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4.0 SITE HISTORY AND INVESTIGATION FINDINGS
• ' for these four AREEs was conducted to evaluate the nature and extent of contamination
associated with past site activities. Environmental samples collected and analyzed during the Rl were used in
conjunction with the results from the SI to assess the condition of each of the AREEs The environmental
media investigated included surface soil (0 to 2 ft below ground surface [bgs]), subsurface soil (2 ft to
approximately 10 ft bgs), surface water, sediment, and groundwater. Analytical results were compared to
background concentrations and regulatory screening levels to determine if environmental media had been
adverse y impacted by site activities. A brief description of each of the four AREEs and the significant findings
of the Rl and SI are presented in the following paragraphs. A detailed presentation of the samples collected
and the analytical results can be found in the Phase II Reuse Area Rl Report (USAGE, 1999) available in the
Information Repository.
4.1 AREE 2 - Sewage Treatment Plant
n/LJcr 2 is fte Sewa9e treatment plant (STP) which serves permanent residents and daily employees
f wuco been in Service Since 195Z The plant has treated sanitary wastewater, industrial wastewater
from VHFS operations (photographic, painting, laboratory, vehicle washing, and metal etching), and surface
water runoff. The facility discharges treated effluent to South Run under a Virginia Pollutant Discharae
Elimination System (VPDES) permit. Before 1980, sludge was stored in piles on the ground near South Run.
ADCC Surface soil, subsurface soil, sediment, surface water, and groundwater samples were collected at
AKEE 2 as shown on Figure 3. Metals were detected in surface soil above residential soil risk-based
concentrations (RBCs) established by U.S. Environmental Protection Agency (USEPA) Region III for screenina
analytical results. Mercury (maximum concentration of 4.3 parts per million [ppm]) was detected above the
residential soil RBC of 0.78 ppm in surface soil samples SS-02-001. and SS-02-002 Benzo(a)pyrene a
polynuclear aromatic hydrocarbon (PAH), was present above residential soil RBCs in one surface soil sample
downgradient of the former sludge pile. Based on the results of the subsurface soil samples subsurface soil
has not been impacted by AREE 2 activities. '
4.2 AREE 4 - Auto Craft Shop
The Auto Craft Shop (Buildings 306 and 308) was used as the motor pool from 1943 to 1 967 and as
a0Voo!C le ™aintenance area where military personnel performed maintenance on their private vehicles from
1 968 to 1 994. The buildings were used to store oil, solvents, and lubricants for vehicle maintenance activities
as well as spent solvent and waste oil filters. The buildings have concrete floors with no curbs or floor drains
Gasoline and oil spills have been recorded in this area and were cleaned up using absorbents A 1 000-gallon
UST was used to store waste oil prior to its removal in July, 1990. A plume of petroleum contamination
currently lies under the shop as a result of leaks from the UST. A corrective action for this plume has been
implemented. Three areas where surface runoff/discharge from AREE 4 occurs have been identified (see
Figure 4). An outdoor vehicle wash rack near Building 308 drained into a grit chamber which has been
removed. The grit chamber was used to settle the solids prior to discharge of water from the vehicle wash rack
via a ceramic pipe into the wooded area south of Building 308. The floor of the grit chamber and the associated
contaminated soil were removed during the Phase II reuse area Rl field investigation. A storm sewer drain
located west of Buildings 306 and 308 discharged surface runoff to the field south of the Auto Craft Shop
Surface runoff also drains south of the Auto Craft Shop near the former hydraulic lift.
Surface soil, subsurface soil, and groundwater samples were collected at AREE 4 as shown on Figure
4. Surface and subsurface soil results are presented herein; groundwater results are presented in a separate
Decision Document (DD) which addresses site-wide groundwater. TPH contamination, exceeding the Virginia
TPH soil action level for USTs of 100 ppm, was present in surface soil samples collected near the storm sewer
discharge area, former hydraulic lift surface runoff area, and wash rack discharge area. The maximum TPH
concentration (1 ,860 ppm) was detected in surface soil sample SS-04-002 collected at the former hydraulic
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UNNAMED TRIBUTARY
TO SOUTH RUN
RISW2-2
RISED2-2
SEWACE TREATMENT
PLANT
GROUNOWATER
ROW \
OIRECTON \
SOIL LOCATIONS
(RISS2HANO RISS2-2) ARE
CO-LOCATH! WITH THE SOIL
BORING LOtXnSJjS (RJSB2-1
AND RISS2-2).
2. MONITORING WELL NUMBERS
2MW-1 THROUGH 2MW-3 HAVE
SEEN MODIFIED FROM THE
NUMBERS REPORTED IN THE
ORIGINAL HELD INVESTIGATIONS
IN ORDER TO PROVIDE UNIQUE
WELL NUMBERS FOR THIS
REPORT.
..IMPACTED SURFACE SOIL AREA
(APPROXIMATE)
.BUILDING
.VHFS BOUNDARY
.PAVED ROAD
.FENCE
..STREAM
..TRIBUTARY
.TOPOGRAPHIC CONTOUR (FT MSL)
.SI SURFACE SOIL SAMPLE LOCATION
.EXISTING MONITORING WELL
.PHASE II Rl MONITORING WELL
O PHASE II Rl SOIL 30RING LOCATION
P..PHASE II Rl SURFACE WATER/SEDIMENT SAMPLE LOCATION
RGURE 3
Sf AND Rl SAMPLE LOCATIONS
FOR AREE 2-SEWAGE
TREATMENT PLANT
-------
SS-04-00
R1SB+-1
RE84-6
RE84-7
SS-04-
FCRMER GRIT
CHAMBER
GROUNOWATER ^
ROW DIRECTION
(BASED ON AREE 4 WELLS)
RE84-
SS-04-003
RISB4-
NOTES:
1. SURFACE SOIL SAMPLE LOCATIONS (RISS4-3 THROUGH
RBS4-11) ARE CO-LOCATED WITH THE SOIL BORING
LOCATIONS (RISB«-J THROUGH RES4-I1).
2. UONTORING waL NUMBERS 4UW-1 THROUGH 4MW-J
HAVE BEEN UODIREO FROU THE NUMBERS REPORTED
THE ORIGINAL FIELD INVESTIGATIONS IN ORDEH TO
PROVIDE UNIQUE WELL NUMBERS FOR THIS REPORT.
APPROXIMATE AREA
OF EXCAVATION
LEGEND:
IMPACTED SURFACE SOIL AREA
(APPROXIMATE)
-x—x- FENCE
•• BUILDING
===== ., ROAD
""= STORM DRAIN
,--4IO^__ TOPOGRAPHIC CONTOUR (FT MSL)
Q SI SOIL SORING LOCATION
• SI SURFACE SOIL SAMPLE LOCATION
O PHASE II Rl SOIL BORING LOCATION
®. EXISTING MONITORING WELL
•$: PHASE II Rl MONfTORING WELL
SCALE IN FEET
FIGURE 4
SI AND Rl SAMPLE LOCATIONS
FOR AREE 4 -
AUTO CRAFT SHOP
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lift surface runoff area. Metals were detected in surface soil above residential soil RBCs at all three surface
runoff/discharge areas. Lead contamination exceeding the USEPA screening level for lead in residential soil
of 400 ppm was detected in surface soil at all three surface runoff/discharge areas. The maximum lead
concentration (1,700 ppm) was detected in a surface soil sample collected from the storm sewer discharoe
area. Four PAHs (benzo[a]anthracene, benzofajpyrene, benzo[b]fluoranthene, and indenofl 2 3-cd]Dvrenei
exceeding the residential soil RBCs are present in surface soil at the wash rack discharge area Onlv
benzo(a)pyrene is present in surface soil above the residential soil RBC (0.087 ppm) in all three surface
runoff/discharge areas. The maximum benzo(a)pyrene concentration of 1.52 ppm was detected in surface soil
sample RISS4-5 located in the wash rack discharge area. Based on the results of the subsurface soil samples
from the three surface runoff/discharge areas, contaminant concentrations in subsurface soil were all below
screening levels.
4.3 AREE 28-5 - Former Service Station Abandoned USTs
t
AREE 28-5 consists of the Former Service Station Abandoned USTs located under the asphalt parking
lot approximately 60 ft northwest of the former service station (Building 220). Three 5,000-gallon steel USTs
were used for the storage of gasoline and diesel fuel products. The USTs were approximately 30 years old and
were in service until 1983. Environmental Restoration Company (ERG) removed the USTs and associated
pipelines in December, 1994.
Subsurface soil and groundwater samples were collected at AREE 28-5 as shown on Figure 5 TPH
contamination, exceeding the Virginia TPH soil action level for USTs of 100 ppm, was detected in subsurface
soil in the vicinity of the former pump island at depths ranging from 2 ft bgs to at least 10 ft bgs The maximum
TPH concentration (5,273 ppm) was detected at a depth of'8-10 ft bgs in soil boring RISB28-5-1.
4.4 AREE 31 - Construction Debris Pile #1
AREE ai is a construction debris pile located approximately 200 to 300 ft northwest of the
southernmost tip of the VHFS property boundary in a predominantly wooded and vegetated area The pile
consists of construction debris including, but not limited to, concrete pipe, corrugated steel pipe steel footers
antennae pillars, roofing paper, bricks, cinder blocks, cement slabs, and insulation material The debris pile
has an area of approximately 15 ft by 150 ft.
Surface and subsurface (from a test pit) soil samples were collected at AREE 31 as shown on Figure
6. Metals (copper and lead) and PAH contamination is present in surface soil sample RISS31-2. The lead
concentration of 3,610 ppm exceeded the USEPA screening level for lead in residential soil of 400 ppm
Copper at 1,880 ppm exceeded its residential soil RBC of 310 ppm. Five PAHs (benzofajanthracene
benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, and indenofl ,2,3-cd]pyrene) exceeded the
residential soil RBCs by one or more orders of magnitude in surface soil sample RISS31-2. For example
benzo(a)pyrene was detected at 34.6 ppm compared to its residential soil RBC of 0.087 ppm. Subsurface soil
has not been impacted by the debris present at AREE 31.
5.0 SUMMARY OF SITE RISKS
A BRA was conducted as part of the Rl to assess the human health and ecological problems that could
result if the contamination at the AREEs was not remediated. The Human Health Risk Assessment (HHRA)
was prepared to evaluate the magnitude of potential adverse effects on human health associated with current
industrial/commercial and potential future residential exposures to site-related chemicals at the AREEs. The
Ecological Risk Assessment (ERA) was conducted to characterize the potential threats to ecological receptors
posed by contaminants at the AREEs.
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GEOPHYSICAL AND
SOIL ORGANIC VAPOR
SURVEY AREA
ASSUMED
GROUNDWATER
FLOW DIRECTION
1
LEGEND:
ESSJIMPACTED SOIL.AREA (APPROXIMATE)
^m BUILDING
' PAVED ROAD
-*10^..TOPOGRAPHIC CONTOUR (R MSL)
•36 UST na PIPE
• I i. .FORMER UST LOCATION
© SI SOIL BORING LOCATION
•$- PHASE II Rl MONITORING WELL
O....PHASE II Rl SOIL BORING LOCATION
10
20
SCALE IN FEET
FIGURE 5
SI AND Rl SAMPLE LOCATIONS
FOR AREE 28-5 - FORMER
SERVICE STATION USTs
-------
APPROXIMATE LOCATION
OF CONSTRUCTION
DEBRIS PILE #1
IMPACTED SURFACE SOIL AREA
(APPROXIMATE)
VHFS BOUNDARY
PAVED ROAD
•x— x — x- ................................. FENCE
--- 420 --- ......... TOPOGRAPHIC CCJffOUR (FT MSL)
........ PHASE I! Rl TEST PIT LOCATION
......... PHASE II R! TEST PtT SAMPLE
.PHASE
Ri SURFACE SOIL
SAMPLE LOCATION
SCALE IN FEET
FIGURE 6
Rl SAMPLE LOCATIONS
FOR AREE 31 - CONSTRUCTION
DEBRIS PILE #1
10
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The HHRA follows a four-step process:
• Selection of Chemicals of Potential Concern - identifies the contaminants of potential concern
based on their toxicity, frequency of occurrence, and concentration by comparing the maximum
concentrations of detected chemicals with RBCs which are health-protective chemical
concentrations that are back-calculated using toxicity criteria, a 1x10"6 target carcinogenic risk or
a 0.1 hazard quotient (HQ, defined below), and conservative exposure parameters;
• Exposure Assessment - identifies the potential pathways of exposure, and estimates the
concentrations of contaminants to which people may be exposed as well as the frequency and
duration of these exposures;
• Toxicitv Assessment - determines the toxic effects of the contaminants; and
• Risk Characterization - provides a quantitative assessment of the overall current and future risk
to people from site contaminants based on the exposure and toxicity information.
The HHRA evaluated health effects which could result from exposure to soil, groundwater surface
water, and sediment contamination in the Phase II reuse area of VHFS. The HHRA evaluated potential risks
to current workers who could be exposed to contaminants in surface soil, and to current trespassers who could
be exposed to contamination in surface soil, surface water, and sediment. In addition, the HHRA evaluated
potential risks to hypothetical future adult residents who could be exposed to contaminants in groundwater and
surface soil and to hypothetical future child residents who could be exposed to contaminants in groundwater
surface soil, surface water, and sediment. Potential risks to future excavation workers who could be exposed
to contaminants in subsurface soil were also evaluated in the HHRA. Subsurface soil was only evaluated for
excavation workers and not residents since residents would be unlikely to be exposed to subsurface soil In
addition, the concentrations of contaminants currently present in subsurface soil would not be representative
of the concentrations that might be present if landscaping activities were to occur which would involve mixing
of subsurface soils-with surface soil, clean topsoil, and other soil amendments. Therefore it would not be
appropriate to evaluate risks to residents using available subsurface soil data.
Potential carcinogenic (cancer-related) effects and noncarcinogenic effects (including various impacts
on different organ systems, such as lungs, liver, etc.) were evaluated in the HHRA. Carcinogenic effects are
expressed as the probability that an individual will develop cancer from exposure to the contaminants from each
AREE. The evaluation of noncarcinogenic effects is based on the hazard index (HI), which is the summation
of the HQs for individual chemicals. The HQ is a comparison of chemical-specific chronic exposure doses with
the corresponding protective doses derived from health criteria. The USEPA recommends that remedial
actions may be warranted at sites where the carcinogenic risk to any person is greater than 1 x10"4 or the HI is
greater than 1. A carcinogenic risk of 1x10"4 means that there is a potential of one additional person in a
population of 10,000 developing cancer from exposure to contaminants at an AREE if the AREE is not
remediated. A HI greater than 1 indicates a potential for noncarcinogenic health effects if the AREE is not
remediated.
