EPA/ROD/R03-98/070
                                   1998
EPA Superfund
     Record of Decision:
     NAVAL SURFACE WARFARE CENTER - DAHLGREN
     EPA ID: VA7170024684
     OU05
     DAHLGREN, VA
     09/30/1998

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EPA 541-R98-070


                         SITE 17 1400 AREA LANDFILL

                         NAVAL SURFACE WARFARE CENTER
                                DAHLGREN SITE
                              DAHLGREN, VIRGINIA
                              RECORD OF DECISION
                                September 1998

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                            TABLE OF CONTENTS

SECTION                                                                                     PAGE

1.0    THE DECLARATION	1-1
       1.1    SITE NAME AND LOCATION	1-1
       1.2    STATEMEENT OF BASIS AND PURPOSE	1-1
       1. 3    DESCRIPTION OF THE SELECTED REMEDY	1-1
       1. 4    STATUTORY DETERMINATIONS	1-2

2.0    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  History of Site Activities	2-1
       2.2.2  Previous Investigations	2-6
       2.2.3  Enforcement Actions	2-6
       2.2.4  Highlights Of Community Participation	2-6
       2.3    SCOPE AND ROLE OF RESPONSE ACTION AT SITE 17	2-6
       2 . 4    SUMMARY OF SITE CHARACTERISTICS	2-7
       2.4.1  Sources of Contamination	2-7
       2.4.2  Description of Contamination	2-7
       2.4.3  Contaiminant Migration	2-10
       2 . 5    SUMMARY OF SITE RISKS	2-12
       2.5.1  Human Health Risks	2-12
       2.5.2  Environmental Evaluation	2-14
       2.5.3  Development of Preliminary Remediation Goals	2-15
       2.6    DESCRIPTION OF ALTERNATIVES	2-16
       2 . 7    SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES	2-20
       2.7.1  Threshold Criteria	2-20
       2.7.2  Primary Balancing Criteria	2-20
       2.7.3  Modifying Criteria	2-22
       2 . 8    THE SELECTED REMEDY	2-22
       2.8.1  Performance Standards	2-25
       2 . 9    STATUTORY DETERMINATIONS	2-27
       2.9.1  Protection of Human Health and thevironment	2-27
       2.9.2  Compliance with ARARs	2-27
       2.9.3  Cost-Effectiveness	2-28
       2.9.4  Utilization of Permanent Solutions and Alternative Treatment Technologies
              or Resource Recovery Technologies to the Maximum Extent
              Practical	2-28
       2.9.5  Preference for Treatment as a Principal Element	2-28
       2.9.6  Documentation of Significant Changes	2-28

3 . 0    RESPONSIVENESS SUMMARY	3-1
       3 .1    BACKGROUND ON COMMUNITY INVOLVEMENT	3-1
APPENDICES

       A      VIRGINIA CONCURRENCE LETTER
       B      SUMMARY OF INFORMAL COMMENTS
       C      APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS

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                                LIST OF TABLES
NUMBER
                                                                                    PAGE
2-1       Maximum Detected Concentrations for COCs Requiring Remediation 	2-9
2-2       Human Health Chemicals of Concern and Exposure Point Concentrations 	2-13

                               LIST OF FIGURES


NUMBER                                                                              PAGE

2-1       Location Map 	2-2

2-2       Site Location Map 	2-3

2-3       Site Map 	2-4

2-4       Total Magnetic Field Contour Map Site 17 	2-5

2-5       Sample Location Map 	2-8

2-6       Potentiometric Surface Map 	2-11

2-7       Site 17 Conceptual Remediation Plan - Selected Alternative 	2-23

2-8       Selected Alternative Remedial Action 	2-24

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                             1.0 THE DECLARATION

1.1      SITE NAME AND LOCATION

Site 17 1400 Area Landfill
Naval Surface Warfare Center Dahlgren Site
Dahigren, Virginia

1.2      STATEMENT OF BASIS AND PURPOSE

This decision document presents the selected remedial acton for Site 17, 1400 Area Landfill at
the Naval Surface Warfare Center, Dahlgren Site  (NSWCDL),  Dahlgren, Virginia. This document
focuses on remedial decisions for Site 17 at the NSWCDL and the term "site" in this document
refers to Site 17. This determination has been made in accordance with the Comprehensive
Environmental Response, Compensation, and Liability Act of 1980 (CERCLA),  as amended by
Superfund Amendments and Reauthorization Act of 1986  (SARA),  and to the extent practicable, the
National Oil and Hazardous Substances Pollution Contingency Plan (NCP).  This decision is based
on the administrative record for this site.

The Commonwealth of Virginia concurs with the selected remedy  (see Appendix A).

ASSESSMENT OF THE SITE

Actual or threatened releases of hazardous substances from this site, if not addressed by
implementing the response action selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare, or the environment.

1.3       DESCRIPTION OF THE SELECTED REMEDY

The Navy will manage the remediation of the 1400 Area Landfill as a single remedial action. The
remedial action selected in this ROD addresses contamination associated with Site 17 1400 Area
Landfill contents, surface soils, surface water, sediment, and groundwater.

The selected remedy for Site 17 is to use phytoremediation to address both soils and
groundwater. Institutional controls, as well as groundwater,  surface water, and sediment
monitoring will also be a portion of the remedy.

The major componenis of the selected remedy are:

The landfill area will be capped, to address surface soil contamination, with a 2 -foot-thick
vegetative soil layer. Natural vegetation such as hybrid poplars and evergreens will be planted
on this layer to control erosion and reduce infiltration and subseguent groundwater discharge to
the tributaries via evapotranspiration. This vegetation will also provide a habitat enhancement.
The cap will achieve an eguivalent net reduction in infiltration and provide eguivalent erosion
protection per 9 Virginia Administrative Code (VAC) 20-80-250.  (infiltration calculations using
the Hydrological Evaluation of Landfill Performance (HELP) model were performed to determine
whether there can be a functional eguivalency between a Commonwealth of Virginia sanitary
landfill cap [Alternative 2]  and a soil cap coupled with phytoremediation  [Alternative 4].
According to these calculations, there is a similar reduction of infiltration through the
landfill using either the sanitary landfill cap or the soil cap with the phytoremediation
alternative.)

Groundwater discharging to surface water bodies at Site 17 will be primarily contained using

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natural vegetation such as hybrid poplars and evergreens.

Waste/fill within 100 feet of the tributaries shall be excavated to address Commonwealth of
Virginia regulation 9 VAC 20-80-250 which requires a 100 foot setback for waste adjacent to
surface water bodies. It is estimated that 17,600 cubic yards would have to be excavated and
consolidated beneath the cap.

The marsh area near monitoring well GW17-13 will be remediated to address residual mercury
contamination even though sediment criteria are not exceeded. Approximately 970 cubic yards of
marsh sediment would be transported to an offsite treatment and disposal facility.

Institutional controls will be implemented to limit future site land use. For Site 17, an
institutional control plan will be developed as part of the remedial action design and include:
access controls, signs along the perimeter of the site, restrictions on shallow groundwater use
for drinking water, description of land use controls in the base master plan, periodic
inspection, monitoring, and re-evaluation of land use controls, annual certification that
institutional controls are in place, notification to the U.S. EPA and state regulators
whenever the Navy anticipates any major changes in land use restrictions, public notice, and a
deed notification.

The Navy shall institute the following institutional controls within 90 days of completion of
the installation of the phytoremediation system: a real property description notation, Base
Master Plan notations, and limited site access. The Base Master Plan shall note the area as one
in which residential development cannot occur, shallow groundwater cannot be used, and site
access shall be limited. A notation shall be filed in the real property file maintained at
Engineering Field Activity, Chesapeake (EFA Ches) (US Navy) for this site indicating the extent
of the area and the fact that solid wastes are present. The institutional controls shall also
include the following: within 90 days after completion of the remedy, the Navy shall produce a
survey plat prepared by a professional land surveyor registered by the Commonwealth of Virginia
indicating the location and dimensions of the disposal area and the extent of groundwater
contamination. Monitoring well locations shall be included and identified on the survey plat.
The plat shall contain a note, prominently displayed, which states the owner's future obligation
to restrict disturbance (excavation or construction) of the property; post-closure use of the
property shall prohibit residential use,  access or use of groundwater underlying the property
for any purpose except monitoring, and the function of the monitoring systems shall not be
disturbed. When landfill closure is complete, the owner of the property shall submit the survey
plat to the local recording authority, and shall record a notation with the deed  (or some other
instrument which is normally examined during title search at the local land recording authority)
notifying any potential purchaser of the property that the land has been used to manage solid
waste and the integrity of the cover system or the function of the monitoring system may not be
disturbed.

The Navy shall institute groundwater monitoring to ensure that remedial action objectives (RAOs)
are being maintained. The frequency of analysis and the length of time for monitoring shall be
developed in the Operation and Maintenance Plan.

The Navy shall monitor the surface waters and sediments in the tributaries adjacent to Site 17
to ensure RAOs are being maintained. The frequency of analysis and the length of time for
monitoring shall be developed in the Operation and Maintenance Plan.

Implementation of the selected remedy is expected to fully address the principal threats at the
site by reducing the potential risk to human health and the environment associated with the
soils and groundwater.

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1.4      STATUTORY DETERMINATIONS

The selected remedy for Site 17 is protective of human health and the environment complies with
federal and state requirements that are legally applicable or relevant and appropriate to this
action, and is cost-effective.

The remedy addresses the remediation of surface soil and groundwater contamination at Site 17.
The selected remedy will provide for the long-term containment of contamination in surface soils
and groundwater beneath the site. The installation of a phytoremediation system will reduce
direct contact and ingestion threats and reduce risks to ecological receptors from contaminated
surface soils and groundwater by containing contaminants within these media.

The selected remedy for Site 17 will be implemented to meet all applicable or relevant and
appropriate requirements (ARARs) whether chemical-, action-, or location-specific. No waivers of
any ARARs are requested. Phytoremediation is a permanent solution and is an appropriate remedy
for the contamination in soils and groundwater. Phytoremediation is an innovative technology
whose application at Site 17 is considered technically superior to other alternatives.

This remedy utilizes permanent solutions and alternative treatment (or resource recovery)
technologies to the maximum extent practicable for this operable unit. However, because
treatment of the principal threats of the site was not found to be practicable, this remedy does
not satisfy the statutory preference for treatment as a principal element.

Because this remedy will result in hazardous substances remaining on-site above health-based
levels, a review will be conducted within five years after commencement of the remedial action
to ensure that the remedy provides adequate protection of human health and the environment.


