FINAL

Site Inspection Report 

Tulsa Army Aviation Support 

Facility #2, Oklahoma

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

May 2023

Prepared for:

Army National Guard Bureau

111 S. George Mason Drive

Arlington, VA 22204

UNCLASSIFIED
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Table of Contents

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

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

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

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

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

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

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

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

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

2.2.3 Hydrology....................................................................................................2-3

2.2.4 Climate........................................................................................................2-4

2.2.5 Current and Future Land Use......................................................................2-4

2.2.6 Sensitive Habitat and Threatened/ Endangered Species.............................2-4

2.3 History of PFAS Use..............................................................................................2-4

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

3.1 AOI 1 Eastern Release Areas................................................................................3-1

3.1.1 Tri-Max Training Area 1 ...............................................................................3-1

3.1.2 Storage Hangar...........................................................................................3-1

3.1.3 Maintenance Hangar...................................................................................3-2

3.1.4 Wash Rack..................................................................................................3-2

3.1.5 Evaporator ..................................................................................................3-2

3.1.6 Building 100 ................................................................................................3-2

3.2 AOI 2 Western FTAs .............................................................................................3-2

3.2.1 Tri-Max Training Areas 2 and 3....................................................................3-3

3.3 AOI 3 HEMTT Storage ..........................................................................................3-3

3.3.1 HEMTT Storage ..........................................................................................3-3

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

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 Temporary Well Installation and Groundwater Grab Sampling...............................5-4

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

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

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

5.7 Laboratory Analytical Methods ..............................................................................5-5
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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 ......................................................................................6-3

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

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

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

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

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

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

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...........................................................................................................7-1

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

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

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

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

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

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

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

7.3.1 AOI 1 and AOI 2..........................................................................................7-4

7.3.2 AOI 3...........................................................................................................7-4

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

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

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

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

Appendix A Data Usability Assessment and Validation Reports

Appendix B Field Documentation

B1. Log of Daily Notice of Field Activities

B2. Sampling Forms

B3. Field Change Request Forms

B4. Survey Data

Appendix C Photographic Log

Appendix D TPP Meeting Minutes

Appendix E Boring Logs 

Appendix F Analytical Results

Appendix G Laboratory Reports

Figures

Figure 2-1 Facility Location

Figure 2-2 Facility Topography

Figure 2-3 Groundwater Features

Figure 2-4 Groundwater Elevations, April 2022

Figure 2-5 Surface Water Features

Figure 3-1 Areas of Interest

Figure 5-1 Site Inspection Sample Locations

Figure 6-1 PFOA Detections in Soil

Figure 6-2 PFOS Detections in Soil

Figure 6-3 PFBS Detections in Soil

Figure 6-4 PFHxS Detections in Soil

Figure 6-5 PFNA Detections in Soil

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

Figure 6-7 PFHxS and PFNA Detections in Groundwater

Figure 7-1 Conceptual Site Model, AOI 1

Figure 7-2 Conceptual Site Model, AOI 2

Figure 7-3 Conceptual Site Model, AOI 3

Tables

Table ES-1 

Table ES-2 

Table 5-1 

Table 5-2 

Table 6-1 

Table 6-2 

Table 6-3 

Table 6-4 

Screening Levels (Soil and Groundwater) 

Summary of Site Inspection Findings and Recommendations 

Site Inspection Samples by Medium 

Soil Boring Depths, Temporary Well Screen Intervals,and Groundwater 

Elevations 

Screening Levels (Soil and Groundwater) 

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

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

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

% percent

°C degrees Celsius

°F degrees Fahrenheit

μg/kg micrograms per kilogram

AASF Army Aviation Support Facility

AECOM AECOM Technical Services, Inc.

AFFF aqueous film-forming foam

amsl above mean sea level

ANGB Air National Guard Base

AOI Area of Interest

ARNG Army National Guard

ASTM American Society for Testing and Materials

bgs below ground surface 

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act 

CoC chain of custody

CSM conceptual site model

DA Department of the Army

DoD Department of Defense

DOT Department of Transportation

DQO data quality objective

DUA data usability assessment

ELAP Environmental Laboratory Accreditation Program

EM Engineer Manual

FedEx Federal Express

FTA Fire Training Area

GPRS Ground Penetrating Radar Systems

HDPE high-density polyethylene 

HEMTT heavy expanded mobile tactical truck

HFPO-DA hexafluoropropylene oxide dimer acid

IDW investigation-derived waste

ITRC Interstate Technology Regulatory Council

LC/MS/MS liquid chromatography with tandem mass spectrometry

MIL-SPEC military specification

MS matrix spike

MSD matrix spike duplicate

NELAP National Environmental Laboratory Accreditation Program

ng/L nanograms per liter

OKARNG Oklahoma Army National Guard

OKIE811 Oklahoma 811

OSD Office of the Secretary of Defense

OWS oil water separator

PA Preliminary Assessment

PFAS per- and polyfluoroalkyl substances
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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

SI Site Inspection

SL screening level

SOP standard operating procedure

RI Remedial Investigation

TOC total organic carbon

TPP Technical Project Planning

UFP Uniform Federal Policy

US United States

USACE United States Army Corps of Engineers

USCS Unified Soil Classification System

USEPA United States Environmental Protection Agency

USFWS United States Fish and Wildlife Service

WWTP wastewater treatment plant
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Executive Summary

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

Inspections (SIs) on the current or potential historical use of per- and polyfluoroalkyl substances 

(PFAS) with a focus on the six compounds presented in the memorandum from the Office of the 

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

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

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

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

, and perfluorobutanesulfonic acid 

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

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

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

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

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

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

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

screening levels for relevant compounds. This SI was completed at Tulsa Army Aviation Support 

Facility (AASF) #2 in Tulsa, Oklahoma and determined further investigation is warranted for AOI 

1: Eastern Release Area and AOI 2: Western Fire Training Areas (FTAs). No further evaluation 

is warranted for AOI 3: Heavy Expanded Mobility Tactical Truck (HEMTT) Storage at this time. 

Tulsa AASF #2 will also be referred to as the “facility” throughout this document.

Tulsa AASF #2 is located at 4220 North Mingo County Expressway, approximately 9 miles 

northeast of downtown Tulsa, Tulsa County, Oklahoma. The approximately 42-acre facility is 

situated at the junction of US Highway 169 and Oklahoma Highway 266 and is northeast of 

Tulsa International Airport, one mile east of Tulsa Air National Guard Base. Tulsa AASF #2 was 

built in 1987, and the Oklahoma ARNG moved into the facility in 1989. Prior to construction, the 

land was previously agricultural or undeveloped land (AECOM Technical Services, Inc., 2020).

The mission of AASF #2 is to support aviation equipment and machinery, as well as maintain 

properly trained and equipped units for mobilization. AASF #2 includes a storage hangar, 

maintenance hangar, HEMTT storage area, and an armory.

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

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

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

Investigation for AOI 1 and AOI 2. 

1 Of the six PFAS compounds presented in the 6 July 2022 OSD memorandum, HFPO-DA (commonly referred to as GenX) was not 

included as an analyte at the time of this SI. Based on the conceptual site model (CSM) developed during the PA and revised based 

on SI findings, the presence of HFPO-DA is not anticipated at the facility because HFPO-DA is generally not a component of military 

specification (MIL-SPEC) aqueous film forming foam (AFFF) and based on its history including distribution limitations that restricted 

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

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

Analyteb 

Residential

(Soil)

(μg/kg)a 

0-2 feet bgs

Industrial/ Commercial 

Composite Worker

(Soil)

(μg/kg)a 

2-15 feet bgs

Tap Water

(Groundwater)

(ng/L)a

PFOA 19 250 6

PFOS 13 160 4 

PFBS 1,900 25,000 601 

PFHxS 130 1,600 39

PFNA 19 250 6

Notes:

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

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

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

b.) Of the six PFAS compounds presented in the 6 July 2022 OSD memorandum, HFPO-DA (commonly referred to as GenX) was not 

included as an analyte at the time of this SI. Based on the CSM developed during the PA and revised based on SI findings, the 

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

on its history including distribution limitations that restricted use of GenX, it is generally not a component of other products the military 

used. In addition, it is unlikely that GenX would be an individual chemical of concern in the absence of other PFAS. 

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

AOI Potential 

Release Area

Soil –

Source Area

Groundwater –

Source Area Future Action

1 Eastern 

Release Areas Proceed to RI 

2 Western FTAs Proceed to RI 

3 HEMTT 

Storage 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
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1. Introduction

1.1 Project Authorization

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

Assessments (PAs) and Site Inspections (SIs) on the current or potential historical use of perand 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 Tulsa Army Aviation Support Facility (AASF) #2 in Tulsa, Oklahoma. Tulsa AASF #2 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 Tulsa AASF #2 (AECOM Technical Services, Inc. [AECOM], 2020) that

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

stored, disposed, or released historically. The objective of the SI is to identify whether there has 

been a release to the environment from the AOIs identified in the PA and determine whether 

further investigation is warranted, a removal action is required to address immediate threats, or 

no further action is required based on screening levels (SLs) for the relevant compounds.

1 Of the six PFAS compounds presented in the 6 July 2022 OSD memorandum, HFPO-DA (commonly referred to as GenX) was not 

included as an analyte at the time of this SI. Based on the conceptual site model (CSM) developed during the PA and revised based 

on SI findings, the presence of HFPO-DA is not anticipated at the facility because HFPO-DA is generally not a component of military 

specification (MIL-SPEC) aqueous film forming foam (AFFF) and based on its history including distribution limitations that restricted 

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

individual chemical of concern in the absence of other PFAS.
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2. Facility Background

2.1 Facility Location and Description

Tulsa AASF #2 is located at 4220 North Mingo County Expressway, Tulsa, Tulsa County, 

Oklahoma, approximately 9 miles northeast of downtown Tulsa. Tulsa AASF #2 encompasses 

approximately 47 acres of land situated at the junction of US Highway 169 and Oklahoma 

Highway 266. The facility is northeast of Tulsa International Airport, one mile east of the Tulsa 

Air National Guard Base (ANGB), across Mingo Creek (Figure 2-1). Tulsa AASF #2 was built in 

1987, and the Oklahoma ARNG (OKARNG) moved into the facility in 1989. Prior to construction, 

the land was previously agricultural or undeveloped land. 

The mission of AASF #2 is to support aviation equipment and machinery and maintain properly 

trained and equipped units ready for mobilization. The AASF includes a storage hangar, 

maintenance hangar, flight ramp and helicopter autorotation lane, heavy expanded mobility 

tactical truck (HEMTT) storage area, an armory, and support facilities (AECOM, 2020). The 

facility is entirely developed, with paved surfaces covering the majority of the AASF #2 footprint; 

however, some grassy areas surround the buildings and airfield. 

2.2 Facility Environmental Setting

AASF #2 is within the geomorphic province of Claremore Cuesta Plains, which is characterized 

by westward dipping Pennsylvanian-aged sandstones and limestones that form cuestas 

between broad shale plains (Tyrl et al., 2007). The topography at the facility is relatively flat, 

sloping gently to the west towards Mingo Creek, with surface elevations ranging from about 600 

to 610 feet above mean sea level (amsl). Mingo Creek sits roughly 20 to 30 feet lower in 

elevation than AASF #2 and gentle hills rises to the east (Figure 2-2). 

The area surrounding AASF #2 is primarily commercial and industrial use, with large areas of 

undeveloped land abutting those properties. Several large stone quarries, one of which has 

been converted to use as a landfill, are located to the east of the facility. The Tulsa ANGB and

Tulsa International Airport, and commercial/industrial properties associated with the airport,

occupy much of the nearest developed land located 1-mile west of AASF #2. The nearest 

residential properties are just under 1 mile southeast of the facility.

