Evaluating the Fate and Transport of Emerging Contaminants 

Modeling PFAS Movement to Surface water and Groundwater

The twentieth century saw the development and application of new synthetic compounds across industrial and commercial sectors. These chemical varieties including per- and polyfluoroalkyl substances (PFAS) were favored for their chemical stability, water resistance, and surfactant qualities. While use of these and other synthetic compounds has declined, they are now ubiquitous and the scientific understanding of how they move through the environment is still emerging.

Stone’s Environmental Systems Modeling team applies quantitative, physically-based modeling techniques to estimate the fate and transport of PFAS in soil and water. One potential source of PFAS entering the environment is land-applied residuals. Biosolids derived from pulp and paper production and residuals from municipal wastewater facilities offer net environmental benefits, including soil health enhancement, nutrient recycling, carbon sequestration, and fertilizer and pesticide use reduction. However, these biosolids may contain PFAS, raising concerns about the safety of residual applications. In addition, since they do not readily degrade, PFAS have the potential to accumulate in soil and enter groundwater or surface water and may eventually contaminate drinking water sources.

We assist clients by applying the most appropriate and scientifically defensible modeling approaches to evaluate PFAS fate and transport in the environment. These include identifying models and parameters for setting screening-level criteria used in regulating permissible PFAS concentrations in soil and land-applied residuals. Screening-level modeling approaches may allow regulators and other stakeholders to efficiently evaluate PFAS groundwater contamination potential and determine whether a more comprehensive and rigorous modeling and/or field investigation is warranted. Our expertise in agrochemical fate and exposure modeling provides invaluable insights when identifying optimal management strategies to reduce surface water and groundwater contamination.

In addition to modeling, Stone’s Environmental Assessment and Remediation team designs comprehensive site evaluations of PFAS contaminants and determines optimal remediation strategies. Details on the capabilities of the Environmental Assessment and Remediation team can be found here.