United States Office of
Environmental Protection Emergency and
Agency Remedial Response
£EPA Superfund
Record of Decision:
EPA/ROD/R04-93/165
July 1993
USDOE Paducah Gas
Diffusion Plant, KY
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._-~_._~~------- -.-.
50272-101
REPORT DOCUMENTATION ,1. REP()RTNO. .
PAGE EPA!ROD/R04-93/165
4. TItle and Subthle
SUPERFUND RECORD OF DECISION
USDOE Paducah Gas Diffusion Plant, KY
First Remedial Action
7. Aulhor(8)
2.
3. Reclplenrs ACC88810n No.
s.
Report Data
07/22/93
6.
I.
Performing Organization Ripi. No.
9.
Performing Organization Name Ind Addl'8ll8
10 Project TaskIWork Unh No.
11. Contnlcl(C) or Grant(G) No.
(C)
~
12. Sp0n80rlng Organization Nama and Add.....
U.S. Environmental Protection
401 M Street, S.W.
Washington, D.C. 20460
13. Typl ot Repcin & Parlod Covlf8d
Agency
800/800
14.
1 S. Supplementary Not..
PB94-964018
16. Abstract (Umh: 200 words)
The USDOE Paducah Gas Diffusion Plant is an active Uranium Enrichment facility in
McCracken County, Kentucky, three miles south of the ohio River. Land use in the area
is predominantly industrial. From 1952 to present, the USDOE Paducah Gaseous Diffusion
Plant (PGDP) has operated a uranium enrichment facility, which supplies fuel for
commercial reactors. The PGDP uses a gaseous diffusio~ process to provide a physical
separation process, which allows for enrichment of the uranium. TCE has been used
continuously at the site to degrease fabricated metal parts. Technetium (Tc99) was
introduced to PGDP as a by-product of the reprocessing of uranium. An evaluation of
the quantities, concentrations, and records related to Tc99 indicated that this
radionuclide probably was introduced to ground water from past handling or disposal of
TCE contaminated with Tc99 and scrap metal contaminated with Tc99. In 1988, VOCs and
radionuclides were detected in private wells north of the PGDP. Later in 1988, EPA
required DOE. to conduct an investigation to determine the nature and extent of
contamination. The site investigation demonstrated that improper past handling
practices and , disposal of waste material led to the contamination of ground water,
including DNAPLs, migrating to the northwest from PGDP. The contamination is spreading
toward the Ohio River in multiple plumes. Following the discovery of ground water
(See Attached Page)
17. Document Analysis .. Descriptors
Record of Decision - USDOE
First Remedial Action
Contaminated Medium: gw
Key Contaminants: DNAPLs,
Paducah Gas Diffusion Plant, KY
VOCs (TCE), radioactive material
.
b.
Id8nt1f1arslOp8~nd8d Tarms
c.. COSATt FlaldIGroup
11. Avallabllhy Statemlnt
19. Security CIa8a (ThIs Report)
None
20. S8c:urhy Clu. (This Page)
None
21. No.otPsges
52
22. Prici
(Saa ANS\0Z3I1.1I)
SetlIn8trucII- on R..,-
OPTIONAL FORM 272 (~77)
(Fonnerly NTI$.3S)
Department of Comm8tc8
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EPA/ROD/R04-93/165
USDOE Paducah Gas Diffusion Plant, KY
First Remedial Action
Abstract (Continued)
contamination, DOE began providing an alternative water supply to' those residences with
contaminated ground water. This ROD addresses interim remediation of the ground water in
the northwest plume and will control the ongoing migration of contaminants in the
northwest plume. Future RODs will provide a final remedy for the ground water
contamination and for other onsite media. The primary contaminants of concern affecting
the ground water are DNAPLs; VOCs, including TCE; and radioactive materials.
SELECTED REMEDIAL ACTION:
The selected remedial action for this site includes extracting and containing DNAPL-
contaminated ground water; treating the ground water onsite using ion exchange, followed
by air stripping with onsite discharge of the treated water to a State permitted outfall;
filtering offgas emissions; and implementing a treatability study to evaluate the use of
iron filings as an innovative technology and an alternative to pumping and treatment in
the final remedial action. The estimated present worth cost for this remedial action is
$15,188,190, which includes an estimated annual O&M cost of $1,719,236.
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific ground water interim cleanup goals are based on SDWA MCLs, and include
TCE 5 ug/l.
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--~._. --~ - - .._~ --'-~----'-_._--~ .-
DOElORl06-1143&D4
Record of Decision for Interim Remedial Action
of the Northwest Plume at the
Paducah Gaseous Diffusion Plant,
Paducah, Kentucky
, July 1993
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DOElORl06-1143&D4
Record of Decision for Interim Remedial Action
of the Northwest Plume at the
Paducah Gaseous Diffusion Plant,
Paducah, Kentucky
July 1993
Prepared by
Science Applications International Corporation
DE-AC05-910R21950
P.O. Box 9 . Kevil, Kentuky 42053
Prepared for
U.S. Department of Energy
Enrichment Restoration Division
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CONTENTS
NOT A TI ONS .......... ","'"'''' ........... ........... ...... ....... ...................... ................... "'"'''''''' ..... ;........ v i
Part 1.
Part 2
Declaration for the Record of Decision
Interim Remedial Action of the Northwest Plume
State Name and Loaction
State of Basis and Purpose
Assessment of the Site
Description of Selected Remedy
Declaration
Decision Summary....... .... '''' ....................... ..... .............. ........ .................................. 1
21 Site Name, Location, and Description [[[ 2
22 Site History and Enforcement Activities[[[2
23 Highlights of Community Participation [[[ 7
24 Scope and Role of Operable Unit or Response Action........................... 8
Previous, Response Action Associated with this
Response Action........... ....... ..,.... .......... ................... ........... .............. .............. 8
This Response Action and the Site Management Strategy ...................9
Future Response Actions Associated with this Response Action..... 10
2S Integrator Operable Unit Characteristics ................................................. 11
Hydrogeologic Characteristics. ........... ........... ......;.... ......... ........ ............. ..... 11
Contaminant Characteristics. "'"'''' ...... ...... '''''''''''''''''''''''''''''' .................. 14
26 Summary of Site Risks [[['................. 14
27 Description of Alternatives [[[ 15
Alternative 1 - No Action[[[ 15
Alternative 2 - Extraction and Treatment, and Innovative
Technology Treatability Study...................................... 16
28 Summary of the Comparative Analysis '
of the Interim Alternative[[[~............. 17
Overall Protection of Human Health and the Environment............. 18
Compliance with ARARs ..... ....................................... ...................... ......... 19
Long-term Effectiveness and Permanence.............................................. 19
Reduction of Toxicity, Mobility, or Volume Through Treatment.... 19
Short-term Effectiveness........................... ............................... ................... 25
Imp lementabili ty ... ......... "'"'''''''''''''''''' [[[ 25
CO!!t ..... ....... .................. ......... ................ [[[' 25
State Approval....... ....... ................... ........................ "",,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 27
Community Acceptance ........ ...... .................... ......................... ..,................ 27
29 Selected Remedy;....... .................. ......... ............................................... ......... 27
210 Statutory Determinations. ...................... "'''''''''''''''''''''''''''''''''' ....... ......... 32
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Part 3.
Construction Activities... .... """'" ""'''''''''' .~.... ....... ..... ...... ...,... ........... ....... 37
Disposal of Treated Media.. ....... """'............................"............................ 39
Cost Effectiveness......;......................... ........ """'"'''''''''''''' "'''''''''''''''''''''''' 39
Utilization of Permanent Solutions and Alternative Treatment
Technologies........... .................. .............. ............ .... ""'''''''' '"'''''''''''''''''''''''' 40
Preference for Treatment as a Principle Element.................................. 40
2.11 Documentation of Significant Changes ""'"'''''''''''''''''''''''''''''''''''''''''''' 40
RESPONSIVENESS SUMM AR Y .. ""'" .......... ....... ............... '"'''''''''''''''''''''''''''' 41
3.1 Responsiveness Summary Introduction ..............................................:.42
32 Summary and Response to Local Community Concerns ...................44
3.3 Comprehensive Response to Specific Legal and Technical
Comments.. ...... ",,,,, ............ '"'''''''' ..... '"'''' ...... ..... ""'" ",,,,,,, ....... """'''''''''''' 49
111
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Figure 1
Figure 2
Figure 3
Figure 4
FIGURES
Location Map - Paducah Gaseous Diffusion Plant.......................................3
Current Land Ownership Map - Paducah Gaseous Diffusion Plant....... 4
Well Field Location Map [[[ ......... .... ..... ...6
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Table 1
Table 2
Table 3
Table 4
TABLES
Applicable or relevant and appropriate requirements (ARARs) and
guidance for the hydraulic containment of off-site ground water ........ 20
Cost Breakdown...... ...... ....... ....... ...................... "",,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ...... ....... 26
Estimated Cost of Hydraulic Containment Remedy................................ 30
Chemical-specific federal and state regulations for protection of ground
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NOTATIONS
The following list of acronyms, and abbreviations (including units of measure) are
provided to assist in the review of this document. Acronyms used in tables only are
defined in those respective tables. .
ACO
AEA
ALARA
ARARs
BAT
BETX
CERCLA
CWA
OCGs
DNAPL
OOE
001
DOT
~
EDE
Energy Systems
EPA
Fe
FS
HSWA
HSP
ICM
1M
IROD
KAR
KDEP
KDFW
KPDES
LDR
LLRWPA
MCL
MSL
NCP
NEPA
NPL
NRC
OSWER
PAH
PGDP
ACRONYMS AND ABBREVIATIONS
Administrative Order by Consent
Atomic Energy Act
as low as reasonably allowable
applicable or relevant and appropriate requirements
best available technology .
benze~e, ethlybenzene, toulene and xylene
Comprehensive Environmental Response, Compensation,
and Liability Act of 1980, as amended
Clean Water Act
drivied concentration guides
dense non-aqueous phase liquids
U.S. Department of Energy
Department of Interior
Department of Transportation
Data Quality Objective
effective dose equivalent
Martin Marietta Energy Systems Inc.
U.S. Environmental Protection Agency
iron
feasibility study
Hazardous and Solid Waste Amendments
Health and Safety Plan
Interim Corrective Measure
interim measures
. interim record of decision
Kentucky Administrative Record
Kentucky Department .lor Environmental Protection
Kentucky Division of Fish and Wildlife
Kentucky Pollutant Discharge Elimination System
land disposal restrictions
Low-Level Radioactive Waste Policy Act of 1985
Maximum Contaminant Level
Mean Sea Level
National Oil and Hazardous Substances Pollution
Contingency Plan .
National Environmental Policy Act of 1969
National Priorities List
Nuclear Regulatory Commission
Office of Solid Waste and Emergency Response
polycyclic aromatic hydrocarbon.
