PB98-964026
EPA541-R98-113
December 1998
EPA Superfund
Record of Decision:
Paducah Gaseous Diffusion Plant
(USDOE) OU 15
Paducah, KY
8/10/1998
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DOE/OR/06-1527&D2
Primary Document
Record of Decision for Remedial Action
at Solid Waste Management Unit 91 of Waste Area Group
27 at the Paducah Gaseous Diffusion Plant
Paducah, Kentucky
July 1998
Cleared for Public Release
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Department of Energy
Oak Ridge Operations
Paducah Site Office
P.O. Box 1410
Paducah. KY 42001
-i September 22, 1998
Mr. Robert H. Daniell, Director
(Division of Waste Management
Kentucky Department for Environmental Protection
14 Reilly Road, Frankfort Office Park
~| Frankfort, Kentucky 40601
Mr. Carl R Froede Jr., P. G.
J United States Environmental Protection Agency
-* Region IV
DOE Remedial Section
I Federal Facilities Branch
Waste Management Division
-, 61 Forsyth Street
J Atlanta, Georgia 30303
-i Dear Mr. Daniell and Mr. Froede:
RECORD OF DECISION FOR REMEDIAL ACTION AT SOLID WASTE
MANAGEMENT UNIT 91 OF WASTE AREA GROUPING 27 AT THE PADUCAH
J GASEOUS DIFFUSION PLANT, PADUCAH, KENTUCKY DOE/OR/06-1527&D2
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Enclosed for your information is the final Record of Decision (ROD) for Solid Waste
Management Unit 91 of Waste Area Grouping 27 at the Paducah Gaseous Diffusion Plant The
ROD was signed by the Department of Energy (DOE) July 8,1998, and by the United States
Environmental Protection Agency August 10,1998. The Kentucky Department for
Environmental Protection (KDEP) gave conditional approval of the Dl version of the ROD on
June 9, 1998, pending minor modification, which DOE incorporated. Based on conversations
with representatives of KDEP on September 21, 1998, the June 9,1998, letter serves as their
concurrence for the ROD.
If you have any questions or require additional information, please call Myrna E. Redfield at
(502)441-6815.
Sincerely,
Jimmie C. Hodges, Site Manager
Paducah Site Office
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Mr. Daniell and Mr. Froede 2 September 22 1998
1.
-i Enclosure
cc w/o enclosure:
1 R. H. Blumenfeld, CC- 1 0
I P. A. Gourieux, Bechtel Jacobs Company/Kevil
J. C. Massey, Bechtel Jacobs Company/Kevil
1 B. E. Phillips, JEG/Kevil
' R. C. Sleeman, EM-91
T. Taylor, UKFFOU/Frankfort
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CERTIFICATION
Document Identification: Record of Decision for Remedial Action at Solid Waste
Management Unit 91 of Waste Area Group 27 at the Paducah
Gaseous Diffusion Plant, Paducah, Kentucky (DOE/OR/06-
1527&D2 Primary Document)
I certify under penalty of law that this document and all attachments were prepared under my
direction or supervision in accordance with a system designed to assure that qualified personnel
properly gather and evaluate the information submitted. Based on my inquiry of the person or
persons directly responsible for gathering the information, the information submitted is to the
best of my knowledge and belief, true, accurate, and complete. I am aware that there are
significant penalties for submitting false information, including the possibility of fine and
imprisonment for knowing violations.
U.S. Department of Energy (DOE)
Owner and Operator
C.
JimmieC. Hodges, Paducah Site Manager Date Signed
I certify under penalty of law that this document and all attachments were prepared under my
direction or supervision in accordance with a system designed to assure that qualified personnel
properly gather and evaluate the information submitted. Based on my inquiry of the person or
persons directly responsible for gathering the information, the information submitted is to the
best of my knowledge and belief, true, accurate, and complete. I am aware that there are
significant penalties for submitting false information, including the possibility of fine and
imprisonment for knowing violations.
Bechtel Jacobs Company LLC
Co-Operator
Manager of Projects Date Signed
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I DOE/OR/06-1527&D2
Primary Document
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Record of Decision for Remedial Action
at Solid Waste Management Unit 91 of Waste Area Group 27
at the Paducah Gaseous Diffusion Plant,
Paducah, Kentucky
July 1998
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Prepared by
Jacobs EM Team
175 Freedom Blvd.
Kevil, Kentucky 42053
Prepared for the
U.S. Department of Energy
Office of Environmental Management
Environmental Management Activities at the
Paducah Gaseous Diffusion Plant
Paducah, Kentucky 42001
managed by
Bechtel Jacobs Company LLC
for the
U.S. Department of Energy
tinder contract DE-AC05-98OR22700
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PREFACE
This Record of Decision for Remedial Action at Solid Waste Management Unit 91 of Waste
Area Group 27 at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky, DOE/OR/06-
1527&D2, was prepared in accordance with requirements under the Comprehensive
Environmental Response, Compensation, and Liability Act, the Resource Conservation
and Recovery Act, and Kentucky Revised Statues Chapter 224, Subchapter 46. This
work was performed under Work Breakdown Structure 1.4.12.7.1.11.07.05 (Activity
Data Sheet 5311). This document follows the outline for records of decision contained in
the Federal Facility Agreement For The Paducah Gaseous Diffusion Plant, DOE/OR/07-
1707, and the Guidance on Preparing Superfund Decision Documents: The Proposed Plan,
The Record of Decision, Explanation of Significant Differences, The Record of Decision
Amendment, EPA/540/G-89/007. Publication of this document meets a primary
document deliverable milestone for the United States Department of Energy's (DOE's)
Remediation Management Group at the Paducah Gaseous Diffusion Plant This
document provides the record of information and rationale that the United States
Environmental Protection Agency, the Kentucky Department for Environmental
Protection, and the DOE utilized in the selection of a preferred remedial action, 'or
corrective measure, at Solid Waste Management Unit 91 of Waste Area Group 27.
Information provided in this document forms the basis for the development of the
remedial design report for this project.
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CONTENTS
PREFACE ii
TABLES v
FIGURES v
ACRONYMS AND ABBREVIATIONS vi
PART 1. DECLARATION
SITE NAME AND LOCATION
STATEMENT OF BASIS AND PURPOSE
ASSESSMENT OF THE SITE
DESCRIPTION OF SELECTED REMEDY
STATUTORY DETERMINATIONS
PART 2. DECISION SUMMARY
2.1 Site Name, Location, and Description 1
2.2 Site History and Enforcement Activities 1
2.3 Highlights of Community Participation :..4
2.4 Scope and Role of Operable Unit .-...4
2.5 Response Action and the Site Management Strategy 4
2.6 Summary of Site Characteristics 5
2.6.1 Hydrogeologic Characteristics of the
Paducah Gaseous Diffusion Plant Area .5
2.6.1.1 Regional surface-water hydrology 5
2.6.1.2 Regional geology 5
2.6.1.3 Regional ground-water hydrology 8
2.6.2 Hydrogeologic Characteristics of Solid Waste
Management Unit 91 9
2.6.2.1 Surface features and surface water at Solid Waste
Management Unit 91 9
2.6.2.2 Geology and hydrogeology of Solid Waste
Management Unit 91 9
2.6.3 Operable Unit Characteristics 12
2.6.4 Summary of Actions Taken to Date 13
2.6.5 Contaminant Characteristics 14
2.7 Summary of Site Risks 14
2.7.1 Human Health Risk Assessment 14
2.7.2 Ecological Risk Assessment 18
2.7.3 Conclusions of the Risk Assessment 19
2.7.4 Remedial Action Objectives 19
2.8 Description of Alternatives 19
2.8.1 Alternative 1 — No Action 19
2.8.2 Alternative 2 — In Situ Remediation (Lasagna™) 19
2.8.3 Alternatives — In Situ Enhanced Soil Mixing 21
2.9 Summary of the Comparative Analysis of Alternatives 21
2.9.1 Overall Protection of Human Health and the Environment....23
2.9.2 Compliance with Applicable or Relevant and Appropriate
Requirements 23
2.9.3 Long-term Effectiveness and Permanence 24
2.9.4 Reduction of Contaminant Toxicity, Mobility, or Volume
through Treatment 24
2.9.5 Short-term Effectiveness 24
2.9.6 Implementability 24
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2.9.7 Costs 24
2.9.8 State Acceptance 25
2.9.9 Community Acceptance 25
2.10 Selected Remedy 25
2.11 Statutory Determinations 26
2.11.1 Overall Protection of Human Health and the Environment. ...27
2.11.2 Applicable or Relevant and Appropriate Requirements 27
2.11.2.1 Chemical-specific applicable or relevant
and appropriate requirements 29
2.11.2.2 Location-specific applicable or relevant
and appropriate requirements 29
2.11.2.3 Action-specific applicable or relevant
and appropriate requirements 30
2.11.3 Cost Effectiveness 31
2.11.4 Utilization of Permanent Solutions and Alternative
Treatment Technologies 31
2.11.5 Preference for Treatment as a Principal Element 34
2.12 Documentation of Significant Changes 34
PART 3. RESPONSIVENESS SUMMARY
3.1 Responsiveness Summary Introduction „ 36
3.2 Community Preferences/Integration of Comments 36
APPENDIX Remedial Design Schedule for Solid Waste Management Unit 91
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TABLES
Table 2-1. Cost Estimates 25
Table 2-2. Applicable or Relevant and Appropriate Requirements and To Be
Considered Information for the Remedial Action (Lasagna™ with In Situ
Enhanced Soil Mixing Contingency) 32
FIGURES
Figure 2-1. Paducah Gaseous Diffusion Plant Vicinity Map 2
Figure 2-2. Location of Solid Waste Management Unit 91, Cylinder Drop Test Area....3
Figure 2-3. Surface-Water Features in the Vicinity of the Paducah Gaseous
Diffusion Plant 6
Figure 2-4. Schematic of Stratigraphic and Structural Relationships near the
Paducah Gaseous Diffusion Plant 7
Figure 2-5. Location of Cross Section A-A' 10
Figure 2-6. Cross Section A-A' at Solid Waste Management Unit 91, Cylinder
Drop Test Area 11
Figure 2-7. Approximate Extent of Soil Contamination and Area to be Remediated...15
Figure 2-8. Conceptual Site Model for Solid Waste Management Unit 91,
Cylinder Drop Test Site 16
Figure 2-9. Conceptual Schematic of Lasagne1* .20
Figure 2-10. In Situ Enhanced Soil Mixing Schematic 22
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ACRONYMS AND ABBREVIATIONS
The following list of acronyms and abbreviations is provided to assist in the review of
this document.
