHAP and NSPS)

This section covers emissions standards promulgated under two Clean Air Act programs: National Emission Standards for Hazardous Air Pollutants (NESHAP) and New Source Performance Standards (NSPS).

Electric Generating Units (EGUs)

National Emission Standards for Hazardous Air Pollutants (NESHAP)

Under section 112 of the Clean Air Act, EPA must establish technology-based standards to control emissions of hazardous air pollutants from certain stationary sources. EPA must review the standards every 8 years and revise them as necessary taking into account any “developments in practices, processes, or control technologies.” This is referred to as the “technology review.”

New Source Performance Standards (NSPS)

Section 111(b) of the Clean Air Act requires EPA to set new source performance standards (NSPS) for new and modified stationary sources of emissions that cause or contribute significantly to air pollution that may reasonably be anticipated to endanger public health or welfare. The NSPS must be based on the “degree of emissions limitation achievable through the application of the best system of emission reduction [BSER] which . . . the Administrator determines has been adequately demonstrated.” 42 U.S.C. § 7411(a)(1).

Once NSPS are established for a particular type of stationary source, EPA must (with limited exception) then adopt emissions guidelines to regulate existing sources of the same type under section 111(d) of the Clean Air Act.  42 U.S.C. § 7411(d). The emissions guidelines are typically implemented by states, which must develop, and have approved by EPA, plans for controlling emissions from existing facilities in the source category. If a state fails to develop a plan, or the state plan is not approved by EPA, a federal plan will apply.

On May 7, 2024, EPA finalized a rule to amend the NESHAP for coal- and oil-fired EGUs. 89 Fed. Reg. 38,508 (May 7, 2024). The rule was promulgated in the same rulemaking where EPA reaffirmed that it is necessary to regulate coal- and oil-fired EGUs under section 112 of the Clean Air Act by revoking the 2020 rule. (See North Dakota v. EPA in “Litigation” below.)

Litigation

Challenge to 2024 NESHAP - North Dakota v. EPA

In May 2024, several state and private parties filed a petition for review of EPA’s NESHAP amendments in the D.C. Circuit Court of Appeals. As of January 19, 2024, the consolidated case has been briefed but oral argument is not yet scheduled.

Biden Administration (2021-2024)

On May 7, 2024, EPA finalized a rule to amend the NESHAP for coal- and oil-fired EGUs. 89 Fed. Reg. 38,508 (May 7, 2024). The rule was promulgated in the same rulemaking where EPA reaffirmed that it is necessary to regulate coal- and oil-fired EGUs under section 112 of the Clean Air Act by revoking the 2020 rule. (See North Dakota v. EPA in “Litigation” below.)

On March 6, 2023, EPA finalized a rule to revoke the 2020 rule that stated it was not appropriate and necessary to regulate mercury and air toxics from coal- and oil-fired EGUs under section 112 of the Clean Air Act. 88 Fed. Reg. 13,956 (Mar. 6, 2023).

First Trump Administration (2017–2020)

On May 22, 2020, EPA published a reconsideration of the April 2016 supplemental cost finding while ensuring that power plants will emit no more mercury to the air than before. 85 Fed. Reg. 31,286 (May 22, 2020). EPA concluded that it is not "appropriate and necessary" to regulate mercury from coal-fired power plants. The decision relies on EPA's rejection of the value of co-benefits—reductions in other pollutants not directly covered by the MATS Rule and a key part of the original cost-benefit calculus. Although EPA did not rescind the MATS Rule, advocates worry that its refusal to consider co-benefits will make it more difficult to justify future rulemakings that are protective of public health. (See American Academy of Pediatrics v. Wheeler in “Litigation” below.)

Obama Administration (2009–2016)

In response to an industry challenge to the MATS Rule (see Michigan v. EPA in “Litigation” below), EPA revised certain aspects of the rule in April 2013 to soften standards for new power plants. 78 Fed. Reg. 24,073 (Apr. 24, 2013). In November 2014, EPA revised certain aspects of the rule pertaining to startup and shutdown standards. In April 2016, EPA issued technical corrections to the rule and supplemental findings. 81 Fed. Reg. 20,172 (Apr. 6, 2016); 81 Fed. Reg. 24,420 (Apr. 25, 2016).

On February 16, 2012, EPA finalized a rule, commonly referred to as the Mercury and Air Toxics Standards (MATS) Rule, setting NESHAP for coal and oil-fired electric utility steam generating units. 77 Fed. Reg. 9,304 (Feb. 16, 2012). As part of the same rulemaking, EPA also finalized NSPS for criteria pollutants (PM, NOx, and SO2) from fossil fuel-fired electric utility, industrial, commercial, and institutional steam generating units. (See Michigan v. EPA in “Litigation” below.)

