PB98-963910
EPA 541-R98-066
October 1998
EPA Supei fund
Record of Decision:
Langley AFB/NASA Langley Center
Area E Warehouse OU
Hampton, VA
9/28/1998
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RECORD OF DECISION
NASA LANGLEY RESEARCH CENTER
AREA E WAREHOUSE OU
September 1998
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RECORD OF DECISION
NASA LANGLEY RESEARCH CENTER
DECLARATION
SITE NAME AND LOCATION
NASA Langley Research Center (NASA LaRC)
Area E Warehouse Operable Unit
Hampton. Virginia
STATEMENT OF BASIS AND PURPOSE
This Record of Decision (ROD) presents the selected remedial action for the Area E Warehouse Operable Unit
(OU) at the NASA Langley Research Center (LaRC) in Hampton, Virginia (the "Site"), chosen in accordance
with the Comprehensive Environmental Response. Compensation, and Liability Act (CERCLA) of 1980. as
amended, 42 U.S.C. §9601 et seq. and. to the extent practicable, the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP), 40 C.F.R. Pan 300. This decision is based on the Administrative Record for
this Site.
The Virginia Department of Environmental Quality (VDEQ) concurs with the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this OU. if not addressed by implementing the
response actions selected in this ROD, may present an imminent and substantial endangerment to public health.
welfare, or the environment.
DESCRIPTION OF THE SELECTED REMEDY
The Area E Warehouse OU cleanup is part of a comprehensive environmental investigation and cleanup currently
being performed at the NASA LaRC under the CERCLA program. NASA LaRC is currently addressing five
OUs under its environmental remediation program. The remaining four OUs will be addressed in future RODs.
This action addresses the principle threat at the OU by imposing land use restrictions that will prevent any non-
industrial activities to take place on the OU.
The selected remedy is the implementation of institutional controls, which include:
1) the prohibition of use of the property for purposes other than industrial (e.g., residential, child care
or recreational use);
2) inputting these restrictions in the NASA LaRC Master Plan;
3) within 90 days of ROD signature. NASA shall produce a survey plat prepared by a professional land
surveyor registered by the Commonwealth of Virginia indicating the location and dimensions of the Area
E Warehouse Operable Unit and the extent of the soil contamination. The plat shall contain a note.
prominently displayed, which states the owner's future obligation to restrict the land use of the property.
The plat shall be submitted to the local recording authority;
4) NASA shall incorporate these restrictions and supply a copy of the plat into any real property
documents necessary for transferring ownership from NASA, in the unlikely event that NASA sells the
property. The real property document would also include a discussion of the National Priorities List
(NPL) status of this Site, as well as a description of the soil contamination;
5) The NASA LaRC Environmental Engineering Office Head will certify to USEPA on an annual basis
that there have been no violations of these prohibitions. If a violation has occurred, a description of the
violation and corrective actions to be taken will be provided.
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DECLARATION OF STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the environment, complies with federal and State
requirements that are legally applicable or relevant and appropriate to the remedial action, and is cost-effective.
The remedy utilizes permanent solutions and alternative treatment technologies to the maximum extent practicable
for this OU.
Because this remedy may result in hazardous substances remaining onsite, a review will be conducted within 5
years after the commencement of the remedial action to ensure that the remedy continues to provide adequate
protection of human health and the environment.
Or. Jertfiiah F. Creedon Date
Director
NASA Langley Research Center
Abraham Ferdas Date
Director
Hazardous Site Cleanup Division
U.S. Environmental Protection Agency, Region III
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TABLE OF CONTENTS
SECTION PAGE
I. SITE NAME, LOCATION AND DESCRIPTION 1
II. SITE HISTORY 2
III. HIGHLIGHTS OF COMMUNITY PARTICIPATION 3
IV. SCOPE AND ROLE OF THIS REMEDIAL ACTION 4
V. SUMMARY OF SITE CHARACTERISTICS/EXTENT OF CONTAMINATION 4
VI. SUMMARY OF SITE RISKS 7
VII. DESCRIPTION OF ALTERNATIVES 9
VIII. SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 10
IX. SELECTED REMEDY 12
X. STATUTORY DETERMINATIONS 13
XI. DOCUMENTATION OF SIGNIFICANT CHANGES 14
XII. RESPONSIVENESS SUMMARY 14
XIII. REFERENCES 16
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LIST OF TABLES AND FIGURES
TABLE ~~ DESCRIPTION PAGE
1 Summary of Operable Units under CERCLA Investigation 2
2 Exposure and Intake Assumptions for Dermal Contact and Ingestion A-1
3 Area E Warehouse Hazard Index and Excess Cancer Risk, NASA A-2
Langley Research Center
4 Clean-up Soil Concentration Area E Warehouse/Surface Soil, NASA A-4
Langley Research Center
5 Screening of Soil Remedial Technologies, Area E Warehouse Site, A-5
NASA Langley Research Center
6 Summary of Alternative Screening Soil Remedial Technologies, A-11
NASA Area E Warehouse
FIGURE DESCRIPTION PAGE
1 Site Location Map IA
2 Area E Warehouse Layout IB
3 Soil Sampling Locations, NASA LaRC Site Assessment 6A
4 Soil Sampling Locations, Contamination Assessment 6B
5 Monitoring Well Locations for Area E Warehouse 1A
6 Area E Warehouse Sediment Sampling Locations 7B
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RECORD OF DECISION
NASA LANGLEY RESEARCH CENTER
AREA E WAREHOUSE OPERABLE UNIT
DECISION SUMMARY
I. SITE NAME. LOCATION. AND DESCRIPTION
NASA LaRC is a 787-acre NASA research center located in southeastern Virginia in the Hampton Roads area.
NASA LaRC is bounded by State Route 172 on die West, by Brick Kiln Creek to the North and byLangley Air
Force Base to the South and East (Figure 1). NASA LaRC together with Langley Air Force Base was proposed
to the National Priorities List (NPL) in 1993 and finalized in 1994.
The Area E Warehouse OU is located along the eastern boundary between NASA LaRC and Langley Air Force
Base. The Area E Warehouse OU is approximately 4.5 acres in size (Figure 2). The area houses several
structures which encompass approximately * of die OU. The site includes the area immediately surrounding
Buildings 1170 to 1174 as shown in Figure 2. Storm sewers located on the site discharge into a small ditch
approximately 120 feet long located immediately adjacent to the Area E Warehouse OU. The ditch discharges
into the site-wide drainage system which ultimately discharges into theTabbs Creek estuary. The distance from
the drainage ditch to Tabbs Creek is approximately 14 of a mile.
The Area E Warehouse OU serves as a storage and distribution center for all supplies and materials for the NASA
LaRC facility. The area includes mainly asphalt and gravel road surfaces and warehouse structures. Drums,
which are stored on pallets, containing raw products (lubricating oils, solvents, etc.) to be issued for use
throughout the Center, rolls of electrical conduit, and miscellaneous equipment occupy approximately 40 percent
of the warehouse area. Approximately 10 percent of the area is covered with grass.
The OU is in close proximity to Tabbs Creek and widiin die tidal zone of the Chesapeake Bay (Figure 1). Marine
wetlands are common in the surrounding area, and the Plum Tree Island National Wildlife Refuge is located
approximately four miles northeast of the OU. The northeast portion of the OU is located within the 100-year
flood plain, coinciding approximately with die 8.5-foot elevation contour.
The site is located within the Atlantic Coastal Plain physiographic province. The geology of the area, primarily
flat lying marine sediments, consists of die Norfolk Formation and the Yorfctown Formation. The uppermost soil
unit at the site consists of varying sequences of silt, clay, and silty to clayey sands belonging to the Norfolk
Formation. In the boring drilled for the Site Inspection, this unit occurs from 0 to 9 feet in depth and consists of
brown, mottled orange and gray soils. They are typically dry to moist and slightly to moderately plastic. The
underlying Yorktown Formation consists of gray silty clay and clayey silt with abundant shells and shell
fragments. It is typically wet to saturated, moderately to highly plastic and occasionally mottled. Local sand
lenses are common, as are partially indurated shelly layers (coquina). The Yorktown Formation extends to
approximately 400 feet below grade at the site.
Groundwater in the area can be found at a depth of 5 to 50 feet below the land surface. This aquifer, known as
the Columbia aquifer, is brackish and is limited to lawn and garden watering. Both the Yorktown and the
Yorktown-Eastover aquifers underlie the Columbia aquifer. The Yorktown-Eastover aquifer is confined and is
used as a source of domestic potable water.
