Environmental Sustainability Assessment of Treated Wastewater Reuse: A Case Study

Mismanagement of existing water supplies is threatening the sustainability of these resources, resulting in the degradation of source water quality and decreasing water supplies. Notably, substantial amounts of source water are withdrawn and treated for industrial use, irrigation, thermoelectric power, and mining purposes; only a small portion is allocated for municipal and domestic purposes. The increasing incidence of extreme weather events further accentuates both water quality and quantity concerns, stressing the need for increased efficiency to improve water supply sustainability. To that end, substituting source water with recycled water can help improve water supply sustainability in many places across the United States and the rest of the world. In this article, we focus on the case of Joliet, a town in Illinois where the supporting aquifer verges on the point of nonviability. To assist Joliet, Chicago's City Council approved a plan for the Chicago Department of Water Management to reallocate Lake Michigan drinking water from the Chicago basin to Joliet. In this study, we evaluate the environmental sustainability of four possible scenarios: 1.) proposed water-use cycle from the water treatment process, with delivery to all users, 2.) supplying recycled water to industries and other potential non-potable uses without additional treatment, 3.) supplying recycled water treated with additional disinfection to industrial and other non-potable uses, and 4.) supplying recycled water from an alternative water reclamation plant with an existing disinfection unit. We perform a life cycle assessment to compare the environmental impacts in each scenario. Findings of the study show that treated wastewater in industrial applications would significantly reduce environmental emissions compared to the proposed no-reuse scenario. The results suggest that water reuse can help save energy, reduce potable water consumption, generate revenue, and reduce the environmental load on water bodies.