FINAL

Site Inspection Report 

Esler Field Army Aviation Support Facility

Louisiana

Perfluorooctanesulfonic Acid (PFOS) and 

Perfluorooctanoic Acid (PFOA) Impacted Sites

ARNG Installations, Nationwide

June 2022 

Prepared for:

Army National Guard Bureau

111 S. George Mason Drive

Arlington, VA 22204

UNCLASSIFIED
 

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM i

Table of Contents

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

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

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

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

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

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

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

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

2.2.2 Soil ................................................................................................................ 2-2

2.2.3 Hydrogeology ............................................................................................... 2-2

2.2.4 Hydrology ..................................................................................................... 2-3

2.2.5 Climate ......................................................................................................... 2-4

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

2.2.7 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....................................................................................................................... 3-1

3.1.1 Sewage Oxidation Pond ............................................................................... 3-1

3.2 AOI 2....................................................................................................................... 3-1

3.2.1 North Ramp/Wash Rack............................................................................... 3-1

3.2.2 Hangar Buildings 6001 and 6002 ................................................................. 3-1

3.3 AOI 3....................................................................................................................... 3-2

3.3.1 South Ramp.................................................................................................. 3-2

3.4 AOI 4....................................................................................................................... 3-2

3.4.1 Firehouse Building 6004............................................................................... 3-2

3.4.2 Storage Building 6067/6068 ......................................................................... 3-2

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

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

4.2 Goals of the Study .................................................................................................. 4-1

4.3 Information Inputs ................................................................................................... 4-2

4.4 Study Boundaries ................................................................................................... 4-2

4.5 Analytical Approach ................................................................................................ 4-2

4.6 Data Usability Assessment ..................................................................................... 4-3

4.6.1 Precision ....................................................................................................... 4-3

4.6.2 Accuracy....................................................................................................... 4-4

4.6.3 Representativeness...................................................................................... 4-5

4.6.4 Comparability................................................................................................ 4-5

4.6.5 Completeness............................................................................................... 4-5

4.6.6 Sensitivity ..................................................................................................... 4-6

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 PFAS Sampling Equipment Acceptability ....................... 5-2
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM ii

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

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

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

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

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

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

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

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

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

6.2 Soil Physicochemical Analyses............................................................................... 6-1

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........................................................................................ 6-4

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

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

6.5.2 AOI 3 Groundwater Analytical Results ......................................................... 6-4

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

6.6 AOI 4....................................................................................................................... 6-5

6.6.1 AOI 4 Soil Analytical Results ........................................................................ 6-5

6.6.2 AOI 4 Conclusions........................................................................................ 6-5

6.7 Sitewide .................................................................................................................. 6-5

6.7.1 Sitewide Soil Analytical Results.................................................................... 6-5

6.7.2 Sitewide Groundwater Analytical Results ..................................................... 6-6

6.7.3 Sitewide Conclusions ................................................................................... 6-6

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

7.1.4 AOI 4 ............................................................................................................ 7-2

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

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

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

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

7.2.4 AOI 4 ............................................................................................................ 7-3

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

7.3.1 AOI 1 ............................................................................................................ 7-4

7.3.2 AOI 2 ............................................................................................................ 7-4

7.3.3 AOI 3 ............................................................................................................ 7-4

7.3.4 AOI 4 ............................................................................................................ 7-4

8. Summary and Outcome ................................................................................................. 8-1
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM iii

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

8.2 SI Goals Evaluation ................................................................................................ 8-1

8.3 Outcome ................................................................................................................. 8-2

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

Esler Field Army Aviation Support Facility, Louisiana

AECOM iv

Appendices

Appendix A Data Validation Reports

Appendix B Field Documentation

B1. Log of Daily Notice of Field Activities

B2. Sampling Forms

B3. Survey Data

Appendix C Photographic Log

Appendix D TPP Meeting Minutes

Appendix E Boring Logs

Appendix F Analytical Results

Appendix G Laboratory Reports

Figures

Figure 2-1 

Figure 2-2 

Figure 2-3 

Figure 2-4 

Figure 2-5 

Figure 3-1 

Figure 5-1 

Figure 6-1 

Figure 6-2 

Figure 6-3 

Figure 6-4 

Figure 7-1 

Facility Location 

Facility Topography Map

Groundwater Features

Surface Water Features 

Groundwater Elevation Contours

Area of Interest 

Site Inspection Sample Locations

PFOA Detections in Soil

PFOS Detections in Soil

PFBS Detections in Soil

PFOA, PFOS, and PFBS Detections in Groundwater

Conceptual Site Model, AOI 1

Figure 7-2 Conceptual Site Model, AOI 2

Figure 7-3 Conceptual Site Model, AOI 3

Figure 7-4 Conceptual Site Model, AOI 4

Tables

Table ES-1 Screening Levels (Soil and Groundwater)

Table ES-2 Summary of Site Inspection Findings

Table ES-3 Site Inspection Recommendations

Table 5-1 Site Inspection Samples by Medium

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

Elevations

Table 6-1 Screening Levels (Soil and Groundwater)

Table 6-2 PFAS Detections in Surface Soil

Table 6-3 PFAS Detections in Shallow Subsurface Soil

Table 6-4 PFAS Detections in Groundwater

Table 8-1 Summary of Site Inspection Findings

Table 8-2 Site Inspection Recommendations
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM v

Acronyms and Abbreviations

% percent

°C degrees Celsius

°F degrees Fahrenheit

μg/kg micrograms per kilogram

6:2 FTS 6:2 Fluorotelomer sulfonic acid

8:2 FTS 8:2 Fluorotelomer sulfonic acid

AASF Army Aviation Support Facility

AECOM AECOM Technical Services, Inc.

AFFF aqueous film forming foam

AOI Area of Interest

ARNG Army National Guard

ASTM American Society of 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

DL detection limit

DoD Department of Defense

DPT direct push technology

DQI data quality indicator

DQO data quality objective

DUA data usability assessment

DVR data validation report 

EDRTM Environmental Data Resources, Inc.TM

EIS extraction internal standards

ELAP Environmental Laboratory Accreditation Program

EM Engineer Manual

ERB equipment rinsate blank

FedEx Federal Express

GPRS Ground Penetrating Radar Systems, LLC.

HA Health Advisory

HDPE high-density polyethylene 

IDW investigation-derived waste

IIS injection internal standards

ITRC Interstate Technology Regulatory Council

LAARNG Louisiana Army National Guard

LC/MS/MS liquid chromatography with tandem mass spectrometry

LCS laboratory control spike

LCSD laboratory control spike duplicate

LOD limit of detection

LOQ limit of quantitation

MDL method detection limit
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM vi

MS matrix spike 

MSD matrix spike duplicate

n.d. no date

NELAP National Environmental Laboratory Accreditation Program

NEtFOSAA N-ethyl perfluorooctanesulfonamidoacetic acid

ng/L nanograms per liter

NMeFOSAA N-methyl perfluorooctanesulfonamidoacetic acid

NOAA National Oceanic and Atmospheric Administration

OSD Office of the Secretary of Defense

OWS oil/water separator

P&A plugged and abandoned

PA Preliminary Assessment

PFAS per- and polyfluoroalkyl substances

PFBA perfluorobutyrate

PFBS perfluorobutanesulfonic acid

PFCs perfluorinated compounds

PFDA perfluorodecanoic acid

PFDoA perfluorododecanoic acid

PFHpA perfluoroheptanoic acid

PFHxA perfluorohexanoic acid

PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

PFOA perfluorooctanoic acid

PFOS perfluorooctanesulfonic acid

PFPeA perfluoropentanoic acid

PFTeDA perfluorotetradecanoic acid

PFTrDA perfluorotridecanoic acid

PFUdA perfluoroundecanoic acid

PID photoionization detector

PQAPP Programmatic UFP-QAPP

PVC polyvinyl chloride

QA quality assurance

QAPP Quality Assurance Project Plan

QC quality control

QSM Quality Systems Manual

RI Remedial Investigation

RPD relative percent differences

SI Site Inspection

SL screening level

SOP standard operating procedure

TCRA Time Critical Removal Action

TOC total organic carbon

TPP Technical Project Planning

UCMR 3 Unregulated Contaminant Monitoring Rule 3

UFP Uniform Federal Policy
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM vii

US United States

USACE United States Army Corps of Engineers

USACHPPM United States Army Center for Health Promotion and Preventative Medicine

USAEHA United States Army Environmental Hygiene Agency 

USCS Unified Soil Classification System

USDA United States Department of Agriculture

USEPA United States Environmental Protection Agency

USFWS United States Fish and Wildlife Service

USGS United States Geological Survey

VFD Volunteer Fire Department

WWD #3 Water Works District No. 3
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM viii

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM ES-1

Executive Summary

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

Inspections (SIs) at per- and polyfluoroalkyl substances (PFAS)-impacted sites at ARNG facilities 

nationwide. The objective of the SI at each facility is to identify whether there has been a release 

to the environment from the Areas of Interest (AOIs) identified in the PA and determine the 

presence or absence of perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and 

perfluorobutanesulfonic acid (PFBS) at or above screening levels (SLs). An SI was completed at

Esler Field Army Aviation Support Facility (AASF), near Pineville, Louisiana. Esler Field AASF will 

also be referred to as the “facility” throughout this document. 

Esler Field AASF occupies 1,991 acres along on Route 116 (Esler Field Road), adjacent to the 

Camp Beauregard Training Site. The facility is used for numerous training exercises. Roughly 

60% and 40% of the airport’s operations are military and civilian, respectively. The MMR Group 

and Crest Industries have facilities at Esler Field AASF and each support multiple aircraft.

During the PA for PFAS, six potential PFAS release areas were identified: Sewage Oxidation 

Pond, North Ramp/Wash Rack, Hangar Buildings 6001 and 6002, South Ramp, Firehouse 

Building 6004, and Storage Building 6067/6068 (AECOM, 2020). PFAS-containing aqueous film

forming foam (AFFF) may have been released during fire training activities at the North 

Ramp/Wash Rack and South Ramp. Releases at these locations would be conveyed to the 

Sewage Oxidation Pond via stormwater drainage. AFFF has also been historically stored at 

Firehouse Building 6004, Storage Building 6067/6068, and the Hangar Buildings 6001 and 6002. 

The potential PFAS release areas were grouped into four AOIs, AOI 1 through AOI 4, which were

investigated during the SI. The SI field activities were conducted from 26 July to 3 August 2021

and included the collection of soil and groundwater samples.

To fulfill the project Data Quality Objectives set forth in the approved SI Quality Assurance Project 

Plan Addendum (AECOM, 2021a), samples were collected and analyzed for a subset of 18 PFAS 

by liquid chromatography with tandem mass spectrometry compliant with Quality Systems Manual 

5.3 Table B-15. The 18 PFAS analyzed as part of the ARNG SI program are specified in Section 

5.9 of this Report. 

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 Office of the Secretary of 

Defense (OSD) dated 15 September 2021 (Assistant Secretary of Defense, 2021). 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 three compounds: PFOS, PFOA, and PFBS. 

The SLs are presented on Table ES-1 below. All other results presented in this report are 

considered informational in nature and serve as an indication as to whether soil and groundwater

contain or do not contain the 18 PFAS analyzed within the boundaries of the facility. 

Sample chemical analytical concentrations were compared against the project SLs as described 

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

• At AOI 1, PFOA, PFOS, and PFBS were detected in groundwater at the Sewage Oxidation 

Pond potential PFAS release area but were below the SLs, at concentrations of 5.13 

nanograms per liter (ng/L), 0.810 J ng/L, and 0.856 J ng/L. Based on the results of the SI, 

further evaluation of AOI 1 is not warranted.
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM ES-2

• At AOI 2, PFOA, PFOS, and PFBS were not detected in groundwater at the North 

Ramp/Wash Rack and Hangar Buildings 6001 and 6002 potential PFAS release areas.

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

• At AOI 3, PFOS and PFBS were detected in groundwater at the South Ramp, at 

concentrations below the SLs. The maximum detection of PFOS was 1.41 J ng/L at AOI03-

02, whereas PFBS was only detected at AOI03-03, with a concentration of 7.57 ng/L.

PFOA was not detected in any of the three temporary well locations. Based on the results 

of the SI, further evaluation of AOI 3 is not warranted.

• At AOI 4, no groundwater samples were collected. At the Storage Building 6067/6068,

AOI04-01, PFOA, PFOS, and PFBS were not detected in soil. At the Firehouse Building 

6004, AOI04-02, PFOA, PFOS, and PFBS were detected at concentrations below the SLs.

Based on the results of the SI, further evaluation of AOI 4 is not warranted.

• The detected concentrations of PFOA, PFOS, and PFBS in soil at all AOIs were below the

SLs. 

Table ES-2 summarizes the SI results for soil and groundwater. Based on the conceptual site 

models developed and revised in light of the SI findings, there is potential for exposure to drinking 

water receptors caused by DoD activities at the facility. 

Table ES-3 summarizes the rationale used to determine if an AOI should be considered for further 

investigation under CERCLA and undergo a Remedial Investigation. Based on the results of this 

SI, further evaluation is not warranted at AOI 1: Sewage Oxidation Pond, AOI 2: North 

Ramp/Wash Rack, AOI 2: Hangar Buildings 6001 and 6002, AOI 3: South Ramp, AOI 4: Firehouse 

Building 6004, and AOI 4: Storage Building 6067/6068. 

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

Analyte

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 130 1,600 40

PFOS 130 1,600 40

PFBS 1,900 25,000 600

Notes:

a.) Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS, PFOA, PFBS in Groundwater and Soil using 

United States Environmental Protection Agency’s (USEPA’s) Regional Screening Level Calculator. Hazard Quotient (HQ) = 0.1. 15 

September 2021. 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM ES-3

Table ES-2: Summary of Site Inspection Findings

AOI Potential PFAS 

Release Area

Soil – 

Source Area

Groundwater – 

Source Area

Groundwater –

Facility Boundary

1 Sewage Oxidation Pond N/A

2

North Ramp/Wash Rack N/A

Hangar Buildings 6001 & 

6002 N/A

3 South Ramp

4 

Firehouse Building 6004 N/A N/A

Storage Building 

6067/6068 N/A N/A

Legend:

N/A = not applicable 

= detected; exceedance of the screening levels

= detected; no exceedance of the screening levels

= not detected

Table ES-3: Site Inspection Recommendations

AOI Description Rationale Future Action

1 Sewage Oxidation 

Pond

PFOA, PFOS, and PFBS detected in 

groundwater at source area below the SLs. 

No exceedances of SLs in soil. 

No further action

2 

North Ramp/Wash 

Rack

No detections of PFOA, PFOS, and PFBS 

in groundwater. No exceedances of SLs in 

soil. 

No further action

Hangar Buildings 

6001 & 6002 

No detections of PFOA, PFOS, and PFBS 

in groundwater. No exceedances of SLs in 

soil. 

No further action

3 South Ramp

Detections of PFOS and PFBS in 

groundwater below the SLs. No detections 

of PFOA in groundwater. No exceedances 

of SLs in soil.

No further action

4 

Firehouse Building 

6004 No exceedances of SLs in soil. No further action

Storage Building 

6067/6068

No detections of PFOA, PFOS, or PFBS in 

soil. No further action
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM ES-4

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 1-1

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) for Perfluorooctanesulfonic acid (PFOS) and Perfluorooctanoic 

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

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

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

Order W912DR17F0192, issued 11 August 2017. The ARNG performed this SI at Esler Field Army 

Aviation Support Facility (AASF), near Pineville, Louisiana. Esler Field AASF 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; 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 including specific 

requirements for sampling for PFOA, PFOS, and perfluorobutanesulfonic acid (PFBS), and the 

group of related compounds known in the industry as per- and polyfluoroalkyl substances (PFAS). 

The term PFAS is used throughout this report to encompass all PFAS chemicals being evaluated, 

including PFOA, PFOS, and PFBS, which are the key components of the suspected releases 

being evaluated, and the other 15 related compounds listed in the task order. 

1.2 SI Purpose

A PA was performed at Esler Field AASF (AECOM, 2020) that identified six potential PFAS release 

areas at the facility, which were grouped into four Areas of Interest (AOIs). The objective of the SI 

is to identify whether there has been a release to the environment from the AOIs and determine 

the presence or absence of PFOA, PFOS, and PFBS at or above screening levels (SLs). 

As stated in the Federal Facilities Remedial Site Inspection Summary Guide (USEPA, 2005), an 

SI has five goals: 

1. Develop information to potentially eliminate a release from further consideration because 

it is determined that it poses no significant threat to human health or the environment;

2. Determine the potential need for a removal action;

3. Collect or develop data to evaluate potential release;

4. Collect data to better characterize the release for more effective and rapid initiation of a 

Remedial Investigation (RI), if determined necessary; and

5. Collect data to determine whether the release is more than likely the result of activities 

associated with the Department of Defense (DoD). 

