PB94-964058
EPA/ROD/R04-94/187
September 1994
EPA Superfund
Record of Decision;
Savannah River Site,
(USDOE), SC,
9/23/1994
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WSRC-RP-94-106
Revision 1
September 9. 1994
UNITED STATES DEPARTMENT OF ENERGY
SAVANNAH RIVER SITE
FINAL RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
for
Tank 105-C Hazardous Waste Management Facility (U)
Prepared by
Environmental Restoration Engineering
WESTINGHOUSE SAVANNAH RIVER COMPANY
SAVANNAH RIVER SITE
AIKEN, SC 29808
PREPARED FOR THE US DEPARTMENT OF ENEFGY UNDER CONTRACT DE-AC09-89SR18035
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Final ROD
Tank 1OS-C HWMF
WSRC-RP-94-106
Revision 1
September 9. 1994
DECLARATION FOR THE FINAL RECORD OF DECISION
Site Name and Location
Tank 105-C Hazardous Waste Management Facility (HWMF)
Savannah. River Site
Aiken County, South Carolina
Statement 0' Basis and Purpose
This document presents the selected final action for the Tank 105-C HWMF Unit
and the immediately adjacent soils at the Savannah River Site (SRS), which
was developed in accordance with the Comprehensive Environmental
Response, Compensation and Liability Act of 1980 (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 for this unit.
Description 0' the Selected Remedy
Previous action taken was under a Resource Conservation and Recovery Act
(RCRA) Closure Plan, per Settlement Agreement 90-64-SW (September 5,
1990) USDOE, Savannah River Site, approved by the State of South Carolina
and is protective of human health and the environment. Therefore, no further
action is necessary under CERCLA.
The selected final action remedy involved the neutralization of waste from a pH
of 13.2 to a pH of less than 12.5, removal of as much waste as reasonably
possible, and shipment of the waste to an onsite storage/disposal facility. All
remaining waste and the tank void were stabilized in place with concrete. This
remedy prevents physical exposure to contaminants (radio nuclides) and
2
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Rnal ROD
Tank 105-C HWMF
WSRC-RP-94-106
Revision 1
September 9. 1994
mitigates potential migration of contaminants to the groundwater by stabilizing
the liquid medium and minimizing the pathway for transport.
The major components of the RCRA action already conducted include:
1) Waste (including organic, aqueous, and sludge phases) neutralization with
the addition of a mixture of oxalic acid and water;
2) Removal of 37 gallons of oily substance using an oil skimmer,
3) Removal of 3,753 gallons of aqueous and sludge waste, including water
added during neutralization and tank rinse activities; and shipment to an on-site
storage/disposal facility;
4) Tank assessment, which included a tank tightness test using the Homer EZY
Check II Method;
5) Removal of 8,000 gallons of secondary wastewater (generated duri ng the
tank tightness test) and shipment to an on-site storage! disposal facility;
6) Soil assessment, which consisted of 2 background samples and 18 samples
from soil borings around the ancillary piping (excluding inaccessible ancillary
piping beyond an adjacent walVfoundation) and Tank 105-C, and included
visual observation, pH testing and radiological screening of soils;
7) Removal of 400 cubic feet of radiologically contaminated soil adjacent to the
ancillary piping;
8) Removal of ancillary piping (90 cubic feet) followed by capping of ancillary
piping stubs into the reactor area, pH testing of pipe sections. and
removaVplacement in 90 cubic foot containers for disposal or capped in place;
3
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Fmal ROD
Tank 105-C HWMF
WSRC-RP-94-106
Revision 1
September 9, 1994
9) In place fil6ng 01 tank (and residual waste) induding two risers with concrete;
10) Capping risers above the tank with metal caps and epoxy;
11) Surface restoration (backfilling 01 piping, tank excavations, and paving
backfilled areas with asphalt); and
12) Restricting access to the Tank 105-C HWMF to authorized personnel with
appropriate training on applicable requirements.
Declaration Statement
Previous action taken at the Tank 105-C HWMF was under a RCRA Closure
Plan approved by the State of South Carolina and was protective of human'
health and the environment. Therefore, no further remedial action is necessary
under CERCLA. To ensure continued protection 01 human health and the
environment, this action will be reviewed every 5 years, consistent with the
requirements 01 the NCP.
f/;';'~
Date
1Z--9'/4~
Thomas F. Heenan
Assistant Manager for Environmental
Restoration & Sofld Waste
U.S. Department of Energy
9-ZS-Q4
Date .
