JP2002310845A - Water leakage detection system for water impervious sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detection system capable of easily detecting water leakage of a water impervious sheet installed on the bottom face of an industrial waste disposal site without moving and installing an electrode for detection. SOLUTION: This system is provided with a means for detecting a water leakage position by installing parallel array electrode wires respectively crossing perpendicularly the upper and lower layers of the water impervious sheet, by applying a D.C. voltage between them to generate polarization by an electrolyte, and then by turning off the application to the electrodes to measure the depolarization speed and the depolarization amount of the electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for detecting leakage of a seepage control sheet at a final disposal site by a landfill hole for waste, and more particularly to a system for specifying the location of the leakage.

[0002]

2. Description of the Related Art In a landfill for final disposal of landfills, a water-impervious sheet is laid to prevent harmful waste liquid from escaping from the waste. These seepage control sheets are designed to prevent deterioration due to the environment and damage from external forces caused by the introduction of waste. Including
There was a need for early detection and repair of water leaks.

Therefore, various leak detection methods have been studied and implemented. A typical example is disclosed in JP-A-9-15
Japanese Patent Application Publication No. 081 discloses a water leakage detection system including three electrodes A, B, and C in a water-impervious structure constructed of double water-impervious sheets. A signal line is drawn from each of the plurality of movable electrodes A, the surface electrode B disposed between the two impermeable sheets, and the electrode C laid on the ground, and a circuit is formed by connecting the signal lines to a signal converter. It detects that the voltage and current between the electrodes change due to water leakage.

The above-mentioned known method is a method of connecting a power supply between the electrodes, applying a voltage, and detecting that a current flows due to water leakage. The movable current A is supplied from the ground to many points to be measured. There is a problem that it has to be carried and installed to perform detection work, which takes time and effort.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and does not use a method of transporting a movable electrode for detection, but rather provides a group of electrodes before and after a water-impervious sheet. A DC voltage is applied between the electrode groups, and polarization is performed using an electrode reaction polarization phenomenon caused by an electrolyte between the electrodes. Then, the DC voltage is turned OFF, and the potential of the electrode is measured to detect a water leakage position. It is an object of the present invention to provide a water leakage detection system using a phenomenon in which the repolarization speed of returning to the original state becomes higher or the amount of repolarization becomes larger as the metal electrode becomes closer to the original state.

[0006]

In order to solve the above-mentioned problems, the present invention relates to a system for detecting water leakage of a water-impervious sheet, comprising an electrode made of a conductor on an upper part of a water-impervious sheet laid on the bottom of an industrial waste disposal site. , A second electrode group consisting of a plurality of conductor electrodes arranged below the water-impervious sheet so as to intersect the first electrode group, and a first and second electrode group. In a water leakage detection system for a water-blocking sheet, comprising: a power supply for applying a DC voltage between the electrode groups; and a water leakage detection control unit for measuring the depolarization speed or the depolarization amount. Means for short-circuiting for each electrode group, means for canceling any short-circuit of the first or second electrode group after application of a DC voltage, and the depolarization speed or Means for measuring the amount of depolarization, and the short circuit has been opened After measuring the depolarization speed or the depolarization amount for each electrode of the pole group, short-circuiting is again performed for each of the first and second electrode groups, and after inverting and applying the polarity of the DC voltage, the electrode group on the opposite side Is released and the reversing speed or reversing amount of each electrode is measured.

Further, the first and second electrode groups are characterized in that a plurality of electrodes are arranged in parallel at substantially equal intervals.

Further, the first electrode group and the second electrode group are arranged in a direction substantially orthogonal to each other.

Further, each of the electrodes of the first and second electrode groups is made of metal or carbon fiber having excellent corrosion resistance.

[0010] Further, each of the first and second electrode groups is formed by knitting a conductive wire.

Each of the electrodes of the first and second electrode groups uses a conductive wire made of any of copper, aluminum, stainless steel, and carbon fiber, and the conductive wire is formed in a round or band-shaped cross section. There is a feature.

The electrodes of the first and second electrode groups are
It is characterized by being constituted by conductive wires of different materials.

[0013] The first and second electrode groups are characterized in that the electrodes are woven or adhered to a water-impervious sheet or its buffer sheet and fixed.

Further, the water leakage detection control unit includes a system control computer, an electronic control ON / OFF switch connected to the DC power supply and the first and second electrode groups, and an interface circuit from the computer. ON / OF by control signal output through
F and a switch control circuit, and when a switch connected to one of the electrode groups is turned off, the potential of that electrode is measured with reference to the potential of the other electrode group, and the measured value is passed through the interface circuit. And a potential measurement sequence circuit to be input to the computer.

