PB98-964028
EPA 541-R98-187
March 1999
EPA Superfund
Record of Decision:
Savannah River Site (USDOE)
OUs 41,42,52 & 54
Aiken, SC
9/14/1998
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Ut //,
United States Department of Energy
Savannah River Site
Record of Decision
Remedial Alternative Selection for the
C-, F-, K-, and P-Area Coal Pile Runoff Basins (189-C,
289-F, 189-K, and 189-P) (U)
WSRC-RP-97-850
Revision 1
July 1998
SEP 21 1996
DIVISION OF SITE
ASSESSMENT &
4*
Westinghouse Savannah River Company / ^> 5-s £« \
Savannah River Site * *""
Alken, SC 29808
Prepared for the U. S. Department of Energy under Contract No. DE-AC09-96SR1B500
IAVAMMAM «IVt« fITI
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RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION (U)
C-, F-, K-, and P-Area Coal Pile Runoff Basins
(189-C, 289-F, 189-K, and 189-P)
WSRC-RP-97-850
Revision 1
July 1998
Savannah River Site
Aiken, South Carolina
Prepared by:
Westinghouse Savannah River Company
for the
U. S. Department of Energy Under Contract DE-AC09-96SR18500
Savannah River Operations Office
Aiken. South Carolina
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DECLARATION FOR THE RECORD OF DECISION
Unit Name and Location
C-. F-, K-, and P-Area Coal Pile Runoff Basins (189-C, 289-F, 189-K. and 189-P)
Savannah River Site
Aiken, South Carolina
The C-, F-, K-, and P-Area Coal Pile Runoff Basins (189-C, 289-F, 189-K, and 189-P) (C-. F-. K-, and P-
CPRBs) waste units are listed as Resource Conservation and Recovery Act (RCRA) 3004(u) Solid Waste
Management Units/Comprehensive Environmental Response, Compensation and Liability Act (CERCLA)
units in Appendix C of the Federal Facility Agreement (FFA) for the Savannah River Site (SRS). The C-,
F-, K-, and P-CPRBs comprise a single operable unit which was remediated under an early removal action
during the summer of 1997.
Statement of Basis and Purpose
This decision document presents the selected remedial alternative for the C-, F-, K-, and P-CPRBs located
at the SRS in Aiken, South Carolina. The selected alternative 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 operable unit.
Assessment of the Site
Slightly elevated levels of naturally occurring metals and radionuclides in the coal-laden sediments and
shallow soils were confined to the 0-1 foot interval below the basin floor. These source materials were
identified as low level threat wastes. Under the Removal Site Evaluation ReponlWastewater Closure Plan for
the C-, F-, K-. and P-Area Coal Pile Runoff Basins (189-C, 289-F, 189-K. and 189-P) (U) (WSRC I997b),
the coal-laden sediments and shallow soils were removed from each of the four basins during the summer of
1997. At least four feet of clean backfill was placed in each basin to restore the area to the surrounding grade.
This removal action completely freed the four CPRBs of the source material for the constituents of concern
and the sulfide minerals, which were reducing the pH of the infiltrate. Because the source material has been
removed from the CPRBs, releases of hazardous substances will not occur from this operable unit and there is
no imminent or substantial endangermcnt to public health, welfare, or the environment.
Description of the Selected Remedy
The preferred alternative for the C-, F-, K-, and P-CPRBs operable unit is No Further Action with a five-year
period of confirmatory groundwater monitoring at the K-CPRB.
Gross alpha and the sum of radium-226 and radium-228 have occasionally exceeded maximum contaminant
levels (MCLs) in the water table aquifer at the K-CPRB. Based on the groundwater monitoring history, no
significant groundwater contamination has originated from the C-, F-, and P-CPRBs. The probable condition
for the groundwater at all of CPRBs is no significant groundwater contamination resulting from the operation
of the CPRBs. As a result, no remedial action is deemed appropriate for the water table aquifer at the CPRBs.
Confirmatory groundwater monitoring, as discussed in Section IX of the ROD, will be conducted for five
years at the K-CPRB. Confirmatory monitoring should demonstrate that No Further Action is the appropriate
remedy. In the event that the probable condition is no longer appropriate. DOE, SCDHEC. and EPA (the
three panics to the Federal Facility Agreement) will evaluate the need for remedial action.
The South Carolina Department of Health and Environmental Control has modified the SRS RCRA permit
(SCI 890 008 989) to incorporate the selected remedy.
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Statutory Determinations
The Removal Site Evaluation Report/Wastewater Closure Plan for the C-. F-, K-, and P-Area Coal Pile
Runoff Basins (189-C. 289-F. 189-K, and J89-P) (U) (WSRC 1997b) was reviewed and approved by the EPA
and SCDHEC's Division of Site Assessment and Remediation and the Industrial, Agricultural and Storm
Water Permitting Division. Following the completion of the removal action, SCDHEC inspected the four
CPRBs and approved the final closure of these basins.
Based on the Post Removal Action/Remedial Investigation Report for the C-, F-. K-, and P-Area Coal Pile
Runoff Basins (189-C, 289-F. 189-K, and J89-P) (U) (WSRC 1997d), all low level threat source material
was removed. The operable unit poses no significant risk to human health or the environment. Therefore, a
determination has been made that No Further Action is required at the C-, F-, K-, and P-CPRBs and that
CERCLA Section 121 is not applicable to this No Further Action ROD.
The selected remedy is protective of human health and the environment, complies with Federal and State of
South Carolina requirements that are legally applicable or relevant and appropriate to the remedial action,
and is cost-effective. This No Further Action remedy is a permanent solution. Because this remedy does not
result in hazardous substances remaining on-site above health-based levels, the five-year review will not
apply to this action.
7/13 /If
Date Thomas F. Heenan
Assistant Manager for Environmental Quality
J. S. Department of Energy, Savannah River Operations Office
Date Richard D. Green v
; Division Director
Waste Management Division
U. S. Environmental Protection Agency - Region IV
1 1 /t* ft F /?.
Date R. Lewis Shaw
Deputy Commissioner
Environmental Quality Control
South Carolina Department of Health and Environmental Control
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DECISION SUMMARY
REMEDIAL ALTERNATIVE SELECTION (U)
C-, F-, K-, and P-Area Coal Pile Runoff Basins
(189-C, 289-F, 189-K, and 189-P)
WSRC-RP-97-850
Revision 1
July 1998
Savannah River Site
Aiken, South Carolina
Prepared by:
Wcstinghouse Savannah River Company
for the
U. S. Department of Energy Under Contract DE-AC09-96SR18500
Savannah River Operations Office
Aiken, South Carolina
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Record of Decision for the C-, f-. K-. and P-Anja Coal Pile Runoff Basins WSRC-RP-97-850
Savannah River Site Revision I
July 1998 Page ii of ix
DECISION SUMMARY
TABLE OF CONTENTS
SECTION PAGE
I. Savannah River Site and Operable Unit Name, Location, Description, and Process
History 1
II. SRS and Operable Unit Compliance History . 8
III. Highlights of Community Participation 11
IV. Scope and Role of the Operable Unit Within the Site Strategy 16
V. Operable Unit Characteristics 17
VI. Summary of Operable Unit Risks 21
VII. Remedial Action Objectives for the C-, F-, K-, and P-CPRBs Operable Unit 27
VIII. Summary of Comparative Analysis of the Alternatives 28
IX. The Selected Remedy 28
X. Statutory Determinations 30
XI. Explanation of Significant Changes 30
XII. Responsiveness Summary 30
XIII. Post-ROD Document Schedule 30
XIV. References 31
LIST OF FIGURES
Figure 1. Savannah River Site Map showing the Locations of C, F, K, and P Areas and Other Major SRS
Facilities 2
Figure 2. Location of the C-Area Coal Pile Runoff Basin in Relation to the Host Area. Pipeline, and Coal
Pile..! 3
Figure 3. Location of the F-Area Coal Pile Runoff Basin in Relation to the Host Area, Pipeline, and Coal
Pile 4
Figure 4. Location of the K-Area Coal Pile Runoff Basin in Relation to the Host Area, Pipeline, and Coal
Pile 5
Figure 5. Location of the P-Area Coal Pile Runoff Basin in Relation to the Host Area. Pipeline, and Coal
Pile 6
Figure 6. C-Area Coal Pile Basin Before, During, and After the Removal Action in 1997 12
Figure 7. F-Area Coal Pile Basin Before, During, and After the Removal Action in 1997 13
Figure 8. K-Area Coal Pile Basin Before, During, and After the Removal Action in 1997 14
Figure 9. P-Area Coal Pile Basin Before, During, and After the Removal Action in 1997 15
