40 C.F.R. § 52.1421 — Classification of regions.
§ 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 Interstate I II III III III Lincoln-Beatrice-Fairbury Intrastate II III III III III Metropolitan Sioux City Interstate III III III III III Nebraska Intrastate III III III III III [37 FR 10877, May 31, 1972, as amended at 39 FR 16347, May 8, 1974]