EPA/ROD/R04-02/097
2002
EPA Superfund
Record of Decision:
SAVANNAH RIVER SITE (USDOE)
EPA ID: SC1890008989
OU 22, 32, 48, 49
AIKEN, SC
09/26/2002
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United States Department of Energy
Savannah River Site
Record of Decision
Remedial Alternative Selection for the
General Separations Area Consolidation Unit (U)
WSRC-RP-2002-4002
Revision 0
Augttst 2i§2
by;
Westiiigh«use Savannah River Company LLC
Suvjuiiuih River Site
Aflun,SC
Prepirrf for VJi. D»p*ri»«ni of Energy amlw Cwntnct N*. Df/>AC09-96SRllSOI
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August 2002
DISCLAIMER
This report wis prepared, by WcstingbouK Savannah River Company LLC
fWSRC) for the United State* Department of Energy under Contract No.
DE-AC09-94SR18SOO »nd if mi aeewmt «f work performed under that
contract. Reference herein to any ipeeifk eonwfflerci»l ^r&duct, procest, «•
services by trademark, name, manufacturer or otherwise does not
necMsarHy constitute or imply endorsement, reconunendation, or favoring of
same by WSRC or the United 5t«t« Government or any agency thereof.
Printed in the Unitecl Steles of America
Prepared for
U.S. Department of En ergj
and
We»llngli«isf Savannah River Compjray LLC
Aik«n« South Carolina
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Savannah Rtor Site
August 2002
RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
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August 2002 Declaration 1 of 8
DECLARATION FOR THE RECORD OF DECISION
Unit Name and Location
The General Separations Area Consolidation Unit includes the following waste units:
H-Area Retention Basin (281-3H) and Spill on 05/01/1956 of Unknown Amount of
Retention Basin Pipe Leak (NBN)
Warner's Pond (685-23G) and Spill on 03/08/1978 of Unknown Seepage Basin Pipe
Leak in H-Area Seepage Basin (NBN) and Spill on 02/08/1978 of H-Area Process Sewer
Line Cave-In (NBN)
HP-52 Ponds
Old Radioactive Waste Burial Ground (Including Solvent Tanks) (643-E)
Comprehensive Environmental Response, Compensation and Liability Information System
(CERCLIS) Identification Numbers: OU-22, OU-48, OU-49, and OU-32
Comprehensive Environmental Response, Compensation and Liability Act (CERCLA)
Identification Number: SCI 890 008 989
Savannah River Site
Aiken, South Carolina
United States Department of Energy
The General Separations Area Consolidation Unit (GSACU) consists of four primary waste
units: H-Area Retention Basin (281-3H) (HRB), Warner's Pond (685-23G), HP-52 Ponds, and
the Old Radioactive Waste Burial Ground (643-B) (ORWBG) including its 22 underground
storage tanks known as the Old Solvent Tanks (650-0IE through 650-22E) (OSTs). The
Warner's Pond unit also includes a portion of the H-Area Inactive Process Sewer Line (HIPSL).
Collectively, these waste units are identified as a single operable unit (OU) because of their
proximity to each other and similar health and environmental threats. The unit is listed as a
Resource Conservation and Recovery Act (RCRA) 3004(u) Solid Waste Management
Unit/CERCLA unit in Appendix C of the Federal Facility Agreement (FFA) for the Savannah
River Site (SRS). The media associated with the GSACU are soil, sediment, and debris.
Statement of Basis and Purpose
This decision document presents the selected remedy for the GSACU, located at the SRS near
Aiken, South Carolina. The remedy was chosen im accordance with CERCLA, as amended by
the Superfund Amendments Reauthorization Act (SARA), and, to the extent practicable, the
National Oil and Hazardous Substances Pollution Contingency Plan p4CP). This decision is
based on the Administrative Record File for this site,
The South Carolina Department of Health and Environmental Control (SCDHEC) and the
United States Environmental Protection Agency (USEPA) concur with the selected remedy.
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Assessment of the Site
The response action selected in this Record of Decision (ROD) is necessary to protect the public
health or welfare or the environment from actual or threatened releases of hazardous substances,
pollutants or contaminants into the environment.
Description of the Selected Remedy
The selected remedy for HRB, Warner's Pond, and HP-52 Ponds is Alternative 7 (Consolidation
at the ORWBG) and the selected remedy for the ORWBG is Alternative ORWBG VI
(Institutional Controls with Low Permeability Cap). Individual intruder barriers will be installed
over the long-lived persistent radioactive hot spots in the ORWBG (HS-500-1 through
HS-500-8) before institutional controls are terminated at the ORWBG. The options of in situ
stabilization of HS-Hg-1 and removal of the radioactive hot spots in the ORWBG will not be
implemented.
Principal threat source material (PTSM) is present at HRB, Warner's Pond, HP-52 Ponds, and
ORWBG. At HRB, Warner's Pond, and HP-52 Ponds, PTSM (and soil containing contaminant
migration constituents of concern [CMCOCs]) will be removed to the extent practicable. At the
ORWBG, treatment or removal of the PTSM is not practicable; consequently, engineering
controls, including containment, will be used to manage the PTSM.
The selected remedy includes the following activities:
1. Excavate materials constituting industrial PTSM and soil containing CMCOCs above
remedial goals (RGs) at HRB, Warner's Pond, and HP-52 Ponds to the extent practicable.
The excavation will not breach the integrity of the hardpan. Soil RGs for CMCOCs are
established to prevent leaching of constituents to groundwater at concentrations above
maximum contaminant levels (MCLs) within 1,000 years. Table Sb provides additional
explanation regarding the generation of soil RGs for CMCOCs.
2. Manage standing surface water (in HRB) and water that accumulates during excavation
by solidi6cation and consolidation with the excavated soil and/or by another means such
as treatment at the Effluent Treatment Facility (ETF).
3. Consolidate the excavated soil and material by transferring it to the areas of the ORWBG
that have not yet been covered by the native soil cover (e.g., over the OSTs). In the
unlikely event that there is insufScient available space at the ORWBG, ship the excess
waste to an off-SRS facility approved to receive CERCLA remediation waste.
4. When inactive pipelines are encountered during removal of soil, excavate those sections
of the pipelines with the soil. At Warner's Pond, this will include the inactive CERCLA
pipelines within the berms, the diversion box, and the RCRA-regulated HIPSL.
Characterization data show that soil around the HIPSL is non-hazardous. Sections of the
HIPSL and any contents will be sampled and analyzed during the characterization of
Warner's Pond to determine if they are hazardous in accordance with South Carolina
Hazardous Waste Management Regulation R.61-79.261, If the HIPSL pipeline or its
contents are hazardous, these materials will not be consolidated into the ORWBG. A
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RCRA Closure Plan will be developed to document the disposition of the RCRA
pipeline. The RCRA closure plan will be approved by SCDHEC prior to remedial action
on the HIPSL (indicated in yellow on Figure 4).
For remaining intact portions of inactive pipelines, including portions that are not in
contact with PTSM or cannot be readily removed (such as the section of the HIPSL under
the railroad track), plug the ends of the pipelines and grout in place. If a pipeline is not
intact, cannot be reliably grouted in place, and is non-hazardous, remove it and
consolidate it with the soil transferred to the ORWBG. Risks posed by remnant
contamination in soil after excavation will be determined prior to backfilling.
5. Consolidate any vegetation in contact with PTSM by removing it and transferring it to
the ORWBG. Vegetation will be shredded, chipped, or spatially distributed and
incorporated into the excavated soil. Placement of this material at ORWBG will be
engineered in a manner that minimizes subsidence.
6. Evaluate the risk of remnant material after excavation at HRB, Warner's Pond, and
HP-52 Ponds. Contaminant migration risk from the potential source to the Upper Three
Runs Aquifer (UTRA) beneath each unit will be evaluated.
7. Mitigate residual risk at HRB, Warner's Pond, and HP-52 Ponds by backfilling and
placing clean soil over open excavations that contain residual contamination exceeding
RGs. A soil cover will be used to minimize infiltration so that (1) no unit-related
contaminants will cause MCL exceedances in the UTRA beneath each unit, and (2) the
accumulation of perched water atop the hardpan is minimized.
8. Restore surface water drainage at Warner's Pond to a natural state by removing the berms
that cause ponding of water.
9. Prepare a post-construction report for HRB, Warner's Pond, and Hp-52 Ponds to
summarize the remediation activities and summarize how residual risks are addressed.
10. Implement institutional controls at HRB, Warner's Pond, and HP-52 Ponds. Institutional
controls will consist of site maintenance (site inspections, mowing, general
housekeeping, repair of erosion damage, and other routine maintenance as needed) and
access controls (warning signs and land use restrictions). Institutional controls will
include continued use of SRS's Site Use and Site Clearance Programs to restrict
disturbance of the cover system and waste at each unit and to prevent drinking water use
of contaminated groundwater under each unit.
11. Construct a low-permeability geosynthetic cover system (with a soil hydraulic
conductivity of <1 x 10"7 cm/sec) over the ORWBG; including the areas where
consolidated materials from HRB, Warner's Pond, and HP-52 Ponds were placed; but
excluding the areas between interim covers B and D. A hydraulic conductivity of <1 x
10"7 cm/sec is selected because it provides infiltration control that sufficiently manages
uncertainties related to residual contamination without further investigation, and it is
consistent with low permeability caps placed over similar facilities at SRS. Contiguous
facilities associated with SRS's active Solid Waste Management Program (such as
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643-7E/643-SE and associated paved parking areas) will not be covered by the cap.
These facilities will continue to actively support SRS solid waste activities at least until
all transuranic waste stored at SRS has been shipped to the Waste Isolation Pilot Plant
(WIPP),
12. Implement institutional controls at the ORWBG. Institutional controls will consist of site
maintenance (site inspections, mowing, general housekeeping, repair of erosion damage,
other routine maintenance as needed, and periodic maintenance of the infiltration control
system) and access controls (security fences, warning signs, and land use restrictions).
Institutional controls will include continued use of SRS's Site Use and Site Clearance
Programs to restrict disturbance of the cover system and waste at the unit and to prevent
drinking water use of contaminated groundwater under the unit.
13. Before institutional controls are terminated at the ORWBG, install intruder barriers over
the long-lived persistent radioactive hot spots (hot spots HS-500-1 through HS-500-8) to
deter inadvertent human intrusion. The likely configuration of the intruder barrier is
heavy rip-rap. The barrier will be installed above the low permeability cap but beneath a
soil cover. Covering the rip rap will minimize development of an undesirable habitat
(e.g., a habitat among rip-rap favorable for deep-rooting plants and burrowing animals
that could degrade the low permeability cap). Placement of the barrier will not interfere
with the long-term integrity of the cap, A reasonable estimated timeframe for installing
the intruder barrier is 100 years. The barrier will not be installed until institutional
controls are terminated; the United States Department of Energy (USDOE) expects to
maintain institutional controls at the Burial Ground Complex for at least 100 years.
For HRB, the scope of the response action is to remediate the basin bottom/sidewalls, the bam
around the basin, the soil pile, the 75-ft section of process sewer line from the operational
diversion box to the basin, the 100-ft long discharge sewer line, and the discharge area including
a concrete spillway to the effluent stream. The area inside the boundary of HRB formerly
identified as a Site Evaluation Area (SEA) (Spill on 05/01/1956 of Unknown Amount of
Retention Basin Pipe Leak) is part of HRB and is included in the response action. The diversion
box is still operational and is not included in the scope of the remediation. The existing effluent
stream south of the unit to which the basin discharged has been characterized in the vicinity of
HRB. However, this stream is not included in the scope of this remedial action because it is
primarily contaminated by upgradient sources in H Area unrelated to HRB. The effluent stream
is being addressed separately as part of the RCRA/CERCLA characterization of the upgradient
facilities and the integrator operable unit (IOU) program. Although contaminated with
radionuclides and inorganics, groundwater in the aquifer under the unit (the UTRA) is not
included in the scope of this response action because no unit-related groundwater contaminants
have been identified. Groundwater is not part of this unit; it is being addressed separately under
the H-Area Groundwater Operable Unit (HAGOU).
For Warner's Pond, the scope of the response action is to remediate the former pond area
(including the asphalt area and the berms), an 850-ft segment of the HIPSL (including manholes
and the diversion box), and other inactive pipelines in the asphalt area and berms, The areas
within the boundary of the Warner's Pond area formerly identified as SEAs (Spill on 03/08/1978
of Unknown Seepage Basin Pipe Leak in H-Area Seepage Basin [NBN] and Spill on 02/08/1978
of H-Area Process Sewer Line Cave-In [NBN]) are part of the Warner's Pond unit and are
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included with the response action. The effluent stream that has been diverted around the former
pond area is not included in the scope of this remedial action because the stream is primarily
contaminated by upgradient sources. The effluent stream is being addressed separately as part of
the RCRA/CERCLA characterization of the upgradient facilities and the IOU program. The
groundwater at Warner's Pond is contaminated with radionuclides and inorganics, although these
contaminants cannot be attributed with certainty to the waste unit. Groundwater in the UTRA is
not included io the scope of this response action. Groundwater is not part of this unit; it is being
addressed separately under the HAGOU,
For HP-52 Ponds, the scope of the response action is to remediate the two former pond areas, the
old effluent ditch, several soil piles at the unit that resulted from re-positioning and covering of
contaminated soils in the area, and contamination in the historic drainage channel near the
former beaver pond. The active regulated effluent stream that has been diverted around the
former pond area is not included in the scope of this remedial action because the stream is fed by
on-going H-Area facility operations with a potential for contamination. This active effluent
stream is being addressed separately as part of the RCRA/CERCLA characterization of the
upgradient facilities and the IOU program. Although contaminated with radionuclides and
inorganics, groundwater in the UTRA is not included in the scope of this response action
because the groundwater does not appear to have been affected by this unit. Groundwater is not
part of this unit; it is being addressed separately under the HAGOU,
For ORWBG, the scope of the response action is to address the waste buried at depth in the unit
and to implement a final action for the OSTs. The scope of the action excludes the areas between
interim covers B and D because these areas are actively supporting SRS's solid waste
management operations including the "ship-to-WIPP" program. There is no contaminated
surface water at the ORWBG. Groundwater in the vicinity of the ORWBG has been
contaminated by releases from the various facilities in the Burial Ground Complex, including the
ORWBG. The contaminated groundwater is not included in the scope of this response action
because it is being addressed by the corrective action program in the SRS RCRA Part B permit
for the Mixed Waste Management Facility (F) in accordance with Settlement Agreement
87-52-SW.
A separate remedial action will be necessary for miscellaneous areas of the Burial Ground
Complex which are not included in the remedy for the GSACU. This separate action will address
the area of the operational Solid Waste Management Division buildings, including underlying
trenches, in the ORWBG and the non-hazardous waste portion of the Low Level Radioactive
Waste Disposal Facility (643-7E) (including Combined Spills from ORWBG as reported in
WSRC-RP-97-419).
lOUs are defined as surface water bodies (e.g., SRS streams, Savannah River) and associated
wetlands, including the water, sediment, and related biota. These surface water bodies are
referred to as "integrator" OUs because they represent the integration of potential contamination
discharged to surface water or migrating through groundwater from source OUs, SEAs, National
Pollutant Discharge Elimination System outfalls, and operational facilities to points of potential
receptor exposure. The GSACU is within the Fourmile Branch and Upper Three Runs
watersheds. Several source control and groundwater OUs within these watersheds will be
evaluated to determine effects, if any, to associated streams and wetlands. SRS will manage all
OUs to mitigate impact to the lOUs. SRS's actions to address contamination at HRB, Warner's
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Pond, and HP-52 Ponds serve to mitigate potential impacts to nearby streams. Upon disposition
of all OUs, a final comprehensive ROD for each IOU will be pursued with additional public
involvement.
SCDHEC has modified the SRS RCRA permit to incorporate the Institutional Controls with Low
Permeability Cap remedy for the ORWBG.
Statutory Determinations
Based on the RCRA Facility Investigation/Remedial Investigation (RFI/RI) reports and Baseline
Risk Assessments (BRAs), the GSACU poses a threat to human health and the environment.
Therefore, Alternative 7 for HRB, Warner's Pond, and HP-52 Ponds (Consolidation at the
ORWBG) and Alternative ORWBG VI for the ORWBG (Institutional Controls with Low
Permeability Cap) have been selected as the remedies for the GSACU.
Section 300A30(f)(2) of the NCP requires that a five-year remedy review of the ROD be
performed if hazardous substances, pollutants, or contaminants above levels that allow for
unlimited use and unrestricted exposure remain in the OU. The three parties - SCDHEC,
USEPA, and USDOE - have determined that a five-year review of the ROD for the GSACU will
be performed to ensure that the remedy continues to provide adequate protection of human
health and the environment.
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 (unless justified by a waiver), is cost-effective, and utilizes permanent solutions and
alternative treatment (or resource recovery) technologies to the maximum extent practicable.
There is a statutory preference for treatment as a principal element of a remedy to the extent
practicable. Although treatment is not part of the remedy for the GSACU, PTSM will be
removed from HRB, Warner's Pond, and HP-52 Ponds. For the ORWBG treatment of the
principal threats including the radioactive hot spots and HS-Hg-1 is not practicable. However,
use of engineering controls (such as containment through capping) combined with institutional
controls is protective of human health and the environment and is consistent with expectations in
the NCP.
Because this remedy will result in hazardous substances remaining onsite above levels that
allow for unlimited use and unrestricted exposure, a review will be conducted within five years
after initiation of remedial action to ensure that the remedy continues to provide adequate
protection of human health and the environment.
The selected remedy leaves hazardous substances in place that pose a potential future risk and
will require land use restrictions for an indefinite period of time. As negotiated with USEPA, and
in accordance with USEPA-Region IV policy (Johnston 1998), SRS has developed a Land Use
Control Assurance Plan (LUCAP) (WSRC 1999) to ensure that land use restrictions are
maintained and periodically verified. A unit-specific Land Use Control Implementation Plan
(LUCIP) will provide detail and specific measures required for the land use controls selected as
part of this remedy. USDOE-Savannah River Operations Office is responsible for implementing,
maintaining, monitoring, reporting upon, and enforcing the land use controls under this ROD.
The LUCIP selected as part of this action will be submitted concurrently with the Corrective
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Measures Implementation/Remedial Action Implementation Plan (CMI/RAIP), as required in the
FFA, for review and approval by USEPA and SCDHEC. Upon 6nal approval, the LUCIP will be
appended to the LUCAP and is considered incorporated by reference into the ROD, establishing
Land Use Controls (LUC) implementation and maintenance requirements enforceable under
CERCLA. The approved LUCIP will establish implementation, monitoring, and maintenance,
reporting, and enforcement requirements for the unit. The LUCIP will remain in effect until
modified as needed to be protective of human health and the environment. LUCIP modification
will only occur through another CERCLA document.
USDOE expects to retain control of the GSACU for the foreseeable future, and the future land
use is anticipated to be the same as the current land use (industrial). However, in the unlikely
case the property is transferred to nonfederal ownership, the US Government will take those
actions necessary pursuant to Section 120(h) of CERCLA. Those actions will include a deed
notification disclosing former waste management and disposal activities as well as remedial
actions taken on the site. The contract for sale and the deed will contain the notification required
by CERCLA Section 120(h). The deed notification shall, in perpetuity, notify any potential
purchaser that the property has been used for the management and disposal of waste. These
requirements are also consistent with the intent of the RCRA deed notification requirements at
final closure of a RCRA facility if contamination will remain at the unit.
The deed shall also include deed restrictions precluding residential use of the property. However,
the need for these deed restrictions may be reevaluated at the time of transfer in the event that
exposure assumptions differ and/or the residual contamination no longer poses an unacceptable
risk under residential use. Any reevaluation of the need for the deed restrictions will be done
through an amended ROD with USEPA and SCDHEC review and approval.
In addition, if the site is ever transferred to nonfederal ownership, a survey plat of the OU will be
prepared, certified by a professional land surveyor, and recorded with the appropriate county
recording agency.
Data Certification Checklist
This ROD provides the following information:
• Constituents of concern (COCs) and their respective concentrations
• Baseline risk represented by the COCs
Cleanup levels established for the COCs and the basis for the levels
Current and future land and groundwater use assumptions used in the risk assessments
and ROD
• Land and groundwater use that will be available at the site as a result of the selected
remedy
Estimated capital, operation and maintenance, and total present worth cost; discount rate;
and the number of years over which the remedy cost estimates are projected
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Decision factor(s) that led to selecting the remedy (i.e., describes how the selected
remedy provides the best balance of tradeoffs with respect to the balancing and
modifying criteria)
How source materials constituting principal threats are addressed
Date
Acting Manager
U. S. Department of Energy, Owner and Co-operator,
Savannah River Operations Office
D\te
Richard D. Crreen
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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August i
DECISION SUMMARY
REMEDIAL ALTERNATIVE SELECTION (U)
General Separations Area Consolidation Unit
WSRC-RP-2002A002
Rev. 0
August 2002
Savannah River Site
Aiken, South Carolina
Prepared By:
Westinghouse Savannah River Company LLC
for the
U. S. Department of Energy under Contract DE-AC09-96SR18509
Savannah River Operations Office
Aiken, South Carolina
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TABLE OF CONTENTS
SECTION PAGE
LIST OF APPENDICES ii
LIST OF FIGURES iii
LIST OF TABLES iii
LIST OF ACRONYMS AND ABBREVIATIONS iv
I. SAVANNAH RIVER SITE AND OPERABLE UNIT NAME, LOCATION,
AND DESCRIPTION 1
II. SITE AND OPERABLE UNIT COMPLIANCE HISTORY 3
III. HIGHLIGHTS OF COMMUNITY PARTICIPATION 16
IV. SCOPE AND ROLE OF THE OPERABLE UNIT WITHIN THE SITE
STRATEGY 17
V. OPERABLE UNIT CHARACTERISTICS 20
VI. CURRENT AND POTENTIAL FUTURE SITE AND RESOURCE USES 31
VII.. SUMMARY OF OPERABLE UNIT RISKS 32
VIII. REMEDIAL ACTION OBJECTIVES AND REMEDIAL GOALS 36
IX. DESCRIPTION OF ALTERNATIVES 41
X. COMPARATIVE ANALYSIS OF ALTERNATIVES 47
XI THE SELECTED REMEDY 64
XII. STATUTORY DETERMINATIONS 75
XIII. EXPLANATION OF SIGNIFICANT CHANGES 76
XIV. RESPONSIVENESS SUMMARY 76
XV. POST-ROD DOCUMENT SCHEDULE AND DESCRIPTION 76
XVI. REFERENCES 78
LIST OF APPENDICES
APPENDIX A - RESPONSIVENESS SUMMARY Al
APPENDIX B - COST ESTIMATES FOR THE SELECTED REMEDY B1
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LIST OF FIGURES
FIGURE 1. LOCATION OF THE GSACU AT SRS 2
FIGURE 2. OBLIQUE AERIAL PHOTOGRAPH OF WARNERS POND, AND
HP-52 PONDS 6
FIGURES. MAPOFHRB 7
FIGURE 4. MAP OF WARNER'S POND 9
FIGURE 5. MAP OF HP-52 PONDS 11
FIGURE 6. MAP OF OSTs, MERCURY HOT SPOT, AND 100-YEAR
RADIOACTIVE HOT SPOTS IN THE ORWBG 12
FIGURE?. MAP OF 500-YEAR RADIOACTIVE HOT SPOTS IN THE ORWBG 13
FIGURE 8. MAP OF THE EXISTING NATIVE SOIL COVER AT THE ORWBG 14
FIGURE 9. RCRA/CERCLA LOGIC AND DOCUMENTATION 18
FIGURE 10. CONCEPTUAL SITE MODEL FOR HRB 21
FIGURE 11. CONCEPTUAL SITE MODEL FOR WARNER'S POND 22
FIGURE 12. CONCEPTUAL SITE MODEL FOR HP-52 PONDS 24
FIGURE 13. CONCEPTUAL SITE MODEL FOR THE ORWBG 25
FIGURE 14. SCHEMATIC ILLUSTRATION OF SELECTED REMEDY AT HRB 65
FIGURE 15. SCHEMATIC ILLUSTRATION OF SELECTED REMEDY AT
WARNER'S POND 66
FIGURE 16. SCHEMATIC ILLUSTRATION OF SELECTED REMEDY AT HP-52
PONDS 67
FIGURE 17. SCHEMATIC ILLUSTRATION OF SELECTED REMEDY AT
ORWBG 68
LIST OF TABLES
TABLE 1. KEY RCRA/CERCLA DOCUMENTS FOR THE GSACU 4
TABLE 2. SUMMARY OF COCs AT THE GSACU 28
TABLE 3. QUANTITIES OF CONTAMINATED MEDIA AT THE GSACU 29
TABLE 4. POTENTIAL ARARS FOR THE GSACU 37
TABLE 5a. RGs FOR PTSM COCs (BASED ON TOXICITY) 39
TABLE 5b. RGs FOR CMCOCs AND PTSM COCs (BASED ON MOBILITY) 39
TABLE 5c. RGs FOR HUMAN HEALTH/ECOLOGICAL COCs 39
TABLE 6. COMPARATIVE ANALYSIS OF ALTERNATIVES- HRB,
WARNER'S POND AND HP-52 PONDS 49
TABLE 7. COMPARATIVE ANALYSIS OF ALTERNATIVES - ORWBG 54
TABLE 8. IMPLEMENTATION SCHEDULE 77
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LIST OF ACRONYMS AND ABBREVIATIONS
AEA Atomic Energy Act
ARAR applicable or relevant and appropriate requirement
bis below land surface
BRA Baseline Risk Assessment
CAB Citizens' Advisory Board
CERCLA Comprehensive Environmental Response, Compensation and Liability Act
CERCLIS Comprehensive Environmental Response, Compensation and Liability
Information System
CFR Code of Federal Regulations
Ci curies
crn/sec centimeters per second
CMCOC contaminant migration constituent of concern
CMI/RAIP corrective measures implementation/remedial action implementation plan
CMS/FS corrective measures study/feasibility study
COBRA computerized burial record analysis
COC constituent of concern
COI constituent of interest
COPC constituent of potential concern
CSM conceptual site model
cy cubic yards
EIA Environmental Impact Assessment
ESD Explanation of Significant Difference
ETF Effluent Treatment Facility
FFA Federal Facility Agreement
ft feet
GSACU General Separations Area Consolidation Unit
HAGOU H-Area Groundwater Operable Unit
HIPSL H-Area Inactive Process Sewer Line
HQ hazard quotient
HRB H-Area Retention Basin (281-3H)
HS-Hg-1 mercury hot spot within ORWBG
HSWA Hazardous and Solid Waste Amendments
IOU integrator operable unit
IROD interim record of decision
LLC Limited Liability Company
LLRWDF Low Level Radioactive Waste Disposal Facility
LUC Land Use Controls
LUCAP Land Use Controls Assurance Plan
LUCIP Land Use Controls Implementation Plan
MCL maximum contaminant level
mg/kg milligrams per kilogram
MWMF Mixed Waste Management Facility
NBN no building number
NCP National Oil and Hazardous Substances Pollution Contingency Plan
ND not detected
NEPA National Environmental Policy Act
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LIST OF ACRONYMS AND ABBREVIATIONS (CONTINUED)
NPL Nati onal Pri oriti e s Li st
O&M operations and maintenance
ORWBG Old Radioactive Waste Burial Ground (643-E)
OSTs Old Solvent Tanks (650-0IE through 22B)
OU operable unit
pCi/g picoCuries per gram
pCi/L picoCuries per liter
PTSM principal threat source material
RAO Remedial Action Objective
RCRA Resource Conservation and Recovery Act
RFI RCRA Facility Investigation
RG remedial goal
RGO remedial goal option
RI Remedial Investigation
ROD Record of Decision
SARA Superfund Amendments Reauthorization Act
SB/PP Statement of Basis/Proposed Plan
SCDHEC South Carolina Department of Health and Environmental Control
SCHWMR South Carolina Hazardous Waste Management Regulations
SEA site evaluation area
SRS Savannah River Site
USDOE United States Department of Energy
USEPA United States Environmental Protection Agency
UTRA Upper Three Runs Aquifer
VOC volatile organic compound
WAC waste acceptance criteria
WIPP Waste Isolation Pilot Plant
WSRC Westinghouse Savannah River Company
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I. SAVANNAH RIVER SITE AND OPERABLE UNIT NAME,
LOCATION, AND DESCRIPTION
Unit Name, Location, and Brief Description
The General Separations Area Consolidation Unit (GSACU) includes the following waste units:
H-Area Retention Basin (281-3H) and Spill on 05/01/1956 of Unknown Amount of
Retention Basin Pipe Leak (NBN)
Warner's Pond (685-236) and Spill on 03/08/1978 of Unknown Seepage Basin Pipe Leak
in H-Area Seepage Basin (NBN) and Spill on 02/08/1978 of H-Area Process Sewer Line
Cave-In (NBN)
HP-52 Ponds
Old Radioactive Waste Burial Ground (ORWBG) (Including Solvent Tanks) (643-E)
Comprehensive Environmental Response, Compensation and Liability Information System
(CERCLIS) Identification Numbers: OU-22, OU-48, OU-49, and OU-32
Comprehensive Environmental Response, Compensation and Liability Act (CERCLA)
Identification Number: SCI 890 008 989
Savannah River Site
Aiken, South Carolina
United States Department of Energy
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
located approximately 25 miles southeast of Augusta, Georgia, and 20 miles south of Aiken,
South Carolina.
The United States Department of Energy (USDOE) owns SRS, which historically produced
tritium, plutonium, and other special nuclear materials for national defense and the space
program. Chemical and radioactive wastes are by-products of nuclear material production
processes, Hazardous substances, as defined by CERCLA, are currently present in the
environment at SRS.