Figure 10. Flow Chan and Graphical Depiction of the Conceptual Site Model for a Typical CPRB Showing
Maximum Risk and Principal Driver for Potential Human Receptors 18
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Record of Decision for the C-. F-. K-. «nd P-Am Coal Pile Runoff Basins WSRC-RP-97-850
Savannah River Site Revision I
July 1998 Pafeiiiofiv
List of Tables
Table I. Summary of Historical Information and Site-specific Data for C-. F-. K-. and P-Area Coal Pile
Runoff Basins and Associated Facilities 7
Table 2. Summary of the Removal Action at the C-, F-, K-. and P-Area Coal Pile Runoff Basins 11
Table 3. Human Health Risk Summary for the K-CPRB - Future Exposures _ 22
Table 4. K-CPRB COCs and Risk/Based Remedial Goals 25
Table 5. Comparison of Average and Maximum Concentrations for the Soil COCs Below Clean Out
Elevation to the RGs and 2 X Mean Background Screening Levels 28
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Record of Decision for the C-. F-, K-. «nd P-Area Coal Pile Runoff Basins
Savannah River Site
July 1998
WSRC-RP-97-850
Revision I
Rape iv of iv
LIST OF ACRONYMS AND ABBREVIATIONS
ARARs Applicable or relevant and appropriate requirements
BEHP bis(2-Ethylhexyl)phthalatc
BRA Baseline Risk Assessment
C-CPRB C-Area Coal Pile Runoff Basin
CERCLA Comprehensive Environmental Response, Compensation and Liability Act
C-, F-. K-, and
P-CPRBs C-, F-. K-, and P-Area Coal Pile Runoff Basins
CMS Corrective Measures Study
CMS/FS Corrective Measures Study/Feasibility Study
COC Constituent of Concern
COPC Constituent of Potential Concern
CPRB Coal Pile Runoff Basin
CrVI Chromium VI
CSM Conceptual site model
DOE U.S. Department of Energy
DQO Data Quality Objectives
EPA U.S. Environmental Protection Agency
F-CPRB F-Area Coal Pile Runoff Basin
FFA Federal Facility Agreement
FS Feasibility Study
HI Hazard index
HQ Hazard quotient
K-CPRB K-Area Coal Pile Runoff Basin
MCL Maximum contaminant level
mg/kg Milligrams per kilograms
NCP National Oil and Hazardous Substances Contingency Plan
NEPA National Environmental Policy Act
NPL National Priorities List
OU Operable unit
P-CPRB P-Area Coal Pile Runoff Basin
PP Proposed Plan
PRA/R1R Post-Removal Action/Remedial Investigation Report
RCRA Resource Conservation and Recovery Act
RFI RCRA Facility Investigation
RG Remedial Goal
RI CERCLA Remedial Investigation
ROD Record of Decision
SB Statement of Basis
SCDHEC South Carolina Department of Health and Environmental Control
SCHWMR South Carolina Hazardous Waste Management Regulations
SRS Savannah River Site
SWMU Solid waste management unit
USC Unit-specific constituent
WSRC Westinghouse Savannah River Company
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Recent! of Decision for (he C-. F-. K-, and P-Atca Coal Pile Runoff Bairns WSRC-RP-97-850
Savannah River Site Revision I
July 1998 Page I of 32
SAVANNAH RIVER SITE AND OPERABLE UNIT NAME, LOCATION, DESCRIPTION,
AND PROCESS HISTORY
Savannah River Site Location, Description, and Process History
The Savannah River Site (SRS) occupies approximately 310 square miles of land adjacent to the Savannah
River, principally in Aiken and Bamwcll counties of western South Carolina. 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 (Figure 1).
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 and the space program.
Operable Unit Name, Location, Description, and Process History
The operable unit (OU) comprises the C-. F-, K-, and P-Area Coal Pile Runoff Basins (189-C, 289-F, 189-K.
and 189-P) (C-, F-, K-, and P-CPRBs). The Federal Facility Agreement (FFA) lists the C-, F-. K-, and P-
CPRBs as Resource Conservation and Recovery Act/Comprehensive Environmental Response, Compensation
and Liability Act (RCRA/CERCLA) units requiring evaluation to determine the actual or potential impact to
human health and the environment. Figures 2, 3, 4, and 5 show the location of each CPRB in relation to its
host area and associated facilities. Table 1 summarizes the historical information and site-specific data for
each CPRB.
The C-CPRB is located approximately 700 feet southeast of the limited area fence surrounding C Area
(Figure 2) in northwestern Bamwell County, South Carolina. Surface drainage in the area is southwest to
an unnamed, intermittent tributary of Fourmile Branch. The water table at the C-CPRB is approximately SO
ft below surface, and the flow direction is to the southwest at a gradient of 1.3 ft per 100 ft.
The F-CPRB is located approximately SO feet southeast of the limited area fence surrounding F Area
(Figure 3) in southwestern Aiken County. Surface drainage in southeastern F Area is toward the southeast
to an unnamed tributary of Fourmile Branch. The water table at the F-CPRB is approximately 80 ft below
surface, and the flow direction is to the southeast at a gradient of 1.5 ft per 100 ft.
The K-CPRB is located approximately 500 feet west of the limited area fence surrounding K Area (Figure
4) in northwestern Bamwell County. Surface drainage is toward the west-southwest to an unnamed
tributary of Indian Grave Branch. The water table is approximately 50 ft below surface, and the flow
direction is to the west-southwest at a gradient of 0.6 ft per 100 ft.
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Recofd of Decision for the C-. F-, K-. «nd P-Aiea Coal Pile Runoff Basins
Savannah River Site
July 1998
WSRC-RP-97-850
Revision I
Page 2 of 32
Figure 1. Savannah River She Map showing the Locations of C, F, K, and P Areas and Other Major
SRS Fadlities
0<2345 MILES
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Location
CArea
F Area
K Area
P Area
Period of
Powerhouse
Operation
1954-1984
1953-1984
1954-1990
1953-1990
Period of
Operation of
Coal Pile
Runoff Basin
1981-1985
1981-1985
1981-1990
1981-1990
Dale Coal
was
Removed
from Coal
Pile
Storage
Area
1985
1985
1997
1997
Coal Pile
Runoff Basin
Length x Width
x Average
Depth (ft)
Surface Area
(sqft)
Surface Area
(acres)
Capacity (gals)
170' x 170' x 4'
28,900 sq ft
0.66 acres
864,000 gals
270' x 270' x 5'
72,900 sq ft
1 .67 acres
2,727,000 gals
290' x 300' x 4'
87,000 sq ft
2.00 acres
2,603,000 gals
290' x 290' x 4'
84,IOOsqfl
1 .93 acres
2,5 17.000 gals
Pipeline
Length (ft) x
Diameter (in)
Depth of Burial
(ft)
Extension
during Removal
Action (ft)
I300'x 18"
3-8'
148 'added
across basin
900' x 30"
>T
No pipe added
I000'x30"
3.5-6.5'
348' added
across basin
530' x 36"
>2'
284' added
across basin
Coal Pile
Storage Area
Dimensions (ft)
Area (sq ft)
Area (acres) .
175' x 170'
30,000 sq ft
0.69 acres
400* x 275'
110,000 sqft
2.53 acres
480' x 250'
120,000 sqft
2.75 acres
480' x 250'
1 20,000 sq ft
2.75 acres
Typical Amount
of Coal in
Storage Area
(tons)
3,600
(from 1983 to
1985 contained
less than 1000
T)
10,000
16,000
(from 1990 to
1997 contained
less than 5000
T)
16,000
(from I99()to
1997 contained
less than 2000
T)
n
4 M
I
3
K
TO
O
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Record of Decision for the C-. F-. K-. «nd P-Ana Cot! Pile Runoff Basins WSRC-RP-97-8SO
Savannah River Site Revision I
July 1998 Page 8 of 32
The P-CPRB is located approximately 330 feet southeast of the limited area fence surrounding P Area
(Figure 5) in northwestern Bamwell County. Surface drainage is toward the southeast to Meyers Branch.
The water table is approximately 25 ft below surface, and the flow direction is to the southeast at a gradient
of 1.88 ft per 100ft.
Originally coal-fired power plants produced steam and electricity for Savannah River Site (SRS) activities.
Stoking coal was stored in unsheltered stockpiles at each of the power plant locations. CPRBs were
constructed in 1981 at C, F, K, and P Areas to protect surface water from coal pile contaminants such as
suspended solids, sulfuric acid, metals, radionuclides, and semi-volatile organic compounds. The power
plants at C, F, K, and P Areas have been inactive for several years.
II. SRS AND OPERABLE UNIT COMPLIANCE HISTORY
SRS Operational History
The SRS was created in 1951 with the primary mission of producing tritium, plutonium, and other special
nuclear materials for our nation's defense program. Production of nuclear materials for the defense program
was discontinued in 1988. SRS has provided nuclear materials for the space program, as well as medical.
industrial, and research efforts up to the present. Chemical and radioactive wastes are byproducts of nuclear
material production processes. These wastes have been treated, stored, and in some cases, disposed at SRS.
Past disposal practices have resulted in soil and groundwater contamination in some areas.
