Tidal Influence on Remediation Sites: Understanding Predominant Gradients and Flow Inversion Effects on Mass Flux

Monday, December 4, 2017: 2:10 p.m.
Robert J. Stuetzle, P.Geo. , Environmental Remediation and Restoration, The Dow Chemical Company, La Porte, TX
James W. Schuetz, P.G. , Parsons, Buffalo, NY
Daniel Gomes , ERM, Denver, CO
Rick Wenzel, P.G. , Environmental Remediation and Restoration, The Dow Chemical Company, La Porte, TX

Many remediation sites across the globe are located in coastal settings or along the banks of tidally influenced rivers. Furthermore, the effects of tides on those nearby surface water bodies manifest themselves in the groundwater flow system. Understanding and quantitatively incorporating tidal influence into the conceptual site model (CSM) is key to predicting groundwater flow, contaminant transport, and mass flux at the site. Without correction for tidal effects, manually measured groundwater monitoring data can appear erratic, both spatially and from one event to the next. Mass discharge estimates can be challenging in these environments, due to daily groundwater flow inversions near the receiving surface water body, which tend to produce significant natural attenuation of plume fronts prior to discharge. Temporary deployment of transducers for continuous water level monitoring in a subset of existing monitoring wells and in the adjacent surface water body, has shown to provide the data necessary to develop correction factors for subsequent manual water level measurement events. Calculation of tidal efficiency and tidal time lag, once quantified, can normalize the hydraulic head data such that a true synoptic potentiometric surface can estimated. Beyond correcting for temporal variation to create snapshots of potentiometric surfaces in time, the continuous monitoring data can be used in conjunction with numerical modeling to understand the transient dynamic nature of tidally influenced systems, including flow inversions, net discharge flow, transient transport and mass flux. This combined approach provides a more comprehensive assessment of site risks and, ultimately, more realistic remediation goals. This presentation reviews site specific data where detailed head measurements and modeling techniques were used to obtain a comprehensive understanding of tidal influenced systems.
Robert J. Stuetzle, P.Geo., Environmental Remediation and Restoration, The Dow Chemical Company, La Porte, TX
Robert J. Stuetzle is a Hydrogeologist working as a Remediation Specialist for The Dow Chemical Company in La Porte, Texas. He earned his M.A.Sc in Water Resources Engineering supervised by Dr. Beth Parker and Dr. John Cherry, from the University of Guelph in 2014 and a B.Sc. in Science and Business: Hydrogeology Specialization from the University of Waterloo in 2010. He is also a registered Professional Geoscientist (P.Geo.) in Ontario, Canada.


James W. Schuetz, P.G., Parsons, Buffalo, NY
James (Jim) Schuetz is Licensed Professional Geologist with interdisciplinary experiences such as: field geology, hydrogeology, groundwater modeling, contaminant remediation, gold exploration, water resources, and regulatory negotiations. Jim has held positions at Parsons Corporation for 15 years, working on some of the country’s largest, most complicated remediation projects and currently serves as Subject Matter Director for Hydrogeology and Contaminant Transport. He holds Bachelor and Masters degrees from the University at Buffalo (Geological Sciences). He is currently the president of the Buffalo Association of Professional Geologists and supports various educational outreach programs.


Daniel Gomes, ERM, Denver, CO
Mr. Gomes is Technical Director at ERM, with over 30 years of experience in groundwater flow and solute transport assessment and modeling. He received his BSC. in Geology (1985) and M.Sc. in Hydrogeology (2004) from the University of São Paulo, supervised by Dr. Bob Cleary. Prior to this position Mr. Gomes worked for Waterloo Hydrogeologic, Schlumberger Water Services and served as a technical expert for several agencies of the United Nations system. He is currently the main instructor Of NGWA’s New Modflow Short Training Course.


Rick Wenzel, P.G., Environmental Remediation and Restoration, The Dow Chemical Company, La Porte, TX
Rick Wenzel is a Senior Remediation Leader at The Dow Chemical Company, covering the American Gulf Coast, Mexico and Colombia, with over 30 years of experience in soil and groundwater assessment and implementation of remedial measures. He earned a BS in Chemistry (1987) and a BS in Geology (1994) from the University of Houston and is a registered Professional Geologist in LA, MS and TX. He previously served as Remediation Manager for the North American Gulf Coast, Asia Pacific and Latin America Regions for Rohm and Haas Chemicals Co.


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