The U.S. Environmental Protection Agency on May 11proposed a rule that would narrow when a new source review (NSR) preconstruction permitting obligations attach for new major stationary sources and major modifications at an existing major source.
The proposal would allow certain on-site work on non-emitting components to proceed before permit issuance and largely follows positions EPA previewed in 2020 draft guidance and a 2025 letter to the Maricopa County Air Quality Department.
Comments on the proposal are due June 29. APPA said it is evaluating whether to develop comments on the proposal.
EPA frames the proposal as a clarification intended to improve regulatory certainty and better align the NSR rules with the Clean Air Act (CAA).
APPA noted that EPA’s core statutory analysis turns on two questions: “what” requires a permit, and when construction of that “what” begins.
On the first question, EPA concludes that NSR applies to the construction of equipment or components that emit, or have the potential to emit, regulated pollutants -- not to items that lack that characteristic.
EPA acknowledges that the statute is less explicit on “when” construction begins. It nonetheless concludes that the best reading of the CAA is that a permit is required when physical on-site construction begins on pollutant-emitting equipment or components, rather than when work begins on non-emitting structures or support features.
EPA also departs from earlier policy concerns that pre-permit investments could pressure permitting authorities to relax NSR requirements, stating that applicants proceed at their own risk and cannot rely on pre-permit work to influence substantive permitting decisions.
APPA listed the following as key proposed changes:
- Revised permitting trigger: EPA would redefine “begin actual construction” as the initiation of physical on-site construction of pollutant-emitting activities on a stationary source. The proposal identifies several activities that could occur before permit issuance, including clearing, grading, surveying, and soil compaction and stabilization.
- Defined scope of “pollutant-emitting activities”: EPA would define the term to cover equipment or components in a process or operation that emit, or have the potential to emit, a regulated NSR pollutant. The proposal would also exclude certain non emitting structures and support systems, including specified pads, foundations, utility wiring and piping, and some sealed junctions or tie-ins.
- Reduced emphasis on “equity in the ground”: EPA rejects the view that pre-permit site work should be broadly restricted to avoid economic pressure on permitting authorities. Instead, EPA states that applicants who move forward before permit issuance bear the risk that a permit may be denied or issued with unexpected conditions.
- Conforming changes and consistency: EPA proposes corresponding revisions across prevention of significant deterioration (PSD), nonattainment NSR (NNSR), and Tribal NSR regulations, including updated terminology and aligned definitions, to ensure consistency across NSR programs.
If finalized, the rule would give project proponents more flexibility to advance certain site work before obtaining an NSR permit, potentially reducing project delays and front-end permitting friction.
That said, the proposal would not reduce substantive permitting obligations for pollutant-emitting units, and pre-permit work would remain an economic risk if a permit is denied or issued with material conditions.
EPA is also seeking comment on whether to expand the exclusion list and whether the rules should expressly bar permitting authorities from considering applicant economic losses when a permit cannot be issued.
