Stanford researchers rethink sanitation system for urban slums

Two researchers -- Sebastien Tilmans and Kory Russel -- at Stanford University in northern California on the U.S. west coast have developed a system to deal with toilet waste that does not require water.

Using a door-to-door waste removal service, people living in some of the poorest slums in Haiti have been able to ward off some of the infectious diseases associated with human fecal matter that were plaguing neighborhoods in the Caribbean nation.

The so-called container-based sanitation, or CBS, is intended to be a short- or long-term solution in urban slums of Haiti and elsewhere, where conventional sewerage is not feasible due to the need for large up-front capital investments and reliable water and energy supplies.

Tilmans told Xinhua that the "dry toilet" resembles a regular sanitation system, though users will not be able to find a flush. A trial version of CBS was put in use in Haiti for three months.

Tilmans and Russel began working on the idea in 2012, following an exhibition at the university that showcased the portable toilet system.

"We took the concept of a dry prefabricated toilet with two compartments, one for urine and one for fecal matter," Tilmans said, "and worked on it to adapt it to Haiti's culture." Once the waste is deposited in its compartment, the user throws cover material on top of it to avoid smell, insects and the spread of infectious diseases.

Of the estimated 2.5 billion people worldwide who lack access to adequate sanitation, about 750 million live in cities.

As part of their local approach, Tilmans and Russel had to rethink what kind of materials could be used as a cover for the waste. In Haiti, the two used a mixture of coconut shell shavings and other local products that can be easily obtained.

The researchers, both of whom have recently obtained doctoral degrees in environmental engineering at Stanford, partnered with a local nongovernmental organization to coordinate the setting up of waste removal service trucks that patrol the slums once a week and take the fecal matter to a local composting factory. Users pay a small monthly fee for the service.

After three months, the project reached more than 130 households. The researchers are now moving to test it on a larger scale and are leading the same pilot project in Peru and Kenya through an entrepreneurial initiative with the aim of bringing the CBS system to other developing countries. Endi