ANALIZA ZMIAN SKŁADU CHEMICZNEGO WÓD PIĘTRA TRIASOWEGO W POCZĄTKOWEJ FAZIE ZATAPIANIA KOPALNI TRZEBIONKA

Abstract

ANALYSIS OF CHANGES IN WATER CHEMISTRY OF THE TRIASSIC AQUIFER IN THE INITIAL PHASE OF THE TRZEBIONKA MINE FLOODING

Abstract. The mining of Zn-Pb ores in the Trzebionka mine made it necessary to drain the deposit. This process led to changes in the groundwater table within the main level of the Triassic aquifer. The aquifer located in the Muschelkalk carbonate and Buntsandstein (Röt) formations constitutes the main groundwater reservoir for the major groundwater basin No. 452 Chrzanów in the impact zone of the mine-pumping cone of depression. Due to the depletion of reserves, mining was terminated in 2009 and the drainage of the pits was stopped. The closed-down W³odzimierz main shaft was adapted to serve as a piezometer for the observation of the total flooding of the mine, which began in mid-2010 after turning off the main drainage pumping station. Water level measurements and tests of selected physico-chemical parameters of mine waters take place in the piezometer. Based on the results of research conducted in 2010–2012, an analysis of changes in the water chemistry of the Triassic aquifer was conducted in the Włodzimierz shaft. The changes in the content of sulphates, zinc, lead, pH and conductivity in pit water samples were analysed and compared to the measurements of water-table position in the corresponding periods of time. A comparison of the water-table restoration curve to the curve of sulphate content changes shows that as the level of the water table increases so does the concentration of sulphates. This is most likely related to flooding of the mine and continuous transition of sulphates into the aqueous solution.