Biosand Water Filter
Biosand water filters are what people in the development world call an "appropriate technology". What that means is that it is well suited for developing countries where things like electricity, education and complicated supplies might be limited.
The Biosand filter, simply put, is a concrete box with sand. It is constructed of locally available materials (sand, gravel, cement). It does not need electricity to work, and it doesn't need to have expensive parts replaced. Maintenance is simple and can be done by the filter owner. It's so simple even the youngest members of the home can use it.
When water is poured into the Biosand filter every day a biological layer starts to build up in the top layer of the sand bed. The "good microbes" in the bio-layer start to feed off of the "bad microbes" and develop an active little community. Organisms like worms and protozoa can't pass through the sand bed so there is a natural "die off" process that happens too. The biosand water filter can effectively filter out up to 99% of all microbes(bacteria, protozoa, viruses and worms), giving Haitian families an affordable solution for their water needs.
With a flow rate of about 5 gallons every hour each filter can treat enough water every day to meet the water needs of an average (8-10 people) Haitian home.
