Hydrogeology Journal

, Volume 15, Issue 5, pp 877–890 | Cite as

Electrical resistivity imaging of conductive plume dilution in fractured rock

  • Robin E. Nimmer
  • James L. Osiensky
  • Andrew M. Binley
  • Kenneth F. Sprenke
  • Barbara C. Williams
Paper

Abstract

Electrical resistance tomography (ERT) was used to monitor a conductive plume dilution experiment that was conducted in fractured basalt in order to assess its applications in this type of fractured-rock environment. Tap water was injected into an injection well for 34 days to dilute a pre-existing potassium chloride (KCl) plume at a site in Idaho, USA. No further fluids were introduced artificially during a 62-day monitoring period. Both surface ERT and cross-borehole ERT were used to monitor dilution and displacement of the plume. A square grid of land-surface electrodes was used with the surface ERT. Three-dimensional images of surface ERT delineated areas of increased and decreased resistivities. Increasing resistivities are attributed to dilution/displacement of the KCl solution by tap-water invasion or the influx of seasonal recharge. Decreasing resistivities resulted from redistribution of residual KCl solution. Cross-borehole ERT was conducted between the injection well and each of seven surrounding monitoring wells. Polar plots of the injection-well resistivity data in the direction of each monitoring well delineate specific locations where tap water seeped from the injection well via preferential flow paths determined by time-dependent resistivity increases. Monitoring-well data indicate locations of clustered and isolated regions of resistivity changes.

Keywords

Fractured rocks Basalt Tracer tests Electrical resistance tomography Plume 

Résumé

La tomographie de résistivité électrique (ERT en anglais) a été utilisée pour surveiller une expérience de dilution d’un panache conducteur dans du basalte fracturé, afin d’évaluer son application dans ce type d’environnement à roches fracturées. De l’eau du réseau d’alimentation a été injectée dans un puits d’injection pendant 34 jours pour diluer un panache de chlorure de potassium (KCl) préexistant sur un site localisé dans l’Idaho aux Etats-Unis. Aucun autre fluide n’a été artificiellement introduit pendant une période de surveillance de 62 jours. L’ERT de surface et l’ERT entre puits ont toutes deux été utilisées pour contrôler la dilution et le déplacement du panache. Un maillage carré d’électrodes de surface a été utilisé pour l’ERT de surface. Des images tridimensionnelles obtenues par l’ERT de surface ont délimité des zones d’augmentation et de diminution de la résistivité. Les résistivités croissantes sont expliquées par la dilution/déplacement du KCl causés par l’invasion de l’eau du réseau ou par l’arrivée de la recharge saisonnière. Les résistivités décroissantes provenaient de la redistribution de la solution de KCl résiduelle. L’ERT de puits a été effectuée entre le puits d’injection et chacun des sept puits d’observation environnants. Des graphiques polaires des données de résistivité du puits d’injection avec la direction de chaque puits de surveillance, délimitent des zones spécifiques d’infiltration de l’eau du réseau à partir du puits d’injection via des trajectoires d’écoulement préférentiel déterminées par les augmentations de la résistivité dans le temps. Les données des puits de surveillance indiquent l’emplacement des zones amassées et isolées de variation de résistivité.

Resumen

La tomografía de resistencia eléctrica (TRE) fue usada para supervisar un experimento de dilución de una pluma conductiva, que se realizó en un basalto fracturado, para evaluar sus aplicaciones en este tipo de ambiente de roca fracturada. Se inyectó agua del grifo dentro de un pozo de inyección durante 34 días, para diluir una pluma pre-existente de cloruro de potasio (KCl), en un sitio en Idaho, E.U.A. Ningún fluido adicional se introdujo artificialmente durante un período de monitoreo de 62 días. Tanto la TRE superficial, como la TRE de registro cruzado de pozo, fueron usadas para supervisar la dilución y desplazamiento de la pluma. Una malla cuadrada de electrodos de superficie se usó con la TRE superficial. Las imágenes tridimensionales de la TRE superficial delinearon las áreas de aumento y disminución de la resistividad. Se atribuyen las resistividades crecientes a la dilución/desplazamiento de la solución de KCl, por invasión del agua de grifo o por la entrada de recarga estacional. Las resistividades decrecientes fueron el resultado de la redistribución de solución de KCl residual. La TRE de registro cruzado de pozo fue ejecutada entre el pozo de inyección y cada uno de siete pozos de monitoreo circundantes. Las gráficas polare, de los datos del resistividad del pozo de inyección, en la dirección de cada uno de los pozos de monitoreo, delinean situaciones específicas dónde el agua de grifo se infiltra desde el pozo de inyección, siguiendo caminos de flujo preferenciales, determinados por los aumentos de la resistividad dependientes del tiempo. Los datos de los pozos de monitoreo indican sectores de cambios del resistividad en forma de racimo y regiones aisladas.

