040404124P-Main Thesis Paper

HEALTH IMPACTS OF URBAN WATER SUPPLY ON THE
VULNERABLE COMMUNITIES OF SELECTED AREAS OF
DHAKA CITY
MD. ZAMIL HOSSAIN MUNSHI
DEPARTMENT OF CIVIL ENGINEERING
BANGLADESH UNIVERSITY OF ENGINEERING & TECHNOLOGY
DHAKA, BANGLADESH
DECEMBER 2011

HEALTH IMPACTS OF URBAN WATER SUPPLY ON THE VULNERABLE
COMMUNITIES OF SELECTED AREAS OF DHAKA CITY
by
Md. Zamil Hossain Munshi
A thesis submitted to the Department of Civil Engineering,
Bangladesh University of Engineering & Technology, Dhaka
in partial fulfillment of the requirements for the degree
of
MASTER OF SCIENCE IN CIVIL ENGINEERING
DEPARTMENT OF CIVIL ENGINEERING
BANGLADESH UNIVERSITY OF ENGINEERING & TECHNOLOGY
December 2011

ii
The thesis titled “HEALTH IMPACTS OF URBAN WATER SUPPLY ON THE
VULNERABLE COMMUNITIES OF SELECTED AREAS OF DHAKA CITY”
submitted by Md Zamil Hossain Munshi, Roll No: 040404124 (P), Session: 2004 has
been accepted as satisfactory in partial fulfillment of the requirement for the degree
of Master of Science in Civil Engineering (Environmental) on 03 December 2011.
BOARD OF EXAMINERS
1. -----------------------------------------------------------
Dr. Md. Mafizur Rahman Chairman
Professor
Department of Civil Engineering
BUET, Dhaka
2. -------------------------------------------------------------
Dr. Md. Mujibur Rahman Member
Professor and Head (Ex-Officio)
BUET, Dhaka
3. -------------------------------------------------------------
Dr. Md. Delwar Hossain Member
Professor
BUET, Dhaka
4. -------------------------------------------------------------
Major Muhammad Sohail-Us-Samad Member
Assistant Director (External)
Survey of Bangladesh, Dhaka

iii
CANDIDATE’S DECLARATION
It is hereby declared that this thesis or any part of it has not been submitted
elsewhere for the award of any degree or diploma.
---------------------------------------------------
Md. Zamil Hossain Munshi
Roll No: 040404124 (P)

iv
TABLE OF CONTENTS
CERTIFICATION ii
CANDIDATE’S DECLARATION iii
TABLE OF CONTENTS iv
LIST OF TABLES ix
LIST OF FIGURES xiii
LIST OF ABBREVIATIONS xviii
ACKNOWLEDGMENTS xix
ABSTRACT xx
CHAPTER 1: INTRODUCTION 1
1.1 General 1
1.2 Rationale of the Study 2
1.3 Objectives of the Study 4
1.4 Scope of the Study 4
1.5 Limitations of the Study 5
1.6 Organization of the Thesis 6
CHAPTER 2: LITERATURE REVIEW 7
2.1 Introduction 7
2.2 The Vulnerable Community 8
2.2.1 Definition 8
2.2.2 Considerations 8
2.2.3 Estimation of Population of a Community 9
2.2.4 Performance of Community Drinking-Water System 9
2.3 Water Pollution and Related Issues 9
2.3.1 Water Pollution 9
2.3.2 Types of Pollutants, Sources and Effects 10
2.3.3 Background Level of Immunity 13
2.4 Water Quality and Standards 13

v
2.4.1 Water Quality 13
2.4.2 Water Quality Standards 13
2.5 Water Supply 15
2.5.1 Objectives of Water Supply 15
2.5.2 Pattern of Urban Water Supply for Vulnerable Group 15
2.6 Domestic Water Supply 16
2.6.1 Domestic Water and its Usage 16
2.6.2 The Links Between Water Supply, Hygiene and Disease 17
2.7 Sanitation 18
2.7.1 Definition and Objectives of Sanitation 18
2.7.2 Relationships Between Water, Sanitation, Hygiene and
Diarrhoea 19
2.7.3 Relationships Between Water, Hygiene and Other
Infectious Diseases
21
2.7.4 Quantity and Accessibility 21
2.7.5 Hazards of Water Supply 22
2.8 Dhaka and Its Water Supply System 23
2.8.1 Growth of Dhaka 23
2.8.2 Dhaka Water Supply and Sewerage Authority (DWASA) 24
2.8.3 Water Supply Situation 26
2.8.4 Water Quality Monitoring System 27
2.9 Economic Valuation of Diseases 28
2.9.1 General 28
2.9.2 Importance of Monetary Valuation 28
2.9.3 The Major Economic Impacts of Pollution 29
2.9.4 Techniques to Place Monetary Values on Environmental
Impacts 29
2.10 Prevalence Rate (PR) 30
2.10.1 Importance 30
2.10.2 Formula Used in PR 31
2.11 Statistical Analysis Tools 31
2.11.1 Arithmetic Mean 31
2.11.2 Grade Point Average (GPA) 32
2.11.3 Standard Deviation 32

vi
2.11.4 Correlation Coefficient (Cr) 32
CHAPTER 2: METHODOLOGIES 33
3.1 Introduction 33
3.2 Methodologies 33
3.3 Design Procedure 35
3.3.1 Selection of Vulnerable Communities 37
3.3.2 Vulnerability Score 37
3.3.3 Identification of Urban Water Supply Options 38
3.3.4 Field Survey 38
3.3.5 Economic Valuation of Diseases 45
3.3.6 Prevalence Rate (PR) 47
3.3.7 Climatic factors 48
CHAPTER 4: ANALYSIS OF DATA 49
4.1 Introduction 49
4.2 Data Availability in Bangladesh 49
4.3 Selection of Data 49
4.3.1 Yearly Records 50
4.3.2 Monthly Records 53
4.3.3 Meteorological Data 53
4.4 Analysis of Field Data 57
4.4.1 Questionnaires Survey- An Overview 57
4.4.2 Qualitative Assessment 58
4.4.3 Quantitative Assessment 69
4.4.4 Economic Valuation of Diseases 77
4.4.5 Analysis of Prevalence Rate 79
4.5 Development of Correlation Between Diarrhoea Patient Reporting
Cases and Climatic Factors
81
4.5.1 Identification of Correlation 81
4.5.2 Development of Correlation Equation 84
CHAPTER 5: RESULTS AND DISCUSSIONS 87
5.1 Introduction 87
5.2 Qualitative Assessment 87

vii
5.2.1 Urban Water Supply Options 87
5.2.2 Distance of Water Source and Time Require to Fetch
Water
89
5.2.3 Quantity and Accessibility to Water 90
5.2.4 Water Boiling Practices 92
5.2.5 Storage of Water 93
5.2.6 Sanitation Systems 95
5.2.7 Hygiene Practices-Use of Hand Wash Medium 96
5.2.8 Water Quality of Collected Samples 98
5.2.9 Sanitary Inspection (SI) 101
5.3 Quantitative Assessment 104
5.3.1 Overall Evaluation on Health Impacts 107
5.4 Evaluation on Estimated Health Impact Valuation of Waterborne
Diseases 117
5.5 Evaluation of Prevalence Rate 118
5.6 Correlation Between Diarrhoea Patient Reporting Cases and
Climatic Factors 121
5.7 GIS Representation of Relevant Data in Thematic Maps 123
CHAPTER 6: CONCLUSIONS AND RECOMMENDATIONS 124
6.1 Conclusions 124
6.2 Recommendations 130
REFERENCES 131
APPENDICES
Appendix A Questionnaires Survey Form 135
Appendix B Sanitary Inspection Forms 139
Appendix C 15 Years (1996-2010) Averaged Diarroheal Patients
Reported
142
Appendix D 11 Years Monthly Average (2000-2010) Diarrhoeal Patients
Reported 143

viii
Appendix E Thana wise Estimated Population of Dhaka City for the
Year of 2010 144
Appendix F Data of Selected Climatic Factors for Dhaka Station 145
Appendix G Relevant Data From Questionnaires Survey 146
Appendix H Analysis of Sanitary Inspection (SI) Data 148
Appendix I Analysis of Water Quality of Selected Areas 152
Appendix J Overall Grading Based on Vulnerability Scores 155
Appendix K Estimated Health Impact Valuation of Waterborne Diseases
of Dhaka City 158
Appendix L Calculation of Prevalence Rate of Waterborne Diseases of
Selected Areas of Dhaka City 160
Appendix M Correlation Between Diarrhoeal Incidences and Climatic
Factors 164
Appendix N Criteria Wise Health Impacts of the Selected Communities,
Areas and Urban Water Supply Options 168
Appendix O Thematic Maps of Dhaka City 192

ix
LIST OF TABLES
Table 2.1 Heavy Metal Concentration in River Water of Dhaka City 11
Table 2.2 Concentration of Water Quality Indicators of Lake Water of
Dhaka City
11
Table 2.3 Bangladesh Water Quality Standards For Surface Water
For Water Supply
14
Table 2.4 Bangladesh Standard For Drinking Water 14
Table 2.5 Volumes of Water Required For Hydration For the Most
Vulnerable in Tropical Climates
19
Table 2.6 Infrastructures and Establishment of DWASA 28
Table 2.7 Source Wise Water Production of DWASA in October 2009 29
Table 3.1 Vulnerability Score and State of Vulnerability 37
Table 3.2 Basic Data for Grading and Representation 38
Table 3.3 The Water Supply Options Found in the Study Areas 38
Table 3.4 Data Filtering Process: Step-1 41
Table 3.5 Data Filtering Process for Diarrhoea: Step-2a 42
Table 3.6 Data Filtering Process for Typhoid: Step-2b 42
Table 3.7 Data Filtering Process for Eye Infections: Step-2c 43
Table 3.8 Final Result of Data Filtering Process 43
Table 3.9 Criteria Used For Grading the SI Risk Scores 44
Table 3.10 List of Laboratory Tests For Collected Water Samples 45
Table 3.11 Calculation of Hourly Average Wage Rate 46
Table 4.1 Generalized Population of Administrative Areas of Dhaka
City Reporting ICDDR, B in 2010
52
Table 4.2 Selected Thana Wise Different Age Groups Patients 52
Table 4.3 At a Glance of Dhaka City Climate 53
Table 4.4 Sample Area Wise Distribution of Interviewed HHs and
Exposed Population
58
Table 4.5 Age Group Wise Distribution of Interviewed Communities 58

x
Table 4.6 Distribution of number of HHs to Urban Water Supply
Options As Per Community Type And Connection Sources
59
Table 4.7 Distribution of Selected Area Wise Observed Water Points
To Urban Water Supply Options
61
Table 4.8 Distribution of Community Wise Observed Water Points to
Urban Water Supply Options
61
Table 4.9 Distribution of number of HHs Residing At Different
Distances From Water Sources.
61
Table 4.10 Distribution of Community Wise HHs Against Water Fetch
Time
62
Table 4.11 Distribution of Number of HHs Against Water Demand and
Water Sources' Connections
62
Table 4.12 Distribution of Community Wise Number of HHs Against
Water Demand and Urban Water Supply Options
63
Table 4.13 Sample Area Wise Number of HHs Reporting Occasional
Aesthetic Quality of Water
63
Table 4.14 Distribution of HHs of Different Community Types Against
Water Boiling Practices and Urban Water Supply Options
64
Table 4.15 Distribution of HHs Against Water Boiling Duration and
Urban Water Supply Options
64
Table 4.16 Distribution of HHs of Different Community With Respect to
Water Storage System at HH Level.
65
Table 4.17 Distribution of HHs of Different Selected Areas With
Respect to Water Storage System at HH Level.
65
Table 4.18 Distribution of HHs of Different Urban Water Supply System
With Respect to Water Storage System at HH Level.
65
Table 4.19 Sample Area Wise Distribution of HHs of Different
Communities Having Different Sanitation Systems
65
Table 4.20 Sample Area Wise Distribution of HHs of Different
Communities Showing Hand Washing Practices
66
Table 4.21 Area Wise Number of Samples of Different Faecal Coliform
Concentration
67
Table 4.22 Community Wise Number of Samples of Different Faecal
Coliform Concentration
67
Table 4.23 Urban Water Supply Option Wise Number of Samples of 67