Paducah Gaseous Diffusion Plant
vi
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PHEA
Results of the Public Health and Ecological Assessment,
Phase II
proposed plan
Kentucky Radiation Control Branch
Resource Conservation and Recovery Act, as amended
regional gravel aquifer
reasonable maximum exposure
record of decision
Superfund Amendments and Reauthorization Act of 1986
Safe Drinking Water Act
silicon
Site Management Plan
to be considered
trichloroethylene
toxicity characteristic leaching procedure
pertechtenate ion
technetium-99
Total Dissolved Solids
Total Suspended Solids
Tennessee Valley Authority
upper continental recharge system
uranium hexafluoride
United States Geological Survey
ultraviolet
uranium-235
uranium-238
volatile organic compound
waste area groups
water quality criteria
West Kentucky Wildlife Management Area
fl'
RBC
RCRA
RGA
RME
ROD
SARA
SDWA
Si
SMP
TBC
TCE
TCLP
Tc04
~c
TDS
TSS
TVA
UCRS
UF6
USGS
UV
23SU
238U
VOC
WAGs
WQC
WKWMA
vii
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DECLARATION FOR THE RECORD OF DECISION
INTERIM REMEDIAL ACTION OF THE NORTHWEST PLUME
SITE NAME AND LOCATION
Northwest Plume
Paducah Gaseous Diffusion Plant
Paducah, Kentucky
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for the Northwest
Plume at the Paducah Gaseous Diffusion Plant (PGDP) in PaduqU\, Kentucky, chosen
in accordance with the Comprehensive Environmental Response, Compensation
and Liability Act of 1980 (CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA) and the National Oil and Hazardous Substance
Contingency Plan. This decision is based on the administrative record file for this
site.
This action was initiated pursuant to the Interim Measure provisions of the EP A and
Commonwealth of Kentucky Resource Conservation and Recovery Act (RCRA)
permits. The Commonwealth of Kentucky concurs' with the Federal Agencies on the
selected interim action, in accordance with the requirements of the Kentucky
Hazardous Waste permit.
ASSESSMENT OF THE SITE
Actual. or threatened releases of hazardous substances from this site, if not addressed
by implementing the response action selected in this record of decision (ROD), may
present an imminent and substantial endangennent to public health, welfare, or the
environment. .
DESCRIYTION OF SELECTED REMEDY
The primary objective of this interim remedial action is to initiate a first phase
remedial action, as an interim action to initiate control of the source and mitigate
the spread of contamination in the Northwest plume. This operable unit addresses a
portion of the contaminated ground water. Additional interim actions associated
with this integrator operable unit are being considered, as well as for other areas of
contaminated ground water. Other investigations are underway to address other
environmental media (e.g., surface water) and contaminated source areas.
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The major components of the interim action remedy include:
. The contaminated ground water will be extracted at two locations. The
first location, immediately north of the plant on the U.S. Department of
Energy (DOE) property, is intended to control the source. The second
ground water extraction location is offsite of the DOE reservation at the
northern tip of the most contaminated portion of the plume [greater than
1000 Ilg/I of trichloroethylene) TCE]. The contaminated ground water will
be pumped at a rate to reduce fw1her contribution to contamination
northwest of the plant without changing hydraulic gradients enough to
mobilize Dense Non-aqueous Phase Liquids (DNAPL) or significantly
affect other plumes. This pumping rate may be modified during
operation to optimize hydraulic containment by adjusting flow from the
extraction wells and to support subsequent actions.
.
The extracted ground water will be collected in a manifold and piped to
the treatment system, which will consist of two ion exchange units in
parallel followed by an air stripper with treatment for off gas emissions.
This technology will provide treatment to the contaminants of concern
(TCE and technetium-99). The target level for treatment of TCE is 5 ppb
and 900 pCi/1 for 99'fc.
. The amount of treated water discharged will be limited by the flow
capacity of the skid mounted treatment units. The treated water will be
discharged through Kentucky Pollution Discharge Elimination System
(KPDES) permitted outfall 001.
. This interim action also includes implementation of a treatability study to
evaluate an innovative technology. The innovative technology to be
studied involves the potential utilization of iron filings as a viable
alternative to pump and treat technology for ground water treatment.
. The remedy does not address source remediation, however; the remedy
will address continuing release from a DNAPL principal threat source
area.
DECLARATION
This interim action is protective of human health and the environment, complies
with federal and state applicable or relevant and appropriate requirements for this
limited-scope action, and is cost-effective. Although this interim action is not
intended to address fully the statutory mandate for permanence and treatment to the
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maximum extent practicable, this interim action does utilize treatment and thus is
in furtherance of that statutory mandate. Although partially addressed in this
remedy, the statutory preference for remedies that employ treatment that reduces
toxicity, mobility, or volume as a principal element will be addressed by both this
and the final response action. Subsequent actions are planned to address fully the
principal threats posed by the conditions at this site. This pilot plant will be
examined during the next two years to determine the e'ffectiveness of the remedial
action. Remedial activities associated with this remedy which continue beyond the
pilot plant phase will require a review be conducted to ensure that the remedy
continues to provide adequate protection of human health and the environment
within five years after commencement of the remedial action. This review is
necessary because this remedy will result in hazardous substances remaining on site'
above health-based levels. Because this remedy is an interim action ROD, review of
this site and of this remedy will be ongoing as DOE continues to develop final
remedial alternatives for the integrator operable unit.
u ,,~~
William D. Adams.
Assistant Manager for Environmental Restoration and Waste Management
U .5. Department of Energy
u.
I//~
Date
7- /r- f;J
'IA-
inistrator
ental Protection Agency, Region IV
Q~
Date 7 - 2.:2. - if ~
a ~gional A
1 ~.s. Enviro
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PART 2
DECISION SUMMARY
1
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DECISION SUMMARY
2.1 Site Name, Location, and Description
The Paducan Gaseous Diffusion Plant (PGDP) is an active Uranium EnriChment
facility owned and operated by the United States I?epartment of Energy (DOE) and co-
operated by Martin Marietta Energy Systems, Inc. (Energy Systems). PGDP is located
in the northwestern comer of Kentucky in western McCracken County, about 10
miles west of Paducah, Kentucky, and 3 miles south of the Ohio River (Figures 1 and
2).
The DOE in the role of "Lead Agency," as defined in the National Oil and Hazardous
Substances Pollution Contingency Plan (NCP) is conducting cleanup activities at
PGDP under its Environmental Restoration and Waste Management Program.
Pursuant to Executive Orc;ier No. 12,580,3 C.F.R. 193 (1987),53 Fed. Reg. 2923 Qanuary
29, 1987), the Lead Agency is required to assume the responsibility of ensuring that
sufficient action is taken to cleanup its sites so as to provide protection for human
health and the environment. These remedial activities are being conducted in
compliance with the requirements of the Commonwealth of Kentucky, the
Environmental Protection Agency (EP A) and DOE, as further described in the
following section. '
The PGDP is an active uranium enrichment facility which supplies fuel for
commercial reactors. Construction of the plant began in 1951 with operations
initiated by 1952. The PGDP uses gaseous diffusion to provide a physical separation
process which allows for enrichment of the uranium. Commercially produced
uranium hexafluoride (UF6) is composed of mostly uranium-238 (238U), with a small
percent of uranium-235 (235U). The gaseous diffusion process IS premised on the fact
that UF 6 with fissionable 23SU is slightly lighter than UF6 with 238U. Therefore, as the
UF 6 passes through the gaseous diffusion plant's cascade system, separation of the
23SU from the 238U takes place. This separation results in enriched uranium (slightly
higher percentage of 235U). The enriched uranium can then be transported to other
DOE facilities for further enrichment.
2.2 Site History and Enforcement Activities
In August 1988, volatile orgariic compounds (VOCs) and radionuclides were detected
in private wells north ,of the PGDP. The site investigation demonstrated that the
principle contaminants of concern in the offsite ground water are technetium-99
(99Tc), a radionuclide, and trichloroethylene (TCE), an organic solvent. The
2
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citY
~
IllINOIS
KENTUCKY
MISSOURI
Figure 1.
ILLINOIS
!
..
1
,.
t- ~ MilES---'
. I
DOE RESERVATION
ILLINOIS
KENTUCKY
..
..
~
..
~
J:
CI
%
WI
:i
Location Map - Paducah Gaseous Diffusion Plant
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~.~.
LEGEND
-- 'IVA PIOP£m'
~ PRriATE StCTDR DINERSHP
II LAND OWNED 1ft' ODE PGDP
2000
-
o
SCAL£ IN FEIT
5000
- LAND OIN£D 1ft' WEST ICY
- STATE IILDUFt UCUT. AREA '
III LAND OWNED 1ft' DOE UNDER
USE PERUIT TO ICDFWR
Figure 2. Current Land Ownership Map - Paducah Gaseous'
Diffusion Plant
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contamination is spreading generally northward towards the Ohio River in multiple
plumes. Past handling practices and disposal of waste material has lead to the
contamination of the ground water migrating to the northwest from PGDP. The
interpretation of the location of these plumes is presented in Figure 3. This figure is
for illustrative purposes only and should not be interpreted as a precise description
of the locations of the plumes. The outer boundary of the plume is approximately
three miles from the northern border of the facility security fence.
The contaminated area spans approximately 1.6 square miles. The contamination of
approximately three billion gallons of ground water may have occurred in the
Northwest Plume. Concentrations of the contaminants within the Northwest Plume
vary, with the higher concentrations within the centroid of the mass. The
concentrations also increase with proximity to the source areas (northwest comer of
PGDP).
Trichloroethylene is a nonflammable, highly volatile, colorless liquid used
extensively for degreasing fabricated metal parts. Trichloroethylene (fCE) has been
produced commercially in the United States since 1925, and used at PGDP
continuously since 1952. The use of this product has been steadily reduced by DOE
during the last several years by instituting waste minimization activities and using
alternative compounds.
Technetium was introduced to PGDP as a by-product of the reprocessing of uranium.
An evaluation of the quantities, concentrations, and all records related to 99'fc
indicates that this radionuclide was probably introduced to ground water from past
handling or disposal of TCE contaminated with 99Tc and scrap metal contaminated
with 99'fc.
In the fall of 1988, the EPA and DOE entered into an "Administrative Order by
Consent" (ACO) under Sections 104 and 106 of the Comprehensive Environmental
Response, Compensation, and Liability Act of 1980, as amended (CERCLA) to address
the offsite contamination. Pursuant to the ACO, PGDP conducted an investigation to
determine the nature and extent of contamination. Results of this effort were
published in a document entitled Results of the Site Investigation, Phase I
(Document #KY /ER-4, March 1991). A subsequent investigation sought to further
characterize the extent of contamination. Results of this investigation were
published in Draft Results of the Site Investigation, Phase II (Document
#KY /SUBI13B-97777CP-03/1991 /1, October 1991). A revised version of this
document was submitted to EPA and the Commonwealth of Kentucky in April 1992.
