PB99-963903
EPA541-R99-007
1999
EPA Superfund
Record of Decision:
Langley Air Force Base
NASA Langley Center OU 42
Hampton, VA
1/14/1999
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. RECORD OF DECISION
LANGLEY AIR FORCE BASE
OPERABLE UNIT 42 (OT-38 AREA A AND AREA B)
~
SncNAMEANDLOCA~ON
Langley Air Force Base
Operable Unit 42 (Installation Restoration Program [IRP] Site OT -38 Area A and Area B)
Hampton, Virginia.
STATEMENT OF BASIS AND PURPOSE
.'
This Record of Decision (ROD) presents the selected remedial action for Operable Unit (OU) 42
at Langley Air Force Base (AFB) in Hampton, Virginia. chosen in accordance with the
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, '
as amended, 42 U.S.C.~~9601-967S and, to the e.xtent practicable, the National Oil and .
Hazardous Substances PolIution Contingency Plan (NCP), 40 CFR 300. This decision is based
on the Administrative Record for this site.
The Virginia Department of Environmental Quality (VDEQ) concurs with the selected remedy.
DESCRIPTION OF THE SELECTED REMEDY
OU-42 is part of a comprehensive environmental investigation and cleanup currently being
performed at Langley AFB under the CERCLA program. This ROD addresses only OU-42; the
other OUs located at Langley AFB are being investigated separately under its installation.
restoration program and will be addressed in future RODs. Also, this ROD addresses only soils
at the OU. The groundwater is being treated as a separate OU and will be addressed on an
installation-wide basis.
Langley AFB, EPA, and VDEQ have determined that no action is necessary for this site. Risk
assessment results indicate that OU-42 soils do not pose an imminent or substantial danger to
public health, welfare, 'or the environment.
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DECLARA TlON OF STATUTORY DETERMINATIONS
Risk assessment results from the remedial investigation (RI) perfonned at the OU indicate that
No Action is necessary to be protective of human health and the environment.
~~, ~~~~
THOMAS J. KE K '
Lieutenant General, USAF
Vice Commander, Air Combat Command
~~rr
Date
~~~
ABRAHAM FERDAS
Director
Hazardous Site Cleanup Division
U.S. Environmental Protection Agency
Region III
~
Date.
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RECORD OF DECISION
LANGLEY AlA FORCE BASE
OPERABLE UNIT 42 (OT -38 AREA A AND AREA B)
December 1998
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TABLE OF CONTENTS
Section
eaa
I.
Site Name, Location, and Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
n.
Site History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
In. Highlights of Community Participation. . . . . ; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
IV. Scope and Role of Operable Unit. . . . . . . . : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
v.
Summary of Site Characteristics and Extent of Contamination. . . . . . . . . . . . . . ... . . . . . . 5
VI. Current and Potential FutUre Site and Resource Uses. . . . . . . . . . . . . . . '. . . . . . . . . . . . . 11
YD. Summary of Site Risks. . . . . . . . . . . . . . . . . . . . . . '.' . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
vm. Significant Changes from Proposed Plan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
IX. Responsiveness Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..14
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APPENDIX A
Table
I
2
3
APPENDIX B
FIgure
1
2
3
4
S
APPENDIX C
GI08Hry
APPENDIX D
References
Title
Summary of Operable Units Under CERCLA Investigation
Exposure Parameters and Equations Used to Estimate Potential Chemical
Intakes and ContaCt Rates for Receptors at Langley AFB. Virginia
Human Health Risk Assessment Summary for OU-42
(OT-38 Area A and Area B)
Description
Location Map. Langley Air Force Base. Virginia
Base Map of Langley AFB Showing the Location
of the Site (OT-38 Area A and Area B/OU-42) and CERCLA OUs
OT-38 Area A Sampling Locations
OT -38 Area A Direct Push Soil Results Greater than
RBSLs and Background U11..s
OT-38 Area B Sampling Locations
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Ust of Acronyms
AFB
bgs
CERCLA
COPC
COPEC
Of
ooD
EPA
HI
IRA
IRP
IT
msl
NCP
NPL'
OU
PCB
ppm
PRO
RI
ROD
RME .
SI
Versar
VDEQ
Air Force Base
below ground surface
Comprehensive Environmental Response, Compensation and Liability Act
chemical(s) of potential concern
constituent(s) of potential environmental concem
degrees Fahrenheit
U.S. Department of Defense
U.S. Environmental Protection Agency
hazard index
interim removal action
Installation Restoration Program
IT Corporation
mean sea level
National Oil and Hazardous Substances Pollution Contingency Plan'
National Priorities List
Operable Unit
Polychlorinated biphenyl
part( s) per miJJion
Preliminary Remediation Goal
Remedial Investigation
Record of Decision
Reasonable Maximum Exposure
site inspection
Versar, Inc.
Virginia Department of Environmental Quality
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. RECORD OF DECISION
LANGLEY AIR FORCE BASE
OPERABLE UNIT 42 (OT -38 AREA A AND AREA B)
. ,
I.
Langley Air Force Base (AFB) is located near Hampton. Virginia, which is part of the Norfolk
metropolitan area, as shown in Figure 1 (Appendix B). The base. which covers 3.152 acres. was
established in 1917 and has the distinction of being the oldest continuously active AFB in the
United States. The base is sitUated between the northwest and southwest branches of the Back
River. a tidal estuary of Chesapeake Bay.
Operable Unit 42 (OU-42) consists of two fonner bum pit areas known as OT -38 Area A and
OT -38 Area B. The two areas are located within the central portion of the AFB (Figure 2). The
surroUIiding land use is primarily open space and industrial areas. A description of the two areas
taken from the remedial investigation (RI) reportl is provided below:
A.
OT-38 Area A
Area A comprises a bum pit, which was originally believed to be close to the RV (recreational
vehicle) storage compound just northwest of the main runway (Figure 2). This area was used
during the late 19405. However. aerial photographs dating from 1942 contained evidence of
possible bum pits located in pastureland to the southwest of the area originally indicated. An
open area, approximately 200 feet long by 100 feet wide. containing a flat square structUre either
with elevated sides or with a fence around it, was identified in an aerial photograph. This area
also contained tWo smaller circular structures. one with elevated sides and the other with a topo-
graphic depression within its circumference. The circular depression may have been the bum pit.
There is no eVidence of the presence of the pits or the associated structures in the subsequent
aerial photographs dating from 1944 to 1990. The boundaries of OT -38 Area A were redrawn to
reflect this information. Access to the area was via an unpaved road leading from Durand Road.
