The future of sanitation: 10 years of reinventing the toilet

Growing up in modest circumstances in Côte D’Ivoire, we didn’t have a decent toilet at home. I didn’t even know this was a problem. Only years later, at university, after I talked to friends studying medicine and learned how diseases travel through contamination and exposure to feces, did I realize that the deaths of many in my community, including several of my siblings, should have been prevented by better sanitation.

Sadly, my family is not alone in this tragedy. Nearly 250 years after the invention of the flush toilet, 3.5 billion people—almost half the world’s population—have no choice but to use unsafe sanitation facilities. As a result, half a million children under age 5 perish every year from diseases like typhoid, diarrhea, and cholera. Many more people become sick, resulting in an estimated US$223 billion a year in health costs and lost productivity. Bringing safe, affordable sanitation to the world would vastly improve the quality of life for the billions without it. It would also act as a “super-vaccine” that would effectively end the spread of many deadly diseases, just as it already has in places where flush toilets are the norm.

That’s why, in 2011, the foundation embarked on a challenge to “reinvent the toilet” to transform sanitation as we know it. A reinvented toilet, we hoped, would kill dangerous pathogens, potentially transform waste into something of value for low-resource settings, and require no water, electricity, or traditional emptying to remain sanitary. This technology would have great value for cities and countries in the developing world, where common approaches like pit latrines can pose major public health and environmental risks if they are not safely managed. Given that an average toilet (for households with the means to own a flush toilet) can consume up to 50% of a family’s potable water, new toilets can help reduce the pressure on water demand as cities grow.

Ten years later, we are closer than ever to building a world where safe sanitation services are a basic human right enjoyed by everyone, not just those with money and access to water. Just as the COVID-19 pandemic has underlined the importance of preventing the spread of deadly pathogens, it has shown us that, when innovators, governments, philanthropy, and industry come together with urgency and focus, we can develop life-saving solutions to global health crises. The challenge now in both cases is working together to ensure that everyone benefits equally.

A problem of resources

It was at university, after committing to environmental engineering, that I first discovered the lack of sanitation in my community was a more intractable problem than I had imagined. Conventional sanitation processes are just not applicable in the many places where people still use well water and there is no money for high capital infrastructure. In conventional systems, huge volumes of water are used to move waste around, which is why sewage treatment plants are often built on or near bodies of water where treated wastewater can be discharged. But for billions of people around the world, this is literally flushing money down the toilet. Extensive sewage infrastructure is a luxury that remains out of reach, particularly as water grows scarcer in the years to come for many communities in the face of climate change and growing populations.

I realized that if those sanitation solutions would not work for billions of people, especially those living in poverty, we would need to invent something new—some way to re-create the same services in a local, decentralized, more affordable, and less resource-intensive way. As it turned out, the Gates Foundation was thinking along the same lines. They invited me to join them and, after meeting with Bill and touring the Seattle campus, I jumped at the chance to get involved in completely rethinking how toilets could work.

The first 10 years

Over the last decade, the foundation has invested more than US$200 million to support early-stage R&D into reinventing the toilet and other pathbreaking sanitation solutions, and I have been consistently impressed by the creativity and ingenuity of the innovators I’ve met who are working on these issues.

At the first Reinvent the Toilet Fair in Seattle in 2012, participants from 29 countries showed off a variety of inspired designs, from a solar-powered toilet that generated hydrogen and electricity to others that turned human waste into charcoal or fuel gas. In 2015, Bill caused a stir—and put his mouth where his money is—by drinking clean water produced from feces by the Janicki Omni Processor, a remarkable fecal sludge management machine that converts waste into water and electricity. The 2018 Reinvented Toilet Expo in Beijing saw a number of exciting product announcements and funding commitments, including an additional US$200 million pledge by our foundation to support continued research and bolster market development for reinvented toilets. Progress has led to more progress and has energized both our team and a growing number of partners from all sectors of society—industry, governments, development banks, academics, nongovernmental organizations, and communities willing to host initial trials.

Today, over 25 of the breakthrough waste-processing core technologies that make up a reinvented toilet, all developed in the past decade, are being licensed to more than two dozen companies for production, testing, and commercialization. Among them are reinvented toilet designs by the Swiss engineering firm Helbling and the Nano Membrane toilet developed at Cranfield University. The Omni Processor has been tested in the field in Senegal, China, and India, and there should be at least six similar systems operating in these countries by the end of the year. Pilots for reinvented toilets are also underway in South Africa and soon in China to test and refine their service and business models. International standards for non-sewered sanitation systems have been developed to assess product conformity and support countries’ efforts to complement their conventional sanitation that will expand a significant new global industry and that complements the conventional sanitation and wastewater sectors.

Building the non-sewered sanitation industry

The commercialization of new technologies takes time, however: There are more challenges to overcome before reinvented sanitation solutions can protect the health and well-being of billions around the world, at scale. For example, while the core processes and technologies have been developed, they are still too expensive for broad deployment in the low-income communities our foundation serves. We will continue to explore engineering solutions to bring costs down and make these innovations more available and affordable.

As we continue to support reinvented toilets, we also want to help facilitate the complex process of creating a market for them. Part of this work is encouraging governments to adopt policies and regulations that lower barriers to market entry and attract industries and innovators. But ultimately, getting new sanitation products into communities will require the leadership of private companies that are excited about building new businesses in the sanitation sector. From manufacturing to distribution and supply chains to service providers, there are many fertile opportunities in this emerging industry for companies who get involved as early adopters.

After a decade of hard work, experimentation, and exciting partnerships with scientists and innovators, we have made extraordinary progress on reinventing the toilet. Now, more collaboration and commercialization are needed to unleash the full potential of 21st century sanitation.