Alternatives for remediation were identified and evaluated and published in the
5
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-'\000
1
-------
document Draft Summary of Alternatives for Remediation of Offsite Contamination
at the PaduCIlh Gaseous Diffusion Plant (Document #OOE/OR-1013, December 1991).
On July 16, 1991, EP A and the Commonwealth of Kentucky jointly issued permits
under the Resource Conservation and Recovery Act (RCRA), as amended by the
Hazardous and Solid Waste Amendment of 1984 (HSW A). The EPA permit contains
only provisions of HSW A, while the Commonwealth of Kentucky permit contains
provisions to address hazardous waste management as well as provisions of HSW A.
The HSW A provisions require evaluation of hazardous constituents releases and
implementation of interim and final corrective measures to address such releases.
In May, 1992 the Draft Interim Corrective Measure Work Plan For Hydraulic
Containment and Ground Water Treatability Test (ICM) (Document #DOE-OR-1031)
was submitted to EP A and the Commonwealth, in accordance with the HSW A
provisions of the Commonwealth of Kentucky and EP A permits, describing an
option for initiating containment of the Northwest ground water plume. However,
information derived from ongoing ground water investigations indicated the need
to modify this work plan. The rationale for this modification included: collection of
additional information concerning the characteristics of the Northwest Plume, better
definition of the plume's boundaries, and to ensure consistency with the final action
which may include a passive treatment system.
A series of meetings between OOE, EP A and the Commonwealth of Kentucky, lead
to the agreement whereby DOE utilized the Interim Corrective Measure (ICM) Work
Plan to develop a Technical Memorandum for Hydraulic Containment of the
Northwest Plume, (SAIC 1993). The Technical Memorandum, in combination with
the Draft Summary of Alternatives for Remediation of Offsite Contamination
constitute DOE's equivalent of a Focused Feasibility Study for the Northwest Plume
interim remedial action. The interim alternatives were summarized and
transmitted for Public and Regulatory comment in the Proposed Plan for Interim
Remedial Action of the Northwest Plume, (SAIC 1993). The Technical
Memorandum will also serve as the ICM Work Plan, subject to review and approval
in accordance with the provisions of HSW A.
2.3 Highlights of Community Participation
On March 14, 1993, a notice of availability was published in The Paducah Sun, a
regional newspaper, regarding the Proposed Plan. This notice appeared in The
Paducah Sun from March 14th until the 21st of 1993. The Proposed Plan for Interim
Remedial Action of the Northwest Plume was released to the public on March 18,
1993. This document was made available at both the on-site and off-site
7
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. administrative records and at the Paducah Public Library. A public comment period
was held from March 18, 1993 through Apri116, 1993.
Specific groups which received individual copies. of the Proposed Plan included the
local PGDP Neighborhood Council, NatUral Resource Trustees, and the PGDP
Environmental Advisory Committee. Informal meetings were held with each group
on MarCh 18th and 22nd, respectively. At these meetings, DOE personnel briefed the
groups on the proposed action and solicited both written and verbal comments.
On March 29, 1993, an announcement of a public meeting scheduled for April 6th
appeared in The Paducah Sun. A display ad was placed in the newspaper on April 4,
1993 which also announced the public meeting and the availability of the document.
Information bulletins were mailed to 1,933 residents, 1,850 PGDP employees, and 133
local officials on March 31, 1993. Phone calls and/or visits were made to various
stakeholders, including neighbors and representatives of environmental groups, to
alert them of the public. comment period and briefly explain the Proposed Plan.
Proposed Plans and/or Technical Memorandums were mailed to those contacted. At
the April 6th public meeting, representatives of DOE, EP A and the Commonwealth
of Kentucky answered questions and addressed community concerns. Pursuant to a
request from the Tennessee Valley Authority (TV A) the comment period was
extended until April 23, 1993. This extension of time for public comment appeared in
The Paducah Sun on April 18, 1993. A response to the comments received during
the public participation period is included in the Responsiveness Summary, which
is part of this Record of' Decision. .
This decision document presents the selected interim remedial action for the
Northwest Plume at PGDP, chosen in accordance with CERCLA, as amended by
SARA, the EP A and Commonwealth of Kentucky permits issued under the RCRA,
as amended by HSW A, and to the extent practicable, the National Oil and Hazardous
Substances Pollution Contingency Plan (NCP). The decision for this interim action at
this site is based on the administrative record.
2.4 Scope and Role of Operable Unit or Response Action
Previous Response Action Associated with this Response Action
Following the initial discovery in 1988 of ground water contamination, DOE began
. providing an alternative water supply to those residences with contaminated ground
water. Provision of an alternate water supply was initiated to ensure immediate
protection of human health from potential adverse effects due to the consumption
and use of the contaminated ground water.
8
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This Response Action and the Site Management Strategy
Pursuant to EP A Office of Solid Waste and Emergency Waste Response (OSWER)
Directive 9355.3-D2, possible reasons for implementing an interim action include:
protection of human health and the environment from an imminent threat, or
institution of temporary measures to stabilize the site to prevent further migration
of the contaminant plume. The primary objective of this response action is to
stabilize the site by controlling the ongoing migration of contaminants in the
Northwest Plume.
A Site Management Plan (SMP) has been drafted which specifies the strategy for
investigating and remediating hazardous substance releases. The draft SMP was
submitted to the EP A and the Commonwealth of Kentucky for review. The proposed
strategy in the draft SMP is to divide the site into source areas and environmental
media which may be impacted by commingled hazardous substance releases from
source areas. Discrete response actions (Le., operable units) will be selected and
implemented to address the source areas (Le., source operable units) and the
environmental media (Le., integrator operable units) impacted by commingled
releases from source operable units. Prioritization in the draft SMP for investigation
and possible interim remedial actions have been assigned to each of the integrator
operable units and source operable units depending on their potential for
contributing to off-site contamination. Because integrator units serve as migration
pathways that transport contamination from source operable units to off-site
receptors, they receive the highest priority for undergoing initial evaluation and
interim actions.
Consistent with the site management strategy in the draft SMP, this action has been
prioritized to address the Northwest Plume of the ground water integrator operable
unit which includes offsite contamination that may continue to migrate and
contaminate clean aquifers and potentially expose additional offsite receptors. This
interim action (operable unit) comprises an incremental step towards
comprehensively addressing site problems. The primary objective of the interim
action is to stabilize the site by initiating control of the northwest contamination
plume. This interim remedial action addresses a portion of the ground water
integrator operable unit by mitigating the spread of the high concentration portion of
the Northwest Plume, decreasing the migration of contaminants from the
Northwest Plume source area, and providing mass removal of the contaminants in
the Northwest Plume. By implementation of interim actions, the ground water
integrator unit can be addressed in the most expedient manner consistent with the
program management principles of the NCP.
9
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The limited scale extraction and treatment systems in this ROD constitute the first
phase in remediation of the ground water contamination. This action can be
implemented rapidly while feasibility studies can be conducted for the remainder of
the integrator operable unit. This phased approach is consistent with EP A OSWER
Directive 9283.1~6 which sets EPA's policy for remediation of DNAPL contaminated
ground water. The directive advises that the plume should be contained early, that
initiation of early actions should take place as soon as possible after a problem is
identified for which an early action is appropriate, and early actions should be
coordinated with final remedies such that they are the first phase of . the overall
remedial action. The directive further advises that remedial actions for DNAPL
. contaminated ground water should be implemented in a phased approach so that.
information gathered from implementation. of the. early phase(s) can support
. selection of an appropriate final action.
This interim action also includes implementation of a treatability study to evaluate
an innovative technology that may serve to further reduce the long-term operating
costs associated with this remedial action. The innovative technology to be studied
is the utilization of iron filings as a viable alternative to pump and treat technology
for ground water treatment. Section 2.7 of this ROD provides greater detail regarding
the innovative technology and its treatability evaluation.
Future Response Actions Associated with this Response Action
The remedial action described by this ROD is not the final action for ground water or
for the Northwest Plume. Following issuance of the ROD for this extraction and
treatment system interim action, a feasibility study will be initiated to evaluate
additional remedial alternatives to improve the effectiveness of this limited scope
interim remedial action. The use of low permeability walls around the source and
pump areas of the dis.solved phase plume will be included in the feasibility study.
This study may lead to a Proposed Plan for a second interim action for the Northwest
Plume. .
Although a site investigation, public health and ecological assessment, and an
alternative evaluation was performed for the PGDP site, a final action cannot be
recommended until further characterization activities have been completed. Before
a final action can be recommended for the ground water integrator operable unit, a
baseline risk assessment must be completed for the ground water integrator operable
unit, including ecological risk, and the following data gaps need to be addressed, at a
minimum: more complete characterization of the Northeast Plume; the interaction
between the Regional Gravel Aquifer (RGA) and the deep aquifer; the interaction
10
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between the RGA and Ohio River; and the interaction of all source operable units
with the ground water integrator operable unit. Although additional data will be
needed before the selection of a final action, sufficient information is available to
support the interim remedial action presented in this document. This interim action
should not be inconsistent with nor preclude implementation of any currently
anticipated final remedy. Furthermore, data which is collected during this interim
action will be utilized to assist in evaluation of design and implementation of the
final action.
2.5 Integrator Operable Unit Characteristics
Hydrogeologic Otaracteristics
The subsurface underlying the PGDP consists of four primary, correlational
hydrogeologic units, the Upper Continental Recharge System (UCRS), the RGA, the
Porters Creek Clay, and the McNairy Formation. These correlations are based
primarily on the physical properties of the specific units. (See Figure 4).
The UCRS consists of clayey silt, with thin zones of sand and gravel appearing at
various elevations throughout the plant site. The sand and gravel are relatively
discontinuous laterally throughout the predominantly clayey silt of the upper
continental deposits. The flow direction is primarily vertical in this unit owing to
the large conductivity contrasts between it and the underlying RGA.
The RGA consists of sand and gravel facies of the lower continental deposits. This is
the dominant flow system for this region due to its relatively high hydraulic
conductivity and is the primary aquifer of interest in this interim remedial action.
The unit ranges in thickness from 10 to 40 feet with its main source of recharge as
infiltration from the upper continental deposits. The RGA is truncated by the Porters
Creek Clay. This "terrace" results in the restriction of flow and high hydraulic
gradient in this region of the plant. Toward the north end of the plant, near the Ohio
River, the gradient increases indicating discharge conditions. Existing regional maps
show that the RGA is thin or absent beneath the river implying that flow beneath
the river is unlikely. The normal pool elevation of the Ohio River as reported by
the United States Geological Survey (USGS) is 290 feet Mean Sea Level (MSL). This
level depicts discharge conditions at the boundary of the RGA with the Ohio River.
