FINAL

Site Inspection Report 

Salisbury Army Aviation Support 

Facility #2, North Carolina

Perfluorooctanesulfonic Acid (PFOS) and 

Perfluorooctanoic Acid (PFOA) Impacted Sites

ARNG Installations, Nationwide

May 2022

Prepared for:

Army National Guard Bureau

111 S. George Mason Drive

Arlington, VA 22204

UNCLASSIFIED
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Table of Contents

Executive Summary ................................................................................................................ES-1

1. Introduction ....................................................................................................................1-1

1.1 Project Authorization...............................................................................................1-1

1.2 SI Purpose ..............................................................................................................1-1

2. Facility Background........................................................................................................2-1

2.1 Facility Location and Description ............................................................................2-1

2.2 Facility Environmental Setting.................................................................................2-1

2.2.1 Geology ........................................................................................................2-1

2.2.2 Hydrogeology ...............................................................................................2-2

2.2.3 Hydrology .....................................................................................................2-3

2.2.4 Climate .........................................................................................................2-3

2.2.5 Current and Future Land Use.......................................................................2-3

2.2.6 Sensitive Habitat and Threatened/ Endangered Species.............................2-4

2.3 History of PFAS Use ...............................................................................................2-4

3. Summary of Areas of Interest.........................................................................................3-1

3.1 AOI 1 Current Aircraft Apron Fire Training Area, Aircraft Apron Fuel Spills, 

Defueling Pad, and Current Firehouse...............................................................3-1

3.2 AOI 2 Former Firehouse #2, Historical Firetruck Washing Area, Former TriMaxTM Demonstration FTA, Wash Rack, Former Firetruck Parking Area, 

and Drainage Swale ...........................................................................................3-1

3.3 AOI 3 Former Firehouse #1, Firetruck Parking (2014-2015), Ornamental 

Firetruck Parking Location (2016), and Former Live Fire FTA ...........................3-2

3.4 AOI 4 NC HART Training Area................................................................................3-2

4. Project Data Quality Objectives .....................................................................................4-1

4.1 Problem Statement .................................................................................................4-1

4.2 Goals of the Study ..................................................................................................4-1

4.3 Information Inputs ...................................................................................................4-2

4.4 Study Boundaries ...................................................................................................4-2

4.5 Analytical Approach ................................................................................................4-2

4.6 Data Usability Assessment .....................................................................................4-3

4.6.1 Precision.......................................................................................................4-3

4.6.2 Accuracy.......................................................................................................4-4

4.6.3 Representativeness......................................................................................4-4

4.6.4 Comparability................................................................................................4-6

4.6.5 Completeness...............................................................................................4-6

4.6.6 Sensitivity .....................................................................................................4-6

5. Site Inspection Activities.................................................................................................5-1

5.1 Pre-Investigation Activities......................................................................................5-1

5.1.1 Technical Project Planning ...........................................................................5-1

5.1.2 Utility Clearance ...........................................................................................5-2

5.1.3 Source Water and PFAS Sampling Equipment Acceptability .......................5-2

5.2 Soil Borings and Soil Sampling...............................................................................5-2

5.3 Temporary Well Installation and Groundwater Grab Sampling ...............................5-3

5.4 Permanent Well Installation and Groundwater Sampling .......................................5-4

5.5 Synoptic Water Level Measurements .....................................................................5-5
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5.6 Surveying................................................................................................................5-5

5.7 Investigation-Derived Waste ...................................................................................5-5

5.8 Laboratory Analytical Methods................................................................................5-5

5.9 Deviations from SI QAPP Addendum .....................................................................5-6

6. Site Inspection Results...................................................................................................6-1

6.1 Screening Levels ....................................................................................................6-1

6.2 Soil Physicochemical Analyses...............................................................................6-2

6.3 AOI 1.......................................................................................................................6-2

6.3.1 AOI 1 Soil Analytical Results ........................................................................6-2

6.3.2 AOI 1 Groundwater Analytical Results .........................................................6-2

6.3.3 AOI 1 Conclusions........................................................................................6-3

6.4 AOI 2.......................................................................................................................6-3

6.4.1 AOI 2 Soil Analytical Results ........................................................................6-3

6.4.2 AOI 2 Groundwater Analytical Results .........................................................6-3

6.4.3 AOI 2 Conclusions........................................................................................6-3

6.5 AOI 3.......................................................................................................................6-4

6.5.1 AOI 3 Soil Analytical Results ........................................................................6-4

6.5.2 AOI 3 Groundwater Analytical Results .........................................................6-4

6.5.3 AOI 3 Conclusions........................................................................................6-4

6.6 AOI 4.......................................................................................................................6-5

6.6.1 AOI 4 Soil Analytical Results ........................................................................6-5

6.6.2 AOI 4 Groundwater Analytical Results .........................................................6-5

6.6.3 AOI 4 Conclusions........................................................................................6-5

7. Exposure Pathways .......................................................................................................7-1

7.1 Soil Exposure Pathway...........................................................................................7-1

7.1.1 AOI 1 ............................................................................................................7-1

7.1.2 AOI 2 ............................................................................................................7-2

7.1.3 AOI 3 ............................................................................................................7-2

7.1.4 AOI 4 ............................................................................................................7-2

7.2 Groundwater Exposure Pathway ............................................................................7-2

7.2.1 AOI 1 ............................................................................................................7-3

7.2.2 AOI 2 ............................................................................................................7-3

7.2.3 AOI 3 ............................................................................................................7-3

7.2.4 AOI 4 ............................................................................................................7-3

7.3 Surface Water Sediment Exposure Pathway..........................................................7-3

8. Summary and Outcome .................................................................................................8-1

8.1 SI Activities .............................................................................................................8-1

8.2 SI Goals Evaluation ................................................................................................8-1

8.3 Outcome .................................................................................................................8-2

9. References.....................................................................................................................9-1
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Appendices

Appendix A Data Validation Reports

Appendix B Field Documentation

B1. Logs of Daily Notice of Field Activities

B2. Sampling Forms

B3. Well Development Forms

B4. Field Change Request Forms

B5. Survey Data

B6. Equipment Calibration Daily Logs

Appendix C Photographic Log

Appendix D TPP Meeting Minutes

Appendix E Boring Logs and Well Construction Forms

Appendix F Analytical Results

Appendix G Laboratory Reports

Figures

Figure 2-1 Facility Location

Figure 2-2 Facility Topography

Figure 2-3 Groundwater Features

Figure 2-4 Groundwater Elevations, June 2021

Figure 2-5 Surface Water Features

Figure 3-1 Areas of Interest

Figure 5-1 Site Inspection Sample Locations

Figure 6-1 PFOA Detections in Soil

Figure 6-2 PFOS Detections in Soil

Figure 6-3 PFBS Detections in Soil

Figure 6-4 PFOA, PFOS, and PFBS Detections in Groundwater 

Figure 7-1 Conceptual Site Model, AOI 1, AOI 2, and AOI 3

Figure 7-2 Conceptual Site Model, AOI 4

Tables

Table ES-1 Screening Levels (Soil and Groundwater)

Table ES-2 Summary of Site Inspection Findings

Table ES-3 Site Inspection Recommendations

Table 5-1 Site Inspection Samples by Medium

Table 5-2 Soil Boring Depths, Temporary Well Screen Intervals, and Groundwater 

Elevations

Table 5-3 Permanent Monitoring Well Screen Intervals and Groundwater Elevations

Table 6-1 Screening Levels (Soil and Groundwater)

Table 6-2 PFAS Detections in Surface Soil

Table 6-3 PFAS Detections in Shallow Subsurface Soil

Table 6-4 PFAS Detections in Deep Subsurface Soil

Table 6-5 PFAS Detections in Groundwater

Table 8-1 Summary of Site Inspection Findings

Table 8-2 Site Inspection Recommendations
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Acronyms and Abbreviations

% percent

°F degrees Fahrenheit

μg/kg micrograms per kilogram

6:2 FTS 6:2 Fluorotelomer sulfonic acid

8:2 FTS 8:2 Fluorotelomer sulfonic acid

AASF Army Aviation Support Facility

AECOM AECOM Technical Services, Inc.

AFFF aqueous film forming foam

AOI Area of Interest

ARNG Army National Guard

bgs below ground surface 

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act 

CoC chain of custody

CSM conceptual site model

DA Department of the Army

DoD Department of Defense

DL detection limit

DQI data quality indicator

DQO data quality objective

ELAP Environmental Laboratory Accreditation Program

EM Engineer Manual

FedEx Federal Express

FTA Fire Training Area

HA Health Advisory

HDPE high-density polyethylene 

IDW investigation-derived waste

IIS injection internal standards

ITRC Interstate Technology Regulatory Council

LC/MS/MS liquid chromatography with tandem mass spectrometry

LCS laboratory control spike

LCSD laboratory control spike duplicate

LOQ limit of quantitation

MDL method detection limit

MS matrix spike

MSD matrix spike duplicate

NCARNG North Carolina Army National Guard

NC HART North Carolina Helicopter Aquatic Rescue Team

ND not detected

NELAP National Environmental Laboratory Accreditation Program

NEtFOSAA N-ethyl perfluorooctanesulfonamidoacetic acid

ng/L nanograms per liter

NMeFOSAA N-methyl perfluorooctanesulfonamidoacetic acid

ORP oxidation-reduction potential
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OSD Office of the Secretary of Defense

PA Preliminary Assessment

PFAS per- and polyfluoroalkyl substances

PFBA perfluorobutyrate

PFBS perfluorobutanesulfonic acid

PFDA perfluorodecanoic acid

PFDoA perfluorododecanoic acid

PFHpA perfluoroheptanoic acid

PFHxA perfluorohexanoic acid

PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

PFOA perfluorooctanoic acid

PFOS perfluorooctanesulfonic acid

PFPeA perfluoropentanoic acid

PFTeDA perfluorotetradecanoic acid

PFTrDA perfluorotridecanoic acid

PFUdA perfluoroundecanoic acid

PID photoionization detector

PVC poly-vinyl chloride

QA quality assurance

QAPP Quality Assurance Project Plan

QSM Quality Systems Manual

RI Remedial Investigation

RPD relative percent differences

SI Site Inspection

SL screening level

SOP standard operating procedure

TCRA Time Critical Removal Action

TOC total organic carbon

TPP Technical Project Planning

UCMR 3 Third Unregulated Contaminant Monitoring Rule

US United States

USACE United States Army Corps of Engineers

USCS Unified Soil Classification System

USDA United States Department of Agriculture

USEPA United States Environmental Protection Agency

USFWS United States Fish and Wildlife Service

USGS United States Geological Survey
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Executive Summary

The Army National Guard (ARNG) G9 is performing Preliminary Assessments (PAs) and Site 

Inspections (SIs) at per- and polyfluoroalkyl substances (PFAS)-impacted sites at ARNG facilities 

nationwide. The objective of the SI at each facility is to identify whether there has been a release 

to the environment from the Areas of Interest (AOIs) identified in the PA and determine the 

presence or absence of perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and 

perfluorobutanesulfonic acid (PFBS) at or above screening levels (SLs). An SI was completed at

Salisbury Army Aviation Support Facility (AASF) #2 in Salisbury, North Carolina. Salisbury AASF 

#2 will also be referred to as the “facility” throughout this document.

Salisbury AASF #2 is on the western side of the runway at the Mid-Carolina Regional Airport 

(Rowan County Airport). The facility is in Rowan County, North Carolina, roughly 40 miles 

northeast of Charlotte, North Carolina. The facility includes hangar space, a parking apron, flight

ramp, wash rack, firehouse, armory building, operations and maintenance support buildings, a 

fuel farm, and a taxiway connecting to the airport runway. 

During the PA for PFAS, 15 potential PFAS release areas were identified (AECOM, 2020). PFAScontaining aqueous film forming foam (AFFF) may have been released during fire responses, fire 

training activities, AFFF storage/handling, and cleaning of fire response vehicles. The potential 

PFAS release areas were grouped into four AOIs, which were investigated during the SI. The SI 

field activities were conducted from 7 to 17 June 2021 and included the collection of soil and 

groundwater samples.

To fulfill the project Data Quality Objectives set forth in the approved SI Quality Assurance Project 

Plan (QAPP) Addendum (AECOM, 2021a), samples were collected and analyzed for a subset of 

18 PFAS by liquid chromatography with tandem mass spectrometry compliant with Quality 

Systems Manual 5.3 Table B-15. The 18 PFAS analyzed as part of the ARNG SI program are 

specified in Section 5.7 of this Report. No reportable accidents, exposures or other health & 

safety issues occurred during the execution of the field work.

The Department of Defense (DoD) has adopted a policy to retain facilities in the Comprehensive 

Environmental Response, Compensation, and Liability Act (CERCLA) process based on riskbased SLs for soil and groundwater, as described in a memorandum from the Office of the 

Secretary of Defense (OSD) dated 15 September 2021 (Assistant Secretary of Defense, 2021).

The ARNG program under which this SI was performed follows this DoD policy. Should the 

maximum site concentration for sampled media exceed the SLs established in the OSD 

memorandum and there is a release identified that is likely attributed to ARNG activities, the AOI 

will proceed to the next phase under CERCLA. The SLs established in the OSD memorandum 

apply to three compounds: PFOS, PFOA, and PFBS.

The SLs are presented on Table ES-1 below. All other results presented in this report are 

considered informational in nature and serve as an indication as to whether soil and groundwater

contain or do not contain the 18 PFAS analyzed within the boundaries of the facility.

Sample chemical analytical concentrations were compared against the project SLs as described 

in Table ES-1. A summary of the results of the SI data relative to the SLs is as follows:

• At AOI 1, PFOS in groundwater at the potential release areas exceeded the SL of 40 

nanograms per liter (ng/L) with a maximum concentration of 139 ng/L at location AOI01-04. 

PFOS in groundwater downgradient of AOI 1 also exceeded the USEPA HA SL of 70 ng/L. 

Based on the results of the SI, further evaluation of AOI 1 is warranted in the RI.

• At AOI 2, PFOA and PFOS in groundwater at the potential release areas exceeded the SLs 

of 40 ng/L with maximum concentrations of 85.2 ng/L and 2,700 ng/L, respectively, at 
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location AOI02-MW-1 (existing Rowan County Monitoring Well). PFOA and PFOS in 

groundwater downgradient of AOI 2 also exceeded the individual and combined USEPA HA 

SL of 70 ng/L. Based on the results of the SI, further evaluation of AOI 2 is warranted in the 

RI.

• At AOI 3, PFOA in groundwater at the potential PFAS release areas exceeded the SL of 40 

ng/L, with a concentration of 93.5 ng/L at location AOI03-03. Additionally, PFOS in 

groundwater at the potential PFAS release areas exceeded the SL of 40 ng/L, with a 

concentration of 50.5 ng/L at location PFOA in groundwater at the Ornamental Firetruck 

Parking Location also exceeded the USEPA HA SL of 70 ng/L. AOI03-02. Based on the 

results of the SI, further evaluation of AOI 3 is warranted in the RI. 

• At AOI 4, detected concentrations of PFOA, PFOS, and PFBS in groundwater were below 

SLs. Based on the results of the SI, no further evaluation of AOI 4 is warranted. If screening 

levels are revised in the future, further evaluation of AOI 4 may be required. 

• The detected concentrations of PFOA, PFOS, and PFBS in soil at all AOIs were below the 

SLs. 

Table ES-2 summarizes the SI results for soil and groundwater. Based on the conceptual site 

models (CSMs) developed and revised in light of the SI findings, there is potential for exposure 

to off-facility receptors caused by DoD activities at or adjacent to the facility. 

Table ES-3 summarizes the rationale used to determine if an AOI should be considered for further 

investigation under CERCLA and undergo a Remedial Investigation (RI). Based on the results of 

this SI, further evaluation is warranted in the RI for AOI 1: Southern Portion of the facility, AOI 2: 

Central Portion of the facility, and AOI 3: Northern Portion of the facility.

Table ES-1: Screening Levels (Soil and Groundwater) 

Analyte

Residential

(Soil)

(μg/kg)a,b 

0-2 feet bgs

Industrial/ Commercial 

Composite Worker

(Soil)

(μg/kg)a,b 

2-15 feet bgs

Tap Water

(Groundwater) 

(ng/L)a,b

USEPA HA

(Groundwater 

representative of 

Drinking Water)

(ng/L)b,c

PFOA 130 1,600 40 70

PFOS 130 1,600 40 70

PFBS 1,900 25,000 600 - 

Notes:

a.) Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS, PFOA, PFBS in Groundwater and Soil using 

United States Environmental Protection Agency’s (USEPA’s) Regional Screening Level Calculator. Hazard Quotient (HQ) = 0.1. 15 

September 2021. 

b.) USEPA. 2016a. Drinking Water Health Advisory (HA) for PFOA. Office of Water (4304T). Health and Ecological Criteria Division, 

Washington, DC 20460. USEPA Document Number: 822-R-16-005. May 2016. / USEPA. 2016b. Drinking Water HA for PFOS. Office of 

Water (4304T). Health and Ecological Criteria Division, Washington, DC 20460. USEPA Document Number: 822-R-16-004. May 2016.

c.) USEPA HAs apply to the PFOA and PFOS concentrations individually or combined.

μg/kg= micrograms per kilogram
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Table ES-2: Summary of Site Inspection Findings

AOI Potential PFAS 

Release Area

Soil – 

Source Area

Groundwater – 

Source Area

Groundwater –

Facility Boundary

1 

Southern Portion of 

Salisbury AASF #2 

(Current Aircraft Apron 

FTA, Aircraft Apron Fuel 

Spills, Defueling Pad, and 

Current Firehouse)

2 

Central Portion of 

Salisbury AASF #2 

(Former Firehouse #2, 

Historical Firetruck 

Washing Area, Former 

Tri-Max Demonstration 

FTA, Wash Rack, Former 

Firetruck Parking Area, 

Drainage Swale)

3

Northern Portion of 

Salisbury AASF #2 

(Former Firehouse #1, 

Firetruck Parking, 

Ornamental Firetruck 

Parking Location, Former 

Live Fire FTA

4 NC HART Training Area

Legend:

N/A = not applicable

NC HART = North Carolina Helicopter Aquatic Rescue Team 

= detected; exceedance of the screening levels

= detected; no exceedance of the screening levels

= not detected
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Table ES-3: Site Inspection Recommendations

AOI Description Rationale Future Action

1 

Southern Portion of 

Salisbury AASF #2 

(Current Aircraft 

Apron FTA, Aircraft 

Apron Fuel Spills, 

Defueling Pad, and 

Current Firehouse)

Exceedances of SLs in groundwater at 

potential release areas. No exceedances of 

SLs in soil. 

