Until 1985, untreated wastewater was irrigated directly onto the soils of several sewage farms in and near Berlin/Germany, leading to a contamination of soils and groundwater.
The flow direction of groundwater in Berlin is generally directed towards the glacial valley, where raw water subsequently used for drinking water production is collected from wells abstracting bank filtrate from adjacent lake-type surface waters. Hence, persistent organic pollutants originating from former sewage irrigation may potentially reach drinking water wells.
Since 1990 various projects have dealt with the contaminant loads of soils and groundwater from several former irrigation farms. Groundwater below a decommissioned sewage farm was found to be heavily polluted with a number of anthropogenic organic compounds such as pesticides, AOX and phenols.
The objective of this project is to evaluate the adverse effects of landside groundwater on the raw water quality with a special focus on the decommissioned sewage irrigation fields. The extent of existing contaminations will be assessed, in particular where sewage irrigation has been practised for decades. For this purpose, an analytical method for relevant organic compounds will be developed. Target analytes will be selected via gas chromatography–mass spectrometry (GC-MS) screenings. The assessment of the relevancy of the organic substances will be carried out considering both hydrodynamical and hydrochemical conditions of the groundwater as well as the history of sewage farming. Groundwater-flow models (FEFLOW-simulator) are available as an instrument for hydrodynamic scenario analyses.
The newly developed analytical method will be used for extensive groundwater investigations. In addition, laboratory experiments will be conducted to study the (biological) degradation of selected compounds.
Ulrike Hass, Dr. Gudrun Massmann, Prof. Dr. Asaf Pekdeger, Dr. Thomas Taute
(all FU-Berlin), Dr. Uwe Dünnbier (BWB)