Approval of Missouri Air Quality Implementation Plans; Redesignation of the Missouri Portion of the St. Louis-St. Charles-Farmington, MO-IL 2008 Ozone Area to Attainment

The Environmental Protection Agency (EPA) is proposing to approve a request from the Missouri Department of Natural Resources (MDNR) to redesignate the Missouri portion of the St. Louis-St. Charles-Farmington, MO-IL nonattainment area (``St. Louis area'' or ``area'') to attainment for the 2008 ozone National Ambient Air Quality Standard (NAAQS). MDNR submitted this request on September 12, 2016, with a supplemental submission on February 16, 2018, to include a revised motor vehicle emissions budget. EPA is proposing this action because the request meets the statutory requirements for redesignation under the Clean Air Act (CAA). As part of this action, EPA is also proposing to approve, as a revision to the Missouri State Implementation Plan (SIP), the state's plan for maintaining the 2008 8- hour ozone NAAQS through 2030. Finally, EPA finds adequate and is proposing to approve, as a SIP revision, the State's 2030 volatile organic compound (VOC) and oxides of nitrogen (NOX) Motor Vehicle Emission Budgets (MVEBs) for the Missouri portion of the St. Louis area. EPA addressed the Illinois portion of the St. Louis area in a separate rulemaking action on March 1, 2018. 83 FR 8756.