Superfund Record of Decision Aberdeen Proving Ground Carroll Island Edgewood Area Operable Unit a Aberdeen Proving Ground MD


                                    EPA/ROD/R03-96/229
                                    1996
EPA Superfund
     Record of Decision:
     ABERDEEN PROVING GROUND (EDGEWOOD AREA)
     EPA ID: MD2210020036
     OU09
     EDGEWOOD, MD
     09/30/1996

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                            CARROLL ISLAND
              ABERDEEN PROVING GROUND,  MARYLAND

                    RECORD OF  DECISION
                     OPERABLE  UNIT A
                        Submitted  to

                  Environmental  Conservation and
                     Restoration  Division
                Aberdeen Proving  Ground, Maryland 21010
                     September  1996

In accordance with Army Regulation 200-2,  this document is intended to
  comply with the National Environmental Policy Act (NEPA) of 1969.

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                                            CONTENTS

LIST OF FIGURES	iv

LIST OF TABLES	iv

ACRONYMS AND ABBREVIATIONS 	 V

1. DECLARATION OF THE RECORD OF DECISION	1-1
   1.1 SITE NAME AND LOCATION	1-1
   1.2 STATEMENT OF BASIS AND PURPOSE	1-1
   1.3 ASSESSMENT OF SITE	1-1
   1-4 DESCRIPTION OF SELECTED REMEDY 	  1-1
   1-5 STATUTORY DETERMINATION 	 1-2

2. DECISION SUMMARY	2-1
   2.1 SITE NAME,  LOCATION,  AND DESCRIPTION	2-1
   2.2 SITE HISTORY AND ENFORCEMENT ACTIVITIES 	 2-1
      2.2.1 Site History	2-1
      2.2.2 Enforcement Activities	2-3
   2.3 HIGHLIGHTS OF COMMUNITY PARTICIPATION 	 2-4
   2.4 SCOPE AND ROLE OF OPERABLE UNIT A	2-4
   2.5 SUMMARY OF SITE CHARACTERISTICS	2-5
   2.6 SUMMARY OF SITE RISKS	2-5
   2.7 DESCRIPTION OF ALTERNATIVES	2-7
      2.7.1 Alternative 1: No Action	2-7
      2.7.2 Alternative 2: Hand Excavation and Disposal/Treatment of Excavated
           Material	2-7
      2.7.3 Alternative 3: Conventional Excavation in an Armored Filtered Air Shelter
           and Disposal/Treatment of Excavated Material 	 2-8
      2.7.4 Alternative 4: Telerobotic Excavation in an Armored Filtered Air Shelter
           and Disposal/Treatment of Excavated Material 	 2-9
   2.8 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES	2-10
      2.8.1 Threshold Criteria 	  2-10
      2.8.2 Primary Balancing Criteria 	  2-13
      2.8.3 Modifying Criteria 	 2-14
   2.9 SELECTED REMEDY	2-14
   2.10 PERFORMANCE STANDARDS	2-15
   2.11 STATUTORY DETERMINATION	2-15
         2.11.1 Protection of Human Health and the Environment 	  2-16
        2.11.2 Compliance With ARARs	2-16
              2.11.2.1 Chemical-Specific ARARs 	 2-16
              2.11.2.2 Location-Specific ARARs 	 2-16
              2.11.2.3 Action-Specific ARARs 	 2-21
        2.11.3 Cost Effectiveness 	  2-24
        2.11.4 Use of Permanent Solutions and Alternative Treatment Technologies or
              Resource Recovery Technologies to the Maximum Extent Practicable 	 2-24
        2.11.5 Preference for Treatment as a Principal Element 	 2-24
   2.12 DOCUMENTATION OF SIGNIFICANT CHANGES	2-25

3. RESPONSIVENESS SUMMARY	3-1

4. REFERENCES	4-1


                                                   LIST OF FIGURES

Fig. 1. General Locations of Sites Evaluated in the FFS for Carroll Island	2-2


                                            LIST OF TABLES

TABLE 2-1 USEPA Evaluation criteria for Remedial (Cleanup) Alternatives  	  2-11
TABLE 2-2 Comparison of Remedial Action Alternatives	2-12
TABLE 2-3 Cost Summary for alternative 2	2-17

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1. DECLARATION OF THE RECORD OF DECISION

1.1 SITE NAME AND LOCATION

Carroll Island, Operable Unit A, Edgewood Area, Aberdeen Proving Ground (APG), Maryland.

1.2 STATEMENT OF BASIS AND PURPOSE

This Record of Decision (ROD) document presents the selected remedial action to reduce the risks posed by
the disposal pits/area in 13 sites and Areas of Concern (AOCs) located at Carroll Island in the Edgewood Area
of APG, Maryland. These 13 disposal pits/ areas are designated as Operable Unit A. The remedial action is
chosen in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act of 1980
(CERCLA), as amended by the Superfund Amendments and Reauthorization Act (SARA) of
1986, and, to the extent practicable, with the National Oil and Hazardous Substances Pollution Contingency
Plan (NCP). The information supporting the decisions on the selected remedy is contained in the
administrative record. Section 2.2 lists the documents contained in the administrative record.

The U.S. Environmental Protection Agency (USEPA) and the Maryland Department of the Environment (MDE)
concur with the selected remedy.

1.3 ASSESSMENT OF SITE

Actual or threatened releases of hazardous substance from these sites, if not addressed by implementing
the remedial action selected in this ROD, may present an imminent and substantial endangerment to public
health, welfare, or the environment.

1.4 DESCRIPTION OF SELECTED REMEDY

The cleanup of Operable Unit A is part of a comprehensive environmental investigation and remediation
currently being performed at APG under the CERCLA program. APG is divided into 13 study areas that include 55
sites that represent potential sources of contamination.

Carroll Island has 32 sites and AOCs, 13 of which contain disposal pits/areas. The 13 disposal pits/areas
are designated as Operable Unit A and potentially contain chemical warfare material (CWM) or other hazardous
substances. The disposal pits/areas are located at the following sites and AOCs:

Lower Island Disposal Area (Site 1),
AOC Associated With Test Grid 1 (Site 3),
AOC Associated With Test Aerial Spray Grid (Site 6),
3-Quinuclidinylbenzilate (BZ) Test Burn Pit (Site 7),
Decontamination Pits (Site 8) ,
Edgewood Proving Ground Dump (Site 9),
Bengies Point Road Dump (Site 10),
Service Area (Site 13) ,
AOC Associated With Service Area (Site 13),
Old Carroll Island Road Dump (Site 19),
Test Grid 1 Disposal Area (Site 21),
Woods South of Wind Tunnel Road (AOC), and
Animal Shelter Woods (AOC).

The removal and disposal or treatment of the entire volume of waste in the disposal pits/areas addresses
the principal threat to human health and the environment at Operable Unit A of Carroll Island by removing
source materials and eliminating the potential release of contaminants to the environment. This is the first
of two operable units, the rest of Carroll Island will be addressed by a separate Operable Unit.

The major components of the selected remedy for Operable Unit A include:

! hand excavation of the waste in the disposal pits/areas and
! segregation and disposal or treatment of excavated waste.

1.5 STATUTORY DETERMINATION

The selected remedy is protective of human health and the environment, complies with federal and state
reguirements that are legally applicable or relevant and appropriate reguirements (ARARs) to the remedial
action, and is cost-effective. The remedy uses permanent solutions and alternative treatment technologies to
the maximum extent practicable. The selected remedy meets the statutory preference for treatment.

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2. DECISION SUMMARY

2.1 SITE NAME, LOCATION, AND DESCRIPTION

Carroll Island is located in the westernmost portion of the Edgewood Area of APG in Baltimore County,
Maryland (see Fig. 1). It is located approximately 1 mile south of Gunpowder Falls State Park and is
separated from the rest of the Edgewood Area by the Gunpowder River. The closest residents are located on
Beach Road, approximately 0.5 miles from Carroll Island; the community of Carrollwood Manor is approximately
1.5 miles away.

Carroll Island encompasses approximately 855 acres, of which 680 are classifiable wetlands. It is bounded
by Seneca and Saltpeter Creeks, the Gunpowder River, and Chesapeake Bay. Portions of its shoreline are
subject to severe storm surge and wave erosion. Because the peak elevation at Carroll Island is only 13 ft
above mean sea level and much of the island is less than 10 ft above mean sea level, extensive areas are
subject to flooding and sediment transport.

Structures on the island include paved and gravel roads, a riprap erosion control berm, the remains of
two iron test towers, a small building, and numerous concrete pads (several of which are building
foundations). Access to Carroll Island is strictly controlled by military police patrols and other physical
measures.

2.2 SITE HISTORY AND ENFORCEMENT ACTIVITIES

2.2.1 Site History

Carroll Island was acguired by the U.S. Army in 1918 as part of the original Edgewood Arsenal.
Documentation on the use of Carroll Island before the 1940s is limited, but there is no evidence of U.S. Army
activity during this period.