In addition to the USEPA-identified goals of an SI, the ARNG SI also identifies whether there are 

potential off-facility PFAS sources. 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 1-2

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 2-1

2. Facility Background

2.1 Facility Location and Description 

Esler Field AASF is located in central Louisiana, off Louisiana Highway 116 (Esler Field Rd), in 

Rapides Parish, approximately 12 miles northeast of Alexandria (Figure 2-1). Esler Field 

encompasses approximately 1,991 acres and is immediately adjacent (south of) to the 12,889-

acre Camp Beauregard Training Site, which is geographically separate from the 729-acre Camp 

Beauregard Cantonment Area. Esler Field was constructed in 1940 for the US Army Air Corps 

and was originally named Camp Beauregard Army Field. The Air Corps used the facility 

extensively through 1942. The facility was renamed Esler Army Airfield in 1941 to honor 

Lieutenant Esler. In 1945, the facility was reassigned directly to Third Air Force and began the 

process of deactivation. The facility was finally closed in 1946, and it remained Federal property 

until the 1950s, when it was ceded to the Rapides Parish Police Jury as surplus property. Under 

the Rapides Parish Police Jury, the facility served as the City of Alexandria’s commercial airport 

until the 1990s, when commercial traffic was moved to Alexandria International Airport (Louisiana 

ARNG [LAARNG], no date [n.d.]).

In 2001, Rapides Parish Police Jury transferred the facility’s management to the LAARNG in a 

99-year lease, and the facility is now used for numerous training exercises. Currently, roughly 60 

percent (%) of the airport’s operations are military, and the rest are civilian. Although Esler Field 

does not offer private jet passenger services, it does provide both military and civilian aircraft fuel 

services. In December of 2011, the MMR Group, which previously based its aviation operations 

at Alexandria International Airport, completed work on its new corporate aviation facility at Esler 

Field. The facility includes 10,000 square feet of hangar space and 3,000 square feet of office 

space. MMR shares its facilities with Crest Industries, and the two groups currently support 

multiple aircraft. 

2.2 Facility Environmental Setting

Esler Field AASF is located in the Upper West Gulf Coastal Plain physiographic region. The 

topography of the facility is considered gently rolling, and the elevations across the area range 

from approximately 60 to 140 feet above mean sea level. The higher elevations occur on the 

northern most portion of the facility, whereas lower elevations are located along the northern 

floodplain of Flagon Bayou, along the south and eastern boundaries of the facility (LAARNG, 

2007). Topography is shown on Figure 2-2. 

2.2.1 Geology

In general, the geology of central Louisiana is composed of marine sediments deposited during 

fluctuating sea levels, and fluvial sediments deposited by the meandering Mississippi River 

system. These sediments dip less than 5 degrees toward the south-southeast, and their 

compositions range from clays to sands (US Army Environmental Hygiene Agency [USAEHA], 

1994). The Oligocene to Miocene fluvial and marine deposits in the central portion of the State 

comprise, from oldest to youngest, the Catahoula Formation overlain by the Lena, Carnahan 

Bayou, and Dough Hills members of the Fleming Formation (USAEHA, 1994). The Catahoula 

formation contains thick sand beds that are interbedded with thinner clay layers (US Army Center 

for Health Promotion and Preventive Medicine [USACHPPM], 2004). The three members of the 

Fleming Formation consist of consolidated clays with discontinuous silts and sands (USAEHA, 

1994). 

As shown on Figure 2-3, most of Esler Field AASF is mapped as the Dough Hills Member of the 

Miocene Fleming Formation and described as undifferentiated fluviatile silts and sands with 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 2-2

calcareous brackish-water clays (US Geological Survey [USGS], 2019a). Immediately north and 

south are more recent Quaternary alluvial and fluvial deposits overlying the older Oligocene to 

Miocene sediments. These Quaternary deposits are composed of alternating clayey and sandy 

to gravely facies. The sandy to gravely facies have high porosity and permeability, which allow for 

greater rainwater infiltration. The clayey facies act as a surficial confining layer limiting infiltration 

into the underlying formations (USAEHA, 1994). 

In previous studies, soil borings advanced along the western boundary of Camp Beauregard 

Training Site (north of Esler Field) show sediments in a downward coarsening sequence from 

primarily silt at the surface, to sand, and eventually to sand and gravel, at depths between 15 and 

25 feet below ground surface (bgs). An abrupt facies shift from the overlying coarse sand and 

gravel to a stiff clay was identified across the investigation area, at depths ranging from 25 feet to 

35 feet bgs. The thickness of this clay layer was not determined due to direct-push technology 

(DPT) rig refusal. Soil borings advanced near the southwestern boundary of Camp Beauregard 

were noted, with sandy silts observed to fine downward into stiff silty clay and clay, where the 

DPT rig was refused at depths ranging between 15 and 26 feet bgs (USACE, 2014). 

Soil borings completed during the SI were drilled to depths between 20 and 45 feet bgs. The top 

3 to 5 feet of unconsolidated sediments were predominantly coarse-grained sediments (sand and 

gravel), with minor components of fine-grained sediments (silt and clay). Directly underlying these 

surficial sediments were thick layers of fine-grained sediments, characterized as clay-rich silt to 

silt-rich clay, ranging in thickness from 10 to 26 feet. Grain size analyses were collected on the 

fine-grained sediments and are presented in Appendix F. Underlying these thick layers of silt and 

clay are sand-rich lenses with varying minor amounts of silt and clay. These sand lenses are 

characterized as poorly graded sand (<15% fines) to silty/clayey sand (>15% fines) and range 

from 0.5 to 6 feet in thickness. The sands observed at Esler Field AASF were predominantly finegrained, with localized areas of minor medium-grained sand. The sand lenses are interbedded 

with clay- and silt-dominated lenses, often grading from poorly graded sand to silty/clayey sand 

to sandy clay/silt to clay/silt, and vice versa. These facility observations are consistent with the 

fluviatile silts and sands of the Dough Hills Member. Boring logs are presented in Appendix E . 

2.2.2 Soil

Surficial soils at Esler Field consist primarily of fine sandy loam and clay loam derived from marine 

and alluvial Quaternary deposits (US Department of Agriculture [USDA], Soil Conservation 

Service, 1980). Soils present at Esler Field include Beauregard silt loam, Caddo silt loam, Cahaba 

fine sandy loam, and the Libusse silt loam. The Beauregard, Caddo, and Libusse silt loams have 

relatively low permeability, while the Cahaba is well-drained and moderately permeable. All of 

these soil types are described as relatively acidic with slight erodibility (USDA, 2019).

2.2.3 Hydrogeology

Esler Field is underlain by the Coastal Lowlands aquifer system, locally known as the Miocene 

Fleming Formation. The Coastal Lowlands aquifer system consists of a gulf-ward thickening, 

heterogenous, unconsolidated to poorly consolidated wedge of discontinuous beds of sand, silt, 

and clay, with an approximate thickness of 2,000 feet thick in the vicinity of Esler Field. This 

system yields large quantities of water for agricultural, public supply, domestic, commercial, and 

industrial uses (Tomaszewski, 2009). The inferred direction of groundwater flow is north-northeast 

(Figure 2-3). It is possible that the groundwater may locally flow to the southeast, towards Flagon 

Bayou. 

Underlying the Coastal Lowlands aquifer system is the Mississippi Embayment aquifer system, 

which is in poorly consolidated sedimentary rocks of Late Cretaceous to middle Eocene age. The 

two systems are separated by a thick, effective confining unit. Of the six aquifers contained within 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 2-3

the Mississippi Embayment aquifer system, the Middle Claiborne aquifer is the most heavily used; 

it has a reported thickness in the vicinity of Esler Field, ranging from 600 to 800 feet (USGS, 

2019b).

Water to the facility and areas north, south, and west of the facility is supplied by the Water Works 

District No. 3 of Rapides Parish (WWD #3). WWD #3 distributes water sourced from seven 

groundwater wells (40%) and a surface water structure on Big Creek, in Grant Parish, Louisiana 

(60%), over 8 miles north of Esler Field. Two of the WWD #3’s supply wells are located at Camp 

Beauregard. Two wells at Esler Field (#8 and #9) were drilled in 2007 to depths of 651 and 621 

feet, respectively. These wells are offline due to methane, which is cost prohibitive to remove. 

However, well #8 (north of AASF) is used to supply the Esler Field maintenance facility’s fire 

protection system water storage tank (French, 2020). Residents and businesses east of Esler 

Field are served by Buckeye Water District No. 50. The Buckeye District obtains all source water 

from five wells that range from 1,800 to 2,000 feet deep. Two wells (#1 and #2) are located 

northeast of Buckeye, off LA-115 (over 7 miles east of Esler Field); three wells (#3, #4, and #5) 

are located in Libuse, Louisiana (approximately 2 miles south southwest of Esler Field) (Charrier, 

2020). 

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

databases, wells were researched to a 4-mile radius of the facility. A total of 23 wells were 

identified within 1 mile of the facility (Environmental Data Resources, Inc.TM [EDRTM], 2019). One 

well (named Esler Field Well No 2) is located on the northwest portion of the airfield, in the same 

location as Esler Field Well #8 (Figure 2-3). Esler Field Well No 2 is reported as drilled in 1941 to 

a depth of 635 feet bgs and screened from 591 to 633 feet bgs. LAARNG reports this well is 

offline. Six wells are noted as USGS Louisiana Water Science Center wells, with depths ranging 

from 150 to 675 feet bgs, and they are installed in the Carnahan Bayou member of the Fleming 

Formation. The Carnahan Bayou unit is identified as a confined aquifer within the Coastal 

Lowlands aquifer system, with approximate depths to water ranging from 20 to 90 feet. Of the 

remaining 16 wells, one well with a depth of 650 feet bgs is reported as destroyed (owner: 

Louisiana National Guard, immediately north of the facility), and 15 wells are reported as plugged 

and abandoned (P&A). Eleven of the fifteen P&A wells were reported as test holes, with depths 

ranging from 260 to 706 feet bgs, and four of the fifteen wells were reported as monitoring wells 

owned by TEXACO and located in close proximity to the facility, with depths of 30 feet bgs (EDRTM, 

2019). One active domestic well, located approximately 2 miles southeast of the facility, was 

identified with a well depth of 71 feet bgs (Louisiana Department of Natural Resources, 2021).

Based on the USEPA Unregulated Contaminant Monitoring Rule 3 (UCMR 3) data, it was 

indicated that no PFAS were detected in a public water system within 20 miles of the facility 

(USEPA, 2017a). PFAS analyses performed in 2016 had method detection limits (MDLs) that 

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

not detected during the UCMR 3 but might be detected if analyzed today. 

Depths to water measured in August 2021 during the SI ranged from 6.12 to 19.93 feet bgs. 

Groundwater elevation contours from the SI are presented on Figure 2-5 and indicate 

groundwater flow direction is generally toward Flagon Bayou to the south and southwest. 

2.2.4 Hydrology

Esler Field AASF is located in the Lower Flagon Bayou Watershed (Figure 2-4). Surface water in 

the vicinity of the facility consists of perennial and intermittent streams, open water bodies, and 

wetlands. The ground surface slopes to the south, toward Flagon Bayou, which flows east then 

northeast, discharging to Catahoula Lake. Catahoula Lake, which covers over 46 square miles in 

LaSalle Parish, supports multiple species of waterfowl including duck, geese, and wading birds, 

and it is used for recreational fishing and hunting (Horst, 2019). 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 2-4

Wastewater from the facility is conveyed to the west via underground pipe to the small, square, 

lined Sewage Oxidation Pond on the southwest corner of the facility. 

2.2.5 Climate

Esler Field, located in north-central Louisiana, has a sub-tropical climate influenced by its 

proximity to the Gulf of Mexico. The average temperature (1981-2010) for Esler Field is 65 

degrees Fahrenheit (°F), with an average daily low of 37°F in January to an average daily high of 

94°F in August. Annual precipitation is 57.5 inches and is relatively evenly distributed, with the 

lowest precipitation from July to September (National Oceanic and Atmospheric Administration 

[NOAA], 2019). The mean annual relative humidity is 74% (LAARNG, 2007). The mean annual 

evaporation rate in central Louisiana is 45 inches (NOAA, 1982). Thunderstorm activity is most 

common during hurricane season (1 June to 31 October), when tropical storms and hurricanes 

regularly develop in the Gulf of Mexico. The tropical disturbances cause high winds and excessive 

rainfall (LAARNG, 2007). 

2.2.6 Current and Future Land Use

Esler Field AASF is currently leased from Rapides Parish and is primarily used for a variety of 

helicopter-related training activities (LAARNG, 2007). Access to the facility is restricted and 

controlled by fencing and gates. Reasonably anticipated future land use is not expected to change 

from the current land use. Residential areas are located approximately 1 mile to the west and 

1 mile to the southeast.

2.2.7 Sensitive Habitat and Threatened/ Endangered Species 

The following birds, plants, mammals, and reptiles are federally endangered, threatened, 

proposed, and/ or are listed as candidate species in Rapides Parish, Louisiana (US Fish and 

Wildlife Service [USFWS], 2021). 

• Insects: Monarch butterfly, Danaus plexippus (candidate). 

• Mammals: Northern Long-Eared bat, Myotis septentrionalis (threatened).

• Clams: Louisiana pearlshell, Margaritifera hembili (threatened).

• Fish: Pallid sturgeon, Scaphirhynchus albus (endangered).

• Birds: Red-cockaded woodpecker, Picoides borealis (endangered).

• Reptiles: Louisiana pinesnake, Pituophis ruthveni (threatened).

2.3 History of PFAS Use 

Six potential PFAS release areas were identified at the Esler Field AASF during the PA and were

grouped into four AOIs, where aqueous film forming foam (AFFF) may have been used or 

released historically (AECOM, 2020). Esler Field AASF includes two hangars, Hangar Buildings 

6001 and 6002. Both hangars are equipped with water deluge fire suppression systems and 

stores Chemguard 3% AFFF. There have been no reported releases at either of the hangars. 

Between 1996 and 2007, fire training activities with Tri-MaxTM foam carts were used at the North 

Ramp and Wash Rack. From 2005/2006 to 2007, fire training activities involving the Tri-MaxTM 

carts were also conducted at the South Ramp. From the 1980s to through the 1990s, Firehouse 

Building 6004 served as the fire station for the Esler Regional Airport and was the storage location 

of AFFF. AFFF was also stored at Storage Building 6067/6068 up to the time of the PA. 

Descriptions of AOIs 1 through 4 are presented in Section 3. 
CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

SS

9/17/2021

9/17/2021

NOTES Site Inspection for PFAS at Esler Field, LA

1:253,440

9/17/2021 ­ Figure 2-1

PM CM 9/17/2021

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\LA\Esler_Field\Esler_Field_SI_MXDs\SI_Report\Fig_2-1_Esler_Field_FacilityLocation.mxd

12420 Milestone Center Drive

Germantown, MD 20876

Facility Location

^_

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

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

0 2 4 8

Miles

Legend

Facility Boundary

Esler Field

AECOM 2-5
CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

SS

12/14/2021

12/14/2021

NOTES Site Inspection for PFAS at Esler Field, LA

12/14/2021

1:22,800 ­ Figure 2-2 PM CM 12/14/2021

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\LA\Esler_Field\Esler_Field_SI_MXDs\SI_Report\Fig_2-2_Esler_Field_Facility_Topogrpahy.mxd

12420 Milestone Center Drive

Germantown, MD 20876

Facility Topography Map

Base Map: USGS The National Map: National

Boundaries Dataset, 3DEP Elevation Program,

0 950 1,900 3,800

Feet

Legend

Facility Boundary

10 foot contour interval.

AECOM 2-6
A!

A!

A!

!P

A!

!P

!C(

!P

!P

!P

!P

A!

!P

A!

!P

A!

A!

!P

!P

!P

!P

!C(

!P

!C(

A!

!P

A!

!P !C(

A!

!P!P

!P

A!!

A!

A!

!P

A!

!P

!P

!P

!P

!P

!C(

!P

!P

!P

!P

A!

A!

A!

A!

!C(

!P

!P

A!

A!

A! A!

!P

!P !P

!P

!P

!C(

A!

A!!

!P

!C(

!C(

!P

!P

!P !P

!P

!P

!P

!5 !P

A!A! !C(

!P

!P

A!A!

!P

!P

!P

!5

!P

!5

!P

!P

!P

!P

!P

A!

A!!

!C(

!P

!P

!P

!P

!P

!P

A!

