Each truck or vehicle used in the collection of solid waste shall be equipped with either an all metal watertight box or with a box with a metal lining so that there shall be no escape of liquid contents from the box onto the ground or street. All vehicles used for the collection of solid waste shall be kept closed at all times except when stopped to receive solid waste. Any truck, trailer or other vehicle transporting solid waste on the streets of the City shall be covered with a canvas or other effective means to prevent the same from falling or blowing onto the streets of the City. (1997 Code)