JP2894539B2 - Aquifer pollution investigation device and its investigation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aquifer contamination inspection apparatus and method for easily and quickly investigating the state of contamination of an aquifer, which is a stratum having groundwater.

[0002]

2. Description of the Related Art Conventionally, there has been an incident in which groundwater contamination of trichlorethylene occurred, for example, due to trichlorethylene washing equipment. In addition, this trichlorethylene flowed out to the river through groundwater. In such a case, the state of contamination of groundwater must be quickly and accurately grasped, and pollutants must be collected immediately.

[0003]

SUMMARY OF THE INVENTION The present invention has been made under the above-mentioned circumstances, and has as its object to provide an aquifer pollution investigation device and a survey method capable of simply and quickly investigating a pollution state. Is to do.

[0004]

Means for Solving the Problems To achieve the above object, the invention according to claim 1 comprises a pipe having a conical tip and a driving means for driving the pipe into the ground. Te becomes, before Symbol tube, the water flow means comprising a slit or water passing holes over a predetermined area in the axial direction from the vicinity of the tip is provided, Obisui the water flow means by implanting the tube body in the ground
To reach the layer, the ground water that has flowed into the pipe body through the water passage means, by taking in water bottle inserted into the tube body, research capable of contaminated aquifer with this groundwater It is an aquifer pollution investigation device characterized by comprising.

[0005] In the invention according to claim 1, the tip is conical.
A tube formed in
Water through slits or water holes over a defined area
Means, and driving means for driving the pipe into the ground
Using an aquifer contamination survey device, the pipe body as the driving means
Nde write out more in the ground, it is reached the water flow means aquifer
The groundwater flowing into the pipe via the water flow means is collected by a water sampler inserted into the pipe, the contamination state of the groundwater is investigated, and the pipe is driven further deeply. , Sequentially collecting groundwater at a deeper position in the aquifer and investigating the pollution state of the groundwater collected in the same manner.
Thus , the aquifer contamination survey method is characterized by three-dimensionally grasping the pollution state of the aquifer having groundwater in the underground direction.

Further, the invention according to claim 3 is characterized in that a pipe body is driven into a plurality of positions on the ground surface to grasp the spread of the three-dimensional pollution state of the aquifer. This is a pollution survey method.

[0007]

According to the first aspect of the present invention, the pipe is driven into the ground, and the tip of the pipe reaches the groundwater surface from the surface of the ground through the unsaturated layer. Then, when the portion of the water flow means reaches the saturated layer below the groundwater level, that is, the aquifer, the groundwater flows into the pipe through the water flow means. At this time, the pipe is driven so that the entire water passage means is located in the aquifer, and the position of the water passage means (original position)
Collect only groundwater and investigate the contamination status of the groundwater at that location.

For this reason, if the area where the water passage means is provided is shortened, the degree of contamination at that position can be accurately grasped, but the average degree of contamination at that position cannot be grasped. If the area where the water means is provided is lengthened, the average degree of contamination at the position can be grasped, but the exact degree of contamination at the position cannot be grasped. Therefore, when investigating to a depth of about 10 m, for example , the length of the water passage means consisting of slits
The is preferably about 1 m.

In addition, since the driving means simply drives the pipe, no large-scale equipment is required, and since the driving is performed while connecting the short pipes, the height can be reduced. The external dimensions may be, for example, about 1 m × 1.5 m in height × width in the plane direction and about 2.5 m in height. Therefore, it is possible to easily and quickly drive the pipe even in a narrow passage beside a building or in a building, and to investigate the contamination state of the aquifer.

[0010] On the other hand, in the invention according to claim 2, by driving the pipe deeper, it is possible to sequentially collect groundwater at a deeper position, and to contaminate the aquifer in a three-dimensional direction in the ground. It is possible to conduct an accurate and accurate investigation.

Further, in the invention according to claim 3,
By investigating the contamination status of groundwater at multiple locations viewed from the ground surface, we can grasp the spread of the three-dimensional pollution status,
It is possible to accurately grasp the pollution source and the traveling direction and spread of the pollution.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Note that this example is based on an actual example performed for an incident actually contaminated with trichlorethylene. First, an aquifer contamination inspection device will be described with reference to FIGS. 1, 2, and 3.

