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PROPOSED RULECOMMENTS CLOSED OCTOBER 14, 2026

Clean Data Determination; 1997 8-Hour Ozone Standards; California; Sacramento Metro Area

Environmental Protection Agency

The U.S. Environmental Protection Agency (EPA or "Agency") is proposing to issue a clean data determination (CDD) for the Sacramento Metro, California nonattainment area to reflect our finding that the area is attaining the 1997 8-hour ozone national ambient air quality standards (NAAQS or "standards"). This finding is based on quality-assured and certified ambient air quality monitoring data from 2023 through 2025. If we finalize this CDD, certain Clean Air Act (CAA) requirements that apply to the Sacramento Metro area will be suspended for so long as the area continues to attain the 1997 8-hour ozone NAAQS. We are taking comments on this proposal and plan to follow with a final action.

Published September 14, 2026Document 2026-18755

What happens next

The comment period closed on October 14, 2026. The agency now reviews the comments. If it goes ahead, it publishes a final rule in the Federal Register that responds to significant comments. We link it here when it appears. See what is open for comment now.

From the Federal Register as of November 3, 2026. Deadlines can change; the official document governs. Not legal advice.

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