40 CFR § 52.471 - Classification of regions.
§ 52.471 Classification of regions.
The District of Columbia plan was evaluated on the basis of the following classifications:
Air quality control region | Pollutant | ||||
---|---|---|---|---|---|
Particulate matter | Sulfur oxides | Nitrogen dioxide | Carbon monoxide | Ozone | |
National Capital Interstate | I | I | III | I | I |