Why Applied Research?
Case study examples of applied research in the water supply and sanitation
Manual Pit Latrine Emptying Technology Project (MAPET)
Siaya Health, Education, Water and Sanitation Project (SHEWAS)
Moringa Oleifera as a Natural Coagulant
Engineering, Mosquitoes and Filariasis
The Latrine Project, Mozambique
Why Applied Research? The World Bank estimates that, at current rates of progress, the number of people without adequate water and sanitation will double over the next forty years. To some, these statistics may suggest we cannot afford research in a world of acute human need. Research takes money away from the practical work of providing basic water and sanitation services; how can we do this when practice is falling behind?
Actually, we need good applied research precisely because practice is falling behind. Very simply, we need new methods to succeed where current ones are failing. Applied research (AR) is the process by which we gain practical insight into problems, and develop fresh approaches to solving them; it is thus an essential tool to make the most of limited resources. Without good AR, we will continue to spend money on expensive and inappropriate 'solutions', simply because we have not developed and tested alternatives.
What is good applied research? Good research may be difficult to define, but easy to recognise. Good AR looks at real-world problems and moves towards their solution through increased understanding and the development of new approaches. The examples in this document show good AR in water and sanitation to be very different from conventional scientific research. While technology plays an important role, it is most often the human factor which determines success or failure in promotion of water and sanitation. Good AR in water and sanitation must therefore reflect such human issues as acceptability, cost, risk, maintenance, and institutional viability. Research is thus needed in the community as well as in the laboratory, and often involves the participation of affected individuals, communities and professionals.
One of the hallmarks of good AR is that it simply makes sense. The examples in this document address basic practical issues of how to:
- learn about water use before planning interventions,
- use local resources in treating water,
- prioritise interventions to control mosquito vectors,
- reduce the cost and increase the construction of latrines,
- manage the contents of full latrines safely.
All of these are real-world problems, and much project money has been wasted in the past without good answers to them. While the questions may sound simple, finding answers is not. Good AR achieves practical rigour in providing hard data where ignorance, untested assumptions and guesswork have ruled too long, cost too much money, and provided 'answers' that do not work.
Current mechanisms to promote good applied research are inadequate. Traditional academic and governmental funding bodies favour either pure research, or AR with commercial potential. Water and sanitation should profit from both, but most good AR in water and sanitation falls outside these areas.
More funds are thus needed to develop AR, and improve its quality. After all, experience shows that continued ignorance is a lot more expensive than understanding.
Lecturer, Environmental Health Programme, London School of Hygiene and Tropical Medicine
Dar es Salaam, TANZANIA
Dar es Salaam Sewerage & Sanitation Department (DSSD) & WASTE consultants
In many developing country cities, pit latrines provide the principal means of excreta disposal. Emptying these pits when they are full can present major operational problems. This project developed a locally manufactured systems which was easily manoeuvrable in densely populated urban areas and did not rely on fossil fuel. The system is operated by a team of three, who are self-employed and negotiate a price with the customer; five teams are currently operational.
This applied research project has resulted in the introduction and increased use of improved hygienic pit emptying practices. The equipment is manufactured and maintained using only locally available resources, and the operators earn a wage from providing the service privately to their customers.
In many developing country cities, the incidence of a piped sewage system is restricted to a small percentage of the population: the vast majority use on-plot sanitation for excreta disposal. The city of Dar es Salaam, Tanzania, is no exception, with 80 per cent of households using pit latrines.
Although many pit latrines are built with large capacity (10m3 or more) most fill within five years of use, at which time they pose a threat to the environment and public health. Although in theory households are supposed to dig a new pit to replace the full one, the dual constraints of small plot size and lack of money means that in practice, the full pit has to be emptied.
Emptying pit latrines constitutes a long-term operational and hygiene problem for most low-income households. Traditional practices rely on manual labourers desludging pits by hand - a process that is time consuming (2-7 days during which time there are no household excreta facilities), unhygienic (labourers come into full contact with pit sludge), and expensive (labourers costs and pit rebuilding). More technological solutions such as vacuum tankers have their own limitations: many cannot negotiate the narrow, unpaved roads in densely built, unplanned areas; and the high cost and spares shortages frequently makes the vacuum tanker an inappropriate choice for excreta disposal. Furthermore, the City Council's ability to undertake pit emptying responsibilities is seriously impeded by maintenance and personnel problems.
