FINAL 

Site Inspection Report 

Winder Barrow AASF 

Winder, Georgia

Perfluorooctanesulfonic Acid (PFOS) and

Perfluorooctanoic Acid (PFOA) Impacted Sites

ARNG Installations, Nationwide 

June 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 ...............................................................................................2-1

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

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

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

2.2.6 Sensitive Habitat and Threatened/ Endangered Species.............................2-3

2.3 History of PFAS Use ...............................................................................................2-3

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

3.1 AOI 1.......................................................................................................................3-1

3.1.1 North Ramp FTA...........................................................................................3-1

3.2 AOI 2.......................................................................................................................3-1

3.2.1 East Ramp AFFF Release Area ...................................................................3-1

3.2.2 Tri-MaxTM Staging Area .................................................................................3-1

3.3 AOI 3.......................................................................................................................3-1

3.3.1 Former Tri-MaxTM Storage ............................................................................3-2

3.4 AOI 4.......................................................................................................................3-2

3.4.1 Former Storage Area....................................................................................3-2

3.5 AOI 5.......................................................................................................................3-2

3.5.1 Wash Rack ...................................................................................................3-2

3.6 Adjacent Sources....................................................................................................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......................................................................................4-5

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
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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 Synoptic Water Level Measurements .....................................................................5-4

5.5 Surveying................................................................................................................5-4

5.6 Investigation-Derived Waste ...................................................................................5-4

5.7 Laboratory Analytical Methods................................................................................5-5

5.8 Deviations from SI QAPP Addendum .....................................................................5-5

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 .........................................................6-3

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 .........................................................6-4

6.4.3 AOI 2 Conclusions........................................................................................6-4

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........................................................................................6-5

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

6.7 AOI 5.......................................................................................................................6-6

6.7.1 AOI 5 Soil Analytical Results ........................................................................6-6

6.7.2 AOI 5 Groundwater Analytical Results .........................................................6-6

6.7.3 AOI 5 Conclusions........................................................................................6-6

6.8 Sitewide ..................................................................................................................6-6

6.8.1 Sitewide Soil Analytical Results....................................................................6-7

6.8.2 Sitewide Groundwater Analytical Results .....................................................6-7

6.8.3 Sitewide Conclusions ...................................................................................6-7

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

7.1.5 AOI 5 ............................................................................................................7-2

7.2 Groundwater Exposure Pathway ............................................................................7-3

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

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

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

7.2.5 AOI 5 ............................................................................................................7-4

7.3 Surface Water and Sediment Exposure Pathway...................................................7-4

7.3.1 AOI 1 ............................................................................................................7-4

7.3.2 AOI 2 ............................................................................................................7-4

7.3.3 AOI 3 ............................................................................................................7-5

7.3.4 AOI 4 ............................................................................................................7-5

7.3.5 AOI 5 ............................................................................................................7-5

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. Log of Daily Notice of Field Activities

B2. Sampling Forms

B3. Survey Data

B4. Investigation-Derived Waste Polygons

Appendix C Photographic Log

Appendix D TPP Meeting Minutes

Appendix E Boring Logs

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, September, 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 4

Figure 7-2 Conceptual Site Model, AOI 3

Figure 7-3 Conceptual Site Model, AOI 5

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 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

°C degrees Celsius

°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

DPT direct push technology

DQI data quality indicator

DQO data quality objective

DUA data usability assessment

DVR data validation report 

EIS extraction internal standards

ELAP Environmental Laboratory Accreditation Program

EPD Environmental Protection Division

ERB equipment rinsate blank

FedEx Federal Express

FRB field reagent blank

FTA Fire Training Area

GAARNG Georgia Army National Guard

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

LOD limit of detection

LOQ limit of quantitation

MDL method detection limit

MS matrix spike

MSD matrix spike duplicate
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NELAP National Environmental Laboratory Accreditation Program

NEtFOSAA N-ethyl perfluorooctanesulfonamidoacetic acid

ng/L nanograms per liter

NMeFOSAA N-methyl perfluorooctanesulfonamidoacetic acid

OSD Office of the Secretary of Defense

PA Preliminary Assessment

PFAS per- and polyfluoroalkyl substances

PFBA perfluorobutyrate

PFBS perfluorobutanesulfonic acid

PFCs perfluorinated compounds

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

PQAPP Programmatic UFP-QAPP

PVC polyvinyl chloride

QA quality assurance

QAPP Quality Assurance Project Plan

QC quality control

QSM Quality Systems Manual

RI Remedial Investigation

RPD relative percent differences

SI Site Inspection

SL screening level

SOP standard operating procedure

TOC total organic carbon

TPP Technical Project Planning

UFP Uniform Federal Policy

US United States

USACE United States Army Corps of Engineers

USCS Unified Soil Classification System

USEPA United States Environmental Protection Agency

USFWS United States Fish and Wildlife Service
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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). A SI was completed at

Winder Barrow Army Aviation Support Facility (AASF) in Winder, Georgia. Winder Barrow AASF

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

The AASF is located in Barrow County, Winder, Georgia, at the Barrow County Airport. The AASF 

is north of Atlanta Highway, west of Bowman Mill Road, south of Highway 82, and east of 

Picklesimon Road. The communities of Bethlehem, Winder, Statham, Bogart, Auburn, and 

Dacula, Georgia lie within 15 miles of the AASF. The AASF is constructed on a 32.9-acre parcel 

of land owned by the Georgia ARNG since 1967. The AASF currently contains several buildings, 

two hangars, and three ramp areas. There is no fire suppression system at Winder Barrow AASF.

During the PA for PFAS, two AOIs were identified at the facility: the North Ramp Fire Training Area 

(FTA) and East Ramp AFFF Release Area. PFAS-containing materials were potentially released 

to soil and groundwater within the boundary of Winter Barrow AASF through fire training 

exercises. Three additional AOIs, the Tri-MaxTM Storage Area, Former Storage Area, and Wash 

Rack, have been identified since the PA based on historic AFFF storage. The SI field activities 

were conducted on 16 July 2021 and from 27 to 30 September 2021, and they 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 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 

5.9 of this Report.

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 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.

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 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, PFOA, PFOS, and PFBS in groundwater exceeded their respective 

individual SLs at temporary well locations (AOI01-01 and AOI01-02), with maximum 

concentrations of 1,740 nanograms per liter (ng/L) (AOI01-02), 7,350 ng/L (AOI01-
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02), and 1,220 ng/L (AOI01-01), respectively. 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 exceeded their respective individual SLs 

at all temporary well locations (AOI02-01 through AOI02-03), with maximum

concentrations of 181 (J+, estimated concentration biased high) ng/L (AOI02-01) and 

1,210 J ng/L (AOI02-01), respectively. Based on the results of the SI, further

evaluation of AOI 2 is warranted in the RI.

• At AOI 3, detected concentrations of PFOA, PFOS, and PFBS in groundwater were 

below SLs. 

• At AOI 4, PFOA and PFOS in groundwater exceeded their respective individual SLs 

at all l location AOI04-01 with concentrations of 622 ng/L and 62,700 ng/L, 

respectively. Based on the results of the SI, further evaluation of AOI 4 is warranted 

in the RI.

• At AOI 5, PFOA and PFOS in groundwater exceeded their respective individual SLs 

at both temporary well locations (AOI05-01 and AOI05-02) with maximum

concentrations of 410 ng/L (AOI05-02) and 1,210 ng/L (AOI05-01), respectively. 

Based on the results of the SI, further evaluation of AOI 5 is warranted in the RI.

• At WB-01 and WB-02, PFOS in groundwater exceeded its SL with concentrations of 

219 ng/L and 151 ng/L, respectively. Based on the results of the SI, further evaluation 

of the facility upgradient and downgradient areas is warranted in the RI.

• The detected concentrations of PFOS in surface soil at AOI 5 exceeded the SL at both 

locations (AOI05-01 and AOI05-02), with a maximum concentration of 639 μg/kg at 

AOI05-01.

• The detected concentrations of PFOA, PFOS, and PFBS in soil at AOI 1 through AOI 

4 were below the SLs.

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

models developed and revised in light of the SI findings, there is potential for exposure to onsite 

workers, future construction workers, and trespassers via inhalation of dust, ingestion of surface 

soil, and ingestion of surface water and/or sediment; potential for exposure to future construction 

workers via ingestion of subsurface soil and shallow groundwater; potential for exposure to offfacility recreational users via ingestion of surface water and/or sediment; and potential for 

exposure to off-facility residents via ingestion of shallow groundwater 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 an RI. Based on the results of this SI, further evaluation 

is warranted in the RI for AOI 1: North Ramp FTA, AOI 2: East Ramp AFFF Release Area and TriMaxTM Staging Area, AOI 4: Former Storage Area, and AOI 5: Wash Rack.
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Table ES-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 

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 Perfluorooctanoic Acid (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 

Perfluorooctane Sulfonic Acid (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.

Table ES-2: Summary of Site Inspection Findings

AOI Potential PFAS 

Release Area

Soil –

Source Area

Groundwater –

Source Area

Groundwater –

Facility Boundary

1 North Ramp FTA

2

East Ramp AFFF 

Release Area

Tri-MaxTM Staging Area

3 Former Tri-MaxTM 

Storage

4 Former Storage Area

5 Wash Rack

Sitewide Location 

– Upgradient Unknown N/A

Sitewide Location 

– Downgradient 

Potential Facility 

Releases N/A

Legend:

N/A = not applicable 

= 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 North Ramp FTA

Exceedances of SLs in groundwater at 

source area and in the downgradient 

direction. No exceedances of SLs in soil. 

Proceed to RI 

2 

East Ramp AFFF 

Release

Exceedances of SLs in groundwater at 

source area and in the downgradient 

direction. No exceedances of SLs in soil. 

Proceed to RI 

Tri-MaxTM Staging 

Area

Exceedances of SLs in groundwater at 

source area. No exceedances of SLs in 

soil. 

Proceed to RI 

3 Former Tri-MaxTM

Storage

Detections in groundwater but no 

exceedances of SLs. No exceedances of 

SLs in soil.

No further action

4 Current Tri-MaxTM

Storage

Exceedances of SLs in groundwater at 

source area. No exceedances of SLs in 

soil. 

Proceed to RI 

5 Wash Rack

Exceedances of SLs in groundwater at 

source area and in the downgradient 

direction. Exceedances of SLs in soil at the 

source area and in the downgradient 

direction. 

Proceed to RI 
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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 Winder Barrow 

Army Aviation Support Facility (AASF) in Winder, Georgia. Winder Barrow AASF 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 Winder Barrow AASF (AECOM, 2020) that identified two potential PFAS 

release areas at the facility, which were grouped into Areas of Interest (AOIs). Three additional 

AOIs have been identified since the PA based on historic aqueous film forming foam (AFFF)

storage. 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

The Winder Barrow AASF (Figure 2-1) is in Barrow County near Winder, Georgia, at the Barrow 

County Airport. The AASF is north of Atlanta Highway, west of Bowman Mill Road, south of 

Highway 82, and east of Picklesimon Road. The communities of Bethlehem, Winder, Statham, 

Bogart, Auburn, and Dacula, Georgia lie within 15 miles of the AASF. The AASF is constructed on 

a 32.9-acre parcel of land owned by the Georgia ARNG (GAARNG) since 1967. The AASF 

includes several buildings, two hangars, and three ramp areas. There are no deluge fire 

suppression systems in the Winder Barrow AASF hangar spaces. The Barrow County Fire 

Department provides emergency response services to the facility. 

2.2 Facility Environmental Setting

The City of Winder is in the Piedmont physiographic province, a region characterized by narrow 

valleys, occasional isolated mountains, and rolling hills with modest relief that form the foothills of 

the Blue Ridge Mountains. The boundary of the Piedmont on the southern margin is the fall line, 

which separates the Piedmont from the low-lying Coastal Plains and represents the extent of the 

Mesozoic Atlantic Ocean. The elevation of the facility is approximately 925 feet above mean sea 

level. The topography of the facility is generally level, sloping slightly to the north (Figure 2-2). 

2.2.1 Geology

The AASF is situated on red Piedmont soils derived from the weathering of the underlying 

feldspar-rich igneous rocks such as granitic gneiss, and metamorphic rocks, such as biotitic 

gneiss, mica schist, and amphibolite rocks (Figure 2-3). Mineral resources of this region include 

hard-crushed stone, soapstone, and granite. The Piedmont is topographically composed of rolling 

hills, with ridges and isolated granitic plutons that rise above the landscape of the region 

(University of Georgia, Department of Geology, 2015).

Borings completed as a part of this SI were drilled to depths between 19 and 25 feet below ground 

surface (bgs). The geological data collected from the boreholes indicate that the dominant 

lithology of the unconsolidated material underlying the Winder Barrow AASF is comprised of fineto medium-grained, poorly to well-graded sand. Boring logs showed varying percentages of fines 

(silt and clay, specifically kaolinite), gravel, and weathered rock. Fines in subsurface soil ranged 

from trace amounts to 45%. Trace amounts of micas, such as lepidolite, were also observed. The 

soils observed at the facility have a relatively high hydraulic conductivity, with well-graded sands 

and sand with gravel having the highest conductivity. Weathered bedrock observed at boring 

location AOI02-02 likely has a lower hydraulic conductivity and represents the most impermeable 

material. 

Soil borings across the northern area of the facility showed silty sand with trace to little clay from 

surface to 10 feet bgs. It is possible soil in the northern portion of the facility has been re-graded 

for parking lot construction and leveling. It is unclear whether artificial fill is present in subsurface 

soil. These site observations are consistent with the expected subsurface material conditions. 

2.2.2 Hydrogeology

The AASF is within the boundaries of the Piedmont and Blue Ridge aquifers, both consisting of 

unconsolidated material called regolith overlying the bedrock. The crystalline bedrock formed 

under intense heat and pressure and therefore has few primary pore spaces and very low 

permeability; however, large amounts of water do permeate through fractures in the bedrock and 
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through the regolith (University of Georgia Institute of Ecology, 2002). Wells tapping the Piedmont 

and Blue Ridge crystalline-rock aquifers are typically 150 to 700 feet bgs. The Piedmont and Blue 

Ridge aquifers are used extensively as sources for private wells and public water supply in the 

southeast region of the US (US Geological Survey [USGS], 2017). 

