FINAL

Preliminary Assessment Report

Austin Bergstrom Army Aviation 

Support Facility 

Austin, Texas

Perfluorooctanesulfonic Acid (PFOS) and Perfluorooctanoic 

Acid (PFOA) Impacted Sites

ARNG Installations, Nationwide

July 2020

Prepared for:

Army National Guard Bureau

111 S. George Mason Drive

Arlington, VA 22204

UNCLASSIFIED
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

i

Table of Contents

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

1. Introduction ........................................................................................................................ 5

1.1 Authority and Purpose .............................................................................................. 5

1.2 Preliminary Assessment Methods ............................................................................. 5

1.3 Report Organization .................................................................................................. 6

1.4 Facility Location and Description............................................................................... 6

1.5 Facility Environmental Setting ................................................................................... 6

1.5.1 Geology ......................................................................................................... 7

1.5.2 Hydrogeology ................................................................................................. 7

1.5.3 Hydrology ....................................................................................................... 8

1.5.4 Climate ........................................................................................................... 8

1.5.5 Current and Future Land Use ......................................................................... 8

2. Fire Training Areas ........................................................................................................... 12

3. Non-Fire Training Areas ................................................................................................... 13

3.1 Maintenance Hangar ............................................................................................... 13

3.2 Other Hangars ........................................................................................................ 13

3.3 Wash Rack Area ..................................................................................................... 14

3.4 Hazardous Materials Storage Building .................................................................... 14

3.5 Fuel Station ............................................................................................................ 14

4. Emergency Response Areas ............................................................................................ 16

5. Adjacent Sources ............................................................................................................. 18

5.1 Former Bergstrom AFB ........................................................................................... 18

5.2 ABIA Fire Station .................................................................................................... 19

5.3 Landfill .................................................................................................................... 19

6. Preliminary Conceptual Site Model .................................................................................. 21

6.1 Pathways ................................................................................................................ 21

6.2 Receptors ............................................................................................................... 21

6.3 AOI 1 Maintenance Hangar ..................................................................................... 22

6.4 AOI 2 Wash Rack ................................................................................................... 22

6.5 AOI 3 Fixed Wing Support Hangar and Storage Hangar ......................................... 22

6.6 AOI 4 Hazardous Materials Storage Building and Fuel Station ............................... 22

7. Conclusions ..................................................................................................................... 25

7.1 Findings .................................................................................................................. 25

7.2 Uncertainties ........................................................................................................... 26

7.3 Potential Future Actions .......................................................................................... 27

8. References ...................................................................................................................... 30
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

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Figures

Figure ES-1 Summary of Findings

Figure ES-2 Preliminary Conceptual Site Model for AOI 1, 2, 3 and 4

Figure 1-1 Facility Location

Figure 1-2 Groundwater Features

Figure 1-3 Surface Water Features

Figure 3-1 Non-Fire Training Areas

Figure 4-1 Emergency Response Area

Figure 5-1 Adjacent Sources

Figure 6-1 Areas of Interest

Figure 6-2 Preliminary Conceptual Site Model for AOI 1, 2, 3, and 4

Figure 7-1 Summary of Findings

Tables

Table ES-1: AOIs at Austin Bergstrom AASF

Table 7-1: AOIs at Austin Bergstrom AASF

Table 7-2: Uncertainties

Table 7-3: Rationale

Appendices

Appendix A Data Resources

Appendix B Preliminary Assessment Documentation

B.1 Interview Records

B.2 Visual Site Inspection Checklists

B.3 Conceptual Site Model Information

Appendix C Photographic Log
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

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Acronyms and Abbreviations

AASF Army Aviation Support Facility

ABIA Austin-Bergstrom International Airport

AECOM AECOM Technical Services, Inc.

AFFF aqueous film forming foam

AFB Air Force Base

AFRC Armed Forces Reserve Center

amsl above mean sea level

AOI area of interest

ARNG Army National Guard

bgs below ground surface

CERCLA Comprehensive Environmental Response, Compensation, and Liability

Act

CSM conceptual site model

EDRTM Environmental Data Resources, Inc.TM

oF degrees Fahrenheit

FAA Federal Aviation Administration

FTA fire training area

HA Health Advisory

JVMF Joint Vehicle Maintenance Facility

NOAA National Oceanic and Atmospheric Administration

OWS oil-water separator

PA Preliminary Assessment

PFAS per- and poly-fluoroalkyl substances

PFOA perfluorooctanoic acid

PFOS

ppt

perfluorooctanesulfonic acid

parts per trillion

RCP reinforced concrete pipe

SI Site Inspection

TWDB SDR Texas Water Development Board Submitted Drillers Reports

TXARNG Texas Army National Guard

UCMR3 Unregulated Contaminant Monitoring Rule 3

US United States

USACE United States Army Corps of Engineers

USEPA United States Environmental Protection Agency

USPFO United States Property & Fiscal Office

VSI visual site inspection

WWTP waste water treatment plant
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

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Executive Summary

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

Inspections (SIs) for Perfluorooctanesulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA)

Impacted Sites at ARNG Facilities Nationwide. A PA for per- and polyfluoroalkyl substances

(PFAS)-containing materials was completed for Austin Bergstrom Army Aviation Support Facility

(AASF) (also referred to as the “facility”) in Austin, Texas, to assess potential PFAS release areas

and exposure pathways to receptors. The performance of this PA included the following tasks:

· Reviewed available administrative record documents and Environmental Data Resources,

Inc. (EDR)TM report packages to obtain information relevant to potential PFAS releases, such

as: drinking water well locations, historical aerial photographs, Sanborn maps, and

environmental compliance actions in the area surrounding the facility;

· Conducted a 1-day site visit on 24 April 2019 and completed visual site inspections (VSIs) at

locations where PFAS-containing materials were suspected of being stored, used, or

disposed;

· Interviewed personnel associated with Austin Bergstrom AASF activities during the site visit

including Austin Bergstrom AASF Maintenance Officer (on site since 2001), Ground Support

Shop Chief (on site since 2002) and Environmental Specialist (on site since 2017);

· Identified Area(s) of Interest (AOIs) and developed a preliminary conceptual site model (CSM)

to summarize potential source-pathway-receptor linkages of potential PFAS in soil,

groundwater, surface water, and sediment for each AOI.

Four suspected PFAS releases were identified during the PA as described below. These releases

constitute four AOIs identified at Austin Bergstrom AASF. The AOIs are shown in Figure ES-1 and

summarized in Table ES-1 below.

Table ES-1: AOIs at Austin Bergstrom AASF

Area of

Interest Name Used by Release Dates

AOI 1 Two aqueous film forming foam (AFFF)

fire suppression system releases

occurred at the Maintenance Hangar.

Releases discharged to trench drains in

the hangar, which flowed to the below

ground holding tank, then to the oil-water

separator (OWS), and then either to the

storm water drainage system (first test

release) or to frac tanks for holding

(second accidental release).

TXARNG 2005-2006

AOI 2 Releases occurred during AFFF fire

extinguisher testing/training with mobile

carts at the wash rack. AFFF travelled

from the wash rack to either the holding

tank, then to the OWS, then to the storm

water drainage system, or from the wash

rack to the oil/sand filter and then to the

sanitary sewer system, depending on the

positioning of a diverter valve. Water in

TXARNG 2009
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

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Area of

Interest Name Used by Release Dates

the storm water drainage system travelled

to the retention ponds.

AOI 3 The Fixed Wing Support Hangar and the

Storage Hangar are both equipped with

AFFF fire suppression systems. It is likely

that both systems were tested in 2005,

when the hangars were being

commissioned, leading to a release of

AFFF. The flow path for AFFF foam would

have been from the hangar to the trench

drain, then to the holding tank, then to the

OWS, and finally to the storm water

drainage system, which discharges to the

retention ponds.

TXARNG 2005

AOI 4 The Hazardous Materials Storage

Building and the Fuel Station both

historically contained AFFF in 5-gallon

containers and in Tri-MaxTM units

(respectively). These areas will be

investigated for potential PFAS release.