Further, the water leakage detection control section repeats the process from the short-circuiting of the upper and lower layer electrodes to the release of the short-circuit / measurement of the re-polarization potential by reversing the polarity of the DC power supply, and the highest re-polarization speed in the first electrode group. A water leakage position that selects an electrode with a fast or large depolarization amount, selects an electrode with the fastest depolarization speed or a large depolarization amount in the second electrode group, and specifies the vicinity of the intersection point coordinates as a water leakage position. It is characterized by comprising a specifying means.

Further, in a structure in which the water-impervious sheets laid on the bottom surface of the industrial waste disposal site are provided in double or multiple layers, the water-impervious sheets are substantially perpendicular to the upper and lower parts of each of the water-impervious sheets provided in the multilayer. A plurality of electrode groups are arranged, and water leakage is detected by using the upper electrode group of each water-impervious sheet as a first electrode group and the lower electrode group as a second electrode group.

Further, there is provided measurement data transmitting means for transmitting the data measured by the water leakage detection system from a communication line connection section of the computer to a remote computer via a communication line, and the computer stores the measurement data in a database. It is characterized by recording and collectively managing the presence or absence of water leakage.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the configuration of a water leakage detection system 1 for a seepage control sheet of the present invention. FIG. 2 is a diagram showing a detailed configuration of the water-blocking sheet section 10 in the water leakage detection system 1.

In FIG. 1, reference numeral 20 denotes a water leakage detection control unit, which includes a system control computer 50, interface circuits 41 and 42 having D / A and A / D conversion functions, a potential measurement sequence circuit 30, a switch control circuit 23, It comprises a DC power supply 25 and a communication line connection circuit 43. The communication line connection circuit unit 43 communicates with the head office computer 100 via the Internet 90. In this embodiment, the mode in which the DC power supply 25 is provided in the water leakage detection control unit 20 has been described, but it is needless to say that the DC power supply 25 can be provided outside.

The system control computer 50
Is composed of a control unit 40, a ROM and a RAM. The control unit 40 includes upper and lower electrode group short-circuiting means 40a, upper and lower electrode inter-polarization means 40b, and short-circuit release / electrode return potential measuring means 40c. , A water leakage position specifying means 40d and a measurement data transmitting means 40e.

First, the structure of the impermeable sheet section 10 in the system 10 of the present invention will be described below with reference to FIG.

FIG. 2A shows the upper electrode group 11 woven into a nonwoven fabric 13. In this embodiment, the conductors are arranged in parallel at substantially equal intervals as shown in FIG.

FIG. 2 (b) shows the water impermeable sheet 14.
(C) shows n pieces of water-shielding sheets 14 arranged on the opposite side of the upper electrode group 11 (first electrode group) in parallel at substantially equal intervals in a direction orthogonal to the respective electrodes of the upper electrode group 11. The lower electrode group 12 (second electrode group) made of a conductor is woven into a nonwoven fabric 13. Note that the interval between the upper electrode groups 11 does not need to match the interval between the lower electrode groups 12.
Further, the m conductors and the n conductors do not necessarily need to be arranged in parallel at substantially equal intervals, and the upper electrode group 11 and the lower electrode group 12 do not need to be orthogonal to each other.

FIG. 2D is a cross-sectional view showing the basic structure of the impermeable sheet portion 10. The impermeable sheet part 10 is
Lower electrode group 1 woven into non-woven fabric 13 shown in FIG.
2, a water-impervious sheet 14 shown in FIG. 2B and an upper electrode group 11 woven into a nonwoven fabric 13 shown in FIG. 2A. The nonwoven fabric 13 serves as a protective mat for preventing damage from the upper part and damage from the lower ground.

FIG. 3 is a cross-sectional view of an embodiment of the impermeable sheet portion 10a in which the impermeable sheet has a double structure. The surface layer of the industrial waste disposal site has a structure in which a protective coating 2 such as sand is laid down to a predetermined thickness to protect the waterproof sheet from heavy equipment such as a waste transporter and the waste itself. 1
3, the first electrode group 11, the A layer up to the upper waterproof sheet 14, the second electrode group 12, the nonwoven fabric 13, the lower waterproof sheet 1
It is composed of a B layer up to 4a and a C layer up to the third electrode 11a, the nonwoven fabric 13, and the ground (base) 15.

