FINAL 

Site Inspection Report 

Chesterfield Limited Army Aviation Support 

Facility 

Chesterfield, Virginia 

Site Inspections for Perfluorooctanoic Acid (PFOA), Perfluorooctanesulfonic Acid (PFOS), 

Perfluorohexanesulfonic Acid (PFHxS), Perfluorononanoic acid (PFNA), Hexafluoropropylene 

oxide dimer Acid (HFPO-DA) and Perfluorobutanesulfonic Acid (PFBS) 

April 2023 

Prepared for: 

Army National Guard Headquarters 

111 S. George Mason Drive 

Arlington, VA 22204 

UNCLASSIFIED
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TABLE OF CONTENTS

Page

LIST OF APPENDICES ................................................................................................................. v

LIST OF FIGURES ........................................................................................................................ v

LIST OF TABLES ......................................................................................................................... vi

LIST OF ACRONYMS AND ABBREVIATIONS ..................................................................... vii

EXECUTIVE SUMMARY ...................................................................................................... ES-1

1. INTRODUCTION ............................................................................................... 1-1

1.1 PROJECT AUTHORIZATION ............................................................... 1-1

1.2 SITE INSPECTION PURPOSE .............................................................. 1-1

2. SITE BACKGROUND ........................................................................................ 2-1

2.1 FACILITY LOCATION AND DESCRIPTION ..................................... 2-1

2.2 FACILITY ENVIRONMENTAL SETTING .......................................... 2-1

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

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

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

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

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

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

2.3 HISTORY OF PFAS USE ....................................................................... 2-3

2.4 HISTORICAL PFAS INVESTIGATIONS ............................................. 2-4

3. SUMMARY OF AREAS OF INTEREST ........................................................... 3-2

3.1 AOI 1 – BUILDING 7431 ....................................................................... 3-2

3.2 ADJACENT SOURCES .......................................................................... 3-2

3.2.1 Chesterfield County Fire Station #15 ....................................... 3-2

3.2.2 Wildland Fire ............................................................................ 3-2

4. PROJECT DATA QUALITY OBJECTIVES ..................................................... 4-4

4.1 PROBLEM STATEMENT ...................................................................... 4-4

4.2 INFORMATION INPUTS ....................................................................... 4-4

4.3 STUDY BOUNDARIES ......................................................................... 4-4

4.4 ANALYTICAL APPROACH ................................................................. 4-4

4.5 DATA USABILITY ASSESSMENT ...................................................... 4-2

5. SITE INSPECTION ACTIVITIES ...................................................................... 5-1
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5.1 PRE-INVESTIGATION ACTIVITIES................................................... 5-2

5.1.1 Technical Project Planning .......................................................5-2

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

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

5.2 SOIL BORINGS AND SOIL SAMPLING............................................. 5-3

5.3 TEMPORARY WELL INSTALLATION AND GROUNDWATER 

GRAB SAMPLING................................................................................. 5-4

5.4 SYNOPTIC WATER LEVEL MEASUREMENTS ............................... 5-4

5.5 SURVEYING .......................................................................................... 5-5

5.6 INVESTIGATION-DERIVED WASTE................................................. 5-5

5.7 LABORATORY ANALYTICAL METHODS ....................................... 5-5

5.8 DEVIATIONS FROM UFP-QAPP ADDENDUM................................. 5-5

6. SITE INSPECTION RESULTS ..........................................................................6-3

6.1 SCREENING LEVELS ........................................................................... 6-3

6.2 SOIL PHYSIOCHEMICAL ANALYSES .............................................. 6-4

6.3 AOI 1 ....................................................................................................... 6-4

6.3.1 AOI 1 – Soil Analytical Results................................................6-4

6.3.2 AOI 1 – Groundwater Analytical Results.................................6-5

6.3.3 AOI 1 – Conclusions.................................................................6-5

6.4 FACILITY BOUNDARY LOCATIONS................................................ 6-5

6.4.1 Facility Boundary Locations – Soil Analytical Results............6-5

6.4.2 Facility Boundary Locations – Groundwater Analytical Results..

6-6

6.4.3 Facility Boundary Locations – Conclusions.............................6-6

7. EXPOSURE PATHWAYS..................................................................................7-1

7.1 SOIL EXPOSURE PATHWAY.............................................................. 7-1

7.1.1 AOI 1 – Building 7431 .............................................................7-1

7.2 GROUNDWATER EXPOSURE PATHWAY........................................ 7-2

7.2.1 AOI 1 − Building 7431 .............................................................7-2

7.3 SURFACE WATER AND SEDIMENT EXPOSURE PATHWAYS..... 7-2

8. SUMMARY AND OUTCOME ..........................................................................8-1

8.1 SITE INSPECTION ACTIVITIES SUMMARY.................................... 8-1

8.2 OUTCOME.............................................................................................. 8-1
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9. REFERENCES ....................................................................................................9-1

LIST OF APPENDICES

Appendix A. Data Usability Assessment and Data Validation Reports

Appendix B. Field Documentation

B1. Log of Daily Notice of Field Activities

B2. Sampling Forms 

B3. Survey Data

Appendix C. Photographic Log

Appendix D. Technical Project Planning Meeting Minutes

Appendix E. Boring Logs and Well Construction Diagrams

Appendix F. Analytical Results

Appendix G. Laboratory Reports

LIST OF FIGURES

Figure 2-1. Facility Location

Figure 2-2. Topography

Figure 2-3. Groundwater Features

Figure 2-4. Surface Water Features

Figure 2-5. Groundwater Elevations, July 2021

Figure 3-1. Areas of Interest

Figure 5-1. Site Inspection Sample Locations

Figure 6-1. PFOS Detections in Soil (AOI 1)

Figure 6-2. PFOA Detections in Soil (AOI 1)

Figure 6-3. PFBS Detections in Soil (AOI 1)

Figure 6-4 PFHxS Detections in Soil (AOI 1)

Figure 6-5 PFNA Detections in Soil (AOI 1)

Figure 6-6 PFOS, PFOA, and PFBS Detections in Groundwater (AOI 1)

Figure 6.7 PFHxS and PFNA Detections in Groundwater (AOI 1)

Figure 7-1 Conceptual Site Model, AOI 1
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LIST OF TABLES

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

Table ES-2. Summary of Site Inspection Findings and Recommendations

Table 5-1. Samples by Medium, Chesterfield Limited Army Aviation Support Facility, 

Virginia Site Inspection Report

Table 5-2. Soil Boring Depths and Temporary Well Screen Intervals, Chesterfield Limited 

Army Aviation Support Facility, Virginia Site Inspection Report

Table 5-3. Groundwater Elevation, Chesterfield Limited Army Aviation Support Facility, 

Virginia Site Inspection Report

Table 6-1. Screening Levels (Soil and Groundwater)

Table 6-2. PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Surface Soil, Site 

Inspection Report, Chesterfield Limited Army Aviation Support Facility, 

Virginia

Table 6-3. PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Shallow Subsurface Soil, 

Site Inspection Report, Chesterfield Limited Army Aviation Support Facility, 

Virginia

Table 6-4. PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Deep Subsurface Soil, Site 

Inspection Report, Chesterfield Limited Army Aviation Support Facility, 

Virginia

Table 6-5. PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Groundwater, Site 

Inspection Report, Chesterfield Limited Army Aviation Support Facility, 

Virginia

Table 8-1. Summary of Site Inspection Findings and Recommendations
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LIST OF ACRONYMS AND ABBREVIATIONS

°C Degrees Celsius

°F Degrees Fahrenheit

% Percent

μg/kg Microgram(s) per kilogram

AASF Army Aviation Support Facility 

AECOM AECOM Technical Services, Inc. 

AFFF Aqueous film forming foam

Amsl Above mean sea level

AOI Area of Interest

ARNG Army National Guard

bgs Below ground surface

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act

CSM Conceptual site model

DoD Department of Defense

DPT Direct-push technology

DQO Data Quality Objectives

DUA Data Usability Assessment

EA EA Engineering, Science, and Technology, Inc., PBC

EB Equipment blank 

EDRTM Environmental Data Resources, Inc.

ELAP Environmental Laboratory Accreditation Program

EM Engineer Manual

FB Field blank

FD Field duplicate

FedEx Federal Express

ft Foot (feet)

ft2 Square foot (feet)

HDPE High-density polyethylene

HFPO-DA Hexafluoropropylene oxide-dimer acid

IDW Investigation-derived waste

in. Inch(es)

ITRC Interstate Technology Regulatory Council

LC/MS/MS Liquid Chromatography Tandem Mass Spectrometry

MS Matrix spike

MSD Matrix spike duplicate
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LIST OF ACRONYMS AND ABBREVIATIONS (continued)

ng/L Nanogram(s) per liter

No. Number

OSD Office of the Secretary of Defense

PA Preliminary Assessment

PFAS Per- and polyfluoroalkyl substances

PFBS Perfluorobutanesulfonic acid

PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

PFOA Perfluorooctanoic acid

PFOS Perfluorooctanesulfonic acid

PVC Polyvinyl chloride

QAPP Quality Assurance Project Plan

QSM Quality Systems Manual

RI Remedial investigation 

SI Site Inspection

SL Screening level

TOC Total organic carbon

TPP Technical Project Planning

UFP Uniform Federal Policy 

USACE U.S. Army Corps of Engineers

USEPA U.S. Environmental Protection Agency

VAARNG Virginia Army National Guard
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EXECUTIVE SUMMARY

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

Inspections (SIs) at ARNG facilities nationwide based on the current or potential historical use of

per- and polyfluoroalkyl substances (PFAS) with a focus on the six compounds presented in the 

memorandum from the Office of the Secretary of Defense (OSD) (Assistant Secretary of 

Defense) dated 6 July 2022. The six compounds listed in the OSD memorandum include 

perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and 

perfluorobutanesulfonic acid (PFBS), perfluorononanoic acid (PFNA), perfluorohexanesulfonic 

acid (PFHxS), and hexafluoropropylene oxide dimer acid (HFPO-DA)1. These compounds are 

collectively referred to as “relevant compounds” throughout the document and the applicable 

Screening Levels (SLs) are provided below in Table ES-1.

The PA identified Areas of Interest (AOIs) where PFAS-containing materials were used, stored, 

and/or disposed, or areas where known or suspected releases to the environment occurred. The 

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

AOIs identified in the PA and determine whether further investigation is warranted, a removal 

action is required to address immediate threats, or no further action is required based on a 

comparison of SI results to SLs for the relevant compounds. This SI was completed at the 

Chesterfield Limited Army Aviation Support Facility (AASF) in Chesterfield, Virginia, and 

determined further investigation is warranted for AOI 1 – Building 7431. The AASF will be 

referred to as the “Site or Facility” throughout this document. 