2.2.1 Geology

The geology in the vicinity of AASF #2 is characterized by Pennsylvanian-aged rock, which dips 

to the west, overlain by Quaternary-aged alluvial deposits within the valleys and floodplains 

(Miller and Stanley, 2006; Tyrl et al., 2007). Thin alluvial deposits are present near the facility 

along Mingo Creek; however, the Oologah Formation is the surficial unit present at AASF #2 

and is the predominant surficial unit in the region east of Mingo Creek (Miller and Stanley, 

2006). The Oologah Formation is a Pennsylvanian-aged grayish limestone, with intervals of 

sandstone or fossiliferous shale ranging up to 110 feet-thick (Miller and Stanley, 2006). As the 

surficial unit beneath the facility, the Oologah Formation is shallow, within 5 to 10 feet of the 

ground surface. The unconsolidated material present at the ground surface on AASF #2 is made 

up of mostly fill, brought onsite during construction of the facility, as noted by AASF personnel, 

or the uppermost weathered section of the Oologah. 

The Labette Formation underlies the Oologah Formation and is composed of shale and thin 

laminations of sandstone and limestone. The thickness of the Labette Formation in the Tulsa 

region ranges from 220 to 260 feet thick (Miller and Stanley, 2006). The Labette Formation is 

buried beneath the entire thickness of the Oologah at AASF #2, but daylights on the faces of the 
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bluffs along Bird Creek and the Verdigris River, approximately 3 to 4 miles up-dip from the 

facility. The Fort Scott and Senora Formations, and older Pennsylvanian units, underlie the 

Labette (Miller and Stanley, 2006). Geologic units present at AASF #2 and the surrounding 

region are displayed on Figure 2-3. 

Direct push borings advanced during the SI generally ranged in depth from 8 to 17 feet below 

ground surface (bgs), with the exception of TUL-MW002, which was advanced to a depth of 70

feet bgs. The dominant lithology of the shallow borings consisted of clay and silt. Lean clay and 

silt were encountered from the surface to depths ranging between 6 to 15 feet bgs. Fat clay was 

encountered in two borings, AOI02-01 and TUL-MW003, just above the contact with the 

limestone bedrock. Bedrock was encountered in all borings, at depths between 7 to 15 feet bgs. 

Bedrock logged at TUL-MW002 consisted of well-cemented, hard, and fossiliferous limestone 

from 10 feet bgs to a depth of approximately 47 feet bgs, followed by shale/wackestone and a 

thin interbedded sandstone to a depth of 54 feet bgs. Well-cemented, hard, and fossiliferous 

limestone was observed from 54 to 58 feet bgs, followed by poorly cemented wackestone from 

58 to 60 feet bgs, and then the same well-cemented limestone to the terminal depth of the 

boring at 70 feet bgs. The shallow clayey and silty soils appear consistent with the understood 

presence of fill brought in to grade the facility for construction. The deeper unconsolidated 

material, particularly the clays, are more representative of weathered limestone. The underlying 

fossiliferous limestone with intervals of sandstone, wackestone, and shale is characteristic the 

Pennsylvanian-aged Oologah Formation known to be present beneath AASF #2. The finegrained soils and well-cemented bedrock encountered in the subsurface below the facility may 

limit the transmissivity of PFAS into the deeper subsurface. Boring logs are presented in 

Appendix E. 

Samples for grain size analyses were collected at three locations; AOI01-01, TUL-MW002, and 

AOI01-01, and analyzed via American Society for Testing and Materials (ASTM) Method D-422. 

The samples were collected between the surface and 6 feet bgs, which is the interval most likely 

to contain fill material. The results indicate that the soil samples are comprised primarily of silt 

(58.43 percent [%] to 72.47%), clay (9.90% to 18.05%), and fine sand (6.27% to 18.80%). Grain 

size results are presented in Appendix F. 

2.2.2 Hydrogeology

There is no principal aquifer in the Tulsa area (Johnson, 1983). While groundwater exists in the 

Pennsylvanian rocks found at the facility, it is not ideal for groundwater resources, with most 

wells yielding an estimated rate of 0.5 gallons per minute. The Oologah Formation, which is 

stratigraphically the uppermost unit at the facility, yields small quantities of fair to poor quality 

water (Marcher and Bingham, 1971). 

Subsurface investigative work completed at the C&D landfill, located approximately 1 mile east 

of the facility, indicated groundwater depths vary but are typically at the contact of the Oologah 

and Labette formations or the first 10 feet of the Labette Formation. The boring logs of this work 

indicate the contact between limestone and shale occurs around 532 to 565 feet amsl (E&E 

Engineering and Associates, LLC, 2018). An SI completed in 2018 at the adjacent Tulsa ANGB, 

located approximately 1 mile west of the facility, reported groundwater levels in soil borings and 

monitoring wells that ranged from 4.78 to 25 feet bgs, within the alluvial deposits present west of 

Mingo Creek (Leidos, 2018). Based on the findings from these previous nearby investigations 

and the elevation and flow patterns of nearby surface water features, the inferred groundwater 

flow direction at the facility is northwest.

Depths to groundwater measured in April 2021 during the SI ranged from 1.24 to 11.18 feet bgs; 

however, groundwater was not observed in three of the seven borings advanced, including TULMW002, which was advanced deep into the bedrock. No groundwater was observed in TUL-
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MW002 above bedrock; therefore, drilling proceeded incrementally with the objective of 

identifying a transmissive zone within the bedrock where a monitoring well could be installed. 

Several facies changes were observed within the predominately well-cemented limestone 

boring, but no groundwater was encountered at the anticipated depth between 20 to 40 feet 

bgs, or down to the terminal depth at 70 feet bgs. 

While mobilized in the field, available geologic and hydrogeologic information for the area was 

reevaluated by the project team along with real-time SI findings. As noted previously, the 

Oologah Formation is known to produce little to no groundwater. Additional sources, including 

the C&D landfill investigation, suggested that the first available groundwater would not likely be 

encountered until the underlying shale Labette Formation (E&E Engineering and Associates, 

LLC, 2018). Boring log data from the C&D Landfill investigation indicated the elevation of the top 

of the Labette Formation was projected west toward AASF #2. The data suggested the Labette 

Formation would be encountered at the facility at an elevation between 482 to 498 feet amsl

(110 to 130 feet bgs), approximately 40 to 50 feet below the terminal depth of TUL-MW002. As 

discussed later in Section 5.8, drilling further into bedrock in order to encounter sufficient 

groundwater production (110 to 130 feet bgs) would not provide relevant data that are

representative of impacts due to on-facility conditions. Therefore, deeper bedrock drilling was 

not pursued. 

Groundwater elevations in the shallow borings that produced groundwater were calculated 

using depth to groundwater measurements and surveyed well casing elevations. Groundwater 

elevations were generally higher in the southern portion of the facility and lower to the northnorthwest. As a result, the SI findings show an overall northwesterly groundwater flow direction 

(Figure 2-4). Groundwater availability was limited during sampling, and groundwater depths 

were generally observed to be approximately 1 to 2 feet above the bedrock and/or fat clay 

layers encountered within the soil borings. This observation suggests that the shallow 

groundwater flow at the facility is localized and may depend on the grade of the bedrock surface 

or less permeable clay units rather than regionally influenced. The availability of groundwater 

appeared to correlate to where the unconsolidated material was less compacted and had higher 

silt content that allowed some degree of infiltration for shallow groundwater production. In less 

permeable areas, surface water disposition is likely dominated by runoff rather than infiltration.

Within a 2.5-mile radius of the facility, there are three domestic wells whose total depths range 

from 21 to 197 feet bgs. Additionally, there are numerous monitoring wells at the landfills east of 

the facility and Tulsa ANBG to the west. Most of these monitoring wells have total depths 

ranging from 10 to 60 feet bgs (Oklahoma Water Resource Board, 2020). Groundwater features 

surrounding the facility are shown in Figure 2-3. The facility’s drinking water is supplied by the 

City of Tulsa, which is sourced from surface water as described in Section 2.2.3 below.

2.2.3 Hydrology 

Surface water near AASF #2 includes Mingo Creek, located immediately to the west at an 

elevation approximately 20 to 30 feet below the ground surface elevation at the facility. Mingo 

Creek flows northward into Bird Creek, which is a tributary of the Verdigris River. The inferred 

surface water flow direction at the facility is northwest, eventually draining into Mingo Creek. A 

drainpipe leading to Mingo Creek was observed along the western facility boundary, 

approximately 300 feet west of AOI 1. Surface water features surrounding the facility are shown 

in Figure 2-5. 

The facility’s drinking water is supplied by the City of Tulsa, which acquires its water from Lake 

Spavinaw, Lake Eucha, and Oologah Lake. Lakes Spavinaw and Eucha are located 

approximately 46 and 52 miles east of the facility, respectively; Oologah Lake is about 7.5 miles 

northeast of the facility, on the Verdigris River upstream from its confluence from Bird Creek.
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2.2.4 Climate 

Climate in eastern Oklahoma is classified as humid subtropical (Oklahoma Climatological 

Survey, 2011). The average temperature of Tulsa is 60.7 degrees Fahrenheit (°F). Seasonally, 

temperatures vary from a summer average monthly high of 93 °F to a winter average monthly 

low of 28 °F. Average precipitation in rain Tulsa is 40.91 inches, and average snowfall is 10 

inches (World Climate, 2022). 

2.2.5 Current and Future Land Use

Tulsa AASF #2 encompasses approximately 47 acres of land in northeast Oklahoma, 

approximately 9 miles northeast of downtown Tulsa. The facility is bounded to the west by 

Mingo Creek and wooded land, to the east and south by commercial and industrial facilities, and 

to the north by undeveloped land. The facility currently includes a storage hangar, maintenance 

hangar, flight ramp and helicopter autorotation lane, HEMTT storage area, an armory, and 

support facilities. The mission of the facility is to support aviation equipment and machinery and 

maintain properly trained and equipped units ready for mobilization. Reasonably anticipated 

future land use is not expected to change from the current land use. 

2.2.6 Sensitive Habitat and Threatened/ Endangered Species 

The following birds, fish, insects, mammals, and reptiles are federally endangered, threatened, 

proposed, and/ or are listed as candidate species in Tulsa County, Oklahoma (US Fish and 

Wildlife Service [USFWS], 2022). 

• Birds: Red knot, Calidris canutus rufa (threatened); Piping Plover, Charadrius melodus

(threatened)

• Fish: Peppered chub, Macrhybopsis tetranema (endangered)

• Insects: Monarch butterfly, Danaus plexippus (candidate); American burying beetle,

Nicrophorus americanus (threatened)

• Mammals: Tricolored bat, Perimyotis subflavus (under review); Little brown bat, Myotis

lucifugus (under review); Northern long-eared bat, Myotis septentrionalis (threatened)

• Reptiles: Alligator snapping turtle, Macrochelys temminckii (proposed threatened)

2.3 History of PFAS Use

Nine potential release areas were identified at the Tulsa AASF #2 during the PA where AFFF 

may have been used or released historically: Tri-Max Training Area 1, Storage Hangar, 

Maintenance Hangar, Wash Rack, Evaporator, Building 100, Tri-Max Training Area 2, Tri-Max 

Training Area 3, and HEMTT Storage (AECOM, 2020). 

Tulsa AASF #2 includes three fire training areas (FTAs) (Tri-Max Training Areas 1 to 3) where 

Tri-MaxTM extinguishers were used for fire training activities from as early as the 1990s up until 

the early 2000s. Additionally, Tulsa AASF #2 includes two hangars, the Storage Hangar and 

Maintenance Hangar. In 2014, a fire suppression system was installed in the hangars. The fire 

suppression system conveys Buckeye Hi-Ex foam to three overhead sprayers in the Storage 

Hangar and two overhead sprayers in the Maintenance Hangar. The system was tested twice in 

2014 after installation and resulted in PFAS draining from the Storage and Maintenance 

Hangars via the trench drain. In August 2014, the fire suppression system was accidentally 

triggered, resulting in a release of Buckeye Hi-Ex foam out of the buildings onto the ramp and 

grassy areas. 
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Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 2-5

The Wash Rack was used to wash the Buckeye Hi-Ex foam off the helicopters after the 

accidental fire suppression release event. The Wash Rack effluent drains to an oil-water 

separator (OWS) and is then conveyed to a holding tank. Water in the holding tank is reused by 

the facility to wash aircraft. The excess water is burned off at the Evaporator. AFFF storage was 

noted at Building 100 and the HEMTT Storage. 

