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EARLIER THIS YEAR, Bill Gates made headlines for the oddly captivating feat of drinking water that had been raw sewage just five minutes earlier. Poop water, in other words.

But Gates wasn’t taking on an unsanitary dare; he was publicly demonstrating the quality of a Gates-funded machine, the Janicki Omni Processor, that turns sewage into electricity, ash, and drinking water. Developed by Janicki Bioenergy, the system can convert 14 tonnes of sewage into electricity and drinkable water each day.

Now it’s being tested in the real world. Eventually the system could help some of the 2 billion people who lack proper sanitation to remove pathogen-ridden sewage from their communities.

The first test is happening in Dakar, Senegal, where 1.2 million residents don’t have a connection to a sewer line. As an alternative, they often remove sewage from pit latrines in buckets, placing the waste into holes dug in the ground nearby. It’s an ideal breeding ground for sanitation-related diseases including cholera and typhoid fever.

Mechanical emptying, a process in which trucks bring sewage to treatment plants, is better. But until the Omni Processor came along, Dakar didn’t have the technology to get rid of pathogens once sludge arrived at the treatment plants.

Gates writes on his blog that it’s “working as predicted” so far, but there are still kinks to contend with.

He writes: “The machine has to be tested — and unlike a computer program, sanitation machines can’t be tested from a desk in Seattle. The real world introduces lots of variables. For example, you have to find the right personnel to run the machine. You have to work with local and national governments and gauge the public’s reaction.”

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