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-~~ ----~_.~ -
B.
OT -38 Area B
Area B was reported to have been located immediately east of Weyland A venue. near Building
1096 and lorn. The area was apparently used from about 1917 to the mid-I940s. Aerial photo-
graphs of the area. dating from 1937 to 1990. contain no evidence of a pit at this location. A
photograph dating from 1937 does, however, contain evidence of tWo non-vegetated. circular
featUres surrounded by grass and scrub vegetation located approximately 300 feet southwest of
. this area. These features may. intact. have been the bum pits. The boundaries of OT-38 Area B
were redrawn to reflect this infonnation.
II.
SBI..I:ilI1mJ
This section describes the history of waste disposal in addition to actions taken in response to
Comprehensive Environmental Response. Compensation. and liability Act (CERCLA) investi-
gations at OU-42.
A.
History of Waste Disposal
The mission of Langley AFB has changed during its history. To support its various missions.
quantities of petroleum, oils, and lubricants (POls), solvents, pesticides, photographic chemicals,
and protective coatings have been used. Some of the resulting wastes were disposed of in bum
pits such as OU-42. The two pits were used primarily for burning waste oil and trash resulting
from mission activities of Langley AFB. The years of operation for OT -38 Area A were during
. .
the late 1940s and for OT -38 Area B were from about 1917 to the mid-1940s. No interim actions
have been perfonned at this QU.
There are currently 23 other QUs being investigated at Langley AFB. Figure 2 provides the loca-
tion of these areas. Table 1 (Appendix A) provides a brief summary of these aus.
B.
CERCLAlnvesUgadona
Three CERCLA investigations have been performed at the OU. The au was originally identi-
fied during the 1981 Installation Restoration Program (IRP) records search but was not recom-
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mended for investigation at that time2. The second investigation was the site inspection (SI) and
screening risk assessmenrl. ~ report was used to detennine the presence or absence of con-
tamination at OT-38 resulting from past waste disposal practices. The SI indicated that chemicals
of potential concern (COPCs) at Area A included metals and semivolatile organic compounds
(SVOCs). COpes at Area B were several metals. Also, some of the ecological COpes were
identified as having high bioconcentration and biomagnification potential.
The third CERCLA investigation was the RIJ. The RI was performed to further characterize
potential environmental contamination from the OU and t~ conduct baseline human health and
ecological risk assessments. The results of the RI indicated that the OU does not pose an
unacceptable risk to human health or the environmenL
III.
Highlights of CommuniW Participation
In accordance with Sections 113 and 117 ofCERCLA, 42 U.S.C. Sections 9613 and 9617,
Langley AFB, in conjunction with the U.S, Environmental Protection Agency (EPA) and the
Virginia Department of Environmental Quality (VDEQ), issued a Proposed Plan on September
13, 1998, presenting the prefened remedial alternative for OU-424, The Proposed Plan and the
supporting documentation were made available for review at that time and are among the docu-
ments which comprise the CERCLA Administrative Record for the OU.
\, .'
The Administrative Record is available for review by the public at the following information
repositories: .
:~
.
Hampton Public Library
Reference Section, Langley AFB Information Repository
4207 Victoria Boulevard
Hampton, Virginia 23669
(757) 727-1154
Langley AFB
Administradve Record Room
37 Sweeney Blvd.
BuiIding No. 328
Langley AFB, Virginia 23665-2107
(747) 764-1046 .
.
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An announcemenrfor a public ~eeting. the comment period. and the availability of the Proposed
Plan and supporting documentation was published in the Daily Press, a newspaper of general
circulation in Hampton, VA. on September 6, 1998. Additionally, this information was pub-
lished in the Flyer. a Langley Air Force Base newspaper. on September 11, and September 18,
1998. This meeting was also announced at the previous Restoration Advisory Board Meeting,
held on June 25, 1998.
The public comment period for the Proposed Plan was from September 13, 1998 to October 12,
1998. A public meeting was held at the Virginia Air and Space Center's Library in Hampton,
Virginia, on September 24, 1998 to infonn the public of the proposed no action alternative and to
seek public comment. . At this meeting, representatives from Langley AFB, EP A, and VDEQ
were available to answer questions about conditions at OU-42 and the no action proposal for the
soil for the OU. Responses to the comments received during this period are included in Section
vm (Responsiveness Summary) of this Record 0/ Decision (ROD).
This ROD presents the selected remedial action for OU-42 which was selected in accordance
with CERCLA and, to the extent practicable. the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP). All documents considered or relied upon in reaching the
remedy selection decision contained in this ROD are included in the Administtative Record for
the OU and can be reviewed at the information repositories.
IV.
Scope and Flol. of Operal2ltLUnJl
This ROD describes the no aCtion alternative selected for OU-42. This ROD addresses only the
soil at OU-42. The groundwater at OU-42 is being investigated separately under CERCLA and
will be addressed in a future ROD.
This document is the result of a Langley Partnership Team effort. The Langley Partnership, the
IRP decision-making body, is composed of representatives from EP A Region m. VDEQ, the
U.S. Air Force Air Combat Command, Langley AFB. the U.S. AImy Corps of Engineers. and
environmental consultants.
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v.
Summary of S~aracterlstlC8 ancU:xtent of ContamUlltism
Summarized below are the relevant findings of the work to date with regard to contaminated soil
located within the boundaries of OU-42.
A.
Site Characteristic.
The current land use of OU-42 is open space and recreational with the surrounding land use
being mainly industrial. Area A is located near the RV storage yard and nonh of the main.
runway. Area B is located north of the flightline and is bordered by a jogging trail to the south
with a playground. ballfield, and riding stables over 800 feet to the northeast and northwes~
respectively. The land use of these areas is likely to remain the same; the 00 is unlikely to be
used for futUre residential use. However, the risk assessment conducted as part of the RI .
evaluated both recreational imd residential human receptors should the current land use of the
OU change.
The informarion below describes the land and groundwater resources available at OU-42.
1.
Geology
The following geologic infonnation was taken from the SI Reporr. Surficial deposits (typically
within the upper 5 feet) at Langley AFB consist mainly of Holocene alluvial deposits. These are
pri~arily sandy, silty clays or silty, clayey sands. These sediments were deposited within the
flood plains of the James, York. and Back Rivers during a period of higher sea level stands.