**Tc technetium-99
AGO Administrative Order by Consent
amsl above mean sea level
AR administrative record
ARAR applicable or relevant and appropriate requirement
AT123D Analytical Transient 1-, 2-, 3-Dimensional Model
BHHRA baseline human health risk assessment
bis below land surface
CERCLA Comprehensive Environmental Response, Compensation, and
Liability Act
C.F.R. Code of Federal Regulations
ds-l,2-DCE cis-l^-dichloroethene
on centimeter(s)
COC chemical of concern
CPF cancer potency factor
DNAPL dense nonaqueous phase liquid
DOE United States Department of Energy
ELCR excess lifetime cancer risk
EPA United States Environmental Protection Agency
Fed. Reg. Federal Register
FFA Federal Facility Agreement
ft foot (feet)
ft2 square foot (feet)
ft3 cubic foot (feet)
gal gallon(s)
HSWA Hazardous and Solid Waste Amendments
HU hydrogeologic unit
K.A.R. Kentucky Administrative Regulations
KDEP Kentucky Department for Environmental Protection
kg kilogram(s)
km kilometer(s)
KPDES Kentucky Pollutant Discharge Elimination System
1 liter(s)
m meter(s)
ms cubic meter(s)
MCL maximum contaminant level
xrg milligram(s)
NCP National Oil and Hazardous Substances Pollution Contingency Plan
NPL National Priorities List
O&M operation and maintenance
pCi picocurie(s)
PGDP Paducah Gaseous Diffusion Plant
ppm parts per million
POE point of exposure
PORTS Portsmouth Gaseous Diffusion Plant
PRAP proposed remedial action plan
PRP potentially responsible parties
RAO remedial action objective
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RCRA Resource Conservation and Recovery Act
RGA Regional Gravel Aquifer
ROD record of decision
SARA Superfund Amendments and Reauthorization Act
sec second(s)
SESOIL Seasonal Soil Compartment Model
SWMU solid waste management unit
TBC to be considered
TCE trichloroethene
TVA Tennessee Valley Authority
U.S.C.A. United States Code Annotated
UCRS Upper Continental Recharge System
USEC United States Enrichment Corporation
WAG waste area group
yds cubic yard(s)
yr year(s)
UFC uranium hexafluoride
jig microgram(s)
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products. This decision was based on several documents that comprise the AR for this
remedial action (e.g., the Preliminary Site Characterization/Baseline Risk Assessment/
Lasagna™ Technology Demonstration At Solid Waste Management Unit 91 of the Paducah
Gaseous Diffusion Plant, Paducah, Kentucky, KY/EM-128; the Feasibility Evaluation for
Trichloroethene-Contaminated Soil at Solid Waste Management Unit 91 at the Paducah
Gaseous Diffusion Plant, Paducah, Kentucky, DOE/OR/06-1557&D3; and the Proposed
Remedial Action Plan for Solid Waste Management Unit 91, Paducah Gaseous Diffusion Plant,
Paducah, Kentucky, DOE/OR/06-1499&D3). The AR includes detailed documentation
of the rationale for undertaking this remedial action at SWMU 91 of WAG 27. The
remedial action will be initiated pursuant to the PGDP's RCRA permits and this Record
of Decision (ROD). Values corresponding to the 1994 DOE Policy on the National
Environmental Policy Act also were incorporated in the documentation. The
Commonwealth of Kentucky concurs with the DOE and the EPA on the selected
remedial action. The scope of this action warrants the incorporation of the selected
remedy into the Hazardous Waste Permit KY8-890-008-982. This ROD will serve as the
primary document for the modification to the permit. This action will address the
chemical of concern (COC) in the soil [i.e., trichloroethene (TCE)] at SWMU 91 of WAG
27 and will serve as a step toward comprehensively addressing PGDP site problems. '
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from SWMU 91 of WAG 27
currently do not present an imminent and substantial danger to public health, welfare, or
me environment according to the Preliminary Site Characterization/Baseline Risk
Assessment/Lasagna™ Technology Demonstration at Solid Waste Management Unit 91 of the
Paducah Gaseous Diffusion Plant, Paducah, Kentucky, KY/EM-128. However, leachate and
transport computer modeling [e.g., Seasonal Soil Compartment Model (SESOIL)] as
presented in the Preliminary Site Characterization/Baseline Risk Assessment/Lasagna™
Technology Demonstration at Solid Waste Management Unit 91 of the Paducah Gaseous
Diffusion Plant, Paducah, Kentucky, KY/EM-128, indicates that the COC (TCE) present
in the soil could contaminate the Regional Gravel Aquifer at the point of exposure (POE)
at levels that could exceed the EPA maximum contaminant levels.
DESCRIPTION OF SELECTED REMEDY
The primary objective of this remedial action is to reduce the level of TCE-contaminated
soil thereby reducing the potential future concentrations in ground water that could pose
a threat to human health and the environment at the POE (i.e., the DOE property
boundary). The potential for migration of the contaminant from the soil to the off-site
aquifer is the concern associated with this SWMU. The soil at this SWMU contains TCE
with an average concentration of 84 mg/kg (ppm) that may migrate to the nearest POE
at unacceptable levels. Ground-water modeling indicates that reducing the concentration
of TCE in soil at SWMU 91 to less than 5.6 mg/kg will result in ground water that is less
than 5 Hg/1 at the PGDP's security fence. The selected remedial action reduces the
potential ground-water risk to human health and the environment by remediating the
TCE-contaminated soil to below 5.6 mg/kg.
Alternative 2 — In Situ Remediation (Lasagna™) is the selected remedy. The Lasagna™
technology was developed by an industrial consortium (Monsanto, DuPont, and General
Electric), in cooperation with the DOE Office of Environmental Management, Office of
Science and Technology (EM-50) and the EPA Office of Research and Development.
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The Lasagna™ technology was developed to remediate soils and ground water
contaminated with TCE and is especially suited to sites with low-permeability soils. The
process uses electroosmosis to move soil contaminants by flushing multiple pore
volumes of water through treatment zones where the TCE can be captured or chemically
altered to non-toxic products.
The success of the technology's initial demonstration (Phase I) that began January 3,
1995, and ran for 120 days at SWMU 91, led to a full scale Phase IIA field
demonstration that was conducted at SWMU 91 from August 1996 through July 1997.
The Phase HA demonstration was executed on an area of approximately 6 m x 9 m (20
ft x 30 ft) and approximately 14 m (45 ft) deep. The demonstration used a mixture of
kaolin clay and iron particles as the treatment zone medium. The treatment zone
material was installed using a hollow mandrel. Iron filings were mixed with wet kaolin
clay to form a slurry that was poured down the 14 m (45 ft) mandrel. As a treatment
medium, iron has been shown to reduce TCE chemically to non-toxic end products.
The components of Alternative 2 — In Situ Remediation (Lasagna™) include these.
• Electrodes energized by direct current that cause soluble contaminants
(i.e., TCE) to be transported into or through the treatment layers and heat the
soil. The contaminated water in the pore volumes will flow from the anode
through treatment zones toward me cathode.
• Treatment zones containing reagents that either can decompose the TCE to
non-toxic products or can adsorb the TCE contaminants for immobilization,
depending on the medium design.
• A water management system that recycles and returns the water that
accumulates at the cathode back to the anode for acid-base neutralization.
If SWMU 91 has not reached the regulatory approved risk assessment cleanup level (i.e.,
soil levels) of 5.6 mg/kg within two years, the operation may be continued until cleanup
levels are reached. However, if the technology is not successful, even after an extended
operating time, the DOE, in agreement with the EPA and the KDEP, may proceed to
remediate the unit with Alternative 3, In Situ Enhanced Soil Mixing.
The components of Alternative 3 — In Situ Enhanced Soil Mixing include the following:
• A crane or other mechanical mixing unit;
• An agent delivery system (e.g., hot air, steam, or hydrogen peroxide); and
• An off-gas collection /treatment system (e.g., activated carbon that will be
regenerated or stored onsite).
The EPA and the KDEP have participated in the development of this ROD, including
review and comment on the content of the document.
STATUTORY DETERMINATIONS
Both remedial technologies [In Situ Remediation (Lasagna™) and In Situ Enhanced Soil
Mixing] are protective of human health and the environment and comply with federal
and state applicable or relevant and appropriate requirements. The remedial actions
also are cost effective and follow the statutory mandate for permanent solutions and
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alternative treatment technologies to the maximum extent practicable. Additionally, they
meet the statutory preference for remedies that employ treatments that reduce toxicity,
mobility, or volume through treatment as a principal element. If unrestricted use and
unlimited exposure remain at the unit after the operational period, a five-year review
evaluating whether the remedy continues to provide adequate protection for human
health and the environment will be required.
Rodney R. Nelson
Assistant Manager for Environmental Management
United States Department of Energy
Date 7-
Date
Richard Green
•Acting. Director, Waste Management Division
United States Environmental Protection Agency, Region
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DECISION SUMMARY
2.1 Site Name, Location, and Description
The Paducah Gaseous Diffusion Plant (PGDP) is located in western Kentucky,
approximately 16 km (10 miles) west of Paducah and about 6 km (4 miles) south of the
Ohio River (Figure 2-1). This plant is an uranium enrichment facility owned by the
United States Department of Energy (DOE). The PGDP, which has been in operation
since 1952, supplies fuel for commercial reactors.
The Energy Policy Act of 1992 transferred operation of the DOE's uranium enrichment
facilities to the United States Enrichment Corporation (USEC). Effective July 1, 1993,
Martin Marietta Utility Services, Inc., (now Lockheed Martin Utility Services, Inc.)
contracted with the USEC to provide operation and maintenance (O&M) services. The
DOE continues to perform environmental restoration, decontamination and
decommissioning, and waste management activities at the PGDP under its
Environmental Management Program contracted to Bechtel Jacobs Company LLC.
Under the DOE's Environmental Management Program, cleanup activities currently are
being conducted at the PGDP to address contamination that resulted from past waste-
handling and disposal practices. These cleanup activities comply with the requirements
of the Commonwealth of Kentucky, the United States Environmental Protection Agency
(EPA), and the DOE.
This Record of Decision (ROD) addresses one of the solid waste management units
(SWMUs), the Cylinder Drop Test Area (SWMU 91), identified at the PGDP (Rgure
2-2). This SWMU is grouped in Waste Area Group (WAG) 27 as a potential source of
trichloroethene (TCE), a dense nonaqueous phase liquid (DNAPL) that has
contaminated the ground water of the Regional Gravel Aquifer (RGA). While the action
described in this ROD will remediate mis suspected source of ground-water
contamination, any risks to human health or the environment present at the site due to
contaminated ground water will be addressed as part of the ground-water integrator
operable unit evaluation (WAG 26).
2.2 Site History and Enforcement Activities
The Cylinder Drop Test Area (SWMU 91) encompasses approximately 0.7 hectares
(1.7 acres) and is located in the extreme west-central area of the plant on the southern
edge of the C-745-B Cylinder Yard (Figure 2-2). Drop tests were conducted at the PGDP
from late 1964 until early 1965 and in February 1979 to demonstrate the structural
integrity of the steel cylinders used to store and transport uranium hexafluoride (UF«).
Prior to structural testing, the cylinders went through thermal conditioning by immersing
them in a concrete pit containing dry ice and TCE. During the tests, a crane lifted the
cylinders to a specified height and dropped them onto a concrete and steel pad to
simulate worst-case transportation accidents.
In the first test period, a brine-ice bath was used to chill one cylinder prior to its drop
test. The 1979 test used a TCE- and dry-ice bath to chill one of the steel cylinders. The
concrete in-ground pit that held the TCE refrigerant for cylinder immersion leaked and
resulted in contamination of the surrounding shallow soil and ground water. Although
one corner of the pit was located, the exact location of the entire pit is unknown. The pit
is approximately 9 m (30 ft) from the drop pad.
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LEGEND
WMWe Management ATM
Paducah Ga«eou«DffiiiilonPtant(PGDP)
D«partm*nt ol Energy (DOE) RaswvaOon
Municipality
TvnnMM* Valtay Authority (TVA)
Paducah Qaseous Diffusion Plant
Paducah, Kentucky
BJMObt EM Twrn. 1(M
Figure 2-1. Paducah Gaseous Diffusion Plant Vicinity Map
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SWMU 91
CyfflfMtor Drop T««t AIM
SWMU Solid Waste
Management Unit
Paducah Gaseous
Diffusion Plant Fence
Appteanwto So*H (It)
BJacobs EM T*am. 1996
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Figure 2-2.. Location of Solid Waste Management Unit 91, Cylinder Drop Test Area
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The amount of TCE released at the drop test site can be estimated based on the size of
the cylinders. The cylinders are 3.7 m (12.2 ft) long and 1.2 m (4 ft) in diameter with a
15.2-cm (6-inch) stiffening ring/lifting lug offset on each side, yielding a minimum tank
width of 1.5 m (5 ft). The likely maximum quantity lost to the surrounding soil is
approximately 1,627.5 liters (430 gals) as presented in the Preliminary Site
Characterization/Baseline Risk Assessment/Lasagna™ Technology Demonstration at Solid
Waste Management Unit 91 of the Paducah Gaseous Diffusion Plant, Paducah, Kentucky,
KY/EM-128.
