Toxic substance accumulation prediction: A useful addition to conventional life cycle assessment when comparing water recycling technology

One aspect of decision making in water recycling is the need to evaluate the environmental performance of different treatment technologies. Life Cycle Assessment (LCA) is identified here as a suitable initial tool that can be used to address a wide range of potential environmental impacts caused by each technology under study over their life-time. In this paper, the results of a case study in which LCA is used in evaluating three water recycling technologies are reported. One of the findings from the case study is that LCA fails to account for the potential accumulation of toxic substance which is a major concern in water recycling, particularly when applications such as irrigation are of interest. A Toxic Substance Accumulation (TSA) prediction method is described which was tested with the same treatment technologies assessed in the LCA case study. The information on land use impacts obtained from the LCA study including Terrestrial Ecotoxicity Potential (TETP) and Salinisation Potential (SP) is compared with the information derived from the TSA method. It is found that the additional information obtained from the TSA method adds value to the environmental impact assessment of water recycling at both process and policy making levels and also assists in addressing the issue of sustainability of water recycling practice.