(a) Part D conditional approval. The Chattanooga primary TSP plan's provisions for review of new sources and modifications in the nonattainment area are approved on condition that the State submit by December 31, 1987, a definition of the term Federally enforceable and provisions for making Federally enforceable all limitations, conditions, and offsets, including permit restrictions, relied upon under the plan, and in the interim, implement these provisions in a manner consistent with EPA requirements.

(b) In letters dated March 9 and April 15, 1988, the Tennessee Department of Health and Environment certified that no emission limits in the State's plan are based on dispersion techniques not permitted by EPA's stack height rules. This certification does not apply to: Dupont (43-07-02); Tennessee Valley Authority - Johnsonville (43-11-1 thru 10); Tennessee Chemical Company (70-04-21); Tennessee Eastman (82-03-15-19); A.E. Staley (53-81-18, 19, 34, 31); Cargill Inc., Memphis; and Grace Chemical Company, Millington.

(c) Determination of Attaining Data. EPA has determined, as of May 31, 2011, the Chattanooga, Tennessee, nonattainment area has attaining data for the 1997 annual PM_2.5 NAAQS. This determination, in accordance with 40 CFR 52.1004(c), suspends the requirements for this area to submit an attainment demonstration, associated reasonably available control measures, a reasonable further progress plan, contingency measures, and other planning SIPs related to attainment of the standard for as long as this area continues to meet the 1997 annual PM_2.5 NAAQS.

(d) Determination of attaining data. EPA has determined the Knoxville, Tennessee, nonattainment area has attaining data for the 1997 annual PM_2.5 NAAQS. This determination, in accordance with 40 CFR 51.1004(c), suspends the requirements for this area to submit an attainment demonstration, associated reasonably available control measures, a reasonable further progress plan, contingency measures, and other planning SIPs related to attainment of the standard for as long as this area continues to meet the 1997 annual PM_2.5 NAAQS.

(e) Determination of attaining data. EPA has determined Knoxville-Sevierville-La Follette, Tennessee, nonattainment area has attaining data for the 2006 24-hour PM_2.5 NAAQS. This determination, in accordance with 40 CFR 51.1004(c), suspends the requirements for this area to submit an attainment demonstration, associated reasonably available control measures, a reasonable further progress plan, contingency measures, and other planning SIPs related to attainment of the standard for as long as this area continues to meet the 2006 24-hour PM_2.5 NAAQS.

(f) Determination of attainment. Effective June 9, 2017, the EPA has determined that, based on 2013 to 2015 ambient air quality data, the Knoxville-Sevierville-La Follette, Tennessee PM_2.5 nonattainment area has attained the 2006 24-hour PM_2.5 NAAQS by the applicable attainment date of December 31, 2015. Therefore, the EPA has met the requirement pursuant to CAA section 188(b)(2) to determine whether the area attained the standard. The EPA also has determined that the Knoxville-Sevierville-La Follette, Tennessee nonattainment area will not be reclassified for failure to attain by its applicable attainment date under section 188(b)(2).