Organic Contamination Distribution Constrained with Induced Polarization at a Waste Disposal Site

Waste disposal sites are a serious concern due to their potential contamination threat. Site characterizations are the basis for contamination remediation, among which borehole-based methods are time-consuming. This study aims to utilize time-domain induced polarization (TDIP) to constrain groundwater and soil organic contamination. Fourteen TDIP profiles were arranged using three acquisition methods at a disposal site contaminated with benzene. A data quality analysis was first conducted to overcome poor signals in high-salinity groundwater conditions. The TDIP results show that solid waste can be classified into two distinct types based on chargeability. The results of induced polarization measurements and X-ray fluorescence analysis proved the presence of metal substances causing high chargeability. The waste with metals was the benzene contamination source. Finally, we propose a procedure for the integration of geophysical and geochemical methods to delineate contaminated areas. A new roll-along survey protocol was developed to meet the needs of long-profile surveys of contaminated shallow groundwater and soil sites.