ENCYCLOPEDIA OF ENVIRONMENTAL SCIENCE AND ENGINEERING - PLANNING WATER SUPPLY AND SANITATION PROJECTS IN DEVELOPING NATIONS pptx

IN DEVELOPING NATIONS INTRODUCTION It is estimated that over 1.5 billion people in the world are without adequate water supply and waste disposal facili-ties.. 2 Concerned about the n

IN DEVELOPING NATIONS

INTRODUCTION

It is estimated that over 1.5 billion people in the world are

without adequate water supply and waste disposal

facili-ties. 1 Waterborne diseases kill an average of 25,000 people

every day, and millions suffer the debilitating effects of the

diseases. 2 Concerned about the need for safe water supply

and sanitation, the United Nations (UN) declared 1981–1990

as the International Water Supply and Sanitation Decade

with the professed goal of supplying potable water for all the

people of the world by 1990, and also of providing all people

with the means to safe disposal of human excreta This goal

was highly optimistic in view of the fact the nearly 80 percent

of the population in the developing countries does not have

access to piped water supply, and even a large percentage

lacks public sewers and household waste disposal systems. 3,4

At the end of the International Water and Sanitation

Decade, it was estimated that almost 31 and 44 percent of the

world population was lacking safe water supply and adequate

human waste disposal, respectively The global population

being 5.28 billions, total population currently having

inad-equate water supply and sanitation is therefore staggering. 5 – 7

Based on an assessment of the successes and failures of the

Decade, it is believed that much has been accomplished, but

progress is needed on all fronts: rehabilitation and operation

of existing systems, training of personnel, financing, and

new construction to achieve the goals of the Decade within

a reasonable time in the future In this article many factors

that contribute to successes and failures of the Water Decade

goals are reviewed The discussion is divided into (1)

under-standing of the needs, (2) appropriate technology for water

supply and waste disposal, (3) commitment, (4) financial

resources, (5) training of people to plan, design, build,

oper-ate and maintain woper-ater and sanitary projects, and (6) role of

developed nations. 8 – 10

UNDERSTANDING THE NEEDS

Adequate supply of safe water and basic sanitation are the

foundation of health Water pollution and poor sanitation

are probably responsible for 80 percent of the morbidity

and mortality in the developing countries It is estimated

that over 900 million cases of diarrhea related illness occur

each year, resulting in the death of over 3 million

chil-dren Common diseases associated with polluted water are

11 Prevention of such diseases depends on the improvement of the quality of the water supply, personal hygiene, food handling and preparation; as well as the provi-sion of adequate sanitation, including sanitary facilities for human waste disposal

The importance of personal hygiene specially on the part

of mothers and children is the key to beneficial results in dis-ease prevention Therefore, more intensive activities directed

to improve personal hygiene should be emphasized in the developing countries Furthermore, a meaningful program

of providing safe water supply in developing countries must also include safe disposal of human excreta, basic education, and improvement of sanitary conditions

The major constraints on the progress of the International Drinking Water Supply and Sanitation Decade have been operation and maintenance and rehabilitation of the systems that were built earlier Broken-down and poorly functioning facilities waste money, are a threat to health, and discourage future investments Also, inappropriate technology is at the root of many water supply and waste disposal problems in the developing countries. 12,14

APPROPRIATE TECHNOLOGY

Water Supply

The goal of the UN Water Decade was to provide “clean water and adequate sanitation for all by 1990” It should be noted that this did not mean a tap and a flush toilet in every house Reasonable access to safe water is usually understood

to be within 500 m of the household; for many developing countries, adequate sanitation probably refers to some tech-nology intermediate between the water flush toilet and the simple pit latrine The scope of the task of the UN Water Decade was truly enormous considering that the two pri-ority areas are the rural population (71%), who often have

to travel long distances for water, and the crowded urban poor (25%), for whom water supply often is grossly inad-equate; 87% of rural population and 47% of urban fringe areas lack adequate sanitation. 12 Naturally, achieving uni-versal coverage would mean not only supplying almost one billion people currently without safe water supplies and the 1.7 billion people without sanitation, but matching popula-tion growth as well Annual investment is currently in the range of 15 to 20 billion dollars per year—about 2 to 3 per-cent of gross investment in developing countries If the share grouped in Table 1

remains constant over the next fifteen to twenty years,

eco-nomic growth will allow investment to double in real terms,

to 30–40 billion a year. 13 Therefore, selection of appropriate

technology and service levels must be established in

bring-ing down the capital costs of water supply and sanitation

projects It was also demonstrated in the first half of the

Decade that the biggest priority is correcting the inadequate training of the operating personnel. 14

