Investigation of unknown groundwater flows to two leachate ponds at Hovgården

Sammanfattning: The leaching of groundwater into two polishing ponds, the last step in the wastewater treatment process on Hovgarden waste facility, was examined. The focus of this study was to analyse the PFAS composition profile (fingerprint) to trace the leaching groundwater. PFASs are very persistent man-made substances, used invarious fields and have been linked to several health issues. Polishing pond data and groundwater data for ions and PFAS was collected, compiled with old data and surveyed, mainly by using principle component analysis (PCA). The results indicate that there is a water flow and a mass flow of ions to the ponds, and possibly also a flow of PFAS. The ponds appear to have a different composition, which possible could be the result of a mass flow, however the macro ion distributionis similar. Of the groundwater wells, data suggests that 18G09, P3 IN and P8 were most affected by the landfill. PFOA was the most detected PFAS, and the sampling points with the highest concentration of PFAS was 18G09, P3 IN and the first sampling point (R1) in the wastewater treatment plant. While no apparent correlation between the polishing ponds and groundwater wells were discovered,data suggest that the leaching may come from some of the wells more affected by the landfill.