Bio-sand water pre-filter

The Cornell Cooperative Extension of Essex County InvenTeam invented small pre-filters to be used in conjunction with a bio-sand filter to provide up to 20 gal of clean, potable water a day to individual households in developing countries. The pre-filters protect the main bio-sand filter from silt build-up and provide the first stage for pathogen removal. They employ flood- drain technology to increase still water contact time with the sand. The pre-filters are constructed from locally available recycled materials at a minimal cost. Assembly of the bio-sand filter and pre-filters takes up to one day.