Tennessee

Tennessee

OakRidge
Reservation

Long-Term Stewardship Site Highlights
Oak Ridge Reservation (page 3)
Major Activities- maintaining engineered barriers; monitoring ground and
surtace water; enforcing institutional controls
Site Size -14,000 hectares (35,000 acres)
Estimated Average Annual Cost FY 2000-2006- $6,733,000

Table of Contents

Table of Contents

Oak Ridge Reservation ................................................................... 3

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National Defense Authorization Act (NDAA) Long-Term Stewardship Report

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Oak Ridge Reservation

OAK RIDGE RESERVATION
1.0

SITE SUMMARY

1.1

Site Description and Mission

The Oak Ridge Reservation (ORR), which occupies
approximately 14,000 hectares (35,000 acres), is
located almost entirely within the city limits of Oak
Ridge in eastern Tennessee, approximately 40
kilometers (25 miles) west of Knoxville.
The
Reservation was established in the early 1940s by the
Manhattan District of the U.S. Army Corps of
Engineers. Soon after the war, the U.S. Atomic Energy
Commission was formed to transfer the nuclear
enterprise to civilian control. Some 20 years later, other
energy programs were merged with the nuclear program
to ultimately become the U.S. Department of Energy
(DOE). The Reservation is composed of three primary
areas: the Oak Ridge National Laboratory, the East
Tennessee Technology Park, and theY -12 Plant. Work
performed in each area contributed to the Reservation's
major role in the enrichment of uranium or the
production of plutonium for the first nuclear weapons.

•

LONG-TERM STEWARDSHIP HIGHLIGHTS
Major Long-Term Stewardship Activities -maintaining

engineered barriers; monitoring ground and sutface
water; enforcing institutional controls
Total Site Area- 14,000 hectares (35,000 acres)
*Estimated Volume of Residual Contaminants- soil
1.1 million cubic meters (1.5 million cubic yards);
groundwater unknown; sutface water/sediments
166,300 cubic meters (217,500 cubic yards);
engineered units 4.2 million cubic meters (5.5 million
cubic yards); facilities 1,500 cubic meters (2,000 cubic
yards)
Portions Requiring Long-Term Stewardship as of
2006-6
Average Annual Long-Term Stewardship Cost FY
2000-2006- $6,733,000
Landlord- U.S. Department of Energy
*The estimated volume indicates only the known amounts of
residual contaminants. For certain portions discussed for this site,
exact volume is not known at this point. For specific discussions,
please see Section 3.0.

Oak Ridge National Laboratory occupies
approximately 1,350 hectares (3,300 acres)
within the Oak Ridge Reservation in Melton
and Bethel Valleys. The Laboratory's original mission was to produce and chemically separate the first
gram quantities of plutonium to support the production of the atomic bomb. Now, Oak Ridge National
Laboratory is a multiprogram science, technology, and energy laboratory with distinctive capabilities in
materials science and engineering, neutron science and technology, energy production and end-use
technologies, mammalian genetics, and ecological research. In support of the missions of DOE, Oak
Ridge National Laboratory conducts basic and applied research and development to create scientific
knowledge and technological solutions that strengthen the nation's leadership in key areas of science;
increase the availability of clean, abundant energy; restore and protect the environment; and contribute
to national security.
East Tennessee Technology Park (formerly called K-25) occupies 405 hectares (1,000 acres) within the
Oak Ridge Reservation adjacent to the Clinch River. The K-25 facility was used to enrich uranium
through the gaseous diffusion process. In 1987, the facility was shut down due to a decrease in demand
for enriched uranium. The facility is now involved in reindustrialization, environmental restoration, and
waste management activities.

•

Y -12 Plant occupies approximately 300 hectares (800 acres) within the Bear Creek Valley. The original
mission of theY -12 Plant was uranium enrichment and nuclear weapons production. Currently, theY -12
Plant is refocusing its technical capabilities and expertise to serve DOE and DOE-approved customers.
The Y-12 Plant continues to serve as a key manufacturing technology center for the development and
demonstration of unique materials, components, and services of importance to DOE and the nation.

