FINAL

Site Inspection Report 

Biak Training Center Brett Hall

Powell Butte, Oregon

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 

August 2023

Prepared for:

Army National Guard Bureau

111 S. George Mason Drive

Arlington, VA 22204

UNCLASSIFIED
THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM i

Table of Contents

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

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

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

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

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

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

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

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

2.2.2 Hydrogeology..............................................................................................2-3

2.2.3 Hydrology....................................................................................................2-4

2.2.4 Climate........................................................................................................2-5

2.2.5 Current and Future Land Use......................................................................2-5

2.2.6 Sensitive Habitat and Threatened/ Endangered Species.............................2-5

2.3 History of PFAS Use..............................................................................................2-5

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

3.1 AOI 1 Engine Academy Training Area ...................................................................3-1

3.2 AOI 2 Bomb Squad Training Area..........................................................................3-1

3.3 AOI 3 Range Control Infiltration Basin...................................................................3-1

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....................................................................................4-1

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 Permanent Well Installation and Groundwater 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

6.3.3 AOI 1 Conclusions ......................................................................................6-2

6.4 AOI 2.....................................................................................................................6-3
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM ii

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

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

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

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

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

6.5.2 AOI 3 Conclusions ......................................................................................6-4

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

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

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

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

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

7.3 Surface Water and Sediment Exposure Pathway ..................................................7-2

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

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

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

9. References...................................................................................................................9-1
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM iii

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

B4. Survey Data

Appendix C Photographic Log

Appendix D TPP Meeting Minutes

Appendix E Boring Logs and Well Construction Forms 

Appendix F Analytical Results

Appendix G Laboratory Reports

Figures

Figure 2-1 Facility Location

Figure 2-2 Facility Topography

Figure 2-3 Groundwater Features

Figure 2-4 Groundwater Elevations, June 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, AOI 2, and 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

Table 5-3 Permanent Monitoring 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
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM iv

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM v

Acronyms and Abbreviations

% percent

°C degrees Celsius

°F degrees Fahrenheit

μg/kg micrograms per kilogram

AECOM AECOM Technical Services, Inc.

AFFF aqueous film-forming foam

amsl above mean sea level

AOI Area of Interest

ARNG Army National Guard

ASTM American Society for Testing and Materials

bgs below ground surface 

BLM Bureau of Land Management

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act 

CoC chain of custody

COUTES Central Oregon Unit Training Equipment Site

CSM conceptual site model

DA Department of the Army

DEQ Department of Environmental Quality

DoD Department of Defense

DOGAMI Department of Geology and Mineral Industries

DOT Department of Transportation

DQO data quality objective

DUA data usability assessment

EDRTM Environmental Data Resources, Inc.TM

ELAP Environmental Laboratory Accreditation Program

EM Engineer Manual

FBI Federal Bureau of Investigation

FedEx Federal Express

FRB field reagent blank

FTA Fire Training Area

GPRS Ground Penetrating Radar Systems

HDPE high-density polyethylene 

HFPO-DA hexafluoropropylene oxide dimer acid

HUC hydrologic unit code

IDW investigation-derived waste

ITRC Interstate Technology Regulatory Council

LC/MS/MS liquid chromatography with tandem mass spectrometry

LOD limit of detection

MIL-SPEC military specification

MOUT Military Operations on Urban Terrain

MS/MSD matrix spike/ matrix spike duplicate

NELAP National Environmental Laboratory Accreditation Program

ng/L nanograms per liter
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM vi

NOAA National Oceanic and Atmospheric Administration

NTU Nephelometric Turbidity Unit

OHA Oregon Health Authority

OMD Oregon Military Department

ORARNG Oregon Army National Guard

OSD Office of the Secretary of Defense

OWRD Oregon Water Resources Department

PA Preliminary Assessment

PFAS per- and polyfluoroalkyl substances

PFBS perfluorobutanesulfonic acid

PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

PFOA perfluorooctanoic acid

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

USDA United States Department of Agriculture

USDI United States Department of Interior

USEPA United States Environmental Protection Agency

USFS United States Forest Service

USFWS United States Fish and Wildlife Service

USGS United States Geological Survey
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM ES-1

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 two Areas of Interest (AOIs) where PFAS-containing materials may have been 

used, stored, disposed, or released historically (see Table ES-2 for AOI locations). During the SI, 

an additional AOI (AOI 3) was identified. 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

Biak Training Center Brett Hall, Powell Butte, Oregon and determined no further evaluation under 

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

warranted for each of the three AOIs at this time. Biak Training Center Brett Hall will also be 

referred to as the “facility” throughout this document.

Biak Training Center Brett Hall is located in Powell Butte, Oregon, approximately 4 miles 

southeast of the City of Redmond and approximately 14 miles northeast of the City of Bend. The 

facility is occupied and operated by the Oregon ARNG as a military training center. Training at the 

facility includes military personnel and civilian personnel, such as law enforcement, fire 

departments, state agencies and non-DoD federal agencies.

The PA identified two AOIs for investigation during the SI phase. A third AOI was identified after 

the PA. 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, no further evaluation 

under CERCLA is warranted for each of the three AOIs at this time.

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.
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

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.) Screening values for HFPO-DA were established after SI planning and execution and thus not included as an analyte. 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 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

Engine 

Academy 

Training Area

No further 

action

2 Bomb Squad 

Training Area N/A No further action

3 

Range

Control 

Infiltration 

Basin

N/A N/A No further 

action

Legend:

N/A = not applicable 

= detected; exceedance of the screening levels

= detected; no exceedance of the screening levels

= not detected
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

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 Biak Training Center 

Brett Hall, Powell Butte, Oregon. Biak Training Center Brett Hall is also referred to as the “facility”

throughout this document.

The SI project elements were performed in compliance with Comprehensive Environmental 

Response, Compensation, and Liability Act (CERCLA; 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 Biak Training Center Brett Hall (AECOM Technical Services, Inc. 

[AECOM], 2019) that identified two Areas of Interest (AOIs) where PFAS-containing materials 

may have been used, stored, disposed, or released historically. A third AOI was added during the 

SI. 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.
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 1-2

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 2-1

2. Facility Background

2.1 Facility Location and Description

Biak Training Center Brett Hall is located in Powell Butte, Crook County, approximately 4 miles to 

the southeast of the City of Redmond and approximately 14 miles to the northeast of the City of 

Bend. Biak Training Center Brett Hall is located approximately 2.5 miles to the south of Highway 

126 (Figure 2-1). Biak Training Center Brett Hall is occupied and operated by the Oregon ARNG 

(ORARNG) as a military training center, and it encompasses 4,300 acres of which 100 acres are 

designated as Biak Training Center Brett Hall (Oregon Military Department [OMD], 2018a). 

Biak Training Center Brett Hall includes one building used as the training center, two warehouse 

buildings, and an exterior training area known as the Military Operations on Urban Terrain (MOUT) 

range. The facility is primarily unpaved, with the exception of the main road and the parking lot 

surrounding the building. Numerous shipping containers at the MOUT range are used for military 

operations and firefighting training; access to the facility is not controlled. Biak Training Center 

Brett Hall draws drinking water from one well that receives no treatment and has a septic system 

discharging to an adjacent leach field.

The state mission of Biak Training Center Brett Hall is to provide community and training support 

for citizens and organizations of the state and US. The federal mission of Biak Training Center 

Brett Hall is to provide facilities and resources for a training center contributing readiness and 

military capability for the armed forces of the state and US (OMD, 2018a). Training at Biak Training 

Center Brett Hall includes military personnel and civilian personnel, such as law enforcement, fire 

departments, state agencies, and non-DoD federal agencies.

The US Forest Services (USFS) Engine Academy conducted annual fire training at the MOUT 

range from 2010 to 2015. The annual training included local fire departments and local law 

enforcement agencies (city/county/state agencies), and it was facilitated by OMD. Annual bomb 

squadron training occurred at the MOUT in 2016 and 2017 and included local law enforcement 

led by the Federal Bureau of Investigation (FBI). Aqueous film-forming foam (AFFF) has been 

used for training purposes at the Engine Academy fire training area (FTA) and bomb squad 

training area. 

A dedicated Wildland Fire Program is located at the facility and has the mission of providing safety 

and training resources. The program provides wildland fire suppression and supports military 

training operations during fire seasons. The OMD collaborates with the Bureau of Land 

Management (BLM) Prineville District for ecosystem management (OMD, 2018b). The OMD also 

collaborates with the USFS and local fire departments for fire response. According to interviews 

conducted with the OMD Fire Officer, OMD fire rangers respond to fire emergencies in the area 

as necessary (if other agencies are not available). 

The Biak Training Center Brett Hall property is owned by the federal government and was

administered by the US Army Corps of Engineers (USACE), with licensing use to the OMD since 

2002. Biak Training Center Brett Hall is within the Biak Training Center, which is comprised of 

4,300 acres owned by the BLM Prineville and leased to the OMD. 

Based on review of historical aerial photographs, development of the installation appears as early 

as 1994, with the main building, two warehouse structures, and the paved roadway; development 

of the MOUT range appears by 2006. The facility appears to be in similar configuration as 

observed during the site visit (Environmental Data Resources, Inc. TM [EDRTM], 2018a; Google 

Earth, 2018).
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 2-2

2.2 Facility Environmental Setting

Biak Training Center Brett Hall is located in the Deschutes Columbia Plateau geologic province 

of Oregon (Oregon Department of Environmental Quality [DEQ], 2013; US Department of Interior 

[USDI], 2018) and bordered by undeveloped land along all four sides. Biak Training Center Brett 

Hall is comprised mostly of undeveloped, vegetated land underlain by volcanic lava flow beds. 

Paved areas at the facility include the road to enter/exit the facility from the northwest and 

southwest and the parking area surrounding the main building; the paved areas at the facility are 

primarily flat. From west to east, elevation at the facility ranges from approximately 3,080 and 

increases to 3,100 feet above mean sea level (amsl). From north to south, elevation ranges from 

approximately 3,085 and increases to approximately 3,095 feet amsl (Figure 2-2). Elevation 

throughout the facility averages 3,100 feet amsl. Topography at the facility follows a northwest 

gradient (Google Earth, 2018; EDRTM, 2018b).

