I made a 55 gal. waste tank out of a plastic soap drum. I modified to lay in back of truck sideways. I made a cradle to hold in place and fill and dump without removing from back of truck. On the lower hole installed same valve as on the camper and run sewer hose long enough to reach sewer at dump station and fill it at rv with macerator pump and long hse going to top bung with a valve . On top put a 3/4" valve to allow air to escape when filling and flush with water hose when finished http://i255.photobucket.com/albums/hh134/malojeer/TransportTank002.jpg?1425860916900