Murendeni Mafumo is one of many young South African innovators taking simple solutions to South Africa’s complex water and sanitation problems. He is the inventor of a water purification system that harnesses macadamia nut shells and nanotechnology to deliver clean, safe drinking water to communities which are not connected to the municipal water supply. To keep his projects sustainable, he has started a scheme under his social enterprise, Kusini Water, in which he sells bottled water as well as his water filtration devices. For every litre of water sold, his project is able to provide 20 litres of water to the communities he works with.