Bio-Sand Water Filters

I was down near the city of Corumba’ Brazil the last couple of weeks. This is the base of our work with the extremely poor folks who live along the Paraguay River basin and Pantanal wetlands. As I noted in other posts my wife and I are involved in a medical boat work there that brings healthcare services to these remote and forgotten folks. One of the primary causes for their many health issues is that they have no access to clean drinking water at all. So all manner of preventable diseases cause no end of suffering for these unfortunate folks. A primary cause of childhood death is simple diarrhea. One of the first goals we had in coming down here to live and work in Brazil was to find a way to solve this problem. Amazingly, we found an answer to our prayers by being introduced to the great folks at Living Water International, based in Houston TX. So last week we took the time to learn from two of their experts on how to make simple water filters for these folks. You can click the video clip above to see how it turned out. If you want to know more, follow me after the jump. I have some more pictures, too.

It’s all very simple and amazingly inexpensive- around $40-50 per filter and a single filter can serve an entire family. First you make a concrete box with a PVC pipe that runs back up the side of it. You fill this box with clean gravel, clean medium sized pebbles and clean fractured sand. Then you pour water in. That’s it. The sand/pebble/gravel mix percolates out the solid contaminants like metals, suspended solids, etc. Because the sand in the box stays submerged (this is due to the PVC pipe running back up above the interior sand level and the water in the box stays at that level) a layer of bio-mass grows out of the ambient bacteria. This bio layer survives by eating the bacteria, viri, amoebas and parasites that exist in the dirty water. So in goes yucky water, good bio stuff in the sand eats the unwanted bio stuff in the water, the sand and gravel filter out the rest and -ding!- clean water. 99.9% clean as confirmed by tests. It’s an amazingly simple, easy, low maintenance, very low cost clean water solution. It can filter about 1 litre of water every 1-2 minutes. Our goal is to get one of these in every home along the 200 mile stretch of river we serve. And, Lord willing, we’d like to see the program expand to meet the need in other areas in Brazil. Often there’s plenty of water, but it’s not fit to drink without treatment.
Anyhow, we’re excited to see this implemented here. We’re starting by installing around 10 of these in homes pn he river in mid September. After we see how that goes and make any adjustments we’re off to try and get more done. Here’s some pix, just for fun!

We made a steel mold for making the concrete filters. The fellow in the hat is Pr. Carlos. He’s in charge of running the Pantavida medical boat work. The fellow next to him is the boat captain Giovino. He was born along the river and has a huge heart to help his people. The fellow standing is Rene from Living Water of El Salvador. He oversees their bio-sand filter program, which installed over 1000 of these things in rural El Salvador last year. His boss, Paul (another Yank like us) came along to help us with the larger stategic planning initiatives for our program. We also had a pastor from our local church with us - a fun guy named Belmiro. He’s studying water treatment and has ideas for doing this in our part of Brazil here. And none of this would have been understandable without our great interpreter, Marcy. She made the whole Portugues-English-Spanish thing work so we knew what was going on!

Anyhow, after the mold is assembled, then you mix up some concrete the old fashioned way.

Pour it in and let it set overnight.

The next day the filter is ready to be extracted from the mold.

Belmiro washing sand for the filter. His favorite job.

After the concrete cures for another day or so you fill it with the clean sand & gravel in layers. It’s now ready to start putting water in.

Here is a before and after. The dirty water on the left is right out of the Paraguay River. People just walk up to the river with a cup, scoop that brown stuff up and drink it. Nasty! But it’s the only thing that have. Until now.

The water that comes out is clean enough for me to let my little boy play with it. He came along to keep us all entertained.