~/'r)~
John H. Hankinson, Jr. -f'
Regional Administrator
U. S. Environmental Protection Agency
Region IV
4
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WSRC-RP-94-106
Revision 1
SePtember 9,1994
SUMMARY OF FINAL ACTION
REMEDIAL ALTERNATIVE SELECTION
for
Tank 105-C Hazardous Waste Management Facility (U)
Prepared by
Environmental Restoration Engineering
WESTINGHOUSE SAVANNAH RIVER COMPANY
SAVANNAH RIVER SITE
AIKEN, SC 29808
PREPARED FOR THE US DEPARTMENT OF ENERGY UNDER CONlRACT DE-~SR18005
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Final ROD
Tank 105-C HWMF
WSRC-RP-94-106
Revision 1
September 9, 1994
DECISION SUMMARY TABLE OF CONTENTS
Section Page
I. Site and Operable Unit Names, Locations, and Descriptions 1
II. Operable Unit History and Compliance History 1
III. Highlights 01 Community Participation 6
IV. Scope and Role of Operable Unit within the Site Strategy 6
V. Summary of Operable Unit Characteristics 7
VI. Summary of Operable Unit Risks 8
VII. Explanation of Significant Changes 9
ApDendices
A.
B.
References for Development of ROD Format
Responsiveness Summary
10
1 1
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Final ROO
Tank 105-C HWMF
WSRc.RP-94-106
Revision 1
September 14. 1994
Site and Operable Unit Names, Locations, and Descriptions
I.
The Savannah River Site (SRS) occupies approximately 310 square miles
adjacent to the Savannah River, principally in Aiken and Barnwell Counties 01
South Carolina. (Figure 1) SRS is a secured U.S. government facility with no
permanent residents. The Site is located approximately 2S miles southeast of
Augusta, Georgia, and 20 miles south of Aiken, South Carolina. According to
1990 census data, the average population densities (in people per square mile)
for the counties surrounding SRS range from 21 to S24 with the largest
concentration in the Augusta, Georgia, metropolitan area. The population
within a SO-mile radius of SRS is 634,784.
SRS is owned by the United States Department of Energy (DOE).
Westinghouse Savannah River Company (WSRC) is the managing and
operating contractor for DOE. SRS produces tritium, plutonium, and other
special nuclear materials for national defense. The site also provides nuclear
materials lor the space program, and conducts medical, industrial, and research
efforts. The Tank 10S-C HWMF is a source specific operable unit within the C-
Area Fundamental Study Area. The Tank 10S-C HWMF consists of one 8,400
gallon capacity underground storage tank and ancillary piping located in C-
Area, east of C Reactor 10S-C and approximately 6 miles from the nearest site
boundary (Figure 2). This tank and ancillary piping are the only aspects being
addressed in this Record of Decision (ROD).
II.
Operable Unit History and Compliance History
Operable Unit History
The Tank 105-C HWMF was installed in 1961 as part of an off-line heat
exchanger repair program and was used as a temporary holding tank for liquid
1
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FIllaI ROD
Tank 105-C HWMF
WSRC-RP-94-106
Revision 1
September 9,1994
solution. Sumps from the heat exchanger cleaning area drained into Tank 105-
C. Oil in the tank was probably attributable to oil leaks into these sumps. The
reacted or spent oxalic acid solution that resulted from the rinsing process was
pumped into an above ground neutralization tank in the stack area 01 the
reactor building. Potassium hydroxide (KOH) was then added and mixed to
raise the solution pH to 8.0 or above. After neutralization, the waste was
transferred to the underground storage Tank 105-C HWMF for temporary
storage. It was common for the neutralization process to require additional pH
adjustment inside Tank 105-C, accomplished by circulating the waste in the
tank with a pump and adding more KOH to fine tune the pH. A permanent pump
was set up to pump the waste into a waste trailer for transportation to a
storage/disposal facility. The pump and circulation lines were disassembled in
1983.
