EPA/ROD/R04-96/267
1996
EPA Superfund
Record of Decision:
SAVANNAH RIVER SITE (USDOE)
EPA ID: SC1890008989
OU32
AIKEN, SC
06/18/1996
-------
United States Department of Energy
Savannah River Site
Interim Record of Decision
Remedial Alternative Selection
for the Old Radioactive Waste
Burial Ground (643-E) (U)
WSRC-RP-96-102
Revision 0
March 1996
*v *''f
/^--^^X
Westinghouse Savannah River Company * =s. H^* :=. ~
Savannah River Site **^ = "= *=5r
Aiken, South Carolina 29808 s WAWN . H R ivt u 5 r tf
PREPARED FOR THE U.S. DEPARTMENT OF ENERGY UNDER CONTRACT DE-AC09-89SR18035
-------
WSRC-RP-96-102
Revision 0
March 1996
DISCLAIMER
This report was prepared by Westinghouse Savannah River Company
(WSRC) for the United States Department of Energy under Contract No.
DE-AC09-89SR18035 and is an account of work performed under that
contract. Reference herein to any specific commercial product, process, or
services by trademark, name, manufacturer or otherwise does not
necessarily constitute or imply endorsement, recommendation, or favoring
of same by WSRC or by the United States Government or any agency
thereof.
Printed in the United States of America
Prepared for
U. S. Department of Energy
and
Westinghouse Savannah River Company
Aiken, South Carolina
-------
INTERIM RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION (U)
Old Radioactive Waste Burial Ground (643-E)
WSRC-RP-96-102
Revision 0
March 1996
Savannah River Site
Aiken, South Carolina
Prepared by:
Westinghouse Savannah River Company
for the
U.S. Department of Energy Under Contract DE-AC09-89SR18035
Savannah River Operations Office
Aiken, South Carolina
-------
This page intentionally left blank.
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
DECLARATION FOR THE INTERIM RECORD OF DECISION
Unit Name and Location
Old Radioactive Waste Burial Ground (SRS Building Number 643-E)
Savannah River Site
Aiken, South Carolina
The Old Radioactive Waste Burial Ground (ORWBG) (643-E) is a part of the Burial Ground Complex
(BGC) which is listed as a Resource Conservation and Recovery Act (RCRA) 3004(u) solid waste
management unit/Comprehensive Environmental Response, Compensation and Liability Act (CERLCA)
unit in Appendix C of the Federal Facility Agreement (FFA) for the Savannah River Site.
Statement of Basis and Purpose
This decision document presents the selected remedial interim action for the ORWBG located at the SRS
in Aiken, South Carolina. The selected action was developed in accordance with CERCLA, as amended,
and to the extent practicable, the National Oil and Hazardous Substances Pollution Contingency Plan (NCP).
This decision is based on the Administrative Record File for this specific RCRA/CERCLA unit.
Assessment of the Site
Actual or threatened releases of hazardous substances from this site, if not addressed by implementing the
response action selected in this Interim Record of Decision (ROD), may present an endangerment to public
health, welfare, or the environment.
Description of the Selected Remedy
The selected interim action for the ORWBG, Placement of a Soil Cover, consists of placement of a low-
permeability soil cover (minimum thickness 2 feet) on top of the existing grade. Topsoil (vegetative soil
layer - minimum thickness of 3 inches) would be added and the area compacted and seeded to prevent
erosion. Since the ORWBG is a 76-acre area, eight soil cover sections are proposed for the ORWBG.
The proposed soil cover is consistent with the overall site strategy for the BGC because it provides for a
reduction in contaminant migration without hindering ongoing characterization efforts conducted as part
of the BGC Field Investigation Plan and without precluding any final remedial action developed during the
FFA process for the BGC.
This is an interim RCRA/CERCLA action and in no way constitutes a final action for the ORWBG. A final
remedial action will be evaluated and conducted in the future according to the requirements of the FFA.
Declaration Statement
This interim action is protective of human health and the environment, complies with Federal and State
applicable or relevant and appropriate requirements for this limited-scope action, and is cost-effective.
Because this action does not constitute the final remedy for the ORWBG, the statutory preference for
remedies that employ treatment that reduces toxicity, mobility, or volume
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
as a principal element will be addressed by the final response action. Subsequent actions are planned to
address fully the threats posed by conditions at this ORWBG. Because this remedy will result in hazardous
substances remaining on site above health-based levels, a review will be conducted to ensure that the
remedy continues to provide adequate protection of human health and the environment within five years
after commencement of the remedial action. Because this is an interim action ROD, review of this site and
of this remedy will be ongoing as development of final remedial alternatives for the ORWBG continues.
Date T F. Heeoan
Assistant Manager for Environmental Restoration and Solid Waste
U.S, Pcpt, of Energy, Savannah River Operations Office
Date 4ohn H H^nldnson1; Jr.
Regional Administrator
U.S. Envircmmsntal Protection Agency
Bate IL
Deputy Commissioner
Environmental Quality Control
South Carolina Department of HcaJth and Environmental Control
-------
DECISION SUMMARY
REMEDIAL ALTERNATIVE SELECTION (U)
OLD RADIOACTIVE WASTE BURIAL GROUND (643-E)
WSRC-RP-96-102
Revision 0
March 1996
Savannah River Site
Aiken, South Carolina
Prepared by:
Westinghouse Savannah River Company
for the
U.S. Department of Energy Under Contract DE-AC09-89SR18035
Savannah River Operations Office
Aiken, South Carolina
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
DECISION SUMMARY
TABLE OF CONTENTS
Section Page
I. Site and Operable Unit Name, Location, and Description 1
II. Operable Unit History and Compliance History 1
III. Highlights of Community Participation 5
IV. Scope and Role of Operable Unit Within the Site Strategy 5
V. Summary of Operable Unit Characteristics 8
VI. Summary of Operable Unit Risks 9
VII. Description of the Considered Alternatives 10
VIII. Summary of Comparative Analysis of the Alternatives 14
IX. The Selected Remedy 17
X. Explanation of Significant Changes 20
XL References 21
List of Figures
Figure 1: Location of the Burial Ground Complex at the Savannah River Site 2
Figure 2: Location of the Old Radioactive Waste Burial Ground 3
Figure 3: General Locations of Disposal Sections in the Old Radioactive Waste
Burial Ground 4
Figure 4: Burial Ground Complex Project Schedule 6
Figure 5: Old Radioactive Waste Burial Ground Soil Cover Configuration 19
List of Tables
Table 1: Applicable or Relevant and Appropriate Requirements (ARARs) and
To-Be-Considered (TBC) Guidance 12
Table 2: Evaluation of Alternative Actions Considered for Remediation of the
ORWBG Contamination 15
Appendix
A. Responsiveness Summary 22
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
I. Site and Operable Unit Name, Location,
and Description
The Savannah River Site (SRS) occupies
approximately 310 square miles of land adjacent to
the Savannah River, principally in Aiken and
Barnwell counties of South Carolina (Figure 1). SRS
is a secured U.S. Government facility with no
permanent residents. SRS is located approximately
25 miles southeast of Augusta, Georgia and 20 miles
south of Aiken, South Carolina.
SRS is owned by the U.S. Department of Energy
(DOE). Management and operating services are
provided by Westinghouse Savannah River
Company (WSRC). SRS has historically produced
tritium, plutonium, and other special nuclear
materials for national defense. SRS has also
provided nuclear materials for the space program
and for medical, industrial, and research efforts.
Chemical and radioactive wastes are by-products of
nuclear material production processes.
The Federal Facility Agreement (FFA) lists the
Burial Ground Complex (BGC) as a Resource
Conservation and Recovery Act
(RCRA)/Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) unit
that requires further evaluation. The BGC is an area
which occupies approximately 195 acres in the
central part of SRS between F- and H-Separation
Areas, on a nearly flat divide between Upper Three
Runs Creek to the north and Four Mile Creek to the
south.
The BGC includes the Old Radioactive Waste
Burial Ground (ORWBG) (Figure 2) and other
operable units such as the Mixed Waste
Management Facility (MWMF) (closed under
RCRA), the Low Level Radioactive Waste Disposal
Facility (LLRWDF), Solvent Tanks SI - S22
(located in the ORWBG and currently being
characterized), Solvent Tanks S23 - S30 (located
near LLRWDF, covered under a separate RCRA
closure), and Solvent Tank S3 2 (closed under
RCRA).
The ORWBG comprises a disposal area for solid
radioactive waste produced at the SRS, as well as
shipments from other U.S. Department of Energy
and Department of Defense facilities. The ORWBG,
designated Building Number 643-E, has a
quadrilateral shape and occupies approximately 76
acres. The ORWBG has contributed to localized
shallow aquifer groundwater contamination. The
plume of groundwater contamination from the
ORWBG seeps into the old F-Area effluent stream
which flows into Four Mile Creek which in turn
flows into the Savannah River. Other
RCRA/CERCLA units within the BGC are
undergoing characterization and investigation to
determine impacts to the environment.
II. Operable Unit History and Compliance
History
Operable Unit History
The ORWBG began receiving waste in 1952 and
was filled in 1972. The ORWBG was divided into
sections to accommodate disposal of various
levels/types of radioactive waste materials (Figure
3). These materials include transuranic (TRU)
waste, low-level waste, and intermediate-level waste
generated at SRS; and waste generated elsewhere.
Compliance History
At SRS, waste materials are managed which are
regulated under the RCRA. Certain SRS activities
have required Federal operating or post-closure
permits under RCRA. SRS received a RCRA
hazardous waste permit from the South Carolina
Department of Health and Environmental Control
(SCDHEC) on September 5, 1995. Part V of the
permit mandates that SRS establish and implement
an RFI Program to fulfill the requirements specified
in Section 3004(u) of the Federal permit.
Hazardous substances, as defined by CERCLA, are
also present in the environment at SRS. On
December 21, 1989, the SRS was placed on the
National Priorities List (NPL).
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
Figure 1. Location of the Burial Ground Complex at the Savannah River Site.
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
Figure 2. Location of the Old Radioactive Waste Burial Ground.
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
FJ OQQ
TtOOO
TiOOO
ns
Figure 3. General Locations of Disposal Sections in the Old Radioactive Waste Burial Ground
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
A site placed on the NPL comes under the jurisdiction
of CERCLA. In accordance with Section 120 of
CERCLA, DOE has negotiated an FFA (FFA, 1993)
with the U.S. Environmental Protection Agency (EPA)
and SCDHEC to coordinate remedial activities at SRS
into one comprehensive strategy which fulfills these
dual regulatory requirements.
III. Highlights of Community
Participation
Public participation requirements are listed in
Sections 113 and 117 of CERCLA. These
requirements include the establishment of an
Administrative Record File that documents the
investigation and selection of the remedy for
addressing the ORWBG. The SRS Public
Involvement Plan (DOE, 1994) is designed to
facilitate public involvement in the decision-making
processes for permitting, closure, and the selection
of remedial alternatives. The SRS PIP addresses the
requirements of RCRA, CERCLA, and the National
Environmental Policy Act (NEPA). Section 117(a)
of CERCLA, as amended, requires the preparation
of a proposed plan as part of the site remedial
process. The Interim Action Proposed Plan for the
Old Radioactive Waste Burial Ground (643-E)
(WSRC, 1995), which is part of the Administrative
Record File, highlights key aspects of the
investigation and identifies the preferred action for
addressing the ORWBG.