2.3 Highlights of Community Participation
A Notice of Availability was published in The Paducah Sun, a regional newspaper,
February 22,1998, announcing the beginning of the 45-day public review period for the
Proposed Remedial Action Plan for Waste Area Group 91 at the Paducah Gaseous Diffusion
Plant, Paducah, Kentucky, DOE/OR/06-1499&D3. The public comment period began
February 23, 1998, and ended April 8, 1998. Specific groups that received individual
copies of the Proposed Remedial Action Plan (PRAP) include the Natural Resource
Trustees and the Site Specific Advisory Board. There were no requests for a public
meeting or hearing; therefore, the tentatively scheduled public meeting and the hearing
on March 24,1997, were canceled.
2.4 Scope and Role of Operable Unit
Contamination levels mat could pose a threat to human health and the environment are
present in the soil at SWMU 91. The Lasagna™ field demonstration previously treated a
portion of the TCE contamination in the soil and shallow ground water at this SWMU.
Trichloroethene is present in the subsurface soil at this unit at concentrations indicative
of possible DNAPL pockets in the saturated soil. These DNAPL pockets could allow
long-term releases into the ground water. The shallow ground water beneath this unit
also contains elevated concentrations of dissolved TCE. This ground water is not used
for drinking water purposes, but it is hydraulically connected to the RGA and is the
pathway of concern.
The DOE proposes the in situ treatment of soil containing chemicals of concern (COCs)
mat exceed remediation levels at SWMU 91 using the Lasagna™ process. The purpose
of the selected response action is to destroy or break down TCE in situ reducing
contaminant levels below remediation levels. This response action will mitigate future
migration of dissolved TCE through ground water to the RGA and keep off-site releases
from mis unit below regulatory limits.
2.5 Response Action and the Site Management Strategy
The PGDP presents unusually complex problems in terms of hazardous waste
management and environmental releases. The DOE's proposed strategy is to divide the
site into operable units grouped by source areas and ground- and surface-water
integrator operable units. Discrete response actions will be selected and implemented for
each source area operable unit, as well as the integrator operable units that are impacted
by commingled releases from the source area operable units. Prioritization for
investigation and possible remedial action have been assigned to each of the integrator
operable units and source area operable units depending on their potential for
contributing to off-site contamination. As a suspected source of off-site ground-water
contamination, SWMU 91 is a high priority for remediation.
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The DOE already has begun to address the ground-water integrator operable units
through remedial actions on the Northwest and Northeast Plumes. By addressing this
future source of off-site ground-water contamination, the DOE is following the cleanup
strategy for the PGDP as outlined in the Site Management Plan, Paducah Gaseous Diffusion
Plant, Paducah, Kentucky, DOE/OR/07-1207&D3.
2.6 Summary of Site Characteristics
This section briefly describes the hydrogeology of the PGDP and discusses the local
hydrogeologic and contaminant characteristics of SWMU 91. It also presents an overview
of the actions conducted to date at the site.
2.6.1 Hydrogeologic Characteristics of the Faducah Gaseous Diffusion Plant Area
Unless otherwise noted, the information presented in this section is derived from the
Report of the Paducah Gaseous Diffusion Plant Groundwater Investigation Phase Iff, KY/EM-
150, and the Preliminary Site Characterization/Baseline Risk Assessment/Lasagna1*
Technology Demonstration at Solid Waste Management Unit 91 of the Paducah Gaseous
Diffusion Plant, Paducah, Kentucky, KY/EM-128.
2.6.1.1 Regional surface-water hydrology
The PGDP is located in the western portion of the Ohio River Basin (Figure 2-3). A local
drainage divide causes the plant's surface-water flow either to be to the east and
northeast toward Little Bayou Creek or to the west and northwest toward Bayou Creek.
Bayou Creek and Little Bayou Creek are perennial streams mat eventually discharge into
the Ohio River.
Bayou Creek flows generally northward along the western boundary of the plant from
I approximately 4 km (2.5 miles) south of the plant to the Ohio River. Little Bayou Creek
J originates within the West Kentucky Wildlife Management Area and flows northward
along the eastern boundary of the plant. Little Bayou Creek joins Bayou Creek in a
marsh located approximately 4.8 km (3 miles) north of the PGDP. Other surface-water
bodies located in the area surrounding the PGDP include the Ohio River, Metropolis
Lake, Crawford Lake, numerous small ponds, gravel pits, and settling basins.
At the PGDP, man-made drainage ditches receive storm water and effluent from the
plant These waters are routed through outfalls and eventually discharge into Bayou and
Little Bayou Creeks. The majority of the flow in these creeks can be attributed to effluent
water from the plant. The Kentucky Pollutant Discharge Elimination System (KPDES)
permitted outfalls have a combined average daily flow of 18.5 million liters per day
(4.88 million gallons per day) and are monitored by PGDP personnel.
2.6.1.2 Regional geology
The PGDP is located in the Jackson Purchase Region of western Kentucky, at the
northern tip of the Mississippi Embayment. The stratigraphic sequence at the PGDP
consists of a sequence of unconsolidated sediments unconformably overlying Paleozoic
limestone bedrock at a depth of approximately 104 m (340 ft). The sediments overlying
the bedrock consist of the following strata, in order of decreasing depth: the
Mississippian rubble zone, the McNairy Formation, the Porters Creek Clay, the Eocene
Sands, the continental deposits, and surficial loess and/or alluvium. Figure 2-4 presents
a schematic diagram illustrating the relationships between the geologic horizons present
at the PGDP.
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M M •—H II K
* Diffusion
Plant
SurtaotWatar
Roadways
SwamporManh
P«ducah Qacaous
OMuston PtarH Fanot
0 1500 9000 4500
^SHifE^
AppraidmaM So** (ft)
Modli»d tram CH2M HILL 1MO
DJteota EM TMID, 1996
Figure 2-3. Surface-Water Features in the Vicinity
of the Paducah Gaseous Diffusion Plant
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SOUTH
NORTH
UPFBI CONTMOfTAL MPOMTS
LOWER CONTM0ITM. DEPOSIT*
McNAIRY FORMATION
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Figure 2-4. Schematic of Stratigraphic and Structural Relationships near the Paducah Gaseous Diffusion Plant
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Potential Surface
Runoff Pathways
Dltch/Plpline
Wetland
100-Year Rood Plain
Monitoring Well
O Soil Boring
..170.— Topographic
Contour Internal «
*' C-745B Cylinder Yard
SWMU 91
UFg Cylinder Drop Test Area
''•*• '*^-:E^ 370 ...^•ri-^y
( Virginia Avenue
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Figure 2-5. Location of Cross Section A-A1
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A
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MW158 H003 MW159
TD110' TD78' TD70'
GL37V GL 371.6 esf GL 372'
0
TCE 8 u,p/k9
CERCLA Phase II Soil Data
TCE 8 u-9/kg
CERCLA Phase II Soil Data
-?n jTCE 41
CERCLA Phase II Soil Data
TCE
Ground Wat*r-S*mpte
120|ig/l
Water Sample
Aoproidrnaw Honxomtl Sett* (A)
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Ground-Water Sample
A'
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Concrete ELEVATION
Drop Test Pad n
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and overlying loess and has been divided into the following hydrogeologic units (HUs):
day to clayey silt (HU 1), sand and gravel (HU 2), and clay or silty clay (HU 3). A
pump test in the area measured the hydrologic properties of HU 2, a 3-m (10-ft) thick
layer of sand and gravel encountered at a depth of 6 to 9 m (20 to 30 ft) bis. Resulting
hydraulic conductivities values ranged from 3.70 x 10* to 3.97 x 10"5 cm/sec (1 x 10'2 to
1.12 x 10° ft/day) and storage coefficients ranged from 7.43 x 10'3 to 5.9 x 10'2. Water
level measurements taken in MW 160, which is screened in HU 2, indicate that the depth
to the water table is approximately 2 m (7 ft) bis at SWMU 91. The clay aquitard at the
base of the UCRS (HU 3) is approximately 4.6 m (15 ft) thick and occurs between
approximately 9 to 15 m (30 to 50 ft) bis. Flow within the UCRS is predominantly
downward into the uppermost aquifer, the RGA.
The RGA consists of a 4.6- to 6.1-m (15- to 20-ft) thick sand unit (HU 4) overlying 14 to
15 m (45 to 50 ft) of sandy, pebble- to cobble-sized chert gravel (HU 5) and sand
(upper McNairy Formation). Two monitoring wells have been completed in the RGA at
SWMU 91: MW 159, which is screened in the upper RGA at 19 to 21 m (63 to 68 ft) bis,
and MW 158, which is screened in the lower RGA at 31 to 32.9 m (102 to 108 ft) bis.
The depth to water in MW 158 was approximately 11 m (37 ft) bis [102 m (334 ft)
axnsl] in May 1994. Water levels in upper RGA MW 159 typically are slightly higher than
those measured in MW 158, indicating predominantly horizontal flow with a small
downward component of flow within the RGA. The top of the McNairy Formation is
encountered at 33 m (108 ft) bis in MW 158.
2.6.3 Operable Unit Characteristics
Results of the investigations conducted at SWMU 91 indicate that organic contaminants
are present in both soil and ground water at the unit The COC is TCE with maximum
levels of 1,523 mg/kg (ppm) and 943 mg/1 detected in subsurface soil and shallow
ground-water samples, respectively. The concentration of TCE detected in shallow
(UCRS) ground-water samples approaches the solubility limit for TCE
(1,100 mg/1), strongly suggesting the presence of DNAPL at the site. The concentrations
of TCE in the RGA ground-water samples at the unit are much lower, ranging from 8 to
120 ug/1, indicating that DNAPL likely is confined to the shallow (UCRS) soils at the
site. The areal extent of TCE-impacted soils at SWMU 91 has been estimated as
approximately 558 m2 (6,000 ft2), with TCE concentrations in this area averaging
84 mg/kg. The sampling results indicate that TCE has migrated below the water table
into the UCRS but has not fully penetrated through the HU 3 aquitard at the unit.
Residual contamination is present in the subsurface soils to an approximate depth of
14 m (45 ft) bis.
Other organic compounds have been detected, at low concentrations, in shallow (UCRS)
and deep (RGA) ground water at this unit. Those detected in UCRS ground-water
samples include the following: 1,1,1-trichloroethane; cis-l,2-dichloroethene (cis-1,2-
DCE); tetrachloroethylene; carbon tetrachloride; acetone; bromodichloromethane;
chloroform; and bis(2-ethylhexyl)phthalate. With the exception of the TCE degradation
product cis-l,2-DCE, these organic contaminants were detected only once and at
concentrations less than 20 UgA Cis-l,2-dichloroethene and two likely lab
contaminants, bis(2-ethylhexyl)phthalate and carbon disulfide, have been detected at
low levels in RGA ground-water samples at the unit. Several organic compounds also
were detected at low levels in soil samples at the site, including bis(2-
ethylhexyl)phthalate, fluoranthene, phenanthrene, pyrene, acetone, and memylene
chloride. However, the only organic compound detected at high levels in soil samples
from the unit is TCE.
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Six metals (aluminum, antimony, cadmium, chromium, iron, and manganese) have been
detected at elevated concentrations in unfiltered ground-water samples from the unit. Of
these metals, three (aluminum, iron, and manganese) were detected above regulatory
limits [maximum contaminant level (MCL) or secondary maximum contaminant levels]
in filtered UCRS ground-water samples. One, manganese, was detected above regulatory
limits in filtered RGA ground-water samples. Two metals, cobalt (15 mg/kg) and
aluminum (12,700 mg/kg), were detected at levels slightly exceeding the PGDP
background values (13.3 mg/kg and 12,000 mg/kg, respectively) in subsurface soil
samples collected from H003. This limited occurrence of metals in the ground water and
soils at the unit indicates that SWMU 91 likely is not a significant source of metals
contamination.
