PB95-964011
EPA/ROD/R04-95/218
March 1995
EPA Superfund
Record of Decision:
Savannah River Site (USDOE)
(O.U. 30), Aiken, SC
3/06/1995
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United States Department of Energy
Savannah River Site
Interim Action Record of Decision
Remedial Alternative Selection (U)
D-Area Oil Seepage Basin
WSRC-RP-93-1550
Revision 1
January 16, 1995
Westinghouse Savannah River Company £ ^~ ^ 1 %
Savannah River Site « ^ =J? ^ -
Aiken, South Carolina 29808 *Js^*J
^^^^H^H^I^BBB^^BHB^BB^HHHBI^I^^^HBM^BH^B^HI^I^B^^BBM^^^^ SAVANNAH RIVER SITE
PREPARED FOR THE U.S. DEPARTMENT OF ENERGY UNDER CONTRACT DE-AC09-89-SR18035
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WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
INTERIM ACTION RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION (U)
>-Area Oil Seepage Basin
Savannah River Site
Aiken County, South Carolina
Prepared by:
U.S. Department of Energy
Savannah River Operations Office
Aiken, South Carolina
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INTERIM ACTION RECORD OF DECISION WSRC-RP-93-1550, REV. 1
D-AREA OIL SEEPAGE BASIN JANUARY 16, 1995
DECLARATION FOR THE RECORD OF DECISION
Unit Name and Location
D-Area Oil Seepage Basin RCRA/CERCLA Unit
Savannah River Site
Aiken County, South Carolina
Appendix C of the Federal Facility Agreement (FFA) lists this Resource Conservation and
Recovery Act (RCRA)/Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) unit as the D-Area Oil Seepage Basin (Building Number 631-G).
Statement of Basis and Purpose
This document presents the selected interim remedial action for the D-Area Oil Seepage Basin at the
Savannah River Site (SRS), which was developed in accordance with CERCLA of 1980, as
amended, and to the extent practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP). This decision is based on the Administrative Record File for this
specific RCRA/CERCLA unit.
Assessment of the Unit
The D-Area Oil Seepage Basin unit is located in the southwest portion of SRS. The basin was
used for the disposal of waste oil originating from D-Area operations, to dispose of nonbumable
waste (drums, paint cans, metal objects, and rubber products), and for the routine burning of
office and cafeteria waste. Unknown amounts and types of waste were disposed into the basin.
A unit screening program was completed at the D-Area Oil Seepage Basin in November 1988. In
addition, a limited scope sampling event was conducted at the waste unit in 1993. Data collected
during both activities indicate the presence of hazardous substances in soils and groundwater at the
unit. Accordingly, a RCRA Facility Investigation (RFI)/CERCLA Remedial Investigation (RI)
Assessment Program is underway at the unit. In addition to the contaminated soils and
groundwater, there are hazardous substances associated with buried drums within the unit. The
principal threat source material includes subsurface hazardous liquids including drum contents,
pumpable free product, and discernible layers of sludges. If not removed, these substances pose a
threat of continued hazardous material release to basin soils resulting in potential further impact to
groundwater.
Description of the Selected Remedy
The preferred interim action alternative is Alternative 2, which consists of removal and
management of buried drum contents, pumpable free product, and discernible layers of sludge
present within the basin, and replacement of excavated soils. Large removable debris would be
excavated and dispositioned through the Treatment, Storage, and Disposal Facility (TSDF)
operated by the SRS Solid Waste and Environmental Restoration (SW&ER) Division. All
hazardous wastes generated during the interim action will be dispositioned through an SRS facility
that complies with the Off-Site Rule (58 PR 49200).
Declaration Statement
This interim action is protective of human health and the environment, complies with Federal and
South Carolina applicable or relevant and appropriate requirements (ARARs) directly associated
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INTERIM ACTION RECORD OF DECISION WSRC-RP-93-1550, REV. 1
D-AREA OIL SEEPAGE BASIN JANUARY 16, 1995
with this-limited scope action, and is cost-effective. The interim action involves no treatment of
affected soils or groundwater. However, disposition of the buried waste material and debris
excavated as part of the interim action, which may involve treatment, would be managed through
the SRS TSDF operated by SW&ER following approved methods and procedures. All applicable
Federal and state regulations will be followed. Since this action does not constitute the final
remedy for the D-Area Oil Seepage Basin waste unit, the statutory preference for remedies that
employ treatment that reduces toxicity, mobility, or volume as a principal element, although
partially addressed in this remedy, will be addressed by the final response action. Subsequent
actions are planned to address fully the threats posed by the conditions at this unit Since this is an
Interim Action Record of Decision, review of this unit and of this remedy will be ongoing through
implementation of the RFI/RI required in accordance with the terms of the FFA as the U.S.
Department of Energy, the U.S. Environmental Protection Agency, and the South Carolina
Department of Health and Environmental Control continue to develop final remedial alternatives for
the D-Area Oil Seepage Basin.
Date <7*vThomas F. Heenan
Assistant Manager for Environmental
Restoration & Solid Waste
U.S. Department of Energy
Savannah River OpdratioHfc Office
Date ^John H. Hankinson, Jr.
Regional Administrator
U.S. Environmental Protection Agency
Region IV
Date R. Lewis Shaw
Deputy Commissioner
Environmental Quality Control
South Carolina Department of Health and
Environmental Control
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WSRC-RP-93-1550, REV. 1
JANUARY 16,1995
DECISION SUMMARY
INTERIM ACTION
REMEDIAL ALTERNATIVE SELECTION (U)
D-Area Oil Seepage Basin
Savannah River Site
Aiken County, South Carolina
Prepared by:
U.S. Department of Energy
Savannah River Operations Office
Aiken, South Carolina
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INTERIM ACTION RECORD OF DECISION WSRC-RP-93-1550, REV. 1
D-AREA OIL SEEPAGE BASIN JANUARY 16,1995
DECISION SUMMARY
TABLE OF CONTENTS
Section Page
I. Site and Operable Unit Names, Locations, and Descriptions 1
n. Operable Unit History and Compliance History 1
ffl. Highlights of Community Participation 4
IV. Scope and Role of Operable Unit within the Site Strategy 5
V. Summary of Operable Unit Characteristics 6
VI. Summary of Operable Unit Risks 15
VII. Description of Alternatives 16
Vin. Summary of Comparative Analysis of Alternatives 20
EX. Selected Remedy 22
X. Statutory Determination 23
XI. Explanation of Significant Changes 23
XII. References 24
List of Figures
Figure 1. Location of the D-Area Oil Seepage Basin Waste Unit at the 2
Savannah River Site
Figure 2. D-Area Oil Seepage Basin Waste Unit 3
Figure 3. Locations of soil sampling conducted at the D-Area Oil Seepage 11
Basin waste unit during 1993
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INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16,1995
List of Tables
Table 1. Analytical results from sampling of three boreholes and a buried
drum at the D-Area Oil Seepage Basin waste unit from the 1988
field screening
Table 2. Range of soil concentrations of organic and metal constituents
determined from 1988 sampling at the D-Area Oil Seepage Basin
waste unit, compared with proposed RCRA soil action levels and
SRS soil background levels
Table 3. Analytical results from soil sampling at the D-Area Oil Seepage
Basin waste unit during 1993
Table 4. Summary of the Comparative Analysis of Considered
Interim Action Alternatives
8
12
21
Appendices
A. Implementation and Waste Management Strategies
B. Costs
C. Responsiveness Summary
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INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
I. Site and Operable Unit Name,
Lbcation, and Description
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.
According to 1990 census data, the average
population densities (in people/square mile) for
the surrounding South Carolina counties are
111 for Aiken County, 36 for Barnwell
County, and 28 for Allendale County, and for
the surrounding Georgia counties are 228 for
Columbia County, 524 for Richmond County,
25 for Burke County, and 21 for Screven
County. The population within a 50-mile
radius of SRS is 635,000 people.
SRS is owned by the U.S. Department of
Energy (DOE). Westinghouse Savannah River
Company (WSRC) provides management and
operating services for DOE. SRS has
historically produced tritium, plutonium, and
other special nuclear materials for national
defense. The Site has also provided nuclear
materials for the space program, and for
medical, industrial, and research efforts.
Chemical and radioactive wastes are
byproducts of nuclear material production
processes. Hazardous substances, as defined
by the Comprehensive Environmental
Response, Compensation, and Liability Act
(CERCLA), are currently present in the
environment at SRS. Appendix C of the
Federal Facility Agreement (FFA, 1993) lists
the D-Area Oil Seepage Basin waste unit
(Building 631-G) as a Resource Conservation
and Recovery Act (RCRA)/CERCLA unit.
The D-Area Oil Seepage Basin waste unit is
located in the southwest portion of SRS
between unimproved dirt Roads A-4.4 and A-
4.5, approximately one mile north of the coal-
fired D-Area Powerhouse (Figures 1 and 2)
and approximately 1.9 miles from the nearest
SRS boundary. For purposes of this interim
action, the D-Area Oil Seepage Basin operable
unit is defined as the proposed remedial action
that would result in the removal of suspected
drum contents and large debris within the waste
unit. This operable unit or discrete action will
allow for further characterization of the entire
waste unit.
The D-Area Oil Seepage Basin is located at an
elevation of approximately 150 feet above mean
sea level (Figure 2). Physiographically, the
basin is located on the Ellenton Plain, the
highest of three terraces between the Savannah
River to the west and the Aiken Plateau to the
east (Huber, Johnson, and Bledsoe, 1987).
The closest surface water feature is a Carolina
bay, a natural wetland, located approximately
175 feet west of the unit. The Carolina bay
appears to be dry during the summer months or
periods of little or no precipitation, but may
contain surface water during wet seasons. The
major surface water drainage system is the
Savannah River and associated swamps,
located approximately 1.3 miles to the west of
the basin (Figure 1). Upper Three Runs Creek
is located 1.7 miles to the north-northwest;
Fourmile Branch is 1.7 miles to the south-
southeast.
II. Operable Unit History and
Compliance History
Operable Unit History
Construction of the D-Area Oil Seepage Basin
trenches began in 1952. Employee interviews
indicated the basin was used in the disposal of
waste oil originating from D-Area Powerhouse
operations (Huber et al., 1987; Plunkett,
1993), to dispose of nonbumable waste
(drums, paint cans, metal objects, and rubber
products), and for the routine burning of office
and cafeteria waste. Unknown amounts and
types of waste were disposed into the basin.
No historical evidence of overflow of the basin
exists. Records of the contents of the disposed
drums do not exist. To date, there is no
evidence to indicate the presence of
radionuclides in the drums. Furthermore,
employee interviews have indicated that no
radionuclides were disposed within the
trenches (Plunkett, 1993).
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INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
-SRS BOUNDARY
SOUTH
CAROLINA
D-AREA OIL
SEEPAGE
BASK
SOUTH
CAROLINA
GEORGIA
SCALE IN MILES
Figure 1. Location of the D-Area Oil Seepage Basin Waste Unit at the Savannah River Site.
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ni
M
O
O
o
00
o
o
o
o
SITE
NORTH TRUE
NORTH
200
O
o
0
SCALE IN FEET
- WETLAND AREAS
200
o
o
i
A
t*
2 V9
Cw
o
o
o
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INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
In 1975, 'the D-Area Oil Seepage Basin was
removed from service and backfilled with soil
(WSRC, 1990). Approximately one foot of
standing liquid, plus an unknown number of
55-gallon drums possibly containing waste oil,
remained in the basin when it was backfilled.
The basin remains inactive and is covered with
natural vegetation, including bushes and
grasses, and is surrounded by trees.