The Facility, operated by the Virginia ARNG (VAARNG), consists of approximately 2.7 acres

within the Chesterfield County Airport in Chesterfield, Virginia, approximately 16 miles 

southwest of Richmond. The facility consists of 19,500 square feet (ft2

) of hangar space, 

2,218 ft2 of office space, and associated aircraft parking areas. The Facility’s current lease began 

in 2013. Chesterfield Limited AASF is located within the eastern Piedmont Physiographic 

Province of Virginia near the fall line, which separates the Piedmont and the Coastal Plain 

physiographic provinces.

The PA identified one AOI for investigation during the SI phase. SI sampling results from the 

AOI were compared to OSD SLs. Table ES-2 summarizes the SI results for the AOI. 

Based on the results of this SI, and following the CERCLA process, a remedial investigation (RI) 

is warranted for AOI 1: Building 7431.

1 Of the six PFAS compounds presented in the 6 July 2022 OSD memorandum, HFPO-DA (commonly referred to as 

GenX) was not included as an analyte at the time of this SI. Based on the conceptual site model (CSM) developed 

during the PA and revised based on SI findings, the presence of HFPO-DA is not anticipated at the facility because 

HFPO-DA is generally not a component of military specification (MIL-SPEC) aqueous film forming foam (AFFF) 

and based on its history including distribution limitations that restricted use of GenX, it is generally not a component 

of other products the military used. In addition, it is unlikely that GenX would be an individual chemical of concern 

in the absence of other PFAS.
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Table ES-1. Screening Levels (Soil and Groundwater)

Analyte

Residential

(Soil)

(μg/kg)

1 

Industrial / Commercial

Composite Worker

(Soil)

(μg/kg)

1 

Tap Water

(Groundwater)

(ng/L)1 

PFOA 19 250 6

PFOS 13 160 4

PFBS 1,900 25,000 601

PFHxS 130 1,600 39

PFNA 19 250 6

Notes:

1. OSD. 2022. Risk Based Screening Levels Calculated for Groundwater and Soil using U.S. 

Environmental Protection Agency’s (USEPA’s) Regional Screening Level Calculator. Hazard 

Quotient=0.1. 6 July 2022

2. Of the six PFAS compounds presented in the 6 July 2022 OSD memorandum, HFPO-DA 

(commonly referred to as GenX) was not included as an analyte at the time of this SI. Based on the 

conceptual site model (CSM) developed during the PA and revised based on SI findings, the 

presence of HFPO-DA is not anticipated at the facility because HFPO-DA is generally not a 

component of military specification (MIL-SPEC) aqueous film forming foam (AFFF) and based on 

its history including distribution limitations that restricted use of GenX, it is generally not a 

component of other products the military used. In addition, it is unlikely that GenX would be an 

individual chemical of concern in the absence of other PFAS. 

μg/kg = Microgram(s) per kilogram

ng/L = Nanogram(s) per liter

Table ES-2. Summary of Site Inspection Findings and Recommendations

AOI

Potential Release 

Area

Soil

Source Area

Groundwater

Source Area

Groundwater

Facility Boundary Future Action

1 Building 7431 Proceed to RI

Legend:

 = Detected; exceedance of screening levels

 = Detected; no exceedance of screening levels

 = Not detected
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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) at ARNG facilities nationwide based on the current 

or potential historical use of per- and polyfluoroalkyl substances (PFAS) with a focus on six 

compounds presented in the memorandum from the Office of the Secretary of Defense (OSD) 

dated 6 July 2022 (Assistant Secretary of Defense 2022). The six components listed in the OSD

memorandum will be referred to as “relevant compounds” throughout this document and include 

perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorobutanesulfonic 

acid (PFBS), perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), and 

hexafluoropropylene oxide-dimer acid (HFPO-DA) 2 at ARNG facilities nationwide. The 

ARNG performed this SI at the Chesterfield Limited Army Aviation Support Facility (AASF) in 

Chesterfield, Virginia . The Chesterfield Limited AAFS will be referred to as the “Site” or 

“Facility” throughout this report. 

The SI project elements were performed in accordance with the Comprehensive

Environmental Response, Compensation, and Liability Act (CERCLA) (U.S. 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 Army requirements and guidance for field investigations.

1.2 SITE INSPECTION PURPOSE

A PA was performed at the Chesterfield Limited AAFS (AECOM Technical Services, Inc. 

[AECOM] 2020) that identified one Area of Interest (AOI) where PFAS-containing materials 

were used, stored, and/or disposed, or areas where known or suspected releases to the 

environment occurred. The objective of the SI is to identify whether there has been a release to 

the environment from the AOI identified in the PA and determine whether further investigation 

is warranted, a removal action is required to address immediate threats, or no further action is 

required based on screening levels (SLs) for the relevant compounds. 

2 Of the six PFAS compounds presented in the 6 July 2022 OSD memorandum, HFPO-DA (commonly referred to as 

GenX) was not included as an analyte at the time of this SI. Based on the conceptual site model (CSM) developed 

during the PA and revised based on SI findings, the presence of HFPO-DA is not anticipated at the facility because 

HFPO-DA is generally not a component of military specification (MIL-SPEC) aqueous film forming foam (AFFF) 

and based on its history including distribution limitations that restricted use of GenX, it is generally not a component 

of other products the military used. In addition, it is unlikely that GenX would be an individual chemical of concern 

in the absence of other PFAS.
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2. SITE BACKGROUND

2.1 FACILITY LOCATION AND DESCRIPTION

The Chesterfield Limited AASF is located within the Chesterfield County Airport in 

Chesterfield, Virginia, near the interchange of Route 10 and Route 288 (Figure 2-1). The facility

consists of 19,500 square feet (ft2) of hangar space (Buildings 7431 and 7417), 2,218 ft2 of 

second floor office space (Building 7501), and associated aircraft parking areas. Building 7431 

is approximately 9,500 ft2 with approximately 1,000 ft2 used for office space. The remaining 

portion is used as a hangar. Building 7431 was constructed in 1979, and office space renovations 

were completed in 2010. The previous tenant was A.T. Massey Corporation. Virginia Army 

National Guard (VAARNG) acquired the property from the Chesterfield County Airport, via 

lease in May 2013 (AECOM 2020). A second building, Building 7417, was built in 2005 and 

acquired by VAARNG via lease from the Chesterfield County Airport in May 2013. The 

building footprint is approximately 10,000 ft2. The interior is used as a large hangar space that 

has a clear-span frame and a concrete slab floor. The hangar houses several aircraft and stores 

maintenance chemicals and materials. A third building, Building 7501 to the north of Building 

7431, is used by VAARNG for additional office space. The remainder of this building is used as 

a hangar by other entities. No information on the specific use or contents of Building 7501 was 

identified in the PA. As noted, the property is leased by the VAARNG from the Chesterfield 

County Airport, which is owned and operated by Chesterfield County, Virginia. Access to the 

Site is provided through Airfield Drive.

2.2 FACILITY ENVIRONMENTAL SETTING

The topography of the site generally resides at a surface elevation of approximately 205 feet (ft)

above mean sea level (amsl) and slopes slightly to the southeast, according to maps derived from 

a U.S. Geological Survey 7.5 ́ Digital Elevation Model and confirmed during surveying 

conducted as part of the SI. Adjacent properties to the airport include an industrial park to the 

west, Virginia Route 10 to the south, undeveloped woodland to the east, and a residential area to 

the north. Chesterfield Limited AASF is located within the eastern Piedmont Physiographic 

Province of Virginia (AECOM 2020).

2.2.1 Geology

The Chesterfield Limited AASF is located in the eastern Piedmont Physiographic Province of 

Virginia. The Site is located near the fall line, which separates the Piedmont and the Coastal 

Plain physiographic provinces. The Facility is located in the approximate boundary between 

highlands erosion to the west, and deposition in the lowlands to the east. The uppermost geologic 

unit at Chesterfield Limited AASF is the Tertiary-age unconsolidated sand and gravel. These 

deposits are thin outliers from the Coastal Plain and they directly overlie the weathered 

Mississippian-age granite bedrock. These commonly oxidized yellow-orange to yellow-brown 

deposits represent a fluvial to marginal-marine depositional environment and may be genetically 

related to the facies of the Choptank Formation (AECOM 2020).

As indicated in the 2019 Environmental Data Resources, Inc. (EDRTM) report, there are three 

major soil components found at the Chesterfield Limited AASF property: Coalfax Variant, 
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Bourne, and Aquults. These fine sandy loams are moderately to poorly drained and possess a 

high corrosion potential (AECOM 2020). Soils encountered during the SI activities were 

predominantly clays.

During the SI, the soil underlying Chesterfield Limited AASF was found to be generally 

composed of light brown to dark brown silty clay, which transitions to yellowish brown clay. 

Layers of silty sand and clayey sand were encountered just above highly weathered bedrock. The 

borings were completed at depths between 17.5 to 20 ft below ground surface (bgs). Samples for 

grain size analyses were collected at two locations, AOI01-SB-4 and AOI01-SB-5 and analyzed 

via ASTM International (ASTM) Method D-422. The results indicate that the soil samples are 

comprised primarily of silt (20 to 60 percent [%]), clay (16 to 34%), and sand (6 to 22%). Boring 

logs are presented in Appendix E and grain size results are presented in Appendix F.

2.2.2 Hydrogeology

The shallow water-table aquifer (Yorktown aquifer) comprises fine-grained quartz sand 

interbedded with silt and clay laminae. The Yorktown aquifer is underlain by three confined 

artesian aquifers. The 2019 EDRTM report indicated that no drinking water supply wells are 

present within a 1-mile radius of the Facility. At the time of the PA, depth to groundwater was

inferred to occur between 1 and 15 ft bgs. The shallow water-table aquifer is unconfined; 

therefore, groundwater flows under the influence of gravity, with flow patterns resembling a 

subdued reflection of local topography. As such, shallow groundwater flow across the entire 

installation was assumed to flow to the east/southeast towards Reedy Creek or southerly towards 

Swift Creek and that groundwater discharges to local streams in the area within the James River 

Basin (Figure 2-3) (AECOM 2020). During the SI, depth to water ranged from 3.6 to 9.5 ft bgs. 

Groundwater elevations calculated using depth to groundwater measurements and survey data 

collected during the SI indicate groundwater within the shallow underlying aquifer flows 

primarily to the northwest.

An EDRTM report conducted a well search for a 1-mile radius surrounding the facility. Using 

additional online resources, such as state and local geographic information system databases, 

wells were researched to a 4-mile radius of the Facility. Groundwater is not used for drinking 

water at the Chesterfield County Airport. Public water services are provided to airport facilities 

by Chesterfield County, which sources its water from Lake Chesdin, located approximately 

12 miles south of the Facility. Multiple groundwater wells are located within a 4-mile radius of 

the Facility and are classified as domestic, public/municipal/government, and unknown. 

According to available data, there are three domestic and one public/municipal/government wells 

located south/southeast and downgradient of the facility. 

