52.171—Classification of regions.

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

Air quality control region	Pollutant
Air quality control region	Particulate matter	Sulfur oxides	Nitrogen dioxide	Carbon monoxide	Ozone
Central Arkansas Intrastate	II	III	III	III	III
Metropolitan Fort Smith Interstate	II	III	III	III	III
Metropolitan Memphis Interstate	I	III	III	III	I
Monroe (Louisiana)-El Dorado (Arkansas) Interstate	II	III	III	III	III
Northeast Arkansas Intrastate	III	III	III	III	III
Northwest Arkansas Intrastate	III	III	III	III	III
Shreveport-Texarkana-Tyler Interstate	II	III	III	III	III

Code of Federal Regulations

[37 FR 10850, May 31, 1972, as amended at 39 FR 16346, May 8, 1974; 45 FR 6571, Jan. 29, 1980]