PB99-964011
EPA541-R99-053
1999
EPA Superfund
Record of Decision:
Savannah River Site (USDOE)
Ford Building Waste Unit (643-llG) OU 57
Aiken, SC
5/20/1999
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United States Department of Energy
Savannah River Site
Record of Decision
for the
Ford Building Waste Unit (643-11G)
Operable Unit (U)
WSRC-RP-98-4066
Revision 1
April 1999
Westinghouse Savannah River Company
Savannah River Site A* %
Aiken, SC 29808 * C* 5"B IT \
W "^^» S^K *^^ **•
Prepared for the U. S. Department of Energy under Contract No. DE-AC09-96-SR18500 SAVANNAH «IVER SITE
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Printed in the United States of America
Prepared for
U. S. Department of Energy
and
Westinghouse Savannah River Company
Aiken, South Carolina
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RECORD OF DECISION
FOR THE FORD BUILDING WASTE UNIT (643-11G)
OPERABLE UNIT (U)
WSRC-RP-98-4066
Revision 1
April 1999
Savannah River Site
Aiken, South Carolina
Prepared by:
Westinghouse Savannah River Company
For the
U. S. Department of Energy Under Contract DE-AC09-96SR18500
Savannah River Operations Office
Aiken, South Carolina
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Department of Energy
Savannah River Operations Office
P.O. Box A
Aiken, South Carolina 29802
SEP I 4 !999
Mr. K. A. Collinsworth, Manager
Federal Facility Agreement Section
Division of Site Assessment and Remediation
Bureau of Land and Waste Management
South Carolina Department of Health and Environmental Control
2600 Bull Street
Columbia, SC 29201
Mr. J. L. Crane
SRS Remedial Project Manager
Waste Management Division
United States Environmental Protection Agency, Region IV
61 Forsyth Street, SW
Atlanta, GA 30303
Dear Mr. Collinsworth and Mr. Crane:
SUBJECT: Submittal of the Signed Copy of the Record of Decision for the Ford Building
Waste Unit (643-11G) Operable Unit (WSRC-RP-98-4066, Revision. 1, Final)
Please find enclosed the signed copy of the Record of Decision (ROD) for the Ford Building
Waste Unit Operable Unit for your records.
Questions from you or your staff may be directe at (803) 725-7032,
jfncenely,
I/-
sri^n T. Hennessey
Remedial Project Manager
(vironmental Restoration Division
BTH/JLK:lp
OD-99-337
Enclosure
1 Record of Decision for the Ford Building Waste Unit (643-11G) Operable Unit
WSRC-RP-9*."ii>f\ Revision. 1. Fin;-!'
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c:
A B. Gould. US DOE-ECD, 703-A
C. V. Anderson. US DOE-ERD. 703-A
C. B. Warren, US EPA-IV
J. L. Corkran. US EPA-I\'
S. A. Holt. Dynamac
J. K. Cresswell, SCDHEC-Columbia
J. T. Litton. SCDHEC-Columbia
G. K. Taylor, SCDHEC-Columbia
M. D. Sherritt, SCDHEC-Columbia
Administrative Record File, 730-2B, Room 1000*
*w/enclosure
SEP
'
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Record of Decision for the \VSRC-RP-98-4066
Ford Building Waste I nit (643-11G) Operable Unit (U) R"ision '
Savannah River Site. April 1999 Declaration I
DECLARATION
Site Name and Location
Ford Building Waste Unit (643-11G)
Savannah River Site
Aiken, South Carolina
The Ford Building Waste Unit (643-11C) (FBWU) Operable Unit 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 (SRS).
Statement of Basis and Purpose
This decision document presents the selected remedial for the FBWU, in Aiken, South
Carolina, which was chosen in accordance with CERCLA, as amended by SARA, and, to the
extent practical, the National Oil and Hazardous Substances Pollution Contingency Plan
(NCP). This decision is based on the Administrative Record File for this specific
RCRA/CERCLA site.
The state of South Carolina concurs with the selected remedy.
Description of the Selected Remedy
The selected remedy for FBWU is "No Further Action". The Baseline Risk Assessment
(BRA) considered current, future industrial and future residential land use scenarios. Based
on these scenarios, the BRA concluded that there were no final constituents of concern
(COCs) (i.e., no contaminant migration constituents of concern [CM COCs], human health
COCs, or ecological COCs). Therefore, no further action is required to clean up the FBWU
to acceptable levels.
Declaration Statement
A time-critical removal action was implemented in early 1997. This removal action focused
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Record of Decision for the « SRC-RP-98-4066
Ford Building \Saste Unit (643-1IG) Operable Unit (U) Revision I
Savannah River Site. April 1999 Declaration 2
on removing secondary sources consisting of surface and subsurface soils that contained
levels of cesium-137 above the time-critical action cleanup goal of 0.35 pCi/g. The cleanup
goal was set to the unit-specific two times (2X) average background.
Based on the FBWU RCRA Facility Investigation/Remedial Investigation (RFI/RI) Report
and the BRA, no further action is necessary at the FBWU to ensure the protection of human
health and the environment. Since the FBWU poses no risk to human health and the
environment, and no further action is needed, the CERCLA Section 121 requirements are not
applicable. 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 meant to be a permanent solution, and final action,
for the FBWU operable unit.
Section 300.430(f)(ii) of the National Oil and Hazardous Substances Pollution Contingency
Plan requires that a Five-Year Review of the Record of Decision (ROD) be performed if
hazardous substances, pollutants, or contaminants remain at the unit. The US EPA,
SCDHEC, and US DOE have determined that a Five-Year Review of the ROD for the
FBWU operable unit will not be performed. The remedial action for this unit ("No Further
Action") results in no hazardous substances, pollutants, or contaminants remaining in the
soils of the FBWU operable unit.
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Record of Decision for the WSRC-RP-98-4066
Ford Building Waste Unit (643-11C) Operable Unit (U) Revision I
Savannah River Site, April 1999 Declaration 3
Date Thomas F. Heenan
Assistant Manager for Environmental Programs
U. S. Department of Energy, Savannah River Operations Office
Date Richard D. Green
Division Director
Waste Management Division
U. S. Environmental Protection Agency - Region IV
Date R. Lewis Shaw
Deputy Commissioner
Environmental Quality Control
South Carolina Department of Health and Environmental Control
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WSRC-RP-98-4066
Record of Decision for the Revision I
Ford Building Waste Unit (643-11G) Operable Unit (U) Declaration 4
Savannah River Site, April 1999 ^^^
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Record of Decision for the \\SRC-RP-98-4066
Ford Building Waste Unit (643-11G) Operable l.'nit (U) Revision I
Savannah River Site, April 1999 Page i of vi
DECISION SUMMARY
FOR THE FORD BUILDING WASTE UNIT (643-11G)
OPERABLE UNIT (U)
WSRC-RP-98-4066
Revision 1
April 1999
Savannah River Site
Aiken, South Carolina
Prepared by:
Westinghouse Savannah River Company
For the
U. S. Department of Energy under Contract DE-AC09-96SR18500
Savannah River Operations Office
Aiken, South Carolina
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Record of Decision for the
Ford Building \\ astc I nit (643-1 IG) Operable Unit (L;)
Savannah River Site. April 1999
Reusion I
Page ii of vi
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Record of Decision for the \VSRC-RP-98-»066-
Ford Building Waste I nit (643-11C) Operable Unit (I?) Re\ision I
Savannah River Site. April 1999 ^ Pagciiiofvi
TABLE OF CONTENTS
Section E*2£
DECLARATION !
