An industrial sources-based methodology for the prioritization of site-specific emerging contaminants in water resources

Global population growth, industrialization, urbanization, and climate change have been shown to be major drivers leading to degradation of water resources, especially those designed for human and animal consumption. In this context, Water Safety Plans (WSPs) have been introduced to identify and assess potential site-specific risks as well as to develop mitigation strategies aimed at preventing and minimizing impacts. One of the crucial steps in the application of the WSP approach is to assess the risk posed by potential sources of contamination and to identify which chemicals may be of concern for a specific drinking water supply area. Identifying substances that may represent a risk based on their chemical-physical-toxicological profile, but which have not yet been monitored, and which could reasonably be present in the territory due to specific, often not very evident, explicit, and difficult to trace industrial processes is a complex but fundamental exercise within the implementation of a WSP. This is particularly challenging since chemical compounds and ingredients are renewed very quickly according to production needs and technological improvements. In this work, we developed an approach to identify these substances by integrating information reported in the European CHemical Agency (ECHA) database with site-specific data on industrial activities. The proposed approach was implemented within the deeply industrialized area of the Veneto Region (Italy), specifically located at the foothills of the Alps where major aquifers are being used for water provision, historically affected by severe groundwater/surface water contamination. A list of 46 non-regulated chemicals of concern was obtained, and the substances were further prioritized based on chemical PMT characteristics, site-specific environmental occurrence, and the quantity of wastewater discharged by the industrial activities. The results were consistent with those reported in similar prioritization exercises implemented at the EU scale, although several peculiarities emerged due to specific local characteristics of the case study area. The identification of chemical substances and other parameters of concern (especially if not yet regulated) represents an essential and undelayable propaedeutic activity for the definition of a coherent and evidence-based monitoring plans.