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FIGURE 1
SITE LOCATION MAP
NASA LARC AREA E
Prepared by Ebasco Services incorporated
1A
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^
AREA E WAREHOUSE
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LEGEND
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-••"•AREA BOUNDARIES i
— — » SITE BOUNDARY j\
PROPERTY LINE ^ n , tn
ROADS -"- ° 'V0
' ' FENCES A Sco'«"m F-tti
' i BUILDINGS II
• CATCH BASIN (4
•
FIGURE 2
AREA E WAREHOUSE LAYOUT
Prepared by: Ebasco Services Inc.
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II. SITE HISTORY
This section describes the history of waste disposal, and CERCLA investigations response actions at the Site.
A. HISTORY OF WASTE DISPOSAL
The primary function of NASA LaRC is the research and development of advanced technologies for aircraft and
spacecraft. Specific studies center on instrumentation, materials fatigue, acoustics, aerodynamics, and guidance
control. In conducting its research and development mission. NASA LaRC requires many support facilities
including Underground Storage Tanks (USTs) for fuel and other raw products, power plants, wind tunnels.
laboratories and administrative buildings. All of these facilities have the potential to impact the environment
through disposal activities, transfer operations and inadvertent releases such as spills or mechanical malfunctions.
There are currently 5 Operable Units being investigated under CERCLA at NASA LaRC. They include: the
Construction Debris Landfill, the Chemical Waste Pit, Tabbs Creek. Stratum Substation and Area E Warehouse.
A brief summary of these areas is provided on Table 1. Figure 1 provides the location of these areas. The 4
remaining Operable Units will be addressed in future Records of Decision.
Table 1. Summary of Operable Units Under CERCLA Investigations
OUName
Construction Debris Landfill
Chemical Waste Pit
Tabbs Creek
Stratton Substation
Findings
Organic and inorganic
contaminants found in
groundwater. surface water,
sediment, and soil.
Chemical wastes reportedly buried
at the site.
PCB/PCT contamination in
sediments.
PCB contaminated soil.
Current Status
Draft Remedial
Investigation/Feasibility Study
(RI/FS) under regulatory review
Chemical Waste Pit was found to
be located within the boundaries of
the Construction Debris Landfill
(CDL) OU and is addressed in the
CDL RI/FS.
Final RI/FS completed.
Draft Final Focused RI/FS
currently under regulatory review.
The Area E Warehouse serves as a storage distribution center for all supplies and materials for the NASA LaRC
facility. The Area E Warehouse is used by LaRC to store raw products under cover and in original packing for
use in day-to-day operational activities and as a staging area and temporary storage for outgoing construction
wastes prior to off-site disposal. From the 1960's to 1990. a small outdoor staging area was used for the storage
of both hazardous and non-hazardous waste materials. In addition, polychlorinated biphenyl transformers were
stored within the Area E Warehouse OU. Past activities have included some on-site spills within the warehouse
area.
B.
CERCLA INVESTIGATIONS
NASA completed CERCLA Preliminary Assessment (PA) and Site Inspection (SI) Reports in 1988 and 1989.
respectively. In 1993, NASA LaRC. together with Langley Air Force Base (LAFB), was proposed for inclusion
on the National Priorities List (NPL) and finalized in 1994. A Federal Facilities Agreement (FFA) was signed by
EPA. NASA and the Virginia Department of Environmental Quality (VDEQ) in 1994. The FFA establishes a
procedural framework and schedule for implementing site cleanups at NASA LaRC (the Site).
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NASA has investigated hazardous releases at the Site in multiple investigations. Previous investigations at the
Area E Warehouse OU include a Preliminary Assessment (PA) completed in April 1988, a Site Inspection in May
1989 (Ebasco, 1989), a Site Assessment in November. 1990 (Ebasco. 1990), and a Contamination Assessment in
October 1992 (Ebasco,-1992). The Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA), as amended, mandates that the Environmental Protection Agency (USEPA) establish a docket of
federal facilities where hazardous waste has been generated, stored, treated, or disposed in the past. The PA
identified the Area E Warehouse as requiring further investigation of past waste handling activities through
completion of a Site Inspection (SI).
The SI identified the contaminants of concern at the Area E Warehouse OU as mercury, lead, manganese, and
polychlorinated biphenyls (PCBs). Because of the presence of mercury, lead, manganese, and PCBs in Area E
Warehouse soil. NASA proceeded with a Site Assessment (SA) to establish the risk posed from the contaminants
and to develop a course of action to remove the contaminants from the OU, if necessary.
Consequently, a Contamination Assessment (CA) was conducted to further delineate die extent of PCB
contamination at the OU as well as conducting a focused sediment sampling effort in a nearby drainage ditch. In
addition an Addendum to die SA was prepared in August of 1995 to clarify die data presentation in the original
SA Report.
ffl. HIGHLIGHTS OF COMMUNITY PARTICIPATION
In accordance with Sections 113 and 117 of CERCLA. 42 U.S.C. Sections 9613 and 9617, NASA, in conjunction
with EPA. issued a Proposed Plan on January 26, 1998, presenting the preferred remedial alternative for the Area
E Warehouse OU. The Proposed Plan and the supporting documentation became available for review at that time
and are among the documents which comprise the CERCLA Administrative Record for NASA LaRC.
The Administrative Record is available for review by the public at the following information repositories:
• Poquoson Public Library
800 City Hall Avenue
Poquoson. Virginia.
• • Royd L. Thompson Library
NASA LaRC
Hampton. Virginia
An announcement for an availability session, the comment period, and the availability of the Administrative
Record for the remedy for the Area E Warehouse OU was published in the Daily Press on January 25. 1998.
Additionally, the Notice of Availability was mailed to local municipal and government agencies and residents in
the vicinity of the Site.
The public comment period for the Proposed Plan was from January 26, 1998 to March 11, 1998. A public
availability session was held at the Virginia Air and Space museum in Hampton, Virginia on February 5, 1998 to
inform the public of all the remedial alternatives and to seek public comments. At this meeting, representatives
from NASA. USEPA, VDEQ, and Foster Wheeler (an environmental consultant) were available to answer
questions about conditions at the site and the remedial alternatives under consideration. Responses to the
comments received during this period are included in the Responsiveness Summary section of this ROD.
This Record of Decision presents the selected remedial action for the Area E Warehouse OU in accordance with
CERCLA and. to the extent practicable, the National Contingency Plan (NCP).
All documents considered or relied upon in reaching the remedy selection decision contained in this ROD are
included in the Administrative Record for the Site and can be reviewed at the information repositories.
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IV. «jfDPE AND ROI.F QF THIS REMEDIAL ACTION
Discrete portions of an NPL site are often managed more effectively as Operable Units. NASA has organized
work to date into five operable units. This ROD addresses the Area E Warehouse OU. The remaining Operable
Units are:
Construction Debris Landfill
Chemical Waste Pit
Tabbs Creek
Stratum Substation
These four remaining Operable Units are currently being independently investigated under CERCLA and will be
addressed in future Records of Decision.
V. SUMMARY OF SITE CHARACTERISTICS AND EXTENT OF CONTAMINATION
Summarized below are the relevant findings of the work to date with regard to contaminated soil located within
the boundaries of the Area E Warehouse OU.
A. SITE CHARACTERISTICS
1. Geology
LaRC is situated within the Atlantic Coastal Plain physiographic province, which consists of an eastward
thickening sedimentary wedge composed of unconsolidatedgravels, sands, silti. and clays, with variable amounts
of marine fossils. LaRC is underlain by approximately 2.000 feet of unconsolidatfd sediments.
The uppermost soil units (excluding fill material) are Holocene age deposits and Pleistocene deposits of the
Norfolk Formation. Holocene deposits, consisting of organic clays, silts, and silty clays, are encountered in
proximity to the margins of tidal estuaries that border LaRC. These deposits are up to 30 feet thick along the
northern border of the facility. Away from the tidal estuaries, surface soils consist of the Norfolk Formation, a
member of the Pleistocene Age Columbia Group. Soils of the Norfolk Formation consist of sequences of silt.
clay, and silty to clayey sands that are typically dry to moist and slightly to moderately plastic. Anerosional
surface separates this unit from the underlying Bacons Castle Formation.
The Pliocene Age Bacon Castle Formation, composed of the Moore House Member, occurs at depths of 50 to 60
feet at LaRC. The Moore House Member consists of sequences of silty sands containing marl and shell hash
lenses. These marl and hash lenses are absent at some locations. The Mogarts Beach Member of the Yorktown
Formation is encountered at depths of 70 to 80 feet. The Mogarts Beach Member is a distinctive hydrologtc unit
consisting of blue clay of up to IS feet in thickness; however, it is absent at some locations.
