No statement contained in this chapter shall be construed as preventing any special agreement between the city and any industrial concern whereby an industrial waste of unusual strength or character may be accepted to the system by the city, subject to payment therefor by the industrial concern. (Ord. 5852 § 1, 2004; Ord. 5212 § 1 (Exh. I), 1999; Ord. 4241 § 2, 1987.)