Utility And Regulatory Group v. EPA

134 S.Ct. 2427 (2014)


The Clean Air Act regulates pollution from both stationary sources and moving sources. Stationary sources are subject to the Act’s provisions relating to “Prevention of Significant Deterioration” (PSD). It is unlawful to construct or modify a “major emitting facility” in “any area to which [the PSD program] applies” without first obtaining a permit. The statute sets numerical thresholds (100 or 250 tons per year) for emissions that will make a facility “major,” it does not specify by how much a physical or operational change must increase emissions to constitute a permit-requiring “modification.” Nor does it say how much of a given regulated pollutant a “major emitting facility” must emit before it is subject to BACT for that pollutant. D has established pollutant-specific numerical thresholds below which a facility’s emissions of a pollutant, and increases therein, are considered de minimis for those purposes. Title V of the Act makes it unlawful to operate any “major source,” wherever located, without a comprehensive operating permit. Because greenhouse-gas emissions tend to be “orders of magnitude greater” than emissions of conventional pollutants, D projected that numerous small sources not previously regulated under the Act would be swept into the PSD program and Title V, including “smaller industrial sources,” “large office and residential buildings, hotels, large retail establishments, and similar facilities.” D announced that beginning on the effective date of its greenhouse-gas standards for motor vehicles, stationary sources would be subject to the PSD program and Title V on the basis of their potential to emit greenhouse gases. D adopted a “phase-in approach” that it said would “apply PSD and title V at threshold levels that are as close to the statutory levels as possible. EPA codified step rules for sources emitting 50,000 tons per year of CO2. Ps filed petitions for review, and the Court of Appeals dismissed some of the petitions for lack of jurisdiction and denied the remainder. The court granted certiorari for one question: “‘Whether EPA permissibly determined that its regulation of greenhouse gas emissions from new motor vehicles triggered permitting requirements under the Clean Air Act for stationary sources that emit greenhouse gases.’”