PFAS-föroreningars påverkan på Gävles grund- och dricksvattentäkt : Kartläggning av potentiella riskverksamheter och bedömning av risk

Sammanfattning: The environmental toxin PFAS (per- and polyfluorinated alkyl substances) is a heterogeneous synthetic industrial chemical group that has been used since the 1950s which, due to its attractive properties, has a wide range of applications in our society. PFAS are persistent and bioaccumulative, which means that the levels increase in the environment over time; At higher levels, the substances are toxic and show a negative effect on human health. PFAS spread through air and water; in particular, the PFAS group PFAA (perfluorinated alkyl acids) poses a threat to the safe drinking water supply due to its rapid mobility and long-distance transport in aquatic environments. The main objective of this study was to investigate the potential impact of PFAS contaminants on Gävle's groundwater source through a simplified risk assessment. By mapping risk activities (use of firefighting foam, industries, and landfills) that can cause the introduction of PFAS pollutants to the groundwater source, comparing limit values and making a current situation description, the aim was to assess whether the risks to the environment and human health are acceptable or not. The study was conducted with mixed methods containing both quantitative and qualitative parts to provide several perspectives regarding the potential impact of PFAS contaminants on Gävle's groundwater and drinking water supply. The results identified two industrial operations where soil contamination by PFAS was found. Furthermore, the comparison between the limit value for PFAS4 in drinking water (4 nanograms per liter) and the mean value of Sum PFAS4 within the areas of the study shows PFAS concentrations exceeding the Swedish limit value. The description of municipal measures regarding drinking water reflects Gästrike Vatten AB's PFAS purification pilots. The study's conclusions are that the use of firefighting foam containing PFAA probably caused the contamination situation. Gästrike Vatten AB's ongoing and completed purification pilots in the Valbo and Sätra waterworks lead to the installation of purification systems that will be able to reduce the levels of PFAS4 in the drinking water in Gävle municipality to acceptable levels. The overall conclusion based on the risk assessment is that it is currently not possible to assess whether the risks are acceptable or not as a result of the continued supply of PFAS and groundwater sensitivity. However, Gästrike Vatten AB has taken measures regarding drinking water and are in-depth source tracking.