One radionuclide, technetium-99 (Tc), has been detected in UCRS and RGA ground-
water samples from SWMU 91. With the exception of one reported value of 336 pCi/1
from MW 160, the levels of **Tc detected at the unit generally are near the analytical
quantification limit of 25 pCi/1. The low activities detected in ground water and the
absence of "Tc from soil samples at the unit indicate its presence likely is related- to
more general plant activities rather than to specific past activities at this SWMU.
2.6.4 Summary of Actions Taken to Date
In 1993, SWMU 91 was selected as the site of an innovative technology demonstration.
The technology, known as Lasagna™, was developed by a consortium (Monsanto,
DuPont, and General Electric) with the support of the DOE and the EPA. The
Lasagna™ technology is an in situ technology that uses electrical voltage to move
shallow ground water and contaminants in fine-grained or clayey soils. Contaminants
are treated by passing contaminated ground water through in-ground treatment cells.
For Phase I of the technology demonstration, corrugated metal sheet piles were driven
into the subsurface at SWMU 91 to act as electrodes on the east and west sides of the
designated treatment area. The Phase I treatment area encompassed an area of 3.0 x
4.6 m (10 x 15 ft) and extended to a depth of 4.6 m (15 ft). The water treatment zones
consisted of activated carbon strips that adsorbed contaminants from the ground water,
including the target compounds (i.e., TCE and TCE degradation products). Sampling
and analytical results documenting the Phase I study are reported in the Preliminary Site
Characterization/Baseline Risk Assessment/Lasagna™ Technology Demonstration at Solid
Waste Management Unit 91 of the Paducah Gaseous Diffusion Plant, Paducah, Kentucky,
KY/EM-128. The Phase I demonstration was conducted over a four-month period
ending in May 1995 and resulted in a 98.4% reduction of TCE levels in soils within the
treatment area.
The success of the Phase I demonstration led to implementation, in August 1996, of a
large-scale demonstration (Phase HA). The Phase HA demonstration was carried out on
an area approximately 6.4 m x 9.1 m (21 x 30 ft) and approximately 14 m (45 ft) deep.
The ground-water treatment zones consisted of a mixture of clay and iron particles that
were expected to degrade TCE chemically in situ to nontoxic end products. Post-test soil
sampling conducted for the Phase HA demonstration indicated that cleanup
effectiveness of TCE ranged from 50% to 140%. As anticipated, TCE did not appear to
have been converted to higher concentrations of intermediate chlorinated compounds,
such as cis-l,2-DCE or vinyl chloride, but it was degraded to the end products ethane,
ethylene, and acetylene. The initial average TCE concentrations in soil were 18, 42, 52,
34, and 34 mg/kg at sampling locations 2A-01, 2A-02, 2A-03, 2A-04, and 2A-05,
respectively. After a treatment period of 11 months, the average concentrations
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had dropped to 0.87 (2A-01), 24 (2A-02), 0.16 (2A-03), 11 (2A-04), and 9.2
(2A-05) mg/kg. The cleanup objectives were achieved at locations 2A-01 and 2A-03,
and significant reductions occurred at the remaining locations (Figure 2-7).
2.6.5 Contaminant Characteristics
The conceptual site model (Figure 2-8) illustrates primary and secondary contaminated
media, transport pathways, exposure pathways, and receptors that may be affected by
releases. This model identifies contaminant leaching from soil to ground water as the
probable migration pathway from SWMU 91. The selected remedy presented in this
ROD is intended to address the source of contamination, thereby decreasing migration
from the unit and risks to potential receptors. It must be noted that potential receptors
listed in the conceptual site model currently are protected by the PGDP's water policy,
which offers an alternative water source to plant personnel and the surrounding
community. Potential impacts to human health and the environment-addressed-by the
selected remedy are discussed in Section 2.7.
2.7 Summary of Site Risks
The Preliminary Site Characterization/Baseline Risk Assessment/Lasagna™ Technology
Demonstration at Solid Waste Management Unit 91 of the Paducah Gaseous Diffusion Plant,
Paducah, Kentucky, KY/EM-128, contains the baseline human health risk assessment
(BHHRA) and an evaluation of potential ecological risks at the Cylinder Drop Test
Area. This assessment employed state and federal guidance to evaluate risks resulting
from exposure to ground water and soil contaminated with TCE and its breakdown
products at SWMU 91. Environmental transport of TCE to ground water below SWMU
91, to the PGDP security fence, to the DOE property boundary, and to the Ohio River
was considered in the baseline risk assessment using computer modeling programs:
RISKPRO™, SESOIL, and AT123D.
Specific information regarding the results of the human health and preliminary ecological
risk assessments are presented in the following sections. Those elements that are the
focus of the remedial action decision are discussed as appropriate.
2.7.1 Human Health Risk Assessment
Data from soil and ground-water samples collected during the SWMU 91 site
characterization were evaluated and used in the BHHRA. In addition to the data
evaluation, the BHHRA included an exposure assessment, a toxicity assessment, a risk
characterization, and a discussion of associated uncertainties.
The potential for human contact with contaminants is evaluated in the exposure
assessment. As illustrated in Figure 2-8, soil and ground water are the primary media
through which exposure may occur. The only receptor evaluated for potential soil
exposure in the BHHRA is a future excavation worker (assumed to be exposed to
contaminants in the top 3 m (10 ft) of soil 20 days/year for one year]. Receptors
evaluated for potential ground-water exposure in the BHHRA include: a future
industrial worker (assumed to come into direct contact with contaminated ground water
250 days/year for 25 years); and a rural resident [including both an adult (assumed to
come into direct contact with contaminated ground water 350 days/year for 34 years)
and a child (assumed to come into direct contact with contaminated ground water
350 days/year for 6 years)). Upon completion of the exposure assessment, doses for
each chemical of potential concern (COPC) are calculated for integration with toxicity
assessment information.
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Cylinder
Storage
Cylinder
Storage
Buried Culvert
Area of Soil Contamination S
(approximate)
(Mon.Mo.lW7)
BJ»oota EM TMIK.
Figure 2-7. Approximate Extent of Soil Contamination and Area to be Remediated
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Potential Primary Release Primary Secondary Release Secondary Exposure Potential
Sources Mechanism Transport/Exposure Mechanism Transport/Exposure Routes Receptor
Mechanism Mechanism
Spills
Infiltration/
percolation
Soil
Infiltration/
Percolation
DNAPL
Ground Water
Inhalation
Dermal
Contact
Ingestion
Inhalation
Dermal
Contact
Ingestion
1
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Excavation]
!
[Excavation
Figure 2-8. Conceptual Site Model for Solid Waste Management Unit 91, Cylinder Drop Test Site
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The toxicity assessment evaluates adverse effects to human health resulting from
exposure to all COPCs; however, the only COC at SWMU 91 is TCE. Consequently, the
toxicity assessment for this document focuses on TCE. During the development of the
Preliminary Site Characterization/Baseline Risk Assessment/Lasagna™ Technology
Demonstration at Solid Waste Management Unit 91 of the Paducah Gaseous Diffusion Plant,
Paducah, Kentucky, KY/EM-128, TCE was still classified as a B2 chemical, which may
cause cancer in humans through prolonged exposure. Since the development of this
document, the classification of TCE now is considered a Class C (possible carcinogen)
to B2 (probable) chemical, meaning there still is scientific uncertainty about whether TCE
will cause cancer in humans through prolonged exposure. To estimate excess lifetime
cancer risks (ELCRs) associated with prolonged exposure to potentially carcinogenic
materials, the EPA's Carcinogenic Assessment Group developed cancer potency factors
(CPFs) (also referred to as cancer slope factors). The Guidance on Preparing Superfund
Decision Documents: The Proposed Plan, The Record of Decision, Explanation of Significant
Differences, and The Record of Decision Amendment, EPA/540/G-89/007, outlines the use
of CPF as follows:
CPFs, which are expressed in units of (mg/kg-day)'1, are multiplied by the
estimated intake of a potential carcinogen, in mg/kg-day, to provide an upper-
bound estimate of the ELCR associated with exposure at that intake level. The
term "upper-bound" reflects the conservative estimate of the risks calculated
from the CPFs. This approach makes underestimation of the actual cancer risk
highly unlikely.
The cancer potency factors for TCE used in the BHHRA assume TCE is a B2 carcinogen;
they are as follows: for the oral pathway, 0.011 (mg/kg-day)"1; for the inhalation
pathway, 0.006 (mg/kg-day)"1; and for the dermal absorption pathway, 0.073
(mg/kg-day)"1. After assessing the toxicity of the contaminants, the results are combined
with the exposure assessment and used to develop the risk characterization.
The risk characterization indicates that currently there are no unacceptable risks to
human health at SWMU 91 and that risks to future workers are considered minimal.
This is partially due to the fact that the unit is covered with approximately 1.2 m (4 ft)
of soil and rock that eliminate the potential for direct contact with contaminated surface
soil. This eliminates surface soil as a pathway of concern for current and future workers.
The total cancer risk (i.e., ELCR) for exposure to subsurface soil by an excavation
worker is 1 x 10"7, which is well below Kentucky Department for Environmental
Protection's (KDEP's) allowable de minimus risk level of 1 x 10"*; therefore, the
subsurface soil is not a pathway of concern. To protect ground-water users, the DOE
provides an alternate water source to the PGDP and the surrounding community. Since
the alternate water source used by the plant will continue to be used in the future,
ground water is not a pathway of concern for current and future industrial workers.
Currently, the alternate water supply is used by all residents in the surrounding area
whose wells are contaminated; consequently, ground water can be eliminated as a
pathway of concern for current residents. However, transport modeling indicates that
the levels of TCE present in the soil at SWMU 91 will migrate to ground water below the
unit and eventually may reach the nearest point of exposure (POE) above the regulatory
level of 5 Hg/1 (i.e., the MCL), which may present a risk to future potential ground-water
users.
The maximum concentration of TCE predicted to reach the PGDP northern security
fence is 200 ug/1, which corresponds to a 1 x 10"5 ELCR. Consequently, a future
potential off-site ground-water user may come into direct contact with unacceptable
concentrations of TCE. To protect the future potential off-site ground-water users, the
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DOE will take an action that will lower the concentration of TCE in soil at the unit,
which will reduce the potential for contaminant migration to the nearest POE at
unacceptable levels. Ground-water modeling indicates that reducing the concentration of
TCE in soil at SWMU 91 to less than 5.6 mg/kg will result in a concentration in ground
water that is less than 5 ug/1 at the PGDP's security fence, which reduces the ELCR to a
future potential ground-water user by an order of magnitude to approximately 3 x 10"7,
thus protecting human health at the nearest POE, the DOE property boundary. Current
ground-water contamination below the unit (i.e., RGA) will be evaluated more
thoroughly, relative to cumulative impacts, in the WAG 27 investigation and the ground-
water integrator operable unit investigation.
Uncertainties that could affect the results of the risk assessment and the ground-water
modeling are detailed in Appendix G of the Preliminary Site Characterization/Baseline Risk
Assessment/Lasagne™Technology Demonstration at Solid Waste Management Unit 91 of the
Paducah Gaseous Diffusion Plant, Paducah, Kentucky, KY/EM-128, and are summarized as
follows:
• Trichloroethene and its breakdown products were singled out for much of the
sampling efforts at SWMU 91; therefore, contributions to total risk from
other contaminants that may be present are not considered;
• Frequencies of contact were used in the risk assessment that exceed current
rates and may exceed expected future rates, resulting in overestimated risks;
• Uncertainties in toxiciry values related to their derivation generally are
addressed by applying factors that lower the values resulting in
overestimated risks; and
• Uncertainties associated with the ground-water modeling performed;
specifically that the modeling did not consider attenuation of TCE, which
may result in lower concentrations at the nearest POE.
