1. Sanitary Engineering, Delft University of Technology, P.O. Box 5048, 2600 GA, Delft, The Netherlands
2. DHV BV, P.O. Box 484, 3800 AL, Amersfoort, The Netherlands
3. Delft Center for Systems and Control, Mekelweg 2, 2628 CD, Delft, The Netherlands
4. Waternet, Provincialeweg 21, 1108 AA, Amsterdam, The Netherlands