There are also localized deposits of organic-rich soil, which were deposited in an estUarine or
lagoonal environment. Fill material exists in several areas of the base, especially in the areas
adjacent to the southwest branch of the Back River. where fill was used to stabilize the shoreline.
This fiU material is often similar to the native materials (due to its being derived from nearby
borrow sources) and may contain gravel, rubble. and other construction debris.
The surficial deposits at Langley AFB are underlain by over 2,000 feet of sediments that range in
age from early Cretaceous to Holocene. These overlie a pre-Cretaceous basement complex con-
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sisting of sedimentary rocks together with granites and diorites. The basement complex is
approximately 2.200 feet below the land surface at Langley AFB.
The Cretaceous deposits beneath the base occur at depths of approximately 700 to 2,200 feet
. below ground surface, and consist of discontinuous sand layers interbedded with silts and clays.
The deposits are divided into tWo units: the Potomac Group (Lower Cretaceous) and the
Manaponi Fonnation (Upper Cretaceous). These Cretaceous deposits fonn the Principal Aquifer
in Virginia, which yields large quantities of water in the Williamsburg and Yorktown areas.
The Cretaceous deposits are overlain by Paleocene sediments. consisting of fme to medium-
grained sand interbedded with silty clays. These deposits are divided into three sttatigraphic
units:
.
The Glauconitic Member of the Manaponi Formation (oldest);
The Aquia Fonnation; and
The Nanjemoy Fonnation (youngest).
.
.
Strata of Eocene Age are divided into the Nanjemoy and Chickahominy Formations: however,
these deposits are either thin or absent beneath Langley AFB.
Miocene deposits overlie the Paleocene strata beneath the base, and occur.at depths of
approximately 40 to 600 or 700 feet below land surface. They are divided into three units:
.
The Calvert Fonnation (oldest);
St. Mary's Formation; and
Yorktown Fonnation (youngest).
.
.
The top part of the Miocene consists of shelly sediments cemented with calcite. These grade
downward into a fine-grained quartz sand with decreasing shell content. The sands contain
traces of biotite and glauconite.
The Miocene deposits are overlain by Pliocene sediments belonging to the Yorktown Fonnation.
The formation consists of bluish-gray to greenish-gray. fossiliferous silts and fine sands with
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localized shell beds and clayey s.ilt lenses. Previous borings at Langley AFB encountered Y ork-
town formation deposits to a muimum depth of 17 feet below ground surface; however, the
borings did not penetrate through the fonnation'. The deposits consisted of clayey sands and
silty sands. A progressive downward color change from yellow-brown to bluish-gray was
attributed to decreased weathering effects with depth.
The uppennost stratigraphic unit that occurs beneath the base is the Lynnhaven Member of the
Tabb Fonnation (pleistocene). This member is made up of a range of sediments. including
estuarine clays, silt deposits. and sand and gravel beach deposits. Previous borings at the base
encountered from 2 to 6 feet of Tabb Fonnation sediments. consisting primari1y of brown clayey
sands' .
2.
Hydrogeology
There are three aquifer systems within the Coastal Plan sediments beneath LangJey AFB: 1) the
Shallow Water Table Aquifer, 2) the Upper Artesian Aquifer system; and 3) the Principal Arte-
sian Aquifer system. None of these aquifers are used as sources of drinking water for LangJey
AFB because saltwater intrusion from the nearby Back River causes very high chloride concen- '.
trations in the groundwater. Even though the groundwater in this area is not used as a source of
drinking water, individual homeowners have groundwater wells that have been used for watering
lawns and washing cars. However, the Shallow Water Table Aquifer provides an important
source of drinking water farther to the west in King Williams, Charles City, New Kent. James
City, and York Counties. In Newpon News and Hampton. there are areas where domestic
groundwater is obtained from wells that range from 50 to 100 feet in depth. These wells are pro-
bably completed in the Shallow Water Table Aquifer, which ranges from 5 to 100 feet below
land surface).
. t .. ~ "- .
.' ,
3.
Meteorology .
The climate at OU-42 is influenced by Chesapeake Bay and the Atlantic Ocean to the east and by
mountains to the west. Mild winters and warm. humid summers are the nonn: Wintertime temp-
eratures range from the 30s to near 50°f; summertime temperatUreS range from approximately
70 to the 80s.
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Precipitation at OU42 reaches. maximum amounts inJuly and August. with minimum amounts
in November and April; the annual average is 44.1 S inches. In a given month, the average
. .
number of days with precipitation ranges from 7 to 11. In a given year, the average number of
days with precipitation is 110. Snowfall averages 10 inches per year but is highly variable,
ranging from 0 (0 45 inches.
With an average wind speed of roughly 5 to 8 knotS, the prevailing winds are south-southwest in
- April through May, southwest in June through September, and nOM in October through March.
4.
Ecology
Both Area A and Area B of OU42 are presently well-maintained grass lawns. These areas are
small, less than an acre each, so ecological habitat is limited and of poor quality. OU-42 is con-
sidered terrestrial habitat only; there are no surface water bodies associated with the OU. The
level of human activity preventS the OU from being used as an ecological habitat. However,
small mammals (e.g., voles and mice) and passerine birds may use the area to forage for seeds
and invertebrates at the QU.
5.
Solis
Soils occurring at the surface consist of siJty, clayey sands, with a low to moderate permeability.
Contaminant migration via soil. QU-42 would be slow because of the low permeability and
low hydraulic gradienr. OU-42 is flat and covered with vegetation (i.e., grasses) that would
. .
prevent contaminant migration via wind-blown dust and surface runoff.
B.
Nature And Extent Of Contamination
The SI consisted of drilling and sampling three soil borings in each area, installing one monitor-
ing well in each Ilea and collecting one sample from each of the wells. In 1998, the RI was
performed; it. consisted of the following samples: 1) tWo samples each from the existing moni-
toring wells, 2) direct push soil samples from three locations at each area, and 3) one deep direct
push water sample. The RI data received Level IV data validation and therefore was used in a
baseline risk assessment for OU-42. .
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The following is a summary of ~e sampling results of these investigations. Because this ROD
addresses specifically the soil at OU-42. only the soil results are presented below.
1.
OT -38 Area A
For the SL three soil borings were taken and analyzed for Resource Conservation and Recovery
Act (RCRA) metals. extractable pettoleum hydrocarbons. polychlorinated biphenyls (PCBs).
volatile organic compounds (VOCs). and SVOCs. Metals. VOCs. and SVOCs were detected in
the soil samples at Alea A. The screening assessment identified metals and SVOCs as the
COPes for Area A.