xi
Different Faecal Coliform Concentration
Table 4.24 Area Wise Distribution of Number of Water Points As Per
Risk Grade
68
Table 4.25 Community Wise Distribution of Number of Water Points As
Per Risk Grade
68
Table 4.26 Urban Supply Options Wise Distribution of Number of
Water Points As Per Risk Grade
68
Table 4.27 Gender Wise Overall Incidences of Waterborne Diseases
of Different Age Groups
69
Table 4.28 Sample Areas Wise State of Waterborne Diseases’
Incidences of Different Gender
69
Table 4.29 Community Wise State of Waterborne Diseases’
Incidences
70
Table 4.30 Community Wise Waterborne Diseases’ Incidences With
Respect to Water Sources’ Connections
71
Table 4.31 Waterborne Diseases’ Incidences With Respect to Urban
Water Supply Options
71
Table 4.32 Community Wise Waterborne Diseases’ Incidences With
Respect to Urban Water Supply Options
72
Table 4.33 Waterborne Diseases’ Incidences With Respect to Distance
Between HH and Source
73
Table 4.34 Waterborne Diseases’ Incidences With Respect to Time
Taken to Fetch Water From Source
73
Table 4.35 Waterborne Diseases’ Incidences With Respect to Water
Received Against Demand
74
Table 4.36 Waterborne Diseases’ Incidences With Respect to Boiling
of Water.
74
Table 4.37 Waterborne Diseases’ Incidences With Respect to Time
Spent For Boiling of Water.
75
Table 4.38 Waterborne Diseases’ Incidences With Respect to Storage
of Water.
75
Table 4.39 Waterborne Diseases’ Incidences With Respect to Sanitary
Practices.
76
Table 4.40 Waterborne Diseases’ Incidences With Respect to Hand
Wash Media.
76

xii
Table 4.41 Overall Health Impacts Based on Water Quality (FC
Concentration)
77
Table 4.42 Waterborne Diseases’ Incidences With Respect to Risk
Grade.
77
Table 4.43 Cost of Waterborne Disease- Diarrhoea 78
Table 4.44 Cost of Waterborne Disease- Typhoid 78
Table 4.45 Cost of Waterborne Disease- Eye infections 79
Table 4.46 Basic Data For Prevalence Rate of Different Age-Groups 79
Table 4.47 Basic Data For Prevalence Rate of Different Community 80
Table 4.48 Basic Data For Prevalence Rate of Different Selected
Areas
80
Table 4.49 Basic Data For Prevalence Rate of Different Urban Water
Supply Options
80
Table 4.50 Correlation Coefficient of Climatic Parameters and
Diarrhoeal Incidences of the Selected Areas
84
Table 4.51 Selection of Correlation Equation Based on Correlation
Coefficients
85
Table 5.1 Number of Likely and Actual Diarrhoeal Incidences With
Respect to Temperature
122

xiii
LIST OF FIGURES
Figure 2.1 Disease Transmission and Sanitation 19
Figure 2.2 Interrelationship between Water, Sanitation and Health
Education
20
Figure 2.3 Graph of Travel Time (In Minutes) Versus Consumption 22
Figure 2.4 Generic Flow Diagram of Water Supply System 23
Figure 2.5 DWASA Service Areas in DMPA 25
Figure 2.6 Prediction of Population and Water Demand in Dhaka City 27
Figure 3.1 Methodology Diagram 34
Figure 3.2 Slums of Dhaka Metropolitan Area 36
Figure 4.1 Yearly Trends of Waterborne Disease’s Patients of Dhaka City 50
Figure 4.2 Children Patients Reporting DSH During 2005-06. 51
Figure 4.3 General Trend of Patients of Waterborne Diseases 53
Figure 4.4 Variations of Annual Rainfall of Dhaka city 54
Figure 4.5 Trend of Rainfall of Dhaka City 54
Figure 4.6 Variations of Average Annual Temperature of Dhaka city 55
Figure 4.7 Trend of Temperature of Dhaka city 55
Figure 4.8 Variations of Average Annual Humidity of Dhaka city 56
Figure 4.9 Trend of Average Annual Humidity of Dhaka city 56
Figure 4.10 Distribution of Population by Number of Person per HH 57
Figure 4.11 Sample Areas Wise Different Distance Range Between
Households and Water Sources.
62
Figure 4.12 Trend of Diarrhoeal Patients of Sample Area and Dhaka 81
Figure 4.13 Diarrhoeal Patients of Sample Area and Average Rainfall 82
Figure 4.14 Diarrhoeal Patients of Sample Area and Average Temperature 82
Figure 4.15 Diarrhoeal Patients of Sample Area and Average Humidity 82
Figure 4.16 Diarrhoeal Patients-Rainfall Correlation (2000-2010) 83

xiv
Figure 4.17 Diarrhoeal Patients-Temperature Correlation (2000-2010) 83
Figure 4.18 Diarrhoeal Patients-Humidity Correlation (2000-2010) 84
Figure 4.19 Average Diarrhoeal Patients-Temperature Correlation for Study
Areas and Dhaka as a Whole (2000-2010)
85
Figure 5.1 Overall State of Different Water Supply Options 88
Figure 5.2 Community wise State of Different Water Supply Options 88
Figure 5.3 Community Wise Different Distance Range Between Households
and Water Source.
89
Figure 5.4 Urban Water Supply Options Wise Different Distance Range
Between Households and Water Source.
90
Figure 5.5 Overall State of Different Distance Range Between Households
and Water Source.
90
Figure 5.6 State of Different Water Demand Against Community Type 91
Figure 5.7 State of Different Water Demand Against Urban Water Supply
Options
91
Figure 5.8 Overall State of Different Water Demand Fulfillment 91
Figure 5.9 Community Wise Percentages of HHs Having Water Boiling
Practices
92
Figure 5.10 Sample Area Wise State of Water Boiling Practices by HHs. 93
Figure 5.11 Overall State of Water Boiling Practices Observed in the Study
Area
93
Figure 5.12 Overall state of Different Water Storage System 94
Figure 5.13 Community Wise Number of HHs for Different Water Storage
System
94
Figure 5.14 Sample Area Wise Number of HHs for Different Water Storage
System
95
Figure 5.15 Distribution of HHs According to Sample Area Based on
Sanitation System in Use.
95
Figure 5.16 Overall State of Sanitary Practices in the Sample Area. 96
Figure 5.17 Overall State of Hygiene Practices 97
Figure 5.18 Community Wise Distribution of HHs Based on Hand Wash
Media.
97
Figure 5.19 Sample Area Wise Distribution of HHs Based on Hand Wash
Medium.
97

xv
Figure 5.20 Community Wise Percentages Of Households Reporting the
Aesthetic Quality of Water.
98
Figure 5.21 Overall State of Aesthetic Quality of Water of Study Area 99
Figure 5.22 pH Distribution of The Water Sample of Different Communities 99
Figure 5.23 pH Distribution Of The Water Sample Of Different Areas. 100
Figure 5.24 Microbial Water Qualities of Water Supply in Different
Communities.
101
Figure 5.25 State of Overall SI Risk Grading of Water points of Study Area 101
Figure 5.26 Comparative State of Communities Based on SI Risk Grading. 102
Figure 5.27 Overall State of Communities Based on SI Risk Grading. 102
Figure 5.28 Comparative State of Vulnerable Areas Based on SI Risk
Grading.
102
Figure 5.29 Overall State of Selected Areas based on SI Risk Grading. 103
Figure 5.30 Comparative State of Urban Water Supply Options Based on SI
Risk Grading.
103
Figure 5.31 Overall State of Urban Water Supply Options based on SI Risk
Grading.
104
Figure 5.32 Overall State of Waterborne Diseases of Interviewed Households 104
Figure 5.33 Gender Distributions of the Affected Persons 105
Figure 5.34 Comparison between Male and Female Diarrhoeal Incidences 105
Figure 5.35 State of Different Gender Age-Groups for Waterborne diseases 106
Figure 5.36 Overall Vulnerability of Communities 107
Figure 5.37 State of Vulnerability of Communities Based on Diarrhoea
Incidences
108
Figure 5.38 Correlation Between Demand And Number of Diarhoea
Incidences.
108
Figure 5.39 Correlation between FC Count and Diarrhoea Incidences in
Percentage.
109
Figure 5.40 State of Vulnerability of Communities Based on Typhoid
Incidences
109
Figure 5.41 State of Vulnerability of Communities Based on Eye Infections’
Incidences
110

xvi
Figure 5.42 Correlation Between SI Risk Score and Percentage of Eye
Infections’ Incidences Against Exposures.
110
Figure 5.43 The Order of Community Based on Cumulative Vulnerability
Scores
111
Figure 5.44 Overall Vulnerability of Selected Areas of Dhaka City 111
Figure 5.45 State of Vulnerability of Selected Areas Based on Diarrhoea
Incidences
112
Figure 5.46 State of Vulnerability of Selected Areas Based on Typhoid
Incidences
113
Figure 5.47 State of Vulnerability of Selected Areas Based on Eye Infections
Incidences
113
Figure 5.48 The Order of Selected Areas Based on Cumulative Vulnerability
Scores
114
Figure 5.49 Overall Vulnerability of Urban Water Supply Options 114
Figure 5.50 State of Vulnerability of Urban Water Supply Options Based on
Diarrhoea Incidences
115
Typhoid Incidences
115
Eye Infections Incidences.
116
Figure 5.53 The Order of Urban Water Supply System Options Based on
Cumulative Vulnerability Scores
116
Figure 5.54 Comparison Between the Cost of Non-Reporting Waterborne
Diseases, GDP at Current Price and GDP at Constant Price
(2009-10).
118
Figure 5.55 Prevalence Rate of Waterborne Diseases. 118
Figure 5.56 The State of PR Values of Different Genders 119
Figure 5.57 The State of PR Values of Different Age-Groups of Different
Genders Suffering From Diarrhoea.
119
Genders Suffering From Typhoid
120
Genders Suffering From Eye Infections
120

xvii
Figure 5.60 Projected Average Diarrhoeal Patients of Study Areas Based on
Temperature
121
Figure 5.61 Projected Average Diarrhoeal Patients of Dhaka Based on
Temperature
121
Figure 5.62 Average Maximum Temperature Profile at Different Time Range 122

