40 CFR § 52.2621
Classification of regions
June 9, 2020
The Wyoming plan was evaluated on the basis of the following classifications:
Open Table
Air quality control region | Pollutant | ||||
---|---|---|---|---|---|
Particulate matter | Sulfur oxides | Nitrogen dioxide | Carbon monoxide | Photochemical oxidants (hydrocarbons) | |
Cheyenne Intrastate | II | III | III | III | III |
Casper Intrastate | II | III | III | III | III |
Wyoming Intrastate | III | III | III | III | III |
[37 FR 10904, May 31, 1972]