Proposed rule · 2026-18755

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

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.