Selection of appropriate technology for use by the devel-oping countries requires (1) understanding of the cultural background, regional environmental conditions, and local needs; (2) selection of appropriate systems that will be within

TABLE 1 Common disease associated with contaminated water and poor sanitation

Water-borne diseases

Amoebic dysentery Bacillary dysentery Cholera

Criptospridiosis Gastroenteritis Giardiasis Hepatitis Leptospirosis Paratyphoid fever Salmonellosis Typhoid

Diseases transmitted by ingesting contaminated water and food

Water-washed diseases

Conjunctivitis Hookworm (Ankylostoma) Leprosy

Scabies Skin sepsis and ulcers Trihcuriasis Whipworm (Enterobius) Yaws

Lack of adequate quantity of uncontaminated water, and poor personal hygiene create conditions favorable for their spread

Water-based diseases

Bilharziosis Dracunculosis Oncholersosis Philariosis Schistosomiasis Treadworm

Diseases caused by infecting agents by contact with or without ingestion of water An essential part of the life cycle of the infection agent takes place in

an aquatic animal

Fecal-disposal diseases

Clonorchiasis Diphyllobothriasis Fasciolopsiasis Paragonimiasis

Diseases caused by infecting agent mostly contracted by eating uncooked fish and other food

Water-related vectors

Arbovirus Bancroftian Dengue fever Encephalitis Filariasis Hemorrhagic fever Malaria

Diseases transmitted by insects which live and breed close to water Infections are spread by mosquitoes, flies, and insect bite

Adapted in part from Ref 11.

the financial (minimizing initial investment cost as well as

maintenance cost) and technical (minimizing operational

failures) resources; (3) training paraprofessional rural water

technicians (using available labor where possible instead of

expensive imported equipment); (4) promoting

complemen-tary activities to help people to obtain the most benefits from

the systems (so that users will receive long-term benefits of

these basic services); and (5) selection of the most

appropri-ate wappropri-ater source and the most appropriappropri-ate energy source for

