Water Filters Abound

After the craziness and stress of the UNDP presentation, I was allowed to partake in the water-filter training that we also have going on this week.  Andrea, a consultant for CAWST, a Canadian-based firm that trains NGOs on water filtration, sanitation, and creating a successful project, is here in Bluefields this week providing a seminar for a few blueEnergy volunteers, employees, and partners.  Andrea has turned out to be especially cool - she speaks four languages damn near fluently, lives in Calgary, and is super cute!

Anyway, I've had the chance to really get my hands dirty with the water filter effort.  Since Bruno is leaving on Saturday, he wants to transfer all his knowledge and make sure that his last 6 months of energy don't go to waste because his project fell flat, so he planned this seminar right around his take-off date to make sure the momentum was in place.

What we've been working on some more is really perfecting the process of creating these filters.  I've already posted pics of our attempts at our first filter, but that one only half-succeeded.  Since then there have been 5 more attempts, and each time we get closer - but still no cigar.

This is another attempt at a filter. We've put the cement in the mold, and now just have to wait for it to sit before extracting it.

After 24 hours of letting it sit, the cement is both solid enough to remove the mold and have it not melt into a puddle, but soft enough to still come out of the mold.  The trick is making sure not to screw it up.  Here Octavio, Danny, and Charles are flipping the mold over to put the filter upright.

The guys then attach the extractor which screws into the inner piece of the mold and should pull it up slowly with a crank.

Here they go, cranking away.  This is actually uber hard to do.  We need about 4 strong dudes just to crank it around a bit.  Once it gets far enough out, they can lift it the rest of the way - but just the weight of the mold is itself quite heavy.

So this filter got stuck to the inner mold, and we had to break it out in order to save the mold.  Unfortunately.  We were very sad, since this was the first amazingly formed cement.  Damn... the grease wasn't enough.

Yay! A filter that worked. We managed to get it out of the mold, fill it with water, and have the water come out - meaning that the water tube was also in good condition. Schwweeeeet!

After two days of drying, the filter was ready for us to add the sand column on the inside.  Here you can also see the plastic splash guard that will prevent buckets of water from disrupting the delicate eco-system that is supposed to develop in the sand.

Putting sand into the filter.  This sand had to be pre-washed... although not for the reasons you would think.  "Washing" sand really means just taking out the smallest particles of the sand.  We actually want the biology (whatever there is) in the sand to be there because it helps to eat up all the bacteria and parasites that will come into the filter with the water.  The only reason we wash the sand is to make it slightly easier for the sand to pass through it - this decreases the absolute effectiveness of the filter, but makes it more practical.  If it takes three days for the water to pass through the filter, no one will want to use it.

After filling it with sand, we have to test the water flow.  A flow that's too fast means that we washed the sand too much, and the water will not be filtered properly.  A flow that's too slow means the sand wasn't washed enough, and although the filter will be effective, it won't be practical.  The trick is to find the balance.

Clean water! Whoo hoooo!