In response to these problems, the Netherlands Ministry of Development Co-operation financed a project between 1988-1992 to develop appropriate pit emptying technologies suitable for low income, unplanned urban areas in Dar es Salaam. The dual objectives for the project included:
- Contribute to the improvement of environmental sanitation in unplanned areas by facilitating an effective and hygienic pit emptying service;
- Contribute to the informal traditional pit emptying methods through efficiency and hygiene improvements
The way in which these objectives were achieved was through a combination of four project approaches including:
(i) participatory development and technology introduction;
(ii) reliance on technologies already familiar to small local workshops;
(iii) pit emptying as a means for income generation; and
(iv) intermittent presence of consultants and expertise at the Dar es Salaam Sewerage and Sanitation Department
The design criteria were driven by the need to meet several critical objectives: that the equipment did not rely on fossil fuel; that it could be small enough to be pushed through unplanned urban areas; and be manufactured locally with available expertise, tools and materials. The subsequent design process led to the development of MAPET technology based on:
- a piston handpump mounted on a pushcart;
- a 200 litre vacuum tank mounted on a pushcart;
- a 3/4 inch air hose pipe between the pump and tank, and a 4 inch sludge hose pipe of 4 m length to drain the sludge from the pit;
- Auxiliaries such as sludge mixing rod, spade, hook, hoe, etc.
Good design included provision for maintenance through construction techniques which were generally known and familiar in large and small scale workshops throughout Tanzania. The training of personnel to maintain and repair MAPET components was considered a high priority, adding to the sustainable nature of the project.
Typically, a team of MAPET emptiers consists of three men, each of whom is self-employed. Each team is responsible for the continuity of its activities and income. As a team they decide how to co-operate in order to share the work they have. Each team works full time and depends on its own efforts to find customers.
The emptying process begins with a team member making contact with a customer and negotiating a price. Unit prices are normally set a standard charge per tank load. Customers then have the flexibility to empty their pit according to their ability to pay. The average charge for a tank load in 1992 was $2.5; the average job normally taking five tank loads, which means that each team earns $12.5 per customer, and $87 per month. The estimated subsistence level in urban Dar es Salaam in 1992 was $75 per month.
Having set a price, the MAPET team decide where to bury the latrine sludge on-plot (if this is possible). A hose pipe is inserted into the squatting hole and connected to the handcart. The tank cart is connected to the handpump with an air hose, and air is pumped out of the tank. The resulting vacuum causes the sludge to be sucked into the tank. When the tank is full, the hose pipes are disconnected and the tank moved to the burial hole. A pressure release valve is opened when the tank is in position and the sludge is then discharged into the hole. Once empty, the tank can be put back in its original position and the routine can be repeated until the required amount of sludge has been removed.
Digging the burial hole constitutes most of the team's work and typically lasts more than an hour; filling the 200 litre tank takes an estimated five minutes, depending on the viscosity of the sludge. Customers generally ask for 4-10 tanks to be taken out of their latrine.
In Dar es Salaam, the practice of burying sludge on-plot is socially acceptable providing that the process of emptying and burial is hygienic and the sludge is covered properly. There are two situations where sludge cannot be buried on-plot: (i) when there is insufficient space; and (ii) when there is a high groundwater table.
To cater for these eventualities, WASTE consultants has developed a modification to MAPET where emptied sludge is hauled by small tank cart to a transfer station.
MAPET within the sanitation system
In the short term, there is scope for the MAPET service to be integrated into the wider sanitary system of Dar es Salaam. With on-plot sanitation, MAPET can function independently backed up with intermittent maintenance, finance and supervisory support from DSSD. With off-site disposal, MAPET can either dispose of sludge on a neighbourhood site, or be fully integrated into the city sanitation system when latrine sludge is transferred to sewage treatment ponds using mobile transfer tanks.
The MAPET teams are community orientated, operating from neighbourhood offices, from where public promotion of the service is also organized. Willingness to pay for the service appears to be high because of direct negotiations between customer and emptiers about price and service; an emptying service that accommodates household finances and direct supervision (normally by a woman) over the emptying process. Social surveys have been conducted with residents in an effort to understand household needs and wants.
At the end of the pilot project in 1992 seven teams were active with equipment in Dar es Salaam, and one team in Morogoro. By March 1994, five teams were still operational.
The principal benefits of the MAPET project have been to:
- Provide a sanitary service for those areas which could not be served by vacuum tankers ;
- Improve traditional emptying methods, ensuring a more efficient and hygienic service.
