By Jeryl L. Olson, Eric E. Boyd, and Craig B. Simonsen

In a not unexpected final rule issued today by the U.S. Environmental Protection Agency (EPA) it has listed the “Chicago-Naperville, IL-IN-WI Nonattainment Area” as marginal nonattainment. 77 Fed. Reg. 34221 (June 11, 2012). The rulemaking promulgates the initial air quality designations for twelve counties in Illinois, Indiana, and Wisconsin for the 2008 primary and secondary National Ambient Air Quality Standards (NAAQS) for ozone, in accordance with the requirements of Clean Air Act (CAA) section 107(d). State areas designated as nonattainment are subject to planning and emission reduction requirements in the CAA.