No potable water wells are located within the AASF; however, an EDR Report performed as a 

part of the facility PA (AECOM, 2020) shows wells existing side gradient to and within 1 mile of 

the facility (Figure 2-3). Additionally, real estate listings for multiple homes in the downgradient 

direction describe the residential water source as “well” or “private”, and some have no water 

source listed. Drinking water for the AASF is supplied by the City of Winder Water Works, which 

sources the drinking water from the Mulberry River at the Laurel Lane reservoir and Water Plant 

Reservoirs (City of Winder Water Works, 2019). The Laurel Lane reservoir is approximately 4.8 

miles northwest of the facility, and the Water Plant Reservoir is approximately 4.3 miles northwest 

of the facility. Based on the USEPA’s Unregulated Contaminant Monitoring Rule 3 data, no PFAS 

were detected in a public water system above the USEPA Health Advisory (HA) Level within 20 

miles of the facility (USEPA, 2017a); however, data gaps exist for some of the public water 

systems. The HA is 70 nanograms per liter (ng/L) for PFOA and PFOS, 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.

Groundwater flow within the unconsolidated surficial aquifer at the facility is influenced by surface 

topography. In general, surface topography slopes from the flatter, higher elevations in the 

southeastern portion of the facility towards the drainage canal in the northern portion of the facility.

There is an approximately 15 feet drop from the northern parking areas to the base of the drainage 

canal ravine. It is possible that the slope was steepened by grading during construction of the 

northern parking lot. The drainage canal may act as a draw on groundwater flow. Depths to water 

measured in September 2021 during the SI ranged from 9.58 to 16.29 feet bgs. Groundwater 

elevation contours from the SI are presented on Figure 2-4 and indicate groundwater flow 

direction is generally to the northwest towards the drainage canal on the northern edge of the 

property. 

2.2.3 Hydrology

The AASF is in the Upper Oconee River Basin, more specifically in the Middle Oconee River 

tributary region and in the Beech Creek watershed (Figure 2-5). Regional surface water features 

include Lower Twin Lake, Barber Creek, Rocky Creek, and other small unnamed lakes and 

tributaries. Drainage canals within the AASF boundary lead to Lower Twin Lake to the northwest. 

Drainage canals that are located off-facility to the northeast of the AASF drain to the Rocky Creek 

(Metropolitan North Georgia Water Planning District, 2016). 

2.2.4 Climate

The subtropical climate at the AASF is characterized as short and mild winters, with hot and humid 

summers, and a long spring season. The average temperature is 59.65 degrees Fahrenheit (°F). 

Seasonally, temperatures vary from average highs of 71.5 °F to average lows of 47.8 °F. Average 

precipitation is 53.15 inches (World Climate, 2022).

2.2.5 Current and Future Land Use

The AASF is a controlled access facility and is located at the Barrow County Airport. The Winder 

Barrow County Airport is owned and operated by the City of Winder and provides commercial and 

general air service to the Winder area and northeast Georgia. Reasonably anticipated future land 

use is expected to remain the same.
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2.2.6 Sensitive Habitat and Threatened/ Endangered Species 

The following birds, plants, mammals, and fish are federally endangered, threatened, proposed,

and/ or are listed as candidate species in Barrow County, Georgia (US Fish and Wildlife Service

[USFWS], 2021). 

• Insects: Monarch butterfly, Danaus plexippus (candidate)

• Mammals: Tricolored bat, Perimyotis subflavus (under review)

• Flowering plants: Little amphianthus, Amphianthus pusillus (threatened)

• Ferns and Allies: Black spored quillwort, Isoetes melanospora (endangered)

• Fishes: Robust redhorse, Moxostoma robustum (under review)

2.3 History of PFAS Use

PFAS-containing materials were potentially released to soil and groundwater within the boundary 

of Winder Barrow AASF through fire training exercises, AFFF handling and storage, and general 

maintenance activities. Descriptions of the AOIs are presented in Section 3.
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3. Summary of Areas of Interest 

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

findings, two potential PFAS release areas, the North Ramp Fire Training Area (FTA) and East 

Ramp AFFF Release Area, were identified at Winder Barrow AASF (AECOM, 2020). Three 

additional AOIs have been identified since the PA based on historic AFFF storage (AECOM, 

2021a). The potential PFAS release areas are shown on Figure 3-1.

3.1 AOI 1 

AOI 1 consists of one potential PFAS release area. The release area is described below.

3.1.1 North Ramp FTA

AOI 1 is the FTA located on the north ramp where the City of Atlanta Fire Department visited the 

facility for a fire training course. During the training event, a 55-gallon drum was ignited, and AFFF 

may have been dispensed from a firetruck to douse the fire. No information was available 

regarding concentration or volume of AFFF potentially released. This potential release occurred 

during one event prior to 2004; however, the exact date is unknown.

Historically, the north ramp was completely paved; however, sometime between 1999 and 2005,

the western third of the pavement was removed and left bare ground or gravel cover. The north 

ramp has no storm drains, and surface water flows north, toward a low-lying area in the northern 

corner of the AASF and then to the drainage canal on the northwest border of the AASF, potentially 

releasing PFAS to surface water, sediment, and surface soil.

3.2 AOI 2

AOI 2 consists of two potential PFAS release areas. The release areas are described below.

3.2.1 East Ramp AFFF Release Area

AOI 2 is located southeast of Hangar 2. During an elementary school field trip demonstration,

there was an unintentional release of AFFF from the facility crash rescue firetruck. It is unknown 

if GAARNG fire response assets were used during the fire training demonstration. The AFFF 

release occurred on the ramp directly southeast of Hangar 2. No information is available regarding 

concentration or volume of AFFF potentially released. 

3.2.2 Tri-MaxTM Staging Area

In addition, facility staff stated that, at various times, Tri-MaxTM fire extinguishers have been staged 

on the flight ramp; however, the exact timeframe and locations of Tri-MaxTM fire extinguishers on 

the flight ramp are uncertain. It is presumed that the units were stationed on the east side of the 

main ramp, between aircraft parking positions.

3.3 AOI 3

AOI 3 consists of one potential PFAS release area. The release area is described below.
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3.3.1 Former Tri-MaxTM Storage

AOI 3 is a storage cage located in the center of the facility that was used to house twelve 30-

gallon Tri-MaxTM fire extinguishers; however, since the PA, the units were moved and are currently 

staged at AOI 4, pending transport to an off-site repair facility. There are no Tri-MaxTM units present 

at AOI 3. The Tri-MaxTM fire extinguishers were stationed on the main ramp since approximately 

2003, but it is unknown when they were moved to AOI 3. The units are routinely removed from 

the facility to be serviced by a contractor and are not known to have been dispensed at the facility. 

No information is available regarding the concentration of AFFF used in the fire extinguishers. 

3.4 AOI 4

AOI 4 consists of one potential PFAS release area. The release area is described below

3.4.1 Former Storage Area

AOI 4 is a small garage located on the northeast side of Hangar 2. The garage formerly stored 

the AASF crash rescue firetruck until approximately 2004. The crash rescue firetruck is not known 

to have been used to extinguish fires but may have been used to store AFFF in 5-gallon buckets. 

Bulk AFFF was also stored in the same garage but was removed when the crash rescue firetruck 

was removed in 2004. Additionally, twelve 30-gallon Tri-MaxTM fire extinguishers awaiting offsite 

transport and disposal are currently staged on the southeast side of the garage. The Tri-MaxTM

units are currently full. The small garage has no floor drains, but a bay door opens on the west 

end of the garage to a gravel driveway.

3.5 AOI 5

AOI 5 consists of one potential PFAS release area. The release area is described below

3.5.1 Wash Rack

AOI 5 is the Wash Rack located northwest of Hangar 2. Following the known AFFF release during 

the elementary school field trip demonstration, the former crash rescue firetruck was washed at 

the Wash Rack. It is unclear whether AFFF hose lines were drained or rinsed during that time. 

Additionally, 5-gallon buckets have been temporarily stored in a flammable container adjacent to 

the Wash Rack. No known AFFF releases have been confirmed at AOI 5. The Wash Rack is 

plumbed to a recirculatory system that cycles through to a settling tank. Sediments from the 

settling tank have not been removed since 2005. The settling tank, which was installed in 1997, 

is concrete-lined with a 6-inch concrete bottom.

3.6 Adjacent Sources

In addition to the AOIs identified, two potential off-facility sources of PFAS adjacent to the AASF, 

not under the control of the GAARNG, were identified during the PA. On 26 September 2017 a 

small single prop plane crashed in the wood line of a pasture across from Winder Barrow County 

Airport on Highway 82. AFFF was released by Barrow County Emergency Services in response, 

but no information was available regarding concentration or volume of AFFF potentially released. 

The crash site is downgradient from the AASF. Additionally, the Barrow Airport County Emergency 

Service Department conducts fire training exercises at the Barrow County Airport but does not 

use AFFF for their exercises. There is a fire suppression system present on Barrow County Airport 

property; however, there is no information available regarding the type of suppression system or 

extinguishant used.
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Tri-MaxTM Staging Area

AOI 2

AOI 1

AOI 3

AOI 4

AOI 5 Former Storage Area

Wash Rack

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Winder Barrow County Airport

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East Ramp AFFF Release Area

Non-AFFF

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Former Tri-MaxTM Storage

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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 the 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.

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 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:
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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.

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 Winder Barrow AASF (AECOM, 2020); 

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

with the site-specific Uniform Federal Policy (UFP)-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 not included in the scope of this SI. If future off-facility sampling is required, the proper 

stakeholders will be notified, and necessary rights of entry will be obtained by ARNG with property 

owner(s).

4.5 Analytical Approach

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

Laboratory Accreditation Program (DoD 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? 
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• What is the concentration of PFOA, PFOS, and PFBS at the facility boundary upgradient 

and downgradient of the potential release areas? 

• 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 potential release areas. 

Groundwater was encountered at approximately 9.56 to 22.5 feet bgs. 

4.6 Data Usability Assessment

The Data Usability Assessment (DUA) 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.

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 (DVR) (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.

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

calibrated analytes were within established QC criteria. No associated calibration verifications 

displayed results outside the project established precision limits presented in the QAPP 

Addendum (AECOM, 2021a). 

LCS/laboratory control spike 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/LCSD samples were within the project established precision limits presented in the QAPP 

Addendum (AECOM, 2021a). 
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MS/matrix spike 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 percent (%). The MS/MSD samples were within the project established precision limits 

presented in the 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 QAPP Addendum (AECOM, 2021a) with several 

exceptions. Several field duplicate pairs displayed one non-detect result for a compound while 

the associated field duplicate sample displayed a positive result. The non-detect parent sample 

result was qualified UJ,fd while the positive duplicate sample result was qualified J,fd. The 

qualified field duplicate pair results should be considered usable as estimated values.

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/LCSD samples were within the project established accuracy 

limits presented in the QAPP Addendum (AECOM, 2021a). 

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/MSD 

samples were within the project established control limits presented in the QAPP Addendum 

(AECOM, 2021a) with limited exceptions. Parent samples AOI02-01-GW and AOI01-02-SB-16-

18 displayed MS/MSD percent recoveries outside the project established control limits for multiple 

target analytes. In field sample AOI02-01-GW, the native sample results for multiple analytes 

displayed concentrations greater than four times the spike values; these recoveries were not 

applicable for qualification and the field sample results should be considered usable as reported. 

The positive field sample result associated with low MS/MSD recoveries was qualified as estimate 

with a positive bias. The positive field sample result with associated high MD/MSD recoveries was 

qualified as estimate with a negative bias. The positive field sample result associated with the 

indeterminate bias was qualified as estimate. These field sample results should be considered 

usable as qualified as estimated values.

Extraction internal standards (EIS) were added by the laboratory during sample extraction to 

measure relative responses of target analytes and used to correct for bias associated with matrix 

interferences and sample preparation efficiencies, injection volume variances, mass spectrometry 

ionization efficiencies, and other associated preparation and analytical anomalies. The EIS 

samples were within the project established accuracy limits presented in the QAPP Addendum 

(AECOM, 2021a). 

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

to analysis as a legacy requirement of DoD 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 QC measure. The IIS percent recoveries 

were outside the established precision limits presented in the QAPP Addendum (AECOM, 2021a) 
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for several analytes. The impact on data usability was not assessed and the field samples were 

re-analyzed by the laboratory to confirm the initial results. Data quality was not impacted by IIS 

percent recoveries outside the established precision limits because PFAS analytes are not 

quantitated based on IIS recoveries.

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 

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 tandem mass spectrometry (LC/MS/MS)

Compliant with Quality Systems Manual (QSM) 5.3 Table B-15, including the specific preparation 

requirements (i.e. ENVI-Carb 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%. The laboratory used approved standard methods in accordance with the 

QAPP Addendum (AECOM, 2021a) for all analyses. All technical and analytical holding times 

were met by the laboratory for the initial results with limited exceptions. The holding time for pH 

analysis is considered ‘immediate’ so all pH sample results have been qualified as estimate. 

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

control. One instrument and one method blank displayed target analyte concentrations greater 

than the detection limit (DL). Two decontamination samples were qualified “U” during data 

validation due to associated detection in the method blank. The reported decon sample result 

values were adjusted to be equal to the limit of detection (LOD); the LOD was elevated to the 

concentration of the blank detection in instances where the blank concentration was greater than 

the LOD. The results are usable as qualified but should be considered false positives and treated 

as non-detect. The remaining field sample results associated with the blank detection were nondetect or displayed concentrations greater than five times the blank concentrations.

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

field blank WB-ERB-01 displayed a concentration for PFOS greater than the DL. The associated 

field sample results that displayed positive results less than five times the blank detection were 

qualified “U” during data validation. The results are usable as qualified but should be considered 

false positives and treated as non-detect. The reported field sample result values were adjusted 

to be equal to the limit of detection (LOD); the LOD was elevated to the concentration of the blank 

detection in instances where the blank concentration was greater than the LOD.

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

field effort. The blank samples WB-DECON-01, WB-DECON-02, and DRUM-DECON-01 

displayed concentrations greater than the DL for multiple target analytes. The associated field 

sample results were non-detect or displayed positive results greater than five times the blank 

detections. 

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.
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 4-6

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/UX” flagged data, if applicable:

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

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

• 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 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 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.
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 5-1

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 Programmatic Accident Prevention Plan dated July 2018 (AECOM, 2018b);

• Final Preliminary Assessment Report, Winder Barrow AASF dated February 2020 (AECOM, 

2020);

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

Winder Barrow AASF dated September 2021 (AECOM, 2021a); and

• Final Site Safety and Health Plan, Winder Barrow AASF dated September 2021 (AECOM, 

2021b).

The SI field activities were conducted on 16 July 2021, and from 27 to 30 September 2021 and 

consisted of decontamination water source sampling, utility clearance, direct push boring, soil 

sample collection, temporary 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 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:

• 38 soil samples from 11 boring locations;

• 11 grab groundwater samples from 11 temporary well locations; and

• 17 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, land survey data are provided in 

Appendix B3, and investigation-derived waste (IDW) polygons are provided in Appendix B4.

