Waste Not: In Ghana, Fecal Sludge Could Be Black Gold

Accra, Ghana, is a tropical capital on the Gulf of Guinea, but almost no one swims in the ocean here. If you are not turned off by the mounds of trash the ocean continuously heaves onto the beach, the water’s unnatural brownish color hints something is awry. The city’s open sewers empty straight into the ocean. And then, of course, there is Lavender Hill.

Every day, just past a lighthouse on Accra’s western edge, trucks dump more than 250,000 gallons of human feces directly onto the beach and into the ocean at Lavender Hill.

“That's over 100 trucks dumping continuously, day in and day out, where the sludge is channeled down the beach and into the sea,” says Ashley Murray, the 32-year old founder and CEO of Waste Enterprisers, a Ghana-based business with the mission to improve urban sanitation.

In the slums of Nima and Jamestown, owners of toilet blocks have to pay dumping companies to empty their pay latrines, Murray says. When they can’t pay trucks to come empty the waste, the toilets shut down, and people have to find other places to defecate. Ride your bike or walk along Accra’s beach road, and you can’t escape the smell of shit.

In sub-Saharan Africa, Murray says, such practices are par for the course. More 85 percent of the human waste generated in Ghana and in sub-Saharan Africa is dumped into the environment without any treatment, according to the World Water Assessment Program. This results in an ongoing public health disaster: The World Health Organization reports that diarrheal disease amounts to an estimated 4.1 percent of the total global disease burden and is responsible for the deaths of 1.8 million people every year.

Why not just build sewage treatment plants? International funders have tried that before. “If you look around Ghana and pretty much anywhere in sub-Saharan Africa, you will find broken down treatment plants,” Murray says. There is even one by Lavender Hill. The plant was built with international funding, but when the funders left, the plant soon sputtered to a halt. It now sits idle.

Building sewage treatment plants, she says, is “based on a Western approach to sanitation.” One assumes the government will bill households, that households will pay those bills, and that collected fees will cover the cost of operating the plant. In reality, governments have been slow and inefficient in setting up billing systems. Even when they do, paying for sanitation simply isn’t a priority for folks living on less than $2 a day.

Still, households and toilet block owners currently pay the truck companies as much as $80 pick up their waste and then dump it at Lavender Hill. And there is no monetary incentive to improve the system.

Instead of charging people to have their septic tanks and pit latrines emptied, Murray wants to pay them for the waste—or at least take it for free—then process or convert it into a product that will sell. She wants to reinvest some of the profits back into the sanitation sector. “We want to show that we can do good and be a profitable company,” Murray says.

So far, Waste Enterprisers, along with research and funding partners including Columbia University, the Gates Foundation, and the Swiss Federal Institute of Aquatic Science and Technology, has numerous plans to process human feces. They want to turn our crap into an industrial fuel used in cement kilns, turn stagnant sewage treatment ponds into profitable fish farms, and finally, build the world’s first ever fecal-sludge-to-biodiesel plant, which will be funded by the Bill and Melinda Gates Foundation.

“We’re really on the cutting edge of waste reuse, particularly on this continent. There is still this status quo syndrome of ‘waste is something to be gotten rid of.’ Only now in the U.S. and Europe, reusing waste is becoming more mainstream. I think in the next decade or so it will become the thing to do,” Murray says.

Right now, researchers at Columbia's School of Engineering and Applied Sciences and Kwame Nkrumah University of Science and Technology are developing the technology to turn fecal sludge into biodiesel.

Fecal sludge, by the way, is the industry term for the stuff you find inside latrines. It’s more concentrated than the watery sewage we have in the industrialized world, and according to Kartik Chandran, associate professor of earth and environmental engineering at Columbia's engineering school, “much, much better for fuel.”

It is hard not to find Waste Enterprisers’ concept a bit, well, amusing. Murray, maybe a bit ambitiously, “would love for us to see fecal sludge as a raw material.” She speaks passionately, and seriously, about the “calorific value of fecal sludge” and how to “develop a sewage sludge management strategy.”

But break into a smile, and she gets it. She is used to hearing people make friendly cracks about her “poop business,” and she says it doesn’t bother her. “We joke about it too!” she says good-naturedly. But, with ten years of experience in the sanitation sector, any discomfort the Massachusetts native ever felt talking about human feces wore off a long time ago.

It was only a few years ago that Murray decided business was the best way to improve urban sanitation. For years, Murray’s interest in reusing waste was “purely environmental.” But in 2008, while conducting research for her doctoral dissertation in China, she had a realization. She had been approaching local government officials trying to get them to adopt reuse programs, but the officials were not persuaded by her environmental arguments. They treated it like “icing on the cake,” she says.

“I realized the environmental argument was never going to get me anywhere,” she laughs. “I starting thinking, OK, what’s a more compelling argument for reusing?” she says. “And I started thinking about the economics.”

She thought about how those in the field of sanitation had been calling waste a “resource” for years, but no one was really treating it like one. “If you are calling it a resource, if it’s a resource, then by definition it has a financial value, so why aren’t we trying to harness that for the benefit of the sanitation sector?” she wondered.

Soon the idea for Waste Enterprisers came together, and since then, Murray has been wondering if—through business—she might be able to bring about a “sanitation revolution” in Africa. “Even if you did this straight as a for-profit business, it’s still going to provide a lot of social value, but [for us] it’s how are you really going to maximize [the social value],” Waste Enterprisers COO Timothy Wade says.

Wade, who holds an MBA with a focus on social enterprise, has calculated that the projects they can make an “attractive profit” and then add carbon credits to that. “Then you have a pretty attractive business model,” he says. “And you’re getting rid of, literally, all of the shit.”

But even if they get the technology right, will the biodiesel be cheap enough to compete with diesel? Chandran says that while company executives are still figuring out the numbers, they are estimating the fuel will cost about $3.50 a gallon, slightly lower than the price of diesel in Ghana.

And Murray is not putting all her eggs in one basket, either. She thinks one of the group's other businesses, an industrial fuel, will be commercialized before the biodiesel. “The calorific value of dried fecal sludge ranges from being the equivalent to wood, to being equivalent to coal,” Murray says. In Japan, China, and parts of Europe, wastewater treatment plants are already sending that watery sewage sludge to cement kilns, where it is burned as a fuel. “So I’ve been really eager to try to apply that management solution to fecal sludge,” she says.

And Waste Enterprisers already has a small revenue stream from its third business: fish farms. The company is taking poorly performing waste stabilization ponds, and creating incentives to maintain them by making money off of the ponds through raising and selling catfish. By the time the water gets to the last pond, where the fish live, the water is treated enough to raise fish, Wade says.

But are people willing to eat fish that have been raised on human feces, even if the waste has been semi-treated? And when you get down to it, will consumers be receptive to any product made out of human feces?

Because the diesel and fuel are meant for engines and industrial uses, Murray says, human contact with it is limited. And once produced, it will be indistinguishable from other biodiesel. She acknowledges there may be more social barriers to using the waste for raising fish. Studies show there is much greater social resistance to reusing human waste in agriculture than in industry, she says.

But if the fish farms don’t gain traction, the folks at Waste Enterprisers aren’t worried. “We have these three businesses and we’re exploring all three as an option,” Wade says. “We’re not a company that does one thing.”

Photo courtesy of Ashley Murray