Determination of Attainment by the Attainment Date; 1997 Ozone Standards; California; Coachella Valley
Key claim: EPA has determined that California’s Coachella Valley attained the revoked 1997 ozone air quality standard by its June 15, 2025 deadline, based on 2022–2024 monitoring data.
Abstract
(Rule · Environmental Protection Agency) The Environmental Protection Agency (EPA) is taking final action to determine that the Riverside County (Coachella Valley), CA 1997 ozone “Extreme” nonattainment area attained the revoked 1997 ozone national ambient air quality standards (NAAQS) by its June 15, 2025 attainment date. This determination is based on quality-assured and certified ambient air quality monitoring data from 2022 through 2024.
Why this matters
Attainment-by-attainment-date findings under a revoked NAAQS still carry legal weight because they close out anti-backsliding obligations (contingency measures, fee programs, and Section 185 penalty fees) that would otherwise attach to a failure-to-attain finding for an Extreme area like the Coachella Valley. For California, this determination narrows ongoing SIP obligations tied to the 1997 standard even as the region remains nonattainment for later, tighter ozone standards. It illustrates the layered, standard-by-standard structure of ozone regulation in California’s chronic nonattainment basins.