The Federal Facility Agreement (FFA) (FFA 1993) for SRS lists the GSACU as a Resource
Conservation and Recovery Act (RCRA) Solid Waste Management Unit/CERCLA unit
requiring further evaluation. The GSACU required further evaluation through an investigation
process that integrates and combines the RCRA Facility Investigation (RFI) process with the
CERCLA Remedial Investigation (RI) process to determine the actual or potential impact to
human health and the environment of releases of hazardous substances, pollutants or
contaminants to the environment.
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.SAVANNAH RIVER S1TH
Figure 1. Location of the GSACU ai SRS
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II. SITE AND OPERABLE UNIT COMPLIANCE HISTORY
SRS Operational and Compliance History
The primary mission of SRS has been to produce tritium, plutonium, and other special nuclear
materials for United States defense programs. Production of nuclear materials for the defense
program was discontinued in 1988. SRS has provided nuclear materials for the space program, as
well as for medical, industrial, and research efforts up to the present, Chemical and radioactive
wastes are byproducts of nuclear material production processes. These wastes have been treated,
stored, and in some cases, disposed at SRS. Past disposal practices have resulted in soil and
groundwater contamination.
Hazardous waste materials handled at SRS are managed under RCRA, a comprehensive law
requiring responsible management of hazardous waste. Certain SRS activities require South
Carolina Department of Health and Environmental Control (SCDHEC) operating or post-closure
permits under RCRA. SRS received from SCDHEC a RCRA hazardous waste permit, which was
most recently renewed on September 5, 1995.
Module IV of the Hazardous and Solid Waste Amendments (HSWA) portion of the RCRA
permit mandates corrective action requirements for non-regulated solid waste management units
subject to RCRA 3004(u).
On December 21, 1989, SRS was included on the National Priorities List (NPL). 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, 42 U.S.C.A.
§9620, USDOE has negotiated a FFA (FFA 1993) with the United States Environmental
Protection Agency (USEPA) and SCDHEC to coordinate remedial activities at SRS into one
comprehensive strategy that fulfills these dual regulatory requirements, USDOE functions as the
lead agency for remedial activities at SRS, with concurrence by the USEPA - Region IV and the
SCDHEC.
Operable Unit Operational and Compliance History
The GSACU consists of four primary waste units: H-Area Retention Basin (HRB), Warner's
Pond, HP-52 Ponds, and the ORWBG including its 22 underground storage tanks known as the
OSTs. The Warner's Pond unit also includes a portion of the HIPSL. Collectively, these waste
units are identified as a single operable unit (OU) (Figure 1) because of their proximity to each
other and similar health and environmental threats.
The GSACU has been assessed through characterization and a series of documents written by
USDOE and approved by the regulatory agencies (SCDHEC and USEPA). These documents are
listed on Table 1, and reference citation information is provided in Section XVI, References.
Initially, the four waste units were being evaluated separately. The RCRA/CERCLA documents
for HRB and the ORWBG were completed through the Corrective Measures Study/Feasibility
Study (CMS/FS) stage, and it was determined that there was a preference to remove principal
threat source material (PTSM) from HRB and place it at the ORWBG. At this point, principal
threat source material (PTSM) was also identified at Warner's Pond and HP-52 Ponds during
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Table 1. Key RCRA/CERCLA Documents for the GSACU
HRB
Warner's
Pond
HP-52 Ponds
ORWBG
(including
OSTs)
Work Plan
WSRC 1997a
WSRC2001a
WSRC 1997b
WSRC 2000b
RFI/RI&
BRA
WSRC 1998
-
-
WSRC 1997c
WSRC 1997d
WSRC 1997e
CMS/FS
WSRC 2000a
-
~
WSRC 200 Ib
IROD
N/A
N/A
N/A
WSRC 1996
WSRC 2000c
SB/PP
WSRC 2002
Reference citation information is provided in Section XVI, References.
- Document not prepared. Units combined into singleOU due to similarity of health and environmental threats, contaminants ot
concern, and proximity.
N/A = not applicable
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precharacterization work. Given the similar health and environmental threats, similar geologic
setting, and proximity of the units; USDOE, SCDHEC, and USEPA agreed to consolidate HRB,
Warner's Pond, HP-52 Ponds, and the ORWBG into a single OU to expedite remedial action. As
a result, an RFI/RI/BRA and CMS/FS were not needed for Warner's Pond or HP-52 Ponds
(Table 1).
HRB
HRB (281-3H) is a single open inactive retention basin surrounded by a berm (Figures 2 and 3).
HRB is 200 ft long by 120 ft wide by 7 ft deep. From 1955 to 1972, it received non-hazardous
radioactively-contaminated wastewater from chemical separations facilities and from the H-Area
Tank Farm. Wastewater flowed from these facilities through an underground process sewer line
to a diversion box that directed the waste stream to either HRB (281-3H) or a former retention
basin (281-7H) located several hundred yards to the west at the location of the current
operational retention basin (281-8H). The diversion box is still operational and is currently used
to route wastewater to the operational retention basin 281-8H. The process sewer line from the
diversion box to HRB is no longer in service and is part of the HRB unit. This segment is a 3-ft
diameter concrete pipe 75 ft long. Drainage from HRB was via a 100-ft long, 3-ft diameter
concrete pipe on the south side of the basin. The pipe discharged to a concrete spillway along an
existing active effluent stream that flows from H Area to Fourmile Branch (Figure 3). The exact
volumes of wastewater received at the basin and discharged from the basin are not known. In
May 1956, an undetermined volume of material leaked, from the discharge gate on the south side
of HRB. SRS constructed a temporary holding pond (approximately 45 x 45 ft) to contain the
material. This area was identified as a site evaluation area (SEA) called Spill on 05/01/1956 of
Unknown Amount of Retention Basin Pipe Leak (NBN) (no building number) and subsequently
has been included in the HRB unit.
There is a soil pile on the western side of the basin. The soil pile is 160 ft long by 60 ft wide by
15 ft high. The soil is the excavated remains of a former basin (281-7H) (the location of the
operational 281-8H basin) which was adjacent to HRB. When the basin 281-SH was constructed
in 1972, contaminated soil from 281-7H was removed, placed on asphalt next to HRB, and
covered by asphalt.
Trees and other vegetation were removed from HRB in 1996. HRB is now primarily covered
with grasses and scattered small shrubs. Standing rainwater is normally present in HRB. The
amount varies seasonally, depending on the amount of rainfall and the evaporation rate.
Warner's Pond
Warner's Pond (Figures 2 and 4) is a 4-acre site centered on an area that was formerly occupied
by a 1-acre pond ("Former Pond" on Figure 4). The pond was constructed in 1956 as an
emergency holding pond to receive contaminated cooling water from the 221-H (H Canyon)
building that flowed into an effluent stream. Contaminated cooling water was discharged to
Warner's Pond on three occasions: 1956 (cooling coil leak), 1960 (source not determined), and
1965 (cooling coil leak which released approximately 300 curies [Ci] of activity). Contaminated
water from all three events entered the pond via the effluent stream leading from H Area and was
diverted or pumped to HRB or to the H-Area Seepage Basins. In 1966, Warner's Pond was
drained, backfilled with two feet of clean soil, and paved with asphalt.
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and Fonner Location of
Basin28l-7H
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Figure 2, Oblique Aerial Photograph uf HRB, Warner's Pond, and HP-52 Ponds
CTJ
O
T3
i>>
re o
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ON M ^
O fB ^
-oi
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SOIL PILE SUBUNIT
BOTTOM/SID EW ALLS SL.-VJN T
BASIN BERM SUBUNIT
SEWER JNE. INLET & OLfTLET
DISCHAR3E ASEA
Figure 3. Map of HUB
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There are several inactive pipelines that run through the Warner's Pond area and are part of the
unit. One is a RCRA-regulated pipeline known ss the H-Area Inactive Process Sewer Line
(HIPSL) ("RCRA Inactive Process Sewer Line" on Figure 4). The HIPSL is an. 18-inch-diameter
vitrified clay pipe through which liquid waste was transported from the Separations Facilities to
the H-Area Seepage Basins. The HIPSL is approximately 2 to 6 ft below land surface (bis) in the
former pond area and 4 to 10 ft bis on the north side of the railroad tracks. Facility records
indicate the sewer line operated from 1955 to 1982. This effluent was characteristically
hazardous due to mercury and chromium concentrations and low pH. No listed wastes were
managed at the HIPSL. There are approximately 1,250 ft of RCRA HIPSL, several manholes,
and a diversion box inside the Warner's Pond OU boundary.
Within the Warner's Pond waste unit, the HIPSL splits into two pipelines at the diversion box.
the main pipeline (the western branch) which discharged to the H-Area Seepage Basins, and an
overflow pipeline (the eastern branch) which discharged to an unnamed tributary of Fourmile
Branch. The eastern branch of the pipeline is identified as a part of the HIPSL because it is
downgradient of the other part of the HIPSL and potentially may have received RCRA
discharge.
The other two inactive pipelines in the Warner's Pond waste unit ("CERCLA Inactive Pipe" on
Figure 4) are within the berms and are regulated for remedial action in accordance with the SRS
FFA (CERCLA) as opposed to corrective action under the SRS RCRA Permit. One section is
approximately 350 ft of reinforced concrete pipe and the other section is approximately 230 ft of
polyethylene pipe. These pipelines were gravity-fed to the HIPSL and are near grade within the
berms. These pipelines adjoin the HIPSL from a network of sewer lines (now inactive) that
carried effluent to several non-RCRA regulated units (HRB [281-3H] and the former retention
basin 281-7H). This configuration provided the option to manage potentially
radiologically-contaminated effluent (non-RCRA contaminated cooling water from the chemical
separations process and occasional contaminated storm sewer drainage from the H-Area
Separations Tank Farm) that was sent to two basins (281-3H and 281-7H) or diverted to the
pipelines.
In 1978, two spills (overflows) from a diversion box along the then-active vitrified clay process
sewer line contaminated soils in the vicinity of the diversion box over an area at least 25 by 250
ft. This area was identified as a SEA called Spill on 03/08/1978 of Unknown Seepage Basin Pipe
Leak in H-Area Seepage Basin (NBN) and subsequently has been included in the Warner's Pond
unit.
There are also reports that 40 ft of the HIPSL collapsed in 1978 just north of the railroad Line at
the northern part Warner's Pond ("Pipeline Break" on Figure 4). This area was identified as a
SEA called Spill on 02/08/1978 of H-Area Process Sewer Line Cave-In (NBN) and subsequently
has been included in the Warner's Pond unit.
In 1978, radiological survey data and sampling data identified elevated beta-gamma activity at
Warner's Pond that warranted corrective measures. Soils exceeding 2,000 counts per minute
(approximately 1,000 cubic yards [cy]) were removed from the former pond area and sent to the
Burial Ground Complex for disposal. The area was then treated with herbicide, graded with fresh
soil, topped with a clay overburden, and re-paved with asphalt. The effluent stream that fed the
former pond has been re-directed around the contaminated area.
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RCKA Inaclive Process Sewer Line
Warner's Pond OU Boundary 100
/\/ Effluent Stream
/\/ Inactive Pipe at Warner's Pond (CERCLA)
H-Area Inactive Process Sewer Line {RCRAJ within Warner's Pond
RCRA Inactive Process Sewer Lines
,'• ... Active & Inactive Process Sewer Lines
/*\/ Fences
/• N / Roads
A/ Railroads
100 200 Feet
Figure 4. Map of Warner's Pond
Pink arrows Indicate flow direction in pipelines when the pipelines were active.
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Trees and other vegetation were removed from Warner's Pond in 1996. Warner's Pond is
primarily covered with asphalt that is in generally good condition with few cracks,
HP-52 Ponds
The HP-52 Ponds unit (Figures 2 and 5) is a 1.1-acre site centered on an area that was formerly
occupied by two small holding ponds ("Former Pond Area" in Figure 5). In 1967 during a
transfer of high level waste, some material spilled onto the ground and flowed into a nearby
storm sewer and reached the HP-52 outfall. Two small holding ponds referred to as the "HP-52
Cesium Ponds" or "HP-52 Ponds" were constructed to contain the contaminated water.
Contaminated soil from the spill containing approximately 1,200 Ci of radioactivity was
removed and shipped ta the ORWBG. The stream banks below the HP-52 outfall were paved
with asphalt to minimize contaminant migration from the soil to the stream.
A smaller spill occurred in 1969 when a waste transfer line ruptured and released high level
waste to the storm sewer and outfall. After the 1969 spill, soil containing 0.5 Ci of radioactivity
was disposed in the ORWBG, Following this event, the pond areas were filled with
contaminated soil excavated from the stream banks, and covered with clean backfill. Stream flow
was diverted from the original effluent ditch("Old Effluent Ditch" in Figure 5) and re-directed
around the former ponds area and the original effluent ditch was backfilled.
There is no historical evidence to document the exact locations of the former ponds at HP-52
Ponds. The former ponds area noted on Figure 5 was inferred from the field locations of, and
information associated with, two concrete waste site markers.
Several soil piles are present at HP-52 Ponds. 'The piles ere the result of movement of soil at the
unit to fill the pond areas, to backfill ditches, and to redirect the active regulated effluent ditch.
A pre-SRS historic drainage channel fed by stormwater runoff is present south of the former
ponds area ("Historic Drainage Channel" on Figure 5). Beaver dams created a pond ("Former
Beaver Pond" on Figure 5) along the historic drainage channel. During pre-characterization
sampling, sediments beneath the former beaver pond (Figure 5) were determined to be
radiologically contaminated due to the HP-52 spills. The beaver dams were removed and the
pond drained; as a result, the exposed materials are evaluated as soil.
Trees and other vegetation were removed from HP-S2 Ponds in 1996. The HP-52 Ponds unit is
now primarily covered with grasses and scattered small shrubs.
ORWBG
The ORWBG (Figures 6, 7, and 8) is part of the central disposal area for solid radioactive waste
at SRS known as the Burial Ground Complex. Waste was disposed at the ORWBG from 1952
until 1974, when the site was essentially filled and the majority of waste disposal operations
shifted to other facilities in the Burial Ground Complex.
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A-.
Existing Rffluent Ditch
Former of HP-52 Ponds Area
mmamm
Old Fffluent Dirch
Historic Drainage Channe
HP-52 OU
400 Feet
•
120 Meters
i •, .. Fences
f\J R«lln»d»
f\J Slreamc (arrow* ahow flow direction)
1996 Ditch
Original Ditch
1371
HP-52 Oulfall
Figure 5. Map of HP-52 Ponds
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HS-100-20
3
HS-1QO-8
HS-KKM
HS-XKM
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H6-W-6
HS-WO-B
5!
I I
HS-100-12
a
HS-WO-5
L-J
HS-100-10
HS-100-2
H8-1OT-7 -.
, •" .''
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• - 20 x 20 ft burial nrea containing greater ilian 60 curies of radioactivity
[_~_\ Radioactive Hot Spuls (100-ygar)
D Meram- Hot Spot (HS-Hg-1)
Figure 6. Map of OSTs, Mercurj' Hot Spot, and 100-Year Radioactive Hoi Spots in the ORWBG
in
70
O
»
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IN*
-------
, J , 4 | 5^ | 6^ | 7 ; * | 9 , ID | II , 12 ( T3 { 14 | 18 [ l« | 17 | 18 | ID | |
• = 20 x 20 jfl burial area containing greater than 60 curies of radioactivity
["! Radioactive Hot Spots (500-year)
= S O
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Figure 7. Map of 500-Year Radioactive Hot Spots in the OHVVBG
05
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Areas of burial trenches not yet covered by the native soil cover
Areas not included in the scope of this remedial action (operational area - will not be capped under this ROD)
in
Figure 8. Map of the Existing Native Soil Cover at the ORWBG
T3
IN*
§
IV ., Isi
30 i
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^1
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The ORWBG is a 76-acre disposal area for solid radioactive waste produced at SRS as well as
shipments from other USDOE and Department of Defense facilities. It accommodated disposal
of various levels and types of radioactive waste materials, including radioactively-contaminated
hazardous substances. These materials included low-level waste, intermediate-level waste, and
waste containing transuranic isotopes. Volumetrically, the majority of waste disposed at the
ORWBG was low-level incidental waste from laboratory and production operations, including
small equipment, spent air filters, clothes, analytical waste, decontamination residues, plastic
sheeting, gloves, soil, and construction debris.
During its operational history, approximately 7,125,000 ft3 of radioactive wastes including
radioactively-contaminated hazardous substances were buried at depth within the ORWBG.
Most wastes disposed in the ORWBG were placed in drums, cans, cardboard boxes, plastic bags,
and metal containers and buried in earthen trenches approximately 20 ft deep. Lesser amounts of
waste were buried in concrete culverts, casks, and stainless steel vessels. After approximately 16
ft of waste had been placed in the trenches, the trenches were returned to grade by backfilling
with approximately 4 ft of cover soil. Most waste was disposed of the ORWBG from 1952 until
1972. In addition, small quantities of radioactive waste (contaminated primarily with transuranic
isotopes) were disposed in 1973 and 1974. The ORWBG was also used to dispose of
contaminated equipment, to incinerate used solvent and bury the residue, and for sandblasting to
decontaminate equipment.
At the time of burial, approximately 5.1 million Ci of radioactivity was placed in the ORWBG.
Much of the short-lived radioactivity has decayed, but a large inventory of radioactive and
hazardous substances remain buried at depth in the ORWBG.
In 1996, USDOE issued an Interim Record of Decision (IROD) (WSRC 1996) to place a soil
cover on the ORWBG. The interim action installed a mounded 2- to 8-foot-thick low
permeability native soil layer with vegetative cover and an associated drainage network over
most of the ORWBG to minimize infiltration and leaching of the buried waste (Figure 8).
However, the native soil cover was not placed over the OSTs (which were empty at the time
except for residual contamination) because it could have hindered characterization or the final
remedial action and because the weight of the soil cover and the equipment used during its
placement could have damaged the tanks. Also, the native soil cover was not placed in the area
where Solid Waste Management Division has operating administrative buildings (between
interim covers B and D) nor in an area in the western part of the ORWBG between interim
covers A and B (Figure 8).
A second interim action was started in 2001 to stabilize the OSTs (WSRC 2000c). The OSTs,
including the residual materials in the tanks, are being grouted in place. The interim action is
scheduled to be completed in June 2003.
The ORWBG is covered by a vegetative cover of grass, which was established as part of the
1996 interim action.
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III. HIGHLIGHTS OF COMMUNITY PARTICIPATION
Both RCRA and CERCLA require the public to be given an opportunity to review and comment
on the draft permit modification and proposed remedial alternative. Public participation
requirements are listed in South Carolina Hazardous Waste Management Regulations
(SCHWMR) R.61-79.124 and Sections 113 and 117 of CERCLA, 42 U.S.C.A. $§ 9613 and
9617. These requirements include establishment of an Administrative Record File that
documents the investigation and selection of the remedial alternative for addressing the GSACU.
The Administrative Record File must be established at or near the facility at issue. The SRS
Public Involvement Plan (USDOE 1994) is designed to facilitate public involvement in the
decision-making process 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) of 1969. SCHWMR R.61-79.124 and Section 117(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 General
Separations Area Consolidation Unit (WSRC 2002), a part of the Administrative Record File,
highlights key aspects of the investigation and identifies the preferred action for addressing the
GSACU.
USDOE Order 451. IB (NEPA Compliance Program) directs that NEPA values (i.e., cumulative,
offsite, ecological, and socioeconomic impacts) should be integrated into USDOE CERCLA
documents to the extent practicable. An Environmental Impact Assessment (EIA) (USDOE
2002) for remediation of the GSACU was prepared for remediation of the GSACU in accordance
with SRS NEPA/CERCLA Integration Guidance (WSRC 1997T). The EIA was a part of the
CERCLA review of alternatives and is a reference in the CERCLA documentation for this
project.
The FFA Administrative Record File, which contains the information pertaining to the selection
of the remedial action, is available at the following locations:
US 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
The RCRA Administrative Record File for SCDHEC is available for review by the public at the
following locations:
The South Carolina Department of Health
and Environmental Control
Bureau of Land and Waste Management
8901 Farrow Road
Columbia, South Carolina 29203
(803) 896-4000
Lower Savannah District
Environmental Quality Control Office
206 Beaufort Street, Northeast
Aiken, South Carolina 29801
(803)641-7670
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The public was notified of the public comment period through mailings of the SRS
Environmental Bulletin, a newsletter sent to citizens in South Carolina and Georgia, and 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 Statement of Basis/Proposed Plan (SB/PP) 45-day public comment period began on June 6,
2002, and ended on July 20, 2002. A Responsiveness Summary, prepared to address comments
received during the public comment period, is provided in Appendix A of this Record of
Decision (ROD). It is also available with the final RCRA permit modification.
IV. SCOPE AND ROLE OF THE OPERABLE UNIT WITHIN THE
SITE STRATEGY
RCRA/CERCLA Programs at SRS
RCRA/CERCLA units (including the GSACU) at SRS are subject to a multi-stage RI process
that integrates the requirements of RCRA and CERCLA as outlined in the FFA (FFA 1993). The
RCRA/CERCLA processes are summarized below:
investigation and characterization of potentially impacted environmental media (such as
soil, groundwater, and surface water) comprising the waste site and surrounding areas
evaluation of risk to human health and the local ecological community
screening of possible remedial actions to identify the selected tecbnology which will
protect human health and the environment
implementation of the selected alternative
documentation that the remediation has been performed competently
evaluation of the effectiveness of the technology
The steps of this process are iterative in nature and include decision points that require
concurrence between USDOE as owner/manager, USEPA and SCDHEC as regulatory oversight
agencies, and the public (see Figure 9).
Operable Unit Remedial Strategy
The overall strategy for addressing the GSACU was to (1) investigate the ORWBG (including
the OSTs) to understand the nature and extent of the buried waste, (2) characterize FIRB,
Warner's Pond, and HP-52 Ponds by delineating the nature and extent of contamination and
identifying the media of concern; (3) evaluate media of concern and exposure pathways at FIRB,
Warner's Pond, and HP-S2 Ponds and characterize potential risks and identify constituents
warranting remediation; and (4) identify and perform a final action to remediate, as needed, the
identified constituents of concern (COCs).
-------
SRS RCRA/CERCLA UNIT
PRELIMINARY EVALUATION
* Unit Reconnaissance
• Unit Screen
RFI/RI WORK PLAN
Develop Conceptual Site Model (CSM)
Identify Data Needs
Develop Data Quality Objectives and Decision Logic
Develop Detailed Sampling and Analysis Plan
UNIT CHARACTERIZATION
Implement RFI/RI
Data Evaluation vs Data Quality Objectives
Re-Evaluate CSM
1
DATA EVALUATION
• Validation
• Verification
Tteatabiluy Studies
(as necessary)
RFI/RI REPORT
Establish Remedial Action
Objectives
CMS/FS REPORT
Identify Response Action
Identify Technologies
Alternatives Development
Alternatives Screening
Detailed Analysis
SB/PP
Preferred Alternative
Draft Permit Modification
Public Comment
RECORD OF DECISION
Select Remedy
Responsiveness Summary
Final Permit Modification
No Action Remedy
1
CORRECTIVE MEASURE/
REMEDIAL ACTION
• Unit Closure
• Post-Closure Documentation
(Post-Construction Report)
> if #
5? o
BASELINE RISK ASSESSMENT
• Determine Unit Risk
• Develop Remedial Goals and
Remedial Levels
o1
"I
P JH 3-
1 ^^ ^
i' o
Vl >•
ff O
POST-ROD
DOCUMENTATION
Remedial Design
Work Plan/Report
Remedial Action
Figure 9. RCRA/CERCLA Logic and Documentation
in
73
IN*
?8?k
i^l
-------
ROD for the GSACU (U) WSRC-RP-2002-4002
Savannah River Site Rev. 0
August 2002 Page 19 of 79
This ROD presents the final action for the GSACU, which is made up of HRB, Warner's Pond,
portions of the HIPSL in Warner's Pond, HP-52 Ponds, and the ORWBG (which includes the
OSTs). For HRB, the scope of the remedial action is to remediate the basin bottom/sidewalls, the
berm around the basin, the soil pile, the 75-ft section of process sewer line from the operational
diversion box to the basin, the 100-ft long discharge sewer line, and the discharge area including
a concrete spillway to the effluent stream. The area inside the boundary of HRB formerly
identified as a SEA (Spill on 05/01/1956 of Unknown Amount of Retention Basin Pipe Leak) is
part of HRB and is included in the remedial action. The diversion box is still operational and is
not included in the scope of the remediation. The existing effluent stream south of the unit to
which the basin discharged has been characterized in the vicinity of HRB. However, this stream
is not included in the scope of this remedial action because it is primarily contaminated by
upgradient sources in H Area unrelated to HRB. The effluent stream is being addressed
separately as part of the RCRA/CERCLA characterization of the upgradient facilities and the
IOU program. Although contaminated with radionuclides and inorganics, groundwater in the
aquifer under the unit (the UTRA) is not included in the scope of this remedial action because no
unit-related groundwater contaminants have been identified. Groundwater is not part of this unit;
it is being addressed separately under the H-Area Groundwater Operable Unit (HAGOU).
For Warner's Pond, the scope of the remedial action is to remediate the former pond area
(including the asphalt area and the berms), an 850-ft segment of the HIPSL including manholes
and the diversion box, and other inactive pipelines in the asphalt area and berms. The areas
within the boundary of the Warner's Pond area formerly identified as SEAs (Spill on 03/08/1978
of Unknown Seepage Basin Pipe Leak in H-Area Seepage Basin [NBN] and Spill on 02/08/1978
of H-Area Process Sewer Line Cave-In [NBN]) are part of the Warner's Pond unit and are
included with the remedial action. The effluent stream that has been diverted around the former
pond area is not included in the scope of this remedial action because the stream is primarily
contaminated by upgradient sources. The effluent stream is being addressed separately as part of
the RCRA/CERCLA characterization of the upgradient facilities and the IOU program. The
groundwater at Warner's Pond is contaminated with radionuclides and inorganics, although these
contaminants cannot be attributed with certainty to the waste unit. Groundwater in the UTRA is
not included in the scope of this remedial action. Groundwater is not part of this unit; it is being
addressed separately under the HAGOU.
For HP-52 Ponds, the scope of the remedial action is to remediate the two former pond areas, the
old effluent ditch, several soil piles at the unit that resulted from re-positioning and covering of
contaminated soils in the area, and contamination in the historic drainage channel near the
former beaver pond. The active regulated effluent stream that has been diverted around the
former pond area is not included in the scope of this remedial action because the stream is fed by
on-going H-Area facility operations with a potential for contamination. This active effluent
stream is being addressed separately as part of the RCRA/CERCLA characterization of the
upgradient facilities and the IOU program. Although contaminated with radionuclides and
inorganics, groundwater in the UTRA is not included in the scope of this remedial action
because the groundwater does not appear to have been affected by this unit, Groundwater is not
part of this unit; it is being addressed separately under the HAGOU,
For ORWBG, the scope of the remedial action is to address the waste buried at depth in the unit
and to implement a final action for the OSTs. The scope of the action excludes the areas between
interim covers B and D because these areas are actively supporting SRS's solid waste
-------
ROD for the GSACU (U) WSRC-RP-2002-4002
Savannah River Site Rev. 0
August 2002 Page 20 of 79
management operations including the "ship-to-WIPP" (Waste Isolation Pilot Plant) program.
There is no contaminated surface water at the ORWBG. Groundwater in the vicinity of the
ORWBG has been contaminated by releases from the various facilities in the Burial Ground
Complex, including the ORWBG (WSRC 1995, WSRC 1997d). The contaminated groundwater
is not included in the scope of this remedial action because it is being addressed by the corrective
action program in the SRS RCRA Part B permit for the Mixed Waste Management Facility
(MWMF) (WSRC 1995) in accordance with Settlement Agreement 87-52-SW.
A separate remedial action will be necessary for miscellaneous areas of the Burial Ground
Complex which are not included in the remedy for the GSACU. That separate action will address
the remaining areas of the Burial Ground Complex, specifically the operational Solid Waste
Management Division buildings (including underlying trenches) in the ORWBG (Figure 8) and
the non-hazardous waste portion of the Low Level Radioactive Waste Disposal Facility
(LLRWDF) (643-7E) (Figure 1) (including Combined Spills from ORWBG as reported in
WSRC-RP-97-419). That separate action, previous RCRA closures, and this GSACU ROD
represent a complete remedial strategy far the source units of the Burial Ground Complex.
The remedial action identified in this ROD for the GSACU will not affect the remedial actions of
other OUs at SRS.
lOUs are defined as surface water bodies (e.g., SRS streams, Savannah River) and associated
wetlands, including the water, sediment, and related biota. These surface water bodies are
referred to as "integrator" OUs because they represent the integration of potential contamination
discharged to surface water or migrating through groundwater from source OUs, SEAs, National
Pollutant Discharge Elimination System outfalls, and operational facilities to points of potential
receptor exposure. The GSACU is within the Fourmile Branch and Upper Three Runs
watersheds. Several source control and groundwater OUs within these watersheds will be
evaluated to determine effects, if any, to associated streams and wetlands. SRS will manage all
OUs to mitigate impact to the IOU. SRS's actions to address contamination at HRB, Warner's
Pond, and HP-52 Ponds serve to mitigate potential impacts to nearby streams. Upon disposition
of all OUs, a final comprehensive ROD for each IOU will be pursued with additional public
involvement.
