EPA/ROD/R04-95/252
1995
EPA Superfund
Record of Decision:
SAVANNAH RIVER SITE (USDOE)
EPA ID: SC1890008989
OU12
AIKEN, SC
09/11/1995
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United States Department of Energy
Savannah River Site
Record of Decision
Remedial Alternative Selection
for the
M-Area West Unit (631-21G) (U)
WSRC-RP-95-626
Revision 0
August 1995
Westinghouse Savannah River Company MI«M*«
Savannah River Site
Aiken, South Carolina 29808
Prepared for the U.S. Department of Energy Under Contract DE-AC89-SR18035
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RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION (U)
M-Area West Unit (631-21G)
WSRC-RP-95-626
Revision 0
August 1995
Savannah River Site
Aiken County, South Carolina
Prepared by:
Westinghouse Savannah River Company
for the
U.S. Department of Energy Under Contract DE-AC89-SR18035
Savannah River Operations Office
Aiken, South Carolina
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Record of Decision WSRC-RP-95-626
M-Area West Rev. 0, August 1995
DECLARATION FOR THE RECORD OF DECISION
Unit Name and Location
M-Area West unit (SRS Bldg. # 631-21G)
Savannah River Site
Aiken, South Carolina
The M-Area West unit (631 -21G), is listed as a Resource Conservation and Recovery Act (RCRA) 3004(u)
solid waste management unit/Comprehensive Environmental Response, Compensation and Liability Act
(CERCLA) unit in Appendix C of the Federal Facility Agreement (FFA) for the Savannah River Site.
Statement of Basis and Purpose
This decision document presents the selected remedial action for the M-Area West unit located at the
Savannah River Site in Aiken, South Carolina. The selected action was developed in accordance with
CERCLA, as amended, and to the extent practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP). This decision is based on the Administrative Record file for this specific
RCRA/CERCLA unit.
Description of the Selected Remedy
The results of the Resource, Conservation and Recovery Act Facility Investigation/Comprehensive
Environmental Response Compensation and Liability Act Remedial Investigation, indicate that the M-Area
West unit poses no unacceptable risk to human health or the environment. Therefore, no action is needed at
the M-Area West unit. This is the final RCRA/CERCLA action for the M-Area West unit.
Declaration Statement
Based on the results of the remedial investigation, no action is necessary at the M-Area West unit to ensure
the protection of human health and the environment. Since M-Area West poses no threat to human health
or the environment, and no action is needed, the CERCLA Section 121 requirements are not applicable. This
action is protective of human health and the environment and is meant to be a permanent solution, final action,
for the M-Area West unit. No five-year remedy review is needed or will be performed.
Date Thotnas R Hccnan
Assistant Maniger for Environment Restoration and Solid Waste
U.S. Dept. of Energy, Savannah River Operations Office
. John H. Hatikinsoti, Jr.
• Regional Administrator
U.S. Environmental Protection Agency, Region IV
/f
Date R, Lewis Shaw
Deputy Commissioner
Environmental Qoality Control
South Carolina Department of Health and Environmental Control
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Record of Decision WSRC-RP-95-626
M-Area West Rev. 0, August 1995
DECISION SUMMARY
TABLE OF CONTENTS
Section Page
I. Site and Operable Unit Names, Locations, and Descriptions 1
II. Operable Unit History and Compliance History 1
III. Highlights of Community Participation 5
IV. Scope and Role of Operable Unit within the Site Strategy 6
V. Summary of Operable Unit Characteristics 6
VI. Summary of Operable Unit Risks 8
VTI. Description of the No Action Alternative 11
VIII. Explanation of Significant Changes 11
IX. References 12
List of Figures
Page
Figure 1. Location of M-Area West in Relation to Major SRS Facilities 2
Figure 2. Location of the M-Area West Unit 3
Figure 3. General Configuration of the M-Area West CERCLA Waste Unit 4
List of Tables
Table 1. Analytes Remaining After Comparison to Background -1.0 - 3.0 10
Feet Only.