As shown in FIG. 1, FIG. 2 and FIG. 3A, this aquifer pollution survey device includes a pipe 1 having a conical tip, and a driving method for driving the pipe 1 into the ground. The pipe 1 is provided with a slit 3a that constitutes a water-passing means 3 having a predetermined length in the axial direction from the vicinity of the distal end thereof, and is inserted into the pipe 1 through the slit 3a. By collecting the inflowing groundwater, the state of contamination of the aquifer B, which is a stratum having the groundwater, is to be investigated.

The tube 1 has an outer diameter of 40 in this embodiment.
For example, a steel pipe 1a of JIS standard GSP-EG-40A of mm is used, and the tip of the steel pipe 1a is closed by a conical cone 4. The cone 4 is formed of a material having a high hardness separate from the steel pipe 1a, and is fixed to the tip of the steel pipe 1a by fixing means such as welding or screws. A plurality of steel pipes 1a having a length of about 2.5 m are used.

A plurality of slits 3a constituting the water passage means 3 are provided in a range from about 500 mm from the tip of the cone 4 to 1000 mm along the axial direction. That is, a plurality of slits 3a having a diameter of about 200 mm are provided around the steel pipe 1a, and a plurality of slits 3a are provided so as to be adjacent to each other in the axial direction.
Has the role of a strainer for inflowing groundwater in the area. Moreover, by appropriately changing the slit width of the slit 3a in accordance with the grain size of the gravel at the place to be investigated, it is possible to suppress and reduce the inflow of sand and the like when the groundwater flows into the pipe 1. In addition, the slit 3 on the tip side
Portions without a are sand deposits. In addition, 1000 mm
May be arranged in the circumferential direction. In addition, as the total length of the slit 3a in the axial direction,
If this is shortened, the degree of contamination at that position can be accurately grasped, but the average degree of contamination at that position cannot be grasped. Although the degree of contamination can be grasped, the exact degree of contamination at that position cannot be grasped. Therefore, when investigating to a depth of about 10 m, the total length of the slits 3a is 1000
It is preferable to set it to about mm (1 m).

As shown in FIG. 3B, the slits 3a constituting the water passage means 3 may have water passage holes 3b arranged in a line in the same manner as the slits 3a described above. 4), the water holes 3c may be arranged in rows at intervals.
In addition, it is needless to say that it is preferable to process the diameters of the water holes 3b and 3c, the form of arrangement, and the interval according to the particle size of the gravel in the stratum similarly to the slit 3a described above.

The driving means 2 includes a diesel engine (not shown), a hoisting drum 5 driven by the diesel engine,
A hammer 6, a tower 7 for hanging the hammer 6, and a knocking head 8 serving as a base of the hammer 6 are provided.
In particular, before knocking the tube 1, the knocking head 8
It is adapted to be fixed to the upper part of the steel pipe 1a. The overall size of the driving means 2 is 1 m × length × width in the plane direction.
1.5 m, height of about 2.5 to 5.5 m,
It is mounted on a small tailor (carriage) 9 so that it can be moved quickly on site. The driving means 2 can be made lower by using a steel pipe 1a shorter than 2.5 m.

When the pipe 1 is driven into the ground in the aquifer pollution survey device configured as described above, first, the steel pipe 1
This is performed by fixing the knocking head 8 on the upper part of a and dropping the hammer 6 freely. Raising the hammer 6 is performed by the diesel engine and the hoisting drum 5. By the hammer 6, the pipe 1 is driven into the unsaturated zone A from the ground surface, and further into the saturated zone below the groundwater table B1, that is, into the aquifer B. The groundwater of the aquifer B, which is close to the surface composed of sandy soil, gravel, cobblestone-sand and the like of alluvial or diluvially hydrological geology, is passed through the slit 3a in this embodiment. The aquifer B is polluted by analyzing the groundwater.

The investigation of the state of contamination using the aquifer contamination inspection device is performed in the following procedure.