2.2.1 Geology

Biak Training Center Brett Hall is in a geologic area characterized as basalt and basaltic andesite 

of the Pleistocene to Holocene ages (Figure 2-3). This geologic feature occurs primarily along 

the crest of the Cascade Range, located to the west of the facility (US Geological Survey [USGS], 

2018a). These basaltic lava flows are the most widespread types of surface geology in the region, 

with the oldest basalt lava flows exposed west of the Deschutes River (west of the facility). Vents 

associated with the lava flows are dispersed throughout the region as lava and cinder cones. 

Known as “Lava Badlands”, basalt from fissure eruptions cover the region, generally as thin 

sheets of pahoehoe flows where the surface appears ropy. The lava flows were estimated to 

extend from the land surface to 50 to 100 feet below ground surface (bgs). The Lava Badlands 

consist of a lava tube system, indicative of a lateral spread of lava. The Redmond Caves is one 

such lava tube system, located approximately 4 miles northwest of Biak Training Center Brett Hall 

(Department of Geology and Mineral Industries [DOGAMI], 1976). 

Biak Training Center Brett Hall is underlain by volcanic deposits of the Quaternary period of the 

Cenozoic era (EDRTM, 2018b). These deposits constitute the second major composite 

stratigraphic unit in the region, which is reported as extending to depths over 2,000 feet in some 

areas. This composition is comprised of lava flows, domes, vent deposits, pyroclastic deposits, 

and volcanic sediments (USGS, 2001). The volcanic rocks consist of ash and cinders, while the 

sedimentary rocks consist of semi-consolidated sand and gravel eroded from volcanic rocks 

(USGS, 1994, 2018b). 

Soils beneath Biak Training Center Brett Hall consist primarily of Stukel-Deschutes complex within 

most of the facility boundary and Stukel-Rock outcrop-Deschutes complex in the eastern portion 

of the facility (US Department of Agriculture [USDA], 1999). Both soil series consist of shallow, 

well-drained soils with moderately rapid permeability located in lava plains that formed in ash 

(USDA, 1999). The Deschutes complex is characterized as sandy loam in the top 31 inches, 

followed by basalt at 31 inches. The Stukel complex is characterized as sandy and cobbly sandy 

loam in the top 11 inches, followed by gravelly sandy loam to 18 inches bgs and basalt at 18 

inches bgs. Bedrock of the Deschutes series is reported at 20 to 40 inches bgs, while bedrock of 

the Stukel series is reported at 10 to 20 inches bgs (USDA, 1999). Boring logs available online at 

the Oregon Water Resources Department (OWRD) website indicate local soil thickness is highly 

variable and generally greater than 2 feet thick but potentially up to 20 feet thick (OWRD, 2020). 

During the SI, basalt bedrock was observed as the dominant lithology below Biak Training Center

Brett Hall. The borings were completed at depths between 5 and 446.5 feet bgs. Sedimentary 

interbeds consisting of silty sand, poorly graded sandy, poorly graded sand, poorly graded gravel, 

well-graded sand, well-graded gravel, silt, siltstone, and sandstone were also observed within the 

bedrock at thicknesses ranging from a few inches to 24 feet. These observations are consistent 
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 2-3

with described in other studies. Samples for grain size analyses were collected at two locations, 

AOI01-01-SB-[1.7]-[2.2] and BCT-02-SB-[0]-[1.0], and analyzed via American Society for Testing 

and Materials (ASTM) Method D-422. Grain size results are pending from the laboratory and will 

be included in Appendix F, when received, in a later version of the SI Report. Boring logs are 

presented in Appendix E.

2.2.2 Hydrogeology

Biak Training Center Brett Hall is situated above the Deschutes Formation, which is the principal 

aquifer within the Upper Deschutes Basin. The Deschutes Formation comprises flood deposits, 

alluvium, debris flows, tephra, lava flows, and ignimbrites and ranges in thickness up to 2,000 

feet. The hydraulic conductivity ranges from less than 10 to approximately 1,900 feet per day 

(USGS, 2001). Because of the large amount of rainfall that occurs at the Upper Deschutes Basin 

and the highly permeable shallow rocks, the Cascade Range is the principal groundwater 

recharge area for the area. Groundwater from the Cascade Range flows through the permeable 

volcanic rock towards the east, into the Upper Deschutes Basin, where half of the volume 

discharges to streams, and the other half of the volume flows through the subsurface of the 

Deschutes Formation, eventually discharging to streams. Groundwater discharge to streams is 

the principal mechanism of groundwater losses in the system where stream elevation is lower 

than the groundwater table. Groundwater discharges to streams occurs to the west of Biak 

Training Center Brett Hall, surrounding the confluence of the Deschutes River (west of Bend). 

The Deschutes River maintains substantial flow during dry periods, and stream discharge varies 

by location and seasonal precipitation. Regionally, the water table fluctuates in association with 

recharge. Infiltration of precipitation in the region occurs from rainfall, snowmelt, canal and stream 

leaks, and irrigation water applied to farm fields. The USGS estimated annual recharge from 

infiltration of precipitation in the area surrounding the facility ranging from 3 to 4.5 inches. 

Recharge averages 35 to 40 percent (%) of the annual precipitation measured throughout the 

Upper Deschutes Basin (USGS, 2001). 

Based on regional studies, groundwater flow at the facility is inferred to generally flow to the 

northwest (USGS, 2001). Biak Training Center Brett Hall obtains drinking water through one 

onsite water supply well located in the north-central portion of the facility, in the northwest corner 

of the building (Well #1852) (Figure 2-3). This well was completed in January 1985 and drilled to 

a depth of 492 feet bgs; depth to first water was reported at 370 feet bgs (OWRD, 2018). Shallow 

or perched groundwater has not been documented at or in the vicinity of the facility, but is possible 

in complex volcanic formations. Boring logs for nearby wells (within 2 miles of the facility) available 

at the OWRD website indicated first encountered groundwater ranges from approximately 230 

feet bgs to over 480 feet bgs, but the geology is difficult to correlate between locations due to 

inconsistent lithologic characterization between drillers (OWRD, 2020). 

Several drinking water source areas with active public and private groundwater systems were 

identified near Biak Training Center Brett Hall, as follows: 

• Redmond Water Department (PWS ID OR4100693), approximately 2 miles to the 

northwest, with 9,800 connections serving approximately 30,000 people (DEQ, 2018a). 

• Avion WC Red Cloud (PWS ID OR4101203), approximately 2 miles to the northeast, with 

177 connections serving approximately 440 people (DEQ, 2018a). 

• ORARNG Central Oregon Unit Training Equipment Site (COUTES) private water supply 

(PWS ID OR41-05957), approximately 3 miles to the northwest, with a single connection 

(the COUTES facility) serving 20 people. The groundwater well serving the COUTES 

facility is state regulated (Oregon Health Authority [OHA], 2019). 
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 2-4

• Seven privately owned domestic wells located approximately 1 mile to the northwest 

serving multiple residential properties (OWRD, 2020). Twenty privately owned domestic 

wells located approximately 1 to 2 miles down gradient northeast (Figure 2-3). These 

wells have depths that range from 470 feet to 510 feet bgs and serve multiple residential 

properties.

Drinking water from the water well at Biak Training Center Brett Hall was sampled and analyzed 

by OMD for selected PFAS, including PFOS, PFOA, and PFBS, in 2017 and 2020. Drinking water 

samples are summarized as follows: 

• June 2017 drinking water sample: The water well was sampled on 27 June 2017. The 

sample was analyzed by USEPA 537 Modified for 20 PFAS, included PFOS, PFOA, and 

PFBS. The analytical data was validated and indicates all 20 PFAS, including PFOS, 

PFOA, and PFBS, were not detected above limits of detection (LOD), which ranged from 

0.985 nanograms per liter (ng/L) to 14.8 ng/L. PFOS was not detected above 2.83 ng/L 

and both PFOA and PFBS were not detected above 1.88 ng/L. All LODs were below SLs

presented in the OSD memorandum “Investigating Per- and Polyfluoroalkyl Substances 

within the Department of Defense Cleanup Program,” September 15, 2021 (Assistant 

Secretary of Defense, 2021).

• September 2020 drinking water sample: The water well was sampled on 23 September 

2020. The sample was analyzed at a NELAP-approved laboratory by USEPA 537. An 

unvalidated laboratory analytical report for one drinking water sample indicates the 14 

reported PFAS, including PFOS, PFOA, and PFBS, were not detected above LODs 

ranging from 2.0 ng/L to 4.0 ng/L. PFOS, PFOA, and PFBS were not detected above 4.0 

ng/L. All LODs were below screening levels presented in the OSD memorandum 

“Investigating Per- and Polyfluoroalkyl Substances within the Department of Defense 

Cleanup Program,” September 15, 2021 (Assistant Secretary of Defense, 2021).

Depths to water measured in June 2022 during the SI ranged from 394.93 to 397.64 feet bgs. 

Groundwater elevation elevations from the SI are presented on Figure 2-4. Due to limited 

groundwater elevation data, groundwater contours could not be determined. The inferred 

groundwater flow direction, based on groundwater elevations calculated for wells BTC-MW001 

and AOI01-01 used in conjunction groundwater flow directions inferred in available regional 

studies, is to the northeast.

2.2.3 Hydrology

Biak Training Center Brett Hall is within the Town of O’Neill subwatershed (12-digit hydrologic unit 

code [HUC]: 170703051006), which is within the Mayfield Pond-Central Oregon Canal watershed 

(10-digit HUC: 1707030509) of the Lower Crooked subbasin (8-digit HUC: 17070305), of the 

Deschutes Basin (6-digit HUC: 170703) (Figure 2-5). No surface water features are located at 

the facility. The nearest off-site surface waterbodies are the North Unit Main Canal approximately 

2 miles to the west of the facility, which flows northeast, and the Central Oregon Canal about 1.75 

miles to the east, which flows northeast. The Deschutes River is located approximately 8 miles to 

the west of Biak Training Center Brett Hall, flows northeast, and is a major tributary to the 

Columbia River (located along the Oregon-Washington boarder) (DEQ, 2018b). No wetlands are 

located at the facility (USFS, 2018). 

The facility is primarily unpaved, but existing paved areas include the roadway entering/exiting 

the facility from the northwest and southwest and the parking area surrounding the building. 

