Proposed rule · 2026-09524

Begin Actual Construction in the New Source Review (NSR) Preconstruction Permitting Program

The U.S. Environmental Protection Agency (EPA) is proposing revisions to the New Source Review (NSR) air permitting regulations. These regulatory revisions would distinguish between construction of a stationary source and construction of non-emitting components or structures, while clarifying and codifying that the latter can occur before an owner or operator obtains an NSR air permit for a new major stationary source or major modification of an existing major stationary source. The revisions will update the definition of "begin actual construction" and add a definition of "pollutant-emitting activities" in the Federal NSR regulations for both Nonattainment New Source Review (NNSR) and Prevention of Significant Deterioration (PSD); revise the definition of "begin construction" and "commence construction" in the Federal minor NSR regulations applicable in Indian country; and address the applicability procedures for "begin actual construction" in the NNSR regulations.