Partial Approval and Partial Disapproval of Air Quality State Implementation Plans; Arizona; Infrastructure Requirements To Address Interstate Transport for the 2008 Ozone NAAQS

The Environmental Protection Agency (EPA) is approving in part and disapproving in part State Implementation Plan (SIP) revisions submitted by the Arizona Department of Environmental Quality to address the interstate transport requirements of Clean Air Act (CAA or Act) section 110(a)(2)(D)(i) with respect to the 2008 ozone national ambient air quality standard (NAAQS). We are approving the portion of the Arizona SIP pertaining to significant contribution to nonattainment or interference with maintenance in another state and disapproving the portion of Arizona's SIP pertaining to interstate transport visibility requirements. Where EPA is disapproving a portion of the Arizona SIP revision, the deficiencies have already been addressed by a federal implementation plan (FIP).