• HQ Call: +27 (0)12 660 1616
  • Email: info@gast.co.za
  • GAST Liberty Park 96, Achilles Str. Zwavelpoort, Pretoria, South Africa

Geosynthetic Clay Liners (GCL) have become a necessity due to new environmental laws that state that any seepage from landfills must be properly collected and disposed of in order to prevent contamination of the surrounding ground water.


GCLs are woven fabric-like materials, which has the primary function of providing lining for landfills. Since a GCL is a type of geomembrane that incorporates clay, it has a very low hydraulic conductivity which in turn lowers permeability, slowing down the seepage rate of the landfill. GAST makes use of GCLs in the following applications: landfill caps, closures, base seals, environmental protection under roads, railways, airports, dams and dykes, vertical barriers, pond applications, waterproofing and secondary containment. Using GCLs has two main advantages namely its water permeability and shear resistance.