---
title: "Which facilities need a Clean Air Act operating permit? Answer in under 100 words. Cite only eCFR (www.ecfr.gov) sources."
canonical: https://www.m-i-n-d.ai/minds/environmental/clean-air-act-operating-permit-applicability
jurisdiction: "US Federal"
last_verified: 2026-08-27
license: CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/
attribution: "Source: MIND (m-i-n-d.ai)"
---

# Which facilities need a Clean Air Act operating permit? Answer in under 100 words. Cite only eCFR (www.ecfr.gov) sources.

Under 40 CFR 70.3(a), a State operating permit program with whole or partial approval must provide for permitting of: (1) any major source; (2) any source subject to a standard, limitation, or other requirement under section 111 of the Clean Air Act; (3) any source subject to a standard or requirement under section 112 of the Act (except section 112(r)); (4) any affected source; and (5) any source in a category designated by the Administrator. Solid waste incineration units under section 129(e) are also Part 70 sources and cannot be exempted as nonmajor sources.

## Details / How it works

Section 70.3(a) of 40 CFR Part 70 lists five categories of Part 70 sources that a State program (with whole or partial approval) must provide for permitting. A source becomes a Part 70 source if it is a major source, an affected source, a solid waste incineration unit required to obtain a permit under section 129(e) of the Act, a source subject to section 111 or section 112 standards (other than section 112(r) alone), or a source in an Administrator-designated category.

## Numbers & thresholds

| Trigger | Permit Required? | Notes |
|---|---|---|
| Major source | Yes | Defined elsewhere in Part 70 |
| Subject to section 111 standard | Yes | Includes area sources |
| Subject to section 112 standard | Yes | Excludes section 112(r) alone |
| Affected source | Yes | As defined in the Act |
| Source in Administrator-designated category | Yes | Per § 70.3(a)(5) |
| Solid waste incineration unit under section 129(e) | Yes | Cannot be exempted as nonmajor |

## Exceptions & edge cases

Under § 70.3(b)(1), nonmajor Part 70 sources may be exempted by the State until the Administrator completes a rulemaking on structuring the program for nonmajor sources. However, solid waste incineration units subject to section 129(e) and affected sources are excluded from this nonmajor exemption. Under § 70.3(b)(4), sources subject only to Part 60, Subpart AAA (residential wood heaters) or Part 61, Subpart M § 61.145 (asbestos demolition/renovation) are categorically exempted.

## Sources

- [1] U.S. Government Publishing Office / Environmental Protection Agency — 40 CFR 70.3 — State operating permit programs — applicability under the Clean Air Act · https://www.ecfr.gov/current/title-40/section-70.3 · as of 2026-08-27