Appropriate water supply and sanitation solutions in developing countries with particular reference to Papua New Guinea

Introduction

Communities need safe drinking water and adequate sanitation if they are to be healthy and develop socially as well as economically. In tropical regions people require about five litres of bacteriologically safe water for drinking, brushing teeth, preparing food, and washing utensils. If this water is not bacteriologically pure it must be treated. Water that is bacteriologically unsafe but relatively clean can be used for activities such as laundering, bathing, and cleaning latrines. The availability of safe water must be complemented by adequate sanitation if improvements in health and welfare are to be realised.

In regions with unsafe water and inadequate sanitation the infant mortality rate usually exceeds ten percent and life expectancy is usually less than 50 years. Numerous serious problems arise in the developing world from water borne diseases caused by inadequate supplies of readily available safe water and poor sanitation. Over 40,000 children die daily from water borne diseases. Women and children spend many hours each day collecting water from remote sites and this constant collection over time causes severe skeletal problems. In addition the time taken to fetch water means that many children, especially girls, cannot attend school. In the developing world about three quarters of the urban population and just under half the rural population have adequate supplies of water and at times these supplies can be quite unsafe. Only about half of the urban population and a seventh of the rural population in developing countries have adequate sanitation.

Inexpensive and appropriate technologies are necessary for solving water and sanitation problems in the developing world. First world solutions such as reticulated supplies of expensively treated drinking water and sophisticated sewerage systems again with expensive treatment systems are simply not affordable. Appropriate technology in itself of course does not generally work without hygiene education/promotion, community participation, capacity building, and an emphasis or sustainability (e.g., ongoing operation and maintenance). However, having available the appropriate technology is clearly the vital first step.

Water for Survival is a New Zealand based non-governmental development organisation supporting water supply, sanitation, and health promotion projects in developing countries. One of the projects currently supported is in community and primary schools in the Dualo District of the Eastern Highlands Province of Papua New Guinea. The Dualo District lies 1,800 metres above sea level in a fertile, river-silted valley where the temperature ranges from 14 to 30 degrees centigrade. Infant mortality in Papua New Guinea is 79 per 1,000 live births and it is one of the few countries in the world where women, on average, have shorter life spans than men (UNICEF, 1995). The country also boasts one of the highest maternal mortality rates in the world.

The process involved in getting toilets and health education into Eastern Highland schools started in 1999. Save the Children Australia had already funded the installation of water tanks but because sanitation, or more correctly the lack of it, is often a bigger problem than the lack of clean water, a local NGO (Non Governmental Organisation), AT (Appropriate Technology) projects approached Water for Survival in New Zealand for help. Water for Survival then went through a project selection process which included an appraisal of poverty and injustice, human rights, gender, self reliance, participation, capacity, sustainability, planning and design, and participatory monitoring and evaluation before agreeing to fund the project. Water for Survival then went about raising the funds from donors.

This paper first illustrates common examples of appropriate water and sanitation technologies for developing countries, particularly Papua New Guinea. It then describes methods used by Water for Survival for promoting hygiene in developing countries, again with an emphasis on Papua New Guinea.

Appropriate Water Supply Systems

Rainwater tanks

Rainwater is used in many parts of the world, including rural New Zealand, as a source of clean and safe water. The water is collected from roofs in gutters which can be made from a variety of different materials, e.g., metal, wood and PVC. A screen should be used for the main flow and during the first few minutes of a rainstorm the flow should be led to a drain in order to ensure that accumulated dirt and debris from the roof and gutters do not enter the storage tanks. The water needs to be stored in a clean and covered tank and water removed by using a tap if possible, otherwise by using a clean dipper kept inside the tanks.

Figure 1. Rainwater Harvesting System

Spring Protection

In certain situations a gravity or artesian spring can be "protected" to ensure a safe supply of water. Gravity springs appear where groundwater emerges from the ground's surface due to an underlying, impervious layer preventing it migrating downwards. These springs are generally associated with sloping ground and as the water table height rises their flow increases. Artesian springs appear where groundwater emerges from the ground's surface following being confined between two layers of rock of an impervious nature. These springs are generally fairly constant in flow.

Figure 2. Various Stages in Sprint Protection

Prior to commencing a spring protection project the local community needs to become fully involved and information collected on water quality and quantity, contamination sources, and ownership issues. Spring protection is not suitable in areas that flood regularly, are wet and boggy, or erode easily.