Table 2 Estimated Risk-Based Concentrations - Hypothetical Future 10
Resident Adult and Child
Table3 Summary of risk assessment results for arsenic. 10
Appendix
A. Responsiveness Summary 13
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Record of Decision
M-Area West
WSRC-RP-95-626
Rev. 0, August 1995
I. Site and Operable Unit Name,
Location, and Description
The Savannah River Site (SRS) occupies approximately
310 square miles of land adjacent to the Savannah River,
principally in Aiken and Barnwell Counties of South
Carolina (Figure 1). SRS is a secured U.S. government
facility with no permanent residents. The Site is located
approximately 25 miles southeast of Augusta, Georgia,
and 20 miles south of Aiken, South Carolina.
SRS is owned by the Department of Energy (DOE).
Management and operating services are provided by
Westinghouse Savannah River Company (WSRC). SRS
has historically produced tritium, plutonium, and other
special nuclear materials for national defense. SRS has
also provided nuclear materials for the space program
and for medical, industrial, and research efforts.
Chemical and radioactive wastes are by-products of
nuclear material production processes.
The Federal Facility Agreement (FFA) for SRS lists the
M-Area West unit (631-21G) as a Resource,
Conservation and Recovery Act (RCRA) /
Comprehensive Environmental Response Compensation
and Liability Act (CERCLA) unit that required further
evaluation. An investigation/assessment process that
integrates and combines the RCRA Facility Investigation
(RFI) with the CERCLA Remedial Investigation (RI) to
determine the actual or potential impact to human health
and the environment was performed.
The M-Area West unit (631-210) is located west of the
M-Area Production Facility on a dirt road approximately
1.8 kilometers (1.1 miles) north of Silverton Road (Figure
2). There are no structures of any type located at or
near M-Area West. The only nearby man-made feature
is a dirt access road located about 9.2 to 12.2 meters (30
to 40 feet) west of the waste areas. The topography of
the unit is relatively flat with an elevation of
approximately 106.7 meters (350 feet) above mean sea
level (msl). The nearest surface water body is
approximately 304.9 meters (1000 feet) away. The unit
soils were identified as Orangeburg loamy sand (a well
drained, highly acidic soil).
The unit consists of two small areas (Figure 3). The
southern debris area covers 6.1 meters x 6.1 meters (20
feet x 20 feet) and the northern debris area (located 67.1
meters [220 feet] to the north of the southern area)
covers 3.05 meters x 3.05 meters (10 feet x 10 feet).
Several drums and other small innocuous debris were
found on the land surface adjacent to a dirt road
approximately 1 kilometer (3300 feet) west of the
M-Area production facility. The total waste at the unit
consisted of six empty 55-gallon drums, four 1-gallon
cans and a 1-gallon glass jar. The cans and the jar were
originally contained in one of the larger drums. With the
exception of a crushed drum and small amounts of metal
debris, all other materials were removed from the site in
1992 with concurrence from the EPA and SCDHEC.
The remaining crushed drum and debris will be removed
from the unit as a maintenance action.
n. Operable Unit History and
Compliance History
Operable Unit History
There is no documented information available regarding
past hazardous or non-hazardous waste disposal
activities at M-Area West. Markings on the drums found
at the unit suggest that they once contained oil and
solvents, and that they are approximately 37 years old.
There is no evidence that any recent disposal activity has
occurred or that the disposal activity was more
widespread. Also, there is no evidence of any burning or
excavation at this waste unit.
Compliance History
At SRS, waste materials are managed which are
regulated under the Resource Conservation and
Recovery Act (RCRA). Certain SRS activities have
required Federal operating or post-closure permits under
RCRA. SRS received a hazardous waste permit from
the South Carolina Department of Health and
Environmental Control (SCDHEC) on September 30,
1987. Part V of the permit mandates that SRS establish
and implement a RCRA Facility Investigation (RFI)
Program to fulfill, the requirements specified in Section
3004(u) of the Federal permit.
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Record of Decision
M-Area West
WSRC-RP-95-626
Rev. 0, August 1995
MArat
West
Figure 1. Location of the M-Area West waste unit at the Savannah River Site.
