VTN/W/0015
v
Geological and Mineral Survey of Vietnam
Northern Hydrogeological Engineering Geological
Division
UNICEF Vietnam
CONFIDENTIAL
FOR INTERNAL USE ONLY
unicef
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investigated results for arsenic
groundwater level
in Ha Noi city
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Geological and Mineral Survey of Vietnam - The Northern HEG Division
foreword
Groundwater pollution, specially arsenic pollution are very harmful for health
of human being which are recovered in many countries in the world. In Vietnam the
recent study of the UNICEF and some other organizations in Hanoi area and in some
place of the Red river delta plain showed the signal of the arsenic pollution in
groundwater. The investigated arsenic concetration is higher than standard limitation
for drinking water.
In the plan of investigation for arsenic pollution in groundwater in Hanoi city
and in the Red river delta plain, the UNICEF has planed in two phases. The phase I is
divided into 3 steps:
1. General investigation of the environmental parameters and arsenic in the
Hanoi city and in the Red river delta plain.
2. Based on the obtained results in the first step determine areas which having
higher arsenic content than standard limitation to consider and study
more detail groundwater quality.
3. Based on the obtained results of the second step the groundwater regime,
determine potential arsenic pollution areas and these areas will be
observed continuously.
To implement step by step these above mentioned plan, the UNICEF
collaborated with the Northern Hydrogeological Engineering Geological Division
belonging to the Geological and Mineral Survey of Vietnam to investigate, survey,
sample and analysis the parameters in groundwater and waste water: pH, temperature,
electric conductivity, dissolved oxygen, Eh, alkalinity, ammonia, arsenic, manganese,
iron in 500 points in Hanoi area. The participants are Centre for Environmental
Technology and sustainable development - University for Natural Science- National
University, Analytical and Experimental Centre for Geology - Geological and Mineral
Survey of Vietnam.
After getting investigated results we has made report "Results on investigation
of arsenic pollution in groundwater in Hanoi city". The report is written by Msc. Tong
Ngoc Thanh and other staffs: Msc. Tran Hoang Thien, Nguyen Thi Ha, Nguyen Thanh
Hai, Dinh Thi Ty, Dang Huu Nam.
The report contents the following 6 heads
I.
Hydrogeological conditions and status of ground water exploitation
II.
Implement method and quantity
III.
Creating database
____IV.
_
Evaluation of reliability of_
analytic method
"* Report on investigaed results of arsenic pollution in groundwater in Hanoi city "=>
__ _
Geological and Mineral Survey of Vietnam - The Northern HEG Division
________
V.
Evaluation of ground water pollution
VI. Some oponions on reasons of groundwater pollution
VII. Some proposes for the next study
The 8 GIS maps are enclosed.
The authors express their thank to the UNICEF, leader of the Geological and
Mineral Survey of Vietnam , the Northern Hydrogeological Engineering Geological
Division, Analytical and Experimental Centre for Geology - Geological and Mineral
Survey of Vietnam, Centre for Environmental Technology and sustainable
development - University for Natural Science- National University, local authorities for
available help.
^4
Report on investigaed results of arsenic pollution in groundwater in Hanoi city ^>
'<?\
> ) Geological and Mineral Survey of Vietnam - The Northern HEG Division____________
I. Geological- hydrogeological condition and status of groundwater exploitation
LI. Geological- hydrogeological condition
The study area is in the center of the Bacbo Plain, which are composed by
unconsolidated Quaternary sediments overlying on the consolidated rocks such as
Neogen, Mezozoi, Proterozoi. The unconsolidated Quaternary sediments have structure
of vertical rhyme intercalated with coarse and fine grain layers creating alternate
aquifers with weak permeable layers.
The characters of the main aquifers and weak permeable layers are described:
1.1.1. Holocene weak permeable sediments
These sediments are in the Thai Binh formation (aQjv^bj), Haihung formation
(abQp/^hh) cropping out in the ground surface. They distribute widely in the south of
Red river and Duong river areas. The thickness is 2-8m. The compositions are clay, silt
clay. The Haihung sediments contain vegetable remains alternated with peat and mudpeat layers. There are mud, peat layers in the west strip and in the south of Hanoi area.
These sediments are weak permeable.
1.1.2. Holocene inter-granular aquifer (qh)
This aquifer distributes rather widely in the study area except in north area - Soc
Son- Dong Anh district. The aquifer is cropped out in the strips along the Red river and
Duong river, the rest ones are covered by the above mentioned weaky permeable
sediemnts. The compositions are sand from fine to medium, sandy. This is unconfined
aquifer, in some place it is weak confined.
The permeability is from medium to high. The test pumping rate is from 2,08
to 30 1/s. The potential water bearing is from medium to high. The water circulating in
the aquifer is fresh ( TDS < 0.5 g/1), and is bicarbonate chloride - calcium, sodium of
type, the iron, manganese and ammonia (NH/) content is high.
The groundwater regime in this aquifer in the south of Hanoi area is in natural
regime condition, only is affected in the south of Hanoi area by groundwater
exploitation in lower aquifer. The water level (mean above sea level- MASL) in the
Phapvan - Tuong Mai -Thanh Nhan area is deep from -2.83m to -6.89m, and is -9.75m
in the Tuong Mai well-field.
In this aquifer the water is abstracted by the dug wells, UNICEF well for domestic
demand.
1.1.3. Pleistocene weak permeable sediments
These sediments are in the Vinh Phuc formation (Qmvp) distributing widely in the
study area. They are cropped out in the north of Red river and Duong river, in the south
area they are covered except Mai Dich- Cau Giay area. In the Red river strip this
__
"' Report on investigaed results of arsenic pollution in groundwater in Hanoi city "=>
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3
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* /Geological and Mineral Survey of Vietnam - The Northern HEG Division____________
sediments are absent due to the erosion. The compositions are clay, clayey with motley
colour. There is mud, peat layer or vegetable remains in some place. The thickness is
4-20m. They are weak permeable.
