By Andrew J.B. Cohen, 1995.
This guidance report describes, compares, and provides recommendations for using and integrating different characterization methodologies, including surface and subsurface fracture detection and measurement, well drilling, pumping, injection and tracer tests, geophysical logging, borehole flow logging, seismic imaging techniques, and computer visualization techniques.
“I used this as a regulator in Pennsylvania years back. One of the tools of the trade.” – Former regulator, Pennsylvania Department of Environmental Protection
“The report remains a valuable reference for environmental agencies and consultants tackling contamination in complex geological settings.” – Bob Cleary, Ph.D., Princeton Groundwater, Inc.
Overview:
A field site was developed in the foothills of the Sierra Nevada, California, to develop and test a multi-disciplinary approach to characterize groundwater flow and transport in fractured rocks. Nine boreholes were drilled into the granitic bedrock, and a wide variety of new and traditional tools were applied to characterize the subsurface. This study incorporated and compared various characterization methodologies, including surface and subsurface fracture detection and measurement, well drilling, pumping, injection and tracer tests, geophysical logging, borehole flow logging, seismic imaging techniques, and computer visualization techniques. The hydrogeologic structure and properties of the field site were deduced by integrating results from these diverse geologic, geophysical, hydrologic, and other investigative methods.
The findings are synthesized in this report, which is structured as a guidebook, to explain the application of both new and traditional technologies; provide recommendations on how to effectively use, integrate, and analyze field data; and offer comparisons of the advantages and limitations of different methods. The results highlight how integrating multiple approaches enhances the understanding of fractured rock hydrogeology, aiding in more accurate groundwater flow and contaminant transport assessments.