In such a multilayer structure, the water impermeable sheet 1
The intermediate electrode group provided between 4, 14a is shared and used for water leak detection. That is, in the detection of water leakage of the impermeable sheet 14a, water leakage detection is performed using the second electrode group 12 serving as an intermediate electrode and the third electrode group 11a as a first electrode and a second electrode, respectively.

Next, referring to FIG. 1, the impermeable sheet portion 1 shown in FIG.
0 electrode terminal group 11 (11-1, 11-2,.
−m) and 12 (12-1, 12-2, ‥‥, 12-n)
The water leak detection system 1 is connected to the feeders 31 and 32 to specify the water leak position.

Here, reference numeral 20 denotes the configuration of the entire water leakage detection control unit. A system control computer 50, and a DC power supply 25 for applying a voltage between the upper electrode group 11 and the lower electrode group 12.
And the electric wires 31, 32 of the upper and lower electrode groups 11, 12
M and n electronic control ON / Os provided via
Turn ON / O the FF switch groups 21 and 22 and the DC power supply 25
The DC power supply is turned on between the upper and lower electrode groups 11 and 12 by a switch 24 for FF and a control signal output from the computer 50 via the interface circuit 41.
N / OFF and switch groups 21 and 22 ON
And a switch control circuit section 23 for controlling the short-circuit and release of the upper and lower electrode groups 11 and 12 by turning on / off, and the electrode groups 11 and
When one of the electrode group switches 12 (for example, the electrode group switch 21) is turned off, the potential measurement value of each electrode based on the potential of the other electrode group (here, the electrode group 22) is used as an interface circuit. And a potential measurement sequence circuit 30 to be input to the computer 50 through the circuit 42.

The operation of the detection system control computer 50 will be described.

The switches 21 and 22 are turned on by the signal from the upper and lower electrode group short-circuiting means 40a via the switch control circuit 23, and the upper and lower electrode groups are all short-circuited.

Next, the switch 24 of the DC power supply 25 is turned on via the switch control circuit 23 by the signal of the upper and lower electrode interpolarizing means 40b, and the terminal A of the upper electrode group 11 and the terminal B of the lower electrode group 12 are turned on. And a negative voltage side cathode is polarized through the electrolyte between the upper and lower layer electrodes. Note that the DC power supply 25 includes a main switch control terminal 24.

Short circuit release / electrode return potential measuring means 40c
In the state where the cathode on the negative voltage side is polarized, the switch 24 of the DC power supply 25 is turned off via the switch control circuit 23 and all the switches of the electrode group on the cathode side are turned off. Release is performed, and the electrodes of the released electrode group are sequentially scanned through the potential measurement sequence circuit 30 to repeatedly measure the potential at a predetermined cycle with reference to the other electrode group in a short-circuit state. The change per unit time (polarization speed) of the amount of repolarization to return to the original state from the polarized state or the potential at the time of the measurement is measured to measure the difference from the potential in the polarized state (repolarization amount). . The reversing speed or the reversing amount is measured for each electrode, and it is found that there is a leak near the electrode having the slowest reversing speed or the electrode having the largest reversing amount.

The water leakage position specifying means 40d is provided with the short-circuit release / electrode return potential measuring means 40 from the upper and lower layer short-circuit means 40a.
The measurement was repeated twice until c, and the first measurement was performed with the upper electrode group 11 turned off as a whole and the x electrode with the slowest depolarization was selected. Then, the second measurement was performed with the lower electrode group 12 turned off as the whole. Is selected as the water leak position z near the intersection.

FIG. 3 shows a specific embodiment thereof. FIG.
(A) shows the electrode No. of the layer A (first electrode group). And measured values of the reversing potential. It is a measurement result repeated three times every second. From the measurement results, the electrode Nos. It can be seen that there is a leak location near 3.

FIG. 4B shows the electrode No. of the layer B (second electrode group). And measured values of the reversing potential. It is a measurement result repeated three times every second. From the measurement results, the electrode Nos. 5 and N
o. It can be seen that there is a leak position between 6.

As a result, FIG. 4A and FIG.
As shown in FIG. A-3 and B which are 3
Layer electrode no. B-5, electrode No. 5; B that is 6
Judge that there is a water leakage position in the middle of -6. In addition, the electrode interval is 2 m, the applied voltage is 20 V for 15 minutes. In (a), the A layer is connected to the positive pole of the DC power supply (anode), the B layer is connected to the minus pole (cathode), and in (b), the A layer is connected. The cathode and the layer B were used as the anode.