Middle Prairie

Catahoula

Lake

Little

Hors epen

C r eek

Brush y F ork

ClearBa you

W aters

B ay ou

Flagon Cree k

Mi ll Creek

Hor sepen

Cree

k

Li ttle Creek

Beaver Creek

Haw

Creek

DryCr e ek

Hai nesC reek

Clinton Branch

Dy son Creek

Fla gon Bayou

Legend

Facility Boundary

Water Body

Wetland

River/Stream

Groundwater Flow Direction

Geology

Recent Alluvium

Prairie Terraces

Intermediate Terraces

High Terraces

Williamson Creek

Carnahan Bayou

Dough Hills

Wells

!P Commercial Public Supply

!P Domestic

!C( Public Supply

!5 Irrigation

A! Monitoring

A! Other - Offline

0 4,000 8,000 16,000

Feet

Q:\Projects\ENV\GEARS\GEO\MAES 2012 Unrestricted\Fort Meade\E. Data Management\GIS\MXDs\Chisholm_6th\March2017\ Fig_2-3_Esler_Field_Groundwater.mxd

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

JH

10/8/2021

10/8/2021

NOTES Site Inspection for PFAS at Esler Field, LA

10/8/2021

Figure 2-3 PM CM 10/8/2021

12420 Milestone Center Drive

Germantown, MD 20876

Groundwater Features

Base Map: Source: Esri, Maxar, GeoEye, Earthstar

Geographics, CNES/Airbus DS, USDA, USGS,

AECOM 

1:96,000 ­

2-7
Hardwater

Lake

Beaver Lake

Bayou

Maria

Basin

Lehman Lake

Middle

Prairie

Catahoula

Lake

Williams Lake

Catfish

Prairie

Brushy

Fork

D u ck Slo ugh

Little River

S al sh Bayou

Bla c kB ran ch

Clea r

M

Bay ou

ill Creek

Cl i

nton Branc h

C onst anti ne

Branc h

Hors epen Cre e k

Litt le

Hor se penC re e k

Haw Cree k

Littl e Cre e k

Beaver Creek

Rou th

Creek

Sch

o

o

lho useBran ch

Big Creek

RedRiver

Eva ns

Br

an ch

Dry C re ek

Ha i nes Creek

Dy son Creek

Fl agon Creek

Bayou

M aria

Wat ersBayo u

Clear Cre ek

Flagon B ayo u

Long Bran ch

Upper Flagon

Bayou Watershed

Kitterlin

Creek

Watershed

Horsepen

Creek

Watershed

Upper

Wiggins

Bayou Watershed

Lower Big

Creek

Watershed

Haines Creek-Dyson

Creek Watershed

Big Creek

Watershed

Big Saline

Bayou

Watershed

Little

River-Catahoula

Lake Watershed

Williams

Lake-Red River

Watershed

Routh Creek-Devils

Creek Watershed

Lower Flagon

Bayou Watershed

Hurricane

Creek-Little

River Watershed

Clear Creek

Watershed

Legend

Facility Boundary

Water Body

Wetland

River/Stream

Canal/Ditch

Pipeline

Surface Water Flow Direction

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

SS

10/7/2021

10/7/2021

NOTES Site Inspection for PFAS at Esler Field, LA

10/7/2021

Figure 2-4 PM CM 10/7/2021

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\LA\Esler_Field\Esler_Field_SI_MXDs\SI_Report\Fig_2-4_Esler_Field_Surfacewater_Features.mxd

12420 Milestone Center Drive

Germantown, MD 20876

Surface Water Features

Base Map: Source: Esri, Maxar, GeoEye, Earthstar

Geographics, CNES/Airbus DS, USDA, USGS,

1:126,720

0 1 2 4

Miles

AECOM 

­

2-8
?!

?!

?!

?!

?!

?!

Sewage Oxidation ?!

Pond

Approximate

Path of Storm

Sewer Pipe

AOI01-01

70.64

AOI02-01

72.91

AOI02-02

72.33

ESLR-01

72.16

AOI03-01

73.04

AOI03-02

71.82

AOI03-03

72.06

Mill Creek

73

72

73

71

72

71

Legend

?! Soil Boring/Temp Monitoring Well Location

Facility Boundary

Water Body

River/Stream

Approximate Path of Storm Sewer Pipe

Groundwater Elevation Contour

Inferred Groundwater Elevation Contour

Groundwater Flow Direction

0 200 400 800

Feet

­ Figure 2-5

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection for PFAS at Esler Field, LA

10/7/2021

10/7/2021

10/7/2021

MS

SS

CM

GIS BY

CHK BY

PM

Base Map: Source: Esri, Maxar, GeoEye, Earthstar Geographics, CNES/Airbus DS,

USDA, USGS, AeroGRID, IGN, and the GIS User Community

10/7/2021

1:4,800

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\LA\Esler_Field\Esler_Field_SI_MXDs\SI_Report\Fig_2-5_Esler_Field_SI_GW_Contours.mxd

Groundwater Elevation Contours

12420 Milestone Center Drive

Germantown, MD 20876

AECOM 2-9
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

THIS PAGE INTENTIONALLY BLANK

AECOM 2-10
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 3-1

3. Summary of Areas of Interest 

This section presents a summary of each potential PFAS release area by AOI. Based on the PA 

findings, six potential PFAS release areas, Sewage Oxidation Pond, North Ramp/Wash Rack, 

Hangar Buildings 6001 and 6002, South Ramp, Firehouse Building 6004, and Storage Building 

6067/6068, were identified at Esler Field AASF and grouped into four AOIs (AECOM, 2020). The 

potential PFAS release areas are shown on Figure 3-1. 

3.1 AOI 1 

AOI 1 consists of one potential PFAS release area. The potential release area is described below. 

3.1.1 Sewage Oxidation Pond

Stormwater is conveyed from various points on the facility to the approximately 1.3-acre square, 

lined, Sewage Oxidation Pond on the southwestern portion of the installation. Between 1996 and 

2007, fire training activities occurred on the North Ramp/Wash Rack and South Ramp in which 

foam was dispensed from Tri-MaxTM carts and was subsequently rinsed down nearby stormwater 

drains (described further in Sections 3.2.1 and 3.3.1). Drains convey stormwater to an oil/water 

separator (OWS) and then to the Sewage Oxidation Pond. LAARNG reports the Sewage 

Oxidation Pond overflows at least once a year, with resulting overflow discharging to surrounding 

surface soil and potentially to Flagon Bayou. The geographic coordinates for the Sewage 

Oxidation Pond are 31° 23'18.34"N; 92°18'15.23"W.

3.2 AOI 2 

AOI 2 consists of two potential PFAS release areas. The potential release areas are described 

below.

3.2.1 North Ramp/Wash Rack

Fire training at the North Ramp/Wash Rack was conducted annually between 1996 and 2007. 

The exact location of the training events held on the ramps varied from year to year. During these 

drills (held jointly with the local Holloway Volunteer Fire Department [VFD]), expired or nearly

expired Tri-MaxTM foam carts were fully expended. After training, the expended carts were 

recharged with 5-gallon buckets stored in the Storage Building (discussed further in Section 

3.4.2). Foam dispensed from Tri-MaxTM carts during training was rinsed from the ramp down into 

a nearby stormwater drain. Drains convey stormwater southwest to an OWS and then to the

Sewage Oxidation Pond located on the southwestern portion of the facility. The geographic 

coordinates for the North Ramp/Wash Rack are 31° 23'27.15"N; 92°17'45.64"W. 

3.2.2 Hangar Buildings 6001 and 6002

Hangar Buildings 6001 (primary hangar built before 1955) and 6002 (built between 1955 and 

1971) are located in close proximity to each other, in the south-central portion of the facility. The 

fire suppression systems in the hangars are water deluge (no foam). Chemguard 3% AFFF is 

stored in each building. No suspected releases or spills of AFFF occurred at these locations

(AECOM, 2020). The geographic coordinates for the hangars are 31° 23'28.67"N; 92°17'46.84"W 

(6001) and 31° 23'30.01"N; 92°17'50.54"W (6002).
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 3-2

3.3 AOI 3 

AOI 3 consists of one potential PFAS release area. The potential release area is described below. 

3.3.1 South Ramp

The South Ramp was constructed in 2005-2006, and fire training was conducted until 2007. The 

exact location of the training events held on the ramp varied from year to year. During these drills 

(held jointly with the local Holloway VFD), expired or nearly expired Tri-MaxTM foam carts were 

fully expended. After training, the expended carts were recharged with 5-gallon buckets stored in 

the Storage Building. Foam dispensed from Tri-MaxTM carts during training was rinsed from the 

ramp down into a nearby stormwater drain. Drains convey stormwater west to an OWS and then 

to the Sewage Oxidation Pond located on the southwestern portion of the facility. The geographic 

coordinates for the South Ramp are 31° 23'24.84"N; 92°17'38.92"W.

3.4 AOI 4 

AOI 4 consists of two potential PFAS release areas. The potential release areas are described 

below. 

3.4.1 Firehouse Building 6004

Firehouse Building 6004 was active from the late 1980s through the 1990s, when Esler Field was 

still Esler Regional Airport. Firehouse Building 6004 was a civilian firehouse run by the Holiday 

Village Fire Department, and AFFF was stored in 5-gallon buckets within the building. The 

firehouse shut down in the late 1990s, and fire response is now currently handled through a 

pre-accident plan with the Holloway VFD. There have been no reported AFFF releases or spill 

incidents at this location (AECOM, 2020). The geographic coordinates for Firehouse Building 

6004 are 31° 23'30.01"N; 92°17'56.20"W.

3.4.2 Storage Building 6067/6068

AFFF was previously stored in a portable building before being moved to the Storage Building 

(6067/6068), located just south of the primary hangar (Hangar 6001). At the time of the PA, three 

containers of Chemguard 3% solution were stored in the building (AECOM, 2020). During training 

from 1996 to 2007, 5-gallon buckets of AFFF were used to recharge the fire extinguisher carts 

located on the North and South Ramps. There have been no reported AFFF releases or spill 

incidents at this location. The geographic coordinates for the Storage Building 6067/6068 are 31° 

23'27.15"N; 92°17'49.38"W.
AOI 4

Sewage Oxidation

Pond

Approximate

Path of Storm

Sewer Pipe

AOI 1

AOI 2

AOI 3

Firehouse

Building 6004

Storage 

Building 6067/6068

North 

Ramp/Wash Rack

South Ramp

Hangar

Building 6002

Hangar

Building 6001

Flagon Bayou

MillCreek

Lower Flagon

Bayou Watershed

CLIENT

REVISED

SCALE

ARNG

GIS BY

CHK BY

MS

SS

4/21/2022

4/21/2022

NOTES Site Inspection for PFAS at Esler Field, LA

1:12,000

4/21/2022 ­ Figure 3-1 PM CM 4/21/2022

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\LA\Esler_Field\Esler_Field_SI_MXDs\SI_Report\Fig_3-1_Esler_Field_AOIs.mxd

12420 Milestone Center Drive

Germantown, MD 20876

Area of Interest

Base Map: Source: Esri, Maxar, GeoEye, Earthstar

Geographics, CNES/Airbus DS, USDA, USGS,

Legend

Area of Interest

Potential PFAS Release

Facility Boundary

Water Body

Wetland

River/Stream

Approximate Path of Storm Sewer Pipe

Surface Water Flow Direction

Groundwater Flow Direction

0 500 1,000 2,000

Feet

AECOM 3-3
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 3-4

THIS PAGE INTENTIONALLY BLANK
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 4-1

4. Project Data Quality Objectives

Project Data Quality Objectives (DQOs) are qualitative and quantitative statements that specify 

the quality of data and define the level of certainty required to support project decision-making

process. The specific DQOs established for this facility are described below. These DQOs were 

developed in accordance with the USEPA’s seven-step iterative process (USEPA, 2006). 

4.1 Problem Statement

The following problem statement was developed during project planning:

The presence of PFAS, which may pose a risk to human health or the environment, in 

environmental media at the facility is currently unknown. PFAS are classified as emerging 

environmental contaminants that are garnering increasing regulatory interest due to their potential 

risks to human health and the environment. The regulatory framework for managing PFAS at both 

the federal and state level continues to evolve. 

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 Office of the Secretary of 

Defense (OSD) dated 15 September 2021 (Assistant Secretary of Defense, 2021). 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 three compounds: PFOS, PFOA, and PFBS. 

The SLs are presented in Section 6.1 of this Report.

The following quotes from the DA policy documents form the basis for this project (DA, 2016; DA, 

2018): 

• “The Army will research and identify locations where PFOS- and/or PFOA-containing 

products, such as AFFF, are known or suspected to have been used. Installations shall 

coordinate with installation/facility fire response or training offices to identify AFFF use or 

storage locations. The Army will consider FTAs, AFFF storage locations, hangars/buildings 

with AFFF suppression systems, fire equipment maintenance areas, and areas where 

emergency response operations required AFFF use as possible source areas. In addition, 

metal plating operations, which used certain PFOS-containing mist suppressants, shall be 

considered possible source areas.” 

• “Based on a review of site records...determine whether a CERCLA PA is appropriate for 

identifying PFOS/PFOA release sites. If the PA determines a PFOS/PFOA release may 

have occurred, a CERCLA SI shall be conducted to determine presence/absence of 

contamination.”

• “Identify sites where perfluorinated compounds are known or suspected to have been 

released, with the priority being those sites within 20 miles of the public systems that tested 

above USEPA HA levels.” (USEPA, 2016a; USEPA, 2016b).

4.2 Goals of the Study

The following goals were established for this SI:

1. Determine the presence or absence of PFOA, PFOS, and PFBS at or above SLs.
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 4-2

2. Develop information to potentially eliminate a release from further consideration because 

it is determined that it poses no significant threat to human health or the environment.

3. Determine the potential need for a Time Critical Removal Action (TCRA) (applies to 

drinking water only). The primary actions that will be considered include provision of 

alternative water supplies or wellhead treatment.

4. Collect data to better characterize the release areas for more effective and rapid initiation 

of an RI (if determined necessary). 

5. If PFOA, PFOS, and PFBS are determined to be present, aim to evaluate whether the 

concentrations can be attributed to on-facility or off-facility sources that were identified 

within 4 miles of the installation as part of the PA (e.g., fire stations, major manufacturers, 

other DoD facilities).

6. Determine whether a potentially complete pathway exists between the source and 

potential receptors and whether ARNG is the likely source of the contamination. 

4.3 Information Inputs

Primary information inputs included:

• The PA for Esler Field AASF (AECOM, 2020); 

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

with the site-specific Uniform Federal Policy (UFP)-Quality Assurance Project Plan (QAPP) 

Addendum (AECOM, 2021a); and

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

parameters measured at the time of sampling. 

4.4 Study Boundaries

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

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

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

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

time that field resources were available to complete the study.

4.5 Analytical Approach

Samples were analyzed by Pace Analytical Gulf Coast, accredited under the 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 and decision rules as defined in the SI QAPP Addendum (AECOM, 

2021a). These rules governed response actions based on the results of the SI sampling effort.

The decision rules described in the Worksheet #11 of the SI QAPP Addendum identify actions 

based on the following:

Groundwater:

• Is there a human receptor within 4 miles of the facility? 

• What is the concentration of PFOA, PFOS, and PFBS at the potential release areas? 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 4-3

• What is the concentration of PFOA, PFOS, and PFBS at the facility boundary upgradient 

and downgradient of the potential release areas? 

• What does the conceptual site model (CSM) suggest in terms of source, pathway and 

receptor? 

Soil:

• What is the concentration of PFOA, PFOS, and PFBS in shallow surface soil (0 to 2 feet 

bgs)? 

• What is the concentration of PFOA, PFOS, and PFBS in deep soil (i.e., capillary fringe)?

• What does the CSM suggest in terms of source, pathway, and receptor? 

Soil and groundwater samples were collected at the potential release areas. Groundwater was 

encountered at approximately 6.12 to 19.93 feet bgs. 

4.6 Data Usability Assessment

The Data Usability Assessment (DUA) is an evaluation at the conclusion of data collection 

activities that uses the results of both data verification and validation in the context of the overall 

project decisions or objectives. Using both quantitative and qualitative methods, the assessment 

determines whether project execution and the resulting data have met installation-specific DQOs. 

Both sampling and analytical activities are considered to assess whether the collected data are 

of the right type, quality, and quantity to support the decision-making (DoD, 2019a; DoD, 2019b; 

USEPA, 2017b). 

Data Quality Indicators (DQIs) (Precision, Accuracy, Representativeness, Comparability, 

Completeness and Sensitivity) are important components in assessing data usability. These DQIs 

were evaluated in the subsequent sections and demonstrate that the data presented in this SI 

report are of high quality. Although the SI data are considered reliable, some degree of uncertainty 

can be associated with the data collected. Specific factors that may contribute to the uncertainty 

of the data evaluation are described below. The Data Validation Report (DVR) (Appendix A) 

presents explanations for all qualified data in greater detail.

4.6.1 Precision

Precision is the degree of agreement among repeated measurements of the same characteristic 

on the same sample or on separate samples collected as close as possible in time and place. 

Field sampling precision is measured with the field duplicate relative percent differences (RPD); 

laboratory precision is measured with calibration verification, internal standard recoveries, 

laboratory control spike (LCS) and matrix spike (MS) duplicate RPD.

Calibration verifications were performed routinely to ensure that instrument responses for all 

calibrated analytes were within established quality control (QC) criteria. No associated calibration 

verifications displayed results outside the project established precision limits presented in the 

QAPP Addendum (AECOM, 2021a). 

LCS/LCS duplicate (LCSD) pairs were prepared by addition of known concentrations of each 

analyte in a matrix-free media known to be free of target analytes. LCS/LCSD pairs were analyzed 

for every analytical batch to demonstrate the ability of the laboratory to detect similar 

concentrations of a known quantity in matrix-free media. The LCS/LCSD samples were within the 

project established precision limits presented in the QAPP Addendum (AECOM, 2021a). 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 4-4

MS/MS duplicate (MSD) samples were prepared, analyzed, and reported for all preparation 

batches. MS/MSD samples demonstrated that the analytical system was in control for the matrix 

being tested. MS/MSD samples were submitted to the laboratory for analysis at a rate of 5%. The 

MS/MSD samples were within the project established precision limits presented in the QAPP 

Addendum (AECOM, 2021a). 

Field duplicate samples were collected at a rate of 10% to assess the overall sampling and 

measurement precision for this sampling effort. The field duplicate samples were analyzed for 

PFAS and general chemistry parameters. The field duplicate samples were within the project 

established precision limits presented in the QAPP Addendum (AECOM, 2021a) with limited 

exceptions. The field duplicate pair performed on sample AOI03-02-SB-9-11 displayed non-detect 

results for PFBS, perfluorohexanoic acid (PFHxA), and perfluorohexanesulfonic acid (PFHxS), 

while the associated field duplicate sample displayed positive results for these analytes. Several 

field duplicate pairs displayed one non-detect result for a compound, while the associated field 

duplicate sample displayed a positive result. The associated field duplicate pair results were 

qualified as estimated and should be considered usable as qualified. The field duplicate pair 

performed on parent sample AOI02-02-SB-0-2 displayed a relative percent difference greater than 

the project established precision limits for total organic carbon (TOC). The associated field 

duplicate pair results were qualified as estimated and should be considered usable as qualified.

