In early January, a video clip featuring Bill Gates started making the rounds on the Internet. But he wasn't delivering one of his inspiring speeches about vaccines or getting drenched in ice water to raise awareness about ALS. He was just drinking a glass of water.

Sounds boring, right? The catch: five minutes before Gates took his first sip, that water had been human waste pumped in from a local sewage facility. That’s right: Bill Gates drank poop water to entertain an audience on the Internet.

Well, sort of. Gates was using the apparent publicity stunt to unveil the OmniProcessor—a low-cost waste treatment plant that combines a steam power plant, an incinerator, and a water filtration system into a machine capable of converting 14 tons of sewage into potable water and electricity each day. I’ve tried the water myself; not only is it drinkable, it’s actually indistinguishable from tap water or bottled water.

The contraption, about the size of two school buses placed side by side, was engineered from scratch by a small, family-run company called Janicki Bioenergy; its two-year development was funded by The Gates Foundation as part of its Reinvent the Toilet Challenge.

When it was first revealed to the world, the OmniProcessor sat in an open lot in small-town Washington behind other Janicki buildings where workers built machine parts for aerospace, marine, space, and transportation operations. But once most of the kinks were worked out of the prototype—Gates personally inspected the machine late last year—the Janicki team wanted to see how the OmniProcessor worked for real. They took the machine apart and in February traveled to Dakar, Senegal, to rebuild the high-tech waste plant in the city to see if it could live up to its promise. By May, the OmniProcessor was up and running—and it turns out, as usual, that the real world isn't as simple.

Garbage In, Water Out

So far, Gates says, the Janicki is working “as predicted,” though that doesn’t necessarily mean the test is going without a hitch.

"The real world introduces lots of variables," Gates writes in a blog post today. “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.”

Gates says the OmniProcessor team is thinking about how to tweak the OmniProcessor’s design and working out a business plan.

“The next version of the machine will burn most types of garbage in addition to human waste, and it will be easier to maintain,” Gates says. The Janicki team is looking to sell the first $1.5 million OmniProcessor unit to a Sengalese city and is in talks to sell other units to potential buyers in wealthier countries, too.

It’s tempting, Gates says, to focus on the flashier part of the OmniProcessor. Poop water that’s actually drinkable?!? But ultimately, the goal isn’t for the OmniProcessor to produce water, according to Gates. It’s to dramatically improve sanitation for cities in poor countries.

Affordable Sanitation

Today, at least 2 billion people still use toilet facilities that aren’t properly drained, and disease caused by poor sanitation kills 700,000 children a year. Rich-world solutions don’t work in developing countries, either—the infrastructure is too expensive. The whole point of the OmniProcessor, Gates says, is to make sanitation affordable for low-income communities.

In the city of Dakar alone, 1.2 million people aren't connected to a sewage line. Instead, they have their own pits where people dump fecal waste. To deal with the waste, members of the community often empty the pits manually, filling buckets by hand and transferring sludge to holes in the ground that they've dug themselves. It's a truly dangerous business—because of the rapid spread of pathogens, these people risk getting seriously ill from the work.

A better way to deal with the waste is to mechanically transfer fecal sludge via trucks and tubes to treatment plants. In Dakar, those plants have now been partially replaced by the OmniProcessor. According to Mbaye Mbéguéré, program coordinator at the National Institute of Sanitation, about one-third of the sludge in Dakar is now processed by these machines, turning human waste not only into drinkable water but producing electricity and ash for use in activities like construction.

Clean Tech

That's not an insignificant accomplishment for the OmniProcessor. The hope is that other entrepreneurs in Africa, seeing the machine's success in Dakar—that is, not just proving feasibility, but actually succeeding as a business model—will push them to invest in sanitation, as well.

“Why hasn’t anyone built one before now?” Gates asks. “Because the people who understood the technology weren’t getting sick or dying from contaminated water, and they didn’t know anyone who was. Nor was it clear how they could make a profit by working on the problem.”

Whether or not the OmniProcessor will see real success, the Gates Foundation’s effort to move sanitation research forward—not exactly the sexiest science there is—is laudable. As Mark van Loosdrecht, a professor of environmental biotechnology at the Delft University of Technology in the Netherlands, pointed out in January, having support from a philanthropic organization—especially one with pockets as deep as the Gates Foundation—is an advantage for researchers and developers of sanitation tech. “They don’t need to worry about the support,” he said. “I like the long-term vision instead of the usual program with short-term gains.”