A conceptual site model (CSM) explains and quantifies the subsurface migration of contamination. To illustrate the subsurface conditions that control the migration of contaminants, 3D modeling technology is regularly used to build understandable and useful CSMs. In the following presentations, three different types of environmental investigation data are utilized to develop CSMs:

CSM #1–Analytical Data: A 3D model was built using soil analytical data from seven different contaminants. Each contaminant was modeled individually to show the volume of soil above each contaminant’s remediation objective. The CSM accurately calculated the volume of impacted soil and ensured that the remedial exceedances were delineated.

CSM #2–Geologic and Groundwater Data: A 3D hydrogeologic model was built from boring logs and groundwater elevation data. The CSM explained how the interaction between the groundwater table and a clay unit in the subsurface created locations where free-phase LNAPL was being confined below the clay layer at some locations and collecting above it in others.

CSM #3–Laser-Induced Fluorescence and Cone Penetrometer Test Data: A high-resolution 3D model was built from over 30,000 data points. The CSM identified two different sources of petroleum contamination and showed how the geology effected the migration of contamination in the subsurface.

Primary Author / Conference Presenter:
Jim Depa
Sr. Project Manager
St. John-Mittelhauser & Associates, A Terracon Company
Downers Grove, Illinois, USA

Ron St. John, St. John-Mittelhauser & Associates, A Terracon Company, Downers Grove, IL