July 30, 2026

EPA Proposes to Change “Begin Actual Construction” Under New Source Review

On May 13, 2026, EPA proposed revisions to the CAA’s new source review (NSR) permitting program by amending the definition of “begin actual construction” and adding a definition of “pollutant-emitting activities”. [91 FR 26958] The current NSR regulations prohibit certain on-site construction activities on permanent emission units, such as the installation of building supports, foundations, laying underground piping, and the construction of permanent storage structures. The agency argues that prohibiting the construction of non-emitting sources before permit issuance unnecessarily delays projects and increases regulatory uncertainty while providing no additional meaningful public health and welfare protections.

EPA’s proposal reflects draft guidance from 2020 and is designed to ease a facility’s regulatory burden by distinguishing between construction activities associated with pollutant-emitting equipment and those of non-emitting equipment, structures, and activities. Specifically, the agency would amend 40 CFR 51.165, 51.166, 52.21, and Part 51, Appendix S by revising “begin actual construction” to read:

“Begin actual construction means, in general, initiation of physical on-site construction of pollutant-emitting activities on a stationary source. This does not include the following: (1) Engineering and desig planning; (2) geotechnical investigation (surface and subsurface explorations); (3) clearing vegetation, grading, surveying, soil compacting and stabilization (including associated pile driving), and excavating land (including blasting or other removal of hardrock); (4) ordering of equipment and materials; (5) storing of equipment or setting up temporary trailers to house construction management or staff and contractor personnel; (6) paving surfaces. This list is not intended to be exhaustive. With respect to a change in method of operations, this term refers to those on-site activities other than preparatory activities which mark the initiation of the change.”

A definition for “pollutant-emitting activities” would also be added to the regulations and read:

“Pollutant-emitting activities, as used in 40 CFR 52.21(b)(6)(i) and (b)(11), include any equipment or component in a process or operation that emits or has the potential to emit a regulated NSR pollutant. Pollutant-emitting activities do not include the following: (1) office buildings; (2) retail stores; (3) buildings or structures designed for storage if the product or material to be stored therein is not capable of producing airborne vapors or particles; (4) concrete pads and building foundations, walls, and roofs that are not closed in on the interior side and do not have design elements (e.g., piping, ductwork, wiring, anchor bolts) specifically and uniquely configured to serve or support any equipment or component in a process or operation that emits or has the potential to emit a regulated NSR pollutant; (5) equipment or components whose sole purpose is heating ventilation and air conditioning for human workspaces or spaces within a building used to store supplies related to the habitation of the building; (6) wiring, piping, and associated support structures that supply utility services (including electrical, water, wastewater, or telecommunications) to a property site or a building on a site; (7) sealed junctions or tieins within one process that may serve equipment or components in another process constructed at a later time. This list is not intended to be exhaustive. For purposes of this definition, classification as pollutant-emitting is based on emissions from a process or operation after construction, not emissions of pollutants during the construction process.”

The combined changes would impact both the nonattainment and prevention of significant deterioration programs under NSR. Though the comment period for the proposal has since expired, additional information is available via Docket ID No. EPA-HQ-OAR-2025-0618.

McCoy and Associates has provided in-depth information to assist environmental professionals with complex compliance issues since 1982. Our seminars and publications are widely trusted by environmental professionals for their consistent quality, clarity, and comprehensiveness.

Disclaimer

Considerable care has been exercised in preparing this document; however, McCoy and Associates, Inc. makes no representation, warranty, or guarantee in connection with the publication of this information. McCoy and Associates, Inc. expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any federal, state, or municipal law or regulation with which this information may conflict. McCoy and Associates, Inc. does not undertake any duty to ensure the continued accuracy of this information.

This document addresses issues of a general nature related to the federal environmental regulations. Persons evaluating specific circumstances dealing with the environmental regulations should review state and local laws and regulations, which may be more stringent than federal requirements. In addition, the assistance of a qualified professional should be enlisted to address any site-specific circumstances.