A method and apparatus to fill, transport and discharge up to 50 or more gallons of waste water while the device remains in the bed of a pickup truck or like vehicle. Innovation is accomplished through the design of the waste water tank which incorporates a main body with a lower side mounted inlet/outlet port, and uniquely designed drain hose management structure comprising a friction grip trough and hose rest, with locking slots. Further innovation is achieved by a method of using the invention in the vehicle thus eliminating lifting and pulling a filled tank.