Surface stormwater runoff from paved areas flows into stormwater catch basins surrounding the 

building, discharging to the west of the pavement (OMD, 2018c). Stormwater runoff to unpaved 

areas infiltrates the soil. Surface water runoff at Biak Training Center Brett Hall would only occur 

during heavy precipitation events where precipitation exceeds the infiltration rate of soil.
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 2-5

2.2.4 Climate

Climate in the Deschutes Basin is considered semiarid: moderate with cool, wet winters and 

warm, dry summers. The climate is driven by air masses that develop in the Pacific Ocean 

(approximately 150 miles west of Biak Training Center Brett Hall) and move east over the Cascade 

Range (approximately 35 miles west of Biak Training Center Brett Hall), dropping up to 200 inches 

of precipitation (rainfall and snow) annually (mostly snow during the winter). The Deschutes 

Basin’s climate experiences annual and long-term variability. Precipitation decreases east of the 

Cascade Range significantly (USDA, 1966; USGS, 2001).

Weather data recorded at the Redmond Airport weather station (Station OR USW00024230), 

located approximately 2 miles to the northwest of Biak Training Center Brett Hall, reported the 

following climatic measurements from 1990 to 2018: average annual precipitation of 8 inches, 

average annual snowfall of 9 inches, and average temperature of 49 degrees Fahrenheit (°F) 

(max of 86 °F) (National Oceanic and Atmospheric Administration [NOAA], 2018).

2.2.5 Current and Future Land Use

Biak Training Center Brett Hall lies along the western boundary of Crook County, bordering 

Deschutes County to the east. The nearest urban area is Redmond, approximately 4 miles to the 

northwest of the facility. The Redmond Airport is located approximately 2 miles to the northwest 

of the facility. According to the 2017 census conducted by the US Census Bureau (Census), the 

estimated population of Redmond at the time was 30,011. Based on the population estimates, 

Redmond’s population has increased by nearly 3,800 since 2010 (Census, 2018). Land use 

surrounding the facility is primarily agricultural and zoned by Crook County as EFU3 – Exclusive 

Farm Use (Crook County, 2018). Land within 0.25 miles west of Biak Training Center Brett Hall is 

zoned by Deschutes County as EFUAL – Alfalfa Subzone (Deschutes County, 2018). Highway 

126, which travels east/west from Redmond (west) to Prineville (east), is located 2 miles mile to 

the north of the facility. Future land use at Biak Training Center Brett Hall is not anticipated to 

change.

2.2.6 Sensitive Habitat and Threatened/ Endangered Species 

The following fishes, insects, and mammals are federally endangered, threatened, and/or are 

listed as candidate species in Crook County, Oregon (US Fish and Wildlife Service [USFWS], 

2023).

• Fishes: Bull Trout, Salvelinus confluentus (threatened)

• Insects: Monarch butterfly, Danaus plexippus (candidate)

• Mammals: Gray wolf, Canis lupus (endangered)

2.3 History of PFAS Use

Three AOIs were identified where AFFF may have been used, stored, disposed, or released 

historically at the Biak Training Center Brett Hall (AECOM, 2019). AFFF has historically been 

released at the facility during fire training activities and bomb squad training activities as early as 

2000. A description of each AOI is presented in Section 3.
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 2-6

THIS PAGE INTENTIONALLY BLANK
Biak Training Center Brett Hall

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

AP

1/10/2023

1/10/2023

PROJECT Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1:12,000

1/10/2023 ­ Figure 2-1 PM CM 1/10/2023

12420 Milestone Center Drive

Germantown, MD 20876

Facility Location

Sources: Esri, HERE, Garmin, USGS,

Intermap, INCREMENT P, NRCan, Esri

^_

0 500 1,000 2,000

Feet

Legend

Facility Boundary

AECOM 2-7
CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

AP

1/10/2023

1/10/2023

PROJECT Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1:12,000

1/10/2023 ­ Figure 2-2 PM CM 1/10/2023

12420 Milestone Center Drive

Germantown, MD 20876

Facility Topography

Copyright:© 2013 National Geographic

Society, i-cubed

0 500 1,000 2,000

Feet

Legend

Facility Boundary

AECOM 2-8
&<

&<

!P

!P

!P

!P

!P !P

!P

!P

!P

!P

!P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P!P

!P

!P

!P

!P

!P!P !P

!P !P

!P

!P !P

!P

!P !P !P

!P

!P !P 5!

5!

5!5!

!P

5!5!

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P !P

!P

5!

!P

!P

!P

!P

5!P

!P

!P

!P

!P

!P

!P

!P

!P !P

!P

!P

!P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P !P

!P

!!PP

!P

!P

!P

!P

!P

!P

!C(!P

!P

!P

!P !P !P

!P !P

5! !P P

5!

!P

!P

!P !P

!P

!P

!P

!P !P

!P

!P

!P

!P !P !P !P

!P

!C(!C(

!P

5

!P !P

!P

!P !P !P

!P

!P

!P !P

5! !P

!P 5!

!C(

!P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P!P

!P

!P

!P

5!

!P

!P !P

!P

!P

!P

!P !P

!P

!C(

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!C(

5!

!P !P

!P

!P

!P

!P

!P

!C(

5!

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!C(

!P

!P

!P

!P

!C(

!P

!P

!P

!P

5!

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P !P

!P

!P

!C(

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P !P !P

!P

!P

!P

!P

!P

5!

!P !P

!P !P!P

!P !P

!C(

!C(!P !P !P

!P !P !P

!P !P

!P !P !P

!P

!P

!P !P

!P !P

!C(

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P!P

!P

!P

!P

!P !P

!P

!P !P

!P !P

!P !P

!P !P

!P !P

!P

!P

!P

!P !C(

!P

!P

!P

!P

!P

!P

!P !P

!P

!P

!P

!P

!P!P

!P!P!P

!P

!P

!C( 5!

!P!P

!P !P !P

55!! !P

!P

!P !P

!P

!P !P

!P !P

5!

!P

!C(5!

!P

5!

!P

!P

!P

!P

5!

!P!P

!P!P

!P

!P

!P

!P

!P

!P

!P

!P !P !P

!P

!P

!P

!P

!P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!C(

!P

!P

5!

!P

!P

!P

!P

!P

!P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

5!

!P

!P

!P

!P !P

!P

!P !P

!P

!P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P !P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!C(

!P

!P

!P

!P

!P

!P

5!P 5!

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P !P

!P

!P

!P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

5!

!P

!C(

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P !P !P

!P

!P

!P

!P

!P

!P

!P

5!

!P

!P

!P

!P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

5!

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P!P

!P

!P

!P

!C(

!P

!P

!P

!P

!P

!P

5!

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!C(

!P

!P

!P

!P

!C( !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!C(

5!

!P

!P!P

!P

!P

!P

!P!P

!P!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

5!

!P

!P

!P!P

!P!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

5!5!

!P

!C(

!P

!P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!C(

!P

!P

!P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

5!

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P !P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P!P

!P !P

!P

!P!P

!P

!P

!P

!P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P !P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

!P

120°58'3.72"W

D ryRiver

LateralC

La t e arl E

Nor ht Unit Main Canal

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

AP

6/15/2023

6/15/2023

PROJECT Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1:95,040

6/15/2023 ­ Figure 2-3 PM CM 6/15/2023

12420 Milestone Center Drive

Germantown, MD 20876

Groundwater Features

Source: Esri, Maxar, Earthstar Geographics,

and the GIS User Community

0 0.75 1.5 3

Miles

Legend

Facility Boundary

Water Body

Wetland

River/Stream

Canal/Ditch

Inferred Groundwater Flow Direction

Geology

alluvial fan

Basalt

rhyolite

Well

!P Domestic Well

5! Industrial Well

5! Irrigation Well

!C( Community Well

&<

Potable Well

&<

AECOM 2-9
&<

A!

A!

BTC-MW001

2700.12

AOI01-01

2700.03

Water Well Potable

Brett Hall

NM

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

AP

1/5/2023

1/5/2023

PROJECT Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1:4,080

1/5/2023 ­ Figure 2-4 PM CM 1/5/2023

12420 Milestone Center Drive

Germantown, MD 20876

Groundwater Elevations,

June 2022

Source: Esri, Maxar, Earthstar Geographics,

and the GIS User Community

0 170 340 680

Feet

Legend

A! Permanent Monitoring Well

&<

Potable Well

Facility Boundary

Inferred Groundwater Flow Direction

Groundwater elevations in ft NAVD88.

NM = Not Measured

AECOM 2-10
Town of

O'Neil

Watershed

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

AP

1/10/2023

1/10/2023

PROJECT Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1:12,000

1/10/2023 ­ Figure 2-5

PM CM 1/10/2023

12420 Milestone Center Drive

Germantown, MD 20876

Surface Water Features

Source: Esri, Maxar, Earthstar Geographics,

and the GIS User Community

0 500 1,000 2,000

Feet

Legend

Facility Boundary

Surface Water Flow Direction

AECOM 2-11
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 2-12

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

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, two potential release areas were 

identified at Biak Training Center Brett Hall and designated as two AOIs (AECOM, 2019). A third 

potential release area and AOI was identified during the SI. The potential release areas are shown 

on Figure 3-1.

3.1 AOI 1 Engine Academy Training Area

AOI 1 is at the MOUT range approximately 660 feet southwest of the facility building. Releases 

of AFFF to soil by the USFS Engine Academy occurred at AOI 1 between 2000 and 2011 and 

between 2013 and 2015. The MOUT range (and surrounding area) is unpaved. According to 

interviewed facility personnel, no fires were set at this FTA, but AFFF was applied to wooden 

structures for training exercises to showcase applications of AFFF in fire situations. The 

concentration and amount of AFFF released during the training events are unknown based on 

interviews conducted with OMD facility personnel and USFS personnel.

3.2 AOI 2 Bomb Squad Training Area

AOI 2 is at the MOUT range located approximately 830 feet southwest of the facility building, 

adjacent to AOI 1. Releases of AFFF to soil occurred at AOI 2 during training events conducted 

by the FBI between 2016 and 2017. The MOUT range (and surrounding area) is unpaved. 

According to interviewed facility personnel, no fires were set at this training area, but AFFF was 

applied during bomb squad training exercises. The concentration and amount of AFFF released 

during the training events are unknown based on interviews conducted with OMD facility 

personnel. Interviews with FBI personnel were not conducted.

