The Nebraska plan was evaluated on the basis of the following classifications:
Air quality control region | Pollutant | ||||
Particulate matter | Sulfur oxides | Nitrogen dioxide | Carbon monoxide | Photochemical oxidants (hydrocarbons) | |
Metropolitan Omaha-Council Bluffs Interstate | I | II | III | III | III |
Lincoln-Beatrice-Fairbury Intrastate | II | III | III | III | III |
Metropolitan Sioux City Interstate | III | III | III | III | III |
Nebraska Intrastate | III | III | III | III | III |
40 C.F.R. §52.1421