Proceed to RI 

2 

Central Portion of 

Salisbury AASF #2 

(Former Firehouse 

#2, Historical 

Firetruck Washing 

Area, Former TriMax Demonstration 

FTA, Wash Rack, 

Former Firetruck 

Parking Area, 

Drainage Swale)

Exceedances of SLs in groundwater at 

potential release areas. No exceedances of 

SLs in soil.

Proceed to RI 

3 

Northern Portion of 

Salisbury AASF #2 

(Former Firehouse 

#1, Firetruck 

Parking, Ornamental 

Firetruck Parking 

Location, Former 

Live Fire FTA

Exceedances of SLs in groundwater at 

potential release areas. No exceedances of 

SLs in soil.

Proceed to RI 

4 NC HART Training 

Area

Detections in groundwater but no 

exceedances of SLs. No exceedances of SLs 

in soil.

No further action* 

Notes: 

* If screening levels are revised in the future, further evaluation of AOI 4 may be required.

NC HART = North Carolina Helicopter Aquatic Rescue Team
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1. Introduction

1.1 Project Authorization

The Army National Guard (ARNG) G9 is the lead agency in performing Preliminary Assessments 

(PAs) and Site Inspections (SIs) for Perfluorooctanesulfonic acid (PFOS) and Perfluorooctanoic 

acid (PFOA) at Impacted Sites, ARNG Installations, Nationwide. This work is supported by the 

United States (US) Army Corps of Engineers (USACE) Baltimore District and their contractor, 

AECOM Technical Services, Inc. (AECOM), under Contract Number W912DR-12-D-0014, Task 

Order W912DR17F0192, issued 11 August 2017. The ARNG performed this SI at Salisbury Army 

Aviation Support Facility (AASF) #2 in Salisbury, North Carolina. Salisbury AASF #2 is also

referred to as the “facility” throughout this document.

The SI project elements were performed in compliance with Comprehensive Environmental 

Response, Compensation, and Liability Act (CERCLA; US Environmental Protection Agency 

[USEPA], 1980), as amended, the National Oil and Hazardous Substances Pollution Contingency 

Plan (40 Code of Federal Regulations Part 300; USEPA, 1994), and in compliance with US 

Department of the Army (DA) requirements and guidance for field investigations including specific 

requirements for sampling for PFOA, PFOS, and perfluorobutanesulfonic acid (PFBS), and the 

group of related compounds known in the industry as per- and polyfluoroalkyl substances (PFAS). 

The term PFAS is used throughout this report to encompass all PFAS chemicals being evaluated, 

including PFOA, PFOS, and PFBS, which are the key components of the suspected releases 

being evaluated, and the other 15 related compounds listed in the task order.

1.2 SI Purpose

A PA was performed at Salisbury AASF #2 (AECOM, 2021) that identified 15 potential PFAS 

release areas at the facility, which were grouped into four Areas of Interest (AOIs). The objective 

of the SI is to identify whether there has been a release to the environment from the AOIs and 

determine the presence or absence of PFOA, PFOS, and PFBS at or above screening levels 

(SLs).

As stated in the Federal Facilities Remedial Site Inspection Summary Guide (USEPA, 2005), an 

SI has five goals: 

1. Develop information to potentially eliminate a release from further consideration because 

it is determined that it poses no significant threat to human health or the environment;

2. Determine the potential need for a removal action;

3. Collect or develop data to evaluate potential release;

4. Collect data to better characterize the release for more effective and rapid initiation of a 

Remedial Investigation (RI), if determined necessary; and

5. Collect data to determine whether the release is more than likely the result of activities 

associated with the Department of Defense (DoD).

In addition to the USEPA-identified goals of an SI, the ARNG SI also identifies whether there are 

potential off-facility PFAS sources. 
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2. Facility Background

2.1 Facility Location and Description

Salisbury AASF #2 is on the western side of the runway at the Mid-Carolina Regional Airport 

(Rowan County Airport) (Figure 2-1). The facility is in Rowan County, North Carolina, roughly 40 

miles northeast of Charlotte, North Carolina. Rowan County is bordered by Cabarrus County to 

the south, Davidson County to the east, Davie County to the north, Iredell County to the west, and 

Stanly County to the southeast.

Salisbury AASF #2 was constructed in 1975. The facility includes hangar space, a parking apron, 

flight ramp, wash rack, firehouse, armory building, operations and maintenance support buildings, 

a fuel farm, and a taxiway connecting to the airport runway. The facility parking apron is 32,500 

square yards and accommodates North Carolina ARNG (NCARNG) aircraft. Salisbury AASF #2 

is primarily used for the performance of aircraft and equipment maintenance, aircraft refueling, 

hazardous material storage, aircraft painting, and vehicle and equipment refueling. The 430th

Engineer Firefighting Team, stationed at the facility, provides fire service to the airport Monday 

through Friday (Talbert & Bright, 2011). Additionally, NCARNG has an informal mutual aid 

agreement for emergency response services with Rowan County, the City of Salisbury, and Locke 

Township, although the details of the agreement are unknown. The current property lease issues 

the facility property to the State of North Carolina from Rowan County for National Guard use 

from 2002 to 2099.

2.2 Facility Environmental Setting

Salisbury AASF #2 is in the Piedmont Region of North Carolina, which is characterized by small 

rolling hills. The facility sits at 734 feet above mean sea level surrounded by wooded areas 

(Environmental Data Resources, Inc.TM [

EDRTM], 2019). Topography across the southern portion 

of the facility is generally flat but slopes downward to the south and southwest along the southern 

boundary. In the northern portion of the facility, topography slopes downward, towards the 

northwest.

Roughly 10 percent (%) of the greater airport property is impervious, as it is covered by buildings 

and paved areas such as runways, taxiways, aircraft parking aprons, roadways, and parking lots. 

Unpaved areas across Salisbury AASF #2 are covered by vegetative surfaces, primarily mowed 

grass (Talbert & Bright, 2011). There are no water bodies within the NCARNG property boundary. 

The topography of the facility is shown on Figure 2-2.

2.2.1 Geology

Metamorphic, igneous, and sedimentary rock are found in the Piedmont region of North Carolina, 

with metamorphic rock being the most prevalent (Daniel, 1989); they range in composition from 

felsic to ultramafic. The metamorphic rocks here have been folded and refolded during multiple 

metamorphic and orogenic events. The rocks have also been broken and displaced by numerous 

faults and shearing, which can reach up to miles in length. There are many joints where there are 

rock fractures without displacement; they tend to cluster in groups oriented about one or more 

preferred directions (Daniel, 1989).

Salisbury AASF #2 is on the Charlotte Belt geologic feature. The oldest rocks in this area 

commonly are mafic gneisses, amphibolites, metagabbros, and metavolcanic rocks (Horton and 

Zullo, 1991). These features contain largely plutonic rocks that range in age from Late Proterozoic 

to late Paleozoic. This plutonic complex contains enclaves of metasedimentary and metavolcanic 

rocks that are most abundant toward the flanks (Gair, J.E. et. al., 1986). The older plutonic 
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complex is intruded by middle Paleozoic plutons that range from gabbro and syenite to granite 

and granodiorite, and by late Paleozoic, plutons that are typically porphyritic granite (Gair, J.E. et. 

al, 1986) (Figure 2-3). The soil in this area is categorized as Cecil-Pacolet, gently sloping to steep, 

well-drained upland soils that have a loamy surface layer and a predominantly clayey subsoil (US 

Department of Agriculture [USDA], 1995).

Soil borings completed during the SI found abundant lean clay, sandy lean clay, and clayey sand 

as the dominant lithology of the unconsolidated sediments below Salisbury AASF #2. Samples 

for grain size analyses were collected at three locations, AOI01-01-SB-8-10, AOI02-01-SB-0-2, 

and AOI03-1-SB-15-20, and analyzed via American Society for Testing and Materials (ASTM) 

Method D-422. The results indicate that the soil samples are comprised primarily of silt (44.64% 

to 63.33%) and clay (12.96% to 33.35%). Borings were completed at depths between 20 and 60 

feet below ground surface (bgs). Isolated layers of sand and silty sand were observed, along with 

varying percentages of gravel in some logs. In some borings at AOIs 3 and 4, saprolite and 

weathered bedrock were observed at varying depths. These observations are consistent with the 

understood geology of this region, including weathered metamorphic and igneous bedrock 

underlying fine-grained surficial sediments. Boring logs are presented in Appendix E and grain 

size results are presented in Appendix F.

2.2.2 Hydrogeology

Based on groundwater sampling data from monitoring wells at the closed Rowan County Landfill, 

adjacent to the west of Salisbury AASF #2, groundwater depths in the vicinity of the facility range 

from approximately 4 to 24 feet bgs (Golder Associates NC, Inc., 2018). The nearest US 

Geological Survey (USGS) groundwater information site is an inactive well (USGS 

353819080291701 RO-057) located approximately 2 miles southeast of the facility. Groundwater 

at this location was measured at 40 feet bgs in 1954 (USGS, 2020). 

There are no drinking water wells at Rowan County Airport or Salisbury AASF #2; drinking water

and wastewater are provided by Salisbury-Rowan Utilities. Salisbury-Rowan Utilities sources its 

water from intakes at the confluence of the South Yadkin River and the Yadkin River, located 

approximately 8 miles northeast of the facility (Salisbury-Rowan Utilities, 2019). The North 

Carolina Department of Environmental Quality maintains a database of registered wells in the 

area. The database is only for public water supply wells and does not necessarily include private 

wells. Multiple public water system wells were also indicated to lie in all directions within a 4-mile 

radius of the facility, as shown on Figure 2-3. 

The Unregulated Contaminant Monitoring Rule (UCMR) sampling program was an addition to the 

1996 Safe Drinking Water Act, which requires that the USEPA to issue a new list, every 5 years,

of no more than 30 unregulated contaminants to be monitored by public water systems. PFAS 

were added as part of the Third UCMR (UCMR 3) list. The UCMR 3 dataset indicated that no 

PFAS were detected in a public water system above the Health Advisory (HA) within 20 miles of 

Salisbury AASF #2 (USEPA, 2017a). The HA is 70 parts per trillion for PFOS and PFOA, 

individually or combined. PFAS analyses performed in 2016 had method detection limits (MDLs)

that were higher than currently achievable. Thus, it is possible that low concentrations of PFAS 

were not detected during the UCMR3 but might be detected if analyzed today.

Depths to water measured in June 2021 during the SI ranged from 4.85 feet bgs in AOI03-02 to 

27.71 feet bgs in AOI04-03. Groundwater elevation contours from the SI are presented on Figure 

2-4 and indicate that groundwater at the facility flows generally to the northwest. Groundwater 

contours were drawn using limited available data, and half of the wells were not developed prior 

to gauging. 
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Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 2-3

2.2.3 Hydrology

The Yadkin River is the major water body that flows through Rowan County and makes up the 

border between Rowan, Davie, and Davidson Counties. The river flows in a northwest to 

southeast direction passing to the north and east of the facility. The river is dammed 12 miles east 

of the facility and forms High Rock Lake. 

The Rowan County Airport has multiple drainage outfalls. Outfalls that receive runoff from areas 

where industrial activities have direct discharges to the stormwater system require visual 

inspection and qualitative monitoring by the Airport. There are three such outfalls and they all 

discharge to a channel east of the airfield and Airport Loop Road. This channel flows northward 

feeding into Grants Creek which eventually discharges to Yadkin River (Talbert & Bright, 2011). 

The Yadkin River is the main source of drinking water to the facility.

Salisbury AASF #2 is within the Upper Grants Creek watershed. Regional watersheds and surface 

drainage features within the vicinity of Salisbury AASF #2 are presented in Figure 2-5. 

There are no surface water bodies located within the Salisbury AASF #2 property, but two 

concrete drainage structures, running south to north and east to west, are located within the facility 

property and receive drainage from paved areas north of the aircraft apron. The concrete drainage 

structures lead into a wooded drainage swale that flows north before presumably connecting with 

a tributary of Grants Creek or infiltrating into the ground. Another small stream/drainage swale 

flows west, away from the runway adjacent to the south of the facility, and discharges to Grants 

Creek, which is a tributary of the Yadkin River (US Fish and Wildlife Service [USFWS], 2020). The 

small stream/drainage swale receives drainage from the facility’s aircraft apron and the western 

side of the runway. 

2.2.4 Climate

The climate of Salisbury, North Carolina is humid subtropical characterized by cool to mild winters 

and hot humid summers, with evenly distributed precipitation throughout the year. July is the 

warmest month, with an average max daily temperature of 89.4 degrees Fahrenheit (°F) and an 

average daily low of 68.8 °F. January is the coldest month with an average daily max temperature 

of 50.4°F and an average daily low of 27.7 °F. Salisbury receives an annual precipitation amount 

of 42.03 inches. June is the wettest month and accumulates 4.19 inches, while November is the 

driest month and accumulates 3.07 inches. On average, Salisbury, North Carolina receives 9.9 

inches of snowfall per year. Only one season, 2011-2012, had no measurable snowfall (National 

Oceanic and Atmospheric Administration, 2020).

2.2.5 Current and Future Land Use

Salisbury AASF #2 is currently a controlled access facility and is adjacent to the Mid-Carolina 

Regional Airport, also referred to as Rowan County Airport. The facility supports rotary aircraft 

operations for the NCARNG, and it is currently leased by the state of North Carolina from the 

Rowan County Airport for the duration of 2002 to 2099. The airport is owned and operated by 

Rowan County and provides commercial and general air service to the Carolinas. It is the intent 

of the airport and the NCARNG to expand the size and operations of the facility; however, 

reasonably anticipated future land use is not expected to change from the current land use

described here. 
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Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 2-4

2.2.6 Sensitive Habitat and Threatened/ Endangered Species 

The following birds, plants, mammals, and reptiles are federally endangered, threatened, 

proposed, and/ or are listed as candidate species in Rowan County, North Carolina (USFWS, 

2021). 

• Insects: Monarch butterfly, Danaus plexippus (candidate).

• Flowering plants: Schweinitz’ sunflower, Helianthus schweinitzii (endangered); Georgia

aster, Symphyotrichum georgianum (resolved taxon).

2.3 History of PFAS Use 

Fifteen (15) potential PFAS release areas where aqueous film forming foam (AFFF) may have 

been used or released historically were identified at Salisbury AASF #2 during the PA (AECOM, 

2020). PFAS were potentially released within the boundary of Salisbury AASF #2 during fire 

training exercises, fire emergency responses, AFFF storage/handling activities, and secondary 

release areas. The potential PFAS release areas were grouped into four AOIs based on proximity 

to one another and presumed groundwater flow. A description of each AOI is presented in Section 

3.
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AECOM 3-1

3. Summary of Areas of Interest

This section presents a summary of each potential PFAS release area by AOI. Based on the PA 

findings, 15 potential PFAS release areas were identified at Salisbury AASF #2 and grouped into 

four AOIs (AECOM, 2020). The potential PFAS release areas are shown on Figure 3-1. 

3.1 AOI 1 Current Aircraft Apron Fire Training Area, Aircraft Apron 

Fuel Spills, Defueling Pad, and Current Firehouse

AOI 1 consists of four potential PFAS release areas: the Current Aircraft Apron fire training area 

(FTA), Aircraft Apron Fuel Spills, Defueling Pad, Current Firehouse, and the grassy areas 

surrounding the potential release areas. Based on PA findings, these are areas of known or 

suspected AFFF use and storage. 

Potentially PFAS-laden water was dispensed at the FTA during training events towards the grassy 

area at the southwest corner of the apron and may migrate via runoff towards a drainage swale 

that flows downslope to the west, towards Grants Creek. AFFF has been used in response to 

historical fuel spills as a preventative measure to combat potential fires across the Aircraft Apron 

and Defueling Pad. Tri-MaxTM 30 fire extinguishers have also been stored on the apron at various 

times. The Current Firehouse stores AFFF on firefighting vehicles and previously stored AFFF in 

5-gallon buckets. Tri-MaxTM 30 fire extinguishers are also stored outside, on the southern side of

the current fire house. Additionally, the firefighting vehicles are washed outside the firehouse.

Historically, surface runoff across these areas generally flows west towards Grants Creek via 

sheet flow and the drainage swales on the north and south sides of the aircraft apron. It should 

be noted that the aircraft apron was resurfaced during the summer of 2021 using a recycling 

process which reused existing materials. Based on current surrounding topography the drainage 

patterns are unlikely to change significantly. 

3.2 AOI 2 Former Firehouse #2, Historical Firetruck Washing Area, 

Former Tri-MaxTM Demonstration FTA, Wash Rack, Former 

Firetruck Parking Area, and Drainage Swale

AOI 2 consists of six potential PFAS release areas: the Former Firehouse #2, Historical Firetruck 

Washing Area, Former Tri-MaxTM Demonstration FTA, Wash Rack, Former Firetruck Parking Area, 

Drainage Swale, and grassy areas surrounding the potential release areas. Based on PA findings, 

these are areas of known or suspected AFFF use and storage. It should be noted that there is a 

hangar within AOI 2; however, the building is not equipped with an AFFF fire suppression system 

and is therefore not considered a potential release area. 

Firetrucks containing AFFF and “protein foam” were historically stored at the Former Firehouse 

#2 and washed in the adjacent areas. AFFF concentrate in buckets and Tri-MaxTM units were also 

stored in the Allied Storage Area adjacent to Former Firehouse #2. Although no known PFAS 

releases have occurred at the Wash Rack, its potential use as a wash area may have resulted in 

PFAS being rinsed from vehicles and equipment. Tri-MaxTM units were discharged on the asphaltpaved area between the Current Firehouse and Former Firehouse #2 as part of firefighting 

demonstrations at the former FTA. Demonstrations took place in the 1990s, but the exact 

timeframe of use and the total volume of AFFF released during demonstration events are 

unknown. AFFF, protein-based foam, or PFAS-laden water may have been released from the 

vehicles to the pavement and nearby grassy areas at the Former Firetruck Parking area. 
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Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 3-2

Surface runoff across areas are anticipated to generally flow west, via sheet flow, towards Grants 

Creek. Surface flow reaching National Guard Road may be conveyed to the north, along the road 

surface. A concrete drainage structure on the north side of the AOI also conveys water away from 

the firehouse into the Drainage Swale, located in a wooded area to the north. 

