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IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT)
e-ISSN: 2319-2402,p- ISSN: 2319-2399.Volume 15, Issue 6 Ser. II (June 2021), PP 59-66
www.iosrjournals.org
DOI: 10.9790/2402-1506025966 www.iosrjournals.org 59 | Page
Assessment of Water Quality Parameters and Associated Health
Impacts of Supplied Drinking Water in Mohakhali and Banani Area
of Dhaka City, Bangladesh
Md. Ishtiak Hossain1, Dr. Shamsunnahar Khanam2 and Md. Arifur Rahman
Bhuiyan3
1(Department of Environmental Science, Faculty of Science and Technology, Bangladesh University of
Professionals (BUP), Dhaka, Bangladesh)
2(Department of Environmental Science, Faculty of Science and Technology, Bangladesh University of
Professionals (BUP), Dhaka, Bangladesh)
3(Department of Environmental Science, Faculty of Science and Technology, Bangladesh University of
Professionals (BUP), Dhaka, Bangladesh)
Abstract:
Background: Dhaka, the capital city of Bangladesh has been struggling to provide its dwellers with safe drinking
water and being the only supplier, DWASA (Dhaka Water Supply & Sewerage Authority) is responsible for
providing water supply in Dhaka city.
Materials and Methods: This study aimed to identify the water quality conditions and to identify the impacts of
water quality on human health. To serve this purpose, the study was conducted by collecting water samples from
different locations of Mohakahli (Korail Basti) and Banani area of Dhaka City and an in-depth questionnaire survey
was also carried out randomly on 75 people of those area.
Results: The study found that 75% of tap water and 50% of the distribution line water were contaminated with total
coliform. From the questionnaire survey, it was revealed that, about 41% of the respondents suffered from water-
borne diseases in the last year. 48% of the respondent were not consuming the supplied water by DWASA due to
odor. About 56% of the respondents agreed that the faulty water distribution line is the main reason for water
contamination.
Conclusion: Findings of this paper will help to the DWASA, Government policymaker to formulate policy in the
broader aspect that will ensure to solve the problem.
Key Word: Drinking Water Quality; DWASA; Water Security; Water Pollution; Human Health.
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Date of Submission: 14-06-2021 Date of Acceptance: 28-06-2021
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I. Introduction
Dhaka is the largest urban city in Bangladesh with a population density of 44,500/km2. Dhaka Water
Supply and Sewerage Authority (DWASA) is the sole legal entity to maintain water supply for the dwellers. 78% of
DWASA water comes from underground, which leads to incremental depletion of groundwater1. Most of the
distribution system has been weak because of the intermittent water supply, leakage, and pollution from old and
dilapidated sewerage pipes and storm drains. Distribution lines of the Dhaka WASA supply chain might be the main
source of microbiological contamination of drinking water causing water-borne diseases like Typhoid, cholera,
paratyphoid fever, dysentery, jaundice, etc.2. WASA supplied drinking water around Dhaka City and observed
pathogenic bacterial contamination and toxic PCP contamination which is alarming to the public health3. 64% of
city dwellers are not using the DWASA water for drinking purposes for bad smell. On the other hand, thirty-six
percent of people used the supplied water for drinking purposes by boil4.
Dhaka Water Supply and Sewerage Authority (WASA) estimates that per capita water demand in Dhaka is
150 liters per day. Meanwhile, per capita usage is just 85 liters per day among the households in informal
settlements (e.g. slums) with metered Dhaka WASA connections. Furthermore, inequality increases with increasing
wealth, for example, areas such as Gulshan and Banani have by far the highest per capita usage—509 liters. At
present Dhaka WASA faces several contraventions like, transitioning to managing surface water instead of
groundwater. The bacteriological quality of piped water supply has been extremely unsafe for drinking purpose.
Assessment of Water Quality Parameters and Associated Health Impacts ..
DOI: 10.9790/2402-1506025966 www.iosrjournals.org 60 | Page
The majority of the distribution system has been weak because of the intermittent water supply, leakage, and
pollution from old and dilapidated sewerage pipes and storm drains. Distribution lines of the Dhaka WASA supply
chain might be the main source of microbiological contamination of drinking water2. In Bangladesh, every year
more than one hundred thousand children under five years old die due to diarrhea-related diseases. In 2004 BDHS
(Bangladesh Demographic and Health Survey) reported that 5.1% of children died under five years and 1.2% of
neonatal deaths were related to diarrhea. Another study reported that 1% of neonatal deaths, 15% post-neonatal
deaths, and 6% under five age children’s deaths were associated with diarrhea5. A study found that typhoid,
bacillary dysentery, and diarrhea are very common among the bacterial origin waterborne diseases (table no 1)6.
