New York State has moved aggressively to promulgate and enforce regulations requiring landfill managers and operators to use the new "doubled liner" system to reduce the potential for dispersion of toxic wastes into groundwater and soil (Phaneuf & Vana, 2000). However, older landfills, including those at Port Washington, New York, and Staten Island's Fresh Kills, either lack the double liner or (in both cases) have a double liner installed in small portions of the entire landfill mass. A search of the literature on New York State landfills failed to reveal any in-depth information about newer landfills constructed with the double liner, though some data regarding double liner sectors at Port Washington and Fresh Kills can be employed herein to describe the ways in which such liners function to inhibit off-flow of toxic and other undesirable materials generated by landfills.
Double-lined landfills are described by Zero Waste America (2001) as landfills that have one or more layers of lining material, which may consist of clay or a flexible synthetic membrane, or a combination of both. The liner effectively creates a virtual bathtub in the ground. In a double-lined landfill, if the bottom liner fails, wastes mill migrate into the environment via groundwater or soil. For this reason, most environmentalists and the Environmental Protection Agency (EPA) recommend and in some instances require double lining, with one of three types of liners: clay, plastic, and composite.
Zero Waste America (2001) identified problems with each type of liner, as follows:
. Clay liners often fracture and crack because of
a mechanism called diffusion which moves organic
chemicals (e.g., benzene) through a three-foot thick clay landfill liner over the course of five years.
. Plastic liners, the best of which are made of high
density polyethylene (HOPE), can be degraded by a
number of household chemicals, causing the liner to l...