The Maine plan was evaluated on the basis of the following classifications: ----------------------------------------------------------------------------------------------------------------
Pollutant
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Air quality control region Particulate Sulfur Nitrogen Carbon
matter oxides dioxide monoxide Ozone----------------------------------------------------------------------------------------------------------------Metropolitan Portland Intrastate.......................... I II III III IIIAndroscoggin Valley Interstate............................ IA IA III III IIIDown East Intrastate...................................... IA IA III III IIIAroostook Intrastate...................................... III III III III IIINorthwest Maine Intrastate................................ III III III III III---------------------------------------------------------------------------------------------------------------- [37 FR 10870, May 31, 1972, as amended at 45 FR 10774, Feb. 19, 1980]