Compliance History
Waste materials are managed at SRS that are
regulated under RCRA. Certain SRS activities
have required Federal operating or post-closure
permits under RCRA. SRS received a
hazardous waste permit from the South
Carolina Department of Health and
Environmental Control (SCDHEC) on
September 30, 1987. On December 21, 1989,
SRS was placed on the National Priorities List
(NPL). A site placed on the NPL comes under
the jurisdiction of CERCLA. In accordance
with Section 120 of CERCLA, DOE has
negotiated a Federal Facility Agreement (FFA,
1993) with the U.S. Environmental Protection
Agency (EPA) and SCDHEC to coordinate
cleanup activities at SRS into one
comprehensive strategy that fulfills RCRA
Section 3004(u) and CERCLA assessment,
investigation, and response action require-
ments. The FFA lists me D-Area Oil Seepage
Basin as a RCRA/CERLCA unit requiring
further evaluation using an investigation/
assessment process that integrates and
combines the RFI with the CERCLA Remedial
Investigation (RI) to determine the actual or
potential impact to human health and/or the
environment. This action is being carried out
in accordance with the requirements of the FFA
and the state and Federal RCRA permits.
The D-Area Oil Seepage Basin is listed as a
Solid Waste Management Unit (SWMU) under
both state and Federal RCRA permits. The
provisions of these permits require
investigation and implementation of corrective
measures, as necessary, for releases of
hazardous constituents from SWMUs. The
permits also provide for implementation of
interim measures to stabilize SWMU releases.
A unit screening program was completed at the
D-Area Oil Seepage Basin in November 1988
(WSRC, 1990). In addition, a limited scope
sampling event was conducted at the waste unit
in 1993. Data collected indicate the presence of
hazardous substances in soils and groundwater
at the unit. Accordingly, an RFI/RI Assess-
ment Program is required at the waste unit. In
addition to the contaminated soils and
groundwater, there are hazardous substances
associated with buried drums within the unit.
If not removed, these buried drums pose a
threat of contained hazardous material release to
basin soils resulting in potential further impact
to groundwater.
For remedial purposes, the D-Area Oil Seepage
Basin (corner boundary coordinates: E23995,
N68604; E23886, N68136; E23400, N68732;
E23127, N68306; see Figure 2), as bounded
by the markers, should be considered the waste
unit area. The area to be excavated, shown on
Figure 2, represents the location of suspected
and specific waste disposal activities.
III. Highlights of Community
Participation
Public participation requirements are listed in
Sections 113 and 117 of CERCLA. These
requirements include the establishment of an
Administrative Record File that documents the
selection of cleanup alternatives and provides
for review and comment by the public of those
alternatives. The SRS public involvement plan
(DOE, 1994) is designed to facilitate public
involvement in the decision making processes
for permitting, closure, and the selection of
remedial alternatives. The PIP addresses the
requirements of RCRA, CERCLA, and the
National Environmental Policy Act (NEPA).
Section 117(a) of CERCLA, 1980, as
amended, requires the preparation of a
proposed plan as part of the site remedial
process. The Interim Action Proposed Plan
(IAPP) (WSRC, 1994) for the D-Area Oil
Seepage Basin, which is part of the
Administrative Record File, highlights key
aspects of the assessment and investigation
phases of the remediation process and identifies
the preferred interim action alternative for
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INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
remediation of the D-Area Oil Seepage Basin.
The Administrative Record File, which
contains the information upon which the
selection of the response action was made, was
made available at the EPA-Region IV office and
at the following locations:
U.S. Department of Energy
Public Reading Room
Gregg-Graniteville Library
University of South Carolina-Aiken
171 University Parkway
Aiken, South Carolina 29801
(803) 641-3465
Thomas Cooper Library
Government Documents Department
University of South Carolina
Columbia, South Carolina 29208
(803) 777^866
Similar information was made available
through the following repositories:
Reese Library
Augusta College
2500 Walton Way
Augusta, Georgia 30910
(404) 737-1744
Asa H. Gordon Library
Savannah State College
Tompkins Road
Savannah, Georgia 31404
(912) 356-2183
The public was notified of the comment period
for the D-Area Oil Seepage Basin through
mailings of the SRS Environmental Bulletin, a
newsletter sent to more than 1400 citizens in
South Carolina and Georgia, and through
notices in the Aiken Standard, the Allendale
Citizen Leader, the Barnwell County Banner,
the Barnwell People-Sentinel, the North
Augusta Post, The State, and the Augusta
Chronicle newspapers.
The 30-day public comment period began on
August 15, 1994 for the LAPP for the D-Area
Oil Seepage Basin operable unit. The public
comment period was extended for 30 days until
October 13, 1994. A public meeting was held
on October 11, 1994. Written and oral
comments were accepted during this meeting.
Responses to comments are discussed in the
Responsiveness Summary (Appendix B).
IV. Scope and Role of Operable Unit
within the Site Strategy
This interim action addresses only the
remediation of the source material within the D-
Area Oil Seepage Basin waste unit. The
discrete action constitutes the first part of the
proposed strategy which would address the
principal threats posed by the waste unit. The
overall strategy of remediating the D-Area Oil
Seepage Basin waste unit is to: (1) perform the
proposed interim remedial action described
herein; (2) further characterize the waste unit
delineating the nature and extent of
contamination and identifying the media of
concern; (3) perform a baseline risk assessment
to evaluate media of concern, chemicals of
concern, exposure pathways and characterize
potential risks; and (4) evaluate and perform a
final action to remediate the identified
medium(s) of concern. The objectives in
developing interim remedial alternatives were to
evaluate interim actions that would address the
principal threat source material, subsurface
hazardous liquids including drum contents,
pumpable free product, debris, and discernible
layers of sludges. The alternatives would
result in buried drum content removal, to
prevent potential further releases, and provide a
drum- and debris-free environment for future
unit assessment studies. Providing a drum-free
environment and removing the large debris will
allow the RFI/RI characterization studies to
proceed more easily and safely and allow
subsequent development of final remedial
alternatives. Following the performance of this
interim action, further characterization, and a
risk assessment, a final action(s) will be
evaluated which addresses residual risk or
contamination. Additionally, a modification to
the Hazardous and Solid Waste Act/RCRA
permit will be accomplished during the final
action for the D-Area Oil Seepage Basin.
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INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
V. Summary of Operable Unit
Characteristics
Based on employee interviews, the D-Area Oil
Seepage Basin was constructed as at least three
separate unlined trenches, each divided by
berms. Approximate basin boundaries (Figure
2) were determined by ground-penetrating
radar (GPR) hi 1988 and 1992 and
magnetometer surveys in 1993. The three
suspected disposal trenches have total
approximate dimensions of 383 feet long, 108
feet wide, and 8 feet deep. Two additional
areas of disturbed soil were identified by GPR
and magnetometer measurements. The
westernmost disturbed soils area has
approximate dimensions of 100 feet long by 50
feet wide. The easternmost disturbed soils area
is approximately 75 feet long by 65 feet wide
(Figure 2).
Numerous buried drums and other material
were detected in the basin through GPR and
magnetometer studies. The drums have been
buried at least 17 years; therefore, their
condition is questionable. Visual inspection of
the drums has not been attempted. It is
assumed that intact drums (if any) may contain
free liquids and/or residual sludges. However,
until the drums are excavated this cannot be
verified.
The field geologic log associated with soil
sampling conducted in 1989 described the
occurrence of oil and the following additional
materials in soils collected within the basin:
ash, fired glass, burned soil, metal strips and
tubing, metal wire, electrical cable, asphalt,
concrete fragments, and lumber.
The soil types in and adjacent to the D-Area Oil
Seepage Basin waste unit have been identified
as fluvaquents (frequently flooded),
Udorthents, friable substratum, and Blanton
sand (WSRC, 1990). According to work
conducted by the U.S. Army Corps of
Engineers (COE) in 1952, the D-Area Oil
Seepage Basin is located on alluvial deposits of
Pleistocene age underlain by Tertiary age
deposits (McBean and Congaree Formations).
The alluvial sands, silts, and clays are
approximately 20 to 39 feet thick (Huber et'al.,
1987). No detailed geologic information is
available for the area surrounding the basin.
As a preliminary effort to characterize the
geologic and hydrologic conditions and to
monitor the water table elevation and
groundwater in the vicinity of the basin, three
monitoring wells (DOB-1, -2, and -3) were
installed in 1983 (WSRC, 1990). A fourth
well, DOB^l, was installed in 1984 (Figure 2).
Data collected from the four DOB wells at the
D-Area Oil Seepage Basin waste unit show that
the water table depth at this location varies from
approximately 4 to 20 feet bis, indicating
occasional saturated conditions within the
basin. Horizontal water table gradients
between wells and across the unit vary from 0
to 0.017 ft/ft based upon 1987 and 1988 data
(WSRC, 1990). The average horizontal
gradient is 0.0033 ft/ft. Potentiometric maps of
the water table at the basin indicate that
groundwater flow is often to the west-
southwest toward the Carolina bay. However,
groundwater elevation data from 1984 through
1989 indicate that the water table flow direction
changes, and at times, the flow is toward the
east-northeast. This does not appear to be a
seasonal variation in groundwater flow.
SRS Health Protection Department surveys
were performed hi 1991 and 1993 at the D-
Area Oil Seepage Basin waste unit, and
detected no radioactivity above background
(WSRC, 1990).
Average annual temperature at the SRS is
approximately 70°F (WSRC, 1990). Average
annual rainfall is approximately 43 inches.
In 1988, as part of an RFI/RI unit screening
program conducted at the D-Area Oil Seepage
Basin waste unit, three boreholes were drilled
through the basin fill to the water table
(WSRC, 1990). Debris was encountered
during this drilling activity and a drum was
punctured. Drilling was halted upon
encountering the drum. Liquid from the drum
was removed and analyzed. The detected
compounds included 1,1-dichloroethylene,
trichloroethylene, tetrachloroethylene, 2-
methylnaphthalene, fluorene, naphthalene,
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INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
phenanthrene, n-nitrosodiphenylamine, 4-
methyl-2-pentanone, acetone, ethylbenzene,
toluene, styrene, xylenes, and methylene
chloride (Table 1).
The primary contaminants detected in soils
collected from beneath the D-Area Oil Seepage
Basin waste unit in 1988 were metals, volatile
organic compounds, semi-volatile organic
compounds, and low levels of dioxins
(WSRC, 1990). Only one soil sample was
analyzed for metals. Metals found in
concentrations greater than analytical method
detection limits were silver, arsenic, barium,
chromium, copper, mercury, nickel, lead,
antimony, vanadium, and zinc (Table 1).
Several volatile and semi-volatile organic
constituents were detected in at least one soil
sample during the 1988 screening program
(Table 1; WSRC, 1990). Many of these
substances are fractional distillation products of
crude or coal tar oils and are components in
waste oil (e.g., methyl-naphthalene, chrysene,
fluoranthene, fluorene, toluene, naphthalene,
phenanthrene, pyrene, and xylenes). Bis(2-
ethylhexyl)- phthalate was frequently detected
hi die soil samples at elevated concentrations.
Phthalate species are used as plasticizers for
cellulose, glass, plastic, and rubber products.
Other substances detected, such as 4-methyl-2-
pentanone, acetone, methylene chloride,
ethylbenzene, and n-nitrosodiphenylamine, are
commonly used as solvents. Styrene, which
was detected in the buried drum sample, is
generally used hi resins or protective coatings.
Acetone and methylene chloride were also
detected frequently at low to moderate
concentrations hi the soil samples, but, because
these constituents were also detected hi quality
assurance/quality control samples and are
common laboratory contaminants, these
detections may be artifacts of the laboratory
process.
