Clay is used in containment systems for landfill waste deposits to control the water fluxes in and out of the system.
Why is clay used to line the bottom of landfills?
This layer prevents excess precipi- tation from entering the landfill and forming leachate and helps to prevent the escape of landfill gas, thereby reducing odors.
What are compacted clay liners?
Definition of a Compacted Clay Liner A compacted clay liner is a seepage free barrier constructed of a cohesive soil that is compacted to increase its bulk dry density and homogeneity. The purpose is to reduce porosity and decrease soil permeability.
How does geosynthetic clay liner work?
Geosynthetic Clay Liners (GCL's) are composites that combine geotextile outer layers with a core of low-permeability sodium bentonite clay. Bentonite is a natural sealant, which actuates (hydrates) on contact with water. Geosynthetic Clay Liners are used as a replacement for compacted clay liners.
What is the core of geosynthetic clay liner made of?
sodium bentonite clay
How is geosynthetic clay liner made?
Geosynthetic clay liners (GCLs) are manufactured liners consisting of two needle punched geotextile layers encapsulating a layer of sodium bentonite for sealing applications. The product consists of a high quality sodium bentonite powder encapsulated between an upper and lower layer of geotextile.
What do clay liners do?
A clay liner serves as a hydraulic barrier to flow of fluids. Clay liners are used to minimize infiltration of water into buried waste (cover systems) or to control release of leachate from the waste (liner systems). To meet these objectives, clay liners must have low hydraulic con- ductivity over long periods of time.
What is compacted clay liner?
Definition of a Compacted Clay Liner A compacted clay liner is a seepage free barrier constructed of a cohesive soil that is compacted to increase its bulk dry density and homogeneity. Within the earthen manure storage structure, the compacted clay liner is designed to impede seepage of the liquid manure.
What kind of soil is best for lining a landfill?
Loamy or silty soils that are free of large stones and excess gravel are the best cover for a landfill. Clayey soils may be sticky and difficult to spread; sandy soils are subject to wind erosion.
What should a landfill be lined with?
Modern landfills generally require a layer of compacted clay with a minimum required thickness and a maximum allowable hydraulic conductivity, overlaid by a high-density polyethylene geomembrane.
What is geosynthetic clay liner used for?
Function. The engineering function of a GCL is containment as a hydraulic barrier to water, leachate or other liquids and sometimes gases. As such, they are used as replacements for either compacted clay liners or geomembranes, or they are used in a composite manner to augment the more traditional liner materials.