This polygon shapefile contains nonattainment areas for particulate matter < 10 microns. Nonattainment areas are geographic areas which have not met national ambient air quality standards (NAAQS) for particulate matter air pollution. These standards are part of the Clean Air Act. See Code of Federal Regulations, Section 40 Part 81, for detailed information about Ambient Air Quality Standards. This shapefile can be used to identify boundaries of non-attainment areas in E.P.A. Region 9. Classifications of severity are also included. This layer is presented in the WGS84 coordinate system for web display purposes. Downloadable data are provided in native coordinate system or projection.
Creator:
United States. Environmental Protection Agency. Region IX
Publisher:
United States. Environmental Protection Agency. Region IX