§ 437.40 Applicability.

(a) Except as provided in § 437.1(b), (c), or (d) or in paragraph (b) of this section, facilities that treat wastes subject to more than one of the previous subparts must comply with either provisions of this subpart or the applicable provisions of subpart A, B, or C. The provisions of this subpart are applicable to that portion of wastewater discharges from a centralized waste treatment facility that results from mixing any combination of treated or untreated waste otherwise subject to subpart A, subpart B, or subpart C of this part only if a facility requests the permit writer or control authority to develop subpart D limitations (or standards) and establishes that it provides equivalent treatment as defined in § 437.2(h).