Proposed rule · 2026-12551

Approval and Promulgation of Implementation Plans; Arizona; Revisions to the Cleaner Burning Gasoline, Winter Oxygenated Fuel, and Gasoline Set-Aside Programs

The Environmental Protection Agency (EPA) is proposing to approve a revision to the Arizona State Implementation Plan (SIP) submitted by the Arizona Department of Environmental Quality (ADEQ). This revision includes statutes and regulations amending the Cleaner Burning Gasoline (CBG) program, which is a control measure in the greater Phoenix metropolitan area to reduce emissions of ozone-forming pollutants, carbon monoxide (CO), and particulate matter. Additionally, this revision addresses the Winter Oxygenated Fuel program to control CO emissions in the Tucson area. Finally, this revision repeals the Arizona Gasoline Set[hyphen]aside (GSA) Program, applicable to the 1971 carbon monoxide nonattainment area covering Maricopa County and a portion of Pima County. The EPA is proposing to approve this SIP revision under the Clean Air Act (CAA or "Act"). This SIP revision is administrative in nature. This action proposes to update the existing SIP-approved CBG program with revisions that have been adopted and implemented by the State to clarify requirements, update references, and enhance flexibility of the program, and it will not impose any additional costs or regulatory burdens. We are taking comments on this proposal and plan to follow with a final action.