(a) Except as provided in Secs. 125.30 through 125.32, and subject to the provisions of paragraph (b) of this section, any existing point source subject to this subpart shall achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best practicable control technology currently available (BPT): there shall be no discharge of process waste water pollutants into navigable waters.
(b) The limitations specified in paragraph (a) of this section shall be applied on a net basis if the discharge is in compliance with Sec. 125.28 of this chapter ``the source of the applicant's water supply is the same body of water into which the discharge is made * * * ''. [40 FR 48657, Oct. 16, 1975, as amended at 60 FR 33968, June 29, 1995; 60 FR 35796, July 11, 1995]