I. Site Name, Location, and Description 1
II. Site History and Enforcement Activities 6
III. Highlights of Community Participation 9
IV. Scope and Role of Operable Unit Within the Site Strategy 11
V. Site Characteristics 12
VI. Summary of Site Risks • 17
VII. Conclusions 30
VIII. Explanation of Significant Changes 32
IX. Responsiveness Summary 32
X. REFERENCES 33
LIST OF FIGURES
Figure 1. Location of FBWU at the SRS 2
Figure 2. Oblique Aerial Photograph of the FBWU Area (April 1996) 3
Figure 3. Location of FBWU in the Fourmile Branch Watershed 4
Figure 4. Central Shops Enlarged Figure 3-3 from the FIP 5
Figure 5. Excavation Map with Pre-Removal Sodium-Iodide Detector Survey Results 7
Figure 6. Location of Background Soil Borings 13
Figure 7. FBWU Sampling Locations •'••• 14
Figures. Conceptual Site Model for the FBWU 15
Figure 9. Summary of Chemical Risks and Hazards Across Pathways 19
Figure 10. Summary of Radiological Risks Across Pathways 20
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Record of Decision for the « SRC-RP-WMOw.
Ford Building \\astc Unit (643-UG) Operable Unit (L) Revision I
Savannah River Site, April 1999 Page is o(M
LIST OF TABLES
Table 1. Risk Characterization Summary: Current Land Use Scenario - Surface Soil 22
Table 2. Risk Characterization Summary: Future Land Use Scenarios - Surface Soil 23
Table 3. Risk Characterization Summary: Future Land Use Scenarios - Subsurface Soil ....24
4ft
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Record of Decision for the
Ford Building Waste Unit (643-11G) Operable Unit (U)
Savannah River Site, April 1999
Revision 1
Page v of M
ACRONYMS
2X two times
ARARs Applicable, or Relevant and Appropriate Requirements
bis below land surface
BRA Baseline Risk Assessment
CERCLA Comprehensive Environmental Response, Compensation and Luibilin Act
CM COCs Contaminant Migration Constituents of Concern
COCs Constituents of Concern
COPCs Constituents of Potential Concern
ELCR Excess Lifetime Cancer Risk
FBWU Ford Building Waste Unit (643-11G)
FFA Federal Facility Agreement
FD? FFA Implementation Plan
ft. feet
HI Hazard Index
HQ Hazard Quotient
km Kilometer
m Meter
mi. Mile
pCi/g Picocurie/gram
RAOs Remedial Action Objectives
RBC Risk Based Concentration
RCRA Resource Conservation and Recovery Act
RFI RCRA Facility Investigation
RGOs Remedial Goal Options
RI Remedial Investigation
ROD Record of Decision
SCA Soil Contamination Area
SCDHEC South Carolina Department of Health and Environmental Control
SCHWMR South Carolina Hazardous Waste Management Regulations
sq. Square
SRS Savannah River Site
TCHI Total Cumulative Hazard Index
TCL ~ Target Compound List
TCR Total Cumulative Risk
TICs Tentatively Identified Compounds
TMR Total Medium Risk
URMA Underground Radioactive Materials Area
USCs Unit-Specific Constituents
US DOE U.S. Department of Energy
US EPA U.S. Environmental Protection Agency
WSRC Westinghouse Savannah River Company
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Record of Decision for the \\SRC-RP-9R-406t,
Ford Building Waste Unit (643-11C) Operable L'nit (L1) Revision I
Savannah River Site. Aprill 999 Pagcxiofvi
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Record of Decision for the \VSkC'-R!'-')8-4()(i(i
Ford Building Waste Unit (M3-11G) Operable Unit (U) KCMMDII I
Savannah River Site. April 1999 I'ayt.- I irl .U
I. SITE NAME, LOCATION, AND DESCRIPTION
Savannah River Site (SRS) occupies approximately 800 sq. km (310 sq. mi.) of land adjacent
to the Savannah River, principally in Aiken and Barnwell counties of South Carolina. SRS is
a secured U.S. Government facility with no permanent residents. SRS i.-> located
approximately 40 km. (25 mi.) southeast of Augusta. Georgia, and 32 kilometers (20 mile.^i
south of Aiken, South Carolina.
SRS is owned by the U.S. Department of Energy (US DOE). Management and operating
services are provided by Westinghouse Savannah River Company (WSRC). SRS ha:,
historically produced tritium, plutonium, and other special nuclear materials for national
defense.
The Ford Building Waste Unit (643-1IG) (FBWU) is located near the center of the SRS
(Figure 1). A photograph of the unit is provided as Figure 2. The FBWU now consists of a
rectangular area measuring 9.1 to 10.4 m (30 to 34 ft) wide by 53.0 m (174 ft) long. Prior to
a time-critical removal action in 1997, approximately one-half of the FBWU was marked
with yellow chains and signs delineating an Underground Radioactive Materials Area
(URMA). Additionally, the FBWU contained a Soil Contamination Area (SCA) of
approximately 1 x 1 m (3 x 3 ft).
The FBWU is a source control and groundwater operable unit in the Fourmile Branch
watershed (Figure 3). The Federal Facility Agreement (FFA) lists FBWU as a Resource
Conservation and Recovery Act (RCRA)/Comprehensive Environmental Response,
Compensation and Liability Act (CERCLA) unit, requiring evaluation using an
investigation/assessment process that integrates and combines the RCRA Facility
Investigation (RFI) process with the CERCLA Remedial Investigation (RI) to determine the
actual or potential impact to human health and the environment.
The FBWU is located in the industrial buffer zone of N Area (Central Shops) and will remain
industrial use in the future, in accordance with SRS Citizens Advisorv Board
Recommendation #2. The unit is not located within an area expected for future Heavy
Industrial (Nuclear Use) activity. Figure 4 (i.e., Figure 3-3 of FIP) is an enlarged section of
the CAB Recommendation #2 map.
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Record oT Decision for the
Ford Building \Vastc Unit (643-11C) Operable Unit (U)
Savannah River Site. April 1999
« SRC-RP-98-1066
Rc\ision I
SRS
North
N Area
CArea ^(Central Shops)
True
North
\
FBWU
miles
I—hH—I—I
01234
GEORGIA
SOUTH
CAROLINA
Figure 1. Location of FBWU at the SRS
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Record of Decision for the
Ford Building Waste Unit (643-11G) Operable Unit (L1)
Savannah River Site, April 1999
WSRC-RP-98-4066
Revision 1
Page 3 of 34
Ford Btoilding
ri^Appivxu
/#•• :.^
.-!•• -•. •fX'&X
" "\-'v •¥":
Kchanger Pad'
'"' Lavdbwn Area
Figure 2. Oblique Aerial Photograph of the FBWU Area (April 1996)
Photograph was taken prior to the 1997 time-critical removal action; the unit is currently
grass-covered with two mature pine trees remaining near the northwest corner of the unit
(lower left side of the unit on the photograph).
