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 WW—Washington (§52.2470 to §52.2499) > 52.2471—Classification of regions.

52.2471—Classification of regions.

The Washington plan was evaluated on the basis of the following classifications:
Air quality control region Pollutant
Particulate matter Sulfur oxides Nitrogen dioxide Carbon monoxide Ozone
Eastern Washington-Northern Idaho Interstate I IA III I III
Northern Washington Intrastate II III III III III
Olympic-Northwest Washington Intrastate II II III III III
Portland Interstate I IA III I I
Puget Sound Intrastate I IA III I I
South Central Washington Intrastate I III III III III

Code of Federal Regulations

[37 FR 10900, May 31, 1972, as amended at 39 FR 16347, May 8, 1974; 45 FR 37836, June 5, 1980]