Significance and Use
4.3 The damage to a geomembrane can be detected using electrical leak location systems. Such systems have been used successfully to locate leaks in electrically-insulating geomembranes such as polyethylene, polypropylene, polyvinyl chloride, chlorosulfonated polyethylene and bituminous geomembranes installed in basins, ponds, tanks, ore and waste pads, and landfill cells.
4.4 The principle behind these techniques is to place a voltage across a synthetic geomembrane and then locate areas where electrical current flows through discontinuities in the geomembrane (as shown schematically in Fig. 1). Other electrical leak paths such as prevent pipe penetrations, flange bolts, steel drains, and batten strips on concrete and other extraneous electrical paths should be electrically isolated or insulated to prevent masking of leak signals caused by electrical current flowing through those electrical paths. The only electrical paths should be through leaks in the geomembrane. This electric detection method of locating leaks in geomembranes can be performed on exposed geomembranes, on geomembranes covered with water or on geomembranes covered with an earthen material layer, or both.
1.1 This standard guide is intended to assist individuals or groups in assessing different options available for locating leaks in installed geomembranes using electrical methods. For clarity, this document uses the term leak to mean holes, punctures, tears, knife cuts, seam defects, cracks and similar breaches through an installed geomembrane.
1.2 This guide does not cover systems that are restricted to seam testing only, nor does it cover systems that may detect leaks non-electrically. It does not cover systems that only detect the presence, but not the location of leaks.
1.3 Warning—The electrical methods used for geomembrane leak location could use high voltages, resulting in the potential for electrical shock or electrocution. This hazard might be increased because operations might be conducted in or near water. In particular, a high voltage could exist between the water or earth material and earth ground, or any grounded conductor. These procedures are potentially very dangerous, and can result in personal injury or death. The electrical methods used for geomembrane leak location should be attempted only by qualified and experienced personnel. Appropriate safety measures must be taken to protect the leak location operators as well as other people at the site.