2.2.3 Hydrology

There are no wetlands adjacent to the Chesterfield Limited AASF, although the surrounding 

airport property includes approximately 65 acres of wetlands. According to the Chesterfield 

County Airport Stormwater Pollution Prevention Plan, revised on 12 January 2015, stormwater 

runoff from the airport generally flows southeast towards Reedy Creek, although surface water in 

the northern property may also discharge to Licking Creek or through wetlands into Cosby Lake. 

Overland sheet flow is conveyed to one of seven outfall areas. Chesterfield Limited AASF is 
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located within the Outfall #2 drainage area, which consists of a 48-inch (in.) reinforced concrete 

pipe located at the southeastern end of the runway. Outfall #2 receives runoff from the runway, 

parking lots, apron, and hangar buildings, and directly discharges into Reedy Creek. All surface 

water from the property eventually discharges into the James River approximately 7 miles east of 

the airport boundary (AECOM 2020). Surface water flow patterns are presented in Figure 2-4.

2.2.4 Climate

The climate of Chesterfield, Virginia, is characterized as humid sub-tropical. The hot season lasts 

approximately 3.6 months between May and September and experiences normal maximum and 

minimum temperatures of 88 degrees Fahrenheit (°F) and 67°F, respectively. The cold season 

lasts approximately 3 months between December and March and experiences normal maximum 

and minimum temperatures of 50°F and 30°F, respectively (AECOM 2020). 

Although precipitation is fairly well distributed throughout the year, Chesterfield experiences 

some seasonal variation in monthly rainfall. On average, the most precipitation occurs in the 

month of August, with an average total accumulation of 4.7 in., and the least precipitation occurs 

in the month of February, with an average total accumulation of 2.8 in. (AECOM 2020).

2.2.5 Current and Future Land Use

Prior to the 1970s, the current location of the Chesterfield County Airport was largely 

undeveloped. Construction of the airport began in 1972 and included the acquisition of 556 acres 

of land for runways, hangar facilities, terminal buildings, and parking areas. The current lease of 

the Chesterfield Limited AASF property began in 2013. Future land use is not expected to 

change (AECOM 2020). 

2.2.6 Sensitive Habitat and Threatened/Endangered Species

A wildlife survey has not occurred at the Facility, and the Facility does not have any significant 

areas of habitat. The following species are listed as federally endangered, threatened, proposed, 

and/or candidate species in Chesterfield County, Virginia (U.S. Fish and Wildlife Service 2021):

• Flowering Plants: Sensitive Joint-vetch, Aeschynomene virginica, Threatened; Swamp 

Pink, Helonias bullata, Threatened 

• Mollusks: Atlantic Pigtoe, Fusconaia masoni, Proposed Threatened

• Mammal: Northern Long-eared Bat, Myotis septentrionalis, Threatened.

2.3 HISTORY OF PFAS USE

Aqueous film forming foam (AFFF), a firefighting agent, was commonly used by the United 

States military to extinguish petroleum fires, for firefighting training, and for the suppression of 

fires in uncontained areas. Military use of AFFF began in the 1970s and was most widely used at 

DoD installations with airfields. 
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One potential PFAS release area was identified at the facility during the PA (AECOM 2020). A 

mobile Tri-MaxTM fire extinguisher was observed to be staged outside the southern corner of the

hangar during the visual site inspection. The storage or use of AFFF at the facility by ARNG 

could not be confirmed by interviews and records obtained during the PA. A description of the

AOI is presented in Section 3.

2.4 HISTORICAL PFAS INVESTIGATIONS

No previous PFAS investigations have been conducted at or within the vicinity of Chesterfield 

Limited AASF.
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Chesterfield Limited AASF, Virginia

Figure 2-1

Facility Location

Chesterfield Limited AASF

Chesterfield

County Airport

3

0 2

Miles

Facility Data

Facility Boundary

Chesterfield County Airport

VA ^_

Data Sources:

ESRI 2020

AECOM 2020

Date:....................... April 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N
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Figure 2-2

Topography

Chesterfield Limited AASF

3

0 1,000

Feet

Facility Data

Facility Boundary

VA ^_

Data Sources:

ESRI 2020

AECOM 2020

Date:....................... April 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N
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Figure 2-3

Groundwater Features

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<!

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<!<!

<!<!

<!

<!

<!

Falling Creek

Swift Creek

Proctors Creek

Grindall Creek

Kingsland Creek

Reedy Creek

Great Branch

Horners Run

Crooked Branch

Watch Run

First Branch

Licking Creek

Licking Creek

Nash

Road Lake

Swift Creek Lake

Gregorys

Pond

Cosbys Lake

Licking Creek

Fishing Club Lake

Napiers and

Savage Lake 3

0 1

Miles

Facility Data

Facility Boundary

Chesterfield County Airport

Well Type

<! Domestic

<!

Public/Municipal/

Government

Hydrology/Hydrogeology

Inferred Regional Groundwater Flow Direction

Perennial Creek/Stream

Intermittent Creek/Stream

Waterbody

Wetlands

VA ^_

Data Sources:

ESRI 2020

AECOM 2020

Date:...................... April 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N

*Inferred regional groundwater flow direction is

based on regional flow, as presented in the PA.
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Figure 2-4

Surface Water Features

Falling Creek

Swift Creek

Proctors Creek

Kingsland Creek

Reedy Creek

Great Branch

Horners Run

Crooked Branch

Watch Run

First Branch

Licking Creek

Licking Creek

Nash

Road Lake

Swift Creek Lake

Gregorys

Pond

Cosbys Lake

Licking Creek

Fishing Club Lake

Falling Creek Watershed

Proctors Creek-James

River Watershed

Third Branch-Swift

Creek Watershed

Second Branch-Licking

Creek Watershed

3

0 1

Miles

Facility Data

Facility Boundary

Chesterfield County Airport

Hydrology

Surface Water Flow Direction

Perennial Creek/Stream

Intermittent Creek/Stream

Waterbody

Wetlands

Watershed Boundary

VA ^_

Data Sources:

ESRI 2020

AECOM 2020

NWI 2021

Date:...................... April 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N

Outfall 2
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Figure 2-5

Groundwater Elevations, July 2021

<!

<!

<!

<!

<!

<!

<!

AOI 1

Building 7417

Building 7431

AOI01-04

199.2

AOI01-03

199.8

AOI01-02

199.1

CHAASF-02

198.3 CHAASF-01

198.5

CHAASF-03

200.9

AOI01-01

198.9

198

199

200

Building 7501

3

0 100

Feet

Facility Data

Facility Boundary

Area of Interest

Potential PFAS Release

No Suspected Release

Chesterfield County Airport

Hydrogeology

<! Well Location

Groundwater Flow Direction

Groundwater Elevation

Contour Interval (1 Foot)

Dashed where Inferred

VA ^_

Data Sources:

ESRI 2020

AECOM 2020

AOI01-01 = Sample ID

198.9 = Groundwater Elevation (in feet)

Date:...................... April 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N

*Local groundwater flow direction was

refined based on groundwater elevations

identified during the SI.
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3. SUMMARY OF AREAS OF INTEREST

The PA evaluated areas where PFAS-containing materials may have been used, stored, disposed, 

or released historically. Based on the PA findings, one potential release area was identified at the 

Facility: AOI 1 - Building 7431. The potential AOI is shown on Figure 3-1. 

3.1 AOI 1 – BUILDING 7431

AOI 1 consists of a one-story building located at 7431 Airfield Drive, North Chesterfield, 

Virginia 23237. The building is approximately 9,500 ft2 with approximately 1,000 ft2 used for 

office space. The remaining portion is used as a hangar. Building 7431 was constructed in 1979, 

and office space renovations were completed in 2010. The previous tenant was A.T. Massey 

Corporation. VAARNG acquired the property from the County of Chesterfield, Virginia, via 

lease in May 2013 (AECOM 2020). 

During the PA visual SI, no evidence was found of an AFFF system or fire extinguishers

containing AFFF having been stored in the hanger. According to an interview with the 

Chesterfield County Airport Operations Manager, AFFF has not been stored historically or 

currently at Building 7431. A mobile Tri-MaxTM fire extinguisher was observed staged outside 

the southern corner of the hangar. At the time of the SI field event, the extinguisher was 

observed staged between Buildings 4731 and 7501. The contents of the Tri-MaxTM fire 

extinguisher are unknown; however, the Operations Manager stated that the Tri-MaxTM had 

never been used or tested to his knowledge, which spans back to 2001 and covers the entire 

period of interest (2013−present) (AECOM 2020). During the interview process, no VAARNG 

personnel were available to be interviewed to clarify the findings or provide additional insight as 

to why the Tri-MaxTM fire extinguisher was present. 

3.2 ADJACENT SOURCES

Two potential off-facility sources of PFAS are adjacent to the Facility and are not under the 

control of the VAARNG. A description of each off-facility source is presented below and shown 

on Figure 3-1. 

3.2.1 Chesterfield County Fire Station #15

Chesterfield County Fire Station #15 is located at 7300 Airfield Drive, North Chesterfield, 

Virginia 23237, in the adjoining property southeast of Chesterfield Limited AASF. The fire 

station resides on approximately 0.75 acre and also includes a helipad and backyard field. The 

fire station provides emergency services to the Chesterfield Limited AASF (AECOM 2020). 

An interview with the Battalion Chief for Chesterfield Fire & EMS revealed that minor amounts 

of AFFF were released through weekly spray pattern testing of equipment in the field adjacent to 

and behind the fire station from 1989 until 2017, when there were some equipment issues. While 

weekly spray pattern testing currently occurs in the same location with water, residual PFAS 

may have been released from the previous testing of equipment with AFFF. It is unknown what 

may have occurred before the Battalion Chief’s tenure starting in 2002 (AECOM 2020). 
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The AFFF products used by the station are National Foam Universal Plus 3x6 AR-AFFF, 

National Foam Universal Goal 1x3 AR-AFFF, and Ansul AFFF, varying in concentration from 

1 to 6 % and stored in 5-gallon buckets and two totes of 275- and 330-gallon capacity. A foam 

response trainer is currently stationed at Fire Station #15. Two P-19 Aircraft Rescue Firefighting 

vehicles are also associated with the fire station. An old fire engine is reported to have leaked 

product at the Chesterfield Fire & EMS on AASF property (AECOM 2020). The Chesterfield 

County Fire Station #15 is considered a cross-gradient/upgradient off-facility source area based 

on the SI findings. 

