FINAL

Site Inspection Report

Facility Maintenance Shop #7

Norfolk, Nebraska

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

Perfluorohexanesulfonic Acid (PFHxS), Perfluorononanoic acid (PFNA), Hexafluoropropylene 

oxide dimer acid (HFPO-DA), and Perfluorobutanesulfonic Acid (PFBS) 

ARNG Installations, Nationwide

October 2023

Prepared for

Army National Guard Headquarters 

111 S. George Mason Drive 

Arlington, VA 22204

UNCLASSIFIED
Site Inspection Report

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TABLE OF CONTENTS

Page

LIST OF APPENDICES ................................................................................................................ iv

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 .............................................................................. 2-2

2.1 FACILITY LOCATION AND DESCRIPTION ..................................... 2-2

2.2 FACILITY ENVIRONMENTAL SETTING .......................................... 2-2

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

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

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

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

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

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

2.3 HISTORY OF PFAS USE ....................................................................... 2-4

3. SUMMARY OF AREAS OF INTEREST ........................................................... 3-2

3.1 AOI 1 – FIRETRUCK STORAGE BUILDING ..................................... 3-2

4. PROJECT DATA QUALITY OBJECTIVES ..................................................... 4-1

4.1 PROBLEM STATEMENT ...................................................................... 4-1

4.2 INFORMATION INPUTS ....................................................................... 4-1

4.3 STUDY BOUNDARIES ......................................................................... 4-1

4.4 ANALYTICAL APPROACH ................................................................. 4-1

4.5 DATA USABILITY ASSESSMENT ...................................................... 4-2

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

5.1 PRE-INVESTIGATION ACTIVITIES ................................................... 5-1

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 .. 5-2
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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 ............................... 5-4

5.5 SURVEYING .......................................................................................... 5-5

5.6 INVESTIGATION-DERIVED WASTE ................................................. 5-5

5.7 LABORATORY ANALYTICAL METHODS ....................................... 5-5

5.8 DEVIATIONS FROM UFP-QAPP ADDENDUM ................................. 5-5

6. SITE INSPECTION RESULTS .......................................................................... 6-2

6.1 SCREENING LEVELS ........................................................................... 6-2

6.2 SOIL PHYSICOCHEMICAL ANALYSES ............................................ 6-3

6.3 AOI 1 ....................................................................................................... 6-3

6.3.1 AOI 1 – Soil Analytical Results................................................ 6-3

6.3.2 AOI 1 – Groundwater Analytical Results ................................. 6-4

6.3.3 AOI 1 – Conclusions ................................................................. 6-4

6.4 BOUNDARY SAMPLE LOCATIONS .................................................. 6-4

6.4.1 Boundary Locations – Soil Analytical Results ......................... 6-4

6.4.2 Boundary Locations – Groundwater Analytical Results .......... 6-4

6.4.3 Conclusions ............................................................................... 6-5

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

7.1 SOIL EXPOSURE PATHWAY .............................................................. 7-1

7.1.1 AOI 1 ........................................................................................ 7-2

7.2 GROUNDWATER EXPOSURE PATHWAY........................................ 7-2

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

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

8.1 SITE INSPECTION ACTIVITIES .......................................................... 8-1

8.2 OUTCOME .............................................................................................. 8-1

9. REFERENCES .................................................................................................... 9-1
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LIST OF APPENDICES

Appendix A. Data Usability Assessment and Data Validation Reports

Appendix B. Field Documentation

B1. Log of Daily Notice of Field Activities

B2. Field Forms 

B3. Survey Data 

B4. Field Change Request Form 

Appendix C. Technical Project Planning Meeting Minutes

Appendix D. Boring Logs and Well Construction Diagrams 

Appendix E. Analytical Results

Appendix F. Laboratory Reports

LIST OF FIGURES

Figure 2-1. Facility Location

Figure 2-2. Topography 

Figure 2-3. Groundwater Features 

Figure 2-4. Surface Water Features

Figure 2-5. Groundwater Elevations, December 2021 

Figure 3-1. Areas of Interest

Figure 5-1. Site Inspection Sample Locations

Figure 6-1. PFOS Detections in Soil

Figure 6-2. PFOA Detections in Soil

Figure 6-3. PFBS Detections in Soil

Figure 6-4. PFHxS Detections in Soil

Figure 6-5. PFNA Detections in Soil

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

Figure 6-7. PFHxS and PFNA Detections in Groundwater 

Figure 7-1. Conceptual Site Model, AOI 1 
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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, Norfolk FMS #7, Norfolk, Nebraska, Site Inspection 

Report 

Table 5-2. Soil Boring Depths and Temporary Well Screen Intervals, Norfolk FMS #7, 

Norfolk, Nebraska, Site Inspection Report

Table 5-3. Groundwater Elevations, Norfolk FMS #7, Norfolk, Nebraska, 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, Norfolk FMS #7 

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

Site Inspection Report, Norfolk FMS #7 

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

Inspection Report, Norfolk FMS #7 

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

Inspection Report, Norfolk FMS #7 

Table 8-1. Summary of Site Inspection Findings and Recommendations 
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LIST OF ACRONYMS AND ABBREVIATIONS

°C Degrees Celsius

°F Degrees Fahrenheit

% Percent

μg/kg Microgram(s) per kilogram

AECOM AECOM Technical Services, Inc. 

AFFF Aqueous film-forming foam 

amsl Above mean sea level

AOI Area of Interest

ARNG Army National Guard

ASTM American Society for Testing and Materials

bgs Below ground surface 

btoc Below top of casing 

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act 

COC Chain-of-custody 

CSM Conceptual site model

DA U.S. Department of the Army

DoD Department of Defense

DPT Direct-push technology

DQO Data quality objective 

DUA Data usability assessment

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

ELAP Environmental Laboratory Accreditation Program

EM Engineer Manual 

FB Field blank 

FMS Facility Maintenance Shop

ft Foot (feet)

HA Health Advisory 

HDPE High-density polyethylene 

HFPO-DA Hexafluoropropylene oxide dimer acid 

ID Identification

IDW Investigation-derived waste

ITRC Interstate Technology Regulatory Council 

Koc Organic carbon normalized distribution coefficient

LC/MS/MS Liquid Chromatography/Tandem Mass Spectrometry
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LIST OF ACRONYMS AND ABBREVIATIONS (continued)

MIL SPEC Military specification

MS Matrix spike

MSD Matrix spike duplicate

NEARNG Nebraska Army National Guard 

NELAP National Environmental Laboratory Accreditation Program

ng/g Nanogram(s) per gram 

ng/L Nanogram(s) per liter

No. Number 

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 

PID Photoionization detector 

PVC Polyvinyl chloride

QA Quality Assurance 

QAPP Quality Assurance Project Plan

QC Quality control 

QSM Quality Systems Manual 

RI Remedial Investigation 

SI Site Inspection

SL Screening level

TOC Total organic carbon 

TPP Technical Project Planning 

UFP Uniform Federal Policy 

USACE U.S. Army Corps of Engineers 

USEPA U.S. Environmental Protection Agency
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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 from the Office of the Secretary of Defense (OSD) (Assistant Secretary of 

Defense) dated 6 July 2022. The six compounds listed in the OSD memorandum include 

perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorobutanesulfonic 

acid (PFBS), perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), and 

hexafluoropropylene oxide-dimer acid (HFPO-DA) 1. These compounds are collectively referred 

to as “relevant compounds” throughout the document and the applicable screening levels (SLs) 

are provided below in Table ES-1.

The PA identified one Area of Interest (AOI) 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 AOI 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 Norfolk Facility Maintenance Shop (FMS) #7 located in Norfolk, Nebraska and 

it was determined that no further evaluation under the Comprehensive Environmental Response, 

Compensation, and Liability Act (CERCLA) is warranted for the AOI 1 at this time. The Norfolk 

FMS #7 will be referred to as the “Facility” throughout this document. 

The Facility, operated by the Nebraska ARNG (NEARNG), encompasses approximately 

13.6 acres in Madison County, Nebraska, approximately 1 mile south of Norfolk, Nebraska. The 

Facility provides support through fleet maintenance on various vehicles including trucks, fire 

trucks, jeeps, and heavy equipment for several NEARNG units. The property has been owned 

and operated by the State of Nebraska since 2003 and was previously owned by the City of 

Norfolk. The Norfolk FMS #7 is located within the Elkhorn River Valley, approximately 

2,300 feet southwest of the Elkhorn River (AECOM Technical Services, Inc. [AECOM] 2020).

The PA identified one AOI for investigation during the SI phase. SI sampling results from the 

AOI were compared to OSD SLs for the relevant compounds. Table ES-2 summarizes the SI 

results for the AOI. Based on the results of this SI, no further evaluation under CERCLA is 

warranted at this time.