                                         2.0 DECISION SUMMARY

2.1       SITE NAME, LOCATION, AND DESCRIPTION

This ROD is issued to describe the Department of the Navy's  (Navy) selected remedial actions for
Site 17, 1400 Area Landfill, at the Naval Surface Warfare Center, Dahlgren Site (NSWCDL),
Dahlgren, Virginia  (Figure 2-1). Site 17 is one of several Installation Restoration  (IR)  sites
(Figure 2-2) located at the NSWCDL facility. The 1400 Area Landfill is an inactive landfill
located in the northeast corner of the NSWCDL, north of Frontage Road and south of U.S. Highway
301 (Figure 2-3).  The general site configuration, based on a geophysical survey, is shown in
Figure 2-4. Two unnamed drainage tributaries form the western and eastern boundaries of the
site.  A small pond is located in the western portion of the site with a marsh on the eastern
portion. Building 1400 is located between the landfill and Frontage Road and is encompassed by a
chain link fence.  The site was used as a landfill, where municipal solid waste and construction
debris were deposited, compacted, and covered on a periodic basis during the early 1970s and
possibly until 1978. During the 1993 Phase 1 geophysical survey of the landfill, exposed
metallic debris was visible along the eastern slope of the landfill where cover material
thinned.

Elevations at the site range from approximately 14 feet above mean sea level (msl) along the
drainage ditches to over 20 feet msl along the high ground between the streams. Slopes are
gentle and generally less than 5 percent. Surface drainage generally flows overland to the
tributaries that flow into Hideaway Pond approximately 600 feet south of Building 1400. The
landfill is fully vegetated with tall grass. Soil cover exists over the majority of the
landfill. The area bordering the site to the north and west is undeveloped and heavily wooded.

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Land within a 2-mile radius of the 1400 Area Landfill is mainly undeveloped. Buildings housing
various base operations are located about 200 feet east of the site, and more facilities are
being constructed in this general area. Southeast of the site, on the east side of Hideaway
Pond, is a former bombing range that is undeveloped.

2.2       SITE HISTORY AND ENFORCEMENT ACTIVITIES

2.2.1     History of Site Activities

Based on aerial photographic evidence, Site 17 was used for sand and gravel extraction beginning
as early as 1952. Prior to this,  the site was a plowed field. On 1943 aerial photographs, a
cleared, sguare area was visible directly south of U.S. Highway 301. In 1952, a shallow pit was
evident in aerial photographs west of the western tributary that bounders the site. Several
other clearings and a gravel pit were also evident on the site proper.  Sand and gravel removal
continued at the site until approximately 1969.

Landfilling operations at Site 17 began during the early 1970s, midway between the two
tributaries, and continued possibly until 1978. According to the Environmental Photographic
Interpretation Center (EPIC), red water (source unknown) was visible in the large bare areas
north of Building 1400.  By 1981,  the area between the tributaries had been filled and covered,
while other portions of the site were revegetating.





2.2.2     Previous Investigations

The first investigation at Site 17 was the Initial Assessment Study  (IAS) conducted in 1981. The
IAS included a record search, interviews,  and an on-site survey. The IAS concluded that Site 17
was used as a sanitary landfill and that no evidence of hazardous waste disposal had been
documented. As a result, Site 17 was not recommended for a Confirmation Study. However, Site 17
was included in the Confirmation Study because it was a suspected source of the mercury
contaminaton detected at Site 10 (Hideaway Pond).

The Confirmation Study was conducted in 1983 and 1984. As part of the Confirmation Study field
investigation at Site 17, five monitoring wells were installed. The wells were located to
characterize groundwater guality at one upgradient and four downgradient locations, based on
assumed groundwater flow directions. During well installation, soil samples were collected for
mercury analyses. Groundwater samples were collected in November 1984 and were analyzed for
mercury, total organic carbon (TOG), and total organic halides  (TOX). Groundwater samples were
later collected from four monitoring wells in 1991 by the NSWCDL. Sampling of stream sediment at
various depths upstream and downstream of the landfill was also conducted during the
Confirmation Study. The sediment samples were analyzed only for mercury.

Mercury was detected at 3.1 Ig/L in one of the groundwater samples collected within the site.
Mercury was not detected in any of the soil samples collected from well borings. TOX
concentrations ranged from undetectable levels to 220 Ig/L. Concentrations were not
significantly lower in the upgradient well. Mercury was not detected in sediment samples
collected upstream of the landfill, while mercury was detected in sediment collected from
downstream locations in both adjacent tributaries. Mercury was not detected in any of the three
surface water samples.

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2.2.3     Enforcement Actions

No enforcement actions have been taken at Site 17. The Navy has owned this property since the
early 1900's and is identified as the responsible party.

2.2.4     Highlights of Community Participation

In accordance with Section 113 and 117 of CERCLA, the Navy held a public comment period from
August 18, 1998 through September 16, 1998 for the proposed remedial acton described in the
Feasibility Study and in the Proposed Plan for Site 17.

These documents were available to the public in the Administrative Record and information
repositories maintained at the Smoot Memorial Library, King George, Virginia; the NSWCDL General
Library, Dahlgren, Virginia; and the NSWCDL Public Record Room, Dahlgren, Virginia. Public
notice was provided in The Freelance Star newspaper on August 18, 1998 and The Journal on August
19, 1998. A Public Meeting was held in the King George Courthouse on August 27, 1998. No written
comments were received during the comment period. A summary of comments and responses given at
the Public Meeting and a transcript of the Public Meeting are presented in Appendix B.

2.3       SCOPE AND ROLE OF RESPONSE ACTION AT SITE 17

Past disposal operations at Site 17 have resulted in contaminated soil and groundwater. The
proposed remedial actions identified in this ROD address contamination associated with Site 17,
1400 Area Landfill, as identified in the Draft Final Remedial Investigations  (RI)  Report, the
Addendum RI Report, and the Feasibility Study (FS) Report for Site 17. Several alternatives for
response actions for contaminated media are identified in Section 2.6. The rationale for
selecting one of those alternatives as the remedy for this site is described in Section 2.7. The
selected remedial action is discussed in Section 2.8.
The selected remedial action is to cover contaminated soils with a 2-foot-thick soil cap to
prevent semivolatile organic compounds  (SVOCs),  polychlorinated biphenyls  (PCBs),  chromium, and
thallium from contacting plants and animals  (ecological receptors).  Phytoremediation will be
utilized to address mercury contamination in groundwater. Phytoremediation is the use of shallow
and deep-rooted plants to remove, contain, or otherwise, render harmless, environmental
contaminants. The plants can chemically hold or remove metals from the soil and groundwater.
Waste/fill within 100 feet of the tributaries shall be excavated, dewatered, and consolidated in
the landfill beneath the soil cap. Marsh area sediments shall be excavated, dewatered, and sent
to an off site landfill for disposal.

This remedy is consistent with long-term remedial goals for Site 17. The remedial action will
help to reduce the principal threats to ecological receptors.

2.4       SUMMARY OF SITE CHARACTERISTICS

The RI at Site 17 was completed in phases. Geophysical investigations were initiated in 1993.
Sampling activities, consisting of soil sampling, surface water and sediment sampling, and the
installation and sampling of groundwater monitoring wells, were completed in 1994. Additional RI
sampling, consisting of additional surface and subsurface soil sampling and groundwater
monitoring activities, was completed in 1996. The results of the RI are summarized below.

2.4.1     Sources of Contamination

Geophysical and hydrogeologic investigations at Site 17 were conducted to identify disturbed

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areas and buried metallic objects, and to determine the extent of the landfill. The results of
the geophysical survey indicated the presence of metallic objects and other geophysical
anomalies in the landfill. Based on groundwater sampling results, the source of groundwater
contamination is the waste in the landfill.

2.4.2     Description of Contamination

Soil, groundwater, surface water, and sediment samples were collected and analyzed to determine
the nature and extent of contamination at Site 17  (Figure 2-5). The major contamination concerns
at Site 17 are associated with the landfill. Surface soil, groundwater, sediment and sunlace
water have been impacted by the waste disposal activities that occurred there. Table 2-1
presents the contaminants of concern (COCs) for each medium and the maximum concentration
detected for each COG. The results of the sampling and analyses are presented below.

Surface and Subsurface Soils

Low-level polynuclear aromatic hydrocarbon  (PAH)  contamination (0.020 to 4.6 mg/kg) and volatile
organic compounds (VOCs)   (0.270 to 6.8 mg/kg) were identified in surface soils. These compounds,
however, were not present in the subsurface soils and do not appear to be migrating downward.
Aroclor 1260 was also detected in surface soils but was not detected in any subsurface soil
sample from Site 17. In general, concentrations of inorganic constituents in surface soils
detected at Site 17 fall within the range of background concentrations for surface soils of the
Maryland coastal plain. In the subsurface soils,  the majority of inorganic constituents detected
were within the range of background subsurface soil values for the NSWCDL.

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                                TABLE 2-1

           MAXIMUM DETECTED CONCENTRATIONS FOR COCs REQUIRING REMEDIATION
                        SITE 17: 1400 AREA LANDFILL
                         NSWCDL, DAHLGREN, VIRGINIA

                                                   Maximum  Detected
           Analyte                                  Concentrations
                                SURFACE SOILS

SEMIVOLATILES  (mg/kg)
Benzo(a)anthracene                                          2.2
Chrysene                                                    2.5
Benzo(b)fluoranthene                                        2.0
Benzo(k)fluoranthene                                        2.1
2,6-Dinitrotoluene                                        0.074
PESTICIDES/PCBs  (mg/kg)
Aroclor-1260                                                2.2
METALS  (mg/kg)
Aluminum                                                  8,140
Arsenic                                                     6.3
Chromium                                                     39
Iron                                                      12,400
Thallium                                                    2.7
Vanadium                                                    18.6
                             SUBSURFACE SOILS
METALS(mg/kg)
Arsenic                                                     6.7
                               GROUNDWATER 1
METALS  (Ig/L)
Mercury                                                     0.26
                                SEDIMENT
VOLATILES  (mg/kg)
Acetone                                                      0.2
MISCELLANEOUS  (mg/kg)
Phenols                                                      729
TCL PESTICIDES/PCBs  (mg/kg)
Arochlor-1260                                                0.58
METALS  (mg/kg)
Aluminum                                                    13,500
Cobalt                                                       73.3
Mercury, Low Level                                          0.65598
Cyanide                                                      1.1
                               SURFACE WATER
METALS  (Ig/L)
Mercury, low level                                          0.02165

1   Groundwater COCs were developed based on the expected industrial use
    scenario

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Groundwater

A potentiometric surface map (Figure 2-6) was prepared based on 1996 water level measurements.
Low levels of volatile organic constituents were detected in only two out of nine groundwater
samples from Site 17. A wide range of semivolatile compounds, including primarily PAH and
phthalate compounds, were detected at Site 17. However, the distribution was random, and the
concentrations were generally very low. No primary maximum contaminant levels (MCLs) were
exceeded in the groundwater directly beneath the landfill. Lead was detected at a maximum
concentration of 42.3 Ig/L, which is above the associated action level of 15 Ig/L. Mercury
analysis of groundwater samples from Site 17 produced detectable concentrations in 6 of the 10
wells sampled. The highest concentration of mercury in 1996 was 0.26 Ig/L, detected in
monitoring well MW 17-15, near the center of the landfill and was an order of magnitude higher
than the results from any other well. The remaining wells with detectable concentrations of
mercury are distributed throughout the landfill area. No hot spots or mercury plumes were
identified in the landfill. Three groundwater samples were also collected from seepage in three
test pits and analyzed for mercury only. The highest concentration of mercury in these samples
was 0.12 Ig/L, below 0.14 Ig/L, the identified PRG for mercury.