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Record of Decision
M-Area West
WSRC-RP-95-626
Rev. 0, August 1995
M-AREA
WEST
UNIT
"1500
1500
3000
SC*i£ W FEET
Figure 2. Location of M-Area West M Area.
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Record of Decision
M-Area West
WSRC-RP-95-626
Rev. 0, August 1995
30
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MQRTMiRN OEiRlS
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Record of Decision
M-Area West
WSRC-RP-95-626
Rev. 0, August 1995
Hazardous substances, as defined by CERCLA, are
also present in the environment at SRS. On December
21, 1989, SRS was placed on the National Priorities
List (NPL). A site placed on the NPL comes under
the jurisdiction of CERCLA. In accordance with
Section 120 of CERCLA, DOE has negotiated a FFA
with the U.S. Environmental Protection Agency
(EPA) and SCDHEC to coordinate cleanup activities
at SRS into one comprehensive strategy that fulfills
RCRA Section 3004(u) and CERCLA assessment,
investigation and response action requirements.
The remedial investigation for M-Area West was
completed in 1994. The results of the investigation
indicate that the M-Area West unit poses no current or
future risk to human health or the environment.
Therefore, no action is warranted at the M-Area West
unit. No other alternatives were considered. This is a
final CERCLA action.
According to EPA guidance, if there is no current or
potential threat to human health and the environment
and no action is warranted, the CERCLA 121
requirements are not triggered. This means that there
is no need to evaluate other alternatives or the no
action alternative against the nine criteria specified
under CERCLA.
Public participation requirements are listed in Sections
113 and 117 of CERCLA. These requirements include
the establishment of an Administrative Record File that
documents the selection of remedial alternatives and
allows for review and comment by the public regarding
those alternatives. The Administrative Record File
must be established "at or near the facility at issue."
The SRS Public Involvement Plan (DOE, 1994) is
designed to facilitate public involvement in the
decision-making process for permitting, closure, and
the selection of remedial alternatives.
A proposed plan (PP) was submitted that fulfills the
requirements of CERCLA Section 117(a) by providing
the public an opportunity to participate in the selection
of a remedial action. The PP presented the preferred
alternative and the rationale for selecting the
alternative. DOE, in consultation with EPA - Region
IV and SCDHEC, selected the final action for M-Area
West unit following the public comment period.
III. Highlights of Community
Participation
Public participation requirements are listed in Sections
113 and 117 of CERCLA. These requirements include
the establishment of an Administrative Record File that
documents the investigation and selection of the
remedy for addressing M-Area West. The SRS public
involvement plan (DOE, 1994) is designed to facilitate
public involvement in the decision-making processes
for permitting, closure, and the selection of remedial
alternatives. The SRS public involvement plan
addresses the requirements of RCRA, CERCLA, and
the National Environmental Policy Act (NEPA).
Section 117(A) of CERCLA, as amended, requires the
preparation of a proposed plan as part of the site
remedial process. The Proposed Plan for the M-Area
West Unit (PP) (WSRC, 1995), which is part of the
Administrative Record File, highlights key aspects of
the investigation and identifies the preferred action for
addressing of the M-Area West unit.
The Administrative Record File, which contains the
information pertaining to the selection of the response
action, was made available at the EPA-Region office
and at the following locations:
U.S. Department of Energy
Public Reading Room
Gregg-Graniteville Library
University of South Carolina-Aiken
171 University Parkway
Aiken, South Carolina 29801
(803) 641-3465
Thomas Cooper Library
Government Documents Department
University of South Carolina
Columbia, South Carolina 29208
(803) 777-4866
Similar information was made available through the
following repositories:
Reese Library
Augusta College
2500 Walton Way
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Record of Decision
M-Area West
WSRC-RP-95-626
Rev. 0, August 1995
Augusta, Georgia 30910
(404) 737-1744
Asa R Gordon Library
Savannah State College
Tompkins Road
Savannah, Georgia 31404
(912)356-2183
The public was notified of the comment period for the
PP through mailings of the S R S Environmental
Bulletin, a newsletter sent to more than 1400 citizens
in South Carolina and Georgia, and through notices in
local newspapers including the Aiken Standard, The
State, and the Augusta Chronicle.
