Five filters delivered. More can follow.
Status as of September 28, 2026
We paid for five filters in April 2026. Trailblazer Angkor built, delivered and installed them, and trained each family to use and maintain them. Byran Fuhrmann visited Trailblazer’s workshop near Siem Reap in May 2026 and saw filters being made.
- Meet the partnerOct 2025
- Fund 5 filtersApr 2026
- Delivered & trainedMay–Jun 2026
- More filtersIf donors wish
- Sep–Oct 2025Introduction to Trailblazer Foundation and a first call about its biosand program.
- Feb 2026CWH board approves $500 for biosand filters.
- Apr 15, 2026Five filters funded.
- May 13, 2026Byran Fuhrmann visits the Trailblazer workshop near Siem Reap.
- May–Jun 2026Filters delivered to families; photos shared by Trailblazer.
- NextA larger campaign if donors want to fund more filters.
From the field
Photos: Trailblazer Foundation and Clean Water Help (workshop, May 2026).
Learn more
The short version is above. Open any section for the details, or download the short report below. For the science behind these filters, read our brief on gravity and biosand filters.
How a biosand filter worksSand and a living layer, no power or chemicals
A biosand filter is a concrete box filled with layers of gravel and fine sand. Water poured in the top trickles down slowly. A thin living layer that forms on top of the sand, plus the sand itself, removes most bacteria, parasites and cloudiness. The filter needs no power or chemicals and lasts 10 years or more.
The limit: it does not remove dissolved chemicals such as arsenic, and it works best when used every day. Families are trained to use it daily and store filtered water in clean, covered containers.
Why TrailblazerMade locally, delivered with training
Trailblazer Foundation’s Cambodian partner, Trailblazer Angkor, makes the filters in its own workshop near Siem Reap, delivers them, installs them and trains each family. Families contribute a small amount to a village fund, which builds ownership. Each filter costs about $100 and serves about 7 to 20 people.
What we fundedFive filters for farming families
In April 2026, CWH funded five filters for rural farming families outside Siem Reap. Trailblazer sent photos of each installed filter with its family in May and June 2026.
Project ReportCambodia: Biosand FiltersDownload the full project report
A short report on what we funded, how biosand filters work and what they cost. Updated September 2026.
The team behind it
Volunteer scientists and engineers donating their expertise to this project. Click anyone to see their work.
