David Auerbach

Co-founder, Sanergy

IT STARTED AS HOMEWORK. For a business development course at the Massachusetts Institute of Technology, David Auerbach was asked to solve a problem that affects a billion people. He, along with a group of classmates, went even further.

“Two and a half billion people in the developing world lack access to a good toilet,” Auerbach says. “And the impact is closer to 4.2 billion if you measure where the waste actually goes.”

The toilets most of the developed world take for granted are rare commodities in many poorer countries, especially within informal settlements. As a result, people are forced to use pit latrines or the so-called “flying toilet” — a plastic bag that sends waste to wherever it’s thrown.

And the negative impacts range from environmental degradation to disease and public safety risks.

Auerbach and his classmates saw an opportunity. Since graduating in 2011, the five co-founders have built a business around providing hygienic sanitation facilities to slum dwellers.

Sanergy has sold more than 400 toilet units to entrepreneurs in the Mukuru settlement of Nairobi, Kenya. (Sanergy photo)

Their company, Sanergy, works with local community members in Mukuru, an informal settlement in Nairobi’s southeast corner. More than half a million people are crammed into just three square kilometers, and sewers are non-existent.

To fill this void, Sanergy makes and sells a standalone waterless toilet facility to community members, who then charge users a nominal fee of about 6 cents per use. Locals collect waste cartridges daily and deliver them to a centralized processing center where it’s turned into organic fertilizer and sold to local farmers. Auerbach calls this the “sanitation value chain”: providing a good toilet facility, collecting the waste, and ensuring that it gets treated properly.

“We’ve always been interested in market-based approaches to tackling social issues,” Auerbach says. “And I think what we hit on is that eventually this demonstration of value from waste exists in many parts of the world. But it’s not something that’s talked about.”

Sanergy sells individual toilet units for $600 — or two for $1,100 — and provides a free year of waste collection. So far they’ve sold 405 facilities to 211 entrepreneurs in Mukuru. “These are people who are really transforming their communities,” he says.

In total, these facilities see an average of 16,000 users per day.

As those numbers suggest, the need for formal sewage infrastructure is obvious. But the cost of building one is massive. Even the community block toilets that sometimes exist in informal settlements are costly — often upwards of $25,000 — and rely on large plots of land on a community’s fringe. Sanergy’s individual units bring the financial barrier way down and fit more easily into dense urban fabric.

Auerbach says Sanergy is hoping to expand its reach in Nairobi, potentially working with municipalities and governments to put facilities in schools and other neighborhoods, providing a medium-term solution for a sewer system that may never get built.

Locals collect waste cartridges daily so that it can be turned into organic fertilizer.  (Sanergy photo)

But it’s not cheap. Sanergy was able to get started thanks to winnings from a few business plan competitions and social impact investors, foundations, and the U. S. government.

“We’re developing new approaches to working within municipalities that are highly risky and very much in a research-and-development stage,” he says. “And yet these have the greatest potential for public good. So we turn to foundations focused on maximizing public good for their support.”

After two and a half years in Mukuru, there’s still plenty of work to do. But Auerbach also wants the Sanergy idea to spread. He’s hoping to develop a model that’s widely transferable, through Kenya, Africa, and even southeast Asia. With urban populations growing and billions already lacking proper facilities, the need is staggering.

“The way that we think about it,” he says, “this is just the start.”

Nate Berg

This story is part of a series of Citiscope profiles on urban innovators from Montréal to New Delhi who are improving lives, designs and fortunes in their cities. All are speaking at the New Cities Foundation’s 2014 New Cities Summit in Dallas from June 17-19, attended by urban leaders from around the world. Read the profiles here. And see David’s presentation in the video below.

Meet the Innovators

New York City
New Delhi

More from Citiscope

Latest Commentary

Back to top

Our Partners

Citiscope spurs innovation to help cities work better for all of their people through the power of independent journalism. Read more ›

Get Citiscope’s email newsletter on local solutions to global goals.

Browse by City