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Record ol'Decision tor the
Ford Building \\astc Lnit (6-13-11C) Operable Unit (U)
Savannah River Site, \pril 1999
VVSRC-RP-98--J066
Revision 1
Page 4 of .'-4
OXKI
"A,
O
K
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Record of Decision for the
Ford Building Waste Unit (6-43-11C) Operable Unit (U)
Savannah River Site, April 1999
\VSRC-RP-98-4066
Revision 1
Pai?e 5 of 34
fill
S I I I
LEGEND
HEAVY INDU
INUCLE4R,
•NON-NUCLEW •
1 i
1 :.,RftEN'
NO
Figure 4. Central Shops Enlarged Figure 3-3 from the FIP
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Record oTDecision for the VV.SRC-RP-98-1066
Ford Building \\aste Unit (6-43-11C) Operable Unit (U) Rc\ision I
Savannah River Site, April 1999 Page 6 of 34
II. SITE HISTORY AND ENFORCEMENT ACTIVITIES
Operable Unit History
Operations with regulated radioactive equipment probably occurred at the FBWU
(\VSRC, 1998a). The nearby Ford Building was used for the reconfiguration and repair of
reactor heat exchangers and other process equipment that had been decontaminated prior to
receipt at the facility. There are no records of waste disposal for the FBWU. However, in the
past, objects identified on the surface of the waste unit included shoe covers, step-off pads.
coveralls, and rubber gloves. These are typical wastes from work performed in radiological
controlled areas. In addition, a sign typically used to designate a radiologically controlled area
marked the site. This sign, personal protective clothing, and contamination control equipment
indicate that regulated work was performed at this location. All surface debris was removed
from the unit in an undocumented removal sometime prior to 1992.
Cesium-137 was produced at SRS in tremendous quantities and is a ubiquitous SRS
contaminant with a relatively long half-life (about 30 years). It is reasonable to conclude that
the radiological work performed at this location resulted in releases of cesium-137 to the soil.
Low levels of radioactivity were detected at the FBWU in 1988 while grounds maintenance
work was being performed. A subsequent radiation survey, conducted in 1990, also detected
low levels of radioactivity (1 millirem per hour). As a result of these findings, the area was
posted as a Soil Contamination Area (SCA) to protect site workers from inadvertent
exposure. Additionally, a larger area was designated as an Underground Radioactive
Materials Area (URMA) to indicate the possibility of buried material. However, subsequent
Ground Penetrating Radar survey results, soil sampling results and a time-critical removal
action demonstrated that there was no buried waste at the unit.
Based on pre-Work Plan analytical data, cesium-137 was detected at elevated levels in the
surface and subsurface soils (Figure 5). A time-critical removal action was implemented in
early 1997 to address these secondary sources of contamination. The time-critical removal
action focused on removing secondary sources consisting of surface and subsurface soils that
contained levels of cesium-137 above the time-critical removal action cleanup goal of 0.35
pCi/g. The cleanup goal was set to the unit-specific two times (2X) average background.
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Record of Decision for the
Ford Building Waste Unit (643-11C) Operable Unit (U)
Savannah River Site, April 1999
\\SRC-RP-98-4066
Revision I
Page 1 of 34
-
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I
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Record or Decision for the VVSRC-RP-98-4066
Ford Building Waste Unit (6-43-11G) Operable Unit (L1) Revision I
Savannah River Site, April 1999 Page 8 of 34
concentration using established protocols at the time. The goal of the time-critical removal
action was to remove contaminated soil so that the concentrations and risks associated with
cesium-137 in the remaining unit soils would be indistinguishable from those of background.
The time-critical removal action was guided by analytical results of soil samples collected
during the removal action and field surveys with a sodium-iodide detector calibrated for
cesium-137. The following areas, depicted in Figure 5, were removed:
• The SCA and the area around boring FBWU-01 were excavated to a depth of
approximately 1.5 m (5 ft) (Area A)
• The URMA was excavated to a depth of approximately 0.3 m (1 ft) (Area B)
• An area measuring approximately 3x6m(lOx20ft) west of the URMA around
the site of soil boring FBWU-04 was excavated to a depth of approximately
0.l5m(0.5ft)(AreaC)
• An area of soil at the south perimeter of the URMA measuring 7.5 x 27 m
(25 x 90 ft) was excavated to a depth of 0.15 to 0.3 m (0.5 to 1 ft) (Area D)
• An area of soil south of the URMA measuring 2.4x3.Om (8 x 10ft) was
excavated to a depth of 0.15 to 0.3 m (0.5 to 1 ft) (Area E)
A total of 96.3 m3 (126 yd3) of soil was removed. The waste was placed in skid pans and
dispositioned to engineered trenches at the SRS Low Level Radioactive Waste Disposal
Facility in E Area. The SRS radiological control organization removed the SCA postings and
associated barricades after the time-critical removal action.
SRS Compliance History
Waste materials handled at SRS are regulated and managed under RCRA, a comprehensive
law requiring responsible management of hazardous waste. Certain SRS activities have
required federal operating or post-closure permits under RCRA. SRS received a hazardous
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Record of Decision for «hc * SRC-RP-98-4HM.
Ford Building \Sastetnit (643-1IG) Operable Unit (I') Rcwsion I
Savannah River Site, April 1999 t_ Page 9 of 34
waste permit from the South Carolina Department of Health and Environmental Control
(SCDHEC); the permit was most recently renewed on September 5. 1995. Part V of the
permit mandates that SRS establish and implement an RFI program to fulfill the
requirements specified in Section 3004(u) of the federal permit.
On December 21, 1989, SRS was included on the National Priorities List. The inclusion
created a need to integrate the established RFI program with CERCLA requirements to
provide for a focused environmental program. In accordance with Section 120 of CERCLA.
US DOE has negotiated an FFA (FFA, 1993) with U.S. Environmental Protection Agency
(US EPA) and SCDHEC to coordinate remedial activities at SRS into one comprehensive
strategy to fulfill these dual regulatory requirements.
Operable Unit Compliance History
As previously stated, the FBWU is listed in the FFA as a RCRA/CERCLA unit requiring
further evaluation to determine the actual or potential impact to human health and the
environment. Because pre-Work Plan data indicated the need for a time-critical removal
action, an RFI/RI Work Plan was not submitted and a Field Start date was omitted. A
Removal Site Evaluation Report (WSRC, 1997) was submitted in September 1996, and the
time-critical removal action was performed from January 8 to June 2, 1997. Results of the
time-critical removal action were presented in the RFI/RI with Baseline Risk Assessment
(BRA) (WSRC, 1998a). The RFI/RI/BRA was submitted in accordance with the FFA and
the approved implementation schedule, and was approved by US EPA and SCDHEC in June
1998. By agreement between US EPA, SCDHEC, and US DOE, a "No Further Action"
Statement of Basis/Proposed Plan was developed without the need for a Corrective Measures
Study/Feasibility Study. The Statement of Basis/Proposed Plan was submitted in accordance
with the FFA and the approved implementation schedule and was approved by the US EPA
and SCDHEC in October 1998.
III. HIGHLIGHTS OF COMMUNITY PARTICIPATION
Both RCRA and CERCLA require that the public be given an opportunity to review and
comment on the draft permit modification and proposed remedial remedy. Public
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Record of Decision for «he « SRC-RP-OS-4066
Ford BuiltlinR \\ aste t nit (64J-1 1C) Operable Unit (U) Rc' ISIOM '
SaNannah River Site. April 1W» _ ; _ Pa,jc_IO_oO4
participation requirements are listed in South Carolina Hazardous Waste Management
Regulation (SCHWMR) R.61-79.124 and Sections 113 and 117 of CERCLA. These
requirements include establishment of an Administrative Record File that documents the
investigation and selection of the remedial remedy for addressing the FBWU soils and
groundwater. The Administrative Record File must be established at or near the facility at
issue. The SRS Public Involvement Plan (US DOE, 1994) is designed to facilitate public
involvement in the decision-making process for permitting, closure, and the selection of a
remedial solution. The SRS Public Involvement Plan addresses the requirements of RCRA.
