ABSTRACT
Mine dewatering operations in the Transdanubian Mountains, Hungary between 1960 and 1990 caused significant groundwater depressurisation and drying up of several karst springs in the city of Tata. Following the termination of mining operations, the groundwater flow system started to recover. Many of the former springs reactivated and further springs are expected to reappear in the future, causing environmental issues. Spring locations in Tata are aligned with deep tectonic structures both in uncovered and confined karst areas. The analysis of well hydrographs indicates that there is no hydraulic connection between shallow and karst groundwater bodies. The prediction of karst water levels based on physical curve fitting suggests that equilibrium karst water level will be reached around the year 2018 at approximately 140 m asl. The chemical composition of karst waters in the Tata region confirms that they come from a dolomitic aquifer. While the karst waters of the region show a uniform composition, shallow groundwater shows a variable composition. The chemical composition of most reactivating springs indicates karst water origin. Some springs discharge shallow groundwater and show signs of local pollution.