1.1.4. Pleistocene inter-granular aquifer (qp)
This aquifer is in the sediments of the Vinh Phuc formation (aQm2vp), Hanoi
formation (aQn.fflhn; apQu.nihn) distributing widely in the study area except north
mountain area (Socson). The composition are in two layers: the upper layer composed
medium- coarse sand with yellow colour mixed with gravel of the Vinh Phuc
formation (aQm2vp), the lower layer is cobble, pebble mixed with sand of Hanoi
formation. There is clay, clayey layer between these two layers but not continuously.
The aquifer's top is 12m - 40m and aquifer' bed is 60-70m of depth. The thickness is
20-50m. The permeability is high, the test pumping rate is 10-501/s.
The TDS is small 0.2-0.5g/l, and is bicarbonate, chloride - calcium, magnesium of
type. The water is neuter, soft but the iron, manganese and some heavy metal content is
high, the ammonia content is high (10-50mg/l). They need to be treated before using.
This aquifer is abstracted strongly for domestic. The Clean water Business
Company and other organizations have exploitation wells in this aquifer. Due to the
strong exploitation the cone of depression is created in the south of Hanoi area (figure
1) with 247.5 km2 area (May 2000) creating flow direction from river and its vicinity
areas recharged to groundwater.
The groundwater regime is affected in the south of Hanoi. The water level is
deep depending on to the rate and schedule of pump of the production wells. The water
level ( MASL) inthe well-fields is very deep: -31.05m in the Hadinh wellfield and is 20.38m in Phap Van, -23.84m in Tirotig Mai, -15.37m in Luomg Yen wellfields.
^
•'* Report on investigated results of arsenic pollution in groundwater in Hanoi city *$
?> \I Geological and Mineral Survey of Vietnam - The Northern HEG
Division
Figure 1: Map of eone of depression in the south of Hanoi area May- 2000
dKheChphdjh1 th£p
cheu£n
Di0n Ifch phdu <Om : 247.5 Km2
P.41
Di0n tfch phdu <-8m : 88.7 Km2
DiCn tfch phdu <-I4m : 22.23 Km2
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L6 khoan quan trac
| Di/Cmg ihuy dang ap
1.2. Status of groundwater exploitation
The French has drilled first production well since last century for domestic.
Nowadays due to the urbanization the water demand is increasing. Groundwater are
abstracted with huge amount for domestic, industrial demand. There are under three
types of exploitation:
• Public exploitation wells.
These wells are managed by the Hanoi Clean Water Business Company. They are in
large diameter, screened in qp aquifer . There are 8 big wellfields and 13 small
wellfield approximate to 400.000m3/day of pumping rate.
• Private wells
T\
Report on investigaed results of arsenic pollution in groundwater in Hanoi city "=>
f
' Geological and Mineral Survey of Vietnam - The Northern HEG Division ____________
These wells are in the other organizations : enterprise, factories. These wells are in
medium diameter. There are one or some wells in each organization with medium
pumping rate. According to the preliminary investigation there are about 500
private wells in Hanoi area with 120.000m3/day of pumping rate in 2000.
• UNICEF wells.
Since sponsorship of the UNICEF, the rural areas and areas which still not receive
public water supply system are used groundwater through UNICEF wells. These wells
are in small diameter, using hand pump, each house has one well with 0.5-3m3/day.
Now this water supply system has improved, in some commune there is public water
supply system by one or some big wells. According to the un-detailed data (1997), 4
suburban districts have ten thousand these wells with 30.000m3/of pumping rate.
II.
Work quantity and method
ILL Survey for sampling points
We survey in the field to determine location of sampling points in two main
aquifers and some points for surface water and waste water:
- Sampling points are observation wells of the National Groundwater Regime
Monitoring Network and of Hanoi Groundwater Regime Monitoring
Network. These nets are operating in long term with 115 boreholes. These
boreholes are optimal conditions, which are recorded in geological structure,
groundwater regime.
- Sampling points are private wells. These wells are investigated in long term
of the the Northern Hydrogeological Engineering Geological Division. We
had located by GPS in 91 points.
-
Sampling points are UNICEF wells. These points distribute evenly in the
rural area. These points are located by GPS with 264 wells.
- Sampling point are 15 surface water points in the rivers, lakes and 15 points
of waste water from big factories and in industrial area. These points are
located by GPS.
II.2. Sampling and analysing
II.2.1. Sampling equipment and regulation
- For observation wells: used equipment is submerged pump SP-1 with 48mm
of diameter, 1.5-3m3/h of capacity, Honda electric Generator 1.5KW of
capacity, pumping out 3 water columns before sampling.
- For UNICEF wells: Using hand pump, pumping out 3 water columns before
__
n
sampling.
Report on investigaed results of arsenic pollution in groundwater in Hanoi city "=>
_
Geological and Mineral Survey of Vietnam - The Northern HEG Division ___________
-
For private wells: water samples are taken in the raw water tape of the pump
station.
- For surface water and waste water: samples are taken in the main out drains
( waste water) and in the middle place of the river or 3m of distance to lake
bank.
- Sample containers are 11 plastic bottle . For heavy metal, arsenic samples
they are acidified by HCL until pH = 2.
- The field parameters are: pH, Eh, EC, DO, Alkalinity, ammonia. The iron,
manganese, arsenic samples are sen to the laboratory and analysed not over
48h after sampling.
11.2.2. Quantity of sampling and method of analysing
The quantity of sampling and analysing are presented in the under table.
