§52.1121. Classification of regions.
40 C.F.R. § 52.1121
The Massachusetts plan was evaluated on the basis of the following classifications:
Notes, amendments, and revision history
Amendments
[37 FR 10872, May 31, 1972, as amended at 39 FR 16346, May 8, 1974; 45 FR 61303, Sept. 16, 1980; 84 FR 29383, June 24, 2019]
Authority
Authority: 42 U.S.C. 7401 et seq.
Amendments
[40 FR 5521, Feb. 6, 1975]
Amendments
[37 FR 10872, May 31, 1972, as amended at 39 FR 16346, May 8, 1974; 45 FR 61303, Sept. 16, 1980; 84 FR 29383, June 24, 2019]