In 1944, the U.S. Army reportedly used Carroll Point and the area north of Lower Island Point to test
white phosphorus (a smoke munition) and high explosive ordnance. Also, a large field on the northeastern part
of Carroll Island was cleared during the latter part of that decade and, along with other parts of the
island, used as a CWM test area. Nerve and blister agents were released at the test area through 1969; riot
control exercises and smoke-producing and simulant materials testing were conducted through 1971.

Waste from testing activities was discarded via dumping or burial on the island. In 1975, the CWM testing
facilities at Carroll Island were decommissioned [U.S. Army Environmental Hygiene Agency (USAEHA) 1989].

2.2.2 Enforcement Activities

From 1984 to 1985, APG was evaluated as a potential National Priorities List (NPL) site under CERCLA
(USEPA 1985) . In 1985, the Edgewood Area of APG was proposed for inclusion on the NPL; it was listed on the
NPL in 1990. In 1986, between the time of the proposed listing and the final listing, a Resource Conservation
and Recovery Act (RCRA) corrective action permit (MD3-21-002-1355) was issued by USEPA Region III to address
solid waste management units (SWMUs) in the Edgewood and Aberdeen Areas of APG. As part of
the RCRA permit, USAEHA performed a RCRA Facility Assessment (RFA) study for the Edgewood Area. Fifteen sites
were identified as either SWMUs or areas with potential prior releases (USAEHA 1989) . In addition to the RFA,
the RCRA permit reguired that a RCRA Facility Investigation (RFI) be performed at Carroll Island. However,
because of the final listing of the Edgewood Area on the NPL in 1990, the RFI was not completed. Further
investigations at Carroll Island were to be performed under CERCLA.

In 1986, before the Edgewood Area was on the NPL list, the U.S. Geological Survey (USGS), in cooperation
with the U.S. Army, conducted a hydrogeologic assessment of Carroll Island. A remedial investigation (RI) for
Carroll Island was initiated in 1991 to determine the nature and extent of contamination of the sites. The
RI did not detect contaminants migrating from Operable Unit A to the surrounding environment. However, the
potential of contaminant migration from the Operable Unit A disposal pits/areas to groundwater, soil, surface
water, and sediment exists as long as the wastes remain buried on Carroll Island. Therefore, the ongoing RI
recommended that Operable Unit A be addressed in a Focused Feasibility Study (FFS). The FFS for Operable Unit
A identified and evaluated alternatives to remediate the disposal pits/areas presented in this ROD. The
Proposed Plan for Operable Unit A presented
the alternatives and the recommended remedial alternative (APG 1996) .

In 1993, an interim remedial action was performed at the Lower Island Disposal Area (Site 1). This action

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included the removal of the contents of an open pit.

    The following documents provide details of the site investigations and assessments of cleanup actions for
Operable Unit A.

!  USAEHA,  1989. RCRA Facility Assessment Report, Edgewood Area, Aberdeen Proving
   Ground, Maryland, for the U.S. Army environmental Hygiene Agency, Aberdeen Proving
   Ground, Maryland, Report No. DRXTH-AS-FR-82185.
!  USGS,  1991.  Hydrogeologic Data Report for Carroll  Island, Aberdeen  Proving Ground,
   Maryland, Open File Report 89-388, 1991.
!  APG, 1994. The Remediation of Carroll Island Lower  Island Disposal  Site, Aberdeen
   Proving Ground,  Maryland, Technical Report,  January 1994.
!  APG, 1995. Focused Feasibility Study, Operable Unit A, Carroll  Island, Aberdeen
   Proving Ground,  Edgewood, Maryland, December 1995.

!  APG, 1996. Proposed Plan for Operable Unit A, Disposal Pits, Carroll  Island, Aberdeen
   Proving Ground,  Maryland, July 1996.

2.3 HIGHLIGHTS OF COMMUNITY PARTICIPATION

    The Proposed Plan for Operable Unit A was released to the public in July 1996 at the four information
repositories listed below:

!  Harford  County Public Library, Aberdeen Branch,
!  Harford  County Public Library, Edgewood Branch,
!  Miller Library at Washington College, Chestertown,  and
!  Baltimore County Department of Environmental Protection, Towson.

    The notice of availability of these documents was published on July, 1996,  in four newspapers:  The Cecil
Whig, Kent County News,  The Avenue,  and The Aegis.  A public comment period was held from July 15 through
August 29, 1996. A fact sheet that contained a summary of the Proposed Plan was distributed to approximately
2,600 residents around the area.  In addition, a public meeting was held at Oliver Beach Elementary School on
August 21, 1996, to inform the public about the preferred remedial alternative for Carroll Island and to seek
public comments. At this meeting, representatives from the U.S. Army, USEPA, and MDE answered guestions about
the site and remedial alternatives under consideration. Responses to the comments received during this period
are included in the Responsiveness Summary in Sect. 3 of this document.

2.4 SCOPE AND ROLE OF OPERABLE UNIT A

    Carroll Island represents one component of a comprehensive environmental investigation and cleanup
presently being performed at APG. Carroll Island is divided into two Operable Units (A and B). Operable Unit
A addresses 13 disposal pits/areas at Carroll Island while Operable Unit B addresses the rest of the island.
A Feasibility Study is currently being conducted on Operable Unit B.

    The disposal pits/areas in Operable Unit A pose a threat to human health and the environment because of
the potential risk of migration of wastes from these sites to groundwater, soil, surface water, or sediment.
The purpose of the remedial action is to prevent future environmental impacts as a result of the  migration
of contaminants to areas where humans and environmental receptors may be exposed.

2.5 SUMMARY OF SITE CHARACTERISTICS

    Numerous sites and features at Carroll Island have been investigated as part of RI activities. Based on
historical information,  visual site inspections,  and geophysical surveys  (to detect ferrous metals and
disturbed soil indicative of buried wastes),  the 13 disposal pits/areas were identified as reguiring remedial
action.

    Although results of the RI work suggest no contaminants have yet migrated from these disposal pits/areas
to the surrounding environment, there is the potential for contaminant migration, as waste in the pits breaks
down or is exposed from erosion or other surface disturbance such as flooding.   Contaminants that may be
contained in the pits include CWM,  agent degradation products  (e.g., methylphosphonic acid), explosives,
volatile organic compounds  (VOCs),  semivolatile organic compounds  (SVOCs), pesticides/polychlorinated
biphenyls (PCBs),  and inorganics. These materials could adversely affect site workers, nearby residents,
trespassers, and recreational visitors if exposed.

    The total volume of waste in the 13 disposal pits/areas is approximately 12,420 cubic yards, as estimated
through visual observation and geophysical surveys. The disposal pits/areas cover a total area of about 1.9
acres and are believed to extend to an average depth of 3.3 ft.

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2.6 SUMMARY OF SITE RISKS

A quantitative Risk Assessment (RA) was not conducted for the individual pits/area because data were not
collected. The data were not collected because of the potential hazards associated with the pits. However, a
qualitative RA was conducted to analyze the major concerns associated with the disposal pits/areas, potential
contaminants, potential receptors, and exposure pathways.

Siqnificant risks or hazards to human health and the environment exist if the contents of the disposal
pits/areas are exposed or transported to the Chesapeake Bay and surroundinq water bodies. This determination
is based on historical information concerninq the contents of the disposal pits/areas, the hiqh toxicity of
some of the potential contaminants, the diverse array of potential human and ecoloqical receptors, and the
numerous potential exposure pathways.

! Major concerns Althouqh the investiqation results for these sites indicate contaminants
from the disposal pits/ areas have not miqrated to the surroundinq qroundwater, soil
surface water, or sediment, such miqration may occur followinq the breakdown of waste in
the pits. In addition, the potential for shoreline erosion at some of these sites, and for
shallow qroundwater and surface floodinq at all sites, may expose wastes and transport the
contents to the surroundinq areas-includinq surface water bodies and the Chesapeake Bay.

! Potential contaminants Based on the information available, contaminants that could
potentially be released from the disposal pits/areas include CWM, CWM deqradation
products, explosives, VOCs, SVOCs, pesticides/PCBs, and inorqanics. In addition,
munition fraqments, munitions, debris, and scrap metal may be exposed. The potential
effects of these contaminants are dependent on the specific chemical, route of exposure,
and exposure point concentration.

! Potential receptors and exposure pathways The major concern with the disposal pits/
areas is potential exposure to receptors if the contaminants are exposed or transported to
the surroundinq environment and the Chesapeake Bay. If such exposure occurs, potential
human receptors may include outdoor maintenance workers, security workers,
construction/excavation workers, nearby off-site residents, nearshore fishermen, consumers
of fish cauqht near Carroll Island, hunters and trappers, consumers of qame from Carroll
Island, nearshore swimmers, and trespassers or visitors.