Table no 1: Microbial sources of waterborne diseases
Disease
Microbial Agent
Source of Water Supply
Cholera
Vibrio cholerae
Water contaminated with the bacterium
E. coli infection
Certain strains of E. coli
Drinking water contaminated with bacteria
Dysentery
Spp. Of the genera Shigella and Salmonella with the
most common being Shigella dysenteriae
Water contaminated with the bacteria
Salmonellosis
Many bacteria of the genus Salmonella
Water contaminated with the bacteria. More common
as a foodborne illness
Typhoid fever
Salmonella typhi
Water contaminated with faces of an infected person
Water is considered safe when it is free from contamination. Due to use of contaminated water people
suffers from different type of water-borne diseases. In Bangladesh, there are lot of research conducted on water
quality assessment, but health effect covers a small part of whole work7.
The aim of this study was to assess the drinking water qualities (pH, Turbidity, TDS, conductivity, Total
coliforms, etc.) in water supply and its impact on human health at Mohakhali and Banani areas in Dhaka city,
Bangladesh; to identify the commonly occurred water-borne diseases; to identify the vulnerable age groups in the
study area, to aware the general people and to attract the attention of the respective concerns which may help them
taking necessary actions to bring the situation to a manageable condition.
II. Material And Methods
The study was conducted by collecting water samples from different locations of Mohakahli (Korail Basti)
and Banani area of Dhaka City and an in-depth questionnaire survey was also carried out randomly on 75 people of
those area. The study was conducted between January 2020 to December 2020.
Study location: Mohakahli (Korail Basti) and Banani, Dhaka, Bangladesh.
Primary data: Water quality analysis of the collected samples and health impact data obtained from the field survey
served as the primary data sources. These included: laboratory tests of collected water samples, questionnaire
survey, interview, field survey, etc. For the questionnaire, random sampling technique was followed, and questions
were both open and closed ended.
Secondary data: Keyword ‘Water quality assessment’ was used to search for research articles published between
2010-2020. Within this period a total of 74 articles were considered. Article classification was achieved via a 4-tier
assessment of (1) Title, (2) Keywords, (3) Abstract and (4) Full publication. The number of articles considered
within 2010-2020 is shown in Figure no 1.
Figure no 1: Academic publications on water quality assessment.
Assessment of Water Quality Parameters and Associated Health Impacts ..
DOI: 10.9790/2402-1506025966 www.iosrjournals.org 61 | Page
The selected articles were divided in source wise category, surface water category were 65 articles, ground water
category there were 02 articles, both ground and surface there was 1 article, and finally 6 articles were selected in
WASA or supply agency category (Figure no 2).
Figure no 2: Number of publications on the different water sources.
Sample collection: A total of 15 water samples were collected from water pumps, water reservoirs and from the
overhead tanks from different locations of the study area and were analyzed to determine pH, BOD, COD, TDS,
Total Coliform etc. The sample design for the research were a combination of simple random sampling and
stratified sampling.
Sample analysis techniques: Sample analysis techniques followed in this study in determining the parameters
collected water samples are shown in Table no 2.
Table no 2: Sample analysis techniques
Sl. No.
Water Quality Parameters
Bangladesh Standards (mg/L)
WHO Guidelines
Methods/ Equipment
01
BOD 5 Day, 200C
0.2
-
5 days Incubation
02
Chlorine (Residual)
0.2
-
Titrimetric Analysis
03
COD
4
-
Closed Reflux Method
04
Coliform (Faecal)
0 CFU (N/100mL)
0
Membrane Filtration Method
05
Coliform (Total)
0 CFU (N/100mL)
0
Membrane Filtration Method
06
Colour
15 Hazen
-
Colour Comparator
07
DO
6
-
Multimeter
08
Odour
Odourless
-
Threshold Method
09
pH
6.5-8.5
pH Meter
10
Salinity
-%0
-
Multimeter
11
Suspended Solids
10
-
Filtration and Drying
12
Taste
-
-
Threshold Method
13
Total Dissolved Solid
1000
-
Multimeter
14
Temperature
20-30C
Thermometer
15
Turbidity
10 NTU
-
Turbidity Method
Research plan:
Assessment of Water Quality Parameters and Associated Health Impacts ..
DOI: 10.9790/2402-1506025966 www.iosrjournals.org 62 | Page
Figure no 3: Research plan
III. Result
Findings from DWASA laboratory reports
The laboratory test report of DWASA for the supplied drinking water in the study area has been shown in Table no
3. Table no 3: Laboratory test report of DWASA
Parameter
pH
Turbidity
(N.T.U)
TDS
(mg/L)
Conductivity
(µs/cm)
Ammonia-N
(mg/L)
Total
Hardness
(mg/L)
Residual
Chlorine
(mg/L)
Total
coliforms
(N/100ml)
Drinking water
Standard
(WHO, 2011)
6.5 - 8.5
5
1000
…..
1.5
….
