Investigation of PFASs in Water Supply Wells

M&A’s analytical and modeling work has been key to assessing the source areas and migration pathways for perfluoroalkyl substances (PFASs) in surface water and groundwater. The model will allow us to evaluate the future concentrations and distribution of this contaminant within the regional aquifer and our client’s wellfield.

Overview

PFASs — man-made chemicals that are widely used in manufacturing and firefighting — are highly persistent in the environment. Part of a larger group of perfluorinated chemicals (PFCs), PFASs comprise a chemical class that includes perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and other per- and polyfluoroalkyl substances. In 2016, the EPA established a lifetime health advisory of 70 parts per trillion for exposure to PFOA and PFOS, triggering new (nonenforceable) regulatory exceedances in groundwater supplies for many municipal and private water providers, including our client.

Services

M&A has been investigating the occurrence, distribution, and source areas of PFASs that have impacted our client’s primary wellfield. Services have included:

  • Analyzing available data to investigate hydrogeologic conditions, historic and current groundwater levels and gradients, surface water drainages, land uses, and potential PFAS source areas to identify possible routes to groundwater
  • Developing a conceptual model that integrates relevant factors (past and present) that may potentially affect PFAS distribution
  • Constructing a groundwater flow-and-transport model to simulate PFAS migration
  • Using the model to simulate various scenarios for PFAS source areas and transport, especially via surface water drainages, based on the present distribution of these compounds in our client’s wellfield