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 Q—Iowa (§52.820 to §52.834) > 52.821—Classification of regions.

52.821—Classification of regions.

The Iowa plan was evaluated on the basis of the following classification:
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
Metropolitan Sioux Falls Interstate II III III III III
Metropolitan Sioux City Interstate III III III III III
Metropolitan Dubuque Interstate I III III III III
Metropolitan Quad Cities Interstate I III III III III
Burlington-Keokuk Interstate I I III III III
Northwest Iowa Intrastate III III III III III
North Central Iowa Intrastate IA III III III III
Northeast Iowa Intrastate I III III III III
Southwest Iowa Intrastate III III III III III
South Central Iowa Intrastate I III III III I
Southeast Iowa Intrastate III III III III III

Code of Federal Regulations

[37 FR 10865, May 31, 1972, as amended at 39 FR 16346, May 8, 1974]