xviii
LIST OF ABBREVIATIONS
BBS Bangladesh Bureau of Statistics
BCAS Bangladesh Centre for Advanced Studies
BMD Bangladesh Meteorological Department
BOD Biochemical Oxygen Demand
CBO Community Based Organization
CUS Centre for Urban Studies
DALY Disability Adjusted Life Year
DCC Dhaka City Corporation
DMA Dhaka Metropolitan Area
DO Dissolved Oxygen
DOE Department of Environment
DSH Dhaka Shishu Hospital
DWASA Dhaka Water Supply and Sewerage Authority
ECA Environmental Conservation Act
ECR Environment Conservation Rules
EPA Environmental Protection Agency (USA)
EQS Environmental Quality Standard
FC Faecal Coliform
GIS Geographical Information System
HH Household
ICDDR,B International Centre for Diarrhoeal Disease Research,
Bangladesh
IPH Institute of Public Health
ITN-BUET International Training Network Centre, BUET
LGED Local Government Engineering Department
MLD Million Litre per Day
STW Shallow Tubewell
TDS Total Dissolved Solid
UNDP United Nations Development Programme
UNICEF United Nations Children's Fund
UNEP United Nations Environment Programme
WHO World Health Organization
WTP Willingness to pay

xix
ACKNOWLEDGMENTS
The author wishes to express sincere gratitude to his Supervisor Dr. Md. Mafizur
Rahman for his continued guidance and encouragement throughout the whole
period of the thesis work. His careful guidance, constructive suggestions immensely
contributed to the improvement of this thesis paper.
The author is indebted to Dr. A.S.G. Faruque, Scientist,CSD and Md. Abdul Malek,
Data Manager,CSD of International Centre for Diarrhoeal Research, Bangladesh
(ICDDR,B), Dr Mizanur Rahman of Dhaka Shishu Hospital(DSH) for their enormous
support in providing necessary data. The author acknowledges the contributions of
members of DOE, BMD, DCC, SOB etc for their support in regard to various data.
The author acknowledges the sacrifice of his family members notably his wife, Papia
for all her assistance and encouragement.
Last but not the least, the author expresses his gratitude and appreciation to the
members of the Examination Board.

xx
ABSTRACT
Water plays a vital role to shape up the health quality of dwellers of Dhaka city.
Quite a large number of people are usually affected by waterborne diseases in each
year and various studies reveal that due to presence of high percentage of low-
income and slum communities in the capital, the high rates of diarrhoeal incidences
mostly come from these vulnerable communities who lack of adequate water,
sanitation and knowledge on personal hygiene. This study identifies the vulnerable
community composed of people (73%) mainly from other districts coming for
economic reason. A bimodal distribution of diarrhoeal incidences especially before
rainy season (March-May) and during rainy season (July-October) has been
observed from these communities.
It is seen that maximum number of HHs (65%) of vulnerable communities had their
supplied water of DWASA through private connections and the rest 35% had their
supplied water of DWASA through public connections. A high percentage of
diarrhoeal (74%), typhoid (60%) and eye infections (77%) incidences in case of
private connections were reported. Majority of vulnerable communities’ HHs (47%)
were having urban water supply options like “Hand pump connected to supply line”,
38% of HHs were having “Piped water supply without reservoir” and rest 15% HHs
were having “Piped water supply with reservoir”. So it was about 85% (47%+38%) of
the total HHs those were to rely on unsecured water supply. On the other hand,
95% of HHs never had their demand fulfilled out of which only 55% could mitigate
their daily need by just half of their demand. Only 5% showed their fulfillment of their
demand as per as water availability are concerned. Overall 68% of HHs did not boil
water for drinking purpose and slum do not boil water just for economic reason. The
slum community had more pit latrine system (64%) where low-income community
based on septic tank system (67%).83% of slum HHs did not use any media to
wash their hands following defecation, on the contrary 100% low-income HHs were
found very much aware about use of media (in this case soap).
Samples of water from WASA pumps showed the quality of water was quite
acceptable as per Bangladesh Standard but the water samples from user ends
showed high contamination of water with faecal coliform. It was observed that most
of the private connections (mainly slum community) were made with leaky pipes
drawn over the waste and wet lands. Moreover maximum water points were in very
close proximity to latrines or poorly maintained.
About 58%, 23% and 56% of HH members were suffering from diarrhoea, typhoid
and eye infections respectively. It was seen that male were more vulnerable to the
waterborne diseases than those of female. It was also seen that female children <5
years(10%) suffer from diarrhoea just double than male percentage (5%). Gender
differences could be one of the reasons.
Overall vulnerability of communities indicate that slum had higher combined
vulnerability scores for diarrhoea (CVSdiarrhoea = 5.86) and eye infections (CVSeye
infections = 6.67) than those of low-income community and overall vulnerability of
selected areas indicate that the slum and low-income communities of Gulshan area
are the most vulnerable, followed by the slum and low-income communities of
Tejgaon, Mirpur and Badda.

xxi
This study found that for each non-reported diarrhoea incidence remained on
average for 5.03 days with standard deviation of 2.02 days. The direct, indirect and
total costs were Tk. 759, Tk. 762 and Tk. 1522 respectively. Again each typhoid
incidence remained on average for 17.4 days with standard deviation of 7.2 days.
The direct, indirect and total costs were about Tk. 3621, Tk. 1361 and Tk. 4982.68
respectively. Finally eye infections’ incidence remains on average for 6.3 days with
standard deviation of 1.5 days. The direct, indirect and total costs were Tk. 205, Tk.
712 and Tk. 917 respectively. The total cost of diseases for selected areas for one
year could be from 87,138,383 Tk. to 149,892,036 Tk. and for slum areas of whole
Dhaka city is 5,653,819,098Tk. or 81,726,209 USD. This huge amount of money
is generally expended by these groups and might remain unnoticed or not
considered during city planning or any national development plan.
The prevalence rate (PR) reveals that vulnerable people are more susceptible to the
diarrhoea (PRdiarrhoea = 480.95) than those of eye infections PReye infections = 309.52
and typhoid (PRtyphoid = 47.62).
This study identifies an exponential correlation between numbers of diarrhoea
incidences of reporting cases with temperature of Dhaka city. Moreover it also has
identified a negative correlation between the demands of water with the number of
non-reporting diarrhoea incidences.

1
CHAPTER 1
INTRODUCTION
1.1. General
Water is one of the five essentials (air, water, food, heat and light) for the human
beings, without which life cannot be sustained for longer period. Over 70% of the
earth's surface is water. However, most of it i.e. 98% is salt water and only 2% of
the earth's water is fresh water that we can drink. Water is the basis of all life forms
even including our body. Our muscles that move our body are 75% water; our blood
that transports nutrients is 82% water; our lungs that provide oxygen are 90% water;
our brain that is the control center of our body is 76% water; even our bones are
25% water (Batmanghelidj, 2008). It is undoubtedly the most precious natural
resource that exists on our planet without this seemingly invaluable compound, life
on earth would not be in existence. It is essential for everything on our planet to
grow and prosper. Although we as human recognize this fact but we disregard it by
polluting our lakes, rivers and oceans by throwing industrial effluents, municipal
waste, agricultural waste, sewage disposal, etc. Subsequently, we are slowly but
surely harming our planet to the point of no return! As we understand that our health
is truly dependent on the quality and quantity of the water we drink. Hence any
deficiency either of it is going to have a negative effect on our health. That is why
safe, adequate and accessible supplies of water, combined with proper sanitation,
are basic needs and essential components of primary health care. The larger the
quantity and the better the quality of water, the more rapid and extensive is the
advancement of the public health (Ahmed and Rahman, 2000). Pollution of
freshwater (drinking water) is a problem for about half of the world's population.
Each year there are about 250 million cases of water-related diseases, with roughly
5 to 10 million deaths (GP, 2005). Contaminated water - contaminated by feces, not
chemicals - remains one of the biggest killers worldwide. According to one recent
estimate, lack of adequate water, sanitation and hygiene is responsible for an
estimated 7 percent of all deaths and disease globally. Diarrhoea alone claims the
lives of some 2.5 million children a year (Murray and Alan, 1996). It has been noted
that the Asian rivers are the most polluted in the world. They have three times as
many bacteria from human waste as the global average and 20 times more lead
than rivers in industrialized countries (GP, 2005). On the contrary Bangladesh has
some of the most polluted groundwater in the world. In this case, the contaminant is

2
arsenic, which occurs naturally in the sediments. Around 85% of the total area of the
country has contaminated groundwater, with at least 1.2 million Bangladeshis
exposed to arsenic poisoning and with millions more at risk (GP, 2005). In
Bangladesh, drinking water supplies, both in urban and rural areas are often found
to contain contaminants (ITN-BUET, 2004). Access to safe drinking-water is
essential to health. It has been seen that investments in water supply and sanitation
can yield a net economic benefit, since the reductions in adverse health effects and
health care costs outweigh the costs of undertaking the interventions. Experience
has also shown that interventions in improving access to safe water favor the poor
in particular, whether in rural or urban areas and can be an effective part of poverty
alleviation strategies.
Dhaka is the capital of Bangladesh. Rapid urbanization and population growth in last
decades have changed the physical environment of Dhaka. Population of Dhaka
metropolitan area has been estimated to be 12 million and the city has grown at a
rate of 4.5 sq. km per year in the recent past (Mahmood, 2008). A recent media
report says that there are about 38% of total population of Dhaka is living in slum
areas. Again homelessness and poverty are international crisis where Bangladesh
is not an exception to this. It is being one of the poorest countries in the world; with
an estimated 3.4 million people live in some 5000 slums of its capital city, Dhaka
(Islam, 2005). But interestingly most of the time, it is the low-income groups and
people of slums are human capital greatly contributing to the economy and work
force of the capital city. The majority of them migrated to Dhaka for economic
reasons (Tiina et al., 2002), but unfortunately these peoples suffer unacceptable
levels of malnutrition, hygiene and health, deprived of essential health services,
financial stability, education and security. Dhaka has become one of the dirtiest city
of the world (Tiffany, 2008). Like other environmental factors water plays a vital role
to shape up the health quality of dwellers of Dhaka city. Quite a large number of
people is usually affected by waterborne diseases in each year and most of them
are from vulnerable groups.
1.2. Rationale of the Study
It is estimated that 88% of diarrhoeal disease is caused by unsafe water supply and
inadequate sanitation and hygiene (WHO, 2004). Lack of access to safe and
adequate water supplies contributes to ongoing poverty both through the economic

3
costs of poor health and in the high proportion of household expenditure on water
supplies in many poor communities, arising from the need to purchase water and/or
time and energy expended in collection. Access to water services forms a key
component in the UNDP Human Poverty Index for developing countries
(UNDP, 1999). Access to safe drinking water has been an important national goal in
Bangladesh. As per the WHO report, Bangladesh has already attained 97% total
water coverage and 53% total sanitation coverage with 99% urban water coverage
and 82% urban sanitation coverage during 2000 (WHO/UNICEF, 2000).
While Bangladesh has almost achieved accepted bacteriological drinking water
standards for water supply, high rates of diarrhoeal disease morbidity indicate that
pathogen transmission continues through water supply chain (and other modes)
(Hoque et al., 2006). In case of Dhaka, various studies reveal that due to presence
of high percentage of low-income and slum communities in the capital, these high
rates of diarrhoeal incidences mostly come from these vulnerable communities who
lack of adequate water, sanitation and knowledge on personal hygiene. Though it is
well understood that the adequacy of water and accessibility to those
services/facilities rest on Dhaka Water Supply and Sewerage Authority (DWASA)
who is principally responsible for the provision, operation and maintenance of water
supply, sanitation and storm water disposal services to the population of Dhaka city
as stipulated in the Water Supply and Sewerage Authority Act, 1996. But today it is
facing various challenges both for quantity and quality of supply and heading for
awkward situation due to the unplanned population growth.
To understand the exact cause of major waterborne diseases morbidity of
vulnerable communities of Dhaka city, this study has examined the quality of water
supplied by urban water supply system and information on waterborne diseases the
vulnerable communities generally suffer round the year. Both the information has
been synthesized to relate health impacts in terms of diseases‟ incidences to water
pollution, poor sanitation and bad hygiene practices. Besides, an evaluation has
also been made to quantify these economic valuations of health effects. Additionally
an attempt has been made to correlate the climatic factors with the number of
waterborne diseases‟ incidences of the selected areas of Dhaka city so as to help
decision makers aware about consequent actions to be taken. Hence this research
will provide appropriate technological and management tools to the urban planners,