CERCLA, and the National Environmental Policy Act. SCHWMR R.61-79.124 and Section
1 17(a) of CERCLA, as amended, require the advertisement of the draft permit modification
and notice of any proposed remedial action and provide the public an opportunity to
participate in the selection of the remedial action. The Statement of Basis/Proposed Plan for
the Ford Building Waste Unit (643- 1 1 G) (WSRC, 1998b), which is part of the
Administrative Record File, highlights key aspects of the investigation and identifies the
preferred action for addressing the FBWU.
The FFA Administrative Record File, which contains the information pertaining to the
selection of the response action, is available at the US EPA office and at the following
locations:
U. S. Department of Energy Asa H. Gordon Library
Public Reading Room Savannah State University
Gregg-Graniteville Library Tompkins Road
University of South Carolina- Aiken Savannah, Georgia 3 1 404
1 7 1 University Parkway (912) 356-2 1 83
Aiken, South Carolina 29801
(803)641-3465
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Record of Decision for the \\SRC-RP-98-4066
Ford Building \Vaste I nit (64.V11C) Operable Unit (L) Revision I
Savannah River Site. April 1999 Page 11 of 34
Thomas Cooper Library Reese Library
Government Documents Department Augusta State University
University of South Carolina 2500 Walton Way
Columbia, South Carolina 29208 Augusta, Georgia 30910
(803)777-4866 (706)737-1744
The public was notified of the public comment period through the SRS Environmental
Bulletin, a newsletter sent to approximately 3,500 citizens in South Carolina and Georgia.
through notices in the Aiken Standard, the Allendale Citizen Leader, the Augusta Chronicle,
the Barnwell People-Sentinel, and The State newspapers. The public comment period was
also announced on local radio stations.
The 45-day public comment period for the Statement of Basis/Proposed Plan and the draft
RCRA permit modification began on November 15, 1998, and ended on January 1, 1999. No
comments were received during the public comment period.
IV. SCOPE AND ROLE OF OPERABLE UNIT WITHIN THE
SITE STRATEGY
The overall strategy for addressing the FBWU was to (1) characterize the waste unit by
delineating the nature and extent of contamination and identifying the media of concern
(perform the RFI/RI); (2) perform a time-critical removal action; (3) perform a BRA to
evaluate media of concern, constituents of concern (COCs), exposure pathways, and
characterize potential risks; and (4) evaluate and perform a final action to remediate, as
needed, the identified media of concern.
The FBWU is a source control and groundwater operable unit in the Fourmile Branch
watershed. There are no ditches, drainage areas, or surface waters associated with the unit.
An unnamed tributary of Fourmile Branch is located approximately 396 m (1,300 ft) to the
north-northeast of the FBWU.
The SRS has recently concluded a surface and subsurface soil investigation at the FBWU.
The unit was initially evaluated with another waste site, but based upon preliminary
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Record of Decision for the \VSRC-RP-9X-4066
Ford Building \\aste I nil (643-11C) Operable Unit (O Revision 1
Sa\annah River Site. April 1999 pa(,c |T Of 34
characterization results. SCDHEC and US EPA concurred with US DOE's proposal to
separate the operable unit into two operable units (i.e., the FBWU and the Fire Department
Hose Training Facility). SCDHEC and US EPA also agreed that the investigation at the
FBWU adequately characterized contamination within that unit and along potential migration
pathways. This Record of Decision (ROD) will propose a final remedial action for the
FBWU operable unit.
V. SITE CHARACTERISTICS
Media Assessment
The soil sampling activities conducted at the FBWU and background locations (Figures 6 and
7) provided data on the types and extent of constituents present. These data were
supplemented by soil gas surveys conducted in 1986 and 1992 and field surveys with a
sodium-iodide detector conducted in 1997. The primary source of contamination at the
FBWU was miscellaneous radiological materials (removed prior to 1992). Secondary
sources of contamination were surface and subsurface soils (removed by the time-critical
removal action in 1997).
A conceptual site model was prepared which shows the potential human health and
ecological receptors and exposure pathways to assist in determining what samples were
needed during characterization. This conceptual site model is shown in Figure 8.
Pre-Work Plan sampling in 1996 consisted of five borings in the FBWU (FBWU-01 through
-05) (Figure 7) and five background borings (FBFDBG-01 through -05) (Figure 6). Five
depth intervals were sampled in each of these borings (0 to 0.3, 0.3 to 1.2, 1.2 to 2.1,
2.1 to 3.1, and 3.1 to either 4.0 or 4.3m [Oto 1, 1 to 4, 4 to 7, 7 to 10, and 10 to either
13 or 14 ft] below land surface [bis]). Each sample was analyzed for a comprehensive suite
of constituents including Target Analyte List inorganics with cyanide, Target Compound List
(TCL) volatile organic compounds with tentatively identified compounds (TICs), TCL
semivolatile organic compounds with TICs, pesticides, polychlorinated biphenyls, and
radionuclides. Gamma speciation was performed on all pre-Work Plan samples; alpha and
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Record of Decision for the
Ford Building \\asle I'nit (643-11C) Operable Unit (I')
Sa\:innah River Site. April 1999
\\ SRC-RP-9X-»(i(>o
Revi^iun I
Pan- I
N 6043QVd~
LEGEND
A BACKGROUND SOIL BORINGS
•4". .CONE PENETROMETER BORINGS
,-- ^..CONTOUR (10' INTERVAL)
^ -x.. . .CONTOUR <2' INTERVAL)
75 150
SCALE IN FEET
300
^ttsnajrr
/SRS
SAVANNAH RIVER SITE
\
CPT
AND BACKGROUND
SAMPLE LOCATIONS
turn tit im. U./UTEI
5. OMJT C / H-»-n
Figure 6. Location of Background Soil Borings
-------
Record ol Decision fur the tt >RC-RP-9S-40hh
ford Building \\aste L nit (6-43-1 1C) Operable L'nit (L) Revision 1
Sa\annah Rhcr Site. April 1999 Pa«c 14 of .'-4
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PRIMARY SECONDARY
PRIMARY RELEASE SECONDARY RELEASE
SOURCE MECHANISM SOURCE MECHANISM PATHWAY
Ford Building
Waste Unit
Mi*,. r, - - Surface
Misc. Deposition „ »
Radiological Soil
(Removed) 1
eg eg
.2 B .9 -s
51 II
1 " S 3
— &• UJ (O
EXPOSURE
ROUTE
KNOWN
On-Unit
Worker
HYPOTHETICAL
Industrial
Worker
On-Unil
Resident
KC()L(«;iCAL
Terrestrial
Aquatic
••" Volatilization "^ ^jr
l)usl Generation
Direct Contact
^ Inhalation
•
•
•
O
Biolic Bioia
*->• Uptake "*•
Infiltration/ „ . , ~ ..
(Operable 1. nit (I1)
Notes:
(1) Subsurface soil pathways are not evaluated for Ihe known on unit worker.
(2) Includes inhalation and dermal contact.
(}) l-nlbwing the \W1 lime-critical removal action, approximately 50% of the unit was covered with (U in (I ft) of clean backfill.
(4) As confirmed by the fate and iransport assessment, the FUWU is not a source of groulidwatcr contaminalion.
If.
71
O
Figure 8. Conceptual Site Model for the FBWU
-------
Record of Decision for the V> SRC-RP-98-t06<>
Ford Building Waste t nit (643-11C) Operable Unit (I') Revision 1
i>a\annah River Site. April 1999 Page 16 of 3-4
beta speciation \vas performed on selected samples. Alpha speciation included
americium-241. radium-226, uranium-234. uranium-235. uranium-238, plutonium-238.
plutonium-239. plutonium-240, plutonium-242. plutonium-244, thorium-228. thorium-230.
and thorium-232; beta speciation included iodine-129, carbon-14. technetium-99.
strontium-90. promethium-147, and radium-228. The sampling program was designed to
establish the presence or absence of hazardous and/or radiological substances at the FBWU.