Groundwater Development

Groundwater generally occupies pores and fractures in soils and rocks, moving very slowly to discharge points, e.g., springs or along the margins of swamps. In general the water table follows land contours. There are a variety of good sites for wells including the following: fault zones where drainage patterns cross, next to granite outcrops where surface run-off collects around the base, above springs where the ground is especially permeable, and at the base of breaks in the slope of the ground.

Hand-dug wells can be a very appropriate way to supply water. However, they need to be easy to reach, well away from latrines, and dug with a full knowledge of both wet and dry season water levels.

Figure 3. A Hand Dug Well

When concrete rings are used on well construction they are cast from steel moulds. They are often cast onsite or alternatively they can be brought to the site. Sinking concrete rings is one of the best methods of constructing hand-dug wells as it is safe and relatively inexpensive, the layers of concrete rings are piled one on top of the other and sink as soil is removed from the inside of the bottom ring and the construction abilities of the local workers improve with every new well. A convenient place to dig a well can be an existing water hole. Mud and organic matter are cleared and a hole dug as deep as safely possible to accommodate the ring. The first ring is lowered on ropes to a level position on the bottom of the hole and then digging continues from the inside of the ring with water removed with a bucket or pump. As the bottom ring sinks additional rings are lowered and the deeper the well the more water and often the greater the infiltration. Safety provisions while hand digging a well include keeping motorised pumps and their fumes at distance from the hole, keeping buckets tied firmly so they cannot fall on the well diggers and ensuring the people down the well wear protective clothing including helmets. It is important to ensure that a platform is dug around the well to allow water to drain away and not seep into the well and contaminate it or become a breeding ground or transmission site for disease organisms. The platform should be reinforced, overly a hardcore foundation on top of compacted clay and should include raised edges to contain the water and a drainage channel to carry it away to a soak pit or to where it can be used for irrigation.

Boreholes (tube wells) differ from hand dug wells in that they are drilled rather than dug. They can be drilled with low technology hand held drilling equipment assuming deeply weathered bedrocks or unconsolidated sediments. When the ground is solid, the hole is drilled followed by installation of the casing which is usually PVC or steel. If a gravel pack is to be added to surround the casing then the casing must be centred in the drilled hole. Grout seals the top of the casing and a screen is utilised below the water line which lets water in but keeps particles out. If the borehole shows a tendency to collapse then drilling is best done inside a steel casing which is then driven down if it does not fall naturally. A smaller diameter plastic casing can complete the well if necessary with the larger steel casing slowly removed and a gravel pack slowly added.

The screen should have an aperture size related to the size of the surrounding particles and can be larger if a gravel pack is utilised which is always necessary in silts and fine sands. There are a variety of different screen types but all should have a minimum open area of eight percent. Screens can be made on location using the same pipe which is being used for the casing.

Boreholes have an advantage over hand-dug wells in that they can be constructed more quickly, they cost less and they are safer. However, hand dug wells can be used in a greater variety of ground types, if required can be made deeper (e.g., if the water table sinks) and can function with buckets if the pump fails.

Pit Latrines

Pit latrines are an appropriate technology that provides an effective method for developing countries to use for dealing with sewage. They can be as safe healthwise as the much more expensive and water intensive sewerage systems of developed countries. They use little if any imported materials and the local people can both construct and maintain them themselves. Latrines need to be cleaned regularly in order to reduce the spread of disease and it is especially important that the excreta of young children are picked up and put in the latrine as they are more likely to harbour disease. It is vital that everyone washes carefully after using the latrine. Pit latrines become unhealthy or unsafe if the sides are unsupported; the floor is of untreated timber (these usually eventually collapse); water does not easily drain away from the hole; the hole is too big allowing children to possibly fall in; the pit is too shallow or full or the pit is open or wet allowing disease spreading insects to breed. Healthy pit latrines have sides lined with permanent materials; reinforced concrete, or ferrocement squatting slabs covering the hole (with seats if people prefer to sit) which allow water to drain away from it; a hole large enough to eliminate fouling but small enough so that children cannot fall in; pits that are a minimum of three metres deep and 1.0 to 1.2 metres in diameter and thus will have an adequate lifespan and a water seal below the slab if people clean themselves with water (the water seal eliminates odours and stops disease carrying insects from breeding).

