A combination toilet/waste treatment system created for use in developing countries with no electricity, running water, or sewers eventually could replace septic systems in American homes on the Atlantic shoreline. The experimental bathroom, designed by Caltech engineers and funded by the Bill & Melinda Gates Foundation, runs on solar power to flush, disinfect, and recycle human waste into water for the toilet, urinal, sink, and “squat pan” that are part of the side-by-side restroom and treatment unit.

Two prototype units started operating in New Delhi in January. Caltech has plans to test additional units in India and possibly in Thailand, Cambodia, Vietnam, and China.

Kohler Co. supplied toilets, sinks, and other fixtures, along with advice on designing the blue-tiled bathrooms so they would be appealing to and comfortable for users.
The goal of the project, which won a grant from the Gates Foundation, is to bring flush toilets to parts of the world without the running water or sewer systems that developed countries rely on to use theirs. Caltech’s Michael Hoffmann, the project’s principal investigator and a professor of environmental science and engineering, estimates that 2.5 billion-plus people around the world do not have access to flush toilets.

The foundation’s overall goal, he notes, is to prevent diseases caused by contact with human waste in areas where people who have no access to indoor plumbing relieve themselves outdoors and in rivers.

The first units, which Caltech built into 20-foot shipping containers, cost $50,000 each and are expected to serve as public restrooms rather than as residential bathrooms. Hoffman estimates the price could drop to less than $1,500 in developing areas, where buyers likely would charge people a nominal fee to use them and hire others to maintain them—a practice that could help local economies.
The unit also would cost far less than the prototypes to install in a home, Hoffmann says, because it wouldn’t need to be built into a container or come with technology that transmits data back to the Caltech campus. He already has heard from some sustainable housing advocates in the U.S. and from the EPA, which is looking for alternatives to conventional septic tanks on Cape Cod. He predicts the technology could show up in Cape Cod homes in as little as three years.

Rob Zimmerman, senior channel manager-sustainability for Kohler, agrees that the technology will find its way into U.S. homes. “Whether it’s in two years, five years, or 25 years, at some point, water is going to be a constraint on home building and commercial building, and it’s going to have to be independent of that scarcity,” he says, noting the bathroom will look much different in the home than it does in a shipping container in India.

For now, however, “It’s about health. It’s about people’s lives,” Zimmerman says. “It’s an important humanitarian project, and an important project for [the bathroom products] industry.