TXARNG 2005-2014

Based on the reported AFFF releases at these AOIs, there is potential for exposure to PFAS

contamination in media at or near the facility. The preliminary CSM for the Austin Bergstrom AASF

is shown on Figure ES-2. Based on the United States Environmental Protection Agency (USEPA)

Unregulated Contaminant Monitoring Rule 3 (UCMR3) data, it was indicated that no PFAS were

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

facility. PFAS analyses performed in 2016 had method detection limits that were higher than

currently achievable. Thus, it is possible that low concentrations of PFAS were not detected during

the UCMR3 but might be detected if analyzed today.
Storage Hangar

Wash Rack

Maintenance Hangar

Fuel Station

Hazardous Materials

Storage Building Fixed Wing

Support Hangar

Former Bergstrom AFB 

Fire Training Pit

Location

of 2002

Aircraft Fire

Former AFB

Building 201

(Fire Station)

Former AFB

Building 203 (Fire

Station Wash Rack)

Former AFB STO-604

and Former AFB

Building 604

Former AFB Discharge

Detention Basin

Former AFB

Hangar 1608

and STOR-1608

Former AFB

Hangar 1609

Building 4577

Austin Fire

Department

Travis

County

Landfill

Armed Forces 

Reserve Center

Joint Vehicle

Maintenance Facility

Joint Vehicle 

Maintenance Facility Complex Pond

Armed Forces

Reserve Center Pond

Holding Tank

AOI 3

AOI 2

AOI 1

AOI 3

AOI 4

Approximate Austin

Bergstrom International

Airport Boundary

Cotton m outh Cr eek

Carso nCreek

Onion Creek

Colorado River

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

MC

4/27/2020

4/27/2020

NOTES Preliminary Assessment for PFAS at Bergstrom AASF, TX

1:28,800

4/27/2020 ­ Figure ES-1 PM RG 4/27/2020

12420 Milestone Center Drive

Germantown, MD 20876

Summary of Findings

Base Map: Source: Esri, DigitalGlobe, GeoEye,

Earthstar Geographics, CNES/Airbus DS, USDA, USGS,

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\TX\Bergstrom_PA_Figures\Fig_ES-1_Bergstrom_AASF_Summary.mxd

0 1,200 2,400 4,800

Feet

Legend

Area of Interest

Potential PFAS Release

No Suspected Release

Facility Boundary

Water Body

Stream/River

3
Media

SOURCE PATHWAY RECEPTOR

AOI 1

AOI 2

AOI 3

AOI 4

AFFF Release

during testing and

accidental triggering

of the AFFF fire

suppression

systems, and during

AFFF fire

extinguisher testing/

training. Potential

release from AFFF

storage areas.

PFAS in

Surface Soil

PFAS in

Subsurface

Soil via

infiltration at

Retention

Ponds

Human

Activities

Leaching/

Infiltration

Airborne Soil

particulate

Surface Soil

at AOI

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

Complete Pathway

Site

Worker

Construction

Worker Resident Trespasser/Recreational User

Site

Worker

Construction

Worker Resident Trespasser/

Recreational User

/ / /

/ /

LEGEND

/ /

/ / /

Figure ES-2

Preliminary Conceptual Site Model

Austin Bergstrom AASF

Potential

Off-Facility

Source Not

under

Control of

ARNG

/

/

/

/

/

/ /

/

/

Note:

1. The residential receptor

refers to an off-facility

receptor.

/

Precipitation/

Run-Off

4
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

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1. Introduction

1.1 Authority and Purpose

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

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

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

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

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

Order W912DR17F0192, issued 11 August 2017.

The ARNG is assessing potential effects on human health related to processes at their facilities

that used per- and poly-fluoroalkyl substances (PFAS), primarily releases of aqueous film forming

foam (AFFF) although other sources of PFAS are possible. In addition, the ARNG is assessing

businesses or operations adjacent to the ARNG facility (not under the control of ARNG) that could

potentially be responsible for a PFAS release.

PFAS are classified as emerging environmental contaminants that are garnering increasing

regulatory interest due to their potential risks to human health and the environment. The regulatory

framework at both federal and state levels continues to evolve. The US Environmental Protection

Agency (USEPA) issued lifetime drinking water Health Advisories (HAs) for PFOA and PFOS in

May 2016, but there are currently no promulgated national standards regulating PFAS in drinking

water.

This report presents findings of a PA for PFAS-containing materials at Austin Bergstrom Army

Aviation Support Facility (AASF) (also referred to as “the facility”) in Austin, Texas, in accordance

with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA),

as amended, the National Oil and Hazardous Substances Pollution Contingency Plan (40 Code

of Federal Regulations Part 300), and Army requirements and guidance.

This PA documents the locations where PFAS were historically stored and reportedly released

into the environment at Austin Bergstrom AASF. The term PFAS will be used throughout this report

to encompass all PFAS chemicals being evaluated, including PFOS and PFOA, which are key

components of AFFF.

1.2 Preliminary Assessment Methods

The performance of this PA included the following tasks:

· Reviewed available administrative record documents and Environmental Data Resources,

Inc. (EDR)TM report packages to obtain information relevant to potential PFAS releases, such

as: drinking water well locations, historical aerial photographs, Sanborn maps, and

environmental compliance actions in the area surrounding the facility;

· Conducted a 1-day site visit on 24 April 2019 and completed visual site inspections (VSIs) at

locations where PFAS-containing materials were suspected of being stored, used, or

disposed;

· Interviewed personnel associated with Austin Bergstrom AASF activities during the site visit

including Austin Bergstrom AASF Maintenance Officer (on site since 2001), Ground Support

Shop Chief (on site since 2002) and Environmental Specialist (on site since 2017);
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

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· Identified Area(s) of Interest (AOIs) and developed a preliminary conceptual site model

(CSM) to summarize potential source-pathway-receptor linkages of potential PFAS in soil,

groundwater, surface water, and sediment for each AOI.

1.3 Report Organization

This report has been prepared in accordance with the USEPA Guidance for Performing

Preliminary Assessments under CERCLA (USEPA, 1991). The report sections and descriptions

of each are:

· Section 1 – Introduction: identifies the project purpose and authority and describes the

facility location, environmental setting, and methods used to complete the PA

· Section 2 – Fire Training Areas: describes the potential or suspected fire training areas

(FTAs) at the facility identified during the site visit

· Section 3 – Non-Fire Training Areas: describes other locations of potential or suspected

PFAS releases at the facility identified during the site visit

· Section 4 – Emergency Response Areas: describes areas of suspected or potential AFFF

release at the facility, specifically in response to emergency situations

· Section 5 – Adjacent Sources: describes sources of PFAS release adjacent to the facility

that are not under the control of ARNG

· Section 6 – Preliminary Conceptual Site Model: describes the pathways of PFAS transport

and receptors at the AOIs

· Section 7 – Conclusions: summarizes the data findings and presents the conclusions of the

PA

· Section 8 – References: provides the references used to develop this document

· Appendix A – Data Resources

· Appendix B – Preliminary Assessment Documentation

· Appendix C – Photographic Log

1.4 Facility Location and Description

Austin Bergstrom AASF, home to the Texas ARNG (TXARNG), is located within the southwest

portion of the Austin-Bergstrom International Airport (ABIA) in Austin, Texas. The installation is

located 8 miles southeast of downtown Austin and is situated at the intersection of Burleson Road

and Emma Browning Avenue (Figure 1-1). As noted in the lease agreement (Appendix A), the

TXARNG leases approximately 57 acres of land at ABIA. The facility consists of three hangars (a

Fixed Wing Support Hangar, Maintenance Hangar, and a Storage Hangar), which were built in

2003-2004, as well as a Joint Vehicle Maintenance Facility and an Armed Forces Reserve Center,

which were built in 2011-2012. The Austin Bergstrom AASF is tasked with providing hangar,

administrative, and supply and maintenance shop spaces to service aircraft, serve peacetime

missions, and perform the necessary tasks that improve the units’ readiness.

1.5 Facility Environmental Setting

Austin Bergstrom AASF is located in central Texas, approximately 150 miles northwest of the Gulf

of Mexico. The facility is situated approximately 2.8 miles southwest of the Colorado River, with

Onion Creek running along the southern boundary. The facility is located at approximately 500
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

7

feet above sea level, and the soil on site is described as silty clay with moderate infiltration rates

(Environmental Data Resources, Inc. [EDRTM], 2019).

1.5.1 Geology

Austin is located along the Balcones Fault Zone, with the physiographic provinces of the Edwards

Plateau to the west, and the Backland Prairie to the east. The regional geology consists of

Quaternary terrace deposits over Cretaceous sedimentary bedrock (Young, 1977).

The facility lies entirely on the Late Pleistocene Lower Colorado River Terrace Deposits overlying

the upper Cretaceous Taylor Group. The Lower Colorado Terrace Deposits are composed of sand

silt, clay, and gravel up to 60 feet thick. The Taylor Group (Taylor Clay) is a greenish gray to

brownish gray montmorillonitic clay that is highly expansive, makes a good aquiclude, and totals

about 700 feet thick (Bureau of Economic Geology, 1976).