EPA has proposed corrective action
requirements for SWMUs at facilities
implementing corrective action under Section
3004(u) of RCRA (55 FR 30798; July 27,
1990). The proposed rules create a new
Subpart S in the RCRA Part 264 regulations
that would define requirements for conducting
remedial investigations, evaluating potential
remedies, and selecting and implementing
remedies at RCRA facilities. The corrective
action process under RCRA Subpart S would
parallel the process established for remedial
actions under CERCLA. Under the proposed
rules, EPA establishes action levels for certain
constituents that may trigger performance of a
Corrective Measures Study (CMS). Action
levels are media-specific, health- and
environmental-based levels determined by EPA
as indicators for protection of human health and
the environment. Where appropriate, action
levels are based on promulgated standards such
as maximum contaminant levels (MCLs) for
drinking water. Table 2 compares the
analytical results of soil samples collected
during 1988 from the three soil borings at the
unit and the proposed Subpart S action levels,
if available. The comparison of constituent
concentrations to promulgated and proposed
regulatory levels and background concen-
trations is provided to give a relative indication
of potential chemicals of concern. No
constituent detected in unit soils exceeds the
proposed action levels. Table 2 also provides a
comparison of unit soil metals concentrations
with SRS-wide background levels of metals in
soils. The comparison indicates that antimony,
chromium, copper, lead, and nickel exceed the
site-wide ranges for those constituents.
Radionuclide indicators (gross alpha, gross
beta, total radium, and tritium) were analyzed
in two soil samples (WSRC, 1990) and, at a
later date, the liquid from the buried drum
sample. No radionuclide indicators were
detected hi the soil or the drum sample.
A limited scope sampling event at the D-Area
Oil Seepage Basin waste unit was conducted on
September 28-30,1993. The primary objective
of the sampling was to confirm the presence or
absence of harmful levels of dioxins and furans
underneath the basin bottoms. The data
generated was also used to further delineate the
horizontal and vertical extent of contamination
from the 1988 unit screening. Additionally, the
data generated will be used to develop a site-
specific health and safety plan which will help
protect workers during excavation activities.
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Table 1. Analytical results from sampling of three boreholes and a buried drum at the
D-Area Oil Seepage Basin waste unit from the 1988 field screening.
Core
Interval No.
Depth, ft
Organics, ^ig/kg
2-Methylnaphthalene
Chrysene
Fluoranthene
Fluorene
Naphthalene
Pyrene
Phenanthrene
Bis(2-ethylhexyl)phthalate
n-Nitrosodiphenylamine
4-Methyl-2-pentanone
Acetone
Ethylbenzene
Toluene
Styrene
Xylenes
Methylene chloride
Metals, mg/kg
Silver
Arsenic
Barium
Chromium
Copper
Mercury
Nickel
Lead
Antimony
Vanadium
Zinc
DOSB-01
01 02 02S
11-12' 16-18' 16-18'
ND ND ND
ND ND ND
ND ND ND
ND ND ND
ND ND ND
ND ND ND
ND ND ND
59 2 ND
ND ND ND
ND 15 ND
150 45 ND
ND ND ND
130 32 ND
ND ND ND
ND ND ND
160 16 11
DOSB-02
02 03 04
6-7' 7-9' 18-20'
ND 2200 ND
ND 400 ND
ND ND ND
ND ND ND
ND ND ND
ND ND ND
ND ND ND
ND 1400 430
ND ND ND
ND ND ND
43 160 460
ND ND ND
35 170 110
ND ND ND
ND ND ND
45 210 150
0.94
0.72
54.00
194.00
122.00
0.23
17.00
183.00
23.00
2.80
116.00
DOSB-03
00 01D 02 03
Drum(|ig/l) 8-10' 16-18' 8-10'
73,000 16,000 1200 5900
ND ND ND ND
ND 70 ND ND
2300 140 ND 60
28,000 290 40 ND
ND 70 ND 50
4800 390 40 150
ND 13,000 90 2200
3500 420 ND ND
4,400,000 ND ND ND
1,200,000 480 170 450
570,000 94 ND 120
1,400,000 150 110 140
62,000 ND ND ND
3,400,000 ND ND 940
1,400,000 150 56 120
26
ND
13
49
32
0.21
ND
6
ND
ND
33
Cfl
»
o
in
S An "S" extension to the internal number indicates a split sample
D A "D" extension to the internal number indicates a duplicate sample
ND Not detected (below analytical detection limits)
VO*
(SI M
-------
INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
Table 2. Range of soil concentrations of organic and metal constituents determined from 1988
sampling at the D-Area Oil Seepage Basin waste unit, compared with proposed RCRA
soil action levels and SRS soil background levels.
CONSTITUENT
ORGANICS, mg/kg
2-Methylnaphthalene
Chrysene
Fluoranthene
Fluorene
Naphthalene
Pyrene
Phenanthrene
Bis(2-ethylhexyl)phthalate
n-Nitrosodiphenylamine
4-Methyl-2-pentanone
Acetone
Ethylbenzene
Toluene
Styrene
Xylenes
Methylene Chloride
METALS, mg/kg
Silver
Arsenic
Barium
Chromium (total)
Copper
Mercury
Nickel
Lead
Antimony
Vanadium
Zinc
Soil Sample Concentration
Minimum
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.01
0.94
0.72
54.00
194.00
122.00
0.23
17.00
183.00
23.00
2.80
116.00
Maximum
16.00
0.40
0.07
0.14
0.29
0.07
0.39
13.00
0.42
0.02
0.48
0.12
0.17
ND
0.94
0.21
0.94
0.72
54.00
194.00
122.00
0.23
17.00
183.00
23.00
2.80
116.00
EPA
Action Level^
NA
NA
NA
NA
NA
NA
NA
50
100
NA
8000
8000
20,000
20,000
200,000
90
200
80
NA
4003
NA
20
2000
cfifi4
JUU
an
j\J
XT A
NA
NA
SRS Soil Background
Levels^
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
0.01 - 1.80
<0.50 - 15.20
0.94 - 77.40
1.31 - 105.10
0.36 - 14.12
<0.01 - 0.89
0.11 - 17.90
<1.00 - 16.67
5.53 - 15.20
3.61 -72.11
1.80 - 267.00
2
3
4
NA
ND
EPA Proposed Corrective Action Rule for Solid Waste Management Units.
40 CFR § 264.521, Appendix A; 55 FR 30798, July 27, 1990.
Looney et al., 1990
Published action level for chromium (Cr) is for the Cr*6 oxidation state
(hexavalent form).
EPA, 1989b
Not available
Not detected (below analytical detection limits)
-------
INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
Fifteen soil borings were conducted during this
sampling event (Figure 3). The borings were
strategically located at known disturbed areas
and at the interface of basin bottoms and
sidewalls. Twelve of these borings collected
soil samples from 2-4, 6-8 and 12-14 feet bis.
Three borings were hand augered (for safety
purposes) directly into the basin bottom and
soil samples were collected from 2-4 and 6-8
feet bis. This resulted in a total of 57 discrete
samples collected including quality control
samples.
The analytical suites selected for this sampling
event included radionuclide indicators, dioxin
and furan homologues, and the target
compound list, target analyte list and library
scan for tentatively identified compounds.
The geological field logs indicated that oil
stained soils were evident in almost every
boring and in some samples to at least 14 feet
bis (the last interval sampled). Ash, burned
soil, wire, cable, rusted metal objects,
concrete, insulation, aluminum foil, plastic
sheeting and cloth were found in the drill
cuttings at a number of locations. Several
shallow borings had to be abandoned and re-
located because buried debris prevented the
hand auger from penetrating basin soils. One
boring, in particular, emitted a strong odor of
anaerobic decomposition indicating the
possibility of natural biodegradation.
The 1993 limited scope sampling detected a
wide variety of organic and inorganic
contaminants in basin soils, primarily in the
sampling intervals of 6-8 feet and 12-14 feet
bis. The predominant organic contaminants
detected in the sampling, pesticides, PCBs and
the congeners dibenzo-p-dioxin and dibenzo-p-
furan, are all characterized by being immobile
and persistent in the environment.
The most toxic compound detected was 2,3,7,
8-tetrachlorodibenzo-p-furan which was
present in two of the 57 samples. The most
commonly detected organic contaminant was
octochloro-dibenzo-p-dioxin which was
present in 37 of 57 samples.
Also identified were organic substances
identified as fractions of oil and oil compounds
including benzene, toluene, ethylbenzene,
xylene and naphthalene. The sampling also
detected low concentrations of the solvent
trichloroethylene and tetrachloroethylene.
Analytes with concentrations greater than
method detection limits are summarized in
Table 3.
Based upon observations in the field and
analytical results from the unit screening and
additional limited sampling, hazardous
substance contamination at the D-Area Oil
Seepage Basin waste unit extends from the
bottom of the basin at least 18 feet bis. In one
borehole, a bailed ground water sample
produced a film of free product floating on the
surface.
Monitoring well (DOB-1, -2, -3, and -4)
analytical results from 1984 to 1989 indicate
trichloroethylene and vinyl chloride
groundwater concentrations exceeding Safe
Drinking Water Act maximum contaminant
levels (MCLs; WSRC, 1990). Iron and
manganese groundwater concentrations
exceeded the Secondary Drinking Water
Standards. Additional groundwater data from
1989 to 1992 indicate the above constituents
continue to be detected.
The trenches at D-Area Oil Seepage Basin
waste unit, in total are approximately 383 feet
long, 108 feet wide, and 8 feet deep. The
volume of material within these trenches, based
solely on these dimensions, would be
approximately 12,300 cubic yards. Based on
interviews with site personnel, over 100 drums
primarily containing waste oil have been
disposed in the basin (WSRC, 1990). The
volume of buried debris is assumed to equal 20
percent of the basin volume or 2500 cubic
yards, leaving approximately 9800 cubic yards
of soil. The westernmost disturbed soil area
identified by GPR and magnetometer surveys
is approximately 100 feet long by 50 feet wide,
and the easternmost area is 75 feet long by 65
feet wide. It is not known whether waste
materials are present in these areas, and,
accordingly, no specific waste volumes are
estimated. However, assuming a depth of
disturbance similar to the depth of the trenches,
the total volume of material within the disturbed
10
-------
I
3
Ui
a
c
00 o
Co *
vo O
w >+>
ORANGE BALL
1
T3
w
m
D
I
I
B
?
^
P
O
&
w
I
I
tfl
I
K
ff
E 23141
£ 23741
N 68688
N 66638 -
N 68588 -
N 68538 -
N 68488 -
N 68438
E 23341
E 23441
- N 68688
- N 68538
- N 68488
N 68438
ORANGE BALL
o w
wo
O
z
8
-------
Table 3. Analytical results from soil sampling at the D-Area Oil Seepage Basin waste unit during 1993.
Analyte, mg/kg
ORGANICS
2-Methylnapthalene
Benzene
Benzo(g,h,i)perylene
alpha-Chlordane
gamma-Chlordane
Total chlordane
Chloroethene
4,4'-DDE
4,4'-DDT
Dieldrin
Heptochlorodibenzo-p-dioxin
Hexachlorodibenzo-p-dioxin
Octochlorodibenzo-p-dioxin
Pentachlorodibenzo-p-dioxin
Telrachlorodibenzo-p-dioxin
Ethylbenzene
2,3,7,8-Tetrachlorodibenzo-p-furan
Heptachlorodibenzo-p-furan
Hexachlorodibenzo-p-furan
Octochlorodibenzo-p-furan
Pentachlorodibenzo-p-furan
Tetrachlorodibenzo-p-furan
alpha-Hexachlorocyclohexane (lindane)
beta-Hexachlorocyclohexane(lindane)
Naphthalene
Bis(2-ethylhexy!)phlhalate
n-Butylbenzyl-phthalate
PCB 1254
PCB 1260
Total polychlorinated biphenyls
Tetrachloroethylene
Toluene
Trichloroethylene
Xylene, mixture
Hits
6/57
2/57
1/57
1/57
1/57
2/114
1/57
5/57
4/57
12/57
13/57
6/57
37/57
2/57
2/57
9/57
2/57
3/57
5/57
1/57
3/57
2/57
2/57
1/57
5/57
2/57
1/57
2/57
4/57
6/114
10/57
9/57
6/57
9/57
Mean
1.10
0.02
0.27
0.00263
0.00338
0.00601
0.00373
0.015456
0.008613
0.02
0.002623
0.0059
0.004197
0.0039
0.001
0.013691
0.0002
0.000833
0.00036
0.0004
0.000833
0.0005
0.0095
0.00263
0.58
0.11
0.10
1.13
0.86
0.95
0.14
0.04
0.08
0.0493
Minimum
0.163
0.0119
0.273
0.00263
0.00338
0.003
0.00373
0.00908
0.0014
0.00531
0.0001
0.0001
0.0001
0.0031
0.0005
0.00252
0.0001
0.0004
0.0001
0.0004
0.0004
0.0002
0.003
0.00263
0.247
0.111
0.0998
1.01
0.148
0.148
0.00416
0.00293
0.00361
0.0126
Maximum
1.65
0.0288
0.273
0.00263
0.00338
0.016
0.00373
0.0256
0.0208
0.0832
0.016
0.019
0.03
0.0047
0.0015
0.0415
0.0003
0.0013
0.0009
0.0004
0.0014
0.0008
0.016
0.00263
1.79
0.113
0.0998
1.25
1.22
1.25
0.462
0.104
0.356
0.12
ACTION LEVELS
RCRA
Subpart S 0
24
»
0.5
0.5
0.5
0.3684
2
2
0.04
0.0001
0.0047 t
8000
0.00005 *
'
0.1
4
50
0.09
10
20,000
60
200,000
PRO for Soil
mg/kg (chronic)
*
22.12
,
0.49
0.338
1.89
1.89
0.04
0.000103485
»
t
0.10
0.36
45.83
0.08
PRO for Soil
mg/kg (systemic)
*
16.47
137.22
13.72
*
27.443.61
t
10,977.44
5,488.72
54,887.22
t
54,887.22
548,872.18
UlM
-------
Table 3 (cont'd). Analytical results from soil sampling at the D-Area Oil Seepage Basin waste unit during 1993.