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 

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. 
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Winder Barrow Army Aviation Support Facility, Georgia

AECOM 5-2

A combined TPP Meeting 1 and 2 was held on 30 August 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, GAARNG, and USACE. The Georgia Department of 

Environmental Protection was invited but did not attend the meeting. 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 was held on 9 May 2022 to discuss the results of the SI. Meeting minutes for 

the TPP 3 are 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 placed a ticket with the Georgia 811 “Call Before You Dig” utility clearance provider to 

notify them of intrusive work on 14 September 2021. By 24 September 2021, Georgia 811 

coordinated the utility clearance of all proposed boring locations for electric, telecommunication, 

gas, and water lines. Additionally, AECOM contracted Ground Penetrating Radar Systems, LLC.

(GPRS), a private utility location service, to perform utility clearance. GPRS performed utility 

clearance of the proposed boring locations on 27 September 2021 with input from the AECOM 

field team. General locating services and ground-penetrating 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 Winder Barrow AASF was collected on 16 July 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. 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 direct push technology (DPT) and hand auger, in accordance with 

the SI QAPP Addendum (AECOM, 2021a). A GeoProbe® 7822DT dual-tube sampling system was 

used to collect continuous soil cores to the target depth. A hand auger was used to collect soil 

from the top five 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 in Table 5-1. Photographs 

of the soil cores are included in Appendix C. 

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 approximately 

2 feet above the groundwater table, and one subsurface soil sample at the mid-point between the 

surface and the groundwater table. Five additional locations were identified for only surface soil 

samples; at each location samples were collected from 0 to 2 feet bgs. 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 5-3

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 fine to fine- to medium-grained, poorly to well-graded 

sand as the dominant lithology of the unconsolidated material below the Winder Barrow AASF. 

Boring logs showed varying percentages of fines (silt and clay, specifically kaolinite), gravel, and 

weathered rock. Fines in subsurface soil ranged from trace amounts to 45%. Trace amounts of 

micas, such as lepidolite, were also observed. The soils observed at the facility have a relatively 

high hydraulic conductivity, with well-graded sands and sand with gravel having the highest 

conductivity. The borings were completed at depths between 19 and 25 feet bgs.

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, ERBs 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.

All DPT borings were converted to temporary wells, which were subsequently abandoned in 

accordance with the SI QAPP Addendum (AECOM, 2021a) using bentonite chips at completion 

of sampling activities. In general, most borings were installed in grass areas to avoid disturbing 

concrete or asphalt surfaces. One boring was advanced in a paved parking area. The locations 

where only surface soil samples were collected were not converted to temporary wells for 

groundwater sampling.

5.3 Temporary Well Installation and Groundwater Grab Sampling

Eleven temporary wells were installed using a GeoProbe® 7822DT dual-tube sampling system. 

Once the borehole was advanced to the desired depth, 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 peristaltic 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, 

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. No foaming was noted in any of the groundwater samples.
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 5-4

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 

Programmatic UFP-QAPP (PQAPP) (AECOM, 2018a). 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. Most temporary wells were 

installed in grass areas to avoid disturbing concrete or asphalt; one temporary well was installed 

in paved parking lot.

5.4 Synoptic Water Level Measurements

A synoptic groundwater gauging event was performed on 30 September 2021. Groundwater

elevation measurements were collected from the 11 temporary monitoring wells. Water level 

measurements were taken from the northern side of the well casing. A groundwater flow contour 

map is provided in Figure 2-5. Groundwater elevation data is provided in Table 5-2.

5.5 Surveying

The northern side of each well casing was surveyed by GeoSurvey, Ltd., a Georgia-licensed land 

surveyor, following guidelines provided in the SOPs provided in the SI QAPP Addendum 

(AECOM, 2021a). Survey data from the newly installed temporary monitoring wells on the facility

were collected on 30 September 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 B3.

5.6 Investigation-Derived Waste

As of the date of this report, the disposal of PFAS 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).

Soil IDW (i.e., soil cuttings) generated during the SI activities were left in place at the point of the 

source. The soil cuttings were distributed on the ground surface on the downgradient side of the 

boring. The soil IDW was not sampled and assumes the PFAS characteristics of the associated 

soil samples collected from that source location. 

Liquid IDW generated during SI activities (i.e. purge water, development water, and 

decontamination fluids) were discharged directly to the ground surface slightly downgradient of 

the source. The liquid IDW was not sampled and assumes the PFAS characteristics of the 

associated groundwater samples collected from that source location.

The locations where IDW was placed (i.e., an IDW polygon) are displayed on the figure in 

Appendix B4.

Other solids such as spent personal protective equipment, plastic sheeting, tubing, rope, and 

unused monitoring well construction materials generated during the field activities were disposed 

of as non-hazardous solid waste to be transported to a licensed solid waste landfill.
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 5-5

5.7 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:

• 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.

5.8 Deviations from SI QAPP Addendum

No deviations from the SI QAPP Addendum were necessary to complete SI field work. 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 5-6

THIS PAGE INTENTIONALLY BLANK
Table 5-1

Site Inspection Samples by Medium

Site Inspection Report, Winder Barrow AASF, Georgia

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)

Comments

AOI01-01-SB-0-2 9/28/2021 9:30 0 - 2 x

AOI01-01-SB-0-2-A 9/28/2021 9:30 0 - 2 x FD

AOI01-01-SB-9-11 9/28/2021 9:45 9 - 11 x

AOI01-01-SB-18-20 9/28/2021 9:55 18 - 20 x

AOI01-02-SB-0-2 9/28/2021 10:30 0 - 2 x x x

AOI01-02-SB-0-2-A 9/28/2021 10:30 0 - 2 x x FD

AOI01-02-SB-02-MS 9/28/2021 10:30 0 - 2 x MS

AOI01-02-SB-0-2-MSD 9/28/2021 10:30 0 - 2 x MSD

AOI01-02-SB-8-10 9/28/2021 10:55 8 - 10 x

AOI01-02-SB-16-18 9/28/2021 11:05 16 - 18 x

AOI01-02-SB-16-18-MS 9/28/2021 11:05 16 - 18 x MS

AOI01-02-SB-16-18-MSD 9/28/2021 11:05 16 - 18 x MSD

AOI02-01-SB-0-2 9/27/2021 14:35 0 - 2 x

AOI02-01-SB-9-11 9/27/2021 14:55 9 - 11 x

AOI02-01-SB-9-11-A 9/27/2021 14:55 9 - 11 x FD

AOI02-01-SB-18-20 9/27/2021 15:05 18 - 20 x x x

AOI02-02-SB-0-2 9/27/2021 12:35 0 - 2 x

AOI02-02-SB-7-9 9/27/2021 12:45 7 - 9 x

AOI02-02-SB-16-18 9/27/2021 12:55 16 - 18 x

AOI02-03-SB-0-2 9/27/2021 15:30 0 - 2 x

AOI02-03-SB-10-12 9/27/2021 15:40 10 - 12 x

AOI02-03-SB-19-21 9/27/2021 15:50 19 - 21 x

AOI02-04-SB-0-2 9/30/2021 8:05 0 - 2 x

AOI02-05-SB-0-2 9/30/2021 8:15 0 - 2 x

AOI02-06-SB-0-2 9/30/2021 8:25 0 - 2 x

AOI02-07-SB-0-2 9/30/2021 8:35 0 - 2 x

AOI02-08-SB-0-2 9/30/2021 8:45 0 - 2 x

AOI03-01-SB-0-2 9/28/2021 13:10 0 - 2 x x

AOI03-01-SB-10-12 9/28/2021 13:35 10 - 12 x

AOI03-01-SB-20-22 9/28/2021 13:45 20 - 22 x

AOI03-01-SB-20-22-A 9/28/2021 13:45 20 - 22 x FD

AOI04-01-SB-0-2 9/29/2021 8:20 0 - 2 x x

AOI04-01-SB-8-10 9/29/2021 8:45 8 - 10 x

AOI04-01-SB-18-20 9/29/2021 8:55 18 - 20 x

AOI05-01-SB-0-2 9/28/2021 14:30 0 - 2 x

AOI05-01-SB-7-9 9/28/2021 14:45 7 - 9 x

AOI05-01-SB-14-16 9/28/2021 14:55 14 - 16 x x

AOI05-02-SB-0-2 9/28/2021 16:00 0 - 2 x

AOI05-02-SB-0-2-A 9/28/2021 16:00 0 - 2 x FD

AOI05-02-SB-7-9 9/28/2021 16:10 7 - 9 x

AOI05-02-SB-13-15 9/28/2021 16:20 13 - 15 x

WB-01-SB-0-2 9/27/2021 13:35 0 - 2 x x x

WB-01-SB-0-2-MS 9/27/2021 13:35 0 - 2 x MS

WB-01-SB-0-2-MSD 9/27/2021 13:35 0 - 2 x MSD

WB-01-SB-10-12 9/27/2021 13:55 10 - 12 x

WB-01-SB-20-22 9/27/2021 14:05 20 - 22 x

WB-02-SB-0-2 9/28/2021 12:05 0 - 2 x

WB-02-SB-9-11 9/28/2021 12:15 9 - 11 x

WB-02-SB-18-20 9/28/2021 12:25 18 - 20 x

Soil Samples

AECOM 5-7
Table 5-1

Site Inspection Samples by Medium

Site Inspection Report, Winder Barrow AASF, Georgia

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)

Comments

AOI01-01-GW 9/29/2021 8:30 NA x

AOI01-02-GW 9/28/2021 16:30 NA x

AOI01-02-GW-A 9/28/2021 16:30 NA x FD

AOI02-01-GW 9/28/2021 11:15 NA x

AOI02-01-GW-MS 9/28/2021 11:15 NA x MS

AOI02-01-GW-MSD 9/28/2021 11:15 NA x MSD

AOI02-02-GW 9/28/2021 12:50 NA x

AOI02-03-GW 9/28/2021 10:00 NA x

AOI03-01-GW 9/29/2021 12:15 NA x

AOI03-01-GW-A 9/29/2021 12:15 NA x FD

AOI04-01-GW 9/29/2021 14:00 NA x

AOI05-01-GW 9/29/2021 16:45 NA x

AOI05-02-GW 9/29/2021 15:30 NA x

WB-01-GW 9/28/2021 14:00 NA x

WB-02-GW 9/29/2021 10:30 NA x

WB-ERB-01 9/28/2021 12:35 NA x from hand auger

WB-ERB-02 9/28/2021 15:00 NA x from hand auger

WB-FRB-01 9/29/2021 14:10 NA x

WB-DECON-01 7/16/2021 11:30 NA x

from hose connecting to 

decon water source spigot

WB-DECON-02 7/16/2021 11:40 NA x

from decon water source 

spigot

Drum-DECON-01 9/28/2021 8:20 NA x

from drill rig decon water 

container

Quality Control Samples

Groundwater Samples

Notes:

AOI = area of interest

ASTM = American Society for Testing and Materials

bgs = below ground surface

DECON = decontamination

ERB = equipment rinsate blank

FD = field duplicate

FRB = field reagent blank

GW = groundwater

LC/MS/MS = Liquid Chromatography Mass Spectrometry

NA = not applicable

MS/MSD = matrix spike/ matrix spike duplicate

PFAS = per- and polyfluoroalkyl substances

pH = potential of hydrogen; quantitative measure of the acidity or basicity of aqueous or other liquid solutions

QSM = Quality Systems Manual

SB = soil boring

TOC = total organic carbon

USEPA = United States Environmental Protection Agency

WB = Winder Barrow

AECOM 5-8
Table 5-2

Soil Boring Depths, Temporary Well Screen Intervals, and Groundwater Elevations

Site Inspection Report, Winder Barrow AASF, Georgia

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 

AOI01-01 25 19.8 - 24.8 911.71 911.39 14.44 14AOI01-02 25 14.88 - 19.88 913.37 913.31 14.07 14AOI02-01 25 15.2 - 20.2 921.80 921.28 13.02 12AOI02-02 20 15 - 20 919.30 918.66 11.1 10AOI02-03 25 20 - 25 921.60 920.67 12.22 11AOI02-04 2 NA NA 919.70 NA NAOI02-05 2 NA NA 919.05 NA NAOI02-06 2 NA NA 918.83 NA NAOI02-07 2 NA NA 918.90 NA NAOI02-08 2 NA NA 918.35 NA N

3 AOI03-01 25 19.83 - 24.83 919.43 918.75 15.65 14

4 AOI04-01 25 16 - 21 924.46 920.66 16.11 12

AOI05-01 20 15 - 20 919.35 917.75 13.72 12AOI05-02 20 14.79 - 19.79 921.90 919.49 14.14 11

WB-01 25 20 - 25 918.71 917.79 10.49 9.5

WB-02 24 19 - 24 912.39 911.56 17.12 16

Notes:

AOI = area of interest

bgs = below ground surfacebtoc = below top of casingNA = not applicableNAVD88 = North American Vertical Datum 1988WB = Winder Barrow

125

Sitewide

AECOM 5-6

AECOM 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 5-10

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AOI 2

AOI 1

AOI 3

AOI 5 AOI 4

Former Storage Area

Wash Rack

Former Tri-MaxTM Storage

North Ramp FTA

East Ramp 

AFFF Release Area

AOI1-01

AOI1-02

AOI2-01 AOI2-02

AOI3-01 AOI4-01

AOI5-01

AOI5-02

WB-01

WB-02

AOI2-03

AOI2-04

AOI2-05

AOI2-06

AOI2-07

AOI2-08

0 165 330 660

Feet

Legend

?! Soil Boring/Groundwater Sample

"S Surface Soil Sample

Area of Interest

Potential PFAS Release

Facility Boundary

River/Stream

Surface Water Flow Direction

Groundwater Flow Direction

Site Inspection Sample Locations

Figure 5-1

CLIENT

REVISED

SCALE

2/3/2022 MS

JW

2/3/2022

2/3/2022

ARNG

GIS BY

CHK BY

PROJECT Site Inspection for PFAS at Winder Barrow AASF, GA

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\GA\WinderBarrow_Figures\SI_Figures\SI_Report\Fig_5-1_WinderBarrow_SI_Sample_Locations.mxd

PM CM 2/3/2022

1:3,960 ­ 12420 Milestone Center Drive

Germantown, MD 20876

Base Map: Source: Esri, Maxar, GeoEye, Earthstar Geographics, CNES/Airbus DS,

USDA, USGS, AeroGRID, IGN, and the GIS User Community

AECOM 5-11
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 5-12

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Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

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 6.8. Table 6-2 through Table 6-5 present PFAS results for samples with 

detections in soil and 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 

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 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

Winder Barrow Army Aviation Support Facility, Georgia

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 one potential PFAS release area: the North Ramp FTA. 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 the 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 three intervals at boring locations AOI01-01 and AOI01-02. Samples were 

collected from surface soil (0 to 2 feet bgs), shallow subsurface soil (8 to 11 feet bgs), and deep 

subsurface soil (16 to 20 feet bgs). PFOA, PFOS, and PFBS were detected in soil at 

concentrations below the respective SLs. PFOA was not detected in surface or shallow 

subsurface soil at location AOI01-01. PFOA was detected in surface soil at location AOI01-02,

with a concentration of 0.239 (J, estimated concentration) micrograms per kilogram (μg/kg). PFOA 

was not detected in shallow subsurface soil at location AOI01-02. PFOS was detected in surface 

soil at locations AOI01-01 and AOI01-02, with concentrations ranging from 0.337 J μg/kg to 2.71

μg/kg. PFOS was not detected in shallow subsurface soil at these locations. PFBS was not 

detected in surface soil at location AOI01-01. PFBS was detected in surface soil at location AOI01-

02, with a concentration of 0.034 J μg/kg. PFBS was not detected in shallow subsurface soil at 

locations AOI01-01 or AOI01-02.

