The Minnesota 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)
|
|---|
| Central Minnesota Intrastate | II | III | III | III | III
|
| Southeast Minnesota-La Crosse (Wisconsin) Interstate | II | Ia | III | III | III
|
| Duluth (Minnesota)-Superior (Wisconsin) Interstate | I | II | III | III | III
|
| Metropolitan Fargo-Moorhead Interstate | II | III | III | III | III
|
| Minneapolis-St. Paul Intrastate | I | I | III | I | III
|
| Northwest Minnesota Intrastate | II | III | III | III | III
|
| Southwest Minnesota Intrastate | III | III | III | III | III |