Section 52.174 - Control strategy and regulations: Ozone(a) The EPA has determined that the Crittenden County Marginal 2008 ozone NAAQS nonattainment area attained the NAAQS by the applicable attainment date of July 20, 2015.(b) The portion of the SIP submittal from October 10, 2019, addressing Clean Air Act section 110(a)(2)(D)(i)(I) for the 2015 ozone national ambient air quality standards (NAAQS) is disapproved. 81 FR 26708 , May 4, 2016, as amended at 88 FR 9381 , Feb. 13, 2023 81 FR 26708 , 5/4/2016; 88 FR 9381 3/15/2023