Community Success Stories

Bio-sand filters as an efficient means to obtain safe drinking water


The availability of clean water is an issue in the Paderu region of Visakhapatnam district, Andhra Pradesh. During the rainy season, water gushes into streams at high pressure, contaminating the water with dirt and other debris. To address the issue, bio-sand filters are installed in Paderu households. These are zero-energy, no-maintenance water filters for point-of-use applications that are ideal for residential usage. Each filter is constructed independently with cement, sand, and gravel (concrete) and filled with various sizes of gravel, and then transported to the houses. Once the bio-sand filters are installed, 21 days are the waiting period to allow the formation of the bio-layer on the filter bed. After completion of the waiting period, the filter can be used.

One litre of water per minute is the flow rate of the filter. The Bio-sand filters are efficient enough to reduce the turbidity of water and eliminate sediments, bacteria, viruses, compounds, cysts, worms, and other impurities. Thus, the availability of good quality filtered water has improved the health and well-being at the family as well as community level.

“Bio-sand filters have been installed two years ago, before that we used to struggle a lot to obtain safe drinking water. During the rainy season, the water is extremely contaminated that it cannot be consumed without boiling. We used to have health problems like malaria, colds, coughs, vomiting, stomach ache, and so on before the filter was put, but now our health has improved,” said Ms. Lavanya, the beneficiary