V. OPERABLE UNIT CHARACTERISTICS
Conceptual Site Model
To better understand the risks posed to current and future receptors, a conceptual site model
(CSM) for each unit was developed. The CSMs illustrate the sources of contamination, potential
exposure pathways, and exposure media relevant to the unit. The CSMs are provided as Figures
10, 11, 12, and 13. Detailed discussions of the CSMs are available in the RFI/RI/BRA for HRB
(WSRC 1998), the RFI/RI Work Plan for Warner's Pond and HP-52 Ponds (WSRC 200la), and
the CMS/FS for the ORWBG (WSRC 2001b).
Media Assessment
The media assessment pertinent to this ROD includes the source units (e.g., contamination in
soil). Groundwater in the aquifer under HRB, Warner's Pond, HP-52 Ponds, and the ORWBG is
-------
Secondary
Primary Primary Release Seconrlury Release Exposure
Sources MecIionJsms Sourcts Mechanisms Media
Rjisin Boilfun ,-iiwi
-> Basin W&ier
Basin Water »
1 H VnlMiliauon"' j J Ambient A,r >
! 1 Near Basin
Basin Derm -* "»«•<*
t
f
^ Physical
I'criurhaiion
Infiltration,'
* Percolation
Sewer -ineand — ' . Process Sewer
Discharge Area Line/Outlet PtpeU&Ju
und Deterioration
Discharge lo Unnamed
— It Riyrtmle Branch
(Effluent Stream)
— ^ -Sl]rface Soits fc
1
1
M Vo I at iii zillion ^
Surfucc Soils
(0-t rtl ) *|
Ambient Air ^
(Vapors) n
Ambient Ait ^
(Psnico)aies) '
Exposure Routfi
Dcnustl Cunlacf
inlulaiion
Ingeslioo
External Kadiation
Inhalation
Prtcntwl Kc»i>tors
Hum.it
Cut-runt
On-tJnil
Worker
*
*
Vfcitor
Future
IndtKtrbl Hcrt&nt
Wwrktr (M
* *
* *
Erato
TcrrrctrUI
*
*
O
•isl
Aipnllc
*
*
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,
• *
0
*J Diota Uptake — , *\ Biola | >\ Inficaigti
Suhsurfacc Soils b - . fc
-P f 1 ft to Water Table) «
j i
£
i
•a
Perched
->| Vo.a.iliz.tion |— p,
l-'ycilive Dust
Generation
(Vapois) H
Ingest ion
External Radiation
inhalation
*
* *
* *
*
O
•
0
AmbieM Air .1 , v , .
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(P:iTtklllatM) 1
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1 — »j Dioiic Uptake j *\ Biola | H inficslion
' ' ^
* .
Wjlu ^ n 1^ n 10 ^ ^
Leaching
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l_ Surface Waier and
*
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Water Table Ground
Water"' ~*
1
Sediment
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Ambient Alf Near ^
— p
^ Biolic Uptake 1 — >
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Biota"' ~^
Inhalation
Ingesiion
Dermal Coniaci
Ingesiion
Dermal Contacl
I'.Tlemid RadiatiDCi
Inhalation
Ingesliost
Dermal Contact
i:xr.-rn,-i) Radiation
To be evaluated hy H Area Groundwstcr Operable Unit
To be evaluated the Fourmite Branch IOU
To be eva naied. by the Pourmilc Branch IOU
TP be cvalusied hy the Tourmite Branch IOU
Ingesiion
Volatile «*Blilueni3 hive nut been delected in i he suffice waier
Include* "f*i*v»1 and bortwnlal mipalkinoF coniaminanii within she wilcr table aquifci, Stinlli^Ui' (njuiid water can djtihajp* la effluent sircim.
~Bioia~i> C. f6
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c
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re IN>
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-------
PKIMAKY
SOURCE
H-A/ca
Effluen!
Stream
o
FR1MARY SECONDARY
RF.I.F.ASE SECONDARY RELEASE PATHWAYS
MECHANISM SOURCE MECHANISM MEDIA
EXPOSURE
ROUTE
ON- UNIT
WORKER
INDUSTRIAL
WORKER
' " Surfac
Dcposilion ~^ 0-0.'
— — T in t
j
— »• %
1
Os
Lie
Rel
L w •
J
•J3
7 Excavation/ Bioturbmtor
'£ \^. ^
: Soil
m
fl)'
1
1
=
F
rface
ill _» Soil
0-1.2 m
(0-4 ft*1
3 £
Deep Soil
>I.2m
<>4 ft)1
tiiU
case
Diversion
* Dilch
i H Volatilization | H Air Vapor H Inlatalion
— »
Fugitive Dusl
Generation
Diolic Uptake
*
9
ABUI.T
RESIDENT
CHILD
RESIDENT
TERRESTR1A1,
*
*
O
* fP-.riiruliir^ H W*d«*W *
9
*
*
O
AQUATIC
--
^| Biota | M Ingejcion -- — * * *
1 ».
r*
->
*
i — »
LF.OEND
Pathway*, current, historical, and future.
Principal pathways Tor tpiantifdive ;inalrsiK.
Pathways Tor qualitative analysis
Radiation
Emissions
Ingeslim
Dermal Cuniacl
~- — M Surface Soil 1 M ExKmal
| *"- " " j •- 1 Radiation
Volatilization M Air Vapor ^
Fugitive Dusl
Generation
Biodc Uptake
*
*
*
•
*
*
*
*
*
*
o
*
*
tatolayon
— W Air (Particulars) — H Iiniaiaiion
» Biota F*
Soii
Emissions
Jogestion
Dermal Cosiact
— >j Subsurface Soi [— ^
Leaching
J 1 ^
Seep
1 r
|->| Surface Water |— >•
J .
L>| Seilimcnl |— >•
1) Soils in QIC basin of the Warner's Pond
£££*
InhRlatiot
lo gey ton
Dermal Contact
'
..„
....
o
o
0
—
.._
*
•-
To be cvahtaied hy ihe H Area Gttsisdwaler Operable Unit
Pngestlon
Dermal Coniact
Bxlcrnol
Radiathm
Engeaicm
Dcrrm) ConlaCt
%££.
To be evaluated by !l* Fouttrtic Branch tOU
To be evaluated by ihe Fmsnalk Branch EOU
Tkb CSK HeiHtOtd |i«hw«?s for jvshimtton of nrleui rcccpftm In a
Ira0 »bon • "Mrdpin" tatw E«i IwfciMtcd tandif
gravelly d*f). Benim ihb *•<«• is I*t#r i*Mi*i; II b nut repc-owuta) on tl» CSH n * dfattftrt
> if
c »J
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Figure 11. Conceptual Site Model for Warner's Pond
-------
PRIMARY SECONDARY
RIMARY RiJI.KASE SKCONDARY RELEASE PATHWAYS
SOURCE MECHANISM SOURCE MKCHANISM _ MEUIA
Surface Soil
0-0.3 m
(0-1 f!)
1 i
i s
a o-
I 3
? e
1 i
Pipelines ^\ Leaks ^
Infilir
Subsurface
Soil
0-1.2 m
(0-4 ft)
mm/
Deep Soil
>1.2m
— »
*| Voatilizaiion | » Air Vapor _]
- Fugitive Dust
Generation
1 ^BioticUplokt
Radiation
* Emissions
A
(Panic
1\ Bu
if
ulates)
3ta
EXPOSURE
ROUTE
p\ Inhalalicui
k^i : ' ~ ~"
»1 ineanon
^j Surface Soil | »>|
^| Surface Soil | f-
1 ^| Volatilization J > Air Vapor
Fugitive Dust
Generation
J Biolic Uptake
^ Radiation
"" Emissions
Uermal CoalaCt
Exiemal Radiation
— ^j Air (Particnlntes) [ — f\ inhiininn
* Biota
— *j Subsurface Soil
Leachinc
-*1 Gtoun
.Seep
1
Surfac
i
dwaltsr
-»
Ingession
In^eseion
External RadiaLion
POTENTIAL KECErrORS
KNOWN
ON-UN1T
WORKER
•
*
•
—
r—
HVPOTHF-TfCAI.
INDUSTRIAL
WORKER
ADULT
RESIDENT
* I *
i 1
*
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-
~
CHILD
RESIDENT
*
• 1
•
_
ECOIXJGICAL
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o
O
= 1
1 °
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•
AQUATIC
._
....
._.
V
r
e Water
h*
Sediment | ^
LEOEHK
~* Pathway*, current, historical, and fiHure.
* Principal pathways lor quantitative analysis.
a Pathways lor qualitative analys s
Incomplele pathways
Jnhalaliwi
ingesUon
Uermal CMH»CI
j-iieesiim. '" —
Dcimal Contact
To 1» evaluated by the H Area Oroundwaier Operable \}»n
Tn be evaluated by the Fouimilc Branch 1OU
To be evaluated fey (he Founnjlc Branch IOU
This CSM htentiHed pilhvB}x tor criliuttan of T«rtrj In '
trKlKkniil RKtTRI/BRA. B«»«wl upnn f«fu!*tnry •p-wnicntfof PTSIV
rcnwwBl « this unN. mniunt iml trial will be ev*la*<«t In *
prctoniiruciton JocumciiL
PErcHnd water is praenl uiumallr in deqi sol) •!»« a "hdrdiwn" l«yer {Bfi Indurmtcd suKJy
CmwUT cUyV n
Figure 11. Conceptual Site Model for Warner's Pond (Continued)
-------
PRIMARY
SOURCE
PRIMARY
RELEASE
MECHANtSM
SECONDARY
SOURCE
SECONDARY
RELEASE
MECHANISM
Depostion/
Inhllrcn
Peicola
& Pathways. cuireiil. historical, and fulwre-
Q Principal pnlhways for quaniiLillve analysis.
Pathways Tor qualjlalive analysis.
Incomplete fialhways.
Subsurface Soil
Spills
0-1. 2 in
(0-4 ft)1
Inniinuloi
Percolalio
Deep Soil
>I.2m
04ft)1
Historic
Drainage
Sediments
-»
" . Radiation
" c • •
Emissions
• c/2 ys
<= ^ o
e o
»
§=^ rt-
•n ="
g? re
^ O
1) Soils in the basins of the HP-52 ponds.
» i
re i>>
n> o
N> g
!» ^
Figure 12. Conceptual Site Model for HP-52 Ponds
-------
PRIMARY
SOURCE
OST Contents
and Tunics
PRIMARY
RELEASE
MECHANISM
SECONDARY
SOURCE
Wasle in
ORWOO
Trenches
(Covered by
Native Soil
Cover)
Waste In
Mercury Hoi
Spot (Covered
by Native Soil
Cover)
Wasie in Kad
Hot Spots
(Covered hy
Native Soil
Cover!
»-
-*•
Deposition and
Drips/Spills
OST Leaks
OST Drips/Spills
Future Excavation or
Erosion'
Burial Ground Complex
~
Deep Soil in
ORWBG
>l,2m
(>4 ft) ...._.
Deep Soil in
Mercury Hot Spot
Deep Soil in Kad lira
Spots
Deep Sol! Under
OSTs
Surface and
Dioturbalipn of Covci
Material
(Loss of Institutional
Controls) Tulurc
Tank Collapse
• Fuiuic Tank Collapse
LEGEND
Pathways, current, historical and fuwrc
Principal pathways forquamitai ve evaluation
Pathways for qualitative evaluation
Incomplete pathways
Subsurface Soils
0 EO 1,2 m
(010 4 ft)
Wasie
SECONDARY
RELEASE
MECHANISM
Leaching
Slormwfltcr Runoff/
Erosion
PATHWAYS
MEDIA
Grtmndwaier In
Water Table
Aquifer
Seeps ^
Surface
Sed
Rmrrty
r
Waicr in
tmcnt
e Branch
Surface Water and
Snil in Drainage
Diiches
•) Volatilization | ^( Air (Vapor) | ^
l-ugitive Dust
(jcneration
W Air(Partiwlaics) ^
EXPOSURE
ROUTE
POTENTIAL RECEPTORS
KNOWN
On-Unit
Worker
HYPOTHETICAL
Industrial
Worker
Resident
ECOLOGICAL
Terrestrial
Aquatic
Inlialjiion
Ingcstiun
Dermal Conlact
To be addresser! by iti= corrective action proeram in Ihc SRS RCRA Pan D permi! for
the MWMP
Ineeslion
Dennal Conlacl
External Radiation
To be evaluated by the Founni £ Branch IOU
Ingest ion
Dermal Contact
External Radiation
Tnhafalion
Inhalation
o
o
o
O
O
O
o
o
O
O
O
O
O
o
o
o
—
—
—
o
o
O
o
--
....
•j Diolic Uptake
Direct Contact
—»
— ^
Biota | ^»| Ingesiion,
Subsur
__
ace and
face Soils
*
lnger>tion
Dermal Conlact
External Radiation
o
o
o
._
o
o
O
O
o
o
o
o
o
o
o
SoilWssic
Inhalation
Ingeslion
Dermal Conlacl
External Radiation
> C/5 M
I S O
£ i §
a- § 3*
N> » °
§«?
N> C. f6
03 >
ff O
Figure 13. Conceptual Site Model for the ORWBG
05
O
»
re
n
N>
(7. ^
o fe
-------
ROD for the GSACU (U) WSRC-RP-2002-4002
Savannah River Site Rev. 0
August 2002 Page 26 of 79
not included in the scope of this ROD. Groundwater in the aquifer under HRB, Warner's Pood,
and HP-52 Fonds is being addressed separately under the HAGOU. Groundwater in the aquifer
under the ORWBG is being addressed by the corrective action program in the SRS RCRA Part B
permit for the MWMF. The following paragraphs summarize the characterization of the HRB,
Warner's Pond, HP-52 Ponds, and ORWBG source units.
HRB
Various environmental investigations have been conducted at HRB since the early 1970s. The
RFI/RI field investigation was conducted in 1998 (WSRC 1997a, WSRC 1998). One-hundred
thirty-five soil samples and two surface water samples were collected. Samples were obtained
from the basin, the berm surrounding the basin, the process sewer line/discharge area, the soil
pile, and the effluent stream south of the basin.
Warner's Pond
Precharacterization environmental investigations were performed in 1997 and 1998 (WSRC
2001a). Samples were collected from the former pond area (9 soil samples from 3 locations, and
2 paired surface water and sediment samples) and from the soil surrounding the HIPSL (15
locations, 56 soil samples).
HP-52 Ponds
Precharacterization environmental investigations were performed in 1997 and 20GO (WSRC
200la). Samples were collected from the former ponds area (3 locations, 9 soil samples), the
existing effluent ditch (2 paired sediment and surface water samples), and from the historic
drainage charnel (5 paired surface water and sediment samples).
ORWBG
Traditional characterization (i.e,, intrusive sampling) was not performed at the ORWBG for the
reasons listed below:
There is an extensive amount of data available from past studies and historical burial
records.
• Intrusive sampling in the ORWBG would have posed unnecessary risks to the health and
safety of the workers because of direct contact with contaminated material.
• Intrusive sampling in the ORWBG would have disturbed the buried material and
potentially caused spreading of contaminated material.
• Because of the heterogeneous nature of the waste, sampling would not have accurately
characterized the nature and extent of contamination.
Characterization was accomplished through a detailed literature review; evaluation of aerial
photographs, construction drawings, health physics burial maps, and the computerized burial
record analysis (COBRA) database (a historical catalog of individual disposals); evaluation of
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ROD for the GSACU (U) WSRC-RP-2002-4002
Savannah River Site Rev. 0
August 2002 Page 27 of 79
past studies; review of process history; and interviews with SRS staff. This investigation is
documented in Source Term for the Old Radioactive Waste Burial Ground (ORWBG), Savannah
River Site (WSRC 1997c). Historical information was augmented by non-intrusive investigations
such as groundwater monitoring (WSRC 1997d), soil gas surveys, ambient air monitoring of
volatiles, monitoring of tritiated atmospheric vapor and standing surface water, and ground
penetrating radar surveys. A summary of the investigation techniques and results is provided in
Corrective Measures Study/Feasibility Study for the Old Radioactive Waste Burial Ground
643-E (WSRC 2001b). The data provided sufficient information to understand the hazards
associated with the ORWBG and to select a remedial alternative,
Media Assessment Results
Table 2 presents a summary of COCs for HRB, Warner's Pond, HP-52 Ponds, and the ORWBG.
Table 3 presents the total inventory of radionuclides and the volume of contaminated soil at each
unit.
HRB
The unit investigation determined that soils in the basin bottom/sidewalls, in the basin berm, in
the soil pile, and in the sewer line and discharge area are contaminated with radionuclides and
arsenic (Table 2). The highest levels of contamination at HRB are in the basin bottom/sidewalls.
Most of the contamination in the basin bottom is in the upper 1 ft of soil. In the basin sidewalls,
the contamination is primarily in the uppermost 2 ft of soil. In the basin berm, the contamination
is primarily in the upper 1 ft of soil. Along the process sewer line, the contamination is at and
below the pipe elevation. The discharge area has the deepest detected contamination. At the soil
pile, the contamination is limited to the soil pile itself and does not extend below the asphalt
layer beneath the soil pile. Available data suggest that the hardpan provides a natural limit to the
downward migration of contaminants at HRB, although this is not a certainty.
Warner's Pond
The investigations determined that soils in the former pond area, in the berms, along the HIPSL,
and at the diversion box are contaminated with radionuclides (Table 2). Additionally, some soils
in the former pond area are contaminated with mercury. The extent of contamination, including
any remnant left after excavation, will be refined during post-ROD field activities,
HP-52 Ponds
The investigations determined that soils and sediments in the former ponds area, the old effluent
ditch, the soil piles, and the historic drainage channel near the former beaver pond are
contaminated with radionuclides (Table 2). The extent of contamination, including any remnant
left after excavation, will be refined during post-ROD field activities.
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Table 2. Summary of COCs at the GSACU
COC Type of COC
ORWBG '
Cadmium COI
Lead COI
""""Mercury ~ COI
VOCs COI
Tritium COI
Cesrani-137 ~"~ ~ COI
Plutonium-238 COI
Plutonium-239 ! COI
Strontium-90 ! COI
Uranium-235 " 1 COI
Uranium-238 ! COI
Carbon- 14 j COI
Cobalt-60 i COI
~ f echnetium"-99 ~ " i COI
"Iodlne~-"l29 " j COI
"Neptuiiium-"237 " " j COI
HRB
Arsenic [ j
Americium-241 | ';
Cesiuro-i Jf ! FT SM (toxicity) !
CobatWQ ! T
Curium-243/244 | PTSM (toxicity) |
Europium- 154 j PTSM (toxicity) j
Plutonium-238 \ i
Plutonium-23 9/240 ! 1 CMCOC
Strontium-90 | PTSM (mobility) j CMCOC
Thorium-228 I j
Uranium-238 i F
Warner's Pond w
Mercury i ! CMCOC
Americium-241 | ! CMCOC
Cesium-137 | PTSM (toxicity)
Curium-243/244 I
Europium- 154 j
iodine-129 i CMCOC
Potassium-40 j CMCOC
Radium-226~ |
Radium-228 i
Strontium-90 1 CMCOC
HH
HH
*" Eco HH
., ___.
HH
*~ HH "
U . I Maximum I Maximum
nl S i Concentration i Background
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
mg/kg
,_Pci/g
pCi/g
pCi/g
pCi/g
pCi/g
Eco HH j pCi/g
HH 1 pCBg
HH ! pCi/g
-4 HH
HH
! HH
! HH
T "'HH -
i
i HH
\ HH
j HH "
HP-52 Ponds l
Cesium- 137 j PTSM (toxicity) [ j HH
Potassium-40 j j j HH
Radium-226 | ! HH
pCi/g
piCi/g
rag/kg
pCi/g
pC'i/i
pCi/g
pCi/g
pCi/g
pCi/g
PCi/g
pCi/g
pCi/g
PCi/g
pCi/g
pCi/g
1 3.2 ! 5.2
1 29
38,000
0.771
810
48. 1
1700
._ M-6
^ 9,000
9.33
40.4
'•52
75.8
422
42.4
6.45
1.33
5.98
2.87
17.3
131
415
1.92
1.14
2.04
0.55
ND
0.57
ND
ND
ND
ND
1_ ..^
1.18
0.061
2.04
0.55
0.57
ND
ND
4.07
1.83
53.5
ND
0.55
4.07
1,83
1 Constituents of interest (COIs) were defined on the basis of previous sampling, review of the burial records, process history, and
previous regulatory and historical documentation, rather than on the basis of quantitative risk assessments,
2 Constituents listed as contaminant migration constituents of concern (CMCOCs) for Warner's Pond are actually constituents of potential
concern (COPCs) which are based on conservative fete and transport calculations. They have not been subjected to detailed computer
modeling or an uncertainty analysis, and consequently, some of these constituents may not pose an actual teachability threat.
3 Constituents listed as human health COCs for Warner's Pond and HP-52 Ponds are actually COPCs which are based on preliminary
human health screening. They have not been subjected to detailed risk calculations or an uncertainty analysis, and consequently, some of
these constituents may not pose an actual exposure threat.
Eco = ecological COC
HH = human health COC
ND = not detected
N/A = not applicable
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Table 3. Quantities of Contaminated Media at the GSACU
Total Estimated
Inventory of
Radionuclides (Ci)'
Size of Unit (acres)
Estimated Volume of
Contaminated Soil
Requiring Remediation
(cy)
HRB
55
1.5
12,000
Warner's Pond
2
4
11,000
HP-52 Ponds
1
1.1
10,000
ORWBG
571,000
76
Volume of Waste =
264,000
The total estimated inventory of radionuclides is the current inventory. The inventories for HRB, Wanier's Pond, and HP-52 Ponds were
calculated based on the results of recent characterization sampling. The inventory for the ORWBG was calculated by determining the
amount of radioactivity originally disposed in the unit, and then accounting for radioactive decay of each isotope that has occurred since
disposal to Ihe present. For details of the methodology, please refer to Source Term for the Old Radioactive Waste Burial Ground
(ORWBG), Savannah River Site (WSRC 1997c). For information about when the waste was disposed and at what levels of radioactivity,
please refer to Section II.
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ORWBG
Areas of particular interest or "hot spots" within the ORWBG were identified in Delineation of
Potential "Hot Spots" for the Old Radioactive Waste Burial Ground (ORWBG) (WSRC 1997e).
These "hot spots" were identified based on the following criteria: high concentrations and/or
high levels of radioactivity, persistence of high radioactivity levels through time, burial type,
waste form, and mobility. Three general types of hot spots (discussed below) are identified: the
mercury hot spot, radioactive hot spots, and the OSTs (Figures 6 and 7).
Mercury Hot Spot (HS-Hg-I): HS-Hg-1 is an area containing approximately 20% of the total
mercury in the ORWBG (total inventory in the ORWBG is 28.6 cubic feet). HS-Hg-1 is located
in the southeastern part of the ORWBG (Figure 6). Each burial consisted of two or three
one-liter polyethylene bottles filled with elemental mercury, double-bagged and containerized in
5-gallon cans.
Radioactive Hot Spots: The radioactive hot spots are multiple and distinct areas containing
relatively high concentrations of radionuclides (i.e., greater than 60 Ci per 20 x 20 ft grid cell).
Generally these consist of tritium, transuranic isotopes, carbon-14, and fission products such as
cesium-137 and strontium-90. Because of natural radioactive decay, the radioactive composition
(and therefore the associated risk) decreases over time. Some areas of the ORWBG now
categorized as radioactive hot spots will not be as radioactive in the future. For example, hot
spots with tritium, which has a half-life of 12.3 years, will undergo decay such that in 100 years
they no longer fit the criteria as radioactive hot spots; essentially all tritium in the hot spots
disappears. Thus, the radioactive hot spots are subdivided according to their radioactivity at
varying time intervals in the future. Radioactive hot spots having greater than 60 Ci per grid cell
in 100 years since disposal activities essentially ceased (1974 + 100 years = 2074) are
categorized as 100-year hot spots (HS-100-1 through HS-100-21) (Figure 6). Radioactive hot
spots having greater than 60 Ci per grid cell in 300 and 500 years are categorized as 300-year
and 500-year hot spots, respectively. The geometries of the 300- and 500-year hot spots are the
same (HS-300/500-1 through HS-300/500-8) (Figure 7).
Old Solvent Tanks (OSTs): The ORWBG contains 22 underground storage tanks known as the
OSTs. From 1953 to 1977, the OSTs were used to store hundreds of thousands of gallons of
degraded solvent byproducts from the plutonium-uranium extraction (PUREX) process and
smaller amounts of tritiated pump oil, In 1977, the liquid was pumped out and transferred to
mother facility, but residual material that could not be pumped out (approximately 5,635 gallons
of liquids and 36.38 ft3 of solids) remained in the tanks.
Site-Specific Factors
There are no site-specific factors that may affect the remedial action at the GSACU. There are no
unique, special, or sensitive habitats. There are no areas of archaeological or historical
importance in the vicinity of the OU. The land in the area of the GSACU has been, and continues
to be, used extensively for SRS industrial activities.
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Contaminant Transport Analysis
At HRB, Warner's Pond, and HP-52 Ponds, a 10 to 15 ft thick indurated sandy gravelly clay is
present approximately 10 to 15 ft below the land surface. This layer, commonly referred to as the
"hardpan," is a natural barrier to downward vertical flow through the vadose zone. Rainwater
that infiltrates the soil collects on top of the hardpan, attesting to the low hydraulic conductivity
of the layer.
Contaminant fate and transport analyses were performed to determine if any constituents in soil
will leach through the vadose zone and result in groundwater concentrations above maximum
contaminant levels (MCLs) within 1,000 years. For HRB, the analyses included a comparison of
soil concentrations to soil screening levels and included computer modeling (SESOIL for metals
and RESRAD for radionuclides) (WSRC 1998). For Warner's Pond and HP-52 Ponds, the
analyses included a comparison of soil concentrations to soil screening levels using the
VZCOMML model (WSRC 200la).
For the ORWBG, contaminant transport was computed using a program named LVSTRAN
(Leaching Vadose Saturated Transport) to evaluate baseline conditions and to assess the effect of
different types of low permeability caps on reducing the teachability threat to groundwater
(WSRC 2001b).
The results of the analysis are provided in Section VII, Summary of OU Risks.
VI. CURRENT AND POTENTIAL FUTURE SITE AND RESOURCE
USES
Land Uses
The GSACU is located io the interior of the SRS, approximately 6 miles from the nearest SRS
boundary (Figure 1). SRS is a secured government facility with no residents. General public
access to SRS is prohibited by perimeter fences, guards, and security patrols. Access by SRS
workers to areas within the GSACU is controlled by physical and administrative controls.
Physical controls include fences and chain barriers. Administrative controls include SRS's Site
Use and Site Clearance Programs which restrict disturbance of the units and prevent drinking
water use of contaminated groundwater under the units.
The GSACU is within the industrially developed General Separations Area within the buffer
zone of an area designated for future heavy industrial and nuclear use. The large inventory of
unrecoverable radioactive wastes buried in the ORWBG, as well as the proximity of the GSACU
to nuclear materials processing facilities such as the H-Area Separations facilities and H-Area
Tank Farm, makes the GSACU unsuitable for residential use.
As outlined in the Savannah River Site Future Use Project Report (USDOE 1996), the USDOE
has taken steps to prohibit residential use of SRS, including land in the vicinity of the GSACU,
through its plan for current and future use of the SRS. Therefore, future residential use of the
area is not anticipated.
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The USDOE, USEPA, and SCDHEC agree that industrial land use restrictions are appropriate
for the GSACU. Industrial land use restrictions will include land use controls to ensure
protection against unrestricted (residential) uses. The future land use of the GSACU is
anticipated to be the same as the current land use (industrial use and control by the federal
government).
Groundwater Uses/Surface Water Uses
Groundwater at the GSACU is not currently being used for human consumption or any other
purpose. It is unlikely that drinking water wells wil 1 be installed in the future in the potentially
affected area (from the GSACU to the discharge areas along Fourmile Branch and Upper Three
Runs) because (1) residential use of the area is unlikely due to the proximity of the GSACU to
the heavy industrial zones of F and H Areas; and (2) water table wells in this area produce
insufficient water to be used as a source of drinking water.
Fourmile Branch and Upper Three Runs are the only sources of significant surface water near the
GSACU. Surface water in Fourmile Branch or Upper Three Runs is not used for irrigation,
consumption, or other uses.
USDOE controls drilling and surface water use through SRS's Site Use and Site Clearance
Programs; therefore, as long as USDOE maintains control of SRS, neither surface water nor
groundwater at the GSACU will be used as a potential drinking water
Future residential use of groundwater or surface water at the GSACU is not anticipated.
VII. SUMMARY OF OPERABLE UNIT RISKS
The risks to human health and the environment are normally determined in a Baseline Risk
Assessment (BRA) which identifies the COCs. A BRA was completed for HRB (see Section II)
and COCs were identified. Given the similar health and environmental threats, similar geologic
setting, and proximity of the units; USDOE, SCDHEC, and USEPA agreed that BRAs were not
needed for Warner's Pond or HP-52 Ponds. Constituents identified as human health COCs for
Warner's Pond and HP-52 Ponds are actually COPCs which are based on preliminary human
health screening of information from precharacterization environmental investigations. These
constituents have not been subjected to detailed risk calculations or an uncertainty analysis, and
consequently, some of these constituents may not pose an actual exposure threat.
Constituents listed as COCs for the ORWBG are actually constituents of interest (COIs). COIs
were defined on the basis of previous sampling, review of the burial records, process history, and
previous regulatory and historical documentation, rather than on the basis of quantitative risk
assessments. Table 2 presents a summary of COCs for HRB, Warner's Pond, HP-52 Ponds, and
the ORWBG.