Site 17 is located between two tributaries, to which the local groundwater discharges. The
shallow groundwater beneath Site 17 is not currently or reasonably expected in the future to be
a source of drinking water. When institutional controls are implemented, groundwater will be
restricted from such use. No primary maximum contaminant level (MCL) exceedences were detected
in the groundwater beneath Site 17.

Surface Water and Sediment

No significant VOC, SVOC, or pesticide/PCB contamination was identified in surface water samples
collected from Site 17. A review of surface water mercury results shows that mercury was
detected at low levels in all samples collected. The highest mercury concentration detected in
surface water was 0.02165 Ig/L. In general the eastern tributary had the higher concentrations
of mercury.

No significant VOC, SVOC, or pesticide contamination was detected in sediments.  Arochlor-1260
was detected in only one sample above the remedial goal at an estimated concentration of 0.58
Ig/kg. Three inorganic COCs (aluminum, cobalt and cyanide) were detected in sediments. Although
not a COG, the highest mercury concentration in sediment was 0.65598 mg/kg. No other detected
mercury concentration in the sediment samples was of this magnitude.

2.4.3     Contaminant Migration

Of the COCs identified in the FS, mercury is the most toxic and mobile. Mercury exists in both
organic and inorganic forms and may occur as elemental mercury or ionic mercury. Elemental
mercury is very dense and has a vapor pressure that increases rapidly with small increases in
temperature. There is a strong tendency for mercury in all its forms to sorb to nearly every
available surface, including sediments and soil organic matter. This behavior makes mercury
immobile under most environmental conditions. However, mercury is known to associate with
suspended solids and colloidal matter in aguatic systems, thus making it capable of mobility.

Mercury in its elemental state is very insoluble in water. In some of its ionic forms, however,
it is very soluble in water. Bacterial and abiotic chemical processes can methylate mercury ions
in both water and geologic materials. Many animals and certain plants can readily acguire methyl
mercury. Methyl mercury is easily absorbed by fish and other aguatic fauna, either directly
through the gills or by ingestion of contaminated aguatic plants and animals.

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In soils and surface waters, some forms of mercury partition to particulates, and in soils and
sediments,  sorption is one of the most important controlling pathways for transporting mercury.
Mercury is strongly sorbed to humic material, and trenching activities during Phase 2
investigations revealed that the top 3 feet of soil material at the landfill is humus. Inorganic
mercury sorbed on to soils is not readily desorbed; therefore surface runoff and colloidal
transport through aguifer materials are important transport mechanisms for inorganic mercury.

Methyl mercury guickly enters the aguatic food chain and thereby begins the process of
bioaccumulation and biomagnification in fish and other ecological receptors. The two tributaries
that are suspected of receiving groundwater discharge are located at the western and eastern
sides of the landfill, and both flow south into Hideaway Pond. Surface water and sediment
samples collected from both tributaries,  however, have indicated the presence of only low
concentrations of mercury, with the highest concentration detected at 0.02165 Ig/L in surface
water and 0.65598 mg/kg in sediment.

2.5       SUMMARY OF SITE RISKS

The human health and ecological risks associated with exposure to contaminated media at Site 17
were evaluated in the Addendum RI Report for Site 17. Residential use of the site was not
evaluated.  Institutional controls will be implemented to prevent future industrial and
residential land use and shallow groundwater use. Exposure to surface water is not expected
since the tributaries are too small to support fishing activities.

2.5.1     Human Health Risks

Exposure Pathways and Potential Receptors

Recreational users (adults and children)  and construction workers were evaluated as potential
receptors in the guantitative risk assessment Construction workers were evaluated for future
conditions only. Base workers were eliminated from further evaluation since no base personnel
are currently assigned to the site for routine or maintenance duties. Recreational users are
considered for current and future conditions. Ingestion of finfish was not evaluated for adult
recreational users because the small tributaries at the site are not large enough to support
edible-size game fish. Construction workers were evaluated for exposure to surface/subsurface
soil (0 to 12 feet),  while surface soil (0 to 2 feet) exposure was considered for all other
receptors.  Inhalation of volatile emissions and fugitive dust was evaluated gualitatively via a
comparison of site data to U.S. EPA Generic Soil Screening levels for transfers from soil to
air. Inhalation exposure was considered to be relatively insignificant since all detected soil
concentrations were less than the screening levels. Direct contact with surface water and
sediment is not anticipated at the site.  Therefore, pathways associated with these media were
not guantitatively evaluated.

Exposure Assessment

The list of COCs that were evaluated and their maximum exposure point concentrations are
presented on Table 2-2.

Toxicity Assessment

Cancer potency factors (CPFs) have been developed by U.S. EPA's Carcinogenic Assessment Group
for estimating excess lifetime cancer risks associated with exposure to potentially carcinogenic
chemicals.  CPFs, which are unitless, are multiplied by the estimated intake of a potential

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carcinogen,  in mg/kg/day,  to provide an upper-bound estimate of the excess lifetime cancer risk
associated with exposure at that intake level.  The term "upper bound" reflects the conservative
estimate of the risks calculated from the CPFs.  Use of this approach makes underestimation of
the actual cancer risk highly unlikely.

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                                TABLE 2-2
                              HUMAN HEALTH
        CHEMICALS OF CONCERN AND EXPOSURE POINT CONCENTRATIONS  (1)
                        SITE 17, 1400 AREA LANDFILL
             NAVAL SURFACE WARFARE CENTER, DAHLGREN, VIRGINIA
    Medium
Surface Soil
         Organics

  Chemical



Benzo(a)pyrene
Surface/Subsurface  Benzo(a)pyrene
Soil
Exposure Point
Concentration
   (mg/kg)

   0.4/1.5 (2)

   0.44/1.5 (2)
                                                                   Inorganics

                                                            Chemical



                                                             Arsenic

                                                             Arsenic
Exposure Point
Concentration
   (mg/kg)

 4.2/6.3 (2)

     6.7
                    Not evaluated  (3)      NA

                    Not evaluated  (4)      NA
                                     Not evaluated (3)

                                     Not evaluated (4)
                                               NA

                                               NA
Fish Tissue

Surface
Water/Sediment

NA Not applicable.

1  95 Percent upper confidence limits  (UCLs) on the arithmetic mean were used as exposure point
   concentrations for reasonable maximum exposure  (RME) and central tendency exposure  (CTE),
   unless otherwise noted.
2  Data set consists of less than 10 samples. Average and maximum concentrations were used  to
   evaluate the CTE and RME, respectively.
3  Tributaries at the site are not large enough to support edible game fish.
4  No human exposure is anticipated because of site-specific conditions  (i.e., inaccessibility,
   the presence of snakes and snapping turtles, etc.).
Cancer potency factors are derived from the results of human epidemiological studies or chronic
animal bioassays to which animal-to-human extrapolation and uncertainty factors have been
applied.

Reference doses  (RfDs) have been developed by the U.S. EPA for indicating the potential for
adverse health effects from exposure to chemicals exhibiting noncarcinogenic effects. RfDs,
which are expressed in units mg/kg-day, are estimates of lifetime daily exposure levels for
humans, including sensitive individuals. Estimated intakes of chemicals from environmental media
(e.g., the amount of a chemical ingested from contaminated drinking water) can be compared to
the RfD. RfDs are derived from human epidemiological studies or animal studies to which
uncertainty factors have been applied  (e.g., to account for the use of animal data to predict
effects on humans). These uncertainty factors help ensure that the RfDs will not underestimate
the potential for adverse noncarcinogenic effects to occur.

Risk Characterization
Excess lifetime cancer risks are determined by multiplying the intake level with the cancer

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potency factor. These risks are probabilities that are generally expressed in scientific
notation  (e.g., 1 x 10 -6). An excess lifetime cancer risk of 1 x 10 -6 indicates that, as a
plausible upper bound, an individual has a one in one million chance of developing cancer as a
result of site-related exposure to a carcinogen over a 70-year lifetime under the specific
exposure conditions at a site.

Potential concern for noncarcinogenic effects of a single contaminant in a single medium is
expressed as the hazard guotient  (HQ) (or the ratio of the estimated intake derived from the
contaminant concentration in a given medium to the contaminant's reference dose). By adding
the HQs for all contaminants within a medium or across all media to which a given population may
reasonably be exposed, the Hazard Index  (HI)  can be generated. The HI provides a useful
reference point for gauging the potential significance of multiple contaminant exposures within
a single medium or across media.

Adult Recreational User. The cumulative noncancer hazard index from exposure via ingestion of
and dermal contact with Site 17 soils under industrial land use conditions is less then 1
indicating little or no risk to human receptors. The cumulative ingestion and dermal contact
cancer risk is 1.5 x 10 -6 under a reasonable maximum exposure scenario, within U.S. EPA's
target risk range of 1 x 10 - 4 to 1 x 10 -6.

Child Recreational User. The cumulative noncancer hazard index and cancer risk associated with
ingestion and dermal contact exposure to surface and subsurface soil at Site 17 under industrial
land use scenario are less than 1 and 3.2 x 10 -6, respectively, under a reasonable maximum
exposure scenario. The cancer risk is within U.S. EPA's target risk range of 1 x 10 -4 to 1 x 10
-6 .

Construction Worker. The cumulative noncancer hazard index and cancer risk associated with
ingestion and dermal contact exposure to Site 17 soil under industrial land use conditions are
less than 1 and 7.2 x 10 -7, respectively, under a reasonable maximum exposure scenario.

