All users of the municipal sewer system shall immediately notify the Director and the POTW of all discharges that could cause problems within the sewer system or POTW, including any slug loadings that would violate any of the specific prohibitions of this subtitle or 40 CFR 403.5(b). All industrial users shall promptly notify the POTW in advance of any substantial change in the volume or character of pollutants in their discharge, including the listed or characteristic hazardous wastes for which the industrial user has submitted initial notification under 40 CFR 403.12(p). City Code, 1976/83, art. 25, §6(a)(7), (8) Ord. 91-775