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National Defense Authorization Act (NDAA) Long-Term Stewanlship Report

Portion/Watershed Boundary

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2

Specific focus areas for theY -12 Plant in coming years include: ( 1) weapons dismantlement and storage;
(2) enriched uranium materials warehousing and management; (3) nuclear weapons process technology
and development support; (4) Y-12 Plant management/landlord activities, including taking standby or
shutdown facilities into a safe, legally compliant condition; (5) identifying and managing the
decontamination and decommissioning of facilities; (6) providing unique capabilities and technologies
not found in the private sector on DOE-approved tasks; (7) transferring technology developed at DOE
facilities to enhance our industrial competitive edge in worldwide markets; and (8) maintaining and
supporting the National Security Office for DOE.
The Reservation has approximately 400 hectares (1,100 acres) of unlined radioactive and mixed-waste burial
grounds, inactive tanks, surplus facilities, and unlined ponds. As a result of past operations, approximately 1,500
hectares (4,000 acres) ofland in parts of the three primary areas and in other areas of the Reservation have been
or have the potential to be contaminated. Contamination is found in the soil, groundwater, surface water, and
two major rivers, the Clinch River bordering the Oak Ridge Reservation and the Tennessee River further
downstream. However, approximately 12,500 hectares (31,000 acres) of land on the Reservation are

1

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All maps shown for ORR reflect the current, as of year 2000, contamination at the site.

4


uncontaminated. DOE has begun remediation of the Reservation. The first phase of remediation involves
stabilizing the plants in support of their existing missions and will not be completed until after 2010. Additional
remediation may be needed as the missions change.
The current mission of the Oak Ridge Reservation is to continue research at the Oak Ridge National Laboratory,
continue national defense related activities at theY -12 Plant, and remediate the East Tennessee Technology Park
to allow for reindustrialization. Concurrently, environmental remediation will continue, in addition to required
long-term stewardship activities. The long-term stewardship activities consist of maintaining barriers to the
spread of contamination (engineered barriers), monitoring ground and surface water, operation and maintenance
of the wastewater treatment units, and enforcing institutional controls.

1.2

Site Cleanup and Accomplishments

Remediation at the Oak Ridge Reservation is based on five watersheds: Melton Valley and Bethel Valley at Oak
Ridge National Laboratory, East Tennessee Technology Park, and Bear Creek and Upper East Fork Poplar Creek
at the Y-12 Plant and is conducted in accordance with the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA). All remedial decisions to leave waste in place are considered
interim because the State of Tennessee is opposed to leaving waste in place in perpetuity without a set-aside longterm stewardship funding mechanism; however, DOE cannot commit to this funding mechanism. Remediation
levels for the Oak Ridge Reservation are expected to support the following uses: approximately five percent
restricted access, five percent controlled industrial (defined as industrial use on the surface), 15 percent
unrestricted industrial (defined as industrial use to three meters (10 feet) in depth), and 75 percent unrestricted.
In 2006, most of the remediation activities identified below will be partially completed; however, very few will
be fully completed. The following remediation discussion represents current DOE assumptions since most of
the Record of Decisions (RODs) have not yet been
signed.
OAK RIDGE NATIONAL LABORATORY
ACCOMPLISHMENTS

Oak Ridge National Laboratory
•

A CERCLA ROD for Melton Valley is nearing
signature, rendering most of the Melton Valley
discussion less likely to change than other portions in
this document. Under this ROD the large burial
grounds in Melton Valley will be hydraulically isolated
through caps and upgradient and downgradient
collection trenches for shallow groundwater. Some
transuranic waste will be excavated and disposed at the
Waste Isolation Pilot Project (WIPP). The liquid lowlevel waste seepage pits and trenches will be grouted or
vitrified in situ and capped. The most contaminated
areas of onsite sediment will be dredged and disposed
at the Environmental Management Waste Management
Facility (EMWMF), which will be constructed in Bear
Creek Valley.
Signature of the CERCLA ROD for Bethel Valley is a
year or two away; however, the proposed plan is
currently undergoing public review. In the main plant
area of Oak Ridge National Laboratory (Central Bethel
Tennessee

Removed sludge and liquid (nearly 1,900 cubic
meters (2,500 cubic yards)) from aging gunite lowlevel waste tanks
• Removed sludge and liquid from several low-level
waste steel tanks and surface impoundments.
Grouted steel tanks
• Demolished the Waste Evaporation Facility
• Collected contaminated shallow groundwater in
several places, and established plans for future
monitoring

BY 2006 OAK RIDGE NATIONAL LABORATORY
WILL HAVE:
•
•
•
•

Demolished approximately 36 buildings
Filled pipelines and gunite tanks with grout
Collected deep groundwater
Capped several of the large burial grounds in
Melton Valley
• Removed contaminated sediment from the
Intermediate Holding Pond
• Completed decontamination and decommissioning
of the molten salt reactor experiment
5


Valley), contaminated soil will most likely be excavated to a depth of 0.6 meters (two feet) and disposed of in
the EMWMF. Contaminated sediments are assumed to also be excavated and disposed of in the EMWMF in
Bear Creek Valley. Small disposal areas of solid low-level waste will most likely remain in place with clean soil
or caps placed on top. Surface features of contaminated buildings will be demolished and the material disposed
either in the EMWMF or at offsite disposal sites. Subsurface features are expected to be partially
decontaminated and backfilled. Pipelines and tanks may be grouted in place after removal of sludge. Migration
of groundwater most likely will be controlled through interceptor trenches, sumps, and groundwater extraction
wells. For the industrial areas outside the main plant area (East Bethel Valley), contaminated soils, pipelines,
tanks, and subsurface features of buildings are expected to be removed to a depth of three meters (ten feet), if
required. Contamination remaining at the Oak Ridge National Laboratory will include all present burial grounds,
subsurface soil and groundwater, subsurface tanks, piping, and substructures, and some contaminated sediments
in Melton Valley.

