Experience
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PFAS Fingerprinting – Appeal and Caveats
This video is meant for educational purposes; it presents simple PFAS fingerprinting scenarios; One involves two rivers and a fire training facility as a potential PFAS source. The goal is to identify the origin of PFAS detected in downstream surface water samples. A second scenario shows groundwater concentrations in monitoring wells, initially suggesting multiple sources. […]
Conceptual Understanding of PFAS Fractionation in Groundwater
This video explains why PFAS “chemical signatures” measured in groundwater can differ from place to place even when there is only a single contaminant source. The concept of PFAS fractionation (also referred to as PFAS enrichment) is a fundamental fate-and-transport process driven by differential sorption to organic carbon in aquifer materials. This microscale and macroscale […]
Review of Remediation Costs at RCRA Megasite
Independent forensic hydrogeology review of a large-scale groundwater remediation cost estimate prepared for a former industrial site. Why This Engagement Mattered Cleanup cost estimate exceeded $1.7 billion Cost driven primarily by assumed contaminant mass rather than measured conditions Required technical scrutiny beyond routine environmental review Scope of Review Examined conceptual site […]
Class Action Analysis: PFAS Impacts from Metal Plating Facility
Independent forensic hydrogeologic review of soil and groundwater data to evaluate PFAS source attribution and class certification implications. Why This Engagement Mattered PFAS detections in private wells formed the technical basis for a proposed class action. Class certification depended on whether observed PFAS conditions could be attributed to a single facility-related source or reflected […]
Hydrogeologic Exploration to Benefit Farmers in Morocco
Hydrogeologic reconnaissance was performed at 4 sites in the High Atlas Mountains and Middle Atlas Mountains in Morocco with the purpose of identifying locations for accessing groundwater for irrigation. The work was performed in collaboration with the High Atlas Foundation. This January 31, 2024, webinar presents the methodologies and findings of hydrogeologic reconnaissance […]
Estimated Allocation Share for Contaminated Sediment
Why This Engagement Mattered Determination of allocation share for contaminated river sediment required assessment of whether a former manufacturing facility contributed contaminants of concern at levels relevant to financial responsibility. The technical dispute focused on estimation of contaminant mass flux associated with permitted sewer discharges and the accuracy of calculations used within the allocation framework. […]