These potential receptors may be exposed to contamination via incidental inqestion or
direct dermal contact with soil, surface water, sediment, or exposed wastes. Consumers of
fish and qame from Carroll Island may be exposed to contaminants that bioconcentrate in
fish or qame tissue. In addition, chemical releases to the air-includinq CWM- exposes
receptors via inhalation.

! Environmental receptors Environmental receptors are present at, and in the vicinity of,
Carroll Island. The variety of habitats found on the island includes upland forest,
wetlands, ephemeral ponds, and the surroundinq estuaries with tidal wetlands. Carroll
Island is surrounded by the Gunpowder River, Saltpeter Creek, Seneca Creek, and the
Chesapeake Bay. A diverse array of mammals, birds, plants, fish, and invertebrates are
found at and in the vicinity of Carroll Island. These ecoloqical species could be exposed to
contamination via inqestion of contaminated media, uptake via roots and foliaqe (plants),
respiration of chemicals in surface water/sediment (fish), or direct dermal contact with
contaminated media. In addition, they may be exposed via accumulation of contaminants
in the food web.

2.7 DESCRIPTIONS OF ALTERNATIVES

The U.S. Army considered a ranqe of alternatives for remediatinq the disposal pits/areas at Operable Unit
A. The followinq alternatives were evaluated.

! Alternative 1 No action.
! Alternative 2 Hand excavation and disposal/treatment of excavated material.
! Alternative 3 Conventional excavation in an armored filtered air shelter and
disposal/treatment of excavated material.
! Alternative 4 Telerobotic excavation in a an armored filtered air shelter and
disposal/treatment of excavated material.

2.7.1 Alternative 1: No Action

The no action alternative involves no remedial actions to contain, remove, or treat the waste in the

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disposal pits/areas. In the long term it will not be protective of human health and the environment. It is
evaluated to provide a baseline against which to compare all other alternatives.

With respect to ARARs, this alternative does not meet RCRA reguirements for general closure [Code of
Maryland Regulations (COMAR) 26.13.05.07] or for closure of a landfill (COMAR 26.13.05.14).

2.7.2 Alternative 2: Hand Excavation and Disposal/Treatment of Excavated Material

This alternative includes the following activities.

! Clearance of unexploded ordnance (UXO) from the disposal pits/areas before and during excavation.
! Clearing and grubbing disposal pits/areas.
! Excavation of disposal pits/areas (estimated total of 12,420 cubic yards) with hand tools
and eguipment.
! Segregation of waste into soil, debris, and rubble fractions.
! Characterization and disposal or treatment of excavated material. Waste is disposed of in
accordance with APG protocol and federal and state regulations.
! At least sites, where feasible, excavated disposal pits/areas will be left open to create
wildlife habitat enhancement ponds; otherwise, the pits will be backfilled using clean
material from grading operations at other sites

The following major ARARs are cited for Alternative 2. A complete list of all ARARs are cited listed in
Section 2.11.2.

! Excavation is performed in accordance with Maryland Erosion and Sediment Control
Regulations (COMAR 26.17.01). Dust suppression technigues are incorporated to
minimize the airborne transport of contaminated dust.
! If excavated material is hazardous, it is handled as a hazardous waste in accordance with
Maryland Regulations for Identifications and Listing of Hazardous Waste (COMAR 26.13.02).

Assuming that 30% of the soil fraction is hazardous, the costs for Alternative 2 are estimated as
follows:

! Capitol cost: $11,641,102
! Operation and maintenance (O&M) cost: none
! Net present worth: $11,641,102

The estimate time to implement this year is one year.

2.7.3 Alternative 3: Conventional Excavation in an Armored Filtered Air Shelter and
Disposal/Treatment of Excavated Material

This alternative includes the following activities.

! Clearance of UXO from the disposal pits/areas before and during excavation.
! Clearing and grubbing of disposal pits/areas.
! Conventional (backhoe/mechanical eguipment) excavation of the entire volume of waste in
the disposal pits/areas (estimated total of 12,420 cubic yards) within an armored filtered air
shelter. (The shelter will be tested after assembly, but prior to use, to ensure harmful
materials will not escape. Real-time air monitoring will be used to confirm the
protectiveness of the air shelter.)
! Segregation of waste into soil, debris, and rubble fractions.
! Characterization and disposal or treatment of excavated material. Waste is disposed of in
accordance with APG protocol and federal and state regulations.
! At selected sites, where feasible, excavated disposal pits/ areas will be left open to create
wildlife habitat enhancement ponds; otherwise, the pits will be backfilled using clean
material from grading operations at other sites. (Excess clean fill material will be spread
out at upland areas of Carroll Island.)

The following major ARARs are cited for Alternative 3.

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Assuming that 30% of the soil fraction is hazardous, the costs for Alternative 3 are estimated as
follows:

! Capital cost: $12,470,137
! O&M cost: none
! Net present worth: equal to capitol cost.

The estimated time to implement this action is twenty-six months.

2.7.4 Alternative 4: Telerobotic Excavation in an Armored Filtered Air Shelter and
Disposal/Treatment of Excavated Material

This alternative includes the following activities.

! Clearance of UXO from the disposal pits/areas before and during excavation.
! Clearing and grubbing of disposal pits/areas.
! Telerobotic excavation of the entire volume of waste in the disposal pits/areas (estimated
total of 12,240 cubic yards) within an armored filtered air shelter. (The shelter will be
time air monitoring will be used to confirm the protectiveness of the air shelter.)
! Segregation of waste into soil, debris, and rubble fractions.
! Characterization and disposal or treatment of excavated material. All waste will be
disposed of in accordance with APG protocol and federal and state regulations.
! At selected sites, where feasible, excavated disposal pits/areas will be left open to create
wildlife habitat enhancement ponds; otherwise, the pits will be backfilled using clean
material from grading operations at other sites. (Excess clean fill material will be spread
out at upland areas of Carroll Island.)

The following major ARARs are cited for Alternative 4.

! Excavation is performed in accordance with Maryland Erosion and Sediment Control
Regulations (COMAR 26.17.01). Dust suppression techniques are incorporated to
minimize the airborne transport of contaminated dust.
! If excavated material is hazardous, it is handled as a hazardous waste in accordance with
Maryland Regulations for Identification and Listing of Hazardous Waste (COMAR 26.13.02).

Assuming that 30% of the excavated soil is hazardous, the costs for Alternative 4 are estimated as
follows:

! Capitol cost: $13,325,325
! O&M cost: none
! Net present worth: equal to capital cost.

The estimated time to implement this action is twenty-six months.

2.8 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES

As required by CERCLA, for each disposal pit/area at Operable Unit A, the four remedial alternatives were
evaluated using the nine criteria specified by USEPA (Table 2-1). This section and Table 2-2 summarize the
relative performance of each alternative.

2.8.1 Threshold Criteria

! Overall protection of human health and the environment Alternative 2 (hand
excavation and disposal/treatment of excavated material) provides overall protection of
human health and the environment because it removes the sources of contamination at
Operable Unit A disposal pits/areas. It also reduces the risk of an uncontrolled release of
contaminants to the environment during removal activities by requiring that removal of the
waste be conducted using hand excavation tools. Of the four alternatives evaluated,
Alternative 2 provides the greatest level of protection to human health and the environment
although there are short-term risks during excavation and handling. This alternative
removes the potential sources of contamination at the disposal pits/areas and reduces the
potential risk of release of contaminants to the environment.

Alternative 4 (telerobotic excavation inside an armored filtered air shelter and disposal/
treatment of excavated material) provides overall protection of human health and the
environment because it removes the potential sources of contamination at Operable Unit A
disposal pits/areas. The armored filtered air shelter shields workers from an uncontrolled

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release of contaminants and prevents the potential migration of contaminants to the
environment outside the shelter. However, Alternative 4, overall,  is less protective of
human health and the environment than Alternative 2 because the use of a hydraulic
excavator increases the risk of rupturing/detonating UXO, UXO filled with CWM,  or other
items containing CWM or other chemicals.

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TABLE 2-1.

USEPA Evaluation Criteria for Remedial (Cleanup) Alternatives

Overall protection of human health and the environment
Addresses whether a cleanup method adequately protects human health and the environment and
describes how risks presented by each pathway are eliminated, reduced, or controlled through
treatment, engineering controls, or institutional controls.
Compliance with ARARs
Addresses whether a cleanup method meets all ARARs (federal and state environmental reguirements)
and provides grounds for invoking a waiver.
Long-term effectiveness and permanence
Refers to the ability of the cleanup method to reliably protect human and the environment over
time, after the action is completed.
Reduction of toxicity, mobility, or volume through treatment
Addresses the effectiveness of a cleanup method in reducing the toxicity, mobility, or volume of
hazardous substances through treatment.
Short-term effectiveness
Addresses the period of time needed to complete the cleanup, and any adverse impacts on human health
and the environment that may occur during construction and operation.
Implementability
Refers to the technical and administrative feasibility of a cleanup method, including the
availability of required materials and services.
Cost
Includes the estimated capital and O&M costs of each cleanup method.
State acceptance
Indicates whether the State of Maryland agrees with the preferred cleanup method.
Community acceptance
Indicates whether public concerns are addresses by the cleanup method and whether the community has
a preference. (Public comment is an important part of the final decision.)

