FINAL 

Site Inspection Report 

Army Aviation Support Facility #1 

Hammond, Louisiana 

Site Inspection for Perfluorooctanoic Acid (PFOA), Perfluorooctanesulfonic Acid (PFOS), 

Perfluorobutanesulfonic Acid (PFBS), Perfluorohexanesulfonic Acid (PFHxS), 

Perfluorononanoic Acid (PFNA), and Hexafluoropropylene Oxide Dimer Acid (HFPO-DA)

ARNG Installations, Nationwide

June 2023 

Prepared for: 

Army National Guard Headquarters 

111 S. George Mason Drive 

Arlington, VA 22204 

UNCLASSIFIED
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Site Inspection Report

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EA Project No. 634250383 i 

TABLE OF CONTENTS

Page

LIST OF APPENDICES ................................................................................................................ iii

LIST OF FIGURES ....................................................................................................................... iv

LIST OF TABLES .......................................................................................................................... v

LIST OF ACRONYMS AND ABBREVIATIONS ...................................................................... vi

EXECUTIVE SUMMARY ...................................................................................................... ES-1

1. INTRODUCTION ............................................................................................... 1-1

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

1.2 Site Inspection Purpose ............................................................................ 1-1

2. FACILITY BACKGROUND .............................................................................. 2-1

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

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

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

2.2.2 Hydrogeology ........................................................................... 2-1

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

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

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

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

2.3 History of PFAS use ................................................................................ 2-3

3. SUMMARY OF AREAS OF INTEREST ........................................................... 3-1

3.1 AOI 1 – C12 HANGAR ........................................................................... 3-1

3.2 AOI 2 – MAIN HANGAR AND FLIGHT LINE-APRON ..................... 3-1

3.3 Adjacent Sources ..................................................................................... 3-2

3.3.1 Former AASF Clam Shell Hangars .......................................... 3-2

3.3.2 Aircraft Crash Site .................................................................... 3-2

3.3.3 405 South Oak Street ................................................................ 3-2

3.3.4 Nickel Plating............................................................................ 3-3

3.3.5 Chrome Plating ......................................................................... 3-3

3.3.6 Hammond Airport U.S. Customs Building ............................... 3-3

3.3.7 Hammond Fire Station .............................................................. 3-3

3.3.8 City of Hammond Water and Sewer ......................................... 3-3

4. PROJECT DATA QUALITY OBJECTIVES ..................................................... 4-1
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4.1 Problem Statement ................................................................................... 4-1

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

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

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

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

5. SITE INSPECTION ACTIVITIES ...................................................................... 5-1

5.1 Pre-Investigation Activities ..................................................................... 5-2

5.1.1 Technical Project Planning ....................................................... 5-2

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

5.1.3 Source Water and PFAS Sampling Equipment Acceptability .. 5-3

5.2 Soil Borings and Soil Sampling ............................................................... 5-3

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

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

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

5.6 Investigation-Derived Waste ................................................................... 5-6

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

5.8 Deviations from the SI UFP-QAPP Addendum and Supplemental UFPQAPP Addendum..................................................................................... 5-6

6. SITE INSPECTION RESULTS .......................................................................... 6-1

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

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

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

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

6.3.2 AOI 1 Groundwater Analytical Results .................................... 6-3

6.3.3 Conclusions ............................................................................... 6-3

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

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

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

6.4.3 Conclusions ............................................................................... 6-4

7. EXPOSURE PATHWAYS .................................................................................. 7-1

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

7.1.1 AOI 1 – C12 Hangar ................................................................. 7-2

7.1.2 AOI 2 – Main Hangar and Flight Line-Apron .......................... 7-2

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

7.2.1 AOI 1 – C2 Hangar ................................................................... 7-2
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7.2.2 AOI 2 – Main Hangar and Flight Line-Apron .......................... 7-3

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

8. SUMMARY AND OUTCOME .......................................................................... 8-1

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

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

9. REFERENCES .................................................................................................... 9-1

LIST OF APPENDICES

Appendix A. Data Usability Assessment and Validation Reports

Appendix B. Field Documentation

 B1. Log of Daily Notice of Field Activities

 B2. Sampling Forms 

 B3. Survey Data 

B4. Non-Conformance Report

Appendix C. Photographic Log 

Appendix D. Technical Project Planning Meeting Minutes 

Appendix E. Laboratory Reports

Appendix F. Boring Logs and Well Construction Diagrams

Appendix G. Analytical Results
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LIST OF FIGURES

Figure 2-1 Facility Location

Figure 2-2 Facility Topography 

Figure 2-3 Groundwater Features 

Figure 2-4 Groundwater Elevations, August 2021 

Figure 2-5 Groundwater Elevations, April 2022 

Figure 2-6 Surface Water Features

Figure 3-1 Areas of Interest

Figure 5-1 Site Inspection Sample Locations

Figure 6-1 PFOS Detections in Soil (AOI 1 and AOI 2)

Figure 6-2 PFOA Detections in Soil (AOI 1 and AOI 2)

 

Figure 6-3 PFBS Detections in Soil (AOI 1 and AOI 2)

Figure 6-4 PFHxS Detections in Soil (AOI 1 and AOI 2)

Figure 6-5 PFNA Detections in Soil (AOI 1 and AOI 2)

Figure 6-6 PFOS, PFOA, and PFBS Detections in Groundwater (AOI 1 and AOI 2) 

Figure 6-7 PFHxS and PFNA Detections in Groundwater (AOI 1 and AOI 2) 

Figure 7-1 Conceptual Site Model, AOI 1 

Figure 7-2 Conceptual Site Model, AOI 2
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EA Project No. 634250383 v

LIST OF TABLES

Table ES-1 Screening Levels (Soil and Groundwater) 

Table ES-2 Summary of Site Inspection Findings and Recommendations 

Table 5-1 Samples by Medium, Hammond AASF #1, Louisiana, Site Inspection Report 

Table 5-2 Soil Boring Depths and Temporary Well Screen Intervals, Hammond AASF #1, 

Louisiana, Site Inspection Report 

Table 5-3 Groundwater Elevation, Hammond AASF #1, Louisiana, Site Inspection Report 

Table 6-1 Screening Levels (Soil and Groundwater) 

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

Report, Hammond AASF #1, Louisiana 

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

Site Inspection Report, Hammond AASF #1, Louisiana 

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

Inspection Report, Hammond AASF #1, Louisiana 

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

Report, Hammond AASF #1, Louisiana 

Table 8-1 Summary of Site Inspection Findings 
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EA Engineering, Science, and Technology, Inc., PBC vi

LIST OF ACRONYMS AND ABBREVIATIONS 

°C degrees Celsius

°F degrees Fahrenheit

% percent

μg/kg microgram(s) per kilogram

AASF Army Aviation Support Facility 

AFFF aqueous film forming foam 

AOI Area of Interest

ARNG Army National Guard

bgs below ground surface 

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act 

CSM conceptual site model

DoD Department of Defense

DPT direct-push technology

DQI Data quality indicator

DQO data quality objective

EA EA Engineering, Science, and Technology, Inc., PBC 

HDPE high-density polyethylene 

HFPO-DA hexafluoropropylene oxide dimer acid

IDW investigation-derived waste

LAARNG Louisiana Army National Guard 

LC/MS/MS liquid chromatography tandem mass spectrometry

ng/L nanogram(s) per liter 

OSD Office of the Secretary of Defense

PA preliminary assessment

PFAS per- and polyfluoroalkyl substances 

PFBS perfluorobutanesulfonic acid

PFHxS perfluorohexanesulfonic acid 

PFNA perfluorononanoic acid 

PFOA perfluorooctanoic acid 

PFOS perfluorooctanesulfonic acid

PVC polyvinyl chloride

QA quality assurance

QC quality control 
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QSM Quality Systems Manual

RI remedial investigation 

SI site inspection

SL screening level

TOC total organic carbon

TPP Technical Project Planning 

UFP-QAPP Uniform Federal Policy Quality Assurance Project Plan

USACE U.S. Army Corps of Engineers 

USEPA U.S. Environmental Protection Agency 

Wood Wood Environment & Infrastructure Solutions, Inc.

WSP WSP USA Environment & Infrastructure, Inc.
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EXECUTIVE SUMMARY

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

Inspections (SIs) at ARNG facilities nationwide based on the current or potential historical use of 

per- and polyfluoroalkyl substances (PFAS), with a focus on the six compounds presented in the 

memorandum regarding Investigating Per- and Polyfluoroalkyl Substances within the 

Department of Defense Cleanup Program (Assistant Secretary of Defense, 2022) from the Office 

of the Secretary of Defense (OSD) dated 6 July 2022. The six compounds listed in the OSD 

memorandum include perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), 

perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), hexafluoropropylene 

oxide dimer acid (HFPO-DA)1

 and perfluorobutanesulfonic acid (PFBS). These compounds are 

collectively referred to as “relevant compounds” throughout this document and the applicable 

Screening Levels (SLs) are provided below in Table ES-1. 

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

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

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

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

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

relevant compounds. This SI was completed at the Army Aviation Support Facility (AASF) #1 in 

Hammond, Louisiana and determined that further investigation is warranted for AOI 1: C12 

Hangar, but no further evaluation is warranted for AOI 2. Hammond AASF #1, Louisiana will 

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

The Facility, operated by Louisiana ARNG, encompasses approximately 147 acres owned by the 

Hammond Municipal Airport in Hammond, Louisiana. Operations at Hammond AASF #1 began 

in 2009; the land was previously undisturbed (AECOM, 2020). Hammond AASF #1 is a 

controlled access facility and is adjacent to both the Hammond Northshore Regional Airport and 

an Air National Guard facility. The Hammond Airport is owned by the city of Hammond and is a 

public use, joint civil-military, general aviation airport. Hammond AASF #1 houses and 

maintains aircraft.

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

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

Based on the results of this SI, and following the Comprehensive Environmental Response, 

Compensation, and Liability Act (CERCLA) process, further evaluation is warranted in a 

remedial investigation for AOI 1. Based on the results of this SI, no further evaluation under 

CERCLA is warranted for AOI 2.

1 Of the six PFAS compounds presented in the 6 July 2022 OSD memorandum, HFPO-DA (commonly referred to as 

GenX) was not included as an analyte at the time of this SI, as screening values were established after SI planning 

and execution. However, ARNG will add HFPO-DA to the list of constituents sampled during the next phase of 

CERCLA if warranted.
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EA Engineering, Science, and Technology, Inc., PBC ES-2

Table ES-1. Screening Levels for Soil and Groundwater

Analyte2

Residential (Soil)

(0-2 feet bgs)

(μg/kg)1

Industrial/Commercial 

Composite Worker (Soil)

(2-15 feet bgs)

(μg/kg)1

Tap Water 

(Groundwater)

(ng/L)1

PFOA 19 250 6

PFOS 13 160 4

PFBS 1,900 25,000 601

PFHxS 130 1,600 39

PFNA 19 250 6

Notes:

1. Assistant Secretary of Defense, July 2022. Risk Based Screening Levels in Groundwater and

Soil using United States Environmental Protection Agency’s (USEPA’s) Regional Screening

Level Calculator. Hazard Quotient (HQ) = 0.1. May 2022.

2. Screening values for HFPO-DA were established after site inspection planning and execution 

and thus HFPO-DA is not included as an analyte. Future CERCLA phases will include

HFPO-DA if warranted.

Abbreviations:

μg/kg = microgram(s) per kilogram

bgs = below ground surface

CERCLA = Comprehensive Environmental Response, Compensation, and Liability Act

HFPO-DA hexafluoropropylene oxide dimer acid

ng/L = nanogram(s) per liter

PFBS = perfluorobutanesulfonic acid

PFHxS = perfluorohexanesulfonic acid

PFNA = perfluorononanoic acid

PFOA = perfluorooctanoic acid

PFOS = perfluorooctanesulfonic acid

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

AOI Potential Release 

Area

Soil –

Source Area

Groundwater –

Source Area

Groundwater – 

Facility Boundary Future Action

1 C12 Hangar Proceed to RI

2 Main Hangar and 

Flight Line-Apron NFA

Legend:

= detected; exceedance of screening levels.

= detected; no exceedance of screening levels.

= not detected.

Abbreviations:

AOI = area of interest

NFA = no further action

RI = remedial investigation
Site Inspection Report 

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EA Engineering, Science, and Technology, Inc., PBC 1-1

1. INTRODUCTION

1.1 PROJECT AUTHORIZATION

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

Assessments (PAs) and Site Inspections (SIs) at ARNG facilities nationwide based on the current 

or potential historical use of per- and polyfluoroalkyl substances (PFAS) with a focus on the six 

compounds presented in the memorandum regarding Investigating Per- and Polyfluoroalkyl 

Substances within the Department of Defense Cleanup Program (Assistant Secretary of Defense, 

2022) from the Office of the Secretary of Defense (OSD) dated 6 July 2022. The six compounds 

listed in the OSD memorandum are referred to as “relevant compounds” throughout this 

document and include perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), 

perfluorobutanesulfonic acid (PFBS), perfluorononanoic acid (PFNA), perfluorohexanesulfonic 

acid (PFHxS), and hexafluoropropylene oxide dimer acid (HFPO-DA)1. The ARNG performed 

this SI at the Hammond Army Aviation Support Facility (AASF) #1 in Hammond, Louisiana. 

Hammond AASF #1 is also referred to as the “Facility” throughout this report. 

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

Response, Compensation, and Liability Act (CERCLA) (U.S. 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 U.S. 

Department of Army requirements and guidance for field investigations. 

1.2 SITE INSPECTION PURPOSE

A PA was performed at Hammond AASF #1 (AECOM, 2020) that identified two Areas of 

Interest (AOIs) where PFAS-containing materials may have been used, stored, disposed or 

released historically. The objective of the SI is to identify whether there has been a release to the 

environment from the AOIs identified in the PA and determine whether further investigation is 

warranted, a removal action is required to address immediate threats, or no further action is 

required based on screening levels (SLs) for the relevant compounds. 