Muller, M. and Rijnsburger, J. MAPET - Manual Pit-Latrine Emptying Technology Project: Development and Pilot Implementation of a Neighbourhood Based Pit Emptying Service with Locally Manufactured Handpump Equipment in Dar es Salaam, Tanzania, Final Report. Waste Consultants, Gouda, 1994
For further details concerning MAPET, contact:
Maria Muller or Jaap Rijnsburger, WASTE Consultants, Crabethstraat 38F, 2801 AN Gouda, THE NETHERLANDS. Tel: +31 1820 22625; Fax: +31 1820 84885;
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Dr Astier Almedom, London School of Hygiene and Tropical Medicine and Christian Odhiambo, CARE, Kenya
In order to improve project design and implementation for rural water and sanitation systems it is crucial to understand how people use the facilities. This project has developed a field manual through a series of field tests with project staff working in the design and execution of hygiene behaviour evaluation studies, in order to help in the process of understanding the issues involved. The methodology which was developed showed that women use rational decision making skills in choosing water sources according to the intended use of the water.
This applied research project has yielded a methodology which helps project staff to understand reasons for the use of different water sources so that health and hygiene education are now more clearly focused in this part of Kenya.
The SHEWAS project was conducted in Siaya district, western Kenya, and implemented through CARE International. Its main aim was to improve the health of the people of the Boro area of Siaya, 85 per cent of whom had no access to clean water. After initially employing the Participatory Rural Appraisal technique, field work led to modifications according to local conditions and PRAV (Participatory Rural Appraisal at the Village level) was introduced which allowed for thorough appraisal in a relaxed manner. SHEWAS project staff were also familiar with PROWESS tools for community participation.
The villagers in this district were asked two questions:
- To what extent are the improved water sources introduced by the SHEWAS project actually used?
- What factors affect women's choice of water source?
These and related questions were tackled in an intensive, qualitative investigation of hygiene behaviour and activities. The main tools employed during the study were a mixture of traditional anthropological techniques and participatory methods and tools. The choice of tools were affected by the following factors:
- The availability of existing participatory materials suitable or adaptable for the purposes of this study;
- The capacity of the study team;
- The total time available for the study.
Initial exploration by the study team (an adaptation of the PRA transect) involved staff members walking around the village, stopping for informal conversations with local people, visiting local water sources and other relevant sites. This 'systematic walkabout' was designed to give a qualitative impression to project staff of local needs. Pocket charts were also employed, with drawings representing known variables (such as an accessible water source) contained within the pockets of a chart made of canvas and transparent polythene. Colour coded voting cards were used to indicate the gender of the voter. The pocket chart exercise was carried out by a self-selected sample of enthusiastic community members who had time to come to attend the meeting.
The drawings were circulated among participants and fully discussed so that a consensus was reached as to what the pictures actually represented. This removed any ambiguity from the process. Following consultation with the participants, a further drawing (of watering the vegetable garden) was added to the chart before voting began.
Cross checking of these methods included direct observation and open ended interviewing techniques of a selected number of mothers/carers of young children who were visited in their homes.
The implications for water use patterns were clear.
- Women chose their water source according to the purpose for which the water was intended. Factors influencing that choice included water quality as perceived and defined by the community; the distance from the home/convenience; and the quantity of water available.
- Women chose clean sources when fetching water for drinking. This water was then normally stored in a special pot with a cover. Water for other uses, such as cooking was frequently kept in the kitchen area often uncovered.
- Water quality was determined by certain attributes such as feel, taste and smell. Water from traditional, unprotected sources was perceived as being soft and good for washing clothes because it lathered quickly and was economical with soap. This source was perceived as being superior for making tea and cooking, when compared to water from protected sources. Salty water from a protected source was perceived to be good for drinking despite its hardness and disagreeable smell when compared to unprotected source water.
- Women use rational decision making skills when deciding which water source to use for particular needs.
- The reasons why a community uses water taken from a traditional water source, even after a protected source has been established is complex. It rests partly with perception of water quality, the quantity required and the distance or inconvenience involved in fetching the water. In the case of Masanga village, a borehole fitted with a handpump did not meet all the community's requirements. It was rational therefore, for village women to use other unprotected sources to supplement their needs.
