DIY Wood Mold for BioSand Water Filter System Is a Low-Tech Clean Water Solution

CC BY 4.0. OHorizons

This water filtration solution requires no electricity, has no moving parts, and can be built affordably with locally available materials.

Unless you've been hiding under a rock for the last decade or more, the fact that lack of access to clean drinking water and adequate sanitation facilities is literally a matter of life and death in many parts of the world should come as no surprise. And while there are more organizations than ever before working toward getting clean water to the people who most need it, and more filtration systems for both families and communities available now, we've still got a long way to go before the hundreds of millions of people around the world without access to safe drinking water no longer have to worry about getting sick from something we take for granted.

Fortunately, in addition to large-scale and high-tech water filtration solutions, there are also groups tackling the issue from an approachable, affordable, and DIY angle, such as the folks at the nonprofit OHorizons.

One effective option for water filtration is through the use of what's called a BioSand Filter (BSF), which puts natural biological processes to work to remove pathogens from contaminated water, and which is a low-cost, low-maintenance, and long-lasting solution. Originally developed in the '90s by Dr. David Manz at the University of Calgary, BSF systems are essentially a step up from the traditional slow sand filter, and are considered to be an effective method of treating water at the point of use, and one that can be built from local materials, right where it's needed.

BioSand Filter explainer

OHorizons/CC BY 4.0

"BioSand Filters (BSFs) use sand, gravel, and natural biological processes to filter out contaminants in water, making it safe for drinking. BSFs effectively eliminate cholera, typhoid, E coli, amoebic dysentery, and many additional pathogens that are harmful to humans. They’re a great low-tech drinking water solution." - OHorizons

BSF systems are usually constructed from concrete, which usually requires a steel mold to pour, but the materials and expertise for welding up a steel mold can be challenging and/or expensive to procure. What OHorizons has done to move the needle on BSF production is to develop an open-source DIY concrete mold made from wood, along with a full construction manual, which is freely available for anyone to download and use, enabling faster, cheaper, and easier access to a system that could potentially supply clean water for 20 or more years.

According to OHorizons, the cost for a steel mold can be anywhere form $500 to $2000, whereas the wood mold costs about $70 to $100, which can greatly scale up the impact from the same budget when compared with a steel mold.

Advantages of the OHorizons wood mold:
- Inexpensive ($70-$100/mold including cost of labor)
- Locally-Sourced Materials (all materials purchased in-country and easily replaced)
- Easy to use (no special skills or previous construction experience necessary)
- Durable (+50 filters/mold)
- Can be made off-grid and on-location. (no electricity required)
- Rapidly increases filter production capacity. It can scale!