Analyte, mg/kg
TOTAL METALS
Aluminum
Antimony
Arsenic
Barium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Silver
Vanadium
Zinc
Hits
57/57
1/57
15/57
31/57
2/57
5/57
57/57
3/57
35/57
57/57
57/57
4/57
55/57
46/57
6/57
1/57
27/57
56/57
Mean
6005.667
8.4
2.137
166.423
2.6
4862
7.946
16.933
45.943
6870.68
11.628
3842.5
64.92
0.066
34.15
2.2
16.385
70.507
Minimum
489
8.4
1.1
21.3
2.5
1220
1.2
10.2
2.7
142
0.35
1150
2.7
0.023
5.2
2.2
5.4
2.5
Maximum
14,400
8.4
5.3
2380
2.7
9320
45.4
26
617
140000
210
7650
1710
0.318
62.2
2.2
55.4
1530
ACTION LEVELS
RCRA
Subpart S 0
3000
0.4
5600
40
t
400*
9
2960
500
24
1600
400
560
24,000
PRO for Soil
mg/kg (chronic)
t
0.37
t
*
t
PRO for Soil
mg/kg (systemic)
109.77
82.33
19,210.53
1,372.18
10,154.14
82.33
5,488.72
1,372.18
1,921.05
82,330.83
* Chromium (VI)
SOIL BACKGROUND
Analyte, mg/kg
TOTAL METALS
Aluminum
Antimony
Arsenic
Barium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Silver
Vanadium
Zinc
Looney »
Mean
11,697.41
<10.6
<2.0
16.43
<.60
16.41
<1.50
3.94
13,341.32
5.14
133.76
27.71
<.l
4.12
<1.00
27.80
12.39
Minimum
715.00
5.53
<0.50
0.94
0.12
1.31
0.46
0.36
885.90
<1.0
12.87
<1.6
<0.01
0:11
0.01
3.61
1.80
Maximum
53,530.00
15.20
15.20
77.40
1.19
105.10
5.27
14.12
79.600.00
16.67
759.40
498.20
0.89
17.90
1.80
72.11
267.00
Unit-Specific Background
Mean
10,110.00
24.00
13.35 .
5.87
14,587.50
2.40
*
16.60
0,05
t
33.40
6.13
Minimum
4,440.00
t
24.00
4.10
5.30
2,950.00
1.40
7.40
0.04
6.20
4.50
Maximum
13,700.00
*
24.00
*
17.90
*
6.30
22,500.00
3.20
26.40
0.06
48.30
7.70
W
HO
o
H
O
M*
Cfl
l-<
O
z
I
o
li
in M
-------
Table 3 (cont'd). Analytical results from soil sampling at the D-Area Oil Seepage Basin waste unit during 1993.
w^
S!
RADIOACTIVE SCREENING
Analyte, PCG
Radiation Indicators
Gross alpha
Non-volatile beta
Tritium
Looney «.
Mean
5.25
7.78
NA
Minimum
<4.0
<5.0
NA
Maximum
20.00
23.00
NA
D-Area Oil Seepage Basin Samples
Mean
8.33
10.71
21.68
Minimum
1.40
3.10
2.83
Maximum
35.90
40.70
42.70
0 All action levels were calculated based upon the recommended exposure assumptions and formulas (listed below) in Subpart S,
Federal Register, Vol. 55, No. 145, Appendix D, July 27,1990.
t Calculated values utilizing EPA, 1989a
oo Looney et al., 1990
Crt
93
O
M >-«
73 in
-------
INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
areas would amount to approximately 3000
cubic yards. Therefore, the total volume to be
excavated in the interim remedial action would
amount to 15,300 cubic yards.
VI. Summary of Operable Unit Risks
As required by CERCLA, a risk assessment
will be conducted based on characterization
data obtained during the RFI/RI unit
assessment following the interim action. This
risk assessment will provide the risk analysis
necessary to determine if additional remediation
is warranted to protect human health and the
environment. Development of future remedial
actions will be contingent upon further
characterization of the D-Area Oil Seepage
Basin waste unit, delineation of the nature and
extent of soil and groundwater contamination,
analysis of associated risks, and the RCRA
corrective action requirements.
Source Material of Concern. The D-Area Oil
Seepage Basin operable unit, as defined herein,
addresses as the source material of concern
drum contents and large debris, pumpable free
product or discernible layer of sludge, solid
waste, and other principal threat source
material. Groundwater and contaminated soil
layers encountered during the interim action are
beyond the scope of this interim action and will
be addressed during the RI/FS process. The
RI will further define the nature and extent of
contamination and the media of concern in the
waste unit. The future risk assessment will
address risk associated with exposure
pathways for each contaminated medium. It is
not anticipated that airborne contamination or
radioactive contamination will be a concern
during the interim action.
Potential Chemicals of Concern. For the
purposes of this operable unit, there are no
potential chemicals of concern (COCs). Since
the soils and groundwater are not addressed
under this operable unit, there are no potential
COCs for this action. Although there is
contamination in the soil and groundwater at
the D-Area Oil Seepage Basin, COCs will not
be defined for these media during this action.
COCs are defined for each environmental
media by comparison of contaminant levels
obtained during characterization activities to
background levels, health-based action levels,
and promulgated standards. COCs are also
developed in conjunction with the remediation
goals for the waste unit. Since soil and
groundwater characterization is not part of this
interim action, and PRGs have not been
developed, there are no COCs for this operable
unit. PRGs and COCs will be developed and
defined during the RI/FS.
The threat source materials being acted upon
during this interim action includes the waste
oils in the drums, free product and sludges
found in the trenches, and the removable
debris. See Section VII for a detailed
discussion regarding the quantity and types of
waste expected to be removed. Types of
contamination that may be encountered in the
source material include PCBs, dioxins, volatile
and semi-volatile organic compounds, and
polynuclear aromatic hydrocarbons (PAHs).
No radionuclide contamination is expected.
This information is based on previous sampling
activities. However, potential COCs for the
soils, which are not addressed by this interim
action, can be preliminarily identified based on
comparison of detected contaminants to
promulgated or proposed regulatory levels for
constituents in the environment or to SRS-wide
background levels (Tables 2 and 3). However,
no conclusions concerning potential COCs can
be made prior to performance of the risk
assessment, which would take into account
multiple contaminants and multiple exposure
pathways and will be performed during the
RI/FS.
Baseline. Exposure Scenarios. The proposed
interim remedial action would result in removal
of principal threat source material. As a
discrete action, the removal of drum contents
would lessen the risk to both human health and
the environment as leaching of drum contents
to soils and/or groundwater would be reduced.
Workers conducting the proposed interim
action would be required to adhere to an
approved Health and Safety Plan. Human
exposure to waste materials in a disposal
facility can occur only as a result of direct
contact and transport via surface, subsurface,
or atmospheric pathways. As part of the
15
-------
INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
RFI/RI.. assessment process, the risk
assessment will develop and evaluate exposure
scenarios.
Ecological Risks. The proposed interim action
will alleviate some risk from further
environmental impact through removal of drum
contents. Drum contents may pose the most
significant risk to the environment. Removal
of drum contents would reduce potential
leaching of contaminants to surrounding
environs. Identified baseline pathways which
could potentially impact the environment will
be evaluated during the RCRA/CERCLA
process, following implementation of the
proposed interim action.
VII. Description of Alternatives
Interim action alternatives were developed for
the D-Area Oil Seepage Basin that would result
in controlling impact to soils and/or
groundwater at the unit. The alternatives
presented in this IROD include:
Alternative 1
No Interim Action
Alternative 2
Buried Drum Content Removal with Soil
Replacement and Limited Debris Removal
and Disposition
The interim action alternatives are described
separately below. As required under
CERCLA, the no action alternative, Alternative
1, is included hi the evaluation as a baseline for
comparison.
As mandated under the FFA, a full' scale
RFI/RI and CMS/CERCLA Feasibility Study
(FS) will be conducted at the unit in the future.
Final remedial alternatives will be developed as
part of those activities.
The RFI/RI will begin in the fall of 1995 and a
final remedial action selection will be made in
approximately late 1998.
Alternative 1 - No Interim Action
Alternative 1 would include no interim removal
activities. Drums, debris, and contaminated
soils would be left in place at the unit.
Potential continued impact of soils and/or
groundwater could occur under this alternative
and the continued presence of drums in the
basin will interfere with planned assessment
activities.
Treatment Components. No treatment would
be implemented under Alternative 1.
Engineering Controls. No engineering controls
would be executed under this alternative.
Institutional Controls. Access to SRS is
controlled at primary roads by continuously
manned barricades. Other roads entering the
site are closed to traffic by gates or barriers.
The entire SRS facility is surrounded by an
exclusion security fence, except along the
Savannah River. The SRS is posted against
trespassing under Federal and state statutes.
Road A-4.4 provides access to the D-Area Ofl
Seepage Basin and is currently not access
controlled to onsite workers. Access to D Area
is, however, restricted from the general public.
No additional/new controls will be instituted.
Quantity of Waste. The D-Area Oil Seepage
Basin is approximately 383 feet long, 108 feet
wide, and 8 feet deep. The volume of material
within these trenches, based solely on these
dimensions, would be approximately 12,300
cubic yards. Based on interviews with site
personnel, over 100 drums primarily
containing waste oil have been disposed in the
basin (WSRC, 1990). The volume of buried
debris is assumed to equal 20 percent of the
basin volume or 2500 cubic yards. The
additional areas to be excavated of disturbed
soil identified by GPR and magnetometer
surveys is approximately 100 feet long by 50
feet wide and 75 feet long by 65 feet wide. It
is not known whether waste materials are
present in these areas and, accordingly, no
specific waste volumes are estimated.
However, assuming a depth of disturbance
similar to the depth of the trenches, the total
volume of material within the disturbed area
would amount to approximately 3000 cubic
yards. Under Alternative 1, all waste materials
and drums would remain in place until a final
16
-------
INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
remedy Devaluated.
Implementation Requirements. This alternative
is readily implementable.
Estimated Construction and Operation and
Maintenance Costs. No costs are associated
with implementation of this alternative.
ARARs Associated with the Considered
Alternative. Applicable or Relevant and
Appropriate Requirements (ARARs) are
Federal and state environmental regulations that
establish standards that remedial actions must
meet. There are three types of ARARs: (1)
chemical-specific, (2) location-specific, and (3)
action-specific. The three types of ARARs are
described in detail in Section ni.E. This
section sets forth major ARARs associated with
the remedial alternative.
