Abstract: A landfill 24 has an impermeable liner 26 at its base and sides, and is capped at 28 by a multi-layer cap. The body of waste material 46 within the landfill 24 will undergo degradation. One byproduct will be leachate. Sediment 37 will develop at the bottom of the landfill 24 in the absence of any intervention. Extraction wells 38 extend from the surface (above the cap 28) down to the bottom of the landfill 24. A pump 54 allows leachate to be drawn from the waste material 46, through the extraction well 38. Leachate is extracted at a rate sufficient to create turbulence within the body of waste material 46. The turbulence serves to entrain sediment in the leachate for extraction of the entrained sediment with the leachate.