1. Geotechnics and Environment, Norwegian Geotechnical Institute (NGI), Oslo 0855, Norway
2. Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim 7010, Norway
3. Department of Geosciences, University of Oslo (UiO), Oslo 0855, Norway
4. DMR Miljø og Geoteknikk, Trondheim, Norway
5. Norwegian Institute for Water Research (NIVA), Oslo 0349, Norway