High-density Polyethylene (HDPE) geomembranes are widely used for liners and sealings in geotechnical engineering. Common applications include lining of ponds, dams and dykes, landfill underliners and cover systems, remediation of contaminated sites, waterproofing for tunnels, and beneath highways. This handbook covers all aspects of the field: basic materials, geomembrane manufacture, textured geomembranes, long-term performance and testing, installation and welding of geomembranes, quality assurance and control, leak detection, standards, recommendations and regulations.