Design & Construction
Each section, or cell, of a Granger landfill takes about a year to construct. This is due to the required excavation, construction of a complex liner system for protection of groundwater, and placement of a piping infrastructure used to collect landfill gas for energy and to protect air quality.
The liner contains layers of different materials to keep trash and leachate (liquid within the trash) in the landfill. The materials include 10 feet of clay, a geocomposite material made from bentonite (a type of clay), a 60 mil flexible membrane (plastic) liner, geotextile (a material similar to felt), sand and tire chips.
Also contained within the layers are numerous perforated, high density polyethylene (HDPE) pipes used to collect landfill gas, along with similar pipes to collect leachate (the liquid component of trash) for treatment.