Geological characterization of contaminated sites in urban areas (Denmark).

In Denmark, contaminations from industry and farming represent a significant threat to groundwater resources. Hence there is a focus on identifying and locating these contaminated places. Once located, contaminations are mapped and monitored and remediation efforts are undertaken. Remediation is often time consuming and expensive. Moreover, as cities expand, many contaminations are now located in urban areas where data compilation and remediation efforts are often challenged by logistics. The general lack of knowledge about theses contaminations introduces significant uncertainties in the projections on the fate of the contaminant.
From two contaminated sites located around the city of Horsens, Denmark we carry out a geological characterization. The two sites are situated in urban areas. Existing data from the two field sites includes only lithological profiles from boreholes. In order to increase the density of the field data, the two areas were mapped using combined Electrical Resistivity Tomography (ERT) and Induced Polarization (IP), and a multi-configuration Ground Conductivity Meter (DualEM421).
Based on the borehole information and the high-density geophysical data, detailed 3D geological models of the two sites were constructed. The 3D geological models will serve as a basis for simulating groundwater flow and contaminant transport at the field sites. The study demonstrates how detailed information about the geological setting in conjunction with contaminant transport modelling, can minimize the uncertainties on predictions of the fate of the contaminant.
Based on the work, we were able to pinpoint the best strategies and solutions for future remediation efforts at the two sites.