3.3 AOI 3 Former Firehouse #1, Firetruck Parking (2014-2015), 

Ornamental Firetruck Parking Location (2016), and Former Live 

Fire FTA

AOI 3 consists of four potential PFAS release areas: the Former Firehouse #1, Firetruck Parking 

(2014-2015), Ornamental Firetruck Parking Location (2016), Former Live Fire FTA, and the 

grassy and paved areas surrounding the potential release areas. Based on PA findings, these are 

areas of known or suspected AFFF use and storage. 

Firetrucks containing AFFF and “protein foam”, as well as AFFF concentrate in 5-gallon buckets, 

were historically stored at the Former Firehouse #1. AFFF was dispensed from a Tri-MaxTM 30 fire 

extinguisher at the FTA at least once. AFFF sprayed in this area would have been released to the 

gravel ground surface in the 1990s, but the exact timeframe and the total volume, type, and 

concentration of AFFF released during training are unknown. AFFF, protein-based foam, or PFASladen water may have been released from the vehicles to the pavement and nearby grassy areas 

at the Firetruck Parking (2014-2015) and Ornamental Firetruck Parking Location (2016). 

Surface runoff across the areas are anticipated to generally flow north and west via sheet flow 

towards Grants Creek, via National Guard Road, and via the concrete drainage structure on the 

west side of the AOI. 

3.4 AOI 4 NC HART Training Area

AOI 4 consists of one potential PFAS release area: the North Carolina Helicopter Aquatic Rescue 

Team (NC HART) Training Area, an open field located off-facility and adjacent to the southwestern 

portion of the facility, where the 430th Engineer Firefighting Team performs fire training exercises. 

Although this training uses only water, the firetruck that is used also stores AFFF. It is possible 

that AFFF contained within the truck has migrated via backflow into other lines due to the corrosive 

nature of PFAS. As such, it is possible that the water within the firetruck used for training is 

contaminated with PFAS. 

Runoff from the training exercises likely flows into the small stream/drainage swale, bordering the 

FTA to the north, that drains west into Grants Creek. Therefore, there is a potentially complete 

exposure pathway for surface soil, subsurface soil, surface water and sediment, and groundwater 

to all receptors.
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12420 Milestone Center Drive

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AECOM 4-1

4. Project Data Quality Objectives

Project Data Quality Objectives (DQOs) are qualitative and quantitative statements that specify 

the quality of data and define the level of certainty required to support project decision-making

process. The specific DQOs established for this facility are described below. These DQOs were 

developed in accordance with the USEPA’s seven-step iterative process (USEPA, 2006). 

4.1 Problem Statement

The following problem statement was developed during project planning:

The presence of PFAS, which may pose a risk to human health or the environment, in 

environmental media at the facility is currently unknown. PFAS are classified as emerging 

environmental contaminants that are garnering increasing regulatory interest due to their potential 

risks to human health and the environment. The regulatory framework for managing PFAS at both 

the federal and state level continues to evolve. 

The DoD has adopted a policy to retain facilities in the CERCLA process based on risk-based 

SLs for soil and groundwater, as described in a memorandum from the Office of the Secretary of 

Defense (OSD) dated 15 September 2021 (Assistant Secretary of Defense, 2021). The ARNG 

program under which this SI was performed follows this DoD policy. Should the maximum site 

concentration for sampled media exceed the SLs established in the OSD memorandum, the AOI

will proceed to the next phase under CERCLA. The SLs established in the OSD memorandum 

apply to three compounds: PFOS, PFOA, and PFBS. The SLs are presented in Section 6.1 of 

this Report.

The following quotes from the DA policy documents form the basis for this project (DA, 2016; DA, 

2018): 

• “The Army will research and identify locations where PFOS- and/or PFOA-containing

products, such as AFFF, are known or suspected to have been used. Installations shall

coordinate with installation/facility fire response or training offices to identify AFFF use or

storage locations. The Army will consider FTAs, AFFF storage locations, hangars/buildings

with AFFF suppression systems, fire equipment maintenance areas, and areas where

emergency response operations required AFFF use as possible source areas. In addition,

metal plating operations, which used certain PFOS-containing mist suppressants, shall be

considered possible source areas.”.

• “Based on a review of site records...determine whether a CERCLA PA is appropriate for

identifying PFOS/PFOA release sites. If the PA determines a PFOS/PFOA release may

have occurred, a CERCLA SI shall be conducted to determine presence/absence of

contamination.”.

• “Identify sites where perfluorinated compounds are known or suspected to have been

released, with the priority being those sites within 20 miles of the public systems that tested

above USEPA HA levels.” (USEPA, 2016a; USEPA, 2016b).

4.2 Goals of the Study

The following goals were established for this SI:

1. Determine the presence or absence of PFOA, PFOS, and PFBS at or above SLs.

2. Develop information to potentially eliminate a release from further consideration because

it is determined that it poses no significant threat to human health or the environment.
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Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 4-2

3. Determine the potential need for a Time Critical Removal Action (TCRA) (applies to 

drinking water only). The primary actions that will be considered include provision of 

alternative water supplies or wellhead treatment.

4. Collect data to better characterize the release areas for more effective and rapid initiation 

of a RI (if determined necessary). 

5. If PFOA, PFOS, and PFBS are determined to be present, aim to evaluate whether the 

concentrations can be attributed to on-facility or off-facility sources that were identified 

within 4 miles of the installation as part of the PA (e.g., fire stations, major manufacturers, 

other DoD facilities).

6. Determine whether a potentially complete pathway exists between the source and 

potential receptors and whether ARNG is the likely source of the contamination. 

4.3 Information Inputs

Primary information inputs included:

• The PA for Salisbury AASF #2 (AECOM, 2020); 

• Analytical data from groundwater and soil samples collected as part of this SI in accordance 

with the site-specific Uniform Federal Policy-Quality Assurance Project Plan (QAPP) 

Addendum (AECOM, 2021a); and

• Field data collected during the SI, including groundwater elevation and water quality 

parameters measured at the time of sampling. 

4.4 Study Boundaries

The scope of the SI was bounded by the property limits of the facility (Figure 2-2). Off-facility sampling 

was included in the scope of this SI to address any potential releases by NCARNG during fire training 

activities completed at the NC HART Training Area. The required right of entry was obtained by ARNG

prior to the SI sampling event. 

4.5 Analytical Approach

Samples were analyzed by Pace Analytical Gulf Coast, accredited under the DoD Environmental 

Laboratory Accreditation Program (ELAP; Accreditation Number 74960) and the National 

Environmental Laboratory Accreditation Program (NELAP; Certificate Number 01955). Data were 

compared to applicable SLs and decision rules as defined in the SI QAPP Addendum (AECOM, 

2021a). These rules governed response actions based on the results of the SI sampling effort.

The decision rules described in the Worksheet #11 of the SI QAPP Addendum identify actions 

based on the following:

Groundwater:

• Is there a human receptor within 4 miles of the facility? 

• What is the concentration of PFOA, PFOS, and PFBS at the potential release areas? 

• What is the concentration of PFOA, PFOS, and PFBS at the facility boundary upgradient 

and downgradient of the potential release areas? 
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Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 4-3

• What does the conceptual site model (CSM) suggest in terms of source, pathway and 

receptor? 

Soil:

• What is the concentration of PFOA, PFOS, and PFBS in shallow surface soil (0 to 2 feet 

bgs)? 

• What is the concentration of PFOA, PFOS, and PFBS in deep soil (i.e., capillary fringe)?

• What does the CSM suggest in terms of source, pathway, and receptor? 

Soil and groundwater samples were collected from each of the AOIs. Groundwater was 

encountered between approximately 4.85 to 27.71 feet bgs. 

4.6 Data Usability Assessment

The Data Usability Assessment is an evaluation at the conclusion of data collection activities that 

uses the results of both data verification and validation in the context of the overall project 

decisions or objectives. Using both quantitative and qualitative methods, the assessment 

determines whether project execution and the resulting data have met installation-specific DQOs. 

Both sampling and analytical activities are considered to assess whether the collected data are 

of the right type, quality, and quantity to support the decision-making (DoD, 2019a; DoD, 2019b; 

USEPA, 2017b). 

Data Quality Indicators (DQIs) (Precision, Accuracy, Representativeness, Comparability, 

Completeness and Sensitivity) are important components in assessing data usability. These DQIs 

were evaluated in the subsequent sections and demonstrate that the data presented in this SI 

report are of high quality. Although the SI data are considered reliable, some degree of uncertainty 

can be associated with the data collected. Specific factors that may contribute to the uncertainty 

of the data evaluation are described below. The Data Validation Report (Appendix A) presents 

explanations for all qualified data in greater detail.

4.6.1 Precision

Precision is the degree of agreement among repeated measurements of the same characteristic 

on the same sample or on separate samples collected as close as possible in time and place. 

Field sampling precision is measured with the field duplicate relative percent differences (RPD); 

laboratory precision is measured with calibration verification, internal standard recoveries, 

laboratory control spike (LCS) and matrix spike (MS) duplicate RPD.

Injection internal standards (IIS) were added by the laboratory after sample extraction and prior 

to analysis as a legacy requirement of DoD Quality Systems Manual (QSM) 5.1 to measure 

relative responses of target analytes. Even though not required under the current DoD QSM 5.3 

analysis, the IIS are still added to the sample after extraction as an additional quality control (QC) 

measure. The IIS percent recoveries were within the established precision limits presented in the 

SI QAPP Addendum (AECOM, 2021a).

LCS/LCS duplicate (LCSD) pairs were prepared by addition of known concentrations of each 

analyte in a matrix-free media known to be free of target analytes. LCS/LCSD pairs were analyzed 

for every analytical batch to demonstrate the ability of the laboratory to detect similar 

concentrations of a known quantity in matrix-free media. The LCS/LCSDs performed during the 

laboratory analyses were within the project established precision limits presented in the SI QAPP 

Addendum (AECOM, 2021a), with one exception. One LCS/LCSD displayed a RPD greater than 

the QC limit of 30%, at 32% for perfluoroheptanoic acid (PFDoA). The positive associated field 

sample results were qualified as estimate and should be considered usable as qualified. 
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MS/MS duplicate (MSD) samples were prepared, analyzed, and reported for all preparation 

batches. MS/MSD samples demonstrated that the analytical system was in control for the matrix 

being tested. MS/MSD samples were submitted to the laboratory for analysis at a rate of 5%. The 

MS/MSD samples were within the project established precision limits presented in the SI QAPP 

Addendum (AECOM, 2021a)

Field duplicate samples were collected at a rate of 10% to assess the overall sampling and 

measurement precision for this sampling effort. The field duplicate samples were analyzed for 

PFAS and general chemistry parameters. The field duplicate samples were within the project 

established precision limits presented in the SI QAPP Addendum (AECOM, 2021a), with limited 

exceptions. Two field duplicate pairs displayed a positive result in one field sample and a nondetect result in the associated duplicate sample. The associated field sample results were 

qualified as estimate and should be considered usable as qualified. One field duplicate pair 

displayed RPD exceedances for PFBS and perfluorohexanesulfonic acid (PFHxS). The 

associated field sample results were qualified as estimate and should be considered usable as 

qualified. 

4.6.2 Accuracy

Accuracy is a measure of confidence in a measurement. The smaller the difference between the 

measurement of a parameter and its "true" or expected value, the more accurate the 

measurement. The more precise or reproducible the result, the more reliable or accurate the 

result. Accuracy is measured through percent recoveries in the LCS/LCSD, MS/MSD, and 

surrogates.

LCS/LCSD samples were prepared by addition of known concentrations of each analyte in a 

matrix free media known to be free of target analytes. LCS/LCSD samples were analyzed for 

every analytical batch and demonstrated that the analytical system was in control during sample 

preparation and analysis. The LCS/LCSDs performed during the laboratory analyses were within 

the project established accuracy limits presented in the SI QAPP Addendum (AECOM, 2021a) 

with limited exceptions. One LCS/LCSD displayed percent recoveries greater than the upper QC 

limits for perfluorodecanoic acid (PFDA), perfluorononanoic acid (PFNA), and 

perfluorotridecanoic acid (PFTrDA). The associated field sample results were non-detect and 

should be considered usable as reported. 

MS/MSD samples were prepared, analyzed, and reported at a rate of 5%. MS/MSD samples 

demonstrated that the analytical system was in control for the matrix being tested. The MS/MSDs 

performed during that laboratory analyses were within the project established accuracy limits 

presented in the SI QAPP Addendum (AECOM, 2021a) with limited exceptions. Three MS/MSD 

displayed percent recoveries outside the QC limits for PFHxS and/or PFOS. The positive parent 

sample results associated with high MS/MSD percent recoveries were qualified as estimate with 

a high bias. The field sample result associated with the low MS/MSD percent recovery was 

positive and was qualified as estimate with a low bias. The associated field sample results should 

be considered usable as qualified. 

Calibration verifications were performed routinely to ensure that instrument responses for all 

calibrated analytes were within established QC criteria. The calibration verifications performed 

during the laboratory analyses were within the project established accuracy limits presented in 

the SI QAPP Addendum (AECOM, 2021a). 

4.6.3 Representativeness

Representativeness qualitatively expresses the degree to which data accurately reflect site 

conditions. Factors that affect the representativeness of analytical data include appropriate 
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sample population definitions, proper sample collection and preservation techniques, analytical 

holding times, use of standard analytical methods, and determination of matrix or analyte 

interferences. 

Relating to the use of standard analytical methods, the laboratory followed the method as 

established in PFAS by liquid chromatography with tandem mass spectrometry (LC/MS/MS)

Compliant with QSM 5.1 Table B-15, including the specific preparation requirements (i.e. ENVICarb or equivalent used), mass calibration, spectra, all the ion transitions identified in Table B-15 

were monitored, standards that contained both branched and linear isomers when available were 

used, and isotopically labeled standards were used for quantitation.

Field QC samples were collected to assess the representativeness of the data collected. Field 

duplicates were collected at a rate of 10% for all field samples, while MS/MSD samples were 

collected at a rate of 5%. All preservation techniques were followed by the field staff. All technical 

and analytical holding times were met by the laboratory with the exception of field samples that 

required re-extraction after failing QC in the initial analysis in accordance with the DoD QSM. The 

laboratory used approved standard methods in accordance with the SI QAPP Addendum 

(AECOM, 2021a) for all analyses.

Instrument blanks and method blanks were prepared by the laboratory in each batch as a negative 

control. Six instrument blanks and fours method blank displayed concentrations for multiple 

analytes greater than the detection limit (DL). The positive field sample results associated with 

the blank detections that displayed concentrations less than five times the blank detections were 

qualified as likely false positives and should be treated as non-detect. The remaining field sample 

results associated with the blank detections were all greater than five times the blank 

concentration or were non-detect. The associated field sample results should be considered 

usable as reported. 

Field blanks and equipment blanks were also collected for groundwater and soil samples. Two 

field rinsate blanks and two equipment blanks displayed concentrations for multiple target 

analytes greater than the DL. The positive field sample results associated with the blank 

detections that displayed concentrations less than five times the blank detections were qualified 

as likely false positives and should be treated as non-detect. The remaining field sample results 

associated with the blank detections were all greater than five times the blank concentration or 

were non-detect. The associated field sample results should be considered usable as reported.

A sample of the water used for decontamination of the drill rig was collected in advance of the 

field effort. The decontamination sample (SA-DECON) displayed concentrations for several target 

analytes greater than the DL. The positive field sample results associated with the blank 

detections that displayed concentrations less than five times the blank detections were qualified 

as likely false positive and should be treated as non-detect. The remaining field sample results 

associated with the blank detections were all greater than five times the blank concentration or 

were non-detect. The associated field sample results should be considered usable as reported.

Field samples were extracted and analyzed within the appropriate holding time in order to 

qualitatively express the degree to which data accurately reflect site conditions, with limited 

exceptions. Three field samples were re-extracted and reanalyzed outside technical holding time 

due to QC failures. The associated field sample results were qualified as estimate and should be 

considered usable as qualified. The holding time for pH analysis is “immediate”, and all field 

samples analyzed for pH were qualified as estimate and should be considered usable as qualified.

Overall, the data are usable for evaluating the presence or absence of PFAS at the facility. 

Sufficient usable data were obtained to meet the objectives of the SI.
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4.6.4 Comparability

Comparability is the extent to which data from one study can be compared directly to either past 

data from the current project or data from another study. Using standardized sampling and 

analytical methods, units of reporting, and site selection procedures help ensure comparability. 

Standard field sampling and typical laboratory protocols were used during the SI and are 

considered comparable to ongoing investigations.

4.6.5 Completeness

Completeness is a measure of the amount of valid data obtained from a measurement system 

compared to the amount of data expected under normal conditions. The laboratory provided data 

meeting system QC acceptance criteria for all samples tested. Project completeness was 

determined by evaluating the planned versus actual quantities of data. Percent completeness per 

parameter is as follows and reflects the exclusion of “X” flagged data, if applicable:

• PFAS in aqueous media by LC/MS/MS compliant with QSM 5.3 Table B-15 at 100%

• PFAS in solid media by LC/MS/MS compliant with QSM 5.3 Table B-15 at 99.5%

• pH in soil by USEPA Method 9045D at 100%

• Total organic carbon (TOC) by USEPA Method 9060 at 100%

4.6.6 Sensitivity

Sensitivity is the capability of a test method or instrument to discriminate between measurement 

responses representing different levels (e.g., concentrations) of a variable of interest. Examples 

of QC measures for determining sensitivity include laboratory fortified blanks, an MDL study, and 

calibration standards at the limit of quantitation (LOQ). In order to meet the needs of the data 

users, project data must meet the measurement performance criteria for sensitivity and project 

LOQs specified in the SI QAPP Addendum (AECOM, 2021a). The laboratory provided the 

requested MDL studies and provided applicable calibration standards at the LOQ. In order to 

achieve the DQOs for sensitivity outlined in the SI QAPP Addendum (AECOM, 2021a), the 

laboratory reported all field sample results at the lowest possible dilution. Additionally, any 

analytes detected below the LOQ and above the DL were reported and qualified “J” as estimated 

values by the laboratory.
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5. Site Inspection Activities

This section describes the environmental investigation and sampling activities that occurred as 

part of the SI. The SI sampling approach was based on the findings of the PA and implemented 

in accordance with the following approved documents:

• Final Site Inspection Programmatic Uniform Federal Policy-Quality Assurance Project Plan 

dated March 2018 (AECOM, 2018a);

• Final Site Safety and Health Plan, Salisbury Army Aviation Support Facility #2, North 

Carolina dated May 2021 (AECOM, 2021b);

• Final Preliminary Assessment Report, Salisbury Army Aviation Support Facility #2, North 

Carolina dated August 2020 (AECOM, 2020);

• Final Site Inspection Uniform Federal Policy-Quality Assurance Project Plan Addendum, 

Salisbury Army Aviation Support Facility #2, North Carolina dated June 2021 (AECOM, 

2021a); and

• Final Programmatic Accident Prevention Plan dated July 2018 (AECOM, 2018b).

