Classification of regions.

The California plan was evaluated on the basis of the following classifications: Table 1 to § 52.221 Air quality control region Pollutant Particulate matter Sulfur oxides Nitrogen dioxide Carbon monoxide Photochemical oxidants (hydrocarbons) Great Basin Valley Intrastate I III III III III Lake County Intrastate II III III III I Lake Tahoe Intrastate II III III I III Metropolitan Los Angeles Intrastate I III III I I Mountain Counties Intrastate II III III I I North Central Coast Intrastate II III III III I North Coast Intrastate II III III III III Northeast Plateau Intrastate III III III III III Sacramento Valley Intrastate II III III I I San Diego Intrastate II III III I I San Francisco Bay Area Intrastate II III III I I San Joaquin Valley Intrastate II III III I I South Central Coast Intrastate III III III III I Southeast Desert Intrastate I III III III I [86 FR 16537, Mar. 30, 2021]