HR: 1340h
AN: H23A-1407    [Abstracts]
TI: Characterization of a Gas Station Site Contaminated with Fuel Hydrocarbons using Geophysical and Hydrogeological Investigations
AU: Kim, C
EM: ryol1102@kigam.re.kr
AF: Korea Institute of Geoscience and Mineral Resources, 30 Gajeongdong Yuseonggu, Daejeon, 305-350 Korea, Republic of
AU: * Ko, K
EM: kyungsok@kigam.re.kr
AF: Korea Institute of Geoscience and Mineral Resources, 30 Gajeongdong Yuseonggu, Daejeon, 305-350 Korea, Republic of
AU: Kim, J
EM: jungho@kigam.re.kr
AF: Korea Institute of Geoscience and Mineral Resources, 30 Gajeongdong Yuseonggu, Daejeon, 305-350 Korea, Republic of
AU: Park, S
EM: samgyu@kigam.re.kr
AF: Korea Institute of Geoscience and Mineral Resources, 30 Gajeongdong Yuseonggu, Daejeon, 305-350 Korea, Republic of
AU: Son, J
EM: jsson@kigam.re.kr
AF: Korea Institute of Geoscience and Mineral Resources, 30 Gajeongdong Yuseonggu, Daejeon, 305-350 Korea, Republic of
AU: Jeong, J
EM: jsson@kigam.re.kr
AF: Korea Institute of Geoscience and Mineral Resources, 30 Gajeongdong Yuseonggu, Daejeon, 305-350 Korea, Republic of
AU: Cho, S
EM: mac@kigam.re.kr
AF: Korea Institute of Geoscience and Mineral Resources, 30 Gajeongdong Yuseonggu, Daejeon, 305-350 Korea, Republic of
AB: The geophysical and hydrogeological investigations were conducted to characterize a former gas station site contaminated with gasoline and diesel hydrocarbons. The free product of petroleum hydrocarbons, LNAPL, was identified in the downgradient monitoring wells at the site, and also found in the seepage adjacent to the small stream, located approximately 50 meters downstream of the gas station in the southwest direction. To locate buries USTs and fuel lines, GPR (Ground Penetrating Radar) survey was performed at the site. The results of GPR survey showed the presence of buried the seven USTs including one unknown UST and two fuel lines. The electrical resistivity and additional GPR surveys were also conducted to map water table and to characterize shallow geologic structures over the inclined area covered with grass and plants. The investigation results showed that the shallow geologic structure includes: (1) upper soil unit of high resistivity values, mostly rock fragments with sand, (2) lower soil unit of low resistivity values, residual soils weathered from the bedrock which play a role as major groundwater path, and (3) bedrock, granite, of high resistivty values. These geophysical results well matched the sediment core logging. The results also show that the water table elevation varies with topography from approximately 1.5 to 3 meters below the ground surface. It is, therefore, believed that the free product leaked from the USTs and/or fuel lines at the station has transported downgradient over the water table beneath the inclined area and encountered the small stream located southwest of the station, and that most of petroleum-impacted zone lies within the residual, weathered soil near the water table in the area. The study results also show that the geophysical methods can be a very useful tool for characterization of the contamination sites.
DE: 0910 Data processing
DE: 0925 Magnetic and electrical methods (5109)
DE: 1828 Groundwater hydraulics
DE: 1835 Hydrogeophysics
SC: Hydrology [H]
MN: Fall Meeting 2005