The Administrative Record File, which contains the
information pertaining to the selection of the
response action, was made available at the EPA
office and at the following locations:
U.S. Department of Energy
Public Reading Room
Gregg-Graniteville Library
University of South Carolina-Aiken
171 University Parkway
Aiken, South Carolina 29801
(803) 641-3465
Thomas Cooper Library
Government Documents Library
University of South Carolina
Columbia, South Carolina 29208
(803) 777-4866
Similar information is available through the
repositories listed below:
Reese Library
Augusta College
25 00 Walton Way
Augusta, Georgia 30910
(706) 737-1744
Asa H. Gordon Library
Savannah State College
Tompkins Road
Savannah, Georgia 31404
(912)356-2183
The public was notified of the comment period for the
proposed plan through mailings of the SRS
Environmental Bulletin, a newsletter sent to
approximately 3500 citizens in South Carolina and
Georgia, and through notices in local newspapers
including the Aiken Standard, The State, Augusta
Chronicle, North Augusta Star, Barnwell
People-Sentinel, Allendale Citizen Leader, and the
Augusta Focus.
The public comment period began on February 2,1996
and ended on March 2, 1996. A public meeting was
held on February 27, 1996 at the North Augusta
Community Center. Comments received on the Interim
Action Proposed Plan for the Old Radioactive Waste
Burial Ground (643-E) are addressed in the
Responsiveness Summary (Appendix A).
IV. Scope and Role of Operable Unit Within
the Site Strategy
The BGC includes the ORWBG and other operable
units (OUs) such as the MWMF (closed under RCRA),
Solvent Tanks SI - S22, Solvent Tanks S23 - S30,
Solvent Tank S32 (closed under RCRA), and the
LLRWDF. The overall plan for characterization and
remediation at the BGC is presented in Figure 4. This
figure shows both RCRA and
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
FY 1993
FY 1994
FY 1995
FY 1996
FV 1997
FY 1998
FY 1999
FY 2000
FY 2001
FY2QQ2
RCRA Activities
RCRA PcnRllPmi-Ctauzc AetMtlti (Jjidu*I« MWMFmnd LLRWDFJ
MTWMF
Omar* Pkh
r~i --- .-T
0! Rtv I [f
LLRWDF
Our*ctj!rli*tion - BGCFkld [n^wtijulcKi Pltrr
RFI/R1/1RA
CMS/FS
PP
R
D
Ren*il*J Artlcn
Burtftl Greun4 Compki (Includes 0RWBG, MWMF, LLRWDF, jolvenl tftnki, ete.)
CERCL.4 (FFA)
interim Action )
t
ORWBG Interim Action
Note: The dotted lines represent approximate activity duration.
Figure 4. Burial Ground Complex Project Schedule.
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
CERCLA estimated project schedules for the major
activities at the BGC.
The entire BGC is listed as one OU under CERCLA.
The investigation/assessment process will address
all of the facilities, including those which have been
closed under RCRA. Once appropriate
characterization data is available and a risk analysis
has been performed, a final remedial action for the
BGC will be implemented. The MWMF was closed
(via capping) under RCRA and had a ROD issued in
fiscal year (FY) 1993. The LLRWDF is currently
undergoing closure (via capping) under RCRA.
Groundwater associated with the entire BGC is
being addressed under the RCRA permit for the
MWMF in accordance with the second amendment
to Settlement Agreement 87-52-SW. Revision 3 to
the RCRA Part B permit application of the MWMF
was submitted to SCDHEC on November 15, 1995.
This revision to the RCRA application includes a
characterization of the plume which originates from
the ORWBG. It also prepares a strategy and
schedule for characterization, development of clean
up levels, and preparation of remediation plans for
each of the separate plumes of contamination
associated with the BGC.
Characterization for the BGC is currently ongoing
through the BGC Field Investigation Plan (FIP) and
will encompass environmental releases from all
facilities within the BGC (MWMF, LLRWDF,
ORWBG, etc.). Characterization data currently
available for the BGC indicates that the ORWBG
has contributed to localized shallow aquifer
contamination. Given this information and the
current FFA process schedule for the BGC
(remedial action currently planned to begin in FY
2001), an interim action is necessary for the
ORWBG.
The role of the interim action at the ORWBG
unit is a reduction in stormwater infiltration
through the waste layer which will minimize
contaminant migration to the water table. The
interim action proposes to place a low-
permeability soil cover over the ORWBG unit.
Topsoil with a vegetative cover will also be a part of
the interim action. The soil cover will be sloped to
promote surface runoff, minimize surface erosion,
and control the leaching of hazardous substances
from the source material.
Existing institutional controls, environmental
monitoring, and site maintenance would also be
components of this alternative. Visual inspection of
the soil cover will be performed by trained
individuals at regular intervals and after significant
rainstorms. Any observed damage, erosion, or
subsidence will be repaired to conform with the
original soil cover contours.
This interim action addresses source control at the
ORWBG in advance of the final remedial action for
the BGC. The proposed soil cover is consistent with
the overall site strategy because it provides for a
reduction in contaminant migration without
hindering ongoing characterization efforts
conducted as part of the BGC FIP and without
precluding any final remedial action developed
during the FFA process for the BGC.
The BGC FIP is a comprehensive environmental
characterization plan which was submitted to
SCDHEC in January 1995. The plan describes an
aggressive program to collect hydrogeologic,
groundwater, soil, and surface water data to support
all RCRA and CERCLA activities for the burial
ground complex. The FIP calls for a variety of
technologies to be used in characterization. These
include water sampling and geologic data collection
using innovative direct push technologies,
installation of new monitoring wells, coring,
geophysical logging, wetlands sampling, and
pumping tests to determine aquifer properties.
Implementation of the FIP is well underway.
Characterization of the plume at the
ORWBG has been completed in accordance
with the FIP and submitted to SCDHEC in
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
revision 3 to the RCRA Part B permit application
for the MWMF.
Groundwater sampling via Cone Penetrometer
hydrocone and Hydropunch to delineate the vertical
and lateral extent of the three burial ground plumes
has been completed. Twenty three (23) new wells
have been installed to monitor groundwater flow
and contamination in the vicinity of the groundwater
divide. Soil, wetlands, and stream sampling are in
progress. Data evaluation is ongoing.
Additional coring and water sampling to gather
information in data sparse areas around the burial
ground are planned for later this year. This data will
be used to improve the ability of groundwater
models to predict future contaminant migration. This
data will also improve our ability to model the
interaction effects of multiple caps and groundwater
remediation projects in the vicinity of the burial
ground. Pumping tests to gain information which
will support corrective action design are being
planned and are scheduled for execution in FY
1997.
The results of the BGC FIP will be used to develop
the BGC RFI/RI/BRA. The results of the
RFI/RI/BRA will be used to develop the final
remedial alternatives for the BGC including the
ORWBG.
V. Summary of Operable Unit
Characteristics
The history of the ORWBG is summarized from the
Phase IIRFI/RI Work Plan for the Burial Ground
Complex (WSRC, 1994). The ORWBG began
receiving waste in 1952 and was filled in 1972.
Examples of materials disposed of at the ORWBG
include the following:
Incidental waste from laboratory and
production operations,
Contaminated equipment,
Lead,
Reactor hardware,
Spent deionizer resins,
Spent lithium-aluminum targets,
Irradiated process oil from pumps in the
tritium facilities and reactor areas,
Mercury from gas pumps in tritium
facilities,
Cadmium,
Scintillation fluid, and
Shipments from off-site (e.g., radioactive
waste from military hardware).
Earthen trenches within the ORWBG were
excavated 20 feet wide, 20 feet deep, and up to 700
feet long. The trenches were filled with the materials
listed above. Trenches were covered with 4 feet or
more of soil to reduce surface radiation to less than
6mR/hr.
Beginning in 1962, records were kept of the
contents, radiation level, and approximate storage
location of each shipment of waste. Many of the
waste volumes and radionuclide quantities were
estimated, including information on waste disposed
of before 1962. The location of the burial/storage
area for each shipment of waste was defined by a
100 foot grid system laid out in 1962. These grids
were further divided into 20 foot squares.
Until 1965, TRU waste contained within plastic
bags and cardboard was buried in unlined trenches
designated specifically for this waste. Between 1965
and 1972, TRU waste was segregated according to
TRU content. Waste that did not fit into the
prefabricated concrete containers was encapsulated
in-place in concrete.
Inorganic constituents, such as lead (used to shield
a variety of waste forms or discarded due to high
contamination levels) and cadmium (from control
rods, safety rods, and shielding), were placed in the
ORWBG.
One trench in the east-central part of the ORWBG
approximately 100 feet long was
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
used for disposal of an unknown quantity of empty
oil drums.
From 1953 through 1968, organic solvents were
incinerated in open shallow unlined trenches located
in the north-central part of the ORWBG.
Various solvents including napthalene, n-paraffin,
toluene, tributylphosphate (TBP), TBP-kerosene,
trimethylbenzene, ultrasene, andxylene were stored
in 22 underground storage tanks at the ORWBG.
However, the cleanup of these tanks are not being
addressed as part of this proposed interim action.
The action for closure of the solvent tanks will be
addressed in a separate proposed plan and will
therefore be without a cover until the final remedial
action is initiated.
VI. Summary of Operable Unit Risks
General Risk Information
At the present time, a risk assessment for the BGC
(including the ORWBG) has not been conducted,
but is scheduled to be completed by November
1997. The risks, in general, are the contaminants in
the buried waste. These contaminants have been
released to the soil and groundwater due to
infiltration and percolation. Future releases of
contaminants to the soil and groundwater can be
reduced by reducing infiltration and percolation
from stormwater/rain events, thereby minimizing
future risks.
The estimated stormwater infiltration for the
ORWBG existing conditions is 45% for a given
rainfall event over a twenty year period. After
installation of the soil cover, it is estimated that the
stormwater infiltration will decrease to 13% for a
given rainfall event over a twenty year period.
Therefore, this soil cover yields a 70% reduction in
the amount of water infiltration through the waste
layer and reduces the potential for introducing
contaminants into the groundwater (Serrato, 1994).
The reduction in stormwater infiltration is consistent
with the goals of the National Oil and Substances
Pollution Contingency Plan (NCP) because it
provides risk reduction early in the
investigation/assessment process without precluding
any final action. The soil cover will control the
source hazards by reducing contaminant migration
and, minimizing future groundwater remediation
efforts. Additionally, the soil cover will not prevent
initiation of any final action developed after full
characterization and risk analysis have been
completed for the BGC.
Constituents of Concern (COCs)
The focus of this interim action is to control the
leaching of hazardous substances from the source
material into the groundwater.
The information listed below was summarized from
the RFI/RI Work Plan for the Burial Ground
Complex (U) (WSRC, 1994).
Soil gas surveys conducted at the ORWBG indicate
that the chlorinated solvents tetrachloroethylene
(PCE) and trichloroethylene (TCE) were observed
to be widely distributed in the ORWBG.
Observations of 1,1,1-trichloroethane were also
observed, but were not as widely distributed as the
PCE and TCE.
Scattered, low levels of carbon tetrachloride,
chloroform, and trans-1,2-dichloroethylene were
also observed. The most significant observations of
trans-1,2-dichloroethylene were found in the central
part of the ORWBG. Concentrations range from 201
to 1000 ppbv and appear to correlate with low
concentrations of PCE in this area. It is suggested
that the trans- 1,2-dichloroethylene may be present
as the result of biological degradation of PCE.
Only a few, widely spaced observations of the
aromatic hydrocarbons benzene, toluene,
ethylbenzene, and xylenes were made in the
ORWBG. The saturated hydrocarbons, C6-C9, were
observed with a slightly greater frequency than the
aromatics. In particular,
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
hexane, heptane, and octane are well correlated with
the observations of trans-1,2-dichloroethylene. No
observations of decane were made. Pentane is
widely distributed in low concentrations.
The levels of methane observed at the ORWBG
vary. The higher levels of methane result from the
anaerobic biological degradation of buried waste.
Lower levels of methane and the other light
hydrocarbons may be due to the natural background
in this area.