4
environmentalists and policy makers to formulate control strategy to preserve water
environment of Dhaka city and take appropriate measures to minimize health
hazards on the most vulnerable group exposed to the water pollution.
1.3. Objectives of the Study
The main objectives of the study are:
 Qualitative assessment of water of urban water supply system, sanitation
and hygiene practices of different vulnerable communities of the most
affected areas of Dhaka city as per as waterborne diseases are concerned.
 Quantitative assessment of impacts on human health due to water pollution,
sanitation and hygiene practices and economic losses incurred for the
vulnerable communities of Dhaka city.
 Evaluation of prevalence rate of specific waterborne diseases due to water
pollution, sanitation and hygiene practices by the population under
observation.
 Identification of correlation between selected climatic factors and the worst
waterborne disease‟s incidence of the same selected areas of Dhaka city.
1.4. Scope of the Study
This thesis will focus on how vulnerable communities of selected administrative
areas of Dhaka city are being affected due to poor water quality, inadequate
sanitation and hygiene practices of an individual over a period of time and find out
any probability of correlation of selected climatic factors like rainfall, temperature
and humidity on the diarrhoeal incidences of the population under observation. To
carryout comprehensive study comprising all of the above features and facts require
a considerable amount of time, accessibility, economic and human resources. To
materialize those, “Convenience Sampling Method” was carried out in order to find
out the result. Though this method is non-statistical and also assumes a
homogeneous population which was not true in the practical sense. However it still
provides useful information regarding the population under observation. To augment
the thesis, apart from primary data, a substantial amount of data had also been
taken from secondary and tertiary sources. Again due to time and resource

5
constrain, identification of the most affected areas of Dhaka city as per as
waterborne diseases were concerned would be done from the data collected from
the authenticated secondary sources like International Centre for Diarrhoeal
Disease Research, Bangladesh (ICDDR,B), Dhaka Shishu Hospital(DSH) etc. Here
the four most affected areas have been selected out of twenty one administrative
areas/thanas of earlier setup. Again this paper will assume the low-income and
slums as the vulnerable community affected by desired factors. Efforts will be made
to collect all the relevant information from those areas by conducting questionnaire
survey, sanitary inspection and sample collections. In this regard, “Slums of Dhaka
Metropolitan Area” Map developed by Centre for Urban Studies (CUS) will also be
used as tertiary source in order to pin-point the areas to be explored. Since it has
also been planned to identify the correlation between waterborne diseases‟
incidences of those selected areas and climatic factors prevailing in Dhaka city.
Hence relevant and updated information on climate of Dhaka will also be collected
from Bangladesh Meteorological Department (BMD).
1.5. Limitations of the Study
This study might have following limitations:
 Due to non-availability of data on new thanas from the secondary sources,
study areas have been selected based on data of earlier setup i.e. twenty
one administrative thanas of Dhaka city.
 In the questionnaire survey, the respondents were found not to maintain any
kind of records at their personal level hence the information provided by
them were more or less from their memories only. They often avoid giving
out their confidential information (e.g. sanitation habit, salary etc.) too.
 Since the family members of the households also have food at different
places away from houses; hence it will be difficult to pin point the problem
related with waterborne diseases only.
 In questionnaire survey, the most of the respondents had confusions in
identifying cholera, diarrhoea and dysentery diseases and hence all three
have been considered as one i.e. diarrhoea.
 Due to paucity of time, limited economic and as well as human resources,
Convenience Sampling Method has been conducted. Moreover it is a non-
probability sampling method and hence statistically is not significant.

6
1.6. Organization of the Thesis
This report presents the analysis, results and findings of the study in six chapters as
shown below:
Chapter 1: Introduction: This chapter contains the general background and present
status of the problem, objectives of the study, scopes of the study and the thesis
organization.
Chapter 2: Literature Review: Compiles all relevant literatures on health impacts
due to lack of adequate water, sanitation, and hygiene practices and climatic
factors.
Chapter 3: Methodologies: It describes the methodologies for this thesis starting
with selection of study areas to the display of information on the thematic map using
GIS, different statistical tools used etc.
Chapter 4: Analysis of Data: Here it provides a description of the analysis process
adopted in this study.
Chapter 5: Results and Discussions: Presents the results of the analysis
accompanied by discussions.
Chapter 6: Conclusions and Recommendations: Summarizes the whole study
and provides some guidelines for further research in this area.

7
CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
Safe, adequate and accessible supplies of water, combined with proper sanitation,
are basic needs and essential components of primary health care. While man has
always recognized the importance of water for internal bodily needs, his recognition
of its importance to health is a more recent development, dating back only about a
century. Health problems related to the inadequacy of water supplies are universal
but generally of greater magnitude and significance in developing countries. While
population under water supply coverage improved significantly during the Water
Supply and Sanitation Decade and after the decade, it has been estimated about
25% of the population in developing countries still does not have access to safe
water (Ahmed and Rahman, 2000). Presently pollution of freshwater (drinking water)
is a problem for about half of the world's population. Each year there are about 250
million cases of water-related diseases, with roughly 5 to 10 million deaths
(GP, 2005). Water pollution causes number of waterborne diseases like diarrhoea,
cholera, typhoid, hepatitis etc.
There has been an extensive debate about the relative importance of water quantity,
water quality, sanitation and hygiene in protecting and improving health (Esrey et
al., 1985; Cairncross, 1990; Esrey et al., 1991). In this regard, children bear the
greatest health burden associated with poor water and sanitation. Diarrhoeal
diseases attributed to poor water supply, sanitation and hygiene account for 1.73
million deaths each year and contribute over 54 million Disability Adjusted Life
Years (DALY), a total equivalent to 3.7% of the global burden of disease (WHO,
2002). This places diarrhoeal disease due to unsafe water, sanitation and hygiene
as the 6th
highest burden of disease on a global scale, a health burden that is largely
preventable (WHO, 2002). Other diseases are related to poor water, sanitation and
hygiene such as trachoma, schistosomiasis, ascariasis, trichuriasis, hookworm
disease, malaria and Japanese encephalitis and contribute to an additional burden
of disease. As of 2000 it was estimated that one-sixth of humanity (1.1 billion
people) lacked access to any form of improved water supply within 1 kilometre of
their home (WHO/UNICEF, 2000).

8
In this study, an attempt has been made to assess the health impacts on the most
vulnerable communities of Dhaka city due to limitations in access to adequate pure
water supplied by urban water supply system, sanitation and lack of adequate
knowledge on personal hygiene.
2.2 The Vulnerable Community
2.2.1 Definition
A Community consists of a group of people with common but also conflicting
interests and ideas and different socio-economic and cultural backgrounds
(Ahmed and Rahman, 2000). The identity of the people in the community is shaped
by their history and their socio-economic and environmental conditions. When the
basic services like water supply, improved sanitation, better hygiene education etc.
of a community are less or sometimes even absent- the members of that community
are likely to be vulnerable to various diseases associated with the particular issue.
2.2.2 Considerations
In this study, two socio-economic settings i.e. slum and low-income communities of
selected areas of Dhaka city have been considered:
(a) Slum: CUS (2006) has defined a slum as a neighborhood or residential
area with a minimum of 10 households or a mess unit with at least 25 members with
four of the following five conditions prevailing within it:
 Predominantly poor housing.
 Very high population density and room crowding.
 Very poor environmental services, particularly water and sanitation facilities.
 Very low socioeconomic status for the majority of residents. The key
indicator of this is Tk. 5000 per HH income per month based on the urban
poverty line per capita income estimates (Huque, 2008).
 Lack of security of tenure.

9
(b) Low-income: A low-income community resides in compact settlements like
tin-shed or tin-roofing with brick walls etc. which generally grow in a cluster on
government and private vacant land having distinct service facilities offered by land
owner and having better socioeconomic condition (above upper poverty line) than
slum as stated by Huque (2008).
2.2.3 Estimation of Population of a Community
In order to analyze the health impacts of a given population of an area, there is a
requirement to calculate the population of that area. Estimation of population of a
community depends on the latest census data of that community. It is customary to
estimate the population of a community between two census periods based on last
census data by applying some conventional methods. In this study, the most widely
used Geometric Progression Method (Ahmed and Rahman, 2000) has been used to
estimate the population of administrative thanas of Dhaka city for the year of 2010
using the population data of 2001 as given in the Table E.1 of Appendix E.
Pf = Pp (1+r)n
(2.1)
Where Pf = future population, Pp = present population; r = rate of yearly population
growth and n = number of years to be considered.
2.2.4 Performance of Community Drinking-Water System
If the performance of a community drinking-water system is to be properly
evaluated, a number of factors must be considered. WHO (2008) suggests for usual
practice to include the critical parameters for microbial quality (normally E. coli,
chlorine, turbidity and pH) and for a sanitary inspection to be carried out. In this
thesis, all these factors (Faecal Coliform instead of E. coli ) have been considered in
order to assess water quality of the urban water supply options.
2.3 Water Pollution and Related Issues
2.3.1 Water Pollution
Water pollution occurs when a body of water is adversely affected due to the
addition of large amounts of materials or chemicals to the water in such a way that it
becomes unfit for its intended use. Water pollution is developed by the release of
waste products and contaminants into surface runoff, into river drainage systems,

10
leaching into groundwater, liquid spills, wastewater discharges, eutrophication and
littering.
2.3.2 Types of Pollutants, Sources and Effects
(a) Types of pollutants based on sources: Two types of water pollutants exist:
 Point Sources: It occurs when harmful substances are emitted directly into a
body of water. The industries located at Hazaribagh are the best illustrates
point sources water pollution.
 Non-point Source: It delivers pollutants indirectly through environmental
changes. Non-point sources are much more difficult to control. Pollution
arising from non-point sources accounts for a majority of the contaminants
in streams and lakes.
(b) Major sources: The major sources of water pollution can be classified as:
 Municipal: Municipal water pollution consists of waste water from homes
and commercial establishments.
 Industrial: These contaminants include liquid discharges from spent water of
different industrial processes such as manufacturing and food processing.
 Agricultural: Agriculture including commercial livestock and poultry farming
is the source of many organic and inorganic pollutants in surface waters and
groundwater.
(c) Causes: There are many causes as identified by DOE for which the Dhaka
city water bodies get polluted everyday (DOE, 2006):
 Untreated Sewage Disposal: The existing sewage treatment plant treats
only 40,000 to 50,000 m3
of sewage while the city generates about 1.3
million m3
. Most of the rest directly or indirectly reach the surrounding rivers.
The Table 2.1 shows the concentration of heavy metals above the
Environmental Quality Standard (EQS) in the surrounding rivers of Dhaka
city.

