WATERSUPPLY

FORRURAL AREAS AND SMALL COMMUNITIES

2

CONTENTS

PageIntroduction . . . . . . . . . . . . . . . . . . . . .3 DEVELOPMENT OF A WAfER-SU.I.'PLY PROGRAMME

1. Basic considerations . 2. Planning. . . . . .INSTALLATIG:-. OF VARIOUS TYPES OF WATER-SUPPLY SYSTEMS

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3. Ground water15 4. Pumps.22 5. Surface water32 6. Treatment under rural conditions .34 7. Distribution and use. ...36 MANAGEMENT OF WATER-SUPPLY SYSTEMS8. Importance of management50 9. Personnel and training53 10. Administration and finance55 11. Operation and maintenance58 12. Long-term planning62 References63

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 tllld that, without water readily available in adequate quantity and free of pathogenic organisms, man's progress is tremendously hindered. Although no actual count is possible, billions of man-days of labour are undoubtedly lost a11nually 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 JOT reducing this tremendous waste falls on governmentsand, specifically, 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 officers of health, civil or sanitary engineers engaged in public health, andsanitarians.In an article discussing long-range planning for water service in Ihe USA,D1 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 field have not seen fit to define the objective, to delineate the principles which should control its implementation, to devise the structure for administration and management, and to establish thefiscal principles which might safely andwi ely provide the sinews for the project. "46 It has been the aim of the authors of the present monograph to consider these elements in particular relation to theestablishment 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 persmzal and public health objectives of water-supply schemes.

The concepts presented in this monograph have evolved as a result of I!Xpe ic:::::: cullecced from many parts of the world. They are based on the firm conviction of the authors that :(1) in most small towns and villages in rural areas, more health benefits can be gained from money spent on a water-supply programme than in any other way;(2) there will be little public health benefit from a water supply which does not provide water in adequate quantity and quality a11d in a way con venient to the population ;(3) the sanitary (or public health) engineer is the key element in the water programme;(4) health administrations should take an active interest and play an important role in the promotion, execution, and management of rural water supply systems.

DEVELOPMENT OF A WATER-SUPPLY PROGRAMME

BASIC CONSIDERATIONS

Public Health Importance

It is difficult to imagine any clean and sanitary environment without water. Invariably, the progress of sanitation tf1roughout the world has been closely associated with the availability of water; and, the larger the quantity anJ the better the quality of the water, the more rapid and exten sive has been the advance of public health. The history of public health is filled with both tragic and glorious milestones in which water was the important factor.Since all biological life is dependent on water, i must be obtained atintervals by all plants and animals, so that life develops around this need. Men built most of their early communities near the watercourses which served their economic, social, and physiological requirements. As technology developed, it became possible to transport water for physiological needs and to exploit more profitably other resources and features, such as topo graphy, for improved community locati()n.Men have used water since the dawn of history; but the realization of its importance and, in some instances, of its danger, to health is a relatively recent development. Even today this knowledge is not complete, parti cularly with regard to the relationship which apparently exists between the quantity of water available per person and the incidence of certain communicable diseases. During the last century, water-borne epidemics and subsequent epidemiological studies focused attention on water quality and on the role of the precious liquid as an agent for the transmission of disease. Early investigt'.tions were principally concerned with cholera and typhoid fevers and, later, with all diarrhoeal diseases. More recently, increasing attention has been given to the rule of water in the transmission of certain virus diseases.Water-treatment practices for the control of bacteriological quality,begun in the late 1800's and the early part of the present century, dramatically demonstrated the need for and value of these measures. Since then, cholera has been eliminated from most countries, and typhoid is rapidly fo'.Jowing.

