Approval and Promulgation of Implementation Plans; Tennessee: Approval of Revisions to the Knox County Portion of the Tennessee State Implementation Plan

EPA is approving revisions to the State Implementation Plan (SIP) submitted by the State of Tennessee, through Tennessee Department of Environment and Conservation (TDEC), on August 18, 1999 and July 16, 2001. The revisions pertain to the Knox County portion of the Tennessee SIP and include changes to the Knox County Air Quality Regulations (KCAQR) Section 51.0--Standards for Cement Kilns. These standards set nitrogen oxides (NO<INF>X</INF>) emissions control, compliance demonstration, certification, record keeping, and reporting requirements for Portland cement kilns in the County. The revisions were initially reviewed by TDEC, which found them to be as stringent as the State's requirements. The proposed changes are part of the Knox County strategy to meet the national ambient air quality standards (NAAQS) by reducing the emissions of NO<INF>X</INF>, a precursor of ozone formation. Because of the harmful health effects of ozone, EPA limits the amount of volatile organic compounds and NO<INF>X</INF> that can be released into the atmosphere. This action is being taken pursuant to section 110 of the Clean Air Act (CAA).