4.6.2 Accuracy

Accuracy is a measure of confidence in a measurement. The smaller the difference between the 

measurement of a parameter and its "true" or expected value, the more accurate the 

measurement. The more precise or reproducible the result, the more reliable or accurate the 

result. Accuracy is measured through percent recoveries in the LCS/LCSD, MS/MSD, and 

surrogates.

LCS/LCSD samples were prepared by addition of known concentrations of each analyte in a 

matrix free media known to be free of target analytes. LCS/LCSD samples were analyzed for 

every analytical batch and demonstrated that the analytical system was in control during sample 

preparation and analysis. The LCS/LCSD samples were within the project established accuracy 

limits presented in the QAPP Addendum (AECOM, 2021a), with one exception. One LCS 

displayed a percent recovery greater than the established project precision limit of 129% for 

perfluorobutyrate (PFBA) at 130%. The associated field sample results were all non-detect and 

should be considered usable as reported. 

MS/MSD samples were prepared, analyzed, and reported at a rate of 5%. MS/MSD samples 

demonstrated that the analytical system was in control for the matrix being tested. The MS/MSD 

samples were within the project established control limits presented in the QAPP Addendum 

(AECOM, 2021a).

Extraction internal standards (EIS) were added by the laboratory during sample extraction to 

measure relative responses of target analytes and used to correct for bias associated with matrix 

interferences and sample preparation efficiencies, injection volume variances, mass spectrometry 

ionization efficiencies, and other associated preparation and analytical anomalies. Field sample 

AOI01-01-GW displayed an EIS area count for M2 sodium 1 H, 1 H,2H,2H-perfluoro-1-[1 ,2- 13C2]octanesulfonate (6:2 FTS) greater than the project established precision limits presented in 

the QAPP Addendum (AECOM, 2021a). The associated field sample result was non-detect and 

should be considered usable as reported. 

Injection internal standards (IIS) were added by the laboratory after sample extraction and prior 

to analysis as a legacy requirement of DoD QSM 5.1 to measure relative responses of target 

analytes. Even though not required under the current DoD QSM 5.3 analysis, the IIS are still 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 4-5

added to the sample after extraction as an additional QC measure. The IIS percent recoveries 

were within the established precision limits presented in the QAPP Addendum (AECOM, 2021a). 

4.6.3 Representativeness

Representativeness qualitatively expresses the degree to which data accurately reflect site 

conditions. Factors that affect the representativeness of analytical data include appropriate 

sample population definitions, proper sample collection and preservation techniques, analytical 

holding times, use of standard analytical methods, and determination of matrix or analyte 

interferences. 

Relating to the use of standard analytical methods, the laboratory followed the method as 

established in PFAS by LC/MS/MS Compliant with QSM Table B-15, including the specific 

preparation requirements (i.e., ENVI-Carb or equivalent used), mass calibration, spectra, all the 

ion transitions identified in Table B-15 were monitored, standards that contained both branched

and linear isomers when available were used, and isotopically labeled standards were used for

quantitation.

Field QC samples were collected to assess the representativeness of the data collected. Field 

duplicates were collected at a rate of 10% for all field samples, while MS/MSD samples were 

collected at a rate of 5%. The laboratory used approved standard methods in accordance with the 

QAPP Addendum (AECOM, 2021a) for all analyses. All technical and analytical holding times 

were met by the laboratory for the initial results with limited exceptions. The holding time for pH 

analysis is considered ‘immediate’, so all pH sample results have been qualified as estimated. 

Instrument blanks and method blanks were prepared by the laboratory in each batch as a negative 

control. Three PFAS instrument blanks and one method blank displayed target analyte 

concentrations greater than the detection limit (DL) for N-methyl 

perfluorooctanesulfonamidoacetic acid (NMeFOSAA) and N-ethyl 

perfluorooctanesulfonamidoacetic acid (NEtFOSAA). The associated field sample results were 

either non-detect or displayed concentrations greater than five times the blank detections and 

should be considered usable as reported. 

Field blanks and equipment blanks were also collected for groundwater and soil samples. The 

blank sample results were non-detect and should be considered usable as reported.

A sample of the water used for decontamination of the drill rig was collected in advance of the 

field effort. The sample results were non-detect and should be considered usable as reported. 

Overall, the data are usable for evaluating the presence or absence of PFAS at the facility. 

Sufficient usable data were obtained to meet the objectives of the SI.

4.6.4 Comparability

Comparability is the extent to which data from one study can be compared directly to either past 

data from the current project or data from another study. Using standardized sampling and 

analytical methods, units of reporting, and site selection procedures help ensure comparability. 

Standard field sampling and typical laboratory protocols were used during the SI and are 

considered comparable to ongoing investigations.

4.6.5 Completeness

Completeness is a measure of the amount of valid data obtained from a measurement system 

compared to the amount of data expected under normal conditions. The laboratory provided data 

meeting system QC acceptance criteria for all samples tested. Project completeness was 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 4-6

determined by evaluating the planned versus actual quantities of data. Percent completeness per 

parameter is as follows and reflects the exclusion of “X/UX” flagged data, if applicable: 

• PFAS in aqueous media by DoD QSM Table B-15 at 100% 

• PFAS in solid media by DoD QSM Table B-15 at 100% 

• pH in soil by USEPA Method 9045D at 100%

• TOC by USEPA Method 9060 at 100%

4.6.6 Sensitivity

Sensitivity is the capability of a test method or instrument to discriminate between measurement 

responses representing different levels (e.g., concentrations) of a variable of interest. Examples 

of QC measures for determining sensitivity include laboratory fortified blanks, an MDL study, and 

calibration standards at the limit of quantitation (LOQ). In order to meet the needs of the data 

users, project data must meet the measurement performance criteria for sensitivity and project 

LOQs specified in the QAPP Addendum (AECOM, 2021a). The laboratory provided the requested 

MDL studies and provided applicable calibration standards at the LOQ. In order to achieve the 

DQOs for sensitivity outlined in the QAPP Addendum (AECOM, 2021a), the laboratory reported 

all field sample results at the lowest possible dilution. Additionally, any analytes detected below 

the LOQ and above the DL were reported and qualified “J” as estimated values by the laboratory.
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

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 Preliminary Assessment Report, Esler Field Army Aviation Support Facility, Louisiana

dated July 2020 (AECOM, 2020); 

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

dated March 2018 (AECOM, 2018a); 

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

Esler Field Army Aviation Support Facility, Louisiana dated July 2021 (AECOM, 2021a); 

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

• Final Site Safety and Health Plan, Esler Field Army Aviation Support Facility, Louisiana

dated July 2021 (AECOM, 2021b). 

The SI field activities were conducted from 26 July to 3 August 2021 and consisted of utility 

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

groundwater sample collection, and land surveying. Field activities were conducted in accordance 

with the SI QAPP Addendum (AECOM, 2021a). 

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

LC/MS/MS compliant with QSM 5.3 Table B-15 to fulfill the project DQOs:

• Thirty (30) soil samples from 16 boring locations; 

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

• Fourteen (14) quality assurance (QA)/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, and land survey data are 

provided in Appendix B3. Additionally, a photographic log of field activities is provided in 

Appendix C. 

5.1 Pre-Investigation Activities

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

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

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

5.1.1 Technical Project Planning

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

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

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

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

quantitative and qualitative DQOs, and formulating a sampling approach to address the AOIs 

identified in the PA. 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 5-2

A combined TPP Meeting 1 and 2 was held on 26 May 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, LAARNG, USACE, Louisiana Department of

Environmental Quality, and representatives familiar with the facility, the regulations, and the 

community. Stakeholders were provided the opportunity to make comments on the technical 

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

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

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

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

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

5.1.2 Utility Clearance

AECOM’s drilling subcontractor, Tolunay-Wong Engineers, Inc. placed a ticket with the Louisiana 

811 utility clearance provider to notify them of intrusive work on 14 July 2021. However, because 

the AASF is a private facility, the participating Louisiana 811 locators did not clear utilities at the 

entire facility. Therefore, AECOM contracted Ground Penetrating Radar Systems, LLC. (GPRS), 

a private utility location service, to perform utility clearance. GPRS performed utility clearance of 

the proposed boring locations on 22 July 2021 with input from the AECOM field team and Esler 

Field AASF facility staff. General locating services and ground-penetrating radar were used to 

complete the clearance. Additionally, the first 5 feet of each boring were pre-cleared using a hand 

auger to verify utility clearance in the shallow subsurface where utilities would typically be 

encountered. 

5.1.3 Source Water and PFAS Sampling Equipment Acceptability

The potable water source used for decontamination of drilling equipment was confirmed to be 

acceptable for use in a PFAS investigation prior to the start of field activities. A sample from a 

potable water source at Esler Field AASF was collected on 17 June 2021, prior to mobilization, 

and analyzed for PFAS by liquid chromatography with tandem mass spectrometry (LC/MS/MS) 

compliant with Quality Systems Manual (QSM) 5.3 Table B-15. The results of the decontamination 

water sample are provided in Appendix F. A discussion of the results is presented in Section 

4.6.3. Other non-dedicated sampling equipment was decontaminated using PFAS-free American 

Society of Testing and Materials (ASTM) Type II deionized water and AlconoxTM.

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

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

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

QAPP Addendum (AECOM, 2021a). Prior to the start of field work each day, a PFAS 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 DPT, in accordance with the SI QAPP Addendum (AECOM, 

2021a). A GeoProbe® 7822DT Macro-Core® soil sampling system was used to collect continuous 

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

boring, in accordance with AECOM utility clearance procedures. The soil boring locations are 

shown on Figure 5-1 and depths are provided Table 5-2. Borings were installed in grass areas 

to avoid disturbing concrete or asphalt surfaces.

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 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 5-3

2 feet above the groundwater table, and one subsurface soil sample at the mid-point between the 

surface and the groundwater table. 

The soil cores were continuously logged for lithological descriptions by a field geologist using the 

Unified Soil Classification System (USCS). A photoionization detector (PID) was used to screen 

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

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

Soil borings completed during the SI were drilled to depths between 20 and 45 feet bgs. Generally, 

the subsurface soil can be characterized by thick layers (10 to 26 feet) of fine-grained sediments, 

characterized as clay-rich silt to silt-rich clay overlying sand-rich lenses. These sand lenses are 

characterized as poorly graded sand (<15% fines) to silty/clayey sand (>15% fines) and range 

from 0.5 to 6 feet in thickness. The sand lenses are interbedded with clay and silt dominated 

lenses, often grading from poorly graded sand to silty/clayey sand to sandy clay/silt to clay/silt, 

and vice versa. These facility observations are consistent with the fluviatile silts and sands of the 

Dough Hills Member. Each soil sample was collected into laboratory-supplied PFAS-free highdensity 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 for PFAS (LC/MS/MS compliant with QSM 5.3

Table B-15), TOC (USEPA Method 9060A) and pH (USEPA Method 9045D) and grain size (ASTM 

Method D-422) in accordance with the SI QAPP Addendum (AECOM, 2021a). 

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. In instances when non-dedicated sampling 

equipment was used, such as a hand auger for the shallow soil samples, equipment rinsate blanks

were collected at a rate of 5% and analyzed for the same parameters as the soil samples. A 

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

6 degrees Celsius (°C) during shipment.

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

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

of sampling activities. 

5.3 Temporary Well Installation and Groundwater Grab Sampling

DPT borings were converted to temporary wells. Once the borehole was advanced to the desired 

depth, a temporary well was constructed of a 5 to 10-foot section of 1-inch Schedule 40 poly-vinyl 

chloride (PVC) screen with sufficient casing to reach ground surface. New PVC pipe and screen 

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

wells are provided in Table 5-2. 

The temporary wells were allowed to recharge after installation and before collection of 

groundwater samples. After the recharge period, groundwater samples were collected using 

either a peristaltic pump or a bladder pump with PFAS-free HDPE tubing. Each sample was 

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

or pen. 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) after each grab sample was 

collected. Additionally, a subsample of each groundwater sample was collected in a separate 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 5-4

container, and a shaker test was completed to identify if there was any foaming. No foaming was 

noted in any of the groundwater samples. 

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

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

FedEx under standard CoC procedures to the laboratory and analyzed for PFAS by LC/MS/MS 

compliant with QSM 5.3 Table B-15 in accordance with the SI QAPP Addendum (AECOM, 2021a). 

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, 2021a) 

by removing the PVC and backfilling the hole with bentonite chips. 

5.4 Synoptic Water Level Measurements

A synoptic groundwater gauging event was performed on 3 August 2021. Groundwater elevation 

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

measurements were taken from the northern side of the well casing. A groundwater flow contour 

map is provided in Figure 2-5. Groundwater elevation data is provided in Table 5-2. 

5.5 Surveying 

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

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

Survey data from the newly installed temporary wells were collected on 3 August 2021 in the 

applicable Universal Transverse Mercator zone projection with North American Datum 1983 

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

provided in Appendix B3. 

5.6 Investigation-Derived Waste

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

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

was managed in accordance with the SI QAPP Addendum (AECOM, 2019b) and with the DA

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

Solid (i.e., soil cuttings) and liquid (i.e., purge water and decontamination fluids) generated during 

SI activities were containerized in properly labeled and covered 5-gallon buckets. The IDW was 

stored at a secure and covered location designated by the Esler Field AASF Environmental 

Manager and LAARNG, pending the receipt of sample results. Solid and liquid IDW will be 

transferred to DOT-approved 55-gallon steel drums prior to disposal. The solid and liquid IDW will 

be disposed of via a RCRA Subtitle C landfill. The disposal contract is being managed under a 

separate contract (EA Engineering, Science, and Technology, Inc., 2021). Specifics on the 

disposal of solid and liquid IDW will be addressed in an IDW Treatment Memorandum.

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.
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 5-5

5.7 Laboratory Analytical Methods

Samples were analyzed for a subset of 18 PFAS 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. The 18 PFAS analyzed as part of the ARNG SI program include the following: 

• 6:2 fluorotelomer sulfonic acid (6:2 FTS)

• 8:2 fluorotelomer sulfonic acid (8:2 FTS)

• N-ethyl perfluorooctanesulfonamidoacetic 

acid (NEtFOSAA)

• N-methyl 

perfluorooctanesulfonamidoacetic acid 

(NMeFOSAA) 

• Perfluorobutyrate (PFBA) 

• Perfluorobutanesulfonic acid (PFBS)

• Perfluorodecanoic acid (PFDA)

• Perfluorododecanoic acid (PFDoA)

• Perfluoroheptanoic acid (PFHpA)

• Perfluorohexanoic acid (PFHxA)

• Perfluorohexanesulfonic acid (PFHxS)

• Perfluorononanoic acid (PFNA)

• Perfluorooctanoic acid (PFOA) 

• Perfluorooctanesulfonic acid (PFOS)

• Perfluoropentanoic acid (PFPeA)

• Perfluorotetradecanoic acid (PFTeDA)

• Perfluorotridecanoic acid (PFTrDA)

• Perfluoroundecanoic acid (PFUdA)

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

9045D, and grain size analysis by ASTM Method D-422. 