Although the incremental cancer risk for the adult and child recreational users slightly
exceeded 1 x 10 -6, it is well within U.S. EPA's, target risk range of 1 x 10 -4 to 1 x 10 -6.
Since the risk to all other receptors is less than 1 x 10 -6 and the hazard indices for
receptors are less than 1.0, human health risks under industrial land use conditions for those
receptors are within acceptable risk ranges at Site 17.

2.5.2   Environmental Evaluation

The intent of the baseline ecological risk assessment  (ERA)  was to characterize potential
receptors and to estimate the potential hazard or risk to environmental receptors. Sample
locations were selected to detect potential groundwater contamination discharging to nearby
surface water bodies via the shallow aguifer as well as contaminants resulting from surface
water runoff. Samples were collected from marshy areas near the site as well as points in the
tributaries. Field work included sampling locations upstream, adjacent to, and downstream of
Site 17. Surface water, sediment, and macroinvertebrate community samples were taken from these
locations. In 1994, wetland identifications,  terrestrial wildlife inventories, vegetation
surveys, and macroinvertebrate inventories were performed to characterize the habitats
associated with Site 17.

Ecological effects guotients  (EEQs)  were derived for each COG in all media. Based on EEQs and
risk management factors, the following COCs are concerns:

     D  Mercury, lead, and zinc for surface water,

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     D  Benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, aroclor
        1260, chromium, and thallium for surface soils.

Based on risk management decisions made for this site, the marsh area sediments near monitoring
well GW17-13 will be remediated to address residual mercury contamination. Based on elevated
concentrations and risk levels of metals such as mercury and zinc in all three media, waste
debris at Site 17 appears to be the source of the COCs.

Exposure Pathways

The exposure pathways consist of dermal absorption and ingestion of chemicals from soil,
sediments, and surface water.

Exposure Assessment

Three contaminants in surface water (mercury, lead, and zinc),  five contaminants in sediment
(aroclor-1260,  carbazole, chlordane, cobalt, and cyanide)  and seven contaminants in surface
soils (benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, aroclor 1260,
chromium, and thalllium) were identified as COCs for ecological receptors. The EEQ for each of
these contaminants was greater than 1, indicating a preliminary remediation goal (concentration)
was exceeded.

Potential Receptors

The organisms most likely to be ecological receptors include mice, voles, rabbits,  earthworms
and other ground insects, fish, and a variety of birds. Because of the natural setting of Site
17 and the variety of nearby habitats, Site 17 is likely to have a diversity of wildlife.

Risk Characterization

Based on risk management factors as well as potential risk levels, mercury is a concern for
surface water,  benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, aroclor
1260, chromium,  and thallium are concerns for surface soils.

2.5.3   Development of Preliminary Remediation Goals

Contaminant fate and transport modeling is used to evaluate the potential for COCs identified by
the human health and ERA to migrate to other media and present unacceptable risks.  For example,
contaminants present in soils could migrate to groundwater or be carried with precipitation to
surface water or sediments at a site.  In order to evaluate this potential, fate and transport
modeling was conducted for Site 17 using the ECTran model. The model uses contaminant
properties, such as the adsorption coefficient, and site-specific characteristics,  such as
groundwater velocity, to predict acceptable levels of COCs in soil and groundwater that would be
protective of surface water and sediment.  Using regulatory criteria for surface water  (water
guality criteria) and toxicity data for sediment, preliminary remediation goals  (PRGs) are
developed during modeling to determine if existing levels of COCs are acceptable. A complete
discussion of the use of modeling and assumptions is presented in Appendix A of the Site 17 FS.

Potential migration of COCs evaluated for Site 17 by the ECTran model included:

     D  Surface soil to surface water via runoff
     D  Surface soil to sediment via runoff
     D  Surface soil to surface water via groundwater
     D  Subsurface soil to surface water via groundwater

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     D  Subsurface soil to sediment via groundwater
     D  Groundwater to surface water
     D  Groundwater to sediment

Based on potential migration, the following remedial action objectives  (RAOs) are anticipated
for Site 17 soil, sediment, and groundwater to address the primary exposure pathways. RAOs, may
be modified (become more stringent) during the Remedial Design based on more detailed
evaluation.

     D  Prevent ecological receptors from being exposed to benzo(a)anthracene,
        benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, and Aroclor 1260 present in
       surface soils at concentrations  greater than 1.0 mg/kg (for each).

     D  Prevent ecological receptors from being exposed to chromium and thallium present in
        surface soils at concentrations greater than 0.4 mg/kg and 1.0 mg/kg, respectively.

     D  Prevent mercury at concentrations greater than 0.14 Ig/L present in groundwater from
        migrating to surface water and causing adverse effects in ecological receptors.

     D  Prevent ecological receptors from being exposed to mercury in sedimient in the marsh
       east of the landfill where mercury was detected at 0.65598 mg/kg  (although the mercury
        concentration in sediment did not exceed the PRG, it was decided that mercury
        contaminated sediments should be removed as a precautionary measure).

2.6     DESCRIPTION OF ALTERNATIVES

A detailed analysis of the possible remedial alternatives for Site 17 is included in the Site 17
Feasibility Study report. The detailed analysis was conducted in accordance with the U.S. EPA
document entitled Guidance for Conducting Remedial Investigations and Feasibility Studies under
CERCLA and the National Oil Hazardous Substances Pollution Contingency Plan.

For every alternative, except the No Action alternative, an institutional control plan will be
developed as part of remedial action design and will include: access controls, signs along the
perimeter of the site, restrictions on shallow groundwater use for drinking water, description
of land use controls in the base master plan, periodic inspection, monitoring, and re-evaluation
of land use controls, annual certification that institutional controls are in place,
notification to the U.S. EPA and state regulators whenever the Navy anticipates any major
changes in land use restrictions, public notice, and a deed notification.

The following specific institutional controls are part of every alternative except the No Action
alternative, and shall be undertaken within 90 days of completion of remedial construction: a
real property description notation, Base Master Plan notations,  and limited site access. The
Base Master Plan shall note the area as one in which residential development can not occur,
shallow groundwater can not be used, and site access shall be limited. A notation shall be filed
in the real property file maintained at EFA Ches for this site indicating the extent of the area
and the fact that solid wastes are present.

The institutional controls shall also include the following: within 90 days after completion of
the remedy, the Navy shall produce a survey plat prepared by a professional land surveyor
registered by the Commonwealth of Virginia indicating the location and dimensions of disposal
area and the extent of groundwater contamination. Monitoring well locations shall be included
and identified on the survey plat. The plat shall contain a note, prominently displayed, which
states the owner's future obligation to restrict disturbance (excavation or construction) of the
property; post-closure use of the property shall prohibit residential use, access or use of

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groundwater underlying the property for any purpose except monitoring, and the function of the
monitoring systems shall not be disturbed. When landfill closure is complete, the owner of the
property shall submit the survey plat to the local recording authority, and shall record a
notation with the deed (or some other instrument which is normally examined during title search
at the local land recording authority) notifying any potential purchaser of the property that
the land has been used to manage solid waste and the integrity of the cover system or the
function of the monitoring system may not be disturbed.

A summary of the remedial alternatives which were developed to address contamination associated
with Site 17 is presented below.

Alternative 1 - No Action

CERCLA reguires an evaluation of the No Action alternative. Under this alternative, no action
would be taken to reduce the toxicity, mobility, or volume of the contaminated surface soil or
groundwater at Site 17. Alternative 1 serves as a baseline against which the effectiveness of
other alternatives is measured.

The following costs are associated with this alternative:

     Present Worth ($):     15,550/5 yr (Estimated administrative cost of 5-year review of
                            remedial action over a 30-year period
     Time to Implement:     0 months

Alternative 2 - Commonwealth of Virginia Sanitary Landfill Cap (Soils and Waste/Fill);
Excavation, and Consolidation  (Waste/Fill Within 100 Feet of Tributaries); Excavation and A.)
On-site Consolidation or B.)  Off-site Landfilling (Marsh Sediments); Natural Attenuation
(Groundwater); Institutional Controls (Soils, Wastefill, Sediments, Surface Water, and
Groundwater).

This alternative consists of remedial actions conducted on surface soils, waste/fill, marsh
sediments, and groundwater at Site 17. The components of this alternative are as follows:

     D  The landfill area would be capped to address surface soil contamination and to comply
        with Commonwealth of Virginia regulations 9 VAC 20-80-210 and 9 VAC 20-80-250,
        which reguire a cap over an unpermitted sanitary landfills consisting of the following
        minimum components:

               6-inch vegetative and protective layer
               18-inch infiltration layer with a hydraulic conductivity less than or egual
               to any natural soils below the waste but not greater than 1 x 10 -5 cm/s

     D  Waste/fill within 100 feet of the tributaries would be excavated to address Commonwealth
        of Virginia regulation 9 VAC 20-80-250 which reguires a 100 foot setback from waste
        material. It is estimated that 17,600 cubic yards  (cy) would have to be excavated and
        consolidated beneath the cap.

     D  The marsh area near GW17-13 would be remediated to address residual mercury
        contamination, even though the sediment criteria are not exceeded. Two options have
        been developed:

        Option A - Excavate 970 cy of marsh sediment stabilize, and consolidate on site under
        the landfill) cap.

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        Option B - Excavate 970 cy of marsh sediment and transport to an off-site treatment and
        disposal facility.

     D  The movement of groundwater at Site 17 would be slightly reduced after the placement
        of the sanitary landfill cap. This reduction in groundwater flow would reduce the mass
        of mercury contamination as it discharges into the marshes, ponds,  and tributaries
       adjacent to Site 17. Mercury concentration levels are already very low in groundwater.

     D  Institutional controls would be implemented to limit future site land use. Residential
       and industrial/commercial land use restrictions will be implemented. An institutional
       control plan will be developed as part of the remedial action design and will include:
       access controls,  signs along the perimeter of the site,  restrictions on shallow
       groundwater use for drinking water, description of land use controls in the base master
       plan,  periodic monitoring and re-evaluation of land use controls, annual certification
       that institutional controls are in place, notification to the U.S. EPA and state
       regulators whenever the Navy anticipates any major changes in land use restrictions,
       public notice, and a deed notification. Off-site migration of impacted groundwater is
       not anticipated to be a human health concern since the discharge location  (tributaries)
       is located immediately adjacent to the site. Therefore,  it is unlikely that there will
       be downgradient off-site groundwater users. Monitoring of sediment,  surface water, and
       groundwater will be conducted to ensure that no adverse effects to ecological receptors
       are occurring due to release of Site 17 contaminants. This alternative maintains
       institutional controls on the media of concern until a residential land-use scenario has
       been evaluated in the risk assessment and a decision is made at that time to either
       maintain or delete the institutional controls on one or all of these media.