2. Hydrogeoiofj
Groundwater in the area can be found at a depth of 5 to 50 feet below the land surface. This aquifer, known as
the Columbia aquifer, is brackish and. its use is limited to lawn and garden watering. Both the Yorktown and the
Yorktown-Eastover aquifers underlie the Columbia aquifer. The Yorktown-Eastover aquifer is confined and is
used as a source of domestic potable water.
3. Meteorology
The climate at the Site is characterized by mild winters and warm and humid summers. The climate is affected
by the Chesapeake Bay and Atlantic Ocean to the east and mountains to the west. During the winter.
temperatures reach a high of near SO with lows in the 30s. In the summer, the highs are generally in the 80s with
lows around 70.
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The mean annual precipitation at the Site is 44.15 inches. Maximum precipitation occurs in July and August.
while the minimum occurs in November and April. However, precipitation is distributed throughout the year.
The average number of days with precipitation ranges from 7 to 11 days per month and 110 days per year.
Snowfall in the winter averages 10 inches per year, however, it is extremely variable, ranging annually from 0 to
45 inches.
The prevailing wind direction is south-southwest in April and May, southwest in June to September, and north in
October to March. The average wind speed is 5 to 8 knots.
4. Ecology
Open land, woodland, wetland and aquatic habitats are all found within or near NASA LaRC. These include
mowed fields and lawns, nonforested overgrown land, wooded areas, forested wetlands, scrub/shrub wetlands.
creeks, tributaries and steams. While the majority of the Area E Warehouse OU is paved/graveled, runoff from
the OU flows to a small drainage ditch approximately 120 feet in length and located immediately adjacent to the
Area E Warehouse OU. The ditch discharges into the site-wide drainage system which ultimately discharges into
the Tabbs Creek estuary. The distance from the drainage ditch to Tabbs Creek is approximately K of a mile.
5. Soils
Soil at the Area E Warehouse OU has generally been graded and/or filled to support buildings and road surfaces.
Coarse sand and gravel is found within the upper two feet of the ground surface. Grass covered areas were
graded with topsoil and some subsurface soil samples encountered the Norfolk Formation.
6. Groundwater Use
Groundwater in the area can be found at a depth of 5 to SO feet below the land surface. This aquifer, known as
the Columbia aquifer, is brackish and, its use is limited to lawn and garden watering. It is currently not used or
usable as a source of potable water. Both the Yorktown and the Yorktown-Eastover aquifers underlie the
Columbia aquifer. The Yorktown-Eastover aquifer is confined and is used at other locations as a source of
domestic potable water.
B. NATURE AND EXTENT OF CONTAMINATION
In April of 1988 a Preliminary Assessment (PA) was completed for NASA LaRC which included the Area E
Warehouse OU. Based on the results of this study a Site Inspection (SI) was completed in May of 1989. The SI
recommended that additional sampling and investigation be conducted at the Area E Warehouse OU. NASA
proceeded with a Site Assessment (SA) in 1990 to establish the potential risk posed from OU contaminants.
The SA involved the identification and detailed evaluation of potential remedial alternatives and concluded with a
recommendation of the preferred remedial alternative.
A Contamination Assessment (CA) was conducted in October 1992 to further delineate the extent of contaminated
soil at the OU. A focused sediment sampling effort in the nearby drainage ditch was also conducted in 1994. In
addition, an Addendum to the SA was prepared in August of 1995 to clarify the data presentation in the original
SA report.
The following is a summary of the sampling results of these investigations.
SOIL
Mrtah
A total of 47 soil samples [(35 surface soil (0-6 inches) and 12 subsurface soil (6-24")J were collected at the Area
E Warehouse for metal analysis during the SA (Figure 3). The metals were characterized using two analytical
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approaches: the total concentration of inorganic constituents of concern ("Total Metals") in the samples: and the
metals concentration in leachate produced by the Toxic Characteristic Leaching Procedure (TCLP).
Lead was detected in ail-soil samples ranging from 3.1 to 63 mg/Kg. Lead was not detected above twice the
background reasonable maximum exposure (RME) (20.7 mg/Kg) level in any of the subsurface soil samples. The
RME is the 95% upper confidence limit of the arithmetic mean. In surface soil samples, lead was detected
slightly above twice the background in one warehouse area (44 mg/Kg) and two north storage area samples (47
and 63 mg/Kg) obtained from the site. TCLP results for lead were reported in three samples with a range from
0.085 to 0.434 mg/L. The regulatory TCLP limit for lead is 5 mg/Kg.
Trace amounts of mercury were detected above twice the background soil values at the site. The concentrations
ranged from non-detected to 2 mg/Kg. No mercury was detected in the TCLP leachate.
Manganese was detected above twice die background soil sample values. Concentrations were reported at 1.100
mg/Kg and 913 mg/Kg in warehouse area surface soil samples, and 1,220 mg/Kg in one subsurface soil collected
in the west area of the site. The mean value for manganese concentrations was the highest for the warehouse
surface soil samples which was statistically significant. Manganese was not detected above twice the RME in
subsurface or surface soil samples collected from the north storage area of the site.
PCBs
Surface and subsurface soil samples were obtained from Area E and analyzed for PCBs during the SI. SA and CA
(Figure 4). The result of surface soil samples collected from 2 to 7 inches below grade showed that PCBs were
detected in 41 of the 53 surface soil samples. A frequency distribution of these detections includes:
> 1,000 Mg/Kg - 10 samples
200 Mg/Kg- 1,000 Mg/Kg- 11 samples
< 200 Mg/Kg - 20 samples
The highest PCB concentration (4.800 Mg/Kg) was detected at S-SS-17-01. at the southeast corner of Building
1170. Soil sample SS03-01, which exhibited a PCB concentration of 4,300 Mg/Kg. was collected approximately
15 feet west of S-SS-17-01. Soil samples S-SS-02-01 and S-SS-03-01. located northeast of Building 1206,
contained PCBs at a concentration of 2.500 Mg/Kg and 3.100 Mg/Kg, respectively. The geometric mean of PCBs
detected in the surface soil is 324 Mg/Kg.
A total of 25 subsurface soil samples were obtained from 8 to 55 inches; most samples were between 10 inches
and 22 inches. PCBs were detected in 10 of the 25 samples. A frequency distribution of these detections
includes:
> 1.000 Mg/Kg - 2 samples
200 Mg/Kg - 1.000 Mg/Kg - 4 samples
< 200 Mg/Kg - 4 samples
The highest PCB concentration (3,800 Mg/Kg) was detected at SB37-01, east of Building 1173, at a depth of 10
inches below grade. The geometric mean of PCBs detected in subsurface soil is 226 Mg/Kg.
GROUNDWATER
Metals
One groundwater sample was collected from the Columbia aquifer at the west area of the site and was reported
with concentrations at 56 and 1,280 Mg/L for lead and manganese, respectively. These concentrations, however.
are consistent with naturally occurring background levels of these constituents in the area of Area E Warehouse
OU and are not attributable to present or past activities at this OU. The mercury result was rejected; however.
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•2619)00
LEGEND
PROPERTY LINE
ROADS
FENCES
BUILDINGS
CATCH BASIN
A soMrAcs/tuMtmrACS son. SAMTU
• tOltFACX SOU, SAMTLB (19M.90)
0 soMtmrACS sou. SAMPLS d»«t)
Q
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"2619:00
LEGEND
- — — — PROPERTY LINC
ROADS
FENCES
BUIUOINGS
t CATCH BASIN
A SURfACf/SUBSURfACC SOU. SAXFUC (1990)
• SUMAC! SOIL SAJ0LB (19S9,90)
9 SUISU1VACS SOIL SAKTLI (19t9)
O SURFACX SOIL SAHTLC (1992)
• SU8SUIVACE SOIL SAJtfU (1992)
'1.30
Scai« in Feet
NOTE: Prefix B and S Cor 1989 staple locations
Prefix SS and BK Cor 1990 sample locations!
PreCix SS and SB Cor 1992 saaple locations
FIGURE 4
AREAS ABOVE 90 ug/Vg RISK-BASED LEVEL
NASA LARC AREA E SITE
Prepared by: Ebasco Services incorporated
6B
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the reported value was below the detection limit.
PCBs
Two groundwater samples were collected in the west area of the site (Figure 5). No PCBs were detected.
SEDIMENT
Two surface sediment samples were collected at a depth from 0 to 1 foot from the drainage ditch that drains the
stormwater runoff from the Area E Warehouse site (Figure 6). Both locations showed extremely low
concentrations of PCBs. 10. 1 and 143 pg/Kg. respectively. The results revealed that the migration of PCBs from
the site was insignificant.