The maximum detected concentration for each constituent was compared to 2X the average
background concentration to identify unit-specific constituents (USCs). Based on the
analytical data, cesium-137 was targeted for remediation. Using protocols established at the
time, a 2X average background concentration of 0.35 pCi/g for cesium-137 was used as the
/
time-critical removal action cleanup goal (WSRC, 1998a).
Composite confirmatory soil samples were collected during the time-critical removal action
to guide soil removal. Samples were collected from the floors of the excavations as well as
from unexcavated areas around the lip of each excavation (perimeter samples) (Figure 7).
These samples were composite samples of five individual soil aliquots collected in each
sampling area. The composite soil samples were split into two sets. One set was screened
onsite by WSRC for cesium-137 to facilitate decision making during the time-critical
removal action. If the cesium-137 concentration in any sample exceeded the time-critical
removal action cleanup goal, additional soil was removed from that area and the area was
sampled and screened again. If the onsite screening indicated the cesium-137 concentration
was below the time-critical removal action cleanup goal, the excavation stopped and the
remaining split sample set was sent to an US EPA-approved laboratory for analysis and
verification (WSRC, 1998a). The time-critical removal action was considered complete
when the cesium-137 concentrations, as determined by the US EPA-approved laboratory did
not exceed the time-critical removal action cleanup goal of 0.35 pCi/g. Figure 7 shows the
locations of 26 of the 29 composite confirmatory sample locations. The other three samples
were collected from Area D and were removed by subsequent excavation (Figure 7).
Contaminated soil and exhumed tree roots were the only materials removed under the
time-critical removal action. The waste was placed in skid pans and dispositioned to
engineered trenches at the SRS Low Level Radioactive Waste Disposal Facility in E Area
-------
Record of Decision for the ^ SRO-RP-W-4066
Ford Building \\asle Unit (643-1IG) Operable L'nit (U) Rexision I
Sa%annah RKer Site. April 1999 , Page ITpfJM
(WSRC, !998a). The SRS radiological control organization removed the SCA postings and
associated barricades within the unit and declared the unit unrestricted.
After the time-critical removal action, 16 discrete, location-specific surface soil (0 to 0.3 m
[Oto 1 ft] bis) and subsurface soil (0.3 to 1.2m [1 to 4 ft] bis) samples were collected in
December 1997 and analyzed for cesium-137 (borings FBWU-35 to -42). Cesium-137 was
detected in six of the eight surface soil samples. The detected concentrations ranged from a
minimum of 0.07 pCi/g (location FBWU-35) to a maximum of 0.22 pCi/g (location
FBWU-37) with an average surface soil concentration of 0.095 pCi/g. No point sources of
cesium-137 contamination were apparent. Cesium-137 was below method detection limits in
all subsurface samples.
Due to the small areal extent of the unit (<464 m2 [<5,000 ft2]), the surface and near surface
location of the contamination (<3 m [<10 ft] bis), the distance from contamination to the
water table (13.7 to 16.8 m [45 to 55 ft] bis), the high percentage of clays in the top 9.1 m
(30 ft) of soil, and the affinity for cesium-137 to bind to clays, the FBWU was not considered
a likely source of groundwater contamination. Consequently, the investigation of
groundwater was not part of the pre-Work Plan characterization. However, a fate and
transport analyses were performed as part of the RFI/RI/BRA evaluation.
Fate and transport analyses conducted for USCs identified at the FBWU revealed selenium
and potassium-40 exceed the unit-specific soil screening levels. The predicted maximum
concentration in groundwater for both exceeded the corresponding groundwater Applicable,
or Relevant and Appropriate Requirements (ARARs), consequently, selenium and
potassium-40 were retained as preliminary contaminant migration constituents of concern
(CM COCs). Both preliminary CM COCs were eliminated in the uncertainty analysis, and
no final CM COCs were retained at the FBWU.
VI. SUMMARY OF SITE RISKS
As a component of the remedial investigation process, a BRA was prepared for the FBWU.
The BRA consists of human health and ecological risk assessments. Summary information
for the human health and ecological risk assessments follows.
-------
Record of Decision for the \\ SRO-RP-9X-40Mi
Ford Building \\asie I nit (643-1 IGl Operable Unir (L') Revision I
Savannah River Site. April 1999 pa(,c is Of 34
The environmental data used in the risk assessments, including the sample intervals, sample
locations, and sample identification numbers, can be found in RCR.4 Facility
Investigation?Remedial Investigation Report with Baseline Risk Assessment for (he Ford
Building Haste Unit (643-11G) (WSRC, 1998a).
Human Health Risk Assessment
The human health risk assessment characterizes both the potential risk from exposure to
carcinogenic substances and adverse health effects from noncarcinogens to human receptors
exposed to unit-related constituents under current and future land use conditions (Figures 9
and 10). The risks listed in this section were derived from the BRA (WSRC, 1998a) which
used the data obtained from the RFI/RI characterization.
The BRA designates the constituents of potential concern (COPCs) based on a conservative
screen against background concentrations and the relative potential of the chemicals to cause
toxic or carcinogenic effects. Constituents soil concentrations that produce a threshold risk
less than the risk-based concentration levels are screened from further analysis, Threshold
risk is defined as constituent concentrations that exceed either a cancer risk of 1E 10"" or a
hazard quotient (HQ) of 0.1. At the FBWU, identified COPCs included cesium-137 and
beryllium.
Three land use assumptions were made to describe the human receptors that may be exposed
to these constituents. Potential receptors are expected to differ for the current and future land
use scenarios. The possible receptor under the current land use scenario includes the known
on-unit worker. The possible receptors under the future land use scenario include the on-unit
industrial worker and the on-unit resident (adult and child).
Carcinogenic risks are estimated as the incremental probability of an individual developing
cancer over a lifetime as a result of pathway-specific exposure to cancer-causing
contaminants. The risk to an individual resulting from exposure to non-radioactive chemical
carcinogens is expressed as the increased probability of cancer occurring over the course of a
70-year lifetime. Cancer risks are related to the US EPA target risk range of one in ten
thousand (IE 10"4) to one in one million (IE 10'6) for incremental cancer risk at National
Priorities List sites. Risk levels greater than IE 10"6 require a risk management decision
-------
-1 (")
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PKIMARV SKCONDAKY __ ,
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1E-06
IE 115
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Ill
HI
^
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111
1 1)
(
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On-Unit Worker No chemical COPCs in surface soil
Future Industrial Worker
CnrH RitilHin/l InWtftllOn/ „ .
Wnnunil "^ Pxcoono" "*"
Mulumi
DoiuICMKl
tlE-06
<0.l
On-Unit Resident
Fnrrl Binldina Infillftlton/
».,«« H P.-co.«ion WS"""«"«So,i - ,
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InlulnioQ | 'IE-06
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Tuher. Veg. Jngeflmn
Fnut Ingcsttnn
-------
PRIMARY
PRIMARY RKI.EASE
SOURCE MECHANISM
On-Unit Worker
Ford Building
Waste Unit
-
Deposition
SECONDARY
SOURCE
Surtace
Soil
->
Future Industrial Worker
Ford Building
Waste Unit
— »•
Deposition
— »»
Surface
Soil
^
SECONDARY
REI EASE
MECHANISM
Fugitive Dust
Generation
Fugitive Dust
Generation
PATIIWAVS
-*
-*
Air
(Oust)
Air
(Dust)
Exrasi'KF,
ROUTE
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IE-06
IK-M
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ir.»\
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MM.,
Irtgestion
Exlrraal Radiation
-.11; 06
< IE-06
«IE-06
1
-*
On-Unit Resident
Ford Building
Waste Unit
-»•
— t*
Surface
Soil
— •>•
Fugitive Dust
Generation
Biotjc Uptette
Air
(Dust)
1 Biota
1
Inhalation
Hxiemal Radiation ^^^^^H
l^afy Vty Ingcslmn
Tuber Vcg, Ingcilion
Fntit Ingcslion
-.•IE-06
-------
Record of Decision for the NS SRC-RP-98-406*.
