last three days at tulti

Veintiuno a veintitres de septiembre
Wow, what a great week! I think this was the best program we have ever given. The people in the community were interested and enthusiastic, the weather cooperated mostly and each day we had something different to do.

On Wednesday Susan and I gave a workshop on making and using solar stoves. They are simple, cheap, and they really work when the sun shines. The audience is often women, madres de familia. My emphasis is on using the stoves to pasteurize water, but they are more interested in using them for cooking. The stoves certainly are good for both.
I start the program with a discussion about water and contamination, and how you can't tell if your drinking water is safe or not. No one will admit that their families have diarrhea, but when I bring up that millions of children die every year because of it there is an immediate show of understanding. from the mothers. I have a chart that I pass out that shows of the different disease organisms that can be in water. It also shows that they can be killed by heating the water. I need to work on the chart some more but the point is that by heating the water in a solar stove you can make it safe to drink.
WAPI's (Water Pasteurization Indicators) are small plastic cylinders with a special wax inside that melts at the temperature of pasteurization, 65 degrees C., and shows that the water has been heated at least that high. The chart shows that the dangerous organisms are killed below that temperature. The WAPI's are on a short thin wire and are dangled in the pot of water being heated. When the wax melts the water is safe to drink. When the WAPI is removed the wax hardens and can be used over and over, many times.
Then we went outside to look at a couple of solar stoves we had set up. It was a warm, very sunny day and the stoves in about an hour and a half had already heated the water to the temperature of pasteurization and the wax in the WAPI had melted. Susan had put some vegetables into a pot to steam and they were cooked and ready to eat. The mothers were also impressed that the stove was cool and not dangerous while the pot was hot.
I had a big pile of cardboard and each of the people at the workshop who wanted a stove picked out several matching boxes and we began to construct the stoves. The process is that they duct tape several boxes together and cut them to approximately match the commercially made one I brought. After the participants have a good design they use diluted white glue to glue aluminum foil to their stoves to make them reflective. The stoves sometimes turn out sort of inelegant bu they work as well as the commercial ones. Everyone is down on their hands and knees cutting and gluing, to me it looks like a third grade art project, but the ladies are quite proud of their creations. I asked that they leave their stoves there overnight to dry, and I gave each participant a WAPI and a copy of the temperature chart that shows the different organisms killed by pasteurization. Six women and two men made stoves.



On Thursday, the program was “rocket stoves” or estufas cojetes. They are small wood burning stoves that are called rockets because of the roaring noise they make when fully burning. They are made from a 5 gallon metal can and a stove pipe elbow. The flame is concentrated in the center of the stove and burns so hot that there is little smoke when it is working well. The stove is insulated with wood ash so the outside doesn't get hot. The temperature is hot enough to cook tortillas on a metal plate called a comal.
I had more of a struggle to get the supplies for the rocket stoves. The people there work as recyclers there at the dump picking through the garbage so everything has value. Wen you see old ladies scratching at the dirt to pick up bottle caps to turn in for money, you know no one will be able to “donate” a 5 gallon can. I went through the community and purchased the old scrap cans we needed. Stove pipe elbows are also relatively expensive, in the range of 15 dollars in Mexico. The original method calls for cutting off the two crimped ends of another piece of stove pipe, using them for a sort of chimney, and discarding the rest. I demonstrated how it is possible to make your own crimps an put the pieces together, not wasting metal stovepipe.
This class had more men and they tended to do most of the metal cutting while the women watched. It's hard to cut round hole out of the middle of 5 gallon can, so I had some “aviation” stye snips that can cut in a circle. Even with those, it take a little practice and the metal has all sorts of sharp edges so I insisted that everyone wear some of the gloves I brought for safety. I made a mistake and cut one of the holes in the wrong place. Rather than throw the can away, one young guy decided to modify it and made it into an extra chimney to take away any smoke. I don't know if it works any better, but it sure looks different.
I gave the same lecture about bacteria as the day before and everyone got a WAPI and a chart. We made five stoves but couldn't finish them because we lacked enough wood ash. There at the dump people burn scraps and trash for cooking and the ash is dirty and full of stuff. I had enough for one stove, and one person put dirt in his instead of ash. Dirt is heavier and doesn't insulate as well as ash but he wanted to see if it worked.