The following costs are associated with this alternative:

     Capital  ($):            Option A: 2,100,000
                             Option B: 2,300,000
     Operating/Maintenance
           (O&M)($/Yr):      37,000/yr + 15,550/5 yr
     Present Worth           Option A: 2,500,000
                             Option B: 2,700,000
     Time to Implement       6 months

Alternative 3 - Impermeable Landfill Cap  (Soils and Waste/Fill); Excavation and Consolidation
(Waste/Fill Within 100 Feet of Tributaries); Excavation and A.) Consolidation or B.) Offsite
Disposal  (Marsh Sediments); Slurry Wall  (Groundwater); Institutional Controls  (Soils,
Waste/Fill, Sediments, Surface Water, and Groundwater).

This alternative consists of remedial actions conducted on surface soils, waste/fill, marsh
sediments, and groundwater at Site 17. Alternative 3 is essentially a more aggressive version of
Alternative 2. The components of this alternative are as follows:

     D  The landfill area would be capped to address surface soil contamination and to comply
        with Commonwealth of Virginia regulation 9 VAC 20-80-250. This cap, however, would
        be more impermeable than the one described in Alternative 2 and would consist of the
        following components:

               6-inch vegetative and protective layer
               12-inch drainage layer

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               Flexible Membrane Liner  (FML)  (Hydraulic Conductivity 4 x 10 -13cm/sec)
               12-inch select fill

     D  To further limit discharge of shallow groundwater contamination to surface water, a
       slurry wall would be placed on both the northern and southern borders of the landfill to
       cut off upgradient groundwater flow into the site.

     D  The waste/fill within 100 feet of the tributaries' component is the same as Alternative
        2.

     D  The marsh area sediment component is the same as Alternative 2.

     D  The instititional controls components are the same as Alternative 2.

The following costs are associated with this alternative:

     Capital  ($)              Option A: 4,200,000
                             Option B: 4,400,000
     Operating/Maintenance
              (O&M)($/Yr):   37,000/yr + 15,550/5 yr
     Present Worth($):      Option A: 4,600,000
                             Option B: 4,850,000
     Time to Implement:      6 months

Alternative 4 - Soil Cap and Phytoremediation  (Soils and Waste/Fill); Excavation, and
Consolidation (Waste/Fill) Within 100 Feet of Tributaries; Excavation, and Offsite Landfilling
(Marsh Sediments); Phytoremediation  (Groundwater); Institutional Controls (Soils, Waste/Fill,
Sediments, Surface Water, and Groundwater).

This alternative consists of remedial actions conducted on surface soils and wastefill, marsh
sediments, and groundwater at Site 17. The components of this alternative are as follows:

     D  The landilll area would be capped to address surface soil contamination with a 2-foot-
        thick vegetative soil layer. Natural vegetation such as hybrid poplars and evergreens
        would be planted on this layer to control erosion and reduce infiltration and
       groundwater discharge to the tributaries via evapotranspiration and as a habitat
       enhancement.  The alternative cap would achieve an eguivalent net reduction in
       infiltration and provide eguivalent erosion protection per 9 VAC 20-80-250.
       (Infiltration calculations using the  HELP model were performed to determine whether
       there can be a functional eguivalency between a Commonwealth of Virginia sanitary
       landfill cap (Alternative 2)  and a soil cap coupled with phytoremediation (Alternative
       4). According to these calculations,  there is a similar reduction of infiltration
       through the landfill using either the sanitary landfill cap or the soil cap with
       phytoremediation.)

     D  The waste/fill within 100 feet of the tributaries' component is the same as Alternative
       2.

     D  The marsh sediment component is the same as Alternative 2 except that Option A is not
        included.

     D  Groundwater discharging to surface water bodies at Site 17 would be contained by
        reducing infiltration and evapotranspiration using natural vegetation such as hybrid
        poplars and evergreens.

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     D  The institutional control components are the same as Alternative 2.
The following costs are associated with this alternative:

     Capital($):              2,400,000
     Operating/Maintenance
             (O&M)($/Yr):    37,000/yr + 15,550/5 yr
     Present Worth  ($):       2,800,000
     Time to Implement:       6 months to 12 months

2.7  SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES

The remedial alternatives described in Section 2.6 were evaluated in the Feasibility Study
against nine criteria identified in the NCP, as presented below.

2.7.1    Threshold Criteria

Overall Protection of Human Health and the Environment

Alternative 3 provides a high level of overall protection to human health and the environment by
preventing transport of, and plant and animal contact with, contaminants through the containment
of wastes within the landfill and control of groundwater passing through the landfill.
Alternative 4 has the potential to provide a similar or a higher level of protection because the
trees may uptake more groundwater than was used as a basis for evaluation. Alternative 2
provides a lower level of protection because, groundwater discharge is not controlled.
Alternative 1 provides the least overall protection because no action would be taken to reduce
contaminant movement and contaminated soil and sediment is neither removed nor contained.

Option B (off site disposal of marsh sediment) provides a higher level of overall protection
than Option A (on site disposal of marsh sediment)  because the contaminated sediment is removed
from Site 17 and disposed in a facility designed to handle similar materials.

Every alternative except the No Action alternative implements measures to control sources of
contamination and exposure to humans and the environment to residual contamination, as
necessary to protect human health and the environment. This includes permanent notification in
local land records of groundwater use restrictions in order to control exposure of humans to
residual contamination in groundwater.

Compliance with ARARs and To Be Considered  (TBCs)

All the alternatives except Alternative 1 would achieve remediation goals, ARARs, and TBCs.
Alternatives 3 and 4 are anticipated to achieve these objectives in a shorter time frame than
Alternative 2 due to the time reguired for natural processes to reduce concentrations of mercury
in groundwater.  Alternatives 2, 3, and 4 would achieve these objectives for surface soil.
Alternative 1 would not meet remediation goals, ARARs, and TBCs because no action would be taken
to reduce contaminant movement and contaminated soil and sediment is neither removed nor
contained.  Both Option B (off-site disposal of marsh sediments) and Option A (on-site disposal
of marsh sediments) would achieve remediation goals, ARARs, and TBCs.

2.7.2    Primary Balancing Criteria

Reduction of Toxicity, Mobility, and Volume Through Treatment

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Alternatives 3 and 4 reduce the mobility of contaminants present in the groundwater by
controlling groundwater flow to the tributaries. Alternative 4 has the potential to control
groundwater flow to the tributaries to a greater degree than in Alternative 3 both by
controlling rainfall infiltration and by direct groundwater withdrawal from underneath the
landfill. Alternative 2 provides negligible control of groundwater flow to the tributaries.
Alternatives 2, 3, and 4 all reduce the mobility of contaminants in the surface soil and
sediment by capping the landfill and removing contaminated sediment, respectively. Alternative 1
does not provide any reduction in contaminant mobility in groundwater, surface soil, and
sediment. None of the alternatives reduce toxicity or volume of waste through treatment because
it would be cost prohibitive due to the large volume of waste materials present at the site.

Option B (off-site disposal of marsh sediments) provides a better control of contaminants in
sediment than Option A (on-site disposal of marsh sediments)  because the materials are removed
from Site 17 and disposed in a facility designed to handle similar waste.

Long-Term Effectiveness

Alternative 4 has the potential to be more effective than Alternative 3 for groundwater control.
Alternative 2 addresses groundwater only through natural processes to reduce concentrations of
mercury in groundwater, and, therefore, is not as effective as Alternatives 3 and 4.
Alternatives 2, 3, and 4 will be egually effective in reducing the risk to ecological receptors
contacting surface soils. Alternative 1 would not be effective in the long term because it does
not protect the environment.

Option B (off-site disposal of marsh sediments) is expected be a more effective long term option
than Option A  (on-site disposal of marsh sediments) because the materials are removed from Site
17 and disposed in a facility designed to handle similar waste. Option A would present the
possibility of contaminant migration from the site.

Short-Term Effectiveness

Alternative 3 is expected to be somewhat more effective than Alternative 4 in the short term
because contaminants in the groundwater are controlled sooner. Alternative 2 is not expected
be effective in the short term because the movement of contaminants from the groundwater to the
tributaries would not be significantly reduced for many years. Alternative 1 would not be
effective in the short term because it does not protect the environment.

Option B (off-site disposal of marsh sediments) is expected be a more effective short-term
option than Option A (on-site disposal of marsh sediments) because the materials are removed
from Site 17 soon after excavation is complete. Option A would present additional short-term
risks during construction because the contaminated sediment would require additional handling
and preparation for disposal under the landfill cap.

Implementabillity

Alternative 4 and Option B are the most easily implemented, although all the alternatives are
implementable using conventional, well-demonstrated, and commercially available technologies.
Alternative 1 requires no implementation. Alternative 2 would involve construction of a
multilayered cap which would involve more significant effort. Alternative 3 would be somewhat
more complicated because a more complex cap and slurry wall would be constructed. Option A
would be more complicated than Option B because it would require additional handling and
preparation of contaminated sediment for disposal under the landfill cap.

Cost

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Alternative 4 is slightly more costly ($2,800,000) than Alternative 2 with Option A ($2,500,00)
while Alternative 3 with Option B is the highest cost alternative ($4,850,000).

2.7.3    Modifying Criteria

State Acceptance

The Virginia Department of Environmental Quality, on behalf of the Commonwealth of Virginia,
has reviewed the information available for this site and has concurred with this ROD and the
selected remedy identified below. A copy of the concurrence letter from the Commonwealth of
Virginia is attached as Appendix A.

Community Acceptance

Community acceptance summarizes the public's general response to the alternatives described
in the Proposed Plan and the Feasibility Study. No written comments were received during the
thirty-day comment period that began on August 18, and ended on September 16, 1998. There
were no formal comments or guestions received at the Proposed Plan Public Meeting held on
August 27, 1998. The background on community involvement is included in the Responsiveness
Summary, Section 3.0 of the ROD.

2.8      THE SELECTED REMEDY

Alternative 4 is the selected remedy, using phytoremediation to address both soils and
groundwater. Figure 2-7 depicts the conceptual remediation plan and Figure 2-8 depicts the
layout. Based on available information and the current understanding of site conditions,
Alternative 4 coupled with option B appears to provide the best balance with respect to the nine
NCP evaluation criteria. In addition, the selected alternative is anticipated to meet the
following statutory reguirements:

     D  Protection of human health and the environment.
     D  Compliance with ARARs.
     D  Cost-effectiveness.

The selected remedy will address the surface soil contamination at Site 17 and provide for the
reduction of groundwater contamination beneath the site. The institutional controls will further
protect human health and the environment by limiting future land use and by providing long-term
monitoring.