Historically, groundwater data indicate that the
tritium concentrations in wells monitoring the
ORWBG average 140,745 pCi/mL and range from
15 pCi/mL to nearly 30 million pCi/mL. The
nonvolatile beta concentrations average 107 pCi/L
and range from 0.15 pCi/L to greater than 9000
pCi/L. The gross alpha concentrations average 4
pCi/L and are generally less than 35 pCi/L. As
discussed earlier, radioactive materials were
disposed of in sections of the ORWBG according to
the type and level of radioactivity of the waste.
Water samples containing high levels of tritium,
nonvolatile beta emitters, or gross alpha emitters
were obtained from wells monitoring sections of the
ORWBG in which waste containing high
concentrations of these constituents was buried.
Concentrations of these constituents throughout the
ORWBG thus vary considerably, and are generally
much lower than the upper ranges noted above.
Metallic constituents have also been found in the
ORWBG groundwater samples. These metals
include cadmium, mercury, and lead. Mercury and
lead concentrations have been shown to be highest
in the northeast section of the ORWBG. Cadmium
concentrations appear to be highest in the
southwestern portion of the ORWBG.
Gas chromatography/mass spectrometry analysis of
groundwater below the ORWBG indicated the
presence of 63 organic compounds. Many of these
compounds were indicative of spent solvent, oil and
liquid scintillation wastes, and degradation products
of humic substances. Four priority pollutants
(benzene, toluene, phenol, and napthalene) were
present in low concentrations. Acetophenone, a
RCRA Appendix IX constituent, was tentatively
identified in the groundwater.
The concentrations often priority pollutant volatile
organic compounds detected in groundwater
samples near the ORWBG include carbon
tetrachloride, chloroform, 1,1-dichloroethane,
1,2-dichloroethane, 1,1-dichloroethylene,
trans-1,2-dichloroethane, toluene, PCE, TCE, and
1,1,1-trichloroethane. Five of these volatile organic
compounds (carbon tetrachloride,
1,2-dichloroethane, PCE, 1,1,1 -trichloroethane, and
trans-1,2-dichloroethane) occurred in concentrations
above their respective maximum concentration
limits. The highest number and concentrations of
volatile organic compounds occurred along the
southern boundary of the ORWBG.
VII. Description of the Considered
Alternatives
Three alternatives were evaluated for interim action
remediation of the contamination at the ORWBG.
Each alternative is described below:
Alternative 1
No Action.
Alternative 2
Placement of a Soil Cover
Alternative 3
Placement of a RCRA-Like Cap
All three alternatives include engineering and
administrative controls to guard against inadvertent
human and ecological exposure to contamination.
Also, ongoing monitoring and approved
characterization plans will continue during
remediation.
The alternatives must meet or attain applicable or
relevant and appropriate requirements (ARARs).
The following statutes and
10
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
regulations were reviewed as potential ARARs and
To-Be-Considered (TBC) guidance:
Atomic Energy Act
RCRA
Clean Air Act
Safe Drinking Water Act
Clean Water Act
Toxic Substances Control Act
South Carolina Pollution Control Act
South Carolina Wastewater Regulations
South Carolina Drinking Water
Regulations
South Carolina Air Pollution Control
Regulations
South Carolina Water Classification
Standards
South Carolina Well Standards and
Regulations
South Carolina Hazardous Waste
Management Regulations
Stormwater Management and Sediment
Reduction
DOE Orders
After reviewing the above mentioned statues and
regulations, there were no location-specific ARARs
and TBC guidance identified. Chemical-specific and
action-specific ARARs and TBC guidance are listed
in Table 1.
Alternative 1 - No Action.
Under Alternative 1, the ORWBG would remain in
its current condition. Concentrations and activity
levels of the COCs would gradually be reduced with
time through natural attenuation processes such as
dispersion and radioactive decay. Contaminated
groundwater would continue to discharge into
surface waters. Stormwater would continue to
infiltrate into the trenches and leach contaminants
into the groundwater. The no action alternative
limits future characterization due to "As Low As
Reasonably Achievable (ALARA)" issues.
Existing institutional controls, environmental
monitoring, and site maintenance would continue
and would be components of the no action
alternative. This alternative is currently being
implemented. There are no capital costs associated
with this alternative. Maintenance and operation
costs will be fairly similar from alternative to
alternative; and is therefore not discussed separately.
Alternative 2 - Placement of a Soil Cover
Under Alternative 2, no buried waste material would
be removed. A series of low-permeability soil
covers would be installed on top of the existing
grade. A vegetative layer of 50% topsoil, 50%
common soil would be added and the area
compacted and seeded to prevent erosion.
Each low-permeability soil cover section will have
a minimum thickness of 2 feet of compacted,
low-hydraulic conductivity soil (nominal in-place
saturated hydraulic conductivity of 1 x 10"5 cm/sec
or less) (Bennett, 1996). The soil covers will also
have an upper surface with a slope to promote
surface runoff and minimize surface erosion.
The vegetative layer will be placed at a minimum
thickness of 6 inches and will have the ability to
survive and function with little or no maintenance
(Bennett, 1996). The surface slope will also promote
runoff and minimize surface erosion.
The soil cover sections could be easily repaired
should destruction of portions of the covers occur
through subsidence or cover intrusion be required
for future assessments or remedial actions. The soil
covers provide shielding for future waste/"hot spot"
removal, if required (Frye-O'Bryant et al., 1993).
"Hot spot" removal, in conjunction with placement
of the soil cover, is not being proposed at this time,
based on the following:
the nonhomogeneous nature and
disposition of the wastes in the ORWBG
(landfill-like)
"hot spot" source exact location is
unknown (within the waste unit)
11
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
Table 1. Applicable or Relevant and Appropriate Requirements and To-Be-Considered Guidance.
Actions
Requirements
Prerequisites
Federal Citation
South Carolina
Code of Laws
CHEMICAL-SPECIFIC
Protection of the
general public
from all sources
of radiation
Worker
Protection
The general public
must not receive an
effective dose
equivalent greater
than 100 mrem/year.
All releases of
radioactive material
must be ALARA
Maintains worker
exposures to ALARA
Radiation Protection
for Occupational
Workers
Dose received by the
general public from all
sources of radiation
exposure at a DOE
facility - TBC
guidance
Releases of radioactive
material from DOE
activities - TBC
guidance
Internal and external
sources of continuous
exposure to
occupational workers
at a DOE facility -
TBC guidance
Control of radiation
exposures to
occupational workers
at a DOE facility -
ARAR
DOE Order 5400.5;
DOE Order 5 820. 2A
DOE Order 5400.5
DOE Order 5480. 11;
DOE Order 5 820. 2A
10CFR835
ACTION-SPECIFIC
Erosion Control
Closure
Activities
Develop a plan for
erosion sediment
control
During closure,
residual radioactivity
levels for surface
soils shall comply
with existing DOE
decommissioning
guidelines.
Land disturbing
activities - Applicable
Disposal site closure
activities - TBC
guidance
DOE Order 5 820. 2A
SC 72-300
Acronyms Used in Table 1
ALARA As Low As Reasonably Achievable
CFR Code of Federal Regulations
DOE Department of Energy
SC South Carolina
TBC To-Be-Considered
12
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
current characterization technologies would
not provide location of "hot spot" sources,
and
if the BGC RFI/RI/FS process concludes
"hot spot" source and/or "waste retrievals"
are to be done, this interim action soil cover
will not preclude that action and will
provide additional shielding for the final
action remediation workers.
The existing groundwater monitoring wells within the
covered area will need to be extended to meet the
increased elevation or abandoned (Frye-O'Bryant et
at, 1993).
Existing institutional controls, environmental
monitoring, and site maintenance would also be
components of this alternative. Visual inspection of
the soil cover will be performed by trained individuals
at regular intervals and after significant rainstorms.
Any observed damage, erosion, or subsidence will be
repaired to conform with the original soil cover
contours.
This alternative could be implemented in
approximately 18 months. This timeframe is required
for the construction activities related to erosion
control, the sedimentation basin, and the soil and
vegetative covers. The time required for preparation
and regulatory approval of the IAPP, Interim Action
Record of Decision (IROD), and the combined
Remedial Design/Remedial Action Work
Plan/Remedial Design Report is independent of the 18
months required for construction.
The estimated capital cost for this alternative is $10
million for 76 acres. The cost estimate is based on
previous closure cover systems constructed at the SRS
and economic evaluation studies for closure cover
systems at hazardous waste units. The estimated unit
cost for this alternative is $3 per square foot. The
major subtasks associated with this alternative are:
design and construction of the soil layer,
stormwater management system design,
construction, and permitting,
health and safety documentation
development, and
support and indirect tasks.
Alternative 3 - Placement of a RCRA-Like Cap
Under Alternative 3, no buried waste would be
removed. The existing cover soil will be prepared
for the placement of the foundation layer. Once
the foundation layer is placed, placement of the
final low-permeability cover system (cap) will be
completed. The cap could possibly consist of the
following materials: geogrid, geosynthetic clay
liner, flexible membrane liner, and ageocomposite
drainage layer. Topsoil (vegetative cover) would
be added and the area compacted and seeded to
prevent erosion.
The cap would meet more stringent criteria (e.g.,
1 x 10~7 cm/s permeability or less) and the topsoil
(vegetative cover) would meet the same
requirements as described in Alternative 2. The
cap complicates implementation of future
characterization, if required, without loss of
containment integrity. The groundwater
monitoring wells will also need to meet the same
requirements as listed in Alternative 2.
Existing institutional controls, environmental
monitoring, and site maintenance would also be
components of this alternative.
This alternative could be implemented in
approximately 24 months. This timeframe is
required for the construction activities related to
the RCRA-like cap. The time required for
preparation and regulatory approval of the IAPP,
IROD, and the combined Remedial
Design/Remedial Action Work Plan/Remedial
Design Report is independent of the 24 months
required for construction.
The estimated capital cost for this alternative is
$25 million for 76 acres. The cost estimate is
based on previous closure cover systems
constructed at the SRS and economic
13
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
evaluation studies for closure cover systems at
hazardous waste units. The estimated unit cost for this
alternative is $7.5 per square foot. The major subtasks
associated with this alternative are:
design and construction of the RCRA-like cap,
stormwater management system design,
construction, and permitting
health and safety documentation development,
and
support and indirect tasks.
VIII. Summary of Comparative Analysis of the
Alternatives
Description of Nine Evaluation Criteria
Each of the interim remedial alternatives was
evaluated using the nine criteria established by the
NCP. The criteria were derived from the statutory
requirements of CERCLA Section 121. The NCP [40
CFR § 300.430 (e) (9)] sets forth nine evaluation
criteria that provide the basis for evaluating
alternatives and selecting a remedy. The criteria are:
overall protection of human health and the
environment,
compliance with ARARs,
long-term effectiveness and permanence,
reduction of toxicity, mobility, or
volume through treatment,
short-term effectiveness,
implementability,
cost,
state acceptance, and
community acceptance.
The interim remedial action alternatives discussed in
the Section VII have been evaluated using the nine
criteria listed above. Table 2 presents the evaluation of
the alternatives.
Brief descriptions of these criteria are given below.
Overall Protection of Human Health and the
Environment - The interim action remedial
alternatives are assessed to determine whether they
adequately protect human health and the environment
from unacceptable risks posed by hazardous
substances at the unit. The alternatives must
eliminate, reduce, or control exposure levels
established during development of remediation
goals.
Compliance with Applicable or Relevant and
Appropriate Requirements (ARARs) - ARARs are
Federal and state environmental regulations that
establish standards which remedial actions must
meet. There are three types of ARARs: (1)
chemical-specific, (2) location-specific, and (3)
action-specific.
Chemical-specific ARARs are usually health-or
risk-based, levels or methodologies which, when
applied to unit-specific conditions, result in the
establishment of numerical values. These values
establish the acceptable amount or concentration
of a chemical that may be found in, or discharged
to, the surrounding environment. Often these
numerical values are promulgated in Federal or
state regulations.
