MANAGERS DESIGNERS/CONSULTANTS

®

Record of Decision for

Phase II Parcels 

Letterkenny Army Depot

U.S. Army Corps of Engineers

Baltimore District

July 2001

01P-0999a

LETTERKENNY

PENNSYLVANIA

CHAMBERSBURG,

ARMY DEPOT

BALTIMORE DISTRICT

Proud Past

 Dynamic Future

Final
Final

Record of Decision

for Phase II Parcels

Letterkenny Army Depot

Chambersburg, Pennsylvania

Delivery Order 0008

Contract Number DACA31-94D-0063

Prepared for

U.S. Army Corps of Engineers

Baltimore District

Baltimore, Maryland

Prepared by

ROY F. WESTON, INC.

1400 Weston Way

West Chester, Pennsylvania 19380-1499

July 2001

W.O. No. 02281.016.008
MK01|O:\02281016.008\PHASE II\ROD\ROD_FM.DOC FINAL ii

TABLE OF CONTENTS

SECTION PAGE

DECLARATION FOR THE RECORD OF DECISION.......................1

Site Name and Location............................................................................................... 1 

Statement of Basis and Purpose ................................................................................... 1 

DECISION SUMMARY........................................................................1

Section 1 Site Name, Location, and Description....................................................1 

 Information.............................................................................................. 1 

 Natural Resources................................................................................... 4 

 Phase II Parcels ....................................................................................... 4 

Section 2 Site History and Enforcement Activities ................................................7 

 History of Site Activities........................................................................ 7 

 Summary of Previous Site Investigations ............................................... 7 

 History of CERCLA Compliance Activities........................................... 8 

 Base Realignment and Closure (BRAC)................................................. 9 

Section 3 Community Participation Highlights....................................................10 

Section 4 Scope and Role of Response Action.....................................................10 

Section 5 Site Characteristics................................................................................10 

 Environmental Setting........................................................................... 10 

 Nature and Extent of Contamination .................................................... 12 

Section 6 Current and Potential Future Land and Resource Uses ........................14 

 Land Use ............................................................................................... 14 

 Groundwater Use .................................................................................. 15 

 Surface-Water Use ................................................................................ 15 

Section 7 Summary of Site Risks..........................................................................15 

 Summary of Human Health Risks ........................................................ 16 

 Soil ........................................................................................................ 17 

 Groundwater.......................................................................................... 20 

 Summary of Ecological Risks............................................................... 25 

 Uncertainty Analysis............................................................................. 25 
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TABLE OF CONTENTS

(Continued)

SECTION PAGE

Section 8 Remedial Action Objectives .................................................................25 

Section 9 Description of Alternatives...................................................................26 

 Alternative 1: No Action....................................................................... 27 

 Alternative 2: Institutional Controls ..................................................... 27 

Section 10 Summary of Comparative Analysis of Alternatives.............................28 

 Threshold Criteria ................................................................................. 28 

 Primary Balancing Criteria ................................................................... 29 

 Modifying Criteria ................................................................................ 30 

Section 11 Principal Threat Waste..........................................................................30 

Section 12 Selected Remedy...................................................................................31 

 Summary of the Rationale for the Selected Remedy............................ 31 

 Description of the Selected Remedy..................................................... 31 

 Summary of the Estimated Remedy Costs............................................ 32 

 Expected Outcomes of the Selected Remedy ....................................... 32 

 Performance Standards of the Selected Remedy.................................. 32 

Section 13 Statutory Limitations ............................................................................32 

 Protection of Human Health and the Environment ............................... 33 

 Compliance with Applicable or Relevant and Appropriate

 Requirements ........................................................................................ 33 

 Cost Effectiveness................................................................................. 33 

 Utilization of Permanent Solutions and Alternative Treatment 

 Technologies or Resource Recovery Technologies to the Maximum

 Extent Practicable ................................................................................. 33 

 Preference for Treatment as a Principal Element.................................. 33 

Section 14 Documentation of Significant Changes ................................................34 

GLOSSARY OF TERMS...................................................................G-1

RESPONSIVENESS SUMMARY.........................................................1
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TABLE OF CONTENTS

(Continued)

SECTION

ATTACHMENTS

ATTACHMENT 1 REFERENCES

ATTACHMENT 2 RISK ASSESSMENT TABLES

ATTACHMENT 3 GROUNDWATER LEVEL MONITORING PROGRAM TO 

SUPPORT TRANSFER OF PHASE II BRAC PARCELS AT 

THE LETTERKENNY ARMY DEPOT
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LIST OF FIGURES

TITLE PAGE

Figure 1 Property Location....................................................................................2 

Figure 2 Location of SE and PDO Areas, Enclave Areas,

Drainageways, and Drainage Divides at LEAD .....................................3 

Figure 3 Location of Phase II Parcels within PDO and SE Areas........................5 

Figure 4 Location of Phase II Road Parcels at LEAD...........................................6 

Figure 5 Conceptual Site Model for LEAD PDO Area Groundwater

Risk Assessment ...................................................................................21 

Figure 6 Conceptual Site Model for LEAD SE Area Groundwater

Risk Assessment ...................................................................................22 
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vi

LIST OF ACRONYMS

ARAR applicable or relevant and appropriate requirement

bgs below ground surface

BRAC Base Realignment and Closure 

CERCLA Comprehensive Environmental Response, Comp ensation, and Liability Act of 1980 

CFR Code of Federal Regulations

COC contaminant (chemical) of concern 

DCA 1,1-dichlorethane 

DCE 1,2-dichlorethene 

DSERTS Defense Site Environmental Restoration Tracking System

EPA U.S. Environmental Protection Agency

ft feet

LEAD Letterkenny Army Depot 

LIDA Letterkenny Industrial Development Authority

μg/L micrograms per liter

mg/kg milligrams per kilogram 

NCP National Oil and Hazardous Substances Pollution Contingency Plan 

NPL National Priorities List 

OSWER Office of Solid Waste and Emergency Response 

OU Operable Unit

PADEP Pennsylvania Department of Environmental Protection 

PCB polychlorinated biphenyl 

PDO Property Disposal Office 

QA/QC quality assurance/quality control

ROD Record of Decision 

SARA Superfund Amendments and Reauthorization Act of 1986 

SE Southeastern

SVOC semivolatile organic compound

VOC volatile organic compound

WESTON® Roy F. Weston, Inc.
MK01|O:\02281016.008\PHASE II\ROD\ROD_DECLARATION MAY 30.DOC FINAL 1 

LETTERKENNY ARMY DEPOT 

PHASE II PARCELS 

CHAMBERSBURG, FRANKLIN COUNTY, PENNSYLVANIA 

DECLARATION FOR THE RECORD OF DECISION 

JULY 2001 

SITE NAME AND LOCATION 

Phase II BRAC Parcels 

Letterkenny Army Depot 

Chambersburg, Franklin County, Pennsylvania

STATEMENT OF BASIS AND PURPOSE 

The Base Realignment and Closure Act of 1988 (Public 

Law 100-526, 102 Statute 2623) (BRAC 88) and the Defense 

Base Realignment and Closure Act of 1990 (Public Law 

101-510, 104 Statute 1808) (BRAC 91, 93, 95) designated 

more than 100 Department of the Army facilities for 

closure and/or realignment. In 1995, the United States 

Secretary of Defense (“1995 BRAC Commission”) 

submitted a recommendation to Congress that 

Letterkenny Army Depot (LEAD) in Chambersburg, 

Pennsylvania, be selected for realignment. As a result of 

the recommendations of the 1995 BRAC Commission, the 

U.S. Department of the Army (Army) must realign (i.e., 

change) the mission at LEAD. As part of the realignment, 

approximately 1,465 acres at LEAD have been designated 

for release (i.e., to-be-excessed or transfer of ownership). 

The Army’s strategy has been to first identify parcels with 

little or no environmental contamination and prepare 

them for transfer to a local redevelopment authority 

known as the Letterkenny Industrial Development 

Authority (LIDA). Before each property transfer, the 

Army, in consultation with the U.S. Environmental 

Protection Agency (EPA) and the Commonwealth of 

Pennsylvania, investigates the property for hazardous 

substances that may have been stored, disposed of, or 

released there. If necessary, the Army and EPA, in 

consultation with Pennsylvania, select a remedy designed 

to protect human health and the environment. 

The first set of parcels that the Army identified were the 

“Phase I parcels,” which were transferred to LIDA in 

1998. 

This Record of Decision (also referred to as the “ROD”) 

presents the selected remedy for the second set of parcels, 

the “Phase II parcels,” which consist of 51 parcels 

covering a total of approximately 374 acres. 

The groundwater beneath the Phase II parcels is known to 

be or potentially is contaminated with volatile organic 

compounds (VOCs). To expedite transfer, the Army and 

LIDA have defined the Phase II parcels to exclude the 

groundwater. The Phase II parcels are defined to include 

only the surface structures and soil to a depth of 8 feet 

below ground surface (ft bgs), which is above the seasonal 

high groundwater table. 

The remedy presented in this ROD was selected in 

accordance with the Comprehensive Environmental 

Response, Compensation, and Liability Act of 1980 

(CERCLA), as amended by the Superfund Amendments 

and Reauthorization Act of 1986 (SARA), and, to the 

extent practicable, the National Oil and Hazardous 

Substances Contingency Plan (NCP). This decision is 

based on the Administrative Record for this site. 

This document is issued by the Army, the owner of the 

property and the lead agency under CERCLA, and EPA. 

The Pennsylvania Department of Environmental 

Protection (PADEP) (on behalf of the Commonwealth of 

Pennsylvania) concurs with the selected remedy. 

Assessment of the Site 

VOCs have been released into the groundwater beneath 

LEAD, including the Phase II parcels. In addition, 

hazardous substances have been released into the soil at 

an area near the Gate 1 Guardhouse (Building 511) and at 

a few areas referred to as the “former PCB transformer 

sites” (“PCB”refers to a group of chemicals called 

polychlorinated biphenyls). 

The Army and EPA, in consultation with PADEP, have 

determined that no action is necessary to protect public 

health or welfare or the environment from the soil at the 

Phase II parcels, with the exception of soil in an area near 

the Gate 1 Guardhouse, Building 511. 

The remedy selected in this ROD is necessary to protect 

public health or welfare, or the environment from actual 

or threatened releases of hazardous substances into the 

environment. 

Description of the Selected Remedy 

Remedies for contamination at the Phase II parcels and for 

the groundwater beneath the parcels are proceeding in 

several steps. The Army, EPA, and PADEP are currently 

developing alternatives for a final remedy for the 

groundwater contamination. In the meantime, this ROD 

selects an interim remedy, known as “institutional 

controls,” to protect human health from contamination in 

the groundwater while a final remedy is developed. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—DECLARATION FOR THE ROD

MK01|O:\02281016.008\PHASE II\ROD\ROD_DECLARATION MAY 30.DOC FINAL 

2 

At the majority of the Phase II parcels, the Army found no 

evidence of releases of hazardous substances into the soil. 

At the few areas where there was evidence of a release 

(the former PCB transformer sites), the concentrations of 

hazardous substances are so low that the property can be 

used for any purpose without unacceptable risk to human 

health or the environment, with one exception. The 

exception is an area near the Gate 1 Guardhouse, Building 

511. This area may be used for commercial/industrial use 

without unacceptable risk to human health. However, use 

of this area for less restrictive uses, such as residential 

purposes, may pose unacceptable health risks. Therefore, 

EPA and the Army are selecting institutional controls for 

the area near the Gate 1 Guardhouse to prevent uses less 

restrictive than industrial/commercial (such as residential 

use). This is the final remedy for this area. 

For CERCLA administrative purposes the areas where 

there are known or suspected releases of hazardous 

substances at LEAD are being evaluated in groups of 

areas, or groups of type of media (such as groundwater), 

referred to as “operable units” (OUs). Portions of the 

Phase II parcels are a subset of soil OU 8, also referred to 

as SE OU 8, which is located in the part of LEAD referred 

to as the “Southeastern Area” (“SE Area”). There are three 

groundwater OUs located below the BRAC Phase II 

parcels: one in the part of LEAD referred to as the 

“Property Disposal Office Area” (“PDO Area”) (PDO OU 

2); and two in the SE Area (SE OU 3 and SE OU 10). These 

OUs are being addressed separately from the soil OUs 

and final response actions with regard to VOC 

groundwater contamination will be presented at a later 

time in the RODs for these OUs. 

There is no "principal threat waste" at the Phase II parcels, 

i.e., no waste source material that is highly toxic or highly 

mobile, and that generally cannot be reliably contained or 

would present a significant threat to human health or the 

environment should exposure occur. 

The institutional controls selected in this ROD consist of 

deed restrictions and environmental deed provisions for 

the Phase II parcels. The deed restrictions and the

environmental provisions will include the following 

restrictions: 

!"Restricting the Gate 1 Guardhouse (Building 511) area 

to commercial/industrial use (e.g., no residential or 

daycare use allowed). 

!"Prohibiting soil excavation, digging, drilling, or other 

soil-disturbing activities below a depth of 3 ft above 

the water table without the prior approval of the 

Army. The 3-ft layer of soil above the water table will 

be called the “3-ft buffer zone” in this document. 

!"Prohibiting access to or the use of the groundwater 

underlying the Phase II parcels without the prior 

approval of the Army, PADEP, and EPA. 

!"Prohibiting construction of any subsurface structure 

for human occupation without the prior approval of 

the Army, PADEP, and EPA. 

In addition, LIDA’s final reuse plan calls for 

industrial/commercial use for the majority of the Phase II 

parcels, and zoning restrictions imposed by Greene 

Township (in which most of the Phase II parcels lie) 

preclude residential use of land in that township. The 

specific deed restrictions will be coordinated with the 

regulators and the public as part of a “Finding of 

Suitability to Transfer” the Phase II parcels. 

An agreement among the Army, EPA, and PADEP to 

implement and maintain the institutional controls will be 

contained in a “Land Use Control Assurance Plan,” which 

will be executed prior to transfer of the Phase II parcels. 

The site-specific plan to implement and maintain the 

institutional controls will be contained in the “Land Use 

Control Implementation Plan,” which will be prepared as 

an attachment to the Land Use Control Assurance Plan. 

Statutory Determinations 

The Army and EPA, in consultation with PADEP, have 

determined that no action is necessary to protect public 

health or welfare, or the environment from the soil at the 

Phase II parcels, with the exception of soil in an area near 

the Gate 1 Guardhouse, Building 511. 

The selected remedy for the soil near the Gate 1 

Guardhouse, Building 511, is protective of human health 

and the environment, complies with Federal and state 

requirements that are legally applicable or relevant and 

appropriate to the remedial action, is cost-effective, and 

utilizes permanent solutions and alternative treatment (or 

resource recovery) technology to the maximum extent 

practicable. This remedy does not meet the statutory 

preference for treatment as a principal element because 

EPA generally does not expect to use treatment 

technology where, as here, contamination in soil exists at 

low concentrations; the contamination is neither highly 

toxic nor highly mobile; and the risks to humans from the 

soil are within acceptable limits if the property is used for 

commercial/industrial purposes. 

The selected interim remedy for groundwater beneath the 

Phase II parcels is protective of human health and the 

environment in the short term and is intended to provide 

adequate protection until a final groundwater remedy is 

selected; waives those Federal and state requirements that 

are applicable or relevant and appropriate for this 

limited-scope action; and is cost-effective. Under 

CERCLA, this interim remedy need not comply with 

applicable or relevant and appropriate requirements 

(ARARs) of Federal and state environmental laws where, 

as here, the interim remedy is only part of a total remedial 

action that will attain such requirements when completed. 

See CERCLA Section 121(d)(4)(A). The final remedy for 

groundwater is expected to comply with ARARs of 

Federal and state environmental laws or justify a waiver 

of these requirements in accordance with CERCLA. 

The groundwater remedy is an interim solution only, and 

is not intended to utilize permanent solutions and 

alternative treatment (or resource recovery) technologies 
LEITERKENNYARMYDEPOT

to the maximum extent practicable for groundwater.

Because this action does not constitute the final remedy

for the groundwater beneath LEAD, the statutory

preference for remedies that employ treatment that

reduces toxicity, mobility, or volume as a principal

element will be addressed by the final response action.

Subsequent actions are planned to fully address the

threats posed by the groundwater contamination at

LEAD.

Because the selected remedy will result in hazardous

substances remaining on-site above levels that allow for

unlimited use and unrestricted closure, a statutory

review will be conducted within 5 years after

commencement of the remedial action to ensure that the

remedy continues to provide adequate protection of

human health and the environment. The 5-year review

will include an evaluation of the interim groundwater

remedy (institutional controls) to determine if deed

restrictions related to groundwater can be removed when

a final groundwater remedy is implemented. Because the

selected remedy includes an interim action for

groundwater, review of this site and remedy will be

ongoing as the Army, EPA, and PADEP continue to

develop remedial alternatives for groundwater.

ROD Certification Checklist

The following information is included in the Decision

Summary section of this ROD. Additional information can

be found in the Administrative Record file for LEAD.

• Chemicals of concern and their respective

concentrations: Section 5, Site Characteristics, page

10, and Section 7, Summary of Site Risks, page 15.

• Baseline risk represented by the chemicals of

concern: Section 7, Summary ofSite Risks, page 15.

• Cleanup levels established for chemicals of

concern and the basis for these levels: This is not

addressed because cleanup levels were not

established, no removal/treatment is necessary for

the soils, and groundwater actions are interim

measures.

• How source materials constituting principal

threats are addressed: This item is not addressed in

the ROD because none of the known source areas

for the VOC-contaminated groundwater are in the

Phase II parcels. The soils in the Phase II parcels do

not pose a principal threat according to EPA

guidelines. Although the groundwater beneath the

Phase II parcels is contaminated, addressing a final

remedy for groundwater contaminated with VOCs

above acceptable risk-based levels it is not within

the confines of this ROD and will be addressed by

the final groundwater response action.

• Current and reasonably anticipated future land use

assumptions and current and potential future

beneficial uses of groundwater used in the

baseline risk assessment and ROD: Section 6,

MK011O:102281018.OOlN'HASE IMOOIROO_OEClARATION MAY 3O.00c

PHASE II PARCELS-DECLARATION FOR THE ROD

Current and Potential Future Land and Resource Uses,

page 14.

• Potential land and groundwater use that will be

available at the site as a result of the selected

remedy: Section 12, Selected Remedy, page 31.

• Estimated capital, annual operation and

maintenance, and total present worth costs,

discount rate, and the number of years over which

the remedy cost estimates are projected: Section 9,

Description ofAlternatives, page 26.

• Key factor(s) that led to selecting the remedy (i.e.,

describe how the selected remedy provides the

best balance of tradeoffs with respect to the

balancing and modifying criteria, highlighting

criteria key to the decision): Section 10, Summary of

Comparative Analysis ofAlternatives, page 28.

Authorizing Signatures

~~~~ Colonel, U.S. Army

Commanding

Letterkenny Army Depot

f18 JUL 2001

Date

~<J:,.A~.- Abraham Ferdas

Director, Hazardous Sites Cleanup Division

EPA, Region III

FINAL
O:\02281016.008\PHASE II\ROD\ROD_MAY 30.DOC FINAL 1 

LETTERKENNY ARMY DEPOT 

PHASE II PARCELS 

CHAMBERSBURG, FRANKLIN COUNTY, PENNSYLVANIA 

DECISION SUMMARY 

JULY 2001 

SECTION 1

SITE NAME, LOCATION, 

AND DESCRIPTION 

INTRODUCTION 

Letterkenny Army Depot (LEAD) is located in 

south-central Pennsylvania in Franklin County, 5 

miles north of the Borough of Chambersburg (see 

Figure 1). The Depot covers 19,243 acres, most of

which is devoted to ammunition storage (16,614 

acres). There are two areas within LEAD that are 

listed on the National Priorities List (NPL). They are 

the Property Disposal Office (PDO) Area and the 

Southeastern (SE) Area. These two areas are 

separated by a major groundwater/surface-water 

drainage divide, as depicted in Figure 2. The 

industrial and maintenance areas, which are 

primarily located in the southeastern corner of 

LEAD, encompass approximately 2,500 acres and 

include warehousing, vehicle storage, 

administration, industrial/maintenance, recreational 

activities, and housing. The infrastructure of this 

area includes roads; permanent, semipermanent, 

and temporary structures; and utilities. 

Approximately 1,465 acres at LEAD have been 

designated for “realignment” under the Base 

Realignment and Closure (BRAC) initiative. 

“Realignment” means that the mission at LEAD is to 

change and approximately 1,465 acres at LEAD have 

been designated for release (i.e., “to-be-excessed” or 

transfer of ownership). The BRAC area is 

concentrated in the southeastern portion of LEAD, 

but is located in both the PDO and SE Areas. The 

BRAC area is being transferred to the Letterkenny 

Industrial Development Authority (LIDA) in phases. 

The Phase I parcels were transferred in 1998. The 

Phase II parcels are defined as follows: structures 

and property to a depth of 8 feet below the ground 

surface (ft bgs) (which is above the seasonal high 

groundwater table). The Phase II parcels consist of 

51 parcels located in both the PDO and SE Areas, 

and encompass approximately 374 acres designated 

by the U.S. Army and LIDA. 

What is BRAC? 

The Base Realignment and Closure Act of 1988 

(Public Law 100-526, 102 Statute 2623) (BRAC 88) 

and the Defense Base Realignment and Closure Act 

of 1990 (Public Law 101-510, 104 Statute 1808) 

(BRAC 91, 93, 95) designated more than 100 

Department of the Army facilities for closure and/or 

realignment. In 1995, the U.S. Secretary of Defense 

(“1995 BRAC Commission”) submitted a 

recommendation to Congress that Letterkenny Army 

Depot (LEAD) in Chambersburg, Pennsylvania, be 

selected for “realignment.” As a result of the 

recommendations of the 1995 BRAC Commission, 

the U.S. Department of the Army (Army) must realign 

(i.e., change) the mission at LEAD and transfer 

ownership of property referred to as the “BRAC 

parcels” or “BRAC area.” 

As part of the realignment of the LEAD mission, an 

environmental baseline survey was completed for the 

BRAC area. The environmental baseline survey 

process includes visual inspections of the property as 

well as record reviews and personnel interviews, 

which are used to document current and historical 

conditions with regard to use, storage, or release of 

hazardous substances and petroleum products. 

The environmental baseline survey process is used 

to identify areas within the BRAC parcels that need 

further investigation, normally referred to as site or 

remedial investigations. These are studies typically 

consisting of sampling and analysis (to see if 

chemicals are present) of soil, sediment, and/or 

groundwater and other techniques to identify 

releases to the environment and to provide data for 

evaluating potential risks to future users of the land. 

Also as part of the BRAC process, the Army prepares 

a “Finding of Suitability to Transfer” document that 

provides information to the U.S. Environmental 

Protection Agency (EPA), the Pennsylvania 

Department of Environmental Protection (PADEP), 

the public, and LIDA concerning the environmental 

condition of the buildings and land being transferred. 

The Finding of Suitability to Transfer also contains 

any specific deed restrictions related to 

environmental issues. 

This Record of Decision document, also referred to 

as a “ROD,” addresses soils in the Phase II parcels 

located in both the PDO and SE Areas, and 

addresses an interim action for groundwater 

beneath the Phase II parcels, because the 

groundwater beneath the Phase II parcels is known 
Property location shown in black. Base map image adapted

from the U.S. Geological Survey 30x60 minute quadrangle maps,

Carlisle, PA (photo inspected 1985) and Hagerstown, MD, PA, WV (1983).

Scale

1:100,000

0 4

0 Kilometers 5

Miles N

WV

MD

PENNSYLVANIA

98P-0629

Letterkenny Army Depot

Philadelphia

Pittsburgh Harrisburg

LETTERKENNY

ARMY DEPOT

U.S. Army Corps of Engineers

Baltimore District

Letterkenny Army Depot

Chambersburg, Pennsylvania

FIGURE 1

PROPERTY LOCATION

LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

O:\02281016.008\PHASE II\ROD\ROD_MAY 30.DOC FINAL 4 

to be or potentially is contaminated. The Army, EPA, 

and PADEP are currently developing alternatives for 

a final remedy for the contaminated groundwater 

beneath LEAD. After the groundwater remedy has 

been determined to be operating properly and 

successfully, the Army will transfer the subsurface 

Phase II parcels to LIDA. 

This ROD: (1) addresses and provides the rationale 

for the selected remedy for contaminated 

groundwater beneath the Phase II parcels; 

(2) addresses and provides the rationale for the 

selected remedy for soils at the Gate 1 Guardhouse, 

Building 511; and (3) addresses public comments 

concerning the selected remedy. The evaluation of 

the remedial alternatives for the soils at the Gate 1 

Guardhouse area is documented in the Feasibility 

Study Report for the Gate 1 Guardhouse, Building 511

(WESTON, 2001a). In addition, this ROD includes 

summaries of other cleanup alternatives evaluated 

for use at the Phase II parcels. 

The portion of the Phase II parcels referred to as the 

Gate 1 Guardhouse, Building 511 (part of Phase II, 

designated as Parcel 2R-80), is to be transferred to 

LIDA with deed restrictions to limit the future use of 

the parcel to commercial/industrial use. The future 

use of the Phase II parcels is currently planned as 

community use for Parcel 2-74, residential or 

community use for Parcel 2-75, and 

commercial/industrial use for the remaining parcels. 

The U.S. Army is the owner of the property and the 

lead agency under the Comprehensive 

Environmental Response, Compensation, and 

Liability Act (CERCLA). EPA and PADEP have roles 

as support agencies. The Army and EPA are issuing 

this ROD. PADEP, on behalf of the Commonwealth 

of Pennsylvania, concurs with the selected remedy. 

NATURAL RESOURCES 

The property included in the Phase II parcels 

consists of industrial land, developed land, small 

stands of trees, open grassy areas, agricultural areas, 

and roadways. No wetlands are located within the 

Phase II parcels, and no Federal or state threatened 

or endangered species are known or suspected to 

exist within the Phase II parcels. 

PHASE II PARCELS 

LIDA developed a list of priority buildings and 

parcels based on their potential for reuse and 

redevelopment. The Phase II parcels represent those 

buildings and properties identified by LIDA that the 

Army deems environmentally suitable for transfer at 

this time. This decision is documented in the Finding 

of Suitability to Transfer for the Phase II parcels 

(May 2001). 

A total of 51 parcels have been selected for the Phase 

II parcel transfer. The groundwater beneath all of the 

Phase II parcels is known to be or is potentially 

contaminated with volatile organic compounds 

(VOCs) and is being remediated separately. As a 

result of the groundwater VOC contamination, the 

Phase II parcels are limited to the property that 

includes buildings, structures, and soil from the 

ground surface down to a depth of 8 ft bgs, which is 

above the seasonal high groundwater table. Total 

VOC concentrations up to 60 micrograms per liter 

(μg/L) and 112 μg/L have been detected in 

groundwater in the PDO and SE Areas, respectively. 

The final groundwater remedial alternatives are 

being addressed separately as part of groundwater 

operable units (OUs) PDO OU 2, SE OU 3, and SE 

OU 10 (see “Glossary of Terms” for definition of 

“operable unit”). 

Of these parcels, 37 are located in the SE Area, 5 

parcels are located in the PDO Area, and 9 parcels 

are located on roadways within both the PDO and 

SE Areas. The locations of these parcels in the PDO 

and SE Areas are depicted in Figure 3. The roadway 

parcels are shown in Figure 4.

The identification codes of the parcels are as follows: 

Parcels within the SE Area: 

!" Parcel 2-35 

!" Parcel 2-36 

!" Parcel 2-37 

!" Parcel 2-38 

!" Parcel 2-39 

!" Parcel 2-40 

!" Parcel 2-41 

!" Parcel 2-42 

!" Parcel 2-43 

!" Parcel 2-44 

!" Parcel 2-45 

!" Parcel 2-46 

!" Parcel 2-47 

!" Parcel 2-48 

!" Parcel 2-49 

!" Parcel 2-50 

!" Parcel 2-51 

!" Parcel 2-52 

!" Parcel 2-53 

!" Parcel 2-54 

!" Parcel 2-55 

!" Parcel 2-56 

!" Parcel 2-57 

t

u. s. """" Carp. of Eng'n.....

Ba.1'tIPKJ,.. Dlrirlct

Feet

Township Line

o 900

----

Figure 4

Location of Phase II

Road Parcels at LEAD

Buildings

Enclave Area

_ _ Dashed portions of the

road parcels are located in

the Enclave area and will not

be transferred. Public access to

these roads 1rill be permitted.

_ Road Parcel

Letterkenny Army Depot

Chambersburg, PA

- I _ Drainage Divide

2R-86 = Phase II Parcel In

Oregon(Opportunity) = LEAD Road Name

(IJDA Designated Road Name)

Legend:

Building 301

GATE 6

/TECHNOLOGY)

~~~.Ijb:::::::::=~:d'Building 245

GATE 5

2R-84 TEXAS/WASHINGTON (INNOVATION)

~. 511 ".

