Section 52.939 - Original identification of plan section(a) This section identified the original "Air Implementation Plan for the State of Kentucky" and all revisions submitted by Kentucky that were federally approved prior to March 1, 1999. The information in this section is available in the 40 CFR, part 52 edition revised as of July 1, 1999, the 40 CFR, part 52, Volume 1 of 2 (§§ 52.01 to 52.1018 ) editions revised as of July 1, 2000 through July 1, 2011, and the 40 CFR, part 52, Volume 1 of 3 (§§ 52.01 to 52.1018 ) editions revised as of July 1, 2012. The Jefferson County portion of the Commonwealth of Kentucky's SIP previously identified in section 52.934(a) and(b) is also available in the above editions. 79 FR 30051 , May 27, 2014