2.7.2 Ecological Risk Assessment
Potential ecological effects and whether SWMU 91 poses an immediate threat are
qualitatively evaluated in the preliminary ecological risk assessment. The ecological
evaluation concluded that currently there are no factors that pose a threat to ecological
receptors. In addition, no factors indicate the possibility of future exposure to ecological
receptors at SWMU 91, and it is likely mere will be no exposure along contaminant
migratory pathways. These conclusions are based primarily upon SWMU 91's location
within the facility boundaries inside the PGDP security fence. No critical habitats,
populations of, or potential habitats for federally listed, proposed, or candidate species
exist within the PGDP security fence. No waterfowl or fish are present in the ditches
surrounding the SWMU. The plant communities exist mostly in mowed grass and
channeled ditches. Therefore, assessing direct toxic effects on wildlife populations at
SWMU 91 is inappropriate due to the industrial nature and small scale of the unit.
Furthermore, the cumulative effects of contamination of small areas of terrestrial habitat
and contaminant migration from multiple source units to receiving areas (e.g., streams)
will be assessed in the PGDP baseline ecological risk assessment for the surface-water
integrator operable unit.
Based on the findings of the ecological risk evaluation, only the results of the BHHRA
were used to evaluate the need for action at SWMU 91 and to develop the remedial
action objective (RAO); however, implementing a technology to address human health
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concerns will improve conditions in the ecosystem by accelerating the natural
attenuation process.
2.7.3 Conclusions of the Risk Assessment
While the impacts of these uncertainties to the risk assessment results and ground-water
modeling vary, data conclusively shows that TCE is distributed throughout the soil
within SWMU 91. In addition, underlying ground water in the UCRS appears to have
been impacted as a result of TCE migration. In consideration of all available
information, TCE is identified as a human health COC, which is the primary emphasis
for remedial decisions at SWMU 91.
2.7.4 Remedial Action Objective
Results of the human health risk assessment indicate that the concentration of TCE in
the soil at SWMU 91 is not at levels that -are associated with unacceptable risk.
However, modeling indicates that TCE may migrate to the ground water and eventually
to the nearest POE at concentrations exceeding the MCL of 5 Jig/I. The RAO is intended
to prevent rural residents from exposure to the only COC, TCE. Thus, the RAO for
SWMU 91 is to mitigate migration of TCE beyond the SWMU boundary through the
ground water by the soil leaching pathway. The Lasagna™ technology demonstration
has been shown to meet effectively the RAO for SWMU 91 by treating TCE
contaminated soils present in SWMU 91 to less than 5.6 mg/kg. Remediating TCE levels
in soil below 5.6 mg/kg will reduce TCE concentrations below MCLs (less than 5 ug/1),
thereby protecting human health at the nearest POE in ground water.
2.8 Description of Alternatives
Twenty-one technologies were evaluated and screened in the Feasibility Evaluation for
Trichloroethene-Contaminated Soil at Solid Waste Management Unit 91 at the Paducah
Gaseous Diffusion Plant, Paducah, Kentucky, DOE/OR/06-1557&D3. Three alternatives
were retained for detailed evaluation. The following paragraphs present a description of
the three detailed alternatives evaluated for SWMU 91.
2.8.1 Alternative 1 — No Action
Pursuant to 40 C.F.R. § 300.430(e) of the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP), the DOE is required to consider a no action
alternative. This alternative serves as a baseline to which the other alternatives will be
compared. Under this alternative, no further action would be taken at SWMU 91.
Under this alternative, the DOE would take no action to address soil and future ground-
water contamination problems or to minimize further contaminant releases from SWMU
91. The alternative would not reduce future risk. No additional costs are associated
with this alternative.
2.8.2 Alternative 2 — In Situ Remediation (Lasagna™)
Alternative 2 consists of in situ soil treatment for TCE. The in-place soil treatment
proposed is a new, yet demonstrated, technology at the PGDP that is provided under
the trademark Lasagna™. The Lasagna™ process uses electroosmosis (electrical fields)
to drive pore volumes of water containing TCE to treatment zones that also are located
in the ground (Figure 2-9). The volume of soil proposed for treatment at SWMU 91 is
estimated to be 32 m (105 ft) long by 18 m (60 ft) wide by 14 m (45 ft) deep, which
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Note: Electro-Osmotic Flow is Reversed
Upon SwHcNng Electrical Polarity.
•Jacob* EM T**m. 1M6
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Figure 2-9. Conceptual Schematic of Lasagna™
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equates to approximately 7,645 m3 (270,000 ft3 or 10,000 yd3). The treatment zones
(approximately 20) are estimated to be 18 m (60 ft) long by 14 m (45 ft) deep and
approximately 5 cm (2 inches) thick. The media used for treatment may consist of a
variety of products such as iron, kaolin clay, and water with the specific treatment
medium being determined during design. Electrodes will be placed at the ends of the
area and most likely at evenly spaced intervals between treatment zones to supply the
electrical current for treatment.
2.8.3 Alternative 3 — In Situ Enhanced Soil Mixing
Alternative 3 consists of stripping volatile organics using a crane-mounted auger (Kgure
2-10). The diameter of the soil auger ranges from 0.9 to 3.6 m (3 to 12 ft). Steam, hot air,
or hydrogen peroxide is injected through the auger to assist in stripping volatile organics
(i.e., TCE) from the soils. Soil vapors, contaminated with volatile organic compounds,
are collected under a surface shroud and transported to an off-gas treatment system
(e.g., activated carbon that would be regenerated or stored onsite). Treatment zones are
overlapped to address the entire contaminated area. ;
This technology is particularly suited to shallow applications [i.e., effective at depths
down to 12 m (40 ft)] above the water table, but it can be used at greater depths [some
commercial vendors have successfully operated this process at depths to 305 m (100 ft)
with the smaller diameter augers)]. This technology appears to be applicable to all types
of soils (i.e., sandy, silty, or clayey). This technology may require an off-gas treatment
system if the expected contaminant concentrations exceed emission standards;
therefore, the cost presented in the following text includes off-gas treatment.
Application of this technology at the Portsmouth Gaseous Diffusion Plant (PORTS) site
indicated that removal efficiencies decreased as depths increased; however, none of the
depths conducted at PORTS exceeded the 7-m (22-ft) depth interval. Removal
efficiencies also increased with operation times.
2.9 Summary of the Comparative Analysis of Alternatives
This section provides the basis for determining which alternative does the following:
(1) meets the threshold criteria for overall protection of human health and the
environment, and complies with applicable or relevant and appropriate requirements
(ARARs); (2) provides the best balance between effectiveness and reduction of toxicity,
mobility, or volume through treatment, implementability, and cost; (3) satisfies both
state and community acceptance; and (4) is consistent with the Hazardous Waste
Permit
Nine criteria are required by the CERCLA for evaluating the expected performance of
remedial actions. The remedial alternatives have been evaluated based on the nine
criteria that are identified as follows.
(1) Overall protection of human health and the environment. This threshold
criterion requires that the remedial alternative adequately protects human
health and the environment, in both the short and long term. Protection
must be demonstrated by the elimination, reduction, or control of
unacceptable risks.
(2) Compliance with ARARs. This threshold criterion requires that the
alternatives be assessed to determine if they attain compliance with
ARARs of both state and federal law.
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Note: Treatment agents (e.g., hot air or steam) are delivered through the mixing
blade with emissions captured in the shroud covering the mixed region.
Sourer. MoOfied from Mutch and Ash. 1993
BJ*oab* EM T««m. ims
Figure 2-10. In Situ Enhanced Soil Mixing Schematic
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(3) Long-term effectiveness and permanence. This primary balancing criterion
focuses on the magnitude of residual risk and the adequacy and reliability
of the controls used to manage remaining waste (untreated waste and
. j treatment residuals) over the long term (i.e., after remedial objectives are
met). Remedial actions that provide the highest degree of long-term
-* effectiveness and permanence are those that leave little or no waste at the
1 site, make long-term maintenance and monitoring unnecessary, and
minimize the need for institutional controls.
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(4) Reduction of contaminant toxicity, mobility, or volume through treatment.
This primary balancing criterion is used to evaluate the degree to which
the alternative employs recycling or treatment to reduce the toxicity,
mobility, or volume of the contamination.
(5) Short-term effectiveness. This primary balancing criterion is used to
evaluate the effect of implementing the alternative relative to the potential
risks to the general public, potential threat to workers, potential
environmental impacts, and the time required for protection to be
achieved.
(6) Implementability. This primary balancing criterion is used to evaluate
potential difficulties associated with implementing the alternative. This
may include technical feasibility, administrative feasibility, and the
availability of services and materials.
(7) Cost. This primary balancing criterion is used to evaluate the estimated
costs of the alternatives. Expenditures include the capital cost, annual
O&M, and the combined total present value of capital and O&M costs.
(8) State acceptance. This modifying criterion requires consideration and
incorporation of any comments on the ROD from the Commonwealth of
Kentucky.
(9) Community Acceptance. This modifying criterion provides for
consideration of any formal comments from the community concerning
thePRAP.
2.9.1 Overall Protection of Human Health and the Environment
An alternative must meet this threshold criterion to be eligible for selection. Alternative 2
would meet this criterion because it remediates the contaminated soil and reduces the
future potential for contaminants to migrate to the aquifer and offsite. Alternative 3 also
meets this criterion because it remediates the contaminated soil and reduces the future
potential for contaminants to migrate to the aquifer. Alternative 1 does not meet this
criterion since it does not address the remediation of contaminants in the soil and the
potential of the contaminant to migrate to the ground water and potentially off site.
2.9.2 Compliance with Applicable or Relevant and Appropriate Requirements
An alternative must meet this threshold criterion to be eligible for selection. The chosen
remedial action will provide compliance with ARARs. Both Alternatives 2 and 3 would
meet ARARs. A detailed description of ARARs is presented in Section 2.11 of this
ROD. Alternative 1 would not comply with ARARs.
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2.9.3 Long-term Effectiveness and Permanence
Alternative 2 would reduce potential long-term impacts to the aquifer by treating the
contaminated soil (i.e., destroy TCE). However, untreated TCE in the soil may remain
and could require minor maintenance and some monitoring. The specific needs for
maintenance and monitoring, if any, will be determined after the operational period.
Also, Alternative 3 would reduce potential long-term impacts to the aquifer by treating
the contaminated soil. Untreated TCE soil contamination may remain that could require
minor maintenance and some monitoring. Reliability for Alternative 1 is not applicable,
since no remedial action is taken.
2.9.4 Reduction of Contaminant Toxicity, Mobility, or Volume through Treatment
Alternative 2 will reduce toxicity, mobility, and volume through the treatment of TCE-
contaminated soil. This alternative will be designed to treat the soil to an average level
below 5.6 mg/kg by the Lasagna™ process, which uses electroosmosis (electrical fields)
to drive pore volumes of water to treatment zones. The Lasagna™ technology-is
predicted to remediate the contaminated soil to cleanup levels within two years. If the
unit has not reached cleanup levels after approximately two years, the process may be
allowed to continue for an extended time. However, if the process is not successful at
achieving cleanup levels, DOE, in agreement with the EPA and KDEP, may use another
technology (e.g., Alternative 3). Alternative 3 will also reduce toxicity, mobility, and
volume through the treatment of TCE-contaminated soil. Alternative 3 would be
designed to treat the soil to an average level below 5.6 mg/kg by conducting in situ soil
mixing combined with vapor extraction (e.g., hot air injection) and off-gas
collection/treatment. Alternative 1 will not reduce toxicity, mobility or volume through
treatment.
2.9.5 Short-term Effectiveness
Short-term effectiveness is not applicable for Alternative 1. No negative impacts on the
community or environment are anticipated for Alternative 2 or Alternative 3. Risk to
workers by volatile emission will be controlled by engineering methods and is within
acceptable limits for Alternative 3.
2.9.6 Implementability
Alternative 1 would be technically and administratively feasible to implement since no
action is involved. Availability of services and materials is not applicable since
construction would not take place.
Alternative 2 would be technically and administratively feasible to implement.
Construction and operation of the technology on a smaller scale have been proved at
the PGDP.
Alternative 3 would be technically and administratively feasible to implement. Materials
and services are available and the technology has been demonstrated at other
DOE facilities.