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

GenX) was not included as an analyte at the time of this SI. Based on the conceptual site model (CSM) developed 

during the PA and revised based on SI findings, the presence of HFPO-DA is not anticipated at the facility because 

HFPO-DA is generally not a component of military specification (MIL-SPEC) aqueous film forming foam (AFFF) 

and based on its history including distribution limitations that restricted use of GenX, it is generally not a component 

of other products the military used. In addition, it is unlikely that GenX would be an individual chemical of concern 

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

Analyte

Residential

(Soil)

(μg/kg)

1

0-2 ft bgs

Industrial/Commercial

Composite Worker

(Soil)

(μg/kg) 1

2-15 ft bgs

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. 2022. Risk Based Screening Levels Calculated for Groundwater 

and Soil using U.S. Environmental Protection Agency’s Regional SL Calculator. Hazard Quotient 

(HQ) = 0.1. July 2022.

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

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

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

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

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

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

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

bgs = Below ground surface

μg/kg = Microgram(s) per kilogram

ng/L = Nanogram(s) per liter

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 Firetruck Storage Building

No Further Action

Legend:

 = Detected; exceedance of screening levels.

 = Detected; no exceedance of screening levels.

 = Not detected.
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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 six 

compounds presented in the memorandum from the Office of the Secretary of Defense (OSD) 

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

memorandum will be referred to as “relevant compounds” throughout this document and include 

perfluorooctanesulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorobutanesulfonic 

acid (PFBS), perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), and 

hexafluoropropylene oxide-dimer acid (HFPO-DA)2 at ARNG facilities nationwide. The ARNG 

performed this SI at the Norfolk Facility Maintenance Shop (FMS) #7 located in Norfolk, 

Nebraska. The Norfolk FMS#7 will be referred to as the “Facility” throughout this document.

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 the Army (DA) requirements and guidance for field investigations.

1.2 SITE INSPECTION PURPOSE

A PA was performed at the Norfolk FMS #7 (AECOM Technical Services, Inc. [AECOM] 2020) 

that identified one Area of Interest (AOI) 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 AOI 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.

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

GenX) was not included as an analyte at the time of this SI. Based on the conceptual site model (CSM) developed 

during the PA and revised based on SI findings, the presence of HFPO-DA is not anticipated at the facility because 

HFPO-DA is generally not a component of military specification (MIL-SPEC) aqueous film forming foam (AFFF) 

and based on its history including distribution limitations that restricted use of GenX, it is generally not a component 

of other products the military used. In addition, it is unlikely that GenX would be an individual chemical of concern 

in the absence of other PFAS.
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2. FACILITY BACKGROUND

2.1 FACILITY LOCATION AND DESCRIPTION

Norfolk FMS #7 is located in Madison County, Nebraska, approximately 1 mile south of 

Norfolk, Nebraska. The facility is adjacent to the Norfolk Regional Airport (Figure 2-1). 

Norfolk FMS#7 is accessible from North Airport Road. Norfolk FMS #7 provides maintenance 

support for several Nebraska ARNG (NEARNG) units by performing fleet maintenance on 

various vehicles including trucks, fire trucks, jeeps, and heavy equipment. The Facility contains 

five work bays that accommodate five vehicles, allowing 30 to 50 vehicles to undergo 

maintenance at any time. The Norfolk FMS #7 was constructed on a parcel of land that is 

approximately 13.6 acres and has been owned and operated by the State of Nebraska since 2003. 

Before 2003, the City of Norfolk owned and operated the land. The Norfolk FMS #7 building 

was built between May 2003 and December 2004. The facility consists of the Administration and 

Maintenance Hangar, oil/water separator system, an unheated storage building, and parking lots 

(AECOM 2020).

2.2 FACILITY ENVIRONMENTAL SETTING

Norfolk FMS #7 is in the Elkhorn River Valley. The facility is approximately 2,300 feet (ft)

south of the Elkhorn River with farmland to the east and west. There are five lakes located within 

3 miles of the facility. Mendelmans Lake, Andys Lake, Pofahl Lake, and Lehman Lake are

located to the east of the facility, and Saras Lake is located to the north. The elevation of the 

facility is approximately 1,573 ft above mean sea level (amsl) (AECOM 2020).

The following sections include information on geology, hydrogeology, hydrology, climate, and 

current and future land use. The topography at Norfolk FMS #7 is shown on Figure 2-2. The 

regional geology and groundwater features are shown on Figure 2-3. The regional surface water 

features and drainage basins are shown on Figure 2-4. Groundwater elevations and contours are 

presented on Figure 2-5.

2.2.1 Geology

Norfolk FMS #7 lays within the middle of the Great Plains. The soil present at the Norfolk 

FMS #7 is a shallow low-permeability layer that is typically between 3 and 8 ft thick, although 

the depth and thickness vary considerably under the Facility. This soil layer impacts groundwater

flow under the Facility. The surface geology at the facility consists of unconsolidated Quaternary 

sediments, which consist of gravel, silts, and clays. These sediments can range in thickness in 

Madison County, from slightly less than 50 ft in the Elkhorn River Valley to as much as 400 ft in 

the uplands area. Under this layer, there are rock layers that are roughly 59 to 69 ft thick. The 

uppermost bedrock unit underlying the Norfolk FMS #7 is the Cretaceous age Niobrara Chalk 

(AECOM 2020).

During the SI, the soil underling the Facility was found to be generally composed of organic silt, 

very fine sand, low plasticity silty sand, and some medium to high plasticity sandy clays. The

borings were completed at depths ranging from 20 to 22 ft below ground surface (bgs). Samples 

for grain size analyses were collected at one location (AOI01-03) and analyzed via American 
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Society for Testing and Materials (ASTM) Method D-422. The results indicate that the soil 

samples are comprised primarily of sand (77.5 Percent [%]) and silt and clay (22.5%). Boring 

logs are presented in Appendix D and grain size results are presented in Appendix E.

2.2.2 Hydrogeology

The Norfolk FMS #7 has a groundwater table that is approximately 18 to 20 ft bgs, although 

history shows it has been shallower at depths ranging from 5 to 15 ft bgs. It is common to see 

groundwater elevation fluctuate approximately 5 ft due to high uses of irrigation and occasional 

droughts. The most fluctuation recorded was a 10-ft change between 2006 and 2009, but it was 

not significant enough to raise the groundwater level to intercept the shallow low-permeability 

soil layer. This layer is within the vadose zone throughout the year, except on a rare occasion of 

an elevated water table (AECOM 2020).

The primary sources of groundwater in Madison County are from the sand and gravels that

overly the bedrock in most of the county. The Niobrara Chalk is a significant source of water, as

water can be obtained from fractures, crevices, and solution cavities within the chalk. Although

as adequate amounts of water can generally be obtained from the Quaternary sands and gravels

in the area, the Niobrara Chalk is not exclusively used (AECOM 2020).

There is one domestic water well located within the boundary of the Facility. This domestic well

is used to supply drinking water to the facility. The well depth is approximately 60 ft deep with a 

water pumping level of 29 ft. The well is located on the south side of the facility. There are

several additional domestic, commercial/industrial, monitoring, livestock, and unknown well 

types located cross-gradient and within a 1-mile radius of the Facility (AECOM 2020) (Figure 

2-3).

Depths to water measured in December 2021 during the SI ranged from approximately 17 to 21

ft bgs during synoptic water level measurements. Total boring completion depths, to 

accommodate temporary well installation, ranged from 20 to 22 ft bgs. Groundwater elevation 

contours from the SI are presented on Figure 2-5 and indicate the groundwater flow direction at 

Norfolk FMS #7 is primarily to the north based on calculated groundwater elevations (Figure 2-

5). 

2.2.3 Hydrology

The Facility is approximately 2,300 ft south of the Elkhorn River. The Elkhorn River, including 

all its tributaries, drains nearly 94 % of Madison County. The Elkhorn River generally flows 

from west to east and eventually drains into the Platte River approximately 80 miles from the 

Facility. Surface water flow direction at the facility is to the north towards the Elkhorn River

(Figure 2-4). The Facility is located in the Elkhorn River drainage area. Stormwater from the

Facility drains into the Elkhorn River through various drainage ditches on the northern side. In

addition, surface water drains off the Facility into ponds or lakes surrounding the area before

ultimately flowing in the Elkhorn River (AECOM 2020).
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2.2.4 Climate

The climate at Norfolk FMS #7 has four defined seasons in which summers are warm and

humid, winters are typically dry with light snow, and spring months tend to produce high

amounts of thunderstorms and even tornadoes. Temperatures vary from average highs of 

60.5 degrees Fahrenheit (°F) to average lows of 38°F. The average annual temperature is 

49.25°F. Average precipitation is 27.42 inches of rain (AECOM 2020).

2.2.5 Current and Future Land Use

The Norfolk FMS #7 is a fenced, controlled access facility and is adjacent to the Norfolk 

Regional Airport. Reasonably anticipated future land use is not expected to change from the 

current land use; however, future infrastructure improvements, land acquisitions, and land use 

controls are unknown (AECOM 2020). 

2.2.6 Sensitive Habitat and Threatened/Endangered Species

A wildlife survey has not occurred at the Facility, and the Facility does not have any significant 

areas of habitat. The following species have not been identified at the Facility but may be present 

in the surrounding area.

