Table 7-5: Montana Air Quality Nonattainment Areas for Carbon Monoxide (CO)
Tuesday, January 3, 2012
Table 7-5: Montana Air Quality Nonattainment Areas for Carbon Monoxide (CO)
| County | Area | Nonattainment in year | Redesignation to attainment | Classification | Part or whole county | Population (2000) |
|---|---|---|---|---|---|---|
| Cascade | Great Falls | 95 96 97 98 99 00 01 | NA | Not classified | Part | 56,885 |
| Missoula | Missoula | 95 96 97 98 99 00 01 | NA | Moderate <= 12.7ppm | Part | 52,356 |
| Yellowstone | Billings | 95 96 97 98 99 00 01 | NA | Not classified | Part | 91,232 |
KEY: NA = not applicable; ppm = parts per million.
NOTES: Nonattainment areas do not meet the national primary or secondary ambient air quality standard for the specified pollutant. Nonattainment areas are classified based on design values: Serious = an area with a design value of 16.5 ppm and above; Moderate = an area with a design value of 9.1 up to 16.4 ppm.
SOURCE: U.S. Environmental Protection Agency, Green Book, available at http://www.epa.gov/oar/oaqps/greenbk/anay.html as of Apr. 20, 2002.