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).
Areas for PFAS Drinking Water Well Sampling
The Navy has sampled 65 private drinking water wells from 59 parcels within a designated area near NAS Oceana for certain per- and polyfluoroalkyl substances, commonly known as PFAS. PFAS are a family of thousands of different chemicals which have been widely used in industrial and consumer products since the 1950s. The Navy developed a policy to address past releases of PFAS at installations nationwide, as several PFAS are now of emerging public health concern to the Navy, U.S. Environmental Protection Agency (USEPA), state regulatory agencies, and the general public. Although the USEPA does not currently have enforceable drinking water standards for PFAS, the USEPA has issued a drinking water lifetime health advisory for two commonly used and studied PFAS, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA).
The most common Navy activity that could have resulted in the historical release of PFOS, PFOA, and other PFAS to the environment is the use of firefighting foam (specifically certain types of aqueous film-forming foam, or AFFF) for testing, training, firefighting, and other lifesaving emergency responses. Because of this historical use, PFOS, PFOA, 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
Due to the historical operations at NALF Fentress that included the use of AFFF, the Navy has conducted drinking water sampling for certain PFAS in drinking water wells in the vicinity of NALF Fentress since February 2016. When PFOS/PFOA have been found at or below the USEPA lifetime health advisory level of 70 parts per trillion (ppt) in a drinking water sample, no additional action has been taken. 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.
|Table 1. NALF Fentress – Results as of February 2020|
|Number of Drinking Water Wells Tested||Number of Drinking Water Wells above the lifetime health advisory||Number of Drinking Water Wells below the lifetime health advisory||Number of drinking water wells with no detections|
Based on the findings of the off-base drinking water well sampling, 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 exceeded the USEPA lifetime health advisory. Following implementation of the emergency response action for off-base 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 exceedances. 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-base potable water system and off-base 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 contaminated with PFAS at levels greater than the USEPA lifetime health advisory. 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-base potable water system and off-base private drinking water within and near NALF Fentress.
General Use of PFAS
The chemical properties of PFAS make them useful for many commercial products because they are heat resistant and can repel oil, grease, and water. PFAS have been manufactured for use in a wide variety of products including firefighting foam, nonstick cookware, fiber and fabric stain protection, food packaging, and personal care products. The pervasive use of PFAS in commercial and industrial products has led to the discovery of PFAS in soil, air, and groundwater worldwide.
Key PFAS Sources at Naval Installations
PFAS have been used in a variety of military applications, including as a component of aqueous film forming foam (AFFF), which was routinely used at firefighting training areas and firefighting equipment test areas. In addition, current and historical AFFF storage and transfer areas are of potential concern for release to the environment. As such, identification of areas where AFFF was released to the environment, either as repeated small releases or as a significant one-time release, is key to determining potential PFAS sources to environmental media.
PFAS from AFFF used in firefighting, firefighting training, and fire suppression systems are considered to have the greatest potential for release of PFAS to the environment in terms of mass and concentration at Navy installations. Other potential sources of PFAS to the environment include operations wastes (for example, from chromium electroplating), historical onsite land disposal areas and landfills of PFAS-containing materials, and wastewater treatment sludges and effluents. Areas of interest for this PFAS PA include those where AFFF may have been applied, released, or stored. These include current and former fire-training areas, equipment test and cleanout areas, buildings with firefighting infrastructure (for example, hangars, AFFF storage and handling areas, and pump houses), unplanned release areas (such as crash sites), and fire suppression systems located at fuel storage area(s).
PFAS in the Environment
PFAS are a class of anthropogenic compounds characterized by carbon chains of varying lengths containing carbon-fluorine bonds. The strong electronegative force of the carbon-fluorine bond requires a large amount of energy to break, which makes PFAS extremely resistant to biodegradation, photo-oxidation, direct photolysis, and hydrolysis. In addition to their environmental persistence, PFAS are readily soluble in aqueous solution and therefore, have potential for migration to groundwater from soil and with groundwater flow to offsite locations. Because of their persistence and mobility, releases of PFAS to the environment present a unique set of challenges and concerns.
