Grease, oil and sand traps shall be provided when, in the opinion of the governing body of the city, they are necessary for the proper handling of liquid wastes containing grease in excessive amounts, or any flammable wastes, sand or other harmful ingredients; except, that such traps shall not be required for private living quarters or dwelling units. All traps shall be of a type and capacity approved by the governing body of the city, and shall be located as to be readily and easily accessible for cleaning and inspection. Grease and oil traps shall be installed in all new filling stations, garages, restaurants and other new facilities wherein heavy discharge of grease and oil is to be expected. (Prior code § 4-3-47 (9))