The Tank 105-C HWMF was closed by neutralization of waste to a pH of less
than 12.5, removal of as much waste as reasonably possible, and shipment 01
removed waste to an onsite storage/disposal facility. Any remaining waste and
the tank void were stabilized with concrete. (Rgure 3)
Compliance History
Previous remediation actions at the Tank 105-C HWMF were conducted
pursuant to the requirements of the Resource Conservation and Recovery Act
(RCRA) per Settlement Agreement 90-64-SW (September 5, 1994) US DOE,
Savannah River Site, which is an agreement between the State of South
Carolina Department of Health and Environmental Control (SCDHEC) and the
Department of Energy to prepare and submit a closure plan in accordance with
R.61-79.265 Subpart G. In October 1990, a RCRA Closure Plan was submitted
4
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FanaJ ROD
Tank 105-C HWMF
WSRC-RP-94-106
Revision 1
September 9,1994
to the SCDHEC. SRS received approval of the closure plan on January 16,
1991 , with no revision required. Revisions and subsequent approvals were
made to the Closure Plan during closure activities. Closure of the Tank 105-C
HWMF began in May 1991 and was completed in September 1991. The Tank
105-C HWMF was certified closed in November 1991. In December 1991,
closure certification was accepted by SCDHEC as being in compliance with
RCRA requirements.
Closure activities specifically included the neutralization of waste to a pH 01 less
than 12.5, removal of as much waste as reasonably possible, and shipment of
removed waste to an onsite storage/disposal facility. Any remaining waste and
the tank void were stabilized with concrete. RCRA activities at the Tank 105-C
HWMF became subject to CERCLA when the entire SRS facility was placed on
the National Priorities Ust (NPL) in December 1989. The Tank 105-C HWMF is
a source-specific operable unit within the G-Area Fundamental Study Area.
III.
Highlights of Community Participation
The public comment period for the Proposed Plan ran from August 1, 1994 to
August 30, 1994. Comments were received on the Tank 105-C HWMF and are
addressed in Appendix B of the Record of Decision in the Responsiveness
Summary.
IV.
Scope and Role of Operable Unit within the Site Strategy
The selected final action remedy involved the neutralization of waste from a pH
of 13.2 to a pH of less than 12.5, removal of as much waste as reasonably
possible, and shipment of the waste to an onsite storage/disposal facility. All
remaining waste and the tank void were stabilized in place with concrete. This
6
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Final ROD
Tank 10S-C HWMF
WSRC-R P-94-1 06
Revision 1
September 9. 1994
remedy prevents physical exposure to contaminants (radionuclides) and
mitigates potential migration of contaminants to the groundwater by stabilizing
the liquid medium and minimizing the pathway for transport.
The No Further Action Decision action will be reviewed every five (5) years to
assure continued protection by the RCRA corrective action of human health and
the environment. While previous remediation actions did not involve action on
the groundwater, future investigations of the C-Area will be made. A site wide
risk assessment will be performed at the conclusion of the Savannah River
cleanup to ensure that the site as a whole is protective of human health and the
environment. Based on the results of this risk assessment, additional cleanup
at the SRS may be required.
Due to the previous Tank 105-C HWMF RCRA corrective action, No Further
Action under CERCLA is necessary for this source control operable unit. Th.e
RCRA corrective action provides the necessary protectiveness to human health
and the environment to satisfy all CERCLA requirements.
v.
Summary 01 Operable Unit Characteristics
Previous action taken was under a RCRA Closure Plan approved by the State
of South Carolina and was protective of human health and the environment.
Therefore, no further action is necessary under CERCLA.
Prior to the RCRA closure, chemicals of concern at the Tank 105-C HWMF
included tritium and other radionuclides (gross alpha and gross beta/gamma) in
a characteristic hazardous waste with a pH of 13.2. Risks associated with these
chemicals were addressed by the RCRA closure of the tank which was
consistent with the RCRA Closure Plan. Thus, the constituents no longer pose a
7
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Rnal ROD
Tank 10S-c HWMF
WSRc-RP-94-106
Revision 1
September 9. 1994
threat to human health and the environment. (Tank 105-C HWMF post closure
chemicals of concern are residual minimal quantities of radio nuclides solidified
with concrete with a pH of less than 12.5.) Since the waste was neutralized, the
solidified waste remaining in the tank is radioactive waste which has been
immobilized.
VI.
Summary 01 Operable Unit Risks
Due to the previous Tank 105-C HWMF RCRA action, No Further Action is
necessary under CE RCLA for this source control operable unit. The RCRA
corrective action is protective of human health and the environment and
satisfies CERCLA requirements.
