An SIM project is introducing the first household use of bio-sand technology in Bolivia. A bio-sand filter is a locally constructed, tall concrete box filled with very carefully selected sand and gravel. A biological layer develops in the top few inches of the sand and becomes populated with “predator” organisms that feed on the harmful organisms in the contaminated water. What the predators don’t eat, the fine sand filters out. No matter how contaminated the water is when poured in, it comes out completely safe and purified.
Having successfully completed the initial phase for introducing household bio-sand filters, we now plan to greatly expand their availability. We have found that bio-sand filters are being built by even the poorest householders. The filters are easy to maintain, last more than 20 years and are widely accepted.
The cost of materials is US$30—half paid for by the household and half by our program called Safe Water for Impoverished Communities. Each $15 donation enables us to provide another entire family with safe water for many years.