Potential Health Effects
Additional research is needed to more clearly understand the potential health effects that may be caused by exposure to PFAS compounds. To date, there is limited information on only a few of the thousands of PFAS. Currently, there are no Tier 1 toxicity values for any PFAS. Tier 1 toxicity values are the preferred source for toxicity factors in Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and Resource Conservation and Recovery Act assessments.
The USEPA’s Superfund Health Risk Technical Support Center has estimated a Tier 2 noncarcinogenic toxicity value for perfluorobutane sulfonate (PFBS) (USEPA, 2014). The oral reference dose (RfD) is based on kidney effects observed in female rats. Because of a lack of information in the current literature, toxicity values for inhalation exposure and cancer endpoints could not be estimated for PFBS.
USEPA Office of Water developed a RfD for perfluorooctanoic acid (PFOA) that is based on a developmental toxicity study using mice. The critical effects included reduced ossification in parts of the hands and feet and accelerated puberty in male pups following exposure during gestation and lactation (USEPA, 2016a). USEPA Office of Water also determined that PFOA should be classified as “suggestive evidence of carcinogenic potential” and estimated an oral cancer slope factor based on tumor development in rat testes.
USEPA Office of Water estimated a RfD for perfluorooctane sulfonate (PFOS) based on a developmental toxicity study in rats; the critical effect was decreased pup body weight following exposure during gestation and lactation (USEPA, 2016b).
PFOA and PFOS are known to be transmitted to the fetus in cord blood and to the newborn in breast milk. Because the developing fetus and newborn seem particularly sensitive to PFOA- and PFOS-induced toxicity, the RfDs based on developmental effects also are protective of adverse effects in adults.
Identification of PFAS at NALF Fentress
The Navy first evaluated the need for an off-base drinking water investigation at NALF Fentress in early 2016 following sampling of the on-base drinking water in accordance with the 2014 Navy policy (DASN(E), 21 October 2014) that required on-base drinking water sampling for PFAS for bases where groundwater is used as drinking water and PFAS could have been released nearby in the past. During the on-base sampling, monitoring wells at potential PFAS source areas were sampled in addition to the influent and effluent at the on-base drinking water treatment plant. As a result of on-base exceedances of the USEPA lifetime health advisory for PFOA/PFOS, off-base parcels that use groundwater as drinking water were identified within a half-mile radius of exceedances and parcel owners were offered voluntary drinking water sampling. As a result of off-base exceedances of the lifetime health advisory, the sampling area was later expanded within an additional half-mile radius of exceedances. The Navy’s priority with PFAS investigations is to identify and eliminate drinking water exposures above the USEPA’s lifetime health advisory level.
In addition, across the country, the Navy has been conducting base-wide evaluations to identify additional potential PFAS releases. These evaluations are being conducted under the federal cleanup program which meets the requirements of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Following CERCLA, the Navy’s installation-wide assessments are called preliminary assessments/site inspections, and their purpose is to verify, validate, and update the inventory of PFAS release sites aboard the installation for further investigation and cleanup. The recent site investigation addendum at NALF Fentress evaluated additional on-base areas where PFAS-related releases may have occurred. An upcoming preliminary assessment will identify all potential PFAS source areas and recommend further evaluation, as necessary.
PFAS Regulatory Background and History
PFOA Stewardship Program
In 2006, USEPA initiated the 2010/2015 PFOA Stewardship Program in which eight major companies in the United States committed to reduce facility emissions and product contents of PFOA and related chemicals on a global basis by 95 percent no later than 2010, and to work toward eliminating emissions and product content of these chemicals by 2015. All companies have met the program goals. To meet the program goals, most companies stopped the manufacture and import of long-chained PFAS, and then transitioned to alternative chemicals. On January 21, 2015, USEPA proposed a Significant New Use Rule under the Toxic Substances Control Act, to require manufacturers (including importers) of PFOA- and PFOA-related chemicals to notify USEPA at least 90 days before starting or resuming new uses of these chemicals in any process.