3.3 AOI 3 Range Control Infiltration Basin

During the SI, discussions with facility staff not interviewed during the PA noted that AFFF 

inadvertently introduced into a water tank truck was rinsed out onto the paved surface at Range 

Control. AFFF would have been captured by the stormwater system and discharged to a small 

infiltration basin west of Range Control. This area was subsequently added as an additional AOI 

(AOI 3). 
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 3-2

THIS PAGE INTENTIONALLY BLANK
&<

Town of

O'Neil

Watershed

Engine Academy Training Area

Bomb Squad Training Area

Range Control Infiltration Basin

AOI 1

AOI 2

AOI 3

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

AP

1/25/2023

1/25/2023

PROJECT Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1:12,000

1/25/2023 ­ Figure 3-1 PM CM 1/25/2023

12420 Milestone Center Drive

Germantown, MD 20876

Areas of Interest

Base Map: Source: Esri, Maxar, Earthstar

Geographics, and the GIS User Community

0 500 1,000 2,000

Feet

Legend

Area of Interest

Potential Release Area

Facility Boundary

Surface Water Flow Direction

Inferred Groundwater Flow Direction

&<

Potable Well

AECOM 3-3
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 3-4

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

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, 2022b), 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 Biak Training Center Brett Hall (AECOM, 2019);

• Analytical data collected from the onsite drinking water well at Biak Training Center Brett 

Hall in 2017 and 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, 2022b); 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). The scope of the SI was vertically bounded as follows: soil from sonic borings, surface soil 

(0 to 2 feet bgs), shallow subsurface soil (2 to 5 feet bgs), sedimentary interbeds (47 to 211 feet bgs), 

and groundwater (446 feet bgs).Temporal boundaries were limited to the spring 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, 2021a).

4.5 Data Usability Assessment

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

conclusion of data collection activities that uses the results of both data verification and validation 
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 4-2

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, 2022b).
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

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, Biak Training Center, Brett Hall, Oregon dated 

December 2019 (AECOM, 2019);

• Final Site Safety and Health Plan, Biak Training Center Brett Hall, Powell Butte, Oregon 

dated February 2022 (AECOM, 2022a); and

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

Biak Training Center Brett Hall, Powell Butte, Oregon dated March 2022 (AECOM, 2022b).

The SI field activities were conducted from 14 March 2022 to 22 June 2022 and consisted of utility 

clearance, sonic boring, soil sample collection, permanent monitoring well installation, groundwater 

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

QAPP Addendum (AECOM, 2022b), 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-one (31) soil samples from 12 boring locations;

• Two groundwater samples from two newly installed monitoring wells; 

• Nineteen (19) 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 Form

is provided in Appendix B3, land survey data are provided in Appendix B4. Additionally, a 

photographic log of field activities is provided in Appendix C.

5.1 Pre-Investigation Activities

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

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

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

5.1.1 Technical Project Planning

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

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

collection strategies; and 4.) finalizing the data collection plan. The process encourages 

stakeholder involvement in the SI, beginning with defining overall project objectives, including 

DQOs, and formulating a sampling approach to address the AOIs identified in the PA. 
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 5-2

A combined TPP Meeting 1 and 2 was held on 25 January 2022, 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, ORARNG, USACE, Oregon DEQ, and OHA.

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, 2022b).

A TPP Meeting 3 was held on TBD, 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 the Oregon One Call, the local utility clearance provider, to notify 

them of intrusive work on 1 March 2022. Additionally, AECOM contracted Ground Penetrating 

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

performed utility clearance of the proposed boring locations on 14 March 2022 with input from the 

AECOM field team and Biak Training Center Brett Hall 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

A potable water source at Biak Training Center Brett Hall was sampled on 4 February 2022 to 

assess usability for decontamination of drilling equipment. Results of the sample collected at the 

onsite production well spigot (BTC-DECON-01) confirmed this source to be acceptable 

(detections less than 1/5 of the SLs) for use in this investigation; therefore, it was used throughout 

the field activities. Due to slow flow rates from the spigot and a need for significant amount of 

water for drilling, OMD filled a 10,000-gallon non-potable water tank that is piped directly from the 

onsite production well for use during drilling activities. A separate sample (BTC-DECON-02) was 

collected from the non-potable tank on 14 March 2022 and results of this sample confirmed the 

tank to be acceptable for use in this investigation. Specifically, the samples were analyzed by 

LC/MS/MS compliant with QSM 5.3 Table B-15. The results of the decontamination water samples

associated with the onsite production well spigot and non-potable water tanks 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, 2022b). 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

Samples associated with AOI 3 were designated as surface soil samples only (0 to 2 feet bgs) 

which were collected via hand auger. Soil samples associated withAOI 1 and AOI 2 were collected 

via sonic drilling methods, in accordance with the SI QAPP Addendum (AECOM, 2022b). A Terra 

Sonic 150CC drill rig was used to collect continuous soil cores to the target depth. A hand auger 

was used to collect soil from the top 5 feet of the boring, in accordance with AECOM utility 

clearance procedures. The soil boring locations are shown on Figure 5-1, and depths are 

provided Table 5-1.
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 5-3

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 at the 

mid-point between the surface and the bedrock interface, and one subsurface soil sample at 

bedrock interface. If refusal was encountered at 6 feet bgs or shallower, only two samples were 

required to be collected per boring: one surface soil sample and one sample approximately 1-foot

above refusal. 

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.

Soil borings completed during the SI found basalt bedrock as the dominant lithology below the 

Biak Training Center Brett Hall. The borings were completed at depths between 5 and 446.5 feet 

bgs. Sedimentary interbeds consisting of silty sand, poorly graded sand, poorly graded gravel, 

well-graded sand, well-graded gravel, silt, siltstone, and sandstone were also observed within the 

bedrock at thicknesses ranging from a few inches to 24 feet. These observations are consistent 

with the understood depositional environment of the region.

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), pH (USEPA Method 9045D), and grain size (ASTM 

Method D-422) in accordance with the SI QAPP Addendum (AECOM, 2022b).

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

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

at a rate of 5% and analyzed for the same parameters as the accompanying samples. In instances 

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

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

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

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

Two borings (BTC-MW001 and BTC-02) were converted to permanent monitoring wells (BTCMW001 and BTC-MW002) as discussed in Section 5.3 below. All other borings were 

subsequently abandoned in accordance with the SI QAPP Addendum (AECOM, 2022b) using 

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

disturbing concrete or asphalt surfaces.

5.3 Permanent Well Installation and Groundwater Sampling

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

source areas. The locations of the wells are shown on Figure 5-2. 

A Terra Sonic 150CC drill rig was used to install two 4-inch diameter monitoring wells. The 

monitoring wells were constructed with Schedule 80 polyvinyl chloride (PVC), flush threaded 20-

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

8/12 silica sand was installed in the annulus around the well screen to a minimum of 2-foot above 

the well screen. 

A 2-foot-thick layer of 20/40 silica sand was placed above the filter pack. Bentonite grout was 

placed in the well annulus from the top of the 20/40 sand to 3 feet bgs, and concrete was placed 
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 5-4

from 3 feet bgs to the ground surface. The bentonite grout was allowed to set for 24 hours prior 

to well completion in accordance with the SI QAPP Addendum (AECOM, 2022b). The monitoring 

wells were constructed with a stick-up completion. The screen interval of each of the groundwater 

monitoring wells is provided in Table 5-2.

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

(AECOM, 2022b). The newly installed monitoring wells were developed no sooner than 24 hours 

following installation by pumping and surging using a variable speed submersible pump. Samples 

were collected no sooner than 24 hours following development via low-flow sampling methods 

using a Solinst double valve pump with disposable PFAS-free, HDPE tubing. New tubing was 

used at each well and the pumps were decontaminated between each well. The wells were purged 

at a rate determined in the field to reduce draw down prior to sampling. Water quality parameters 

(e.g., temperature, turbidity, 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). Water levels were measured to the nearest 0.01 inch and recorded. Additionally, 

a subsample of each groundwater sample was collected in a separate container and a shaker 

test was completed to identify if there 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, 2022b).

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.

5.4 Synoptic Water Level Measurements

A synoptic groundwater gauging event was performed on 22 June 2022. Groundwater elevation 

measurements were collected from the two new monitoring wells. Water level measurements 

were taken from the northern side of the well casing. A groundwater elevation 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 Oregon-licensed land surveyors following 

guidelines provided in the SOPs provided in the SI QAPP Addendum (AECOM, 2022b). Survey 

data from the newly installed wells on the facility were collected on 22 June 2022 in the applicable 

Universal Transverse Mercator zone projection with World Geodetic System 1984 (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, 2022b) and with the DA Guidance for 

Addressing Releases of PFAS, Q18 (DA, 2018).
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 5-5

Soil IDW (i.e., soil cuttings) generated during the SI activities were contained in labeled, 55-gallon 

Department of Transportation (DOT)-approved steel drums and left onsite in a designated waste 

storage area. Rock core was stored on and covered with thick mil plastic sheeting. The soil and 

rock IDW was not sampled and assumes the characteristics of the associated soil and 

sedimentary interbed samples collected from that source location. ARNG will coordinate waste 

profiling, transportation, and disposal of the solid IDW. 

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

decontamination fluids) were contained in labeled, 55-gallon DOT-approved steel drums or 275-

gallon poly totes, and left onsite in a designated waste storage area. The liquid IDW was not 

sampled and assumes the characteristics of the associated groundwater samples collected from 

that source location. Containerized liquid IDW will be managed and disposed of by ARNG (either 

by offsite disposal or onsite disposal with treatment, as appropriate) under a separate contract in 

accordance with SOP No. 042A (EA, 2021).

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

One deviation from the SI QAPP Addendum was identified during review of the field 

documentation. The deviation is noted below and is documented in a Field Change Request Form 

(Appendix B3):

• During the start of field activities in March 2022, discussion with facility staff not interviewed 

during the PA concluded AOI 2 was more frequently used for training utilizing AFFF over a 

wider area. It was suggested to add additional soil borings and adjust the proposed location 

of BTC-MW002. Additionally, AFFF inadvertently introduced into a water tank truck was 

rinsed out onto the paved surface at Range Control. AFFF would have been captured by 

the stormwater system and discharged to a small infiltration basin west of Range Control. 

As a result of this discussion, the following changes occurred:

• Boring location AOI01-04 was added to increase the soil boring density and 

distribution within AOI 1. 

