Remediation Geology and Process-Based Conceptual Site Models to Optimize Groundwater Remediation

The Environmental Consulting Industry in the United States has historically prioritized engineering approaches over geologic science in addressing groundwater contamination. This engineering-centric bias has often resulted in oversimplified conceptual site models (CSMs) that fail to capture subsurface heterogeneity, limiting the effectiveness of groundwater remediation strategies. Recognizing the critical role of geology, the industry is increasingly adopting a Remediation Geology approach, which emphasizes the development of robust geologic models as the foundation for remediation programs. Geologic models optimize site lithologic data to define subsurface permeability architecture. The geologic model primarily serves as the structure to develop a Process-Based CSM, which is a holistic model that supports the entire remediation life cycle. A Process-Based CSM addresses the physical, chemical, and biological processes governing contaminant occurrence with the goal of modeling and predicting subsurface conditions for improved decision making with respect to monitoring programs and remediation design. Case studies highlight the transformative impact of Remediation Geology and Process-Based CSMs, demonstrating significant improvements in cleanup efficiency and resource optimization across diverse hydrogeologic settings. By addressing site complexities such as fine-grained units and fracture networks, Remediation Geology and Process-Based CSMs have proven effective for contaminants ranging from chlorinated solvents to per- and polyfluoroalkyl substances (PFASs) and radionuclides.