ABSTRACT: Water source Podzámčok is a part of aqueduct of Pohronie group. It comprises 5 pumping wells HGN 2-6 and observation well HGN-1. Groundwater reserves are primarily recharged by infiltration of atmospheric precipitation and by flow from Štiavnica Mountains. The type of ground water is determined as atmospherogenic, petrogenic and silicatogenic. The sources of pollution in studied area are intensive agricultural activity, roads and wild dumps of municipal waste. There is no communication between the surface water and groundwater, the pollution comes into the ground water trough percolation from surface. Quality of groundwater is very high. In the water there are very low concentrations of undesirable components. The only long lasting problem is the microbiological pollution of water.