Ford Building Waste I nit (643-11G) Operable Unit (U) Revision 1
Savannah River Site. April 1999 J Page 21 of.M
where specific actions to reduce risk may be considered, while cancer risk levels below
1 x 10"h are considered to be insignificant.
Non-carcinogenic effects are also evaluated to identify a level at which there may be concern
for potential non-carcinogenic health effects. The HQ, which is the ratio of the exposure
dose to the reference dose, is calculated for each contaminant. HQs are summed for each
exposure pathway to determine the specific hazard index (HI) for each exposure scenario. If
the HI exceeds unity (1.0), the potential exists that adverse health effects might occur.
The following sections discuss the excess lifetime cancer risk (ELCR) and combined HI
values that were determined in the BRA for current workers, future industrial workers, and
the future residential child/adult. A summary, of the human health risks for the various land
use scenarios is provided in the following sections, Figures 9 and 10, and Tables 1 through 3.
Current Worker
The current worker was evaluated for the 0 to 0.3 m (0 to 1 ft) bis soil interval only. There
are no chemical COPCs in the surface soil at the FBWU. Therefore, chemical carcinogenic
risks and chemical noncarcinogenic hazards were not calculated for the known on-unit
worker (Figure 9). Under the current land use scenario, radiological risks from cesium-137
are characterized for ingestion, external radiation exposure, and inhalation exposure to
surface soil (Figure 10). The total medium risk (TMR) for the known on-unit worker based
on the summation of exposure routes is 6E 10"9. All of the estimated risks are less than IE
106, indicating that radiological risk is insignificant at the unit under current conditions.
Future Industrial Worker
The industrial worker was evaluated for the 0 to 0.3 m (0 to 1 ft) bis and 0 to 1.2 m (0 to 4 ft)
bis soil intervals. Carcinogenic risks and noncarcinogenic hazards associated with beryllium
were calculated for the hypothetical on-unit industrial worker from exposure to redistributed
subsurface soil and air (Figure 9). Radiological risks associated with cesium-137 were
calculated for the hypothetical on-unit industrial worker exposed to cesium-137 in surface
soils and air (Figure 10).
-------
Table 1. Risk Characterization Summary: Current Land Use Scenario - Surface Soil
Medium
Soil
Leafy Vegetables
Tuberous Vegetables
Fruits
Chemical Exposures
Combined Hazard Indt
Combined Cancer Risk
Radiological Exposures
Combined Cancer Risk
Exposure
Route
Ingeslion
Dermal/External
Inhalation
Subtotal
Ingestion
Ingestion
Ingestion
Subtotal
:x:
Chemicals
Noncancer HI
On-Unil
Worker
OE+00 B
OE-f-00 B
OE+00 B
OE+00 B
NA
NA
NA
NA
OE+00 B|
c
Cancer Risk
On-Unil
Worker
OE+00 B
OE+00 B
OE+00 B
OE+00 B
NA
NA
NA
NA
OE+00 B|
c
Radiumiclides
Cancer Risk
On-Unil
Worker
IE-11
6E-09
5E-16
6E-09
NA
NA
NA
NA
6E-09
NA - pathway not evaluated
OE+00 - pathway evaluated but no risks could be calculated due to lack of US EPA-approved toxicity values
B-H! < ! or ELCR < 10"*
E-HI > lor ELCR > 106
£ T- »
O O o
<••»•?
a a. o
32
Si
9
o
•
-------
Table 2. Risk Characterization Summary: Future Land Use Scenarios - Surface Soil
Medium Exposure
Route
Soil Ingestion
Dermal/External
Inhalation
Subtotal
Leafy Vegetables Ingesiion
Tuberous Vegetables Ingestion
Fruits Ingestion
Subtotal
Chemical Exposures
Combined Hazard Index:
Combined Cancer Risk:
Radiological Exposures
Combined Cancer Risk
Noncancer H!
Resident Industrial
Child Adult Worker
OE+00 B OE+00 B OE+00 B
OE+00 B OE+00 B OE+00 B
OE+00 B OE+00 B OE+00 B
OE+00 B OE+00 B OE+00 B
OE+00 B OE+00 B NA
OE+00 B OE+00 B NA
OE+00 B OE+00 B NA
OE+00 B OE+00 B NA
OE+00 B| OE+00 B| OE+00 B
Cancer Risk
Industrial
Resident Worker
OE+00 B OE+00 B
OE+00 B OE+00 B
OE+00 B OE+00 B
OE+00 B OE+00 B
OE+00 B NA
OE+00 B NA
OE+00 B NA
OE+00 B NA
OE+00 B| OE+00 B
Cancer Risk
Industrial
Resident Worker
9E-09 2E-09
7E-06 2F.-06
2E-13 1E-13
7E-06 2E-06
4E-08 NA
8E-08 NA
8E-07 NA
1E-06 NA
8E-06 | 2E-06
NA - pathway not evaluated
OE+00 - pathway evaluated but no risks could be calculated due to lack of US EPA-approved toxicity values
B - HI < 1 or ELCR < 10*
E - HI > 1 or ELCR > 10*
< -i o
w a. o
3 — "<
sf f
« o-
f— 1
•o =. 5
« OS
-O -U
•e V
in
'•" 5- f
°
-------
Table 3. Risk Characterization Summary: Future Land Use Scenarios - Subsurface Soil
Medium Exposure
Route
Soil Ingestion
Dermal/External
Inhalation
Subtotal
Leafy Vegetables Ingestion
Tuberous Vegetables Ingestion
Fruits Ingestion
Subtotal
Chemical Exposures
Combined Hazard Index:
Combined Cancer Risk:
Radiological Exposures
Combined Cancer Risk
Chemicals
Noncancer HI
Resident Industrial
Child Adult Worker
5E-04 B 5E-05 B 2E-05 B
4E-04 B 3E-04 B 1E-04 B
OE+00 B OE+00 B OE+00 B
9E-04 B 3E-04 B 1E-04 B
4E-05 B 3E-05 B NA
3E-05 B 2E-05 B NA
8E-05 B 5E-05 B NA
2E-04 B 9E-05 B NA
1E-03 B| 4E-04 B| 1E-04 B
Cancer Risk
Industrial
Resident Worker
1E-06 B 1E-07 B
3E-06 E 9E-07 B
6E-11 B 2E-H B
4E-06 E 1E-06 B
3E-07 B NA •
2E-07 B NA
5E-07 B NA
1E-06 B NA
5E-06 E| 1E-06 B
Radionuclides
Cancer Risk
Industrial
Resident Worker
OE+00 OE+00
OE+00 OE+00
OE+00 OE+00 '
OE+00 OE+00
OE+00 NA
OE+00 NA
OE+00 NA
OE+00 NA
OE+00 | OEtOO
NA - pathway not evaluated
OE+00 - pathway evaluated but no risks could he calculated due to lack of US EPA-approved loxicity values
B - HI < 1 or PJ.CR < 106
F. - HI > 1 or EI.CR > 10* '
f -n ys
a o n
+ t o
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I co 2.