Letterkenny Township Roads

FSlrC6 q:\letter\army\BRAC-I'oadsJU4.dW', OS/23/01
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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!" Parcel 2-58 

!" Parcel 2-59 

!" Parcel 2-60 

!" Parcel 2-61 

!" Parcel 2-62 

!" Parcel 2-63 

!" Parcel 2-64 

!" Parcel 2-65 

!" Parcel 2-66 

!" Parcel 2-67 

!" Parcel 2-68 

!" Parcel 2-69 

!" Parcel 2-70 

!" Parcel 2-77 

Parcels within the PDO Area: 

!" Parcel 2-71 

!" Parcel 2-72 

!" Parcel 2-74 

!" Parcel 2-75 

!" Parcel 2-76 

Parcels on Roadways: 

!" Parcel 2R-80 

!" Parcel 2R-81 

!" Parcel 2R-82 

!" Parcel 2R-83 

!" Parcel 2R-84 

!" Parcel 2R-85 

!" Parcel 2R-86 

!" Parcel 2R-87 

!" Parcel 2R-88 

SECTION 2

SITE HISTORY AND 

ENFORCEMENT ACTIVITIES 

HISTORY OF SITE ACTIVITIES 

Prior to the establishment of LEAD in 1942, the area 

consisted of agricultural and forest lands. The area 

was predominantly single-family farms used for 

both subsistence and commercial purposes. 

The Letterkenny Ordnance Depot was established in 

January 1942 as an ammunition storage facility. In 

subsequent years, the following missions were 

added: 

!" Reserve storage and export advance storage of 

parts, tools, supplies, and equipment for combat 

vehicles, artillery, small munitions, and vehicle 

fire control equipment (1943). 

!" Receipt and storage of hardware, heavy-duty 

trucks, and parts (1944). 

!" Establishment of transport and combat vehicle 

shops and expansion of the maintenance 

program (1947). 

!" Establishment of a rebuild system for guided 

missile ground control, launching, and handling 

equipment; missile propellant systems; and 

internal guidance systems (1954). 

!" Assignment of the special weapons mission 

(1958). 

!" Designation of the Depot as the Eastern 

Equipment Assembly Area (1959). This mission 

gave the Depot responsibility for the handling 

and shipment of equipment for guided missile 

and special weapons units to overseas locations. 

!" Acceptance and destruction of contaminated 

U.S. Air Force missile fuel (1961).

!" Letterkenny Ordnance Depot renamed as 

Letterkenny Army Depot (1962). 

!" Disposal of explosive ordnance generated from 

the Army as well as state and local police (1964). 

!" Maintenance and storage of U.S. Air Force 

missiles (1966). 

!" Receipt, storage, and dispersal of batteries and 

tires to Army units (1972). 

!" Operation of a washout facility to reclaim 

explosives from munitions (1973). 

These operations consisted of cleaning, stripping, 

painting, lubrication, and plating activities, which 

involved the use of solvents, blast media (such as 

sand from sandblasting operations), paints, 

chemicals, petroleum products, and metals. Storage, 

spills, releases, and disposal of these materials led to 

the current environmental concerns at LEAD. 

SUMMARY OF PREVIOUS SITE 

INVESTIGATIONS 

Studies initiated since 1979 have concluded that 

toxic materials associated with operations at LEAD, 

along with uncertain past disposal practices and the 

nature of the hydrogeological regime, offered 

significant potential for contamination by 

chlorinated hydrocarbons and subsequent 

contaminant migration. Between 1980 and the 

present, numerous environmental investigation 

programs were conducted at LEAD to evaluate 

potential contamination in the soil and groundwater 

at the Depot. In 1986, EPA ranked the LEAD SE 

Area (including the Disposal Area and the Southeast 

Industrial Area) and the PDO Area under the 

Uncontrolled Hazardous Waste Site Ranking 

System, and proposed these two areas for inclusion 

on the NPL. The SE Area was placed on the NPL in 
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July 1987. The PDO Area was added to the NPL list 

in March 1989. Investigations and remedial actions 

are currently underway at both NPL sites. 

Previous investigations specific to the Phase II 

parcels are discussed in Section 5 and under the 

BRAC paragraph in this section. 

HISTORY OF CERCLA COMPLIANCE 

ACTIVITIES 

Since the listing of the two NPL sites at LEAD, all of 

the remedial activities at the site have been Armyled, in coordination with EPA Region III and PADEP 

South-central Region. No other potentially 

responsible parties have been identified. 

As a result of the proposed NPL ranking, the U.S. 

Army Toxic and Hazardous Materials Agency, later 

renamed the U.S. Army Environmental Center, took 

the initiative in conducting the response actions at 

LEAD in accordance with Executive Order 12316 

and a Memorandum of Understanding of 12 August 

1983. The Executive Order was signed on 14 August 

1981 by President Reagan. It delegates to the 

Secretary of Defense the authority to take the lead on 

CERCLA activities at Federal facilities. The 

Memorandum of Understanding is between EPA 

and the U.S. Department of Defense. It defines the 

relationship for Federal facilities to take the lead on 

such activities with EPA input. 

Executive Order 12580 was signed in January 1987, 

which superseded Executive Order 12316. This 

Executive Order transferred authority for site 

investigations and remedial actions at Federal 

facilities to the secretaries of the applicable Federal 

agencies. 

On 3 February 1989, a Federal Facilities Agreement 

was reached under CERCLA Section 120 among the 

U.S. Department of Defense, EPA, and PADEP 

(EPA, Army, and PADEP, 1989). 

The 1989 Federal Facilities Agreement established 

the framework for the CERCLA response actions at 

LEAD and required the review of all documents 

concerning the investigation of environmental 

contamination at LEAD produced prior to the 

Federal Facilities Agreement. 

The PDO Area encompasses approximately 1,490 

acres in the southern portion of the Depot. It extends 

approximately south from the southern end of the 

combat vehicle test track southwest to Rocky Spring 

Lake. The groundwater in the PDO Area becomes 

surface-water discharge at Rocky Spring, which 

flows into the Rocky Spring Branch of the 

Conococheague Creek, and eventually into the 

Potomac River. Six OUs exist within the PDO Area. 

The following is a description of each OU in the 

PDO Area: 

!" OU 1: Source Area Soils (soil from the oil burn 

pit and drum storage revetments). 

!" OU 2: PDO Area Groundwater and Surface 

Water. 

!" OU 3: Mercury Detections in Rocky Spring Lake. 

!" OU 4: Groundwater Associated with the Oil 

Burn Pit. 

!" OU 5: Polychlorinated Biphenyl (PCB) 

Investigation of the Rocky Spring System. 

!" OU 6: BRAC Waste Sites. 

The response action in this ROD concerns areas in 

PDO OU 2 (groundwater below the parcels) and 

PDO OU 6. OU 2 was originally established when 

the Federal Facilities Agreement was signed. OU 4 

was created in December 1992 based on the results 

of the 1993 Final PDO OU 1 and OU 2 Remedial 

Investigation Report. The creation of OU 4 allowed 

for the continued remedial response at OU 2, while 

additional investigations were conducted at OU 4. 

OU 6 is comprised of waste sites, located in the tobe-excessed (BRAC) part of the PDO Area, that were 

identified as part of the environmental baseline 

survey process. 

A draft ROD was completed for OU 2 that identified 

a response action for groundwater based on the 

LEAD property line as the surface-water point of 

compliance. PADEP concluded that the point of 

compliance is at the springhouse discharge, where 

water with VOCs exceeds surface-water criteria. 

Therefore, the response action for groundwater is 

currently being re-evaluated. 

Investigations are continuing and long-term 

sampling has commenced at OU 2 (to support a 

future final ROD). Investigations, risk assessments, 

and feasibility studies are currently being conducted 

for OU 6 (see the “Glossary of Terms” for definitions 

of remedial investigation, risk assessment, and 

feasibility study). 

The SE Area consists of the Southeast Industrial 

Area and the Disposal Area, and encompasses 

approximately 1,136 acres. A total of 10 OUs exist 

within the SE Area. The following is a description of 

each OU in the SE Area: 

!" OU 1: K Area Contaminated Soils. 

!" OU 2: Industrial Wastewater Sewers and 

Contaminated Soils. 
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!" OU 3: VOC-Contaminated Groundwater North 

of Gate 6. 

!" OU 4: Stormwater Sewers and Contaminated 

Sediments. 

!" OU 5: Areas A and B Contaminated Soils. 

!" OU 6: SE Area Off-Post Groundwater. 

!" OU 7: Truck Open Storage Area/Waste Oil 

Sump. 

!" OU 8: BRAC Waste Sites (including the former 

PCB transformer sites and the Gate 1 

Guardhouse, Building 511). 

!" OU 9: Landfill J; near Building 320. 

!" OU 10: Southern Southeast Industrial Area 

VOC-Contaminated Groundwater South of Gate 

6. 

The response action in this ROD concerns areas in SE 

OU 3 and SE OU 10 (groundwater below the 

parcels), and SE OU 8 (Phase II parcels). 

Site/remedial investigations, risk assessments, and 

feasibility studies are currently being conducted at 

SE OU 8; investigations and risk assessments have 

been completed for some portions of SE OU 8. 

Investigations associated with on-post VOCimpacted groundwater have been conducted for 

BRAC sites in SE OU 8 under SE OU 3 and SE OU 

10. Both SE OU 3 and SE OU 10 are currently in the 

focused feasibility study stage (see the “Glossary of 

Terms” for a definition of focused feasibility study). 

Six groundwater pilot studies have been completed. 

An extended groundwater pilot study is currently 

ongoing for SE OU 10. 

BASE REALIGNMENT AND CLOSURE 

(BRAC) 

The majority of the administrative, industrial, and 

housing facilities at LEAD have been designated for 

“release” (“to-be-excessed” or transfer of ownership 

of property) from the U.S. Army based on the 

decision of the 1995 BRAC Commission to realign 

the LEAD mission. The land designated for release 

will be transferred to LIDA in a manner that follows 

BRAC program guidance. 

The Ammunition Area (Ammo Area), and selected 

portions of the industrial/administrative area, will be 

retained to support LEAD’s continuing mission. The 

retained area is also known as the “Enclave Area.” 

The LEAD BRAC Cleanup Team was established in 

1995 to facilitate the environmental issues involved 

with the realignment at LEAD. The BRAC Cleanup 

Team is composed of the LEAD BRAC Environmental 

Coordinator and the Remedial Project Managers from 

EPA Region III and PADEP. The BRAC Cleanup 

Team meets on a monthly basis to discuss 

environmental issues related to the transfer of 

property at LEAD. The goal of the BRAC Cleanup 

Team is to streamline decisions, and to work together 

toward innovative and timely techniques to facilitate 

the timely transfer of property. 

As part of the realignment of the LEAD mission, an 

environmental baseline survey was completed for 

the BRAC parcels. The environmental baseline 

survey process includes visual inspections of the 

property as well as record reviews and personnel 

interviews, which are used to document current and 

historical conditions with regard to use, storage, or 

release of hazardous substances and petroleum 

products. The LEAD environmental baseline survey 

was finalized in August 1996 (WESTON, 1996). The 

final Community Environmental Response 

Facilitation Act letter report, which contains a map 

showing the environmental conditions at LEAD, was 

finalized in March 1997. An addendum to the 

environmental baseline survey, which updated 

environmental conditions, was finalized in April 

1999 (WESTON, 1999a). A follow-up document, 

Supplement 1 to the environmental baseline survey, 

was finalized in November 2000 (WESTON, 2000a). 

This document included several buildings not 

covered in the environmental baseline survey or the 

addendum. None of the parcels and buildings 

covered under this ROD were identified as having 

any environmental concerns, aside from the Gate 1 

Guardhouse and the documented VOC groundwater 

contamination. None of the Phase II parcels 

contribute to the documented VOC groundwater 

contamination in the PDO and SE Areas. Of the 

Phase II parcels, only those areas that contain or 

formerly contained transformers that contained 

PCBs in the past (parts of Parcels 2-36, 2-38, 2-45, 

2-50, and 2-55) and the Gate 1 Guardhouse, Building 

511 (part of Parcel 2R-80), were identified as needing 

further study. 

Site investigations, remedial investigations, and 

screening level risk assessments have been 

completed for the Phase II parcels. Site 

investigations, remedial investigations, and 

screening level risk assessments have been 

completed or are currently underway for other 

BRAC parcels that have not yet been transferred. A 

CERCLA site investigation and risk screening was 

performed on the Phase II parcels to determine if the 

sites could be cleared for transfer and reuse 

pursuant to the BRAC program. 

The future use of the Phase II parcels is currently 

planned as community use for Parcel 2-74, 

residential or community use for Parcel 2-75, and 
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commercial/industrial use for the remaining parcels. 

The portion of the Phase II parcels referred to as the 

Gate 1 Guardhouse, Building 511 (part of Parcel 

2R-80), is to be transferred to LIDA with deed 

restrictions to limit the future use of the parcel to 

commercial/industrial use. LIDA’s final reuse plan 

(as referenced by the Memorandum of Agreement 

between the Army and LIDA) specifies the intended 

future use of the parcels. In addition, zoning 

restrictions imposed by Greene Township preclude 

residential use of the BRAC parcels in that township. 

SECTION 3

COMMUNITY PARTICIPATION 

HIGHLIGHTS 

Pursuant to CERCLA Section 113(k)(2)(B)(i-v) and 

Section 117, the Proposed Plan for the Phase II 

parcels at LEAD was released to the public for 

comment on 20 February 2001. This document was 

made available to the public, in the Administrative 

Record, located in Building 618 at LEAD, and in the 

Coyle Free Library in Chambersburg. 

The notification of the Proposed Plan public meeting 

was published in The News Chronicle, The Record 

Herald, and The Public Opinion on 16 February 2001. 

A public comment period was held from 20 

February 2001 to 22 March 2001. On 22 February 

2001, a public availability session was held at the 

Building 10 Letterkenny Great Room to present the 

Proposed Plan (in the form of a poster presentation) 

and to entertain questions and comments from the 

public. A summary of the community participation 

process is provided in the Responsiveness Summary, 

which is included as part of this ROD. There were no 

comments received during the public comment 

period, and there were no comments or questions 

during the public availability session. 

SECTION 4 

SCOPE AND ROLE OF 

RESPONSE ACTION 

The response action selected for the Phase II parcels 

is a final action with regard to soils at the Gate 1 

Guardhouse, and an interim measure with regard to 

VOC-contaminated groundwater, which together 

address the environmental concerns at the Phase II 

parcels. This response action is limited to the Phase 

II parcels, and is NOT intended as a final measure to 

address the VOC-contaminated groundwater OUs 

(PDO OU 2, SE OU 3, and SE OU 10). Final remedial 

actions for these OUs are being developed 

separately. A draft ROD was prepared for PDO OU 

2; further investigations are continuing at PDO OU 

2. SE OU 3 and SE OU 10 are in the focused 

feasibility study stage. 

The environmental threat posed by the conditions at 

the Phase II parcels is the potential exposure to 

contaminated groundwater and the potential 

exposure to soils at the Gate 1 Guardhouse area 

(Parcel R-80), should the property be used for 

nonindustrial (e.g., residential) purposes. 

Implementation and enforcement of the selected 

remedy (institutional controls) will mitigate the 

potential for exposure and will facilitate the reuse of 

the property.

The role of the response action selected for the Phase 

II parcels is to mitigate environmental threats at the 

properties while making the parcels available for 

beneficial reuse in a timely manner. 

SECTION 5 

SITE CHARACTERISTICS 

The following information is presented to document 

the site characteristics of the Phase II BRAC parcels. 

Some of the environmental setting information is 

general to all of LEAD, with specific references to 

the Phase II parcels as appropriate. The Phase II 

parcels consist of approximately 374 acres. There are 

no wetlands or other ecologically sensitive areas 

located in the Phase II parcels. In addition, there are 

no areas of significant historical or archaeological 

importance in the Phase II parcels. The information 

pertaining to the site conceptual model and the 

nature and extent of contamination is presented 

following the environmental setting discussion. 

ENVIRONMENTAL SETTING 

Topography and Surface Drainage 

LEAD is located in the Great Valley section of the 

Valley and Ridge Province of the eastern United 

States, and is referred to locally as the Cumberland 

Valley. The Cumberland Valley trends northeast to 

southwest through central Pennsylvania and is 

bordered to the west by the Appalachian Mountain 

Province. The South Mountain section of the Blue 

Ridge Province is situated east of Chambersburg 

and marks the eastern edge of the Cumberland 

Valley. 

The Cumberland Valley is characterized by 

southwest-trending limestone ridges and valleys. 

The valley floors are filled with rocks of the 
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Martinsburg Formation. Weathering of the folded 

and faulted underlying geological formations 

imparts a gently rolling aspect to the local 

topography. The majority of LEAD is located within 

the Martinsburg Shale terrain, except for bands of 

carbonate rocks along the eastern and western edges 

of LEAD. The PDO Area and the Southeast 

Industrial Area of LEAD are underlain by limestone. 

Figure 2 shows the general locations of the PDO and 

SE Areas. Surface elevations throughout LEAD 

range from approximately 600 to 750 ft above mean 

sea level, except for the northwestern portion of 

LEAD, where the elevation increases abruptly to 

more than 2,300 ft above mean sea level in the 

vicinity of Broad Mountain (EA, 1991). 

Streams cutting through the limestone terrain flow 

through broad, open valleys and are usually 

intermittent. In contrast to this, streams cutting 

through the upper shale units of the Martinsburg 

Formation usually meander in small, steep-walled 

valleys and are perennial. Surface drainage at LEAD 

is divided into two watersheds—the Susquehanna 

River to the northeast and the Potomac River to the 

southwest. Both the Susquehanna and Potomac 

Rivers eventually drain into the Chesapeake Bay. 

Surface water from the Phase II parcels located in 

the PDO Area flows to drainage ditches, and then 

ultimately flows to the Potomac River watershed via 

the Rocky Spring Branch system. 

Two major stormwater drainage systems serve the 

southeastern portion of LEAD and contribute to 

local surface drainage. One system serves the area 

north of Coffey Avenue and discharges near the 

industrial wastewater treatment plant into the 

discharge ditch (located north of the industrial 

wastewater treatment plant), which discharges to 

Rowe Run; no Phase II parcels drain to this system. 

The other stormwater system serves the 

southeastern warehouse area (where the SE Area 

Phase II parcels are located). Stormwater is 

discharged at the stormwater outfall into the 

southeastern drainageway, which discharges to the 

Conococheague Creek. Figure 3 illustrates the major 

drainage divides at LEAD. 

Geology 

LEAD straddles two major structural features—the 

South Mountain anticlinorium to the east and the 

Massanutten synclinorium to the west. The eastern 

portion of the Depot (underlain by carbonate rocks) 

is part of the anticlinorium, whereas the western 

portion of the Depot (underlain by shale) is part of 

the synclinorium. These structures resulted from 

folding that occurred during the close of the 

Paleozoic era. High-angle reverse faulting 

accompanied the folding of rocks in the eastern 

portion of LEAD. Several major faults, which strike 

north to northeast and dip to the southeast at fairly 

steep angles, cross the PDO Area (WESTON, 1984). 

In the vicinity of LEAD, the Great Valley is floored 

by Ordovician age carbonate rock, as well as 

Ordovician age shale and greywacke of the 

Martinsburg Formation. The five formations 

occurring at LEAD are the shales of the Martinsburg 

Formation, the limestones of the Chambersburg 

Formation and the St. Paul Group, the limestones 

and dolomites of the Rockdale Run Formation, and 

the dolomites of the Pinesburg Station Formation. 

These geological formations are fractured and 

deformed to varying degrees from past geological 

activity (ESE, 1993a). 

Two major faults, the Pinola fault and the 

Letterkenny fault, and several other unnamed faults, 

extend through the LEAD site boundary. Although 

an east-to-west cross fault was identified between 

these two faults, both the position and surface trace 

are open to question (Becher and Taylor, 1982). 

The Letterkenny fault is one of the few faults in the 

region that parallels the tectonic grain, yet is an early 

formed, eastward-dipping, thrust that moved 

material from within the syncline up onto the 

anticline to the west (EA, 1991). 

The Pinola fault, located west of the Letterkenny 

fault, is considered to be an east-dipping, highangle, thrust fault (because older beds are located 

east of the fault). Because it is almost impossible to 

trace faults through the Martinsburg terrain, the 

fault trace is projected through the Martinsburg 

Formation on the basis of a ridge-forming unit that 

extends through it (Becher and Taylor, 1982). 

Hydrogeology 

The regional surface-water flow system of Franklin 

County controls the general groundwater flow 

patterns within LEAD. The surface-water drainage 

divide, discussed previously, also divides the 

groundwater flow system into two basins. 

Groundwater elevation contours within LEAD 

generally reflect surface topography. The water table 

is located at moderate depth in areas of topographic 

highs, and is shallow near stream valleys and other 

topographic lows (ERM, 1995). 

The shale and carbonate rock that underlie LEAD 

have been disturbed and faulted during 

deformational events that ultimately formed the 

Great Valley. The two major faults located within the 

confines of LEAD (the Pinola fault and the 
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Letterkenny fault) influence groundwater flow. 

Where faulting is present and dissimilar rocks have 

been brought into contact, the fault tends to act as a 

barrier to groundwater movement, occasionally in 

low-lying areas forcing water within the formation 

to discharge as a fault spring. Where similar rocks 

are in contact along a fault (i.e., two limestone units), 

the groundwater movement may be only minimally 

affected (ERM, 1995). 

Fracture systems within the Martinsburg Formation 

are generally small but are numerous and well 

connected, thus allowing groundwater to generally 

follow a regional flow path. Groundwater flow 

within the limestone of the Chambersburg 

Formation and St. Paul Group is more complex 

because it occurs predominantly through more 

isolated fractures and solution cavities typical of 

karst terrain. Fractures in the limestones are mostly 

aligned with the regional northeast tectonic grain 

and are much more irregular and widely spaced 

than those in the adjacent shales. Where solution 

cavities are present in the limestone, groundwater 

flow more closely resembles open channel flow 

rather than the fracture flow described previously. 

The quantity and density of fractures and solution 

cavities within the limestone units are generally 

greatest in the upper 150 ft and generally decrease 

with depth. During three-quarters of the year (high 

and base flow conditions) groundwater levels are 

above the soil-bedrock interface. 

Leaching or resuspension of any materials or 

potential contaminants buried in the overburden 

soils may be enhanced during high water table 

conditions (ERM, 1995). 

Groundwater “recharge” occurs primarily through 

precipitation. “Recharge” refers to replenishing of 

supplies of groundwater. Recharge areas occur 

throughout the central part of LEAD, wherever 

fractured and jointed sandstone, siltstone, and shale 

bedrock are close to the surface. Actual points of 

recharge for the limestone aquifers have not been 

determined; however, the most likely routes are the 

many faults, joints, and sinkholes present at LEAD 

(ERM, 1995). 

Groundwater underlying LEAD generally occurs 

under unconfined conditions, with local areas of 

artesian conditions. These artesian conditions occur 

along a moderately steep slope located near the 

northwestern edge of LEAD in the Ammunition 

Area. 

Soils 

Surface soils present at LEAD are predominantly 

shaley to very shaley silt loams that developed 

through weathering of the Martinsburg Shale and 

the interbedded siltstones and sandstones. 

According to the Soils Survey Bulletin of Franklin 

County, these soils have been classified as part of the 

Weikert-Berks-Bedington Association. Soils on the 

eastern edge of LEAD associated with the limestone 

have been identified as part of the HagerstownDuffield Association. These soils are deep, level or 

sloping, somewhat poorly drained, and mostly 

rocky, silty, clay loams. Along the western side of 

LEAD, outside the BRAC area, are soils of both the 

Laidig-Very stony land-Buchanan Association 

(formed from sandstone) and the Morrill-Laidig 

Association (formed on the foot of mountain slopes). 

NATURE AND EXTENT OF CONTAMINATION 

Soil 

Numerous studies have been conducted in both the 

PDO and SE Areas at LEAD. These studies 

identified several areas of soil contamination. None 

of the identified soil contamination areas that 

require action lie within the Phase II parcels. Based 

on the environmental baseline survey, several of the 

Phase II parcel areas underwent limited 

investigations of the soils to rule out the potential for 

soil contamination due to past operations. The 

remainder of the Phase II parcels were determined 

to be unaffected by activities at LEAD and, 

therefore, investigations and sampling were not 

warranted. 

To facilitate the transfer of the Phase II BRAC 

parcels where limited sampling was performed, a 

screening level risk assessment for human health 

effects was performed. The screening level risk 

assessment is a screening protocol (including 

comparison of the results to available risk-based 

criteria) that was developed by the Army, EPA, and 

PADEP, as discussed in more detail in Section 7 of 

this ROD. 

The results of the screening level risk assessment 

indicated that there was an acceptable risk due to 

potential direct contact with and/or inhalation of 

very low levels of PCBs in soil and concrete at the 

former PCB transformer sites based on future 

unlimited use and unrestricted exposure. In 

addition, the results of the Gate 1 Guardhouse 

screening level risk assessment indicated that there 

was acceptable risk based on the current and future 

industrial/commercial use. However, based on an 
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unlimited use scenario (i.e., residential or daycare), 

the results of the Gate 1 Guardhouse screening level 

risk assessment showed unacceptable risk due to 

potential direct contact with and/or inhalation of 

low levels of polyaromatic hydrocarbons and arsenic 

present in soil. 

These results support the conclusion that no 

remedial action is necessary to protect public health, 

welfare, or the environment at the Gate 1 

Guardhouse based on the intended future use of the 

site, but that remedial action is necessary for 

unlimited use and unrestricted exposure (i.e., 

residential or daycare use). In addition, these results 

support the conclusion that no remedial action is 

necessary to protect public health, welfare, or the 

environment at the former PCB transformer sites. 

A No Further Action Decision Document has been 

prepared to close out the former PCB transformer 

areas of concern. This ROD for the Phase II parcels 

documents the decision to limit the use of the Gate 1 

Guardhouse (Building 511) area to 

commercial/industrial use, and to prohibit 

residential or daycare use of this area. There were no 

constituents of concern associated with the former 

PCB transformer sites; therefore, a discussion of the 

site conceptual model for soils is not necessary. 

There were no constituents of concern for the Gate 1 

Guardhouse based on the intended future use; there 

are constituents of concern based on unlimited use 

and unrestricted exposure. Potential exposure routes 

for soils at the Gate 1 Guardhouse are direct contact 

(including ingestion) and inhalation of chemicals 

that are contained in soil in the area. Information 

pertaining to the soil investigations at the former 

PCB transformer sites and the Gate 1 Guardhouse is 

discussed in more detail in the following 

paragraphs. 