1.5.2 Hydrogeology

The primary aquifer in the Austin area and under the facility is the Edwards Aquifer, which is shown

to be at about 500 feet below ground surface (bgs). The Trinity Aquifer is about 1500 feet bgs

(Bureau of Economic Geology, 1976).

The Trinity Aquifer extends across much of the central and northeastern part of the state and is

composed of several smaller aquifers contained within the Trinity Group. These aquifers consist

of limestones, sands, clays, gravels, and conglomerates. The Trinity Aquifer is one of the most

extensive and highly used groundwater resources in Texas. Although its primary use is for

municipalities, it is also used for irrigation, livestock, and other domestic purposes. The Trinity

aquifer subcrop is a subsurface area (the part of the aquifer that lies or dips below other

formations). Confined aquifers of this type are overlain by confining units, such as clay and shale

layers that do not readily transmit groundwater and are typically well below the land surface (Texas

Water Development Board, 2011).

The main concern at Austin Bergstrom AASF is the shallow unconfined aquifer in the terrace

deposits. The wells near the facility are likely in shallow terrace or alluvial deposits. Groundwater

in the shallow fluviatile terrace deposits aquifer is present at a depth of approximately 20 and 25

feet bgs, with recharge primarily occurring through percolation from the surface and through

stream channels. Groundwater flow in the shallow aquifer has been measured to the east and

southeast at FT023P, a fire training area operated by the former Bergstrom Air Force Base (AFB)

and located approximately 1 mile north of the facility (Amec Foster Wheeler, 2016). A groundwater

gradient determination was conducted at the former Bergstrom AFB in 1995 and found that

groundwater flows to the south-southeast at the Austin Bergstrom AASF. The variation in flow

direction in the vicinity of the facility is considered to be primarily related to the thickness of the

terrace deposits above the Taylor marl (Law Environmental, Inc., 1995) (Figure 1-2).

The facility obtains its drinking water from the City of Austin. A query of the Texas Water

Development Board Submitted Driller’s Reports (TWDB SDR) Database identified 1 industrial

water supply well, 4 domestic wells, and 27 monitoring wells within a 1-mile radius of the facility.

The industrial water supply well is 35 feet deep and is located southeast of the facility. The four

domestic wells are located between 0.3 and 0.6 miles northeast and southeast of the facility and

range from 35 to 70 feet deep. The majority of the monitoring wells are located to the south of the

facility, along the perimeter of the Travis County Landfill. Additionally, there are four monitoring

wells to the northwest of the facility that are owned by Sunland Group. The monitoring wells are

between 26 and 121.5 feet deep. Based on the USEPA Unregulated Contaminant Monitoring Rule

3 (UCMR3) data, it was indicated that no PFAS were detected in a public water system above the

HA within 20 miles of the facility. PFAS analyses performed in 2016 had method detection limits
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

8

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

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

1.5.3 Hydrology

After reviewing the Site Topography and Storm Water Drainage System, Figure 4-2 from ABIA

(ABIA, 2019) and the engineering drawings of the 24 inch and 30 inch reinforced concrete pipe

(RCP) Discharge Outlet Plans (Jose I. Guerra, Inc., 2010), it was determined that surface water

that collects on the paved area to the west of the Maintenance Hangar flows via large diameter

underground piping south to the holding tank and oil-water separator (OWS) (Figure 1-3). Water

then flows to the northeast, where it joins with other storm water from contributing portions of the

north side of the facility. The comingled storm water then travels through underground piping to

the Joint Vehicle Maintenance Facility (JVMF) Complex Pond. The JVMF Complex Pond consists

of a water quality pond and a retention pond. After the storm water moves through the retention

pond, it flows southwest through underground piping to the Armed Forces Reserve Center (AFRC)

Pond. From the AFRC Pond, storm water from light rain events flowed to Outfall #2, which is

located to the east of General Aviation Avenue. At Outfall #2, storm water was discharged and

allowed to infiltrate into the subsurface. However, this outfall was capped and removed from

service in 2018. During heavier rain events, water flows to Outfall #1, located south of Burleson

Road, and is discharged to Onion Creek. Although rainwater may have carried contaminates to

Outfalls #1 and #2, it is more likely that AFFF release events resulted in contaminants collecting

in the JVMF Complex Pond and the AFRC Pond and penetrating into the subsurface in these two

areas.

In addition, it was determined from on-site interviews that wastewater that collects in the wash

rack either flows to the storm water drainage system (described above) or flows through an

oil/sand filter and then discharges to the sanitary sewer system. The position of the diverter valve

at the wash rack determines whether wastewater flow travels to the storm water drainage system

or to the sanitary sewer.

1.5.4 Climate

The climate of Austin is humid subtropical, with hot summers and mild winters, and with warm

spring and fall transitional periods. Temperatures reach their peak in August, with normal highs

ranging from 93 degrees Fahrenheit (°F) to 102°F in 2019, and lows averaging 75°F. Austin

experienced around 36 inches of rainfall in 2018, with March, September, and December being

the wettest months of the year (National Weather Service Forecast Office, 2019). Precipitation in

the spring and summer usually results from thunderstorms (National Oceanic and Atmospheric

Administration [NOAA], 2017).

1.5.5 Current and Future Land Use

The Austin Bergstrom AASF currently includes three aircraft hangars. The facility also houses the

JVMF and the AFRC. Current land use in the direct vicinity of the Austin Bergstrom AASF includes

the ABIA to the north (formerly the Bergstrom AFB) and a park to the south, across Burleson

Road. To the east and west is mostly undeveloped land. The Travis County Landfill is located

approximately 0.5 miles southwest of the facility. No future changes to the current use were noted

during personnel interviews.
CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

MC

4/27/2020

4/27/2020

NOTES Preliminary Assessment for PFAS at Bergstrom AASF, TX

1:63,360

4/27/2020 ­ Figure 1-1 PM RG 4/27/2020

12420 Milestone Center Drive

Germantown, MD 20876

Facility Location

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

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

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\TX\Bergstrom_PA_Figures\Fig_1-1_Bergstrom_Facility_Location.mxd

Legend

Facility Boundary

0 0.5 1 2

Miles

^_

Bergstrom AASF

9
!P

!P

!P

!P

!5

A!

A!

A!

A!

A! A! A!A!

A!

A!

A!

A!

A!

A!

A!

A!

A!

A!

A!

A!

A!

A!

A!

A!

Cottonm outh Cr e ek

Onion Cre e k

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

MC

4/24/2020

4/24/2020

NOTES P re lim inary As s e s s m e nt for P FAS at Aus tin Be rgs trom AASF, TX

1:24,000

4/24/2020 ­ Figure 1-2 P M RG 4/24/2020

12420 Mile s tone Ce nte r Drive

Ge rm antown, MD 20876

Groundwater Features

Bas e Map: Sourc e : Es ri, DigitalGlob e , Ge oEye ,

Earths tar Ge ographic s , CNES/Airb us DS, USDA, USGS,

C:\Us e rs \s tanke vic hm \One Drive - AECOM Dire c tory\ARNG_P FAS_GIS_60552172\MXDs \TX\Be rgs trom _P A_Figure s \Fig_1-2_Be rgs trom _Ground wate r.m xd

Legend

Fac ility Bound ary

Wate r Bod y

Stre am /Rive r

Infe rre d Ground wate r

Flow Dire c tion

Geology

P le is toc e ne ; fluvial

te rrac e d e pos its

Cre tac e ous – Gulfian;

pyroc las tic b as alt

Cre tac e ous – Gulfian;

Ozan Form ation (c lay

or m ud )

Wells

!P Dom e s tic We ll

!5 Ind us trial We ll

A! Monitoring We ll

0 1,000 2,000 4,000

Fe e t

10
Outfall #1

(Discharge to Onion Creek)

Outfall #2

(Capped in 2018)

Carson

Creek-Colorado

River Watershed

Cottonmouth Cre e k

Onion Creek

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

MC

4/24/2020

4/24/2020

NOTES Preliminary Assessment for PFAS at Austin Bergstrom AASF, TX

1:9,600

4/24/2020 ­ Figure 1-3 PM RG 4/24/2020

12420 Milestone Center Drive

Germantown, MD 20876

Surface Water Features

Base Map: Source: Esri, DigitalGlobe, GeoEye,

Earthstar Geographics, CNES/Airbus DS, USDA, USGS,

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\TX\Bergstrom_PA_Figures\Fig_1-3_Bergstrom_Surface_Water.mxd

0 400 800 1,600

Feet

Legend

Facility Boundary

Water Body

Stream/River

Surface Water Flow

Direction

Joint Vehicle 

Maintenance Facility 

Complex Pond

Armed Forces

Reserve Center Pond

Maintenance

Hangar

11
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

12

2. Fire Training Areas

With the exception of mobile cart extinguisher testing/training at the wash rack area (described in

Section 3.3), Austin Bergstrom AASF personnel confirmed there are no designated FTAs at the

facility.
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

13

3. Non-Fire Training Areas

In addition to FTAs, the PA evaluated areas where PFAS-containing materials may have been

broadly used, stored, or disposed. This may include buildings with fire suppression systems, paint

booths, AFFF storage areas, and areas of compliance demonstrations. Information on these

features obtained during the PA are included in Appendices A and B. The Austin Bergstrom

AASF consists of three hangars (Maintenance, Storage, and Fixed Wing Support) that are

equipped with AFFF fire suppression systems. Additional buildings housed at the facility are the

JVMF and AFRC. To the west of the Storage Hangar is a wash rack, which was historically a

location where an AFFF-containing mobile cart fire extinguisher was discharged. A hazardous

materials storage building is located to the east of the Fixed Wing Support Hangar, and the fuel

station is located nearby, to the southeast. These non-FTAs were investigated during the PA. NonFTAs are described below and shown on Figure 3-1, with photographs provided in Appendix C.