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                                         TABLE 2-2

              Comparison  of  Remedial  Action Alternatives
                                                            Evaluation Criteria
    Remedial Alternative

Alternative 1
Conventional Excavation in
an Armored Filtered Air
Shelter and Disposal/
Treatment of Excavated
Material
Alternative 4

Telerobotic Excavation in an
Armored Filtered Air Shelter
and Disposal/Treatment of
Excavated Material
          Does  not provide adequate
          protection or meet remedial
          action obj ectives
          Offers high level of
          protection to the immediate
          environment;  reduces
          potential for UXO/CWM
incidents by hand
          excavation
          Offers high level of
          protection to the immediate
environment; reduces
          potential for off-site
          contamination by use of
          armored filtered air shelter

          Offers high level of
          protection to the immediate
          environment;  reduces
          potential for off-site
contamination by use of
armored filtered air shelter
                                           Compliance
                                                 With           Long-Term
                                                ARARs      Effectiveness  and
                                                   Permanence
                                                 Does not reduce risks
                                                                                                                                                             Short-Term Effectiveness
                                                                                                                                               Has  no impacts on community
                                                                                                                                                        or worker health  or  the
                                                                                                                                               environment                     disposal
                                                                                                                                                        Moderately  increases short-
                                                                                                                                               term noise  and dust;  reduces    equipment  that
                                                                                                                                                     risk  of  CWM release by hand
                                                                                                                                                        excavation
                                                                                                                                                                                                Implementability
                                                                                                                                                                                                                                           Capitol
             Moderately increases short-
   term noise and dust; provides    equipment that are
  Ln  case  of  accidental   available; uses specialized
             release  of CWM through use of    equipment  that  could delay
           armored filtered air  shelter       implementation
             Moderately increases short-               Requires labor and
   term noise and dust; provides    equipment that are readily     (no O&M)
protection in case of  accidental    available;  uses specialized
             release  of CWM through use of   equipment that  could delay
   armored filtered air shelter;    implementation
   increases level of protection to
             on-site  workers via telerobotic
             excavator

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Alternative 3 (conventional excavation in an armored filtered air shelter and
disposal/treatment of excavated material) provides overall protection of human
health and the environment because it removes the potential source of
contamination at Operable Unit A disposal pits/areas and because excavation
activities are conducted within a blast containment and air filtering system. In the
event of an uncontrolled release of contaminants during excavation activities, the
shelter prevents the migration of contaminants to the outside environment.
However, because Alternative 3 reguires workers to be inside the shelter during
excavation activities, it is less protective of worker health and safety than either
Alternative 2 or Alternative 4.

Alternative 1 (no action) is not protective of human health and the environment
because it does not remove the wastes from the disposal pits/areas.

! Achievement of ARARs All three excavation and disposal or treatment
alternatives (i.e., Alternative 2, 3, and 4) comply with all ARARs. Alternative 1
(no action) does not comply with ARARs.

2.8.2 Primary Balancing Criteria

! Long-term effectiveness Alternatives 2, 3, and 4 provide the same degree of
long-term effectiveness and permanence because the contents of the disposal pits/
areas are permanently removed from the site, thus eliminating the potential for
human exposure to waste or leaching of contaminants to groundwater or surface
water. Any waste not reclaimed or treated is placed in a permitted disposal
facility. Alternative 1 is the least effective over the long term.
! Reduction in toxicity, mobility, or volume of contaminants Alternative 2, 3,
and 4 reduce the toxicity, mobility, and volume of the waste because it is
excavated and removed from the site then treated or placed in a permitted disposal
facility. Alternative 1 does not achieve these objectives.
! Short-term effectiveness Alternative 2 is the most protective of the surrounding
communities and workers involved in the cleanup because it reduces the risk of an
uncontrolled release of contaminants to the environment by hand excavation of the
disposal pits/areas. Alternatives 3 and 4 mitigate the risk of exposure from a
release but increase the risk of release. Alternative 1 provides less short-term
effectiveness.
! Implementability Alternative 1 is the easiest alternative to implement.
Alternative 2 achieves a high level of protection for human health and the
environment in the shortest time of any of the excavation alternatives. No major
implementation considerations are associated with Alternative 2 (hand excavation).
The use of an armored filtered air shelter in Alternatives 3 and 4 reguires the
implementation of engineering controls and testing certification of the eguipment
and structures. Additionally, as an innovative technology, the telerobotic
excavator proposed for Alternative 4 reguires additional testing and certification
before implementation.
! Cost Because no O&M costs are associated with Alternatives 1, 2, 3, or 4, the
capital cost for each alternative is egual to the net present worth. Alternative 1 has
a capital cost of $0; Alternative 2, $11,641,102; Alternative 3, $12,470,137; and
Alternative 4, $13,325,325. Cost estimates were based on professional judgement
that 30% of the waste is hazardous.

2.8.3 Modifying Criteria

! State acceptance The State of Maryland concurs with the selected alternative.

! Public acceptance APG solicited input from the public on the development of
alternatives and on the alternatives identified in the Proposed Plan. The public is
in agreement with the cleanup objectives and the preferred alternative. A detailed
summary of concerns and APG's responses are contained in Section 3.0.

2.9 SELECTED REMEDY

The selected remedy for cleanup of the Operable Unit A disposal pits/areas is Alternative 2 (hand
excavation and treatment or disposal of excavated material). This alternative is protective of human health
and the environment; complies with all ARARs; has a high degree of long-term effectiveness and permanence;
and reduces the toxicity, mobility, and volume of wastes to be disposed of through segregation, treatment,
and reclamation to the maximum extent practicable. Although this alternative presents some short-term risks

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during excavation and handling, it is a demonstrated and easily implementable technology; and it is
significantly more cost-effective than the other excavation alternatives.

Alternative 2 involves removing the entire volume of waste in the disposal pits/areas using hand
excavation tools and eguipment. UXO support is reguired before and during excavation to locate and remove UXO
encountered during the removal of disposal pit/area contents. Each UXO sweep is performed in 2-ft lifts.
Embedded metallic objects are unearthed by hand. An excavator, backhoe, or similar mechanical
eguipment may be used in excavating surface soil that is free of metallic objects. CWM-filled containers or
UXO items are handled and disposed of by U.S. Army Technical Escort Unit in accordance with APG protocol.
Recovered UXO determined to be unsafe to store or move may be detonated on-site. Remedial activities include
real-time monitoring of air emissions for CWM.

The limit of excavation is initially established by visual observation. After all visual waste and debris
are removed, soil samples are collected and analyzed to determine if remediation goals have been achieved or
if additional excavation is reguired. Excavated material is separated into soil, debris, and rubble
fractions.

The soil fraction is screened for CWM, placed in roll-offs, and analyzed to determine if it is hazardous.
For the purpose of cost comparison, it is assumed that 30% of all excavated soil is hazardous and reguires
treatment.

All debris and rubble recovered during the excavation process are considered to be potentially
contaminated with CWM. For the purpose of this remedial action, debris is defined as metal, glass, and
plastic; rubble includes concrete, bricks, and wood. All collected debris and rubble are monitored for CWM.
All waste is then disposed of or treated in accordance with APG protocol and federal and state reguirements.

At some sites, it may be necessary to dewater excavated material, drain standing water (e.g., Bengies
Point Road Dump), or drain pooled water in the pits. Any such water is screened for CWM, tested, and disposed
of based on analytical results.

Where feasible, the cavities created by excavation are left open as part of habitat enhancement to
support establishment of natural resources. Areas that cannot feasibly be used for this purpose are
backfilled, compacted, graded, and seeded.

Alternative 2, as described herein, may reguire some modification as a result of the remedial design or
construction processes. Table 2-3 summarizes the costs for Alternative 2.

2.10 PERFORMANCE STANDARDS

The selected remedy for Operable Unit A involves removing the entire volume of waste from the pits and
disposing of the waste in accordance with applicable or relevant and appropriate Federal and state
reguirements. The initial limit of excavation is established by removing all visible waste and debris. Soil
excavation will continue until all contaminated soil is removed. Soil will be considered contaminated if
levels exceed (a) industrial risk-based concentrations for protection of human health or (b) ecological
screening criteria and background concentrations, or bioassays show an adverse impact.

2.11 STATUTORY DETERMINATION

The selected remedy satisfies the reguirements under Sect. 121 of CERCLA to:

! protect human health and the environment,
! comply with ARARs,
! be cost-effective,
! use permanent solutions and alternative treatment technologies or resource
recovery technologies to the maximum extent practicable, and
! satisfy the preference for treatment as a principal element.

