40 CFR 52.2421: Classification of regions.

The Virginia plan was evaluated on the basis of the following classifications:

Air quality control region Pollutant

Particulate matter Sulfur oxides Nitrogen dioxide Carbon monoxide Photochemical oxidants (hydrocarbons)

Eastern Tennessee-Southwestern Virginia Interstate I I III III III

Valley of Virginia Intrastate I III III III III

Central Virginia Intrastate I III III III III

Northeastern Virginia Intrastate IA III III III III

State Capital Intrastate I III III III I

Hampton Roads Intrastate I II III III I

National Capital Interstate I I III I I