Clear water bottles line the rusty iron sheet roofs of several houses in the sprawling Kibera slums in Nairobi. A cursory glance may not reveal much, but this is a simple water treatment process in progress. The Solar Water Disinfection (Sodis) technology uses the sun’s ultraviolet rays and the increased temperature due to exposure to direct sunlight to kill micro-organisms in the water.
“We only need to leave the water out in the sun for a whole day and it is safe for drinking,” says Ms Dushman Abdul, a Kibera resident. She no longer needs to boil drinking water for her family and as a result, she now saves the money that she would have spent on buying fuel. Laying out her 10 bottles of water on the roof has become a daily routine for the housewife. This is enough drinking water for herself, her husband and their two-year-old daughter.
Besides incurring an initial cost of Sh15 per water bottle — which can be used for six months — the technology is absolutely free, relying entirely on the sun’s energy.
Besides families, the technology is finding its way into schools and other public facilities. At the Makina Self-Help School in Kibera, for instance, an iron sheet topped rack has been erected in the compound to hold the water bottles as the sun’s rays purify their contents.
According to Mr Benson Muthoka, the deputy head teacher at the school, the adoption of the technology four years ago was motivated by frequent incidents of diarrhoeal diseases, leading to high pupil absenteeism and poor performance. Mr Muthoka says that over the last four years, such cases have drastically gone down in the school that has a population of 400 pupils. The pupils, too, are encouraged to take the message of the new technology home.
This is one of the strategies being used to treat water in Kibera slums, whose residents are often ravaged by water-borne diseases such as cholera, due to limited access to safe drinking water.
Many of the slum dwellers do not have access to piped water and thus they rely on water from vendors, who claim to fetch it from taps. But this is usually not the case and even when it is from the taps, its safety is not assured since the hygiene of the containers used is questionable. There is a high risk of contamination even in the pipes. In parts of Kibera, open sewage flows and when the plastic water pipes break at such points, it provides an opportunity for contamination.
“Some of the water storage tanks are usually open, which is a contamination risk as well,” Ms Neema Abdullahi, who leads the team promoting the technology in Kibera, told the Nation.
The Sodis technology is one of those being touted as a simple alternative in treating water at the point of use.
Though already in wide use in other parts of the world, the Sodis method of water treatment has only been in the country over the last few years and is promoted by the Kenya Water and Health Organisation (Kwaho).
Estimates from the Swiss Federal Institute for Aquatic Science and Research indicate that there are about 4.5 million people using the technology in Latin America, Asia and Africa.
In Kenya, besides Kibera slums, Sodis has been introduced in other parts of the country that are facing challenges in accessing clean drinking water such as Mukuru kwa Njenga in Nairobi, Nyalenda in Kisumu, Wajir in Northern Kenya and the flood prone Budalang’i area in Western Kenya. Plans are underway by Kwaho, in conjunction with the Ministry of Public Health and Sanitation and the United Nations’ Children’s Fund (Unicef), to roll out such simple water treatment and storage methods, including Sodis, use of chlorine tablets, filtering, among others.
According to Ms Lilian Shimanyula, the advocacy and communication officer at Kwaho, all the available options would be promoted as a package, from which one can be chosen. “We are developing strategies that are workable for scale up to the entire nation,” she adds.
Though the strength of Sodis lies in its simplicity, it has proved to be a drawback as well, since selling the idea to policy makers has been met with skepticism. “They think that it is too simple to work,” Ms Shimanyula says.
Tests have found out that there is a significant drop in the amount of disease-causing micro-organisms in the treated water.
Besides, use of the solar treatment method does not interfere with the quality of the water such as its taste.
With the disturbing revelations on access to clean drinking water in Kenya in last year’s national census survey, there is need for innovative strategies such as Sodis to address this problem.
However, its proponents argue that this is not entirely a poor man’s technology since the problem of reliable access to safe drinking water also affects many parts of the city. “It would save the cost of buying mineral water even for those who can afford it,” says Ms Abdullahi. She adds that past studies have indicated that even water in affluent parts of the city is contaminated.
Source: Cosmas Butunyi, The Nation / (allAfrica.com, 9 November 2010