Tetsu Tokunaga is a Senior Scientist in the Energy Geosciences Division of Lawrence Berkeley National Laboratory, studying the physicochemical basis of environmental transport processes. While conducting his graduate studies on gas diffusion in porous media at the University of California, Berkeley, he began working at LBNL on problems of unsaturated flow and transport from uranium mill tailings, and on reactive transport of selenium in contaminated wetland (Kesterson Reservoir). Upon graduation, he continued at LBNL conducting laboratory and field based studies on soil/geologic transport problems. In addition to his research at LBNL, he taught soil physics courses at the University of California, Berkeley. He currently has over 80 publications in peer-reviewed journals.