Water scarcity problems will continue to exacerbate in many parts of the world, urging society to mitigate or adapt. Consequently, unconventional water resources, such as municipal wastewater, are becoming more relevant. This thesis aims to measure and evaluate the social impacts of wastewater treatment (WWT) systems potentially stemming from the social performance of organizations and social risks in the value chain. Two WWT systems are studied: one is the current WWT facility operating in La Llagosta, Barcelona, Spain (reference system), and the other is one of the case studies of the Water Mining (WM) project (original system). The WM project aims to apply innovative approaches to recover clean water and other resources from municipal and industrial wastewater and seawater.
Social life cycle assessment (S-LCA) was applied to evaluate the social performances of organizations in a site-specific assessment and to assess the social risks along the systems’ value chains in a generic assessment through PSILCA. The results of the latter show that, in both systems, most risks occur in some subcategories from the “Workers”, “Local community”, “Society”, and “Value chain actors” stakeholder categories. The results of the former indicate that the organizations performed relatively well in both systems. However, improvements are needed in some subcategories. Moreover, after accounting for each organization’s share and allocating the results, the original system’s performance is better than the reference system in most subcategories. For each organization that did not achieve the acceptable level (Basic Requirement), suggestions for improvement are offered. Finally, although social performances could be linked to a product and multifunctionality could be solved, the results must be interpreted with caution in light of the limitations of S-LCA. Further research is needed for the assessment of the social implications of circular systems.