No location-, action-, or chemical-specific
ARARs are associated with Alternative 1.
The only potential chemical-specific ARAR for
non-radioactive constituents in soils under
Federal and South Carolina regulations was for
PCBs. ARARs for PCBs are governed by the
Toxic Substances Control Act (15USC §§
2601-2671). For non-restricted access areas
(e.g., residential), the PCB cleanup standard is
10 nag/kg by weight, provided that the soil is
excavated to a minimum depth of 10 inches and
that the excavated soil is replaced with clean
soil (i.e., soil containing less than 1 mg/kg
PCBs). However, since no PCB congeners or
total PCBs hi excess of 10 mg/kg were detected
in soils and soil remediation is not part of this
operable unit, this ARAR does not apply to the
interim action for this unit.
Also, since no soil or groundwater treatment is
being proposed, MCLs as an ARAR, and
RCRA Subpart S as a "to-be-considered"
factor, do not apply.
Alternative 2 - Buried Drum Content
Removal with Soil Replacement and
Limited Debris Removal and
Disposition
Alternative 2 would involve an integrated
sampling, analytical characterization, and drum
content removal process. The objective of
Alternative 2 would be to provide a drum-free
waste unit which would allow subsequent
investigations and complete physical and
chemical characterization of the D-Area Oil
Seepage Basin. The overall process under
Alternative 2 would include uncovering of
buried drums from the waste unit and
transferring the drum contents to new drums
for management by the on-SRS TSDF operated
by SW&ER. Additionally, pumpable free
product or discernible layers of sludge, solid
waste, or other principal threat source material,
not including groundwater or contaminated soil
layers, encountered during the interim remedial
action would be pumped or placed into new
drums at the surface and managed by the TSDF
operated by SW&ER. The interim action will
adhere to all appropriate regulations.
Specifically, and for the purpose of this interim
removal action, drums, cans and other
excavated containers will be termed as
containers. These containers are defined as
follows:
1. Partially Full or Full Containers
a. Intact Containers - Excavated containers
that are unbroken and still retain at least
75% of their original holding capacity shall
be considered intact containers. Contents
shall be transferred into new drums by
practices commonly utilized for waste
removal. Not more than 2.5 centimeters of
waste (non-acutely hazardous) shall remain
in the bottom of any intact container to be
considered an empty container.
b. Crushed/Degraded Containers - Excavated
containers that are crumpled or crushed
more than 25% and not easily emptied by
practices commonly utilized to remove
waste would be considered debris.
Contents would be transferred into new
drums by practices commonly utilized for
waste removal.
2. Empty Containers (per 40 CFR § 261.7
and South Carolina Hazardous Waste
Management Regulations R.61-
79.261.7.b)
a. Intact Containers - Excavated containers
that are unbroken and that could still retain
at least 75% of their original holding
17
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INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
capacity, and having not more than 2.5
centimeters of waste (non-acutely
hazardous) remaining in the bottom shall be
considered empty containers. Empty
containers are not subject to regulation and
can be land disposed.
b. Damaged/Degraded Containers - Excavated
containers that would not satisfy intact
container criteria, or are crumpled or
crushed more than 25% would be
considered debris.
3. Container Fragments would be considered
as debris.
Management of debris is described further
below. Appendix A provides a decision tree
for the drum content management and debris
management under the Alternative 2 process.
Excavation activities will begin at the western
end of the "disturbed areas" and proceed
sequentially in discrete sections. The top two
to three feet of soil across the "disturbed areas"
or trenches is assumed to be relatively clean.
This top soil will be removed and placed
adjacent to the excavation for later use as
surface backfill. Excavation will continue with
the remaining soil temporarily placed within the
area of contamination, primarily on the
previously identified disturbed areas. As the
excavation proceeds through the disturbed
areas, the contaminated soils will remain in the
pit while continuously being displaced laterally
as backfill. Excavation activities would not
commence until the water table recedes to
below 3 m bis (10 ft). Should groundwater
infiltration occur during excavation, removal
activities would be suspended until the
groundwater recedes, and the regulatory
agencies would be notified.
For the purpose of this interim removal action,
debris shall be defined as Removable Debris or
Non-Removable Debris.
1. Removable Debris:
a. shall be defined as debris that would be
removed from the basin and dispositioned
according to hazardous or non-hazardous
debris determination using proper waste
identification techniques.
b. shall include large, man-made materials
visually located during the interim action
removal activity such as damaged/degraded
containers, metal piping, concrete, railroad
ties, rubber materials and cable.
2. Non-Removable Debris:
a. shall be defined as debris mixed with soil
that would be replaced with the excavated
soil into the basin prior to completion of
Alternative 2.
b. shall include basin aggregate (cobble);
small man-made materials such as nails,
broken glass, metal fragments, and other
man-made materials visually located during
the interim action removal activities.
Removable Debris encountered during
Alternative 2 would be determined to be either
hazardous or non-hazardous debris. This
determination would be based upon all proper
waste identification techniques utilized to
determine hazardous constituents such as visual
inspection, location, photo-ionization detection,
organic vapor analyzation, total petroleum
hydrocarbon field testing, Toxicity
Characteristic Leaching Procedure (TCLP)
testing of associated soils, and radiological
scanning.
1. Hazardous Debris - Removable Debris
determined through proper waste
identification techniques to be hazardous
shall be dispositioned through the TSDF
operated by the SRS SW&ER. Appendix
A provides the decision tree for
management of debris.
2. Non-Hazardous Debris - Removable Debris
determined through proper waste
identification techniques to be non-
hazardous can be land disposed.
Immediately following removal of drums, free
product, limited debris, and/or the sludge layer
at the bottom of the basins from the excavated
section, the excavated soil will be placed into
the excavation. The excavated soils will be
backfilled into the previous excavation(s) until
the soil is approximately one and one half feet
below average grade. As drums, free product
and/or limited debris are removed from the
disturbed area, a corresponding void space will
18
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INTERIM ACTION RECORD OF DECISION
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WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
result. At the end of removal activities, the
void will be apparent at the eastern end of the
trench in the form of a small pit. This pit will
be lined, backfilled with clean soil, and covered
with a polyethylene liner. The original top two
or three feet of clean soil will then be returned
to the top of the trenches. The area will be
graded across the disturbed area and seeded to
minimize rainwater infiltration and erosion.
Treatment Components. The interim action
itself involves no treatment of soils or
groundwater. Disposition of the drummed
waste material and removable debris, which
may involve treatment, would be managed
through the TSDF operated by SW&ER
following approved procedures (Appendix A).
Excavated drum contents, debris, and other
principal threat source material characterized to
be hazardous will be transported to the SRS-
operated storage facility for hazardous and
mixed waste. The SRS-operated storage
facility is a RCRA-permitted facility that
provides interim storage for hazardous waste
until it is transported off-site for final
disposition through one of several permitted
hazardous waste TSDFs. Specific TSDFs will
be determined at the time of disposal and be
dependent upon characteristics of the hazardous
waste.
Engineering Controls. Under Alternative 2,
approximately 12,300 cubic yards of material
(see Quantity of Waste) would be excavated
from the basin. However, the two areas of
disturbed soil would also be excavated and
would increase the total volume of soil to be
excavated to approximately 15,300 cubic
yards. Upon uncovering drums during
excavation activities, the drum contents would
be transferred to new drums which would be
stored in a temporary placement area. Drums,
soils, and debris would be covered and secured
at the end of a work day to prevent water from
entering the placement area. Each area would
be bermed and would be lined with a
polyethylene liner. Runoff control would be
accomplished by grading the ground surface
prior to excavation such that stormwater would
drain away from the excavation. A
containment dike around the outer perimeter of
the unit would be constructed to divert gradient
runon. Erosion control fences would be
established at the western extent of the unit to
prevent erosion runoff toward the Carolina
bay.
Institutional Controls. Public access to SRS is
controlled by existing security personnel and
security equipment as discussed under
Alternative 1.
Quantity of Waste. Because neither the
quantity of drums nor the volume of buried
debris is known, assumptions must be made
regarding the total number of drums and the
number of drums containing waste product in
the D-Area Oil Seepage Basin. For estimating
purposes, it is assumed that at least 100 drums
are buried at the D-Area Oil Seepage Basin
(WSRC, 1990) and that 50 of these drums
contain waste product. One hundred intact 55-
gallon drums would occupy approximately 27
cubic yards. It is also assumed that the volume
of buried debris is equal to 20 percent of the
basin volume, or 2500 cubic yards, leaving
approximately 9800 cubic yards of soil. The
additional areas of disturbed soil detected by
GPR may contain waste materials. Any
materials uncovered during excavation of those
areas would be managed as described for basin
materials.
Implementation Requirements. Standard
excavation equipment should be readily
available for implementation of this alternative.
New 55-gallon drums and materials needed for
the staging areas are also readily available.
Construction and removal activities are
projected to require between three and six
months, depending on the number of drums
encountered, weather conditions, and other
unpredictable factors. Plans are for the interim
action to be initiated in early 1995. This
proposed schedule meets the 15-month
regulatory requirement for remedial action
startup.
Estimated Construction and Operation and
Maintenance Costs. The costs for Alternative 2
are estimated to be $1,400,000 (Appendix
Table B.I). Costs include excavation and
drum content sampling/analysis activities.
19
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INTERIM ACTION RECORD OF DECISION
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WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
ARARs. .Associated with . the Considered
Alternative. No location- or chemical-specific
ARARs are associated with Alternative 2. As
with Alternative 1, because no soil or
groundwater treatment is being proposed,
MCLs and PCB ARARs along with RCRA
Subpart S as a "to-be-considered" factor, do
not apply. Action-specific requirements for
Alternative 2 include:
Occupational Safety and Health Admin-
istration (OSHA) Regulations 29 CFR §
1926 - Excavations
OSHA Regulations 1910.120 - Hazardous
Waste Operations and Emergency
Response
OSHA Regulations 1910.146 - Permit
Required Confined Space Entry
Land Disposal Restrictions regulations do not
apply to any interim action activities conducted
within the area of contamination.
Since the hazardous wastes generated during
the interim action will be dispositioned off-site,
as defined by 40 CFR § 300.5 of the NCP,
SRS will comply with the Off-Site Rule (52 FR
49200). All applicable requirements will be
met. Specifically, the off-site TSDF must
comply with the Land Disposal Restrictions
regulations. Prior to the transference of waste
materials, EPA and SCDHEC will be notified
of the specific receiving units and a full
demonstration of compliance will be
performed.
VIII. Summary of Comparative
Analysis of Alternatives
The National Contingency Plan (40 CFR §
300.430(e)(9)) sets forth nine evaluation
criteria that provide the basis for evaluating
alternatives and subsequent selection of a
remedy. The criteria are:
overall protection of human health and the
environment
compliance with applicable or relevant and
appropriate requirements (ARARs)
long-term effectiveness and permanence
reduction of toxicity, mobility, and volume
through treatment
short-term effectiveness
implementability
cost
state acceptance
community acceptance
Table 4 provides a summary of the considered
alternatives in relation to the nine NCP criteria.
Overall Protection of Human Health and the
Environment. Alternative 1 would not achieve
any reduction in potentially unacceptable health
risks posed by the D-Area Oil Seepage Basin.
Alternative 2 would offer reduction in human
health risk. Alternative 2 would involve an
interim remedial action whereby buried drum
contents and pumpable free product present
within the basin would be withdrawn and
properly managed. The alternative would
include excavation of removable debris
followed by proper management and
disposition. Backfill would be graded and
seeded to promote vegetative growth. The
effect would be to control infiltration and
inhibit migration of contaminants.
Environmental risks associated with D-Area Oil
Seepage Basin would continue to exist under
Alternative 1. Chemicals would continue to
leach into the groundwater and the resulting
contaminant plume will continue to migrate
from the D-Area Oil Seepage Basin.
