Abstract: A low volume high-pressure toilet. When the user sits on the toilet seat, a hydraulic piston pressurizes the water tank, which optimally holds 1.7 liters of water. Water is released at high pressure through the toilet interior rim and a lower waterjet, forcing the wastewater down a waste pipe. To minimize velocity pressures losses that would be caused by a p-trap, the waste is released straight down a pipe. Sewer gases are prevented from traveling back up the pipe by a sealing valve that occludes the cross sectional area of the waste cavity in the bottom of the toilet.