Occurrence and persistence of perfluorooctanesulfonate and other perfluorinated surfactants in groundwater at a fire-training area at Wurtsmith Air Force Base, Michigan, USAElectronic supplementary information (ESI) available: Map of location of Wurtsmith Air Force Base, Oscoda, MI and surrounding states. See http://www.rsc.org/suppdata/em/b2/b212497a/

TLDR

Fire‑training at Wurtsmith Air Force Base used aqueous film‑forming foams from the 1950s to 1993, and the resulting AFFF‑laden wastewater entered groundwater untreated, introducing perfluorinated surfactants into the aquifer. Groundwater samples were screened for perfluoroalkanesulfonates and perfluorocarboxylates, with sulfonates detected by negative‑ion electrospray ionization mass spectrometry and carboxylates identified after derivatization by electron‑impact gas chromatography‑mass spectrometry. Analysis of wells near the fire‑training area FTA‑02 revealed four perfluorinated surfactants—PFOS, PFHxS, PFOA, and PFHxA—at concentrations of 3 to 120 µg L⁻¹, confirming that PFOS remains detectable in groundwater more than five years after its last use.

Abstract

Various formulations of fire-extinguishing materials, including aqueous film-forming foams (AFFFs), were used as part of fire-training exercises conducted at Wurtsmith Air Force Base (WAFB) in northeastern Michigan from the 1950s until the base was decommissioned in 1993. As a result of past fire-training exercises, AFFF-laden wastewater containing fuels, solvents, and other materials directly entered groundwater without prior treatment. Perfluorinated surfactants are key components in some AFFF formulations. In this study, groundwater was analyzed for perfluoroalkanesulfonates and perfluorocarboxylates. Perfluoroalkanesulfonates were directly detected using negative-ion electrospray ionization mass spectrometry. Derivatized perfluorocarboxylates were detected using electron impact gas chromatography-mass spectrometry. Groundwater from wells around fire-training area FTA-02 at WAFB contained four perfluorinated surfactants ranging in concentration from 3 to 120 microg L(-1): perfluorooctanesulfonate (PFOS); perfluorohexanesulfonate; perfluorooctanoate; and perfluorohexanoate. This is the first report demonstrating that PFOS, recently shown to be toxic to organisms ranging from zooplankton to primates, is still present in groundwater in measurable quantities five or more years after its last known use.