The public comment period began on July 19,1995 and
ended on August 18, 1995. Comments received are
addressed in the Responsiveness Summary (Appendix
A).
IV. Scope and Role of Operable Unit within
the Site Strategy
The overall strategy for addressing the M-Area West
unit was to: (1) characterize the waste unit delineating
the nature and extent of contamination and identifying
the media of concern (perform the RFI/RI); (2)
perform a baseline risk assessment to evaluate media
of concern, chemicals of concern, exposure pathways
and characterize potential risks; and (3) evaluate and
perform a final action to remediate, as needed, the
identified media(s) of concern.
The investigation and risk assessment have been
completed for the M-Area West unit. Since the results
of the investigation indicate that M-Area West poses
no risk to human health or the environment, no action
was recommend.
The M-Area West unit is part of a larger integrator
Operable Unit (IOU) consisting of several surface
units and the A/M Area Groundwater unit. Since it
has been determined that the M-Area West unit does
not contribute contamination to the area groundwater
or surrounding soils, it has no impact to the larger IOU
and will not be addressed as part of the overall
strategy for the IOU. The proposed action for M-Area
West unit is a final action.
V. Summary of Operable Unit
Characteristics
There is no documented information available
regarding past hazardous or non-hazardous waste
disposal activities at M-Area West. Markings on the
drums found at the unit suggest that they once
contained oil and solvents, and that they are
approximately 37 years old. There is no evidence that
any recent disposal activity has occurred or that the
disposal activity was more widespread. Also, there is
no evidence of any burning or excavation at this waste
unit.
Preliminary Investigation /
Unit Screening
A preliminary soil gas survey was conducted in March
1988 and a unit screening consisting of four soil
borings was completed in November 1989. The unit
characterization which consisted of an extensive soil
gas survey was performed in July 1993. Confirmatory
soil sampling was performed in January 1994.
The preliminary soil gas survey, 1988, was conducted
to determine if hazardous substances had been
managed at the unit. Sample analyses showed
extremely low concentrations [< 4.2 ng/g] of trans-
1,2-dichloroethylene (a chlorinated solvent daughter
compound). This was the only constituent detected
suggesting that if solvent was disposed of at the unit or
had been present in the drums, the quantity was either
extremely low or that the concentrations measured
represent residual contamination remaining after years
of volatilization to the atmosphere. The presence of
low levels of volatile organic compounds in the soil gas
survey suggested the presence of some minimal
residual contamination for which additional
investigations were performed.
In 1989 a unit screening consisting of sample collection
from four borings was completed. Each soil boring
was drilled to an approximate depth of6.ini (20 feet)
below ground surface. Sampling intervals were
selected to (1) provide a sufficient screening to assess
whether a release had occurred and, if so, what
compounds are present, and (2) provide a sufficient
representation of the shallow
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Record of Decision
M-Area West
WSRC-RP-95-626
Rev. 0, August 1995
subsurface conditions at the site. One shallow soil
boring was located intermediate to and across the road
from the two areas of the unit to assess background
soil characteristics.
The samples were analyzed for volatile organic
compounds (VOCs), semi-volatile organic compounds,
radionuclide indicators, total metals, soil pH, TOC, and
CEC.
Trace levels of VOCs and semi-volatiles were
detected.
RFI/RI Characterization
In July 1993, an extensive soil gas survey for shallow
and deep soil gas analysis was performed. Ninety-six
locations were sampled.
The surveys investigated the presence and distribution
of the C1-C4 hydrocarbons, the C5-C10 gasoline
range normal paraffins, the C11-C18 diesel range
hydrocarbons, the aromatic hydrocarbons [benzene,
toluene, ethylbenzene, xylene (BTEX)], and selected
chlorinated hydrocarbons (such as vinyl chloride,
methylene chloride, trans-1,2 dichloroethylene,
chloroform, and carbon tetrachloride).
