Definitions for "Non-attainment Area"
Keywords:  naaqs, ambient, pollutant, attain, caaa
A geographical region of the United States that the EPA has designated as not meeting the air quality standards.
A region where air pollution levels persistently exceed acceptable National Ambient Air Quality Standards (NAAQS) for one or more "critical pollutants." The federal government may use the non-attainment classification to indicate the type of air pollution reduction measures that such areas must adopt, and the pollution reduction timeline.
A non-attainment area does not meet National Ambient Air Quality Standards. The Portland-Vancouver region was classified as a non-attainment region for both carbon monoxide and ozone but is currently classified as an air quality maintenance area.