5.8 Deviations from SI QAPP Addendum

One deviation from the SI QAPP Addendum has resulted from a change in the soil and 

groundwater SLs for PFBS in the OSD Memo (dated 15 September 2021), which was issued after 

the submittal of the Final SI QAPP. The revised SLs were developed using the USEPA Regional 

Screening Levels Calculator and are considered valid toxicity-based values after peer review 

(Assistant Secretary of Defense, 2021).
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 5-6

THIS PAGE INTENTIONALLY BLANK
Table 5-1

Site Inspection Samples by Medium

Site Inspection Report, Esler Field AASF, Louisiana

Sample Identification

Sample

Collection 

Date/Time

Sample Depth 

(feet bgs)

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

Comments

AOI01-01-SB-00-02 7/28/2021 12:00 0 - 2 x x x

AOI01-01-SB-00-02-MS 7/28/2021 12:00 0 - 2 x MS

AOI01-01-SB-00-02-MSD 7/28/2021 12:00 0 - 2 x MSD

AOI01-01-SB-04-06 8/3/2021 12:35 4 - 6 x

AOI01-01-SB-09-11 7/28/2021 12:30 9 - 11 x

AOI01-01-SB-12-14 7/28/2021 12:40 12 - 14 x

AOI01-01-SB-12-14-D 7/28/2021 12:40 12 - 14 x FD

AOI01-02-SB-00-02 7/28/2021 15:45 0 - 2 x

AOI01-03-SB-00-02 7/28/2021 16:15 0 - 2 x

AOI01-04-SB-00-02 7/28/2021 16:05 0 - 2 x

AOI02-01-SB-0-2 7/27/2021 7:50 0 - 2 x

AOI02-01-SB-0-2-D 7/27/2021 7:50 0 - 2 x FD

AOI02-01-SB-07-09 8/3/2021 12:40 7 - 9 x

AOI02-01-SB-11-13 7/27/2021 8:42 11 - 13 x

AOI02-01-SB-20-22 7/27/2021 9:18 20 - 22 x

AOI02-02-SB-0-2 7/26/2021 14:10 0 - 2 x x x

AOI02-02-SB-0-2-D 7/26/2021 14:10 0 - 2 x x FD

AOI02-02-SB-11-13 7/26/2021 14:30 11 - 13 x

AOI02-02-SB-27-29 7/27/2021 10:17 27 - 29 x

AOI02-03-SB-00-02 7/28/2021 14:10 0 - 2 x

AOI03-01-SB-0-2 7/27/2021 11:36 0 - 2 x

AOI03-01-SB-13-15 7/27/2021 11:57 13 - 15 x

AOI03-01-SB-26-28 7/28/2021 13:10 26 - 28 x

AOI03-02-SB-0-2 7/26/2021 11:48 0 - 2 x x x

AOI03-02-SB-0-2-MS 7/26/2021 11:48 0 - 2 x x MS

AOI03-02-SB-0-2-MSD 7/26/2021 11:48 0 - 2 x x MSD

AOI03-02-SB-9-11 7/26/2021 12:06 9 - 11 x

AOI03-02-SB-9-11-D 7/26/2021 12:06 9 - 11 x FD

AOI03-02-SB-15-17 7/26/2021 12:20 15 - 17 x

AOI03-03-SB-0-2 7/28/2021 9:33 0 - 2 x

AOI03-03-SB-09-11 7/28/2021 9:56 9 - 11 x

AOI03-03-SB-12-14 8/3/2021 12:45 12 - 14 x

AOI03-03-SB-14-16 7/28/2021 10:02 14 - 16 x

AOI03-04-SB-00-02 7/28/2021 14:55 0 - 2 x

AOI03-05-SB-00-02 7/28/2021 14:35 0 - 2 x

AOI03-06-SB-00-02 7/28/2021 9:25 0 - 2 x

AOI04-01-SB-00-02 7/28/2021 15:10 0 - 2 x

AOI04-02-SB-00-02 7/28/2021 15:25 0 - 2 x

ESLR-01-SB-0-2 7/26/2021 9:47 0 - 2 x

ESLR-01-SB-0-2-MS 7/26/2021 9:47 0 - 2 x MS

ESLR-01-SB-0-2-MSD 7/26/2021 9:47 0 - 2 x MSD

ESLR-01-SB-11-13 7/26/2021 10:12 11 - 13 x x x

ESLR-01-SB-13-15 7/26/2021 10:20 13 - 15 x

ESLR-01-SB-20-22 7/26/2021 10:34 20 - 22 x

Soil Samples

AECOM 5-7
Table 5-1

Site Inspection Samples by Medium

Site Inspection Report, Esler Field AASF, Louisiana

Sample Identification

Sample

Collection 

Date/Time

Sample Depth 

(feet bgs)

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

Comments

AOI01-01-GW 7/28/2021 16:20 NA x

AOI02-01-GW 7/27/2021 11:00 NA x

AOI02-01-GW-D 7/27/2021 11:00 NA x FD

AOI02-01-GW-MS 7/27/2021 11:00 NA x MS

AOI02-01-GW-MSD 7/27/2021 11:00 NA x MSD

AOI02-02-GW 7/27/2021 12:56 NA x

AOI03-01-GW 7/28/2021 11:52 NA x

AOI03-02-GW 7/26/2021 15:35 NA x

AOI03-03-GW 7/28/2021 14:15 NA x

ESLR-01-GW 7/26/2021 13:28 NA x

ESLR-FRB-01 7/27/2021 8:15 NA x

ESLR-ERB-01 7/26/2021 11:40 NA x from hand auger

ESLR-ERB-02 7/27/2021 7:10 NA x from DPT shoe

Notes:

ASTM = American Society for Testing and Materials

bgs = below ground surface

ERB = equipment rinsate blank

FD = field duplicate

FRB = field reagent blank

LC/MS/MS = Liquid Chromatography Mass Spectrometry

MS/MSD = matrix spike/ matrix spike duplicate

PFAS = per- and polyfluoroalkyl substances

QSM = Quality Systems Manual

TOC = total organic carbon

USEPA = United States Environmental Protection Agency

Quality Control Samples

Groundwater Samples

AECOM 5-8
Table 5-2

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

Site Inspection Report, Esler Field AASF

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)

Depth to 

Water

(feet bgs)

Groundwater 

Elevation

(feet NAVD88)

1 AOI01-01 20 15 - 20 80.37 79.76 9.73 9.12 70.64

AOI02-01 25 20 - 25 93.03 92.61 20.12 19.70 72.91

AOI02-02 35 30 - 35 92.76 92.08 20.43 19.76 72.33

AOI03-01 45 25 - 35 93.66 92.97 20.62 19.93 73.04

AOI03-02 20 15 - 20 90.26 89.79 18.44 17.98 71.82

AOI03-03 20 15 - 20 80.03 78.18 7.97 6.12 72.06

Sitewide ESLR-01 25 20 - 25 90.60 90.11 18.44 17.95 72.16

Notes:

bgs = below ground surface

btoc = below top of casing

NA = not applicable

NAVD88 = North American Vertical Datum 1988

2

3

AECOM 5-9
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 5-10

1044

1045 THIS PAGE INTENTIONALLY BLANK
"S

"S

"S

?!

?!

?!

?!

"S

?!

?!

?!

"S

"S

"S

"S

"S

AOI 4

Sewage Oxidation

Pond

Approximate

Path of Storm

Sewer Pipe

AOI 1

AOI 2

AOI 3

Mill Creek

AOI01-04

AOI01-02

AOI01-03 AOI01-01

AOI02-01

AOI02-02

ESLR-01

AOI02-03

AOI03-01

AOI03-02

AOI03-03

AOI03-04

AOI03-05

AOI03-06

AOI04-01

AOI04-02

Legend

?! Soil Boring/Temp Monitoring Well Location

"S Surface Soil Sample Location

Area of Interest

Facility Boundary

Water Body

River/Stream

Groundwater Flow Direction

Approximate Path of Storm Sewer Pipe

0 200 400 800

Feet

­ Figure 5-1

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection for PFAS at Esler Field, LA

4/21/2022

4/21/2022

4/21/2022

MS

SS

CM

GIS BY

CHK BY

PM

Base Map: Source: Esri, Maxar, GeoEye, Earthstar Geographics, CNES/Airbus DS,

USDA, USGS, AeroGRID, IGN, and the GIS User Community

4/21/2022

1:4,800

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\LA\Esler_Field\Esler_Field_SI_MXDs\SI_Report\Fig_5-1_Esler_Field_SI_Sample_Locations.mxd

Site Inspection Sample Locations

12420 Milestone Center Drive

Germantown, MD 20876

AECOM 5-11
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

THIS PAGE INTENTIONALLY BLANK

AECOM 5-12
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

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 6.7. Table 6-2 through Table 6-4 present PFAS results for samples with 

detections in soil or groundwater; only constituents detected in one or more samples are included.

Tables that contain all results are provided in Appendix F, and the laboratory reports are provided 

in Appendix G. 

6.1 Screening Levels 

The 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 15 September 

2021 (Assistant Secretary of Defense, 2021). 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 three compounds: 

PFOS, PFOA, and PFBS. 

The SLs are presented on Table 6-1 below. All other results presented in this report are 

considered informational in nature and serve as an indication as to whether soil and groundwater

contain or do not contain PFAS within the boundaries of the facility. 

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

Analyte

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 130 1,600 40

PFOS 130 1,600 40

PFBS 1,900 25,000 600

Notes:

a.) Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS, PFOA, PFBS in Groundwater and Soil using 

United States Environmental Protection Agency’s (USEPA’s) Regional Screening Level Calculator. Hazard Quotient (HQ) = 0.1. 

15 September 2021. 

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

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

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

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

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. 

6.2 Soil Physicochemical Analyses

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

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

the results of the TOC and pH and grain size sampling. 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 6-2

The data collected in this investigation will be used in subsequent investigations, where 

appropriate, to assess fate and transport of PFAS contaminants. According to the Interstate 

Technology Regulatory Council (ITRC), several important PFAS partitioning mechanisms include 

hydrophobic and lipophobic effects, electrostatic interactions, and interfacial behaviors. At 

relevant environmental pH values, certain PFAS are present as organic anions and are therefore 

relatively mobile in groundwater (Xiao et al., 2015), but tend to associate with the organic carbon 

fraction that may be present in soil or sediment (Higgins and Luthy 2006; Guelfo and Higgins, 

2013). When sufficient organic carbon is present, organic carbon normalized distribution 

coefficients (Koc values) can help in evaluating transport potential, though other geochemical 

factors (for example, pH and presence of polyvalent cations) may also affect PFAS sorption to 

solid phases (ITRC, 2018). 

6.3 AOI 1 

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

AOI 1, which includes one potential PFAS release area: Sewage Oxidation Pond. The detected 

compounds in soil and groundwater are summarized on Table 6-2 through Table 6-4. The 

detections of PFOA, PFOS, and PFBS in soil and groundwater are presented on Figure 6-1

through Figure 6-4. 

6.3.1 AOI 1 Soil Analytical Results

PFOA, PFOS, and PFBS did not exceed the SLs in soil at the potential PFAS release area:

Sewage Oxidation Pond. Figure 6-1 through Figure 6-3 present the ranges of detections of

PFOA, PFOS, and PFBS in soil. Table 6-2 and Table 6-3 summarize the detected compounds in 

soil. 

At the Sewage Oxidation Pond, soil was sampled from surface soil (0 to 2 feet bgs) and shallow 

subsurface soil (9 to 11 and 12 to 14 feet bgs) from boring location AOI01-01. Soil was also 

sampled from the surface soil (0 to 2 feet bgs) at locations AOI01-02, AOI01-03, and AOI01-04. 

PFOA, PFOS, and PFBS were detected in soil, at concentrations several orders of magnitude 

lower than the SLs. In the surface soil, PFOA was only detected at location AOI01-04, with a 

concentration of 0.659 J micrograms per kilogram (μg/kg). PFOS was detected at locations

AOI01-03 and AOI01-04, at concentrations of 0.345 J μg/kg and 0.669 J μg/kg, respectively. PFBS 

was only detected at location AOI01-04, with a concentration of 0.035 J μg/kg. PFOA, PFOS, and 

PFBS were not detected in surface soil at locations AOI01-01 and AOI01-02, which are both 

located on the eastern side of the Sewage Oxidation Pond.

In the shallow subsurface soil, PFOS was detected in the soil sample collected at 9 to 11 feet bgs, 

at levels several orders of magnitude below the SL, with a concentration of 0.288 J μg/kg. PFOA 

and PFBS were not detected in this sample. PFOA, PFOS, and PFBS were not detected in the 

second shallow subsurface sample collected at 12 to 14 feet bgs.

6.3.2 AOI 1 Groundwater Analytical Results

PFOA, PFOS, and PFBS were detected in groundwater below the SLs at potential PFAS release 

area, AOI 1: Sewage Oxidation Pond. Figure 6-4 present the ranges of detections of PFOA, 

PFOS, and PFBS in groundwater. Table 6-4 summarizes the detected compounds in 

groundwater. 

Within the Sewage Oxidation Pond potential PFAS release area, groundwater was sampled from 

temporary monitoring well location AOI01-01. PFOA and PFOS were detected below the 

individual SLs of 40 nanograms per liter (ng/L), at concentrations of 5.13 ng/L and 0.810 J ng/L, 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 6-3

respectively. PFBS was detected at several orders of magnitude below the SL of 600 ng/L, at a 

concentration of 0.856 J ng/L. 

6.3.3 AOI 1 Conclusions

Based on the results of the SI, PFOA, PFOS, and PFBS were detected in soil at AOI 1; however, 

the detected concentrations were several orders of magnitude lower than the soil SLs. PFOA, 

PFOS, and PFBS were detected in groundwater at concentrations below the SLs. Based on these 

data, further evaluation at AOI 1 is not warranted. 

6.4 AOI 2 

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

2, which includes two potential PFAS release areas: North Ramp/Wash Rack and Hangar 

Buildings 6001 and 6002. The detected compounds in soil and groundwater are summarized on 

Table 6-2 through Table 6-4. The detections of PFOA, PFOS, and PFBS in soil and groundwater 

are presented on Figure 6-1 through Figure 6-4. 

6.4.1 AOI 2 Soil Analytical Results

PFOA, PFOS, and PFBS did not exceed the SLs in soil at the two potential PFAS release areas:

North Ramp/Wash Rack and Hangar Buildings 6001 and 6002. Figure 6-1 through Figure 6-3

present the ranges of detections of PFOA, PFOS, and PFBS in soil. Table 6-2 and Table 6-3

summarize the detected compounds in soil. 

At the North Ramp/Wash Rack, soil was sampled from surface soil (0 to 2 feet bgs), shallow 

subsurface soil (11 to 13 feet bgs), and deep subsurface soil (27 to 29 feet bgs) from boring 

locations AOI02-02. Soil was also sampled from the surface interval (0 to 2 feet bgs) at location 

AOI02-03. PFOS and PFBS were detected in soil at concentrations several orders of magnitude 

lower than the SLs. In the surface interval, PFOS was only detected at AOI02-02 with a 

concentration of 0.069 J μg/kg. PFOA and PFBS were not detected in either location. In the 

shallow subsurface soil, PFBS was detected at a concentration of 0.035 J μg/kg. PFOA and PFOS 

were not detected in the shallow subsurface interval. In the deep subsurface soil, PFOA, PFOS, 

and PFBS were not detected.

At Hangar Buildings 6001 and 6002, soil was sampled from the surface soil (0 to 2 feet bgs), 

shallow subsurface soil (11 to 13 feet bgs), and deep subsurface soil (20 to 22 feet bgs) at location 

AOI02-01. In surface soil, PFOS was detected at concentrations ranging from 0.168 J μg/kg to 

0.221 J μg/kg, which are several orders of magnitude lower than the SL. PFOA and PFBS were 

not detected in the surface soil interval. In the shallow and deep subsurface soil samples, PFOA, 

PFOS, and PFBS were not detected.

6.4.2 AOI 2 Groundwater Analytical Results

Within the Hangar Buildings 6001 and 6002 potential PFAS release area, groundwater was 

sampled from temporary monitoring well location AOI02-01, whereas at the North Ramp/Wash 

Rack potential PFAS release area, groundwater was sampled from temporary monitoring well 

location AOI02-02. PFOA, PFOS, and PFBS were not detected in groundwater at either of the 

two potential PFAS release areas. Figure 6-4 present the ranges of detections for PFOA, PFOS, 

and PFBS in groundwater. Table 6-4 summarizes the detected compounds in groundwater. 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 6-4

6.4.3 AOI 2 Conclusions

Based on the results of the SI, PFOS and PFBS were detected in soil at AOI 2; however, the 

detected concentrations were several orders of magnitude lower than the soil SLs. PFOA, PFOS, 

and PFBS were not detected in groundwater at either potential PFAS release areas. Based on 

these data, further evaluation at AOI 2 is not warranted. 

6.5 AOI 3 

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

3, which includes the South Ramp potential PFAS release area. The detected compounds in soil

and groundwater are presented in Table 6-2 through Table 6-4. The detections of PFOA, PFOS, 

and PFBS in soil and groundwater are presented on Figure 6-1 through Figure 6-4. 

6.5.1 AOI 3 Soil Analytical Results

PFOA, PFOS, and PFBS in soil did not exceed the SLs in soil at the potential PFAS release area 

in AOI 3. Figure 6-1 through Figure 6-3 present the ranges of detections of PFOA, PFOS, and 

PFBS in soil. Table 6-2 and Table 6-3 summarize the detected compounds in soil. 

At the South Ramp, soil was sampled from the surface soil (0 to 2 feet bgs), shallow subsurface 

soil (13 to 15 feet bgs), and deep subsurface soil (26 to 28 feet bgs) intervals at AOI03-01. Soil 

was also sampled from (0 to 2 feet bgs), shallow subsurface soil (9 to 11 feet bgs), and deep 

subsurface soil (15 to 17 feet bgs) intervals at AOI03-02. AOI03-03 was sampled from the surface 

soil (0-2 feet bgs), shallow subsurface soil (9 to 11 feet bgs), and deep subsurface soil (14 to 16

feet bgs) intervals. Lastly, surface soil (0 to 2 feet bgs) was sampled at AOI03-04 through AOI03-

06.

PFOS and PFBS were detected at concentrations several orders of magnitude lower than the 

SLs. In surface soil, PFOS was only detected at AOI03-02, with a concentration of 0.164 J μg/kg. 

PFBS was only detected at AOI03-04, with a concentration of 0.027 J μg/kg. PFOA was not 

detected in any of the six surface soil samples. In the shallow subsurface soil interval, PFOS and 

PFBS were only detected at AOI03-02 from 9 to 11 feet bgs. PFOS concentrations ranged from 

0.077 J μg/kg to 0.137 J μg/kg and PFBS ranged from non-detect to 0.023 J μg/kg, respectively. 

PFOA was not detected in any of the three shallow subsurface soil samples. In the deep 

subsurface soil interval, PFOA, PFOS, and PFBS were not detected in any of the six samples.

6.5.2 AOI 3 Groundwater Analytical Results 

PFOS and PFBS were detected in groundwater from temporary monitoring wells below the SLs 

at the South Ramp potential PFAS release area, in AOI 3. Figure 6-4 present the ranges of 

detections for PFOA, PFOS, and PFBS in groundwater. Table 6-4 summarizes the detected 

compounds in groundwater. 

