The Idaho plan was evaluated on the basis of the following classifications:
Air quality control region | Pollutants | ||||
Particulate matter | Sulfur oxides | Nitrogen dioxide | Carbon monoxide | Ozone | |
Eastern Idaho Intrastate | I | II | III | III | III. |
Eastern Washington Northern Idaho Interstate (Idaho) | I | II | III | III | III. |
Idaho Intrastate | I | III | III | III | III. |
Metropolitan Boise Intrastate | II | III | III | I | III. |
40 C.F.R. §52.671