Nearly 250 years after the invention of the flush toilet, 3.6 billion people across the world still lack access to safe sanitation facilities, making it much more likely that infectious diseases will spread. Modern sanitation systems with flush toilets, sewers, and sewage treatment plants are often unaffordable in many low-income countries and regions because they require significant land, energy, and water and are costly to build, operate, and maintain.
To address this challenge, we support scientists and engineers around the world who are inventing non-sewered sanitation technologies that can safely and effectively manage human waste without relying on the electrical grid, water supplies, or sewers. We also work with public and private partners to commercialize the most promising and viable reinvented toilet technologies.
With our grants and technical support, two Chinese companies have each developed a reinvented toilet that boasts many technical advantages over conventional toilets. One is a recycled-water-based toilet that uses aerobic-anaerobic microbiological and biofilm treatments, and the other is an eco-friendly toilet that combines microbiological treatment and electrochemical technology. Both feature modular installation, water recycling, and the safe processing of human waste in a single toilet. They are thus particularly suitable for regions without sewers or with little access to water or electricity.
To assess and validate the potential of these two reinvented toilets, we work with China’s Academy of Agricultural Planning and Engineering and the Ministry of Agriculture and Rural Affairs on pilot and demonstration projects in a variety of geographic, climatic, and economic conditions. With the University of Science and Technology Beijing, we have also conducted comprehensive monitoring, testing, and evaluation of these new toilets using ISO30500, the international product standard for non-sewered sanitation systems.
These efforts aim to determine the technical adaptability, resource use, and carbon emission reduction effects under different use scenarios for each toilet system, measured across dimensions such as construction, operation and maintenance, and management. For example, because both toilets are prefabricated in a factory and feature standardized installation, preliminary test results show that they can shorten onsite construction time to 1 to 3 days. Both reinvented toilets also enable operation and maintenance workers to identify and solve problems quickly (and often without human input) thanks to the combination of smart online monitoring with on-site maintenance. And the water generated after feces are processed meets ISO30500 standards, which means that it can be reused and that the spread of fecal-oral infectious diseases is prevented and controlled at the source.
Building on the promising results of these pilot and demonstration projects, we are exploring the feasibility of scalable solutions and business models that can accelerate the mass adoption of these reinvented toilets around the world.