Former PCB Transformer Sites (Parcels 2-36, 

2-38, 2-45, 2-50, and 2-55) 

The Phase II parcel identification numbers and the 

buildings closest to where the former PCB 

transformers were located are as follows: 

!" Parcel 2-36 (Building 211) 

!" Parcel 2-38 (Building 7) 

!" Parcel 2-45 (Building 42) 

!" Parcel 2-50 (Building 18) 

!" Parcel 2-55 (Building 436) 

Parcel 2-36 is approximately 27 acres in size and is 

located on the eastern boundary of LEAD. The 

parcel is currently comprised of a railroad yard 

(Yard #1), a perimeter patrol road, open grassy 

areas, and Buildings 211 and 245. A PCB-containing 

transformer was removed in January 1994. 

Parcel 2-38 is approximately 5.5 acres in size and is 

located north of Building 8 and east of Building 4. 

The parcel consists of Buildings 7 and 1-7, and 

parking areas. Three PCB-containing transformers 

were removed in April 1993. 

Parcel 2-45 is approximately 5.3 acres in size and is 

located north of Building 52 and east of Building 43. 

The parcel contains Building 42. A PCB-containing 

transformer was removed in April 1995. 

Parcel 2-50 is approximately 2.9 acres in size and 

consists of some open storage space and Building 18. 

The parcel is located south of Building 38-1 and west 

of Michigan Avenue. Two PCB-containing 

transformers were present at Parcel 2-50; one was 

removed in November 1986 and the other in January 

1988. 

Parcel 2-55 is approximately 0.7 acre is size and is 

located north of Carbaugh Avenue and west of New 

York Avenue. The parcel consists of Building 436. 

Two transformers, at least one of which contained 

PCBs, were located on a utility pole on this parcel; 

the transformers were removed in January 1995. The 

transformer was associated with Building 426 for 

sampling purposes, but is located in Parcel 2-55. 

A detailed description of the former PCB 

transformer site investigation is presented in the 

Decision Document, Former PCB Transformer Sites in 

the Southeastern (SE) Area (WESTON, 2000b). In 1980, 

a sampling program was conducted at LEAD under 

the Toxic Substances Control Act to determine the 

PCB content of the electrical transformers. Some of 

these transformers were located within the 

boundaries of the Phase II parcels within the SE 

Area. 

Once these PCB-containing transformers were 

identified they were tracked in a program where 

they were checked every 3 months for leaks. There 

are no known records indicating that any of the 

PCB-containing transformers in the BRAC parcel 

leaked prior to removal. 

A field-sampling program was conducted in 1999 to 

determine if there was PCB contamination at these 

sites. Soil and asphalt/concrete chip samples were 

collected adjacent to the former PCB-transformer 

locations. Samples were focused toward stained 

and/or vegetatively stressed areas. PCBs were 

detected in low concentrations in asphalt and soil 

samples, ranging from 0.051 J to 0.340 J milligrams 

per kilogram (mg/kg). (The “J” following the 
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numbers is a “data qualifier.” It means that the 

samples definitely contained PCBs, but the 

concentrations of PCBs in the samples could not be 

precisely measured and are estimates.) Potential 

human health risks at the former PCB transformer 

sites were evaluated by screening the sample results 

against the risk-based screening criteria developed 

in the screening level risk assessment process and 

standards contained in the Toxic Substances Control 

Act regulations. The analytical results indicated that 

none of the sampling locations had PCB 

concentrations in excess of the 1 mg/kg cleanup 

level as defined in the Toxic Substances Control Act 

regulations. Note that the Toxic Substances Control 

Act cleanup level of 1 part per million PCBs was 

used to evaluate the potential risk from the 

concrete/asphalt samples because it is difficult to 

evaluate human health risk from PCBs in concrete or 

asphalt using standard risk assessment calculations. 

These locations are Building 7 in Parcel 2-38 and 

Building 42 in Parcel 2-45; the levels of PCBs 

detected do not pose an unacceptable risk to human 

health. 

The analytical results from the soil samples collected 

from the former PCB transformer site at Parcel 2-50 

(Building 18), the former PCB transformer site 

located near Building 211 (Parcel 2-36), and the 

former PCB transformer site near Building 436 

(Parcel 2-55) indicated that the levels of PCBs 

detected do not pose an unacceptable risk to human 

health. 

Gate 1 Guardhouse (Building 511) (Parcel 2R-80) 

Parcel 2R-80 is approximately 15.3 acres in size and 

consists of Coffey Avenue between Gate 1 and Gate 

6. The parcel includes Buildings 301 (Gate 6 

Guardhouse) and 511 (Gate 1 Guardhouse). Building 

511 serves as the gatehouse for entrance No. 1 to 

LEAD but is now vacant. Information from employee 

interviews and site records indicated that the 

building was heated by a furnace fueled by a 300-

gallon heating oil aboveground storage tank formerly 

located adjacent to the building. An underground 

storage tank (still in place) was used to store the 

heating oil prior to the use of the aboveground storage 

tank. An investigation was completed to determine if 

the underground storage tank had released any 

petroleum in the past. The details of the investigation 

are documented in the Gate 1 Guardhouse RI/RA

(WESTON, 2001b). 

The Gate 1 Guardhouse (Building 511) is located in 

Parcel 2R-80. Soil samples were collected from the 

vicinity of the guardhouse due to the presence of an 

abandoned underground storage tank at the site. 

Concentrations of polyaromatic hydrocarbons 

ranging from 0.039 J to 50 mg/kg, and some metals, 

including arsenic concentrations (ranging from 4.2 to 

11 mg/kg), exceeded the human-health risk-based 

concentrations for residential soils. However, the 

screening level risk assessment found that the level 

of risk was acceptable (based on EPA guidelines) 

based on a scenario of industrial/commercial use. 

Groundwater 

VOC-contaminated groundwater is known to exist 

or is suspected to be present beneath the Phase II 

parcels in the PDO and SE Areas. The primary 

chemicals of concern (COCs) detected are 

trichloroethene, 1,1,1-trichloroethane, 

1,1-dichlorethane, 1,2-dichloroethene, and 

tetrachloroethene, all of which have been detected at 

concentrations exceeding their respective maximum 

contaminant levels. Total VOC concentrations up to 

60 micrograms per liter (μg/L) and 112 μg/L have 

been detected in groundwater in the PDO and SE 

Areas, respectively. Risk assessments were 

performed for groundwater beneath the Phase II 

parcels, as discussed in more detail in Section 7 of 

this ROD, Summary of Site Risks. The conclusions of 

these risk assessments were that there is no 

unacceptable level of health risk from the 

groundwater pathways as long as groundwater use 

is restricted and the depth to groundwater is 3 or 

more feet away from (below) the floor or the 

workspace (including the bottom of the excavation 

floor for construction and utility work). This 3-ft (or 

more) space is called a “buffer zone.” A detailed site 

conceptual model for the groundwater is not 

presented herein because this ROD focuses on soils 

(i.e., the ROD supports the limited depth property 

transfer of the Phase II parcels, which does not 

include groundwater). However, the conceptual 

model for routes of exposure for groundwater is 

presented in Section 7, Summary of Site Risks.

SECTION 6 

CURRENT AND POTENTIAL 

FUTURE LAND AND RESOURCE 

USES 

LAND USE 

The majority of the land in the Phase II parcels 

portion of the SE Area is used for industrial, 

commercial (office space), and storage 

(warehousing) activities. There are areas of open 

land (including the golf course) interspersed in the 

Phase II parcels in the SE Area, which are 
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characterized as maintained grassy areas and small 

groves of trees. 

The Phase II parcels in the PDO Area consist of 

former base housing buildings, industrial activities, 

and open areas, some of which are leased for 

agricultural activities. Open lands in the Phase II 

parcels in the PDO Area include: large groves of 

secondary growth deciduous trees; grassy, 

maintained areas; vegetated natural and manmade 

drainageways; and fallow fields. To the west and 

north/northwest of the Phase II parcels in the SE 

Area are the PDO Area and the Ammunition Area of 

LEAD, respectively. 

In accordance with the LEAD reuse strategy report 

and discussions between the Army and LIDA, the 

future use of the Phase II parcels scheduled to be 

transferred to LIDA is planned for 

commercial/industrial use, with community/open 

space reuse for Parcel 2-74 and residential or 

community/open space use for Parcel 2-75. The 

majority of the Phase II parcels in the SE Area will 

continue to be used for industrial, commercial (office 

space), and storage (warehousing) activities. LIDA 

currently has specified plans in-place for industrial 

development at several Phase II parcels. One of the 

Phase II parcels in the PDO Area was leased for 

agricultural purposes; this area may continue to be 

leased by LIDA for agricultural use for the next few 

years. Parcel 2-74 is to be transferred to the 

Chambersburg Area School District with a planned 

future use as open space, community, agricultural 

(for education), and/or educational. Parcel 2-75 is to 

be transferred to the Chambersburg Area School 

District with continued use as residential housing, 

open space, community, agricultural (for education), 

and/or educational. 

GROUNDWATER USE

When LEAD was first constructed, Rocky Spring 

served as the Depot’s water supply. In the 1950s a 

groundwater study prepared for the U.S. Army 

Corps of Engineers (USACE) concluded that there 

was not a viable source of groundwater available 

within LEAD boundaries to supply the Depot’s new 

industrial mission (Acker, 1995). LEAD 

subsequently built a 300-million-gallon reservoir in 

Roxbury that continues to serve as the Depot’s water 

supply. 

The only use of groundwater in the area is off-post 

of LEAD, where some homes use individual water 

wells to supply their needs. Groundwater is also 

used off-post of LEAD as a water supply for 

livestock. Any homes on well water that exceeded 

the EPA regulatory value, which is referred to as the 

maximum contaminant level, were initially supplied 

with bottled water, and later connected to public 

water. 

Currently, there are restrictions on the on-post 

groundwater at LEAD (i.e., the groundwater is not 

used for drinking, irrigation, cooling, or any other 

purpose on Depot because of VOC contamination). 

Upon transfer of the Phase II parcels to LIDA, the 

groundwater underlying the parcels will not be used 

for any purpose without the prior written approval 

of the Army, PADEP, and EPA. The groundwater 

use restrictions will be imposed through the 

environmental provisions of the property deed and a 

Land Use Control Assurance Plan. 

SURFACE-WATER USE 

There are no surface water bodies in the Phase II 

BRAC parcels. 

SECTION 7

SUMMARY OF SITE RISKS 

Based on the results of the environmental baseline 

survey (WESTON, 1996, 1999a, 2000a), the Phase II 

parcels containing the Gate 1 Guardhouse (Parcel 

2R-80) and several former PCB transformer sites 

(Parcels 2-36, 2-38, 2-45, 2-50, and 2-55) were found 

to have elevated levels of chemicals in soils. These 

levels indicated that hazardous substances have 

been released into the soil at some of the Phase II 

parcels, including an area near the Gate 1 

Guardhouse. Prior to an evaluation of risk, it was 

thought that these chemicals could potentially pose 

human health risks to people who may be exposed 

to those soils. Therefore, for these sites, a screening 

level risk assessment was conducted to determine if 

the human health risk associated with potential 

exposure to soils was within a range considered 

acceptable by the Base Closure Team. 

A screening level risk assessment compares the 

concentrations of hazardous substances in soil to 

chemical concentrations corresponding to fixed 

levels of risk, e.g., a lifetime cancer risk of one-inone-million (1-in-1,000,000 or 1 x 10-6). Not as 

comprehensive as a baseline risk assessment, it 

nevertheless incorporates the principal technical 

elements of a baseline assessment. The Army, EPA 

Region III, and PADEP reviewed and agreed upon 

the screening level risk assessment methodology. 

The screening level approach is consistent with EPA 

policy, Land Use in the CERCLA Remedy Selection 

Process (Office of Solid Waste and Emergency 
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Response [OSWER] Directive No. 9355.7-04, 25 May 

1995) (EPA, 1995). The approach is outlined in 

Figure 2-1 in Attachment 2 to this ROD. The 

screening level risk assessment process is described 

in more detail in the inset on the following page. 

In addition to soil contamination at the Gate 1 

Guardhouse and the former PCB transformer sites, 

VOCs have been released into the groundwater 

underlying a number of the Phase II parcels in the 

PDO and SE Areas; a number of other chemicals 

were also found in groundwater. The health risks 

associated with current and potential future 

exposure to groundwater at the PDO and the SE 

Area sites were evaluated in the documents: 

!" Risk Assessment of the Property Disposal Office Area 

at Letterkenny Army Depot Operable Units 1 and 2, 

Final Report (ESE, 1993b). 

!" Risk Assessment of the Southeastern Area at 

Letterkenny Army Depot Operable Units One and 

Three, Final Report (ESE, 1994). 

Summaries of the media-specific human health 

evaluations are provided in the following 

subsection. 

The remedy selected in this ROD is necessary to 

protect public health or welfare or the environment 

from actual releases of hazardous substances into 

the environment. 

The Army and EPA, in consultation with PADEP, 

have determined that no action is necessary to 

protect public health or welfare or the environment 

from the soil at the Phase II parcels, with the 

exception of soil in an area near the Gate 1 

Guardhouse. 

SUMMARY OF HUMAN HEALTH RISKS 

A multistep process was used in the screening level 

risk assessments that were performed for soils of the 

Gate 1 Guardhouse and the former PCB transformer 

sites, as well as the baseline risk assessments for the 

groundwater underlying the Phase II parcels. The 

steps and the technical elements of each of those 

steps used in the baseline risk assessment and the 

screening level risk assessments are provided in the 

inset on this page. 

Human health risks were evaluated for exposures to 

contaminants (also referred to as chemicals of 

concern [COCs]). COCs are chemicals that are found 

in site media, such as soil, groundwater, or air, that 

are identified for further risk evaluation based on a 

number of factors. These factors include the 

chemical’s degree of toxicity, concentration, 

frequency of detection, and chemical properties 

important to the release, transport, and potential to 

come in contact with people. COCs are specific to 

each site and medium of concern (e.g., soil, air, 

groundwater). 

WHAT IS RISK AND HOW IS IT CALCULATED? 

Baseline Risk Assessment 

A CERCLA human health risk assessment estimates the 

"baseline risk." This is an estimate of the likelihood of health 

problems occurring if no cleanup action were taken at a site. To 

estimate the baseline risk at a CERCLA site, the Army, EPA, and 

PADEP undertake a four-step process: 

Step 1: Identification of Chemicals of Concern 

Step 2: Exposure Assessment 

Step 3: Toxicity Assessment 

Step 4: Risk Characterization 

In Step 1, the concentrations of contaminants found at a site, as 

well as past scientific studies on the effects these contaminants 

have had on people (or animals, when human studies are 

unavailable), are considered. Comparisons between site-specific 

concentrations and concentrations reported in past studies help 

determine which contaminants are most likely to pose the 

greatest threat to human health. 

In Step 2, the different ways that people might be exposed to the 

contaminants identified in Step 1, the concentrations that people 

might be exposed to, and the potential frequency and duration of 

exposure are considered. Using this information, a "reasonable 

maximum exposure" (RME) scenario is calculated, which portrays 

the highest level of human exposure that could reasonably be 

expected to occur. 

In Step 3, the information from Step 2 is used in combination with 

information on the toxicity of each chemical to assess potential 

health risks. There are two types of risk: cancer risk and 

noncancer risk. The likelihood of any kind of cancer resulting 

from a CERCLA site is generally expressed as an upperbound 

probability; for example, a "1-in-1,000,000 chance." In other 

words, for every 1,000,000 people that could be exposed, one 

extra cancer may occur as a result of exposure to site 

contaminants. An extra cancer case means that 1 more person 

could get cancer than would normally be expected to from all 

other causes. For noncancer health effects, a "hazard index" (HI) 

is calculated. The key concept here is that a "threshold level" 

(measured usually as a hazard index of less than 1) exists below 

which noncancer health effects are no longer predicted. 

In Step 4, a determination is made on whether site risks are great 

enough to cause health problems for people at or near the 

CERCLA site. The results of the three previous steps are 

combined, evaluated, and summarized. The potential risks from 

the individual exposure pathways are added to provide the total 

risk.

The completion of the dual-step screening level risk 

assessment process and subsequent site-specific 

background (i.e., reference) data comparison is 

intended to provide the necessary information to 

facilitate a decision by the BRAC Cleanup Team to 

recommend site clearance or a more detailed 

investigation such as additional sampling or a 

baseline risk assessment. 
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WHAT IS RISK AND HOW IS IT CALCULATED? 

Screening Level Risk Assessment

The screening level risk assessment process is a streamlined 

approach for identifying potential contaminants of concern 

(COCs) and estimating health risks at sites (also referred to here 

as parcels) not known or not expected to have widespread 

contamination. The first step (i.e., Level 1) in the human health 

screening level risk assessment process determines the potential 

COCs by comparing the maximum levels of chemicals found at 

the site to published (or calculated using published EPA 

guidance) risk-based benchmarks, also referred to as screening 

levels, developed for sites to be used for residential purposes. 

This method measures risks to human health by comparing 

concentrations of hazardous substances found in the soil with 

theoretical concentrations developed by EPA and PADEP, which 

are considered not to pose an unacceptable risk to human health. 

Chemicals that have maximum concentrations greater than the 

lowest benchmark are carried into the second step of the 

evaluation. Residentially based benchmarks are more 

conservative than those based on industrial use, and at the 

request of EPA Region III, are used to ensure that a conservative 

list of potential COCs is selected. 

For sites that have chemicals exceeding the Level 1 screen, the 

assessment of potential health effects is refined in the second 

step (i.e., Level 2) by calculating estimates of the cancer and 

noncancer risks for those potentially exposed to soils at the site. 

This is done by first determining the “exposure point 

concentration” for each chemical by statistically evaluating the 

site data. The “exposure point concentration” represents a 

concentration of chemicals(s) that a person at the site may be 

exposed to, in a worst case. Then site-specific, risk-based health 

benchmarks are calculated based on specified risk level goals for 

each exposure scenario. This means that the benchmark number 

is calculated to represent a concentration of chemical that, if a 

site user or worker were exposed to the chemical at levels above 

this benchmark concentration, their health may be at risk at an 

unacceptable level. Exposure scenario refers to an evaluation of 

what types of people use the site, how people use the site now, 

and will use the site in the future, and ways in which they can be 

exposed to chemicals, such as ingestion of soil due to lawn 

maintenance by a maintenance worker. The cancer and 

noncancer risks are then estimated with a calculation procedure 

that uses the exposure point concentration and the site-specific 

benchmarks. If the estimated risk is not unacceptable (see inset 

on acceptable levels of exposure), then the parcel is deemed 

suitable for property transfer. 

If any chemicals exceed Level 2 benchmarks, the levels of those 

potential COCs at the site are compared statistically to levels of 

the chemicals found in soil samples from areas not affected by 

past activities at the site (also referred to as site-specific 

“background”). If the values at the site are not statistically 

different than “background” concentrations, then it can be 

determined that detected levels of chemicals are not site-related. 

If the screening level risk assessment results determine that a 

parcel does not pose a threat to human health based on the 

present and intended future use (e.g., industrial/commercial), the 

parcel is deemed suitable for property transfer. 

WHAT ARE ACCEPTABLE LEVELS OF EXPOSURE ? 

Current Federal guidelines for acceptable exposures are: 

(1) an individual lifetime excess carcinogenic risk in the range of 

a one-in-ten-thousand (1-in-10,000 or 1 x 10-4) to one-in-onemillion (1-in-1,000,000 or 1 x 10-6); and (2) a maximum hazard 

index equal to 1.0 for noncancer (also referred to as 

noncarcinogenic) effects. A hazard index greater than 1.0 

indicates a potential for noncancer effects. 

Soil 

Gate 1 Guardhouse (Building 511) 

A detailed description of the risk assessment that 

was performed for the Gate 1 Guardhouse is 

presented in the Remedial Investigation and Risk 

Assessment Report for the Gate 1 Guardhouse, Building 

511, Southeastern Area (SE) Operable Unit (OU) 8, 

Final (WESTON, 2001b). The following is a summary 

of the risk assessment. 

Identification of Chemicals of Concern (COCs)

The Gate 1 Guardhouse (Building 511) is located in 

Parcel 2R-80. Soil samples were collected from the 

vicinity of the guardhouse due to the presence of 

existing or former storage tanks at the site. 

Polyaromatic hydrocarbon organics and several 

metals were identified as COCs. A complete list of 

COCs and their ranges of concentrations are 

provided in Attachment 2, Table 1A. 

Exposure Assessment 

Present Use Scenarios 

Under current conditions, potential exposure at the 

Gate 1 Guardhouse is limited to workers engaged in 

property maintenance. Risks to current site workers 

were quantitatively evaluated for exposure to 

contaminants in surface soil through incidental 

ingestion of contaminated soil and dermal contact 

with contaminated soil. 

Future Use Scenarios

Commercial and industrial future use scenarios were 

evaluated based on the anticipated future use of the 

site at the time this assessment was prepared. Under 

potential future site conditions, risks to commercial 

and industrial site workers and construction workers 

at the Gate 1 Guardhouse were quantitatively 

evaluated for exposures to surface and subsurface 

soils. The exposure routes selected for evaluation 

included ingestion of contaminated soil, dermal 

contact with contaminated soil, and inhalation of 

contaminated dust. For this assessment, it was 

assumed that exposure to commercial and industrial 

workers would occur over a conservative period of 

25 years, the assumed duration of employment at 

any one location. Exposures of construction workers 

to surface and subsurface soils were assumed to 

occur in a short-term (less than 1 year) period of 

construction requiring excavation of soils. 

Toxicity Assessment

In evaluating potential health risks, both cancercausing and noncancer-causing effects from 

exposure to soil were considered. The potential for 
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producing cancer-causing effects is limited to those 

substances that have been shown to produce cancer 

in animals and/or humans. Excessive exposure to all 

substances, carcinogenic or not, can produce adverse 

noncancer health effects. Therefore, cancer slope 

factors were identified for those chemicals classified 

as carcinogens and reference doses, when available, 

were identified for every chemical selected 

regardless of its classification. Reference doses 

indicate the potential for adverse health effects from 

exposure to COCs exhibiting noncancer effects. 

Carcinogens 

EPA has developed cancer slope factors for 

estimating excess lifetime cancer risks associated 

with exposure to potentially carcinogenic COCs. 

Cancer slope factors are derived from the results of 

human epidemiological studies or animal bioassays 

to which animal-to-human extrapolation and 

uncertainty factors have been applied. Cancer slope 

factors used in the screening level risk assessment 

were obtained from EPA’s Integrated Risk 

Information System (IRIS) database. Slope factors 

not available on IRIS were obtained from EPA’s 

second most current source of toxicity information, 

the Health Effects Assessment Summary Tables 

(HEAST). At this time, slope factors are not available 

for the dermal route of exposure. Dermal slope 

factors used in the assessment have been 

extrapolated from oral slope values used in this 

assessment. 

Noncarcinogens 

EPA has developed media-specific reference doses 

for indicating the potential for adverse health effects 

from exposure to COCs exhibiting noncancer effects. 

Reference doses are derived from human 

epidemiological studies or animal studies to which 

uncertainty factors have been applied. Reference 

doses used in the screening level risk assessment 

were obtained from EPA’s IRIS database. Reference 

doses not available on IRIS were obtained from 

EPA’s second most current source of toxicity 

information, HEAST. 

Risk Characterization

The results of the screening level risk assessment 

indicated that the risks to industrial or commercial 

workers from site soil are within limits considered 

acceptable to EPA. 

None of the scenarios of exposure through industrial 

or commercial use exceeded these guidelines for 

acceptable exposure. Therefore, Parcel 2R-80 is 

suitable for use for industrial/commercial purposes. 

Parcel 2R-80 will be included in the Phase II parcel 

transfer because there are no unacceptable risks 

based on the intended industrial/commercial use. 

Published screening values used for the screening 

level risk assessment follow; the assumptions for 

calculating these values are available in the citations 

listed. 

Adjusted EPA Region III Risk-Based Concentrations 

(U.S. Environmental Protection Agency, Risk-Based 

Concentration Tables, EPA Region III, Philadelphia, 

PA 19103, 5 November 2000). 

EPA Region III maintains a list of risk-based 

concentrations (RBCs) for chemicals in various 

media (e.g., soil, water, air) that correspond to a 

target cancer risk of 1 x 10-6 (1-in-1,000,000) or a 

target noncancer hazard quotient (referred to as a 

hazard index when calculated for a site) of 1. For the 

purposes of identifying the contaminants of 

potential concern, the residential soil ingestion riskbased concentrations were adjusted to reflect a riskbased screening concentration (i.e., RBSC). Riskbased screening concentrations for carcinogens were 

developed at a target risk of 1 x 10-6. For chemicals 

associated with noncancer health effects, the target 

hazard quotient was adjusted to 0.1, thus lowering 

the noncancer risk-based concentration values 

presented in the risk-based table by an order of 

magnitude to address the additivity of noncancer 

effects when there is exposure to multiple chemicals. 

As noted in the EPA Region III risk-based 

concentration table, carcinogens that are adjusted to 

a 0.1 hazard quotient become the more conservative 

value than the carcinogenic value at a target risk of 1 

x 10-6. In these instances, the noncancer value was 

used. 

EPA Site Screening Levels for VOCs and Particulate 

Inhalation (U.S. Environmental Protection Agency, 

1996, Soil Screening Guidance: Technical Background 

Document, EPA/540/R-956/128, PB96-963502, Office 

of Solid Waste and Emergency Response, Washington, 

DC. May 1996; U.S. Environmental Protection 

Agency, Soil Screening Guidance: Technical 

Background Document and Soil Screening Guidance: 

User’s Guide, 9355-4.23, EPA/540/R-96/018, PB96-

963505, Office of Solid Waste and Emergency 

Response, Washington, DC, April 1996; and U.S. 

Environmental Protection Agency, Soil Screening 

Calculations, www.epa.gov/oerrpage/ 

superfund/programs/risk/calc_sta.htm). 

Site screening levels (SSLs) for inhalation exposure 

to organic compounds (VOCs) and metals 

(particulates) from soil were calculated for all 

detected chemicals for each site using the EPA Soil 

Screening Guidance calculations. The target risk and 
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target hazard quotient are identical to those used in 

calculating risk-based screening concentrations. For 

the purposes of contaminant of potential concern 

screening, oral reference doses were extrapolated to 

the inhalation route when no inhalation toxicity 

criteria were available. 

Conventionally, inhalation soil screening levels were 

evaluated using the acceptable daily intake 

approach, which uses the unit risk factor or 

reference concentration values for an adult 

exposure. The inhalation soil screening level 

calculation method and input assumptions for 

cancer effects, as described in the EPA guidance, 

were modified at the request of EPA Region III to 

estimate values for the age-adjusted child and adult. 

EPA Region III requested that the Army estimate 

noncancer inhalation soil screening levels based on 

childhood exposure. Because the inhalation 

equations defined in the soil screening level 

guidance use unit risk factor or reference 

concentration values, the calculation method was 

adjusted to reflect the child’s body weight and 

inhalation rate. 

The volatilization factors were estimated on a 

chemical-specific basis. The Harrisburg region was 

selected as the input value to the calculation for 

wind dispersion because this location is the one 

closest to Chambersburg, PA. 

EPA Soil Screening Levels for Protection of 

Groundwater (see EPA soil screening level citations 

listed previously). 

Soil screening levels for groundwater protection 

were calculated for all detected site chemicals. The 

conventional method of using the EPA maximum 

contaminant level (MCL), action level, or healthbased limit in the EPA Soil Screening Guidance was 

modified by substituting these criteria with the EPA 

Region III tap water risk-based concentrations at a 

target cancer risk of 1 x 10-6 or at an adjusted target 

hazard quotient of 0.1. A dilution-attenuation factor 

of 1 was used to achieve the most conservative soil 

screening level; this means that one is assuming that 

there is little dilution if a contaminant would 

migrate to groundwater. Default (or standard) 

inputs provided in the EPA guidance were used for 

all other values. Any chemical exceeding soil 

screening levels for groundwater protection were 

qualitatively evaluated in the screening level risk 

assessment for its potential impact on groundwater. 