- E, o
o
o
•o
3^
?
-------
Record of Decision for the W SRC-RP-9JM066
Ford Building \\aste Unit (643-11C) Operable Unit (I!) Revision
Savannah River Site, April 1999 Page 25 of 34
Carcinogenic Risk: For subsurface soil, the TMR for the hypothetical on-unit industrial
worker based on the summation of exposure routes is IE 10'h. All of the estimated risks by
pathway are less than IE 10'6 (ingestion of soil = IE 10'7. dermal contact with soil = 9E 10" .
and inhalation of particulates from soil = 2E 10'"). Under future conditions, chemical risk
for the industrial worker is insignificant at the unit.
Noncarcinogenic Hazard: For subsurface soil, the total cumulative hazard index (TCH1) tor
the hypothetical on-unit industrial worker based on the summation of exposure routes is 1E
10"4. The His for all pathways are well below 1. All of the estimated hazards by pathway are
well below I. Under future conditions, chemical hazard for the industrial worker is
insignificant at the unit.
Radiological Risk: For surface soil, the TMR for the hypothetical on-unit industrial worker
based on the summation of exposure routes is 2E 10'6. Radiological risks were estimated for
three soil exposure routes: ingestion of soil (2E 10"9); direct, external radiation exposure from
soil (2E 10'6); inhalation of particulates from soil (IE 10"13). Cesium-137 is a preliminary
COC for the external radiation exposure pathway.
Residential Adult/Child
The residential scenario was evaluated at the 0 to 0.3 m (0 to 1 ft) bis and the 0 to 1.2 m
(0 to 4 ft) bis soil intervals. Under the future land use scenario, carcinogenic risks and
noncarcinogenic hazards associated with beryllium were calculated for the hypothetical
on-unit resident (adult and child) from exposure to redistributed subsurface soils, air, and
homegrown produce (Figure 9). Radiological risks associated with cesium-137 were
calculated for the hypothetical on-unit resident from exposure to surface soils, air, and
homegrown produce (Figure 10).
Carcinogenic Risk: For subsurface soil, the total cumulative risk (TCR) for the hypothetical
on-unit resident based on the summation of exposure routes and media is 5E 10"6 (soil TMR
= 4E 10'6, produce TMR = IE 10'6). Estimated risks equal or exceed IE 10 for both soil and
produce pathways. Chemical risks were estimated for three soil exposure routes: ingestion
of soil (IE 10~6), dermal contact with soil (3E 10"6), and inhalation of particulates from soil
-------
Record of Decision for «hc \VSRC-RP-98-4066
Ford Building \\ astc Unit (643-11C) Operable Unit (C') Revision !
Savannah River Site. April 1999 Papc 26 of J4
(6E 10 ). Chemical risks were estimated for three produce exposure routes: ingestion of
leafy vegetables (3E 10 ), ingestion of tuberous vegetables (2E 10 ), and ingestion of fruits
(5E 10 ). Beryllium is a preliminary COC for the dermal contact and ingestion pathways.
Noncarcinogenic Hazard: Based on the summation of exposure routes and media, the TCHIs
for the hypothetical on-unit resident child and adult are IE 10" and 4E 10 , respectively.
The His for all pathways are well below 1, indicating that chemical hazard for the
hypothetical on-unit resident is insignificant.
Radiological Risk: For surface soil, the TCR for the hypothetical on-unit resident based on
the summation of exposure routes and media is 8E 10"6 (soil TMR = 7E 10"*, produce TMR =
IE 10'*). Radiological risks were estimated for three soil exposure routes: ingestion of soil
(9E 10*9); direct, external radiation exposure from soil (7E 10"6); inhalation of particulates
from soil (2E 10'n). Radiological risks were estimated for three produce exposure routes:
ingestion of leafy vegetables (4E 10"8), ingestion of tuberous vegetables (8E 10"8), and
ingestion of fruits (8E 10"7). Cesium-137 is a carcinogenic preliminary COC for the external
radiation pathway.
Ecological Risk Assessment
The ecological BRA for the FBWU evaluated the likelihood of harmful effects to ecological
receptors from exposure to contaminants in soil. Ecological receptors serve as assessment
endpoints for the risk to plant and animal populations and ecosystems at FBWU.
COPCs are those constituents whose maximum measured concentrations exceeded a toxicity
screening value for ecological receptors and 2X the background mean concentration. No
ecological COPCs were identified from among constituents detected at FBWU. Therefore,
all exposure pathways are incomplete and the calculation of ecological HQs for current and
future exposure of ecological receptors was not required. Consequently, no preliminary
COCs were carried forward into the uncertainty analysis and no ecological final COCs were
retained.
-------
Record of Decision for the « SRC-RP-98-4066
Ford Building \\astelnit (6-JJ-l 1C) Operable Unit (l:) RCMSIOH I
Sa%annah River Site. April 1999 ; ; Page 27 of.Vi
Uncertainty
Preliminary' CM COCs identified by the fate and transport analyses and preliminary COCs
identified during the risk assessment are evaluated through an uncertainty analysis to
determine final COCs. Remedial goal options (RGOs), which become the basis of and the
focus for remediation are developed for the list of final COCs.
Fate and transport analyses identified selenium and potassium-40 as preliminary CM COCs.
The human health risk assessment identified no preliminary COCs for surface soil under the
current land use. Under future industrial land use, cesium-137 was identified as a
preliminary COC for surface soil. Under future residential land use. cesium-137 was
identified as a preliminary COC for surface soil, and beryllium was identified as a
preliminary COC for subsurface soil.
Following the uncertainty analysis, no constituents were retained as final COCs and no
RGOs were developed. Key uncertainties for each preliminary COC are summarized below.
Potassium-40 was not retained as a final CM COC for the following reasons:
• At the FBWU, potassium-40 concentrations range from 0.83 pCi/g to 3.51 pCi/g. The
observed range in background values is virtually identical, 0.76 pCi/g to 3.5 pCi/g. There
does not appear to be a difference between the observed unit and background values and,
using present protocols, both unit and background data sets fail the background screen.
• Potassium-40 is a naturally occurring radionuclide present in soils at the SRS. There is
no process history of potassium-40 use associated with FBWU and no reason to postulate
that it would be associated with the regulated activities that are suspected to have
occurred there.
• Potassium-40 was detected in all of the unit samples analyzed. The values that exceed
the 2X background screen are greater than 1.2 m (4 ft) deep and are probably associated
with natural soil profile development. They are not near the surface where the primary
source for this unit was located.
-------
Record of Decision for the \VSRC-RP-98-10h6
Ford Building \\ astc I/nil (6-4.VI 1C) Operable Unit (U) R<^ i^ion I
Sa\annah River Site. April 199
-------
Record of Decision for the
Ford Building Waste Unit (643-11G) Operable Unit (U) Ko tMim I
Savannah River Site. April 1999 ^ ' I'.i^i :'' »l .U
• Beryllium is a preliminary COC in subsurface soils at the FBWU t'or the hypothetical
future resident scenario only. The cancer risk associated with this preliminary COC is 4E
10"6. Background risk associated with beryllium for the future resident yields a similar
value (2E 10'6).
Cesium-137 was not retained as a final COC for the following reasons:
• Only 1 of the 8 surface soil samples from the discrete, post-removul sampling event in
December 1997 slightly exceeded the 2X average background value for cesium-137 (i.e..
