In its recent decision in Coalition for Responsible Regulation, Inc. v. EPA, No. 09-1322 (D.C. Cir. Apr. 10, 2015), the D. C. Circuit Court of Appeals narrowed the United States Environmental Protection Agency’s greenhouse gas (GHG) permit rule (sometimes called the Tailoring Rule, 40 C.F.R. §§ 51.166(b)(48)(v) and 52.21 (b)(49)(v)) in accordance with the Supreme Court’s decision in Utility Air Regulatory Group (UARG) v. EPA, 134 S. Ct. 2427 (2014).

 In UARG v. EPA, the Court held that EPA could only require best available control technology (BACT) reviews for GHGs at facilities that would be subject to prevention of significant deterioration (PSD) for conventional pollutants, regardless of a source’s GHG emissions (so-called “anyway sources”). Relying on this holding, the court vacated the Tailoring Rule to the extent it requires sources to obtain PSD or Title V permits solely due to a potential to emit GHGs. The court also formally ended the cases challenging the Agency’s landmark motor vehicle GHG rules, endangerment finding, and remaining permit requirements – again, consistent with the Supreme Court’s ruling.

The court also ordered EPA to “consider any further revisions” to the rules that may be necessary. Presumably, this directs EPA to establish a de minimis threshold for GHGs that would apply in PSD or Title V permit actions. In the Tailoring Rule, USEPA used 75,000 tons of CO₂e as a trigger, but now it must, consistent with the Supreme Court’s direction, consider setting an appropriate de minimis threshold.

Before the April 10 order, several facilities obtained PSD and/or Title V permits as a result of their GHG emissions. EPA plans to finalize a new rule by the end of 2015 for rescinding these permits.