References

  1. Binley A, Ramirez A, Daily W (1995) Regularized image reconstruction of noisy electrical resistance tomography data. In: Bech MS et al. (eds) Process tomography. Proceedings of the 4th Workshop of the European Concerted Action on Process Tomography, Bergen, Norway, 6–8 April 1995, pp 401–410Google Scholar
  2. Bush J, Seward WP (1992) Geologic field guide to the Columbia River Basalt, northern Idaho and southeastern Washington. Idaho Geol Surv Inform Circ 49Google Scholar
  3. Chambers J, Ogilvy R, Meldrum P, Nissen J (1999) 3D resistivity imaging of buried oil- and tar-contaminated waste deposits. Eur J Environ Eng Geophys 4:3–15Google Scholar
  4. Dahlin T, Bernstone C, Loke MH (2002) Case history: a 3-D resistivity investigation of a contaminated site in Lernacken, Sweden. Geophysics 67(6):1692–1700Google Scholar
  5. Daily W, Ramirez A (1995) Electrical resistance tomography during in-situ trichloroethylene remediation at the Savannah River Site. J Appl Geophys 33:239–249CrossRefGoogle Scholar
  6. Daily W, Ramirez AL (2000) Electrical imaging of engineered hydraulic barriers. Geophysics 65(1):83–94CrossRefGoogle Scholar
  7. Daily W, Ramirez A, LaBrecque D, Nitao J (1992) Electrical resistivity tomography of vadose water movement. Water Resour Res 28(5):1429–1442CrossRefGoogle Scholar
  8. Daily W, Ramirez AL, LaBrecque D, Binley AM (1995a) Detecting leaks in hydrocarbon storage tanks using electrical resistance tomography, UCRL-JC-120547; CONF-9511130-1, p. 14, Presented at Frontiers’95, San Luis Obispo, CA, Nov. 1995Google Scholar
  9. Daily W, Ramirez A, LaBrecque D, Barber W (1995b) Electrical resistance tomography experiments at the Oregon Graduate Institute. J Appl Geophys 33:227–237CrossRefGoogle Scholar
  10. deGroot Hedlin C, Constable S (1990) Occam’s inversion to generate smooth, two-dimensional models from magnetotelluric data. Geophysics 55(12):1613–1624CrossRefGoogle Scholar
  11. Kemna A, Vanderborght J, Kulessa B, Vereecken H (2002) Imaging and characterisation of subsurface solute transport using electrical resistivity tomography (ERT) and equivalent transport models. J Hydrol 267:125–146CrossRefGoogle Scholar
  12. LaBrecque DJ, Ramirez AL, Daily WD, Binley AM, Schima SA (1996) ERT monitoring of environmental remediation processes. Measure Sci Technol 7(3):375–383CrossRefGoogle Scholar
  13. Li T (1990) Hydrogeologic characterization of a multiple aquifer fractured basalt system. PhD Thesis, University of Idaho, Moscow, ID, USAGoogle Scholar
  14. Li Y, Oldenburg DW (1992) Approximate inverse mapping in DC resistivity problems. Geophys J Int 109:343–362CrossRefGoogle Scholar
  15. Loke MH (2001) RES3DINV, 3D Resistivity and IP Inversion software, Geotomo Software, Penang, MalaysiaGoogle Scholar
  16. Loke MH, Barker RD (1996) Lease squares inversion of apparent resistivity pseudosections by a quasi-Newton method. Geophys Prospect 44(1):131–152CrossRefGoogle Scholar
  17. Lundegard PD, LaBrecque D (1995) Air sparging in a sandy aquifer (Florence, Oregon, USA): actual and apparent radius of influence. J Contam Hydrol 19(1):1–27CrossRefGoogle Scholar
