Direct Mass Flux Measurements for 1,4-Dioxane From an Industrial Site in a Karst Aquifer

Tuesday, September 24, 2019: 10:50 a.m.
Samuel Jacobson, BSc , G360 Institute for Groundwater Research, University of Guelph
Beth L. Parker, Ph.D., LEL , G360 Institute for Groundwater Research, University of Guelph, Guelph, ON, Canada
Emmanuelle Arnaud, Ph.D , School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
John A. Cherry, Ph.D. , G360 Institute for Groundwater Research, University of Guelph, Guelph, ON, Canada
Carlos Henrique Maldaner, Ph.D. , G360 Institute for Groundwater Research, University of Guelph, Guelph, ON, Canada
Steven Chapman, M.Sc., P.Eng. , G360 Institute for Groundwater Research, University of Guelph, Guelph, ON, Canada
Michael D. Annable , University of Florida, Gainesville, FL
Kirk Hatfield, Ph.D. , University of Florida, Gainesville, FL
Robert E. Bretnall, P.G. , HSW Engineering, Gainesville, FL

Several sites are possible contributors to trace 1,4-dioxane detections in a municipal supply well in the karstic Upper Floridan aquifer. Efforts are underway to assess potential contribution from one nearby industrial site; however, high aquifer transmissivity and site dimensions create uncertainty in hydraulic gradients, thus stripping confidence from conventional Darcy’s law-based mass flux calculations. To avoid multiple measurement uncertainties, we advanced direct mass flux measurement techniques in two cored holes to characterize this site. Depth-discrete, high resolution rock core contaminant profiles were developed, and borehole geophysical and hydrophysical logs were collected. Physical caliper profiles captured the significant variability in borehole diameter, locating zones that could be sealed using FLUTe™ borehole liners. Hydraulically active features under natural hydraulic conditions were qualitatively identified using active distributed temperature sensing (A-DTS). These datasets informed placement of modified, fractured rock passive flux meters (PFM) in multiple, depth-discrete zones (1-2 m long), to quantify both water and contaminant flux. Vertical arrays of pressure and temperature sensors were co-deployed with the PFMs, external to the FLUTe™ liners, to capture transient hydraulic conditions. This presentation will discuss challenges and adjustments made for karstic boreholes as well as in-situ groundwater and contaminant flux distributions used to estimate mass discharge.
Samuel Jacobson, BSc, G360 Institute for Groundwater Research, University of Guelph
Graduated in 2017 with a bachelors of science in geology from Bucknell University. Undergraduate research focused on developing a novel tracer for use in NAPL contaminated karst systems. Current research topics include contaminant transport in karst and fractured bedrock systems.


Beth L. Parker, Ph.D., LEL, G360 Institute for Groundwater Research, University of Guelph, Guelph, ON, Canada
Beth L. Parker has her bachelors degree in environmental science and economics, Masters in environmental engineering and PhD in hydrogeology She is Professor in the School of Engineering and Director of G360 - The Centre for Applied Groundwater Research at the University of Guelph. She has more than 25 years of experience as a groundwater professional investigating subsurface contamination issues at industrial sites around the world. Her current research activities emphasize field and laboratory studies of DNAPLs in sedimentary rocks, clayey deposits, and heterogeneous sandy aquifers, and focus on the effects of diffusion into and out of low permeability zones and on DNAPL fate, plume attenuation, and controls on remediation. She is currently involved in research and technology demonstration projects at Superfund and RCRA facilities in the United States and similar sites in Canada, Europe and Brazil. In July 2007, she was awarded an NSERC Canada Industrial Research Chair in Fractured Rock Contaminant Hydrology. In December 2009, she received the John Hem Award from the Association of Groundwater Scientists and Engineers of the United States National Groundwater Association.


Emmanuelle Arnaud, Ph.D, School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
Dr. Arnaud holds a PhD in Geology (McMaster University). She joined the University of Guelph in 2002 and is currently an Associate Professor in the School of Environmental Sciences and an active member of the G360 Institute for Groundwater Research. She has expertise in the field-based analysis of sediments and sedimentary rocks. Her current research interests lie in better understanding the heterogeneity of subsurface glacial sediments and how it impacts groundwater recharge and contaminant transport; improving our ability to predict groundwater susceptibility in specific geologic settings, and better understanding the impact of glaciation on associated karstic and sedimentary bedrock aquifers.


John A. Cherry, Ph.D., G360 Institute for Groundwater Research, University of Guelph, Guelph, ON, Canada
John Cherry is the Director of the University Consortium for Field-Focused Groundwater Contamination Research, Associate Director of G360 Centre for Applied Groundwater G360–The Centre for Groundwater Research, and Adjunct Professor in the School of Engineering at the University of Guelph. He is a Distinguished Professor Emeritus at the University of Waterloo. Cherry co-authored the textbook Groundwater with R.A. Freeze (1979) and co-edited and co-authored several chapters in the book Dense Chlorinated Solvents and Other DNAPLs in Groundwater.


Carlos Henrique Maldaner, Ph.D., G360 Institute for Groundwater Research, University of Guelph, Guelph, ON, Canada
Postdoctoral researcher at the G360 Institute for Groundwater Research. Dr. Maldaner's research focuses on novel applications of thermal tracer techniques in fractured bedrock aquifers.


Steven Chapman, M.Sc., P.Eng., G360 Institute for Groundwater Research, University of Guelph, Guelph, ON, Canada
Steve is a Senior Research Engineer / Hydrogeologist in the G360 Institute for Groundwater Research at the University of Guelph. He is a Professional Engineer (Civil) with a M.Sc. from the University of Waterloo (Earth Sciences) and has more than 20 years of hydrogeologic experience. His research focuses on contaminant behavior in diverse geological environments including unconsolidated porous media and fractured bedrock involving high resolution site characterization at industrial and research sites. He is also a specialist applying advanced numerical models with a focus on the role of diffusion and other processes on plume behavior and impacts on remediation performance.


Michael D. Annable, University of Florida, Gainesville, FL
Michael Annable is a professor at the University of Florida with interests in groundwater remediation, tracer tests, environmental engineering, and hydrologic science.


Kirk Hatfield, Ph.D., University of Florida, Gainesville, FL
Kirk Hatfield received his BS and MS degrees from University of Iowa and his PhD degree from University of Massachusetts in Amherst. He joined the University of Florida, Department of Civil Engineering in 1987. He currently serves as the Director of the new Engineering School of Sustainable Infrastructure and Environment and Director of the Florida Water Resources Research Center and member of the Board of Directors of the National Institutes of Water Resources. Hatfield’s ongoing research activities are in the areas of aqueous environmental monitoring, contaminant fate and transport modeling in the subsurface, environmental remediation, and water resources systems analysis.


Robert E. Bretnall, P.G., HSW Engineering, Gainesville, FL
Bob Bretnall is a hydrogeologist with over 32 years of direct experience in planning and managing complex environmental projects and investigations. Mr. Bretnall has demonstrated expertise in groundwater remediation systems monitoring, operations, and maintenance, contract management, organizing and tracking multiple projects, budgeting, quality control, technical report preparation, compliance with state and federal regulations, and staff training and supervision.