In a pair of consolidated cases— Oklahoma v. EPA and PacifiCorp v. EPA — the Supreme Court is considering the scope of the Clean Air Act's (CAA) judicial review provision, and whether the Environmental Protection Agency's (EPA) coordinated disapproval of state implementation plans (SIPs) constitutes a "nationally applicable" action or one of "nationwide scope or effect" that must be challenged in the D.C. Circuit.
Under the Clean Air Act, 42 U.S.C. § 7607(b)(1), EPA actions that are "locally or regionally applicable" must be challenged in the appropriate regional circuit. In contrast, "nationally applicable" actions, or regional actions that the EPA Administrator determines are based on a "nationwide scope or effect," must be reviewed exclusively by the D.C. Circuit.
In a February 2023 final rule, the EPA disapproved 21 SIPs, finding they failed to adequately address interstate pollution obligations—specifically, their contributions to air quality problems in downwind states under the CAA's "good neighbor" provision. All 21 disapprovals were published in a single Federal Register notice and applied a uniform analytical framework, including the EPA's use of a 1% threshold for identifying significant cross-state contributions.
Petitioners from 12 states challenged the disapprovals (as applied to those states) in their respective regional circuits. While courts in the Fourth, Fifth, Sixth, and Eighth Circuits allowed those petitions to proceed locally, the Tenth Circuit granted the EPA's motion to transfer the Oklahoma and Utah petitions to the D.C. Circuit. The Tenth Circuit reasoned that the EPA's disapprovals were "nationally applicable" due to their coordinated issuance and uniform analytical approach.
The Supreme Court agreed to review the Tenth Circuit's decision.
During oral argument on March 25, 2025, the Justices focused on whether the Tenth Circuit applied the correct standard under § 7607(b)(1). Justice Jackson, a former D.C. Circuit judge, emphasized that SIP approvals are expressly defined in the statute as regionally applicable actions. Therefore, she suggested that if the disapprovals were subject to D.C. Circuit review, it would be under the "nationwide scope or effect" exception—not the "nationally applicable" prong invoked by the Tenth Circuit. She also raised whether the case should be remanded so that the lower court could consider the exception correctly.
Counsel for the petitioners urged the Court to provide clarity on the meaning and application of the "nationwide scope or effect" exception rather than remanding. Justice Sotomayor expressed skepticism about the EPA's claim of nationwide scope, noting that states are not bound to adopt EPA's modeling or thresholds. Even if multiple SIPs failed for similar reasons, she suggested that it did not necessarily convert a regional issue into a national one. Conversely, Justice Gorsuch argued that interstate pollution inherently raises national concerns, as emissions transcend state boundaries. Justices Kagan, Gorsuch, and Jackson then explored a potential middle ground: D.C. Circuit review might be appropriate where the EPA introduces new nationwide standards affecting many states similarly, but regional circuits may be better where the standards are settled and the disputes turn on state-specific facts.
Chief Justice Roberts, also a former D.C. Circuit judge, acknowledged the benefit of uniform national standards but expressed concern that regional nuances could be overlooked in D.C. Circuit proceedings. Justice Kavanaugh, who also was a D.C. Circuit judge, dismissed suggestions that local issues are poorly handled by the D.C. Circuit. Justice Jackson challenged the EPA's assertion that collective publication of the disapprovals in a single notice should drive venue. "Is § 7607(b)(1) really about the EPA's publishing decisions?" she asked. Counsel for the EPA acknowledged that if the disapprovals had been issued separately and tailored to state-specific facts, they likely would qualify as regional actions. Justices Gorsuch and Kavanaugh questioned whether the EPA's own conclusion that its action had "nationwide scope or effect" was entitled to judicial deference. Petitioners argued it is not.
In a moment of levity near the end of the hearing, EPA counsel addressed petitioners' implication that the agency enjoys a "home court advantage" in the D.C. Circuit. If that were true, he quipped, the EPA should also benefit from a "home court" advantage in the Supreme Court—a suggestion met with laughter. He concluded dryly, "I've never had that perception," possibly alluding to the Court's unfavorable decision for the EPA issued a few weeks earlier,San Francisco v. EPA(March 4, 2025).
The Court's forthcoming ruling is expected to clarify how broadly courts should interpret EPA actions involving multiple states, and whether an agency's coordinated publication and analysis transforms regional disputes into national ones. The decision could shape venue strategy in future CAA litigation and affect how federal agencies structure their actions that affect multiple states or regions.
Stay tuned for Dykema's decision alert after the Court issues its opinion, which is expected later this term.
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