  18. Nimmer RE, Osiensky JL (2002a) Using mise-à-la-masse to delineate the migration of a conductive tracer in partially saturated basalt. Environ Geosci 9(2):81–87CrossRefGoogle Scholar
  19. Nimmer RE, Osiensky JL (2002b) Direct current and self potential monitoring of an evolving plume in partially saturated fractured rock. J Hydrol 267(3–4):258–272CrossRefGoogle Scholar
  20. Ogilvy R, Meldrum P, Chambers J (1999) Imaging of industrial waste deposits and buried quarry geometry by 3-D resistivity tomography. Eur J Environ Eng Geophys 3:103–113Google Scholar
  21. Park S (1998) Fluid migration in the vadose zone from 3-D inversion of resistivity monitoring data. Geophysics 63(1):41–51CrossRefGoogle Scholar
  22. Park SK, Van GP (1991) Inversion of pole-pole data for 3-D resistivity structure beneath arrays of electrodes. Geophysics 56(7):951–960CrossRefGoogle Scholar
  23. Provant AP (1995) Geology and Hydrogeology of the Viola and Moscow west quadrangles; Latah County, Idaho and Whitman County, Washington, MSc Thesis, University of Idaho, Moscow, ID, USAGoogle Scholar
  24. Ramirez A, Daily W, LaBrecque D, Owen E, Chesnut D (1993) Monitoring an underground steam injection process using electrical resistance tomography. Water Resour Res 29(1):73–87CrossRefGoogle Scholar
  25. Ramirez A, Daily W, Binley A, LaBrecque D, Roelant D (1996) Detection of leaks in underground storage tanks using electrical resistance methods. J Environ Eng Geophys 1(3):189–203CrossRefGoogle Scholar
  26. Sasaki Y (1992) Resolution of resistivity tomography inferred from numerical simulation. Geophys Prospect 40:453–463CrossRefGoogle Scholar
  27. Singa K, Gorelick SM (2005) Saline tracer visualized with three-dimensional electrical resistivity tomography: Field-scale spatial moment analysis. Water Resour Res 41:W05023CrossRefGoogle Scholar
  28. Slater L, Binley A (2003) Evaluation of permeable reactive barrier (PRB) integrity using electrical imaging methods. Geophysics 68(3):911–921CrossRefGoogle Scholar
  29. Slater LD, Binley A, Brown D (1997a) Electrical imaging of fractures using groundwater salinity change. Ground Water 35(3):436–442CrossRefGoogle Scholar
  30. Slater L, Zaidman MD, Binley AM, West LJ (1997b) Electrical imaging of saline tracer migration for the investigation of unsaturated zone transport mechanisms. Hydrol Earth Syst Sci 1(2):291–302CrossRefGoogle Scholar
  31. Zaidman MD, Middleton RT, West LJ, Binley AM (1999) Geophysical investigation of unsaturated zone transport in the Chalk in Yorkshire. Q J Eng Geol 32:185–198Google Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Robin E. Nimmer
    • 1
    • 4
  • James L. Osiensky
    • 2
  • Andrew M. Binley
    • 3
  • Kenneth F. Sprenke
    • 2
  • Barbara C. Williams
    • 4
  1. 1.Hydrology Program, Department of Geological SciencesUniversity of IdahoMoscowUSA
  2. 2.Department of Geological SciencesUniversity of IdahoMoscowUSA
  3. 3.Department of Environmental Science, I.E.N.S.Lancaster UniversityLancasterUK
  4. 4.Department of Biological and Agricultural EngineeringUniversity of IdahoMoscowUSA

Personalised recommendations