Environmental analysis of a domestic rainwater harvesting system: A case study in France

Life cycle assessment methodology along with water footprint analysis was used to assess the environmental impacts of a domestic rainwater harvesting system (RWH) in France. Firstly, the relevance of substituting drinking water (DW) with rainwater in a private individual household was studied. Secondly, the effect of several parameters namely construction of infrastructures, building scale and disinfection were evaluated. The quantification of environmental impacts was performed using Ecoinvent inventory data and Impact 2002+ evaluation method. The water footprint was assessed through the water stress indicator (WSI). From an environmental standpoint, the RWH system has only slightly higher impact than the DW system. The consumption of electricity for pumping generates the strongest impact. The analysis of the WSI showed that the RWH system can relieve a stress on water resources where it exists. Consideration of infrastructures and disinfection turns environmental impacts significantly higher in all impact categories. Setting up the RWH system at bigger scale, i.e., building scale, is a bit less favoured than the RWH system at household scale. This study aims at pointing out areas of improvement which need to be further studied to make RWH systems more sustainable.