Table 1. Quantity of sampling and analysing
No
1
2
3
4
5
1
2
Sampling location
Quantity
Remarks
I. Surface water
Red river
4
Duong river
1
Ca"u river
1
1
Ca L6 river
Lake- pond
8
II. Waste water
Gia lam area
6
Urban - south of Red river area
9
III. qh aquifer
1
2
3
4
5
6
17
49
20
72
55
47
Soc Soti district
D6ng Anh district
Gia Lam district
Thanh Tri district
Tu: Liem district
Urban districts
IV. qp aquifer
1
2
3
4
5
6
Soc Son district
D6ng Anh district
Gia Lam district
Thanh Tri district
TO Li£m district
Urban districts
Total
=1
17
29
72
24
25
43
500
Report on investigated results of arsenic pollution in groundwater in Hanoi city &
^
T- ) Geological and Mineral Survey of Vietnam - The Northern HEG Division
______
Beside that 55 arsenic samples are analysed for checking:
- 50 samples are analysed in the Centre for Environmental Technology and
sustainable development - University for Natural Science
- 5 samples are analysed in the Analytical and Experimental Centre for
Geology
H.2.3.Analysis Criteria and Method:
> The field parameters are analysed by the Centre for Environmental
Technology and sustainable development - University for Natural
Science like pH, temperature, EC, DO, Alkalinity, ammonia with mobile
laboratory with following accuracy: pH (O.OlpH), temperature (0.1°C),
EC (l^S/cm), DO (O.lmg/1), Eh (l-3mV), alkalinity (lmg/1);
> Arsenic, iron, manganese samples are analysed in the laboratory of the
Analytical and Experimental Centre for Geology. The analysis method is
Atomic absorption spectrometry (AAS) - hydrated with 0.0002mg/l of
sensitivity.
III.
Creating database:
> Creating document for sampling points: The documents of the sampling
points are created in MS Excel -Access.
> Updated all data in MS Excel- Access and Geography Information
System (GIS).
IV. Evaluate reliability of the analysed samples
To evaluate reliability of the analysed samples, specially arsenic samples we
took 5 samples for inner check in the Analytical and Experimental Centre for Geology
and 50 samples for outside check in Centre for Environmental Technology and
sustainable development - University for Natural Science. The results are as follows:
• Inner check samples in the Analytical and Experimental Centre for Geology:
Absolute error is 3.2%, R =0.88. They are meet standard limitation.
^A
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Report on investigaed results of arsenic pollution in ground-water in Hanoi city <=>
A
V ) Geological and Mineral Survey of Vietnam - The Northern HEG Division
Table 2. Result of inner check samples
No
1
2
3
4
5
Analysed sample
Content
Sample ident
(mg/1)
385
0.088
399
0.008
402
0.045
410
0.08
380
Average
0.045
Checked analysed samples
Sample
Content
indent
(mg/1)
500
0.129
501
502
503
504
0.005
0.044
0.064
0.058
Difference
(%)
0.041
-0.003
-0.001
-0.016
0.013
0.015
37.79
46.15
2.25
22.22
25.24
26.73
Figure 2. Reliability of the analysed data for arsenic
0.12 -]————————————————————————————————————————————————
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R = 0.88
0.1 -
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n no ———————————————————•———————^_r^~*^ ————————
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•
0
-1
0
——————— -r.--—— ——————,———————————,———————————,———————————,———————————,———————————,
0.02
0.04
0.06
0.08 0.1
0.12
Checked As content (mg/1)
Out-check samples in Centre for Environmental Technology and sustainable
development - University for Natural Science. The difference is from 0.001 to
0.137mg/l with occupation 0.00 to 197% spectively, relative coefficent R is 0.76.
These analysed resulst are ecceptable.
Table 3. Result of outside check samples
Analysed sample
Checked analysed samples
No
Sample
Content
Sample
Content
(%)
Difference
indent
indent
(mg/1)
(mg/1)
1
352
352
32.00
0.105
-0.040
0.145
2
47
47
0.008
140.43
0.007
0.0014
3
51
51
0.058
52.17
0.034
0.024
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/tepo/f on investigaed results of arsenic pollution in groundwater in Hanoi city "=>
0.14
V ) Geological and Mineral Survey of Vietnam - The Northern HEG Division
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
"^
359
365
95
364
64
370
66
226
221
254
13
232
428
248
293
298
332
326
5
342
321
337
477
480
489
485
484
479
483
473
9
15
492
26
303
302
309
494
0.011
0.074
0.067
0.137
0.063
0.117
0.062
0.019
0.002
0.031
0.013
0.007
0.009
0.013
0.173
0.121
0.138
0.083
0.009
0.095
0.053
0.107
0.093
0.047
0.049
0.102
0.019
0.113
0.104
0.132
0.006
0.005
0.046
0.015
0.051
0.072
0.082
0.001
359
365
95
364
64
370
66
226
221
254
13
232
428
248
293
298
332
326
5
342
321
337
477
480
489
485
484
479
483
473
9
15
492
26
303
302
309
494
0.0058
0.035
0.0665
0.1041
0.0343
0.097
0.023
0.0147
0.001
0.018
0.0069
0.001
0.0081
0.001
0.386
0.0771
0.001
0.072
0.0051
0.0944
0.05
0.156
0.131
0.028
0.0161
0.121
0.021
0.091
0.095
0.142
0.0057
0.0026
0.027
0.0109
0.056
0.184
0.079
0.001
0.005
0.039
0.001
0.033
0.029
0.020
0.039
0.004
0.001
0.013
0.006
0.006
0.001
0.012
-0.213
0.044
0.137
0.011
0.004
0.001
0.003
-0.049
-0.038
0.019
0.033
-0.019
-0.002
0.022
0.009
-0.010
0.000
0.002
0.019
0.004
-0.005
-0.112
0.003
0.000
Report on investigaed results of arsenic pollution in groundwater in Hanoi city O
61.90
71.56
0.75
27.29
58.99
18.69
91.76
25.52
66.67
53.06
61.31
150.00
10.53
171.43
76.21
44.32
197.12
14.19
55.32
0.63
5.83
37.26
33.93
50.67
101.08
17.04
10.00
21.57
9.05
7.30
5.13
63.16
52.05
31.66
9.35
87.50
3.73
0.00
10
t
42
43
44
45
46
47
48
49
50
Geological and Mineral Survey of Vietnam - The Northern HEG Division
311
276
270
203
90
377
381
380
373
Average
311
276
270
203
90
377
381
380
373
0.032
0.005
0.076
0.002
0.059
0.056
0.006
0.05
0.037
0.017
-0.001
-0.031
0.001
0.005
0.013
0.002
-0.006
0.008
0.022
0.015
0.0063
0.107
0.001
0.054
0.043
0.0038
0.056
0.029
72.34
23.01
33.88
66.67
8.85
26.26
44.90
11.32
24.24
46.79
Figure 3. Reliability of the analysed data for arsenic
0.16 -I————————————————————————————————————————————————
R = 0.76
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Ascheck content (mg/l)
V.