SRS Compliance History
Hazardous Waste handled at SRS is regulated under RCRA, a comprehensive law requiring responsible
management of hazardous waste. Certain SRS activities have required federal operating or post-closure
permits under RCRA. The SRS 1995 RCRA Renewal Permit (SCI 890 008 989) was issued on September 5,
1995 by the South Carolina Department of Health and Environmental Control (SCDHEC). Section IV of this
hazardous waste permit contains corrective action requirements for non-regulated solid waste management
units subject to RCRA 3004(u).
On December 21, 1989, SRS was included on the National Priorities List (NPL). This inclusion created a
need to integrate the established RCRA 3004(u) Program with CERCLA requirements to provide for a
focused environmental program. In accordance with Section 120 of CERCLA, DOE has negotiated a Federal
Facility Agreement (FFA) (WSRC 1993a) 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.
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Record of Decision for the C-. F-. K , and P-Area Caul Pile Runoff Basins WSRC-RP-97-850
Savannah River Site Revision I
July 1998 Page 9 of 3:
Operable Unit Compliance History and Removal Action
The C-, F-. K-, and P-CPRBs are listed in the FFA as RCRA/CERCLA units requiring evaluation to
determine the actual or potential impact to human health and the environment. The C-. F-, K-. and P-
CPRBs were combined in a single operable unit under the Removal Site Evaluation Report/Wastewater
Closure Plan for the C-. F-, K-, and P-Area Coal Pile Runoff Basins {I89-C, 289-F. 189-K. and I89-P) (U)
(WSRC 1997b) (RSER/WCP).
A RCRA Facility Investigation/CERCLA Remedial Investigation (RFI/RI) characterization was conducted
for the K-CPRB in 1994 and 1995. The RFI/RI and Baseline Risk Assessment (BRA) conducted on the K-
CPRB demonstrated that toxic metals, radionuclides, and semi-volatile compounds were largely confined to
coal-laden sediments in the basin. These constituents, concentrated in the 0.0-1.0 ft interval of coal-laden
sediments and soils within the basin, are naturally occurring constituents of coal. The results of the RFI/RI
and Baseline Risk Assessment (BRA) were presented in the RFI/RJ/BRA Report (WSRC 1997a). The
report was submitted in accordance with the FFA and the approved implementation schedule approved by
the EPA and SCDHEC in February 1997. In accordance with the FFA and the approved implementation
schedule, the Corrective Measures Study/Feasibility Study (CMS/FS) (WSRC 1997c) for the K-CPRB was
submitted by SRS and approved by EPA (June 13, 1997) and SCDHEC (August 7, 1997). A preliminary
RFI/RI/BRA (WSRC 19%) was also conducted for the C-CPRB, the development of this document was
discontinued after the RSER was approved with the K-CPRB as the lead site.
Because coal from the same sources was used in all four of these power plants and the CPRBs were all
located in similar upland soils, the contaminant suite, the distribution of the contaminants, and the risks and
hazards attributed to these contaminants are similar. The RFI/RI/BRA (WSRC 1997a) report for the K-
CPRB and the preliminary RFI/RI/BRA for the C-CPRB (WSRC 1996) document the similarity of
conditions in the two CPRBs. Thus it was not necessary to characterize the F- and P-CPRBs as rigorously
as the C- and K-CPRBs, resulting in a considerable reduction in the time necessary to effect remediation of
the four basins.
The coal-laden sediments and shallow soils were identified as low level threat source materials because the
material represented relatively low risks to humans and the ecology, had a low to moderate potential for
migration, and was easily contained or removed. Specifically, the risk assessment concluded that the
contaminants found in the 0.0-1.0 foot interval of basin sediments and soils contributed to a carcinogenic
risk of 6.0x10' to possible future on-unit residents via the shallow soil ingesiion pathway at the K-CPRB.
The carcinogenic risks to future on-unit residents from the contaminants in the coal-laden sediments via the
groundwater ingestion pathway based on the unit soil and groundwater data were calculated to be 7.0xlO'6.
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Recoil of Decision far the C-, F-. K-. and P-Aiea Coal Pile Runoff Basins WSRC-RP-97-850
Savannah River Site Revision I
July 1998 Page 10 of 33
Since the coal-laden sediments at the K-CPRB were determined to be the source of gross alpha
contamination to the shallow groundwater. and the coal-laden sediments at the other basins were determined
to be potential sources of groundwater contamination, it was appropriate to remove these low level threat
source materials. In addition to mitigating groundwater contamination, the removal reduced the risk
associated with exposure to sediment and near surface soils and is consistent with the statutory preference
for treatment and a desire to alleviate or minimize the need for engineering/institutional controls.
Working under the RSER/WCP. during the summer of 1997. SRS removed the coal-laden sediments and
soils in the C-, F-, K-, and P-CPRBs. The basins were backfilled to grade with clean soil. The remaining
coal was also removed from the K-Area Coal Stockpile under the RSER/WCP. Before the removal action
began, the remaining coal at the P-Arca Coal Stockpile was transported to an active SRS power plant as a
separate activity. The coal was removed from the coal stockpile areas in C and F Areas in 1985 (Table 1)
and the former storage areas were used for other purposes.
The 1997 removal action is summarized in Table 2. Figures 6 through 9 show photographs of the basins
before, during, and after the removal action. The 13,100 tons of coal, coal-laden sediment, and soils were
transported to Southeastern Soil Recovery, Inc. where the material was thermally treated. This facility was
approved under the CERCLA Offsite Rule. The residual material is being used for road base.
The C-, F-, K-, and P-CPRBs were cleaned out to a planar surface at least four feet below the proposed final
grade. All coal was removed from the C-, F-, K-, and P-CPRBs and the K-Area Coal Stockpile. This
eliminated the source of potential exposure to shallow soils for future industrial workers and on-unit
residents and the source of potential groundwater contamination at the C-, F-, and P-CPRBs. The
groundwater at the K-CPRB exhibits elevated gross alpha attributed to the operation of the K-CPRB. In the
case of the K-CPRB, the prior removal action should prevent further groundwater contamination. The
action completely removed at least the 0-1 foot interval, which contained the highest concentrations of the
constituents of concern (COCs) in the CPRBs. The basins were backfilled with a minimum of four feet of
clean native soil, eliminating the potential for exposure of future workers and on-unit residents during future
excavation activities. The backfill was graded to minimize ponding and to reduce infiltration and the
potential for erosion: a vegetative cover was established to prevent erosion.
The buried, reinforced-concrete pipelines, which had conveyed stormwater runoff from the coal stockpiles
to the CPRBs. were extended across the backfilled basins at the C-. K-. and P-CPRBs (Table 1) because
these pipelines were still being used to manage stormwater runoff from the former coal stock piles and
surrounding areas. After the coal was removed from the F-Area Coal Stockpile in early 1985, the upline end
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Record of Decision for the C-, F-, K-, and P-Area Cod Pile Runoff Basins
Savannah River Site
July 1998
WSRC-RP-97-850
Revision 1
Page II of 3:
Table 2. Summary °f tl»« Removal Actions at the C-, F-, K-, and P-Area Coal Pile Runoff Basins
Facility
C-CPRB
F-CPRB
K-CPRB
K-Coal Pile
P-CPRB
Stan Date
May 20, 1997
May 13, 1997
May 20, 1997
May 26, 1997
May 26, 1997
End Date
August 1. 1997
July 18, 1997
Septembers, 1997
Augusts. 1997
August 19. 1997
Coal-laden
Sediments and Soil
Removed (tons)
673.0
1725.0
2691.3
4536.5
3471.0
Fill Added (tons)
3300
16.050
15,300
1800
22.425
Totals 1 .5 tons per cubic yard 13,096.8 tons 58,875 tons
of the F-CPRB pipeline was plugged. During the removal action, the basin end of the line was plugged.
The F-CPRB pipeline is buried and will remain in place.
EPA approved the RSER/WCP on March 13, 1997. The RSER/WCP was also reviewed and approved on
April 25. 1997 by the Industrial, Agricultural and Storm Water Permitting Division of SCDHEC and by the
Federal Facility Agreement Section of the Bureau of Land and Waste Management of SCDHEC. On
October 6, 1997, the Lower Savannah Environmental Quality Control District of SCDHEC inspected the
C-, F-. K-, and P-CPRBs and approved the closure of the basins. The Statement of Basis/Proposed Plan for
the C-. F-. K-. and P-Area Coal Pile Runoff Basins (189-C. 289-F, 189-K, and 189-P) (U) (WSRC I997e)
(SB/PP) was approved by EPA on January 21, 1998 and SCDHEC on January 26. 1998.
