Non-GHG Emission Standards with GHG Co-Benefits

Cross-State Air Pollution Rule

Under section 110(a)(1) of the Clean Air Act, within 3 years after EPA promulgates or revises a national primary ambient air quality standard (or such shorter period as the EPA Administrator may prescribe), states must submit to EPA a state implementation plan (SIP) providing for the “implementation, maintenance, and enforcement” of the standard (42 U.S.C. § 7410(a)(1)). Each SIP must include provisions sufficient to “prohibit[] . . . any source or other type of emissions activity within the state from emitting any air pollutant in amounts which will . . . contribute significantly to nonattainment” of the NAAQS in another state or interfere with maintenance of the NAAQS in another state (42 U.S.C. § 7410(a)(2)(D)(i)(I)). This is known as the “good neighbor provision.” If states fail to include the necessary good neighbor provisions, or their SIPs are otherwise found to be inadequate, EPA must issue an enforce a federal implementation plan (FIP).

On April 30, 2021, EPA published a final rule announcing its determination that, for 9 of the 21 states for which it had previously issued FIPs to address their good neighbor obligations, their projected ozone emissions do not significantly contribute to NAAQS nonattainment or maintenance problems in other states. 86 Fed. Reg. 23,054 (Apr. 30, 2021). For the other 12 states, EPA determined that their ozone emissions do significantly contribute to downwind states’ nonattainment and/or maintenance problems, and issued new or amended FIPs for those states. The rule was issued in response to the D.C. Circuit Court of Appeals’ remand of a previous EPA rule establishing FIPs for 22 states to address their interstate pollution-transport obligations in Wisconsin v. EPA. The rule was proposed under the Trump Administration. (See Wisconsin v. EPA in “Litigation” below.)

Biden Administration (2021-2024)

On April 30, 2021, EPA published a final rule announcing its determination that, for 9 of the 21 states for which it had previously issued FIPs to address their good neighbor obligations, their projected ozone emissions do not significantly contribute to NAAQS nonattainment or maintenance problems in other states. 86 Fed. Reg. 23,054 (Apr. 30, 2021). For the other 12 states, EPA determined that their ozone emissions do significantly contribute to downwind states’ nonattainment and/or maintenance problems, and issued new or amended FIPs for those states. The rule was issued in response to the D.C. Circuit Court of Appeals’ remand of a previous EPA rule establishing FIPs for 22 states to address their interstate pollution-transport obligations in Wisconsin v. EPA. The rule was proposed under the Trump Administration. (See Wisconsin v. EPA in “Litigation” below.)

First Trump Administration (2017–2020)

On October 30, 2020, EPA issued a proposed rule in response to the D.C. Circuit’s remand in Wisconsin v. EPA. 85 Fed. Reg. 68,964 (Oct. 30, 2020). The rule was finalized under the Biden Administration. (See Wisconsin v. EPA in “Litigation” below.)

On December 21, 2018, EPA published final rule (known as the “Close-Out Rule”) announcing its determination that the 2016 update to the Cross-State Air Pollution Rule fully satisfies “good neighbor” obligations for the 2008 ground-level ozone NAAQS and, as a result, no further emissions reductions are required in upwind states. 83 Fed. Reg. 65,878 (Dec. 21, 2018). (See New York v. EPA in “Litigation” below.)

Obama Administration (2009–2016)

On October 26, 2016, EPA issued a final rule updating its Cross-State Air Pollution Rule to address interstate transport of ozone pollution. 81 Fed. Reg. 74,504 (Oct. 26, 2016). EPA determined that emissions of oxides of nitrogen in 22 eastern states contribute to ozone pollution problems in downwind areas and established FIPs to control emissions from power plants in the states. (See Wisconsin v. EPA in “Litigation” below.)

On December 27, 2011, EPA published a final rule supplementing the August 2011 Cross-State Air Pollution Rule. 76 Fed. Reg. 80,760 (Dec. 27, 2011). EPA determined that additional states, beyond the 27 identified in its August 2011 rule, release emissions that significantly contribute to nonattainment or maintenance problems in downwind states and established FIPs to control those emissions. 

On August 8, 2011, EPA published the final Cross-State Air Pollution Rule. 76 Fed. Reg. 48,208 (Aug. 8, 2011). The rule replaced EPA’s 2005 Clean Air Interstate Rule (CAIR). The rule establishes a regulatory framework for reducing interstate sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions from power plants in “upwind” states that contribute to non-attainment with, or impaired maintenance of, NAAQS for ozone and fine particulate matter (PM2.5) in “downwind” states. EPA determined that emissions in 27 states significantly affected the ability of downwind states to attain or maintain the NAAQS and thus issued FIPs to regulate emissions sources (specifically power plants) in the states. (See EPA v. EME Homer City Generation in “Litigation” below.)

Litigation

Challenge to 2018 Close-Out Rule - New York v. EPA

On January 30, 2019, a coalition of states filed a petition for review of the 2018 Close-Out Rule in the D.C. Circuit Court of Appeals. New York v. EPA, No. 19-1019 (D.C. Cir.). A coalition of environmental groups also filed a petition for review. On October 1, 2019, the DC Circuit rejected EPA’s Close-Out Rule, finding that EPA has not implemented stringent enough rules to deal with cross-state air pollution affecting downwind states.

Challenge to 2016 Rule - Wisconsin v. EPA

On November 23, 2016, a coalition of states filed a petition for review of the 2016 Cross-State Air Pollution Rule in the D.C. Circuit Court of Appeals. On September 13, 2019, the court issued an opinion granting in part and denying in part the petitions for review in the consolidated case. The court largely upheld the rule, except for a provision that allows upwind states to continue to pollute downwind states past the statutory deadline for downwind states to comply with the NAAQS. This portion of the rule was sent back to EPA for review.

Challenge to 2011 Rule - EPA v. EME Homer City Generation

The Supreme Court upheld the 2011 Cross-State Air Pollution Rule in EPA v. EME Homer City Generation, L.P., 134 S. Ct. 1584 (2014), reversing the D.C. Circuit Court of Appeals’ 2012 decision to overturn the rule.