Wastes remaining in the Tank 105-C HWMF were stabilized along with the tank
void following treatment, removal 01 as much waste as reasonably possible. and
shipment to an onsite storage/disposal facility. Additional contaminated soils
adjacent to the ancillary piping were removed and shipped to an onsite
storage/disposal facility.
Therefore, exposure through surface soil and
sediment pathways is minimized.
Preventive alternatives were developed for the Tank 105-C HWMF based on
effective technologies available at the time the RCRA Closure Plan was
prepared. The RCRA Closure Plan was initially submitted to SCDHEC in
October 1990 and was approved in January 1991. Revisions and subsequent
approvals were made to the Closure Plan during closure activities.
Options regarding the Tank 105-C HWMF evaluated at that time included:
Alternative 1
No Action
8
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Fanal ROD
Tank 105-C HWMF
WSRC-RP-94-106
Revision 1
September 9. 1994
Alternative 2
No Waste Removal and Tank Closure
Alternative 3
Waste Removal and Tank Closure
Alternative 3 was selected within the RCRA closure process in 1990 as the most
technically effective of the three alternatives for protection of human health and
the environment. Closure of the Tank 105-C HWMF began in May 1991 and
was completed in September 1991. The closure was certified in November
1991 and accepted by SCDHEC as being in compliance with RCRA and state
requirements in December 1991. The closure is considered a final action under
CERCLA.
VII.
Explanation of Significant Changes
There were no significant changes.
9
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,--
Final ROD
Tank 1OS-C HWMF
WSRC-RP-94-106
Revision 1
September 9. 1994
Appendix A
References for Development of ROD Format
Weeks, Victor, 1993. "Regarding Records of Decision, F-Area and H-Area,
Savannah River Site, Aiken, South Carolina", Letter to Goidel! (DOE),
Savannah River Site, Aiken, SC, April 14, 1993.
EPA, 1991. "Guide to Developing Superfund No Action, Interim Action, and
Contingency Remedy RODs," OSWER Publication 9355.3-02FS-3. U.S.'
Environmental Protection Agency, Washington, D.C., April 1991.
WSRC, 1992. "RCRA Facility Investigation/Remedial Investigation Program
Plan," WSRC-RP-89-994, Rev. 1, Chapter 15, Westinghouse Savannah
River Company, Aiken, South Carolina, May 1992.
10
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Fanal ROD
Tank 105-C HWMF
WSRC-RP-94-106
Revision 1
September 14, 1994
Appendix B
Responsiveness Summary
DOE has received comments regarding the Tank 105-C HWMF and they have
been addressed in this Responsiveness Summary. These comments are
available for review in the Administrative Record.
A reviewer provided a comment on the Tank 105-C HWMF item in the SR S
Environmental Bulletin volume 5 number 15 dated July 25, 1994. This
comment referred to ambiguous wording which implied "...that the neutralized
liquid and sludge must have been left in the tank... II and suggested revision of
this paragraph. The issue raised in the SRS Environmental Bulletin has been
addressed and is clearly stated in the Proposed Plan and the Record of
Decision.
A reviewer provided comments on the Proposed Plan for the Tank 105-C
HWMF (U), WSRC-RP-94-56, June 24, 1994. The introductory comment stated
that "The RCRA closure of the tank appears to have been an adequate short-
term measure but is premature to state, as this plan does that "no further
remedial action is necessary under CERCLA." This specific ROD addresses
only the tank and ancillary piping and is a final action. Specific comments are
italicized followed by comment response.
c:
R:
"Until the contaminated soils around the tank and its piping have been
adequately characterized we do not agree that no further remedial actions
under CERCLA are necessary. "
This comment is outside the scope of this ROD. This specific ROD
addresses only the tank and ancillary piping and is a final action. DOE
will adequately address the contaminated soils surrounding the tank and
ancillary piping as the C-Area operable unit is evaluated.
11
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Final ROO
Tank 105-C HWMF
WSRC-RP-94-106
Revision 1
September 14, 1994
c:
.SRS should describe the relationship between the decontamination and
decommissioning goals and plans for the C-Area and the CERCLA
requirements for the operable units in the C-area Fundamental Study
Area. EPA and SCDHEC should describe their understanding and
expectations of this relationship as wel,. It is important that the goals and
standards of the RCRA/CERCLA and D&D efforts be compatible, resulting
in a vel}' similar level of environmental and public health protection. .
