The EPA is approving a revision to the State Implementation Plan (SIP) submitted by the Chairman of the Texas Commission on Environmental Quality (TCEQ) on December 6, 2004. The revision incorporates into the SIP a vehicle inspection and maintenance (I/M) program for Travis and Williamson Counties. The program is a control measure adopted as part of the Austin Early Action Compact (EAC). EPA is approving this revision as a strengthening of the SIP, in accordance with the requirements of sections 110 and 116 of the Federal Clean Air Act (the Act), which will result in emission reductions needed to help ensure attainment of the 8-hour National Ambient Air Quality Standard (NAAQS) for ozone.