0.22 pCi/g unit vs. 0.19 pCi/g background). Cesium-137 was not detected in subsurface
soils.
• The single cesium-137 value that exceeded 2X background is located on the perimeter of
the waste unit and represents backfill from the Central Shops Borrow Pits.
• Cesium-137 background values for surface soil at the Central Shops Burning Rubble Pits.
which are adjacent to the Borrow Pit, ranged from 0.101 - 0.338 pCi/g. The maximum
unit value of 0.22 pCi/g for cesium-137 is within this range.
• Cesium-137 background values from 16 waste sites at SRS were reviewed. As reported
in the Preliminary Background Soils Study Report (US DOE. 1996), the 2X average
background value for cesium-137 in surface soils is 0.213 pCi/g with a maximum
background value of 0.57 pCi/g. The 90th percentile for the SRS background surface soils
is 0.258 pCi/g for cesium-137. Thus, 1 out of 10 background samples would be expected
to be greater than 0.258 pCi/g. The maximum FBWU unit value of 0.22 pCi/g out of 8
samples is consistent with the observed background.
• A statistical review of the unit dataset from the 8 discrete post-removal samples and the
background dataset indicates that the mean concentrations of cesium-137 are not
statistically different (i.e., mean background concentration is 0.094 pCi/g and mean unit
concentration is 0.099 pCi/g).
• The risk from the FBWU and the unit background are similar. Both the FBWU unit risk
and the unit background risk for the Industrial Worker is 2E 10 h tor external exposure to
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Record of Decision for the WSRC-RP-98-J066
Ford Building SVasteLnic (643-11G) Operable Unit(L') Revision I
Savannah River Site. April 1999 Page 30 of 34
surface soil. Residential risk for external exposure to unit surface soil is 7E 10"n and 5E
10'" for exposure to unit background surface soil.
Because no final COCs were identified, no RGOs were developed for the FBWU.
VII. CONCLUSIONS
Fate and transport analyses identified two preliminary CM COCs (potassium-40 and
selenium). No human health preliminary COCs were identified under current land use
assumptions. Preliminary COCs were identified for the hypothetical industrial worker
(cesium-137) and hypothetical on-unit resident (cesium-137 and beryllium). Due to the
elimination of both preliminary CM COCs and both human health preliminary COCs through
the uncertainty analysis process, no final COCs were retained. Because no final CM COCs,
ecological final COCs, or human health final COCs were identified, any residual soil
contamination at the unit does not pose a future risk to groundwater, a current or future risk
to ecological receptors, or a current or future risk to human health.
Site-Specific Considerations
Site-specific considerations, based on the conclusions of the BRA and RFI/R1, which suggest
no potential for significant risk include:
1) All surface debris was removed from the unit sometime prior to 1992, and no primary
sources of contamination remain.
2) The concentrations of constituents in the soil after the time-critical removal action are
indistinguishable from the background data.
3) Fate and transport analyses indicate that the unit does not represent a current or future
risk to groundwater.
4) The BRA did not identify any final COCs after the uncertainty analysis; therefore, any
residual soil contamination at the unit does not pose a current or future risk to human
health.
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Record of Decision for the WSRC-RP-M-1066
Ford Building Waste I nit (643-11C) Operable Unit (U) Revision I
Savannah River Site. April 1999 Page 31 of 34
Remedial Action Objectives
Remedial action, objectives (RAOs) specify USCs, media of concern, potential exposure
pathways, and remediation goals. Remediation goals are developed based upon ARARs or
RBCs. After the uncertainty analysis, the BRA determined that there are no unit-specific
contaminants. Therefore, there are no RAOs. "No Further Action" will be protective of
human health and the environment.
Description of "No Further Action" Decision
According to the US EPA guidance document Guidance on Preparing Superfund Decision
Documents (US EPA, 1989), if there is no current or potential threat to human health or the
environment and no action is warranted, the CERCLA Section 121 requirements are not
triggered. This means that there is no need to evaluate other alternatives or the "No Further
Action" remedy against the nine criteria specified under CERCLA.
Under "No Further Action", no treatment will be performed, no institutional controls or
engineering controls will be implemented, and no cost will be associated with the remedy.
Because no remedial action is being chosen in this ROD, the requirements of CERCLA
Section 121 are not triggered and an ARARs analysis is not required.
Based on the RFI/RJ/BRA, the FBWU poses no significant risk to human health and the
environment. Therefore, "No Further Action" has been selected as the remedy that satisfies
the CERCLA criteria. "No Further Action" is the final action for the FBWU operable unit.
This solution is meant to be permanent and effective in both the short and long term and is
applicable to all media evaluated (soil, groundwater, etc.). The "No Further Action" decision
is the least cost option with no capital, operating, or monitoring costs, and is protective of
human health and the environment.
This proposal is consistent with US EPA guidance and is an effective use of risk management
principles. The Statement of Basis/Proposed Plan provided for involvement with the
community through a document review process and a public comment period.
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Record of Decision for the \\SRC-RP-98-4066
Ford Building Waste Unit (643-11G) Operable Unit (U) Revision I
Savannah River Site, April 1999 Page 32 of 34
The selected remedy is protective of human health and the environment and complies with
federal and state requirements that are legally applicable or relevant and appropriate to the
remedial action.
VIII. EXPLANATION OF SIGNIFICANT CHANGES
The Statement of Basis/Proposed Plan and draft permit modification provide for involvement
with the community through a document review process and a public comment period. No
comments were received during the public comment period; therefore, no changes were made
based on public comments.
IX. RESPONSIVENESS SUMMARY
No comments on the Statement of Basis/Proposed Plan were received from the public during
the public comment period. Therefore, a Responsiveness Summary was not prepared.
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. rr. . . , .. \\SRC-RP-9H-J066
Record of Decision for the ..
Ford Building %Vaste Unil (643-I1G) Operable Unit (U) l, ^'"ru
Savannah River Site. April 1999 _ ge " ° '
X. REFERENCES
FFA, 1993. Federal Facility Agreement for the Savannah River Site. Administrative Docket
No. 89-05-FF, Effective Date: August.
US DOE, 1994. Public Involvement, A Plan for Savannah River Site. United States
Department of Energy, Savannah River Operations Office, Aiken South Carolina.
US DOE, 1996. Preliminary Background Soils Study Report. Rev. 0. United States
Department of Energy, Savannah River Operations Office, Environmental Restoration
Division, November.
US EPA, 1989. Guidance on Preparing Superfund Decision Documents. Office of Solid
Waste and Emergency Response - OSWER Directive 9355.3-02, Washington, DC, July
WSRC, 1997. Removal Site Evaluation Report for Soil Removal at the Ford Building
Waste Unit (643-1 IN) (U), WSRC-RP-96-850, Rev. 1, Westinghouse Savannah River
Company, Aiken, South Carolina, February.
WSRC, 1998a. RCRA Facility Investigation/Remedial Investigation with Baseline Risk
Assessment far the Ford Building Waste Unit (643-11C), WSRC-RP-97-190, Rev. 1,
Westinghouse Savannah River Company, Aiken, South Carolina, May.
WSRC, 1998b. Statement of Basis/Proposed Plan for the Ford Building Waste Unit
(643-11G) Operable Unit (U), WSRC-RP-98-4065, Rev. 1, Westinghouse Savannah
River Company, Aiken, South Carolina, October.
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Record of Decision Tor the
Ford Building \\aste Unit (643-1 IG) Operable Unit (U)
Savannah River Site, April 1999
\\SRC-RP-98-4066
Revision I
Page 34 of 34
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