Hydrochemicky a hydrogelogicky monitoring testovaci lokality melechovsky masiv

Within the frame of the project of the Radioactive Waste Repository Authority carried out the detailed geological investigation on the area of the Melechov pluton testing site was realised. Hydrogeological and hydrochemical monitoring of the groundwater was one part of the investigation. The most important aim was the location of important hydrogeologically active fractures. The results argue for a reasonable agreement in identification of the fractures with geophysical results. The monitoring was focused on the observation of physiochemical parameters (water temperature, pH, specific conductivity, discharge) of 22 springs and water discharge of selected 7 water-courses and their temporal changes in relation to elevated precipitation. Chemical analyses of the main components (Na, K, Mg, Ca, Li, Fe, Al, SiO2, Cl, NO3, SO4, F, NH4), alkalinity and specific conductivity in each water sample from springs and boreholes were included. For the samples from springs the 222Rn total volume activity was estimated. For samples from selected isolated levels in the investigation boreholes some stable isotopes and TOC were estimated too. The probability of the occurrence of the hydrogeologically active fractures is higher in the case of springs which show some anomalies, such as higher values of specific discharge, temporal stable values of discharge, retarded reactions to the extreme precipitation volume, higher water temperature, higher mineralization, higher 222Rn total volume activity and higher Na/Ca ratio.