Final rule · 2025-00336

State Implementation Plan Submittal Deadlines and Implementation Requirements for Reclassified Nonattainment Areas Under the Ozone National Ambient Air Quality Standards

The Environmental Protection Agency (EPA) is finalizing deadlines for submission of state implementation plan (SIP) revisions and implementation of the relevant control requirements that will apply for nonattainment areas reclassified as Moderate, Serious, and Severe under the current and any future ozone National Ambient Air Quality Standards (NAAQS) as a result of either failing to attain the standard by the applicable classification attainment date or the EPA granting a voluntary reclassification request. This final rule articulates the implementation requirements and timeframes that will apply for all such areas once reclassified. The EPA is also finalizing regulatory revisions to codify its existing interpretation that following reclassification, a state is no longer required to submit SIP revisions addressing certain, but not all, requirements related to the prior classification level for an ozone nonattainment area.