Induced-polarization detection and mapping of contaminant plumes

Abstract

Several laboratory and scaled model investigations suggest that organic contaminants affect the surface electrical properties of exposed soils/rocks and therefore produce measurable induced polarization (IP) signatures. However, there is little field evidence of an IP methodology for contaminant mapping. A 2D time-domain IP method is developed for mapping the FS-12 contaminant plume at the Massachusetts Military Reservation (MMR) located in Cape Cod, Massachusetts. The FS-12 plume consists of approximately [Formula: see text] of fuel that erupted from a broken underground pipeline in the early 1970s. Benzene and ethylene dibromide (EDB) are the primary contaminants at FS-12, with concentrations exceeding the allowed maximum concentration levels (MCL), while other constituents of the plume did not exceed their MCL. Therefore, the contaminants of interest are benzene and EDB, partly because of their health risk and partly because they present the highest concentrations (2400 and [Formula: see text], respectively) among the plume constituents and are therefore more likely to be related to the polarization source. IP data were acquired along a survey line that partially transects the plume extending over contaminated and uncontaminated zones and were inverted to give 2D resistivity and chargeability plots to [Formula: see text] depth and a horizontal extent of [Formula: see text]. By separately inverting IP data derived from time windows located at short and long decay times, a time-domain gross (spectral) chargeability difference is produced. Both the chargeability and gross spectral chargeability difference show good agreement with the known location of the plume from monitoring wells, with the IP chargeability section suggesting contaminant distribution detail that cannot otherwise be inferred from the sparse borehole distribution.

Geophysical Signatures of Microbial Activity at Hydrocarbon Contaminated Sites: A Review

“…Traditionally, the IP method has been predominantly used to investigate disseminated sulfide ores and to a lesser extent in groundwater exploration. However, in the last decade, IP techniques have increasingly been used in environmental applications to map contaminant plumes and for salt water intrusion studies (e.g., Slater and Lesmes 2002;Sogade et al 2006). IP measurements are sensitive to the low-frequency capacitative properties of rocks and sediments that result from diffusion controlled polarization processes at the interface between mineral grains and the pore fluid.…”

“…Over the past two decades, geophysical techniques have been employed at several LNAPL contaminated sites to characterize both the spatial (e.g., Benson and Stubben 1995;Bermejo et al 1997;Sauck et al 1998;Atekwana et al 2000;2004a;Osella et al 2002;Werkema et al 2003;Tezkan et al 2005;Abdel Aal et al 2006;Sogade et al 2006;Bradford 2007;Cassidy 2007) and temporal (e.g., Lopes de Castro and Branco 2003;Che-Alota et al 2009) extent to understand the evolution of the contamination in the subsurface. Many of these geophysical studies have provided valuable insights into the behavior of LNAPL contamination; however, the results remain mixed.…”

Induced polarization signatures of cations exhibiting differential sorption behaviors in saturated sands

“…At higher frequencies, the response of the rock is dominated by electromagnetic coupling and the Maxwell-Wagner polarization [Olhoeft, 1985[Olhoeft, , 1986. Because spectral induced polarization can be connected to the electrochemistry of the pore water -mineral interface [Olhoeft, 1985], this method has been proposed to detect and image contaminant plumes such as oil spills [Olhoeft, 1986;Vanhala, 1997;Morgan et al, 1999], benzene and ethylene dibromide plumes [Sogade et al, 2006], and organic-matter-rich contaminant plumes associated with leakages from landfills [Aristodemou and Thomas-Betts, 2000]. However, the work performed to date in geophysical applications has been rather qualitative.…”

Complex conductivity of soils

“…Induced polarization has many applications in hydrogeophysics including inference of hydraulic properties (Binley et al [2005]; Weller et al [2010], Joseph et al [2015]; Nordsiek et al [2015]), facies discrimination , the detection of contaminants in soils (e.g., Sogade et al [2006], Flores Orozco et al [2012], Schwartz and Furman [2012], Schmutz et al [2012], Chen et al [2013]), and the detection of cracks (e.g., Okay et al [2013]). Induced polarization has shown also a unique capability to monitor non-intrusively sorption processes in the electrical double layer (Vaudelet et al [2011a, b], Hao et al [2016]) and precipitation of metallic particles during redox-controlled reactions (e.g., Mewafy et al 4 [2013], Abdulsamad [2017]).…”