A reduced pressure dressing for applying reduced pressure treatment to a tissue site includes an interface layer adapted to be positioned at the tissue site. An absorbent layer is in fluid communication with the interface layer to absorb liquid from at least one of the interface layer and the tissue site. A non-motor-driven pump is in fluid communication with the absorbent layer to deliver a reduced pressure to the tissue site. A cover is positioned over the non-motor-driven pump, the absorbent layer, and the interface layer to maintain the reduced pressure at the tissue site, and a liquid-air separator is positioned between the absorbent layer and the non-motor-driven pump to inhibit liquid from entering the non-motor-driven pump.