0.6 - 1.0
0
Drinking water
Standard
(Bangladesh)
6.5 - 8.5
10
1000
…..
0.5
200 - 500
0.2 - 0.5
0
SL-01
6.9
3.08
145
272
0
98
0
0
GWR -01
6.8
3.01
145
273
0
98
0
0
DTW -01
6.9
2.7
143
271
0
96
0
0
SL -02
6.8
2.58
140
264
0
98
0
0
GWR - 02
6.9
1.07
148
277
0
120
0
7
DTW - 02
6.8
1.32
114
215
0
72
0
0
GWR - 03
6.9
1.76
115
216
0
78
0
0
GWR - 04
7.1
1.83
112
210
0
80
0
0
SL - 03
6.9
1.46
104
196.3
0
76
0.1
0
GWR - 05
7.1
1.67
106.1
192.2
0
80
0.1
0
DTW-03
7.8
1.5
110
208
0
74
0
0
DTW- 04
6.7
2.98
138
259
0
90
0
0
GWR-06
6.8
2.59
135
254
0
94
0
0
GWR-07
6.6
2.77
132
249
0
95
0
10
SL-04
6.7
2.16
142
266
0
78
0
0
GWR-08
6.69
1.1
120
226
0
80
0.4
0
GWR-09
7.45
2.68
138
300
0
112
0
0
GWR-10
7.23
1.04
140.5
307
0
108
0
0
** SL = Supply Line, GWR= Ground water reservoir, DTW= Deep Tube Well
pH: pH was found within permissible limits as prescribed by Bangladesh and WHO guideline.
Turbidity (N.T.U): Turbidity within range as set by Bangladesh and WHO guideline.
TDS (mg/L): TDS is under the limit of Bangladesh and WHO guideline.
Conductivity: Conductivity is more, does not meet the limit of Bangladesh and WHO guideline.
Ammonia-N (mg/L): Ammonia-N is under the limit of Bangladesh and WHO guideline.
Total Hardness (mg/L): Total Hardness is less than the limit of Bangladesh and WHO guideline.
Total coliforms (N/100ml): In the water of Ground water reservoir (GWR-02 and GWR-07) total coliforms
found. But we do not get any in supply line and water pump water.
Assessment of Water Quality Parameters and Associated Health Impacts ..
DOI: 10.9790/2402-1506025966 www.iosrjournals.org 63 | Page
Findings from laboratory investigation of collected water samples
The results obtained from analyzing the water samples that had been collected from the study area has been shown
in Table no 4.
Table no 4: Lab test results of collected water samples of the study area
Parameter
pH
Turbidity
(N.T.U)
TDS
(mg/L)
Conductivity (µs/cm)
Total coliforms
(N/100ml)
Comments
Drinking water
Standard (WHO)
6.5 - 8.5
5
1000
…..
0
Drinking water
Standard (Bangladesh)
6.5 - 8.5
10
1000
…..
0
Sample-01 (Tap
Water)
7.25
2.5
165
330
36
Not good for health
Sample-02
(DWASA DTW)
7.24
0.2
163
325
0
Satisfactory
Sample-03
(Tap Water)
7.09
2.7
199
397
10
Not good for health
Sample-04
(DWASA DTW)
6.85
0
180
360
0
Satisfactory
Sample-05
(Tap Water)
7.07
0.5
175
349
0
Satisfactory
Sample-06
(DWASA Distribution
Line)
7.13
0.2
164
330
4
Not good for health
Sample-07
(Tube well, DWASA
Supply)
7.25
0.0
146
312
16
Not good for health
Sample-08
(DWASA DTW)
6.94
1.2
155
309
0
Satisfactory
Sample-09
(Tap Water)
7.35
0.3
161
322
0
Satisfactory
Sample-10
(DWASA Distribution
Line)
6.88
1.67
106.1
192.2
10
Not good for health
Sample-11
(Tap Water)
7.12
0.0
163
326
0
Satisfactory
Sample-12
(underground
reservoir)
7.21
0.4
166
331
0
Satisfactory
Sample-13
(DWASA DTW)
6.92
0.7
155
310
0
Satisfactory
Sample-14
(Tap Water)
6.87
0.9
154
308
6
Not good for health
Sample-15
(Tap Water)
7.04
0.7
180
342
18
Not good for health
** SL = Supply Line, GWR= Groundwater reservoir, DTW= Deep Tube Well
pH: pH was found within the limit set by Bangladesh and WHO guideline
Turbidity (N.T.U): Turbidity was found under the limit for all samples as set by Bangladesh and WHO
guideline
TDS (mg/L): TDS was found within the permissible limit of Bangladesh and WHO guideline
Conductivity: Though no standard values were set in Who as well as in Bangladesh Guidelines, but it was
found higher in the case of all samples.
