January 13, 2010 - workshop

In the morning, we planned for the workshop, which will cover the following main points:
1. Causes of water contamination
There are germs in the water. These germs can stay afloat in the water, but they also like to be attached to particles in the water. These germs make you sick.

2. Biosand filtration
A layer of sand can trap the particles in the water, removing most of the germs. We can flow dirty water through this sand layer to clean the water. However, the water can also carry sand with it into the outlet. In order to trap the sand inside the filter, we can layer some larger gravels at the bottom of the filter, since the gravels can admit the water but not so much sand. However, there are also free-floating germs in the water, which are too small for the sand to remove physically. Incidentally, over time, the living matter already present in the water gets trapped at the water-sand interface, forming a living bio-layer. These living things like to eat up the free-floating bacteria, which makes the water even cleaner. However, this bio-layer is very sensitive, and can die easily. In order to keep it alive, it needs to be always immersed in water---it is important to keep a standing water. To do this, we need to engineer the water tube such that it comes up to the top, so that we do not need to constantly input water in order to keep standing water.

3. Solar pasteurization
Many people boil their water, since the heat kills the germs. Instead of getting heat from the firewood, we can also get heat from the sun. But the heat from the sun is much less intense than that from the firewood, so we will need to leave the water out in the sun for a long time before the water can be safe to drink. One simple way to do this is to fill a transparent plastic bottle with water, leave it out on the rooftop for one day on a sunny day or two days on a cloudy day. This method is called SODIS. A more advanced way involves building reflective surfaces (e.g. using aluminium foil) to reflect and concentrate the sunlight in order to heat up the water more efficiently. This method is called a solar cooker. The downside to the solar methods is that these are limited by sunlight and cannot be used when it rains, and that it takes a long time to treat water.

Joseph came later in the morning, and we went with him to visit Peter's household. The family has 7 children and 2 adults, and uses about 5 jerry cans of water collected from BH4, of which 1 jerry can is used for drinking, both in the form of tea and of water. The family sometimes boil their water, nsuing firewood collected from the forest, because boiling water can kill germs. The family is unwilling to help us test the prototypes, though they express interest if we construct the prototypes ourselves and have them test it. This is fine---we have three families. And Joseph also expressed some interest in helping us test a Biosand filter.

Upon returning to the clinic, we went through our workshop plan with Joseph (our translator) to make sure that he understands all the key concepts. Of all the points, the most difficult to score is the development of the bio-layer, which is not really intuitive. Joseph thinks that most of the people would be interested in SODIS because this is a simple method. In the mean time, we filled the black-painted jerry can with Nalongo water and put it into our solar cooker. We also layered a plastic film on the top to cover the cooker such that there is less convection. The clinic's cook saw our set up; Kevin explained the idea to her, but she remains unconvinced that it would be powerful enough to treat water.

We read the results of the Petrifilm tests from water samples gathered at 14:30 on 1/11, from BH4 and P1, as well as control (C), which is our drinking water. The results are given as follows. We strongly suspect that we have accidentally mislabelled the BH4 and P1 samples:
BH4 Enterobacteria sample 1: 36 (many dots without bubbles)
BH4 E. coli/coliform sample 1: 0/15 (many dots without bubbles)
BH4 Enterobacteria sample 2: 59 (many dots without bubbles)
BH4 E. coli/coliform sample 2: 1/23 (many dots without bubbles)
P1 E. coli/coliform sample 1: 0 (5 dots without bubbles)
P1 Enterobacteria sample 1: 1
P1 E. coli/coliform sample 2: 0
P1 Enterobacteria sample 2: 0
Control Enterobacteria: 0 (about 3 dots without bubbles)
Control E. coli/coliform: 0 (about 40 dots without bubbles)
Later, we sifted through our new pile of sand, with the constructive or destructive help of some kids, and it was another arduous process. This process continued until about 3 p.m., at which time we had a late lunch of rice, posho (??), and ground nut sauce.

We prepared some "posters" for the workshop (consisting of half A4 papers with drawings and some elementary Luganda labels with the help of John and Francis). One woman (whom we approached earlier in our interviews) appeared at 3 p.m. (but we didn't find out until about 4 p.m.) and waited for about 1 hour. Then at 4 p.m. about 4 more people showed up. Joseph, whom we had gone through the workshop materials this morning and was supposed to translate for us, went to look for the other households (whom we talked to yesterday). So we started, with John as our translator. More people trickled in, and a few went away, but the maximum was about 11 people, which was beyond our expectations (we had expected the 3 families from yesterday, plus maybe 2 more add-ons from one of the previously visited families).

John first started with reference to Helen and Becca's last meeting, in terms of Petrifilm tests and the recommendation to boil water. We emphasised that we are doing tests, and do not currently know which method works well for people. We will give them ways (e.g. Petrifilm) to monitor the water: we do not want them to drink water treated using our technology unless we know that they are as good as boiled water. We then had John go through the ideas of Biosand filter, SODIS, and solar cooker. We had some demonstrations, including the Rwanzori water bottle sand filter from yesterday, the empty bucket with the outlet pipes attached, the four SODIS plastic bottles which had been sitting on the roof for 2 days, and the solar cooker with the black-painted jerry can of water (which we put in this morning from Nalongo water). People were caught up a little on the idea of using the principle of hydrostatic pressure to maintain a standing water to keep the bio-layer alive (it was not an intuitive concept, and John needed to demonstrate with a kettle). People also had a chance to feel how warm the water in the solar cooker was. Even though we took it out of the sun when we started the workshop (it was getting cloudy and thundery but never rained), about 1.5 hours into the workshop, the water was still very warm---perhaps about 50C---how we wish we had a thermometer!

At the end, we took down the names of the people who attended, alongside with their interests (either bucket or cooker; no one chose SODIS). We explained to them that due to the limited time, resources, and scope of our test (we don't know if any technology works well), we can only accommodate a limited number of households. But here is a complete list of the participants with their preferences:
Kyeyune Jawada - cooker
Mbazira Edward - bucket
Gertrude Buyoudo - cooker
Richard Njagala - cooker/bucket
Eddie Muwuza - cooker
Nyanbi Najibu - cooker
Ssebulime Medi - bucket
Jjavuga - bucket
Niusima Noleda - bucket
Bafeyo Hadija - bucket
Joseph - bucket/cooker

As can be seen, the divide between the cookers and the buckets are about half and half. We plan to take perhaps 2 cookers and 2 buckets. This includes Eddie (cooker), who is quite involved with the clinic, and Joseph (bucket), who has been translating for us and knows what we are doing. We are impressed by a lady (Gertrude Buyoudo) who showed up at 3 p.m. and asked several questions. The fourth one (a bucket) is to be decided. Our plan is to go to Masaka tomorrow to look for the materials needed to construct the prototypes---wish us luck!
We then did some Petrifilm tests with the SODIS water (drawn from P1 and BH4, in both big 1.5 L and small 0.6 L bottles) as well as the solar cooker water (drawn from P1). Finally, we got together to talk more generally about our goals and plans over the remaining two weeks. It is important to push the workshop/prototype before the medical mission arrives. Then, based on our discussions with the different households, and based on Mike's inclination, we want to look at what may be wrong with the BHs, and find possible ways to address these efficiently.