2.11.1 Protection of Human Health and the Environment

The selected remedy, Alternative 2 (hand excavation and disposal/treatment of excavated material) ,
reduces the risks posed to human health and the environment through hand excavation and disposal or treatment
of the entire volume of waste in the disposal pits/areas. Alternative 2 is protective of the surrounding
environment because it removes the source of contamination. Additionally, Alternative 2 eliminates the
potential for surface water contamination as a result of erosion, flooding, or runoff.

Precautions are taken to ensure the safety of site workers, who wear appropriate personal protective
eguipment. Real-time air monitoring helps ensure workers are protected from exposure to unsafe levels of

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chemical vapor or dust. Dust and erosion control measures are implemented to minimize exposure to potentially
hazardous substances. This alternative will not pose any unacceptable short-term risks.

2.11.2 Compliance With ARARs

    The selected remedy, Alternative 2  (hand excavation and disposal/treatment of the excavated material),
complies with all chemical-, location-, and action-specific ARARs, as outlined below.

2.11.2.1 Chemical-Specific ARARs

!   Federal Toxic Substances Control Act  [15 USC 2605, Regulation of Hazardous
    Chemical Substances and Mixtures]
    - 40 (CFR)  761 (PCB requirements)
       If PCB-contaminated material is encountered during excavation activities,  it
       must be managed in accordance with federal disposal regulations (applicable).

2.11.2.2 Location-Specific ARARs

!   Federal Wetlands Regulations  [33 USC  1344  Permits for Dredged or Fill Material]
    - 40 CFR Part 6,  Appendix A, and Executive Orders 11988 and 11990 (Flood Plain or Wetlands)

    Excavation in 9 of the 13 disposal pits/areas is subject to USEPA standards.
    Construction activities at wetlands sites must be modified to minimize adverse
    impacts (applicable).

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                                               TABLE 2-3

                             Cost Summary for Alternative 2, Hand Excavation  and
                                   Disposal/Treatment of Excavated Material
                                  Carroll Island, Aberdeen  Proving Ground  (a)
               Item
Summary: 13 FFS Sites
SITE PREPARATION
UXO clearing
Cut and chip trees to 12-in. diameter
Grub stumps and remove
SUBTOTAL
SITE STAGING AND DECONTAMINATION AREA
UXO cleaning
Cut and       chip trees to 12-in.  diameter
Grub stumps and remove
Stabilize construction entrance
Grade berms, staging area
Geosynthetic liner
Filter fabric
Crushed stone
Decontamination water and holding tanks(2crews)
Characterize decontamination water
Dispose of decontamination water
SUBTOTAL
    Rate       ($)
 904.00  /day
 3,950.00 /acre
 2,500.00 /acre
 904.00/day
 3,950.00/acre
2,500.00/acre
 500.00/ea
 1.43/sy
 0.33/sf
 0.35/sf
 0.73/sf
202.38/day
 125.00/load
  1.80/gal
Quantity
    Cost 5% of
   Soil is Haz
Unit       1995  (&)
Quantity  Unit
13
2.01
2.01

11
1.1
1.1
11
5,324
47,916
47,916
47,916
166
13
13,000

day
acre
acre

day
acre
acre
ea
sy
sf
sf
sf
day
load
gal

11,752
7,940
5,025
24.717
9,944
4,345
2,750
5,500
7,613
15,812
16,771
34,979
33,595
1, 625
23,400
164.784
 Cost 30% of
Soil is Haz.
      1995  ($)
                                                                      11,752
                                                                      7,940
                                                                      5,025
                                                                    24.717

                                                                      9,944
                                                                      4,345
                                                                      2,750
                                                                      5,500
                                                                      7,613
                                                                    15,812
                                                                    16,771
                                                                    34,979
                                                                    33,595
                                                                      1,625
                                                                    23,400
                                                                    164.784

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                                                           TABLE 2-3   (Cont'd)
               Item
EXCAVATION OF WASTE
UXO clearing
Sediment and erosion control
Mechanical excavation of 1st foot
Excavation, hand tools  (2 crews)
Load rubble, debris, and soil into roll-offs/trucks
Haul rubble/debris and soil to central staging area
Post-excavation sampling
Dewatering equipment (2 crews)
Disposal of holding tank water
SUBTOTAL
DISPOSAL OF RUBBLE FRACTION
Transport and dispose of rubble at on-post landfill
SUBTOTAL
DISPOSAL OF SOIL FRACTION
Characterize excavated material
Transport and dispose of nonhazardous soil
Transport and treat hazardous soil
Characterize and dispose of hazardous ash
SUBTOTAL
DISPOSAL OF DEBRIS FRACTION
Transport debris by boat to ERDEC
Dispose of debris at ERDEC
SUBTOTAL
                                                                     Rate
                        ($)
             904.00 /day
              2.00 /If
      685.85  /day            15
             12,656.00/day
(2  crews)   1,371.70 /day
                3.31 /ton
             3,533.00 /ea
              395.46 /day
             2,575.00 /site
                2.26 /ton
            3,533.00  /ea
                2.19  /cy
               425.00  /ton
               296.78 /ton
       1,000.00  /week        34
       527.50 /ton         852


Quantity
13
11,369
day
166
166
15,532
216
166
13

1,400

96
10,029
790
123



Unit
day
If

day
day
ton
ea
day
site

ton

sample
cy
ton
tons

Cost 5% of
Soil is Haz
1995 ($)
11,752
22,738
10,288
2,100,896
227,702
51,532
763,128
65,646
33,475
3,287,036
3,164
3,164
339,168
21,964
335,750
36,504
733,385
week
ton
 34,000
449,430
     Quantity

       11,752
       22,738
10,288
    2,100,896
      227,702
       51,411
      763,128
       65,646
       33,475
     ,287,036

        3,164
        3,164

       339,168
         7,392
         4,755
           714
                                                            Cost 30% of
                                                              Soil is Haz.
                                                        Unit            1995  ($)
 34,000
449,430
                                                            cy
                                                            ton
                                                            ton
                                                           16,188
                                                        2,020,875
                                                          211,901
                                                        2,588,132
                                                                                                                 483,430
                                                                                       483,430

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                                                TABLE 2-3   (cont'd)
                 Item
DISPOSAL OF CWM
Punch, drain, and dispose of CWM-filled UXO
SUBTOTAL
CONSTRUCTION SUBTOTAL  (13 FFS Sites)
CENTRAL STAGING AREA
UXO clearing
Stabilize construction entrance
Grade berms, decon/staging area
Geosynthetic liner
Filter fabric
Crushed stone
Decontamination water and holding tanks
Characterize decontamination water
Transport decontamination water for disposal
Dispose of decontamination water
Panelize system building
Waste separation
Load soil into roll-offs/trucks for disposal
20-cy roll-off containers, drop off charge
20-cy roll-off containers, rental
Perimeter fence
Contractor/engineer trailers
Telephone, lights, HVAC, and portable toilet
Security
      Rate    ($)

   12,000.00   ea
                        Cost 5% of
                        Soil is Haz
                      Quanty  Unit
1995 ($)
   Cost 30% of
  Soil is Haz.
Quanty  Unit
   904.
   500.
     1,
     0,
     0.
     0.
   101.
   125.
   650.
     1,
59,100,
 1,589,
   695.
   500.
   480.
    15.
    14.
    39.
   367,
00 /day
00 /ea
43 /sy
33 /sf
35 /sf
73 /sf
19 /day
00 /load
00 /load
80 /gal
00 /is
60 /day
85 /day
00 /ea
00 /day
15 /If
67 /day
38 /day
20 /day
13 ea


1 day
1 ea
2,130 sy
19,167 sf
19,167 sf
19,167 sf
186 day
13 load
13 load
13,000 gal
1 ea
186 day
186 day
24 ea
186 day
563 If
186 day
186 day
186 day
156,000
156,000
4,852,516
904
500
3,046
6,325
6,708
13,992
18,821
1, 625
8,450
23,400
59,100
295,666
129,428
12,000
89,280
8,529
2,529
7,325
68,299
 1995 ($)

  156,000
  156,000
6,707,263
                                    904
                                    500
                                  3,046
                                  6,325
                                  6,708
                                 13,992
                                 18,821
                                  1, 625
                                  8,450
                                 23,400
                                 59,100
                                295,666
                                129,428
                                 12,000
                                 89,280
                                  8,529
                                  2,729
                                  7,325
                                 68,299

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                                                        TABLE 2-3 (cont'd)

                                                                                          Cost  5%  of                      Cost 30% of
                                                                                         Soil is Haz                     Soil is Haz.
                 Item                                         Rate   ($)        Quantity  Unit            1995  ($)      Quantity  Unit           1995  ($)
Meteorological station/monitoring                      7,500   ea           1    ea                  7,500                          7,500
Technical Escort Unit
Temporary bunker (portable magazine)                      10,000.00   ea           1    ea                 10,000                          10,000
Pier and waterway improvement                            265,000.00   Is           1    Is                265,000                         265,000
Closedown of waterway                                      1,200.00   ea           34    ea                40,800                          40,800
SUBTOTAL                                                                                               1,079,427                       1,079,427
CONSTRUCTION SUBTOTAL  (Central Staging Area)                                                           5,931,944                       7,786,690
Construction contingencies  (20%)                                                                        1,186,389                       1,557,338
Health and safety training and eguipment  (including air                                                  593,194                         778,669
monitoring and dust control eguipment) at 10%
TOTAL CONSTRUCTION COST                                                                                7,711,527                      10,122,698
Engineering and administration at 15%                                                                  1,156,729                       1,518,405
TOTAL CAPITOL COST                                                                                     8,868,256                      11,641,102

(a) ea  = each.
    sy  = sguare yard.
    sf  = sguare foot.
    gal = gallon.
    if        = linear foot.
    cy  = cubic yard.
    Is        = lump sum.