Evaluate groundwater pollution.
General conception of groundwater pollution: the increasing of concentration
versus time of certain criteria in groundwater, which having harmful characters for
certain purposes. However, this study is still not met the above mentioned concept.
To get basic for evaluation of groundwater quality as well as groundwater
pollution we use Vietnam standard TCVN 5501-1991 for drinking water, which are
approved by Government and issued in 1991, environmental standard VN5944-1995
for surface water and waste water issued by Ministry of Technology Science and
Environment; beside that we use other standard WHO 1993. So temporally, the higher
concentration of criteria comparing with stadard limitation are contaminant.
To evaluate groundwater pollution by arsenic, we assume that there are two
aquifers: the upper aquifer is of Holocene aquifer (qh) and the upper of Pleistocene
1 Report on investigaed results of arsenic pollution in groundwater in Hanoi city *$
11
(
V ) Geological and Mineral Survey of Vietnam - The Northern HEG Division____________
aquifer (qp2), which is sources fro UNICEF wells in rural area. The lower aquifer is
lower part of the pleistocene (qpO, which is sources for industrial wells ( public wellfields and private wells.
Before evaluation of groundwater pollution, the quality of surface water and
waste water is evaluated.
V.I. Status of quality in surface water
15 surface water samples are analysed. The results are presented in the table 4
and fig. 4, 5, 6, 7.
4 criteria: ammonia and heavy metals: As, Fe, Mn comparing with TCVN 59441995:
•
Arsenic (As): there is 1 sample having higher content occupying 6.7%. The
maximum value is 0.196mg/l (dam in Phu Linh - Soc Son), 3.9 time higher
than standard limitation (0.05mg/l). The minimum content is <0.003mg/l.
• Manganese (Mn): there are 9 samples having higher content occupying 60%.
The maximum value is 0.38mg/l (in Van Tri lagoon- Dong Anh), 3.8 time
higher than standard limitation (O.lmg/1). The minimum content is <0.02mg/l.
• Iron (Fe): there are 5 samples having higher content occupying 33.3%. The
maximum value is 3.2mg/l (in Linh Dam pond- Thanh Tri), 3.2 time higher
than standard limitation (l.Oing/1). The minimum content is <0.22mg/l.
Ammonia (NH4+): there are 3 samples having higher content occupying 20%.
The maximum value is 5.9mg/l (in Bay Mau lake- Hai Ba Trung district), 1.97
time higher than standard limitation (3mg/l). The minimum content is
<0.02mg/l.
V.2.. Status of quality in waste water
There are 15 waste water samples taking in the vulnerable pollution industrial
area. The results are presented in the table 5 and fig. 4, 5, 6, 7.
15 analysed samples with 4 criteria: ammonia and heavy metals: As, Fe, Mn
comparing with TCVN 5944-1995. We divide into 2 areas:
•1* Gia Lam- Sai Dong area: 6 samples
• Arsenic (As): there is not any sample having higher content comparing with
standard limitation (0.05mg/l). The maximum value is 0.046mg/l (Due Giang
chemical factory),
•
•
_—
'*
Manganese (Mn): there are 5 samples having higher content comparing with
standard limitation (O.lmg/1) occupying 83.3%. The maximum value is
0.97mg/l (Due Giang chemical factory), 9.7 time higher than standard
limitation (O.lmg/1).
——
Report on investigaed results of arsenic pollution in groundwater in Hanoi city *$
( Y A
\
V ; Geological and Mineral Survey of Vietnam - The Northern HEG Division_____________
•
Iron (Fe): there are 6 samples having higher content occupying 100%. The
maximum value is 4.2mg/l (Due Giang Petrol Company), 4.2 time higher than
standard limitation (l.Omg/1).
• Ammonia (NH4+): there are 2 samples having higher content comparing with
standard limitation (3mg/l) occupying 33.3%. The maximum value is
40.8mg/l (Due Giang Petrol Company), 13.6 time higher than standard
limitation (3mg/l).
* South of Red river area: 9 samples are taken in this area.
•
Arsenic (As): there is not any sample having higher content comparing with
standard limitation (0.05mg/l). The maximum value is 0.046mg/l (Kirn Nguu
waste water river),
• Manganese (Mn): there are 8 samples having higher content comparing with
standard limitation (O.lmg/1) occupying 88.9%. The maximum value is
0.54mg/l (Kim Nguu waste water river), 5.4 time higher than standard
limitation (O.lmg/1).
•
Iron (Fe): there are 9 samples having higher content comparing with standard
limitation (l.Omg/1) occupying 100%. The maximum value is 6.2mg/l (CaoXa-La area), 6.2 time higher than standard limitation (l.Omg/1).
•
Ammonia (NH4+): there are 7 samples having higher content comparing with
standard limitation (3mg/l) occupying 77.8%. The maximum value is
58.1mg/l (Van Dien battery factory), 19.3 time higher than standard limitation
(3mg/l).
V.3. Status of groundwater pollution in upper aquifer
260 samples are taken in this aquifer. The study area is divided in to 3 areas.
