The sanitary sewer system of the city is designed to carry off all liquid house wastes and it is unlawful for any person, firm or corporation to hereafter connect or cause to be connected any stormwater sewer with any such sanitary sewer or any part thereof, or to connect any such sanitary sewer with any stormwater sewer, or any part thereof, or to lead, conduct or carry or cause, suffer or permit to be held, conducted or carried, any such stormwater or surface drainage into or through any such sanitary sewer or any sanitary sewage into or through any stormwater sewer or to connect or cause to be connected in whole or in part, any such sanitary sewer or stormwater sewer. (Prior code § 38-3-18)