ROBERTS, M., 2004. Field test of a silver-impregnated ceramic water filter. IN: Godfrey, S. (ed). People-centred approaches to water and environmental sanitation: Proceedings of the 30th WEDC International Conference, Vientiane, Laos, 25-29 October 2004, pp. 499-504.
The silver-impregnated Ceramic Water Purifier (CWP) is a low-cost household water filter that removes micro-biological
contamination at the point of use. One thousand CWPs were distributed in twelve Cambodian villages to test their effectiveness
under conditions of rural household use. Water quality tests (n=686) were conducted to measure filter performance.
A control group comparison survey (n=201) and a baseline and follow-up survey (n=1,000) measured impacts on
household health and expenses. Ninety-nine percent of CWPs produced water meeting WHO ‘low risk’ guidelines or better
(10 or fewer E. coli per 100 ml). Households that used CWPs experienced significantly lower incidence of diarrhoea than
households without CWPs. Households that had previously boiled their drinking water experienced savings in time and
expenses after using the CWP. The CWP’s low production cost (US$5.50) opens the possibility of reaching large numbers
of the rural poor through sustainable market channels.