11
Table 2.1: Heavy metal concentration in river water of Dhaka city
Sample ID
Concentration in mg/l
Al Cd Cr Pb Hg Se Zn
Buriganga River Friendship Bridge 3.27 0.014 0.036 ND
1
0.0021 0.001 0.56
Turag River:Amin Bazar 11.884 0.018 0.11 0.394 0.0058 0.0002 1.002
Buriganga River Chandni Ghat 5.396 0.006 0.006 0.25 0.0016 ND 0.984
Lakhya River: Sayedabad WTP
Intake point
2.952 0.006 0.028 0.074 0.0032 0.0005 0.246
Balu River Zirani Khal 2.1166 0.006 0.0224 ND 0.0010 ND 1.122
EQS(Drinking water) 0.2 0.005 0.05 0.05 0.001 0.01 5.0
 Municipal waste disposal: It is often disposed off into city water bodies. Less
than 50% of generated municipal waste is disposed in the landfill site and a
significant part of the remaining waste goes into the water bodies.
 Disposal from water transport vehicles: Disposal of waste, wastewater and
petroleum products from water transport vehicles further pollute the river
water.
 Agricultural activities and unsanitary practices: These are like defecating in
the water bodies lead to the contamination of nearby water bodies. The
Table 2.2 shown here is the state of water quality of lake water of Dhaka
city:
Table 2.2: Concentration of water quality indicators of lake water of Dhaka city
Name of the Lake
pH BOD
(mg/l)
DO
(mg/l)
TS
(mg/l)
Coliforms
(cfu/100ml)
Dhanmondi lake
(near Russell Square)
6.95 1.9 6.1 168 600
Gulshan-Baridhara lake
(Near Road No.11 )
7.10 35 0.5 302 1200
Sitadel Lake (East Side ) 6.91 2.6 6.6 92 500
Ramna Lake
(beside Ramna Chinese Restaurant)
6.52 25 1.3 87 700
Crescent Lake (East side ) 5.9 2.1 8.3 98 900
EQS2
6.5-8.5 ≤ 3 5 ≥ ≤ 200
Source: DOE (2006)
1
Not detectable
2
Environmental Quality Standard (EQS) of lake water (used as recreation purposes). Five
days BOD at 20
0
C; Coliforms in cfu/100 ml/ (24 hours incubation at 35
0
C).
Source: DOE (2006)

12
 Unplanned development and encroachment of water bodies: Unplanned
development and encroachment make the water bodies narrower/shorter
and lesser in depth resulting in over flooding the area with polluted water.
(d) Effects of water pollution: Water, sanitation and hygiene have important
impacts on both health and disease. Contamination of food, hands, utensils and
clothing can also play a role, particularly when domestic sanitation and hygiene are
poor. The WHO has made a fact sheet of over 20 water-related-diseases out of
which Cholera, Diarrhoea, Scabies, Schistosomiasis, Trachoma/ eye infections,
Typhoid and Paratyphoid are noteworthy for Dhaka city dwellers.
 Cholera: Cholera outbreaks generally occur in any part of the city where
water supplies, sanitation, food safety and hygiene practices are
inadequate. Overcrowded communities like slum areas and other low cost
residential areas with poor sanitation and unsafe drinking-water supplies are
most frequently affected.
 Diarrhoea: Water contaminated with human faeces for example from
municipal sewage, septic tanks and latrines is of special concern. Animal
faeces also contain microorganisms that can cause diarrhoea. This
happens to be a regular phenomenon in Dhaka city right after any flood
episode.
 Scabies: Scabies is a contagious skin infection that spreads rapidly in
crowded conditions and is very much available in the slums. Personal
hygiene is an important preventive measure and access to adequate water
supply is important in control.
 Trachoma: It is an infection of the eyes that may result in blindness after
repeated re-infections. It is the world's leading cause of preventable
blindness and occurs where people live in overcrowded conditions with
limited access to water and health care. Trachoma spreads easily from
person to person and is frequently passed from child to child and from child
to mother within the family.

13
 Typhoid and Paratyphoid Enteric Fevers: Typhoid and paratyphoid fevers
are infections caused by bacteria which are transmitted from faeces to
ingestion.
2.3.3 Background Level of Immunity
The effects of exposure to pathogens are not the same for all individuals or, as a
consequence, for all populations. Repeated exposure to a pathogen may be
associated with a lower probability or severity of illness because of the effects of
acquired immunity. For some pathogens (e.g., HAV), immunity is lifelong, whereas
for others (e.g., Campylobacter), the protective effects may be restricted to a few
months to years. On the other hand, sensitive subgroups (e.g., the young, the
elderly, pregnant women and the immuno-compromised) in the population may have
a greater probability of illness or the illness may be more severe, including mortality.
2.4 Water Quality and Standards
2.4.1 Water Quality
Since the quality of water is affected by both man and natural activities, hence pure
water is not available in nature and however nor it is desirable for water supply.
Some of the water quality parameters respond to human senses of sight (turbidity,
color), taste (salty, offensive) and smell (odour) but the presence of pathogens and
poisons in drinking water cannot be identified by human senses. The most important
parameter of drinking water quality is the bacteriological quality, i.e. presence of
pathogenic organisms. The water borne diseases are caused by the ingestion of
pathogens with drinking water. Control of the most water-borne diseases is hinged
upon availability of enough water for domestic and personal cleanliness or sound
hygiene practices. The water-borne diseases can therefore also be described as
water-washed diseases.
2.4.2 Water Quality Standards
Water for public water supplies should be drawn from the best available source for
cost-effective treatment of water. The degree and method of treatment to make
water potable and attractive to the consumers depend on the characteristics of the
raw water. Table 2.4 shows the recommended water quality standards for surface
water sources for development of water supply in Bangladesh.

14
Table 2.4: Bangladesh water quality standards for surface water for water
supply.
Water Quality
Parameters
Unit
Values for Water Supply by
Disinfection only
Conventional
Treatment
pH - 6.5 – 8.5 6.5 – 8.5
BOD mg/l ≤ 2 ≤ 3
DO mg/l ≥ 6 ≥ 6
Total Coliform cfu/ 100 ml ≤ 50 ≤ 5,000
Source: Ahmed and Rahman (2000)
However the list of parameters presented in this table is not comprehensive; it
provides a general guideline for selection of a source for water supply. Bangladesh
developed the first water quality standards in 1976 based on the WHO 1971
International Drinking Water Standards. The Ministry of Environment and Forests,
Government of Bangladesh adopted comprehensive water quality standards for
drinking water by Gazette notification in 1997 as Environmental Conservation Rules
under the Environmental Conservation Act, 1995. Part of the Bangladesh Drinking
Water Standards, 1997 with WHO guideline values, 2004 are presented in Table
2.5.
Table 2.5: Bangladesh standard for drinking water
Aspects Parameters
Bangladesh,
ECR 1997,
Schedule 3(B)
WHO guideline
values, 2004
Physical pH 6.5-8.5 -
TDS (mg/l) 1000 1000
Color (Hazen Unit) 15 15
Turbidity (NTU) 10 5
Odor Odorless Odorless
Chemical Hardness (as CaCO3) (mg/l) 200-500 -
Chlorine (Residual) (mg/l) 0.2 0.2
Nitrate (NO3) (mg/l) 10 50
Ammonia (mg/l) 0.5 1.5
Iron (mg/l) 0.3-1.0 0.3
Arsenic (mg/l) 0.05 0.05
Microbial TTC (cfu/ 100 ml) 0 0
Faecal Coliform (cfu/ 100 ml) 0 0
E.coli (cfu/ 100 ml) 0 0
Source: Ahmed and Rahman (2000)

15
2.5 Water Supply
2.5.1 Objectives of Water Supply
The broad objectives of any water supply system are:
 Supply water in adequate quantity: means that the water supplied to the
community should meet all the requirements for water and be available when
required.
 Supply safe and wholesome water to the consumers: Here water is safe
when it does not cause any harm upon consumption. Whereas the wholesome
water is unpolluted, significantly free from toxic substances as well as excessive
amounts of mineral and organic matters that may impair its quality.
 Make water easily available to consumers: that the water is accessible and
within easy reach of the consumers so as to encourage the use of adequate
water for personal and household cleanliness.
2.5.2 Pattern of Urban Water Supply for Vulnerable Group
Pattern of Urban water supply pattern for vulnerable communities of Dhaka city was
found broadly in two types:
(a) Community Type DWASA Supply: These have some different patterns:
 Simple house connection where all communities collect water.
 Flexible pipe carrying water from nearest legal water point by illegal method.
 Hand pump fitted with WASA main line and
 Conventional public stand post with platform and drains. Some of them have
a reservoir to temporarily store water during non-supply hours.
(b) Shallow Tubewell (STW): Most of the time, these are installed by various
NGOs. However, during the field survey it was found that there were some slum
people who borrow water from nearby middle class community having reservoirs of
their own too.

16
2.6 Domestic Water Supply
2.6.1 Domestic Water and Its Usage
As per WHO‟s guidelines for drinking-water quality, domestic water has been
defined as being 'water used for all usual domestic purposes including consumption,
bathing and food preparation' (WHO, 2008). White et al. (1972) suggested that three
types of use could be defined in relation to normal domestic supply:
 Consumption (drinking and cooking)
 Hygiene (including basic needs for personal and domestic cleanliness)
 Amenity use (for instance car washing, lawn watering).
Thompson et al. (2001) suggest a fourth category can be included of 'productive
use' which was of particular relevance to poor households in developing countries.
Productive use of water includes uses such as brewing, animal watering,
construction and small-scale horticulture. The first two categories identified by White
et al. (1972) i.e. „consumption‟ and „hygiene‟ have direct consequences for health
both in relation to physiological needs and in the control of diverse infectious and
non-infectious water-related disease. The third category- „amenity‟ may not directly
affect health in many circumstances. Productive water may be critical among the
urban poor in sustaining livelihoods and avoiding poverty and therefore has
considerable indirect influence on human health (Fass, 1993; Thompson et al.,
2001).
(a) Consumption: Water is a basic nutrient of the human body and is
critical to human life. It supports the digestion of food, adsorption, transportation and
use of nutrients and the elimination of toxins and wastes from the body (Kleiner,
1999). The per capita water consumption is greatly influenced by various factors.
Some major factors can be cited below:
 Population Distribution
 Climatic Conditions
 Quality of Water
 Pressure of Water

17
 Water Rates and Metering
 Nature of Supply
 Water Source Distance
 Availability of an Alternative Source
 Sanitation
The volume of water required for hydration for the most vulnerable in tropical
climates as given in the Table 2.6 and higher in conditions of raised temperature
and/or excessive physical activity.
Table 2.6: Volumes of water required for hydration for the most vulnerable in
tropical climates
Individual
Type
Volumes (litres/day)
Average
conditions
Manual labour in
high temperatures
Total needs in
pregnancy/lactation
Female adults 2.2 4.5 4.8 (pregnancy)
5.5 (lactation)
Male adults 2.9 4.5 -
Children l.0 4.5 -
Source: Howard and Bartram (2003)
(b) Hygiene: The need for domestic water supplies for basic health
protection exceeds the minimum required for consumption (drinking and cooking).
Additional volumes are required for maintaining food and personal hygiene through
hand and food washing, bathing and laundry. Poor hygiene may in part be caused
by a lack of sufficient quantity of domestic water supply (Cairncross and Feachem,
1993). The diseases linked to poor hygiene include diarrhoeal and other diseases
transmitted through the faecal-oral route; skin and eye diseases, in particular
trachoma and diseases related to infestations, for instance louse and tick-borne
typhus (Bradley, 1977; Cairncross and Feachem, 1993).
2.6.2 The Links Between Water Supply, Hygiene and Disease
An effective way to inform decision-making is to categorize pathogens /diseases in
relation to the broad mode of transmission. Bradley (1977) suggests that there are
four principal categories that relate to water and which are not mutually exclusive:

