Grease, oil and sand interceptors shall be provided when, in the opinion of the City Public Works Director, they are necessary for the proper handling of liquid wastes containing constituents and quantities in excess of those amounts as specified in § 6.07 of this chapter, or any flammable wastes, sand or other harmful ingredients, except that such interceptors shall not be required for private living quarters or dwelling units. All interceptors shall be of a type and capacity approved by the Director of Public Works and the City Building Official and shall be located as to be readily and easily accessible for cleaning and inspection. In the maintaining of these interceptors, the owner(s) shall be responsible for the proper removal and disposal by appropriate means of captured material and shall maintain records of the dates, and means of disposal which are subject to review by the City Director of Public Works. Any removal and hauling of the collected materials not performed by owner(s) personnel must be performed by currently licensed waste disposal firms.