. 2.9.7 Costs
-* Estimated present worth, escalated capital costs, and 30-year O&M costs for each
alternative are presented in Table 2-1. The total present worth cost and O&M costs for
I each alternative also are presented in the Table 2-1.
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Table 2-1. Cost Estimates
Criteria
Cost
Total escalated
capital cost
Total present
worth capital cost
Annual O&M cost
Present worth
O&M costs
Total present
worth cost
Alternative 1 -
No Action
$0
$0
$0
$0
$0
Alternative 2 - In Situ
Remediation
(Lasagna™)
$1,924,000
$1,849,000
$7,000
$99,000
$1,948,000
Alternative 3 - In Situ
Enhanced Soil Mixing
$2,879,000
$2,762,000
$7,000
$102,000 .-
$2,864,000
2.9.8 State Acceptance
This remedial action will be initiated pursuant to provisions of the PGDP's Kentucky
Hazardous Waste Maragement Permit KY8-890-008-982. The Preliminary Site
Characterization/Baseline Risk Assessment/Lasagne™ Technology Demonstration at Solid
Waste Management Unit 91 of the Paducah Gaseous Diffusion Plant, Paducah, Kentucky,
KY/EM-128, was issued to the KDEP and the EPA for review. The Feasibility Evaluation
for Trichloroethene-Contaminated Soil at Solid Waste Management Unit 91 at the Paducah
Gaseous Diffusion Plant, Paducah, Kentucky, DOE/OR/06-1557&D3 and the Proposed
Remedial Action Plan for Solid Waste Management Unit 91, Paducah Gaseous Diffusion Plant,
Paducah, Kentucky, DOE/OR/06-1499&D3 have been approved by the KDEP and EPA.
2.9.9 Community Acceptance
As previously discussed in Section 2.3 and later in the Responsiveness Summary, which
is Section 3 of this ROD, the public has been provided the opportunity to comment on
the selected remedial action. No member of the public stated opposition to the selected
remedial action or any other aspect of the proposed plan.
2.10 Selected Remedy
Based upon the evaluation of the alternatives utilizing the nine CERCLA criteria, the
remedy that best meets the threshold, balancing, and modifying criteria for the scope
and objectives of this remedial action is Alternative 2.
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' The selected remedy will, at a minimum, consist of the following elements.
"J • In situ soil treatment for TCE (Lasagna™).
• The Lasagna™ process uses electroosmosis (electrical fields) to drive pore
<« volumes of water containing TCE to treatment zones located in the ground.
• The volume of saturated soil proposed for treatment at SWMU 91 is
estimated to be 32 m (105 ft) long by 18 m (60 ft) wide by 14 m (45 ft) deep,
j which equates approximately to 7,645 m3 (270,000 ft3 or 10,000 yd3).
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• The treatment zones (approximately 20) will be nearly 18 m (60 ft) long by
14 m (45 ft) deep and approximately 5 cm (2 inches) thick.
• The media used for treatment may consist of products such as iron, kaolin
clay, and water with the exact composition being determined during design,
• Electrodes will be placed at the ends of the area to be remediated and, most
likely, at evenly spaced intervals between the treatment zone boundaries to
supply the electrical current needed for treatment.
The DOE will prepare a detailed design for this remedial action in accordance with the
requirements specified in the Declaration of this ROD. During remedial design and
remedial construction activities, some changes may be made.
This action is expected to provide overall protection of human health and the
environment It also can be implemented in compliance with ARARs. This action will
serve as a remedial action for the soil at SWMU 91 of WAG 27. Contaminant mobility
to the underlying aquifer will be reduced as a result of the treatment. This alternative
will provide short-term effectiveness and may be readily implemented. As shown in
Table 2-1, the total present worth estimated cost for Alternative 2 is $1,948,000.
The Lasagna1** process is an innovative technology. If the unit has not reached cleanup
levels within two years, the process may be allowed to continue operation until cleanup
is achieved. However, if the process is not successful at achieving cleanup levels, the
DOE may use another technology, Alternative 3 — In Situ Enhanced Soil Mixing, to
remediate the unit. This technology consists of the following elements:
• A crane or other mechanical mixing unit;
• An agent delivery system (e.g., hot air, steam, or hydrogen peroxide); and
• An off-gas collection/treatment system (e.g., activated carbon that will be
regenerated or stored onsite).
2.11 Statutory Determinations
This remedial action is protective of human health and the environment and complies
with both federal and state ARARs. This remedial action is cost-effective, and it follows
the statutory mandate for permanent solutions and alternative treatment technologies to
the maximum extent practicable. Additionally, this action meets the statutory preference
for remedies that employ treatments that reduce toxiciry, mobility, or volume as a
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' principal element. Since contaminants may remain at the unit, a five-year review
evaluating whether the remedy's cleanup levels provide adequate protection for human
health and the environment may be required.
2.11.1 Overall Protection of Human Health and the Environment
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The selected action contributes to protection of human health for PGDP employees and
the public through treatment, which will limit the potential for direct exposure and
mitigate migration of contaminants from the SWMU. The remedy provides effective
sampling and management of all residual wastes generated during implementation of the
action, if unlimited use and unrestricted exposure remain after remediation.
2.11.2 Applicable or Relevant and Appropriate Requirements
The United States Congress specified in CERCLA § 121 (42 U.S.C.A. § 9621) that
remedial actions for the cleanup of hazardous substances must comply with the
requirements, criteria, standards, or limitations under federal or more stringent state
environmental laws that are legally applicable or relevant and appropriate to the
hazardous substances or circumstances at a site. The EPA categorizes ARARs as being
either "applicable" or "relevant and appropriate" to a site. The terms and conditions
pertinent to these categories are discussed as follows.
3* Applicable requirements are "those cleanup standards, standards of control,
and other substantive requirements, criteria, or limitations promulgated under
federal environmental or state environmental or facility siting laws that
«. specifically address a hazardous substance, pollutant, contaminant, remedial
» action, location, or other circumstance found at a CERCLA site" (40 C.F.R. §
300.5).
1 • Relevant and appropriate requirements are "those cleanup standards, standards
J of control, and other substantive requirements, criteria, or limitations
promulgated under federal environmental or state environmental or facility
~l siting laws that, while not applicable to a hazardous substance, pollutant,
_J contaminant, remedial action, location, or other circumstance at a CERCLA
site, address problems or situations sufficiently similar to those encountered
at the CERCLA site that their use is well suited to the particular site"
(40 C.F.R. § 3005).
Requirements under federal or state law may be either applicable or relevant and
appropriate to CERCLA cleanup actions, but not both. If a requirement is not
applicable, then it must be both relevant and appropriate in order for it to be an ARAR.
In cases where both a federal and a state ARAR are available, or where two potential
ARARs address the same issue, the more stringent regulation must be selected. However,
in cases where the implementation of a federal environmental program has been
delegated by the EPA to a state, typically, the analogous state regulations would be
used as ARARs.
Other information that does not meet the definition of an ARAR may be necessary to
determine what is protective or may be useful in developing CERCLA remedies. In
addition, ARARs do not exist for every chemical or circumstance likely to be found at a
CERCLA site. Therefore, the EPA believes that it may be necessary, when determining
cleanup requirements or designing a remedy, to consult reliable information that would
not otherwise be considered a potential ARAR. Criteria or guidance developed by the
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EPA, other federal agencies, or states may assist in determining, for example, health-
based cleanup levels for a particular contaminant or the appropriate method for
conducting an action for which no ARARs exist. This other information is to be
considered (TBC) information and may be used when developing CERCLA remedies.
The TBC information generally falls within three categories: (1) health effects
information, (2) technical information on performing or evaluating investigations or
response actions, and (3) policy. A possible fourth category of TBC information is
proposed regulations, if the proposed regulation is non-controversial and likely to be
promulgated as drafted.
The EPA further categorizes ARARs based on whether they are specific to the
chemical(s) present at the site (chemical-specific), the remedial action being evaluated
(action-specific), or the location of the site (location-specific). Terms and conditions
relevant to this categorization include the following.
• Chemical-specific ARARs usually are "health- or risk-based numerical values
or methodologies which, when applied to site-specific conditions, result-in
the establishment of numerical values" [53 Fed. Reg. 51437 (December 21,
1988)]. These values establish the acceptable amount or concentration of a
chemical mat may remain in, or be discharged to, the ambient environment.
• Action-specific ARARs usually are "technology- or activity-based requirements
or limitations placed on actions taken with respect to hazardous wastes, or
requirements to conduct certain actions to address particular circumstances
at a site" [53 Fed. Reg. 51437 (December 21,1988)]. Selection of a particular
remedial action at a site will trigger action-specific ARARs that specify
appropriate technologies and performance standards.
• Location-specific ARARs "generally are restrictions placed upon the
concentration of hazardous substances or the conduct of activities solely
because they are in special locations" [53 Fed. Reg. 51437 (December 21,
1988)]. Some examples of special locations include floodplains, wetlands,
-i historic places, and sensitive ecosystems or habitats.
The EPA designated these categories to assist in the identification of ARARs; however,
they are not necessarily precise [53 Fed. Reg. 51437 (December 21,1988)]. Some ARARs
J may fit into more than one category, while others may not fit definitively into any one
-* category.
According to the preamble to the NCP at 53 Fed. Reg. 51443 (December 21, 1988),
potentially responsible parties (PRPs) conducting remedial actions, or portions of
remedial actions entirely onsite as denned in 40 C.F.R. § 300.5, must comply with the
substantive portions of ARARs, but not the procedural or administrative requirements.
Substantive requirements pertain directly to the actions or conditions at a site, while
administrative requirements (e.g., permit applications and procedural requirements)
facilitate remedial action implementation. Also, CERCLA § 121(d)(4) [42 U.S.C.A. §
9621(d)(4)] provides several ARAR waiver options that may be invoked, provided that
human health and the environment are protected. Moreover, under CERCLA § 121(e)
[42 U.S.C.A. § 9621(e)], PRPs are not required to obtain federal, state, or local permits
in order to conduct on-site response actions.
In the NCP at 40 C.F.R. § 300.150, the EPA has addressed the relationship of ARARs to
worker protection standards. The EPA states that CERCLA response actions must
comply with the worker protection standards and requirements of the Occupational
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Safety and Health Act of 1970 (29 U.S.C.A §§ 651 through 678) and analogous state
laws; however, the standards and requirements are not ARARs [55 Fed. Reg. 8680
(March 8, 1990)].
The DOE, in Order 5480.4, Environmental Safety and Health Standards, establishes
general requirements for environmental protection, safety, and health standards for all
DOE and contractor operations. The Order is an internal standard, and, consistent with
40 C.F.R. § 300.150, is not an ARAR. Nonetheless, DOE Order 5480.4 must be followed
during the design, construction, operation, modification (if any), and decommissioning
phases of the remedial action.
Lastly, while CERCLA requires that the RCRA and other environmental laws be
evaluated as ARARs [42 U.S.C.A. § 9621(d)(2)(A) and 40 C.F.R. § 300.420(f)(l)(i)(A)],
this in no way limits, takes away, or negates the KDEP's RCRA authority at the PGDP.
Chemical-, location-, and action-specific ARARs and TBC information that exist for
remedial action at SWMU 91 are described in the following sections. These ARARs
apply both to the preferred Lasagna™ technology and to the contingency remedy, In Situ
Enhanced Soil Mixing, unless otherwise noted.
2.11.2.1 Chemical-specific applicable or relevant and appropriate requirements
Ground-water contamination.
The Kentucky Administrative Regulations at 401 K.A.R. 8:250-420 may be relevant and
appropriate for contaminated ground water at SWMU 91. The MCLs defined in these
regulations are legally applicable to water "at the tap" but are not applicable to the
cleanup of ground water. However, they may be considered as relevant and appropriate
in situations where ground water may be used for drinking water. The MCL for TCE is
0.005 mg/1 (401 K.A.R. 8:420 § 3). This ARAR is relevant and appropriate to both the
preferred and contingency remedy. Either technology is expected to reduce the soil
contamination to a level that would no longer contribute to ground-water contamination.
