Economic input-output life cycle assessment of water reuse strategies in residential buildings

The growth of cities is putting great strains on existing freshwater supplies in many areas, including the United States (Kloss, 2008). The United States Green Building Council (USGBC) has stated that buildings consume roughly 39 of all electricity and approximately 10 of all potable water (USGBC, 2008). The growing need for freshwater has lead to an increase in water reuse applications. However, some water reuse strategies actually result in an increase in energy usage and other environmental impacts. The objective of this study is to determine the environmental sustainability of three water reuse designs through economic input-output life cycle assessments (EIO-LCA). The water reuse designs include a simple greywater reuse system for subsurface landscape irrigation; an indoor greywater reuse system for toilet flushing and laundry washing; and a hybrid greywater and rainwater reuse system for landscape irrigation, toilet flushing, and laundry washing. © 2011 ASCE