A LIFE CYCLE ASSESSMENT APPLICATION TO EVALUATE ENVIRONMENTAL ISSUES IN SAVING AND REUSING WATER AT DOMESTIC LEVEL

The paper would show the results of a project for the development and application of life cycle analysis (LCA) to domestic water consumption, with the aim of highlighting the importance of saving water resources and the convenience, in terms of reduction of environmental impacts, in the use of specific technologies for rainwater harvesting and gray water recycling, such as tanks. This will enable the recovery, treatment and reintegration of the resource for some specific uses only (like toilet and water intended for outside uses), in compliance with health and hygienic standards laid down in legislation, evaluating the impacts and the environmental, social and economic sustainability linked to the performance of this specific technology. The LCA analysis quantifies, therefore, the sustainability of the use of water resources, contributing to the improvement of the production chain, distribution and use of water and affecting the training phase of the consumption, so as to promote water saving and the reduction of withdrawals from the environment. In detail, the software used will enable to compare the sustainability of the current user’s consumption conditions with respect to solutions allowing for the reuse of gray water and rainwater with resulting benefits in terms of wastewater’s volume reduction to be purified and drained. Sustainability assessments will also take into account the global pressure factors, human activities, such as those resulting from climate change and population’s increase. Results refer to the functional unit of 1 liter of water per person per day, consumed or saved, and are organized into four damage’s categories, quantified by a score, allowing direct comparison between them. For a more reliable and comprehensive analysis, only inputs imposed to the system by the analyzed scenarios were considered, including water and energy consumption. For the waste water’s assessment, with the same assumptions above, reference was made to the Municipal treatment plant of a small town in Emilia Romagna Region. Analysis boundaries extends from the water’s collection, purification and distribution to the user, up to the leakage of the consumed water in the sewage and its treatment, including in the input any chemical substances needed for their treatment, during both deployment and disposal phases. All input are considered as a function of a mass balance, that has allowed to highlight the savings, both in terms of water resources and the environmental impacts.