A field-proven electrical technique, developed at Southwest Research Institute, San Antonio, Texas, is commercially available to detect and locate leaks in geomembrane liners. The electrical technique is used to inspect 100% of the geomembrane material that is covered by a conducting liquid. A voltage applied across the liner produces a uniform electrical potential distribution in the liquid or soil above the liner when no leaks are present in the geomembrane. If leaks are present, they are detected and located by searching for localized anomalies in the potential distribution caused by current flowing through the leak in the geomembrane liner. Sixty-one new or in-service geomembrane-lined waste storage facilities were investigated using the electrical leak location method. An average of 3.2 leaks per 10,000 ft2 were located with a range of 0.3 to 5 leaks per 10,000 ft2 of liner surveyed. Many leaks were located in new installations that had been tested using conventional inspection tests.
Detection and Location of Leaks in Geomembrane Liners Using an Electrical Method: Case Histories