27-20 Quantifying the Influence of Geological Heterogeneity, Leakage Conditions, and Pumping Conditions on DNAPL Transport in a Pumped Industrial Aquifer

Session: Environmental Geochemistry and Health (Posters)

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Abstract:

Dense Non-Aqueous Phase Liquids (DNAPLs), such as trichloroethylene (TCE) and tetrachloroethylene (PCE), represent challenging contaminants due to their complex behaviors, high density, low solubility, and toxicity. Widely employed as degreasers in industrial activities, these chlorinated solvents persist as separate phases and migrate downward through groundwater when released into the subsurface. In industrial complexes, undocumented leakage incidents substantially increase the risks of groundwater and soil contamination. Furthermore, individual facilities frequently operate pumping wells for groundwater extraction, resulting in hydraulic disturbances that complicate DNAPL transport prediction.

This study quantitatively assesses the impacts of geological heterogeneity, leakage conditions, and pumping conditions on DNAPL transport through numerical simulations employing a full-physics modeling approach. Comprehensive geological and hydrogeological investigations were performed at an industrial site in South Korea, where a TCE-utilizing facility and a pumping well are located on the southern and northern sides, respectively. 3D distributions of geological media, porosity, and permeability were generated for the porous media zone from field data via Sequential Gaussian Simulation (SGS) employing various variogram models and parameters. Subsequently, a 2D numerical model, oriented north-south intersecting the pumping well, was extracted for full-physics simulations of DNAPL transport. Input parameters for leakage conditions (leakage number, average leakage location, distance between leakage locations, leakage rate, and leakage duration) and pumping conditions (pumping rate) were sampled using Latin Hypercube Sampling (LHS), generating multiple scenarios for numerical simulations. Relative importance of these input parameters was evaluated through Sobol global sensitivity analysis.

Preliminary results indicate that among the 50 realizations generated by SGS, the best-performing realization from the auto-fitted variogram yielded higher validation performance (R² = 0.72) compared to the best realization derived from the fixed variogram (R² = 0.66). However, the fixed variogram realizations exhibited superior average performance, whereas auto-fitted variogram realizations showed greater spatial heterogeneity. From ongoing 2D simulations, parameter influence is expected to vary depending on output parameters, simulation timescales, geological heterogeneity, and leakage conditions. Pumping and leakage rates are anticipated to significantly influence DNAPL distribution across scenarios. This research provides insights into key environmental and operational factors influencing DNAPL migration, thereby supporting effective contamination management and remediation strategies in industrial aquifers.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-9707

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