East Tennessee Technology Park
Except for the decision to demolish buildings, most
remedial decisions at East Tennessee Technology Park
are in the early planning stages; therefore, the
information provided in this report concerning East
Tennessee Technology Park has greater uncertainty
than the information provided on the Oak Ridge
National Laboratory and theY -12 Plant. To bring East
Tennessee Technology Park to assumed unrestricted
industrial remediation levels, the contaminated soil
would be removed to a depth of three meters (ten feet),
if needed. The contaminated surface and subsurface
features of buildings and facilities, including inactive
infrastructure, may be removed when no longer useable.
Contaminated scrap will be removed. Contaminated
waste, such as that in the burial grounds, may be
removed, treated (if necessary), and disposed at the
EMWMF. Remaining contamination is assumed to
include that in deep soils (greater than three meters (ten
feet)) and in the groundwater.

EAST TENNESSEE TECHNOLOGY PARK
ACCOMPliSHMENTS
• Demolished seven buildings under CERCLA; longterm monitoring required
• Removed sludges from two ponds; future
monitoring required
• Collected and treated shallow groundwater; longterm monitoring required
BY 2006 EAST TENNESSEE TECHNOLOGY
PARK WILL HAVE:
• Demolished approximately 80 buildings
• Excavated all contaminated soil, scrap, and debris
outside of the main fence
• Completed excavation of the Old Contaminated
Burial Ground
• Completed decommissioning of K-31/33 buildings

Y-12 Plant
The first significant remedial decision for Upper East Fork Poplar Creek is one to two years away. A proposed
plan is currently being generated. Plans presented in this report could change. In the main plant area (referred
to as Upper East Fork Poplar Creek), soil and sediment contributing to exceedances of surface water standards,
or future worker risk, are expected to be removed, treated, and disposed in the EMWMF . Some soil may be
treated in place to remove mercury. Scrap will be removed from the site. Contaminated groundwater will be
intercepted at the edge of the plant prior to offsite migration; however, institutional controls are in place and will
remain in place for contaminated groundwater that has already moved offsite in Union Valley. A large process
building, Alpha-4, may be decontaminated for future use as a warehouse.
A remedial decision for part of Bear Creek Valley (the adjacent waste disposal area for Y-12) has just been
signed. However, remaining remedial decisions on the burial grounds are years away. Therefore, parts of the
discussion are still uncertain and subject to change. In Bear Creek Valley, contaminated soil leaching uranium
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to groundwater and ultimately surface water will be
excavated from the Boneyard/Burnyard and disposed in
the EMWMF. Shallow groundwater near the S-3 Ponds
and the burial grounds will be treated through in-situ
reactive trenches. The burial grounds (future decision)
are assumed to be hydraulically isolated through
capping and in-situ treatment. The groundwater that has
migrated past the burial grounds is expected to naturally
attenuate.
Contamination remaining at Y-12 is
expected to include burial grounds, subsurface soil and
groundwater, and subsurface features, such as pipelines.
The EMWMF will be constructed in Bear Creek Valley.
By 2002, this facility will provide a permanent disposal
location for the low-level waste and mixed wastes
generated by CERCLA actions. The 28-hectare (68acre) cell will be constructed above grade with leachate
collection and monitoring systems.

Y-12PLANT
ACCOMPLISHMENTS
•
•

•
•
•
•
•

Removed surface debris from the White Wing
Scrapyard and Kerr Hollow Quarry
Remediated shallow groundwater at S-3 ponds via
in-situ passive treatment; long-term monitoring
required
Removed contaminated soil from the firing range
Treated and capped S-3 ponds, improving the
quality of Bear Creek
Capped large areas of burial grounds under RCRA
Received regulatory approval to construct an onsite
waste disposal facility
Reduced effluent mercury levels to historically low
levels

BY 2006 THE Y-12 PLANT WILL HAVE:

2.0

SITE· WIDE LONG· TERM STEWARDSHIP

•

2.1

Long-Term Stewardship Activities

•
•

Completed excavation of hot spots and residual
capping at the Boneyard/Bumyard
Completed remediation of offsite properties
Removed or treated mercury soil/sediment sites in
the plant

