Part 81 — Designation of Areas for Air Quality Planning Purposes
- Subpt. A Meaning of Terms §81.1
- Subpt. B Designation of Air Quality Control Regions §§81.11 to 81.276
- Subpt. C Section 107 Attainment Status Designations §§81.300 to 81.356
- Subpt. D Identification of Mandatory Class I Federal Areas Where Visibility Is an Important Value §§81.400 to 81.437
- Subpt. E Identification of Interstate Transport Regions §§81.455 to 81.457