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Karunawathi Menike, head of a small community based organization (CBO) in the dry zone of Sri Lanka, found it almost impossible to make the women of her organization realize the need for safe water to minimize water-borne diseases, mainly diarrhea among children.
"I have been trying to get them to boil water, but firewood is a problem and in the dry zone water is scarce and people drink contaminated water from bore holes and pools when the wells run dry," she said at a training program organized by the Water and Sanitation Decade Service.
To Menike, then, the pilot project by the Decade Service on the solar disinfection of water seemed like the answer she was looking for. She happily enlisted her organization with the project to help popularize this method of water disinfection among mainly rural communities.
Shedding Some Light
The Swiss Association for International Cooperation (Helvetas), one of the member organizations in the Decade Service consortium, has coined the term "SODIS" to refer to the solar disinfection of water. It introduced it to Sri Lanka in 2001 after working in the island nation for 20 years, mainly in water and sanitation provision to communities island-wide. As part of the Decades Service consortium, Helvetas has sponsored the pilot project to test the efficacy and acceptability of SODIS among local communities.
SODIS is a water treatment method that improves the microbiological quality of drinking water which can be adopted by even the poorest of households. All that is needed are a few large empty plastic bottles and about six hours of strong sunlight in temperatures of about 30 degrees Celsius — something that is plentiful during the day in the tropical country!
The empty one-and-a-half liter plastic bottles are filled with water, closed lid-tight, and placed on flat iron or zinc metal sheets in direct sunlight between 9 a.m. and 3 p.m. when the sun is at its brightest. It is best if the water is clear from sediment and not mixed with bits of sand, grit, or decayed leaves that would reduce the penetration of solar radiation into the bottles and protect microorganisms from being irradiated. Six hours of direct radiation (particularly the ultraviolet rays) inactivates the pathogens and destroys most of the bacteria in the water.
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"This is one technique which can be adopted to break the vicious cycle of poverty and ill-health."
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Recent impact studies conducted in Sri Lanka and other countries testing the efficacy of this technology have shown that though SODIS does not kill all the bacteria in the water, it does help to reduce significantly the incidence of diarrhea caused by drinking unsafe water. This is especially of relevance in Sri Lanka, where diarrhea is the number one killer of children under 5 years of age.
"SODIS is a technology that has been perfected in Switzerland many years ago. But it is only recently — in the last ten years — that it has been rejuvenated," said Neil Herath, Program Officer of Helvetas – Sri Lanka.
Herath went on to explain that that this technology has to be viewed against the fact that 20 percent of all diseases in Sri Lanka are water borne, which militates against mainly the poorest families. Fifty-seven percent of Sri Lankans do not have access to safe water while the cost of purifying water by boiling is expensive. In some rural areas the communities cannot afford the cost of fuel, not even firewood, needed for boiling water. Herath added that with the strong sunlight available so plentifully and so freely in Sri Lanka, SODIS should be most suited to that country.
"This is one technique which can be adopted to break the vicious cycle of poverty and ill-health in which water and sanitation are important factors," said Henry de Mel, Chairman of the Decade Service consortium.
Tackling the Dark Side
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About 2 million users in more than 20 countries, including Kenya, use SODIS for their daily treatment of drinking water. (copyright © SANDEC)
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This new and exciting technology is gaining ground in several parts of the world. Seven Latin American countries — namely Bolivia, Ecuador, El Salvador, Guatemala, Honduras, Nicaragua, and Peru — in addition to Asian countries such as Pakistan and India have already started using the technology. In Sri Lanka it is being recognized as a useful initiative that promotes the careful and efficient use of natural resources and is ideally suited to the country's rural areas because of its cost effectiveness.
SODIS being essentially a household technique, however, there are conceptual limitations in the wider use of the technology in that it cannot be adopted to prepare large volumes of water. The Ministry of Health in Sri Lanka also points to the fact that the technology depends mainly on solar radiation, which in turn depends on uncontrollable conditions such as the climate, decreasing the reliability of the technique. The water used must also necessarily be clear, which is not always possible in certain situations and especially in times of drought. As mentioned earlier, SODIS also does not kill all the bacteria in the water.
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A city-based company offered "as many bottles as they needed" free of charge.
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Nevertheless, some continue to argue that the advantages will weigh heavily against these drawbacks when the benefits provided by the technique in terms of saving time, expenses, and effort are looked at. Since the sun's rays do not change the chemical quality of the water or its color or taste, no further treatment needs to take place after the SODIS technique has been followed, making the water immediately available for consumption.
On the ground, the pilot project came up against a different set of problems. Six months after the initiation of the project, the six core-group non-governmental organizations (NGOs) working on the project reported to the Women's Savings Effort, the CBO headed by Menike, that it was not possible to find clear plastic bottles in the villages. A city-based company selling soft drinks in plastic bottles eventually came to provide the solution, however, by offering "as many bottles as they needed" free of charge.
On an average, six one-and-half-liter bottles of water are enough for a family's daily use. Some of the people laid the bottles flat on the ground in the sunlight, but running animals and playing children knocked them out of place. When some of the villagers resort to the corrugated rooftop sheets of their shanties to house the bottles, crows toppled them down. These small problems, however, did not discourage community members from discussing among each other and with resource persons which solutions worked best for them.
Initially the local communities had some concerns over the change of taste and color of the water despite assurances by the project coordinators that they wouldn't. Soon enough the villagers were able to find out for themselves as the project took off the ground.
A Bright Future
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Posters are distributed in the indigenous language of the country promoting the technology. (copyright © SANDEC)
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It was interesting to observe during a meeting toward the end of the pilot project phase that discussing the problem itself brought about solutions. These would come out sometimes from other participants but sometimes from those who had placed the complaints! It was only in finding plastic bottles that the Decade Service had to step in and lend a hand.
Serious discussions are ongoing between representatives of Helvetas, the Decade Service consortium, and the governmental National Water Supply and Drainage Board over the use of the technique, user reactions to it, and the possibilities for future expansion. The Decade Service consortium is also looking into ways to spread the word further and has set up a special unit to educate communities, especially school children, on the efficacy of this method. Leaflets, posters, pamphlets, and other propaganda materials in the indigenous languages of the country (Sinhala and Tamil) have been printed and distributed through a network of NGOs, government agencies, and schools. Workshops targeting mainly rural-based organizations and communities have also been held to persuade them to adopt SODIS and to benefit from the technology.
Special efforts are being made to target women, who are almost wholly responsible for water management at the household level in the country.
Firewood is becoming a scarce commodity in Sri Lanka after extensive logging and the clearing of jungle lands for agriculture have stretched the country's wood supply to the limits. Other fuels such as gas are expensive and their costs are constantly rising, making them inaccessible to many of the country's poor. Extensive water sanitation awareness-raising campaigns conducted by the government health authorities, NGO health programs, and even classroom teachers make people more conscious of the kind of water they are drinking. All these are happy signs that SODIS is here to stay.
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