Institutional controls will be implemented to limit future site land use. For Site 17, an
institutional control plan will be developed as part of the remedial action design and include:
access controls, signs along the perimeter of the site, restrictions on shallow groundwater use
for drinking water, description of land use controls in the base master plan, periodic
inspection, monitoring, and re-evaluation of land use controls, annual certification that
institutional controls are in place, notification to the U.S. EPA and state regulators whenever
the Navy anticipates any major changes in land use restrictions, public notice,  and a deed
notification.

The Navy shall institute the following institutional controls within 90 days of completion of
the installation of the remedy: a real property description notation, Base Master Plan

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notations, and limited site access. The Base Master Plan shall note the area as one in which
residential development can not occur, shallow groundwater can not be used, and site access
shall be limited. A notation shall be filed in the real property file maintained at EFA Ches (US
Navy) for this site indicating the extent of the area and the fact that solid wastes are
present.

The institutional controls shall also include the following: within 90 days after completion of
the remedy, the Navy shall produce a survey plat prepared by a professional land surveyor
registered by the Commonwealth of Virginia indicating the location and dimensions of disposal
area and the extent of groundwater contamination. Monitoring well locations should be included
and identified on the survey plat. The plat shall contain a note, prominently displayed, which
states the owner's future obligation to restrict disturbance (excavation or construction) of the
property; post-closure use of the property shall prohibit residential use, access or use of
groundwater underlying the property for any purpose except monitoring, and the function of the
monitoring systems shall not disturbed. When landfill closure is complete, the owner of the
property shall submit the survey plat to the local recording and shall record a notation with
the deed  (or some other instrument which is normally examined during title search at the local
land recording authority) notifying any potential purchaser of the property that the land has
been used to manage solid waste and the integrity of the cover system or the function of the
monitoring system may not be disturbed.

The Navy shall institute groundwater monitoring to ensure that remedial action objectives (RAOs)
are being maintained. The freguency of analysis and the length of time for monitoring shall be
developed in the Operation and Maintenance Plan.

The Navy shall monitor the surface waters and sediments in the tributaries adjacent to Site 17
to ensure RAOs are being maintained. The freguency of analysis, types of analyses,  and the
length of time for monitoring shall be developed in the Operation and Maintenance Plan.

Based on available information and the current understanding of site conditions, Alternative 4
appears to provide the best balance with respect to the nine NCP evaluation criteria. In
addition, the selected alternative its anticipated to meet the following statutory reguirements:

D  Protection of human health and the environment.
D  Compliance with ARARs.
D  Cost-effectiveness.

The institutional controls will further protect human health and the environment by limiting
future land use and by providing continuous monitoring.

2.8.1    Peformance Standards

The remedy shall be capable of managing residuals and achieving all RAOs within the boundaries
of Site 17 and shall meet all ARARs and TBCs for the site.

Sediment Removal

All marsh area sediment, to be excavated in the areas identified on Figure 2-8, shall be removed
and disposed off-site.

Soil Cap

The soil cap shall be designed, constructed, operated,  and maintained to meet the performance
reguirements of RCRA Subtitle D regulations specified in 40 CFR °° 258.60-61 and Virginia Solid

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Waste Management Regulations (VSWMR),  9 VAC 20-80-250 (Sanitary Landfill).

The soil cap design shall incorporate phytoremediation to achieve a net reduction in
infiltration and provide eguivalent erosion protection per 9 VAC 20-80-250.

Waste/Fill Excavation

Waste/fill within 100 feet of the tributaries and pond shall be excavated to provide a 100 foot
setback from waste material as specified in 9 VAC 20-80-250. The excavated material shall be
consolidated beneath the soil cap.

Monitoring Wells

A groundwater monitoring network shall be implemented in accordance with RCRA and VSWMR.
It shall be installed at the perimeter of the unit to evaluate any future contaminant transport.
The location and number of monitoring wells, the frequency of analyses, and the types of
analyses shall be determined in the site design and operation and maintenance documents. These
documents must be approved by the EPA and the Commonwealth of Virginia. Groundwater monitoring
shall be determined in the site design and operation and maintenance documents, per 9 VAC
20-80-310  (Corrective Action Program). The wells shall be installed according to RCRA and
Commonwealth of Virginia construction requirements.

Surface Water and Sediment Monitoring

A surface water and sediment sampling and monitoring plan shall be developed as part of the
Operation and Maintenance (0 & M) Plan. The location and number of sampling locations, the
frequency of analyses, the types of analyses, and the duration of monitoring shall be determined
in the 0 & M Plan. This plan must be approved by the EPA and the Commonwealth of Virginia.

Institutional Controls

Institutional controls will be implemented to limit future site land use. For Site 17, an
institutional control plan will be developed as part of the remedial action design and include:
access controls, signs along the perimeter of the site,  restrictions on shallow groundwater use
for drinking water, description of land use controls in the base master plan, periodic
inspection, monitoring, and re-evaluation of land use controls, annual certification that
institutional controls are in place, notification to the U.S. EPA and state regulators whenever
the Navy anticipates any major changes in land use restrictions, public notice, and a deed
notification.

The Navy shall institute the following specific institutional controls within 90 days of
completion of all remedial actions: a real property description notation, Base Master Plan
notations, and limited site access. The Base Master Plan shall note the area as one in which
residential development can not occur, shallow groundwater can not be used, and site access
shall be limited.

A notation shall be filed in the real property file maintained at EFA Ches  (US Navy)  for this
site indicating the extent of the area and the fact that solid wastes are present.

The institutional controls shall also include the following: Within 90 days after completion of
the remedy, the Navy shall produce a survey plat prepared by a professional land surveyor
registered by the Commonwealth of Virginia indicating the location and dimensions of the
disposal area and the extent of groundwater contamination. Monitoring well locations should be
included and identified on the survey plat. The plat shall contain a note, prominently

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displayed, which states the owner's future obligation to restrict disturbance  (excavation or
construction) of the property; post-closure use of the property shall prohibit residential use
and access or use of groundwater underlying the property for any purpose except monitoring and
shall not disturb the function of the monitoring systems. When landfill closure is complete, the
owner of the property shall submit the survey plat to the local recording authority, and shall
record a notation with the deed  (or some other instrument which is normally examined during
title search at the local land recording authority) notifying any potential purchaser of the
property that the land has been used to manage solid waste and the integrity of the cover system
or the function of the monitoring system may not be disturbed.

The Navy shall institute groundwater monitoring to ensure remedial action objectives (RAOs)  are
being maintained. The freguency of analysis and the length of time for groundwater, surface
water, and sediment monitoring shall be developed in the Operation and Maintenance Plan.

2.9      STATUTORY DETERMINATIONS

Remedial actions must meet the statutory reguirements of Section 121 of CERCLA as discussed
below. Remedial actions undertaken at National Priority List  (NPL) sites must achieve adeguate
protection of human health and the environment, comply with ARARs, be cost-effective, and
utilize, to the maximum extent practicable, permanent solutions and alternative treatment or
resource recovery technologies. Also, remedial alternatives that reduce the volume, toxicity,
and/or mobility of hazardous waste as the principal element are preferred. The following
discussion summarizes the statutory reguirements that are met by the selected remedial
alternative.

2.9.1    Protection of Human Health and the Environment

The soil cap will be protective of human health and the environment by preventing direct
exposure to contaminated soil and reducing the potential of contaminant migration to the surface
water and sediment via groundwater. Phytoremediation utilizing natural vegetation, such as
hybrid poplars and evergreens, will also minimize the potential of groundwater contaminant
migration to surface water and sediment. Removal of contaminated marsh sediment from the eastern
marsh will remove the potential threat of this waste from both human and ecological receptors.
Implementation of institutional controls will ensure that the site will not be used for any
purpose in the future that could damage the cap and potentially expose human and ecological
receptors to the waste in the landfill.

The selected remedy implements measures to control sources of contamination and exposure to
humans and the environment to residual contamination, as necessary to protect human health and
the environment. These measures include permanent notification in local land records of
groundwater use restrictions in order to control exposure of humans to residual contamination in
groundwater, and control of groundwater with phytoremediation in order to control release of
contaminants to the environment to levels which are protective of the environment.

2.9.2    Compliance with ARARs

The selected remedy (Alternative 4) will meet all identified ARARs. The selected remedy will
protect ecological receptors in soils, sediments, and surface water from metals, SVOCs, and PCBs
in surface soils and from mercury in groundwater. A mechanism (monitoring) will be implemented
to evaluate the performance of the selected alternative. The waste in the landfill will not be
situated within 100 feet of a flowing surface water body (the tributaries).

Alternate measures to control sources of contamination and exposure to humans or the
environment to residual contamination may be implemented provided: the groundwater protection

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standard cannot be practically achieved; the groundwater is not currently or reasonably expected
to be a source of drinking water and is not hydraulically connected with waters to which
contaminants may migrate in concentrations that would exceed applicable standards; and the
alternate measures are consistent with the overall objective of the remedy,  i.e.,  to control the
sources of releases so as to reduce or eliminate, to the maximum extent practicable, further
releases of solid waste constituents into the environment that may pose a threat to human health
or the environment [9 VAC 20-80-310.B.2; B.5; C.3]. The selected remedy will satisfy these
criteria.

The ARARs identified for the remedial action at Site 17 are provided in Appendix C.
2.9.3    Cost-Effectivenes

The selected remedy is cost-effective because it would provide overall effectiveness
proportional to the cost. The selected remedy will achieve remediation goals more guickly and
efficiently than other alternatives, provide greater long-term protection of human health and
the environment, and meet all identified ARARs.

2.9.4    Utilization of Permanent Solutions and Alternative Treatment Technologies or
         Resource Recovery Technologies to the Maximum Extent Practible

The selected alternative uses a permanent solution, phytoremediation. Phytoremediation is a
permanent solution and is an appropriate remedy for landfill waste and soils contaminated with
SVOCs, metals, and PCBs.  Containment in the form of phytoremediation is functionally eguivalent
to capping.

2.9.5    Preference for Treatment as a Principle Element

The selected remedial action does not use treatment technologies for this site because cost and
technical considerations make treatment impracticable.

2.9.6    Documentation of Significant Changes

The selected remedy, Alternative 4, is the same alternative identified as the recommended
alternative in the Proposed Remedial Action Plan and that was presented to the public at the
public meeting held August 27, 1998.

There were no significant changes to the recommended remedial action alternative in the
Proposed Plan.

