U.S. Code of Federal Regulations

Regulations most recently checked for updates: Aug 27, 2025

§ 52.1421 - Classification of regions.

The Nebraska 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)
Metropolitan Omaha-Council Bluffs InterstateIIIIIIIIIIII
Lincoln-Beatrice-Fairbury IntrastateIIIIIIIIIIIIII
Metropolitan Sioux City InterstateIIIIIIIIIIIIIII
Nebraska IntrastateIIIIIIIIIIIIIII
[37 FR 10877, May 31, 1972, as amended at 39 FR 16347, May 8, 1974]