Employing Multiple Lines Of Evidence As A Remediation Decision-Making Tool At A Fractured Rock Site

Monday, September 23, 2019: 11:20 a.m.
Brent Aigler, P.G. , Geological Sciences, University of Colorado
Dan Bryant, Ph.D., P.G. , Woodard & Curran, East Windsor, NJ
Peter Nangeroni, P.E. , Woodard & Curran, Dedham, MA
Neven Kresic, Ph.D., P.G. , Woodard & Curran, East Windsor, NJ

Multiple lines of evidence demonstrate that sustained elevated concentrations of dissolved volatile organic compounds (VOCs) and 1,4-dioxane in a fractured rock aquifer at a site in Rhode Island reflect stagnation of a detached plume rather than a separate nearby release that, if present, may warrant active remediation. Being able to substantiate a conceptual site model (CSM) of a detached groundwater plume is of critical importance at this site because it avoids the unwarranted expenditure of energy and resources to remediate a source area that is not present. This work presents the various data-collection methods and hydrogeologic assessments that were implemented at the site to iteratively develop a lines-of-evidence approach in support of a robust CSM that forms the basis of an exit strategy at the site. Lines of evidence supporting the CSM of a detached plume include: the history of chemical impacts to the study area; hydraulic influence on the study area by source-area remedies and groundwater extraction; results of borehole geophysical and geological assessments; the distribution of recently obtained per- and polyfluoroalkyl substances (PFAS) data; and an analysis of VOC fingerprinting and chemical gradients of the study area and the remediated source area.

Brent Aigler, P.G., Geological Sciences, University of Colorado
Brent Aigler is a licensed Professional Geologist with Woodard & Curran, specializing in hydrogeologic modeling, geospatial analysis, data visualization, and site characterization. His responsibilities include planning and implementing field investigations programs at sites impacted by petroleum/LNAPL, VOCs, 1,4-Dioxane, and PFAS. He has served as the project geologist for groundwater modeling programs in New England and California and provides data analysis/data visualization support for state and federal remediation sites.


Dan Bryant, Ph.D., P.G., Woodard & Curran, East Windsor, NJ
Dan Bryant holds a bachelor’s and master’s degrees in geology from the University of Florida and a Ph.D. in geochemistry from Columbia University. He has over 20 years of experience in the field of in-situ chemical remediation, and three patents for in-situ bioremediation and chemical treatment of organic contaminants.


Peter Nangeroni, P.E., Woodard & Curran, Dedham, MA
Peter Nangeroni has over 30 years of due diligence, site investigation and remediation, redevelopment planning, environmental engineering, construction management, and solid and chemical waste management experience. He also has extensive experience in the evaluation of remedial alternatives and the management of diverse project teams in the conceptualization, design, permitting, construction, and operation of remedial programs, with an emphasis on PRP-led CERCLA sites.


Neven Kresic, Ph.D., P.G., Woodard & Curran, East Windsor, NJ
Dr. Neven Kresic has over three decades of groundwater and surface water-related consulting, research, and teaching experience, including major projects in the United States, Eastern Europe, Middle East, North Africa, and South America. He provides company-wide expertise and leads Groundwater Practice. Dr. Kresic has worked with U.S. and international clients, including federal, state, and local agencies; industries such as water, transportation, and power utilities; and oil, petrochemical, chemical, mining, and construction companies. His areas of expertise include groundwater engineering, development, and remediation; groundwater modeling; karst and fractured rock hydrogeology; water resources evaluation; and expert witness testimony.