Contaminant Fate and Transport
The environmental fate and transport of the contaminants present at the Area E Warehouse Site was studied to
determine the potential for continued on-site and off-site migration of the contaminants of concern. The results of
the study concluded that metals and PCBs exhibit relatively high persistence in the environment of the site. Due
to the low solubility of these contaminants in water, low vapor pressure, and strong adsorption to soils, sediments.
and organic matter, adsorption is the predominant fate process for the metals and PCBs at the site.
Since the terrain of the site area is flat with a shallow groundwater table below the ground surface, the most
probable path of migration for contaminants is into the groundwater. The potential migration of the contaminants
was predicted by using the Rapid Assessment Groundwater Model (Donnigian, et al., 198S). The results of the
model showed there would be insignificant metal leachate concentrations (approximately 1.6x10*" mg/L) reaching
the 3 foot depth in ten years. No Aroclor 1260 would migrate to the depth even when the analysis was extended
to 30 years. Aroclor 1260 is one of the major PCB compounds detected in soil .of the site. Therefore, the
potential migration of the site contaminants to the groundwater system is minimal.
VI. SUMMARY OF STTF BISKS
A risk assessment was conducted in the SA in accordance with the latest EPA policy on Risk Assessments
(USEPA. 1989). The results are summarized below.
Health risks are based on a conservative estimate of the potential carcinogenic risk or potential to cause other
health effects not related to cancer. Carcinogenic risks and noncarcinogenic risks were evaluated as pan of the
risk assessment; three factors were considered:
I. nature and extent of contaminants at the OU,
2. the pathways through which human and ecological receptors are or may be exposed to those contaminants at
the OU, and
3. potential toxic effects of those contaminants.
For this OU, the human health risk assessment was based on exposure to soil under industrial land use scenarios.
Surface water was not evaluated because human health receptors are not exposed to this medium at this OU. In
addition, neither organic compounds nor PCBs were detected in groundwater. Only metals were detected in the
Columbia aquifer. The detected concentrations, however, are consistent with naturally occurring background
levels in the area of this OU and are not attributable to present or past activities at this OU. Even if water from
the Columbia aquifer were used for drinking, unacceptable risks would not be expected and. therefore, no action
is required for addressing groundwater.
Cancer risks are expressed as a number reflecting the increased chance that a person will develop cancer, if
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TABBS CREEK
PAVED DITCH DRAINS TO TABBS CREEK
**»-«. - ..PEP,,.,.
AREA E WAREHOUSE
STORM DRAIN 0
MONITORING WELL 1
(APPROX OCATION)
Sco" "» r«««
ISO
FIGURE 5
MONITORING WELL LOCATIONS
FOR AREA E WAREHOUSE
EBASCO SERVICES INC ORATED
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LEGEND
- - - - ASS,* eOUNCA«!ES
•——• Si"£ SOUNOAfiY
- - - - Fsc*::=Tf LINE
F.OACS
rENC£S •
• SEDIMENT SAMPLE LOCATION
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HGURE6
AREA E WAREHOUSE SAMPLING LOCATIONS
Prepared by: Ebasco Services Inc.
7B
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he/she is directly exposed (i.e., through working at the OU) to the contaminants found in the groundwater. surface
water, soil and sediment at the OU for 30 years. For example, EPA's acceptable risk range for cancer is I * 10~*
to 1 x 10"*, meaning there is one additional chance in ten thousand (1 x 10" ) to one additional chance in one
million (1 x 10"4 ) that a" person will develop cancer if exposed to a hazardous waste site. The risk associated with
developing other health effects is expressed as a hazard index. A hazard index of one or less means that a person
exposed to a hazardous waste site is unlikely to experience adverse health effects. A hazard index is also used to
evaluate ecological risks.
Direct contact, including oral and dermal exposures of contaminated soils, forLaRC workers was calculated for
the Risk Assessment. The assumptions and results are presented in Tables 1 and 2. The lifetime cancer risk from
PCB exposure for the workers at the Area E Warehouse site is calculated at 4.9 x 10 J. This lifetime risk is within
the EPA's acceptable risk range of 1 x 10* to I x 10". The HI for the non-carcinogenic risk due to exposure to
metals in contaminated soils was estimated to be 0.2, which is below the target of 1.0.
Potential exposures to site-related contamination under future use were also considered. However, it is unlikely
that the use of this area will change in the succeeding years as it is a pan of a large government-owned research
center.
The major uncertainties in the Risk Assessment are the exposure factors (duration and magnitude). Since daily
occupation of the warehouse area does not presently occur, the exposure assumption that a worker will be on site
each working date and exposed to soil under the exposure conditions each day is conservative. The uncertainty in
the risk assessment, based on the given soil concentrations and exposure factors, is estimated to be a factor of ten
on the high side.
The two potential pathways for ecological impact identified were through sediment transport of contaminated soils
to the estuary and/or groundwater infiltration. Sediment transport is through surface runoff which carries
contaminated soil into the storm drain, and ultimately into the estuary. Because of the flat profile of the area,
sediment transport is very unlikely. The sediment samples collected from die storm drain adjacent to the site
reveal only extremely low levels of PCBs.
Both metals and PCBs exceeded ecological screening levels for soils which suggests potential risk to the
environment. Soil screening levels which are exceeded include:
Manganese: 330 ppm
Lead: 10 ppm
Mercury: 0. IS ppm
PCBs: 0.10 ppm
Although soil screening levels have been exceeded in the soil at the Area E Warehouse OU, there is no indication
from samples taken in the storm drain or in the estuary that there exists an ecological risk as a result of surface
runoff from the site. In addition, because of the current industrial setting of the Area E Warehouse OU it is a very
unlikely location for a terrestrial habitat.
CONCLUSIONS
The remedial objective for the Area E Warehouse is to protect human health and the environment. Because the
current and anticipated future land use is non-residential, soils were evaluated only for construction worker
exposure. As indicated above, the risk posed to the construction worker is within EPA's acceptable risk range,
however, actual or threatened releases from hazardous substances may present an imminent and substantial
endangerment to public health or welfare under a non-industrial exposure scenario. The specific remedial
objective for this operable unit, therefore, is to assure that the property use does not allow non-industrial exposure
to the soils.
-------
VII. DESCRIPTION OF ALTERNATIVES
The Site Assessment for the Area E Warehouse OU presents three alternatives that address risks posed by PCBs
and metals contaminated-soil. The soil remediation technologies were identified and screened using effectiveness
and implementability as the criteria. The screening process is described in Table 5. Table 6 summarizes the
process options that were screened, including the no-action alternative. Three process options (no- action.
gravel/asphalt cap, and off-site landfill) were retained to form alternatives, with two process options retained as
support technologies. Using these retained process options, three alternatives: 1) no-action: 2) excavauon/off-sue
disposal: and 3) capping were developed for detailed analysis as follows. In addition, a fourth alternative was
developed and discussed in a letter from NASA to EPA and VDEQ. This alternative is a hybrid alternative
referred to as institutional controls and was also retained.
Alternative I - No Action
The NCP requires that a "no action" alternative be considered to provide a baseline for comparison with action
alternatives. Under this alternative, no remedial action would be undertaken at this time to address contaminated
soil at the Area E Warehouse OU. •>
• Capital Cost: SO
• Operations and maintenance (O&M) cost: $0
• Net present worth: SO
Alternative 2 - Excavation fnA Off-Site Disposal
This alternative involves excavating approximately 3,700 cubic yards of contaminated soil and disposing the
material in an approved -off-site facility. Upon completion of the excavation, clean material would be used to
backfill the excavated areas. The site would be restored back to the original level and condition including
regrading to promote drainage and revegetation as appropriate to prevent soil erosion.
Long-term monitoring would not be included with this alternative. Aconfirmatory sampling program, however.
would be undertaken during the remedial action to ensure contaminated soil above the cleanup level has been
removed.
• Capital Costs: SI. 500,000
• Operations and maintenance (O&M) cost: SO
• Net present worth: $1 .500,000
Alternative 3 - Containment
This alternative consists of covering the contaminated areas with clean soil or gravel. If the existing contaminated
area is a grassy area, then a 10" top soil cap would be installed. If the existing area is covered with gravel, then
the existing gravel should be removed prior to the placement of new gravel or top soil, or alternatively, a 6" layer
of asphalt mix shall be placed on top of the contaminated gravel. In addition, this alternative would incorporate
institutional controls and a long-term monitoring plan. Also, a confirmatory sampling program would be
undertaken during the remedial action to delineate the PCB-contaminated areas to be covered to ensure the
effectiveness of the remedy.
