Natalia Fernandez together with her research group, HGeo³-Hydrogéologie et Géologie de l'Environnement, proceeded with the installation of the Vadose Monitoring System (VMS) in Belgium in June 2013. The objective was to develop a methodology able to quantify contaminant fluxes, identify their sources and pathways and understand the various reactive processes in soil and groundwater.
The combined experiment consisted of a tracer test performed directly in the vadose zone via infiltration rings, located within an infiltration pond. To do this, a flexible sleeve was installed in a slanted borehole with the aim of capturing a tracer infiltrated throughout undisturbed material above the borehole. To measure water content, Flexible Time Domain Reflectometry probes (FTDR), which contain stainless steel waveguides, were installed in the outer wall of the flexible sleeve. As well, Vadose Sampling Ports (VSP) were placed in the inner wall of the flexible sleeve for sampling pore water in the vadose zone. Finally, additional boreholes were installed in the unsaturated zone to conduct cross-hole geophysics with the aim of monitoring contaminants and tracers as they move into the saturated zone.
The outlook of this experiment was to use the advantages of the combination of the Vadose Monitoring System and geophysical techniques with the aim of developing a conceptual model that better characterised the transport of pollutants in the vadose zone of industrial sites. The objective was to use such a methodology as an approach to improve risk assessment and remediation measures for the vadose zone.