The potential release areas were grouped into three AOIs based on proximity to one another 

and presumed groundwater flow. A description of each AOI is presented in Section 3. 
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Figure 2-2

Facility Topography

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Figure 2-5

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AECOM 2-11
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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, nine potential release areas were 

identified at Tulsa AASF #2 and grouped into three AOIs (AECOM, 2020). The potential release 

areas are shown on Figure 3-1. 

3.1 AOI 1 Eastern Release Areas

AOI 1 consists of six potential release areas, as described below. Releases at AOI 1 have 

occurred on both paved areas and grassy surfaces. Some releases may have occurred directly 

onto surface soil but may also have infiltrated to the subsurface soil via cracks in pavement or 

joints between areas that are paved with different materials. 

3.1.1 Tri-Max Training Area 1

Tri-Max Training Area 1 is located west of the Storage Hangar. Between the 1990s and the early 

2000s, Tri-MaxTM extinguishers were used for fire training activities at these locations. One 

training activity occurred at this location and involved the use of one extinguisher. No 

information was provided regarding the dates of the training events. The Tri-MaxTM 

extinguishers were subsequently removed from use in the early 2000s.

3.1.2 Storage Hangar

The Storage Hangar is located between the Maintenance Hangar and the Evaporator. The 

Storage Hangar houses two 300-gallon foam tanks, located along the northern wall, and three 

36-gallon manual AFFF tanks that were obtained in 2013 and are located along the north, east,

and south walls. The 300-gallon foam tanks are filled with 2.2% Buckeye Hi-Ex foam. Foam is

replaced by contractors. No information was provided on the disposal of AFFF and Buckeye HiEx after it leaves the facility or when this occurred.

In 2014, a fire suppression system was installed that conveys Buckeye Hi-Ex foam to three 

overhead sprayers in the Storage Hangar and two overhead sprayers in the Maintenance 

Hangar; the system was tested twice after installation. During both tests, plastic was placed

around both the Storage Hangar and the Maintenance Hangar to prevent foam from leaving the 

hangars. The first test failed because not enough foam was produced by the system, and only a 

small area of hangars was filled with foam. No information was provided on the type of foam 

used in the first test. Consequently, 2.2% Buckeye Hi-Ex foam was acquired, and a second test 

was conducted. The second test was successful, and the hangars filled up with 8 or 9 feet of 

foam. Only an estimated 5-10 gallons of Buckeye Hi-Ex foam were released during the second 

test. After both tests, the facility personnel let the foam settle and pushed it down to the trench 

drain, which transports wastewater to an OWS, then to the City of Tulsa sanitary sewer, and, 

eventually, to the Northside Wastewater Treatment Plant (WWTP). 

In August 2014, the fire suppression system was accidentally triggered, and one of the 300-

gallon foam tanks released into the Storage Hangar. Buckeye Hi-Ex foam spilled out through the 

Storage Hangar doors into the Maintenance Hangar and onto the ramp. Videos of the aftermath 

show up to around 4 feet of foam, which spread approximately 300 feet northward on the ramp 

and into the grassy area just north of the Storage Hangar and approximately 350 feet westward 

into the grassy area between the ramp and the runway. Facility personnel allowed the foam to 

settle and evaporate. The helicopters on the ramp that were covered by foam were washed at 

the Wash Rack. It is estimated that 300 gallons of Buckeye Hi-Ex foam were released during the 

accidental triggering of the fire suppression system.
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Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 3-2

3.1.3 Maintenance Hangar

The Maintenance Hangar is located south of the Storage Hangar and north of the Maintenance 

Room. Two 36-gallon AFFF tanks were obtained in 2013 and are stored in the Maintenance 

Hangar, one on the north side of the hangar, and one on the south side. Buckeye Hi-Ex foam 

filled the Maintenance Hangar to 8 or 9 feet during the second testing of the fire suppression 

system. Only an estimated 5-10 gallons of foam were released during the second test. 

Additionally, an unknown amount of Buckeye Hi-Ex foam spilled into the Maintenance Hangar 

during the August 2014 accidental fire suppression system release event. Any releases in the 

Maintenance Hangar would flow to the trench drain, then to the OWS and, eventually, to the 

Northside WWTP via the sanitary sewer.

3.1.4 Wash Rack

The Wash Rack is located 50 feet northwest of the Storage Hangar and west of the Evaporator. 

The Wash Rack was used to wash the Buckeye Hi-Ex foam off the helicopters after the 

accidental fire suppression release event. The Wash Rack effluent drains to an OWS and is 

then conveyed to a holding tank. Water in the holding tank is reused by the facility to wash 

aircraft. The excess water is burned off at the evaporator.

Multiple types of OWS have been used at the facility. The previous OWS system included a 

defoamer that conveyed the wastewater to Mingo Creek and a system that had a filter in the 

Petroleum, Oil, and Lubricant Storage building with an underground plate system. The current 

OWS is a recycle system with an evaporator and was installed in 2010. A valve on the system 

allows water to be discharged to nearby Mingo Creek, but this only occurs after a large rain 

event and once the water has been checked for a sheen. However, prior to 2010, water was 

discharged to the creek more frequently.

3.1.5 Evaporator

The Evaporator is located just north of the Storage Hangar. The Wash Rack effluent drains to an 

OWS and then to a holding tank. Any excess water is burned off at the Water Maze® 

Evaporator, which was installed in 2010. AFFF or Buckeye Hi-Ex foam discharged at the Wash 

Rack could be conveyed to the Evaporator. Solids from the wash water evaporation process are 

removed and disposed of by a contractor on routine basis. No information was available 

regarding the offsite disposal of the solid waste.

3.1.6 Building 100

Building 100 is located east of the ramp and approximately 100 feet northeast of the evaporator. 

Historically, 25 5-gallon buckets of AFFF were stored at this location. The buckets were donated 

to a local fire station at an unknown date. No information was available on the concentration or 

type of AFFF stored in the buckets. No leaks or spills were reported. No AFFF is currently stored 

in Building 100.

3.2 AOI 2 Western FTAs

AOI 2 consists of two potential release areas, as described below. Releases at AOI 2 occurred 

on paved surfaces and may have flowed northwestward, off the pavement, toward Mingo Creek, 

and potentially impacted surface soil. Additionally, AFFF may also have infiltrated subsurface 

soil via cracks in pavement or joints between areas that are paved with different materials
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AECOM 3-3

3.2.1 Tri-Max Training Areas 2 and 3

Tri-Max Training Area 2 and Tri-Max Training Area 3 are located along the ramp and landing 

pad. Between the 1990s and the early 2000s, Tri-MaxTM extinguishers were used for fire training 

activities at these locations. One training activity occurred at each location and involved the use 

of one extinguisher. No information was provided regarding the dates of the training events. The 

Tri-MaxTM extinguishers were subsequently removed from use in the early 2000s.

3.3 AOI 3 HEMTT Storage

AOI 3 consists of one potential release area, as described below. Any AFFF releases would 

have occurred on paved areas and grassy surfaces. AFFF released to the pavement could have 

infiltrated subsurface soil via cracks in pavement or joints between areas that are paved with 

different materials.

3.3.1 HEMTT Storage

HEMTT Storage is a concrete-covered area that is located north of the flight ramp. Tri-MaxTM 

extinguishers were located at the HEMTT Storage from the 1990s to the early 2000s when the 

extinguishers were removed from the facility. No known or recorded leaks or spills occurred at 

AOI 3. 

3.4 Adjacent Sources

Three potential off-facility sources of PFAS located near AASF #2, not under the control of the 

OKARNG, were identified during the PA and are described below. The potential adjacent 

sources are shown on Figure 3-1.

3.4.1 WWTP Sludge Spreading Area

The WTTP Sludge Spreading Area is located to the east, directly across Mingo Valley 

Expressway. The Northside WWTP historically spread sludge at the WWTP Sludge Spreading 

Area. Information on when the sludge spreading practice began is unclear, but development of 

the area began around 2012; therefore, spreading may have ceased prior to 2012.

3.4.2 Tulsa ANGB

The Tulsa ANGB is less than 1 mile to the west of the facility. An SI report dated November 

2018 identified multiple areas where AFFF was discharged. PFOA, PFOS, PFBS, PFHxS, and 

PFNA were detected in the soil and groundwater. In groundwater, PFOA, PFOS, PFBS, PFHxS, 

and PFNA were detected at maximum concentrations of 4,000 J nanograms per liter (ng/L), 

44,000 J ng/L, 7,600 J ng/L, 69,000 ng/L. and 640 J ng/L, respectively (Leidos, 2018).

Groundwater flow at the Tulsa ANGB was reported to be multi-directional, with both northwest 

and east/northeast flow directions (Leidos, 2018). 

3.4.3 Air Force Plant #3

The Air Force Plant #3 is approximately 1.5 miles to the southwest of the facility, near the Tulsa 

International Airport. An August 2018 SI report for the Air Force Plant #3 indicated that PFOA, 

PFOS, PFBS, and PFHxS were detected in soil and groundwater. In groundwater, PFOA, 

PFOS, PFBS, and PFHxS were detected at maximum concentrations of 410 ng/L, 64 ng/L, 580

ng/L, and 11,000 ng/L, respectively (Oneida Total Integrated Enterprises, 2018). Groundwater 
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AECOM 3-4

flow direction at Air Force Plant #3 was reported to the east and southeast (Oneida Total 

Integrated Enterprises, 2018).
Tri-Max

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Training Area 2

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Training Area 3

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Figure 3-1

Areas of Interest

Legend

Area of Interest

Potential Release Area

Facility Boundary

Water Body

River/Stream

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AECOM 4-1

4. Project Data Quality Objectives

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

Assurance Project Plan (QAPP) Addendum (AECOM, 2021), the objective of the SI is to identify 

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

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

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

groundwater and soil for presence or absence of relevant compounds at each of the sampled 

AOIs.

4.1 Problem Statement

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

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

SLs are presented in Section 6.1 of this report. 

4.2 Information Inputs

Primary information inputs included:

• The PA for Tulsa AASF #2 (AECOM, 2020);

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

accordance with the site-specific Uniform Federal Policy (UFP)-QAPP Addendum

(AECOM, 2021); and

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

parameters measured at the time of sampling.

4.3 Study Boundaries

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

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

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

owner(s). The SI scope was bounded vertically by the observed depths of the surficial groundwater 

table and shallow bedrock. Temporal boundaries of the study were limited by seasonal conditions 

present during the Spring 2022 field work.

4.4 Analytical Approach

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

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

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

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

as defined in the SI QAPP Addendum (AECOM, 2021). 

4.5 Data Usability Assessment

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

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

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

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

resulting data have met installation-specific DQOs. Both sampling and analytical activities are 
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AECOM 4-2

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

support the decision-making (DoD, 2019a; DoD, 2019b; USEPA, 2017).

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

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

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

and requirements of the SI QAPP Addendum (AECOM, 2021).
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Army Aviation Support Facility #2, Tulsa, Oklahoma

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, Tulsa Army Aviation Support Facility #2, Tulsa, 

Oklahoma dated October 2020 (AECOM, 2020);

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

Army Aviation Support Facility #2, Tulsa, Oklahoma dated September 2021 (AECOM, 

2021); and

• Final Site Safety and Health Plan, Army Aviation Support Facility, Tulsa, Oklahoma dated 

March 2022 (AECOM, 2022).

