1976-1980 Post-doctoral Fellow and Research Scientist, University of New Hampshire
1980-1986 Assistant Professor, Department of Earth Sciences, University of New Hampshire
1986-1990 Associate Professor, Department of Earth Sciences, University of New Hampshire
1990-1993 Professor & Director of Hydrologic Sciences Program, University of Nevada, Reno
1993-1999 Loper Professor of Environmental Geology, Department of Geology, University of Alabama