Bank filtration and artificial groundwaterecharge are important, effective and cheap techniques for surface water treatment and removal of microbes, inorganic and some organic contaminants. Nevertheless, mechanisms of the removal of impurities and of the chemical reactions of the water components have not been understood sufficiently and are therefore subject of this research project. The interdisciplinary project of the Berlin Centre of Competence for Water (KWB gGmbH) entitled NASRI (Natural and Artificial Systems for Recharge and Infiltration) concentrates among other topics also on nicroorganisms and trace organic substances frequently detected in surface waters.