Levels of chlorinated hydrocarbons and diesel range
hydrocarbons (Cl 1-C18) were below detection levels.
Levels of light hydrocarbons were mostly below
detection with values above detection levels being
consistent with background sample levels across the
unit. Levels of octane (< 1.3 ppm) and o-xylene (< 5.5
ppm) were thought to be related to natural products
such as pine resin from the pine trees at the unit. A
low level anomaly of toluene (0.143 ppm), ethyl
benzene (0.113 ppm), and propane (1.4 ppm) was
found in a sample adjacent to the road. The source of
these compounds was not certain; however, it is
suspected that hydrocarbon fluid may have leaked
from the tractor involved in the soil gas survey or
brush cutting operations that was parked overnight at
the unit. A detailed summary of the soil gas survey
report is included in the Phase II RFI/RI Plan
(WSRC, 1993).
A Ground Penetrating Radar (GPR) survey was
conducted at the unit on July 21, 1993.
Soil sampling was performed on August 16, 1993 to
determine if any anomalies detected by the GPR were
buried materials. A summary of the geophysical data
and the GPR survey report are included in the Phase
II RFI/RI Plan (WSRC, 1993). Based on a review of
the GPR data, there are no obvious pits, trenches, or
areas of disturbed soil within the grid utilized.
A magnetometer survey was also conducted at
M-Area West in June of 1993. Standard magnetic
surveying techniques were followed. No additional
surface debris, buried debris, trenches or other objects
are evident from the data provided by the
magnetometer survey.
Based on the results of the unit screening activities and
combined with the detection of low level semivolatiles
in soil borings, additional soil sampling activities were
recommended to sufficiently characterize this unit.
A confirmatory soil assessment sampling plan was
designed for M-Area West to further assess the
horizontal extent and vertical migration of any
hazardous constituents at the unit. Additional purposes
of the soil assessment included the generation of
sufficient data for risk assessment, corrective
measures alternatives assessment, and remedial action,
if required. Locations for soil samples were based on
potential migration pathways and sampling results from
preliminary studies. Relevant background samples
were specified for comparison.
Surface water/sediment sampling was not conducted
because the nearest surface water body is
approximately 304.9 meters (1000 feet) away and
disposal activities at the unit were not extensive and
would not have an impact on surface water.
Groundwater sampling was not conducted because of
the low level of contaminants and the depth to
groundwater (approximately 39 m).
Seven soil borings were drilled at the unit during the
soil assessment phase. Three samples were collected
from each borehole; one surface sample and two
subsurface samples. Three boring were located within
the larger of the two debris grew and one was located
in the
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Record of Decision
M-Area West
WSRC-RP-95-626
Rev. 0, August 1995
smaller (northern) area. The remaining three soil
borings were located outside the unit to provide
background data.
All samples were analyzed in accordance with
EPA-approved protocols. The detailed analytical
results am contained in the Quality Control Summary
Report for the M-Area West Unit RFI/RI Unit
Assessment Report, (Appendix B of RFI/RI report
WSRC 1994). Validation and verification of the
analytical data were performed as part of the RFI/RI
data review process; therefore, the data were
considered acceptable for this evaluation.
Data from the 0.3-0.9 m (1.0-3.0 feet) interval were
used to evaluate surface soil for the risk assessment.
Data from the 1.2-1.8 m and 2.4-3.0 m (4.0-6.0 and
8.0-10.0 feet) depth intervals were evaluated to
determine if there is potential for contribution of
contamination to the groundwater.
The concentration level of the analytes, with the
exception of arsenic, at different intervals was very
low and insignificant in terms of having an effect on
human health and the environment. The concentration
level of arsenic at different depth intervals ranged
from 2.9 to 9.3 mg/kg with a mean value of 5.6 mg/kg
while the background concentrations ranged from 2.2
to 10 mg/kg with a mean value of 4.8 mg/kg. Arsenic
was only detected once in the 1.0 - 3.0 ft. interval. The
level detected was 2.1 mg/kg (which was a J value or
estimated value). No arsenic was detected in the 1.0
- 3.0 ft. background sample. Both the site specific
samples and the background arsenic concentrations
are of the same order of magnitude and are consistent
with SRS arsenic levels.