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!   Federal Conservation of Wildlife Resources
   - 50 CFR Part 402 (Endangered Species Act)
       If threatened and endangered species are identified during an ecological survey
       currently in progress at Carroll Island,  construction activities will be modified
       to minimize adverse impacts on the species (applicable).

!   Maryland Threatened and Endangered  Species Regulations
      COMAR 08.03.08 (Threatened and Endangered Species)
      If threatened and endangered species are identified during an ecological survey
      currently in progress at Carroll Island, construction activities will be modified
      to minimize adverse impacts on the species (applicable).

!   Maryland Water Resources Administration
   - COMAR 08.05.04 (Nontidal Wetlands)
       For three of the disposal pits/areas, excavation disturbs more than 5,000
       sguare feet of nontidal wetlands and is subject to permitting standards, which
       may include the creation, restoration,  or enhancement of wetlands (applicable).

!   Chesapeake Bay Critical Areas Criteria
   - Maryland Natural Resources Code (§8-8101 to 8-1816)
     Because all disposal pits/areas are within the 1,000-ft buffer of the Chesapeake
     Bay known as the "Critical Area," excavation activities are subject to natural
     resource protection standards and restrictions,  which reguire the
     implementation of storm water runoff control devices (applicable).

2.11.2.3  Action-Specific ARARs.

!   Maryland Waste Management Program
   - COMAR 26.13.02 (Identification and Listing of Hazardous Waste)
       Excavated soil and waste may be hazardous and reguire sampling and analysis
       for identification (applicable).
   - COMAR 26.13.03 (Standards Applicable to Generators of Hazardous Waste)
       Waste excavated on-site is analyzed to determine if it is hazardous. Hazardous
       waste is identified either by testing or knowledge of the waste based on the
       material or processes used to produce it. If the excavated waste is determined
       to be hazardous,  USEPA identification numbers are obtained before its
       treatment, storage, disposal, or transportation. Manifests are prepared for
       hazardous on-site materials transported to off-site treatment, storage, and
       disposal facilities.  On-site hazardous waste is packaged, labeled, and marked
       according to U.S.  Department of Transportation regulations  (49 CFR 172, 17,
       178, and 179) (applicable).
   - COMAR 26.13.04 (Standards Applicable to Transporters of Hazardous Waste)
       A manifest accompanies each off-site shipment of hazardous waste.
   - COMAR 26.13.05 (Standards for Owners and Operators of Hazardous Waste
     Treatment,  Storage,  and Disposal Facilities)
       As part of the excavation alternative,  no hazardous waste is treated on-site;
       however,  it is temporarily stored on-site. All excavated material determined
       to be hazardous is temporarily stored in containers that meet standards set
       forth in these regulations before disposal.  Any off-site hazardous waste
       landfill used to dispose of hazardous waste must comply with these regulations
       (relevant and appropriate).
   -  COMAR 26.13.05.07 (Closure and Post-Closure)
       Reguirements for clean closure of waste piles  are relevant for excavation of
       the disposal pits/areas (relevant and appropriate).
   - COMAR 26.13.05.09 and 26.13.05.10  (Standards Applicable to Tanks and Containers)
       All excavated material determined to be hazardous is temporarily stored in
       containers that meet these standards before disposal (applicable).
   - COMAR 26.13.05.14 (Landfills)
       Any off-site hazardous waste landfill used to dispose of hazardous waste must
       comply with these standards  (applicable).

!  RCRA - Federal Waste Management Program  [42 USC 6921 Identification and
  Listing of Hazardous Waste]
  - 40 CFR Part 261 (Waste Identification)
    Waste generated or excavated on-site may gualify as a newly listed waste not
    yet incorporated into Maryland Hazardous Waste Regulations  (applicable).
  - 40 CFR Part 264, Subpart S  (Corrective Action for Solid Waste Management

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    Units)  [42 USC  6924  Standards Applicable  to  Owners  and  Operators  of
    Hazardous Waste Treatment,  Storage,  and Disposal  Facilities]
     On-site temporary storage  of waste  in piles is conducted in  accordance  with
     this  regulation (relevant  and  appropriate).
  -  40  CFR Part  268 [Land  Disposal  Restrictions  (LDR)][42 USC 6924  Standards
    Applicable to Owners and  Operators of Hazardous Waste Treatment,  Storage,
    and Disposal Facilities]
     All  hazardous waste  generated or excavated on-site is treated according  to
     LDR  levels for constituents in the waste.  LDR forms accompany each
     manifested shipment  of  waste  (applicable).

!   Maryland Water  Pollution Control Regulations
  -  COMAR  26.08.02.03 (Surface  Water Quality  Criteria)
     The  excavation alternative incorporates methods to contain  or control  all
     excavated  material so as  to prevent contact with  surface water. Any  collected
     or contained  water is discharged in accordance  with this regulation  (relevant
     and  appropriate).

!   Federal Water Pollution Control  Act   [33  USC  1311  Effluent Limitations]
   - 40 CFR Part 131 (Water Quality Standards)
     This  standard  is applicable for potential  contaminants that  may  enter surface
     water and are  not addressed under state  standards. The excavation alternative
     incorporates methods  to  contain or  control  all excavated material in  a  way that
     prevents contact with surface  water. Any collected or  contained  water is
     discharged  in  accordance with  this  regulation  (applicable).

!   U.S. Army Corps  of Engineers [33 USC  1341  Certification]
   - 33 CFR Part 323 (Permits for Discharges  of  Dredge  of Fill Material into the
     Water of the United States)
        Because  9 of the 13 disposal pits/areas  are located in wetlands, excavation
       activities must follow reguirements for wetlands protection  or implement
       engineering  controls to  minimize  or prevent adverse  impacts  (applicable).
   - 33 CFR Part 322 (Construction  in Waterways)
       The construction  of a  pier at Carroll  Island reguires  a water  guality
       certification (applicable).

!   Federal Clean Air Act  [42  USC  7521 Establishment  of  Standards]
   - 40 CFR Part 50 (National Primary and Secondary Ambient Air Quality Standards)
       Earth moving operations  may  emit  pollutants that affect ambient air guality
       standards for criteria pollutants (applicable).
   - 40 CFR Part 61 (National Emission Standards for  Hazardous Air  Pollutants)
       Because excavation  activities may emit hazardous air pollutants, emission
       control eguipment and  compliance  with  specific standards may be reguired,
       depending on the  activity and the type of pollutant  (applicable).

!   Maryland Air  Quality  Standards
   - COMAR 26.11.06.03D  (Particular Mater From Materials Handling and
     Construction)
       Construction activities  that generate  particular emissions (e.g., dust),
       including excavation and vehicular traffic, reguire  reasonable precautions
       (e.g., wetting of dust)  to prevent particular  matter from  becoming  airborne
       (applicable).
   - COMAR 26.11.06.06B  (Control of VOCs From Installations)
       The excavation of soil potentially contaminated with solvents  or other VOCs
       may result in VOC emissions  in excess  of  20 pounds per day,  which is
       prohibited by this  regulation unless the  total emissions are reduced  by 85%
       through the  use of  control devices  (applicable).
   - COMAR 26.11.06.08  (Nuisance)
       Excavation is performed  in a manner that  does  not create a nuisance or air
       pollution (applicable).
   - COMAR 26.11.09 (Control  of Fuel-Burning  Eguipment  and  Stationary Internal
     Combustion  Engines)
       Fuel-Burning eguipment (including excavation eguipment) and  stationary
       combustion engines  (including electrical  generators  and waste-screening
       eguipment) are maintained to comply with  visible emission, particular matter,
       and other emission  standards (applicable).

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! Maryland Erosion and Sediment Control Regulations
- COMAR 26.17.01 (Erosion and Sediment Control)
Standard engineering practices are applied to reduce or prevent erosion or
sediment building during excavation. These practices may include the
installation of sediment traps or a silt fence (applicable).

