April 16, 2015
Tate Rogers (in rear, with white mask) works with a local pit-emptying team in South Africa to field test the Excrevator. Photo courtesy of Tate Rogers.
In 2011, an engineering student came up with an idea to help people in the developing world deal with raw sewage. His goal was to use technology to help save lives by limiting people’s exposure to the pathogens in human waste. Four years and several countries later, he’s still working on it – and the technology is beginning to come into focus.
Here’s the basic problem: in many parts of the developing world, people don’t use toilets. Instead, they use pit latrines, which quickly fill up with raw sewage and have to be emptied by hand. Emptying those pit latrines means coming into contact with human waste – and whoever has to empty those pits runs the risk of contracting a disease.
NC State engineering professor Bob Borden presented an undergraduate class with this problem in 2011, and a student named Tate Rogers had a possible solution. Rogers proposed the development of a hand-held tool that used a gasoline-powered auger (like a giant corkscrew) to pump the waste out of the pits into portable containers. The twisting of the auger would act like an Archimedes’ screw to move the waste.