15 Oct 2020


Evaluation, Treatment and Source Protection – Lessons from the Epicenter of PFAS in Southeastern PA


Mr. Toby Kessler, P.G., Gilmore & Associates


The hydrogeologic evaluation and actions taken to address per- and polyfluorinated alkyl substances (PFAS) by a municipal public water supply in Southeastern PA provide valuable methods and insight for addressing PFAS throughout the Commonwealth. While PFAS are considered unregulated, the public water supplier is required to meet Safe Drinking Water requirements where sources contain levels greater than the EPA Health Advisory of 70 ppt for PFOS and/or PFOA, which include public notification and adding treatment to affected sources. The hydrogeologic evaluation of a specific water supply in Southeastern PA has included sampling of environmental media and wastes; borehole reconnaissance; evaluation of conceptual models for migration of PFAS; and including PFAS as part of the water supplier’s source water protection program. The hydrogeologic evaluation has informed the design, permitting, and construction of eight GAC treatment systems to remove PFAS in the drinking water supplies. Ion exchange resin have also been pilot-tested in a temporary treatment system, with ongoing efforts to permit ion exchange resin for use in permanent PFAS removal systems.