Denis LeBlanc is a hydrologist with the U.S. Geological Survey in Northborough, Mass. He is project leader of the USGS Cape Cod Toxic Substances Hydrology Research Site and also coordinates the USGS technical assistance to the groundwater cleanup at the Joint Base Cape Cod military reservation. Denis received a B.S. in Hydrology from the University of New Hampshire and an M.S. in Civil and Environmental Engineering from MIT. He joined the USGS in 1975, and since then has been involved in many studies of the groundwater resources of Cape Cod.