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In many areas of the world the control of diarrheeal diseases continues to be a major public-health problem. Among difficulties encountered, the lack of diagnostic facilities makes specific identification almost impos ible. Today, diarrhoeal diseases as a group are still the leading cause of death in many countries, as Table I and Fig. 1 reveal. Fig. 1 is based on probably the best statistical data available at present on the major causes of death in countries of which a great many can be considered to be rural in charac ter and economically underdevdoped. This figure is the result of a special survey made by the Pan American Sanitary Organization,26 and the data given were obtained from reports furnished by the official health agencies of the countries named. It will be noted that, in nine of the 18 countries reporting, the diarrhoeal diseases are the major cause of death, and that in three others they are the second cause. The coverage of the data is typical of that obtainable in tropical and sub-tropical underdeveloped countries, and is an indication of the best that should be expected from similar areas of the world where no comparable statistical data are actually available.The importance of the availability of water in the control of diarrhoea has been suggested by several investigators. 22 27 42 44 Watt et al. 44 indicate that, where the risk is high, as in areas with high death-rates from diarrhoeal disease, water availability can be the most important environ mental factor.

Role of the Central Government and Health Administration DEVELOPMENT OF A WATER-SUPPLY PROGRAMMEThe central health administration is the most logical agency to take the lead in promoting such programmes, for several reasons :1. There are few other investments of effort which will repay as muchin health benefits as rural water-supply programmes, since an adequate and safe water-supply is a basic requirement of a healthy environment. 45 49 a, b2. The provision of safe water is one of the principal environmentalcontrol measures against the transmission of most diarrhoeal diseases. which often constitute the major public-health problem in rural areas.3. The promotion of rural water-supplies depends to a large extent on con.munity action. Health agencies are usually experienced and equippedto foster such action and participation by the people.4. The public works administration which normally carries out public service projects such as water supply is usually too occupied with large works to give proper attention to small, rural water-supplies. This is probably one of the chief reasons why so little has been done in this field in many countries.5. Health aspects are often poorly understood and sometimes com pletely disregarded when the health administration is not intimately involved in the planning and execution of the water programme.

Chapter 2PLANNING

Categories

Personnel Preparation and Training

The proper planning, implementation, and management of water supply systems depend principally on the availability of competent personnel. The leader in this work must be an engineer, preferably a sanitary engineer, who is trained for the technical tasks involved and is experienced in the field of public health planning and administration. To be most effective in a health administration, the engineer must be familiar with the broad principles and aspects of public health and the relation of engineering to them. His understanding must extend, furthermore, into the area of general economic and social developmenL of which public health and sanitation are a part. The third report of the WHO Expert Committee on Environ mental Sanitation 49 correctly points out that environmental sanitation programmes should be integrated with other community programmes and in phase with the general progress and needs.To assist the engineer in the implementation of a rural water-supply programme, competent sub-professional assistants are needed. These will include :(I) foremen of the labour crews which carry out innumerable tasks involved in investigations, construction, and operation of water supplies;(2) topographers to make the necessary land surveys upon which design and plans are based;(3) draftsmen and calculators to draw the plans and make the calcu lations, under engineering supervision;(4) waterworks operators to keep the systems running properly.

Training

Training for personnel concerned with rural water-supplies may be divided into: (a) professional academic training,(b) observation visits,(c) short special courses (usually in-service type), and (d) supervised expe rience.

General

Financial Planning

Plans for financing rural water-supply programmes can best be developed by officials who have the most knowledge and experience of such work-the sanitary (public health) engineers and public health officials. Ifthese individuals who have a primary interest in this work do not take the lead in promoting and developing financial plans, little in the way of exe cution is apt to be accomplished.The stock reply to questions about financing is that the country, state, province, or community concerned is too poor to afford the cost of needed improvements. Upon investigation, however, it often turns out that public money is being spent for projects which are of much less importance and which cannot possibly give the same returns as those obtained when the same amount of funds is inn sted in the construction of public water supplies. There is usually a way to obtain long-range financing for rural water-supply programmes if the individuals concerned with the problem will look far enough for a good case to present to their legislators or to financial institutions. Long-range plans have been effective in many countries throughout the world, both in the Western and Eastern Hemi spheres. Most of them are the result of the work of a few people who have succeeded, after painstaking efforts, in convincing the right govern ment or bank of the importance of sanitation work.

