"This map shows the boundaries of the designated Imperial County, CA 2008 8-hour ozone nonattainment area. It includes the boundaries of associated 1997 8-hour ozone nonattainment and/or maintenance areas, as well as any associated MPOs. The map is intended to depict the extent of 2008 8-hour ozone nonattainment in this area, and how the boundaries of the 2008 8-hour area, 1997 8-hour area, and the MPO planning area relate to each other."
Imperial Co, CA 2008 8-hour Ozone Nonattainment Area
Imperial Co, CA 1997 8-hour Ozone Nonattainment Area
Southern California Association of Governments