• The installation of monitoring well BTC-MW002 was removed from location AOI01-

01 and moved to a new location within AOI 2. 

• Boring location AOI02-03 was moved further south to increase soil boring density 

and distribution withing AOI 2. 

• A new AOI (AOI 3) was added to capture the potential release area near Range 

Control. AOI 3 included two surface soil sampling locations (AOI03-01, AOI03-02) 

and one sediment sampling location (AOI03-03, sediment from inside the stormwater 

pipe discharging into the infiltration basin). 
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 5-6

THIS PAGE INTENTIONALLY BLANK
Table 5-1

Site Inspection Samples by Medium

Site Inspection Report, Biak Training Center Brett Hall, Oregon

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-0.5-1.0 3/15/2022 9:30 0.5 - 1.0 x

AOI01-01-SB-1.7-2.2 3/15/2022 14:00 1.7 - 2.2 x

AOI01-01-SB-1.7-2.2 3/16/2022 9:15 1.7 - 2.2 x x x

AOI01-01-SB-2.5-3.0 3/15/2022 14:45 2.5 - 3.0 x

AOI01-02-SB-0.5-1.0 3/15/2022 9:45 0.5 - 1.0 x

AOI01-02-SB-1.5-2.0 3/15/2022 15:15 1.5 - 2.0 x

AOI01-02-SB-2.5-3.0 3/15/2022 10:30 2.5 - 3.0 x

AOI01-03-SB-0.5-1.0 3/15/2022 10:00 0.5 - 1.0 x

AOI01-03-SB-1.5-2.0 3/15/2022 12:15 1.5 - 2.0 x

AOI01-03-SB-4.5-5.0 3/16/2022 11:00 4.5 - 5.0 x

AOI01-04-SB-0.5-1.0 3/15/2022 10:45 0.5 - 1.0 x

AOI01-04-SB-1.5-2.0 3/15/2022 11:00 1.5 - 2.0 x

AOI01-04-SB-1.5-2.0-D 3/15/2022 12:00 1.5 - 2.0 x FD

AOI01-04-SB-4.5-5.0 3/15/2022 13:30 4.5 - 5.0 x

AOI02-01-SB-0.5-1.0 3/15/2022 16:25 0.5 - 1.0 x

AOI02-01-SB-2.5-3.0 3/16/2022 11:30 2.5 - 3.0 x

AOI02-02-SB-0.5-1.0 3/15/2022 16:35 0.5 - 1.0 x

AOI02-02-SB-0.5-2.0 3/16/2022 11:45 0.5 - 2.0 x

AOI02-02-SB-2.5-3.0 3/16/2022 12:00 2.5 - 3.0 x

AOI02-03-SB-0.5-1.0 3/16/2022 7:50 0.5 - 1.0 x

AOI02-03-SB-0.5-1.0-MS 3/16/2022 7:50 0.5 - 1.0 x MS

AOI02-03-SB-0.5-1.0-MSD 3/16/2022 7:50 0.5 - 1.0 x MSD

AOI02-03-SB-1.0-1.5 3/18/2022 14:40 1.0 - 1.5 x

AOI02-03-SB-2.0-2.5 3/18/2022 14:45 2.0 - 2.5 x

AOI03-01-SB-0.0-1.0 3/18/2022 11:45 0 - 1.0 x

AOI03-01-SB-0.0-1.0-D 3/18/2022 11:45 0 - 1.0 x FD

AOI03-02-SB-0.0-0.7 3/18/2022 12:00 0 - 0.7 x

AOI03-02-SB-0.0-0.7-MS 3/18/2022 12:00 0 - 0.7 x MS

AOI03-02-SB-0.0-0.7-MSD 3/18/2022 12:00 0 - 0.7 x MSD

AOI03-03-SB-0.0-0.5 3/18/2022 11:30 0 - 0.5 x

BTC-02-SB-0.0-1.02 3/16/2022 8:30 0 - 1.0 x x x

BTC-02-SB-0.0-1.0-D2 3/16/2022 8:30 0 - 1.0 x x FD

BTC-02-SB-4.5-5.02 5/18/2022 8:30 4.5 - 5.0 x

BTC-02-SB-35-362 5/18/2022 16:30 35 - 36 x

BTC-02-SB-94-962 5/23/2022 10:00 94 - 96 x

BTC-02-SB-210-2112 5/25/2022 16:00 210 - 211 x

BTC-02-SB-210-211-MS2 5/25/2022 16:00 210 - 211 x MS

BTC-02-SB-210-211-MSD2 5/25/2022 16:00 210 - 211 x MSD

BTC-MW001-SB-47-49 3/18/2022 16:00 47 - 49 x

BTC-MW001-SB-124-126 3/30/2022 14:00 124 - 126 x

BTC-MW001-SB-224-226 4/1/2022 16:00 224 - 226 x

AOI01-01-GW1 6/21/2022 11:35 NA x

AOI01-01-GW-D1 6/21/2022 13:00 NA x FD

AOI01-01-GW-MS1 6/21/2022 13:00 NA x MS

AOI01-01-GW-MSD1 6/21/2022 13:00 NA x MSD

BTC-MW001-GW 6/21/2022 10:45 NA x

Soil Samples

Groundwater Samples

AECOM 5-7
Table 5-1

Site Inspection Samples by Medium

Site Inspection Report, Biak Training Center Brett Hall, Oregon

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

BTC-DECON-01 2/4/2022 11:23 NA x production well 

spigot

BTC-DECON-02 3/14/2022 14:30 NA x non-potable tank

BTC-ERB-01 3/16/2022 16:20 NA x hand auger

BTC-ERB-02 3/16/2022 16:30 NA x trowel

BTC-ERB-03 6/10/2022 8:00 NA x drill bit

BTC-ERB-04 6/21/2022 11:35 NA x pump

Notes:

1. Groundwater sample AOI01-01-GW and associated FD, MS, MSD samples were collected from monitoring well BTC-MW002.

2. Soil boring BTC-02 associated with monitoring well BTC-MW002.

AOI = area of interest

ASTM = American Society for Testing and Materials

bgs = below ground surface

BTC = Biak Training Center

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

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

Site Inspection Report, Biak Training Center Brett Hall, Oregon

Area of 

Interest

Boring 

Location

Soil Boring 

Depth 

(feet bgs)

AOI01-01 5AOI01-02 6AOI01-03 5AOI01-04 6

BTC-MW001 446.5

AOI02-01 5AOI02-02 5AOI02-03 5

BTC-021 446

AOI03-01 1AOI03-02 0.7AOI03-03 0.5

Notes:

1. Soil boring BTC-02 associated with monitoring well BTC-MW002.

AOI = area of interest

bgs = below ground surfaceBTC = Biak Training Center

btoc = below top of casingMW = monitoring wellNA = not applicableNAVD88 = North American Vertical Datum 1988

312

AECOM 
Table 5-3

Permanent Monitoring Well Screen Intervals and Groundwater Elevations

Site Inspection Report, Biak Training Center Brett Hall, Oregon

Area of 

Interest

Boring 

Location

Well Screen 

Interval 

(feet bgs)

Top of Casing 

Elevation 

(feet NAVD88)

Ground Surface 

Elevation 

(feet NAVD88)

Depth to 

Water

(feet btoc)

Depth to 

Water

(feet bgs)

1 BTC-MW001 426 - 446 3097.47 3095.05 397.35 394.93 

2 BTC-MW002 426 - 446 3099.90 3097.67 399.87 397.64 

Notes:bgs = below ground surfaceBTC = Biak Training Center

btoc = below top of casingMW = monitoring wellNA = not applicableNAVD88 = North American Vertical Datum 1988

AECOM 
A!

A!

"S

"S

"S

"S

"S

"S

"S "S "S

"S

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[

[

[ [ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [

[ [ [ [

[ [ [ [ [ [ [ [ [

[

[

AOI 1

AOI 2

AOI 3

BTC-MW001

BTC-MW002/BTC-02

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI02-02

AOI02-03

AOI03-01

AOI03-02

AOI03-03

AOI01-01

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

AP

1/25/2023

1/25/2023

PROJECT Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1:2,400

1/25/2023 ­ Figure 5-1 PM CM 1/25/2023

12420 Milestone Center Drive

Germantown, MD 20876

Site Inspection Sample Locations

Source: Esri, Maxar, Earthstar Geographics,

and the GIS User Community

0 100 200 400

Feet

Legend

A! Permanent Monitoring Well

"S Soil Sample

Area of Interest

Facility Boundary

[ Fence

Surface Water Flow Direction

Inferred Groundwater Flow Direction

AECOM 5-11
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 5-12

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

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.) Screening values for HFPO-DA were established after SI planning and execution and thus not included as an analyte. 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

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 6-2

6.2 Soil Physicochemical Analyses

To provide basic soil parameter information, soil samples were analyzed for TOC, pH, and grain 

size, which are important for evaluating transport through the soil medium. Appendix F contains 

the results of the TOC, pH, and grain size sampling. Grain size results are pending from the 

laboratory and will be included, when received, in a later version of the SI Report. 

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: Engine Academy Training Area. 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

Soil was sampled from surface soil (between 0.5 to 2.2 feet bgs) and shallow subsurface soil 

(between 2.5 to 5 feet bgs) from boring locations AOI01-01 through AOI01-04. Soil was also 

sampled from deep subsurface soil intervals (between 47 to 226 feet bgs) from boring location

BTC-MW001. 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.

PFOA and PFNA were detected below their SLs in surface soil at AOI01-03 (0.5 to 1 feet bgs), 

with concentrations of 0.148 J micrograms per kilogram (μg/kg) and 0.168 J μg/kg, respectively.

PFOS, PFHxS, and PFBS were not detected in surface soil. PFOA, PFOS, PFHxS, PFNA, and 

PFBS were not detected in shallow subsurface soil or deep subsurface soil. 

6.3.2 AOI 1 Groundwater Analytical Results

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

summarizes the groundwater results. Groundwater was sampled from permanent monitoring well

BTC-MW001. PFOA, PFOS, PFBS, PFHxS, and PFNA were not detected in groundwater.