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Risks at HRR
Human Health Risks at HRB
HRB poses unacceptable risks to current industrial workers, future industrial workers, and
hypothetical on-unit residents. Human health COCs include americium-241, arsenic, cesium-137,
cobalt-60, curium-243/244, europium-154, plutonium-238, plutonium-239/240, strontium-90,
thorium-228, and uranium-238. The total media risk for a future industrial worker exceeds the
acceptable target risk (less than 1 x 10"6 [one excess cancer in a million)) for the basin
bottom/sidewalls (4 x 10"1), basin berm (3 x 10"4), soil pile (1 x 10"2), and sewer line/discharge
area (2 x 10"4), PTSM based on toxicity (risk greater than 1 x 10"3) is present in the basin
bottom/si dewalls (due to elevated levels of cesium-137, curium-243/244, and europium-154) and
in the soil pile (due to elevated levels of cesium-137).
Ecological Risks at HRB
Ecological COCs are identified for the basin bottom/sidewalls. Cesium-137 and plutonium-238
pose ecological risks to terrestrial insectivorous mammals (represented by short-tailed shrews).
Hazard quotients (HQs) up to 15 for cesium-137 and 1.5 for plutonium-238 exceed the target HQ
of 1. For ecological receptors, an HQ greater than 1 is used to indicate constituent concentrations
exceeding acceptable risk levels.
Contaminant Migration Risks at HRB
Contaminant fate and transport analyses indicate that strontium-90 and plutonium-239/240 in the
basin are CMCOCs (constituents predicted to leach to the UTRA and exceed groundwater
standards within 1,000 years). Strontium-90 is predicted to exceed its MCL after 10 years, and
increase to 20,235 times its MCL at 75 years. Plutonium-239/240 is predicted to exceed its MCL
after 400 years, and increase to 700 times its MCL at 1,000 years. In addition, strontium-90 is a
PTSM COC based on mobility (predicted to exceed MCLs within 10 years) in the sewer
line/discharge area, It is predicted to leach to the UTRA and exceed its groundwater standard at
10 years, and increase to 948 times its MCL at 30 years.
Contamination in the basin is in contact with seasonal water that becomes trapped above the
hardpan layer. Although the hardpan provides a natural barrier to downward migration, the
contact between contaminated soil and water in the subsurface presents a teachability concern.
The inactive discharge pipeline and the associated trench in which the pipeline rests are potential
conduits for contaminant migration from the basin to the former discharge area. This presents a
contaminant migration risk for movement of contaminants out of the basin and into the effluent
stream on the south side of HRB.
If the asphalt cover over the soil pile were to deteriorate, future erosion of the soil pile would
present a contaminant migration risk, as contaminants may wash into HRB (basin 281-3H) and
potentially into the adjacent active retention basin (basin 281-8H).
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Risks at Warner's Pond
Human Health Risks at Warner's Pond
Warner's Pond poses unacceptable risks to current industrial workers, future industrial workers,
and hypothetical on-unit residents. Human health COCs for a future industrial worker include
cesium-137, curium-243/244, eoropium-154, potassium-40, radium-226, and radium-228. PTSM
based on toxicity is present in the former pond area due to elevated levels of cesium-137. Soils
along the HIPSL and at the diversion box, although determined non-hazardous, are contaminated
with radionuclides. In addition, vegetation may be drawing up radionuclides from the subsurface
and presenting an exposure risk. Surface water and sediment in the effluent stream are
contaminated with radionuclides from upgradient sources unrelated to the GSACU.
Ecological Risks at Warner's Pond
No ecological COCs are present at Warner's Pond.
Contaminant Migration Risks at Warner's Pond
Americium-241, iodine-129, potassium-40, strontium-90, and mercury are identified as
CMCOCs for the former pond area. They are predicted to leach through the vadose zone and
affect groundwater above MCLs within 1,000 years.
Contamination in the former pond area is in contact with seasonal water that becomes trapped
above the hardpan layer, The seasonal water is a result of impounded water behind berms that
were installed at the south end of the ponded area perpendicular to the original drainage path.
Although the hardpan provides a natural barrier to downward migration, the impounded water is
contaminated and presents a teachability concern.
Risks at HP-52 Ponds
Human Health Risks at MP-52 Ponds
HP-52 Ponds poses unacceptable risks to current industrial workers, future industrial workers,
and hypothetical on-unit residents. Human health COCs for a future industrial worker include
cesium-137, potassium-40, and radium-226, PTSM based on toxicity is present im the former
ponds area and in the old effluent ditch due to elevated levels of cesium-137. In addition,
vegetation may be drawing up radionuclides from the subsurface and presenting an exposure
risk.
Ecological Risks at HP-52 Ponds
No ecological COCs are present at HP-52 Ponds.
Contaminant Migration Risks at HP-52 Ponds
No contaminant migration COCs are present at HP-52 Ponds. However, contamination in the
former ponds area is in contact with seasonal water that becomes trapped above the hardpan
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layer. Although the hardpan provides a natural barrier to downward migration, the contact with
water in the subsurface presents a teachability concern.
Risks at ORWBG
Human Health and Ecological Risks for ORWBG
Typically, human health and ecological risk assessments for a source unit are performed on
surface soil (0 to 1 ft bis) and subsurface soil (0 to 4 ft bis). Deeper soils are generally not
assessed in the risk assessments because most excavation/construction activities and bioturbation
do not go deeper than 4 ft. Contamination below 4 ft bis is generally sufficiently isolated from
receptors.
At the ORWBG, surface and subsurface soils consist of backfill and the native soil cover
(uncontaminated soils from an SRS borrow pit). Under conventional risk assessment guidelines,
the level of risk posed by these soils is equivalent to the negligible ambient background risk
posed by natural soils. Furthermore, the original backfill material and the native soil cover shield
radiation that is being emitted from the waste at depth. Radiological surveys document that
radiation levels at the ground surface of the ORWBG are near background levels.
Although unit soils do not pose a risk to human health or the environment under conventional
risk assessment approaches, the presence of a large inventory of metals and long-lived
radionuclides at depth is a potential long-term threat. These wastes meet the definition of PTSM
based on toxicity.
COIs are constituents that the USDOE, USEPA, and SCDHEC have agreed are the primary
constituents of concern for the ORWBG and are the primary drivers in the remedy selection
process. COIs are mobile, hazardous, have a large inventory in the ORWBG, and/or have a long
half-life. COIs were defined on the basis of previous sampling, review of the COBRA database,
process history, and previous regulatory and historical documentation, COIs for the ORWBG
and OSTs include cadmium, lead, mercury, volatile organic compounds (VOCs), tritium,
cesium-137, plutonium-238, plutonium-239, strontium-90, uranium-235, uranium-238,
carbon-14, cobalt-60, technetium-99, iodine-129, and neptunium-237. The constituents
warranting remedial action at the ORWBG are termed COIs instead of COCs because the term
COCs implies that quantitative risk assessments have been done. At the ORWBG,
characterization and risk assessment were accomplished through detailed investigation of burial
records rather than through collection and analysis of samples. Because COCs were not
identified based on quantitative risk assessments in a conventional BRA, the constituents
warranting remedial action were given a different name (COIs).
The active institutional controls currently in place at the ORWBG (security fences, warning
signs, site inspections and maintenance, and land use restrictions) currently prevent exposure.
The unit will not pose an unacceptable exposure risk as long as institutional controls are
maintained because pathways to receptors at the surface are incomplete. The source unit would
only pose an unacceptable risk if institutional controls were lost in the future. If institutional
controls were lost, unauthorized use of the unit and degradation of the cover could occur,
resulting in exposure to waste by inadvertent intrusion by humans, bioturbation and
redistribution, or long-term erosion.
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Contaminant Migration Risks at the ORWBG
Contaminant fate and transport calculations (WSRC 200Ib) indicate that leaching which
occurred prior to emplacement of the native soil cover in 1997 has resulted in downward
migration of some of the more mobile constituents. Tritium, VOCs, iodine-329, technetium-99,
and uncontainerized carbon-14 are the most susceptible to leaching. These constituents are not
entirely mitigated by decay and may pose a current or short-term threat to groundwater. Tritium
and VOCs are currently present in the groundwater system directly beneath the unit at
concentrations above MCLs. Technetium-99 and iodine-129 are fission products, and some of
their inventory in the ORWBG would have been disposed of as uncontainerized job control
wastes susceptible to depletion by leaching. Other constituents having lower mobility (e.g.,
containerized carbon-14, cadmium, mercury, uranium-235, and uranium-238) may pose a
potential future threat to groundwater. Mercury has been detected in groundwater above the
MCL in one well, but the teachability threat of inorganics is expected to be low due to the
chemically-reducing environment of the trenches. The teachability threat posed by
plutonium-238, plutonium-239, cesium-137, strontium-90, cobalt-60, neptunium-237, and lead is
mitigated by low mobility and/or half-lives that are short relative to the time required for their
leaching and migration to groundwater. Lead has been sporadically detected in wells above the
MCL, but the detections are attributed to lead-containing parts in the pumps.
Conclusion of GSACU Risks
The risks at HRB, Warner's Pond, and HP-52 Ponds are similar in that (1) all three units contain
PTSM that presents an unacceptable human health risk to future industrial workers, and (2)
cesium-137 is the primary contaminant, both io terms of the principal risk driver and the extent
of contamination. Contamination at HRB, Warner's Pond, and HP-52 Ponds poses a threat to
current and future industrial workers who may come into contact with it, and HRB and Warner's
Pond represent continuing sources of potential groundwater contamination.
The ORWBG contains a very large inventory of short- and long-lived radioactive wastes and
other hazardous substances. These buried wastes are considered PTSM and would pose an acute
risk to human health and the environment if exposure were to occur. In addition, future leaching
of contaminants may further affect groundwater quality under the ORWBG.
Actual or threatened releases of hazardous substances, pollutants, or contaminants from the
GSACU, if not addressed by the selected remedy or one of the other active measures considered,
would present a current or potential threat to public health, welfare, or the environment.
VIII. REMEDIAL ACTION OBJECTIVES AND REMEDIAL
GOALS
Remedial goal options (RGOs) are concentration goals for individual chemicals for specific
medium and land use combinations. They are designed to provide conservative, long-term
targets for the selection and analysis of remedial alternatives. RGOs are selected to be protective
of both human health and the environment, as well as to comply with federal and state applicable
or relevant and appropriate requirements (ARARs). Table 4 presents ARARs. Human health
RGOs were based on the industrial worker scenario and ecological RGOs on a unit foraging
factor of 1 (Table 5c).
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Table 4. Potential ARARs for the GSACU
Media Affected
All Media
Air Quality
Drinking
Water Quality
Ground and
Surface Water
Quality
Radioactive
Materials and
Waste
Regulation or
Citation
NEPA
10CFR1021
Ambient Air Quality
40 CFR 50.6
SC R.61-62.5
Fugitive Dust
SCR.6 1-62.6
NESHAP
40 CFR 61. 92
Safe Drinking Water Act
SCR.61-58
SC R. 72-300 through
316
and
SC R.72-405 through
445
Clean Water Act/NPDES
SCR.61-9
10 CFR 61.40
and SCR.6 1-63
10 CFR 835
and
SCR.6 1-63
DOE Order 435.1
DOE Order 5400.5
Atomic Energy Act / 42
USC 201 Sections 2011-
2259
Synopsis of
Regulation or
Citation
Environmental impact
for federal projects
Standard for ambient
concentrations of 1 0
micron and smaller
particulates in air
Standard for ambient
concentrations of
fugitive particulates in
air
Standards for
radiological (100
mrem/yr) and other
hazardous pollutants in
ambient air
Standard establishes
drinking water MCLs
and MCLGs
Stormwater
Management and
Sediment Reduction
Stormwater and other
effluent discharge
permitting requirement
Disposal requirements
for radioactive wastes
and associated dose
limits
Occupational radiation
dose limits and
monitoring
requirements
Ensures that all
USDOE radioactive
waste is managed in a
manner that is
protective of worker
and public health and
safety, and the
environment.
Standards for exposure
to the public of
radiation from DOE
activities
Governs DOE use and
control of Special
Nuclear Materials and
their byproducts
Status
Action-specific
Action-specific
Action-specific
Action-specific
and
Chemical-specific
Chemical-specific
Action-specific
Action-specific
Action-specific
and
Chemical-specific
Chemical-specific
TBC
TBC
Chemical-specific
Pertinent Alternatives
HRB,
Warner's
Pond, HP-52
1,2,3,4,7
2, 3, 4, 7
2, 3, 4, 7
2,3,4,7
1,2,3,4,7
2,3,4,7
2, 3, 4, 7
4,7
1,2,3,4,7
1,2,3,4,7
1,2,3,4,7
1,2,3,4,7
ORWBG
1, 11, HI,
VI, VII
II, III, VI,
VII
11, III, VI,
Vll
II, 111, VI,
VII
I, II, III,
VI, VII
II, III, VI,
VII
II, III, VI,
VII
N/A
1, 11, HI,
VI, VII
I, II, III,
VI, VII
I, 11, III,
VI, VII
I, II, III,
VI, VII
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Table 4. Potential ARARs for the GSACU (Continued)
Media Affected
Hazardous
Waste
Solid Waste
Worker Safety
Transportation
Floodplains
Regulation or
Citation
RCRA, 40 CFR 262
and
SCR.6 1-79.262
RCRA, 40 CFR 268
and
SCR.61 -79.268
RCRA, 40 CFR 264
Subpart N (Landfills),
including 264.3 10
RCRA, 40 CFR 264.1! 5
SCR.61-107
OSHA 729 CFR 1910
OSH A/ 29 CFR 1926
DOE Order 5484
49 CFR 107
DOE Order 5480.3
DOE Order 460.1 A
40 CFR 6, Appendix A
10 CFR 1022
Synopsis of
Regulation or
Citation
Standards applicable to
generators of hazardous
wastes.
Land Disposal
Restrictions (LDRs) for
hazardous wastes
Basis for cap and
standards for closure
and post-closure care
Requirement for
independent registered
professional engineer
certification of RCRA
closures
Standards for
management and
disposal of
nonhazardous wastes
Safety standards for
general industry
Safety standards for
construction
Safety standards for
remediation workers
Transport regulations
for hazardous wastes
Requirements for
shipping hazardous
waste
Requirements for
shipping hazardous
substances
Standards for protection
offloodplains
Standards for protection
of floodpJains
Status
Chemical-specific
Chemical-specific
Chemical-specific
Action-specific
Chemical-specific
Action-specific
and
Chemical-specific
Action-specific
TBC
Action-specific
TBC
TBC
Location-specific
Location-specific
Pertinent Alternatives
HRB,
Warner's
Pond, HP-52
4,7
4,7*
N/A
2, 3, 4, 7
(HIPSL only)
4,7
2, 3, 4, 7
2, 3, 4, 7
2,3,4,7
4
4
4
2,3,4,7
2, 3, 4, 7
ORWBG
N/A
N/A
I, H, HI,
VI, VII
r N/A
N/A
11, III, VI,
VII
II, III, VI,
VII
11, HI, VI,
VII
N/A
N/A
N/A
N/A
N/A
* LDRs apply only to Warner's Pond HIPSL materials that are determined to be hazardous.
N/A = Not Applicable
TBC = to-be-considered
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Table 5a. RGs for PTSM COCs (Based on Toxicity)
PTSM COC
HRB
Cs-137
Warner's Pond
Cs-137
HP-52 Ponds
Cs-137
i Maximum
Concentration i
I (pCi/g) !
i 38,656 [
422 i
415 1
PTSM
RGO
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RGOs for each COC at HRB were calculated in the RFI/RI/BRA. Given the similarity io the
nature and scope of the problem at HRB, Warner's Pond, and HP-52 Ponds; the RGOs calculated
for HRB are also applicable for Warner's Pond and HP-52 Ponds.
Two constituents, cesium-137 and strontium-90, from the list of COCs can be used as indicator
contaminants for HRB, Warner's Pond, and HP-52 Ponds (i.e., contaminants that can be used to
guide the remediation and to assess when cleanup goals are met). Cesium-137 is the primary risk
driver in the human health and ecological risk assessments and is the contaminant responsible for
the designation of soils as PTSM based on toxicity. Strontium-90 is the primary contaminant
migration concern and is the contaminant responsible for the designation of soils as PTSM based
on mobility.
Collectively, these two constituents represent the majority of the contaminant inventory and risk.
Selection of these two constituents as the indicator constituents is further supported by the fact
that the extent of these two constituents encompasses the extent of the other COCs: remediation
of these two COCs will result in the remediation of the other COCs. RGOs for cesium-137 and
strontium-90 are identified on Table 5 (parts a, b, and c).
Remedial goals (RGs), the actual cleanup goals, are selected from the range of calculated RGOs.
For this unit, RGs are shown on Tables 5a, 5b, and 5c to correlate with the selected remedy at
HRB, Warner's Pond, and HP-52 Ponds. There is a preference to remove all PTSM and any
teachability (contaminant migration) threat. Table 5a presents the concentrations that would need
to be removed to eliminate PTSM based on toxicity. Table Sb presents the concentrations that
would need to be removed to eliminate the teachability threat (or, if removal to these levels is not
practicable, remediated by an infiltration control system to protect groundwater quality). If any
residual contamination remains that presents a human health or ecological exposure threat, Table
5c presents the concentrations that would need to be covered to prevent exposure above
risk-based levels.
Because of the conservative nature of the calculations in an RFI/RI/BRA, it is possible for a
calculated risk-based RGO to be less than ambient background levels. Since it is technically
impractical to remediate to less than background levels, the RGOs are compared to background
levels: if the calculated RGO is less than background levels, the RG defaults to the maximum
observed concentration in background samples. For cesium-137, the human health/ecological
RG defaulted to background.
There are no quantitative constituent-specific RGOs for the ORWBG. This is because the
ORWBG contains a large inventory of unrecoverable buried wastes (which are not feasible to
remove) and the surface of the unit does not pose an exposure risk. The cleanup goal for the
ORWBG is to meet the Remedial Action Objectives (RAOs) presented below.
RAOs describe what the cleanup will accomplish. RAOs provide the basis for evaluating the
remedial alternatives and identify how the unit risks will be addressed by the remedial action.
The following RAOs apply to HRB, Warner's Pond, and HP-52 Ponds:
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• Treat and/or remove PTSM (based on toxicity) by treating and/or removing cesium-137
at HRB, Warner's Pond, and HP-52 Ponds at levels above 104 pCi/g, to the extent
practicable.
• Treat and/or remove PTSM (based on mobility) by treating and/or removing strontium-90
at the HRB sewer line/discharge area at levels above 0.65 pCi/g, to the extent practicable.
• Control migration and leaching of strontium-90 that could result in groundwater
contamination in excess of MCLs beneath each unit by (1) removing soil above 1.5 pCi/g
at the HRB basin bottom/sidewalls, above 0.65pCi/g the HRB sewer line/discharge area,
and above 1.12 pCi/g at Warner's Pond, to the extent practicable; and (2) reducing
infiltration through any residual contamination above RGs.
Protect human and ecological receptors from surface materials containing cesium-137
above 0.55 pCi/g and strontium-90 above 57.2 pCi/g.
The RAOs for the ORWBG (applicable to the hot spots and the ORWBG as a whole) include the
following:
• Minimize the exposure risk to workers (current and future).
• Prevent or mitigate inadvertent human intrusion.
• Minimize ecological intrusion into the buried waste and redistribution/mobilization
(erosion) of contaminants from the waste unit to the surrounding areas.
Mitigate future leaching of contaminants to groundwater.
IX. DESCRIPTION OF ALTERNATIVES
Alternatives for HRB, Warner's Pond, and HP-52 Ponds
Seven remedial alternatives for HRB (Alternatives 1 through 7) were identified and evaluated in
a CMS/FS (WSRC 2000a). Alternatives 5 and 6 were similar to Alternatives 3 and 4, except they
included a provision for off-unit disposal of some wastes in the event that the volume of
contaminated media at the unit was too large to manage on-unit. A subsequent design study
determined that this provision was not necessary, and Alternatives 5 and 6 were dropped from
further consideration. Alternatives 1, 2, 3, 4, and 7 were retained for further consideration,
Given the similarity io the scope of the problem at HRB, Warner's Pond, and HP-52 Ponds, the
remedial alternatives developed for HRB are also applicable for Warner's Pond and HP-52
Ponds. The following alternatives for HRB, Warner's Pond, and HP-52 Ponds were retained for
further consideration:
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Alternative 1 — No Action
Total Present Worth Cost: HRB = $0.1 million, Warner's Pond = $0.1 million, HP-52 Ponds =
$0.1 million, Total = $0.3 million
Construction Time to Complete: 0 years
The No Action Alternative is required by the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP) in order to provide a baseline for comparison with other remedial
alternatives. It involves no activity to monitor, remove, treat, or otherwise mitigate the
contamination. The key ARARs for this alternative are the Atomic Energy Act (AEA) and
USDOE Order 5400.5. If this alternative were selected, the expected outcome would be the same
as current conditions: there would be unacceptable risks if exposure were to occur. The land
would not be available for industrial or residential land use.
Alternative 2 — Engineered Cap with Barrier Wall, and Institutional Controls
Total Present Worth Cost: HRB = $11.2 million, Warner's Pond = $10.1 million, HP-52 Ponds =
$9.6 million, Total = $30.9 million
Construction Time to Complete: 2-3 years
This alternative is a containment option. PTSM and soils containing CMCOCs would be
excavated to the extent practicable and re-positioned within the unit as needed (e.g., at HRB,
PTSM in the soil pile would be placed into the basin cavity). A low permeability engineered cap
would be installed over the waste, and a vertical grout barrier wall would be installed around the
perimeter of the waste unit to eliminate the lateral inflow of perched water and avoid contact of
contaminated media with groundwater. Institutional controls consisting of site maintenance (site
inspections, mowing, general housekeeping, repair of erosion damage, and other routine
maintenance as needed) and access controls (warning signs and land use restrictions) would be
implemented to prevent exposure to contamination left in place. The key ARARs for this
alternative are the AEA and USDOE Order 5400.5. If this alternative were selected, the expected
outcome would be that all PTSM would be contained, the units will not pose a teachability threat
to groundwater, and contamination in soil will be covered with clean soil so it would not pose an
exposure threat to receptors. The units would be available for future industrial land use with land
use restrictions to prevent excavation.
Alternative 3 -In Situ Solidification/Stabilization with Barrier Wall and Soil Cover, and
Institutional Controls
Total Present Worth Cost: HRB = $18.1 million, Warner's Pond = $16.4 million, HP-52 Ponds =
$15.6 million, Total = $50.1 million
Construction Time to Complete: 3-4 years
This alternative is a treatment option. PTSM and soils containing CMCOCs would be excavated
to the extent practicable and re-positioned within the unit as needed (e.g., at HRB, PTSM in the
soil pile would be placed into the basin cavity). The waste would then be grouted in
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place. A soil cover would be installed over the waste unit for additional shielding. A vertical
grout barrier wall would be installed around the perimeter of the waste unit to eliminate the
lateral in-flow of perched water and contact of contaminated media with groundwater.
Institutional controls consisting of site maintenance (site inspections, mowing, general
housekeeping, repair of erosion damage, and other routine maintenance as needed) and access
controls (warning signs and land use restrictions) would be implemented to prevent exposure to
contamination left in place. The key ARARs for this alternative are the AEA and USDOE Order
540G.5. If this alternative were selected, the expected outcome would be that all PTSM would be
treated, the units will not pose a teachability threat to groundwater, and contamination in soil
will be covered with clean sail so it would not pose an exposure threat to receptors.
The units would be available for future industrial land use with land use restrictions to prevent
excavation.
Alternative 4 -Excavation of Contaminated Soil for Off-SRS Disposal, and Institutional
Controls
Total Present Worth Cost: HRB = $19.1 million, Warner's Pond = $17.4 million, HP-52 Ponds =
$16.5 million, Total = $53.0 million
Construction Time to Complete: 3-4 years
This alternative is a removal option. PTSM and soils containing CMCOCs would be excavated
to the extent practicable, packaged, and shipped to an off-SRS disposal facility. After removal,
the excavation would be restored by backfilling to grade. A soil cover would be used to
minimize infiltration so that (1) no unit-related contaminants will cause MCL exceedances in the
UTRA beneath a unit, and (2) the accumulation of perched water atop the hardpan is minimized.
Institutional controls consisting of site maintenance (site inspections, mowing, general
housekeeping, repair of erosion damage, and other routine maintenance as needed) and access
controls (warning signs and land use restrictions) would be implemented to prevent exposure to
contamination left in place. The key ARARs for this alternative are the AEA and USDOE Order
5400.5. If this alternative were selected, the expected outcome would be that no PTSM will
remain, the units will not pose a teachability threat to groundwater, and any residual
contamination in soil that exceeds human health or ecological RGOs will be covered with clean
soil so it doesn't pose an exposure threat to receptors. The units would be available for future
industrial land use with land use restrictions to prevent excavation.
Alternative 7- Waste Consolidation at the ORWBG, and Institutional Controls
Total Present Worth Cost: HRB = $10.6 million, Warner's Pond = $9.6 million, HP-52 Ponds =
$9.1 million, Total = $29.3 million
Construction Time to Complete: 3-4 years 0
This alternative is a removal option. PTSM and soils containing CMCOCs at HRB, Warner's
Pond, and HP-52 Ponds would be excavated to the extent practicable and disposed at the
ORWBG. After removal, the excavation would be restored by backfilling to grade. A soil cover
would be used to minimize infiltration so that (1) no unit-related contaminants will cause MCL
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exceedances in the UTRA beneath a unit, and (2) the accumulation of perched water atop the
hardpan is minimized. Institutional controls consisting of site maintenance (site inspections,
mowing, general housekeeping, repair of erosion damage, and other routine maintenance as
needed) and access controls (warning signs and land use restrictions) would be implemented to
prevent exposure to contamination left in place. The key ARARs for this alternative are the AEA
and USDOE Order 5400,5. If this alternative were selected, the expected outcome would be that
no PTSM will remain at HRB, Warner's Pond or HP-52 Ponds; the units will not pose a
teachability threat to groundwater; and any residual contamination in soil that exceeds human
health or ecological RGOs will be covered with clean soil so it doesn't pose an exposure threat
to receptors. The units would be available for future industrial land use with land use restrictions
to prevent excavation.
Alternatives for ORWBG
Nine remedial alternatives for ORWBG (Alternatives ORWBG I through IX) were identified and
evaluated in a CMS/FS (WSRC 2001b). Alternatives ORWBG IV and V were similar to
ORWBG III, differing only in the options for the barrier (light rip-rap, heavy rip-rap, and
reinforced concrete slabs), and these options were subsequently incorporated into ORWBG III.
Alternatives ORWBG VIII and IX were similar to ORWBG VII in the same respect, and these
options were incorporated into ORWBG VII. Alternatives ORWBG IV, V, VIII, and IX were
unnecessary and were dropped from further consideration. Alternatives ORWBG I, II, III, VI,
and VII were retained for further consideration.
Each alternative consists of an action to the ORWBG as a whole, plus additional actions to hot
spots. Any action for the ORWBG as a whole would also be applied to HS-Hg-1, the radioactive
hot spots, and the OSTs,
The radioactive hot spots within the ORWBG were evaluated on a case-by-case basis. The three
actions under consideration specifically for the radioactive hot spots (No Further Action,
Intruder Barrier, and Removal) represent end members that could be combined to develop a
specific remedy. For example, a selected remedy could include no further action for some hot
spots, removal for others, and placement of an intruder barrier aver the remaining hot spots.
Institutional controls are a component of all alternatives (except a No Further Action base case
alternative) due to the large inventory of unretrievable waste in the ORWBG. Institutional
controls would include site maintenance (site inspections, mowing, general housekeeping, repair
of erosion damage, other routine maintenance as needed, and periodic maintenance of the
infiltration control system) and access controls (security fences, warning signs, and land use
restrictions), Unauthorized access and excavation would be prohibited, and the unit would
remain undisturbed. Institutional controls for the ORWBG, OSTs, and surrounding areas are
anticipated to be maintained in perpetuity.
Many of the remedial alternatives developed in the CMS/FS may logically be implemented over
an extended period of time. For example, the need for an intruder barrier may arise only in the
absence of institutional controls. Therefore, for all the alternatives, it is implicit that installation
of some long-term features is not necessary in the short-term to meet RAOs and could potentially
be deferred or implemented in phases.
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The alternatives for ORWBG include the following:
ORWBGI - No Further Action
Total Present Worth Cost: $<0.1 million
Construction Time to Complete: 0 years 0
The No Further Action alternative is required by the NCP to serve as a baseline for comparison
with other remedial alternatives. Under this alternative, no additional remedial activities at any
area of the ORWBG would be performed. Current maintenance measures would be terminated.
The existing low permeability native soil cover would be allowed to degrade. Institutional
controls would not be implemented. The key ARARs for this alternative are the AEA and
USDOE Order 5400.5. If this alternative were selected, the expected outcome would be the same
as current conditions: exposure to waste and unacceptable exposure could occur if erosion and
intrusion are not mitigated. Continued leaching of some constituents would increase as
degradation of the cover occurs. The land would not be available for industrial or residential land
use.
ORWBG II - Institutional Controls with Completion of the Native Soil Cover
Total Present Worth Cost: $2.0 million
Construction Time to Complete: 1 year
This alternative would involve institutional controls and completion of the low permeability
native soil cover over the ORWBG. The low permeability native soil cover that was placed
during the 1997 interim action would be expanded to cover inactive parts of the ORWBG that
have not yet been covered (i.e., over the OSTs and between interim covers A and B).