The SI field activities were conducted from 7 to 17 June 2021 and consisted of utility clearance,

sonicsoil boring, soil sample collection, temporary and permanent monitoring well installations, grab 

groundwater sample collection, and land surveying. Field activities were conducted in accordance 

with the SI QAPP Addendum (AECOM, 2021a), except as noted in Section 5.8.

The following samples were collected during the SI and analyzed for a subset of 18 PFAS by 

LC/MS/MS compliant with QSM 5.3 Table B-15 to fulfill the project DQOs:

• Forty-one (41) soil samples from 17 boring locations;

• Six grab groundwater samples from six permanent well locations; 

• Six grab groundwater samples from six temporary well locations;

• Eighteen (18) quality assurance (QA) samples.

Figure 5-1 provides the sample locations for all media across the facility. Table 5-1 presents the 

list of samples collected for each media. Field documentation is provided in Appendix B. A Log 

of Daily Notice of Field Activity was completed throughout the SI field activities, which is provided 

in Appendix B1. Sampling forms are provided in Appendix B2, monitoring well development 

forms are provided in Appendix B3, a Field Change Request Form is provided in Appendix B4, 

and survey data are provided in Appendix B5. Additionally, a photographic log of field activities 

is provided in Appendix C.

5.1 Pre-Investigation Activities

In preparation for the SI field activities, project team members participated in Technical Project 

Planning (TPP) meetings, performed utility clearance, and sampled decontamination source 

water. Details for each of these activities are presented below.

5.1.1 Technical Project Planning

The USACE TPP Process, Engineer Manual (EM) 200-1-2 (USACE, 2016) defines four phases 

to project planning: 1.) defining the project phase; 2.) determining data needs; 3.) developing data 

collection strategies; and 4.) finalizing the data collection plan. The process encourages 
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stakeholder involvement in the SI, beginning with defining overall project objectives, including 

quantitative and qualitative DQOs, and formulating a sampling approach to address the AOIs 

identified in the PA. 

A combined TPP Meeting 1 and 2 was held on 17 March 2021, prior to SI field activities. The 

combined TPP Meeting 1 and 2 was conducted in general accordance with EM 200-1-2. The 

stakeholders for this SI include the ARNG, NCARNG, USACE, North Carolina Department of 

Environmental Quality, and representatives familiar with the facility, the regulations, and the 

community. Stakeholders were provided the opportunity to make comments on the technical 

sampling approach and methods at the combined TPP Meeting 1 and 2. The outcome of the 

combined TPP Meeting 1 and 2 was memorialized in the SI QAPP Addendum (AECOM, 2021a).

A TPP Meeting 3 will be held after the field event to discuss the results of the SI. Meeting minutes 

for TPP 3 will be included in Appendix D of this report. Future TPP meetings will provide an 

opportunity to discuss the results and findings, and future actions, where warranted.

5.1.2 Utility Clearance

AECOM’s drilling subcontractor, Cascade Technical Services, LLC., placed a ticket with the North 

Carolina 811 utility clearance provider to notify them of intrusive work on 16 April 2021; however, 

because the AASF #2 is a private facility, the participating “Call Before You Dig” locators did not 

clear utilities at the entire facility. Therefore, AECOM contracted Taylor Wiseman & Taylor, LLC.,

a private utility location service, to perform utility clearance. Taylor Wiseman & Taylor, LLC.

performed utility clearance of the proposed boring locations on 1 June 2021, with input from the 

AECOM field team and Salisbury AASF #2 facility staff. General locating services and groundpenetrating radar were used to complete the clearance. Additionally, the first 5 feet of each boring 

were pre-cleared using a hand auger to verify utility clearance in shallow subsurface where utilities 

would typically be encountered.

5.1.3 Source Water and PFAS Sampling Equipment Acceptability

The potable water source used for decontamination of drilling equipment was confirmed to be 

acceptable for use in a PFAS investigation prior to the start of field activities. A sample from a 

potable water source at Salisbury AASF #2 was collected on 30 March 2021, prior to mobilization, 

and analyzed for PFAS by LC/MS/MS compliant with QSM 5.3 Table B-15. The results of the 

decontamination water sample are provided in Appendix F, and a discussion of the results is 

presented in Section 4.6.3.

Materials that were used within the sampling zone were confirmed as acceptable for use in the 

PFAS sampling environment. The checklist of acceptable materials for use in the PFAS sampling 

environment was provided in the Standard Operating Procedures (SOPs) appendix to the SI 

QAPP Addendum (AECOM, 2021a). Prior to the start of field work each day, a PFAS Sampling 

Checklist was completed as an additional layer of control. The checklist served as a daily reminder 

to each field team member regarding the allowable materials within the sampling environment.

5.2 Soil Borings and Soil Sampling

Soil samples were collected via a sonic drill rig, in accordance with the SI QAPP Addendum 

(AECOM, 2021a). A hand auger was used to collect soil from the top 5 feet of the boring, in 

accordance with AECOM utility clearance procedures. The soil boring locations are shown on 

Figure 5-1, and depths are provided Table 5-1.

In general, three discrete soil samples were collected from the vadose zone for chemical analysis 

from each soil boring: one surface soil sample (0 to 2 feet bgs), one subsurface soil sample 
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approximately 2 feet above the groundwater table, and one subsurface soil sample at the midpoint between the surface and the groundwater table. 

The soil cores were continuously logged for lithological descriptions by a field geologist using the 

Unified Soil Classification System (USCS). A photoionization detector (PID) was used to screen 

the breathing zone during boring activities as part of personal safety requirements. Observations 

and measurements were recorded on sampling forms (Appendix B2) and in a non-treated field 

logbook (i.e., composition notebook). Depth interval, recovery thickness, PID concentrations, 

moisture, relative density, color (using a Munsell soil color chart), and texture (using the USCS) 

were recorded. The boring logs are provided in Appendix E.

Soil borings completed during the SI found abundant lean clay, sandy lean clay, and clayey sand

as the dominant lithology of the unconsolidated sediments below the Salisbury AASF #2. Borings 

were completed at depths between 20 and 60 feet bgs. Isolated layers of sand and silty sand 

were observed, along with varying percentages of gravel in some logs. In some borings at AOIs 

3 and 4, saprolite and weathered bedrock were observed at varying depths. These observations 

are consistent with the understood geology of this region, including weathered metamorphic and 

igneous bedrock underlying fine-grained surficial sediments. Grain size samples were taken from 

surface soil at AOI02-01 and from the mid-point to the water table (15 to 20 feet bgs) at AOI03-

01. Results of this analysis (Appendix G) indicated high percentages of clay (27% to 33%) and 

silt (44% to 50%) along with sand, a majority of which was in the fine range (16% to 18%), and a 

small portion of medium-coarse sand (0.16% to 4.4%) and gravel (0.18% to 0.48%).

Each soil sample was collected into laboratory-supplied PFAS-free high-density polyethylene 

(HDPE) bottles and labeled using a PFAS-free marker or pen. Samples were packaged on ice 

and transported via Federal Express (FedEx) under standard chain of custody (CoC) procedures 

to the laboratory and analyzed for PFAS (LC/MS/MS compliant with QSM 5.3 Table B-15), TOC 

(USEPA Method 9060A) and pH (USEPA Method 9045D) in accordance with the SI QAPP 

Addendum (AECOM, 2021a).

Field duplicate samples were collected at a rate of 10% and analyzed for the same parameters 

as the accompanying samples. MS/MSDs were collected at a rate of 5% and analyzed for the 

same parameters as the accompanying samples. In instances when non-dedicated sampling

equipment was used, such as a hand auger for the shallow soil samples, equipment rinsate blanks 

were collected at a rate of 5% and analyzed for the same parameters as the soil samples. A 

temperature blank was placed in each cooler to ensure that samples were preserved at or below 

6 degrees Celsius (°C) during shipment.

Sonic borings were converted to permanent and temporary wells. Temporary wells were

subsequently abandoned in accordance with the SI QAPP Addendum (AECOM, 2021a) using 

bentonite chips after completion of sampling activities. Borings were installed in grass areas to 

avoid disturbing concrete or asphalt surfaces.

5.3 Temporary Well Installation and Groundwater Grab Sampling

Six temporary wells were installed using a sonic drill rig system. Once the borehole was advanced 

to the desired depth, wherever conditions allowed, a temporary well was constructed of a 5-foot

section of 1-inch Schedule 40 poly-vinyl chloride (PVC) screen with sufficient casing to reach 

ground surface. New PVC pipe and screen were used to avoid cross contamination between 

locations. The screen intervals for the temporary wells are provided in Table 5-2.

The temporary wells were allowed to recharge after installation before collection of groundwater 

samples. After the recharge period, groundwater samples were collected using a bladder pump 

with PFAS-free HDPE tubing. The temporary wells were purged at a rate determined in the field 

to reduce turbidity and draw down prior to sampling. Water quality parameters (e.g., temperature, 
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specific conductance, pH, dissolved oxygen [DO], and oxidation-reduction potential [ORP]) were 

measured using a water quality meter and recorded on the field sampling form (Appendix B2) 

after each grab sample was collected. Additionally, a subsample of each groundwater sample was 

collected in a separate container, and a shaker test was completed to identify if there were any 

foaming. Foaming was not noted on sampling forms or the CoC.

Each sample was collected into laboratory-supplied PFAS-free HDPE bottles and labeled using 

a PFAS-free marker or pen. Samples were packaged on ice and transported via FedEx under 

standard CoC procedures to the laboratory and analyzed for PFAS by LC/MS/MS compliant with 

QSM 5.3 Table B-15 in accordance with the SI QAPP Addendum (AECOM, 2021a).

Field duplicate samples were collected at a rate of 10% and analyzed for the same parameters 

as the accompanying samples. MS/MSDs were collected at a rate of 5% and analyzed for the 

same parameters as the accompanying samples. One field reagent blank was collected in 

accordance with the SI QAPP Addendum (AECOM, 2021a). A temperature blank was placed in 

each cooler to ensure that samples were preserved at or below 6°C during shipment.

Temporary wells were abandoned in accordance with the SI QAPP Addendum (AECOM, 2021a) 

by removing the PVC and backfilling the hole with bentonite chips. Temporary wells were installed 

in grass areas to avoid disturbing concrete or asphalt.

5.4 Permanent Well Installation and Groundwater Sampling

During the SI, five permanent monitoring wells were installed within or downgradient of potential 

source areas. The locations of the wells are shown on Figure 5-1. 

A sonic drill rig system was used to install five 2-inch diameter monitoring wells. Water was not 

added during the drilling of the wells with the exception of AOI04-03, where it was necessary to 

add approximately 100 gallons of water during rock coring. Drill water was removed during 

development. The monitoring wells were constructed with Schedule 40 PVC, flush threaded 5- or 

10-foot sections of riser, 0.010-inch slotted well screen, and a threaded bottom cap. A filter pack 

of 20/40 silica sand was installed in the annulus around the well screen to a minimum of 2-foot 

above the well screen. 

A 2-foot-thick bentonite seal was placed above the filter sand and hydrated with water. Bentonite 

grout was placed in the well annulus from the top of the bentonite seal to ground surface. The 

bentonite grout was allowed to set for 24 hours prior to well completion in accordance with the SI 

QAPP Addendum (AECOM, 2021a). All monitoring wells were completed with flush mount well 

vaults. The screen interval of each of the groundwater monitoring wells is provided in 

Table 5-3.

Development and sampling of wells was completed in accordance with the SI QAPP Addendum 

(AECOM, 2021a). The newly installed monitoring wells were developed no sooner than 24 hours 

following installation by a combination of surging with a surge block and over-pumping with a

submersible monsoon pump. Samples were collected no sooner than 24 hours following 

development via low-flow sampling methods using a QED Sample Pro® bladder pump with 

disposable PFAS-free, HDPE tubing. New tubing was used at each well and the pumps were 

decontaminated between each well. The wells were purged at a rate determined in the field to 

reduce draw down prior to sampling. Water quality parameters (e.g., temperature, specific 

conductance, pH, DO, and ORP) were measured using a water quality meter and recorded on 

the field sampling form (Appendix B2). Water levels were measured to the nearest 0.01 inch and 

recorded. Additionally, a subsample of each groundwater sample was collected in a separate 

container and a shaker test was completed to identify if there was any foaming. No foaming was 

noted in any of the groundwater samples.
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Each sample was collected into laboratory-supplied PFAS-free HDPE bottles and labeled using 

a PFAS-free marker or pen. Samples were packaged on ice and transported via FedEx under 

standard CoC procedures to the laboratory and analyzed for PFAS by LC/MS/MS compliant with 

QSM 5.3 Table B-15 in accordance with the SI QAPP Addendum (AECOM, 2021a).

Field duplicate samples were collected at a rate of 10% and analyzed for the same parameters 

as the accompanying samples. MS/MSDs were collected at a rate of 5% and analyzed for the 

same parameters as the accompanying samples. One FRB was collected in accordance with the 

PQAPP (AECOM, 2018a). A temperature blank was placed in each cooler to ensure that samples 

were preserved at or below 6°C during shipment.

5.5 Synoptic Water Level Measurements

A synoptic groundwater gauging event was performed on 17 June 2021 of the six new permanent 

monitoring wells. The synoptic gauging event did not include temporary monitoring wells, due to 

a North Carolina time restriction on temporary well abandonment. However, groundwater 

elevation measurements were taken from the six temporary monitoring wells on 9 June 2021 and 

11 June 2021. Water level measurements were taken from the northern side of the well casing. A 

groundwater flow contour map is provided in Figure 2-4. Groundwater elevation data for 

temporary and permanent monitoring wells are provided in Table 5-2 and 5-3, respectively.

5.6 Surveying

The northern side of each well casing was surveyed by North Carolina-licensed land surveyors 

following guidelines provided in the SOPs provided in the SI QAPP Addendum (AECOM, 2021a). 

Survey data from all temporary and permanent wells on the facility were collected on 15 June

2021 in the applicable Universal Transverse Mercator zone projection with World Geodetic 

System 84 datum (horizontal) and North American Vertical Datum 1988 (vertical). The surveyed 

well data are provided in Appendix B5.

5.7 Investigation-Derived Waste

As of the date of this report, the disposal of PFAS investigation-derived waste (IDW) is not 

regulated federally. PFAS IDW generated during the SI is considered non-hazardous waste and 

was managed in accordance with the SI QAPP Addendum (AECOM, 2021a) and with the DA

Guidance for Addressing Releases of PFAS, Q18 (DA, 2018).

Ten 55-gallon drums of soil IDW (i.e. soil cuttings) and sixteen 55-gallong drums of liquid IDW 

generated during the SI activities were placed in the drum staging area as indicated in the 

Photographic Log (Appendix C). The drums were labeled to indicate the type of media (i.e. soil 

or water) and the source location. The soil and liquid IDW were not sampled, and it is assumed 

that the PFAS characteristics of the associated samples collected from that source location.

Other solids such as spent PPE, plastic sheeting, tubing, rope, unused monitoring well 

construction materials, and other environmental media generated during the field activities were 

containerized and staged with the rest of the rest of the IDW.

5.8 Laboratory Analytical Methods

Samples were analyzed for a subset of 18 PFAS by LC/MS/MS compliant with QSM 5.3

Table B-15 at Pace Analytical Gulf Coast in Baton Rouge, Louisiana, a DoD ELAP and NELAP 

certified laboratory. The 18 PFAS analyzed as part of the ARNG SI program include the following:
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• 6:2 fluorotelomer sulfonic acid (6:2 FTS)

• 8:2 fluorotelomer sulfonic acid (8:2 FTS)

• N-ethyl perfluorooctanesulfonamidoacetic

acid (NEtFOSAA)

• N-methyl

perfluorooctanesulfonamidoacetic acid

(NMeFOSAA)

• Perfluorobutyrate (PFBA)

• Perfluorobutanesulfonic acid (PFBS)

• Perfluorodecanoic acid (PFDA)

• Perfluorododecanoic acid (PFDoA)

• Perfluoroheptanoic acid (PFHpA)

• Perfluorohexanoic acid (PFHxA)

• Perfluorohexanesulfonic acid (PFHxS)

• Perfluorononanoic acid (PFNA)

• Perfluorooctanoic acid (PFOA)

• Perfluorooctanesulfonic acid (PFOS)

• Perfluoropentanoic acid (PFPeA)

• Perfluorotetradecanoic acid (PFTeDA)

• Perfluorotridecanoic acid (PFTrDA)

• Perfluoroundecanoic acid (PFUdA)

Soil samples were also analyzed for TOC using USEPA Method 9060A and pH by USEPA Method 

9045D. 

5.9 Deviations from SI QAPP Addendum

Five deviations from the SI QAPP Addendum were identified during review of the field 

documentation. The deviations are noted below and documented in one Field Change Request 

Form (Appendix B4). 

• During the utility clearance prior to subsurface investigations, it was deemed appropriate to

move proposed well location AOI01-03 75 feet to the east to be closer to the potential

release area.

• Proposed well location AOI01-04 was moved approximately 65 feet to the west to avoid

utility conflicts.

• The proposed location for AOI02-01 was located adjacent to the gas and water utility lines

and was not installed. The boring location was removed from the SI Sampling scope

because it was co-located with an existing Rowan County monitoring well (AOI02-MW-1).

