The Clean Air Act and Amendments of 1990 define a "nonattainment area" as a locality where air pollution levels persistently exceed National Ambient Air Quality Standards. Designating an area nonattainment is a formal rulemaking process and EPA normally takes this action only after air quality standards have been exceeded for several consecutive years. This is a simplified listing of nonattainment areas derived from Title 40, as published in the Federal Register. |
