CFR > Title 40 - Protection of Environment > CHAPTER I—ENVIRONMENTAL PROTECTION AGENCY > SUBCHAPTER C—AIR PROGRAMS (Parts 50–99) > PART 52—APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS > SUBPART MM—Oregon (§52.1970 to §52.1988) > 52.1971—Classification of regions.

52.1971—Classification of regions.

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
Code of Federal Regulations 619

Code of Federal Regulations

[37 FR 10888, May 31, 1972, as amended at 45 FR 42278, June 24, 1980]