In the summer of 2011, Bill Gates announced to the world that he was looking for a new toilet.  But he wasn’t just looking for any toilet.  He was looking for someone to reinvent the toilet and was willing to pay $3 million for it.

Over the last 200 years, no innovation “has done more to save lives and improve health than the sanitation revolution triggered by invention of the toilet”, explains Sylvia Mathews Burwell, president of the Bill & Melinda Gates Foundation’s Global Development Program.  The modern toilet had only reached one-third of the world.  So the foundation launched the “Reinvent the Toilet Challenge” that would call upon universities to submit proposals on how to invent a waterless, hygienic toilet that is safe and affordable for people in the developing world and doesn’t have to be connected to a sewer.

The challenge is essentially to design a product that would meet western standards without incurring western-style expenses and resource usage.  That means it shouldn’t cost more than 5 cents per person per day to use.  Plus it wouldn’t function with a sewage system popular in the West because that would require making big investments in infrastructure.  So how do we reinvent the toilet?

First it requires close collaboration with local communities.  For example, the design process would have to include consultations with the intended users to ensure that the product is something they want and will use.  A great design that nobody adopts is nothing more than useless.

It must also leverage locally available materials and knowledge for operation, repair, and maintenance.  In the past, there were cases where nobody assumed ownership of innovations such as water hand pumps or knew how to fix them when they were broken, so they were left unused.

Evidently the product must be radically lean and affordable.  A single flush from a standard toilet uses nearly 19 litres of water.  To put this into perspective, it is more than what a person living in a developing country uses in an entire day.  Since the toilet has to be off-the-grid, there needs to be a way to deal with organic waste.  But teams may not be able to apply high-tech tools that are expensive and complicated to use.

This past summer, Bill Gates announced the winners of the Challenge.  A team from the California Institute of Technology took home the top prize of $100,000 with a solar-powered toilet.  A group from the Loughborough University was awarded the second prize and $60,000 for a toilet that produces biological charcoal, minerals, and clean water.  Third place and $40,000 went to a team from the University of Toronto for a toilet that sanitizes feces and urine and recovers resources and clean water.

The University of Toronto Magazine featured the third place team who exemplifies how to approach bottom of the pyramid design.

The team conducted field research in Bangladesh to gather information from the locals.  Is there a preference for squat toilets over sit-down types?  Discoveries such as the need for women to change their clothes when using the facilities and the elderly needing assistance to use the toilet led the team to refine their prototype.  Their design also uses sand, which is inexpensive and vastly available around the world, to deal with organic waste.

And the fact that these toilets have the potential to be implemented widely at low cost could mean they may be likewise adopted in the developed world.  For starters, rural regions and campsites would be suitable beneficiaries.  As innovations for the bottom of the pyramid take into consideration the economic and environmental costs, it may be only a matter of time that western societies begin to adopt them and the way they are designed.