1 Of the six PFAS compounds presented in the 6 July 2022 OSD memorandum, HFPO-DA (commonly referred to as 

GenX) was not included as an analyte at the time of this SI, as screening values were established after SI planning 

and execution. However, ARNG will add HFPO-DA to the list of constituents sampled during the next phase of 

CERCLA if warranted.
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2. FACILITY BACKGROUND

2.1 FACILITY LOCATION AND DESCRIPTION

Hammond AASF #1 is co-located with Hammond Northshore Regional Airport and an Air 

National Guard facility. Hammond AASF #1 is just north of Highway 190 at 1399 Industrial 

Park Road Hammond, LA 70701, in Tangipahoa Parish (Figure 2-1). Hammond AASF #1 is 

located on 147 acres of land owned by the Hammond Municipal Airport. Operations at 

Hammond AASF #1 began in 2009; the land was previously undisturbed (AECOM, 2020). 

2.2 FACILITY ENVIRONMENTAL SETTING

Hammond AASF #1 lies within the Gulf Coast Physiographic Province, a region characterized 

by gently sloping, low relief land. The landscape has been formed primarily by fluvial deposits. 

There are numerous marshes, swamps, and lakes in the vicinity of Hammond AASF #1, and the 

region’s streams are characterized as sluggish. The elevation of the Facility is approximately 45 

feet above mean sea level (AECOM, 2020) (Figure 2-2).

2.2.1 Geology 

Hammond AASF #1 is located within the East Gulf Coastal Plain section of the Coastal Plain 

Physiographic province of Louisiana. Specifically, the Facility is located above Pleistocene 

Terrace deposits, which make up approximately 20 percent (%) of Louisiana’s surficial geology. 

The geology is characterized by unconsolidated sediments of lithologic variability as a result of 

the alluvial depositional environment, with intermittent occurrences of back-swamp deposits. 

This setting produced deposits exhibiting vertical and lateral stratigraphic changes over short 

distances. The terraces are a result of the paleo-Mississippi River (AECOM, 2020). During the 

SI, soils encountered consisted of sandy silts and loam and clay, and borings were completed at 

depths between 2 and 32 feet below ground surface (bgs). Samples for grain size analyses were 

collected at two locations, AOI01-01 and AOI02-02, and analyzed via ASTM International 

Method D-422. The results indicate that the soil samples are primarily composed of silt (51.13% 

to 73.42%), clay (18% to 25.5%), and sand (1.03% to 25.04%). These results and Facility

observations are consistent with the reported depositional environment of the region. Boring 

logs are presented in Appendix F and grain size results are presented in Appendix G. 

2.2.2 Hydrogeology 

Hammond AASF #1 is located within the Coastal Lowlands Aquifer system. These aquifers 

consist of primarily alluvial and deltaic deposits that are as much as 13,000 feet deep in southern 

Louisiana. Underneath the Hammond area lies the Chicot Equivalent, Evangeline Equivalent, 

and the Jasper Equivalent Aquifer Systems. The primary aquifer used in the Hammond area is 

the Tchefuncta aquifer, which is a part of the Jasper Equivalent Aquifer System. Groundwater 

flow at the Facility (Figure 2-3) is inferred to be to the south as indicated in the PA report 

(AECOM, 2020). Groundwater flow based on measured groundwater elevations was inferred to 

be to the southeast during the August 2021 SI sampling event and to the northeast during the 

April 2022 SI sampling event (Figure 2-4 and Figure 2-5). 
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EA Project No. 634250383 2-2

Municipal water supplies in this area are obtained from wells with depths of 2,500 to 2,600 feet 

bgs. In a 2009 investigation, groundwater was encountered at depths between 5 to 20 feet bgs at 

the neighboring Air National Guard facility. The PA indicated that the shallowest water bearing 

unit occurs at 7 to 18 feet bgs (AECOM, 2020). The measured depth to groundwater in temporary 

monitoring wells installed during the SI ranged from approximately 2 to 27 feet bgs.

No potable wells are located within the Facility boundary. The Facility receives potable water 

from a municipal source. Three industrial use wells are located within the Facility. One irrigation 

well was also identified during the PA within the Facility; however, the ARNG indicated that 

this well could not be located. An EDRTM report conducted a well search as part of the PA for a 

1-mile radius surrounding the Facility. Using additional online resources, such as state and local

GIS databases, wells were researched to a 4-mile radius of the Facility as part of the PA. The

EDRTM report lists two public supply wells, one to the west-southwest, and one to the eastnortheast, at distances of 0.87 mile and 0.91 mile, respectively. Several domestic wells are listed

on the EDRTM within 1 mile of the Facility boundaries. The wells identified during the PA are

depicted on Figure 2-3. These wells are typically screened in the Chicot Equivalent Aquifer

System (AECOM, 2020).

2.2.3 Hydrology 

Hammond AASF #1 is located in the Lower Mississippi Lake Maurepas watershed, in a former 

wetlands area. There are no natural surface water bodies at the Facility. A drainage channel 

flows along the western and southern boundaries of the Facility (Figure 2-6). The watershed 

eventually drains to Lake Maurepas, which drains to Lake Pontchartrain and ultimately to the 

Gulf of Mexico (AECOM, 2020). 

2.2.4 Climate

The climate in Hammond, LA is humid and warm. The average annual temperature is 66.75 

degrees Fahrenheit (°F). Seasonally, temperatures vary, with average summer highs of 91.3°F 

and average winter lows of 63°F. Average precipitation is 62.72 inches per year (AECOM, 

2020). 

2.2.5 Current and Future Land Use

Hammond AASF #1 is a controlled access facility and is adjacent to both the Hammond 

Northshore Regional Airport and an Air National Guard facility. The Hammond Airport is 

owned by the city of Hammond and is a public use, joint civil-military, general aviation airport. 

Hammond AASF #1 has been operational since 2009, and it houses and maintains aircraft. 

Future land use is not anticipated to change (AECOM, 2020). The Facility is fenced with 

restricted access.

2.2.6 Sensitive Habitat and Threatened/Endangered Species

A wildlife survey has not occurred at the Facility. The following species are listed as federally 

endangered, threatened, proposed, recovery, and/or candidate species in Tangipahoa County, 

Louisiana (USFWS, 2022): 
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Mammals:

• Tricolored bat, Perimyotis subflavus (proposed endangered)

• West Indian manatee, Trichechus manatus (threatened)

• Louisiana black bear, Ursus americanus luteolus (recovery)

Ferns and Allies:

• Louisiana quillwort, Isoetes louisianensis (endangered)

Birds:

• Red-cockaded woodpecker, Picoides borealis (endangered)

• Brown pelican, Pelecanus occidentalis (recovery)

Fishes:

• Gulf sturgeon, Acipenser oxyrinchus (threatened)

Insects:

• Monarch butterfly, danaus plexippus (candidate)

Reptiles:

• Gopher tortoise, Gopherus polyphemus (threatened)

• Ringed map turtle, Graptemys oculifera (threatened)

2.3 HISTORY OF PFAS USE 

Two potential PFAS release areas were identified at the Facility during the PA (AECOM, 2020). 

Interviews and records obtained during the PA indicate that the C12 Hangar (AOI 1) and the 

Main Hangar and Flight Line-Apron (AOI 2) have fire-suppression systems charged with 

aqueous film forming foam (AFFF) that may have accidentally spilled or discharged to the 

ground surface. 

AOI 1 houses C12 aircraft maintenance operations. According to the PA report, the C12 Hangar 

was constructed between 2007 and 2009 and is charged with a Chemguard AFFF suppression 

deluge system with a 441-gallon-capacity tank. The system is manually operated by a hose 

inside the hangar, and according to the LAARNG, the AFFF storage tank is located in an 

adjacent room (#15) within the C12 Hangar (AECOM, 2020). The ARNG also indicated a 36-

gallon fire suppression tank is located against a wall within the hangar. 
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AOI 2 houses helicopter maintenance operations. According to the PA report, the Main Hangar 

was constructed between 2007 and 2009 and is charged with a Buckeye 3% AFFF concentrate 

suppression deluge system fed by a 999-gallon tank (AECOM, 2020). 
Army National Guard Site Inspections

Site Inspection Report

Army Aviation Support Facility #1

Hammond, Louisiana

Figure 2-1

Facility Location

3

0 2

Miles

Facility Data

)

LA

Data Sources: 

ESRI 2020

AECOM 2020

Date:........................October 2022

Prepared By:.........................WSP

Prepared For:....................USACE

Projection:........WGS 84 UTM 15N

Army Aviation Support Facility #1

Facility Boundary 
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Figure 2-2

Topography

3

0 0.5

Miles

Facility Data

)

LA

Data Sources: 

ESRI 2020

AECOM 2020

Date:......................October 2022

Prepared By:........................WSP

Prepared For:....................USACE

Projection:........WGS 84 UTM 15N

Army Aviation Support Facility #1

Facility Boundary 

Note:

Contour interval (feet amsl): 5 feet
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Figure 2-3

Groundwater Features

Data Sources: 

ESRI 2020

AECOM 2020

Date:.....................November 2022

Prepared By:........................Wood

Prepared For:....................USACE

)

LA

Scale: Approximate. For general reference only.

0 3

Miles

Note: Figure shown adapted from AECOM Preliminary Assessment Report (2020) Figure: 1-2.
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Figure 2-4

Groundwater Elevations - August 2021

!(

!(

!(

!(

!(

!(

!(

Flight Line - Apron

Former AASF 

Clam Shell 

Hangars

Main Hangar

Drainage Pond

AOI 2

AOI 1

Concrete Pond

Concrete Pond

AOI02-06

34.61

AOI02-03

(not installed)

AOI02-05

37.11

AOI02-04

37.71

AOI01-02

(dry)

AOI01-01

32.29*

AASF-01

38.38

38.0

37.5

37.0

36.5

36.0

35.5

35.0

3

0 400

Feet

Date:...............November 2022

Prepared By:.................WSP

Prepared For:............USACE

)

LA

Selser Canal

Facility Data

Facility Boundary

Area of Interest (AOI)

Potential PFAS

Release Site

Hydrology/Hydrogeology

Water Body

Groundwater Elevation Contour Interval (0.5 foot)

River/Stream

Surface Water Flow Direction

Inferred Shallow Groundwater Flow Direction

Sample Location

!( Soil Boring and Temporary

Monitoring Well

Note: Certain features digitized

from georeferenced AECOM

Preliminary Assessment Report

(2020) figures.

* The groundwater elevation at AOI01-01 appears to be an anomaly with respect to the other wells and therefore was not included in the contour.
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Figure 2-5

Groundwater Elevations - April 2022

!(

!(

!(

!(

!(

Former AASF

Clam Shell

Hangars

Flight Line

- Apron

Main Hangar

AOI 2 Concrete Pond

AOI 1

Concrete Pond

AOI02-09

33.93

AOI02-10

36.76

AOI01-07

35.3

AOI01-08

34.35

AASF-02

14.8*

36

35

34

3

0 400

Feet

Data Sources: 

ESRI 2020

AECOM 2020

Date:............October 2022

Prepared By:.................WSP

Prepared For:.............USACE

)

LA

Selser Canal

Facility Data

Facility Boundary

Area of Interest (AOI)

Potential PFAS

Release Site

Hydrology/Hydrogeology

Groundwater Elevation Contour Interval (1 foot)

Surface Water Flow Direction

Inferred Shallow Groundwater Flow Direction

River/Stream

Water Body

Sample Location

!( Soil Boring and Temporary

Monotoring Well

* The groundwater elevation at AASF-02 appears to be an anomaly with respect to the other wells and therefore was not included in the contour.
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Figure 2-6

Surface Water Features

Ponchatoula

Creek

Chappepeela

Creek

Selsers Creek

Skulls

Creek-Tangipahoa

River

Ponchatoula

Creek

Sweetwater

Creek-Tangipahoa

River

East Ponchatoula

Creek-Ponchatoula

Creek

BigBr

Selsers Crk

Tangipahoa Riv

Bell Br

Brushy Br

Ponchatoula Crk

Ponchatoula Crk

Selsers Crk

Selser Cnl

East Ponchatoula Crk

Skulls

Crk

3

Data Sources: 

ESRI 2020

AECOM 2020

Date:.........................October 2022

Prepared By:........................WSP

Prepared For:....................USACE

)

LA

Selser Cnl

Facility Data Hydrology/Hydrogeology

0 500

Feet

0 1

Miles

Facility Boundary 

Surface Water Flow Direction

River/Stream

Water Body

Watershed
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3. SUMMARY OF AREAS OF INTEREST

The PA evaluated areas where PFAS-containing materials may have been used, stored, disposed, 

or released historically. Based on the PA findings, two potential release areas were identified at 

Hammond AASF #1 and designated as: AOI 1 C12 Hangar and AOI 2 Main Hangar and FlightLine Apron. The AOIs are shown on Figure 3-1. 

3.1 AOI 1 – C12 HANGAR

AOI 1 houses C12 aircraft maintenance operations. The geographic coordinates of the 

approximate center of the building are 30°31’31.4’’N; 90°24’57.2’’W. According to the PA 

report, the C12 Hangar was constructed between 2007 and 2009 and is charged with a 

Chemguard AFFF suppression deluge system with a 441-gallon-capacity tank. The system is

manually operated by a hose inside the hangar, and according to the ARNG the AFFF storage

tank is located in an adjacent room (#15) within the C12 Hangar (AECOM, 2020). The ARNG 

also indicated a 36-gallon fire suppression tank is located against a wall within the hangar. 

Every two years, a “full flow” test of the system is conducted using a replacement 

environmentally friendly foam that is not AFFF. Further details regarding this replacement 

foam were not able to be gathered during the PA. During these tests, the replacement foam flows

through the system in a contained loop so that no foam is released to drains or the environment. It 

is unknown whether an initial acceptance test of the suppression system was conducted, which 

may have left behind residual PFAS (AECOM, 2020). 

There have been no reported releases of the AFFF suppression system in the C12 Hangar. 

Evidence of slight leaking was observed underneath the AFFF tank in the utility room. A drip

pan was staged underneath the tank. According to information obtained during the PA, the leak 

is intermittent, the AFFF tank has not leaked to the extent of needing to be refilled, and the drip 

pan has never been full to the point of needing to be emptied. During the PA Facility visit, AFFF 

residue was observed in the drip pans. The utility room has a concrete floor, and no floor drains 

were observed (AECOM, 2020). 

