Dr. Jonathan Johnson has 15 years of experience in quantitative analysis of hydrogeology in more than 20 states and several foreign countries. Jon has conducted and managed numerical modeling and quantitative hydrogeologic analysis at sites around the world, including 10 superfund sites in 6 USEPA regions. He has extensive project experience evaluating water supplies, conducting contaminant transport modeling and providing support for multi-million dollar litigation projects. His expertise includes hydrologic and geologic investigation and interpretation, fate and transport in groundwater and the unsaturated zone, geochemistry and natural attenuation of chemicals in groundwater, wetland hydrogeology, surface water-groundwater interaction, artificial groundwater recharge, and water resources evaluation. He combines a thorough understanding of chemistry, hydrology, and the geological setting to identify key elements often overlooked by traditional site investigations. Jon has authored expert witness reports, and has published and been an invited conference speaker on subjects including modeling of natural attenuation processes and dissolution of non-aqueous-phase liquids. Jon obtained his PhD in civil engineering at Princeton University, where his graduate work included both numerical modeling and laboratory analysis. His undergraduate work was completed in geological engineering at the Missouri University of Science and Technology. He worked for the United States Geological Survey (USGS) prior to his career in environmental consulting.