Lately in the catchment area of Jadro and Ţrnovnica springs was constructed a lot of commercial buildings for various purposes, increased the number of residential buildings and agricultural areas that were previously untreated, have begun to intensively cultivate. All this can have a negative impact on water quality. Therefore greater attention was given to the protection of groundwater from this basin. As a consequence, there have been conducted (and still are carried out) a number of geological, hydrogeological, hydrological, hydrogeochemical and other research of all parts of the karst aquifer system. Based on the available data on measurements of water quality, the quality of spring water was evaluated and categorized and analyzed the trend in the indicators of pollution. It was found that the biggest problem in the reference catchment is often microbiological contamination, and the occasional heavy metal concentrations which can not accurately determine the cause. The first step in improving the current situation is locate potential sources of pollution, so that could be accessed by their sanitization. This paper presents an hazard analysis proposed by project COST 620, of which the final result is classified hazard map, which serves as one of the bases in the process of assessing the risk of groundwater contamination. The improvement of the water quality can be expected only by controlled separation of all potential and active pollutants and by the constant percolation of the contaminated water in the drainage area of the springs.