WASTE OR IMPACTED SOIL DISPOSED OF IN A LINED LANDFILL, OR WHEN COVERED IN PLACE WITH AN ENGINEERED CAP, MUST BE MANAGED AS THE MATERIALS DEGRADE, LEACH, CONSOLIDATE, AND DEWATER. In some cases, unlined disposal sites may require the installation of leachate collection systems at the toe of the fill area. Passive and active methane gas collection systems, including vacuum blowers, treatment units, and vent wells may also be installed to control and manage off-gas generated by waste.
Most landfill cells involve the construction of leachate management systems, which consist of a network of perforated and solid high-density polyethylene (HDPE) piping and drainage stone. In total, AST has installed over 75,000 feet of welded HDPE piping with pipe sizes ranging from 2 to 12 inches in diameter and HDPE sumps up to 24 inches in diameter.