The ERA also, follows a four-step process:
• Problem Formulation - develops information that characterizes habitats and potentially exposed
species and identifies contaminants of concern, exposure pathways, and receptors;
• Exposure Assessment - estimates exposure point concentrations for selected indicator species;
• Ecotoxicologic Effects Assessment - identifies concentrations or doses of contaminants that are
protective of indicator species; and
11
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• Risk Characterization - estimates potential adverse effects from exposure to contaminant-;
on exposure and toxicity information.
The ERA evaluated ecological effects which could result from exposure to surface soil surface watPr
and sediment contamination in the Phase II reuse area of VHFS. The ERA evaluated potential adverse'
ecological effects to terrestrial plants and terrestrial invertebrates (represented by earthworms) exposed to
contaminants in surface soil. In addition, potential adverse ecological effects to mammals (represented bv
shrews) and birds (represented by robins) through bioaccumulation in the food web and exposure to
contaminants in surface soil were evaluated. Potential adverse ecological effects to aquatic life from exposure
to contaminants in surface water and sediment were also evaluated in the ERA. Further the potential adverse
ecological effects to mammals (represented by minks) and birds (represented 'by herons) through
bioaccumulation in the food web and exposure to contaminants in sediment were evaluated.
The evaluation of significant potential adverse ecological effects is based on the Environmental Effects
Quotient (EEQ). The EEQ is the ratio of the estimated exposure concentrations/doses for the chemicals of
potential concern and the toxicity reference values (TRVs) for the ecological receptors. If the EEQ is greater
than 1, there is a potential for adverse ecological effects to occur. As the magnitude of the EEQ becomes
greater than 1, the potential for adverse ecological effects becomes more significant.
The results of the BRA for the four AREEs are presented in the following paragraphs A detailed
presentation of the BRA can be found in the Phase II Reuse Area Rl Report (USAGE 1999) available in the
information Repository.
5.1 AREE 2 - Sewage Treatment Plant
The HHRA determined that, under both current industrial/commercial and potential future residential
land-use conditions, the risks to workers, trespassers, residents, and excavation workers are acceptable for
exposure to site-related contaminants at AREE 2. Discounting naturally-occurring metals that were statistically
determined to be within background concentrations, the highest estimated upper-bound excess lifetime cancer
risk (1X10'3) is for child residents exposed to site-related contaminants'in surface soil by incidental ingestion
and the highest noncarcinogenic risk (Hl=5) is for child residents exposed to site-related contaminants in
surface soil by incidental ingestion. The contaminant that drove the elevated HI at AREE 2 is iron which was
detected at comparable levels in similar surface soil types in background locations and is therefore not site-
related.
The ERA determined that contaminants in surface soil at AREE 2 pose significant potential adverse
ecological effects. The significant potential adverse ecological effects result primarily from mercury. Mercury
results in significant potential adverse ecological effects for terrestrial plants, earthworms, robins, and shrews
with the greatest potential adverse ecological effects occurring to robins (EEQ of 3,500).
The mercury contamination downgradient of the former sludge pile is recommended for remediation.
The impacted area has approximate dimensions of 75 ft by 25 ft by 2 ft deep, as shown on Figure 3.
5.2 AREE 4 - Auto Craft Shop
The HHRA concluded that, under both current industrial/commercial and potential future residential
land-use conditions, the risks to workers, trespassers, residents, and excavation workers are acceptable for
exposure to site-related contaminants, except for lead, in soil at AREE 4. Discounting naturally-occurring
metals that were statistically determined to be within background concentrations, the highest estimated upper-
bound excess lifetime cancer risk (3X10'5) is for child residents exposed to site-related contaminants in surface
soil by incidental ingestion, and the highest noncarcinogenic risk (HN0.5) is for child residents exposed to site-
related contaminants in surface soil by dermal absorption.
12
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The human health risks associated with exposure to lead contamination in surface s
e,rsinH9 the integrfed Exposure uptake Biokinefc M°dei i^s^n
evaluating lead exposures for young children in residential settings. The IEUBK Model calculates
levels which result from exposures to lead which may then be compared to blood °ead te^^
significance for purposes of risk evaluation. The IEUBK Model run for AREE 4 predated a geomeric ,
? 10 o dL? TH HK P nta' C0n°%n W6re identified in subsurface so" ^ AREE 28-5 in the HHRA. However risS
associated with exposures to TPH could not be assessed in the BRA because this analyticalVarametel
represents a mixture of chemical constituents. Since TPH measurements give no in Jcaton oHhe cheS
constrtuents present or their respective concentrations, they cannot be used to pfJSS^^SToSSlSte
Dumo SandTARFF?«n;0t ^ ?*£*?' ™ Contamination in subsurfa<* «« 'n the vicinity of thefo mer
forTpm^? / ?h f ? 6dS the Virg'nia TPH S0il action ievel for USTs and fe- therefore/recommended
for remediaton. The ,mPacted area is approximately 20 ft x 20 ft x 1 0 ft deep (minimum), as shown on Figure
5.4 AREE 31 - Construction Debris Pile #1
^ri,QroIh^ ?HRA determined that. under current industrial/commercial land-use conditions, the risks to
workers and trespassers are acceptable for exposure to contaminants in surface soil at AREE 31 Under
potential future residential land-use conditions, assuming that AREE 31 is not remediated, the risks to potential
adult and child residents are unacceptable for exposure to contaminants in surface soil at AREE 31 The
highest estimated upper-bound excess lifetime cancer risk is for child residents exposed to contaminants in
surface soil by mcidental ingestion; this risk is 4x1 rj4 (i.e., 4 in 1 0,000 residents may develop cancer cTused by
exposure to contam.nants in surface soil at AREE 31). Cancer risks were due primarily to exposures to
benzo(a)pyrene and other PAHs. Discounting naturally-occurring metals that were statistically determined to
be within background concentrations, the highest noncarcinogenic risk is for child residents exposed to
contaminants in surface soil by incidental ingestion; the HI is estimated to be 0.7.
As explained in the AREE 4 discussion, lead contamination in surface soil at AREE 31 was evaluated
using the IEUBK Model which predicted a geometric mean blood lead level of 15 ^g/dL, with 78 4 percent of
the population exceeding the blood lead level of concern (10 ng/dL). Again, the USEPA currently finds 5
percent of the population exceeding the blood lead level of concern acceptable. Therefore the IEUBK Model
13
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results indicate that if AREE 31 was developed for residential use in the future, the lead concentrations in the
surface soil may be a potential problem for young children.
The ERA determined that contaminants in surface soil at AREE 31 pose significant potential adverse
ecological effects. The significant potential adverse ecological effects result primarily from metals (copper
lead, mercury, and selenium) and one PAH (benzo[a]pyrene). Mercury results in significant potential adverse
ecological effects for robins and shrews, with the greatest potential adverse ecological effects occurring to
robins (EEQ of 250). Copper results in significant potential adverse ecological effects for terrestrial plants and
earthworms, with the greatest potential adverse ecological effects occurring to earthworms (EEQ of 38)
Selenium and lead result in significant potential adverse ecological effects for terrestrial plants with EEQs of
25 and 72, respectively. Benzo(a)pyrene results in significant potential adverse effects to earthworms with an
EEQ of 13.
The most significant contamination at AREE 31 is in surface soil in the vicinity of surface soil sample
RISS31-2 located in the northeastern portion of the debris pile, which is recommended for remediation The
impacted area has approximate dimensions of 50 ft x 15 ft x 2 ft, as shown on Figure 6.
6.0 REMEDIAL ACTION OBJECTIVES
Remedial action objectives are specific goals to protect human health and the environment The
remedial action objective for the four AREEs is to minimize the potential for contaminated soil to pose
unacceptable risks to human or ecological receptors.
7.0 CLEANUP LEVELS ESTABLISHED FOR THE SELECTED ALTERNATIVE
USEPA has established soil cleanup levels for the contaminants that contribute to the unacceptable
risk determination at each of the four AREEs. The soil cleanup levels are presented in Table 1 The soil
cleanup level for AREE 2 is based on concentrations which are protective of ecological receptors (EEQ=10)
The soil cleanup level for lead in surface soil at AREEs 4 and 31 is based on the USEPA screening level for
lead in residential soil of 400 ppm. The soil cleanup levels for other metals at AREE 4 are based on
concentrations which are protective of ecological receptors. The soil cleanup level for AREE 28-5 is based on
A^L9,inia TPH S0il acti°n levl' for USTs Of10° ppm' USEPA established the soil cleanup levels for PAHs
at AREE 31 based on a 1X10 (one in 1,000,000 people) upper-bound excess lifetime cancer risk for the
potential future residential use scenario. The soil cleanup levels for metals, other than lead at AREE 31 are
based on concentrations which are protective of ecological receptors.
8.0 SUMMARY OF REMEDIAL ALTERNATIVES
Two remedial alternatives were evaluated to address soil contamination at AREEs 2, 4 28-5 and 31
The range of remedial alternatives considered was limited by the nature and extent of the contamination Since
the amount of soil requiring remediation is relatively small (approximately 400 cubic yards), it was not practical
to consider active treatment or containment options in terms of cost-effectiveness and implementability The
following remedial alternatives were evaluated:
• Alternative 1 - No Action; and
• Alternative 2 - Soil Removal.
14
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Table 1
Cleanup Levels Established for Soil at the Four AREEs
Constituents
Mercury (Ecological risk)
AREE 2 - SEWAGE TREATMENT PLANT
Lead (Human Health & Ecological risk)
Mercury (Ecological risk)
AREE 4 - AUTO CRAFT SHOP
Selenium (Ecological risk)
Zinc (Ecological risk) fc)
TPH
AREE 28-S - FORMER SERVICE STATION ABANDONED USTs
100(e)
Benzo(a)anthracene (Human Health risk)
AREE 31 - CONSTRUCTION DEBRIS PILE #1
Benzo(a)pvrene (Human Health & Ecological risk)
Benzo(b)fluoranthene (Human Health risk)
Ben2o(k)fluoranthene (Human Health risk) fc)
Copper (Ecological risk)
Jndenod .2,3-cd)pvrene (Human Health risk)
Lead (Human Health & Ecological risk)
Mercury (Ecological risk)
(Ecological risk)
TPH - total petroleum hydrocarbons
USTs - underground storage tanks
(a) Based on a concentration which is protective of ecological receptors (EEOlO)
} ™T«n,hfef'th C'eaJ1Up. leVe'S are based on a 1X1° uPPer-b°und excess lifetime cancer risk for the
potental future residential land-use scenario.
(c) These compounds contribute to but do not drive unacceptable risk
(d) USEPA screening level for lead in residential soil.
(e) Virginia TPH soil action level for USTs.
15
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8.1 Alternative 1 - No Action
The National Oil and Hazardous Substances Pollution Contingency Plan (NCP) and Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA), as amended by the Superfund
Amendments and Reauthorization Act (SARA), require that a No Action alternative be considered as a baseline
for comparison to other alternatives. No action would be taken to address site contamination under this
alternative. In accordance with Section 121 of CERCLA, each AREE would be reviewed at least once every
five years to re-evaluate site conditions and to determine the need for remedial action to protect human health
and the environment.
8.2 Alternative 2 - Soil Removal
Under this alternative, all contaminated soil exceeding the established cleanup levels would be
excavated, transported off site by truck, and disposed using a combination of permitted off-site hazardous
waste, construction debris, and/or municipal landfills, as appropriate based on analytical results. Approximately
400 cubic yards of impacted soil would be excavated as part of this alternative, followed by confirmation
sampling to assure adequate removal of all soil exceeding the cleanup levels. Upon completion of the soil
excavation, disturbed areas would be backfilled, regraded, and either vegetatively stabilized or paved (AREE
28-5). The five-year review does not apply to this alternative because hazardous substances above risk-based
cleanup levels would not remain on site.
9.0 EVALUATION OF ALTERNATIVES
CERCLA requires a comparison of the alternatives using nine evaluation criteria: overall protection
of human health and the environment; compliance with applicable or relevant and appropriate requirements
(ARARs); long-term effectiveness and permanence; reduction of toxicity, mobility or volume through treatment;
short-term effectiveness; implementability; cost; and regulator and community acceptance. The first two criteria
are considered by USEPA to be threshold criteria which must be met by each alternative. The nine evaluation
criteria are described below:
• Overall protection of human health and the environment addresses whether or not a remedy
provides adequate protection and describes how risks posed through each pathway are
eliminated, reduced, or controlled through treatment, engineering controls, or institutional
controls.
• Compliance with ARARs addresses whether or not a remedy will meet all of the applicable
or relevant and appropriate requirements of other federal and state environmental statutes
and requirements or provides grounds for invoking a waiver.
• Long-term effectiveness and permanence refers to the ability of a remedy to maintain reliable
protection of human health overtime, once cleanup goals have been met.
• Reduction of toxicitv. mobility, or volume through treatment is the anticipated performance of
the treatment technologies a remedy may employ.
• Short-term effectiveness addresses the period of time needed to achieve protection and any
adverse impacts on human health and the environment that may be posed during the
construction and implementation period until cleanup goals are achieved.
• Implementsbilitv is the technical and administrative feasibility of a remedy, including the
availability of materials and services needed to implement a particular option.
16
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0* includes estimated capital and operation and maintenance costs, and net present worth
'^ a"emal*"is ""' """"a* based upon these evalua«on cmeria, and „
9.1 Overall Protection of Human Health and the Environment
onment
9.2 Compliance with ARARs
^
monitored during excavation activities to assure Taccepte Tbte air aualiS AL^ ^ C°ndltions would b«
monitoring, water sprays would be used to ^keep dus? level^ "^ aSed °n ^ ambient air
9.3 Long-term Effectiveness and Permanence
9.4 Reduction of Toxicity, Mobility, or Volume Through Treatment
9.5 Short-term Effectiveness
the short term because the volume of soil to be excavated
-" impacts to human health or the environment. Dust
17
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exposure to workers and adjacent residents would be controlled during excavation activities by water sprays
as needed. Prior to excavation operations, temporary erosion control structures would be installed to prevent
entry of storm water into the soil excavation areas and prevent erosion and movement of soil from contaminated
areas. Although truck traffic would be increased during implementation of Alternative 2 the implementation
period (approximately one month) is short and the number of trucks per day would be less than 20.
9.6 Implementability
Alternative 2 is considered readily implementable. Licensed transporters and permitted disposal
facilities are currently available. H
9.7 Cost
The cost to implement Alternative 2 is estimated at $260,000.
