It is necessary to increase the volume of rubbish bins, and this is the first method to solve the outflow of sewage. The sewage tank is located in the front lower part of the packer, better utilization of packer and the car body between the upper part of the space, but also reduce the vehicle rear suspension, increases the angle of departure, but the sewage tank volume is small, expansion potential is small; there is a the sewage box located in the packer baseplate under, to renounce the use of packer and the car body between the upper part of the space, also increases the vehicle's rear suspension, reducing the angle of departure, sewage tank volume, expansion potential.