III. HIGHLIGHTS OF COMMUNITY PARTICIPATION
Both RCRA and CERCLA require the public be given an opportunity to review and comment on the draft
permit modification and proposed remedial alternative. Public participation requirements are listed in
South Carolina Hazardous Waste Management Regulation (SCHWMR) R.61-79.124 and Sections 113 and
117 of CERCLA. These requirements include establishment of an Administrative Record File that
documents the investigation and selection of the remedial alternatives for addressing the C-, F-, K-. and P-
CPRBs soils and groundwater. The Administrative Record File must be established at or near the facility at
issue. The SRS Public Involvement Plan (PIP) (DOE, 1994) is designed to facilitate public involvement in
the decision-making process for permitting, closure, and the selection of remedial alternatives. The SRS
PIP addresses the requirements of RCRA. CERCLA, and the National Environmental Policy Act. 1969
(NEPA). SCHWMR R.61-79.124 and Section 117(a) of CERCLA, as amended, require the advertisement
of the draft permit modification and notice of any proposed remedial action and provide the public an
-------
Record ot"Decision lor ilic C-, K-, K.-, and P-Area Coal Pile RunotV Basins
Savannah River Sile
July 1998
WSRC-RP-97-850
Revision I
Page 12 of32
Figure 6.
C-Area Coal Pile Basin Before, During, and After the Removal Action in 1997
C Area Basin
(CPRB) - before
C Area Basin
(CPRB) - during
C Area Basin (CPRB) - after
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Record of Decision tor the C-, F-. K-, and P-Arca Coal Pile Rimoll Basins
Savannah River Sue
July 1998
WSRC-RP-97-850
Revision 1
Page 13 of32
Figure 7. F-Area Coal Pile Basin Before, During, and After the Removal Action in
1997
F Area Basin (CPRB) - before
F Area Basin (CPRB) - during
: '. :
"'; *x?llllpii
F Area Basin (CPRB) - after
-------
Record of Decision for ihe C-, F-, K-, and P-Area Coal Pile RimolT Bii
Savannah River Sue
July 1998
WSRC-RP-97-850
Revision I
Page 14 of 32
Figure 8. K-Area Coal Pile Basin Before, During, and After the Removal Action in
1997
K Area Basin (CPRB) - before
K Area Basin (CPRB) - during
K Area Basin (CPRB) - after
-------
Record ot"Decision lor llic C-. h-, K-, ;ind P-Arca Coal Pile RunolV Basins
Savannah Rivei Snu
July 1998
WSRC-RP-97-850
Revision I
Page 15 of32
Figure 9. P-Area Coal Pile Basin Before, During, and After the Removal Action in 1997
P Area Basin
(CPRB) - before
P Area Basin
(CPRB) - during
P Area Basin (CPRB) - after
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Record of Decision for (he C-. F-. K-. and P-Aita Coal Pile Runoff Basins WSRC-RP-97-850
Savannah River Site Revision I
July 1998 Page 16 of 32
opportunity to participate in die selection of the remedial action. The SB/PP, a part of the Administrative
Record File, highlights key aspects of the investigation and identifies the preferred action for addressing the
C-, F-. K-, and P-CPRBs.
The FFA Administrative Record File, which contains the information pertaining to the selection of the
response action, is available at the EPA Region IV office in Atlanta, Georgia, and at the following
locations:
U. S. Department of Energy Thomas Cooper Library
Public Reading Room Government Documents Department
Gregg-Graniteville Library University of South Carolina
University of South Carolina-Aiken Columbia, South Carolina 29208
171 University Parkway (803) 777-4866
Aiken, South Carolina 29801
(803)641-3465
Reese Library Asa H. Gordon Library
Augusta State University Savannah State University
2500 Walton Way Tompkins Road
Augusta, Georgia 30910 Savannah, Georgia 31404
(706)737-1744 (912)356-2183
The public was notified of the public comment period on the SB/PP through the SRS Environmental
Bulletin, a newsletter sent to approximately 3,500 citizens in South Carolina and Georgia. Notices were
also published in the Aiken Standard, the Allendale Citizen Leader, the Augusta Chronicle, the Barnwell
People-Sentinel, and The State newspapers. The public comment period was also announced on local radio
stations.
The 45-day public comment period began on February 12, 1998 and ended on March 28, 1998. No
comments were submitted on the SB/PP. A Responsiveness Summary, prepared to address public
comments, is usually provided in Appendix A of the ROD and in the final RCRA Permit: as no comments
were received on the SB/PP, Appendix A has been omitted from this ROD.
IV. SCOPE AND ROLE OF THE OPERABLE UNIT WITHIN THE SITE STRATEGY
The removal action at the C-, F-, K-, and P-CPRBs eliminated the potential for exposure of human and
ecological receptors to low level threat waste in shallow soils and removed the source of potential
groundwater contamination. Local groundwater at the C-, F-, K-, and P-CPRBs is not currently used as a
drinking water source. Based on the groundwater monitoring history at the C-, F-, and P-CPRBs, no
significant groundwater contamination has originated from these units. Gross alpha and the sum of radium-
226 and radium-228 have occasionally exceeded maximum contaminant levels (MCLs) in the water table
aquifer at the K-CPRB. These levels have shown a historical decline and with the source removed, the
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Record of Decision for the C-. F-. K-. and P-Aiw Coal Pile Runoff Basins WSRC-RP-97-850
Savannah River Site Revision I
July 1998 Page 17 of 32
expectation is that the sporadic exceedances will end. The No Further Action Alternative with confirmatory
groundwater monitoring at the K-CPRB (EPA 1991) is appropriate because the confirmation sampling will
address any remaining concerns.
The No Further Action Alternative means that no further remedial action will be performed on the CPRBs.
The waste has been removed and the Remedial Goals (RGs) have been met. The excavation has been
covered with at least four feet of clean soil backfill. The CPRBs are located in areas which have been
recommended for industrial use by the Citizens Advisory Board and the Savannah River Site Future Use
Project Report (DOE 1996).
V. OPERABLE UNIT CHARACTERISTICS
A conceptual site model (CSM) was developed for the K-CPRB to identify the primary sources, primary
contaminated media, migration pathways, exposure pathways, and potential receptors for the K-CPRB. The
K-CPRB CSM, modified for a typical CPRB, is presented in Figure 10. The RFI/RI/BRA Reports for the
C- (WSRC 1996) and K-CPRB (WSRC 1997a), RSER/WCP (WSRC 1997b), and PRA/RIR (WSRC
1997d) contain analytical data for all of the environmental media samples taken in the characterization of
the C- and K-CPRBs. The PRA/RIR documents the confirmatory data obtained during the removal action
at the F- and P-CPRBs. These documents are available in the Administrative Record (See Section III).
As previously stated in Section IV, the highest potential risk is primarily restricted to the coal-laden
sediments and shallow soils within the CPRB. The RSER/WCP summarized the groundwater monitoring
history at each of the four CPRBs and concluded that impacts on local groundwater had not exceeded
Primary Drinking Water Standards at any of the CPRBs except the K- CPRB. Confirmatory groundwater
monitoring and reporting for gross alpha and radium at the K-CPRB has been initiated with the scheduling
of second quarter 1998 sampling at the KCB monitoring wells.
CPRB Primary Sources and Release Mechanisms
The primary source of potential contamination was coal-laden stormwater runoff discharged to the CPRBs
from the coal storage areas via the gravity flow, reinforced-concrete CPRB pipelines (see Figure 12). After
the power houses became inactive, no new coal was delivered to the coal storage areas and the available
coal fines, which could be transported by stormwater runoff, were depleted from any remaining coal in the
storage area. Because of the large volumes of runoff that passed through the pipelines after the C-, K-, and
P-CPRBs became inactive, it is unlikely that any residual-coal remains in the pipelines.
-------
Rim any
Source
Primary
Release
MBchanism
Depasitioji
Pipeline to
K.Area
CoalPUe
Runoff Basin
Infiltration.'
Pcix-ohlion
Secondary
Source
Secondary
Release
Mechanism
Pathway
K-CPltB Risks to Potential Receptor
Current I Future
On-UaH On-Unil On-Unlt I
Vrfmr Workfr Residrnl I
D. , n .
1OsKU" C!S
TO
e
3
o
Sidintents
£o Surface
Soil
Volaliliiatiflii Air(\rajior) BJ Iidulatiaii fi-cOPfj Kr fOPCi N* rOPC»
u^ifr't Dtct
Generation
Air (Dust)
Dinct Canttct
Inhalation SE-10 2E-6 6E-6
In^fstion | 3E-8 I 6E-6 | 6E-5
j-T.uctMt
R
o
:? n
§ 00
a Wi
O
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Record of Decision for the C-. F-. K-. and P-Aita Coal Pile Runoff Basins WSRC-RP-97-850
Savannah River Site Revision 1
July 1998 Page 19 of 32
The primary release mechanisms are deposition inside the basin, deposition outside the basin from
overflow, deposition on the pipeline interior surfaces, and leakage of the pipeline (see Figure 12). The most
significant of these mechanisms is the release of unit contaminants as solid panicles to the sediments and
surface soil in the basin bottom.
CPRB Secondary Sources and Release Mechanisms
Secondary sources include the following media impacted by the coal-laden stormwater runoff: sediment
and shallow (0-1 ft) soil in the CPRBs, surface water in the basin that accumulates from precipitation and
runoff, surface and subsurface soil around the basin, and subsurface soil along the pipeline (see Figure 9).
