Marine Corps Air Station Beaufort

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Last updated: 10 March 2026

The Navy and Marine Corps are requesting property owner permission to address per- and polyfluoroalkyl substances, or PFAS, in private drinking water wells near Marine Corps Air Station Beaufort and conduct additional sampling of certain private drinking water wells.

Welcome to the Navy and Marine Corps page for PFAS at MCAS Beaufort

Here you will find information about:

• What are PFAS and how have PFAS been released to the environment at MCAS Beaufort?

• PFAS Releases at MCAS Beaufort

• Ongoing PFAS Investigation and Next Steps

• Private Drinking Water Well Sampling near MCAS Beaufort

  • 2022 - 2023 Private Drinking Water Well Sampling near MCAS Beaufort

  • 2025 Private Drinking Water Well Sampling near MCAS Beaufort

• Actions Based on Private Drinking Water Sampling Results

• Documents related to the Private Drinking Water Well Sampling near MCAS Beaufort

• Links for more information

Introduction

Per- and polyfluoroalkyl substances (PFAS) are a family of thousands of different chemicals that have been used since the 1950s in many household and industrial products because of their stain- and water-repellent properties. PFAS are now present virtually everywhere in the world because of the large amounts that have been manufactured and used. Once these compounds are released, many of them tend to stay in the environment for a very long time. The Navy, Marine Corps, and Department of War (DoW), also known as the Department of Defense (DoD), have developed policies to address past releases of PFAS at installations nationwide.

The most common activity that could have resulted in the historical release of PFAS to the environment at Marine Corps Air Station (MCAS) Beaufort (Figure 1) 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, PFAS are present in the groundwater at MCAS Beaufort and have been detected in nearby drinking water wells that are located in the direction that groundwater flows away from MCAS Beaufort.

On April 26, 2024, the United States Environmental Protection Agency (EPA) published a final National Primary Drinking Water Regulation (NPDWR) establishing nationwide drinking water standards for certain PFAS under the Safe Drinking Water Act. The regulation applies to public drinking water systems. Operators of public drinking water systems regulated by the NPDWR have until April 2029 to meet these standards. In September 2024, DoW published “Prioritization of Department of Defense Cleanup Actions to Implement the Federal Drinking Water Standards for Per- and Polyfluoroalkyl Substances under the Defense Environmental Restoration Program,” which describes DoW’s plans to incorporate the EPA’s drinking water regulations into DoW’s ongoing PFAS cleanups and prioritize actions to address private drinking water wells with the highest levels of PFAS from DoW activities. Table 1 shows the levels that all of DoW, including the Navy and Marine Corps, is authorized to use to address PFAS in private drinking water wells.

Table 1 presents the DoW PFAS Interim Action Levels for Private Drinking Water Wells. The DoW’s September 2024 memorandum can be found here.

These levels are based on current EPA NPDWR levels. If EPA updates applicable requirements, DoW will review and update its policy as appropriate.

Private Drinking Water Well Sampling near MCAS Beaufort

Certain PFAS have been detected in groundwater at MCAS Beaufort and in private drinking water wells above the DoW PFAS Interim Action Levels for Private Drinking Water Wells. The Navy and Marine Corps continue to collect additional information about groundwater flow at MCAS Beaufort through ongoing investigations. Based on the Navy and Marine Corps’ current understanding of groundwater flow at MCAS Beaufort, an expanded sampling area was established 1 mile in the direction that groundwater flows away from on base locations with detections at or above the DoW PFAS Interim Action Levels for Private Drinking Water Wells and ½ mile in the direction that groundwater flows away from off-base private drinking water wells with detections at or above the DoW PFAS Interim Action Levels for Private Drinking Water Wells (Figure 2).

Additional private drinking water well sampling occurred near MCAS Beaufort beginning in August 2025. The samples were sent to an accredited, independent laboratory. The laboratory analyzed for the presence of certain PFAS according to EPA-approved methods. The laboratory then provided the Navy and Marine Corps with preliminary results, after which the preliminary results were validated by an independent third-party for quality assurance. Once the results were validated, they were provided to property owners and tenants, approximately 3 months after sampling. Table 2 presents the results of all private drinking water well sampling to date.

