FINAL

Site Inspection Report

Jefferson City AASF

Jefferson City, Missouri

Site Inspection for Perfluorooctanoic acid (PFOA), 

Perfluorooctanesulfonic acid (PFOS), Perfluorohexanesulfonic 

acid (PFHxS), Perfluorononanoic acid (PFNA), 

Hexafluoropropylene oxide dimer acid (HFPO-DA), and 

Perfluorobutanesulfonic acid (PFBS) at ARNG Installations, 

Nationwide 

July 2023

Prepared for:

Army National Guard Bureau

111 S. George Mason Drive

Arlington, VA 22204

UNCLASSIFIED
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Army Aviation Support Facility, Jefferson City, Missouri

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Table of Contents

Executive Summary ......................................................................................................................1

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

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

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

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

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

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

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

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

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

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

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

3.1 AOI 1 West Ramp Nozzle Testing, Firetruck Storage, AFFF Storage.....................3-1

3.2 AOI 2 Outdoor Wash Rack FTA and GSE Building.................................................3-1

3.3 AOI 3 East Ramp Nozzle Testing............................................................................3-1

3.4 Adjacent Sources....................................................................................................3-1

3.4.1 Jefferson City................................................................................................3-2

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

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

4.2 Information Inputs ...................................................................................................4-1

4.3 Study Boundaries ...................................................................................................4-1

4.4 Analytical Approach ................................................................................................4-1

4.5 Data Usability Assessment .....................................................................................4-2

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

6.3.2 AOI 1 Groundwater Analytical Results .........................................................6-2
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6.3.3 AOI 1 Conclusions........................................................................................6-3

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

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

6.4.2 AOI 2 Groundwater Analytical Results .........................................................6-4

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

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

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

6.5.2 AOI 3 Groundwater Analytical Results .........................................................6-5

6.5.3 AOI 3 Conclusions........................................................................................6-5

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

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

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

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

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

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

7.2.1 AOI 1 ............................................................................................................7-2

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

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

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

7.3.1 AOI 1, AOI 2, and AOI 3 ...............................................................................7-3

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

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

8.2 Outcome .................................................................................................................8-1

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

Appendix A Data Usability Assessment and Validation Reports

Appendix B Field Documentation

B1. Log of Daily Notice of Field Activities

B2. Sampling Forms

B3. Field Change Request Forms and Nonconformance Report

B4. Survey Data

B5. Investigation-Derived Waste Polygons

Appendix C Photographic Log

Appendix D TPP Meeting Minutes

Appendix E Boring Logs

Appendix F Analytical Results

Appendix G Laboratory Reports

Figures

Figure 2-1 Facility Location

Figure 2-2 Facility Topography

Figure 2-3 Groundwater Features

Figure 2-4 Groundwater Elevations, February 2022

Figure 2-5 Surface Water Features

Figure 3-1 Areas of Interest

Figure 5-1 Site Inspection Sample Locations

Figure 6-1 PFOA Detections in Soil

Figure 6-2 PFOS Detections in Soil

Figure 6-3 PFBS Detections in Soil

Figure 6-4 PFHxS Detections in Soil

Figure 6-5 PFNA Detections in Soil

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

Figure 6-7 PFHxS and PFNA Detections in Groundwater

Figure 7-1 Conceptual Site Model, AOI 1

Figure 7-2 Conceptual Site Model, AOI 2

Figure 7-3 Conceptual Site Model, AOI 3

Tables

Table ES-1 Screening Levels (Soil and Groundwater)

Table ES-2 Summary of Site Inspection Findings and Recommendations

Table 5-1 Site Inspection Samples by Medium

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

Elevations

Table 6-1 Screening Levels (Soil and Groundwater)

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

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

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

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

Table 8-1 Summary of Site Inspection Findings and Recommendations
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Acronyms and Abbreviations

% percent

°C degrees Celsius

°F degrees Fahrenheit

μg/kg micrograms per kilogram

AASF Army Aviation Support Facility

AECOM AECOM Technical Services, Inc.

AFFF aqueous film-forming foam

AOI Area of Interest

ARNG Army National Guard

bgs below ground surface 

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act

CoC chain of custody

CSM conceptual site model

DA Department of the Army

DoD Department of Defense

DPT direct push technology

DQO data quality objective

DUA data usability assessment

ELAP Environmental Laboratory Accreditation Program

EM Engineer Manual

FedEx Federal Express

FTA Fire Training Area

GPS Global positioning system

GPRS Ground Penetrating Radar Systems

GSE Ground Service Equipment

HDPE high-density polyethylene

HFPO-DA hexafluoropropylene oxide dimer acid

IDW investigation-derived waste

ITRC Interstate Technology Regulatory Council

LC/MS/MS liquid chromatography with tandem mass spectrometry

MIL-SPEC military specification

MOARNG Missouri Army National Guard

NELAP National Environmental Laboratory Accreditation Program

ng/L nanograms per liter

ORP oxidation-reduction potential

OSD Office of the Secretary of Defense

OWS oil/water separator

PA Preliminary Assessment

PFAS per- and polyfluoroalkyl substances

PFBS perfluorobutanesulfonic acid

PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

PFOA perfluorooctanoic acid
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PFOS perfluorooctanesulfonic acid

PID photoionization detector

PQAPP Programmatic UFP-QAPP

PVC polyvinyl chloride

QA quality assurance

QAPP Quality Assurance Project Plan

QC quality control

QSM Quality Systems Manual

RI Remedial Investigation

SI Site Inspection

SL screening level

SOP standard operating procedure

TOC total organic carbon

TPP Technical Project Planning

UFP Uniform Federal Policy

US United States

USACE United States Army Corps of Engineers

USCS Unified Soil Classification System

USEPA United States Environmental Protection Agency

USFWS United States Fish and Wildlife Service

WWTP wastewater treatment plant
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Army Aviation Support Facility, Jefferson City, Missouri

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Executive Summary

The Army National Guard (ARNG) G-9 is performing Preliminary Assessments (PAs) and Site 

Inspections (SIs) 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) dated 6 July 2022 (Assistant Secretary of Defense, 2022). The six 

compounds listed in the OSD memorandum include perfluorooctanesulfonic acid (PFOS), 

perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid 

(PFHxS), hexafluoropropylene oxide dimer acid (HFPO-DA)1, and perfluorobutanesulfonic acid 

(PFBS). These compounds are collectively referred to as “relevant compounds” throughout the 

document, and the applicable screening levels (SLs) are provided in Table ES-1.

The PA identified three Areas of Interest (AOIs) where PFAS-containing materials may have been 

used, stored, disposed, or released historically (see Table ES-2 for AOI locations). 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 SLs for relevant 

compounds. This SI was completed at the Jefferson City Army Aviation Support Facility (AASF)

in Jefferson City, Missouri and determined further investigation is warranted for AOI 1: West Ramp 

Nozzle Testing, Firetruck Storage, and Aqueous Film Forming Foam (AFFF) Storage; AOI 2: 

Outdoor Wash Rack Fire Training Area (FTA) and Ground Service Equipment (GSE) Building;

and AOI 3: East Ramp Nozzle Testing. The Jefferson City AASF will also be referred to as the 

“facility” throughout this document.

Jefferson City AASF is in Callaway County, central Missouri. The Jefferson City AASF occupies 

17 acres adjacent to the Jefferson City Memorial Airport and is accessible from the north via 

highway US-94 (Bluff Road). The AASF has been operated by the Missouri ARNG (MOARNG)

since 1975. Currently, the facility operates as a military aircraft maintenance facility for the 

MOARNG. The facility includes an aircraft hangar, two petroleum oil and lubricant storage 

buildings, a drive-on secondary containment structure, a wash rack, taxiways, and aircraft parking 

pads (AECOM Technical Services, Inc. [AECOM], 2020).

The PA identified three AOIs for investigation during the SI phase. SI sampling results from the 

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

Based on the results of this SI, further evaluation under CERCLA is warranted in a Remedial 

Investigation for AOI 1: West Ramp Nozzle Testing, Firetruck Storage, and AFFF Storage; AOI 2: 

Outdoor Wash Rack FTA and GSE Building; and AOI 3: East Ramp Nozzle Testing.

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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Army Aviation Support Facility, Jefferson City, Missouri

AECOM ES-2

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

Analyteb

Residential

(Soil)

(μg/kg)a 

0-2 feet bgs

Industrial/ Commercial 

Composite Worker

(Soil)

(μg/kg)a 

2-15 feet bgs

Tap Water

(Groundwater) 

(ng/L)a

PFOA 19 250 6 

PFOS 13 160 4 

PFBS 1,900 25,000 601 

PFHxS 130 1,600 39

PFNA 19 250 6 

Notes:

bgs = below ground surface; μg/kg = micrograms per kilogram; ng/L = nanograms per liter

a.) Assistant Secretary of Defense, 2022. Risk Based Screening Levels in Groundwater and Soil using United States Environmental Protection 

Agency’s (USEPA’s) Regional Screening Level Calculator. Hazard Quotient (HQ) = 0.1. 6 July 2022. 

b.) 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 HFPODA 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 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 

West Ramp 

Nozzle Testing, 

Firetruck 

Storage, and 

AFFF Storage

Proceed 

to RI

2 

Outdoor Wash 

Rack FTA and 

GSE Building

Proceed 

to RI 

3 East Ramp 

Nozzle Testing

Proceed 

to RI 

Legend:

= detected; exceedance of the screening levels

= detected; no exceedance of the screening levels

= not detected
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Army Aviation Support Facility, Jefferson City, Missouri

AECOM 1-1

1. Introduction

1.1 Project Authorization 

The Army National Guard (ARNG) G-9 is the lead agency in performing Preliminary Assessments 

(PAs) and Site Inspections (SIs) 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) dated 6 July 2022 (Assistant 

Secretary of Defense, 2022). The six compounds listed in the OSD memorandum will be referred 

to as “relevant compounds” throughout this document and include perfluorooctanoic acid (PFOA), 

perfluorooctanesulfonic acid (PFOS), perfluorohexanesulfonic acid (PFHxS), perfluorononanoic 

acid (PFNA), hexafluoropropylene oxide dimer acid (HFPO-DA)1, and perfluorobutanesulfonic 

acid (PFBS) at ARNG facilities nationwide. The ARNG performed this SI at the Jefferson City 

Army Aviation Support Facility (AASF) in Jefferson City, Missouri. The Jefferson City AASF is also

referred to as the “facility” throughout this document.

The SI project elements were performed in compliance with the Comprehensive Environmental 

Response, Compensation, and Liability Act (CERCLA; United States [US] Environmental 

Protection Agency [USEPA], 1980), as amended, the National Oil and Hazardous Substances 

Pollution Contingency Plan (40 Code of Federal Regulations Part 300; USEPA, 1994), and in 

compliance with US Department of the Army (DA) requirements and guidance for field 

investigations.

1.2 SI Purpose

A PA was performed at Jefferson City AASF (AECOM Technical Services, Inc. [AECOM], 2020) 

that identified three Areas of Interest (AOIs) where PFAS-containing materials may have been 

used, stored, disposed, or released historically. 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 screening levels (SLs) for the relevant compounds. 

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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2. Facility Background

2.1 Facility Location and Description

Jefferson City AASF is in Callaway County, central Missouri (Figure 2-1). The AASF is 

approximately 1.5 miles from the city center of Jefferson City and is approximately 100 miles west 

of St. Louis, Missouri. The AASF is adjacent to the Jefferson City Memorial Airport and is 

accessible from the north via highway US-94 (Bluff Road). The facility currently operates as a 

military aircraft maintenance facility for the Missouri ARNG (MOARNG). The major facility features 

consist of an aircraft hangar, two petroleum oil and lubricant storage buildings, a drive-on 

secondary containment structure, a wash rack, taxiways, and aircraft parking pads.

The AASF is constructed on an approximately 17-acre parcel of land that has been operated by 

the MOARNG since 1975. The land is owned by the City of Jefferson and leased to the State of 

Missouri Office of the Adjutant General for the construction of the MOARNG AASF. The term of 

the lease is for an indefinite time and began in 1975. The AASF includes hangars, storage 

buildings, and administrative offices.

2.2 Facility Environmental Setting

Jefferson City is located in Cole County and Callaway County, which are separated by the 

Missouri River, and the facility is located at the river’s northern side. Regionally, the facility is 

situated on the far northern edge of the Ozark Plateau, with its boundary along the southern side 

of the Missouri River, in a geographic region known as the Mid-Missouri. The Ozark Plateau region 

is composed of Paleozoic sedimentary rocks. On the northern region of the plateau, rocks form 

an asymmetrical low dome, while the eastern side has a steep slope, and the western side has a 

shallow grade (National Park Service, 2018). Locally, the facility sits atop the alluvial deposits of 

the Missouri River Valley, and the surrounding topography has low relief (Figure 2-2).