3.2 AOI 2 – MAIN HANGAR AND FLIGHT LINE-APRON

AOI 2 houses helicopter maintenance operations. The geographic coordinates of the approximate 

center of the building are 30°31’31.4’’N; 90°24’57.2’’W. According to the PA report, the Main 

Hangar was constructed between 2007 and 2009 and is charged with a Buckeye 3% AFFF 

concentrate suppression deluge system fed by a 999-gallon tank (AECOM, 2020). 

It was reported that every two years a “full flow” test of the system is conducted using a 

replacement environmentally friendly foam which is not AFFF. Further details regarding this 

replacement foam were not able to be gathered during the PA. During these tests, the 

replacement foam is flowed through the system in a contained loop so that no foam is released to 

drains or the environment. It is unknown whether an initial acceptance test of the suppression 

system was conducted, which may have left behind residual PFAS (AECOM 2020). 

There have been no reported releases of the AFFF suppression system in the Main Hangar. 
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Evidence of slight leaking and corrosion/staining was observed underneath the tank on the 

concrete floor, underneath the feeder pipes to the hangar, and at the joints of the pipes. Drip

pans are in place to catch any leaks from the pipes. According to the PA report, the leaks are

intermittent and have never warranted a refill of the AFFF tank. The drip pans have never been

full to the point of needing to be emptied. The utility room has a concrete floor with no floor 

drains (AECOM, 2020). 

3.3 ADJACENT SOURCES

Eight potential off-facility sources of PFAS are adjacent to the Facility and are not under the 

control of the Louisiana ARNG (LAARNG). A description of each off-facility source is 

presented below and shown on Figure 3-1. 

3.3.1 Former AASF Clam Shell Hangars

The Former AASF Clam Shell Hangars were temporary structures that were operational from

2006 to 2010, adjacent to the eastern boundary of the current Hammond AASF #1 at an 

interpreted hydraulically cross-gradient to downgradient (shallow groundwater flow) direction. 

Four hangars appear on the aerial imagery. According to interviews with Facility personnel 

during the PA, approximately seven Tri-MaxTM 30 units were staged near the Clam Shell 

Hangars during this time. However, there were no reports of AFFF releases during this time. The 

City of Hammond Fire Chief reported knowledge of nozzle testing activities using water, not 

AFFF, at this location (AECOM, 2020). The Former AASF Clam Shell Hangars are not 

proposed for sampling under this SI. The National Guard Bureau issued a 01 February 2021 

Memorandum of Record for the Clam Shell Hangar facility that stated the location does not 

warrant further investigation in the SI phase. A copy of the Memorandum of Record was 

included in the Uniform Federal Policy Quality Assurance Project Plan (UFP-QAPP) Addendum 

(EA/Wood, 2021a). 

3.3.2 Aircraft Crash Site

During the PA, the City of Hammond Fire Chief reported knowledge of a fatal crash involving a 

single small aircraft on 14 October 2015, in which an unknown amount of AFFF was used 

during the emergency response. The crash location was identified to the northwest of the Facility 

at a distance of approximately 0.35-mile (AECOM, 2020) at an interpreted hydraulically 

upgradient (shallow groundwater flow) location. During this SI, one boring (AASF-01) was 

placed on the presumed upgradient end of the Hammond AASF #1 installation to assess potential 

impacts to soil and groundwater from the aircraft crash site.

3.3.3 405 South Oak Street

During the PA, the City of Hammond Fire Chief, a LAARNG Environmental Management 

representative, and the LAARNG Southern Region Environmental Coordinator reported 

occasional off-facility training with AFFF by Hammond Fire Department and LAARNG 

personnel. The amount of AFFF used and the frequency of these events is unknown. The training 

location was reported at 405 South Oak Street, approximately 3 miles southwest of the Facility 

boundary (AECOM, 2020) at an interpreted hydraulically cross-gradient to downgradient 
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(shallow groundwater flow) location. The 405 South Oak Street location was not sampled during 

this SI.

3.3.4 Nickel Plating

During the PA, the City of Hammond Fire Chief reported knowledge of chrome and nickelplating operations in the local area. During desktop review, a nickel-plating company, 

Electroless Nickel Plating, was identified approximately 5.45 miles to the southwest of the 

Facility (AECOM, 2020) at an interpreted hydraulically cross-gradient to downgradient (shallow 

groundwater flow) location. Electroless Nickel Plating was not sampled during this SI.

3.3.5 Chrome Plating

During desktop review, a chrome-plating company, The Chrome Shop, was identified 

approximately 11.9 miles to the southeast of the Facility (AECOM, 2020) at an interpreted 

hydraulically downgradient (shallow groundwater flow) location. The Chrome Shop was not 

sampled during this SI. 

3.3.6 Hammond Airport U.S. Customs Building

During the interviews conducted for the PA, LAARNG Environmental Management personnel 

reported that the U.S. Customs Building at the Hammond Regional Airport had an AFFFcharged fire suppression system. U.S. Customs personnel were not able to provide further 

information. The building is located approximately 0.62 mile to the southwest of the Facility at 

an interpreted hydraulically cross-gradient to downgradient (shallow groundwater flow) location. 

No information was gathered during the PA about potential PFAS presence or use at the 

Hammond Regional Airport, other than at the U.S. Customs Building (AECOM, 2020). The 

Hammond Airport U.S. Customs Building is considered an area with no suspected release and 

was not sampled during this SI. 

3.3.7 Hammond Fire Station 

The Hammond Fire Station has bulk storage of AFFF and houses firetrucks that hold AFFF. 

Information on the amount and type of AFFF stored at the station was not obtained during the 

PA. There were no reported leaks, spills, or releases of AFFF at the Hammond Fire Station. The 

building is located approximately 0.54 mile to the south of the Facility (AECOM, 2020) at an 

interpreted hydraulically cross-gradient to downgradient (shallow groundwater flow) location. 

The Hammond Fire Station is considered an area with no suspected release and was not sampled 

during this SI.

3.3.8 City of Hammond Water and Sewer

Municipal sewer and wastewater treatment facilities have the potential to receive PFAS from any 

source within the treatment district. The City of Hammond Water and Sewer maintenance 

facility is located approximately 0.95 mile southwest of the Facility at an interpreted 

hydraulically cross-gradient to downgradient (shallow groundwater flow) location, however, no 

information regarding treatment or discharge of wastewater by the City of Hammond was 
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gathered during the PA (AECOM, 2020). The City of Hammond Water and Sewer facility is 

considered an area with no suspected release and was not sampled during this SI.
Army National Guard Site Inspections

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Figure 3-1

Areas of Interest

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Hammond

Airport U.S.

Customs Building

City of Hammond

Water and

Sewer Facility

Former AASF

Clam Shell

Hangars

Airfield

Crash Site

Flight

Line -

Apron

Main Hangar

AOI 2

Concrete Pond

AOI 1

Concrete Pond

Drainage Pond

Selser Canal

Skulls Crk

Ponchatoula Crk

Data Sources: 

ESRI 2020

AECOM 2020

Date:....November 2022

Prepared By:........WSP

Prepared For:.....USACE

)

LA

Facility Data

Area of Interest

(AOI)

Facility Boundary

Potential PFAS

Release Site

No Suspected

Release

Well Type

&( Commercial Public

Supply Well

&( Domestic Well

&: Industrial Well

&: Irrigiation Well

A?@ Monitoring Well

0 0.5

Miles

Note: Certain features digitized from

georeferenced AECOM Preliminary

Assessment Report (2020) figures.

3

Inferred Shallow

Groundwater Flow Direction

(based on Preliminary

Assessment)

Hydrology/Hydrogeology

Inferred Shallow Groundwater

Flow Direction (based on April

2022 Site Inspection Event)

Surface Water Flow Direction

Inferred Shallow Groundwater

Flow Direction (based on August

2021 Site Inspection Event)

River/Stream

Water Body
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4. PROJECT DATA QUALITY OBJECTIVES

As identified during the data quality objective (DQO) process and outlined in the SI UFP-QAPP 

Addendum (EA/Wood, 2021a), the objective of the SI is to identify whether there has been a 

release to the environment at the AOIs identified in the PA. For each AOI, ARNG determines if 

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

whether no further action is warranted. This SI evaluated groundwater and soil for the presence 

or absence of relevant compounds at each of the sampled AOIs.

4.1 PROBLEM STATEMENT

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

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

are presented in Section 6.1 of this report. 

4.2 INFORMATION INPUTS

Primary information inputs for the SI include the following:

• The PA report for Hammond AASF #1 (AECOM, 2020);

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

accordance with the site-specific UFP-QAPP Addendum (EA/Wood, 2021a) and

Supplemental UFP-QAPP Addendum (EA/Wood, 2022); and

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

parameters measured at the time of sampling.

4.3 STUDY BOUNDARIES

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

The scope of the SI was bounded vertically by the depth of temporary monitoring wells installed 

within groundwater, where encountered (maximum depth of 32 feet bgs). Off-site sampling was 

not included in the scope of this SI. If future off-site 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 earliest available time field 

resources were available to complete the study.

4.4 ANALYTICAL APPROACH

Samples were analyzed by Eurofins, accredited under the Department of Defense (DoD) 

Environmental Laboratory Accreditation Program (Accreditation Number 1.01) and the National 

Environmental Laboratory Accreditation Program (Certificate Number 021). Data were 

compared to applicable SLs within this document and decision rules as defined in the UFPQAPP Addendum (EA/Wood, 2021a). 
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4.5 DATA USABILITY ASSESSMENT

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

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

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

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

data have met installation specific DQOs. Both sampling and analytical activities are considered 

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

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

The environmental data collected during the SI were found to be acceptable and usable for this 

SI evaluation with the qualifications documented in the Data Usability Assessment and its 

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

requirements of the UFP-QAPP Addendum (EA/Wood, 2021a). 
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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 was 

implemented in accordance with the following approved documents. 

• Final Preliminary Assessment Report, Army Aviation Support Facility #1,

Hammond, Louisiana, dated July 2020 (AECOM, 2020)

• Final Programmatic Uniform Federal Policy-Quality Assurance Project Plan,

Site Inspections for Per- and Polyfluoroalkyl Substances Impacted Sites, ARNG

Installations, Nationwide, dated December 2020 (EA, 2020)

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

Addendum, Army Aviation Support Facility #1, Hammond, Louisiana, Per- and

Polyfluoroalkyl Substances Impacted Sites, ARNG Installations, Nationwide,

dated July 2021 (EA/Wood, 2021a)

• Accident Prevention Plan, Programmatic Uniform Federal Policy Quality

Assurance Project Plan, Site Inspections for Per- and Polyfluoroalkyl Substances

Impacted Sites, ARNG Installations, Nationwide, Revision 1, dated November

2021 (EA, 2021)

• Final Accident Prevention Plan/Site Safety and Health Plan, Hammond Army

Aviation Support Facility #1, Louisiana, Site Inspections for Per- and

Polyfluoroalkyl Substances Impacted Sites, ARNG Installations, Nationwide,

Revision 1, dated April 2021 (EA/Wood, 2021b).

The SI field activities were conducted in two field events. Initial SI field activities were 

conducted from 9 through 13 August 2021. Following the first field event, it was 

determined that additional investigation activities were warranted to address certain data 

gaps following the initial investigation, and therefore supplemental SI field activities 

were performed from 19 through 22 and 26 April 2022. SI activities consisted of utility 

clearance, DPT boring and soil sample collection, temporary monitoring well installation, 

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

in accordance with the UFP-QAPP Addendum (EA/Wood, 2021a), and Supplemental 

UFP-QAPP Addendum (EA/Wood, 2022) except as noted in Section 5.8. 

The following samples were collected during the SI and analyzed for 24 compounds via 

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

Version 5.3 Table B-15 to fulfill the project DQOs:

• Thirty (30) soil samples from eleven (11) locations (soil borings);

• Ten (10) grab groundwater samples from temporary well locations;

• Twenty-three (23) quality assurance/quality control (QA/QC) samples.
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Figure 5-1 provides the sample locations for all media across the Facility. Table 5-1

presents the list of samples collected for each medium. 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, land survey data are provided in Appendix B3, and a Non-Conformance 

Report is provided in Appendix B4. Additionally, a photographic log of field activities is 

provided in Appendix C. 

5.1 PRE-INVESTIGATION ACTIVITIES

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

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

water. Details of these activities are presented below. 

5.1.1 Technical Project Planning

The U.S. Army Corps of Engineers (USACE) TPP Process, Engineer Manual 200-1-2 (DA 

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

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

The process encourages stakeholder involvement in the SI, beginning with defining overall 

project objectives, including DQOs, and formulating a sampling approach to address the AOIs 

identified in the PA. 

A combined TPP Meeting 1 and 2 was held on 21 May 2021, prior to the initial SI field 

activities. Meeting minutes are provided in Appendix D. The combined TPP Meeting 1 and 2 

was conducted in general accordance with Engineer Manual 200-1-2 (DA, 2016). The 

stakeholders for this SI included 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 UFP-QAPP Addendum (EA/Wood 

2021a). A separate planning meeting was held on 31 March 2022, prior to the supplemental SI 

field activities. Meeting minutes for this event are provided in Appendix D. 

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

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

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

5.1.2 Utility Clearance

WSP USA Environment & Infrastructure, Inc. (WSP), formerly doing business as Wood 

Environment & Infrastructure Solutions, Inc., contacted the Louisiana 811 Utility Notification 

Center to notify them of intrusive work at the Facility. As part of the supplemental SI event WSP 

contracted Blood Hound, a private utility location service, to perform utility clearance at the 

Facility. Utility clearance was performed at each of the proposed supplemental boring locations 

on 12 April 2022 with input from the WSP field team. General locating services and groundpenetrating radar were used to complete the clearance. Additionally, the first 5 feet of each 
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boring were pre-cleared by WSP’s drilling subcontractor, Walker-Hill Environmental, Inc., using 

a hand auger to verify utility clearance in 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 

PFAS-free prior to the start of field activities. Samples from a potable water source at the C12 

Hangar, were collected on 06 July 2021 (prior to mobilization for the initial SI) and on 02 March 

2022 (prior to mobilization for the supplemental SI) and analyzed for PFAS by LC/MS/MS 

compliant with QSM 5.3 Table B-15 (DoD, 2020). The results of the samples of the potable 

water source used for decontamination of drilling equipment during the SI are provided in 

Appendix E. A discussion of the results is presented in the Data Usability Assessment 

(Appendix A).