The maximum concentrations of the major risk drivers such as arsenic and beryllium in the soils along the
C- and K-CPRfi pipelines are generally less than half the maximum concentrations found in the basin soils.
The highest risk to future residents from the soil along the K-CPRB pipeline is I x 10'5 due to ingestion of
excavated subsoil; the risk via all other exposure pathways is less than Ix 10"*. The highest hazard index
for the K-CPRB pipeline is 1.0 to the child-resident by subsoil ingestion. During the RFI/R1 at the K-
CPRB, no carcinogenic or radiological constituents of concern (COCs) were recognized in the soils of the
overflow area; only aluminum, antimony, and iron were identified as non-carcinogenic COCs. The hazard
indices to future workers and possible residents were less than 1.0. All constituents detected in the soils of
the C-CPRB overflow area were less than two times background or residential risk-based concentrations.
No action is warranted for the pipelines or overflow areas.
During the RFI/RIs conducted at the C- and K-CPRBs in 1994 and 1995, a total of five soil borings was
performed in each basin. The BRA determined that the constituents of concern (before the removal action)
for the K-CPRB soils were
aldrin (via groundwater ingestion),
antimony,
arsenic.
beryllium,
bis(2-ethylhexyl)phthalate (via groundwater ingestion),
chromium VI
radium-226, and
radium-228.
The COCs identified for the basin soils in the K-CPRB (antimony, arsenic, beryllium, chromium, radium-
226, and radium-228) are all natural trace element constituents of coal. The maximum concentrations of the
constituents of concern were confined to the 0-1 ft interval (removed under the RSER/WCP) with the
exception of radium-226 and radium-228. In the K-CPRB, the maximum values for radium-226 (0.97
pCi/g) and radium-228 (2.23 pCi/g) were found in the 1-3 ft interval and the 3-5 ft interval, respectively; 2
x average background values for radium-226 and radium-228 in the deep (>5 ft) soils near the K-CPRB
were 1.32 pCi/g and 2.4 pCi/g. Radium-226 is a daughter product of naturally occurring uranmm-238, and
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Record of Decision for the C-. F-. K-. end P-Ara Coal Pile Runoff Buins WSRC-RP-97-850
Savannah River Site Revision I
July 1998 Page 20 of 32
radium-228 is a daughter product of naturally occurring thorium-232. Both uranium-238 and thorium-232
are natural constituents of soils developed on the Coastal Plain sediments.
During the removal action, samples were collected from the 0-2 ft and 2-4 ft intervals below the cleanout
elevation in the F- and P-CPRBs. The maximum values for the COCs (WSRC 1997d) are all less the
maximum values reported from the 0-1 ft interval in the K-CPRB. The cleanout surface at each basin was
covered with at least four feet of clean backfill, eliminating all potential for exposure to the soil under the
future on-unit resident scenarios.
Secondary release mechanisms associated with these sources include direct contact, fugitive dust generation
from exposed surface soil, biotic uptake, and leaching to groundwater. The most significant of these
secondary release mechanisms are direct contact and leaching to unit groundwater. The quantified risks
associated with these and other exposure routes are summarized in Section VI.
At the K-CPRB, gross alpha has exceeded its MCL (15.0 pCi/L) in nine groundwater samples out of a total
of 18 analyzed for gross alpha from downgradient well KCB 3 since the first quarter of 1988. The
maximum value for gross alpha was 52.8 pCi/L in the third quarter of 1988; the most recent gross alpha
value was 17.5 pCi/L in the first quarter of 1996. The occurrence of elevated gross alpha is sporadic and
the levels appear to be declining (WSRC 1997b). Gross alpha has not exceeded its MCL in the other
downgradient wells (KCB 5 and 6). Many of the metals found in coal are in sulfide minerals; these
minerals weather to produce sulfuric acid. The sulfuric acid may accelerate the leaching of contaminants
from the coal-laden sediments or may leach contaminants from the Coastal Plain sediments, which are the
parent material of all the local soils. The alpha emitters (including radium-226) dissolved in the
groundwater may be from the coal or may have been leached from the Coastal Plain sediments by the acidic
coal pile leachate; in either case, removing the coal and sulfide minerals and reducing infiltration will
reduce the levels of alpha activity in the local groundwater.
Summary ofCPRB Primary and Secondary Sources
The characterization of the primary and secondary sources associated with the CPRBs indicates that the
principal human health risk drivers (arsenic and beryllium) are concentrated in the coal-laden sediments and
soil in the 0-1 ft interval restricted to the basins. Radium-226 and radium-228, which are the only
radiological risk drivers, are below the 2 x mean background screening criteria and are natural constituents
of both the coal-laden sediments and the underlying soils. No man-made radionuclides, organic
compounds, or metals were consistently identified in unirsoils at concentrations above screening levels that
would indicate contamination from unit operations.
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Record of Decision for the C-. F-. K-. and P-Anta Coal Pile Runoff Basins WSRC-RP 97-850
Savannah River Site Revision I
July 1998 Pap? 21 of 32
VI. SUMMARY OF OPERABLE UNIT RISKS
As pan of the investigation/assessment process for the K-CPRB. the lead site for the C-. F-. K-, and P-
CPRB operable unit, a BRA was performed using data generated during the assessment phase. Detailed
information regarding the development of COPCs, the fate and transport of contaminants, and the risk
assessment can be found in the RFI/RI/BRA (WSRC 1997a). The. risk assessment is based on conditions
that existed in the K-CPRB before the removal action. During the removal action. SRS completely
removed the 0-1 ft interval, containing the highest concentrations of the COPCs and covered the remaining
sub-basin soils with a minimum of four feet of clean backfill, eliminating the future residential exposure to
excavated soil scenario.
An exposure assessment was performed to provide an indication of the potential exposures that might occur
based on the chemical concentrations detected during unit-specific sampling activities. The current land use
scenario is an inactive industrial site. The only current exposure scenario identified for the K-CPRB was
for on-unit visitors, who may perform environmental research such as groundwater sampling on a limited
and intermittent basis at the K-CPRB. Conservative future exposure scenarios identified for the K-CPRB
included future on-unit industrial workers and future on-unit resident adults and children. The future
residential scenario includes homegrown produce as an exposure point, which is not considered under the
current on-unit visitor or future industrial worker scenarios. Risks and hazards from exposures under the
two land use scenarios at K-CPRB are presented in Figure 10 and Table 3. All risks and hazards to current
on-unit visitors were less than 1 x 10"6 and 1.0, respectively (Figure 10).
The media evaluated in the BRA include soil inside the K-CPRB, soil along the K-CPRB pipeline, and soil
in the K-CPRB overflow area. Aluminum, antimony, and iron were the only human health COPCs
recognized for the overflow area; these are all naturally occurring metals. Slope factors are not available
for these constituents. The overflow area does not represent significant risk or hazard to potential human or
ecological receptors, and no action is warranted for the overflow area. The calculated risks for the shallow
(0-1 foot) basin soils are evaluated under current and future land use scenarios in the following paragraphs.
Current Land Use - Carcinogenic Risks (K-CPRB)
Under the current land use scenario, human health risks were characterized for the current on-unit visitor
(see Figure 10). The highest estimated radiological cancer risk for any pathway was 3 x 10"8 from ingestion
of shallow (0-1 ft) basin soils, including the coal-laden sediments. This risk level is below the EPA point of
departure 1 x 10"6 and the risk range for NPL sites. Radiological cancer risks were not evaluated for current
on-unit visitors because no radionuclides were identified as COPCs.
