Guatemala 2010: Building water filters

Three of our days down here have been spent building and fixing water filters. This was originally the primary ministry of the Kendalls down here in Guatemala: at first, Forrest built and installed all the filters himself. At left you can see a filter that's used by Forrest at the filter factory. It's really just a concrete box with a "nose" on the front - Ja and I think they look like tiny Easter Island heads. As explained in the wikipedia article, you pour dirty water in the top, and it filters down through the layers of "schmutzdecke", sand and gravel: when it reaches the bottom, it's clean. There's a small device to collect the water - a plastic bottle cap - and a plastic tube that carries the water up the side and out the end of the "nose". You can see the plastic tube sticking out in the picture at left.

Watching them, I was thinking how Forrest and Carol make such a great team installing the filters: Forrest sets them up, while Carol teaches the women how to use them properly. The latter part is extremely important, because although the filters are pretty tough, the biological filtration system needs to be handled properly. They need to use it regularly, keep water flowing through it (to ensure the schmutzdecke stays alive), regularly clean the spout, make sure they use clean buckets to catch the water, etc.

What many of the people will do without this training is actually fairly amazing: they will take their buckets off the ground, fill them with dirty water, pour the water into the top of the filter, then put that same bucket under the spout to catch the clean water (thus contaminating it). Or, they will take a bucket of clean water and then dip a dirty cup into the clean water. Or, they don't keep the lid on top of the filter and (as happened to one filter in Tzancha) there were disease-carrying cockroaches living in the top. So Carol needs to spend considerable time with the women explaining to them how to properly use the filters and keep the clean and dirty water separated and prevent contamination. Clearly, a lot of this has nothing to do per se with the filter: they need basic instruction in hygiene. Carol takes on most of this training, usually requiring the services of a local translator to translate from Spanish to whatever Mayan language that particular group speaks.

If there's any question as to why they need these filters, just take a look at the picture to the right. This is a picture I took looking towards upstream over the river that flows behind Forrest's water filter factory. Notice all the pipes sticking out of the wall of the housing units: those are sewer pipes, dumping raw sewage directly into the river. People either take water directly out of this river to drink, or at best use a municipal water supply which is barely processed. I also learned that the municipal supplies often stop working for days at a time, which means back to the rivers they go.

So, the filters are something they badly need whether they know it or not. After the filters are built, they have to be delivered and installed. As I said, they are pretty tough, but they have to be used properly to ensure that the bio layer continues working properly, and occasionally the filters themselves have problems. For example, while we were in Tzancha we learned that a number of the filters had developed a problem wherein the water went in clear and came out yellow and smelling bad (though tasting ok). So, part of the job of installing filters is going back periodically and checking that they are working properly, and replacing or fixing them when they are not.

The trip to Tzancha (where I met my young friend Sandra) was exactly this kind of "checkup" trip. On this trip, Carol took along a bunch of buckets with covers on top and a spigot on the bottom. I asked what they were and she said "bribes." What she meant was that she checks whether they've been using their filter properly and, if so, she gives them some kind of gift: an incentive to do it correctly. In this case, the bucket (shown at right). The bucket turns out to be extremely important: as explained above, it's important to catch the water from the filter in a clean container and then ensure the water is not contaminated before they use it. The bucket is perfect: they use it only for clean water, it has a cover to keep out flies, and a spigot so they don't dip their dirty cups and bottles into the clean water supply.

The construction process itself is quite interesting: they use steel molds in the shape of the filter, then surround the center part with chicken wire to give the concrete some strength in tension. Then they run the plastic tube down the side and pour concrete into the mold. After the concrete is cured, they remove the mold. At this point, the filter may be ready to install. I say may be because there are a variety of things that can go wrong, from cracks in the concrete to fixes that are necessary because of changing filter designs. In the filters at left, a change in design from the organization the Kendalls work with required us to cut off the "noses" of the filters so that the outlet tube was approximately an inch higher than where it was poured. So, we had to cut off the noses with a diamond blade saw and then patch things up with fiberglass cloth and epoxy resin. (The resin is the dark stuff you can see around the noses.) Also, a number of them leaked because they were incorrectly de-molded, so we had to patch the bodies up, as we did with the filter on the left.

This is clearly a fairly labor-intensive job, so the Kendalls have now trained a number of other people how to build and install these filters. I asked them how many filters they had put in here and they didn't know: over a thousands was the best guess (including all the filters put in by people they trained). That's excellent: teach other ministries how to fish instead of just giving them fish, and let them multiply the filters in this country that needs them so badly.