Rowan County provided permission to sample this well location for the SI, , and it was

determined appropriate to replace the original proposed well location AOI02-01 with a

groundwater sample collected from the existing well.

• The proposed location for AOI02-02 was located on a steep slope, close to trees, and on

top of the gas utility line. The purpose of the proposed location was to measure the potential

effects of drainage from AOI2, which would not be achieved by drilling at the next available

closest location due to the terrain. All of the surface water drainage at AOI2 is funneled to

the proposed location for AOI02-02; therefore, it was determined appropriate to replace the

subsurface boring with a surface soil sampling location. Note that because sample location

AOI2-01 was removed from the sampling scope, that AOI1-02 was renumbered as AOI2-

01.

• Proposed well location AOI03-02 was moved approximately 200 feet east, to the lowest

drainage point of AOI 3 and within the potential release area. Additionally, presence of

underground utilities did not allow for drilling at the original proposed location. This proposed

well location was also converted from a permanent to a temporary well, due to the new

location being in the middle of the potential release area, rather than downgradient of the

AOI as originally planned.
Table 5-1

Site Inspection Samples by Medium

Site Inspection Report, Salisbury AASF #2, North Carolina

Sample Identification

Sample

Collection 

Date/Time

Sample Depth 

(feet bgs)

PFAS by LC/MS/MS compliant with QSM 5.3 Table B-15TOC(USEPA Method 9060A)pH (USEPA Method 9045D)Grain Size (ASTM D-422)

Comments

AOI01-01-SB-0-2 6/10/2021 8:40 0 - 2 x

AOI01-01-SB-0-2-D 6/10/2021 8:40 0 - 2 x FD

AOI01-01-SB-8-10 6/10/2021 11:30 8 - 10 x x

AOI01-01-SB-8-10-MS 6/10/2021 11:30 8 - 10 x MS

AOI01-01-SB-8-10-MSD 6/10/2021 11:30 8 - 10 x MSD

AOI01-01-SB-18-20 6/10/2021 11:55 18 - 20 x

AOI01-02-SB-0-2 6/10/2021 14:00 0 - 2 x

AOI01-02-SB-11-13 6/10/2021 14:30 11 - 13 x

AOI01-02-SB-11-13-D 6/10/2021 14:30 11 - 13 x FD

AOI01-02-SB-23-25 6/10/2021 14:40 23 - 25 x

AOI01-03-SB-0-2 6/10/2021 15:25 0 - 2 x

AOI01-03-SB-09-11 6/10/2021 16:45 9 - 11 x x x

AOI01-03-SB-18-20 6/10/2021 17:15 18 - 20 x

AOI01-04-SB-0-2 6/11/2021 6:15 0 - 2 x

AOI01-04-SB-10-12 6/11/2021 9:30 10 - 12 x

AOI01-04-SB-20-22 6/11/2021 9:20 20 - 22 x

AOI02-01-SB-0-2 6/8/2021 11:45 0 - 2 x x x x

AOI03-01-SB-0-2 6/7/2021 10:00 0 - 2 x

AOI03-01-SB-13-15 6/7/2021 11:25 13 - 15 x

AOI03-01-SB-15-20 6/7/2021 11:30 15 - 20 x

AOI03-01-SB-25-30 6/7/2021 12:50 25-30 x

AOI03-02-SB-0-2 6/8/2021 8:30 0 - 2 x

AOI03-02-SB-5-10 6/8/2021 11:40 5 - 10 x x

AOI03-02-SB-7-10 6/8/2021 11:45 7 - 10 x

AOI03-02-SB-13-15 6/8/2021 12:00 13 - 15 x

AOI03-03-SB-0-2 6/8/2021 8:00 0 - 2 x

AOI03-03-SB-13-15 6/8/2021 9:15 13 - 15 x

AOI03-03-SB-15-20 6/8/2021 9:30 15 - 20 x

AOI03-04-SB-0-2 6/11/2021 11:25 0 - 2 x

AOI03-04-SB-13-15 6/11/2021 12:40 13 - 15 x

AOI03-04-SB-52-54 6/11/2021 15:20 52 - 54 x

AOI04-01-SB-0-2 6/10/2021 6:22 0 - 2 x

AOI04-01-SB-5-7 6/10/2021 7:30 5 - 7 x

AOI04-01-SB-5-7-D 6/10/2021 7:30 5 - 7 x FD

AOI04-01-SB-5-7-MS 6/10/2021 7:30 5 - 7 x MS

AOI04-01-SB-5-7-MSD 6/10/2021 7:30 5 - 7 x MSD

AOI04-01-SB-11-13 6/10/2021 7:40 11 - 13 x

AOI04-02-SB-0-2 6/9/2021 12:20 0 - 2 x

AOI04-02-SB-10-12 6/9/2021 14:35 10 - 12 x

AOI04-02-SB-10-12-D 6/9/2021 14:35 10 - 12 x FD

AOI04-02-SB-22-24 6/9/2021 14:38 22 - 24 x

AOI04-03-SB-0-2 6/8/2021 14:30 0 - 2 x x x

AOI04-03-SB-0-2-D 6/8/2021 14:30 0 - 2 x x FD

AOI04-03-SB-0-2-MS 6/8/2021 14:30 0 - 2 x x MS

AOI04-03-SB-0-2-MSD 6/8/2021 14:30 0 - 2 x x MSD

AOI04-03-SB-13-15 6/8/2021 16:30 13 - 15 x

AOI04-03-SB-28-30 6/9/2021 10:31 28 - 30 x

AOI04-04-SB-0-2 6/9/2021 11:50 0 - 2 x

AOI04-05-SB-0-2 6/9/2021 11:30 0 - 2 x

AOI04-05-SB-0-2-D 6/9/2021 11:30 0 - 2 x FD

AOI04-06-SB-0-2 6/9/2021 10:15 0 - 2 x

Soil Samples

AECOM 5-7
Table 5-1

Site Inspection Samples by Medium

Site Inspection Report, Salisbury AASF #2, North Carolina

Sample Identification

Sample

Collection 

Date/Time

Sample Depth 

(feet bgs)

PFAS by LC/MS/MS compliant with QSM 5.3 Table B-15TOC(USEPA Method 9060A)pH (USEPA Method 9045D)Grain Size (ASTM D-422)

Comments

AOI04-06-SB-0-2-MS 6/9/2021 10:15 0 - 2 x MS 

AOI04-06-SB-0-2-MSD 6/9/2021 10:15 0 - 2 x MSD

AOI04-07-SB-0-2 6/9/2021 9:20 0 - 2 x

AOI04-08-SB-0-2 6/9/2021 9:40 0 - 2 x

AOI01-01-GW 6/14/2021 10:40 NA x

AOI01-01-GW-D 6/14/2021 10:40 NA x FD

AOI01-02-GW 6/14/2021 14:20 NA x

AOI01-03-GW 6/17/2021 13:00 NA x

AOI01-04-GW 6/17/2021 14:05 NA x

AOI02-MW-1-060721 6/7/2021 13:15 NA x

AOI02-MW-1-060721-MS 6/7/2021 13:15 NA x MS

AOI02-MW-1-060721-MSD 6/7/2021 13:15 NA x MSD

AOI03-01-GW 6/8/2021 10:05 NA x

AOI03-02-GW 6/9/2021 14:10 NA x

AOI03-03-GW 6/9/2021 9:58 NA x

AOI03-04-GW 6/17/2021 10:20 NA x

AOI04-01-GW 6/10/2021 9:35 NA x

AOI04-01-GW-D 6/10/2021 9:35 NA x FD

AOI04-02-GW 6/10/2021 13:20 NA x

AOI04-03-GW 6/10/2021 10:45 NA x

SA-ERB-01 6/11/2021 8:55 NA x Sonic Core Barrel

SA-ERB-02 6/14/2021 8:00 NA x Sonic Core Barrel

SA-ERB-03 6/9/2021 13:07 NA x Hand Auger

SA-ERB-04 6/11/2021 8:00 NA x 1.75" Bladder Pump

SA-ERB-05 6/10/2021 11:00 NA x 0.85" Bladder Pump

SA-FRB-01 6/8/2021 15:45 NA x

Notes:

AASF = Army Aviation Support Facility

AOI = Area of Interest

ASTM = American Society for Testing and Materials

bgs = below ground surface

D = duplicate

ERB = equipment rinsate blank

FD = field duplicate

FRB = field reagent blank

GW = groundwater

LC/MS/MS = Liquid Chromatography Mass Spectrometry

MS/MSD = matrix spike/ matrix spike duplicate

NA = not applicable

PFAS = per- and polyfluoroalkyl substances

pH = potential for hydrogen

QSM = Quality Systems Manual

SB = soil boring

TOC = total organic carbon

USEPA = United States Environmental Protection Agency

Quality Control Samples

Groundwater Samples

AECOM 5-8
Table 5-2

Soil Boring Depths, Temporary Well Screen Intervals, and Groundwater Elevations

Site Inspection Report, Salisbury AASF #2, North Carolina

Area of 

Interest

Boring 

Location

Soil Boring 

Depth 

(feet bgs)

Temporary Well 

Screen Interval 

(feet bgs)

Top of Casing 

Elevation 

(feet NAVD88)

Ground Surface 

Elevation 

(feet NAVD88)

Depth to 

Water

(feet btoc)

Dept

Wa

(feet 

AOI03-01 40 30 - 40 750.48 746.28 25.14 20AOI03-02 20 10 - 20 735.39 731.59 8.65 4.8AOI03-03 30 20 - 30 746.34 740.94 19.47 14AOI04-01 20 15 - 20 732.91 731.57 13.00 11AOI04-02 30 20 - 30 727.13 727.13 19.82 19AOI04-03 40 30 - 40 742.1 740.47 29.34 27

Notes:Temporary well screen set above total depth to capture groundwater interface

AASF = Army Aviation Support FacilityAOI = Area of Interest

bgs = below ground surfacebtoc = below top of casingNAVD88 = North American Vertical Datum 1988

34

AECOM 5-6 

AECOM 
Table 5-3

Permanent Monitoring Well Screen Intervals and Groundwater Elevations

Site Inspection Report, Salisbury AASF #2, North Carolina

Area of 

Interest

Boring 

Location

Soil Boring 

Depth 

(feet bgs)

Permanent Well 

Screen Interval 

(feet bgs)

Top of Casing 

Elevation 

(feet NAVD88)

Ground Surface 

Elevation 

(feet NAVD88)

Depth to 

Water

(feet btoc)

Dep

Wa

(feet 

AOI01-01 25 15 - 25 752.78 753.08 12.55 12AOI01-02 30 20 - 30 741.84 742.20 15.80 16AOI01-03 30 20 - 30 744.88 745.16 17.72 18AOI01-04 30 20 - 30 747.54 747.76 24.97 25

2 AOI02-MW-1 38.22 Unknown 748.24 740.47 21.99 14

3 AOI03-04 50 50 - 60 726.83 727.11 12.79 13

Notes:Permanent well screen set above total depth to capture groundwater interface

AASF = Army Aviation Support FacilityAOI = Area of Interest

bgs = below ground surfacebtoc = below top of casingMW = monitoring wellNAVD88 = North American Vertical Datum 1988

1

AECOM 
!?

!?

!?

!?

A!

"S

!?

!?

!?

!?

!?

!?

!?

"S "S

"S

"S

"S

Drainage Swale

Drainage Swale

AOI 2

AOI 1

AOI 3

AOI 4 AOI01-01

AOI01-02

AOI01-03

AOI01-04

AOI02-MW-01

AOI02-01

AOI03-01 AOI03-02

AOI03-03

AOI03-04

AOI04-01

AOI04-02

AOI04-03

AOI04-08 AOI04-07

AOI04-05

AOI04-04

AOI04-06

0 200 400 800

Feet

Legend

!? Soil Boring/Permanent Monitoring Well

!? Soil Boring/Temporary Monitoring Well

"S Surface Soil Sample

A! Existing Rowan County Monitoring Well

Surface Water Flow Direction

Inferred Groundwater Flow Direction

Area of Interest

Facility Boundary

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

ST

1/7/2022

1/7/2022

Site Inspection for PFAS at Salisbury AASF #2, NC

1/7/2022

1:4,800 ­ Figure 5-1 PM CM 1/7/2022

12420 Milestone Center Drive

Germantown, MD 20876

Site Inspection Sample Locations

Base Map: Source: Esri, Maxar, GeoEye, Earthstar

Geographics, CNES/Airbus DS, USDA, USGS,

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\NC\Salisbury_AASF_Figures\SI_Figures\SI_Report\Fig_5-1_Salisbury_AASF_SI_Sample_Locations.mxd

Five soil samples will be collected from low-lying

areas within AOI 4. The depicted surface soil

samples are placeholders; specific locations will be

determined in the field.

AECOM 5-11
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 5-12

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 6-1

6. Site Inspection Results

This section presents the analytical results of the SI. The SLs used in this evaluation are 

presented in Section 6.1. A discussion of the results for each AOI is provided in Section 6.3

through Section 6.6. Table 6-2 through Table 6-5 present PFAS results for samples with 

detections in soil or groundwater; only constituents detected in one or more samples are included.

Tables that contain all results are provided in Appendix F, and the laboratory reports are provided 

in Appendix G. 

6.1 Screening Levels 

The DoD has adopted a policy to retain facilities in the CERCLA process based on risk-based 

SLs for soil and groundwater, as described in a memorandum from the OSD dated 15 September 

2021 (Assistant Secretary of Defense, 2021). The ARNG program under which this SI was 

performed follows this DoD policy. Should the maximum site concentration for sampled media 

exceed the SLs established in the OSD memorandum, the AOI will proceed to the next phase 

under CERCLA. The SLs established in the OSD memorandum apply to three compounds: 

PFOS, PFOA, and PFBS. 

Additionally, the USEPA issued drinking water lifetime Health Advisories (HAs) for PFOA and 

PFOS in May 2016 (USEPA 2016a; USEPA, 2016b). The USEPA HAs may also be used as SLs 

for groundwater samples collected at the facility boundary where off-facility drinking water wells 

are present downgradient. The SLs are presented on Table 6-1 below. All other results presented 

in this report are considered informational in nature and serve as an indication as to whether soil

and groundwater contain or do not contain PFAS within the boundaries of the facility. 

Table 6-1: Screening Levels (Soil and Groundwater)

Analyte

Residential

(Soil)

(μg/kg)a 

0-2 feet bgs

Industrial/ Commercial 

Composite Worker

(Soil)

(μg/kg)a 

2-15 feet bgs

Tap Water

(Groundwater) 

(ng/L)a

USEPA HA

(Groundwater 

representative of 

Drinking Water)

(ng/L)b,c

PFOA 130 1,600 40 70

PFOS 130 1,600 40 70

PFBS 1,900 25,000 600 -

Notes:

a.) Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS, PFOA, PFBS in Groundwater and Soil using 

USEPA’s Regional Screening Level Calculator. Hazard Quotient (HQ) = 0.1. 15 September 2021. 

b.) USEPA. 2016a. Drinking Water Health Advisory (HA) for PFOA. Office of Water (4304T). Health and Ecological Criteria Division, 

Washington, DC 20460. USEPA Document Number: 822-R-16-005. May 2016. / USEPA. 2016b. Drinking Water HA for PFOS. Office of 

Water (4304T). Health and Ecological Criteria Division, Washington, DC 20460. USEPA Document Number: 822-R-16-004. May 2016.

c.) USEPA HAs apply to the PFOA and PFOS concentrations individually or combined.

The data in the subsequent sections are compared against the SLs presented in Table 6-1. The 

SLs for groundwater are based on direct ingestion. The SLs for soil are based on incidental 

ingestion and are applied to the depth intervals reasonably anticipated to be encountered by the 

receptors identified at the facility: the residential scenario is applied to surface soil results (0 to 2

feet bgs), and the industrial/commercial worker scenario is applied to shallow subsurface soil 

results (2 to 15 feet bgs). The SLs are not applied to deep subsurface soil results (>15 feet bgs) 

because 15 feet is the anticipated limit of construction activities. 
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 6-2

6.2 Soil Physicochemical Analyses

To provide basic soil parameter information, soil samples were analyzed for TOC and pH, which 

are important for evaluating transport through the soil medium. Appendix F contains the results 

of the TOC and pH sampling. 

The data collected in this investigation will be used in subsequent investigations, where 

appropriate, to assess fate and transport of PFAS contaminants. According to the Interstate 

Technology Regulatory Council (ITRC), several important PFAS partitioning mechanisms include 

hydrophobic and lipophobic effects, electrostatic interactions, and interfacial behaviors. At 

relevant environmental pH values, certain PFAS are present as organic anions and are therefore 

relatively mobile in groundwater (Xiao et al., 2015), but tend to associate with the organic carbon 

fraction that may be present in soil or sediment (Higgins and Luthy 2006; Guelfo and Higgins, 

2013). When sufficient organic carbon is present, organic carbon normalized distribution 

coefficients (Koc values) can help in evaluating transport potential, though other geochemical 

factors (for example, pH and presence of polyvalent cations) may also affect PFAS sorption to 

solid phases (ITRC, 2018).

6.3 AOI 1 

This section presents the analytical results for soil and groundwater in comparison to SLs for AOI 

1, which includes four potential PFAS release areas: Current Aircraft Apron FTA, Historic Aircraft 

Apron Fuel Spills, Defueling Pad, and Current Firehouse. The detected compounds in soil and

groundwater are summarized on Table 6-2 through Table 6-5. The detections of PFOA, PFOS, 

and PFBS in soil and groundwater are presented on Figure 6-1 through Figure 6-4. 

6.3.1 AOI 1 Soil Analytical Results

PFOA, PFOS, and PFBS did not exceed the SLs in soil at AOI 1. Figure 6-1 through Figure 6-3

present the ranges of detections of PFOA, PFOS, and PFBS in soil. Table 6-2 through Table 6-4

summarize the detected compounds in soil. 

Soil was sampled from surface soil (0 to 2 feet bgs), shallow subsurface soil (8 to 13 feet bgs), 

and deep subsurface soil (18 and 25 feet bgs) at AOI01-01, AOI01-02, AOI01-03, and AOI01-04.