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 appendix to the Programmatic 

UFP-QAPP (EA 2020). 

5.2 SOIL BORINGS AND SOIL SAMPLING

Soil samples were collected via direct-push technology (DPT) drilling methods in accordance 

with Standard Operating Procedure 047, Direct-Push Technology Sampling (EA 2014). A 

Geoprobe® 7822DT dual-tube sampling system was used to collect continuous soil cores to the 

target depth. A hand auger was used to collect soil from the top 5 feet of the boring in 

compliance with utility clearance procedures. The soil boring locations are shown on Figure 5-1, 

and boring sample depths are provided in Table 5-1. Certain boring locations were adjusted 

within a 50-feet offset for reasons including drill rig access and utility avoidance. 

Three discrete soil samples were planned to be collected for chemical analysis from each soil 

boring: one sample at the surface (0 to 2 feet bgs) and two subsurface soil samples. One 

subsurface soil sample was collected approximately 1 foot above the groundwater table, and one 

subsurface sample was collected at the mid-point between the surface and the groundwater table 

(not to exceed 15 feet bgs). However, the UFP-QAPP Addendum (EA/Wood, 2021a) specified 

only two samples be collected if refusal was encountered at 6 feet bgs or shallower. Three soil 

samples were collected from each boring with the following exceptions: 

• AOI02-03: Only surface soil was collected due to refusal at 2 feet bgs.

• ASSF-01-SB: Only two soil samples were collected (0–2 feet bgs, 2–4 ft bgs) due to

encountering the uppermost water bearing zone at 3.4 feet bgs.

During drilling the top of the uppermost saturated zone was encountered at depths ranging from 

3.4 to 28 feet bgs during drilling. Following installation of temporary monitoring wells, the static 

groundwater depths ranged from 2.19 to 26.70 feet bgs (one temporary monitoring well was dry 

after installation). Total boring completion depths, to accommodate temporary well installation, 

ranged from 8.5 to 32 feet bgs. A separate boring (AOI02-03) was terminated at 2 feet bgs, 
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above the uppermost saturated zone, due to drilling refusal encountered from a large subsurface 

obstruction. 

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

the Unified Soil Classification System. A photoionization detector was used to screen the 

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

and measurements were recorded on sampling forms (Appendix B2) and in a non-treated field 

logbook. Depth interval, recovery thickness, photoionization detector concentrations, moisture, 

relative density, Munsell color, and Unified Soil Classification System texture were recorded. 

The boring logs are provided in Appendix F. 

Soil encountered during SI activities included silts, sands, clays, and mixtures of such. Bedrock 

was not encountered during the investigation. These observations are consistent with the 

understood depositional environment of the region. 

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

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

transported via FedEx under standard chain-of-custody procedures to the laboratory and 

analyzed for PFAS (LC/MS/MS compliant with QSM Version 5.3 Table B-15), total organic 

carbon (TOC) (USEPA Method 9060A), pH (USEPA Method 9045D), and grain size (ASTM 

Method D-422) in accordance with the UFP-QAPP Addendum (EA/Wood, 2021a). 

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

the accompanying samples. Matrix spikes/matrix spike duplicates were collected at a rate of 5% 

and analyzed for the same parameters as the accompanying samples. In instances when nondedicated sampling equipment was used, such as a hand auger for the shallow soil samples, one 

EB was collected per day and analyzed for the same parameters as the soil samples. A 

temperature blank was placed in each cooler for use in confirming that samples were preserved 

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

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

sampling and surveying in accordance with the UFP-QAPP Addendum (EA/Wood, 2021a). 

After removal of the casings, boreholes were abandoned using bentonite chips. Borings were 

installed in grass areas to avoid disturbing concrete or asphalt surfaces. 

5.3 TEMPORARY WELL INSTALLATION AND GROUNDWATER GRAB 

SAMPLING

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

the borehole was advanced to the desired depth, a temporary well was constructed of a 4-foot, 5-

foot, or 10-foot section of 1-inch Schedule 40 polyvinyl chloride (PVC) screen with sufficient 

casing to reach the ground surface. New PVC pipe and screen were used at each location to 

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

provided in Table 5-2. 

Groundwater samples were collected using either a peristaltic pump with PFAS-free HDPE 

tubing or a PFAS-free bailer, after a period of time following well installation to allow 
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groundwater to infiltrate and recharge the temporary well intervals. The temporary wells were 

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

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

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

field sampling form (Appendix B2) before each grab sample was collected in a separate 

container. Additionally, a subsample of each groundwater sample was collected in a separate 

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 sample was collected in laboratory-supplied PFAS-free HDPE bottles and labeled using a 

PFAS-free marker or pen. Samples were packaged on ice and transported via Federal Express 

under standard chain-of-custody procedures to the laboratory and analyzed for PFAS by 

LC/MS/MS compliant with QSM Version 5.3 Table B-15 (DoD 2020) in accordance with the 

UFP-QAPP Addendum (EA/Wood, 2021a). 

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

the accompanying samples. Matrix spikes/matrix spike duplicates were collected at a rate of 5% 

and analyzed for the same parameters as the accompanying samples. Six field blank samples 

were collected in accordance with the UFP-QAPP Addendum (EA/Wood, 2021a) and 

Supplemental UFP-QAPP Addendum (EA/Wood, 2022). In instances when non-dedicated 

sampling equipment was used, such as a peristaltic pump, one equipment black per day was 

collected and analyzed for the same parameters as the groundwater samples. A temperature blank 

was placed in each cooler for use in confirming that samples were preserved at or below 6°C 

during shipment. 

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

accordance with the UFP-QAPP Addendum (EA/Wood, 2021a) by removing the PVC and 

backfilling the hole with bentonite chips. 

5.4 SYNOPTIC WATER LEVEL MEASUREMENTS

Synoptic groundwater gauging events were performed on 11 August 2021 during the initial SI 

field event and on 22 April 2022 during the supplemental SI field event. Groundwater elevation 

measurements were collected from the temporary monitoring wells installed during each field 

event. Water level measurements were taken from the survey mark on the northern side of the 

well casing. Groundwater elevation data are provided in Table 5-3. The data from the initial SI 

sampling event indicated overall shallow groundwater flow to the southeast, while the data from 

the supplemental SI sampling event indicated overall groundwater flow to the northeast. 

Groundwater flow contour maps are provided as Figure 2-4 and Figure 2-5. 

5.5 SURVEYING

The northern side of each new temporary well casing was surveyed using RTK Global 

Positioning System network with solutions provided by the Louisiana State University Center for 

Geomatics Real Time Network. Positions were collected in the applicable Universal Transverse 

Mercator zone projection with World Geodetic System 1984 datum (horizontal) and North 
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American Vertical Datum 1988 (vertical). Surveying data were collected on 12 August 2021 and 

21 April 2022 and 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. IDW generated during the SI is considered non-hazardous waste and was 

managed in accordance with the UFP-QAPP Addendum (EA/Wood, 2021a). 

Soil IDW (i.e., soil cuttings) generated during the SI activities were placed in 5-gallon buckets, 

labeled, and placed inside the Hammond AASF #1 hazmat shed at the Facility. The soil IDW 

was not sampled and assumes the characteristics of the associated soil samples collected from 

that source location.

Liquid IDW (i.e., purge water, development water, and decontamination fluids) generated during 

the SI activities were placed separately in 5-gallon buckets, labeled, and placed inside the 

Hammond AASF #1 hazmat shed at the Facility. The liquid IDW was not sampled and assumes 

the characteristics of the associated soil or groundwater samples collected from that source 

location. 

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 Resource Conservation and 

Recovery Act Subtitle C landfill. The IDW disposal is being managed by EA as a separate task 

under the same contract. Specifics on the disposal of solid and liquid IDW will be addressed in 

an IDW Disposal 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 off-site as municipal waste. 

5.7 LABORATORY ANALYTICAL METHODS

Samples were analyzed by LC/MS/MS, compliant with QSM Version 5.3 Table B-15, at 

Eurofins in Lancaster, Pennsylvania, a DoD Environmental Laboratory Accreditation Program 

and National Environmental Laboratory Accreditation Program-certified laboratory. 

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

9045D, and grain size using ASTM Method D-422. 

5.8 DEVIATIONS FROM THE SI UFP-QAPP ADDENDUM AND SUPPLEMENTAL 

UFP-QAPP ADDENDUM

Deviations from the UFP-QAPP Addendum (EA/Wood, 2021a) and Supplemental UFP-QAPP 

Addendum (EA/Wood, 2022) occurred based on conditions encountered during field activities. 

These deviations were discussed between EA Engineering, Science, and Technology, Inc., PBC, 

WSP, the ARNG, and/or USACE, as applicable, and are noted below: 
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• Boring location AOI02-03 encountered refusal approximately 2 feet bgs, both in the

original drilling location and in numerous off-set locations. A subsequent review of

historical aerial images revealed that a large structure was previously located in this area,

and therefore the refusal encountered was likely the remaining concrete slab. The former

structure was large enough that to offset beyond the footprint of the slab would require

drilling in an area that would not capture potential PFAS releases near the intended

location and would be beyond the 100-foot radius around the original location that was

cleared for utilities. Because of the encountered refusal only one soil sample was

collected at this location.

• At location AOI01-02, apparent groundwater was observed during drilling and a

temporary monitoring well was subsequently installed; however, the well remained dry

for the duration of the SI field efforts. Therefore, a groundwater sample was not collected

from this location.

• Soil samples were to be placed into one 4‐ounce glass container (% moisture analysis)

and two 4.5‐ounce plastic containers (one for a PFAS field screen, and one for PFAS

analysis). Four of the 18 soil samples inadvertently were placed into glass containers

only. The glass container lids contained a Teflon liner, a potential PFAS source for cross‐

contamination, and certain PFAS compounds have the capacity to sorb, at varying

degrees, to glass surfaces. Following several discussions with the laboratory, ARNG and

USACE, the collective decision was to proceed with the analysis. EA/WSP issued a NonConformance Report (Appendix B4) to the USACE on 25 August 2021. The analytical

results from the SI revealed that all soil PFAS analytical results, including those analyzed

from plastic and glass containers, were either not detected or were detected at very low

concentrations. Therefore, the non-conformance did not have an obvious impact on the

soil sample results.

• Three surface soil samples were collected at intervals from 0 to 4 feet bgs rather than 0 to

2 feet bgs for which the residential scenario is applied. Because these samples were

collected as surface soil samples and the bulk of the sample likely was obtained between

0 and 2 feet bgs, the results from these samples were compared to the residential scenario

for direct ingestion of contaminated soil.

• One temporary monitoring well screen installed was a 4-foot section due to shallow

groundwater encountered, while certain other monitoring well screens installed were 10-

foot sections due to perceived low-yielding groundwater formations encountered.
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Table 5-1. Site Inspection Samples by Medium

Hammond AASF #1, Louisiana

Site Inspection Report

Sample Identification Sample Collection Date

Sample Depth 

(feet bgs) PFAS1 TOC2 pH3 Grain Size4 Comments

Soil Samples

AOI01-01-SB-(0-4) 10 August 2021 0-4 X X X X

AOI01-01-SB-(4-5) 10 August 2021 4-5 X

AOI01-01-SB-(8-9) 10 August 2021 8-9 X

AOI01-02-SB-(0-4) 10 August 2021 0-4 X

AOI01-02-SB-(7-8) 10 August 2021 7-8 X

AOI01-02-SB-(16-17) 10 August 2021 16-17 X

AOI02-03-SB-(0-1) 10 August 2021 0-1 X

AOI02-04-SB-(0-2) 09 August 2021 0-2 X X X X

AOI02-04-SB-(5-6) 10 August 2021 5-6 X

AOI02-04-SB-(11-12) 10 August 2021 11-12 X

AOI02-05-SB-(0-2) 10 August 2021 0-2 X

AOI02-05-SB-(10-12) 10 August 2021 10-12 X

AOI02-05-SB-(18-20) 10 August 2021 18-20 X MS/MSD

AOI02-06-SB-(0-4) 11 August 2021 0-4 X

AOI02-06-SB-(10-12) 11 August 2021 10-12 X

AOI02-06-SB-(20-22) 11 August 2021 20-22 X

ASSF-01-SB-(0-2) 09 August 2021 0-2 X

AASF-01-SB-(2-4) 09 August 2021 2-4 X

DUP01-SB 10 August 2021 11-12 X AOI02-04-SB-(11-12)

DUP02-SB 10 August 2021 7-8 X AOI01-02-SB-(7-8)

FD 11 August 2021 0-4 X X AOI02-06-SB-(0-4)

AOI01-07-SB-0-2 19 April 2022 0-2 X MS/MSD

AOI01-07-SB-13-15 19 April 2022 13-15 X

AOI01-07-SB-26-27 19 April 2022 26-27 X

AOI01-08-SB-0-2 20 April 2022 0-2 X

AOI01-08-SB-11-12 20 April 2022 11-12 X

AOI01-08-SB-22-23 20 April 2022 22-23 X

AOI02-09-SB-0-2 19 April 2022 0-2 X

AOI02-09-SB-8-10 19 April 2022 8-10 X

AOI02-09-SB-20-21 19 April 2022 20-21 X

AOI02-10-SB-0-2 21 April 2022 0-2 X
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Sample Identification Sample Collection Date

Sample Depth 

(feet bgs) PFAS1 TOC2 pH3 Grain Size4 Comments

Soil Samples (continued)

AOI02-10-SB-4-5 20 April 2022 4-5 X

AOI02-10-SB-7-8 20 April 2022 7-8 X

FD-01-041922 19 April 2022 0-2 X AOI02-09-SB-0-2

FD-03-042122 21 April 2022 0-2 X AOI02-10-SB-0-2

Groundwater Samples

AOI01-01-GW 13 August 2021 X

AOI02-04-GW 12 August 2021 X

AOI02-05-GW 13 August 2021 X MS/MSD

AOI02-06-GW 12 August 2021 X

AASF-01-GW 12 August 2021 X

DUP01-GW 13 August 2021 X AOI02-05-GW

AOI01-07-GW 20 April 2022 X MS/MSD

AOI01-08-GW 22 April 2022 X

AOI02-09-GW 20 April 2022 X

AOI02-10-GW 21 April 2022 X

AASF-02-GW 26 April 2022 X

FD-02-042022 20 April 2022 X AOI01-GW-07

Blank Samples

HAASF-EB-01 09 August 2021 X

HAASF-EB-02 10 August 2021 X

HAASF-EB-03 11 August 2021 X

HAASF-EB-04 12 August 2021 X

HAASF-EB-05 13 August 2021 X

HAASF-FB-01 12 August 2021 X

HAASF-FB-02 13 August 2021 X

HAASF-EB-01 20 April 2022 X

HAASF2-EB-03 21 April 2022 X

HAASF2-EB-04 21 April 2022 X

HAASF2-EB-05 22 April 2022 X

HAASF02-EB-06 26 April 2022 X

HAASF2-FB-02 22 April 2022 X

HAASF2-FB-03 22 April 2022 X
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Sample Identification Sample Collection Date

Sample Depth 

(feet bgs) PFAS1 TOC2 pH3 Grain Size4 Comments

Blank Samples (continued)

HAASF2-FB-04 22 April 2022 X

HAASF2-FB-05 26 April 2022 X

Notes:

1. PFAS were analyzed by LC/MS/MS compliant with QSM 5.3 Table B-15.

2. TOC was analyzed using USEPA Method 9060A.

3. pH was analyzed using USEPA Method 9045D.