18
 Water-borne caused through consumption of contaminated water (for
instance diarrhoeal diseases, infectious hepatitis, typhoid, guinea worm).
 Water-washed caused through the use of inadequate volumes for
personal hygiene (for instance diarrhoeal disease, infectious hepatitis,
typhoid, trachoma, skin and eye infections).
 Water-based- Here an intermediate aquatic host is required (for instance
guinea worm, schistosomiasis).
 Water-related vector spread through insect vectors associated with water
(for instance malaria, dengue fever).
While a full analysis of improved water and sanitation services would consider
pathogens passed via all these routes, the present study focuses on water-borne
and water-washed diseases. This is partly because, at the household level, it is the
transmission of these diseases that is most closely associated with inadequate
water supply, poor sanitation and lack of hygiene. Moreover, water-borne and water-
washed diseases are responsible for the greatest proportion of the direct-effect
water and sanitation-related disease burden.
2.7 Sanitation
2.7.1 Definition and Objectives of Sanitation
The word sanitation actually refers to all conditions that affect health and according
to WHO may include things as food sanitation, rainwater drainage, solid waste
disposal and atmospheric pollution (Ahmed and Rahman, 2000). The principal
objectives of providing sanitation facilities are:
 To have improved public health
 To minimize environmental pollution
Sanitation can contribute greatly to preventing the spread of infectious diseases
through transmission of disease causing agents as is the case when pathogenic
organisms from the excreta of an infected person are transmitted to a healthy
person as can be seen in Figure 2.1. It is important to understand that the
improvement of health is not possible without sanitary disposal of human excreta.
However, neither sanitation nor water supply alone is good enough for health

19
improvement. It is now well established that health education or hygiene promotion
must accompany sufficient quantities of safe water and sanitary disposal of excreta
to ensure the control of water and sanitation related diseases. This interrelationship
was shown by Veenstra, (1994) during his lecture on urban sanitation as shown in
the Figure 2.2.
2.7.2 Relationships Between Water, Sanitation, Hygiene and Diarrhoea
Diseases primarily transmitted through the faecal-oral route (Figure 2.1) include
infectious diarrhoea, typhoid, cholera and infectious hepatitis. Transmission may
occur through a variety of mechanisms, including consumption of contaminated
water and food as well as through person-person contact (Bradley, 1977). These
are dealt with together here, in order to emphasize the importance of local disease
patterns rather than applying generic models. The available evidence from health
studies suggests that interventions are likely to be locality-specific and are
determined by timing and the interaction between different factors.
Figure 2.1 Disease transmissions and sanitation (Ahmed and Rahman, 2000)
Excreta
Water
Hands
Insects
Soil
New
Host
Milk
Vegetable
Food
SanitationFacilities
Personal Hygiene
Foot wear
Sanitary Latrines
Food Sanitation TW/Water Treatment
Legend

20
Other factors apart from water and sanitation facilities and hygiene behaviors may
significantly influence diarrhoeal disease. For example breast-feeding has been
noted in several studies as being protective against diarrhoeal disease
independently of other interventions (Al-Ali et al., 1997; Vanderslice and Briscoe,
1995).
The timing of hand washing may be important. Experience suggests that the most
critical times are following defecation and before eating. Curtis et al. (2000) suggest
that the critical time is post-defecation rather than before eating, while other studies
suggest that the reverse is true in some situations (Birmingham et al., 1997).
Stanton and Clemens (1987) found reduction in diarrhoea incidence among young
children was influenced by maternal hand washing prior to food preparation. A
number of studies suggest that hand washing with soap is the critical component of
this behavior and that hand washing only with water provides little or no benefit.
Hoque et al. (1995) found that use of mud, ash and soap all achieved the same
level of cleanliness with hand washing and suggested that it is the action of rubbing
of hands that was more important than the agent used.
Health Education
Or
Hygiene Promotion
Sanitation
Improvement
of
Health
Water
Supply
Figure 2.2 Interrelationship between water, sanitation and health education
(Veenstra, 1994)

21
2.7.3 Relationships Between Water, Hygiene and Other Infectious Diseases
Infectious diseases of the skin (a sub-set of water-washed diseases) and trachoma
are amongst the diseases on which water quantity would be expected to exert
significant influence. Trachoma is the most extensively studied disease, given its
relatively high impact on health. One study in southern Morocco that showed a
difference in incidence in trachoma between the use of less than 5 litres per day and
use of more than 10 litres per day. Prüss and Mariotti (2000) also note six studies
that showed a positive relationship between increased access to water and reduced
incidence of trachoma, with a median reduction of 27%, with a range of 11-83%
reduction. In most studies, distance from primary water source to home appears to
be the most significant water supply factor influencing trachoma.
2.7.4 Quantity and Accessibility
The WHO/UNICEF Joint Monitoring Programme has described reasonable access
as being 'the availability of at least 20 litres per person per day from a source within
one kilometre of the users dwelling' (WHO/UNICEF, 2000). However, it should be
noted that this definition relates to primarily to access and should not necessarily be
taken as evidence that 20 litres per capita per day is a recommended quantity of
water for domestic use. It is evident that increased accessibility equates to
increased volumes of water used (Esrey et al., 1991). Reviewing several studies on
water use and collection behavior, that there is a clearly defined general response of
water volumes used by households to accessibility, shown in Figure 2.3. Once the
time taken to collect water source exceeds a few minutes (typically around 5
minutes or 100m from the house), the quantities of water collected decrease
significantly. This graph contains a well-defined „plateau‟ of consumption that
appears to operate within boundaries defined by distances equivalent to around 100
to 1000m or 5 to 30 minutes collection time. There is little change in quantity of
water collected within these boundaries (Cairncross and Feachem, 1993). Beyond
distance of one kilometre or more than 30 minutes total collection time, quantities of
water will be expected to further decrease, in rural areas to a bare minimum where
only consumption needs can be met. In urban areas, where water supplies may be
close but total collection times are very high, greater volumes may be collected that
will support hygiene, although the overall impact on household poverty is significant
(Aiga and Umenai, 2002).

22
Figure 2.3: Graph of travel time (in minutes) versus consumption (WELL,1998)
As noted by WELL (1998), the first priority is to ensure that households reach the
plateau (Figure 2.3), that is to have access to an improved water source within one
kilometre, which corresponds to the current definition of reasonable access used in
assessing progress in global coverage with water supply and sanitation
(WHO/UNICEF, 2000). Beyond this, unless water is provided at a household level,
no significant changes in water quantities collected will be noted.
2.7.5 Hazards of Water Supply
From the generic flow chart of both urban water supply system and domestic water
supply system as given Figure 2.4, it can be seen that there could be number of
steps involved in exposure of pathogens to the community. The following steps
demonstrate such pathways of pathogens from sewage to consumers
(Azam, 2005):
 Pathogen concentration in fresh sewage.
 Mixing of sewage with drinking water through leakages, especially during low
pressure condition or interruption of supply in case of intermittent supply.
 Transportation of pathogens, survival in water against the residual chlorine
level.
 Addition of extra pathogens at supply end due to unsanitary condition and
unhygienic practices.
 Pathogen concentration in water sources at the point of consumption.
Return trip travel time
WaterConsumption(lpcd)

23
Figure 2.4: Generic flow diagram of water supply system
Volume of un-boiled water consumed by the population, including person-to person
variation in consumption behaviour and especially consumption behaviour of at-risk
groups. Hence a kind of precaution is always taken at domestic level in terms of
treatment (boiling of water, using disinfection tablets etc.) in order to avoid such
contamination.
2.8 Dhaka and Its Water Supply System
2.8.1 Growth of Dhaka
Dhaka is the capital of Bangladesh. The present population of Dhaka city is now
about 12 million and the projected population by 2025 is about 22 million. It is now
the 7th largest city in the world and by 2020 it will be the 2nd largest city in the world
(Paul, 2009). Actually this particular city passes through various era namely pre-
Ground Water (GW) Surface Water (SW)
GW Extraction Abstraction of SW
Treatment
Disinfection
Storage
Distribution
Collection
Treatment
Storage
Usage
Consumption (drinking and cooking)
Hygiene (including basic needs for personal and domestic cleanliness)
Productive use (brewing, animal watering, construction and small-scale
horticulture.)
Amenity use (for instance car washing, lawn watering).
Urban Water
Supply System
Domestic Water
Supply System

24
Mughol Era (before 1608), Mughol Era (after 1608 to 1757), under The East India
Company (1757-1858), under the British (1858-1947), as provincial capital of East
Pakistan (1947-1971) and lastly as capital of independent Bangladesh. During these
times the demographic layout of Dhaka city changed in many folds along with its
population. After the independence of Bangladesh, the urbanization activities have
been achieving tremendous growth for the needs of the newly independent
country‟s capital. The city began to expand in all directions.
On the other hand this Metropolitan City with 360 sq. km has to bear 9.3 million
people with about 6% population growth (DCC, 2009) as estimated by DCC. A water
supply Master plan for the Dhaka city was prepared in 1992 for an area of about 360
sq. km, which has now become redundant as the prediction on population and water
demand has been surpassed by huge margin (Al-Mamoon, 2006). According to the
research conducted by Population Science Division of Dhaka University, in every
year, about 7 lacs and 80 thousands of people are newly added to the existing
trends. Unfortunately the other utility services could hardly keep the pace with this
population growth. As a result environmental degradation has taken place.
2.8.2 Dhaka Water Supply and Sewerage Authority (DWASA)
(a) Brief history: Dhaka Water Supply and Sewerage Authority (DWASA) was
established for proving two major emergency services namely potable water supply
and hygienic and modern sewerage system for Dhaka, one of the rapidly expanding
city in November 1963. Under the ordinance XIX of 1963, DWASA started
functioning in Dhaka Municipality with only 8 Lac populations and now its
operational area includes both Dhaka city and Narayanganj Municipality with more
than 12.5 million people. In 1986, another important responsibility for drainage
system of Dhaka city has been shifted to DWASA. Based on the tremendous
geographical expansion and population growth over the last two decades, DWASA
has been reorganized by DWASA Act, 1996 and according to this act, presently it is
being run as a service oriented commercial organization.
(b) Responsibilities: The major responsibilities and functions of DWASA are:
 Construction, operation, improvement and maintenance of the necessary
infrastructures for collecting, treating, preserving and supplying potable
water to the public, industries and commercial concerns,

25
infrastructures for collecting, treating and disposing domestic sewerage and
industrial wastes.
infrastructures for drainage facilities of the City.
According to Citizen Charter of DWASA, it provides the water connections to the
slum communities through Community Based Organization (CBO) or through land
owners subject to reception of such applications from them.
(c) Service area: At present the service area of DWASA extends from Mirpur
and Uttara in the North and to Narayanganj in the South. For better operation,
maintenance and customer care, the total service area of DWASA has been divided
into 11 geographic zones, which includes 10 in Dhaka city and 1 in Narayanganj.
Figure 2.5 shows the thematic map by each service zones of Dhaka city.
Figure 2.5 DWASA service areas in DMPA
7
1
6
2
3
5
4 8
9
10

