Approval of Air Quality State Implementation Plans; 2012 PM2.5 Interstate Transport Requirements

The Clean Air Act (CAA) requires each state implementation plan (SIP) to contain adequate provisions prohibiting emissions that will significantly contribute to nonattainment or interfere with maintenance of air quality in other states. The State of Arizona submitted SIP revisions to the Environmental Protection Agency (EPA) to address these requirements for the 2012 fine particulate (PM2.5) national ambient air quality standards (NAAQS). The EPA is proposing to approve Arizona's SIP submission as meeting the requirement that the Arizona SIP contains adequate provisions to prohibit emissions activity, within the State, from emitting air pollutants in amounts that will significantly contribute to nonattainment or interfere with maintenance of the 2012 PM2.5 NAAQS in any other state.