The following species are listed as federally endangered, threatened, proposed, and/or candidate 

species in Madison County, Nebraska (U.S. Fish and Wildlife Service 2022):

• Birds: Piping Plover (Charadrius melodus) – Federally Threatened; Whooping Crane 

(Grus americana) – Federally Endangered

• Fishes: Pallid Sturgeon (Scaphirhynchus albus) – Federally Endangered; Topeka Shiner 

(Notropis topeka) – Federally Endangered

• Flowering Plants: Western Prairie Fringed Orchid (Platanthera praeclara) – Federally 

Threatened

• Insects: Monarch Butterfly (Danaus plexippus) – Federal Candidate

• Mammal: Northern Long-eared Bat (Myotis septentrionalis) – Federally Threatened.

2.3 HISTORY OF PFAS USE

One potential PFAS release area was identified at the Facility during the PA where aqueous filmforming foam (AFFF) was stored (AECOM 2020). Interviews and records obtained during the 

PA indicate that the Firetruck Storage Building stores four firetrucks, two of which are capable 

of holding aqueous AFFF. Additionally, eight 55-gallon drums of AFFF are stored within the 

building. A description of the AOI is presented in Section 3.
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Figure 2-1

Facility Location

Norfolk FMS #7

3

0 1

Miles

Facility Data

Facility Boundary

NE

^_

Data Sources:

ESRI 2020

AECOM 2020

Date:........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N
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Figure 2-2

Topography

Norfolk FMS #7

3

0 1

Miles

Facility Data

Facility Boundary

NE

^_

Data Sources:

ESRI 2020

AECOM 2020

Date:........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N
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Figure 2-3

Groundwater Features

<! <!

<!

<!

<!

<!

<!

<! <! <!

<!

<!

<!

<!

<!

<!

<!<!

<!

<! <!

<!

<!

<!

!<!<

<! <! <! <! <! <!

<! <! <!<! <!

<!

<!

<!

<!

Elkhorn River

Medelmans

Lake

3

0 0.5

Miles

Facility Data

Facility Boundary

Well Type

<! Domestic

<! Commercial/Industrial

<! Livestock

<! Monitoring/Observation/Recovery

<! Other/Unknown

Hydrology/Hydrogeology

Inferred Groundwater Flow Direction

Intermittent Creek/Stream

Waterbody NE

^_

Data Sources:

ESRI 2020

AECOM 2020

Date:........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N
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Figure 2-4

Surface Water Features

Elkhorn River

Medelmans

Lake

Medelmans Lake-Elkhorn River Watershed

Hadar Creek-North Fork

Elkhorn River Watershed 3

0 0.5

Miles

Facility Data

Facility Boundary

Hydrology/Hydrogeology

Surface Water Flow Direction

Intermittent Creek/Stream

Waterbody

Watershed Boundary

NE

^_

Data Sources:

ESRI 2020

AECOM 2020

Date:........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N
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Figure 2-5

Groundwater Elevations, December 2021

A@

AOI 1

Firetruck Storage Building

NFMS-PW-01

AOI01-02

1513.23

NFMS-02

1513.72

NFMS-01

1513.79

AOI01-03

1513.6

AOI01-01

1513.3

NFMS-03

1511.68

1513

1512

3

0 200

Feet

Facility Data

Facility Boundary

Areas of Interest

Potential PFAS Release

Hydrogeology

Groundwater Flow Direction

Groundwater Contour

Interval (1 Foot)

Dashed where Inferred

NE

^_

Data Sources:

ESRI 2020

AECOM 2020

Date:........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N
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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, one potential release area was identified at 

Norfolk FMS #7 and identified as AOI 1 Firetruck Storage Building. The potential release area

and Norfolk Regional Airport (a potential adjacent source) are shown on Figure 3-1.

3.1 AOI 1 – FIRETRUCK STORAGE BUILDING

The Norfolk FMS #7 Firetruck Storage Building is located at the south end of the Facility. The 

Firetruck Storage Building holds four permanent firetrucks. Of the four firetrucks, two can hold 

only water, while the other two have the capability of holding AFFF. According to the PA, the 

firetrucks that have the capability to hold AFFF have never been filled with AFFF concentrate. 

The firetrucks are 15 years old and are tested annually for hose pressure with water only. There 

were no reported leaks from any of the firetrucks dating back to 2014. Based on interviewee 

knowledge, the firetrucks were only stored at the Facility and no maintenance on the firetrucks 

occurred. There are floor drains in the Firetruck Storage Building leading to an oil/water 

separator, which discharges to the stormwater system on the north side of the Facility (AECOM 

2020).

Additionally, the Firetruck Storage Building contains eight 55-gallon drums of 3% AFFF. It

could not be confirmed if the firetrucks and bulk AFFF are used at the Facility. The personnel 

with direct knowledge of the activities at the Facility prior to 2014 were on military deployment

during the PA; therefore, information prior to 2014 regarding the AFFF is unknown (AECOM 

2020).

There are ABC handheld fire extinguishers present at the Facility. No AFFF fire extinguishers

were ever present at the facility (AECOM 2020).
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Figure 3-1

Areas of Interest

<!

Firetruck Storage Building AOI 1

3

0 500

Feet

Facility Data

Facility Boundary

Area of Interest

Potential PFAS Release

Well Type

<! Domestic

Hydrology/Hydrogeology

Surface Water Flow Direction

Groundwater Flow Direction

Waterbody NE

^_

Data Sources:

ESRI 2020

AECOM 2020

<! <!

<!

<!

<!

Norfolk

Regional Airport

Date:........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N
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4. PROJECT DATA QUALITY OBJECTIVES

As identified during the data quality objective (DQO) process and outlined in the SI Uniform 

Federal Policy (UFP) – Quality Assurance Project Plan (QAPP) Addendum (EA 2021a), the 

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

identified in the PA. For each AOI, ARNG determines if further investigation is warranted, a 

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

warranted. This SI evaluated groundwater and soil for presence or absence of relevant

compounds at the AOI.

4.1 PROBLEM STATEMENT

ARNG will recommend an AOI for remedial investigation (RI) if site-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 the Norfolk FMS #7 (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 2021a)

• 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 2-1). 

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

required, the proper stakeholders will be notified, and necessary rights of entry will be obtained 

by ARNG with property owner(s). Temporal boundaries were limited to the earliest available 

time field resources were available to complete the study.

4.4 ANALYTICAL APPROACH

Samples were analyzed by Eurofins Lancaster Laboratories Environmental LLC, accredited 

under the Department of Defense (DoD) Environmental Laboratory Accreditation Program 

(ELAP); Accreditation No. 0001.01 and the National Environmental Laboratory Accreditation 

Program (NELAP) (Commonwealth of Pennsylvania Department of Environmental Protection, 

Accreditation No. 36-00037). PFAS data underwent 100% Stage 2B validation in accordance 

with the DoD General Data Validation Guidelines (2019b) and DoD Data Validation Guidelines 

Module 3: Data Validation Procedure of Per- and Polyfluoroalkyl Substances Analysis by 

Quality Systems Manual (QSM) Table B-15 (2020).
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PFAS data were compared to applicable SLs and decision rules as defined in the UFP-QAPP 

Addendum (EA 2021a). 

4.5 DATA USABILITY ASSESSMENT

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

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

validation 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, 2019b, USEPA 2017).

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

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

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

requirements of the UFP-QAPP Addendum (EA 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, Norfolk Facility Maintenance Shop #7, Nebraska, 

dated September 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 2020a)

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

Addendum, Norfolk Facility Maintenance Shop #7, Nebraska, dated October 2021 (EA 

2021a)

• Final Programmatic Accident Prevention Plan, Revision 1, dated November 2020 (EA 

2020b)

• Final Site Safety and Health Plan, Norfolk Facility Maintenance Shop #7, Nebraska, 

dated March 2021 (EA 2021b) 

The SI field activities were conducted on 8 and 9 December 2021 and consisted of DPT boring, 

hand auger boring, soil sample collection, temporary monitoring well installation, and grab 

groundwater sample collection. Field activities were conducted in accordance with the UFPQAPP Addendum (EA 2021a), except as noted in Section 5.9. Field Change Request Forms can 

be found in Appendix B4. 

The following samples were collected during the SI and analyzed for a subset of 24 PFAS 

compounds via Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS) compliant 

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

• Twenty (20) soil samples from six soil boring and one hand auger locations

• Six (6) grab groundwater samples from six temporary well locations

• Six (6) quality assurance (QA)/quality control (QC) samples

Figure 5-1 provides the sample locations for all media across the Facility. Table 5-1 presents the 

list of samples collected for each 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 is 

provided in Appendix B3. Photographs were not collected during this field effort. 

5.1 PRE-INVESTIGATION ACTIVITIES

In preparation for the SI field activities, project team members participated in Technical Project 
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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 (EM) 200-1-2 

(Department of Army 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 September 2021, prior to SI field activities 

with stakeholders. The combined TPP Meeting 1 and 2 was conducted in general accordance 

with EM 200-1-2. The stakeholders for this SI include ARNG G-9, NEARNG, USACE, and the 

Nebraska Department of Environment and Energy 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 2022). 

A TPP Meeting 3 was held on 15 August 2023 to discuss the results of the SI. Meeting minutes 

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

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

5.1.2 Utility Clearance

The 811 Nebraska Dig line was contracted to notify them of intrusive work at the Facility. Utility 

clearance was performed at each of the proposed boring locations on 1 December 2021 with 

input from the EA field team. Additionally, the first 5 ft of each boring were pre-cleared by EA’s 

drilling subcontractor, Plains Environmental Services, 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

A sample from a potable water source at EA’s office in Lincoln, Nebraska, was collected on 10 

November 2021, prior to mobilization. Results of the sample confirmed this source to be 

acceptable for use in this investigation; therefore, it was used throughout the field activities.

