Proposed rule · 2025-13339

Determination of Attainment by the Attainment Date and Clean Data Determination; California, San Joaquin Valley 1997 Annual PM2.5 Fine Particulate Matter Nonattainment Area

The Environmental Protection Agency (EPA) is proposing to determine that the San Joaquin Valley, California fine particulate matter (PM<INF>2.5</INF>) nonattainment area attained the 1997 annual PM<INF>2.5</INF> national ambient air quality standards (NAAQS) by the December 31, 2024 applicable attainment date. This proposed determination is based on ambient air quality monitoring data from 2022 through 2024. We are also proposing to make a clean data determination (CDD) based on the 2022 through 2024 data and our evaluation of preliminary air quality monitoring data from 2025. We are taking comments on this proposal and plan to follow with a final action.