The St Andrews Prize for the Environment

University of St Andrews


2006 Finalist

Kanchan Arsenic Filter

Kanchan Arsenic Filter

Development and Dissemination of Kanchan™ Arsenic Filter in Nepal

In the rural Terai region of Nepal, many tubewells are microbially and/or arsenic contaminated, and consequently, millions of people lack access to “safe” drinking water.  In terms of remediation, little has been done in Nepal prior to the authors’ work, largely because of the lack of appropriate technologies and the previously ineffective implementation schemes that disregarded long-term sustainability and community demand, ownership and involvement.  As a result, many people had no choice but to continue drinking contaminated water and to suffer from preventable water-borne diseases such as diarrhoea, stunting, skin lesions and cancer. 

To solve this problem, a team comprising researchers from Massachusetts Institute of Technology (MIT), together with two local partners, Environment & Public Health Organization (ENPHO), and Rural Water Supply and Sanitation Support Programme (RWSSSP), have developed an award-winning household water filter, the KanchanTM Arsenic Filter (KAF).  This inexpensive (less than US $20 per unit) and innovative filter is designed on an intermittent, household-scale slow sand filter base, influenced by the pioneering work on slow sand filters first begun in Paisley, Scotland in 1804. That work used natural processes and iron hydroxide adsorption principles for simultaneous pathogen and arsenic removal.  The KAF is constructed using locally available labour and materials and is optimized based on the local socio-economic conditions. 

Countrywide dissemination of the KAF started in 2003, with MIT-ENPHO acting as the overall project co-ordinators.  Major accomplishments include:

 The KAF project is innovative in several aspects.  First, the team placed technological design within the cultural and socio-economic constraints of developing countries, resulting in a technology that is simple, user-friendly, affordable and technically sound.  The KAF has the virtue of simultaneously treating microbial and arsenic contaminated water.  Second, the team disseminated the KAF based on a long-term self-reliance model.  The implementation scheme makes use of social marketing strategies and entrepreneurs who profit from their enterprises, as well as a demand-responsive approach that promotes community decision-making, participation, contribution, and ownership. 

The MIT-ENPHO team has won many awards for the KanchanTM Arsenic Filter including;

The KAF is a sustainable solution to drinking water problems.  This project has built capacity of local people towards long-term, user-participatory safe water provision, as well as contributing to the local economy and public health.   As of May 2006, over 3000 filters have been installed, serving 25,000 to 35,000 people.  Better health contributes to higher quality of life and greater worker productivity, leading to overall human development.  To scale-up the benefits to reach an estimated 148 million people in Asia, affected by arsenic in drinking water at concentrations exceeding the World Health Organization guidelines, the team is currently seeking funding to expand this highly replicable model to the neighbouring countries of Cambodia, Vietnam and Bangladesh. 

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