| I know it's been a while since I've posted... things have been going really well, but they've also been really busy lately (as if that were something new ;). I'm in Zambia at the moment for user research. It's great because I have some interesting new pictures to post, but not-so-great because I only have access to very slow internet about once every three days while I'm here. D'oh! We'll see how many pictures I can get uploaded once I get to a connection.
In any case, I'm here to talk with, observe, take pictures of, learn from and understand small farmers in Zambia. I'm staying in a hotel about 12km outside of the capital, Lusaka. From here it's another 20km or so out to the field sites I visited yesterday. I talked to a couple of farmers, but not many (hope to remedy that today). IDE has a manual well-drilling team that's training out near there though, so I got to see them in action. A bit more explanation...
There are pretty much two main options for accessing water that's more than a few feet underground: a hand-dug well or a drilled well. A hand-dug well is just that... dug by hand by someone who is down the hole with a pick, a shovel, or some other hand tool. This method has a couple of limitations, but is most hindered by the fact that the digger is at the bottom of the hole. This means that as soon as he reaches the groundwater level, he can only dig about one meter deeper, since digging while holding one's breath under water isn't very practical.
Why is that an issue? Well, I just realized how long this explanation could turn out to be. Maybe it'd be worth it to make some drawings...
Anyway, the 'short' version: different layers of earth have different properties, and allow water to flow through them at different rates. A sand layer, for example, allows water to flow through it pretty quickly. Clay, however, does not. What that means is that, if there is clay at the level of groundwater in a hand-dug well, it will most likely be possible for a user to pump out all of the water in the bottom of the well. Then he will have to wait until the well recharges by filling up with the water that is seeping through the clay walls of the well. If the well hits a sandy layer though, then water flows quickly through that layer, and can often recharge the well just as fast as a user is able to pull water out of the well. This way the well never 'goes dry'.
Anyway...back to well types. The other sort is a drilled well, where the drillers are above ground, and send a long pipe with a bit on the end of it down the hole. They then manipulate that pipe and bit to drill the hole (this involves the bit chewing up whatever rock or sediment it comes in contact with on its way down, but just as importantly pulling that material up and out of the hole). The major advantage here is that you can drill down well below the level of groundwater until you find one of those sandy layers that allows lots of water to pass through it.
That sounds great, right? Well, there's an issue in that it's really expensive to drill a well. For deep or large-diameter wells, a diesel-powered drilling rig is required. For reference, the hole we want to have drilled for our pump testing is probably going to cost about US$5000. Small farmers can't afford that, so we're working with some partners who have experience in manual well-drilling. Here there is no engine involved; we're taking advantage of the very cheap labor that's so abundant in the developing world to keep the cost of drilling a (smaller and shallower, but still functional) well to less than US$200. So we're helping to train a team here in Zambia, and are hoping to get something similar started in Ethiopia soon.
That ends our technology lesson for today, class. More deep thoughts about the developing world coming soon. :-)
Since I've been such a slacker lately in posting updates, here's a quick rundown of what I've been doing for the past few weeks:
Parting shot...
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