2.11.2.2 Location-specific applicable or relevant and appropriate requirements
Wetlands and floodplains.
No adverse impacts to floodplains or wetlands in the vicinity of SWMU 91 are
anticipated. Consequently, although all ARARs discussed in this section are applicable,
those referring to floodplains and wetlands will be met by avoidance of the resource.
However, if impacts become apparent, due to construction or other plan modifications,
additional requirements (compliance with the substantive requirements of Nationwide
Permit (NWP) 38, 33 C.F.R. § 330) will need to be addressed and/or initiated during
the remedial design and/or remedial action phase to comply with the ARARs. The
requirements discussed in this section will apply to both remedial technologies.
Wetlands, and a small portion of the 100-year floodplain of Bayou Creek, have been
identified in a drainage ditch approximately 100 feet south of SWMU 91. Construction
activities must avoid or minimize adverse impacts to wetlands and act to preserve and
enhance their natural and beneficial values [Executive Order 11990; 40 C.F.R. §
6.302(a); 40 C.F.R. § 6, Appendix A; and 10 C.F.R. § 1022]. In addition, construction
activities must minimize potential harm to the 100-year floodplain (Executive Order
11988 and 10 C.F.R. § 1022).
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The DOE will avoid, to the extent practicable, the long- and short-term adverse impacts
to floodplains and wetlands [10 C.F.R. § 1022.3(a)]. The DOE will undertake a careful
evaluation of the potential effects of any DOE action taken in a floodplain [10 C.F.R. §
1022.3(c)J.
Construction in wetlands will be avoided unless there are no practicable alternatives [40
C.F.R. § 6.302(a)]. Degradation or destruction of wetlands will be avoided to the extent
possible [40 C.F.R. § 230.10 and 33 U.S.C. § 1344(b)(l)]. Considerations about
protection of wetlands will be incorporated into planning, regulating, and decision
making [10 C.F.R. § 1022.3(b)]. Any action involving the discharge of dredged or fill
material into wetlands will be avoided to the extent possible (13 U.S.C. § 1344, 40
C.F.R. § 230, and 33 C.F.R. §§ 320 to 330).
2.11.2.3 Action-specific applicable or relevant and appropriate requirements
Solid waste management unit cleanup.
The regulations that apply to the cleanup of SWMUs are applicable to Lasagne™ and In
Situ Enhanced Soil Mixing. These applicable regulations do not contain specific cleanup
standards, but instead they require corrective action measures that will result in the
protection of human health and the environment (40 C.F.R. § 264.101 and 401 K.A.R.
34.-060 § 12). Either technology would comply with this ARAR
Site preparation activities.
Although fugitive dust associated with the implementation of either remedial action
would be minimal, on-site construction activities may produce airborne pollutants. The
Kentucky Air Quality standards found in 401 K.A.R. 63:010 §§ 3-4 contain general
standards of performance governing fugitive dust emissions. The standards require the
use of water or chemicals, if possible, and /or placement of asphalt or concrete on roads
and material stockpiles to control dust [401 K.A.R. 63:010 § 3(l)(b)]. The standards
also require that visible dust generated from implementation of the remedial alternative
not be discharged beyond the property line of the PGDP [401 K.A.R. 63:010 § 3(2)].
Additionally, all open-bodied trucks that operate outside the property boundary and
that may emit materials that could become airborne must be covered [401 K.A.R. 63:010
§ 4(1)]. These requirements are applicable.
Toxic air emissions.
No TCE emissions are anticipated with the Lasagna™ technology. However, if the
contingency remedy, In Situ Enhanced Soil Mixing, is implemented, the potential exists
for TCE emissions to occur. The DOE must first determine if the regulations at 401
K.A.R. 63:022 apply by calculating the significant emission level for the specific toxic air
pollutant (as specified in Appendix B of 401 K.A.R. 63:022). If it is determined that the
toxic air regulations apply, normally, a permit would be required. However, because this
is a CERCLA action, only the substantive provisions must be followed. The regulation
specifies that no source is to exceed the allowable emission limit specified in Appendix
A of 401 K.A.R. 63:022. If the emission limit cannot be met, even after the application of
best available control technology, then best available control technology must be used
(401 K.A.R. 63:022 § 3). Appropriate measures would be taken, if the contingency
remedy were implemented, to comply with this ARAR.
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' Surface-water control for construction activities.
Storm-water discharges from construction activities onsite at the PGDP are regulated by
j the KPDES Permit (KY0004049) established pursuant to 401 K.A.R. 5:055. The PGDP's
KPDES Permit specifies that best management practices and sediment and erosion
-» controls be implemented at a site to control storm-water runoff. These requirements are
j applicable during the construction of either remedy identified in this ROD.
Hazardous waste determination.
During construction of the remedial action, either Lasagna™ or In Situ Enhanced Soil
Mixing, a minimal amount of soil will be generated. The soil must undergo a hazardous
-l waste determination pursuant to 40 C.F.R. § 262.11 and 401 K.A.R. 32:010 § 2. If the
j waste is determined to be hazardous, RCRA Subtitle C requirements would be
applicable (40 C.F.R. § 262.34, 401 K.A.R. 34:030 § 5). Any waste generated during
— implementation of the remedial action will be characterized appropriately.
*-* Radioactive waste determination.
I Any waste generated with the remedial action must be characterized with sufficient
accuracy to permit proper segregation, treatment, storage, and disposal [DOE Order
5820.2A, m.3.d(l)]. The DOE Order 5820.2A is TBC information to the disposition of
Jany radioactive waste associated with this action. Waste characterization data must be
recorded on a waste manifest and must include the following: the physical and chemical
characteristics of the waste; volume of the waste; weight of the waste; major
radionuclides and their concentrations; and packaging date, package weight, and
I external volume. Again, during the implementation of Lasagna™ or In Situ Enhanced
Soil Mixing, appropriate characterization will occur.
Table 2-2 lists the chemical-, location-, and action-specific ARARs for remedial action at
SWMU91.
-i 2.11.3 Cost Effectiveness
The preferred remedy provides overall effectiveness to remove and treat contaminants
and to reduce potential risk while being proportional to its cost. The preferred remedy
1 represents the least expensive remedial alternative that employs innovative treatment.
2.11.4 Utilization of Permanent Solutions and Alternative Treatment Technologies
The selected remedy (Lasagna™) meets the statutory requirement to utilize permanent
solutions and treatment technologies to the maximum extent practicable. The selected
remedy also satisfies the five primary balancing criteria. It provides long-term
effectiveness and permanence; it provides the greatest reduction of toxicity, mobility,
and volume through treatment; it provides short-term effectiveness; it is administratively
and technically feasible to implement; and it is the most cost-effective remedial
alternative evaluated.
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Table 2-2. Applicable or Relevant and Appropriate Requirements and To Be Considered Information for the Remedial Action
(Lasagna™ with In Situ Enhanced Soil Mixing Contingency)
Regulatory Triggers
Requirements
Prerequisites
Federal Citation
K.A.R.
Citation
CHEMICAL-SPECIFIC
Protection of drinking
water
Treatment to MCLs: TCE 0.005 mg/1.
Contaminants that have leached
into potential sources of drinking
water — Relevant and
appropriate to ground-water
remediation, applicable at the
"tap."
40 C.F.R. §
141.60
401 K.A.R. 8:420 § 3
LOCATION-SPECIFIC
Protection of
wetlands
Protection of
floodplains
Avoid or minimize adverse impacts
to wetlands to preserve and enhance
their natural and beneficial values.
Avoid degradation or destruction of
wetlands to the extent possible.
Incorporate considerations about
protection of wetlands into
regulating and decision making.
Follow substantive requirements of
general Nationwide Permit
conditions.
Avoid siting or construction in any
100-year floodplains.
Any federal action that will
have an impact on wetlands
— Applicable if avoidance is not
achieved.
Any action involving discharge of
dredged or fill material into
wetlands — Applicable if
avoidance is not achieved.
Any federal action that will
have an impact on wetlands
— Applicable if avoidance is not
achieved.
Any federal action within a 100-
year floodplain — Applicable if
avoidance is not achieved.
10CF.R,§1022
and Executive
Order 11990
40CF.R.§
230.10 and 13
U.S.C. §
1022.3(b)
10 C.F.R. §
1022.3(b)and33
C.F.R. § 330
10 C.F.R. § 1022
and Executive
Order 11988
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Table 2-2, Applicable or Relevant and Appropriate Requirements and To Be Considered Information for the Remedial Action
(Lasagna™ with In Situ Enhanced Soil Mixing Contingency) (Continued)
Regulatory Triggers
Requirements
Prerequisite
Federal Citation
K.A.R.
Citation
ACTION-SPECIFIC
Site preparation and
construction
activities
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Reasonable precaution must be taken
to prevent particulate matter from
becoming airborne. Such precautions
may include the following:
• Use water or chemicals to
control dust from construction
activities and/or place
asphalt, oil, water, or
suitable chemicals on roads
and material stockpiles to
control dust;
• Ensure that no visible
fugitive dust is emitted
beyond the property line; and
• Ensure that all open-bodied
trucks are covered if any
materials in the truck could
become airborne.
Handling, processing,
construction, road-grading, and
land-clearing activities
— Applicable.
401 K.A.R. 63:010 § 3
401 K.A.R. 63:010 §
401 K.A.R. 63:010 § 3(2)
401 K.A.R. 63:010 § 4(1)
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2.11.5 Preference for Treatment as a Principal Element
The selected remedy meets the statutory preference for treatment as a principal element.
This is accomplished by the Lasagna™ technology that remediates soils by driving the
TCE-«>ntaminated pore volume water through treatment zones. The process uses
electroosmosis to move contaminants in the soil pore water into treatment zones where
the contaminants can be captured or decomposed.
2.12 Documentation of Significant Changes
The Proposed Remedial Action Plan for Solid Waste Management Unit 91 at the Paducah
Gaseous Diffusion Plant, Paducah, Kentucky, DOE/OR/06-1499&D3, was made available
for a 45-day public review and comment period that began February 23, 1998, and
ended on April 8,1998. No meeting was requested for the proposed plan nor were any
comments received from the public; therefore, the DOE has determined that no
significant changes to the remedy are necessary.
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RESPONSIVENESS SUMMARY
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RESPONSIVENESS SUMMARY
3.1 Responsiveness Summary Introduction
The responsiveness summary has been prepared to meet the requirements of sections
113(k)(2)(b)(iv) and 117(b) of the CERCLA, as amended by the Superfund
Amendments and Reauthorization Act (SARA) of 1986, that requires DOE as "lead
agency" to respond ". . . to each of the significant comments, criticisms, and new data
submitted in written or oral presentations" on the SWMU 91 of WAG 27 Proposed
Remedial Action Plan.
The DOE has gathered information on the types and extent of contamination found,
evaluated remedial measures, and recommended a remedial action that will reduce the
potential migration of contaminants from the soil to the aquifer (i.e., off-site ground
water to the FOE). As part of the remedial action process, a notice of availability
regarding the PRAP was published in The Paducah Sun, a major regional newspaper of
general circulation. The Proposed Remedial Action Plan for Solid Waste Management Unit. 91
at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky, DOE/OR/06-1499&D3, was
released to the general public February 23, 1998. This document was made available to
the public at the Environmental Information Center in the West Kentucky Technology
Park in Kevil, Kentucky, and at the Paducah Public Library. A 45-day public comment
period began February 23, 1998, and continued through April 8, 1998. The PRAP also
contained information that provided the opportunity for a public meeting to be held, if
requested. No request for the meeting was made by the public, so no meeting was held.
Specific groups that received individual copies of the PRAP included the Natural
Resource Trustees and the Site Specific Advisory Board.
Public participation in the CERCLA process is required by the SARA. Comments
received from the public are considered in the selection of the remedial action for the
site. The responsiveness summary serves two purposes: (1) to provide the DOE with
information about the community preferences and concerns regarding the remedial
alternatives, and (2) to show members of the community how their comments were
incorporated into the decision-making process- However, there were no public
comments.
