NOTES: Nonattainment areas do not meet the national primary or secondary
ambient air quality standard (NAAQS) for the specified pollutant. Nonattainment
areas are classified based on design values: Extreme = design value of 0.280 parts
per million (ppm) and above; Severe-17 = design value of 0.190 up to 0.280 ppm
and has 17 years to reach attainment; Severe-15 = design value of 0.180 up to
0.190 ppm and has 15 years to reach attainment; Serious = design value of 0.160
up to 0.180 ppm; Moderate = design value of 0.138 up to 0.160 ppm; Marginal =
design value of 0.121 up to 0.138 ppm; Section 185A = an area designated as an
ozone nonattainment area as of the date of enactment of the Clean Air Act Amendments
of 1990 and has not violated the national primary ambient air quality standard
for ozone for the 36-month period commencing on January 1, 1987, and ending on
December 31, 1989.