EPA wants to let you start non-emitting site work before your NSR permit clears. Here's the catch.

TL;DR. EPA published a proposed rule on May 13, 2026 (Federal Register document 2026-09524) that would clarify the definition of “begin actual construction” under the New Source Review (NSR) air permitting program. Under the proposal, you would be allowed to start construction of non-emitting components and structures (foundations, parking, certain utilities) before EPA issues an NSR permit. The compliance burden the rule imposes is small: SBCIS Impact Score 5.5 out of 25, roughly $480 to $720 a year and 24 hours of legal review per affected SMB. The burden it relieves, for firms actively pursuing major-source permits, is potentially material. The comment period closes June 29, 2026.

Who is affected

• SMBs operating or planning a “major stationary source” of air pollution under EPA’s NSR program. In practice that means certain operations in NAICS 22 (Utilities), NAICS 23 (Construction, specifically heavy and civil engineering construction), NAICS 31-33 (Manufacturing, especially primary metals, cement, chemicals, paper, food processing at scale, and minerals), and NAICS 21 (Mining).
• Permittees in Indian country are also in scope through the minor NSR regulations.
• Approximately 5 to 10 percent of SMBs in those NAICS bands have facilities at or near major-source thresholds; everyone else is unaffected.

If you do not operate a stationary source of regulated air emissions, this proposal does not touch you.

What the rule does

The proposed rule revises three things:

1. The definition of “begin actual construction” in the Federal NSR regulations for both Nonattainment New Source Review (NNSR) and Prevention of Significant Deterioration (PSD). Under the current definition, almost any on-site activity that breaks ground at a planned major source can be characterized as “begin actual construction,” which is prohibited before an NSR permit is issued. The proposed revision would distinguish between construction of an actual pollutant-emitting stationary source and construction of “non-emitting components or structures” (think site grading, foundations, building shells that don’t yet house emitting equipment, utility connections).
2. Adds a new definition for “pollutant-emitting activities” to draw the line precisely.
3. Conforming changes to “begin construction” and “commence construction” in the Federal minor NSR regulations for Indian country.

In plain terms: under current EPA practice, owners of planned major sources have to wait for the NSR permit to break any ground at all. The proposal would let you do non-emitting site work in parallel with the permit review, while still prohibiting the construction of any actual emitting equipment until the permit is issued.

EPA frames this as a “clarification and codification” of distinctions that have been informally recognized in some EPA regions and through the courts for years. The rule does not change the underlying NSR requirements; it draws a clearer line about timing.

What it costs (SBCIS walkthrough)

Under SBCIS v1.0, this rule scores in the low bucket: Impact Score 5.5 out of 25.

• Capex axis is 0. The proposal requires no new equipment, no software, no facility modifications.
• Opex axis is 0.5. Affected SMBs should expect a modest legal review cost (one hour of outside counsel at typical rates, plus a possible comment-filing cost), estimated at roughly $600 a year in the first year and trailing off.
• Hours axis is 1.5. Roughly 24 hours per affected SMB per year to read the rule, brief counsel, evaluate the firm’s specific permitting situation, and file a comment if relevant. Most of this is one-time in 2026.
• Applicability axis is 2.0. Affected SMBs are a subset of NAICS 21, 22, 23, and 31-33 with major-source emission potential. That’s roughly 5 to 10 percent of SMBs in those bands, or approximately 1 to 2 percent of all US SMBs.
• Edge severity axis is 1.5. Firms actively in NSR permitting review may see relative impact above the median, but the burden side is modest.

The dollar estimate per representative 25-employee SMB is $480 to $720 per year, plus 24 hours.

Two things SBCIS v1.0 does not capture here, and that you should know:

1. SBCIS scores the burden a rule imposes, not the burden it relieves (methodology Section G.2). This rule actively reduces a long-standing scheduling burden for firms with active major-source projects. The score does not show that. Practically: if you are sitting on a $20M facility expansion waiting for NSR approval, this proposal would let your contractor start the non-emitting work months earlier. That can be worth tens or hundreds of thousands of dollars in carrying-cost reduction. SBCIS will not put a number on the relief side until v2.0.
2. The rule does not relax NSR substantive requirements. You still need the permit before any emitting activity. Mis-reading the line between “non-emitting” and “emitting” remains a violation risk, and EPA’s compliance enforcement on NSR violations has historically been aggressive.

What to do

1. Read the proposed rule at the Federal Register URL in the citations above. The preamble is the substantive part; the operative regulatory text is at the back.
2. If you are actively pursuing or expecting to pursue an NSR permit, talk to your environmental counsel about whether this proposal materially changes your project timeline. The biggest practical effect is unlocking parallel-track scheduling of site preparation.
3. If you are affected, consider filing a comment by June 29, 2026. The Federal Register notice includes the comment submission instructions; the comment URL is at regulations.gov. Comments that include specific cost and timing data from real projects carry weight at OIRA review and in any final-rule preamble.
4. If you operate under a state-implemented NSR program (most do), watch your state’s adoption timeline once a final rule is issued. State adoption typically lags by 12 to 36 months.

Related context

This proposal is part of a broader 2025 to 2026 EPA effort to clarify timing and scope under several Clean Air Act permitting programs. SBCIS will score future Clean Air Act permitting changes consistently as they ship. The OSHA-side calibration example in the SBCIS v1.0 methodology document covers a different cost shape (capital-equipment retrofit) and is a useful contrast to the present rule’s near-zero capex profile.

Other regulations RegImpact is tracking for SMB operators

The methodology that produced this score applies just as well to non-EPA rules. A few related entries from the RegImpact regulations tracker that touch the same SMB-compliance-burden surface from different angles:

• Small Business Guide to the AI Act, which walks through the EU AI Act’s tiered obligations for SMBs and is the closest analogue to SBCIS for a different regulatory regime.
• Build America: Eliminating Barriers to Wireless Deployments, an FCC proceeding that explicitly addresses regulatory-burden reduction in build-and-construction permitting workflows.
• Premerger Notification Reporting and Waiting Period Requirements, an FTC rule update where the reporting-burden axis dominates the cost calculation, similar to several of the SBCIS Section H worked examples.

If you operate in any of those rules’ scopes, the same scan-your-business mechanic at regimpact.dev applies.