Approval and Promulgation of Air Quality Implementation Plans; Oklahoma; Infrastructure for the Lead, Ozone, Nitrogen Dioxide and Sulfur Dioxide National Ambient Air Quality Standards

Under the Federal Clean Air Act (CAA or Act), the Environmental Protection Agency (EPA) is proposing to approve State Implementation Plan (SIP) submissions from the State of Oklahoma regarding the 2008 Lead (Pb), 2008 Ozone, 2010 Nitrogen Dioxide (NO2), and 2010 Sulfur Dioxide (SO2) National Ambient Air Quality Standards (NAAQS or standards). The four submittals address how the existing SIP provides for implementation, maintenance, and enforcement of these four NAAQS (infrastructure SIP or i-SIP). These i-SIPs ensure that the Oklahoma SIP is adequate to meet the State's responsibilities under the Act, including the CAA requirements for interstate transport of Pb and NO2 emissions.