The Zero-Gallon Flush

Sustainable toilet technology for a waterless world

Photograph via Kohler

The common household toilet hasn’t changed much since the 1800s. Water-based flush toilets work the same now as they did 100 years ago, sucking up water at a rate that makes them impractical in countries with no sewer system or running water supply. The toilet, resource-hungry and inefficient, is outmoded. But with the advent of the biosciences and modern technology, the common household toilet recently received a much-needed upgrade, readying it for a world where water is a precious resource for developing countries.

The Bill & Melinda Gates Foundation, as part of its charitable pursuits, funds research into sustainable toilet technologies for use in the third world. Structured as a contest, thousands of researchers compete to see who comes up with the most effective designs. To meet the strict requirements for success, the toilet must function without water, electricity or a septic system, operate on five cents or less a day and produce no pollution or harmful byproducts.

Taking up the challenge, scientists from all over the world compete, strive and collaborate with their peers, coming up with wild and ultra-efficient variations on the familiar porcelain seat we all know and love; examples include toilets that turn waste into coal and toilets that compost waste into fertilizer. There is even a toilet that uses fly larvae to safely decompose excrement. The top ideas get a green light for full-funding to take the product to market, where entrepreneurs use them to the benefit of society (and to turn a profit).

“We couldn't be happier with the response we've gotten,” Bill Gates said in a USA Today article.

The push for sustainable waste disposal systems grows dramatically each year, driven by humanitarian efforts and economic woes as water becomes more precious. Poor sanitation and the lack of running water in third-world countries are responsible for millions of deaths each year according to UN estimates, creating an interest in using the technology in developed countries for resource-management purposes. American homes with such systems in place save many gallons of potable water a day, water otherwise spent on flushing.

Changes are coming to the humble toilet, changes contrived by the brightest minds in the field. For better or for worse, the world is running low on water, and the toilet, a notorious water hog, is ready for a redesign.

- Bryant Morrow, Staff Writer and Photographer