This comment is outside the scope of this ROD. Buildings and areas
contained within the C-Area Fundamental Study Area (FSA) are in the
Site Evaluation program and will eventually be addressed per the
schedules in Appendices D and E of the Federal Facility Agreement
(FFA). Decontamination and decommissioning actions in the C-Area FSA
will be addressed based on future evaluations.
R:
c:
.There should be a CERCLA risk assessment for the C-Area FSA that
encompasses the 105.0 HWMF, the other C-Area operable units, and the
reactor buildings and other structures requiring decontamination and
decommissioning. By consolidating the risk assessment, common
assumptions about land use, demographics, and exposure pathways
could be assessed to evaluate the consistency and adequacy of af(
remedial actions within the C-Area FSA.
CERCLA risk assessment will be performed for the contaminated. soils
and groundwater operable units associated with the C-Area FSA after
they are characterized per the schedules contained in Appendices D and
E of the FFA. The action for the tank and ancillary piping was performed
under RCRA and no additional action is required on this unit.
R:
c:
.Although we concur that the closed tank does not present a near-term
risk to the public health or the environment, SRS should acknowledge that
it may be necessary to exhume the tank in order to meet land use
objectives. .
Based on future investigations at the C-Area FSA, DOE acknowledges
that it may be necessary to exhume the tank.
R:
12
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WSRC-RP-93-1511
Revision 1
September 12, 1994
UNITED STATES DEPARTMENT OF ENERGY
SAVANNAH RIVER SITE
FINAL RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
FOR
Mixed Waste Management Facility (U)
Prepared by
WESTINGHOUSE SAVANNAH RIVER COMPANY
SAVANNAH RIVER SITE
AIKEN, SC 29802
------------------------------------------------------------------------
PREPARED FOR THE US DEPARTMENT OF ENERGY UNDER
CONTRACT DE-AC09-89SR18035
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-, -. - -
FINAL ROD
MWMF
WSRC-RP-93-1511
Revision 1
September 12, 1994
DECLARATION FOR THE FINAL RECORD OF DECISION
Site Name and Location
Mixed Waste Management Facility (MWMF)
Savannah River Site
Aiken County, South Carolina
Appendix H of the Federal Facility Agreement (FF A) lists this unit as the Mixed
Waste Hazardous Waste Management Facility (Building Number 643-28G).
Statement of Basis and Purpose
This document presents the selected final preventive action for the MWMF Unit
at the Savannah River Site (SRS), which was developed in accordance with the
Comprehensive Environmental Response, Compensation and Liability Act 01
1980 (CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA), and to the extent practicable, the National
Oil and Hazardous Substances Pollution Contingency Plan (NCP). This
decision is based on the Administrative Record for this unit.
Description of the Selected Remedy
The selected final action remedy announced in this Record of Decision is no
further action. As described below, a remedy under RCRA was completed for
this unit in December 1990.
This RCRA corrective action involved the
precompaction and placement of all contaminated materials under a low
permeability cap.
This RCRA remedy prevents physical exposu re to
contaminants and mitigates further migration 01 contami nants to the
I
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FIN AL ROD
MWMF
WSRC-RP-93-1511
Revision 1
September 12, 1994
groundwater by minimizing a liquid medium pathway (rainwater percolation) for
transport.
No further action is necessary for the unit. However, as a condition of the RCRA
Hazardous Waste Permit, post closure groundwater monitoring is required to
verify that no unacceptable exposures to potential hazards posed by conditions
at the operable unit occur in the future.
This unit was closed by the
requirements of a closure plan approved in December 1987 by the state of
South Carolina under RCRA authority. The RCRA closure of MWMF began in
1988 and was completed in December 1990. MWMF was certified closed in
1991. In April 1991, the closure certification was accepted by the state of South
Carolina as being in compliance with RCRA requirements.
The major components of the RCRA preventive action included:
1) Precompaction.
2) Initial backfill after compaction to level 5 feet below final cover elevations.
3) Placement of a final cover over the trenches. The cover consists of a three
foot minimum layer of compacted kaolin clay with a permeability of 1 x1 0-7
em/see or less. two feet of final cover and vegetative cover, cap drainage and
stormwater conveyance system (See below).