(1) Standard size (in this embodiment, 2.5 m
The knocking head 8 is mounted on the upper part of the tube 1 of m), and the tube 1 is inserted into the ground while being hit with the hammer 6.
When working in a place where a height restriction is not required, a pipe 1 of a standard (for example, 5.5 m) that does not require connection is used.
May be used.

(2) When the tip of the pipe 1 almost reaches the groundwater level, a water level gauge (not shown) is lowered into the pipe 1 to check the groundwater level.

(3) While confirming the groundwater level with a water gauge, the pipe 1 is further driven in. When the upper end of the slit 3a reaches the groundwater level, the driving is temporarily stopped.

(4) A water sampler 10 with upper and lower valves (see FIG. 1B) is inserted into the pipe body 1 to collect groundwater.

(5) The groundwater sampled is analyzed on site by a predetermined method using a detector tube or a PID gas chromatograph.

(6) After water sampling, the driving is restarted and another 1 m
Driving (when water is collected every 1 m in aquifer B).

(7) The driving is stopped, and a drainer such as a baler is inserted into the tube 1, the water in the tube 1 is pumped out, and drained to a notch tank or the like.

(8) The above operation (7) is repeated four to five times to completely replace the groundwater flowing in the first time with the groundwater in the second aquifer. In this case, if the head of the groundwater is small, drainage by an electric pump is possible, but it is not advisable to treat and discharge a large amount of contaminated water.

(9) Put the sampler 10 washed with distilled water into the tube 1
Insert water into water to collect water.

(10) The same analysis as in the above (5) is performed.

(10) -1 The above operations (6) to (10) are repeated.

(10) -2 When a predetermined depth (for example, 10 m) is reached, the upper end of the connected steel pipe is protected with a cap,
Remain as a monitoring well.

It is to be noted that, if the number of times of hammering is recorded, it can be used for comparison of the stratum in the same way as the so-called standard penetration test value (N value).

According to the aquifer pollution survey device configured as described above, the device only needs to be about 1 × 1.5 m in height × 2.5 m in width and about 2.5 m in height. 2.5 mx
If there is a space of 2.5m and a height of 2.5m, it is enough to drive the pipe 1 easily and quickly even in narrow passages and buildings inside the building, and immediately investigate the aquifer contamination state. it can.

According to the aquifer contamination survey method,
By driving the pipe, groundwater at the original position at each depth can be sequentially collected, so that the state of contamination of the aquifer B can be three-dimensionally and accurately investigated underground. . In addition, by investigating the state of contamination of groundwater at a plurality of locations viewed from the ground surface, it is possible to grasp the spread of the three-dimensional pollution state, and accurately grasp the pollution source and the direction and spread of the pollution. .

Next, a description will be given of a pollutant collecting method for collecting pollutants based on the result of investigating the contamination state of the soil contaminated with trichlorethylene using the aquifer contamination survey device and the survey method described above. I do.

This contaminant recovery method uses the above-described aquifer pollution survey device and its survey method to determine the pollution source and the direction of the pollution, and then to the pollution source pumping well that pumps up groundwater containing a high concentration of pollutants. In this method, a traveling-end pumping well 22 for preventing the spread of contamination is provided at a traveling end of the pollution to collect contaminants in the ground.

FIG. 4 schematically shows the positions on the ground surface of the pipe 1, the pollution source pumping well 21, and the advancing end pumping well 22. The pollution source pumping well 21 is located at the source of the pollution, so as to be substantially along the flow direction of the groundwater (that is, the traveling direction of the pollution).
Pumping well No.1 21a, Pumping well No.2 21b and Pumping well No.3
1c are provided. In addition, the progressive pumping well 22
The pumping well No. 4 22a, the pumping well No. 5 22b, the pumping well No. 6 22c, and the pumping well No. 7 22d are located along the direction perpendicular to the flow direction of the groundwater at the end of the pollution. It is provided.

FIG. 5 and FIG. 6 show the state of contamination of the aquifer B, which was investigated by the above-described aquifer contamination investigation device and its investigation method. FIG. 5 shows the cross-section along the line VV of FIG. 4, that is, the cross-section along the flow of groundwater through the pollution source, and FIG. 6 shows the cross-section along the line VI-VI of FIG. The cross-section in the direction perpendicular to the direction of groundwater flow through the end of the pollution is shown.

