Access to clean and safe drinking water is a huge challenge for much of the world’s population. Large-scale water treatment plants may not be practical in all environments, and small-scale solutions, while cheaper, are often still too expensive for rural families in underdeveloped countries.

Using the power of the sun to treat water, however, is both practical and affordable. The solar disinfection (SODIS) process uses readily available bottles and exposure to the sun to kill many of the pathogens that cause diarrhea and other water borne illnesses. Placing a bottle of water in full sun for six hours, preferably on a corrugated zinc roof, is all that is needed to reduce the incidence of diarrhea from 30 to 80 percent.

IRD is promoting SODIS programs in three different countries: Laos, Mozambique, and Sri Lanka. In each country, IRD works with local institutions such as schools and health clinics to spread the word about SODIS, often using the large zinc roofs as racks for water treatment. In some cases, IRD has also installed rooftop rainfall collection systems to ensure year-round water availability. Trained volunteers visit families to help them understand and consistently use the technique.

In addition, IRD develops locally appropriate promotional materials to increase the general awareness of the importance of clean water and SODIS at local health facilities and among other organizations. In this way, the programs can continue and be sustainable after IRD’s involvement has ended.

Each of these very low-cost projects benefit thousands of individuals, keeping them and their families healthy.

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