Modeling PFAS Fate and Transport in Groundwater, with and Without Precursor Transformation.
Michael J Gefell1, Hai Huang2, Dan Opdyke3
1Anchor QEA, LLC, Lakewood, CO, 80228, USA.
Ground Water
|December 1, 2021
Summary
Per- and polyfluoroalkyl substances (PFAS) precursors can significantly impact groundwater contamination, extending perfluoroalkyl acid (PFAA) plume durations for decades. Understanding precursor behavior is crucial for accurate environmental modeling and remediation strategies.
Area of Science:
- Environmental Science
- Hydrogeology
- Environmental Chemistry
Background:
- Groundwater contamination by per- and polyfluoroalkyl substances (PFAS) is a growing concern.
- Evaluating the impact of PFAS precursors on perfluoroalkyl acid (PFAA) plumes is technically challenging.
- Existing models need enhancement to fully incorporate precursor dynamics.
Purpose of the Study:
- To assess the influence of PFAS precursors on the behavior and longevity of PFAA groundwater plumes.
- To determine how precursor presence affects PFAA plume concentrations and duration.
- To identify areas for future research to improve predictive modeling of PFAS contamination.
Main Methods:
- Numerical modeling was employed to simulate groundwater plumes.
- Model parameters, including mass loading rates and precursor presence, were adjusted.
- Simulations compared plume characteristics with and without PFAS precursors.
Main Results:
- Source zones with or without precursors can yield similar PFAA plumes when mass loading rates are adjusted.
- The presence of a precursor significantly impacts PFAA plume concentrations.
- Precursors can extend the duration of PFAA plumes by decades.
Conclusions:
- PFAS precursors play a critical role in the long-term behavior of PFAA groundwater plumes.
- Further research into in situ precursor transformation rates is essential.
- Improved source area characterization is needed to enhance the predictive accuracy of groundwater models for PFAS.
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