2.11.3 Cost Effectiveness

Of the three excavation alternatives, Alternative 2 (hand excavation and disposal/treatment of excavated
material) is the most cost-effective. It provides maximum long-term protection of human health and the
environment with the least expenditure of funds.

2.11.4 Use of Permanent Solutions and Alternative Treatment Technologies or
Resource Recovery Technologies to the Maximum Extent Practicable

The selected remedy, Alternative 2 (hand excavation and disposal or treatment or excavated material), is a
permanent solution and uses treatment to the maximum extent practicable. It provides the best balance of
tradeoffs among the alternatives. Alternatives 2, 3 (conventional excavation), and 4 (telerobotic excavation)
meet the threshold criteria and are comparable in terms of degree of long-term effectiveness and reduction in
toxicity, mobility, and volume of waste. Alternative 1 (no action) does
not meet the threshold criteria of overall protection and compliance with ARARs.

Alternatives 2, 3, and 4 differ primary in terms of short-term effectiveness, implementability, and cost.
Alternative 2 provides more short-term effectiveness than Alternatives 3 and 4, which include using the
armored filtered air shelter. Alternatives 3 and 4 may be more difficult to implement because of their
innovative technologies and higher costs.

2.11.5 Preference for Treatment as a Principal Element

By excavating waste at Operable Unit A; segregating the waste into rubble, soil, and debris fractions; and
treating the fractions to destroy contaminants, as appropriate, the proposed remedy addresses the principal
environmental threat through treatment to the maximum extent practicable. Therefore, the statutory
preference for a remedy that incorporates treatment as a principal element is satisfied.

2.12 DOCUMENTATION OF SIGNIFICANT CHANGES

The Proposed Plan present the selected remedy as the preferred alternative. No significant changes have
been made.

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                               3. RESPONSIVENESS SUMMARY


   The final component of the Record of Decision is the Responsiveness Summary.  The purpose of the
Responsiveness Summary is to provide a summary of the public's comments,  concerns,  and questions about the
disposal pits/areas at Carroll Island and the Army's responses to these concerns.

   During the public comment period, written comments,  concerns and questions were received by APG, EPA and
MDE.

   APG held a public meetinq on Auqust 21, 1996, to formally present the Proposed Plan and to answer
questions and receive comments.  The transcript of this meetinq is part of the administrative record for the
site.  All comments and concerns summarized below have been considered by the Army and EPA in selectinq the
final cleanup methods for the disposal areas at the Carroll Island.

   This responsiveness summary is divided into the followinq sections:

   3.1 Overview,
   3.2 Backqround on community involvement,
   3.3 Summary of comments received durinq public comment period and APG's responses,
   3.4 Sample newspaper notice announcinq public comment period and the public meetinq.


3.1   OVERVIEW

   At the time of the public comment period, the Army endorsed a preferred alternative for the cleanup of the
former disposal areas at the Carroll Island Study Area.  APG's preferred alternative for the disposal areas
was to hand excavate the material and dispose of it off-site.  EPA concurred with the preferred alternative.
Maryland Department of the Environment supported the Army's plan and stated it would finalize its position
after the public comment period.  MDE now concurs with the preferred alternative.

   The community aqrees with APG and EPA's preferred alternative of excavatinq the disposal pits. An
important factor for the community is that APG perform the work safely and have plans in place to protect the
community.

3.2   BACKGROUND ON COMMUNITY INVOLVEMENT

   Citizen's interest in the Carroll Island Study Area increased substantially in 1993.  Residents new to the
area were unaware of APG's history and current activities, includinq the cleanup proqram.  APG prepared fact
sheets, attended community meetinqs, hosted tours, and held one-on-one discussions with members of the
community to increase their knowledqe of APG's activities and address any concerns.

   Concerns raised prior to the Proposed Plan included interest in whether any substances had moved off-post
from APG throuqh qroundwater or surface water.  A number of citizens have private wells which were sampled
and were not impacted by any substances at Carroll Island.  APG has been keepinq the community informed about
the Remedial Investiqation of Carroll Island and the Focused Feasibility Study for the disposal pits throuqh
the monthly Restoration Advisory Board meetinqs, fact sheets, community meetinqs, personal discussions.

   APG's community relations activities for the Proposed Plan for the disposal pits at Carroll Island
included the followinq.

!  APG released the Proposed Plan for the Carroll Island disposal  areas for public comment on July 15,
   1996.   Copies were available to the public at APG's information repositories at the Aberdeen and
   Edqewood Branches of Harford County Library, Miller Library at Washinqton Colleqe, and the
   Baltimore County Department of Environmental Protectinq in Towson.

!  APG issued a press  release  to APG's full medial list announcinq the availability  of the Proposed Plan,
   the dates of the public comment period, and the date and time of the public meetinq.

!  A  45-day public comment period on the  Proposed Plan ran from July  15 to Auqust 28,  1996.  Upon
   a request from the citizens qroup, Aberdeen Provinq Ground Superfund Citizens Coalition, the
   comment period was extended an additional 15 days.

!  APG placed newspaper advertisements announcinq the public comment  period and meetinq  in The
   Aeqis, the Cecil Whiq,  The Avenue, the Kent County News, and the Bay News.

!  A  fact sheet was prepared and published  on  the Proposed Plan and copies were mailed to over 2,500

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   citizens and elected officials on its Installation Restoration Program mailing list. The fact sheet
   included a form which citizens could use to send APG their comments.

 !  The APG News featured a story on the proposed plan in the July 24 edition and ran reminder notices
   about the public meeting in later issues.

 !  A reminder notice about the public meeting was also included on the postcards announcing the
   August Restoration Advisory Board meeting and sent to the 2,500 citizens and elected officials on the
   mailing list.


 !  On August 21, 1996, an public meeting was held at the Oliver Beach Elementary School.
   Representatives of the Army,  EPA,  and MDE were available to answer guestion about the proposed
   alternatives under consideration.


3.3   SUMMARY OF COMMENTS RECEIVED DURING THE PUBLIC COMMENT PERIOD AND AGENCY RESPONSES

   Comments raised during the Carroll Island public comment period on the Focused Feasibility Study and the
Proposed Plan are summarized below.  The comments are categorized by topic and by source.

COMMENTS FROM QUESTIONNAIRE INCLUDED WITH FACT SHEET

   As part of its fact sheet on the Proposed Plan,  APG included a guestionnaire that residents could return
with their comments.  APG received 23 completed returns.

   Responses on the completed returns were

       0     Alternative 1:   Take  no  action
       19    Alternative 2:   Hand-excavation and Disposal/Treatment  of Excavated Material
       0     Alternative 3:  Excavation Using Construction Eguipment  is a Shelter and
                              Disposal/Treatment  of  Excavation Material
       1     Alternative 4:  Telerobotic Excavation in  a  Shelter and  Disposal/Treatment
                           Excavated Material
       1     Have  no preference
       2     No alternative  selected

Additional comments on the guestionnaires and APG's responses are listed below.

Comment 1:  Given cost and time to implement, Alternative 2 is most practicable.

   APG Response:  APG agrees cost and time are factors  to be considered.  More importantly,
Alternative 2 also meets the first criteria of protecting human health and the environment.

Comment 2:  Sooner the better! Protect the workers but  move forward and get it done.  The sooner you
get this done,  the sooner you can start on other sites  at Edgewood.   Good Luck.

   APG Response:  APG agrees with the dual goals of moving forward as guickly as possible while keeping the
protection of human health and the environment as the top priority.   Many cleanup projects are progressing
simultaneously,  including several at sites in Edgewood.

Comment 3:  The proposed alternative appears to be the  most cost-effective method under current
technological capabilities.  Is any research currently being done on on-site decontamination of waste
materials through chemical or bacteriological means?  I know this approach would be a "long shot'
alternative but it might be less destructive to the current environment and reguire less transfer of waste
materials from one site to another site.

    APG Response:   APG agrees with the desire to take advantage of current technological developments.  In
addition, environmental laws promote the use of in-place treatment so materials are not simply transferred
from one location to another.  On-site treatment is usually conducted for a continuous waste stream that
reguires treatment over time, such as contaminated groundwater.   However, because it is not known what type
of waste will be encountered at the site when the excavation begins,  it would be difficult and cost
prohibitive to try and treat the waste on-site.

Comment 4:  Is  it possible to comment and receive updates via Internet E-Mail? Does APG-IRP have a Web site
that would allow information exchange?

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   APG Response:  The Installation Restoration Program is in the process of setting up a Web page and an
E-Mail address to give the public the ability to communicate with us by computer.  We will keep the community
informed and let you know when the Web Site and E-Mail address are available for use.

Comment 5:  Move deliberately and guickly to cleanup the site.

