From Local Petitions to National Venue:
The Supreme Court’s Two-Step Test for the Clean Air Act’s “Nationwide Scope or Effect” Exception

I. Introduction

EPA v. Calumet Shreveport Refining, L.L.C., 605 U.S. ___ (2025) squarely addresses an esoteric yet practically critical component of environmental litigation: where a challenger must file suit under the Clean Air Act (CAA). The petitioners were six small refineries located within the Fifth Circuit that had unsuccessfully sought economic-hardship exemptions from the CAA’s Renewable Fuel Program (RFP). Their petitions were denied in two omnibus Federal Register notices issued by the Environmental Protection Agency (EPA) in 2022. EPA insisted that any challenge belonged in the D.C. Circuit; the refineries sued closer to home. Most regional circuits agreed with EPA and transferred their cases, but the Fifth Circuit retained jurisdiction, vacated the denials, and set up a conflict that demanded Supreme Court resolution.

The Supreme Court—by a 7-2 vote (Justice Thomas for the Court, Justice Gorsuch dissenting, Chief Justice Roberts joining the dissent)—clarifies both (1) how to identify the “action” whose applicability matters for venue and (2) when a locally applicable action is nonetheless reviewable exclusively in the D.C. Circuit because it is “based on a determination of nationwide scope or effect.” The Court crafts a two-step venue framework that will now govern virtually every Clean Air Act case and exert persuasive influence across other environmental statutes with analogous language.

II. Summary of the Judgment

1. Step 1 — Action Characterization. Each individual denial of a refinery’s exemption petition is the operative “final action,” not the omnibus notice that bundled them. Because each denial applies only to a single facility in a single place, it is “locally or regionally applicable,” not “nationally applicable.”
2. Step 2 — The Exception. A locally applicable action must still be heard in the D.C. Circuit if it is “based on a determination of nationwide scope or effect” and EPA has “so found and published.” Here, EPA’s uniform interpretation of “disproportionate economic hardship” and its nationwide “RIN passthrough” economic theory were the primary drivers of every denial; they therefore count as determinations of nationwide scope/effect. EPA also expressly published that finding. Venue thus lies exclusively in the D.C. Circuit, and the Fifth Circuit should have transferred the petitions instead of deciding their merits.
3. Disposition. The Fifth Circuit’s judgment is vacated and the case is remanded with instructions to transfer the petitions to the D.C. Circuit.

III. Analytical Commentary

A. Precedents Cited and Their Influence

• Harrison v. PPG Industries, 446 U.S. 578 (1980) — Demonstrated the pre-1977 “patchwork” venue regime and underlined Congress’s intent to channel CAA litigation into appellate courts.
• Sierra Club v. EPA, 926 F.3d 844 (D.C. Cir. 2019) — Provided the “on its face” test for distinguishing nationally from locally applicable actions; the Court adopts that linguistic approach.
• Texas v. EPA, 829 F.3d 405 (5th Cir. 2016) — Coined the “core justification” concept for identifying whether a nationwide determination undergirds the action; the Court expressly borrows that formulation.
• Kentucky v. EPA, 123 F.4th 447 (6th Cir. 2024) — Supplied helpful definitional scaffolding for “action” and “nationwide scope.”
• HollyFrontier Cheyenne Refining v. Renewable Fuels Assn., 594 U.S. 382 (2021) — Triggered EPA’s reconsideration of pending exemption petitions and contextualized the litigation’s factual origins.

B. Legal Reasoning

1. Determining the Proper “Action”

Section 7607(b)(1) lists specific examples of “actions” and then uses parallel “any other” clauses. Reading those clauses ejusdem generis, the Court holds that Congress meant each discrete statutory power to constitute its own action. Thus, “EPA’s denial of Refinery X’s exemption petition” is an action; “EPA’s 280-page notice denying 105 petitions” is merely the agency’s chosen packaging.

2. Locally vs. Nationally Applicable

Applying ordinary-meaning dictionaries and comparing to the enumerated list, the Court treats an action as “nationally applicable” only if—on its face—it governs every place in the United States. Single-refinery denials obviously fail that test.

