Much progress has been made by geomembrane manufacturers, installers, and third party quality control inspection companies to assure quality materials and construction in geomembrane systems. Comprehensive on-site quality control procedures have also been established for the control of seaming and welding of the geomembrane systems including destructive and nondestructive seam testing for weld quality and leakage. A new trend has emerged which extends the concept , Qf .. quality materials and construction to enable the verification of leak-free systems over the entire lined surface after deployment and installation of the geomembranes. These systems utilize new technology
associated with co-extruded layers made electrically conductive and therefore spark testable over 100% of the surface. Or they incorporate computer graphics and interpretive computer software to analy:ze electrical sensors in a grid precisely locating the position of abnormalities associated with seepage through a damaged liner. These recent developments in quality assurance are explained in this paper in the context of case histories where the materials and techniques have been applied internationally.