Numerical modelling of reactive transport using aquifer analogue data

Even at well-instrumented groundwater research test sites like Borden or Cape Cod, the subsurface characterization of the aquifer systems is insufficient to predict the detailed transport of a reactive solute. Real world data sets are required as benchmarks or groundwater risk assessment, clean-up studies or for the optimization of subsurface investigation methods. With respect to the hydrostratigraphic structure of an aquifer, outcrop analogue studies conducted in hard and soft rock formations have helped to obtain high resolution parameter data sets characterizing the heterogeneity of such systems. So far these studies have relied only on small-scale laboratory hydraulic measurements and they mostly ignore the hydrogeochemical parameter heterogeneity. This paper presents the first results of a new approach to the aquifer analogue concept, which incorporates hydraulic, geophysical, hydrogeochemical and sedimentological methods, yielding 2-D and 3-D high-resolution multi-parameter data sets of unsurpassed quality. Their importance for the prediction of the reactive transport of dissolved organic compounds is demonstrated within a numerical simulation study.