Systems and methods for disposing of blackwater are disclosed. A first vessel contains a screw running through the vessel from a first end to a second end. The screw is surrounded radially by a filter. The first vessel has a blackwater inlet adjacent the first end. An extrusion plate is adjacent the second end of the first vessel. A combustor vessel is configured to receive a solids component from the extrusion plate. A blackwater stream, consisting of a liquid component and the solids component, is passed through the blackwater inlet into the first vessel, is conveyed by the screw from the first end to the second end, and is pressurized against the extrusion plate. The liquid component is thereby forced from the blackwater stream through the filter and the solids component is forced through the extrusion plate into the combustor. The combustor is configured to combust the solids component.