                               3.0 RESPONSIVENESS SUMMARY

The selected remedy for Site 17 is Alternative 4. No written comments, concerns, or questions
were received by the Navy, U.S. EPA, or the Commonwealth of Virginia during the public comment
period from  August 18, 1998 to September 16, 1998. A public meeting was held on August 27,
1998 to present the Proposed Plan for Site 17 and to answer any guestions on the Proposed Plan
and on the documents in the information repositories. A 30-minute presentation was provided
during which informal guestions were addressed. A period was set aside for formal guestions to
be recorded by the court reporter. No formal guestions were asked during this period.

A summary of the informal guestions that were asked at the public meeting is provided in
Appendix B. Additionally, a copy of the certified transcript of the Public Meeting is attached
in Appendix B.

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3.1      BACKGROUND ON COMMUNITY INVOLVEMENT

The Navy and NSWCDL have had a comprehensive public involvement program for several years.
Starting in 1993, a Technical Review Committee (TRC) has met, on average, twice a year to
discuss issues related to investigative activities at NSWCDL. The TRC was comprised of mostly
governmental personnel, however a few private citizens attended the meetings.

In early 1996, the Navy converted the TRC into a Restoration Advisory Board  (RAB)  and 8-10
community representatives joined. The RAB is co-chaired by a community member and has held
meetings approximately every four to six months.  The Feasibility Study and the Proposed Plan for
Site 17 were both discussed at the RAB meetings and a Site 17 tour was undertaken during a
special RAB meeting.

Community relations activities for the final selected remedy include:

The documents concerning the investigation and analysis at Site 17, as well as a copy of the
Proposed Plan were placed in the information repository at the NSWCDL General Library and the
Smoot Memorial Library in King George, Virginia.

Newspaper announcements on the availability of the documents and the public comment
period/meeting date was, placed in the Freelance Star Newspaper on August 18, 1998 and The
Journal, on August 19, 1998.

The Navy established a 30-day public comment period starting August 18, 1998 and ending
September 16, 1998 to present the Proposed Plan.  No written comments were received during the
30-day public comment period.

A Public Meeting was held August 27, 1998 to answer any guestions concerning the Site 17
Proposed Plan. Approximately 11 people, including federal, state and local government
representatives attended the meeting.

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                                                APPENDIX A

                                           VIRGINIA CONCURRENCE LETTER
 
                                         COMMONWEALTH of VIRGINIA
                                   DEPARTMENT OF ENVIRONMENTAL QUALITY
                                                                                                       Dennis H. Treacy
    James S. Gilmore, III                                                                                     Director
       Governor              Street address: 629 East Main Sreet, Richmond, Virginia 23219
                             Mailing address: P.O. Box 10009, Richmond, Virginia 23240         (804) 698-4000
  John Paul Woodley, Jr.       Fax (804) 698-4500 TDD (804) 698-4021                           1-800-592-5482
Secretary of National Resoures         http://www.deg.state.va.us

                                             September 30, 1998

    Mr. Abraham Ferdas,  Division Director
    Hazardous Site Cleanup Division (3HSOO)
    U.S. Environmental Protection Agency, Region III
    1650 Arch Street
    Philadelphia, PA 19103-2029

    Re:  Record of Decision for Site 17  (1400 Area Landfill), Naval Surface Warfare Center,
         Dahlgren, Virginia

    Dear Mr. Ferdas:

         The Virginia Department of Environmental Quality  (VDEQ) staff has reviewed the above
    referenced Record of Decision  (ROD) for Site 17 (1400 Area Landfill) We concur with the
    selected remedial alternative as outlined in the ROD dated September 1999.

         Should you have any guestions concerning this letter, please feel free to contact Dave
    Gillispie at  (804) 698-4209.



        cc:  Ryan Mayer - ChesDiv
         Ann Swope - NSWC-Dahlgren
         Bruce Beach - EPA Region III
         Erica Dameron - VDEQ
         Dave Gillispie - VDEQ

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                                 APPENDIX B

                    SUMMARY OF INFORMAL COMMENTS

During the Public Meeting held on August 27, 1998, an overview of the Proposed Remedial
Action Plan for Site 17 was presented during a 30-minute period. The Navy,  the Commonwealth
of Virginia, or the EPA have received no written comments from the public.  During the
presentation the following comments were received from attendees. These comments included
the following:

                    Summary of Comments Received during the Public Meeting

1   Why is phytoremediation better than the slurry wall for controlling the transport of
    contaminants in groundwater?

    It was explained that groundwater in the landfill area is relatively shallow. Vegetation
     that utilizes significant volumes of water and that are planted close  together can
   hydraulically impact groundwater so that contaminated groundwater does not discharge to
   the adjacent tributaries and pond.  In addition, some of the contaminants in groundwater
   may be sorbed by the plant roots and thereby reduce the opportunities for being
   transported to the adjacent tributaries and pond.  The vegetation will also provide an
   enhanced habitat for birds and other animals.  The slurry wall, as proposed would lower
   the groundwater level but wouild not provide the ability for contaminants to sorb to
   plants and to be contained. Additionally, the slurry wall would not provide an enhanced
   habitat.

2   Is the depth of the soil cap much greater than the landfill caps as indicated in the
    Proposed Remedial Action Plan Summary for Site 17  (Figure 3)?

    It was explained that the figure was not drawn to scale. The depth of the caps ranged
    from 1 to 2.5 feet. The soil cap would include a 2-foot vegetative soil layer that would
    enhance the growth of trees and shrubs. Unlike the landfill caps that would be designed
    to reduce rainfall infiltration through the soil into the buried waste material, the
   soil cap would allow rainfall infiltration to occur so that the vegetation removes the
   infiltrating water via transpiration. The vegetation would consist primarily of large
   trees that tend to uptake large volumes of water.

3   How deep are the plant roots?

    The tree roots would be deep enough to remove groundwater that is approximately 1 to 6
    feet below the ground surface.

4   In Alternative 2, why is a slurry wall both north and south of the landfill?

    It was explained that groundwater north and south of the landfill flows toward the
   center of the landfill and radially toward the tributaries east and west of the
   landfill. Therefore, it would be necessary to control upgradient uncontaminated
   groundwater north and south of the landfill to prevent the contact with buried waste
   within the landfill and potential transport of contaminants to the tributaries.

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 1                    NAVAL SEA SYSTEMS COMMAND

 2                   NAVAL SURFACE WARFARE CENTER
                           DAHLGREN DIVISION
 3

 4                          PUBLIC MEETING

 5
                    THURSDAY,  AUGUST 27, 1998, 7:00 P.M.
 6                     KING GEORGE COUNTY COURTHOUSE
                         KING GEORGE, VIRGINIA
 7
                     PROPOSED REMEDIAL ACTION PLAN
 8                    Site 17, 1400 Area Landfill

 9

10

11

12
      USEPA Region III
13    Hazardous Site Cleanup Division
      Federal Facilities Section
14    Mr. Bruce Beach
      1650 Arch Street,  Philadelphia, Pennsylvania 18107
15
      Virginia Department of Environmental Quality
16    Mr. David Gillispie
      629 East Main Street, Richmond, Virginia 23219
17
      Public Affairs Office
18    Commander,  Naval Surface Warfare Center
      Ms. Jennifer Wilkins
19    17320 Dahlgren Road, Mail Code CD06 Dahlgren, Virginia 22448

20

21                          Reported by:  Lola Gail Serrett
                FRANCES K. HALEY & ASSOCIATES, Court Reporters
          10500  Wakeman Drive, Suite 300, Fredericksburg, VA 22407
               PHONE:  (540)  898-1527    FAX:  (540) 898-6154

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  1   August 27, 1998:

  2

  3            There were no formal questions on the floor at this

  4              meeting.

  5

  6

  7
  9

 10

 11

 12

 13

 14

 15

 16

 17

 18

 19

 20

 21
                   FRANCES K. HALEY & ASSOCIATES, Court Reporters
             10500 Wakeman Drive, Suite 300, Fredericksburg, VA 224077
                     PHONE:  (540) 898-1527    FAX:  (540) 898-6154
1                     CERTIFICATE OF COURT REPORTER

2

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 3              I,  Lola Gail Serrett,  hereby certify that I was the

 4    Court Reporter at the Public meeting held at King George

 5    Courthouse,  King George,  Virginia, on August 27,  1998, at the

 6    time of the meeting herein.

 7              I further certify that the foregoing transcript is a

 8    true and accurate record of the proceeding herein.

 9              Given under my hand this 30th day of August, 1998.

10

11
      
12

13

14

15

16

17

18

19

20

21
                    FRANCES K. HALEY & ASSOCIATES, Court Reporters
               10500 Wakeman Drive, Suite 300, Fredericksburg, VA 22407
                      PHONE:  (540)  898-1527  FAX: (540)  898-6154

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                                       APPENDIX C

                     APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
                                SITE 17:1400 AREA LANDFILL
                                NSWCDL, DAHLGREN, VIRGINIA
   ARAR or TBC

1. LOCATION SPECIFIC
   Regulation
                                                Classification
                                 Requirement Synopsis
                                                            Applicability to Remedial
                                                                    Alternatives
Endangered Species
Act of 1978
Virginia Endangered
Species Regulations
16 USC 1531 50
C.F.R. Part 402
4 VAC 15-20-130
to 140
Appplicable
Applicable
Act requires federal agencies to ensure that
any action authorized by an agency is not likely
to jeopardize the continued existence of any
endangered or threatened species or adversely
affect its critical habitat.

Similar Virginia requirements for submittal and
review of environmental assessments.
Potentially affected endangered
species have not been identified.
The remedial action will be
implemented so resources are not
adversely affected should any be
identified in the future.
Regulations for the
Enforcement of the
Endangered Plant
and Insect Species
Act
2 VAC 5-310-10
Applicable
The Archaeological
and Historical
Preservation Act of
1974
Virginia Natural Area
Preserves Act
16 U.S.C ° 469
Applicable
                          10.1-209 to 217
                      To Be
                      Considered
Requires actions to avoid potential loss or
destruction of significant scientific, historical, or
archaeological data
                     Allows for preservation of certain significant
                     ecological systems.
Site is not known to be within a
historically significant area. If
future resources are identified
actions will be taken to ensure
compliance.
                                                         If specific species are found
                                                         actions will be taken to eliminate
                                                         or minimize degradation to these
                                                         resources.
Migratory Bird Area
16 USC Section 703
Applicable
Protects almost all species of native birds in the
U.S. from, unregulated "take" which can include
poisoning of hazardous waste sites.
Remedy will be implemented to
ensure that wastes have no
impacts to native birds.

