"Direct Push Optical Screening Tool for High-Resolution, Real-Time Mapping of Chlorinated Solvent DNAPL Architecture" by Mr. Murray Einarson

Cleanup of sites with residual chlorinated solvent dense non-aqueous phase liquid (DNAPL) has been hampered by the significant challenge of locating the DNAPL in the subsurface. Solvent DNAPL is often colorless and is distributed in complex pools, veils, and ganglia in the subsurface that are difficult to identify and delineate using conventional soil and groundwater sampling tools and sensors (e.g., Membrane Interface Probe [MIP]). Colorimetric dyes such as Sudan 4 and Oil-Red-O can be used to test soil samples for the presence of chlorinated solvent DNAPL but those tests are expensive, time-consuming, and biased by the soil sample collection method. Laser-Induced Fluorescence (LIF) technologies advanced on direct push platforms are extremely effective in quickly delineating the distribution of NAPL in the subsurface. Unfortunately, LIF technologies target polynuclear aromatic hydrocarbons (PAHs) in DNAPL. Chlorinated solvent DNAPL are invisible to LIF technologies. LIF was modified to detect chlorinated solvent DNAPL under ESTCP Project ER-201121. By injecting a small stream of a hydrophobic fluorescent dye ahead of the LIF detector, residual chlorinated solvent DNAPL can now be quickly delineated in three dimensions using a new version of LIF called “DYE-LIF™.” This presentation will describe work to validate the technology performance at a site with residual chlorinated solvent DNAPL.

“High-Resolution Delineation of Chlorinated Solvent Concentrations, Biogeochemical Processes, and Microbial Communities in Saturated Subsurface Environments” by Dr. Andrew Jackson

The prediction of chlorinated solvent fate and transport in aquifers is often limited by heterogeneity associated with groundwater flow, contaminant distribution, and relevant biotic and abiotic reactions. Processes occurring in low permeability zones are particularly important because contaminants residing in such materials can sustain groundwater plumes and impede overall contaminant attenuation. This presentation will describe an ESTCP project to develop a direct push high-resolution passive profiler (HRPP) to quantify and delineate the distribution of chlorinated solvents, groundwater velocity, geochemistry, and microbial community activity within complex layered aquifers. The project successfully demonstrated these capabilities during two field deployments. Data produced from the HRPP was compared to a variety of traditional site assessment tools including sediment extractions from cores, a membrane interface probe (MIP), a hydraulic profiling tool (HPT), multi-level wells, and passive flux meters. Results show that HRPP produces comparable data to these other monitoring tools with the advantage of direct push, high-resolution integrated data sets and independence from permeability of the formation. The HRPP offers a comparatively low cost technology to enable better site modeling, remediation design, and monitoring of remedial activities, resulting in an overall cost reduction for site management.

 Mr. Murray Einarson is a principal hydrogeologist working with Haley & Aldrich, Inc. in Oakland, California. He has over 30 years of experience as an environmental consultant and groundwater researcher, and is a certified hydrogeologist in California. He has focused his career on developing and promoting new methods and technologies that improve environmental site characterization and in situ remediation. He has coauthored industry and regulatory guidance documents on high-resolution site characterization. For these efforts, he received the National Ground Water Association (NGWA) Technology Award in 2009. He has a Bachelor of Arts degree in geology from the University of California, Santa Barbara, and a Master of Science degree in hydrogeology from the University of Waterloo.
 

Dr. Andrew Jackson is a Professor of Civil and Environmental Engineering at Texas Tech University in Lubbock, Texas. His research interests include evaluating the fate (e.g., transformation, sorption, plant uptake) of a variety of military contaminants including perchlorate, RDX, and chlorinated solvents. He also develops methods to study these processes in the natural environment at appropriate scales. He has published over 90 journal publications and book chapters. Dr. Jackson has served as a principal investigator on grants sponsored by a variety of agencies including Environmental Protection Agency, Department of Energy, SERDP, National Aeronautics and Space Administration, and the United States Department of Agriculture. His work has recently focused on applying and expanding passive sampling technologies to support site management. He received his B.S. degree in Biology from Rhodes College and M.S. and Ph.D. degrees from Louisiana State University in Engineering Science with an emphasis in Environmental Engineering. He is a registered professional engineer in the State of Louisiana.