26
(d) Infrastructures and establishment: Table 2.7 shows the data of DWASA till
October 2009:
Table 2.7 Infrastructures and establishment of DWASA
Ser No Description Acct Unit Qty
1. Water Treatment Plant Numbers 4
2. Deep Tubewell Numbers 533
3. Water production capacity MLD 2,177.91
4. Actual Water production MLD 2,032.04
5. Water Line Kilometer 2533.73
6. Water Connections Numbers 2,77,590
7. Sewer Line (2008-09) Kilometer 882
8. Sewer Connections Numbers 61,349
9. Storm Water Drainage Line Kilometer 275
10. Box Culvert Kilometer 9
11. Open Canal Kilometer 65
12. Drainage System (upto July 2004 &
including box culvert and open canal)
Kilometer 303.08
Source: DWASA (2009)
2.8.3 Water Supply Situation
DWASA serves a total of 14.15 million people of Dhaka Metropolitan Area and
Narayangong. This service area is projected to increase to 17.2 million by year 2025
while another 4.4 million will be staying within Dhaka Metropolitan Area but in areas
presently not served by DWASA. A sizeable number of population (estimates vary
from 10 to 60%) living in the DWASA service area are living in slum
areas (ADB, 2008). To serve such a huge population of Dhaka city is now
becoming a challenge for DWASA. Table 2.8 shows that the DWASA is heavily
dependent on groundwater with more than 87% of total water production coming
from groundwater source.
Table 2.8: Source wise water production of DWASA in October 2009.
Source Production
Capacity
Actual Production Source-Wise %
of ProductionMLD % of Capacity
Ground Water 1,878.74 1,782.37 94.87% 87.71%
Surface Water 299.17 249.67 83.45% 12.29%
Total: 2,177.91 2,032.04 93.30% 100.00%
Source: DWASA (2009)

27
But ground water depletion rate is more than 3m/yr which is alarmingly high
(Al-Mamoon, 2006; Paul, 2009). As a result no further abstraction from upper
aquifer (100-200m) is viable. However, DWASA has already started to draw water
from deep aquifer (> 300m) (DWASA, 2010). On the other hand the water quality of
peripheral rivers and lakes of Dhaka city are polluted in the highest order. Figure 2.6
shows the prediction of population and water demand in Dhaka urban areas basing
on the present supply i.e. 1500 mld (Al-Mamoon, 2006).
Figure 2.6 Prediction of population and water demand in Dhaka city.
2.8.4 Water Quality Monitoring System
According to DWASA sources, the groundwater and surface water as extracted are
being monitored and tested regularly by its own Quality Control and Research
Division. Saha, (2001) noticed that groundwater supplied by the DWASA is within
the acceptable limit of WHO guidelines. It was also found during testing of water
from WASA groundwater pump points at number of locations in Dhaka city. DWASA
conducts number of tests on important parameters like pH, turbidity, alkalinity,
residual chlorine, faecal coliform etc. of water in the quality control and research
laboratory of the organization. In addition, groundwater samples from Deep
Tubewells (DTW) are also tested for arsenic every three months and river water
samples are tested for chromium and aluminum every six months (Azam, 2005).
Figure O.1 of Appendix O shows the distribution of DTWs and water bodies around
the selected areas of Dhaka city. According to DWASA, necessary mitigation
measures are adopted if there is any change in the quality of water.
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
2005 2010 2015 2020 2025
Year
MLD
0
5
10
15
20
25
Million
Water Demand (mld) Shortfall(mld) in comparison with present water supply Population (million)

28
2.9 Economic Valuation of Diseases
2.9.1 General
There is no denying that water pollution lead to serious negative impacts on health
and various economic goods and services. The physical evidence is convincing.
The valuation of these impacts, however, has frequently been ignored because it
was thought that either:
 It is too difficult to establish direct cause-effect relationships.
 Placing monetary values on those effects, either health or productivity was
not feasible.
Economic valuation of health impacts due to consumption of water of urban water
supply and associated sanitation, hygiene and climatic factors was one of the
objectives of this thesis. Here, field data were used to make the valuation using
standard methods and statistical tools. This valuation can be defined as an attempt
to quantify and express in monetary terms the full value of diseases as affected due
to consumption of water of urban water supply and associated poor sanitation and
hygiene practices.
2.9.2 Importance of Monetary Valuation
 To compare benefits and costs- as planning process is influenced by
economic analysis (CBA).
 To set priorities. If one can compute the expected benefits of different
actions, and then one compares this to the costs of each action, this information
is a critical aid to setting priorities for action. The benefit of an analysis and the
use of quantitative (and, in some cases, qualitative) results is that it helps
societies to make more rational decisions on allocating scarce financial
resources.
 Economic valuation helps to bring the environment into decision-making
process.

29
2.9.3 The Major Economic Impacts of Pollution
There are four most important major economic impacts; these are:
 Health impacts are the most important and the ones that receive the most
attention. Also, it is often easier to estimate economic costs of health outcomes;
this information is useful in getting the attention of decision makers.
 Productivity impacts are often also very important and can be estimated
fairly easily. If individuals or firms need to install special equipment or take
special measures to protect themselves from pollution, these are measurable
economic costs. If polluted water reduces the productivity of natural systems
(crop or fishery production, for example), these are additional productivity costs.
Also, in some situations, pollution (especially air pollution) may be so critical
that industries are closed or transportation is restricted. Both of these steps
impose important economic and social costs on society.
 Ecosystem impacts may also occur when such things as underground
aquifers are contaminated, or vegetative areas die due to pollution. Ecosystem
impacts are harder to measure and value and the true impact may not be felt for
many years. Often they are included in a qualitative manner.
 Aesthetic impacts.
2.9.4 Techniques to Place Monetary Values on Environmental Impacts
(a) Market based methods:
 Production function approach
 Cost of illness approach
 Cost-based approaches
(b) Cost of illness approach:
 Costs of air/water pollution estimated by looking at costs of human health
impact. Dose-response function identifies relationship between level of pollutant
and degree of health effect (water quality and diarrhoea). Here value health
effect based on cost of illness, including:

30
 Direct cost of diseases:
 Home treatment cost: These are for extra fooding and/or nursing
costs.
 Transportation cost: For availing doctor/clinic/hospital support or/and
purchasing medicine at a long distance etc.
 Doctor‟s fee: Single doctor visit charge.
 Medical expenses: These are expended after visiting doctors for
purchasing medicines.
 Indirect cost of Diseases
 Parent‟s work lost (when both/either of them were patient)
 Parent‟s work lost due to child disease.
 Parent‟s leisure lost due to child disease.
 Applicability: Value health costs of water and air pollution.
 Limitations:
 Dose-response functions not available locally.
 Does not measure WTP to avoid illness.
2.10 Prevalence Rate (PR)
2.10.1 Importance
Prevalence Rate (PR) is a kind of tool to identify the severity of any particular issue.
In this study, PR of waterborne diseases of the selected areas of Dhaka city has
been used in order to identify the state of vulnerability of the surveyed population.
The greatest waterborne risk to health in most cases is the transmission of faecal
pathogens, due to inadequate sanitation, hygiene and protection of water sources.
Hence population density, state of water sources including its availability, sanitation
system and hygiene practices are the major concerned. Where the population
density is high and sanitation is inadequate, unprotected water sources in and
around the temporary settlement are highly likely to become contaminated. If there
is a significant prevalence of disease cases and carriers in a population of people

31
with low immunity due to malnutrition or the burden of other diseases, then the risk
of an outbreak of waterborne disease is increased. That is why the higher PR value
signifies the higher vulnerability of population to the waterborne diseases.
2.10.2 Formula Used in PR
In this study Equation 2.2, 2.3, 2.4 and 2.5 were used to identify the PR of different
diseases out of 1000 people.
 PR Based on Individual Group (PRIG):
(2.2)
 PR Based on Group Total (PRGT):
(2.3)
 PR of Particular Group Based on Total Population (PRTP):
(2.4)
 PR of Total Population (PR):
(2.5)
2.11 Statistical Analysis Tools
During analysis following statistical tools have been used to obtain objectives of this
study:
2.11.1 Arithmetic Mean: If there are n numbers of items x1, x2, x3 . . . . xn then the
average value x is given in the Equation 2.6.
n
xxxx
x n

....321
(2.6)
PR=
Total Number of Incidences×1000
Total Population Surveyed
PRIG=
Total Number of Incidences Based on Individual Group×1000
Total Surveyed Population of That Individual Group
PRTP=
Total Population Surveyed
PRGT=
Surveyed Group Total Population

32
2.11.2 Grade Point Average (GPA): If there are n numbers of items x1, x2, x3 . . . xn
and having y1, y2, y3 . . . . yn grade points respectively; then the GPA is given in the
Equation 2.7.




 n
i
i
n
i
ii
y
yx
GPA
1
1
2.11.3 Standard Deviation: The standard deviation is a measure of how widely
values are dispersed from the average value (the mean). The formula used for
unbiased method can be shown in the Equation 2.8.
)1(
)( 2




n
xx
Where x is the sample means of n number of x data.
2.11.4 Correlation Coefficient (Cr): The correlation coefficient to determine the
relationship between two properties. The formula can be shown in the Equation 2.9.





22
),(
)()(
))((
yyxx
yyxx
Cr yx
Where x and y are the sample means of two data sets.
(2.7)
(2.8)
(2.9)

33
CHAPTER 3
METHODOLOGIES
3.1 Introduction
The objective of this research is to study the health impacts of urban water supply
on the vulnerable communities of selected areas of Dhaka city. Here the data of
twenty one administrative thanas of Dhaka city has been considered and from there
only the four most affected thanas have been selected for this study. To attain the
main objective, effort has been made to carry out qualitative assessment of urban
water supply system, sanitation and hygiene practices of different vulnerable
communities of the most affected areas of Dhaka city. Moreover the impacts of
those factors have been quantified in terms of number of incidences and assess the
economic losses incurred. Since climatic factors play a vital role in case of per
capita consumption of water and other microbiological organisms‟ growth, hence an
effort has also been made to identify the correlation between selected climatic
factors and the worst waterborne disease‟s incidence of the same selected areas of
Dhaka city. These all are used to develop overall grading chart showing prevailing
waterborne diseases‟ profiles and costs of diseases with respect to selected areas,
communities and urban water supply options. These results have also been shown
as thematic maps of Dhaka city using Geographical Information System (GIS)
software.
3.2 Methodologies
Since the causes of waterborne diseases are not limited to urban water supply
system/options alone only, rather cover wide spectrum like food, sanitation,
personal hygiene, climate and other behavioral factors too. Hence, for this thesis
work, health impacts of vulnerable people due to water provided by DWASA and
associated sanitation, hygiene and climatic factors have been considered. The
methodologies for this study have been shown in the Figure: 3.1.
(a) Initially existing secondary data related with waterborne diseases of all the
administrative areas of Dhaka city as preserved and maintained by authenticated
sources has been collected in order to identify the health state of Dhaka dwellers as
per as waterborne diseases are concerned and rank them basing on the severity.