conveying water to its users

The different sources of small community water supply

systems in developing countries can be categorized as

fol-lows: (1) groundwater, (2) rain water, (3) springwater, and

(4) surface water Depending on the sources of water supply,

many techniques have been found effective and applicable

to the water and sanitation programs in the developing

coun-tries Some of these techniques are presented below

read-ily available at moderate depth, constructing a number of

wells fitted with hand pumps is by far the cheapest means

of providing a good water supply. 14 Although, community

water systems piped under pressure to households and public

standposts may be an ultimate goal, many areas will

realisti-cally have to seek hand pumps as an interim if not an

ulti-mate measure The trouble with most hand operated water

pumps used in developing countries is that they are not hardy

enough and require frequent maintenance Pump parts are

usually expensive to buy and are difficult to make locally

to fit the pump Development work started at the Consumer

Research Laboratory (CRL) in England has led to the snappy

plastic pump: a simpler, cheaper and hardier device that has

many beneficial features A complete description of such

hand pumps is given by Sattaur. 15 Additional information on

other types of hand pump manufactured in developing

coun-tries may be found in Ref 15 Hofkes provides some other

techniques and methods of groundwater withdrawal used by

small water supply systems in developing countries. 11

Rainwater In developing countries rainwater is

some-times used to supplement the other water supply sources In

some tropical islands rainwater is the only source of domestic

water supply Rainwater harvesting requires adequate

provi-sion for the interception, collection and storage of the water

Generally, cisterns are built to collect the runoff from the

roofs Water quality preservation is very important and some

basic measures should be followed to exclude bird

drop-pings, insects and dirt from the stored water Also, storage

in cool conditions, exclusion of light, and regular cleaning

is essential Simple disinfection devices may be very useful

Rainwater catchments are relatively simple to construct

and maintain It is expected that these systems will be widely

used in the future In Kenya, concrete jars used as storage

tanks are said to be the most popular appropriate technology

Their popularity is growing among the villagers in Thailand

where the construction and maintenance of these units is

undertaken by technicians of the Sanitation Division of the

Department of Health The technician directs the voluntary

labor of villagers in constructing concrete storage tanks

rein-forced with bamboo The Villagers then repay the costs of

the tanks in 12 monthly installments The owners of these tanks, having contributed so much of their time and money into their construction are usually very keen to operate and maintain it properly. 16 Design details and economics of many cisterns, storage tanks, and other rainwater harvesting systems may be found in Refs. 17 – 21

Spring and Surface Water There are many situations in

the developing world where water is available from a nearby stream or spring Various devices have been constructed to utilize the energy available in flowing streams to pump the water to the point of use

The more successful devices, that will represent substan-tial savings in pumping water are the hydraulic ram pumps (hydram) and low-head turbine pumps One converts pres-sure energy to mechanical work and the other converts kinetic energy to mechanical work These two practical devices have been described and compared in detail by Schiller. 22 He observed that the hydram is easier to operate and maintain, but installation of the turbine pump is easier and simpler

Before the Water Decade program started the water qual-ity control was given least importance in developing coun-tries Perhaps, the major reason was inappropriate operation and maintenance of the equipment The primary goal of any water project started in the Drinking Water Decade was to provide a facility and system that can be operated, maintained and managed at local levels giving self sufficiency with proper personnel and financial needs. 23 Local capabilities for operation and maintenance must be developed through training local maintenance personnel, establishing a locally managed maintenance fund, selecting an easily maintained technology, and requiring capital contributions from the community to increase local sense of ownership and respon-sibility for the systems. 24 Finally, a successful drinking water program requires extensive local participation (materials and labor) and minimize dependence on overseas materials and equipment for construction and operation of facilities. 25

Human Waste Disposal

Rapid growth of the urban populations (mainly because of migration from rural areas) has led to severe problems in providing human waste disposal systems Only 32 percent

of the population in the developing countries is directly con-nected to sewer systems Therefore, the collection and dis-posal of human wastes constitute a serious environmental and health problem. 26 Several alternatives are available; each has its own limitations and constraints Certainly there is

no single option appropriate to all situations The range of options described below is sufficient to cover the vast major-ity of the situations within the low income communities of the developing countries

One of the fundamental principles of community sanita-tion is to remove all putrescible matter, particularly human wastes A satisfactory excreta disposal method must satisfy the following requirements: 26

1) Should not be accessible to flies or animals 2) Should not cause odors or unsightly conditions

3) Should be simple and inexpensive to construct

and operate 4) Should not cause ground water or surface water

contamination 5) Should not cause soil contamination

The appropriate technology for human waste disposal in

developing nations fall into two major applications (1) rural,

and urban areas without sewers, and (2) urban areas having

municipal sewers Appropriate technology for each of the

above applications are discussed below:

