title: Life cycle assessments of urban water systems: a comparative analysis of selected peer-reviewed literature.
abstract: Water is a growing concern in cities, and its sustainable management is very complex. Life cycle assessment (LCA) has been increasingly used to assess the environmental impacts of water technologies during the last 20 years. This review aims at compiling all LCA papers related to water technologies, out of which 18 LCA studies deals with whole urban water systems (UWS). A focus is carried out on these 18 case studies which are analyzed according to criteria derived from the four phases of LCA international standards. The results show that whereas the case studies share a common goal, i.e., providing quantitative information to policy makers on the environmental impacts of urban water systems and their forecasting scenarios, they are based on different scopes, resulting in the selection of different functional units and system boundaries. A quantitative comparison of life cycle inventory and life cycle impact assessment data is provided, and the results are discussed. It shows the superiority of information offered by multi-criteria approaches for decision making compared to that derived from mono-criterion. From this review, recommendations on the way to conduct the environmental assessment of urban water systems are given, e.g., the need to provide consistent mass balances in terms of emissions and water flows. Remaining challenges for urban water system LCAs are identified, such as a better consideration of water users and resources and the inclusion of recent LCA developments (territorial approaches and water-related impacts).
authors.affiliation: Irstea, UMR ITAP, 361 rue Jean-François Breton, F-34196 Montpellier, France; Veolia Eau d'Île-de-France, 28 Boulevard du Pesaro, F-92739 Nanterre, France; ELSA, Research Group for Environmental Life Cycle Sustainability Assessment, 2 Place Pierre Viala, F-34060 Montpellier, France. Electronic address: philippe.loubet@irstea.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Loubet
authors.affiliation: Irstea, UMR ITAP, 361 rue Jean-François Breton, F-34196 Montpellier, France; ELSA, Research Group for Environmental Life Cycle Sustainability Assessment, 2 Place Pierre Viala, F-34060 Montpellier, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Roux
authors.affiliation: Irstea, UMR ITAP, 361 rue Jean-François Breton, F-34196 Montpellier, France; ELSA, Research Group for Environmental Life Cycle Sustainability Assessment, 2 Place Pierre Viala, F-34060 Montpellier, France.
authors.forename: Eleonore
authors.initials: E
authors.lastname: Loiseau
authors.affiliation: Irstea, UMR ITAP, 361 rue Jean-François Breton, F-34196 Montpellier, France.
authors.forename: Veronique
authors.initials: V
authors.lastname: Bellon-Maurel
mesh_terms: D002947:Cities; D003247:Conservation of Natural Resources / Q000379:methods*; D060766:Drinking Water / Q000592:standards*; D013597:Systems Analysis; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
chemical_list: D060766:Drinking Water
keywords: LCA; Review; Urban water system; Water resources; Water technology; Water user