In FIG. 5, it was confirmed that a high-concentration zone of contaminants was formed at a thickness of about 1.5 m from the groundwater level B1 of the unconfined aquifer B in a cross section along the flow direction of the groundwater. . In FIG. 6, the pollution plume has a thickness of 4 m centering about 2 m below the groundwater table B1 in a cross section transverse to the flowing direction of the groundwater,
It was confirmed that a distorted concentric density distribution having a width of 20 m was formed.

Based on such a polluted state, the above-mentioned polluting source pumping well 21 and the traveling end pumping well 22 are arranged as described above. Then, the contaminated groundwater is pumped up from the contaminated source pumping well 21 and the progressive end pumping well 22, and this contaminated groundwater is aerated and discharged to the river. Aeration device is initially were aerated by diffusing pipe is provided temporarily the steel water tank 4 groups 20 m ^3, is switched after about 2 months established the Toshiki aeration device thereto. The offgas from the aeration device was treated with activated carbon.

After the pumping of the contaminated groundwater started, as shown in FIG. 7, the concentration of trichlorethylene in the groundwater sharply dropped, and the concentration of the progressive pumping well 22 was reduced to about 0.03 mg / m after about one and a half months. It was less than 1. River water was not detected one month after the measures were taken.

According to the pollutant recovery method configured as described above, a plurality of pollutants are provided along the flowing direction of the groundwater at the polluting source of the polluting source well 21, so that the groundwater containing a high concentration of trichlorethylene can be efficiently pumped. Can be. Furthermore, since a plurality of traveling-end pumping wells 22 are provided in the traveling end portion of the pollution in a direction substantially perpendicular to the direction in which the groundwater flows, the progress of the contamination by trichlorethylene can be efficiently prevented.

In the above-mentioned recovery of trichlorethylene, the pumping well 21 at the pollution source and the pumping well 22
3 months after the start of pumping, the trichlorethylene in the unsaturated zone A is removed.

That is, in order to remove trichlorethylene in the stratum (unsaturated zone A) from the ground surface to the groundwater table B1, three months after the start of pumping, a large amount of water is injected into the unsaturated zone A to remove the trichlorethylene. The work and the removal work by the vacuum extraction method were performed. The washed-out trichlorethylene is recovered from the pollution source pumping well 21 and the progressive pumping well 22 together with the groundwater. The vacuum extraction was performed at a pressure of 20 Toll and an exhaust amount of 4 m ³ / min.

As a result of such washing and removal by the vacuum extraction method, the concentration of trichlorethylene in the air, which was initially 150 ppm, rapidly decreased to 50 ppm after 50 days. Moreover, there is an advantage that all trichlorethylene (contaminants) from the surface to the unsaturated zone A and the aquifer B can be collected.

The above-mentioned flushing operation by injecting water into the unsaturated zone A and the removal operation by the vacuum extraction method may be carried out simultaneously with the start of pumping by the pollution source pumping well 21 and the progressive pumping well 22. It may be shifted from the pumping start time as described above due to the installation of the water pump.

Further, in each of the above embodiments, the pipe 1 is driven about 10 m, but the depth of the driving depends on the geology but can be 7 m to 13 m. Then, when the water quality is investigated every 1 m up to 10 m, the work is completed in about one day.

In addition to the method of driving the pipe 1 shown in each of the above embodiments, there is also a method of investigating the geology by boring. For this reason, Table 1 shows a comparison between the boring method and the method of the present embodiment. From this table,
It can be seen that the method of this embodiment is excellent in terms of space saving, easy and quick work, and the like.

[0049]

[Table 1]

[0050]

According to the present invention, in the invention according to claim 1, the pipe is driven into the ground, and the tip of the pipe reaches the groundwater surface from the surface of the ground through the unsaturated layer. Then, when the portion of the water flow means reaches the saturated layer below the groundwater level, that is, the aquifer, the groundwater flows into the pipe through the water flow means. At this time, the pipe is driven so that the entire water passage means is located in the aquifer, and groundwater is collected only at the position (original position) of the water passage means, and the state of contamination of the groundwater at that position is investigated.

