Geophysics for Mapping Subsurface Remediation

Project Team

Team Members:

  • Laís Trento

Successful remediation of DNAPL-contaminated sites requires adequate characterization of the volume and extent of the DNAPL source zone. Geo-electrical techniques, such as electrical resistivity tomography (ERT), self potential (SP) and ground penetrating radar (GPR) can be sensitive to subsurface electrical changes caused by the presence and/or movement of contaminants. Despite the potential of these methods and the success of controlled field and laboratory experiments, field application of ERT, SP and GPR to locate or map contaminant source zones is not extensively practiced.

Former PhD student, Dr. Chris Power, performing an electroresistivity survey.

Initially, our research has been the exploration of this topic in a theoretical and computer modeling framework. The unique coupling and development of hydrogeological and geophysical numerical models, namely DNAPL-GPR (Wilson et al., 2009) and DNAPL-ERT (Power et al., 2013), have provided a methodology for valuable and realistic exploratory simulations and a framework for developing and testing new ERT, SP and GPR quantitative interpretation tools. In addition, to fully compliment and put this ‘new’ theoretical knowledge into practice, this research group is collaborating with its industrial partner, Geosyntec Consultants, with the goal of developing, evaluating and optimizing geo-electrical techniques for site implementation. The project includes the development of advanced numerical tools, fundamental advances in knowledge in an emerging, cross-disciplinary area, and real applicability to current field practice with future commercial potential.

Coupled DNAPL-ERT model to simulate the release and subsequent monitoring of contaminant spill scenarios (Power et al., 2013)

Key references

Power C., Gerhard, J.I., Tsourlos, P. and Giannopoulos, A. (2013) A new coupled model for simulating the mapping of dense nonaqueous phase liquids using electrical resistivity tomography. Geophysics, 78(4), EN1-EN15, doi: 10.1190/geo2012-0395.1.

Wilson, V.C, Power, C., Grant, G.P., Gerhard, J.I. and Giannopoulos, A. (2009) DNAPL mapping by ground penetrating radar examined via numerical simulation. Journal of Applied Geophysics. 69 (3-4): 140-149.

C. Power ,J.I. Gerhard, P. Tsourlos, P. Soupios, K. Simyrdanis, M. Karaoulis, 2015.Improved time-lapse electrical resistivity tomography monitoring of dense non-aqueous phase liquids with surface-to-horizontal borehole arrays . Journal of Applied Geophysics, 112, 1-13.

C. Power ,J.I. Gerhard, M. Karaoulis, P. Tsourlos, A. Giannopoulos, 2014. Evaluating four-dimensional time-lapse electrical resistivity tomography for monitoring DNAPL source zone remediation. Journal of Contaminant Hydrology, 162-163, 27-46.

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