Figure 5. Simple Pit Latrine	Figure 6. Ventilated Pit Latrine	Figure 7. Waterseal Latrine

Materials technology and latrine housing

In the Eastern Highlands of Papua New Guinea, a government subsidy at a rate of 40 kina (NZ$32) per student per year is paid to each school on a quarterly basis. However, currently there is a provincial funding crisis and only one quarter of the previous year's allocation has been paid out. Students are also charged school fees, but in an area where the per capita income for the year is estimated to be K400 or NZ$330, few pay. Therefore new buildings or repairs to buildings have to be simple and low cost utilising local materials and community labour. The latter includes students and teachers who are involved in the construction of the latrines and supporting structure.

The ATloo latrine structure uses most of the same materials as the traditional round houses. The framing for the latrines is milled timber while the roundhouse is of sticks and logs gathered from the rainforest further up in the mountains. The walls are made from woven bamboo which is sometimes varnished for extra longevity.

Figure 8. An ATloo and a roundhouse

Pitpit or kunai grass, sometimes flattened by cars on the highlands highway, is thatched over the framing to form the roof. The very top of the roof may be fashioned into anything from a topknot to a couple of plaits. Because the latrine roof stands higher than the average roundhouse, the roof overhang has had to be altered to prevent the base rotting. The latrine roofing does not last as long as that on a roundhouse, because it is not water proofed with smoke from a constant fire, and because it needs to be replaced every couple of years, it is not permanently fixed to the structure and can be lifted off by four people. In addition, the whole ATloo structure including the concrete bowl and slab has been designed so that it can be dragged over another hole when the pit is filled.

Water cannot be collected from grass roofs, in the same way it can from corrugated iron roofs, which is one draw back.

Information and Communication Technology

To gain the maximum benefit from the provision of improved water supplies and sanitation facilities there has to be provision for hygiene education. This is not easy when the community does not see the latter as a high priority, especially if the links between water related diseases and health are not understood. Sickness in the Eastern Highlands is often attributed to spells or black magic and a vast majority of the villagers use local healers.

Water-related diseases like diarrhoea, typhoid, and dysentery are prevalent among children. Although it is very difficult to find any health related baseline data in the Eastern Highlands, it is assumed that 11 percent of people who die have typhoid. However a blood test is needed for a diagnosis and even then the results may be suspect due to inconsistent testing.

In the Eastern Highlands' primary and community schools the water tanks provide half a litre of water per student per day. This often means water is considered too precious to use for washing hands after going to the toilet. Sanitation education in these schools as in many third world countries takes on great importance, but in the Eastern Highlands is problematic due to the shortage of water.

Where there is no electricity and therefore no computers to communicate important messages about sanitation education it is approached in as many different ways as there are different countries. Some of the graphical communication methods include "pile sorting cards". These are picture cards where sets of 30 coloured illustrations show good and bad hygiene practices. Participants sort the drawings into three piles; those that show activities that are good, those that are bad, and those that are neither good nor bad for health. The cards can be used to facilitate a discussion for participants to share what they know with the rest of the group. This exercise is also useful as a baseline survey tool to assess people's understanding of disease transmission routes and hygiene practices and being pictorial do not require a high degree of literacy.

Figure 9. Examples of Pile Sorting Cards

Another approach to health education is presented by Child-to-Child Readers and Activities. These are copyright-free and produced in over 20 languages including Arabic, French, Hindi, Portuguese, and Spanish. Child-to-Child readers and activity sheets contain essential health information combined with exciting activities designed to reinforce and spread health knowledge and good practice and stress the power and effect of children as agents to promote better health.

Conclusion

Appropriate technology currently being used in developing countries provides many excellent examples where students can study the structures and mechanisms, materials, and information and communication technology areas of the New Zealand technology curriculum. A study of appropriate technologies is also a detailed study of the society strand of the curriculum because the technology cannot be appropriate without cognisance of people's beliefs, values, and ethics.

References

Child to Child Readers Internet site:http://www.child-to-child.org/about/whatwedo.html

UNICEF (2000) Internet site: http://www.unicef.org/statis/Country_1Page135.html

Uyassi, M. (1990). The Eastern Highlands, Papua New Guinea. Papua New Guinea: Eastern Highlands Provincial Government.

Note:
More information please contact Water for Survival, P O Box 6208 Wellesley Street, Auckland or email: johnwfs@clear.net.nz

Useful websites, which incorporate technology, social studies, and science curriculum objectives include:

http://www.megabright.co.nz/project241

http://education.otago.ac.nz/NZLNet/WaraBlongLife/resources.html

Acknowledgment

Our thanks to Monika and Paul for making this material available for use by technology teachers.

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