PADEP Medium-Specific Concentrations (MSCs) 

(Commonwealth of Pennsylvania, Rules and 

Regulations, Title 25 – Environmental Protection, 

Environmental Quality Board [25 PA Code Chapter 

250], Administration of the Land Recycling Program 

[Act 2], Pennsylvania Bulletin, Vol. 27, No. 33, 

16 August 1997). 

If EPA Region III risk-based concentrations or soil 

screening levels were not available for a chemical, 

and a toxicity value for the chemical in question 

could not be obtained through the National Center 

for Environmental Assessment or other source 

provided by the EPA Region III toxicologist, then 

Pennsylvania Act 2 guidance was consulted for 

medium-specific concentrations for soil ingestion 

and inhalation of VOCs or particulates. Mediumspecific concentrations are chemical-specific riskbased concentrations developed in a way similar to 

the EPA Region III risk-based concentrations. The 

medium-specific concentration tables are based on a 

target risk of 1 x 10-5 and a target hazard quotient of 

1. For the purposes of the screening evaluation, the 

target risk was adjusted to 1 x 10-6, and the target 

hazard quotient adjusted to 0.1. The PADEP Act 2 

guidance contains the calculation methods.

Because EPA Region III does not recommend the use 

of PADEP benchmarks for contaminants of potential 

concern screening, any contaminants of potential 

concern that will be selected only as a result of 

medium-specific concentration comparisons will be 

footnoted in the respective tables and discussed in 

the uncertainty analysis relative to their impacts on 

contaminants of potential concern selection. 

Former PCB Transformer Sites 

A detailed description of the risk assessment that 

was performed for the former PCB transformer sites 

is presented in the Decision Document, Former PCB 

Transformer Sites in Southeastern (SE) Area, Operable 

Unit (OU) 8, (DSERTS Site LEAD-125), Final 

(WESTON, 2000b). The following is a summary of 

the risk assessment. 

The screening level assessment for the former PCB 

transformer sites focused on PCBs because the 

potential risk associated with contaminated soils at 

the sites was limited to PCBs. The investigation at 

the former PCB transformer sites included sampling 

and analysis of concrete and asphalt samples, which 

cannot be evaluated using the standard risk 

assessment approach or the screening level risk 

assessment procedure. Therefore, the risk evaluation 

for the former PCB transformers sites also included 

comparison to regulations under the Toxic 

Substances Control Act designed to be protective of 

human health and the environment. 

The Phase II parcels containing PCB transformers 

that were evaluated for human health risk are as 

follows: 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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!" Parcel 2-36, Building 211 

!" Parcel 2-38, Building 7 

!" Parcel 2-45, Building 42 

!" Parcel 2-50, Building 18 

!" Parcel 2-55, Building 436 

COCs at each of these parcels were limited to PCBs. 

The analytical results of the soil were compared with 

the lowest applicable EPA and PADEP criteria as 

provided in Attachment 2, Tables 1B and 1C. The 

asphalt/concrete samples were compared to the 

standards under the Toxic Substances Control Act as 

shown in Table 1C. The analytical results indicated 

that none of the locations where concrete and 

asphalt samples were collected had PCB 

concentrations in excess of the 1-mg/kg cleanuplevel as defined in the regulations established under 

the Toxic Substances Control Act. These locations 

are Building 7 in Parcel 2-38, and Building 42 in 

Parcel 2-45. 

The 1-mg/kg concentration is the Toxic Substances 

Control Act cleanup level for PCB remediation waste 

for a “high occupancy area.” A high occupancy area 

means any area where PCB remediation waste has 

been disposed of on-site and where occupancy for 

any individual not wearing dermal and respiratory 

protection for a calendar year is: 840 hours or more 

(an average of 16.8 hours or more per week) for 

nonporous surfaces, and 335 hours or more (an 

average of 6.7 hours or more per week) for bulk PCB 

remediation waste. Examples include a residence, 

school, daycare center, sleeping quarters, a single or 

multiple occupancy 40 hours per week work station, 

a school classroom, a cafeteria in an industrial 

facility, a control room, and a work station on an 

assembly line. 

The analytical results of the soil samples collected 

from Parcel 2-50 (Building 18) and Parcel 2-55 

(Building 436) indicated that PCB concentrations 

were less than the most restrictive soil screening 

level of 0.25 mg/kg (Attachment 2, Table 1C). This 

soil-screening level is a concentration in soil that is 

considered to be protective of underlying drinking 

water. 

An average soil value of 0.32 mg/kg at Parcel 2-36 

(Building 211) was slightly above the soil 

concentration published by EPA, which was 

developed to be protective of groundwater 

(0.25 mg/kg). Because a number of very 

conservative assumptions are used by the agency to 

derive this value and the resultant risk is very close 

to 1 x 10-6, the soils at Building 211 (Parcel 2-36) do 

not present an unacceptable risk. 

GROUNDWATER 

Identification of Chemicals of Concern (COCs) 

PDO Area

A summary of the COCs in the groundwater 

underlying the PDO Area is presented in 

Attachment 2, Table 2. 

The COCs included VOCs, semivolatile organic 

compounds (SVOCs), pesticides, and metals. 

SE Area

A list of the COCs in groundwater underlying the SE 

Area is presented in Attachment 2, Table 3. As with

the PDO Area, the COCs for the SE Area included 

VOCs, SVOCs, pesticides, and metals. 

The COCs and concentrations of these COCs in 

groundwater used for the evaluation of 

groundwater vapor intrusion into buildings and 

trenches are presented in Attachment 2, Table 4. This 

exposure scenario was limited exclusively to VOCs 

because they are the only chemicals with the 

potential to volatilize from groundwater into 

buildings. These COCs apply to both the SE Area 

and the PDO Area. 

Exposure Assessment 

For Phase II parcels in both the PDO and SE Areas, a 

conceptual model of human exposure was 

developed that identified potential pathways by 

which exposure could occur; characterized the 

potentially exposed populations (e.g., workers and 

recreational users); and estimated the magnitude, 

frequency, and duration of exposure. Conceptual 

site models of human exposure to groundwater in 

the PDO and SE Areas are provided in Figures 5 and

6, respectively. 

PDO Area

The exposure scenarios evaluated under current 

land use conditions at the Phase II parcels in the 

PDO Area included the following: 

!" On-site worker: inhalation of VOCs that 

volatilize from underlying groundwater. 

The receptors and pathways of exposure that were 

evaluated under the future land use conditions 

included: 

!" On-site industrial/commercial worker: 

inhalation of COCs that volatilize from 

underlying groundwater; consumption of COCs 

in groundwater: 
E 5 CONCEPTUAL SITE MODEL FOR LEAD PDO AREA GROUNDWATER RISK ASSESSMENT

Soil GW

Air

(Vapors)

SECONDARY

SOURCE

EXPOSURE

MEDIA

PATHWAYS

HUMAN

Ingestion

W Rec/Res

EXPOSURE

ROUTE

e Revetments

ot located on Phase II BRAC Parcels)

Inhalation
RE 6 CONCEPTUAL SITE MODEL FOR LEAD SE AREA GROUNDWATER RISK ASSESSMENT

Ambient

Air

(Vapors)

SECONDARY

SOURCE

EXPOSURE

MEDIA

PATHWAYS

a

astewater Treatment Plant

dustrial Area

Ingestion

Inhalation

HUMAN

W Rec/Res

EXPOSURE

ROUTE

Inhalation

Soil

Groundwater
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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!" On-site industrial/commercial worker: 

inhalation of VOCs while showering; inhalation 

of COCs that volatilize from groundwater and 

migrate through building floors to basements 

and other inhabited areas. 

!" On-site construction worker: inhalation of COCs 

that volatilize from underlying groundwater 

into construction trenches. 

!" On-site adult and child resident and recreational 

users: inhalation of COCs that volatilize from 

groundwater and migrate through building 

floors to basements and other inhabited areas. 

SE Area

The exposure scenarios evaluated under current 

land use conditions at the Phase II parcels in the SE 

Area included the following: 

!" On-site worker: inhalation of COCs that 

volatilize from underlying groundwater. 

The exposure scenarios evaluated under potential 

future use conditions at the Phase II parcels in the SE 

Area included the following: 

!" On-site commercial/industrial worker: 

inhalation of COCs that volatilize from 

underlying groundwater, consumption of 

groundwater, and inhalation of VOCs while 

showering. 

!" On-site commercial/industrial worker: 

inhalation of COCs that volatilize from 

groundwater and migrate through building 

floors into basements and other occupied areas. 

!" On-site construction worker: inhalation of COCs 

that volatilize from underlying groundwater 

into construction trenches. 

!" On-site adult and child resident and recreational 

users: inhalation of COCs that volatilize from 

groundwater and migrate through building 

floors to basements and other inhabited areas. 

All pathways were quantified for potential exposure 

and consequent risk. Exposure models and 

assumptions used to estimate exposure for the 1993 

and 1994 risk assessments (ESE, 1993b, 1994) are 

provided in Attachment 2, Table 5. 

Assumptions for the evaluation of groundwater 

vapor intrusion into buildings and trenches are 

presented in Attachment 2, Table 6.

Toxicity Assessment 

In evaluating potential health risks, both cancercausing and noncancer-causing effects from 

exposure to groundwater were considered. The 

potential for producing cancer-causing effects is 

limited to those substances that have been shown to 

produce cancer in animals and/or humans. 

Excessive exposure to all substances, carcinogenic or 

not, can produce adverse noncancer health effects. 

Therefore, cancer slope factors were identified for 

those chemicals classified as carcinogens, and 

reference dose, when available, were identified for 

every chemical selected regardless of its 

classification. 

Carcinogens 

EPA has developed cancer slope factors for 

estimating excess lifetime cancer risks associated 

with exposure to potentially carcinogenic COCs. 

Cancer slope factors are derived from the results of 

human epidemiological studies or animal bioassays 

to which animal-to-human extrapolation and 

uncertainty factors have been applied. The weightof-evidence classifications for potential carcinogens 

evaluated in the assessment of human health risk are 

provided in Attachment 2, Table 7. The cancer slope 

factors used in the evaluation of cancer risk due to 

exposure to groundwater in the PDO and SE Areas 

at LEAD are provided in Attachment 2, Table 8. 

Noncarcinogens 

EPA has developed media-specific reference doses 

for indicating the potential for adverse health effects 

from exposure to COCs exhibiting noncancer effects. 

Reference doses are derived from human 

epidemiological studies or animal studies to which 

uncertainty factors have been applied. The reference 

doses used in the evaluation of noncancer risks 

resulting from exposure to groundwater in the PDO 

and SE Areas at LEAD are provided in Attachment 

2, Table 8. 

The toxicity values used for the evaluation of 

groundwater vapor intrusion into buildings and 

trenches are presented in Attachment 2, Table 9.

Risk Characterization 

The risk characterization presents the nature and the 

degree of the potential carcinogenic and 

noncarcinogenic (noncancer) risks posed to the 

current and future human health receptors 

presented previously in the exposure assessment. 
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For carcinogens, risks are generally expressed as the 

incremental probability of an individual developing 

cancer over a lifetime as a result of exposure to the 

carcinogen. Excess lifetime cancer risk is calculated 

from the following equation: 

Risk = CDI x CSFs 

Where: 

Risk = A unitless probability of an individual 

developing cancer. 

CDI = Chronic daily intake averaged over 70 

years (mg/kg-day). 

CSF = Cancer slope factor, expressed as 

(mg/kg-day) –1. 

These risks are probabilities that usually are 

expressed in scientific notation (e.g., 1 x 10-6). An 

excess lifetime cancer risk of 1 x 10-6 indicates that an 

individual experiencing the reasonable maximum 

exposure estimate has a 1-in-1,000,000 chance of 

developing cancer as a result of site-related 

exposure. EPA’s generally acceptable range for siterelated exposures is 1 x 10-4 to 1 x 10-6. 

The potential for noncancer effects is evaluated by 

comparing an exposure level over a specified time 

period with a reference dose for a similar exposure 

period. A reference dose represents a level that an 

individual may be exposed to that is not expected to 

cause any harmful effects. The ratio of exposure to 

toxicity is called a hazard quotient (HQ). A hazard 

quotient less than 1 (<1) indicates that a receptor’s 

dose of a single contaminant is less than the 

reference dose, and that toxic noncancer effects from 

that chemical are unlikely. The hazard index (HI) is 

generated by adding the hazard quotients for all 

COCs that affect the same target organ (e.g., liver) or 

that act through the same mechanism of action 

within a medium (e.g., soil, groundwater, or air) or 

across all media to which a given individual may be 

reasonably exposed. A hazard index less than 1 

(<1) indicates that the noncancer effects from all 

contaminants are unlikely. A hazard index greater 

than 1 (> 1) indicates that site-related exposures may 

present a risk to human health. 

The hazard quotient is calculated as follows: 

Noncancer HQ = CDI/RfD 

Where: 

 CDI = Chronic daily intake. 

 RfD = Chemical-specific reference dose. 

PDO Area

The worker exposed through the potential 

consumption of groundwater, a highly unlikely 

scenario, and the inhalation of volatiles was 

evaluated for the PDO Area. The cumulative risk 

associated with the consumption of groundwater 

and the inhalation of volatiles was estimated at 4 x 

10-4 or four-in-ten thousand (4-in-10,000), which is 

above EPA’s acceptable range for site-related 

exposures. 

Those chemicals presenting the most significant risk 

due to exposure to groundwater were 

1,1-dichloroethene and 1,1-dichloroethane. These 

chemicals represented more than 90% of the total 

cancer risk, primarily through groundwater 

consumption. A cumulative noncancer risk, 

resulting in a hazard index of 3.3, was due 

principally to exposure to 1,2-dichloroethene (total) 

and thallium. These chemicals represented more 

than 90% of the total noncancer risk. 

Indirect exposure resulting from the migration of 

VOCs from groundwater into construction trenches 

and through building floors into basements or other 

workspaces was evaluated. The results of this 

evaluation are provided in the Groundwater Vapor 

Intrusion Risk Assessment report (WESTON, 2001c). 

For the PDO Area, the risk of cancer to residents 

(unrestricted use scenario) associated with exposure 

through the inhalation of COCs volatilized from 

groundwater into homes is within the current EPA 

guidelines for acceptable exposure (risk to an adult: 

8.27 x 10-6;risk to a child: 4.99 x 10-6). These numbers 

are conservative because they represent a sitewide 

risk based on maximum groundwater concentrations 

found throughout both the PDO Area and SE Area. 

For the PDO Area (and the SE Area), exposure to 

residents from the inhalation of COCs volatilized 

from groundwater, expressed in a noncancer risk, is 

well below EPA’s hazard index threshold of 1 (adult: 

0.008; child: 0.02). This result assumes that there is a 

3-ft buffer zone maintained between the buildings or 

the bottom of the trench and the level of 

groundwater below. None of the results indicate that 

this pathway poses an unacceptable human health 

risk to future construction and commercial workers, 

child recreational users, or residents at the Phase II 

parcels in the PDO Area. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

O:\02281016.008\PHASE II\ROD\ROD_MAY 30.DOC FINAL 25 

SE Area

Although considered a highly unlikely exposure 

scenario, the carcinogenic and noncancer risks 

associated with the potential consumption of 

groundwater by a future worker were evaluated. 

The results of this evaluation indicated a potential 

cancer risk of as much as 6.0 x 10-3 or an excess 

lifetime cancer risk of 6-in-10,000. Exposure to vinyl 

chloride represented more than 75% of the cancer 

risk. Other chemicals found in groundwater that 

significantly contribute to the cancer risk were 

groundwater consumed included trichloroethylene, 

1,1-dichloroethene, and 1,2-dichloroethane. In 

addition, the noncancer risk associated with this 

exposure resulted in a hazard index of 110. The 

majority of the noncancer risk resulted from 

potential consumption of trichloroethylene in 

groundwater. 

Indirect exposure resulting from the migration of 

VOCs from groundwater into construction trenches 

and through building floors into basements or other 

workspaces was evaluated. The results of this 

evaluation are provided in the Groundwater Vapor 

Intrusion Risk Assessment report (WESTON, 2001c). 

The results for this pathway are the same as shown 

above for the PDO Area because these results 

represent sitewide risk for residential use based on 

maximum groundwater concentrations found 

throughout the site. None of these results indicate 

that this pathway poses an unacceptable human 

health risk to future construction or commercial 

workers, child recreational users, or residents at the 

Phase II parcels in the SE Area. 

SUMMARY OF ECOLOGICAL RISKS 

Soils 

With the exception of the Gate 1 Guardhouse and 

the former PCB transformer sites, the soils of the 

Phase II parcels were unaffected by site activities, 

and therefore, there are no unacceptable risks to 

plants and animals that may use these areas. At both 

the Gate 1 Guardhouse and the former PCB 

transformer sites, no suitable habitats exist for 

significant use by wildlife; consequently, an 

assessment of ecological risk was not performed. 

Groundwater

The potential for plants and animals to be exposed to 

groundwater in the Phase II parcels is minimal. 

Groundwater does not come to the surface or 

discharge to surface streams, ponds, or wetlands in 

the Phase II parcels, and therefore, no pathway of 

exposure to plants and wildlife exists. Therefore, 

there is no ecological risk posed by contaminated 

groundwater to wildlife receptors that inhabit the 

Phase II parcels.

UNCERTAINTY ANALYSIS 

Virtually every step in the risk assessment process 

requires a number of assumptions, all of which 

contribute to uncertainty in the assessment of risk. In 

the absence of site-specific information, assumptions 

are developed based on “best estimates” of data 

quality (e.g., are there enough samples?), exposure 

parameters (e.g., how often would a worker contact 

the soil outside the building in which he works?), 

and toxicity information (how valid is the 

extrapolation of toxicity data taken from rat studies 

to humans?). To assist in the development of these 

estimates, EPA has developed and recommends the 

use of “standard” factors that are designed to 

promote consistency in risk assessments and provide 

a plausible estimate of the risk. In the absence of sitespecific information (please note that much of this 

assessment was performed for workers who may 

use these sites in the future), the risk assessments 

conducted here used EPA’s “standard” (also known 

as “default”) assumptions. The extent to which these 

factors accurately predict risk depends on how close 

they are to site-specific conditions. 

In the presence of such uncertainty, EPA and the risk 

assessor have the obligation to make conservative 

assumptions such that the chance is very small for 

the actual health risk to be greater than that 

determined through the risk process. On the other 

hand, the process is not to yield absurdly 

conservative risk values that have no basis in reality. 

That balance was kept in mind in the development 

of exposure assumptions and pathways, and in the 

interpretation of data and guidance for the baseline 

risk assessment for the Phase II parcels. The 

environmental condition of the groundwater below 

the Phase II parcels is expected to improve based on 

the actions planned or in progress at the other OUs. 

SECTION 8 

REMEDIAL ACTION OBJECTIVES 

The land encompassing the Phase II parcels is to be 

transferred to LIDA with deed restrictions to limit 

the use of and contact with groundwater, to prevent 

exposure to groundwater at all of the parcels, and to 

limit the Gate 1 Guardhouse, Building 511, area to 

commercial/industrial use. These restrictions are 

being put in place to protect people from exposure 

to contaminated groundwater and the vapors that 

emanate from the groundwater, and to prevent 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

O:\02281016.008\PHASE II\ROD\ROD_MAY 30.DOC FINAL 26 

exposure to soils at the Gate 1 Guardhouse area 

should it be used for unrestricted purposes (e.g., 

residential or daycare). Therefore, the development 

of remedial action objectives was focused on 

protection of human health and the environment, 

and placing restrictions on preventing the use of the 

property for unauthorized purposes. The following 

remedial action objectives were identified for the 

Phase II parcels: 

!" Protect human health and the environment. 

!" Comply with all applicable or relevant and 

appropriate Federal and state environmental 

laws and regulations (ARARs). 

!" Prevent direct contact and ingestion of soil 

under residential use scenarios at Gate 1 

Guardhouse. 

!" Prevent exposure to groundwater (including 

inhalation of groundwater vapors). 

!" Take appropriate legal measures to ensure 

proper enforcement of site restrictions. 

!" Provide a suitable remedial alternative such that 

the land transfer recipient can have beneficial 

use of the property with minimal limitations. 

SECTION 9 

DESCRIPTION OF ALTERNATIVES 

CERCLA requires that each selected site remedy be 

protective of human health and the environment, be 

cost effective, comply with all applicable or relevant 

and appropriate Federal and state environmental 

laws and regulations (ARARs), and use permanent 

solutions and alternative treatment technologies and 

resource recovery alternatives to the maximum 

extent practicable. In addition, the statute includes a 

preference for the use of treatment as a principal 

element for the reduction of toxicity, mobility, or 

volume of the hazardous substances. 

A treatment alternative has not been included for the 

Phase II parcels because EPA generally does not 

expect to use treatment technology where, as here, 

contamination in soil exists at low concentrations; 

the contamination is neither highly toxic nor highly 

mobile; and the risks to humans from the soil are 

within acceptable limits if the property is used for 

commercial/industrial purposes. Based on the 

current conditions as discussed in the summary of 

site risks, the soils in the parcels to be transferred do 

not pose a threat to human health and the 

environment. Therefore, the soils do not require 

treatment, and the soils at the Gate 1 Guardhouse do 

not require treatment if the future use of the 

property is limited to the intended use. Final 

groundwater remedial actions will be addressed in 

the future. The selected interim remedy for 

groundwater beneath the Phase II parcels is 

protective of human health and the environment in 

the short term and is intended to provide adequate 

protection until a final groundwater remedy is 

selected. 

Remedial alternatives for the Phase II parcels were 

developed to meet the remedial action objectives. 

The public needs to be protected from consuming or 

coming into direct contact with contaminated 

groundwater beneath the Phase II parcels. The 

public also needs to be protected from inhaling 

vapors that may enter a building or work area from 

the contaminated groundwater below the parcels, 

when the bottom floor of the building or bottom of a 

work area, such as a trench, is within 3 ft of the 

water table. 

Therefore, a remedial alternative was developed to 

prevent consumption of groundwater, direct contact 

with groundwater, and working within 3 ft of the 

water table. 

As noted above, soil at the Gate 1 Guardhouse 

contains low levels of organic compounds and 

metals. As long as the parcel is used for 

industrial/commercial purposes, and not residential 

purposes, no remedial action is necessary to protect 

human health or the environment from exposure to 

soil at the Gate 1 Guardhouse. Therefore, a remedial 

alternative was developed to ensure that the Gate 1 

Guardhouse will continue to be used for commercial 

or industrial purposes in the future, and to prevent 

unrestricted (e.g., residential or daycare) use of the 

area. 

Finally, as noted above, no remedial action is 

necessary for soil at any of the remaining Phase II 

parcels. The soils in these parcels are suitable for 

unrestricted use. Therefore, no remedial alternative 

was developed for soil at any Phase II parcel, except 

the Gate 1 Guardhouse. 

In addition, a no action alternative was included as a 

baseline alternative, as required by CERCLA, 

against which the other alternatives may be 

compared. 

Based on this information, the Army has developed 

the following two alternatives: 

!" Alternative 1: No Action 

!" Alternative 2: Institutional Controls 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

O:\02281016.008\PHASE II\ROD\ROD_MAY 30.DOC FINAL 27 

These alternatives are discussed in the following 

subsections. The evaluation of the alternatives 

against the nine CERCLA-mandated criteria is 

presented in Section 10. 

ALTERNATIVE 1: NO ACTION 

(All costs are present worth costs calculated based 

on an annual discount rate of 2.5%.) 

Capital Cost: $0

Operation and Maintenance Costs: 

5-Year CERCLA Review 

(for cost comparison purposes, 

cost for years 5 and 10) $41,630 

Total Present Worth Cost 

(including administrative, overhead, 

and contingency costs) $54,120

CERCLA guidance requires that the no-action 

alternative be considered as a baseline for 

comparison of other alternatives. No remedial 

actions would be implemented under this 

technology. The present worth cost is based on two 

5-year performance evaluation reviews/reports. 

ALTERNATIVE 2: INSTITUTIONAL 

CONTROLS 

(All costs are present worth costs calculated based 

on an annual discount rate of 2.5%.) 

Capital Cost: 

 Administrative costs for deed 

restrictions, and installation of 

monitoring wells and remote control 

groundwater monitoring equipment 

to monitor groundwater levels $137,500 

Operation and Maintenance Costs: 

 Maintenance of institutional controls 

including: maintenance of remote 

control groundwater level 

monitoring equipment (data loggers); 

groundwater monitoring; inspection; 

maintaining deed restrictions (for 

cost comparison purposes, cost 

annually for 30 years); and report 

preparation (for cost comparison 

purposes, cost annually, for 10 years) 

$180,270 

5-Year CERCLA Review 

(for cost comparison purposes, cost for 

years 5 and 10; it is anticipated that 

beyond year 10, the 5-year review will 

be included as part of the groundwater 

5-year review process) $41,630

Total Operation and Maintenance Costs: $221,900

Total Present Worth Cost 

(including administrative, overhead, 

and contingency costs) $467,200 

This alternative involves the use of institutional 

controls. The present worth cost is based on two 5-

year performance evaluation reviews/reports and 10 

years of operation and maintenance costs, including 

inspections. Institutional controls are nonengineered instruments, such as administrative or 

legal controls, that minimize the potential for human 

exposure to contamination by limiting land or 

resource use. Initially, the institutional controls to 

prohibit activities that would result in any exposure 

to the contaminants in the groundwater and prohibit 

nonindustrial use of the Gate 1 Guardhouse area will 

become part of LEAD policy via an amendment to 

the LEAD Master Plan. At the time of the property 

transfer, the institutional controls will take the form 

of deed restrictions to protect human health and the 

environment by: 

!" Restricting the Gate 1 Guardhouse, Building 511, 

area to commercial/industrial use (e.g., no 

residential or daycare use allowed). 

!" Prohibiting soil excavation, digging, drilling, or 

other disturbance of soil activities below a depth 

of 3 ft above the water table (a.k.a. 3-ft buffer 

zone) without the prior approval of the Army.*

!" Prohibiting access to or use of the groundwater 

underlying the property without the prior 

approval of the Army, PADEP, and EPA. 

!" Prohibiting construction of any subsurface 

structure for human occupation without the 

prior approval of the Army, PADEP, and EPA. 

The specific deed restrictions will be coordinated 

with the regulators and the public as part of the 

Finding of Suitability to Transfer for the Phase II 

parcels. The deed containing these restrictions will 

be recorded at the Franklin County Courthouse, 

 

*

Because the groundwater elevations vary at LEAD, the 

permissible soil disturbance/construction depth needs to be 

determined on a parcel-by-parcel basis. The information 

necessary for land transfer recipients to make this determination 

and monitor wells that should be used to measure depth to 

groundwater are provided in Attachment 3.
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O:\02281016.008\PHASE II\ROD\ROD_MAY 30.DOC FINAL 28 

Recorder of Deeds Office within 30 days following 

the transfer of the property to LIDA. 

An agreement among the Army, EPA, and PADEP 

to implement and maintain the institutional controls 

will be contained in a “Land Use Control Assurance 

Plan,” which will be executed prior to transfer of the 

Phase II parcels. The site-specific plan to implement 

and maintain the institutional controls will be 

contained in a “Land Use Control Implementation 

Plan,” which will be prepared as an attachment to 

the Land Use Control Assurance Plan. The Army 

will be responsible for implementing and 

maintaining the institutional controls. The Army, 

with EPA and PADEP approval, may arrange with 

other entities such as LIDA to maintain land use 

controls. The Army remains ultimately responsible 

for protecting human health and the environment 

through this remedy. 