Location-specific ARARs are restrictions placed
on the concentration of hazardous substances or
the conduct of activities solely because they are in
specific locations. A unit's location is a
fundamental determinant of its impact on human
health and the environment. Some examples of
specific locations include floodplains, wetlands,
historic places, and sensitive ecosystems or
habitats.
Action-specific ARARs are usually technology- or
remedial activity-based requirements or
limitations on actions taken with respect to
hazardous substances or unit-specific conditions.
These requirements are triggered by the particular
remedial activities that are selected to accomplish
a remedy.
The remedial activities are assessed to determine
whether they attain ARARs or provide grounds
for invoking one of the five waivers for ARARs.
These waivers are:
14
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
Table 2.
Evaluation of Alternative Actions Considered for Remediation of ORWBG Contamination.
Evaluation Criteria
Overall Protection of Human
Health and the Environment
Compliance with ARARs
Long-term effectiveness and
permanence
Reduction of toxicity, mobility, or
volume through treatment
Short-term effectiveness
Alternative 1
No Action
Minimal
There are no ARARs associated
with this alternative.
This evaluation criteria does not
apply to Interim Actions.
This alternative does not reduce
toxicity, mobility, or volume
through treatment since there is no
treatment process.
This alternative does not provide a
short-term remedy for preventing
discharges of contaminated
aroundwater to surface streams.
Alternative 2
Placement of a Soil Cover,
Without Excavation and
Removal of Buried Waste
This alternative is protective of
human health and the environment.
Other than worker protection
standards, there are no ARARs
associated with this alternative.
This evaluation criteria does not
apply to Interim Actions.
This interim remedial action will
decrease leachate production and
will reduce contaminant transport
to the groundwater and as such a
reduction in mobility of
contaminants will occur.
This alternative will decrease
leachate production and will reduce
contaminant transport to the
aroundwater.
Alternative 3
Placement ofaRCRA-Like
Cap, Without Excavation
and Removal of Buried
Waste
This alternative is protective of
human health and the environment.
Other than worker protection
standards, there are no ARARs
associated with this alternative.
However, RCRA guidance on caps
are To-Be-Considered.
This evaluation criteria does not
apply to Interim Actions.
This interim remedial action will
decrease leachate production and
will reduce contaminant transport
to the groundwater and as such a
reduction in mobility of
contaminants will occur. This
alternative provides a greater
reduction in mobility of
contaminants than Alternative 2.
This alternative will decrease
leachate production and will reduce
contaminant transport to the
aroundwater.
15
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
Table 2. Evaluation of Alternative Actions Considered for Remediation of ORWBG Contamination (con't).
Evaluation Criteria
Short-term effectiveness (con't)
Implementability
Cost
State Acceptance
Community Acceptance
Alternative 1
No Action
This alternative is already in place.
Capital Cost = None
This criterion will be completed
following review by the appropriate
regulatory agencies.
This criterion will be completed
following public review.
Alternative 2
Placement of a Soil Cover,
Without Excavation and
Removal of Buried Waste
Since risks to the offsite population
are minimal, no measures to protect
the community will be required
during remediation and during the
time period before remedial goals
are met. Protection of workers will
be required during cover
installation. Monitoring of this area
will continue and therefore,
exposure to the current (non-
remediation) workers will be
reduced.
The cover material is readily
available from onsite sources. This
alternative could be implemented in
about 18 months. This timeframe
does not include the time necessary
for document preparations,
regulatory review, etc.
Capital Cost = app. $10 million
This criterion will be completed
following the review by the
appropriate regulatory agencies.
This criterion will be completed
following public review.
Alternative 3
Placement ofaRCRA-Like
Cap, Without Excavation
and Removal of Buried
Waste
Since risks to the offsite population
are minimal, no measures to protect
the community will be required
during remediation and during the
time period before remedial goals
are met. Protection of workers will
be required during cover
installation. Monitoring of this area
will continue and therefore,
exposure to the current (non-
remediation) workers will be
reduced.
The cap materials are available
from off-site vendors. This
alternative could be implemented in
about 24 months. This timeframe
does not include the time necessary
for document preparations,
regulatory review, etc.
Capital Cost = app. $25 million
This criterion will be completed
following the review by the
appropriate regulatory agencies.
This criterion will be completed
following public review.
16
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
the remedial action is an interim measure
and will become a part of a total remedial
action that will attain the ARAR,
compliance will result in greater risk to
human health and the environment than
other alternatives,
compliance is technically impracticable
from an engineering perspective,
the alternative remedial action will attain
an equivalent standard of performance
through use of another method or
approach,
the state has not consistently applied the
promulgated requirement in similar
circumstances or at other remedial action
in the state.
Long-Term Effectiveness and Permanence-
Long-term effectiveness and permanence does not
apply to an interim action.
Reduction of Toxicitv. Mobility, or Volume
Through Treatment - The interim action remedial
alternatives are assessed based on the degree to
which they employ treatment that reduces toxicity,
mobility, or volume of contaminants associated with
the unit.
Short-Term Effectiveness - The interim action
remedial alternatives are assessed considering
factors relevant to implementation of the remedial
action, including risks to the community during
implementation, impacts on workers, potential
environmental impacts (e.g., air emissions), and the
time until protection is achieved.
Implementabilitv - The interim action remedial
alternatives are assessed by considering the
difficulty of implementing the alternative including
technical feasibility, constructability, reliability of
technology, ease of undertaking additional remedial
actions (if required), monitoring considerations,
administrative feasibility (regulatory requirements),
and availability of services and materials.
Cost - The evaluation of remedial alternatives must
include capital and operational and maintenance
costs. Present worth costs are estimated within
+50/-30 percent, per EPA guidance. In estimating
the present worth cost, a discount rate of five
percent is used and inflation is considered to be zero
percent. This discount represents the estimate of
dollar value in future years. A sensitivity analysis
will be used when sufficient uncertainty exists
regarding the design, implementation, operation, or
effective life of an alternative. The cost estimates
given with each alternative are prepared from
information available at the time of the estimate.
The final costs of the project will depend on actual
labor and material costs, actual site conditions,
productivity, competitive market conditions, final
project scope, final project schedule, and other
variable factors. As a result, the final project costs
may vary from the estimates presented herein.
State Acceptance - The alternatives assessment must
evaluate state concerns. State acceptance will be
addressed through the state's participation in the
FFA process.
Community Acceptance - Community comments
regarding the various components of alternatives
will be assessed. Public comments concerning the
proposed remedy will be incorporated into the
Responsiveness Summary of the IROD.
IX. The Selected Remedy
Alternative 2, Placement of a Soil Cover, has been
selected as the preferred interim action. This
alternative consists of placement of a
low-permeability soil cover (minimum thickness 2
feet) on top of the existing grade. A vegetative layer
- minimum thickness of 6 inches would be added
and the area compacted and seeded to prevent
erosion.
Each low-permeability soil cover section will have
a minimum thickness of 2 feet of compacted,
low-hydraulic conductivity soil (nominal in-place
saturated hydraulic conductivity of 1 x 10~5 cm/sec
or less)
17
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
(Bennett, 1996). The soil covers will also have an
upper surface with a slope to promote surface runoff
and minimize surface erosion.
The topsoil (vegetative soil layer) will be placed at
a minimum thickness of 3 inches and will have the
ability to survive and function with little or no
maintenance (Bennett, 1996). The surface slope will
also promote runoff and minimize surface erosion.
The soil cover sections could be easily repaired
should destruction of portions of the covers occur
through subsidence or cover intrusion be required
for future assessments or remedial actions. The soil
covers provide shielding for future waste/"hot spot"
removal, if required (Frye-O'Bryant et al., 1993).
"Hot spot" removal, in conjunction with placement
of the soil cover, is not being proposed at this time,
based on the following:
the nonhomogeneous nature and
disposition of the wastes in the ORWBG
(landfill-like)
"hot spot" source exact location is
unknown (within the waste unit)
current characterization technologies
would not provide location of "hot spot"
sources, and
if the BGC RFI/RI/FS process concludes
"hot spot" source and/or "waste retrievals"
are to be done, this interim action soil
cover will not preclude that action and will
provide additional shielding for the final
action remediation workers.
The existing groundwater monitoring wells within
the covered area will need to be extended to meet
the increased elevation or abandoned
(Frye-O'Bryant et al., 1993).
Visual inspection of the soil cover will be performed
by trained individuals at regular intervals and after
significant rainstorms. Any observed damage,
erosion, or subsidence will be repaired to conform
with the original soil cover contours.
This alternative could be implemented in
approximately 18 months. This timeframe is
required for the construction activities related to
erosion control, the sedimentation basin, and the soil
and vegetative covers. The time required for
preparation and regulatory approval of the IAPP,
Interim Action Record of Decision (IROD), and the
combined Remedial Design/Remedial Action Work
Plan/Remedial Design Report is independent of the
18 months required for construction.
The estimated capital cost for this alternative is $10
million for 76 acres. The cost estimate is based on
previous closure cover systems constructed at the
SRS and economic evaluation studies for closure
cover systems at hazardous waste units. The
estimated unit cost for this alternative is $3 per
square foot. The major subtasks associated with this
alternative are:
design and construction of the soil layer,
stormwater management system design,
construction, and permitting,
health and safety documentation
development, and
support and indirect tasks.
A combined Remedial Design/Remedial Action
Work Plan/Remedial Design Report will be
submitted for regulatory reviewin March 1996. This
combined document will provide additional details
regarding the soil cover.
This alternative was selected because it would (1)
decrease the stormwater infiltration rate and
contaminant migration to the groundwater, thus
minimizing future impacts to the groundwater, (2)
provide increased radiation shielding from buried
waste at the ground surface, (3) be easily repaired
should destruction of portions of the cover occur
through subsidence, and (4) provide versatility for
future characterization and removal activities. A
cross-section of this alternative is shown in Figure
5. The cross-section is representative of one of the
eight proposed soil cover sections.
18
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
New Surface Vegetation
2 Feet
WRn.
4 Feet ±
20 Feet ±
Existing Soil Cover
Over Waste Cetls
TopsoiJ
Note:
Drawing Not To Scale
This cross-section is representative of one of the eight proposed soil cover sections.
Figure 5. Old Radioactive Waste Burial Ground Soil Cover Configuration.
19
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Alternative 2 is an interim action and in no way
constitutes a final action for the ORWBG. A final
remedial action will be evaluated and conducted in
the future according to requirements of the FFA.
The solvent tanks remediation will be addressed at
that time.
X. Explanation of Significant Changes
There were no significant changes made to the
Interim Record of Decision based on the comments
received during the public comment period for the
Interim Action Proposed Plan. Six sets of comments
were received and are addressed in Appendix A.
However, the comments did not have an impact on
the soil cover preferred alternative decision. Some
of the text was revised to better clarify the
information presented.
20
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
XI. References
Bennett, J. T., 1996. Task Requirements and
Criteria: Old Radioactive Waste Burial Ground,
643-E Interim Soil Cover (U), Q-TC-E-00001,
Rev. 1, Westinghouse Savannah River Company,
Aiken, South Carolina.
DOE (U.S. Department of Energy), 1994. Public
Involvement, A Plan for the Savannah River Site.
Savannah River Operations Office, Aiken, South
Carolina.
EPA (U.S. Environmental Protection Agency),
1989. Guidance on Preparing SuperfundDecision
Documents. Office of Solid Waste andEmergency
Response - OSWER Directive 9355.3-02.
EPA (U.S. Environmental Protection Agency),
1991. Guide to Developing Superfund No Action,
Interim Action, and Contingency Remedy RODs.
Office of Solid Waste and Emergency Response -
OSWER Directive 9355.3-02FS-3.
FFA, 1993. Federal Facility Agreement for the
Savannah River Site, Administrative Docket No.
89-05-FF, (Effective Date: August 16, 1993).