PFOA was not detected in deep subsurface soil at location AOI01-01. PFOA was detected at

location AOI01-02, with a concentration of 0.512 J- μg/kg in the deep subsurface soil. PFOS was 

detected in deep subsurface soil at locations AOI01-01 and AOI01-02, with concentrations of 4.15 

μg/kg and 2.46 J μg/kg, respectively. PFBS was detected in deep subsurface soil at locations

AOI01-01 and AOI01-02, with of 0.110 J μg/kg and 0.134 J μg/kg, respectively. 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 6-3

6.3.2 AOI 1 Groundwater Analytical Results

PFOA, PFOS and PFBS in groundwater exceeded 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 from temporary monitoring well locations AOI01-01 and AOI01-02 at 

the North Ramp FTA. The SL of 40 ng/L for PFOA was exceeded at AOI01-01 and AOI01-02, with

concentrations of 506 ng/L and 1,740 ng/L (Duplicate), respectively. The SL of 40 ng/L for PFOS 

was exceeded at AOI01-01 and AOI01-02, with concentrations of 7,180 ng/L and 7,350 ng/L

(Duplicate), respectively. Both maximum concentrations occurred at location AOI01-02, which is 

adjacent to the ramp. PFBS was detected above the SL of 600 ng/L at location AOI01-01, with a 

concentrations of 1,220 ng/L. PFBS was detected at location AOI01-02 below its respective SL, 

with a maximum concentration of 464 ng/L (Duplicate).

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 soil SLs. PFOA, PFOS, and PFBS were detected in groundwater at 

concentrations exceeding their respective individual SLs of 40 ng/L (PFOA and PFOS) and 600 

ng/L (PFBS). Based on the exceedances of the SLs for PFOA, PFOS, and PFBS 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 two potential PFAS release areas: the East Ramp AFFF Release Area and TriMaxTM Staging Area. The detected compounds in soil and groundwater are summarized on Table 

6-2 through Table 6-4. The detections of PFOA, PFOS, and PFBS in soil and groundwater are 

presented on Figure 6-1 through Figure 6-4.

6.4.1 AOI 2 Soil Analytical Results

PFOA and PFOS did not exceed the SLs in soil at AOI 2. PFBS was not detected 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.

Soil was sampled from three intervals at boring locations AOI02-01, AOI02-02, and AOI02-03. 

The samples were collected from surface soil (0 to 2 feet bgs), shallow subsurface soil (7 to 12

feet bgs), and deep subsurface soil (16 to 21 feet bgs). Surface soil was also sampled from one 

interval at boring locations AOI02-04 through AOI02-08. PFOA and PFOS were detected in soil 

with concentrations below the SLs, and PFBS was not detected in soil. PFOA was detected in 

surface soil at five locations, with concentrations ranging from 0.102 J μg/kg (AOI02-06) to 0.440 

J μg/kg (AOI02-02). PFOA was not detected at in shallow subsurface soil. PFOS was detected in 

surface soil at seven locations with concentrations ranging from 0.182 J μg/kg (AOI02-06) to 7.91

μg/kg (AOI02-02). PFOS was detected in shallow subsurface soil at three locations with 

concentrations ranging from 0.163 J μg/kg (AOI02-03) to 0.810 J μg/kg (AOI02-01). PFBS was 

not detected at any locations in surface and shallow subsurface soil. 

PFOA was detected in the deep subsurface soil at location AOI102-02, with a concentration of 

0.586 J μg/kg. PFOA was not detected in deep subsurface soil at any other locations. PFOS was

detected in deep subsurface soil at locations AOI02-01 and AOI02-02, with concentrations

ranging from of 0.748 J μg/kg to 0.900 J μg/kg. PFBS was not detected in deep subsurface soil. 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 6-4

6.4.2 AOI 2 Groundwater Analytical Results

PFOA and PFOS in groundwater exceeded the SLs at AOI 2. 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 temporary monitoring well locations AOI02-01 through AOI02-03

at the East Ramp AFFF Release Area. The SL of 40 ng/L for PFOA was exceeded at AOI02-01, 

AOI01-02, and AOI02-03, with concentrations of 181 J+ ng/L, 42 ng/L, and 104 ng/L, respectively. 

The SL of 40 ng/L for PFOS was exceeded at AOI02-01, AOI01-02, and AOI02-03, with 

concentrations of 1,210 J ng/L, 1,060 ng/L, and 42.3 ng/L, respectively. PFBS was detected below 

the SL of 600 ng/L at all locations, with concentrations ranging from 3.95 J ng/L to 42.5 ng/L. The 

maximum concentrations occurred at AOI02-01, which is adjacent to the East Ramp AFFF 

Release Area. 

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 their 

respective soil SLs. PFOA and PFOS were detected in groundwater at concentrations exceeding 

their respective individual SLs of 40 ng/L. 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 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 one potential PFAS release area: the Former Tri-MaxTM Storage Area. The 

detected compounds in soil and groundwater are presented in Table 6-2 through Table 6-4. 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 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 three intervals at boring location AOI03-01. The samples were collected 

from surface soil (0 to 2 feet bgs), shallow subsurface soil (10 to 12 feet bgs), and deep subsurface 

soil (20 to 22 feet bgs). PFOA, PFOS, and PFBS were detected at concentrations below the SLs. 

PFOA and PFOS were detected in surface soil, with concentrations of 0.587 J μg/kg and 5.09 

μg/kg, respectively. PFBS was detected in shallow subsurface soil, with a concentration of 0.026 

J μg/kg. PFOA, PFOS, and PFBS were not detected in deep subsurface soil.

6.5.2 AOI 3 Groundwater Analytical Results

PFOA, PFOS, and PFBS in groundwater from temporary monitoring well location AOI03-01 did 

not exceed the SLs at AOI 3. 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 temporary monitoring well location AOI03-01, which is 

downgradient from the Former Tri-MaxTM Storage Area. PFOA and PFBS were detected at 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 6-5

concentrations below the SLs, and PFOS was not detected. The maximum concentrations of 

PFOA and PFBS were 36.9 ng/L and 21.0 ng/L, respectively.

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 several orders of 

magnitude lower than the soil SLs. PFOA and PFBS was detected in groundwater at 

concentrations below their respective SLs of 40 ng/L and 600 ng/L. PFOS was not detected in 

groundwater at AOI 3. Because PFOA, PFOS, and PFBS did not exceed SLs in soil or 

groundwater, further evaluation at AOI 3 is not 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: the Former Storage Area. The detected 

compounds in soil and groundwater are summarized on Table 6-2 through Table 6-4. 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

PFOA, PFOS, and PFBS in soil did not exceed the SLs in soil at AOI 4. 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 three intervals at boring location AOI04-01. The samples were collected 

from surface soil (0 to 2 feet bgs), shallow subsurface soil (8 to 10 feet bgs), and deep subsurface 

soil (18 to 20 feet bgs). PFOA, PFOS, and PFBS were detected at concentrations below the SLs. 

PFOA was detected in surface soil and shallow subsurface soil with concentrations of 0.54 J μg/kg 

and 0.179 J μg/kg, respectively. PFOA was not detected in the deeper subsurface soil. PFOS was

detected in surface soil and shallow subsurface soil, with concentrations of 64.2 μg/kg and 16.3 

μg/kg, respectively. PFOS was detected in deep subsurface soil, with a concentration of 16.1

μg/kg. PFBS was detected in surface soil and shallow subsurface soil, with concentrations of 

0.207J μg/kg and 0.468 J μg/kg, respectively. PFBS was detected in deep subsurface soil, with a 

concentration of 0.043 J μg/kg.

6.6.2 AOI 4 Groundwater Analytical Results

PFOA and PFOS in groundwater from temporary monitoring well location AOI04-01 exceeded 

SLs at AOI 4. Figure 6-4 presents the detections for PFOA, PFOS, and PFBS in groundwater. 

Table 6-5 summarizes the detected compounds in groundwater. 

Groundwater was sampled from temporary monitoring well location AOI04-01 at the Former

Storage Area. The SLs of 40 ng/L for PFOA and PFOS were exceeded at AOI04-01, with

concentrations of 622 ng/L and 62,700 ng/L, respectively. PFBS was detected at a concentration 

of 436 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 below their 

respective soil SLs. PFOA and PFOS detections in groundwater exceeded their respective 

individual SLs of 40 ng/L. PFBS was detected in groundwater at concentrations below the SL.
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 6-6

Based on the exceedances of the SLs for PFOA and PFOS in groundwater, further evaluation of 

AOI 4 is warranted. 

6.7 AOI 5

This section presents the analytical results for soil and groundwater in comparison to SLs for AOI 

5, which includes one potential PFAS release area: the Wash Rack. The detected compounds in 

soil and groundwater are summarized on Table 6-2 through Table 6-4. The detections of PFOA, 

PFOS, and PFBS in soil and groundwater are presented on Figure 6-1 through Figure 6-4.

6.7.1 AOI 5 Soil Analytical Results

PFOS in soil exceeded its SL in soil at AOI 5. 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 three intervals at boring locations AOI05-01 and AOI05-02. The samples 

were collected from surface soil (0 to 2 feet bgs), shallow subsurface soil (7 to 15 feet bgs), and 

deep subsurface soil (14 to 16 feet bgs). PFOA was detected in surface soil at both locations 

below the SL, with concentrations ranging from 6.24 μg/kg (AOI05-02 Duplicate) to 29.8 μg/kg

(AOI05-01). PFOS exceeded the SL of 130 μg/kg in surface soil, with concentrations ranging from 

137 μg/kg (AOI05-02 Duplicate) to 639 μg/kg (AOI05-01). PFBS was detected in surface soil 

below the SL, with concentrations ranging from non-detect to 0.045 J μg/kg. PFOA, PFOS, and 

PFBS did not exceed the SLs in shallow subsurface soil, and were detected at maximum 

concentrations of 17.4 μg/kg, 84.4 μg/kg, and 4.08 μg/kg, respectively, at location AOI05-01. 

PFOA, PFOS, and PFBS were detected in the deep subsurface, with concentrations of 0.278 J

μg/kg, 0.570 J μg/kg, and 0.096 J μg/kg at location AOI05-01, respectively. 

6.7.2 AOI 5 Groundwater Analytical Results

PFOA and PFOS in groundwater exceeded the SLs at AOI 5. 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 temporary monitoring well locations AOI05-01 and AOI05-02 at 

the Wash Rack. The SL of 40 ng/L for PFOA was exceeded at AOI05-01 and AOI05-02, with 

concentrations of 386 ng/L and 410 ng/L, respectively. The SL of 40 ng/L for PFOS was exceeded 

at AOI05-01 and AOI05-02, with concentrations of 1,210 ng/L and 329 ng/L, respectively. PFBS 

was detected below the SL of 600 ng/L at AOI05-01 and AOI05-02, with concentrations of 373 

ng/L and 46.6 J ng/L, respectively. The maximum PFOA and PFBS concentrations occurred at 

AOI05-01, which is adjacent to the Wash Rack.

6.7.3 AOI 5 Conclusions

Based on the results of the SI, PFOS was detected in soil at concentrations exceeding the SL. 

PFOA and PFOS were detected in groundwater at concentrations exceeding their respective 

individual SLs of 40 ng/L. PFBS was detected in groundwater and soil at concentrations below 

the SL. Based on the exceedances of the SLs for PFOS in soil and PFOA and PFOS in 

groundwater, further evaluation of AOI 5 is warranted. 

6.8 Sitewide

This section presents the analytical results for soil and groundwater in comparison to SLs for 

temporary monitoring wells installed sitewide across the Winder Barrow AASF to determine the 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 6-7

presence or absence of PFAS in environmental media upgradient (WB-01) and downgradient

(WB-02) from potential PFAS release areas. Location WB-01 serves to assess potential PFAS 

migration onto the facility from an off-facility source, but may be influenced by its proximity to the 

facility septic field and an open stormwater drainage line. Location WB-02 serves to assess 

potential PFAS migration off-facility from onsite potential release areas. The detected compounds 

in soil and groundwater are summarized on Table 6-2 through Table 6-4. The detections of PFOA, 

PFOS, and PFBS in soil and groundwater are presented on Figure 6-1 through Figure 6-4.

6.8.1 Sitewide Soil Analytical Results

PFOS, PFOA, and PFBS did not exceed the SLs in soil. 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 three intervals at boring locations, WB-01 and WB-02. The samples were 

collected from surface soil (0 to 2 feet bgs), shallow subsurface soil (9 to 12 feet bgs), and deep 

subsurface soil (18 to 22 feet bgs). PFOA, PFOS, and PFBS were detected in soil, at 

concentrations below the respective SLs. PFOA was detected in surface soil, with concentrations 

ranging from 0.102 J μg/kg to 0.189 J μg/kg. PFOA was detected in shallow subsurface soil, with 

concentrations ranging from non-detect to 0.208 J μg/kg. PFOA was not detected in deep 

subsurface soil. PFOS was detected in surface soil, with concentrations ranging from 0.745 J 

μg/kg to 1.16 J μg/kg. PFOS was detected in shallow subsurface soil, with concentrations ranging 

from 0.338 J μg/kg to 0.806 J μg/kg. PFOS was detected in deep subsurface soil, with 

concentrations ranging from 0.092 J μg/kg to 0.830 J μg/kg. PFBS was not detected in soil at 

either location. 