2022 - 2023 Private Drinking Water Well Sampling

Between 2022 and 2023, the Navy and Marine Corps sampled 18 private drinking water wells based on information that was available at that time about potential PFAS releases at MCAS Beaufort. The 2022 - 2023 sampling area, shown in Figure 2, was established 1 mile in the direction that groundwater flows away from the release areas shown in Figure 4. Table 2 provides a summary of the results of the sampling. Table 3 presents the 2022 – 2023 PFAS detections. There were no detections of PFOA and/or PFOS above 70 ppt.

The Navy and Marine Corps have re-evaluated the 2022 - 2023 off-base private drinking water well results using the current DoW PFAS Interim Action Levels for Private Drinking Water Wells (Table 1) and new on base groundwater flow information. One (1) private drinking water well near MCAS Beaufort contains PFAS at or above these levels. The Navy and Marine Corps have provided alternative water at this property.

¹ = PFAS were not detected in 12 samples from the 2022 – 2023 Private Drinking Water Well Sampling.
Hazard Index. Calculated for HFPO-DA, PFBS, PFNA, and PFHxS when two or more of these compounds are detected in the sample. Calculated per EPA recommendations (Maximum Contaminant Level Goals (MCLGs) for Three Individual Per- and Polyfluoroalkyl Substances (PFAS) and a Mixture of Four PFAS, 2024) as follows:

PFOA+PFOS is only calculated when both were detected.
Hazard Index is only calculated when two or more of HFPO-DA, PFBS, PFNA, and PFHxS were detected.
J = laboratory estimated value
ppt = parts per trillion

2025 Private Drinking Water Well Sampling

In response to a September 2024 DoW policy on prioritizing PFAS cleanup, the Navy and Marine Corps re-evaluated existing data. This led to an expansion of the sampling area in 2025, and 26 private drinking water wells were sampled within this new, larger boundary (Figure 2). The 2025 sampling area, shown in Figure 2, extended 1-mile downgradient from on base locations with detections at or above the DoW PFAS Interim Action Levels for Private Drinking Water Wells and ½ mile in the direction that groundwater flows away from off-base private drinking water wells with detections at or above the DoW PFAS Interim Action Levels for Private Drinking Water Wells. Table 2 provides a summary of the results of the sampling. Table 4 presents the 2025 PFAS detections. One (1) private drinking water well sampled in 2025 near MCAS Beaufort contains PFAS at or above the action levels. The Navy and Marine Corps have provided alternative water at this property and are working with the property owner to implement an enduring solution.

The Navy and Marine Corps evaluated an area extending ½ mile from the off-base private drinking water well that contains PFAS at or above the action levels to check for additional private drinking water wells. No additional private drinking water wells were identified; therefore, the sampling area was not expanded beyond the areas identified in Figure 2.

¹ = PFAS were not detected in 21 samples from the 2025 Private Drinking Water Well Sampling.
Hazard Index. Calculated for HFPO-DA, PFBS, PFNA, and PFHxS when two or more of these compounds are detected in the sample. Calculated per EPA recommendations (Maximum Contaminant Level Goals (MCLGs) for Three Individual Per- and Polyfluoroalkyl Substances (PFAS) and a Mixture of Four PFAS, 2024) as follows:

PFOA+PFOS is only calculated when both were detected.
Hazard Index is only calculated when two or more of HFPO-DA, PFBS, PFNA, and PFHxS were detected.
J = laboratory estimated value
ppt = parts per trillion

At this time, the private drinking water well sampling is considered complete. However, property owners with a drinking water well within the sampling areas may still call 843-228-7370 to schedule a sampling appointment. If you have questions about the drinking water well sampling, please email: BFRT_NREAO@usmc.mil or call and leave a detailed message at 843-228-7370. A Navy and Marine Corps representative will return your call.

Actions Based on Private Drinking Water Sampling Results

The preliminary results from the private drinking water well sampling are expected approximately 30 days after collecting the samples. Upon receipt of the preliminary results, the Navy and Marine Corps will compare the preliminary results to the DoW PFAS Interim Action Levels for Private Drinking Water Wells (Table 1) and notify property owners and tenants (if present) of their drinking water results and any follow-up actions, if needed.

The next steps are then determined based on the results, as shown in Figure 3.