Unregulated Contaminant Monitoring Rule (UCMR)
The USEPA issued the Third Unregulated Contaminant Monitoring Rule (UCMR3)* in May 2012. The UCMR3 required monitoring, between 2013 and 2015, for 30 substances at all large public water systems (PWSs) serving more than 10,000 people and 800 representative PWSs serving 10,000 or fewer people. Six PFAS compounds were included in the UCMR3 contaminant list. Of these 6 PFAS, USEPA issued health advisory levels for only two, PFOA and PFOS. The UCMR3 results found these two chemicals were present in less than 1 percent of the nearly 5,000 public water systems that sampled under UCMR3.
In December 2016, USEPA issued the Fourth Unregulated Contaminant Monitoring Rule (UCMR4). UCMR4 requires all large PWSs serving more than 10,000 people and 800 representative PWSs serving 10,000 or fewer people to sample for 30 chemicals between 2018 and 2020. There are no PFAS included on the UCMR4 list of contaminants that require sampling and analysis.
USEPA is currently proposing development of a fifth UCMR (UCMR5), it is anticipated that a proposal for the rule will be developed in summer 2020 and the final rule is expected to be released in late 2021. It is currently unknown whether PFAS will be included as part of UCMR5; however, several PFAS have been proposed for inclusion (USEPA, 2019).
* The 1996 Safe Drinking Water Act amendments require that once every 5 years, USEPA issue a new list of no more than 30 unregulated contaminants to be monitored by PWSs.
USEPA Health Advisories
In May 2016, the USEPA Office of Water issued a drinking water Lifetime Health Advisory for PFOA and PFOS. Health advisories are not enforceable, regulatory levels; rather they are levels that would provide a margin of protection from a lifetime of exposure to PFOA and PFOS from drinking water to receptors that include sensitive populations. The health advisory is 70 parts per trillion (ppt) for PFOA and 70 ppt for PFOS. When both PFOA and PFOS are found in drinking water, the combined concentrations of PFOA and PFOS should be compared with the 70 ppt health advisory level.
USEPA Action Plan
In February 2019, the USEPA issued an action plan outlining the steps the agency is taking to address PFAS and to protect public health (USEPA, 2019). The action plan identifies USEPA-led short-term actions, longer-term research, and potential regulatory approaches designed to reduce the risks associated with PFAS in the environment. The action plan notes that USEPA plans to propose a national drinking water regulatory determination for PFOA and PFOS and include PFAS analysis in the next UCMR monitoring cycle. Other steps include further research into improving analytical methods, understanding remediation options, and obtaining more information about the potential toxicity of a broader set of PFAS, along with numerous additional actions. An update to the Action Plan was issued by USEPA in February 2020.
State-specific Action Levels
Virginia has not established any state-specific action levels for PFAS.
Navy and DoD Policy
DASN (EI&E) Policy Memorandum, October 21, 2014
Because of Navy releases impacting PWSs tested under the UCMR3, the Navy issued a policy in October 2014, requiring on-Base drinking water sampling for PFOA and PFOS for bases where groundwater was used as drinking water and PFAS could have been released nearby in the past. Installations that were not required to sample finished drinking water under UCMR3 that produce drinking water from on-installation groundwater sources and have an identified or suspected PFAS release within approximately 1-mile upgradient to the drinking water source were required to sample their finished drinking water by December 2015.