Water quality and human heath impact analysis (questionnaire survey)
To find out inherent problems of city dwellers due to the water supply system in Dhaka city and its associate impact
on city life, a field survey as questionnaire survey, informal interview, and open discussions was done on 75 people
who were living in the study area. Data obtained from the field survey are shown in Figures 04-09.
Assessment of Water Quality Parameters and Associated Health Impacts ..
DOI: 10.9790/2402-1506025966 www.iosrjournals.org 64 | Page
From
figure no 4, it can be clearly seen that 32% of the respondents think that the water quality of supply water is of
moderate quality. 24% of the respondent think that the water quality of supply water is bad, and 4% think that the
water quality of supply water is very bad. Only 24% of respondents think that water quality of supply water is good
and 16% of respondents think that water quality of supply water is very good. So, most of the consumers were not
satisfied with their supplied drinking water quality.
The study also revealed that 43% of the respondents use boiling of water for filtration while 34% used
filters to purify their drinking water and only 4% of respondents had claimed that they use bottled water. It was
surprising that 19% of the respondents said that they use no filtration methods to purify their drinking water (figure
no 5). Moreover, 52% of the respondents had claimed that they smell the odor from their supplied drinking water
(figure no 6) and 82% of the respondents said that they do not drink the water directly (figure no 7). The survey also
found that, 41% of the respondents had suffered from waterborne diseases in the last one year (figure no 8) and 56%
of the respondents had claimed that the faulty distribution line was the main source of water contamination in the
study area (figure no 9).
Figure no 4: Perception on quality of supply water.
Figure no 5: Type of treatment procedure.
Figure no 6: Bad smell in Supply water.
Figure no 7: Drink supply water directly.
Assessment of Water Quality Parameters and Associated Health Impacts ..
DOI: 10.9790/2402-1506025966 www.iosrjournals.org 65 | Page
IV. Discussion
The slum areas have degraded sanitation facilities often exposed to excreta causing microbial
contamination like coliform8. This has positive correlation with water-borne disease9 as observed among the 41%
respondent suffering from water-borne diseases. Turbidity plays a vital role to control disease forming
microorganisms10. The water samples result shows the turbidity to be within the range of WHO Standards. Majority
of the respondents (about 56%) claimed faulty distribution line for water contamination. A close proximity to drain
line could also cause microbial contamination resulting in bad odor11. The pathogens are highly susceptible for
elders, infants, and immune-compromised inhabitants and could result in acute gastroenteritis12. Besides, the higher
the number of dissolved ionic components in water causes more the conductivity13.
From overall observation, it can be concluded that there might be still existing some problems in water
supply lines as the results of the water sample analysis also suggested the existence of coliform bacteria in the
pipeline as well as in house tap water since some of the samples did not meet BD and WHO standards. So,
contamination may have taken place in the distribution system and domestic tanks or reservoirs. Field survey reports
also suggested that the consumers of the study area also faced some problems related to their drinking water sources.
The results emphasize the importance of adopting an appropriate routinely monitoring system in order to
prevent the chances of contamination of drinking water. To prevent the problems that have been identified through
this study, the following are the few remedial measures which can be adopted to retrieve the water qualities of the
study areas:
Service tanks should be cleaned regularly for ensuring a potable water supply to the consumer.
Pipelines can be placed under 5 to 6 feet from the surface for ensuring the safe supply of water and avoid
underground leakage.
Ensuring safe drinking water sources for the incumbents who have no WASA connection.
Use of water recycling systems.
Educate people on water pollution and its risks.
Enforce law to build a septic tank and effluent treatment plant properly.
Increase trained and equipped team for water quality monitoring and surveillance.
V. Conclusion
In most of the slums of Dhaka city, water is supplied from Dhaka WASA. But this water is supplied
through most of the illegal water connections. The slum areas are involved in illegal water connection systems by
leaking legal mains. So, there is some leakage in the connection pipes. The entrance of filthy things and dirty water
from drains in the WASA lines creates the water contaminated. Due to the use of dirty/contaminated water, people
suffer from various diseases and becomes deprived of getting safe water facility. Water purification is a cost-
Figure no 8: Evidence of water borne diseases
occurrence.
Figure no 9: Main source of water contamination.
Assessment of Water Quality Parameters and Associated Health Impacts ..
DOI: 10.9790/2402-1506025966 www.iosrjournals.org 66 | Page
effective process so most of the population in this area drinks tap water directly. For this reason, different water-
borne diseases are rising in the city. So, the government should create some effective rules and penalize the system
for the illegal connection. Findings of this paper will help to the DWASA, government policymakers to formulate
policy in the broader aspect that will ensure to solve the problem.
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Biofilm Reactor for the Treatment of Domestic Wastewater.” IOSR Journal of Environmental
Science, Toxicology and Food Technology (IOSR-JESTFT), 14(6), (2021): pp 59-66.