Consequently, the Ohio River is assumed to act as a sink, or hydraulic boundary to
the flow system and is designated a constant head boundary with an elevation of 290
feet (MSL) for both the UCRS and the RGA.
11
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Not To Scale
d5
. 5811 grd)
fOCel1e SoLJtnW OSit5
(,niCI<8f1 t81 peP
"l1el1
Col1t1
£:')(\8Uh
J\PPtQ)('il11 g ~rolJhQ C\
qte l ~lJtf
. of ~~D~C&tioh &ce
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&ID
epOSits
loess
.,
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o..v\
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.-
Figure 4. Conceptual Site-Specific Geology in the Vicinity of the Paducah Gaseous Diffusion Plant
-------
The Porters Creek Clay is a predominantly clay layer that appears as a confining layer
to the McNairy Formation only at the southern portions of the PGDP site, and is
absent beneath most of the site. The exact northerly extent of this layer is not certain,
but it appears to extend only slightly north of the terrace.
The McNairy Formation consists of interbedded and interlensing sand, silt, and clay.
This unit is approximately 225 feet thick and lies at depths ranging from 70 to 100 feet
below the ground surface. Regionally, the McNairy grades from predominantly sand
near the Mississippi River Valley to both sand and clay near the PGDP. Water within
this unit moves probably in a northerly direction with discharge areas along the
Ohio River.
Various testing methods were used to characterize these units with respect to
conductivity, transmissivity, storativity, and hydraulic gradient. Investigative
methods include collection of monthly water level data from monitoring wells
onsite and offsite of the plant, aquifer pump tests, slug tests and numerical modeling
and optimization of the site. The most complete set of conductivity data for the area
comes from slug tests performed on the various hydrogeologic units.
In 1990, DOE commissioned the Phase I Ground Water Study which prepared a three
dimensional ground water flow model of the PGDP. This model has been updated
into a regional three dimensional ground water flow model for the PGDP and an
optimization plan for well placement by means of a three phase study incorporating
the results of new data obtained at the plant since 1990. The Phase I Ground Water
Study which was completed in March, 1992 served to outline the strategy proposed to
meet the objectives for the updated three phase study. Specifically, Phase 1 outlined
the current conceptual model and new hydrogeologic data to be incorporated into
the new model.
The Phase II Ground Water Study incorporated the new data and conceptual model
revisions into an updated three dimensional flow model. Calibration and sensitivity
analyses also were conducted. This phase was completed in August of 1992. The
Phase III Ground Water Study is the latest optimization plan for well placement
utilizing the results from the updated Phase II Ground Water Study flow model.
This phase was completed in December of 1992 .
The model is based on a USGS finite difference block centered numerical code called
MODFLOW. This code allows variable grid dimensions, layer thickness and a mixed
distribution of aquifer parameters. In addition, MOD FLOW is modular, which
means that additional programs may be used in conjunction with the main code.
Additional enhancement codes have been utilized for purposes of modeling the
13
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PGDP to mathematically determine the best well locations and optimal pumping
rates necessary to contain the plume.
The model was calibrated by matching computer generated water levels to observed
water levels. Calibration helped to determine layer elevations and hydraulic aquifer
parameters. Following calibration, the pathway and rates of ground water
movement were modeled using particle tracking.
Contaminant Characteristics
The contaminants of concern within the Northwest plume are TCE and 99Tc. TCE
was commonly used onsite as an industrial solvent for several years. This
halogenated compound is designated as a dense non-aqueoUs phase liquid (DNAPL)
due to the characteristic insolubility at high concentrations and a higher specific
gravity than water. Once released into the environment TCE tends to travel by
gravity in a downward path. Lateral movement results predominantly by contact
with low permeable areas and capillary action. Due to the insolubility, TCE will tend
to travel along bedding planes regardless of the direction of ground water flow.
DNAPLs tend to persist for long periods, while slowly releasing a dissolve phase into
the ground water.
99Tc is the most widespreadradionuclide present at PGDP. This radionuc1ide
resulted as a by-product of the reprocessing of uranium. The introduction of TCE.
and- 99Tc into the ground water was probably due to the past handling or disposal
practices. 99Tc is very soluble in water and will tend to readily migrate in the
direction of normal ground water flow.
2.6 Summary of Site Risks
The findings of an assessment of potential risks to public health and the
environment as a result of the contamination migrating offsite was reported in the
Draft Results of the Public Health and Ecological Assessment, Phase II (Document
#KY /SUB/13B-97777CP-03/1991/1, 1991). Contaminated residential wells are
currently. not being utilized for domestic use of ground water. However, the
domestic use of off-site ground water is a potential future exposure pathway.
The results of the Draft Results of the Public Health and Ecological Assessment,
Phase II (PHEA) suggested potential adverse effects from domestic use of ground
water based on the estimated excess lifetime cancer risk and hazard indices.
Trichloroethylene. from off-site monitoring wells created a potential increased
lifetime cancer risk for the sum of ingestion and inhalation pathways. The
14
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concentration of TCE within the area of the planned interim action is above 1,000
~g/l, while the Maximum Contaminant Level (MCL) cited in the Safe Drinking
Water Act (SDW A) is 5 ~g/l.
The PHEA found that the critical exposure pathway is related to the offsite migration
of on-site contaminant sources. The PHEA also recommended action to eliminate
the off-site migration of these contaminants. Based on the preliminary results of the
PHEA and the ground water studies, ooE, EPA, and the Kentucky Division of Waste
Management have decided that there is sufficient potential risk to the public and
environment to warrant an interim action. The principle goals of this interim action
are to decrease the risk by mitigating the spread of the high concentration portion of
the Northwest Plume, retarding the migration of the contaminants emanating from
the source area, and to provide mass removal of the contaminants in the Northwest
Plume. Prior to the implementation of the final remedial action a baseline risk
assessment will be conducted on the ground water integrator operable unit.
2.7 Description of Alternatives
Two alternatives were considered for addressing the ground water contamination in
the Northwest Plume. The first alternative would be to take no action at this time
and simply allow the ground water to continue to migrate toward the Ohio River.
The second alternative would provide for an interim action which will alter the
hydraulic gradients through ground water extraction. This second alternative will
initiate containment of both the source and high concentration areas of the ground.
water plume. These two alternatives are described in greater detail in the subsequent
paragraphs.
Alternative 1 - No Action
Pursuant to Section 3OO.430(e)(6) of the NCP, DOE is required to consider a no action
alternative. This alternative is useful as a baseline for comparison between potential
alternatives. Under this alternative no further action would be taken with regard to
the contaminated ground water.
15
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Alternative 2 - Extraction and Treatment, and Innovative Technology Treatability
Study'
This alternative involves the operation of a pilot extraction and treatment system to
initiate hydraulic containment of the source area and the centroid of the plume. The
selected remedy will include the following activities:
. i)
The contaminated ground water,will be extracted at two locations. The
first location, immediately north of the plant on DOE property, is to
initiate control of the source. While the second ground water extraction
location is offsite of the DOE reservation at the northern tip of the most
contaminated portion (greater than 1000 ~g/l of TCE) of the plume. The
contaminated ground water will be pumped at a rate to reduce further
contribution to contamination northwest of the plant without changing
hydraulic gradients enough to mobilize Dense Non-aqueous Phase
Liquids (DNAPL) or significantly affect other plumes. This pumping
rate may be modified during operation to optimize hydraulic
containment by adjusting flow from the extraction wells and to support
subsequent actions.
ii.)
The extracted ground water will be collected in a manifold and piped to
the treatment system, which will consist of two ion exchange units in
parallel followed by an air stripper with filtration for off gas emissions.
iii) The amount of treated water discharged will be limited by the flow
capacity of the skid mounted treatment units. The treated water will be
discharged through Kentucky Pollution Discharge Elimination System
(KPDES) permitted outfall 001.
. iv) This inte~ action also includes implementation of a treatability study
to evaluate an innovative technology. The innovative technology to be
studied involves the potential utilization of iron filings as a viable
alternative to pump and treat technology for ground water treatment.
v)
The remedy does not address source remediation, however; the remedy
will address continuing release from a DNAPL principal threat source
area.
Approximately fourteen (14) months will be required to design and construct the
selected remedy prior to initiation of operation and maintenance activities. This
pilot system will be evaluated for a period of 2 years to determine the treatment
16
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efficiency of the extracted ground water, the effect of extraction on the RGA, and to
evaluate the potential benefit of an innovative technology (treatment with iron
filings) Alternative 2 as developed in the Focused Feasibility Study and presented in
the Proposed Plan, satisfies all identified ARARs for the interim action cited within
this document.
2.8 Summary of the Comparative Analysis of the Interim Alternative
This section provides the basis for determining which alternative (i) meets the
threshold criteria of overall protection of human health and the environment, State
approval, and compliance with ARARs, and (ii) provides the best balance between
effectiveness and reduction of toxicity, mobility, or volume through treatment,
implementability, and cost, and (iii) satisfies community acceptance. Because of the
limited scope of this interim action, the comparative analysis focuses on the selected
remedy, while considering the no action alternative under the appropriate criteria.
Federal law requires nine criteria be used for evaluating the expected performance of
remedial actions. The nine criteria are introduced below and the present proposal is
evaluated on the basis of these criteria. Because this action is intended to integrate
both RCRA and CERCLA requirements, State acceptance has been substituted for
State approval and listed as one of the threshold criteria. This change is necessary to
reflect the fact that this interim action was initiated under the provisions of the
Kentucky Hazardous Waste Permit and must fulfill those RCRA requirements.
1. Overall protection of human health and the environment. Requires that
the alternative adequately protect 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 applicable or relevant and appropriate requirements
(ARARs). The alternatives must be assessed to determine if they attain
compliance with applicable or relevant and appropriate requirements of
both state and federal law .
3. Long.term effectiveness and permanence. Focuses on the magnitude and
nature of the risks associated with untreated waste and/or treatment
residuals. This criterion includes consideration of the adequacy and
reliability of any associated engineering controls, such as monitoring and
maintenance requirements.
17
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4. Reduction of contaminant toxicity, mobility, or volume through
treatment. The degree to which the alternative employs treatment to
reduce the toxicity, mobility, or volume of the contamination.
5. Short-term effectiveness. The effect of implementing the alternative
relative to the potential risks to the general public, potential threat to
workers and the time required until protection is achieved. .
6. Implementability. Potential difficulties associated with implementing the
alternative. This may include: the technical feasibility, administrative
feasibility, and the availability of services CiI\d materials.
7. Cost. The costs associated with the alternatives. These include the capital
cost, annual operation and maintenance and the combined net present
value.
8. State approva 1. The incorporation of any formal comments by the
Kentucky Division of Waste Management to the Interim Measure for the
Northwest Plume.
9. Community acceptance. The consideration of any formal comments by
the community to the Proposed Plan for interim remedial action.
