Urban Ozone Regulations
The 1990 Amendments to the federal Clean Air Act require that metropolitan areas exceeding allowed levels of ozone must take corrective action to come into compliance. In the Midwest, the Chicago, Milwaukee, and northwest Indiana areas have been designated among the nation's worst offenders, rating a "severe" classification. The Chicago area, for example, must reduce its ozone-causing emissions by 15% before 1996 and make further reductions of 3% per year through the year 2007. Other Midwest areas with "moderate" cleanup problems include Detroit, Lansing and Muskegon, Michigan; Sheboygan, Wisconsin; and East St. Louis, Illinois.