The BioSand Water Filter is an adaptation of slow-sand filtration that is designed for use by families at the household level. This award-winning water filtration technology was developed by Dr. David Manz, a former University of Calgary professor.
The filters are a proven, effective, and inexpensive technology. From start to finish the filters can be constructed in roughly 10 days, at an average cost of $100, which covers the raw materials, construction, transportation, supervision, training for the family in filter maintenance and personal hygiene, as well as monitoring and evaluation.
The Filtration Process
The filter is very durable, constructed from concrete, sand, gravel, and PVC piping. These materials can be found in almost every country and enable community members to help construct the filters on location.
As the filter is used, the biological layer matures and thickens, causing the flow of water through the filter to slow. Recipients of filters are trained to watch for decreased flow and can renew the filter simply by skimming off any debris from the top of the sand, and by gently stirring the sand to break-up the biological layer. The quality of source water will determine how often this process is necessary.