The Environmental Protection Agency (EPA) is taking final action to conditionally approve a portion of a State Implementation Plan (SIP) revision submitted by the State of Tennessee, through the Tennessee Department of Environment and Conservation (TDEC) with a letter dated February 27, 2017, to establish a SIP-approved state control program to comply with the obligations of the Nitrogen Oxides (NO<INF>X</INF>) SIP Call with respect to certain sources. EPA is also taking final action to fully approve the remaining portion of the same Tennessee SIP revision to remove the SIP-approved portions of the State's Clean Air Interstate Rule (CAIR) Program rules from the Tennessee SIP. In addition, EPA is also fully approving a revision to the Tennessee SIP submitted with a letter dated April 3, 2018, to remove regulations related to a previous NO<INF>X</INF> trading program.