2.2.1 Geology

The Jefferson City AASF is underlain by alluvial deposits that partially fill an entrenched bedrock 

valley. These sediments consist of sand, gravel, silt, and clay, with fine-grained material, such as 

silt and clay, generally found at the upper portion, and coarse-grained material more commonly 

found at the lower parts. The alluvial sediments average 90 feet in thickness but can be as thick 

as 160 feet (Miller and Appel, 1997). The alluvium is underlain by sedimentary bedrock, the Cotter

Dolomite, and Jefferson City Dolomite (Figure 2-3; Starbuck, 2017; Missouri Geological Survey, 

2020). The Cotter Dolomite is composed of gray to light brown, medium to finely crystalline, cherty 

dolomite that forms in thin to medium beds with interbedded shale and sandstone. The average 

thickness of the unit is 200 feet but can be up to 450 feet thick. The Jefferson City Dolomite is 

very similar to the Cotter Dolomite, and they are often mapped undivided. The Jefferson City 

Dolomite ranges from 124 to 350 feet in thickness (Howe, 1961).

Soil borings completed during the SI found silt and poorly graded sand as the dominant lithology 

of the unconsolidated sediments below Jefferson City AASF. The borings were completed at 

depths between 5 and 32 feet below ground surface (bgs). Unlike all other locations, AOI01-05 

was terminated at 5 feet bgs due to the presence of very shallow groundwater. In most borings, 

surface and shallow subsurface soil were dominated by silt with lesser amounts of clay. Some of 

the logs also reported varying percentages of limestone gravel included in the silt. Poorly graded 

sand was observed to begin between 9 and 24 feet bgs across borings. Some variation in lithology 

was observed at AOI03-03, which was located in a lower-lying, waterlogged area where surface 

water runoff collects. Isolated layers of clay, silty sand to sandy silt, and well-graded sand were 
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Army Aviation Support Facility, Jefferson City, Missouri

AECOM 2-2

also observed in the borings. Clay layers were observed at thicknesses ranging from 5 inches to 

4.2 feet. 

2.2.2 Hydrogeology

Jefferson City AASF is underlain by a stream-valley aquifer (sometimes called the Missouri River 

alluvial aquifer) that resides in the alluvial material deposited by the Missouri River. The aquifer 

consists of clay, silt, sand, and gravel, with finer clay and silt-laden flood deposits generally located 

near the surface, and layers of sand and gravel filling the deeper parts of the valley (Miller and 

Appel 1997). Wells screened in the Missouri River alluvial aquifer produce yields ranging from 

less than 100 to 3,000 gallons per minutes (Miller and Appel, 1997). Alluvial materials in the 

aquifer have an average saturated thickness of 80 feet. Recharge to the aquifer occurs from 

precipitation infiltration, stream-aquifer interaction, and from upward movement from underlying 

bedrock aquifers (Mesko and Berkas, 1987; Miller and Appel, 1997). Static water levels in 

groundwater wells located near the facility range from 3 to 25 feet bgs. Inferred groundwater flow 

direction within the stream-valley aquifer at the facility is to the south-southwest, towards the 

Missouri River, flowing downstream to the east-southeast within the localized region of the facility 

(Figure 2-3) (Missouri Geological Survey, 2020; Missouri Department of Natural Resources, 

2020). Fluctuations in the Missouri River elevation, due to flooding or rain events, may have 

potential to cause groundwater transport in the upgradient direction.

The Ozark Plateaus aquifer system underlies the Missouri River alluvial aquifer and consists of

the Springfield Plateau, Ozark, and St. Francois aquifers. At the facility, the Ozark aquifer and the 

St. Francois aquifer are present and are separated by a confining unit. The Ozark aquifer resides 

in Ordovician-aged rocks underlying the facility, including the Cotter Dolomite, the Jefferson City 

Dolomite, and the Roubidoux Formation. Geologic formations in the Kinderhookian Series act as 

an upper confining unit for the Ozark aquifer; however, these units are not present at the facility 

(Miller and Appel, 1997; Missouri Department of Natural Resources, 2020). Groundwater flow in 

the Ozark Plateaus aquifer system is inferred to flow eastwards with the Missouri River (Miller 

and Appel, 1997).

No potable water wells are located within the boundary of the AASF; however, one irrigation well 

and one well with an unknown use are in the inferred downgradient direction of the facility, and 

multiple domestic, monitoring, and irrigation wells are located approximately 1.3 miles of the 

inferred side-gradient direction of the facility (Figure 2-3). Drinking water for the AASF is supplied 

by Jefferson City, which obtains its public water supply from the deep groundwater wells (Public 

Water Supply District No. 1 of Cole County, 2018). 

Depths to water measured in February 2022 during the SI ranged from 13.43 to 27.19 feet bgs, 

with one additional location within a small runoff gully also measured at 4.48 feet bgs. Based on 

excluding groundwater elevations in this small gully (AOI01-05) and possible anomalous readings 

noted in two other boring locations (AOI01-02 and AOI02-02), groundwater flow direction is 

generally to the south. Groundwater elevation contours from the SI are presented on Figure 2-4.

2.2.3 Hydrology

Jefferson City is split by the Missouri River, which separates Cole County to the south and 

Callaway County to the north. The AASF is less than 1 mile north of the Missouri River. There are 

no permanent, naturally occurring surface water bodies at Jefferson City AASF; however, an 

unnamed stream is located northeast of the facility. Also, during severe rain, ponding of surface 

water may occur at the ramp and grassy areas – the apparent path of surface runoff and the 

footprint of ponding was observed during field activities, south of AOI 3. The direction of surface 

water flow is to the southeast of the site (Figure 2-5).
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2.2.4 Climate

The average temperature in Jefferson City is 55.25 degrees Fahrenheit (°F), with the average 

high reported at 65.8 °F and the average low reported at 44.7 °F. The warmest month is reported 

as July, with an average high of 88 °F, and the coldest month is reported as January, with an 

average low of 21 °F. Precipitation in the form of rainfall was recorded at an annual average of 

43.11 inches per year. Approximately of 12 inches of snowfall are reported each year (World 

Climate, 2022).

2.2.5 Current and Future Land Use

The AASF is a controlled-access facility with public roads and is adjacent to the Jefferson City 

Memorial Airport. The Jefferson City Memorial Airport is owned and operated by Jefferson City 

and provides commercial and general air service. Reasonably anticipated future land use is not 

expected to change from the current land use.

2.2.6 Sensitive Habitat and Threatened/ Endangered Species

The following birds, clams, fishes, flowering plants, insects, and mammals are federally 

endangered, threatened, proposed, and/ or are listed as candidate species in Callaway County, 

Missouri (US Fish and Wildlife Service [USFWS], 2022).

• Birds: Red knot, Calidris canutus rufa (threatened); Least tern, Sterna antillarum (recovery)

• Clams: Scaleshell mussel, Leptodea leptodon (endangered)

• Fishes: Topeka shiner, Notropis topeka (=tristis) (endangered); Pallid sturgeon, 

Scaphirhynchus albus (endangered)

• Flowering Plants: Eastern prairie fringed orchid, Platanthera leucophaea (threatened); 

Running buffalo clover, Trifolium stoloniferum (recovery)

• Insects: Monarch butterfly, Danaus plexippus (candidate); Regal fritillary, Speyeria idalia

(under review)

• Mammals: Gray bat, Myotis grisescens (endangered); Tricolored bat, Perimyotis subflavus

(under review); Little brown bat, Myotis lucifugus (under review); Indiana bat, Myotis sodalist

(endangered); Northern Long-Eared Bat, Myotis septentrionalis (threatened)

2.3 History of PFAS Use

Three AOIs were identified in the PA where AFFF may have been used, stored, disposed, or 

released historically at the Jefferson City AASF (AECOM, 2020). Between 1985 and 2002, annual 

nozzle testing was conducted for a firetruck that contained AFFF, followed by washing of the 

firetruck at the outdoor wash rack. Between 1999 and 2016, annual fire training exercises

occurred at the outdoor wash rack. AFFF units used during fire training were refilled at the Ground 

Service Equipment (GSE) building near the wash rack. The potential release areas were grouped 

into three AOIs based on proximity to one another and presumed groundwater flow. A description 

of each AOI is presented in Section 3.
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CLIENT

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ARNG

GIS BY

CHK BY

MS

SI

8/25/2022

8/25/2022

Site Inspection at Jefferson City AASF, MO

1:63,360

8/25/2022 ­ Figure 2-1 PM CM 8/25/2022

12420 Milestone Center Drive

Germantown, MD 20876

Facility Location

Base Map: Sources: Esri, HERE, Garmin, USGS,

Intermap, INCREMENT P, NRCan, Esri Japan, METI,

^_

Jefferson City AASF

0 0.5 1 2

Miles

Legend

Facility Boundary

PROJECT

AECOM 2-5 
CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

MB

11/15/2022 1

1

1

:

/

2

1

4

5

,

/

0

2

0

0

0

22

11/15/2022

­ Figure 2-2 PM CM 11/15/2022

12420 Milestone Center Drive

Germantown, MD 20876

Facility Topography

Base Map: USGS The National Map: National

Boundaries Dataset, 3DEP Elevation Program,

0 1,000 2,000 4,000

Feet

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Facility Boundary

PROJECT Site Inspection at Jefferson City AASF, MO
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AECOM 2-9 
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 2-10

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Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 3-1

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, five potential release areas were 

identified at Jefferson City AASF and grouped into three AOIs (AECOM, 2020). The potential 

release areas are shown on Figure 3-1.

3.1 AOI 1 West Ramp Nozzle Testing, Firetruck Storage, AFFF 

Storage

From 1985 to 2002, a firetruck with the capacity to hold three 50-gallon AFFF tanks was located 

at the AASF. Nozzle testing was conducted annually at the west ramp area. AOI 1 does not have 

drains, and the AFFF was allowed to flow off the concrete, onto the adjacent grassy areas, and 

naturally dissipate. The amount and concentration of AFFF dispensed during nozzle testing are 

unknown. The firetruck was stored in a building, located at the northeast of the west ramp area,

that is equipped with floor drains that lead to an oil/water separator (OWS) and then to the sanitary 

wastewater treatment plant (WWTP). There were no reports of any leaks or spills from the vehicle. 

Approximately 200-220 gallons of bulk AFFF were held in reserve and stored in the upper-level 

mezzanine of same building. The dispositions of the firetruck and bulk AFFF are unknown.

3.2 AOI 2 Outdoor Wash Rack FTA and GSE Building

From 1999 to 2016, annual fire training exercises with one Tri-Max30TM fire extinguisher occurred 

at the outdoor wash rack on the east side of the hangar. During each training event, one TriMax30TM extinguisher would be emptied to put out a small fire. The unit would then be refilled 

with AFFF at the outdoor wash rack area. In 2019, AFFF from three Tri-Max30TM extinguishers 

was discharged to the ground at the wash rack and refilled with climate-controlled AFFF 

concentrate to avoid freezing. The units were refilled at the GSE building on the northwest side 

of the wash rack. The GSE building and wash rack each have a drain that leads to an OWS and 

eventually to the city sanitary WWTP. Additionally, the firetruck was washed at the Outdoor Wash 

Rack fire FTA after nozzle testing, which occurred from 1985 to 2002.

3.3 AOI 3 East Ramp Nozzle Testing

As performed at AOI 1, nozzle testing for the firetruck was also conducted annually at the far east 

ramp area. AOI 3 does not have drains, and the AFFF was allowed to flow off the concrete, onto 

the adjacent grassy areas, and naturally dissipate. The amount and concentration of AFFF 

dispensed during nozzle testing are unknown.

3.4 Adjacent Sources

One off-facility, potential source was identified adjacent to the facility during the PA and are not 

associated with ARNG activities. The adjacent potential sources are shown on Figure 3-1 and 

described in the following sections for informational purposes only and will not be investigated as 

part of this SI.
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Army Aviation Support Facility, Jefferson City, Missouri

AECOM 3-2

3.4.1 Jefferson City

The Jefferson City Memorial Airport geographic coordinates are 38°35'34.74"N; 92°9'55.95"W. 

The Jefferson City Memorial Airport was constructed in 1947 and is owned and operated by 

Jefferson City. The AASF is east and adjacent to the Jefferson City Memorial Airport. There is not 

a fire department at the airport. There are several public, corporate, and private aircraft hangars 

located at the Jefferson City Memorial Airport. It is unknown if the aircraft hangars have fire 

suppression systems or if AFFF is present in the hangars.
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Army Aviation Support Facility, Jefferson City, Missouri

AECOM 3-4

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Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 4-1

4. Project Data Quality Objectives

As identified during the Data Quality Objective (DQO) process and outlined in the SI Quality 

Assurance Project Plan (QAPP) Addendum (AECOM, 2021), 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 relevant compounds at each of the sampled 

AOIs.

