Geophysical techniques in the study of hydrocarbon-contaminated soil


Author : Umar Hamzah, Mohd Azmi Ismail & Abdul Rahim SamsudinPublication : Bulletin of the Geological Society of MalaysiaVolume : 54Page : 133-138Year : 2008


Description

Bulletin of the Geological Society of Malaysia, Volume 54, November 2008, pp. 133 - 138

 

Geophysical techniques in the study of hydrocarbon-contaminated soil

Umar Hamzah1, Mohd Azmi Ismail2 & Abdul Rahim Samsudin1

1Program Geologi, Pusat Pengajian Sains Sekitaran dan Sumber Alam, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia

2Agensi Nuklear Malaysia, MOSTI, Bangi, 43000 Kajang, Selangor, Malaysia

 

Abstract— Geophysical surveys in particular ground penetrating radar (GPR), electrical resistivity tomography (ERT) and vertical resistivity probe (VRP) were used in mapping subsurface geological structures and groundwater contaminants at Sungai Kandis, Klang to identify the approximate boundaries of contaminant plumes and to provide stratigraphic information at this site. The study area was formerly an illegal dumping site of hydrocarbon and toxic waste. A good correlation exists between GPR signatures, ERT layers, vertical resistivity probe and the contaminated soil. The presence of contaminant plumes as well as the water table are also observed in the GPR and ERT sections at depths approximately of 0.5 to 1 m. In this study, a total of 16 GPR traverses and 10 ERT lines with lengths from 30 to 100 m were established. VRP measurements were conducted in 14 shallow boreholes with a maximum depth of about 1m. The VRP results show high apparent resistivity values ranging from 200 to 10000 Ωm associated with oil contaminated layer. The presence of this layer was also detected in the 2D resistivity sections as a thin band of high resistivity values ranging from 60 to 200 Ωm. In the GPR section, the oil contaminated layer exhibits discontinuous, subparallel and chaotic high amplitude reflection patterns.

Keywords: ground penetrating radar, electrical resistivity tomography, vertical resistivity probe, contaminated soil