Frye-O'Bryant, R C., T. F. Gaughan, S. R
McMullin, and M. G. Serrato, 1993. Evaluation of
Temporary Cover Configurations for the Old
Radioactive Burial Ground (U),
WSRC-RP-93-1154, Westinghouse Savannah
River Company, Aiken, South Carolina.
Serrato, M. G, 1994. Old Burial Ground Soil Cover
- HELP Model Evaluation (U),
WSRC-RP-94-1128, Westinghouse Savannah
River Company, Aiken, South Carolina.
WSRC (Westinghouse Savannah River Company),
1994. RFI/RI Work Plan for the Burial Ground
Complex (U), WSRC-RP-90-1140, Rev. 2,
Westinghouse
Savannah River Company, Aiken, South Carolina.
WSRC (Westinghouse Savannah River Company),
1995. Interim Action Proposed Plan for the Old
Radioactive Waste Disposal Facility (643-E) (U),
WSRC-RP94-1225, Rev. 1, Westinghouse
Savannah River Company, Aiken, South Carolina.
21
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
APPENDIX A
RESPONSIVENESS SUMMARY
22
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Responsiveness Summary
The public comment period for the Interim Action Proposed Plan (IAPP) for the Old Radioactive Waste Burial
Ground (ORWBG) began on February 2, 1996 and ended on March 2, 1996. A public meeting was held on
February 27, 1996. Six sets of comments were received on this proposed interim action. Specific comments and
responses are found below. The comments are italicized and the responses are bolded.
Public Comments
Memo, dated February 22, 1996
To: Ms. Mary A. Flora
Public Involvement
From: W. Lee Poe, Jr., Private Citizen
Aiken, SC
Subject: Interim Action Proposed Plan for the Old Radioactive Waste Burial Ground (643-G)
I would like to offer several comments on Revision 1 of WSRC-RP-94-1225.1 read the Interim Action Plan and
found it to be quite readable but filled with unnecessary abbreviations (all defined in the List of Acronyms).
In view of these comments and perhaps a fundamental error in water percolation rate (see comment S-7) affecting
the preferred alternative, I would like to have the opportunity to review the revised report before the decision
is reached to implement the interim action.
I have grouped my comments into two groups; they are General Comments and Specific Comments. They are
as follows:
General Comments
G-l) The report needs information stating what the risk is. Section I. V.B makes the point that storm water
infiltration is leaching organics, metals, and radionuclides from the buried waste. A small amount of
information is included on the groundwater concentrations of some of these materials but nowhere could
I find anything that talks about the significance of these materials in the groundwater and its danger to
the public. Buried in Table 2 is the statement that the risk to the off site population is minimal. I saw no
other mention of the level of risk in the Interim Action. The analysis is, in my judgment, inadequate. The
analysis should identify what radionuclides, organics, and metals are released from the burial grounds
to the creek and reach the public and what the consequences to the public are. Only after this
information is available can a proper decision be reached.
23
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Response to G-l:
A baseline risk assessment (BRA) for the ORWBG has not yet been completed. A Burial Ground
Complex BRA (that will include the ORWBG) will be completed in November 1997 and will
provide the information about risk that you are requesting. Please keep in mind that this proposed
action is an interim action; the intent of the soil cover is to limit the migration of contamination
into the groundwater in the short term while more information is being acquired and the final
solution is being developed.
G-2) If the risk is minimal (as stated in Table 2) and further evaluation is being conducted for other parts of
the Burial Ground Complex, I believe that the No-Action Alternative is the appropriate to take for this
Interim Action. (I offer this conclusion with some concern because I do not believe that the risk is
minimal as stated.) I do not believe that DOE should spend 10 million dollars for an interim action
where the risk is minimal. I recognize that WSRC, DOE, SCDHEC, and EPA have all reviewed this issue
and are in agreement. I think they must be caught up in administrative details that direct some action
be taken. The No Action Alternative is action.
Response to G-2:
Based on information from groundwater and surface water monitoring, the current risk to the
offsite public is minimal. It is the potential future risk that is posed by the inventory of wastes in
the burial ground that is being addressed. At this time, the No Action alternative is a valid option
that has been seriously considered. However, because the development of a final remedy will take
time, it seems prudent to take some action that will minimize additional groundwater
contamination and yet not interfere with our ability to undertake future actions.
G-3) The report contains no information on how releases from the groundwater to the streams and the river
will be affected by the proposed action. This information should be included.
Response to G-3:
The soil cover will minimize the continued migration of contamination to the groundwater and
ultimately to the surface streams, but will not substantially affect the contamination which already
exists in the groundwater and surface streams. Detailed information about the groundwater at the
Burial Ground Complex is contained in the RCRA Part B permit application for the MWMF.
Work is in progress toward the development of a RCRA groundwater corrective action plan for
the plume of contamination at the ORWBG.
G-4) Applicable or Relevant and Appropriate Requirements (ARAR) are stated to be an evaluation criteria.
In Table 1, ARAR are identified and I see no requirement that specifically relate to differences to the
alternatives. Only high level DOE Orders and a single SC regulation are listed; those things that will
and must be done anyway like protect the workers and public. Table 2 says that no differences between
alternatives exist for this criteria. Recognizing this when the report was prepared, this criteria should
have been deleted. It didn 't help make the decision.
24
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
I would like to quote a finding of the National Research Council related to the Hanford Waste Tank
Program since it must be applicable here. The NRC found that DOE and the regulators establish
"priorities that are driven by narrow interpretations of regulations rather than regulation's purpose of
protecting the public health and environment. " Quote is from Barriers to Science - Technical
Management of the Department of Energy Environmental Remediation Program.
Response to G-4:
The ARARs listed in Table 1 were based on what SRS believed to be the applicable ARARs for this
interim action after reviewing the list of statues and regulations shown on page 12 of the ORWBG
IAPP. The ARAR section in Table 2 is required by CERCLA. Although, it may not have assisted
in the decision-making process, it should be shown in order to indicate that the ARARs were
reviewed during the process of selecting the remedial alternatives.
G-5) Section IV.D is so general that it is not useful to this Interim Action report. The only useful portion is the
last part (Description of the Preferred Alternative) which is redundant but serves as a good summary.
I suggest making it into an executive summary.
Response to G-5:
Section IV.D serves as a summary of the information on the preferred alternative. It discusses the
evaluation of the alternatives against the nine criteria established under CERCLA. The section also
provides a synopsis of the applicable information on the preferred alternative. The Interim Action
Proposed Plan was developed in accordance with CERCLA guidance on proposed plans and
records of decision development.
G-6) Throughout the report the No-Action alternative is referred to as not requiring actions. In reality the No-
Action Alternative does require actions to maintain the burial grounds. These sections should be
expanded to show what is being done to maintain the burial ground. Table 2 is particularly objectionable
on this point.
Response to G-6:
The descriptions of alternatives in the IAPP were intended to contrast the capital costs, actions,
and expected results of the three alternatives, beyond current ongoing ORWBG maintenance
activities. Table 2 was intended to present a concise comparison of the three alternatives versus the
nine evaluation criteria established by CERCLA. Ongoing maintenance activities in the ORWBG
include regular grass mowing, monthly inspections for subsidence, and weekly inspections of the
drainage system for erosion and sediment control. These maintenance activities would continue
as a part of all three alternatives described in the IAPP. Clarifying language will be incorporated
into the IROD to make this clearer.
Specific Comments
S-l) In Figure 1, the Burial Ground arrow points to a blank part of the Site. I know where the burial ground
is located but others will not.
25
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Response to S-l:
Figure 1 was revised to better show the location of the Burial Ground.
S-2) Figure 2 is illegible. It needs subtitles to show where the parts that are discussed in Section I are located.
The Legend is of no help - all areas look alike.
Response to S-2:
Figure 2 was revised to ensure that the reader can see where the parts that are discussed in Section
I are located. The Legend was also revised to make it easier to understand.
S-3) Section III last sentence talks about soil cover. Add statement that it will be maintained. It was discussed
later but it would help the reader to see it here as well.
Response to S-3:
A statement was added to the Scope and Role of Operable Unit or Response Action Within the Site
Strategy section of the Interim Record of Decision (IROD) to show that the soil cover will be
maintained.
S-4) Figure 3 needs to be improved to show the relevance for this Interim Action for the ORWBG. The test
says this figure shows the CERCLA activities. Icouldn 't see any CERCLA on the figure. The text and the
figure do not support each other.
Response to S-4:
The referenced figure was improved for inclusion in the IROD for the ORWBG. Additional
headers were added to designate RCRA and CERCLA (FFA) activities. The purpose of the figure
is to show all of the RCRA and CERCLA (FFA) activities at the Burial Ground Complex and their
relative timeframe.
S-5) SectionlV.A (Unit Description andLocation section) should also talkabout the proximity of streams that
serve to transport effluents to off site personnel.
Response to S-5:
A description of the proximity of streams was included in the IROD (see Section I). The plume of
groundwater contamination from the ORWBG seeps into the old F Area effluent stream which
flows into Four Mile Creek which in turn flows into the Savannah River. Levels of tritium do
exceed drinking water standards in Four Mile Creek.
S-6) Initial paragraph on page 10 says that the old solvent tanks (in the middle of the ORWBG) will not be
covered in the proposed action. One would logically ask why not? We don't want water flowing past
them either. I could find no reason for not covering them when you are covering the rest of the OR WBG.
It would probably be less expensive to cover it all at one time.
26
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Response to S-6:
The original design included coverage of the ORWBG solvent tanks; however, the assumption was
that stabilization of the tanks would be completed prior to the start of soil cover construction. In
further examination of the ORWBG solvent tank remediation schedule, it was determined that
tank stabilization would not be initiated until late 1997. These tanks must be stabilized prior to
placement of the soil cover because of their questionable structural integrity. The current design
for the soil cover is such that the area left uncovered (administrative area and solvent tanks) will
drain properly.
The ORWBG solvent tank stabilization/ remediation would be completed after the soil cover has
been placed, but prior to the initiation of the Burial Ground Complex final action. Therefore, the
solvent tanks have been omitted as a part of the soil cover interim action and will be pursued as
a separate action.
S-7) The first paragraph of Section IV.B is unclear or inaccurate. It says that the current soil cover reduces
the infiltration by 45% to 2.1 inches percolation. The new soil cover will decrease infiltration to 13%.
The paragraph goes on to say that this equates to an infiltration rate o/0.05 inches of water. Using these
values, I see no way of getting a 0.05 inch value. For example if the 13% value is of the current
infiltration the new percolation rate would be 2.1 * 0.13 = 0.27" infiltration. If the 13% of the rainfall,
the infiltration rate would be significantly more. Please correct the information. It may make a difference
on the alternative selected.
Response to S-7:
The text in the IROD has been revised for clarity and accuracy.
S-8) The subsection of IV.B on Constituents of Concern would be improved considerable by comparing these
pollutants to health standards and to those found in commercial landfills. How much organics and
metals are found in say the Aiken Landfill that was abandoned 10 or so years ago. This would help
establish how bad the problem is and how this ORWBG compares to other burial grounds or landfills.
Response to S-8:
Levels of contaminants in the groundwater plume at the ORWBG are compared to levels of the
same constituents at the SRS sanitary landfill and the A/M Area plume in the table below.
Groundwater remediation programs are in place at both the landfill and the A/M Area.
Contamination in A/M area is from past discharge of non-radioactive waste solvents to an unlined
basin and is representative of pollution from a non-nuclear industrial facility. Contamination at
the SRS sanitary landfill results from the burial of trash that would be typical of municipal landfill
waste.
