About 50% of the territory of the Republic of Croatia is from the hydrogeological point of view characterized as karst. Conductors in the karst are very irregularly distributed and this is the reason why the flow and transport modelling is extremely complex and unreliable. The occurrence of pollutants in karst aquifers may be the result of increased agricultural activity, permeable septic tanks, wastewater from settlements and industry, as well as some other sources of pollutants. Pollution contributes to reducing the amount of water suitable for water supply needs. In order to prevent the spread of pollution, research is being conducted with the aim of determining the position of the pollution source and its remediation in situ. In this context, numerical models which process the results of hydrogeological measurements collected during pumping tests on exploitation wells are increasingly used. This paper presents an integral test pumping test applied at the Bokanjac - Poličnik site, which was conducted as part of a comprehensive hydrogeological survey of aquifers. The test consists of long-term pumping, measurements of groundwater level and simultaneous systematic sampling of captured water on which appropriate chemical analyzes are performed.