The Environmental Protection Agency (EPA) is taking direct final action to approve a portion of a revision to the Tennessee State Implementation Plan (SIP) submitted on March 14, 2014, by the State of Tennessee, through the Tennessee Department of Environmental Conservation (TDEC) on behalf of the Knox County Department of Air Quality Management (Knox County) to address changes to a Knox County regulation regarding permits. EPA has determined that Tennessee's requested SIP revision is consistent with the applicable provisions of the Clean Air Act (CAA or Act).