Rural and Urban Areas without Municipal Sewers

The environmentally acceptable methods of human waste

disposal in rural areas include various types of sewerless

composting toilets Common examples of such toilets are

bored-hole latrine, pit privy, vault privy, septic privy,

chemi-cal toilet, soil or composting toilet, methane forming toilet,

and box-and-can privy. 26,27 These devices are simple and

inexpensive to build and operate Each of these devices is

briefly discussed below

Bored-hole Latrine: Bored-hole latrines consist of a hole

in the ground 25 to 60 cm in diameter, and 2 to 3 meters deep

The hole may be braced to prevent it from caving A concrete

slab with a hole cut in it may be placed over it, and the entire

assembly is made into an outhouse When the hole is filled,

the structure is moved to another hole Fly and odor problems

are controlled by keeping the hole covered, and dropping dry

soil in the hole on a regular basis Deep bored-hole latrines

present danger of ground-water pollution. 26

Pit or Vault Privy: Pit or vault privies can serve the needs

of homes, schools or groups of homes A concrete pit or vault

is constructed in the ground and a toilet seat is located on

the top The seat cover must be kept closed to prevent flies

from entering Odor is a problem A vent pipe raised over the

roof has been helpful in odor control In 3 to 4 months when

the pit or vault becomes full, there is the unpleasant job of

cleaning it Some vaults have two compartments When one

compartment is full it is kept closed for 2 to 3 months while

the other side is used During this time, the excreta is

decom-posed, and cleaning becomes less objectionable Pit or vault

privies with separate back covers have also been used These

back covers help in the cleaning operation. 26

Septic Privy: Septic privies utilize a liquefying tank

similar to a septic tank The waste is digested and overflow

may be discharged into a percolation field The toilet has a

shallow trap After use the toilet must be flushed by pouring

2 to 3 liters of water. 26

Chemical Toilet: Chemical toilets consist of a tank in

which waste accumulates The toilet seat is provided directly

over the tank Caustic soda (sodium hydroxide (NaOH))

is most commonly used to kill the bacteria and to liquefy

the wastes The caustic soda dosage is 1 to 2 kg of sodium

hydroxide per month for a family of four The tank is emptied

periodically If caustic soda is used the tank contents can be

carefully applied over farming land Many types of chemical

toilets are available from various manufacturers. 26,28,29

Soil or Composting Toilet: This is dry toilet capable of

being used indoors The toilet consists of a wooden frame

with toilet seat, and a bucket lined with a plastic bag The toilet is started with a layer of dry soil 10 to 15 cm deep

Users must sprinkle several scoops of soil after each use

Once or twice a week, the bag is removed, tied and stored

After a decomposition of several weeks the contents are spread over farm land. 30

A more involved is the Clivus Multrum composting

toilet This toilet was developed and has been successfully used for some time in Sweden and is now manufactured

in the United States. 31 The toilet is capable of composting toilet waste, kitchen wastes, and even leaves and grass It has three sloping chambers and is started with a layer of peat moss four to five inches thick Design and operational details

may be obtained in Ref 31 Another toilet similar to Clivus

Multrum toilet is the Toa-Throne compost toilet also

devel-oped in Sweden

Another dry composting toilet that has been proven highly successful in Vietnam, offers a suitable system for all developing nations. 32 The toilet consists of two-holer outhouse in which only one hole is used at any one time

There is no raised seat, instead each hole is placed in a squat-ting plate at floor level The urine flows out and soaks into the ground outside the outhouse The fecal wastes go into the other hole The user must drop dry soil or ash after use

When the toilet is two-thirds full, the rest is filled with soil, and the vault is tightly sealed The other side is started After

a composting period of approximately 45 days the contents are taken out and used over the farm as rich compost. 33,34

Methane Farming Toilet: In India small biogas plants are

extensively built in rural areas These biogas plants anaero-bically digest animal manure and other organic wastes, and the methane is used to light, heat, and power the farms

Singh gave the basic design and construction details of such toilet. 34 Other designs of anaerobic digesters utilizing human, animal and other organic wastes are used in Kenya and Brazil. 35 – 37 Morris developed a package unit for meth-ane generation from human wastes. 37 Khandelwal provided design and operational details on dome-shaped biogas plants used in India. 38 Eusebio and Rabino provided design of large biogas plants used in Philippines, India and Africa. 39

Box-and-can Privy: The toilet system consists of a

wooden box, the lid and toilet seat The can or pail is remov-able through the top or side of the box The cans are removed manually under regular scavenger service, emptied, cleaned, and replaced This system is most commonly used in cities that do not have a sewerage system

