On June 21, 2021, the U.S. Court of Appeals for the Third Circuit issued its opinion in Clean Air Council v. U.S. Steel, a case that reversed the Environmental Protection Agency’s (EPA) 30-year-old position concerning release reporting of air releases under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). CERCLA imposes heavy penalties on companies, including individual “persons in charge,” that fail to report releases of certain hazardous chemicals “immediately.” However, Congress excluded some types of releases from CERCLA’s reporting requirements under the “federally permitted release” exclusion. EPA’s longstanding interpretation of that exclusion had been that a federally permitted release is one that occurs in compliance with a federally enforceable permit, that is, that a release violating a permit term is not exempted. In Clean Air Council, the Third Circuit (which covers Delaware, New Jersey, Pennsylvania, and the U.S. Virgin Islands) unanimously held that the exemption extends to air releases “subject to” such a permit but not necessarily “in compliance with” that permit, affirming the Western District of Pennsylvania’s decision to dismiss a lawsuit on those grounds. Clean Air Council is an important decision for companies facing similar failure-to-report suits and for those deciding what releases must be reported to whom.