from the field: clear in Cambodia.


We’re back from a field trip to Cambodia, where we support a BioSand Filtration program to serve families with clean drinking water. Here’s the update from Jonna, our Water Programs Manager:

After a few days talking best practices at the Asia Regional Workshop for Cambodia, Myanmar and Indonesia (led by our partnering organization in Cambodia, Samaritan’s Purse), I set out to monitor our BioSand Filter (BSF) program in Kampong Thom Province. Some families here received their BSFs years ago; others are now building brand new ones.

A little background on the technology: the BioSand Filter is quite literally a cement box with chambers for filtering dirty water. These contain gravel, two layers of sand and a film of microorganisms that eat up to 99% of harmful bacteria in the water poured into them. We cover the material costs of each BSF; the families who receive them contribute $5 to the program. Family members also receive hygiene training by Clear Cambodia, the local org working with Samaritan’s Purse.


The most exciting aspect of visiting our projects in Cambodia is always “the factory” — when an entire community comes together to build BSFs for each family in the program. It’s an assembly line of sorts: Clear Cambodia’s construction staff keeps the process running efficiently, but the event feels less like a mill and more like an active community meeting.


We walked up to find more than a dozen members of Kar Koh commune mixing cement, pouring it into concrete BSF molds and tossing sand with water to get the perfect consistency for filtration. A few days after our visit, these very BSF’s would be installed outside each household, ready for use within three weeks (the bacterial layer takes that time to fully form).

old source

As some work diligently on their new filters, others are living the difference with BSFs they already made. A number of Kampong Thom residents told me that they used to drink water from an unprotected well, hand-dug pond, or open rainwater jar, which would often make their children ill. Now, these families use their BSFs for drinking water — but they also use them to wash their hands, vegetables and dishes and to clean out water storage containers. Using safe water for all day-to-day activities like this can significantly reduce the chance of waterborne disease.

I also met families who now save money they used to spend on clinic fees or time they used to spend traveling to health centers kilometers away. I talked to children who now carry a bottle of BSF-filtered water to school, and several adults noted that they tote a bottle of filtered water with them whenever they head out to the rice fields for work.

classroom kids

Next stop: Svay Kal Primary School, in a district where many families already have their own BSFs.

We asked, ‘How many of you have a BioSand Filter at home?’ — A couple dozen hands shot up.

Here, students enthusiastically discussed safe hygiene and sanitation practices, and then rushed into the schoolyard together to practice effective handwashing. As we’ve learned in other programs around the world, teaching young students safe hygiene practices is pretty effective: not only do they reinforce their training by putting it to use among their peers every day at school, they also bring these practices home to their families.

jonna in kar koh

We’re working with SP and Clear in five provinces of Cambodia — and we’re excited each time the BSF program rolls out to more and more families. We’ll keep you updated as the program grows.

– Jonna Davis, Water Programs Manager
as told through Mo Scarpelli, Multimedia Producer

Want to learn more about the BSF? See past blog posts about our work with Samaritan’s Purse in Cambodia here >

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