This type of system is associated with odors and serious fly problems if the lids are not tightly closed after use For satisfactory operation there should be a regular scavenger service, preferably under a governmental supervision with ordinances covering types and size of box and can, method

of emptying and cleaning of the cans, and ultimate disposal

of the human waste A speedy and convenient way is to use identical toilet boxes and cans for the entire community The scavengers remover the can and place it in his vehicle without emptying, and replacing a clean can The vehicle when full is taken to a central disposal facility for emptying, and replac-ing with clean cans The disposal facility should be located in

a remote area and should utilize anaerobic digesters whereby

the recovery and sale of methane gas, and digested sludge as

soil conditioner can be achieved The central disposal

facili-ties should be equipped with running water, hose, and

chemi-cal solution for washing and cleaning the cans

Experience has shown that such systems based on

pay-ments by the residents to private scavengers have been

unsat-isfactory The service is poor, irregular and wastes may be

dumped uncontrolled upon land and in waters

The box-and-can system should be used only as a

tempo-rary means of waste disposal with continued effort to replace

it by other more acceptable methods Furthermore, it should

be carried out only under the supervision of trained

person-nel and under strict governmental control

Urban Areas with Municipal Sewers The wastewater

collected through municipal sewers contains large volumes of

water Therefore, treatment technology is much more complex

than discussed above Treatment schemes to achieve

second-ary level of treatment (90% organics and total suspended solids

removal) include screening, grit removal, primary

sedimenta-tion, biological treatment (activated sludge or trickling filter),

final clarification, and disinfection Other physical, chemical

and biological treatment processes may be added to remove

phosphorus, nitrogen, and additional organics and suspended

solids The solids fraction (sludge) is digested aerobically or

anaerobically

Although, such treatment technology may be desirable

for the developed nations, their use in developing nations

may not be appropriate Such treatment processes are costly

to build, and complex to operate Desirable treatment

meth-ods for developing nations may include the following:

1) stabilization pond followed by effluent reuse on

farming lands, 2) Imhoff tanks followed by stabilization pond and

effluent reuse on farming land, and 3) upflow anaerobic sludge blanket process

Imhoff tanks provide primary sedimentation, and

anaero-bic digestion of settled sludge The methane is collected for

energy source and digested sludge is used as compost The

stabilization pond (oxidation pond or lagoon) is an earthen

basin that retains the wastewater for sufficient time to stabilize

the organic matter, and destroy large percentage of pathogens

The effluent is used for irrigation, or discharged into

natu-ral waters. 40 – 43 The upflow anaerobic sludge blanket process

(UASB) was developed in Netherlands and is extensively

used and tested in the developing nations. 44 In this process the

wastewater enters the bottom of the reactor and percolates up

through the sludge blanket where organics are converted to

methane and carbon dioxide by anaerobic organisms The gas

is collected, and treated effluent is drawn off from the top. 34

COMMITMENT

The water supply and sanitation schemes in developing

countries cannot be successful without the willingness of

the government to commit the resources to undertake water supply and sanitation projects Unfortunately, the govern-mental priority in this area is quite low Most of the develop-ing countries set their priorities as follows: (1) agriculture, (2) industries, (3) energy resource development, (4) educa-tion, (5) commerce and transportaeduca-tion, (6) family planning, (7) housing and urban development, and (8) water supply, and sanitation, and environmental control. 45 Such priorities have been set on account of necessities It is necessary that the developing countries give needed priority on water and sanitation

FINANCIAL RESOURCES

The success of any program in any country depends upon the financial commitments of the respective governments

Developing nations (except for the oil exporting nations) are poor and have very limited funds A 1975 study indi-cated that villagers if they have to pay more than 50 cents per month for water supply, they would not participate in the program. 45 Their ability to pay for water and sanitation

is very limited Success of the program will depend upon outside funds, and local labor

TRAINING AND MANPOWER DEVELOPMENT

It is well recognized that the success of any program requires well trained people Unfortunately, past experience has shown that many internationally supported training pro-grams were not successful because the emphasis was incor-rectly placed Engineers from developing nations when trained in the western world generally learn the theory and design of most sophisticated unit operations and processes

in water and wastewater treatment and environmental engi-neering When they return to their countries, they are gen-erally eager to utilize such technologies, although in most cases these may be quite inappropriate Furthermore, for-eign consultant’s unfamiliarity with the cultural and operat-ing competence of the people in developoperat-ing countries have resulted in selection and design of technology that have not functioned