Specifically, the same was analyzed for PFAS by LC/MS/MS compliant with QSM Version 5.3

Table B-15. These results can be found in Appendix E.

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 (Appendix A) to the

Programmatic UFP-QAPP (EA 2020a).
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5.2 SOIL BORINGS AND SOIL SAMPLING

Soil samples were collected using a hand auger (0 to 2 ft bgs) and via DPT drilling methods in 

accordance with Standard Operating Procedure 047 Direct-Push Technology Sampling (EA 

2021a). A GeoProbe® 5410 truck-mounted dual-tube sampling system was used to collect 

continuous soil cores to the target depth. A hand auger was used to remove soil from the top 5 ft 

of the boring in compliance with utility clearance procedures.

Three discrete soil samples were collected for chemical analysis from each soil boring: one 

sample at the surface (0 to 2 ft bgs) and two subsurface soil samples. One boring (AOI01-03) 

included an additional discrete subsurface soil sample (i.e., four total samples from this boring), 

which was inadvertently analyzed for PFAS from the 17–18 ft bgs interval that was sampled for 

geotechnical analyses. One subsurface soil sample was collected approximately 1 ft above the 

groundwater table, and one was collected at the mid-point between the surface and the 

groundwater table (not to exceed 15 ft bgs). Groundwater was encountered at depths ranging 

from 14 to 18 ft bgs during drilling. Total boring completion depths, to accommodate temporary 

well installation, ranged from 20 to 22 ft bgs. 

All soil sample locations are shown on Figure 5-1, and boring sample depths are provided in 

Table 5-1. The soil boring locations were selected based on the AOI information provided in 

the PA (AECOM 2020) and as agreed upon by stakeholders during the TPP and review of the 

UFP-QAPP Addendum (EA 2021a). 

During the drilling, the soil cores were continuously logged for lithological descriptions by a 

field geologist using the Unified Soil Classification System. A photoionization detector (PID) 

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, PID concentrations, 

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

recorded. The boring logs are provided in Appendix D.

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 (COC) procedures to the laboratory and 

analyzed for PFAS (LC/MS/MS compliant with QSM Version 5.3 Table B-15). One sample per

AOI was additionally analyzed for total organic compound (TOC) (USEPA Method 9060A), pH 

(USEPA Method 9045D), and grain size (ASTM D422) in accordance with the UFP-QAPP 

Addendum (EA 2021a). 

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

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

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

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

samples, one equipment blank was collected per day and analyzed for the same parameters as the 

soil samples. A temperature blank was placed in each cooler to ensure that samples were 

preserved at or below 6 degrees Celsius (°C) during shipment. 
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DPT borings were converted to temporary wells, which were subsequently abandoned after 

sampling and surveying in accordance with the UFP-QAPP Addendum (EA 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® 5410 truck-mounted dual-tube sampling 

system. Once the borehole was advanced to the desired depth, a temporary well was constructed 

of a 5-ft 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, after a period of time following well installation to allow 

groundwater to infiltrate and recharge the temporary well intervals, using a peristaltic pump with 

PFAS-free HDPE tubing. Each sample was collected in laboratory-supplied PFAS-free HDPE 

bottles and labeled using a PFAS-free marker or pen. The temporary wells were purged at a rate 

determined in the field to reduce turbidity and draw down prior to sampling. Water quality 

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

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

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

Samples were packaged on ice and transported via FedEx under standard COC procedures to the 

laboratory and analyzed for PFAS by LC/MS/MS compliant with QSM Version 5.3 Table B-15 

in accordance with the UFP-QAPP Addendum (EA 2021a). 

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

the accompanying samples. MS/ MSDs were collected at a rate of 5% and analyzed for the same 

parameters as the accompanying samples. One field blank (FB) and one equipment blank were

collected in accordance with the UFP-QAPP Addendum (EA 2021a). A temperature blank was 

placed in each cooler to ensure that samples were preserved at or below 6°C during shipment. 

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

accordance with the UFP-QAPP Addendum (EA 2021a) using bentonite chips and surface 

completion material (native topsoil material) at completion of sampling activities.

5.4 SYNOPTIC WATER LEVEL MEASUREMENTS

Groundwater levels were used to monitor facility-wide groundwater elevations and assess 

groundwater flow. Synoptic water level elevation measurements were collected from the newly 

installed temporary monitoring wells, taken from the survey mark on the northern side of the 

well casing. Groundwater elevation data are provided in Table 5-3. 
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5.5 SURVEYING

The northern side of each new temporary well casing was surveyed using a Trimble R10 realtime kinematic differential global positioning system. Positions were collected in the applicable 

Universal Transverse Mercator zone projection with World Geodetic System 1984 datum 

(horizontal) and North American Vertical Datum of 1988 (vertical). Surveying data were

collected on 9 December 2021 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. PFAS IDW generated during the SI is considered non-hazardous waste and 

was managed in accordance with the UFP-QAPP Addendum (EA 2021a). 

Soil IDW (i.e., soil cuttings) was left in place at the point of source. The soil cuttings were 

distributed on the downgradient side of the borehole. The liquid IDW (i.e., purge water, 

development water, and decontamination fluids) generated during the SI activities was 

containerized in one 55-gallon drum, which was labeled and secured in a building along the 

southern Facility boundary fence. The liquid IDW container remains at the Facility awaiting 

disposal following USACE, ARNG, and regulatory approval of a Letter Work Plan for IDW 

Disposal. The Letter Work Plan will be submitted for review and approval upon issuance of the 

Draft Final SI Report.

Other solids such as spent personal protective equipment, plastic sheeting, tubing, rope, unused 

monitoring well construction materials, and other environmental media generated during the 

field activities were disposed of at a licensed solid waste landfill. 

5.7 LABORATORY ANALYTICAL METHODS

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

at Eurofins Lancaster Laboratories Environmental, LLC, in Lancaster, Pennsylvania, a DoD 

ELAP and National Environmental Laboratory Accreditation Program-certified laboratory.

A select number of soil samples were also analyzed for TOC using USEPA Method 9060A, pH 

by USEPA Method 9045D, and grain size by ASTM D422.

5.8 DEVIATIONS FROM UFP-QAPP ADDENDUM

Deviations from the UFP-QAPP Addendum occurred based on field conditions. These deviations 

were discussed between EA, ARNG, and USACE. One deviation from the UFP-QAPP 

Addendum is noted below: 

• AOI01-HA-01: This surface soil sampling location was moved to a grassy area that was 

more in line with the preferential drainage pathway from the potential release associated 

with the Firetruck Storage Building. This change is noted in the Field Change Request 

Form provided in Appendix B4.
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An additional deviation occurred that was not documented on a Field Change Request Form. 

Photographs of field activities were not collected during the SI; therefore, no photographic log is 

presented in this SI report. 

Table 5-1. Samples by Medium

Norfolk FMS #7, Norfolk, Nebraska

Site Inspection Report

Sample 

Identification

Sample Collection 

Date

Sample 

Depth

(ft bgs)

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

Comments

Soil Samples

AOI01-01-SB-0-2 12/09/2021 0-2 X

AOI01-11-SB-0-2 12/09/2021 0-2 X Field duplicate of AOI01-01-SB-0-2

AOI01-01-SB-7-8 12/09/2021 7-8 X

AOI01-01-SB-15-16 12/09/2021 15-16 X

AOI01-02-SB-0-2 12/09/2021 0-2 X

AOI01-02-SB-8-9 12/09/2021 8-9 X

AOI01-02-SB-16-17 12/09/2021 16-17 X

AOI01-13-SB-0-2 12/09/2021 0-2 X Field duplicate of AOI01-03-SB-0-2

AOI01-03-SB-0-2 12/09/2021 0-2 X

AOI01-03-SB-7-8 12/09/2021 7-8 X

AOI01-03-SB-14-15 12/09/2021 14-15 X

AOI01-03-SB-17-18 12/09/2021 17-18 X X X X pH/TOC and grainsize

NFMS-01-SB-0-2 12/09/2021 0-2 X

NFMS-01-SB-6-7 12/09/2021 6-7 X MS/MSD

NFMS-01-SB-13-14 12/09/2021 13-14 X

NFMS-02-SB-0-2 12/09/2021 0-2 X

NFMS-02-SB-6-7 12/09/2021 6-7 X

NFMS-02-SB-13-14 12/09/2021 13-14 X

NFMS-03-SB-0-2 12/09/2021 0-2 X

NFMS-03-SB-6-7 12/09/2021 6-7 X

NFMS-03-SB-14-15 12/09/2021 14-15 X

AOI01-HA-01-0-2 12/09/2021 0-2 X

Groundwater Samples

AOI01-01-GW 12/09/2021 - X

AOI01-11-GW 12/09/2021 - X Field duplicate of AOI01-01-GW

AOI01-02-GW 12/09/2021 - X

AOI01-03-GW 12/09/2021 - X

NFMS-01-GW 12/09/2021 - X

NFMS-02-GW 12/09/2021 - X

NFMS-03-GW 12/09/2021 - X

Blank Samples/Source Water

NFMS-FB-12092021 12/09/2021 - X Field blank

NFMS-EB-12092021 12/09/2021 - X Equipment blank

DECON_TEST_111021 11/10/2021 - X Source Water

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

Norfolk FMS #7, Norfolk, Nebraska

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Area of Interest Boring ID

Soil Boring Depth

(ft bgs)