The SI field activities were conducted from 4 to 14 April 2022 and consisted of utility clearance, 

sonic drilling, soil sample collection, temporary monitoring well installation, grab groundwater 

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

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

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

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

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

• Twenty-six (26) soil samples from thirteen (13) locations; 

• Four (4) grab groundwater samples from four (4) of six (6) temporary wells; and

• Sixteen (16) 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, and 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 US Army Corps of Engineers (USACE) TPP Process, Engineer Manual (EM) 200-1-2 

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

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

collection plan. The process encourages stakeholder involvement in the SI, beginning with 
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Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 5-2

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

address the AOIs identified in the PA. 

A combined TPP Meeting 1 and 2 was held on 18 August 2021, prior to SI field activities. The 

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

stakeholders for this SI include the ARNG, OKARNG, USACE, and Oklahoma Department of 

Environmental Quality. Stakeholders were provided the opportunity to make comments on the 

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

of the combined TPP Meeting 1 and 2 was memorialized in the SI QAPP Addendum (AECOM, 

2021). 

A TPP Meeting 3 was held on 3 April 2023 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

Both AECOM and their drilling subcontractor, Environmental Works, Inc., contacted Oklahoma

811 (OKIE811) one-call utility clearance contractor prior to mobilization to notify them of intrusive 

work. Because OKIE811 locators do not locate private utilities, such as those belonging to Tulsa 

AASF #2, AECOM contracted Ground Penetrating Radar Systems, LLC. (GPRS) to perform 

utility clearance for private utilities at all boring locations. GPRS performed the utility clearance 

under the oversight of the AECOM field team on 4 April 2022 using industry standard methods 

in addition to ground-penetrating radar. Additionally, the first 5 feet of each boring were precleared 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

Two potable water source samples at Tulsa AASF #2 were sampled on 26 October 2021 to 

assess usability for use prior to the start of field activities. Results of the samples confirmed the

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

the DUA (Appendix A).

Materials that were used within the sampling zone were confirmed as acceptable for use in the 

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

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

QAPP Addendum (AECOM, 2021). Prior to the start of field work each day, a Sampling 

Checklist was completed as an additional layer of control. The checklist served as a daily 

reminder to each field team member regarding the allowable materials within the sampling 

environment.

5.2 Soil Borings and Soil Sampling

Soil samples were collected via rotary sonic (sonic) drilling technology, in accordance with the 

SI QAPP Addendum (AECOM, 2021). At all boring locations, with the exception of AOI02-02, a

Boart LongyearTM LSTM250 MinisonicTM sampling system was used to collect continuous soil 

cores to the target depth. A Geoprobe® 8150LS sonic sampling system replaced the original 

sonic rig towards the end of the SI and was used at AOI02-02 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.
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Army Aviation Support Facility #2, Tulsa, Oklahoma

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 approximately 2 feet above the observed saturated soil or bedrock, and one subsurface 

soil sample at the mid-point between the surface and the saturated soil or bedrock. To 

supplement the drilled boring locations, additional surface soil samples were collected at other 

locations using a hand auger.

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

geologist using the Unified Soil Classification System (USCS). Rock cores, which do not have a 

system similar to USCS, were logged using industry accepted descriptions of rock types and 

characteristics. 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 and in a non-treated field logbook (i.e., composition notebook). Depth 

interval, recovery thickness, PID concentrations, moisture, relative density, color (using a 

Munsell soil color chart), and texture (using the USCS) were recorded. The boring logs are 

provided in Appendix E.

Sonic borings advanced during the SI generally ranged in depth from 8 to 17 feet bgs, with the 

exception of TUL-MW002, which was advanced to a depth of 70 feet bgs. The dominant 

lithology of the borings consisted of clay and silt. Lean clay and silt were encountered from the 

surface to depths ranging between 6 to 15 feet bgs. Fat clay was encountered in two borings, 

AOI02-01 and TUL-MW003, just above the limestone bedrock contact. Bedrock was 

encountered in all borings below the unconsolidated soils. The geologist noted that in the deep 

boring at TUL-MW002, the bedrock consisted of well-cemented, hard, and fossiliferous 

limestone to a depth of approximately 47 feet bgs, followed by shale/wackestone, and a thin 

interbedded sandstone to a depth of 54 feet bgs. Well-cemented, hard, and fossiliferous 

limestone was observed from 54 to 58 feet bgs, followed by poorly cemented wackestone from 

58 to 60 feet bgs, and then the same well-cemented, fossiliferous limestone to the terminal

depth of the boring at 70 feet bgs. The shallow surface clay and silt are likely fill material used to 

grade the facility. The deeper unconsolidated material, particularly the clays, are likely 

weathered limestone. The underlying fossiliferous limestone with intervals of sandstone, 

wackestone, and shale are characteristic of the Pennsylvanian-aged Oologah Formation.

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, 2021).

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

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

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

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

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

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

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

The boreholes were converted to temporary wells, which were subsequently abandoned in 

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

of sampling activities. Borings were installed in grass areas to avoid disturbing concrete or 

asphalt surfaces.
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Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 5-4

5.3 Temporary Well Installation and Groundwater Grab Sampling

Temporary wells were installed using Boart LongyearTM LSTM250 MinisonicTM and Geoprobe®

8150LS sonic drill rigs. Once the borehole was advanced to the desired depth, a temporary well 

was constructed of a 10-foot section of 1-inch Schedule 40 poly-vinyl chloride (PVC) screen with 

sufficient casing to reach ground surface. The temporary wells were installed within the open 

borehole without the use of a sand filter pack or well seal. New PVC pipe and screen were used 

to avoid cross contamination between locations. The screen intervals for the temporary wells 

are provided in Table 5-2.

The temporary wells were left in place after installation to allow for groundwater infiltration

before collection of groundwater samples. After the recharge period, groundwater samples were 

collected using a peristaltic pump with PFAS-free HDPE tubing. The temporary wells were 

purged at a rate determined in the field to reduce turbidity and draw down prior to sampling. 

Water quality parameters (e.g., temperature, specific conductance, pH, dissolved oxygen, and 

oxidation-reduction potential were measured using a water quality meter and recorded on the 

field sampling form (Appendix B2) before each grab sample was collected. Each sample was 

collected into laboratory-supplied PFAS-free HDPE bottles and labeled using a PFAS-free 

marker or pen. 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. Light

foaming was noted in the groundwater subsample collected from AOI01-01. Samples were 

packaged on ice and transported via FedEx under standard CoC procedures to the laboratory 

and analyzed by LC/MS/MS compliant with QSM 5.3 Table B-15 in accordance with the SI 

QAPP Addendum (AECOM, 2021). As described in detail in Section 5.8, several locations did 

not produce groundwater during the SI and, as a result, were unable to be sampled.

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.

Temporary wells were abandoned in accordance with the SI QAPP Addendum (AECOM, 2021) 

by removing the PVC and backfilling the hole with bentonite chips. Temporary wells were 

installed in grass areas to avoid disturbing concrete or asphalt.

5.4 Synoptic Water Level Measurements

A synoptic groundwater gauging event was performed on 13 April 2022. Groundwater elevations

were measured in the six new temporary monitoring wells. Two wells were observed to be dry 

during gauging. Groundwater was measured between 1.24 to 11.18 feet bgs. A groundwater 

flow contour map is provided in Figure 2-4. Groundwater elevation data are provided in Table 

5-2.

5.5 Surveying

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

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

Survey data from the newly installed wells on the facility were collected on 13 April 2022 in the 

applicable Universal Transverse Mercator zone projection with World Geodetic System 84 

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

are provided in Appendix B4.
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Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 5-5

5.6 Investigation-Derived Waste

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

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

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

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

Solid IDW (i.e., soil and rock cuttings) was generated during the SI activities from the seven

boring locations. No soil IDW was generated at the surface soil sample locations. Solid IDW 

were containerized into four labeled 55-gallon Department of Transportation (DOT)-approved 

steel drums and stored in the northeast portion of the facility in the Conex box storage area, 

pending laboratory analysis. IDW. The soil IDW was not sampled and assumes the PFAS 

characteristics of the associated soil samples collected from that source location. ARNG will 

coordinate the transportation and disposal of the solid IDW in accordance with the Army 

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

Liquid IDW generated during SI activities (i.e., purge water and decontamination fluids) were 

containerized in a labeled 55-gallon DOT-approved steel drums. Due to the minimal amount of 

IDW generated, liquid IDW from all locations was consolidated into one drum. Additionally, liquid 

slurry IDW (i.e., drilling fluids and soil) were containerized in a labeled 55-gallon drum. The 

drums were stored next to the solid IDW drums. The liquid and liquid slurry IDW were not 

sampled and will assume the characteristics of the associated soil samples. Based on 

laboratory results, containerized liquid IDW will be managed and disposed by ARNG (either by 

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

accordance with SOP No. 042A for Treating Liquid Investigation-Derived Material (Purge water, 

drilling water, and decontamination fluids) (EA Engineering, Science, and Technology, Inc., 

2021). ARNG will further coordinate to ensure proper disposal in accordance with state 

requirements and the Army Guidance for Addressing Releases of PFAS, Q18 (DA, 2018).

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

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

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

Forms (Appendix B3): 

• At the first borehole drilled (TUL-MW002), clay with little moisture was encountered from 

the surface to bedrock interface at 10 feet bgs. Bedrock cores showed a well-cemented, 

hard, fossiliferous limestone consistent with the Oologah Formation to 47 feet bgs, where 

a 3- to 4-foot-thick section of interbedded wackestone and sandstone was encountered. 

The hole was left open overnight at 55 feet bgs, and no groundwater infiltration was 

observed the following morning. The boring was then drilled to 70 feet bgs and 

encountered wackestone within the limestone from 58 feet bgs to 60 feet bgs. The 70-footdeep boring was pumped dry to remove all drilling water introduced during sonic coring
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Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 5-6

and left overnight. Groundwater infiltration was not observed the following day. Geologic 

information for the area was reevaluated along with real-time SI findings. The information 

suggested that groundwater was not available within the Oologah at the AASF, and that 

the first available groundwater would likely not be encountered until at or within the 

underlying shale Labette Formation, expected at a depth of around 110 to 130 feet bgs. 

The team concluded that groundwater at these depths would not be representative of onfacility conditions for the following reasons: 1) the unconsolidated clay and thick section of 

competent limestone make surface infiltration to this groundwater unlikely, and 2) the 

westward dipping bedrock suggests that groundwater recharge at this depth comes from 

areas well east of the facility, the nearest recharge likely occurring 1.5 miles east of AASF 

#2 in a stone quarry now operating as a landfill. 

No monitoring well was installed at TUL-MW002, and the borehole was sealed with grout. 

The project team decided to proceed by drilling at the temporary well locations to 

determine if shallow groundwater was available above the bedrock elsewhere at the 

facility. Each location was drilled without the use of water to the bedrock contact and a 

temporary well casing installed. Groundwater was observed in wells AOI02-01 and AOI01-

02 within several hours after installation. Based on these findings, similar temporary wells 

were installed at all remaining proposed well locations: TUL-MW001, TUL-MW003, and 

AOI02-02. Location AOI02-02 was originally a surface soil sample location but was used 

as a substitute well location for TUL-MW002 because of concerns for drill water or grout

intrusion near the original TUL-MW002 location. AOI02-02 is considered comparable 

because it is located at the same release area, approximately 125 feet upgradient from 

TUL-MW002, across the helicopter autorotation lane. 

Six shallow temporary wells were installed instead of the mix of permanent and temporary 

wells. Groundwater samples were collected from four locations: AOI01-01, AOI02-02, 

TUL-MW001, and AOI02-01. Groundwater samples were not collected where it was not 

observed; at AOI02-02 and background location TUL-MW003. These actions are

documented in a Field Change Request form provided in Appendix B3.