3.1 Maintenance Hangar

The Maintenance Hangar, also known as the Rotary Wing Support Hangar, is located in the

central portion of the facility and is used for helicopter maintenance. The hangar and its fire

suppression system were built in 2005. During the site visit, two 800-gallon AFFF tanks and one

100-gallon AFFF tank were observed in the storage room of the Maintenance Hangar. Evidence

of past AFFF spills on the sides of the two 800-gallon tanks were noticeable, but no floor drains

were observed in the room. There have been two releases of AFFF at the Maintenance Hangar.

One was a test release, and the other an accidental release. The test release occurred in

approximately 2005, when the fire suppression system was installed, in order to ensure proper

functioning of the system. After the release occurred, the foam was allowed to settle, then was

pushed down the trench drain, where it travelled to the holding tank, then to the OWS, and then

to the storm water drainage system.

The accidental release occurred on 13 February 2006, as a result of a faulty sensor triggering the

fire suppression system to release. The hangar was filled with foam approximately 5 feet deep.

Foam and water were directed to the holding tank on the south side of the complex. A third party

was contracted to do the following tasks: pressure wash and clean-up the hangar; sample/analyze

spill residue and the contents of the holding tank; pump out the holding tank and store the solution

in frac tanks while waiting on lab results to prevent rain from increasing the volume of solution in

the holding tank; and, dispose of the material. The material released in both incidents was Jet-X

2.75% AFFF. During both releases, an unknown quantity of AFFF was released to the storm water

drainage system. The geographic coordinates for the Maintenance Hangar are 30°10'36.2"N;

97°40'21.0"W.

3.2 Other Hangars

Both the Fixed Wing Support Hangar and the Storage Hangar are equipped with AFFF fire

suppression systems. During the site visit, one 100-gallon tank, two 300-gallon tanks, and four

55-gallon drums of 3% AFFF were observed in the storage room of the Fixed Wing Support

Hangar. In the Storage Hangar, the AFFF fire suppression system consists of one 100-gallon tank

and two 800-gallon tanks. The larger tanks in both hangars had evidence of spillage on the sides

of the tank and ground, but no floor drains were observed in either storage room where bulk AFFF

was stored. Although there were no known releases of AFFF at the Fixed Wing Support Hangar

or the Storage Hangar, it is believed that the AFFF fire suppression systems in the hangars were

likely tested during the commissioning of their installation in 2005. During commissioning, AFFF

foam would have travelled from the hangar to the trench drain, then to the holding tank, OWS,

and finally to the storm water drainage system.
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

14

3.3 Wash Rack Area

The wash rack area is located to the west of the Storage Hangar. From 2005 to 2010, mobile

firefighting carts containing AFFF solution (Tri-MaxTM units) were used on site. Approximately 15

units were in use during this time period. In 2009 or 2010, the Tri-MaxTM units were replaced with

Purple K units, which do not contain AFFF. The Tri-MaxTM units were inspected by the Fire

Marshall during use. When the Tri-MaxTM units were being prepared for disposal, they were

drained into 55-gallon drums, which were then removed from the facility by a contractor.

In 2009, TXARNG personnel recall training with one Tri-MaxTM unit once or twice at the wash

rack. Depending on the position of the diverter valve, liquid that reaches the wash rack either

flows to the holding tank, then to the OWS, then through storm water system piping to the retention

ponds or flows through an oil/sand filter and is discharged to the sanitary sewer. The wastewater

treatment plant (WWTP) for the facility is the South Austin Regional WWTP, located 4.6 miles

northeast of the facility at 13009 Fallwell Ln, Del Valle, Texas 78617.

To the best of their knowledge, TXARNG staff who had been working on site since 2001 reported

no other releases in this area. Geographic coordinates for the wash rack are 30°10'30.9"N;

97°40'27.6"W.

3.4 Hazardous Materials Storage Building

The hazardous materials storage building is located to the east of the Fixed Wing Support Hangar.

Various hazardous materials are stored inside the building. Historically, 105 5-gallon sealed

containers of AFFF were stored inside the building. The 5-gallon buckets were added to helicopter

buckets for firefighting brushfires offsite. Around 2014, the 5-gallon buckets of AFFF were

removed from the facility and sent to the Camp Mabry US Property & Fiscal Office (USPFO) in

Austin, Texas. To the best of their knowledge, TXARNG staff who had been working on site since

2001 reported no releases of any materials in this area. No floor drain was observed in the

hazardous materials storage building. Geographic coordinates for the hazardous materials

storage building are 30°10'42.2"N; 97°40'19.5"W.

3.5 Fuel Station

Historically, AFFF-containing Tri-MaxTM units were stationed at the Fuel Station on site. TXARNG

staff who had been working on site since 2001 reported no releases of any materials in this area.

Precipitation and wastewater in this area flows to the OWS. Geographic coordinates for the fuel

station are 30°10'40.4"N; 97°40'17.8"W.
Storage Hangar

Wash Rack

Maintenance

Hangar

Fuel Station

Hazardous

Materials

Storage Building

Fixed Wing

Support Hangar

Armed Forces

Reserve Center

Joint Vehicle

Maintenance

Facility

Joint Vehicle

Maintenance Facility

Complex Pond

Armed Forces

Reserve

Center Pond

Onion Creek

Holding Tank

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12420 Milestone Center Drive

Germantown, MD 20876

Non-Fire Training Areas

Base Map: Source: Esri, DigitalGlobe, GeoEye,

Earthstar Geographics, CNES/Airbus DS, USDA, USGS,

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Facility Boundary

Water Body

Stream/River

15
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

16

4. Emergency Response Areas

To the best of their knowledge, TXARNG personnel who have been working on site since 2001

reported no past emergency responses. However, the Airport Fire Department conducted an

emergency response southeast of the east runway at the ABIA, when an aircraft crashed in the

fog. The crash occurred in 2002, and AFFF was used at the crash site to put out the aircraft fire.

The National Transportation Safety Board Aviation Accident Data Summary can be found in

Appendix A, and the location of crash can be found on Figure 4-1.
Onion Creek

Location

of 2002

Aircraft Fire

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Germantown, MD 20876

Emergency Response Area

Base Map: Source: Esri, DigitalGlobe, GeoEye,

Earthstar Geographics, CNES/Airbus DS, USDA, USGS,

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0 750 1,500 3,000

Feet

Legend

Potential PFAS Release

Facility Boundary

Water Body

Stream/River

17
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

18

5. Adjacent Sources

Adjacent sources of potential PFAS include the former Bergstrom AFB (now ABIA), the ABIA Fire

Department, and Federal Aviation Administration (FAA) inspections conducted at ABIA. Figure

5-1 shows the adjacent sources described in this section.

5.1 Former Bergstrom AFB

The former Bergstrom AFB is located directly north of the Austin Bergstrom AASF. A site

investigation of potential PFAS release areas conducted at the former AFB revealed that

firefighting training activities at the base were conducted from 1942 to 1991 at FT023P, located

approximately one mile north of the facility. FT023P consisted of one fire training pit,

approximately 200 feet in diameter, with a circular berm and limestone lining (Amec Foster

Wheeler, 2016).

PFAS were tested in surface and subsurface soils at FT023P. The six PFAS constituents tested

were detected above the reporting limits in all three soil locations. Based on these detections,

PFAS constituents were present across the soil column in both shallow (0-2 feet bgs) and in

deeper soil (greater than 2 feet to 35 feet bgs). No results were above the US Air Force Project

Action Limits (Amec Foster Wheeler, 2016).

