Improving access to safe sanitation for the world’s urban poor, one container-based toilet at a time

Nearly a billion people worldwide live without adequate sanitation.

In Haiti alone, up to two-thirds of the country’s 5.3 million urban residents live in slums where going to the bathroom often means using a crowded public toilet or using no toilet at all. Unsurprisingly, diseases like cholera are common when waste moves around the community, particularly in areas prone to flooding.

As urbanization continues, urban slums worldwide continue to grow. Without adequate sewage systems, water contaminated with harmful pathogens from human waste is an urgent yet largely unaddressed problem. In Haiti, a country of just over 9 million people, 10 children die every single day from water-borne illnesses.

In 2011, a Stanford team led by Jenna Davis, Associate Professor of Civil and Environmental Engineering, partnered with the Haiti-based NGO  Sustainable Organic Integrated Livelihoods (SOIL) to tackle this global problem. Stanford received a grant from the Bill & Melinda Gates Foundation's "Reinvent the Toilet" program for this work.

Together, Stanford and SOIL developed a household container-based sanitation (CBS) solution for Haiti – a portable, self-contained toilet that collects waste which is then removed by trained personnel.

A simple solution to a difficult problem

Davis, a faculty affiliate at the Stanford Center on Global Poverty and Development, says that there are several things that urban households most at risk from lack of sanitation services worldwide often have in common. The settlements where Stanford and SOIL worked in Cap Haitien, Haiti, shared these features: residents were “renters in an unregulated low-lying area prone to flooding,” Davis said.

It was important for the research team to form strong relationships with in-country partners for this project. Stanford alumna Sasha Kramer ’06 was already working on sanitation issues in Haiti as the cofounder and executive director of SOIL, which had already introduced community level, container-based toilets to several communities in Haiti. Along with SOIL, Davis's team wanted to focus on sanitation solutions that could address common disadvantages of public toilets, including safety concerns for women accessing them late at night and dangers associated with water contamination when flooding occurs.

Davis said the team focused on an in-home solution to overcome these disadvantages. Other requirements were the toilet model had to be portable, convenient, aesthetically appealing, affordable, and reliable. "It was also important that an in-country partner like SOIL had the interest and ability to take ownership of the social enterprise after the researchers left," she added.

Under Davis’s guidance, civil and environmental engineering PhD students Kory Russel and Sebastien Tilmans developed the container-based sanitation (CBS) toilets as part of an initiative called re.source, partially funded by the Stanford Institute for Innovation in Developing Economies. The initiative used the findings from their research to advise SOIL, which was servicing over 4500 people by the end of 2016 after starting a second service in Haiti’s capital, Port-au-Prince.

When developing the toilet, the research team used user-centric design principles, meaning they solicited the potential users for insight on what was needed for a successful design. They found out that the product absolutely had to have a traditional toilet seat, it had to be multi-tasking (for example, it could be covered and used as storage space when not in use), and it had to be mobile. A private toilet, the team discovered, was seen as a symbol of wealth and cleanliness.

A container-based sanitation system is simple – it is made up of a box with a removable container topped with a traditional toilet seat. Dry cover material made out of peanut shells and sugarcane pulp isolates the waste and manages odor and insects. Households are leased the toilet, which reduces the often substantial financial barrier of having to pay for construction of a traditional toilet. Container-based toilets are also more resilient than latrines or septic tanks to flooding, and they are not dependent on municipal infrastructure such as trunk sewers.

There are a few limitations associated with the CBS system that prevent truly widespread implementation. Among these is a lack of interest from governments to invest time and money in infrastructure for unregulated communities. This is why in all areas where CBS toilets have been introduced, the efforts have been organized by NGOs. Additionally, many people living in urban slums simply lack the space in their home for a toilet, no matter how small and compact it may be. In fact, in the initial Cap Haitien trial, close to a third of the households originally selected for the pilot had to be eliminated due to space limitations in their homes.

A sanitation movement

In the initial trial, one hundred and eighteen households were randomly selected to receive toilets and a twice-weekly collection service, at no charge. “The most compelling thing for me,” Davis said, was that “at the end of the free trial, 71 percent of the households converted to paying customers.” The cost? $5 per month.

“It's become a movement now,” Davis said of container-based sanitation. “There's a coalition,” she said, referring to the Container Based Sanitation Alliance, comprised of practitioners developing CBS services around the world. These include SOIL in Haiti, Clean Team in Ghana, Sanivation and Sanergy in Kenya, Sanitation First in India, and x-runner in Peru, among others. These organizations collaborate with larger partners like Oxfam to produce, distribute, and advocate for the use of CBS toilets for some of the most vulnerable people worldwide who lack sanitation access.

Besides the obvious personal benefits like safety and cleanliness, CBS systems also offer wider benefits for all of the communities where they are implemented. In part, this is because the toilets must be serviced by trained technicians, meaning added jobs in the community. Furthermore, the waste is transformed into agricultural-grade compost that is useful for reforestation efforts. Though Haiti was once an important agricultural producer, deforestation and urbanization have stripped the soil of nutrients so much that it cannot produce enough food to feed its population.

CBS systems are revolutionizing household sanitation, particularly in densely populated urban communities. They demonstrate that sanitation can be dignified, affordable, and sustainable while addressing a global crisis.

Please note that prior to May 2019, the Stanford King Center on Global Development was known as the Stanford Center on Global Poverty and Development.