Figure 3. Actions Based on Private Drinking Water Sampling Results

The Navy and Marine Corps will address PFAS in private drinking water wells in keeping with the DoW policy:

PFAS at or above the DoW PFAS Interim Actions Levels for Private Drinking Water Wells (Table 1). The Navy and Marine Corps will work with property owners to provide alternative water as soon as possible. Options for alternative water may include connection to public water or installation of a drinking water treatment system. For any drinking water wells with PFOA and PFOS, individually or combined, above 70 ppt, the Navy and Marine Corps may provide bottled water for drinking and cooking to property owners or tenants until an alternative water source is provided.

PFAS below the DoW PFAS Interim Action Levels for Private Drinking Water Wells (Table 1). For final remedial actions, the Navy and Marine Corps will address drinking water down to EPA NPDWR or background levels in accordance with Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) requirements.

Identification of PFAS Releases at MCAS Beaufort

The Navy and Marine Corps finalized a PFAS Preliminary Assessment (PA) and PA Addendum in 2020 and 2023, respectively. The PA and PA Addendum identified areas where releases of PFAS may have occurred. Based on the results of the PFAS PA and PA Addendum, the Navy and Marine Corps completed a PFAS Site Inspection (SI). Sample collection and analysis of groundwater and soil were conducted from December 2021 to November 2022. PFAS were found in soil and groundwater at MCAS Beaufort. The PFAS release areas investigated at MCAS Beaufort are listed below in Table 5 and shown on Figure 4. Remedial investigations are ongoing at the areas of interest indicated in Table 5.

The Navy and Marine Corps will continue investigating PFAS at MCAS Beaufort following the CERCLA process and will evaluate if actions are needed. MCAS Beaufort’s sites are currently in the Remedial Investigation (RI) phase of the CERCLA process. To find out more about all of the environmental investigations at MCAS Beaufort, visit MCAS Beaufort Administrative Record. Additionally, this site will continue to be updated as conditions change.

* = Ongoing remedial investigation
SWMU = Solid Waste Management Unit

PFAS Investigation at MCAS Beaufort and Next Steps

The Navy and Marine Corps will continue investigating PFAS at MCAS Beaufort following the CERCLA process and will evaluate if actions are needed. To find out more about all of the environmental investigations at MCAS Beaufort, visit MCAS Beaufort Administrative Record.

The CERCLA process, as depicted in Figure 5, provides a consistent, systematic framework for investigating and cleaning up environmental releases. This approach ensures compliance with federal requirements and protects human health and the environment. Collaboration with regulatory agencies, communities, and other stakeholders is maintained throughout to promote transparency and informed decision-making.

Figure 5. CERCLA Process

MCAS Beaufort is currently in the RI portion of the CERCLA process. This phase involves gathering detailed information about site conditions to define the nature and extent of on-Base PFAS releases. The data collected will support the evaluation of cleanup options. Figure 6 depicts the PFAS Environmental Cleanup Process.

Figure 6. PFAS Environmental Cleanup Process

MCAS Beaufort Private Drinking Water Well Sampling Documents

Private Drinking Water Well Sampling Fact Sheet

Private Drinking Water Well Sampling Initial Notification Letter

Drinking Water Well Questionnaire

Right of Entry Agreement for Sampling of Drinking Water Well(s)

Frequently Asked Questions Drinking Water Sampling for PFAS

Within Sampling Area, but No Private Drinking Water Well Postcard

Postcard to Tenants

Public Notice of Action Memorandum

Action Memorandum

Additional Documents

PFAS Preliminary Assessment

PFAS Preliminary Assessment Addendum

Site Inspection for PFAS

USEPA’s MCLGs for Three Individual PFAS and a Mixture of Four PFAS

ATSDR – PFAS Overview

ATSDR – PFAS Health Effects

ATSDR Per- and Polyfluoroalkyl Substances (PFAS) Frequently Asked Questions

ATSDR – PFAS and Breastfeeding

Links

ATSDR PFAS website

DoW PFAS website

EPA PFAS website

MCAS Beaufort Administrative Record

Contact Us

MCAS Beaufort
Natural Resources and Environmental Affairs Office
843-228-7370
BFRT_NREAO@usmc.mil