Friday was the big day for us, the workshop on water testing where participants come from other organizations and we go into a lot more detail about microbiology and water testing. It's important to me that they take the testing seriously and work to do it accurately. I always feel responsible that they are telling families if their water is safe to drink and I don't want them to make a dangerous mistake.
In addition to Amextra, I had two other organizations respond and say they wanted to send some of their staff. SARAR-T is a non-profit whose focus is ecological sanitation. They are big advocates for composting latrines and gray water recycling. Several years ago Susan and I visited their program in Tepoztlan near Cuernavaca along with some others including Gaudencio and saw lots of different latrine designs and ideas. The people there are very nice and include engineers and others dedicated to their program. Over the years I have kept in contact with them and was honored to have them attend my event.
The other organization, Isla Urbana, is a group working in Mexico City on problems of rain water recycling for drinking water. I wasn't familiar with their work, but found out that they had been trying to learn about water testing for a while. They have been using more complicated methods for water testing than I advocate and wanted to learn different ways to monitor their water quality. Also, I teach simple ways for families to make their own water safe and so that also was interesting for them.
We all met at the Hotel Ibis Friday morning, and Gaudencio and another community member Luis brought everyone out to Tulti in vans. In all there were 10 participants plus some Tulti community members. Even though it makes it more complicated, I like to hold the workshops in the communities so that locals can attend as well, and it makes my program more grounded and realistic. We held it at the community center and this year I had a new “power point” presentation to give. Last year in Guatemala I had to put together a last minute presentation, so this one at least doesn't look so cheesy.
First I talk about basic public health and the diseases associated with drinking water, typhoid, cholera, shigella dysentery and all the problems and deaths they cause. The fact is that it's very complicated to test for these diseases, and so the UN and others advocate testing for a marker or indicator of contamination, something relatively simple that can so that the water is safe to drink or not. The organism we test for is E. Coli in the water. It comes from fecal contamination and is always present when the water contains other disease causing bacteria.
Then the participants learn to interpret testing results. We use two different tests, a plate type test called Petri Film a fluorescent tube assay called Colilert. They are both quite sensitive and accurate, down to one E. Coli bacteria in 10 mls of water. They are not difficult to interpret, but testers still need practice. I showed them several different results of samples that I had tested earlier in the week and we practiced with them so that each person could look at them and correctly state whether the water was safe or not.
After that, they learned how to test samples ourselves, using basic laboratory techniques of pipeting and measuring. Exactly one ml of sample has to be accurately placed on the Petri film plates and spread evenly for the test to work. It takes a little practice but eventually everyone could do it. Then we set up real water samples that they had brought with them. I like to have people bring samples of the water they are drinking, it focuses their attention on the results.
The test samples have to be incubated over night at 37 degrees C., body temperature. I give each person a zip lock and tell them they have to keep the sample warm under their clothes at body temperature or it won't work. This is usually a humorous moment but it's important. If they don't keep it warm enough, they might interpret the results as being negative – no growth- when in fact it was their mistake.
By then it was lunch time and we had a really nice lunch served by Amextra to everyone. During the lunch hour the organizations shared their work with the group, which was nice. I think everyone appreciated the different things everyone else was doing. I had planned to show off the rocket stoves and solar cookers in the afternoon, but Gaudencio was so enthusiastic about them that he stole my program and fired up the rocket stove early to make coffee for everyone. This is the second year in a row that it was rainy on the day of the big workshop when I wanted to show off the solar stoves as well. In reality, in climates that have rainy seasons like Mexico and Guatemala, solar stoves have to be backed up by some other method, like a rocket stove, for cooking and water pasteurization.
Instead Gaudencio took everyone on a tour of his work there in Tulti. He has done a great job of rain water recycling and he also has fixed up the schools latrine and wanted to show them off. He's very enthusiastic and a good salesman so everyone appreciated his tour. It's a very different environment there at Tulti with the people living in extreme poverty on the garbage dump so he took the participants on a bus tour of the community as well. Finally, we cleaned up the community center and returned to the hotel by about 4:00.
I think everyone enjoyed and learned from the workshop. I got several comments about how they might change or improve their programs as a result of what they learned, so that was very satisfying to me. I provided testing materials for all of them so that they can continue water testing in their own communities, and each person took home a WAPI to examine and play with. If they want to start providing them to families in their own projects I can arrange for them to get all they want. I have everyone's email and I will follow up to see how they are doing on their projects.
In all, a long, tiring great week!