EPA issued a memorandum ending its longstanding “Reactivation Policy” for idle sources on a nationwide basis. Previously, under that policy, if a major industrial facility had been idle for two or more years, EPA presumed it was “permanently shut down,” requiring the source to obtain a new NSR permit as if it were a brand-new source before restarting operations. The September 2025 update eliminates that automatic presumption – EPA announced it will no longer apply any form of the Reactivation Policy in NSR permitting decisions or enforcement. Going forward, an idled facility can restart without an NSR permit unless the restart involves changes that qualify as a “major modification” (i.e. a physical change that causes a significant emissions increase) under the NSR rules. This change aligns EPA’s practice with a recent court interpretation of the Clean Air Act and is intended to reduce permitting hurdles for bringing idled plants (such as power generation units) back online more quickly.

See New Source Review Program “Reactivation Policy” | US EPA