Temporary Well 

Screen Interval

(ft bgs)

1

AOI01-01 22 16-21

AOI01-02 22 17-22

AOI01-03 20 15-20

Facility Boundary

NFMS-01 20 13-18

NFMS-02 20 13-18

NFMS-03 20 15-20

Table 5-3. Groundwater Elevations

Norfolk FMS #7, Norfolk, Nebraska

Site Inspection Report

Temporary 

Monitoring Well 

ID

Top of Casing Elevation

(ft amsl)

Depth to Water

(ft btoc)

Depth to Water

(ft bgs) Groundwater Elevation

(ft amsl)

AOI01-01 1534.35 21.05 18.51 1513.30

AOI01-02 1534.20 20.97 18.14 1513.23

AOI01-03 1531.93 18.33 17.83 1513.60

NFMS-01 1532.58 18.79 16.69 1513.79

NFMS-02 1531.12 17.4 15.10 1513.72

NFMS-03 1529.15 17.47 16.54 1511.68

Notes:

amsl = Above mean sea level 

bgs = Below ground surface

btoc = Below top of casing

ft = feet

ID = Identification
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Figure 5-1

Site Inspection Sample Locations

<!

AOI01-HA-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

3

0 200

Feet

Facility Data

Facility Boundary

Areas of Interest

Potential PFAS Release

Sample Locations

DPT Boring

<! Domestic Well

Hand Auger

Hydrogeology

Groundwater Flow Direction

NE

^_

Data Sources:

ESRI 2020

AECOM 2020

Date:........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N
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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 the AOI and boundary areas is provided 

in Sections 6.3 and 6.4. Tables 6-2 through 6-5 present results for the relevant compounds in 

soil and groundwater. Tables that contain all results are provided in Appendix E, and the 

laboratory reports are provided in Appendix F.

6.1 SCREENING LEVELS

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

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

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

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

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

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

on Table 6-1.

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

Analyte

Residential

(Soil)

(μg/kg)1

0 to 2 ft bgs

Industrial / Commercial

Composite Worker

(Soil)

(μg/kg) 1

2 to 15 ft bgs

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. 2022. Risk-Based Screening Levels in Groundwater and Soil using 

EPA’s Regional Screening Level Calculator. Hazard Quotient=0.1. July 2022. 

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

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

during the PA and revised based on SI findings, the presence of HFPO-DA is not anticipated at the 

facility because HFPO-DA is generally not a component of MIL-SPEC AFFF and based on its history 

including distribution limitations that restricted use of GenX, it is generally not a component of other 

products the military used. In addition, it is unlikely that GenX would be an individual chemical of 

concern in the absence of other PFAS.

μg/kg = Microgram(s) per kilogram

ng/L = Nanogram(s) per liter

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 

ft bgs) and the industrial/commercial worker scenario is applied to shallow and deep subsurface 

soil results (2 to 15 ft bgs). The SLs are not applied to deep subsurface soil results (greater than 

15 ft bgs) because 15 ft is the anticipated limit of construction activities. 
Site Inspection Report

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6.2 SOIL PHYSICOCHEMICAL ANALYSES

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

are important for evaluating transport through the soil medium. Appendix E contains the results 

of the TOC and pH sampling. 

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

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

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

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

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

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

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

and Higgins 2013). When sufficient organic carbon is present, organic carbon normalized 

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

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

sorption to solid phases (ITRC 2018). 

6.3 AOI 1 

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

AOI 1, which includes the Firetruck Storage Building. The detected compounds are summarized 

in Tables 6-2 through 6-5. Soil and groundwater results are presented on Figures 6-1 through 

6-7.

6.3.1 AOI 1 – Soil Analytical Results

Figures 6-1 through 6-5 present the ranges of detections in soil. Tables 6-2 through 6-4

summarize the soil results. 

Soil was sampled at three boring locations associated with the potential release area at AOI 1. 

Soil was sampled from three intervals at each of the boring locations: surface (0–2 ft bgs), 

shallow subsurface soil (less than 9ft bgs), and deep subsurface soil (up to 18 ft bgs). One boring 

(AOI01-03) included an additional discrete subsurface soil sample (i.e., four total samples from 

this boring). Additionally, one surface soil sample was collected using a hand auger from 0-2 ft 

bgs.

PFOA was detected in the surface interval at boring AOI01-02 (0.22 J μg/kg) and boring AOI01-

03 (1.8 μg/kg) below the SL of 19 μg/kg. PFNA was detected in the surface interval at boring 

AOI01-03 (1.3 μg/kg) below the SL of 19 μg/kg. PFBS, PFHxS, and PFOS were not detected in 

the surface soil samples in AOI 1.

A total of seven subsurface soil samples were collected from AOI 1 (four shallow subsurface and 

three deep subsurface samples). One relevant compound was detected in subsurface soil. PFOA 

was detected in one subsurface sample, AOI01-03-SB-7-8 (0.22 J μg/kg) below the SL of 250 
Site Inspection Report

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μg/kg. PFBS, PFHxS, PFNA, and PFOS were not detected in the subsurface soil samples in AOI 

1.

6.3.2 AOI 1 – Groundwater Analytical Results 

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

groundwater results. 

Groundwater samples were collected from three temporary wells at AOI 1 during the SI

activities. PFOA was detected (1.5 J ng/L) in groundwater at one temporary monitoring well 

location (AOI01-03) below the SL (6 ng/L). PFOS was detected (0.69 J ng/L) in one temporary 

monitoring well location (AOI01-01) below the SL (4 ng/L). PFBS was detected in groundwater 

at concentrations ranging from 0.7 J ng/L (AOI01-03) to 6.2 ng/L (AOI01-01) in all three wells

below the SL (601 ng/L). PFHxS and PFNA were not detected in groundwater at any location.

6.3.3 AOI 1 – Conclusions

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

and PFOA were detected in groundwater samples below their respective SLs. Therefore, further 

evaluation of AOI 1 is not warranted.

6.4 BOUNDARY SAMPLE LOCATIONS

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

samples collected at Facility boundary. The detected compounds are summarized in Tables 6-2

through 6-5. Soil and groundwater results are presented on Figures 6-1 through 6-7.

6.4.1 Boundary Locations – Soil Analytical Results

Figures 6-1 through 6-5 present the ranges of detections in soil. Tables 6-2 through 6-4

summarize the soil results. 

Soil boundary sample locations were comprised of three boring locations (NFMS-01 through 

NFMS-03) along the facility boundary. Boring locations NFMS-01 and NFMS-02 were along 

the southern/upgradient boundary of the facility. Boring location NFMS-03 was along the 

northern/downgradient boundary of the facility. Soil was sampled from three intervals in the 

three borings; surface (0–2ft bgs), shallow subsurface soil (less than 9 ft bgs), and deep

subsurface soil (less than 15 ft bgs). 

None of the five relevant compounds were detected in soil samples taken from the facility 

boundary boring locations.

6.4.2 Boundary Locations – Groundwater Analytical Results 

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

groundwater results.
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Groundwater samples were collected from two temporary well locations along the 

southern/upgradient facility boundary (NFMS-01 and NFMS-02). None of the five relevant 

compounds were detected in groundwater samples taken from the southern/upgradient facility 

boundary temporary well locations. A groundwater sample was collected from one temporary 

well location along the northern/downgradient facility boundary (NFMS-03). PFBS was detected 

at a concentration of 1.3 J ng/L below the SL (601 ng/L) at NFMS-03. None of the other four 

relevant compounds were detected in the groundwater sampling taken from the 

northern/downgradient facility boundary temporary well location.

6.4.3 Conclusions

Based on the results of the SI, PFBS was detected in groundwater at the northern/downgradient 

temporary well location below the SL Therefore, further evaluation of the facility boundary to 

determine contribution from potential upgradient sources is not warranted.
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Analyte Screening Level1,2 Unit Result Qual Result Qual Result Qual Result Qual Result Qual

PFAS by LC/MS/MS compliant with QSM Version 5.3 Table B-15 (μg/kg)

Perfluorobutanesulfonic acid (PFBS) 1,900 μg/kg ND U ND U ND U ND U ND U

Perfluorohexanesulfonic acid (PFHxS) 130 μg/kg ND U ND U ND U ND U ND U

Perfluorononanoic acid (PFNA) 19 μg/kg ND U ND U ND U 1.3 1.2

Perfluorooctanesulfonic acid (PFOS) 13 μg/kg ND U ND U ND U ND U ND U

Perfluorooctanoic acid (PFOA) 19 μg/kg ND U ND U 0.22 J 1.8 1.4

Notes:

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

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

U = The analyte was not detected at a level greater than or equal to the adjusted detection level. 

Qual = Qualifier.

J = Estimated concentration.

