Final rule · 2025-20095

Air Plan Approval; Arizona; Yuma 2015 8-Hour Ozone Nonattainment Area; Redesignation Request and Maintenance Plan

The Environmental Protection Agency (EPA) is taking final action to approve the State of Arizona's "SIP Revision: 2015 Ozone NAAQS, Yuma Redesignation Request and Maintenance Plan" ("Yuma Maintenance Plan" or "Plan") as a revision to the Arizona state implementation plan (SIP). The Yuma Maintenance Plan includes, among other elements, an emissions inventory consistent with attainment, a maintenance demonstration, contingency provisions, and a motor vehicle emissions budget for use in transportation conformity determinations for the ten-year maintenance period. With this action, the EPA is approving the motor vehicle emissions budgets for 2020, 2030, and 2037. The EPA is also approving the State's request to redesignate the Yuma nonattainment area ("Yuma area") from nonattainment to attainment for the 8-hour national ambient air quality standards (NAAQS) for ozone promulgated in 2015 ("2015 ozone NAAQS"). The EPA is finalizing this action because this SIP revision meets the applicable Clean Air Act (CAA or "Act") requirements for maintenance plans and because the State has met the requirements under the Act for redesignation of a nonattainment area to attainment with respect to the Yuma area.