Litigation

Challenge to 2024 NESHAP - North Dakota v. EPA

In May 2024, several state and private parties filed a petition for review of EPA’s NESHAP amendments in the D.C. Circuit Court of Appeals. As of January 19, 2024, the consolidated case has been briefed but oral argument is not yet scheduled.

Challenge to 2020 Rule - American Academy of Pediatrics v. Wheeler

On June 19, 2020, a coalition of environmental and civil rights groups challenged the "appropriate and necessary" finding in court.

Challenge to MATS Rule - Michigan v. EPA

On June 29, 2015, the Supreme Court ruled that EPA had improperly failed to consider compliance costs at the outset of developing the MATS Rule. Michigan v. EPA, 576 U.S. 743 (2015). The rule remained in effect pending remand to EPA, and in April 2016, EPA issued a supplemental finding considering compliance costs and concluding that the MATS Rule was appropriate and necessary.

Boilers and Heaters

National Emission Standards for Hazardous Air Pollutants (NESHAP)

Under section 112 of the Clean Air Act, EPA must establish technology-based standards to control emissions of hazardous air pollutants from certain stationary sources. EPA must review the standards every 8 years and revise them as necessary taking into account any “developments in practices, processes, or control technologies.” This is referred to as the “technology review.”

On October 6, 2022, EPA published a final rule amending the NESHAP for industrial, commercial, and institutional boilers and process heaters. 87 Fed. Reg. 60,816 (Oct. 6, 2022). The rule is related to standards EPA finalized in 2013, which the D.C. Circuit Court of Appeals later remanded to EPA . 

Biden Administration (2021-2024)

On October 6, 2022, EPA published a final rule amending the NESHAP for industrial, commercial, and institutional boilers and process heaters. 87 Fed. Reg. 60,816 (Oct. 6, 2022). The rule is related to standards EPA finalized in 2013, which the D.C. Circuit Court of Appeals later remanded to EPA .

Obama Administration (2009-2016)

On January 31, 2013, EPA issued a final rule revising its March 2011 rule establishing NESHAP for new and existing industrial, commercial, and institutional boilers and process heaters at major sources of hazardous air pollutants. 78 Fed. Reg. 7,138 (Jan. 31, 2013). As a result of the revisions, facilities classified as major sources of hazardous air pollutants with affected boilers or process heaters will be required to reduce their toxic air emissions.

On March 21, 2011, issued a final rule establishing NESHAP for industrial boilers and commercial and institutional boilers, including coal-fired, oil-fired, and biomass-fired boilers. 76 Fed. Reg. 15,554 (Mar. 21, 2011).

Fuel Facilities

National Emission Standards for Hazardous Air Pollutants (NESHAP)

Under section 112 of the Clean Air Act, EPA must establish technology-based standards to control emissions of hazardous air pollutants from certain stationary sources. EPA must review the standards every 8 years and revise them as necessary taking into account any “developments in practices, processes, or control technologies.” This is referred to as the “technology review.”

New Source Performance Standards (NSPS)

Section 111(b) of the Clean Air Act requires EPA to set new source performance standards (NSPS) for new and modified stationary sources of emissions that cause or contribute significantly to air pollution that may reasonably be anticipated to endanger public health or welfare. The NSPS must be based on the “degree of emissions limitation achievable through the application of the best system of emission reduction [BSER] which . . . the Administrator determines has been adequately demonstrated.” 42 U.S.C. § 7411(a)(1).

Once NSPS are established for a particular type of stationary source, EPA must (with limited exception) then adopt emissions guidelines to regulate existing sources of the same type under section 111(d) of the Clean Air Act.  42 U.S.C. § 7411(d). The emissions guidelines are typically implemented by states, which must develop, and have approved by EPA, plans for controlling emissions from existing facilities in the source category. If a state fails to develop a plan, or the state plan is not approved by EPA, a federal plan will apply.

On May 8, 2024, EPA published a rule announcing final technology reviews for the NESHAP for gasoline distribution facilities and amendments to those standards. 89 Fed. Reg. 39,304 (May 8, 2024). In the same action, EPA also finalized updated NSPS for bulk gasoline terminals. (See International Liquid Terminals Association v. EPA in “Litigation” below.)