• Capital Costs: $168.000
• Operations and maintenance (O&M) cost: SO
• Net present worth: SI 68.000
AJteTPftt'v* ** • Institution
This alternative consists of a use restriction on die property to prevent non-industrial activities (e.g.. residential.
-------
child care, or recreational uses). These restrictions include: 1) the prohibition of use of the property for
purposes other than industrial (e.g.. residential, child care, or recreational use); 2) inputting these restrictions in
the NASA LaRC Master Plan; 3) within 90 days of ROD signature, NASA shall produce a survey plat prepared
by a professional land-surveyor registered by the Commonwealth of Virginia indicating the location and
dimensions of the Area E Warehouse Operable Unit and the extent of the soil contamination. The plat shall
contain a note, prominently displayed, which states the owner's future obligation to restrict the land use of the
property. The plat shall be submitted to the local recording authority; 4) NASA shall incorporate these
restrictions and supply a copy of the plat into any real property documents necessary for transferring ownership
from NASA, in the unlikely event that NASA sells the property. The real property document would also include
a discussion of the National Priorities List (NPL) status of this Site, as well as a description of the soil
contamination: 5) The NASA LaRC Environmental Engineering Office Head will certify to USEPA on an annual
basis that there have been no violations of these prohibitions. If a violation has occurred, a description of the
violation and corrective actions to be taken will be provided.
In addition, the presence of the existing security fence around the OU serves to limit access to the OU. Although
the purpose of the fence around the OU is for providing security (its presence and maintenance is not pan of this
alternative) it also limits the individuals who may be exposed to the contaminated soils by preventing unauthorized
access.
Capital Costs: $2,000
Operations and maintenance (O&M) cost: $500
Net present worth: $16,500
The cost figures included here are estimates which reflect a reeavluation of the cost since the release of the
Proposed Plan. This difference results from adding extra components to the alternative. „ See Section XI.
Documentation of Significant Changes, below.
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
During the detailed evaluation of remedial alternatives, each alternative is assessed against the following nine
evaluation criteria: overall protection of human health and the environment; compliance with applicable and
relevant and appropriate requirements (ARARs); long-term effectiveness and permanence; reduction of toxiciry,
mobility and/or volume (TMV); short-term effectiveness; implementability; cost, state acceptance; and
community acceptance.
A comparative analysis for the four alternatives based on these evaluation criteria is presented in the following
sections.
A. OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
Alternative 1, No Action, provides no reduction in risk to humans and the environment. Alternatives 2 and 3
would provide adequate protection of human health and the environment by eliminating, reducing or controlling
risk through removal, engineering controls, or institutional controls. Alternative 4 would prevent exposure
through access restrictions and other institutional controls.
B. COMPLIANCE WITH APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
Under Alternatives 2. 3 and 4, all applicable or relevant and appropriate requirements (ARARs), would be met.
(Specific ARARs for the remedy in this case are identified in Section X.B. of this ROD).
C. LONG-TERM EFFECTIVENESS AND PERMANENCE
Alternative 2 would be the most effective since it would permanently remove the contaminated media from the
site. Alternative 3, the installation of a cover, although less permanent than alternative 2, effectively mitigates the
10
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risk associated with direct contact or ingestion of the contaminated media. The long-term effectiveness will
depend on maintenance of the cover and the adherence to imposed land-use restrictions. Since the contaminants
would remain on-site. Alternative 3 would provide less protection then Alternative 2. Alternative 1 would not
provide added protection Trom the contaminated soil. Alternative 4 will continue to prevent exposure and prevent
unacceptable risk by, among other things, prohibiting a non-industrial use of the property.
D. REDUCTION OF TOHCITY, MOBILITY, OR VOLUME BY TREATMENT
Alternatives 1 and 4 provide no reduction in the contaminant toxicity, mobility or volume of contaminated soil.
Alternative 2, excavation and off-site disposal, would effectively reduce the contaminant levels on-site. However.
Alternative 2 achieves this goal by moving the contaminated media to another location (off-site landfill) where its
mobility is reduced but its toxiciry and volume are unchanged. Alternative 3 would reduce the contaminant
mobility somewhat through the use of a soil cover, but toxicity and volume would remain the same.
E. SHORT-TERM EFFECTIVENESS
No short-term impacts to human health and the environment are associated with the implementation of
Alternatives 1 or 4, no action and institutional controls respectively, because physical remedial actions are not
undertaken. For Alternatives 2 and 3. which require excavation or containment, the potential short term risks are
those associated with dermal contact with and ingestion of the contaminated soil by workers. NASA, however,
would minimize these short-term risks by implementing controls and procedures to ensure, to the greatest extent
possible, that such dermal contact and ingestion did not occur. In the cases of these alternatives, workers would
be required to wear protective equipment during activities where they may be exposed to hazardous materials.
The short-term risk associated with Alternative 2 would be potentially greater than Alternative 3 because of the
additional handling of the contaminated soil.
F. IMPLEMENTABELITY
Alternative 1, no action, can be easily implemented because there are no construction, storage, equipment or
disposal considerations. Alternatives 2 and 3 (excavation/off-site disposal and containment) each are relatively
easy to implement because the required labor, equipment and materials are readily available. However,
Alternative 3 may be less implementable because of the change of existing OU topographic features. In addition.
Alternative 3 would require a long-term monitoring plan. Alternative 4 involves the restriction of future uses of
the OU to industrial activities. Implementation of Alternative 4 is relatively easy.
G. COST
Alternatives 1 has no costs associated with it. Alternative 4. institutional controls, is estimated to cost $16.500.
Alternative 3, containment, costs are estimated to be S 168,000. Alternative 2. excavation/off-site disposal, costs
are estimated to be SI.500,000 and is the most expensive.
H. STATE ACCEPTANCE
The Virginia Department of Environmental Quality concurs with the selection of Alternative 4.
institutional controls, as the selected remedy for this OU.
I. COMMUNITY ACCEPTANCE
An availability session on the Proposed Plan was held on-February 3, 1998 in Hampton. Virginia. Comments
received orally and/or in writing at the availability session are referenced in the Responsiveness Summary
(Section XII of this ROD). No written or oral comments were received outside of the availability session during
the public comment period.
11
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IX. fiFiIiFif^D REMEDY
Following review and consideration of the information in the Administrative Record Tile, requirements of
CERCLA and the NCR.-and public comments received on the Proposed Remedial Action Plan. NASA and EPA.
in consultation with VDEQ. have selected Alternative 4: Institutional Controls as the remedy for the Area E
Warehouse Operable Unit. This remedy would prevent unacceptable exposure to contaminated soils.
Based on available information. NASA and EPA believe that the selected remedy would be protective of human
health and the environment, would be cost effective, and would provide the best balance of trade-offs among the
alternatives with respect to the evaluation criteria.
The selected remedy for the Area E Warehouse OU includes the following major components:
1) the prohibition of use of the property for purposes other than industrial (e.g.. residential, child care, or
recreational use),
2) inputting these restrictions in the NASA LaRC Master Plan ,
3) within 90 days of ROD signature, NASA shall produce a survey plat prepared by a professional land surveyor
registered by the Commonwealth of Virginia indicating the location and dimensions of the Area E Warehouse
Operable Unit and the extent of the soil contamination. The plat shall contain a note, prominently displayed.
which states the owner's future obligation to restrict the land use of the property. The plat shall be submitted to
the local recording authority,
4) NASA shall incorporate these restrictions and supply a copy of the plat into any real property documents
necessary for transferring ownership from NASA, in the unlikely event that NASA sells the property. The real
property document would also include a discussion of the National Priorities List (NPL) status of this Site, as well
as a description of the soil contamination.
5) The NASA LaRC Environmental Engineering Office Head will certify to USEPA on an annual basis that there
have been no violations of these prohibitions. If a violation has occurred, a description of the violation and
corrective actions to be taken will be provided.
The present worth of this remedy is $16,500.
PERFORMANCE STANDARDS
A prohibition of use of the property for purposes other than industrial (e.g.. residential, child care, or recreational
use) will be imposed. All use restrictions will be inputted into the NASA LaRC Master Plan. Within 90 days of
ROD signature, NASA shall produce a survey plat prepared by a professional land surveyor registered by the
Commonwealth of Virginia inHir«ri«ig the location and dimensions of die Area E Warehouse Operable Unit and
the extent of the soil contamination. The plat shall contain a note, prominently displayed, which states the
owner's future obligation to restrict the land use of the property. The plat shall be submitted to the local
recording authority. NASA shall incorporate these restrictions and supply a copy of the plat into any real
property documents necessary for transfering ownership from NASA, in the unlikely event that NASA sells the
property. The real property document would also include a discussion of the National Priorities List (NPL) status
of this Site, as well as a description of the soil contamination. In addition, the NASA LaRC Environmental
Engineering Office Head will certify to USEPA on an annual basis that mere have been no violations of these
prohibitions. If a violation has occurred, a description of the violation and corrective actions to be taken will be
provided.