• Borings advanced during the SI found predominantly stiff, well-compacted clayey soils with 

varying amounts of silt. These observations are consistent with the clay top-fill and grading 

activities noted by facility personnel to have been conducted during the construction of 

AASF #2. Groundwater availability was intermittent within this shallow unconsolidated 

zone above bedrock. As stated in FCR001, locations that were less compacted and had 

higher silt content likely allow a greater degree of infiltration for shallow groundwater 

production. In less permeable areas, surface water disposition is likely dominated by 

runoff. PFAS-containing materials released directly to the ground surface is likely to flow 

overland rather than infiltrate. Thus, PFAS may be more likely encountered in surface 

materials than in groundwater. Where infiltration is significantly limited at AASF #2, 

materials released directly to the ground surface likely flow overland and could 

concentrate in low-lying areas or flow off facility. On impervious surfaces, such as the flight 

ramp, runoff not captured by surface drains flows off hard surfaces to low-lying grassy 

areas. Ponded water on the facility then either slowly infiltrates or, more likely, eventually 

evaporates. 

To adapt to the evolved understanding of the conceptual site model and evaluate the 

possibility of PFAS concentrating in these low-lying areas within AASF #2, several 

surface soil samples were added to the SI sample inventory. The added samples were 

collected from the lowest parts of the grassy median located between the AASF 

helicopter autorotation lane and the flight ramp. Two of the additional samples, identified

as AOI01-05 and AOI01-06, were sampled in the northern half of the median, west of the 

potential release areas making up AOI 1. The third sample added, AOI02-03, was 
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Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 5-7

collected in the low point of the swale near the two Tri-Max training areas making up AOI

2. These actions were documented in a Field Change Request form provided in 

Appendix B3. These actions were documented in a Field Change Request form provided 

in Appendix B3, and the sample locations are shown on Figure 5-1.
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Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 5-8

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Table 5-1

Site Inspection Samples by Medium

Site Inspection Report, Tulsa AASF, Oklahoma

Sample Identification

Sample

Collection 

Date

Sample Depth 

(feet bgs)

LC/MS/MS QSM 5.3 Table B-15TOC(USEPA Method 9060A)pH (USEPA Method 9045D)Grain Size (ASTM D422)

Comments

AOI01-01-SB-00-02 4/5/2022 0-2 x

AOI01-01-SB-05-06 4/8/2022 5-6 x x

AOI01-01-SB-8.5-9.5 4/8/2022 8.5-9.5 x

AOI01-02-SB-00-02 4/5/2022 0-2 x

AOI01-02-SB-00-02-D 4/5/2022 0-2 x Duplicate

AOI01-02-SB-07-08 4/8/2022 7-8 x

AOI01-02-SB-07-08-MS 4/8/2022 7-8 x MS/MSD

AOI01-02-SB-07-08-MSD 4/8/2022 7-8 x MS/MSD

AOI01-02-SB-14-15 4/8/2022 14-15 x

AOI01-03-SB-00-02 4/5/2022 0-2 x x x

AOI01-03-SB-00-02-D 4/5/2022 0-2 x x Duplicate

AOI01-04-SB-00-01 4/5/2022 0-1 x

AOI01-05-SB-00-02 4/9/2022 0-2 x

AOI01-06-SB-00-02 4/9/2022 0-2 x

AOI02-01-SB-00-02 4/5/2022 0-2 x x x

AOI02-01-SB-00-02-MS 4/5/2022 0-2 x x MS/MSD

AOI02-01-SB-00-02-MSD 4/5/2022 0-2 x x MS/MSD

AOI02-01-SB-03-04 4/8/2022 3-4 x

AOI02-01-SB-05-06 4/8/2022 5-6 x

AOI02-02-SB-00-02 4/4/2022 0-2 x

AOI02-02-SB-05-06 4/13/2022 5-6 x

AOI02-03-SB-00-02 4/9/2022 0-2 x

AOI03-01-SB-00-02 4/5/2022 0-2 x x x x

AOI03-01-SB-00-02-D 4/5/2022 0-2 x Duplicate

TUL-MW001-SB-00-02 4/5/2022 0-2 x

TUL-MW001-SB-00-02-D 4/5/2022 0-2 x Duplicate

TUL-MW001-SB-09-10 4/9/2022 9-10 x

TUL-MW001-SB-05-06 4/9/2022 5-6 x

TUL-MW002-SB-00-02 4/4/2022 0-2 x

TUL-MW002-SB-00-02-MS 4/4/2022 0-2 x MS/MSD

TUL-MW002-SB-00-02-MSD 4/4/2022 0-2 x MS/MSD

TUL-MW002-SB-4-5 4/5/2022 4-5 x

TUL-MW002-SB-5-6 4/5/2022 5-6 x

TUL-MW002-SB-9-10 4/5/2022 9-10 x

TUL-MW003-SB-00-02 4/5/2022 0-2 x

TUL-MW003-SB-05-06 4/9/2022 5-6 x

TUL-MW003-SB-8.5-9.5 4/9/2022 8.5-9.5 x

Soil Samples

AECOM 5-9
AOI01-01-GW 4/10/2022 NA x light foam

AOI01-02-GW 4/9/2022 NA x

AOI02-01-GW 4/8/2022 NA x

AOI02-01-GW-D 4/8/2002 NA x Duplicate

AOI02-01-GW-MS 4/8/2022 NA x MS/MSD

AOI02-01-GW-MSD 4/8/2022 NA x MS/MSD

TUL-MW001-GW 4/10/2022 NA x

TUL-FRB-01 4/13/2022 NA x

TUL-ERB-01 4/5/2022 NA x Hand auger

TUL-ERB-02 4/13/2022 NA x Core head

TUL-DECON-01 10/26/2021 NA x

TUL-DECON-02 10/26/2021 NA x

TUL-DECON-03 4/13/2022 NA x

Notes:

AASF = Army Aviation Support Facility MS/MSD = matrix spike/matrix spike duplicate

AOI = Area of Interest pH = potential for hydrogen

bgs = below ground surface SB = soil boring

D = duplicate TOC = total organic carbon

ERB - equipment blank USEPA = United States Environmental Protection Agency

FRB - field reagent blank

MW = monitoring well

Groundwater Samples

Blank Samples

Table 5-1

Site Inspection Samples by Medium

Site Inspection Report, Tulsa AASF, Oklahoma

AECOM 5-10
Table 5-2

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

Site Inspection Report, Tulsa AASF #2, Tulsa, Oklahoma

Area of 

Interest

Boring 

Location

Soil Boring 

Depth 

(feet bgs)

Temporary Well 

Screen Interval 

(feet bgs)

Top of Casing 

Elevation 

(feet NAVD88)

Ground Surface 

Elevation 

(feet NAVD88)

Depth to 

Water

(feet btoc)

Dep

W

(fee

AOI01-01 11.5 1.5-11.5 607.63 606.40 12.41 11AOI01-02 17 7-17 612.11 610.68 12.02 10

TUL-MW001 12 2-12 608.86 607.29 9.93 8

AOI02-01 9 0-9 607.72 606.68 2.28 1

AOI02-02 8 0-8 N/A 607.93 Dry D

TUL-MW002 70 N/A N/A 607.80 N/A N

Sitewide TUL-MW003 12 2-12 611.18 609.76 Dry D

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

12

AECOM 
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Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 5-12

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"S

"S

?!

?! ?!

"S

"S

"S

"S

AOI 1

AOI 2

AOI 3

AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI01-03

AOI01-04

AOI02-01

TUL-MW002

AOI02-02

AOI03-01

AOI01-06

AOI01-05

AOI02-03

­ 12420 Milestone Center Drive

Germantown, MD 20876

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

VG

10/10/2022

10/10/2022

PROJECT Site Inspection at Tulsa AASF #2, OK

10/10/2022

1:4,800

PM CM 10/10/2022 Base Map: Source: Esri, Maxar, Earthstar Geographics,

and the GIS User Community

Figure 5-1

Site Inspection Sample Locations

0 200 400 800

Feet

Legend

?! Soil Boring/Temporary Well Location

"S Surface Soil Sample Location

Area of Interest

Facility Boundary

Groundwater Flow Direction

AECOM 5-13
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AECOM 5-14

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Army Aviation Support Facility #2, Tulsa, Oklahoma

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 6-4 present results in soil or groundwater for the 

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

laboratory reports are provided in Appendix G. 

6.1 Screening Levels

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

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

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

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

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

CERCLA. The SLs established in the OSD memorandum apply to the five compounds 

presented on Table 6-1 below.

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

Analyteb

Residential

(Soil)

(μg/kg)a 

0-2 feet bgs

Industrial/ 

Commercial 

Composite 

Worker

(Soil)

(μg/kg)a 

2-15 feet bgs

Tap Water

(Groundwater)

(ng/L)a

PFOA 19 250 6 

PFOS 13 160 4

PFBS 1,900 25,000 601 

PFHxS 130 1,600 39

PFNA 19 250 6 

Notes:

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

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

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

b.) Of the six PFAS compounds presented in the 6 July 2022 OSD memorandum, HFPO-DA (commonly referred to as GenX) was not 

included as an analyte at the time of this SI. Based on the CSM developed during the PA and revised based on SI findings, the 

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

on its history including distribution limitations that restricted use of GenX, it is generally not a component of other products the military 

used. In addition, it is unlikely that GenX would be an individual chemical of concern in the absence of other PFAS. 

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

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

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

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

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

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

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

Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 6-2

6.2 Soil Physicochemical Analyses

To provide basic soil parameter information, select 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 analysis. 

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: Eastern Release Areas. The soil and groundwater results are summarized on Table 6-2

through Table 6-4. Soil and groundwater results are presented on Figure 6-1 through Figure 6-

7.

6.3.1 AOI 1 Soil Analytical Results

Surface soil was sampled from 0 to 2 feet bgs at boring locations AOI01-01 through AOI01-06, 

TUL-MW001, and TUL-MW003. Soil was also sampled from shallow subsurface soil (5 to 15

feet bgs) from boring locations AOI01-01, AOI01-02, TUL-MW001, and TUL-MW003. Deep 

subsurface samples (> 15 feet bgs) were not collected. Figure 6-1 through Figure 6-5 present 

the ranges of detections in soil. Table 6-2 and Table 6-3 summarize the soil results.

PFOA, PFOS, PFHxS, and PFNA were detected in the surface soil at concentrations below the 

SLs. The maximum detected concentration among the four compounds was PFOS at 12.1 

micrograms per kilogram (μg/kg) at AOI01-02. PFBS was not detected.

PFOS, PFHxS, and PFNA were detected in the shallow subsurface soil at concentrations at 

least two orders of magnitude below the SLs and were detected at fewer locations than in 

surface soil. The maximum detected concentration among the three compounds was PFHxS at 

0.835 J μg/kg at TUL-MW001. PFOA and PFBS were not detected.

6.3.2 AOI 1 Groundwater Analytical Results

Groundwater was sampled from temporary monitoring well AOI01-01, AOI01-02, and TULMW001. Groundwater was not observed at TUL-MW003. Figure 6-6 and Figure 6-7 present 

the ranges of detections in groundwater. Table 6-4 summarizes the groundwater results.

In summary, PFOA, PFOS, and PFHxS were detected in groundwater above their SLs. PFBS 

and PFNA were detected below their SLs. Details are highlighted below. 

• PFOA was detected above the 6 ng/L SL, at concentrations of 34.1 ng/L (AOI01-01) and 

59.9 ng/L (TUL-MW001).

• PFOS was detected above the 4 ng/L SL, at concentrations of 51.6 ng/L (AOI01-01) and 

267 ng/L (TUL-MW001).
Site Inspection Report

Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 6-3

• PFHxS was detected above the 39 ng/L SL, at concentrations of 939 ng/L (AOI01-01)

and 3,100 ng/L (TUL-MW001).

PFBS and PFNA were detected at concentrations below their SLs. The maximum detected 

PFBS and PFNA concentrations were reported as 82.1 ng/L (TUL-MW001) and 2.30 J ng/L 

(AOI01-01), respectively.

6.3.3 AOI 1 Conclusions

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

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

their SLs. Based on the exceedances of the SLs in groundwater, further evaluation at AOI 1 is 

warranted.

6.4 AOI 2

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

AOI 2: Western FTAs. The results in soil and groundwater are summarized on Table 6-2

through Table 6-4. Soil and groundwater results are presented on Figure 6-1 through Figure 6-

7.

