Water Supply for Rural Areas and Small Communities
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WORLD HEALTH ORGANIZATION MONOGRAPH SERIES No. 42 I WATER SUPPLY FOR RURAL AREAS AND SMALL COMMUNITIES WATER SUI 'PLY FOR RURAL AR EAS AND SMALL COMMT JNITIES tIf1 EDMUNDG. WAGE 111 Chief Engineer and Associate Chief 4 f Field Party, Division of Health and Sani ztion, Institute of Inter-American / fairs, Rio de Janeiro, Brazil Sanitary Engineer, Division of Environmental Sar tation, World Health Organization, Genevh Switzerland WORLD HEALTH ORGA 'IZATION PALAIS DES NATIONS GENEVA Authors alone are responsible for views expressed in the Monograph Series of the World Health Organization. The mention of specific companies or of certain manufacturers' products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature which are not mentioned. Proprietary names are distinguished by initial capital letters. PRINTED IN SWITZERLAND CONTENTS I I I Page I I. Introduction. ............-\ ~ ........ 9 Chapter 1. Basic considerations. ....( ........ 13 I Chapter 2. Planning. .................. 26 Chapter 3. Ground water .......1 ........ 57 ................. Chapter 4. Pumps - I 121 Chapter 5. Surface water .......i ........ 161 Chapter 6. Treatment under rural conditions ....... 171 Chapter 7. Distribution and use ....\ ........ 194 Chapter 8. Importance of management . I, ........ 227 Chapter 9. Personnel and training .......... 232 Chapter 10. Administration and finance ......... 236 Chapter 11. Operation and maintenance . 1 ........ 243 I Chapter 12. Long-term planning ............ 248 WATER SUPPLY FOR RURAL AREAS ANNEXES Page Annex 1. List of reviewers .................... Annex 2. Conversion factors .................... Annex 3. Flow measurements .................... Annex 4 . Collection of water samples ................ Annex 5 . Construction of hand-dug wells ............ Annex 6. Typical specifications for a hand pump ........... Annex 7. Construction of small dams .............. I Annex 8. Financial statements for small water-works ......... Annex 9. Some practical hints on the operation and maintenance of small water-supply systems in rural areas ................ Select bibliography ....................... 331 Index .................... : .......... 335 FIGURES Page The five principal causes of death in certain countkies of the Americas. 1952 14 Simple water-prospecting equipment .................37-38 A portable water-laboratory field kit ................. 52 Geological formations ........................ 58 Occurrence and distribut~onof sub-surface water ............ 59 Comparison of free and confined ground-water ............ 60 Shallow well in free-water zone .................... 61 Well tapping confined water ..................... 62 Types of bailers and buckets used for removal of material from holes ... 65 Hydraulic methods of exploration .................. 66 Drilling and boring methods of exploration .... ........ 69 Section of well shaft : first lift ................... 73 Dug well with protective casing and platform ............. 77 Dug well lined with concrete or clay tile ................ 78 Reconstructed dug well with buried slab ............... 79 Dug well : casing descending with excavation ............. 80 Amazon well ............................ 81 Amazon well : grate beams ................... 82 Large well with horizontal perforated pipes ............. 84 Driven well with drop pipe and cylinder and protective platform ..... 85 Typical well points ......................... 86 Well-point system ........................ 87 Tube-well boring by water-jet system ................. 91 Jetting a large-diameter casing (I) ................... 94 Jetting a large-diameter casing (11) ................. 95 Typical boring tools ........ .............. 98 Properly protected spring (I) ....... .......... 113 ....... ........... 125 WATER SUPPLY FOR RURAL AREAS Page A sanitary rope-and-bucket well (11) ................. 133 Continous-belt bucket pump ..................... 134 Multicellular band pump ...................... 134 Centrifugal pumps : turbine-type (I) and volute-type (11) ......... 135 Centrifugal pumps : directly connected to power unit (I) and with belt-drive (11) 136 Jetpump ............................. 137 Typical installation of jet pump ................... 137 Section of typical deep-well turbine pump ............... 138 Typical characteristics of deep-well turbine pumps .......... 142-143 Effects of vanes and size of intakes on performance curve and capacity of centrifugal pumps ........................ Two pumping situations. showing centrifugal pump capacity curves .... Deep-well turbine pump : electric motor (I) and direct drive and angle-gear head (11) ........................... Deep-well turbine pump : direct belt drive (1) and belt drive and angle-gear head (TI) ............................ Main parts of air-lift pump ..................... Hydraulic ram ........................... Windmill ........................... Properly designed hand or windmill pump with cylinder above ground ... Typical arrangement of windmill tower. pump. and well ......... 157 Typical pump installation using standard tee and underground arrangement to discharge water below frost line .................. 159 Cistern with sand filter (pump installation optional) ........... 164 Small intake structure ........................ 167 Profile of pipeline from source to distribution system .......... 169 Filtered water outlet ........................ 177 Equipment for feeding hypochlorite solution .............. 182 Apparatus for hypochlorination ................... 183 Berkefeld filter ........................... 191 Typical zeolite water.softener. manually operated ............ 193 Distribution reservoirs : theoretical reservoir capacity required ...... 197 Ground-level reservoirs ....................... 200 Elevated storage tanks ....................... 203 Water-level indicator for elevated storage tanks ............. 204 Systems of distribution ........................ 208 Topographical plan of village and surrounding area ........... General plan of distribution system .................. Possible arrangement of public fountain ................ Pressure tank system ........................ Plumbing rods ........................... Locally made equipment ....................... Caissons and lining shutters ..................... Sinking headframe (type " G "). North Region. Nigeria : general arrangement Small earth dam .......................... Introduction It is difficult to establish the exact degree of the importance of water to man in his arduous climb up the ladder of civilization. It is certain, however, that without water there would be no life of any kind on the earth and that, without water readily available in adequate quantity and free oj pathogenic organisms, man's progress is tremendously hindered. Although no actual count is possible, billions of man-days of labour are undoubtedly lost annually because of illness and death from water-borne diseases. Un- fortunately, the areas which can least afford this economic loss are the places where such sickness and death are most rampant. The responsibility for reducing this tremendous waste falls on governments and, specijically, on health administrations. It is the aim of this monograph to assist the government officials who must meet this challenge. Among those most directly concerned are public health administrators, medical oj3cers of health, civil or sanitarj~engineers engaged in public health, and sanitarians. In an article discussing long-range planning for water service in the USA, Dr Abel Wolman of the Johns Hopkins University, Baltimore, has said: " Adequate water service, at a reasonable price, is an attainable objective. If it has not yet been attained, it is only because the skilled workers in this jield have not seenjit to dejne the objective, to delineate the principles which should control its implementation, to devise the structure for administration and management, and to establish the fiscal principles which might safely and wisely provide the sinews for the project."46 It has been the aim of'the authors of the present monograph to cohsider these elements in particular relation to the establishment of services for rural areas and small communities. An effort has been made to discuss the problems of rural water-supply in a clear and realistic manner and to avoid nebulous concepts which cannot possibly apply to most of the rural underdeveloped areas of the world at the present time. On the other hand, the authors have tried to show the minimum facilities that are necessary in small communities and individual households in order to satisfy the basic personal andpublic health objectives of water-supply schemes. Perhaps the most important single step in a water-supply programme is to get it started: in countries where it has been possible to get a programme under way it has invariably prospered and expanded, and the result has usually been the establishment of formal government agencies to handle 10 WATER SUPPLY FOR RURAL AREAS the work. It is of the utmost importance, therefore, that the best possible start be made. The authors have tried to examine criti>ally many of the administrative as well as technical factors which contribute to successful programmes. However, it has not been possible to include in a monograph of this size all the specsc information available on the various aspects of the subject. Extensive detail on many subjects has had to be omitted; but sufjicient reference