Pursuant to the Federal Clean Air Act (CAA), the Environmental Protection Agency (EPA) is granting a request from the Governor of the State of Texas to voluntarily reclassify the San Antonio, Dallas-Fort Worth (DFW), and Houston-Galveston-Brazoria (HGB) ozone nonattainment areas from Moderate to Serious for the 2015 ozone National Ambient Air Quality Standards (NAAQS). The EPA is also setting the date for the Texas Commission on Environmental Quality (TCEQ or State) to submit revised State Implementation Plans (SIPs) addressing the Serious ozone nonattainment area requirements and for the first transportation control demonstrations for these areas. The EPA is also setting the deadlines for implementation of new rules addressing Reasonably Available Control Technology (RACT) and for any new or revised Enhanced vehicle Inspection and Maintenance (I/M) programs. Finally, the TCEQ is no longer required to submit SIP revisions addressing the following requirements related to the prior classification level for these three ozone nonattainment areas: a demonstration of attainment by the prior attainment date; a Reasonably Available Control Measures (RACM) analysis tied to the prior attainment date; and contingency measures specifically related to the area's failure to attain by the prior attainment date.