Context

Persistent trace substances are emitted into surface waters via WWTPs or diffuse pollution and thus pose a threat to drinking water production from these resources. The factors influencing the risk level are e.g. the production output and application quantities, solubility, degradability, sorption behaviour and toxicity of the actual substance and its metabolites.

Known organic trace substances, for which it has not yet been sufficiently clarified whether they pose a risk to drinking water production in Berlin, are, for instance, complexing agents, perfluorinated tensids (PFC: perfluorinated compounds) and the pesticides Glyphosate and Isoproturone. Furthermore, transferable elimination rates are not available yet.

• EDTA (ethylendiamintetraacetic acid), known as a highly persisting complexing agent, has increasingly been substituted in Germany by other substances such as DTPA (diethylentriaminpentaacetic acid) or PDTA (propylenediamintetraacetic acid). Their occurence in the Berlin area and their environmental persistence are only fragmentarily reported so far.

• Perfluorinated compounds (PFC) are frequently used for the surface treatment of textiles (e.g. water proofing sprays) and are additives for fire extinguishing foams. They can be detected worldwide in both the aquatic environment and biota. As to the best known representatives – PFOA (perfluorooctance acid) and PFOS (perfluorooctance sulfonate) – a high mobility has been observed; they are however, increasingly substituted by shorter chained PFC.

• Glyphosate and Isoproturone belong to the most common pesticides worldwide. Their relevance for the Berlin region is based on the fact that both substances have been detected in Brandenburg’s surrounding water bodies and are used in gardens and allotments.

Objective

The project aims at assessing the potential risk arising from the occurrence of complexing agents, selected pesticides and PFC in surface waters used for drinking water production through bank filtration and artificial recharge.