Naval Auxiliary Landing Field (NALF) Fentress is an outlying field under the operational control of Naval Air Station (NAS) Oceana. NALF Fentress is located in Chesapeake, Virginia, approximately 7 miles southwest of NAS Oceana. Established in 1943, the installation encompasses just over 2,500 acres and approximately 8,700 acres in restrictive easements. The facility is primarily used by squadrons stationed at NAS Oceana or Naval Station Norfolk Chambers Field for field carrier landing practice operations (Malcolm Pirnie, 2008).
Per- and polyfluoroalkyl substances (PFAS) are a family of thousands of different chemicals that have been widely used in industrial and consumer products since the 1950s. PFAS are man-made and have been used in many household and industrial products because of their stain- and water-repellent properties. PFAS are now present virtually everywhere in the world. Once these compounds are released, they break down very slowly.
In May 2016, the United States Environmental Protection Agency (EPA) issued lifetime drinking water health advisories of 70 parts per trillion (ppt), individually or combined, for two commonly used and studied PFAS, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Health advisories are not enforceable, and are not regulatory levels; rather, they are levels that provide Americans, including sensitive populations, with a margin of protection from a lifetime of exposure.
In June 2016 the Department of the Navy developed a proactive policy to investigate past releases of PFAS at installations nationwide, and has used the 2016 health advisories for PFOA and PFOS to determine an acceptable level of PFOA and PFOS in drinking water. The most common activity that could have resulted in the historical release of PFOA, PFOS, and other PFAS to the environment at Navy installations is the use of firefighting foam (specifically, aqueous film-forming foam, or AFFF) for testing, training, firefighting, and other life-saving emergency responses. Because of this historical use, there is potential for PFOA, PFOS, and other PFAS to be in the groundwater on base, and also be present in nearby drinking water wells that are located in the direction that the groundwater flows away from the base. Current formulations that meet military specifications contain lower concentrations of PFOA and PFOS than many historical AFFF formulations. Further, the Navy is working to identify a new formulation for firefighting foam that does not contain PFOA and PFOS but will still meet critical fire suppression, and ultimately lifesaving, properties. Until this formulation is approved, and products are available, the Navy has taken steps to prevent or minimize additional release of firefighting foam to the environment.
On June 15, 2022, the EPA issued new interim drinking water health advisories for PFOA and PFOS. The Navy is currently evaluating how to address the EPA’s new health advisories. The Navy is coordinating with the Department of Defense to develop a consistent approach, to include proactive engagement with communities and the appropriate Congressional delegations.
Areas for PFAS Drinking Water Well Sampling
The Navy has sampled 68 private drinking water wells from 64 parcels within a designated area near NAS Oceana for certain PFAS.
Because of the historical use of AFFF at NALF Fentress, PFOA, PFOS, and other PFAS are present in the groundwater at the installation as well as in some private drinking water wells located in the direction that the groundwater flows away from the installation. The designated sampling area, as shown in Figure 1, was selected because of the proximity to NALF Fentress and the general groundwater flow direction.
NALF Fentress Actions Based on Drinking Water Sampling Results
The Navy has conducted drinking water sampling for certain PFAS in drinking water wells in the vicinity of NALF Fentress since February 2016. Table 1 summarizes the drinking water sampling results to date. The Navy continues to evaluate results as new data are collected and will expand the sampling area and conduct actions as needed. When PFOS/PFOA was not detected or was measured at or below 70 ppt in a drinking water sample, no additional action was taken.
Table 1. NALF Fentress – Off-Base Drinking Water Results as of November 7, 2022
|Number of Wells Sampled
||Number of wells with no detections of PFOA or PFOS
||Number of wells with detections of PFOA and/or PFOS below 70 ppt
||Number of wells with detections of PFOA and/or PFOS above 70 ppt
Based on the detections of PFOA/PFOS above 70 ppt in drinking water from off-installation drinking water wells, an emergency response action was implemented. Under the emergency response action, bottled water was provided and continues to be provided to the residents whose drinking water contained PFOA/PFOS above 70 ppt.
Following implementation of the emergency response action for off-installation drinking water, a pilot test was implemented that consisted of the installation and operation of point of entry granular activated carbon (GAC) systems at the seven drinking water wells with detections of PFOA/PFOS above 70 ppt. Each point of entry GAC system was installed downstream from an existing pressure tank (if present), and water was routed through a 25-micrometer cartridge pre-filter, flowmeter, and two GAC vessels, existing water softening systems (if present), and an ultraviolet disinfection system before flowing back into existing plumbing. An Engineering Evaluation and Cost Analysis (EE/CA) for a non-time-critical removal action (NTCRA) to address PFAS in the on-installation potable water system and off-installation private drinking water within and near NALF Fentress was finalized in November 2018. The EE/CA evaluated alternatives to address only current exposure potential to drinking water impacted by PFOA/PFOS above 70 ppt. Based on the evaluation of the alternatives, connection to city water was recommended. In December 2018, an Action Memorandum for the EE/CA documented the approval for the NTCRA to address PFAS in the on-installation potable water system and off-installation private drinking water within and near NALF Fentress. The city waterline extension is planned in Fiscal Year 2025.
NALF Fentress Drinking Water Investigation Documents
USEPA. 2014. Provisional Peer-Reviewed Toxicity Values for Perfluorobutane Sulfonate (CASRN 375-73-5) and Related Compound Potassium Perfluorobutane Sulfonate (CASRN 29420-49-3). Superfund Health Risk Technical Support Center, National Center for Environmental Assessment, Office of Research and Development. July.
USEPA. 2016a. Drinking Water Health Advisory for Perfluorooctanoic Acid (PFOA). USEPA 822-R-16-005. Office of Water. May.
USEPA. 2016b. Drinking Water Health Advisory for Perfluorooctane Sulfonate (PFOS). USEPA 822-R-16-004. Office of Water. May.
USEPA. 2019a. Development of the Proposed Unregulated Contaminant Monitoring Rule for the Fifth Monitoring Cycle (UCMR 5): Public Meeting and Webinar. Held July 16, 2019. USEPA, Office of Ground Water and Drinking Water. July.
USEPA. 2019b. EPA’s Per- and Polyfluoroalkyl Substances (PFAS) Action Plan. Office of Water. February.
USEPA. 2019c. Interim Recommendations to Address Groundwater Contaminated with Perfluorooctanoic Acid and Perfluorooctanesulfonate. Office of Land and Emergency Management. December.
USEPA. 2020. EPA PFAS Action Plan: Program Update February 2020. Office of Water. February.