9.8 Regulator Acceptance
VDEQ and USEPA concur with the selected remedy.
9.9 Community Acceptance
A public meeting on the Proposed Plan was held on April 9,1998, in Warrenton, Virginia Comments
received dunng the public meeting and the public comment period are referenced in the Responsiveness
Summary (Section 12 of this DD).
10.0 SELECTED REMEDY AND STATUTORY DETERMINATIONS
10.1 Selected Remedy
Following review and consideration of the information in the Information Repository requirements of
CERCLA and the NCP, and the review of public comments on the Proposed Plan the U S Armv in
coordination with VDEQ and USEPA, has selected Alternative 2, Soil Removal, as the remedy for the
contaminated soil at AREEs 2, 4, 28-5, and 31.
Under this remedy, all contaminated soil exceeding the established cleanup levels would be excavated
transported off site by truck, and disposed using a combination of permitted off-site hazardous waste'
construction debris, and/or municipal landfills, as appropriate based on analytical results. Approximately 400
cuhc yards of impacted soil would be excavated as part of this remedy, followed by confirmation sampling to
assure adequate removal of all soil exceeding the cleanup levels (refer to Table 1). Upon completion of the
fAli!nCoVation' disturbed areas would be backfilled, regraded, and either vegetatively stabilized or paved
(AREE 28-5).
The estimated cost to implement this remedy is $260,000, and the on-site activities would require
approximately one month to complete.
10.2 Statutory Determinations
Under CERCLA Section 121, selected remedies must be protective of human health and the
environment, must comply with ARARs (unless a statutory waiver is justified), must be cost-effective, and must
utilize permanent solutions and alternative treatment technologies or resource recovery technologies to the
maximum extent practicable. In addition, CERCLA includes a preference for remedies that employ treatment
18
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that permanently and significantly reduces the volume, toxicity, dr mobility of hazardous waste as their principal
element. The following sections discuss the remedy in light of these statutory requirements.
10.2.1 Protection of Human Health and the Environment
The selected remedy would protect human health and the environment. All contaminated soil
exceeding the established cleanup levels will be removed and disposed of in permitted, off-site facilities. The
cleanup levels listed in Table 1 were developed to be protective of human health and the environment.
Short-term risks would be present as a result of dust exposure to workers and adjacent residents, soil
erosion and sedimentation during excavation activities, and transport of contaminated soil off site. These risks
would be acceptable as a result of control measures which would be implemented during the remedial action.
These control measures include use of water sprays during excavation operations to control dust, and use of
silt fences and other erosion control techniques to control erosion and soil movement from contaminated areas.
The increase in truck traffic would be minimal, with the addition of less than 20 trucks per day over the course
of approximately one month.
10.2.2 Compliance with ARARs
The selected remedy will be in full compliance with ARARs:
• 9 Virginia Administrative Code (VAC) 20-80-10 et seq.: Virginia Solid Waste Management Regulations
- the disposal of any soil, debris, sludge or any other solid waste must be done in compliance with the
regulations;
• 9 VAC 20-60-10 et sea.: Virginia Hazardous Waste Management Regulations - the disposal of any
hazardous waste must be done in compliance with the regulations;
• 4 VAC 50-30-10, et seq.: Virginia Erosion and Sedimentation Control Regulations - an erosion and
sedimentation control plan that complies with the minimum design and implementation standards of
the regulations will be prepared before engaging in any land disturbing activity;
• 9 VAC 5-10-10 through 9 VAC 5-80-350: Regulations of the Virginia Air Pollution Control Board -
ambient air monitoring will be used to determine the need for water sprays to control dust generation
in order to comply with ambient air quality standards for particulate matter.
10.2.3 Cost-Effectiveness
The selected remedy affords overall effectiveness proportional to its costs. All contaminated soil
exceeding the established cleanup levels will be removed from AREEs 2, 4,28-5, and 31. The entire remedy
will be achieved for approximately $260,000..
10.2.4 Utilization of Permanent Solutions and Alternative Treatment Technologies or
Resource Recovery Technologies to the Maximum Extent Practicable
The selected remedy utilizes permanent solutions to the maximum extent practicable while providing
the best balance among the other evaluation criteria. It achieves the best balance of tradeoffs with respect to
the primary balancing criteria of long-term effectiveness and permanence; reduction of toxicity, mobility, and
volume through treatment; short-term effectiveness; implementability; and cost; while also considering regulator
and community acceptance.
The selected remedy provides a high degree of long-term effectiveness and permanence as the
removal and off-site disposal of the contaminated soil would be permanent and irreversible. The variety of
contaminants present in the soil at AREEs 2, 4, 28-5, and 31 and the relatively small volume of contaminated
. soil cause on-site treatment technologies to be impracticable and not cost-effective. The selected remedy is
19
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easily implementable, with a relatively short time frame needed for design development. There is minimal risk
to the community during the implementation of the selected remedy, and the slight risks to the environment can
be reduced by implementing standard procedures, such as erosion and sedimentation controls.
10.2.5 Preference for Treatment as a Principal Element
Because treatment of the principal threat at AREEs 2,4,28-5, and 31 was not found to the practicable,
this remedy does not satisfy the statutory preference for treatment as a principal element of the remedy.
11.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
The Proposed Plan for AREEs 2, 4, 28-5, and 31 was released to the public on March 26, 1998 (see
Attachment 1). This document was made available for public review in the Information Repository at the
following location:
Fauquier County Library
Warrenton Branch - Reference Section
11 Winchester Street, Warrenton, VA
(540) 347-8750
Monday - Wednesday: 10:00 a.m. to 9:00 p.m.
Thursday - Saturday: 9:00 a.m. to 5:00 p.m.
Sunday: 1:00 p.m. to 5:00 p.m.
The notice of availability of the Proposed Plan (see Attachment 3) was published in The Fauauier
Citizen, the Fauauier Times-Democrat, and the Manassas Journal Messenger during the week of March 23,
1998. A public comment period was held from March 26,1998, through April 24,1998. In addition, a public
meeting was held on April 9,1998, to present the Proposed Plan for AREEs 2, 4,28-5, and 31 and to answer
questions and receive public comments. The public meeting minutes have been transcribed, and a copy of
the transcript is available to the public at the aforementioned location. A Responsiveness Summary, included
as part of this DD, has been prepared to respond to the significant comments, criticisms, and new relevant
information received during the comment period. Upon signing the DD, the U.S. Army will publish a notice of
availability of this DD in The Fauauier Citizen, the Fauquier Times-Democrat, and the Manassas Journal
Messenger, and place the DD in the Information Repository.
12.0 RESPONSIVENESS SUMMARY
The purpose of this Responsiveness Summary is to provide the public with a summary of citizen
comments, concerns, and questions about AREEs 2, 4, 28-5, and 31. A public meeting was held on April 9,
1998, to present the Proposed Plan and to answer questions and receive comments. At the public meeting,
one citizen had a question regarding the Proposed Plan. No written public comments were received during the
March 26,1998, through April 24,1998, comment period.
The Responsiveness Summary is divided into the following sections:
• Selected newspaper notices announcing dates of the public comment period and location and
time of the public meeting;
• Comments raised during the public meeting on April 9, 1998;
• Public meeting attendance roster; and
• Restoration Advisory Board Members.
20
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12.1 Selected Newspaper Notices
12.2 Comments Raised During the Public Meeting on April 9, 1998
" ***** ^^ The ^Z^S «™«™ and ** "• S- A-y's
CONCERNED CITIZEN: Is AREE 31 located directly under the trees or beyond the stand of trees?
ARMY RESPONSE: AREE 31 is located within the tree line.
12.3 Public Meeting Attendance Roster
«" 8*-.
12.4 Restoration Advisory Board Members
1 . Debra Reedy, Community Co-Chair
2. Richard Reisch, U.S. Army Co-Chair
3. Dean Eckelberry
4. John Mayhugh
5. Jeff Lippincott
6. Owen Bludau
7. Tim Tarr
8. NorrisGoff
9. Erich Meding
10. Kevin Bell
11. Mark Stevens
12. Nancy Inger
13. Joanne Smith
14. Henry Ross
15. Steve Mihalko
16. Robert Stroud
17. Steve Maddox
1 8. William Downey
19. GinaTyo
20. Joe Phelan
21. MikeMolloy
22. Denny Adams
23. JoeWiltse
24. Bob Root
25. Georgia Herbert
26. Robert Kube
27. Kim berly Davis
28. George Rosenberger
29. Adrienne Garreau
21
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30. Susan Dove
31. James Tucker
32. John Williams
13.0 REFERENCES
U.S. Army Corps of Engineers (USACE). 1999. Remedial Investigation Report. Vint Hill Farms Station Phase
II Reuse Area Remedial Investigation. Final Document. Prepared by ICF Kaiser Engineers, Inc.
Edgewood, Maryland. January, 1999.
U.S. Army Environmental Center (USAEC). 1996. Site inspection Report with Supplemental Hydrogeologic
Investigation. Vint Hill Farms Station. Warrenton, Virginia. Final Document. Prepared by Science
Applications International Corporation, McLean, Virginia. June, 1996.
22
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ATTACHMENT 1
PROPOSED PLAN
-------
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Proposed Plan
AREEs 2, 4, 28-5, and 31
Vint Hill Farms Station, Virginia
March 1998
INTRODUCTION
in
iS
°" site-related documents contained in the VHFS Information Repository The
y°" W"h 'mPOrtant Inf°rmafa1 3b°Ut ^ *e a"d 'he ** «^' £
Fauquier County Library
Warrenton Branch - Reference Section
1 1 Winchester Street, Warrenton, VA
(540)347-8750
Monday - Wednesday: 10:00 a.m. to 9:00 p.m.
Thursday - Saturday: 9:00 a.m. to 5:00 p.m.
Sunday: 1:00 p.m. to 5:00 p.m.
The US .Army needs your comments and suggestions. The U.S. Army, the U.S. Environmental Protection
Agency (USEPA) Region 111, and the Virginia Department of Environmental Quality (VD^S)uS^Se
pubte to revew and comment on both of the alternatives presented in the Proposed Plar^ ^ The public
on April 24, 199, P,eaSe send your
Kevin Bell, Public Affairs Officer
Public Affairs Office (Bldg..2500)
Vint Hiils Farm Station
Warrenton, VA 20187-5001
teAR& p S investi9aton and dea™P of contamination at the
selected AREEs at VHFS. Representatives from the U.S. Army will report on cleanuo alternative
cons,dered and the U.S. Army's preferred alternative. The meeting is scheduled for P alternat'Ves
Thursday, April 9, 1998 at 7:00 p.m.
Warrenton Middle School Auditorium
244 Waterloo Street, Warrenton, VA
Special provisions will be made for the handicapped and hearing impaired.
The remedy described in this Proposed Plan is the U.S. Army's preferred alternative for the selected AREEs
™™T I -I™37, Tdi1V the Preferred aKernative or select another remedial alternative if public
comments or additional data indicate that such a change will result in a more appropriate remedial action
The U.S. Army, in consultation with USEPA and VDEQ, will make a remedy selection for the AREEs in a
^rinn°^«mThent 3KSr the Pubiic,comment Period nas ended and the comments and information submitted
dunng that time have been reviewed and considered.
*ni , jf ui"S this Proposed Plan as part of its public participation responsibilities under Sections
and 117(3) of the Comprehensive Environmental Response, Compensation, and Liability Act
-------
(CERCLA). as amended, commonly known as the "Super-fund Program", and the National Environmental
Policy Act of 1969 (NEPA). This Proposed Plan focuses on AREEs 2, 4, 28-5, and 31. Other areas of VHFS
that the U.S. Army plans to remediate are addressed by separate Proposed Plans.
SITE BACKGROUND
VHFS is part of the U.S. Army Communications - Electronics Command (CECOM) and while active
primarily functioned as an Army installation engaged in communications intelligence. VHFS is located
approximately 40 miles southwest of Washington, D.C., in Fauquier County, Virginia, as shown ort Figure 1
The installation occupies approximately 701 acres of land near the town of Warrenton Virginia
Approximately 150 acres of the installation are improved grounds in the southern portion of the property used
for industrial operations, administration buildings, and residential housing. Approximately 94 acres in the
eastern portion of the property are mature hardwood forest, and the majority of the remaining 457
unimproved and semi-improved acres in the northern portion of the property are used for stationary and
mobile antenna operation sites.
The facility was designated for closure in March, 1993, under the Base Realignment and Closure (BRAC)
Act, Pursuant to the decision to close the installation, an Enhanced Preliminary Assessment (ENPA) and a
Community Environmental Response Facilitation Act (CERFA) investigation of VHFS were conducted by
Science Applications International Corporation (SAIC) to assess the environmental condition of the
installation. The ENPA and CERFA investigations were completed in April and May, 1994, respectively The
ENPA identified 42 AREEs from the review of installation records, aerial photographs, installation personnel
interviews, federal and state regulatory records, and visual inspection. Of these 42 AREEs 27 were
recommended for further investigation.
These 27 AREEs were investigated from September, 1994, to June, 1995, as part of the Site Inspection (S!)
conducted by SAIC. The objective of the SI was to determine the presence or absence of contamination and
the chemical nature of any detected contamination. The final SI Report, which was completed in June 1996
identified 24 AREEs which required further investigation. In addition, four new AREEs were identified'during
site reconnaissance to warrant further investigation subsequent to the SI. AREEs that were determined to
warrant further investigation and are located in the Phase II reuse area (shown on Figure 2) were
investigated between February and April, 1997, as part of the Phase II reuse area Remedial Investigation
(Rl) conducted by ICF Kaiser Engineers, Inc. (ICF KE). The purposes of the Rl were to evaluate- 1) the
nature and extent of contamination; and 2) the level of risk posed to human health and the environment The
draft Rl Report for the Phase II reuse area was completed in January, 1998, and is currently undergoing
regulatory review. s s
Four AREEs were identified in the Rl as having soil contamination which poses unacceptable human health
risks and/or significant adverse ecological effects:
• AREE 2 - Sewage Treatment Plant;
• AREE 4 - Auto Craft Shop;
• AREE 28-5 - Former Service Station Abandoned Underground Storage Tanks (USTsV
and
• AREE 31-Construction Debris Pile#1.
Tne locations of these AREEs are shown on Figure 2.