27
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
coc
1 , 1 -Dichloroethy lene
Carbon tetrachloride
Chloroform
Lead
Mercury
Tetrachloroethylene
Trichloroethylene
Tritium
Gross Alpha
Uranium-233/234
Uranium-238
Carbon- 14
Units
ug/1
ug/1
ug/1
ug/1
ug/1
ug/1
ug/1
pCi/1
pCi/1
pCi/1
pCi/1
nCi/1
MCLs
7
5
100
15
2
5
5
20,000
15
alpha =15
alpha =15
-
ORWBG
Maximum
24
5.5
191
82
4.11
304
339
286,000,000
132
108
231
4.900
AIM Area
Maximum
32
-
-
51
-
65,000
21,000
-
-
-
-
-
Sanitary
Landfill
Maximum
9
-
-
65
2.54
41
62
130
35
-
-
-
MCL- Federal Maximum Concentration Level (drinking water standard)
S-9) The second paragraph on page 14 raises the possibility of abandoning the old wells in the burial ground.
Don't abandon them. They are historically important for comparison and should continue to be used to study
the condition in the burial ground. This is doubly important since none of the wells show a uniform water
contamination indicating that we have a non-uniform contamination pattern under these burial grounds.
Response to S-9:
The monitoring wells within the boundary of the ORWBG have been abandoned in order to facilitate
construction activities in support of the placement of a soil cover. However, a network of wells monitor
both groundwater quality at the perimeter of the burial ground and the plumes which originate from
the Burial Ground Complex. This monitoring network consists of over one hundred wells which
monitor three aquifer zones in accordance with an approved RCRA groundwater sampling and
analysis program. Historical data from the water table wells within the ORWBG, in conjunction with
the RCRA monitoring network and groundwater samples collected by direct push technology (a
geologic sampling tool that is pushed into the ground to collect groundwater samples), provide
sufficient groundwater data to fully characterize groundwater at the Burial Ground Complex.
S-10) Section IV.D seems to have no use as written. See comment G-5.
Response to S-10:
See response to comment G-5.
S-ll) The first sentence of the last paragraph, page 17, is internally redundant. If it is an interim action by its
definition it is not a final action. The last part does not need to be said.
28
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Response to S-ll:
SRS realizes that the first sentence of the last paragraph on page 17 is internally redundant. However,
the sentence was added so that there would be no confusion in thinking that this was the final action
for the ORWBG.
S-12) Table 2 needs some work to be the basis for the decision to use Alternative 2. I would like to offer several
comments on how I think the table could be made more useful. They are:
Comment G-6, above, talks to the need to better define the actions associated with the No Action
Alternative.
In the row on protection of the health and safety and of the environment, amplify the levels of protection
provided by the various alternatives with technical judgments and how these levels of protection are
provided. As written Alternatives 2 and 3 are simply "trust me" statements with no ability to
independently verify.
Delete ARAR and Long-term effectiveness and permanence from the table. All alternatives are the same.
If it is necessary to be included then, do it with a footnote.
Reduction oftoxicities, mobility, etc. could be improved by using some numbers.
Short-term effectiveness needs to discuss the amount oforganics, metals, and radionuclides in the water
table and some estimate of those transported to the groundwater. This should be followed with
information on the rate of discharge to the creek for the three alternatives.
Update the State Acceptance row of data. Based on Section II, they have approved the Interim Action.
If you or any of the technical people associated with making the revisions requested have any questions, please call
me at (803) 642-7287.
Response to S-12:
1st bullet: See the response to general comment G-6, above.
2nd, 4th, and 5th bullets: The comments all suggest additional quantifying data for Table 2 is currently
not available. Characterization activities for the Burial Ground Complex are underway and should
provide the hard data needed for the decisions on the final action, which will be presented in a future
Proposed Plan. The scope of this interim action is limited in nature and is only focused on reducing
stormwater infiltration through the ORWBG waste trenches. SRS has high confidence that the result
will be decreased contaminant transport. The data necessary to quantify the specific levels of reduction
is not yet available.
3rd bullet: ARARs and long-term effectiveness are required to be reviewed for all actions by the
CERCLA. SRS realizes that these alternatives are not really applicable for an interim action and the
information in Table 2 is repetitive. SRS believes that the information should remain in the table.
6th bullet: SCDHEC and EPA have not approved the Interim Action. Section II indicates that
SCDHEC and EPA (along with DOE) are soliciting public review and comment on the "proposed" plan
for this interim action. It further indicates that
29
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
DOE, SCDHEC, and EPA will select a remedial action following the public comment period. This
decision will be documented in the Record of Decision (ROD) for this interim action. The ROD will
include a Responsiveness Summary which addresses comments and concerns received during the public
comment period.
30
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Comments from the February 27, 1996 Public Meeting as recorded in the ORWBG Public Meeting transcript.
1) Why wasn 't waste removal considered as an alternative?
Response to 1:
Much more knowledge is necessary before serious consideration is given to removing radioactive items
from the ORWBG. Investigation activities are ongoing at the BGC which may provide that type of
knowledge. In the interim, rainwater infiltration through the buried waste can be addressed without
hampering the ability to gain more specific knowledge through investigation/assessment activities at
the BGC.
2) Why aren 't the solvent tanks being addressed at this time?
Response to 2:
The original design included coverage of the ORWBG solvent tanks; however, the assumption was that
stabilization of the tanks would be completed prior to the start of soil cover construction. In further
examination of the ORWBG solvent tank remediation schedule, it was determined that tank
stabilization would not be initiated until late 1997. These tanks must be stabilized prior to placement
of soil cover because of their questionable structural integrity. The current design for the soil cover is
such that the area left uncovered (administrative area and solvent tanks) will drain properly.
The ORWBG solvent tank stabilization/ remediation would be completed after the soil cover has been
placed, but prior to the initiation of the Burial Ground Complex final action. Therefore, it is
recommended that the solvent tanks be omitted as a part of the soil cover interim action and be
pursued as a separate action.
3) Are the tanks full of solvents; if not, where is the solvent?
Response to 3:
These are old empty solvent tanks that are buried. These old underground tanks do not meet the
current standards for storage of organics, much like at a gas station. New tanks were constructed to
meet all the current standards. The solvents that were in the old tanks were transferred into the new
tanks. Ultimately, the plan is to incinerate the solvents in the Consolidated Incineration Facility when
it becomes operational.
4) Is the final action going to stop more percolation of the rainwater leaching through the area more so than
this interim action?
Response to 4:
The final action will be determined when more information about the nature of what is buried in the
ORWBG and what impact it is having on the environment has
31
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
been established. The objective of the remedial process is to establish goals for a cleanup action. The
goal of this action is limited and focused on reduced infiltration. This is a near-term goal that will have
environmental benefit while SRS is in the process of developing the final goals.
5) Do you know exactly what and where everything is buried in the ORWBG?
Response to 5:
Records exist which give two dimensional locations for waste burials. These records also contain waste
type and quantity for each burial.
6) Do you have certain items that should be dug up and removed from the old burial site?
Response to 6:
See Response to 1.
7) Why was the Mixed Waste Management Facility closed in 1991 ?
Response to 7:
The Mixed Waste Management Facility (MWMF), a portion of the Burial Ground Complex, was
addressed under the RCRA regulations and was closed with a RCRA cap. Mixed waste refers to waste
that contains both radioactive and hazardous components. The MWMF was permitted for radioactive,
but not hazardous waste. In 1986, SRS determined that the facility should be closed because the waste
it received contained some materials - such as lead, silver, cadmium, and waste oils - classified as mixed
waste under RCRA. Through a settlement agreement with the South Carolina Department of Health
and Environmental Control (SCDHEC), the MWMF cap closure was completed in 1991.
8) What is RCRA?
Response to 8:
RCRA stands for the Resource Conversation and Recovery Act. RCRA is a set of regulations which
deal with the identification, management, and disposal of hazardous wastes. RCRA includes provisions
for the permitting of treatment, storage, and disposal facilities.
9) What materials will be used to create the cover system over the ORWBG?
Response to 9:
The cover system for the interim action is going to be a large quantity of sandy clay soil. This soil cover
will be adequate to reach the goal of this interim action (reduce infiltration).
10) Is this actually a short-term solution?
32
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Response to 10:
This is the appropriate time to put something in place to reduce infiltration. It is a short-term
action to reduce infiltration while full characterization of the site continues and the long-term
solution is developed. This interim action will reduce the infiltration, but will not preclude going
in and characterizing the waste for potential removal in the future.
If the short-term solution was to place a RCRA cap, such as that at the Mixed Waste Management
Facility, on the ORWBG, then infiltration is mitigated. However, if characterization or excavation
activities occur, the cap is torn up and ruined. The cap would be very costly to fix.
11) How long will this interim action be in place prior to the final action implementation?
Response to 11:
The schedule is to get the final remedial decision started at this site by the year 2001. So short-term
is the five years that this action will be in place. However, SRS could have gone through the entire
remedial process of characterizing all the contaminants toward a final remedy on the traditional
path, but that would continue to allow contamination to migrate to the groundwater while
evaluation takes place. The scope of the interim action is a soil cover over the ORWBG. This will
allow for continued characterization and selection of a final remedy, while protecting the
groundwater in the interim.
12) Is placement of a soil cover over the ORWBG predisposing or eliminating future options?
Response to 12:
All of the options will be evaluated to see if they're viable and protective. There will be a very
detailed evaluation for the final remedy. It will have to be based on the technical as well as the
protectiveness criteria. There will be a very stringent comparison of remedies and whether or not
they're protective, cost- effective, and meet all of the nine criteria of CERCLA.
An innovative technology may be appropriate; however, not enough information is known at this
time to proceed with final action. This interim action does not preclude any future options,
including identification and removal of hot spots. This interim action is for mitigating the
contamination pathway to groundwater. By reducing groundwater contamination now, there will
be less polluted groundwater to deal with in the future.
13) Why not look at less costly alternatives like paving the ORWBG?
Response to 13:
A paved area is a very impermeable surface layer. There would be more rainwater runoff. The soil
cover acts to absorb some of the water initially; and, then it will release it over time so as not to
have a very large flow of water all at one time. An asphalt type cover system or a tarp would
require much more money to be spent on
33
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
the drainage system. SRS would need to build larger sedimentation basins and collection systems
to carry the stormwater away. Therefore, the overall cost of the proposed soil cover would be in
the same range with some of those alternatives.
The ORWBG currently is not well drained. Although measures have been taken by SRS Solid
Waste Operations over the years to improve the situation, the problem remains that the ORWBG
is essentially a large, flat area with undersized ditches and culverts. Any interim action that seeks
to reduce infiltration will increase stormwater runoff. Therefore, regardless of the configuration
chosen (soil cover, RCRA cap, tarp cover, or other), if the interim action decreases infiltration
(thereby increasing runoff), the same magnitude of earth moving will have to occur to achieve a
3%-5% finished slope to promote proper drainage. Additionally, an upgraded stormwater
management system, with larger ditches/piping/culverts will be required, regardless of the chosen
option. Therefore a certain "earth moving/drainage improvement cost baseline" is established for
any interim action alternative which reduces infiltration.
The soil cover alternative is a technically simple alternative to design and construct which does not
interfere with future characterization or waste removal activities. The tarp cover alternative would
involve essentially the same amount of earth moving and drainage improvement work, plus about
65 acres of the tarp cover to buy, place, and maintain. The permeability of such a tarp cover
system would be lower, but the added value of this was judged to be marginal when balanced
against the initial and recurring costs of such a large tarp area. For this reason, the tarp cover
system was not considered as an alternative in the IAPP.
14) The waste added to the burial ground will become contaminated just like the topsoil is now. So the more
you put on it, the more you 're going to have to recover later on. You have to understand contamination.
And it can purge upward as well as go out into your groundwater. It can purge and come up. So you 're
not going to stop it. I mean stop it temporarily and this is what the interim action is going to do. If you
understand contamination, if you 've ever been around contamination you 'II know what I 'm talking
about.
Response to 14:
Current waste disposal practices have changed The practices that were in place back during that
period of time were not as stringent as our current practices for disposal of waste. Today, SRS no
longer buries radioactive waste. The waste is volume reduced and then placed in large concrete
vaults built by construction.
15) Is the TRU waste placed in vaults?
