# Air Plan Approval; Michigan; Redesignation and Maintenance Plan for the Partial St. Clair 2010 1-Hour Sulfur Dioxide (SO2) NAAQS Nonattainment Area

**Action Urgency Score:** 30/100

| Field | Value |
|---|---|
| Agency | Environmental Protection Agency |
| Type | Final rule |
| Action | Final rule. |
| Published | 2026-07-09 |
| Effective | 2026-07-09 |
| Significant | No |
| CFR parts | 40 CFR 52, 40 CFR 81 |
| Summary | The Environmental Protection Agency (EPA) is taking final action to redesignate the St. Clair nonattainment area in southeast Michigan to attainment for the 2010 sulfur dioxide (SO<INF>2</INF>) National Ambient Air Quality Standard (NAAQS). The EPA is also approving Michigan's maintenance plan for the St. Clair SO<INF>2</INF> nonattainment area and emissions limits for the DTE Belle River Power Plant. Michigan submitted the request for approval of the St. Clair area redesignation and maintenance plan on December 14, 2023, with a supplement to the request on July 24, 2025. The EPA proposed to a |
| Document number | 2026-13843 |

## Why this score
- Final rule.

Source: Federal Register API (Office of the Federal Register) (https://www.federalregister.gov/documents/2026/07/09/2026-13843/air-plan-approval-michigan-redesignation-and-maintenance-plan-for-the-partial-st-clair-2010-1-hour). Last refreshed: 2026-11-04T21:40:49.974Z.
Data from the Federal Register API; the published Federal Register document is authoritative. Informational only, not legal advice.