The Oregon plan was evaluated on the basis of the following classifications:
Air quality control region
| Pollutant
|
---|
Particulate matter
| Sulfur oxides
| Nitrogen dioxide
| Carbon monoxide
| Ozone
|
---|
Portland Interstate | I | IA | III | I | I
|
Southwest Oregon Intrastate | II | III | III | III | III
|
Northwest Oregon Intrastate | III | III | III | III | III
|
Central Oregon Intrastate | II | III | III | III | III
|
Eastern Oregon Intrastate | II | III | III | III | III |
[37 FR 10888, May 31, 1972, as amended at 45 FR 42278, June 24, 1980]