3.2.2 Wildland Fire

In 2013, a large brush fire occurred between Route 288 and Courthouse Road, adjacent to the 

southern boundary of the Chesterfield County Airport. The brush fire impacted approximately 

75 acres. First responders reportedly used only water to extinguish the fire, and Chesterfield 

Fire & EMS staff confirmed that no AFFF was used in the emergency response (AECOM 2020). 
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Figure 3-1

Areas of Interest

Reedy Creek

Cosbys Lake

2013 Wildland Fire

Building 7417

Building 7431

Chesterfield County

Fire Station 15

AOI 1

3

0 0.5

Miles

Facility Data

Facility Boundary

Area of Interest

Potential PFAS Release

No Suspected Release

Chesterfield County Airport

Hydrology/Hydrogeology

Surface Water Flow Direction

Local Inferred Groundwater Flow Direction

Perennial Creek/Stream Intermittent Creek/

Stream Waterbody

Wetlands

VA ^_

Data Sources:

ESRI 2020

AECOM 2020

NWI 2021

Date:.......................January 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N

*Local groundwater flow direction was refined based on groundwater elevations 

identified during the SI.
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4. PROJECT DATA QUALITY OBJECTIVES

As identified during the data quality objective (DQO) process and outlined in the SI Uniform 

Federal Policy- (UFP) Quality Assurance Project Plan (QAPP) Addendum (EA Engineering, 

Science, and Technology, Inc., PBC [EA] 2021a), the objective of the SI is to identify whether 

there has been a release to the environment at the AOIs identified in the PA. For each AOI, 

ARNG determines if further investigation is warranted, a removal action is required to address 

immediate threats, or whether no further action is warranted. This SI evaluated groundwater and 

soil for presence or absence of relative compounds at each of the sampled AOIs.

4.1 PROBLEM STATEMENT

ARNG will recommend AOIs for remedial investigation (RI) if site-related soil and groundwater 

samples have concentrations of the relevant compounds above the OSD risk-based screening 

levels. The SLs are presented in Section 6.1 of this report. 

4.2 INFORMATION INPUTS

Primary information inputs for the SI include the following:

• The PA Report for the Chesterfield Limited AASF

• Analytical data collected during other environmental sampling efforts at the Chesterfield

Limited AASF

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

accordance with the UFP-QAPP Addendum (EA 2021a)

• Field data collected including groundwater elevation and water quality parameters

measured at the time of sampling.

4.3 STUDY BOUNDARIES

The scope of the SI was bounded horizontally by the property limits of the Facility (Figure 2-2). 

Off-site sampling was not included in the scope of this SI. If future off-site sampling is required, 

the proper stakeholders will be notified, and necessary rights of entry will be obtained by ARNG 

with property owner(s). Temporal boundaries were limited to the earliest available time field 

resources were available to complete the study.

4.4 ANALYTICAL APPROACH

Samples were analyzed by Eurofins Lancaster Laboratories Env, LLC, accredited under the 

DoD Environmental Laboratory Accreditation Program (ELAP); (DoD ELAP; Accreditation 

No. 1.01) and the National Environmental Laboratory Accreditation Program; Certificate 

No.1.01). PFAS data underwent 100 % Stage 2B validation in accordance with the DoD General 

Data Validation Guidelines (2019 and DoD Data Validation Guidelines Module 3: Data 
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Validation Procedure of Per- and Polyfluoroalkyl Substances Analysis by Quality Systems 

Manual (QSM) Table B-15 (2020). PFAS data were compared to applicable SLs and decision 

rules as defined in the UFP-QAPP Addendum (EA 2021a). 

4.5 DATA USABILITY ASSESSMENT

The Data Usability Assessment (DUA), which is provided in Appendix A, is an evaluation at the 

conclusion of data collection activities that uses the results of both data verification and 

validation in the context of the overall project decisions or objectives. Using both quantitative 

and qualitative methods, the assessment determines whether project execution and the resulting 

data have met installation-specific DQOs. Both sampling and analytical activities are considered 

to assess whether the collected data are of the right type, quality, and quantity to support the 

decision-making (DoD 2019; USEPA 2017b). 

Based on the DUA, the environmental data collected during the SI were found to be acceptable 

and usable for this SI evaluation with the qualifications documented in the DUA and its 

associated data validation reports. These data are of sufficient quality to meet the objectives and 

requirements of the UFP-QAPP (EA 2021a). 
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5. SITE INSPECTION ACTIVITIES 

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

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

implemented in accordance with the following approved documents:

• Final Preliminary Assessment Report, Chesterfield Limited Army Aviation Support 

Facility (AASF), Virginia, Virginia Army National Guard dated July 2020 (AECOM 

2020)

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

Inspections for Per- and Polyfluoroalkyl Substances Impacted Sites, ARNG Installations, 

Nationwide. dated December 2020 (EA 2020a)

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

Addendum, Chesterfield Limited Army Aviation Support Facility, Chesterfield, Virginia,

dated June 2021 (EA 2021a)

• Final Programmatic Accident Prevention Plan, Revision 1 dated November 2020 (EA 

2020b)

• Final Accident Prevention Plan/Site Safety and Health Plan Addendum, Chesterfield 

Limited Army Aviation Support Facility, Virginia, dated February 2021 (EA 2021b). 

The SI field activities were conducted from 6 to 8 July 2021 and consisted of direct-push 

technology (DPT) boring and soil sample collection, temporary monitoring well installation, and

grab groundwater sample collection. Field activities were conducted in accordance with the 

UFP-QAPP Addendum (EA 2021a), except as noted in Section 5.8.

The following samples were collected during the SI and analyzed for a subset of 24 PFAS via 

liquid chromatography tandem mass spectrometry (LC/MS/MS) compliant with QSM Version 

5.3 Table B-15 to fulfill the project DQOs:

• Twenty one (21) soil samples from seven locations (soil borings locations)

• Seven (7) grab groundwater samples from seven temporary well locations.

• Three (3) field blanks (FBs)

• Five (5) equipment rinsate samples

• Four (4) field duplicate 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 medium. 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. Additionally, a photographic log of field activities is provided in 

Appendix C. 
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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 of these activities are presented below. 

5.1.1 Technical Project Planning

The U.S. Army Corps of Engineers (USACE) Technical Project Planning (TPP) Process, 

Engineer Manual (EM) 200-1-2 (Department of Army 2016a) 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 

DQOs, and formulating a sampling approach to address the AOIs identified in the PA. There was 

no Virginia Department of Environmental Quality regulatory involvement in the planning 

process; therefore, the initial meetings included ARNG, VAARNG, USACE, and representatives 

familiar with the facility. 

A TPP Meeting (no. 3) was held on 11 April 2023 to discuss the results of the SI. Meeting 

minutes for TPP 3 are included in Appendix D of this report. The stakeholders for this TPP 

included VAARNG, USACE, and the Virginia Department of Environmental Quality 

representatives familiar with the Facility, the regulations, and the community.

5.1.2 Utility Clearance

EA’s drilling subcontractor, GSI Mid-Atlantic, contacted Miss Utility of Virginia to notify them 

of intrusive work at the facility. Utility clearance was performed at each of the proposed boring 

locations on 2 July 2021 with input from the EA field team. General locating services were used 

to complete the clearance. Additionally, the first 5 ft of each boring were pre-cleared by GSI

Mid-Atlantic 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

A sample from a deionized water source at the EA Ecotoxicological Laboratory was collected on 

31 March 2021, prior to mobilization. Results of the sample confirmed this source to be 

acceptable for use in this investigation; therefore, it was used throughout the field activities. 

Specifically, the samples were analyzed by LC/MS/MS compliant with QSM 5.3 Table B-15. 

The results of the decontamination water sample associated with the wash rack spigot source 

used during the SI are provided in Appendix F. A discussion of the results is presented in the 

DUA (Appendix A).

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 (Appendix A) to the 

Programmatic UFP-QAPP (EA 2020a).
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5.2 SOIL BORINGS AND SOIL SAMPLING

Soil samples were collected via DPT drilling methods in accordance with Standard Operating 

Procedure 047 Direct-Push Technology Sampling (EA 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 5 ft of the boring in compliance with utility clearance 

procedures.

Three discrete soil samples were collected for PFAS analysis from each soil boring: one sample 

at the surface (collected from 0 to 2 ft bgs) and two subsurface soil samples. One subsurface soil 

sample was collected approximately 1 ft above the groundwater table3

, and one was collected at 

the mid-point between the surface and the groundwater table (not to exceed 15 ft bgs). 

Groundwater was encountered at depths ranging from 13 to 15 ft bgs during drilling. Total 

boring completion depths, to accommodate temporary well installation, ranged from 17.5 to 

20 ft bgs. 

Soil sample locations are shown on Figure 5-1, and boring sample depths are provided in 

Table 5-1. The soil boring locations were selected based on the AOI information provided in the 

PA (AECOM 2020) and as agreed upon by stakeholders during review of the UFP-QAPP 

Addendum (EA 2021a). 

During the drilling, the soil cores were continuously logged for lithological descriptions by a 

field geologist using the Unified Soil Classification System. A photoionization detector (PID)

was used to screen the breathing zone during boring activities as a part of personal safety 

requirements. Observations and measurements were recorded on sampling forms (Appendix B2) 

and in a non-treated field logbook. Depth interval, recovery thickness, PID concentrations, 

moisture, relative density, Munsell color, and Unified Soil Classification System texture were 

recorded. The boring logs are provided in Appendix E. 

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

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

transported via FedEx under standard chain-of-custody procedures to the laboratory and 

analyzed for PFAS (LC/MS/MS compliant with QSM Version 5.3 Table B-15), total organic 

compound (TOC) (USEPA Method 9060A) and pH (USEPA Method 9045D) in accordance with 

the UFP-QAPP Addendum (EA 2021a). 

Field duplicate (FD) 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, one equipment 

blank (EB) was collected per day 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°C during shipment. 

3 Location of groundwater interface was determined based on the depth of observed saturation in the core sample. 
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DPT borings were converted to temporary wells, which were subsequently abandoned after 

sampling and surveying in accordance with the UFP-QAPP Addendum (EA 2021a). After 

removal of the casings, boreholes were abandoned using soil cuttings and bentonite chips. 

Borings were installed in grass areas to avoid disturbing concrete or asphalt surfaces and no 

additional restoration services were required. 

5.3 TEMPORARY WELL INSTALLATION AND GROUNDWATER GRAB 

SAMPLING

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 10-ft 

section of 1-in. Schedule 40 polyvinyl chloride (PVC) screen with sufficient casing to reach 

ground surface. New PVC pipe and screen were used at each location to avoid crosscontamination between locations. The screen intervals for the temporary wells are provided in 

Table 5-2. 

Groundwater samples were collected using a peristaltic pump with PFAS-free HDPE tubing. 

Samples were collected after a period of time following well installation to allow groundwater to 

infiltrate and recharge the temporary well intervals. Each sample was collected in laboratorysupplied PFAS-free HDPE bottles and labeled using a PFAS-free marker or pen. The temporary 

wells were purged using low flow techniques 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, and oxidation-reduction potential) were measured using a 

water quality meter and recorded on the field sampling form (Appendix B2) before each grab 

sample was collected in a separate container. Samples were packaged on ice and transported via 

Federal Express (FedEx) under standard chain-of-custody procedures to the laboratory and 

analyzed for PFAS by LC/MS/MS compliant with QSM Version 5.3 Table B-15 in accordance 

with the UFP-QAPP Addendum (EA 2021a). 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. 

