Metaller i Stockholms grundvatten : En studie om grundvattnets påverkan på ekosystem i ytvattnet

Sammanfattning: As a consequence of the urbanization the groundwater in the area of Stockholm has been polluted since many years. The quality of the groundwater affects the surface water providing the inhabitants of the city with drinking water. To reach the environmental goals concerning groundwater further knowledge about the impact on surface water caused by polluted groundwater steams is necessary. Accordingly, the purpose of this study is to contribute with further information about the impact on surface water ecosystem in the discharge area of groundwater streams caused by elevated contents of metals in groundwater. A survey commissioned by Miljöförvaltningen Stockholmsstad (the municipal environmental administration) constitutes a basis for this study. The metals presented in this report are relevant due to their toxic characteristics and by their frequent occurrence in elevated content in groundwater samples. The groundwater content of these 9 metals determined which geographical positions would be of interest when evaluating potential ecosystem effects. The result indicates varying consequences for the ecosystems in the studied areas, but most of them seem to be at risk of being negatively affected. Further studies are needed to confirm our results and also to provide with more information about groundwater quality generally.