Clean Air Plans; 2008 8-Hour Ozone Nonattainment Area Requirements; Phoenix-Mesa, Arizona

The Environmental Protection Agency (EPA) is taking final action on a state implementation plan (SIP) revision submitted by the State of Arizona on behalf of the Maricopa Association of Governments (MAG) to meet Clean Air Act (CAA or "the Act") requirements for the 2008 ozone national ambient air quality standards (NAAQS or "standards") in the Phoenix-Mesa ("Phoenix") ozone nonattainment area (NAA). The EPA is finalizing approval of the portions of the "MAG 2017 Eight-Hour Ozone Moderate Area Plan for the Maricopa Nonattainment Area (December 2016)" ("MAG 2017 Ozone Plan" or "Plan") that address the requirements for emissions inventories, a demonstration of attainment by the applicable attainment date, reasonably available control measures (RACM), reasonable further progress (RFP), motor vehicle emission budgets for transportation conformity, vehicle inspection and maintenance (I/M) programs, new source review (NSR) rules, and offsets. The EPA is finalizing a disapproval of the portion of the MAG 2017 Ozone Plan that addresses the requirements for contingency measures for failure to attain or to make RFP. However, based on a separate finding that the Phoenix 2008 ozone NAA ("Phoenix NAA") attained the 2008 ozone standards by the applicable attainment date, we previously determined that the requirement for the State to submit a SIP revision addressing attainment contingency measures no longer applies for the Phoenix NAA. We are also finalizing our determination that the requirement for the State to submit a SIP revision addressing RFP contingency measures no longer applies for the Phoenix NAA. Finally, we are finalizing approval of the portions of a SIP revision, the "MAG 2014 Eight-Hour Ozone Plan--Submittal of Marginal Area Requirements for the Maricopa Nonattainment Area (June 2014)" ("MAG 2014 Ozone Plan"), on which we previously deferred action.