DOE or a successor is expected to maintain ownership
of most of the contaminated areas of the Reservation
once remediation is complete and, therefore, will be responsible for long-term stewardship. To ensure that
unacceptable exposures to residual contamination do not occur, DOE and the other Federal Facility Agreement
parties (i.e., U.S. Environmental Protection Agency (EPA) and Tennessee Department of Environment and
Conservation (TDEC)) are committed to maintaining the needed institutional controls for as long as they are
necessary. This commitment is documented in each ROD where wastes are left in place.
Land use controls include: ( 1) proprietary controls, which rely on property law; (2) governmental controls, which
rely on regulatory authorities; and (3) physical controls. The proprietary controls for the Reservation consist of
restrictions and notices on added deeds or the original acquisition records. Governmental controls use the
regulatory authority of a governmental unit to impose restrictions on citizens or sites under its jurisdiction. DOE
maintains a permit program that controls excavation and penetration activities on the Reservation, including
groundwater use. To provide easy access to this information, notices will be filed on the original acquisition
records and with the City of Oak Ridge and the county or counties wherein the property is located (Anderson
and/or Roane) on the residual contamination locations and associated risk levels. Physical controls will include
limited, passive engineering measures, as well as measures to prevent human intervention, for restricting access.
For the Reservation, this includes access controls (i.e., fences/gates), signs, and personnel training. These land
use controls are not mutually exclusive and will be "layered" to enhance the overall reliability and the health and
safety of the public and the environment.
Access to contamination off the Reservation (Poplar Creek and Clinch River) is currently controlled through deed
restrictions or use advisories and signs that are enforced under an interagency agreement between DOE, EPA,
TDEC, Tennessee Valley Authority, and the U.S. Army Corps of Engineers. The approved ROD for Union
Valley groundwater resulted in license agreements with property owners requiring them to notify DOE of any
changes in surface water or groundwater use.

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DOE and the State of Tennessee developed a unique approach to funding long-term stewardship of the
EMWMF. DOE signed a Consent Order with the State of Tennessee and agreed to deposit $14 million (in $1
million annual installments) into a pooled investment fund established by Tennessee state law (T.C.A. Section
9-4-603). After payment of the final installment, interest for the fund will be used to pay for surveillance and
maintenance of the facility. The fund will terminate upon written agreement that surveillance and maintenance
for the facility are no longer required. Upon termination, the balance of the fund will be returned.
Engineered controls include caps on burial grounds in Melton Valley (part of Oak Ridge National Laboratory),
West Bethel Valley, and Bear Creek Valley. These caps will be maintained, patrolled, and replaced, as needed.
Other engineered controls include the collection and treatment of radioactive groundwater in Melton Valley and
in Bethel Valley. The wastewater treatment plants will be operated and maintained and their equipment will be
replaced periodically, as needed. Ongoing monitoring activities include surface water, groundwater, and
ecological monitoring (bio-survey).
CERCLA five-year reviews will be conducted for all remediated sites where the decision is to leave waste in
place. These reviews evaluate the implementation and effectiveness of the remedial action (including
institutional controls). The five-year reviews will be conducted consistent with the EPA Comprehensive FiveYear Review Guidance (EPA 540R-98-050).
Record-keeping activities will mostly follow current procedures. DOE, in accordance with the Federal Facility
Agreement with EPA and TDEC, requires that information used in decision-making be maintained in the
administrative record. These documents include remedial investigations, feasibility studies, proposed plans, and
RODs. Associated correspondence, data, and some post-ROD information are also included. Most post-ROD
information, including design reports, monitoring plans, monitoring results, and action completion reports, are
kept in a separate system. These information collection systems will be reviewed to determine a way to capture
information relevant to long-term stewardship and to store the information in retrievable form for the long term.