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

Site Inspection Report, NFMS #7

2. The Screening Levels for soil are based on a residential scenario for incidental ingestion of contaminated soil.

0-2

μg/kg = Microgram(s) per kilogram.

Location ID

Sample Date

Parent Sample ID

Sample Name

Depth (ft bgs) 0-2

ft bgs = Feet below ground surface. 

12/9/2021 12/9/2021

0-2

12/9/2021

AOI01-01 AOI01-02 AOI01-03 AOI01-03

AOI01-03-SB-0-2

AOI01-01-SB-0-2

AOI01-01-SB-0-2

AOI01-11-SB-0-2 AOI01-02-SB-0-2 AOI01-03-SB-0-2 AOI01-13-SB-0-2

AOI01-01

0-2 0-2

12/9/2021 12/9/2021

EA Engineering, Science, and Technology, Inc., PBC
Site Inspection Report

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Analyte Screening Level1,2 Unit Result Qual Result Qual Result Qual Result Qual

PFAS by LC/MS/MS compliant with QSM Version 5.3 Table B-15 (μg/kg)

Perfluorobutanesulfonic acid (PFBS) 1,900 μg/kg ND U ND U ND U ND U

Perfluorohexanesulfonic acid (PFHxS) 130 μg/kg ND U ND U ND U ND U

Perfluorononanoic acid (PFNA) 19 μg/kg ND U ND U ND U ND U

Perfluorooctanesulfonic acid (PFOS) 13 μg/kg ND U ND U ND U ND U

Perfluorooctanoic acid (PFOA) 19 μg/kg ND U ND U ND U ND U

Notes:

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

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

U = The analyte was not detected at a level greater than or equal to the adjusted detection level. 

Qual = Qualifier.

μg/kg = Microgram(s) per kilogram.

ft bgs = Feet below ground surface. 

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

Site Inspection Report, NFMS #7

2. The Screening Levels for soil are based on a residential scenario for incidental ingestion of contaminated soil.

J = Estimated concentration.

12/9/2021 12/9/2021 12/9/2021 12/9/2021

0-2 0-2

NFMS-03-SB-0-2

AOI01-HA

0-2

Parent Sample ID

Sample Date

Location ID NFMS-03

Sample Name

NFMS-01 NFMS-02

AOI01-HA-01-0-2 NFMS-01-SB-0-2 NFMS-02-SB-0-2

Depth (ft bgs) 0-2

EA Engineering, Science, and Technology, Inc., PBC
Site Inspection Report

Norfolk Facility Maintenance Shop #7, Nebraska Version: FINAL

Analyte Screening Level1,2 Unit Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual

PFAS by LC/MS/MS compliant with QSM Version 5.3 Table B-15 (μg/kg)

Perfluorobutanesulfonic acid (PFBS) 25,000 μg/kg ND U ND U ND U ND U ND U ND U ND U

Perfluorohexanesulfonic acid (PFHxS) 1,600 μg/kg ND U ND U ND U ND U ND U ND U ND U

Perfluorononanoic acid (PFNA) 250 μg/kg ND U ND U ND U ND U ND U ND U ND U

Perfluorooctanesulfonic acid (PFOS) 160 μg/kg ND U ND U ND U ND U ND U ND U ND U

Perfluorooctanoic acid (PFOA) 250 μg/kg ND U ND U ND U 0.22 J ND U ND U ND U

Notes:

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

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

U = The analyte was not detected at a level greater than or equal to the adjusted detection level.

Qual = Qualifier.

2. The Screening Levels for soil are based on incidental ingestion of soil in a industrial/commercial worker scenario.

μg/kg = Microgram(s) per kilogram.

J = Estimated concentration.

Depth (ft bgs) 7-8 8-9 14-15 7-8

Parent Sample ID

Sample Date 12/9/2021 12/9/2021

Location ID

Sample Name

AOI01-01 AOI01-02 AOI01-03

AOI01-03-SB-14-15

ft bgs = Feet below ground surface.

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

Site Inspection Report, Norfolk FMS #7

12/9/2021

6-7 6-7 6-7

12/9/2021 12/9/2021

AOI01-03 NFMS-01 NFMS-02

12/9/2021 12/9/2021

NFMS-03

AOI01-01-SB-7-8 AOI01-02-SB-8-9 AOI01-03-SB-7-8 NFMS-01-SB-6-7 NFMS-02-SB-6-7 NFMS-03-SB-6-7

EA Engineering, Science, and Technology, Inc., PBC
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Site Inspection Report

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Analyte Screening Level1,2 Unit Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual

PFAS by LC/MS/MS compliant with QSM Version 5.3 Table B-15 (μg/kg)

Perfluorobutanesulfonic acid (PFBS) 25,000 μg/kg ND U ND U ND U ND U ND U ND U

Perfluorohexanesulfonic acid (PFHxS) 1,600 μg/kg ND U ND U ND U ND U ND U ND U

Perfluorononanoic acid (PFNA) 250 μg/kg ND U ND U ND U ND U ND U ND U

Perfluorooctanesulfonic acid (PFOS) 160 μg/kg ND U ND U ND U ND U ND U ND U

Perfluorooctanoic acid (PFOA) 250 μg/kg ND U ND U ND U ND U ND U ND U

Notes:

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

AOI01-01

AOI01-01-SB-15-16 AOI01-02-SB-16-17 AOI01-03-SB-17-18

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

Site Inspection Report, NFMS #7

Location ID AOI01-02 AOI01-03

Sample Name NFMS-01-SB-13-14 NFMS-02-SB-13-14

NFMS-01 NFMS-02 NFMS-03

NFMS-03-SB-14-15

Sample Date

15-16

12/9/2021

14-15

12/9/2021 12/9/2021 12/9/2021 12/9/2021 12/9/2021

Parent Sample ID

Depth (ft bgs) 16-17 17-18 13-14 13-14

2. The Screening Levels for soil are based on incidental ingestion of soil in a industrial/commercial worker scenario.

ft bgs = Feet below ground surface.

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

Qual = Qualifier.

U = The analyte was not detected at a level greater than or equal to the adjusted detection level.

μg/kg = Microgram(s) per kilogram.

EA Engineering, Science, and Technology, Inc., PBC
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Site Inspection Report

Norfolk Facility Maintenance Shop #7, Nebraska Version: FINAL

Analyte Screening Level1 Unit Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual Result Qual

PFAS by LC/MS/MS compliant with QSM Version 5.3 Table B-15 (ng/L)

Perfluorobutanesulfonic acid (PFBS) 601 ng/L 4.8 6.2 5.5 0.7 J ND U ND U 1.3 J

Perfluorohexanesulfonic acid (PFHxS) 39 ng/L ND U ND U ND U ND U ND U ND U ND U

Perfluorononanoic acid (PFNA) 6 ng/L ND U ND U ND U ND U ND U ND U ND U

Perfluorooctanesulfonic acid (PFOS) 4 ng/L 0.69 J ND U ND U ND U ND U ND U ND U

Perfluorooctanoic acid (PFOA) 6 ng/L ND U ND U ND U 1.5 J ND U ND U ND U

Notes:

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

ND = Analyte not detected above the LOD (LOD values are presented in Appendix F). ng/L = Nanogram(s) per liter.

Qual = Qualifier.

U = The analyte was not detected at a level greater than or equal to the adjusted detection level.

Values exceeding the Screening Level are shaded gray.

NFMS-02

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

Site Inspection Report, NFMS #7

Sample Name

Location ID

Parent Sample ID

NFMS-03

AOI01-01-GW AOI01-11-GW AOI01-02-GW AOI01-03-GW NFMS-01-GW NFMS-02-GW NFMS-03-GW

AOI01-01

J = Estimated concentration.

ng/L = Nanogram(s) per liter.

AOI01-02 AOI01-03 NFMS-01

Sample Date

AOI01-01

12/9/2021 12/9/2021 12/9/2021 12/9/2021 12/9/2021 12/9/2021 12/9/2021

AOI01-01-GW

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Site Inspection Report

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Figure 6-1

AOI 1

PFOS Detections in Soil

AOI01-HA-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

3

0 250

Feet

NE

^_

Data Sources:

ESRI 2022

AECOM 2019

Date:.........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N

0 250

Feet

0 250

Feet

Shallow Intermediate Deep

Facility Data

Facility Boundary

Areas of Interest

Potential PFAS Release

Hydrogeology

Groundwater Flow Direction

Notes:

PFOS = Perfluorooctanesulfonic acid

Exceedances of the OSD SL are depicted

with a yellow halo. Depth intervals shown

represent respective sampling position

within a given soil boring location.

> 1,600

> 160 - 1,600

> 13 - 160

> ND - 13

ND (Non-Detect)

PFOS Results (μg/Kg)

> 1,600

> 160 - 1,600

> 13 - 160

> ND - 13

ND (Non-Detect)

PFOS Results (μg/Kg)

> 1,600

> 160 - 1,600

> 13 - 160

> ND - 13

ND (Non-Detect)

PFOS Results (μg/Kg)
Site Inspection Report

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This page intentionally left blank
Figure 6-2

AOI 1

PFOA Detections in Soil

AOI01-HA-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

3

0 250

Feet

NE

^_

0 250

Feet

0 250

Feet

Shallow Intermediate Deep

Army National Guard Site Inspections

Site Inspection Report

Norfolk FMS #7, Nebraska

Data Sources:

ESRI 2022

AECOM 2019

Facility Data

Facility Boundary

Areas of Interest

Potential PFAS Release

Hydrogeology

Groundwater Flow Direction

Notes:

PFOA = Perfluorooctanoic acid

Exceedances of the OSD SL are depicted

with a yellow halo. Depth intervals shown

represent respective sampling position

within a given soil boring location.