The criteria listed above are categorized into three groups. The first, second, and
eighth categories are threshold criteria. The chosen final alternative must meet the
threshold critem to be eligible for selection. The five primary balancing criteria
include criterion three through seven. The last criterion is termed the modifying
criterion. The modifying criterion was evaluated following issuance of the Proposed
Plan for public review and comment.
Overall Protection of Human Health and the Environment
Alternative 1 doesn't provide protection of human health or the environment.
However, the risk cannot be quantified until a baseline risk assessment has been
conducted at this site. Alternative 2 is intended to serve as an interim action which
will provide protection to both the public and the environment by limiting the
migration of the contaminated plume. Additionally, Alternative 2 will provide
treatment of. the ground water to decrease the concentration of the specific
contaminants which are causing the threat. .
18
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Currently, the threat of direct exposure to the contaminated ground water has been
mitigated by the supply of a clean alternative water source to the affected residences.
However, due to the persistence of this form of contamination in ground water the
potential exists for risk to future water well users.
Compliance with ARARs
Table 1 lists the ARARs for this interim remedial action. This table only lists those
ARARs pertinent to the limited scope of this interim remedial action. Therefore the
ARARs listed in Table 1 pertain to the extraction and treatment system operations
and not to any ARARs associated with aquifer remediation goals. Such ARARs will
be addressed in subsequent remedial actions. In some instances, rules cited contain
both substantive and procedural or administrative requirements. In accordance with
the NCP, only the substantive requirements are ARARs.
Alternative 2 as developed in the Focused Feasibility Study and presented in the
Proposed Plan, satisfies all identified ARARs for the interim action cited within this
document. No ARAR waivers were necessary.
Long-term Effectiveness and Permanence
The no action alternative could cause potential health and environmental impacts
to occur through a future exposure scenario. The extraction and treatment system is
intended as an interim action until sufficient information can be accumulated to
formulate the final solution for this integrator operable unit. This action is intended
to be consistent and appropriate with the final remedial action. The effectiveness and
efficiency of this system will be evaluated for potential final actions. Additionally,
the treatability test for the in situ reactor concept will be evaluated to determine its
feasibility as a future remedial solution. This potential future action uses an
innovative passive system which utilizes iron filings to efficiently remove
contaminants while also providing cost effectiveness.
Reduction of Toxicity, Mobility, or Volume Through Treatment
The extraction and treatment system would serve to reduce the mobility of the
contamination by initiating control of the source area and preventing further spread
of the high concentration areas of the ground water plume. Further, the extracted
ground water will be treated by ion exchange and air stripping to lower the
concentration of the contaminants to reduce the toxicity and volume of the
contaminants. The potential exists for the 99Tc to become concentrated within the
19
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Table 1. Applicable or Relevant and Appropriate Requirements CARARs) and Guidance for the Hydraulic Containment of Off-Site Ground
Water
~
Title 401, KARa
Actions Requirements Prerequisites Federal citation Chapter
CHEMICAL-SPECIFIC
Treatment of Prevent creation of any new pollution Direct discharge of groundwater 10 5:029(2)
contaminated a surface water body - applicable
ground water
Discharge must not exceed OCGse for Direct discharge of groundwater 10 DOE Order 5400.5
radionuclides; discharge of radionuclides a surface water body - Tud
must not exceed 1 rad/day for protection of 8uidance
aquatic or~anisms
Protection of the The general public must not receive an Dose received by the general DOE Order 5400.5
general public from effective dose equivalent greater than 100 public from all sources of radiation
all sources of mrem/year exposure at a DOE facility. TUC
radiation 8uidance
All releases of radioactive material must be Releases of radioactive material DOE Order 5400.5
"as low as reasonably achievable" (AlARA) from DOE activities - TUC
guidance
Protection of the No member of the general public shall Emissions of radionuclides to the 40CFR 61.92; DOE
general public from receive an effective dose equivalent greater ambient air from DOE facilities - Order 5400.5
all sources of air than 10 mrem/year Applicable
emissions
Worker protection Maintain worker exposures to ALARA Internal and external sources of DOE Order 5480'.11
continuous exposure 10
occupational workers at a DOE
facility - TUC guidance
Maximum exposure to occupational workers: Internal and external sources of DOE Order 5480.11
5 rem/year (stochastic); 50 rem/year continuous exposure 10
(nonstochastic) effective dose equivalent occupational workers at a DOE
facility - TUC guidance
tOCA TlON-SPECIFIC
Protection of the Prepare an Environmental Impact Statement Any federal action that will have a . 10 CFR 1021; 40 CFR
environment (EIS) or Environmental Assessment (EA) or significant impact on the quality of 1500-1508; 57 FR 15122;
apply for a Categorical Exclusion (CX) from the environment - Applicable DOE Order 5440.10
such
requirements
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Table 1.
Applicable or Relevant and Appropriate Requirements (ARARs) and Guhhnce for the Hydraulic Containment of Off-Site Ground
Water
(Continued)
N
.....
Title 401, KARa
Actions Requirements Prerequisites Federal citation Chapter
ACTION-SPECIFIC
Site preparation Reasonable precaution must be taken to Handling, processing, construction, 63.010
prevent particulate mailer from becoming road grading, and land clearing
airborne activities - Applicable
Surface water control Implement good site planning and best Construction activities at industrial 40 CFR 122 5080.1
management practices to control storm water sites involving disturbance of 5
discharges; acres lotal land - Applicable if
comply with storm water runoff requirements over 5 acres disturbed; relevant
of KPDES Permit KY0004049 and appropriate if less than 5
acres disturbed
Well construction Construction by a certified driller required; Commercial water well drilling - 6310.3(1);
construction report must be submitted to the Applicable 6:310.3(2)
Cabinet within 30 days after construction
Pumping Compliance with the substantive Water withdrawal exceeding 10,000 KRS 151; 4:010
requirements of the water well withdrawal gallons/day - Applicable
permitting process must be assured for a
CERCLAg response
Must apply for a water withdrawal permit Water withdrawal exceeding 10,000. KRS 151.140;
gallons/ day - While substantive 4:010
requirements are applicable;
procedural requirements are
not applicable
Air stripping Must ensure that emissions do not exceed Emission from air contaminant 63.022
standards for control of emissions of volatile source - Applicable
or~anics.
Air construction permit application required Construction of an air contaminant 50:035
for an air contaminant source. source - While substantive
requirements are applicable;
procedural requ irements are
not applicable
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Table 1. Applicable or Relevant and Apprrpriate Requirements (ARARs) and Guidance for the Hydr~ulic Containment of Off-Site Ground
.Water
(Continued)
~
Actions Requirements Prerequisites Federal citation Title 401, KARa
Chapter
Air stripping Must apply for a Wastewate Facility Construction of a water treatment KRS 151.140;
(cont.) Construction Permit facility - While substantive 4:010
requirements are applicable;
procedural requirements are
nol applicable
Container Storage Containers of hazardous waste must be: Storage 01 RCRA hazardous waste 40 CFR 264 (Subpart I) 34:180.
(on -site) (listed or characteristic) not
- Maintained in good condition; meeting small quantity generator 40 CFR 264.171 34:180.2
, criteria held for a temporary period
- Compatible with hazardous waste to be before treatment, disposal, or 40 CFR 264.172 34:180.3
stored; and storage elsewhere, in a container
(i.e., any portable device in which a
- Closed during storage (except to add or material is stored, transported, 40 CFR 264.173 34:180.4
remove waste). disposed of, or handled). A
generator who accumulates or
Inspect container storage areas weekly for stores hazardous waste on-site for 40 CFR 264.174 34.180.5
deterioration. 90 days or less in compliance with
40 CFR 262.34(a)(1-4) is not subject
to full RCRA storage requirements
- Applicable
Place containers on a sloped, crack-free base, 40 CFR 264.175 34:180.6
and protect from contact with accumulated
liquid. Provide containment system with a
capacity of 10% of the volume containers.
Remove spilied or leaked waste in a timely
manner to prevent overflow to the
containment system.
At closure, remove all hazardous waste and 40 CFR 264.178 34:180.9
residues from the containment system and
decontaminate or remove all containers,
liners.
. .-
<~
..>
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Tal>~e 1.
Applicable or Relevant and Appropriate Requirements (ARARs) and Guidance lor the Hydraulic Containment JI Off-Site Ground
Water
(Continued)
~
Title 401, KAROl
Actions Requirements Prerequisites Federal citation Chapter
Container Storage Storage of banned wastes must be in 40 CFR 268.50 37:050.2
(on-site) accordance with 40 CFR 268. When such
(Cont.) storage occurs beyond one year, the
owner/operator bears the burden of providing
that such storage is solely for the purpose of
accumulating sufficient quantities to allow for
proper recovery, treatment, and disposal.
Transportation of Waste must be manifested Treatment residuals exhibit a 40 CFR 262
treatment residuals RCRA hazardous waste
characteristic as defined by
Subpart C of 40 CFR ~ 261 and off-
site transportation occurs
Waste must be packaged and transported The treatment residuals are 49 CFR 172, 173,178,
accordance with DOT' requirements considered a RCRA hazardous and 179
waste by characteristic, or a
hazardous substance that equals or
exceeds a reportable quantity; and,
transportation in commerce occurs.
Applicable if DOE does not
close off the road to public use
during transport; if the
transport does not occur in a
DOE operated government
vehicle; or if access to the roads
is not controlled by the use of
gates and guards
Waste must be packaged and transported Transportation of hazardous DOE Order 5480.3
according to DOE requirements materials - TDC "uidance
Direct discharge of The discharge must comply with the KPDES Point-source discharge to waters of 40 CFR 122.44(a) 5:080.1
treatment system effluent limitations of KYOOO4049 for Outfall the United Statesm - Applicable
effluent 001.
Must apply for a KPOES permit modification Point-source discharge to waters of 5055
for increased discharge to Outfall 001. the United States"' - Applicable
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Table 1. Applicable r.r Relnant and Appropriate Requirements (ARARs) and G-Jidance for the Hydraulic Containment of Off-Site Grounrl
Water
(Continued)
QKAR = Kentucky Administrative Record,
b KPDES = Kentucky Pollutant Discharge Elimination System.
cCFR = Code of Federal Regulations.
d KRS = Kentucky Revised Statute.
eOCC = Derived concentration guide.
!rOC = "to be considered."
KCERCLA = Comprehensive Environmental Response, Compensation, and Liability Act of 1980.
h RCO = Ken~cky Radiation Control Board.
iRCRA = Resource Conservation and Recovery Act.
iCWA = Clean Water Act.
kCAMU = corrective action management unit, regulated under RCRA Subpart S (58 FR 8658, F~bruary 16, 1993).
'DOT = Department of Transportation. .
m The term "Waters of the U.S," is defined broadly in 40 CFR 122.2 and includes essentially any water body and wetland.
~
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ion exchange media. The DOE is prepared to provide for the handling and storage of
contaminated ion exchange material at PGDP.