6.3.3 AOI 1 Conclusions

Based on the results of the SI, PFOA and PFNA were detected in soil below their SLs. PFOA, 

PFOS, PFBS, PFHxS, and PFNA were not detected in groundwater. Therefore, no further 

evaluation at AOI 1 is warranted.
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 6-3

6.4 AOI 2

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

AOI 2: Bomb Squad Training Area. 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

Soil was sampled from surface soil (between 0.5 to 2 feet bgs) and shallow subsurface soil 

(between 2 to 5 feet bgs) from boring locations AOI02-01 through AOI02-03 and BTC-02. Soil was 

also sampled from deep subsurface soil intervals (between 35 to 211 feet bgs) from boring 

location BTC-02. 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.

PFOS and PFHxS were detected below their SLs in surface soil at BTC-02, with concentrations 

of 0.219 J μg/kg and 0.088 J μg/kg, respectively. PFOA, PFNA, and PFBS were not detected in 

surface soil. PFOA, PFOS, PFHxS, PFNA, and PFBS were not detected in shallow subsurface 

soil. PFOS was detected in deep subsurface soil at BTC-02, with a concentration of 0.144 J μg/kg.

This low level detection, which was collected from within a coarse sand interbed, may be attributed 

to drilling mud circulation or matrix interference during laboratory analysis. PFOA, PFHxS, PFNA, 

and PFBS were not detected in deep subsurface soil. 

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 permanent monitoring well 

BTC-MW002 (sample inadvertently labeled AOI01-01-GW). PFOA, PFOS, PFBS, PFHxS, and 

PFNA were not detected in groundwater. 

6.4.3 AOI 2 Conclusions

Based on the results of the SI, PFOS and PFHxS were detected in soil, at concentrations below 

their SLs. PFOA, PFOS, PFBS, PFHxS, and PFNA were not detected in groundwater. Therefore, 

no further evaluation at AOI 2 is warranted.

6.5 AOI 3

This section presents the analytical results for soil in comparison to SLs for AOI 3: Range Control 

Infiltration Basin. The results in soil and groundwater are presented in Table 6-2 and 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

Soil was sampled from surface soil (between 0 to 1 feet bgs) from boring locations AOI03-01 

through AOI03-03. Figure 6-1 through Figure 6-5 present the ranges of detections in soil. Table 

6-2 summarizes the soil results.

PFOA, PFOS, PFHxS, and PFNA were detected below their SLs in at least one surface soil 

sample, with the following maximum concentrations: PFOA at 0.474 J μg/kg, PFOS at 0.674 J 

μg/kg, PFHxS at 0.334 J μg/kg, and PFNA at 5.19 μg/kg. PFBS was not detected in surface soil. 
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 6-4

6.5.2 AOI 3 Conclusions

Based on the results of the SI, PFOA, PFOS, PFHxS, and PFNA were detected in soil, at 

concentrations below their SLs. Therefore, no further evaluation at AOI 3 is warranted.
Table 6-2

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

Site Inspection Report, Biak Training Center Brett Hall

Analyte OSD Screening 

Level a

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

Soil, LCMSMS compliant with QSM 5.3 Table B-15 (μg/kg)PFBS 1900 ND U ND U ND U ND U ND U ND U ND U ND U PFHxS 130 ND U ND U ND U ND U ND U ND U ND U ND U PFNA 19 ND U ND U ND U ND U 0.168 J ND U ND U ND U PFOA 19 ND U ND U ND U ND U 0.148 J ND U ND U ND U PFOS 13 ND U ND U ND U ND U ND U ND U ND U ND U 

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

PFBS perfluorobutanesulfonic a

References PFHxS perfluorohexanesulfonic a

PFNA perfluorononanoic acidPFOA perfluorooctanoic acidPFOS perfluorooctanesulfonic a

Interpreted Qualifiers Acronyms and Abbreviations

J = Estimated concentration AOI Area of InterestU = The analyte was not detected at a level greater than or equal to the adjusted DL BTC Biak Training Center

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 identificationLCMSMS liquid chromatography wiLOD limit of detectionND analyte not detected aboOSD Office of the Secretary of QSM Quality Systems ManualQual interpreted qualifierSB soil boringUSEPA United States Environmeμg/kg micrograms per kilogram

AOI01-01-SB-1.7-2.2-20220315

03/15/2022

1.7-2.2 ft

Area of Interest

Sample ID

Sample Date

Depth

AOI01-01-SB-0.5-1.0

03/15/2022

0.5-1 ft

AOI01-02-SB-0.5-1.0

03/15/2022

0.5-1 ft

AOI01-02-SB-1.5-2.0

03/15/2022

1.5-2 ft

03/15/2022

0.5-1 ft

AOI01-03-SB-0.5-1.0

03/15/2022

0.5-1 ft

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.

AOI01 

AOI01-04-SB-1.5-2

03/15/2022

1.5-2 ft

AOI01-03-SB-1.5-2.0

03/15/2022

1.5-2 ft

AOI01-04-SB-0.5-1.0

AECOM 
Table 6-2

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

Site Inspection Report, Biak Training Center Brett Hall

Analyte OSD Screening 

Level a

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

Soil, LCMSMS compliant with QSM 5.3 Table B-15 (μg/kg)PFBS 1900 ND U ND U ND U ND U ND U ND U ND U ND U ND U NPFHxS 130 ND U ND U ND U ND U ND UJ 0.088 J ND U ND U ND U 0PFNA 19 ND U ND U ND U ND U ND U ND U 0.154 J 0.164 J 0.639 J 5PFOA 19 ND U ND U ND U ND U ND U ND U ND U ND U ND U 0PFOS 13 ND U ND U ND U ND U ND UJ 0.219 J 0.146 J 0.143 J 0.154 J 0

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

PFBS p

References PFHxS p

PFNA pPFOA pPFOS p

Interpreted Qualifiers Acronyms and Abbreviations

J = Estimated concentration AOI AU = The analyte was not detected at a level greater than or equal to the adjusted DL BTC BUJ = 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 d

DL d

Notes ft f

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

ID idLCMSMS lLOD lND aOSD OQSM QQual iSB sUSEPA Uμg/kg m

Area of Interest

Sample ID

Sample Date

Depth

03/15/2022

0.5-1 ft

AOI02

03/16/2022

0.5-2 ft

AOI03-01-SB-0.0-1.0

03/18/2022

0-1 ft

AOI02-03-SB-1.0-1.5

03/18/2022

1-1.5 ft

AOI03-01-SB-0.0-1.0-D

03/18/2022

0-1 ft

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.

AOI03

AOI03-02-SB-0.0-0.7

03/18/2022

0-0.7 ft

AOI02-03-SB-0.0-1.0

03/16/2022

0.5-1 ft

AOI02-02-SB-0.5-1.0 AOI02-02-SB-0.5-2.0 BTC-02-SB-0.0-1.0 BTC-02-SB-0.0-1.0-D

03/16/2022 03/16/2022

0-1 ft 0-1 ft

AECOM 
Table 6-3

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

Site Inspection Report, Biak Training Center Brett Hall

Analyte OSD Screening 

Level a

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

PFBS 25000 ND U ND U ND U ND U ND U ND U ND U ND UPFHxS 1600 ND U ND U ND U ND U ND U ND U ND U ND UPFNA 250 ND U ND U ND U ND U ND U ND U ND U ND UPFOA 250 ND U ND U ND U ND U ND U ND U ND U ND UPFOS 160 ND U ND U ND U ND U ND U ND U ND U ND U

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

PFBS perfluorobutanesulfonic acid

References PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acidPFOA perfluorooctanoic acidPFOS perfluorooctanesulfonic acid

Interpreted Qualifiers Acronyms and Abbreviations

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

BTC Biak Training Center

Notes D duplicate

ND = Analyte not detected above the LOD. LOD values are presented in Appendix F. DL detection limit

ft feetHQ hazard quotientID identificationLCMSMS liquid chromatography with tandem mLOD limit of detectionND analyte not detected above the LODOSD Office of the Secretary of DefenseQSM Quality Systems ManualQual interpreted qualifierSB soil boringUSEPA United States Environmental Protectioμg/kg micrograms per kilogram

Area of Interest AOI02

Sample ID

Sample Date

Depth

AOI01-01-SB-2.5-3.0

03/15/2022

2.5-3 ft 4.5-5 ft

AOI02-01-SB-2.5-3.0

03/16/2022

2.5-3 ft

AOI01-02-SB-2.5-3.0

03/15/2022

2.5-3 ft

AOI01-03-SB-4.5-5.0

03/16/2022

4.5-5 ft

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

BTC-02-SB-4.5-5.0

05/18/2022

4.5-5 ft

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

AOI02-02-SB-2.5-3.0

03/16/2022

2.5-3 ft

AOI02-03-SB-2.0-2.5

03/18/2022

2-2.5 ft

AOI01-04-SB-4.5-5.0

03/15/2022

AECOM 
Table 6-4

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

Site Inspection Report, Biak Training Center Brett Hall

Area of Interest

Sample ID

Sample Date

Depth

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

PFBS ND U ND U ND U ND U ND U ND U

PFHxS ND U ND U ND U ND UJ ND U ND UPFNA ND U ND U ND U ND UJ ND U ND UPFOA ND U ND U ND U ND UJ ND U ND U

PFOS ND U ND U ND U ND UJ 0.144 J ND U

Interpreted Qualifiers Chemical AbbreviationsJ = Estimated concentration PFBS perfluorobutanesU = The analyte was not detected at a level greater than or equal to the adjusted DL PFHxS perfluorohexaneUJ = 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. PFNA perfluorononano

PFOA perfluorooctanoi

Notes PFOS perfluorooctanes

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

Acronyms and Abbreviations

AOI Area of InterestBTC Biak Training CeDL detection limitft feetID identificationLCMSMS liquid chromatogLOD limit of detectionND analyte not deteQSM Quality Systems Qual interpreted qualiSB soil boringμg/kg micrograms per 

03/30/2022 04/01/2022

47-49 ft 124-126 ft 224-226 ft

BTC-MW001-SB-47-49 BTC-MW001-SB-124-126 BTC-MW001-SB-224-226

AOI01

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

BTC-02-SB-210-211

05/25/2022

210-211 ft

BTC-02-SB-35-36

05/18/2022

35-36 ft

BTC-02-SB-94-96

05/23/2022

94-96 ft

AOI02

03/18/2022

AECOM 
Table 6-5

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

Site Inspection Report, Biak Training Center Brett Hall

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual

PFBS 601 ND U ND U ND UPFHxS 39 ND U ND U ND UPFNA 6 ND U ND U ND UPFOA 6 ND U ND U ND UPFOS 4 ND U ND U ND U

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

PFBS perfluorobutanesulfonic acid

References PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acidPFOA perfluorooctanoic acidPFOS perfluorooctanesulfonic acid

Interpreted Qualifiers Acronyms and Abbreviations

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

BTC Biak Training Center

Notes D duplicate

1. Sample AOI01-01-GW and the associated duplicate were collected from monitoring well BTC-MW002. DL detection limit

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

HQ hazard quotientID identificationLCMSMS liquid chromatography with tandem mLOD limit of detectionND analyte not detected above the LODOSD Office of the Secretary of DefenseQSM Quality Systems ManualQual interpreted qualifierUSEPA United States Environmental Protectiong/l nanogram per liter

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.

