Project Report · Cambodia

Biosand Filters for Farming Families near Siem Reap, Cambodia

A short report on the five biosand filters Clean Water Help funded in 2026 through Trailblazer Foundation, how the filters work and what they cost.

Complete

UpdatedSeptember 28, 2026

PartnerTrailblazer Foundation / Trailblazer Angkor

Prepared byClean Water Help volunteers

Webcleanwaterhelp.org/projects/cambodia-biosand

Clean Water Help is a 100% volunteer-run 501(c)(3) nonprofit (EIN 99-0765687). Founders cover all operating costs, so 100% of public donations go to projects. Numbers are current as of September 28, 2026. Photos are shared by partners with permission; names of private individuals are withheld. impact@cleanwaterhelp.org

At a glance

LocationNear Siem Reap, Cambodia

PartnerTrailblazer Foundation

FundedApril 2026

Filters5

CostAbout $100 each

CWH roleFunding

5filters funded

$500total

10+years each

7–20people per filter

1 Executive summary

Key findingFor $500, five farming families near Siem Reap received locally made biosand filters, installation and training. Each filter serves about 7 to 20 people and should last more than 10 years.

CWH met Trailblazer Foundation in September 2025. The board approved $500 for biosand filters, and CWH funded five filters on April 15, 2026. Trailblazer Angkor built, delivered and installed the filters and trained each family. CWH’s executive director visited the workshop near Siem Reap on May 13, 2026.

What happens next

Offer donors the option to fund more filters through Trailblazer.
Consider a larger campaign if there is donor interest.

The issue to watchDaily use. Biosand filters work best when used every day and when filtered water is stored cleanly. Trailblazer’s training and follow-up address this.

Key numbers and how solid they are

Each number is labeled by its basis: Measured counted or tested, Reported reported by a partner or a document, Record from our own payments, contracts and correspondence, Estimate a calculation or assumption, Planned a plan or target, not yet done.

Item	Value	Basis	Source
Filters funded	5	Record	CWH payment, Apr 15, 2026
Cost per filter	about $100	Record	Trailblazer
People per filter	about 7–20	Reported	Trailblazer
Filter life	10+ years	Reported	Trailblazer

2 Background and progress

The partner

Trailblazer Foundation is a US nonprofit working in rural Siem Reap Province. Its Cambodian partner, Trailblazer Angkor, makes biosand filters in its own workshop, drills wells and supports farmer groups. Families contribute a small amount to a village fund.

Concrete filter bodies curing at the workshop — Filters curing at the workshop, May 2026

A grandmother and granddaughter with their filter — A family with their filter. Photo: Trailblazer

Timeline

Sep 26, 2025Introduction to Trailblazer Foundation.
Oct 7, 2025First call.
Feb 2026Board approves $500.
Apr 15, 2026Five filters funded.
May 13, 2026Workshop visit.
May–Jun 2026Photos of delivered filters received.

3 Technical foundation

How it works

Water poured into the concrete box trickles through fine sand and gravel. A living layer on top of the sand and the sand itself remove most bacteria, parasites and cloudiness. No power or chemicals are needed. The filter does not remove dissolved chemicals such as arsenic.

Decisions and the options we set aside

Decision	Options considered	Why
Fund through an established local maker	Buy imported filters	Local production, delivery and training make filters last.

Risks and how we respond

Risk	Level	Response
Irregular use	Low	Training and follow-up by Trailblazer.
Re-contamination in storage	Low	Clean, covered containers.

4 What we learned and what is still open

Small, well-run partners can turn modest gifts into lasting results.

Open questions

Would donors support a larger biosand campaign?

5 How you can help

Fund a filter

$100 funds a filter, delivered and installed with training.

Contact: impact@cleanwaterhelp.org

References and sources

Trailblazer Foundation. thetrailblazerfoundation.org
Clean Water Help payment record, April 15, 2026.