Approval and Promulgation of Implementation Plans; California; San Joaquin Valley, Revisions to Motor Vehicle Emissions Budgets for Ozone

What it does

The U.S. Environmental Protection Agency (EPA or "Agency") is taking final action to approve a revision to the State of California's state implementation plan (SIP) for the San Joaquin Valley (SJV) area. The revision includes an update to the SJV area's motor vehicle emissions budgets ("budgets") for nitrogen oxides (NO<INF>X</INF>) and volatile organic compounds (VOC) for the 2008 8- hour ozone national ambient air quality standards (NAAQS or "standards"). These updated budgets for 2026, 2029, and 2031 were developed with the latest modeling method approved for California. These updated budgets apply to all subareas within the SJV. Upon the effective date of this rule, the updated budgets will supersede the existing approved SJV subarea budgets for the 2008 ozone NAAQS that were based on an earlier emissions model. The EPA is approving the updated SJV ozone budgets in accordance with the requirements of the Clean Air Act (CAA or "Act") and the EPA's regulations.

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 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 October 14, 2026.

The agency's dates, word for word.

Check it yourself

• The document in the Federal Register
• Docket EPA-R09-OAR-2026-3400 on Regulations.gov
• Title 40 on eCFR

The record as published

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