1. Centre for Water and Waste Technology, University of New South Wales, Sydney, NSW 2052, Australia E-mail: h.coleman@unsw.edu.au; s.khan@unsw.edu.au; r.stuetz@unsw.edu.au
2. MidCoast Water, PO Box 671, Taree, NSW 2430, Australia E-mail: graeme.watkins@midcoastwater.com.au