1. Department of Urban Water Management, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Ueberlandstrasse 133, Duebendorf, Switzerland (E-mail: michael.burkhardt@eawag.ch; thomas.kupper@eawag.ch; markus.boller@eawag.ch)
2. Laboratory for Road Engineering/Sealing Components and Laboratory for Analytical Chemistry, Swiss Federal Institute for Materials Science and Technology (Empa), Ueberlandstrasse 129, Duebendorf, Switzerland (E-mail: sivotha.hean@empa.ch; regula.haag@empa.ch; peter.schmid@empa.ch; martin.kohler@empa.ch)