Nonattainment Area - 8 hr Ozone (1997 Standard)

The Nonattainment Area - 8 hr Ozone (1997) dataset was updated on June 30, 2025 by the Environmental Protection Agency (EPA) and is part of the U.S. Department of Transportation (USDOT)/Bureau of Transportation Statistics (BTS) National Transportation Atlas Database (NTAD). This dataset provides detailed information about areas identified in the U.S. where ground-level ozone have not met the National Ambient Air Quality Standards (NAAQS) established in 1997 for ground-level ozone and have been designated "nonattainment areas (NAA)". This dataset also shows the nonattainment areas at the time of the 8-Hour Ozone (1997) National Ambient Air Quality Standards (NAAQS) revocation on April 6, 2015. These data are weekly from an OAQPS internal database. However, that does not necessarily mean the data have changed. For more information about this non-attainment area, please see the website https://www.epa.gov/green-book/green-book-8-hour-ozone-1997-area-information-naaqs-revoked. A data dictionary, or other source of attribute information, is accessible at https://doi.org/10.21949/1529059