Utility Air Regulatory Group v. EPA, 573 U.S. 302

Justia Summary

The Clean Air Act requires permits for stationary sources, such as factories and powerplants. The Act’s “Prevention of Significant Deterioration” (PSD) provisions make it unlawful to construct or modify a “major emitting facility” in “any area to which [PSD program] applies” without a permit, 42 U.S.C. 7475(a)(1), 7479(2)(C). A “major emitting facility” is a stationary source with the potential to emit 250 tons per year of “any air pollutant” (or 100 tons per year for certain sources). Facilities seeking a PSD permit must comply with emissions limitations that reflect the “best available control technology” (BACT) for “each pollutant subject to regulation under” the Act and it is unlawful to operate any “major source,” wherever located, without a permit. A “major source” is a stationary source with the potential to emit 100 tons per year of “any air pollutant,” under Title V of the Act. In response to the Supreme Court decision, Massachusetts v. EPA, the EPA promulgated greenhouse-gas (GHG) emission standards for new vehicles, and made stationary sources subject to the PSD program and Title V, based on potential GHG emissions. Recognizing that requiring permits for all sources with GHG emissions above statutory thresholds would render the programs unmanageable, EPA purported to “tailor” the programs to accommodate GHGs by providing that sources would not become newly subject to PSD or Title V permitting on the basis of their potential to emit GHGs in amounts less than 100,000 tons per year. The D.C. Circuit dismissed some challenges to the tailoring rule for lack of jurisdiction and denied the rest. The Supreme Court affirmed in part and reversed in part, finding that the Act does not permit an interpretation requiring a source to obtain a PSD or Title V permit on the sole basis of potential GHG emissions. The Massachusetts decision held that the Act-wide definition of “air pollutant” includes GHGs, but with respect to PSD and Title V permitting provisions, EPA has employed a narrower, context-appropriate meaning. Massachusetts did not invalidate the long-standing constructions. “The Act-wide definition is not a command to regulate, but a description of the universe of substances EPA may consider regulating.” The presumption of consistent usage yields to context and distinct statutory objects call for different implementation strategies. EPA has repeatedly acknowledged that applying PSD and Title V permitting requirements to GHGs would be inconsistent with the Act’s structure and design, which concern “a relative handful of large sources capable of shouldering heavy substantive and procedural burdens.” EPA lacked authority to “tailor” the Act’s unambiguous numerical thresholds to accommodate its GHG-inclusive interpretation. EPA reasonably interpreted the Act to require sources that would need permits based on emission of conventional pollutants to comply with BACT for GHGs. BACT, which has traditionally been about end-of-stack controls, may be fundamentally unsuited to GHG regulation, but applying BACT to GHGs is not "disastrously unworkable," and need not result in a dramatic expansion of agency authority.