PFOA, PFOS, and PFBS were detected in soil, at concentrations several orders of magnitude 

lower than the SLs. In the surface soil, PFOA was detected at AOI01-02, AOI01-03, and AOI01-

04, with concentrations ranging from 0.138 J micrograms per kilogram (μg/kg) to 0.208 J μg/kg. 

PFOS was detected at locations AOI01-01 (Duplicate) and AOI01-04, at concentrations of 0.099 

J μg/kg and 11.6 μg/kg, respectively. PFBS was detected at AOI01-02 and AOI01-04, with 

concentrations of 1.12 J μg/kg and 0.979 J μg/kg, respectively. In the shallow subsurface soil,

there were no detections of PFOA at any of the four sampling locations. PFOS was detected at 

AOI01-03 and AOI01-04, with concentrations of 2.13 μg/kg and 0.120 J μg/kg, respectively. PFBS 

was detected at AOI01-04 with a concentration of 0.097 J μg/kg. In the deep subsurface soil, 

PFOA, PFOS, and PFBS were not detected at any of the four sampling locations. 

6.3.2 AOI 1 Groundwater Analytical Results

PFOS exceeded the SLs of in groundwater at AOI 1. PFOA and PFBS did not exceed the SLs at 

AOI 1. Figure 6-4 presents the ranges of detections of PFOA, PFOS, and PFBS in groundwater. 

Table 6-5 summarizes the detected compounds in groundwater. 

Groundwater was sampled at four permanent monitoring well locations (AOI01-01 through AOI01-

04). PFOA was detected below the OSD SL of 40 ng/L and the USEPA HA SL of 70 ng/L at all 

four locations, ranging from not detected (ND) to 25.2 ng/L. The OSD SL of 40 ng/L and the 
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 6-3

USEPA HA SL of 70 ng/L for PFOS were exceeded at AOI01-04, with a concentration of 139 ng/L, 

and it was detected below the SLs at the remaining well locations with concentrations ranging 

from ND to18.0 ng/L. PFBS was detected below the OSD SL of 600 ng/L at all four locations, with 

concentrations ranging from ND to 233 ng/L.

6.3.3 AOI 1 Conclusions

Based on the results of the SI, PFOA, PFOS, and PFBS were detected in soil and groundwater 

at AOI 1. The detected concentrations of PFOA, PFOS, and PFBS in soil were several orders of 

magnitude lower than the SLs. PFOS was detected in groundwater at a concentration above both

SLs at AOI01-04. PFOA and PFBS was detected in groundwater below the SLs at AOI 1. Based 

on the exceedance of the SL for PFOS in groundwater, further evaluation at AOI 1 is warranted. 

6.4 AOI 2

This section presents the analytical results for soil and groundwater in comparison to SLs for AOI 

2, which includes six potential PFAS release areas: Wash Rack, Former Firetruck Parking, Former 

Tri-MaxTM Demonstration Area, Historical Firetruck Washing Area, Former Firehouse #2, and 

Drainage Swale. The detected compounds in soil and groundwater are summarized on Table 6-

2 through Table 6-5. The detections of PFOA, PFOS, and PFBS in soil and groundwater are 

presented on Figure 6-1 through Figure 6-4. During utility clearance activities, the proposed 

location of AOI02-01 was not able to be drilled due to utility conflicts. A nearby existing permanent 

well, MW-1, was sampled in lieu of AOI02-01. Thus, only one surface soil sample was collected 

within AOI 2. This action was documented in a Field Change Request Form provided in Appendix 

B4.

6.4.1 AOI 2 Soil Analytical Results

PFOA, PFOS, and PFBS did not exceed the SLs in soil at AOI 2. Figure 6-1 through Figure 6-3

present the ranges of detections of PFOA, PFOS, and PFBS in soil. Table 6-2 through Table 6-4

summarize the detected compounds in soil.

At the Drainage Swale potential release area, soil was sampled from surface soil (0 to 2 feet bgs)

at AOI02-01. PFOA, PFOS, and PFBS were detected in surface soil, at concentrations below the 

SLs. PFOA was detected with a concentration of 0.280 J μg/kg, PFOS was detected at a 

concentration of 42.1 μg/kg, and PFBS was detected at a concentration of 0.136 J μg/kg.

6.4.2 AOI 2 Groundwater Analytical Results

PFOA and PFOS exceeded the SLs in groundwater at AOI 2. PFBS did not exceed the SL at this 

AOI. Figure 6-4 presents the range of detections for PFOA, PFOS, and PFBS in groundwater. 

Table 6-5 summarizes the detected compounds in groundwater.

Groundwater was sampled at AOI02-MW-1, located west of the Former Tri-MaxTM Demonstration 

FTA potential release area. PFOA and PFOS were detected above the OSD SLs of 40 ng/L and 

the individual and combined USEPA HA SLs of 70 ng/L at AOI02-MW-1, with concentrations of 

85.2 ng/L and 2,700 J ng/L, respectively. PFBS was detected below the OSD SL of 600 ng/L, at 

a concentration of 200 ng/L.

6.4.3 AOI 2 Conclusions

Based on the results of the SI, PFOA, PFOS, and PFBS were detected in soil and groundwater 

at AOI 2. The detected concentrations of PFOA, PFOS, and PFBS in soil were below the SLs. 

PFOA and PFOS were detected in groundwater at concentrations above the SLs. PFBS was 
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 6-4

detected in groundwater, at concentrations below the SL. Based on the exceedances of the SLs 

for PFOA and PFOS in groundwater, further evaluation at AOI 2 is warranted. 

6.5 AOI 3 

This section presents the analytical results for soil and groundwater in comparison to SLs for AOI 

3, which includes four potential PFAS release areas: Former Live Fire FTA, Firetruck Parking 

(2014-2015), Former Firehouse #1, and Ornamental Firetruck Parking Location (2016). The 

detected compounds in soil and groundwater are presented in Table 6-2 through Table 6-5. The 

detections of PFOA, PFOS, and PFBS in soil and groundwater are presented on Figure 6-1

through Figure 6-4. 

6.5.1 AOI 3 Soil Analytical Results

PFOA, PFOS, and PFBS in soil did not exceed the SLs in soil at the four potential PFAS release 

areas in AOI 3. Figure 6-1 through Figure 6-3 present the ranges of detections of PFOA, PFOS, 

and PFBS in soil. Table 6-2 through Table 6-4 summarize the detected compounds in soil. 

Soil was sampled from surface soil (0 to 2 feet bgs), shallow subsurface soil (7 to 15 feet bgs), 

and deep subsurface soil (15 and 54 feet bgs). Soil was sampled from three intervals at boring 

locations AOI03-01, AOI03-03, and AOI03-04; and from two intervals at boring location AOI03-02. 

PFOA, PFOS, and PFBS were detected at concentrations several orders of magnitude lower than 

the SLs. PFOA was detected in surface soil (0 to 2 feet bgs) at all four locations, with 

concentrations ranging from 0.188 J μg/kg to 2.92 μg/kg. PFOS was also detected in surface soil 

at all four locations, with concentrations ranging from 0.453 J μg/kg to 17.3 μg/kg. PFBS was 

detected at AOI03-01, with a concentration of 0.024 J μg/kg. In shallow subsurface soil, PFOA 

and PFOS were detected at AOI03-01, AOI03-02, and AOI03-03. PFOA was detected at AOI03-

03, with a concentration of 0.476 J μg/kg. PFOS was detected at AOI03-01 and AOI03-02, with 

concentrations of 0.166 J μg/kg and 0.697 J μg/kg, respectively. PFBS was not detected in 

subsurface soil at any of the four locations sampled at AOI 3. In deep subsurface soil, PFOA 

detected at AOI03-03 with a concentration of 0.513 J μg/kg. PFBS and PFOS were not detected 

in deep subsurface soil. 

6.5.2 AOI 3 Groundwater Analytical Results

PFOA and PFOS exceeded the SLs in groundwater at AOI 3. PFBS did not exceed the SL at this 

AOI. Figure 6-4 presents the ranges of detections for PFOA, PFOS, and PFBS in groundwater. 

Table 6-5 summarizes the detected compounds in groundwater. 

Groundwater was sampled from three temporary monitoring well locations (AOI03-01 through

AOI03-03) and one permanent monitoring well location (AOI03-04). PFOA was detected above 

the OSD SL of 40ng/L and the USEPA HA SL of 70 ng/L at AOI03-03, with a concentration of 93.5 

ng/L. PFOA was detected below the OSD SL of 40 ng/L and the USEPA HA SL of 70 ng/L at

AOI03-01, AOI03-02 and AOI03-04, with concentrations ranging from ND to 26.2 ng/L. PFOS was 

detected above the OSD SL at AOI03-02, with a concentration of 50.5 ng/L. PFOS was detected 

below the SLs at AOI03-01, AOI03-02, and AOI03-04, with concentrations ranging from 1.38 J 

ng/L to 6.90 ng/L. PFBS was detected in all four well locations below the OSD SL of 600 ng/L, 

with concentrations ranging from 1.22 J ng/L to 2.97 J ng/L.

6.5.3 AOI 3 Conclusions

Based on the results of the SI, PFOA, PFOS, and PFBS were detected in soil and groundwater 

at AOI 3. The detected concentrations of PFOA, PFOS, and PFBS in soil were orders of 

magnitude lower than the SLs. PFOA was detected in groundwater at concentrations exceeding 
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 6-5

the SLs at AOI3-03. PFOS was detected in groundwater at concentrations exceeding the OSD 

SL at AOI03-02. PFBS was detected in groundwater at concentrations below the SL. Based on 

the exceedances of the SLs for PFOA and PFOS in groundwater, further evaluation at AOI 3 is 

warranted. 

6.6 AOI 4

This section presents the analytical results for soil and groundwater in comparison to SLs for AOI 

4, which includes one potential PFAS release area: NC HART Training Area. The detected 

compounds in soil and groundwater are summarized on Table 6-2 through Table 6-5. The 

detections of PFOA, PFOS, and PFBS in soil and groundwater are presented on Figure 6-1

through Figure 6-4.

6.6.1 AOI 4 Soil Analytical Results

Soil was sampled from surface soil (0 to 2 feet bgs), shallow subsurface soil (5 to 15 feet bgs), 

and deep subsurface soil (22 and 30 feet bgs) at boring locations AOI04-01 AOI04-03, and AOI04-

03. Soil was sampled from surface soil (0 to 2 feet) at boring locations AOI04-04, AOI04-05, 

AOI04-06, AOI04-07, and AOI04-08. The detected concentrations of PFOA, PFOS, and PFBS in 

soil were several orders of magnitude lower than the SLs. Figure 6-1 through Figure 6-3 present 

the ranges of detections of PFOA, PFOS, and PFBS in soil. Table 6-2 through Table 6-4

summarize the detected compounds in soil.

PFOA and PFBS were not detected in the eight surface soil sample locations. PFOS was detected 

in five of the eight sample locations, with concentrations ranging from ND to 0.890 J- μg/kg. In 

shallow subsurface soil, PFOA and PFOS were not detected in soil at any boring location. PFBS 

was detected at AOI04-01, with a concentration of 0.045 J μg/kg, which is several orders of 

magnitudes below the SL of 25,000 μg/kg. In deep subsurface soil, PFOA and PFOS were not 

detected in soil at any boring location. PFBS was detected at AOI04-02, with a concentration of 

0.253 J μg/kg.

6.6.2 AOI 4 Groundwater Analytical Results

PFOA, PFOS and PFBS did not exceed the SLs in groundwater at AOI 4. Figure 6-4 presents 

the ranges of detections for PFOA, PFOS, and PFBS in groundwater. Table 6-5 summarizes the 

detected compounds in groundwater. 

Groundwater was sampled from three temporary monitoring well locations (AOI04-01, AOI04-02, 

and AOI04-03). PFOA was detected below the SL of 40 ng/L and the USEPA HA SL of 70 ng/L at 

all well locations, with concentrations ranging from 2.25 J ng/L to 7.04 ng/L. PFOS was detected

below the SL of 40 ng/L and the USEPA HA SL of 70 ng/L at all well locations, with concentrations 

ranging from 2.59 J ng/L to 15.9 ng/L. PFBS was also detected below the OSD SL of 600 ng/L at 

all well locations, with concentrations ranging from 1.25 J ng/L to 308 ng/L. 

6.6.3 AOI 4 Conclusions

Based on the results of the SI, PFOA, PFOS, and PFBS were detected in soil and groundwater 

at AOI 4. The detected concentrations of PFOA, PFOS, and PFBS in soil were several orders of 

magnitude lower than the SLs. PFOA, PFOS, and PFBS were detected in groundwater at 

concentrations below the SLs at all well locations. Based on these observations, no further 

evaluation is warranted at AOI 4. If screening levels are revised in the future, further evaluation of 

AOI 4 may be required.
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 6-6

THIS PAGE INTENTIONALLY BLANK
Table 6-2

PFAS Detections in Surface Soil

Site Inspection Report, Salisbury AASF Facility #2

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual 

8:2 FTS - ND ND ND ND ND ND 

NEtFOSAA - ND ND ND ND ND 0.043 J 

PFBA - ND ND ND ND 0.058 J 0.390 J 

PFBS 1900 ND ND 1.12 J ND 0.979 J 0.136 J 

PFDA - ND ND ND ND ND 0.136 J 

PFDoA - ND ND ND ND 0.034 J 0.084 J 

PFHpA - ND ND ND ND 0.113 J 0.126 J 

PFHxA - ND ND ND ND 0.544 J 0.416 J 

PFHxS - ND ND ND 0.695 J 8.41 1.78 

PFNA - ND ND 0.063 J 0.042 J ND 0.177 J PFOA 130 ND ND 0.159 J 0.138 J 0.208 J 0.280 J 

PFOS 130 ND UJ 0.099 J ND ND 11.6 42.1 

PFPeA - ND ND ND ND 0.085 J 0.549 J 

PFTeDA - ND ND ND ND ND 0.053 J 

PFTrDA - ND ND ND ND ND 0.057 J 

PFUnDA - ND ND ND 0.025 J ND 0.121 J 

Grey Fill Detected concentration exceeded OSD Screening Levels 

References Interpreted Qualifiers J = Estimated concentration UJ = The analyte was not detected at a level greater than or equal to the adjusted detection limit (DL). However, the reported adjusted DL is approximate and may be inaccurate or imprecise. 

Acronyms and Abbreviations 

AASF Army Aviation Support Facility 

AOI Area of Interest 

D duplicate ft feet 

HQ hazard quotient ID identification LCMSMS liquid chromatography with tandem mass spectrometry 

LOD limit of detection

ND analyte not detected above the LODOSD Office of the Secretary of Defense

QSM Quality Systems ManualQual interpreted qualifierSB soil boringUSEPA United States Environmental Protection Agencyμg/kg micrograms per kilogram- not applicable

Area of Interest

Sample ID

Sample Date

Depth

AOI01-01-SB-0-2

06/10/2021

0 - 2 ft

AOI01-01-SB-0-2-D

06/10/2021

0 - 2 ft

AOI01-02-SB-0-2

06/10/2021

0 - 2 ft

0 - 2 ft 

AOI01-04-SB-0-2

06/11/2021

AOI01-03-SB-0-2

06/10/2021

0 - 2 ft

06/08/2021

0 - 2 ft

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS, PFOA, and PFBS in Groundwater or Soil using USEPA’s RegionalScreening Level Calculator. HQ=0.1. 15 September 2021. Soil screening levels based on residential scenario for direct ingestion of contaminated soil.

AOI02

AOI02-01-SB-0-2 

AOI01 

Soil, PFAS by LCMSMS compliant with QSM 5.3 Table B-15 (μg/kg)

AECOM 
Table 6-2

PFAS Detections in Surface Soil

Site Inspection Report, Salisbury AASF Facility #2

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual Result Qual Result Qual Result Qu

8:2 FTS - ND ND ND ND ND ND 

NEtFOSAA - ND ND ND ND ND ND 

PFBA - ND ND ND ND ND ND 

PFBS 1900 ND ND ND ND ND ND 

PFDA - ND ND ND ND ND ND 

PFDoA - ND ND ND ND ND ND 

PFHpA - ND ND ND ND ND ND 

PFHxA - 0.030 J ND 0.041 J ND 0.026 J ND UJ PFHxS - ND 0.097 J ND ND ND ND 

PFNA - ND ND ND ND ND ND 

PFOA 130 ND ND ND ND ND ND 

PFOS 130 ND 0.100 J 0.099 J ND 0.471 J 0.141 J 

PFPeA - ND ND 0.026 J ND ND ND 

PFTeDA - ND ND ND ND 0.144 J ND UJ 

PFTrDA - ND ND ND ND 0.109 J ND UJ 

PFUnDA - ND ND ND ND ND ND 

Grey Fill Detected concentration exceeded OSD Screening Levels 

References Interpreted Qualifiers 

J = Estimated concentration 

J- = Estimated concentration, biased low 

UJ = The analyte was not detected at a level greater than or equal to the adjusted detection limit (DL). However, the reported adjusted DL is approximate and may be inaccurate or imprecise. 

Acronyms and Abbreviations 

AASF Army Aviation Support Facility 

AOI Area of Interest 

D duplicate 

ft feet 

HQ hazard quotient 

ID identification 

LCMSMS liquid chromatography with tandem mass spectrometry 

LOD limit of detectionND analyte not detected above the LODOSD Office of the Secretary of DefenseQSM Quality Systems ManualQual interpreted qualifierSB soil boringUSEPA United States Environmental Protection Agencyμg/kg micrograms per kilogram- not applicable

06/09/2021

0 - 2 ft

Soil, PFAS by LCMSMS compliant with QSM 5.3 Table B-15 (μg/kg)

Area of Interest

Sample ID

Sample Date

Depth

AOI04-01-SB-0-2

06/10/2021

0 - 2 ft

AOI04-02-SB-0-2

06/09/2021

0 - 2 ft

AOI04-03-SB-0-2

06/08/2021

0 - 2 ft

AOI04-04-SB-0-2

06/09/2021

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS, PFOA, and PFBS in Groundwater or Soil using USEPA’s RegionalScreening Level Calculator. HQ=0.1. 15 September 2021. Soil screening levels based on residential scenario for direct ingestion of contaminated soil.

