Case Explained: GreenLatinos, et al. v. Suncor Energy (U.S.A.)

Court: United States Court of Appeals for the Tenth Circuit Filed: 2026-08-03 Docket: 1:24-CV-02164-DDD-SBP) The tenth-circuit reversed the district court’s dismissal of environmental organizations’ Clean Air Act citizen suit against Suncor Energy, holding that the district court incorrectly applied the statute’s diligent prosecution bar. The court determined that the diligent prosecution bar under 42 U.S.C. § 7604(b)(1)(B) is a non-jurisdictional affirmative defense, not a limit on subject-matter jurisdiction. Applying a text-based analysis, the court established that the bar precludes a citizen suit only if three specific elements are met: (1) there is a present civil action in a judicial court (such as an ongoing consent decree) rather than merely administrative enforcement actions; (2) the standards or limitations being enforced in that judicial action are identical to those alleged in the citizen suit, excluding claims based on “substantially similar” but distinct regulatory requirements; and (3) the government is diligently prosecuting that specific action. The district court erred by applying the bar to claims based on administrative actions and by barring suits alleging standards not identical to those in the underlying consent decrees. The case is remanded for further proceedings consistent with this opinion, requiring the district court to apply the correct legal standard to determine which claims, if any, are precluded. Do It For The Case Law is a news reporting service. Nothing in this episode constitutes legal advice.