The APEGGA Project Achievement Award

Canadian Water Filtration Process
David Harold Manz, P.Eng., PhD

David Harold Manz, P.Eng., PhD, has engineered and produced a unique filter to remove all pathogens, turgidity, iron and manganese from household water and to render it suitable for human consumption. The filter design is based on a new form of slow sand filtration called Intermittently Operated Slow Sand Filtration (IOSSF). It replaces the continuous process used since the late 19th century.

The Canadian Water Filter addresses the need to provide a simple, inexpensive device to filter water in remote and underdeveloped regions of the world. It may be constructed using a variety of local materials to suit the local environment. The filter is primarily for household use, but may be scaled-up for community water treatment purposes by using intermittently available power supplies such as solar or wind power. The filter has been tested and found effective for use in temperatures ranging from 5 degrees C to 45 degrees C, and is being used successfully in Canada, Nicaragua, Honduras, Chile and Cambodia. Versions of the filter have been constructed in plastic, fibreglass and concrete.

The Honduran and Nicaraguan projects were funded by the Pan American Health Organization through The University of Calgary and under the direction of Dr. Manz. The Chilean project was funded by the federal government's International Development Research Centre under direct contract with Dr. Manz. As well, the Samaritan's Purse of Calgary has commissioned the construction of a steel mould to facilitate building concrete filters in developing countries. Other evaluation projects are currently underway in Mexico, in Canadian First Nations communities, and by the federal Prairie Farm Rehabilitation Administration. Both automatic and manual versions of the filter are being used in urban, rural, and vacation households in Canada.

The patent rights to the filter are owned by The University of Calgary through its technology transfer entity, University Technology International Inc. Humanitarian rights were retained by Dr. Manz. As well, his firm, Davnor Water Treatment Technologies Ltd., of Calgary, continues to improve the design technology using profits from commercial sales.

Dr. Manz obtained his PhD from the University of Alberta in 1985 and is currently associate professor of engineering (environmental and hydraulics) at The University of Calgary. He has authored numerous publications and has many academic credits to his name.