4.1 Problem Statement 

ARNG will recommend an AOI for Remedial Investigation (RI) if related soil and groundwater 

samples have concentrations of the relevant compounds above the OSD risk-based SLs. The 

SLs are presented in Section 6.1 of this report.

4.2 Information Inputs

Primary information inputs included:

• The PA for Jefferson City AASF (AECOM, 2020);

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

with the site-specific Uniform Federal Policy (UFP)-QAPP Addendum (AECOM, 2021); and

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

parameters measured at the time of sampling.

4.3 Study Boundaries

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

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

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

owner(s). Temporal boundaries were limited to the winter season, which was the earliest available 

time field resources were available to complete the study.

4.4 Analytical Approach

Samples were analyzed by Pace Analytical Gulf Coast, accredited under the Department of 

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

74960) and the National Environmental Laboratory Accreditation Program (NELAP; Certificate

Number 01955). Data were compared to applicable SLs within this document and decision rules 

as defined in the SI QAPP Addendum (AECOM, 2021). 
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Army Aviation Support Facility, Jefferson City, Missouri

AECOM 4-2

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 decisionmaking (DoD, 2019a; DoD, 2019b; USEPA, 2017).

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 SI QAPP Addendum (AECOM, 2021).
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Army Aviation Support Facility, Jefferson City, Missouri

AECOM 5-1

5. Site Inspection Activities

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

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

in accordance with the following approved documents:

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

(PQAPP) dated March 2018 (AECOM, 2018a);

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

• Final Preliminary Assessment Report, Jefferson City AASF, Jefferson City, Missouri dated 

March 2020 (AECOM, 2020);

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

Jefferson City AASF, Jefferson City, Missouri dated October 2021 (AECOM, 2021); and

• Final Site Safety and Health Plan, Jefferson City AASF, Jefferson City, Missouri dated 

January 2022 (AECOM, 2022).

The SI field activities were conducted from 14 to 19 February 2022 and consisted of utility clearance,

direct push boring, soil sample collection, temporary monitoring well installation, grab groundwater 

sample collection, and land surveying. Field activities were conducted in accordance with the SI 

QAPP Addendum (AECOM, 2021), except as noted in Section 5.8.

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

by liquid chromatography with tandem mass spectrometry (LC/MS/MS) compliant with Quality 

Systems Manual (QSM) 5.3 Table B-15 to fulfill the project DQOs:

• Thirty-three (33) soil samples from 15 boring locations;

• Eleven (11) grab groundwater samples from 12 temporary well locations;

• Twenty (20) quality assurance (QA)/quality control (QC) samples.

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

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

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

in Appendix B1. Sampling forms are provided in Appendix B2, a Field Change Request is 

provided in Appendix B3, land survey data are provided in Appendix B4, and investigationderived waste (IDW) polygons are provided in Appendix B5. Additionally, a photographic log of 

field activities is provided in Appendix C.

5.1 Pre-Investigation Activities

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

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

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

5.1.1 Technical Project Planning

The US Army Corps of Engineers (USACE) TPP Process, Engineer Manual (EM) 200-1-2 

(USACE, 2016) defines four phases to project planning: 1.) defining the project phase; 2.) 

determining data needs; 3.) developing data collection strategies; and 4.) finalizing the data 

collection plan. The process encourages stakeholder involvement in the SI, beginning with 
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Army Aviation Support Facility, Jefferson City, Missouri

AECOM 5-2

defining overall project objectives, including DQOs, and formulating a sampling approach to 

address the AOIs identified in the PA.

A combined TPP Meeting 1 and 2 was held on 8 June 2021, prior to SI field activities. The 

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

stakeholders for this SI include the ARNG, MOARNG, USACE, Missouri Department of Natural 

Resources, and representatives familiar with the facility, the regulations, and the community.

Stakeholders were provided the opportunity to make comments on the technical sampling 

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

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

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

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

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

5.1.2 Utility Clearance

AECOM placed a ticket with Missouri One Call System, the local utility clearance provider, to 

notify them of intrusive work on 3 February 2022. However, because the AASF is a private facility, 

the participating utility locators did not clear utilities at the entire facility. Therefore, AECOM 

contracted Ground Penetrating Radar Systems (GPRS), LLC, a private utility location service, to 

perform utility clearance. GPRS performed utility clearance of the proposed boring locations on 

14 February 2022 with input from the AECOM field team and Jefferson City AASF facility staff. 

General locating services and ground-penetrating radar were used to complete the clearance.

Additionally, the first 5 feet of each boring were pre-cleared using a hand auger to verify utility 

clearance in shallow subsurface where utilities would typically be encountered.

5.1.3 Source Water and Sampling Equipment Acceptability

One potable water source at Jefferson City AASF was sampled on 22 October 2021 to assess 

usability for decontamination of drilling equipment. 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 potable water 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 

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

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

(AECOM, 2021). Prior to the start of field work each day, a Sampling Checklist was completed as 

an additional layer of control. The checklist served as a daily reminder to each field team member 

regarding the allowable materials within the sampling environment.

5.2 Soil Borings and Soil Sampling

Soil samples were collected via direct push technology (DPT), in accordance with the SI QAPP 

Addendum (AECOM, 2021). A GeoProbe® 7822DT dual-tube sampling system was used to collect 

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

feet of the boring, in accordance with AECOM utility clearance procedures. The soil boring 

locations are shown on Figure 5-1, and sample depths are provided Table 5-1.

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

from each soil boring: one surface soil sample (0 to 2 feet bgs), one subsurface soil sample 
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Army Aviation Support Facility, Jefferson City, Missouri

AECOM 5-3

approximately 2 feet above the groundwater table, and one subsurface soil sample at the midpoint between the surface and the groundwater table. In borings where groundwater was 

encountered at 6 feet bgs or shallower, only two soil samples were collected per boring, in 

accordance with the QAPP Addendum (AECOM, 2021).

The soil cores were continuously logged for lithological descriptions by an AECOM field geologist 

using the Unified Soil Classification System (USCS). A photoionization detector (PID) was used 

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

Observations and measurements were recorded on boring logs (Appendix E) and in a nontreated field logbook (i.e., composition notebook). Depth interval, recovery thickness, PID 

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

(using the USCS) were recorded. The boring logs are provided in Appendix E.

During the SI, soil borings were generally completed at depths between 16 and 32 feet bgs, with 

the exception of AOI01-05, which was completed at 5 feet bgs due to the presence of very shallow 

groundwater. Silt and poorly graded sand were observed as the dominant lithology of the 

unconsolidated sediments below Jefferson City AASF. In most borings, surface and shallow 

subsurface soil were dominated by silt with lesser amounts of clay. Some of the logs also reported 

varying percentages of limestone gravel included in the silt. Poorly graded sand was observed to 

begin between 9 and 24 feet bgs across borings. Some variation in lithology was observed at 

AOI03-03, which was located in a lower-lying, waterlogged area where surface water runoff 

collects. Isolated layers of clay, silty sand to sandy silt, and well-graded sand were also observed 

in the borings. Clay layers were observed at thicknesses ranging from 5 inches to 4.2 feet.

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

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

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

to the laboratory and analyzed by LC/MS/MS compliant with QSM 5.3 Table B-15, total organic 

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

SI QAPP Addendum (AECOM, 2021).

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

as the accompanying samples. Matrix spike (MS)/MS duplicates (MSDs) were collected at a rate 

of 5% and analyzed for the same parameters as the accompanying samples. In instances when 

non-dedicated sampling equipment was used, such as a hand auger for the shallow soil samples, 

equipment rinsate blanks were collected at a rate of 5% and analyzed for the same parameters 

as the soil samples. A temperature blank was placed in each cooler to ensure that samples were 

preserved at or below 6 degrees Celsius (°C) during shipment.

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

accordance with the SI QAPP Addendum (AECOM, 2021) using bentonite chips or concrete slurry

at completion of sampling activities. Borings were installed in grass areas to avoid disturbing 

concrete or asphalt surfaces.

5.3 Temporary Well Installation and Groundwater Grab Sampling

Temporary wells were installed using a GeoProbe® 7822DT dual-tube sampling system. Once the 

borehole was advanced to the desired depth, wherever conditions allowed, a temporary well was 

constructed of a 5-foot section of 1-inch Schedule 40 poly-vinyl chloride (PVC) screen with 

sufficient casing to reach ground surface. New PVC pipe and screen were used to avoid cross 

contamination between locations. The screen intervals for the temporary wells are provided in 

Table 5-2.

Groundwater samples were collected after a period of time following well installation to allow 

groundwater to infiltrate and recharge the temporary well screen intervals. After the recharge 
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 5-4

period, groundwater samples were collected using a peristaltic pump with PFAS-free HDPE 

tubing. The temporary wells were purged at a rate determined in the field to reduce turbidity and 

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

pH, dissolved oxygen, 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. 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.

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

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

standard CoC procedures to the laboratory and analyzed by LC/MS/MS compliant with QSM 5.3

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

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

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

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

accordance with the PQAPP (AECOM, 2018a). A temperature blank was placed in each cooler to 

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

Following well surveying (described below in Section 5.5), temporary wells were abandoned in 

accordance with the SI QAPP Addendum (AECOM, 2021) by removing the PVC and backfilling 

the hole with bentonite chips or concrete slurry. Temporary wells were installed in grass areas to 

avoid disturbing concrete or asphalt.

5.4 Synoptic Water Level Measurements

A synoptic groundwater gauging event was performed on 18 February 2022. Groundwater 

elevation measurements were collected from the 12 new temporary monitoring wells. Water level 

measurements were taken from the northern side of the well casing. Groundwater flow direction 

is discussed in Section 2.2.2. A groundwater flow contour map is provided in Figure 2-4. 

Groundwater elevation data are provided in Table 5-2.

5.5 Surveying

The northern side of each well casing was surveyed by Missouri-licensed land surveyors following 

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

data from the newly installed wells on the facility were collected on 18 February 2022 in the 

applicable Universal Transverse Mercator zone projection with World Geodetic System 84 datum 

(horizontal) and North American Vertical Datum 1988 (vertical). The surveyed well data are 

provided in Appendix B4.

5.6 Investigation-Derived Waste

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

federally. IDW generated during the SI is considered non-hazardous waste and was managed in 

accordance with the SI QAPP Addendum (AECOM, 2021) and with the DA Guidance for 

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

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

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

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

soil samples collected from that source location.
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 5-5

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

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

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

associated groundwater samples collected from that source location.

Geographic coordinates were collected using a Global positioning system (GPS) around each 

location where IDW was placed (i.e., an IDW polygon). The IDW polygons are displayed on the 

figure in Appendix B5.

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 at a licensed solid waste landfill.

5.7 Laboratory Analytical Methods

Samples were analyzed by LC/MS/MS compliant with QSM 5.3 Table B-15 at Pace Analytical Gulf 

Coast in Baton Rouge, Louisiana, a DoD ELAP and NELAP certified laboratory. Soil samples 

were also analyzed for TOC using USEPA Method 9060A and pH by USEPA Method 9045D.

5.8 Deviations from SI QAPP Addendum

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

documentation. These deviations are noted below and documented in a Field Change Request 

Form (Appendix B3):

• During the site walk on 14 February 2022, AOI01-03 and AOI03-03 were relocated from 

their originally proposed locations. AOI01-03 was moved approximately 55 feet south, due 

to presence of utilities (high-pressure natural gas, electric, communications). Additionally, 

soil sampling was added at AOI01-03, which was originally proposed as a temporary 

monitoring well only, based on the apparent drainage of the adjacent concrete slab 

towards the relocated sample location. AOI03-03 was moved approximately 45 feet east, 

due to the apparent path of surface runoff drainage, to be closer to the area of water 

impoundment. Based on field observations, the footprint of the apparent area of water 

impoundment extends further than originally assumed based on aerial imagery, towards 

the revised location of AOI03-03. AOI03-03 was originally scoped as a temporary well with 

no soil samples; however, based on this new observation, soil sampling was added to 

AOI03-03.