Institutional controls, including maintenance of the native soil cover and land use controls,
would be implemented. This alternative includes an option to stabilize HS-Hg-1 using grout or
chemical fixation agents to reduce the mobility of mercury. The remedy for a particular
radioactive hot spot could be the same as that for the ORWBG as a whole, placement of an
intruder barrier, or removal/disposal. The key ARARs for this alternative are the standards for
closure and post-closure care specified in RCRA. If this alternative were selected, the expected
outcome would be that the ORWBG would not pose a surface exposure risk te industrial workers
or ecological receptors, and the teachability threat posed by waste at depth in the ORWBG
would be mitigated by the native soil cover (although there is uncertainty whether a soil cover
would provide adequate protection against future leaching to groundwater). The unit would be
available for industrial land use with restrictions to prevent excavation.
ORWBG III - Institutional Controls with Completion of the Native Soil Cover and Addition of
a Light Rip-Rap Barrier
Total Present Worth Cost: $12.4 million
Construction Time to Complete: 1-2 years
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This alternative would involve institutional controls and a low permeability native soil cover
with near-term placement of a light rip-rap barrier over the ORWBG. The low permeability
native soil cover that was placed during the 1997 interim action would be expanded to cover
inactive parts of the ORWBG that have not yet been covered (i.e., over the OSTs and between
interim covers A and B). A light rip-rap barrier would be installed over the ORWBG to slow
degradation of the cover and to provide some degree of deterrence against inadvertent intrusion
in the event land use restrictions were to become ineffective. This alternative includes an option
to stabilize HS-Hg-1 using grout or chemical fixation agents to reduce the mobility of mercury.
The remedy for a particular radioactive hot spot could be the same as that for the ORWBG as a
whole, placement of an intruder barrier, or removal/disposal. Institutional controls, including
maintenance of the native soil cover and land use controls, would be implemented. The key
ARARs for this alternative are the standards for closure and post-closure care specified in
RCRA. If this alternative were selected, the expected outcome would be that the ORWBG would
not pose a surface exposure risk to industrial workers or ecological receptors and the teachability
threat posed by waste at depth in the ORWBG would be mitigated by the native soil cover
(although there is uncertainty whether a soil cover would provide adequate protection against
future leaching to groundwater). The unit would be available for industrial land use with
restrictions to prevent excavation.
ORWBG VI - Institutional Controls with Low Permeability Cap
Total Present Worth Cost: $12.0 million
Construction Time to Complete: 2-3 years
This alternative would involve institutional controls with the addition of a low permeability cap.
The low permeability native soil cover that was placed during the 1997 interim action would be
expanded to cover inactive parts of the ORWBG that have not yet been covered (i.e., over the
OSTs and between interim covers A and B). The low permeability native soil cover would then
become the foundation for a low permeability cap that would be placed over the ORWBG. The
cap would be a geosynthetic cover system meeting a performance standard for hydraulic
conductivity of <1 x 10"7 cm/sec. This alternative includes an option to stabilize HS-Hg-1 using
grout or chemical fixation agents to reduce the mobility of mercury. The remedy for a particular
radioactive hot spot could be the same as that for the ORWBG as a whole, placement of an
intruder barrier, or removal/disposal. Institutional controls, including maintenance of the cap and
land use controls, would be implemented. The key ARARs for this alternative are the standards
for closure and post-closure care specified in RCRA. If this alternative were selected, the
expected outcome would be that the ORWBG would not pose a surface exposure risk to
industrial workers or ecological receptors, and the teachability threat posed by waste at depth in
the ORWBG will be mitigated by the low permeability cap. The unit would be available for
industrial land use with restrictions to prevent excavation.
ORWBG VII - Institutional Controls with a Low Permeability Cap and a Light Rip-Rap
Barrier
Total Present Worth Cost: $22.5 million
Construction Time to Complete: 3-4 years
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This alternative involves institutional controls and a low permeability native soil cover with a
low permeability cap and near-term placement of a light rip-rap barrier over the ORWBG. The
low permeability native soil cover that was placed during the 1997 interim action would be
expanded to cover inactive parts of the ORWBG that have not yet been covered (i.e., over the
OSTs and between interim covers A and B). The low permeability native soil cover would then
become the foundation for a low permeability cap. The cap would be a geosynthetic cover
system meeting a performance standard for hydraulic conductivity of <1 x 10"7 cm/sec. A light
rip-rap barrier would be installed over the ORWBG as a layer of the cap to slow degradation of
the cap and to provide some degree of deterrence against inadvertent intrusion in the event land
use restrictions were to become ineffective. This alternative includes an option to stabilize
HS-Hg-1 using grout or chemical fixation agents to reduce the mobility of mercury. The remedy
for a particular radioactive hot spot could be the same as that for the ORWBG as a whole,
placement of an intruder barrier, or removal/disposal. Institutional controls, including
maintenance of the cap and land use controls, would be implemented. The key ARARs for this
alternative are the standards for closure and post-closure care specified in RCRA. If this
alternative were selected, the expected outcome would be that the ORWBG would not pose a
surface exposure risk to industrial workers or ecological receptors, and the teachability threat
posed by waste at depth in the ORWBG will be mitigated by the low permeability cap. The unit
would be available for industrial land use with restrictions to prevent excavation.
X. COMPARATIVE ANALYSIS OF ALTERNATIVES
Description of the Nine Evaluation Criteria
Each of the remedial alternatives is evaluated against the nine criteria established by the NCP, 40
Code of Federal Regulations (CFR) 300. The criteria are derived from the statutory requirements
of CERCLA Section 121. The criteria provide the basis for evaluating the alternatives and
selecting a remedy. The nine criteria are:
Threshold criteria:
1. Overall protection of human health and the environment
2. Compliance with ARARs 0
Balancing criteria:
3. Long-term effectiveness and permanence
4. Reduction of toxicity, mobility, or volume through treatment
5. Short-term effectiveness
6. Implementability
7. Cost
Modifying criteria:
8. State acceptance
9. Community acceptance
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Comparative Analysis for HRB, Warner's Pond, and HP-52 Ponds
Table 6 presents a summary of the evaluation of the alternatives against the comparative analysis
criteria. The evaluation is also briefly summarized below.
Overall Protection of Human Health and the Environment
Alternatives 2, 3, 4, and 7 would be protective of human health and the environment. PTSM and
soils containing CMCOCs would either be contained (capping), treated (grouting), or removed to
the extent practicable. Each alternative includes mechanisms to (1) provide shielding to reduce
radiation exposure to within acceptable limits, (2) protect groundwater quality, and (3) prevent
human access to contaminated media. Alternatives 4 and 7 provide a greater level of overall
protection because the contamination would be removed from the waste units (to the extent
practicable) rather than managed in place.
Alternative 1 (No Action) would not be protective of human health and the environment. The
resulting conditions would be the same as current conditions, which pose unacceptable risks to
current and future industrial workers.
Compliance with ARARs
All alternatives (except the No Action alternative) would comply with the ARARs identified in
Table 4. No Action would not comply with the AEA or USDOE Order 5400.5 because
radioactive contamination would be left unprotected and unmonitored. The AEA states that
"source, byproduct, and special nuclear materials must be regulated...to protect the health and
safety of the public." The AEA precludes USDOE from transferring property containing
radioactive substances to non-federal ownership,
Long-Term Effectiveness and Permanence
All alternatives except the No Action alternative effectively eliminate exposure pathways so that
there would be no unacceptable risk to a future industrial worker.
Alternative 2, 3, 4, and 7 will result in generally similar levels of residual risk in that no
exposure pathways will remain, Alternatives 4 and 7 would eliminate most risk through transfer
to another facility, and clean backfill would prevent exposure to residual risk at depth.
Alternative 3 would lock up contamination and make it unavailable for exposure,
Alternative 2 would isolate contamination under the engineered cap. The presence of streams
near HRB, Warner's Pond, and HP-52 Ponds presents some residual risk concerns in the
long-term because the streams could be potential mechanisms for erosion and redistribution of
contaminants and may be a future point of exposure. Alternatives 4 and 7 reduce this long-term
residual risk better than Alternatives 2 and 3 because contaminants would be removed from the
units rather than managed in place.
Although the residual risk for each alternative is generally similar, the alternatives have different
degrees of permanence. Alternatives 4 and 7 remove (to the extent practicable) PTSM and soil
containing CMCOCs from the unit, thereby providing a greater level of permanence than the
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Table 6. Comparative Analysis of Alternatives - HRB, Warner's Pond, and HP-52 Ponds
EVALUATION CRITERIA
Alternative 1
No Action
Alternative 2
Engineered Cap with
Barrier Wall
Alternative 3
In Situ Solidification/
Stabilization with Barrier Wall
and Soil Cover
Alternative 4
Excavation of
Contaminated Soil for
Off-SRS Disposal
Alternative 7
Waste Consolidation
at the ORWBG
Overall Protection of Human Health and the Environment
Human Health
Environment
Not Protective
Not Protective
Protective
Moderately protective
Protective
Moderately protective
Protective
Protective
Protective
Protective
Compliance with ARARs
Chemical-, Location-, and
Action-Specific
Does not comply with
AEA or DOE Order
5400.5
Complies
Complies
Complies
Complies
Long-Term Effectiveness and Permanence
Magnitude of Residual Risks
Permanence
High, particularly in
the absence of
institutional controls.
Not Applicable. There
are no remedy
components.
Moderate. Contamination
would be isolated from
exposure by backfill/soil
cover.
Some long-term concerns
associated with leaving
contamination in place near
streams.
Moderate. Cap and barrier
wall will provide exposure
barrier only as long as
integrity is maintained.
Existing and additional
institutional controls needed
for permanence.
Moderate. Contamination would
be locked up in grout.
Some long-term concerns
associated with leaving
contamination in place near
streams.
Moderate. Cover and grout with
barrier wall will provide exposure
barriers. Existing and additional
institutional controls needed for
permanence.
Low. PTSM and CMCOCs
removed to extent
practicable and relocated to
3 facility designed to
accept radioactive waste.
Residual contamination
would be isolated from
exposure by backfill/soil
cover.
High. Minimal institutional
controls required. All
contaminant pathways
would be permanently
eliminated.
Low. PTSM and
CMCOCs removed to
extent practicable and
relocated to a facility
designed to accept
radioactive waste.
Residual
contamination would
be isolated from
exposure by
backfill/soil cover.
High. Minimal
institutional controls
required. All
contaminant pathways
would be permanently
eliminated.
Reduction of Toxicity, Mobility, or Volume through Treatment
Degree of Expected Reduction in
Toxicity
Degree of Expected Reduction in
Mobility
No reduction other
than natural
radioactive decay.
None
No reduction other than
natural radioactive decay.
No treatment, but capping
would reduce contaminant
mobility through
containment.
No reduction other than natural
radioactive decay, but
bioavailability reduced.
Solidification would permanently
reduce contaminant mobility by
limiting leaching through the
waste.
Toxicity transferred to
receiving facility.
Mobility transferred to
receiving facility.
Toxicity transferred to
receiving facility.
Mobility transferred to
receiving facility.
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Table 6. Comparative Analysis of Alternatives - HRB, Warner's Pond, and HP-52 Ponds (Continued)
EVALUATION CRITERIA
Degree of Expected Reduction in
Volume
Alternative 1
No Action
None
Alternative 2
Engineered Cap with
Barrier Wail
Negligible change.
Alternative 3
In Situ Solidification/
Stabilization with Barrier Well
and Soil Cover
Negligible increase. Volume of
contaminated media would
increase as grout becomes
contaminated.
Alternative 4
Excavation of
Contaminated Soil for
Off-SRS Disposal
Volume reduced by
transfer to receiving
facility. Overall volume of
waste would increase as
materials and equipment
become contaminated
during removal, handling,
and disposal.
Alternative 7
Waste Consolidation
at the ORWBG
Volume reduced by
transfer to receiving
facility. Overall
volume of waste
would increase as
materials and
equipment become
contaminated during
removal, handling, and
disposal.
Short-Term Effectiveness
Risk to Remedial Workers
Risk to Community
Time Until Protection is
Achieved
None
None
N/A
Minimal
None
2-3 years after remedial
action (RA) start
Medium; minimal handling of
contaminated soils. However,
longer hours are required for
grouting.
None
3-4 years after RA start
Medium. Risks are
associated with excavation
and transportation.
Medium to high.
Transport off-SRS on
public righls-of-way.
3-4 years after RA start
Medium. Risks are
associated with
excavation and
transportation.
None
3-4 years after RA
start
Implcmcntahiliry
Technical Feasibility
Administrative Feasibility
Availability of Materials,
Equipment, Contractors
Readily implementable
No administrative
constraints
None required
Readily implementable but
would require more effort
than No Action.
No administrative
constraints
Readily available.
Readily implementable but would
require more effort than capping.
Future remedial actions, if
warranted, would be difficult.
No administrative constraints
Readily available.
Implementable. Must meet
DOT shipping and disposal
facility WAC. Potential
future need for treatment at
disposal site.
Possible public concern
with off-SRS
transportation.
Readily available.
Imptementable. Must
meet DOT shipping
and disposal Burial
Ground WAC.
No administrative
constraints
Readily available.
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Table 6. Comparative Analysis of Alternatives - HRB, Warner's Pond, and HP-52 Ponds (Continued)
EVALUATION CRITERIA
Cost (present value, in millions)
HRB
Warner's
Pond
HP-52
Total
Capital Cost
O&M Cost
Total Cost
Capital Cost
O&M Cost
Total Cost
Capital Cost
O&M Cost
Total Cost
Capital Cost
O&M Cost
Total Cost
Alternative 1
No Action
so.o
$0.1
$0.1
$0.0
$0.1
$0.1
$0.0
$0.1
$0.1
$0.0
$0.3
$0,3
Alternative 2
Engineered Cap with
Barrier Wall
$6.2
$5.0
$11.2
$5.6
$4.5
$10.1
$5.3
$4.3
$9.6
$17.1
$13.8
$30.9
Alternative 3
In Situ Solidification/
Stabilization with Barrier Wall
and Soil Cover
Alternative 4
Excavation of
Contaminated Soil for
Off-SRS Disposal
$13.1
$5.0
$18.1
$11.9
$4.5
$16.4
$11.3
$4.3
$15.6
$36.3
$13.8
$50.1
$18.1
$1.0
$19.1
$16.5
$0.9
$17.4
$15.7
$0.8
$16.5
$50.3
$2.7
$53.0
Alternative 7
Waste Consolidation
at the ORWBG
$9.6
$1.0
$10.6
$8.7
$0.9
$9.6
$8.3
$0.8
$9.1
$26.6
$2.7
$29.3
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other alternatives. Alternative 3 is more permanent than Alternative 2 because an engineered cap
(Alternative 2) is subject to erosion and would require more long-term maintenance, Alternative
1 is the least effective alternative.
Reduction ofToxicity, Mobility, or Volume through Treatment
Alternatives 4 and 7 achieve reduction of toxicity and mobility through transfer to another
facility. However, the overall volume of waste would increase as materials and equipment
become contaminated during excavation, handling, and disposal. Alternative 3 provides
treatment to immobilize contaminants for all soils exceeding industrial PTSM and CMCOC
standards. However, the grouting operations used to stabilize/immobilize the contaminants
would also increase the final volume of the contaminated media,
No form of treatment is involved with Alternative 2 (capping) to reduce toxicity, mobility, or
volume; however, Alternative 2 would reduce mobility through containment.
No form of treatment is involved with Alternative 1 to reduce toxicity, mobility, or volume;
however, the radioactivity at HRB, Warner's Pond, and HP-52 Ponds will slowly decrease
through radioactive decay. If no remedial action is taken, radioactivity at HRB
(which exhibits the highest levels) will decay to background levels through natural radioactive
decay in approximately 500 years.
Short-Term Effectiveness
Risk to Remedial Workers
The short-term risks to remedial workers increase with the volume of contaminated media
directly handled or processed and with project duration. Handling and/or processing
contaminated media increases the risk of remedial worker exposure to radiation effects. In
addition, remedial workers are exposed to potential construction-related risks, which increase
with project duration and depth of excavation. Using established health and safety procedures,
potential short-term risks to remedial workers should be manageable for all alternatives under
consideration.
Alternative 1 would offer the least risk to workers since the soils are not disturbed. Alternative 2
would offer a slightly greater risk by moving some contaminated soils and placing the barrier
wall and engineered cap. Alternative 3 would offer a slightly greater risk by moving the same
soils, mixing/grouting the soils, and placing the soil cover. Alternatives 4 and 7 would provide
higher risk because they involve excavating the largest volumes of soil, and then the soils must
be packaged, sampled, and shipped/transported, which results in greater handling and exposure
time.
Risk to Community
Alternatives 1, 2, 3, and 7 present no risk to the community because the contaminated soils
would remain within SRS boundaries. There would be no exposure concerns to the public
because the GSACU is located several miles from the nearest SRS boundary. Any increase in
off-SRS traffic would be negligible. Alternative 4 would present the greatest risk to the public
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Savannah River Site Rev. 0
August 2002 Page 53 of 79
because contaminated soils would be transferred over public railways and/or roadways to an
off-SRS disposal facility.
Time Until Protection is Achieved
The amount of time needed to achieve protectiveness after remedial action start is not
significantly different between the alternatives: Alternative 2 is 2 to 3 years and Alternatives 3,
4, and 7 are 3 to 4 years. Given that SRS has controls in place to prevent unacceptable exposure
to current workers, the time to construct the remedy is not identified as a key consideration in the
remedy selection process.
Implementability
The applied technologies (capping, in situ solidification/stabilization, and disposal) are common
for the disposition of hazardous waste units. Alternative 1 (No Action) would be the easiest
alternative to implement because it involves no construction. Alternative 2 (capping) involves
relatively straightforward, conventional construction activities and adequate material, equipment,
and contractor capabilities are available. Alternative 3 is implementable with standard
construction techniques, but any future remedial actions at HRB, Warner's Pond, or HP-52
Ponds would be difficult because the contaminated soil would be solidified with grout.
Alternative 7 would be implementable with standard construction and SRS transportation
procedures. Alternative 4 is also implementable, but may cause public concern regarding the
off-SRS transportation of radioactive waste.
Cost
Cost estimates for each alternative for HRB, Warner's Pond, and HP-52 Ponds are provided in
Table 6. Total estimated present-worth costs range from $0.3 million for Alternative 1 to $53.0
million for Alternative 4.
Comparative Analysis for ORWRG
Table 7 presents a summary of the evaluation of the alternatives against the comparative analysis
criteria. The evaluation is also briefly summarized below.
Overall Protection of Human Health and the Environment
For the ORWBG, all alternatives except Ho Further Action would be protective of human health
and the environment as long as institutional controls are in place. Institutional controls are a
component of all alternatives except No Further Action. Of all the potential remedial actions
(such as caps, intruder barriers, and in situ stabilization), institutional controls provide the
greatest level of protection of human health and the environment. For as long as they are
maintained, institutional controls would (1) prevent exposure by controlling erosion of the cover
(through site maintenance), (2) prevent inadvertent intrusion through land use restrictions, and
(3) limit infiltration and leaching through cover/cap maintenance. As long as institutional
controls are maintained, al 1 of the alternatives (except No Further Action) provide a comparable
level of overall protection of human health and the environment, although there is some
-------
Table 7. Comparative Analysis of Alternatives - ORWBG
>
EVALUATION
CRITERIA
OHWBG 1
No Further Action
ORWBG 11
Soil Cover
ORWBG III
Soil Cover with Light Rip-Rap
Barrier (over Entire ORWBG)
ORWBG VI
Low Permeability Cap
ORWBG VII
Low Perm. Cap with Light
Rip-Rap Barrier (over Entire
ORWBG)
Alternatives ORWBG II, III, VI, and VII Include options for (1) grouting all trenches within HS-llg-1, (2) placing heavy rip-rap
intruder barriers over selected radioactive hot spots, and (3) removing selected radioactive hot spots.
Overall Protection of Human Health and the Environment
Human Health
Environment
v
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>
Table 7. Comparative Analysis of Alternatives - ORWBG - Continued
EVALUATION
f^DITITQT A
t^KI 1 ILK1A
ORWBG I
No Further Action
ORWBG O
Soil Cover
Soil Cover with Light Rip-Rap
Barrier (over Entire ORWBG)
ORWBG VI
Low Permeability Cap
Low Perm. Cap with Light
Rip-Rap Barrier (over Entire
ORWBG)
Alternatives ORWBG H, in, VI, and VII include options for (1) grouting all trenches within HS-Hg-1, (2) placing heavy rip-rap
intruder barriers over selected radioactive hot spots, and (3) removing selected radioactive hot spots.
Compliance with ARARs ™_______-M_M_1^ , — —
Chemical-,
Location-, and
Action-Specific
Does not comply with AEA,
DOE Order 5400,5, or
infiltration control
requirements of RCRA.
Infiltration control
requirements of RCRA can
not be verified.
Infiltration control
requirements of RCRA can not
be verified.
Complies. The cap will meet
a performance standard for
hydraulic conductivity of
< 1 x 10"7 cm/sec.
Complies. The cap will meet
a performance standard for
hydraulic conductivity of
< 1 x 10'' cm/sec.
Lone-Term Effectiveness and Permanence ___^__ __^__ . _______
Magnitude of
Residual Risks
*
Low. The existing native soil
cover already isolated
contamination at depth.
Risk would generally decrease
with radioactive decay, but if
inadvertent intrusion were to
occur, some hot spots would
pose a long-term (>500 years)
acute and/or chronic exposure
threat.
Low. The existing native
soil cover already isolated
contamination at depth.
Access controls would
prevent unauthorized entry
and site maintenance would
prevent exposure by
preventing erosion of the
cover.
In the absence of access
controls, there would be no
protection against
inadvertent intrusion or
long-term
erosion/exhumation of the
waste. Residual risk would
be high.
If any wastes are removed
from the hot spots, the
remaining wastes in the hot
spot would pose a similar
risk to those parts of the
ORWBG not identified as
hot spots.
Low. The existing native soil
cover already isolated
contamination at depth.
If institutional controls are
terminated, the light rip-rap
barrier would provide some
reduction of residual risk
because it would provide some
protection against inadvertent
intrusion and long-term
erosion/exhumation of the
waste. If institutional controls
are maintained, a barrier is a
redundant remedy component.
If any wastes are removed from
the hot spots, the remaining
wastes in the hot spot would
pose a similar risk to those
parts of the ORWBG not
identified as hot spots.
Same as ORWBG II.
Same as ORWBG III.
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Table 7. Comparative Analysis of Alternatives - ORWBG - Continued
EVALUATION
CRITERIA
Permanence
ORWBG I
No Further Action
Not permanent. The native soil
cover would erode and there
would be the possibility of
future exhumation of waste by
erosion and intrusion.
ORWBG H
Soil Cover
ORWBG in
Soil Cover with Light Rip-Rap
Barrier (over Entire ORWBG)
ORWBG VI
Low Permeability Cap
ORWBG vn
Low Perm. Cap with Light
Rip-Rap Barrier (over Entire
ORWBG)
Alternatives ORWBG II, HI, VI, and VII include options for (1) grouting all trenches within HS-Hg-1, (2) placing heavy rip-rap
intruder barriers over selected radioactive hot spots, and (3) removing selected radioactive hot spats.
A soil cover is subject to
erosion and deterioration,
but permanence can be
achieved through inspection
and maintenance associated
with institutional controls.
In situ stabilization of HS-
Hg-1 would provide some
permanence but this action
would be redundant as long
as institutional controls are
in place.
Intruder barriers over
radioactive hot spots would
be designed for long-term
effectiveness and durability.
Same as ORWBG 11 except:
A light rip-rap barrier would
provide greater permanence of
the soil cover but would be
redundant as long as
institutional controls are in
place.
Same as ORWBG 11.
Same as ORWBG 11 except:
A light rip-rap barrier would
provide greater permanence
of the cap but would be
redundant as long as
institutional controls are in
place.
Reduction in Toxicity, Mobility, or Volume Through Treatment
Degree of Expected
Reduction in
Toxicity
No reduction other than natural
radioactive decay.
No reduction other than
natural radioactive decay.
No reduction other than natural
radioactive decay.
No reduction other than
natural radioactive decay,
No reduction other than
natural radioactive decay.
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Table 7. Comparative Analysis of Alternatives - ORWBG - Continued
EVALUATION
CRITERIA
Degree of Expected
Reduction in
Mobility
Degree of Expected
Reduction in
Volume
ORWBG 1
No Further Action
No reduction of mobility.
No reduction in volume.
ORWBG II
Soil Cover
ORWBG III
Soil Cover with Light Rip-Rap
Barrier (over Entire ORWBG)
ORWBG VI
Low Permeability Cap
ORWBG VII
Low Perm. Cap with Light
Rip-Rap Barrier (over Entire
ORWBG)
Alternatives ORWBG II, III, VI, and VII include options for (I) grouting all trenches within HS-Hg-1, (2) placing heavy rip-rap
Intruder barriers over selected radioactive hot spots, and (3) removing selected radioactive hot spots.
Reduction through
containment (soil cover).
Because the leachabilily
threat of mercury is low and
the cover is expected to be
maintained in the long-term,
stabilizing HS-Hg-1 would
provide negligible reduction
in contaminant migration
and would be a redundant
response to the infiltration
control system. Further, in
siltt activities could rupture
any intact containers,
releasing additional
mercury.
If grout is injected into HS-
Hg-l, volume of
contaminated media would
increase.
If wastes in the radioactive
hot spots are removed, the
overall volume of waste
would increase as materials
and equipment become
contaminated during
removal, handling, staging,
transportation, storage, and
disposal.
Reduction through containment
(soil cover).
Because the teachability threat
of mercury is low and the
cover is expected to be
maintained in the long-term.
stabilizing HS-Hg-1 would
provide negligible reduction in
contaminant migration and
would be a redundant response
to the infiltration control
system. Further, In situ
activities could rupture any
intact containers, releasing
additional mercury.
Same as ORWBG 11.
Reduction through
containment (low
permeability cap meeting
performance standard for
hydraulic conductivity of
< ! x 10'' cm/sec).
Because the leachabilily
threat of mercury is low and
the cover is expected to be
maintained in the long-term.
stabilizing HS-Hg-1 would
provide negligible reduction
in contaminant migration and
would be a redundant
response to the infiltration
control system. Further, in
situ activities could rupture
any intact containers,
releasing additional mercury.
Same as ORWBG II.
Reduction through
containment (low
permeability cap meeting
performance standard for
hydraulic conductivity of
< 1 x IO'7 cm/sec).
Because the leachability
threat of mercury is low and
the cover is expected to be
maintained in the long-term,
stabilizing HS-Hg-1 would
provide negligible reduction
in contaminant migration and
would be a redundant
response to the infiltration
control system. Further, In
situ activities could rupture
any intac! containers.
releasing additional mercury.
Same as ORWBG II.
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Table 7. Comparative Analysis of Alternatives - ORWBG - Continued
EVALUATION
CRITERIA
ORWBG i
No Further Action
ORWBG JI
Soil Cover
ORWBG HI
Soil Cover with Light Rip-Rap
Barrier (over Entire ORWBG)
ORWBG VI
Low Permeability Cap
ORWBG VII
Low Perm. Cap with Light
Rip-Rap Barrier (over Entire
ORWBG)
Alternatives ORWBG II, III, VI, and VII Include options for (1) grouting ail trenches within HS-Hg-1, (2) placing heavy rip-rap
intruder barriers over selected radioactive hot spots, and (3) removing selected radioactive hot spots.
Short-Term Effectiveness
Risk to Remedial
Workers
Risk to Community
Time Until
Protection is
Achieved
None. No onsite work.
None. No additional activities.
N/A
Negligible risk associated
with heavy equipment use to
place soil cover.
Stabilization of HS-Hg-1
would pose high to
unacceptable risk from the
possibility of direct
exposure. Risk would be
proportional to the extent of
stabilization and the method
used.
Removal of wastes from
radioactive hot spots would
present high to unacceptable
risk associated with
intrusive activities.
On-unit activities (cover/cap
construction, stabilization of
HS-Hg-1 ) pose no exposure
concerns; unit is located
several miles from the
nearest SRS boundary,
Removal of radioactive hot
spots would present some
risk to community as wastes
would ultimately transported
on public rights-of-way to
an oft-SRS disposal facility.
1 year
Same as ORWBG I! except
more extensive heavy
equipment use to place barrier.
Same as ORWBG II.
1-2 years
Same as ORWBG II except
more extensive heavy
equipment use to place low
permeability cap.
Same as ORWBG II.
2-3 years
Same as ORWBG 11 except
more extensive heavy
equipment use to place low
permeability cap and barrier.
Same as ORWBG 11.
3-4 years
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Table 7. Comparative Analysis of Alternatives - ORWBG - Continued
EVALUATION
CRITERIA
Implemcntability
Technical
Feasibility
Administrative
Feasibility
Availability of
Materials,
Equipment,
Contractors
ORWBG I
No Further Action
ORWBG II
Soil Cover
ORWBG III
Soil Cover with Light Rip-Rap
Barrier (over Entire ORWBG)
ORWBG VI
Low Permeability Cap
ORWBG VII
Low Perm. Cap with Light
Rip-Rap Barrier (over Entire
ORWBG)
Alternatives ORWBG II, HI, VI, and VII include options for (1) grouting all trenches within HS-Hg-1, (2) placing heavy rip-rap
intruder barrier; over selected radioactive hot spots, and (3) removing selected radioactive hot spots.
Readily imptementable.
No administrative constraints
to implementation.
No materials, equipment, or
contractors required.
Installation of the soil cover
is implementable. However,
portions of the remedy
present major
implementabtlity concerns.
