Abstract: Pumping apparatus for recovering a first liquid, such as a pollutant, floating on a second liquid, such as ground water. A pump immersed in the second liquid, or ground water, operates to produce a cone of depression and discharge the second liquid into a pressure vessel. A variable volume chamber inside the pressure vessel contracts and displaces any contents through an outlet conduit to a product discharge point. When the pump turns off, the variable volume chamber expands and draws product into the chamber to be driven from the chamber during successive pumping operations. Over time periodic pumping operations cause the variable volume chamber to recover the first liquid and move it to a discharge point.