• Due to a laboratory error, the grain size sample collected at locations AOI01-01 and 

AOI02-02 could not be analyzed. This deviation was documented in a nonconformance 

and corrective action report provided in Appendix B3.
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 5-6

THIS PAGE INTENTIONALLY BLANK
Table 5-1

Site Inspection Samples by Medium

Site Inspection Report, Jefferson City AASF, Missouri

Sample Identification

Sample

Collection 

Date/Time

Sample Depth 

(feet bgs)

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

Comments

AOI01-01-SB-00-02 2/16/2022 9:50 0 - 2 x x x

AOI01-01-SB-00-02-D 2/16/2022 9:50 0 - 2 x FD

AOI01-01-SB-00-02-MS 2/16/2022 9:51 0 - 2 x MS

AOI01-01-SB-00-02-MSD 2/16/2022 9:51 0 - 2 x MSD

AOI01-01-SB-08-09 2/16/2022 11:00 8 - 9 x

AOI01-01-SB-09-10 2/16/2022 11:05 9 - 10 x

AOI01-01-SB-24-25 2/16/2022 10:05 24 - 25 x

AOI01-02-SB-00-02 2/16/2022 11:50 0 - 2 x

AOI01-02-SB-08-09 2/16/2022 12:35 8 - 9 x

AOI01-02-SB-12-13 2/16/2022 16:05 12 - 13 x

AOI01-02-SB-15-16 2/16/2022 12:30 15 - 16 x

AOI01-03-SB-00-02 2/14/2022 15:26 0 - 2 x

AOI01-03-SB-12-13 2/14/2022 15:35 12 - 13 x

AOI01-03-SB-23-24 2/14/2022 15:40 23 - 24 x

AOI01-04-SB-00-02 2/14/2022 15:45 0 - 2 x

AOI02-01-SB-00-02 2/17/2022 12:45 0 - 2 x

AOI02-01-SB-10-11 2/17/2022 13:40 10 - 11 x

AOI02-01-SB-21.5-22.5 2/17/2022 13:35 21.5 - 22.5 x

AOI02-02-SB-00-02 2/16/2022 15:40 0 - 2 x

AOI02-02-SB-00-02-D 2/16/2022 15:40 0 - 2 x FD

AOI02-02-SB-00-02-MS 2/16/2022 15:40 0 - 2 x MS

AOI02-02-SB-00-02-MSD 2/16/2022 15:40 0 - 2 x MSD

AOI02-02-SB-09-10 2/16/2022 16:20 9 - 10 x

AOI02-02-SB-17-18 2/16/2022 16:15 17 - 18 x

AOI02-03-SB-00-02 2/16/2022 14:00 0 - 2 x x x

AOI02-03-SB-00-02-D 2/16/2022 14:00 0 - 2 x x FD

AOI02-03-SB-00-02-MS 2/16/2022 14:02 0 - 2 x x MS

AOI02-03-SB-00-02-MSD 2/16/2022 14:02 0 - 2 x x MSD

AOI02-03-SB-12-13 2/16/2022 14:50 12 - 13 x

AOI02-03-SB-22-23 2/16/2022 14:45 22 - 23 x

AOI02-04-SB-00-02 2/18/2022 10:10 0 - 2 x

AOI02-04-SB-11-12 2/18/2022 12:20 11 - 12 x

AOI02-04-SB-24-25 2/18/2022 12:15 24 - 25 x

AOI03-01-SB-00-02 2/15/2022 16:10 0 - 2 x

AOI03-01-SB-08-09 2/15/2022 16:35 8 - 9 x

AOI03-01-SB-13-14 2/15/2022 16:30 13 - 14 x

AOI03-02-SB-00-02 2/15/2022 14:00 0 - 2 x

AOI03-02-SB-06-07 2/15/2022 14:47 6 - 7 x

AOI03-02-SB-16-16.75 2/15/2022 14:40 16 - 16.75 x

AOI03-03-SB-00-02 2/15/2022 12:40 0 - 2 x

AOI03-03-SB-07-08 2/15/2022 12:58 7 - 8 x

AOI03-03-SB-10-11 2/15/2022 12:55 10 - 11 x

AOI03-04-SB-00-02 2/16/2022 8:50 0 - 2 x x x

AOI03-04-SB-00-02-D 2/16/2022 8:50 0 - 2 x FD

AOI03-04-SB-00-02-MS 2/16/2022 8:52 0 - 2 x MS

AOI03-04-SB-00-02-MSD 2/16/2022 8:52 0 - 2 x MSD

AOI03-05-SB-00-02 2/15/2022 13:37 0 - 2 x

AOI01-01-GW 2/16/2022 13:30 NA x

AOI01-02A-GW 2/19/2022 14:20 NA x

Soil Samples

Groundwater Samples

AECOM 5-7 
Table 5-1

Site Inspection Samples by Medium

Site Inspection Report, Jefferson City AASF, Missouri

Sample Identification

Sample

Collection 

Date/Time

Sample Depth 

(feet bgs)

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

Comments

AOI01-03A-GW 2/19/2022 12:45 NA x

AOI01-03A-GW-D 2/19/2022 12:45 NA x FD

AOI01-05-GW 2/15/2022 13:13 NA x

AOI02-01-GW 2/18/2022 16:40 NA x

AOI02-01-GW-D 2/18/2022 16:40 NA x FD

AOI02-01-GW-MS 2/18/2022 16:40 NA x MS

AOI02-01-GW-MSD 2/18/2022 16:40 NA x MSD

AOI02-03-GW 2/16/2022 15:50 NA x

AOI02-04-GW 2/18/2022 13:51 NA x

AOI02-05-GW 2/16/2022 11:14 NA x

AOI03-01-GW 2/16/2022 9:26 NA x

AOI03-02-GW 2/15/2022 17:00 NA x

AOI03-03-GW 2/15/2022 14:56 NA x

JC-DECON-01 10/22/2021 11:30 NA x source water

JC-DECON-02 2/16/2022 9:15 NA x

decon water from 

drill rig

JC-DECON-03 2/19/2022 10:50 NA x

decon water from 

drill rig with 

replaced valve

JC-ERB-01 2/16/2022 8:35 NA x hand auger

JC-ERB-02 2/16/2022 8:40 NA x cutting shoe

JC-ERB-03 2/19/2022 10:55 NA x 2nd cutting shoe

JC-FRB-01 2/16/2022 8:45 NA x

field reagent

blank

Notes:

AASF = Army Aviation Support Facility

AOI = area of interest

ASTM = American Society for Testing and Materials

bgs = below ground surface

DECON = decontamination

ERB = equipment rinsate blank

FD = field duplicate

FRB = field reagent blank

GW = groundwater

LC/MS/MS = Liquid Chromatography Mass Spectrometry

MS/MSD = matrix spike/ matrix spike duplicate

NA = not applicable

QSM = Quality Systems Manual

SB = soil boring

TOC = total organic carbon

USEPA = United States Environmental Protection Agency

Quality Control Samples

AECOM 5-8 
Table 5-2

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

Site Inspection Report, Jefferson City AASF, Missouri

Area of 

Interest

Boring 

Location

Soil Boring 

Depth 

(feet bgs)

Temporary Well 

Screen Interval 

(feet bgs)

Top of Casing 

Elevation 

(feet NAVD88)

Ground Surface 

Elevation 

(feet NAVD88)

Depth to 

Water

(feet btoc)

Dept

Wa

(feet 

AOI01-01 28 23 - 28 555.87 554.98 27.95 27AOI01-02 24 19 - 24 554.87 553.76 25.00 23

AOI01-02A 30 24.7 - 29.7 NM NM 26.40 N

AOI01-03 28 23 - 28 556 553.19 27.90 25

AOI01-03A 30 24.9 - 29.9 NM NM 25.48 N

AOI01-04 2 NA NA 554.02 NA NAOI01-05 5 0 - 5 552.06 551.93 4.61 4.4

AOI02-01 28 23 - 28 555.17 553.18 27.27 25

AOI02-02 28 22.9 - 27.9 556.94 554.85 28.37 26AOI02-03 32 27 - 32 557.62 555.05 29.76 27AOI02-04 28 23 - 28 557.69 555.08 29.74 27AOI02-05 20 14.95 - 19.75 543.49 543.29 15.76 15

AOI03-01 20 14.2 - 19.2 546.26 545.61 18.37 17

AOI03-02 20 15 - 20 546.51 546.24 18.68 18AOI03-03 16 11 - 16 543.26 541.11 15.58 13AOI03-04 2 NA NA 546.61 NA NAOI03-05 2 NA NA 541.93 NA N

321

Notes:

1 Temporary well screen set above total depth to capture groundwater interface

2 Temporary wells AOI01-02A and AOI01-03A are redrilled locations due to lack of groundwater in original wells. Redrilling occurred after well survey.

AASF = Army Aviation Support FacilityAOI = area of interest

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

NM = not measured

AECOM 
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 5-10

THIS PAGE INTENTIONALLY BLANK
?!

?!

?!

?!

?!

?!

?!

"S

?!

"S ?!

?!

?!

?!

"S

GSE Building

Firetruck Storage Building

and AFFF Storage AOI 3

AOI 2

AOI 1

East Ramp

Nozzle Testing

West Ramp

Nozzle Testing

Outdoor Wash

Rack FTA

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI03-04

AOI01-05

AOI01-04

AOI02-02

AOI02-03

AOI02-04

AOI02-05

AOI03-05

­ Figure 5-1

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Jefferson City AASF, MO

11/15/2022

11/15/2022

11/15/2022

MS

MB

CM

GIS BY

CHK BY

PM

Base Map: Source: Esri, Maxar, Earthstar Geographics, and the GIS User Community

11/15/2022

1:1,680

Site Inspection Sample Locations

12420 Milestone Center Drive

Germantown, MD 20876

?! Soil Boring/Temporary Monitoring Well

?! Temporary Monitoring Well

"S Surface Soil Sample

Area of Interest

Potential Release Area

Facility Boundary

Surface Water Flow Direction

Groundwater Flow Direction

0 70 140 280

Feet
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 5-12

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 6-1

6. Site Inspection Results

This section presents the analytical results of the SI. The SLs used in this evaluation are 

presented in Section 6.1. A discussion of the results for each AOI is provided in Section 6.3

through Section 6.5. Table 6-2 through Table 6-5 present results in soil or groundwater for the 

relevant compounds. Tables that contain all results are provided in Appendix F, and the 

laboratory reports are provided in Appendix G. 

6.1 Screening Levels 

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

SLs for soil and groundwater, as described in a memorandum from the OSD dated 6 July 2022 

(Assistant Secretary of Defense, 2022). The ARNG program under which this SI was performed 

follows this DoD policy. Should the maximum site concentration for sampled media exceed the 

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

The SLs established in the OSD memorandum apply to the five compounds presented on Table 

6-1 below.

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

Analyteb

Residential

(Soil)

(μg/kg)a 

0-2 feet bgs

Industrial/ 

Commercial 

Composite 

Worker 

(Soil)

(μg/kg)a 

2-15 feet bgs

Tap Water

(Groundwater) 

(ng/L)a

PFOA 19 250 6 

PFOS 13 160 4

PFBS 1,900 25,000 601 

PFHxS 130 1,600 39

PFNA 19 250 6 

Notes:

bgs = below ground surface; μg/kg = micrograms per kilogram; ng/L = nanograms per liter

a.) Assistant Secretary of Defense, 2022. Risk Based Screening Levels in Groundwater and Soil using United States Environmental Protection 

Agency’s (USEPA’s) Regional Screening Level Calculator. Hazard Quotient (HQ) = 0.1. 6 July 2022. 

b.) 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. 

The data in the subsequent sections are compared to the SLs presented in Table 6-1. The SLs 

for groundwater are based on direct ingestion. The SLs for soil are based on incidental ingestion 

and are applied to the depth intervals reasonably anticipated to be encountered by the receptors 

identified at the facility: the residential scenario is applied to surface soil results (0 to 2 feet bgs) 

and the industrial/commercial worker scenario is applied to shallow subsurface soil results (2 to 

15 feet bgs). The SLs are not applied to deep subsurface soil results (>15 feet bgs) because 15 

feet is the anticipated limit of construction activities.
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 6-2

6.2 Soil Physicochemical Analyses

To provide basic soil parameter information, select 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. According to the Interstate Technology Regulatory 

Council (ITRC), several important partitioning mechanisms include hydrophobic and lipophobic 

effects, electrostatic interactions, and interfacial behaviors. At relevant environmental pH values, 

certain PFAS are present as organic anions and are therefore relatively mobile in groundwater 

(Xiao et al., 2015), but tend to associate with the organic carbon fraction that may be present in 

soil or sediment (Higgins and Luthy, 2006; Guelfo and Higgins, 2013). When sufficient organic 

carbon is present, organic carbon normalized distribution coefficients (Koc values) can help in 

evaluating transport potential, though other geochemical factors (for example, pH and presence 

of polyvalent cations) may also affect PFAS sorption to solid phases (ITRC, 2018).

6.3 AOI 1

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

AOI 1: West Ramp Nozzle Testing, Firetruck Storage, and AFFF Storage. The soil and 

groundwater results are summarized on Table 6-2 through Table 6-5. Soil and groundwater 

results are presented on Figure 6-1 through Figure 6-7.