At the South Ramp, groundwater was sampled from temporary monitoring well locations AOI03-

01, AOI03-02, and AOI03-03. PFOS was detected in temporary well locations AOI03-02 and 

AOI03-03 below the SL of 40 ng/L, at concentrations of 1.41 J ng/L and 1.09 J ng/L, respectively, 

with the maximum concentration occurring at AOI03-02. PFBS was detected below the SL of 600 

ng/L at only one temporary well, with a concentration of 7.57 ng/L detected at AOI03-03. PFOA 

was not detected in any of the three temporary wells. Temporary well AOI03-01 is located on the 

western side of the South Ramp and did not have detections of PFOA, PFOS, or PFBS.
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 6-5

6.5.3 AOI 3 Conclusions

Based on the results of the SI, PFOS and PFBS were detected in soil at AOI 3; however, the 

detected concentrations were several orders of magnitude lower than the soil SLs. Detections in 

soil only occurred at AOI03-02 and AOI03-04, which are located to the northwest and east of the 

South Ramp, respectively. PFOS and PFBS were detected in groundwater at concentrations 

below the SLs. Based on these data, further evaluation at AOI 3 is not warranted.

6.6 AOI 4 

This section presents the analytical results for soil in comparison to SLs for AOI 4, which includes 

two potential PFAS release areas: Firehouse Building 6004 and Storage Building 6067/6068. The 

detected compounds in surface soil are summarized on Table 6-2. The detections of PFOA, 

PFOS, and PFBS at AOI 4 in soil are presented on Figure 6-1 through Figure 6-3. 

6.6.1 AOI 4 Soil Analytical Results

PFOA, PFOS, and PFBS did not exceed the SLs at the two release areas at AOI 4. Figure 6-1

through Figure 6-3 present the ranges of detections of PFOA, PFOS, and PFBS in soil. Table 6-2 

summarizes the detected compounds in surface soil. 

Soil was sampled from the surface soil interval (0 to 2 feet bgs) at locations AOI04-01 and 

AOI04-02. Location AOI04-01 was sampled at the southeast corner of the Storage Building 

6067/6068, while AOI04-02 was sampled at the southeast corner of the Firehouse Building 6004. 

At the Storage Building 6067/6068, PFOA, PFOS, and PFBS were not detected in surface soil. 

At location AOI04-02 at Firehouse Building 6004, PFOA and PFOS were detected at 

concentrations below the individual SLs of 130 μg/kg, with levels of 0.154 J μg/kg and 15.0 μg/kg, 

respectively. PFBS was not detected at the Firehouse Building 6004.

6.6.2 AOI 4 Conclusions

Based on the results of the SI, PFOA and PFOS were detected in soil at AOI 4: Firehouse Building 

6004; however, the detected concentrations were below the soil SLs. Therefore, further evaluation 

at AOI 4 is not warranted.

6.7 Sitewide

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

upgradient boring and temporary well location ESLR-01. The detected compounds in soil and 

groundwater are summarized on Table 6-2 through Table 6-4. The detections of PFOA, PFOS, 

and PFBS in soil and groundwater are presented on Figure 6-1 through Figure 6-4. 

6.7.1 Sitewide Soil Analytical Results

Soil was sampled from the surface soil (0 to 2 feet bgs), shallow subsurface soil (11 to 13 feet 

bgs), and deep subsurface soil (20 to 22 feet bgs) intervals at boring location ESLR-01. PFOA, 

PFOS, and PFBS were not detected in any of the soil intervals. Figure 6-1 through Figure 6-3

present the ranges of detections of PFOA, PFOS, and PFBS in soil. Table 6-2 and Table 6-3

summarize the detected compounds in soil. 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 6-6

6.7.2 Sitewide Groundwater Analytical Results

One groundwater sample was collected from temporary monitoring well ESLR-01. PFBS was 

detected at levels orders of magnitude below the SL of 600 ng/L with a concentration of 0.974 J 

ng/L. PFOA and PFOS were not detected in groundwater at this location. Figure 6-4 presents the 

ranges of detections for PFOA, PFOS, and PFBS in groundwater. Table 6-4 summarizes the 

detected compounds in groundwater. 

6.7.3 Sitewide Conclusions

Based on the results of the SI, PFOA, PFOS, and PFBS were not detected in soil. PFBS was 

detected in groundwater; however, PFOA and PFOS were not detected. ESLR-01 is upgradient 

of the AOIs at Esler Field AASF; therefore, data from the SI suggest the likelihood for offsite 

migration of PFAS onto the facility property from the north is low. 
Table 6-2

PFAS Detections in Surface Soil

Site Inspection Report, Esler Field AASF

Analyte OSD Screening 

Level a

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

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

PFBA - ND ND 0.069 J 0.243 J ND ND ND 0.086 J ND ND

PFBS 1900 ND ND ND 0.035 J ND ND ND ND ND ND

PFDA - ND ND ND ND ND ND ND ND ND ND

PFDoA - ND ND ND ND ND ND ND ND ND ND

PFHpA - ND ND ND 0.141 J ND ND ND 0.025 J ND ND

PFHxA - ND ND 0.061 J 0.503 J 0.044 J 0.039 J 0.029 J 0.549 J ND ND

PFHxS - 0.058 J ND 0.153 J 0.665 J 0.078 J 0.087 J 0.074 J ND 0.052 J 0.052 J

PFNA - ND ND ND 0.475 J ND ND 0.023 J 0.031 J ND 1.15 J

PFOA 130 ND ND ND 0.659 J ND ND ND ND ND ND

PFOS 130 ND ND 0.345 J 0.669 J 0.168 J 0.221 J 0.069 J ND ND 0.164 J

PFPeA - ND ND ND 0.181 J 0.027 J 0.028 J ND 0.385 J ND ND

PFTrDA - ND ND ND ND 0.261 J 0.269 J 0.036 J ND ND 0.044 J

PFUnDA - ND ND ND ND ND ND 0.036 J ND ND 0.093 J

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

PFBA perfluorobutanoic acid

PFBS perfluorobutanesulfonic acid

PFDA perfluorodecanoic acid

References PFDoA perfluorododecanoic acid

PFHpA perfluoroheptanoic acid

PFHxA perfluorohexanoic acid

PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

PFOA perfluorooctanoic acid

PFOS perfluorooctanesulfonic acid

PFPeA perfluoropentanoic acid

Interpreted Qualifiers PFTrDA perfluorotridecanoic acid

J = Estimated concentration PFUnDA perfluoro-n-undecanoic acid

Acronyms and Abbreviations

AASF Army Aviation Support Facility

AOI Area of Interest

D duplicate

ft feet

HQ hazard quotient

LCMSMS liquid chromatography with tandem mass spectrometry

LOD limit of detection

ND analyte not detected above the LOD

OSD Office of the Secretary of Defense

QSM Quality Systems Manual

Qual interpreted qualifier

SB soil boring

USEPA United States Environmental Protection Agency

μg/kg micrograms per kilogram

- not applicable

07/28/2021

0 - 2 ft

Area of Interest

Sample ID

Sample Date

Depth

AOI01-01-SB-00-02

07/28/2021

0 - 2 ft

AOI 3

AOI02-02-SB-0-2

07/26/2021

0 - 2 ft

AOI02-03-SB-00-02

07/28/2021

0 - 2 ft

AOI03-01-SB-0-2

07/27/2021

0 - 2 ft

AOI03-02-SB-0-2

07/26/2021

0 - 2 ft

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS and PFOA in Groundwater or Soil using USEPA’s Regional Screening Level

Calculator. HQ=0.1. 15 September 2021. Soil screening levels based on residential scenario for direct ingestion of contaminated soil.

AOI02-01-SB-0-2-D

07/27/2021

0 - 2 ft

AOI 1 AOI 2

AOI01-04-SB-00-02

07/28/2021

0 - 2 ft

AOI02-01-SB-0-2

07/27/2021

0 - 2 ft

AOI01-02-SB-00-02

07/28/2021

0 - 2 ft

AOI01-03-SB-00-02

AECOM 6-7
Table 6-2

PFAS Detections in Surface Soil

Site Inspection Report, Esler Field AASF

Analyte OSD Screening 

Level a

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

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

PFBA - ND 0.099 J 0.090 J ND ND 0.293 J ND

PFBS 1900 ND 0.027 J ND ND ND ND ND

PFDA - ND ND ND ND ND 0.085 J ND

PFDoA - ND ND ND ND ND 0.031 J ND

PFHpA - ND 0.025 J 0.186 J ND ND 0.085 J ND

PFHxA - 0.027 J 0.063 J 0.274 J ND ND 0.214 J ND

PFHxS - ND 0.199 J ND ND ND 0.313 J ND

PFNA - ND ND ND 0.033 J ND 6.08 ND

PFOA 130 ND ND ND ND ND 0.154 J ND

PFOS 130 ND ND ND ND ND 15.0 ND

PFPeA - ND 0.044 J 0.474 J ND ND 0.640 J ND

PFTrDA - ND ND 0.056 J ND ND 0.895 J ND

PFUnDA - ND ND 0.026 J ND ND 1.38 ND

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

PFBA perfluorobutanoic acid

PFBS perfluorobutanesulfonic acid

PFDA perfluorodecanoic acid

References PFDoA perfluorododecanoic acid

PFHpA perfluoroheptanoic acid

PFHxA perfluorohexanoic acid

PFHxS perfluorohexanesulfonic acid

PFNA perfluorononanoic acid

PFOA perfluorooctanoic acid

PFOS perfluorooctanesulfonic acid

PFPeA perfluoropentanoic acid

Interpreted Qualifiers PFTrDA perfluorotridecanoic acid

J = Estimated concentration PFUnDA perfluoro-n-undecanoic acid

Acronyms and Abbreviations

AASF Army Aviation Support Facility

AOI Area of Interest

D duplicate

ft feet

HQ hazard quotient

LCMSMS liquid chromatography with tandem mass spectrometry

LOD limit of detection

ND analyte not detected above the LOD

OSD Office of the Secretary of Defense

QSM Quality Systems Manual

Qual interpreted qualifier

SB soil boring

USEPA United States Environmental Protection Agency

μg/kg micrograms per kilogram

- not applicable

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS and PFOA in Groundwater or Soil using USEPA’s Regional Screening Level

Calculator. HQ=0.1. 15 September 2021. Soil screening levels based on residential scenario for direct ingestion of contaminated soil.

AOI03-04-SB-00-02

07/28/2021

0 - 2 ft

Sitewide

ESLR-01-SB-0-2

07/26/2021

0 - 2 ft

AOI04-01-SB-00-02

07/28/2021

0 - 2 ft

AOI04-02-SB-00-02

07/28/2021

0 - 2 ft

AOI 3 AOI 4

AOI03-06-SB-0-2

07/28/2021

0 - 2 ft

Area of Interest

Sample ID

Sample Date

Depth

AOI03-03-SB-0-2

07/28/2021

0 - 2 ft

AOI03-05-SB-00-02

07/28/2021

0 - 2 ft

AECOM 6-8
Table 6-3

PFAS Detections in Shallow Subsurface Soil

Site Inspection Report, Esler Field AASF

Analyte OSD Screening 

Level a

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

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

NEtFOSAA - ND ND ND 0.035 J ND ND ND ND ND ND

PFBA - ND ND ND ND 0.061 J ND ND ND ND ND

PFBS 25000 ND ND ND ND 0.035 J ND ND UJ 0.023 J ND ND

PFHxA - ND ND ND ND 0.164 J ND ND UJ 0.026 J ND ND

PFHxS - 0.075 J ND ND ND 0.898 J ND ND UJ 0.069 J ND ND

PFNA - 0.080 J ND ND ND ND ND ND ND ND ND

PFOS 1600 0.288 J ND ND ND ND ND 0.077 J 0.137 J ND ND

PFPeA - ND ND ND ND 0.038 J ND ND ND ND ND

PFTrDA - 0.039 J ND ND ND ND ND ND ND ND ND

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

NEtFOSAA N-ethyl perfluorooctane- sulfonamidoacetic acid

PFBA perfluorobutanoic acid

PFBS perfluorobutanesulfonic acid

References PFHxA perfluorohexanoic acid

PFHxS perfluorohexanesulfonic acid

PFOA perfluorooctanoic acid

PFOS perfluorooctanesulfonic acid

PFPeA perfluoropentanoic acid

PFTrDA perfluorotridecanoic acid

Acronyms and Abbreviations

Interpreted Qualifiers AASF Army Aviation Support Facility

J = Estimated concentration AOI Area of Interest

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

ft feet

HQ hazard quotient

LCMSMS liquid chromatography with tandem mass spectrometry

LOD limit of detection

ND analyte not detected above the LOD

OSD Office of the Secretary of Defense

QSM Quality Systems Manual

Qual interpreted qualifier

SB soil boring

USEPA United States Environmental Protection Agency

μg/kg micrograms per kilogram

- not applicable

AOI03-02-SB-9-11

07/26/2021

9 - 11 ft

Area of Interest

Sample ID

Sample Date

Depth

Sitewide

ESLR-01-SB-11-13

07/26/2021

11 - 13 ft

AOI01-01-SB-12-14

07/28/2021

12 - 14 ft

AOI03-01-SB-13-15

07/27/2021

13 - 15 ft

AOI02-01-SB-11-13

07/27/2021

11 - 13 ft

AOI02-02-SB-11-13

07/26/2021

11 - 13 ft

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS and PFOA in Groundwater or Soil using USEPA’s Regional Screening Level

Calculator. HQ=0.1. 15 September 2021. Soil screening levels based on industrial/commercial composite worker scenario for incidental ingestion of contaminated soil.

AOI 1 AOI 2 AOI 3

AOI01-01-SB-12-14-D

07/28/2021

12 - 14 ft

AOI03-02-SB-9-11-D

07/26/2021

9 - 11 ft

AOI03-03-SB-09-11

07/28/2021

9 - 11 ft

AOI01-01-SB-09-11

07/28/2021

9 - 11 ft

AECOM 6-9
Table 6-4

PFAS Detections in Groundwater

Site Inspection Report, Esler Field AASF

Analyte OSD Screening 

Level a

USEPA HA b Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual

PFBS 600 - 0.856 J ND ND ND ND ND 7.57 0.974 J

PFHxA - - 3.65 J ND ND ND ND ND ND ND

PFHxS - - 6.84 ND ND ND ND ND 126 ND

PFOA 40 70 5.13 ND ND ND ND ND ND ND

PFOS 40 70 0.810 J ND ND ND ND 1.41 J 1.09 J ND

PFPeA - - 1.50 J ND ND ND ND ND ND ND

Total PFOA+PFOS - 70 5.94 ND ND ND ND 1.41 1.09 ND

Grey Fill Detected concentration exceeded OSD Screening Levels Chemical Abbreviations

Bold Font Detected concentration exceeded USEPA HA Screening Levels PFBS perfluorobutanesulfonic acid

PFHxA perfluorohexanoic acid

PFHxS perfluorohexanesulfonic acid

References PFOA perfluorooctanoic acid

PFOS perfluorooctanesulfonic acid

PFPeA perfluoropentanoic acid

Acronyms and Abbreviations

AASF Army Aviation Support Facility

AOI Area of Interest

Interpreted Qualifiers D duplicate

J = Estimated concentration GW groundwater

HA Health Advisory

HQ hazard quotient

LCMSMS liquid chromatography with tandem mass spectrometry

LOD limit of detection

ND analyte not detected above the LOD

OSD Office of the Secretary of Defense

QSM Quality Systems Manual

Qual interpreted qualifier

USEPA United States Environmental Protection Agency

ng/l nanogram per liter

- not applicable

b. USEPA, 2016. Drinking Water Health Advisory for PFOA. Office of Water (4304T). Health and Ecological Criteria Division, Washington, DC 20460. EPA Document Number:

822-R-16-005. May 2016. / EPA. 2016. Drinking Water Health Advisory for PFOS. Office of Water (4304T). Health and Ecological Criteria Division, Washington, DC 20460. EPA

Document Number: 822-R-16-004. May 2016.

a. Assistant Secretary of Defense, 2021. Risk Based Screening Levels Calculated for PFOS and PFOA in Groundwater or Soil using USEPA’s Regional Screening Level

Calculator. HQ=0.1. 15 September 2021. Groundwater screening levels based on residential scenario for direct ingestion of groundwater.

