This South African river has a bacteria count off the charts: a natural filter is cleaning it for watering food gardens

Every day, millions of litres of polluted water flow through many South African rivers and disappear into the sea. In South Africa, the small Stiebeuel River in Franschhoek, about 75 kilometres east of Cape Town, is badly polluted. Sewage and polluted rainwater run into the river because of inadequate sanitation and drainage systems serving the nearby informal settlement of Langrug. About 26,000 people there live in densely populated housing, where ageing and overstretched infrastructure…