Short-term Effectiveness
The remediation of ground water contaminated with organic solvents and
radionuclides is a long-term process. The treatment systems may require extensive
periods of time before the remedial objective can be defined and attained. This
interim action will provide effective short-term stabilization of the contaminated
plume.
The extraction and treatment will be conducted in compliance with all of the ARARs
cited in Table 1. This alternative will not pose a threat to nearby communities or the
workers associated with the operation and maintenance of the treatment system.
Workers associated with the construction and operation of the extraction and
treatment system will abide by the requirements of a site-specific Health and Safety
Plan (HSP). This HSP will be prepared as part of the bid package and submitted to the
selected contractor prior to the award of the project. Prior to implementation of this
interim action the EPA and KDEP will be provided the opportunity to review the
HSP. The draft HSP will be modified by the contractor to reflect pertinent comments
by the Regulatory Agencies.
Implementability
The ground water extraction, and air stripping, cited in Alternative 2 are readily
available technologies and no difficulty should be encountered in finding vendors to
supply the treatment equipment. Experience with large scale treatment for 99Tc,
however, is limited and data on the capacity of the ion exchange resins selected for
this action is incomplete.
Cost
The estimated capital cost of the extraction and treatment system is between $11-12
million with an annual operating cost of between $1.5-2 million. A complete
breakdown estimate for the costs associated with Alternative 2 is included in Table 2
of this document. DOE considers the expenditures associated with extraction and
treatment to be reasonable and appropriate for this interim remedial action.
25
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PILOT PLANT
Table 2. Surface waterdischarge Air Stripper with carbon filtration, double-walled piping
....P---"-...---.----.--.."..---...."----..-----.-.-"-_.-.------
tV
0"\
submersible pumps
well installation
observation wells
aquiler test
valves
ion exchange
cost 01 conI. and storage of spent resin
Air Stripper with carbon filtration
process pumps
well development water
soil dispose
housing(inc.fire prol.' site prep.,etc.)
utilities re!ocation
piping (double-walled)
construction
Gas chromatography
Scintillation counter
relrigerator
lence
HVAC
lighting
In line pH
pH meter
Resistance Temperature Detectors (RTDs)
RTD output
Analyses (annual rate)
Technicians(hours)
Process Control Equipment
Data Management
Communications and alarm
health and salety requirements
differential pressure meter
T olal direct
...__a_.---.-..-...---.-"----------------....."---"-.."-.-.--_.....
ta~(6%)
sublolal
--------....------..-.....-......-..----..--.-...........--..............-......
lolal indirect (26%)
subtotal
......--........................-.......-......--...-..............-.................
construction mgl. fee (47%)
subtotal
.............--........---.................-....................-.--_........-.-
engineering design (25%)
subtotal
......--.....--------..............--..--.....................---..-------.-..--
escalation lactor (3%)
sublotal
-------...-------------......---...------.......---....------.-..------
contingency (25%)
tolal capilal investment
------------------------------------
------------------------------------
Materials
..------- --.-------------- ..--------.-------.-
aTY UNIT UNiT PR TOTAL
6 ea $1,066 $6,396
6 ea $95,700 $574,200
20ea $47.850 $957,000
1 Is $100,000 $100,000
50 ea $196 $9,805
4 units $20,000 $80,000
2 ea $104,710 $209,420
3 ea $1,066 $3,198
12000 gal $1 $12,000
12 cu yd $729 $8,748
1500 sq ft $45 $67,500
1 Is $75,000 $75,000
7200 feet $35 $252,000
$0
1 ea $25,000 $25,000
1 ea $100,000 $100,000'
3 ea $2,058 $6,174
100 ft $8 $800
$5,100
$20,000
4 ea $1,250 $5.000
1 ea $1,250 $1,250
10 ea . $95 $950
2 ea $2,215 $4,430
1 sys
1 Is
8 ea
$600,000
$60,000
$10,000
$515,520
$5,560
$3,715,051
$515,520
$695
---.------.....-..-..--.
$222,903
$3,960,555
-----..-..-.--------.
$1,029,744
$4,990,299
-----..-------------..
$2,345,440 .
$7,335,739
-_._--------.-------
$1,633,935
$9,169,674
...--------..-------..
$275,090
$9,444,764
.-------------------
$2.361,191
$11,805,955
-----------
-----------
Subcontractor
Charges
----.----.------
TOTAL
$21,800
$800
$22,600
----..---.-.....--
Non-capitalized
Operating expense
UNITS
-------.----- ----------.--.-.----- .---------------- ------------..
TOTAL.
Utility Expense:
O&M Expense:
$2.600
$4,160
Total Operating
Expense ~r year:
Assuming:
Two years of operation
Discount rate= 7.00%
Inflation rate= 3.50%
Present worth cost=
-----------
-----------
$15,188,190
RATE
$66,800
. $32,850
$56,600
$500 $ 1 ,300,000
$58 $242,986
$1,719,236
..-..-------------
-------
State Approval
The Technical Memorandum, Proposed Plan and Draft ROD were issued for review
and comments by both the Commonwealth of Kentucky and the EP A. This
documentation was developed consistent with the RCRA Interim Corrective
Measures Work Plan. The Kentucky Division of Waste Management concurs with
this action, consistent with the requirements of the Commonwealth of Kentucky's
RCRA permit.
Community Acceptance
Judging from the comments received during the public comment period, the
selected interim remedy specified in the Record of Decision is supported by the
residents of McCracken County, Kentucky; including the local PGDP Neighborhood
Council, and the PGDP Environmental Advisory Committee. The United States
Environmental Protection Agency, Kentucky Division of Waste Management, the
Tennessee Valley Authority, and the United States Department of the Interior also
concur with the selected remedy.
Groups and organizations which oppose this interim action include the Association
of Concerned Environmentalists, the Coalition for Health Concern, and the
Kentucky Radiation Control Branch (RCB). Those opposing the interim remedial
action generally expressed a concern that insufficient information is available to
select a remedial action and that this remedy is not cost effective.
Community response to the alternatives is presented in the responsiveness
summary which addresses comments received during the public meeting and the
public comment period.
2.9 Selected Remedy
The selected remedy for the interim action at the Northwest Plume is Alternative 2.
The principle objectives of this action are to initiate a first phase remedial action,
which in combination with possible future remedial actions for ground water, will
ultimately result in achieving the final remedial goals for the site. The ground water
will be extracted at two locations and pumped to mobile treatment units. The first
well location is just north of the plant on DOE property. The second well location is
at the northern tip of the most contaminated portion (TCE greater than 1000 Ilg/I) of
the plume (Figure 3). The contaminated ground water will be pumped at a rate based
on the predictions provided by ground water modeling. The rate at which the
ground water will be extracted will be adjusted to reduce further contribution to
27
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contamination northwest of the plant without changing hydraulic gradients enough
to mobilize DNAPL or significantly affect other plumes. Data gathered during the
operation will be used to modify the model in order to optimize hydraulic
containment by adjusting flow from the extraction wells.
The extracted ground water will be collected and piped to the treatment system
consisting of two ion exchange units followed by an .air stripper unit.. The amount of
water discharged will be limited by the flow capacity of the skid mounted treatment
units. The treated water will be discharged through Kentucky Pollution Discharge
Elimination System (KPDES) pennitted outfall 001. This outfall is located on DOE
property and discharges into Big Bayou Creek.
Ion exchange is a process by which an ion is captured from a solution and replaced
with a different ion. The capture takes place by' chemisorption onto an
electrochemiCally charged resin surface. Anion exchange resin beads are composed
of chemicals which carry positive. charges. The resin contains anions adsorbed onto
the surface of the resin beads. Pertechnetate (fc04') ions have a greater affinity for
the resins under consideration than other ions in the ground water so that
pertechnetate ions tend to preferentially adsorb onto the surface of the resin. Lab and
bench scale studies using ion exchange to remove 99Tc have shown this method to
be effective.
Air stripping is a process by which water containing VOCs is brought into contact
with air. The stripper will be designed to reduce the concentrations of TCE in the
water. Other VOC contaminants such as TCE degradation products are present in
much smaller concentrations so that an air stripper that removes the TCE will also
remove other volatiles that might be present. The effectiveness of this technology is
enhanced by exposing an increased surface area of contaminated water with the
airstream. This is accomplished by performing the operation in packed towers.
Conventional air strippers spray water into the top of the column and allow the
water to trickle over the packing. Air is blown into the bottom of the tower and
contacts the water in a counter-current flow. In the event that air stripping is
selected, it will be necessary to install a filter system to eliminate mobilization of
contamination into the air. The decision to install these filters is based upon EP A
OSWER Policy Directive 9355.0-28, and Sections300.430(e)(7)(i) and
300.430(e)(9)(iii)(D) of the NCP, which sets forth the statutory preference for
implementing actions which employs effective treatment.
It may be necessary to obtain a permit for discharging TCE into the airstream. A
Kentucky water withdrawal permit may also be required by the State for withdrawal,
diversion, or public transfer of more than 10,000 gallons per day public water from its
28
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source. The State also may require construction and operating permits for the
construction of the wastewater treatment facility. Estimated cost of the hydraulic
containment remedy is presented in Table 3.
The ooE will begin to prepare a detailed design of the treatment system when EP A
and the Kentucky Division of Waste Management concur with the ROD for this
interim action, in accordance with the approved ICM Work Plan. The conceptual
proposal presented in the Technical Memorandum for Interim Action of the
Northwest Plume suggests the following system. Ground water would be pumped
into a manifold where it will be routed to the water into the treatment system. A
sample valve would be installed just before the treatment system for inlet water
sampling. The water then passes through an inlet filter which removes suspended
solids from the water. A side stream is pulled off after the inlet filter to supply the
treatability study for the iron filings reactor on the south treatment system. The
other treatment system will not have an iron filing reactor. The next split in the line
allows the air stripping process to occur prior to 99'fc removal if desired. The influent
is split into two streams to supply each of the ion exchange columns. Both streams
pass through flow rate meters and cumulative flow meters in route to the ion
exchangers. From the ion exchange columns, the water passes another sample point
and through a second anion exchange column to monitor the discharge for
radiation. The treated water from the bottom of the air stripper is pumped to either
discharge or to the 99Tc treatment loop. A sample valve is provided after the pump
discharge line.
The primary parameters to be monitored are the influent and effluent
concentrations of contaminants. The data quality objectives (DQO) for these
parameters will include level I (field data), II (field scintillation), and III (laboratory
data). Influent and effluent concentrations will be monitored on a daily basis
throughout the testing program. Each treatment system will be sampled on alternate
days. Analytes initially will included 99Tc, TCE, and pH, although this list may be
expanded or reduced as the program evolves upon concurrence by EP A and KDEP.
Piezometric measurements of the water table will be made throughout the program
to gather data necessary for ground water modeling and to demonstrate gradients
toward the collection wells. These measurements will meet the criteria for DQO
level I.