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II
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FINAL ROD
MWMF
WSRC-RP-93-1511
Revision 1
September 12, 1994
4) The MWMF is being routinely inspected for a minimum of 30 years to verify
the integrity of the cover system, fences, signs, etc. Any necessary repairs to the
cap will be made as part of the maintenance program.
5) Access to the MWMF is restricted to authorized personnel with appropriate
training on applicable requirements. The survey plat and records associated
with deed restricted use of the MWMF have been filed with Aiken County, SC.
Declaration Statement
Previous action taken at the MWMF was under a RCRA Closure Plan, per
NRDC et a!. v. Herrington, Civ. Action No.1 :85-2583-6 (D.S.C. May 26, 1988),
approved by the state of South Carolina and was protective of human health
and the environment. Therefore, no further remedial action is necessary under
CERCLA.
To ensure continued protection of human health and the
environment, this remedial action will be reviewed every 5 years, consistent
with the requirements of the NCP.
,/;&;/?'('
Date
'iZ--
~~,
r/~ .----.
Thomas F. Heenan
Assistant Manager for Environmental
Restoration and Solid Waste
U.S. Department of Energy
CJ-2.$ -fil/
Date
~j'Yr7~ JrI\
John H. Hankinson, Jr. I
Regional Administrator,
U.S. Environmental Protection Agency
Region IV
III
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WSRC-RP.93-1511
Revision 1
September 12, 1994
SUMMARY OF FINAL ACTION
REMEDIAL ALTERNATIVE SELECTION
FOR
Mixed Waste Management Facility (U)
Prepared by
WESTINGHOUSE SAVANNAH RIVER COMPANY
SAVANNAH RIVER SITE
AIKEN, SC 29802
------------------------------------------------------------------------
PREPARED FOR THE US DEPARTMENT OF ENERGY UNDER
CONTRACT DE-AC09-89SR18035
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FINAL ROD
MWMF
WSRC.RP-93-1511
Revision 1
September 12 1994
DECISION SUMMARY
TABLE OF CONTENTS
Section Pace
I. Site and Operable Unit Names, Locations, and 1
Descriptions
II. Operable Unit History and Compliance History 4
III. Highlights of Community Participation 6
IV. Scope and Role of Operable Unit within the Site 6
Strategy
V. Summary of Operable Unit Characteristics 7
VI. Summary of Operable Unit Risks 7
VII. Explanation of Significant Changes 8
ApDendices
A
B.
References for Development of ROD Format
Responsiveness Summary
9
10
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FINAL ROD
MWMF
WSRC-RP-93-1511
Revision 1
September 12, 1994
I.
Site and Operable Unit Names, Locations, and Descriptions
The Savannah River Site (SRS) occupies approximately 310 square miles
adjacent to the Savannah River, principally in Aiken and Barnwell Counties of .
South Carolina (Figure 1). SRS is a secured facility with no permanent
residents. The site is approximately 25 miles southeast of Augusta, Georgia,
and 20 miles south of Aiken, South Carolina. The average population density
in the counties surrounding SRS ranges from 21-524 people per square mile
with the largest concentration in the Augusta, Georgia, metropolitan area.
Based on 1990 census data, the population within a 50-mile radius of SRS is
approximately 634,784.
SRS is owned by the United States Department of Energy (DOE).
Westinghouse Savannah River Company (WSRC) is the managing and
operating contractor for DOE. SRS produces tritium, plutonium, and other
special nuclear materials for national defense. The site also provides nuclear
materials for the space program, and conducts medical, industrial, and research
efforts. The Mixed Waste Management Facility (MWMF) is a source specific
operable unit within the Burial Ground Complex Fundamental Study Area. The
MWMF consists of 118 slit trenches, 1 Engineered Low Level Trench (ELL T -1),
and a naval core barrel mound and is located in the center of SRS, between F
and H Areas (Figure 2).
1
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FINAL ROD
MWMF
WSRC-RP-93-1511
Revision 1
September 12, 1994
G91H011.01
Figure 1 Location of the Savannah River Site (SRS)
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FINAL ROD
MWMF
WSRC-RP-93-1511
Revision 1
September 12, 1994
Mixed Waste Management Facility
MWMF
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Figure 2
MWMF
3
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FINAL ROD
MWMF
WSRC-Rp-93-1511
Revision 1
September 12, 1994
II.