The heterogeneous nature of
the waste, the absence of
reliable verification
methods, and radiological
health and safety present
significant challenges to the
feasibility of in situ
stabilization of HS-Hg-1 and
removal of wastes from the
radioactive hot spots,
No administrative
constraints to
implementation.
Institutional controls readily
implementable.
Removal of radioactive hot
spots would present some
difficulty finding qualified
contractors.
Same as ORWBG II.
Same as ORWBG H.
Removal of radioactive hot
spots would present some
difficulty finding qualified
contractors.
SameasORWBGH.
Same as ORWBG 11.
Removal of radioactive hot
spots would present some
difficulty finding qualified
contractors.
Same as ORWBG 11.
Same as ORWBG II.
Removal of radioactive hot
spots would present some
difficulty finding qualified
contractors.
Cost (present value, in millions)
Capital Cost
O&M Cost
Total Cost
$0.0
$<0.1
$<0.1
$0.8
$1.2
$2.0
$11.2
$1.2
$12.4
$10.8
$1.2
$12.0
$21.3
$1.2
$22.5
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Costs are rounded to the nearest $0.1 million. The present value cost of No Further Action is less than $0.1 million: capital costs are SO, O&M costs (five-year ROD reviews) are $47,435.
Optional Costs (not included in total costs shown in table):
In-situ grouting of all trenches in HS-Hg-1 = $8.0 million
Heavy rip-rip intruder barrier over persistent hot spots = $325,000/acre ($ 1.4 million for HS-500-1 through -8) (Present value = S31,000, based on 3.9% discount rate and implementation
in 100 years). This is the capital cost to furnish and install the rip-rap only. The O&M cost of cap reconstruction after placement of the barrier is included in the long-term O&M costs
for the ORWBG cap, which also includes periodic refurbishment of the cap.
Removal of hot spots containing potentially removable wastes = $100 million
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ROD for the GSACU (U) WSRC-RP-2002-4002
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uncertainty whether a soil cover would provide sufficient protection against future leaching to
groundwater.
No Further Action would not provide overall protection of human health and the environment. If
erosion and intrusion are not mitigated, exposure could occur if the waste were to be eventually
exhumed. Also, if the existing soil cover is not maintained, the cover would slowly deteriorate
by erosion and leaching would increase.
Compliance with ARARs
Alternatives with a low permeability cap (ORWBG VI and VII) would comply with all ARARs.
The low permeability cap would ensure compliance with the infiltration control requirements in
RCRA. For alternatives having the native soil cover as the only infiltration control system
(ORWBG I, II, and III), compliance with RCRA regulations for infiltration control could not be
verified without additional characterization. ORWBG I (No Further Action) would not comply
with the AEA or USDOE Order 5400,5 because the unit could be released from USDOE,
control. The AEA states that "source, byproduct, and special nuclear materials must be
regulated... to protect the health and safety of the public." The ORWBG contains by-product
material (radioactive material yielded radioactive by exposure to radiation incident to the
production or utilization of special nuclear materials). The ABA precludes USDOE from
transferring property containing radioactive waste ta non-federal ownership. Table 4 identifies
potential ARARs,
Long-Term Effectiveness and Permanence
All ORWBG alternatives will result in similar levels of residual risk to human receptors because
there will be no current exposure pathways upon completion of the remedial action. The existing
native soil cover already isolates the contamination under clean soil, and institutional controls (a
component of all alternatives except No Further Action) would prevent invasive activities.
With respect to permanence, a native soil cover and low permeability cap are both subject to
erosion and deterioration, but permanence can be achieved through inspection and maintenance
associated with institutional controls. Maintenance and repair associated with institutional
controls is the most effective and reliable method to achieve permanence. Institutional controls
for the ORWBG are anticipated to be maintained in perpetuity. Periodic inspections and routine
maintenance associated with institutional controls, such as repair of erosion and subsidence of
the cover, would be required in the long-term, No Further Action offers no permanence because
institutional controls (including maintenance of the native soil cover) would not be implemented.
The native soil cover would deteriorate by erosion and there would be the possibility of future
exhumation of waste by erosion and intrusion,
A light rip-rap barrier over the entire ORWBG would provide some additional permanence. A
barrier is durable and can extend the effective life of a cover by reducing the amount of
deterioration from bioturbation, but even barriers have some minimal maintenance requirements.
As long as institutional controls (maintenance and access controls) are in place, a barrier would
be a redundant technology. The benefit of a barrier would only be realized if institutional
controls are relinquished, as institutional controls provide greater protection of the cover and
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better protection against intrusion. Any decisions on selection of a barrier system must include
an assessment of undesirable habitat creation for plants and animals.
For HS-Hg-1, in situ stabilization of HS-Hg-1 would provide some long-term isolation of waste,
but as long as institutional controls (maintenance requirements and access controls) are in place,
in situ stabilization of HS-Hg-1 would be a redundant technology.
For the radioactive hot spots, any one of the three options (No Further Action, Intruder Barrier,
Removal) provides some permanence. Reliability of remedy components is not applicable for the
No Further Action alternative; there are no remedy components, An intruder barrier provides
some permanence because it is designed for long-term durability with minimal maintenance
requirements. The long-term reliability (to 1,000 years) of intruder barriers has not been
demonstrated, but the barriers would be constructed of a resistant material such as rip-rap.
Rip-rap may have greater permanence than reinforced concrete. Removal is permanent because
the source term would be removed from the unit and relocated to another facility. Removal of
wastes from radioactive hot spots would result in an overall increase of long-term monitoring
requirements as the monitoring requirements would be transferred to the receiving facility.
Reduction ofToxicity, Mobility, or Volume Through Treatment
Degree of Expected Reduction in Toxicity
None of the alternatives are intended to reduce contaminant toxicity. Natural radioactive decay
will slowly reduce the inventory of short-lived radionuclides, but long-lived radionuclides and
non-radioactive contaminants will persist.
Degree of Expected Reduction in Mobility
All alternatives (except No Further Action) would reduce infiltration and associated leaching
through containment. A low permeability cap would provide some additional reduction in
infiltration compared to a native soil cover.
In situ stabilization of HS-Hg-1 is the only remedial activity that reduces contaminant mobility
through treatment. Because the teachability threat of mercury is low and the cover is expected te
be maintained in the long-term, stabilizing HS-Hg-1 would provide negligible additional
reduction in contaminant migration and would be a redundant response to the in61tration control
system. Further, in situ activities could rupture any intact containers, releasing additional
mercury.
Degree of Expected Reduction in Volume
None of the alternatives for the ORWBG as a whole and HS-Hg-1 reduce volume through
treatment.
For removal options for the radioactive hot spots, the source volume would be reduced by
transfer out of the ORWBG and into another facility. However, the net volume of waste would
increase as materials and equipment associated with excavation repackaging and disposal
operations are contaminated. Likewise, some equipment supporting in situ stabilization of
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HS-Hg-1 may be contaminated and will need to be packaged and disposed off unit. In situ
stabilization would result in some increase in waste volume as the grout/reagent injected into the
subsurface would contact the waste and become contaminated.
Short-Term Effectiveness
Risk to Remedial Workers
For the ORWBG as a whole, the risks associated with the non-intrusive activities are minimal
and are proportional to the extent of heavy equipment use. There would be more heavy
equipment use required to construct a low permeability cap than to expand the native soil cover;
however this risk is readily managed using standard safety procedures.
For HS-Hg-1, alternatives that involve in situ stabilization present high to unacceptable risk to
remedial workers because in situ stabilization involves intrusive activities. There is a high risk of
direct exposure during in situ stabilization (e.g., from rupture of a buried container). The risk is
proportional to the extent of grouting (proportional to the number of injection holes) and depends
on the method used. There is also some uncertainty with the safety of grouting in this
application. Large and rigid buried objects can obstruct grouting equipment which may result in
direct contact or unnecessary exposure associated with field repairs and troubleshooting.
Grouting trenches poses high to unacceptable risk to remedial workers.
For the radioactive hot spots, there is no risk to workers associated with No Further Action
because no additional activities would be performed. Emplacing a barrier is a non-intrusive
activity that presents minimal risk associated with heavy equipment use. Removal and disposal
of the radioactive hot spots presents high to unacceptable risk to workers - primarily due to
uncertainties with (1) unacceptable risk to workers for removal of some wastes, including
containerized and uncontainerized fission product wastes; (2) wastes not being removable
because the original burials were not containerized, such as carbon-14 deionizer resins; and (3)
unsegregated wastes.
Risk to Community
None of the alternatives for the ORWBG as a whole or HS-Hg-1 pose a risk to the community.
The ORWBG is located in the interior of the SRS several miles from the nearest SRS boundary.
There are no exposure concerns because the general public is prohibited from entering the SRS.
There would be a negligible increase in off-SRS vehicular traffic associated with each
alternative.
For the radioactive hot spots, removal presents the greatest risk to the community because
exhumed transuranic waste would ultimately be shipped over public roadways or railways to an
offsite disposal facility such as WIPP.
Time Until Protection is Achieved
The amount of time needed to achieve protectiveness after start of remediation ranges from 1
year for ORWBG II to 3 to 4 years for ORWBG VII. Construction of a low permeability cap
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would take somewhat longer than expansion of the native soil cover. For the radioactive hot
spots, removal would take longer than emplacing a barrier.
Because the buried waste does not pose a current exposure threat, and because the existing native
soil cover provides infiltration control, there are no imminent risks and the time until
remediation is complete is not identified as a key consideration in the remedy selection process.
Implementability
Technical Feasibility
For the ORWBG, the non-intrusive activities such as expansion of a native soil cover,
construction of a cap, or placement of a barrier are standard construction activities and pose no
implementability restrictions,
In situ stabilization of HS-Hg-1 does present significant implementability challenges. For this
alternative where no exhumation is involved, the presence of a large amount of debris in the
subsurface would obstruct the injection of treatment materials such as grout or chemical fixation
compounds. This would result in difficulty in achieving the desired remedial objective, difficulty
in verifying performance criteria, and radiological health and safety concerns. In situ
stabilization is still an emerging technology and would require advancement before it could meet
the desired remedial objective at this hot spot.
The technical feasibility of removing wastes in the radioactive hot spots does present significant
implementability concerns. The technical feasibility is specific to each hot spot. It is not
technically feasible to remove wastes such as uncontainerized fission product wastes and
deionizer resins because removal would result in unacceptable risk to workers. For other wastes,
the technical feasibility is dependent on the timing of removal; some wastes may not be
removable until co-located short-lived radionuclides, such as cobalt-60, have decayed to lesser
activities.
Administrative Feasibility
There are no administrative constraints to implementation. Institutional controls are readily
implementable in the near-term as we 11 as in the long-term provided the area remains under
USDOE or federal government control.
Availability of Materials. Equipment and Contractors
None of the non-intrusive activities would pose an implementability concern related to
availability of materials, equipment, or contractors. Removal of radioactive hot spots would
present some difficulty finding qualified contractors.
Cost
Cost estimates for the potential remedial actions for the ORWBG are presented on Table 7.
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XL THE SELECTED REMEDY
Based upon the evaluation of alternatives, the selected remedy for HRB, Warner's Pond, and
HP-52 Ponds is Alternative 7 (Consolidation at the ORWBG) and the selected remedy for the
ORWBG is Alternative ORWBG VI (Institutional Controls with Low Permeability Cap).
Individual intruder barriers will be installed over the long-lived persistent radioactive hot spots
(HS-500-1 through HS-500-8) before institutional controls are terminated at the ORWBG. The
options of in situ stabilization of HS-Hg-1 and removal of the radioactive hot spots will not be
implemented.
Figures 14 through 17 are schematic illustrations of the selected remedy at each unit.
Rationale for Selecting the Remedy
The rationale for selecting this remedy over the other alternatives includes the following:
• The remedy satisfies the preference to remove PTSM and CMCOCs at HRB, Warner's
Pond, and HP-S2 Ponds to the extent practicable.
Consolidation of material at the ORWBG is less expensive than disposal at an off-SRS
facility and does not involve transportation of radioactive wastes on off-SRS public
rights-of-way.
• A low permeability cap over the ORWBG is selected instead of a native soil cover
because (1) other similar facilities at SRS were closed using a low permeability cap, (2) it
is a common standard of infiltration control for low permeability caps, and (3) it manages
uncertainty with the teachability risk posed by the ORWBG.
A light rip-rap barrier over the entire ORWBG is not selected because its utility at
preventing intrusion and erosion is a redundant action to institutional controls, which will
prevent inadvertent intrusion. Furthermore, a barrier may create habitat for deep-rooting
plants and burrowing animals which could negatively affect the low permeability cap.
• Stabilization of HS-Hg-1 is not selected because (1) HS-Hg-1 does not pose a risk that is
significantly different than the ORWBG as a whole, (2) invasive activities may rupture
my intact containers of mercury that may exist, (3) there is uncertainty
with the technical feasibility of grouting among debris as buried objects can obstruct grouting
equipment and there may not be a reliable verification method in this application, (4) invasive
activities would create unnecessary risks to the workers involved, and (5) the low permeability
cap and institutional controls in place for the ORWBG as a whole will provide sufficient
protection of HS-Hg-1.
Removal of the radioactive hot spots in the OR%BG is not selected because invasive
work would create unnecessary risks to the workers involved.
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Current Conditions:
Sewer Line* f
Discharge Area Basin /
/ Cs-137, Sr-90 N^ / Cs.137.
O / Sr-gfl
N^ BasinBiilttnn/Sidc»alIsi;PTSM) /
Cs-137, Sr-90. Ara-241, As, Cs-137.
<»« %%s%r
Pu- 239^240, Th-228, U-238
Leaching Sr-90, Pu-23 91/240 Pt:rt:lu;il_Walur
\7 J I Hardpan
:V 5^
1 p|jtr Tlirfe Ruri.s Ai|Liiier
Sail Pile
(PTSMi
Cs-137, Sr-90. \
Ctn-243/244, \
Eu-154 \
Human Health
Exposure Risk
Ecological Exposure
Risk
Contaminant Migration
(JLeachability) Threat
Selected Remedy:
Sewer I .iiuv'
Discharge Area
Soil Cover
Rt'siiliml t:untaminution
covered lo prevejit human
health or ecological
uxpmuru Basin
Basin Bottoin/Sidcvi-alls
Residual CMCOCs
mitigated by cover '
PTSM mid CMCOCs removed,
Excavation backfilled
Sr-90
Soil Pile
(Rtrnuvwl")
Cover reduces amount
of perched water
Hardpan
Upper Three Runs Aquifer
(Not pnrl ui'tlie USAt'L , eialunltd stpuralt-lj unUcr I he HAdtH!)
Figure 14. Schematic Illustration of Selected Remedy at 11KB
(figure not to scale)
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Current Conditions:
RailroaJ
/~\
.XJ
Fonnui PonJ Area (PTSM) /~^\
Break
Sr-90. Arn-241,1-129. K-40, Hg
Divers km I I
niPsl
Box.
Upper 1 hree Runs Ai|uifer
LEGEND
(Human Health
Exposure Risk
Contaminant Migration
(Leachabilily) Threat
Selected Remedy:
Foimci Poiul Area and HIPSI. Exc&VUftcd and
Backfilled, COCs Removed
Soil Cover
Pipeline
Break
Bemis, pipcluu:>.. divctxirm bo\ removed
where in furHi«.-l wiLh PTSM and CMCOCs
KesidualCMCOCs
igiitcd b)1 soil
HIPSI.gmulcd
under railroad
Perched water reduced by soil
cover antl by removing Lxir'rns
: I lardpan
Upper Three Runs Aquifer
(Not part of the G S A CU, evaluated separately under the 11AGOL 1
Figure 15. Schematic Illustration of Selected Remedy at Warner's Pond
(figure not to scale)
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Current Conditions:
\J
lll-
Effluent Ditch
- -.
Former Pondi
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Current Conditions:
.Mauve Soil Cover
Placed in 1996
3-8 ft thick
Emptied in 1977
Grouted in 2001-2002
M
0)
Buried in 1952-1974
(Constitutes ITSMt
Surface exposure risk of buried
wasu mitigated by original backfill
and narive soil cover
V
Possible
priiir in
granting
Constituents of Interest.
Cd. Pb. llg VOCs, Triiium.
Ca-m. Pii-238, Pu-m Sr-cii-iieiihilitv cap
irie native soil i:r.i
Consolidate Waste from MRS.
WiirnHr's florid. HP SI Pimils ~J
Implemenl inslilnliona)
cantiols:
inspections, mowing.
housekeeping.
rn iiihTiiini. cap repair
fences, sips, [and use
restrictions
n
^ J
(grouted)
" mi
Leaching
mitigsleri hy ln»
permeabtlily cap
Snrl'iiLe t;x|i[)sun: n i. i] lurir
wasle niiiiiL.ncJ by origin til backfill
and native soil cover
Upper Tliri'i1 RUII.S AqnilYr
l by Ihc (orrcclivc aclinn program in tht SItS HCUA I'iirt B permit for the MVVMi i
Figure 17. Schematic Illustration of Selected Remedy at ORWBG
(figure not to scale)
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How the Selected Remedy Will Meet the RAOs
The selected remedy will meet the RAOs for HRB, Warner's Pond, and HP-52 Ponds as follows:
• Treat and/or remove PTSM (based on toxicity by treating and/or removing cesium-137 at
HRB. Warner's Pond, and HP-52 Pond at levels above 104 pCi/g. to the extent
practicable: PTSM will be removed to the extent practicable.
• Treat and/or remove PTSM (based on mobility) by treating and/or removing strontium-90
at the HRB sewer line/discharge area at levels above 0.65 pCi/g. to the extent practicable:
PTSM will be removed to the extent practicable.
• Control migration and leaching of strontium-90 that could result in groundwater
contamination in excess of MCLs in the UTRA beneath a unit by (1) removing soil above
1.5 pCi/g at the HRB basin bottom/sidewalls. above 0.65 pCi/g the HRB sewer
line/discharge area, and above 1.12 pCi/g at Warner's Pond, to the extent practicable: and
(2) reducing infiltration through any residual contamination above RGs: Soil containing
CMCOCs above RGs will be removed to the extent practicable. Also, a soil cover will be
placed over any residual contaminants to minimize infiltration so that no unit-related
contaminants will cause MCL exceedances in the UTRA beneath a unit and so that the
accumulation of perched water atop the hardpan is minimized.
Protect human and ecological receptors from surface materials containing cesium-137
above 0.55 pCi/g and strontium-90 above 57.2 pCi/g: After PTSM and CMCOCs are
removed, the excavations will be backfilled and covered with clean soil that poses no
more risk than ambient background levels.
The selected remedy will meet the RAOs for the ORWBG as follows:
• Minimize the exposure risk to workers (current and future): The selected remedy for the
ORWBG will not involve invasive activities (i.e., treatment or removal of HS-Hg-1 or
the radioactive hot spots), so remedial workers will not be exposed to unnecessary risks
associated with invasive activities. Maintenance of the low permeability cap will isolate
contamination under clean soil, therefore future workers will not be exposed to surface
contamination.
• Prevent or mitigate inadvertent human intrusion: Institutional controls will prevent
inadvertent human intrusion into the ORWBG through physical controls (fences and
warning signs) and administrative controls (SRS Site Use and Site Clearance Programs),
The selected remedy mandates that physical intruder barriers be placed over the 500-year
hot spots prior to termination of institutional controls.
• Minimize ecological intrusion into the buried waste and redistribution/mobilization
(erosion) of contaminants from the waste unit to the surrounding areas: The low
permeability cap will be maintained as needed to isolate contamination under clean soil,
prevent trees from growing on the cap (thus preventing deterioration by tree roots), and
prevent erosion from exhuming contaminants where they could be redistributed at the
surface by wind and water.
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• Mitigate future leaching of contaminants to groundwater: The low permeability cap will
be placed over the ORWBG to mitigate future leaching.
Detailed Description of the Selected Remedy
The selected remedy includes the following activities:
1. Excavate materials constituting industrial PTSM and soil containing CMCOCs above
RGs at HRB, Warner's Pond, and HP-52 Ponds to the extent practicable. The excavation
will not breach the integrity of the hardpan. Soil RGs for CMCOCs are established to
prevent leaching of constituents to groundwater at concentrations above MCLs within
1,000 years. Table Sb provides additional explanation regarding the generation of soil
RGs for CMCOCs.
2. Manage standing surface water (in HRB) and water which accumulates during excavation
by solidification and consolidation with the excavated soil and/or by another means such
as treatment at the Effluent Treatment Facility (ETF).
3. Consolidate the excavated soil and material by transferring it to the areas of the ORWBG
that have not yet been covered by the native soil cover (e.g., over the OSTs). In the
unlikely event that there is insufficient available space at the ORWBG, ship the excess
waste to an off-SRS facility approved to receive CERCLA remediation waste.
4. When inactive pipelines are encountered during removal of soil, excavate those sections
of the pipelines with the soil. At Warner's Pond, this will include the inactive CERCLA
pipelines within the berms, the diversion box, and the RCRA-regulated HIPSL.
Characterization data show that soil around the HIPSL is non-hazardous. Sections of the
HIPSL and any contents will be sampled and analyzed during the characterization of
Warner's Pond to determine if they are hazardous in accordance with South Carolina
Hazardous Waste Management Regulation R.61-79.261. If the HIPSL pipeline or its
contents are hazardous, these materials will not be consolidated into the ORWBG. A
RCRA Closure Plan will be developed to document the disposition of the RCRA
pipeline. The RCRA closure plan will be approved by SCDHEC prior to remedial action
on the HIPSL (indicated in yellow on Figure 4).
For remaining intact portions of inactive pipelines, including portions that are not in
contact with PTSM or cannot be readily removed (such as the section of the HIPSL under
the railroad track), plug the ends of the pipelines and grout in place. If a pipeline is not
intact, cannot be reliably grouted in place, and is non-hazardous, remove it and
consolidate it with the soil transferred to the ORWBG. Risks posed by remnant
contamination in soil after excavation will be determined prior to backfilling.
5. Consolidate any vegetation in contact with PTSM by removing it and transferring it to
the ORWBG. Vegetation will be shredded, chipped, or spatially distributed and
incorporated into the excavated soil. Placement of this material at ORWBG will be
engineered in a manner that minimizes subsidence.
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6. Evaluate the risk of remnant material after excavation at HRB, Warner's Pond, and HP-52
Ponds. Contaminant migration risk from the potential source to the UTRA beneath each
unit will be evaluated.
7. Mitigate residual risk at HRB, Warner's Pond, and HP-52 Ponds by backfilling and
placing clean soil over open excavations that contain residual contamination exceeding
RGs. A soil cover will be used to minimize infiltration so that (I) no unit-related
contaminants will cause MCL exceedances in the UTRA beneath each unit, and (2) the
accumulation of perched water atop the hardpan is minimized.
8. Restore surface water drainage at Warner's Pond to a natural state by removing the berms
that cause ponding of water.
9. Prepare a post-construction report for HRB, Warner's Pond, and Hp-52 Ponds to
summarize the remediation activities and summarize how residual risks are addressed.
10. Implement institutional controls at HRB, Warner's Pond, and HP-52 Ponds. Institutional
controls will consist of site maintenance (site inspections, mowing, general
housekeeping, repair of erosion damage, and other routine maintenance as needed) and
access controls (warning signs and land use restrictions). Institutional controls will
include continued use of SRS's Site Use and Site Clearance Programs to restrict
disturbance of the cover system and waste at each unit and to prevent drinking water use
of contaminated groundwater under each unit.
11. Construct a low-permeability geosynthetic cover system (with a soil hydraulic
conductivity of <1 x 10"7 cm/sec) over the ORWBG; including the areas where
consolidated materials from HRB, Warner's Pond, and HP-52 Ponds were placed; but
excluding the areas between interim covers B and D. A hydraulic conductivity of <1 x
10"7 cm/sec is selected because it provides infiltration control that sufficiently manages
uncertainties related to residual contamination without further investigation, and it is
consistent with low permeability caps placed over similar facilities at SRS. Contiguous
facilities associated with SRS's active Solid Waste Management Program (such as
643-7E/643-SE and associated paved parking areas) will not be covered by the cap.
These facilities will continue to actively support SRS solid waste activities at least until
all transuranic waste stored at SRS has been shipped to WIPP.
12. Implement institutional controls at the ORWBG. Institutional controls will consist of site
maintenance (site inspections, mowing, general housekeeping, repair of erosion damage,
other routine maintenance as needed, and periodic maintenance of the infiltration control
system) and access controls (security fences, warning signs, and land use restrictions).
Institutional controls will include continued use of SRS's Site Use and Site Clearance
Programs to restrict disturbance of the cover system and waste at the unit and to prevent
drinking water use of contaminated groundwater under the unit.
13. Before institutional controls are terminated at the ORWBG, install intruder barriers over
the long-lived persistent radioactive hot spots (hot spots HS-500-1 through HS-500-8) to
deter inadvertent human intrusion. The likely configuration of the intruder barrier is
heavy rip-rap. The barrier will be installed above the low permeability cap but beneath a
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soil cover. Covering the rip rap will minimize development of an undesirable habitat
(e.g., a habitat among rip-rap favorable for deep-rooting plants and burrowing animals
that could degrade the low permeability cap). Placement of the barrier will not interfere
with the long-term integrity of the cap. A reasonable estimated timeframe for installing
the intruder barrier is 100 years. The barrier will not be installed until institutional
controls are terminated; the USDOE expects to maintain institutional controls at the
Burial Ground Complex for at least 100 years.
The selected remedy leaves hazardous substances in place that pose a potential future risk and
will require land use restrictions for an indefinite period of time. As negotiated with USEPA, and
in accordance with USEPA-Region IV policy (Johnston 1998), SRS has developed a Land Use
Control Assurance Plan (LUCAP) (WSRC 1999) to ensure that land use restrictions are
maintained and periodically verified. A unit-specific Land Use Control Implementation Plan
(LUCIP) will provide detail and specific measures required for the land use controls selected as
part of this remedy. USDOE-Savannah River Operations Office is responsible for implementing,
maintaining, monitoring, reporting upon, and enforcing the land use controls under this ROD.
The LUCIP selected as part of this action will be submitted concurrently with the Corrective
Measures Implementation/Remedial Action Implementation Plan (CMI/RAIP), as required in the
FFA, for review and approval by USEPA and SCDHEC. Upon final approval, the LUCIP will be
appended to the LUCAP and is considered incorporated by reference into the ROD, establishing
LUC implementation and maintenance requirements enforceable under CERCLA. The approved
LUCIP will establish implementation, monitoring, and maintenance, reporting, and enforcement
requirements for the unit. The LUCIP will remain in effect until modified as needed to be
protective of human health and the environment. LUCIP modification will only occur through
another CERCLA document.
USDOE expects to retain control of the GSACU for the foreseeable future. However, in the
unlikely case the property is transferred to nonfederal ownership, the U.S. Government will take
those actions necessary pursuant to Section 120(h) of CERCLA. Those actions will include a
deed notification disclosing former waste management and disposal activities as well as remedial
actions taken on the individual subunits of the GSACU. The contract for sale and the deed will
contain the notification required by CERCLA Section 120(h). The deed notification shall, in
perpetuity, notify any potential purchaser that the property has been used for the management
and disposal of waste. These requirements are also consistent with the intent of the RCRA deed
notification requirements at final closure of a RCRA facility if contamination remains at the OU.
The deed shall also include deed restrictions precluding residential use of the property.
However, the need for these deed restrictions may be reevaluated at the time of transfer in the
event that exposure assumptions differ and/or the residual contamination no longer poses an
unacceptable risk under residential use. Any reevaluation of the need for the deed restrictions
will be done through an amended ROD with USEPA and SCDHEC review and approval.
In addition, if the site is ever transferred to nonfederal ownership, a survey plat of the OV will be
prepared, certified by a professional land surveyor, and recorded with the appropriate county
recording agency.
The five-year review requirement, a CERCLA ROD review, will be conducted every five years
to determine whether the remedy is meeting RAOs.
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The remedy may change as a result of the remedial design or construction processes. Changes to
the remedy described in the ROD will be documented in the Administrative Record File utilizing
a memo, an Explanation of Significant Difference (BSD), or a ROD Amendment.
Cost Estimate for the Selected Remedy
The present worth costs for this remedy are as follows:
Capital Cost: 537.4 million
Operations and Maintenance (O&M) Cost: $3.9 million
Total Present Worth Cost: $41.3 million
For HRB, Warner's Pond, and HP-52 Ponds, these costs include removing PTSM and CMCOCs,
backfilling and restoring the excavations, installing a soil cover, and implementing institutional
controls ($29.3 million, see Alternative 7 on Table 6). For the ORWBG, these costs include
constructing a low permeability cover, implementing institutional controls, and performing
five-year ROD reviews ($12.0 million, see Alternative ORWRG VI on Table 7). In addition, the
cost includes placing intruder barriers over the 500-year radioactive hot spots before institutional
controls are relinquished ($31,000). Cost estimates were generated using a 3.9% interest
(discount) rate. The net present value cost for intruder barriers is based on an assumption that the
barriers will be placed 100 years in the future. For five-year CERCLA ROD reviews,
institutional controls, and cap maintenance/repair, a 500-year time period was used for cost
estimating purposes; however, there is no time limit on these activities. The ROD will be
reviewed every five years to assess whether the remedy is still meeting RAOs. Although there is
no time limit on the five-year review requirement or institutional controls, the net present value
for this long-term cost is negligible. Appendix B provides tables of cost estimates for the
selected remedy.
The GSACU is owned by USDOE, which is responsible for the contamination, has performed
the site investigation, and will be the source of the cleanup monies.