Response to 15:
The TRU waste is not put in vaults. It's currently stored in above-ground storage.
16) It looks like a good interim action but there are a couple of questions that I have. First off, one of the
things that we know about adding a soil cover is that it raises groundwater levels. Have you taken that
into account and how will you deal with that? Will that be a factor or will that be a concern?
34
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Response to 16:
Based on experience with capping the MWMF and the F and H Seepage Basins, SRS expects the
groundwater levels at the ORWBG to fall slightly in response to the soil cover. This is because the
primary input of water at the ORWBG is from rainwater and the soil cover will minimize the
amount of rainwater infiltration. In addition, the water table is approximately 50 feet below land
surface at the ORWBG. The waste is buried at a depth of 20 feet. This provides a 30 feet buffer
zone between the waste and the groundwater. Small fluctuations in groundwater elevation will
have no impact on the buried wastes.
17) And what about the underlying soil surface that now exists? It has been compacted, is that not right?
Response to 17:
It has been compacted. The settlement that has occurred over the years has been filled in and the
soil has been compacted over time as well.
18) What kind of plant cover are you planting on this?
Response to 18:
SRS will be using shallow-rooted local grasses.
19) I'm a little concerned about the soil cover itself. It's hard to tell since we don't know what the final
action is going to be whether or not the soil cover will interact and cause us problems with the final
action. I think some of the speakers have already raised that as an issue. I think it's a good question. At
this time can you give us a guess, your best judgment on what the final action will be?
Response to 19:
If SRS were to do a RCRA cap down the road on the ORWBG, the soil cover SRS is putting in
place would help toward the foundation. On the other hand, if SRS does an excavation type option,
there will be a lot of void spaces in there after the waste is removed. This soil cover would then be
utilized to help backfill those areas so that a nice sloped area would exist at the ORWBG. Looking
at those two extremes, capping or excavation, this soil cover would help in either instance.
20) How much more expensive do you think the final action will be as a result of this action?
Response to 20:
Since SRS is only in the characterization phase for the Burial Ground Complex, it is premature
to presume what the final action will be. Without knowledge of the final action, cost comparisons
are impossible at this time.
21) Have you got any preliminary estimates at this time?
35
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Response to 21:
No preliminary estimates have been done at this time.
22) I look at the sketch here and I notice that transuranic waste have been buried in this area; is that
correct?
Response to 22:
That's correct.
23) And right now we really don't have very good, if any, characterization data about what we buried. And
what concerns me is that if we put this kind of a load, it looks like an enormous load by putting all this
soil over the ORWBG. Do we have the potential to collapse these boxes or steel cans or the things they
were put? Are we risking a criticality? But if we have no idea what's buried out there, that's what you 're
telling me, we don't have characterization, we don't have records, we don't know where what is buried.
And you 're going to go press this material; is that correct?
Response to 23:
The instability and the potential for voids because of the material in the trenches have been
thoroughly evaluated from an engineering design standpoint.
Many of the areas of the ORWBG have experienced significant subsidence (settling) over the years.
These areas have been backfilled with soil, and the entire ORWBG is visually inspected every
month to identify any areas that may require may require additional backfilling. For this reason
SRS believes that many of the areas that would experience the greatest amount of subsidence have
already been partially stabilized. However, SRS does anticipate that placement of the soil cover
will cause further subsidence during and after construction. The construction subcontractor
selected for this project will be experienced with landfill/buried waste site remediation. Prior to
placing the soil cover, the contractor will stabilize the ground with a vibratory roller; any soft spots
that appear will be backfilled prior to soil cover placement. Additionally, SRS plans a construction
sequence and strategy with the contractor that will reduce the potential for subsidence during
construction After the soil cover has been constructed, the ORWBG will continue to receive
monthly inspections, and any subsiding or eroding areas will be repaired.
SRS further believes that the buried waste in the ORWBG trenches remains relatively contained
by the surrounding soil. Also, the waste probably remains in a damp or moist condition due to the
stormwater that percolates through the ORWBG. For these reasons, SRS does not believe there
is a significant risk of airborne contamination due to collapsing voids in the waste trenches. In
addition, the TRU wastes were encapsulated in concrete pours so criticality is not an issue.
Records exist which provide two dimensional locations for waste burials. These records also
contain waste type and quantity.
24) Is there a way that these could be E-mailed or do they have to be sent on paper?
36
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Response to 24:
Yes, comments can be E-mailed. Mary can be reached at the following E-mail address:
MARY.FLORA @ SRS.GOV.
25) I think this way of approaching the burial ground, which I think everybody that is familiar with it
recognizes it's actually one of the more complicated environmental remediation challenges at Savannah
River Site. I think this is a very good approach. The notion that we 're sitting down together, not trying
for the final solution and just declare it done with, not letting the unanswered questions become an
excuse for just delay and continued migration and contaminants, but instead trying to come up with a
series of steps that will help you to both better control the problem and better come up with answers for
the questions that have not been asked or answered tonight is really commendable and hopefully a sign
of the way more of these decisions can be approached in the future.
Response to 25:
There is no response required since this was a statement of support.
37
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Memo, dated February 28, 1996
To: Mary Flora, Manager
Environmental Management Public Involvement
From: Douglas E. Wyatt, Private Citizen
Aiken, SC
I would like the following two questions entered into the Public Record for the Old Radioactive Waste Burial
Ground Interim Action Proposed Plan:
1. In considering the remedial alternatives, the "tarp " cover was not mentioned, therefore I assume that
it was not considered to be viable. What supporting construction documentation on engineering
constraints and cost is available to support or disqualify the "tarp " cover and is it available for public
review?
Response to #1:
Using tarps to cover smaller buried waste sites on an interim basis is a strategy which has been
used successfully at other DOE sites. This option, although not summarized in the IAPP, was
included (30 mil High Density Polyethylene-Flexible Membrane Liner) in a 1993 report which
evaluated temporary cover configurations for the ORWBG (WSRC-RP-93-1154, referenced in the
IAPP). This report concluded that a soil cover was the preferred alternative.
The ORWBG currently is not well drained. Although measures have been taken by SRS Solid
Waste Operations over the years to improve the situation, the problem remains that the ORWBG
is essentially a large, flat area with undersized ditches and culverts. Any interim action that seeks
to reduce infiltration will increase stormwater runoff. Therefore, regardless of the configuration
chosen (soil cover, RCRA cap, tarp cover, or other), if the interim action decreases infiltration
(thereby increasing runoff), the same magnitude of earth moving will have to occur to achieve a
3%-5% finished slope to promote proper drainage. Additionally, an upgraded stormwater
management system, with larger ditches/piping/culverts will be required, regardless of the chosen
option. Therefore a certain "earth moving/drainage improvement cost baseline" is established for
any interim action alternative which reduces infiltration.
The soil cover alternative is a technically simple alternative to design and construct which does not
interfere with future characterization or waste removal activities. The tarp cover alternative would
involve essentially the same amount of earth moving and drainage improvement work, plus about
65 acres of the tarp cover to buy, place, and maintain. The permeability of such a tarp cover
system would be lower, but the added value of this was judged to be marginal when balanced
against the initial and recurring costs of such a large tarp area. For this reason, the tarp cover
system was not considered as an alternative in the IAPP.
38
-------
Interim Record of Decision for the
Old Radioactive Waste Burial Ground (643-E)
Savannah River Site
WSRC-RP-96-102
Revision 0
March 1996
2. In the Gross Alpha measurements made for ORWBG groundwater, what are the values for uranium,
plutonium, neptunium, and iodine isotope speciation and how do their concentrations compare over time
and to health based risk standards?
I look forward to your support and consideration.
Response to #2:
Of the radioisotopes mentioned only Uranium isotopes (U-233/234 and U-238) have been identified
as Constituents of Concern (COCs) in the groundwater at the ORWBG. COCs are determined
through a rigorous process of statistical and nonstatistical analysis of monitoring data in
accordance with RCRA groundwater regulations. The goal of this analysis is to identify
contaminants which require continued monitoring and potentially groundwater remediation.
Work towards the development of a RCRA Corrective Action Plan to address groundwater
contamination at the ORWBG is underway.
The results of the COC development process and documentation of the analysis will be submitted
to SCDHEC in the next revision to the RCRA Part B permit application for the MWMF this
summer. Examination of data indicates that the occurrence of elevated levels of these contaminants
is sporadic and that there does not appear to be a trend that is either increasing or decreasing with
time. Summary statistics for these uranium isotopes are provided below.
Constituent
Uranium-
233/234
Uranium-238
Units
pCi/1
pCi/1
Number of
Measurements
311
322
Average
1.29
1.66
Maximum
108
231
Drinking
Water
Standard
Sum of all
alpha < 15
pCi/1
Sum of all
alpha < 15
pCi/1
39
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Memo, dated February 29, 1996
To: Mr. Jeff Crane
Federal Facilities Branch
U. S. EPA, Region IV
From: Tim Connor, Associate Director
Energy Research Foundation
RE: Comments on WSRC-RP-94-1225, Rev. 1, Interim Action Proposed Plan for the Old Radioactive Waste
Burial Ground (ORWBG)
Of the three interim action alternatives identified in the above document for the Old Radioactive Waste Burial
Ground, Energy Research Foundation believes Alternative #2Placement of a Soil Coverto be the most
prudent. Our support for this alternative is based on two considerations.
1) Given the existing contamination of both groundwater and surface water causedby rainwater infiltration
into and through the waste trenches at the ORWBG, it is important to take short term actions that can
reduce the infiltration and at least slow the movement of contaminants into and through the
groundwater.
2) Given the large inventories of both toxic chemicals and long-lived radioactive materials at the ORWBG
it is essential that every reasonable effort be made to reduce the potential for future migration as a result
of continued leaching and groundwater transport, the potential for uptake through surface vegetation
or animal burrowing, and the potential for direct exposure resulting from inadvertent excavation or
intrusion into the waste itself. Such "reasonable " efforts may include selective removals or additional
efforts to isolate and/or stabilize certain waste constituents. The interim action should not inhibit with
the investigations necessary to aid decisions about the feasibility of additional remediation efforts, nor
be an obstacle to the remedial actions themselves.
ERF's concern about Alternative #3Placement of a RCRA-like Capis based on the latter consideration. Not
only would the RCRA-like cap inhibit continued monitoring and investigations of the waste trenches, the added
expense of the cap would at least create the appearance of a final remedy. Moreover, because it is plausible that
actions needed to support a final remedy and the remedy itself would involve at least partial destruction of the
RCRA-like cap, the existence of the RCRA-like cap could, by itself, impose a bias on these decisions.
ERF's support for an interim action is based on our view that the evidence and technical analysis developed to
date does not support any decision about a final remedy. The evidence and technical analysis needed to support
a final remedial action decision will need to address several issues that are not covered in the Interim Action
Proposed Plan documentation. Among these issues are: best estimates of chemical and radionuclide inventories
at the ORWBG, a thorough identification of waste categories and forms, identification of the location of the
burials, the adequacy of the ORWBG site for the permanent disposal of long-lived wastes, the technical
feasibility for the removal or stabilization of long-lived chemical and radioactive waste forms (i.e., certain
transuranic wastes, filters containing long-lived radionuclides such as iodine-129,
40
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
mercury in plastic bottles, stainless steel vessels containing long-lived carbon-14 in deionizer resins),
estimates of occupational exposures under specified removal or stabilization activities, and cost estimates
associated with various options under the final plan.
Clearly, the decision about a final remedial action for the ORWBG will have to be made within the context
of a strategy for the Burial Ground Complex as a whole. This strategy will not only have to consider
possible future site uses up to and beyond a presumed institutional control period, but also address
long-term environmental quality issues associated with affected groundwater (most notably the Congaree
aquifer) and affected surface streams (Four Mile Creek and Upper Three Runs Creek). As yet, there is no
strategy and supporting analysis that addresses these issues.
