Approval and Promulgation of Implementation Plans and Designation of Areas for Air Quality Planning Purposes; Arizona

الملخص

EPA is proposing to approve the Maricopa Association of Governments (MAG) serious area carbon monoxide (CO) state implementation plan (SIP) for the Maricopa County CO nonattainment area (the metropolitan Phoenix area, Arizona) as meeting the Clean Air Act (CAA) requirements for serious CO nonattainment areas. We are also proposing to approve the MAG CO redesignation request and maintenance plan for the Maricopa County CO nonattainment area as meeting CAA requirements for redesignation requests and maintenance plans. In addition, we are proposing to make a boundary change under Section 107 of the CAA to take the Gila River Indian Community (GRIC) out of the Maricopa County maintenance area. The portion of the Gila River Indian Community which is currently in the Maricopa County CO nonattainment area will be "unclassifiable/attainment" for CO, and will not be subject to the MAG CO Redesignation Request and Maintenance Plan.