34
(b) Since above data would represent only the number of patients reporting
and/or hospitalized without any reference to baseline data. Hence population of
respective areas of Dhaka city for the year of 2010 has been incorporated to
generalize the data as such. Here population data of 2001 has been used as base
data in order to find out the population for the year of 2010 basing on growth rate of
State of Dhaka city as
per waterborne diseases
Collection of waterborne diseases
related data from Secondary Sources
Identification of the most
affected areas
Selection of locations
and time for the top 4
most affected areas
Vulnerable
Population
Climatic Data
from BMD
Urban water supply
Sanitation
Practices
Hygiene practices
Correlation of
Climatic factors-
Waterborne diseases
Health impacts in
terms of number of
patients of different
waterborne diseases
Costs of main
waterborne
diseases
GIS Representation
of relevant data in
thematic maps
Figure: 3.1 Methodology diagram
Prevalence Rate
of Non-reporting
Incidences

35
6% as stated by DCC (2009). Due to time and resource constrains only the top 4
most affected administrative areas has been selected.
(c) “Slum-map” developed by CUS (Figure 3.2) has been studied in order to
locate the vulnerable people residing at various places of those selected areas of
Dhaka city as per the considerations described in Section 2.2.2 and to identify urban
water supply options as explained in Section 2.5.2. For sampling of population,
“Convenience Sampling Method” was carried out in order to materialize time, money
and other resources related constrains. Again to select better time frame for primary
data collection, the records of waterborne diseases‟ incidences of those selected
areas of Dhaka city have been studied and hence a general monthly trend has been
developed.
(d) To identify the impacts, the primary data has been composed of all the
relevant questionnaires, sanitary inspection (SI) and water samples collection.
Based on all these data results are shown with respect to sample areas, community
types and urban water supply options and draw overall conditions as a result of a
particular issue and associated health impacts and costs of diseases thereof.
Additionally data on climatic factors have been collected from BMD to formulate
correlation among them. Here the climatic factors selected for this thesis work are
monthly rainfall, humidity and temperature (maximum, minimum and average) for
Dhaka station only. Monthly trends of those meteorological factors and diarrhoeal
incidents have been superimposed and statistical tools have been used to find out
the correlation.
(e) Finally recommendations are made for monitoring, improving water quality,
sanitation and hygiene practices and enforcement programs. Additionally number of
thematic maps has been generated using GIS software like ArcGIS (ArcCatalog and
ArcMap) to show the result on Dhaka city perspective so as to help the decision
maker in identifying areas of improvement.
3.3 Design Procedure
In this study health impacts resulting from urban water supply was assessed for
slum and low-income communities of selected areas of Dhaka city by collecting
relevant information from field. This section provides chronological description of the

36
Figure 3.2 Slums of Dhaka metropolitan area (CUS, 2005)
Mirpur
Uttara
Gulshan
Tejgaon
Mohammadpur
Hazaribagh
Kamrangirchar
Rampura
Banani
Badda
Khilkhet
Shyampur

37
methodologies used in this study. To assess the health impacts and costs valuation
of the diseases, necessary methods/statistical analysis tools have been used.
3.3.1 Selection of Vulnerable Communities
It is one of the most important issues on which the whole study has been based on.
The selection of vulnerable communities started with the evaluation of secondary
information as attained from ICDDR,B and DSH and personal contact with experts
and scientists in this regard. Both the institution referred that most of the time it was
the low-income and slum people who visited them frequently round the year. Hence
in this study, these two communities have been referred as vulnerable communities
and their considerations have been given in the Section 2.2.2.
3.3.2 Vulnerability Score
In order to find the state of vulnerability of the given community, the percentage of
exposure for a particular disease with respect to some predefined factors/sub-
factors have been considered. In this study a total 10 points have been assigned for
each factors/sub-factors for their vulnerability. Each increment of 10% in exposure
accounts for 1 point increment in vulnerability score and intermediate values are
calculated proportionately as such. The Table 3.1 shows such vulnerability score
and state of the vulnerability. As it can be seen in the table that vulnerability of the
community increases with the increase of percentage of exposure. However most of
the case 0% exposure means “No data” was found at the time of survey.
Table 3.1 Vulnerability score and state of vulnerability.
Serial Exposure to Particular Disease
(%)
Vulnerability
Score
State of
Vulnerability
1. 10 1
Low
2. 20 2
3. 30 3
Medium4. 40 4
5. 50 5
6. 60 6
High
7. 70 7
8. 80 8
Very High9. 90 9
10. 100 10

38
Again, the basic data of Table 3.2 has been used in order to grade the community,
selected areas and urban water supply options and to represent state of the
selected areas in the thematic maps as per color code.
Table 3.2: Basic data for grading and representation.
Vulnerability
Score Range
Grade Point Grade
Representation
Color Code Use
≥ 8 to 10 4 Very high In thematic map
≥ 6 to <8 3 High
≥ 3 to <6 2 Medium
≥ 0 to <3 1 Low
3.3.3 Identification of Urban Water Supply Options
The method of selection of water points was primarily based on reconnaissance
survey conducted in Gulshan and Mirpur areas. There were private owned water
points and WASA pump house from where people need to pay for the services.
Urban water supply pattern as identified in slum areas were discussed in Section
2.5.2. The water supply options found in the study areas are given in the Table 3.3.
Table 3.3: The water supply options found in the study areas.
Serial Description of Options Community Using Options
1. Piped water supply with reservoir Low-income
2. Piped water supply without reservoir Low-income/slum
3. Hand pump connected to supply line Low-income/slum
3.3.4 Field Survey
(a) Questionnaires: During questionnaires survey, effort was made to
collect all the relevant information leading to the attainment of the thesis objectives.
A detailed Questionnaire Survey Form (QSF) was made right after the
reconnaissance survey and appended as Appendix A. The form contained as much
as 28 questions of different types in order to acquire following general information
regarding:
 Community type i.e. slum or low-income groups.
 Economic conditions.
 Sanitation and hygiene practices.
 Accessibility to urban water supply and their patterns.
 Occurrences of various waterborne diseases etc. during last one year.

39
 Costs they were to bear as a result of waterborne diseases.
Here each question acted as qualitative aspect of either urban water supply or
sanitation or even hygiene related matter of the vulnerable people and quantitative
aspect i.e. health impacts of the same in terms of number of incidences/occurrences
of waterborne diseases those had taken place last one year. The QSF was also
used for the assessment of prevalence rate of mostly affected waterborne diseases
among the communities for which they were to pay the most. During the survey, the
QSF revealed three such most affected waterborne diseases on which the total
calculation of the thesis has been based on; these are:
 Diarrhoea
 Typhoid.
 Eye Infections
Here overlap of water consumption was not considered in this study because people
especially workers or laborers drink water from their service places, restaurants and
from many other locations which might be hygienically more vulnerable than their
households. It will be very complicated if all the sources of water consumption
patterns have to be considered. Since one of the objectives was to calculate
valuation of diseases, hence the focus was on the diseases for which target groups
were to spend some money during the time of sufferings.
Qualitative Assessment Basing on QSF: Here all the data were put into the
database and the questions or the attributes those were assumed to be directly
involved in the contribution of waterborne diseases‟ incidences were filtered and
results were obtained as such. Here is the list of questions used for data filter
operation:
 What is the source of your water?
 What is the distance of water point from your house?
 How much time do you take to collect water from the source?
 How much water do you receive every day?
 What is the general condition of supplied water?
 Do you boil your drinking water?
 How much time you boil your drinking water?
 Where do you store your drinking water?
 Do you use lid to cover your container?

40
 What type of Sanitation System you use?
 What do you use to wash your hands after defecation?
These results were collected either in terms of HH or number of respondents and
displayed against:
 Selected areas.
 Community types
 Urban Water Supply Options
 Overall Conditions
Quantitative Assessment Basing on QSF: At this stage factors of qualitative
assessment were used for identification of health impacts in terms of quantitative
assessment. Since water quality and source water condition have direct effect on
health, hence, the lab-test result on microbiological quality (faecal coliform) of water
and SI risk grading have been incorporated as additional attribute columns. Hence
quantitative assessment was made with respect to twelve factors. These are:
 The source of water.
 Urban water supply options.
 Distance from HH to water source.
 Time to fetch water from water source.
 Demand of water being met.
 Boiling practices prevailing in the community
 Duration of time spent to boil drinking water.
 Storage of drinking water.
 Sanitary system in use.
 Hand wash practices after defecation as personal hygiene.
 Water quality in terms of microbiological result.
 SI Risk Grading
Here for the calculation of health impacts, the number of incidences and total
number of members affected by respective waterborne diseases against each
above factors were found out. Actual numbers of HH members exposed to the
particular disease were used for calculation during data filtering process. However,
where there were no incidences, no exposures were assumed and percentages
were shown as zero. Again where there were only few persons and all were affected

41
by same disease, then percentage shown as 100%. This assumption will naturally
yield high percentage of incidence rate against exposure which is rare in the reality
due to background level of immunity as explained in the Section 2.3.3. The process
of data filtration shown in the following steps:
 Step-1: To find out the number of HH members exposed to diarrhoea,
typhoid and eye infections for the slum of Gulshan area. Here criteria used for
filter operations are:
o Thana: Gulshan
o Community type: Slum.
o Diseases: Diarrhoea, typhoid, eye infections (each considered
separately)
The results have been shown in terms of health matrix in the Table 3.4 through
Table 3.8.
Table 3.4: Data filtering process: Step-1
Thana
Community
type
No. of
Family
Members
per HH
TOTAL
Affected
by
Diarrhoea
TOTAL
Affected by
Typhoid
TOTAL
Affected by
Eye
Infections
Gulshan Slum. 6 6 6
Gulshan Slum. 3 3
Gulshan Slum. 3 1 3
Gulshan Slum. 6 6
Gulshan Slum. 4 1
Gulshan Slum. 9 1 2
Gulshan Slum. 6 6 6
Gulshan Slum. 2 2
Gulshan Slum. 4 4 4
Gulshan Slum. 3 3 3
Gulshan Slum. 5 4 1 5
Total: 28 3 36
% of incidence against Surveyed
Population (rounded to next
higher number)
55 6 71
One can see that the same family members might not be affected by more than one
disease at the same time and 51 members should be used for reference data in
order to find percentage of incidences. So to find out the correct percentage of

42
affected people against actual exposed HH family members, this matrix needs to be
corrected as such.
 Step-2: To find out the actual number of HH members exposed to diarrhoea,
typhoid and eye infections respectively. Here, all the non-blanks data have been
queried by eliminating the blank data for specific disease. Hence three different
tables have been generated each depicting the actual scenario of single disease.
o For Diarrhoea:
Table 3.5: Data filtering process for diarrhoea: Step-2a
Thana
Community
type
No. of
Family
Members
per HH
TOTAL
Affected by
Diarrhoea
TOTALAffected
byTyphoid
TOTALAffected
byEyeinfections
Gulshan Slum. 6 6 6
Gulshan Slum. 3 1 3
Gulshan Slum. 4 1
Gulshan Slum. 9 1 2
Gulshan Slum. 6 6 6
Gulshan Slum. 2 2
Gulshan Slum. 4 4 4
Gulshan Slum. 3 3 3
Total: 28 3 27
So it shows that out of 9 HHs of 42 family members only 28 persons were affected
by diarrhoea.
o For Typhoid:
Table 3.6: Data filtering process for typhoid: Step-2b
Thana
Community
type
No. of
Family
Members
per HH
TOTALAffected
byDiarrhoea
TOTAL
Affected by
Typhoid
TOTALAffected
byEye
infections
Gulshan Slum. 9 1 2
Total: 5 3 5

040404124P-Main Thesis Paper

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