Poop-Eating Worm

As I turned into another alley in the West Point slum in Monrovia, Liberia, I was hit by the stench of human waste. On this tiny peninsula jutting into the Atlantic, one hundred and twenty thousand people - a population bigger than Ann Arbor's - live without access to safe sanitation. To help remedy the situation, Oxfam is testing the Tiger Worm Toilets, aka the poop-eating worm toilets, with several West Point residents. But judging from the smell, the construction of a toilet wasn't working well enough to keep the community healthy.

After decades of civil war, Liberia is one of the poorest, least developed countries in the world. With great poverty comes rapid urbanization, including informal urban settlements, where unhygienic conditions pose serous health risks. The Tiger Worm Toilet treats both liquid and solid waste using composting worms that digest the waste, reducing both the pathogen load and the frequency with which the toilet needs to be emptied. The owners don't have to pay to maintain their toilets; once a month a locally trained technician comes, pulls apart the slabs, checks to make sure the worms are still happy, and moves on. This technology is what the water and sanitation world is looking for: a low-cost, sustainable sanitation solution with a small enough footprint to work in urban slums.

However, in the West Point slum, where eight people or more often squeeze into one-room shacks, the Tiger Worm Toilet's footprint was still too big. In West Point, the alleyways are very narrow, and neither they nor the houses had enough open room to fit a 1-meter by 1-meter Tiger Worm Toilet. Residents without proper sanitation are forced to go to the bathroom in the open or use "flying" toilets.

Faced with this problem, the team and I started brainstorming. What if we made the compost waste tank half a meter by 2 meters to fit in the slum's alleyways? But then we realized that this wouldn't work because the physics of the toilet required a one-meter square tank. Well then, what if we put half the latrine under the raised toilet in the house, and the other half outside the house, so that only half a meter would stick outside in the alley?

Soon enough, I found myself in the car with the engineers Andy Bastable, Oxfam's Public Health Engineering Coordinator, and David Watako, Oxfam's Head of Water and Sanitation for Liberia, drawing diagrams on scraps of paper: we were going to tweak this Tiger Worm Toilet to fit into the West Point alleys and homes.

Did our solution work? I can't wait to find out. We are problem solving in real time: in 2 months David's experiments on the ground will tell us if our idea fixed the problem. It's thrilling to think that not only are we changing lives in one Liberian community, but that, if it works, we can scale up this solution to bring safe sanitation to the world's most congested slums.

Here's how you can learn more about healthier communities across the globe: http://www.oxfam.org.uk/