SECTION 10 

SUMMARY OF COMPARATIVE 

ANALYSIS OF ALTERNATIVES 

During the detailed evaluation of remedial 

alternatives, each alternative is assessed against nine 

evaluation criteria as outlined in the National Oil 

and Hazardous Substances Pollution Contingency 

Plan (NCP). These criteria fall into three broad 

categories: threshold criteria, primary balancing 

criteria, and modifying criteria. The evaluation 

criteria within each of these categories are as follows: 

!" Threshold Criteria: To be considered for remedy 

selection, an alternative must meet the following 

two threshold criteria: 

1. Overall protection of human health and the 

environment. 

2. Compliance with ARARs. 

!" Primary Balancing Criteria: Primary balancing 

criteria are used to determine which alternative 

provides the best combination of attributes: 

3. Long-term effectiveness and permanence. 

4. Reduction in toxicity, mobility, or volume 

through treatment. 

5. Implementability. 

6. Short-term effectiveness. 

7. Cost. 

!" Modifying Criteria: The preferred alternative is 

evaluated further against the following two 

modifying criteria: 

8. State acceptance. 

9. Community acceptance. 

Evaluation of the alternatives against the nine 

criteria is presented in the following subsections. 

THRESHOLD CRITERIA 

1. Overall Protection of Human Health and 

the Environment 

Alternative 2 is more protective of human health 

than Alternative 1. Alternative 2 uses administrative 

and legal controls to reduce the risk of being 

exposed to potentially contaminated soils and 

preventing exposure to groundwater. Alternative 1, 

by contrast, would do nothing to reduce potential 

risks. The two alternatives are equivalent in 

protecting the environment. 

2. Compliance with ARARs 

Both alternatives comply with all applicable or 

relevant and appropriate Federal and state 

environmental laws and regulations (ARARs) for 

soil. 

Chemical-Specific ARARs: The ARARs for soil 

are the following: 

!" Commonwealth of Pennsylvania, Rules and 

Regulations, Title 25 — Environmental 

Protection, Environmental Quality Board [25 PA 

Code, Chapter 250], Administration of the Land 

Recycling Program (Act 2): Table 3A, MediumSpecific Concentrations for Organic Regulated 

Substances in Soil, Direct Contact Numeric 

Values, Residential Values (0-15 feet) for the 

following chemicals: acetone, benzene, 

acenaphthene, benz(a)anthracene, 

benzo(b)fluoranthene, fluorene, and 

naphthalene; and Table 4A, Inorganic 

Regulated Substances in Soil, Residential Values 

(0-15 feet) for the following chemicals: 

aluminum, arsenic, barium, chromium, cobalt, 

iron, lead, manganese, nickel, selenium, 

thallium, vanadium, and zinc. Source: 

Pennsylvania Bulletin, Volume 27, Number 33, 16 

August 1997. 

!" U.S. Environmental Protection Agency, 40 Code 

of Federal Regulations, Part 761, Disposal of 

Polychlorinated Biphenyls, Final Rule under the 

Toxic Substances Control Act (TSCA), Section 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

O:\02281016.008\PHASE II\ROD\ROD_MAY 30.DOC FINAL 29 

761.61(a)(4)(i)(A), Cleanup Levels for Bulk PCB 

Remediation Waste, High Occupancy Areas: 

action is required for concentrations greater than 

1 part per million (equivalent to milligrams per 

kilogram for soil or solid materials). Source: 

Federal Register, Volume 63, Number 124, 29 June 

1998, pp 35383-35474). 

The ARARs for soil are met because hazardous 

substances found in soils in the Phase II parcels are 

at concentrations less than the values listed in the 

citations referenced above. 

Neither alternative complies with the ARARs for 

groundwater. However, the groundwater remedies 

discussed here are merely interim remedies. EPA 

does not require interim remedies to comply with 

ARARs where, as here, a final remedy is under 

development. Thus, groundwater ARARs are not 

identified here. ARARs for groundwater will be 

discussed in more detail in the ROD for the final 

remedy for groundwater, which will be required to 

comply with all ARARs or to justify a waiver of 

ARARs. 

Action-Specific and Location-Specific 

ARARs: Neither alternative would be subject to 

action-specific ARARs. In addition, no locationspecific ARARs were identified for the Phase II 

parcels. 

PRIMARY BALANCING CRITERIA 

3. Long-Term Effectiveness and 

Permanence 

Alternative 2 is more effective in the long term 

than Alternative 1. 

Implementation of the no-action alternative could be 

effective and permanent in the long term if the soil 

alone is considered because there is no 

contamination present, with the exception of the 

Gate 1 Guardhouse. There is acceptable risk 

associated with the soils at the Gate 1 Guardhouse, 

assuming continued industrial use. However, in the 

long term, other tenants/owners of the property 

could be exposed to contamination through 

exposure to groundwater, excavation, and contact 

with the groundwater or volatilization of VOCs from 

groundwater through soil (if the 3-ft buffer zone is 

not maintained). In addition, the Gate 1 Guardhouse 

property could be used for nonindustrial or 

noncommercial purposes, possibly increasing the 

risk to human health. Therefore, Alternative 1 does 

not meet the requirements for long-term 

effectiveness and permanence. 

For Alternative 2, the long-term effectiveness of the 

institutional controls will be contingent upon 

enforcement of restrictions for use of the property to 

prevent groundwater exposure (including inhalation 

of vapors if the 3-ft buffer zone is not maintained) 

and to restrict the Gate 1 Guardhouse site to 

industrial/commercial use. The restrictions will be 

initially enforced by the Army through the LEAD 

Master Plan, and after transfer, through enforcement 

of the environmental deed restrictions. 

Implementation of this alternative would maintain 

the industrial/commercial (intended future) use of 

the Gate 1 Guardhouse property and reduce the 

future risk of exposure to groundwater by the 

development and enforcement of environmental 

deed restrictions. Because these restrictions would 

become a permanent part of the real estate 

documentation and would be required to be 

included in any subsequent sales, transfers, and/or 

lease agreements, this alternative would be a longterm and permanent remedial action. In addition, a 

Land Use Control Assurance Plan (formerly referred 

to as Memorandum of Agreement ) for institutional 

controls will be in-place at the time of property 

transfer. This Land Use Control Assurance Plan, 

along with the Land Use Control Implementation 

Plan (which will be implemented as part of the Land 

Use Control Assurance Plan) will provide a longterm mechanism to ensure that the institutional 

controls are enforced in the future. 

4. Reduction in Toxicity, Mobility, or 

Volume 

Neither alternative results in a change in toxicity, 

mobility, or volume because the alternatives do not 

involve physical remedial actions. Soil in the Phase II 

parcels, except for the Gate 1 Guardhouse, can be 

used for any purpose, including residential uses, 

without being treated or otherwise remediated. Soil 

at the Gate 1 Guardhouse can be used for 

commercial/industrial purposes without being 

treated or otherwise remediated. Therefore, 

treatment is unnecessary to protect human health or 

the environment from soil in the Phase II parcels as 

long as the Gate 1 Guardhouse is used only for 

industrial/commercial uses (i.e., no residential or 

daycare use) in the future. 

Because groundwater contamination and the 

groundwater source areas are being addressed 

under separate OUs, the statutory preference for 

remedies that employ treatment that reduces the 

toxicity, mobility, or volume as a principal element 

will be addressed by the final groundwater 

response. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

O:\02281016.008\PHASE II\ROD\ROD_MAY 30.DOC FINAL 30 

5. Implementability 

Both alternatives meet this requirement. 

Under Alternative 1, the no-action alternative, there 

are no measures to implement. 

Alternative 2 can be implemented easily. The shortterm implementation of the preferred alternative 

would involve amending the LEAD Master Plan to 

include the institutional controls that are already inplace informally at the Depot. Once the amendment 

is added, appropriate directorates at LEAD (the 

environmental division, Public Works, security, or as 

otherwise designated by the Army) would be 

provided with a copy and with the enforcement 

action chain-of-command for infractions. 

Concurrent with this activity, the Department of the 

Army will be developing deed restrictions for the 

Phase II parcels. These deed restrictions will be 

coordinated with the regulators and the public as 

part of the Finding of Suitability to Transfer for the 

Phase II parcels. The site-specific plan to implement 

and maintain the institutional controls will be 

contained in the Land Use Control Implementation 

Plan, which will be prepared as an attachment to the 

Land Use Control Assurance Plan. Both the Land 

Use Control Assurance Plan and Land Use Control 

Implementation Plan have been effectively 

implemented at other facilities. 

6. Short-Term Effectiveness 

Alternative 1 would not meet the requirements for 

short-term effectiveness, whereas Alternative 2 

would meet the requirements. Currently, LEAD 

prohibits the use of or contact with groundwater. 

After the property is transferred to a private entity, 

there would be no legal provision under Alternative 

1 to keep future land users from being exposed to 

the contaminated groundwater, or from using the 

Gate 1 Guardhouse property for nonindustrial or 

noncommercial purposes. 

Under Alternative 2, institutional controls would be 

implemented to mitigate risk due to exposure to 

groundwater, and prevent uses other than 

industrial/commercial for the Gate 1 Guardhouse 

property. The Army is currently restricting use of 

groundwater at LEAD so part of the remedy is 

already in-place. This alternative would be effective 

in the short term because the Army would formally 

document the requirements of the institutional 

controls by amending the LEAD Master Plan. This 

will provide effectiveness from the finalization of the 

ROD until the date of transfer. The environmental 

deed restrictions would be in place immediately 

after the date of transfer (the deed will be recorded 

within 30 days of the transfer date). Those 

restrictions would be maintained as directed in the 

Land Use Control Assurance Plan. 

7. Cost 

For comparison purposes only, Alternative 1 has the 

estimated costs for two 5-year reviews associated 

with its implementation. The costs presented for 

Alternative 2 are estimated, and may vary 

depending on the number of parcels that are 

transferred via separate phases of land transfer. 

Alternative 2 is estimated to be more costly to 

implement ($467,200) than Alternative 1 ($54,120). 

MODIFYING CRITERIA 

8. State Acceptance 

PADEP, on behalf of the Commonwealth of 

Pennsylvania, concurs with the selected remedy. 

9. Community Acceptance 

The community does not object to the selected 

remedy. No written or verbal comments were 

received during the public comment period on the 

Proposed Plan. The public review and community 

involvement process is discussed in more detail in 

the Responsiveness Summary of this ROD. 

SECTION 11 

PRINCIPAL THREAT WASTE 

Principal threat wastes are “source materials” 

considered to be highly toxic or highly mobile that 

generally cannot be reliably contained, or would 

present a significant risk to human health or the 

environment should exposure occur. A source 

material is a material that includes or contains 

hazardous substances, pollutants, or contaminants 

that act as a reservoir for migration of contaminants 

to groundwater, surface water, or air, or acts as a 

source for direct exposure. Contaminated 

groundwater generally is not considered to be a 

source material; however, nonaqueous phase liquids 

in groundwater may be viewed as a source material. 

There are no principal threats associated with Phase 

II parcels under this response action because there 

are no contaminant sources present in the soil. 

Although the groundwater beneath the Phase II 

parcels is known to be or is potentially contaminated 

with VOCs above acceptable risk-based levels, a 

final remedy for groundwater contamination with 

VOCs is not within the confines of this ROD. 

However, to eliminate any potential risks posed by 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

O:\02281016.008\PHASE II\ROD\ROD_MAY 30.DOC FINAL 31 

groundwater, groundwater use restrictions are 

documented in this ROD as the interim action for 

groundwater beneath the Phase II parcels. Final 

actions for groundwater will be addressed 

separately in the groundwater operable units (PDO 

OU 2, SE OU 3, and SE OU 10). 

SECTION 12 

SELECTED REMEDY 

SUMMARY OF THE RATIONALE FOR THE 

SELECTED REMEDY 

Based on the requirements of CERCLA and the 

NCP, and on a detailed analysis of the response 

alternatives using the nine criteria (which includes 

public and state comments), the Army and EPA 

have selected Alternative 2 (institutional controls) as 

the remedy for this site. 

Institutional controls was selected over the no action 

alternative because it is the only alternative of the 

two that achieves the remedial action objectives, 

thereby achieving long-term protection of human 

health and the environment under the current and 

intended future use of the property. The selected 

alternative, institutional controls, will accomplish 

the following: 

!"Reduce risks to human health by preventing 

exposure to contaminated groundwater. 

!"Be easy to implement, at a cost that is not 

prohibitive. 

!"Address risk while making the property 

available quickly for public reuse and benefit. 

DESCRIPTION OF THE SELECTED REMEDY 

The selected alternative, institutional controls, will 

include the following components: 

!"Restrict the Gate 1 Guardhouse, Building 511, 

area to commercial/industrial use (e.g., no 

residential or daycare use allowed). 

!"Prohibit soil excavation, digging, drilling, or 

other disturbance of soil activities below a depth 

of 3 ft above the water table (a.k.a. 3-ft buffer 

zone) without the prior approval of the Army.*

 

*

Because the groundwater elevations vary at LEAD, the 

permissible soil disturbance/construction depth needs to be 

determined on a parcel-by-parcel basis. The information 

necessary for land transfer recipients to make this determination 

!"Prohibit access or use of the groundwater 

underlying the property without the prior 

approval of the Army, PADEP, and EPA. 

!"Prohibit construction of any subsurface structure 

for human occupation without the prior 

approval of the Army, PADEP, and EPA. 

These restrictions will be instituted through an 

amendment of LEAD’s Master Plan for the Phase II 

parcels to reflect these controls until the date of 

transfer. At the time the property is transferred, the 

restrictions will be implemented through the use of 

deed restrictions, which will be recorded within 30 

days of the property transfer date. In addition, upon 

transfer of the property, the Army, in consultation 

with EPA and PADEP, will establish periodic 

inspection procedures as described in the Land Use 

Control Assurance Plan and the Land Use Control 

Implementation Plan to ensure adherence to the 

institutional controls. 

By means of the Land Use Control Assurance Plan 

(which is a Memorandum of Agreement with EPA 

and PADEP), LEAD, on behalf of the Department of 

the Army, will agree to implement Depotwide, 

certain periodic site inspection, condition 

certification, and agency notification procedures 

designed to ensure the maintenance by Army 

personnel (or other approved designee) of any sitespecific land use controls deemed necessary for 

future protection of human health and the 

environment. A fundamental premise underlying 

execution of the agreement will be that through the 

Army’s substantial good-faith compliance with the 

procedures called for therein, reasonable assurances 

would be provided to EPA and PADEP as to the 

permanency of those remedies that included the use 

of specific land use controls. The Army, with EPA 

and PADEP approval, may arrange with other 

entities such as LIDA to maintain land use controls. 

The Army remains ultimately responsible for 

protecting human health and the environment 

through this remedy. 

Although the terms and conditions that will be 

included in the Land Use Control Assurance Plan 

are not specifically incorporated or made 

enforceable herein by reference, it is understood and 

agreed by the Army, EPA, and PADEP that the 

contemplated permanence of the remedy reflected 

herein will be dependent on the Army’s substantial 

good-faith compliance with the specific land use 

control maintenance commitments that will be 

 

and monitor wells that should be used to measure depth to 

groundwater are provided in Attachment 3.
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

O:\02281016.008\PHASE II\ROD\ROD_MAY 30.DOC FINAL 32 

reflected therein. Should such compliance not occur 

or should the Land Use Control Assurance Plan be 

terminated, it is understood that the protectiveness 

of the remedy may be reconsidered and that 

additional measures may need to be taken to 

adequately ensure necessary future protection of 

human health and the environment. 

SUMMARY OF THE ESTIMATED REMEDY 

COSTS 

A summary of the major components of the cost 

estimate is presented in Section 9. The information in 

this cost estimate summary is based on the best 

available information regarding the anticipated 

scope of the remedial alternative. Changes in the 

cost elements are likely to occur as a result of new 

information and data collected during the 

engineering design of the remedial alternative. 

Major changes may be documented in the form of a 

memorandum in the Administrative Record file, an 

Explanation of Significant Differences, or a ROD 

amendment. This is an order-of-magnitude 

engineering cost estimate that is expected to be 

within +50% to –30% of the actual project cost. The 

total present worth cost of the selected remedy is 

estimated at $467,200. 

EXPECTED OUTCOMES OF THE SELECTED 

REMEDY 

The expected outcomes consist of use restrictions 

enforced through legal restrictions. These 

restrictions, as summarized in the following 

paragraphs, will be written in the property deed as 

the Environmental Deed Provisions. The outcomes 

are summarized as follows: 

!"All Phase II parcels (except the Gate 1 

Guardhouse) are protective of human health and 

the environment when used for residential, 

daycare, or any other purposes, as long as the 

prohibitions and restrictions on excavation, 

subsurface construction, and groundwater use 

listed below are complied with. 

!"The Gate 1 Guardhouse, Building 511, area 

(shown on the map in Figure 4) will be available 

only for commercial and industrial use activities 

(e.g., no residential or daycare allowed) as long 

as the prohibitions and restrictions on 

excavation, construction of subsurface 

structures, and groundwater use listed below 

are complied with. 

!"Soil may not be excavated within a 3-ft depth to 

the water table without the prior approval of the 

Army. 

!"Construction of any subsurface structure for 

human occupation may not be conducted 

without the prior approval of the Army, PADEP, 

and EPA. 

!"Groundwater underlying the Phase II parcels 

may not be used for any purpose without the 

prior written approval of the Army, PADEP, 

and EPA. 

PERFORMANCE STANDARDS OF THE 

SELECTED REMEDY 

The selected remedy does not employ treatment of 

soil. The institutional controls employed in the 

selected remedy are well-known legal procedures 

used in real estate property transfers. 

The Base Master Plan will be amended to fully and 

properly implement the selected remedy as specified 

in the Land Use Control Implementation Plan. The 

changes to the Base Master Plan will be 

communicated to LEAD’s Environmental Division, 

Public Works Division, and Security Division. The 

enforcement of the actions related to the selected 

remedy will be implemented as specified in the 

Land Use Control Implementation Plan. 

A deed that fully and properly implements the 

selected remedy will be properly recorded with the 

Franklin County Courthouse Recorder of Deeds 

Office within 30 days after the deed is fully executed 

by LIDA and the Army (the United States of 

America acting by and through the Secretary of the 

Army). 

SECTION 13 

STATUTORY DETERMINATIONS 

Under CERCLA Section 121, the Army and EPA 

must select remedies that are protective of human 

health and the environment, comply with ARARs 

(unless a statutory waiver is justified), are costeffective, and utilize permanent solutions and 

alternative treatment technologies or resource 

recovery technologies to the maximum extent 

practicable. In addition, CERCLA includes a 

preference for remedies that employ treatment that 

permanently and significantly reduces the volume, 

toxicity, or mobility of hazardous wastes as their 

principal element. The following subsections discuss 

the remedy in light of these statutory requirements. 
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O:\02281016.008\PHASE II\ROD\ROD_MAY 30.DOC FINAL 33 

PROTECTION OF HUMAN HEALTH AND THE 

ENVIRONMENT 

The selected remedy will be protective of human 

health and the environment. The institutional 

controls will ensure that an acceptable risk level is 

maintained for both carcinogenic and 

noncarcinogenic risks as described in Section 7. 

COMPLIANCE WITH APPLICABLE OR 

RELEVANT AND APPROPRIATE 

REQUIREMENTS 

The selected final remedy with regard to soils will be 

in full compliance with all ARARs. The ARARs for 

soil are the following: 

!"Commonwealth of Pennsylvania, Rules and 

Regulations, Title 25 — Environmental 

Protection, Environmental Quality Board [25 PA 

Code, Chapter 250], Administration of the Land 

Recycling Program (Act 2): Table 3A, MediumSpecific Concentrations for Organic Regulated 

Substances in Soil, Direct Contact Numeric 

Values, Residential Values (0-15 feet) for the 

following chemicals: acetone, benzene, 

acenaphthene, benz(a)anthracene, 

benzo(b)fluoranthene, fluorene, and 

naphthalene; and Table 4A, Inorganic Regulated 

Substances in Soil, Residential Values (0-15 feet) 

for the following chemicals: aluminum, arsenic, 

barium, chromium, cobalt, iron, lead, 

manganese, nickel, selenium, thallium, 

vanadium, and zinc. Source: Pennsylvania 

Bulletin, Volume 27, Number 33, 16 August 1997. 

!"U.S. Environmental Protection Agency, 40 Code 

of Federal Regulations, Part 761, Disposal of 

Polychlorinated Biphenyls, Final Rule under the 

Toxic Substances Control Act (TSCA), Section 

761.61(a)(4)(i)(A), Cleanup Levels for Bulk PCB 

Remediation Waste, High Occupancy Areas: 

action is required for concentrations greater than 

1 part per million (equivalent to milligrams per 

kilogram for soil or solid materials). Source: 

Federal Register, Volume 63, Number 124, 29 June 

1998, pp 35383-35474). 

The ARARs for soil are met because hazardous 

substances found in soils in the Phase II parcels are 

at concentrations less than the values listed in the 

citations referenced. 

Because the remedy regarding groundwater is an 

interim measure, final response objectives and 

ARARs are not identified here. Groundwater 

ARARs, including providing a detailed list of 

current groundwater ARARs, will be addressed in 

subsequent PDO OU 2, SE OU 3, and SE OU 10 

RODs. 

COST EFFECTIVENESS 

The selected remedy, institutional controls, was 

chosen because it provides the best balance among 

criteria used to evaluate the alternatives considered 

in the detailed analysis. The alternative was found to 

achieve both adequate protection of human health 

and the environment, and to meet the statutory 

requirements of Section 121 of CERCLA. The 

selected remedy was found to be cost-effective. The 

cost of Alternative 2 has been estimated to be 

$467,200. 

UTILIZATION OF PERMANENT SOLUTIONS 

AND ALTERNATIVE TREATMENT 

TECHNOLOGIES OR RESOURCE 

RECOVERY TECHNOLOGIES TO THE 

MAXIMUM EXTENT PRACTICABLE 

EPA and the Army have determined that the 

selected remedy represents the maximum extent to 

which permanent solutions and treatment 

technologies can be utilized in a cost-effective and 

timely manner for the Phase II parcels. The 

groundwater portion of this action, however, is 

interim and is not intended to utilize permanent 

solutions and alternative treatment (or resource 

recovery) technologies to the maximum extent 

practicable. 

PREFERENCE FOR TREATMENT AS A 

PRINCIPAL ELEMENT 

The selected remedy for the Phase II parcels, 

institutional controls, does not satisfy the statutory 

preference for treatment as a principal element of 

the remedy. With respect to the soils, the selected 

remedy does not meet the statutory preference for 

treatment as a principal element because EPA 

generally does not expect to use treatment 

technology where, as here, contamination in soil 

exists at low concentrations; the contamination is 

neither highly toxic nor highly mobile; and the risks 

to humans from the soil are within acceptable limits 

if the property is used for commercial/industrial 

purposes (Gate 1 Guardhouse). 

As for the groundwater, because the selected action 

does not constitute a final remedy, the statutory 

preference for remedies that employ treatment that 

reduces toxicity, mobility, or volume as a principal 

element will be addressed by the final groundwater 

response action and in subsequent RODs. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

O:\02281016.008\PHASE II\ROD\ROD_MAY 30.DOC FINAL 34 

SECTION 14 

DOCUMENTATION OF 

SIGNIFICANT CHANGES

There were no significant changes made in this ROD 

for the selected remedy identified in the Proposed 

Plan. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

MK01|O:\02281016.008\PHASE II\ROD\ROD_RS-GLOSSARY FINAL

G-1

GLOSSARY OF TERMS

Administrative Record A file that is maintained, and contains all the information used by the lead 

agency (Letterkenny Army Depot) to make its decision on the selection of a 

response action under CERCLA. This file is to be available for public review and 

a copy established at or near the site, usually at one of the information 

repositories (Coyle Free Library).

Applicable or Relevant and 

Appropriate Requirements 

(ARARs)

“Applicable requirements” are cleanup standards, standards of control, and 

other substantive requirements, criteria, or limitations promulgated under 

Federal environmental or state environmental or facility siting laws that 

specifically address a hazardous substance, pollutant, contaminant, remedial 

action, location, or other circumstance found at a CERCLA site. 

“Relevant and appropriate requirements” are cleanup standards, standards of 

control, and other substantive requirements, criteria, or limitations promulgated 

under Federal environmental or state environmental or facility siting laws that, 

while not "applicable" to a hazardous substance, pollutant, contaminant, 

remedial action, location, or other circumstance at a CERCLA site, address 

problems or situations sufficiently similar to those encountered at the CERCLA 

site that their use is well suited to the particular site. 

Base Realignment and Closure 

(BRAC)

The process by which the U.S. Department of Defense is “rightsizing.” As part of 

this procedure, excess infrastructure and property that are no longer needed to 

support the defense mission are being closed and/or realigned.

Commercial/Industrial Use As referenced in this Record of Decision document, means includes, but is not 

limited to, administrative/office space, manufacturing, warehousing, 

restaurants, hotels/motels, and retail activities. Under this definition residential 

and daycare use are prohibited.

Community Use As referenced in this ROD, means use as educational facilities for children from 

6 years old or older, occasional use retreat facilities for educational purposes, 

nature walk areas, fitness trails, office space to support educational functions, 

indoor and outdoor sporting activities, horticulture programs (indoor and 

outdoor), and livestock pasture (residential use prohibited).

Comprehensive 

Environmental Response, 

Compensation, and Liability 

Act (CERCLA)

A Federal law passed in 1980 and modified in 1986 by the Superfund 

Amendments and Reauthorization Act (SARA) to investigate and clean up 

abandoned and uncontrolled hazardous waste sites. U.S. Department of 

Defense cleanups are funded by the defense budget. 

Environmental Baseline 

Survey

A detailed search and review of available information (Army, Federal, state, and 

local), analysis of aerial photographs, interviews with current and/or former 

employees, review of ongoing response actions, visual inspections, and 

identification of sources of contamination to determine the environmental 

condition of the BRAC property.
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MK01|O:\02281016.008\PHASE II\ROD\ROD_RS-GLOSSARY FINAL

G-2

GLOSSARY OF TERMS

(Continued)

Feasibility Study or Focused 

Feasibility Study

Analysis of the practicability of a proposal; e.g., a description and 

analysis/evaluation of the potential cleanup alternatives for a site or 

alternatives for a CERCLA site. The feasibility study usually recommends 

selection of a viable cost-effective alternative. It usually starts as soon as the 

remedial investigation is underway. Together they are commonly referred to as 

the “RI/FS.” The term can apply to a variety of proposed corrective or regulatory 

actions. A focused feasibility study, usually referred to as an FFS, is a feasibility 

study where the technologies or alternatives evaluated have already been 

narrowed-down to a smaller number, usually because previous research such as 

“pilot studies” or “bench-scale” studies have been performed. A pilot study or 

bench-scale study refers to a test where a treatment alternative is performed on a 

small scale to see if it is effective for the contaminants at a site. Bench-scale 

studies are normally performed in a laboratory, and the pilot-scale studies are 

performed at the site or at a larger setting than the laboratory.

Information Repository A file containing current information, technical reports, reference documents, 

and other information on a CERCLA site. The information repository includes 

the Administrative Record file. This is maintained by LEAD.

National Oil and Hazardous 

Substances Pollution 

Contingency Plan (NCP)

The Federal regulation that guides the CERCLA program. The NCP was revised 

in February 1990.

National Priorities List (NPL) EPA’s list of uncontrolled or abandoned hazardous waste sites that are 

priorities for long-term remedial evaluation and response.

Operable Unit Term for each of a number of separate activities or actions that each comprises 

an incremental step toward comprehensively addressing environmental 

problems at a CERCLA site. The cleanup of a site can be divided into a number 

of operable units, depending on the complexity of the problems associated with 

the site. Operable units may, for example, address geographical portions of a site 

or specific site problems, such as groundwater contamination.