-------
Table 3. Human Health Risk Summary For the K-CPRB - Future Exposures
Basin
Surface
Soil
(0-1 ft)
Basin
Deep
Soil
(0-5 ft)
Pipeline
Surface
Soil
(0-1 fl)
Pipeline
Deep
Soil
(0-5 ft)
Overflow
Area
Surface
Soil
Overflow
Area
Deep
Soil
Groundwater
Basin Soil
(0-1 fl)
Ingeslion of
Produce
Rasin Soil
(0-1 ft)
Air
(Paniculate
Inhalation
Basin)
Nonradiological Carcinogenic Risk
Future On-Unit
Worker
Future On-Unit
Resident
6x 10*
(ingested)
As 91%
6x 10s
(ingested)
As 91%
4x 10*
(ingested)
As 88%
3 x 10s
(ingested)
As 88%
6x I07
(ingested)
Be 100%
5 x 10*
(ingested)
Be 100%
1 x 10*
(ingested)
As 70%
Be 30%
1 x 10s
(ingested)
As 70%
Be 30%
NC
NC
NC
NC
2 x 10 ' (ingested)
Aldrin 49%
BEHP 42%
5x 10* Chloroform
(inhalation of VOCs)
7 x 10* (ingeslion)
Aldrin 49. BEHP 42%
NA
3 x I05
Fruit, Leafy,
Tuberous
As 98%
2 x 10*
(excavated)
Cr88%
6 x 10*
(excavated)
Cr88%
Radiological Carcinogenic Risk
Future On-Unit
Worker
Future On-Unil
Resident
NE
NE
2x IO'5
(external)
Ra-228
2 x 10'
(external)
Ra-228
NE
NE
NE
NE
NE
NE
NE
NE
2x 10 '(ingested)
Ra-22681%
4x 10 '(ingested)
Ra-226 83%
Ra-228 17%
NA
2x 10s
Total
Ra-228
1 x 10"
(excavated)
Ra-228
IxlO"
(excavated)
Ra-228
Noncarcinogenic Hazard
Future On-Unit
Worker
Future On-Unil
Resident
0.09
(ingeslion)
Fe 48%
As 38%
0.07
(ingeslion)
Fe49%
As 29%
0.7 0.5
Suit ingestion by Adult
2.0 2.0
Soil ingestion by Child
Fe 49% Fe 49%
As 38% As 38%
0.05
(ingeslion)
Fe86%
0.3 Adult
1.0 Child
Fe 86%
At 14%
0.05
(ingestion)
Fe 68%
Al 14%
0.3 Adull
1.0 Child
Fe 68%
Al 14%
As 10%
Sb8%
0.05
(ingeslion
)
Fe 90%
0.4 Adull
1.0 Child
Fe 90%
Al 10%
0.05
(ingestion)
Fe 89%
0.4 Adull
1.0 Child
Fe89%
Sbll%
2.0
(ingeslion)
Nitrate 5 1 %
Mn40%
6.0(Adull/ingeslion)
IO.O(Child/ingestion)
Nitrate 51%
Mn40%
NA
0.2 Adull
0.3 Child
Total
As 80%
Fe 16%
0.01
(excavated)
Mn 100%
0.02 Adull
0.07 Child
(excavated)
Mn 100%
ir
55?
*1
»&
'f
s-
n
i
o
VI
g
O
NA - Pathway not applicable for receptor. NC No risk calculated because slope factors are not available for COPCs
; number following the COPC indicates its contribution to the risk
NE - Pathway not evaluated for receptor.
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Reconl of Decision for the C-. F-. K-. and P-Aica Coal Pile Runoff Basins WSRC-RP-97-850
Savannah River Site Revision I
July 1998 Page 23 of 32
Current 1 -and IJse - Noncarcinogenic Hazards (K-CPRB)
Under the current land use scenario, noncarcinogenic hazards were characterized for the current on-unit
visitor. The RF1/RI/BRA (WSRC 1997a) shows that potential adverse noncarcinogenic health effects are
not likely to occur, because none of the hazard indices exceed a value of 1.0.
Future Land Use - Carcinogenic Risks (K-CPRB)
For the future on-unit worker, cancer risk from radiological constituents (naturally occurring radium-228)
exceeded the 1 x 10"6 risk level for external radiation. The highest risk was 2 x 105 for direct radiation
from excavated (0-5 ft) soils in the K-CPRB (see Table 3). Ingestion of radium-226 in groundwater drove a
risk of 2 x 105 for future on-unit workers. Cancer risks for nonradiological carcinogens were all between 1
x 10"* and 1 x 10~*. The highest risk for future on-unit workers was 6 x 10"* from ingestion of soil from the
0-1 ft interval. The risk from paniculate inhalation of excavated (0-5 ft) soil was 2 x 10"*. primarily driven
by chromium-VI (CrVI). The risk for ingestion of groundwater by future on-unit workers was estimated at
2x10"* driven by aldrin and bis(2-ethylhexyl)phthalate (BEHP). Aldrin was detected one time (J0.0164
ug/L in well KCB3). The "J" qualifier indicates that the analytical result is an estimated value: BEHP is a
constituent of vacuum pump oil and may be a laboratory contaminant.
For the future on-unit resident, cancer risks from exposure to external radiation exceeded the point of
departure (1 x 106) for K-CPRB excavated soils. Risks are estimated at approximately 2 x 105 (primarily
radium-228) for external radiation exposure. Radium-226 was the dominant contributor to a radiological
groundwater ingestion risk of 4 x 10'5. Cancer risks for nonradiological carcinogens exceeded 1 x 10"6.
The risk to future residents from the ingestion of shallow soil was estimated at 6 x 105 driven by arsenic.
The risk of 6 x 10"6 from inhalation of excavated K-CPRB soils is due primarily to CrVI. Groundwater
ingestion produced a risk of 7 x 10"6 driven by aldrin and BEHP.
Future Land Use - Noncarcinogenic Hazards (K-CPRB)
For the future on-unit worker, the hazard indices (His) were less than 1.0 for all constituents and exposure
pathways except groundwater ingestion (2.0) driven by nitrate and manganese. For the future on-unit
resident, the His were less than 1.0 for adult residents for all constituents and exposure pathways except for
groundwater ingestion (6.0) driven by nitrate and manganese. The HI for future resident children was 10.0
for groundwater ingestion, also driven by nitrate and manganese. Shallow-soil ingestion by future resident
children results in an HI of 2.0 driven by iron and arsenic.
Ecological Risk Assessment Results for the K-CPRB -
The ecological risk assessment evaluated the likelihood of adverse ecological effects from exposure to
chemicals associated with the K-CPRB. The ecological setting of the unit is not unique. There are no
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Record of Decision for the C-. F-. K-. and P-Area Coal Pile Runoff Basins WSRC-RP-97-850
Savannah River Site Revision I
July 1998 Page 24 of 32
known endangered, threatened, or special concern species on the unit, nor are the species that inhabit the
unit rare in the region or considered to be of special societal value. The area of the unit is small and the
habitat is low in diversity and productivity.
Based on characterization of the environmental setting and identification of potential receptor organisms, a
CSM for the K-CPRB (available in the BRA) was developed to determine the complete exposure pathways
through which ecological receptors could be exposed to COPCs. The focused evaluation addressed small
mammals inhabiting the unit (represented by the oldfield mouse).
Interpretation of the ecological significance of the unit-related contamination at the K-CPRB indicated thai
there was no likelihood of unit-related radiological or nonradiological constituents causing significant
impacts to biotic communities in the vicinity of the unit No ecological COCs were identified for the K-
CPRB.
COCs and Human Health Risk-Based Remedial Goals
Primary COCs in the human health risk assessment are defined as constituents that either individually
produce or significantly contribute to risk estimates that exceed a 1 x 10"4 risk or an HI of 3 by selecting
individual COCs exceeding a risk of 1 x 10 6 or a hazard quotient (HQ) of 0.1 in any pathway. Secondary
COCs which have a chemical-specific carcinogenic risk of at least 1 x 106 risk and a noncarcinogenic
hazard of 0.1 that contributes to a pathway hazard of 1.0 or greater. The K-CPRB soil poses a potential
threat to human health through exposure to five secondary COCs and the groundwater poses a potential
human health threat through exposure to two primary and 13 secondary COCs. The primary and secondary
COCs for the K-CPRB soil and groundwater are presented in Table 4.
Remedial Goals (RGs) are human health risk-based calculations performed on COCs which are primary
contributors of potential risk and/or adverse effects for the future resident scenario. Because the
hypothetical future scenarios usually yield the most conservative RG. future resident and on-unit worker
RGs are presented in Table 4 for the primary and secondary COCs identified for the K-CPRB soil and
groundwater.
Contaminant Threat Review
A review of the contamination present in the sediments and shallow soils within the CPRBs indicates that
these source materials are low level threat wastes. The sediments and shallow soils in the 0-1 foot interval
contained low concentrations of naturally occurring metals and radionuclides. which contributed to human
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Record of Decision for the C-. F-. K-. and P-Area Coal Pile Runoff Basins
Savannah River Site
July 1998
WSRC-RP-97-850
Revision I
Page 25 of 32
Table 4.
K-CPRB COCs and Risk/Based Remedial Goals
coc
Units
Primary Groundwater COCs
Manganese
Nitrate/Nitrite
mg/L
mg/L
RGs to Achieve
1 x 10* Risk
and 1.0 HI
Future Resident
Adult and Child
RGs to Achieve
1 x ICT" Risk
and 1.0 HI
Future On-unit
Worker
0.075
24.76
0.51
163.31
Maximum
Detected
Concentration
1.76
148
Secondary G'water COCs
Aldrin
Aluminum
Arsenic
Barium
Beryllium
Bis(2ethylhexyl)phthalate
Chloroform
Chromium (hexavalent)
Iron
Lead
Nickel
Vanadium
Zinc
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
3.9E-6
15.53
4.5E-5
1.062
1.5E-5
4.5E-3
8.3E-4
0.068
4.64
ND
0.31
0.108
4.67
ND
102.13
0.03
ND
ND
ND
ND
0.51
30.66
ND
0.72
ND
0.000016
62.3
0.012
0.46
0.003
0.033
0.0042
0.127
74.1
0.181
0.086
0.173
3
Secondary Soil COCs
Aluminum
Antimony
Arsenic
Iron
Vanadium
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
77649.4
30.53
18.64
22421.4
542.6
ND
ND
ND
ND
ND
18000
9.71
22.1
28500
121
ND
Not determined
health risks well below 1 X 10-3. These low level threat wastes have been completely removed from the
CPRBs and the basins have been backfilled to grade with clean soil.
