The Use of Surface Geophysics to Determine the Aquifer Characteristics in the Folldal Mining Site, Norway

Over two centuries of mining activity in Folldal area (Norway), now an industrial cultural heritage site, led to large amounts of uncovered waste materials. The exposure and subsequent oxidation of these materials produces acid mine drainage, which is discharging into the River Folla. Integration of surface geophysical and hydrogeological field methods was necessary to further obtain hydrogeochemical numerical models to assess the fate of the acidic groundwater, its contribution to the river and predict the effect of remediation. Seismic refraction and electrical resistivity tomography (ERT) were essential tools to characterize the aquifer geometry, locate the water table and obtain an overview of the topsoil sedimentological changes without altering the historical site. From the integration of the methods, the aquifer was characterized as a one single sedimentary layer aquifer of 30-40 m depth and areas with different hydraulic conductivity were defined, which permitted to obtain accurate groundwater flow.