What to Know About the Supreme Court’s Clean Air Act Venue Test

The US Supreme Court released a pair of decisions on June 18 interpreting the Clean Air Act’s venue provision, which governs whether a lawsuit must be brought in the US Court of Appeals for the DC Circuit or in the regional court of appeals. Where to file in CAA cases has long bedeviled litigants, consuming time and money as parties bicker over the right place for a case to be heard.

In EPA v. Calumet Shreveport and Oklahoma v. EPA, the Supreme Court laid out new rules of the road. Here is what litigants should know about how to approach CAA venue disputes going forward.

The New Test

In Calumet Shreveport, the court articulated a two-step venue test. At step one, courts ask whether the EPA’s action applies throughout the entire country or only locally or regionally. If it applies throughout the country, the challenge belongs in the DC Circuit; if not, the challenge presumptively belongs in a regional circuit.

An action isn’t “nationally applicable” merely because it bundles multiple decisions together that cross circuit lines, affects more than one circuit, has nationally applicable downstream effects, or articulates standards that could apply to future decisions. In Calumet Shreveport, for instance, the EPA bundled 105 actions denying exemptions to individual refineries together into one omnibus rule in a way that could affect future decisions. That didn’t matter; the relevant action was still each individual denial.

If the action is locally or regionally applicable, step two asks whether that action is “based on a determination of nationwide scope or effect,” and whether the EPA made and published a statement making that finding. If so, the challenge belongs in the DC Circuit.

A determination has “nationwide scope or effect” if the EPA’s justification applies nationally as a legal or practical matter. For example, in Calumet Shreveport, the EPA denied the exemptions based on an economic theory and statutory interpretation that applied to all refineries nationwide. And an action is “based on” the nationwide determination if that is the most important part—the gravamen—of the EPA’s reasoning. A determination falls short “if EPA also relied in significant part on other, intensely factual considerations.”

Expect ‘Gravamen’ Debates

The EPA often takes local or regional actions that are at least partially predicated on nationally applicable reasoning. Calumet Shreveport and Oklahoma prove why determining what is the “gravamen” of the EPA’s reasoning could prove challenging in practice.

Compare the two cases the Supreme Court decided.

In Calumet Shreveport, the EPA announced a presumption that all petitions should be rejected and only considered refinery-specific facts to decide whether to deviate from the presumption. Because the EPA relied on its determination of nationwide scope or effect to reach a presumptive resolution, those determinations qualified as the decision’s gravamen—and venue belonged in the DC Circuit.

In Oklahoma, the EPA again made nationwide methodological determinations about how it would evaluate each state’s proposal for complying with the EPA’s air quality standards. But the state-specific application of those guiding principles was far more important to the result—meaning venue belonged in the regional circuit.

As Justice Elena Kagan summed up at oral argument, in “one, everything is being decided by the nationwide determination; and the other, pretty much nothing is being decided by the nationwide determination.”

Those conclusions weren’t necessarily obvious, as the dissenters in Calumet Shreveport observed. Both sets of actions incorporated some nationwide determinations and some individual facts and how to separate the gravamen from the not-gravamen is a matter of degree and judgment.

But gravamen tests aren’t new. Courts ask whether the gravamen of the action occurred abroad in analyzing Foreign Sovereign Immunities Act suits and use the gravamen test to distinguish between contract and tort actions. Perhaps that experience will make this test easier to apply in practice. Or perhaps not. Debates will remain.

Manipulating Venue

The EPA still can manipulate venue through the nationwide-scope-or-effect exception. To trigger the exception, the EPA must find and publish a determination that its action is based on a determination of nationwide scope or effect.

A court still must agree, but if the EPA wants to litigate in the DC Circuit, it will include the finding. And if the EPA wants to litigate elsewhere, omitting that determination will leave litigants with no choice.

Protective Petitions

To hedge their bets, petitioners often file protective petitions in both the regional circuit and the DC Circuit. Filing in just one circuit risks timeliness issues if the court dismisses for improper venue, rather than transferring the case to the other court.

However, filing a protective petition means a fight over venue is practically inevitable, and it can be costly and frustrating to litigate venue before getting to the merits. As Justice Neil Gorsuch’s dissent observed, “[l]itigation over whether the case is in the right court is essentially a waste of time and resources.”

Calumet Shreveport and Oklahoma clarify the rules of the road for CAA petitioners. But given the difficulty in identifying the gravamen of an EPA action, litigants shouldn’t jettison protective petitions just yet.

The cases are Environmental Protection Agency v. Calumet Shreveport Refining, L.L.C., U.S., No. 23-1229, 6/18/25; Oklahoma v. Environmental Protection Agency, U.S., No. 23-1067, 6/18/25.

This article does not necessarily reflect the opinion of Bloomberg Industry Group, Inc., the publisher of Bloomberg Law, Bloomberg Tax, and Bloomberg Government, or its owners.

Author Information

Sean Marotta is partner at Hogan Lovells and has argued at the Supreme Court and in state and federal courts across the country.

Danielle Desaulniers Stempel is a senior associate in Hogan Lovells’ Supreme Court and Appellate practice group who regularly litigates administrative-procedure cases.

Joe Liberman contributed to this article.

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