Life cycle assessment of three water supply systems: importation, reclamation and desalination

The issues of water supply and management will become more and more critical as the global population increases. In order to meet future demands, water supply systems must be developed to maximize the use of locally available water. It is also important to minimize the impact of water system developments on the environment. In this study, the overall environmental impacts were compared for water importation, reclamation and seawater desalination to address the water scarcity in areas where local supplies are not sufficient. The city of Scottsdale, Arizona was chosen for this study. Life Cycle Assessment (LCA) was performed and it suggests that seawater desalination has the highest impact whereas reclamation shows a relatively lower impact. However, Importation and reclamation systems have comparable results for several damage categories. The impacts of facility operations are significantly higher than the construction phase even when the life-span of infrastructure reduces from 50 year to 10 year. Due to the high impacts associated with the energy use during plant operations, different energy mixes were analyzed for their capabilities to lower the environmental burden.