Biosand Water Filters
A new biosand filter!
The availability of potable water is decreasing as the world’s population increases. In Cambodia, 1 in 7 children die before the age of five from preventable diseases such as typhoid, malnutrition, malaria, dengue. The common denominator in many of these is waterborne illness.
To address this issue Trailblazer is constructing and providing bio-sand water filters. They are a low cost way to provide potable water to impoverished areas from any water source (i.e.: pump wells, pit wells, rivers, ponds).
Our bio-sand water filter project is a relatively new technology to Cambodia. The bio-sand filtration systems are easy to construct with locally available materials, install and maintain. They are an excellent alternative or compliment to pump wells. One glass of bad water impacts an entire family through lost wages, transport, medical treatment, medicine, and possible even death. A bio-sand water filter effectively removes the dangers of bad water and its effects.
The filter consists of a layer of gravel, a layer of course sand, and a layer of fine sand. There is a plastic diffuser plate above the water level to avoid disturbing the naturally occurring bio-layer. It is the bio-layer which holds the key bacteria essential to removing biological pathogens and parasites. Water travels through the layer of biologically active sand and gravel which traps and degrades sediment, parasites and 98% of bacteria.
Operation and maintenance is simple and within the capabilities of any user. Water poured through the filter processes at a rate of .6 liters per minute, which provides water fast enough to keep up with a family’s demand for clean water. Each filter can optimally filter 50 to 80 liters of water per day.
The bio-sand water filter is made of cement at a total construction cost of approximately $50 USD per filter, including the bio-sand media and a proper storage container. The Trailblazer foundation charges the family who receives the filter $2 to ensure that they are committed to using the purification system.
Community stewards are selected to maintain bio-sand water filters in each village. These stewards are instructed on proper set-up, maintenance and water sanitation education, and pass this knowledge on to village residents using the water filters. It is exciting to see this technology successfully spreading out to the rural areas with the greatest need.