Abstract

“Development of a Borehole Technology to Understand Dual-Domain Mass Transfer and Inform Contaminant Transport Models” by Dr. Ramona Iery (SERDP Project ER-201732)

Classical advective-dispersive transport cannot explain contaminant rebound after the cessation of pumping or the long-time horizons for cleanup observed at many sites undergoing groundwater remediation. Alternative models considering DDMT, also referred to as mobile/immobile exchange, are used to model the retention of contamination in low-permeability regions or in the rock matrix around fractures. In these models, contaminants move by advection through the mobile porosity and move in and out of immobile porosity by diffusion or slow advection. This presentation will review recent ESTCP-funded research to investigate and demonstrate geophysical approaches to quantitatively estimate the rate coefficient governing mobile/immobile exchange and the immobile porosity. These parameters are critically important in reliable and accurate model-based prediction and optimal design of remediation strategies. This presentation will also discuss the basis for monitoring DDMT using geoelectrical measurements, which are sensitive to both mobile and immobile porosity, in contrast to conventional sampling. A new borehole technology, MI-PET, and a simple curve-fitting approach for data analysis and parameter estimation will also be demonstrated. Lastly, the webinar will explain how nuclear magnetic resonance, spectral-induced polarization, and geophysical methods may help constrain estimation of parameters controlling DDMT.

Dr. Ramona Iery is an Environmental Engineer at the Naval Facilities Engineering and Expeditionary Warfare Center (NAVFAC EXWC) with 15 years of experience in the field of environmental remediation. Her areas of expertise include fate and transport, site characterization, long term monitoring and remediation of contaminants including chlorinated solvents, petroleum hydrocarbons and emerging contaminants such as 1,4-dioxane and per- and polyfluoroalkyl substances (PFAS). She has published some of the first articles showing abiotic monitored natural attenuation of chlorinated solvents and is a co-principal investigator on a SERDP project on abiotic transformation in low permeable zones (ER-2622). Dr. Iery authored the Navy’s Biogeochemical Transformation fact sheet and white paper. She has a master’s degree in civil and environmental engineering from Tennessee State University and a doctoral degree in environmental engineering and science from Clemson University.

Dr. Lee Slater is the Henry Rutgers Professor of Geophysics at Rutgers University in Newark, New Jersey. His current areas of research include the development of borehole-based geophysical technologies for improving understanding of how rock properties control flow and mass transport, as well as geophysical monitoring technologies to track amendment delivery and long-term biogeochemical alterations caused by contaminant degradation. Dr. Slater has served as the principal investigator on several research grants focused on the use of geophysical techniques, primarily electrical methods, for investigating flow and transport processes in numerous geological settings. He has published widely on the application of geophysics to site characterization and remediation monitoring. Dr. Slater earned a bachelor's degree in environmental science from the University of East Anglia in Norwich, England, a master's degree in marine geotechnics from the University College of North Wales, and a doctoral degree in environmental science from Lancaster University in Lancaster, United Kingdom.

Dr. Fred Day-Lewis is a chief geophysicist and laboratory fellow at Pacific Northwest National Laboratory. His current research focuses on geophysical monitoring and characterization in support of groundwater remediation, water supply, and water resiliency. Dr. Day-Lewis has led and contributed to applied research projects on high-resolution site characterization, fractured rock hydrology, performance monitoring, aquifer storage recovery, and groundwater/surface-water exchange. He has served as an associate editor for the journals Water Resources Research, Groundwater, Hydrogeology Journal, and Geosphere. He is a past president of the American Geophysical Union (AGU) near surface geophysics section. He was elected a fellow of the Geological Society of America in 2015 for seminal contributions to hydrogeophysics. Dr. Day-Lewis earned bachelor’s degrees in English and hydrology from the University of New Hampshire and a doctoral degree in hydrology from Stanford University.