Resumen
The increasing scarcity of water is encouraging strategies in water saving and urban water management systems devoted to reducing natural resource consumption and environmental impact. At household and urban scales, there is an increasing interest in onsite greywater and non-potable water reuse systems in order to improve water availability. In this framework, the project GST4Water funded by the European Union (EU) under the POR-FESR 2014?2020 Program of Emilia-Romagna Region, has been developed with the aim to implement water consumption monitoring systems, to define solutions for greywater reuse, and to develop tools for environmental sustainability evaluation applied to water systems. The present study focuses on this last goal, performing a life cycle assessment of the solutions optimized at a district level. In particular, six different scenarios are compared, starting from two models considering traditional water supply together with or without energy consumption related to hot water generation, and five additional models related with different assumptions in terms of greywater recovery systems, and energy and hot water production, at varying percentages of renewable and photovoltaic energy supply. Finally, an evaluation of the return time of environmental investment is carried out, based on the results obtained through the scenario analysis.