Cumulative flows will be monitored in order to establish resin capacity in the ion
exchange treatment system. The DQO level for these measurements will be level 1.
DQO level] & II analyses will be performed by personnel on-site. Each treatment
29
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Table 3. Estimated Cost of Hydraulic Containment Remedy
Surface water discharge, Air Stripper wnh carbon fmration, double-walled piping
Capnallnvestment of Hydraulic Containment Option
w~h Air Stripping and Ion Exchange Systems:
1. Ion Exchange System:
$202,223
$529,370
2. Air Stripping System:
3. Well Installation, laboratory construction, piping and miscellaneous:
Subtotal
$8,713,171
- $9,444,76!.
Contingencies @25%:
$2,361,191
$11,805,955
Total Cap~allnvestment:
Estimated Operation and Maintenance Expense (annually):
- !1,719,23L
TOTAL COSTS:
Net Present Value assuming an inflation rate of 3.5%,
a discount rate of 7% and two years of operation:
$15,188,190
30
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facility will be sampled every other day. Monthly samples will be taken from both
treatment facilities on the first working day of each month. The frequencies may be
changed when sufficient data has been accumulated to make more informed
judgments about data adequacy. Changes in frequencies or in operating parameters
will occur only after concurrences by EP A and the Commonwealth of Kentucky.
Monthly replicate samples taken by on-site personnel will be analyzed by laboratory
personnel. The cost of the analysis of the replicates is estimated to be $l00/sample for
TCE, $4O/sample for 99Tc, and $200/sample for metals. Other compounds that will be
analyzed on a monthly basis include TCE degradation products and other organic
compounds.
Observation wells will be installed in the area. proximal to the extraction wells.
Approximately 20 observation wells will be installed near the pumping wells. Data
loggers will be installed in the well field to constantly monitor ground water level.
All observation wells will be use in the effectiveness monitoring program. The
purpose of the well effectiveness monitoring is to create and maintain an adequate
database on the hydrogeologic situation in the Northwest Plume and to enable
changes to be made in extraction/injection that will optimize remediation and
containment. This data base will be created using newly constructed and existing
wells.
Concurrent with the interim remedial action proposed in Alternative 2, was a
provision for a treatability study to examine a promising innovative technology. In
this treatability test, ground water will be extracted from wells just north of the plant
and diverted from the treatment facility to a cylinder packed with iron filings in'
order to ascertain the effectiveness of iron filings in destroying TCE and precipitating
99Tc. Studies examining sorption of organic contaminants on well casing materials
demonstrated that several chlorinated organic compounds disappeared from
solution over time when in contact with galvanized metal and aluminum. Further
investigation verified the disappearance of chlorinated organic compounds from
solutions when in contact with various metals. The same effect was later
demonstrated using iron filings. The reaction mechanism associated with this
innovative treatment technology has not yet been fully explained. Pilot
demonstrations have been conducted using an in situ reactor which consisted of a
wall composed of 22% by weight iron and 78% by weight sand constructed below the
ground perpendicular to the direction of flow of the ground water. A source of
mixed chlorinated organic compounds, induding TCE, was emplaced upstream of
the wall and it was demonstrated that the TCE concentration was reduced by 95% as a
result of passing through the reactive wall. Since iron will also reduce pertechnetate
ion to insoluble technetium dioxide, the reactive wall concept can also be used for
removal of 99Tc from the ground water.
31
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If the innovative technology is shown to be an effective treatment technology, a
feasibility study will evaluate use of this technology as a reactive material placed as a
vertical wall in the contaminated aquifer. The wall would be designed to allow
ground water to naturally flow through the reactive medium and be passively
treated without extraction and treatment at the surface. The reactive wall concept
shows great promise as a viable alternative to pump and treat technology for ground
water treatment. However, at this time, it is an emerging innovative technology
which needs further development before it can be utilized as a final remedy.
An additional aspect of the treatability study of this action is to evaluate, on a pilot
plant scale, the effectiveness of ion exchange technology in remediation of ground
water contaminated with technetium.
2.10 Statutory Determinations
The DOE, EPA and Kentucky Division of Waste Management concur that the
extraction and treatment system will satisfy the CERCLA ~ 121 (b) statutory
requirements of: providing protection of human health and the environment,
attaining applicable or relevant and appropriate requirements directly associated
with this action, being cost-effective, utilization of permanent solutions and
alternative treatment technologies to the maxhnum extent practicable, and a
preference for treatment as a principle element.
Protection of Human Health and the Environment
Although the ground water within the contaminated plume is not currently used as
a source of drinking water for the local residents, under future use scenarios it
presents a potential threat to human health and the environment. The interim
action remedy initiates protection of human health for the future users through
mitigation of the spread of the plume until a final action is detennined. The remedy
also provides protection to the environment by providing treatment of the extracted
ground water prior to discharge, and effective management of all residual wastes.
generated during implementation of the action.
Compliance with ARARs
The Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) of 1980 was passed by Congress and signed into law on December 11, 1980
(Public Law 96-510). This act was intended to provide for "liability, compensation,
cleanup, and emergency response for hazardous substances released into the
32
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environment and the cleanup of inactive waste disposal sites." The Superfund
Amendments and Reauthorization Act (SARA), adopted on October 17, 1986 (Public
Law 99-499), did not substantially alter the original structure of CERCLA but
provided extensive amendments to it. In particular, 9 121 of CERCLA specifies that
remedial actions for cleanup of hazardous substances must comply with
requirements or standards under federal or more stringent state environmental laws
which are applicable or relevant and appropriate to the hazardous substances or
particular circumstances at a site. Inherent in the interpretation of applicable or
relevant and appropriate requirements (ARARs) is the assumption that protection of
human health and the environment is ensured.
CERCLA on-site remedial response actions must only comply with the substantive
requirements of a regulation and not the administrative requirements to obtain
federal, state, or local permits [CERCLA 9 121(e). For the purposes of this ARAR
summary, remediation of off-site ground water at PGDP is considered an "on-site"
CERCLA response pursuant to the National Contingency Plan, 40 C.F.R. 9300.5.]
The final cleanup levels for the ground water are not addressed in this ROD because
such goals are beyond the limited scope of this action. The final cleanup levels will
be addressed by the final remedial action ROD for the ground water integrator
operable unit.
The treatment system for the extracted ground water will meet all Federal and State
surface water quality standards. Additionally, the air stripper will be designed to
meet the Federal and State air quality standards. The treated ground water will meet
the substantive requirements of the Kentucky Pollutant Discharge Elimination
System (KPDES) program for discharge to surface water.
A listing of ARARs (chemical-specific, location-specific, and action-specific) are
provided in Table 1 of this document. Pursuant to 300.430(f)(1 )(ii)(C) of the NCP an
alternative which doesn't meet federal or state ARARs can be selected if the action is
an interim measure that would become part of a final action which will attain
ARARs.
Chemical-Specific ARARs
The principal contaminants of concern in the off-site ground water are 99Tc and TCE.
Therefore, available chemical-specific criteria that have been promulgated under
federal and Kentucky state law that are applicable to this response action are listed in
Table 1. TCE degradation products, metals, and gross alpha and beta activity will be
included in the list of analytes and analyzed on a routine basis.
33
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The Kentucky Water Quality Standards nondegradation policy [Title 401 Kentucky
Administrative Record (KAR), Chapter 5:029(2)] is to safeguard the surface waters of
the state for their designated uses, to prevent the creation of any new pollution, and
to abate existing pollution. The Kentucky regulations list. six use-designation
categories for Kentucky's surface waters (KAR 5:026). Specific water quality standards
are promulgated for each use category. Big Bayou Creek is not specifically listed and
given a use classification in the Kentucky water regulations (401 KAR 5:026);
however, it is classified by reference for warm water aquatic habitat, and primary and
secondary contact recreation [401 KAR 5:026; KAR 5:200(2)]. The Kentucky WQC for
warm water habitat are found in Title 401 KAR 5:031.
Also listed on Table 1 are the effluent limitations established for Outfall 001 on Big
Bayou Creek (KPDES Permit No. KY0004049). This permit was revised and reissued,
effective November 1, 1992.
The cheriucal-specific federal and state regulations for protection of the surface water
are presented below in Table 4.
Table 4.
Chemical-Specific Federal and State Regulations for Protection of Ground
Water and Surface Water (f.1g1L)
Chemical
Acute
Criteria
Chronic
Criteria
KPDESd Permit
No. KY0004049
Effluent
Characteristics
(Monthly avg.)
KAR Warm Water
Aquatic Habitat WOCC
Trichloroeth y lene
Radionuclides
Gross alpha
Gross beta
Uranium
All other man-made
radionuclides
81
report
report
report
report
awc:x:. = water quality criteria; Title 401 Kentucky Administrative Regulations (KAR), Chapter 5:031,
unless otherwise footnoted.
bKPDES = Kentucky Pollutant Discharge Elimination System.
C Daily maximum.
34
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Radiation Protection Standards
Very few applicable standards are available for the cleanup of radioactively
contaminated CERCLA sites. The Atomic Energy Act (AEA) of 1954 and its
amendments delegated authority for control of nuclear energy to DOE, the U.S.
Nuclear Regulatory Commission (NRC), and EP A. In addition, certain states have
regulatory authority and programs for radioactive waste. EPA's regulations are
derived from several other statutes as well and cover many types of activities and all
types of radioactive materials. The NRC licenses the possession and use of various
types of radioactive materials at certain types of facilities. Kentucky is an NRC-
agreement state and, as such, has its own authority and licensing regulations. DOE is
authorized to control all types of nuclear materials at sites under its jurisdiction and
is exempt from the NRC licensing and regulatory requirements.
DOE regulations for handling and cleanup of radioactive materials are outlined in a
series of internal DOE Orders that are contractually binding to DOE contractors but
are not considered by EP A to be ARARs. However, DOE Orders are "generally"
consistent with, and "typically" incorporate NRC technical requirements that are
appropriate for DOE operations and waste management. Therefore, for the purposes
of development of ARARs, DOE Orders will be treated as TBC guidance.
If any wastes generated during drilling of wells or as treatment residuals contain
radionuclides and are identified as RCRA~haracteristic waste, the waste would then
be termed "mixed waste." In effect, mixed wastes are those containing a RCRA
hazardous waste as defined in 40 C.F.R. 9 261 and a radioactive waste subject to the
AEA. RCRA regulations apply to the hazardous component of the waste, and AEA
regulations apply to the radioactive component. When the application of both
standards is conflicting or inconsistent, RCRA yields to the AEA. Kentucky received
final authorization to regulate radioactive mixed waste on December 19, 1988 (53 Fed.
Reg. 41164, October 20, 1988); however, the state has not implemented any
regulations governing the radioactive component of mixed waste.
