1. School of Agriculture, Food and Wine, University of Adelaide; Prescott Building Glen Osmond SA 5064 Australia
2. CSIRO Land and Water; Adelaide Laboratory; PMB 2 Glen Osmond SA 5064 Australia
3. USEPA; Groundwater and Ecosystems Restoration Res.; Ada OK 74820
4. Soil and Land Systems, School of Earth and Environmental Sciences, University of Adelaide; Glen Osmond SA 5064 Australia