40 C.F.R. § 52.1771
Classification of regions.
Cite as 40 C.F.R. § 52.1771 (2026)
The North Carolina 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) Western Mountain Intrastate I III III III III Eastern Mountain Intrastate I III III III III Metropolitan Charlotte Interstate I II III III I Northern Piedmont Intrastate I III III III III Eastern Piedmont Intrastate I III III III III Northern Coastal Intrastate I III III III III Southern Coastal Intrastate II III III III III Sandhills Intrastate II III III III III [37 FR 10884, May 31, 1972]