A 5-year review will be conducted in order to evaluate continuing protectiveness of human health and the
environment. Each required 5-year review will culminate in the preparation of a report. Specifically, the
effectiveness of the selected remedy will be reviewed, and a determination will be made as to whether adverse
12
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changes in risk have occurred at the Area E Warehouse OU. The effectiveness of use restrictions will be
evaluated and changes may be recommended at that time.
X. STATUTORY DETERMINATIONS
A. PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
The selected remedy. Alternative 4. would protect human health and the environment by preventing exposure
through (he use restrictions and other institutional controls.
B. COMPLIANCE WITH ARARS
The selected remedy will comply with all ARARs
1. Chemical-Specific ARARs
There are no chemical-specific ARARs for the selected remedy.
2. Location-Specific ARARs
There are no location-specific ARARs for the selected remedy at this OU.
3. Action-Specific ARARs
There are no action-specific ARARs for the selected remedy.
C. COST EFFECTIVENESS
The selected remedy is cost-effective. The present worth cost of Alternative 4 is SI6,500.
D. UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT
TECHNOLOGIES OR RESOURCE RECOVERY TECHNOLOGIES TO THE MAXIMUM EXTENT
PRACTICABLE
The selected remedy represents the maximum extent to which permanent solutions and treatment technologies can
be utilized in a cost-effective and timely manner. Of those alternatives that are protective of human health and the
environment and comply with ARARs, the selected remedy provides the best balance of trade-offs in terms of
long-term effectiveness and permanence, reduction of toxicity, mobility, or volume achieved through treatment.
short-term effectiveness, iraplementability and cost, while also considering the statutory preference for treatment
as a principal element and considering state and community acceptance: The selected remedy addresses the
principal threats posed by contaminated soils given the reasonably anticipated future use of the site.
E. PREFERENCE FOR TREATMENT AS A PRINCIPLE ELEMENT
The selected remedy does not satisfy the statutory preference for treatment as a principal element of the remedy.
Treatment remedies were not considered because of low levels of contamination. Although no active treatment is
employed with the selected remedy, the selected alternative would limit exposure to contaminated soils.
XL DOCUMENTATION OF SIGNIFICANT CHANGES
The preferred alternative in the Proposed Plan was Alternative 4: Institutional Controls. The only significant
changes to the proposed alternative described in the Proposed Plan is the addition of the survey plat requirement.
incorporation of these restrictions into the NASA LaRC Master Plan and the annual reporting on the continued
application of the institutional controls.
13
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. RESPONSIVENESS SUMMARY
A. OVERVIEW
In a Proposed Plan released for public comment on January 26, 1998, NASA, with the support of EPA, identified
Alternative 4 as the preferred remedial alternative for the Area E Warehouse OU at the Site. Alternative 4 in the
Proposed Plan was as described in Section VIII, with the additions discussed in Section XI.
There were no written comments received as a result of the public comment period. There were written
comments submitted during the February 5, 1998 availability session. After evaluating and addressing these
comments, NASA and EPA have decided to select Alternative 4 as the remedy for the Area E Warehouse OU.
Comments and the associated responses of NASA and EPA are described below after a brief discussion of
community involvement to date.
B. COMMUNITY INVOLVEMENT TO DATE
NASA and EPA established a public comment period from January 26, 1998 to March 11, 1998 for interested
panics to comment on the Proposed Plan, the Site Assessment. Contamination Assessment, focused sediment
sampling reports and other documents pertaining to the Area E Warehouse OU. These and all other documents
considered or relied upon during the remedy selection process for the Area E Warehouse OU are included in the
Administrative Record, which has been in two information repositories accessible to the public since the beginning
of the public comment period for the Area E Warehouse OU. An availability session was held at the Virginia Air
and Space Museum. Hampton. Virginia on February 3. 1998, to present the Proposed Plan, answer questions, and
accept both oral and written comments on the Area E Warehouse OU remedial alternatives. One person attended
this session.
This Responsiveness Summary, required by CERCLA. provides a summary of citizens' comments identified and
received during the public comment period and the responses of NASA and EPA in selecting the remedy for the
Area E Warehouse OU. Responses to these comments are included in the section below.
C. SUMMARY OF COMMENTS RECEIVED DURING PUBLIC COMMENT PERIOD AND
COMMENT RESPONSES
Comment #1:
My particular question was about the plan to test Tabbs Creek over the yean in the future. I was told that this
testing of biota would occur 2-4 times per year over the next five years. I agree this is good, but 5 years may be
too short - term; should be a long range plan as well.
Response #1:
The Tabbs Creek OU will be addressed in a future Proposed Plan and ROD. A monitoring plan will be included
in any remediation that may take place in Tabbs Creek. The details of the monitoring have yet to be developed.
This concern will be considered at that time.
Comment #2:
Groundwater may be contaminated in the future, so the suggestion to preclude the use of groundwater in the
future should be implemented.
Response #2:
Groundwater at the Area E Warehouse OU does not currently pose a threat to human health or the environment.
Upon completion of the studies at the remaining OUs. a determination will be made on what actions if any are
14
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necessary to address groundwater.
15
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REFERENCES
Anderson. E.N., S. Browne, Dulctslcy, and T. Warn (1984). Development of Statistical Distribution or Ranges
of Standard Factors Used in Exposure Assessments. Draft Final Report prepared for USEPA, Office of
Health Environmental Assessment under Contract No. 68-02-3510.
Donnigian Jr.. Anthony S.. T.Y. Richard Lo. and W. Shanahan (1985). "Rapid Assessment of Potential Ground
Water Contaminations. EPA Report. Contract No. 68-03-3116.
Ebasco. 1988. "Preliminary Assessment Report For Langley Resource Center."
Ebasco. 1989. "Report of Site Inspection. NASA, Langley Resource Center."
Ebasco. 1990. "Area E Warehouse Site Assessment, LaRC. Hampton, VA."
Ebasco. 1992. "Final Contamination Assessment Report, Area E Warehouse, LaRC. Hampton. VA."
U.S. Environmental Protection Agency. 1990. "Guidance on Remedial Actions for Superfund Sites with PCB
Contamination." EPA 540 G-90-007. August.
U.S. Environmental Protection Agency, 1989. "Risk Assessment Guidance for Superfund. Volume
I: Human Health Evaluation Manual." OSWER Directive 9285.7-Ola. Office of Emergency and Remedial
Response, Washington, D.C.
U.S. Environmental Protection Agency, 1988. "Guidance for Conducting Remedial Investigations and Feasibility
Studies Under CERCLA." Interim Final.
16
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APPENDIX A
TABLES
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TABLE 2
EXPOSURE AND INTAKE ASSUMPTIONS FOR
DERMAL CONTACT AND INGESTION
NASA LANGLEY RESEARCH CENTER
Workers
Age Group 18-70
Dermal Exposure to Soil (day/year) 78
Duration of Exposure (yean) 44
Frequency of Exposures (Dayj/yr) 244
Dermal Soil Deposition (mg/crrf) 1.4
Skin Surface Area Exposed (cm2) 3,600
Dermal Absorption Factors:
PCBs 12%
Metals 1.0%
Gut Absorption Factors:
PCBs 50%
Metals 50%
Soil Ingestion (mg/day) 100
Sources: Skin surface areas exposed are from Anderson, et al., (1984); other parameter values
were derived as described in the SA report.