FIG. 5 is a diagram showing a flowchart of the water leakage detection system 1 of the present invention.

Steps S42 and S43 are the upper and lower electrode group short-circuiting means 40a. Step S44 is the upper and lower electrode polarization means 40b. Steps S45 to S47 are the upper layer electrode short-circuit release / electrode return potential measuring means 40c.

The above is the first measurement.
The upper and lower layer electrode short circuit 48 is means 40a which is the start of the second measurement.

Step S49 is the second time between the upper and lower electrode polarization means 40b. Steps S50 to S52 correspond to the second short-circuit release / electrode return potential measuring means 40 for the lower electrode.
c.

In steps S53 and S54, the data is analyzed.
It is mapped as shown in FIG. Here, the water leakage detection is completed (S55), the modem is set from the computer 50, and the measurement data of the detection result is transmitted from the communication line connection unit 43 via the communication line 90 to the computer 10 of the water leakage management company.
0 (S56, S57). (Measurement data transmission means 40e)

If it is determined from the measured data that there is no water leakage, the process is repeated at a predetermined cycle from step S41. If it is determined that there is water leakage, a notification is given to the disposal site manager to take measures against water leakage repair (S58, S59, S60).

In the industrial waste disposal site using the double-structured waterproof sheet shown in FIG. 3, water leakage between the layer A and the layer B was detected by the above-described method, and water leakage up to the layer B was detected. In this case, it is further confirmed whether water is leaking from the layer B to the layer C. At this time, the second electrode group of the B layer is defined as an upper electrode group,
It is confirmed that water leaks to the C layer using the third electrode group of the C layer as the lower electrode group.

In such an industrial waste disposal site having a multi-layer structure, the formation of the C layer, the formation of the B layer, and the formation of the A layer are performed in the order of formation of the ground. For this reason, at the stage of laying the impermeable sheet of each layer, it is desirable to perform quality control such as poor construction mainly on the joint.

In the water leakage detection system of the present invention, since the first electrode and the second electrode are formed of conductive wires made of different materials, if there is a water leak, the water leak can be detected from a potential difference caused by different metals. it can.

That is, by short-circuiting the second electrode and applying a voltage equal to or higher than the natural potential and sequentially measuring the potential of the first electrode group with reference to the second electrode group, water leakage can be detected. . This operation can be easily performed by providing a voltage application device and a tester on site. Even when a defective part is detected, it can be easily repaired and the quality can be ensured because the defective part is being constructed.

The material of the conductors of the upper and lower electrode groups is preferably a metal such as stainless steel or carbon fiber having excellent corrosion resistance.

Further, the shape of each electrode of the upper and lower electrode groups made of the conductor may be a band shape in which a plurality of electrode wires are knitted for each electrode, and the loading platform strength is increased.

Each electrode of the first and second electrode groups uses a conductive wire made of any one of copper, aluminum, stainless steel, and carbon fiber, and the conductive wire is formed in a round or band-shaped cross section. Used.

Each of the upper and lower electrode groups made of the above-mentioned conductors is arranged in a single nonwoven fabric in parallel with the electrode group and is woven or adhered, or is adhered to the nonwoven fabric at predetermined positions with resin. May be.

By providing the computer 100 at a remote place where the water leakage management company is located, it is possible to record the measurement data in a database and perform the integrated management of the presence or absence of water leakage. Therefore, it is possible to monitor the occurrence of water leakage without incurring the cost of arranging a specialist at the site of the industrial waste disposal site.

