The EPA is approving non-regulatory revisions to the Tennessee State Implementation Plan (SIP) and regulatory revisions to the Nashville-Davidson portion of the Tennessee SIP, submitted by the State of Tennessee through the Tennessee Department of Environment and Conservation (TDEC) on January 26, 1999, October 11, 2001, and April 15, 2005. The revisions amend the Vehicle Inspection and Maintenance program in Nashville-Davidson County and the Nashville (Middle Tennessee) 1-Hour Ozone Maintenance Plan.