Before any matter of any nature may be discharged into the sewer system, which discharge might reasonably be considered a violation of this chapter, the controlling characteristic of such matter shall be determined to the satisfaction of the public works director. The responsibility of initiating such determinations, of any costs involved, and of submitting the results of the determinations to the public works director for the director’s approval lies solely with the party or parties desiring to discharge the matter into the sewer system. The fact that any matter has been discharged into the sewer system prior to the passage of the ordinance codified in this chapter or subsequent thereto but without any objection from the city does not constitute a valid right to so discharge such matter. (Ord. 1506-88 § 18, 1988.)