Four Republican members of Congress, including gubernatorial frontrunner Tom Tiffany, have introduced a bill that would exempt vehicles in southeast Wisconsin from federally mandated emissions testing. 

The bill was introduced by U.S. Rep. Bryan Steil (R-Janesville) and co-sponsored by Reps. Glenn Grothman, Scott Fitzgerald and Tiffany. Tiffany, the only member whose district does not include the affected area of Milwaukee, Kenosha, Ozaukee, Racine, Sheboygan, Washington and Waukesha counties, also brought the issue up on the campaign trail late last month. 

Seven Wisconsin counties, including Milwaukee, are designated ozone nonattainment areas by the EPA under the Clean Air Act, which subjects vehicle owners in the area to additional regulations such as biennial emissions testing. Federal law allows a state to apply for the waiver if it can prove air pollution originates from out-of-state. 

The bill authors point to a Department of Natural Resources report that showed 10% of the ozone measured in the area comes from Wisconsin while more than a third of it comes across Lake Michigan from Illinois and Indiana. 

“Because of outdated federal rules, hundreds of thousands of Wisconsin drivers in seven counties are forced to complete emissions tests every two years just to renew their registration,” Tiffany said in a statement. “Wisconsin families should not be punished with costly and time-consuming mandates because of pollution drifting in from Illinois and Indiana.”

Studies have shown the highest sources of ozone in the region come from the urban centers of Chicago and Milwaukee.