- The study indicated that the location of a water source was directly affected by the proximity of latrines. In some instances, project staff found that community members had difficulty on ordering the demolition of a latrine in order to protect a water source because construction of the latrine represented considerable personal effort and expense on the householder's behalf.
- Design and cost are significant factors. For example, the cost of protecting a large pond may be higher than providing a protected borehole.
- The decision as to which water source to protect is affected by a complex set of decisions.
- The location of the water source and the reliability of its yield are important factors to consider. In the SHEWAS example, traditional water sources are seasonal and not worth protecting. Those that are not seasonal are frequently on private land (as in the Masanga village), a situation that is problematic for villagers in terms of access, and responsibility for operation and maintenance.
Boot, M.T. and Cairncross, S (Eds.), Actions Speak: The study of hygiene behaviour in water and sanitation projects, International Water and Sanitation Centre and London School of Hygiene and Tropical Medicine, London, 1993
Almedom, A., Mboya, T., Moraa, V., Odhiambo, C., and Ouma, Z., 'Siaya Hygiene Evaluation Study', report to the SHEWAS Project and the Environmental Health Programme, London School of Hygiene and Tropical Medicine, London, 1994
Government of Kenya, National Environment Secretariat, Participatory Rural Appraisal Handbook: Conducting PRAs in Kenya, National Resources Management Support Series No. 1, National Environment Secretariat, Nairobi, 1990
Sirinivasan, L., Tools for Community Participation, PROWESS, UNDP, 199
For further details, contact
Dr Astier Almedom. The Environmental Health Programme, London School of Hygiene and Tropical Medicine, Keppel Street, London. WCIE 7HT Tel: 0171 927 2211; Fax: 0171 636 7843; E-mail: AAlmedom@lshtm.ac.uk
Mr Beat Ruhr, Country Director, CARE International in Kenya, PO Box 43864, Nairobi, KENYA. Tel: + 254 2 724674 / 28; Fax: +254 2 728493
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GK Folkard, JP Sutherland, MA Mtawali and WD Grant, University of Leicester, United Kingdom
In many parts of the world river water which can be highly turbid is used for drinking purposes. This turbidity is conventionally removed by treating the water with expensive chemicals, many of which are imported at great expense. This project has investigated the use of crushed seeds from the tree Moringa oleifera as a natural alternative to these conventional chemicals. Results were obtained from a full scale water treatment plant at Thyolo in Southern Malawi which demonstrate that the seeds reduce the turbidity of the raw water by 80 per cent leaving a clear, very low turbidity water.
This applied research project has shown that turbid waters can be clarified to the same degree achieved by imported chemicals by using a natural substance which can be purchased locally from villagers.
Natural coagulants have been used for centuries in traditional water treatment practices throughout certain areas of the developing world.
Although a native species of northern India, the tree is now grown extensively throughout the tropics and is found in many countries of Africa, Asia and South America. Moringa trees have the capacity to grow rapidly from seeds or cuttings, even in poor, marginal soils; require little horticultural attention and are resilient to the effects of extended drought.
For water treatment purposes, the seed pods are allowed to dry naturally on the tree prior to harvesting. After shelving the seeds are crushed and sieved using traditional techniques employed in the production of maize flour. Approximately 50-150 mg of ground seed will be needed to treat a litre of river water, depending on the quantity of suspended matter. A small amount of clean water is then mixed with the crushed seed to form a paste. Dosing is usually according to a 1-3 per cent solution. The crushed seed powder, when added to water, yields water soluble proteins that possess a net positive charge. The solution therefore acts as a natural cationic polyelectrolyte during treatment (Sutherland, J.P., Folkard, G.K. and Grant, W.D., (1990).
Transferring from the individual household to the continuous flow water treatment works has been one of the primary tasks of the University of Leicester's work.
Large scale water treatment works
The University of Leicester's work involved a pilot water treatment works at Thyolo in Southern Malawi, built within the grounds of the main treatment works. The source river used during the research showed turbidity levels in excess of 400 NTU. Solids removal within the plant was above 90 per cent following a gravel bed flocculation stage and plain horizontal flow sedimentation. A last rapid gravity sand filtration gave a final, treated water turbidity measure generally below 5 NTU. Dosing levels of Moringa oleifera seed varied between 75-250 mg depending on initial raw turbidity.
