Sustainable Management of Wastewater for Agriculture: Proceedings of the First Bridging Workshop

Abstract

As much as 60% of the global population is expected to suffer water scarcity by the year 2025. With increasing competition for good-quality water among different sectors, the availability of water for agriculture will likely decline, especially in water-scarce countries. The water taken away from agriculture is diverted to household, municipal, and industrial activities. Since the use of freshwater for these activities generates wastewater, the volume of wastewater has increased. The productive use of wastewater has also increased, with millions of small-scale farmers in urban and peri-urban areas of developing countries using wastewater sources to irrigate a range of crops. Water-scarce countries will have to increasingly rely on such alternative water resources to narrow the gap between freshwater demand and supply. There is limited available information on the extent of wastewater resources that could be potentially exploited in water-scarce countries. Even where data are available, assessment of these resources is complicated by the different criteria used to identify and categorize them. In addition, information on the productivity potential of wastewater, its impacts on the environment, and the social and economic conditions of the dependent farming communities are also limited. Recycling of treated wastewater needs to be promoted. In many parts of the developing world, large amounts of untreated or inadequately treated wastewater are currently used by farmers, usually in an uncontrolled manner – raising concerns about public health and the environment. This situation warrants rethinking the ways in which wastewater is handled and reused in crop production systems. The development of appropriate technical and policy options for wastewater in water-scarce countries offers great promise for the foreseeable future. However, the capacity, skilled human resources, and research-based knowledge are lacking in develop ing countries to tackle the complex issues arising from the agricultural use of wastewater.