RESULTS OF THE REMEDIAL INVESTIGATION
The Rl for these four AREEs was conducted to evaluate the nature and extent of contamination
associated with past site activities. Environmental samples collected and analyzed during the Rl were
used in conjunction with the results from the SI to assess the condition of each of the AREEs The
environmental media investigated included surface soil (0 to 2 feet below ground surface [bgsj)
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JEFFERSOh
(W. Va.) (
HOWARD
MONTGOMERY
MARYLAND
LOUDOUN
\: ANNE ARUNDEL
VIRGINIA
--' V
' WASHINGTON D.C.'~
FAIRFAX
Vint Hill
Farms Station
PRINCE WILLIAM
PRINCE GEORGES
CALVERT
FAUQUIER ... •' -'
CHARLES
STAFFORD
ST. MARY'S
KING GEORGE
FIGURE 1
GENERAL LOCATION
OF VHFS
-N-
0 5 10
SCALE IN MILES
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LEGEND
ROAD
X'' STREAM
11 REUSE AREA
AREEs:
2) SEWAGE TREATMENT PLANT
4) AUTO CRAFT SHOP
FORMER SERVICE STATION ABANDONED USTs
FIGURE 2
GENERAL LOCATIONS
OF APPPc ATX/HCC
-------
subsurface soil (2 feet to'approximately 10 feet bgs), surface water, sediment, and groundwater.
Analytical results were compared to background concentrations and regulatory screening levels to
determine if environmental media had been adversely impacted by site activities. A brief description of
each of the four AREEs and the significant findings of the Rl and SI are presented in the following
paragraphs. A detailed presentation of the samples collected and the analytical results can be found in
the draft Phase II Reuse Area Rl Report, now available in the Information Repository at the Fauquier
County Library.
AREE 2- Sewage Treatment Plant
AREE 2 is the sewage treatment plant (STP) which serves approximately 70 VHFS permanent residents and
500 daily employees and has been in service since 1952. The plant has treated sanitary wastewater,
industrial wastewater from VHFS operations (photographic, painting, laboratory, vehicle washing, and meta!
etching), and surface water runoff. The facility discharges treated effluent to South Run under a Virginia
Pollutant Discharge Elimination System (VPDES) permit Before 1980, sludge was stored in piles on the
ground near South Run.
Surface soil, subsurface soil, sediment, surface water, and groundwater samples were collected at AREE 2
as shown on Figure 3. Metals were detected in surface soil above residential soil risk-based concentrations
(RBCs) established by USEPA Region III for screening analytical results. Mercury (4.3 parts per million
[ppm]) was detected above the residential soil RBC of 2.3 ppm in surface soil sample SS-02-002.
Benzo(a)pyrene, a polynuclear aromatic hydrocarbon (PAH), was present above residential soil RBCs in one
surface soil sample downgradient of the former sludge pile. Based on the results of the subsurface soil
samples, subsurface soil has not been impacted by AREE 2 activities.
AREE4 • Auto Craft Shop
The Auto Craft Shop (Building 306 and former Building 308) was used as the motor pool from 1943 to 1967,
and as a vehicle maintenance area where military personnel performed maintenance on their private vehicles
from 1968 to 1994. The buildings were used to store oil, solvents, and lubricants for vehicle maintenance
activities as well as spent solvent and waste oil filters. The buildings have concrete floors with no curbs or
floor drains. Gasoline and oil spills have been recorded in this area and were cleaned up using absorbents.
A 1,000kjallon UST was used to store waste oil prior to its removal in July, 1990. A plume of petroleum
contamination currently lies under the shop as a result of leaks from the UST. A corrective action for this
plume has been implemented. Three areas where surface runoff/discharge from AREE 4 occurs have been
identified (see Figure 4). An outdoor vehicle wash rack near former Building 308 drained into a grit chamber,
which has been removed. The grit chamber was used to settle the solids prior to discharge of water from the
vehicle wash rack via a ceramic pipe into the. wooded area south of former Building 308. The Moor of the grit
chamber and 'the associated contaminated soil were removed during the Phase II reuse area Rl field
investigation. A storm sewer drain located west of Building 306 and former Building 308 discharged surface
runoff to the field south of the Auto Craft Shop. Surface runoff also drains south of the Auto Craft Shop near
the former hydraulic lift.
Surface soil, subsurface soil, and groundwater samples were collected at AREE 4 as shown on Figure 4.
Total petroleum hydrocarbon (TPH) contamination, exceeding the Virginia TPH soil action level for USTs of
100 ppm, was present in surface soil samples collected near the storm sewer discharge: area, former
hydraulic lift surface runoff area, and wash rack discharge area. The maximum TPH concentration (1,860
ppm) was detected in surface soil sample SS-04-002 collected at the former hydraulic lift surface runoff area.
Metals were detected in surface soil above residential soil RBCs at al! three surface runoff/discharge areas.
Lead contamination exceeding the USEPA screening level for lead in residential soil of 400 ppm was
detected in surface soil at all three surface runoff/discharge areas. The maximum lead concentration (1,700
ppm) was detected in a surface soil sample collected from the storm sewer discharge area. Four PAHs
(benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, and indeno[1.2,3-cdjpyrene) exceeding the
residential soil RBCs are present in surface soil at the wash rack discharge area. Only benzo(a)pyrene is
present in surface soil above the residential soil RBC (0.088 ppm) in all three surface runoff/discharge areas.
The maximum benzo(a)pyrene concentration of 1.52 ppm was detected in surface soil sample RISS4-5
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UNNAMED TRIBUTARY
TO SOUTH RUN
SOIL LOCATIONS
AND RISS2-2) ARE
WITH THE SOIL
BORING LOCATKKjS (RISB2-1
AND R1S82-2).
1 UONITORING WELL NUMBERS
2UW-1 THROUGH 2UW-3 HAVE
BOH MODIFIED FROM THE
NUMBERS REPORTED IN THE
ORIGINAL HELD !NVEST1GATIONS
IN ORDER TO PROVIDE UNIQUE
WELL NUMBERS FOR THIS
REPORT.
LEGEND:
O-
IMPACTED SURFACE SOIL AREA
(APPROXIMATE)
BUILDING
VHFS BOUNDARY
PAVED ROAD
FENCE
STREAM
TRIBUTARY
....TOPOGRAPHIC CONTOUR (FT MSL)
. SI SURFACE SOIL SAMPLE LOCATION
EXISTING MONITORING WELL
PHASE II Rl MONITORING WELL
.PHASE II Rl SOIL BORING LOCATION
100
SCALE IN FEET
RGURE 3
SI AND Rl SAMPLE LOCATIONS
FOR AREE 2-SEWAGE
TREATMENT PLANT
0..PHASE II Rl SURFACE WATER/SEDIMENT SAMPLE LOCATION
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FORMER
HYDRAULIC LIFT
RIS84-6
RE84-7
"SS-04-
FORMER GRtT
:—CHAMBER
GROUNDWATER
ROW DIRECTION
(BASED ON'AREE 4 WELLS)
MW4
RISB4-
SS-04-003
RISB4-
R1S84-3
I. SURFACE SOIL SAMPLE LOCATIONS (HSS4-3 THROUGH
RSS4-11) ARE CO-LOCATED WTO THE SOIL BORING
LOCATIONS (RIS8<-3 THROUGH R1S84-11).
2. MONITORING WEIL NUMBERS 4MW-1 THROUGH 4MW-3
HAVE BEEN MODIFIED FROU THE NUMBERS REPORTED
"HE ORIGINAL FIELD INVESTIGATIONS IN ORDER TO
PROVIDE UNIQUE WELL NUMBERS FOR THIS REPORT.
APPROXIMATE AREA
OF EXCAVATION
IMPACTED SURFACE SOIL AREA
(APPROXIMATE)
~x—*-. FENCE
^•H BUILDING
===== ROAD
= ---- STORM DRAIN
-—410 .TOPOGRAPHIC CONTOUR (FT MSI)
® SI SOIL BORING LOCATION
• SI SURFACE SOIL SAMPLE LOCATION
O PHASE d Rl SOIL BORING'LOCATION
®. EXISTING MONfTORING WELL
•fc PHASE II Rl MONITORING WELL
SCALE IN FEET
FIGURE 4
SI AND Rl SAMPLE LOCATIONS
FOR AREE 4 -
AUTO CRAFT SHOP
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SSS 'n th™aSH faCk dischar9e area Based on 'he results of the subsurface soil samples from the three
surface runoff/d.scharge areas, subsurface soil has not been impacted by AREE 4 activities.
AREE 28-5 • Former Service Station Abandoned USTs
AREE 28-5 consists of the Former Service Station Abandoned USTs located under the asphalt parkina lot
approximately 60 ft northwest of the former service station (Building 220). Three 5 000-gallon steel USTs
were used for the storage of gasoline and diesel fuel products. The USTs were app oximltely 30 years Id
and were in serves until 1983. Environmental Restoration Company (ERC) removed L USTs an"
associated pipelines in December, 1994. na
Subsurface soil and groundwater samples were collected at AREE 28-5 as shown on Figure 5 TPH
ShTfJv ^f tn9 f18 Vir9inia TPH S0i' aCti°n level for USTs of 10° PPm- was detected in subsurface
so,l m the vicinity of the former pump .sland at depths ranging from 2 ft fags to at least 10 ft bqs The
maximum TPH concentration (5.273 ppm) was detected at a depth of 8-10 ft bgs in soil boring RISB28-5-1
AREE 31 - Construction Debris Pile #1
oMh! VHF9 n°nntiCtir *?** ^ ****? ^P™™3'^ 20° to 30° * northwest of the southernmost tip
of the VHFS property boundary ,n a predominantly wooded and vegetated area. The pile consists of
construction debns including, but not limited to. concrete pipe, corrugated steel pipe, steel footers
XS blocks' cement slat* and i •
Surface and subsurface (from a test pit) soil samples were collected at AREE 31 as shown on Figure 6
TletadCrnm'Um; ^^n'^ ** PAH ***"***" «« P**"* in surface soi. sample RISS31-2
The lead concentration of 3,610 ppm exceeded the USEPA screening level for lead in residential soil of 400
soT iSST1!? a?dQCOpper conflations of 7.59 ppm and 1 ,880 ppm exceeded their respective residential
benzo?klunranthP F™ ^ ™ ^ ^ PAHs (ben2°[a]anthracene, benzo[b]fluoranthene
one 2 mo?I H ' ^enz°tato'rene- and indeno[1.2.3-cd]pyrene) exceeded the residential soil RBCs by
SL.PH a»7^ p5 magnitude In surface soil samP'^ RISS31-2. For example. benzo(a)pyrene was-
soil RBC of °-°88 ppm- subsurface soii has n
HUMAN HEALTH AND ECOLOGICAL RISK ASSESSMENT
AssmeBRA> .was conducted as part of 'the Rl to assess the human health and
.
h 'f the contamination at ^e AREEs was not remediated. The Human
.
n th Prep3red t0 SVaIUate the ma9nitude of potential adverse effects on
? associated with current and potential future (assuming residential development of the property)
PV e propery
to ch^r, f S' r613 >ted C?lmiCalS 3t the AREES' The Ecol°9ical Risk Assessment (ERA) was conducted
to characterize the potential threats to ecological receptors posed by contaminants at the AREEs.
The HHRA follow? a four-step process:
* Selection of Chemicals of Potential Concern - identities the contaminants of potential concern
based on their toxicity, frequency of occurrence, and concentration by comparing the maximum
concentrations of detected chemicals with RBCs which are health-protective 'chemical
concentrations that are back-calculated using toxicity criteria, a 1x10* target carcinogenic risk or
a 0.1 hazard quotient (defined below), and conservative exposure parameters;
• Exppsure Assessment - identifies the potential pathways of exposure, and estimates the
concentrations of contaminants to which people may be exposed as well as the frequency and
duration of these exposures;
• Tpxipitv Assessment - determines the toxic effects of the contaminants; and
• Risk Characterisation . provides a quantitative assessment of the overall current and future risk
to people from site contaminants based on the exposure and toxicity information.
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1
GEOPHYSICAL AND
SOIL ORGANIC VAPOR
SURVEY AREA
ASSUMED
GROUNDWATER
FLOW DIRECTION
LEGEND:
SS3IMPACTED SOIL AREA (APPROXIMATE)
•• BUILDING
.- PAVED ROAD
-+10-...TOPOGRAPHIC CONTOUR (FT MSL)
ffl UST FILL PIPE
i..'. FORMER UST LOCATION
® SI SOIL BORING LOCATION
'$- ..PHASE II Rl MONTORING WELL
O....PHASE II Rl SOIL BORING LOCATION
10
20
SCALE IN FEET
FIGURE 5
SI AND Rl SAMPLE LOCATIONS
FOR AREE 28-5 - FORMER
SERVICE STATION USTs
-------
APPROXIMATE LOCATION
OF CONSTRUCTION
DEBRIS PILE #1
LEGEND:
IMPACTED SURFACE SOIL AREA
(APPROXIMATE)
VHFS BOUNDARY
PAVED ROAD
-x— x — x- ................................. FENCE
— -420 — . ......... TOPOGRAPHIC CONTOUR (FT MSI)
1 '. .......... PHASE II Rl TEST PIT LOCATION
A. ................ PHASE II Rl TEST PIT SAMPLE
•• .................... PHASE II Rl SURFACE SOIL
_ _ SAMPLE LOCATION
100
SCALE IN FEET
FIGURES
Rl SAMPLE LOCATIONS
FOR AREE 31 - CONSTRUCTION
DEBRIS PILE#1
10
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current workers who could b^e^sed to^^m^^u^soii'd^S^ ^tia, risks to
be exposed to contamination in surface soil, surface water, and sediment In additionth^M^^0 COUld
z^zmxzx^^
groundwater, surface soil surface water and sediment Pntont i i- » * exP°sed to contaminants in
could be exposed to contaminants in subsurface soil were also, evataTed^he HHR?^'0" WWk8r8 Wh°
noncarcinogenic health effects if the AREE is not remedied. dlCateS a P°tential tor
The ERA also follows a four-step process:
^,^^ -
Exposure ?f*~s*rf nt - estimates exposure point concentrations for selected indicator species-
•' ' adverss effects from
eer , •
fi^si's^scr.isss'i'.-SKisa".;
.-s s =
~~~
AREE 2 - Sewage Treatment Plant
AREE 2. Dscountmg naturally-occurring metals that were statistically determined to be within background
11
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concentrations, the highest estimated upper-bound excess lifetime cancer risk (8X10*) is for adult residents
exposed to site-related contaminants in surface soil by dermal absorption, and the highest noncarcinogenic
risk (Hl=0.2) is for child residents exposed to site-related contaminants in surface soil by incidental ingestion.