6.8.2 Sitewide Groundwater Analytical Results

PFOS in groundwater exceeded the SLs at both sitewide locations. 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 temporary monitoring well locations WB-01 and WB-02 to 

determine the presence or absence of PFAS at locations upgradient and downgradient of potential 

PFAS release areas. PFOA was detected below the SL of 40 ng/L at WB-01 and WB-02, with 

concentrations of 16.3 ng/L and 22.9 ng/L, respectively. The SL of 40 ng/L for PFOS was

exceeded at WB-01 and WB-02, with concentrations of 219 ng/L and 151 ng/L, respectively. PFBS 

was detected below the SL of 600 ng/L at WB-01 and WB-02, with concentrations of 3.10 J ng/L 

and 8.53 ng/L, respectively. The presence of PFOA, PFOS, and PFBS in groundwater at WB-01 

indicates the potential for PFAS to migrate onsite from an offsite source; however, groundwater 

at location WB-01 may be influenced by PFAS migration from the flight ramp via the open 

stormwater drainage line and the nearby septic field. The presence of PFOA, PFOS, and PFAS 

at WB-02 indicates that PFAS may potentially migrate offsite from the potential PFAS areas 

associated with AOI 1 through AOI 5. 

6.8.3 Sitewide Conclusions

Based on the results of the SI, PFOA, PFOS, and PFBS were detected in soil and groundwater. 

The detected concentrations of PFOA, PFOS, and PFBS in soil were several orders of magnitude 

lower than the soil SLs. PFOA, PFOS, and PFBS were detected in groundwater. PFOS was 

detected in groundwater at concentrations exceeding the SL of 40 ng/L, upgradient and 

downgradient of potential PFAS release areas. Although temporary well WB-01 is located at the 

upgradient facility boundary, it is in the downgradient direction of surface water flow from the flight 

ramp via an open stormwater drainage line that flows northeast along the facility boundary and is 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 6-8

adjacent to the facility septic field. It is possible that historical releases of PFAS to the flight ramp 

area or septic field may contribute to PFAS in soil and groundwater at location WB-01. Based on 

the exceedances of the SL for PFOS in groundwater, further evaluation at the facility is warranted. 
Table 6-2

PFAS Detections in Surface Soil

Site Inspection Report, Winder Barrow AASF, Georgia

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Q

8:2 FTS - ND ND ND ND ND ND ND ND ND 

NEtFOSAA - ND ND ND ND ND ND ND ND ND 

NMeFOSAA - ND ND ND ND ND ND ND ND ND 

PFBA - ND ND 0.055 J ND 0.188 J 0.088 J 0.080 J 0.215 J ND 

PFBS 1900 ND ND 0.034 J ND ND ND ND ND ND 

PFDA - ND ND ND ND 0.120 J ND ND ND ND 

PFDoA - ND ND ND ND 0.029 J ND ND ND ND 

PFHpA - ND ND 0.086 J ND 0.154 J 0.056 J 0.092 J 0.124 J ND 

PFHxA - ND ND 0.156 J 0.029 J 0.206 J 0.097 J 0.203 J 0.255 J 0.031 J PFHxS - ND ND 1.32 0.079 J 0.520 J 0.139 J 0.270 J ND 0.038 J 

PFNA - ND ND 0.023 J 0.240 J 0.622 J 0.104 J 0.056 J ND 0.026 J 

PFOA 130 ND ND 0.239 J ND 0.440 J 0.265 J 0.177 J ND 0.102 J 

PFOS 130 1.72 2.71 0.337 J 6.23 7.91 2.38 0.905 J ND 0.182 J 

PFPeA - ND ND 0.118 J 0.038 J 0.263 J 0.143 J 0.154 J 0.319 J 0.060 J PFTeDA - ND ND ND ND ND ND ND ND ND 

PFTrDA - ND ND ND ND 0.081 J ND ND ND ND 

PFUnDA - ND ND ND 0.055 J 0.377 J ND ND ND ND 

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

8:2 FTS 8:2 fluorotelomer sulfonateNEtFOSAA N-ethyl perfluorooctane- sulfonamidoacetic acidNMeFOSAA N-methyl perfluorooctanesulfonamidoacetic acid

References PFAS per- and polyfluoroalkyl substances

PFBA perfluorobutanoic acidPFBS perfluorobutanesulfonic acidPFDA perfluorodecanoic acidPFDoA perfluorododecanoic acidPFHpA perfluoroheptanoic acidPFHxA perfluorohexanoic acidPFHxS perfluorohexanesulfonic acid

Interpreted Qualifiers PFNA perfluorononanoic acidJ = Estimated concentration PFOA perfluorooctanoic acid

PFOS perfluorooctanesulfonic acidPFPeA perfluoropentanoic acidPFTeDA perfluorotetradecanoic acidPFTrDA perfluorotridecanoic acidPFUnDA perfluoro-n-undecanoic acidAcronyms and AbbreviationsA duplicateAASF Army Aviation Support FacilityAOI Area of Interestft feetHQ hazard quotientID identificationLCMSMS liquid chromatography with tandem mass spectromLOD 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

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFBS, PFOS, and PFOA in Groundwater or Soil using USEPA’s Regional Screening Level Calculator. HQ=0.1. 15 September 2021. Soil screening levels based on residential scenario for direct ingestion of contaminated soil.

AOI01 AOI02

Soil, PFAS by LCMSMS compliant with QSM 5.3 Table B-15 (μg/kg)

AOI02-05-SB-0-2

09/30/2021

0 - 2 ft

AOI02-06-SB

09/30/2021

0 - 2 ft

AOI02-03-SB-0-2

09/27/2021

0 - 2 ft

AOI02-04-SB-0-2

09/30/2021

0 - 2 ft

AOI02-01-SB-0-2

09/27/2021

0 - 2 ft

AOI02-02-SB-0-2

09/27/2021

0 - 2 ft

AOI01-01-SB-0-2-A

09/28/2021

0 - 2 ft

AOI01-02-SB-0-2

09/28/2021

0 - 2 ft

Area of Interest

Sample ID

Sample Date

Depth

AOI01-01-SB-0-2

09/28/2021

0 - 2 ft

AECOM 
Table 6-2

PFAS Detections in Surface Soil

Site Inspection Report, Winder Barrow AASF, Georgia

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual

8:2 FTS - 0.237 J ND ND ND 0.073 J 0.050 J ND ND

NEtFOSAA - ND ND ND 1.75 J 2.92 1.46 ND ND

NMeFOSAA - ND ND ND 1.59 J ND ND ND ND

PFBA - 0.059 J 0.107 J 0.124 J ND 0.326 J 0.309 J 0.065 J NDPFBS 1900 ND ND 0.207 J ND 0.045 J 0.042 J ND ND

PFDA - ND ND ND ND 0.259 J 0.209 J ND ND

PFDoA - 0.335 J ND ND ND 0.050 J 0.041 J ND NDPFHpA - 0.065 J 0.156 J 0.047 J 1.29 J 0.240 J 0.229 J 0.032 J 0.039 JPFHxA - 0.114 J 0.239 J 0.352 J 1.82 J 0.705 J 0.674 J 0.037 J 0.109 JPFHxS - 0.096 J 0.669 J 8.30 17.7 8.99 7.76 0.041 J 0.334 J

PFNA - 0.040 J 0.329 J 0.630 J 0.901 J 6.68 6.23 0.042 J 0.031 J

PFOA 130 0.186 J 0.587 J 0.540 J 29.8 7.27 6.24 0.102 J 0.189 JPFOS 130 0.773 J 5.09 64.2 639 162 137 0.745 J 1.16 J

PFPeA - 0.058 J 0.160 J 0.183 J 0.454 J 0.528 J 0.500 J 0.053 J 0.080 JPFTeDA - 0.152 J ND ND ND ND ND ND ND

PFTrDA - 1.50 ND ND ND 0.971 J 0.768 J ND ND

PFUnDA - 0.153 J 0.036 J ND ND 2.85 2.18 ND ND

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

8:2 FTS 8:2 fluorotelomer sulfonateNEtFOSAA N-ethyl perfluorooctane- sulfonamidoacetic acidNMeFOSAA N-methyl perfluorooctanesulfonamidoacetic acid

References PFAS per- and polyfluoroalkyl substances

PFBA perfluorobutanoic acidPFBS perfluorobutanesulfonic acidPFDA perfluorodecanoic acidPFDoA perfluorododecanoic acidPFHpA perfluoroheptanoic acidPFHxA perfluorohexanoic acidPFHxS perfluorohexanesulfonic acid

Interpreted Qualifiers PFNA perfluorononanoic acidJ = Estimated concentration PFOA perfluorooctanoic acid

PFOS perfluorooctanesulfonic acidPFPeA perfluoropentanoic acidPFTeDA perfluorotetradecanoic acidPFTrDA perfluorotridecanoic acidPFUnDA perfluoro-n-undecanoic acidAcronyms and AbbreviationsAASF Army Aviation Support FacilityAOI Area of Interestft feetHQ hazard quotientID identificationLCMSMS liquid chromatography with tandem mass spectromLOD 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 AgencyWB Winder Barrowμg/kg micrograms per kilogram- not applicable

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFBS, PFOS, and PFOA in Groundwater or Soil using USEPA’s Regional Screening Level Calculator. HQ=0.1. 15 September 2021. Soil screening levels based on residential scenario for direct ingestion of contaminated soil.

AOI05 Sitewide

WB-02-SB-0-2

09/28/2021

0 - 2 ft

Soil, PFAS by LCMSMS compliant with QSM 5.3 Table B-15 (μg/kg)

AOI05-02-SB-0-2-A

09/28/2021

0 - 2 ft

WB-01-SB-0-2

09/27/2021

0 - 2 ft

AOI05-01-SB-0-2

09/28/2021

0 - 2 ft

AOI05-02-SB-0-2

09/28/2021

0 - 2 ft

AOI03

AOI03-01-SB-0-2

09/28/2021

0 - 2 ft

AOI04

AOI04-01-SB-0-2

09/29/2021

0 - 2 ft

Area of Interest

Sample ID

Sample Date

Depth

AOI02

AOI02-08-SB-0-2

09/30/2021

0 - 2 ft

AECOM 
Table 6-3

PFAS Detections in Shallow Subsurface Soil

Site Inspection Report, Winder Barrow AASF, Georgia

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Resu

6:2 FTS - ND ND ND ND ND ND ND 0.101 J ND 

PFBA - ND ND ND ND ND ND ND 0.134 J 0.822 PFBS 25000 ND ND ND ND ND ND 0.026 J 0.468 J 4.08 PFHpA - ND ND ND ND ND ND 0.036 J 0.148 J 1.98 PFHxA - 0.059 J 0.064 J ND UJ 0.047 J 0.047 J ND 0.107 J 0.559 J 19.3 PFHxS - ND 0.084 J 0.051 J 0.068 J 0.053 J ND ND 5.39 97.6 

PFNA - ND ND ND UJ 0.028 J 0.032 J ND ND ND ND PFOA 1600 ND ND ND ND ND ND ND 0.179 J 17.4 

PFOS 1600 ND ND 0.671 J 0.810 J 0.737 J 0.163 J ND 16.3 84.4 

PFPeA - 0.027 J 0.039 J ND UJ 0.032 J 0.029 J ND 0.089 J 0.226 J 2.57 PFUnDA - ND ND ND ND ND ND ND ND ND 

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

6:2 FTS 6:2 fluorotelomer sulfonatePFAS per- and polyfluoroalkyl substancesPFBA perfluorobutanoic acid

References PFBS perfluorobutanesulfonic acid

PFHpA perfluoroheptanoic acidPFHxA perfluorohexanoic acidPFHxS perfluorohexanesulfonic acidPFNA perfluorononanoic acidPFOA perfluorooctanoic acidPFOS perfluorooctanesulfonic acidPFPeA perfluoropentanoic acid

Interpreted Qualifiers PFUnDA perfluoro-n-undecanoic acid

J = Estimated concentrationUJ = The analyte was not detected at a level greater than or equal to the adjusted DL. However, the reported adjusted DL is approximate and may be inaccurate or imprecise. Acronyms and Abbreviations

A duplicateAASF Army Aviation Support FacilityAOI Area of InterestDL detection limitft feetHQ hazard quotientID identificationLCMSMS liquid chromatography with tandem mLOD 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 Protectioμg/kg micrograms per kilogram- not applicable

Soil, PFAS by LCMSMS compliant with QSM 5.3 Table B-15 (μg/kg)

AOI04

AOI04-01-SB-8-10

09/29/2021

8 - 10 ft

AOI0

0

AOI02-03-SB-10-12

AOI03

AOI03-01-SB-10-12

09/28/2021

10 - 12 ft

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFBS, PFOS, and PFOA in Groundwater or Soil using USEPA’s Regional Screening Level Calculator. HQ=0.1. 15 September 2021. Soil screening levels based on industrial/commercial composite worker scenario for incidental ingestion of contaminated soil.

AOI02

9 - 11 ft

AOI02-01-SB-9-11-A

09/27/2021

9 - 11 ft

09/27/2021

10 - 12 ft

AOI02-02-SB-7-9

09/27/2021

7 - 9 ft

Area of Interest

Sample ID

Sample Date

Depth

AOI01-02-SB-8-10

09/28/2021

8 - 10 ft

AOI01-01-SB-9-11

09/28/2021

9 - 11 ft

AOI01

AOI02-01-SB-9-11

09/27/2021

AECOM 
Table 6-3

PFAS Detections in Shallow Subsurface Soil

Site Inspection Report, Winder Barrow AASF, Georgia

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual

6:2 FTS - ND ND NDPFBA - ND ND NDPFBS 25000 ND ND NDPFHpA - 0.036 J ND 0.045 JPFHxA - 0.090 J 0.044 J 0.083 JPFHxS - 0.271 J ND 0.715 JPFNA - ND ND 0.050 JPFOA 1600 0.130 J ND 0.208 JPFOS 1600 ND 0.338 J 0.806 J

PFPeA - 0.039 J ND 0.027 JPFUnDA - ND ND ND

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

6:2 FTS 6:2 fluorotelomer sulfonatePFAS per- and polyfluoroalkyl substancesPFBA perfluorobutanoic acid

References PFBS perfluorobutanesulfonic acid

PFHpA perfluoroheptanoic acidPFHxA perfluorohexanoic acidPFHxS perfluorohexanesulfonic acidPFNA perfluorononanoic acidPFOA perfluorooctanoic acidPFOS perfluorooctanesulfonic acidPFPeA perfluoropentanoic acid

Interpreted Qualifiers PFUnDA perfluoro-n-undecanoic acid

J = Estimated concentration

Acronyms and AbbreviationsA duplicateAASF Army Aviation Support FacilityAOI Area of Interestft feetHQ hazard quotientID identificationLCMSMS liquid chromatography with tandem mLOD 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 ProtectioWB Winder Barrowμg/kg micrograms per kilogram- not applicable

Area of Interest

Sample ID

Sample Date

Depth

AOI05

AOI05-02-SB-13-15

09/28/2021

Soil, PFAS by LCMSMS compliant with QSM 5.3 Table B-15 (μg/kg)

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFBS, PFOS, and PFOA in Groundwater or Soil using USEPA’s Regional Screening Level Calculator. HQ=0.1. 15 September 2021. Soil screening levels based on industrial/commercial composite worker scenario for incidental ingestion of contaminated soil.