6.3.1 AOI 1 Soil Analytical Results

Figure 6-1 through Figure 6-5 present the ranges of detections in soil. Table 6-2 through Table 

6-4 summarize the soil results.

Soil was sampled from surface soil (0 to 2 feet bgs) from boring locations AOI01-01 through 

AOI01-04. Soil was also sampled from shallow subsurface soil (8 to 13 feet bgs) and deep 

subsurface soil intervals (15 to 25 feet bgs) from boring locations AOI01-01 through AOI01-03.

PFOS exceeded the SL in surface soil. PFOA, PFBS, PFHxS, and PFNA were detected in soil at 

concentrations at least one order of magnitude below the SLs.

In surface soil, PFOS exceeded the SL of 13 micrograms per kilogram (μg/kg) at AOI01-01, 

AOI01-02, and AOI01-04 at concentrations of 75.2 μg/kg, 50.8 μg/kg, and 20.4 μg/kg, 

respectively. PFOA, PFBS, PFHxS, and PFNA were detected in surface soil at concentrations at 

least one order of magnitude below the SLs. The maximum concentration of these four 

compounds was PFHxS, which was detected at 2.30 μg/kg at AOI01-01.

In shallow subsurface soil, PFNA was not detected. PFOA, PFOS, PFBS, and PFHxS were only 

detected at AOI01-01 (8 to 9 feet bgs), at least two orders of magnitude below their SLs. The 

maximum detected concentration among the four detected compounds was PFOS, which was 

detected at 0.761 J μg/kg.

PFOA, PFOS, PFBS, PFHxS, and PFNA were detected in deep subsurface soil. The maximum 

detected concentration among the five compounds was PFOS, which was detected at 23.7 μg/kg

at AOI01-03 (23 to 24 feet bgs).

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.
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 6-3

Groundwater was sampled from temporary monitoring wells AOI01-01, AOI01-02A, AOI01-03A,

and AOI01-05. The following exceedances were reported:

• PFOA was detected above the SL of 6 nanograms per liter (ng/L), at concentrations of 

454 ng/L at AOI01-01, 729 ng/L at AOI01-02A, and 181 ng/L at AOI01-03A.

• PFOS was detected above the SL of 4 ng/L, at concentrations of 8,370 ng/L at AOI01-

01, 282 ng/L at AOI01-02A, and 12,700 ng/L at AOI01-03A.

• PFHxS was detected above the SL of 39 ng/L, at concentrations of 4,060 ng/L at AOI01-

01, 3,090 ng/L at AOI01-02A, and 423 ng/L at AOI01-03A.

• PFNA was detected above the SL of 6 ng/L, at concentrations of 189 ng/L at AOI01-01, 

27.5 ng/L at AOI01-02A, and 401 ng/L at AOI01-03A.

PFBS was detected below the SL of 601 ng/L in all four wells, with the maximum PFBS 

concentration detected at 495 ng/L at AOI01-02A.

6.3.3 AOI 1 Conclusions

Based on the results of the SI, PFOS was detected in surface soil above the SL. PFOA, PFHxS, 

PFNA, and PFBS were detected in soil, at concentrations at least one order of magnitude below 

their SLs. PFOA, PFOS, PFHxS, and PFNA were detected in groundwater at concentrations 

above their SLs. Based on the exceedances of the SLs in soil and groundwater, further evaluation 

at AOI 1 is warranted.

6.4 AOI 2

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

AOI 2: Outdoor Wash Rack FTA and GSE Building. The results in soil and groundwater are 

summarized on Table 6-2 through Table 6-5. Soil and groundwater results are presented on 

Figure 6-1 through Figure 6-7.

6.4.1 AOI 2 Soil Analytical Results

Figure 6-1 through Figure 6-5 present the ranges of detections in soil. Table 6-2 through Table 

6-4 summarize the soil results.

Soil was sampled from surface soil (0 to 2 feet bgs), shallow subsurface soil (9 to 13 feet bgs),

and deep subsurface soil (17 to 25 feet bgs) from boring locations AOI02-01 through AOI02-04. 

PFOS exceeded the SL in surface soil. PFOA, PFBS, PFHxS, and PFNA were detected in soil at 

concentrations at least one order of magnitude below the SLs.

In surface soil, PFOS exceeded the SL of 13 μg/kg at AOI02-02, AOI02-03, and AOI02-04, at 

concentrations of 14.6 μg/kg, 27.9 μg/kg, and 58.2 μg/kg, respectively. PFOA, PFBS, PFHxS, and 

PFNA were detected in surface soil, at concentrations below the SLs. The maximum detected

concentration of these four compounds was PFNA at 2.44 μg/kg at AOI02-04.

In shallow subsurface soil, PFOA, PFOS, PFBS, PFHxS, and PFNA were detected at 

concentrations at least one order of magnitude below the SLs. The maximum concentration 

among the detected compounds was PFOS at 15.6 μg/kg at AOI02-03 (12 to 13 feet bgs).

PFOA, PFOS, PFBS, and PFHxS were detected in deep subsurface soil. The maximum detected 

concentration among the five compounds was PFOS at 1.69 μg/kg at AOI02-01 (21.5 to 22.5 feet 

bgs). PFNA was not detected in deep subsurface soil.
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 6-4

6.4.2 AOI 2 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 was sampled from temporary monitoring wells AOI02-01, AOI02-03, AOI02-04, and

AOI02-05. PFOA, PFOS, PFHxS, and PFNA exceeded their SLs in groundwater at all four well 

locations:

• PFOA was detected above the SL of 6 ng/L, at concentrations of 157 ng/L at AOI02-01, 

158 ng/L at AOI02-03, 437 ng/L at AOI02-04, and 156 ng/L at AOI02-05.

• PFOS was detected above the SL of 4 ng/L, at concentrations of 3,130 ng/L at AOI02-

01, 101 ng/L at AOI02-03, 2,630 ng/L at AOI02-04, and 1,250 ng/L at AOI02-05.

• PFHxS was detected above the SL of 39 ng/L, at concentrations of 669 ng/L at AOI02-

01, 1,180 ng/L at AOI02-03, 742 ng/L at AOI02-04, and 526 ng/L at AOI02-05.

• PFNA was detected above the SL of 6 ng/L, at concentrations of 14.0 ng/L at AOI02-

01, 11.5 ng/L at AOI02-03, 147 ng/L at AOI02-04, and 26.4 ng/L at AOI02-05.

PFBS was detected below the SL of 601 ng/L in all four wells, with the maximum PFBS 

concentration detected at 206 ng/L at AOI02-03.

6.4.3 AOI 2 Conclusions

Based on the results of the SI, PFOS was detected in surface soil above the SL. PFOA, PFHxS, 

PFNA, and PFBS were detected in soil, at concentrations below their SLs. PFOA, PFOS, PFHxS, 

and PFNA were detected in groundwater, at concentrations above their SLs. Based on the 

exceedances of the SLs in soil and groundwater, further evaluation at AOI 2 is warranted.

6.5 AOI 3

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

AOI 3: East Ramp Nozzle Testing. The results in soil and groundwater are presented in Table 6-

2 through Table 6-5. Soil and groundwater results are presented on Figure 6-1 through Figure 6-

7.

6.5.1 AOI 3 Soil Analytical Results

Figure 6-1 through Figure 6-5 present the ranges of detections in soil. Table 6-2 through Table 

6-4 summarize the soil results.

Soil was sampled from surface soil (0 to 2 feet bgs) from boring locations AOI03-01 through 

AOI03-05. Soil was also sampled from shallow subsurface soil (6 to 14 feet bgs) from boring 

locations AOI03-01 through AOI03-03, and deep subsurface soil (16 to 16.75 feet bgs) from boring 

location AOI03-02. PFOS exceeded the SL in surface soil. PFOA, PFBS, PFHxS, and PFNA were 

detected in soil, at concentrations at least one order of magnitude below the SLs.

PFOS was detected above the SL of 13 μg/kg in surface soil at AOI03-03, with a concentration of 

14.5 μg/kg. PFOA, PFHxS, and PFNA were detected in surface soil, at concentrations below the 

SLs. The maximum detected concentration of these four compounds was PFNA at 0.312 J μg/kg 

at AOI03-03. PFBS was not detected in surface soil.

In shallow subsurface soil, PFOA, PFOS, PFBS, PFHxS, and PFNA were detected at least one

orders of magnitude below their SLs. The maximum detected concentration among the four 
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 6-5

detected compounds was PFOS, which was detected at 6.74 μg/kg at AOI03-03 (10 to 11 feet 

bgs).

PFOA, PFOS, PFBS, and PFNA were not detected in the deep subsurface soil sample collected 

at AOI 3. PFHxS was detected at a concentration of 0.110 J μg/kg.

6.5.2 AOI 3 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 was sampled from temporary monitoring wells AOI03-01, AOI03-02, and AOI03-03. 

The following exceedances of the SLs were reported:

• PFOA was detected above the SL of 6 ng/L, at a concentration of 31.3 ng/L at AOI03-

03.

• PFOS was detected above the SL of 4 ng/L, at a concentration of 1,190 ng/L at AOI03-

03.

• PFHxS was detected above the SL of 39 ng/L at all three wells, at concentrations of

181 ng/L at AOI03-01, 156 ng/L at AOI03-02, and 119 ng/L at AOI03-03.

• PFNA was detected above the SL of 6 ng/L, at a concentration of 8.67 ng/L at AOI03-

03.

PFBS was detected below the SL of 601 ng/L at all three wells, with a maximum concentration of

41.1 ng/L at AOI03-01.

6.5.3 AOI 3 Conclusions

Based on the results of the SI, PFOS was detected in surface soil above the SL. PFOA, PFHxS, 

PFNA, and PFBS were detected in soil at concentrations below their SLs. PFOA, PFOS, PFHxS, 

and PFNA were detected in groundwater, at concentrations above their SLs. Based on the 

exceedances of the SLs in soil and groundwater, further evaluation at AOI 3 is warranted.
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 6-6

THIS PAGE INTENTIONALLY BLANK
Table 6-2

PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Surface Soil

Site Inspection Report, Jefferson City AASF

Analyte OSD Screening 

Level a

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

PFBS 1900 0.046 J 0.043 J 0.036 J ND U ND U ND U ND UJ 0.026 J 0.044 J ND U

PFHxS 130 2.28 2.30 1.09 0.568 J 0.178 J 0.202 J 0.261 J 0.378 J 0.937 J 0.371 J

PFNA 19 1.25 1.38 1.22 0.463 J 0.217 J 0.124 J 0.621 J 0.948 J 0.772 J 2.44

PFOA 19 0.467 J 0.561 J 0.494 J 0.550 J 0.131 J 0.308 J 0.626 J 0.953 J 0.619 J 1.32

PFOS 13 65.5 J 75.2 50.8 3.15 20.4 4.04 12.3 14.6 27.9 58.2

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

PFBS perfluorobutanesulfonic acid

References PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

PFOA perfluorooctanoic acid

Interpreted Qualifiers Acronyms and Abbreviations

J = Estimated concentration AASF Army Aviation Support Facility

U = The analyte was not detected at a level greater than or equal to the adjusted DL AOI Area of Interest

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

DL detection limit

Notes ft feet

ND = Analyte not detected above the LOD. LOD values are presented in Appendix F. HQ hazard quotient

ID identification

LCMSMS liquid chromatography with tandem mass spectrometry

LOD limit of detection

ND analyte not detected above the LOD

OSD Office of the Secretary of Defense

QSM Quality Systems Manual

Qual interpreted qualifier

SB soil boring

USEPA United States Environmental Protection Agency

μg/kg micrograms per kilogram

a. Assistant Secretary of Defense, July 2022. Risk Based Screening Levels Calculated for PFOA, PFOS, PFBS, PFHxS, and PFNA in Groundwater or Soil using USEPA’s Regional

Screening Level Calculator. HQ=0.1, May 2022. Soil screening levels based on residential scenario for incidental ingestion of contaminated soil.

