Development of a leakage detection system for waste disposal yards

In case where alternating voltage is applied to disposal yards with leakages in the geomembrane sheet, the current flowing through leakage can be extracted from the total current flowing in disposal yard by the phase sensitive detector, comparing with the phase of applied alternating voltage. When orientations of linear electrodes which are placed parallel and at equal separation above and below the geomembrane are orthogonal, leakage position can be determined by electrical current flowing between selected electrodes above and below the sheet, alternating voltage applied between them. The performance of system is obtained by the experiments as: (1) Except wet condition, 2 cm 2 leakage can be pinpointed and existence of 1 cm 2 leakage can be determined. (2) Smaller separation of electrodes improve the accuracy of the leakage positioning. (3) The buried electrical conductor may not prevent to detect the leakage positions.