Litigation

Challenge to 2024 NESHAP and NSPS - International Liquid Terminals Association v. EPA

In July 2024, two industry parties filed petitions for review of EPA’s May 2024 final rule in the D.C. Circuit Court of Appeals. The consolidated case was held in abeyance in August 2024.

Biden Administration (2021-2024)

On May 8, 2024, EPA published a rule announcing final technology reviews for the NESHAP for gasoline distribution facilities and amendments to those standards. 89 Fed. Reg. 39,304 (May 8, 2024). In the same action, EPA also finalized updated NSPS for bulk gasoline terminals. (See International Liquid Terminals Association v. EPA in “Litigation” below.)

Litigation

Challenge to 2024 NESHAP and NSPS - International Liquid Terminals Association v. EPA

In July 2024, two industry parties filed petitions for review of EPA’s May 2024 final rule in the D.C. Circuit Court of Appeals. The consolidated case was held in abeyance in August 2024.

Chemical Industries

National Emission Standards for Hazardous Air Pollutants (NESHAP)

Under section 112 of the Clean Air Act, EPA must establish technology-based standards to control emissions of hazardous air pollutants from certain stationary sources. EPA must review the standards every 8 years and revise them as necessary taking into account any “developments in practices, processes, or control technologies.” This is referred to as the “technology review.”

New Source Performance Standards (NSPS)

Section 111(b) of the Clean Air Act requires EPA to set new source performance standards (NSPS) for new and modified stationary sources of emissions that cause or contribute significantly to air pollution that may reasonably be anticipated to endanger public health or welfare. The NSPS must be based on the “degree of emissions limitation achievable through the application of the best system of emission reduction [BSER] which . . . the Administrator determines has been adequately demonstrated.” 42 U.S.C. § 7411(a)(1).

Once NSPS are established for a particular type of stationary source, EPA must (with limited exception) then adopt emissions guidelines to regulate existing sources of the same type under section 111(d) of the Clean Air Act.  42 U.S.C. § 7411(d). The emissions guidelines are typically implemented by states, which must develop, and have approved by EPA, plans for controlling emissions from existing facilities in the source category. If a state fails to develop a plan, or the state plan is not approved by EPA, a federal plan will apply.

On May 16, 2024, EPA published a final rule revising the NESHAP and establishing updated NSPS for various pollutants emitted from the synthetic organic chemical manufacturing industry and polymers and resins industries. 89 Fed. Reg. 42,932 (May 16, 2024). (See Denka Performance Elas v. EPA in “Litigation” below.)

Litigation

Challenge to 2024 NESHAP and NSPS - Denka Performance Elas v. EPA

In July 2024, several states and industry parties filed a petition for review of EPA’s final rule in the D.C. Circuit Court of Appeals. As of January 19, 2025, the consolidated case had begun briefing but oral argument was not yet scheduled.

Biden Administration (2021-2024)

On May 16, 2024, EPA published a final rule revising the NESHAP and establishing updated NSPS for various pollutants emitted from the synthetic organic chemical manufacturing industry and polymers and resins industries. 89 Fed. Reg. 42,932 (May 16, 2024). (See Denka Performance Elas v. EPA in “Litigation” below.)

Obama Administration (2009-2016)

On June 2, 2008, EPA published a direct final rule extending a previous stay of certain requirements aimed at controlling equipment leaks of volatile organic compounds at petroleum refineries and synthetic organic chemical manufacturing facilities pending reconsideration of the requirements. 73 Fed. Reg. 31,372 (June 2, 2008). At the same time as it issued the direct final rule, EPA also issued a proposed rule to extend the stay, and requested public comment on the extension. 73 Fed. Reg. 31,416 (June 2, 2008). EPA noted that it had already “extend[ed] the stay as a direct final rule without a prior proposed rule. If we receive no adverse comments, we will not take further action on this proposal.”

On May 4, 2008, EPA wrote to groups that had requested reconsideration of certain provisions of a final rule issued on November 16, 2007 (during the George W. Bush Administration) establishing standards for equipment leaks of volatile organic compounds at petroleum refineries and synthetic organic chemical manufacturing facilities. EPA indicated that it was granting their request for reconsideration and would stay the the provisions under reconsideration for 90-days.

Litigation

Challenge to 2024 NESHAP and NSPS - Denka Performance Elas v. EPA

In July 2024, several states and industry parties filed a petition for review of EPA’s final rule in the D.C. Circuit Court of Appeals. As of January 19, 2025, the consolidated case had begun briefing but oral argument was not yet scheduled.