Determination of Attainment by the Attainment Date But for International Emissions for the 2015 Ozone National Ambient Air Quality Standards; Phoenix-Mesa Nonattainment Area, Arizona

Document 2026-05601 is a Final Rule published by the Environmental Protection Agency in the Federal Register on March 23, 2026, with an effective date of April 22, 2026. The Environmental Protection Agency (EPA or "Agency") is taking final action to determine that the Phoenix-Mesa nonattainment area ("Phoenix-Mesa area") would have attained the 2015 ozone national ambient air quality standards (NAAQS or "standards") by the August 3, 2024 "Moderate" area attainment date, but for emissions emanating from outside the United States. As a consequence of this action, the Phoenix-Mesa area is not subject to the Clean Air Act (CAA) requirements pertaining to reclassification upon failure to attain and remains classified as a Moderate nonattainment area for the 2015 ozone NAAQS. This final action fulfills the EPA's statutory obligation to determine whether the Phoenix-Mesa area attained the NAAQS by the attainment date. As a result of this final action, the State is no longer required to submit attainment and reasonable further progress (RFP) contingency measures for this area. View the original at https://www.federalregister.gov/documents/2026/03/23/2026-05601/determination-of-attainment-by-the-attainment-date-but-for-international-emissions-for-the-2015.

No. Document 2026-05601 is not classified as economically significant under Executive Order 12866. Economically significant rules require OIRA review and are estimated to have impacts of $100 million or more per year.