Chief of Naval Operations Policy Memo, September 14, 2015
This policy memo largely echoed the requirements laid out in the October 2014 DASN (E) policy memo. However, this memo specified that if levels of PFOS and/or PFOA in drinking water exceeded the current-at-the-time USEPA health advisory (that is, 2009 provisional short-term health advisories), then alternative drinking water must be supplied until the PFOA and/or PFOS levels were reduced to below the USEPA health advisory.
Similar to the October 2014 DASN (E) policy memo, this memo relates to testing on-base drinking water. However, this memo also specified that if levels of PFOS and/or PFOA in drinking water exceeded the then current USEPA health advisory (i.e., the 2009 provisional short-term health advisories), then alternative drinking water must be supplied until the PFOA and/or PFOS levels were reduced to below the USEPA health advisories.
Office of the Assistant Secretary of Defense (ASD) Policy Memo, June 10, 2016
This DoD policy memo specified that decisions regarding drinking water should be based on lifetime health advisories issued by the USEPA Office of Water in May 2016, rather than the now outdated provisional short-term health advisories in 2009.
DASN (E) Policy Memo, June 14, 2016
This policy expanded the sampling of PFOA and PFOS at all Navy installations, where such sampling was not previously completed under USEPA’s UCMR3 or the Navy’s October 2014 policy. This memo also specified that, for instance, where drinking water from an installation is purchased from a public water system, but was not tested under UCMR3, that the installation must sample the finished drinking water to comply with this policy. Additionally, this policy included reporting requirements to the DASN (E) office for all PFOA and/or PFOS in drinking water results.
DASN (E) Policy Memo, June 17, 2016
This policy defines the Navy’s intention to remove, dispose, and replace legacy AFFF that contains PFOS and/or PFOA, once environmentally suitable substitutes are identified and certified to meet MIL-SPEC requirements. This policy directs the following actions be taken until suitable replacements are certified:
- Immediately cease the uncontrolled environmental release of AFFF for shoreside installations, with the exception of emergency responses.
- Update and implement Navy and Marine Corps firefighting system requirements, as needed, to ensure fire and emergency service vehicles and equipment at Navy installations and facilities are tested and certified in a manner that does not allow the release of AFFF to the environment.
- By the end of Fiscal Year 2017 (FY17), remove and dispose of uninstalled PFOS-containing AFFF in drums and cans from local stored supplies for shore installations and ships to prevent future environmental releases.
DASN (E) Policy Memo, June 20, 2016
This policy required the Navy to identify and prioritize sites for investigation if drinking water resources, on- or off-installation, are thought to be vulnerable to PFAS contamination from past Navy and Marine Corps PFAS releases. Sites with drinking water sources within 1-mile downgradient from known or potential releases of PFAS were assigned the highest priority. This policy directed the sampling of off-Base drinking water at these high priority (Priority 1) sites within FY17.
The primary mechanism to identify potential PFAS release sites and areas of concern, was review of Environmental Restoration (ER), Navy records. To ensure that all potential PFAS release mechanisms were identified, installations were directed to review installations to identify areas that are not already part of the ER, Navy program. The Navy has completed the sampling for all off-base potentially impacted drinking water sources that were identified as a result of this policy and currently known exposure have been addressed.
ASD Guidance Memo, October 15, 2019
A 15 October 2019 guidance memorandum provided clarification of toxicity values for PFOA and PFOS that can be used to estimate screening levels used in the CERCLA program to determine if further investigation is warranted or if a site can proceed to site closeout.
NALF Fentress Drinking Water Investigation Documents
NALF Fentress Final Sampling and Analysis Plan, Basewide Perfluorinated Compound Site Investigation (August 2016)
NALF Fentress Final Basewide Per- and Polyfluoroalkyl Compound Site Inspection (October 2018)
NALF Fentress Ongoing PFAS Investigation Public Meeting and EE/CA for Drinking Water Public Notices (October 2018)
NALF Fentress EE/CA for Drinking Water (November 2018)
NALF Fentress EE/CA for Drinking Water Action Memorandum (April 2019)
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. 2019. 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.