4. Grain size was analyzed using ASTM International Method D422

Abbreviations:

AASF = Army Aviation Support Facility

AOI = Area of Interest

bgs = below ground surface

DUP = duplicate

EB = equipment blank

FB = field blank

FD = field duplicate

GW = groundwater

HAASF = Hammond Army Aviation Support Facility

MS/MSD = matrix spike/ matrix spike duplicate

PFAS = per- and polyfluoroalkyl substances

SB = soil boring

TOC = total organic carbon

USEPA = United States Environmental Protection Agency
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Table 5-2. Soil Boring Depths and Temporary Well Screen Intervals

Hammond AASF #1, Louisiana

Site Inspection Report

Area of Interest Boring Location

Soil Boring Depth

(feet bgs)

Temporary Well Screen Interval

(feet bgs)

1 

AOI01-01 16 6-16

AOI01-02 20 10–20

AOI01-07 32 26–31

AOI01-08 28 22–27

2 

AOI02-03 2 NA

AOI02-04 12 2–12

AOI02-05 20 10–20

AOI02-06 22 12–22

AOI02-09 28 20–25

AOI02-10 12 7–12

Boundary AASF-01 8.5 0–4

AASF-02 32 27–32

Abbreviations:

bgs = below ground surface

NA = not applicable (well not installed)
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Table 5-3. Groundwater Elevation 

Hammond AASF #1, Louisiana

Site Inspection Report

Date Monitoring Well 

ID

Top of Casing Elevation

(feet NAVD88)

Depth to Water

(feet btoc)

Depth to 

Water

(feet bgs)

Groundwater Elevation

(feet NAVD 88)

August 2021

AOI01-01 40.79 8.5 8.11 32.29

AOI01-02 42.08 DRY DRY DRY

AOI02-04 40.21 2.5 2.19 37.71

AOI02-05 40.61 3.5 3.09 37.11

AOI02-06 40.81 6.2 5.69 34.61

AASF-01 41.48 3.1 2.42 38.38

April 2022

AOI01-07 46.21 10.91 10.90 35.30

AOI01-08 43.33 8.98 6.15 35.35

AOI02-09 39.61 5.68 5.67 33.93

AOI02-10 42.11 5.35 3.04 36.76

AASF-02 43.98 29.18 26.70 14.8

Abbreviations:

bgs = below ground surface

btoc = below top of casing

NAVD88 = North American Vertical Datum 1988
Army National Guard Site Inspections

Site Inspection Report

Army Aviation Support Facility #1

Hammond, Louisiana

Figure 5-1

Site Inspection Sample Locations

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

Flight Line - Apron

Former AASF 

Clam Shell 

Hangars

Main Hangar

Drainage Pond

AOI 2

AOI 1

Concrete Pond

Concrete Pond

AOI02-06

AOI02-03

AOI02-05

AOI02-04

AOI01-02

AOI01-01 AASF-01

AO102-09

AO102-10

AASF-02

AO101-07

AO101-08

3

0 400

Feet

Date:...................November 2022

Prepared By:.........................WSP

Prepared For:....................USACE

)

LA

Selser Canal

Facility Data

Area of Interest (AOI)

Facility Boundary

Potential PFAS

Release Site

Sample Location

!( Soil Boring and

Temporary Well

Location

!( Temporary

Monitoring Well

Hydrology/Hydrogeology

Inferred Shallow Groundwater

Flow Direction (based on April

2022 Site Inspection Event)

Surface Water Flow Direction

River/Stream

Water Body

Inferred Shallow Groundwater

Flow Direction (based on August

2021 Site Inspection Event)

Data Sources: 

ESRI 2020

AECOM 2020
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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 Sections 6.3

and 6.4. Table 6-2 through Table 6-5 present results in soil or groundwater for the relevant 

compounds. Tables that contain all results are provided in Appendix G, and the laboratory 

reports are provided in Appendix E. 

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 the OSD memorandum (Assistant Secretary of 

Defense, 2022). The ARNG program under which this SI was performed follows this DoD 

policy. Should the maximum site concentration for sampled media exceed the SLs established in 

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

established in the OSD memorandum apply to the five compounds presented on Table 6-1. 

Table 6-1. Screening Levels for Soil and Groundwater

Analyte2

Residential 

Soil

(0–2 feet bgs)

(μg/kg)1

Industrial/Commercial 

Composite Worker 

Soil

(2–15 feet bgs)

(μg/kg)1

Tap Water 

(Groundwater)

(ng/L)1

PFOA 19 250 6

PFOS 13 160 4

PFBS 1,900 25,000 601

PFHxS 130 1,600 39

PFNA 19 250 6

Notes:

1. Assistant Secretary of Defense, July 2022. Risk Based Screening Levels in Groundwater and Soil using

United States Environmental Protection Agency’s (USEPA’s) Regional Screening Level Calculator.

Hazard Quotient (HQ) = 0.1. May 2022.

2. Screening values for HFPO-DA were established after site inspection planning and execution and thus

HFPO-DA is not included as an analyte. Future CERCLA phases will include HFPO-DA if warranted.

Abbreviations:

mg/kg = microgram(s) per kilogram

CERCLA = Comprehensive Environmental Response, Compensation, and Liability Act

HFPO-DA hexafluoropropylene oxide dimer acid

ng/L = nanogram(s) per liter

PFBS = perfluorobutanesulfonic acid

PFHxS = perfluorohexanesulfonic acid

PFNA = perfluorononanoic acid

PFOA = perfluorooctanoic acid

PFOS = perfluorooctanesulfonic acid

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 
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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 G

contains the results of the TOC, pH, and grain size sampling. TOC in the samples collected at 

AOI 1 and AOI 2 were 7,800 and 520 milligrams per kilogram, respectively. The grain size 

results correlate with the silts, sands, and clays observed during drilling activities. Soil pH in the 

samples collected at AOI 1 and AOI 2 were 6.2 and 5.4 Standard Units. 

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

appropriate, to assess fate and transport. According to the Interstate Technology Regulatory 

Council, 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, although 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 the C12 Hangar and downstream concrete-lined pond. The soil and 

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

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

6.3.1 AOI 1 Soil Analytical Results

Soil samples were collected from five boring locations associated with AOI 1 during the SI. 

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

6-4 summarize the soil results.

Surface soil (0 to 2 feet bgs) was sampled from boring locations AOI01-01 (just south of the C12 

Hangar), AOI01-02, AOI01-07 (southeast of the C12 Hangar), AOI01-08 (just south of the 

concrete pond that receives drainage from the C12 Hangar area), and ASSF-01 (presumed 

upgradient location to assess potential soil impacts from the 2015 aircraft crash site). Soil was 

also sampled from shallow subsurface soil (2 to 15 feet bgs) from boring locations AOI01-01, 

AOI01-02, AOI01-07, AOI01-08, and AASF-01, and deep subsurface soil intervals (16 to 27 

feet bgs) from boring locations AOI01-02, AOI01-07, and AOI01-08. PFOA was detected in 

surface soil in one of five locations (AOI01-01) at a concentration (0.28 J micrograms per 

kilogram [μg/kg]) below its SL. PFOS, PFBS, PFHxS, and PFNA were not detected in the 

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

soil samples.

6.3.2 AOI 1 Groundwater Analytical Results 

Groundwater samples were collected from five temporary wells associated with AOI 1 during 

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

summarizes the groundwater results.

Groundwater was sampled from temporary monitoring well locations AOI01-01 (just south of 

the C12 Hangar), AOI01-07 and AOI01-08 (just south of the concrete pond that receives 

drainage from the C12 Hangar area), and AASF-01 and AASF-02 (presumed upgradient 

locations to assess potential impacts to groundwater from the 2015 aircraft crash site). PFOA 

was detected in AOI01-01 and AASF-01 at concentrations of 31 nanograms per liter (ng/L) and 

17 ng/L, respectively, exceeding its SL. PFOS was detected in AASF-01 (2.1 J ng/L) and AASF02 (0.85 ng/L) below the SL, while PFNA was detected in AASF-01 at a concentration (3.6 

ng/L) below the SL. PFBS and PFHxS were not detected in the groundwater samples. 

6.3.3 Conclusions

Based on the results of the SI, PFOA was detected in soil at AOI01-01 at a concentration below 

its SL and in groundwater at AOI01-01 and AASF-01 at concentrations above its SL. Based on 

the exceedance of the SLs in groundwater, further evaluation at AOI 1 is warranted.

6.4 AOI 2 

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

AOI 2, which includes the Main Hangar, the associated Flight Line-Apron, a downstream 

concrete-lined pond, and a retention basin. The soil and groundwater results are summarized in 

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

Figure 6-7. 

6.4.1 AOI 2 Soil Analytical Results

Soil samples were collected from four boring locations associated with AOI 2 during the SI. 

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

6-4 summarize the soil results.

Surface soil (0 to 2 feet bgs) was sampled from boring locations AOI02-03 (southeast of the 

main hangar and flight line-apron), AOI02-04 (southwest of the flight line-apron), AOI02-05 

(southwest of the flight line-apron), AOI0-06 (near the southeast facility boundary), AOI02-09 

(southeast of the main hangar and flight line-apron), and AOI02-10 (southeast of the main 

hangar and flight line-apron). Soil was also sampled from shallow subsurface soil (5 to 12 feet 

bgs) and deep subsurface soil intervals (7 to 21 feet bgs) from boring locations AOI02-04, 

AOI02-05, AOI0-06, AOI02-09, and AOI02-10. 
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PFOA, PFOS, PFBS, PFHxS, and PFNA were not detected in any of the soil samples.

6.4.2 AOI 2 Groundwater Analytical Results 

Groundwater samples were collected from five temporary wells associated with AOI 2 during 

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

summarizes the groundwater results.

Groundwater was sampled from temporary monitoring well locations AOI02-04 (southwest of 

the flight line-apron), AOI02-05 (southwest of the flight line-apron), AOI0-06 (near the 

southeast facility boundary), AOI02-09 (southeast of the main hangar and flight line-apron), and 

AOI02-10 (southeast of the main hangar and flight line-apron). PFOA, PFOS, PFBS, and PFHxS 

were detected at concentrations below their respective SLs. PFNA was not detected in the 

groundwater samples. PFOA was detected in one of the five wells sampled (AOI02-05) at a 

concentration of 1.1 J ng/L; PFOS was detected in one of the five wells (AOI02-05) at a 

concentration of 0.94 J ng/L [1.4 J ng/L in the duplicate sample]; PFBS was detected in two of 

the five wells sampled (AOI02-05 and AOI02-10) at concentrations ranging from 0.48 J ng/L to 

2.6 J ng/L; and PFHxS was detected in one of the five wells sampled (AOI02-05) at a 

concentration of 0.81 J ng/L [0.79 J ng/L in the duplicate sample]. 

6.4.3 Conclusions

Based on the results of the SI, PFOA, PFOS, PFBS, PFHxS, and PFNA were not detected in soil. 

PFOA, PFOS, PFBS, and PFHxS were detected in groundwater at concentrations below their 

respective SLs. Based on the lack of exceedances of the SLs in soil and groundwater, further 

evaluation at AOI 2 is not warranted. 
Table 6-2 

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

Site Inspection Report

Hammond AASF #1, Louisiana

Analyte OSD Screening Level1,2 Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result 

Soil, PFAS3 (μg/kg)

PFBS 1900 ND ND ND ND ND ND ND 

PFOA 19 0.28 J ND ND ND ND ND ND 

PFNA 19 ND ND ND ND ND ND ND PFHxS 130 ND ND ND ND ND ND ND PFOS 13 ND ND ND ND ND ND ND Gray Fill Detected concentration exceeded OSD Screening Level Chemical Abbreviations

PFBS Perfluorobutanesulfonic 

References PFHxS Perfluorohexanesulfonic 

PFNA Perfluorononanoic acid PFOS Perfluorooctanesulfonic PFOA Perfluorooctanoic acid 

2. The Screening Levels for soil are based on a residential scenario for direct ingestion of contaminated soil.3. PFAS by LC/MS/MS compliant with QSM Version 5.3 Table B-15 Acronyms and Abbreviations

* Surface soil sample interval extended beyond 2 ft bgs AASF Army Aviation Support F

AOI Area of Interest

Interpreted Qualifiers ft Feet

J = Estimated concentration LOD Limit of Detection

ND analyte not detected abovOSD Office of the Secretary oPFAS per- and polyfluoralkyl sQSM Quality Systems ManualQual interpreted qualifierμg/kg micrograms/kilogram

AOI02-03 AOI02

AOI02-03-SB-(0-1)

8/10/2021

1. Assistant Secretary of Defense. July 2022. Risk Based Screening Levels in Groundwater and Soil usingUnited States Environmental Protection Agency’s Regional Screening Level Calculator. Hazard Quotient(HQ)=0.1 . May 2022.

