Findings of Failure To Attain and Reclassification of Areas in Illinois, Indiana, Michigan, Ohio, and Wisconsin as Serious for the 2015 Ozone National Ambient Air Quality Standards

The Environmental Protection Agency (EPA) is determining that the Allegan County, MI; Berrien County, MI; Chicago, IL-IN-WI; Cleveland, OH; Milwaukee, WI; Muskegon County, MI; Sheboygan County, WI; and Illinois portion of the St. Louis, MO-IL areas failed to attain the 2015 ozone National Ambient Air Quality Standards (NAAQS) by the applicable attainment date. The effect of failing to attain by the applicable attainment date is that the areas will be reclassified by operation of law to "Serious" nonattainment for the 2015 ozone NAAQS on January 16, 2025, the effective date of this final rule. This action fulfills EPA's obligation under the Clean Air Act (CAA) 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.