PCBs PCBs are polychlorinated biphenyls. PCBs belong to a family of manmade 

chlorinated organic compounds (chemicals containing carbon, hydrogen, and 

chlorine) used since 1926 in electrical transformers as insulators and coolants, 

and in lubricants, carbonless copy paper, adhesives, and caulking compounds. 

PCBs are produced in certain combustion processes. PCBs were marketed as 

various mixtures under different trade names; the most common name for PCBs 

is Aroclors. The manufacture of PCBs was discontinued in the United States in 

1977.

Pilot Study A pilot study or bench-scale study refers to a test where a treatment alternative is 

performed on a small scale to see if it is effective for the contaminants at a site. 

Bench-scale studies are normally performed in a laboratory, and the pilot-scale 

studies are performed at the site or at a larger setting than the laboratory.

Proposed Plan A document that describes, for public review and comment, the preferred 

cleanup strategy, the rationale for the preference, and the alternatives presented 

in a detailed analysis of the remedial investigation/feasibility study.
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MK01|O:\02281016.008\PHASE II\ROD\ROD_RS-GLOSSARY FINAL

G-3

GLOSSARY OF TERMS

(Continued)

Record of Decision (ROD) A public document that explains which cleanup alternative will be used at an 

NPL site. The ROD is based on information and technical analysis generated 

during the remedial investigation/feasibility study and consideration of public 

comments and community concerns.

Remedial Investigation An in-depth study designated to gather the data necessary to determine the 

nature and extent of contamination at a CERCLA site (by sampling and analysis 

of soil, groundwater, or other media); establish criteria for cleaning up the site; 

identify alternatives for remedial actions; and support the technical cost 

analyses of the alternatives. The remedial investigation is usually conducted 

with the feasibility study. Together they are usually referred to as the “RI/FS.”

Residential Use As referenced in this ROD, means including, but not limited to, housing, daycare 

facilities, schools (excluding education and training programs for persons over 

18 years of age), assisted living facilities, and outdoor recreational activities. 

Unrestricted use (community and commercial/industrial included) is permitted 

under this definition.

Resource Conservation and 

Recovery Act (RCRA)

A Federal law that established a regulatory system to track hazardous wastes 

from their generation to disposal. The law (enacted in 1980) requires safe and 

secure procedures to be used in treating, transporting, storing, and disposing of 

hazardous wastes. RCRA is designed to prevent the creation of new, 

uncontrolled hazardous waste sites.

Risk Assessment Qualitative and quantitative evaluation of the risk posed to human health 

and/or the environment by the actual or potential presence and/or use of 

specific pollutants.

Semivolatile Organic 

Compounds

These are organic compounds that volatilize slowly at standard (i.e., room) 

temperature and pressure. An example is benzo(a)pyrene, which is one of the 

semivolatiles also referred to as a polyaromatic hydrocarbon.

Superfund Amendments and 

Reauthorization Act (SARA)

Modification to CERCLA enacted on 17 October 1986.

Toxic Substances Control Act This act was enacted by Congress in 1976 (effective 1 January 1977, 15 United 

States Code [U.S.C.] Section 601 et seq. and amended by Public Law 97-129 on 29 

December 1981) to protect human health and the environment from 

unreasonable risks of injury caused by the manufacture, processing, 

distribution, use, or disposal of chemical substances and mixtures.

Volatile Organic Compound An organic (carbon-containing) compound that evaporates (volatilizes) readily 

at room temperature. Examples of VOCs are trichloroethylene (TCE), and 

dichloroethene (DCE).
O:\02281016.008\PHASE II\ROD\ROD_RESPONSSUM MAY 17.DOC FINAL 1 

LETTERKENNY ARMY DEPOT 

PHASE II PARCELS 

CHAMBERSBURG, FRANKLIN COUNTY, PENNSYLVANIA 

RESPONSIVENESS SUMMARY 

JULY 2001 

SECTION 1

OVERVIEW 

Based on an assessment of site conditions and remedial 

alternatives, the U.S. Department of the Army (Army) 

and the U.S. Environmental Protection Agency (EPA) 

selected a remedy for the Phase II parcels at 

Letterkenny Army Depot (LEAD), Chambersburg, PA. 

The selected remedy addresses the threat associated 

with the contaminated groundwater beneath the 

parcels, and the potential threat associated with the 

soils at the Gate 1 Guardhouse area (Parcel 2R-80) in 

the event of nonindustrial land use. As specified in this 

Record of Decision (ROD), the remedy involves the 

implementation of deed restrictions and other 

institutional controls that will be protective of human 

health and the environment. 

Based on the fact that no comments were received 

during the public comment period, the residents and 

Letterkenny Industrial Development Authority (LIDA) 

appear not to object to the implementation of the 

institutional controls alternative for the Phase II 

parcels. No written or verbal comments were received 

during the public comment period on the Proposed 

Plan. 

SECTION 2

BACKGROUND ON COMMUNITY 

INVOLVEMENT 

CHRONOLOGY OF COMMUNITY 

INVOLVEMENT 

Community relations activities at LEAD to date have 

included public meetings; review and coordination 

meetings with Federal and state regulatory personnel; 

site visits; meetings with elected Federal, state, and 

local officials and with community groups; news 

releases to the local media; and direct contact with 

nearby property owners. 

Community interviews were conducted in 1988 as part 

of the process of developing the Public Involvement 

and Response Plan, which was published in 1990. At 

the time of the 1988 community interviews, the 

primary areas of concern to the community were the 

groundwater contamination problem and associated 

health and property value issues. 

LEAD has a Restoration Advisory Board, which began 

meeting in 1996 and focuses primarily on the 

restoration activities related to the Defense 

Environmental Restoration Account and Base 

Realignment and Closure (BRAC) actions. The 

Restoration Advisory Board replaced the Technical 

Review Committee, formed in 1988, which was the 

previous vehicle by which the community could 

provide comments and review progress on the 

environmental programs at LEAD. LEAD 

representatives attend Restoration Advisory Board 

meetings and Letterkenny Industrial Development 

Authority (LIDA) meetings (formerly the Franklin 

County Reuse Committee) and provide status updates 

on environmental activities at LEAD. 

Meetings with regulatory agency personnel have been 

conducted regularly and are held with representatives 

from LEAD, the U.S. Army Corps of Engineers, the 

Pennsylvania Department of Environmental Protection 

(PADEP), EPA Region III, Department of the Army, 

and the U.S. Army Aviation and Missile Command 

(which is a subordinate Command of the U.S. Army 

Materiel Command). Topics of discussion at these 

meetings generally include review of project status, 

review of new technical information, resolution of 

problem areas, and direction and schedule of further 

studies. In addition to the formal meetings, LEAD, the 

U.S. Army Corps of Engineers, PADEP, and EPA 

personnel maintain frequent telephone and E-mail 

contact on an as-needed basis. 

Site visits to LEAD have been made by representatives 

of the Restoration Advisory Board, the U.S. Army 

Corps of Engineers, PADEP, EPA Region III, and 

contractors. Numerous site visits by the regulatory 

agency representatives have promoted communication 

among LEAD, PADEP, and EPA. 

Periodically since June 1982, when the groundwater 

contamination problem was first identified, formal 
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news releases have been issued by LEAD concerning 

the groundwater issue and other sources of 

contamination. These news releases typically contain 

information on the initial phases of investigation 

and/or remedial work. Recently, much of the news 

coverage has concerned cleanup with regard to the 

BRAC parcels and the status of lease and transfer of 

the property. 

The residents in the vicinity of LEAD have generally 

reacted favorably to the efforts made by the Army with 

regard to the identification and cleanup programs 

underway and proposed. The off-post sampling of 

wells for potential groundwater contamination during 

the 1980s made nearby residents more aware of the 

contamination problems existing at LEAD. However, 

the proactive approach by the Army to identify 

potential problems and mitigate exposure (by 

providing connections to a public drinking water 

source for residents whose wells had potential or 

known contamination) was received favorably. 

KEY COMMUNITY CONCERNS 

The community is greatly concerned about the 

CERCLA sites and LEAD over the long term. 

Community interviews were conducted on 26-28 June 

1997 at the Depot as part of the revised Community 

Relations Plan. Telephone interviews were conducted 

prior to and after the on-site interviews. Each interview 

participant was asked 37 questions. A total of 19 

individuals participated in the interviews: 2 Depot 

residents and 17 Chambersburg-area residents. Persons 

interviewed for the revised Community Relations Plan 

identified seven areas of concern. 

Cleanup Activities

Generally, the interviewees were pleased with the 

ongoing environmental cleanup activities. Several 

people noted that for the last 8 to 10 years, Depot staff 

have worked hard to solve environmental problems at 

the site. Some interviewees expressed concern that the 

cleanup activities were taking too long. The majority of 

interviewees agreed that the government is committed 

to cleaning up the hazardous wastes at LEAD. Most of 

the interviewees wanted to know the status of specific 

cleanup activities (e.g., data, results, costs, and 

schedule). One mentioned that some of the 

environmental reports were too technical to 

understand. 

Some wanted the government to finish the remedial 

process as quickly as possible, whereas others thought 

that the government should take the time needed to 

conduct a thorough remedial process. One individual 

believed that the Army’s environmental standards may 

not be as stringent as the public’s standards in the level 

of cleanup activities. 

Several expressed a concern to return areas to 

farmland use and to coordinate efforts to preserve 

existing farmland. A few residents noted that farmers 

do not seem to be concerned about contamination 

because farming activities continue on property 

adjacent to LEAD. 

Some were concerned that cleanup activities would 

continue after areas were open for public reuse. One 

resident said that $350 million was too much to pay for 

groundwater contamination cleanup on-site and that 

documentation of the historic value of a warehouse 

before tearing it down was “foolish.”

Reuse 

Noting the economic impact of having fewer civilian 

jobs with the realignment of LEAD, the majority of the 

interviewees have accepted LIDA’s reuse plan.

Some thought the reuse of areas of LEAD was a 

positive step in preserving farmland/agriculture and 

pristine areas of Franklin County.

Some thought the reuse plan was overly optimistic and 

that the public would have to pay for the reuse 

activities. Many interviewees were concerned about 

the feasibility of taking care of the reuse areas of 

LEAD. Many were concerned about the potential 

liability if additional Army-generated contamination is 

discovered in the reuse areas.

A few were concerned about the types of industry that 

may be brought in and the potential for recontaminating the site and creating noise or traffic 

problems. Some were concerned with how the Army 

will provide access to the reuse areas, grant public use 

of the reservoir, and share the Depot’s infrastructure 

(electricity, water, sewer, etc.). One person suggested 

that the state establish a low-level radioactive waste 

disposal facility as a reuse option at LEAD.

Contamination 

Several interviewees stated that the extent of 

contamination is unknown and that more 

contamination may be discovered. One said that the 

Army brought materials from across the country for 

disposal at the Depot. Another said that studies show 

that the contamination is spreading. Residents are 

concerned that the solvents in the groundwater and 

streams will directly affect the population. Several 

mentioned concerns about specific areas at the Depot:

!" Apartment complex (Kenny Gardens housing). 

!" Old quarry (Fagan’s Quarry). 
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!" Rocky Spring Lake. 

!" Mercury in the lake. 

!" Fire practice-training areas. 

!" Lead contamination at the ammunition detonation 

area. 

!" Discharge from LEAD (below Gate 6) into streams 

after a heavy rain. 

Air Quality 

A few residents said that the Army needs to address 

air quality in addition to soils and groundwater 

contamination.

Ammunition Detonation 

Many residents expressed concern about the 

ammunition detonation activities at the Depot. They 

said the Army sometimes conducts this activity on 

weekends during the noon hour. Some interviewees 

believe that the blasting is causing plaster to crack in 

homes adjacent to and about a mile from LEAD. One 

resident said that the impact of the detonations is 

worse for homes a greater distance from LEAD than 

the homes nearer the Depot. Several mentioned that 

contaminants must be released into the air as a result 

of the ammunition detonation. Residents voiced 

concern about noise, air quality, and dust control 

regarding the detonation activities.

Government 

Half of the interviewees said that the general public 

mistrusts Federal and state government agencies. One 

resident said, “No matter what an individual thinks, 

the government will do what they want and that the 

government does not think an individual is important 

to consider.” However, the majority of the interviewees 

believe that PADEP is the most credible government 

agency regarding environmental issues.

Army 

The majority of the interviewees believe that the Army 

is committed to cleaning up the contamination at 

LEAD. One resident was pleased that LEAD is a 

government site because the Army is obligated to clean 

up the site, whereas a commercial venture could opt to 

abandon a contaminated property. Some specific 

concerns include the following:

!" The Army is rushing to transfer areas to the public 

because of community pressure and could 

compromise environmental cleanup activities. 

!" The Army cannot meet the deadlines because of 

the holdup caused by complex environmental 

problems. 

!" Some individuals have reservations about some 

information received from LEAD and are 

concerned that they may not be getting all of the 

information. One individual participated in two 

tours of the facility and questioned the use and 

contents of a building with concertina wire. The 

question was not answered to the individual’s 

satisfaction; therefore, this person believes the 

Army is hiding something. 

!" There was a lack of response from the LEAD 

Public Affairs Officer when residents complained 

about the blasting and poor quality of the office’s 

answering machine (very short tape). 

Of the 19 interviewees, 18 said they had an 

understanding of the BRAC activities at LEAD. The 

majority of the interviewees were favorable toward the 

cleanup activities related to the BRAC parcels. In 

addition, the majority of the interviewees were 

supportive of LIDA’s reuse plan. Most individuals also 

were favorable toward the cooperation and interaction 

between the Army and LIDA in freeing the to-beexcessed parcels as soon as possible. 

SECTION 3

SUMMARY OF COMMENTS 

RECEIVED DURING THE PUBLIC 

COMMENT PERIOD AND AGENCY 

RESPONSES 

The public comment period on the Proposed Plan for 

the Phase II parcels was held from 20 February to 22 

March 2001. No comments were received during this 

time. On 22 February 2001, a public availability session 

was held at the Building 10, Letterkenny Great Room 

to present the Proposed Plan (in the form of a poster 

presentation) and to entertain questions and comments 

from the public. There were no questions and no 

comments were made during the public availability 

session. 
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ATTACHMENT 1

REFERENCES
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ATTACHMENT 1

REFERENCES

Acker, R.C. 1955. Water Supply from Wells for Letterkenny Ordnance Works. Letter Report to District 

Engineer, U.S. Army Corps of Engineers, Baltimore District.

Becher, A.E. and L.E. Taylor. 1982. Groundwater Resources in the Cumberland and Contiguous Valleys of Franklin 

County, Pennsylvania. Pennsylvania Geological Survey Water Resources Report 53. Harrisburg, PA.

Brooks (Brooks Petroleum Contracting Company). February 1991. Findings Report for Site Investigation 

of Tank Removals at Letterkenny Army Depot, Chambersburg, Pennsylvania, Buildings 425, 435, and 350.

Dames and Moore, Inc. 1993. Asbestos SurveyLetterkenny Army Depot.

EA (EA Engineering, Science, and Technology). 1991. Site Investigation, LEAD.

EPA, Army, and PADEP (U.S. Environmental Protection Agency Region IIII, U.S. Army, and 

Pennsylvania Department of Environmental Protection). 1989. Federal Facility Agreement Under 

CERCLA Section 120, In the Matter of the U.S. Army's Letterkenny Army Depot, Chambersburg 

Pennsylvania and Impacted Environs, Administrative Docket Number III-FCA-CERC-001. February 

1989.

EPA (U.S. Environmental Protection Agency). May 1995. CERCLA Remedy Selection Process. Directive 

9355.7-04. Office of Solid Waste and Emergency Response. 

EPSYS (Epsys Corporation). February 2001. Seasonally High Groundwater Determination for the Phase 2 

BRAC Parcels, Letterkenny Army Depot. Final Report.

ERM (Environmental Resources Management, Inc.). 1995. Letterkenny Army DepotSWMU Site

Investigation Follow-on Report, ELIN A009. January 1995.

ESE (Environmental Science & Engineering, Inc.). December 1987a. Remedial Investigation of the 

Southeastern Area at LEAD.

ESE (Environmental Science & Engineering, Inc.). January 1993a. Remedial Investigation of the Property 

Disposal Office Area at Letterkenny Army Depot. Final Report.

ESE (Environmental Science & Engineering, Inc.). June 1993b. Risk Assessment of the Property Disposal 

Office Area at Letterkenny Army Depot, Operable Units 1 and 2. Final Report.

ESE (Environmental Science & Engineering, Inc.). June 1993c. Remedial Investigation of the Southeastern 

Area at Letterkenny Army Depot. Final Report.

ESE (Environmental Science & Engineering, Inc.). July 1994. Risk Assessment of the Southeastern Area at 

Letterkenny Army Depot, Operable Units One and Three. Final Report.

Geophex (Geophex, Ltd.). August 2000. Preliminary DraftFocused Feasibility Study, Operable Unit 

Number 10 (On-Post Groundwater), Southern Southeast Industrial Area Portion, Letterkenny Army Depot.

WESTON (Roy F. Weston, Inc.). 1994. Remedial Investigation and Feasibility Study, Letterkenny Army 

Depot, Alternatives Analysis – Date Item AOOA.

WESTON (Roy F. Weston, Inc.). 1996. Environmental Baseline Survey, Letterkenny Army Depot, BRAC 95 

Action.
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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WESTON (Roy F. Weston, Inc.). November 1998a. Final Termination Survey Report for Building 8, 

Letterkenny Army Depot.

WESTON (Roy F. Weston, Inc.). November 1998b. Final Termination Survey Report for Building 7, 

Letterkenny Army Depot.

WESTON (Roy F. Weston, Inc.). May 1999a. Addendum to the Environmental Baseline Survey for 

Letterkenny Army Depot.

WESTON (Roy F. Weston, Inc.). May 1999b. Final Termination Survey Report for Building 5, Letterkenny 

Army Depot.

WESTON (Roy F. Weston, Inc.). June 1999c. Historical Assessment of Radiological Activity at Letterkenny 

Army DepotRevision 1.

WESTON (Roy F. Weston, Inc.). November 1999d. Final Termination Survey Report for Building 33, 

Letterkenny Army Depot.

WESTON (Roy F. Weston, Inc.). November 1999f. Final Termination Survey Report for Building 32, 

Letterkenny Army Depot.

WESTON (Roy F. Weston, Inc.). November 2000a. Final Supplement 1 to the Final Environmental Survey 

for Letterkenny Army Depot, BRAC 95 Action.

WESTON (Roy F. Weston, Inc.). October 2000b. Final Decision Document, Former PCB Transformer Sites 

in the Southeastern (SE) Area, Operable Unit (OU) 8 (DSERTS Site LEAD-125), Letterkenny Army Depot.

WESTON (Roy F. Weston, Inc.). February 2000c. Final Termination Survey Report for Building 441, 

Letterkenny Army Depot.

WESTON (Roy F. Weston, Inc.). February 2001a. Feasibility Study Report for the Gate 1 Guardhouse, 

Building 511, Southeastern Area (SE) Operable Unit (OU) 8, Letterkenny Army Depot. Final Report.

WESTON (Roy F. Weston, Inc.). February 2001b. Final Remedial Investigation and Risk Assessment 

Report for the Gate 1 Guardhouse, Building 511, Southeastern (SE) Area, Operable Unit (OU) 8 (DSERTS 

Site LEAD-126), Letterkenny Army Depot.

WESTON (Roy F. Weston, Inc.). February 2001c. Final Groundwater Vapor Intrusion Risk Assessment, 

Letterkenny Army Depot.
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ATTACHMENT 2 

RISK ASSESSMENT TABLES 
Table 1A

Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations,

Gate 1 Guardhouse, DSERTS Site LEAD-126, SE OU 8,

Letterkenny Army Depot,

Chambersburg, PA

Scenario Timeframe: Future Resident Screen

Medium: Soil

Exposure Medium: Soil

Exposure Point: Contaminants are in soil and exposure to soil is evaluated

Min. Max.

Acetone 0.05 J 0.069 J mg/kg 2/11 0.0357 mg/kg 95% UCL-T

Benzene 0.004 J 0.004 J mg/kg 1/11 0.004 mg/kg Maximum

Naphthalene 0.078 J 15 J mg/kg 14/24 7.73 mg/kg 95% UCL-T

Acenaphthene 0.056 J 3.3 mg/kg 13/24 1.79 mg/kg 95% UCL-T

Benz[a]anthracene 0.053 J 4.1 mg/kg 14/24 0.907 mg/kg 95% UCL-T

Benzo[a]pyrene 0.046 J 4 J mg/kg 11/24 0.729 mg/kg 95% UCL-T

Benzo[b]fluoranthene 0.043 J 2.9 J mg/kg 13/24 0.637 mg/kg 95% UCL-T

Dibenz[a,h]anthracene 0.042 J 0.61 J mg/kg 6/24 0.248 mg/kg 95% UCL-T

Indeno[1,2,3-cd]pyrene 0.046 J 1.5 J mg/kg 12/24 0.41 mg/kg 95% UCL-T

Fluorene 0.058 J 5.5 J mg/kg 16/24 2.79 mg/kg 95% UCL-T

Aluminum 8,450 J 19,300 J mg/kg 11/11 14,674 mg/kg 95% UCL-N

Arsenic 4.2 11 mg/kg 11/11 8.34 mg/kg 95% UCL-N

Barium 63.1 166 mg/kg 11/11 114 mg/kg 95% UCL-T

Chromium 16.5 27.6 mg/kg 11/11 23.2 mg/kg 95% UCL-N

Cobalt 3.6 25 mg/kg 11/11 16.4 mg/kg 95% UCL-N

Iron 25,400 45,400 mg/kg 11/11 38,477 mg/kg 95% UCL-N

Lead 8 37 J mg/kg 11/11 23.2 mg/kg 95% UCL-N

Manganese (nonfood) 75.2 2,860 mg/kg 11/11 1,402 mg/kg 95% UCL-N

Nickel 10.3 28.6 mg/kg 11/11 23 mg/kg 95% UCL-N

Selenium 0.78 1.9 mg/kg 11/11 1.49 mg/kg 95% UCL-N

Thallium 0.27 0.27 mg/kg 1/11 0.155 mg/kg 95% UCL-T

Vanadium 15.6 34.2 mg/kg 11/11 26.5 mg/kg 95% UCL-N

Zinc 31.8 J 97.9 J mg/kg 11/11 68.8 mg/kg 95% UCL-N

Note:

mg/kg = Milligrams per kilogram.

95% UCL = 95% upper confidence limit.

Chemical of Potential Concern

Concentration Detected

Units

Frequency of 

Detection

Exposure Point 

Concentration

Exposure Point 

Concentration Units Statistical Measure

The table presents the chemicals of concern (COCs) and exposure point concentrations for each of the COCs detected in soil (i.e., the concentration that will be used

to estimate the exposure and risk from each COC in the soil). The table includes the range of concentrations detected for each COC, as well as the frequency of

concentration was derived. 

detection (i.e., the number of times the chemical was detected in the samples collected at the site), the exposure point concentration, and how the exposure point

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Table 1B

Summary of Chemicals of Concern and Medium-Specific Exposure Point Concentrations,

PCB Transformer Sites,

Letterkenny Army Depot,

Chambersburg, PA

Scenario Timeframe: Future Resident Screen

Medium: Soil

Exposure Medium: Soil

Exposure Point: Contaminants are in soil and exposure to soil is evaluated

Min. Max.

PCB 0.070 J 0.320 J mg/kg 2/2 0.32 mg/kg

Note:

mg/kg = Milligrams per kilogram.

PCB = Polychlorinated biphenyl.

The table presents the chemicals of concern (COCs) and exposure point concentrations for each of the COCs detected in soil (i.e., the concentration that will be used 

to estimate the exposure and risk from each COC in the soil). The table includes the range of concentrations detected for each COC, as well as the frequency of 

detection (i.e., the number of times the chemical was detected in the samples collected at the site), the exposure point concentration, and how the exposure point 

concentration was derived. 

Exposure Point 

Concentration

Exposure Point 

Concentration 

Chemical of Potential Concern Units

Concentration Detected

Units

Frequency of 

Detection

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Table 1C 

Comparison of Analytical Results with Risk-Based Screening Levels 

at Former PCB Transformer Sites, 

Letterkenny Army Depot, 

Chambersburg, PA 

Location Medium 

PCB Concentration 

(mg/kg)a

Lowest Screening 

Level (mg/kg) 

Screening-Level 

Referenceb

Building 7 (Parcel 2-38) Asphalt 0.051 J 1.0 TSCA 

 Asphalt 0.340 J 1.0 TSCA 

 Asphalt ND TSCA 

Building 18 (Parcel 2-50) Soil 0.070 J 0.32/0.25 RBC/SSL M-GW 

Building 211 (Parcel 2-36) Soil 0.320 J 0.32/0.25 RBC/SSL M-GW 

Building 42 (Parcel 2-45) Asphalt ND 1.0 TSCA 

 Asphalt ND 1.0 TSCA 

aDuplicate results were averaged. 

bTSCA = Total PCB value from 40 CFR 761.61(a)(4) for high occupancy area. Please note that there are no 

regulatory requirements for concentrations less than 1 mg/kg; RBC = EPA Region III residential soil level; 

SSL M-GW = EPA soil screening levels, migration to groundwater, 1 dilution attenuation factor [DAF]. 

A high occupancy area means any area where PCB remediation waste has been disposed of on-site and 

where occupancy for any individual not wearing dermal and respiratory protection for a calendar year 

is: 840 hours or more (an average of 16.8 hours or more per week) for nonporous surfaces, and 335 

hours or more (an average of 6.7 hours or more per week) for bulk PCB remediation waste. Examples 

include a residence; school; daycare center; sleeping quarters; a single or multiple occupancy, 40 hours 

per week work station; a school classroom; a cafeteria in an industrial facility; a control room; and a 

work station on an assembly line. 

J = Analyte present. Reported value may not be accurate or precise (estimated value). 

mg/kg = Milligrams per kilogram. 

ND = Not detected at reporting limit. 
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Table 2 

Summary of Final Chemicals of Concern for Groundwater 

Underlying the PDO Area (1993 Risk Assessment), 

Letterkenny Army Depot, 

Chambersburg, PA 

Final COCs 

ORGANICS 

Chlordane 

Chloroform 

1,1-Dichloroethane 

1,2-Dichloroethane 

1,1-Dichloroethene 

trans-1,2-Dichloroethene 

Pentachlorophenol 

Trichloroethene 

INORGANICS 

Arsenic 

Thallium 

Source: Remedial Investigation of the Property Disposal Office 

Area at Letterkenny Army Depot, Final Report. 

Environmental Science & Engineering, Inc. 

January 1993. 

 
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Table 3 

Summary of Final Chemicals of Concern for Groundwater 

Underlying the SE Area (1994 Risk Assessment), 

Letterkenny Army Depot, 

Chambersburg, PA 

Source: Remedial Investigation of the Southeastern Area at 

Letterkenny Army Depot, Final Report. 

Environmental Science & Engineering, Inc. 

June 1993. 

Final COCs 

ORGANICS 

Benzene 

Carbon tetrachloride 

Chloroform 

1,1-Dichloroethane 

1,2-Dichloroethane 

1,2-Dichloroethene 

Methylene chloride 

Tetrachloroethene 

Trichloroethene 

Vinyl chloride 

INORGANICS 

Arsenic 

Beryllium 

Manganese 

Thallium 
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Table 4 

Summary of Final Chemicals of Concern for Groundwater 

(2001 Vapor Intrusion Risk Assessment), 

Letterkenny Army Depot, 

Chambersburg, PA 

Final COCs Maximum Groundwater 

Concentration (μg/L) 

ORGANICS 

1,1-Dichloroethene 35

Vinyl chloride 90 

Source: Final Groundwater Vapor Intrusion Risk Assessment, 

Letterkenny Army Depot. Roy F. Weston, Inc. 