Alternative 2 offers a reduction in risk to the
environment. Alternative 2 would provide
grading and seeding of backfill material to (1)
control infiltration of precipitation, thereby
minimizing contaminant migration; (2) prevent
wind dispersion of contaminants; and (3)
control erosion of soils.
Compliance with Applicable or Relevant and
Appropriate Requirements (ARARs'). The
purpose of this interim action is to remove the
source of contamination to soils and
groundwater (i.e., buried drums). Removal of
the drums from the basin will allow for
performance of an RFI/RI unit assessment,
which is essential for developing final remedial
alternatives.
20
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INTERIM ACTION RECORD OF DECISION
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WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
Table 4
Summary of the Comparative Analysis of Considered
Interim Action Alternatives
NCP Criterion
Overall Protection of
Human Health
Overall Protection of the
Environment
Compliance with ARARs
Long-Term Effectiveness
and Permanence
Reduction of Toxicity,
Mobility, or Volume
Short-Term Effectiveness
Implementability
Cost
State Acceptance
Community Acceptance
Alternative 1
No reduction in potential
risk to human health
No reduction in potential
risk to the environment
No location- or action-
specific ARARs associated
with the alternative; meets
identified chemical-specific
ARARs
Magnitude of risk would
eventually reduce through
natural attenuation
mechanisms; however, initial
risk would increase due to
continued leaching of
contaminants from buried
drums
Alternative 1 would offer no
significant reduction of
toxicity, mobility, or volume
of contamination
Offers no mitigation of
potential risks associated with
direct exposure to
contamination; poses no risk
to remedial workers or the
community upon
implementation
No implementation required
$0
State review of LAPP
completed
Public comment period
completed
Alternative 2
Reduces risk of exposure to
drum contents
Reduces risk of further
leaching of drum contents to
soils and groundwater
No location- or chemical-
specific ARARs; action-
specific ARARS include
OSHA 29 CFR § 1926,
1910.120, and 1910.146
Offers permanent solutions to
buried drum contents and
large debris; risk to human
health and the environment
would be reduced
Volume of drummed wastes,.
free product, and sludges
significantly reduced; no
reduction of contaminated
soil.
Reduces potential risks to
human health and the
environment associated with
direct exposure to drum
contents through removal;
risk to remedial workers
controlled through adherence
to an approved health and
safety plan; no risk to
community
Requires no special or non-
readily available equipment or
materials
$1,400,000
State accepted alternative
Public accepted alternative
ARARs - Applicable or Relevant and Appropriate Requirements
OSHA - Occupational Safety and Health Administration
1926 - Excavations
1910.120 - Hazardous Waste Operations and Emergency Response
1910.146 - Confined Space Entry
IAPP - Interim Action Proposed Plan (WSRC, 1994)
21
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INTERIM ACTION RECORD OF DECISION
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WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
Alternative;' 2 allows for the replacement of
contaminated soils within the designated area of
contamination. This interim action would be
accomplished to allow the RFI/RI unit
assessment to safely proceed.
No location-specific ARARs are associated
with the alternatives; however, erosion control
measures would be implemented during
Alternative 2 to mitigate impact to the adjacent
Carolina bay.
Action-specific requirements of Alternative 2
would be met through adherence to approved
site-specific procedures and a health and safety
plan.
Long-Term Effectiveness and Permanence.
The magnitude of risk associated with
Alternative 1 would diminish over time due to
natural attenuation of D-Area Oil Seepage Basin
constituents. Natural attenuation mechanisms
include effects of adsorption, dilution,
biodegradation, oxidation/reduction, and
hydrolysis. However, conditions would
deteriorate and potential risks to human health
and the environment would increase anytime a
drum containing pure waste product
deteriorates and releases the waste into the
environment. Many years would pass before
natural attenuation of D-Area Oil Seepage Basin
contaminants would reduce chemical
concentrations to acceptable levels. Alternative
2 offers permanent solutions for the
management of recovered drum contents and
pumpable free product encountered during the
excavation. The alternative offers the
management and disposition of removable
debris. Alternative 2 would offer the long-term
benefit of significantly reducing potentially
unacceptable risks associated with the D-Area
Oil Seepage Basin. Alternative 2 would not
result in removal of the entire source of
contamination.
Following performance of a complete RFI/RI
unit assessment, remedies could be developed
which offer potentially greater effectiveness at a
reduced cost. The objective of obtaining a
drum-free environment in the basin to allow
further assessment studies would be achieved
under Alternative 2.
Reduction of Toxicity. Mobility, or Volume.
The volume of drummed wastes, free product,
and sludges at the D-Area Oil Seepage Basin
would be significantly reduced under
Alternative 2. The mobility of remaining
contaminants would be minimized through
grading and seeding to limit soil erosion and
infiltration. Alternative 1 would offer no
immediate reduction of contaminant toxicity,
mobility, or volume. However, over time
natural attenuation would be expected to occur.
Short-Term Effectiveness. Implementation of
Alternative 2 would mitigate potential risks to
human health associated with direct exposure to
drum contents and free products at the D-Area
Oil Seepage Basin. Soil used to backfill the
basin would act as a protective barrier
preventing access to underlying soil
contamination. Alternative 2 would expedite
the permanent removal of drums containing
pure waste product from the basin.
Additionally, removed debris under Alternative
2 would be excavated, characterized, and
properly managed and disposed.
One drawback with regard to the short-term
effectiveness of Alternative 2 is the potential
increased human health risk associated with
exposure to contaminants during excavation,
treatment, and disposal of the buried drums and
debris and the contaminated soil; however,
adherence to an approved Health and Safety
Plan and engineering controls would mitigate
these effects.
Implementability. Alternative 1 does not
require implementation. Alternative 2 is readily
implementable requiring no special or non-
readily available equipment or materials.
Cost. The cost associated with Alternative 1 is
estimated to be $0. Costs for Alternative 2 are
estimated to be approximately $1,400,000.
State Acceptance. The state has reviewed the
IAPP and approved the selection of the
preferred interim action remedial alternative.
Community Acceptance. Community involve-
ment in evaluation of the proposed interim
action has included a 60-day public comment
22
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INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16, 1995
period and a public meeting held on October
11, 1994. Public comments were considered
and incorporated into this IROD. Discussion
of specific public comments and their
resolution are included in the Responsiveness
Summary (Appendix C).
IX. Selected Remedy
The preferred interim action remedial alternative
is Alternative 2 - Buried Drum Content
Removal with Soil Replacement and Limited
Debris Removal and Disposition. The
alternative consists of uncovering buried drums
through excavation, transference of drum
contents to new drums, and management of
drum contents by the TSDF operated by
SW&ER (Appendix A). Pumpable free
product, or discernible layers of sludge, solid
waste, or other principal threat source material,
not including groundwater or contaminated soil
layers, encountered during the interim remedial
action would be pumped or placed into new
drums at the surface and managed by the TSDF
operated by SRS SW&ER. Removable debris
at the surface would be characterized as either
non-hazardous or hazardous and dispositioned
through the TSDF operated by SW&ER
(Appendix A). Immediately following drum,
free product and/or limited debris removal from
the excavated section, the excavated soil will be
placed into the excavation. The soils will be
placed in the excavation such that the most
contaminated soils are at the bottom and the
clean soils are at the surface. The excavated
soils will be backfilled into the previous
excavation(s) until the soil is approximately one
and one half feet below average grade. As
drums, free product and/or limited debris are
removed from the disturbed area, a
corresponding void space will result. At the
end of removal activities, the void will be
apparent at the eastern end of the trench in the
form of a small pit. This pit will be lined,
backfilled with clean soil, and covered with a
polyethylene liner. The original top two or
three feet of clean soil will then be returned to
the top of the trenches. The area will be graded
across the disturbed area and seeded to
minimize rainwater infiltration and erosion.
The combined results of Alternative 2 would be
to remove a primary source of contamination
and allow for future unit assessment studies
essential for the development of final
alternatives.
Within 15 days of the signing (approval) of the
Interim Record of Decision (IROD), SRS will
submit an outline for the post-IROD
documents; the Remedial Design/Corrective
Measures Design and Remedial Action/
Corrective Measures implementation Plans.
The post-IROD documents will be submitted
within 30 days after the outline is approved by
EPA and SCDHEC. The interim remedial
action will begin after the post-IROD
documents are approved.
X. Statutory Determination
The preferred interim action remedial alternative
for the D-Area Oil Seepage Basin operable unit,
Alternative 2, addresses those principal threat
source materials, which are liquid or
concentrated hazardous substances mat may
readily migrate to subsurface soils and
groundwater. Buried Drum Content Removal
with Soil Replacement and Removable Debris
Disposition. This interim action will be
protective of human health and the
environment, will comply with Federal and
state ARARs, and will be cost effective. While
partially fulfilling the statutory preference for
remedies that reduce toxicity, mobility, and
volume, some contaminated material will be left
in place with this interim action alternative.
Subsequent investigatory actions are planned to
fully evaluate the risk to human health and the
environment posed by the remaining
contamination at the D-Area Oil Seepage Basin
waste unit to determine the necessary final
remedial actions for the unit.
XI. Explanation of Significant
Changes
Based upon the recent installation of a network
of piezometers and the ability to better monitor
and track local groundwater conditions, the
groundwater action level for commencement
and continuation of excavation activities as
defined under Alternative 2 has changed from
greater than 10 feet bis to greater than or equal
to 0.5 feet below the bottom of the basin
23
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INTERIM ACTION RECORD OF DECISION WSRC-RP-93-1550, REV. 1
D-AREA OIL SEEPAGE BASIN JANUARY 16, 1995
trench. .Local groundwater conditions will be
monitored with respect to the bottom of the
basin trench during excavation activities. This
change, and contingencies for various
groundwater elevations, are outlined in Section
6.0, Contingency Plan Implementation Strategy
of the Remedial Design/Remedial Action Work
Plan for the D-Area Oil Seepage Basin,
(WSRC, December, 1994).
XII. References
DOE (U.S. Department of Energy), 1994.
Public Involvement, A Plan for the Savannah
River Site. Savannah River Operations
Office, Aiken, South Carolina.
EPA (U.S. Environmental Protection Agency),
1988. Guidance for Conducting Remedial
Investigations and Feasibility Studies Under
CERCLA, Interim Final, EPA/540/G-
89/004, Cincinnati, Ohio.
FFA, Federal Facility Agreement for the
Savannah River Site, Administrative Docket
No. 89-05-FF, Effective Date: August 16,
1993.
Huber, L.A., W.F. Johnson, and H.W.
Bledsoe, 1987. Environmental Information
Document: Waste Oil Basins. DPST-85-
701, E.L du Pont de Nemours and
Company, Savannah River Laboratory,
Aiken, South Carolina.
Plunkett, R.A., 1993. D-Area Oil Seepage
Basin Interim Removal Personnel Interview:
Shepard Archie, CSWE (U), Memorandum,
WER-ERC-930445, Westinghouse Savannah
River Company, Aiken, South Carolina.
WSRC (Westinghouse Savannah River
Company), 1990. RCRA Facility
Investigation/Remedial Investigation Plan for
the D-Area Oil Seepage Basin, WSRC-RP-
90-704, Aiken, South Carolina.
WSRC (Westinghouse Savannah River
Company), 1994. Interim Action Proposed
Plan, D-Area Oil Seepage Basin (U), WSRC-
RP-93-703, Aiken, South Carolina.
24
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INTERIM ACTION RECORD OF DECISION WSRC-RP-93-1550, REV. 1
D-AREA OIL SEEPAGE BASIN JANUARY 16,1995
APPENDIX A
IMPLEMENTATION AND WASTE
MANAGEMENT STRATEGIES
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INTERIM ACTION RECORD OF DECISION
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WSRC-RP-93-1550, REV. 1
JANUARY 16,1995
ALTERNATIVE 2
IMPLEMENTATION STRATEGY
Interim Remedial
Action:
Treatability Study
Soil Left In
Place
Drum Content
and
Removable Debris Management
A-l
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INTERIM ACTION RECORD OF DECISION
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WSRC-RP-93-1550, REV. 1
JANUARY 16,1995
DRUM CONTENTS
(Drums Containing Oil)
Drums Sampled
(contain oil)
Send to TSDF
Temporary Storage
Until Treatment Option
is Available
Salvage Yard Handles
PCB Contaminated
Waste
Y
NOTE: SW&ER
provides treatment,
storage, and disposal
services for hazardous
and radioactive wastes.