AOI 2 AOI 3 Sitewide

ESLR-01-GW

07/26/2021

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

AOI03-02-GW

07/26/2021

AOI03-03-GW

07/28/2021

AOI02-02-GW

07/27/2021

AOI03-01-GW

07/28/2021

AOI02-01-GW

07/27/2021

AOI02-01-GW-D

07/27/2021

Area of Interest

Sample ID

Sample Date

AOI 1

AOI01-01-GW

07/28/2021

AECOM

AECOM 6-10
AOI01-04

AOI01-02

AOI01-03 AOI01-01

AOI02-01

AOI02-02

ESLR-01

AOI02-03

AOI03-01

AOI03-02

AOI03-03

AOI03-04

AOI03-05

AOI03-06

AOI04-01

AOI04-02

Mill Creek

Legend

Facility Boundary

Water Body

River/Stream

Approximate Path of Storm Sewer Pipe

PFOA Results (μg/Kg)

ND

>ND - 10

>10 - 130

>130 - 1,600

>1,600

0 350 700 1,400

Feet

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\LA\Esler_Field\Esler_Field_SI_MXDs\SI_Report\Results\Fig_6-1_Esler_Field_SI_Soil_PFOA_Results.mxd

Mill Creek

AOI01-01

AOI02-01 AOI02-02

ESLR-01

AOI03-01

AOI03-02

AOI03-03

Mill Creek

AOI01-01

AOI02-01 AOI02-02

ESLR-01

AOI03-01

AOI03-02

AOI03-03

12420 Milestone Center Drive

Germantown, MD 20876 Figure 6-1

PFOA Detections in Soil

4/21/2022

4/21/2022

MS 4/21/2022

JH

CM

GIS BY

CHK BY

PM

4/21/2022

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection for PFAS at Esler Field, LA

Base Map: Source: Esri, Maxar, GeoEye, Earthstar

Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN,

1:8,400

Shallow

Intermediate

Deep

AECOM 6-11
AOI01-04

AOI01-02

AOI01-03 AOI01-01

AOI02-01

AOI02-02

ESLR-01

AOI02-03

AOI03-01

AOI03-02

AOI03-03

AOI03-04

AOI03-05

AOI03-06

AOI04-01

AOI04-02

Mill Creek

Legend

Facility Boundary

Water Body

River/Stream

Approximate Path of Storm Sewer Pipe

PFOS Results (μg/Kg)

ND

>ND - 10

>10 - 130

>130 - 1,600

>1,600

0 350 700 1,400

Feet

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\LA\Esler_Field\Esler_Field_SI_MXDs\SI_Report\Results\Fig_6-2_Esler_Field_SI_Soil_PFOS_Results.mxd

Mill Creek

AOI01-01

AOI02-01 AOI02-02

ESLR-01

AOI03-01

AOI03-02

AOI03-03

Mill Creek

AOI01-01

AOI02-01 AOI02-02

ESLR-01

AOI03-01

AOI03-02

AOI03-03

12420 Milestone Center Drive

Germantown, MD 20876 Figure 6-2

PFOS Detections in Soil

4/21/2022

4/21/2022

MS 4/21/2022

JH

CM

GIS BY

CHK BY

PM

4/21/2022

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection for PFAS at Esler Field, LA

Base Map: Source: Esri, Maxar, GeoEye, Earthstar

Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN,

1:8,400

Shallow

Intermediate

Deep

AECOM 6-12
AOI01-04

AOI01-02

AOI01-03 AOI01-01

AOI02-01

AOI02-02

ESLR-01

AOI02-03

AOI03-01

AOI03-02

AOI03-03

AOI03-04

AOI03-05

AOI03-06

AOI04-01

AOI04-02

Mill Creek

Legend

Facility Boundary

Water Body

River/Stream

Approximate Path of Storm Sewer Pipe

PFBS Results (μg/Kg)

ND

>ND - 10

>10 - 1,900

>1,900 - 25,000

>25,000

0 350 700 1,400

Feet

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\LA\Esler_Field\Esler_Field_SI_MXDs\SI_Report\Results\Fig_6-3_Esler_Field_SI_Soil_PFBS_Results.mxd

Mill Creek

AOI01-01

AOI02-01

AOI02-02

ESLR-01

AOI03-01

AOI03-02

AOI03-03

Mill Creek

AOI01-01

AOI02-01 AOI02-02

ESLR-01

AOI03-01

AOI03-02

AOI03-03

12420 Milestone Center Drive

Germantown, MD 20876 Figure 6-3

PFBS Detections in Soil

4/21/2022

4/21/2022

MS 4/21/2022

JH

CM

GIS BY

CHK BY

PM

4/21/2022

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection for PFAS at Esler Field, LA

Base Map: Source: Esri, Maxar, GeoEye, Earthstar

Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN,

1:8,400

Shallow

Intermediate

Deep

AECOM 6-13
Mill Creek

AOI01-01

AOI02-01 AOI02-02

ESLR-01

AOI03-01

AOI03-02

AOI03-03

C:\Users\stankevichm\OneDrive - AECOM Directory\ARNG_PFAS_GIS_60552172\MXDs\LA\Esler_Field\Esler_Field_SI_MXDs\SI_Report\Results\Fig_6-4_Esler_Field_SI_Groundwater_Results.mxd

Mill Creek

AOI01-01

AOI02-01 AOI02-02

ESLR-01

AOI03-01

AOI03-02

AOI03-03

Mill Creek

AOI01-01

AOI02-01 AOI02-02

ESLR-01

AOI03-01

AOI03-02

AOI03-03

12420 Milestone Center Drive

Germantown, MD 20876 Figure 6-4

PFOA, PFOS, and PFBS Detections

 in Groundwater

4/21/2022

4/21/2022

MS 4/21/2022

JH

CM

GIS BY

CHK BY

PM

4/21/2022

CLIENT

REVISED

SCALE

PROJECT

ARNG

Site Inspection for PFAS at Esler Field, LA

Base Map: Source: Esri, Maxar, GeoEye, Earthstar

Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN,

1:8,400

PFOA

PFOS

PFBS

PFOA Results (ng/L)

ND

>ND - 10

>10 - 40

>40 - 70

>70 - 400

>400

PFOS Results (ng/L)

ND

>ND - 10

>10 - 40

>40 - 70

>70 - 400

>400

PFBS Results (ng/L)

ND

>ND - 100

>100 - 600

>600 - 1,000

>1,000 - 6,000

>6,000

Legend

Facility Boundary

Water Body

Wetland

River/Stream

Groundwater Flow Direction

Approximate Path of Storm Sewer Pipe

0 350 700 1,400

Feet

AECOM 6-14
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

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 7-4. 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 

PFOA, PFOS, or PFBS are detected, in which case the CSM figure uses a half-filled circle symbol 

to represent a potentially complete exposure pathway. Additionally, a completely filled circle symbol 

is used to indicate when a potentially complete exposure pathway has detections of PFOA, PFOS, 

or PFBS above the SLs. Areas with an identified potentially complete pathway that have detections 

of PFOA, PFOS, or PFBS above the SLs may warrant further investigation. 

In general, the potential routes of exposure to PFAS are ingestion and inhalation. Human

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

insignificant pathway compared to ingestion; however, exposure data for dermal pathways are 

sparse and continue to be the subject of PFAS toxicological study. The receptors evaluated are 

consistent with those listed in USEPA guidance for risk screening (USEPA, 2001). Receptors at 

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

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

recreational users outside of the facility boundary. 

7.1 Soil Exposure Pathway

The SI results for PFOA, PFOS, and PFBS in soil were used to determine whether a potentially 

complete pathway exists between the source and potential receptors at AOI 1 through AOI 4 

based on the aforementioned criteria. These findings are discussed below. 

7.1.1 AOI 1

Between 1996 and 2007, fire training activities occurred on the North Ramp/Wash Rack (AOI 2) 

and South Ramp (AOI 3) in which foam was dispensed from Tri-MaxTM carts and was

subsequently rinsed down nearby stormwater drains that convey stormwater to an OWS and then 

to the Sewage Oxidation Pond. The Sewage Oxidation Pond overflows at least once a year. 

PFOA, PFOS, and PFBS were detected in surface soil at AOI 1, at concentrations below their 

respective SLs, and confirm the release of PFAS to soil. Additionally, PFOS was detected in 

concentrations below the SL for shallow subsurface soil. Based on the results of the SI in AOI 1, 

ground-disturbing activities could potentially result in site worker, construction worker, or 

trespasser exposure to PFOA, PFOS, and PFBS via inhalation of dust or ingestion of soil. Lasty, 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 7-2

ground-disturbing activities could also potentially result in construction worker exposure to PFOS

in subsurface soil via ingestion. The CSM for AOI 1 is presented on Figure 7-1. 

7.1.2 AOI 2 

Between 1996 and 2007, annual fire training was conducted at the North Ramp/Wash Rack in 

which expired or near expired Tri-MaxTM foam carts were fully expended. After training, the foam 

dispensed from Tri-MaxTM carts during training was rinsed from the ramp down into a nearby 

stormwater drain that conveys stormwater southwest to an OWS and then to the Sewage 

Oxidation Pond. Additionally, Chemguard 3% AFFF is stored in each of the Hangar Buildings 6001 

and 6002. 

PFOS was detected in the surface soil at both potential release areas, whereas PFBS was 

detected in the shallow subsurface soil at North Ramp/Wash Rack. Based on the results of the SI 

in AOI 2, ground-disturbing activities could potentially result in site worker, construction worker, or 

trespasser exposure to PFOS via inhalation of dust or ingestion of surface soil. Ground-disturbing 

activities to the subsurface soil could potentially result in construction worker exposure to PFBS. 

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

7.1.3 AOI 3 

From 2005-2006 to 2007, fire training was conducted at the South Ramp in which expired, or 

nearly expired TriMaxTM foam carts were fully expended. Foam dispensed from Tri-MaxTM carts 

during training was rinsed from the ramp down into a nearby stormwater drain. Drains convey 

stormwater west to an OWS and then to the Sewage Oxidation Pond. PFOS and PFBS were 

detected in surface and shallow subsurface soil at the South Ramp, at concentrations below the 

SLs. Ground-disturbing activities could result in site worker, construction worker, and trespasser 

exposure to PFOS and PFBS in surface soil via inhalation of dust and ingestion of soil. Grounddisturbing activities to the shallow subsurface soil could result in construction worker exposure to 

PFOS and PFBS via ingestion of soil. The CSM for AOI 3 is presented on Figure 7-3. 

7.1.4 AOI 4 

From the 1980s through the 1990s, Firehouse Building 6004 was an active firehouse that stored 

5-gallon buckets of AFFF. AFFF was also stored at Storage Building 6067/6068 at the time of the 

PA. PFOA and PFOS were detected at concentrations below their respective SLs in surface soil 

at Firehouse Building 6004, whereas PFOA, PFOS, and PFBS were not detected in surface soil 

at Storage Building 6067/6068. Based on the results of the SI in AOI 4, ground-disturbing activities 

at Firehouse Building 6004 could potentially result in site worker, construction worker, and 

trespasser exposure to PFOA, PFOS, and PFBS via inhalation of dust or ingestion of surface soil. 

Shallow subsurface soil was not sampled as part of the SI; however, PFAS may have leached 

into the subsurface soil via infiltration of rainwater. Therefore, ground-disturbing activities to the 

shallow subsurface soil at Firehouse Building 6004 could result in construction worker exposure 

to PFOA and PFOS via ingestion. The CSM for AOI 4 is presented on Figure 7-4. 

7.2 Groundwater Exposure Pathway 

The SI results for PFOA, PFOS, and PFBS in groundwater were used to determine whether a 

potentially complete pathway exists between the source and potential receptors at AOI 1 through 

AOI 4 based on the aforementioned criteria. These findings are discussed below.
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 7-3

7.2.1 AOI 1

PFOA, PFOS, and PFBS in groundwater were detected at concentrations below the SLs in one 

temporary monitoring well at the Sewage Oxidation Pond. One active domestic well, located 

approximately 2 miles southeast of the facility, was identified in the surficial aquifer with a depth 

of 70 feet. Therefore, the ingestion exposure pathway for off-facility residents is considered 

potentially complete. Esler Field AASF receives its potable water from the WWD #3, which 

sources the water from seven deep groundwater wells and Big Creek. Consequently, the ingestion 

exposure pathway for site workers and trespassers is considered incomplete. Depths to water 

measured in August 2021 during the SI ranged from 6.12 to 20.62 feet bgs. At AOI 1, water was 

measured at 9.12 feet bgs. Therefore, groundwater may be encountered during construction 

activities and the ingestion exposure pathway for 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 PFBS were not detected in groundwater at the two temporary monitoring wells

at the North Ramp/Wash Rack and the Hangar Buildings 6001 and 6002. Therefore, the exposure 

pathways for all receptors are considered incomplete. The CSM for AOI 2 is presented on Figure 

7-2. 

7.2.3 AOI 3 

PFOS and PFBS were detected in groundwater at temporary monitoring wells below their 

respective SLs at the AOI 2 source area South Ramp. Potable water at Esler Field AASF is 

provided by WWD #3. Thus, the site worker ingestion exposure pathway is considered 

incomplete. One active domestic well screened within the surficial aquifer is located approximately 

2 miles southeast of the facility. Therefore, the ingestion exposure pathway for off-facility residents 

is considered potentially complete. Therefore, the ingestion exposure pathway for groundwater 

is potentially complete for off-facility residents. Depth to water at AOI 3 ranged from 6.12 feet bgs 

to 19.93 feet bgs. Consequently, the ingestion exposure pathway is potentially complete for 

construction workers during trenching activities deep enough to encounter shallow groundwater. 

The CSM for AOI 3 is presented on Figure 7-3. 

7.2.4 AOI 4 

Groundwater samples were not collected at AOI 4. However, PFOA, PFOS, and PFBS were 

detected in surface soil at the Firehouse Building 6004. PFAS is water soluble and may have 

leached into the groundwater; therefore, the ingestion exposure pathway is potentially complete 

for construction workers during trenching activities deep enough to encounter shallow 

groundwater. A downgradient domestic well is located 2 miles southeast of the facility boundary. 

If PFAS did migrate into the groundwater from AOI 4, there is a potential for off-facility residents 

to be exposed to PFOA, PFOS, and PFBS. Potable water is sourced by WWD #3; therefore, the 

ingestion exposure pathway for site workers is considered incomplete. The CSM for AOI 4 is 

presented on Figure 7-4. 

7.3 Surface Water and Sediment Exposure Pathway

The SI results for PFOA, PFOS, and PFBS 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

Esler Field Army Aviation Support Facility, Louisiana

AECOM 7-4

7.3.1 AOI 1

PFAS were potentially released to surface water and sediment at AOI 1 via stormwater 

conveyance from the fire training areas at AOI 2 and AOI 3. PFOA, PFOS, and PFBS were 

detected in soil and groundwater at AOI 1; however, no surface water or sediment samples were 

collected. Based on these results, it is likely PFAS is also within surface water and sediment as 

the detections in soil and groundwater are likely due to leaching, infiltration, and overflow. 

Consequently, the surface water and sediment exposure pathways are considered potentially 

complete for site workers, construction workers, and trespassers. Surface water overflowing the 

Sewage Oxidation Pond, which reportedly occurs at least once per year, may result in PFAS 

transport to surface soil and eventually to Flagon Bayou. Therefore, the surface water and 

sediment exposure pathways for offsite residents and recreational users using Flagon Bayou is 

potentially complete. The CSM for AOI 1 is presented on Figure 7-1. 

7.3.2 AOI 2 

Foam dispensed on the North Ramp/Wash Rack would have been conveyed to the Sewage 

Oxidation Pond via stormwater conveyance. Therefore, the surface water and sediment pathway 

for AOI 2 is evaluated as part of AOI 1. The CSM for AOI 2 is presented on Figure 7-2. 

7.3.3 AOI 3 

Foam dispensed on the South Ramp would have been conveyed to the Sewage Oxidation Pond 

via stormwater conveyance. Therefore, the surface water and sediment pathway for AOI 3 is 

evaluated as part of AOI 1. The CSM for AOI 3 is presented on Figure 7-3. 

7.3.4 AOI 4 

PFOA, PFOS, and PFBS were detected in surface soil at AOI 4. Overland flow of water could

result in the migration of these analytes into the Sewage Oxidation Pond or Flagon Bayou. 

Therefore, the exposure pathways for site workers, construction workers, trespassers, and offsite 

residents and recreational users using Flagon Bayou are considered potentially complete. The 

CSM for AOI 4 is presented on Figure 7-4. 
Media

SOURCE PATHWAY RECEPTOR

AOI 1

Runoff from

precipitation and

stormwater

conveyed from

fire training areas

to Sewage

Oxidation Pond

PFAS in

Surface

Water and

Sediment

Human

Activities

Leaching/

Infiltration

Airborne Soil

Particulate

Surface Soil

at AOIs

Surface

Water/

Sediment

Shallow

Groundwater

Subsurface

Soil

Source Release

Mechanism Media Transportand Migration Media ExposureRoutes

Inhalation of

Dust

Ingestion

Ingestion

Ingestion

Human Receptors:

Current/ Future

Flow-Chart Continues

Partial / Possible Flow

Flow-Chart Stops

Incomplete Pathway

Potentially Complete Pathway

Potentially Complete

Pathway with Exceedance

Site

Worker

Construction

Worker

Off-Facility

Resident

Trespasser/

Recreational User

Site

Worker

Construction

Worker

Off-Facility

Resident

Trespasser/

Recreational User

LEGEND

Figure 7-1

Conceptual Site Model, AOI 1

Esler Field AASF, LA

Potential

Off-Facility

Source Not

under

Control of

ARNG

/ /

/ / /

/

Ingestion

/

/

/ / /

Notes:

1. The resident and recreational user

receptors refer to an off-site resident and

recreational user.

2. Dermal contact exposure pathway is

incomplete for PFAS.

/ / /

/ / / /

Precipitation/ /

Run-Off

/

AOI 2 &

AOI 3

7-5
Media

SOURCE PATHWAY RECEPTOR

AOI 2

Fire Training

Areas; Runoff

from precipitation

PFAS in

Surface Soil

Human

Activities

Leaching/

Infiltration

Airborne Soil

Particulate

Surface Soil

at AOIs

Surface

Water/

Sediment

Shallow

Groundwater

Subsurface

Soil

Source Release

Mechanism Media Transportand Migration Media ExposureRoutes

Inhalation of

Dust

Ingestion

Ingestion

Ingestion

Human Receptors:

Current/ Future

Flow-Chart Continues

Partial / Possible Flow

Flow-Chart Stops

Incomplete Pathway

Potentially Complete Pathway

Potentially Complete

Pathway with Exceedance

Site

Worker

Construction

Worker

Off-Facility

Resident

Trespasser/

Recreational User

Site

Worker

Construction

Worker

Off-Facility

Resident

Trespasser/

Recreational User

LEGEND

Figure 7-2

Conceptual Site Model, AOI 2

Esler Field AASF, LA

Potential

Off-Facility

Source Not

under

Control of

ARNG

/ /

/ / /

/

Ingestion

/

/

/ / / /

Notes:

1. The resident and recreational user

receptors refer to an off-site resident and

recreational user.

