Chemical composition and microbiological profile of karst water in the Krásnohorská Cave (Silická plateau, Slovak Karst)

Detailed chemical and microbiological research was realised in the Krásnohorská Cave and its underground hydrological system (2009–2011). Predominant part of the cave is formed in Gutenstein dolomites and dolomite limestones, rear parts of the cave are located in chemically pure Steinalm limestones of the Silicic Unit. Chemical composition, quality and microbiological properties of karst water in the cave system were overall evaluated on the basis of 55 chemical and 41 microbiological analyses and results of continual measurement of electric conductivity and water temperature. The chemical composition of water is relatively stable during year. Carbonates and calcium are dominant ions in water and is formed water with carbonate mineralization. Values of the total dissolved solids (TDS) are from 488 to 1,097 mg·L-1. Cave water is primary Ca-HCO3 and Ca-Mg-HCO3 type, but locally Ca-SO4 type is found as well. Results showed differences between some parts of cave system and confirmed occurrence of higher mineralized water caused by higher concentration of sulphate (max. 322.6 mg·L-1). This type of water is rare in the cave system of the Silická Plateau. Generally and prevailingly water is in equilibrium with calcite and aragonite, in equilibrium or undersaturation with dolomite and in undersaturation with gypsum.