Designation of Areas for Air Quality Planning Purposes; Michigan; Technical Amendment

What it does

The Detroit, Michigan area was redesignated to attainment of the 2015 ozone National Ambient Air Quality Standards (NAAQS) on May 19, 2023. On December 5, 2025, the United States Court of Appeals for the Sixth Circuit vacated the Environmental Protection Agency's (EPA's) redesignation of the Detroit area. Therefore, pursuant to the Court's decision, the EPA is making a technical amendment to the part 81 listing for the Detroit area to reflect the area's designation as nonattainment for the 2015 ozone NAAQS, with a classification of Moderate.

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:

40 CFR 81

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 final rule is effective on June 29, 2026.

The agency's dates, word for word.

Check it yourself

• The document in the Federal Register
• Docket EPA-R05-OAR-2022-0004 on Regulations.gov
• Title 40 on eCFR

The record as published

Source: the Federal Register (public domain). The document in the Federal Register