For the RI. three direct push locations were sampled at OT-38 Area A. Two soil samples were
collected from each location. Figure 3 shows the location of the direct push samples. Direct
push soil samples were collected from just below the surface (0 to 2 feet) and from j~t above the
water table (2 to S feet). The samples were analyzed for organochlorine pesticides and PCBs.
chlorinated herbicides. VOCs. SVOCs. polychlorinated dioxins and furans. metals. and total
cyanide.
... . :.,.
The near-surface (0- to 2-foot) soil samples from both of the direct push soil locations contained
dieldrin in concentrations up to 128 J1gllcg. a concentration which exceeds the dieldrin risk-based
screening level (RBSL) of 40 J1g1kg. The sample from location DPS3 (0 to 2 feet bgs) contained
6,020 nglkg 1.2.3.4,6.7.8-0CDD. above the RBSL of 4.300 nglkg. No background upper toler-
ance limit (UTI..) for OCDD was determined. Figure 4 presents the location of these samples and
the concentrations of dieldrin and OCDD.
. .
Benzo(a)anthracene. fluoranthene. and mercury exceeded the background subsurface soil UTLs.
but were lower than their corresponding RBSLs. Several of the direct push soil samples con-
tained aluminum. beryllium. chromium. iion. manganese. and vanadium at concentrations greater
than the RBSu, but each of these metals is present in concentrations below background UTLs
and are not attributable to OU contamination.
VOCs. PCBs. herbicides. and cyanide were not found at concentrations exceeding either the
RBSLs or background UTLs in any of the direct push soil samples.
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2.
OT -38 Area B
For the SI. three soil borings were taken and analyzed for RCRA metals. extractable petroleum
hydrocarbons, PCBs, VOCs, and SVOCs. Metals, VOCs, and SVOCs were detected in the soil
samples at Area B. The screening assessment identified several metals as the COPes for Area B.
For the RI. three direct push locations were sampled at OT-38 Area B. Two sOil ~ples were
collected from each location. Figure 5 shows the location of the direct push samples. Direct
push soil samples were collected from just below the surface (0 to 2 feet) and from just above the
water table (2 to 5 feet). The samples were analyzed for organochlorine pesticides and PCBs,
chlorinated herbicides. VOCs, SVOCs. polychlorinated dioxins and furans, ~etals. and total
cyanide. .
The only metal that exceeded the background subsurface soil UI'L in the direct push samples was
mercury. The direct push near-surface (0 to 2 feet) soil samples contained up to 0.0443 mgllcg
mercury. and the subsurface (greater than 2 feet) samples contained up to 0.0377 mgllcg mercury,
exceeding the background UTI.. of 0.0294 mglkg but below the RBSL of 0.78 mglkg. Several of
the direct push soil samples contained aluminum, arsenic. beryllium, chromium, iron, manga-
nese, and vanadium at concentrations greater than the RBSLs, but each of these metals is present
in concentrations below background ~ and is, therefore, not attributable to site contamina- .
tion.
Pe~ticides, SVOCs, VOCs, PCBs, polychlorinated dibenzo-p-dioxins (PeDDs), polychlorinated
dibenzofurans (PCDFs). herbicides, and cyanide were not found at concentrations exceeding
either the RBSL or background un.s in any of the direct push soil samples.
3.
Contaminant Fate and Transport
Only groundwater fate and transport modeling was conducted for OU-42 in the RL Since this
ROD addresses only soil for OU-42, fate and transport modeling results will be presented in the
ROD addressing Basewide groundwater.
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VI.
Current and PotenttllFuture Site and 8esource Uses
CUITent land use at OU-42 is classified as open space. and recreational. Future land use is
expected to remain open space and recreational. There are currently no restrictions regarding use
at aU-42, such' as fences and signs. Land adjacent to aU-42 is currently industrial, open space
and recreational. Future adjacent land is expected to remain the same. .
VII.
A risk assessment was conducted in the RI in accordance with the latest EP A policy on risk
assessments6. The results are summarized below.
A.
Human Health Risk Asse8.ment
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 non-carcinogenic risks
were evaluated as pan of the risk assessment; three factors were considered:
1. NatUre and extent of contaminants at the. au;
2. The pathways through which human and ecological receptors are or may be exposed
to those contaminants at the au; and
3. Potential toxic effects of those contaminants.
For this OUt surface water and sediment were not evaluated because human health and ecologi- .
cal receptors are not exposed to this medium at this OU. Groundwater was addressed for the
human health receptors. but groundwater results will be presented in a separate ROD.
Health risk levels. determined using EP A guidance to ensure that conservative estimates of
potential health effects are detennined, differ depending on the assumed land use because human
exposure differs with land use. A conservative estimate of risk was developed. incorporating the
potential exposure pathways of direct skin contact with contaminated soil. accidental ingestion of
soil. and inhalation of contaminated particles. Plausible receptors that may be exposed to soil at
the site and which were evaluated in the risk assessment included a groundskeeper and an on-site
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resident (both child and adult e.xposure). Table 2presents the exposure parameters and equations
used to calculate risk levels for .these receptors.
Cancer risks are expressed as numbers reflecting the increased chance that a person will develop
cancer. if he/she is directJy exposed (e.g.. working at the OU) to the contaminants found in the
soil over a period of time. For example. EP A' s acceptable risk range for cancer is 1 x 1 O~ to I x
1 O~. meaning there is one additional chance in ten thousand (I x 1 cr ) to one additional chance
in one million (I x 1 ~ ) 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 (HI). A
hazard index of less than one 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.
Concentrations of chemicals detected in the soil during the RI were compared to RBSLs and
background levels. Chemicals that exceeded the screening levels were then used to calculate risk.
COPCS identified in the surface soil for OT-38 Area A were 1.2.3.6,7,8,9-OCDD and dieldrin;
for subsurface soil. the COPCS identified were aluminum. iron. and vanadium. OT -38 Area B
surface soil COPCs were identified as vanadium and aluminum; no COPCs were identified for
OT -38 Area B subsurface soils.