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

the accompanying samples. Matrix spike (MS)/matrix spike duplicates (MSDs) were collected at 

a rate of 5% and analyzed for the same parameters as the accompanying samples. Two field 

blanks (FBs) were collected in accordance with the UFP-QAPP Addendum (EA 2021a). A 

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

6°C during shipment. 

5.4 SYNOPTIC WATER LEVEL MEASUREMENTS

Groundwater levels were used to monitor site-wide groundwater elevations and assess 

groundwater flow. Synoptic water level elevation measurements were collected from the newly 

installed temporary monitoring wells, taken from the survey mark on the northern side of the 

well casing. Groundwater elevation data are provided in Table 5-3. 
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5.5 SURVEYING

The northern side of each new temporary well casing was surveyed using a Trimble R10 

real-time kinematic differential global positioning system. All vertical elevations were found 

with a Leica DNA03 Level. Positions were collected in the applicable Universal Transverse 

Mercator zone projection with World Geodetic System 1984 datum (horizontal) and North

American Vertical Datum 1988 (vertical). Surveying data were collected on 8 July 2021 and are 

provided in Appendix B3. 

5.6 INVESTIGATION-DERIVED WASTE

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

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

was managed in accordance with the Chesterfield UFP-QAPP Addendum (EA 2021a). 

As agreed upon with USACE, VAARNG, and ARNG during the 12 February 2021 

teleconference, soil IDW (i.e., soil cuttings) and liquid IDW (i.e., purge water, development 

water, and decontamination fluids) generated during the SI activities were discharged back to 

the ground surface at the completion of sampling activities4. 

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

monitoring well construction materials, and other environmental media generated during the 

field activities were disposed of off-site at a licensed solid waste landfill. 

5.7 LABORATORY ANALYTICAL METHODS 

Samples were analyzed for a subset of 24 PFAS by LC/MS/MS compliant with QSM Version 

5.3 Table B-15 at Eurofins Lancaster Laboratories Env, LLC, a DoD ELAP-certified laboratory. 

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

Method 9045D. 

5.8 DEVIATIONS FROM UFP-QAPP ADDENDUM 

Deviations from the UFP-QAPP Addendum occurred based on observed field conditions. These 

deviations were discussed between EA, ARNG, and USACE. Two deviations from the UFPQAPP Addendum are noted below: 

• Groundwater was encountered deeper than expected (14-16 ft bgs) and all borings 

were advanced to 20 ft bgs.

4 As it is considered non-hazardous waste, Liquid IDW was not tested prior to discharge.
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• Soil samples were collected from four intervals (1−2 ft, 7−8 ft, 12−13 ft, and 15−16 ft) at 

boring location AOI01-03 and only two intervals (1−2 ft and 8−9 ft) at upgradient 

boundary boring location CHAASF-03 due to a field error5.

• Deep subsurface soil samples collected at depths ranging from 12 to 16 ft bgs were 

compared to the industrial/commercial worker scenario SLs to provide a conservative 

assessment of that potential exposure route, as described in Section 6.1.

5 An extra sample was erroneously collected at location AOI01-03 and a third sample was not collected from 

CHAASF-03. 
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Table 5-1. Samples by Medium

Chesterfield Limited AASF, Chesterfield, Virginia

Site Inspection Report

Sample Identification

Sample 

Collection 

Date

Sample Depth

(ft bgs)

PFAS(USEPA Method 537 Modified)TOC(USEPA Method 9060A)pH (USEPA Method 9045D)

Comments

Soil Samples

AOI01-01-SB-01 7/7/21 1 X

AOI01-01-SB-6 7/7/21 6 X X X

AOI01-01-SB-12 7/7/21 12 X

AOI01-02-SB-1 7/7/21 1 X

AOI01-02-SB-8 7/7/21 8 X

AOI01-02-SB-16 7/7/21 16 X

AOI01-03-SB-1 7/7/21 1 X

AOI01-03-SB-7 7/7/21 7 X

AOI01-03-SB-12 7/7/21 12 X

AOI01-03-SB-15 7/7/21 15 X

AOI01-04-SB-1 7/7/21 1 X

AOI01-04-SB-7 7/7/21 7 X

AOI01-04-SB-14 7/7/21 14 X

CHAASF-01-SB-1 7/7/21 1 X

CHAASF-01-SB-6 7/7/21 6 X

CHAASF-01-SB-12 7/7/21 12 X

CHAASF-02-SB-1 7/7/21 1 X

CHAASF-02-SB-6 7/7/21 6 X

CHAASF-02-SB-12 7/7/21 12 X

CHAASF-03-SB-1 7/7/21 1 X

CHAASF-03-SB-9 7/7/21 9 X

CHAASF-FD1-Soil 7/7/21 14 X FD

CHAASF-FD2-Soil 7/7/21 16 X FD

CHAASF-FD3-Soil 7/7/21 12 X FD

Groundwater Samples

AOI01-01-GW 7/7/21 - X

AOI01-02-GW 7/8/21 - X

AOI01-03-GW 7/8/21 - X

AOI01-04-GW 7/7/21 - X

CHAASF-FD1-GW 7/7/21 - X FD

CHAASF-01-GW 7/8/21 - X

CHAASF-02-GW 7/8/21 - X

CHAASF-03-GW 7/7/21 - X

Blank Samples

CHAASF-EB-01 7/7/21 - X EB

CHAASF-FB-01 7/7/21 - X FB

CHAASF-FB-02 7/8/21 - X FB
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Table 5-2. Soil Boring Depths and Temporary Well Screen Intervals

Chesterfield Limited AASF, Chesterfield, Virginia

Site Inspection Report

Area of Interest Boring Location

Soil Boring Depth

(ft bgs)

Temporary Well 

Screen Interval

(ft bgs)

1 

AOI01-01 18 13-18

AOI01-02 19 14-19

AOI01-03 19 14-19

AOI01-04 20 15-20

Chesterfield Limited AASF 

Boundary

CHAASF-01 17.5 12.5-17.5

CHAASF-02 18 13-18

CHAASF-03 20 15-20

Table 5-3. Groundwater Elevation 

Chesterfield Limited AASF, Chesterfield, Virginia

Site Inspection Report

Monitoring Well 

Identification

Top of Casing Elevation

(ft amsl)

Depth to Water

(ft below top of casing)

Groundwater Elevation

(ft amsl)

AOI01-01 206.35 7.5 198.9

AOI01-02 205.15 6.1 199.1

AOI01-03 203.44 3.6 199.8

AOI01-04 204.71 5.5 199.2

CHAASF-01 207.98 9.5 198.5

CHAASF-02 207.55 9.2 198.3

CHAASF-03 205.62 4.7 200.9
Army National Guard Site Inspections

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Chesterfield Limited AASF, Virginia

Figure 5-1

Site Inspection Sample Locations

AOI 1

Building 7417

Building 7431

AOI01-04

AOI01-03

AOI01-02

CHAASF-02

CHAASF-01

CHAASF-03

AOI01-01

Building 7501

3

0 100

Feet

Facility Data

Facility Boundary

Area of Interest

Potential PFAS Release

No Suspected Release

Chesterfield County Airport

Sample Locations

DPT

Hydrology/Hydrogeology

Surface Water Flow Direction

Groundwater Flow Direction

VA ^_

Data Sources:

ESRI 2020

AECOM 2020

Date:....................... April 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N
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6. SITE INSPECTION RESULTS

This section presents the analytical results of the SI for the AOI. The analytical results are 

reported and evaluated in the subsequent sections. The SLs used in this evaluation are presented 

in Section 6.1 and Table 6-1. A discussion of the results for the AOI is provided in Section 6.3. 

Tables 6-2 through 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 SLs established in the OSD memorandum apply to the five compounds presented on 

Table 6-1 below. 

Table 6-1. Screening Levels (Soil and Groundwater)

Analyte

Residential

(Soil)

(μg/kg)

1 

Industrial / Commercial

Composite Worker

(Soil)

(μg/kg)

1 

Tap Water

(Groundwater)

(ng/L)1 

PFOA 19 250 6

PFOS 13 160 4

PFBS 1,900 25,000 601

PFHxS 130 1,600 39

PFNA 19 250 6

Notes:

1. Assistant Secretary of Defense. 2022. Risk-Based SLs in Groundwater and Soil using

EPA’s Regional Screening Level Calculator. Hazard Quotient=0.1. 6 July 2022.

2. Of the six PFAS compounds presented in the 6 July 2022 OSD memorandum, HFPO-DA

(commonly referred to as GenX) was not included as an analyte at the time of this SI.

Based on the CSM developed during the PA and revised based on SI findings, the

presence of HFPO-DA is not anticipated at the facility because HFPO-DA is generally

not a component of MIL-SPEC AFFF and based on its history including distribution

limitations that restricted use of GenX, it is generally not a component of other products

the military used. In addition, it is unlikely that GenX would be an individual chemical of

concern in the absence of other PFAS.

μg/kg = Microgram(s) per kilogram

ng/L = Nanogram(s) per liter

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 

ft bgs) and the industrial/commercial worker scenario is applied to shallow subsurface soil 

results (2 to 15 ft bgs). However, as discussed in the SI QAPP Addendum deviation in Section 

5.8, the industrial/commercial worker scenario was also applied to deep subsurface soil samples 

collected from the soil borings (12 to 16 ft bgs) in AOI 1, providing a conservative assessment of 

that potential exposure route for the industrial/commercial workers. 
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6.2 SOIL PHYSIOCHEMICAL 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). 

Soil pH was measured as 4.9 in a sample collected from AOI 1. TOC was 200 milligrams per 

kilograms in the sample collected from AOI 1.

6.3 AOI 1

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

AOI 1 - Building 7431. The detected compounds are summarized in Tables 6-2 through 6-5. 

Soil and groundwater results are presented on Figures 6-1 through 6-7

6.3.1 AOI 1 – Soil Analytical Results

Tables 6-2 through 6-4 summarize the detected compounds in soil. Figures 6-1 through 6-5

present the ranges of detections in soil. 

Soil was sampled in 4 boring locations associated with one potential release area at AOI 1. Soil 

was sampled from three intervals at all locations. 

PFOA was detected in the surface interval (1−2 ft bgs) of boring location AOI01-01 at a 

concentration of 0.39 J+ μg/kg, which is below the associated SL of 130.0 μg/kg. PFOS, PFHxS, 

PFNA, and PFBS were not detected in the surface interval at any boring locations associated 

with AOI 1. Additionally, there were no detections of PFOA, PFOS, PFHxS, PFNA, and PFBS 

in any of the subsurface soil intervals associated with AOI 1. 
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6.3.2 AOI 1 – Groundwater Analytical Results 

Figure 6-6 and Figure 6-7 present the ranges of detections in groundwater. Table 6-5 

summarizes the groundwater results. 

