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Ground-level Ozone Pollution

Final Determinations of Attainment by the Attainment Date, Extensions of the Attainment Date, and Reclassification of Several Areas Classified as Moderate for the 2008 Ozone Air Quality Standards

EPA is taking final actions for 11 nonattainment areas classified as Moderate for the 2008 ozone National Ambient Air Quality Standards. These areas were required to attain the standards by July 20, 2018. After evaluating air quality monitoring data for the years 2015 - 2017, EPA has:

  • Determined that Baltimore, MD, and Mariposa, CA, attained the standards by the attainment date;
  • Granted a 1-year attainment date extension for the historic Sheboygan County, Wisconsin, moderate nonattainment area, which is now divided into two areas—the Inland Sheboygan County, WI, nonattainment area and the Shoreline Sheboygan County, WI, nonattainment area. The areas must attain the standard no later than July 20, 2019; and
  • Reclassified seven areas in 8 states—CA, CT, IL, IN, NJ, NY, TX and WI— as Serious nonattainment areas because each failed to attain the standards by the attainment date; and none qualify for a 1-year attainment date extension. These areas must attain the standards by July 20, 2021.
A summary fact sheet is available below.
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