6.4.1 AOI 2 Soil Analytical Results

Surface soil was sampled from 0 to 2 feet bgs at boring locations AOI02-01 through AOI02-03 

and TUL-MW002. Soil was also sampled from shallow subsurface soil (3 to 10 feet bgs) from 

boring locations AOI02-01, AOI02-02, and TUL-MW002. Deep subsurface samples were not 

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

through Table 6-3 summarize the soil results.

PFOA, PFOS, PFHxS, and PFNA were detected in the surface soil, at concentrations below 

their SLs. The maximum detected concentration among the four compounds was PFOS, at 4.62 

J+ μg/kg at AOI02-01. PFBS was not detected.

In the shallow subsurface soil, PFOS and PFHxS were detected at concentrations at least three 

orders of magnitude below their SLs. The maximum detected concentration among the two

compounds was PFOS, at 0.149 J μg/kg at AOI02-01. PFOA, PFBS, and PFNA were not 

detected.

6.4.2 AOI 2 Groundwater Analytical Results

Groundwater was sampled from temporary monitoring well AOI02-01. Groundwater was not 

observed at AOI02-02 or TUL-MW002. Figure 6-6 and Figure 6-7 present the ranges of 

detections in groundwater. Table 6-4 summarizes the groundwater results. 

PFOA, PFOS, and PFHxS exceeded their SLs at AOI02-01, at concentrations of 8.79 ng/L, 141 

J ng/L, and 382 ng/L, respectively. PFBS was detected at a concentration of 10.5 ng/L, below 

the SL. PFNA was not detected.

6.4.3 AOI 2 Conclusions

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

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

their SLs. Based on the exceedances of the SLs in groundwater, further evaluation at AOI 2 is 

warranted. 
Site Inspection Report

Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 6-4

6.5 AOI 3 

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

Storage. The results in soil are presented in Table 6-2. Soil results are presented on Figure 6-1

through Figure 6-5. Shallow and deep subsurface soil and groundwater were not sampled at 

AOI 3, consistent with the SI QAPP Addendum, based on the understanding that no known 

releases occurred at this location (AECOM, 2021). 

6.5.1 AOI 3 Soil Analytical Results

Surface soil was sampled from 0 to 2 feet bgs at boring location AOI03-01. Shallow and deep 

subsurface soil samples were not collected at AOI 3. Figure 6-1 through Figure 6-5 present the 

ranges of detections in soil. Table 6-2 summarizes the soil results. 

PFOA, PFOS, PFBS, PFHxS, and PFNA were detected in the surface soil, at concentrations 

below their SLs. The maximum detected concentration among the four compounds was PFOS, 

at 2.27 μg/kg at AOI03-01.

6.5.2 AOI 3 Conclusions

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

surface soil, at concentrations below their SLs. Subsurface soil and groundwater were not 

sampled at AOI 3. Based on the findings below the SLs in soil, further evaluation at AOI 3 is not 

warranted.
Table 6-2

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

Site Inspection Report, Tulsa AASF

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual R

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

PFHxS 130 0.196 J 1.67 1.55 0.038 J 0.121 J 0.554 J 0.736 J 0.611 J 0.95PFNA 19 0.049 J 0.375 J 0.475 J 0.021 J 0.115 J 0.055 J 0.267 J 0.033 J 0.064 PFOA 19 0.120 J 0.549 J 0.685 J ND U ND U 0.137 J 0.381 J 0.098 J 0.18PFOS 13 0.783 J 11.9 12.1 0.189 J 0.969 J 3.40 11.2 1.57 3.48 

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

J = Estimated concentration AASF Army Aviation Support FacilityJ+ = Estimated concentration, biased high AOI Area of InterestU = The analyte was not detected at a level greater than or equal to the adjusted DL D duplicate

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. DL detection limit

ft feet

Notes HQ hazard quotientND = Analyte not detected above the LOD. LOD values are presented in Appendix F. ID identification

LCMSMS liquid chromatography with tandem LOD limit of detectionND analyte not detected above the LODOSD Office of the Secretary of DefenseQSM Quality Systems ManualQual interpreted qualifierSB soil boringTUL TulsaUSEPA United States Environmental Protecμg/kg micrograms per kilogram

a. Assistant Secretary of Defense, July 2022. Risk Based Screening Levels Calculated for PFOA, PFOS, PFBS, PFHxS, and PFNA in Groundwater or Soil using USEPA’s Regional Screening Level Calculator. HQ=0.1, May 2022. Soil screening levels based on residential scenario for incidental ingestion of contaminated soil.

AOI01

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

TUL-MW001-SB-00-02

04/05/2022

0-2 ft

TUL-

AOI01-05-SB-00-02

04/09/2022

0-2 ft

AOI01-06-SB-00-02

04/09/2022

0-2 ft

AOI01-03-SB-00-02

04/05/2022

0-2 ft

AOI01-04-SB-00-01

04/05/2022

0-1 ft

AOI01-02-SB-00-02

04/05/2022

0-2 ft

AOI01-02-SB-00-02-D

04/05/2022

0-2 ft

Area of Interest

Sample ID

Sample Date

Depth

AOI01-01-SB-00-02

04/05/2022

0-2 ft

AECOM 
Table 6-2

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

Site Inspection Report, Tulsa AASF

Analyte OSD Screening 

Level a

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

PFBS 1900 ND U ND U ND U ND U 0.026 J ND UJPFHxS 130 0.284 J ND U 0.481 J ND U 0.382 J 0.234 JPFNA 19 0.066 J 0.071 J 0.045 J ND U 0.046 J 0.042 JPFOA 19 0.219 J 0.115 J 0.093 J ND U 0.171 J 0.141 JPFOS 13 4.62 J+ 0.249 J 1.23 0.073 J 2.27 1.80

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

J = Estimated concentration AASF Army Aviation Support FacilityJ+ = Estimated concentration, biased high AOI Area of InterestU = The analyte was not detected at a level greater than or equal to the adjusted DL D duplicate

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. DL detection limit

ft feet

Notes HQ hazard quotientND = Analyte not detected above the LOD. LOD values are presented in Appendix F. ID identification

LCMSMS liquid chromatography with tandem LOD limit of detectionND analyte not detected above the LODOSD Office of the Secretary of DefenseQSM Quality Systems ManualQual interpreted qualifierSB soil boringTUL TulsaUSEPA United States Environmental Protecμg/kg micrograms per kilogram

a. Assistant Secretary of Defense, July 2022. Risk Based Screening Levels Calculated for PFOA, PFOS, PFBS, PFHxS, and PFNA in Groundwater or Soil using USEPA’s Regional Screening Level Calculator. HQ=0.1, May 2022. Soil screening levels based on residential scenario for incidental ingestion of contaminated soil.

AOI02 AOI03

AOI03-01-SB-00-02-D

04/05/2022

0-2 ft

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

TUL-MW002-SB-00-02

04/04/2022

0-2 ft

AOI03-01-SB-00-02

04/05/2022

0-2 ft

AOI02-02-SB-00-02

04/05/2022

0-2 ft

AOI02-03-SB-00-02

04/09/2022

0-2 ft

Area of Interest

Sample ID

Sample Date

Depth

AOI02-01-SB-00-02

04/05/2022

0-2 ft

AECOM 
Table 6-3

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

Site Inspection Report, Tulsa AASF

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Re

PFBS 25000 ND U ND U ND U ND U ND U ND U ND U ND U ND PFHxS 1600 0.032 J 0.083 J 0.103 J 0.065 J 0.835 J 0.406 J 0.642 J 0.072 J 0.087 PFNA 250 ND U ND U ND U ND U ND U 0.029 J ND U ND U ND PFOA 250 ND U ND U ND U ND U ND U ND U ND U ND U ND PFOS 160 ND U ND U ND U ND U 0.191 J 0.136 J 0.541 J ND U 0.149 

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

J = Estimated concentration AASF Army Aviation Support FacilityU = The analyte was not detected at a level greater than or equal to the adjusted DL AOI Area of Interest

D duplicate

Notes DL detection limitND = Analyte not detected above the LOD. LOD values are presented in Appendix F. ft feet

HQ hazard quotientID identificationLCMSMS liquid chromatography with tandem LOD limit of detectionND analyte not detected above the LODOSD Office of the Secretary of DefenseQSM Quality Systems ManualQual interpreted qualifierSB soil boringTUL TulsaUSEPA United States Environmental Protecμg/kg micrograms per kilogram

Area of Interest

Sample ID

Sample Date

Depth

AOI01-01-SB-05-06

04/08/2022

5-6 ft

AOI01-01-SB-8.5-9.5

04/08/2022

8.5-9.5 ft

AOI01-02-SB-07-08

04/08/2022

7-8 ft

TUL-MW003-SB-05-06

04/09/2022

5-6 ft

AOI01-02-SB-14-15

04/08/2022

14-15 ft

TUL-MW001-SB-05-06

04/09/2022

5-6 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 

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

TUL-MW003-SB-8.5-9.5

04/09/2022

8.5-9.5 ft

AOI

TUL-MW001-SB-09-10

04/09/2022

9-10 ft

AECOM 
Table 6-3

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

Site Inspection Report, Tulsa AASF

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual

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

J = Estimated concentration AASF Army Aviation Support FacilityU = The analyte was not detected at a level greater than or equal to the adjusted DL AOI Area of Interest

D duplicate

Notes DL detection limit

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

HQ hazard quotientID identificationLCMSMS liquid chromatography with tandeLOD limit of detectionND analyte not detected above the LOSD Office of the Secretary of DefensQSM Quality Systems ManualQual interpreted qualifierSB soil boringTUL TulsaUSEPA United States Environmental Proμg/kg micrograms per kilogram

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

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.

AOI02

TUL-MW002-SB-05-06

04/05/2022

5-6 ft

TUL-MW002-SB-09-10

04/05/2022

9-10 ft

Area of Interest

Sample ID

Sample Date

Depth

AOI02-02-SB-05-06

04/13/2022

5-6 ft

AECOM 
Table 6-4

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

Site Inspection Report, Tulsa AASF #2

Analyte OSD Screening 

Level a

Result Qual Result Qual Result Qual Result Qual Result Qual

PFBS 601 37.7 0.756 J 82.1 10.5 8.30PFHxS 39 939 11.1 3100 382 283

PFNA 6 2.30 J ND U ND U ND U ND UPFOA 6 34.1 1.03 J 59.9 8.79 6.51PFOS 4 51.6 ND U 267 141 J 98.7 J

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

J = Estimated concentration AASF Army Aviation Support FacilityU = The analyte was not detected at a level greater than or equal to the adjusted DL AOI Area of Interest

D duplicate

Notes DL detection limitND = Analyte not detected above the LOD. LOD values are presented in Appendix F. GW groundwater

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

AOI01-01-GW

04/10/2022

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

a. Assistant Secretary of Defense, July 2022. Risk Based Screening Levels Calculated for PFOA, PFOS, PFBS, PFHxS, and PFNA in Groundwater or Soil using USEPA’s Regional Screening Level Calculator. HQ=0.1, May 2022 Groundwater screening levels based on residential scenario for direct ingestion of groundwater.

