1. School of Earth, Atmosphere and Environment, Monash University Clayton, Victoria 3800 Australia
2. The National Centre for Groundwater Research and Training, Flinders University 326 Sturt Rd Adelaide, South Australia 5001 Australia
3. U. S. Geological Survey, Office of Groundwater, Branch of Geophysics 11 Sherman Place Unit 5015 Storrs CT 06269
4. Department of Earth Sciences, Syracuse University 204 Heroy Geology Laboratory Syracuse NY 13244
5. Maine Geological Survey 93 State House Station Augusta ME 04333
6. Earth and Planetary Sciences, McGill University, 3450 University Street, Montreal, Quebec, Canada H3A 0E8