Stanford University, 2011 - $18,985

The General Population Census of Cambodia in 2008 found that 76.8% of the rural population still practices open defecation. As a result, diarrheal diseases are the number one cause of sickness and death amongst Cambodian children, with 20% of children under five years old suffering from diarrhea. At the same time, most Cambodian fields are under-fertilized, with UN estimates suggesting that only 30% of rice fields receive even minimal fertilizer application. Too often, poor farmers fertilize their fields with raw human waste, leading to widespread illness.

This team has designed the EZ*PZ, an inexpensive (~$4) device that converts urine into a safe fertilizer. Essentially half a toilet that goes on the front part of a latrine squat pan, the EZ*PZ ensures that urine, feces, and blackwater are separated at the point of collection. The urine ends up in a clear plastic jug, where it’s treated immediately with direct sunlight. This pathogen-free fertilizer can then be combined with water and applied directly to vegetables and other crops. Preliminary tests indicate that users of the device will see rapid increases in crop yields and improvement in public health.