The maps on the following pages show the nonattainment areas for the various pollutants. Additional information can be found in the Green Book on EPA's website at https://www3.epa.gov/airquality/greenbk/.
On October 26, 2015, EPA adopted a more stringent 8-hour ozone health-based standard of 0.070 ppm. EPA will designate in 2017 both new nonattainment classification ranges and those areas that exceed the 2015 standard. To avoid backsliding, or losing progress toward attaining the 8-hour ozone standard, specific control measures for the previous 1-hour standard may be required to stay in place until an area attains the 8-hour standard.
The map below shows the ozone nonattainment areas designated under the older 2008 8-hour standard of 0.075 ppm. The classification of 8-hour ozone nonattainment areas can range from marginal with an 8-hour design value of up to 0.086 ppm O3, to extreme with an 8-hour design value equal to or above 0.175 ppm O3.
Ozone Nonattainment Areas (January 2015)
Source: U.S. Environmental Protection Agency, Green Book, January 2015, https://www3.epa.gov/airquality/greenbook/map8hr_2008.html
This map shows that a majority of the PM10 nonattainment areas are located in the western half of the United States, where a dryer climate contributes to the formation of greater PM10 pollution.
PM10 Nonattainment Areas (January 2015)
Source: U.S. Environmental Protection Agency, Green Book, January 2015, https://www3.epa.gov/airquality/greenbk/mapPM10.html
This map shows that a majority of the PM2.5 nonattainment areas are located in the western half of the United States and in industrial areas in the east.
Counties Designated Nonattainment for PM2.5
Nonattainment areas are indicated by color. When only a portion of a county is shown in color, it indicates that only that part of the county is within a nonattainment area boundary
Source: U.S. Environmental Protection Agency, Green Book, October 2015, https://www3.epa.gov/airquality/greenbook/mappm25both.html
As of September 2010, all CO areas have been redesignated to maintenance areas. Great progress has been made in reducing CO emissions since 1970.
Los Angeles-South Coast Air basin was redesignated to a NO2 maintenance area in 1998. All other areas of the country presently meet the current NO2 NAAQS, with annual concentrations well below the level of the standard (53 ppb). Annual average ambient NO2 concentrations have decreased by more than 40 percent since 1980.