Send to Power
Operations
Send to TSDF
Send to TSDF
Send to TSDF
Send to TSDF
A-2
-------
DEBRIS MANAGEMENT
CONTAINER
EXCAVATED
MATERIAL:
CONTAINER
OR DEBRIS
DEBRIS
ALTERNATIVE 2
REPLACE OR LEAVE
IN BASIN
OR
FULL/
PARTIALLY
FULL
OR EMPTY
INT ACT OR
DAMAGED/
DEGRADED
NON
REMOVABLE
ALTERNATIVE 3
MANAGE WITH
EXCAVATED SOILS
HAZARDOUS/
NON
HAZARDOUS
wQ
WO
o
w
n
00
>^
O
Z
I
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INTERIM ACTION RECORD OF DECISION
D-AREA OIL SEEPAGE BASIN
WSRC-RP-93-1550, REV. 1
JANUARY 16,1995
APPENDIX B
COSTS
-------
Table B.I D Area Oil Seepage Basin
Westinghouse Savannah River Corporation
Alternative 2 Drum Content Removal
Cost Estimate
Assumptions:
1)Suitable borrow material can be obtained onsite.
Page 1
2) Necessary borrow material volume is 1.50O cubic yards (382* x S3* x 2*}-
3)VoIume of drum contents, free product, and sludge removed 2750
(100 55 gallon drums; 50% capacity)
4) Cover and liner material need only be overlapped not welded.
5)2 Backhoes/1 Frontend Loader/4 Bobcats Used for Excavation
Item Quantity
Capital Costs
Site Preparation
Chain Link Fence 6 feet high; 6 ga. wire 1 .400
Drive thru Gate 16 feet 1
Construct Soil Staging Pad - 1OO* x 200*
Barrier Liner Material 40 mil Coaxil Liner 33.6OO
Soil Berm - 2* High 45
Cover Liner Material 40 mil Coaxil Liner 40.OOO
Construct Drum Staging Area 60* x 60*
Barrier Liner Material 4O mil Coaxil Liner 3600
Soil Berm - 2* High 18
Cover liner Material 40 mil Coaxil Liner 10000
Subtotal 1
Excavate Seepage Basin
Unearthing Drums Level C
Mobilization 1
Equipment Rental 300
Manpower 300
Segregate Debris 1.000
Subtotal 2
Waste Transfer & Removal
Personnel 6 People; 5 Drumss/Day; Level C 20
Transportation 3 Trucks 20
Per Diem . . 20
Misc. Expenses Pumps, Hoses. Supplies, etc. 1
New 55 Gallon Drums 22 Gauge Composite 50
Subtotal 3
Backfilling - Level D
Barrier Liner Material 40 mil Coaxil Liner 98.000
Cover Liner Material - 40 mil Coaxil Liner 98.000
Installation
Personnel 6 People; Level C 8
Transportation 3 Trucks 8
Per Diem 8
Misc. Expenses Pumps. Hoses. Supplies, etc. 1
Excavate and transport borrow soil
Backhoe - 0.75 CY. wheel mont. 1.500
Dump truck - 12 CY. 025 mi RT. 1.500
Spread borrow material 1 .500
Subtotal 4
gallons:
Units
Feet
Each
SF
CY
SF
SF
CY
SF
LS
HR
HR
CY
Day
Day
Day
LS
Each
SF
SF
Day
Day
Day
LS
CY
CY
CY
Unit
Costs($)
1239
218
0.19
10
0.19
0.19
10
0.19
2100
850
420
12
5.000
135
150
20.000
45
0.19
0.19
5.000
135
150
2,000
3.50
2.00
1.45
Total
Costsf$)
17.346
218
6.384
450
7.600
684
180
1.9OO
34.762
2.100
255.000
126.000
12.000
395.100
100.000
2.700
3,000
20.000
2.2SQ
127.950
18.620
18.620
40.000
1.080
1.200
2.000
5.250
3.000
2.175
91.945
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Table B.I D Area Oil Seepage Basin (Continued)
Westinghouse Savannah River Corporation
Alternative 2: Drum Content Removal
Cost Estimate
Item
Capital Costs (Continued)
Sampling & Analyses
TCLP (Full Scan)
Rash Point
PCBs
Dioxin/Furan
TOX
RCRA Metals
Gross Alpha
Gross Beta
Tritium
Subtotal 5
Sampling & Analyses Labor
Sampling S Samplers; 3 Samples/Day; Level
Transportation Truck
Per Diem
Misc. Expenses Supplies
Shipping 3 Coolers/Day._$7O/Cooter
Subtotals
Total Capital Costs (Subtotals 1 6)
Operation & Maintenance (1 Year)
Daily Inspection of Son Piles WSRC Employee
Fence Repair
Weed Control
Total Annual O&M Costs
PRESENT WORTH O&M COST (30 YRS. i=5%)
(Present Worth Factor «= 1S.S72)
Factored Costs
'Health and Safety
Bonds, insurance
Contingency
EngrJConst. Mgmt.
Prime Contractor Ovrhd & Prft
Total Factored Costs
Quantity
60
60
60
6
60
6O
60
60
60
C 20
20
20
20
20
50
4
4
5 % of capital costs
5 % of capital costs
15 % of capital costs
15% of capital costs
10% of capital costs
Units
Each
Each
Each
Each
Each
Each
Each
Each
Each
Day
Day
Day
Day
Day
Day
Qtr
Qtr
Unit
CostsfS)
1.500
33
250
1.100
50
275
45
45
45
2^00
45
75
450
210
90
300
5OO
TOTAL PRESENT WORTH COSTS (Capital + O&M + Factored)
Page 2
Total
CostsfS)
90.000
1.980
15.000
6.600
3.000
16.500
2.700
2,700
2.700
141.180
50.000
900
1.500
9.OOO
4.200
65.600
856.537
4.500
1,200
2.000
7.700
118.364
42£27
42327
128.481
128.481
85.654
428.269
1 1.403.170
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INTERIM ACTION RECORD OF DECISION WSRC-RP-93-1550, REV. 1
D-AREA OIL SEEPAGE BASIN JANUARY 16,1995
APPENDIX C
RESPONSIVENESS SUMMARY
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INTERIM ACTION RECORD OF DECISION WSRC-RP-93-1550, REV. 1
D-AREA OIL SEEPAGE BASIN JANUARY 16,1995
Responsiveness Summary
General Response
During the 30-day comment period, a request for a public meeting was received (ref. letter to Mr. H.
Homer from Ms. C. Lambert, 8/22/1994). The public comment period was extended an additional 30
days so the public meeting could be held. The public information meeting was held on October 11,
1994 in Aiken, South Carolina.
The public meeting was divided into three main segments: (1) a general introduction section, (2) a
discussion about the proposed TNX groundwater interim action, and (3) a discussion about the
proposed DAOSB interim action. The DAOSB discussion was broken into a general information and
background segment, a discussion and question/answer session about the proposed interim action and
finally an opportunity was provided for formal commenting. No formal comments were received at the
public meeting.
During the general discussion, many question were asked about the interim action. Questions raised
included general information questions regarding the physical state of the unit, how SRS was planning
to remove the drums, a general discussion of what options were reviewed and evaluated and how SRS
selected the preferred alternative. This discussion included a review of some of the options that were
not presented in the IAPP. A main topic of the discussion centered around why SRS was replacing the
soils and was not proposing to treat the excavated soils at this time. This question was also received as a
formal written comment during the public comment period. The- question and response can be found
below.
SRS stated that many treatment and storage options were reviewed. The main drawbacks of treating the
soil on site as an interim action were time and cost. SRS believes that the cost of constructing and
permitting an on site treatment facility (or bringing hi a portable treatment unit) would, at this time, not
be cost effective. The nature and extent of contamination is not known. Based on the data available, the
possibility exists that the soils may not warrant extensive treatment. On the other hand, if remedial
investigation may determine otherwise, we may have to treat more soil during the final action, it would
be more cost effective to wait and treat all the soils needing remediation at once. From the standpoint of
time, it may take up to 2 years to bring in a treatment system, get it permitted and operational. By the
time the system would be operational, SRS would be near completion of the R17FS process. The
treatment of the excavated soils is also out of the scope of the proposed interim action. Soil treatment is
more of a final action. A final action will be completed following the expedited RI/FS. See the specific
comments and responses for more detailed information.
Based on some of the discussions during the meeting and the comments received, it has become
apparent that including the incineration alternative in the IAPP has clouded the primary purpose for
proposing and performing the interim action. SRS agrees that the all or nothing approach to dealing
with the basin soils was not consistent with the interim remedial action objectives. Therefore,
alternative 3, excavation and incineration of basin soils, will be removed from the Interim Action
Record Of Decision.
During the public information meeting, suggestions were received on potential improvements to the
meeting format. These comments will be evaluated and to the extent possible, the recommendations
will be followed. Opportunities to provide for earlier public involvement through coordination with the
SRS Citizens Advisory Board (CAB) and/or holding public availability sessions are currently under
consideration. It is the goal of the three parties to the FFA to address these opportunities in the next
update to the SRS public involvement plan.
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INTERIM ACTION RECORD OF DECISION WSRC-RP-93-1550, REV. 1
D-AREA OIL SEEPAGE BASIN JANUARY 16,1995
Written comments were received from the following sources and the responses are below.
Ms. Carrie Lambert (requested the public meeting)
Ridgeland, SC
RPM, Inc.
Mr. George Robinson, President
Aiken, SC
Energy Research Foundation
Mr. Tim Connor, Associate Director
Columbia, SC
Plasma Chem, Inc.
Mr. W. Paul Stephens, President
Atlanta, GA
SPECIFIC COMMENTS
Comment
Plasma Chem, Inc.
Mr. W. P. Stephens
8/16/94 letter to SRS Remedial Project Manager, EPA - Region IV
Plasma Chem recommends the use of their smelting process (Ausmelt Furnace) for the destruction of the
waste material within the DAOSB trenches.
Response
SRS appreciates Plasma Chem's interest and suggestion, but since no treatment is being
recommended at this time, the potential use of the suggested equipment is not appropriate
for the interim action. SRS will evaluate the technology during the final RI/FS. Please
note, the CERCLA process details the technologies to be used for remediation. Most of
the time, especially with thermal technologies since there are many similar types of
equipment in the market, the CERCLA does not specify specific brands of equipment.
This is done through procurement.
Comment
RPM, Inc., 9/8/94
Ref. letter from G.C. Robinson, RPM, Inc.
"In the Savannah River Site Environmental Bulletin dated August 8, 1994 there is a release plan for the
D-Area Oil Seepage Basin. After reading and evaluating the problem RPM believes we have possible
innovative technologies that could be applied to the project allowing significant cost and time savings.
Our approach would be to solidify the oil and sludge material into non-metallic containers and totally
remediate the area...Realizing that the EPA and DOE are seeking innovative technologies to apply in
solving environmental problems, RPM's method of cleaning up D-Area Oil Seepage Basin is a viable
alternative to the three methods presented in the Environmental Bulletin...." (ref. RPM letter)
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INTERIM ACTION RECORD OF DECISION WSRC-RP-93-1550, REV. 1
D-AREA OIL SEEPAGE BASIN JANUARY 16,1995
Response'
RPM's proposed innovative technology for remediating the D-Area Oil Seepage Basin
(DAOSB) has been reviewed by SRS and at this time, it is believed to be inappropriate
for the proposed interim action.
The proposed 'innovative technology' is in essence a basic stabilization technology that
uses a unique container to receive the stabilized material.
