Abstract: The present invention provides an apparatus and method for dewatering waste that has been collected in a sewer trap built into a tiltably mounted tank which is divided into two main chambers divided into a number of compartments. A pump is selectly connected to each main chamber to impose a pressurized atmosphere or a partial vacuum. An entry pipe connects to a suction hose outside the tank and to the first main compartment on the inside. Barriers in one main chamber are sealingly connected to the interior tank wall around the top potion and have hinged plates at a second potion. Barriers in the second main chamber are solid and sealed to the interior tank wall. A group of return pipes are adapted to return dewatered waste from the second to the first chamber and the cleaned water to the sewer line. The method taught involves drawing waste from a sewer trap into the first chamber of the tank by vacuum through the entry pipe.