February 2001. 
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Table 5 

Formulas/Assumptions for Intake Calculations (1993 and 1994 Risk Assessments), 

Letterkenny Army Depot, 

Chambersburg, PA 

Ambient Air, Inhalation Exposure (Volatilization from Soil and Surface Water to Outdoor Air) 

BW x AT

CA x IR x EF x ED

Intake (mg / kg day) a aa aa − =

Where: 

 CAa = Chemical concentration in shower air (mg/m3). 

 IRaa = Intake rate for shower air (m3/day). 

 EFaa = Exposure frequency for shower air (days/year). 

 ED = Exposure duration (years). 

 BW = Body weight (kg). 

 AT = Period of time over which exposure is averaged (days). 

Groundwater, Inhalation Exposure (Theoretical Worker Exposure to Vapors While Showering) 

BW x AT

CA x IR x EF x ED

Intake (mg / kg day) s as as − =

Where: 

 CAs = Chemical concentration in shower air (mg/m3). 

 IRas = Intake rate for shower air (m3/day). 

 EFas = Exposure frequency for shower air (days/year). 

 ED = Exposure duration (years). 

 BW = Body weight (kg). 

 AT = Period of time over which exposure is averaged (days). 

Groundwater, Oral Exposure

BW x AT

CGW x IR x EF x ED

Intake (mg / kg day) gw gw − =

Where: 

 CGW = Chemical concentration in groundwater (mg/L). 

 IRgw = Intake rate for groundwater (L/day). 

 EFgw = Exposure frequency for contaminated groundwater (days/year). 

 ED = Exposure duration (years). 

 BW = Body weight (kg). 

 AT = Period of time over which exposure is averaged (days). 
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Table 5 

Formulas/Assumptions for Intake Calculations (1993 and 1994 Risk Assessments), 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

Exposure Parameters Used for PDO and SE Area Groundwater Risk Assessments: 

AT 

 Carcinogenic effects 70 years x 365 days/year EPA, 1989c 

 Noncancer effects ED (years) x 365 days/year EPA, 1989c 

BW 

Adult (Residential, Worker)

 70 kg Average (male and female) of 50th percentile EPA, 1991a 

 values for age = 18 to 75 years 

CAa

 The concentrations of chemicals in ambient air (at the source and 400 meters downwind of the source) 

that have volatilized for soil are modeled values based on chemical-specific parameters (i.e., soil 

concentration, Henry’s Law constant, Koc, etc.) and site-specific parameters (i.e., soil depth, soil 

porosity, wind velocity, etc.). 

CAs

 The concentration of VOCs in shower air is a modeled value based on the average values presented by 

McKone (1987) for the chemicals of concern (COCs)at the site. McKone values were used because they 

are the most realistic and most conservative. 

1. CGW Measured value 

2. Ratio of chemical concentration in shower air 

to chemical concentration in water (mg/L). 18 L/m3

CA (mg/m ) x CGW (mg/L) x 18 (L/m ) 3 3

s

CGW 

 The upper 95% confidence limit (UCL95) of the mean chemical concentration was used to represent the 

reasonable maximum exposure (RME) concentration. If the UCL95 exceeded the maximum detected 

chemical concentration, the maximum concentration was used to represent the RME. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 5 

Formulas/Assumptions for Intake Calculations (1993 and 1994 Risk Assessments), 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

ED 

Adult (Worker)

 25 years National 95th percentile time at one workplace EPA, 1991b 

EFaa

Worker (Adult)—Current

 12 days/year Assumes that grass in the contamination areas is cut 2 times per month during the 

average growing season of 162 days/year. 

 Other than incidental dermal, inhalation, and oral exposure to soil by maintenance personnel cutting 

grass or performing other minor duties in the potentially contaminated areas, no other worker 

exposure to soil is expected to occur at these sites. 

Worker (Adult)—Future

 250 days/year Amount of time spent at work EPA, 1991b 

EFgw

 250 days/year Number of days spent at work EPA, 1991b 

 Site groundwater is not used as a water supply on the base. Evaluation of future worker exposure to 

groundwater has been requested by EPA and PADEP; therefore, this pathway has been included as a 

conservative estimate of a theoretical future exposure. 

IRaa

Worker (Adult)—Current

 5 m3/day Based on a reasonable upper-bound occupational inhalation rate for an 8-hour 

workday (20 m3/day [EPA, 1991b]) and assumes that maintenance personnel may 

work in the area 2 hours/day. 

Worker (Adult)—Future

 20 m3/day Reasonable upper-bound occupational inhalation 

rate for an 8-hour workday. EPA, 1991b 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 5 

Formulas/Assumptions for Intake Calculations (1993 and 1994 Risk Assessments), 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

IRgw

 1.0 L/day Reasonable occupational ingestion rate EPA, 1991b 

 Site groundwater is not currently used as a water supply on the base. Evaluation of future worker 

exposure to groundwater has been requested by EPA and PADEP; therefore, this pathway has been 

included as a conservative estimate of a theoretical future exposure. 

References

EPA (U.S. Environmental Protection Agency). 1985. Development of Statistical Distributions or 

Ranges of Standard Factors Used in Exposure Assessments. Office of Health and 

Environmental Assessment, Office of Research and Development, Washington, DC. 

EPA/600/8-85/010. 

EPA (U.S. Environmental Protection Agency). 1989a. Exposure Factors Handbook. Final Report. 

Office of Health and Environmental Assessment, Washington, DC. EPA/600/8-89/043. 

EPA (U.S. Environmental Protection Agency). 1989b. Interim Final Guidance for Soil Ingestion 

Rates. Office of Solid Waste and Emergency Response, Washington, DC. OSWER 

Directive 9850.4. 

EPA (U.S. Environmental Protection Agency). 1989c. Risk Assessment Guidance for Superfund 

(RAGS). Volume 1: Human Health Evaluation Manual, Part A. Office of Emergency and 

Remedial Response, Washington, DC. EPA/540/1-89/002. 

EPA (U.S. Environmental Protection Agency). 1991a. Risk Assessment Guidance for Superfund 

(RAGS). Volume 1: Human Health Evaluation Manual, Part B, Development of Risk-Based 

Preliminary Remediation Goals. Office of Emergency and Remedial Response, Washington, 

DC. OERR 9285.7-01B. 

EPA (U.S. Environmental Protection Agency). 1991b. Risk Assessment Guidance for Superfund 

(RAGS). Volume 1: Human Health Evaluation Manual, Supplemental Guidance (Standard 

Default Exposure Factors). Interim Final. Office of Emergency and Remedial Response, 

Washington, DC. OSWER Directive 9285.6-03. 

EPA (U.S. Environmental Protection Agency). 1992a. Dermal Exposure Assessment: Principles and 

Applications. Interim Report. Office of Research and Development, Washington, DC. 

EPA/600/8-91/011B. NTIS No. PB92-205665. 

EPA (U.S. Environmental Protection Agency). 1992b. Health Effects Assessment Summary Tables 

(HEAST). Annual FY 1992. Office of Research and Development and Office of Emergency 

and Remedial Response, Washington, DC. OEHA ECAO-CIN-821. NTIS No. PB92-

921199. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 5 

Formulas/Assumptions for Intake Calculations (1993 and 1994 Risk Assessments), 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

References (continued): 

EPA (U.S. Environmental Protection Agency). 1992c. Health Effects Assessment Summary Tables 

(HEAST). Annual FY 1992; Supplement No. 1. Office of Research and Development and 

Office of Emergency and Remedial Response, Washington, DC. OEHA ECAO-CIN-821A. 

NTIS No. PB92-921199A. 

EPA (U.S. Environmental Protection Agency). 1992d. Health Effects Assessment Summary Tables 

(HEAST). Annual FY 1992; Supplement No. 2. Office of Research and Development and 

Office of Emergency and Remedial Response, Washington, DC. OEHA ECAO-CIN-821B. 

NTIS No. PB92-921102. 

ESE (Environmental Science & Engineering, Inc.). 1998. Endangerment Assessment of the 

Southeastern Area at Letterkenny Army Depot. Final Report. U.S. Army Toxic and 

Hazardous Materials Agency, Installation Restoration Division, Gainesville, FL. Contract 

No. DAAA15-85-D-0017. 

ESE (Environmental Science & Engineering, Inc.). 1992. Remedial Investigation of the Southeastern 

Area at Letterkenny Army Depot (LEAD). Preliminary Draft Report. U.S. Army Toxic and 

Hazardous Materials Agency, Installation Restoration Division, Gainesville, FL. Contract 

No. DAAA15-85-D-0017. 

Hawley, J.D. 1985. “Assessment of Health Risks from Exposure to Contaminated Soil.“ Risk 

Analysis, 5(4):289-302. 

HSDB (Hazardous Substance Data Bank). 1993. National Library of Medicine (NLM). 

Micromedex TOMES PLUS® System CD/ROM, Version 16, Expires 4/30/93. Managed 

by Micromedex, Inc., Denver, CO. 

IRIS (Integrated Risk Information System). 1993. U.S. Environmental Protection Agency. 

Micromedex TOMES PLUS® System CD/ROM, Version 18, Expires 10/31/93. Managed 

by Micromedex, Inc., Denver, CO. 

McKone, T.E. 1987. “Human Exposure to Volatile Organic Compounds in Household Tap 

Water: The Indoor Inhalation Pathway.” Envir. Sci. and Tech., 21(12):1194-1201. 

NOAA (National Oceanic and Atmospheric Administration). Naval Oceanography Command 

Detachment Asheville, and USAFETAC. 1990. International Station Meteorological 

Climate Summary for Glenview, Illinois. Version 1.0. National Climatic Data Center, 

Federal Climate Complex, Asheville, NC. 

Ryan, E.A., E.T. Hawkins, B. Magee, and S.L. Santos. 1987. “Assessing Risk from Dermal 

Exposure at Hazardous Waste Sites.” In: Proceedings of the 8th National Superfund 

Conference. Hazardous Materials Control Research Institute. Silver Spring, MD.
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 6 

Primary Formulas for Groundwater Vapor Intrusion into Buildings/Trenches, 

Letterkenny Army Depot, 

Chambersburg, PA 

Johnson and Ettinger Model: 

Can be run as a “forward calculation” to calculate indoor air concentrations based on actual groundwater 

data, or it can be run as a “reverse calculation” to calculate groundwater risk-based screening 

concentrations (RBSCs) based on indoor inhalation exposure assumptions. 

Sources: 

Environmental Quality Management, Inc. 1997. User’s Guide for the Johnson and Ettinger (1991) Model for 

Subsurface Vapor Intrusion into Buildings. Prepared for E.H. Pechan & Associates, Inc. Springfield, VA. U.S. 

Environmental Protection Agency, Office of Emergency and Remedial Response, Washington, DC. 

September 1997. 

Johnson, P.C, and R.A. Ettinger. 1991. “Heuristic Model for Predicting the Intrusion Rate of Contaminant 

Vapors into Buildings.” Environ. Sci. Technology, 25:1445-1452. 

Worker Exposure: 

Inhalation risk-based air concentrations (Cworker) were calculated for noncancer and carcinogenic effects for 

each chemical of potential concern (COPC). Cworker for carcinogens was based on a target risk (TR) of 1E06. For noncarcinogens, a target hazard quotient (THQ) of 0.1 was used. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 6 

Primary Formulas for Groundwater Vapor Intrusion into Buildings/Trenches, 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

Model for Calculating Noncancer Inhalation Risk-Based Concentration—Construction/Utility Worker: 

Inhalation of VOCsa

IR x EF x ED x (1/RfD )

THQ x AT x BW x 1,000 μg/mg C (μg/m )

i

3

worker =

Parameter Definition Value 

THQ Target hazard quotient. 0.1 

AT Averaging time (days). 365 

BW Body weight (kg). 70 

IR Inhalation rate (m3/day). 16b

EF Exposure frequency (days/year). 42 

ED Exposure duration (years). 1.0 

RfDi Inhalation reference dose (mg/kg-day). Chemicalspecific 

a VOCs are defined as those chemicals with a Henry’s Law constant greater than 0.00001 and a molecular 

 weight less than 200 Daltons. 

b Outdoor worker breathes 1.5 m3/day (moderate activity) for 4 hours and 2.5 m3/day (heavy activity) for 4 

hours. 

Cworker = Construction/utility worker inhalation risk-based concentration based on a target cancer 

risk of 1E-06. 

kg = Kilograms of body weight. 

m3/day = Cubic meters per day. 

μg/m3 = Micrograms per cubic meter. 

mg/kg-day = Milligrams per kilogram per day.
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 6 

Primary Formulas for Groundwater Vapor Intrusion into Buildings/Trenches, 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

Model for Calculating Carcinogenic Inhalation Risk-Based Concentration—Construction/Utility Worker: 

Inhalation of VOCsa

i

3

worker IR x EF x ED x CSF

TR x AT x BW x 1,000 μg/mg C (μg/m ) =

Parameter Definition Value 

TR Target cancer risk. 1.00E-06 

AT Averaging time (days). 25,550 

BW Body weight (kg). 70 

IR Inhalation rate (m3/day). 16b

EF Exposure frequency (days/year). 42 

ED Exposure duration (years). 1.0 

CSFi Inhalation cancer slope factor (mg/kg-day)-1. Chemicalspecific 

a VOCs are defined as those chemicals with a Henry’s Law constant greater than 0.00001 and a molecular 

weight less than 200 Daltons. 

b Outdoor worker breathes 1.5 m3/day (moderate activity) for 4 hours and 2.5 m3/day (heavy activity) for 4 

hours. 

Cworker = Construction/utility worker inhalation risk-based concentration based on a target cancer 

risk of 1E-06. 

kg = Kilograms of body weight. 

m3/day = Cubic meters per day. 

μg/m3 = Micrograms per cubic meter. 

mg/kg-day = Milligrams per kilogram per day. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 6 

Primary Formulas for Groundwater Vapor Intrusion into Buildings/Trenches, 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

Calculating Trench Air Concentration:

These values were used to evaluate the risk to a worker in a trench. Trench was assumed to be a closed 

space with very little air exchange. The following is a modified indoor air model from the Air/Superfund 

National Technical Guidance Study Series, Assessing Potential Indoor Air Impacts for Superfund Sites (EPA451/R-92-002): 

J × A × F × 3,600 

Ctrench = ACH × V × 10-6

Where: 

Ctrench = Concentration of contaminant in the trench (μg/m3). 

J = Contaminant flux estimated from source model, grams per square meter per 

second (g/m2-sec). 

A = Area of the trench floor (square meters [m2]). 

F = Fraction of floor through which contaminant flux can enter. (If this 

 were a building, F = 0.001 for a slab, F = 1 for a dirt floor.) 

 Because this is a trench, set F = 1. 

3,600 = Constant, seconds per hour (sec/hour). 

ACH = Air changes per hour (hr-1) (assume this value is 2). 

V = Volume of the trench (m3). 

10-6 = Conversion factor (micrograms per gram [μg/g]). 

Potential Residential Exposure: 

A forward calculation of the model was used to predict the indoor residence air concentration based on the 

maximum, sitewide groundwater concentration for each compound. This indoor air concentration (Cbuilding) 

was then compared to inhalation risk-based screening concentrations calculated for the adult resident and 

child resident for both noncancer and carcinogenic effects. The target cancer risk was 1E-06 and the target 

hazard quotient was 0.1. As was done for the construction/utility worker scenario, these risk-based 

screening concentrations (Cresident) were compared with the Cbuilding concentrations to determine 

contaminants of potential concern. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 6 

Primary Formulas for Groundwater Vapor Intrusion into Buildings/Trenches, 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

Model for Calculating Noncancer Inhalation Risk-Based Concentration—Adult Resident: 

Inhalation of VOCsa

IR x EF x ED x (1/RfD )

THQ x AT x BW x 1,000 μg/mg C (μg/m )

i

3

adult =

Parameter Definition Value 

THQ Target hazard quotient. 0.1 

AT Averaging time (days). 365 x ED 

BW Body weight (kg). 70 

IR Inhalation rate (m3/day). 13.3b

EF Exposure frequency (days/year). 350 

ED Exposure duration (years). 30 

RfDi Inhalation reference dose (mg/kg-day). Chemicalspecific 

 

a VOCs are defined as those chemicals with a Henry’s Law constant greater than 0.00001 and a molecular 

weight less than 200 Daltons. 

b Adult (19-65+ years) resident long-term inhalation rate based on male/female average. 

 

Cadult = Adult resident inhalation risk-based concentration based on a target hazard quotient of 0.1. 

kg = Kilograms of body weight. 

m3/day = Cubic meters per day. 

μg/m3 = Micrograms per cubic meter. 

mg/kg-day = Milligrams per kilogram per day. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 6 

Primary Formulas for Groundwater Vapor Intrusion into Buildings/Trenches, 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

Model for Calculating Carcinogenic Inhalation Risk-Based Concentration—Adult Resident: 

Inhalation of VOCsa

i

3

adult IR x EF x ED x CSF

TR x AT x BW x 1,000 μg/mg C (μg/m ) =

Parameter Definition Value 

TR Target cancer risk. 1.00E-06 

AT Averaging time (days). 365 x 70 

BW Body weight (kg). 70 

IR Inhalation rate (m3/day). 13.3b

EF Exposure frequency (days/year). 350 

ED Exposure duration (years). 30 

CSFi Inhalation cancer slope factor (mg/kg-day)-1. Chemicalspecific 

 

a VOCs are defined as those chemicals with a Henry’s Law constant greater than 0.00001 and a molecular 

weight less than 200 Daltons. 

b Adult (19-65+ years) resident long-term inhalation rate based on male/female average. 

Cadult = Adult resident inhalation risk-based concentration based on a target cancer risk of 1E-06. 

kg = Kilograms of body weight. 

m3/day = Cubic meters per day. 

μg/m3 = Micrograms per cubic meter. 

mg/kg-day = Milligrams per kilogram per day. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 6 

Primary Formulas for Groundwater Vapor Intrusion into Buildings/Trenches, 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

Model for Calculating Noncancer Inhalation Risk-Based Concentration—Child Resident: 

Inhalation of VOCsa

IR x EF x ED x (1/RfD )

THQ x AT x BW x 1,000 μg/mg C (μg/m )

i

3

child =

Parameter Definition Value 

THQ Target hazard quotient. 0.1 

AT Averaging time (days). 365 x ED 

BW Body weight (kg). 15 

IR Inhalation rate (m3/day). 8.6b

EF Exposure frequency (days/year). 350 

ED Exposure duration (years). 6 

RfDi Inhalation reference dose (mg/kg-day). Chemicalspecific 

 

a VOCs are defined as those chemicals with a Henry’s Law constant greater than 0.00001 and a molecular 

weight less than 200 Daltons. 

b Child resident long-term inhalation rate based on average of children 1-2, 3-5, and 6-8 years old. 

Cchild = Child inhalation risk-based concentration based on a target hazard quotient of 0.1. 

kg = Kilograms of body weight. 

m3/day = Cubic meters per day. 

μg/m3 = Micrograms per cubic meter. 

mg/kg-day = Milligrams per kilogram per day. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 6 

Primary Formulas for Groundwater Vapor Intrusion into Buildings/Trenches, 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

Model for Calculating Carcinogenic Inhalation Risk-Based Concentration—Child Resident: 

Inhalation of VOCsa

i

3

child IR x EF x ED x CSF

TR x AT x BW x 1,000 μg/mg C (μg/m ) =

Parameter Definition Value 

TR Target cancer risk. 1.00E-06 

AT Averaging time (days). 365 x 70 

BW Body weight (kg). 15 

IR Inhalation rate (m3/day). 8.6b

EF Exposure frequency (days/year). 350 

ED Exposure duration (years). 6 

CSFi Inhalation cancer slope factor (mg/kg-day)-1. Chemicalspecific 

 

a VOCs are defined as those chemicals with a Henry’s Law constant greater than 0.00001 and a molecular 

weight less than 200 Daltons. 

b Child resident long-term inhalation rate based on average of children 1-2, 3-5, and 6-8 years old. 

Cchild = Child inhalation risk-based concentration based on a target cancer risk of 1E-06. 

kg = Kilograms of body weight. 

m3/day = Cubic meters per day. 

μg/m3 = Micrograms per cubic meter. 

mg/kg-day = Milligrams per kilogram per day. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 6 

Primary Formulas for Groundwater Vapor Intrusion into Buildings/Trenches, 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

Estimation of cancer risks and hazard quotients for adult and child resident using a risk-ratio approach as 

follows: 

Incremental lifetime cancer risk is determined for each chemical of potential concern (COPC) by the 

following algorithm: 

Cancer risk = (Cbuilding * 1E-06) / (Cresident) 

Where: 

Cbuilding = Indoor air concentration based on maximum sitewide groundwater 

concentration (milligrams per kilogram [mg/kg]). 

Cresident = Inhalation risk-based concentration (RBC) (mg/kg) for the adult or child 

resident, target cancer risk of 1E-06. 

The hazard quotients (HQs) for each COPC are evaluated using the following algorithm: 

HQ = (Cbuilding * 0.1) / (Cresident) 

Where: 

Cbuilding = Indoor air concentration based on maximum sitewide groundwater 

concentration (mg/kg). 

Cresident = Inhalation RBC (mg/kg) for the adult or child resident, target HQ of 0.1. 

Sources: 

EA (EA Engineering, Science, and Technology). 1991. Site Investigation, LEAD. 

EPA (U.S. Environmental Protection Agency). 2000. Integrated Risk Information System (IRIS). Peerreviewed toxicity database maintained by the U.S. Environmental Protection Agency, Washington, DC. 

EPA (U.S. Environmental Protection Agency). 2000. Risk-Based Concentration Tables. EPA Region III, 

Philadelphia, PA. October 2000. 

EPA (U.S. Environmental Protection Agency). 1998. Risk Assessment Guidance for Superfund, Volume 1 

– Human Health Evaluation Manual. Supplemental Guidance. Dermal Risk Assessment Interim Guidance. 6 

November 1998. Peer Consultation Workshop Draft. 

EPA (U.S. Environmental Protection Agency). 1997. Exposure Factors Handbook, Volume I, General 

Factors. EPA/600/P-95/002Fa. Office of Research and Development, Washington, DC. August 1997. 

(Update to Exposure Factors Handbook, May 1989.) 

EPA (U.S. Environmental Protection Agency). 1997. Health Effects Assessment Summary Tables (HEAST). 

FY-1997 Update. EPA-540-R-97-036. PB 97-921199. Office of Solid Waste and Emergency Response. 

Washington, DC. July 1997. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 6 

Primary Formulas for Groundwater Vapor Intrusion into Buildings/Trenches, 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

Sources (continued): 

EPA (U.S. Environmental Protection Agency). 1996. Soil Screening Guidance: Technical Background 

Document. EPA/540/R-956/128. PB96-963502. Office of Solid Waste and Emergency Response, 

Washington, DC. May 1996. 

EPA (U.S. Environmental Protection Agency). 1996. Soil Screening Guidance: Technical Background 

Document and Soil Screening Guidance: User’s Guide. 9355-4.23. EPA/540/R-96/018. PB96-963505. Office of 

Solid Waste and Emergency Response, Washington, DC. April 1996. 

EPA (U.S. Environmental Protection Agency). 1989. Risk Assessment Guidance for Superfund (RAGS), 

Volume I, Human Health Evaluation Manual (Part A). Interim Final. EPA/540/1-89/002. Office of Solid 

Waste and Emergency Response, Washington, DC. 

WESTON (Roy F. Weston). 2001. Final Groundwater Vapor Intrusion Risk Assessment, Letterkenny Army 

Depot. February 2001. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 7 

Weight-of-Evidence Classification System for Potential Carcinogens, 

Letterkenny Army Depot, 

Chambersburg, PA 

EPA 

Category 

Description 

of Group Description of Evidence 

Group A Human carcinogen Sufficient evidence from epidemiological studies to 

support a causal association between exposure and 

cancer. 

Group B1 Probable human carcinogen Limited evidence of carcinogenicity in humans from 

epidemiological studies. 

Group B2 Probable human carcinogen Sufficient evidence of carcinogenicity in animals, but 

inadequate data in humans. 

Group C Possible human carcinogen Limited evidence of carcinogenicity in animals and no 

data in humans. 

Group D Not classified Inadequate evidence of carcinogenicity in animals. 

Group E No evidence of carcinogenicity 

in humans 

No evidence of carcinogenicity in at least two adequate 

animal tests or in both epidemiological and animal 

studies. 

Source: U.S. Environmental Protection Agency (EPA). 1989. Risk Assessment Guidance for Superfund 

(RAGS), Volume I, Human Health Evaluation Manual, Part A. Office of Emergency and Remedial 

Response, Washington, DC. EPA/540/1-89/002. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 8 

Chronic Dose-Response Toxicity Constants for the COCs in the SE and PDO 

Areas at LEAD (1993 and 1994 Risk Assessments), 

Letterkenny Army Depot, 

Chambersburg, PA 

Chemical 

Oral RfD 

(UF)* 

Inhal RfD 

(UF)* 

Oral 

CSF* 

Oral 

WoE* 

Inhal 

CSF* 

Inhal 

WoE* 

Inorganic Chemicals (IOC) 

Arsenic 3 x 10-4 (3) — 1.8I1 A 50 A 

Beryllium 5 x 10-3 (100) — 4.3 B2 8.4# B2 

Cadmium (aqueous matrix) 5 x 10-4 (10) — — — 

Cadmium (solid matrix) 1 x 10-3 (10) — — 6.1# B1 

Chromium, totalI2 5 x 10-3 (500) NDI3 — 41# A 

Copper 3.7 x 10-2 #, I4 (2) — — — 

Lead —I5 — NDI6 B2 NDI6 B2 

Manganese 

(aqueous matrix) 5 x 10-3 (1) — — — 

Manganese 

(solid matrix) 1.4 x 10-1 (1) 1.1 x 10-4 (900) — — 

Nickel 2 x 10-2 (300) — — 8.4 x 10-1 #, I7 A 

Thallium 7 x 10-5 #, I10 (3,000) — — — 

Zinc 3 x 10-1 (10) — — — 

Pesticides/Polychlorinated Biphenyls (PCBs) 

Chlordane, total 6 x 10-5 (1,000) — 1.3 B2 1.3# B2 

Heptachlor 5 x 10-4 (100) — 4.5 B2 4.5# B2 

Semivolatile Organic Chemicals (SOC) 

Bis(2-ethylhexyl)phthalate 2 x 10-2 (1,000) — 1.4 x 10-2 B2 NDS1 B2 

Diethyl phthalate 8 x 10-1 (1,000) — — — 

Pentachlorophenol 3 x 10-2 (100) — 1.2 x 10-1 B2 NDS1 B2 

Volatile Organic Chemicals (VOC) 

Acetone 1 x 10-1 (1,000) — — — 

Benzene 2 x 10-2 V1 (NA) 5.7 x 10-5 V2 (NA) 2.9 x 10-2 A 2.9 x 10-2 # A 

Bromodichloromethane 2 x 10-2 (1,000) — 1.3 x 10-1 B2 NDV3 B2 

Carbon tetrachloride 7 x 10-4 (1,000) — 1.3 x 10-1 B2 5.3 x 10-2 # B2 

Chloroform 1 x 10-2 (1,000) — 6.1 x 10-3 B2 8.1 x 10-2 # B2 

Dichloroethane, 1,1- 1 x 10-1 # (1,000) 1 x 10-1 (1,000) NDV3 C NDV4 C 

Dichloroethane, 1,2- 7 x 10-2 V5 (100) 2.9 x 10-3 V2 (NA) 9.1 x 10-2 B2 9.1 x 10-2 # B2 

Dichloroethene, 1,1- 9 x 10-3 (1,000) — 6 x 10-1 C 1.8 x 10-1 C 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 8 

Chronic Dose-Response Toxicity Constants for the COCs in the SE and PDO Areas 

at LEAD (1993 and 1994 Risk Assessments), 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

Chemical 

Oral RfD 

(UF)* 

Inhal RfD 

(UF)* 

Oral 

CSF* 

Oral 

WoE* 

Inhal 

CSF* 

Inhal 

WoE* 

Dichloroethene, 1, 2-, 

total 9 x 10-3 (1,000) — — — 

Methylene chloride 6 x 10-2 (100) 8.6 x 10-1 # (100) 7.5 x 10-3 B2 1.6 x 10-3 B2 

Tetrachloroethene 1 x 10-2 (1,000) — 5.1 x 10-2 V6 B2V6 1.8 x 10-3 V6 B2V6

Toluene 2 x 10-1 (1,000) 1.1 x 10-1 # (100) — — 

Trichloroethane, 1,1,1- 9 x 10-2 (1,000) 3 x 10-1 # (1,000) — — 

Trichloroethane, 1,1,2- 4 x 10-3 (1,000) — 5.7 x 10-2 C 5.7 x 10-2 # C 

Trichloroethene 6 x 10-3 V2 — 1.1 x 10-2 V6 B2V6 6 x 10-3 V2 B2V6

Trichlorofluoromethane 3 x 10-1 (1,000) 2 x 10-1 # (10,000) — — 

Vinyl chloride — — 1.9 # A 3 x 10-1 # A 

Notes: CSF = Cancer slope factor [(mg/kg-day)-1]. 

 inhal = Inhalation. 