3.2 Community Preferences/Integration of Comments
No comments, written or oral, were received from the public; therefore, this document
does not address public comments, except to the extent that it is assumed that the
proposed plan is satisfactory to the public.
36
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Remedial Design Schedule for
Solid Waste Management Unit 91
ID
1
2
3
4
S
6
7
8
9
10
11
12
13
14
15
16
17
10
19
20
21
Task Name | Duration | Start
PRAP/ROD 1700 2/23/98
Public Comment on PRAP 45d 2/23/98
End Public Comment Period Od 4/8/98
ROD Development 126d 4/8/98
EPA ROD Signature ; Od 8/11/98
Procurement 141d; 5/13/98
[
SOW, RFP, Proposal. Negotiate 140d > 5/13/98
Award Id 9/30/98
Remedial Design (RD) 262d 10/1/98
Draft Initial RD 30d 10/1/98
30% Onboard Review Od 10V30VB8
develop 60% package 70d 10/31/98
60% Onboard Review I Od 1/8/99
Develop 01 (90%) Package 70d 1/9/99
Issue 01 Remedial Design Od 3/19/99
EPA/KDEP Review of D1RD 33d 3/20V99
EPA/KDEP Issue Comments Od 4/21/99
Revise D1 Remedial Design 30d 4/22/99
Issue 02 Remedial Design ' Od 5/21/99 j
EPA/KDEP Rnal Review 29d 5/22/99!
CFC ' Od 6/19/99!
( Finish
8/11/98
4/B/98
i 4/8/98
| 8/11/98
8/11/98
9/30/M
:
9/29/98
9/30/98
6/19/99
10/30/98
10/30/98
" 1/8/99"
1/8/99
3/19/99
3/19/99
4/21/99
4/21/99
5/21/99
5/21/99
6/19/99
6/19/99
2nd Quarter
^^^^^
r^^
3rd Quarter
•*7I
J
«>4/8
^•s^^^-v:vs
•^^•••••IIIBBBM
4th Quarter 1st Quarter) 2nd Quarter) 3rd Quarter
spa
• 8/11
^KH^^BBp
I
•^••^•••^B^^ ^
• 10/30
^•^pspyva
• 1/8
hv.v.v.v.v.y.v.v.v.v.w.l
• 3/19
• 4/21
• 5/21
•
Protect: Lasagne
Schedule based on calendar days
Date: 4/29/98
Task
Progress
Milestone
3 Summary
Rolled Up Task
Rolled Up Progress
Rolled Up Milestone O
Page 1
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The distribution sheet that is included in this signed Record of Decision has become
obsolete since the signing of this Record of Decision. We have included this current revised
version by which we now distribute documents.
DISTRIBUTION
1
J
1
J
J
J
U.S. DEPARTMENT OF ENERGY
Myma Redfield
US. Department of Energy
P.O. Box 1410
Paducah, KY 42001
Nancy Cames, CC-10
(Letter only)
US. Department of Energy
Federal Office Building
200 Administration Road
Oak Ridge, TN 37830
Gary Hartman
(Letter only)
US. Department of Energy
Federal Office Building
200 Administration Road
Oak Ridge, TN 37830
Jimmie C Hodges (3 copies)
US. Department of Energy
P.O. Box 1410
Paducah, KY 42001
K. Kates, AD-424
(Letter only)
US. Department of Energy
Chirtn IBuilding
167 Mitchell Road
Oak Ridge, TN 37830
Robert L-Nace
(Letter only)
EM-423 Quince Orchard
US. Department of Energy
19901 Germantown Road
Germantown, MD 20874-1290
Robert C Sleeman, EW-91
(Letter only)
US. Department of Energy
Federal Office Building
200 Administration Road
Oak Ridge, TN 37830
Don Williams
EM-42/Cloverleaf Building
US. Department of Energy
19901 Germantown Road
Germantown, MD 20874-1290
U.S.gStVIRpNMENTAL
PROTEJ^i'l^N AGENCY
Carl R. Froede, Jr. (3 copies)
US. EPA, Region 4
61 Forsyth Street
Atlanta, GA 30303
JACOBS ENGINEERING
GRblJP
Bruce E. Phillips
Jacobs Engineering Group Inc.
175 Freedom Boulevard
Kevil, KY 42053
SYSTEMATIC MANAGEMENT
SYSTEMS
W. F. Redfield
US. Department of Energy Site Office
5600 Hobbs Road
West Paducah, KY 42086
KENTUCKY DEPARTMENT OF
FISH AND WILDLIFE
Wayne Davis
Environmental Section Chief
KY Department of Fish and Wildlife
Resources
f 1 Game Farm Road
Frankfort, KY 40601
BECHTEL 1ACOBS
COMPANYTTg
Patricia A. Gourieux
(Letter only)
Bechtel Jacobs Company LLC
761 Veterans Avenue
Kevil, KY 42053
Jimmy C Massey
(Letter only)
Bechtel Jacobs Company LLC
761 Veterans Avenue
Kevil, KY 42053
NATURAL RESOURCE
TRUSTEES
Alex Barber
Commissioner's Office
KY Dept for Environmental
Protection
14 Reilly Road
Frankfort Office Park
Frankfort, KY 40601
Abraham Loudermilk
Tennessee Valley Authority
400 W. Summit Hill Drive
Knoxville, TN 37902
Andrea B. Perkins
US. Department of Energy
Federal Office Building
200 Administration Road
Oak Ridge, TN 37830
Allen Robison
US. Department of Interior
Fish and Wildlife Service
446 Neal Street
Cookville, TN 38501
STATE OF KENTUCKY
Robert H. Daniell, Director
Division of Waste Management
KY Dept for Environmental
Protection
14 Reilly Road
Frankfort Office Park
Frankfort, KY 40601
Steve Hampson
Cabinet for Human Resources
Radiation Control Laboratory
100 Sower Boulevard
Suite 108
Frankfort, KY 40601
Todd Mullins
KY Division of Waste Management
US. Department of Energy Ste Office
5600 Hobbs Road
West Paducah, KY 42086
Tuss Taylor (3 copies)
UK/KDEP
18 Reilly Road
Frankfort Office Park
Frankfort, KY 40601
Dr. John A. Volpe
Radiation Control Branch
Cabinet for Human Resources
275 East Main Street
Mail Stop HS2E-D
Frankfort, KY 40621
TVA
TecTWhitaker
(Letter only)
Plant Manager
Shawnee Fossil Plant
7900 Metropolis Lake Road
West Paducah, KY 42086
U.S. ENRICHMENT
CORPORATION
T. Michael Taimi
(Letter only)
US. Enrichment Corporation
2 Democracy Center
6903 Rockledge Drive
Bethesda, MD 20817
U.S. GEOLOGICAL SURVEY
TomMesko
US. Geological Survey
9818 Bluegrass Parkway
. Louisville, KY 40299-1906
WEST KY WILDLIFE
MANAGEMENT AREA
W. D. Hendricks
West Kentucky Wildlife
Management Area
Kentucky Department of Fish
and Wildlife
10535 Ogden Landing Road
Kevil, KY 42053
SITE SPECIFIC ADVISORY
BOARD
Site Specific Advisory Board
Information Age Park Resource Center
2000 McCracken Boulevard
Paducah, KY 42001
J
JEG.0197.27
-------
DISTRIBUTION
US. DEPARTMENT OF ENERGY
Nancy Games, CC-10
US. Department of Energy
FedetafOffice Building
200 Administration Road
Oak Ridge, TN 37830
Gary Hartman
US. Department of Energy
FederafOffice BuildingEM-923
200 Administration Road
Oak Ridge, TN 37830
Jimmie C. Hodges (3 copies)
US. Department of Energy
P.O. Box 1410
Paducah,KY 42001
K. Kates, AD-421
US. Department of Energy
Federal Office Building
200 Administration Road
Oak Ridge, TN 37830
R.P. Molenaar
US. Department of Energy
Maxima Building
107 Union Valley Road
Oak Ridge, TN 37830
Robert C Sleeman, EW-91
US. Department of Energy
Federal Office Building
200 Administration Road
Oak Ridge, TN 37830
Don Williams
EM-42/Cloverleaf Building
US. Department of Energy
19901 Germantown Road
Germantown, MD 20874-1290
EPA
OurlR- Fioede, Jr. (5 copies)
US. EPA, Region 4
61 Forsyth Street
Atlanta, GA 30303
JACOBS ENGINEERING TEAM
IRC
Bruce E. Phillips (2 copies)
Jacobs Engineering Group Inc.
175 Freedom Blvd.
Kevil, KY 42053
Don J. Wilkes (2 copies)
Jacobs Engineering Group Inc.
125 Broadway
Oak Ridge, TN 37830
SYSTEMATIC MANAGEMENT
SYSTEMS
W. F. Redfield
US. Department of Energy Site Office
5600 Hobbs Road
West Paducah, KY 42086
KENTUCKY DEPARTMENT OF
FISH AND WILDLIFE
Wayne Davis
Environmental Section Chief
KY Department of Fish and Wildlife
Resources
#1 Game Farm Road
Frankfort, KY 40601
BECHTEL JACOBS COMPANY
rce
Patricia A. Gourieux (3 copies)
Bechtel Jacobs Company LLC
761 Veterans Ave.
Kevil, KY 42053
Jimmy C. Massey
Bechtel Jacobs Company LLC
761 Veterans Ave.
Kevil, KY 42053
K. L. Holt (2 copies)
Bechtel Jacobs Company LLC
761 Veterans Ave.
Kevil, KY 42053
NATURAL RESOURCE
TRUSTEEJ
Alex Barber
Commissioner's Office
KY Dept for Environmental
Protection
14 Reilly Road
Frankfort Office Park
Frankfort, KY 40601
Abraham Loudermilk
Tennessee Valley Authority
400 W. Summit Hill Drive
Knoxville, TN 37902
Andrea B. Perkins
US. Department of Energy
Federal Office Building
200 Administration Road
Oak Ridge, TN 37830
Allen Rob ison
US. Department of Interior
Fish and Wildlife Service
446 Neal Street
Cookville, TN 38501
STATE OF KENTUCKY
Robert H. Daniell, Director
Division of Waste Management
KY Dept. for Environmental
Protection
14 Reilly Road
Frankfort Office Park
Frankfort, KY 40601
Steve Hampson
Cabinet for Human Resources
Radiation Control Laboratory
100 Sower Boulevard
Suite 108
Frankfort, KY 40601
Todd Mullins
KY Division of Waste Management
US. Department of Energy Site Office
5600 Hobbs Road
West Paducah, KY 42086
Tuss Taylor (4 copies)
UK/KDEP
18 Reilly Road
Frankfort Office Park
Frankfort, KY 40601
Dr. John A. Volpe
Radiation Control Branch
Cabinet for Human Resources
275 East Main Street
Mail Stop HS2E-D
Frankfort, KY 40621
TVA
Barry Walton
Office of General Council WT-10A
400 W. Summit Hill Drive '
Knoxville, TN 37902
Janet Watts
Manager of Environmental Affairs
5D Lookout Place
1101 Market Street
Chattanooga, TN 37402-2801
Ted Whitaker
Plant Manager
Shawnee Fossil Plant
7900 Metropolis Lake Road
West Paducah, KY 42086
U.S. ENRICHMENT
CORPORATION
T. Michael Taimi
US.EC.
2 Democracy Center
6903 Rockledge Drive
Bethesda, MD 20817
U.S. GEOLOGICAL SURVEY
TomMesEo
US. Geological Survey
9818 Bluegrass Parkway
Louisville, KY 40299-1906
WEST KY WILDLIFE
MANAGEMENT AREA
LeeBolrdy
West Kentucky Wildlife
Management Area
Kentucky Department of Fish
and Wildlife
10535 Ogden Landing Road
Kevil, KY 42053
JEG.OJ97.27/DlfcD2
6/26/98
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