Investigation and evaluation of hydrogeological surveying methods for sediments overlying salt formations

Abstract

Safety assessment studies are currently being carried out in relation to the final disposal of hazardous chemical or radioactive waste in rock-salt formations. Subrosion of rock-salt is considered to be one of the important natural processes that could reduce the barrier function of the rock-salt and ultimately induce release of disposed waste into groundwater. In order to validate the geohydrological models for subrosion, the deep groundwater system and the origin of the dissolved salts should be known. The aim of this project is to find out which methods are suitable to obtain relevant geohydro- logical and geohydrochemical data and to indicate, if possible, their uncertainty. The geohydrological methods used for this purpose have been subject of studies described in two previous interim-reports. This report concerns the geohydrochemical methods.