2.2

Long-Term Stewardship Technology Development and Deployment

The role of technology development in long-term stewardship is to develop, demonstrate, and improve
technologies that will ensure the post-closure long-term protection of the environment and the public.
Technologies are needed to enhance the reliability and reduce the cost of planned engineered controls and to
decrease the time for long-term management of residual wastes. The long-term stewardship life-cycle baseline
scope for the OakRidge Reservation Environmental Management program was reviewed to identify key (mission
critical) engineered systems, recurring actions, and high-cost activities. It was determined that key engineered
systems for long-term stewardship include hydraulic isolation ofburied wastes and reactive barriers for treatment
of contaminated surface and groundwater. Major hydraulic isolation components include caps and stormwater
diversion trenches. Major reactive barrier components include reactive media and collection and treatment
trenches. Long-term reliable operation and maintenance of these systems, coupled with periodic replacement,
as needed, is a key component of the long-term stewardship strategy. Assessments to predict the long term
performance of these systems is needed to support the remedy selection process, design effective monitoring
systems, and plan for periodic system replacement. Monitoring of surface water, groundwater, sediments and
biota is a recurring long-term stewardship activity. The projected cost of monitoring is excessive if DOE assumes
that existing technology will be used in the future.
A workshop was held to further examine technology development needs because of the humid eastern
environment (precipitation and hydrology). Principle cap failure modes were identified as bio-intrusion,
subsidence, and erosion. Mechanisms for trench failure (plugging and clogging) were identified as erosion,
siltation, microbial interferences, and chemical reactions. Technology development to extend the life of
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hydraulic isolation by addressing these potential failure modes is needed. The use of remote monitoring
techniques, possibly incorporating satellite technology, was also identified as a technology development need.
The failure of reactive barriers is related to both treatment and hydraulic considerations. Hydraulic-related
factors reduce the permeability in the capture zone and include plugging, bio-fouling, and gas buildup.
Treatment-related factors include media fouling, media life, and remobilization of contaminants. Limited
information is available in these areas, and technology development is needed to sustain reactive barrier
performance over the long-term periods required by stewardship.
Systems need to be developed to reduce long-term stewardship costs. Reliable, remote-time, automated
monitoring systems are available, but technology development of contaminant-specific (radionuclides, organic
chemical and metals) sensors is needed. Technology for in-situ biological monitoring is needed to supplement
and eventually replace traditional analytical monitoring. Innovative groundwater well design and replacement
technology is needed to minimize costs and enhance worker safety.
Technologies are also needed to shorten the period that long-term stewardship is required. This may include
technologies that enhance the natural attenuation processes to accelerate remediation of contaminated soil and
water or technologies that limit the need for hydraulic isolation of buried residual wastes by irreversibly treating
the waste to nontoxic forms. Cost-effective development of in-situ treatment or excavation and ex -situ treatment
of contaminated soils, buried wastes, and contaminated water requiring treatment should also be considered.
2.3

Assumptions and Uncertainties

No final remedial decisions and few interim remedial decisions have been made for the Oak Ridge Reservation.
Only partial remedial decisions in Bear Creek and Melton Valley are anticipated to be made in fiscal year (FY)
2000. Other decisions for most of the Y-12 Plant, all of East Tennessee Technology Park (except building
demolition), and much of Oak Ridge National Laboratory are one to five years away. The ultimate strategies
selected may be different than the assumptions used to perform this analysis.
2.4

Estimated Site-Wide Long-Term Stewardship Costs

Site Long-Term Stewardship Costs (Constant Year 2000 Dollars)
Year(s)

Amount

·.

Year(s)

Amount

Year(s)

Amount

FY 2000

$6,394,000

FY2008

$9,620,000

FY 2036-2040

$40,724,000

FY 2001

$6,394,000

FY 2009

$9,807,000

FY 2041-2045

$50,600,000

FY 2002

$6,394,000

FY 2010

$9,805,000

FY 2046-2050

$79,936,000

FY 2003

$6,356,000

FY 2011-2015

$49,296,000

FY 2051-2055

$85,546,000

FY 2004

$6,470,000

FY 2016-2020

$47,924,000

FY 2056-2060

$40,724,000

FY2005

$7,618,000

FY 2021-2025

$44,312,000

FY 2061-2065

$44,867,000

FY 2006

$7,508,000

FY 2026-2030

$43,526,000

FY 2066-2070

$40,757,000

FY 2007

$7,596,000

FY 2031-2035

$44,264,000

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Long-term stewardship costs include maintaining engineered barriers and monitoring and treating ground and
surface water. DOE assumes, for planning purposes, that each cap will be replaced every 50 years, which results
in a peak in long-term stewardship costs in various years depending on when the caps were installed. Other
engineered controls, such as pumps, piping, trenches, and wells, are replaced at different frequencies. Residual
contamination will be monitored, as necessary, to identify changing conditions and reported at least every five
years during the CERCLA five-year review process. However, monitoring efforts and their associated costs will
decrease over time. Although costs are only estimated to FY 2070, DOE anticipates that long-term stewardship
activities will continue in perpetuity at most areas.
3.0

