Fast Company tells us that half a billion people do not have regular access to private toilets or reasonably sanitary communal latrines. This can create serious public health problems. In response, Archie Read, a graduate student in architecture at Dundee University, designed the Sandi.
This toilet requires no running water at all. The design separates urine and feces. The urine is stored in a bucket that should be emptied and used as fertilizer every seven days. The white handle on the side operates the flushing mechanism for feces, turning a sand-covered conveyor belt into a different container. Once full, that container can be buried for four weeks and then used as compost.
Reed discovered that sand prevents feces from sticking to the conveyor belt, thus inspiring the product name of Sandi.