Air Plan Approval; Arizona; Attainment Plan for the Hayden SO2 Nonattainment Area for the 1971 and 2010 Sulfur Dioxide National Ambient Air Quality Standards
Built by the Tribune's code from the Federal Register. No AI wrote this page. Published in the Federal Register Aug. 20, 2026. Document 2026-16989. Updated Nov. 6, 2026.
- What it does
The Environmental Protection Agency (EPA) is finalizing approval of revisions to the Arizona state implementation plan (SIP) for attaining the 1971 and 2010 sulfur dioxide (SO<INF>2</INF>) national ambient air quality standards (NAAQS or "standards") in the Hayden SO<INF>2</INF> nonattainment area. These SIP revisions, collectively referred to as the "Hayden SO<INF>2</INF> Plan" or "Plan," include Arizona's attainment demonstration and other elements required under Clean Air Act (CAA or "Act") sections 110, 172, 191, and 192. In addition to an attainment demonstration, the revisions address the requirements for meeting reasonable further progress (RFP) toward attainment of the NAAQS, reasonably available control measures and reasonably available control technology (RACM/RACT), base-year and projection-year emissions inventories, nonattainment new source review, emissions limitations necessary to provide for attainment, and contingency measures. The EPA is approving the SIP revisions as meeting the CAA requirements. This action is being taken under the CAA.
The Environmental Protection Agency's summary, as published in the Federal Register.
- What changed in the regulation
1 part of Title 40 of the Code of Federal Regulations:
Wording on eCFR: the day before it took effect and from the day it took effect (first part listed).
- Compared with
The Environmental Protection Agency has published 243 final rules in 2026 so far, compared with 263 in all of 2025.
Counted by the Tribune from Federal Register records since Jan. 1, 2025.
- What happens next and when
This rule is effective September 21, 2026.
The agency's dates, word for word.
The record as published
| Document number | 2026-16989 |
|---|---|
| Action | Final rule. |
| Agencies | Environmental Protection Agency |
| Published | Aug. 20, 2026 |
| Effective date | Sept. 21, 2026 |
| Docket | EPA-R09-OAR-2025-3821 |
Source: the Federal Register (public domain). The document in the Federal Register