AOI04

AOI04-05-SB-0-

06/09/2021

0 - 2 ft

0 - 2 ft 

AOI04-05-SB-0-2

AECOM 
Table 6-3

PFAS Detections in Shallow Subsurface Soil

Site Inspection Report, Salisbury AASF Facility #2

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual 

Soil, PFAS by LCMSMS compliant with QSM 5.3 Table B-15 (μg/kg)PFBA - ND ND ND ND ND ND 

PFBS 25000 ND ND ND ND 0.097 J ND 

PFHpA - ND ND ND ND ND 0.029 J 

PFHxA - ND ND ND ND 0.071 J 0.075 J 

PFHxS - ND ND ND 0.110 J 0.331 J 0.583 J 

PFOA 1600 ND ND ND ND ND ND 

PFOS 1600 ND ND ND 2.13 0.120 J 0.697 J 

PFPeA - ND ND ND ND ND 0.058 J 

Grey Fill Detected concentration exceeded OSD Screening Levels 

References Interpreted Qualifiers

J = Estimated concentration 

06/07/2021

13 - 15 ft

AOI01 

AOI01-04-SB-10-12

06/11/2021

10 - 12 ft

AOI01-02-SB-11-13-D 

06/10/2021

11 - 13 ft

AOI01-02-SB-11-13

06/10/2021

11 - 13 ft

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS, PFOA, and PFBS in Groundwater or Soil using USEPA’s RegionalScreening Level Calculator. HQ=0.1. 15 September 2021. Soil screening levels based on residential scenario for direct ingestion of contaminated soil.

Area of Interest

Sample ID

Sample Date

Depth

AOI01-01-SB-8-10

06/10/2021

8 - 10 ft

AOI01-03-SB-09-11

06/10/2021

9 - 11 ft

AOI03-01-SB-13-1

AECOM 
Table 6-3

PFAS Detections in Shallow Subsurface Soil

Site Inspection Report, Salisbury AASF Facility #2

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual Result Qual Result Qual Result Qu

Soil, PFAS by LCMSMS compliant with QSM 5.3 Table B-15 (μg/kg)PFBA - ND ND ND ND ND ND

PFBS 25000 ND ND 0.045 J ND ND ND

PFHpA - ND ND ND ND ND ND

PFHxA - ND ND 0.037 J ND ND ND

PFHxS - ND ND 0.405 J ND ND ND

PFOA 1600 ND ND ND ND ND ND

PFOS 1600 ND ND ND ND ND ND

PFPeA - ND ND ND ND ND ND

Grey Fill Detected concentration exceeded OSD Screening Levels 

References 

Interpreted Qualifiers

J = Estimated concentration 

06/08/2021

13 - 15 ft

AOI04-02-SB-10-12

06/09/2021

10 - 12 ft

AOI04-02-SB-10-12-D

06/09/2021

10 - 12 ft

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS, PFOA, and PFBS in Groundwater or Soil using USEPA’s RegionalScreening Level Calculator. HQ=0.1. 15 September 2021. Soil screening levels based on residential scenario for direct ingestion of contaminated soil.

AOI04

AOI04-01-SB-11-13

06/10/2021

11 - 13 ft

06/10/2021

5 - 7 ft

AOI04-01-SB-5-7

06/10/2021

5 - 7 ft

AOI04-01-SB-5-7-D

Area of Interest

Sample ID

Sample Date

Depth

AOI04-03-SB-13

AECOM 
Table 6-4

PFAS Detections in Deep Subsurface Soil

Site Inspection Report, Salisbury AASF Facility #2

Area of Interest

Sample ID

Sample Date

Depth

Analyte Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result 

6:2 FTS ND ND ND ND ND 1.20 J ND PFBA ND ND ND ND ND 0.195 J ND 

PFBS ND ND ND ND ND ND ND 

PFDoA ND ND 0.044 J ND ND ND ND 

PFHpA ND ND ND ND ND 0.789 J ND 

PFHxA ND ND ND ND ND 0.408 J 0.035 

PFNA ND ND ND ND ND 0.067 J ND 

PFOA ND ND ND ND ND 0.513 J ND 

PFPeA ND ND ND ND ND 0.571 J 0.060 

PFTeDA ND ND ND UJ ND ND ND ND 

Interpreted Qualifiers J = Estimated concentration 

Soil, PFAS by LCMSMS compliant with QSM 5.3 Table B-15 (μg/kg)

AOI01 AOI03 

AOI03-04

06/1

52 

AOI03-01-SB-25-30

06/07/2021

25 - 30 ft

AOI03-03-SB-15-20

06/08/2021

15 - 20 ft

AOI01-03-SB-18-20

06/10/2021

18 - 20 ft

AOI01-04-SB-20-22

06/11/2021

20 - 22 ft

AOI01-01-SB-18-20

06/10/2021

18 - 20 ft

AOI01-02-SB-23-25

06/10/2021

23 - 25 ft

AECOM 
Table 6-5

PFAS Detections in Groundwater

Site Inspection Report, Salisbury AASF Facility #2

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual Result Qual Result Qual Result Qu

6:2 FTS - ND ND ND ND ND 24.6 

8:2 FTS - ND ND ND ND ND 7.18 

PFBA - ND ND ND 1.68 J 26.3 36.3 

PFBS 600 ND ND 17.4 3.43 J 233 200 PFHpA - ND ND ND ND 22.2 33.6 

PFHxA - ND ND ND 4.87 145 178 

PFHxS - ND ND 31.7 25.6 709 627 J+ 

PFNA - ND ND ND ND ND ND 

PFOA 40 ND ND ND 1.38 J 25.2 85.2 

PFOS 40 ND ND ND 18.0 139 2700 J 

PFPeA - ND ND ND 2.65 J 41.6 70.8 

Grey Fill Detected concentration exceeded OSD Screening Levels Chem

6:2 FT8:2 FTPFAS 

References PFBA 

PFBS PFHpA PFHxA 

Interpreted Qualifiers PFHxS J = Estimated concentration PFNA J+ = Estimated concentration, biased high PFOA 

UJ = The analyte was not detected at a level greater than or equal to the adjusted detection limit (DL). However, the reported adjusted DL is approximate and may be inaccurate or imprecise. PFOS 

PFPeA Acrony

AASF AOI D GW HQ ID LCMSLOD ND OSD QSM Qual RE USEPng/l - 

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS, PFOA, and PFBS in Groundwater or Soil using USEPA’s RegionalScreening Level Calculator. HQ=0.1. 15 September 2021. Groundwater screening levels based on residential scenario for direct ingestion of groundwater.

Water, PFAS by LCMSMS compliant with QSM 5.3 Table B-15 (ng/l)

AOI01 

AOI02

AOI02-MW-1-06

06/07/2021

AOI01-03-GW

06/17/2021

AOI01-04-GW

06/17/2021

AOI01-01-GW-D

06/14/2021

AOI01-02-GW

06/14/2021

Area of Interest

Sample ID

Sample Date

AOI01-01-GW

06/14/2021

AECOM 
Table 6-5

PFAS Detections in Groundwater

Site Inspection Report, Salisbury AASF Facility #2

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual Result Qual Result Qual

6:2 FTS - 16.6 ND UJ ND UJ ND ND

8:2 FTS - ND ND UJ ND UJ ND NDPFBA - 130 2.16 J 1.81 J 11.2 1.56 J

PFBS 600 1.82 J 10.9 J 9.78 J 308 1.25 JPFHpA - 101 2.28 J 1.96 J 8.73 ND

PFHxA - 313 9.16 J 8.16 J 76.1 2.16 JPFHxS - 3.77 J 30.8 J 26.1 J 597 1.59 JPFNA - 1.84 J ND UJ ND UJ ND NDPFOA 40 26.2 2.71 J 2.47 J 7.04 2.25 J

PFOS 40 3.53 J 4.29 J 3.67 J 15.9 2.59 JPFPeA - 573 4.55 J 4.30 J 11.5 1.76 J

Grey Fill Detected concentration exceeded OSD Screening Levels Chem

6:2 FT8:2 FTPFAS 

References PFBA 

PFBS PFHpA PFHxA 

Interpreted Qualifiers PFHxS J = Estimated concentration PFNA J+ = Estimated concentration, biased high PFOA 

UJ = The analyte was not detected at a level greater than or equal to the adjusted detection limit (DL). However, the reported adjusted DL is approximate and may be inaccurate or imprecise. PFOS 

PFPeA Acrony

AASF AOI D GW HQ ID LCMSLOD ND OSD QSM Qual RE USEPng/l - 

06/11/2021

Area of Interest

Sample ID

Sample Date

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS, PFOA, and PFBS in Groundwater or Soil using USEPA’s RegionalScreening Level Calculator. HQ=0.1. 15 September 2021. Groundwater screening levels based on residential scenario for direct ingestion of groundwater.

AOI03

AOI03-04-GW

06/17/2021

Water, PFAS by LCMSMS compliant with QSM 5.3 Table B-15 (ng/l)

AOI04

AOI04-02-GW

06/10/2021

AOI04-03-GW

06/10/2021

AOI04-01-GW (RE)

06/11/2021

AOI04-01-GW-D (RE)

AECOM 
AECOM 

Site Inspection ReportSalisbury Army Aviation Suppot Facility #2, North Carolina

THIS PAGE INTENTIONALLY BLANK
Drainage Swale

Drainage Swale AOI01-01

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI03-01 AOI03-02

AOI03-03

AOI03-04

AOI04-01

AOI04-02

AOI04-03

AOI04-08 AOI04-07

AOI04-05

AOI04-04

AOI04-06

Drainage Swale

Drainage Swale AOI01-01

AOI01-02

AOI01-03

AOI01-04

AOI03-01

AOI03-02

AOI03-03

AOI03-04

AOI04-01

AOI04-02

AOI04-03

Drainage Swale

Drainage Swale AOI01-01

AOI01-02

AOI01-03

AOI01-04

AOI03-01

AOI03-02

AOI03-03

AOI03-04

AOI04-01

AOI04-02

AOI04-03

CLIENT

REVISED

SCALE

PROJECT

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Site Inspection for PFAS at Salisbury AASF #2, NC

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11/9/2021

11/9/2021

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Base Map: Source: Esri, Maxar, GeoEye, Earthstar Geographics, CNES/Airbus DS,

USDA, USGS, AeroGRID, IGN, and the GIS User Community

Figure 6-1

PFOA Detections in Soil

12420 Milestone Center Drive ­ Germantown, MD 20876

Legend

Facility Boundary

1:6,000

0 250 500 1,000

Feet

PFOA Results (μg/Kg)

ND

>ND - 10

>10 - 130

>130 - 1,600

>1,600

Shallow Intermediate Deep

AECOM 6-15
Drainage Swale

Drainage Swale AOI01-01

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI03-01 AOI03-02

AOI03-03

AOI03-04

AOI04-01

AOI04-02

AOI04-03

AOI04-08 AOI04-07

AOI04-05

AOI04-04

AOI04-06

Drainage Swale

Drainage Swale AOI01-01

AOI01-02

AOI01-03

AOI01-04

AOI03-01

AOI03-02

AOI03-03

AOI03-04

AOI04-01

AOI04-02

AOI04-03

Drainage Swale

Drainage Swale AOI01-01

AOI01-02

AOI01-03

AOI01-04

AOI03-01

AOI03-02

AOI03-03

AOI03-04

AOI04-01

AOI04-02

AOI04-03

CLIENT

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SCALE

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Site Inspection for PFAS at Salisbury AASF #2, NC

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Base Map: Source: Esri, Maxar, GeoEye, Earthstar Geographics, CNES/Airbus DS,

USDA, USGS, AeroGRID, IGN, and the GIS User Community

Figure 6-2

PFOS Detections in Soil

12420 Milestone Center Drive ­ Germantown, MD 20876

Legend

Facility Boundary

1:6,000

0 250 500 1,000

Feet

PFOS Results (μg/Kg)

ND

>ND - 10

>10 - 130

>130 - 1,600

>1,600

Shallow Intermediate Deep

AECOM 6-16
Drainage Swale

Drainage Swale AOI01-01

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI03-01 AOI03-02

AOI03-03

AOI03-04

AOI04-01

AOI04-02

AOI04-03

AOI04-08 AOI04-07

AOI04-05

AOI04-04

AOI04-06

Drainage Swale

Drainage Swale AOI01-01

AOI01-02

AOI01-03

AOI01-04

AOI03-01

AOI03-02

AOI03-03

AOI03-04

AOI04-01

AOI04-02

AOI04-03

Drainage Swale

Drainage Swale AOI01-01

AOI01-02

AOI01-03

AOI01-04

AOI03-01

AOI03-02

AOI03-03

AOI03-04

AOI04-01

AOI04-02

AOI04-03

CLIENT

REVISED

SCALE

PROJECT

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Site Inspection for PFAS at Salisbury AASF #2, NC

11/9/2021

11/9/2021

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Base Map: Source: Esri, Maxar, GeoEye, Earthstar Geographics, CNES/Airbus DS,

USDA, USGS, AeroGRID, IGN, and the GIS User Community

Figure 6-3

PFBS Detections in Soil

12420 Milestone Center Drive ­ Germantown, MD 20876

Legend

Facility Boundary

1:6,000

0 250 500 1,000

Feet

PFBS Results (μg/Kg)

ND

>ND - 10

>10 - 130

>130 - 1,600

>1,600

Shallow Intermediate Deep

AECOM 6-17
Drainage Swale

Drainage Swale AOI01-01

AOI01-02

AOI01-03

AOI01-04

AOI02-MW-01

AOI03-01 AOI03-02

AOI03-03

AOI03-04

AOI04-01

AOI04-02

AOI04-03

Drainage Swale

Drainage Swale AOI01-01

AOI01-02

AOI01-03

AOI01-04

AOI02-MW-01

AOI03-01 AOI03-02

AOI03-03

AOI03-04

AOI04-01

AOI04-02

AOI04-03

Drainage Swale

Drainage Swale AOI01-01

AOI01-02

AOI01-03

AOI01-04

AOI02-MW-01

AOI03-01

AOI03-02

AOI03-03

AOI03-04

AOI04-01

AOI04-02

AOI04-03

CLIENT

REVISED

SCALE

PROJECT

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Site Inspection for PFAS at Salisbury AASF #2, NC

11/9/2021

11/9/2021

11/9/2021

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Base Map: Source: Esri, Maxar, GeoEye, Earthstar Geographics, CNES/Airbus DS,

USDA, USGS, AeroGRID, IGN, and the GIS User Community

Figure 6-4

PFOA, PFOS, and PFBS Detections 

in Groundwater

12420 Milestone Center Drive ­ Germantown, MD 20876

Legend

Facility Boundary

Groundwater Flow Direction 1:6,000

0 250 500 1,000

Feet

PFOA PFOS PFBS

PFOA Results (ng/L)

ND

>ND - 10

>10 - 40

>40 - 70

>70 - 400

>400

PFOS Results (ng/L)

ND

>ND - 10

>10 - 40

>40 - 70

>70 - 400

>400

PFBS (ng/L)

ND

>ND - 100

>100 - 600

>600 - 1,000

>1,000 - 6,000

>6,000

AECOM 6-18
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 7-1

7. Exposure Pathways

The CSMs for each AOI, revised based on the SI findings, are presented on Figure 7-1 and

Figure 7-2. A CSM presents the current understanding of the site conditions with respect to known 

and suspected on-facility sources, potential transport mechanisms and migration pathways, and 

potentially exposed human receptors. A human exposure pathway is considered potentially 

complete when the following conditions are present:

1. Contaminant source;

2. Environmental fate and transport;

3. Exposure point;

4. Exposure route; and

5. Potentially exposed populations.

If any of these elements are missing, the pathway is incomplete. The CSM figures use an empty 

circle symbol to represent an incomplete exposure pathway. Areas with an incomplete pathway 

generally warrant no further action. However, the pathway is considered potentially complete if 

PFOA, PFOS, or PFBS are detected, in which case the CSM figure uses a half-filled circle symbol 

to represent a potentially complete exposure pathway. Additionally, a completely filled circle symbol 

is used to indicate when a potentially complete exposure pathway has detections of PFOA, PFOS, 

or PFBS above the SLs. Areas with an identified potentially complete pathway that have detections 

of PFOA, PFOS, or PFBS above the SLs may warrant further investigation.

In general, the potential routes of exposure to PFAS are ingestion and inhalation. Human

exposure via the dermal contact pathway may occur, and current risk practice suggests it is an 

insignificant pathway compared to ingestion; however, exposure data for dermal pathways are 

sparse and continue to be the subject of PFAS toxicological study. The receptors evaluated are 

consistent with those listed in USEPA guidance for risk screening (USEPA, 2001). Receptors at 

the facility include site workers (e.g., facility staff and visiting soldiers), construction workers,

residents outside the facility boundary, and recreational users outside of the facility boundary.

7.1 Soil Exposure Pathway

The SI results for PFOA, PFOS, and PFBS in soil were used to determine whether a potentially 

complete pathway exists between the source and potential receptors at AOI 1 through 4 based 

on the aforementioned criteria.

7.1.1 AOI 1

AOI 1 encompasses the Current Aircraft Apron FTA, Aircraft Apron Fuel Spills, Defueling Pad, 

Current Firehouse, and the grassy areas surrounding the potential release areas. AFFF was 

released in three of the potential release areas to combat potential fires, and AFFF is also stored 

on the aircraft apron and at the Current Firehouse. It is also possible that AFFF were released 

during training activities at the Current Aircraft Apron FTA. PFOA, PFOS, and PFBS were detected 

in soil below the SLs and confirm the release of PFAS to soil at AOI 1. Based on the results of the 

SI in AOI 1, ground-disturbing activities could potentially result in site worker or future construction 

worker exposure to PFOA, PFOS, and PFBS via inhalation of dust or incidental ingestion of 

surface soil. Ground-disturbing activities could potentially result in future construction worker 

exposure to PFOS and PFBS via incidental ingestion of subsurface soil. AOI 1 was being 

resurfaced during the SI activities; however, no current construction is occurring at AOI 1. The 

CSM for AOI 1 is presented on Figure 7-1. 
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 7-2

7.1.2 AOI 2 

AOI 2 encompasses the Former Firehouse #2, Historical Firetruck Washing Area, Former TriMaxTM Demonstration FTA, Wash Rack, Former Firetruck Parking Area, Drainage Swale, and 

grassy areas surrounding the potential release areas. During the 1990s, AFFF was released to 

asphalt pavement between the Current and Former Firehouses during firefighting demonstrations 

conducted at the former FTA. PFOA, PFOS, and PFBS were detected in soil below the SLs and 

confirm the release of PFAS to soil at AOI 2. Based on the results of the SI in AOI 2, grounddisturbing activities could potentially result in site worker and future construction worker exposure 

to PFOA, PFOS and PFBS via inhalation of dust or incidental ingestion of surface soil. Grounddisturbing activities could potentially result in future construction worker exposure to PFOA, 

PFOS, and PFBS via incidental ingestion of subsurface soil. No current construction is occurring 

at AOI 2. The CSM for AOI 2 is presented on Figure 7-1. 