Operable Unit History and Compliance History
Operable Unit History
The MWMF operated from 1969 until March 11, 1986. During that time, this
facility, which comprises approximately 58 acres, received low-level radioactive
waste materials produced at the SRS. Some of these materials are classified
as mixed waste containing both hazardous and radioactive components under
the Resource Conversation and Recovery Act (RCRA). These trenches were
closed by precompacting and placing a protective multi-layer cover system
(Figure 3) over them to reduce rainwater contact with trench bottoms.
Compliance History
RCRA preventive actions at the MWMF were conducted pursuant to the
requirements of the Resource Conservation and Recovery Act (RCRA) per
NRDC et al. v. Herrington, Civ. Action No. 1:85-2583-6 (D. S.C. May 26,1988)
which is an order from the court in settlement of the lawsuit for closure of the
facility under RCRA. In 1985 a RCRA Closure Plan was submitted to SCDHEC .
The closure plan underwent several revisions prior to approval by SCDHEC in
1987. Closure of the MWMF was begun in 1988 and completed in December
1990. The MWMF was certified closed in 1991. In April 1991, the closure
certification was accepted by SCDHEC as being in compliance with RCRA
requirements. A RCRA Part B Permit Application for Post-Closure Care was
submitted in November 1992.
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Mixed Waste Management Facility
Closure Cap Cross Section
Vegetative Cover
Top Soil (2 ft)
Compacted Low Permeability
Clay Layer (3 ft)
Subgrade
(Initial Fill) (2-7 ft)
Backfill (To Grade)
Trench
Figure 3 MWMF Cap Cross Section
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Closure activities specifically included precompaction; construction of a low
permeability cap over the trenches; and restoration of the area.
RCRA preventive activities at the MWMF became subject to CERCLA when the
entire SRS facility was placed on the National Priorities Ust (NPL) in December
1989. The MWMF is a source-specific operable unit within the Burial Ground
Complex Fundamental Study Area.
III.
Highlights of Community Participation
The public comment period ran from 01 August 94 - 30 August 94. All
comments submitted on the Proposed Plan have been incorporated into this
ROD, where appropriate and are addressed in the Responsiveness Summary
(Appendix B).
IV.
Scope and Role 01 Operable Unit within the Site Strategy
The selected RCRA remedy involved the placement of all contaminated
materials under a low permeability cap. The remedy prevents physical
exposure to contaminants and mitigates further migration of contaminants from
the MWMF to groundwater by minimizing a liquid medium pathway (rainwater
percolation) for transport.
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v.
Summary of Operable Unit Characteristics
Waste from SRS disposed in the form of job control waste such as rags, gloves
and coveralls, soli, construction debris, failed equipment, spent air filters, spent
lithium-aluminum targets, irradiated scrap metal, naval reactor hardware, lead
shielding, waste oil, scintillation fluids, cadmium and silver coated beryl
saddles, were sent to the MWMF. The constituents of concern at the MWMF are
barium, chloroform, cadmium, 1,1-dichloroethane, vinyl chloride, trans-1,2
dichloroethylene, phenol, aluminum, iron, manganese, carbon-14, lead, tritium,
nickel, tetrachloroethylene, trichloroethylene (TCE), zinc, uranium-234/235,
uranium-238. The primary constituents of concern are tritium, lead, TCE, and
uranium.
VI.
Summary of Operable Unit Risks
Due to the previous MWMF RCRA preventive action, No Further Action under
CERCLA is necessary for this source control operable unit. The RCRA
preventive action is protective to human health and the environment and
satisfies CERCLA requirements.
The trenches were first compacted and then were covered with a low
permeability soli cap. Therefore, exposure. through surface soil and sediment
pathways is minimized because of this RCRA cap.
Preventive alternatives were developed for the MWMF based on effective
technologies available at the time the RCRA Closure Plan was prepared. The
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RCRA Closure Plan was initially submitted to SCDHEC in November 1985 and
was approved, following several revisions, in December 1987.
