U.S. EPA Restores Affirmative Defense Protections Under Federal Air Permits

The U.S. Environmental Protection Agency on May 28 restored affirmative defense protections under federal air permitting regulations following a federal court ruling that overturned a 2023 Biden administration rule. The move relieves manufacturers, power producers, and other industrial facilities from potential liability for excess emissions caused by unavoidable events such as equipment malfunctions, emergencies, or natural disasters. It also removes requirements for state, local, and tribal permitting authorities to revise operating permit programs and existing permits to comply with the 2023 rule.

The Biden administration eliminated affirmative defense provisions from federal Title V air permitting regulations in 2023, exposing facilities to enforcement actions even when operators took reasonable steps to prevent and mitigate excess emissions during unforeseen events. Industry groups argued that the change created regulatory uncertainty and increased compliance risks for facilities operating under federal air permits.

Earlier this year, the U.S. Court of Appeals for the District of Columbia Circuit reversed the 2023 rule, prompting EPA to restore the previous regulatory framework. The agency indicated that the action is necessary to comply with the court’s mandate and return federal regulations to their pre-2023 structure.

Under the restored framework, facilities may demonstrate that excess emissions resulted from circumstances beyond their control and that operators acted responsibly to minimize environmental impacts. Federal regulators emphasized that the change does not alter emissions limits or weaken enforcement authority against facilities that violate environmental requirements through avoidable actions or negligence.

EPA also encouraged facilities to continue investing in maintenance, prevention, and rapid-response measures designed to reduce emissions during unexpected operational disruptions. The action takes effect immediately and is expected to provide greater regulatory certainty for energy producers, manufacturers, and other industrial operators while preserving existing environmental protections.