In groundwater, PFAS were detected above the USEPA Health Advisory levels for PFOA and

PFOS at each of the five locations tested, indicating that PFAS have migrated through FTA soils

into underlying groundwater. FT023P is underlain by terrace deposits consisting of clay from the

surface to approximately 26 feet bgs, then approximately 5.5 feet of silty to clayey gravel. Clay

potentially associated with the Upper Taylor Marl bedrock unit was interpreted as being present

underneath the gravel sediment. However, Cretaceous bedrock in Austin is highly faulted and the

bedrock unit underlying the FTA is uncertain. Local groundwater supply comes primarily from the

regional groundwater aquifer (Edwards Aquifer – Balcones Fault Zone) which occurs at about

1,000 feet bgs at the FTA and is not likely to be affected by the fire training activities. Shallow

groundwater occurs in the fluviatile terrace deposits and is not used at the facility for water supply,

but it has domestic uses 1 mile to the south and southeast of the FTA (Amec Foster Wheeler,

2016).

A second PFAS PA was conducted by Amec Foster Wheeler in December 2015 to determine

whether and where AFFF was stored, handled, used or released at the former Bergstrom AFB, in

areas other than FT023P. The locations determined from that report and described below are

shown on Figure 5-1. The locations identified include the following:

1) Former Building 201 (Fire Station): Facility stored and potentially used AFFF; however, no 

AFFF releases were documented.

2) Former Building 203 (Fire Station Vehicle Washrack): Facility was used to wash

emergency vehicles and included a 400-gallon OWS, with effluent drainage to the sanitary

sewer system.

3) STOR-604 (Base Supply Open Storage Area/Solid Waste Management Unit [SWMU]-

153) and Former Building 604 (Base Hazardous Storage Facility): Open storage area with

building that stored 55-gallon drums and five-gallon containers of AFFF, with a

documented AFFF release inside the building in 1993.

4) Former Discharge Detention Basin (SWMU-223): Unlined basin constructed to contain a

full discharge of AFFF from the fire suppression systems in Hangars 1608 and former

Hangar 1609, with three documented AFFF releases.

5) Hangar 1608 (Regional Corrosion Control Facility) and STOR-1608 (Storage of

Hazardous Waste): Hangar 1608 maintained an AFFF fire suppression system with two
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

19

documented releases. Storage facility STOR-1608 likely stored AFFF; however, no AFFF 

releases were documented at STOR-1608.

6) Former Hangar 1609 (Small Aircraft Maintenance Dock): Hangar maintained an AFFF fire

suppression system with two documented releases.

7) Building 4577 (Crash Fire Station/Vehicle Maintenance Building): Facility may have been

used as a crash fire station; however, no documentation of AFFF storage or use was

found.

5.2 ABIA Fire Station

In 1999, the City of Austin was conveyed a deed notice for 942 acres of the former AFB for the

development of the ABIA. The ABIA Fire Station, approximately 1.4 miles north-northeast of the

facility (Austin Fire Department, 2019), stores AFFF and houses four fire trucks that all use AFFF.

AFFF is tested at the Austin Fire Department training facility at 4800 Shaw Ln, approximately 2

miles west-northwest of the facility. Additionally, Federal Aviation Administration (FAA) inspections

include the use of AFFF at unspecified locations around the airport. The last inspection occurred

in 2019 and included the use of AFFF, although efforts were made to mitigate the foam.

5.3 Landfill

The Travis County Landfill is located approximately 0.6 miles southwest of the facility. Hazardous

wastes in this landfill likely includes pesticides, paints, and paint thinners, solvents, and oils

(EDRTM, 2019). Landfills are not usually a primary release area of PFAS, but materials disposed

in landfills may create a secondary source of contamination. Such materials may include sludge

from a WWTP that processes PFAS-laden water, used AFFF storage containers, or products

associated with waterproofing uniforms or boots.
Approximate Austin

Bergstrom International

Airport Boundary

Former Bergstrom

AFB Fire

Training Pit

Former AFB

Building 201

(Fire Station)

Former AFB

Building 203 (Fire

Station Wash Rack)

Former AFB STO-604

and Former AFB

Building 604

Former AFB Discharge

Detention Basin

Former AFB

Hangar 1608

and STOR-1608

Former AFB

Hangar 1609

Building 4577

Austin Fire

Department

Travis

County

Landfill

Cottonm outh Cr eek

Onion Creek

CarsonCreek

Colorado River

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12420 Milestone Center Drive

Germantown, MD 20876

Adjacent Source

Base Map: Source: Esri, DigitalGlobe, GeoEye,

Earthstar Geographics, CNES/Airbus DS, USDA, USGS,

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\TX\Bergstrom_PA_Figures\Fig_5-1_Bergstrom_AASF_Adjacent_Sources.mxd

0 1,300 2,600 5,200

Feet

Legend

Potential PFAS Release

Facility Boundary

Water Body

Stream/River

20
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

21

6. Preliminary Conceptual Site Model

Based on the PA findings, the AFFF release areas associated with the Austin Bergstrom AASF

Maintenance Hangar and the wash rack were identified as AOI 1 and AOI 2, respectively. The

AFFF fire suppression systems at the Fixed Wing Support Hangar and the Storage Hangar are

identified as AOI 3 and the Hazardous Materials Storage Building and Fuel Station are identified

as AOI 4. This section describes the CSM components developed for these four AOIs. The CSM

identifies the three components necessary for a potentially complete exposure pathway: (1)

source, (2) pathway, and (3) receptor. If any of these elements are missing, the pathway is

considered incomplete. The AOIs are shown on Figure 6-1, and the preliminary CSM is presented

on Figure 6-2.

6.1 Pathways

In general, the potential PFAS exposure pathways are ingestion and inhalation. Human exposure

via the dermal contact pathway may occur, and current risk practice suggests it is an insignificant

pathway compared to ingestion; however, exposure data for dermal pathways is sparse and

continues to be the subject of PFAS toxicological study.

PFAS contamination may have infiltrated to surface and subsurface soil in the vicinity of the wash

rack and hangars. Under such a scenario, ground disturbing activities in these areas could result

in site and construction worker exposure to PFAS via inhalation of dust or ingestion of exposed

surface soil, and construction workers exposure to PFAS via inhalation of dust or ingestion of

exposed subsurface soil. There is also potential for exposure to PFAS contamination in surface

water/sediment in the retention ponds.

Potential PFAS contamination may have further infiltrated to shallow groundwater from infiltration

at the retention ponds on-site. Four domestic wells are located between 0.3 and 0.6 miles

northeast and southeast of the facility and range from 35 to 70 feet deep. Therefore, the ingestion

exposure pathway for off-facility residents using groundwater is potentially complete.

6.2 Receptors

Receptors at Austin Bergstrom AASF include site workers, construction workers, and residents

outside the facility boundary. These receptors, as they pertain to the facility are described below:

• Site workers typically work at or use the site and may come into contact with the surface soils.

Site workers may also come into contact with surface water in the retention ponds at the facility.

• Construction workers are considered workers who represent a utility worker or other worker

who would be exposed to surface and/or subsurface conditions through ground-disturbing

activities.

• Off-facility recreational users typically identify a person who may recreationally use an offfacility area that may be affected by a PFAS release from the facility. Off-facility recreational users

could be exposed to sediment and surface water during recreational use.

• Off-facility residents identify receptors who occupy properties outside of the facility. Off-facility

residents may come into contact with groundwater using private, domestic, agricultural and/or

public supply wells.

The preliminary CSM for the facility indicates which specific receptors could potentially be

exposed to PFAS. The preliminary CSM for AOIs 1, 2, 3 and 4 is shown on Figure 6-2.
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

22

6.3 AOI 1 Maintenance Hangar

AFFF was released into the Maintenance Hangar during routine testing of the newly installed fire

protection system in 2005, and during an accidental release in 2006. While there is a record of

the handling of the AFFF produced during the accidental release, there is no record of the handling

and disposal of the AFFF produced from the first release in 2005. It is assumed that some quantity

of AFFF was released into the storm water drainage system during both releases.

Releases at the Maintenance Hangar would have been conveyed to the trench drains, then to the

holding tank, and then to the OWS. The first test release was then conveyed to the storm water

drainage system. During the second (accidental) release, AFFF solution was captured at the

holding tank and then stored in frac tanks for analysis and disposal. However, an unknown

quantity of AFFF solution most likely was released to the storm water drainage system before

corrective measures were taken during the release.