From the point of view of stabilization, it may advantageous to stabilize the DAOSB
material in place. Using the RPM method, the material would have to be removed,
stabilized and then stored or disposed in a permitted facility. The proposed stabilization
method would require more handling (potentially posing more of a threat to human
health) and potentially cost more than another stabilization process due to the cost of the
containers and the storage or disposal cost (versus in situ stabilization). Stabilization has
been proven to be somewhat ineffective on volatile organic compounds. Because the
characteristics of the waste material are not fully defined, stabilization may not be
needed; it is possible that only containerization is needed to store the material.
From a CERCLA standpoint, it is better to destroy and/or reduce the toxicity and/or the
volume of material than it is to reduce its mobility. While most stabilization technologies
increase the volume of material an average of about 30%, it appears that the RPM
technology doubles the amount of waste material that must be stored or disposed. Other
potential technologies exist for DAOSB that will treat/destroy the waste materials.
As part of the final CERCLA Remedial Investigation/Feasibility Study (RI/FS) process,
in which a final remedial action will be chosen for the DAOSB, a full range of
technologies, including destructive technologies and stabilization technologies, will be
evaluated based on the CERCLA criteria. SRS is proposing only an interim action at this
time, not a final action. Since the type and extent of waste in the basin have not been
fully characterized, it may not be prudent, or cost effective, at this time to treat all of the
basin soils.
When the final remedial actions are being developed and evaluated for the DAOSB, SRS
will be pleased to fully evaluate RPM's technology.
Comment
Energy Research Foundation (ERF), 9/8/94
Mr. Tim Connor, Associate Director
1) While the excavation of the contaminated soils is necessary to remove the drums, it does not follow
that they should be replaced in the manner described in Alternative #2.
It is plausible, based on the yet to be completed RFI/RI assessments (which presumably would
incorporate future land use considerations combined with a more thorough risk assessment) that the
ultimate closure plan will require either re-excavation of .these soils or additional treatment of the soils in
situ. Therefore the necessary excavation of the soils as part of the interim action presents an opportunity
to either treat the soils and/or replace them in a way that greatly reduces their continuing threat to
groundwater and their long-term potential threat to public health. If future treatment is necessary, then
replacing the soils now would have the effect of making final remediation more expensive because of
C-3
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INTERIM ACTION RECORD OF DECISION WSRC-RP-93-1550, REV. 1
D-AREA OIL SEEPAGE BASIN JANUARY 16,1995
the potential need to re-excavate the soil for treatment or for the installation of a barrier beneath the soils
to protect groundwater.
The preferred option would return contaminated soils to the ground in an unlined trench. The option
also proposes that the most contaminated soils would be buried at the bottom of the trench where they
are closer to the water table and more likely to come in contact with groundwater (which testing shows
is already contaminated). Both facets of the re-burial are highly questionable. Because the interim
action is justified, and the excavation of contaminated soils is an unavoidable action, we think this
places an inescapable burden on SRS to show that the subsequent disposition of the contaminated soils
does not re-introduce a potential groundwater contamination source to the site. Indeed, because the
more contaminated soils would be placed closer to groundwater, the re-burial of the soils may make
matters worse than they were prior to excavation.
Response
The treatment and/or storage of the basin soils will be addressed under ERF's comment
#2.
From the standpoint of ex-situ remediation, the excavation of the soils, in most cases, is a
relatively small cost compared to the cost of the associated treatment technology. Since
the nature and extent of the contamination within the trenches and the DAOSB waste unit
is not fully characterized, treatment and/or storage of excavated soils may not be needed
and doing so may be very costly.
While placing soils back into the ground may appear questionable, SRS believes the
preferred alternative will minimize the potential for continued groundwater
contamination. SRS concedes that the IAPP may not be clear as to what specifically will
be removed and how the material will be dispositioned. The IAPP proposed removing
the drum contents, pumpable free product, discernible layers of sludge and other principal
threat source material. SRS considers other principal threat source material to be the
interval at the bottom of the trenches that is saturated with and contains free product.
SRS will excavate the two main trenches to their respective bottoms, to a maximum
depth of approximately 8 ft, and remove the bottom layer of basin soils seen to be
contaminated with free product. SRS will not remove all the stained soils. The removed
soils will be placed in B-25 boxes (special storage boxes), characterized for waste
acceptance criteria and dispositioned according to applicable state and federal regulations
through the SRS TSDF. The soils will be replaced into the excavation in a last-out-first-
in fashion such that the cleaner soils will be toward the surface. A comprehensive
remedial investigation will be conducted during the summer of 1995 which will include
characterization of the vadose zone, the saturated zone soils and groundwater. From this,
a risk assessment will then be conducted to determine the potential risk and help select a
final course of action.
SRS believes that by removing the principal threat material at this time, the impact to
groundwater will be minimized. Replacing the remaining potentially contaminated soils
back into the excavation would at most minimally impact the groundwater. After being
subjected to 20 years of groundwater fluctuations, it is unlikely that any contamination
remaining in the replaced soils would migrate or leach to the groundwater. Based on
limited soil sampling data, the majority of the mobile species of contaminants are not
present at elevated levels in the basin soils. It is believed that the majority of the mobile
species would be found in the free product and sludge layers and in the drums. It is
unlikely that by performing this interim action and placing the soil back into the basin in
a last-out-first-in fashion, SRS would be making matters worse than they were prior to
C-4
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INTERIM ACTION RECORD OF DECISION WSRC-RP-93-1550, REV. 1
P-AREA OIL SEEPAGE BASIN JANUARY 16,1995
excavation. Currently, the most contaminated soils, along with the free product and
sludges, are closest to the groundwater. By performing the proposed interim action and
placing the soils back in a last-out-first-in fashion, SRS would not be making matters
worse but greatly decreasing the potential for further groundwater contamination.
Comment
2?) Because the projected cost of treating the excavated soils and debris is the problem with Alternative
#3, ERF would like to see a more thorough assessment of the treatment/disposition options.
Specifically, there should be more consideration given to options that would involve on-site treatment of
the contaminated soils as opposed to transporting them to another site for incineration.
With respect to treatment options DOE's Office of Technology Development has, for example, initiated
the Supercritical Water Oxidation (SCWO) Program for the treatment of mixed and hazardous wastes.
in a February 1994 profile of the SCWO program OTD reported: "In contrast to incineration, SCWO
can easily be designed as a full containment process with no release to the atmosphere (and) can achieve
the high destruction efficiencies for hazardous waste such as polychlorinated biphenyls (PCBs) or
dioxins" both of which are present in D-Area soils at levels in excess of RCRA Subpart S action guides.
Other treatment options may also be available or under development that could substantially lower the
costs of treatment.
Even if lower cost and adequate treatment technologies are not immediately available, consideration
should be given to storing the soils in a readily retrievable form at least until a more thorough risk
assessment is completed as part of the RFI/RI process. This could be done at a fraction of the cost of
transporting and incinerating the soils. While it may preclude burial of the soils in the manner proposed
in Alternative #2, it would not necessarily preclude burial of the soils at another location at SRS if this is
compatible with RCRA and CERCLA regulations. It would also allow more time for the development
of treatment options.
If storing the soils is inappropriate for some reason, then another alternative which might be considered
is lining the basin before the soils are re-introduced. This would at least provide some additional
protection while a final remedial action is selected.
Finally, storage and treatment alternatives could be considered for the most contaminated soils as a less
expensive alternative than storing or treating all removed soils. While not fully protective of public
health and the environment, it might be preferable to the all or nothing approach outlined in the
proposed plan.
Response
Per the NCP and CERCLA guidance for an interim action, only a limited number of
alternatives need to be considered and in some cases perhaps only one. The alternatives
considered must be within the scope of the interim action and not conflict with any
potential final remedial action. The purpose of proceeding with this interim action is to
achieve the interim remedial action goals and objectives of removing the principal threat
source material (i.e. drum contents, free product and sludges) to minimize potential
releases from the trenches.
Many treatment options, including both on site and off site treatments, other than the
those included in the IAPP were reviewed. They included such treatments as in-situ
bioremediation, soil washing, lining and capping the trenches, debris washing and super
critical extraction/liquid phase oxidation to name a few. Most of the options were
C-5
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INTERIM ACTION RECORD OF DECISION WSRC-RP-93-1550, REV. 1
D -AREA OIL SEEPAGE BASIN JANUARY 16,1995
rejected, on an interim basis, due to inconsistency with the interim remedial action goals,
implementability problems, cost and insufficient data regarding the nature and extent of
contamination at the DAOSB. Also, one major factor for eliminating on site treatment
was time. It would take well over a year to construct and permit an on site treatment
facility and by the time it was operational, SRS would be close to completing the RI/FS
process for the unit. The simplest method for on site "treatment" is to send the waste
material to the on site TSDF for disposition. The disposition may include storage and or
disposal through one of the TSDF disposal contracts. As described in the IROD all
appropriate State and Federal regulations will be followed during the disposition of the
hazardous materials removed.
Since it is currently not known whether the soils are characteristically hazardous or
contain substances which require special treatment and handling practices, incineration
was selected as the primary treatment option. Incineration represents the best available
technology for many types of constituents, including PCBs, dioxins and furans.
It has become apparent that including the incineration alternative in the IAPP has clouded
the primary purpose for proposing and performing the interim action. Incinerating the
basin soils is more appropriate for a final action, and not the interim action. SRS agrees
that the all or nothing approach to dealing with the basin soils was not consistent with the
interim remedial action objectives. Therefore, alternative 3, excavation and incineration
of basin soils, will be removed from the IROD.
The issue of replacing the excavated soils was discussed internally and externally at
length. Options that included not replacing the contaminated soils and variations on
replacing the soils were reviewed. By not replacing the soils an open pit would remain.
Under this option, infiltration of rainwater could facilitate further groundwater
contamination or cause it to spread faster. If the excavation was to be refilled with clean
soils, there is the possibility that they would become contaminated due to the movement
of the groundwater. While lining the excavation would prevent the spread of
contamination into or out of the trench, it would allow the excavation to act as a pool for
the infiltrating water. Adding a cover or a cap would prevent the pooling effect. But
since the waste unit is not fully characterized, drilling through the liner and the cap would
be necessary thus compromising the integrity of the cap and liner. Furthermore, a liner
and cap may need to be removed for final remediation. Replacing the soils without a
liner or cap and excavating them a second time for final remediation, if needed, would be
cheaper.
SCWO is a promising innovative technology which has the ability to achieve organic
destruction efficiencies of over 99.99% (DOE, 1994). SCWO is being developed to treat
mixed waste streams at DOE facilities. At present, candidate mixed waste streams at
DOE facilities include: spent solvent, oils, and other organic or aqueous liquids, sewage
and organic laden sludges, spent carbon, solvent contaminated rags, and explosives and
energetics (DOE, 1994). The current design of the SCWO unit is as a continuous
process. The operating temperature and pressure of the unit (the critical point of water)
would be 374 degrees Celsius and approximately 3000 psi.
No cost information is available for the SCWO technology. But based on similar
technologies and the type of equipment required (high temperatures and pressures),
SCWO may prove to be an expensive technology.
Two other potential options for treating D-Area Oil Basin soils by SCWO is to: (1)
manage the soils in a batch process or (2) extract the contaminants in an aqueous stream
C-6
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INTERIM ACTION RECORD OF DECISION WSRC-RP-93-1550, REV. 1
P-AREA OIL SEEPAGE BASIN JANUARY 16,1995
and subsequently treat the aqueous stream by SCWO. Batch processing of wastes is in
the early stages of research and development. Extraction techniques have been
established for organic contaminants and some full-scale extraction technologies are
available. However, activities in the SCWO are in the pilot plant construction and testing
phase. The testing milestone is expected to be completed by the end of 1995 (DOE,
1994). Full-scale operations for hazardous waste treatment has not been predicted.
Treatment of soils from the basin by SCWO could require years to initiate. SRS will
evaluate the SCWO technology and any other technologies suggested.
The ongoing RI/FS will fully evaluate an appropriate range of storage and treatment
options. SRS would appreciate any further input for consideration during the final
remedy selection.
C-7
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