General

Preliminary Investigation

Preliminary field studies and investigations are part of the duty of the engineer, who must possess, besides technical competence, diplomatic and persuasive ability to stimulate a strong interest among the members of the local community for the proposed project. The problems involved in these studies are in many ways as complex as those found in large, municipal, water-supply schemes. This stems from the fact that in develop ing the project the engineer must always compromise to a varying degree with regard to established standards of water quantity and quality. He is likely to be confronted with a great range of solutions between what he knows to be desirable and what appears to be possible. He must be careful not to produce either a fine project that is unrealistic or a realistic project which is completely inadequate from the point of view of the funda mental objectives previously discussed. He must explore every technically feasible scheme and must strive to find a sound Clnd economical solution, at the same time persuading the members of the community that it is in their interest to marshal funds for the water-supply project.A thorough and conscientious field investigation for a water supply isusually time-consuming and expensive, but it is one of the most important phases of the whole undertaking. An error at this stage can plague the entire operation of the project and, as history shows, can later cause irreparable damage to the water system or result in its total failure. On the other hand, it is in this phase that, by careful work, great savings can be effected, not only in original cost, but also in future operation and maintenance of the system.

Field equipment

The engineer should b : prepared at the outset of his investigations to determine the quantity and quality of water available from any possible source. He must therefore take along with him, or he should be able

Fig. 2. SIMPLE WATER-PROSPECTING EQUIPMENT*

A =TripodB = Sheave wheelCRopeD == To motor winchE = Drive hammerF = Jar lengthG = Drive headH = Rod couplingI= Drill rodJ =CasingK = Chopping bit (This maybe replaced with a sampler if desired The water swivel isthen replaced by a rod drive head.)

L = Casing drive headM = Rod drive headN """ Casing drive shoe0 = Lifting bailP = Water swivelQ =PumpR = Suction hoseS = TankT = Tee, replaced by drivehead when drivingcasing

*Both illustrations show simple equipment for making exploratory holes. Casing is driven into water-bearing formation, and cuttings are washed out. Undisturbed sam ples can be taken at necessary intervals.Well screens may be set in holes for test pumping when desirable.

Bacteriological quality

Water Quality

There is a direct relationship between the character and degree of pollution of raw water, the type and effectiveness of water-treatment pro cesses, and the character and quality of the treated water produced. Stream pollution-control agencies, in countries where these exist, normally take into consideration the limitations of water-treatment processes when they establish stream-water quality standards, so that the quality of treated water delivered to consumeis can meet prevailing drinking-water standards. The selection of a source of supply may be restricted because of economic or technical limitations involved in the use of normal water-treatment pro cesses for making the water from this source safe for human consumption.The effectiveness of a water-treatment process can hardly be establishedin specific, quantitative values. For instance, the bacteriological quality of a filtered, chlorinated water is dependent upon the bacterial content of the raw water; its chlorine demand; the coagulating, settling, and filtering characteristics of the treatment plant; the degree of uniformity of the raw water; and, not least, the integrity and ability of the treatment plant opera tor. Furthermore, the public health significance of the degree of bacterial pollution of a raw water, and hence of any bacteria remaining in the treated water produced, depends upon the probable source of contamination of the raw water with coiiform organisms, which serve as an indicator of pollution. These organisms may have originated .largely from snrface drainage, a situation likely to be most noticeable when manured fields are found within the watershed involved. On the other hand, sewage pollution may be the chief source of such organisms, in which case their public health signi ficance is enhanced and may be related to the incidence of intestinal diseases among the population contributing the sewage. Then, the probable ratio between the numbers of pathogenic organisms and of coliform bacteria in the polluted water will be considerably increased. Such conditions are often encountered in rural as well as semi-urban areas where intestinal diseases constitute a serious public health problem, the treatment of the sewage is not practicable, and effective water-treatment is beyond the eco nomic and technical resources available.