Following the results from the pilot works, permission for full scale trials at the main water treatment plant was subsequently received from the Malawian authorities. The Thyolo works consist of upflow contact clarifiers followed by rapid gravity filters. Soda ash and alum solutions are introduced to the incoming water flow via gravity feed systems at great expense (annually a charge of £26,000 is made for importing these chemicals from South Africa). Moringa oleifera for the full scale trials were purchased locally from villagers at a fraction of this cost.
The results of two typical trials are given in Figure 1 and Figure 2 below. The works were operated at 60m3/hour with the coagulant solution dosed and monitored using a small centrifugal pump and rotameter respectively. The results of dosing Moringa oleifera seed solution at 75 mg/litre over a seven hour period compares favourably with performance figures for alum dosing at 50mg/litre. Turbidity removal rates are approximately 80 per cent over both trials.
The results from the pilot and full scale trials indicate the viability of Moringa oleifera as a natural coagulant for highly turbid river water. Inlet river turbidities in excess of 270-380 NTU were consistently reduced to below 4 NTU in the finished water.
M.oleifera seed contains 40 per cent by weight of oil, with the remaining presscake containing the active ingredients for natural coagulation. The high market value for the oil make the case for promoting the cultivation of the seed a strong one. The growth of M. oleifera trees by smallholder farmers should be actively promoted as a means of providing vegetables and raw material for oil extraction in addition to a simple, but effective natural coagulant for turbid river water.
Using Moringa oleifera as a replacement coagulant for proprietary coagulants meets the need for water and wastewater technology in developing countries which is simple to use, robust and cheap to both install and maintain.
Folkard, G.K., Sutherland, J.P. and Grant, W.D., 1990. Natural coagulants for appropriate water treatment: a novel approach, Waterlines, April, 8 (4), 30-32
Travis, V.E., Sutherland, J.P., & Folkard, G.K., High Rate Contact Flocculation - Filtration Using Natural Coagulants, First International Conference Environmental Engineering, Vol 2, 47-54, 21-23 Sept 1993, De Montfort University, Leicester, U.K.
Holmes, R.G.H., Folkard, G.K., Travis, V.E., & Sutherland, J.P. Natural Coagulants in Wastewater Treatment, First International Conference Environmental Engineering Vol 2, 47-54, 21-23 Sept 1993, De Montfort University, Leicester, U.K.
Sutherland, J.P., Folkard, G.K., Mtwali, H.A. & Young, R.J. Performance of a natural coagulant at pilot and full scale in Malawi. First Southern Africa Water and Wastewater Conference. Southern Africa after the drought, 87-92, 21-24 Sept 1993, Johannesburg, South Africa.
For further details, contact
Dr G K Folkard, Engineering Department, University of Leicester, Leicester LE1 7RH. Tel: 0116 252 2538
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Dr S Cairncross, London School of Hygiene and Tropical Medicine & Vector Control Research Centre, Pondicherry, India.
A significant public health problem in India and other parts of the world is Bancroftian filariasis which is transmitted by some species of Culex mosquitoes which breed in open pools and sullage drains. This project in Pondicherry, India, surveyed a range of different breeding sites such as drains, soakage pits and flooded land and measured the number of mosquito larvae and pupae. An indicator describing the relative importance of each category of breeding site was calculated. It was found that there were very wide variations, for example, U-shaped drains produced far more mosquitoes than unlined drains.
This applied research project has highlighted how the vector control programme in Pondicherry should target its scarce resources to control mosquito breeding and has demonstrated a methodology which can be widely applied.
Ironically, improvements in water supply provision, designed to reduce incidence of disease, can inadvertently increase morbidity through the creation of sullage pools and open drains which become breeding sites for Culex mosquitoes, some species of which pass on Bancroftian filariasis. Urban filariasis transmitted in this way, is a significant public health problem in India, where about 50 per cent of all cases are found. Culex pipiens mosquitoes lay their eggs in open drains and pools containing wastewater, which implies that disease transmission is closely related to poor sanitary conditions. With rapid urbanisation associated with inadequate infrastructure provision in many developing country cities, the prevalence of urban filariasis is set to increase.
The transmission of Bancroftian filariasis is generally highly inefficient which means that infection depends on a high person biting rate. In turn, this implies that a reduction in the mosquito population, rather than eliminating mosquitoes altogether, is sufficient to control or eradicate the disease (Webber & Southgate, 1981). Because human actions create breeding sites for the mosquitoes, it is reasonable to direct human intervention so as to remove them. However, breeding sites are typically scattered, small in size and numerous so that elimination requires considerable organizational and material resources. Given this context, a method which allows public health workers to assess the importance of each type of breeding habitat, in terms of its contribution to the total mosquito population, is required in order to target resources and ensure cost-effective interventions.