The north area in the Socson, Dong Anh districts, the SE area between Red river
and Duong river, the south area in two suburban districts Thanh Tri - Tu Liem
and urban districts. The analysed results are presented in the table 6 and figure 4,
5, 6, 7. Four analysed criteria ( ammonia, As, Fe, Mn) are comparing with
standard limitation TCVN 5501-1991:
»«*
The north area: 66 samples in 66 points
•
Arsenic (As): there is 4 samples having higher content comparing with
standard limitation ( 0.05mg/l) occupying 6.1%. The maximum value is
0.08mg/l (Co Loa mechanical factory), 1.6 time higher than standard
limitation (0.05mg/l).
•
Manganese (Mn): there are 44 samples having higher content comparing
_____
with standard limitation (O.lmg/1) occupying 66.7%. The maximum value is
^-•' Report on investigaed results of arsenic pollution in groundwater in Hanoi city ^
13
) Geological and Mineral Survey of Vietnam - The Northern HEG Division
4.47mg/l (Well of owner Nguyen Dinh Chien - Van Ha - Dong Anh), 44.7
time higher than standard limitation (O.lmg/1).
• Iron (Fe): there are 27 samples having higher content comparing with
standard limitation (l.Omg/1) occupying 36.4%. The maximum value is
44.3mg/l (Due Giang Petrol Company), 147 time higher than standard
limitation (l.Omg/1)• Ammonia (NH4+): there are 2 samples having higher content comparing
with standard limitation (3mg/l) occupying 3%. The maximum value is
57.6mg/l (in well of owner Dao Van Loi - Dong Anh), 19.2 time higher than
standard limitation (3mg/l).
*J»
The SE area: 20 samples in 20 points.
• Arsenic (As): there is 8 samples having higher content comparing with
standard limitation ( 0.05mg/l) occupying 40%. The maximum value is
0.274mg/l (in well P80b Or Kho'i - Gia Lam), 5.48 time higher than standard
limitation (0.05mg/l).
•
Manganese (Mn): there are 19 samples having higher content comparing
with standard limitation (O.lmg/1) occupying 95%. The maximum value is
3.51mg/l (in well P49b Long Bien - Gia Lam ), 35.1 time higher than
standard limitation (O.lmg/l).
•
Iron (Fe): there are 12 samples having higher content comparing with
standard limitation (l.Omg/1) occupying 60%. The maximum value is
54.6mg/l (in well P49b Long BiSn - Gia Lam), 147 time higher than standard
limitation (l.Omg/1).
• Ammonia (NH/): there are 2 samples having higher content comparing
with standard limitation (3mg/l) occupying 3%. The maximum value is
57.6mg/l (in well of owner Mr. Dao Van Loi - Dong Anh), 19.2 time higher
than standard limitation (3mg/l).
<«
The SE area: 20 samples in 20 points.
• Arsenic (As): there is 8 samples having higher content comparing with
standard limitation ( 0.05mg/l) occupying 40%. The maximum value is
0.274mg/l (in well P80b Cut Kho'i - Gia Lam), 5.48 time higher than standard
limitation (0.05mg/l).
• Manganese (Mn): there are 19 samples having higher content comparing
with standard limitation (O.lmg/1) occupying 95%. The maximum value is
3.51mg/l (in well P49b Long Bien - Gia Lam ), 35.1 time higher than
standard limitation (O.lmg/1).
—
__
F
'
Report on investigaed results of arsenic pollution in groundwater in Hanoi city *$
Geological and Mineral Survey of Vietnam - The Northern HEG Division
•
Iron (Fe): there are 12 samples having higher content comparing with
standard limitation (l.Omg/1) occupying 60%. The maximum value is
54.6mg/l (in well P49b Long Bien - Gia Lam), 147 time higher than standard
limitation (l.Omg/1).
• Ammonia (NH4+): there are 3 samples having higher content comparing
with standard limitation (3mg/l) occupying 15%. The maximum value is
30.7mg/l (in well P80b Or Kho'i - Gia Lam), 10.23 time higher than standard
limitation (3mg/l).
•»* The South Red river area: 174 samples in 174 points, in these there are 72
points in Thanh Tri district, 55 points in Tu Liem district, 47 points in urban
districts.
In Tu Liem district
•
Arsenic (As): there is 8 samples having higher content comparing with
standard limitation ( 0.05mg/l) occupying 14.5%. The maximum value is
0.216mg/l (in well P55b Thuong Cat), 4.32 time higher than standard
limitation (0.05mg/l).
•
Manganese (Mn): there are 46 samples having higher content comparing
with standard limitation (O.lmg/1) occupying 83.6%. The maximum value is
5.711mg/l (in well owner Mr. Nguyfen Van Bay -Thuong Cat), 57.1 time
higher than standard limitation (0. lmg/1).
•
Iron (Fe): there are 40 samples having higher content comparing with
standard limitation (l.Omg/1) occupying 72.7%. The maximum value is
36.8mg/l (in well owner Mrs. Nguyen Thi Tam- Metri ), 122 time higher
than standard limitation (l.Omg/1).
• Ammonia (NH4+): there are 10 samples having higher content comparing
with standard limitation (3mg/l) occupying 18.2%. The maximum value is
29.4mg/l (in well owner Mr. Nguy6n Van Loi - Tay Mo), 10 time higher
than standard limitation (3mg/l).
In Thanh Tri district
•
Arsenic (As): there is 43 samples having higher content comparing with
standard limitation ( 0.05mg/l) occupying 59.7%. The maximum value is
0.292mg/l (in well owner Mr. Dang Van Mui - Van Phuc), 5.84 time higher
than standard limitation (0.05mg/l).
•
Manganese (Mn): there are 59 samples having higher content comparing
with standard limitation (O.lmg/1) occupying 81.9%. The maximum value is
^' Report on investigaed results of arsenic pollution in groundwater in Hanoi city ^>
15
(
s
) Geological and Mineral Survey of Vietnam - The Northern HEG Division
•
•
>
•
•
•
_____
3.6mg/l (in well owner Mr. Tran Van De-Tran Phu), 36 time higher than
standard limitation (O.lmg/1).
