Electrical leak location surveys can be a crucial part of the final quality control of geomembrane liner installations. The method has been offered as a commercial service since 1985 and is the only practical test method that can find holes in the liner after protective soil cover is put on the liner. During the past fourteen years the test method has been used on a wide variety of installations worldwide and is becoming a standard test method offered by several testing companies. However, merely specifying an electrical leak location survey as a requirement does not address the key elements needed to obtain a successful and meaningful leak location survey. A performance-based specification based on sound engineering practices is needed to achieve the specified degree of leak detection sensitivity and accuracy. This paper addresses the fundamental concepts of the electrical leak location detection sensitivity and provides information to allow design engineers, owners, and regulators to accurately specify electrical leak location surveys to achieve the desired results. A practical calibration test is described to determine and verify the measurement parameters needed to obtain a given leak detection sensitivity and to validate the various electrical leak location method implementations and field procedures.
The electrical leak location method is a very powerful tool that can be used to locate leaks in geomembrane liners of landfills, ponds, and tanks. The method has several advantages over conventional test methods because the testing is accomplished after final construction, and after the liner is subjected to construction activity. In addition, this is the only effective method to locate leaks under the protective soil cover of a landfill liner. The initial development of the electrical leak location method began in 1981 and the first commercial surveys were performed in 1985. Today more than twenty companies worldwide offer various types of electrical leak location surveys. Therefore, personnel specifying electrical leak location surveys must understand the parameters that affect the leak detection sensitivity and specify measures to verify the proper operation of the field equipment and procedures.
Performance-Based Specification Of Electrical Leak Location Surveys For Geomembrane Liners