Table 3 presents the risk results of the human health risk assessment for OU42. The human
health risk assessment concluded that the lifetime cancer risks to the receptors from exposure to
pesticides and metals in soil at OT-38 Area A is 7 x 10~ for the adult on-site resident. This
lifetime risk is within EPA's acceptable risk range. The HI for the non-carcinogenic risks due to
exposure to pesticides and metals in soils at OT-38 Area A is 0.12 for the groundskeeper and
0.02 for the on-site child iesidenl These values are below the acceptable level of 1.0, indicating
. that adverse non-carcinogenic health effectS are unlikely to develop as a result of exposure
through any of the exposure pathways.
No lifetime cancer risks exist tome receptors from exposure to metals in soil at OT-38 ~a B.
The HI for the non-carcinogenic risks due to exposure to metals in soils at OT-38 Area B is 0.07
for the groundskeeper and 0.3 for the on-site child resident. These values are below the accepta-
12
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ble level of 1.0, indicating that ~verse non-carcinogenic health effects are unlikely to develop as
a resuJt of exposure through any of the exposure pathways.
Ecological Risk Aaae..ment
The ecological risk assessment evaluated exposure of terrestrial receptors to soil. Both Area A
and Area B of the site are small (less than one acre) and are maintained grass lawns which pro-
vide only limited ecological habitat. No surface water or sediment exposure pathways exist at
the site.
Only lead and dieldrin exceeded the HI of 1 for both areas. Upon funher analysis, the HIs for
lead and dieldrin dropped below an HI of 1.0 when the Lowest-Qbserved-Adverse-Effect-L.evel
toxicity data were used instead of No-Observec1-Adverse-Effect-Level toxicity data. Results
indicate that there is minimal risk to terrestrial receptors at the site.
Conclusions
After evaluating the RI human health and ecological risk assessmentS, no action is considered
necessary to protect human health and the environment at OU-42. The human health risk calcu-
lated under the current and future land use scenarios for Area A of OU-42 is within EPA's accep-
table risk range, and Area B of O~-42 is below the EPA's acceptable risk range. Any adverse
non-carcinogenic health effectS are also unlikely to develop from the site as a result of exposure
thr~ugh any of the exposure pathways. Ecological risk assessment detennined that there is mini-
mal risk to terrestrial receptors at the site.
..'" ;
With the .support of EP A andVDEQ, Langley AFB has selected no action as the preferred alter-
native for soil at OU-42; under this alternative, no remedial action would be undertaken there.
The selection of no action is based on the conclusion, reached by the human health and ecologi-
cal risk assessments, that the soils at the tWo areas comprising OU-42 pose no significant risk to
potential human or ecological receptors; no action therefore would be protective of human health
and the environmenL
13
-------
Following review and consident.tion of the infonnation in the Administrative Record. the require-
ments ofCERCLA and the NCP, and public comments received on the Propos~d Plan. Langley
AFB and EP A, in consultation with VDEQ, have selected the no action. alternative as the remedy
for OU-42.
VIII.
No significant changes were made from. the Propos~d Plan as a result of public review during the
comment period or public meeting.
1)(,
.Responsiveness Summary
A.
Overview
In the Propos~d Plan released for public comment on September 13, 1998, Langley AFB. with the
suppon ofEPA and VDEQ, identified no action as the preferred remedial alternative for OU-42.
The no action alternative is described in the "Summary of the Proposed Remedy" in the Propos~d
Plan.
There were no written comments received as a result of the public comment period. There were
no written comments submitted during the September 24, 1998 public meeting. There was one
question presented orally at the public meeting concerning OU-42. The comment and the associ-
ated response of Langley, EPA, and VD£Q i~ provided below after a brief description of commu-
nity involvement to date.
B.
Community Involvement 10 Date
Langley, EPA. and VDEQ established a public comment period from September 13, 1998 to
October 12, 1998 for interested parties to comment on the Propos~d Plan. The plan and all other
- .
documents considered or relied upon during the remedy selection process for the no action alter-
native are included in the Administrative Record, which is available for public review. A public
meeting was held at the Virginia Air and Space Center, Hampton, Virginia. on September 24.
14
-------
1998 to present the proposed pl~. answer questions. and accept both oral and written comments
on OU-42. Two people attended.the public meeting.
This responsiveness summary. required by CERCLA. provides a summary of citizen comments
made during the public meeting and the responses of Langley AFB. EP A. and VDEQ.
Responses to these coinmentS are included in the section below.
c.
Summary Of Comments Received During Public Comment Period and
Comment Response.
In the public meeting held on September 24. 1998. two proposed plans for Langley AFB were
presented. One was for OU-42 (Waste Oil and Trash Bum PitS). and the other was for OU~7
(the Former Elecaical Substation Site). Following is the only comment which penained to OU-
42:
Comment # I:
What is each of your backgrounds and what kind of experience do you have to be in the positions
that you are in?
Response # 1:
The EP A representative stated that she has been working with Federal CERCLA sites. including
other DOD installations. for six years. .
The VDEQ representative stated that he had been working with Federal CERCLA sites.
including other DOD installations, for six years.
The Langley representative swed that he had been working in the Air Force environmental
program for twelve years.
Each of the representatives stated that they had college degrees in disciplines related to their
current positions.
15
-------
APPENDIX A
Tabl..
-------
(0
Table 1. Summary of Operable Units Under CERCLA Inve.tlgation
Page 1 of 2
OUNamellRPSiteName FiDdiap ClU'l"eDt Statui
OU-21/LF-Ol Conlaminants of Potential In the remedial investigaIion (RI) phase. A
Former Landfill. End of 08126 Concern (COPes) - pesticides draft RI report has been submiaed and
Runway and mews in the groundwater reviewed. A separate basewide ecological
and soil. risk assessment is currently underway.
OU-22/WP-02 COPes - pesticides and metals in In the RI phase. A draft RI report will be
Former Waste Water Treatment the groundwater and soil. submiaed by mid-1m.
Plant. HTA Area. Bldr 724
OU-23/LF-OS COPes - pesticides. VOCs. and In the RI phase. A draft RI report has been
Former Landfill in the $hellbaDk metals in the groundwater. submiaed and reviewed. A separate
Area pesticides and metals in the basewide ecological risk assessment is
surface water, and SVOCs and currently underway. .
.
metals in the soil.
OU-24/0T.()6 COPes - pesticides. VOCs. In the RI phase. A draft RI report has been
Former Entomology Site. SVOCs. and some metals in the submitted and reviewed. A separate
ShellbanJc Area . groundwater. SVOCs. pesticides basewide ecological risk assessment is
and some metals in the soil. currently underway.