Finally, the discussion of the scope and role of the proposed response action within the site strategy would
be improved by a more detailed discussion on the progress on the Burial Ground Complex Field
Investigation Plan and how it relates to issues that are expected to be addressed in the RFI/RI/BRA phase
with respect to the ORWBG. Included in this discussion should be some indication of how relevant public
comments received during this interim action process will be transferred to the decision making process
on a final remedial action for the ORWBG.
Response:
Implementation of the Field Investigation Plan (FIP) is well underway. Characterization of the
plume at the ORWBG has been completed in accordance with the FIP and submitted to
SCDHEC in revision 3 to the RCRA Part B permit application for the MWMF.
Groundwater sampling via Cone Penetrometer hydrocone and Hydropunch to delineate the
vertical and lateral extent of the three burial ground plumes has been completed. Twenty three
(23) new wells have been installed to monitor groundwater flow and contamination in the
vicinity of the groundwater divide. Soil, wetlands, and stream sampling are in progress. Data
evaluation is ongoing.
Additional coring and water sampling to gather information in data sparse areas around the
Burial Ground Complex are planned for later this year. This data will be used to improve the
ability of groundwater models to predict future contaminant migration. This data will also
improve our ability to model the interaction effects of multiple caps and groundwater
remediation projects in the vicinity of the Burial Ground Complex. Pumping tests to gain
information which will support corrective action design are being planned and are scheduled
for execution in FY 1997.
The results of the BGC FIP characterization will be used to develop the BGC RCRA Facility
Investigation/Remedial Investigation/Baseline Risk Assessment (RFI/RI/BRA) Report. The
results of the RFI/RI/BRA will be used to develop the final remedial alternatives for the BGC
including the ORWBG.
41
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Public Comment Card, postmarked March 2, 1996
To: Mary Flora
From: L. Hanks, Public Citizen
North Augusta, SC
/ never did hear what is growing on top of the ORWBG now. Grass on a dome field or like a football field
does the best with water. The best way to solve the problem is to dig it up, check the damage, and reinstall
waste in new groundwater proof facilities. That's called clean-up.
Response to comment:
The ORWBG is currently covered by a mixture of shallow-rooted local grasses, not unlike a
residential lawn. This grass cover receives regular mowing. Some areas of the ORWBG are
"mounded" to promote drainage, but the overall topography of the area is generally that of
level land. Future investigation/assessment activities for the Burial Ground Complex,
including the ORWBG, will determine the best way to proceed with the final remedial
alternative for the ORWBG. Suggestions such as yours will be considered for the final
remedial alternative.
42
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Memorandum, dated March 4, 1996
To: Anne Roe, SW&ER Public Involvement
From: George Minot, Public Citizen
Hilton Head Island, SC
RE: Old Radioactive Waste Burial Ground IAPP
Remedial Alternatives for F- & H-Area Groundwater Operable Unit
First, thank you for your responsiveness to my January 31st request for information regarding the IAPP
for ORWBG.
General Response:
The supplemental information that was provided at your request was excerpted from several
documents. Figures and tables from various sources were chosen in an attempt to provide
specific answers to your questions. The questions posed in your most recent letter indicate that
you are interested in understanding the program in greater detail. Therefore, we are sending
you a copy of the RCRA Part B permit application for the MWMF (rev 3), dated November
1995. This document contains the hydrologic characterization of the plume of contamination
from the ORWBG. It describes the program underway to address groundwater contamination
at the Burial Ground Complex. The document also contains information about the buried
wastes. We hope that this document will address your comments in greater detail and provide
a fuller understanding of the groundwater program than we can provide in this letter.
Next, I have reviewed the materials received and have the following questions and comments:
1. The groundwater data furnished is principally from well locations outside the ORWBG, according
to the map showing the monitor ing well locations. Where is the data for wells with designators BG,
MGA, MGC, MGE, etc. ?
Response to Comment 1:
Groundwater characterization data that has been provided for the plume of contamination
from the ORWBG is from the RCRA Part B permit application for the MWMF. The
characterization is based on data from the RCRA approved monitoring well network and the
SCDHEC approved sampling program utilizing direct push technology (a geologic sampling
tool that is pushed into the ground to collect groundwater samples). These RCRA approved
wells are in compliance with specific requirements for well construction and sampling and
analysis procedures defined in the RCRA regulations and the SCHWMR regulations. The
purpose of the well construction and sampling and analysis requirements is to assure
consistency and accuracy in data submitted to SCDHEC and EPA which is used to
make engineering and regulatory decisions about groundwater remediation. Wells
43
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
with designators BG, MGA, MGC, and some other wells in and around the Burial Ground
Complex are old and do not meet the regulatory requirements, therefore data collected from these
wells cannot be used to support RCRA activities. Historical data exists for these wells, but most of
them have been abandoned. Data from the old wells confirms that elevated levels of tritium are
present in groundwater beneath the ORWBG.
2. The groundwater data reflecting the Maximum Levels of Constituents Exceeding the Final Primary
Drinking Water Standards is structured in a manner that is not understandable to me. For example, I
understand the Maximum Contaminant Level (MCL)for tritium to be 20pCi/m. How does this translate
to the Primary Drinking Water Standard of2. OE-05 shown on Table 9-2 of the 1992 SRS Environmental
Report?
Also, the maximum level ofTetrachloroethylene recorded at WellBGO 7Dfor 3Q94 is 193 ug/L. How
does this translate to the Primary Drinking Water Standard of .00050 mg/L for PCE shown on Table 9.2
of the 1992 SRS Environmental Report?
Response to Comment 2:
The maximum tritium concentration reported in the RCRA monitoring well network at the Burial
Ground Complex is 286,000,000 pCi/1. The MCL for tritium is 20,000 pCi/1.
Please note that because of the cumbersome nature of numbers with so many decimal places,
tritium concentrations are often reported in terms of pCi/ml or in scientific notation. The MCL for
tritium of 20,000 pCi/1 may be expressed as 20 pCi/ml or in scientific notation as 2E+01 pCi/ml (or
less commonly 2.0E °4 pCi/1, or 2x10 °4 pCi/1, or 2.0x10 01 pCi/ml). All of these notations are correct,
however, it is good practice to use a single set of units and a single notation format throughout a
document. SRS apologizes for any confusion caused by our failure to adequately describe the units
and notations cited in the supporting documentation provided at your request.
The maximum value of tetrachloroethylene (PCE) reported at wells monitoring the plume
originating at the ORWBG is 304 ug/1. The MCL for PCE is 5 ug/1. This same unit of measurement
(ug/1 is the abbreviation for micrograms per liter) is also sometimes referred to as ppb (for parts
per billion).
3. According to my calculations, the groundwater tritium concentrations mentioned on page 11 of the
ORWBG IAPP range from a minimum of 75% of the MCL toamaximum of 1,500,000% of the MCL, with
an average of 7037.25% of the MCL. Is this correct?
If so, to my knowledge, this represents a considerably higher concentration of tritium that has been
previously reported for these aquifers (i.e., the mid-199 3 tritium-contaminated groundwater plume, as
defined by the 1,000 pd/mL tritium isoactivity contour, contained zones of tritium concentrations as
high as 1,500% of the MCL in the F-Area and 800% of the MCL in the H-Area. Figure E. 4-3 (Tritium
Activities in Aquifer Zone IIB) in the Southwest Plume Area only reflects an area of concentration of
5000% of the MCL for tritium. Figure E. 4-6 (Tritium Activities in Aquifer Zone IIB) in the Southwest
Plume Area reflects an area of concentration of 500% of the MCL for tritium. Figure E.4-10 (Cross
Section M-M' Showing Tritium Activities for the Southwest Plume Area only
44
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
reflects an area of concentration of 2500% oftheMCLfor tritium. lam confused-where is the maximum
concentration of tritium mentioned on page 11 ? Where did it come from? When did it first appear in the
groundwater info?
Response to Comment 3:
The maximum tritium concentration reported in the RCRA monitoring well network at the Burial
Ground Complex is 286,000,000 pCi/1. The MCL for tritium is 20,000 pCi/1. The highest
concentration of tritium is more than 100,000 times the drinking water standard. The highest
values of tritium in the RCRA monitoring network have been measured consistently over a period
of several years at well BGO-28D. This well is located at the perimeter of the ORWBG near the
southwest corner of the fence line. Historical data from old wells within the ORWBG indicate that
levels of tritium greater than 100,000,000 pCi/1 have also been measured within the ORWBG.
The concentration of tritium in the plume of groundwater contamination associated with the
ORWBG is higher than the concentrations observed in the F and H Area Groundwater Operable
Units. The extent of the plume from the ORWBG has been well defined in the last year. The results
of this characterization were submitted to SCDHEC in revision 3 of the RCRA Part B permit
application for the MWMF in November 1995. In the RCRA documentation, the plume of
contamination from the ORWBG is referred to as the "southwest plume" because it is one of three
plumes at the Burial Ground Complex and it is located southwest of the Burial Ground Complex
(Figure E-l, page E-2). The southwest plume originates in the ORWBG and seeps into the old F
Area effluent creek which flows into Four Mile Creek in the area between the F Area seepage
basins and the H Area seepage basins. Maps of the tritium plume indicate the location of the
highest concentrations of tritium as well as the lateral geometry of the plume in each aquifer
(Figure E.4-3, page E.4-6 and Figure E.4-6, page E.4-9). Cross sections of the tritium plume are
provided in order to illustrate the vertical geometry of the plume and may not include the area of
highest contaminant concentrations (Figure E.4-10, pages 4.4-15/16).
4. The remedy addressing groundwater contamination in the F- andH-Area Groundwater Operable Units
(which I understands includes the groundwater contamination plumes in a zone which extends from the
water table surface to approximately 150 feet below the surface), as outlined in the Interim Action ROD
Remedial Alternative Selection for F-andH-Area Groundwater Operable Units provides three phases
for the recovery of contaminated groundwater via extraction wells and treatment of hazardous
constituents andradionuclides (except tritium and nitrates; however, injection of the treated water will
partially control the movement of tritium-contaminated water by lengthening the tritium flow to the seep
lines).
It is not clear from the description of the F- and H-Area Groundwater Operable Units that the
contamination plumes associated with the ORWBG IAPP are separate plumes; however, if not, I suspect
there are no more than "bright lines " on some cross-sectional map separating these underground
plumes. What is the schedule for implementing the alternative/remedy selected in April 1995? What effect
does or will this previous decision have on the Preferred Alternative described on page 17 of the
ORWBG IAPP?
I await your reply!
45
-------
Interim Record of Decision for the WSRC-RP-96-102
Old Radioactive Waste Burial Ground (643-E) Revision 0
Savannah River Site March 1996
Response to Comment 4:
There is some mingling of tritium plumes from the H Area Seepage Basins and the ORWBG. This
mingling occurs outside the plume area to be addressed in the first phase of groundwater
remediation at the H Area Seepage Basins. Phase 1 of the groundwater remediation project at the
F and H Area Groundwater Operable Units is presently under construction. Start up of treatment
is planned for early 1997. The decision to pump and treat groundwater at the F and H Area
Seepage Basins has no direct influence on the interim action proposal to put a soil cover on the old
burial ground, but any corrective action proposed for the plume from the ORWBG will
complement the ongoing program at F and H Area Seepage Basins and will be enhanced by the
placement of a soil cover on the ORWBG.
It is the goal of SRS to address all of the groundwater contamination in the entire area in a
comprehensive manner. All the planned and proposed actions are part of an integrated strategy
to address groundwater at these adjacent facilities in a manner that is technically sound, cost
effective, and complies with all applicable environmental regulations. The first step in groundwater
remediation is to control the source of contamination. Placement of a soil cover on the ORWBG
will achieve that first step by reducing the amount of contamination that reaches the groundwater,
and it will achieve it in a manner that will allow continued work toward the development of the
best final solution for dealing with the ORWBG.
46
------- |