JOINT BASE SAN ANTONIO-LACKLAND, Texas - After two months of operation, an expanded pump and treat system is already helping the Air Force reduce perfluorooctane sulfonate and perfluorooctanoic acid, or PFOS/PFOA, in groundwater migrating to Clark's Marsh from the former Wurtsmith Air Force Base fire training area.
Initial sampling results shows the expanded system is effectively treating the increased flow of PFOS/PFOA impacted groundwater to concentrations below the discharge limits established by the Michigan Department of Environment, Great Lakes, and Energy, said Steve Willis, BRAC Environmental Coordinator for the former Wurtsmith AFB. The expansion of the previous Air Force-installed system became operational in August.
"While the Air Force investigates the extent of the PFOS/PFOA releases at the training area and works toward choosing a final plan for cleaning up those releases, this action is intercepting and treating some of the highest concentrations of PFOS/PFOA at the site," Willis said.
The $4.7 million project, which was accomplished as an interim remedial action, expands an existing treatment system with six additional groundwater extraction wells. It also adds three granular activated carbon, or GAC, units to pre-treat extracted groundwater, and increases system treatment capacity from approximately 240 to 445 gallons per minute.
The fire training area, designated site FT002, is located near the southwest corner of the former base and was the firefighting training area for the base from 1958 through 1991.
The Air Force is closely monitoring the system in the first 90 days of operation to ensure that extracted groundwater has been effectively treated to remove PFOS/PFOA to below the 2016 Substantive Requirements Document, or SRD, discharge limits before it is discharged to the shallow groundwater via a series of infiltration trenches. The 2016 SRD discharge limits were set by Michigan's Department of Environment, Great Lakes and Energy (which in 2016 was named the Michigan Department of Environmental Quality). The SRD maximum discharge limits are 20 nanograms per liter for PFOS and 40 nanograms per liter for PFOA.
"We have selected an interim solution with the full intention of incorporating it into our long term and permanent cleanup plans at Wurtsmith. We will continue to monitor these systems to ensure long term success of these efforts" said Dan Medina, Interim Base Realignment and Closure Program Management Division Chief.
The Air Force is conducting a remedial investigation, under the federal Comprehensive Environmental Response, Compensation, and Liability Act process, to determine the nature and extent of PFOS/PFOA contamination associated with historical operations at the former base. While the remedial investigation continues, this interim remedial action will reduce the migration of the contaminant plume, thereby reducing the concentrations of PFOS and PFOA migrating into Clark's Marsh from the fire training area.
Additionally, the Air Force is researching technologies that could be viable at Wurtsmith so that we may initiate pilot studies and determine which technologies should be considered in the feasibility study.
For more information please visit the administrative record file at: https://ar.afcec-cloud.af.mil