The ERA determined that contaminants in surface soil at AREE 2 pose significant potential adverse
ecological effects. The significant potential adverse ecological effects result primarily from mercury. Mercury
results in significant potential adverse ecological effects for terrestrial plants, earthworms, robins, and shrews,
with the greatest potential adverse ecological effects occurring to robins (EEQ of 3,500).
The mercury contamination downgradient of the former sludge pile is recommended for remediation. The
impacted area has approximate dimensions of 75 ft by 25 ft by 2 ft deep, as shown on Figure 3.
AREE 4 - Auto Craft Shop •
The HHRA concluded that, under both current and future land-use conditions, the risks to workers,
trespassers, residents, and excavation workers are acceptable for exposure to site-related contaminants!
except for lead, in soil at AREE 4. Discounting naturally-occurring metals that were statistically determined to
be within background concentrations, the highest estimated upper-bound excess lifetime cancer risk (5X10-5)
is for adult residents exposed to site-related contaminants in surface soil by dermal absorption, and the
highest noncarcinogenic risk (Hl=0.3) is for child residents exposed to site-related contaminants in surface
soil by dermal absorption.
The human health risks associated with exposure to lead contamination in surface soil at AREE 4 were
evaluated using the Integrated Exposure Uptake Biokinetic (IEUBK) Model recommended by USEPA for
evaluating lead exposures for young children in residential settings. The tEUBK Model calculates blood lead
levels which result from exposures to lead which may then be compared to blood lead levels of toxicoiogical
significance for purposes of risk evaluation. The IEUBK Model run for AREE 4 predicted a geometric mean
blood lead level of 6.9 ng/dl_, with 19.81 percent of the population exceeding the blood lead level of concern
(10 ng/dL). The USEPA currently finds 5 percent of the population exceeding the blood lead level of concern
acceptable. Therefore, the IEUBK model results indicate that if AREE 4 was developed for residential use in
the future, the lead concentrations in the surface soil may be a potential problem for young children.
The ERA determined that metals in surface soil at AREE 4 pose significant potential adverse ecological
effects. The significant potential adverse ecological effects result primarily from lead, selenium, mercury, and
zinc. Lead, selenium, and zinc result in significant potential adverse ecological effects to terrestrial plants
with EEQs of 34, 38, and 15, respectively. Mercury results in significant potential adverse ecological effects
to robins (EEQ of 210) and shrews (EEQ of 13).
The metals contamination in the surface soil at the three surface runoff/discharge areas is recommended for
remediation. The approximate dimensions of the impacted area at each of the three surface runoff/discharge
areas are 15ftx15ftx2ft deep, as shown on Figure 4.
AREE 28-5 - Former Service Station Abandoned USTs
The ERA did not evaluate AREE 28-5 because this area is covered with asphalt, thus eliminating the
potential for exposure to ecological receptors.
The HHRA determined that contamination at AREE 28-5 does not pose an unacceptable human health risk
under either current or potential future land-use conditions. In fact, no chemicals of potential concern were
identified in subsurface soil at AREE 28-5 in the HHRA. However, risks associated with exposures to TPH
could not be assessed in the BRA because this analytical parameter represents a mixture of chemical
constituents, Since TPH measurements give no indication of the chemical constituents present or their
respective concentrations, they cannot be used to predict risks. Although risks associated with TPH cannot
be estimated. TPH contamination in subsurface soil in the vicinity of the former pump island at AREE 28-5
exceeds the Virginia TPH soil action level for USTs.and is, therefore, recommended for remediation. The
impacted area is approximately 20 ft x 20 ft x 10 ft deep (minimum),'as shown on Figure 5.
12
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AREE 31 - Construction Debris Pile #1
The HHRA determined that, under current IstHd-use conditions, the risks to workers are unacceptable for
exposure to contaminants in surface soil at AREE 31. Under future land-use conditions assuminq that
AREE 31 is not remediated, the risks to potential adult and child residents are also unacceptable for
exposure to contaminants in surface soil at AREE 31. The highest estimated upper-bound excess lifetime
cancer nsk is for adult residents exposed to contaminants in surface soil by dermal absorption- this risk is
1x10 (i.e., 1 in 1,000 residents may develop cancer caused by exposure to contaminants in surface soil at
AREE 31). Cancer nsks were due primarily to exposures to benzo(a)pyrene and other PAHs The highest
noncarcinogenic risk is for child residents exposed to contaminants in surface soil by incidental ingestion- the
HI is estimated to be 2, indicating that adverse effects could occur if child residents were exposed to
contaminants in surface soil. The critical effect caused by exposure to noncarcinogenic contaminants in
surface soil at AREE 31 is gastrointestinal irritation due to copper and iron (which was statistically determined
to be within background concentrations). It should be noted that major uncertainties exist regarding the
assessment of dermal absorption exposures (particularly associated with dermal absorption factors)-
therefore, estimated risks are likely to be over-estimated for the dermal absorption exposure route.
As explained in the AREE 4 discussion, lead contamination in surface soil at AREE 31 was evaluated using
the IEUBK Model which predicted a geometric mean blood lead level of 15 fag/dL, with 78.4 percent of the
population exceeding the blood lead level of concern (10 ng/dL). Again, the USEPA currently finds 5 percent
of the population exceeding the blood lead level of concern acceptable. Therefore, the IEUBK Model results
indicate that if AREE 31 was developed for residential use in the future, the lead concentrations in the surface
soil may be a potential problem for young children.
The ERA determined that contaminants in surface soil at AREE 31 pose significant potential adverse
ecological effects. The significant potential adverse ecological effects result primarily from metals (copper
. lead, mercury, and selenium) and one PAH (benzo[a]pyrene). Mercury results in significant potential adverse
ecological effects for robins and shrews, with the greatest potential adverse ecological effects occurring to
robins (EEQ of 250). Copper results in significant potential adverse ecological effects for terrestrial plants
and earthworms, with the greatest potential adverse ecological effects occurring to earthworms (EEQ of 38)
Selenium and lead result in significant potential adverse ecological effects for terrestrial plants with EEQs of
25 and 72, respectively. Benzo(a)pyrene results in significant potential adverse effects to earthworms with
an EEQ of 13.
The most significant contamination at AREE 31 is in surface soil in the vicinity of surface soil sample RISS31-
2 located in the northeastern portion of the debris pile, which is recommended for remediation. The impacted
area has approximate dimensions of 50 ft x 15 ft x 2 ft, as shown on Figure 6.
REMEDIAL ACTION OBJECTIVES
Remedial action objectives are specific goals to protect human health and the environment. The remedial
action objective for the four AREEs is to minimize the potential for contaminated soil to pose unacceptable
risks to human or ecological receptors.
CLEANUP LEVELS ESTABLISHED FOR THE PREFERRED ALTERNATIVE
USEPA has established soil cleanup levels for the contaminants that contribute to the unacceptable risk
determination at each of the four AREEs. The soil cleanup levels are presented in Table 1. The soil cleanup
level for AREE 2 is based on concentrations which are protective of ecological receptors (EEQ=10). The soil
cleanup level for lead in surface soil at AREEs 4 and 31 is based on the USEPA screening level for lead in
residential soil of 400 ppm. The soil cleanup levels for other metals at AREE4 are based on concentrations
which are protective of ecological receptors. The soil cleanup level for AREE 28-5 is based on the Virginia
TPH soil action level for USTs of 100 ppm. USEPA established the soil cleanup levels for PAHs at AREE 31
based on a 1X10"6 (one in 1,000,000 people) upper-bound excess lifetime cancer risk for the potential future
13
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Table 1
Cleanup Levels Established for Soil at the Four AREEs
Constituents
Cleanup Levels (ppm)
AREE 2 - SEWAGE TREATMENT PLANT
Mercury (Ecological risk)
0.1 92 (a)
AREE 4 -AUTO CRAFT SHOP -j
Lead (Human Health & Ecological risk)
Mercury (Ecological risk)
Selenium (Ecological risk)
Zinc (Ecological risk) (c)
400 (d)
0.534 (a) j
10 (a)
500 (a)
AREE 28-5 - FORMER SERVICE STATION ABANDONED USTs
TPH
100 (e)
j AREE 31 - CONSTRUCTION DEBRIS PILE #1
! Benzo(a)anthracene (Human Health risk)
Benzo(a)pyrene (Human Health & Ecological risk)
Benzo(b)fluoranthene (Human Health risk)
; Benzo(k)fluoranthene (Human Health risk) (c)
Copper (Ecological risk)
! lndeno(1,2.3-cd)pyrene (Human Health risk)
Lead (Human Health & Ecological risk)
j Mercury (Ecological risk)
Selenium (Ecological risk)
0.87 (b) |
0.087 (b) I
0.87 (b)
8-7 (b) .;;
500 (a)
0.87 (b) |
400 (d) ;
0.48 (a)
10 (a) j
TPH - total petroleum hydrocarbons
USTs - underground storage tanks
(a) Based on a concentration which is protective of ecological receptors (EEQ=10).
(b) Human health cleanup levels are based on a 1X10"6 upper-bound excess lifetime cancer risk for the
potential future residential land-use scenario.
(c) These compounds contribute to but do not drive unacceptable risk.
(d) USEPA screening level for lead in residential soil.
(e) Virginia TPH soil action level for USTs.
14
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residential use scenario. The soil cleanup levels for metals, other than lead, at AREE 31 are based on
concentrations which are protective of ecological receptors.
SUMMARY OF REMEDIAL ALTERNATIVES
Two remedial alternatives were evaluated to address soil contamination at AREEs 2, 4, 28-5 and 31 The
range of remedial alternatives considered was limited by the nature and extent of the contamination Since
the amount of soil requiring remediation is relatively small (approximately 400 cubic yards) it was not
practical to consider active treatment or containment options in terms of cost-effectiveness and
implementability. The following remedial alternatives were evaluated:
• Alternative 1 - No Action; and
• Alternative 2 - Soil Removal.
Alternative 1 - No Action
The National Contingency Plan (NCR) and CERCLA, as amended by the Superfund Amendments and
Reauthonzation Act (SARA), require that a No Action alternative be considered as a baseline for comparison
to other alternatives. No action would be taken to address site contamination under this alternative In
accordance with Section 121 of CERCLA, each AREE would be'reviewed at least once every five years to
re-evaluate site conditions and to determine the need for remedial action to protect human health and the
environment.
Alternative 2 • So/7 Removal
Under this alternative, all contaminated soil exceeding the established cleanup levels would be excavated
transported off site by truck, and disposed using a combination of •permitted off-site hazardous waste'
construction debris, and/or municipal landfills or incinerators, as appropriate based on analytical results '
Approximately 400 cubic yards of impacted soil would be excavated as part of this alternative, followed by
confirmation sampling to assure adequate removal of ail soil exceeding the cleanup levels. Upon completion
of the soil excavation, disturbed areas would be backfilled, regraded, and either vegetatively stabilized or
paved (AREE 28-5). The five-year review does not apply to this alternative because hazardous substances
above risk-based cleanup levels would not remain on site.
EVALUATION OF ALTERNATIVES
CERCLA requires a comparison of the alternatives using nine evaluation criteria: overall protection of human
health and the environment; compliance with applicable or relevant and appropriate requirements (ARARs);
long-term effectiveness and permanence; reduction of toxicity, mobility or volume through treatment; short-
term effectiveness; implementability; cost; and regulator and community acceptance. The first two criteria
are considered by USEPA to be threshold criteria which must be met by each alternative. The nine
evaluation criteria are described below:
Overall protection of human health and the environment addresses whether or not a remedy
provides adequate protection and describes how risks posed through each pathway are
eliminated, reduced, or controlled through treatment, engineering controls, or institutional
controls.
• Compliance with ARARs addresses whether or not a remedy will meet all of the applicable
or relevant and appropriate requirements of other federal and state environmental statutes
and requirements or provides grounds for invoking a waiver.
• Long-term effectiveness and permanence refers to the ability of a remedy to maintain
, reliable protection of human health over time, once cleanup goals have been met
15
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• Reduction of toxicitv. mobility, or volume through .treatment is the anticipated performance of
the treatment technologies a remedy may employ.
• Short-term effectiveness addresses the period of time needed to achieve protection and any
adverse impacts on human health and the environment that may be posed during the
construction and implementation period until cleanup goals are achieved.
• Implemeptgbility is the technical and administrative feasibility of a remedy, including the
availability of materials and services needed to implement a particular option.
• Cost includes estimated capital and operation and maintenance costs, and net present
worth costs.
• Regulator acceptance indicates whether, based on their review of the Rl and Proposed
Plan, the regulators (VDEQ and USEPA) concur, oppose, or have no comment on the
preferred alternative at this present time.
• Community acceptance will be assessed in the Decision Document following a review of the
public comments received on the Rl and the Proposed Plan.
The comparative analysis of the alternatives was conducted based upon these evaluation criteria and is
described below.
Overall Protection of Human Health and the Environment
The no action alternative (Alternative 1) is not protective of-human health or the environment because the
risks to potential future residents and the potential adverse effects to ecological receptors remain unchanged,
which is unacceptable. Therefore, the no action alternative was eliminated from further consideration and will
not be discussed further.
Alternative 2 provides adequate protection of human health and the environment by removing contaminated
soil, thereby eliminating the potential for exposure.
Compliance with ARARs
Alternative 2 has been designed to achieve or comply with ARARs. This alternative will satisfy the
established cleanup levels since all soil that is contaminated above applicable cleanup levels will be
removed. In addition, the removal and disposition of contaminated soil during implementation of Alternative 2
would be_done in accordance with federal and Virginia solid and hazardous waste regulations. During soil
excavation. Virginia Regulations for the Control and Abatement of Air Pollution may apply. Ambient air
conditions would be monitored during excavation activities to assure acceptable air quality. As necessary
based on the ambient air monitoring, water sprays would be used to keep dust levels down.
Long-term Effectiveness and Permanence
Alternative 2 would provide for the permanent removal of contaminated soil to a permitted off-site location
designed to prevent contaminant migration and exposures to human and ecological receptors.
Reduction of Toxlcity, Mobility, or Volume Through Treatment
Alternative 2 provides reduction of contamination at the AREEs by removing contaminated soil. The toxicity
and volume of the contaminated soil would not be affected by this alternative; however, the mobility of the
contaminants would be reduced because the off-site disposal facilities used would be designed to prevent
contaminant migration.
Because treatment of the contaminated soil at the AREEs was not found to be practicable due to the small
volume of impacted soil, Alternative 2 does not satisfy the statutory preference for treatment as a principal
element of the remedy.
16
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Short-term Effectiveness .
