1. Professor, Pennine Water Group, Dept. of Civil and Structural Engineering, Univ. of Sheffield, Mappin St., Sheffield S1 3JD, U.K.
2. Senior Lecturer, Urban Water Technology Centre, Univ. of Abertay Dundee, Bell St., Dundee DD1 1HG, U.K. (corresponding author). E-mail: d.blackwood@abertay.ac.uk
3. Professor, Centre for Water Systems, Univ. of Exeter, North Park Rd., Exeter EX4 4QF, U.K.
4. Professor, School of the Built Environment, Heriot-Watt Univ., Edinburgh EH14 4AS, U.K.
5. Head of Civil Engineering, School of Science and the Environment, Coventry Univ., Coventry CV1 5FB, U.K.