> 2,500

> 250 - 2,500

> 19 - 250

> ND - 19

ND (Non-Detect)

PFOA Results (μg/Kg)

> 2,500

> 250- 2,500

> 19 - 250

> ND - 19

ND (Non-Detect)

PFOA Results (μg/Kg)

> 2,500

> 250- 2,500

> 19 - 250

> ND - 19

ND (Non-Detect)

PFOA Results (μg/Kg)

Date:.........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N
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This page intentionally left blank
Figure 6-3

AOI 1

PFBS Detections in Soil

AOI01-HA-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

3

0 250

Feet

NE

^_

0 250

Feet

0 250

Feet

Shallow Intermediate Deep

Army National Guard Site Inspections

Site Inspection Report

Norfolk FMS #7, Nebraska

Data Sources:

ESRI 2022

AECOM 2019

Facility Data

Facility Boundary

Areas of Interest

Potential PFAS Release

Hydrogeology

Groundwater Flow Direction

Notes:

PFBS = Perfluorobutanesulfonic acid

Exceedances of the OSD SL are depicted

with a yellow halo. Depth intervals shown

represent respective sampling position

within a given soil boring location.

> 25,000

> 1,900 - 25,000

> 10 - 1,900

> ND - 10

ND (Non-Detect)

PFBS Results (μg/Kg)

> 25,000

> 1,900 - 25,000

> 10 - 1,900

> ND - 10

ND (Non-Detect)

PFBS Results (μg/Kg)

> 25,000

> 1,900 - 25,000

> 10 - 1,900

> ND - 10

ND (Non-Detect)

PFBS Results (μg/Kg)

Date:.........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N
Site Inspection Report

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This page intentionally left blank
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Site Inspection Report

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Figure 6-4

AOI 1

PFHxS Detections in Soil

AOI01-HA-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

3

0 250

Feet

NE

^_

Data Sources:

ESRI 2022

AECOM 2019

0 250

Feet

0 250

Feet

Shallow Intermediate Deep

Facility Data

Facility Boundary

Areas of Interest

Potential PFAS Release

Hydrogeology

Groundwater Flow Direction

Notes:

PFHxS = Perfluorohexanesulfonic acid

Exceedances of the OSD SL are depicted

with a yellow halo. Depth intervals shown

represent respective sampling position

within a given soil boring location.

> 1,600

> 130 - 1,600

> 10 - 130

> ND - 10

ND (Non-Detect)

PFHxS Result (μg/Kg)

> 1,600

> 130 - 1,600

> 10 - 130

> ND - 10

ND (Non-Detect)

PFHxS Result (μg/Kg)

> 1,600

> 130 - 1,600

> 10 - 130

> ND - 10

ND (Non-Detect)

PFHxS Result (μg/Kg)

Date:.........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N
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This page intentionally left blank
Army National Guard Site Inspections

Site Inspection Report

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Figure 6-5

AOI 1

PFNA Detections in Soil

AOI01-HA-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

3

0 250

Feet

NE

^_

Data Sources:

ESRI 2022

AECOM 2019

0 250

Feet

0 250

Feet

Shallow Intermediate Deep

Facility Data

Facility Boundary

Areas of Interest

Potential PFAS Release

Hydrogeology

Groundwater Flow Direction

Notes:

PFNA = Perfluorononanoic acid

Exceedances of the OSD SL are depicted

with a yellow halo. Depth intervals shown

represent respective sampling position

within a given soil boring location.

> 2,500

> 250 - 2,500

> 19 - 250

> ND - 19

ND (Non-Detect)

PFNA Results (μg/Kg)

> 2 ,500

> 250 - 2,500

> 19 - 250

> ND - 19

ND (Non-Detect)

PFNA Results (μg/Kg)

> 2 ,500

> 250 - 2,500

> 19 - 250

> ND - 19

ND (Non-Detect)

PFNA Results (μg/Kg)

Date:.........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N
Site Inspection Report

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This page intentionally left blank
Figure 6-6

AOI 1

PFOA, PFOS and PFBS Detections in Groundwater

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

3

0 250

Feet

NE

^_

0 250

Feet

PFOA PFOS

AOI01-01

AOI01-03

NFMS-02

AOI01-02

NFMS-03

AOI 1

Firetruck Storage Building

NFMS-01

0 250

Feet

PFBS

Notes:

PFOA = Perfluorooctanesulfonic acid

PFOS = Perfluorooctanoic acid

PFBS = Perfluorobutanesulfonic acid

Exceedances of the OSD SL are depicted

with a yellow halo.

Army National Guard Site Inspections

Site Inspection Report

Norfolk FMS #7, Nebraska

Data Sources:

ESRI 2022

AECOM 2019

Facility Data

Facility Boundary

Areas of Interest

Potential PFAS Release

Hydrogeology

Groundwater Flow Direction

> 70

> 40 - 70

> 6 - 40

> ND - 6

ND (Non-Detect)

PFOA Results (ng/L)

> 70

> 40 - 70

> 4 - 40

> ND - 4

ND (Non-Detect)

PFOS Results (ng/L)

> 1,000

> 600 - 1,000

> 100 - 600

> ND - 100

ND (Non-Detect)

PFBS Results (ng/L)

Date:.........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N
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Army National Guard Site Inspections

Site Inspection Report

Norfolk FMS #7, Nebraska

Figure 6-7

PFHxS and PFNA Detections in Groundwater

NFMS-01

NFMS-02

NFMS-03

AOI01-01

AOI01-03

AOI01-02

Firetruck Storage Building

AOI 1

NFMS-01

NFMS-02

NFMS-03

AOI01-01

AOI01-03

AOI01-02

Firetruck Storage Building

AOI 1

3

0 300

Feet

Facility Data

Facility Boundary

Areas of Interest

Potential PFAS Release

Hydrogeology

Groundwater Flow Direction

NE

^_

Data Sources:

ESRI 2020

AECOM 2020

Path: G:\Federal\Nationwide\PFAS\MAES_634250383\PROJECTS\SIReport\Norfolk\NorfolkSIReport.aprx

0 300

Feet

PFHxS PFNA

Notes:

PFHxS = Perfluorohexanesulfonic acid

PFNA = Perfluorononanoic acid

Exceedances of the OSD SL are depicted

with a yellow halo.

> 1,000

> 100 - 1,000

> 39 - 100

> ND - 39

ND (Non-Detect)

PFHxS Result (ng/L)

> 1,000

> 100 - 1,000

> 6 - 100

> ND - 6

ND (Non-Detect)

PFNA Results (ng/L)

Date:.........................January 2023

Prepared By:.............................EA

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

Projection:........WGS 84 UTM 14N
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7. EXPOSURE PATHWAYS

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

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

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

exceedances of the SLs for the relevant compounds and whether the release is more than likely 

attributable to the DoD. A CSM presents the current understanding of the site conditions with 

respect to known and suspected sources, potential transport mechanisms and migration 

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

potentially complete when the following conditions are present:

1. Contaminant source

2. Environmental fate and transport

3. Exposure point

4. Exposure route

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 relevant compounds above the SLs. Areas with an identified potentially complete 

pathway that have detections of the relevant compounds above the SLs may warrant further 

investigation. Although the CSMs indicate whether potentially complete exposure pathways may 

exist, the recommendation for future study in 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., facility staff and visiting soldiers), 

construction workers, trespassers (though unlikely due to restricted access), residents outside the 

facility boundary, and recreational users outside of the facility boundary. 

7.1 SOIL EXPOSURE PATHWAY 

The SI results for relevant compounds in soil were used to determine whether a potentially 

complete pathway exists between the source and potential receptors at AOI 1 based on the 

aforementioned criteria.
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7.1.1 AOI 1 

The Firetruck Storage Building contains eight 55-gallon drums of 3% AFFF. It could not be 

confirmed if the fire trucks and bulk AFFF are used at the Facility. Although there were no 

confirmed releases of AFFF as of 2014, activities prior to 2014 are unknown at this location. 

AOI 1 is comprised of the Firetruck Storage Building, paved surfaces, and limited grassy areas 

surrounding the Firetruck Storage Building. There is no current/active construction underway at 

the Facility; therefore, the current construction worker pathway is considered incomplete.

Although PFNA and PFOA were detected in surface soil, the concentrations were below 

applicable SLs. Additionally, the majority of the facility is covered by buildings or paved areas. 

The areas that are not covered by buildings or pavement are vegetated making it less likely that 

exposure to surface soil will occur. However, facility workers and construction workers could

contact PFAS constituents in surface soil via incidental ingestion or inhalation of dust, and the 

surface soil exposure pathway for facility workers and future construction workers is considered 

potentially complete. The exposure pathways for off-site residents and recreational users to 

surface soil are considered incomplete.