OU-25/LF-07 COPes - pesticides and some In the RI phase. A draft RI report has been
Former Landfill. Shellbanlc Area metals in the groundwater. submitted and reviewed. A separate
dieldriD in the soil. basewide ecological risk assessment is
currently underway.
OU-26/WP-08 COPes - some pesticides and In the RI phase. A draft RI report has been
Former Waste Water Treatment metals in the groundwater. submitted and reviewed.
Plant. L T A Area dieldriD in the soil.
OU-281LF-I0 COPCs - VOCs. metals and some In the RI phase. A draft RI report has been
Fonner Landfill. Golf Course pesticides in the ground water, submitted and reviewed. A separate.
VOCs and PCBs in surface water, basewide ecological risk assessment is
some metals in the soil. currently underway.
OU-29/LF-ll COPes - VOCs. pesticides. In the RI phase. A draft RI report has been
Former Landfill. Tabbs Creek metals and PCBs in the submitted and reviewed. A separate
Area groundwater, some metals in the basewide ecological risk assessment is
surface warer; SVOCs. metals and currently underway.
PCBs in the soil.
OU-301LF-12 COPes - VOCs and mews in the In the RI phase. A draft RI report has been
Fonner Landfill. Munitions groundwater; mews and 2.4-DB submitted and reviewed. A separate
Storage Area. Northwest Area of in the surface water, SVOCs anJ basewide ec;ological risk assessment is
Base nicltcJ in the soiJ. currently underway.
OU-311LF-13 COPCS - Aldrin. alpha-SHC and In the RI phase. A draft RI report has been
Former LandtilI. Munitions some metals in the groundwater. submitted and reviewed. A separate
Storage Area. Nonbwest Area of VOCs. SVOCs. metals and PCBs basewide ecological risk assessment is
Base in the surface water. currently underway.
OU.321WP.14 COPCs - pesticides. SVOCs. and In the RI phase. A draft RI report has been
Former Chemical Leach Pit. some meca1.s in the groundwater, submitted and reviewed. A separate
Firing-In Abuanent. Building arsenic and dieldrin in the soil. basewide ecological risk assessment is
1303 currently underway.
OU-33/LF-JS COPCs - VOCs. SVOCs. In the RI phase. A draft R1 repon has been
Former Landfill. Willoughby pesticides. and metals in the submitted and reviewed. A separate
Point groundWater. pesticides and basewide ecological risk assesSment is
metals in the surface water. currently underway.
-------
t,;
Table 1. Summary 01 Operable Units Under CERCLA Investigation
Page 2 of 2
OU NameIIRP Site Name Findings Cumnt Status
OU-34/LF-17 : COPCs - VOCs. pesticides and In the RI phase. A draft Rl repon win be
Former I...andfiH. Lighter Than Air some metals in the groundwater. submiued by mid-l 999 .
.-\rea dieldrin and some metals (mainly
lead) in the soil.
OtJ-3SILF-18 COPCs - pesticides in the In the RI phase. A draft Rl repon has been
Forme:- Landfill. Northwest groundwater. pesticides and subrruned and reViewed. A separate
C"mer of Base metals in the surface warer; base",de ecological risk assessment is
SVOCs and manganese in the cWTently underway.
surface soil; deita-BHC and
metals in the sedimenL
OU-37/LF.22 COPCs - pesticides and mews in In the Rl phase. A draft Rl report has been
Fonner l..4ondfill. WilJougbby the groundwa1et; alpha-BHC. submiucd and reviewed. A separate
Potnt deha-BHC and meWs in the basewide ecological risk assessment is
surface water. cWTently underwav.
OU-4OIOT.~ COPCs - pesticides in the In the Rl phase. A draft Rl report has beea
Old EntomololY Building and groundwater and soil. submiucd and reviewed. A separue
Former Stonge ArQ. Bldl 965 basewide ecolop:aJ risk 1S~~t is
currentlv underwav.
OU-42/OT-38A and B Risk assessments showed no In the ROD Pbasefor soils. Groundwala'
Four Waste Oil " and Tnsb Bum siSDificant risk to human bea1th or ROD wiU foUow at a later dale. The final
Areas. Basewide the environment from soils. Rl report was submitted in September
1998.
OU-441FT -41 COPes - VOCs. pesticides. In the RI phase. A draft RJ report has been
Former rare Training Ala, dioxins. ~ some metals in the submitted and reviewed. A separate
Firing-In Aburment, Bldg 1303 groundwaler; SVOCs. dioxins basewide ecological risk assessment is
and sOme metals in the surface currently undenny.
. wafer.
OU-47/OT-Sl ; COPCs - pesticides. PCBs and The RJ report and proposed plan have been
Fc.rmer EJearicaJ SubstabOD. I lead in the soil. finalized. The record of decision is due co
Shellbank Area. Blehr 82 be submitted by the end of 1998.
OU-481OT.S5 COPes - pesti~ides aDd dieldrin In the Rl phase. A dn..'t RI report is due 10
Civil Er.ginm;ing Yant. iD the groundwalCr, peSticides and be subr.uttcd by mid-I999.
Undergrouad Petroleum PCBs in the soil.
ContllmillJltioD
OU-49/OT-S6 COPes - metals and VOCs in In the feasjbility RUdy (FS) phase. The FS
Silver CODtllmi_liftft iD Storm surface wucr and metals. SVOCs. is due to be finalized by mid-I999.
