Confronting the realities of wastewater use in agriculture

Based on research presented in ?Urban-Wastewater Reuse for Crop Production in the Water-Short Guanajuato River Basin Mexico (IWMI) Research Report 41) by C. Scott, J.A. Zarazua and G. Levine; ?Urban Wastewater: AValuable Resource for Agriculture: A Case Study from Haroonabad, Pakistan (IWMI Research Report 63)? by W. van der Hoek, M. Ul Hassan, J. Ensink, S. Feenstra, L. Rachid-Sally, S. Munir, R. Aslam, N. Ali, R. Hussain and Y. Matsuno: and ?Use of Untreated Wastewater in Peri-Urban Agriculture in Pakistan: Risks and Opportunities (IWMI Research Report 64)? by K Ensink, W. van der Hoek, Y. Matsuno, S. Munir and R. Aslam.In urban and peri-urban zones in developing countries, poor farmers commonly use nutrient-rich sewage and wastewater to irrigate high-value crops. In many places, this untreated wastewater is their only source of irrigation water?so their livelihoods depend on it. But, as well as bringing benefits, the unregulated use of wastewater also poses risks to human health and the environment. The prevailing ?scientific? approach to wastewater irrigation advocates treatment before use and the implementation of strict regulations. But many developing countries can?t afford to build treatment facilities and do not have the resources to enforce regulations. There are other options, as IWMI research in Mexico and Pakistan demonstrates. Well-crafted policies on wastewater use have the potential to improve the incomes of poor urban and peri-urban farmers and reduce pollution of lakes, streams and aquifers. Continuing to turn a blind eye to wastewater use can result in higher incidences of disease among farmers and consumers and in irreversible degradation of the environment. Policymakers need to develop comprehensive strategies for managing wastewater tailored to local socioeconomic and environmental conditions and for analysis of the short- and long-term risks and benefits of all available options