7.1.3 AOI 3 

AOI 3 encompasses the Former Firehouse #1, Firetruck Parking (2014-2015), Ornamental 

Firetruck Parking Location (2016), Former Live Fire FTA, and the grassy and paved areas 

surrounding the potential release areas. In the 1990s, AFFF was dispensed at the FTA at least 

once, likely to the gravel ground surface, and AFFF could have been released at other potential 

release areas where AFFF was stored. PFOA, PFOS, and PFBS were detected in soil below the 

SLs and confirm the release of PFAS to soil at AOI 3. Based on the results of the SI in AOI 3, 

ground-disturbing activities could potentially result in site worker and future construction worker 

exposure to PFOA, PFOS, and PFBS via inhalation of dust or incidental ingestion of surface soil. 

Ground-disturbing activities could also potentially result in future construction worker exposure to 

PFOA and PFOS via incidental ingestion of subsurface soil. No current construction is occurring 

at AOI 3. The CSM for AOI 3 is presented on Figure 7-1. 

7.1.4 AOI 4 

There were no known releases of AFFF at AOI 4, which encompasses the NC HART Training 

Area to the southwest of the facility boundary. This area is adjacent to the facility where the 430th

Engineer Firefighting Team conducts fire training exercises. Although this training uses only water, 

the firetruck used also stores AFFF. PFOA was not detected in soil at AOI 4. PFOS and PFBS 

were detected in soil below the SLs and confirm the release of PFAS at AOI 4. Based on the 

results of the SI at AOI 4, ground-disturbing activities could potentially result in site worker and 

future construction worker exposure to PFOS and PFBS via inhalation of dust or incidental 

ingestion of surface soil. Ground-disturbing activities could also potentially result in future 

construction worker exposure to PFBS via incidental ingestion of subsurface soil. No current 

construction is occurring at AOI 4. The CSM for AOI 4 is presented on Figure 7-2. 

7.2 Groundwater Exposure Pathway

The SI results for PFOA, PFOS, and PFBS in groundwater were used to determine whether a 

potentially complete pathway exists between the source and potential receptors at each AOI 

based on the aforementioned criteria. Salisbury AASF receives its potable water from SalisburyRowan Utilities, which sources from the confluence of the South Yadkin River and the Yadkin 

River, approximately 8 miles northeast of the facility. Therefore, the ingestion exposure pathway 

for site workers is considered incomplete. 
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 7-3

7.2.1 AOI 1

PFOS exceeded the SL in one monitoring well location in AOI 1 (AOI01-04). PFOA, PFOS, and 

PFBS were detected at the remaining monitoring wells below the SLs (AOI01-02 and AOI01-03). 

Based on the results of the SI and groundwater flow direction the ingestion exposure pathway is 

considered potentially complete for off-facility residents. Due to the presence of shallow 

groundwater (less than 15 feet bgs), future construction workers may be exposed to contaminated 

groundwater under trenching scenarios. The CSM for AOI 1 is presented on Figure 7-1. 

7.2.2 AOI 2 

PFOA and PFOS exceeded the SLs at the one monitoring well location in AOI 2 (AOI02-MW-1), 

which is located west and downgradient of the Former Tri-MaxTM Demonstration FTA potential 

release area. PFBS was detected below the SL. Based on the results of the SI and groundwater 

flow direction the ingestion exposure pathway is considered potentially complete for off-facility 

residents. Due to the presence of shallow groundwater (less than 15 feet bgs), future construction 

workers may be exposed to contaminated groundwater under trenching scenarios. The CSM for 

AOI 2 is presented on Figure 7-1. 

7.2.3 AOI 3 

PFOA exceeded the SL in one temporary monitoring well location (AOI01-03). PFOS exceeded 

the SL in one temporary well location (AOI3-02). PFOA, PFOS, and PFBS were detected at 

additional monitoring wells below the SLs (AOI01-02 and AOI01-03). Based on the results of the 

SI and groundwater flow direction the ingestion exposure pathway is considered potentially 

complete for off-facility residents. Due to the presence of shallow groundwater (less than 15 feet 

bgs), future construction workers may be exposed to contaminated groundwater under trenching 

scenarios. The CSM for AOI 3 is presented on Figure 7-1. 

7.2.4 AOI 4 

PFOA, PFOS, and PFBS were all detected below the SLs at AOI 4, which is associated with the 

NC HART Training Area. Based on the results of the SI and groundwater flow direction the 

ingestion exposure pathway is considered potentially complete for off-facility residents. Due to the 

presence of shallow groundwater (less than 15 feet bgs), future construction workers may be 

exposed to contaminated groundwater under trenching scenarios. The CSM for AOI 4 is 

presented on Figure 7-2. 

7.3 Surface Water Sediment Exposure Pathway

The SI results for PFOA, PFOS, and PFBS in soil and groundwater, in combination with 

knowledge of the fate and transport properties of PFAS, were used to determine whether a 

potentially complete pathway exists between the source and potential receptors.

PFAS are water soluble and can migrate readily from soil to surface water via leaching and runoff. Because PFOA, PFOS, and PFBS were detected in soil and groundwater at the AOIs, it is 

possible that those compounds may have migrated from soil and groundwater to Grants Creek 

and tributaries to Grant Creek west of the facility via groundwater discharge or drainage swales.

Therefore, the surface water and sediment ingestion exposure pathway for the off-facility 

recreational user is considered potentially complete. Grants Creek is a tributary of the Yadkin 

River (US Fish and Wildlife Service [USFWS], 2020). The CSM for AOI 1, AOI 2, AOI 3, and AOI 

4 are presented on Figure 7-1 and Figure 7-2. 
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Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 7-4 

THIS PAGE INTENTIONALLY BLANK 
Media

SOURCE PATHWAY RE

AOI 1AOI 2AOI 3

Fire training activities / 

AFFF storage / Vehicle 

washing and parking /

AFFF use during 

response to fuel spills

PFAS in 

Surface 

Soil / 

Paved 

Surfaces

Human 

Activities

Precipitation/ 

Run-Off

Leaching/ Infiltration

Airborne Soil 

Particulate

Surface Soil 

at AOI

Surface 

Water/ 

Sediment

Subsurface 

Soil

Shallow 

Groundwater

Source Release Mechanism Media Transport and Migration Media Exposure Routes

Inhalation of 

Dust

IngestionIngestion

Ingestion

Ingestion

Hum

C

Flow-Chart ContinuesPartial / Possible FlowIncomplete PathwayPotentially Complete PathwayComplete Pathway

Site 

Worker2

Cons

Wo

Site 

Worker2

Cons

Wo

/ / 

LEGEND

/ 

/ 

/ 

Fig

Conceptual Site Mod

Salisbu

Potential 

Off-Facility 

Source Not 

under 

Control of 

ARNG

Notes:

1. The resident and recreational userreceptors refer to an off-site resident andrecreational user.2. The site worker and construction workerreceptors refer only to Salisbury AASF #2 site and construction workers.3. No current active construction at the facility.

Flow-Chart Stops

7-4 
Media

SOURCE PATHWAY RE

AOI 4 Fire training activities / AFFF storage

PFAS in 

Surface 

Soil / 

Paved 

Surfaces

Human 

Activities

Precipitation/ 

Run-Off

Leaching/ Infiltration

Airborne Soil 

Particulate

Surface Soil 

at AOI

Surface 

Water/ 

Sediment

Subsurface 

Soil

Shallow 

Groundwater

Source Release Mechanism Media Transport and Migration Media Exposure Routes

Inhalation of 

Dust

IngestionIngestion

Ingestion

Ingestion

Hum

C

Flow-Chart ContinuesPartial / Possible FlowIncomplete PathwayPotentially Complete PathwayComplete Pathway

Site 

Worker2

Cons

Wo

Site 

Worker2

Cons

Wo

/ / 

LEGEND

/ 

/ 

/ 

Fig

Conceptual 

Salisbu

Potential 

Off-Facility 

Source Not 

under 

Control of 

ARNG

Notes:

1. The resident and recreational userreceptors refer to an off-site resident andrecreational user.2. The site worker and construction workerreceptors refer only to Salisbury AASF #2 site and construction workers.3. No current active construction at the facility.

Flow-Chart Stops
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 8-1

8. Summary and Outcome

This section summarizes SI activities and findings. The most significant findings are summarized 

in this section and are reproduced directly or abstracted from information contained in this report. 

The outcome provides general and comparative interpretations of the findings relative to the SLs.

8.1 SI Activities

The SI field activities were conducted from 7 to 17 June 2021 and consisted of utility clearance, 

sonic drilling, soil sample collection, temporary and permanent monitoring well installation, grab 

groundwater sample collection, and land surveying. Field activities were conducted in accordance 

with the SI QAPP Addendum (AECOM, 2021a), except as previously noted in Section 5.8.

To fulfill the project DQOs set forth in the approved SI QAPP Addendum (AECOM, 2021a), 

samples were collected and analyzed for a subset of PFAS by LC/MS/MS compliant with QSM

5.3 Table B-15 as follows. The 18 PFAS analyzed as part of the ARNG SI program are specified 

in Section 5.7 of this Report.

• Forty-one (41) soil samples from 17 boring locations; 

• Six grab groundwater samples from six permanent well locations; 

• Six grab groundwater samples from six temporary well locations; and

• Eighteen (18) QA samples.

The information gathered during this investigation was used to determine if PFOA, PFOS, and/or

PFBS were present at or above SLs. Additionally, the CSMs were refined to assess whether a 

potentially complete pathway exists between the source and potential receptors for potential 

exposure to PFOA, PFOS, and PFBS at the AOIs, which are described in Section 7.

8.2 SI Goals Evaluation

As described in Section 4.2, the SI activities were designed to achieve six main goals or DQOs. 

This section describes the SI goals and the conclusions that can be made for each based on the 

data collected during this investigation. 

1. Determine the presence or absence of PFOA, PFOS, and PFBS at or above SLs.

PFOA, PFOS, and PFBS were detected at the facility in soil and groundwater. PFOA in 

groundwater at AOI 2 and AOI 3 exceeded the SL of 40 ng/L. PFOS in groundwater at AOI 

1, AOI 2, and AOI 3 exceeded the SL of 40 ng/L. PFBS was detected in groundwater below 

the SL of 600 ng/L at all AOIs. The detected concentrations of PFOA, PFOS, and PFBS 

in soil samples from all AOIs were below the SLs.

2. Develop information to potentially eliminate a release from further consideration because 

it is determined that it poses no significant threat to human health or the environment.

One potential PFAS release area was removed from further consideration based on the 

soil and groundwater data collected during this SI: NC HART Training Area. PFOA, PFOS, 

and PFBS were not detected in groundwater and/ or soil above the SLs in this area; 

therefore, AOI 4 poses no significant threat to human health or the environment.
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 8-2

3. Determine the potential need for a TCRA (applies to drinking water only). The primary 

actions that will be considered include provision of alternative water supplies or wellhead 

treatment.

Based on the data collected during the SI, there is a potentially complete pathway between 

the potential PFAS release areas and downgradient public supply wells. 

4. Collect data to better characterize the release areas for more effective and rapid initiation 

of a RI (if determined necessary).

The geological data collected as part of the SI indicate moderately- to low-permeability

environment, with soils dominated by lean clay, sandy lean clay, and clayey sand. These 

observations are consistent with the understood geology of this region, including 

weathered metamorphic and igneous bedrock underlying fine-grained surficial sediments.

Depth to water at the facility ranges from 4.85 to 27.71 feet bgs. Groundwater flow 

direction at the facility is towards the north and northwest. These geologic and 

hydrogeologic observations inform development of technical approach for the RI.

5. If PFOA, PFOS, and PFBS are determined to be present, aim to evaluate whether the 

concentrations can be attributed to on-facility or off-facility sources that were identified 

within 4 miles of the installation as part of the PA (e.g., fire stations, major manufacturers, 

other DoD facilities)

Based upon the evaluation of soil and groundwater results in comparison to SLs, in 

combination with the groundwater flow direction analysis, the results of the SI indicate that 

the source of detected concentrations of PFOA, PFOS, and PFBS at the facility is likely 

attributable to ARNG activities.

6. Determine whether a potentially complete pathway exists between the source and 

potential receptors and whether ARNG is the likely source of the contamination. 

Detections of PFOA, PFOS, and PFBS in soil and groundwater at source areas and the 

facility boundary indicate there are a potentially complete pathways between source and 

off-facility receptors.

8.3 Outcome 

Based on the CSMs developed and revised in light of the SI findings, there is potential for 

exposure to off-facility residents from AOI 1 through 3 from sources on facility resulting from 

historical DoD activities. Sample analytical concentrations collected during the SI were compared 

against the project SLs for PFOA, PFOS, and PFBS in soil and groundwater, as described in 

Table 6-1. A summary of the results of the SI data relative to the SLs is as follows:

• At AOI 1, PFOS in groundwater at the potential release areas exceeded the SL of 40 ng/L,

with a maximum concentration of 139 ng/L at location AOI01-04. PFOS in groundwater 

downgradient of AOI 1 also exceeded the USEPA HA SL of 70 ng/L. Based on the results

of the SI, further evaluation of AOI 1 is warranted in the RI.

• At AOI 2, PFOA and PFOS in groundwater at the potential release areas exceeded the SLs 

of 40 ng/L with maximum concentrations of 85.2 ng/L and 2,700 ng/L, respectively, at 

location AOI02-MW-1(existing Rowan County Monitoring Well). PFOA and PFOS in 

groundwater downgradient of AOI 2 also exceeded the individual and combined USEPA HA 

SL of 70 ng/L. Based on the results of the SI, further evaluation of AOI 2 is warranted in the 

RI.
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Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 8-3

• At AOI 3, PFOA in groundwater at the potential PFAS release areas exceeded the SL of 40 

ng/L, with a concentration of 93.5 ng/L at location AOI03-03. Additionally, PFOS in 

groundwater at the potential PFAS release areas exceeded the SL of 40 ng/L, with a 

concentration of 50.5 ng/L at location AOI03-02. PFOA in groundwater at the Ornamental 

Firetruck Parking Location also exceeded the USEPA HA SL of 70 ng/L. Based on the 

results of the SI, further evaluation of AOI 3 is warranted in the RI. 

• At AOI 4, detected concentrations of PFOA, PFOS, and PFBS in groundwater were below 

SLs. Based on the results of the SI, no further evaluation of AOI 4 is warranted. If screening 

levels are revised in the future, further evaluation of AOI 4 may be required.

• The detected concentrations of PFOA, PFOS, and PFBS in soil at all AOIs were below the 

SLs. 

Table 8-1 summarizes the SI results for soil and groundwater. Based on the CSMs developed 

and revised in light of the SI findings, there is potential for exposure to off-facility receptors caused

by DoD activities at or adjacent to the facility.

Table 8-2 summarizes the rationale used to determine if an AOI should be considered for further 

investigation under CERCLA and undergo an RI. Based on the results of this SI, further evaluation 

is warranted in the RI for AOI 1: Southern Portion of the facility, AOI 2: Central Portion of the 

facility, and AOI 3: Northern Portion of the facility.
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Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 8-4

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Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 8-5

Table 8-1: Summary of Site Inspection Findings

AOI Potential PFAS 

Release Area

Soil – 

Source Area

Groundwater – 

Source Area

Groundwater –

Facility 

Boundary

1 

Southern Portion of 

Salisbury AASF #2 

(Current Aircraft Apron 

FTA, Aircraft Apron Fuel 

Spills, Defueling Pad, and 

Current Firehouse)

2 

Central Portion of 

Salisbury AASF #2 

(Former Firehouse #2, 

Historical Firetruck 

Washing Area, Former 

Tri-Max Demonstration 

FTA, Wash Rack, Former 

Firetruck Parking Area, 

Drainage Swale)

3

Northern Portion of 

Salisbury AASF #2 

(Former Firehouse #1, 

Firetruck Parking, 

Ornamental Firetruck 

Parking Location, Former 

Live Fire FTA

4 NC HART Training Area

Legend:

N/A = Not applicable 

NC HART = North Carolina Helicopter Aquatic Rescue Team

= detected; exceedance of the screening levels

= detected; no exceedance of the screening levels

= not detected
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 8-6

Table 8-2: Site Inspection Recommendations

AOI Description Rationale Future Action

1 

Southern Portion of 

Salisbury AASF #2 

(Current Aircraft 

Apron FTA, Aircraft 

Apron Fuel Spills, 

Defueling Pad, and 

Current Firehouse)

Exceedances of SLs in groundwater at 

potential release areas. No exceedances of 

SLs in soil. 

Proceed to RI 

2 

Central Portion of 

Salisbury AASF #2 

(Former Firehouse 

#2, Historical 

Firetruck Washing 

Area, Former TriMax Demonstration 

FTA, Wash Rack, 

Former Firetruck 

Parking Area, 

Drainage Swale)

Exceedances of SLs in groundwater at 

potential release areas. No exceedances of 

SLs in soil.

Proceed to RI 

3 

Northern Portion of 

Salisbury AASF #2 

(Former Firehouse 

#1, Firetruck 

Parking, Ornamental 

Firetruck Parking 

Location, Former 

Live Fire FTA

Exceedances of SLs in groundwater at 

potential release areas. No exceedances of 

SLs in soil.

Proceed to RI 

4 NC HART Training 

Area

Detections in groundwater but no 

exceedances of SLs. No exceedances of 

SLs in soil. 

No further action* 

Notes: 

* If screening levels are revised in the future, further evaluation of AOI 4 may be required.

NC HART = North Carolina Helicopter Aquatic Rescue Team
Site Inspection Report

Salisbury Army Aviation Suppot Facility #2, North Carolina

AECOM 9-1

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