As is apparent from the above description, the present invention includes the following technical ideas. (1) In a system for detecting the leakage of a seepage control sheet laid on the bottom surface of an industrial waste disposal site, m sheets arranged in parallel at substantially equal intervals on either the upper part or the lower part of the seepage control sheet. A first electrode group made of a conductor, and n pieces of n-electrodes arranged at substantially equal intervals in a direction orthogonal to the first electrode group on a side opposite to the first electrode group with respect to the impermeable sheet. A second electrode group made of a conductor is connected to one end of each of the first and second electrode groups via an electric wire, and a DC voltage is applied between the first electrode group and the second electrode group. And a leak detection control unit for measuring a voltage during the measurement and specifying a leak location is provided, and the leak detection control unit is provided between the system control computer and the first electrode group and the second electrode group. A DC power supply for applying the voltage, and m each provided through each electric wire of the first and second electrode groups. , N electronically controlled ON / OFF switch groups and the DC power supply in a predetermined order between a first electrode group and a second electrode group by a control signal output from the computer via an interface circuit. A switch sequence circuit for turning ON / OFF the
When one of the electrode group switches provided via the wires of these electrodes is turned off, the potential value of the OFF electrode can be measured with reference to the potential of the other electrode group.
And a potential measurement sequence circuit for inputting measurement values from the n and n potential measurement wirings to the computer via an interface circuit, and all the switches to the first and second electrode groups are turned on. Means for short-circuiting the upper and lower electrode groups, and applying the first and second DC voltages in a state where all switches are ON to the upper and lower electrode groups, and the positive electrode on the positive potential side and the negative potential by the electrolyte therebetween. A means for polarizing between upper and lower layer electrodes for polarizing between the negative electrodes on the side, and a short circuit release for turning off all the switches of one of the first and second electrode groups when in a polarized state between the upper and lower layer electrodes. At the same time, the electrodes of the released electrode group are sequentially scanned to measure the potential with reference to the other electrode group in the ON state, and the measurement is repeated in a predetermined synchronization, and the polarization of each electrode is returned to the original state. Back to And a short-circuit release / electrode depolarization potential measuring means for measuring the time variation of the potential of Utosuru depolarization, and identifies a leak position from the delay time difference depolarization.

[0053]

The system for detecting water leakage of a seepage control sheet of the present invention has the following effects.

In the water leakage detection system for a water-impervious sheet according to the present invention, the detection electrodes arranged in parallel in advance are arranged and laid on the upper and lower layers of the water-impervious sheet so that the electrodes are orthogonal to each other. The polarization reversal speed or the amount of repolarization due to is measured for each electrode, and if the electrode with the fastest reversion speed is detected for the upper electrode group and the lower electrode group, the water leakage position is easily determined from the intersection of the electrodes. Can be estimated.

Compared with the conventional method, the detecting operation is easy and the cost is low. That is, there is no need to install a detection movable electrode for identifying a damaged portion in a vast disposal site.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a water leakage detection system of the present invention.

FIG. 2 is a diagram showing a basic structure of a seepage control sheet portion of the present invention.

FIG. 3 is a structural diagram of an embodiment of a double structure of a water impermeable sheet portion of the present invention.

FIG. 4 is a diagram showing measurement data of water leak position detection according to the present invention.

FIG. 5 is a flowchart of the water leakage detection system of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Water leak detection system 2 Protective film of sand etc. 10 Waterproof sheet part 10a Waterproof sheet part (double structure) 11 m upper layer electrode groups woven into a nonwoven fabric and electrode terminal groups thereof (first electrode group) 11a 3 electrode group 12 n lower layer electrode groups woven into a nonwoven fabric and its electrode terminal group (second electrode group) 13 nonwoven fabric (protection sheet) 14 water-blocking sheet 14a water-blocking sheet 15 ground (ground) 20 water leakage detection control Section 21 (21-1, 21-2, ‥‥, 21-m) m electronic control switch groups on the upper layer electrode group side 22 (22-1, 22, 2, ‥‥, 22-n) Lower electrode group N-side electronic control switch group 23 applied switch sequence circuit 24 main switch control terminal of DC power supply 25 DC power supply for application between upper and lower electrodes 30 potential measurement sequence circuit 31 m wires on upper electrode group side 32 lower N wires 40 on the layer electrode group side 40 control unit (CPU) 40a upper and lower layer electrode group short circuit means 40b upper and lower layer electrode polarization means 40c short circuit release / electrode return potential measuring means 40d water leak position specifying means 50 computer for detection system control 41, 42 Interface unit 43 Communication line connection unit including modem 50 System control computer 90 Communication line 100 Computer at headquarters of leak detection management company

Continued on the front page (72) Inventor Yoshimi Okuyama, No. 2, Sanbancho, Chiyoda-ku, Tokyo Tobishima Construction Co., Ltd. (72) Inventor Eiji Hayashi No. 2, Sanbancho, Chiyoda-ku, Tokyo Tobishima Construction Co., Ltd. (72) Inventor Hiroshi Sasaki 2 Tobanjima Construction Co., Ltd. 2 Sanbancho, Chiyoda-ku, Tokyo (72) Inventor Yasuhiro Arakawa 2 Tobanjima Construction Co., Ltd. 2 Sanbancho, Chiyoda-ku, Tokyo (72 ) Inventor Hideki Ueda 1-12-12, Minami Kamata, Ota-ku, Tokyo Inside Japan Anticorrosion Industry Co., Ltd. 2G067 AA09 BB35 CC01 DD27 EE08 4D004 AA50 AB01 BB06 CA44 DA01 DA16

