T2-Geophysics: A Technology Transfer Program for Facilitating Effective use of Geophysics for Environmental Characterization and Monitoring at DoD Sites

Dr. Lee Slater | Rutgers University-Newark

ER-201567-T2

Objectives of the Demonstration

This project had two broad objectives: (1) to broaden the effective deployment of geophysical technologies to achieve DoD’s environmental performance goals and to reduce costs and timelines to resolve environmental issues at DoD sites resulting from novel technology transfer (T2) on geophysical technologies; and (2) to develop effective T2 activities that overcome the limitations of standard ESTCP documents (reports, protocols and guidance documents) and are more applicable for transferring the key information needed on geophysical technology performance by managers and decision makers involved in stewardship of DoD sites.

ER-201567-T2 graphic

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Technology Description

This project’s approach to novel technology transfer combined (1) training workshops delivered to site remediation professionals, (2) video documentation of hands-on training activities, (3) webinars focused on concepts and decision making, with interactive question-and-answer periods, (4) an ‘Ask the Geophysicist’ forum and (5) an Excel based tool to promote the effective use of electrical imaging methods. The approach capitalized on web services for online dissemination of training products, along with social media for community building.

Geophysical technologies that have been successfully demonstrated through SERDP and ESTCP funding were primarily targeted along with techniques that are sufficiently mature to result in high impact return on technology transfer investment. The focus of the technology transfer was on geophysical methods that (1) have the potential for a high return on information content relating to remediation problems at DoD sites, (2) are based on commercially available instrumentation, and (3) are within the toolkit of an established geophysical services contractor. The electrical resistivity imaging method is one of the most widely used geophysical technologies at DoD sites, so the efforts paid particular attention to this geophysical method.

Borehole geophysical logging provided profiles of geophysical properties of the rock mass local to boreholes. These geophysical properties were sensitive to the physical properties of the rock controlling fluid flow and solute transport. Certain geophysical properties determined from borehole logging were also sensitive to the chemical characteristics of the pore (and fracture) filling fluids. Some borehole logging methods were already well utilized at remediation sites, but the toolkit of borehole logging probes has grown considerably in recent years. Technology transfer efforts enhanced the visibility of these new probes (and the information content they provide) amongst RPMs. In addition to conventional logging tools, this technology transfer focused on a promising emerging logging method known as nuclear magnetic resonance (NMR).

In regards to electrical imaging, dramatic developments in geophysical characterization and monitoring technologies have occurred over the last decade, driven by increased computing power, modeling advancements and instrumentation permitting rapid acquisition of large datasets. Consequently, it is now possible to generate high resolution 3D images of the variations in the geophysical properties of the subsurface or away from boreholes in a manner akin to the field of medical tomography. Acquisition of time-lapse geophysical data offers the potential to monitor dynamic subsurface processes. However, these images are subject to misinterpretation by the non-expert end user. Technology transfer efforts on this project specifically addressed the dangers of misinterpretation of such information.

Specific Products

1. Webinars

 “Geophysics 101 – Realistic Expectations for Geophysics When Used for Site Characterization and Remediation Monitoring” was presented in two 90-minute webinars, each webinar on a different date.  Key information was focused on the general capabilities and limitations of geophysics for remediation studies, pros and cons of geophysics versus direct invasive measurements, strategies to help decide when geophysical methods should be utilized, and decision-based tools to support cost-effective and appropriate use of geophysical technologies at contaminated sites.  Each webinar was presented in two sections, with a question and answer session in between sections and at the end of the webinar.

Part 1, presented by Lee Slater and Judy Robinson, occurred on June 30, 2016.  This webinar focused on the fundamentals of geophysics and detailing geophysical tomography (imaging) tools. 

Part 2, presented by Fred Day-Lewis and Carole Johnson, occurred on July 28, 2016. This webinar focused on borehole geophysical logging, geophysical characterization of hydrogeological frameworks at remediation sites and geophysical monitoring of remedial treatments.

2. Videos

a. The Fractured Rock Geophysical Toolbox Method Selection Tool (FRGT-MST) is an Excel-based tool for identification of geophysical methods most likely to be appropriate for project goals and site conditions.