PFOA was additionally detected in shallow subsurface soil at a concentration below the SL. 

Ground disturbing activities to subsurface soil could result in construction worker exposure to 

detectable concentrations of PFOA via incidental ingestion. Therefore, the exposure pathway for 

subsurface soil is potentially complete for the future construction worker. The site 

worker/trespasser activities are anticipated to be limited to surface or near surface soil; therefore, 

the exposure pathway for this receptor group to subsurface soil is considered incomplete. The 

exposure pathways for off-site residents and recreational users to subsurface soil are considered 

incomplete.

PFNA and PFOA were detected in surface soils near the AOI. Stormwater drains into various 

drainage ditches on the northern side of the Facility, but there are no surface water features on 

the site. The Facility is 2,300 ft south of the Elkhorn River. PFAS constituents are water soluble, 

and as a result, it is possible that relevant PFAS compounds could migrate via surface water 

runoff. Based on site conditions (the majority of the facility is covered by buildings or paved 

areas and the remaining areas are vegetated), the exposure pathways for site workers/trespassers 

and future construction workers to surface water and sediment onsite are considered incomplete. 

In addition, the exposure pathways for off-site residents and recreational users of Elkhorn River 

via ingestion of surface water and sediment are considered potentially complete since low level 

concentrations of PFNA and PFOA were detected in surface soil and stormwater drains to the 

northside of the Facility. The CSM for AOI 1 is presented in Figure 7-1.

7.2 GROUNDWATER EXPOSURE PATHWAY

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

exists between the source and potential receptors based on the aforementioned criteria.
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7.2.1 AOI 1 

PFOS and PFOA were each detected in groundwater collected from one temporary well 

associated with AOI 1. PFBS was detected in groundwater collected from all three temporary 

wells associated with AOI 1; however, no concentrations exceeded their respective SLs. Due to 

depth to groundwater (17.40 to 21.05 ft bgs), it is unlikely that future construction workers will 

be exposed to PFAS through the groundwater via ingestion during trenching activities. Although

there is one potable well present at the Facility, the exposure pathway for site 

workers/trespassers and future construction workers via ingestion of groundwater is considered 

to be incomplete due to the existing potable well being located upgradient of the AOI and no 

relevant compounds were detected in SI groundwater samples collected from adjacent temporary 

monitoring wells. The exposure pathways for off-site residents and recreational users to 

groundwater are considered incomplete. The CSM is presented in Figure 7-1. 
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Notes:

1. No current active construction at the facility.

2. The resident and recreational users refer to off-site 

receptors.

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

insignificant. Figure 7-1

Conceptual Site Model

AOI 1

RECEPTOR

Human Receptors:

Current/Future

Site 

Worker/ 

Trespasser

Construction 

Worker1 Resident2,3 Recreational 

User2,3

Site 

Worker/ 

Trespasser

Construction 

Worker

Resident Recreational 

User

AOI 1

PFAS in 

Surface and 

Subsurface 

Soil, 

Groundwater

Human 

Activities

Precipitation/

Run-Off

Leaching/

Infiltration

Airborne 

Soil 

Particulate

Surface Soil 

at AOI

Surface 

Water/ 

Sediment

Subsurface 

Soil

Shallow 

Groundwater

Ingestion

Ingestion

Ingestion

Ingestion

Firetruck 

Storage 

Building (AFFF 

Storage Area)

SOURCE

Source Release 

Mechanism Media

PATHWAY

Transport

and Migration Media Exposure 

Routes

Inhalation 

of Dust

Potentially Complete Pathway with Exceedance of 

Screening Level

Potential 

Off-Facility 

Source Not 

under 

Control of 

ARNG
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8. SUMMARY AND OUTCOME

This section summarizes SI activities and findings. The most significant findings are summarized 

in this section and are reproduced directly or abstracted from information contained in this 

report. The outcome provides general and comparative interpretations of the findings relative to 

the SLs. 

8.1 SITE INSPECTION ACTIVITIES 

The SI field activities at the Facility were conducted on 9 December 2021. The SI field activities 

included 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 2021a), except as previously noted in Section 5.9. 

To fulfill the project DQOs set forth in the approved SI UFP-QAPP Addendum (EA 2021a), 

samples were collected and analyzed for a subset of 24 compounds by LC/MS/MS compliant 

with QSM Version 5.3 Table B-15 as follows:

• Twenty (20) soil samples from six boring and one hand augur locations;

• Six (6) grab groundwater samples from six temporary well locations; and

• Six (6) QA/QC samples.

An SI is conducted when the PA determines an AOI exists based on probable use, storage, and/or

disposal of PFAS-containing materials. The SI includes multi-media sampling at AOIs to 

determine whether or not a release has occurred. The SI may conclude further investigation is 

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

required. Additionally, the CSM was refined to assess whether a potentially complete pathway 

exists between the source and potential receptors for potential exposure at the AOI, which is 

described in Section 7. 

8.2 OUTCOME

Based on the results of this SI, further evaluation under CERCLA is not warranted for AOI 1

(see Table 8-1). Based on the CSM developed and revised based on the SI findings, 

concentrations of relevant compounds were below applicable SLs in soil and groundwater at 

AOI 1. Sample chemical analytical concentrations collected during this SI were compared 

against the project SLs for soil and groundwater, as described in Table 6-1.

A summary of the results of the SI data relative to the SLs is as follows:

• AOI 1:

 PFOS, PFOA, and PFBS were detected in groundwater near the source area (AOI 1). 

PFOS and PFOA were detected in one out of three temporary wells associated with 

the AOI, with concentrations of 0.69 ng/L and 1.5 ng/L, respectively, which do not 

exceed the associated SLs. PFBS was detected in all three temporary wells associated 

with the AOI, with a maximum concentration of 6.2 ng/L, which does not exceed the 
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associated SL. Based on the results of the SI, further evaluation at AOI 1 is not 

warranted.

 PFNA and PFOA were detected in surface and shallow subsurface soil at AOI 1 at 

concentrations below the SLs. PFNA was detected in surface soil at a maximum 

concentration of 1.3 μg/kg and PFOA was detected in surface soil at a maximum 

concentration of 1.8 μg/kg, which are considerably lower than the applicable SLs of 

19 μg/kg for each compound. Additionally, PFOA was detected in subsurface soil at a 

maximum concentration of 0.22 J μg/kg, which is three orders of magnitude below 

the applicable SL of 250 μg/kg. Based on the results of the SI, further evaluation at 

AOI 1 is not warranted.

• The Facility boundary:

 PFBS were detected in groundwater near the northern/downgradient facility 

boundary; however, PFBS did not exceed the SL in groundwater. None of the 

remaining relevant compounds (i.e., PFHxS, PFNA, PFOS, and PFOA) were detected 

in Facility boundary groundwater samples.

 None of the five relevant compounds (i.e., PFBS, PFHxS, PFNA, PFOS, and PFOA) 

were detected in soil samples taken from the facility boundary boring locations. 

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

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

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

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

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

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

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

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

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

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

AOI Potential Release Area

Soil

Source Area

Groundwater

Source Area

Groundwater

Facility Boundary Future Action

1 Firetruck Storage Building

No Further Action

Legend:

 = Detected; exceedance of screening levels.

 = Detected; no exceedance of screening levels.

 = Not detected.
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9. REFERENCES

AECOM Technical Services, Inc. (AECOM). 2020. Final Preliminary Assessment Report, 

Norfolk Facility Maintenance Shop #7, Nebraska September.

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

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

Department of the Army. 2016. EM-200-1-2, Environmental Quality, Technical Project 

Planning Process. 29 February.

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

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

. 2019b. General Data Validation Guidelines. November.

. 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). 2020a. Final Programmatic Uniform 

Federal Policy Quality Assurance Project Plan, Site Inspections for Per- and Polyfluoroalkyl 

Substances Impacted Sites, ARNG Installations, Nationwide. December.

———. 2020b. Final Programmatic Accident Prevention Plan, Revision 1. November.

. 2021a. Final Site Inspection Uniform Federal Policy Quality Assurance Project Plan 

(UFP-QAPP) Addendum, Norfolk Facility Maintenance Shop #7, Nebraska, Per- and 

Polyfluoroalkyl Substances Impacted Sites ARNG Installations, Nationwide. October.

———. 2021b. Final Site Safety and Health Plan, Norfolk Facility Maintenance Shop #7, 

Nebraska. March.

Guelfo, J.L. and C.P. Higgins. 2013. Subsurface transport potential of perfluoroalkyl acids and 

aqueous film-forming foam (AFFF)-impacted sites. Environ. Sci. Technol. 47(9):4164-71. 

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

Environ. Sci. Technol. 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 (EPA). 1980. Comprehensive Environmental Response,

Compensation, and Liability Act (CERCLA). 11 December.

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

40 Code of Federal Regulations Part 300; 59 Federal Register 47384. September.
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Norfolk Facility Maintenance Shop #7, Nebraska Version: FINAL

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

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

Assessments). December.

. 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.

U.S. Fish and Wildlife Service. 2022. Endangered Species. http://ecos.fws.gov/ipac/. Accessed 

on 18 March. 

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.