Sewers. Basewide . aad pesbcides in sedimenL
OU-5M$-61 COPCs - VOCs in the In the proposed plan
-------
Table 2. Exposure Pal'8metel'8 and Equation. Used to EstImate Potential Chemical
Intak88 and Contact Ratea for Receptors at Langley AFB, VIrginia
. . Page 1 of 4
Pathway I Off-Base
- Parameter Variable Groundskeeper Resideot
dOD 01 VOCs and Resuspended Dust lrom Soil
Ia = Ca x IRa x FYa x ETa x EF x ED
BW x AT
lnhalalion Intake of COPC Ja (mglkg-day) caJculaled calculated
. D Soil
Concentration of COPC in ~ (mglm3) CSV CSV
Air
. OD Rate ~ (m3Jbour) 2.S. NA
Fraction of Exposure . lFIa (unitJess) IC NA
AaribUted 10 Site Medium
Exposure TUDe !ETa (hours/day) Sd NA
Exposure Frequency rEF (dayslyear) sac NA
Exposure Duration lED (years) RME:25& NA
cr:~
Body Weight IBW (kg) 70& NA
A. veraging Time (non- !AT NOlKancer (days)e RME: 9.125 NA
~arcinogens)
cr: 3.2SS
~ veraging Time !AT Ca.ncer (days)! 2S,SSO NA
It carcinogens)
tallDaestioD of Soil
Xs=Cs x IRs x Fls x EFx ED x CF4
BW x AT
Ingested Intake of COPC in [s (malkl-day) caJcuJared calculated
Soil
ConcentradoD of COpe in CJ (ma/kg) CSV CSV
Soil
Conversion Factor CF4 (kaI1DI) IE-06 I E-06
Xngestion Rare of Soil [Rs
-------
Table 2. Exposure Para..tera and Equations Used to EstImate Potential Chemical
Intakes and Con~ct Rates for Receptors at Langley AfB, Virginia
Page 2 of 4
Pathway Off-Bue
- re Parameter V.riable GroaadskeeDel' ResideDt
Exposure Frequency EF (days/year) sOC 3508
234b
Exposure Duration ED (years) RME: 25a Child RME: 61
Cf:9i Child Cf: I.Si
,
Body Weight BW (kg) 70& Child 15g
Averaging Time (non- AT Non-cancer (days)c RME: 9.125 Child RME: 2.190
"arcinogens) CI': 3.28S Child Cf: 653. -
Avenging Time AT Cancer (days; 15.550 25.5S0
carcinogens)
IDddeDtailDaesdOD of Soil (A,e-AdJasted Resident - Caacer E,.81uado.
[s = Cs x IFSadi x EF x CF x Frs
AT
Ingested Iolab of COPC in Is (mglq-
-------
Table 2. Exposure P....rnet8r8 and Equations Used to Estimate Potentia' Chemical
Intak.. and Contact Rates for Receptors .t Langley AFS, Virginia
. Page 3 of 4
Pathway OtI'-Bue
Parameter Variable Groundskeeper ResideD.
Surface Area of Skin SA (cm2) 2000b quId RME: 1825c
~ vailable for Contact with Child Cf: 1825c
Soil .
~xposure Frequency EF (days/year) sac RME: 3Soa
CT: 234b
~posure Duration ED (years) RME: 25a . RME:6
CT:9i Cf: 1.8
~Ody Weight BW (kg) 70a ISc
SoiJ-tc>Skin Adhcrence iAF (mglcm2) 0.2h 0.2b
r= actor
Absorption Fracaon ~S (unidcss) Csv CSV
Averaging Time (non- !AT Non-canccr (days)c RME: 9.125 RME:2190
arcinogcns) . .
CT; 3,285 CT:S7
Averaging Time !AT Cancer (days)f ZS,SSO NA
carcinogens)
Dermal Contaca with Soil (Ap-Adjusted ResideD. - Cancer EvaluatioD)
DAD = Cs x SFSadi x ABS x AF x EF x CF x Ad
AT
~ vcragc dermally absorbed IDAD (mglkg-day) NA calculated
dose of COPe
Concentration of COPe in ICs (milk,) NA CSV
Isoil
~gc-adjusted Skin ContaCt ~FSadj (cml-yrJkg-day) NA RME: 2720
CT: 730
~bsorpaon FracaoD ~S (uDidcss) NA CSV
Skin-te>Soil AdhcmIce iAF (mglem2) NA 0.2h
FactOr
Exposure ~DC)' ~ (dayslyr) NA RME: 3Soa
cr: 2341
~onvcrsioD Factor ~ (kg/m,> NA lE-06
I:raction of Exposure IFId (uDidess) NA 1
~nributed to Site Medium
A veragjng Time !AT Cancer (daysf NA 25.550
carcinogens)
\.. _,0
''0
-------
Table 2. Exposure Parametel'8 and Equation. Used to estimate Potential Chemical
Intak.. and Conflict Rat.. for Receptora at Langley AFB, Virginia .
. Page 4 014
NA. not app)jc:ab~ CSV ::8 cbemica1-specific value; RME . reasonable maximum exposure; cr = centtal tendency
a RisJc AsUSSl'flDtl Guidance for S&t.perfttNJ Volwu I: HII1fVIII Health Evahuuiort MtlNMJl Supplmr.trtual Gwid.tmce.
SIlZNIiud Dqcudt Ezposun Faaon. Interim rmal. UuS. Environmental Protection Alene,. Office of Solid W~
and Emergency R.esponse. OSWER Directive: 9285.6-03. 1991.
b Ezposun Faaon HtJ1UiJHJok. Office ofHea1tb aDd Environmental Assessment. Washington. DC, EPAJ6OOI8-
891043. U.S. Environmental ProtectiOD Aptt:y. 1990.
c As5umed, see RDMdiIU InwstigtJdtm Repon for IRP SiU OT-38A. tIIId B. Draft FiMI, Langlly Air Force BlUe,
Virgillia. Radian Inrematioul, May 1998.
d Default value based Oft COQverwioD with EPA Rqion m and VDEQ. Site.specific evaluatioa may be used to
justify a differeD' exposure time.
e Calcul8led as the prodw:t of ED (years) It 365 days/year.
f Calculated as the product of 70 years (assumed human lifetime [Risk AssesSIPII1II Guidancefor SIIpDfuNI. Vol,.".. 1.
HIIIMII He4ltI8 EvallMJl:U1l1 MiZ1UIIIl (Pan A), Interim Final, U.S. Environmental Protection Agency. Office of
Emergeaey lOCI Remedial Response. Washington. DC. EPAJS4OI1.8IOO2. 1989]) It 365 dayslyear.
g Risk.Based ConcmtrrJliorl TabZ., March 14, 1997, EPA Region In, Philadelphia. PA. on-line.
h DemuJl ExpoSJUe Asse.s.smcnt: Prindplu aNJApplictUiDlLJ.lnterim R.epon.. U.S. Envirionmental ProteaiOD
Agency. Office of Research and Development. Washington, DC, EPAJ6OOI8-91101IB. including Supplemeatal
GuidaDc::e dated August 18, 1992.
i Attacltnwnt 2. S&t.pe1fu1uJ's SuuuJard DeftUlb Ezposun Factors for tM Central TendDu:y tIIId Ruuoraabk MGZimum
Exposun. Preliminary Review Draft, U.S. Environmental Protecton Agency, May S, 1993.
j FJ::8 1 unless site-specific coDsideralioas iodicare that exposure to more than one potentially COfttamiJWeci medium
is applicable. For examplc. if a tecepcor is aposed to tWO potenually conUinftf'ltotM media. F1 ;0 0.5. In addition. ,
some smaller poniOD of me ISS"JIIed intake may be aaributable to con.taminarcd media. -. therefore. FJ may vary.
as described iD tal.