Alternative 2 is considered to be effective in the short term because the volume of soil to be excavated is
relatively small and would result in limited negative impacts to human health or the environment. Dust
exposure to workers and adjacent residents would be controlled during excavation activities by water sprays
as. needed. Prior to excavation operations, temporary erosion control structures would be installed to prevent
entry of storm water into the soil excavation areas and prevent erosion and movement of soil from
contaminated areas. Although truck traffic would be increased during implementation of Alternative 2 the
implementation period (approximately one month) is short and the number of trucks per day would be'less
than 20.
Implementability
Alternative 2 is considered readily implementable . Licensed transporters and permitted disposal facilities are
currently available.
Cost
The cost to implement Alternative 2 is estimated at $260,000.
Regulator Acceptance
VDEQ and USEPA are currently reviewing this Proposed Plan. VDEQ and USEPA comments will be
addressed in the Decision Document.
Community Acceptance
Community acceptance of the preferred alternative will be evaluated at the close of the public comment
period by considering both oral and written comments received during the public comment perioc.
PREFERRED ALTERNATIVE
Alternative 2, Soil Removal, is recommended by the U.S. Army as the preferred alternative for AREEs 2, 4,
28-5, and 31. This remedial alternative is a permanent solution that offers long-term effectiveness since the
contaminated soil is removed to cleanup levels and transported off site for proper disposal. This remedial
alternative would be designed to comply with ARARs. The excavation and disposal of contaminated soil
would be done in accordance with federal and Virginia solid and hazardous waste regulations. The
estimated cost to implement this alternative is $260,000, and the on-site activities would require
approximately one month to complete.
17
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The United States Army
at Vint Hill Farms Station, Virginia
Invites Public
Comment
ON A PROPOSED
ENVIRONMENTAL CLEANUP
ConcerningFouTAreas'
Requiring Environmental Evaluation:
2,4,28-5, & 31
Please Come To Our
* PUBLIC MEETING»
Thursday, April 9,1998 * 7:00 p.m.*
* Warrenton Middle School Auditorium *
244 Waterloo Street • Warrenton, VA
('Sign Language Interpreter will be present)
PURPOSE: TO DISCUSS AND PRESENT THE REMEDIAL
ALTERNATIVES FOR THE SITES IDENTIFIED ABOVE.
The U.S. Army, inconsullalion wilh the U.S. Environmetllal Pro-
tection Agency (USEPA) Region III and the Virginia Depart-
ment of Environmental Quality (VDEQ), invites public comment
on its Proposed Plan for remediating contaminated soil at the
following Areas Requiring Environmental Evaluation (AREEs)
on Vint Hill Farms Station (VHFS), Virginia: AREE 2 - Sewage
Treatment Plant; AREE 4 - Auto Craft Shop; AREE 28-5 -
Former Service Station Abandoned Underground Storage Tanks;
and AREE 31 - Construction Debris Pile #1. Before selecting a
final remedy, VHFS will consider all written and oral comments
received during the public comment period.
The U.S. Army will be accepting comments during a
30-day PUBLIC COMMENT PERIOD which
begins Thursday. March 26.1998
and ends Friday. April 24.1998.
WRITTEN COMMENTS MAY BE SUBMITTED
TO THE FOLLOWING ADDRESS:
Kevin Bell, Public Affairs Officer
Public Affairs Office (Bldg. 2500)
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ATTACHMENT 2
CLEANUP LEVEL DEVELOPMENT DOCUMENTS
-------
-------
HUMAN HEALTH RISK-BASED REMEDIATION GOALS
AREAS REQUIRING ENVIRONMENTAL EVALUATION (AREEs) 4 AND 31
VINT HILL FARMS STATION (VHFS)
Risk-based remediation goals for VHFS based on human exposures at the site were calculated for selected
chemicals detected in surface soil in areas proposed for remediation (i.e., surface soil at AREEs 4 [Auto Craft
Shop] and 31 [Construction Debris Pile #1]). Based on a review of the exposure pathways evaluated in the
risk assessment, risk-based remediation goals were calculated for chemicals contributing to pathway upper-
bound excess lifetime cancer risks greater than 1x10"* and/or hazard indices (His) greater than or equal to 1.
The development of risk-based remediation goals focused on the incidental ingestion exposure pathway only.
Risk-based remediation goals did not incorporate exposures through the dermal route of exposure due to the
great uncertainties associated with assessing derma! exposures. For example, major uncertainties exist in
the extent to which chemicals are percutaneously absorbed and in the extent to which chemicals partition
from soil to skin leading to uncertainty in the use of default dermal absorption factors in the evaluation of risk.
Uncertainties also exist in the use of adjusted oral toxicity criteria to evaluate dermal exposure pathways
depending on how closely the factors used to adjust oral toxicity criteria reflect the difference between the
oral and dermal routes.
In the VHFS human health risk assessment (HHRA), surface soil incidental ingestion pathways with upper-
bound excess lifetime cancer risks greater than IxlO/4 and/or His greater than or equal to 1 were associated
with adult and child resident exposures at AREE 31. In addition, the U.S. Environmental Protection Agency's -
(USEPA's) residential soil screening level for lead (USEPA, 1994) was exceeded at AREES 4 and 31. The
risk-based remediation goals for selected chemicals in surface soil were developed based on the more
conservative residential receptor, consistent with USEPA Region III methodology for calculating risk-based
concentrations (i.e., using combined child/adult residential exposure parameters for carcinogenic compounds
and using child residential exposure parameters for noncarcinogenic compounds).
Risk-based remediation goals were calculated for carcinogenic chemicals associated with chemical-specific
risks greater than or equal to 1x10* and noncarcinogenic chemicals contributing to a HI of 1 for a specific
target organ. Risk-based remediation goals were not calculated for inorganic compounds that were
statistically determined to be within background levels in the risk assessment. For selected carcinogenic
chemicals, risk-based remediation goals were developed using a target risk level of IxlO"6, which is at the
low end of USEPA's target risk range for health-protectiveness at Superfund sites. For selected
noncarcinogenic chemicals, risk-based remediation goals were calculated to correspond to a target hazard
quotient of 1. If any of the noncarcinogenic compounds for which remediation goals were calculated 'had
similar target organs/critical effects, then the risk-based remediation goal for that noncarcinogenic compound
was divided by the number of compounds having the same target organ/critical effect (i.e., if three
noncarcinogenic compounds had "liver* as the target organ, the individual remediation goals would be
divided by three). For chemicals that exhibit both carcinogenic and noncarcinogenic effects, the selected
remediation goal represents the lower of the two calculated goals.
The following sections present the exposure assumptions and equations used to calculate the risk-based
remediation goals for chemicals in surface soil. Table 1 presents the toxicity criteria used to calculate the
risk-based remediation goals for chemicals in surface soil.
Surface Soil Risk-Based Remediation Goals
Risk-based remediation goals were calculated for chemicals in surface soil based on combined child/adult
resident exposures for carcinogens and on child resident exposures for noncarcinogens for the incidental soil
ingestion pathway. The equations and exposure assumptions used to calculate risk-based remediation goals
for surface soil are presented below. Equations are presented separately for chemicals exhibiting
carcinogenic and noncarcinogenic effects.
DACA31-95-D-0083 1 ' Human Health Risk-based Remediation Goats
TERC18-10 Areas Requiring Environmental Evaluation 4 and 31
March 6, 1998 Vint Hill Farms Station
-------
TABLE 1
CHRONIC ORAL TOXICITY CRITERIA
Oral Toxlctty Criteria for Carcinogen!
Weight-of-
Oral Slope Factor Evidence Slope Factor
I (mg/kg-dayr1 Class (a) .Source
Oraf 'ioxlctty Criteria for Noncarclrtogens
Reference Dose
(RfD) Uncertainty Factor Target Organ/
Chemical
Organic*
8enzo(a)anthracane
Benzo(a)pyrens
Banzo(b}nuoranlhene
Benzo(k)fluoranthene
lndeno{1.2,3-c.d)pyrene
Inorganic*
Lead
RID Source
7.3E-01
7.3E-KJO
7.3E-01
7.3E-02
7.3E-01
(d)
(d)
(d)
82
B2
B2
B2
B2
B2
IRIS
IRIS
IRIS
IRIS
IRIS
IRIS
CNS
IRIS
(a) USEPA weighi-of-evidence classification scheme for carcinogens:
A * Human Carcinogen, sufficient evidence of carcJnogenfcfty in humans;
B1 « Probable Human Carcinogen, limited human data are available:
82 * Probable Human Carcinogen, sufficient evidence of cmrcinogenicity in animals with inadequate or lack of evidence in humans
C « Possible Human Carcinogen, limited evidence from animal studies in the absence of human studies- and
D - Noi classified as to human cananogenicHy, inadequate or-no evidence.
(B) Unccnamty factors presented are the product* of specific uncertainty factors and modifying factors. Uncertainty factors used to
develop reference doses generally consist of multiples of 10. with each factor representing a specific area of uncertainty in the
data available, The standard uncertainty factors include:
- a 10-fold factor to account for the variation in sensitivity among the members of the human population;
- a 10-fold factor to account for the uncertainty in extrapolating animal data to the case of humans;
- a tO-fold factor to account for the uncertainty in extrapolating from less-than-chronic NOAELs to chronic NOAELs- and
- a 10-fold factor to account for the uncertainty in extrapolating from LOAELs to NOAELs
Modifying factors are applied at the discretion of the RfD reviewer to cover other uncertainties in the data and range from 1 to 10 '
( £££!! Of0an "£**?£!?* 5 ^ WBan/etfect mosl """fr*«° «» *•"** «PO«u». RfDs are based on toxic effects in the
target organ or cntical effects. If an RfD is based on a study in which a target organ or critical effect was not identified the
organ/effect listed is one known to be affected by the chemical.
W>,?«?OCef slope^ctor for benzoWpyrene w»« used to evaluate carcinogenic PAHs. along with the toxic equivalency factor
'U< ""* " f°"°WS: banz(a)anthra°8ne- °'1; benzo{b)fluoranthene. 0.1: benzoMfluoranthene. 0.01;
NOTE
IRIS « Integrated Risk Information System - USEPA,1997a.
— -Ho information available,
CNS * Central Nervous System.
DACA31-95-D-0083
TERC18-10
March 6, 1998
Human Health Risk-based Remediation Goals
Areas Requiring Environmental Evaluation t and 31
Vint Hill Farms Station
-------
The equation used to calculate risk-based remediation goals for chemicals exhibitinq carcinoaenic effort*
using the combined child/adult exposure parameters based on USEPA (1991), is as foHows ^
C = TR * ATe * 36S days / year
EF * IFA * SF0 * 10~6 kg/mg
where:
GI = chemical concentration in surface soil (mg/kg),
TR = target excess individual lifetime cancer risk (1x10*),
ATc = averaging time for carcinogenic effects (70 years),
EF = exposure frequency (350 days/year),
|f A = adjusted integrated factor (see below) (114.3 rng-year/kg-day), and
SF° = oral cancer slope factor [(mg/kg-day)'1] (see Table 1).
°hild/adult resident exposure parameters used to calculate carcinogenic risk-based
goals for incidental ingestion of surface soil incorporate an age-adjusted factor which
™ r *F Inlegf^ e*P°sure from birt* until age 30 by combining contact rates, body weights, and
cTjLSd ^fr f°r b°th Ch"dren and y°ung adults (USEPA 1997b>- ™e age-adjusted factor was
calculated as follows, using exposure parameters from USEPA (1 991 ):
EDc * IRc i rgOtot-gOe; * IR,
BWc BWa
where:
IFA = age-adjusted integrated factor (mg-year/kg-day),
EDc = child's exposure duration (6 years),
IRc = child's soil ingestion rate (200 mg/day),
BWC = child's body weight (15 kg),
ED,,,, = total exposure duration (30 years),
IRi = adult's soil ingestion rate (100 mg/day), and
BW. = adult's body weight (70 kg).
The equation used to calculate risk-based remediation goals for chemicals exhibiting noncarcinogenic
effects, using the child exposure parameters obtained from USEPA (1 991 ), is as follows:
= THI * BW * ATne * 365 days / year
EF* ED* (1/RfDo) * 10-6 kg/mg* IRSOII
TERC?fl-1n~ 3 Human Health Risk^jased Remodiation Goals
R < QQQ Areas R^u'ring Environmental Evaluation 4 and 31
6,1998 ^ Hj|| Farms
-------
where:
C, = chemical concentration in soil (mg/kg),
THI = target hazard index (1),
BW = body weight (15 kg), %
AT^ = averaging time for noncarcinogenic effects (6 years),
EF = exposure frequency (350 days/year),
ED s exposure duration (6 years),
RfD0 = oral chronic reference dose (mg/kg-day) (see Table 1), and
IRM4 = soil ingestion rate (200 mg/day).
Summary of Risk-Based Remediation Goals
Risk-based remediation goals for AREEs 4 and 31 were calculated for selected chemicals in surface soil
Specifically, risk-based remediation goals were calculated for all chemicals associated with chemical-specific
risks greater than or equal to 1x10* or chemicals contributing to a HI greater than or equal to 1 for a specific
target organ for the incidental ingestion exposure pathway. Risk-based remediation goals were not
calculated for inorganic compounds that were statistically determined to be within background levels. Risk-
based remediation goals for all selected chemicals in surface soil were developed based on conservative
child/adult resident receptors for carcinogens and child resident receptors for noncarcinogens. Risk-based
remediation goals for surface soil are presented in Table 2.
Based on a review of the chemicals and pathways evaluated in the risk assessment risk-based remediation
goals for surface soil were calculated for lead detected at AREE 4; and benzo(a)anthracene
benzo(a)pyrene, benzo(b)fiuoranthene, benzo(k)fluoranthene, indeno(1,2,3-c,d)pyrene, and lead detected at
AREE 31. USEPA's residential soil screening level for lead was developed using the Integrated Exposure
Uptake Biokinetic (IEUBK) model (USEPA, 1994) and is based on residential exposures by the most
sensitive members of the population (i.e., young children). Since a risk-based remediation goal cannot be
calculated for lead due to a lack of available quantitative carcinogenic and noncarcinogenic toxicity criteria
the 400 mg/kg residential soil screening level for lead is presented in Table 2 as the remediation goal for lead
in surface soil,
References
U.S. Environmental Protection Agency (USEPA). 1991. Risk Assessment Guidance for Superfund.
Volume 1: Human Health Evaluation Manual Supplemental Guidance. Standard Default Exposure
Factors. Interim Final. Washington, D.C. OSWER Directive 9285.6-03. March 25,1991.
U.S. Environmental Protection Agency (USEPA). 1994. Revised Interim Soil Lead Guidance for CERCLA
Sites and RCRA Corrective Action Facilities. Memorandum to Regional Administrators from Elliot P.
