Case Explained: ENVIRONMENTAL DEFENSE FUND v. ENVIRONMENTAL PROTECTION AGENCY AND LEE M. ZELDIN AIR PERMITTING FORUM, ET AL Consolidated with 21-1039, 21-1259, 25-1176

Court: United States Court of Appeals for the District of Columbia Circuit Filed: 2026-07-28 The dc-circuit denied petitions for review of EPA rules implementing “project emissions accounting” under the Clean Air Act’s New Source Review program. The court held that the rule is not contrary to law because it consistently applies the statutory definition of “modification” by allowing net calculations at both Step One and Step Two, and is not arbitrary or capricious because the EPA reasonably explained its decision to rely on existing recordkeeping requirements and non-binding guidance rather than adopting stricter binding restrictions on project aggregation. Consequently, the petitions are denied and the EPA’s rules remain in effect. Do It For The Case Law is a news reporting service. Nothing in this episode constitutes legal advice.