Therefore, if the arrangement of the water passage means is shortened,
Although it is possible to accurately determine the degree of pollution at that location, it is not possible to investigate the average degree of pollution at that location. Can be grasped, but the degree of contamination at that position cannot be grasped accurately. Therefore, in the case of investigating to a depth of about 10 m, it is preferable to set the length of the water passage means to about 1 m.

Further, since the driving means simply drives the pipe, no large-scale equipment is required. Further, since the driving is performed while connecting the short pipes, the height can be reduced. The external dimensions may be, for example, about 1 m × 1.5 m in height × width in the plane direction and about 2.5 m in height. Therefore, it is possible to easily and quickly drive the pipe even in a narrow passage beside a building or in a building, and to investigate the contamination state of the aquifer.

On the other hand, in the invention according to the second aspect, by driving the pipe deeper, groundwater at a deeper position can be sequentially collected, and the pollution state of the aquifer can be reduced three-dimensionally in the ground. It is possible to conduct an accurate and accurate investigation.

Further, in the invention according to claim 3,
By investigating the state of contamination of groundwater at a plurality of locations as viewed from the ground surface, the spread of the three-dimensional pollution state can be grasped in conjunction with the method of claim 2, and the source and the direction and spread of the pollution can be determined accurately. Can be grasped.

[Brief description of the drawings]

FIG. 1 shows an aquifer contamination inspection device shown as an embodiment of the present invention, in which (a) is a side view, and (b) is a partially cutaway explanatory view showing the essential parts.

FIG. 2 is a side view showing a tube of the aquifer contamination investigation device.

FIGS. 3A, 3B, and 3C are explanatory diagrams showing each embodiment of a water passage unit.

FIG. 4 is a plan view of an aquifer contamination inspection method shown as one embodiment of the present invention.

FIG. 5 is a sectional view taken along the line VV in FIG. 4;

FIG. 6 is a sectional view taken along the line VI-VI in FIG. 4;

FIG. 7 is a diagram showing a result of a pollutant recovery method shown as one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe 2 Driving means 3 Water passing means B Aquifer

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tadayo Yamai 1-9-27 Miyamaidaira, Miyamae-ku, Kawasaki-shi, Kanagawa Prefecture C-913 (72) Inventor Motoaki Suminami 4-7-1-301 (Miyanosato, Atsugi-shi, Kanagawa Prefecture) 72) Inventor Yoshiro Minamibo 222-1 Kozu, Odawara City, Kanagawa Prefecture (58) Field surveyed (Int.Cl. ⁶ , DB name) E21B 49/08

Claims (3)

(57) [Claims] And 1. A tube was formed tip cone made and a hammering means for hammering the tube in the ground, before Symbol tube, a predetermined area in the axial direction from the vicinity of the tip scan over
Providing a water flow means comprising a lit or a water flow hole ;
Into the ground to allow the water flow means to reach the aquifer,
Underground water flowing into the tube body through the water passage means,
By collecting with a water sampler inserted in the pipe body ,
It is configured to be able to investigate the pollution status of the aquifer with this groundwater
Aquifer pollution investigation device, characterized in that it was. 2. A tubular body having a conical tip, and the tubular body.
From the vicinity of the tip to a predetermined area in the axial direction
Alternatively, a water flow means including a water flow hole and the pipe body are driven into the ground.
Using an aquifer pollution survey device equipped with
Nde write out the tube into the ground by the hammering means, said
The water passage means is allowed to reach the aquifer, and the water is
The groundwater that has flowed into the pipe body is collected and inserted into the pipe body.
By collecting the groundwater with a water bowl, investigating the state of contamination of this groundwater, and driving the pipe further deeply, groundwater at a deeper position in the aquifer was sampled sequentially , and the ground was similarly sampled.
A method for investigating aquifer contamination, characterized by three-dimensionally grasping the state of contamination of an aquifer having groundwater by investigating the state of contamination of sewage . 3. A method for investigating aquifer contamination according to claim 2, wherein a pipe body is driven into a plurality of positions on the ground surface to grasp the spread of the three-dimensional contamination state of the aquifer. .