Except as provided in 40 CFR 125.30 through 125.32 or § 437.20(b) , any existing point source subject to this subpart must achieve the following effluent limitations attainable by the application of BCT: Limitations for O&G, pH, and TSS are the same as the corresponding limitation specified in § 437.21 .
40 C.F.R. §437.22