Note:
'Ibis tabJe presems the variables used to eslimare potenlia1 chemical intakes aNI c:omact tala (or ~gIey AFB. This
table is DOt specific: to any IRP site aDd does DOt represent exposure scenarios for my site.
-------
Table 3. Human Health Risk AI....ment Summary for OU-42 (OT -38 Area A and Area B)
Media 01 CoDCel'll GroaaclskeeDer Adult ResideDt CbJId Residaat
OT-38 Area A ReceDtor Hazud lades
Surface Soil - NA 0.02
Subsurface Soil 0.12 NA NA
OT-38 Ara A Caacer Risk
Surface Soil - 7E-06 NA
SubsurfKe Soil NC NA NA
OT-38 Ara B Receptor Hazard IDda
SurfK«: Soil <0.1 NA 0.3
Subsurface Soil NC NA NA
OT-38 Ara B Caacer Risk
Surface Soil NC NC NA
Subsurface Soil NC NA NA
NA = Not applicable; pathway not evaluated
NC = Not calculated; chemical-specific factor(s) not available.
.. = Palhway evaluated; risk value is < 0.001 (Hazard Index) or lE-06 (Cancer Risk).
-------
APPENDIX B .
Figures
-------
\. \J
~ - . j-- --. /" \)
) ( ." rj
CHl SAPI AJ(( /JAr
Figure 1. LocaUon Map, Langley Air Force Ba., Virginia
.r-
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fig'" a. .,.,..,... 01 Ung", Al'B Showtngll18 LOC8IIon 01 ... 511.
/OT.. AIM A IIICI AIMIIIOU-42I and CERCLA au.
-------
roUMER lOCATION or /-1
UNPAVED ACCE~S ROAO~ I
I
I
J
I
f()I
-------
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~
IO'lMlW I UCAIION or ll. I . J
SOUAI~[ S muc IURf .A--
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(;\I~CUI AR un 'H[ S~I()N
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UNPAVED ACCESS ROAD ---- I
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'\.. CIf
-------
EXPLOSIVE SAFETY
CLEAR ZONE
"
~4>
"V
-------
APPENDIX C
Glosaary
-------
AdmfniqnUve Record: A collection of documents containing all the information and reports
generated during the entire phase of investigation and cleanup at the site and used to make a deci-
sion on the selection of the preferred alternative under CERCLA.
Carcinogenic Risk: Cancer risks are expressed as numbers reflecting the increased chance that
a person will develop cancer if exposed to chemicals or substances. For example, EP A's accepta-
ble risk range for Superfund sites is 1 x 1~ to 1 x 1
-------
Installation Restoradon Propam (IRP): Program established by the United States Air Force to
systematically identify and remediate contaminated sites. The IRP was designed to be consistent
with EP A rules and guidelines.
Lowest-Observed-Adverse-Efrect Level (LOAEL): The lowest exposure level at which there
are statistically or biologically significant increases in frequency or severity of adverse effects
betWeen the exposed population and its appropriate control group.
No-Observed-Adverse-Efrect Level (NOAEL): An exposure level at which there are no statis-
tically or biologically significant increases in the frequency or severity of adverse effects betWeen
the exposed population "and its appropriate control; some effects may be produced at this level, .
but they are not considered as adverse, nor as precursors to adverse effects. In any experiment
with several NOAELs, the regulatory focus is primarily on the highest on~, leading to the com-
mon usage of the term NOAEL as the highest exposure without adverse effect.
Operable Unit (OU): A discrete portion of a site or a discrete action representing an incremental
step in the investigation and remediation of hazardous substances at a facility. "
Proposed Plan: A document that presents a proposed cleanup alternative and requests public
input regarding the proposed alternative.
Record of Decision (ROD): A legal document that describes the cleanup action or remedy
selected for a site, the basis for the choice of that remedy, and public comment on alternative
remedies.
Remedial Action: Implementation of plans and specifications, developed as pan of the design, to
remediate a site. "
RemediallDvestlpdon (RI): Part of a study of a facility that supports the selection of a remedy
for a site wh= hazardous substances have been disposed. The RI identifies the nature and
extent of contamination at the facility.
Site: The facility and any other areas in close proximity to the facility where a hazardous sub-
stance, hazardous waste, hazardous constituent. pollutant. or contaminant from the facility has
been deposited, stored, disposed of, or placed or has migrated or otherwise come to be located.
-------
Site IDspectiOD (Sn: The 51 de~nes if the site presents an immediate threat that requires
prompt response action because the site may pose a threat to human health anellor the environ-
menL
Site-Related Risk: Cancer and non-cancer risk estimates that are based on contaminants present
in environmental media due to site-specific human activities at Langley AFB. but that exclude
the contribution of background contaminant concentrations.
SuperfuDd AmeDdments and Reauthorization Act (SARA): An amendment to CERCLA
enacted in 1986.
-------
APPENDIX D
References
I
I.
-------
1.
R~medialInv~mgation R,~portfor IRP Sit~ OT-3M'and B, (draft final), Langley Air
Force Basa, Virginia. Radian IntemationallLC, May 1998.
2.
InstallDtitm R~storation Program R~cords Search for Langley Air Forc~ Bas~, Virginia.
Gainesville, Florida. CH2M Hill, June 1981.
3.
Installation R~storation Program (IRP) Sit~ Inspection and Screening Risk Assessment
Report for 33 IRP Sites [draft]. Radian Corporation, February 1996.
4.
No Action Propos~d Plan for: OU-42 (OT-38 Ar~as A and B), Langley Air Forc~ Base
[final]. Langley' AFB, September 1998.
S.
FinDl Sit~ Inv~stigation R~port for Sit~ Inv~stigations at Four IRP Sit~s, Langley Air
F orc~ Bas~, Hampton, Virginia. Law Environmental, Inc., Government Services Divi-
sion, Kennesaw, Georgia, March 1990.
6.
RiskAss~ssmDlt Guidtmc~forS~rfund. VollUM 1: HumtUI H~alth Evaluation ManuDl..
. OSWER Directive 928S.7-01a, Office of Emergency and Remedial Response,
Washington, D.C. U.S. Environmental Protection Agency, 1989.
-------
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