Groundwater samples were collected from four temporary wells surrounding AOI 1 during the 

SI. PFOS, PFOA, PFHxS, and PFBS were detected in groundwater samples collected from AOI 

1. PFOA was detected in all four temporary wells with values ranging from 1.8 J ng/L

(AOI01-04) to 7 J ng/L (AOI01-02). One detection of PFOA (7 ng/L) in a sample collected from

AOI01-02 exceeded the associated SL of 6 ng/L. Detections of PFOS in all four wells exceeded

the associated SL of 4 ng/L. PFOS was detected with values ranging from 4.7 J ng/L (AOI01-04)

to 35 J ng/L (AOI01-02). PFBS was detected in all four temporary wells below the SL with

values ranging from 2.5 J ng/L (AOI01-01 and AOI01-02) to 7.0 J ng/L (AOI01-03). PFHxS was

detected in all four temporary wells below the SL with values ranging from 16 J ng/L (AOI01-

04) to 30.0 J ng/L (AOI01-03). PFNA was not detected in samples collected from any of the

wells.

6.3.3 AOI 1 – Conclusions

Based on the results of the SI, PFOA and PFOS were detected in groundwater at concentrations 

above their respective SLs. Based on the exceedances of the SLs in groundwater, further 

evaluation at AOI 1 is warranted.

6.4 FACILITY BOUNDARY LOCATIONS

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

samples collected at the upgradient and downgradient facility boundary. The detected 

compounds are summarized in Tables 6-2 through 6-5. Soil and groundwater results are 

presented in Figures 6-1 through 6-7.

6.4.1 Facility Boundary Locations – Soil Analytical Results

Tables 6-2 through 6-4 summarize the detected compounds in soil. Figures 6-1 through 6-5

present the ranges of detections in soil.

Soil was sampled in three boring locations associated with the facility boundary during the SI. 

Soil was sampled from three intervals at all locations, with the exception of CHAASF-03, where 

only two samples were collected as noted in Section 5.8. 

PFOA was detected in the surface interval (1−2 ft bgs) of boring locations CHAASF-01 and 

CHAASF-03 with a maximum concentration of 0.64 J μg/kg at boring location CHAASF-01. 

PFOS was detected in the surface interval of boring locations CHAASF-01, CHAASF-02, and 

CHAASF-03 with a maximum concentration of 1.6 J μg/kg at boring location CHAASF-03. 

PFOA and PFOS detections were well below associated SLs of 19 μg/kg and 13 μg/kg, 

respectively. PFBS and PFHxS were detected in the surface interval of boring location 

CHAASF-01 at concentrations of 2.8 μg/kg and 0.94 μg/kg, which are well below associated SLs 
Site Inspection Report

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of 1900 μg/kg and 130 μg/kg, respectively. There were no detections of PFOS, PFOS, PFHxS,

PFNA, or PFBS in any of the subsurface soil intervals associated with the boring locations along 

the facility boundary. 

6.4.2 Facility Boundary Locations – Groundwater Analytical Results 

Figure 6-6 and Figure 6-7 present the ranges of detections in groundwater. Table 6-5 

summarizes the groundwater results. 

Groundwater samples were collected from three temporary wells associated with the facility 

boundary during the SI. PFOA was detected in groundwater at temporary well location 

CHAASF-01 at a concentration of 58. J ng/L, which exceeds the SL of 6 ng/L. PFOA was also 

detected in CHAASF-02 (5.3 J ng/L) and CHAASF-03 (2.6 J ng/L) at values below the OSD SL 

of 6 ng/L. PFOS was detected in all three temporary well locations. Two of the detections, 4.6 J 

ng/L (CHAASF-03) and 18 J ng/L (CHAASF-02), exceeded the associated SL of 4 ng/L. PFHxS 

was detected in all three temporary boundary wells. One of the detections, 71 J ng/L (CHAASF01), exceeded the associated SL of 39 ng/L. PFBS was detected in all three locations with values 

ranging from 0.69 J ng/L (CHAASF-03) to 290.0 J ng/L (CHAASF-01). PFBS detections were 

below the associated OSD SL of 601 ng/L. PFNA was not detected in any groundwater samples. 

6.4.3 Facility Boundary Locations – Conclusions

PFOA, PFOS, and PFHxS were detected in groundwater at concentrations above their respective 

SLs. Based on the exceedances of the SLs in groundwater, further evaluation of the facility 

boundary is warranted. 
Site Inspection Report

Chesterfield Limited Army Aviation Support Facility, Virginia 

Analyte Screening Level1,2 Result Qual Result Qual Result Qual Result Q

PFAS(E537M) (μg/kg)

Perfluorobutanesulfonic acid (PFBS) 1,900 ND UJ ND UJ ND UJ ND U

Perfluorohexanesulfonic acid 130 ND UJ ND UJ ND UJ ND UPerfluorononanoic acid 19 ND UJ ND UJ ND UJ ND UPerfluorooctanesulfonic acid (PFOS) 13 ND UJ ND UJ ND UJ ND U

Perfluorooctanoic acid (PFOA) 19 0.39 J+ ND UJ ND UJ ND U

Notes:

J = Estimated concentration.J+ = Estimated concentration, biased high.UJ = Analyte was not detected and was reported less than LOD. Associated numerical value is approximate.μg/kg = Microgram(s) per kilogram

1. The Screening Levels for soil are based on incidentalingestion of soil in a residential scenario.

2. Assistant Secretary of Defense. 2022. Risk-BasedScreening Levels in Groundwater and Soil using EPA’sRegional Screening Level Calculator. Hazard Quotient

(HQ)=0.1. July 2022.

Screening values for HFPO-DA were established after SI planning and execution and thus not included as an analyte. Future CERCLA phases will include HFPO-DA if warrantedft bgs = Feet below ground surface.Qual = Qualifier.

ND = Analyte not detected above the LOD.

Table 6-2. PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Surface So

Site Inspection Report, Chesterfield

7/7/2021 7/7/2021 7/7/2021 7/7/2021

Sample Name

Location ID

Depth (ft bgs)

Parent Sample ID

Sample Date

0-1 0-1 0-1 0-1 

AOI01-01-SB-01 AOI01-02-SB-1 AOI01-03-SB-1 AOI01-04-SB

AOI01-01 AOI01-02 AOI01-03 AOI01-04 

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Analyte Screening Level1,2 Result Qual Result Qual Result Qual Result Qual Resu

PFAS (E537M) (μg/kg)Perfluorobutanesulfonic acid (PFBS) 25000 ND UJ ND UJ ND UJ ND UJ ND Perfluorohexanesulfonic acid 1600 ND UJ ND UJ ND UJ ND UJ ND Perfluorononanoic acid 250 ND UJ ND UJ ND UJ ND UJ ND 

Perfluorooctanesulfonic acid (PFOS) 160 ND UJ ND UJ ND UJ ND UJ ND 

Perfluorooctanoic acid (PFOA) 250 ND UJ ND UJ ND UJ ND UJ ND 

Notes:UJ = Analyte was not detected and was reported less than LOD. Associated numerical value is approximate.

μg/kg = Microgram(s) per kilogram.1. The Screening Levels for soil are based onincidental ingestion of soil in aindustrial/commercial worker scenario.2. Assistant Secretary of Defense. 2022. Risk-BasedScreening Levels in Groundwater and Soil usingEPA’s Regional Screening Level Calculator. Hazard

Quotient (HQ)=0.1. July 2022.

Screening values for HFPO-DA were establishedafter SI planning and execution and thus notincluded as an analyte. Future CERCLA phases willinclude HFPO-DA if warrantedft bgs = Feet below ground surface.Qual = Qualifier.ND = Analyte not detected above the LOD.

Table 6-3.

PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Shallow Subsurface S

Site Inspection Report, Chesterfield

Sample Date

Location ID

Sample Name

AOI01-01 AOI01-02

Parent Sample ID

Depth (ft bgs)

7/7/2021 7/7/2021

AOI01-03 AOI01-03

7/7/2021 7/7/2021

5-6 7-8 11-12 6-7

AOI01-01-SB-06 AOI01-02-SB-8 AOI01-03-SB-12 AOI01-03-SB-7

7

A

AOI

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Location ID

Sample Name

Parent Sample ID

Depth (ft bgs)

Sample Date

Analyte Result Qual Result Qual Result Qual Result Qual Result Qual 

PFAS(E537M) (μg/kg)Perfluorobutanesulfonic acid (PFBS) ND UJ ND UJ ND UJ ND UJ ND UJ Perfluorohexanesulfonic acid ND UJ ND UJ ND UJ ND UJ ND UJ Perfluorononanoic acid ND UJ ND UJ ND UJ ND UJ ND UJ Perfluorooctanesulfonic acid (PFOS) ND UJ ND UJ ND UJ ND UJ ND UJ Perfluorooctanoic acid (PFOA) ND UJ ND UJ ND UJ ND UJ ND UJ Notes:UJ = Analyte was not detected and was reported less than LOD. Associated numerical value is approximate.

Screening values for HFPO-DA were established after SI planning and execution and thus not included as an analyte. Future CERCLA phases will include HFPO-DA if warrantedμg/kg = Microgram(s) per kilogram.ft bgs = Feet below ground surface.Qual = Qualifier.ND = Analyte not detected above the LOD.

Table 6-4. PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Deep Subsurfa

Site Inspection Report, Chesterfield

AOI01-02 AOI01-02

AOI01-02-SB-16

7/7/2021 7/7/2021 7/7/2021 7/7/2021 7/7/2021

AOI01-01-SB-12 AOI01-02-SB-16 CHAASF-FD2-Soil AOI01-03-SB-15 AOI01-04-SB-14 C

AOI01-01 AOI01-03 AOI01-04 

11-12 15-16 15-16 14-15 13-14

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Analyte Screening Level 1 Result Qual Result Qual Result Qual Result Qual Resu

PFAS(E537M) (ng/L)Perfluorobutanesulfonic acid (PFBS) 601 2.5 J 2.5 J 7 J 4.9 J 5.6 Perfluorohexanesulfonic acid 39 16 J 16 J 30 J 16 J 20 

Perfluorononanoic acid 6 ND UJ ND UJ ND UJ ND UJ ND 

Perfluorooctanesulfonic acid (PFOS) 4 8.2 J 35 J 5.4 J 4.7 J 5.6 

Perfluorooctanoic acid (PFOA) 6 3.7 J 7 J 2.2 J 1.8 J 2.2 Notes:J = Estimated concentration.UJ = Analyte was not detected and was reported less than LOD. Associated numerical value is approximate.ng/L = Nanogram(s) per liter.1. Assistant Secretary of Defense. 2022. Risk-BasedScreening Levels in Groundwater and Soil usingEPA’s Regional Screening Level Calculator. Hazard

Quotient (HQ)=0.1. July 2022.

Screening values for HFPO-DA were established after SI planning and execution and thus not included as an analyte. Future CERCLA phases will include HFPODA if warranted.Values exceeding the Screening Level are shaded gray.ND = Analyte not detected above the LOD.Qual = Qualifier.

