The city may levy a surcharge, in addition to the normal sewer use charge, on those discharging to the public sewer any pollutant which is established by the superintendent to be a toxic substance in excess of the limits established by the superintendent for such materials. Any surcharge so levied shall be computed by the superintendent commensurate with the additional costs of sewage treatment, including management of effluent and sludge disposal, which may be incurred by the city as a result of the toxic substance. [Ord. 374 § 2, 1982; Code 1975 § 3-3.0515.]