Iron (Fe): there are 66 samples having higher content comparing with
standard limitation (l.Omg/1) occupying 91.7%. The maximum value is
139.9mg/l (in well P3b- Yen So ), 466 time higher than standard limitation
(l-Omg/l).
Ammonia (NH4+): there are 56 samples having higher content comparing
with standard limitation (3mg/l) occupying 77.8%. The maximum value is
260.9mg/l (in well owner Mr. Nguyln Van Thach - Vinh Quynh), 86.9 time
higher than standard limitation (3mg/l).
In the urban area: 47 samples in 47 points
Arsenic (As): there is 18 samples having higher content comparing with
standard limitation ( 0.05mg/l) occupying 38.3%. The maximum value is
0.331mg/l (in well owner Mrs Le Thi Bich- Quang An - Tay Ho), 6.62 time
higher than standard limitation (0.05mg/l).
Manganese (Mn): there are 44 samples having higher content comparing
with standard limitation (O.lmg/1) occupying 93.6%. The maximum value is
3.15mg/l (in well P58b - Hoan Kiem district), 31.5 time higher than standard
limitation (O.lmg/1).
Iron (Fe): there are 41 samples having higher content comparing with
standard limitation (l.Omg/1) occupying 93.6%. The maximum value is
119.9mg/l (in well P35b- Hai Ba Trung district ), 399 time higher than
standard limitation (l.Omg/1).
•
Ammonia (NH4+): there are 17 samples having higher content comparing
with standard limitation (3mg/l) occupying 36.2%. The maximum value is
41.8mg/l (in well owner Mr. Duong Nhat Huy - Trung Hoa - Cau Giay ),
13.9 time higher than standard limitation (3mg/l).
V.4. Status of groundwater pollution in lower aquifer
There are 210 sampling points in this aquifer, similar with the upper aquifer the
study area is divided in to 3 areas. The north area in the Socson, Dong Anh districts,
the SE area between Red river and Duong river in Gia Lam district, the south area in
two suburban districts Thanh Tri - Tu Liem and urban districts. The analysed results
are presented in the table 7 and figure 8, 9, 10, 11. 4 analysed criteria ( ammonia, As,
Fe, Mn) are comparing with standard limitation TCVN 5501-1991
*J*
The north area: 46 samples in 46 points
Isl'* Report on investigaed results of arsenic pollution in groundwater in Hanoi city ^>
16
I Geological and Mineral Survey of Vietnam - The Northern HEG Division____________
•
•
•
•
•J»
•
•
Arsenic (As): there is 4 samples having higher content comparing with
standard limitation ( 0.05mg/l) occupying 8.7%. The maximum value is
0.105mg/l (in well P65a - Hai Boi- Dong Anh), 2.1 time higher than standard
limitation (0.05mg/l).
Manganese (Mn): there are 33 samples having higher content comparing
with standard limitation (O.lmg/1) occupying 71.7%. The maximum value is
5.53mg/l (in well Q36 Dong Anh), 53.3 time higher than standard limitation
(O.lmg/1).
Iron (Fe): there are 33 samples having higher content comparing with
standard limitation (l.Omg/1) occupying 71.7%. The maximum value is
40.9mg/l (in well Q36 Dong Anh), 136 time higher than standard limitation
(l.Omg/1).
Ammonia (NH/): there are 3 samples having higher content comparing
with standard limitation (3mg/l) occupying 6.5%. The maximum value is
6.4mg/l (in well P.65a Hai Boi - D6ng Anh), 2.1 time higher than standard
limitation (3mg/l).
The SE area in Gia Lam district: 72 samples in 72 points.
Arsenic (As): there are 13 samples having higher content comparing with
standard limitation ( 0.05mg/l) occupying 13%. The maximum value is
0.185mg/l (in well P76a Long Bien - Gia Lam), 3.7 time higher than
standard limitation (0.05mg/l).
Manganese (Mn): there are 67 samples having higher content comparing
with standard limitation (O.lmg/1) occupying 93.1%. The maximum value is
5.43mg/l (in well of Mr. Bui Van Xuyen C6 Bi - Gia Lam ), 54.3 time higher
than standard limitation (O.lmg/1).
•
Iron (Fe): there are 51 samples having higher content comparing with
standard limitation (l.Omg/1) occupying 70.8%. The maximum value is
41.7mg/l (in well - Post office of Thuong Thanh commune - Gia Ltei), 139
time higher than standard limitation (l.Omg/1).
•
Ammonia (NH4+): there are 21 samples having higher content comparing
with standard limitation (3mg/l) occupying 29.2%. The maximum value is
251mg/l (in well of Agricultural University I - Gia Lam), 83.6 time higher
than standard limitation (3mg/l).
*
The South Red river area: 92 samples in 92 points, in these there are 24
points in Thanh Tri district, 25 points in Tu Liem district, 43 points in urban
districts.
^1
'* Report on investigaed results of arsenic pollution in groundwater in Hanoi city "=>
17
/ \x
V> -) Geological and Mineral Survey of Vietnam - The Northern HEG
J
\
Division____________
> In Tu Liem district
• Arsenic (As): there is 9 samples having higher content comparing with
standard limitation ( 0.05mg/l) occupying 36%. The maximum value is
0.213mg/l (in well in Dai Mo - Tu Liem ), 4.26 time higher than standard
limitation (0.05mg/l).
• Manganese (Mn): there are 22 samples having higher content comparing
with standard limitation (O.lmg/1) occupying 88%. The maximum value is
3.33mg/l (in well P52a Me Dinh ), 33.3 time higher than standard
limitation (O.lmg/1).
• Iron (Fe): there are 25 samples having higher content comparing with
standard limitation (l.Omg/1) occupying 100%. The maximum value is
244.5mg/l (in well P52a Me Dinh), 815 time higher than standard
limitation (l.Omg/1).
