Air Plan Approval; Tennessee: Knox County NSR Reform

The Environmental Protection Agency (EPA) is finalizing approval of several Tennessee State Implementation Plan (SIP) revisions submitted by the Tennessee Department of Environment & Conservation (TDEC), on behalf of Knox County's Air Quality Management Division, through letters dated March 7, 2017, and April 17, 2017. The SIP revisions modify the Prevention of Significant Deterioration (PSD) and Nonattainment New Source Review (NNSR) regulations in the Knox County portion of the Tennessee SIP to address changes to the federal new source review (NSR) regulations in recent years for the implementation of the national ambient air quality standards (NAAQS). Additionally, the SIP revisions include updates to Knox County's minor source permitting regulations. This action is being approved pursuant to the Clean Air Act (CAA or Act).