The Utah plan was evaluated on the basis of the following classifications: ----------------------------------------------------------------------------------------------------------------
Pollutant
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Air quality control region Photochemical
Particulate Sulfur Nitrogen Carbon oxidants
matter oxides dioxide monoxide (hydrocarbons)----------------------------------------------------------------------------------------------------------------Wasatch Front Intrastate............................. I I I I IFour Corners Interstate.............................. IA IA III III IIIUtah Intrastate...................................... III III III III III---------------------------------------------------------------------------------------------------------------- [37 FR 10898, May 31, 1972, as amended at 39 FR 16347, May 8, 1974]