PORTION OVERVIEW

The Oak Ridge Reservation consists of six "portions" that will require some long-term stewardship activities as
of 2006. For purposes of this report, a "portion" is defined as a geographically contiguous and distinct area
(which may involve residually contaminated facilities, engineered units, soil, groundwater, and/or surface
water/sediment) for which cleanup, disposal, or stabilization will have been completed and long-term stewardship
will be required as of 2006.
Each portion is listed in the table below, with further explanations in Sections 3.1 through 3.6. Each portion,
except for the offsite portion, corresponds to a watershed. The offsite portion includes contaminated surface
water bodies that have left the Reservation (Poplar Creek, Clinch River). Offsite sources of contamination
(Atomic City Auto Parts in Oak Ridge and the David Witherspoon sites in Knoxville) are planned to be
completely restored with no long-term stewardship requirements. For the Oak Ridge Reservation, remedial
decisions are made at the watershed scale. The overall strategy is to group contaminated units by watershed
because: (1) surface water drainage basins result in shared contaminant plumes, and (2) watershed areas have
relatively homogeneous present or potential future land use. The five watersheds include the following:

•
•
•

Bear Creek Valley - includes the Y-12 Plant waste disposal area
Bethel Valley- is the main plant area of the Oak Ridge National Laboratory
Upper East Fork Poplar Creek- primarily includes the Y -12 Plant and Chestnut Ridge to the south
East Tennessee Technology Park - incorporates the entire East Tennessee Technology Park plant site
Melton Valley - includes most of the burial grounds at the Oak Ridge National Laboratory

•

-:

Long• Term. Stewardship Information
·.

Portion

,.

Long-Term Stewardship
Start Year

long-Term Stewardship
End Year

Bear Creek Watershed

2000

In Perpetuity

Bethel Valley Watershed

2000

In Perpetuity

Upper East Fork Poplar Creek Watershed

2000

In Perpetuity

East Tennessee Technology Park Watershed

2000

In Perpetuity

Melton Valley Watershed

2000

In Perpetuity

Offsite

1997

In Perpetuity

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3.1

Bear Creek Watershed Portion

BEAR CREEK WATERSHED PORTION
HIGHLIGHTS

The Bear Creek Watershed Portion is several miles
long within the Bear Creek Valley and extends from
Major Long-Term Stewardship Activities- monitoring
the western end of the Y-12 Plant to the boundary of
and maintaining engineered units; monitoring
groundwater contamination on the west. The Y -12
groundwater; enforcing institutional controls
Portion Size- 1,942 hectares (4,800 acres)
Plant began operations in 1943 to enrich uranium for
Estimated Volume of Residual Contaminants- soil
nuclear weapons as part of the Manhattan Project.
Now, the Y-12 Plant is a major manufacturing,
groundwater unknown; engineered units 2,440,000
development engineering, and technology center
cubic meters (3,191,000 cubic yards)
supporting DOE and other government programs. The
Long-Term Stewardship Start-End Years- 2000-in
auxiliary facilities at theY -12 Plant, including many of
perpetuity
the former waste disposal areas, are in the Bear Creek
Average Annual Long-Term Stewardship Costs FY
watershed. They contain radiologically contaminated
2000-2006- $2,002,000
and nonradiologically contaminated wastes generated
primarily by Y-12 Plant operations. This region is
considered one portion because the multiple disposal areas within Bear Creek Valley are releasing contaminants
into common ground and surface water migration pathways.
None of the disposal areas are currently active and most (burial grounds, hazardous chemical disposal area and
S-3 ponds) have been capped with either a soil cover or engineered multilayer cap under a Resource Conservation
Recovery Act (RCRA) closure program. Two leachate collection systems were installed during capping
operations to collect leachate at potentially contaminated caps. The former waste disposal areas contain large
volumes, greater than 400,000 cubic meters (500,000 cubic yards), of contaminated soil and buried solid waste,
primarily uranium and other metals. Several contaminants have been identified in soil, groundwater, surface
water, and sediment in the Bear Creek watershed. Contaminants include radionuclides and metals in soil and
uranium, nitrates and volatile organic compounds (VOCs) in ground and surface water. Much of the
contamination, particularly in soil and somewhat less so in groundwater, is contained within or near the
boundaries of the waste disposal areas. The highest concentration of contaminants in groundwater occurs at the
former waste disposal areas for the plant, but concentrations causing unacceptable risk have been detected up
to a mile west of the area.
The Bear Creek Valley watershed is divided into three functional areas which will be remediated in accordance
with CERCLA: the Oil Landfarm Area, Burial Grounds, and the S-3 Ponds. The contaminated media for this
portion (soil, groundwater, and engineered units) are discussed in the following paragraphs. Surface water and
sediment will be restored to recreational use, the highest use possible given the size of the stream. Long-term
stewardship activities will not be required for Bear Creek Valley surface water and sediment; therefore, these
media are not discussed. In addition, the EMWMF will be built in Bear Creek Valley. Access to eastern Bear
Creek Valley, which contains the waste disposal areas and the EMWMF, will be restricted and will require longterm stewardship.