Estimated Outcomes of Selected Remedy
The expected condition after the selected remedy is implemented is that neither HRB, Warner's
Pond, HP-52 Ponds, nor the ORWBG will pose a surface exposure risk to industrial workers or
ecological receptors. No contaminants at HRB, Warner's Pond, or HP-52 Ponds will pose a
teachability risk that would result in groundwater contamination above MCLs in the UTRA
beneath the units. The teachability threat posed by waste at depth in the ORWBG will be
mitigated by the low permeability cap. The GSACU will be available for future industrial land
use with land use restrictions.
The selected remedy is considered a reasonable remedy to mitigate the GSACU risks; however,
there are always uncertainties. The primary uncertainties associated with the selected remedy
include the following:
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• There is uncertainty with the practicality of removing all soil containing CMCOCs to
levels at or below RGs, The fate and transport calculations performed for HRB, Warner's
Pond, and HP-52 Ponds were intentionally conservative. They do not, for example,
account for any dispersion or mixing in the aquifer. Consequently, the calculated RGs are
low and there is some uncertainty with how much the actual contaminant migration threat
is overstated. This uncertainty can be managed by performing a more detailed
contaminant migration assessment of any residual contamination that remains after
excavation. If modeling indicates that residual materials pose a continued teachability
threat, then an infiltration control system will be installed to protect groundwater quality.
Groundwater contamination is being handled under the HAGOU.
There is some uncertainty about the extent and continuity of the hardpan under HRB,
Warner's Pond, and HP-52 Ponds. The absence of unit-related groundwater
contamination at these units is evidence that the hardpan has served to limit the
downward migration of contamination. The remedy includes excavation of soil having
contaminants above RGs to the extent practical, but without compromising the integrity
of the hardpan. Contaminated soils in contact with perched water atop the hardpan will
be excavated as they are encountered. A soil cover is included as part of the remedy if
residual contamination poses a teachability risk. If the hardpan is found not to be present
or continuous, the remedy will remain unchanged. The soil cover will be designed to
meet the performance standard for permeability necessary to protect groundwater from
contaminant migration at levels that would exceed MCLs. This remedial goal is
independent of the natural limit to the downward migration of contaminants provided by
the hardpan.
• There are uncertainties with the groundwater modeling study which assessed the
teachability risk posed by the ORWBG. These uncertainties are a result of the absence of
analytical data from samples, limited information on the hydrogeologic conditions and
lithology under the unit, uncertainty with source term estimates, limited information on
some burial locations, and uncertainties inherent in any modeling effort. Any attempt to
further reduce these uncertainties would require intrusive sampling and investigation at
the ORWBG, which would pose unnecessary exposure risks to the workers involved and
is not likely to resolve uncertainty due to the heterogeneous nature of the waste.
Uncertainty with the model is managed by selecting an infiltration control system
(geosynthetic cap) that will provide a high degree of infiltration control. Any remaining
uncertainty associated with the effect that past and future leaching through the ORWBG
will have on groundwater quality under the ORWBG is being managed by the corrective
action for groundwater.
• Because the large inventory of long-lived radionuclides in the ORWBG will require
controls in perpetuity, there is some uncertainty with the ability to maintain institutional
controls in the very long-term. This uncertainty is managed by the five-year review
requirement of the ROD, The ROD will be reviewed at least every five years to
determine whether the remedy still provides adequate protection of human health and the
environment. As another means of managing the uncertainty of very long-term
institutional controls, intruder barriers will be installed over the long-lived persistent
radioactive hot spots (hot spots HS-500-1 through HS-500-8) before institutional controls
are terminated at the ORWBG to deter inadvertent human intrusion.
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Savannah River Site Rev. 0
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• There is some uncertainty with the volume of contaminated soil that will need to be
removed to meet RAOs, and consequently there is some uncertainty whether there is
sufficient available space at the ORWBG to accommodate al 1 the material. Based on
available data, the amount of soil from HRB, Warner's Pond, and HP-52 Ponds to be
placed at the ORWBG is estimated at 33,000 cy (excavation volume increased by 25%
due to handling). Based on three-dimensional modeling, the amount of available space at
the ORWBG to place waste under a cap is estimated at 60,000 cy, reflecting a reduction
of the available space by 30% to accommodate placement of clean soil berms and covers
around contaminated materials during construction. Because the estimated volume of
waste generated is only about half of the available volume at the ORWBG, there is little
uncertainty that there is enough space at the ORWBG. Any remaining uncertainty is
managed by the selected remedy, which includes a provision to send the excess volume
to an off-SRS disposal facility in the event that there is insufficient space at the ORWBG.
Waste Management
Waste generated during remediation will consist of approximately 33,000 cy of soil mixed with
some debris, including pipelines and vegetation. In addition, job control wastes such as
decontamination Quids and personal protective equipment will be generated. These will be
managed on-unit and consolidated at the ORWBG. Vegetation will be shredded, chipped, or
spatially distributed and incorporated into the excavated soil. Placement of this material at
ORWBG will be engineered in a manner that minimizes subsidence. Free liquids will not be
consolidated at the ORWBG. Waste liquids, including standing surface water in the HRB basin,
will be mixed with solids prior to consolidation at the ORWBG. All wastes generated will be
dispositioned in accordance with a site-specific waste management plan.
XII. STATUTORY DETERMINATIONS
Based on the unit RFI/RI data, the GSACU poses a threat to human health and the environment.
Therefore, Alternative 7 (Consolidation at the ORWBG) has been selected as the remedy for
HRB, Warner's Pond, and HP-52 Ponds and Alternative ORWBG VI (Institutional Controls with
Low Permeability Cap) has been selected as the remedy for the ORWBG. Individual intruder
barriers wil 1 be installed over the long-lived persistent radioactive hot spots in the ORWBG
(HS-500-1 through HS-500-8) before institutional controls are terminated at the ORWBG. The
options of in situ stabilization of HS-Hg-1 and removal of the radioactive hot spots in the
ORWBG will not be implemented.
PTSM is present at HRB, Warner's Pond, HP-52 Ponds, and ORWBG. At HRB, Warner's Pond,
and HP-52 Ponds, PTSM (and soil containing CMCOCs) will be removed to the extent
practicable. At the ORWBG, treatment or removal of the PTSM is not practicable; consequently,
engineering controls, such as containment through capping, will be used to manage the PTSM.
Based on information currently available, USDOE, USEPA, and SCDHEC believe the selected
remedy provides the best balance of tradeoffs among the other alternatives with respect to The
evaluation criteria. The three parties expect the selected remedy to satisfy the statutory
requirements in CERCLA Section 121(b) to (1) be protective of human health and the
environment, (2) comply with ARARs, (3) be cost-effective, (4) utilize permanent solutions and
alternative treatment technologies or resource recovery technologies to the maximum extent
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Savannah River Site Rev. 0
August 2002 Page 76 of 79
practicable, and (5) satisfy the preference for treatment (through removal) as a principal element
at HRB, Warner's Pond, and HP-52 Ponds. For the ORWBG, treatment of the principal threats
including the radioactive hot spots and HS-Hg-1 is not practicable. However, use of engineering
controls (such as containment through capping) combined with institutional controls is protective
of human health and the environment and is consistent with expectations in the NCP.
Section 300.430(f)(2) of the NCP requires that a 5-year remedy review of the ROD be performed
if hazardous substances, pollutants, or contaminants above levels that allow for unlimited use
and unrestricted exposure remain in the OU. The three parties, SCDHEC, USEPA, and USDOE,
have determined that a 5-year review of the ROD for the GSACU will be performed to ensure
that the remedy continues to provide adequate protection of human health and the environment.
XIII. EXPLANATION OF SIGNIFICANT CHANGES
There were no significant changes made to the ROD based on the comments received during the
public comment period for the SB/PP. Comments that were received during the public comment
period are addressed in the Responsiveness Summary included in Appendix A of this document.
XIV. RESPONSIVENESS SUMMARY
The Responsiveness Summary is included as Appendix A of this document.
XV. POST-ROD DOCUMENT SCHEDULE AND DESCRIPTION
Table 8 is an implementation schedule for the GSACU showing the post-ROD document
submittals and the remedial action start date. Major milestones are as follows:
SRS will submit a CIP to SCDHEC and USEPA in accordance with FFA requirements.
• The remedial action start date is anticipated to be March 2004.
Construction is anticipated to be completed approximately 3-4 years after the remedial
action start date.
• SRS will submit a post-construction report 90 days after construction is complete (i.e.,
after completion of a post-construction walkdown and acceptance by the core team
[USDOE, USEPA, and SCDHEC]).
-------
Table 8. Implementation Schedule
Activity
Oriii Eatly
Hllr *^:-r1
LCS 14- STATEMENT OF BASIS/PROPOSED PLAN & ROD
Piuuu«*l Plan
PV scoping meeting & GMSFS comment resolution 0
ueve'op Proposed Pi»n
Suboiil Rev. 0 Proposed Plwi
E.tly
Finish
28NOVOI'
59 S9NQVO 1 25F6B02
0
£(-' V3CDHEC rtvlsw of FI8V n Pronoftatl Plan 45 2SFEB02
25FEB02
1 IAPR02
1 EPA/SCDHCC rsuma nev o comments on PP o HAPR02
i'SRS incorporates LPA/SCUHEC comments PF 30 I?APRO?
Proposed Plan comment resolution me
*tmq 0 ?9APRO?
SRS suDminal of Hevi Proposed Plan 0
11 MAYO?
UMAVfJ?
EPA/SCDI ILC rirml review and spprovnl PP 30 I2MAYQ2 IOJUNOS
Receipt at LPA/SCDHEC approval
, Notification of public comment
! Pjblic cornnam period
• Develop Rno
Surjinn =ifiv n ROD
. FPA/SCOHEC review ol Bov 0 ROD
0
14 I1JJH02
•15 25JUN02
IOJUM02
24JUN02
06AUG02
70 24MAV02 033EPC2
0
4S 043EP02
FPA/fiCOHEC returns Rev. 0 cDrmrenlB fm ROD 0
RRS Hcorporales EPA/SCDHEC uornmenls ROD 30 ISOCTO!
ROD comment resolution mealing
CI7S 11 hmlllal of Rev l ROD
03SEPC2
13OCTD2
I8OCT02
I7NCV02
0 04NOVOZ
0
17NOVOS
•EPA/SCQHEC final review and approval of ROD 30 18NOV02 17D£C02
Submit signad ROD lo EPA/SCDHEC
0
LCS IS - DETAILED ENG & PRECONST ACTIVITIES
Dnvplop Rav. 0 CMI/RAIP (Posl-RaU Dotui|i«iil) 164 15JAN03
SRS surrmKlal of Rav. 0 CMI/RAIP 0
EPA/SC3HEC review of Rav. 0 CMI/RAIP SO C9SEP03
FPWSCDHEC return;! Rev. 0 comments lui CMKRA:P 0
31CEC02
OBSEF03
08SEP03
07CEC03
07CEC03
SRS Incorporates EPA/SCDHEC uoriwiantt CMI/'RAIP 60 OBD6CD3 OOI-bH(J4
SRS subinitlal or Rev.1 CMI/RAIP
Q
EPA/SCDHEC nnal rscje* and aoprc.va of CMI/RAIP 30 06FFWM
Submil sigried CMI/HAIP to CPA/SCDHCC ?•'
LCS 16 - CONSTRUCTION
Mimuntion
RA Start
Start Datfi 01OCT92
-mid i Dale 29MAH04
Data Date 01OCT9S
R'jnDiato 13FEBOZ 14:14
C Prrnnvcsra Systern;;. In*;.
05FEB04
DftMARCI
OSMARC4
77 C8DEC33 29MAHC4
PVtt
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XVI. REFERENCES
FF A, 1993. Federal Facility Agreement for the Savannah River Site, Administrative Docket No.
89-05-FF, WSRC-OS-94-42, Effective Date: August 16; 1993.
USDOE, 1994. Public Involvement, A Plan for Savannah River Site, United States Department
of Energy, Savannah River Operations Office, Aiken, South Carolina.
Johnston, J.D. (USEPA-Region IV), 1998. EPA Region IVPolicy, Assuring Land Use Controls
at Federal Facilities, Letter to T. Heenan (USDOE-Savannah River) (April 21).
USDOE, 1994. Public Involvement, A Plan for Savannah River Site, United. States Department
of Energy, Savannah River Operations Office, Aiken, South Carolina.
USDOE, 1996. Savannah River Site: Future Use Project Report, Stockholder Recommendations
for SRS Land and Facilities. January 1996. Cover letter: Fiori, Mario P., "SRS Future Use
Project Report (Reference.". Transmittal of Final Draft "Forging the. Missing Link: A Resource
Document for Identifying Future Use Options," Grumbly/Pearlman letter, 1-12-94)", United
States Department of Energy Letter EB-96-015, Savannah River Site, Aiken, South Carolina
29808 (January 29).
USDOE, 2002. Environmental Impact Assessment, Remediation of the General Separations Area
Consolidation Unit at the Savannah River Site, DOE/EIA-0001, United States Department of
Energy, Aiken, South Carolina
WSRC, 1995. RCRA Part B Permit Renewal Application for the Mixed Waste Management
Facility, WSRC-IM-91-53, vol.7, Mixed Waste Management Facility Postclosure, Westinghouse
Savannah River Company, Aiken, South Carolina.
WSRC, 1996. Interim Record of Decision Remedial Alternative Selection Old Radioactive Waste
Burial Ground (643-E) Savannah River Site, WSRC-RP-96-102, Westinghouse Savannah River
Company, Aiken South Carolina.
WSRC, 1997a. RFI/RI Work Plan Addendum for the H-Area Retention Basin Operable Unit
(281-3H), WSRC-RP-97-146, Rev, 1.5, Westinghouse Savannah River Company, Savannah
River Site, Aiken, South Carolina.
WSRC, 1997b. Workplan/RCRA Facility Investigation/Remedial Investigation Report for the
Old Radioactive Waste Burial Ground 643-E, S01-S22, Savannah River Site, Vol. I,
WSRC-RP-97-00127, Westinghouse Savannah River Company, Aiken, South Carolina.
WSRC, 1997c. Source Term for the Old Radioactive Waste Burial Ground (ORWBG), Savannah
River Site, WSRC-RP-97-0119, Westinghouse Savannah River Company, Aiken, South
Carolina.
WSRC, 1997d. Summary of Water Table Monitoring for the Old Radioactive Waste Burial
Ground (ORWBG), WSRC-RP-97-00330, Westinghouse Savannah River Company, Aiken,
South Carolina.
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WSRC, 1997e. Delineation of Potential "Hot Spots" for the Old Radioactive Waste Burial
Ground (ORWBG), WSRC-TR-97-00329, Rev. 0, Westinghouse Savannah River Company,
Aiken, South Carolina.
WSRC, 1997f. Savannah River Site NEPA/CERCLA Integration Guidance, WSRC-RP-97-232,
Westinghouse Savannah River Company, Aiken, South Carolina.
WSRC, 1998. RCRA Facility Investigation/Remedial Investigation Report with Baseline Risk
Assessment for the H-Area Retention Basin (281-3H), WSRC-RP-98-4136, Rev. 1.1,
Westinghouse Savannah River Company, Savannah River Site, Aiken, South Carolina.
WSRC, 1999. Land Use Control Assurance Plan for the Savannah River Site.,
WSRC-RP-98-4125, Rev. 1.1, Westinghouse Savannah River Company, Savannah River Site,
Aiken, South Carolina.
WSRC, 2000a. Focused Corrective Measures Study/Feasibility Study for the H-Area Retention
Basin (281-3H), WSRC-RP-2000-4110, Rev. 0, Westinghouse Savannah River Company,
Savannah River Site, Aiken, South Carolina.
WSRC, 2000b. Addendum to the Workplan/RCRA Facility Investigation/Remedial Investigation
Report for the Old Radioactive Waste Burial Ground, 643-E, S01-S22, WSRC-RP-99-4023,
Westinghouse Savannah River Company, Aiken, South Carolina
WSRC, 2000c. Interim Record of Decision for the Old Solvent Tanks at the Old Radioactive
Waste Burial Ground, WSRC-RP-2000-4193, Rev. 1, Westinghouse Savannah River Company,
Savannah River Site, Aiken, South Carolina.
WSRC, 200 la. RCRA Facility Investigation/Remedial Investigation Work Plan for Warner's
Pond and HP-52 Ponds Operable Units, WSRC-RP-2001-4048, Rev. 0, Westinghouse Savannah
River Company, Savannah River Site, Aiken, South Carolina.
WSRC, 2001b. Corrective Measures Study/Feasibility Study for the Old Radioactive Waste
Burial Ground, 643-E, WSRC-RP-98-4012, Rev. 1.1, Westinghouse Savannah River Company,
Savannah River Site, Aiken, South Carolina.
WSRC, 2002. Statement of Basis/Proposed Plan for the General Separations Area
Consolidation Unit, WSRC-RP-2001-4267, Rev. 1, Westinghouse Savannah River Company,
Aiken, South Carolina.
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August 2002 PageAl of A2
APPENDIX A
RESPONSIVENESS SUMMARY
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RESPONSIVENESS SUMMARY
The 45-day public comment period for the SB/PP for the GSACU began on June 6, 2002, and
ended on July 20, 2002. Comments and responses are provided below.
Public Comments
COMMENT #1: SRS received one oral comment from a member of the public who inquired
about how the expected soil excavation volumes were calculated.
JAESPONSE: The expected soil excavation volumes were calculated by multiplying the lateral
extent of contamination by the expected depth of contamination. Where data were incomplete or
estimated, or where the extent or depth of contamination were unknown, appropriate
contingencies were included.
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Savannah River Site Rev. 0
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APPENDIX B
COST ESTIMATES
FOR
THE SELECTED REMEDY
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Savannah River Site
August 2002
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Rev.O
PageB3ofB20
Appendix B-l. Cost Estimate for Selected Remedy for HRB,
Warner's Pond, and HP-52 Ponds - Capital Cost Summary
Alternative: 7
Name: Waste Consolidation at the ORWBG
Base Year: 2000
Date: November 1 , 2000
Description
Unit
Quantity
Unit Cost
Item
Total
REMEDIAL DESIGN PHASE - HRB
Preliminary Engineering
Detailed Engineering and Pre-Construction
Project Support
Subtotal Remedial Design Phase
$30,467
$353,726
$149,150
Activity
Total
$533,343
$533,343
REMEDIAL ACTION PHASE - HUB
1
2
3
4
S
Pre-Construction Maintenance
Grass/Brush Cutting
Apply Herbicide and Insecticide
SRS Oversight
Subcontract Technical Requirements
Subcontractor Mobilization
Flatbed Truck
Pickup
Dump Truck
Truck w/ Water Tank
Tool Van
Dozer
From End Loader
Motor Grader
Hyd Excavator/Backhoe
Tractor
Hydromulcher
Trencher
Crane
Sheepsfoot Roller
Vibratory Drum Roller
Miscellaneous Small Equipment
Assembly of Equipment
Set-up 3 Consouction Trailers
Temporary Security Fence
Temporary Utilities
AC
AC
HR
EA
BA
EA
EA
EA
EA
EA
EA
EA
EA
EA
EA
EA
EA
EA
LS
DAY
HR
LF
LS
16
16
480
3
2
16
1
2
4
2
2
4
2
1
1
2
2
2
I
8
120
1,400
1
$530.64
$254.90
$50.65
$594.82
$594.83
5594.83
$594.83
$594.83
$1,189.65
$1,189.65
$1,189.65
$1,189.65
$1,189.65
$1,189,65
$1,189.65
$1,189.65
SI ,189.65
$1,189.65
$2379,00
$2,623.97
$27.01
$12.55
$8,149.00
$8,490
$4,078
$24.312
$579,915
$1,784
$1,190
$9,517
$595
$1,190
$4,759
$2,379
$2,379
$4,759
$2,379
$1,190
$1,190
$2.379
$2.379
$2.379
$2,379
$20,992
$3,241
$17.570
$8,149
$36,880
$579,915
$67,060
$17,570
$8,149
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Rev. 0
PageB4ofB20
Appendix B-l. Cost Estimate for Selected Remedy for HRB.
Warner's Pond, and HP-52 Ponds - Capital Cost Summary (Continued)
Description
6 General Site Work
Grass/Brush Cutting
Apply Pesticide
Disc Material
7 Erosion Control
Install and Remove Silt Fence
install and Remove Hay Bales
Lnsp,/MainL/Rep./C!ean Erosion Cntrl Fac,
8 Prepare Borrow Area
Clearing w/ Dozer
Grab and Remove Stumps
Excavating, bulk w/ Dozer
Load for Hauling
Haul to Stockpile
9 Geophysical/Geotechnical Investigation
Skilled Samplers
Soil Panicle Size Analysis
Moisture Content
Liquid Limit, Plastic Limit, Plasticity Index
Lab Compaction ASTM D698
Transportation to Lab
10 Excavation at Basin
Excavate Place in Lift Liners
Pipe Removal
Load Lift Liners on Flatbed Truck
Haul Lift Liners to Burial Ground
Unload Liners at Burial Ground
Dump Liners at Burial Ground
Purchase Lift Liner
Purchase Lifting Frame
Purchase Loading Frame
11 Backfill Excavated Areas/Berm
Load Backfill at Borrow Pit
Haul Material from Borrow Pit
Spread Material for Compaction
Compaction
Rough Grade and Scarify
Cut and Regrade
12 Site Surveys
Topography Pre-Construction
Topography Basin Pre-Construction
Topography Basin Low Perm Soil
Topography As Built
Survey Monuments
Unit
AC
AC
SY
LF
LF
HR
AC
AC
CY
CY
CY
HR
EA
EA
EA
EA
Trip
CY
LF
EA
EA
EA
EA
EA
EA
EA
CY
CY
CY
CY
MSF
CY
AC
AC
AC
AC
EA
Quantity
1.5
1.5
7,300
300
300
210
1.1
1.1
1,800
2,200
2,200
.58
29
29
29
29
3
10,165
160
1,470
1,470
1,470
1,470
1,470
2
2
10,800
13,000
10,800
10,800
500
1,880
3
1.5
1.5
3
4
Unit Cost
$908.79
$404.83
$0.11
SI. 13
$10.67
$46.95
$1,542.90
$1,369.80
$1.54
$1.20
$3.75
$26.45
SI 1 8.96
SI 0.71
$63.06
$157.04
$446.12
$14,54
S17.58
$98.17
$54.60
$61.36
$251.72
$450.00
$6,605.39
$4,611.31
$2.63
$13.80
$2.46
$1.32
$30.86
$5.41
$1,691.34
$2,673.00
$1,691,00
$1,691.34
$104.74
Item
Total
$1,363
$607
$792
$340
$3,202
$9,860
$1,697
$1,507
$2,765
$2,641
$8,243
$1,534
$3,450
$310
$1,829
$4,554
$1,338
$147,758
$2,813
$144,310
$80,261
$90,193
$370,034
$661,500
$13,211
$9,223
$28,357
$179,460
$26,540
$14,243
$15,429
$10,164
$5,074
$4,010
$2,537
$5,074
$419
Activity
Total
$2,762
$13,402
$16,853
$13,015
Sl.519,303
$274,193
$29,31 1
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PageB5ofB20
Appendix B-l. Cost Estimate for Selected Remedy for HUB,
Warner's Pond, and HP-52 Ponds - Capital Cost Summary (Continued)
13
14
IS
16
17
18
19
20
21
22
Description
SC Surveyor
As Built Drawings
Closed Basin Marker
Dust Suppression
Wind Barrier
Construction Water and Facilities
Geophysical/Geotechnieal Investigation
Nuclear Density/Sand-Cone Density
Nuclear Density
25% Reiesting
Sampling and Analysis
Site Restoration Fine Grading
Soil/Vegetative Cover
Load Fill Material at Borrow Pit
Haul Material from Borrow Pit
Spread Common Fill
Compaction
Rough Grade and Scarify
Obtain Top Soil Off-Site
Spread Top Soil
Scarify Top Soil
Water Top Soil Mix
Proof Roll Top Soil Mix
Site Seeding
Spread Lime with Tractor
Seeding Hydro/ Air Seeding w/ Mulch/Fert.
Follow-up Fertilizer w/ Tractor
Water Seeded Area
Maintenance Seeding
Permanent Fencing
Demobilization Construction Equipment
Flat Bed Truck
Pickup
Dump Truck
Truck w/ Water Tank
Tool Van
Dozer
Front End Loader
Motor Grader
Hyd Excavator/Backhoe
Tractor
Hydrornulcher
Trencher
Crane
Unit
HR
HR
EA
HR
LF
HR
HR
LS
SY
CY
CY
CY
CY
MSF
CY
CY
SY
DAY
CY
MSF
MSF
MSF
DAY
MSF
LF
EA
EA
EA
EA
EA
EA
EA
EA
EA
EA
EA
EA
EA
Quantity
70
120
4
420
200
200
660
1
14,500
10,200
12,200
10,200
10,200
441
1,300
1,300
7,000
1
3,300
131
131
131
2
27
1,060
3
2
16
1
2
4
2
2
4
2
i
1
2
Unit Cost
$66.18
$56.18
$205.45
$49.82
$31,19
S76.14
S76.14
517,000,00
$0.58
$3.03
$13.80
$1.54
$0.45
$19.29
$35,69
$1.52
$0.20
$889.00
$0,62
$9.84
$54.19
$4.36
$889.24
$54,19
$30.00
$594.82
$594.83
$594,83
$595.00
$594.83
$1,189.65
$1,189.65
$1,189.65
$1,189.65
$1,189.65
$1,189.65
$1,189.65
$1,189.65
Item
Total
$4,633
$6.742
$822
$20,924
$6,238
524,351
$15,228
$50,250
$17,000
$203,415
$8,464
$30,901
$168,416
$15,665
$4,570
$8,505
$46,397
$1,973
$1,426
$889
$803
$1,290
$7,098
$57!
$1,778
$1,463
531,800
$1,784
$1.190
$9,517
$595
$1,190
$4,759
$2,379
$2,379
$4,759
52,379
$1,190
$1,190
$2,379
Activity
Total
$20,924
$6,238
$24,351
$82,478
$203,415
$8,464
$279,545
$12,200
$31,800
$61,812
-------
ROD for the GSACU (U)
Savannah River Site
August 2002
WSRC-RP-2002-4Q02
Rev. 0
PageB6ofB20
Appendix B-l. Cost Estimate for Selected Remedy for HRB,
Warner's Pond, and HP-S2 Ponds - Capital Cost Summary (Continued)
23
24
25
26
27
28
29
30
31
32
33
34
35
Description
Sheepsfoot Roller
Vibratory Drum Roller
Miscellaneous Small Equipment
Disassembly of Equipment
Removal Three Construction Trailers
Remove Temporary Security Fence
Remove Temporary Utilities
Remove Temporary Water and Sewer
Remove Temporary Service
Remove Temporary Power
Equipment Decontamination
Construct Decon Pad
Decon Equipment
Remove Decon Pad
Construction Equipment
Final Acceptance
Rad Screens
Transport to Lab
Rad Screen
Construction Management and Engineering
Project Support for Construction
Remediation Derived Waste
Solid (Lift Liner) Container! zation
Solid (Lift Liner) Characterization
Waste Stream Sampling
Waste Stream Sample Analysis
Rad Field Screen
Waste Program Support
RCO Support
ERE Exeropt Support
Waste Program Support
ERE Exempt Support (Documentation)
Waste Program Support (Manifest)
Lift Liner Transporting
Container Loading
RCO Support
Post Construction
Final Safety Inspection
Post Construction Report
Final Remediation Report
Geotech Labor
Project Support for Post Construction
Project Support During Remedial Action Phase
Unit
EA
EA
LS
DAY
HR
LF
LS
LS
LS
SF
HR
SF
LS
LS
EA
EA
LS
EA
EA
EA
EA
EA
EA
EA
EA
EA
EA
LS
HR
HR
HR
HR
Quantity
2
2
1
6
120
1,400
1
1
1
864
500
864
1
I
70
70
1
1
1
1
1
1
1
1
1
1
1,470
1,470
80
150
200
200
Unit Cost
$1,189.65
$1,189.65
$2,379.00
$2,623.97
$27.01
$2.91
$714.00
$714,00
$714.00
$13.06
$33.24
$5.69
$59,483.00
$6,000.00
$188.42
$258.20
$53.00
$1,200.00
$2,460.00
$366.00
$317.00
$304.00
$263.00
$528.00
$2,632.00
$633.00
$211.00
$151.95
$65.79
$65.79
$65.79
$63.38
Item
Total
$2,379
$2.379
$2,379
115,744
S3.241
$4,073
$714
$714
$714
$11,281
$16,619
$4,914
$59,483
$6,000
$13,189
$18,074
$119,501
$101,436
$53
$1,200
$2,460
$366
$317
$304
$263
$528
$2,632
$633
$310,170
5223,367
$5,263
$9,869
$13,158
$12,676
$13,147
$117,984
Activity
Total
$4,073
$2,142
$92397
$6,000
$31,263
$119,501
$101,436
$53
$8,703
$533,537
$40,966
$13,147
$117,984
-------
ROD for the GSACU (U)
Savannah River Site
August 2002
WSRC-RP-2002-4002
Rev.O
PageB7ofB20
Appendix B-l. Cost Estimate for Selected Remedy for HRB,
Warner's Pond, and HP-52 Ponds - Capital Cost Summary (Continued)
Description
Unit Quantity
Unit Cost
Item
Total
Activity
Total
Subtotal Remedial Action Phase - HRB
Subtotal Remedial Design & Action Phase - HRB
Surcharge
Subtotal
ESS
G&A
Contingency
TOTAL CAPITAL COST - HRB
3,50%
14.45%
J7.16%
20.00%
S2,663,506
$93,223
$4380,742
~$4,914,085
593,223
$5,007,308
$723.556
$983,416
$1,342,856
$8,057,136
The capital cost estimate was initially developed in the HRB CMS/FS based on a contaminated soil volume of
10,165 cy. The volume estimate was subsequently revised to 12,150 cy. The capital cost estimate was scaled
using the ratio of the revised volume to the initial volume; i.e., increased by a factor of 1.195 (12,150/10,165).