A-l
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TABLES
AREA E WAREHOUSE
HAZARD INDEX AND EXCESS CANCER RISK
LANGUEY RESEARCH CENTER
Non-Carcinogenic Effects:
CD) = CDRD) + CDKD
CDl(DXmg/kg/day) - C(mg/kg) • DR(mg/cm*2) • ARI * SA(cm*2) • DE/36S(days/days) • l(T-6(kg/mg) / BW(kg)
CDKIMmg/kg/day> • C(in|/k|) • le 3.IE-02 74E-02 I.OE-OI
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TABLE 3 (Continued)
AREA E WAREHOUSE
HAZARD INDEX AND EXCESS CANCER RISK
LANGLEY RESEARCH CENTER
Area E Warehouse/Surface Soil
Exposure Roue: Soil (Denial Contact A Acrirknul Ingeaion)
Scenario: Long-Term Representative Exposure
Source: Surface Soil (Present and Funire)
Receptor: LARC Workers
Area of Exposure ==»=» = = >
Exposure Factors:
% Time Exposed per area
Days Exposed (per year)
Fractional days per year
Yean Expand (per 70 year life)
Body Weight (kg)
Soil Ingeflioa (me/day)
Surface Area Exposed (cm~2)
West
20*
220
44
42
70
100
3.800
Warehouse
40%
220
88
42
70
200
3.800
1 North
40%
220
88
42
70
100
3.800
Carcinogenic Effects:
CDI ~ CDI(D) •»• CDI (1)
CDKDXmg/kg/day) - C(inf/kg) * DR(mg/cro'7) * AFd * SA(cmA2) • DE/36S(days/days) • YE/70(years/yean) • I0*-6(kg/mg) / BW(kg)
CDKIXmg/k) CDKIXmf/kt/day) - COng/kg) • Mmf/day) • AF1 • DE/365(days/aayj) • YEAXKyean/years) • l(T-«(kt/nij) / BW(kg)
Compound
AF$
Denial
Dep.
CPF
Chronic Daily Intake and Cancer Risk for Age Group (years):
PCBs
AFd AFt (mg/cm*2)
Soil Cone (mg/kg) = = « = •
12% 50% 1.4E+00
Total Risk
12E+OI
Warehouse
CDI Risk CDI Risk
1.2E+00 I.2E+00
8.4E-07 9.7E46 I.8E-06 2. IE-OS
9.7E-06 2. IE-OS
North
CDI Risk
I IE+00
I6E46 I9E43
I9E-05
Lifetime
Ruk
49E-05
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TABLE 4
CLEAN-UP SOIL CONCENTRATION
AREA E WAREHOUSE/SURFACE SOIL
NASA LANGLEY RESEARCH CENTER
Scenario: Long-Term Representative Exposure
Source: Surface Soil (Present and Future)
Receptor: LaRC Workers
% Time exposed per area
Days Exposed (per year)
Fractional days per year
Yean Exposed (per 70 year life)
Body Weight (k|)
Sod Ingestion (rag/day)
Surface Area Exposed (cm~2)
U/«c*
20%
220
44
42
70
100
3.800
warcnouse
40%
220
88
42
70
200
3.800
Nonn
, 40%
1 220
88
42
70
100
3.800
I
Carcinogenic Effects: CDI« CDIfD) + CDI(I|
CDI|DKmg/kg/day) = Qmg/kg) • DR(mg/cm*2) • AFd • SA(cnT2) • DE/363(days/days) • YE/70(years/years) *
CDI|IKmg/kg/day) - Qmg/kg) * ls(mg/day) • AFi • DE/36S(days/days) * YE/70(years/yean) * l
Chronic Dail;
CDt Risk
90E-02
7-v^'^v*
6.4E-08 4.9E-07
4.9E-07
Chronic Daily Intake and Cancer Risk for Age Group (yean):
Warehouse
CDt Risk
9.0E-02
1.4E-07 I 1E-06
I.IE-06
North
CD! Risk
9.0E-02
I.3E-07 9.9E-07
9.9E-07
Lifetime
Risk
25E-06
2.SE46
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TABLES
SCREENING OF SOIL REMEDIAL TECHNOLOGIES
AREA E WAREHOUSE SITE
NASA LANGLEY RESEARCH CENTER
Technology Type:
Process Opdon(s)
No-Acaon
Limited Action:
Monitoring
Capping:
Gravel/Asphalt Cap
RCRA Cap
Removal:
Eicavaoon
Description
The MR a not irmrrtiainrl IB any way.
Low level 01 COfltJBanBntS VeflBVD OB
Ste.
Perform periodic analysis of ate toib to
nmiaminatinn
Cover contaminated toil with a single
layer of asphalt or f mvcl.
Cover contaminated sod wife a multi-
layer cap consisting of top soil, syndteoc
membranes, impenneabk soil, and
drainage layer.
Contaminated tot) would be removed
Eflcoivcnesi
Carcinogenic risk is witun EPA's acceptable
fcfcume risk ranfc U10* •> UIO4.
Eflecbve for monitonnt levcb of soil
conbuninaBon and «HfMi"" However, due
ID te tow levels of aoi caattninaoa. • a
unlikely dial PCBi would na|nae »
imindwaier or surface water at levels posinj
litairkaal ducats.
"^•*^™^*^*^
Reduces mobiiJiy of conimnaVitt tnd risk of
OO-SNC and nay be eiposcd from
en>sioii/ruain|.
• ftf^ufttt cnobiliiy of cootuMfttitt md risk
icnuun on-siie.
• Meets RCRA m|aiiftfntno
ni In iniia • il
miliBuBOB*
• RCRA sysvot is icbaUe for reducini
ten a mvRCRA synem for ndudm
contact risks.
* Effective at fctnovnf cocttniisQaiod SOM.
• Reqyifts Auter ocaBncot/dttposaU.
• Wil not reduce volutne or toxiciiy of
contunvttMDd soil.
•t^MU^H^MMaVy
C««ik* In | *
cASiy •»»yitjncasto.
Cott Low
C*«iKj MIWkkvi^Ffl^hfVl
CM»: Low/Moderaic
Construction is relatively easy.
Change in elevation due to installation of cap
may change fte dnunage pattern of te area.
Cost: Low/Moderate
• Construction requires multiple steps and is
Ome Cffinmntng.
wife ooo-RCRA layer cap.
advene cffcct on RCRA cap.
• Change h elevation due to imallarion of cap
would bnMcumnl use of pnptny.
Cost H%h
• TcchnkaOy fcasMe.
• Can be done usini common constiucoon
OttUDIDBfat.
• i"T *™ *"•
Cgsr. Low
SBUUS
I
Retained for ftmtier
consvleration
BuninMed as long u die
ste use is kept (he same.
Retained (01 funhcr
yiynii^yQji^iY
Eliminated due 10 HKCU!
site conuninu.
Retained for (unher
considerabon at a tuppon
technotofy.
-------
TABLES (Continued)
SCREENING OF SOIL REMEDIAL TECHNOLOGIES
AREA E WAREHOUSE SITE
NASA LANGLEY RESEARCH CENTER
Technoiofy Type:
Process OpoonU)
DetCnpBOe)
Effectiveness
Satis
Physical Treatment:
Sold Processing
Conan of pfayaofty sonnf and/or
modsfying we size tnl dMribunon of
ne toil oti my be eicavaied.
Does not itduce uuciiy or mobility at
coaarninana. but my reduce vohune of
teicnm te specsnc surface area of ne
toil.
More of a putiuunett nan a treatment.
Ropoica Hgnifkaot maieriab I
b required at a pnacaunen toe many
Etiminaied. |Ticaaneniof
toil
Coy Low
PhyikalTi
Process 10 tcraovc cicess (ftw) Ikyiid
faun sMuttcd OMNcnals pnof b
• Effe
Snynrt By hnnlnay .
Don am nducc noMiy or ttuciry of
. May itauk in sapiiAcani
Imnkmrnabiliry of dtwaierint. roohodt may
be djfficuk aomt tuauiifnt
or d^Mual Hcnnolofics.
• Ticatmeni of dnined water, if required.
woUht MBMC off-Mt htodUnf and disposal.
Cost Low
Solver* Etmcoon:
la-Sin Soil Fhuhinf
Couaminanu are removed from «oib
via in-iiai «oJveni nMnaoo.
Contaaiiniagd tgrvcnB are recovered for
wbtequeni ocaonen and/or dqposal.
Organic solvent used for PCB extraction
may be considered banidous.
sepaiMt torrents.
Reduces volume of cooaminants in toils;
however, produces tup vohjotes of
cotMnmiad solvents whicfe nquin
• Typically compki proccsies. diflkuh »
• tacaatJ far toa of solvents durinj
Biminued due lu
potenul for advene
cnviionmeMil effecu anl
amicipajed diflicuHy m
implcneiMabon.
Requires special provisions (i.e.. sheet
vure ^fnrtrit coUecoon of
_M_^_
Rdiabiiiy ofefloptecaoMi widiaD
Actuevtble level of conftraDtnl removal
may not be adequate ID attain necessary
acaonkvcfa.
• Cofacooei of U faisMnf sorveni may be
euemdy dMioilL
• Cofiecfed sorfcnts require ottmunt to
Con: Modeme
-------
TABLE 5 (Continued)
SCREENING OF SOIL REMEDIAL TECHNOLOGIES
AREA E WAREHOUSE SITE
NASA LANGLEY RESEARCH CENTER
Technology Type:
Process Opooofft)
TEA Exmcuoo
Fiufkn'*riitbttTTtfiOfi *
SoMifirtiinn
DdcnpttM
EnmrtoaflfonMir from cimviitri
ioib a achieved by canaani fee toil
(TEA) totvctt •> CUM cacnfcak
Piccext wed in bboniofy and iadutay
ID move PCBi Aon (nuforaKf oil.