Area of Interest

Sample ID

Sample Date

Depth

AOI01

AOI01-01-SB-00-02

02/16/2022

0-2 ft

AOI01

AOI01-01-SB-00-02-D

02/16/2022

0-2 ft

AOI01

AOI01-02-SB-00-02

02/16/2022

0-2 ft

AOI01

AOI01-03-SB-00-02

02/14/2022

0-2 ft

AOI02-04-SB-00-02

02/18/2022

0-2 ft

AOI01

AOI01-04-SB-00-02

02/14/2022

0-2 ft

02/17/2022

0-2 ft

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

AOI02

AOI02-02-SB-00-02-D

02/16/2022

0-2 ft

AOI02

AOI02-03-SB-00-02

02/16/2022

0-2 ft

AOI02

AOI02-01-SB-00-02

AOI02

AOI02-02-SB-00-02

02/16/2022

0-2 ft

AOI02

AECOM 6-7
Table 6-2

PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Surface Soil

Site Inspection Report, Jefferson City AASF

Analyte OSD Screening 

Level a

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

PFBS 1900 ND U ND U ND U ND U ND U ND U

PFHxS 130 0.061 J ND U 0.205 J 0.084 J 0.076 J 0.084 J

PFNA 19 0.233 J ND U 0.312 J 0.113 J 0.086 J 0.072 J

PFOA 19 0.133 J ND U 0.176 J 0.144 J 0.122 J ND U

PFOS 13 6.48 0.167 J 14.5 3.69 2.83 1.59

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

PFBS perfluorobutanesulfonic acid

References PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

PFOA perfluorooctanoic acid

Interpreted Qualifiers Acronyms and Abbreviations

J = Estimated concentration AASF Army Aviation Support Facility

U = The analyte was not detected at a level greater than or equal to the adjusted DL AOI Area of Interest

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

DL detection limit

Notes ft feet

ND = Analyte not detected above the LOD. LOD values are presented in Appendix F. HQ hazard quotient

ID identification

LCMSMS liquid chromatography with tandem mass spectrometry

LOD limit of detection

ND analyte not detected above the LOD

OSD Office of the Secretary of Defense

QSM Quality Systems Manual

Qual interpreted qualifier

SB soil boring

USEPA United States Environmental Protection Agency

μg/kg micrograms per kilogram

a. Assistant Secretary of Defense, July 2022. Risk Based Screening Levels Calculated for PFOA, PFOS, PFBS, PFHxS, and PFNA in Groundwater or Soil using USEPA’s Regional

Screening Level Calculator. HQ=0.1, May 2022. Soil screening levels based on residential scenario for incidental ingestion of contaminated soil.

Area of Interest

Sample ID

Sample Date

Depth

AOI03-01-SB-00-02

02/15/2022

0-2 ft

AOI03

02/15/2022

0-2 ft

AOI03-03-SB-00-02

02/15/2022

0-2 ft

AOI03-05-SB-00-02

02/15/2022

0-2 ft

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

AOI03-04-SB-00-02

02/16/2022

0-2 ft

AOI03-04-SB-00-02-D

02/16/2022

0-2 ft

AOI03-02-SB-00-02

AECOM 6-8
Table 6-3

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

Site Inspection Report, Jefferson City AASF

Analyte OSD Screening 

Level a

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

PFBS 25000 0.046 J ND U ND U 0.089 J 0.308 J 0.081 J 0.044 J 0.032 J ND U ND U

PFHxS 1600 0.674 J ND U ND U 4.18 0.180 J 1.56 0.422 J 0.661 J 0.183 J 0.575 J

PFNA 250 ND U ND U ND U 0.105 J ND U 0.178 J ND U ND U ND U ND U

PFOA 250 0.094 J ND U ND U 0.210 J ND U 0.286 J 0.230 J ND U ND U ND U

PFOS 160 0.761 J ND U ND U 7.41 0.104 J 15.6 ND U 0.337 J 0.086 J 0.068 J

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

PFBS perfluorobutanesulfonic acid

References PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

PFOA perfluorooctanoic acid

PFOS perfluorooctanesulfonic acid

Interpreted Qualifiers Acronyms and Abbreviations

J = Estimated concentration AASF Army Aviation Support Facility

U = The analyte was not detected at a level greater than or equal to the adjusted DL AOI Area of Interest

DL detection limit

Notes ft feet

ND = Analyte not detected above the LOD. LOD values are presented in Appendix F. HQ hazard quotient

ID identification

LCMSMS liquid chromatography with tandem mass spectrometry

LOD limit of detection

ND analyte not detected above the LOD

OSD Office of the Secretary of Defense

QSM Quality Systems Manual

Qual interpreted qualifier

SB soil boring

USEPA United States Environmental Protection Agency

μg/kg micrograms per kilogram

a. Assistant Secretary of Defense, July 2022. Risk Based Screening Levels Calculated for PFOA, PFOS, PFBS, PFHxS, and PFNA in Groundwater or Soil using 

USEPA’s Regional Screening Level Calculator. HQ=0.1, May 2022. Soil screening levels based on industrial/commercial composite worker scenario for incidental

ingestion of contaminated soil.

AOI01 AOI02 AOI03

AOI03-02-SB-06-07

02/15/2022

6-7 ft

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

AOI03-01-SB-08-09

02/15/2022

8-9 ft

AOI03-01-SB-13-14

02/15/2022

13-14 ft

AOI02-03-SB-12-13

02/16/2022

12-13 ft

AOI02-04-SB-11-12

02/18/2022

11-12 ft

AOI02-01-SB-10-11

02/17/2022

10-11 ft

AOI02-02-SB-09-10

02/16/2022

9-10 ft

AOI01-02-SB-08-09

02/16/2022

8-9 ft

AOI01-03-SB-12-13

02/14/2022

12-13 ft

Area of Interest

Sample ID

Sample Date

Depth

AOI01-01-SB-08-09

2/16/2022

8-9 ft

AECOM 6-9
Table 6-3

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

Site Inspection Report, Jefferson City AASF

Analyte OSD Screening 

Level a

Result Qual Result Qual

PFBS 25000 ND U ND U

PFHxS 1600 0.156 J 0.068 J

PFNA 250 0.038 J 0.039 J

PFOA 250 0.119 J ND U

PFOS 160 2.29 6.74

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

PFBS perfluorobutanesulfonic acid

References PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

PFOA perfluorooctanoic acid

PFOS perfluorooctanesulfonic acid

Interpreted Qualifiers Acronyms and Abbreviations

J = Estimated concentration AASF Army Aviation Support Facility

U = The analyte was not detected at a level greater than or equal to the adjusted DL AOI Area of Interest

D duplicate

Notes DL detection limit

ND = Analyte not detected above the LOD. LOD values are presented in Appendix F. ft feet

HQ hazard quotient

ID identification

LCMSMS liquid chromatography with tandem mass spectrometry

LOD limit of detection

ND analyte not detected above the LOD

OSD Office of the Secretary of Defense

QSM Quality Systems Manual

Qual interpreted qualifier

SB soil boring

USEPA United States Environmental Protection Agency

μg/kg micrograms per kilogram

a. Assistant Secretary of Defense, July 2022. Risk Based Screening Levels Calculated for PFOA, PFOS, PFBS, PFHxS, and PFNA in Groundwater or Soil using 

USEPA’s Regional Screening Level Calculator. HQ=0.1, May 2022. Soil screening levels based on industrial/commercial composite worker scenario for incidental

AOI03

AOI03-03-SB-10-11

02/15/2022

10-11 ft

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

Area of Interest

Sample ID

Sample Date

Depth

AOI03-03-SB-07-08

02/15/2022

7-8 ft

AECOM 6-10
Table 6-4

PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Deep Subsurface Soil

Site Inspection Report, Jefferson City AASF

Area of Interest

Sample ID

Sample Date

Depth

Analyte Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual

PFBS ND U 0.094 J ND U ND U 0.047 J 0.159 J ND U

PFHxS ND U 0.580 J 0.278 J 0.383 J 0.109 J ND U 0.604 J

PFNA ND U ND U 1.12 ND U ND U ND U ND U

PFOA ND U ND U 0.246 J 0.146 J ND U ND U 0.101 J

PFOS 0.102 J ND U 23.7 1.69 ND U ND U 0.698 J

Interpreted Qualifiers Chemical Abbreviations

J = Estimated concentration PFBS perfluorobutanesulfonic acid

U = The analyte was not detected at a level greater than or equal to the adjusted DL PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

Notes PFOA perfluorooctanoic acid

ND = Analyte not detected above the LOD. LOD values are presented in Appendix F. PFOS perfluorooctanesulfonic acid

Acronyms and Abbreviations

AASF Army Aviation Support Facility

AOI Area of Interest

DL detection limit

ft feet

ID identification

LCMSMS liquid chromatography with tandem mass spectrometry

LOD limit of detection

ND analyte not detected above the LOD

QSM Quality Systems Manual

Qual interpreted qualifier

SB soil boring

μg/kg micrograms per kilogram

AOI02-04-SB-24-25

02/18/2022

24-25 ft

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

AOI01 AOI02

AOI02-02-SB-17-18

02/16/2022

17-18 ft

AOI02-03-SB-22-23

02/16/2022

22-23 ft

AOI01-03-SB-23-24

02/14/2022

23-24 ft

AOI02-01-SB-21.5-22.5

02/17/2022

21.5-22.5 ft

AOI01-01-SB-24-25

02/16/2022

24-25 ft

AOI01-02-SB-15-16

02/16/2022

15-16 ft

AECOM 6-11
Table 6-4

PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Deep Subsurface Soil

Site Inspection Report, Jefferson City AASF

Area of Interest

Sample ID

Sample Date

Depth

Analyte Result Qual

PFBS ND U

PFHxS 0.110 J

PFNA ND U

PFOA ND U

PFOS ND U

Interpreted Qualifiers Chemical Abbreviations

J = Estimated concentration PFBS perfluorobutanesulfonic acid

U = The analyte was not detected at a level greater than or equal to the adjusted DL PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

Notes PFOA perfluorooctanoic acid

ND = Analyte not detected above the LOD. LOD values are presented in Appendix F. PFOS perfluorooctanesulfonic acid

Acronyms and Abbreviations

AASF Army Aviation Support Facility

AOI Area of Interest

DL detection limit

ft feet

ID identification

LCMSMS liquid chromatography with tandem mass spectrometry

LOD limit of detection

ND analyte not detected above the LOD

QSM Quality Systems Manual

Qual interpreted qualifier

SB soil boring

μg/kg micrograms per kilogram

AOI03

AOI03-02-SB-16-16.75

02/15/2022

16-16.75 ft

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

AECOM 6-12
Table 6-5

PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Groundwater

Site Inspection Report, Jefferson City AASF

Analyte OSD Screening 

Level a

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

PFBS 601 187 495 22.0 22.6 0.685 J 126 148 206 47.5

PFHxS 39 4060 3090 404 423 ND U 582 669 1180 742

PFNA 6 189 27.5 389 401 ND U 11.3 14.0 11.5 147

PFOA 6 454 729 178 181 ND U 138 157 158 437

PFOS 4 8370 282 11700 12700 1.97 J 2630 3130 101 2630

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

PFBS perfluorobutanesulfonic acid

References PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

PFOA perfluorooctanoic acid

PFOS perfluorooctanesulfonic acid

Interpreted Qualifiers Acronyms and Abbreviations

J = Estimated concentration AASF Army Aviation Support Facility

U = The analyte was not detected at a level greater than or equal to the adjusted DL AOI Area of Interest

D duplicate

Notes DL detection limit

ND = Analyte not detected above the LOD. LOD values are presented in Appendix F. GW groundwater

HQ hazard quotient

ID identification

LCMSMS liquid chromatography with tandem mass spectrometry

LOD limit of detection

ND analyte not detected above the LOD

OSD Office of the Secretary of Defense

QSM Quality Systems Manual

Qual interpreted qualifier

USEPA United States Environmental Protection Agency

ng/l nanogram per liter

AOI01-02A-GW

02/19/2022

AOI01-03A-GW

02/19/2022

Area of Interest

Sample ID

Sample Date

AOI01-01-GW

02/16/2022

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

a. Assistant Secretary of Defense, July 2022. Risk Based Screening Levels Calculated for PFOA, PFOS, PFBS, PFHxS, and PFNA in Groundwater or Soil using 

USEPA’s Regional Screening Level Calculator. HQ=0.1, May 2022 Groundwater screening levels based on residential scenario for direct ingestion of groundwater.

