Translating Sanitation Solutions Across the World

Hungry rodents and bored children aren’t typically obstacles faced when designing a complex system in a laboratory. But once that technology moves from a highly controlled environment to the places it must eventually function, anything is on the table.

Even sore knees and hard water.

These are some of the very real obstacles that engineers from Duke University faced while field testing sanitation systems aimed at making the world a heathier place. As leaders of the Center for Water, Sanitation, Hygiene and Infectious Disease (WaSH-AID), they have spent many years taking technologies developed by dozens of teams from across the world into communities. Funded by the Gates Foundation, WaSH-AID is one of the implementation arms of the foundation’s ambitious “Reinvent the Toilet” challenge.

Through many parallel efforts, the team has learned some hard lessons about what it takes to field test sanitation systems in a wide variety of cultures and environments. With years of experience under their belts and partners from South Africa and Thailand, they recently published a compendium that details their challenges and successes to help others follow in their footsteps.

“There is a huge gap between technology that works in the laboratory and a sanitation system that works where users have uncontrolled access,” said Sonia Grego, associate director of WaSH-AID and an associate research professor of electrical and computer engineering at Duke. “It is imperative to test systems in the field in the early stages of development to figure out what has an actual chance of becoming a solution adopted by the intended users.”

“I’ve had the opportunity to do a lot of international travel in South Africa, Namibia, Botswana, Kenya, Burundi, as well as India,” said Sarah Hennessy, WaSH Lead for the Triangle Environmental Health Initiative, a local Durham company that works closely with Duke on these projects. “And each place I’ve gone, especially in rural regions, I’ve seen the need for water and sanitation, so I know how the lack of these services really impacts human dignity as well as health.”

From the beginning, Duke Center for WASH-AID has been home to multiple projects funded by this Gates Foundation initiative. These grants built up expertise at the university along with a high level of familiarity and trust from the Gates Foundation. Grego in particular had a large amount of prior experience in sanitation field testing, having served as field testing technical lead for two other Gates-funded projects and developed the global field-testing protocols that informed projects in India and South Africa. In 2019, the Gates Foundation awarded Duke $4.5 million to the Center for WaSH-AID to field test and translate the many promising projects into the real world. Five years later, the foundation asked Grego to gather the hard-earned lessons from around the world to create a resource for practitioners and technology developers.

“We’ve been working with sanitation experts from India, South Africa and Thailand; collectively these teams have field tested over 30 prototypes and sanitation technologies,” said Hennessy. “We’ve compiled a compendium of lessons learned on a range of topics, from technical to stakeholder engagement to user behaviors. We really want people to use it as a resource, to learn from our challenges to propel future efforts toward sanitation for all.”

Rodents, Cranes, Children and Knees

Between testing several different systems across multiple continents and very different circumstances, the Center for WaSH-AID team has a lot of wisdom to pass down. They also have a lot of stories to tell.

For example, nobody told them beforehand how important their relationships with local crane operators would be. How else are you going to get shipping container-sized systems where they need to be? Or in Coimbatore, India, where they discovered just how pesky rodents and unwatched children can be.

“The systems were designed to work outdoors, but they were not really ruggedized. So, our engineers had to learn how to protect them from rodents chewing electrical wires,” Grego said. “Also, some of the systems came with bright, colored buttons that turned out were extremely attractive to the children of the community.”

Other lessons learned had more to do with the specific location and culture of the system being tested. For example, in one case, the water being used was so hard that salts accumulated on critical components and caused them to fail within a matter of days. Another found difficulties in convincing users they did not have to bring their own water into the bathroom to flush, which diluted the waste too much. And in another instance, a sanitation system they were testing wasn’t performing the way that it should, and nobody could figure out why.

The group put together a questionnaire to try to get to the bottom of the problem, but bathroom habits are typically extremely private topics that nobody wants to share. Eventually they figured out the trouble, which the technology developers hadn’t foreseen.

The system was based on a simple floor-mounted style that is very common India. When squatting, women’s urine should have been directed to a separate handling process.

“We learned that, for some women, particularly older women, knee pain prevented them from squatting all the way down to use the toilet in the way that it’s most commonly used,” said Mara Shurgot, communications strategist for the Center for WaSH-AID. “That was actually changing how the toilet was working. We all have knee pain at some point in our lives, so it was something that we could all relate to. But it’s not something that had been considered in the development of the toilet.”

“Going to the toilet is a very private act, and it’s really hard to know what’s happening behind closed doors,” echoed Grego. “And yet, by analyzing the waste, we can tell that people’s behaviors and habits and preferences are wildly different across countries, across cultures, across continents, and even within the same country depending on their social status. So, all of this has to come into play when reinventing the toilet.”