 NA = Not available. 

 ND = Not determined. 

 RfD = Reference dose (mg/kg-day). 

 UF = Uncertainty factor (includes any applicable modifying factor). 

 WoE = Weight-of-evidence for ranking as a human carcinogen (see Table 4). 

(I1) CSF for arsenic based on unit cancer risk of 5 x 10-5 micrograms per liter (μg/L)-1 proposed by 

Risk Assessment Forum (EPA, 1991a). 

(I2) All values are for hexavalent chromium; a less conservative oral RfD of 1E+00 mg/kg-day for 

trivalent chromium is also available. 

(I3) Inhalation RfD for chromium has been withdrawn from IRIS pending further EPA review. 

(I4) RfD for copper based on the maximum contaminant level (MCL) of 1.3 mg/L (56 FR 26460) 

and assumes that a healthy 70-kg adult consumes 2 L of water per day. 

(I5) EPA prefers to use a biokinetic uptake model to evaluate lead exposure rather than the 

reference dose method. 

(I6) Although EPA has classified lead as a Group B2 suspect human carcinogen via ingestion and 

inhalation, no CSF has been developed for either of these exposure pathways. 

(I7) Inhalation of CSF for nickel refinery dust. 

(I10) This value (for soluble thallium salts) has been withdrawn from IRIS pending further review. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

MK01|O:\02281016.008\PHASE II\ROD\ROD_ATTACHMENT 2.DOC FINAL 2-25 

Table 8 

Chronic Dose-Response Toxicity Constants for the COCs in the SE and PDO 

Areas at LEAD (1993 and 1994 Risk Assessments), 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

(S1) Although EPA has classified this synthetic organic compound (SOC) as a Group B2 suspect 

human carcinogen via inhalation, no CSF has been developed for this exposure pathway. 

(V1) RfD for benzene based on the EPA 10-day health advisory of 0.235 mg/L (EPA, 1987) and 

assumes that a healthy 10-kg child consumes 1 L of water per day. 

(V2) Interim value obtained from EPA Environmental Criteria and Assessment Office (ECAO), as 

recommended by EPA Region III. 

(V3) Although EPA has classified this chemical as a Group C possible human carcinogen via 

ingestion, no CSF has been developed for this exposure pathway. 

(V4) Although EPA has classified this chemical as a Group C possible human carcinogen via 

inhalation, no CSF has been developed for this exposure pathway. 

(V5) RfD for 1,2-dichloroethane based on a chronic oral no-observed-adverse-effect level (NOAEL) 

for rats of 7 mg/kg-day (ATSDR, 1988) and an uncertainty factor of 100 (10X for sensitive 

human subpopulations and 10X for animal-to-human extrapolation). 

(V6) CSFs and WoEs for this VOC have been withdrawn from IRIS pending further review; the 

listed value is from EPA/HEAST (1991). 

*All RfDs, CSFs, and WoEs are available in IRIS (1993), unless otherwise noted. 

#This value is available in EPA/HEAST (1992). 

Sources: ATSDR (Agency for Toxic Substance and Disease Registry). 1988. Toxicological Profile for 

1,2-Dichloroethane. Prepared by Clement Associates. U.S. Public Health Service, Atlanta, 

GA. NTIS No. PB90-171422. 

 EPA (U.S. Environmental Protection Agency). 1991. Health Effects Assessment Summary 

Tables (HEAST). Annual FY 1991. Office of Research and Development and Office of 

Emergency and Remedial Response, Washington, DC. OERR 92006-303(91-1). 

EPA (U.S. Environmental Protection Agency). 1987. Health Advisories for 25 Organics. Office 

of Drinking Water, Washington, DC. NTIS No. PB87-235578. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

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Table 9 

Toxicity Values for Chemicals of Potential Concern from 

Groundwater Vapor Intrusion Risk Assessment, 

Letterkenny Army Depot, 

Chambersburg, PA 

Chemical 

RfDi

(mg/kg-day) 

RfCa

(mg/m3) 

CSFi

(mg/kg-day)-1

URFb

(μg/m3)-1

Acetone 1.00 x 10-1 c 3.5 x 10-1 c NTV NTV 

Benzene 1.70 x 10-3 5.95 x 10-3 2.90 x 10-2 8.29 x 10-6

Bromodichloromethane 2.00 x 10-2 c 7.00 x 10-2 c 6.20 x 10-2 c 1.77 x 10-5 c

Carbon tetrachloride 5.71 x 10-4 2.00 x 10-3 5.30 x 10-2 1.51 x 10-5

Chloroethane 2.90 10.2 2.90 x 10-3 c 8.29 x 10-7 c

Chloroform 8.60 x 10-5 3.01 x 10-4 8.10 x 10-2 2.31 x 10-5

1,1-Dichloroethane 1.40 x 10-1 4.90 x 10-1 NTV NTV 

1,2-Dichloroethane 1.40 x 10-3 4.90 x 10-3 9.10 x 10-2 2.60 x 10-5

1,1-Dichloroethene 9.00 x 10-3 c 3.15 x 10-2 c 1.75 x 10-1 5.00 x 10-5

1,2-Dichloroethene 9.00 x 10-3 c 3.15 x 10-2 NTV NTV 

cis-1,2-Dichloroethene 1.00 x 10-2 c 3.50 x 10-2 c NTV NTV 

trans-1,2-Dichloroethene 2.00 x 10-2 c 7.00 x 10-2 c NTV NTV 

Ethylbenzene 2.90 x 10-1 1.02 NTV NTV 

Methylene chloride 8.60 x 10-1 3.01 1.65 x 10-3 4.71 x 10-7

Tetrachloroethene 1.40 x 10-1 4.90 x 10-1 2.00 x 10-3 5.71 x 10-7

1,1,2,2-Tetrachloroethane 6.00 x 10-2 c 2.10 x 10-1 c 2.00 x 10-1 5.71 x 10-5

Toluene 1.14 x 10-1 3.99 x 10-1 NTV NTV 

1,1,1-Trichloroethane 6.30 x 10-1 2.21 NTV NTV 

1,1,2-Trichloroethane 4.00 x 10-3 c 1.40 x 10-2 c 5.60 x 10-2 1.60 x 10-5

Trichloroethene 6.00 x 10-3 c 2.10 x 10-2 c 6.00 x 10-3 1.71 x 10-6

Vinyl chloride 2.80 x 10-2 9.80 x 10-2 3.00 x 10-2 8.57 x 10-6

Xylene, total 2.00 c 7.00 c NTV NTV 

Source: Final Groundwater Vapor Intrusion Risk Assessment, Letterkenny Army Depot. February 

2001. Roy F. Weston, Inc. 

b Adjustment factor applied to inhalation slope factor to calculate unit risk factor = 20 m3/day x 

1/70 kg x 1,000 μg/mg. 

c Assumed route-to-route extrapolation. 

CSFi = Inhalation cancer slope factor. 

μg/m3 = Micrograms per cubic meter. 

mg/m3 = Milligrams per cubic meter. 

mg/kg-day = Milligrams per kilogram per day. 

NTV = No toxicity value 

RfC = Reference concentration. 

RfDi = Inhalation reference dose. 

URF = Unit risk factor. 
a See Section 7 of ROD for description of screening level risk 

assessment process.

b Risk-based screening concentration(adjusted EPA Region III riskbased screening concentrations for residential soil ingestion), EPA 

soil-screening level (inhalation and groundwater protection), and 

PADEP Act 2 medium-specific concentrations, direct contact, 

residential soil.

Human Health

SLRA

Level 1

Compare Maximum 

Detected Levels to

Residential Human 

Health Benchmarksb

Level 1

Compare Maximum 

Detected Levels to

Residential Human 

Health Benchmarksb

Criteria

Exceeded

?

Level 2

Estimate Industrial 

Worker/Commercial 

Worker Risk

(Risk Ratio)

Level 2

Estimate Industrial 

Worker/Commercial 

Worker Risk

(Risk Ratio)

Criteria 

Exceeded

?

Additional 

Sampling

Investigation 

and/or

Baseline

Risk

Assessment 

Additional 

Sampling

Investigation 

and/or

Baseline

Risk

Assessment 

Property

Transfer

Property

Transfer

No

BRAC Cleanup 

Team

Decision Point

BRAC Cleanup 

Team

Decision Point

Compare 

Exceedances to 

Background

Compare 

Exceedances to 

Background

Yes

No

Yes

Base 

Realignment 

and Closure 

(BRAC) Parcel

Figure 2-1

Screening Level Risk Assessmenta Process

Letterkenny Army Depot

Chambersburg, PA

Figure 2-1

Screening Level Risk Assessmenta Process

Letterkenny Army Depot

Chambersburg, PA

MK01|O:\02281016.008\PhaseII\ROD\Fig2-1.ppt FINAL 2-26
LETTERKENNY ARMY DEPOT PHASE II PARCELS - RECORD OF DECISION

MK01|O:\02281016.008\PHASE II\ROD\ROD_ATTACHMENT 3.DOC FINAL

ATTACHMENT 3 

GROUNDWATER LEVEL MONITORING PROGRAM TO SUPPORT 

TRANSFER OF BASE REALIGNMENT AND CLOSURE (BRAC) PARCELS 

AT LETTERKENNY ARMY DEPOT, CHAMBERSBURG, PA 
LETTERKENNY ARMY DEPOT PHASE II PARCELS - RECORD OF DECISION

MK01|O:\02281016.008\PHASE II\ROD\ROD_ATTACHMENT 3.DOC FINAL 3-1 

ATTACHMENT 3 

GROUNDWATER LEVEL MONITORING PROGRAM TO SUPPORT TRANSFER OF 

BASE REALIGNMENT AND CLOSURE (BRAC) PARCELS, 

LETTERKENNY ARMY DEPOT, CHAMBERSBURG, PA

INTRODUCTION

The information presented herein provides supporting information to current and future landowners and tenants 

of BRAC parcels at Letterkenny Army Depot (LEAD) concerning groundwater elevations at LEAD, and how to 

determine if the owner/tenant can safely perform excavation activities (i.e., comply with environmental deed 

provisions) within the BRAC parcels. Based on many years of groundwater monitoring at LEAD, it is known that 

the groundwater levels fluctuate. The deed restrictions are in-place due to the presence of and to prevent 

potential exposure to volatile organic compounds (VOCs) in groundwater beneath the BRAC parcels. Therefore, 

to provide the owner/tenant with a general understanding of where groundwater can occur at the shallower 

conditions documented over the years, the groundwater elevation data were summarized in a map as discussed 

in more detail in the following paragraphs. The shallower conditions are historically experienced in seasons with 

greater amounts of precipitation. Therefore, these shallower groundwater conditions are often referred to as 

“seasonally high groundwater conditions.” 

This information is also used to establish a real-time system for determining whether excavation activities in the 

various BRAC parcels would be allowed based on the environmental provisions in-place for the property. The 

attached quick-reference tables provide an easy method for the landowners to determine whether groundwater 

conditions within their parcels are suitable for excavation activities at various depths. In accordance with the 

environmental deed provisions of the BRAC property transfer (as determined by risk evaluations conducted for 

the BRAC parcels and as established by the Army because groundwater levels vary at the site), soil excavation or 

other soil disturbance activities and construction of human-occupied subsurface structures are prohibited within 

3 feet (ft) of the groundwater level at a particular parcel, unless approved by the Army. The allowance for 

excavation or other soil activities will be determined by monitoring the groundwater at or near the subject parcel 

as described in the following paragraphs. The allowance for subsurface structures will be determined by the 

seasonal high groundwater conditions described here. 

If soil excavation activities are necessary within 3 ft of groundwater, at its seasonal high (or as measured prior to 

construction or soil disturbance activities), then additional health and safety measures must be implemented by 

the owner/tenant/contractor (e.g., Occupational Safety and Health Administration [OSHA]-trained workers must 

be used and a Health and Safety Plan [HASP] must be written/implemented) to prevent potential exposure to 

VOC-contaminated groundwater during excavation or other soil disturbance activities. In addition, human 

occupied structures cannot be constructed without prior permission of the Army, the Pennsylvania Department of 

Environmental Protection (PADEP) and the U.S. Environmental Protection Agency (EPA) if the floor of the 

structure will be within 3 ft or less of the seasonal high groundwater level. This attachment details the 

methodology for developing the basewide shallow groundwater map and presents the proposed groundwater 

monitoring program for the BRAC parcels at LEAD. 

BACKGROUND

Figure 3-1* shows the areas where seasonally high groundwater exists at depths of 8 ft or less below ground

surface (bgs) (At this time, the Army is transferring only surface structures and soil to a depth of 8 ft bgs.) This 

figure was developed using water-level measurements collected from existing wells as part of numerous 

remedial investigations (RIs) conducted at LEAD since 1987 and the calculation method discussed in this 

attachment (see reference list). The historical water-level measurements provided direct information on the depth 

and variability of the groundwater level below ground surface. Groundwater levels across the base fluctuate in 

 

*

The Open Vehicle Storage Area (OVSA) (this area is not one of the Phase II parcels) was not included in this mapping effort 

because groundwater sampling results to date indicate that this topographically high area of the Depot, which is underlain by 

shale bedrock, has not been impacted by VOCs. In addition, data for areas north of the test track were not included because 

there are no Phase II BRAC parcels in this area and data from recently installed wells are still being collected and interpreted. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS - RECORD OF DECISION

MK01|O:\02281016.008\PHASE II\ROD\ROD_ATTACHMENT 3.DOC FINAL 3-2 

response to recharge from precipitation. The shallowest groundwater typically occurs in the spring, when a larger 

amount of precipitation (rain and snowmelt) infiltrates the subsurface to recharge the shallow aquifer. 

The seasonally high groundwater level was determined through a statistical analysis of historical water-level 

monitoring data as follows: the 95% prediction limit was calculated as described in Statistical Analysis of GroundWater Monitoring Data at RCRA Facilities, Interim Final Guidance (EPA, 1989). The statistically determined 95% 

prediction limit means that there is a 95% probability (or very high likelihood) that when groundwater elevations 

are measured in the future, the levels will not be shallower than 8 ft bgs. The formula for calculating the prediction 

limit is as follows: 

Prediction Limit = Mean + [Student’s “t” * standard deviation * (1 + 1/square root 

of the number of samples)] 

Figure 3-1 contains the 95% prediction limit for individual wells and contour lines showing areas with relatively 

shallow groundwater. Shallow groundwater typically occurs in stream bottoms and low-lying areas. Topography 

and surface-water features were used to construct the contours between wells with water-level data. 

GROUNDWATER LEVEL MONITORING PROGRAM—BRAC PARCELS

Using the map of seasonally high groundwater areas at LEAD, a number of wells located within these shallow 

groundwater areas were selected for continuous water-level monitoring on a parcel-by-parcel basis for the Phase II 

parcels (see Table 3-1). The listed locations of monitor wells in Table 3-1 are shown in reference to the Phase II BRAC 

parcels in Figures 3-2 and 3-3. Groundwater levels in these wells will be continuously monitored to determine 

whether excavation activities within nearby BRAC parcels would encounter shallow groundwater within the 3-ft 

buffer zone beneath the base of a given excavation. The continuous water-level data will be collected to also 

evaluate the seasonal and short-term variation in groundwater height throughout the year to help support any 

future construction activities involving intrusive actions (i.e., utilities, foundation, or subsurface structure). Access 

to these wells will also be made available for manual water-level measurements in the event that the electronic data 

are unavailable. Included in Table 3-1 are the minimum water-level depths that must exist at each location for the 

various excavation depths. If these minimum depth-to-water values cannot be met, OSHA-trained workers and 

implementation of a HASP, as well as approval from the Army, would be required for the excavation work. 

The continuous depth-to-water measurements will be collected using electronic datalogging devices that have been or 

will be installed in the selected monitor wells cited in Table 3-1. Wells in the vicinity of Building 37 will provide data 

for both the continuous groundwater monitoring program, as well as for the ongoing bioremediation project. The 

electronic groundwater level data from the dataloggers will be provided to the Letterkenny Industrial 

Development Authority (LIDA) from the Army. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

MK01|O:\02281016.008\PHASE II\ROD\ROD_ATTACHMENT 3.DOC FINAL

3-3 

REFERENCES 

EPA (U.S. Environmental Protection Agency). 1989. Statistical Analysis of Ground-Water Monitoring Data at RCRA 

Facilities, Interim Final Guidance. 

EPSYS (Epsys Corporation). 2001. Seasonally High Groundwater Determination for the Phase 2 BRAC Parcels, 

Letterkenny Army Depot. Final Report. 

ESE (Environmental Science & Engineering, Inc.). 1993a. Remedial Investigation of the Property Disposal Office Area at 

Letterkenny Army Depot. Final Report. 

ESE (Environmental Science & Engineering, Inc.). 1993b. Remedial Investigation of the Southeastern Area at 

Letterkenny Army Depot. Final Report. 

ESE/FDGTI (Environmental Science & Engineering, Inc./Fluor Daniel GTI, Inc.). 1997b. Remedial Investigation for 

Southeastern Area Operable Unit 4 at Letterkenny Army Depot. Draft Report. 

ESE/FDGTI (Environmental Science & Engineering, Inc./Fluor Daniel GTI, Inc.). 1998b. Remedial Investigation for 

Southeastern Area Operable Unit 2 Industrial Wastewater Sewer Lines and Associated Contaminated Soils at Letterkenny 

Army Depot. Draft Report. 

FDGTI (Fluor Daniel GTI, Inc.) 1997b. Southeastern Area Operable Unit 5, Area A and Area B, Remedial Investigation.

Draft Report. 

FEC/ESE (Foothill Engineering Consultants and Environmental Science & Engineering, Inc.). SE OU 3 Focused 

Feasibility Study. In preparation. 

Geophex (Geophex, Ltd.). 2000. SE OU 10 Focused Feasibility Study. Draft. July 2000. 

IT (IT Corporation). 1999. Remedial Investigation Report, Southeastern Area Operable Unit 6, Off-Post Contaminated 

Groundwater. Preliminary Draft (Revision 1). 

WESTON (Roy F. Weston, Inc.). Dye Tracer Study of the Bedrock Aquifer at the Property Disposal Office (PDO) Area of 

Letterkenny Army Depot, Chambersburg, PA. May 2000-Present/Ongoing. 

WESTON (Roy F. Weston, Inc.). Oil Burn Pit Groundwater Investigation—PDO OU 4—Letterkenny Army Depot, 

Chambersburg, PA. 1998 - Present/Ongoing. 
LETTERKENNY ARMY DEPOT PHASE II PARCELS—RECORD OF DECISION

MK01|O:\02281016.008\PHASE II\ROD\ROD_ATTACHMENT 3.DOC FINAL

3-4 

Table 3-1 

Phase II Parcels and Associated Monitoring Wells for Determining Excavation Limits, 

Letterkenny Army Depot, 

Chambersburg, PA 

Minimum Depth-to-Water (ft TOC) Required for 

Various Excavation Depths 

(See Explanation Belowa) 

Parcel ID Well(s) 

Top of 

Casing 

Elevation 

(ft msl) 

Ground 

Elevation 

(ft msl) 

Casing 

Stick-Up 

(ft) 8 ft 7 ft 6 ft 5 ft 4 ft 3 ft 

2-35 83-1 687.40 684.1 3.3 14.3 13.3 12.3 11.3 10.3 9.3 

2-36 83-12 688.00 685.1 2.9 13.9 12.9 11.9 10.9 9.9 8.9 

2-37 00-SE-1 N/A N/A N/A N/A N/A N/A N/A N/A N/A 

2-38 

2-39 

2-40 

83-12 688.0 685.1 2.9 13.9 12.9 11.9 10.9 9.9 8.9 

2-41 83-12 688.0 685.1 2.9 13.9 12.9 11.9 10.9 9.9 8.9 

2-42 97-37-18 683.52 684.71 -1.19 9.81 8.81 7.81 6.81 5.81 4.81 

2-43 

2-44 

In these areas depth to groundwater during seasonally high groundwater conditions is 

greater than 11 ft bgs.b

2-45 

2-46 

96-37-16 693.52 690.45 3.07 14.07 13.07 12.07 11.07 10.07 9.07 

2-47 

2-48 

2-49 

2-50 

2-51 

2-52 

2-53 

2-54 

2-55 

2-56 

2-57 

2-58 

2-59 

2-60 

2-61 

2-62 

2-63 

2-64 

2-65 

2-66 

In these areas depth to groundwater during seasonally high groundwater conditions is 

greater than 11 ft bgs.b

2-67 

2-68 

97-37-18 683.52 684.71 -1.19 9.81 8.81 7.81 6.81 5.81 4.81 

2-69 00-SE-1 N/A N/A N/A N/A N/A N/A N/A N/A N/A 

2-70 

2-71 

2-72 

2-74 

In these areas depth to groundwater during seasonally high groundwater conditions is 

greater than 11 ft bgs.b

2-75 99-PDO-PZ1 639.40 639.4 0 11 10 9 8 7 6 

2-76 00-PDO-5 N/A N/A N/A N/A N/A N/A N/A N/A N/A 

2-77 83-1 687.40 684.10 3.3 14.3 13.3 12.3 11.3 10.3 9.3 
LETTERKENNY ARMY DEPOT PHASE II PARCELS - RECORD OF DECISION

MK01|O:\02281016.008\PHASE II\ROD\ROD_ATTACHMENT 3.DOC FINAL 3-5 

Table 3-1 

Phase II Parcels and Associated Monitoring Wells for Determining Excavation Limits, 

Letterkenny Army Depot, 

Chambersburg, PA 

(Continued) 

Minimum Depth-to-Water (ft TOC) Required 

for Various Excavation Depths 

(See Explanation Belowa) 

Parcel ID Well(s) 

Top of 

Casing 

Elevation 

(ft msl) 

Ground 

Elevation 

(ft msl) 

Casing 

Stick-Up 

(ft) 8 ft 7 ft 6 ft 5 ft 4 ft 3 ft 

2R-80 (Coffey) 100 ft 

2R-81 (Michigan) 

83-1 687.4 684.1 3.3 14.3 13.3 12.3 11.3 10.3 9.3 

2R-82 (California) 96-37-16 693.52 690.45 3.07 14.07 13.07 12.07 11.07 10.07 9.07 

2R-83 (Overcash) 97-37-18 683.52 684.71 -1.19 9.81 8.81 7.81 6.81 5.81 4.81 

2R-84 (Texas & 00-SE-1 (T) N/A N/A N/A N/A N/A N/A N/A N/A N/A 

Wash.) 83-12 (W) 688.0 685.1 2.9 13.9 12.9 11.9 10.9 9.9 8.9 

2R-85 (Oregon) Depth to seasonally high groundwater is greater than 11 ft bgs in this area.b

2R-86 (Carbaugh Ave.) 98-PDO-5 668.22 668.88 -0.66 10.34 9.34 8.34 7.34 6.34 5.34 

00-PD0-5 (N) N/A N/A N/A N/A N/A N/A N/A N/A N/A 2R-87 (Penn. Ave.) 98-PDO-5 (S) 668.22 668.88 -0.66 10.34 9.34 8.34 7.34 6.34 5.34 

2R-88 (Vehicle Rd.) Depth to seasonally high groundwater is greater than 11 ft bgs in this area.b

a For example, if the excavation depth is planned for 4 ft, then the depth to groundwater that is measured from the top of 

the monitor well casing has to be equal to or greater than the measurement shown above (in feet). If this criterion is not 

met, then the Army must be notified and a HASP must be implemented and 40-hour trained OSHA workers must be 

used. The allowable excavation depths shown in these columns include a 3-ft buffer zone between the bottom of the 

excavation and the top of the groundwater table. 

b Groundwater is deeper than the property transfer depth of 8 ft plus the 3-ft buffer zone, thus, there should not be a 

concern if excavating at any depth up to 8 ft bgs. 

bgs = Below ground surface. 

ft = Feet 

HASP = Health and Safety Plan. 

msl = Mean sea level. 

N/A = Denotes well(s) to be installed in 2001. 
T

TEXAS AVENUE

NEW YORK AVENUE

MICHIGAN AVENUE

OPEN STORAGE

WOODEN TENT PADS

PAVED PARKING

TEXAS AVENUE

CARBAUGH AVENUE CARBAUGH AVENUE

COFFEY AVENUE

APPROACH - DEPARTURE

ZONE

TAKEOFF - SAFETY

ZONE

TAKEOFF - SAFETY

ZONE

SAFETY

ZONE

(HELIPORT)

TAKEOFF

APPROACH - DEPARTURE ZONE

S-2284

S-2285

S-3292

T3254

S-2266

S-2286

T3255

3244 3245

S-3297 S-3296

3290

3243

S-3295

S-3293

S-3291

S-3296

S-3294

2291

MICHIGAN AVENUE

ARKANSAS AVENUE

OKLAHOMA AVENUE

CALIFORNIA AVENUE

NEW MEXICO

CALIFORNIA AVENUE

AVENUE

OVERCASH AVENUE

INDIANA AVENUE

OREGON AVENUE

ILLINOIS AVENUE

NEW MEXICO AVENUE

KANSAS AVENUE

TEXAS AVENUE

OVERCASH AVENUE

INDIANA AVENUE

ILLINOIS AVENUE

TEXAS AVENUE

OKLAHOMA AVENUE

KANSAS AVENUE

WASHINGTON AVENUE

EAST PATROL ROAD

WESTERN MARYLAND RAILROAD

IDAHO AVENUE

Feet t

u. S, ArMy Corps of Eng I neers

Bo.ltlMore District

Drainage Divide

Groundwater Level

Monitoring Well Location

for the Phase II BRAe Parcels

0 900

Roads

_ _ Dashed portions of the

road parcels are located in

the Enclave area and will not

be transferred. Public access to

these roads will be permitted.

_ Road Parcel

Buildings

Enclave Area

Letterkenny Army Depot

Chambersburg, PA

Figure 3-3

Well Locations for Groundwater

Level Monitoring Within Phase II

Roadway Parcels at LEAD

-,-

2R-86 = Phase II Parcel ID

Oregon(Opportunity) = LEAD Road Name

(LIDA Designated Road Name)

Legend:

Building 301

GATE 6

TEXAS/WASHINGTON (INNOVATION)

(TECHNOLOGY)

~"'1,-__J-'Building 245

GATE 5

Building 511 ~'"

FSWC6 q:\letter\army\BRAC_roads_2-3.dwg OS/23/2001