Detection of Dump Carbide Using the Resistivity Image Profiling Method: Case Study

Abstract

In pace with a growing focus on environmental protection, geophysical techniques to characterize abandoned hazardous sites contribute necessary information for remediation. Study of physical property distribution in the subsurface allows insight relevant to the successful investigation of such sites. Resistivity image profiling (RIP) is one of the most effective and stable geophysical techniques for contaminated land investigations where it is generally desirable to minimize ground disturbance. A former gas factory and carbide waste disposal site in Hsin-Hua County of southern Taiwan was being investigated. The site is located next to a low-density residential community and was previously considered unattractive. It is now being developed for domestic infrastructure and has to be cleaned. Records of dumping activities are poor. In order to estimate the budget of future remediation, RIP works were used to determine buried carbide geometry such as the thickness of fill and the spread of waste carbide. In addition, assessment of groundwater contamination associated with this landfill is also a main concern of this study. The thickness of waste carbide computed from RIP data was confirmed by post borings. The final carbide layer sections obtained from the RIP survey provide the base data to calculate the amount of carbide. Mapping of relative changes of resistivities with depth indicates that free water flows across the site in approximately a southwesterly direction. The presence of clayey soil may prevent a downward migration of leachate plume emanating from the carbide. Two-dimensional RIP resistivity surveying did very efficiently in waste carbide disposal explorations and provides relevant information on this area.