6.4 AOI 2 Wash Rack

AFFF was used in Tri-MaxTM units from 2005 to 2010. Fire training was conducted once or twice

in 2009 at the wash rack (AOI 2). An unknown quantity of AFFF was released during these fire

training events. Liquid that reaches the wash rack either travels to the holding tank, OWS, and

storm water drainage system, or is diverted to the oil/sand filter and sanitary sewer system,

depending on the positioning of a diverter valve. The position of the diverter valve at the time of

AFFF training is unknown.

Based on the nature of the release (during testing/training), it appears unlikely AFFF would have

been discharged to the ground surface outside of the wash rack, but AFFF foam may have

migrated to the surrounding grassy area and infiltrated into the soil.

6.5 AOI 3 Fixed Wing Support Hangar and Storage Hangar

The Fixed Wing Support Hangar and the Storage Hangar are both equipped with AFFF fire

suppression systems. It is likely that both systems were tested in 2005 when the hangars were

being commissioned, leading to a release of AFFF. The flow pathway from the smaller hangers

would have consisted of AFFF flowing from the hangar to the trench drain, then to the holding

tank, OWS, and finally to the storm water drainage system.

6.6 AOI 4 Hazardous Materials Storage Building and Fuel Station

The Hazardous Materials Storage Building historically contained 105 5-gallon sealed containers

of AFFF and the Fuel Station historically had AFFF-containing Tri-MaxTM units stationed around

the area. Although TXARNG reported no known releases of any PFAS-containing materials in

either area, these areas should be investigated for potential release. Surface water in the

vicinity of the Hazardous Materials Storage Building could potentially allow AFFF to infiltrate into

nearby grassy areas, and surface water in the vicinity of the Fuel Station flows to the OWS.
!P

!P

!P

!P

!5

A!

A!

A!

A!

A! A! A!A!

A! A! A!

A!

A!

A!

A!

A!

A!

A!

A!

A!

A!

A!

A!

A!

Storage Hangar

Wash Rack

Maintenance Hangar

Fuel Station

Hazardous Materials

Storage Building Fixed Wing

Support Hangar

Former Bergstrom AFB 

Fire Training Pit

Location

of 2002

Aircraft Fire

Former AFB

Building 201

(Fire Station)

Former AFB

Building 203 (Fire

Station Wash Rack)

Former AFB STO-604

and Former AFB

Building 604

Former AFB Discharge

Detention Basin

Former AFB

Hangar 1608

and STOR-1608

Former AFB

Hangar 1609

Building 4577

Austin Fire

Department

Travis

County

Landfill

Armed Forces 

Reserve Center

Joint Vehicle

Maintenance Facility

Joint Vehicle Maintenance 

Facility Complex Pond

Armed Forces

Reserve Center Pond

Holding Tank

AOI 3

AOI 2

AOI 1

AOI 3

AOI 4

Approximate Austin

Bergstrom International

Airport Boundary

Carson

Creek-Colorado

River Watershed

Cotton m outh Cr eek

Carso nCreek

Onion Creek

Colorado River

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12420 Milestone Center Drive

Germantown, MD 20876

Areas of Interest

Base Map: Source: Esri, DigitalGlobe, GeoEye,

Earthstar Geographics, CNES/Airbus DS, USDA, USGS,

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0 1,200 2,400 4,800

Feet

Legend

Area of Interest

Potential PFAS Release

No Suspected Release

Facility Boundary

Water Body

Stream/River

Surface Water Flow

Direction

Inferred Groundwater

Flow Direction

!P Domestic Well

!5 Industrial Well

A! Monitoring Well

23
Media

SOURCE PATHWAY RECEPTOR

AOI 1

AOI 2

AOI 3

AOI 4

AFFF Release

during testing and

accidental triggering

of the AFFF fire

suppression

systems, and during

AFFF fire

extinguisher testing/

training. Potential

release from AFFF

storage areas.

PFAS in

Surface Soil

PFAS in

Subsurface

Soil via

infiltration at

Retention

Ponds

Human

Activities

Leaching/

Infiltration

Airborne Soil

particulate

Surface Soil

at AOI

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

Complete Pathway

Site

Worker

Construction

Worker Resident Trespasser/Recreational User

Site

Worker

Construction

Worker Resident Trespasser/

Recreational User

/ / /

/ /

LEGEND

/ /

/ / /

Figure 6-2

Preliminary Conceptual Site Model

Austin Bergstrom AASF

Potential

Off-Facility

Source Not

under

Control of

ARNG

/

/

/

/

/

/ /

/

/

Note:

1. The residential receptor

refers to an off-facility

receptor.

/

Precipitation/

Run-Off

24
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

25

7. Conclusions

Four AOIs were identified at Austin Bergstrom AASF during the PA (Figure 7-1).

7.1 Findings

Based on interviews with current facility personnel, reported historical AFFF releases are

associated with the Maintenance Hangar AFFF releases, AFFF fire extinguisher testing/training

at the wash rack, AFFF fire suppression systems at the Storage Hangar and Fixed Wing Support

Hangar, and the storage of AFFF in the hazardous materials storage building and Tri-MaxTM units

at the Fuel Station. These releases indicate the potential for PFAS contamination in media at or

near the facility. The preliminary CSM for the Austin Bergstrom AASF is shown on Figure 6-2,

which presents the potential receptors and media impacted. No evidence of other accidental or

incidental spills or leaks from AFFF storage containers/areas were identified during the site visit.

The remaining buildings associated with the facility are not equipped with AFFF. The findings of

potential AFFF release are summarized in Table 7-1 below.

Table 7-1: AOIs at Austin Bergstrom AASF

Area of Interest Name Used by Release Dates

AOI 1 Two AFFF fire suppression system

releases occurred at the

Maintenance Hangar. Releases

discharged to trench drains in the

hangar, which flowed to the below

ground holding tank, then to the

OWS and then either to the storm

water drainage system (test

release) or to frac tanks for holding

(accidental release).

TXARNG 2005-2006

AOI 2 Releases occurred during AFFF fire

extinguisher testing/training with

mobile carts at the wash rack. Flow

either travelled from the wash rack

to the holding tank, OWS, then to

the storm water drainage system or

from the wash rack to an oil/sand

filter, and then to the sanitary sewer,

depending on the positioning of the

diverter valve.

TXARNG 2009

AOI 3 The Fixed Wing Support Hangar

and the Storage Hangar are both

equipped with AFFF fire

suppression systems. It is likely that

both systems were tested in 2005,

when the hangars were being

commissioned, leading to a release

of AFFF. The flow path for AFFF

would have been from the hangars

to the trench drain, the holding tank,

OWS, and finally to the storm water

drainage system.

TXARNG 2005
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

26

AOI 4 The Hazardous Materials Storage

Building and the Fuel Station both

historically contained AFFF in 5-

gallon containers and in Tri-MaxTM

units (respectively). These areas will

be investigated for potential PFAS

release.

TXARNG 2005-2014

7.2 Uncertainties

Available information sources were investigated during this PA to determine the potential for

PFAS-containing materials to have been present, used, or released at the facility. Historically,

documentation of PFAS use was not required because PFAS were considered benign. Therefore,

records were not typically kept by the facility or available during the PA on the use of PFAS in

training, firefighting, or other non-traditional activities, or on its disposal.

The conclusions of this PA are based on all available information, including: previous

environmental reports, EDRsTM, observations made during the VSI, and interviews. Interviews of

personnel with direct knowledge of a facility generally provided the most useful insights regarding

a facility's historical and current PFAS-containing materials. Sometimes the provided information

was incomplete. Gathered information has a degree of uncertainty due to the absence of written

documentation, the limited number of personnel with direct knowledge due to staffing changes,

the time passed since PFAS were first used (1969 to present), and a reliance on personal

recollection. Inaccuracies may arise in potential PFAS release locations, dates of release, volume

of releases, and the concentration of AFFF used. There is also a possibility the PA has missed a

source of PFAS, as the science of how PFAS may enter the environment continually evolves.

In order to minimize the level of uncertainty, readily available data regarding the use and storage

of PFAS were reviewed, current personnel were interviewed, multiple persons were interviewed

for the same potential source area, and potential source areas were visually inspected.

Table 7-2 summarizes the uncertainties associated with the PA:

Table 7-2: Uncertainties

Area of Interest Source of Uncertainty

AOI 1 Maintenance Hangar The quantity of AFFF released at the Maintenance

Hangar during the two releases is unknown, as well as

how much AFFF was discharged to the storm water

drainage system before the frac tanks were put in place

during the second release.