Table 6-5. PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Groundwat

Site Inspection Report, Chesterfield

AOI01-01 AOI01-02 AOI01-03 AOI01-04

Sample Date

Sample Name

Location ID

Parent Sample ID

7/7/2021

AOI01-01-GW AOI01-02-GW AOI01-03-GW AOI01-04-GW CHAA

A

AO

7/8/2021 7/8/2021 7/7/2021 

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Figure 6-1

PFOS Detections in Soil (AOI 1)

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

3

0 200

Feet

Facility Data

Facility Boundary

Area of Interest

Potential PFAS Release

No Suspected Release

Chesterfield County Airport

Hydrology/Hydrogeology

Surface Water Flow Direction

Groundwater Flow Direction

VA ^_

Data Sources:

ESRI 2020

AECOM 2020

Date:....................... April 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N

0 200

Feet

0 200

Feet

Shallow Intermediate Deep

> 1,600

> 160 - 1,600

> 13 - 160

> ND - 13

ND (Non-Detect)

PFOS Results (μg/Kg)

> 1,600

> 160 - 1,600

> 13 - 160

> ND - 13

ND (Non-Detect)

PFOS Results (μg/Kg)

> 1,600

> 160 - 1,600

> 13 - 160

> ND - 13

ND (Non-Detect)

PFOS Results (μg/Kg)

Notes:

PFOS = Perfluorooctanesulfonic acid

Exceedances of the OSD SL are depicted

with a yellow halo. Depth intervals shown

represent respective sampling position

within a given soil boring location.
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Figure 6-2

PFOA Detections in Soil (AOI 1)

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

3

0 200

Feet

Facility Data

Facility Boundary

Area of Interest

Potential PFAS Release

No Suspected Release

Chesterfield County Airport

Hydrology/Hydrogeology

Surface Water Flow Direction

Groundwater Flow Direction

VA ^_

Data Sources:

ESRI 2020

AECOM 2020

0 200

Feet

0 200

Feet

Shallow Intermediate Deep

Date:...................... April 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N

> 2,500

> 250 - 2,500

> 19 - 250

> ND - 19

ND (Non-Detect)

PFOA Results (μg/Kg)

> 2,500

> 250- 2,500

> 19 - 250

> ND - 19

ND (Non-Detect)

PFOA Results (μg/Kg)

> 2,500

> 250- 2,500

> 19 - 250

> ND - 19

ND (Non-Detect)

PFOA Results (μg/Kg)

Notes:

PFOA = Perfluorooctanoic acid

Exceedances of the OSD SL are depicted

with a yellow halo. Depth intervals shown

represent respective sampling position

within a given soil boring location.
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Figure 6-3

PFBS Detections in Soil (AOI 1)

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

3

0 200

Feet

Facility Data

Facility Boundary

Area of Interest

Potential PFAS Release

No Suspected Release

Chesterfield County Airport

Hydrology/Hydrogeology

Surface Water Flow Direction

Groundwater Flow Direction

VA ^_

Data Sources:

ESRI 2020

AECOM 2020

0 200

Feet

0 200

Feet

Shallow Intermediate Deep

Date:....................... April 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N

Notes:

PFBS = Perfluorobutanesulfonic acid

Exceedances of the OSD SL are depicted

with a yellow halo. Depth intervals shown

represent respective sampling position

within a given soil boring location.

> 25,000

> 1,900 - 25,000

> 10 - 1,900

> ND - 10

ND (Non-Detect)

PFBS Results (μg/Kg)

> 25,000

> 1,900 - 25,000

> 10 - 1,900

> ND - 10

ND (Non-Detect)

PFBS Results (μg/Kg)

> 25,000

> 1,900 - 25,000

> 10 - 1,900

> ND - 10

ND (Non-Detect)

PFBS Results (μg/Kg)
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Figure 6-4

PFHxS Detections in Soil (AOI 1)

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

3

0 200

Feet

Facility Data

Facility Boundary

Area of Interest

Potential PFAS Release

No Suspected Release

Chesterfield County Airport

Hydrology/Hydrogeology

Surface Water Flow Direction

Groundwater Flow Direction

VA ^_

Data Sources:

ESRI 2020

AECOM 2020

0 200

Feet

0 200

Feet

Shallow Intermediate Deep

Date:....................... April 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N

Notes:

PFHxS = Perfluorohexanesulfonic acid

Exceedances of the OSD SL are depicted

with a yellow halo. Depth intervals shown

represent respective sampling position

within a given soil boring location.

> 1,600

> 130 - 1,600

> 10 - 130

> ND - 10

ND (Non-Detect)

PFHxS Result (μg/Kg)

> 1,600

> 130 - 1,600

> 10 - 130

> ND - 10

ND (Non-Detect)

PFHxS Result (μg/Kg)

> 1,600

> 130 - 1,600

> 10 - 130

> ND - 10

ND (Non-Detect)

PFHxS Result (μg/Kg)
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Figure 6-5

PFNA Detections in Soil (AOI 1)

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

3

0 200

Feet

Facility Data

Facility Boundary

Area of Interest

Potential PFAS Release

No Suspected Release

Chesterfield County Airport

Hydrology/Hydrogeology

Surface Water Flow Direction

Groundwater Flow Direction

VA ^_

Data Sources:

ESRI 2020

AECOM 2020

0 200

Feet

0 200

Feet

Shallow Intermediate Deep

Date:....................... April 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N

Notes:

PFNA = Perfluorononanoic acid

Exceedances of the OSD SL are depicted

with a yellow halo. Depth intervals shown

represent respective sampling position

within a given soil boring location.

> 2,500

> 250 - 2,500

> 19 - 250

> ND - 19

ND (Non-Detect)

PFNA Results (μg/Kg)

> 2 ,500

> 250 - 2,500

> 19 - 250

> ND - 19

ND (Non-Detect)

PFNA Results (μg/Kg)

> 2 ,500

> 250 - 2,500

> 19 - 250

> ND - 19

ND (Non-Detect)

PFNA Results (μg/Kg)
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Army National Guard Site Inspections

Site Inspection Report

Chesterfield Limited AASF, Virginia

Figure 6-6

PFOS, PFOA and PFBS Detections in Groundwater (AOI 1)

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

3

0 200

Feet

Facility Data

Facility Boundary

Area of Interest

Potential PFAS Release

No Suspected Release

Chesterfield County Airport

Hydrology/Hydrogeology

Surface Water Flow Direction

Groundwater Flow Direction

VA ^_

Data Sources:

ESRI 2020

AECOM 2020

0 200

Feet

PFOA PFOS

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02 Building 7431

Building 7417

AOI 1

0 200

Feet

PFBS

Date:...................... April 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N

> 70

> 40 - 70

> 6 - 40

> ND - 6

ND (Non-Detect)

PFOA Results (ng/L)

> 70

> 40 - 70

> 4 - 40

> ND - 4

ND (Non-Detect)

PFOS Results (ng/L)

> 1,000

> 601 - 1,000

> 100 - 601

> ND - 100

ND (Non-Detect)

PFBS Results (ng/L)

Notes:

PFOA = Perfluorooctanesulfonic acid

PFOS = Perfluorooctanoic acid

PFBS = Perfluorobutanesulfonic acid

Exceedances of the OSD SL are depicted

with a yellow halo.
Site Inspection Report

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Figure 6-7

PFHxS and PFNA Detections in Groundwater (AOI 1)

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02

Building 7431

Building 7417

AOI 1

AOI1-01 AOI01-04

AOI01-03

CHAASF-03

CHAASF-02

CHAASF-01

AOI01-02

Building 7431

Building 7417

AOI 1

3

0 200

Feet

Facility Data

Facility Boundary

Area of Interest

Potential PFAS Release

No Suspected Release

Chesterfield County Airport

Hydrology/Hydrogeology

Surface Water Flow Direction

Groundwater Flow Direction

VA ^_

0 200

Feet

PFHxS PFNA

Notes:

PFHxS = Perfluorohexanesulfonic acid

PFNA = Perfluorononanoic acid

Exceedances of the OSD SL are depicted

with a yellow halo.

> 1,000

> 100 - 1,000

> 39 - 100

> ND - 39

ND (Non-Detect)

PFHxS Result (ng/L)

> 1,000

> 100 - 1,000

> 6 - 100

> ND - 6

ND (Non-Detect)

PFNA Results (ng/L)

Army National Guard Site Inspections

Site Inspection Report

Chesterfield Limited AASF, Virginia

Data Sources:

ESRI 2020

AECOM 2020

Date:...................... April 2023

Prepared By:.............................EA

Prepared For:....................USACE

Projection:........WGS 84 UTM 18N
Site Inspection Report

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7. EXPOSURE PATHWAYS

The conceptual site model (CSM) for the AOI, based on the SI findings, is presented on Figure 

7-1. Please note that while the CSM discussion assists in determining if a receptor may be

impacted, the decision to move from SI to RI or interim action is determined solely based upon

exceedances of the SLs for the relevant compounds and whether the release is more than likely

attributable to the DoD. 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. SLs are presented in Section 6.1

of this report.

1. Contaminant source

2. Environmental fate and transport

3. Exposure point

4. Exposure route

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 no identified complete 

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 and a complete pathway may warrant further investigation. 

In general, the potential relevant compounds exposure pathways 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 facility workers (e.g., facility staff and visiting soldiers), construction 

workers, trespassers, residents outside the facility boundary, and recreational users outside of the 

facility boundary. The CSM for AOI 1, revised based on the SI findings, is presented on Figure 

7-1.

7.1 SOIL EXPOSURE PATHWAY

The SI results for soil were used to determine whether a potentially complete pathway exists 

between the source and potential receptors at AOI 1 based on the aforementioned criteria. 

7.1.1 AOI 1 – Building 7431 

AOI 1 includes Building 7431 where a Tri-MaxTM fire extinguisher filled with unknown contents 

was observed outside of the southern corner of the building during the PA site visit. No soil 

borings near the Tri-MaxTM fire extinguisher location had detections of relevant compounds. 
Site Inspection Report

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PFOA was detected in surface soil at location AOI01-01 at a concentration below the associated 

screening level. Based on the results of the SI at AOI 1, ground-disturbing activities to surface 

soil may result in site worker and construction worker exposure to PFOA via inhalation of dust 

or incidental ingestion of surface soil. The facility is within a 1-mile radius of residential areas, 

so nearby off-facility residents and trespassers may also be exposed to airborne soil particles 

resulting from ground- disturbing activities. None of the relevant compounds were detected in 

subsurface soils. As such, ground-disturbing activities to subsurface soil would not result in 

construction worker exposure to relevant compounds via ingestion. The exposure pathways for 

inhalation are potentially complete for site and construction workers, residents and 

trespassers/recreational users. The CSM is presented in Figure 7-1. 

7.2 GROUNDWATER EXPOSURE PATHWAY

The SI results for groundwater were used to determine whether a potentially complete pathway 

exists between the source and potential receptors at AOI 1 based on the aforementioned criteria. 

