Role of Geologic Faults on Contaminant Plume Morphology and Implications for Remediation

Monday, September 23, 2013: 3:25 p.m.
David S. Lipson, Ph.D., PG , ARCADIS U.S. Inc., Lakewood, CO
Tracy Deeds, PG , ARCADIS US Inc., Lakewood, CO
Erik Gaiser, PG , ARCADIS U.S., Inc., Los Angeles, CA

Groundwater remediation in fractured rock can be challenging, impracticable, or even impossible due to structural controls including faults, folds and joints. Such features complicate evaluation, selection, and implementation of effective remediation strategies. Failure to account for these controls can result in remedies that are ineffective and can exacerbate problems. We designed groundwater remediation programs at three contaminated sites where complex plume morphologies were controlled by geologic faults. The remediation programs took into account the structural geology present at these sites and are in various stages of implementation and monitoring.

To properly conceptualize the sites, we used groundwater modeling, bedrock coring, downhole televiewers, and high-resolution groundwater monitoring, as well as fracture analysis, hydraulic testing, geochemical evaluations, and analysis of rock samples. This information was used to conceptualize the sites, determine the dominant controls on complex plume morphology, evaluate failure modes, and design remedial programs.

Results showed that geologic faults can exert significant control on the fate, transport, and remediability of groundwater contaminants, and resulted in complex plume shapes and migration patterns that would not be predicted assuming homogeneous and isotropic conditions. Not considering geologic structures during site characterization, remedial design, and implementation would have resulted in the implementation of ineffective remedial strategies.

David S. Lipson, Ph.D., PG, ARCADIS U.S. Inc., Lakewood, CO
David Lipson has more than 22 years of experience as a contaminant hydrogeologist with particular emphasis on chemical transport, subsurface remediation, and fractured bedrock hydrogeology. He provides technical support on a wide range of groundwater contamination and remediation projects. Lipson is well-versed at using mathematical models, engineering controls, and risk-based corrective action approaches at sites regulated under CERCLA, RCRA, and state-led regulatory programs. He earned a doctorate degree in Geological Engineering at Colorado School of Mines, a master’s degree in Hydrogeology at Syracuse University, and a bachelor’s degree in Geology at the State University of New York.


Tracy Deeds, PG, ARCADIS US Inc., Lakewood, CO
Tracy Deeds has nine years of experience as a geologist working on environmental projects in a variety of complex hydrogeologic settings. Ms. Deeds’ experience has focused on supporting groundwater remediation efforts at contaminated properties and includes developing site conceptual models, designing site investigation programs, collecting and analyzing hydrogeologic data, and providing technical support during remediation design and implementation. Ms. Deeds has extensive experience characterizing the geology at contaminated sites in southern California.


Erik Gaiser, PG, ARCADIS U.S., Inc., Los Angeles, CA
Erik Gaiser has 15 years of experience as a hydrogeologist working in both the water resources and environmental fields. Mr. Gaiser has focused on facies interpretation, conceptual site model development, and fate and transport analyses. He has acted as a lead hydrogeologist and technical resource for many water resource projects and environmental investigation sites ranging from retail petroleum sites to RCRA facilities. Mr. Gaiser currently serves as ARCADIS’ west coast lead for the Triad Investigation practice which specializes in high-resolution, real-time, adaptive design investigations. Mr. Gaiser earned a Bachelor’s of Science Degree in Geology at California State University Fullerton.