This project describes the methods and results from a project implemented by Filariasis Control Demonstration Project (1981-85) run by the Vector Control Research Centre in the City of Pondicherry. The method could be applied to other cities where the control of breeding mosquito populations is a potential or actual health problem.
The principal breeding sites which were surveyed during the course of the year included flooded land; wells; soakage pits; L-drains; U-drains; unlined drains; and stormwater canals. Weekly surveys of different breeding habitats for mosquito larvae and pupae were carried out with the aid of a sampling dipper. Wells were surveyed three times a year, using a sampling bucket. Three zones, representative of the different environment types were used as control zones.
Dipping varied according to breeding site. On flooded land, one dip sample was collected from each square metre of accessible area around the edge of each pool; two or three dips were taken from soakage pits; two dips were taken from every 10 metres of drain or canal. One or two buckets were taken from each well, depending on diameter.
The mean number of pupae per dip or well bucket obtained during a year's sampling was divided by the area of the sampling vessel to give an equivalent mean number per square metre. This figure was multiplied by the proportion of total available surface area of habitat in which pupae were actually found, to obtain an index of the mean productivity of that type of habitat per unit of area available. This index could then be multiplied by the total area of that type of potential breeding site in any given part of the town, giving a number proportional to the number of adult mosquitoes likely to emerge each day from sites in that neighbourhood.
- Wide variations in the Productivity Index exist between the various types of breeding site. Soakage pits are over 60 times more productive than wells, for example. This is a product of differing pupal densities and differences in the proportion of the area where breeding occurs. This can be explained by the fact that only part of the area of a drain is covered in ponded water, while all the water in soakage pits is normally stationary.
- The Productivity Index determine which habitats require priority intervention. Due to variation in productivity between habitats of different types, those in need of greatest attention are not necessarily those which account for the largest surface area. In the Indira Nagar neighbourhood of Pondicherry, the most notable contrast is between the relative contributions of flooded land and soakage pits. While the former accounts for only 3.2 per cent of the total water surface they produce one third of total mosquito populations, which is higher than any other type of breeding site.
- The results also indicate the importance of U-drains when compared to other types of drain. Although L-drains have three times as much surface area, U-drains produce more than twice as many mosquitoes. Unlined drains, contrary to received wisdom, are of lesser importance. For the engineer, the lining of unlined drains is therefore of less importance than addressing wrongly designed and poorly constructed U-drains.
- The Indices can also be used to assess the total mosquito breeding potential of different parts of Pondicherry. The total for each area is an index which can be assumed to be proportional to the daily production of adult mosquitoes. When divided by the total area of land in hectares, it gives an indication of the likely relative density of mosquitoes in each area. This can be compared with figures for person-biting rates of resting catches, or to determine priority areas fro larval control operations. Since mosquito catches fail to filter out the incidence of migrating insects, these indices may give a more accurate picture of the relative priorities for the elimination of breeding sites.
The main point arising from this work is that breeding sites are not necessarily those which are assumed to be the most obvious, most likely or most extensive. Surveys of this kind can help to target the resources which public health engineers marshal in their attempt to reduce disease transmission vectors. The capacity to make these interventions, however, remains with the engineers - it is crucial that these two professions work closely if urban filariasis is to be significantly controlled.
Menon, P.K.B & Rajagopalan, P.K. Relative importance of different types of breeding habitats in contributing to the population of Culex pipiens fatigans in Pondicherry. Indian Journal of Medical Research, 1980, 71, 725
Service, M. W. Mosquito Ecology: Field Sampling Methods. Applied Science Publishers, London 1980
VCRC Vector Control Research, Annual Report 1986-86. Vector Control Research Centre, Pondicherry, India (1986)
Curtis, C.F. & Feacham, R.G. Sanitation and Culex pipiens mosquitoes: a brief review. Journal of Tropical Medicine and Hygiene, 1981, 84, 17
Webber, R.M. & Southgate, B.A. The maximum density of anopheline mosquitoes that can be permitted in the absence of continuing transmission of fiariasis. Transactions of the Royal Society of Tropical Medicine and Hygiene, 1981, 75, 99
For further details, contact:
Dr. S. Cairncross, Department of Tropical Hygiene, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT. UNITED KINGDOM
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After Independence in 1975 Mozambique promoted a self help latrine construction programme; both technical problems and difficulties with materials supply were encountered. This project was launched to identify and develop a suitable technology for large scale implementation of on-plot sanitation in peri-urban areas. Five new types of improved latrine designs were developed, training workshops held and marketing strategies developed.
