1. Department of Water Resources and Drinking Water; Eawag; Swiss Federal Institute of Aquatic Science and Technology; Überlandstrasse 133 CH-8600 Dübendorf Switzerland
2. Department of Environmental Systems Science; Institute of Biogeochemistry and Pollution Dynamics; ETH Zurich; Universitätstrasse 16 CH-8092 Zürich Switzerland
3. Department of Biology and Global Institute for Water Security; University of Saskatchewan; 112 Science Place Saskatoon SK SN7 5E3 Canada
4. City of Zurich Water Supply; Hardhof 9, P.O. Box 1179 CH-8021 Zürich Switzerland