The Idaho plan was evaluated on the basis of the following classifications: ----------------------------------------------------------------------------------------------------------------
Pollutants
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Air quality control region Particulate Sulfur
matter oxides Nitrogen dioxide Carbon monoxide Ozone----------------------------------------------------------------------------------------------------------------Eastern Idaho Intrastate........ I............... II.......... III............. III............ III.Eastern Washington Northern I............... II.......... III............. III............ III.
Idaho Interstate (Idaho).Idaho Intrastate................ I............... III......... III............. III............ III.
Metropolitan Boise Intrastate... II.............. III......... III............. I.............. III.---------------------------------------------------------------------------------------------------------------- [37 FR 10861, May 31, 1972, as amended at 45 FR 70261, Oct. 23, 1980; 47 FR 32534, July 28, 1982]