Understanding PCE contamination of groundwaters

In their recent recent paper, Chrisitan Moeck and his Eawag colleagues used a miniRUEDI to study the groundwater flow and perchloroethylene (PCE) transport in an urban aquifer system. They used dissolved He concentrations measured with a miniRUEDI to establish a relationship with 3H/3He groundwater ages, which allowed them to characterize the water flow and provided conceptual understanding of the groundwater system. The combination of the groundwater age data (miniRUEDI He, 3H/3He) with hydrochemical data, water isotopes (18O and 2H), and PCE concentrations showed the spatial inter-aquifer mixing between artificially infiltrated groundwater and water originating from regional flow paths. Furthermore, the correlation of groundwater age with PCE concentration explained the spatial distribution of PCE contaminations within groundwater system. In addition, faults were observed to provide preferential flow paths that lead to elevated PCE concentrations.

Full paper: C. Moeck, A.L. Popp, M.S. Brennwald, R. Kipfer, M. Schirmer: Combined method of 3H/3He apparent age and on-site helium analysis to identify groundwater flow processes and transport of perchloroethylene (PCE) in an urban area. J. Contaminant Hydrology, doi: 10.1016/j.jconhyd.2021.103773