Options regarding the MWMF evaluated at that time included:
Alternative 1
No Action
Alternative 2
No Waste Removal, Waste Consolidation, and Closure
Alternative 3
Waste Removal and Closure
Alternative 2 was selected within the RCRA closure process in 1985 as the most
technically effective of the three alternatives for protection of human health and
the environment. Closure of the MWMF was begun in 1988 and completed in
1990. The closure was certified in April 1991 and accepted by SCDHEC as
being in compliance with RCRA and state requirements. The closure is
considered a final action under CERCLA.
VII.
Explanation of Significant Changes
There were no significant changes made to the remedy decision since the
publishing of the proposed plan on 01 August 1994.
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Appendix A
References for Development of ROD Format
EPA, 1991. "Guide to Developing Superfund No Action, Interim Action, and
Contingency Remedy RODs," OSWER Publication 9355.3-02FS-3, U.S.
Environmental Protection Agency, Washington, D.C., April 1991.
WSRC, 1992. "Draft RCRA Facility InvestigationlRemediai Investigation
Program Plan," WSRC-RP-89-994, Rev. 1, Chapter 15, Westinghouse
Savannah River Company, Aiken, South Carolina, May 1992.
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Appendix B
Responsiveness Summary
DOE has received comments regarding the MWMF and they have been
addressed in this Responsiveness Summary. These comments are available
for review in the Administrative Record.
A member of the public provided comments on the MWMF item in the SRS
Environmental Bulletin volume 5 number 15 dated July 25, 1994. This
comment referred to adding a figure representing the amounts of hazardous
waste in the facility and the approximate volume of compacted waste. The
issue raised in the SRS Environmental Bulletin concerning the hazardous
waste volumes has been addressed and is clearly presented in the Proposed
Plan. The issue concerning the volume of compacted waste is clarified here.
Compaction at this waste site was done in order to form a stable foundation for
the kaolin clay cap; therefore, no measurement was conducted to determine the
exact waste consolidation.
An interested party provided comments on the MWMF Proposed Plan in a letter
to C. V. Anderson dated September 8, 1994. The specific comments and their
responses are as follows:
C:
SRS has not demonstrated the assertion that because of the RCRA
closure at the MWMF "the unit poses no current or potential threat to human
health or the environment" and, thus, "no further action is necessary under
CERCLA." In ERF's July 9, 1993 letter to David Wilson at SCDHEC and Len
Sjostrom at SRS we provided extensive comment and criticism on the RCRA
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post-closure risk assessment for the MWMF. We have never received a direct
response from SRS. If there is a risk assessment to support a "no further
remedial action" position under CERCLA then we request the opportunity to
review it.
R:
RCRA closure of a land disposal unit in which waste is left in place is
protective of human health and the environment under RCRA and therefore, a
risk assessment is not required. The actions taken at the MWMF under the
RCRAICERCLA program were completed within the requirements set forth by
SCDHEC and the EPA.
c:
Additionally, the decision to leave waste buried at MWMF and the other
Burial Ground Complex facilities is a de facto decision about long-term land
use. Given the long-lived nature of many of the wastes, the implied restriction
goes far beyond the 30 and 100 year institutional control projections which
shaped the earlier risk assessments. If, in fact, unrestricted use of the site after
100 years is not going to be safe, then SRS and its regulators should
acknowledge this and commit to some additional decision making.
R:
These actions are protective of human health and the environment and
will be reviewed every 5 years as required by CERCLA and the RCRA post
closure care permit renewal process.
c:
Until there is a meaningful land-use planning process at SRS involving
stakeholders, the attainment of primary drinking water standards at the
perimeter of the BGG should be a minimum requirement. It's not clear that
SRS can meet these standards without additional source control at MWMF and
the other BGC facilities. If additional source control is necessary to meet
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primary drinking water standards at the BGC perimeter, SRS and its regulators
should work together to examine how to locate specific sources of contaminants
within the BGC and what technology and/or research and development options
are necessary to remedy the situations.
R:
The MWMF groundwater is being addressed under RCRA which is a
groundwater based program. Under RCRA, monitoring of the subsurface
contamination is being conducted.
Investigation of the groundwater
contamination is currently ongoing and will be addressed under separate
regulatory documentation. This MWMF Proposed Plan is for the source control
operable unit only. All other source control units, including the groundwater
operable unit, will be addressed under separate Proposed Plans and Records
of Decision.
DOE land use policy is being developed currently but until
finalized, 5 and 30 year reviews will be maintained.
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