Since we are posting for this week about water in Kenya, let us explain what a bio-sand filter is, how it works and benefits to the communities where they are placed.

First, what is a bio-sand water filter?

It is a water treatment system using a slow sand filtration process. Bio-sand filters remove pathogens and particles from water using biological and physical processes that take place in a sand column covered with a biofilm (a layer of germ eating bacteria). It is a concrete container a bit larger than a office water cooler that is constructed by Kenyans (with Mark n our kids) using locally sourced materials.

Next, how does it work?

After the concrete case cures with an inset plastic pipe, it is filled with layers of washed sand and gravel. Dirty water is poured into the top of the bio- sand filter, where a diffuser plate (made by our Kenyan friend, Steve) evenly distributes the water over the sand bed layer. The water travels down through the sand bed, passes through multiple layers of gravel, and collects in the plastic pipe at the bottom of the filter. The clean water then exits through the plastic piping for a family to collect in clean containers.

The removal of contaminants and disease causing agents is possible due to a mixture of biological deprivation and natural filtration. The organic material in the dirty water is trapped at the surface of the sand bed, forming the layer of germ eating bacteria, which actively removes pathogens and contaminants. The water produced with the bio-sand process is tasteless, clear color, odorless and safe for drinking.

Finally, what are the benefits?
Studies have shown the bio-sand filter can remove more than 90% of bacteria and 100% of parasites, dramatically reducing the occurrences of water-borne diseases. Because of the filters’ effectiveness at increasing the safety of water, the ease of use/maintenance and lack of reoccurring cost, it is considered a suitable water treatment for developing countries.

Globally, hundreds of millions of people are trapped in a poverty cycle of chronic disease because they lack access to safe drinking water and basic sanitation. The statistics are unsettling: over 1.8 billion people are drink contaminated water, while 2.4 billion people lack access to basic sanitation. We are helping Kenyan use bio-sand water filters, coupled with the gospel message of hope in Jesus - the Living Water - to bring affordable, sustainable potable water solutions with a focus on salvation through Christ.