My general field of interest is low-temperature aqueous geochemistry, encompassing problems in water-rock interactions, kinetics of geochemical reactions, and evolution of groundwater chemistry in various hydrogeological environments. My research includes elements of field studies, laboratory experimentation, and theoretical modeling. One research project is focused on the fate and transport of bacteria and organic contaminants in groundwater and is a collaborative effort with Messrs. Mills and Hornberger. We are currently investigating the effects of geological heterogeneity in a Coastal Plain deposit on the transport of reactive solutes and bacteria. Another project underway is focused on the fundamental geochemical, hydrological, and microbiological processes influencing the environmental fate of agricultural chemicals in a watershed in Virginia underlain by deeply weathered, fractured limestone. In this project, the colloid-facilitated transport of nutrients and herbicides is being investigated in the unsaturated soil zone. A new project in Florida will use hydrogeological and geochemical models to gain insight into groundwater flow paths and residence times.