AOI02

AOI01-01-GW-D1

06/21/2022

Area of Interest

Sample ID

Sample Date

AOI01-01-GW1

06/21/2022

AOI01

BTC-MW001-GW

06/21/2022

AECOM 
AECOM 6-5

THIS PAGE INTENTIONALLY BLANK

OM 6-10
[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW002/BTC-02

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI02-02

AOI02-03

AOI03-01

AOI03-02

AOI03-03

AOI01-01

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI02-02

AOI02-03

AOI01-01

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

­ Figure 6-1

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1/12/2023

1/12/2023

1/12/2023

MS

AP

CM

GIS BY

CHK BY

PM

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

1/12/2023

1:3,000

Legend

[ Fence

Facility Boundary

PFOA Detections in Soil

12420 Milestone Center Drive

Germantown, MD 20876

0 125 250 500

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.

PFOA Results (μg/Kg)

ND

>ND - 19

>19 - 250

>250 - 2,500

>2,500

[ [ [ 

[ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

Extra Deep

AECOM 6-11
[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW002/BTC-02

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI02-02

AOI02-03

AOI03-01

AOI03-02

AOI03-03

AOI01-01

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI02-02

AOI02-03

AOI01-01

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

­ Figure 6-2

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1/12/2023

1/12/2023

1/12/2023

MS

AP

CM

GIS BY

CHK BY

PM

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

1/12/2023

1:3,000

Legend

[ Fence

Facility Boundary

PFOS Detections in Soil

12420 Milestone Center Drive

Germantown, MD 20876

0 125 250 500

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.

[ [ [ 

[ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

Extra Deep

PFOS Results (μg/Kg)

ND

>ND - 13

>13 - 160

>160 - 1,600

>1,600

AECOM 6-12
[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW002/BTC-02

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI02-02

AOI02-03

AOI03-01

AOI03-02

AOI03-03

AOI01-01

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI02-02

AOI02-03

AOI01-01

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

­ Figure 6-3

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1/12/2023

1/12/2023

1/12/2023

MS

MB

CM

GIS BY

CHK BY

PM

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

1/12/2023

1:3,000

Legend

[ Fence

Facility Boundary

PFBS Detections in Soil

12420 Milestone Center Drive

Germantown, MD 20876

0 125 250 500

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.

[ [ [ 

[ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

Extra Deep

PFBS Results (μg/Kg)

ND

>ND - 10

>10 - 1,900

>1,900 - 25,000

>25,000

AECOM 6-13
[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW002/BTC-02

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI02-02

AOI02-03

AOI03-01

AOI03-02

AOI03-03

AOI01-01

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI02-02

AOI02-03

AOI01-01

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

­ Figure 6-4

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1/12/2023

1/12/2023

1/12/2023

MS

AP

CM

GIS BY

CHK BY

PM

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

1/12/2023

1:3,000

Legend

[ Fence

Facility Boundary

PFHxS Detections in Soil

12420 Milestone Center Drive

Germantown, MD 20876

0 125 250 500

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.

[ [ [ 

[ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

Extra Deep

PFHxS Results (μg/Kg)

ND

>ND - 10

>10 - 130

>130 - 1,600

>1,600

AECOM 6-14
[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW002/BTC-02

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI02-02

AOI02-03

AOI03-01

AOI03-02

AOI03-03

AOI01-01

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

AOI01-02

AOI01-03

AOI01-04

AOI02-01

AOI02-02

AOI02-03

AOI01-01

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

­ Figure 6-5

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1/12/2023

1/12/2023

1/12/2023

MS

AP

CM

GIS BY

CHK BY

PM

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

1/12/2023

1:3,000

Legend

[ Fence

Facility Boundary

PFNA Detections in Soil

12420 Milestone Center Drive

Germantown, MD 20876

0 125 250 500

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.

[ [ [ 

[ [ [ [ [ [ [ [

[

[

[

[ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[

[ [ [ [ [ [

[

[

[

BTC-MW001

BTC-MW002/BTC-02

Extra Deep

PFNA Results (μg/Kg)

ND

>ND - 19

>19 - 250

>250 - 2,500

>2,500

AECOM 6-15
[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [

[ [ [ [ [ [ [ [

[ [ [ [

[

[

[ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [

[

[ [ [ [ [

[

BTC-MW001

BTC-MW002/BTC-02

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [

[ [ [ [ [ [ [ [

[ [ [ [

[

[

[ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [

[

[ [ [ [ [

[

BTC-MW001

BTC-MW002/BTC-02

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [ [

[

[ [ [ [ [ [ [

[

[

[ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [

[ [ [ [ [

[

BTC-MW001

BTC-MW002/BTC-02

­ Figure 6-6

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1/12/2023

1/12/2023

1/12/2023

MS

AP

CM

GIS BY

CHK BY

PM

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

1/12/2023

1:4,800

Legend

[ Fence

Facility Boundary

Inferred Groundwater Flow Direction

PFOA, PFOS, and PFBS Detections in Groundwater

12420 Milestone Center Drive

Germantown, MD 20876

0 200 400 800

Feet

PFOA PFOS PFBS

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

Groundwater sample ID AOI01-01-GW is associated with monitoring well BTC-MW002.

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 6-16
[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [ [ [ [ [

[ [ [ [ [ [ [

[

[

[ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[ [ [ [ [

[

BTC-MW001

BTC-MW002/BTC-02

[ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [ [ [ [ [ [

[ [ [ [ [ [ [

[

[

[ [ [ [ [

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[

[ [ [ [

[ [ [ [ [

[

BTC-MW001

BTC-MW002/BTC-02

­ Figure 6-7

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Biak Training Center Brett Hall in Powell Butte, OR

1/12/2023

1/12/2023

1/12/2023

MS

AP

CM

GIS BY

CHK BY

PM

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

1/12/2023

1:3,960

Legend

[ Fence

Facility Boundary

Inferred Groundwater Flow Direction

PFHxS and PFNA Detections in Groundwater

12420 Milestone Center Drive

Germantown, MD 20876

0 165 330 660

Feet

PFHxS PFNA

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

Groundwater sample ID AOI01-01-GW is associated with monitoring well BTC-MW002.

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 6-17
6-18

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 7-1

7. Exposure Pathways

The CSM for each AOI, revised based on the SI findings, is presented on Figure 7-1. Please note 

that while the CSM discussion assists in determining if a receptor may be impacted, the decision 

to move from SI to RI or interim action is determined 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, 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 2, and AOI 3

AOI 1 and AOI 2 are training areas where AFFF was applied during training exercises. AOI 3 is 

the infiltration basin where water would have discharged from rinsing a water tank truck impacted 

with AFFF. 
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 7-2

Relevant compounds were detected in surface soil at AOI 1, AOI 2, and AOI 3. Site workers and 

construction workers could contact constituents in surface soil via incidental ingestion and 

inhalation of dust. Therefore, the surface soil exposure pathway for site workers and construction 

workers are potentially complete. Since facility access is not controlled, trespassers could also 

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

surface soil exposure pathway for trespassers is potentially complete. The nearest residence is 

approximately 1-mile away; therefore, residents are unlikely to encounter soil via inhalation of 

dust and the exposure pathway is considered incomplete. PFOS was detected in deep subsurface 

soil (94 to 96 feet bgs) at AOI 1. Construction workers are not anticipated to come in contact with 

soil greater than 15 feet bgs; therefore, the subsurface soil exposure pathway for construction 

workers is considered incomplete. The CSM for AOI 1, AOI 2, and AOI 3 is presented on Figure 

7-1.

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 and AOI 2

The relevant compounds were not detected in groundwater samples collected at AOI 1 and AOI 

2. Therefore, the groundwater ingestion exposure pathway for all receptors is considered

incomplete. The CSM for AOI 1 and AOI 2 is presented on Figure 7-1.

7.3 Surface Water and Sediment Exposure Pathway

No surface water features are present at the facility or immediately downgradient of the facility; 

therefore, the surface water and sediment exposure pathways are considered incomplete for all 

receptors.
Media

SOURCE PATHWAY RECEPTOR

AOI 1

AOI 2

AOI 3

AFFF Training 

Exercises, AFFF 

Rinsed From 

Water Tank Truck

Surface soil

Human 

activities

Precipitation/ 

run-off

Leaching/ 

infiltration

Airborne soil 

particulate

Surface soil 

at AOI

Surface 

water/ 

sediment

Subsurface 

soil

Shallow 

groundwater

Source Release 

Mechanism Media Transport and Migration Media Exposure Routes

Inhalation of 

dust

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

/ / / /

Site Worker Construction Worker3 Resident1,2 Trespasser/ Recreational User1

Site Worker Construction Worker3 Resident1,2

/ / / /

/ / / /

/ / / /

/ / / /

LEGEND

Figure 7-1

Conceptual Site Model, AOI 1, AOI 2, and AOI 3

Biak Training Center Brett Hall

Potential 

Off-Facility 

Source Not 

under 

Control of 

ARNG

Trespasser/ Recreational User1

1. The resident and recreational users refer to offsite receptors.

2. Inhalation of dust for off-site receptors is likely

insignificant.

3. No current active construction at the facility.

Notes:

AECOM 7-3
AECOM 7-2

THIS PAGE INTENTIONALLY BLANK

OM 7-4
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

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 March 2022 to 22 June 2022 and consisted of utility 

clearance, sonic boring, soil sample collection, permanent monitoring well installation, groundwater 

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

QAPP Addendum (AECOM, 2022b), except as previously noted in Section 5.8. 