This applied research project resulted in the construction of about 135,000 latrines in peri-urban areas between 1979 and 1994. The early success with which the findings were translated into practice have run into some problems since the reorientation of the country's economy in the late 1980's.
Although the national latrine building programme achieved a relatively high level of sanitary coverage (80-90 per cent of families in urban areas and organized rural areas had access to latrines), several problems restricted the success of the programme: many of the latrines fell into disrepair; the lack of technical guidance in latrine design and construction led to design failures; there was insufficient awareness of the problems caused by varying environmental conditions; and shortages of critical building materials hindered the pace of the programme.
With these constraints in mind, the National Directorates of Housing and Preventative Medicine (with financial support from SIDA, UNDP, and IDRC) launched a research project in 1979 with the objective to, 'identify and develop a suitable technology and method for large scale implementation of improved sanitation in peri-urban areas'.
Experiments and results
The focus of the research project was to develop latrines which were appropriate to various circumstances and production methods. Efforts were directed at the following constituent elements: latrine slabs; improved pit latrines; workshops; training and marketing. Brief details of each of these elements are given below:
Latrine slabs needed to meet several criteria - being resistant to rotting and insect attack; having a smooth surface; being easy to clean; inexpensive; and easy to transport. The final design involved circular slabs (for ease of transport) of either 1.5m or 1.2m diameter, conical in shape, and made from non-reinforced concrete. The conical form allowed for ring tensions at the periphery and compression in the centre, which in combination made reinforcement unnecessary (slabs could typically hold the weight of six persons).
Around the squat hole, an area 10cm wide slopes inwards to ensure that faeces are washed into the latrine - the rest of the slab slopes outwards, dry quickly and are easy to clean. Footrests are incorporated into the design to ensure the user sits in the correct position in relation to the hole. To reduce the incidence of fly and odour nuisance, each slab has a tight fitting lid (with handle) that covers the squat hole.
Total average cost per slab in 1985, assuming a 7 person work team, was 226 meticals.
It was recognised that if sanitation conditions were to be significantly affected, improved pit latrine designs would need to be developed. Different design types were developed for different prevailing soil conditions (i.e., loose soil, where it is difficult to dig etc), resulting in five standard types of pit latrines: improved traditional; unlined pit with a slab; lined pit with a slab; elevated pit; and bore hole pit.
Workshops were run continuously throughout the course of the project, being used to test experimental designs and to monitor the inputs required in construction, and the outputs in terms of sales and marketing.
Training of personnel became necessary as new components were developed in the project. The programme aimed to provide training for two workmen and one supervisor from each city in the details of slab construction, latrine building and operation of a workshop. Training sessions lasted 30 days and the project's workmen and supervisors acted as teachers.
Marketing is an essential element if the latrine building programme is to become self-financing. An understanding of willingness to pay, and the operation of credit systems are key steps in achieving success.
Between 1979-1994, the Low Cost Sanitation Programme (LCSP) estimated that 135,000 improved latrines had been produced, which implies that 810,000 people in peri-urban areas have benefited from the programme.
Despite the apparent success of the programme, there are a number of factors affecting the continued development of the project. The reorientation of the economy during the late 1980's has led to currency devaluation's and dramatic increases in the price of building materials, such as cement. The absence of a national policy on improvements in sanitation, and the need for adequate institutional integration also limits the effectiveness of the programme.
With these issues in mind, several key points have been identified which are crucial for the maintenance of the programme:
- Government subsidies to support the LCSP activities should be given a high priority;
- Inter-sectoral co-ordination should be strengthened;
- Gradual decentralisation of the productive sector should be promoted;
- Educational component of the programme needs to be strengthened.
These points have been incorporated into the Master Plan 1995-200 which will serve as a basis for continued implementation of the national policy of low cost sanitation in Mozambique over the next five years.
Brandberg, B., The latrine programme, IDRC Manuscript report, June 1985
Monteiro, P.O., and Macamo, V., Mozambique - low cost sanitation programme, 21st WEDC Conference, Kampala, Uganda
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