2. Dermal contact exposure pathway is

incomplete for PFAS.

/ / /

/ /

/

Precipitation/

Run-Off

/ /

Stormwater

Conveyance

7-6
Media

SOURCE PATHWAY RECEPTOR

AOI 3

Fire Training

Areas; Runoff

from precipitation

PFAS in

Surface Soil

Human

Activities

Leaching/

Infiltration

Airborne Soil

Particulate

Surface Soil

at AOIs

Surface

Water/

Sediment

Shallow

Groundwater

Subsurface

Soil

Source Release

Mechanism Media Transportand Migration Media ExposureRoutes

Inhalation of

Dust

Ingestion

Ingestion

Ingestion

Human Receptors:

Current/ Future

Flow-Chart Continues

Partial / Possible Flow

Flow-Chart Stops

Incomplete Pathway

Potentially Complete Pathway

Potentially Complete

Pathway with Exceedance

Site

Worker

Construction

Worker

Off-Facility

Resident

Trespasser/

Recreational User

Site

Worker

Construction

Worker

Off-Facility

Resident

Trespasser/

Recreational User

LEGEND

Figure 7-3

Conceptual Site Model, AOI 3

Esler Field AASF, LA

Potential

Off-Facility

Source Not

under

Control of

ARNG

/ /

/ / /

/

Ingestion

/

/

/ / / /

Notes:

1. The resident and recreational user

receptors refer to an off-site resident and

recreational user.

2. Dermal contact exposure pathway is

incomplete for PFAS.

/ / /

/ / / /

/

Precipitation/

Run-Off

Stormwater

Conveyance

7-7
Media

SOURCE PATHWAY RECEPTOR

AOI 4

Leaks/spills

associated with

AFFF storage

PFAS in

Surface Soil

Human

Activities

Leaching/

Infiltration

Airborne Soil

Particulate

Surface Soil

at AOIs

Surface

Water/

Sediment

Shallow

Groundwater

Subsurface

Soil

Source Release

Mechanism Media Transportand Migration Media ExposureRoutes

Inhalation of

Dust

Ingestion

Ingestion

Ingestion

Human Receptors:

Current/ Future

Flow-Chart Continues

Partial / Possible Flow

Flow-Chart Stops

Incomplete Pathway

Potentially Complete Pathway

Potentially Complete

Pathway with Exceedance

Site

Worker

Construction

Worker

Off-Facility

Resident

Trespasser/

Recreational User

Site

Worker

Construction

Worker

Off-Facility

Resident

Trespasser/

Recreational User

LEGEND

Figure 7-4

Conceptual Site Model, AOI 4

Esler Field AASF, LA

Potential

Off-Facility

Source Not

under

Control of

ARNG

/ /

/ / /

/

Ingestion

/

/

/ / / /

Notes:

1. The resident and recreational user

receptors refer to an off-site resident and

recreational user.

2. Dermal contact exposure pathway is

incomplete for PFAS.

/ / /

/ / / /

Precipitation/ /

Run-Off

7-8
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

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 26 July to 3 August 2021 and consisted of utility 

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

groundwater sample collection, and land surveying. Field activities were conducted in accordance 

with the SI QAPP Addendum (AECOM, 2021a). 

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

samples were collected and analyzed for a subset of PFAS by LC/MS/MS compliant with QSM

5.3 Table B-15 as follows. The 18 PFAS analyzed as part of the ARNG SI program are specified 

in Section 5.7 of this Report.

• Thirty (30) soil samples from 16 boring locations; 

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

• Fourteen (14) QA/QC samples.

The information gathered during this investigation was used to determine if PFOA, PFOS, and/or

PFBS were present at or above SLs. Additionally, the CSMs were refined to assess whether a 

potentially complete pathway exists between the source and potential receptors for potential 

exposure to PFOA, PFOS, and PFBS at the AOIs, which are described in Section 7. 

8.2 SI Goals Evaluation

As described in Section 4.2, the SI activities were designed to achieve six main goals or DQOs. 

This section describes the SI goals and the conclusions that can be made for each based on the 

data collected during this investigation. 

1. Determine the presence or absence of PFOA, PFOS, and PFBS at or above SLs. 

PFOA, PFOS, and PFBS were detected at the Site in soil and groundwater. PFOA, PFOS, 

and PFBS were detected at AOI 1 and AOI 4, whereas PFOS and PFBS were detected at 

AOI 2 and AOI 3. PFBS was also detected in groundwater at the upgradient location 

ESLR-01. PFBS was also detected in groundwater, at concentrations several orders of 

magnitude below the SL of 600 ng/L, at location ESLR-01, which is upgradient of the AOIs. 

The detected concentrations of PFOA, PFOS, and PFBS in soil and groundwater did not 

exceed their respective SLs in any of the collected samples. 

2. Develop information to potentially eliminate a release from further consideration because 

it is determined that it poses no significant threat to human health or the environment.

Six potential PFAS release areas were removed from further consideration based on the 

groundwater and soil data collected during this SI: Sewage Oxidation Pond in AOI 1; North 

Ramp/Wash Rack and Hangar Buildings 6001 and 6002 in AOI 2; South Ramp in AOI 3; 

and Firehouse Building 6004 and Storage Building 6067/6068 in AOI 4. PFOA, PFOS, 

and PFBS were not detected in groundwater and/ or soil above the SLs in any of these 

areas; therefore, these areas pose no significant threat to human health or the 

environment. 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 8-2

3. Determine the potential need for a TCRA (applies to drinking water only). The primary 

actions that will be considered include provision of alternative water supplies or wellhead 

treatment. 

Based on the data collected during this SI, there is a potentially complete pathway 

between the potential PFAS release areas and downgradient drinking water receptors

using the active domestic well approximately 2 miles southeast of the facility boundary. 

4. Collect data to better characterize the release areas for more effective and rapid initiation 

of a RI (if determined necessary).

The geological data collected as part of the SI indicate a relatively impermeable and low 

conductivity environment, with sandy lenses of relatively high permeability and 

conductivity observed in the deeper subsurface.

The relatively impermeable subsurface soil is characterized by 10 to 26 feet-thick silt and 

clay. Lenses of sand, ranging from 0.5 to 6 feet in thickness, underly the silt and clay. 

These lenses are characterized as fine-grained, poorly graded sand to clayey/silty sand

and represent the most permeable portions of the subsurface. Groundwater in the 

subsurface would, therefore, preferentially flow through these areas of high conductivity 

creating probable flow paths for PFAS in groundwater. These observations are consistent 

with the fluviatile silts and sands of the Dough Hills Member. 

Depth to water at the Esler Field AASF ranges from 6.12 to 19.93 feet bgs. Groundwater 

flow direction at Esler Field AASF is to the southeast, towards Flagon Bayou. These 

geologic and hydrogeologic observations inform the development of the technical

approach for future work. 

5. If PFOA, PFOS, and PFBS are determined to be present, aim to evaluate whether the 

concentrations can be attributed to on-facility or off-facility sources that were identified 

within 4 miles of the installation as part of the PA (e.g., fire stations, major manufacturers, 

other DoD facilities)

Based upon the evaluation of groundwater and soil results in comparison to SLs, in 

combination with the groundwater flow direction analysis, the results of the SI indicate that 

the source of detected concentrations of PFOA, PFOS, and PFBS at the facility is likely 

attributable to ARNG activities and the fire departments (i.e., Holloway VFD and Holloway 

Village Fire Department) that used the Firehouse Building 6004 and trained on the North 

and South Ramps. 

6. Determine whether a potentially complete pathway exists between the source and 

potential receptors and whether ARNG is the likely source of the contamination. 

Detections of PFOA, PFOS, and PFBS in soil and groundwater at source areas and the 

facility boundary indicate there is a potentially complete pathway between source and 

receptor. 

8.3 Outcome 

Based on the CSMs developed and revised in light of the SI findings, there is potential for 

exposure to drinking water receptors from AOI 1 through AOI 4 from sources on facility resulting 

from historical DoD activities. Sample analytical concentrations collected during the SI were 

compared against the project SLs for PFOA, PFOS, and PFBS 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: 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 8-3

• At AOI 1, PFOA, PFOS, and PFBS were detected in groundwater at the Sewage Oxidation 

Pond potential PFAS release area but were below the SLs concentrations of 5.13 ng/L, 

0.810 J ng/L, and 0.856 J ng/L. Based on the results of the SI, further evaluation of AOI 1 

is not warranted.

• At AOI 2, PFOA, PFOS, and PFBS were not detected in groundwater at the North 

Ramp/Wash Rack and Hangar Buildings 6001 and 6002 potential PFAS release areas. 

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

• At AOI 3, PFOS and PFBS were detected in groundwater at the South Ramp at 

concentrations below the SLs. The maximum detection of PFOS was 1.41 J ng/L at 

AOI03-02, whereas PFBS was only detected at AOI03-03, with a concentration of 7.57 

ng/L. PFOA was not detected in any of the three temporary well locations. Based on the 

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

• At AOI 4, no groundwater samples were collected. At the Storage Building 6067/6068, 

PFOA, PFOS, and PFBS were not detected in soil. At the Firehouse Building 6004, PFOA, 

and PFOS were detected at concentrations below the SLs. Based on the results of the 

SI, further evaluation of AOI 4 is not warranted.

• The detected concentrations of PFOA, PFOS, and PFBS in soil at all AOIs were below the 

SLs. 

Table 8-1 summarizes the SI results for soil and groundwater. Based on the CSMs developed 

and revised in light of the SI findings, there is potential for exposure to drinking water receptors 

caused by DoD activities at the facility. 

Table 8-2 summarizes the rationale used to determine if an AOI should be considered for further 

investigation under CERCLA and undergo an RI. Based on the results of this SI, further evaluation 

is not warranted for AOI 1: Sewage Oxidation Pond, AOI 2: North Ramp/Wash Rack, AOI 2: 

Hangar Buildings 6001 and 6002, AOI 3: South Ramp, AOI 4: Storage Buildings 6067/6068, and 

AOI 4: Firehouse Building 6004.
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 8-4

Table 8-1: Summary of Site Inspection Findings

AOI Potential PFAS 

Release Area

Soil –

Source Area

Groundwater –

Source Area

Groundwater –

Facility Boundary

1 Sewage Oxidation Pond N/A

2

North Ramp/Wash Rack N/A

Hangar Buildings 6001 & 

6002 N/A

3 South Ramp

4 

Firehouse Building 6004 N/A N/A

Storage Building 

6067/6068 N/A N/A

Legend:

N/A = Not applicable 

= detected; exceedance of the screening levels

= detected; no exceedance of the screening levels

= not detected

Table 8-2: Site Inspection Recommendations

AOI Description Rationale Future Action

1 Sewage Oxidation 

Pond

PFOA, PFOS, and PFBS detected in 

groundwater at source area below the SLs. 

No exceedances of SLs in soil. 

No further action

2 

North Ramp/Wash 

Rack

No detections of PFOA, PFOS, and PFBS 

in groundwater. No exceedances of SLs in 

soil. 

No further action

Hangar Buildings 

6001 & 6002 

No detections of PFOA, PFOS, and PFBS 

in groundwater. No exceedances of SLs in 

soil. 

No further action

3 South Ramp

Detections of PFOS and PFBS in 

groundwater below the SLs. No detections 

of PFOA in groundwater. No exceedances 

of SLs in soil.

No further action

4 

Firehouse Building 

6004 No exceedances of SLs in soil. No further action

Storage Building 

6067/6068

No detections of PFOA, PFOS, or PFBS in 

soil. No further action
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

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, Esler Field Army Aviation Support Facility, 

Louisiana. July. 

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

Addendum, Esler Field Army Aviation Support Facility, Louisiana, Perfluorooctane Sulfonic 

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

Nationwide. July. 

AECOM. 2021b. Final Site Safety and Health Plan, Esler Field Army Aviation Support Facility, 

Louisiana, Perfluorooctane Sulfonic Acid (PFOS) and Perfluorooctanoic Acid (PFOA) 

Impacted Sites ARNG Installations, Nationwide. July. 

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

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

15 September. 

Charrier, Roy. 2020. Telephone communication. 10 January 2020.

DA. 2016. Army Guidance to Address Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic 

Acid (PFOA) Contamination. August.

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.

EA Engineering Science and Technology, 2021. SOP No. 042A for Treating Liquid InvestigationDerived Material (Purge water, drilling water, and decontamination fluids).

EDR TM (Environmental Data Resources, Inc.TM). 2019. Radius Map Report with GeoCheck® 

Addendum, Esler Field, LA. April

French, James. 2020. Telephone communication. 10 January 2020.

Horst, Jerald. 2019. Defining Lake Catahoula, Louisiana Sportsman. Accessed December 2019 

at https://www.louisianasportsman.com/hunting/waterfowl-duck-hunting/defining-lakecatahoula/. 

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.
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 9-2

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 ant Transport for Per- and Polyfluoroalkyl Substances. March. 

LAARNG (Louisiana Army National Guard). n.d. Esler Field History. (Accessed November 2019 

at https://geauxguard.la.gov/installations/camp-beauregard/esler-field/. 

LAARNG. 2007. Final Integrated Natural Resources Management Plan, Louisiana Army National 

Guard, Camp Beauregard, Louisiana, Fiscal Years 2006–2010. February. 

Louisiana Department of Natural Resources. 2021. SONRISNG Interactive Maps – Oil/Gas. 

Accessed 18 May 2021 at http://sonriswww.dnr.state.la.us/gis/agsweb/IE/JSViewer/index.html?TemplateID=181. 

NOAA (National Oceanic and Atmospheric Administration). 1982. Mean Monthly, Seasonal and 

Annual Pan Evaporation for the United States, December. Accessed January 2020 at 

https://www.nws.noaa.gov/oh/hdsc/PMP_related_studies/TR34.pdf. 

NOAA. 2019. Climate Information for Alexandria Esler Field Rapides Parish Louisiana. Accessed 

December 2019 at https://www.weather.gov/lch/KESF. 

Tomaszewski, D.J. 2009. Ground-water Resources in Rapides Parish, Louisiana, 2005: Louisiana 

Department of Transportation and Development Water Resources Technical Report no. 78. 

54 p.

USACE (US Army Corps of Engineers). 2014. Operational Range Assessment Phase II Report, 

Camp Beauregard, Louisiana. July.

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

USACHPPM (US Army Center for Health Promotion and Preventative Medicine). Army 

Operational Range Assessment Team. 2004. Range Condition Assessment No. 38-EH-02RN04, Louisiana Army National Guard, Major Training Area Camp Beauregard, Louisiana. 16-19 

March. 

USAEHA (US Army Environmental Hygiene Agency). 1994. Site Assessment Survey No. 38-26-

1333-94, Camp Beauregard, Louisiana Army National Guard. 18–22 July.

USDA (U.S. Department of Agriculture), Soil Conservation Service. 1980. Soil Survey of Rapides 

Parish, Louisiana. 

USDA. Natural Resources Conservation Service. 2019. Web Soil Survey. 

https://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx (Accessed December 

2019).

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

(CERCLA). 

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

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

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

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

Assessments). December.

USEPA. 2005. Federal Facilities Remedial Site Inspection Summary Guide. 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 9-3

USEPA. 2006. Guidance on Systematic Planning using the Data Quality Objectives Process. 

February.

USEPA. 2016a. Drinking Water Health Advisory for Perfluorooctanoic Acid (PFOA). Office of 

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

Document Number: 822-R-16-005. May 2016.

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

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

Document Number: 822-R-16-004. May 2016.

USEPA. 2017a. UCMR 3 (2013-2015) Occurrence Data by State. Occurrence Data for the 

Unregulated Contaminant Monitoring Rule. Accessed 9 July 2019 at https://www.epa.gov/

dwucmr/occurrence-data-unregulated-contaminant-monitoring-rule. January.

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

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

Innovation. January.

USFWS. 2021. Listed Species Believed to or Known to Occur in Rapides, Louisiana.

Environmental Conservation Online System (ECOS). Accessed 25 August 2021 at 

https://ecos.fws.gov/ecp/report/species-listings-by-current-range-county?fips=22079. 

USGS. 2019a. Geology of Avoyelles and Rapides Parishes: Louisiana Geological Survey, 

Geological Bulletin GB-18, scale 1:62,500 (original data source referenced as Fisk, H.N., 

1940). National Geologic Map Database. Accessed December 2019 at 

https://ngmdb.usgs.gov/ngm-bin/pdp/zui_viewer.pl?id=2566. 

USGS. 2019b. Groundwater Atlas of the United States, Arkansas, Louisiana, Mississippi. 

Accessed December 2019 at https://pubs.usgs.gov/ha/ha730/ch_f/F-text3.html. 

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

and Perfluorooctanoate (PFOA) in Soils and Groundwater of a U.S. Metropolitan Area: 

Migration and Implications for Human Exposure. Water Research 72: 64-74. 
Site Inspection Report

Esler Field Army Aviation Support Facility, Louisiana

AECOM 9-4

THIS PAGE INTENTIONALLY BLANK