EPA Designates Much of Southeastern Wisconsin as Nonattainment for 2015 Ozone Standards

In November 2017, the U.S. Environmental Protection Agency (EPA) designated most of the country as either attainment/nonattainment under the 2015 National Ambient Air Quality Standards for ozone. Nonattainment areas are those that do not meet (or contribute to ambient air quality in a nearby area that does not meet) the national primary or secondary ambient air quality standards, which were changed to 0.70 parts per billion (ppb) from 0.75 ppb for ozone. Portions of eastern Wisconsin along Lake Michigan were not included in EPA’s original ozone designation.

On Dec. 20, 2017, EPA sent a letter to the state of Wisconsin which included a technical support document, explaining its rationale for designating large portions of eastern Wisconsin as nonattainment.

In reaching its decision, EPA rejected the state of Wisconsin’s recommendation that all of Wisconsin be designated as attainment. Instead, EPA designated all of Milwaukee, Ozaukee, Racine, Waukesha, and Washington counties as nonattainment.

EPA also designated the portion of Sheboygan County that is closest to Lake Michigan as nonattainment, but designated the rest of the county as attainment. In addition, EPA designated portions of Door County and Manitowoc County. EPA also included a portion of Kenosha County as nonattainment.

If EPA’s nonattainment designations are finalized, businesses in southeastern Wisconsin will be especially impacted.  For example, it will lead to increased costs to industry, potential permitting delays, and restrictions on expansion. Nonattainment designation also increases transportation costs due to special fuel requirements.