There is no shortage of technology for purifying water. But at the marginalized user level, technology often fails to have impact because it is inappropriate for the area. Relief and development agencies must continuously search for new, low-cost, appropriate technologies that can be transferred and adopted in poor villages: cheap, requiring minimal maintenance capacity, easily adoptable, and able to show dramatic results.
One example is the point-one-micron hollow fiber filter, which meets all these criteria. Alongside specific technologies, a broad framework strategy helps: the A3U (or AAAU) strategy.
- Availability of water: natural water points and sources, open and bore wells
- Access to safe water through filtration (biosand filters, hollow fiber filters) to ensure it is potable
- Asset creation through surplus water, where safe water can be used to generate income
- Utilization of water and safe water practices, including Community Led Total Sanitation and zero open defecation
When starting in a new development area, begin by exploring whether water free from contamination is available. Most communities live around a water source such as a river, pond, or lake; these are often contaminated and cause gastrointestinal problems, but as long as there is no poisonous contamination, this water can be filtered. Where water is not easily available, establishing or rehabilitating a bore well, micro-watershed development, and sand dams come into play.
Once water is available, safe access becomes the next concern. Where water is not extremely turbid, the biosand filter works well; for muddy water with high contamination, the point-one-micron hollow fiber filter (similar technology to kidney dialysis) is used. NGOs have seen strong results with these filters in Indonesia, Kenya, Uganda, Cote d'Ivoire, Ghana, Liberia, Bolivia, Ecuador, and Honduras. One detailed study in Ecuador found a 60 to 70 percent reduction in disease burden, with savings of 30 to 40 USD per month in medical expenses per household.
A lot of contamination happens around storage and utilization, which calls for behavior-change training. Community Led Total Sanitation programs are complementary, making for a successful WASH strategy that avoids environmental enteropathy.