3.1.1

Soil

Due to past disposal operations, contaminated soils are associated with three functional areas: the S-3 Ponds,
the Burial Grounds, and the Oil Landfarrn Area. The S-3 Ponds were four unlined ponds used for industrial
waste treatment and contain contaminated soils underneath the closed ponds. The Burial Grounds consist of
trenches used for disposal of liquid and solid wastes and contain contaminated soils between the trenches. The
contaminated soils under the S-3 Ponds and between the trenches in the Burial Grounds will be discussed in
Section 3.1.3 on engineered units.
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11


~ Groundwater Contamination

~ Soil Contamination

0

1

2

CREEK

Bear Creek Watershed

The Oil Landfarm Area includes the Oil Landfarm and the Boneyard/Burnyard. The Oil Landfarm is a former
land-farming plot used for biological degradation of approximately 4,000 cubic meters (5,000 cubic yards) of
industrial waste oil and machine coolants between 1973 and 1982. The Boneyard/Burnyard consists of three
areas: Boneyard (used for contaminated, noncombustible material disposal), Burnyard (used for contaminated,
combustible material disposal), and the Hazardous Chemical Disposal Area.
Soils in the Oil Landfarm Area are contaminated with uranium, polychlorinated biphenyls (PCBs), metals, and
other radionuclides. Highly contaminated soil (i.e., hot spots) will be excavated from the Boneyard/Burnyard
and disposed in the EMWMF. Residual materials that pose lower long-term risk will be contained onsite through
appropriate hydraulic isolation measures, including soil covers or caps. These are primarily uranium and organic
chemical contaminated soils. Approximately 20 hectares (40 acres) of contaminated soil will remain. The
contaminated soil could be as deep as six meters (20 feet) or as shallow as two meters (six feet). At an average
of four meters (12 feet), the volume is estimated to be 15,000 cubic meters (19,000 cubic yards). By 2006, soil
remediation will be completed in the Oil Landfarm Area.

Tennessee

12

Oak Ridge Reset·vation

Soil Long-Term Stewardship Activities
To ensure that unacceptable exposures to residual contamination in Bear Creek Valley do not occur, DOE will
maintain necessary land use restrictions and governmental controls. The contaminated area of Bear Creek Valley
will be designated for controlled industrial use (restrictions below two feet), with areas of restricted waste
disposal use, including the residual soil contamination in all three functional areas. Requirements for
institutional controls in Bear Creek were documented in the first ROD, and more details will be provided in a
future land use control implementation plan. As other RODs are signed, additional institutional controls may
be added. Institutional controls, such as restricting access and prohibiting soil excavation, have been in place
since the waste has been in place but will begin in 2000 under CERCLA now that a significant ROD has been
signed. These controls will be implemented through a permit program maintained by DOE. In addition, residual
contamination will be monitored as often as necessary to identify changing conditions and reported at least every
five years in accordance with the CERCLA five-year review process. Monitoring efforts will decrease over time
as site conditions stabilize and less frequent monitoring is required, resulting in long-term stewardship cost
decreases over time. However, the cap planned for the soil in the Boneyard/Burnyard is assumed to be replaced
every 50 years, as needed.

3.1.2

Groundwater

The groundwater in Bear Creek Valley is contaminated with uranium, nitrates, PCBs, and volatile organic
compounds (i.e., trichloroethene and degradation products) released from historic waste disposal operations. A
relatively continuous zone of groundwater contamination exists throughout the three functional areas: the Burial
Grounds, Oil Landfarm, and S-3 Ponds areas. The contaminated groundwater plume is approximately 40 hectares
(100 acres) and extends from all waste disposal units down the valley to the west. The plume is not expected
to reach beyond the west end of the Burial Grounds.
The groundwater flow is governed by the valley's geology. The rock formations are extensively fractured
(karstified), which substantially increases the permeability. The fracture width generally decreases with depth,
restricting the depth of active groundwater circulation. However, the shallow interval (top 30 meters (100 feet))
is well connected and, therefore, rapidly transports water to Bear Creek. Most groundwater flow occurs in this
interval during and immediately following precipitation.
The final groundwater remediation strategy has been deferred from all negotiations. There has been significant
disagreement on the strategy, so the Federal Facility Agreement parties agreed to implement actions to prevent
source contaminant releases and monitor the effects on groundwater before negotiating a final groundwater
strategy. The groundwater contamination conditions are complex since the geology is karstic and contaminant
flow paths are difficult to track. The sources of groundwater contamination are well identified, but contamination
is deep, and secondary sources (free product) have been found hundreds of feet deep. For cost estimating
purposes, DOE is assuming that remediation will be by natural attenuation with no active restoration and
installing of hydraulic barriers to isolate contaminant sources (i.e., the Burial Grounds).

