Pursuant to the Clean Air Act (CAA or the Act), the Environmental Protection Agency (EPA) is approving elements of two State Implementation Plan (SIP) submissions from the State of Texas for the 2015 Ozone National Ambient Air Quality Standard (NAAQS). These submittals address how the existing SIP provides for implementation, maintenance, and enforcement of the 2015 ozone NAAQS (infrastructure SIP or i-SIP).