A simple, cost-effective, biological water purification system using river sand, pebbles and activated carbon packed in a PVC pipe has been developed. Some of the salient features of this system include easy to fabricate with locally available materials, requires no electricity, low maintenance cost, chemical free, user-friendly, easy to handle and clean. This system effectively reduces (98.9%) incidence of waterborne diseases and gives people in rural areas access to clean drinking water. MCRC has been distributing this system to many schools in and around Kancheepuram District, and in two tribal villages (35 house-holds) at the Anaikati Hills, Karamadai Block, Coimbatore District. On an average each family draws around 25 litres of potable water every day from each unit for their consumption.