•
Ammonia (NH4+): there are 9 samples having higher content comparing
with standard limitation (3mg/l) occupying 36%. The maximum value is
22.2mg/l (in well P25a Me Tri), 7.4 time higher than standard limitation
(3mg/l).
> In Thanh Tri district
•
Arsenic (As): there is 13 samples having higher content comparing with
standard limitation ( 0.05mg/l) occupying 54.2%. The maximum value is
0.166mg/l (in well of quarter of Ethnic Medicine Institute - Dinh Cong ),
3.32 time higher than standard limitation (0.05mg/l).
•
Manganese (Mn): there are 22 samples having higher content comparing
with standard limitation (O.lmg/1) occupying 91.7%. The maximum value
is 1.55mg/l (in well of the Repair Company for transportation work No IIThanh Tri), 15.5 time higher than standard limitation (O.lmg/1).
• Iron (Fe): there are 66 samples having higher content comparing with
standard limitation (l.Omg/1) occupying 91.7%. The maximum value is
139.9mg/l (in well P3b- Yen So ), 466 time higher than standard limitation
(l.Omg/1).
Ammonia (NH4+): there are 23 samples having higher content comparing
with standard limitation (3mg/l) occupying 95.8%. The maximum value is
34.9mg/l (in well of the private company for commercial equipment ), 25
time higher than standard limitation (3mg/l).
> In the urban area : 43 samples in 43 points
•
^
10
Report on investigaed results of arsenic pollution in gfoundwater in Hanoi city "=>
A
' ., \
¥
) Geological and Mineral Survey of Vietnam - The Northern HEG Division
Arsenic (As): there is 17 samples having higher content comparing with
standard limitation ( 0.05mg/l) occupying 39.5%. The maximum value is
0.192mg/l (in well P5a- Hai Ba Trung district), 3.84 time higher than
standard limitation (0.05mg/l).
Manganese (Mn): there are 40 samples having higher content comparing
with standard limitation (O.lmg/1) occupying 93.0%. The maximum value
is 9.38mg/l (in well P39a - Hai Ba Trung district), 93.8 time higher than
standard limitation (O.lmg/1).
Iron (Fe): there are 42 samples having higher content comparing with
standard limitation (l.Omg/1) occupying 97.7%. The maximum value is
150.8mg/l (in well Q64a- Dong Da district), 502 time higher than standard
limitation (l.Omg/1).
Ammonia (NH4+): there are 12 samples having higher content comparing
with standard limitation (3mg/l) occupying 27.9%. The maximum value is
48mg/l (in well P41a - Ha Dinh ), 16 time higher than standard limitation
(3mg/l).
^rl Report on investigaed results of arsenic pollution in groundwater in Hanoi city O
19
^
Geological and Mineral Survey of Vietnam - The Northern HEG Division
Table 4. Analysed results in surface water and standard limitation
No
Sample points
No
Type of Symbo
of
Commune
samp
water
1
le
1 N. M£t
NM Trung Gi •
District
X
Y
Mn
As
Pe
6.4
5.1
69
16 .4
0.31
0.006
0.200
2.26
Sac S-in
18586900 2354690
18.6
6.9
46.6
4.3
69
16 .4
0.31
0.196
0.020
0.24
Ph6 Minh
Sac S-m
18584649 2343982
18.9
6.8
130.8
3.7
33
95.1
0.25
0.009
0.120
0.89
§«ng Anh
18581229 2339428
23.0
7.4
106.5
6.1
21
90.8
0.02
0.003
0.380
0.22
Ba Sxnh
18584416 2326538
23.6
7.5
318.0
70.0
66
117
4.67
0.007
0.150
0.24
Sia L°m
18594339 2331888
22.5
6.6
134.2
0.2
4
112
0.09
0.009
0.070
0.91
Sia L°m
18596098 2319810
Hai Bfi Tr- -
22.0
7.9
0.0
6.5
15
97.4
0.35
0.007
0.070
0.51
19.4
8.2
484.0
6.3
70
158
5.93
0.031
0.112
0.39
17.0
10.0
102.0
8.0
67
117
0.04
0.005
0.130
0.92
18588797 2328002
22.6
7.8
20.0
4.4
11
96.7
0.02
0.013
0.050
1.61
r°y H4
18586599 2328270
22.2
5.1
269.0
0.9
-5
128.6
2.59
0.013
0.220
1.03
rhanh Trx
rhanh Trx
rhanh Trx
16 Li'm
18587555 2319911
23.7
7.9
354.0
8.4
10
197.4
0.75
0.007
0.220
3.24
18590100 2317948
21.0
6.9
322.0
0.3
-28
188
0.14
0.043
0.150
1.04
18592452 2318325
22.5
6.4
134.0
0.0
10
18
5.91
0.004
0.090
0.97
18580044 2333227
21.7
7.2
148.0
6.1
-2
108
0.74
N. MSt
NM
3
N. MKt
NM
4
N. MXt
NM Kirn Nc
Ha Gilng Va
S«ng §ueng
16 N. M8t
6
5
1. MJEt
NM CCu Sueng
7
S«ng BXc Hng Hli
6
SI. MJEt
NM B.t Trying
8
Ha Ely MEu
14
N. MSt
NM
Ha Ho^n KiOm
15 N. M«t
NM
L" S»i Hfinh ng
H^ng Trdng Ho^n KiOm
18587887 2324305
9
18588451 2326476
10
S«ng Hang 2
20 N. M«t
NM
Phoc X.