AOI01 AOI02

AOI02-03-GW

02/16/2022

AOI02-04-GW

02/18/2022

AOI02-01-GW

02/18/2022

AOI02-01-GW-D

02/18/2022

AOI01-03A-GW-D

02/19/2022

AOI01-05-GW

02/15/2022

AECOM 6-13
Table 6-5

PFOA, PFOS, PFBS, PFNA, and PFHxS Results in Groundwater

Site Inspection Report, Jefferson City AASF

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual Result Qual

PFBS 601 9.57 41.1 29.8 17.2

PFHxS 39 526 181 156 119

PFNA 6 26.4 ND U ND U 8.67

PFOA 6 156 5.20 ND U 31.3

PFOS 4 1250 3.20 J 0.911 J 1190

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

PFBS perfluorobutanesulfonic acid

References PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

PFOA perfluorooctanoic acid

PFOS perfluorooctanesulfonic acid

Interpreted Qualifiers Acronyms and Abbreviations

J = Estimated concentration AASF Army Aviation Support Facility

U = The analyte was not detected at a level greater than or equal to the adjusted DL AOI Area of Interest

D duplicate

Notes DL detection limit

ND = Analyte not detected above the LOD. LOD values are presented in Appendix F. GW groundwater

HQ hazard quotient

ID identification

LCMSMS liquid chromatography with tandem mass spectrometry

LOD limit of detection

ND analyte not detected above the LOD

OSD Office of the Secretary of Defense

QSM Quality Systems Manual

Qual interpreted qualifier

USEPA United States Environmental Protection Agency

ng/l nanogram per liter

AOI03-03-GW

02/15/2022

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

a. Assistant Secretary of Defense, July 2022. Risk Based Screening Levels Calculated for PFOA, PFOS, PFBS, PFHxS, and PFNA in Groundwater or Soil using 

USEPA’s Regional Screening Level Calculator. HQ=0.1, May 2022 Groundwater screening levels based on residential scenario for direct ingestion of groundwater.

AOI03

AOI03-01-GW

02/16/2022

AOI03-02-GW

02/15/2022

Area of Interest

Sample ID

Sample Date

AOI02

AOI02-05-GW

02/16/2022

AECOM 6-14
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 6-15

THIS PAGE INTENTIONALLY BLANK
AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI01-04 AOI02-02 AOI03-04

AOI02-03

AOI02-04

AOI03-05

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI02-02

AOI02-03

AOI02-04

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI02-02

AOI02-03

AOI02-04

12420 Milestone Center Drive

Germantown, MD 20876 Figure 6-1

PFOA Detections in Soil

10/5/2022

10/5/2022

MS 10/5/2022

MB

CM

GIS BY

CHK BY

PM

10/5/2022

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Jefferson City AASF, MO

Base Map: Source: Esri, Maxar, Earthstar Geographics, and

the GIS User Community

­

1:2,400

0 100 200 400

Feet

Shallow

Intermediate

Deep

Exceedances of the OSD SL are depicted with a yellow halo.

Depth intervals shown represent respective sampling position within a given soil boring location.

Facility Boundary PFOA Results (μg/Kg)

ND

>ND - 19

>19 - 250

>250 - 2,500

>2,500

AECOM 6-16
AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI01-04 AOI02-02 AOI03-04

AOI02-03

AOI02-04

AOI03-05

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI02-02

AOI02-03

AOI02-04

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI02-02

AOI02-03

AOI02-04

12420 Milestone Center Drive

Germantown, MD 20876 Figure 6-2

PFOS Detections in Soil

5/19/2023

5/19/2023

MS 5/19/2023

MB

CM

GIS BY

CHK BY

PM

5/19/2023

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Jefferson City AASF, MO

Base Map: Source: Esri, Maxar, Earthstar Geographics, and

the GIS User Community

­ 1:2,400

0 100 200 400

Feet

Shallow

Intermediate

Deep

Exceedances of the OSD SL are depicted with a yellow halo.

Depth intervals shown represent respective sampling position within a given soil boring location.

Facility Boundary PFOS Results (μg/Kg)

ND

>ND - 13

>13 - 160

>160 - 1,600

>1,600

AECOM 6-17
AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI01-04 AOI02-02 AOI03-04

AOI02-03

AOI02-04

AOI03-05

Facility Boundary

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI02-02

AOI02-03

AOI02-04

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI02-02

AOI02-03

AOI02-04

12420 Milestone Center Drive

Germantown, MD 20876 Figure 6-3

PFBS Detections in Soil

5/19/2023

5/19/2023

MS 5/19/2023

MB

CM

GIS BY

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5/19/2023

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REVISED

SCALE

PROJECT

ARNG

Site Inspection at Jefferson City AASF, MO

Base Map: Source: Esri, Maxar, Earthstar Geographics, and

the GIS User Community

­ 1:2,400

0 100 200 400

Feet

Shallow

Intermediate

Deep

Exceedances of the OSD SL are depicted with a yellow halo.

Depth intervals shown represent respective sampling position within a given soil boring location.

PFBS Results (μg/Kg)

ND

>ND - 10

>10 - 1,900

>1,900 - 25,000

>25,000

AECOM 6-18
AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI01-04 AOI02-02 AOI03-04

AOI02-03

AOI02-04

AOI03-05

Facility Boundary

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI02-02

AOI02-03

AOI02-04

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI02-02

AOI02-03

AOI02-04

12420 Milestone Center Drive

Germantown, MD 20876 Figure 6-4

PFHxS Detections in Soil

10/5/2022

10/5/2022

MS 10/5/2022

MB

CM

GIS BY

CHK BY

PM

10/5/2022

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REVISED

SCALE

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ARNG

Site Inspection at Jefferson City AASF, MO

Base Map: Source: Esri, Maxar, Earthstar Geographics, and

the GIS User Community

­ 1:2,400

0 100 200 400

Feet

Shallow

Intermediate

Deep

Exceedances of the OSD SL are depicted with a yellow halo.

Depth intervals shown represent respective sampling position within a given soil boring location.

PFHxS Results (μg/Kg)

ND

>ND - 10

>10 - 130

>130 - 1,600

>1,600

AECOM 6-19
AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI01-04 AOI02-02 AOI03-04

AOI02-03

AOI02-04

AOI03-05

Facility Boundary

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI02-02

AOI02-03

AOI02-04

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI02-02

AOI02-03

AOI02-04

12420 Milestone Center Drive

Germantown, MD 20876 Figure 6-5

PFNA Detections in Soil

10/5/2022

10/5/2022

MS 10/5/2022

MB

CM

GIS BY

CHK BY

PM

10/5/2022

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REVISED

SCALE

PROJECT

ARNG

Site Inspection at Jefferson City AASF, MO

Base Map: Source: Esri, Maxar, Earthstar Geographics, and

the GIS User Community

­ 1:2,400

0 100 200 400

Feet

Shallow

Intermediate

Deep

Exceedances of the OSD SL are depicted with a yellow halo.

Depth intervals shown represent respective sampling position within a given soil boring location.

PFNA Results (μg/Kg)

ND

>ND - 19

>19 - 250

>250 - 2,500

>2,500

AECOM 6-20
AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI01-05

AOI02-03

AOI02-04

AOI02-05

Facility Boundary

Groundwater Flow Direction

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI01-05

AOI02-03

AOI02-04

AOI02-05

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI01-05

AOI02-03

AOI02-04

AOI02-05

12420 Milestone Center Drive

Germantown, MD 20876 Figure 6-6

PFOA, PFOS, and PFBS Detections

in Groundwater

10/5/2022

10/5/2022

MS 10/5/2022

MB

CM

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REVISED

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ARNG

Site Inspection at Jefferson City AASF, MO

Base Map: Source: Esri, Maxar, Earthstar Geographics, and

the GIS User Community

­ 1:2,400

0 100 200 400

Feet

PFOA

PFOS

PFBS

Exceedances of the OSD SL are depicted with a yellow halo.

PFOA Results (ng/L)

ND

>ND - 6

>6 - 40

>40 - 70

>70

PFOS Results (ng/L)

ND

>ND - 4

>4 - 40

>40 - 70

>70

PFBS Results (ng/L)

ND

>ND - 100

>100 - 601

>601 - 2,000

>2,000

AECOM 6-21
AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI01-05

AOI02-03

AOI02-04

AOI02-05

Facility Boundary

Groundwater Flow Direction

AOI01-01

AOI01-03/03A

AOI02-01

AOI03-01

AOI03-03

AOI03-02

AOI01-02/02A

AOI01-05

AOI02-03

AOI02-04

AOI02-05

12420 Milestone Center Drive

Germantown, MD 20876 Figure 6-7

PFHxS and PFNA Detections

in Groundwater

10/5/2022

10/5/2022

MS 10/5/2022

MB

CM

GIS BY

CHK BY

PM

10/5/2022

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Jefferson City AASF, MO

Base Map: Source: Esri, Maxar, Earthstar Geographics, and

the GIS User Community

­ 1:2,400

0 100 200 400

Feet

PFHxS

PFNA

Exceedances of the OSD SL are depicted with a yellow halo.

PFHxS Results (ng/L)

ND

>ND - 39

>39 - 100

>100 - 1,000

>1,000

PFNA Results (ng/L)

ND

>ND - 6

>6 - 100

>100 - 1,000

>1,000

AECOM 6-22
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 7-1

7. Exposure Pathways

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

Figure 7-3. 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 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:

1. Contaminant source;

2. Environmental fate and transport;

3. Exposure point;

4. Exposure route; and

5. Potentially exposed populations.

If any of these elements are missing, the pathway is incomplete. The CSM figures use an empty 

circle symbol to represent an incomplete exposure pathway. Areas with an incomplete pathway 

generally warrant no further action. However, the pathway is considered potentially complete if the 

relevant compounds 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 relevant 

compounds above the SLs. Areas with an identified potentially complete pathway that have 

detections of the relevant compounds above the SLs may warrant further investigation. Although 

the CSMs indicate whether potentially complete exposure pathways may exist, the 

recommendation for future study in an RI or no action at this time is based on the comparison of 

the SI analytical results for the relevant compounds to the SLs.

In general, the potential routes of exposure to the relevant compounds 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 toxicological study. The receptors 

evaluated are consistent with those listed in USEPA guidance for risk screening (USEPA, 2001). 

Receptors at the facility include site workers (e.g., facility staff and visiting soldiers), construction 

workers, trespassers (though unlikely due to restricted access), residents outside the facility 

boundary, and recreational users outside of the facility boundary.

7.1 Soil Exposure Pathway

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

between the source and potential receptors at AOI 1, AOI 2, and AOI 3 based on the 

aforementioned criteria.

7.1.1 AOI 1

AOI 1 is the West Ramp Nozzle Testing, Firetruck Storage, and AFFF Storage, where firetruck 

nozzle testing was conducted annually at the west ramp area as early as 1985 until 2002.

In the surface soil, PFOS was detected above the SL. Site workers and construction workers

could contact constituents in surface soil via incidental ingestion and inhalation of dust. Therefore, 
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 7-2

these surface soil exposure pathways for site workers and construction workers are potentially 

complete with exceedance of SL. In shallow subsurface soil, PFOA, PFOS, PFBS, and PFHxS 

were detected below the SLs, and PFNA was not detected. Construction workers could contact 

constituents in subsurface soil via incidental ingestion, and therefore, the subsurface soil 

exposure pathway for construction workers is potentially complete. The CSM for AOI 1 is 

presented on Figure 7-1.

7.1.2 AOI 2

AOI 2 is the Outdoor Wash Rack FTA and GSE Building, where controlled AFFF releases through 

familiarization training occurred annually potentially as early as 1992 until 2016. In 2019, AFFF 

from three Tri-Max30TM extinguishers was discharged to the ground at the wash rack. The units 

were refilled at the GSE building on the northwest side of the wash rack.

In the surface soil, PFOS was detected above the SL. Site workers and construction workers

could contact constituents in surface soil via incidental ingestion and inhalation of dust. Therefore, 

these surface soil exposure pathways for site workers and construction workers are potentially 

complete with exceedance of SL. In shallow subsurface soil, PFOA, PFOS, PFBS, PFHxS, and 

PFNA were detected below the SLs. Construction workers could contact constituents in 

subsurface soil via incidental ingestion, and therefore, the subsurface soil exposure pathway for 

construction workers is potentially complete. The CSM for AOI 2 is presented on Figure 7-2.

7.1.3 AOI 3

AOI 3 is the East Ramp Nozzle Testing, where firetruck nozzle testing was conducted annually at 

the east ramp area as early as 1985 until 2002.

In the surface soil, PFOS was detected above the SL. Site workers and construction workers

could contact constituents in surface soil via incidental ingestion and inhalation of dust. Therefore, 

these surface soil exposure pathways for site workers and construction workers are potentially 

complete with exceedance of SL. In shallow subsurface soil, PFOA, PFOS, PFBS, PFHxS, and 

PFNA were detected below the SLs. Construction workers could contact constituents in 

subsurface soil via incidental ingestion, and therefore, the subsurface soil exposure pathway for 

construction workers is potentially complete. The CSM for AOI 3 is presented on Figure 7-3.

7.2 Groundwater Exposure Pathway

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

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

7.2.1 AOI 1

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

SLs. An irrigation well is located 1.3 miles to the cross-gradient of the facility. Based on the 

gradient of the well in relation to the facility, the pathway for exposure to this well is considered 

incomplete. Because the location of Jefferson City groundwater wells that may serve the AASF 

are unknown, the pathway for exposure to site workers, residents, and recreational workers via 

ingestion of groundwater is considered potentially complete with exceedance of SL.

