On the compatibility of GCLs to leachates of extreme chemistry

Geosynthetic clay liners (GCLs) are frequently used in lieu of or as an augmentation to compacted clay liners as hydraulic barriers in municipal solid waste containment facilities. GCLs are lately being assessed for use in industrial and mining applications, such as for the temporary storage of process waters and permanent disposal of tailings, but also beneath heap leach pads, where their performance will be subjected to loads, hydraulic heads and leachate chemistries outside the normal conditions found in conventional municipal waste landfills. The paper considers recent and limited research that has assessed the compatibility of GCLs to leachates having extreme chemistry. Extreme chemistry is here defined as strongly alkaline (pH > 12), strongly acidic (pH < 3) and hypersaline (I > 1 M).