Definitions for "Nonattainment"
Any geographic area that has not met the requirements for clean air as set out in the Clean Air Act of 1990.
Failure to meet the NAAQS for a criteria pollutant in a particular AQCR. In 1977, Congress divided all areas of the country into two categories: those that failed to meet NAAQS (i.e., nonattainment areas) and PSD areas. Nonattainment areas are further categorized as "extreme," "severe," "moderate," or "marginal." The more polluted the area, the more stringent the restrictions.
A federal designation conferred by the U.S. EPA that signifies a geographic area in which the level of a certain air pollutant is higher than the level allowed by federal standards. A single area may have acceptable levels of one air pollutant but unacceptable levels of one or more other air pollutants.