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    • Nonattainment Area - Nitrogen Dioxide (NO2 - 1971 Standard)

    Metadata Updated: October 21, 2025

    The Nonattainment Area - Nitrogen Dioxide (NO2-1971) dataset was updated on September 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 the nonattainment area for the Nitrogen Dioxide (1971) National Ambient Air Quality Standards (NAAQS). On September 22, 1998 the only Nitrogen Dioxide (1971) nonattainment area was redesignated to maintenance. 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-nitrogen-dioxide-1971-area-information. A data dictionary, or other source of attribute information, is accessible at https://doi.org/10.21949/1529064

    Access & Use Information

    License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Date October 20, 2025
    Metadata Created Date August 3, 2024
    Metadata Updated Date October 21, 2025
    Reference Date(s) July 1, 2004 (creation), October 18, 2025 (revision)
    Frequency Of Update weekly

    Metadata Source

    Harvested from National Transportation Atlas Database (NTAD) Metadata

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Date October 20, 2025
    Metadata Created Date August 3, 2024
    Metadata Updated Date October 21, 2025
    Reference Date(s) July 1, 2004 (creation), October 18, 2025 (revision)
    Responsible Party Environmental Protection Agency (EPA) (Point of Contact)
    Contact Email
    Guid Nonattainment Area - Nitrogen Dioxide (NO2 - 1971 Standard)
    Access Constraints Access Constraints: unrestricted
    Bbox East Long -116.518310969222
    Bbox North Lat 34.818133491
    Bbox South Lat 32.803119109677
    Bbox West Long -118.944862498
    Coupled Resource
    Frequency Of Update weekly
    Harvest Object Id cd68e31f-d015-47a9-afff-38096e702613
    Harvest Source Id ee45e034-47c1-4a61-a3ec-de75031e6865
    Harvest Source Title National Transportation Atlas Database (NTAD) Metadata
    Licence This NTAD dataset is a work of the United States government as defined in 17 U.S.C. § 101 and as such are not protected by any U.S. copyrights. This work is available for unrestricted public use.
    Lineage
    Metadata Language eng; USA
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": [[[-118.944862498, 32.803119109677], [-116.518310969222, 32.803119109677], [-116.518310969222, 34.818133491], [-118.944862498, 34.818133491], [-118.944862498, 32.803119109677]]]}
    Progress onGoing
    Spatial Data Service Type
    Spatial Reference System 3857
    Spatial Harvester True

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