AOI01 AOI02

AOI02-01-GW

04/08/2022

AOI02-01-GW-D

04/08/2022

AOI01-02-GW

04/09/2022

TUL-MW001-GW

04/10/2022

Area of Interest

Sample ID

Sample Date

AECOM 
Site Inspection Report

Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 6-10

THIS PAGE INTENTIONALLY BLANK
AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI01-03

AOI01-04

AOI02-01

TUL-MW002

AOI02-02

AOI03-01

AOI01-06

AOI01-05

AOI02-03

AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI02-01

TUL-MW002

AOI02-02

AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI02-01

TUL-MW002

0 4 200 00 800

Feet

Shallow Intermediate Deep

­ Figure 6-1

CLIENT

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PROJECT

ARNG

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9/13/2022

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Facility Boundary

PFOA Detections in Soil

12420 Milestone Center Drive

Germantown, MD 20876

PFOA Results (μg/Kg)

ND

>ND - 19

>19 - 250

>250 - 2,500

>2,500

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

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

AECOM 6-11
AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI01-03

AOI01-04

AOI02-01

TUL-MW002

AOI02-02

AOI03-01

AOI01-06

AOI01-05

AOI02-03

AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI02-01

TUL-MW002

AOI02-02

AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI02-01

TUL-MW002

0 4 200 00 800

Feet

Shallow Intermediate Deep

­ Figure 6-2

CLIENT

REVISED

SCALE

PROJECT

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9/13/2022

9/13/2022

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Legend

Facility Boundary

PFOS Detections in Soil

12420 Milestone Center Drive

Germantown, MD 20876

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

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

PFOS Results (μg/Kg)

ND

>ND - 13

>13 - 160

>160 - 1,600

>1,600

AECOM 6-12
AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI01-03

AOI01-04

AOI02-01

TUL-MW002

AOI02-02

AOI03-01

AOI01-06

AOI01-05

AOI02-03

AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI02-01

TUL-MW002

AOI02-02

AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI02-01

TUL-MW002

0 4 200 00 800

Feet

Shallow Intermediate Deep

­ Figure 6-3

CLIENT

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SCALE

PROJECT

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Facility Boundary

PFBS Detections in Soil

12420 Milestone Center Drive

Germantown, MD 20876

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

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

PFBS Results (μg/Kg)

ND

>ND - 10

>10 - 1,900

>1,900 - 25,000

>25,000

AECOM 6-13
AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI01-03

AOI01-04

AOI02-01

TUL-MW002

AOI02-02

AOI03-01

AOI01-06

AOI01-05

AOI02-03

AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI02-01

TUL-MW002

AOI02-02

AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI02-01

TUL-MW002

0 4 200 00 800

Feet

Shallow Intermediate Deep

­ Figure 6-4

CLIENT

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SCALE

PROJECT

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9/13/2022

9/13/2022

9/13/2022

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Facility Boundary

PFHxS Detections in Soil

12420 Milestone Center Drive

Germantown, MD 20876

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

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

PFHxS Results (μg/Kg)

ND

>ND - 10

>10 - 130

>130 - 1,600

>1,600

AECOM 6-14
AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI01-03

AOI01-04

AOI02-01

TUL-MW002

AOI02-02

AOI03-01

AOI01-06

AOI01-05

AOI02-03

AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI02-01

TUL-MW002

AOI02-02

AOI01-01

TUL-MW001

AOI01-02

TUL-MW003

AOI02-01

TUL-MW002

0 4 200 00 800

Feet

Shallow Intermediate Deep

­ Figure 6-5

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Tulsa AASF #2, OK

9/13/2022

9/13/2022

9/13/2022

MS

VG

CM

GIS BY

CHK BY

PM

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

9/13/2022

1:4,800

Legend

Facility Boundary

PFNA Detections in Soil

12420 Milestone Center Drive

Germantown, MD 20876

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

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

PFNA Results (μg/Kg)

ND

>ND - 19

>19 - 250

>250 - 2,500

>2,500

AECOM 6-15
AOI01-01

TUL-MW001

AOI01-02

AOI02-01

AOI01-01

TUL-MW001

AOI01-02

AOI02-01

AOI01-01

TUL-MW001

AOI01-02

AOI02-01

0 200 400 800

Feet

PFOA PFOS PFBS

­ Figure 6-6

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Tulsa AASF #2, OK

10/10/2022

10/10/2022

10/10/2022

MS

VG

CM

GIS BY

CHK BY

PM

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

10/10/2022

1:4,800

Legend

Facility Boundary

Groundwater Flow Direction

PFOA, PFOS, and PFBS Detections in Groundwater

12420 Milestone Center Drive

Germantown, MD 20876

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

PFBS Results (ng/L)

ND

>ND - 100

>100 - 601

>601 - 2,000

>2,000

PFOS Results (ng/L)

ND

>ND - 4

>4 - 40

>40 - 70

>70

PFOA Results (ng/L)

ND

>ND - 6

>6 - 40

>40 - 70

>70

AECOM 6-16
AOI01-01

TUL-MW001

AOI01-02

AOI02-01

AOI01-01

TUL-MW001

AOI01-02

AOI02-01

0 200 400 800

Feet

PFHxS PFNA

­ Figure 6-7

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection at Tulsa AASF #2, OK

10/10/2022

10/10/2022

10/10/2022

MS

VG

CM

GIS BY

CHK BY

PM

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

10/10/2022

1:4,800

Legend

Facility Boundary

Groundwater Flow Direction

PFHxS and PFNA Detections in Groundwater

12420 Milestone Center Drive

Germantown, MD 20876

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

PFNA Results (ng/L)

ND

>ND - 6

>6 - 100

>100 - 1,000

>1,000

PFHxS Results (ng/L)

ND

>ND - 39

>39 - 100

>100 - 1,000

>1,000

AECOM 6-17
Site Inspection Report

Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 6-18

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 7-1

7. Exposure Pathways

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

Figure 7-3. Please note that while the CSM discussion assists in determining if a receptor may 

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

exceedances of the SLs for the relevant compounds and whether the release is more 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 1 consists of the Eastern Release Areas, where controlled AFFF releases through fire

training activities have occurred as early as the 1990s until the early 2000s, a wash rack with 

associated OWS and evaporator are located, two fire suppression system releases occurred in 

2014, and bulk AFFF containers were stored. Releases at AOI 1 have occurred on both paved 

areas and grassy surfaces. Some PFAS releases may have occurred directly onto surface soil 
Site Inspection Report

Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 7-2

but may also have infiltrated to subsurface soil via cracks or joints in the pavement. Any 

releases that occurred in the hangars or wash rack would have drained to the OWS and 

evaporator or, as was the case prior to the evaporator installation in 2010, potentially discharged 

to the surface towards Mingo Creek.

PFOA, PFOS, PFHxS, and PFNA were detected below their SLs in surface soil at AOI 1. Site 

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

ingestion and inhalation of dust. No ongoing construction was observed at the facility during the 

SI. Therefore, the surface soil exposure pathway for site workers and future construction 

workers are potentially complete. The facility is gated and there are no adjacent residential 

structures; therefore, the incidental ingestion and inhalation of dust exposure pathways for the 

trespasser, residential, and recreational user receptors are considered incomplete. PFOS, 

PFHxS, and PFNA were detected below their SLs in shallow subsurface soil at AOI 1. The 

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

feet bgs. Construction workers could contact constituents in subsurface soil via incidental 

ingestion; therefore, the subsurface soil exposure pathway for future construction workers is 

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

7.1.2 AOI 2

AOI 2 consists of the Western FTAs, where controlled AFFF releases through fire training 

activities have occurred as early as the 1990s until the early 2000s. Releases at AOI 2 occurred 

on paved surfaces and may have flowed westward, off the pavement, toward Mingo Creek, and 

potentially impacted surface soil. Additionally, AFFF may also have infiltrated to subsurface soil 

via cracks or joints in the pavement.

PFOA, PFOS, PFHxS, and PFNA were detected below their SLs in surface soil at AOI 2. Site 

workers and future 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 future construction workers are potentially complete. The incidental ingestion and inhalation 

of dust exposure pathways for the trespasser, residential, and recreational user receptors are 

considered incomplete for the same reasons established for AOI 1. PFOS and PFHxS were 

detected below the SLs in shallow subsurface soil at AOI 2. Construction workers could contact 

constituents in subsurface soil via incidental ingestion; therefore, the subsurface soil exposure 

pathway for future construction workers is potentially complete. The CSM for AOI 2 is presented 

on Figure 7-2. 

7.1.3 AOI 3

AOI 3 is a former HEMTT Storage area where Tri-MaxTM extinguishers stored from the 1990s to 

the early 2000s. No known AFFF releases occurred at AOI 3; however, any potential releases 

would have occurred on paved areas. AFFF released to the pavement could have infiltrated to

subsurface soil via cracks or joints in the pavement or joints, or run off to nearby grassy 

surfaces.

PFOA, PFOS, PFBS, PFHxS, and PFNA were detected below the SLs in surface soil at AOI 3.

Site workers and future 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 future construction workers are potentially complete. The incidental ingestion and 

inhalation of dust exposure pathways for the trespasser, residential, and recreational user 

receptors are considered incomplete for the same reasons as the other AOIs. The subsurface 

soil was not sampled at AOI 3; therefore, the pathways for subsurface soil ingestion for all 

receptors cannot be directly evaluated but are conservatively considered to be similar to AOI 1 
Site Inspection Report

Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 7-3

and AOI 2 due to the presence of relevant compounds in surface soil. The CSM for AOI 3 is 

presented on Figure 7-3.

7.2 Groundwater Exposure Pathway

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

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

7.2.1 AOI 1

PFOA, PFOS, and PFHxS were detected above their SLs in groundwater samples collected at 

AOI 1. Drinking water at the facility is provided by the City of Tulsa and is sourced from surface 

water upstream from the facility; therefore, the ingestion exposure pathway for site workers is 

considered incomplete. Three domestic wells are present within a 2.5-mile radius of the facility. 

Based on available information, the nearest of these wells is just under 1 mile to the southeast, 

in the observed upgradient direction from AASF #2, and has a depth of 24 feet bgs. The 

downgradient domestic well is shown as being 197 feet deep. Groundwater encountered during 

the SI was observed in the shallow unconsolidated soil. It is not anticipated that the groundwater 

evaluated during the SI interacts with these potential off-facility water sources. Therefore, the 

pathway for exposure to off-facility residents and recreation users via ingestion of groundwater 

is considered incomplete. Depths to water measured at AOI 1 in April 2022 during the SI ranged 

from 8.36 to 11.18 feet bgs. The construction worker exposure scenario assumes excavation 

occurs at depths at or above 15 feet bgs. Based on the shallow groundwater and constituents

encountered at AOI 1, the ingestion exposure pathway for future construction workers is 

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

7.2.2 AOI 2

PFOA, PFOS, and PFHxS were detected above their SLs in groundwater samples collected at 

AOI 2. Drinking water is sourced from surface water upstream from the facility; therefore, the 

ingestion exposure pathway for site workers is considered incomplete via drinking water. Based 

on the understanding of groundwater conditions at the facility and location of identified wells in 

the vicinity, the pathway for exposure to off-facility residents and recreational users via ingestion 

of groundwater is considered incomplete. Depth to water measured at AOI 2 in April 2022 during 

the SI was 1.24 feet bgs; therefore, the incidental ingestion exposure pathway for future 

construction workers, and potentially site workers due to the shallow groundwater, is considered 

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

7.2.3 AOI 3

Groundwater samples were not collected at AOI 3. Because groundwater was not sampled at 

this AOI, the groundwater exposure pathway cannot be directly evaluated. The CSM for AOI 3 is 

presented on Figure 7-3.

7.3 Surface Water and Sediment Exposure Pathway

Surface water and sediment samples were not collected during the SI field mobilization at AASF 

#2. The SI results in soil and groundwater, in combination with knowledge of the fate and 

transport properties of PFAS, were used to determine whether a potentially complete pathway 

exists between the source and potential receptors.
Site Inspection Report

Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 7-4

7.3.1 AOI 1 and AOI 2

At AOI 1 and AOI 2, PFOA, PFOS, PFHxS, and PFNA were detected in soil, and PFOA, PFOS, 

and PFHxS were detected in groundwater. Concentrations of PFOS, PFNA, and PFHxS below 1 

μg/kg were detected at location AOI01-04, the surface soil sample collected at the OWS surface 

discharge point at the facility boundary, upslope from Mingo Creek. Surface water features were 

not observed within the facility boundary during the SI; therefore, the surface water and 

sediment ingestion exposure pathway for site workers and future construction workers is

considered incomplete. 

