2013 NGWA Summit — The National and International Conference on Groundwater

Flow First, Sediment Second: Controlling the Flow of Contaminated Groundwater to Facilitate In-Stream Sediment Remediation

Tuesday, April 30, 2013: 8:00 a.m.
Regency West 6 (Hyatt Regency San Antonio)
Benjamin S. Johnson, Anchor QEA, LLC
John Edwards, RG, CEG, Anchor QEA, LLC
John J. Renda, RG, Anchor QEA, LLC
Michael Riley, PhD, Anchor QEA, LLC
Timothy Stone, Anchor QEA, LLC
Matt Wilson, Anchor QEA, LLC

At many sites, groundwater is a significant pathway for the contamination of stream bed sediments and surface waters by petroleum hydrocarbons and other organic chemicals. Here we detail the reasoning, design, implementation, and validation for an upland groundwater source control hydraulic containment system at a manufactured gas plant located along a tidally influenced river. Both upland groundwater remediation and river sediment cleanup actions are being designed and conducted at the site. Upland subsurface contamination associated with this site includes petroleum hydrocarbons, chlorinated solvents, and cyanide. To prevent recontamination of the river sediment, source control of the upland groundwater discharge must be implemented prior to the sediment remedy. The alluvial aquifer is more than 200 feet deep at this site, making hydraulic containment using extraction wells necessary. Step-­tests at upland pilot extraction wells have shown the extraction system will control groundwater seepage to the river. A network of 21 extraction wells will be used to maintain reversal of hydraulic gradients on 0.45 mile of shoreline along the site. Using field pump test data, the site MODFLOW models have shown that hydraulic containment is achievable across the full spectrum of environmental conditions, including low water events due to tidal and river discharge fluctuations. Water level measurements obtained from piezometers screened in the river sediment have shown that the upland extraction wells will effectively control seepage up to 500 feet from the river shoreline. By mid-2013, the extraction system will be completed, and the system mechanics will be validated. Validation of hydraulic containment will be done through the assessment of field parameters in transition zone piezometers, seepage rate measurements, temperature profiling, and water level gauging. Once upland source control of groundwater has been achieved, the in-stream sediment and upland groundwater remedies can be implemented.

Benjamin S. Johnson , Anchor QEA, LLC
Benjamin S. Johnson is a water quality professional with seven years of experience. He has worked extensively in groundwater, stream, and lake systems, performing environmental assessments and remediation projects. He holds a B.S. in Physical Geography and a minor in Geology from the University of Oregon and an M.S. in Environmental Science from Portland State University. Johnson is currently working as a Staff Geoscientist at Anchor QEA, where he assists with the design and implementation of groundwater projects, and is pursuing his credentials as a Professional Geologist.

John Edwards, RG, CEG , Anchor QEA, LLC
John Edwards, RG, CEG, is a contaminant hydrogeologist with 38 years of consulting experience. Most of his work has dealt with the investigation, cleanup, and redevelopment of contaminated industrial waterfront sites. The industrial sites have included lumber mills, pulp and paper, chemical manufacturing, wood treating, aluminum reduction, petroleum refineries, petroleum bulk terminals, asphalt plants, solvent recyclers, machine shops, and others. Edwards current work is primarily focused on the design and implementation of groundwater source control measures at the Portland Harbor CERCLA site in Portland, Oregon. Edwards is a partner at Anchor QEA, LLC and leads Anchor QEA's Geosciences Discipline.

John J. Renda, RG , Anchor QEA, LLC
Mr. Renda has nineteen years of experience working on environmental projects. His primary responsibilities include conducting remedial investigations, installing wells and advancing soil borings, aquifer testing at landfills, public utility plants, petroleum service stations, and manufacturing facilities, and managing groundwater monitoring projects. He has performed phase I and II environmental site assessments, remedial investigations, underground storage tank removals, and groundwater remediation projects. At Anchor QEA Mr. Renda serves as project manager for several projects at commercial and industrial facilities and prepares work plans for remedial investigations, voluntary cleanup programs, and expanded preliminary assessments.

Michael Riley, PhD , Anchor QEA, LLC
Dr. Riley has over 30 years of experience in investigating contaminant transport in groundwater, surface water, and sediments. He has applied numerical models related to groundwater hydrology, surface-water hydrology, sediment transport, and contaminant transport in groundwater and surface water to numerous site investigations located throughout the United States.

Timothy Stone , Anchor QEA, LLC
Mr. Stone began his career while studying environmental science, chemistry, and economics at the University of Iowa. From 1990 through 1996, Mr. Stone managed phyto-remediation research facilities and projects. During this period he was employed by Ecolotree, Inc. which utilized phyto-technologies to remediate contaminants in soil, groundwater, and surface water. Since 1997, Mr. Stone has served as a professional scientist based in Portland, OR and has designed, managed, and implemented groundwater monitoring and extraction well networks, and automated groundwater control systems. He currently serves as a Senior Geoscientist at Anchor QEA, LLC in Portland, Oregon.

Matt Wilson , Anchor QEA, LLC
Mr. Wilson is a geologist with 11 years’ experience. After graduating from the University of Texas in 1991 Mr. Wilson went on to work for International Technology Corporation (IT) in Austin, Texas. For the next six years Mr. Wilson installed monitoring well networks, performed site investigations, and conducted hydrogeological analyses. Since working at IT Mr. Wilson has continued his work as a geologist at Anchor QEA. At Anchor QEA Mr. Wilson has worked on the design and construction of a hydraulic capture and control system and performs a groundwater and sediment investigations.