VI. Summary of Operable Unit Risks
Human Health Risks
As part of the RI/FS process for M-Area West, a risk
assessment was performed using the data generated
during the assessment phase. Detailed information
regarding the development of chemicals of potential
concern, the fate and transport of contaminants and
the risk assessment can be found in the RFI/RI
Report for M-Area, West (631 -21G), December 1994.
After assembling the analytical data and eliminating
those analytes not detected in any samples, the
chemicals of potential concern (COPCs) were
selected based on criteria specified in EPA risk
assessment guidance.
As a result of comparing the unit sample
concentrations background concentrations, four
constituents (arsenic, manganese, xylene, cyanide)
wore found to be above unit background and nine
were detected in the unit specific samples but were
not detected in the background samples. These
analytes were further screened in the process.
The remaining analytes were identified following the
methods and rationale described by EPA risk
assessment guidelines. Table 1 lists the potential
contaminants following the data screening.
The Risk-Based Concentrations (RBCs) were
developed using protective default exposure scenarios
suggested by EPA and the best available reference
doses and carcinogenic potency slopes, and represent
protective environmental concentrations at which EPA
would typically not take action. The table contains
levels of nearly 600 contaminants in air, drinking
water, fish tissue, and soil, which correspond to a
systemic hazard quotient of 1.0 or a lifetime cancer
risk of one in one million (1.0 x 10~06).
The EPA developed guidance is intended to identify
and to focus on dominant chemicals of potential
concern and exposure mutes at the earliest feasible
point in the baseline risk assessment. The use of these
methods, selecting exposure routes and contaminants
of concern by RBCs, assist in focusing the assessment
on the significant contaminants.
For the remaining analytes in Table 1, the risk-based
concentration screen was used to further reduce the
list. The RBC values as shown in Table 2 were taken
from the EPA Region III Risk-Based Concentration
table dated March 7, 1995. Sample concentrations
detected were compared to the RBCs and screened
out as COPCs if they were below the RBC levels.
As a result of comparing the constituents to the
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Record of Decision
M-Area West
WSRC-RP-95-626
Rev. 0, August 1995
risk-based concentration values, only arsenic exceeded
a risk of one in one million (1.0 X 10~06) but was less
than one in one hundred thousand (1.0 x 10'05) and
remained as a COPC. Arsenic was detected only once
in the site specific samples and was not detected in
any of the background samples in the 1.0-3.0 feet
interval.
Sources of contamination, releases, fate and transport
mechanisms, exposure points, and routes were
integrated in order to the complete exposure pathways
that exist at the unit. If any of these elements were
missing, the pathway was incomplete and not
considered in the baseline risk assessment (BRA) for
M-Area West.
Cancer risks are estimated as the incremental
probability of an individual developing cancer over a
lifetime as a result of pathway-specific exposure to
carcinogenic contaminants. The risk to an individual
resulting from exposure to non-radioactive chemical
carcinogens is expressed as the increased probability
of a cancer occurring over the course of a 70 year
lifetime. Cancer risks are related to the EPA target
range of 1 x 10~04 to 1.0 x 10~06 for incremental cancer
risk at NPL sites. Risk levels at or above 1 x 10'04 are
generally considered significant. In order to account
for simultaneous, exposure to multiple carcinogens
through a given pathway, the risks calculated for each
individual carcinogen in that medium were summed to
obtain an estimate of the total cancer risk for the
pathway.
Non-carcinogenic effects were evaluated by
comparing an exposure level over a specified time
period (e.g., lifetime) with a reference dose (RfD)
derived for a similar exposure period. To evaluate the
non-carcinogenic effects of exposure to soil
contaminants, the hazard quotient, HQ (the ratio of the
exposure dose to the RfD) is calculated for each
contaminant. The non-carcinogenic HQ assumes that
below a given level of exposure (i.e., the RfD), even
sensitive populations are unlikely to experience
adverse health effects. If the exposure level exceeds
this threshold (1.0) there may be concern for potential
noncarcinogenic health effects.
