Abstract
In the last 20 years, the widespread adoption of shallow tubewells in Nepal Terai region enabled substantial improvement in access to water, but recent national water quality testing showed that 3% of these sources contain arsenic above the Nepali interim guideline of 50 μ g/L, and up to 60% contain unsafe microbial contamination. To combat this crisis, MIT, ENPHO and CAWST together researched, developed and implemented a household water treatment technology by applying an iterative, learning development framework. A pilot study comparing 3 technologies against technical, social, and economic criteria showed that the KanchanTM Arsenic Filter (KAF) is the most promising technology for Nepal. A two-year technical and social evaluation of over 1000 KAFs deployed in rural villages of Nepal determined that the KAF typically removes 85–90% arsenic, 90–95% iron, 80–95% turbidity, and 85–99% total coliforms. Then 83% of the households continued to use the filter after 1 year, mainly motivated by the clean appearance, improved taste, and reduced odour of the filtered water, as compared to the original water source. Although over 5,000 filters have been implemented in Nepal by January 2007, further research rooted in sustainable development is necessary to understand the technology diffusion and scale-up process, in order to expand access to safe water in the country and beyond.
Acknowledgments
The authors would like to acknowledge the following organizations for their contribution to this project (alphabetical order): Asia Arsenic Network, Filters for Families, Filters Nepal, Global Water Trust, Hong Kong Polytechnic University School of Design, Institute of Technology of Cambodia, Japan Red Cross Society, Kathmandu Rotary, Kathmandu University, Lemelson Foundation, MIT IDEAS Competition, Nepal Dept. of Education, Nepal Dept. of Irrigation, Nepal Dept. of Water Supply and Sewerage, Nepal National Arsenic Steering Committee, Nepal Red Cross Society, Nepal Water for Health, Rural Water Supply & Sanitation Fund Development Board, Rural Water Supply Sanitation and Support Program, Simavi Foundation, Sophie Walewijk, St. Andrews Prize for the Environment, Tribhuvan University, UN-Habitat Water for Asian Cities Programme, United Nations Children's Fund, US Environmental Protection Agency, US Peace Corps, Wall Street Journal—Technology Innovation Awards, Water Aid Nepal, World Bank Development Marketplace.