Claims (12)

[Claims] 1. A first electrode group in which a plurality of electrodes made of a conductor are arranged on a water-impervious sheet laid on the bottom of an industrial waste disposal site, and a first electrode is provided on a lower part of the water-impervious sheet. A second electrode composed of a plurality of conductor electrodes arranged so as to cross the group;
A power supply for applying a DC voltage between the first electrode group and the second electrode group, and a water leakage detection control unit for measuring the reversal speed or the amount of repolarization. The detection control unit includes means for short-circuiting for each of the first and second electrode groups, means for canceling the short-circuit of any of the first or second electrode group after application of a DC voltage, and an electrode for which the short-circuit has been released. Means for measuring the depolarization speed or depolarization amount for each electrode of the group, and after measuring the depolarization speed or depolarization amount for each electrode of the electrode group in which the short circuit has been released, the first and second steps are repeated. After short-circuiting for each of the two electrode groups, applying the DC voltage with its polarity reversed,
A water leakage detection system for a seepage control sheet, wherein a short circuit of an electrode group on the opposite side is released and a return speed or a return amount of each electrode is measured. 2. The system according to claim 1, wherein the first and second electrode groups include a plurality of electrodes arranged in parallel at substantially equal intervals. 3. The first electrode group and the second electrode group are arranged in a direction substantially orthogonal to each other.
2. A water leakage detection system for a water impermeable sheet according to 2. 4. The water leakage of a waterproof sheet according to claim 1, wherein each electrode of the first and second electrode groups is made of metal or carbon fiber having excellent corrosion resistance. Detection system. 5. The system according to claim 1, wherein each electrode of the first and second electrode groups is formed by knitting a conductive wire. 6. Each of the first and second electrode groups uses a conductive wire made of any one of copper, aluminum, stainless steel, and carbon fiber, and the conductive wire is formed in a round or band-shaped cross section. The water leakage detection system for a water-impervious sheet according to claim 1, wherein: 7. The system according to claim 1, wherein the electrodes of the first and second electrode groups are made of conductive wires made of different materials. 8. The method according to claim 1, wherein the first and second electrode groups are fixed by weaving or attaching the electrodes to a water-blocking sheet or a buffer sheet thereof. Water leakage detection system for impermeable sheets. 9. The water leak detection control unit includes: a system control computer; an electronic control ON / OFF switch respectively connected to a DC power supply and first and second electrode groups;
A switch control circuit for turning on / off the switches by a control signal output from the computer via an interface circuit; and a switch connected to one of the electrode groups, when a switch connected to the other electrode group is turned off, the potential of the other electrode group is changed to the other electrode group. 9. The system according to claim 1, further comprising: a potential measurement sequence circuit that measures each of the potentials with reference to the potential and inputs the measured value to the computer via an interface circuit. . 10. The water leakage detection control section repeats the steps from the short-circuiting of the upper and lower layer electrodes to the short-circuit release / measurement of the re-polarization potential by reversing the polarity of the DC power supply, and the reversal speed of the first electrode group being the highest. A water leakage position that selects an electrode with a fast or large depolarization amount, selects an electrode with the fastest depolarization speed or a large depolarization amount in the second electrode group, and specifies the vicinity of the intersection point coordinates as a water leakage position. 2. The apparatus according to claim 1, further comprising a specifying unit.
10. A water leakage detection system for a water-impervious sheet according to any one of claims to 9. 11. In a structure in which water-impervious sheets laid on the bottom surface of the industrial waste disposal site are provided in double or multiple layers, the water-impervious sheets are substantially orthogonal to the upper and lower parts of each of the water-impervious sheets provided in the multilayer. A plurality of electrode groups are arranged, and water leakage is detected by using an upper electrode group of each of the waterproof sheets as a first electrode group and a lower electrode group as a second electrode group. A water leak detection system for the impermeable sheet described in the above. 12. A measurement data transmitting means for transmitting data measured by the water leakage detection system from a communication line connection portion of the computer to a remote computer via a communication line, and the computer stores the measurement data in a database. The system according to any one of claims 1 to 11, wherein recording is performed to collectively manage the presence or absence of water leakage.