Dr. Lee Slater
Dr. Slater is a recognized expert in environmental geophysics specializing in electrical imaging studies. He is the author of 60 peer-reviewed publications in near surface geophysics, he has served as principal investigator on numerous geophysics-based research awards from federal sources (National Science Foundation, Dept. of Energy, United States Geological Survey) and currently serves as the Chair of the Near Surface Geophysics Focus Group of the American Geophysical Union (AGU). He provides a range of near-surface (environmental) geophysics consulting services to state and local government, as well as the private sector (resume available on request).

Dr. Dimitrios Ntarlagiannis
Dr. Ntarlagiannis is a geophysicist specializing in near surface applications of electrical methods. He is the author of 10 peer-reviewed publications in near surface geophysics and has numerous presentations in national and international conferences. For the last few years he provides a range of geophysical consulting services in the private sector (resume available on request).

We specialize in conducting two of the most useful geophysical techniques for near surface studies:
Ground Penetrating Radar (GPR) is a geophysical tool ideal for rapid subsurface characterization for environmental and geotechnical projects. We are equipped with state of the art GPR systems and we offer a wide selection of antennae frequencies (i.e. subsurface remote sensors), ranging from 1.2 GHz to 50 MHz, that allow us to perform virtually any environmental / geotechnical project. Our unique expertise comprise many years of GPR experience (academic research, government projects, private sector consultancies) and sound theoretical training. We use the most advanced software for data processing and data inversions. Finally, we can offer specialized GPR applications, such as cross-hole GPR tomography or time lapse GPR monitoring when needed.

Electrical imaging (Electrical Resistivity Tomography) is a technology increasingly used in recent years as a result of advances in both data acquisition instruments and inversion software. We have unique expertise in the design, instrumentation deployment and data processing associated with electrical imaging survey. In addition to conventional surface imaging, we have the expertise to conduct more specialized surveys such as cross-borehole, borehole to surface and waterborne/marine surveys. We are also experts in the induced polarization technique (an often overlooked measurement that can be collected at little additional cost by most modern electrical imaging instrumentation) and time-lapse (4D) monitoring surveys.

Drs. Slater and Ntarlagiannis organize intensive (2-day) short courses on Ground Penetrating Radar and Electrical Resistivity Imaging through Rutgers University. These courses specifically cater to environmental engineers and consultants needing to collect, and/or interpret, geophysical datasets. These classes qualify for Continuous Education credit through the Rutgers educational programs. For more information see: http://continuoused.rutgers.edu/

Environmental site characterization methods have evolved from simple drill-and-sample routines into more sophisticated evaluations of increasingly complex environmental problems. Geophysical techniques permit rapid, non-invasive subsurface characterization and monitoring. Environmental problems frequently addressed with geophysics include:

• locating groundwater contamination and migration
• locating abandoned/buried drums, oil/gas tanks, wells and well pipes, utility lines, drainage lines, etc.
• defining subsurface lithology/stratigraphy
• locating cavities and abandoned mine shafts
• delineating archeological features

We are equipped to apply electrical imaging and ground penetrating radar in a diverse range of environments.

Example of a 2D resistivity/induced polarization survey to image the infill of the Keegan Landfill, Lyndhurst, NJ. [a] resistivity section [b] induced polarization section [c] aerial photo of Keegan Landfill showing survey line in red. The infill is imaged as n 5-7 m thick conductive and polarization layer, increasing in thickness to the east.

Ground penetrating radar
• Two or three dimensional surface ground penetrating radar surveys
• Wide range of geotechnical and environmental applications including detection of buried metals, utilities, USTs, cavity/mine detection, lithologic mapping – delineation of buried structures and foundation – borehole / trench clearance.
• Specialized applications, such as cross-hole GPR tomography or time lapse GPR monitoring, are also available

Electrical resistivity imaging/tomography (ERT)
• Two or three dimensional electrical imaging surveys using electrodes on the surface and/or in boreholes
• Applications: contaminant delineation and monitoring, monitoring groundwater quality, cavity/mine shaft detection, lithological imaging, landfill studies

Induced polarization imaging/tomography
• Two dimensional induced polarizaton surveys using electrodes on the surface
• Applications: detection of buried metals, lithologic imaging, defining clay layers, landfill studies

Time-lapse electrical imaging
• Electrical imaging of dynamic (4D) subsurface processes
• Applications: monitoring contaminant migration, water quality, moisture content

Waterborne/marine resistivity imaging
• Continuous marine resistivity imaging for imaging shallow estuaries and river corridors

Electrical image of a permeable reactive barrier (PRB) constructed of zero-valent iron. The barrier is resolved as a highly conductive feature due to the presence of the iron (from Slater and Binley, 2006, Geophysics)