0-2 ft

4/19/2022

AOI01-08

AOI01-08-SB-0-2

0-2 ft

4/20/2022

AOI01-07

Sample Name AOI01-01-SB-(0-4) AOI01-07-SB-02 AOI02-04-

AOI01

Sample Date 8/13/2021

0-4 ft*

8/9/20

Depth 0-4 ft* 0-1 ft 0-2 

8/11/2021

Area of Interest 

Location ID AOI01-01 AOI01-02

AOI01-02-SB-(0-4)

Parent Sample ID

AASF-01

AASF-01-SB-(0-2)

0-2 ft

8/9/2021
Site Inspection Report 

Hammond AASF #1, Louisiana Version: FINAL

EA Engineering, Science, and Technology, Inc., PBC 6-6

This page intentionally left blank
Table 6‐3

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

Site Inspection Report

Hammond AASF #1, Louisiana

Analyte OSD Screening Level1, 2 Result Qual Result Qual Result Qual Result Qual Result 

Soil, PFAS3 (μg/kg) 4:2 Fluorotelomer sulfonate < U < U < U 

PFBS 25000 ND ND ND ND ND 

PFOA 250 ND ND ND ND ND 

PFNA 250 ND ND ND ND ND 

PFHxS 1600 ND ND ND ND ND 

PFOS 1600 ND ND ND ND ND 

Gray Fill Detected concentration exceeded OSD Screening Level Chemical 

PFBS 

References PFHxS 

PFNA PFOS PFOA 

2. The SL for soil is based on incidental ingestion of soil industrial/commercial worker >2 ft.3. PFAS by LC/MS/MS compliant with QSM Version 5.3 Table B-15 Acronym

AASF 

Interpreted Qualifiers AOI J = Estimated concentration ft 

LOD ND OSD PFAS QSM Qual μg/kg 

1. Assistant Secretary of Defense. July 2022. Risk Based Screening Levels in Groundwater and Soil using United States Environmental ProtectionAgency’s Regional Screening Level Calculator. Hazard Quotient (HQ)=0.1 . May 2022.

8/10/2021 8/10/2021 8/10/2021 8/10/2021 4/

4-5 ft 8-9 ft 7-8 ft 7-8 ft 1

AOI01-02-SB-(7-8)

AOI01-02 AOI01-02 A

AOI01-01-SB-(4-5) AOI01-01-SB-(8-9) AOI01-02-SB-(7-8) DUP02-SB AOI01-

AOI01-01 AOI01-01

Area of Interest AOI01

Location ID

Sample Name

Parent Sample ID

Depth

Sample Date
Table 6‐3

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

Site Inspection Report

Hammond AASF #1, Louisiana

Analyte OSD Screening Level1, 2 Result Qual Result Qual Result Qual Result Qual Result 

Soil, PFAS3 (μg/kg) 4:2 Fluorotelomer sulfonate < U < U < 

PFBS 25000 ND ND ND ND ND 

PFOA 250 ND ND ND ND ND 

PFNA 250 ND ND ND ND ND 

PFHxS 1600 ND ND ND ND ND 

PFOS 1600 ND ND ND ND ND 

Gray Fill Detected concentration exceeded OSD Screening Level Chemical 

PFBS 

References PFHxS 

PFNA PFOS PFOA 

2. The SL for soil is based on incidental ingestion of soil industrial/commercial worker >2 ft.3. PFAS by LC/MS/MS compliant with QSM Version 5.3 Table B-15 Acronym

AASF 

Interpreted Qualifiers AOI J = Estimated concentration ft 

LOD ND OSD PFAS QSM Qual μg/kg 

AOI02

1. Assistant Secretary of Defense. July 2022. Risk Based Screening Levels in Groundwater and Soil using United States Environmental ProtectionAgency’s Regional Screening Level Calculator. Hazard Quotient (HQ)=0.1 . May 2022.

8/10/2021 8/10/2021 8/10/2021 8/10/2021 8/

5-6 ft 11-12 ft 11-12 ft 10-12 ft 1

AOI02-04-SB-(11-12)

AOI02-04-SB-(5-6) AOI02-04-SB-(11-12) DUP01-SB AOI02-05-SB-(10-12) AOI02-0

AOI02-04 AOI02-04 AOI02-04 AOI02-05 A

Area of Interest 

Location ID

Sample Name

Parent Sample ID

Depth

Sample Date
Table 6-4

PFOA, PFOS, PFBS, PFNA, and PFHxS Detections in Deep Subsurface Soi

Site Inspection Report

Hammond AASF #1, Louisiana

Analyte OSD Screening Level1 Result Qual Result Qual Result Qual Result Qual Result Qual 

Soil, PFAS2 (μg/kg)

PFBS -- ND ND ND ND ND 

PFOA -- ND ND ND ND ND PFNA -- ND ND ND ND ND PFHxS -- ND ND ND ND ND PFOS -- ND ND ND ND ND References Chemical Abbreviations

PFBS Perfluorobutanesulfonic acid PFHxS Perfluorohexanesulfonic acid PFNA Perfluorononanoic acid 

2. PFAS by LC/MS/MS compliant with QSM Version 5.3 Table B-15 PFOS Perfluorooctanesulfonic acid 

PFOA Perfluorooctanoic acid Acronyms and Abbreviations

AASF Army Aviation Support FacilityAOI Area of Interestft FeetLOD Limit of DetectionND analyte not detected above the LOOSD Office of the Secretary of DefensPFAS per- and polyfluoralkyl substanceQSM Quality Systems ManualQual interpreted qualifierμg/kg micrograms/kilogram

AOI01-07 AOI01-08 AOI02-05

Area of Interest AOI 2

Location ID AOI01-02 AOI02-06 

AOI 1

1. The industrial/commercial worker screening levels are valid between 2-15 ft, nocomparison is made beyond 15 ft.

Sample Name

Parent Sample ID

AOI01-02-SB-(16-17) AOI01-07-SB-26-27 AOI01-08-SB-22-23 AOI02-05-SB-(18-20) AOI02-05-SB-(20-2

20-22 ft 

Sample Date 8/10/2021 8/11/2021 

26-27 ft 22-23 ft 18-20 ft

4/19/2022 4/20/2022 8/10/2021

Depth 16-17 ft
Site Inspection Report 

Hammond AASF #1, Louisiana Version: FINAL

EA Engineering, Science, and Technology, Inc., PBC 6-10

This page intentionally left blank 
Table 6-5 

PFAS Detections in Groundwater

Site Inspection Report

Hammond AASF #1, Louisiana

Analyte OSD Screening Level1 Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Resu

Groundwater, PFAS2 (ng/L)

PFOA 6 31 ND ND 17 ND ND 1.1 J 1.1 J ND 

PFNA 6 ND ND ND 3.6 ND ND ND ND ND 

PFBS 601 ND ND ND ND ND ND 0.48 J ND ND 

PFHxS 39 ND ND ND ND ND ND 0.81 J 0.79 J ND 

PFOS 4 ND ND ND 2.1 J 0.85 J ND 0.94 J 1.4 J ND 

Notes 

Grey Fill Detected concentration exceeded OSD Screening Levels References 

2. PFAS by LC/MS/MS compliant with QSM Version 5.3 Table B-15 

Interpreted Qualifiers 

J = Estimated concentration 

8/13/2021 

AOI 2

DUP01-GW 

Location ID

Sample Name

Parent Sample ID

AOI02-04

AOI02-04-GW

AOI02-05

AOI02-05-GW

AOI02-05-GW

8/12/2021 4/26/2022

Area of Interest

Sample Date

AOI01-01

AOI01-01-GW

8/13/2021

1. Assistant Secretary of Defense. July 2022. Risk Based Screening Levels in Groundwater and Soil using United States Environmental Protection Agency’s Regional Screening Level Calculator. Hazard Quotient (HQ)=0.1 . May 

2022.

A

AOI

8/

AOI01-07-GW

4/20/2022

AOI01-08

AOI01-08-GW

4/20/2022

AOI01-07 AOI02-05

8/12/2021 8/13/2021

AASF-01 AASF-02

AASF-01-GW AASF-02-GW

AOI 1
Site Inspection Report 

Hammond AASF #1, Louisiana Version: FINAL

EA Engineering, Science, and Technology, Inc., PBC 6-12

This page intentionally left blank 
Data Sources: 

ESRI 2020

AECOM 2020

Date:.................November 2022

Prepared By:........................WSP

Prepared For:....................USACE

Army National Guard Site Inspections

Site Inspection Report

Army Aviation Support Facility #1

Hammond, Louisiana

Figure 6-1

PFOS Detections in Soil (AOI 1 and AOI 2)

) LA

3

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

Flight Line - Apron

Former AASF 

Clam Shell 

Hangars

Main Hangar

Drainage Pond

AOI 2

AOI 1

Concrete Pond

Concrete Pond

AOI02-09

AOI02-10

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-03

AOI02-06

AASF-01

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

Flight Line - Apron

Former AASF 

Clam Shell 

Hangars

Main Hangar

Drainage Pond

AOI 2

AOI 1

Concrete Pond

Concrete Pond

AOI02-09

AOI02-10

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-06

AASF-01

!(

!(

!(

!( !(

!(

!(

!(

!(

Flight Line - Apron

Former AASF 

Clam Shell 

Hangars

Main Hangar

Drainage Pond

AOI 2

AOI 1

Concrete Pond

Concrete Pond

AOI02-09

AOI02-10

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-06

0 600

Feet

0 600

Feet

0 600

Feet

Shallow Intermediate Deep 3

Inferred Shallow Groundwater Flow

Direction (based on Preliminary

Assessment)

Hydrology/Hydrogeology

Inferred Shallow Groundwater Flow

Direction (based on August 2021 Site

Inspection Event)

Inferred Shallow Groundwater Flow

Direction (based on April 2022 Site

Inspection Event) Surface Water Flow Direction

River/Stream

Water Body

Facility Data

Area of Interest (AOI)

Facility Boundary 

Potential PFAS Release Site 
Site Inspection Report 

Hammond AASF #1, Louisiana Version: FINAL

EA Engineering, Science, and Technology, Inc., PBC 6-14

This page intentionally left blank
Da ta Sou rce s: 

ESRI 2020

AECOM 2020

Da te :.............Nove m be r 2022

Pre pa re d By:...................W SP

Pre pa re d For:...............USACE

Army National Guard Site Inspections

Site Inspection Report

Army Aviation Support Facility #1

Hammond, Louisiana

Figure 6-2

PFOA Detections in Soil (AOI 1 and AOI 2)

) LA

3

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

Former AASF

Clam Shell

Hangars

Flight Line

- Apron

Main Hangar

Concrete Pond

AOI 1

Concrete Pond

AOI02-03

AOI 2

AOI02-09

AOI02-10

AASF-01

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-06

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

Concrete Pond

AOI 1

Concrete Pond

Former AASF

Clam Shell

Hangars

Flight Line

- Apron

Main Hangar AOI 2

AOI02-09

AOI02-10

AASF-01

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-06

!(

!(

!(

!( !(

!(

!(

!(

!(

Former AASF

Clam Shell

Hangars

Flight Line

- Apron

AOI 2 Main Hangar

Concrete Pond

AOI 1

Concrete Pond

AOI02-09

AOI02-10

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-06

Inte rm e d ia te De e p

0 600

Fe e t

0 600

Fe e t

0 600

Fe e t

3

Drainage Pond Drainage Pond Drainage Pond

NOTES:

PFOA = pe rflu oroocta noic a cid

ND = Non-De te ct

(μ g /Kg ) = M icrog ra m (s) pe r Kilog ra m

Exce e d a nce s of the OSD SL a re d e picte d

w ith a ye llow ha lo.

PFOA Results (μg/kg)

!( ND (Non-De te ct)

!( >ND - 19

!!( >19 - 250

!!( >250 - 2,500

!!( >2,500

Hydrology/Hydrogeology

Infe rre d Sha llow Grou nd w a te r Flow

Dire ction (ba se d on Au g u st 2021 Site

Inspe ction Eve nt)

Infe rre d Sha llow Grou nd w a te r Flow

Dire ction (ba se d on April 2022 Site

Inspe ction Eve nt)

Su rfa ce W a te r Flow Dire ction

Rive r/Stre a m

W a te r Bod y

Facility Data

Are a of Inte re st (AOI)

Fa cility Bou nd a ry 

Pote ntia l PFAS Re le a se Site 
Site Inspection Report 

Hammond AASF #1, Louisiana Version: FINAL

EA Engineering, Science, and Technology, Inc., PBC 6-16

This page intentionally left blank 
!(

!(

!(

!( !(

!(

!(

!(

!(

AOI02-09

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-06

AOI02-10

AOI 2

Concrete Pond

AOI 1

Concrete Pond

Drainage Pond

Former AASF

Clam Shell

Hangars

Flight Line

- Apron

Main Hangar

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

AOI02-09

AASF-01

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-06

AOI02-10

AOI 2

Concrete Pond

AOI 1

Concrete Pond

Drainage Pond

Former AASF

Clam Shell

Hangars

Flight Line

- Apron

Main Hangar

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

AOI02-09

AASF-01

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-03

AOI02-06

AOI02-10

AOI 2

Concrete Pond

AOI 1

Concrete Pond

Drainage Pond

Former AASF

Clam Shell

Hangars

Flight Line

- Apron

Main Hangar

Da ta Sou rce s: 

ESRI 2020

AECOM 2020

Da te :.......................Octobe r 2022

Pre pa re d By:.......................W SP

Pre pa re d For:....................USACE

Army National Guard Site Inspections

Site Inspection Report

Army Aviation Support Facility #1

Hammond, Louisiana

Figure 6-3

PFBS Detections in Soil (AOI 1 and AOI 2)

) LA

3 Inte rm e d ia te De e p

0 600

Fe e t

0 600

Fe e t

0 600

Fe e t

NOTES:

PFBS = pe rflu orobu ta ne su lfonic a cid

ND = Non-De te ct

(μg /Kg ) = M icrog ra m (s) pe r Kilog ra m

Exce e d a nce s of the OSD SL a re d e picte d

w ith a ye llow ha lo.

