(a) The South Dakota plan, as submitted, is approved as meeting the requirements of part C, subpart 1 of the CAA, except that it does not apply to sources proposing to construct on Indian reservations;

(b) Regulations for preventing significant deterioration of air quality. The provisions of §52.21 except paragraph (a)(1) are hereby incorporated and made a part of the South Dakota State implementation plan and are applicable to proposed major stationary sources or major modifications to be located on Indian reservations.

[43 FR 26410, June 19, 1978, as amended at 45 FR 52741, Aug. 7, 1980; 59 FR 47261, Sept. 15, 1994; 68 FR 11324, Mar. 10, 2003; 68 FR 74490, Dec. 24, 2003; 72 FR 72621, Dec. 21, 2007]