WB-02-SB-9-11

09/28/2021

13 - 15 ft 9 - 11 ft

WB-01-SB-10-12

09/27/2021

10 - 12 ft

Sitewide

AECOM 
Table 6-4

PFAS Detections in Deep Subsurface Soil

Site Inspection Report, Winder Barrow AASF, Georgia

Area of Interest

Sample ID

Sample Date

Depth

Analyte Result Qual Result Qual 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)6:2 FTS ND 0.924 J 0.354 J ND ND ND ND ND 0.421 J PFBA ND 0.123 J ND 0.087 J ND ND ND ND ND 

PFBS 0.110 J 0.134 J ND ND ND ND ND 0.043 J 0.096 J PFHpA ND 0.230 J ND 0.232 J 0.064 J ND ND ND 0.081 J 

PFHxA 0.119 J 0.607 J 0.113 J 0.600 J 0.125 J 0.029 J ND UJ 0.183 J 0.253 J 

PFHxS 0.566 J 1.61 0.519 J 0.100 J 0.112 J 0.077 J 0.087 J 0.877 J 1.48 PFNA 0.087 J 0.281 J ND 0.379 J ND ND ND ND 0.040 J 

PFOA ND 0.512 J- ND 0.586 J ND ND ND ND 0.278 J 

PFOS 4.15 2.46 J 0.748 J 0.900 J ND ND ND 16.1 0.570 J 

PFPeA 0.042 J 0.384 J 0.053 J 0.303 J 0.116 J ND ND 0.058 J 0.100 J 

Interpreted Qualifiers Chemical AbbreviationsJ = Estimated concentration 6:2 FTS 6:2 fluorotelomer sulfonateJ- = Estimated concentration, biased low PFAS per- and polyfluoroalkyl sub

UJ = The analyte was not detected at a level greater than or equal to the adjusted DL. However, the reported adjusted DL is approximate and may be inaccurate or imprecise. PFBA perfluorobutanoic acid

PFBS perfluorobutanesulfonic acid

PFHpA perfluoroheptanoic acidPFHxA perfluorohexanoic acidPFHxS perfluorohexanesulfonic acPFNA perfluorononanoic acidPFOA perfluorooctanoic acidPFOS perfluorooctanesulfonic acidPFPeA perfluoropentanoic acidAcronyms and Abbreviations

A duplicateAASF Army Aviation Support FaciAOI Area of InterestDL detection limitft feetID identificationLCMSMS liquid chromatography with LOD limit of detectionND analyte not detected above QSM Quality Systems ManualQual interpreted qualifierSB soil boringWB Winder Barrowμg/kg micrograms per Kilogram

AOI01-01-SB-18-20

09/28/2021

AOI02-01-SB-18-20

09/27/2021

AOI02 AOI03 

AOI02-02-SB-16-18

09/27/2021

18 - 20 ft 16 - 18 ft 

AOI02-03-SB-19-21

09/27/2021

19 - 21 ft

AOI03-01-SB-20-22

09/28/2021

18 - 20 ft 20 - 22 ft

AOI01-02-SB-16-18

09/28/2021

16 - 18 ft

AOI05

AOI05-01-SB-14-16

09/28/2021

14 - 16 ft

AOI03-01-SB-20-22-A

09/28/2021

20 - 22 ft

AOI04

AOI04-01-SB-18-20

09/29/2021

18 - 20 ft

AOI01

AECOM 
Table 6-5

PFAS Detections in Groundwater

Site Inspection Report, Winder Barrow AASF, Georgia

Analyte OSD Screening 

Level a

USEPA HA b Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result 

6:2 FTS - - 300 2040 2030 717 J 2.72 J 85.4 3.80 J 4.44 

8:2 FTS - - 34.3 3.78 J 4.19 9.45 ND 31.5 ND ND 

PFBA - - 253 330 382 50.0 13.9 80.2 8.40 7.81 

PFBS 600 - 1220 417 464 42.5 3.95 J 35.7 21.0 20.1 

PFDA - - 3.13 J ND UJ 1.46 J ND ND ND ND ND 

PFHpA - - 238 667 787 50.5 10.9 154 15.5 14.3 

PFHxA - - 1620 2060 2250 247 J 26.5 291 70.8 66.5 

PFHxS - - 6500 4740 5150 1020 J 113 405 310 291 

PFNA - - 102 846 1020 32.4 55.9 54.0 ND ND 

PFOA 40 70 506 1540 1740 181 J+ 42.0 104 36.9 35.0 PFOS 40 70 7180 6580 7350 1210 J 1060 42.3 ND ND 

PFPeA - - 607 1100 1310 111 22.8 249 23.3 21.7 

PFUnDA - - ND ND ND ND ND ND ND ND 

Total PFOA+PFOS - 70 7690 8120 9090 1390 1100 146 36.9 35.0 

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical AbbreviationsBold Font Detected concentration exceeded USEPA HA Screening Levels 6:2 FTS 6:2 fluorotelomer sulfonate

8:2 FTS 8:2 fluorotelomer sulfonatePFAS per- and polyfluoroalkyl subst

References PFBA perfluorobutanoic acid

PFBS perfluorobutanesulfonic acidPFDA perfluorodecanoic acidPFHpA perfluoroheptanoic acidPFHxA perfluorohexanoic acidPFHxS perfluorohexanesulfonic acidPFNA perfluorononanoic acid

Interpreted Qualifiers PFOA perfluorooctanoic acid

J = Estimated concentration PFOS perfluorooctanesulfonic acid

J+ = Estimated concentration, biased high PFPeA perfluoropentanoic acidUJ = The analyte was not detected at a level greater than or equal to the adjusted DL. However, the reported adjusted DL is approximate and may be inaccurate or imprecise. PFUnDA perfluoro-n-undecanoic acid

Acronyms and Abbreviations

A duplicateAASF Army Aviation Support FacilitAOI Area of InterestDC District of ColumbiaDL detection limitEPA Environmental Protection AgeGW groundwaterHA Health AdvisoryHQ hazard quotientID identificationLCMSMS liquid chromatography with taLOD limit of detectionND analyte not detected above thOSD Office of the Secretary of DefQSM Quality Systems ManualQual interpreted qualifierUSEPA United States Environmental WB Winder Barrowng/l nanogram per liter

Area of Interest

Sample ID

Sample Date

AOI01-01-GW

09/29/2021 09/28/2021

AOI02-02-GW

09/28/2021

AOI01-02-GW

09/28/2021

AOI01-02-GW-A

09/28/2021

Water, PFAS by LCMSMS compliant with QSM 5.3 Table B-15 (ng/l)

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFBS, PFOS, and PFOA in Groundwater or Soil using USEPA’s Regional Screening Level Calculator. HQ=0.1. 15 September 2021. Groundwater screening levels based on residential scenario for direct ingestion of groundwater.b. USEPA, 2016. Drinking Water Health Advisory for PFOA. Office of Water (4304T). Health and Ecological Criteria Division, Washington, DC 20460. EPA Document Number: 822-R-16-005. May 2016. / EPA. 2016. Drinking Water Health Advisory for PFOS. Office of Water (4304T). Health and Ecological Criteria Division, Washington, DC 20460. EPA Document Number: 822-R-16-004. May 2016.

AOI01 AOI02 AOI03

AOI03-01

09/29/

AOI02-03-GW

09/28/2021

AOI03-01-GW

09/29/2021

AOI02-01-GW

AECOM 
Table 6-5

PFAS Detections in Groundwater

Site Inspection Report, Winder Barrow AASF

Analyte OSD Screening 

Level a

USEPA HA b Result Qual Result Qual Result Qual Result Qual

6:2 FTS - - 1860 42.2 ND 11.4

8:2 FTS - - 40.5 ND ND 2.79 JPFBA - - 158 43.7 5.30 10.1

PFBS 600 - 373 46.6 3.10 J 8.53PFDA - - ND ND ND ND

PFHpA - - 389 107 3.91 11.1PFHxA - - 1070 253 17.6 36.0PFHxS - - 3040 824 46.5 94.7PFNA - - 175 93.5 3.61 J 4.07PFOA 40 70 386 410 16.3 22.9PFOS 40 70 1210 329 219 151PFPeA - - 569 110 6.53 21.1PFUnDA - - ND 2.20 J ND 3.45 J

Total PFOA+PFOS - 70 1600 739 235 174

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical AbbreviationsBold Font Detected concentration exceeded USEPA HA Screening Levels 6:2 FTS 6:2 fluorotelomer sulfonate

8:2 FTS 8:2 fluorotelomer sulfonatePFAS per- and polyfluoroalkyl subst

References PFBA perfluorobutanoic acid

PFBS perfluorobutanesulfonic acidPFDA perfluorodecanoic acidPFHpA perfluoroheptanoic acidPFHxA perfluorohexanoic acidPFHxS perfluorohexanesulfonic acidPFNA perfluorononanoic acid

Interpreted Qualifiers PFOA perfluorooctanoic acid

J = Estimated concentration PFOS perfluorooctanesulfonic acid

J+ = Estimated concentration, biased high PFPeA perfluoropentanoic acidUJ = The analyte was not detected at a level greater than or equal to the adjusted DL. However, the reported adjusted DL is approximate and may be inaccurate or imprecise. PFUnDA perfluoro-n-undecanoic acid

Acronyms and Abbreviations

A duplicateAASF Army Aviation Support FacilitAOI Area of InterestDC District of ColumbiaDL detection limitEPA Environmental Protection AgeGW groundwaterHA Health AdvisoryHQ hazard quotientID identificationLCMSMS liquid chromatography with taLOD limit of detectionND analyte not detected above thOSD Office of the Secretary of DefQSM Quality Systems ManualQual interpreted qualifierUSEPA United States Environmental ng/l nanogram per liter- not applicable

b. USEPA, 2016. Drinking Water Health Advisory for PFOA. Office of Water (4304T). Health and Ecological Criteria Division, Washington, DC 20460. EPA Document Number: 822-R-16-005. May 2016. / EPA. 2016. Drinking Water Health Advisory for PFOS. Office of Water (4304T). Health and Ecological Criteria Division, Washington, DC 20460. EPA Document Number: 822-R-16-004. May 2016.

AOI05 Sitewide

WB-02-GW

09/29/2021

Water, PFAS by LCMSMS compliant with QSM 5.3 Table B-15 (ng/l)

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFBS, PFOS, and PFOA in Groundwater or Soil using USEPA’s Regional Screening Level Calculator. HQ=0.1. 15 September 2021. Groundwater screening levels based on residential scenario for direct ingestion of groundwater.

AOI05-02-GW

09/29/2021

WB-01-GW

09/28/2021

Area of Interest

Sample ID

Sample Date

AOI05-01-GW

09/29/2021

AECOM 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

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PFOA Detections in Soil

12420 Milestone Center Drive

Germantown, MD 20876

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PFOS Detections in Soil

12420 Milestone Center Drive

Germantown, MD 20876

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C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\GA\WinderBarrow_Figures\SI_Figures\SI_Report\Results\Fig_6-3_WinderBarrow_SI_Soil_PFBS_Results.mxd

PFBS Detections in Soil

12420 Milestone Center Drive

Germantown, MD 20876

Legend

Facility Boundary

River/Stream

Shallow Intermediate Deep

AECOM 6-19
AOI01-01

AOI01-02

AOI02-01

AOI02-02

AOI03-01 AOI04-01

AOI05-01

AOI05-02

WB-01

WB-02

AOI02-03

AOI01-01

AOI01-02

AOI02-01

AOI02-02

AOI03-01 AOI04-01

AOI05-01

WB-01

WB-02

AOI02-03

AOI05-02

PFOA Results (ng/L)

ND

>ND - 10

>10 - 40

>40 - 70

>70 - 400

>400

AOI01-01

AOI01-02

AOI02-01

AOI02-02

AOI03-01 AOI04-01

AOI05-01

AOI05-02

WB-01

WB-02

AOI02-03

­ Figure 6-4

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection for PFAS at Winder Barrow AASF, GA

2/3/2022

2/3/2022

2/3/2022

MS

JW

CM

GIS BY

CHK BY

PM

Base Map: Source: Esri, Maxar, GeoEye, Earthstar Geographics, CNES/Airbus DS,

USDA, USGS, AeroGRID, IGN, and the GIS User Community

2/3/2022

1:4,200

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\GA\WinderBarrow_Figures\SI_Figures\SI_Report\Results\Fig_6-4_WinderBarrow_SI_GW_Results.mxd

Legend

Facility Boundary

Groundwater Flow Direction

PFOA, PFOS, and PFBS Detections in Groundwater 

12420 Milestone Center Drive

Germantown, MD 20876

PFOS Results (ng/L)

ND

>ND - 10

>10 - 40

>40 - 70

>70 - 400

>400

PFBS Results (ng/L)

ND

>ND - 100

>100 - 600

>600 - 1,000

>1,000 - 6,000

>6,000

0 175 350 700

Feet

PFOA PFOS PFBS

AECOM 6-20
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 7-1

7. Exposure Pathways

The CSMs for each AOI, revised based on the SI findings, are presented on Figure 7-1 through 

Figure 7-3. A CSM presents the current understanding of the site conditions with respect to known 

and suspected 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 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, 

trespassers (though unlikely due to restricted access), 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 the AOIs based on the 

aforementioned criteria.

7.1.1 AOI 1

During a one-time training event performed by the City of Atlanta Fire Department, AFFF may 

have been released to paved and/or bare surfaces depending on the time of the event at AOI 1. 

PFOA, PFOS, and PFBS were detected in soil at AOI 1 and confirm the release of PFAS to soil.

Based on the results of the SI at AOI 1, ground-disturbing activities could potentially result in site 

worker, future construction worker, or trespasser exposure to PFOA, PFOS, and PFBS via 

inhalation of dust or ingestion of surface soil. Ground-disturbing activities could potentially result 

in future construction worker exposure to PFOA, PFOS, and PFBS via ingestion of subsurface 

soil. No current construction activities are occurring at AOI 1. The CSM for AOI 1 is presented on 

Figure 7-1. 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 7-2

7.1.2 AOI 2

During an elementary school field trip demonstration, AFFF was unintentionally released from a

facility crash rescue firetruck to the ramp directly southeast of Hangar 2. The AFFF may have 

been released to paved and unpaved surfaces. In addition, Tri-MaxTM fire extinguishers have been 

staged on the flight ramp historically; however, the exact timeframe and locations of the Tri-MaxTM

fire extinguishers on the flight ramp are uncertain. It is presumed that the units were stationed on 

the east side of the main ramp, between aircraft parking positions. PFOA and PFOS were 

detected in soil at AOI 2 at the East Ramp AFFF Release Area and the potential historical TriMaxTM fire extinguisher staging areas and confirm the release of PFAS to soil at AOI 2. 