Site-Specific Considerations
The RF1/RI/BRA was developed based on conditions that existed at the K-CPRB before the removal action.
The findings of the K-CPRB investigation indicated that a remedial action was apropriate to protect human
health and the environment. Site-specific considerations, based on the conclusions of the RFI/RI/BRA and
the PRA/RIR for the C-. F-. K-, and P-CPRBs, which indicate that risk to human health and the
environment has been effectively mitigated include:
1) The shallow basin soils (0-1 ft) represented the greatest risk at the K-CPRB. Arsenic contributed 91 %
of the greatest risk via soil ingestion, 6 x 105 for future on-unit residents (1 in 17,000 people would
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Record of Decision for die C-. F-. K-, «nd P-Am Coal Pile Runoff Basins WSRC-RP-97-850
Savannah River Site Revision I
July 1998 Pay 26 of 32
develop cancer due to exposure in a residential setting). Arsenic is a natural constituent of coal.
occurring in coal ash at an average of 500 parts per million (Mason 1966) or about 45.8 mg/kg in coal.
The average concentration of arsenic in the earth's crust is about 2 mg/kg. Arsenic was also widely
used as a pesticide by pre-SRS farmers. Beryllium, which contributed 9% of the soil ingestion risk to
future residents, is also enriched in coal: crustal abundance is 2.6 mg/kg, abundance in coal is 4.1
mg/kg. External radiation exposure, predominantly radium-228, resulted in a 2 x 105 risk for a
hypothetical future worker (i.e., 1 in 50,000 people would develop cancer due to exposure in an
industrial setting) and 2 x 105 risk for a hypothetical future resident. Radium-228 is a daughter of
naturally occurring uranium-238. The removal action conducted at the C-, F-, K-, and P-CPRBs during
the summer of 1997 removed the 0-1 ft interval, which contained the highest concentrations of the
COCs, and added four feet of clean fill above the remaining sub-basin soil. No Further Action is
necessary to protect human health or the environment.
2) The K-CPRB pipeline is buried beneath 3.5 to 6.5 feet of soil; thus soil contamination from pipeline
leaks is unlikely to be excavated under a residential setting. Carcinogenic and noncarcinogenic risks
posed by the pipeline soils are due to naturally occurring metals such as aluminum, antimony, arsenic,
beryllium and iron that are typical of coal and SRS soils. The shallow soils along the pipelines are
estimated to contribute low to nonexistent risk, 5 x 10"6 via ingestion to future residents and below 1 x
10"* and 1.0, respectively for future industrial workers. No Action is warranted at the K-CPRB
pipeline.
3) The only COPCs for the surface soils in the K-CPRB overflow area were aluminum and iron.
Carcinogenic risks for these constituents cannot be calculated because slope factors are not available.
The hazard index for future residents is 0.38. No Action is appropriate for the CPRB overflow areas.
4) The gross alpha groundwater contamination at the K-CPRB appears to be declining as discussed in
Section V. The coal-laden sediments were a source of sulfuric acid, radium-226, and other naturally
occurring alpha emitters. The coal-laden sediments have been completely removed, so the gross alpha
contamination in the groundwater should decline to below MCLs due to natural attenuation in the
aquifer. A five-year program of confirmatory groundwater monitoring at the K-CPRB will be
implemented with this ROD.
5) The C-, F- K-, and P-CPRBs are in areas which have been recommended as industrial in the Savannah
River Site Future Use Project Report (DOE, 1996), precluding future residential use.
6) The similarity of conditions at the C-, F-, and P-CPRBs to those at the K-CPRB facilitated the
consolidation of the C-, F-, K-, and P-CPRBs into a single operable unit with the K-CPRB as the lead
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Savannah River Site Revision I
July 1998 Page 27 of 32
site. No Further Action is the appropriate remedial action for the C-, F-, K-. and P-CPRBs. No Action
is appropriate for the pipelines and overflow areas.
VII. REMEDIAL ACTION OBJECTIVES FOR THE C-, F-, K-, AND P-CPRB OPERABLE
UNIT
Remedial action objectives specify unit-specific contaminants, media of concern, potential exposure
pathways, and remediation goals. The remedial action objectives are based on the nature and extent of
contamination, threatened resources, and the potential for human and environmental exposure. Initially,
preliminary remediation goals are developed based upon ARARs or other information from the
RFI/R1/BRA. These goals should be modified, as necessary, as more information concerning the unit and
potential remedial technologies becomes available. Final remediation goals will be determined when the
remedy is selected and shall establish acceptable exposure levels that are protective of human health and the
environment.
ARARs are those cleanup standards, standards of control, and other substantive requirements, criteria, or
limitations promulgated under federal, state, or local environmental law that specifically address a
hazardous substance, pollutant, contaminant, remedial action, location, or other circumstance at a CERCLA
site. The only ARARs associated with the C-, F-, K-, and P-CPRBs are MCLs for gross alpha, total
radium, and BEHP established under the Safe Drinking Water Act.
Threatened, endangered, or sensitive species are not found at the C-. F-, K-, and P-CPRBs and the unit does
not offer attractive or unique cover or forage opportunities for wildlife. Thus, ecological receptors are not
at significant risk from the C-, F-, K-, and P-CPRBs.
Soil COCs were identified in the RFI/RJ/BRA for the K-CPRB, which was the lead site for the removal
action. Table 5 compares the residual concentrations for the soil COCs after the removal action at each of
the CPRBs to the RGs and 2 x mean background screening values derived at the K-CPRB. The average
remaining concentrations of iron exceed the K-CPRB RGs in the F- and P-CPRBs; this may be due to
localized variations in the mineralogy of the subsoils. Iron is a natural constituent of subsoil minerals such
as plinthite. None of the maximum values for iron exceed the risk-based concentration for iron (610,000
mg/kg) for soil ingestion in an industrial setting. The maximum observed value for arsenic (J21.8 mg/kg) at
the P-CPRB slightly exceeds the RG (18.64 mg/kg). the "J" qualifier indicates that this is an estimated
value. This anomalous sample is from the 2-4 ft interval below clean out elevation and is now at least six
feet below restored surface. The removal action has met the RGs established for the unit COCs and No
Further Action is appropriate for the C-. F-. K-, and P-CPRBs.
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Record of Decision for the C-, F-, K-, and P-Arta Coal Pile Runoff Basins
Savannah River Site
July 1998
WSRC-RP-97-850
Revision I
Page 28 of 32
Table 5. Comparison of Average and Maximum Concentrations for the Soil COCs Below
Clean Out Elevation to RGs and 2 X Mean Background Screening Levels
Secondary Soil
COCs by CPRB
C-CPRB
Aluminum
Antimony
Arsenic
Iron
Vanadium
Units
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
RGs to Achieve
IxHT'Risk
and 1.0 HI
Future Resident
Adult and Child
77649.4
30.53
18.64
22421.4
542.6
2 x Mean
Background
Concentration
14050
2.04
1.64
21390
41.78
Average
Concentration
Below 1ft
Nondetects @
0.5 Detection
Maximum
Detected
Concentration
Below 1 ft
15890
3.024
8.12
14829
34.42
24200
6.31*
8.46
21400
49.8
F-CPRB
Aluminum
Antimony
Arsenic
Iron
Vanadium
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
77649.4
30.53
18.64
22421.4
542.6
14050
2.04
1.64
21390
41.78
22050
2.92
8.74
23316
52.4
35400
ND
ND
30300
71.5
K-CPRB
Aluminum
Antimony
Arsenic
Iron
Vanadium
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
77649.4
30.53
18.64
22421.4
542.6
14050
2.04
1.64
21390
41.78
7916
1.34
1.23
10927
28.01
18300
3.91*
4.58*
41300
121.0
P-CPRB
Aluminum
Antimony
Arsenic
Iron
Vanadium
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
77649.4
30.53
18.64
22421.4
542.6
14050
2.04
1.64
21390
41.78
26838
3.62
9.96
23883
53.47
75200
7.68
21.8
34000
74.9
' Only value above detection limit.
VIII. SUMMARY OF COMPARATIVE ANALYSIS OF THE ALTERNATIVES
After the removal of the source term, the only remaining viable alternative for remediating the C-, F-. K-,
and P-Area Coal Pile Runoff Basins is No Further Action. The components of the removal action are the
same as the most conservative alternative developed in the K-CPRB CMS/FS.
IX.
THE SELECTED REMEDY
The selected remedy is identical to the preferred alternative in the SB/PP (Section V, paragraph 3. WSRC
1997). After the removal action, the selected remedy for the C-, F-, K-, and P-CPRBs is No Further Action
with confirmatory groundwater monitoring at the K-CPRB (EPA 1991). The No Further Action Alternative
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Savannah River Site Revision I
July 1998 Page 29 of 32
means that no further remedial action will be performed on the CPRfis. The waste has been removed, the
RGs have been met. and the excavation has been covered with at least four feet of clean soil backfill. The
No Action alternative is appropriate for the CPRB pipelines and overflow areas.
