Table of Contents
List of illustrations xiii
Preface xv
Acknowledgements xvi
1 Introduction 1
The importance of water 1
Water in the developing world 3
A definition of small water supplies 3
The hydrological cycle 4
Geology 6
2 Small water supplies 12
Springs 16
Wells 21
Boreholes 26
Surface water 29
Rainwater collection 32
Desalination 33
Fog collection 33
Other associated components 34
3 Physical properties of water 42
Tastes and odours 42
Conductivity 43
Hardness and softness 44
Hydrogen ion or pH 47
Turbidity 50
Insufficiency 52
4 Risk assessment 53
Rainfall and weather 60
Sampling programmes 62
Sanitary surveys and risk assessment 73
5 Water and health 77
Microbiological considerations 81
Indicator organisms 88
Outbreaks of disease associated with small water supplies 94
6 Waterborne diseases 99
7 Viral diseases 101
Enteroviral diseases 101
Viral gastroenteritis 102
Viral hepatitis 104
8 Disease-causing bacteria 107
Campylobacter 107
Cholera 111
Escherichia coli 115
Salmonella typhi 120
Shigella 122
Yersinia 124
Other bacteria of potential concern 125
9 Environmental or adventitious bacteria 129
Aeromonas 129
Burkholderia 130
Plesiomonas 130
Pseudomonas 131
10 Protozoa 132
Amoebic dysentery 132
Cryptosporidium 134
Cyclospora 141
Giardia 142
Naegleria 145
11 Helminth infestation 146
Dracunculiasis 146
12 Water-related diseases 148
Dengue fever 149
Lymphatic filariasis 150
Malaria 150
Yellow fever 152
13 Water-contact diseases and cyanobacteria 153
Schistosomiasis 153
Cyanobacteria 154
14 Chemical contamination 161
15 Inorganic contaminants 163
Aluminium 163
Arsenic 167
Asbestos 170
Copper 171
Iron 173
Lead 174
Manganese 177
Nitrates 179
Minor inorganic contaminants 185
16 Organic contaminants 191
Disinfection by-products and trihalomethanes 191
Organic solvents 195
Pesticides 198
Polynuclear or polycyclic aromatic hydrocarbons 204
Minor organic contaminants 205
17 Radioactive contamination 210
Radon 211
Uranium 216
18 Treatment options 217
Disinfection 220
Contaminant removal 227
Other treatment systems 235
19 Action to improve supplies 244
Advice 247
Boil water advisory notices 251
Formal statutory action 253
Directive on the Quality of Water Intended for Human Consumption 253
UK Drinking-water legislation 256
Other legislation for securing improvement 272
20 UK governmental control 276
21 USA 278
The direct influence of surface water 279
Borehole protection 280
Education and advice 284
Indian land 286
Problems 286
References 290
Index 309
