In honor of World Toilet Day–a day to remember that about 1 in 3 people still lack access to a toilet and nearly 1 billion people defecate in the open–we bring to you one of the most interesting toilet project we’ve seen in awhile.
It’s made of worms.
Don’t get squeamish, they are like the worms that might compost in your backyard. Except “Tiger Worms” (named for their stripes) are kind of like the superheroes of composting worms in that they can survive all kinds of conditions and like to eat a lot of poop, quickly and efficiently. They also can be found on every continent, except Antarctica (presumably there’s not much need for toilets there).
The Tiger Toilet was incubated at Sanitation Ventures, a project run by the London School of Hygiene & Tropical Medicine and funded by the Bill and Melinda Gates Foundation, with an initial prototype run at the Centre for Alternative Technology in Wales, U.K. It’s now being field tested in Liberia, Senegal, Ethiopia, and Ghana by the charity Oxfam International.
For Oxfam, the composting toilets solves a few problems in poor urban areas where piped sewage systems don’t exist and many people use pit latrines or septic systems, says Oxfam America sanitation expert Daniela Giardina. Contents of pit latrines often don’t decompose fast enough, and they fill up and smell foul (and are often abandoned). Meanwhile, septic systems are expensive, and require too much space and maintenance for slum areas. In both, “desludging” can be a hygienic and safety risk.
The flushable Tiger Toilet, by contrast, is compact, easier to maintain, and more hygienic. It uses worms to speed up the decomposition process in a digester so the “solid accumulation rate” drops by 70 to 80% (as does the smell of the toilet and pathogens in them). Every few months the compost needs to be emptied, but it’s safer and easier to do from its own compartment. The liquid part ends up much higher quality–it can be emptied into the ground or collected for re-use in agriculture or gardening.
Importantly: “It looks like a normal toilet,” says Giardina.
In the Senegal trial, also with funding from Bill and Melinda Gates, Oxfam has installed 10 toilets where 100s of people have access, with 12 local masons trained to carry out construction. So far it’s been a success: people aren’t grossed out by the idea of worms, diarrheal disease in young children is down, and households appreciate the cleaner, lower maintenance.
Additional studies are still needed to determine the optimal number of worms and other operating parameters. And scaling up will require a sustainable business model for families to install and maintain the toilet, Right now, Oxfam is experimenting with a few alternatives, such as bundling a Tiger Toilet purchase with medical care or cell phone minutes.
“When we talk about technology, we need to think a lot more about about the local culture and conditions, otherwise it will just be abandoned,” says Giardina.