AOI 2 Wash Rack The quantity of AFFF used for fire training purposes is

unknown, as well as the flow pathway of water entering

the wash rack. Interviewees stated that a diverter valve

exists that diverts water from the storm water drainage

system to the sanitary sewer system. It is unknown at

what setpoint the diverter is actuated.

AOI 3 Fixed Wing Support Hangar

and Storage Hangar

It is unknown how the AFFF fire suppression systems

in the Storage Hangar and the Fixed Wing Support

Hangar were tested, and what quantity of AFFF was

produced.
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

27

Emergency Response Area An unknown quantity of AFFF was released during the

emergency response at the aircraft crash site located to

the southeast of the east runway at ABIA. The fire was

extinguished by the Airport Fire Department.

7.3 Potential Future Actions

Based on the documented presence (2005-2009) of the release of PFAS-containing materials at

the facility, evidence indicates that former TXARNG activities contributed PFAS contamination to

soil and potentially groundwater at Austin Bergstrom AASF. The facility will move forward in the

CERCLA process.

Interviews (covering 2001 to present) indicate that releases related to AFFF fire suppression

systems in the hangars (AOIs 1 and 3) and fire extinguisher testing/training in the wash rack area

(AOI 2) may have resulted in PFAS releases identified during the PA. Additionally, storage of AFFF

in 5-gallon containers at the hazardous materials storage building and AFFF-containing Tri-MaxTM

units at the Fuel Station (AOI 4) may have led to a release as well. Based on the preliminary CSM

developed for the AOIs, there is potential for receptors to be exposed to PFAS contamination in

soil, surface water/sediment and groundwater at the AOIs. Table 7-3 summarizes the rationale

used to determine if the AOIs should be considered for further investigation under the CERCLA

process and undergo an SI.

ARNG will evaluate the need for an SI at AOIs 1, 2, 3 and 4 at Austin Bergstrom AASF based on

the presence of a PFAS release, possible receptors, the migration potential of PFAS

contamination to receptors, and the availability of resources.

Table 7-3: Rationale

Area of

Interest

AOI

Location Rationale Potential FutureAction

AOI 1:

Maintenance

Hangar

30°10'36.2"N;

97°40'21.0"W

Releases during AFFF fire suppression

system test and accidental discharge; 

water flowed to holding tank, OWS,

then to the storm water drainage

system.

Proceed to an SI,

focus on soil,

surface water/

sediment and

groundwater

AOI 2: Wash

rack

30°10'30.9"N;

97°40'27.6"W

Releases during AFFF fire extinguisher

testing/training with mobile carts at the

wash rack. Flow either discharges to

the holding tank, OWS, then to the

storm water drainage, or is diverted to

the sanitary sewer system.

Proceed to an SI,

focus on soil,

surface

water/sediment

and groundwater

AOI 3: Fixed

Wing

Support

Hangar and

Storage

Hangar

30°10'41.9"N;

97°40'21.1"W

and

30°10'30.5"N;

97°40'23.4"W

The two smaller hangars are both

equipped with AFFF fire suppression

systems. It is likely that both systems

were tested in 2005, when the hangars

were being commissioned, leading to a

release of AFFF. The flow path for

AFFF foam would have been from the

hangar to the trench drain, holding

tank, OWS, and finally to the storm

water drainage system.

Proceed to an SI,

focus on soil,

surface water/

sediment and

groundwater
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

28

AOI 4:

Hazardous

Materials

Storage

Building and

Fuel Station

30°10'42.2"N; 

97°40'19.5"W

and

30°10'40.4"N; 

97°40'17.8"W

AFFF was stored at the Hazardous

Materials Storage Building and at the

Fuel Station. Although there are no

documented releases at either location,

they should be investigated to

determine if PFAS releases occurred.

Proceed to an SI,

focus on soil and

groundwater.
Storage Hangar

Wash Rack

Maintenance Hangar

Fuel Station

Hazardous Materials

Storage Building Fixed Wing

Support Hangar

Former Bergstrom AFB 

Fire Training Pit

Location

of 2002

Aircraft Fire

Former AFB

Building 201

(Fire Station)

Former AFB

Building 203 (Fire

Station Wash Rack)

Former AFB STO-604

and Former AFB

Building 604

Former AFB Discharge

Detention Basin

Former AFB

Hangar 1608

and STOR-1608

Former AFB

Hangar 1609

Building 4577

Austin Fire

Department

Travis

County

Landfill

Armed Forces 

Reserve Center

Joint Vehicle

Maintenance Facility

Joint Vehicle 

Maintenance Facility Complex Pond

Armed Forces

Reserve Center Pond

Holding Tank

AOI 3

AOI 2

AOI 1

AOI 3

AOI 4

Approximate Austin

Bergstrom International

Airport Boundary

Cotton m outh Cr eek

Carso nCreek

Onion Creek

Colorado River

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

MC

4/27/2020

4/27/2020

NOTES Preliminary Assessment for PFAS at Bergstrom AASF, TX

1:28,800

4/27/2020 ­ Figure 7-1 PM RG 4/27/2020

12420 Milestone Center Drive

Germantown, MD 20876

Summary of Findings

Base Map: Source: Esri, DigitalGlobe, GeoEye,

Earthstar Geographics, CNES/Airbus DS, USDA, USGS,

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\TX\Bergstrom_PA_Figures\Fig_7-1_Bergstrom_AASF_Summary.mxd

0 1,200 2,400 4,800

Feet

Legend

Area of Interest

Potential PFAS Release

No Suspected Release

Facility Boundary

Water Body

Stream/River

29
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

30

8. References

Amec Foster Wheeler. June 2016. Final Site Investigation Report, Former Bergstrom AFB, TX.

Site Investigation of Potential Perfluorinated Compound (PFC) Release Areas at Multiple United

States Air Force Base Realignment and Closure Installations. AR #558322. Prepared for Air

Force Civil Engineer Center.

Austin-Bergstrom International Airport. February 2019. Site Topography and Storm Water

Drainage System, Figure 4-2.

Austin Fire Department locations. 2019. http://www.austintexas.gov/page/index-afd-stationsaddresses. Accessed 23 September 2019.

Bureau of Economic Geology. 1976. Environmental Geology of the Austin Area. University of

Texas at Austin.

EDRTM. December 2019. The EDR Radius MapTM Report with GeoCheck. Austin-Bergstrom

AASF. Inquiry Number: 5900192.2s.

Jose I. Guerra, Inc. 2010. 24” and 30” reinforced concrete pipe (RCP) Discharge Outlet Plans.

Engineering Drawings.

Law Environmental, Inc. October 1995. Installation Restoration Program (IRP) RCRA Facility

Assessment/RCRA Facility Investigation, Ground-water Gradient Determination, Bergstrom Air

Force Base, Austin, Texas.

National Oceanic and Atmospheric Administration (NOAA). 2017. Austin Climate Summary.

https://www.weather.gov/media/ewx/climate/ClimateSummary-ewx-Austin.pdf. Accessed 27

June 2019.

National Weather Service Forecast Office. 2019. Austin/San Antonio, TX.

https://w2.weather.gov/climate/index.php?wfo=ewx. Accessed 17 October 2019.

Texas Water Development Board. July 2011. Aquifers of Texas.

http://www.twdb.texas.gov/publications/reports/numbered_reports/doc/R380_AquifersofTexas.p

df?d=931170.1400000001. Accessed 21 October 2019.

United States Environmental Protection Agency (USEPA). September 1991. Guidance for

Performing Preliminary Assessments under CERCLA. EPA/540/G-91/013.

United States Geological Survey. November 2016. Ground Water Atlas of the United States.

Oklahoma, Texas. Trinity Aquifer. https://pubs.usgs.gov/ha/ha730/ch_e/E-text8.html. Accessed

21 October 2019.

Young, K. 1977. Guidebook to the Geology of Travis County. Walter Geology Library.
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

Appendix A

Data Resources
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

Data resources will be provided separately on CD. Data resources for Austin Bergstrom AASF

include:

Previous Investigations Completed

· Amec Foster Wheeler. December 2015. Final Perfluorinated Compounds Preliminary

Assessment, Former Bergstrom AFB, Texas. AR #469412. Prepared for Air Force Civil

Engineer Center.

· Amec Foster Wheeler. June 2016. Final Site Investigation Report, Former Bergstrom AFB,

TX. Site Investigation of Potential Perfluorinated Compound (PFC) Release Areas at

Multiple United States Air Force Base Realignment and Closure Installations. AR #558322.

Prepared for Air Force Civil Engineer Center.