Groundwater was encountered at depths ranging between 23.89 to 27.06 feet bgs at AOI 1, with 

one additional location within a small runoff gully also measured at 4.48 feet bgs. The construction 

worker exposure scenario assumes excavation occurs at depths at or above 15 feet bgs. Based 

on the depths to groundwater encountered at AOI 1, the ingestion exposure pathway for future 
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 7-3

construction workers is considered potentially complete with exceedance of SL. The CSM for AOI 

1 is presented on Figure 7-1.

7.2.2 AOI 2

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

SLs. Because the location of Jefferson City groundwater wells that may serve the AASF are 

unknown, the pathway for exposure to site workers, residents, and recreational workers via 

ingestion of groundwater is considered potentially complete with exceedance of SL.

Groundwater was encountered at depths ranging between 15.56 to 27.19 at AOI 2. The 

construction worker exposure scenario assumes excavation occurs at depths at or above 15 feet 

bgs. Based on the depths to groundwater encountered at AOI 2, the ingestion exposure pathway 

for future construction workers is considered incomplete. The CSM for AOI 2 is presented on 

Figure 7-2.

7.2.3 AOI 3

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

SLs. Because the location of Jefferson City groundwater wells that may serve the AASF are 

unknown, the pathway for exposure to site workers, residents, and recreational workers via 

ingestion of groundwater is considered potentially complete with exceedance of SL.

Groundwater was encountered at depths ranging between 13.43 to 18.41 feet bgs at AOI 3. The 

construction worker exposure scenario assumes excavation occurs at depths at or above 15 feet 

bgs. Based on the depths to groundwater encountered at AOI 1, the ingestion exposure pathway 

for future construction workers is considered potentially complete with exceedance of SL. The 

CSM for AOI 3 is presented on Figure 7-3.

7.3 Surface Water and Sediment Exposure Pathway

The SI results in soil and groundwater, in combination with knowledge of the fate and transport 

properties of PFAS, were used to determine whether a potentially complete pathway exists 

between the source and potential receptors.

7.3.1 AOI 1, AOI 2, and AOI 3

Jefferson City is split by the Missouri River, separating Cole County to the south and Callaway 

County to the north. The AASF is less than 1 mile north and generally upgradient of the Missouri 

River.

PFAS are water soluble and can migrate readily from soil to surface water via leaching and runoff. Because PFOA, PFOS, PFHxS, PFNA, and PFBS were detected in soil and groundwater at 

all three AOIs, it is possible that these compounds may have migrated from soil and groundwater 

to downgradient Missouri River. Residential structures are located along the southern shoreline 

of the Missouri River, and the river is used for boating and fishing (Missouri Department of 

Conservation, 2022). Therefore, the surface water and sediment ingestion exposure pathway for

off-facility residents and recreational users is considered potentially complete. Ephemeral surface 

water bodies were observed at the facility; therefore, the exposure pathway for site workers and 

construction workers is considered potentially complete. The CSMs for AOI 1, AOI 2, and AOI 3 

are presented on Figure 7-1, Figure 7-2, and Figure 7-3, respectively.
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 7-4

THIS PAGE INTENTIONALLY BLANK
Media

SOURCE PATHWAY RECEPTOR

AOI 1

AFFF

Firetruck

Nozzle

Testing and

AFFF Storage

Subsurface

Soil

Human

Activities

Precipitation/

Run-Off

Leaching/

Infiltration

Airborne Soil

Particulate

Surface Soil

Surface

Water/

Sediment

Subsurface

Soil

Shallow

Groundwater

Source Release

Mechanism Media Transportand Migration Media ExposureRoutes

Inhalation of

Dust

Ingestion

Ingestion

Ingestion

Ingestion

Human Receptors:

Current/ Future

Flow-Chart Continues

Partial / Possible Flow

Flow-Chart Stops

Incomplete Pathway

Potentially Complete Pathway

Potentially Complete Pathway

with Exceedance of SL

LEGEND

Figure 7-1

Conceptual Site Model, AOI 1

Jefferson City AASF, Jefferson City, Missouri

Potential

Off-Facility

Source Not

Under

Control of

ARNG

Surface

Water

Surface

Water Flow

NOTES

1. The resident and recreational users refer

to off-site receptors.

Surface Soil

/ / / /

Site

Worker

Construction

Worker

Resident1

Recreational

User/Trespasser1

/ / / /

Site

Worker

Construction

Worker Resident1

/ / / /

Recreational

User/

Trespasser1

/ / / /

/ / / /

AECOM 7-5 
Media

SOURCE PATHWAY RECEPTOR

AOI 2

AFFF

Discharge

During Fire

Training

Activities

Surface Soil

Subsurface

Soil

Human

Activities

Precipitation/

Run-Off

Leaching/

Infiltration

Airborne Soil

Particulate

Surface Soil

Surface

Water/

Sediment

Subsurface

Soil

Shallow

Groundwater

Source Release

Mechanism Media Transportand Migration Media ExposureRoutes

Inhalation of

Dust

Ingestion

Ingestion

Ingestion

Ingestion

Human Receptors:

Current/ Future

Flow-Chart Continues

Partial / Possible Flow

Flow-Chart Stops

Incomplete Pathway

Potentially Complete Pathway

Potentially Complete Pathway

with Exceedance of SL

LEGEND

Figure 7-2

Conceptual Site Model, AOI 2

Jefferson City AASF, Jefferson City, Missouri

Potential

Off-Facility

Source Not

Under

Control of

ARNG

Surface

Water

Surface

Water Flow

NOTES

1. The resident and recreational users refer

to off-site receptors.

2. Groundwater was encountered at depths

greater than 15 feet bgs at AOI 2.

/ / / /

Site

Worker

Construction

Worker

Resident1

Recreational

User/Trespasser1

/ / / /

Site

Worker

Construction

Worker Resident1

/ / / /

Recreational

User/

Trespasser1

/ / / /

/ / / /

AECOM 7-6
Media

SOURCE PATHWAY RECEPTOR

AOI 3

AFFF

Firetruck

Nozzle

Testing

Surface Soil

Subsurface

Soil

Human

Activities

Precipitation/

Run-Off

Leaching/

Infiltration

Airborne Soil

Particulate

Surface Soil

Surface

Water/

Sediment

Subsurface

Soil

Shallow

Groundwater

Source Release

Mechanism Media Transportand Migration Media ExposureRoutes

Inhalation of

Dust

Ingestion

Ingestion

Ingestion

Ingestion

Human Receptors:

Current/ Future

Flow-Chart Continues

Partial / Possible Flow

Flow-Chart Stops

Incomplete Pathway

Potentially Complete Pathway

Potentially Complete Pathway

with Exceedance of SL

LEGEND

Figure 7-3

Conceptual Site Model, AOI 3

Jefferson City AASF, Jefferson City, Missouri

Potential

Off-Facility

Source Not

Under

Control of

ARNG

Surface

Water

Surface

Water Flow

NOTES

1. The resident and recreational users refer

to off-site receptors

/ / / /

Site

Worker

Construction

Worker

Resident1

Recreational

User/Trespasser1

/ / / /

Site

Worker

Construction

Worker Resident1

/ / / /

Recreational

User/

Trespasser1

/ / / /

/ / / /

AECOM 7-7
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 7-8

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Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 8-1

8. Summary and Outcome

This section summarizes SI activities and findings. The most significant findings are summarized 

in this section and are reproduced directly or abstracted from information contained in this report. 

The outcome provides general and comparative interpretations of the findings relative to the SLs.

8.1 SI Activities

The SI field activities were conducted from 14 to 19 February 2022 and consisted of utility clearance, 

direct push boring, soil sample collection, temporary monitoring well installation, grab groundwater 

sample collection, and land surveying. Field activities were conducted in accordance with the SI 

QAPP Addendum (AECOM, 2021), except as previously noted in Section 5.8.

To fulfill the project DQOs set forth in the approved SI QAPP Addendum (AECOM, 2021), samples 

were collected and analyzed for a subset of 18 compounds by LC/MS/MS compliant with QSM 5.3 

Table B-15 as follows.

• Thirty-three (33) soil samples from 15 boring locations;

• Eleven (11) grab groundwater samples from 12 temporary well locations;

• Twenty (20) QA/QC 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 AOIs 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 CSMs were refined to assess whether a potentially complete pathway 

exists between the source and potential receptors for potential exposure at the AOIs, which are 

described in Section 7.

8.2 Outcome

Based on the results of this SI, further evaluation is warranted in an RI for AOI 1: West Ramp 

Nozzle Testing, Firetruck Storage, and AFFF Storage; AOI 2: Outdoor Wash Rack FTA and GSE 

Building; and AOI 3: East Ramp Nozzle Testing. Based on the CSMs developed and revised in 

light of the SI findings, there is potential for exposure to drinking water receptors from AOI 1, AOI 

2, and AOI 3 from sources on the facility resulting from historical DoD activities. Sample analytical 

concentrations collected during the SI were compared to the project SLs in soil and groundwater, 

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

• At AOI 1:

• In surface soil, PFOS exceeded the SL of 13 μg/kg, with the maximum concentration 

of 75.2 μg/kg at AOI01-01. The detected concentrations of PFOA, PFBS, PFHxS, 

and PFNA in soil were below the SLs.

• PFOA, PFOS, PFHxS, and PFNA in groundwater exceeded their SLs. PFOA 

exceeded the SL of 6 ng/L, with the maximum concentration of 729 ng/L at AOI01-

02. PFOS exceeded the SL of 4 ng/L, with the maximum concentration of 12,700 

ng/L at AOI01-03A. PFHxS exceeded the SL of 39 ng/L, with the maximum 

concentration of 4,060 ng/L at AOI01-01. PFNA exceeded the SL of 6 ng/L, with the 

maximum concentration of 401 ng/L at AOI01-03A. PFBS in groundwater was below 

the SL.
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 8-2

• At AOI 2:

• In surface soil, PFOS exceeded the SL of 13 μg/kg, with the maximum concentration 

of 58.2 μg/kg at AOI02-04. The detected concentrations of PFOA, PFBS, PFHxS, 

and PFNA in soil were below the SLs.

• PFOA, PFOS, PFHxS, and PFNA in groundwater exceeded their SLs. PFOA 

exceeded the SL of 6 ng/L, with a maximum concentration of 437 ng/L at AOI02-04. 

PFOS exceeded the SL of 4 ng/L, with a maximum concentration of 3,130 ng/L at 

AOI02-01. PFHxS exceeded the SL of 39 ng/L, with a maximum concentration of 

1,180 ng/L at AOI02-03. PFNA exceeded the SL of 6 ng/L, with a maximum 

concentration of 147 ng/L at AOI02-04. PFBS in groundwater was below the SL.

• At AOI 3:

• PFOS exceeded the SL of 13 μg/kg in surface soil at one location, AOI03-03, with a 

concentration of 14.5 μg/kg. The detected concentrations of PFOA, PFBS, PFHxS, 

and PFNA in soil were below the SLs.

• PFOA, PFOS, PFHxS, and PFNA in groundwater exceeded their SLs. PFOA 

exceeded the SL of 6 ng/L at one location, AOI03-03, a concentration of 31.3 ng/L. 

PFOS exceeded the SL of 4 ng/L at one location, AOI03-03, at a concentration of 

1,190 ng/L. PFHxS exceeded the SL of 39 ng/L, with a maximum concentration of 

181 ng/L at AOI03-01. PFNA exceeded the SL of 6 ng/L at one location, AOI03-03, 

a concentration of 8.67 ng/L. PFBS in groundwater was below the SL.

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.
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 8-3

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

AOI Potential 

Release Area

Soil –

Source 

Area

Groundwater – 

Source Area

Groundwater – 

Facility Boundary

Future 

Action

1

West Ramp 

Nozzle Testing, 

Firetruck 

Storage, and 

AFFF Storage

Proceed 

to RI

2

Outdoor Wash 

Rack FTA and 

GSE Building

Proceed 

to RI 

3 East Ramp 

Nozzle Testing

Proceed 

to RI 

Legend:

= detected; exceedance of the screening levels

= detected; no exceedance of the screening levels

= not detected
Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 

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Site Inspection Report

Army Aviation Support Facility, Jefferson City, Missouri

AECOM 9-1

9. References

AECOM. 2018a. Final Site Inspection Programmatic Uniform Federal Policy-Quality Assurance

Project Plan, Perfluorooctane Sulfonic Acid (PFOS) and Perfluorooctanoic Acid (PFOA) 

Impacted Sites ARNG Installations, Nationwide Contract No. W912DR-12-D-0014/

W912DR17F0192. 9 March.

AECOM. 2018b. Final Programmatic Accident Prevention Plan, Perfluorooctane Sulfonic Acid 

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