Social aspects of water consumption: risk of access to unimproved drinking water and to unimproved sanitation facilities—an example from the automobile industry

Abstract

The main aim of this study is to provide a methodology for assessing the social impacts related to water consumption in life cycle assessment (LCA). Methods for the environmental assessment of water use in LCA have already been developed. However, the impacts of water consumption from a social life cycle perspective, which are also site-dependent, still need to be addressed. According to a sustainability concept, freshwater sources should be assessed by considering the social and economic, as well as the environmental impacts. For the life cycle inventory (LCI) modelling, blue water flows from production processes are separated into direct process water and indirect water from energy production. Primary data, published studies and the GaBi 6© software’s Database serve as sources for this study. Risk of access to unimproved drinking water (RADW) and risk of access to unimproved sanitation facilities (RASA) are the social indicators selected for consumed water based on published data and according to the guidelines for social life cycle assessment (S-LCA). In the automobile industry, the social assessment is applied in the production stage of a conventional vehicle instrument panel. In order to show the influence of site-dependent aspects on these social indicators, three production sites (China, Germany and South Africa) are compared. The inventory is also used for an environmental assessment based on water stress indices (WSI), thereby confirming the compatibility of both social and environmental assessments. Results showed that the instrument panel manufactured in China is the most water-intensive alternative. Indirect water was the main driver for water consumption in all processes. The hotspots of water consumption are found in the supply chain processes, where isocyanate production embraces the most water-intensive processes. China is the country where the water consumed in the production processes by the manufacturer led to the highest risk of accessing unimproved drinking water and sanitation, i.e. not protected from contamination, for the local community. Of all processes, the amount of water consumed by the energy production processes was the highest. Thus, the instrument panel manufactured in China led to the highest environmental impact as well. A feasible and practicable method for a social risk assessment of freshwater consumption for automotive products is proposed. This contributes to the method development leading towards a comprehensive life cycle sustainability assessment (LCSA) of freshwater. The approach provides valid indicators for decision makers. Furthermore, the social assessment is implemented in an industrial product with a simplified supply chain. It has been shown that the social assessment is consistent with an existing environmental assessment, this being a first practical step for a sustainability assessment of water use for the automobile industry. The proposed method should be integrated in commercialised databases for assessments of an entire vehicle in order to facilitate its implementation. In addition, the economic pillar needs to be included for a comprehensive LCSA of water use. Further case studies should allow for a finer granularity in regional assessment, if required for the decision makers.