**Acknowledgements**

This study was part of the Transregional Collaborative Research Centre 38 (CRC/TR 38), which was financially supported by the Deutsche Forschungsgemeinschaft (DFG, Bonn). The monitoring was funded by the Brandenburg University of Technology (BTU) and the Brandenburg Ministry of Science, Research, and Culture (MWFK, Potsdam). The authors thank Vattenfall Europe Mining AG for providing the research site and the many helping hands at the BTU contributing to the field and lab work.
