Eawag and Uni Neuchatel teamed up to develop and test the miniRUEDI as a tool for artificial tracer tests using different noble gases.
In a first test, helium pulses were injected into a river. A miniRUEDI was used to analyse the He concentrations in the nearby groundwater system, where the observed He breakthrough indicated a substantial loss of river water to the underlying aquifer.
In a second test, multiple pulses of different noble gases (He, Kr and Xe) were repeatedly injected at different locations into an aquifer. A miniRUEDI was used to record the breakthrough curves of the different gases in the downstream groundwater flow, which provided insights into the groundwater flow field, and showed how the flow field responded to modifications in the hydraulic connectivity of a nearby river to the aquifer.
In both tests, the miniRUEDIs efficiently provided valuable new insights into river/groundwater exchange and its effects on the groundwater quality.
Publications:
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T. Blanc, M. Peel, M.S. Brennwald, R. Kipfer, P. Brunner: Use of helium as an artificial tracer to study surface water/groundwater exchange. EGU21-9005, doi: 10.5194/egusphere-egu21-9005
- M.S. Brennwald, M. Peel, T. Blanc, Y. Tomonaga, R. Kipfer, P. Brunner, D. Hunkeler: New Experimental Tools to Use Noble Gases as Artificial Tracers for Groundwater Flow. Frontiers Water, doi: 10.3389/frwa.2022.925294