Approval of Clean Air Plans; San Joaquin Valley, California; Contingency Measures for 1997 Ozone Standards

What it does

The Environmental Protection Agency (EPA) is taking final action to approve under the Clean Air Act (CAA or "Act") a state implementation plan (SIP) submission from the State of California as meeting the attainment-related contingency measure requirements for the 1997 ozone national ambient air quality standards (NAAQS or "standards") in the San Joaquin Valley, California, Extreme ozone nonattainment area. The SIP revision is titled "California Smog Check Contingency Measure State Implementation Plan Revision" (September 15, 2023) ("Smog Check Contingency Measure SIP"). The EPA's approval relies on the previously approved contingency measure for the 1997 ozone NAAQS for the San Joaquin Valley and the justifications for not adopting additional contingency measures that provide for the recommended amount of emissions reductions for such measures. Based on our final approval, the EPA is also finalizing our determination that the State of California has fulfilled the commitment made by the State in connection with a previous approval action to develop, adopt, and submit attainment contingency measures for the San Joaquin Valley Extreme nonattainment area for the 1997 ozone NAAQS meeting the requirements of 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:

40 CFR 52

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 245 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 action is effective April 22, 2026.

The agency's dates, word for word.

Check it yourself

• The document in the Federal Register
• Docket EPA-R09-OAR-2025-2466 on Regulations.gov
• Title 40 on eCFR

The record as published

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