How Are Landfills Constructed?
Municipal solid waste landfills are designed and constructed to meet specifications to ensure the protection of the environment including our surface waters, groundwater, and air quality. The two most important aspects of landfill design include liner installation and landfill leachate collection/management. Landfills are designed into cells. Cells are individual waste disposal units or mini-landfills that inter-connect by welded liner systems. Liner Installation: The base of each landfill cell is composed of many layers of liner material. The liners are constructed of high density polyethylene (HDPE) plastic. The first layer is composed of an over-lapping geo-synthetic clay layer (GCL). The GCL is composed of the equivalent to bentonite clay and offers the last defense against leakage of leachate to the groundwater. If liquid comes into contact with the GCL it immediately softens and expands to close off any holes, therefore halting any leaks. The middle layer consists of the primary
