CONTENTS Preface ix Acknowledgements xiii Part I Health and Pollution 1 Engineering and infectious disease 3 1.1 Introduction 3 1.2 Water-related infections 4 1.3 Excreta-related infections 11 1.4 Refuse-related infections 16 1.5 Housing-related infections 17 1.6 Summary 20 1.7 References and further reading 20 2 Health and water chemistry 21 2.1 Introduction 21 2.2 The absence of necessary chemicals 22 2.3 Harmful organics 23 2.4 Harmful inorganics 24 2.5 References and further reading 27 3 Water quality and standards 29 3.1 Drinking water quality 29 3.2 Waste water quality 35 3.3 Industrial wastes 39 3.4 Bathing water quality 41 3.5 Irrigation water quality 41 3.6 Water quality and fish 42 3.7 References and further reading 43 Part II Water Supply 4 Water supplies in developing countries 47 4.1 The haves and the have nots 47 4.2 Operation and maintenance 49 4.3 Appropriate technology 50 4.4 Benefits 51 4.5 Cost recovery and the private sector 55 4.6 Rural supplies and self-help 56 4.7 Evaluation 58 4.8 Hygiene education 59 4.9 References and further reading 60 Rural water supply 63 5.1 Breakdowns and technology 63 5.2 Sources of water 64 5.3 Raising water 4. 74 5.4 Storage79 5.5 Tfeatment 81 5.6 Water distribution 86 5.7 References and further reading 87 Urban water supply and water treatment 89 6.1 Introduction 89 6.2 Coagulation and sedimentation 90 6.3 Filtration 91 6.4 Disinfection 94 6.5 Distribution 100 6.6 Water demand management 106 6.7 References and further reading 108 Part III Excreta and Refuse: Treatment, Disposal and Re-use 7Excreta disposal in developing countries 113 7.1 The haves and the have nots 113 7.2 Marketing of low-cost sanitation 113 7.3 Urban sanitation 116 7.4 References and further reading 118 8 Types of excreta disposal system 119 8.1 Introduction 119 8.2 Pit latrines . 119 8.3 VIP latrines 122 8.4 Difficulties with pit latrines 124 8.5 Pour-flush toilets 129 8.6 Vault toilets and cartage 131 8.7 Septic tanks 132 8.8 Small-bore sewers 134 8.9 Other systems 135 8.10 Communal latrines 137 8.11 Soil conditions 138 8.12 Soakaway design 140 8.13 Personal hygiene 143 8.14 Sullage disposal 143 8.15 Nightsoil and sludge re-use and disposal 143 8.16 Water availability 146 8.17 References and further reading 147 9 Planning a sanitation programme 149 9.1 Programme context and content 149 9.2 Choice of system 151 9.3 Social factors 153 9.4 Costs 157 9.5 Operation and maintenance 161 9.6 Incremental sanitation 161 9.7 References and further reading 163 10Waste water treatment 165 10.1 Introduction 165 10.2 Waste characteristics 165 10.3 Waste stabilization ponds 166 10.4 Aerated lagoons 173 10.5 Oxidation ditches 175 10.6 Pathogen removal 176 10.7 Sewage workers' health 177 10.8 References and further reading 177 11 Surface water drainage 179 11.1 Introduction 179 11.2 Town planning implications 181 11.3 Technical aspects 183 11.4 Institutional aspects 185 11.5 References and further reading 188 12 Refuse collection and disposal 189 12.1 Introduction 189 12.2 Waste characteristics 189 12.3 Hazards of refuse mismanagement 190 12.4 Storage and collection 191 12.5 Treatment and disposal 194 12.6 References and further reading 196 13 Composting 197 13.1 Aerobic and anaerobic composting 197 . 13.2 Techniques 199 13.3 Carbon/nitrogen ratio 201 13.4 Problems of composting 202 13.5 Individual composting toilets 203 13.6 References and further reading 203 14 Health aspects of waste re-use 205 14.1 Introduction 205 14.2 Health and agricultural re-use 205 14.3 Health and fish farming 211 14.4 References and further reading 213 Part IV Environmental Modifications and Vector-borne Diseases 15 Engineering control of arthropod vectors 217 15.1 Introduction 217 15.2 Mosquito-borne diseases 217 15.3 Fly-borne diseases 230 15.4 Chagas' disease and bugs 236 15.5 Lice, fleas, ticks, and mites 236 15.6 Conclusions 239 15.7 References and further reading 239 16 Dams, irrigation and health 241 16.1 General considerations 241 16.2 Onchocerciasis 244 16.3 Malaria 246 16.4 Arboviral infections 247 16.5 Bancroftian and malayan filariasis 247 16.6 Spillways and reservoir release policies 248 16.7 References and further reading 251 17 Schistosomiasis 253 17.1 Introduction 253 17.2 Engineering methods in Schistosomiasis control 258 17.3 Schistosome removal from water and wastes 269 17.4 References and further reading 272 Appendix A: Biological classification conventions 275 Appendix B: Glossary 277 Appendix C: Checklist of water-related and excreta-related diseases 285 Appendix D: The life cycles of certain helminths infecting man 291 Appendix E: Units 297 Index 299