(a) It shall be unlawful to connect downspouts from any roof area, drains from any building foundation, paved areas, yards or open courts, or to discharge liquid wastes from any air conditioning unit or cooling device having a capacity in excess of one ton per hour or one horsepower into any city sanitary sewer.
(b) All discharges prohibited in division (a) above may be discharged into the public gutter or storm drains or open drainage ditches provided such discharge does not create a nuisance. No such liquids may be discharged into any unpaved street or alley.