This off-grid toilet uses sands to work. Sandi is an off-grid waterless toilet concept with minimal construction and operating costs. It's made to offer a dignified, viable solution for low-income countries and rural families without water, sewage systems or septic tanks. Sandi was designed by Archie Read, a graduate of London's Brunel University. He came up with the idea while interning for toilet company LooWatt in Madagascar. Read priced the toilet at $74 each and hopes NGOs can buy or rent t