Nonattainment Areas and Areas with a History of Air Pollution
When an area does not meet the air quality standard, it may be subject to formal
rule making process which designates it nonattainment. The Clean Air Act Amendments
(CAAA) of 1990 further classify ozone (O3), carbon monoxide (CO), and some particulate
matter less than ten microns in size (PM10) nonattainment areas based on the magnitude
of the area's problem. Nonattainment classifications may be used to specify what
air pollution reduction measures an area must adopt, and when the area must reach
attainment. Region 8 has a number of nonattainment areas for various pollutants.
A listing of the areas appears below:
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