Most common in Asia and sub-Saharan Africa, wastewater use is critical to farmers’ incomes, urban food security but raises health concerns.
As developing countries confront the first global food crisis since the 1970s as well as unprecedented water scarcity, a new 53-city survey conducted by the International Water Management Institute (IWMI) indicates that most of those studied (80 percent) are using untreated or partially treated wastewater for agriculture. In over 70 percent of the cities studied, more than half of urban agricultural land is irrigated with wastewater that is either raw or diluted in streams.