During the term of any contract for the collection of garbage or trash by a contractor, garbage and trash shall be disposed of by the contract collector at a site designated by the City. The contract collector shall use a lawful and sanitary method for disposing of all refuse. The responsibility for disposal at any site shall be that of the contract collector, and the City shall not assume any responsibility as to the manner and method used by the contract collector. (1976 Code Sec. 9-10)