Evaluation of the impact of transition from porous to fractured rock media on 3D field-scale DNAPLs contamination

Taehoon Kim; Weon Shik Han; Seonkyoo Yoon; Peter K Kang; Jehyun Shin; Myung Jin Nam

doi:10.1016/j.jhazmat.2023.132711

Evaluation of the impact of transition from porous to fractured rock media on 3D field-scale DNAPLs contamination

J Hazard Mater. 2024 Jan 15:462:132711. doi: 10.1016/j.jhazmat.2023.132711. Epub 2023 Oct 5.

Authors

Taehoon Kim¹, Weon Shik Han², Seonkyoo Yoon³, Peter K Kang⁴, Jehyun Shin⁵, Myung Jin Nam⁶

Affiliations

¹ Department of Earth System Sciences, Yonsei University, Seoul, Republic of Korea.
² Department of Earth System Sciences, Yonsei University, Seoul, Republic of Korea. Electronic address: hanw@yonsei.ac.kr.
³ Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN, USA.
⁴ Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, MN, USA; Saint Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN, USA.
⁵ Groundwater Environment Research Center, Korea Institute of Geoscience and Mineral Resources, Daejeon, Republic of Korea.
⁶ Department of Energy Resources and Geosystems Engineering, Sejong University, Seoul, Republic of Korea; Department of Energy and Mineral Resources Engineering, Sejong University, Seoul, Republic of Korea.

PMID: 37827105
DOI: 10.1016/j.jhazmat.2023.132711

Abstract

A 3D high-resolution subsurface characteristic (HSC) numerical model to assess migration and distribution of subsurface DNAPLs was developed. Diverse field data, including lithologic, hydrogeologic, petrophysical, and fracture information from both in situ observations and laboratory experiments were utilized for realistic model representation. For the first time, the model integrates hydrogeologic characteristics of both porous (unconsolidated soil (US) and weathered rock (WR)) and fractured rock (FR) media distinctly affecting DNAPLs migration. This allowed for capturing DNAPLs behavior within US, WR, and FR as well as at the boundary between the media, simultaneously. In the 3D HSC model, hypothetical 100-year DNAPLs contamination was simulated, quantitatively analyzing its spatiotemporal distributions by momentum analyses. Twelve sensitivity scenarios examined the impact of WR and FR characteristics on DNAPLs migration, delineating significant roles of WR. DNAPLs primarily resided in WR due to low permeability and limited penetration into FR through sparse inlet fractures. The permeability anisotropy in WR was most influential to determine the DNAPLs fate, surpassing the impacts of FR characteristics, including rock matrix permeability, fracture aperture size, and fracture + rock mean porosity. This study first attempted to apply the field-data-based multiple geological media concept in the DNAPLs prediction model. Consequently, the field-scale effects of WR and media transitions, which have been often overlooked in evaluating DNAPLs contamination, were underscored.

Keywords: 3D Numerical Modeling; Field Scale DNAPLs Contamination; Fractured Rock; Site Characterization; Weathered Rock.