To fulfill the project DQOs set forth in the approved SI QAPP Addendum (AECOM, 2021a), samples 

were collected and analyzed for a subset of 18 compounds by LC/MS/MS compliant with QSM 5.3 

Table B-15 as follows. 

• Thirty-one (31) soil samples from 12 boring locations; 

• Two groundwater samples from two newly installed monitoring wells; 

• Nineteen (19) quality assurance 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 CSM was 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, no further evaluation under CERCLA is warranted for each of the 

three AOIs at this time (see Table 8-1). Based on the CSMs developed and revised in light of the 

SI findings, there is no 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:

• The detected concentrations of relevant compounds in soil at AOI 1 were below their 

SLs. 

• The relevant compounds were not detected in groundwater at AOI 1. 

• Based on the results of the SI, further evaluation of AOI 1 is not warranted. 

• At AOI 2:

• The detected concentrations of relevant compounds in soil at AOI 2 were below their 

SLs. 
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 8-2

• The relevant compounds were not detected in groundwater at AOI 2. 

• Based on the results of the SI, further evaluation of AOI 2 is not warranted. 

• At AOI 3: 

• The detected concentrations of relevant compounds in soil at AOI 3 were below their 

SLs. 

• Based on the results of the SI, further evaluation of AOI 3 is not warranted. 

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

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

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

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

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

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

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

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

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

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

AOI Potential 

Release Area

Soil –

Source 

Area

Groundwater – 

Source Area

Groundwater – 

Facility Boundary

Future 

Action

1 

Engine 

Academy 

Training Area

No 

further 

action

2 Bomb Squad 

Training Area N/A

No 

further 

action

3 

Range Control 

Infiltration 

Basin

N/A N/A

No 

further 

action

Legend:

N/A = not applicable 

= detected; exceedance of the screening levels

= detected; no exceedance of the screening levels

= not detected
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 9-1

9. References 

AECOM. 2018a. Final Site Inspection Programmatic Uniform Federal Policy-Quality Assurance 

Project Plan, Perfluorooctane Sulfonic Acid (PFOS) and Perfluorooctanoic Acid (PFOA) 

Impacted Sites ARNG Installations, Nationwide Contract No. W912DR-12-D-0014/

W912DR17F0192. 9 March.

AECOM. 2018b. Final Programmatic Accident Prevention Plan, Perfluorooctane Sulfonic Acid 

(PFOS) and Perfluorooctanoic Acid (PFOA) Impacted Sites ARNG Installations, Nationwide 

Contract No. W912DR-12-D-0014/W912DR17F0192. July.

AECOM. 2019. Final Preliminary Assessment Report, Biak Training Center, Brett Hall, Oregon. 

December. 

AECOM. 2022a. Final Site Safety and Health Plan, Biak Training Center Brett Hall, Powell Butte, 

Oregon, Perfluorooctane Sulfonic Acid (PFOS) and Perfluorooctanoic Acid (PFOA) Impacted 

Sites ARNG Installations, Nationwide. February 2022.

AECOM. 2022b. Final Site Inspection Quality Assurance Project Plan Addendum, Biak Training 

Center Brett Hall, Powell Butte, Oregon, Perfluorooctane Sulfonic Acid (PFOS) and 

Perfluorooctanoic Acid (PFOA) Impacted Sites ARNG Installations, Nationwide. March. 

Assistant Secretary of Defense. 2021. Investigation Per- and Polyfluoroalkyl Substances within 

the Department of Defense Cleanup Program. United States Department of Defense. 15 

September.

Assistant Secretary of Defense. 2022. Investigation Per- and Polyfluoroalkyl Substances within 

the Department of Defense Cleanup Program. United States Department of Defense. 

6 July. 

Census. 2018. America Fact Finder. Annual Estimates of the Residential Population, 2017 

Population Estimates. Available at 

https://factfinder.census.gov/faces/tableservices/jsf/pages/productview.xhtml?src=bkmk. 

Accessed November 12. 

Crook County. 2018. Online Property Information. Property records for 8540 SW Cavalry Way, 

Powell Butte, Oregon, account #770. Available at 

http://geo.maps.arcgis.com/apps/webappviewer/index.html?id=a52283adb31749bfb37d48f8

bcbf4a1f/. Accessed November 14.

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

4 September.

DEQ, 2013. Development of Oregon Background Metals Concentrations in Soil. 

DEQ. 2018a. Oregon Drinking Water Protection Program Interactive Map. Available at 

https://hdcgcx2.deq.state.or.us/HVR291/index.html?viewer=drinkingwater. Accessed 

November 12.

DEQ. 2018b. Stream Location Identification Tool. Available at 

http://hdcgcx2.deq.state.or.us/HVR291/?viewer=wqslit. Accessed November 13. 

Deschutes County. 2018. Online Property Information. Zoning Map. Available at 

http://dial.deschutes.org/Real/InteractiveMap. Accessed November 14
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 9-2

DoD. 2019a. Department of Defense (DoD), Department of Energy (DOE) Consolidated Quality 

Systems Manual (QSM) for Environmental Laboratories, Version 5.3. 

DoD. 2019b. General Data Validation Guidelines. Environmental Data Quality Workgroup. 

4 November.

DOGAMI. 1976. Geology and Mineral Resources of Deschutes County. Bulletin 89.

EA Engineering, Science, and Technology, Inc. 2021. Standard Operating Procedure No. 042A 

for Treating Liquid Investigation-Derived Material (purge water, drilling water, and 

decontamination fluids). Revision 1. March.

EDRTM. 2018a. EDRTM Aerial Photo Decade Package. Brett Hall, 2522 SE Jesse Butler Circle, 

Powell Butte, OR 97753. Inquiry Number 5464929.5. October 25, 2018.

EDRTM. 2018b. EDRTM Radius Map with Geocheck. Brett Hall, 2522 SE Jesse Butler Circle, 

Powell Butte, OR 97753. Inquiry Number 5464929.2. October 25, 2018.

Google Earth. 2018. Available at https://www.google.com/earth/. Accessed November 12. 

Guelfo, J.L. and Higgins, C.P. 2013. Subsurface Transport Potential of Perfluoroalkyl Acids at 

Aqueous Film-Forming Foam (AFFF)-Impacted Sites. Environmental Science and Technology 

47(9): 4164-71.

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

sediments. Environmental Science and Technology 40 (23): 7251-7256.

ITRC. 2018. Environmental Fate and Transport for Per- and Polyfluoroalkyl Substances. March. 

NOAA. 2018. National Centers for Environmental Information. Climate Data Online, Station 

Details, Global Summary of the Month. Available at https://www.ncdc.noaa.gov/cdo-web/. 

Accessed November 13. 

OHA. 2019. Oregon Public Health Drinking Water Data Online. Available at 

https://yourwater.oregon.gov/inventory.php. Accessed February 25. 

OMD. 2018a. Biak Training Center History. Available at 

https://www.oregon.gov/OMD/OTC/BIAK/Pages/History.aspx. Accessed October 15. 

OMD. 2018b. Biak Training Center Mission Statement. Available at 

https://www.oregon.gov/OMD/OTC/BIAK/Pages/default.aspx. Accessed October 9. 

OMD. 2018c. Facility Map Site #41902 Biak Training Center Brett Hall. 

OWRD. 2018. Well Report Query. Available at 

https://apps.wrd.state.or.us/apps/gw/well_log/Default.asp. Accessed October 4. 

OWRD. 2020. Well Report Query. Available at 

https://apps.wrd.state.or.us/apps/gw/well_log/Default.asp. Accessed November 6.

USACE. 2016. Technical Project Planning Process, EM-200-1-2. 26 February.

USDA. 1966. Natural Resources Conservation Service, Soil Survey of Prineville Area, Oregon. 

USDA. 1999. Natural Resources Conservation Service, Soil Survey of Upper Deschutes River 

Area, Oregon. 
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 9-3

USDI. 2018. National Park Service, Geologic Resources Division. Physiographic Provinces. 

Available at https://www.nps.gov/subjects/geology/physiographic-provinces.htm. Accessed 

November 14. 

USEPA. 1980. Comprehensive Environmental Response, Compensation, and Liability Act 

(CERCLA). 

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

40 CFR Part 300; 59 Federal Register 47384. September.

USEPA. 2001. Risk Assessment Guidance for Superfund, Volume I: Human Health Evaluation 

Manual (Part D, Standardized Planning, Reporting, and Review of Superfund Risk 

Assessments). December.USEPA. 2017. National Functional Guidelines for Organic 

Superfund Data Review. OLEM 9355.0-136, EPA-540-R-2017-002. Office of Superfund 

Remediation and Technology Innovation. January.

USEPA. 2017. National Functional Guidelines for Organic Superfund Data Review. OLEM 

9355.0-136, EPA-540-R-2017-002. Office of Superfund Remediation and Technology 

Innovation. January.

USFS. 2018. National Wetlands Inventory. Available at 

https://www.fws.gov/wetlands/data/mapper.html. Accessed November 13. 

USFWS. 2023. Species by County Report, County: Crook, Oregon. Environmental Conservation 

Online System. Accessed 3 January 2023 at https://ecos.fws.gov/ecp/report/species-listingsby-current-range-county?fips=41013. 

USGS. 1994. Ground Water Atlas of the United States: Idaho, Oregon, Washington, HA 730-H, 

Volcanic and Sedimentary Rock Aquifers. Available at 

https://pubs.usgs.gov/ha/ha730/ch_h/H-text4.html. Accessed November 12.

USGS. 2001. Groundwater Hydrology of the Upper Deschutes Basin, Oregon. Water-Resources 

Investigation Report 00-4162.

USGS. 2018a. Oregon Geologic Map Data. Available at 

https://mrdata.usgs.gov/geology/state/state.php?state=OR. Accessed November 12.

USGS. 2018b. Aquifers: Map of the Principal Aquifers of the United States. Available at 

https://water.usgs.gov/ogw/aquifer/map.html. Accessed November 12.

Xiao, F., Simcik, M. F., Halbach, T. R., and Gulliver, J. S. 2015, Perfluorooctane sulfonate (PFOS) 

and perfluorooctanoate (PFOA) in soils and groundwater of a U.S. metropolitan area: 

Migration and implications for human exposure. Water Research 72: 64-74. 
Site Inspection Report

Biak Training Center Brett Hall, Powell Butte, Oregon

AECOM 9-4

THIS PAGE INTENTIONALLY BLANK