Stephen Cauller has been a hydrologist with the U.S. Geological Survey for nearly 30 years. He earned a B.S. in Earth Science from West Chester University and a M.S. in Geology from Lehigh University. He has directed numerous groundwater studies in the coastal plain of New Jersey where his work has involved groundwater levels and mapping, chloride concentrations in groundwater, hydrogeologic framework analysis, water quality summaries, 3D groundwater flow model development, groundwater particle tracking, and the advective transport of nitrogen in groundwater. He is also the GIS Specialist in the NJ Water Science Center where he manages their geospatial database and assists coworkers with the use of geographical information systems software.