Survey of polar organic micropollutants in German tap waters

Tap waters from 91 locations across Germany were analysed for organic persistent and mobile (PM) substances, covering a range of sources and substance classes, e.g. the sweetener saccharine (SAC), antibiotic drug sulfamethoxazole (SMX), pharmaceutical transformation product valsartanic acid (VSA), industrial chemicals as cyanoguanidine (CG) or ultra-short-chain PFAS trifluoroacetic acid and trifluoromethanesulfonic acid (TFA and TFMSA). The investigated sampling sites differed by their respective raw water resources and population density (rural and urban). Enrichment by azeotropic evaporation was successful for 11 of 26 substances and decreased the limit of detection and limit of quantification by more than ten-fold. Concentrations of 19 studied substances were well below the health-related indicator value (HRIV) or health-based guideline value (HBGV) in all samples. However, the HRIV for CG, SAC, SMX and VSA were exceeded in two, one, one and five samples respectively, with exceedances ranging from 4 % for SMX to 117 % for CG. Nevertheless, it can be stated that - with a few exceptions - the precautionary values protecting human health are complied with. TFA and TFMSA were detected in every sample with 90-percentile concentrations of 5.2 μg/L and 4 ng/L, respectively. The study shows that PM substances in particular can penetrate into drinking water.