HQs are summed for each exposure pathway to
create a pathway specific hazard index (HI) for each
exposure scenario. T'he more the Hazard Index
exceeds unity, the greater the concern that adverse
health effects will occur. The hazard quotient is not a
percentage or probability.
The maximum concentration value was used as the
exposure point concentration.
Current Land Use
Under the current land use scenario, there was no
determination of carcinogenic risks and
noncarcinogenic hazards because no worker activity
occurs in the area
Future Land Use
Under the future land use scenario, carcinogenic risks
and non-carcinogenic hazards associated with
non-radioactive COCs were calculated for exposure of
the future on-unit resident (adult and child) to surface
soils and air.
Total cancer risk at M-Area West is 9.8 x lO'06.
Table 3 shows the individual results for the future
resident scenario.
Non-carcinogenic Hazard
His for the soil pathways were calculated for
adulthood and childhood exposures combined and for
childhood exposure only. All of the exposure pathways
for the on-unit resident have His less than one.
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Record of Decision
M-Area West
WSRC-RP-95-626
Rev. 0, August 1995
Table 1. Analytes Remaining After Comparison to Background - 1.0 - 3.0 Feet Only.
Analyte
Arsenic
Manganese
Chloromethane
Ethylbenzene
Xylene
Cyanide
Benzoic acid
2-Hexanone
Acetone
Carbon Bisulfide
2-Chlorophenol
Dichloromethane
Toluene
Sample Number
Unit
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
05-01
U
J42
U
J 0.072
J0.69
J170
U
U
U
J0.47
J5.7
J0.43
JO. 14
06-01
U
J180
J 0.071
U
U
J190
640
J0.25
U
U
U
J0.49
U
07-01
ND
ND
U
U
U
ND
U
U
U
ND
U
JO. 68
U
08-01
J2.1
J2.6
U
U
JO. 14
J 2,500
U
U
J8.9
U
U
U
U
09-01 A
ND
ND
U
U
U
ND
U
U
J3.9
JO. 15
U
J0.72
U
U-The result qualifier is assigned to analytical results below the sample quantification limit
J-The result is an estimated value.
ND-No Data/Not Applicable
Table 2. Estimated Risk-Based Concentrations - Hypothetical Future Resident Adult and Child
Contaminant
Arsenic(mg/kg)
Manganese(mg/kg)
Chloromethane(mg/kg)
Ethylbenzene(mg/kg)
Xylene(mg/kg)
Cyanide(mg/kg)
Benzoic acid(mg/kg)
2-Hexanone(mg/kg)
Acetone(mg/kg)
Carbon Disulfide(mg/kg)
2-Chlorophenol(mg/kg)
Dichloromethane(mg/kg)
Toluene(mg/kg)
Carcinogenic Risk Hazard Index
1.0 x 10 °6
0.37
ND
49,000
ND
ND
ND
ND
ND
ND
ND
ND
85,000
ND
1.0 x 10 °5
3.7
ND
490,000
ND
ND
ND
ND
ND
ND
ND
ND
850,000
ND
1.0 x 10 °4
37
ND
4,900,000
ND
ND
ND
ND
ND
ND
ND
ND
8,500,000
ND
0.1
ND
1095
ND
780,000
16,000,000
160,000
31,000,000
ND
780,000
780,000
39,000
ND
1,600,000
1.0
ND
10.950
ND
7,800,000
160,000,000
1,600,000
310,000,000
ND
7,800,000
7,800,000
390,000
ND
16,000,000
ND - No Data/Not Applicable
Table 3. Summary of risk assessment results for arsenic.
