The Environmental Protection Agency (EPA) is approving elements of a State Implementation Plan (SIP) submission from the State of New Mexico for the Sulfur Dioxide (SO<INF>2</INF>) National Ambient Air Quality Standards (NAAQS). The submittal addresses how the existing SIP provides for implementation, maintenance, and enforcement of the 2010 SO<INF>2</INF> NAAQS (infrastructure SIP or i-SIP), including two of the four CAA requirements for interstate transport of SO<INF>2</INF> emissions. This i-SIP ensures that the State's SIP is adequate to meet the state's responsibilities under the Federal Clean Air Act (CAA).