EPA Would Let a Data Center Break Ground Before Its Air Permit

There are two separate EPA proposals in play, they sit in different dockets, they govern different permitting programs, and the coverage this week has largely merged them. The first, published May 13, 2026 under Docket EPA-HQ-OAR-2025-0618, would rewrite what “begin actual construction” means in the major New Source Review program, the Prevention of Significant Deterioration and Nonattainment NSR rules at 40 CFR 51.165, 51.166, Appendix S to Part 51 and 52.21. The second, published July 7, 2026 under Docket EPA-HQ-OAR-2025-1212, would remove minor NSR public participation as a minimum requirement for a State Implementation Plan under 40 CFR 51.161. One is about when you may put equipment in the ground. The other is about whether the neighbors are told. They are not the same rule and they do not reach the same facilities.

The construction proposal is the operationally larger one. EPA proposes to define “begin actual construction” as the initiation of physical on-site construction of pollutant-emitting activities, and then to list what does not count: engineering and design planning, geotechnical investigation, clearing vegetation, grading, surveying, soil compacting and stabilization including associated pile driving, excavating land including blasting or other removal of hardrock, ordering of equipment and materials, storing equipment or setting up temporary trailers, and paving surfaces. A companion definition of “pollutant-emitting activities” excludes office buildings, retail stores, storage buildings holding inert material, concrete pads and foundations, and walls and roofs that are not closed in on the interior side and carry no design elements uniquely configured to serve emitting equipment, along with HVAC serving human workspaces and the wiring and piping that bring electrical, water, wastewater and telecommunications service to a site. EPA says the list is not exhaustive. Read together, those two definitions describe most of a data center site package short of the generators themselves.

The headline version of this story is that EPA is ending public comment on data center air permits. The rule text does not say that, and the distinction is the whole operator read. Today 40 CFR 51.161 requires three things of a state or local air agency: that the application materials and the agency’s air quality analysis be available for public inspection in the affected area or on a public website, that there be a 30-day comment period, and that notice be given by prominent advertisement in the affected area. Those requirements date to June 18, 1973. What EPA proposes is to stop treating them as a federal minimum that a SIP must contain, on the reasoning that Clean Air Act section 110(a)(2)(C) requires only such regulation of minor source construction “as necessary to assure” the national ambient air quality standards are achieved, and that public participation is generally not necessary to that end. EPA would also delete the transitional provision at 51.161(c).

The part that matters for anyone underwriting a site: EPA states in the proposal that if the rule is finalized, states would be allowed to but would not be required to revise their existing SIP-approved requirements, and that requirements a state does not revise remain in the SIP and continue to apply. Changing them requires a SIP amendment, which itself carries mandatory public participation at the state and local level and during EPA review, and which is ultimately subject to judicial review. So no permit anywhere loses its comment period on the day this is finalized. What would change is that the floor comes out, and states diverge from each other on their own schedules. One more fact worth stating plainly because it cuts against the framing on both sides: the words “data center” do not appear anywhere in the public participation proposal. It is a generic minor source rule. Data centers are one affected category, named by commenters and by the press, not by EPA.

The artifact worth building here is not a regulatory summary, it is a per-site sheet that separates what is decided from what is proposed. Inputs are documents a development team already holds or can pull: the air permit application and its status for each site, the applicable state or local minor NSR rule and whether that state’s SIP-approved public participation provisions are in force, the project schedule with its groundbreaking and long-lead equipment dates, the generator count and rated capacity that drives the permit path, and the construction sequence showing which activities are site work and which are equipment setting. Add two public pulls: the two Federal Register dockets for status changes, and the state air agency’s own rulemaking calendar, because a state SIP amendment is the event that would actually change a project’s obligations.

The output is one row per site with four columns: whether the project is on a major or minor NSR path, what the state requires for public participation today rather than what EPA has proposed, which scheduled activities would fall outside “begin actual construction” if the construction rule is finalized as written, and how much capital those activities represent. That last column is the point of the exercise. An assistant can maintain this sheet, cite the document and section behind every cell, and flag when either docket moves. It should never mark a proposed rule as an effective one, and the sheet should carry the status word on every row. The reviewer is the development lead with environmental counsel, and the approval gate is that no schedule, budget or draw changes on the strength of a proposed rule. PSV takes no position on whether either proposal should be finalized.