AdMmt «rf p«T»«J««c HagMM M UCMB
a omHeaclaMe nMtral wbkb it cukr
K»h*nlle.
Elbctiveneu
conceaoiooft loitel for doponl.
* Pito itn dm far I\*P muinK is
ftvftiUbic foe tffih. HdiflBMttt ind dudccs.
•dioo levcb lo|y to
mcb tcaoo level* for
PCB*
.
Rich Kboa levels lor
PCBs
Fliminiinl duf 10
inpfovea cflccavencvt m
«nmotMlii«n PCBt *i te
sac.
-------
TABLE 5 (Continued)
SCREENING OF SOIL REMEDIAL TECHNOLOGIES
AREA E WAREHOUSE SITE
NASA LANGLEY RESEARCH CENTER
Tccbnotofy Type:
Process OpQMft)
DcacnptiM
Eflimwcncss
Impletncntaibiuiy
Sous
Biological Treatment:
Liquid totals CogOKt
In Sun Treatment Land
AuolicaikMi
*'i i '' •""••
Bacteria are used 10 degrade specific
organic ooaMMMB. May be
performed aVjiit, of in • batch IUUM
after eicavaom.
• Laboratory dcmomoioom have shown
KB compound! u be btodcgndabie.
Mercury my be auk and inhibit (town.
Treatment of <|*[*a|ar* only.
pemnt may be achievable.
Bench icak eating and pMot saidy
required.
Biological oeatmcnt has resuhed reduction
of PCBs 10 ten ten 1 ppn in tome bench
Specific woit widi biolo|icil degmbiion of
PCBi b »• experimental.
May produce waae icsiduali ieojuino(
(uitftef Btaoum and/or dupoial.
Piuteu bas BDC bom developed mfficiefidy
k> pennii tccume pmtioion of
Eliminated «ue u
eiDenmcaoJ DMIK. Uck
of piot teak data, ml
pmbaHiiy of OEM mtcoi«
the action levcta for PCB
contuninMcd tod
Modeme
>
oo
• Reaction product! have OM been
chincieiaed and
-------
TABLE 5 (Continued)
SCREENING OF SOIL REMEDIAL TECHNOLOGIES
AREA E WAREHOUSE SITE
NASA LANGLEY RESEARCH CENTER
Technology Type:
Process Opdontt)
Effectiveness
linpfctneniabiliiy
Sodus
Thermal Treatment:
Off-siie Incinemim
TWo types of ott-tm incineiMon tie
avertable: rotsiy kite and Whued
system. Roiuy kito nroduccs wise
of • pflfBvy
•Dd lined wik hycn ofl%lM-we%h(
cerate fiber blanket Thenfand
energy a provided by abcoBcaroide-
• Ptifonmace dan for incinemoa ue we8-
demaraoued wtti h%h eflkieocy far
destroy iaj oipak warn.
• WiU Ktiieve tttn^d fioum> levels.
• Peifonmnce dea ue leUebte.
• Places* win gcaente ck*o soil end only s
i~fvnal i"*ntr* of •*** icsidue. whicn
would be tandtod by to incincnaan
• Oincady sppi
ady four operating
Alfour
Eumimied due 10 cou
ineHecove!
baton in nmaiRj si capsciiy. Cspiciy b
• Ei
nnsponsttw we necessiiy.
Cog: H«h
ID be prac*sted b conveyed teoufb Ae
• ReducesTMV.
• Is not eflbciive lor nonjsnics oesflncn.
* OewMennj of soils msy be ivojuind.
On Sue Incmenoon
Seme u off-sisc. cicqM diM • noMr
incinenior would be locassd « te Ana
E Wvchousc site.
data for tafecnoon ate wdl-
demonsoiiBd widi high elfkieiicy foe
destroying organic wstscs.
• Win achieve augtt cleanup fcveb.
• Rdkeiuty in te field has oat been wen-
UunumuMad. Cuneody k§s been used si
ontyafcwwajes
• ReducesTMV.
• bnotcffecovefori
• IYe-ats«nMofsain*ybem|uind.
• Mobile sod mnsporablc urau ue avwtable
for on-ske incinendoa.
• On-siss ipcinen be buik. Amobik
iocioeraBr decs not require pcnninnj if • is
Eluninaiod due » high
cost.
Air poJudoa tuaiul eyipaeni is typicslly
• Adiftt
detaedorptacediisRCftAfkil«y.
isnlcicavsionsBOuldbe
Con: H«h
Thermal TitamttM:
Viinncsuon
Ekcutxki imened into soil (n-wu)
conumm sijnificani levels of silkMes.
GnpniK is placed on die soil suifacc »
connect die deorades. The beat
IcncnMt hum
-------
TABLE 5 (Continued)
SCREENING OF SOIL REMEDIAL TECHNOLOGIES
AREA E WAREHOUSE SITE
NASA LANGLEY RESEARCH CENTER
Tcchnok>(y Type:
Process Opoon(»)
Descnpoon
Effectiveness
ImpkmentabiUry
Thermal Treatment:
Low-Teinpcraain:
Thermal Extraction
Organic waste* are removed from soil
by introducing heated tit into • reactor
widi die soil to strip oottuniotOM from
soil. Excavation is nrjuind for
Hat been demonstrated to remove certain
organic* from solid*.
Not proven and not likely to remove PCBs
and otter noo-vobnk comarainanu.
Anoter tBcteoloiy would be required to
defray organic* removal.
Reduces volume* of WUK.
• Imptcmcnabk. Could be constructed on-
site or preassanbfed mobtk units could be
transported to die site.
• Site space consninu «««™-j««««f wMh
cicavaboB riffldit be cnnudrred.
• May be mad in aimfiannn wift odier
Con: H«h-
Elimimied due w
iraMvy iJ cnecovely
uiai PCB* ant
inotianics.
On SMC Disposal:
On SMC Landfill
Soil from contaminated aica* are
eacavated and dHpmnd of in an
approved tacikiy constnicted oo-ute.
Rdiabte meted » oonain wufes.
VokMne or louciiy of was* b DM reduced.
Protective by reducinf direct exposure to
• Water-saMMtd matrnalt would require
cater sotidifiuMiuo or dewaatrinf prior u
Eliminated due to MIC
• Co
and lanj-tenn
indudmt lack of
sufficient space.
• Potential long-acrm liability for waste
Cost Moderate
Off-Site Disposal:
Off-Site Landfill
Waaes with PCBs <» pproare
excavated, transported, and disposed of
at a Virginia Department of Want
Management approved off-sac tandfiB.
• Effective in reducing direct contact risk.
• Volumeorioxicityof wasKisnM
decreased.
• Exposure to soil during excavation and
nmporaoon could pose a heaat hazard.
• Potential for long-lean liability tot waste
placed in bniM.
• OfT-sia: hndtii capacity is Unwed.
• Increased risk of exposure during
Retained for further
consideration.
Con: Moderate
-------
TABLE 6
SUMMARY OF ALTERNATIVE SCREENING
SOIL REMEDIAL TECHNOLOGIES
NASA AREA E WAREHOUSE SITE ASSESSMENT
General
Response Actions
No-Action
Limited Action
Containment Actions
Removal Actions
Treatment Actions
Remedial
Technology T
Monitoring
Capping
Excavation
Physical Treatment
Solvent Extraction
Fixation/Stabilization
Biological Treatment
Thermal Treatment
Disposal Actions
On-Site Disposal
Off-Site Disposal
No-Action
Monitoring
Gravel/Asphalt Cap
RCRAType
Excavation
Solids Processing
Dewatering
In-SiOi Soil Rushing
TEA Extraction
Critical Fluid Extraction
Solidification
Liquid-Solids Contact
ln-Situ Treatment
Land Application
UV/Oxidation
Dechlorination KPEG
Off-Site Incineration
On-Site Incineration
Vitrification
Low Temperature Thermal
Extraction
On-Site Landfill
Off-Site Landfill
Status
Retained
Eliminated
Retained
Eliminated
Retained*
Eliminated
Eliminated
Eliminated
Eliminated
Eliminated
Eliminated
Eliminated
Eliminated
Eliminated
Eliminated
Eliminated
Eliminated
Eliminated
Eliminated
Eliminated
Eliminated
Retained
Note: * * As support technology
A-ll
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