When safe drinking water is a prime health worry that drives people to commercially available water filters, innovative bio-sand filters come handy in reaching safe water to a lot more households when cost is a major concern.

Bio-sand filter is the result of a technology developed by the University of Calgary. Though the international version is made of ferrocement, the Cochin Child Foundation, an organisation to improve the quality of life of children, has innovated in making this filter in food quality plastic that can be recycled.

M.V. Joseph, chief executive officer of the foundation, also a member of World Health Organisation and UNICEF expert committee on Integrated Management of Childhood Illnesses, told The Hindu that bio-sand filters work on the same principal as water purification under the Earth.

However, the earthy medium inside the filter can be kept free of harmful microbes with the help of healthy bacteria that is allowed to grow in the wet sand medium.

The quality of water has been tested several times and recorded for its safety, said Mr. Joseph. The Cochin Child Foundation that has associated with various organisations like National Rural Health Mission, IMA and others to implement different projects in the city, has the support of the Lions District 324 E-4 in this project. It was after many tests that 20 schools and 300 anganwadis in the district have been provided with these filters.