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                                                  APPENDIX C
   ARAR or TBC

Chesapeake Bay
Preservation Area

Designation and

Management

Regulations


Virginia Hazardous

Waste Management

Regulations
Virginia Water
Protection Permit
Regulation
Executive Order
1190, Protection of
Wetlands

Clean Water Act
                             APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
                                          SITE 17:1400 AREA LANDFILL
                                          NSWCDL, DAHLGREN, VIRGINIA
   Regulation

9 VAC 10-20-10 to
280
9 VAC 20-60-10 to

1480
9 VAC 25-210-10 to
260
40 C.F.R 6,
Appendix A
  Classification

Relevant and
Appropriate
Applicable
Applicable
Applicable
            Requirement Synopsis

Requires certain locally designated tidal and
non-tidal wetlands and other sensitive areas be

subject to limitations, regarding land-disturbing

activities, removal of vegetation, use of

impervious cover, erosion and sediment
control, and stormwater management.

Applies to treatment storage, or disposal of

hazardous waste.
Facility or activity design must adequately
address the issues arising from locating
facilities in wetlands and delineated wellhead
protection areas  (determined vulnerable.)
Action to minimize the destruction, loss, or
degradation of wetlands.
   Applicability to Remedial
           Alternatives

Remedy implementation will
require construction activities.

Actions will address the regulatory

requirements.
During remedy implementation, if

any hazardous wastes are

generated, the hazardous waste

will be managed consistent with

Federal and Virginia requirements.

Site contains a marsh area
containing wetlands. The Remedy
will minimize impacts to wetland
areas and will restore the wetland
areas after remedy
implementation.

Site contains a marsh area
containing wetlands. The Remedy
will minimize impacts to wetland
areas and will restore the wetland
areas after remedy

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 (CWA) of 1972
Section 404
                        33 U.S.C °°1344
                      Applicable
                                                                              implementation.
Virginia Wetlands
Policy
4 VAC-25-380-10 to
40
Applicable
   ARAR or TBC

Procedures for
Implementing the
Reguirements of the
Council on
Environmental
Quality on the
National
Environmental Policy
Act.
    Regulation

40 C.F.R. Part 6
Appendix A
 Classification

Appplicable
           Reguirement Synopsis

EPA's policy for carrying out the provisions of
Executive Order 11990 (Protection of
Wetlands).  No activity that adversely affects a
wetland shall be permitted.
   Applicability to Remedial
          Alternatives

Site contains a marsh area
containing wetlands. The Remedy
will mimimize impacts to wetland
areas and will restore the wetland
areas after remedy
implementation.
II ACTION SPECIFIC
Capping /Closure
and Post Closure for
Muncipal Solid Waste
Landfills
Virginia Solid Waste
Management
Regulations

Military Munitions
Rules
40 CFR 258.60-61
Applicable
9 VAC 20-80-10 to
790
Applicable
 (40 CFR 260-266 and   To be
270)                  Considered
Reguirements for final cover systems to
minimize infiltration and erosion. Reguirements
for at least a 10 year post closure care period
including maintaining integrity and effectiveness
of the final cover and maintenance of
groundwater monitoring.
                     Recently promulgated regulations in response
                     to Section 107 of the Federal Facilities
                     Compliance Act of 1992, identifying when
                     conventional and chemical military munitions
                     become hazardous waste. Applications of the
                     rules are a 'TBC' until adopted by states
                     authorized to administer RCRA.
Installation of a Virginia Sanitary
Landfill Cap reguires adherence to
these regulations or eguivalent
performance standards at Site 17
                                                         Ordnance-related wastes
                                                         potentially buried at Site 17 will be
                                                         managed in compliance with the
                                                         rules.

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                                                APPENDIX C
   ARAR or TBC
                             APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
                                          SITE 17:1400 AREA LANDFILL
                                          NSWCDL, DAHLGREN, VIRGINIA
    Regulation
                                                Classification
                              Requirement Synopsis
                                                            Applicability to Remedial
                                                                  Alternatives
DoD Guidance on
Property
Contaminated with
Ammunition,
Explosives or
Chemical Agents
Erosion and
Sediment Control
DoD 6055.9-STD
                      To Be
                      Considered
Virginia Solid Waste
Management
Regulations
VR 625-02-00
4 VAC 50-30-10
Applicable
9 VAC 20-80- 250


9 VAC 20-80-210

9 VAC 20-80-310
Applicable


Applicable

Applicable
Dod guidance document stipulating policy and
procedure to provide protection of personnel
resulting from DoD ammunition, explosives or
chemical agent contamination. Includes
property currently or formerly owned, leased or
used by DoD, and calls for identification and
control at active installations, and provides
guidance for potential land disposal.

Erosion and sediment control plans are to be
submitted for land-disturbing activities, and be
in compliance with the locality and/or local soil
and water conservation district.
Permanent Closure Criteria governing: Access
Restriction, Closure and Post Closure Care,
Gas Management, Drainage Layer, Final
Cover, Run-on Run-off controls, Site
Monitoring, Control of Groundwater Intrusion,
Groundwater Corrective Action and compliance
with other permanent closure requirements.
                                                                              Capping of Site 17 will be
                                                                              completed to be consistent with
                                                                              DoD policy and procedures to
                                                                              address safety issues.
Construction activities will disturb
the land in the vicinity of the site.
Activities will address Virginia
erosion and sediment control
requirements.

Virginia solid Waste Management
requirements need to be
addressed with the installation of
the cap at Site 17. Equivalent
performance standards will meet
Final Cover requirements.
AIR

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                                                  APPENDIX C
                             APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
                                         SITE 17: 11400 AREA LANDFILL
                                          NSWCDL, DAHLGREN, VIRGINIA
   ARAR or TBC
    Regulation
Visible and Fugitive    9 VAC 5-30-20
Dust Emissions

                        9 VAC 5-30-60
                        Classification              Reguirement Synopsis

                      Applicable           Control of Particulate Matter (TSP)
                      Applicable
                                           Control of Particulate Matter (PM10)
                                                            Applicability to Remedial
                                                                  Alternatives

                                                         Visible and Fugitive Dust
                                                         emissions from remedial actions
                                                         shall be controlled, as necessary.
Standards of
Performance for
Toxic Pollutants
WATER
9 VAC 5-50-60 to 120  Applicable


                      Applicable
9 VAC 5-50-160 to
230
Standards for visible and/or fugitive dust
emissions.

Standards of performance for toxic pollutants.
Toxic pollutants are not expected
during remedial actions; however,
corrective action will be performed
if problems arise.
Criteria for            49 C.F.R. 257.3-3(a)  Potentially
Classification of Solid                       Applicable
Waste Disposal          33 U.S.C. °° 1342
Facilities and
Practices
Criteria for            49 C.F.R. 257.3-3(a)  Applicable
Classification of Solid
Waste Disposal          33 U.S.C. °° 1288
Facilities and
Practices
                                           A facility shall not cause a discharge of
                                           pollutants into the waters of the U.S. that is in
                                           violation of the substantive reguirements of the
                                           NPDES under CWA Section 402, as amended.
                                           A facility or practice shall not cause nonpoint
                                           source pollution of the waters of the U.  S.  that
                                           violates applicable legal substantive
                                           reguirements implementing an areawide or
                                           Statewide water guality management plan
                                           approved by the Administrator under CWA
                                           Section 208, as amended.
                                                                                                    No discharges under the remedy
                                                                                                    are planned. In addition,  NPDES
                                                                                                    program is delegated to Virginia
                                                                                                    (VPDES).  Potentially applicable
                                                                                                    for situations potentially not
                                                                                                    covered by VPDES.

                                                                                                    Potential future releases to
                                                                                                    groundwater could migrate to
                                                                                                    nearby tributaries or an adjacent
                                                                                                    pond.  Natural vegetation,  hybrid
                                                                                                    poplars and evergreens will
                                                                                                    reduce infiltration and
                                                                                                    groundwater discharge. Ongoing
                                                                                                    monitoring will monitor
                                                                                                                            effectiveness.

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                                                     APPENDIX C

                                APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
                                              SITE 17:1400 AREA LANDFILL
                                              NSWCDL, DAHLGREN, VIRGINIA
   ARAR or TBC

Criteria for
Classification of Solid
Waste Disposal
Facilities and
Practices
    Regulation

49 C.F.R. 257.3-4 and
Appendix I
                                                    Classification
Applicable
           Requirement Synopsis

A facility or practice shall not contaminate an
underground drinking water source beyond the
solid waste boundary or a court- or State-
established alternative.
                    Applicability to Remedial
           Alternatives

Potential future releases to
groundwater could contaminate
groundwater over risk-based
criteria. Ongoing monitoring will
address the requirement.
Clean Water Act
Water Quality &
Groundwater
Standards

Surface Water
Standards
                          33 U.S.C. 1251 et
                          seq.
9 VAC 25-260-190 to
240

9 VAC 25-260-5 to
150, 160-170, 310
                         Relevant and
                         Appropriate
Relevant and
Appropriate

Relevant and
Appropriate
                  Criteria and standards for groundwater quality.
                  Virginia regulation provides basis for risk-based
                  remediation and discharge limitations.
Standards and criteria for State waters,
including wetlands.
                                                         Provides basis for risk-based
                                                         decision making, establishes
                                                        standards for groundwater quality.
                                                         Ongoing monitoring at Site 17 will
                                                         address the requirement.
Provides standards for evaluating
State waters and wetlands at Site
17.
Virginia Pollution
Discharge
Elimination System
(VPDES)
Virginia Pollution
Abatement  (VPA)
Permit Regulation

Virginia Solid Waste
Management
Regulations
9 VAC 25-31-10 to
940
Applicable
9 VAC 25-32-10 to
300
9 VAC 20-80-250  (D)
Applicable
Applicable
Procedures and requirements for discharging
pollutants into surface waters, or any activity
which impacts physical, chemical or biological
properties of surface waters.
Groundwater Monitoring Design Standards.
Capping of Site 17 is not expected
to produce waste liquids that
would be discharged to surface
waters. Any future activities or
groundwater monitoring (e.g.
generation of purge water)  will
address regulatory requirements.
Completion of additional soil
borings, monitoring wells and
subsurface investigations will be
consistent with regulatory

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                                                                                                                              requirements.
                                                     APPENDIX C

                                APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
                                              SITE 17:1400 AREA LANDFILL
                                              NSWCDL, DAHLGREN, VIRGINIA
   ARAR or TBC

Stormwater
Management
Regulations
    Regulation

4 VAC 3-20-10 to 251
 Classification              Requirement Synopsis

Applicable        Criteria for stormwater management.
      Applicability to Remedial
            Alternatives

Design of Site 17 cap will include
applicable stormwater
management requirements.

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