Air Plan Approval and Air Quality Designation; TN; Redesignation of the Knoxville 2006 24-Hour PM2.5

On December 20, 2016, Tennessee, through the Tennessee Department of Environment and Conservation (TDEC), submitted a request for the Environmental Protection Agency (EPA) to redesignate the Knoxville-Sevierville-La Follette, TN fine particulate matter (PM2.5) nonattainment area (hereinafter referred to as the ``Knoxville Area'' or ``Area'') to attainment for the 2006 24-hour PM2.5 national ambient air quality standards (NAAQS) and to approve a state implementation plan (SIP) revision containing a maintenance plan and a reasonably available control measures (RACM) determination for the Area. EPA is proposing to approve Tennessee's RACM determination for the Knoxville Area and incorporate it into the SIP; to approve Tennessee's plan for maintaining the 2006 24-hour PM2.5 NAAQS for the Knoxville Area (maintenance plan), including the associated motor vehicle emission budgets (MVEBs) for nitrogen oxides (NOx) and PM2.5 for the years 2014 and 2028, and incorporate it into the SIP; and to redesignate the Knoxville Area to attainment for the 2006 24-hour PM2.5 NAAQS.