7.2.1 AOI 1 − Building 7431 

PFOA, PFOS, PFHxS, and PFBS were detected in groundwater from the temporary wells 

associated with AOI 1. PFOS and PFOA were detected at concentrations that exceeded 

associated SLs. PFHxS was also detected in groundwater above the SL in a facility boundary 

location. Due to the existence of multiple domestic and public groundwater wells in the 

surrounding area of the facility, off-facility residents may be potentially exposed to groundwater 

via ingestion. Based on this information, the ingestion exposure pathway is potentially complete 

for construction workers (via incidental ingestion) during subsurface work activities. The

ingestion exposure pathway for site workers is incomplete, as drinking water for the Facility is 

provided by an upgradient surface water source (not provided by downgradient groundwater). 

The CSM is presented in Figure 7-1. 

7.3 SURFACE WATER AND SEDIMENT EXPOSURE PATHWAYS

Based on available information, potential AFFF releases may be drained to Outfall #2, which

receives runoff from the runway, parking lots, apron, and hangar buildings, and directly 

discharges into Reedy Creek, a tributary of the James River. Off-facility receptors such as 

residents and recreational users may be exposed to relevant compounds via ingestion of surface 

water and sediment in the James River and its tributaries, or via the ingestion of fish 

contaminated with relevant compounds (AECOM 2020). Surface water and sediment were not 

included in the scope for this SI; therefore, sampling of these media was not conducted. As such, 

the exposure pathways via the ingestion of surface water and sediment are considered potentially 

complete. 
Notes:

1. The resident and recreational users refer to

off-site receptors.

2. Inhalation of dust for off-site receptors is

likely insignificant.

3. Human consumption of fish potentially

affected by PFAS is possible.

Figure 7-1

Conceptual Site Model, AOI 1 

Chesterfield Limited AASF, VA

RECEPTOR

Human Receptors:

Current/Future

Site 

Worker

Construction 

Worker Resident1,2 Trespasser/ 

Recreational User1,3

Site 

Worker

Construction 

Worker

AOI 1

PFAS in 

Surface Soil/

Surface 

Water

Human 

Activities

Precipitation/

Run-Off

Leaching/

Infiltration

Airborne 

Soil 

Particulate

Surface Soil 

at AOI

Surface 

Water/ 

Sediment

Subsurface 

Soil

Groundwater

Ingestion

Ingestion

Ingestion

Ingestion

Potential 

Off-Facility 

Source Not 

Under 

Control of 

ARNG

Potential AFFF 

release from the 

Tri-MaxTM fire 

extinguisher

SOURCE

Source Release 

Mechanism Media

PATHWAY

Transport

and Migration Media Exposure 

Routes

Inhalation 

of Dust

Trespasser/ 

Recreational User Resident 1,3

1,2

Potentially Complete Pathway with Exceedance of 

Screening Level
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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 SITE INSPECTION ACTIVITIES SUMMARY

The SI field activities at the facility were conducted from 6 to 8 July 2021. The SI field activities 

included soil and groundwater sampling. Field activities were conducted in accordance with the 

UFP-QAPP Addendum (EA 2021a), except as previously noted in Section 5.8. 

To fulfill the project DQOs set forth in the approved SI UFP-QAPP Addendum (EA 2021a), 

samples were collected and analyzed for a subset of 24 compounds by LC/MS/MS compliant 

with QSM Version 5.3 Table B-15 as follows: 

• Twenty-one soil (21) samples from seven locations (soil borings locations)

• Seven (7) grab groundwater samples from seven temporary well locations

• Nine (9) quality assurance/quality control samples.

An SI is conducted when the PA determines an AOI exists based on probable use, storage, and/or 

disposal of PFAS-containing materials. The SI includes multi-media sampling at the AOI to 

determine whether or not a release has occurred. The SI may conclude further investigation is 

warranted, a removal action is required to address immediate threats, or no further action is 

required. Additionally, the CSM was refined to assess whether a potentially complete pathway 

exists between the source and potential receptors for potential exposure at the AOI, described in 

Section 7. 

8.2 OUTCOME

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

Based on the CSM developed and revised based on the SI findings, there is potential for 

exposure to drinking water receptors from releases during historical DoD activities at the Site, 

and potentially from off-facility sources. Sample chemical analytical concentrations collected 

during this SI were compared against the project SLs in soil and groundwater, as described in 

Table 6-1. A summary of the results of the SI data relative to SLs is as follows:

• AOI 1:

 PFBS and PFHxS were not detected in groundwater at concentrations exceeding

associated SLs and PFNA was not detected. Detections of PFOS from all wells, 

ranging from 4.7 J ng/L to 35 J ng/L, exceeded the associated SL (4.0 ng/L). PFOA 

was detected in well AOI01-02 at a concentration (7.0 J ng/L) that exceeded the 

associated SL (6.0 ng/L). Based on the results of the SI, further evaluation of AOI 1 is 

warranted in the RI.
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 PFOA was detected in soil in one out of four borings associated with AOI 1 at a low 

concentration, several orders of magnitude below the SL. PFOS, PFHxS, PFNA, and 

PFBS were not detected in soil at AOI 1.

• At the boundary:

 The groundwater sample taken from CHAASF-01, located at the northwestern facility

boundary and downgradient of AOI 1, exceeded SLs for PFOA and PFHxS. 

Additionally, two detections of PFOS, 4.6 J ng/L (CHAASF-03) and 18 J ng/L 

(CHAASF-02), exceeded the associated SL of 4 ng/L. CHAASF-02 is downgradient 

of AOI-01 and CHAASF-03 is upgradient of AOI-01. PFBS was detected in all three 

boundary locations with values ranging from 0.69 J ng/L (CHAASF-03) to 290.0 J 

ng/L (CHAASF-01). PFBS detections were below the associated OSD SL of 601 

ng/L. PFNA was not detected in any boundary samples. Based on the results of the SI 

further evaluation of the boundary is warranted. 

 All detections of PFOA, PFOS, PFHxS, PFNA, and PFBS in soil at the facility 

boundary locations were below associated SLs. 

Of the six PFAS compounds presented in the 6 July 2022 OSD memorandum, HFPO-DA 

(commonly referred to as GenX) was not included as an analyte at the time of this SI. Based on 

the CSM developed during the PA and revised based on SI findings, the presence of HFPO-DA 

is not anticipated at the facility because HFPO-DA is generally not a component of MIL-SPEC 

AFFF and based on its history including distribution limitations that restricted use of GenX, it is 

generally not a component of other products the military used. In addition, it is unlikely that 

GenX would be an individual chemical of concern in the absence of other PFAS. 

Table 8-1 summarizes the SI results for soil and groundwater used to determine if an AOI should 

be considered for further investigation under CERCLA and undergo an RI. 

Table 8-1. Summary of Site Inspection Findings and Recommendations

AOI

Potential PFAS 

Release Area

Soil –

Source Area

Groundwater –

Source Area

Groundwater –

Facility Boundary Future Action

1 Building 7431 Proceed to RI

Legend:

= Detected; exceedance of SLs 

= Detected; no exceedance of SLs 

= Not detected
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9. REFERENCES

AECOM Technical Services, Inc. (AECOM). 2020. Final Preliminary Assessment Report, 

Chesterfield Limited Army Aviation Support Facility (AASF), Virginia, Virginia Army 

National Guard. July.

Department of the Army. 2016a. EM-200-1-2, Environmental Quality, Technical Project 

Planning process. 29 February. 

. 2018. Army Guidance for Addressing Releases of Per-and Polyfluoroalkyl Substances. 

September.

Department of Defense (DoD). 2019. General Data Validation Guidelines. November.

. 2020. Data Validation Guidelines Module 3: Data Validation Procedure for Per- and 

Polyfluoroalkyl Substances Analysis by QSM Table B-15. May.

EA Engineering, Science, and Technology, Inc. PBC (EA). 2020a. Final Programmatic Uniform 

Federal Policy Quality Assurance Project Plan, Site Inspections for Per- and Polyfluoroalkyl 

Substances Impacted Sites, ARNG Installations, Nationwide. December.

. 2020b. Accident Prevention Plan, Programmatic Uniform Federal Policy Quality 

Assurance Project Plan, Site Inspections for Per- and Polyfluoroalkyl Substances impacted 

Sites, ARNG Installations, Nationwide. November.

. 2021a. Final Site Inspection Uniform Federal Policy Quality Assurance Project Plan 

(UFP-QAPP) Addendum, Chesterfield Limited Army Aviation Support Facility, Chesterfield, 

Virginia, Per- and Polyfluoroalkyl Substances Impacted Sites ARNG Installations, 

Nationwide. June.

.2021b. Final Accident Prevention Plan / Site Safety and Health Plan Addendum, 

Chesterfield Limited Army Aviation Support Facility, Virginia, Revision 1. February. 

Guelfo, J.L. and C.P. Higgins. 2013. Subsurface transport potential of perfluoroalkyl acids and 

aqueous film-forming foam (AFFF)-impacted sites. Environ. Sci. Technol. 47(9):4164−71. 

Higgins, C.P. and R.G. Luthy. 2006. Sorption of perfluorinated surfactants on sediments. 

Environ. Sci. Technol. 40 (23): 7251−7256. 

Interstate Technology Regulatory Council (ITRC). 2018. Environmental Fate and Transport for 

Per- and Polyfluoroalkyl Substances. March. 

Office of the Assistant Secretary of Defense. 2021. Investigation Per- and Polyfluoroalkyl 

Substances within The Department of Defense Cleanup Program. U.S. Department of 

Defense. 15 September.
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Chesterfield Limited Army Aviation Support Facility, Virginia Version: FINAL

EA Engineering, Science, and Technology, Inc., PBC 9-2

U.S. Environmental Protection Agency (USEPA). 1980. Comprehensive Environmental

Response, Compensation, and Liability Act (CERCLA). 11 December.

. 1994. National Oil and Hazardous Substances Pollution Contingency Plan (Final Rule).

40 Code of Federal Regulations Part 300; 59 Federal Register 47384. September.

. 2001. EPA Requirements for Quality Assurance Project Plans, EPA QA/R-5.

EPA/240/B-01/003. Office of Environmental Information, Washington, D.C. March.

. 2016b. Drinking Water Health Advisory for Perfluorooctane Sulfonate (PFOS). Office 

of Water (4304T). Health and Ecological Criteria Division, Washington, DC 20460. USEPA

Document Number: 822-R-16-004. May.

. 2018. Regional Screening Levels – Generic Tables (November 2018). Residential =m 

Direct Contact Soil. https//www/edpa.gov/ris/regional-screening-levels-rsls-generic-tables. 

November. 

U.S. Fish and Wildlife Service. 2021. Endangered Species. http://ecos.fws.gov/ipac/. Accessed 

on 5 December2021. 

Xiao, F., M.F. Simcik, T.R. Halbach, and J.S. Gulliver, 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.