“No more stomach aches:” the power of the biosand filter in the heart of the Amazon
By Raul Guerrero, Global Water, Sanitation and Hygiene (WASH) Advisor
The Amazon River Delta in the state of Pará, Brazil
In the heart of the Amazon River Delta, life flows around water. Rivers connect communities, carry food, and shape daily life. Yet for many families, clean water remains out of reach.
When I first met Miss Jackie, a community leader in the Brazilian state of Pará, she welcomed me into her stilt house with the warmest smile. Her home sat above calm waters surrounded by pristine rainforest. But that beauty hid the daily challenge of finding safe water to drink.
Mrs. Jacquline (photo supplied with permission)
For years, Jackie relied on an unreliable tap on a neighbouring island. The long trip to fetch water often ended with disappointment and illness.
“I know how much people here suffer with unsafe water access. I am one of them,” Jackie told me. “I was born and raised in this place.”
Everything changed when Jackie met our friends from Xingu Mission, one of CAWST’s local collaborators. The team was visiting nearby communities, sharing knowledge, and distributing biosand filters. This simple, affordable technology turns unsafe water into safe drinking water using only sand and gravity. Jackie was curious. She asked questions, listened carefully, and decided to bring a filter home.
The results were immediate. No more stomach aches. No more long trips across the river. For the first time, Jackie and her family had clean water at home. With her energy restored, she began teaching her neighbours how to build and maintain their own filters. Today, she’s a leader in her community and living proof that when knowledge is shared, change flows.
A simple idea that keeps spreading
Recently, our team came across a photo from the early 2000s: three biosand filters being delivered by canoe through the Amazon. It was taken shortly after CAWST made the biosand filter patent and plans freely available to anyone in the world.
We trusted our instinct that open knowledge could go further than any single project. And it worked.
Today, there are more than 20,000 biosand filters in use across the Amazon and more than 2 million worldwide. These filters are built and maintained by local people, adapted to their communities, and passed from one generation to the next.
That is the power of CAWST’s model. We multiply impact through knowledge. Instead of focusing on short-term construction projects, we train and equip people to solve their own water, sanitation, and hygiene challenges for life.
Pictured above: Biosand filters being transported by canoe (image courtesy of Xingu Mission)
Clean water is just the beginning
Since 2001, CAWST and our partners have helped 72 million people gain better water, sanitation, and hygiene. Behind every number is a story like Jackie’s, one of health, dignity, and opportunity made possible through education.
This approach works because of people like you. Your donations fuel training, innovation, and the world’s largest online library of free WASH resources. They help us reach more communities, strengthen partnerships, and bring knowledge where it’s needed most.
Together, we can do more than we’ve ever imagined.
Because at CAWST, we know that clean water is not the finish line — it’s where change begins.
Help knowledge flow for generations
Your support helps families gain the skills and tools to manage water safely for life. Clean water is just the beginning. Give today and help millions thrive.
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