What is really needed is a program where training at all levels may be effectively provided The includes training of central government officials and engineers; local govern-ment officials, residents and technicians; on-the-job training

of operators; and users education Government officials set the priorities and make funding decisions Engineers have responsibility to evaluate, select and implement the appro-priate technology Local officials participate and support the program The technicians and operators have the responsibil-ity for continued operation and maintenance of the system

And finally, users education is essential as they are the ulti-mate beneficiary

In order to effectively provide such a complex training opportunity, programs must be developed in the develop-ing nations Such traindevelop-ing programs must be developed as

academic programs, short courses, seminars, and internships

to address different audiences yet meet the specific needs of

each Brief discussion is given below

Academic Programs

Academic programs include regular undergraduate and

graduate programs at universities, and technology or

voca-tional programs in polytechnics and colleges Both programs

have different objectives

University Programs Regular academic programs such

as master’s and bachelor’s degrees in civil, sanitary or

envi-ronmental engineering, biology, public health, and so on

have been modeled along the lines of western universities

These programs often may not be directly applicable to the

needs of the developing nations It is necessary to modify or

develop new programs tailored for their national needs As

an example, graduates in civil, sanitary or public health

engi-neering must also know community interactions,

socio-eco-nomic implications, relationships between service levels and

health and well-being, that dictate the success or failure of

any water supply and sanitation projects, especially in rural

and urban settings of developing nations

Technology Programs The technology or vocational

programs should be directed towards training technicians,

health inspectors, and community workers Specialized

train-ing is needed so that these personnel can undertake field work,

organize the community, conduct training, and assist the

com-munity in the selection and installation of water supply and

sanitation facilities, and provide continued operation and

maintenance of such facilities Special training is needed for

personnel to motivate people and implement the programs in

rural areas where approximately 75% of the population lives

Short Courses and Seminars

In corporation with the health ministry specialized short

courses of one- or two-week duration should be conducted at

universities, colleges, and high schools These short courses

should be designed to provide training to full-range of

people including decision makers, engineers, operators and

community workers

Decision Makers The government officials who have

the responsibility for setting up priorities, and allocation

of funds must be aware of the relationship between service

levels and health and other benefits, cost of construction and

operation, and short-range and long-range implications of

the investments in water supply and sanitation projects

Engineers and Designers The intensive short courses

designed for engineers and designers should cover the

suc-cesses and failures of different projects, improvements

needed in future systems, public education, and how to relate

health conditions and project objectives in order to develop

the most cost-effective system for the specific conditions

Operators and Community Workers Intensive short

courses should be conducted for operators and community

workers in basic topics ranging from chemistry, biology,

vec-tors, communicable diseases, to metal working, equipment

repairs, operation and maintenance, leak repairs, book keep-ing, to management of public works projects

On-the-job Training On-the-job training programs

of varying periods with or without short courses should be developed to train field workers and inspectors and local people in construction techniques and operation of water supply and sanitation systems Such practical training can

be a powerful tool for manpower development

Primary Health Care Workers Health education or sanitation education should be provided at village level

Villagers, literate or illiterate, should be trained as primary

health care workers, or barefoot doctors, whose training

should be emphasized on prevention, and curative care Six

to 12 months intensive training could be provided at local high schools or through health education service

Users Education Training of villagers in water supply

and sanitation must also be provided as part of user or adult education program This can be achieved by mass campaigns

by health education extension services Health education must also be instituted in primary schools This will provide the broadest, and most dependable coverage to younger groups

The program must include community sanitation; hygiene habits in home; fly rodent and other vector control; water con-tamination and use of water supply devices; and proper use and maintenance of various types of privies and latrines

Training and Educational Material, and Education of Trainers

It is important that training, educational and technical material should be in the form of posters, technical books, manuals, photographs, slides, films and audio-visual aids

