No person or persons or corporation shall connect any source of sanitary sewage with any sanitary sewer, nor shall any opening whatsoever be made or permitted into a sanitary sewer or into any private sewer or drain connecting with the public sewer except for sinks, water closets or baths. All laundries, livery stables, packing houses, restaurants and butcher shops now connected or which may hereafter be connected with any public sewer shall be provided with a grease trap device as approved by the director of public works. (Ord. 1506-88 § 5, 1988.)