All collection of garbage and trash shall be made by or under the direction and supervision of the City. Nothing contained in this article, however, shall be construed to compel the City to collect garbage or trash in City trucks or by City personnel, and Council may contract with any person for the collection, transportation or disposal of garbage and trash. All vehicles used in collecting and transporting garbage and trash shall be constructed so as to prevent any garbage or trash from leaking, spilling or blowing upon the streets and premises in the City. Vehicles of the contracting person shall be kept clean, sanitary and free from odor.