Ho/in KiQm
Gilng Va
Ha T«y
13 N. M*t
NM Thup Kh'
12
3a Linh §^m
17 N. M*t
NM
Ho^ng Li6t
13
Ha Y'n Se
18 N. M*t
NM
Y'n Se
14
S«ng Hang 3
21 N. MJBt
15
CSng Thuji Ph-mg
19 N. M£t
Trgn Ph6
NM rhup Ph-ing
NM
NH4 +
Phi Linh
2
" 11
Alkalin
ity
Eh
6 .7
§Ep nic
S«ng CM La
§Em V°n TRx
NM
DO
19.0
2
5
EC
18590706 2359212
S«ng CCu
4
PH
Sac Sin
1
3
ToC
0.18
0.008
0.050
Total
15
15
15
15
standard TCVN 5944 - 1995
3.0
0.05
0.1
1.0
3
1
9
5
Numcer of samples which
having higher content
comparing with standard
% of these samples
Maximum content
•a
Report on investigaed results of arsenic pollution in groundwater in Hanoi city ^
20
20.0
6.7
60.0
33.3
5.9
0.196
0.380
3.2
^
Geological and Mineral Survey of Vietnam - The Northern HEG Division
Table 5. Analysed results in waste water and standard limitation
No of
Sample points
NO
1
sampl
2
Type
Symbo
of
e
water
3
4
1
Commune
District
X
Y
ToC
pH
EC
DO
Eh
Alkalin
ity
5
6
7
8
9
10
11
12
13
14
15
NH4 +
As
Mn
Fe
'16
17
18
19
1. Gia L®m - S^ii Sang area
Sh/j m.y ho. chfit
1
N.
§0c Giang
7
Cty x"ng dCu §0c
2
th.i
NT
§0c Giang 3ia L°m
18592284 2331284
27.8
7.2 1010.0
NT
§0c Giang 3ia L^m
18592881 2330590
21.8
6.9
NT
Th'ch B/m 3ia L°m
18594483 2326910
27.0
NT
Th'ch Bfin Gia L°m
18595122 2325851
NT
Tr°u Quil
3ia L®m
NT
B . t Tr^ng Gia L°m
0.8
21
273.0
8.79
0.046
0.97
1.46
487.0
- 0.3
21
298.8
40.80
0.016
0.29
4.21
6.6
0.2
3.1
28
65.7
2.55
0.006
0.14
0.60
28.3
9.4
269.0
7.5
3
64.2
0.28
0.002
0.65
1.27
18597818 2325187
24.5
7.1
30.0
3.1
20
120.7
0.02
0.006
0.24
0.79
18596753 2320936
22.0
7.6
35.0
4.9
17
117.7
0.10
0.003
0.03
0.41
6
3.0
6
0.05
6
0.1
6
1.0
0
0.0
0.046
5
83.3
0.970
6
100.0
4.2
0.046
0.54
4.31
0.015
0.05
0.59
0.013
0.26
1.88
N.
Siang
8
th.i
N.
3
Khu CN S/ii §ang
9
4
NM g'ch Th'ch Bpn
10
5
Chl Tr«u Quti
11
6
L^ng gem
12
th.i
N.
th.i
N.
th.i
N.
th.i
Joto/
standard TCVN 5944 - 1995
Numcer of samples which having
higher content comparing with
standard
% of these samples
Maximum content
2
33.3
40.8
2 . South of Red river area
7
25
8
S«ng Kim Ngu
Nhji m.y dot Minh
Khai
9
Khu T°n Mai
28
26
N.
th.i
N.
th.i
N.
th.i
NT
Quunh Mai Hai BH Trng 18589583 2323742
22.7
7.8
421.0
1.5
160
277.8
NT
Minh Khai Hai BH Trng 18590106 2323185
25.0
7.8
415.0
1.5
189
76.0
NT
T°n Mai
Hai B^i Trng 18588572 2321520
25.5
7.8
420.0
3.0
16
378.2
NT
rhanh LiOt rhanh Trx
18584168 2318483
21.6
5.1
494.0
1.3
47
322.4
0.21
0.023
0.31
1.51
NT
yn se
rhanh Trx
18590015 2320723
22.8
5.6
400.0
0.4
5
292.0
19.47
0.011
0.41
2.67
NT
rhanh LiOt rhanh Trx
18584641 2318914
22.6
7.4
85.0
1.0
24
343.0
23.96
0 .004
0.26
1.78
48.17
0.08
42.11
N.
10
S«ng T« Ltch
22
th.i
N.
11
12
S«ng Lo
NM S-'n Tseng Hip H^
Nei
t
24
th.i
N.
29
th.i
Report on investigaed results of arsenic pollution in groundwater in Hanoi city O
21
u?
Geological and Mineral Survey of Vietnam - The Northern HEG Division
N.
13
SJM Pin V"n §i6n
30
th.i
NT
V " n § i6n
Thanh Trx
18587463 2317131
21.7
7.4
882.0
2.5
11
125.0
58.12
0.025
0 .20
0.77
ffi
341.0
2.2
14
326.1
27.30
0.011
0.20
1 . 21
0.4
25
347.0
29.52
16
0.003
17
9
3.0
9
0.05
7
77.8
58.1
0.0
0.046
N.
14
S«ng SDt
23
15
1
Cao X/i L,
27
2
3
th.i
N.
th.i
4
NT
Ph--ng LiOt rhanh Xu n
18587416 2322486
26.2
7.2
NT
5
Thing §xnh Thanh Xu°n
7
6
18584620 2322575
8
9
22.4
7.4
6.18
10
11
Total
standard TCVN 5944 - 1995
Numcer of samples which having
higher content comparing with
standard
% of these samples
Maximum content
84.0
12
13
14
15
0
0.35
18
9
19
c
0.1
1 .0
8
88.9
0.540
100.0
6.2
9
General areas
Total
15
15
15
15
standard TCVN 5944 - 1995
3.0
0.05
0.1
1.0
Numcer of samples which having
higher content comparing with
standard
% of these samples
Maximum content
^
Report on investigaed results of arsenic pollution in groundwater in Hanoi city ^
22
9
0
13
15
60.0
0.0
86.7
100.0
58.1
0.046
0.970
6.2