EP A has promulgated MCLs for radionuclides in community water systems. These
MCLs appear in two forms-<:oncentration limits for certain alpha-emitting
radionuclides (40 C.F.R. S 141.15) and an annual dose limit for the ingestion of
certain beta- and gamrna-emitting radionuclides (40 C.F.R. S 141.16). Kentucky lists
MCLs in the Kentucky Public and Semipublic Drinking Water Regulations, Title 401
KAR Chapter 8:550, Section 4 which are identical to the federal MCLs. The use of
MCLs as ARARs are not appropriate for this action due to the fact that the extracted
water will not be reinjected back into the aquifer and the scope of this interim action
35
-------
is not intended to provide ground water restoration. However, the treatment system
described in Alternative 2 will be designed to provide treatment to levels comparable
with MCLs. Therefore, the MCL levels will be utilized as remedial goals. The
treatment system will remain within compliance parameters as long as the
applicable substantive KPDES requirements for discharge are maintained.
Subpart H of 40 C.F.R. S 61 addresses atmospheric radionuclide emissions from DOE
facilities and may be applicable to airborne emissions during cleanup of
~ontaminated ground water. EP A has issued a final NESHAP rule (54 Fed. Reg.
51654, December 15, 1989) that limits emissions of radionuclides to the ambient air
from DOE facilities to amounts that would not cause any member of the public to
receive an effective dose equivalent of 10 mrem/year (40 C.F.R. S 61.92).
DOE Orders. The radiation exposure limits {or the general public defined in DOE
Order 5400.5 (Radiation Protection of the Public and the Environment, February 8,
1990), are: an effective dose equivalent (EDE) of 100 mrem/year from all exposure
pathways and all DOE sources of radiation and, a dose of less than 500 rem/year as a
temporary maximum exemption under specially-permitted and DOE-approved
circumstances. The overriding principle of the DOE Order is that all releases of
radioactive material shall be ALARA.
DOE Order 5400.5 lists Derived Concentration Guides (DCGs) for radionuc1ide
isotopes which are based on a committed effective dose equivalent of 100 lrirem/year
for ingestion of air or water. For liquid wastes containing radionuclides which are
discharged to surface waters, the best available technology (BAT) must be used if the
receiving water, at the point of discharge, would receive radioactive material at a
concentration greater than the DCG. Guidelines for selecting the BAT are given.
Implementation of the BAT process is not required if annual releases to surface
water are below the DCG. In the case of releases of multiple radionuclides, the sum
of the' fractional DCGs must not exceed unity. The ingested water DCG for 99Tc is
1.0E-4 ~Ci/ ml. In addition, effluent releases to surface water must not resul t in
exposures to aquatic organisms which exceed an absorbed dose of 1 rad/ d.
Location-Specific ARARs
Location-specific requirements "set restrictions upon the concentration of hazardous
substances or the conduct of activities solely because they are in special locations" (53
Fed. Reg. 51394). Table 1 lists location-specific ARARs that might be pertinent to .this
remedial action.
36
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Aquatic resources. There are no federal wilderness areas, wildlife refuges, or scenic
rivers near PGDP. However, the land between the plant boundary and the Ohio
River was deeded or leased to the Kentucky Department of Natural Resources and
Environmental Protection as part of the West Kentucky Wildlife Management Area
(WKWMA). There are no federal or state regulations specifically applicable to
wildlife management areas. However, the Kentucky Department of Fish and
Wildlife (KDFW) manages the area. In the event that any remedial activities would
impact the WKWMA, DOE will consult with KDFW.
Action-Specific ARARs
Perfonnance, design, or other action-specific requirements set controls or restrictions
on particular kinds of activities related to the management of hazardous waste (52
Fed. Reg. 32496). Selection of a particular remedial action at a site will invoke the
appropriate action-specific ARARs that may specify particular performance standards
or technologies, as well as specific environmental levels for discharged or residual
chemicals. Federal and state regulations appear in Table 1 and are summarized
below.
Construction Activities
Site preparation. Certain on-site construction activities may be necessary to prepare
the site for remediation; these action might include the development of additional
roads for vehicular traffic or site cleaning activities. Airborne pollutants may result
from these construction activities. The primary concern is elevation of particulate
concentrations resulting from earth-moving and site-grading activities. The
Kentucky Air Quality regulations contain General Standards of Performance
governing fugitive dust emissions (401 KAR 63:010).
Storm water discharges from activities at industrial sites involving construction
operations that result in the disturbance of five acres total land have been included
in the final rule for NPDES permits for storm water discharges (40 C.F.R. ~ 122).
Kentucky is developing storm water discharge regulations; however, until they are
promulgated, they are operating under 40 C.F.R. ~ 122. This Rule specifies that Best
Management Practices and sediment and erosion controls be implemented at a site
to control storm water runoff (57 Fed. Reg. 41176, September 9, 1992). Kentucky does
have a general permit in place for storm water runoff from construction sites
(KYPlOOOOO).
Well construction. Although the construction of water withdrawal wells is regulated
under 401 KAR 6:310, this action will be exempted from this requirement. The
37
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regulation is not applicable for monitoring wells. However, wells must be
constructed by a certified driller [401 KAR 6:310(3)] according to specified design
factors [401 KAR 6:310(4)] and construction materials [401 KAR 6:310(9)], as well as
other'requirements. Requirements are also given for monitoring well construction
[401 KAR 6:310(13)J.
Pumping. Water withdrawal permits are required under authority of KRS 151 and
401 KAR 4:010 for wells or systems that pump greater than 10,000 gallon per day.
Although a permit is not required for a CERCLA action, the substantive
requirements of these regulations are applicable.
Treatment. As mentioned previously, no federal or state permits are required for on-
site CERCLA response. However, compliance with the substantive requirements of
any applicable permitting processes are required. An air stripper with an air filter
will be used to remove TCE and other degradation products from =the water column,
and an ion exchange column will remove radionuclides; mobile wastewater
treatment units will be utilized.
Air emission control. Kentucky, regulates air emissions via their Air Toxies
Regulation (401 KAR 63:022); the state has issued a "Guidance for Compliance with
the Air Toxics Rule." Since this is a CERCLA action, no air permit would be required
if emissions exceed the standards, but the threshold of TCE will not be exceeded in
the air stripper. However, compliance with the substantive requirements will be
fulfilled.
Disposal of treatment residuals. During operation, spent ion exchange elements or
other treatment residuals may be generated by the treatment unit. Accumulation or
on-site storage of this waste may be required prior to disposal. If the residuals are
RCRA-characteristic waste and are accumulated for greater than 90 days, the 40 C.F.R.
~ 264 regulations apply ("Container storage," Table 1). This wastewater treatment
unit selected for this action will be exempt from RCRA Subtitle C standards for tank
systems, conveyance'systems, and other ancillary equipment. Under 40 c.P.R. ~
270.1(c)(2)(v), the action would be considered an action under 9 402 or 307(b) of the
Clean Water Act, therefore fulfilling RCRA requirements for exemption.
Placement of treatment residuals containing RCRA-characteristic waste to another
unit that has not been designated as a Corrective Action Management Unit, will
,trigger the 40 C.F.R. ~ 268 LDR. However, DOE applied for a one-year case-by-case
extension under 40 C.F.R. ~ 268.5 of the May 8, 1992, effective date of the LDRs
applicable to Third/Third mixed wastes generated and stored at PGDP, as well as 30
other sites (57 Fed. Reg. 22024, May 26, 1992). Whether the waste is characterized as
38
-------
RCRA characteristic, LLW, or mixed waste, it will be stored at an appropriate facility
at PGDP which meets the substantive requirements of RCRA.
Transportation of treatment residuals. RCRA hazardous waste must be packaged in
accordance with Department of Transportation (DOT) regulations codified in 49
CF.R. 9S 175, 178, and 179 if transporting occurs along public roads. In addition to
the manifest and pre-transport requirements of 40 CF.R. 9 262, standards for labeling,
marking, and placarding are stated in 49 CF.R. 9 172. These requirements are
considered ARARs for hazardous or radioactive waste if the action meets the
prerequisites as a generator of a hazardous waste and the transportation of wastes
from the site to PGDP is considered an off-site action.
Disposal of Treated Media
Direct discharge to surface water body. Direct discharge to a surface water body (see
"direct discharge of treatment system effluent," Table 1) will be implemented if the
treated water meets CW A State Water Quality Criteria for the designated use of the
water body and the substantive requirements of the Kentucky Pollutant Discharge
Elimination System (KPDES) effluent standards for point source discharge to Outfall
001 (KPDES Permit KYOO04049). Table 1 lists these standards.
The extraction and treatment system would meet all of the regulatory requirements
cited as ARARs for this action. The final ground water effluent will meet all Federal
and State water quality standards for discharge to surface water. In the event that air
stripping is selected, it will be designed to meet the Federal and State air quality
standards. This may include receipt or modification of the necessary permits,
compliance with all maintenance and reporting requirements, and adherence to
treatment performance criteria.
It is premature to establish chemical-specific ARARs for ground water at this time.
Once the ground water is pumped to the surface, chemical-specific ARARs will apply
in the form of discharge limits. Location-specific ARARs such as wetlands protection
and action-specific ARARs such as monitoring wells will also apply.
Cost Effectiveness
The interim action remedy employs a proven technology which affords overall
effectiveness proportional to its costs such that the remedy represents reasonable
value. This action will utilize a relatively inexpensive technology to initiate control
of the source and mitigate the spread of the contaminated ground water. This
limited scale containment operation should reduce the cost of the overall
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remediation of the integrator operable unit by retarding the migration of the high
concentration portion of the plume. By extracting the ground water at the locations
proposed- in this document, DOE will be able to mitigate the area of highest
contamination through the use of four wells and portable skid mounted treatment
units.
.Utilization of Permanent Solutions and Alternative Treatment Technologies
The objectives for this interim action are to stabilize the site by mitigating the spread
of the. most contaminated portion of the plume. This action should provide
protection for human health and the environment. However, it does not fully
address the principle threats to human health and the environment posed by the
Northwest Plume operable unit. Extraction and treatment of contaminants in the
aquifer will achieve some reduction in the contamination at the site. This is not the
final action planned for the ground water contamination. Subsequent actions will
address fully the principle threats posed by the conditions at the PGDP. Utilization of
a permanent solution will be addressed in the final decision document for the site.
Preference for Treatment as a Principle Element
This interim action satisfies the statutory preference for treatment of the discharged
effluent as a principle element of the containment system.
2.11 Documentation of Significant Changes
The Proposed Plan for Interim Remedial Action of the Northwest Plume, was
released for public comment on March 18, 1993. The Proposed Plan identified
Alternative 2, extraction and treatment, as the preferred alternative. DOE has
reviewed all written and verbal comments submitted during the public comment
per.iod. Upon review of these comments, it was determined that no significant
changes to the remedy, as it was originally identifi~d in the Proposed Plan, were
necessary .
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