ADJUSTED TOTAL CAPITAL COST - HRB
$9,630,517
Cost estimates for Warner's Pond and HP-52 Ponds were determined by scaling the HRB cost estimate using the
ratio of the volume of contaminated soil at HRB to the volume of contaminated soil at Warner's Pond and HP-52
Ponds. Results are presented in Table 6 of the ROD.
-------
ROD for the GSACU (U)
Savannah River Site
August 2002
WSRC-RP-2002-4002
Rev.O
PageBSofBlO
Appendix B-2. Cost Estimate for Selected Remedy for HRB,
Warner's Pond, and HP-52 Ponds - Summary of Present Value Analysis
Alternative: 7
Name: Waste Consolidation al the ORWBC
Base Year; 2KB
Dale: Nowmbei 1,2000
[merest Rae: 3.99
Years
Annuity Factor
S
4.46
Unit Dollars/ Annual
ANNUAL COSTS - HRB
Post-Closure
Collection of Samples (1 3 wells twice/yr)
Collection of Trip Blanks (25%)
Collection of Splits 0/20)
Collection of Duplicates (1/20)
Analysis Trip Blanks
Antlysis Samples, Splits, Duplicates
EMS-EXR Data Management (Mobilization, V&V, Data Summary
Report, Data Management)
ER-FPC Field Char. Report
Annual Report
Monitoring Well Maintenance
Project Support for Well Monitoring and f nstiiutional Control
Preventive and Corrective Maintenance
Project Support (maintenance)
Project Support (O&M)
Project Support (PCS/LTM Phase)
Quantity
26
6.5
1,3
1,3
6.5
28.6
1.45
Unit
$100
$100
$100
$100
$100
$900
$5,000
Dollars
$2.600
$650
$130
$J30
$650
$25,740
$! 1,876
$5.000
$4,056
$14,937
$3,03?
$7,250
$6,341
$8,874
$8,959
Cost
SI 1,607
$2,902
$5SO
$580
$2,902
$114.913
$53,016
$22,322
$18,109
$66,683
$13,558
$32,367
$28,307
$39,616
$39,996
Subtotal Annual Dollars
ESS
G&A
Contingency
Tata) NPV Annual Costs
PERIODIC COSTS • HRB
Land Survey
Well Aband.
D&R Monitoring Well Equipment
Grout Monitoring Wells
Subtotal - Non-discounted
Year
Subtotal - present value
ROD Reviews - present value
Total NPV Periodic Cosls - HRB
TOTAL O&M COSTS - (Annual + Periodic) - HRB
$100,229 $447,458
14.4J%
17.16%
20.00%
$14.483
$19,685
$26,879
$64,658
$87,879
$1)9,999
$719,994
Cost
$3.810
$25,102
$43,978
$26,670
$99.560
$82,226
$4,306
$86,332
$806,52*
The O&M cost estimate was initially developed In the HRB CMS/FS based on a contaminated soil
volume of 10,165 cy. The volume estimate was subsequently revised to 12,150 cy. The O&M cost
estimate was scaled using the ratio of the revised volume to the initial volume; i.e., increased by a
lactorotl.195 (12,160/10,165).
ADJUSTED TOTAL O&M COST - HRB
$964,023
Cost estimates tor Warner's Pond and HP-S2 Ponds were determined by scaling the HRB cost
estimate using the ratio of the volume of contaminated soil at HRB to the volume of contaminated soil
at Warner1 s Pond and HP-5S Ponds. Results are presented in Table 6 of the ROD.
-------
ROD for the GSACU
-------
ROD for the GSACU (U)
Savannah River Site
August 2002
WSRC-RP-2002-4002
Rev.O
Page BIO of B20
Appendix B-3. Cost Estimate for Selected Remedy for the ORWBG -
Capital Cost Summary (Continued)
8
10
11
12
Description
Site Restoration
Rll Sediment Basin & Berms
Compact Sediment Basin
Remove Rip Rap @
Sediment Basin Spillway
Load Borrow for Fill for
Crave) Road and Drainage
Haul Fill for Gravel Road
and Drainage
Place Fill for Gravel Road
and Drainage
Grade Road and Shoulder
Compact Road
Furnish Gravel for Road
Place and Compact Gravel
Furnish Gravel for Ramps
Put&Comp Gravel/Ramps
F & 1 24" CMP Culvert
Vegetative Cover - seeding
Site Surveys
Survey
Survey Monuments
Miscellaneous Control Items
Furnish and Install Signs
Demobilization
Subtotal
ESS
G&A
Contingency
Quantity
18,489
18,489
167
1,937
1,937
1,937
31,294
31,294
4.024
23,843
194
1,192
238
76
1
30
30
1
14.45%
17,16%
20,00%
Unit
CY
CY
CY
CY
CY
CY
SY
SY
CY
SY
CY
SY
LF
AC
EA
LS
Unit Cost
$2.05
$0.71
$21.27
$0,43
$0.52
$1.06
$1.97
$2.12
$15.00
$0.42
$15.00
$0.42
$25.41
$1,000
$30,000
$175
$90
$25,000
Total
$37,846
$13,122
$3,553
$831
$1,014
$2,053
$61,743
$66,406
$60353
$10,119
$2,910
$506
$6,060
$76,000
$30,000
55,250
$2,700
$25,000
Total
$342,516
$35,250
$2,700
$25,000
$7,138,305
$1,031,485
$1,224,933
$1,427,661
TOTAL CAPITAL COST - ORWBG
$10^22384
-------
ROD for the GSACU (U)
Savannah River Site
August 2002
WSRC-RP-2002-4002
Rev. 0
PageBllofB20
Appendix B-4. Cost Estimate for Selected Remedy for the ORWBG
Summary of Present Value Analysis
Alternative: ORWBG VI
Name: Gtosynthetic "Low Permeability Cap
Base Yean 2000
Date: November 1. 2000
Interest Rate: 3.9%
Year
0
t
2
3
4
5
6
7
8
9
10
II
12
13
14
15
16
17
!8
19
20
2]
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
Annual O&M
Capital Cost Cost
• $1 0,822.384
i 17,510
$17,570
$17,570
$17,510
$27.570
$17470
$17,570
$17.570
$17,510
570,033
$17,570
$17,570
$17.570
$17,570
$27370
$17370
$17370
$17,570
$17,570
$70,033
$17,570
$17370
$17,570
$17370
$1,111,434
$17370
$17,570
$17,570
$17,570
$70,033
$17,570
SI7.570
$17,570
$17,570
• $27,570
SJ 7,570
$17370
$17370
$17370
$70,033
$17370
S17.570
$17,570
$17.570
$27,570
Total
Cost
$10.822,3*4
$17,570
$17,570
$17370
S 17,570
$27,570
$17,570
$17,570
$17370
$17,570
$70,033
Si 7,570
$17,570
S 17,570
$17,570
$27,570
$17,570
$17,570
$17,570
$17,570
$70,033
$17,570
$17,570
$17370
$17,570
$1.111,434
$17,570
$17370
$17370
S173TO
$70,033
$17,570
$17,570
$17,570
$17,570
$27,570
' $17,570
$17,570
$17.570
$17,570
$70,033
$17370
$17370
$17.570
$17,570
$27,570
Discount
Factor (3.9%)
LOGO
0.962
0.926
0.892
0.858
0.82S
0.795
0,765
0.736
0.709
0,682
0.656
0,632
0.608
0385
0363
0342
0.522
0,502
0.483
0.465
0.448
0.431
0.415
0.399
0.384
0,370
0.356
0.343
0,330
0.317
0,305
0.294
0.283
0.272
0.262
0.252
0.243
0.234
0.225
0,216
0.208
0.201
0.193
0.186
0.179
Present
Worth
$10.822,384
$16,910
$16.276
$15,665
$15,077
$22,770
$13,966
$13.442
$12.937
$12.452
$47,769
$11.535
$11,102
$10.685
$10,284
$15,531
$9,526
$9.169
$8,825
$8.493
$32,583
$7,868
$7,572
$7,288
$7,015
$427,066
$6,498
$6,254
$6,019
$5,793
$22,225
$5,366
$5,165
$4,97]
$4,785
$7,226
$4.432
$4.266
$4,106
$3,952
$15,159
53,660
$3,523
$3,391
$3,264
$4,929
-------
ROD for the GSACU (U)
Savannah River Site
August 2002
WSRC-RP-2002-4002
Rev.O
PageB12ofB20
Appendix B-4. Cost Estimate for
Selected Remedy for the
ORWBG-
Summary of Present Value Analysis (Continued)
Year
46
47
4B
49
SO
SI
52
S3
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
Annual O&M
Capital Cost Cost
$17.570
$17,570
$17.570
$17,570
$1,153,898
$17,570
$17,570
$17,570
$17.570
$27,570
$17,570
$17,570
$17,570
$17.570
$70,033
$17,570
$17,570
$17.570
$17370
$27,570
$17,570
$17,570
$17,570
$17,570
$70,033
$17,570
$17,570
$17,570
$17,570
$1,111,434
$17,570
$17,570
$17,570
$17,570
$70,033
$17,570
$17,570
$17,570
$17,570
$27,570
$17,570
$17,570
$17,570
$17,570
$70,033
$17,570
$17,570
517,570
$17,570
S27.S70
$17,570
$17.570
$17,570
$17,570
$1,153.898
Total
Cost
$17,570
$17,570
$17.570
$17,570
$1,153,898
$17,570
$17,570
$17,570
$17,570
$27,570
$17,570
$17,570
$17,570
$17370
$70,033
$17,570
$17,570
$17,570
$17,570
$27,570
$17,570
$17,570
$17,570
$17,570
$70.033
$17,570
$17,570
$17,570
$17,570
$1,111.434
$17370
$17,570
$17,570
$17370
$70,033
$17,570
$17370
$17370
$17370
$27370
$17370
$17370
$17370
$17370
$70,033
$17370
$17370
$17370
$17370
$27,570
$17370
$17370
$17,570
SI 7370
Si, 153,898
Discount
Factor (3.9%)
0.172
0.166
0.159
0.153
0.148
0.142
0.137
0.132
0.127
0.122
0.117
0.113
0.109
0.105
0.101
0.097
0.093
0.090
0.016
0.083
0.080
0.077
0.074
0.071
0,069
0.066
0.064
0.061
0,059
0.057
0.055
0.053
0.051
0.049
0,047
0.045
0,043
0.042
0.040
0.039
0.037
0.036
0.035
0.033
0.032
0.031
0.030
0.028
0.027
0.026
0.025
0.024
0.024
0.023
0,022
Present
Worth
$3,023
S2.910
$2,800
$2,695
$170,369
$2.497
$2,403
$2.313
$1226
$3,362
$2,062
$1,985
S1.9JO
$1,838
S7.0S3
S1.703
$1,639
$1.578
$U1S
$2,293
$1,407
$1,354
$1,303
$1,254
$4,8)1
$1,162
$UI8
$1,076
$1,036
$63,055
$959
$923
$889
$855
$3,281
S792
$763
$734
$706
$1.067
$654
$630
$606
$583
$2,238
S540
$520
$501
$482
$728
$446
$430
$413
$398
$25,154
-------
ROD for the GSACU (U)
Savannah River Site
August 2002
WSRC-RP-2002-4002
Rev.O
PageB13ofB20
Appendix B-4. Cost Estimate for
Selected Remedy for the
ORWBG-
Summary of Present Value Analysis (Continued)
Year
101
102
103
104
105
106
107
108
109
HO
11!
112
113
JI4
115
116
11?
JJ8
119
120
121
122
123
124
125
126
127
128
329
330
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
14?
148
149
150
151
152
153
154
15J
Annual O&M
Capital Cost Cost
$17,570
$17.570
$17,570
$17,570
527,570
$17,570
$17,570
$17,570
$17,570
$27,570
$17.570
$17,370
$17.570
$17.570
$27,570
$17,570
$17,570
$J7,570
$17,570
$70.033
$17,570
$17,570
$17370
$17470
$27,570
$17.570
$17.570
$17370
$17,310
S27.570
$17,570
$17370
$17,570
$17,570
$27,570
$17370
$17370
$17370
$17370
$70,033
$17.570
$17370
$17370
$17.570
$27.570
SI 7,570
$17370
$17370
$17370
$27,570
$17370
$17370
$17370
$17,570
$27370
Total
Cost
$17370
SI7J70
$17370
SI737Q
S27.57Q
$17,570
$17,570
$17.570
$17370
$27.570
$17,570
$17.570
S 17370
$17,570
S27.570
$17,570
$17,570
$17,570
$17,570
$70,033
$17370
JJ7370
$17,570
$17,570
$27,570
$17370
$17370
$17370
$17370
$27370
$17370
$17370
$17,570
$37370
$27,570
$17,570
$17,570
$17370
$17,570
$70,033
$17.570
$17,570
$17370
$17370
$27370
$17370
$17.570
$17.570
$17,570
$27.570
$17,570
$17370
$17370
$17370
$27,570
Discount
Factor (3.9%)
0.021
0.020
0.019
0.019
0.018
0.017
0.017
0,016
0.01S
0.015
0.014
0.014
0,013
O.OJ3
0.012
0.012
0.011
0.011
0.011
0.030
0.010
0,009
0.009
0.009
0.008
0.008
0.008
0,007
0.007
0.007
0,007
0.006
0.006
0.005
0,006
0.005
0.005
0.005
0.005
0.005
0.005
0.004
0.004
0.004
0.004
0.004
0.004
0.003
0.003
0.003
0.003
0.003
0.003
0.003
0.003
Present
Worth
$369
J315
$341
$329
$496
1304
$293
$282
$271
$410
$251
$242
$233
$224
$339
$208
$200
$J92
$185
$710
$172
$165
$159
$153
$231
$142
$136
$131
$126
$191
$117
$113
$108
$104
$158
$97
$93
$90
$86
$330
$80
$77
$74
$71
$107
$66
$63
$61
$59
$89
$54
$52
$50
$49
$73
-------
ROD for the GSACU (U)
Savannah River Site
August 2002
WSRC-RP-2002-4002
Rev. 0
PageB14ofB20
Appendix B-4. Cost Estimate for Selected Remedy tor the ORWBG -
Summary of Present Value Analysis (Continued)
Year
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
17!
172
173
174
175
176
177
178
179
180
m
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
19?
198
199
200
201
202
203
204
205
206
207
208
209
210
Annual O&M
Capital Cost Cost
$17,570
$17,570
$17,570
$17,570
$70,033
$17,570
$17370
$17,570
$17,370
$27,5?0
$17,570
$17,570
$17,570
$17,570
$27,570
$17,570
$17,570
$17.570
$17,570
$27,570
$17370
$17,570
$17,570
$17,570
$70,033
$17,570
$17,570
$17,570
$17,570
$27,570
$17,570
$17,570
$17,570
$17,570
$27,570
$17,570
$17,570
$17,570
$17,570
$27370
$17370
$17,570
$17370
$17370
$70.033
$17370
$17370
$17370
$17370
$27370
$17370
$17370
$17.570
$17370
$27370
Total
Cost
$17,570
$17.570
$17370
$17,570
$70,033
$17,570
$17,570
$17,570
$17.570
$27,570
$17,570
$17,570
S17.S70
$17,570
$27370
$17370
$17,570
$17,570
$17,570
$27,570
$17370
$17370
$17,570
$17,570
$70,033
$17370
$17,570
$17,570
$17,570
$27370
SI 7,570
$17,570
$17,570
$17.570
$27.570
$17.570
$17,570
$17.570
$17.570
$27,570
$17.570
$17370
$17,570
$17.570
$70.033
$17,570
$17370
$17,570
$17370
$27370
$17370
$17.570
$17370
$17370
$27370
Discount
Factor (35%)
0,003
0,002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.000
0.000
0,000
0.000
0.000
0.000
0,000
0.000
0.000
0.000
0.000
0.000
Present
Worth
$45
$43
$42
$40
$154
$37
$36
$34
$33
$50
$31
$30
$28
S27
$41
$25
$24
$23
$23
$34
$21
$20
$19
$19
$72
$17
$17
$16
$15
$23
$14
$14
$13
$13
$19
$12
$1!
$11
$11
$16
$10
$9
$9
$9
$33
$8
$8
$7
$7
$11
$7
$6
$6
$6
$9
-------
ROD for the GSACU (U)
Savannah River Site
August 2002
WSRC-RP-2002-4002
Rev. 0
PageB15ofB20
Appendix B-4. Cost Estimate for
Selected Remedy for the
ORWBG -
Summary of Present Value Analysis (Continued)
Year
21)
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
25?
258
259
260
261
262
263
264
265
Annual O&M
Capital Cost Cost
$17,570
Sf7,S7Q
$17,570
$17,570
$27370
$17,570
$17,570
$17,570
$17,570
$70,033
$17,570
$17.570
$17,570
$17,570
$27,570
$17,570
$17,570
$17,570
$17.570
$27.570
$17,570
SI 7,570
$17,570
$17.570
$27,570
$17.570
$17.570
$17.570
$17470
$70,033
$17,570
$17470
JI7370
$17370
$27370
$17,570
$17,570
$17,570
$17,570
$27,570
$17370
$17370
$17470
$17.570
$27,570
$17,570
$17,570
$17,570
$17,570
$70.033
$17470
$17470
$17,570
$17,570
$27,570
Total
Cos!
$17,570
$17.570
$17.570
$17370
$27370
$17,570
$17,570
$17,570
$17,570
$70.033
$17370
$17,570
$17,570
SI7.570
$27,570
$17370
$17,570
$17370
$17470
$27470
$17,570
$17.570
$17470
$17370
$27,570
$17370
$17,570
$17470
$17370
$70,033
$17,570
$17370
$17370
$17370
$27.570
$17,370
$17,570
$17.570
$17,570
$27,570
$17370
SI 7.570
$17,570
$17.570
$27,570
$17.570
$17,570
$17370
$17370
$70.033
$17,570
$17,570
$17,570
$17,570
$27.570
Discount
Factor (3.9%}
0.000
0.000
0.000
0.000
0.000
0.000
0,000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
O.QOO
0,000
0,000
0.000
0.000
0.000
0.000
0.000
0,000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
Present
Worth
$5
$5
$5
$5
$7
$5
$4
$4
$4
$15
$4
$4
$3
$1
$5
$3
$3
$3
$3
$4
$3
$2
$2
K
$3
$2
$2
$2
$2
$7
$2
$2
$2
$2
$2
$1
$1
$!
$1
$2
$1
$1
$1
$1
$2
$1
SI
SI
s\
$3
$1
SI
$1
$1
$1
-------
ROD for the GSACU (U)
Savannah River Site
August 2002
WSRC-RP-2002^002
Rev. 0
PageB16ofB20
Appendix B-4. Cost Estimate for
Selected Remedy for the
ORWBG -
Summary of Present Value Analysis (Continued)
Year
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
Annual O&M
Capita! Cost Cost
$17370
$17.570
$17,570
$17,570
$27370
$17.570
$17.570
$17,570
$17.570
$27.570
$17,570
$17370
$17,570
$17.570
$70,033
$17.570
$17,570
$17370
$17,570
$27370
$17,570
$17370
$17370
$17370
S27370
$17370
$17,570
$17,570
$17,570
$27,570
$17,570
$17,570
$17,570
$17370
$70,033
$5370
$5,570
$5,570
$3.570
$21,270
$5,570
$5,570
$5370
$5,570
$21,270
$5370
$5370
$5,570
$5,570
$21.270
$5,570
$5370
$5370
$5,570
$21.270
Tola!
Co*t
$17,570
$17370
$17370
$17370
$27370
$17370
$17370
$17370
$17370
$27370
$17370
$17,570
$17370
$17,570
$70,033
$] 7,570
$17,570
$17,570
$17,570
$27370
$17370
$17370
$17370
$17370
$27370
$17,570
$17,570
$17.570
$17370
$27,570
$17,570
$17,570
$17,570
$17370
$70,033
S5.570
$5370
$5370
$5,570
$21.270
$5370
$5,570
$5,570
$5370
$21,270
$5370
$5370
$5370
$5,570
$21,270
$5.570
$5370
$5,570
$S,570
$21,270
Discount
Factor (3.9%)
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0,000
0,000
0,000
0,000
0.000
0.000
0.000
0.000
0,000
0.000
0,000
0,000
0.000
0.000
0.000
0,000
0.000
0.000
0,000
0,000
0,000
0.000
0.000
0.000
• 0,000
Present
Worth
$1
$1
$1
$1
$i
$1
$1
$1
$0
$]
$0
$0
$0
$0
$2
$0
$0
$0
$0
$1
$0
$0
$0
$0
$0
$0
$0
so
$0
$0
$0
$0
$0
$0
$1
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
so
so
so
$0
-------
ROD for the GSACU (U)
Savannah River Site
August 2002
WSRC-RP-2002-4002
Rev. 0
PageB17ofB20
Appendix B-4. Cost Estimate for
Selected Remedy for the
ORWBG-
Summary of Present Value Analysis (Continued)
Year
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
36T
368
369
370
37 J
372
373
374
375
Annual O&M
Capital Cost Cost
$5,570
S5.570
$5,570
$5,570
$21,270
$5,570
$5,570
$5,570
55,570
$21,270
$5.570
S5.570
$5.570
$5,570
$21,270
$5.570
$5,570
$5.570
$5,570
$21,270
$5,570
$5,570
$5,570
$5370
$21,270
$5,570
$5,570
$5,570
S5.S70
$21 570
$5,570
$5,570
$5,570
$5,570
$21.270
$5,570
$5,570
$5,570
$5.570
$21,270
$5,570
$5,570
$5,570
$5,570
$21,270
$5,570
$5,570
$5,570
$5.570
$21,270
$5370
$5,570
$5,570
$5,570
$21,270
Total
Cost
$5,570
$5,570
$5,570
$5,570
$21,270
$5,570"
$5,570
$5,570
$5.570
$21.270
$5,570
$5,570
$5.570
$5.570
$21,270
$5,570
$5.570
$5.570
$5,570
$21,270
$S,570
$5,570
$5^70
$5,570
$21,270
$5,570
$5,570
$5,570
$5,570
$21,270
$5,570
$5.570
$5,570
$3,570
$21.270
$5.570
$5,570
$5,570
$5,570
S2I.270
$5,570
$5,570
$5.570
$5,570
$21,270
$5.570
$5,570
$5.570
SS.S70
$31,270
$5.570
S5.570
$5,570
S5.S70
$21,270
Discount
Factor (3.9%)
0.000
0,000
0.000
0,000
0.000
0.000
0.000
0.000
0.000
0,000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0,000
0.000
0.000
0.000
0.000
Q.OOO
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
o.ooo
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0-000
Present
Worth
$0
$0
so
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
JO
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
so
$0
$0
$0
$0
-------
MOD for the GS ACU (U)
Savannah River Site
August 2002
WSRC-RP-2002-4002
Rev. 0
Page BIS of B20
Appendix B-4. Cost Estimate for
Selected Remedy for the ORWBG -
Summary of Present Value Analysis (Continued)
Yew
316
yn
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
Annual O&M
Capital Cost Cost
$5,570
$5,510
$5.570
$5,510
$21 ,270
$5,510
$5.570
$5.570
$5,570
$21.270
$5,570
$5,570
$5,570
$5,570
$21,270
$5,570
$5,570
$5,570
$5,570
$21,270
$5,570
$5,570
$5,570
$5,570
$21,270
$5,570
$5,570
$5,570
$5,570
$21.270
$5,570
$5,570
$5,570
$5,5TO
$21.270
$5,570
$5,570
$5,570
$5,510
$21,270
$5,570
$5.570
$5,570
$5,570
$21.270
$5,370
$5,570
$5,570
$5.570
$21.270
$5,570
$5.570
S5.570
$5,570
$21.270
Total
Cost
$5,570
$5,570
$5,570
$5,570
$21.270
$5.570
$5,570
$5,570
$5,570
$21,270
$5,570
$5.570
$5,570
$5,570
$21,270
$5.570
$5,570
$5,570
$5,570
$21.270
$5,570
$5,570
$5,570
$5,570
$21.270
$5.570
$5470
$5,570
$5,570
$21.270
$5,570 "
$5.570
$5,570
$5,570
$21.270
$5,570
$5,570
$5,570
$5.570
$21,270
$5.570
$5,570
$5,570
$5.570
$21,270
$5.570
$5.570
SS.570
$5.570
$21,270
$5,570
$5.570
$5.570
$5,570
$21,270
Discount
Factor (3.9%)
0.000
0,000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0,000
0.000
0.000
0.000
0.000
0.000
0,000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0,000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0,000
0.000
0.000
0.000
0.000
0.000
Present
Worth
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
so
so
so
so
$0
so
$0
$0
so
so
$0
$0
$0
$0
$0
$0
$0
$0
$0
so
$0
$0
$0
$0
-------
ROD for the GSACU (U)
Savannah River Site
August 2002
WSRC-RP-2002-4002
Rev. 0
PageB19ofB20
Appendix B-4, Cost Estimate for Selected Remedy for the ORWBG •
Summary of Present Value Analysis (Continued)
Year
43!
432
433
434
435
436
437
43S
439
440
441
442
443
444
445
446
447
448
449
450
451
4S2
453
454
455
4S6
457
458
459
460
461
462
483
464
465
466
467
468
469
470
471
471
473
474
475
476
477
478
479
Annual O&M
Capital Cost Cost
$5,570
$S,570
$5,570
$5,570
$21.270
55,570
$5,570
$5,570
$5,570
$21.270
$5,570
$5,570
$5,570
$5,570
$21,270
$5,570
$5,570
$5,570
$5.570
$21,270
$5,570
$5,570
$5,570
$5.570
$21,270
$5,570
$5,570
$5,570
$5.570
$25.270
$5,570
$5,570
$5,570
$5,570
$21.270
$5,570
$5,570
$5,570
$5.570
$21,270
$5,570
$5,570
55,570
$5.570
$21,270
$5,570
$5,570
$5370
$5,570
Total
Cost
$5.570
$5,570
$5,570
$5,570
$21.270
$5,570
$5,570
$5,570
$5.570
$21,270
$5,570
$5,570
55,570
$5,570
121,270
$5370
$5,570
$5,570
$5.570
$21,270
$5.570
$5,570
$5,570
$5.570
$21,270
$5370
$5,570
$5.570
$5,570
$21.270
$5,570
$5,570
$5.570
$5370
$21,270
$5,570
$5,570
$5,570
$5,570
S2J.270
$5.570
$5.570
$5,570
$5.570
$21,270
$5.570
$5.570
$5,570
$5,570
Discount
Factor (3.9%)
0.000
0.000
0,000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0,000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
O.QOQ
0.000
0.000
0.000
O.OOG
0.000
0.000
0,000
0,000
Present
Worth
$0
$0
so
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
SO
$0
$0
$0
$0
$0
$0
$0
$0
$0
-------
ROD for the GSACU (U)
Savannah River Site
August 2002
WSRC-RP-2002-4002
Rev.O
PageB20ofB20
Appendix B-4. Cost Estimate for Selected Remedy for the ORWBG
Summary of Present Value Analysis (Continued)
Annual O&M Total
Year Capital Cast Cost Cost
480 $2 1 270 $21,270
481 $5.570 $5370
482 $5,570 $5,570
483 $5370 $5.570
484 $5,570 $5,570
485 $21,270 $21 ,270
486 15,570 $5,570
487 $5,570 $5370
488 $5,570 $5370
489 $5,570 $5470
490 $21270 $21,270
491 $5370 $5,570
492 $5370 $5370
493 $5370 $5370
494 $5370 $5370
495 $21,270 $21,270
496 $5370 $5,570
497 $5370 $5370
498 $5370 $5,570
499 $5,570 $5370
500 $21,270 $21,270
Totals $10,822384 $12,797,723 $23,620,107
Total Present Value of O&M Costs - ORWBG
O&M Costs:
0-100 years;
Annual inspections, general repairs & site maintenance ($5370/yr).
Biannual mowing, minor soil additions/repairs ($12,000/yr).
Replace 10% of veg cover every 1 0 years ($42,463 each).
Replace 10% of cap every 25 yews <$ 1,083,864 each).
ROD Reviews every 5 years ($1 0,000 each).
101-300 years:
Annual inspections, genera) repairs & site maintenance ($5,570/yr).
Biannual mowing, minor soil additions/repairs ($I2,000/yr).
Replace 10% of veg rover every 20 years ($42,463 each).
ROD Reviews every 5 years ($1 0,000 eadi).
301-500 years:
Annual inspections, general repairs &, site maintenance (55.57Wyr).
Brush removal every 5 years <$5,700).
ROD Reviews every 5 yean ($10.000 each).
Discount
factor (3.9%)
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
Q.00Q
0.000
0.000
0.000
0,000
0.000
0,000
0.000
0.000
0.000
0.000
0.000
Present
Worth
$0
$0
$0
so
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
$0
so
$0
$0
$0
$0
$12,071*6*
$1,249,482
Intruder Barrier Over 500-Year Radioactive Hot Spots:
Heavy rip-tap burier: $325.0Q0/«erc (SIA million for HS-500-1 through HS-500-8).
Present value > $3 1 .000, based on 3.9% discount rate and implementation in
100 years.
This cost is the capital con to furnish and install the rip-rap only. The O&M cost of cap reconstruction after
placement of the barrier is included in the long-term O&M costs for the ORWBG cap, which also
periodic refurtnsttneru of (he cap.
includes
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