Approval and Promulgation of Air Quality Implementation Plans; Michigan; Redesignation of the Detroit-Ann Arbor Area to Attainment of the 1997 Annual Standard and the 2006 24-Hour Standard for Fine Particulate Matter

EPA is approving, under the Clean Air Act (CAA), the state of Michigan's request to redesignate the Detroit-Ann Arbor nonattainment area (Livingston, Macomb, Monroe, Oakland, St. Clair, Washtenaw, and Wayne Counties) to attainment for the 1997 annual and 2006 24-hour national ambient air quality standards (NAAQS or standard) for fine particulate matter (PM<INF>2.5</INF>). On July 5, 2011, the Michigan Department of Environmental Quality (MDEQ) submitted a request for EPA to redesignate the Detroit-Ann Arbor Michigan nonattainment area. EPA determined that the Detroit-Ann Arbor area has attained the 1997 annual and 2006 24-hour PM<INF>2.5</INF> standard, and proposed on July 2, 2013, to approve Michigan's request to redesignate the area. EPA is taking final action today on that proposal. EPA also is taking final action in this rulemaking on several related proposals. EPA is approving, as a revision to the Michigan state implementation plan (SIP), the state's plan for maintaining the 1997 annual and 2006 24- hour PM<INF>2.5</INF> NAAQS in the area through 2023. Finally, EPA finds adequate and is approving Michigan's nitrogen oxides (NO<INF>X</INF>) and PM<INF>2.5</INF> Motor Vehicle Emission Budgets (MVEBs) for 2023 for the Detroit-Ann Arbor area. EPA, therefore, grants Michigan's request to redesignate the Detroit-Ann Arbor area to attainment for the 1997 annual and 2006 24-hour PM<INF>2.5</INF> standards.