ASTM D8551-24 PDF

SIGNIFICANCE AND USE 4.1 Geomembranes are used as impermeable barriers to prevent liquids leaking out of landfills, ponds, and other containment facilities. In addition, geomembranes are also used to prevent external liquids leaking into to these types of facilities (for example, floating covers, landfill caps, and roofs of storage tanks). The liquids may contain contaminants that, if released, can cause damage to the environment or damage to the contents where protection is against leakage into the facility. In the case of a landfill cap, leakage increases the amount of leachate that the landfill can produce. Leaking liquids can erode the subgrade, causing further damage. Leakage can result in product loss or otherwise prevent the installation from performing its intended containment purpose. For these reasons, it is desirable that the geomembrane have as little leakage as practical. 4.2 Geomembrane leaks can be caused by poor quality of the subgrade, poor quality of the material placed on the geomembrane, accidents, poor workmanship, manufacturing defects, and carelessness. 4.3 The most significant causes of leaks in geomembranes that are covered with only water are related to construction activities, including pumps and equipment placed on the geomembrane, accidental punctures, punctures caused by traffic over rocks or debris on the geomembrane or in the subgrade, and ruptures caused by settlement during filling. 4.4 The most significant cause of leaks in geomembranes covered with earthen materials is construction damage caused by machinery that occurs while placing the earthen material on the geomembrane. Such damage also can breach additional layers of the lining system such as geosynthetic clay liners. 4.5 As a practical measure, other electrical leak location methods (see Guide D6747) should be used in conjunction with the permanent monitoring system to eliminate leaks in the installed geomembrane(s) as part of facility construction. Such methods must include testing ... SCOPE 1.1 These practices describe standard procedures for using electrical methods to locate leaks in geomembranes covered with liquid, earthen materials, waste, and/or any material deposited on the geomembrane. 1.2 These practices are intended to ensure that permanent leak detection and location systems are effective, which can result in complete containment (no leaks in the geomembrane). 1.3 Not all sites will be easily amenable to this method, but some preparation can be performed in order to enable this method at nearly any site as outlined in Section 6. If ideal testing conditions cannot be achieved (or designed out), the method can still be performed, but any issues with site conditions must be documented. 1.4 Permanent monitoring systems for electrical leak detection and location can be used on geomembranes installed in basins, ponds, tanks, ore and waste pads, landfill cells, landfill caps, and other containment facilities including civil engineering structures. The procedures are applicable for geomembranes made of materials such as polyethylene, polypropylene, polyvinyl chloride, chlorosulfonated polyethylene, bituminous material, and other sufficiently electrically insulating materials. 1.5 Any permanent electrical monitoring system must detect the occurrence of a leak through the geomembrane, and it must last longer than the monitored geomembrane by nature of the concept. Therefore, all buried components and mechanical and electrical connections must be made of material either the same as the geomembrane, in case of sensors situated above geomembrane, or made from a material with a longer lifespan in cases where they are situated under the monitored geomembrane. 1.6 Permanent electrical monitoring systems are comprised of either large mesh pads separated by nominal spaces, or a grid of sensors situated either below the geomembrane or above the geomembrane or in both positions (below and above the ge...