Non-attainment are
Non-attainment area
Area that does not meet one or more of the National Ambient Air QualityStandards for the criteria pollutants designated in the Clean Air Act.
In United States environmental law, a nonattainment area is an area considered to have air quality worse than the National Ambient Air Quality Standards as defined in the Clean Air Act Amendments of 1970 (P.L. 91-604, Sec. 109). Nonattainment areas must have and implement a plan to meet the standard, or risk losing some forms of federal financial assistance. An area may be a nonattainment area for one pollutant and an attainment area for others.