· Law Environmental, Inc. October 1995. Installation Restoration Program (IRP) RCRA

Facility Assessment/RCRA Facility Investigation, Ground-water Gradient Determination,

Bergstrom Air Force Base, Austin, Texas.

Miscellaneous Data Resources

· 2006 AFFF Release Report and Photographs

· Austin-Bergstrom International Airport. February 2019. Site Topography and Storm Water

Drainage System, Figure 4-2.

· Landrum & Brown. December 2018. Austin-Bergstrom International Airport (ABIA) Master

Plan. Draft Chapter 2: Existing Conditions.

· Bergstrom Lease Agreement. 2002.

· Bureau of Economic Geology. 1976. Environmental Geology of the Austin Area. University

of Texas at Austin.

· EDRTM. December 2019. The EDRTM Aerial Photo DecadeTM Package. Austin-Bergstrom

AASF. Inquiry Number: 5900192.6.

· EDRTM. December 2019. The EDRTM Radius MapTM Report with GeoCheck. AustinBergstrom AASF. Inquiry Number: 5900192.2s.

· EDRTM. December 2019. Certified Sanborn® Map Report. Austin-Bergstrom AASF. Inquiry

Number: 5900192.3.

· Jose I. Guerra, Inc. 2010. 24” and 30” reinforced concrete pipe (RCP) Discharge Outlet

Plans. Engineering Drawings.

· National Transportation Safety Board Aviation Accident Data Summary. March 2002.
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

Appendix B

Preliminary Assessment Documentation
PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

Appendix B.1

Interview Records






PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

Appendix B.2

Visual Site Inspection Checklists

PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

Appendix B.3

Conceptual Site Model Information



PFAS Preliminary Assessment Report

Austin Bergstrom AASF

Austin, TX

Appendix C

Photographic Log
Preliminary Assessment Report

Austin Bergstrom AASF Austin, TX

Perfluorooctane-Sulfonic Acid (PFOS) and 

Perfluorooctanoic Acid (PFOA) Impacted Sites

ARNG Installations, Nationwide

AECOM

APPENDIX C – Photographic Log

Army National Guard, Preliminary

Assessment for PFAS Austin Bergstrom AASF (April 24, 2019) Austin, Texas

Photograph No. 1

Description:

1 of 2 - 800 gallon tanks 

located in the Maintenance 

Hangar. Tank contains 800 

gallons of Rockwood Jet-X® 

High expansion foam 

concentrate. 

Photograph No. 2

Description: 

100 gallon tank of AFFF foam 

concentrate in Maintenance 

Hangar. Used to supply Hand 

Held Hoses with AFFF. 
Preliminary Assessment Report

Austin Bergstrom AASF Austin, TX

Perfluorooctane-Sulfonic Acid (PFOS) and 

Perfluorooctanoic Acid (PFOA) Impacted Sites

ARNG Installations, Nationwide

AECOM

APPENDIX C – Photographic Log

Army National Guard, Preliminary

Assessment for PFAS Austin Bergstrom AASF (April 24, 2019) Austin, Texas

Photograph No. 3

Description:

Ansulite AFFF 3% 

concentrate stored in 100 

gallon tank in Maintenance 

Hangar for use in Hand Held 

Hoses for emergency fire 

suppression. 

Photograph No. 4

Description: 

Photograph of 2 x 800 gallon 

tanks of Jet-X® High 

expansion foam concentrate 

for use in the Maintenance 

Hangar fire suppression 

system. 
Preliminary Assessment Report

Austin Bergstrom AASF Austin, TX

Perfluorooctane-Sulfonic Acid (PFOS) and 

Perfluorooctanoic Acid (PFOA) Impacted Sites

ARNG Installations, Nationwide

AECOM

APPENDIX C – Photographic Log

Army National Guard, Preliminary

Assessment for PFAS Austin Bergstrom AASF (April 24, 2019) Austin, Texas

Photograph No. 5

Description:

Photograph of 2 x 800 gallon 

Jet-X High expansion foam 

tanks and 1 x 100 gallon 

AFFF foam tank in 

Maintenance Hangar for 

emergency fire suppression. 

System is currently offline, 

waiting for system repairs. 

Photograph No. 6

Description: 

Fire suppression nozzles in 

Storage Hangar. 
Preliminary Assessment Report

Austin Bergstrom AASF Austin, TX

Perfluorooctane-Sulfonic Acid (PFOS) and 

Perfluorooctanoic Acid (PFOA) Impacted Sites

ARNG Installations, Nationwide

AECOM

APPENDIX C – Photographic Log

Army National Guard, Preliminary

Assessment for PFAS Austin Bergstrom AASF (April 24, 2019) Austin, Texas

Photograph No. 7

Description:

Facing west, looking at wash 

rack. Fire training activities 

took place in this area in 2009. 

One Tri-Max unit was used 

for training in 2009. Training 

occurred once or twice during 

2009. 

Photograph No. 8

Description: 

Diverter valve near wash rack 

that diverts flow from storm 

sewer to sanitary sewer when 

pressure set point is reached. 
Preliminary Assessment Report

Austin Bergstrom AASF Austin, TX

Perfluorooctane-Sulfonic Acid (PFOS) and 

Perfluorooctanoic Acid (PFOA) Impacted Sites

ARNG Installations, Nationwide

AECOM

APPENDIX C – Photographic Log

Army National Guard, Preliminary

Assessment for PFAS Austin Bergstrom AASF (April 24, 2019) Austin, Texas

Photograph No. 9

Description:

7 empty Tri-Max units 

stationed near wash rack, 

waiting for disposal offsite. 

Photograph No. 10

Description: 

Oil/sand filter near wash rack 

on southwest corner of site. 
Preliminary Assessment Report

Austin Bergstrom AASF Austin, TX

Perfluorooctane-Sulfonic Acid (PFOS) and 

Perfluorooctanoic Acid (PFOA) Impacted Sites

ARNG Installations, Nationwide

AECOM

APPENDIX C – Photographic Log

Army National Guard, Preliminary

Assessment for PFAS Austin Bergstrom AASF (April 24, 2019) Austin, Texas

Photograph No. 11

Description:

50,000 gallon holding tank 

located along south side of 

site. 

Photograph No. 12

Description: 

Jet-X® High expansion foam 

nozzles used in Maintenance 

Hangar and Fixed Wing 

Hanger.
Preliminary Assessment Report

Austin Bergstrom AASF Austin, TX

Perfluorooctane-Sulfonic Acid (PFOS) and 

Perfluorooctanoic Acid (PFOA) Impacted Sites

ARNG Installations, Nationwide

AECOM

APPENDIX C – Photographic Log

Army National Guard, Preliminary

Assessment for PFAS Austin Bergstrom AASF (April 24, 2019) Austin, Texas

Photograph No. 13

Description:

Fixed Wing Hangar with 1 x 

100 gallon tank of AFFF 3% 

concentrate, and 2 x 300 

gallon tanks of Jet-X ® High 

expansion foam concentrate. 

All fire suppression systems 

are currently offline, waiting 

for maintenance. 

Photograph No. 14

Description: 

4 x 55 gallon totes of 3% 

AFFF foam concentrate stored 

in Fixed Wing Hangar. 
Preliminary Assessment Report

Austin Bergstrom AASF Austin, TX

Perfluorooctane-Sulfonic Acid (PFOS) and 

Perfluorooctanoic Acid (PFOA) Impacted Sites

ARNG Installations, Nationwide

AECOM

APPENDIX C – Photographic Log

Army National Guard, Preliminary

Assessment for PFAS Austin Bergstrom AASF (April 24, 2019) Austin, Texas

Photograph No. 15

Description:

Hazardous Materials storage 

area. In 2014, 105 – 5 gallon 

buckets of AFFF were 

disposed of to a contractor. 

Buckets were previously 

stored in this container. 

Hazardous materials storage 

container is located directly 

east of the Fixed Wing 

Support Hangar. 

Photograph No. 16

Description: 

Fuel storage area. Historically 

had Tri-Max fire extinguisher 

at this location, although it 

was never deployed. 
Preliminary Assessment Report

Austin Bergstrom AASF Austin, TX

Perfluorooctane-Sulfonic Acid (PFOS) and 

Perfluorooctanoic Acid (PFOA) Impacted Sites

ARNG Installations, Nationwide

AECOM

APPENDIX C – Photographic Log

Army National Guard, Preliminary

Assessment for PFAS Austin Bergstrom AASF (April 24, 2019) Austin, Texas

Photograph No. 17

Description:

Facing northeast, looking out 

at the Joint Vehicle 

Maintenance Facility Complex 

Pond. Storm water collects in 

this pond before it is used for 

the irrigation well or 

discharges to Onion Creek.