Audio-visual equipment has been highly successful in train-ing personnel, and illiterate population in rural areas A porta-ble power generator may be necessary for rural areas without electrification

Educational material must be carefully prepared for the specific audience General health related material covering disease transmission, vector control, water and food pro-tection, personal hygiene, should be prepared for general public with no education Information on public use of water supply and sanitation devices should also be prepared for general audience Technical and semitechnical information should cover the design and construction; and operation and maintenance of different types of water supply and sanita-tion devices presented earlier in this paper

The other most important of all training program activi-ties is the selection and training of instructors or trainers

Technicians and supervisors should be trained so that they can teach their colleagues, subordinates or interns on the job

Education of trainers should be provided in schools, through short courses, audio-visual aids, and job training

ROLE OF DEVELOPED NATIONS

Developed nations can play a major role in helping the developing nations to achieve the original goals of the UN

Water Decade The assistance may come in the form of

fund-ing of the international agencies (UN, World Bank, etc.) and

international development agencies in their own countries

The technical assistance and transfer of know-how can

also be achieved in the form of advisory services to the

gov-ernments, utilities, and institutions The assistance can be

provided by short-term and long-term consultants for on-job

training, development of educational material, and training

of personnel and manpower development

REFERENCES

1 Kalbermatten, J.M and F.W Montanari, Water for the world: The

scope of the challenge, Journal American Water Works Association,

June 1980, p 308

2 Muyibi, S.A., Planning water supply and sanitation projects in

devel-oping countries, Journal of Water Resources and Management, 118,

July/August 1992, pp 351–5

3 Rao, S.V.R and John A Rasmussen, Technology of small

commu-nity water supply systems in developing countries, Journal of Water

Resources Planning and Management, July 1987, p 485

4 Witt, Vicent M., Developing and applying international water quality

guidelines, Journal American Water Works Association, April 1982,

p 178

5 Anonymous, Human Development Report 1991, UNDP, Oxford

Uni-versity Press, New York

6 Rural water supply, World Water and Environmental Engineer, June

1990, p 46

7 Theme Interaction, World Water, Journal American Water Works

Asso-ciation, June 1988, p 33

8 The World Bank, “Development and the Environment”, World

Devel-opment Report 1992, Oxford University Press, New York

9 Churchill, A., Rural Water Supply and Sanitation: Time for a Change,

World Bank Discussion Paper no 18 Washington, D.C 1988

10 Bris, J and D de Ferrantis, Water for Rural Community: Helping

People to Help Themselves, World Bank, Washington, D.C 1988

11 Hofkes, E.H., Small Community Water Supplies, Technology of Small

Water Supply Systems in Developing Countries, John Wiley & Sons,

Great Britain, 1983

12 Schiller, E.J., The United Nations Water Decade and North American

Engineers and Planers, Chapter 1, Water Supply and Sanitation in

Developing Countries, Ann Arbor science, 1982

13 The World Bank, “Development and the Environment”, World

Devel-opment Report 1991 Oxford University Press, New York

14 Wolman, Abel, The next five years, Journal American Water Works

Association, June 1985, p 12

15 McJunkin and E.H.A Hofkes, Hand-Pump Technology for the

Devel-opment of Groundwater Resources, Chapter 4, Water Supply and

Sanitation in Developing Countries, Ann Arbor science, 1982

16 Sattaur, Omar, Developing countries switch to sanappy plastic pumps,

New Scientist, November 26, 1987, p 36

17 Schiller, E.J., Rooftop Rainwater Catchment Systems for Drinking

