Sections 301(d)(2) and 302(r), 42 U.S.C. 7601(d)(2) and 7602(r), authorize the Administrator to treat an Indian tribe in the same manner as a State for the Clean Air Act provisions identified in § 49.3 if the Indian tribe meets the following criteria:

(a) The applicant is an Indian tribe recognized by the Secretary of the Interior;

(b) The Indian tribe has a governing body carrying out substantial governmental duties and functions;

(c) The functions to be exercised by the Indian tribe pertain to the management and protection of air resources within the exterior boundaries of the reservation or other areas within the tribe's jurisdiction; and

(d) The Indian tribe is reasonably expected to be capable, in the EPA Regional Administrator's judgment, of carrying out the functions to be exercised in a manner consistent with the terms and purposes of the Clean Air Act and all applicable regulations.