It is unlawful for any person to discharge or cause to be discharged any of the following into any public sewer or into any side sewer discharging into any public sewer: subsoil, foundation, footing, window-well, door-well, yard or basement floor drains; unpolluted industrial process water; roof drains or downspouts from areas exposed to rainfall or other precipitation; or surface or underground water from any source. (Ord. 1634 § 1, 1996).