Laws, Assistant Administrator. Solid Waste and Emergency Response, OSWER Directive #9355 4-
12. EPA/540/F-94/043.
U,S« Environmental Protection Agency (USEPA). 1997a. Integrated Resource Information System (IRIS)
Environmental Criteria and Assessment Office, Cincinnati, Ohio.
U.S. Environmental Protection Agency (USEPA). 1997b. Risk-Based Concentration Table October 22
1997.
~^ 4 Human Health Risk-based Remediation Goals
ArBas Requinno Environmental Evaluation 4 and 31
»ju, c «eoo
March 6. 1898 Vm{ Hj|| Fam& stfltjon
-------
TABLE 2
REMEDIATION GOALS FOR CHEMICALS IN SURFACE SOIL (a)
T_oxlcltxjCriterion
amical
Carcinogenic
Noncarcinogenlc
(mg/kg-day)
Carcinogenic (b)
EE4
Resident Ingestion
Lead _
EE31
Resident Ingestion
Benzo(a)anthracene 7.3E-01
Benzo{a)pyrene 7.3E+00
Benzo(b)fluoranthene 7.3E-01
Benzo(k)fluoranthene 7.3E-02
lndeno(1,2,3-c,d)py'rene 7.3E-01
Lead _
0.87
0.087
0.87
8.7
0.87
Selected Remediation
Goal
Noncarcinogenlc (c) (mg/kg) (d)
400 (e)
0.87
0.087
0.87
8.7
0.87
400 (e)
Remediation goals were calculated for predominant chemicals (i.e., chemicals with risks exceeding 1x10"* or
chemicals contributing to a HI greater than or equal to 1 for a specific target organ) for the incidental ingestion
pathways associated with a total excess lifetime cancer risk exceeding 1 x1 V4 or a HI greater than or equal to 1.
The calculated remediation goals for carcinogenic chemicals were based on a target risk level of IxlO^ and were
calculated using combined child/adult exposure parameters.
The calculated remediation goals for noncarcinogenic chemicals were calculated using child resident exposure
parameters and were based on a hazard quotient of 1.
i The selected remediation goal represents the lower of the calculated carcinogenic and noncarcinogenic
remediation goals.
) The selected remediation goal is USEPA's residential soil screening level for lead (USEPA, 1994).
DACA31-95-D-0083
TERC18-10 '
March 6,1998
Human .Health Risk-based Remediation Goals
Areas Requiring Environmental Evaiuation 4 and 31
Vint Hill Farms Station
-------
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ECOLOGICALLY-BASED CLEANUP LEVELS
AREAS REQUIRING ENVIRONMENTAL EVALUATION (AREEs) 2, 4, AND 31
VINT HILL FARMS STATION (VHFS)
Results of the Ecological Risk Assessment (ERA) conducted as part of the Phase II Reuse Area
Remedial Investigation (Rl) at VHFS (USAGE, 1998) indicate the potential for adverse effects to ecological
resources at several on-site locations. Surface soils at AREEs 2, 4, and 31 were identified as having the
greatest potential to adversely affect ecological resources and were selected for remediation The followinq
ecological receptors were identified as having the greatest potential to be adversely affected in each of these
• AREE 2 (Sewage Treatment Plant) •
Terrestrial plants from the presence of mercury in surface soil;
Earthworms from the presence of mercury in surface soil; and
Robins and shrews from the presence of mercury in surface soil.
• AREE 4 (Auto Craft Shop)
Terrestrial plants from the presence of lead, selenium, and zinc in surface soil; and
Robins and shrews from the presence of mercury in surface soil.
• AREE 31 (Construction Debris Pile #1)
Terrestrial plants from the presence of copper, lead, and selenium in surface soil;
Earthworms from the presence of benzo(a)pyrene and copper in surface soil; and
Robins and shrews from the presence of mercury in surface soil.
The objective of this document is to identify the reduction in chemical concentrations necessary to be
protective of these ecological resources. Because of the conservative nature of the toxicological values and
exposure estimates, cleanup levels were derived based on an EEQ1 of 10. The following sections derive
cleanup levels for each of these areas based on the ecological resources at risk.
AREE 2 (Sewage Treatment Plant)
Terrestrial Plants '
Results of the ERA indicate the potential for adverse effects to terrestrial plants from the presence of
mercury in surface soil at AREE 2. A literature-based toxicity value of 0.3 mg/kg, derived by Will and Suter
(1995a) and used in the ERA to evaluate the potential for adverse effects to terrestrial plants, was used to
derive the cleanup level for mercury in surface soil. Using this toxicity value and a target EEQ of 10 the
cleanup level for mercury in surface soil for terrestrial plants at AREE 2 is 3 mg/kg.
1The Environmental Effects Quotient (EEQ) is the ratio of the estimated exposure concentration/dose for
the chemical of concern and the toxicity reference value (TRV) for the ecological receptor of concern.
DACA31-95-D-0083\ i Ecologically-based Cleanup Levels
TERC18-10 Areas Requiring Environmental Evaluation 2. 4; and 31
March 6. 1998 Vint Hill Farms Station
-------
Egrthworms
Results of the ERA indicate the potential for adverse effects to earthworms from the presence of
mercury in surface soil at AREE 2. A literature-based toxicrty value of 0.1 mg/kg, derived by Will and Suter
(1995b) and used in the ERA to evaluate the potential for adverse effects to earthworms, was used to derive
the cleanup level for mercury in surface soil. Using this toxicity value and a target EEQ of 10, the cleanup
level for mercury in surface soil for earthworms at AREE 2 is 1 mg/kg.
Terrestrial Wildlife
Results of the ERA indicate the potential for adverse effects to robins and shrews from the presence
of mercury in surface soil at AREE 2. Attachment A outlines the screening model and input parameters used
in the ERA to estimate the potential for adverse effects to robins and shrews. Assumptions in this model
were designed to provide a highly conservative estimate of the potential for adverse effects to robins and
shrews. In the model, it is assumed that robins and shrews would be exposed to the estimated average
mercury concentrations detected at AREE 2 (2.79 mg/kg). However, as discussed in the Rl, samples were
biased to areas of likely contamination, and samples from these areas are likely to over-estimate actual
levels of contamination throughout the facility. Further, the highest mercury concentrations were detected
within a very localized area of AREE 2. The area of mercury contamination in surface soil at AREE 2 is
immediately downgradient of the former sludge pile, and is estimated to be approximately 75 feet by 25 feet
in size. Accordingly, robins and shrews are likely to be exposed to mercury in only a limited proportion of
their total foraging area and, because of the biased sampling methodology, using an average of the mercury
concentrations detected in surface soil at AREE 2 will likely over-estimate the potential for exposure and
adverse effects.
Cleanup levels were determined by backcalculating through the risk model used in the ERA Two
approaches were used to develop cleanup levels for robins and shrews. The first approach assumes the
foraging range of robins and shrews falls entirely in the contaminated areas of AREE 2. This approach is
consistent with that used in the ERA and simply requires determining, by backcalculating through the
equations presented in Attachment A, an average exposure concentration which is equal to 10 times the
toxicity value2 used in the ERA (i.e., an EEQ of 10). However, this approach is likely to over-estimate risks
because it assumes the average AREE 2 exposure concentration, estimated by averaging the concentrations
of chemical detected at surface soil sample locations, is an accurate indicator of chemical concentrations
throughout the receptor's foraging range. The second approach applies a spatial factor to adjust for the area
of actual contamination. This latter approach is expected to provide a more realistic estimate of exposure.
The spatial factor used for the second approach was derived by first estimating the total area over
which a robin or shrew is likely to forage. Pitts (1984) estimated an average territory size of 0.42 hectares
(equal to 45,208 square feet) for robins on a college campus in Tennessee. Meanwhile, Buckner (1966)
estimated an average territory size of 0.39 hectares (equal to 41,978 square feet) for shrews. Cleanup levels
for AREE 2 were calculated assuming robins and shrews would not be exposed to mercury at any location
outside of AREE 2. This assumption was made because mercury was not detected at any other locations
within the foraging range of these species.
The total area of potential mercury contamination to which a robin or shrew foraging at AREE 2 could
be exposed was estimated to be 1,875 square feet by assuming a maximum area of contamination in AREE
2 of 75 feet by 25 feet. The proportion of the total foraging area at which a robin or shrew associated with
AREE 2 could be exposed to mercury was then estimated by dividing the estimated total area contaminated
with mercury by each species' estimated territory size. Using this approach, a proportion of 0.041 was
2 The toxicity values used in the ERA are based on no observed adverse effects levels (NOAELs) derived by Oak
Ridge National Laboratory (ORNL, 1996).
DACA31-95-D-0083 ~~ 2 ' Ecologically-based Cleanup Levels
TERC18-10 Areas ftequiring Environmental Evaluation 2, 4, and 31
March 6.1998 V,m Hiii Farms Station
-------
estimated for robin and a proportion of 0.045 was estimated for shrew. This proportion was then used ** *
multiplier in equations (2) and (5) of Attachment A. as a
Cleanup levels derived using the approaches described above are presented in Table 1 The
approach which accounts for the limited distribution of mercury in the territorial range of robins and shrew*
results in higher cleanup levels. However, these cleanup levels are expected to be more realistic and are
.recommended for use as the final cleanup levels. Consistent with the ERA. cleanup levels were also derived
?f*£ Jn0rgarl£and °r?anic mercury (metny'mercury). Although it is likely only a proportion of the mercury
detected m surface soil is present in the organic form, it is recommended that the more conservative
methylmercury cleanup level be selected as the cleanup level for AREE 2.
AREE 4 (Auto Craft Shop)
Terrestrial Plants
Results of the ERA indicate the potential for adverse effects to terrestrial plants from the presence of
ieag\ selenium, and zinc in surface soil. Literature-based toxicity values for lead, selenium, and zinc of 50
mg/kg, 1 mg/kg, and 50 mg/kg. respectively, derived by Will and Suter (1995a) were used in the ERA to
evaluate the potential for adverse effects to terrestrial plants. Using these toxicity values and a target EEQ of
10, the cleanup levels for lead, selenium, and zinc in surface soil for terrestrial plants at AREE 4 are 500
mg/kg, 10 mg/kg, and 500 mg/kg, respectively.
Terrestrial Wildlife
Results of the ERA indicate the potential for adverse effects to robins and shrews from the presence
of mercury in surface soil at AREE 4. Attachment A outlines the screening model and input parameters used
in the ERA to estimate the potential for adverse effects to robins and shrews. Assumptions in this model
were designed to provide, a highly conservative estimate of the potential for adverse effects to robins and
shrews. In the model, it is assumed that robins and shrews would be exposed to the average of the mercury
concentrations detected at AREE 4 (0.167 mg/kg). However/as discussed in the Rl, the elevated mercury
concentrations were detected in very localized areas at AREE 4. The areas of mercury contamination driving
the nsk to terrestrial wildlife are comprised of the runoff areas from the storm sewer discharge the former
hydraulic lift, and the wash rack discharge. Each of the areas of mercury contamination are estimated to be
no greater than 15 feet by 15 feet in size. Accordingly, robins and shrews are likely to be exposed to this
chemical in only a very limited proportion of their total foraging area, and the use of an average AREE 4
mercury concentration will likely over-estimate the potential for exposure and adverse effects to robins and
shrews.
Cleanup levels for mercury were calculated for AREE 4 using the same methods described earlier to
denve cleanup levels for mercury at AREE 2. The contaminated proportion of the total territory size was
estimated to be 0.015 for robins and 0.016 for shrews assuming the contaminated area of AREE 4 is 675
square feet in size. Only AREE 4 was factored into the calculation because mercury was not detected at any
other locations within the foraging range of these species. The cleanup levels derived for mercury are
summarized in Table 1. It is recommended that the cleanup level derived using the approach which
accounts for the spatial distribution of mercury be used as the cleanup level for AREE 4. Although it is likely
only a proportion of the mercury detected in surface soil is present in the organic form, it is recommended
that the more conservative methylmercury cleanup level be selected as the cleanup level for AREE 4
3 Ecologically-based Oeanup Levels
.«
-------
HI
?> oo is
-*i
-------
AREE 31 (Construction Debris Pile #1)
Terrestrial Plants
Results of the ERA indicate the potential for adverse effects to terrestrial plants from the presence of
^iSL6 ™ selemum in surface soil. Literature-based toxicfty values for copper, lead, and selenium of
100 rng/kg 50 mg/kg, and 1 mg/kg. respectively, derived by Will and Suter (1995a) were used in the ERA to
evaluate he potential for adverse effects to terrestrial plants. Using these toxicity values and a target EEQ of
n'nn t±an^neVe'£ f°f 'JET' 'ead' 8nd Selenium in SUrface soil for terrestrial P|af*s at AREE 31 a°e
1,000 mg/kg, 500 mg/kg, and 10 mg/kg, respectively.
Earthworm^
Results of the ERA indicate the potential for adverse effects to earthworms from the presence of
™/£ne H^n00^ in SUrfaCe ?"• Lterature-bas*d toxicity values for benzo(a)pyrene and copper
a^ w,f H c"? F;^!^^' derived by Acha2i et aL (1995' as cited in van Brummelen et al
and Wll and Suter (1995b) were used in the ERA to evaluate the potential for adverse effects to
earthworms. Using these toxicity values and a target EEQ of 10, the cleanup levels for benzo(a)pyrene and
copper in surface -soil for earthworms at AREE 31 are 25.7 mg/kg and 500 mg/kg, respectively.
Terrestrial Wildlife
Results of the ERA indicate the potential for adverse effects to robins and shrews from the presence
of mercury .n surface soil at AREE 31. Attachment A outlines the screening model and input parameters
used in the ERA to estimate the potential for adverse effects to robins and shrews. Assumptions in this
model were designed to provide a highly conservative estimate of the potential for adverse effects to robins
and shrews. In the model, it is assumed that robins and shrews would be exposed to the averaqe of the
mercury concentrations detected at AREE 31 (0.198 mg/kg). However, as discussed in the Rl elevated
mercury concentrations were detected in a very localized area of AREE 31. The area of mercurv
contamination in surface soil that is driving the risk to terrestrial wildlife is the northeastern portion of the
debns pile, which is estimated to be no greater than 15 feet by 50 feet in size. Accordingly, robins and
shrews are likely to be exposed to this chemical in only a very limited proportion of their total foraging area
and the use of an average AREE 31 mercury concentration will likely overestimate the potential for exposure
and adverse effects to robins and shrews.
