Clean water for kids
Initiative: Bio-Sand Water Filters – New & Reinstallations – Siem Reap Province – Cambodia Rotary
Supporting water projects is something the Rotary Club of Comox Valley feels very passionate about because the difference that access to water has on people’s lives is truly incredible. Children are no longer sick, school attendance rates go up and families feel so proud to have a water filter installed in their village.
Our club members decided that our second ever international project would address the clean water needs of rural communities in Cambodia. To do this we worked with the Trailblazer Foundation to provide bio-sand water filters to villagers in the area around Siem Reap. The work would involve building and delivering new filters as well as refreshing some existing filters by reinstallating the internal filtration materials on site.
The Bio Sand Water filters used by the Trailblazer Foundation were designed and developed by a Professor of Environmental engineering, Dr. David Manz from the University of Calgary. The beauty of these filters is that they don’t need electricity or fuel to work. They’ve been used in Siem Reap Province, Cambodia since 2005 and each filter can provide clean water for around three families (approx.15 people). A filter typically lasts 10 to 12 years before it needs cleaning out and fresh materials reinstalling (sand & gravel).
How does it work?
The outside of a filter is made of concrete to make it durable. There’s a lid on top of the filter to prevent dust and debris from entering. A diffuser plate is placed below the lid on top of the filtration materials. This plate protects the top of the sand and spreads the water evenly through its pattern of holes when the unclean water is poured in. A biolayer builds up between the sand and the diffuser, which is the key to how the filter works. The biolayer consists of good bacteria that remove pathogens and produces clean water. Sand and gravel make up the rest of the filter. There are two layers of gravel and one layer of sand. The gravel layers hold the weight of each other and the sand. The clean water collects at the bottom of the filter and enters the outlet tube as it is “pushed out” by more unclean water being put into the filter.
Our club worked hard to raise enough funds to support the Trailblazer Foundation in Siem Reap. We were just a little bit short of funds and so being a club who truly believes in One Rotary, we reached out to a Rotary club in England; Crompton and Royton Rotary. After a presentation to their members, they stepped up to help us reach our goal.
Two Rotarians visited the project in January 2025. During this visit, one day was spent at the offices and construction facility in Siem Reap reviewing the scope, budget, receipts and progress to date. The remaining time was spent in the field delivering new filters and carrying out reinstallations of old existing filters in remote villages. This included training of villagers to ensure correct use and sustainability of the water filter. Based on the reinstallations seen in the villages it was clear that the filters are in constant use and can last at least 10 years before reinstallations are required. The overall visit was extremely productive, and the visiting Rotarians had a high level of confidence in the outcome of the project in terms of scope, cost, schedule and sustainability.
The project took three months to complete with 197 reinstallations and 50 brand new filters across six villages being delivered. It is estimated that these 247 filters will provide clean water to over 1,200 people. It is astonishing to think that this is as little as $16 per person for clean drinking water for at least ten years!
A big shout out to Barbara Barney, our District Community Grants Coordinator, who works tirelessly to help people understand what’s needed to ensure a successful and sustainable project! Thank you Barbara………. what would we do without you!
