Whenever the waste characteristics of sewage being discharged by any person exceed those requirements of § 52.017, or where necessary in the opinion of the approving authority, the person discharging sewage shall construct or cause to be constructed at no expense to the city the preliminary handling or treatment as may be required to:
(A) Reduce the BOD to 250 parts per million by weight, and the suspended solids to 400 parts per million by weight; or
(B) Change the objectionable characteristics or constituents to come within the maximum limits provided for in § 52.017.
(`95 Code, § 4-2-24)