Abstract: A particular vacuum tank construction is provided for a vacuum toilet assembly which mounts a vacuum pump, has great versatility and accessibility, and ensures optimized washing effect of water and waste into the vacuum tank. A tank inlet is located at the opposite end of the tank from a sump formed in the tank bottom, and an inlet fitting at the inlet is rotatable at least about 180.degree. about a vertical axis. Connected to a tank outlet is a dip tube assembly including a substantially rigid dip tube which has an oval shaped end termination opening which is above, but spaced from, the sump and positioned so that objects of a size that would harm the vacuum pump connected to the tank outlet cannot enter the dip tube. The tank is of plastic having a nominal wall thickness of about 5/16th inch, and no flat surface area is greater than about 80 square inches. The inlet is connected to a vacuum toilet, and the vacuum pump outlet is connected to a waste (holding) tank.