Cleanup levels for mercury were calculated for AREE 31 using the methods described earlier to
derive cleanup levels for mercury at AREEs 2 and 4. The contaminated proportion of the total territory size
was estimated to be 0.017 for robins and 0.018 for shrews assuming the contaminated area of AREE 31 is
750 square feet in size. Only AREE 31 was factored into the calculation because mercury was not detected
at any other locations within the foraging range of these species. The cleanup levels derived for mercury are
summarized in Table 1. It is recommended that the cleanup level derived using the approach which
accounts for the spatial distribution of mercury be used as the cleanup level for AREE 31 Although it is likely
only a proportion of the mercury detected in surface soil is present in the organic form, it is recommended
that the more conservative methylmercury cleanup level be selected as the cleanup level for AREE 31.
Summary of Cleanup Levels
Table 2 Presents the cleanup levels for chemicals of significant ecological concern in surface soil for
AREEs 2. 4, and 31. For chemicals that pose potential adverse ecological effects to more than one receptor
the cleanup level presented in Table 2 is for the most sensitive receptor. It should be noted that the
recommended cleanup level derived for mercury at AREEs 4 (0.53 mg/kg) and 31 (0.48 mg/kg} are higher
than the maximum detected concentrations in these AREEs (i.e., 0.393 mg/kg at AREE 4 and 0 208 mg/kg
Ecologically-basedCteanupLeve.*
., V!?";" Areas Requiring Environmental Evaluation 2. 4, and 31
March 6, 1998 ^ m Fafms
-------
Table 2
Cleanup Levels for Chemicals In Surface Soil
AREE2
Mercury
0.192
AREE4
Lead
Mercury
Selenium
Zinc
500
0.534
10
500
AREE 31
Benzo.(a)pyrene
Copper
Lead
Mercury
Selenium
25.7
500
500
0.48
10
DACA31-95-CMW83
TERC18-10
March 6,1998
Ecologically-based Cleanup Levels
Areas Requiring Environmental Evaluation 2,4, and 31
Vint Hill Farms Station
-------
at AREE 31), indicating that remediation of mercun/ at these AREEs may not be required when its areal
consiG6r&cf.
References 4
Achazi, R.K., Chroszcz, G., Duker, C., Henneken, M., Rothe, B., Schaub, K., and Steudel I 1995 The Effect
of Ruoranthene (Fla), Benzo[a]pyrene (BaP) and Cadmium (Cd) Upon Survival Rate and Life Cycle
Parameters of Two Terrestrial Annelids in Laboratory Test Systems. Newsl. Enchytraeidae. 4:7-14.
Buckner, C.H. 1966. Populations and Ecological Relationships of Shrews in Tamarack Boas of
Southeastern Manitoba. J. Mammal. 47:181-194.
Oak Ridge National Laboratory (ORNL). 1996. Screening Benchmarks for Ecological Risk Assessment
Version 1.6. Environmental Sciences and Health Sciences Research Divisions Oak Ridqe National
Laboratory. Oak Ridge, TN.
Pitts, T.D. 1984. Description of American Robin Territories in Northwest Tennessee. Migrant 55:1-6.
U.S. Army Corps of Engineers (USAGE). 1998. Remedial Investigation. Vint Hill Farms Station Phase II
Reuse Area Remedial Investigation. Draft Document Prepared by ICF Kaiser Engineers Inc
Edgewood, Maryland. January, 1998. ' "
van Brummelen, T.C., van Gestel, CAM., and Verweij. RA 1996. Long-term Toxicity of Five Polycyclic
Aromatic Hydrocarbons for the Terrestrial Isopods Oniscus asellus and Porcellio scaber Environ
Toxicol. Chem. 15(7):1199-1210. '
Will. M.E. and Suter, G.W., II. 1995a. Toxicological Benchmarks for Screening Potential Contaminants of
Concern for Effects on Terrestrial Plants. Rev. ed. Oak Ridge National Laboratory Oak Ridae TN
ES/ER/TM-85/R1. '
Will, M.E. and Suter, G.W., II. 1995b. Toxicological Benchmarks for Screening Potential Contaminants of
Concern for Effects on Soil and Litter Invertebrates and Heterotrophic Process Oak Ridge National
Laboratory, Oak Ridge, TN. ES/ER/TM-126.
DACA31-95-D-0083 7 Ecologically-based Cleanup Levels
TCRC18-10 Areas Requiring Environmental Evaluation 2,4. and 31
March 6. 1998 . Vmi H||, Farms station
-------
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ATTACHMENT A
ESTIMATION OF ROBIN AND SHREW EXPOSURE TO CHEMICALS
FOR THE DERIVATION OF CLEANUP LEVELS
The following sections present the methods used to calculate the potential ingestion of chemicals bv
robins and shrews from the ingestion of food (i.e., earthworms) and surface soil. The equations aiven b^iow
were derived based on equations presented by USEPA (1989). Table A-i presents specific exposure
parameter values used in these equations. c^u^ure
Total Dose
The total dietary exposure levels for robins and shrews to chemicals was determined using the
following equation: y
Dosetotai - Dosewom + Dosesoa
(1)
where:
= amount of chemical ingested per day via ingestion of earthworms (in mg/kg b'w-d
use equations 2, 3, and 4 to calculate); and
= amount of chemical ingested per day from soil (in mg/kg bw-d, use equation 5 to
calculate).
Dose From Earthworms
The following equation was used to calculate the dose of chemicals that robins and shrews would be
expected to obtain from the ingestion of earthworms:
DoSSwom = Fl * Cdiet
(2)
where:
FI = food ingestion rate (kg/kg bw-d); and
C«« ; - estimated chemical concentration in diet (in mg/kg. use equation 3 to calculate).
The estimated dietary concentration (C^ was calculated using the following equation:
Ctf/e/=Pe*Ce
(3)
where:
P« = proportion of diet consisting of earthworms (unitless); and
C« = estimated concentration of chemical in earthworms (in mg/kg, use equation 4 to
calculate).
DACA31-95-D-0083 A-1 Ecoloflicaily-based Cleanup Levels
'
. Areas Requiring Environmental Evaluation 2. 4, and 31
March 6. 1998 Vint Hi|, Famis station
-------
Table A-1
Summary of Exposure Parameters Used In the Robin and Shrew Food Ingestion Models
Food ingestion rate (Fl; kg/kg bw-d)
1.52 (a)
0.62 (g)
Proportion of diet consisting of earthworms (Pe; unitless)
0.18(b,c)
0.314 (h)
Bioconcentration factor for chemical
in earthworms (BCF; unitless)
inorganic mercury = 0.96 (d)
methylmercury = 27 (e)
inorganic mercury = 0.96 (d)
methylmercury = 27 (e)
Soit Ingestion rate (SI; kg/kg bw-d)
=-.
(a) Hazelton et al. (1984) as cited in USEPA (1993).
(b) Wheelwright (1986) as cited in USEPA (1993).
(c) Howell (1942) as cited in USEPA (1993).
(d) Beyer and Stafford (1993).
(e)Eisler(1987).
(f) Beyer el al. (1994).
(g) Morrison et al. (1957) as cited in USEPA (1993).
(h) Whilaker and Ferraro (1963) as cited in USEPA (1993).
0.158 (f)
0.058 (f)
DACA31-95-D-0083
TERC18-10
March 6,1998
A-2 . Ecologically-based Cleanup Levels
Areas Requiring Environmental Evaluation 2,4, and 31
Vint Hill Farms Station
-------
'> ** fresh ™
^ermined using the
where:
Ce = Csoil * BCF
(4)
average concentration of chemical detected in surface soil (mg/kq)- and
bloconcentration factor for chemical in earthworms (unitless).
Dose From Soil
°< *«*"• «- «<*"
would be
Dosesoii = SI *
where:
S'
Mil
soil ingestion rate (kg/kg bw-d); and
average chemical concentration in surface soil (mg/kg).
References
f d EVa'Uati°n °f
in Earthworms and in Soils
' E"
S' 1994' Estimates of Soi""9estion by Wildlife. J. Wildl. Manage.
A Synoptic Review Contaminant
Hazelton P.K., Robel, R.J., and Dayton, A.D. 1984. Preferences and influences of Paired Food Items on
and Gray Catbirds V>™*™* oarctinensis).
R°bin (TurdUS mi9^oriuS). Am. Mild. Nat.
Morrison P.R., Pierce, M., and Ryser, FA. 1957. Food Consumption and Body Weight in the Masked and
Short-taded Shrews (genus Btarina) in Kansas, .owa, and Missouri. Ann. cLegie Mus 51 157
. 1989. Risk Assessment Guidance for Superfund. Volume
Health Evaluation Manual. Part A. Interim Final. EPA/540/1-89/002. December, 1989.
U.S. Environmental Protection Agency (USEPA). 1993. Wildlife Exposure Factors Handbook. Volume I of
II. Office of Research and Development, Washington, D.C. EPA/630/R-93/187a.
DACA31-95-D-0083
TERC18-10
March 6 1998
A-3
MO
g , .
. Ecologically-based Cleanup Levels
Areas Requiring Environmental Evaluation 2, 4, and 31
Vint Hill Farms Station
-------
Wheelwright N.T. 1986. The Diet of American Robins: An Analysis of U.S. Biological Survey Records. Auk
i UO. / IU"/fcO.
Whitaker. J.O. and Ferraro. M.G. 1963. Summer Food of 220 Short-tailed Shrews From Ithaca, New York
J. Mammal. 44:419.
Ecologically-based Cleanup Levels
MaVThfi "noon Areas Requiring Environmental Evaluation 2. 4, and 31
March 6. 1998 Vml m Fafms statjon
-------
ATTACHMENT 3
PUBLIC NOTICE
-------
-------
The United States Army
at Vint Hill Farms Station, Virginia
&. Invites Public
m Comment
gy ON A PROPOSED
y ENVIHONMEHTALCLEANUP
Concerning Four Areas
Requiring Environmental
Evaluation: 2,4,28-5, & 31
Please Come To Our
. pllRLIC MEETING «
• Thursday, April 9,1998 • 7:00 p.m.'
4 Warrenton Middle School Auditorium •
244 Waterloo Street • Werrenlon. VA
(•Sign Language Interpreter will be present) -
PURPOSE TO DISCUSS AND PRESENT THE REME-
DIAL ALTERNATIVES FOR THE SITES IDENTIFIED
ABOVE,
The U S Army in consultation with the U S Environmen-
tal Protection Agency IUSEPA) Region III and the Virginia
Department ol Environmental Quality IVDEO). nvnes pub-
lic comment on its Proposed Plan for remedietlno. con-
laminated soil al Ihe lolowmg Areas Requiring Environ-
mental Evaluation (AREEs) on Vint Hill Farms Station
IVHFSI Virginia AREE 2- Sewage Treatment Plant: AREE
4 - Auio Craft Shop. AREE 2B-5 - Former Service Station
Abandoned underground Slorage Tanks: and AREE 31 -
Construction Debns Pi* n. Belore selecting a final rem-
edy. VHFS will consider all wnllen end oral commenls
received dunng Ine public comment penod.
KMUCrawlEHTPEHOOwHah
h..ln. Tlttlf.a.v- M.rch «. MM. '.
T~< fin... FHrt.y ApHI 24. 1MB.
WRITTEN COMMENTS UAY BE SUBMITTED TO THE
FOLLOWING ADDRESS: I
Ktvln Bell. Public AHmln Officer,
Public Atitln omct IBIdg. 2500)
l'/nf Htll e*nrtm Star/on. •
Wtrremon. VA 10tB7-S001
BACKGROUND
VHFS Is part of Ine U.S Army Communications - Elec-
tronics Command (CECOM) and. while active, pnmanly
lunctiorwd as an Army Installation anoaged tn communi-
cations Meltigence, VHFS is located appio.lmalely 40
miles southwest 01 Washmglon. D.C.. in Fauquier County.
Virginia The installalion occupies approximately 701
acres ol land near me town ol warrantor!. Virginia Ap-
pro.imalely ISO acres ol me installation are improved
grounds in me soutfiem portion ol the property used lor i
intlustnet operations, administration buildings, and rest- j
danttai housing Approximately 94 acres on Ihe eastern
portion c-l the properly are mature hardwood forest, and
the majonly of the remaning 457 unimproved and semi-
improved acres in Ihe northern ponton of the prooeny are
used tor stationary and moMe antenna operation sues.
The lacilily was designated lor closure in March. 1993.
under ihe Base Realignment and Closure (BRACl Act
PROPOSAL
VHFS evaluated two remedial alternatives to address sod
contaminalion al AREEs 2. 4, 2S-S. and 31.
ALTERNATIVE 1: No Artlon; and
ALTERNATIVE 2: Soil Removal.
Based on avadabie information. VHFS prefers Alleme- i
live 2 which includes eicavation ol contaminated sort and
oil-site disposal al a permitted facility. This remedial al-
ternative is a permanent solution thai otters tong-term
elltcuveness since me conlamlnated soil Is removed 10 •
cleanup levels and iiansported oft site tor proper disposal.
Since Ihe amount ol soil requiring remedialion is rela- |
lively small (approumalety 40O cubic yards), it was not |
practice! to consider active treat/tier* or containment op- i
IKXIS in terms ol cost-ottectrveness and imptemenlaoUity.
The e«cavat«m and disposal of contamnaltrj soil would
be done in accordance wim letKral ana Cornmonvreallh
ol Virginia solid and hazardous waste regulations
FOR MOHE fWOnWATOrV
You can review the Proposed Plan and related lechnical
documents al Ihe Information Repository al the knowing
location:
Feuouler County Ubmry, Wanemon Branch •
Reference Section
11 wncheflerSTreer, Warrenton. VA22186
Uaynr M-w: 10 a.m. -« p m.
andTh-Sat9a.m..5p.m andSun tp.m.-5pm.
, Phone (HO) 347-8750
I
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National Technical Information Service
Springfield, VA 22161
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information — then organizes, maintains, and disseminates that
information in a variety of formats — from microfiche to online services.
The NTIS collection of nearly 3 million titles includes reports describing
research conducted or sponsored by federal agencies and their
contractors; statistical and business information; U.S. military
publications; multimedia/training products; computer software and
electronic databases developed by federal agencies; training tools; and
technical reports prepared by research organizations worldwide.
Approximately 100,000 new titles are added and indexed into the NTIS
collection annually.
For more information about NTIS products and services, call NTIS
at 1-800-553-NT1S (6847) or (703) 605-6000 and request the free
NTIS Products Catalog, PR-827LPG, or visit the NTIS Web site
http://www.ntis.gov.
NTIS
Your indispensable resource for government-sponsored
information—U.S. and worldwide
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