Chemical and physical quality

Water of good chemical and physical quality is necessary from the points of view of its acceptability by the people, the protection of the health of the consumer, and the conservation of the water system. Every technician experienced in rural water-supply work has encountered situa tions in which offending chemical substances have made a water source unacceptable to the public even though its bacteriological quality was excellent.Water containing amounts of carbonates and bicarbonates of calcium and magnesium in excess of 100 mg per litre is "hard" and requires a great deal of soap for washing clothes. In addition, it forms curds in combination with soap and leaves deposits on clothes and incrustations both in vessels in which it is heated and in distribution pipes and meters, thus reducing their capacity and even obstructing them completely. This constitutes a serious drawback in many rural areas where laundering is an important and widespread undertaking. Other salts (such as sodium chloride) in large doses can make water unpalatable and unfit for consump tion. The limiting dose, however, will vary from person to person or from one group to another. In certain areas of North Africa, for example, it is customaty for the local population to drink water containing as much as 3000 p.p.m. of chlorides, as sodium chloride." Such a concentration of salts would have a laxative effect on people not accustomed to it.

INSTALLATION OF VARIOUS TYPES OF WATER-SUPPLY SYSTEMS

GROUND WATER

Engineering and Geological Considerations

Ground water serves the great majority of people who live in rural areas and have a water-suppiy system of one type or another. The reason is that, among the various sources of supply, ground water is by far the most practical and safe in nature. Even in a highly industrialized country such as the USA, municipal ground-water installations far outnumber surface water supplies. It is very probable that, for a long time to come, ground water wm be the most important source of supply for most rural communi ties of the worid.The advantages of ground water are :(I) it is likely to be free of pathogenic bacteria;(2) generally, it may be used without further treatment;(3) in many instances it can be found in the close vicinity of rural communities;(4) it is often most practical and economical to obtain and distribute;(5) the water-bearing stratum from which it is drawn usually providesa natural storage at the point of intake.The disadvantages are:(1) ground water is often high in mineral content;(2) it usually requires pumping.In ground-water supply investigations and design, the engineer is con cerned with the following steps :(1}to find it in the required quantity and qualiLy as near as possibleto the centre of consumption, in order to reduce transport costs ;(2) to extract it by means of a system which produces the quantity required, safeguards the quality, and, at the same time, involves the least capital outlay;(3) to transport the water to the consumer in a way which requires the least amount of operational and maintenance skill and cost.

Fig. 4. GEOLOGICAL FORMATIONS

1 = Areas where there are good possibilities of obtaining water from infiltration galleries, well-point systemsl = Ground water is outcropping at this point, so that a flowing spring is formed. At the foot of riverbanks and hills other springs may possibly be found.3 = Top of ground-water table4 = Area of infiltration to supply formation BA = Non-confined (non-artesian), water-bearing formation covered with top- 1ilB = Confined (artesian), water-bearing formationC = Impervious rock, or hard-pan formationTo supply a village situated along the banks of the main river in this rolling country with a good ground water table, the first thing to look for is a spring above the town that could be developed and would flow by gravity. If no springs were found within a reasonable distance above the point of consumption, some might be found outcropping near the stream bed. If no springs were founc! within a reasonable distance, any well penetrating formation A would produce water. If large quantitie;:; were required, a well-point system or a gallery at points indicated would probably work. A deep well, properly constructed and developed, pene trating formation B would probably produce considerable water.The engineer making a survey of this area, knowing what is shown in this figure, ought to follow a pro cedure such as described above.

Fig. 5. OCCURRENCE AND DISTRIBUTION Of SUB-SURFACE WATER

SOIL WATERLimited to the soil and reached by roots

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z..:0.....

PELLICULAR WATERAdheres to rock surfaces throughout zone of aern- tion and is not moved by gravity but may be lr

z-0 stracted by evaporationE= ana transpiration

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