Based on the results of the SI at AOI 2, ground-disturbing activities could potentially result in site 

worker, future construction worker, or trespasser exposure to PFOA and PFOS via inhalation of 

dust or ingestion of surface soil. Ground-disturbing activities could potentially result in future 

construction worker exposure to PFOS via ingestion of subsurface soil. No current construction 

activities are occurring at AOI 2. The CSM for AOI 2 is presented on Figure 7-1. 

7.1.3 AOI 3

Potential releases of AFFF may have occurred at AOI 3 as a result of the storage of twelve 30-

gallon Tri-MaxTM fire extinguishers in a storage cage. The fire extinguishers are currently staged 

at AOI 4 pending transport to an off-site repair facility. If AFFF were released in the AOI 3 storage 

cage area, releases would have occurred to paved surfaces. PFOA, PFOS, and PFBS were 

detected in soil at the nearest downgradient unpaved area from the Tri-MaxTM fire extinguisher 

storage cage, indicating that a release of PFAS to soil at AOI 3 occurred.

Based on the results of the SI at AOI 3, ground-disturbing activities could potentially result in site 

worker, future construction worker, or trespasser exposure to PFOA and PFOS via inhalation of 

dust or ingestion of surface soil. Ground-disturbing activities could potentially result in future 

construction worker exposure to PFBS via ingestion of subsurface soil. No current construction is 

occurring at AOI 3. The CSM for AOI 3 is presented on Figure 7-2.

7.1.4 AOI 4

Potential releases of AFFF may have occurred at AOI 4 as a result of storing the former facility 

crash rescue firetruck in a garage until approximately 2004. The crash rescue firetruck may have 

been used to store AFFF in 5-gallon buckets. Bulk AFFF was also stored in the garage prior to

2004. Additionally, Tri-MaxTM fire extinguishers awaiting offsite transport and disposal are currently 

staged on the southeast side of the garage. The garage has no floor drains, but a bay door opens 

on the west end of the garage to a gravel driveway. PFOA, PFOS, and PFBS were detected in 

soil at AOI 4, with the PFOS concentrations detected orders of magnitude higher than PFOA or 

PFBS, and confirm the release of PFAS to soil. 

Based on the results of the SI at AOI 4, ground-disturbing activities could potentially result in site 

worker, future construction worker, or trespasser exposure to PFOA, PFOS, and PFBS via 

inhalation of dust or ingestion of surface soil. Ground-disturbing activities could potentially result 

in future construction worker exposure to PFOA, PFOS, and PFBS via ingestion of subsurface 

soil. No current construction is occurring at AOI 4. The CSM for AOI 4 is presented on Figure 7-

1.

7.1.5 AOI 5

AFFF may have been released to the Wash Rack at AOI 5 as a result of washing the former crash 

rescue firetruck. Additionally, 5-gallon buckets have been stored in a flammable container 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 7-3

adjacent to the Wash Rack and could have caused accidental releases of AFFF to paved 

surfaces, soil and the Wash Rack recirculatory system. PFOA, PFOS, and PFBS were detected 

in soil, and PFOS was detected above its SL, and confirm the release of PFAS to soil at AOI 5.

Based on the results of the SI at AOI 5, ground-disturbing activities could potentially result in site 

worker, future construction worker, or trespasser exposure to PFOA, PFOS, and PFBS via 

inhalation of dust or ingestion of surface soil. Ground-disturbing activities could potentially result 

in future construction worker exposure to PFOA, PFOS, and PFBS via ingestion of subsurface 

soil. No current construction is occurring at AOI 5. The CSM for AOI 5 is presented on Figure 7-

3.

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 the AOIs based 

on the aforementioned criteria. Winder Barrow AASF receives its potable water from the City of 

Winder Water Works; therefore, the ingestion exposure pathway for site workers and trespassers 

is considered incomplete. According to online resources, there are multiple residences 

downgradient from the AASF that use private well water. Therefore, the ingestion exposure 

pathway for off-facility residents is considered potentially complete. 

7.2.1 AOI 1

PFOA and PFOS in groundwater exceeded the SLs at both temporary monitoring well locations

(AOI01-01and AOI01-02), and PFBS exceeded the SL at one temporary monitoring well location 

(AOI01-01) at AOI 1. Depths to water at AOI 1 measured in September 2021 during the SI ranged 

from 13.96 to 22.5 feet bgs. Therefore, groundwater may be encountered during construction 

activities, and the ingestion exposure pathway for future construction workers is considered 

potentially complete. Because well water is listed as the water source for multiple downgradient 

residences, the exposure pathway for off-facility resident is also potentially complete. The CSM 

for AOI 1 is presented on Figure 7-1. 

7.2.2 AOI 2

PFOA and PFOS in groundwater exceeded the SLs at all three temporary monitoring well 

locations (AOI02-01, AOI02-02, and AOI02-03) at AOI 2. PFBS was detected in groundwater at 

all three temporary monitoring wells at concentrations below the SL. Depths to water at AOI 2 

measured in September 2021 during the SI ranged from 10.48 to 12.53 feet bgs. Therefore, 

groundwater may be encountered during construction activities, and the ingestion exposure 

pathway for future construction workers is considered potentially complete. Because well water 

is listed as the water source for multiple downgradient residences, the exposure pathway for offfacility resident is also potentially complete. The CSM for AOI 2 is presented on Figure 7-1.

7.2.3 AOI 3

PFOA and PFBS in groundwater were detected below SLs at the one temporary monitoring well 

location (AOI03-01) at AOI 3. PFOS was not detected in groundwater at AOI 3. Depth to water in

AOI 3 measured in September 2021 during the SI was 14.79 feet bgs. Therefore, groundwater 

may be encountered during construction activities, and the ingestion exposure pathway for future 

construction workers is considered potentially complete. The CSM for AOI 3 is presented on 

Figure 7-2.
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 7-4

7.2.4 AOI 4

PFOA and PFOS in groundwater were detected above SLs at the one temporary monitoring well 

location (AOI04-01) at AOI 4. PFBS was detected in groundwater below the SL. Depth to water 

at AOI 4 measured in September 2021 during the SI was 12.33 feet bgs. Therefore, groundwater 

may be encountered during construction activities, and the ingestion exposure pathway for future 

construction workers is considered potentially complete. The exposure pathway for off-facility 

resident is also potentially complete based on the presence of private wells in the downgradient 

direction. The CSM for AOI 4 is presented on Figure 7-1.

7.2.5 AOI 5

PFOA and PFOS in groundwater were detected above SLs at both temporary monitoring well 

locations (AOI05-01 and AOI05-02) at AOI 5. PFBS was detected in groundwater below the SL. 

Depths to water at AOI 5 measured in September 2021 during the SI ranged from 12.07 to 12.15

feet bgs. Therefore, groundwater may be encountered during construction activities, and the 

ingestion exposure pathway for future construction workers is considered potentially complete. 

The exposure pathway for off-facility resident is also potentially complete based on the presence 

of private wells in the downgradient direction. The CSM for AOI 5 is presented on Figure 7-3.

7.3 Surface Water and 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.

7.3.1 AOI 1

PFAS are water soluble and can migrate readily from soil to groundwater and surface water via 

leaching and run-off. Surface water runoff at AOI 1 flows to the north towards the drainage canal. 

Because PFOA, PFOS, and PFBS were detected in soil and were detected above SLs in 

groundwater, it is possible that those compounds may have migrated from soil and groundwater 

to the north, towards the drainage canal on the northern edge of the property via groundwater 

discharge or surface water runoff. Therefore, the surface water and sediment ingestion exposure 

pathway for site workers, future construction workers, or trespassers is considered potentially 

complete. 

The drainage canal on the northern edge of the property flows off facility to Lower Twin Lake to 

the northwest, which is used for recreational activities. Due to potential recreational use of Lower 

Twin Lake, the surface water and sediment ingestion exposure pathway for off-facility recreational 

users is considered potentially complete. The CSM for AOI 1 is presented on Figure 7-1.

7.3.2 AOI 2

Surface water runoff at AOI 2 flows east across the facility septic field and is conveyed around the 

septic field via a stormwater drainage ditch that connects to the drainage canal along the northeast 

boundary of the facility. Additionally, groundwater flows northwest towards the drainage canal on 

the northern edge of the property. Because PFOA and PFOS were detected in soil and PFOA and 

PFOS were detected above SLs in groundwater, it is possible that those compounds may have 

migrated from soil and groundwater to the septic field stormwater drainage ditch and the drainage 

canal on the northern edge of the property via groundwater discharge or stormwater runoff. 

Therefore, the surface water and sediment ingestion exposure pathway for site workers, future 

construction workers, or trespassers is considered potentially complete. 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 7-5

Because the drainage canal on the northern edge of the property flows to Lower Twin Lake, which 

is used for recreational activities, the surface water and sediment ingestion exposure pathway for 

off-facility recreational users is also considered potentially complete. The CSM for AOI 2 is 

presented on Figure 7-1.

7.3.3 AOI 3

Surface water runoff at AOI 3 flows to the drainage canal on the northwest border of the AASF. 

Additionally, groundwater flows northwest towards the drainage canal on the northern edge of the 

property. Because PFOA, PFOS, and PFBS were detected in soil and PFOA and PFBS were 

detected in groundwater, it is possible that those compounds may have migrated from soil and 

groundwater to the drainage canal on the northern edge of the property via groundwater discharge 

or stormwater runoff. Therefore, the surface water and sediment ingestion exposure pathway for 

site workers, future construction workers, or trespassers is considered potentially complete. 

Because the drainage canal on the northern edge of the property flows to Lower Twin Lake, which 

is used for recreational activities, the surface water and sediment ingestion exposure pathway for 

off-facility recreational users is also considered potentially complete. The CSM for AOI 3 is 

presented on Figure 7-2.

7.3.4 AOI 4

Surface water runoff at AOI 4 flows to the drainage canal on the northwest border of the AASF

and groundwater at the AOI flows northwest towards the drainage canal on the northern edge of 

the property. Because PFOA, PFOS, and PFBS were detected in soil and PFOA and PFOS were 

detected above SLs in groundwater, it is possible that those compounds may have migrated from 

soil and groundwater to the north towards the drainage canal on the northern edge of the property

via groundwater discharge and surface water runoff. Therefore, the surface water and sediment 

ingestion exposure pathway for site workers, future construction workers, or trespassers is 

considered potentially complete

Because the drainage canal on the northern edge of the property flows to Lower Twin Lake, which 

is used for recreational activities, the surface water and sediment ingestion exposure pathway for 

off-facility recreational users is also considered potentially complete. The CSM for AOI 4 is 

presented on Figure 7-1.

7.3.5 AOI 5

No wastewater from the Wash Rack is discharged to the environment; however, when the Wash 

Rack is not in use, stormwater runoff is conveyed to a drainage ditch north of the Wash Rack via 

an underground pipe. The ditch connects to the drainage canal on the northwest border of the 

AASF and flows off-facility. In addition, groundwater at the AOI flows northwest towards the 

drainage canal on the northern edge of the property. Because PFOA, PFOS, and PFBS were 

detected in soil and groundwater, with PFOS concentrations exceeding the SL in soil and PFOA 

and PFOS concentrations exceeding the SLs in groundwater, it is possible that those compounds 

may have migrated from soil and groundwater to the north towards the drainage canal on the 

northern edge of the property via groundwater discharge and surface water runoff. Therefore, the 

surface water and sediment ingestion exposure pathway for site workers, future construction 

workers, or trespassers is considered potentially complete

Because the drainage canal on the northern edge of the property flows to Lower Twin Lake, which 

is used for recreational activities, the surface water and sediment ingestion exposure pathway for 

off-facility recreational users is also considered potentially complete. The CSM for AOI 5 is 

presented on Figure 7-3.
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 7-6

THIS PAGE INTENTIONALLY BLANK
SOURCE PATHWAY RECEPTOR

AOI 1

AOI 2

AOI 4

AFF Fire Training 

Event and Bulk 

AFFF, Tri-MaxTM

Fire Extinguisher, 

and Firetruck 

Storage

Human 

Activities

Precipitation/ 

Run-Off

Leaching/ 

Infiltration

Airborne Soil 

particulate

Surface Soil 

Surface 

Water/ 

sediment

Subsurface 

Soil

Shallow 

Groundwater

Source Release 

Mechanism Media Transport and Migration Media Exposure Routes

Inhalation of 

Dust

Ingestion

Ingestion

Ingestion

Ingestion

Human Receptors: 

Current/ Future

Flow-Chart Continues

Partial / Possible Flow

Flow-Chart Stops

Incomplete Pathway

Potentially Complete Pathway

Potentially Complete Pathway 

with Exceedance of SL

/ / / /

/ / / /

LEGEND

/ / / /

/ / /

/ / / /

Figure 7-1

Conceptual Site Model, AOI 1, AOI 2, and AOI 4

Winder Barrow AASF

Potential 

Off-Facility 

Source Not 

under 

Control of 

ARNG

PFAS in 

Surface Soil

Surface 

Water Flow

NOTES

1. The resident and recreational users

refer to off-site receptors.

2. Dermal contact exposure pathway is

incomplete for PFAS.

3. Human consumption of fish

potentially affected by PFAS is possible.

Site Worker Construction Worker Resident1,2 Recreational User/ Trespasser1,2,3

Site Worker Construction Worker Resident1,2 Recreational User/ Trespasser1,2,3

/

7-7
SOURCE PATHWAY RECEPTOR

AOI 3 Tri-MaxTM Fire 

Extinguisher 

Storage

Human 

Activities

Precipitation/ 

Run-Off

Leaching/ 

Infiltration

Airborne Soil 

particulate

Surface Soil 

Surface 

Water/ 

sediment

Subsurface 

Soil

Shallow 

Groundwater

Source Release 

Mechanism Media Transport and Migration Media Exposure Routes

Inhalation of 

Dust

Ingestion

Ingestion

Ingestion

Ingestion

Human Receptors: 

Current/ Future

Flow-Chart Continues

Partial / Possible Flow

Flow-Chart Stops

Incomplete Pathway

Potentially Complete Pathway

Potentially Complete Pathway 

with Exceedance of SL

/ / / /

/ / / /

LEGEND

/ / / /

/ / /

/ / / /

Figure 7-2

Conceptual Site Model, AOI 3

Winder Barrow AASF

Potential 

Off-Facility 

Source Not 

under 

Control of 

ARNG

PFAS in 

Surface Soil

Surface 

Water Flow

NOTES

1. The resident and recreational users

refer to off-site receptors.

2. Dermal contact exposure is

incomplete for PFAS.

3. Human consumption of fish

potentially affected by PFAS is possible.

