On June 8, 2018, in National Environmental Development Association’s Clean Air Project v. Environmental Protection Agency, ___ F.3d. ___, No. 16-1344, No. 2018 WL 2749179 (D.C. Cir. June 8, 2018), the D.C. Circuit upheld a revised EPA regulation that permits the EPA to follow regional circuit interpretations of the Clean Air Act only within the territory covered by that regional circuit. Under the revised rules, the EPA is only required to give nationwide effect to cases decided by the D.C. Circuit or the United States Supreme Court.

The need for the revised regulation came from the fallout from a Sixth Circuit decision, Summit Petroleum Corp. v. Environmental Protection Agency, 690 F.3d 733 (6th Cir, 2012), where the court found that the EPA was improperly determining whether multiple operations constitute a single major source. The Sixth Circuit’s decision conflicted with the EPA’s national policy for making such single-source determinations. In response, the EPA headquarters issued the “Summit Directive” instructing its Regional Air Directors to continue to apply the EPA’s national policy outside of the Sixth Circuit.

An industry group challenged the Summit Directive, and in National Environmental Development Association’s Clean Air Project, 752 F.3d 999 (D.C. Cir. 2014), the D.C. Circuit held that Summit Directive violated the EPA’s regional consistency regulations, 40 C.F.R. § 56.3. The court did not address whether the Summit Directive violated the statutory requirements of the Clean Air Act.

In response, the EPA used the rulemaking process to amend 40 C.F.R. § 56.3 to make it clear that the EPA is only bound nationwide by decisions of the D.C. Circuit and the Supreme Court. Industry groups again challenged the new rule, but the D.C. Circuit upheld it finding that it did not conflict with the plain meaning of the Clean Air Act.