LLSI is an International Company Specializing in Electrical Leak Location Surveys of Geomembrane Liners. Geomembrane Liner Leak Detection for Landfills, and Surface Impoundments. QUALITY CONTROL / QUALITY ASSURANCE ASTM STANDARD D-6747 TESTING Cutting Holes for Testing or Testing for Holes and Cuts? Do you have it backwards? The industry is changing the erroneous rationale of focusing on testing seams that almost never fail in service while ignoring actual holes in the geomembranes. Geomembrane Leak Detection