In the waste final disposal field which adopts the duplex waterproof structure which possesses

摘要

PROBLEM TO BE SOLVED: To realize a water leakage detecting method, in a final waste disposal plant, in which the existence of a leakage of water, in an extreme trace amount, permeating through clay and the position of the leakage of water can be detected at an early stage at a time when a liner sheet is damaged in the disposal plant which adopts a double sealing structure by the liner sheet and by clay. ;SOLUTION: Many drainage sheets 10 are laid in a clay layer. Lower end sides in the flowing-down direction of the respective sheets 10 are connected to sheet connecting pipes 11. The respective sheet connecting pipes 11 are extended independently so as to be connected to a tunnel 3 for observation. A gently negative pressure is applied by a vacuum pump to every sheet connecting pipe 11 from the inside of the tunnel 3. Thereby, when discharged water exists, whether permeated water exists in the discharged water is analyzed. When the permeated water is detected, it is estimated that a sheet damage part exists in the upper part of the drainage sheet 10 connected to one sheet connecting pipe 11.;COPYRIGHT: (C)2000,JPO