The following work was conducted as part of the NASRI (Natural and Artificial Systems for Recharge and Infiltration) Project of the KompetenzZentrum Wasser Berlin, funded by the Berliner Wasser Betriebe and Veolia Water. The general aim of the Project was to gain a better understanding of the interacting physical, chemical and biological processes that affect the water quality changes during subsurface passage in riverbank filtration and ponded infiltration systems in the City of Berlin, Germany. The project was a cooperation of the Berliner Wasser Betriebe, Free University Berlin, Technical University Berlin, German Federal Environmental Agency and the Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin. The research described in this thesis was carried out at the Leibniz Institute of Freshwater Ecology and Inland Fisheries in close collaboration with the Free University Berlin, CSIRO Land and Water, South Australia and the University of Utrecht, The Netherlands.