It shall be unlawful for any person to discharge or cause to be discharged, sewage or sewage disposal effluent directly or indirectly into the ground surface, groundwaters, surface waters, storm sewers or abandoned wells, or maintain or operate a sewage disposal system in such a manner that it becomes a nuisance or adversely affects the public health, safety or welfare. (1979 L.M.C., ch. 46, § 8.)