Monitoring of a Controlled LNAPL Spill Using Ground‐Penetrating Radar

Campbell, David L.; Lucius, Jeffrey E.; Ellefsen, Karl J.; Deszcz‐Pan;, Maryla

doi:10.4133/1.2922312

Cited by 26 publications

(25 citation statements)

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“…The replacement of pore water and air in the contaminated zone by LNAPL components will result in changes in the dc or static conductivity and relative permittivity. This would explain why early investigations of LNAPL contamination clearly show decreased electrical conductivity (Mazác et al 1990;DeRyck et al 1993;Lien and Enfield 1998) and enhanced GPR reflections (e.g., Daniels et al 1995;Campbell et al 1996;Lopes de Castro and Branco 2003) based on the insulating properties of LNAPL. Figure 3 shows the classic resistive response of fresh LNAPL spillage in a study conducted by DeRyck et al (1993).…”

Section: Short-term Geophysical Properties Of Sites Contaminated By Lmentioning

confidence: 93%

“…4). Campbell et al (1996) reported enhanced (brighter), higher amplitude GPR reflections in the region underneath a spill (Fig. 4 at 20-25 ns) during a controlled gasoline spill experiment at a test facility at the Oregon Graduate Institute.…”

Section: Short-term Geophysical Properties Of Sites Contaminated By Lmentioning

confidence: 95%

“…4a). Campbell et al (1996) suggest that the replacement of water with a relatively high dielectric permittivity of *80 by gasoline with a relatively low dielectric permittivity of *2 resulted in a high velocity GPR Campbell et al 1996) Surv Geophys (2010 layer concomitant with the bright spots. Incidentally, DeRyck et al (1993) also reported similar GPR reflection characteristics in their kerosene injection experiment.…”

Section: Short-term Geophysical Properties Of Sites Contaminated By Lmentioning

confidence: 95%

“…Experiments conducted by Campbell et al (1996) demonstrate the GPR response of early time spills (Fig. 4).…”

Section: Short-term Geophysical Properties Of Sites Contaminated By Lmentioning

confidence: 97%

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

Atekwana

2009

Surv Geophys

138

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Microorganisms participate in a variety of geologic processes that alter the chemical and physical properties of their environment. Understanding the geophysical signatures of microbial activity in the environment has resulted in the development of a new sub-discipline in geophysics called ''biogeophysics''. This review focuses primarily on literature pertaining to biogeophysical signatures of sites contaminated by light non-aqueous phase liquids (LNAPL), as these sites provide ideal laboratories for investigating microbialgeophysical relationships. We discuss the spatial distribution and partitioning of LNAPL into different phases because the physical, chemical, and biological alteration of LNAPL and the subsequent impact to the contaminated environment is in large part due to its distribution. We examine the geophysical responses at contaminated sites over short time frames of weeks to several years when the alteration of the LNAPL by microbial activity has not occurred to a significant extent, and over the long-term of several years to decades, when significant microbial degradation of the LNAPL has occurred. A review of the literature suggests that microbial processes profoundly alter the contaminated environment causing marked changes in the petrophysical properties, mineralogy, solute concentration of pore fluids, and temperature. A variety of geophysical techniques such as electrical resistivity, induced polarization, electromagnetic induction, ground penetrating radar, and self potential are capable of defining the contaminated zones because of the new physical properties imparted by microbial processes. The changes in the physical properties of the contaminated environment vary spatially because microbial processes are controlled by the spatial distribution of the contaminant. Geophysical studies must consider the spatial variations in the physical properties during survey design, data analysis, and interpretation. Geophysical data interpretation from surveys conducted at LNAPL-contaminated sites without a microbial and geochemical context may lead to ambiguous conclusions.

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Section: Short-term Geophysical Properties Of Sites Contaminated By Lmentioning

confidence: 93%

Section: Short-term Geophysical Properties Of Sites Contaminated By Lmentioning

confidence: 95%

Section: Short-term Geophysical Properties Of Sites Contaminated By Lmentioning

confidence: 95%

“…Experiments conducted by Campbell et al (1996) demonstrate the GPR response of early time spills (Fig. 4).…”

Section: Short-term Geophysical Properties Of Sites Contaminated By Lmentioning

confidence: 97%

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

Atekwana

2009

Surv Geophys

138

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“…Daniels et al (1995) attributed to the vapor phase of the gasoline displacing water a zone of diminished reflections from sedimentary features above the hydrocarbon floating in the vadose zone. On the other hand, Campbell et al (1996) report an enhanced, higher amplitude saturated zone reflection under the spill, in controlled spill experiments. Probably, the LNAPL displaces the water from the transition zone above the capillary fringe, thus making a sharp interface at the water table.…”

Section: Introductionmentioning

confidence: 88%