Time domain induced polarization data acquisition at contaminated sites

Abstract Time domain induced polarization (TDIP) has emerged as a highly effective tool for delineating contaminated sites. While numerous studies have focused on conceptual and mechanistic modelling, inversion methods, and coupled simulations to enhance accuracy, the acquisition of high-quality TDIP data has received insufficient attention. This research analyses the limitations of TDIP data quality in contaminated site surveys. Data acquisition layouts were evaluated from seven distinct sites, with a particular focus on the controlling factors that influence data quality. This study addresses the selection of reliable TDIP acquisition layouts and the assessment of information content regarding data quality. The results demonstrate significant differences in the raw data obtained through different acquisition layouts, with the inversion results derived from these datasets exhibiting varying degrees of discrepancy. The data quality associated with dual cables utilizing non-polarizable electrodes layout (Dual-CL-NP) is markedly superior, thereby ensuring the reliability of the results. Furthermore, apparent resistivity and measured voltage are identified as key factors controlling data quality. Finally, preliminary threshold values for selecting the acquisition layouts are established. Specifically, the Dual-CL-NP should be utilized when the average apparent resistivity of the TDIP profile is less than 7.9 Ωm. This threshold will be refined by adding more suitable field examples. Consequently, a preliminary guideline for TDIP data acquisition is proposed to address limitations associated with TDIP data quality and facilitates its advancement.