ABSTRACT
Bank filtration has been used for drinking water supply in Berlin for more than one hundred years. Detailed investigations were done in order to assess the sustainability of bank filtration. Chemical changes along the flow path are being studied at test fields situated near the discharging wells of the water supply. Sediment cores from the river bottom in the direct infiltration zone were taken by different sampling techniques. A frozen-core-drilling technique was used to collect depth-related samples for geochemical analysis of the sediment and the pore water. Interactions between sediment and infiltration water were described. Additionally, hydraulic tests were used to estimate the clogging effects of the bank sediments. These results could be used to estimate the vertical leakage through the sediment into the groundwater. We combined them with tracer studies to estimate the infiltration time. In the end, a 3-dimensional numerical model was developed to differentiate the flow paths to the abstraction well.
