Groundwater Consulting Services for PFAS - Former Military Base, Northern Virginia

Challenge: Emery & Garrett Groundwater Investigations, a division of GZA (EGGI/GZA), has provided groundwater consulting services to a former military base for 15 years as part of the base’s redevelopment. The mixed-use development proposed for the site will be exclusively reliant upon groundwater resources to meet its current and anticipated potable water supply needs, utilizing a combination of existing wells that had served the military base and new production water supply wells that have been developed and permitted by EGGI/GZA over the past 10 years. Given the previous land use as a military base, EGGI/GZA recommended that the current owner/operator of the water system proactively test all existing and proposed production wells for per- and poly fluoroalkyl substances (PFAS) compounds; PFAS was detected in a proposed production well, not yet in service, above the combined PFOS/PFOA EPA Advisory Level. The utility looked to EGGI/GZA to determine the potential sources of PFAS contamination and to find a replacement water supply well and/or evaluate water treatment options.

Solution: EGGI/GZA and the water utility advised the U.S. Army of the presence of PFAS compounds found at the site; the Army has become actively engaged in a plan to address the contamination. EGGI/GZA is conducting a groundwater exploration program on a portion of the property, away from the suspected PFAS contaminated areas, in an attempt to develop replacement or supplemental water supply well(s). EGGI/GZA is also conducting an initial site investigation into the possible source of PFAS contamination; a Fire Fighter Training pit where aqueous film-forming foam concentrates (AFFF) may have been used to extinguish training fires is an area of particular focus. Findings of this site investigation will facilitate an action plan with the Army regarding further detection, remediation, and financial reimbursement to the water utility for mitigation and related costs. Ultimately, water treatment may be necessary; however, at this time none of the active production wells have PFAS compounds present above the EPA Advisory Level.

Benefit: EGGI/GZA’s technical expertise with PFAS contamination and public groundwater supplies was integral to the utility’s proactive detection of PFAS contamination in the groundwater resources at this site and preventing these emerging contaminates from further adversely impacting the local groundwater supply. EGGI/GZA’s experience as a liaison between a utility and responsible parties will serve to facilitate the project’s progress.