My research interests are in groundwater hydrology, including groundwater contamination, the flow of immiscible organics in porous media, vadose zone processes and the interaction of groundwater and surface water. The National Science Foundation, the U.S. Geological Survey, the U.S. Department of Agriculture and the U. S. Air Force have funded my work. I have served as a consultant to a number of companies. I was part of a vadose zone monitoring field project to estimate the total volume of diluent at the Guadalupe Oil Field, the largest oil spill in U.S. history. Recently, I have served as a reviewer of long term plans for closure of Area G at Los Alamos National Laboratory in New Mexico. This area is the primary low-level radioactive waste site at LANL and will be the first area closed at the lab. In addition, I was a member of the National Academy of Sciences committee on groundwater contamination at Los Alamos. I am a registered Professional Engineer in the State of Colorado.