PFBS Results (μg/kg)

!( ND (Non-De te ct)

!( >ND - 10

!( >10 - 1,900

!!( >1,900 - 25,000

!!( >25,000

Hydrology/Hydrogeology

Infe rre d Sha llow Grou nd w a te r Flow

Dire ction (ba se d on Au g u st 2021 Site

Inspe ction Eve nt)

Infe rre d Sha llow Grou nd w a te r Flow

Dire ction (ba se d on April 2022 Site

Inspe ction Eve nt)

Su rfa ce W a te r Flow Dire ction

Rive r/Stre a m

W a te r Bod y

Facility Data

Are a of Inte re st (AOI)

Fa cility Bou nd a ry 

Pote ntia l PFAS Re le a se Site 
Site Inspection Report 

Hammond AASF #1, Louisiana Version: FINAL

EA Engineering, Science, and Technology, Inc., PBC 6-18

This page intentionally left blank
Data Sourc e s: 

ESRI 2020

AECOM 2020

Date :..............Nove m be r 2022

Pre pare d By:................W SP

Pre pare d For:............U SACE

Army National Guard Site Inspections

Site Inspection Report

Army Aviation Support Facility #1

Hammond, Louisiana

Figure 6-4

PFHxS Detections in Soil (AOI 1 and AOI 2)

) L A

3

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

Former AASF

Clam Shell

Hangars

Flight Line

- Apron

Main Hangar

Concrete Pond

AOI 1

Concrete Pond

AOI02-03

AASF-01

AOI 2

AOI02-09

AOI02-10

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-06

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

Concrete Pond

AOI 1

Concrete Pond

Former AASF

Clam Shell

Hangars

Flight Line

- Apron

Main Hangar

AASF-01

AOI 2

AOI02-09

AOI02-10

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-06

!(

!(

!(

!( !(

!(

!(

!(

!(

Former AASF

Clam Shell

Hangars

Flight Line

- Apron

AOI 2 Main Hangar

Concrete Pond

AOI 1

Concrete Pond

AOI02-09

AOI02-10

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-06

Shallow Inte rm e d iate De e p

0 600

Fe e t

0 600

Fe e t

0 600

Fe e t

3

Drainage Pond Drainage Pond Drainage Pond

Hydrology/Hydrogeology

Infe rre d Shallow Ground wate r Flow

Dire c tion (base d on August 2021 Site

Inspe c tion Eve nt)

Infe rre d Shallow Ground wate r Flow

Dire c tion (base d on April 2022 Site

Inspe c tion Eve nt)

Surfac e W ate r Flow Dire c tion

Rive r/Stre am

W ate r Bod y

Facility Data

Are a of Inte re st (AOI)

Fac ility Bound ary 

Pote ntial PFAS Re le ase Site 

NOTES:

PFHxS = pe rfluorohe xane sulfonic ac id

ND = Non-De te c t

(μg /Kg ) = Mic rogram (s) pe r Kilogram

Exc e e d anc e s of the OSD SL are d e pic te d

w ith a ye llow halo.

PFHxS Results (μg/kg)

!( ND (Non-De te c t)

!( >ND - 13

!( >13 -130

!!( >130 - 1,600

!!(>1,600
Site Inspection Report 

Hammond AASF #1, Louisiana Version: FINAL

EA Engineering, Science, and Technology, Inc., PBC 6-20

This page intentionally left blank
Da ta Sou rce s: 

ESRI 2020

AECOM 2020

Da te :.................Nove m be r 2022

Pre pa re d By:.......................W SP

Pre pa re d For:.................USACE

Army National Guard Site Inspections

Site Inspection Report

Army Aviation Support Facility #1

Hammond, Louisiana

Figure 6-5

PFNA Detections in Soil (AOI 1 and AOI 2)

) LA

3

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

Former AASF

Clam Shell

Hangars

Flight Line

- Apron

Main Hangar

AASF-01

Concrete Pond

AOI 1

Concrete Pond

AOI 2

AOI02-09

AOI02-10

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-06

AOI02-03

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

Concrete Pond

AOI 1

Concrete Pond

AASF-01

Former AASF

Clam Shell

Hangars

Flight Line

- Apron

Main Hangar AOI 2

AOI02-09

AOI02-10

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-06

!(

!(

!(

!( !(

!(

!(

!(

!(

Former AASF

Clam Shell

Hangars

Flight Line

- Apron

AOI 2 Main Hangar

Concrete Pond

AOI 1

Concrete Pond

AOI02-09

AOI02-10

AOI01-07

AOI01-08

AOI01-01

AOI01-02

AOI02-04

AOI02-05

AOI02-06

Sha llow Inte rm e d ia te De e p

0 600

Fe e t

0 600

Fe e t

0 600

Fe e t

3

Drainage Pond Drainage Pond Drainage Pond

Hydrology/Hydrogeology

Infe rre d Sha llow Grou nd w a te r Flow

Dire ction (ba se d on Au g u st 2021 Site

Inspe ction Eve nt)

Infe rre d Sha llow Grou nd w a te r Flow

Dire ction (ba se d on April 2022 Site

Inspe ction Eve nt)

Su rfa ce W a te r Flow Dire ction

Rive r/Stre a m

W a te r Bod y

Facility Data

Are a of Inte re st (AOI)

Fa cility Bou nd a ry 

Pote ntia l PFAS Re le a se Site 

NOTES:

PFNA = pe rflu oronona noic a cid

ND = Non-De te ct

(μg /Kg ) = M icrog ra m (s) pe r Kilog ra m

Exce e d a nce s of the OSD SL a re d e picte d

w ith a ye llow ha lo.

PFNA Results (μg/kg)

!( ND (Non-De te ct)

!( >ND - 19

!!( >19 - 250

!!( >250 - 2,500

!!( >2,500
Site Inspection Report 

Hammond AASF #1, Louisiana Version: FINAL

EA Engineering, Science, and Technology, Inc., PBC 6-22

This page intentionally left blank
0 600

Feet

Data Sources: 

ESRI 2020

AECOM 2020

Date:.........November 2022

Prepared By:..............WSP

Prepared For:.........USACE

Army National Guard Site Inspections

Site Inspection Report

Army Aviation Support Facility #1

Hammond, Louisiana

Figure 6-6

PFOA, PFOS and PFBS Detections in Groundwater (AOI 1 and AOI 2)

) LA

3

!(

!(

!(

!(

!(

!!(

!!(

!(

!(

!(

Flight Line - Apron

Former AASF 

Clam Shell 

Hangars

Main Hangar

Drainage Pond

AOI 2

AOI 1

Concrete Pond

Concrete Pond

AOI02-09

AOI02-10

AOI01-07

AOI01-08

AASF-01

AOI01-01

AOI02-04

AOI02-05 AOI02-06

AASF-02

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

Flight Line - Apron

Former AASF 

Clam Shell 

Hangars

Main Hangar

Drainage Pond

AOI 2

AOI 1

Concrete Pond

Concrete Pond

AOI02-09

AOI02-10

AASF-02

AOI01-07

AOI01-08

AASF-01

AOI01-01

AOI02-04

AOI02-05

AOI02-06

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

Flight Line - Apron

Former AASF 

Clam Shell 

Hangars

Main Hangar

Drainage Pond

AOI 2

AOI 1

Concrete Pond

Concrete Pond

AOI02-09

AOI02-10

AASF-02

AOI01-07

AOI01-08

AASF-01

AOI01-01

AOI02-04

AOI02-05 AOI02-06

0 600

Feet

0 600

Feet

0 600

Feet

3 PFOA PFOS PFBS

NOTES:

PFOS = perfluorooctanesulfonic acid

PFOA = perfluorooctanoic acid

PFBS = perfluorobutanesulfonic acid

ND = Non-Detect

ng/L = nanogram(s) per liter

Exceedances of the OSD SL are depicted with a

yellow halo.

Hydrology/Hydrogeology

Inferred Shallow Groundwater Flow

Direction (based on August 2021 Site

Inspection Event)

Inferred Shallow Groundwater Flow

Direction (based on April 2022 Site

Inspection Event)

Surface Water Flow Direction

River/Stream

Water Body

Facility Data

Area of Interest (AOI)

Facility Boundary 

Potential PFAS Release Site 

Hydrology/Hydrogeology

Inferred Shallow Groundwater Flow

Direction (based on August 2021 Site

Inspection Event)

Inferred Shallow Groundwater Flow

Direction (based on April 2022 Site

Inspection Event)

Surface Water Flow Direction

River/Stream

Water Body

Facility Data

Area of Interest (AOI)

Facility Boundary 

Potential PFAS Release Site 

PFOS Results (ng/L) PFBS (ng/L)

!( ND (Non-Detect)

!( >ND - 100

!!( >601 - 1,000

!!( >1,000

!( >100 - 601

!( ND (Non-Detect)

!( >ND - 4

!!( >4 - 40

!!( >40 - 70

!!( >70

PFOA Results (ng/L)

!( ND (Non-Detect)

!( >ND - 6

!!( >40 - 70

!!( >70

!!( >6 - 40
Site Inspection Report 

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0 600

Feet

Date:........November 2022

Prepared By:.............WSP

Prepared For:.........USACE

Army National Guard Site Inspections

Site Inspection Report

Army Aviation Support Facility #1

Hammond, Louisiana

Figure 6-7

PFHxS and PFNA Detections in Groundwater (AOI 1 and AOI 2)

) LA

3

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

Flight Line - Apron

Airfield Crash Site

Former AASF 

Clam Shell 

Hangars

Main Hangar

Drainage Pond

AOI 2

AOI 1

Concrete Pond

Concrete Pond

AOI02-09

AOI02-10

AOI01-07

AOI01-08

AASF-01

AOI01-01

AOI02-04

AOI02-05

AOI02-06

AASF-02

!(

!(

!(

!(

!(

!(

!(

!(

!(

!(

Flight Line - Apron

Airfield Crash Site

Former AASF 

Clam Shell 

Hangars

Main Hangar

Drainage Pond

AOI 2

AOI 1

Concrete Pond

Concrete Pond

AOI02-09

AOI02-10

AASF-02

AOI01-07

AOI01-08

AASF-01

AOI01-01

AOI02-04

AOI02-05

AOI02-06

0 600

Feet

0 600

Feet

3 PFHxS PFNA

Data Sources: 

ESRI 2020

AECOM 2020

Hydrology/Hydrogeology

Inferred Shallow Groundwater Flow

Direction (based on August 2021 Site

Inspection Event)

Inferred Shallow Groundwater Flow

Direction (based on April 2022 Site

Inspection Event)

Surface Water Flow Direction

River/Stream

Water Body

Facility Data

Area of Interest (AOI)

Facility Boundary 

Potential PFAS Release Site 

PFHxS Results (ng/L)

!( ND (Non-Detect)

!( >ND - 39

!!( >39 - 100

!!( >100 - 1000

!!( >1,000

PFNA Results (ng/L)

!( ND (Non-Detect)

!( >ND - 6

!!( >6 - 100

!!( >100 - 1000

!!( >1000

NOTES:

PFHxS = Perfluorohexanesulfonic acid

PFNA = Perfluorononanoic acid

ND = Non-Detect

ng/L = nanogram(s) per liter

Exceedances of the OSD SL are depicted with a yellow halo
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Site Inspection Report 

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7. EXPOSURE PATHWAYS

The conceptual site model (CSM) for each AOI, revised based on the SI findings, is presented on 

Figure 7-1 and Figure 7-2. Please note that while the CSM discussion assists in determining if a 

receptor may be impacted, the decision to move from SI to RI or interim action is determined 

based upon exceedances of the SLs for the relevant compounds and whether the release is more 

than likely attributable to the DoD. A CSM presents the current understanding of the site 

conditions with respect to known and suspected sources, potential transport mechanisms and 

migration pathways, and potentially exposed human receptors. A human exposure pathway is 

considered potentially complete when the following conditions are present: 

1. Contaminant source;

2. Environmental fate and transport;

3. Exposure point;

4. Exposure route; and

5. Potentially exposed populations.

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

circle symbol to represent an incomplete exposure pathway. Areas with no identified complete 

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

complete if the relevant compounds are detected, in which case the CSM figure uses a half-filled 

circle symbol to represent a potentially complete exposure pathway. Additionally, a completely 

filled circle symbol is used to indicate when a potentially complete exposure pathway has 

detections of the relevant compounds above the SLs. Areas with an identified potentially 

complete pathway and a complete pathway may warrant further investigation. Although the 

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

for future study in a RI or no action at this time is based on the comparison of the SI analytical 

results for the relevant compounds to the SLs.

In general, the potential routes of exposure to the relevant compounds are ingestion and 

inhalation. Human exposure via the dermal contact pathway may occur, and current risk practice 

suggests it is an insignificant pathway compared to ingestion; however, exposure data for dermal 

pathways are sparse and continue to be the subject of toxicological study. The receptors 

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

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

workers, visitors/trespassers, and off-facility residents. 

7.1 SOIL EXPOSURE PATHWAY 

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

between the source and potential receptors at each AOI based on the aforementioned criteria. 
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7.1.1 AOI 1 – C12 Hangar 

AOI 1 houses C12 aircraft maintenance operations. According to the PA report, the C12 Hangar 

was constructed between 2007 and 2009 and is charged with a Chemguard AFFF suppression 

deluge system with a 441-gallon-capacity tank. The system is manually operated by a hose inside 

the hangar, and according to the ARNG the AFFF storage tank is located in an adjacent room 

(#15) within the C12 Hangar (AECOM, 2020). The ARNG also indicated a 36-gallon fire 

suppression tank is located against a wall within the hangar. 

