Wastewater irrigation and environmental health: Implications for water governance and public policy

Climate change is a large-scale and emerging environmental risk. It challenges environmental health and the sustainability of global development. Wastewater irrigation can make a sterling contribution to reducing water demand, recycling nutrients, improving soil health and cutting the amount of pollutants discharged into the waterways. However, the resource must be carefully managed to protect the environment and public health. Actions promoting wastewater reuse are every where, yet the frameworks for the protection of human health and the environment are lacking in most developing countries. Global change drivers including climate change, population growth, urbanization, income growth, improvements in living standard, industrialization, and energy intensive lifestyle will all heighten water management challenges. Slowing productivity growth, falling investment in irrigation, loss of biodiversity, risks to public health, environmental health issues such as soil salinity, land degradation, land cover change and water quality issues add an additional layer of complexity. Against this backdrop, the potential for wastewater irrigation and its benefits and risks are examined. These include crop productivity, aquaculture, soil health, groundwater quality, environmental health, public health, infrastructure constraints, social concerns and risks, property values, social equity, and poverty reduction. It is argued that, wastewater reuse and nutrient capture can contribute towards climate change adaptation and mitigation. Benefits such as avoided freshwater pumping and energy savings, fertilizer savings, phosphorous capture and prevention of mineral fertilizer extraction from mines can reduce carbon footprint and earn carbon credits. Wastewater reuse in agriculture reduces the water footprint of food production on the environment; it also entails activities such as higher crop yields and changes in cropping patterns, which also reduce carbon footprint. However, there is a need to better integrate water reuse into core water governance frameworks in order to effectively address the challenges and harness the potential of this vital resource for environmental health protection. The paper also presents a blueprint for future water governance and public policies for the protection of environmental health.