Have you ever imagined that simple earthworms could be the solution for the drinking water problem in the world?
Matías Sjögren Raab from Chile has developed water treatment plants with biofilters. In these facilities, 15,000 earthworms per square meter of filters are "at work" devouring the impurities from the water. The remainder is 60 grams of pure humus per cubic meter of water, which can be sold at a good price.
These biofilter plants have several benefits: on one hand, it is possible to avoid the application of toxic desinfectants such as chlorine, which endanger human beings and the environment. This fact and their low costs in maintainment and electricity makes them very affordable. On the other hand, these facilities are especially suitable for small scale water treatment plants which are especially needed in the so-called "Third World". They are ideal for entrepreneurs on a local level who wish to solve problems of basic services while having good revenues.