Site Worker Construction Worker Resident1,2 Recreational User/ Trespasser1,2,3

Site Worker Construction Worker Resident1,2 Recreational User/ Trespasser1,2,3

/

7-8
SOURCE PATHWAY RECEPTOR

AOI 5 Wash Rack –

AFFF Rinsing

Human 

Activities

Precipitation/ 

Run-Off

Leaching/ 

Infiltration

Airborne Soil 

particulate

Surface Soil 

Surface 

Water/ 

sediment

Subsurface 

Soil

Shallow 

Groundwater

Source Release 

Mechanism Media Transport and Migration Media Exposure Routes

Inhalation of 

Dust

Ingestion

Ingestion

Ingestion

Ingestion

Human Receptors: 

Current/ Future

Flow-Chart Continues

Partial / Possible Flow

Flow-Chart Stops

Incomplete Pathway

Potentially Complete Pathway

Potentially Complete Pathway 

with Exceedance of SL

/ / / /

/ / / /

LEGEND

/ / / /

/ / /

/ / / /

Figure 7-3

Conceptual Site Model, AOI 5

Winder Barrow AASF

Potential 

Off-Facility 

Source Not 

under 

Control of 

ARNG

PFAS in 

Surface Soil

Surface 

Water Flow

NOTES

1. The resident and recreational users

refer to off-site receptors.

2. Dermal contact exposure pathway is

incomplete for PFAS.

3. Human consumption of fish

potentially affected by PFAS is possible.

Site Worker Construction Worker Resident1,2 Recreational User/ Trespasser1,2,3

Site Worker Construction Worker Resident1,2 Recreational User/ Trespasser1,2,3

/

7-9
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 7-10

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Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

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 16 July 2021, and from 27 to 30 September 2021 and 

consisted of decontamination water source sampling, utility clearance, direct push boring, soil 

sample collection, temporary monitoring well installation, grab groundwater sample collection, 

and land surveying. Field activities were conducted in accordance with the SI QAPP Addendum 

(AECOM, 2021a).

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.

• 38 soil samples from 11 boring locations;

• 11 grab groundwater samples from 11 temporary well locations; and

• 17 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, 

PFOS, and PFBS were detected both at the source areas, as well as at the upgradient 

and downgradient facility boundary areas. PFOA and PFOS in groundwater at AOI 1: 

North Ramp FTA, AOI 2: East Ramp AFFF Release Area and Tri-MaxTM Staging Area, AOI 

4: Former Storage Area, AOI 5: Wash Rack exceeded the SL of 40 ng/L (individually). 

PFOS in groundwater at the upgradient and downgradient facility boundary areas (WB-01 

amd WB-02) also exceeded the SL of 40 ng/L. PFBS in groundwater at AOI 1: North Ramp 

FTA exceeded the SL of 600 ng/L. The detected concentrations of PFOA and PFBS in soil 

samples from all AOIs were below the SLs. PFOS in soil at AOI 5: Wash Rack exceeded 

the SL of 130 μg/kg.

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 

groundwater and soil data collected during this SI: Former Tri-MaxTM Storage Area at AOI 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 8-2

3. PFOA, PFOS, and PFBS were not detected in groundwater and/ or soil above the SLs 

in this area.

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 this SI, there is a potentially complete pathway 

between the potential PFAS release areas and downgradient drinking water receptors due 

to the presence of private wells in the downgradient direction.

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

of a RI (if determined necessary).

All of the borings completed as a part of this SI were drilled to depths between 19 and 25 

feet bgs. The geological data collected from the boreholes indicate that the dominant 

lithology of the unconsolidated material underlying the Winder Barrow AASF is comprised 

of fine- to medium-grained, poorly to well-graded sand. Boring logs showed varying 

percentages of fines (silt and clay, specifically kaolinite), gravel, and weathered rock. The 

soils observed at the facility have a relatively high hydraulic conductivity, with well-graded 

sands and sand with gravel having the highest conductivity. Weathered bedrock observed 

at boring location AOI02-02 likely has a lower hydraulic conductivity and represents the 

most impermeable material. These site observations are consistent with the expected 

subsurface material conditions.

Depth to water at the facility ranges from approximately 9.58 to 16.29 feet bgs. 

Groundwater flow direction is to the northwest towards the drainage canal on the northern 

edge of the property, which drains to Lower Twin Lake. 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 groundwater and soil 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. Although the evaluation of groundwater and soil results at 

the upgradient facility boundary area (WB-01) indicate that an off-facility source is 

contributing to PFOA, PFOS, and PFBS detections onsite, the groundwater and soil 

results at WB-01 may be influenced by PFAS migration via the adjacent open stormwater 

drainage line and septic field. The pathway for PFAS migration onsite from off-facility 

sources in the upgradient direction requires further evaluation.

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 

upgradient and downgradient facility boundary areas indicate there is a potentially 

complete pathway between source and receptor.

8.3 Outcome 

Based on the CSMs developed and revised in light of the SI findings, there is potential for 

exposure to off-facility drinking water receptors from sources on facility resulting from historical 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 8-3

DoD activities based on the presence of private wells in the downgradient direction. The exposure 

pathway for on-facility drinking water receptors is considered incomplete because there are no 

potable wells at the facility and drinking water is supplied by the City of Winder Water Works. 

There is potential for exposure to onsite workers, future construction workers and trespassers via 

inhalation of dust, ingestion of surface soil, and ingestion of surface water and/or sediment. There 

is potential for exposure to future construction workers via ingestion of subsurface soil and shallow 

groundwater. Additionally, there is potential for exposure to off-facility recreational users via 

ingestion of surface water and/ or sediment. 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, PFOA, PFOS, and PFBS in groundwater exceeded their respective individual SLs 

at temporary well locations (AOI01-01 and AOI01-02), with maximum with concentrations 

of 1,740 ng/L (AOI01-02), 7,350 ng/L (AOI01-02) and 1,220 ng/L (AOI01-01), respectively.

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 exceeded their respective individual SLs at all 

temporary well locations (AOI02-01 through AOI02-03), with maximum concentrations of 

181 J+ ng/L (AOI02-01) and 1,210 J ng/L (AOI02-01), respectively. Based on the results of 

the SI, further evaluation of AOI 2 is warranted in the RI.

• At AOI 3, detected concentrations of PFOA, PFOS, and PFBS in groundwater were below 

SLs. 

• At AOI 4, PFOA and PFOS in groundwater exceeded their respective individual SLs at 

location AOI04-01, with concentrations of 622 ng/L and 62,700 ng/L, respectively. Based on 

the results of the SI, further evaluation of AOI 4 is warranted in the RI.

• At AOI 5, PFOA and PFOS in groundwater exceeded their respective individual SLs at both 

temporary well locations (AOI05-01 and AOI05-02), with maximum concentrations of 410 

ng/L (AOI05-02) and 1,210 ng/L (AOI05-02), respectively. Based on the results of the SI, 

further evaluation of AOI 5 is warranted in the RI.

• At WB-01 and WB-02, PFOS in groundwater exceeded its SL with concentrations of 219

ng/L and 151 ng/L, respectively. Based on the results of the SI, further evaluation of the 

facility upgradient and downgradient areas is warranted in the RI.

• The detected concentrations of PFOS in surface soil at AOI 5 exceeded the SL at both 

locations (AOI05-01 and AOI05-02), with a maximum concentration of 639 μg/kg at AOI05-

01.

• The detected concentrations of PFOA, PFOS, and PFBS in soil at AOI 1 through AOI 4 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 onsite workers, future 

construction workers, and trespassers via inhalation of dust, ingestion of surface soil, and 

ingestion of surface water and/or sediment; potential for exposure to future construction workers 

via ingestion of subsurface soil and shallow groundwater; potential for exposure to off-facility 

recreational users via ingestion of surface water and/or sediment; and potential for exposure to 

off-facility residents via ingestion of shallow groundwater 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 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 8-4

is warranted in the RI for AOI 1: North Ramp FTA, AOI 2: East Ramp AFFF Release Area and TriMaxTM Staging Area, AOI 4: Former Storage Area, and AOI 5: Wash Rack.
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

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 North Ramp FTA

2

East Ramp AFFF 

Release Area

Tri-MaxTM Staging 

Area

3 Former Tri-MaxTM 

Storage

4 Former Storage 

Area

5 Wash Rack

Sitewide Location – 

Upgradient 

Unknown N/A

Sitewide Location – 

Downgradient 

Potential Facility 

Releases N/A

Legend:

N/A = Not applicable 

= detected; exceedance of the screening levels

= detected; no exceedance of the screening levels

= not detected
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 8-6

Table 8-2: Site Inspection Recommendations

AOI Description Rationale Future Action

1 

North Ramp FTA Exceedances of SLs in groundwater at 

source area and in the downgradient 

direction. No exceedances of SLs in soil. 

Proceed to RI 

2 

East Ramp AFFF 

Release

Exceedances of SLs in groundwater at 

source area and in the downgradient 

direction. No exceedances of SLs in soil. 

Proceed to RI 

Tri-MaxTM Staging 

Area

Exceedances of SLs in groundwater at 

source area. No exceedances of SLs in 

soil. 

Proceed to RI 

3 

Former Tri-MaxTM

Storage

Detections in groundwater but no 

exceedances of SLs. No exceedances of 

SLs in soil.

No further action

4 

Current Tri-MaxTM

Storage

Exceedances of SLs in groundwater at 

source area. No exceedances of SLs in 

soil. 

Proceed to RI 

5 

Wash Rack Exceedances of SLs in groundwater at 

source area and in the downgradient 

direction. Exceedances of SLs in soil at the 

source area and in the downgradient 

direction. 

Proceed to RI 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 9-1

9. References

AECOM. 2018a. Final Site Inspection Programmatic Uniform Federal Policy-Quality Assurance 

Project Plan, Perfluorooctane Sulfonic Acid (PFOS) and Perfluorooctanoic Acid (PFOA) 

Impacted Sites ARNG Installations, Nationwide Contract No. W912DR-12-D-0014/

W912DR17F0192. 9 March.

AECOM. 2018b. Final Programmatic Accident Prevention Plan, Perfluorooctane Sulfonic Acid 

(PFOS) and Perfluorooctanoic Acid (PFOA) Impacted Sites ARNG Installations, Nationwide 

Contract No. W912DR-12-D-0014/W912DR17F0192. July.

AECOM. 2020. Final Preliminary Assessment Report, Winder Barrow Army Aviation Support 

Facility, Georgia. February. 

AECOM. 2021a. Final Site Inspection Uniform Federal Policy-Quality Assurance Project Plan 

Addendum, Winder Barrow Army Aviation Support Facility, Georgia, Perfluorooctane Sulfonic 

Acid (PFOS) and Perfluorooctanoic Acid (PFOA) Impacted Sites ARNG Installations, 

Nationwide. September. 

AECOM. 2021b. Final Site Safety and Health Plan, Army Aviation Support Facility, Winder Barrow 

Army Aviation Support Facility, Georgia, Perfluorooctane Sulfonic Acid (PFOS) and 

Perfluorooctanoic Acid (PFOA) Impacted Sites ARNG Installations, Nationwide. September. 

Assistant Secretary of Defense. 2019. Investigation Per- and Polyfluoroalkyl Substances within 

the Department of Defense Cleanup Program. United States Department of Defense. 

15 October.

City of Winder Water Works. 2019. 2018 Water Quality Report. June.

DA. 2016. Army Guidance to Address Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic 

Acid (PFOA) Contamination. August.

DA. 2018. Army Guidance for Addressing Releases of Per- and Polyfluoroalkyl Substances. 

4 September.

Higgins, C.P., and Luthy, R.G. 2006. Sorption of perfluorinated surfactants on 

sediments. Environmental Science and Technology 40 (23): 7251-7256.

ITRC. 2018. Environmental Fate ant Transport for Per- and Polyfluoroalkyl Substances. March. 

Metropolitan North Georgia Water Planning District. 2016. Water Resource Management Plan: 

Upper Oconee River Basin Profile. October.

USACE. 2016. Technical Project Planning Process, EM-200-1-2. 26 February.

USEPA. 1980. Comprehensive Environmental Response, Compensation, and Liability Act 

(CERCLA). 

USEPA. 1994. National Oil and Hazardous Substances Pollution Contingency Plan (Final Rule). 

40 CFR Part 300; 59 Federal Register 47384. September.

USEPA. 2001. Risk Assessment Guidance for Superfund, Volume I: Human Health Evaluation 

Manual (Part D, Standardized Planning, Reporting, and Review of Superfund Risk 

Assessments). December.

USEPA. 2005. Federal Facilities Remedial Site Inspection Summary Guide. 
Site Inspection Report

Winder Barrow Army Aviation Support Facility, Georgia

AECOM 9-2

USEPA. 2006. Guidance on Systematic Planning using the Data Quality Objectives Process. 

February.

USEPA. 2016a. Drinking Water Health Advisory for Perfluorooctanoic Acid (PFOA). Office of 

Water (4304T). Health and Ecological Criteria Division, Washington, DC 20460. US USEPA 

Document Number: 822-R-16-005. May 2016.

USEPA. 2016b. Drinking Water Health Advisory for Perfluorooctane Sulfonate (PFOS). Office of 

Water (4304T). Health and Ecological Criteria Division, Washington, DC 20460. US USEPA 

Document Number: 822-R-16-004. May 2016.

USEPA. 2017a. UCMR 3 (2013-2015) Occurrence Data by State. Occurrence Data for the 

Unregulated Contaminant Monitoring Rule. Accessed 9 July 2019 at https://www.epa.gov/

dwucmr/occurrence-data-unregulated-contaminant-monitoring-rule. January.

USFWS. 2021. Species by County Report, County: Barrow, Georgia. Environmental Conservation 

Online System. Accessed 10 November 2021 at https://ecos.fws.gov/ecp/report/specieslistings-by-current-range-county?fips=13013. 

USEPA. 2021. Technical Fact Sheet: Toxicity Assessment for PFBS. https://www.epa.gov/

pfas/learn-about-human-health-toxicity-assessment-pfbs. 8 April.

University of Georgia, Department of Geology, 2015. The Geology of Georgia. 

University of Georgia Institute of Ecology, 2002. Summit to the Sea program, Georgia’s Aquifers.

April. 

USGS. 2017. Groundwater Quality in the Piedmont and Blue Ridge Crystalline-Rock Aquifers, 

Eastern United States. May. 

World Climate. 2022. Climate Charts, Winder, Georgia. Available at 

http://www.worldclimate.com/climate/us/georgia/winder (Accessed 10 February 2022)

Xiao, F., Simcik, M. F., Halbach, T. R., and Gulliver, J. S. 2015, Perfluorooctane sulfonate (PFOS) 

and perfluorooctanoate (PFOA) in soils and groundwater of a U.S. metropolitan area: 

Migration and implications for human exposure. Water Research 72: 64-74.