   APG Response:  APG appreciates the desire for cleanup to proceed as guickly as possible.  By identifying
the disposal sites as an area where action could be taken while the comprehensive overall
studies continue, APG is able to expedite their cleanup.

Comment 6:  Area should be maintained as a wildlife refuge.  Cleanup must be thorough and complete, ending
any possible contamination of groundwater, surface water or soil.

   APG Response:  APG appreciates the input on the long-term plan for the site.  The current Proposed Plan
addresses only the disposal areas.  Once APG completes its full studies, it will formally seek input from the
public on any remaining issues,  such as the long-term use of the site.

Comment 7:  A resident commented they had no preference at this time but would like more information.
Their guestions were the following.

a) What will be done with hazardous materials after they are found and how will it then be disposed of?


   APG Response:  The waste will be segregated and sampled to determine if it is hazardous.  All waste will
then be disposed of in accordance with Federal and state reguirements.  These reguirements dictate how the
material is sampled, handled, transported, treated, and disposed.


b) How has this situation already affected the environment as well as the public?

   APG Response:  Since the contents of the pits have not migrated and contaminated the groundwater or
surface water, there have been minimal impacts to the environment and no impacts to the public.

c) There is a high percentage of cancer in the State of Maryland—does this have anything to do with this
situation?

   APG Response:  The contamination that exists at Carroll Island has not migrated away from the Island and
has not impacted any surrounding areas.


d) If there is an accident with contamination what are the effects—health, environment, etc.?

   APG Response:  If an accident were to occur, the affects to workers could be varied depending on the type
of chemical accident.  However,  APG will be taking the highest degree of precaution.  Workers and the
surrounding communities will be protected against any accident.

Comment 8:  Take material out of area so no chance of area contamination.

   APG Response:  APG agrees the disposal sites should be excavated and the waste material properly disposed
of in accordance with federal, state and local laws.


Comment 9:  APG received two comments related to its boating restrictions.  One resident asked if the
restriction of Maxwell Point was because of surface water contamination or munitions.  A second resident
expressed concern about the lack of places to anchor on the Gunpowder and encouraged the Army to cleanup the
area and allow boaters access or at least the ability to anchor near the shore.

   APG Response:   Maxwell Point is a restricted area under APG's boating regulations because of the
possibility old munitions may be present.  For public safety reasons, APG has increased its enforcement of
boating restrictions and its efforts to provide information to the public on the restrictions. APG is
sensitive to the desire of the public to have unrestricted use of the waterways and is conducting further
research and study of the issue.

COMMENTS FROM AUGUST 21, 1996 PUBLIC MEETING

   APG received the following written comments from Mr. James Gaibrois at the public meeting on August 21,
1996.

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Comment 10: The map on page 2 of the fact sheet shows the National Guard on the wrong side of Eastern
Avenue.

APG Response: APG apologizes for this error and will correct it in future maps.

Comment 11: In Alternative 1, the showing of "no cost" does not account for monetary liabilities,
decrease of property values, recurring security and patrols, etc. which would exist even if nothing is done.
These costs would be continued annually if no action was taken but would decrease if mitigating action would
be taken.

APG Response: Although APG is concerned about property values, the EP mandates that only long-term
monitoring can be considered for the no-action alternative and its associated costs.

Comment 12: In Alternative 3 and 4, the costs may not include the salvage value or the remaining resale
value of the newly developed eguipment or the heavy hardware to be used. If design rights to the design
of this eguipment become government property, then the final net cost may be less than stated.

APG Response: Although there may be resale value or eguipment that could be reused this is not
usually considered in this type of cost estimate. The cost estimates are conducted for comparing one
alternative against another. Resale or reuse of eguipment is usually not known at this time and not
considered in the cost estimate. However, eguipment is reused where possible.

Comment 13: Since alternative 2 has a much shorter period for accomplishment, its "short-term effect"
should be rated higher than the other alternatives and should be shown as meeting the criterion.

APG Response: Alternative 2 is rated higher than the other alternatives for "short-term
effectiveness." This is reflected in this ROD.

WRITTEN COMMENTS FROM BALTIMORE COUNTY RESIDENT

Comment 14: APG received the following written comments and guestions from a nearby resident, a) The July
1996 fact sheet summarized field work at the Carroll Island site and listed the number of groundwater,
surface water, sediment and soil samples taken. However, the fact sheet did not present the actual results
of those samples. I would like to review the results of those samples and the locations of where those
samples were taken. The fact sheet also stated that analysis showed that past activities have had minimal
impact. Please define minimal impact.

APG Response: APG makes available for public review all documents and reports which are part of its
decision making process of the cleanup program. The documents are available for public review at the four
information repositories listed in section 3.2. The Baltimore County repository is at the Baltimore County
Department of Environmental Protection, 401 Bosley Avenue, Room 416, Towson, MD, 21204, (410) 887-2762.

The results of the sampling conducted at Carroll Island are contained in the First, Second, and Third
Quarter Technical Memorandums for Carroll Island. A risk assessment is being conducted based on the
data gathered in the Remedial Investigation for human health and the environment. There were no risks
or impacts to human health from the disposal pits or any other sites at Carroll Island. There were risks to
earthworms from some metals found in the sediment. However, at this time, it has not been determined
whether the metals are naturally occurring or related to activities that occurred at Carroll Island.

b) Alternative 2 appears to be the best cleanup alternative listed in the fact sheet. Are these the only
alternatives?

APG Response: Other technologies were considered in the focused feasibility study which was conducted to
determined how to cleanup the site. Other technologies were screened out before they were formulated as
alternatives based on implementability, feasibility and cost. Three excavation alternatives were chosen as
possible remediation alternatives and presented to the public.

c) I am concern about possible future impacts on the environment. Is there a contingency plan for future
chemical substance contamination caused by shoreline erosion and flooding?

APG Response: Yes, a feasibility study is being conducted to address the remainder of the Island.
Shoreline erosion and flooding is a problem a Carroll Island and this study will determine how to reduce
or eliminate any negative impacts.

d) What about unexploded ordnance. I want to know what has already been planned or how long it will
take to plan something.

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APG Response: UXO support will be provided by trained specialists. UXO support is required prior to and
during excavation to facilitate the location and removal of UXO if encountered. A UXO sweep is performed
every two feet to detect any buried UXO. If metallic objects are detected, they are unearthed by hand. If
the metallic object is UXO it is inspected to determine the type of munition and whether it is intact. If
the UXO is not safe for transport, or storage, it may be detonated on-site.

e) Where are the disposal facilities? What are the plans for eventual disposal?

APG Response: The material has not been classified as hazardous yet. When the disposal pits are
excavated the waste will be inspected and sampled to determined if it is hazardous. The 5% to 30% hazardous
waste was based on knowledge gained from the excavation of disposal pits at other sites. This
was also an assumption that was made for comparable cost estimating purposes. There may actually be more or
less hazardous waste present in the pits.

g) Do you have an emergency preparedness program in place? If there is some type of plan, I am not aware of
it. When will this information be disseminated to the community?

APG Response: Both APG and the counties surrounding it have comprehensive emergency plans in place to
cover any type of hazard-from weather emergencies to a chemical incident at APG or on the highway or
railroad. The Baltimore County Office of Emergency Preparedness in Towson is responsible for the plan which
covers the off-post community near Carroll Island. The phone number for this office is 887-5996. County
plans are coordinated with the Maryland Emergency Management Agency and the Federal Emergency Management
Agency.

Before APG begins field work or a remedial action, it prepares all necessary health and safely plans.
These plans ensure the protection of workers and the surrounding community. Preparing these plans are part
of the next step in the cleanup process. APG will work with Baltimore County and interested citizens in
developing appropriate plans for this project and in communicating the plans to the public.

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                      4.  REFERENCES
Aberdeen Proving Ground  (APG), 1996.  Proposed Plan for Operable Unit A, Carroll
       Island, Aberdeen Proving Ground,  Maryland, July 1996.

APG, 1995.  Focused Feasibility Study, Operable Unit A, Carroll Island, Aberdeen
       Proving Ground, Maryland,  December 1995.

APG, 1994.  The Remediation of Carroll Island Lower Island Disposal Site, Aberdeen
Assessment Report, Edgewood Area, Aberdeen Proving Ground, Maryland, Report No.
39-26-0490-90.

U.S. Army Toxic and Hazardous Materials Agency  (USATHAMA.), 1983.
       Environmental Survey of the Edgewood Area of Aberdeen Proving Ground,
       Maryland, Report No. DRXTH-AS-FR-82185.

U.S. Environmental Protection Agency  (USEPA) , 1985.  "Amendment to National Oil
       and Hazardous Substances Contingency Plan; the National Priorities List, "Federal
       Register, Proposed Rule, 40 CFR Part 300, Vol.  50, No. 69,  April 10, 1985.

USGS, 1991.  Hydrogeologic Data Report for Carroll Island, Aberdeen Proving
       Ground, Maryland, Open File Report 89-388, 1991.

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