The FRGT-MST equips remediation professionals with a tool to understand what is likely to be realistic and cost effective when contracting geophysical services, and reducing applications of geophysics with unrealistic objectives or where methods are likely to fail.

b. Scenario Evaluator for Electrical Resistivity (SEER) Survey Pre-Modeling Tool

SEER is a quick and simple Excel-based decision support tool that practitioners can use to assess the likely outcome of using two-dimensional (2D) electrical resistivity imaging for site characterization and remediation monitoring. SEER features a graphical user interface (GUI) that allows users to manipulate a resistivity model and instantly view how that model would likely be interpreted by an electrical resistivity imaging survey. The SEER tool is intended for use by practitioners who wish to determine the value of including electrical resistivity imaging to achieve project goals, and is designed to have broad utility in industry, teaching, and research. A comprehensive help menu is provided which yields a more in-depth review of theory and application of the method.  In particular, the implications of altering editable parameters in SEER (e.g. electrode spacing, survey configuration and noise levels) is discussed.

SEER can be downloaded free of cost and is public domain property, such that it can be copied, modified, distributed and used for commercial purposes without permission.

c.  Borehole Nuclear Magnetic Resonance (NMR): a valuable tool for environmental site management

Nuclear Magnetic Resonance (NMR) is a quantitative geophysical method that can be used to make in situ assessments of porosity, water content, mobile and immobile water fraction, and estimates of permeability. While borehole NMR is commonly used in the oil and gas industry, it is only recently that NMR tools have been designed for use in small-diameter boreholes that are typically used in groundwater studies. This video presents an overview of borehole NMR and example applications for environmental site management.

3.  Ask a geophysicist forum  http://askageophysicist.org/ and  http://askageophysicist.net/  

The AskaGeophysicist forum is hosted through Proboard forum service and provides a means for continuous Q&A between geophysics experts and remediation professionals.  Forum posts provide an opportunity for Q&A based around a specific question related to application of geophysical technologies for site investigation. The project PIs are directly notified when a post has been made, which encourages a timely response to participants and/or a review of postings.

The forum is broken into three boards. One board hosts an extensive range of resources that remediation professionals can use to learn more about best practices for applying geophysics at contaminated sites. This section is used as a repository for all T2 activities outlined in this final report.  A second board covers the range of geophysical methods whereas the third board deals with common applications.  Users are encouraged to register, but it is not required to make a posting.  Any user can create or answer a posting.

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Demonstration Results

See products and publications below.

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Implementation Issues

T2-Geophysics has enormous potential benefits for DoD that can result from both informed use and informed rejection of geophysics in different projects where methods are, respectively, recommended or contraindicated. Extensive cost savings to DoD will ultimately result from early rejection of methods judged to be ineffective based on decision support training provided by the family of T2-Geophysics modules. Cost savings will result where geophysics is used, through implementation of appropriate methods given the survey objectives, realistic expectations of geophysical information and informed interpretation of geophysical results.

T2-Geophysics has enormous potential benefits for DoD that can result from both informed use and informed rejection of geophysics in different projects where methods are, respectively, recommended or contraindicated. Extensive cost savings to DoD will ultimately result from early rejection of methods judged to be ineffective based on decision support training provided by the family of T2-Geophysics modules. Cost savings will result where geophysics is used, through implementation of appropriate methods given the survey objectives, realistic expectations of geophysical information and informed interpretation of geophysical results.

A widespread technology transfer effort on the application of geophysics at contaminated sites would ultimately eliminate many of the problems contributing to the mixed reputation of geophysics in the environmental community. Failure rates would decrease dramatically if, prior to field investigations, RPMs could make informed decisions about the likely worth and return of geophysical techniques for a specific application at a particular site. T2 products developed under this project help arm the current and next generation of RPMs with enhanced abilities and tools to evaluate proposals for geophysical investigations, ask critical questions about such proposals, and interpret results of geophysical investigations. (Completed: 2018)

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Publications

Terry, N., F.D. Day‐Lewis, J. L. Robinson, L.D. Slater, K. Halford, A. Binley, J.W. Lane, and D. Werkema. 2017. Scenario Evaluator for Electrical Resistivity Survey Pre‐modeling Tool. Groundwater, 55(6):885-890.

Day-Lewis, F.D., L.D. Slater, J. Robinson, C.D. Johnson, N. Terry, and D. Werkema. 2017. An Overview of Geophysical Technologies Appropriate for Characterization and Monitoring at Fractured-Rock Sites. Journal of Environmental Management, 204:709-720.

L. Slater, F. Day-Lewis, J. Robinson; N. Terry. Novel Technology Transfer (T2) Activities for Geophysical Technologies Applied at Chlorinated Solvent Contaminated Sites, SERDP/ESTCP Symposium, 344, November 27-30, 2017. ( https://www.sciencedirect.com/science/article/pii/S030147971730381X)

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