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Case Study 2: PFAS Fate and Transport Modeling, Air Dispersion

Comprehensive PFAS Fate and Transport Modeling, Air Dispersion, and Well Infrastructure Assessment at a Fluorochemical Manufacturing Facility

RoseyFields conducted a comprehensive environmental investigation and exposure pathway assessment surrounding a large-scale fluorochemical manufacturing facility. Our team evaluated the historical and ongoing environmental releases of per- and polyfluoroalkyl substances (PFAS), focusing specifically on legacy processing aids like perfluorooctanoic acid (PFOA) and emerging replacement ether chemistries. The primary objective of this project was to characterize the environmental footprint of the facility’s operations by investigating manufacturing processes, chemical usage, and the complex migration of these highly persistent chemicals through multiple environmental media to understand their ultimate impact on regional groundwater and drinking water well infrastructure.

To determine the full extent of the environmental contamination, our team performed rigorous fate and transport analyses evaluating multiple complex exposure pathways. We derived chemical-specific partitioning coefficients and calculated source terms to estimate the mass of contaminants released into the air and water over several decades of operation. Our experts utilized advanced air dispersion modeling to quantify uncaptured stack emissions, assigning appropriate dry deposition velocities and scavenging coefficients to map the subsequent atmospheric fallout of PFAS particulates over a vast regional footprint. In addition to analyzing aerial deposition, we conducted comprehensive groundwater evaluations and soil assessments to identify how leaking underground infrastructure and unlined wastewater sumps leached liquid contaminants into the earth, migrated through the vadose zone, and deeply infiltrated regional aquifers.

Based on the results of our dispersion modeling and hydrogeological evaluations, RoseyFields characterized the extent of the environmental impact by identifying the specific public water systems and private domestic wells vulnerable to the facility’s contamination. We evaluated local hydrogeology, well construction data, and public utility infrastructure to delineate the boundaries of the impacted groundwater supplies, specifically focusing on well networks located within the established atmospheric deposition and groundwater plume zones. By integrating our source term calculations with these environmental models, our team successfully defined the impacted water infrastructure and provided the critical scientific foundation needed to evaluate drinking water exposure pathways and determine the necessity of advanced water filtration mitigation measures.

This investigation was conducted under the direction of Dr. Paul Rosenfeld, an environmental scientist and environmental forensic expert with extensive experience in environmental exposure assessment, toxicology, air quality, environmental fate and transport, risk assessment, and environmental forensics. Through RoseyFields LLC, Dr. Rosenfeld provides scientific consulting, environmental forensic analysis, regulatory support, and expert witness services involving environmental contamination, human exposure, and public health. His technical oversight helped ensure that the methodologies, scientific interpretations, and conclusions presented in this case study are consistent with accepted scientific principles and current best practices.