PFOA was detected in surface soil at AOI 1 at a concentration below the SL. Site workers, 

construction workers, and trespassers/visitors could contact constituents in soil via incidental 

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

construction workers, and trespassers/recreational users are potentially complete. PFOS, PFOA, 

PFBS, PFHxS, and PFNA were not detected in subsurface soil at AOI 1; therefore, exposure 

pathways pertaining to subsurface soil are incomplete. The CSM for AOI 1 is presented on 

Figure 7-1. 

7.1.2 AOI 2 – Main Hangar and Flight Line-Apron

AOI 2 houses helicopter maintenance operations. According to the PA report, the Main Hangar 

was constructed between 2007 and 2009 and is charged with a Buckeye 3% AFFF concentrate 

suppression deluge system fed by a 999-gallon tank (AECOM, 2020). 

PFOS, PFOA, PFBS, PFHxS, and PFNA were not detected in soil at AOI 2. Therefore, the soil 

exposure pathways for incidental ingestion and inhalation of dust by site workers, construction 

workers, and trespasser/recreational users pertaining to AOI 2 soil are incomplete. The CSM for 

AOI 2 is presented in Figure 7-2. 

7.2 GROUNDWATER EXPOSURE PATHWAY

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

exists between the source and potential receptors at each AOI based on the aforementioned 

criteria. 

7.2.1 AOI 1 – C2 Hangar 

Samples of groundwater were collected from temporary monitoring wells in AOI 1. PFOA was 

detected above its SL in two groundwater samples collected at AOI 1, while PFOS and PFNA

were detected below their respective SLs. PFBS and PFHxS were not detected in the 

groundwater samples. Depths to water measured at AOI 1 during the SI ranged from 

approximately 2 to 29 feet bgs; therefore, the exposure pathway for ingestion of groundwater is 

potentially complete for construction workers involved in ground disturbing activities that extend 

to the water table. No potable wells are located within the Facility boundary. The Facility 

receives potable water from a municipal source. Three industrial use wells are located within the 

Facility. Therefore, potential exposure to site workers to constituents in groundwater is limited to 

incidental ingestions through non-potable (industrial) use on the Facility. It is unlikely 

trespassers/recreational users would ingest the non-potable (industrial) water, and therefore the 
Site Inspection Report 

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exposure pathway for these receptors is incomplete. Due to the presence of public water system 

wells and domestic supply wells within a 4-mile radius of the Facility, the exposure pathway for 

groundwater to off-facility residents via ingestion of groundwater is considered potentially 

complete. The CSM for AOI 1 is presented on Figure 7-1. 

7.2.2 AOI 2 – Main Hangar and Flight Line-Apron

Samples of groundwater were collected from temporary monitoring wells in AOI 2. PFOA, 

PFOS, PFBS, and PFHxS were detected at concentrations below their respective SLs in 

groundwater at AOI 2, while PFNA was not detected. Depths to water measured at AOI 2 during 

the SI ranged from approximately 2 to 8 feet bgs; therefore, the exposure pathway for ingestion 

of groundwater is potentially complete for construction workers involved in ground disturbing 

activities that extend to the water table. No potable wells are located within the Facility 

boundary. The Facility receives potable water from a municipal source. Three industrial use 

wells are located within the Facility. Therefore, potential exposure to site workers to constituents 

in groundwater is limited to incidental ingestions through non-potable (industrial) use on the 

Facility. It is unlikely trespassers/recreational users would ingest the non-potable (industrial) 

water, and therefore the exposure pathway for these receptors is incomplete. Due to the presence 

of public water system wells and domestic supply wells within a 4-mile radius of the Facility, the 

exposure pathway for groundwater to off-facility residents via ingestion of groundwater is 

considered potentially complete. The CSM for AOI 2 is presented in Figure 7-2. 

7.3 SURFACE WATER AND SEDIMENT EXPOSURE PATHWAY

A retention basin that is located near the southeast corner of the Facility receives stormwater 

flow from the areas of AOI 1 and AOI 2. The basin has no outlet and is not known to overflow. 

SI results in soil and groundwater from AOI 1 and AOI 2, 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. 

PFAS are water soluble and can migrate readily from soil to surface water via leaching and runoff. Because PFOA was detected in soil and groundwater at AOI 1 and PFOA, PFOS, PFHxS, 

PFNA, and PFBS were detected in groundwater at AOI 2, it is possible that those compounds 

may have migrated from soil and/or groundwater to the retention basin in the southeast corner of 

the Facility via groundwater discharge or overland flow. Therefore, the surface water and 

sediment ingestion exposure pathway for site workers, construction workers, or trespassers is 

considered potentially complete. 
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SOURCE

Source Release 

Mechanism Media

RECEPTOR

Human 

Activities

Leaching/ 

Infiltration

Airborne Soil 

Particulate

Surface Soil 

Surface

Water/

Sediment

Subsurface 

Soil

PATHWAY

Transport 

and Migration Media Exposure Routes

Inhalation of 

Dust

Human Receptors: 

Current/ Future

Site 

Worker

Construction 

Worker

Resident1

Site 

Worker

Construction

Worker

Resident1

/ /

/ / /

/ /

Figure 7-1

Conceptual Site Model, AOI 1

Hammond AASF #1

/

/ /

/ /

/

/

/ /

/

/

/

AOI 1 – C12 

Hangar Precipitation/ 

Run-Off

/

/

Ingestion

/

Trespasser/

Recreational User1

Trespasser/

Recreational User1

/

Ingestion

Ingestion

Ingestion

/

NOTES

1. The resident and recreational users refer 

to off-site receptors.

/ / /

Surface 

Water 

Flow

Surface 

Soil

Subsurface 

Soil

Potential spills, 

leaks, or 

discharges from 

AFFF deluge 

suppression 

systems

Surface 

Water

Shallow 

Groundwater

Potential 

Off-Facility 

Sources Not 

Under 

Control of 

ARNG
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SOURCE

Source Release 

Mechanism Media

RECEPTOR

Human 

Activities

Leaching/ 

Infiltration

Airborne Soil 

Particulate

Surface Soil 

Surface

Water/

Sediment

Subsurface 

Soil

PATHWAY

Transport 

and Migration Media Exposure Routes

Inhalation of 

Dust

Human Receptors: 

Current/ Future

Site 

Worker

Construction 

Worker

Resident1

Site 

Worker

Construction

Worker

Resident1

/ /

/ / /

/ /

Figure 7-2

Conceptual Site Model, AOI 2

Hammond AASF #1

/

/ /

/ /

/

/

/ /

/

/

/

AOI 2 –

Main Hangar 

and Flight 

Line-Apron Precipitation/ 

Run-Off

/

Ingestion

Trespasser/

Recreational User1

Trespasser/

Recreational User1

Ingestion

Ingestion

Ingestion

/

NOTES

1. The resident and recreational users refer 

to off-site receptors.

/ / /

Surface 

Water 

Flow

Surface 

Soil

Subsurface 

Soil

Potential spills, 

leaks, or 

discharges from 

AFFF deluge 

suppression 

systems

Surface 

Water

Shallow 

Groundwater

Potential 

Off-Facility 

Sources Not 

Under 

Control of 

ARNG / / /
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8. SUMMARY AND OUTCOME

This section summarizes the 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 at the Facility were conducted from 9 through 13 August 2021, and from 

19 through 22 and on 26 April 2022. The SI field activities included soil and groundwater 

sampling. Field activities were conducted in accordance with the UFP-QAPP Addendum 

(EA/Wood, 2021) and Supplemental UFP-QAPP Addendum (EA/Wood, 2022), except as 

previously noted in Section 5.8. 

To fulfill the project DQOs set forth in the approved UFP-QAPP Addendum (EA/Wood, 2021), 

samples were collected and analyzed for a subset of 18 compounds by LC/MS/MS compliant 

with QSM 5.3 Table B-15 (DoD, 2020) as follows. 

• Thirty (30) soil samples from eleven (11) locations (soil borings);

• Ten (10) grab groundwater samples from temporary well locations; and

• Twenty-three (23) QA/QC samples.

An SI is conducted when the PA determines an AOI exists based on probable use, storage, and/or 

disposal of PFAS-containing materials. The SI includes multi-media sampling at AOIs to 

determine whether or not a release has occurred. The SI may conclude further investigation is 

warranted, a removal action is required to address immediate threats, or no further action is 

required. Additionally, the CSMs were refined to assess whether a potentially complete pathway 

exists between the source and potential receptors at the AOIs, as described in Section 7. 

8.2 OUTCOME

Based on the results of this SI, further evaluation in the form of an RI is warranted for AOI 1. 

Further evaluation is not warranted at AOI 2 (see Table 8-1). Based on the CSMs developed and 

revised based on the SI findings, there is potential for exposure to receptors from AOI 1 and AOI 

2 from Facility sources resulting from historical DoD activities. There is potential that an off-site

upgradient source has impacted groundwater migrating onto the Facility; although the synoptic 

groundwater elevations indicate variable flow direction between sampling events. 

Sample analytical concentrations collected during the SI were compared against the project SLs 

in soil and groundwater, as described in Table 6-1. The SI results relative to the SLs are 

summarized below for each AOI. 
Site Inspection Report 

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At AOI 1:

• PFOA was detected in surface soil at a concentration below the SL. PFOS, PFBS,

PFHxS, and PFNA were not detected in soil at AOI 1.

PFOA was detected above its SL in two groundwater samples collected at AOI 1; PFOS and 

PFNA were detected in one groundwater sample at concentrations below their respective SLs; 

and PFBS and PFHxS were not detected.

At AOI 2:

• PFOS, PFOA, PFBS, PFHxS, and PFNA were not detected in soil at AOI 2.

PFOS, PFOA, PFBS, and PFHxS were detected at concentrations below their respective SLs in 

groundwater at AOI 2, while PFNA was not detected. 

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

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

screening values were established after SI planning and execution. However, ARNG will add 

HFPO-DA to the list of constituents sampled during the next phase of CERCLA if warranted.

Table 8.1 summarizes the SI results for soil and groundwater used to determine if an AOI should 

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

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

Hammond AASF #1, Louisiana

Site Inspection Report

AOI Potential Release 

Area

Soil –

Source Area

Groundwater –

Source Area

Groundwater – 

Facility Boundary Future Action

1 C12 Hangar Proceed to RI

2 Main Hangar and 

Flight Line-Apron NFA

Legend:

= detected; exceedance of screening levels.

= detected; no exceedance of screening levels.

= not detected.

Abbreviations:

AOI = area of interest

NFA = no further action

RI = remedial investigation
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9. REFERENCES

AECOM Technical Services, Inc. (AECOM). 2020. Final Preliminary Assessment Report, Army 

Aviation Support Facility #1, Hammond Louisiana. July. 

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

the Department of Defense Cleanup Program. United States Department of Defense. 6 

July. 

Department of the Army (DA). 2016a. EM-200-1-2, Environmental Quality, Technical Project 

Planning Process. Department of Army Guidance to Address Perfluorooctane Sulfonate 

(PFOS) and Perfluorooctanoic Acid (PFOA) Contamination. Memorandum DAIM-IS. 

August. 

Department of Defense and Department of Energy (DoD/DOE 2019a). Department of Defense 

(DoD) Department of Energy (DOE) Consolidated Quality Systems Manual (QSM) for 

Environmental Laboratories. Version 5.3. May.

DoD. 2019b. General Data Validation Guidelines. November. 

DoD. 2020. Data Validation Guidelines Module 3: Data Validation Procedure for Per- and 

Polyfluoroalkyl Substances Analysis by QSM Table B-15. May. 

EA, Engineering, Science, and Technology, PBC (EA). 2014. Direct-Push Technology 

Sampling. Standard Operating Procedure 047. 

EA. 2020. Final Programmatic Uniform Federal Policy Quality Assurance Project Plan, Site 

Inspections for Per- and Polyfluoroalkyl Substances Impacted Sites, ARNG Installations, 

Nationwide. December.

EA. 2021. Accident Prevention Plan, Programmatic Uniform Federal Policy Quality Assurance 

Project Plan, Site Inspections for Per- and Polyfluoroalkyl Substances Impacted Sites, 

ARNG Installations, Nationwide, Revision 1. November. 

EA, Engineering, Science, and Technology, PBC and Wood Environment & Infrastructure 

Solutions, Inc. (EA/Wood). 2021a. Final Site Inspection Uniform Federal Policy Quality 

Assurance Project Plan (UFP-QAPP) Addendum, Army Aviation Support Facility #1, 

Hammond, Louisiana, Per- and Polyfluoroalkyl Substances Impacted Sites, ARNG 

Installations, Nationwide. November. 

EA/Wood 2021b. Final Accident Prevention Plan/Site Safety and Health Plan, Hammond Army 

Aviation Support Facility #1, Louisiana, Site Inspections for Per- and Polyfluoroalkyl 

Substances Impacted Sites, ARNG Installations, Nationwide, Revision 1. April.

EA/Wood. 2022. Final Supplemental Site Inspection Addendum to Uniform Federal Policy 

Quality Assurance Project Plan (UFP-QAPP), Army Aviation Support Facility #1, 
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Hammond AASF #1, Louisiana Version: FINAL

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Hammond, Louisiana, Per- and Polyfluoroalkyl Substances Impacted Sites, ARNG 

Installations, Nationwide. April. 

Guelfo, J.L. and C.P. Higgins. 2013. Subsurface transport potential of perfluoroalkyl acids and 

aqueous film-forming foam (AFFF)-impacted sites. Environmental Science and 

Technology 47(9):4164-71. 

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

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

Interstate Technology Regulatory Council (ITRC). 2018. Environmental Fate and Transport for 

Per- and Polyfluoroalkyl Substances. March. 

U.S. Environmental Protection Agency (USEPA). 1980. Comprehensive Environmental

Response, Compensation, and Liability Act (CERCLA). 11 December.

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

Rule). 40 Code of Federal Regulations Part 300; 59 Federal Register 47384. September. 

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

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

Assessments). December.

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

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

Innovation. January.

USEPA. 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. 

U.S. Fish and Wildlife Service (USFWS). 2021. Endangered Species. Available at: 

http://ecos.fws.gov/ipac/. Accessed 30 August. 

Xiao, F., M.F. Simcik, T.R. Halbach, and J.S Gulliver. 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.