Pathway
Dermal Contact
Ingestion
Inhalation
Total
Carcinogenic Risk
Adult/Child
2.5 x 10-08
5.8x 10-06
4. Ox 10-06
9.8 xlO-06
Child Only
7.0 xlO-09
4.0 xlO-06
2.6 xlO-06
6.6 xlO-06
Non-Carcinogenic (Hazard)
Adult/Child
2.7 xlO-04
1.0 xlO-01
.36
5.0 xlO-01
Child Only
1.7xlO-°4
9.0 x 10-02
0.02
l.OxlO-01
10
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Record of Decision
M-Area West
WSRC-RP-95-626
Rev. 0, August 1995
Ecological Risks
The ecological information base for M-Area West
consists of a unit-specific threatened, endangered and
sensitive species survey and a unit-specific ecological
reconnaissance. Review of this information can be
summarized as follows:
• The unit occurs within a 40 year old loblolly pine
plantation and there is no obvious evidence of vegetation
stress or ecological impact related to the unit;
• There are no threatened or endangered species
known to exist at or in the vicinity of the unit;
• Review of the unit characterization data
indicates that there are no constituents in the physical
media analyzed at M-Area West which are significantly
different from the unit specific background condition.
Based on the physical and analytical data obtained for
this unit, there is no compelling evidence that waste
materials were managed or disposed at the M-Area
West operable unit. Therefore, it is reasonable to
conclude that the unit as it is currently characterized,
presents no ecological risk.
VII. Description of the No Action
Alternative
According to the EPA guidance document Guidance on
Preparing Superfund Decision Documents, (EPA,
1989) if there is no current or potential threat to human
health and the environment and no action is warranted,
the CERCLA 121 requirements are not triggered. This
means that there is no need to evaluate other alternatives
or the no action alternative against the nine criteria
specified under CERCLA.
Under the No Action alternative, no treatment will be
performed because there is no waste to treat. No new
institutional controls or engineering controls will be
implemented and there is no cost associated with
implementing the alternative. According to CERCLA
regulations, Section 121, if no action is the preferred
action, then no ARARs apply to the waste unit.
Since M-Area poses no risk and the no action alternative
is warranted, it does satisfy the CERCLA criteria. The
no action alternative is intended to be the final action for
M-Area West. This solution is meant to be permanent
and effective in both the long and short term. The no
further action decision is the least cost option with no
capital, operating, or monitoring cost and is protective of
human health and the environment.
Vin. Explanation of Significant
Changes
No significant changes were made ot the Record of
Decision based on the public comment period for the
proposed plan. Only one public comment was received
and had no impact on the no action preferred alternative.
11
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Record of Decision WSRC-RP-95-626
M-AreaWest Rev. 0, August 1995
IX. References
DOE (U.S. Department of Energy), 1994. Public
Involvement, A Plan for the Savannah River
Site. Savannah River Operations Office, Aiken,
South Carolina.
EPA (U.S. Environmental Protection Agency), 1989.
Guidance on Preparing Superfund Decision
Documents. Office of Solid Waste and
Emergency Response - OSWER Directive
9355.3-02.
EPA (U.S. Environmental Protection Agency), 1991
Guide to Developing Superfund No Action,
Interim Action and Contingency Remedy RODs
Office of Solid Waste and Emergency Response
- 9355.3-02FS-3.
FFA, 1993. Federal Facility Agreement for the
Savannah River Site, Administrative Docket
Number 89-05-FF (effective date: August 16,
1993).
WSRC (Westinghouse Savannah River Company),
Phase IIRFI/RI Plan for M-Area West Unit,
WSRC-RP-90-995, Rev. 2, Westinghouse
Savannah River Company, Aiken, SC. (1993).
WSRC (Westinghouse Savannah River Company),
RFI/RIReport for M-Area West Unit (631-21G)
(U), WSRC-RP-94946, Rev. 1, Westinghouse
Savannah River Company, Aiken, SC. (1995;
includes baseline risk assessment).
WSRC (Westinghouse Savannah River Company).
Proposed Plan for the M-Area West Unit
(631-21G) (U), WSRC-RP-95469, Rev. 1,
Westinghouse Savannah River Company, Aiken,
SC.
12
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