by the United States government

“ Such treatment shall be authorized only if— (A) the Indian tribe has a governing body carrying out substantial governmental duties and powers; (B) 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 (C) the Indian tribe is reasonably expected to be capable, in the judgment of the Administrator, of carrying out the functions to be exercised in a manner consistent with the terms and purposes of this chapter and all applicable regulations. ”

“ Detail of Environmental Protection Agency personnel to air pollution control agencies Upon the request of an air pollution control agency, personnel of the Environmental Protection Agency may be detailed to such agency for the purpose of carrying out the provisions of this chapter. ”