PFAS are water soluble and can migrate readily from soil to surface water via leaching and runoff. It is possible that the compounds detected in soil may have migrated to Mingo Creek, 

located directly west of the facility and topographically downgradient of the facility. Additionally,

exposed bedrock is apparent in the creek bed; therefore, based on the current understanding of 

shallow groundwater relative to the near-surface bedrock, the detected compounds in 

groundwater may migrate to Mingo Creek via shallow groundwater discharge. Consequently, 

the surface water and sediment ingestion exposure pathway for off-facility recreational users is 

also considered potentially complete. Drinking water for the City of Tulsa and surrounding area 

is provided by surface water sourced upstream from Mingo Creek. Therefore, the surface water 

exposure pathway for off-facility residents is considered incomplete. The CSMs for AOI 1 and 

AOI 2 are presented on Figure 7-1 and Figure 7-2, respectively. 

7.3.2 AOI 3 

PFOA, PFOS, PFBS, PFHxS, and PFNA were detected in surface soil at AOI 3. Subsurface soil 

and groundwater were not sampled at this AOI during the SI. Surface water features were not 

observed within the facility boundary during the SI; therefore, the surface water and sediment 

ingestion exposure pathway for site workers and future construction workers is considered 

incomplete. 

Due to the water-soluble property of PFAS, it is possible the compounds detected in the surface 

soil at AOI 3 may have migrated via shallow groundwater discharge or surface runoff to Mingo 

Creek. Therefore, the surface water and sediment ingestion exposure pathway for off-facility 

recreational users is also considered potentially complete. Surface water from Mingo Creek is 

not used as drinking water in the vicinity, so the surface water ingestion exposure pathway for 

off-facility residents is considered incomplete. The CSM for AOI 3 is presented on Figure 7-3. 
Media

SOURCE PATHWAY R

AOI 1

AFFF Fire 

Suppression 

System, AFFF 

Storage, and 

AFFF 

Discharge 

During Fire 

Training 

Activities

Subsurface 

Soil

Human 

Activities

Precipitation/ 

Run-Off

Leaching/ 

Infiltration

Airborne Soil 

Particulate

Surface Soil 

Surface 

Water/ 

Sediment

Subsurface 

Soil

Shallow 

Groundwater

Source Release Mechanism Media Transport and Migration Media Exposure Routes

Inhalation of 

Dust

IngestionIngestion

Ingestion

Ingestion

Hu

C

Flow-Chart ContinuesPartial / Possible FlowFlow-Chart StopsIncomplete PathwayPotentially Complete PathwayPotentially Complete Pathway with Exceedance of SL

LEGEND

Figure 7

Conceptual Site M

Tulsa AASF #2, Tul

Potential 

Off-Facility 

Source Not 

Under 

Control of 

ARNG

Surface 

Water

Surface 

Water Flow

NOTES1. The resident and recreational users referto off-site receptors.2. Construction was not observed during SIfield activities.

Surface Soil

/ 

Site 

Worker

Con

W

Site 

Worker

Con

W

/ / 

/ 

/ 
Media

SOURCE PATHWAY

AOI 2

AFFF 

Discharge 

During Fire 

Training 

Activities

Surface Soil

Subsurface 

Soil

Human 

Activities

Precipitation/ 

Run-Off

Leaching/ Infiltration

Airborne Soil 

Particulate

Surface Soil 

Surface 

Water/ 

Sediment

Subsurface 

Soil

Shallow 

Groundwater

Source Release Mechanism Media Transport and Migration Media Exposure Routes

Inhalation of 

Dust

IngestionIngestion

Ingestion

Ingestion

Flow-Chart ContinuesPartial / Possible FlowFlow-Chart StopsIncomplete PathwayPotentially Complete PathwayPotentially Complete Pathway with Exceedance of SL

LEGEND

Figure 7

Conceptual Site M

Tulsa AASF #2, Tul

Potential 

Off-Facility 

Source Not 

Under 

Control of 

ARNG

Surface 

Water

Surface 

Water Flow

NOTES1. The resident and recreational users referto off-site receptors.2. Construction was not observed during SIfield activities.

R

Hu

C

/ 

Site 

Worker

Con

W

Site 

Worker

Con

W

/ / 

/ 

/ 
Media

SOURCE PATHWAY

AOI 3 AFFF Storage 

Surface Soil

Subsurface 

Soil

Human 

Activities

Precipitation/ 

Run-Off

Leaching/ Infiltration

Airborne Soil 

Particulate

Surface Soil 

Surface 

Water/ 

Sediment

Subsurface 

Soil

Shallow 

Groundwater

Source Release Mechanism Media Transport and Migration Media Exposure Routes

Inhalation of 

Dust

IngestionIngestion

Ingestion

Ingestion

Flow-Chart ContinuesPartial / Possible FlowFlow-Chart StopsIncomplete PathwayPotentially Complete PathwayPotentially Complete Pathway with Exceedance of SL

LEGEND

Figure 7

Conceptual Site M

Tulsa AASF #2, Tul

Potential 

Off-Facility 

Source Not 

Under 

Control of 

ARNG

Surface 

Water

Surface 

Water Flow

NOTES1. The resident and recreational users referto off-site receptors2. Subsurface soil and groundwater was notsampled at AOI 3.3. Construction was not observed during SIfield activities.

/ 

Site 

Worker

Con

W

Site 

Worker

Con

W

/ / 

/ 

/ 

R

Hu

C
Site Inspection Report

Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 7-8

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Army Aviation Support Facility #2, Tulsa, Oklahoma

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 4 to 14 April 2022 and consisted of utility clearance, 

sonic drilling, soil sample collection, temporary monitoring well installation, grab groundwater 

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

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

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

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

QSM 5.3 Table B-15 as follows. 

• Twenty-six (26) soil samples from thirteen (13) locations;

• Four (4) grab groundwater samples from four (4) of six (6) temporary wells; and

• Sixteen (16) QA/QC samples.

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

and/or disposal of PFAS-containing materials. The SI includes multi-media sampling at AOIs to 

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

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

required. Additionally, the CSMs were refined to assess whether a potentially complete pathway 

exists between the source and potential receptors for potential exposure at the AOIs, which are 

described in Section 7. 

8.2 Outcome 

Based on the results of this SI, further evaluation is warranted in an RI for AOI 1: Eastern 

Release Area and AOI 2: Western FTAs. No further evaluation is warranted for AOI 3 at this 

time. Based on the CSMs developed and revised in light of the SI findings, there is no potential 

for exposure to drinking water receptors 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 PFOA, PFOS, PFHxS, and PFNA in soil at AOI 1

were below their SLs. PFBS was not detected.

• PFOA, PFOS, and PFHxS in groundwater exceeded their respective SLs. PFOA

exceeded the 6 ng/L SL, with a maximum concentration of 59.9 ng/L at TULMW001. PFOS exceeded the 4 ng/L SL, with a maximum concentration of 267 ng/L

at TUL-MW001. PFHxS exceeded the 39 ng/L SL, with a maximum concentration

of 3,100 ng/L at TUL-MW001. PFBS and PFNA were below their SLs.

• Based on the results of the SI, further evaluation of AOI 1 is warranted in the RI.
Site Inspection Report

Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 8-2

• At AOI 2: 

• The detected concentrations of PFOA, PFOS, PFHxS, and PFNA in soil at AOI 1 

were below their SLs. PFBS was not detected.

• At AOI02-01, PFOA exceeded the 6 ng/L SL, with a maximum concentration of 8.79 

ng/L. PFOS exceeded the 4 ng/L SL, with a maximum concentration of 141 J ng/L.

PFHxS exceeded the 39 ng/L SL, with a maximum concentration of at 382 ng/L. 

PFBS was detected below the SL. PFNA was not detected.

• Based on the results of the SI, further evaluation of AOI 2 is warranted in the RI.

• At AOI 3: 

• The detected concentrations of PFOA, PFOS, PFBS, PFHxS, and PFNA in surface 

soil at AOI 1 were below their SLs.

• Subsurface soil and groundwater were not sampled at AOI 3.

Groundwater availability was limited during the SI at the facility and several locations were 

unable to be sampled. Groundwater depths were generally observed to be approximately 1 to 2 

feet above the bedrock and/or fat clay layers encountered within the soil borings. This suggests 

that the shallow groundwater flow at the facility is more locally rather than regionally influenced.

The availability of groundwater appeared to correlate to where the unconsolidated material was 

less compacted and had higher silt content that allowed some degree of infiltration for shallow 

groundwater production. In less permeable areas, surface water disposition is likely dominated 

by runoff rather than infiltration. Groundwater was not observed in the well-cemented limestone 

bedrock, identified as the Oologah Formation, at Tulsa AASF #2. It is expected that the first 

available groundwater would not likely be encountered until at or within the underlying shale 

Labette Formation, expected at a depth of around 110 to 130 feet bgs. 

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 Future Action

1 Eastern Release Areas Proceed to RI 

2 Western FTAs Proceed to RI 

3 HEMTT Storage 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

Army Aviation Support Facility #2, Tulsa, Oklahoma

AECOM 9-1

9. References 

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

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

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

W912DR17F0192. 9 March.

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

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

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

AECOM. 2020. Final Preliminary Assessment Report, Tulsa Army Aviation Support Facility #2, 

Tulsa, Oklahoma. October. 

AECOM. 2021. Final Site Inspection Uniform Federal Policy-Quality Assurance Project Plan 

Addendum, Army Aviation Support Facility #2, Tulsa, Oklahoma. September.

AECOM. 2020. Final Preliminary Assessment Report, Tulsa Army Aviation Support Facility, 

Oklahoma. January. 

AECOM. 2021. Final Site Inspection Uniform Federal Policy-Quality Assurance Project Plan 

Addendum, Army Aviation Support Facility, Tulsa, Oklahoma, Perfluorooctane Sulfonic Acid 

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

September.

AECOM. 2022. Final Site Safety and Health Plan, Army Aviation Support Facility, Tulsa, 

Oklahoma, Perfluorooctane Sulfonic Acid (PFOS) and Perfluorooctanoic Acid (PFOA) 

Impacted Sites ARNG Installations, Nationwide. March. 

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

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

6 July. 

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

4 September.

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.

E&E Engineering and Associates, LLC. 2018. Appendix F Groundwater Sampling and Analysis 

Plan. APAC East Quarry C&D Landfill, Tulsa County, Oklahoma, SW Permit No. 3572049. 

June.

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. 
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AECOM 9-2

Johnson, Kenneth S. 1983. Maps Showing Principal Ground-water Resources and Recharge 

Areas in Oklahoma: Sheet 2 – Bedrock aquifers and Recharge Areas. Oklahoma Geological 

Survey, Geologic Map 43.

Leidos. 2018. Site Inspection Report for Perfluorooctane Sulfonate and Perfluorooctanoic Acid 

at Tulsa Air National Guard Base Tulsa, Oklahoma. November.

Marcher, M.V., and Bingham, R.H. 1971. Reconnaissance of the Water Resources of the Tulsa 

Quadrangle, Northeastern Oklahoma. Oklahoma State Geological Survey, Hydrologic Atlas 

2. 4 sheets.

Miller, G.W., and Stanley, T.M. 2006. Geologic Map of the Mingo 7.5’ Quadrangle, Rogers, 

Tulsa, and Wagoner Counties, Oklahoma. Oklahoma Geological Survey, Oklahoma 

Geologic Quadrangle 70.

Oklahoma Climatological Survey. 2011. Climate of Oklahoma. Accessed 7 October 2022 at 

https://climate.ok.gov/index.php/site/page/climate_of_oklahoma. 

Oklahoma Water Resource Board. 2020. Groundwater Wells, Standards, and Protection in 

Oklahoma. Accessed February 2020 at 

https://owrb.maps.arcgis.com/apps/webappviewer/index.html?id=ed61209c40ec4f53bc51d2

ffd18aa39b 

Oneida Total Integrated Enterprises. 2018. Final Site Inspection Report, Site Inspection of 

Aqueous Film Forming Foam (AFFF) Release Areas, Environmental Programs Worldwide, 

Air Force Plant #3 Tulsa, Oklahoma. August.

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

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

(CERCLA). 

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