52.1521—Classification of regions.
The New Hampshire plan was evaluated on the basis of the following classifications:
| Air quality control region | Pollutant | ||||
|---|---|---|---|---|---|
| Particulate matter | Sulfur oxides | Nitrogen dioxide | Carbon monoxide | Ozone | |
| Androscoggin Valley Interstate | IA | IA | III | III | III |
| Central New Hampshire Intrastate | III | III | III | III | III |
| Merrimack Valley-Southern New Hampshire Interstate | I | I | III | III | III |