Landfills are categorized by regulations in three types: industrial, municipal, and hazardous. Individual landfills may be further differentiated by the types of waste which they accept.
All landfills are required to be capped, usually occurring at the end of each day. The cap is typically 6-8” of soil. The cap reduces odor and loss due to wind. At the closing of the landfill, a permanent cap consisting of a membrane and more soil is added.
Before the landfilling operation begins, an “impermeable” base is required. This usually consists of two layers of membranes separated by at least 12” of sand. A network of drain pipes is buried in the sand. These pipes transport the wastewater that must be treated.