Determinations of Attainment by the Attainment Date, Extensions of the Attainment Date, and Reclassification of Areas Classified as Marginal for the 2015 Ozone National Ambient Air Quality Standards
The Environmental Protection Agency (EPA or Agency) is proposing three actions pursuant to section 181(b)(2) of the Clean Air Act (CAA) related to the attainment date for 31 areas classified as ``Marginal'' nonattainment for the 2015 ozone National Ambient Air Quality Standards (NAAQS). First, the Agency is proposing to determine that six areas attained the standard by the applicable August 3, 2021, attainment date. Second, the Agency is proposing to grant a 1-year attainment date extension for the Uinta Basin, Utah, nonattainment area. Third, the Agency is proposing to determine that 24 areas failed to attain the standard by their applicable attainment date and. The effect of failing to attain by the attainment date is that such areas will be reclassified by operation of law to ``Moderate'' upon the effective date of the final reclassification notice. Consequently, the responsible state air agencies must submit state implementation plan (SIP) revisions required to satisfy the statutory and regulatory requirements for Moderate areas for the 2015 ozone NAAQS. The EPA proposes deadlines for submission of those SIP revisions and implementation of the related control requirements. This action, when finalized, will fulfill the EPA's statutory obligation to determine whether ozone nonattainment areas attained the NAAQS by the attainment date and to publish a document in the Federal Register identifying each area that is determined as having failed to attain and identifying the reclassification. Several areas included in this proposed rule are also addressed in a separate rulemaking to determine whether areas classified as ``Serious'' for the 2008 ozone NAAQS attained the standard by the applicable attainment date of July 20, 2021 (see Docket ID EPA-HQ-OAR-2021-0741).