The probable condition for the groundwater at all of CPRBs is no significant groundwater contamination
resulting from the operation of the CPRBs. As a result, no remedial action is deemed appropriate for the
water table aquifer at the CPRBs. However, annual confirmatory groundwater monitoring will be conducted
at the K-CPRB for a period of five years to ensure that No Further Action with confirmatory groundwater
monitoring at the K-CPRB is the appropriate remedy. SRS will notify SCDHEC and EPA within 30 days of
the second consecutive exceedance of MCL by any of the analytes. In the event that the probable condition is
no longer appropriate, DOE. SCDHEC, and EPA (the three parties to the FFA) will evaluate the need for
remedial action. There are no groundwater RAOs to be met for the water table aquifer at the K-CPRB since
the selected remedy for the aquifer is no remedial action with confirmatory groundwater monitoring.
The K-CPRB is the only basin where impacts on local groundwater quality due to the operation of the
CPRB have exceeded MCLs. Gross alpha and the sum of radium-226 and radium-228 have occasionally
exceeded maximum contaminant levels; bis(2-ethylhexyl) phthalate exceeded its maximum contaminant
level one time in a side gradient well. When the source material was removed from the basin, several of the
analytes (such as arsenic and vanadium) listed in the CMS/FS were reduced to near background levels and
were no longer a potential threat to groundwater quality. The following list of analytes will be monitored in
wells KCB 1, 3. 5, and 6 during the second calendar quarter of each year, beginning in the year (1998)
following completion of the removal action:
beryllium
bis(2-ethylhexyl) phthalate
chromium VI
gross alpha
radium-226
radium-228
pH
A summary report, including the data and interpretation, will be submitted to SCDHEC and EPA during the
first calendar quarter of the year following each monitoring event (the first report is due in January 1999).
If none of these constituents exceeds its MCL during five consecutive monitoring and reporting cycles, SRS
will request SCDHEC and EPA concurrence with suspending the monitoring program and decommissioning
the wells or dispositioning them to other programs. The cost of this groundwater monitoring and reporting
program will be approximately $60.200. No other costs will be incurred under the No Further Action
Alternative.
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Record of Decision for the C-. F-. K-. *nd P-Am Cot! Pile Runoff Basins WSRC-RP-97-850
Savsmuh River Site Revision 1
July 1998.
The No Further Action remedy for the C-, F-. K-, and P-CPRBs and the No Action remedy for the pipelines
and overflow areas are intended to be the final action for the C-, F-. K-. and P-CPRB operable unit. The
SCDHEC has modified the SRS RCRA permit to incorporate the selected remedy.
X. STATUTORY DETERMINATIONS
Based on the PRA/RIR for the C-. F-, K-, and P-CPRBs (WSRC 1997d), the OU no longer poses
significant risk to human health. Therefore, a determination has been made that the No Further Action
alternative for the CPRBs and the No Action alternative for the pipelines and overflow areas are protective
of human health and the environment, effective in both the long and short terms, comply with Federal and
State of South Carolina requirements that are legally applicable or relevant and appropriate to the remedial
action, and are cost-effective. Because no remedial action has been selected under this ROD, CERCLA
Section 121 statutory requirements are not appropriate.
Section 300.430 (f)(4)(ii) of the NCP requires that a five-year review of the ROD be performed if
hazardous substances, pollutants, or contaminants remain in the waste unit. The three Parties. DOE,
SCDHEC, and EPA, have determined that five-year reviews of the ROD for the C-, F-, K-. and P-CPRBs
operable unit will not be necessary to ensure continued protection of human health and the environment.
XI. EXPLANATION OF SIGNIFICANT CHANGES
The SB/PP and the draft RCRA permit modification provided for involvement with the community through
a document review process and a public comment period (February 12, 1998 through March 28, 1998). No
comments were received during the 45-day public comment period, thus there were no significant changes
to the selected remedy as a result of public comments.
XII. RESPONSIVENESS SUMMARY
No comments were submitted during the public comment period.
XIII. POST-ROD DOCUMENT SCHEDULE
This is a No Further Action ROD; thus post-ROD documentation is not necessary for this operable unit. A
summary report, including the groundwater data for the KCB monitoring well network and interpretation of
the data, will be submitted to SCDHEC and EPA during the first calendar quarter of the year following the
monitoring event.
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Record of Decision for ehe C-. F-. K-. and P-Area Co«J Pile Runoff Basins WSRC-RP-97-850
Savannah River Site Revision I
July 1998 Page 31 of 32
XIV. REFERENCES
DOE (U. S. Department of Energy) 1994. Public Involvement, A Plan for Savannah River Site. Savannah
River Operations Office, Aiken, South Carolina (1994).
DOE 19%. Savannah River Site Future Use Project Report. Stakeholder Recommendations for SRS Land
and Facilities (U). Savannah River Operations Office, Aiken, South Carolina (January 1996).
EPA 1988. Guidance for Conducting Remedial Investigations and Feasibility Studies Under CERCLA.
Interim Final. EPA/540/G-89-004, U.S. Environmental Protection Agency, Washington, DC.
EPA 1991. Guide to Developing Superfund No Action, Interim Action, and Contingency Remedy RODs.
EPA Publication: 9355.3-02FS-3, U.S. Environmental Protection Agency, Washington, DC.
Mason, B 1966. Principles of Geochemistry. Third Edition. John Wiley & Sons. Inc. New York.
WSRC 1992. RCRA Facility Investigation/ Remedial Investigation Work Plan for the A-.C-. D-. F~. H-.
K-, and P-Area Coal Pile Runoff Basins. WSRC-RP-90-585, Revision 1. Westinghouse Savannah
River Company. Aiken, South Carolina (January).
WSRC 1993a. Federal Facility Agreement for the Savannah River Site. Appendix C. Docket No. 89-05-
FF, WSRC-RP-94-42, Westinghouse Savannah River Company. Aiken, South Carolina (Effective
Date: August 16, 1993).
WSRC 1993b. RCRA Facility Investigation/RI Program Plan. WSRC-RP-89-994, Revision 1.
Westinghouse Savannah River Company, Aiken, South Carolina.
WSRC 1994a. Overall Strategy for the RCRA Facility Investigation/Remedial Investigation Work Plan for
the A-, C-, D-. F-. H-. K-. and P-Area Coal Pile Runoff Basins. WSRC-RP-94-968. Revision I.
Westinghouse Savannah River Company. Aiken, South Carolina (October).
WSRC I994b. Phase I RFl/RI Work Plan for the K-Area Coal Pile Runoff Basin. WSRC-RP-94-969,
Revision 0. Westinghouse Savannah River Company, Aiken, South Carolina.
WSRC 1995. Phase I RCRA Facility Investigation/Remedial Investigation for the C-Area Coal Pile Runoff
Basin (189-C). WSRC-RP-95-222, Revision 1. Westinghouse Savannah River Company, Aiken,
South Carolina.
WSRC 1996. RCRA Facility Investigation/Remedial Investigation and Baseline Risk Assessment for the C-
Area Coal Pile Runoff Basin (189-C) (U). WSRC-RP-96-155, Revision 1. Westinghouse Savannah
River Company, Aiken, South Carolina (December).
WSRC 1997a. RCRA Facility Investigation/ Remedial Investigation Report with the Baseline Risk
Assessment for K-Area Coal Pile Runoff Basin (189-K) (U). WSRC-RP-96-125, Revision 1.3.
Westinghouse Savannah River Company, Aiken, South Carolina (February).
WSRC 1997b. Removal Site Evaluation Report/ Wastewater Closure Plan for the C-.F-. K-. and P-Area
Coal Pile Runoff Basins (189-C, 289-F. 189-K, and 189-P) (U). WSRC-RP-96-897, Revision I.
Westinghouse Savannah River Company; Aiken, South Carolina (April).
WSRC I997c. Corrective Measures Study/Feasibility Study for the K-Area Coal Pile Runoff Basin (189-K)
(U). WSRC-RP-96-869, Revision 1.1. Westinghouse Savannah River Company; Aiken, South
Carolina (July).
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Savannah River Site Revision I
July 1998 Pay 32 of 32
WSRC 1997d. Post Removal Action/Remedial Investigation Report for the C-, F-. K-. and P-Area Coal
Pile Runoff Basins (189-C, 289-F. J89-K. and 189-P) (U). WSRC-RP-97-931. Revision 0.
Wcstinghouse Savannah River Company; Aikcn, South Carolina (November).
WSRC 1997e. Statement of Basis/Proposed Plan for the C-. F-. K-. and P-Area Coal Pile Runoff Basins
(189-C. 289-F, 189-K. and 189-P) (U). WSRC-RP-97-436, Revision 0. Westinghouse Savannah
River Company; Aiken, South Carolina (November).
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