Water Supply, Chapter 7, Water Supply and Sanitation in Developing

Countries, Ann Arbor Science, 1982

18 Grover, B., Harvesting precipitation for community water supply,

World Bank, Washington D.C., 1984

19 Maddocks, D., An introduction to methods of rain water collection and

storage, Appropriate Technology, 2, No 3, 1975, pp 24–25

20 Maddocks, D., Methods of creating low cost membranes for use in the

construction of rainwater catchment and storage systems, Intermediate

Technology Publications, Ltd., London, 1975

21 Watt, S.B., Rainwater storage tanks in Thailand, Appropriate

Technol-ogy, 5, No 2, 1978, pp 16–17

22 Schiller, E.J., Renewable Energy Pumping from Rivers and Streams,

Chapter 5, Water Supply and Sanitation in Developing Countries, Ann

Arbor Science, 1983

23 Austin, John H and James K Jordan, Operation and maintenance of

water systems in developing countries, Journal American Water Works

Association, July 1987, p 70

24 Karp, Andrew W and Stephen B Cox, Building water and sanitation

projects in rural Guatemala, Journal American Water Works

Associa-tion, April 1982, p 163

25 Monk, Robert, Terry Hall, and Mohammed Hussain, Real world

design: Appropriate technology for developing nations, Journal

Ameri-can Water Works Association, June 1984, p 68

26 Ehlers, V.M and E.W Steel, Municipal and Rural Sanitation,

McGraw-Hill Book Co., NY, 1965

27 Ports, D.D., What’s in the future for composting toilet, Compost

Sci-ence, Journal of Waste Recycling, 18, No 4, July–August 1977, p 16

28 Qasim, S.R., Onsite wastewater treatment technology for domestic

waste and special applications, The encyclopedia of Environmental

Sci-ence and Engineering, Gordon and Breach, SciSci-ence Publishers, Inc

New York, Third Edition, 1991, pp 813–21

29 Clark and Groff Engineers, Sanitary waste disposal for navy camps in

polar regions, Final Report on Contract NBY-32205, Salem, Oregon,

May 1962

30 Leich, H.H., UN ignore waterless sanitation devices, Compost Science,

Journal of Waste Recycling, 18, No 3, May–June 1977, p 7

31 The Clivus Multrium Composting Toilet, Compost Science, Journal of

Waste Recycling, 15, No 5, Nov.–Dec 1974

32 Jounge, L.D., The Toa-Throne- A new compost toilet, Compost

Sci-ence, Journal of Water Recycling, 17, No 4, Sept.–Oct 1976

33 Leich, H.L Sanitation for the developing nations, Compost Science,

Journal of Waste Recycling, 18, No 5, Sept.–Oct 1977

34 Singh, R.B., Building a biogas plant, Compost Science, Journal of

Waste Recycling, 13, No 2, March–April 1972, p 12

35 Methane farming in Kenya, Compost Science, Journal of Waste

Recy-cling, 13, No 5, Nov.–Dec 1974, p 15

36 Company formed to advice our methane plant, Compost Science,

Jour-nal of Waste Recycling, 15, No 5, Nov.–Dec 1974, p 15

37 Morris, G., Methane for home power use, Compost Science, Journal of

Waste Recycling, 14, No 6, Nov.–Dec 1973, p 11

38 Khandelwal, K.C., Dome-shaped Biogas Plant, Compost Science,

Jour-nal of Waste Recycling, 19, No 2, March–April 1978

39 Eusebio, J.A and B.I Rabiino, Research on biogas in developing

coun-tries, Compost Science, Journal of Waste Recycling, 19, No 2, March–

April 1978

40 Metcalf and eddy, Inc., Wastewater Engineering: Treatment, Disposal

and Reuse, 3rd Edition, McGraw-Hill Book Co., New York, NY., 1991

41 Viessman W and M.J Hammer, Water Supply and Pollution Control,

4th Edition, Harper & Row, Publishers, NY, 1985

42 Qasim, S.R., Wastewater Treatment Plants: Planning, Design and Operation, Technomic Publishing Co., Lancaster, Pa., 1994

43 Thery, Daniel, The biogas programs in India and China Resource

Man-agement and Optimization, 1, No 4, Oct 1981, Harwood Academic

Publishers, NY

44 Anaerobics attack tropical wastewaters, World Water, August 1988,

p 31

45 Dallaire, Gene, UN Launches International Water Decade, US role

uncertain, Civil Engineering, American Society of Civil Engineers,

March 1981, p 59

SYED R QASIM

The University of Texas at Arlington