Geosynthetic clay liners (GCLs)
Geosynthetics Specifier’s Guide
Bonding clay to geosynthetic materials has created an economical, long-term solution for many applications.
Geosynthetic clay liners (GCLs) are hydraulic barriers made of clay bonded to a single geosynthetic layer or to multiple geosynthetic layers. Because of its low permeability, swelling capacity and relative abundance, natural sodium bentonite is the preferred clay component of GCLs. A wide range of materials, including geotextiles and geomembranes, are used to carry and encapsulate the clay. Also, they provide the product with structural support.
GCLs are used primarily as substitutes for compacted clay liners (CCLs), providing signiﬁcant advantages in cost, ease of installation, and performance. Primary applications include surface impoundment, secondary containment and landﬁlls.
The products have been used commercially for over 10 years. GCL use has grown steadily, and standards have been authored to address swell and ﬂuid-loss index testing, determination of flux, manufacturing, sampling, installation and more.