Regulations last checked for updates: Feb 11, 2026

Title 40 - Protection of Environment last revised: Dec 22, 2026
§ 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]
authority: 42 U.S.C. 7401
cite as: 40 CFR 52.174