3. The “Nationwide Scope or Effect” Exception Refined

1. Dual Statutory Requirements. (a) the action must be “based on” a determination of nationwide scope/effect; and (b) EPA must publish that finding.
2. “Based on”. The Court rejects ordinary but-for causation as too broad, instead adopting a “core justification / primary driver” standard. If EPA relies on a nationwide premise to reach a presumptive outcome, local fact-checking cannot re-localize the action.
3. De Novo Review. Because the statute uses both an objective and subjective requirement (“based on” + “EPA so finds”), courts must independently examine the record; arbitrary-and-capricious deference is inapposite.

4. Application to the 2022 Denials

• Nationwide Determinations Identified: (i) Only hardship caused by RFP compliance qualifies; (ii) RIN costs are fully passed through to consumers, so hardship is presumptively absent.
• Role in Decision-Making: These determinations predicated a blanket presumption of denial; refinery-specific data were used only to confirm they did not rebut the presumption — thus “peripheral.”

5. Rejection of Counter-Arguments

EPA’s attempt to self-define the pertinent action by aggregating petitions was rejected as “venue veto” gamesmanship. The dissent’s narrower, term-of-art reading of “determination” was dismissed as rendering the exception “a null set.” Meanwhile, the Fifth Circuit’s reliance on the local “legal effect” of the denials was brushed aside because the statutory text requires only that a nationwide determination be the action’s primary basis, not its exclusive basis.

C. Potential Impact

• Venue Clarity Across the CAA. Litigants now have a predictable two-step roadmap that should reduce forum-shopping and early-stage dismissal motions.
• Agency Drafting Strategies Curtailed. EPA cannot manipulate venue by bundling or splitting decisions; what matters is the statutory unit of action.
• Expansion Beyond the CAA. Other statutes with similar “based on” venue toggles (e.g., Clean Water Act §509(b)) will likely import the Court’s “primary driver” test.
• Substantive Incentives. Because nationwide reasoning triggers D.C. Circuit venue, EPA may think twice before relying on broad legal or economic theories when acting locally — potentially nudging the agency toward more tailored, data-rich decision-making.
• Litigation Efficiency. Expect consolidation of many industry challenges in a single circuit, reducing circuit splits but concentrating docket pressure on the D.C. Circuit.

IV. Complex Concepts Simplified

• Renewable Identification Numbers (RINs): Think of RINs as “digital coupons” proving a refinery blended (or bought the right to count) renewable fuel. Buying RINs is akin to paying someone else to do your homework; EPA assumed that any cost to buy them is simply passed through to consumers at the gas pump.
• Disproportionate Economic Hardship: A statutory safety valve allowing small refiners to avoid the blending mandate if they can show it hurts them more than competitors.
• Venue vs. Jurisdiction: Venue is the geographic court in which a case is heard; jurisdiction is the court’s power to hear it at all. Here everyone agreed federal appellate jurisdiction existed; the fight was over which circuit.
• Omnibus Notice: A single Federal Register document that decides multiple similar cases in one stroke. The Court holds such bundling does not change each underlying “action.”
• Nationwide Scope vs. Nationwide Effect: Scope = applies everywhere as a matter of law; Effect = functionally influences everywhere in practice. Either suffices.

V. Conclusion

EPA v. Calumet Shreveport Refining answers a longstanding procedural puzzle under the Clean Air Act and does so with a framework likely to govern environmental litigation for years. By disentangling the statutory concept of an “action” from the agency’s administrative packaging and establishing a “primary driver” test for the nationwide scope/effect exception, the Court limits agency influence over forum selection and promotes consistent application of venue rules. At the same time, the decision cautions EPA that broad, nationwide reasoning can boomerang, pushing cases to the D.C. Circuit even when the immediate target is a single facility. Whether this incentivizes more granular decision-making or simply accelerates national consolidation of environmental disputes remains to be seen, but the pathway is now sharply defined.