On May 26, 2021, the U.S. Environmental Protection Agency (EPA) published its final decision expanding the boundaries of ozone non-attainment areas for sixteen counties in the states of Wisconsin, Illinois, Indiana and Missouri. The decision specifically relates to the 2015 National Ambient Air Quality Standards (NAAQS) for ozone and affects the following eastern Wisconsin counties: Milwaukee, Ozaukee, Racine, Waukesha, Washington, Sheboygan, Manitowoc and Door. These newly designated areas will be subject to more stringent Clean Air Act requirements that could limit opportunities for economic growth and development.

EPA initially made these designations in 3 rounds with the Wisconsin County designations promulgated on April 30, 2018. Multiple petitioners challenged these original designations which were consolidated into a single case, Clean Wisconsin v. EPA. In that case, the Court of Appeals for the D.C. Circuit held that EPA had failed to justify its narrow view of which areas should be included in nonattainment designations. As a result, the court remanded the designations back to EPA for further analysis and explanation. You can read more about the 2020 decision by visiting our publication here.

In response to the D.C. Circuit Court’s remand, EPA has reevaluated the attainment designations for eight Wisconsin counties by applying a five factor analysis recommended in EPA’s ozone designations guidance, specifically:

  1. Air Quality Data (including the design value calculated for each Federal Reference Method (FRM) or Federal Equivalent Method (FEM) monitor;
  2. Emissions and Emissions-Related Data (including locations of sources, population, amount of emissions, and urban growth patterns);
  3. Meteorology (weather/transport patterns);
  4. Geography/Topography (including mountain ranges or other physical features that may influence the fate and transport of emissions and ozone concentrations); and
  5. Jurisdictional Boundaries (e.g., counties, air districts, existing nonattainment areas, areas of Indian country, Metropolitan Planning Organizations (MPOs)).

Notably, EPA’s recent decision relies upon the facts that were in the record that was compiled for the original April 2018 designations (i.e., EPA primarily used 2014-2016 ozone monitoring data). EPA did not rely on the current air quality data generated in counties (i.e., 2018-2020 data). That is significant for some counites, such as Manitowoc, which have recent data showing they are attaining compliance with the 2015 ozone NAAQS.

EPA’s attainment designation process does not require public comment. Rather, CAA section 107(d)(1) defines the process for air quality designations that involves recommendations by states, territories, and tribes to the EPA and responses from the EPA to those parties, prior to the EPA promulgating final area designations and boundaries. The EPA is not required under CAA section 107(d)(1) to seek public comment during this designation process. Although EPA did “voluntarily” allow for public comment on the original designation decisions in 2018, the EPA will not allow public comment on this revised set of designations.

New Nonattainment Area Designations and Boundaries

Final actions on the remanded Wisconsin counties include:

  • A change in designation from partial county attainment to full county attainment in Milwaukee and Ozaukee counties;
  • A change in designation from full county attainment to partial county attainment in Racine, Waukesha, and Washington counties; and
  • An expansion of the partial county nonattainment in Manitowoc, Kenosha, and Door Counties.

The new boundaries established by these designations can be found here and are depicted in the four maps below taken for the EPA’s Technical support Document: