Creating sustainable waste solutions for the developing world

David Auerbach
Wednesday, October 10, 2018

The Program on Economics, Politics, and Economics hosted David Auerbach, Yale ‘03 alum and co-founder of Sanergy, for the annual Litowitz Lecture on Septmber 27. Sanergy is a company dedicated to providing safe and sustainable sanitation solutions in underdeveloped cities. He previously worked at Endeavor, an organization focused on high-impact entrepreneurship in emerging markets, and was a Yale-China Teaching Fellow.

Auerbach began by describing the sanitation problems that arise from urbanization, noting that 4.5 billion people currently live in communities where waste is never treated, which has both health and economic implications. He attributed much of the issue to slum residents not being treated as customers for adequate sanitation service delivery. As such, sanitation options available to them are often “undignified, dirty, and dangerous.”

In Auerbach’s experience, poor regulation of sanitation and waste disposal is coupled with the widely held belief that sewers are the only solution. However, sewers are “expensive and impractical.” Auerbach acknowledged that his push to move away from using sewers is “provocative,” but he insisted “it is something I encourage us all to think about as water becomes scarcer and cities grow at such rapid rates.”

He then described Sanergy’s work in Nairobi, Kenya. Through a sustainable model where 100% of waste is treated, Sanergy’s bright blue Fresh Life Toilets are contracted to community members who keep them clean and accessible. By establishing a reseller model, where farmers sell the product to their neighbors, Sanergy is able to increase the use and accessibility of toilets. Even though Sanergy began in 2011, it now has about 76,000 users per day through a network of nearly 2,000 Fresh Life Toilets.

Auerbach noted that Sanergy has also contributed to the “formalization” of waste collectors. Through employee benefits bestowed upon waste collectors, such as health insurance, regular inoculations and uniforms, waste collecting “becomes a dignified job.”

He then described how the waste from Fresh Life Toilets makes its way to the waste processing plant about thirty kilometers from the city, where it is turned into organic fertilizer and animal feed. According to Auerbach, the organic fertilizer produced has helped farmers increase crop yield by 30%. Unlike synthetic fertilizers that eventually “deplete the soil of its nutrients” and “serve the plant,” organic fertilizers “serve the soil” by strengthening the soil structure, enabling it to retain nutrients and water. He next discussed how waste is turned into animal feed: by growing and harvesting black soldier flies – which produce an animal feed that is 50% protein. Unlike traditional animal feed that farm animals consume which is derived from fish, the animal feed made from black soldier flies is “natural to their diet.”

Auerbach noted that with Sanergy’s growing success, “we are now able to work with the government as a trusted partner.” In the future, he hopes to “build a partnership with the government where they are the ones that take this on.”

By addressing the sanitation problem in slums, he hopes to “think critically and act practically, developing sanitation systems that work to serve everyone, particularly residents of urban informal settlements.” However, the overwhelming focus on sewers as the solution to sanitation has been an impediment to the adoption of a new way of thinking.

Though the government often sees the Sanergy model as a “short- to medium- term” solution, Auerbach believes that it could eventually prove a viable and sustainable alternative to existing sanitation systems.

While he was on campus, Auerbach met with me before his lecture to talk more in depth about his work and the Sanergy Internships for students which are administered by the MacMillan Center. Auerbach said he “set up the fellowship about 4 years ago as a way to give students at Yale a great opportunity to undertake meaningful work at a dynamic social enterprise in the heart of Nairobi. Students have done a range of different projects depending on their skill sets and interests. We’ve had an engineer undertake work on improving the design of our toilet products for residents of urban slums and a MBA student who helped us think through talent strategy. The students’ projects have all had important deliverables, but often the most rewarding part of the experience is the chance to work with our team in Nairobi and transfer skills and knowledge developed at Yale to our teammates who benefit tremendously in the short and long terms.”

He also discussed fundraising challenges. The “increasing interest in the sanitation sector” has led to new funding opportunities, especially from European and North American governments. He noted that a big shift in interest toward sanitation occurred in 2015, when the UN Sustainable Development Goals prioritized sanitation and waste management.

When asked about why sanitation was not prioritized until recently, he said that “it’s just something people don’t want to talk about. We like to ‘flush and forget’ and we don’t want to think about the waste and face up to the consequences.”


Written by Julia Ding, Yale College Class of 2019.