The Rhode Island plan was evaluated on the basis of the following classifications:
Air quality control region | Pollutant | ||||
---|---|---|---|---|---|
Particulate matter | Sulfur oxides | Nitrogen dioxide | Carbon monoxide | Ozone | |
Metropolitan Providence Interstate | I | I | III | I | I |
[37 FR 10891, May 31, 1972, as amended at 38 FR 34325, Dec. 13, 1973; 39 FR 16347, May 8, 1974; 46 FR 25460, May 7, 1981]