Section 52.2178 - Significant deterioration of air quality(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