Application of organic micro-pollutants for the characterisation of two karst systems

In the presented work the occurrence of organic micro-pollutants is discussed for two karst areas with different geological characteristics and land-use patterns. Within an urban moderately karstified catchment with a large number of local input sources (e.g. contaminated sites, sewer leakages), a greater variety of micro-pollutants is found compared to a rural area. Mostly the concentrations of these compounds decrease below quantification limits before emerging at the spring and can therefore only be detected by a comprehensive network of sampling points. Springs show the presence of micro-pollutants, either recently applied in large amounts or characterized by high persistence. At the outlet of a highly karstified and consequently highly permeable aquifer readily biodegradable compounds are detected. Due to high groundwater flow velocities investigations of micro-pollutants require a highly resolved monitoring. Therefore, beside substance properties, also hydrogeological characteristics affect the spectrum of detectable micro-pollutants.