Groundwater Long-Term Stewardship Activities
Based on the assumed remedial strategy, DOE will monitor the groundwater to ensure that the remedy is effective
and contaminants are being attenuated as expected. DOE assumes, for costing purposes, that any necessary
groundwater interception/treatment trenches and wells will be replaced at 50-year intervals. To ensure that
unacceptable exposures to residual contamination do not occur, DOE would need to maintain necessary land use
restrictions under this strategy, such as prohibiting any use of onsite groundwater. Long-term stewardship
activities will be described in a future decision, which is expected well after 2006 (assumed to be no earlier than
Tennessee

13

National Defense Authm·ization Act (NDAA) Long· Term Stewardship Report

2010). Such a strategy allows for evaluation of the impact of previous actions on the groundwater quality.

3.1.3

Engineered Units

This portion contains three engineered units: the Bear Creek Burial Grounds, S-3 Ponds, and the EMWMF,
which, together, occupy a 56-hectare (138-acre) area. The Bear Creek Burial Grounds and S-3 Ponds were used
for historical disposal of Y -12 Plant waste. The EMWMF will be used for disposal of Oak Ridge Reservation
CERCLA wastes.
The Bear Creek Burial Grounds are approximately three kilometers (two miles) west of the Y -12 Plant and were
primarily used to dispose of uranium turnings and industrial wastes contaminated with uranium from nuclear
weapons production. The burial grounds, which operated from approximately 1955 to 1993, consist of several
principal waste disposal units, each with a series of trenches. Since 1989, several waste disposal units have been
closed with a RCRA-approved cap. The remaining burial grounds are assumed to be contained in place. The
material eventually capped in place would include uranium chips in solvents, trash and debris contaminated with
radioactivity, waste oils, beryllium metals, and unstable materials, such as picric acid. The volume of soil and
debris remaining in place is estimated at 917,000 cubic meters (1.2 million cubic yards).
The S-3 Ponds were four unlined ponds located adjacent to the west end of the Y-12 Plant. Constructed in 1951,
these impoundments covered approximately 122 by 122 meters (400 by 400 feet). The ponds were approximately
five meters (17 feet) deep and, while in operation, each pond had a storage capacity of 9,464 cubic meters
(12,378 cubic yards). The ponds were used to dispose of liquid wastes and sludge, including nitric acid and
uranium, from Y-12 Plant operations. In-situ treatment of wastewater in the S-3 Ponds consisted of neutralization
and biodenitrification processes that began in 1983 and continued until September 1984. After biodenitrification,
the ponds' contents were allowed to settle and form a sludge layer ranging from 0.6-to-1.5 meters (two-to-five
feet) thick. The volume of neutralized sediment and underlying contaminated soil above the water table is
estimated at 23,000 cubic meters (30,000 cubic yards). In 1988, the S-3 Ponds were closed, in accordance with
RCRA, by placing a multilayer cap over the area and covering it with asphalt to create a parking lot. While the
source has been contained, remediation efforts are underway to control the migration of contaminated
groundwater from past pond releases. These efforts will be completed before 2006. Institutional controls are
already in place to maintain the cap and prevent access to residual contamination.
The EMWMF is being constructed for disposal of mixed (hazardous and low-level) wastes generated during
CERCLA remediation of the Oak Ridge Reservation. The EMWMF, with two additional expansions, is
anticipated to contain 1,500,000 cubic meters (2,000,000 cubic yards) of waste when filled and closed. A wide
variety of materials is expected to be placed in the cell, including radioactively contaminated demolition debris;
radioactively contaminated soil; soils after treatment for mercury removal; lightly contaminated trash; personal
protective equipment; and materials from East Tennessee Technology Park burial grounds, which would include
uranium, thorium, beryllium, other metals, and organic contaminated soil and debris. A Waste Acceptance
Criteria Attainment Plan is under development that would control the types of contamination that can be
disposed. For instance, RCRA material must be treated first; and highly mobile contaminants, such as
Technetium-99, are limited. The EMWMF, estimated to cover 28 hectares (68 acres), will contain a bottom
barrier, a leachate collection system, and an intruder barrier final cap. The EMWMF will be accepting waste by
2002 and is not anticipated to be closed until around 2015. TDEC is planning on administering the long-term
surveillance and monitoring program through a trust fund that has been set up.

Engineered Units Long-Term Stewardship Activities
Long-term stewardship activities, such as monitoring, maintenance, replacement, and surveillance, will be
Tennessee

14


required to ensure that the engineered controls remain protective of human health and the environment. Regular
monitoring will occur in accordance with agreements reached during closure. Effectiveness of the remedial
actions and these long-term stewardship activities will be validated and verified through the CERCLA five-year
review process. The engineered caps and other items are expected to be replaced as needed. Institutional
controls, such as a permit program requiring DOE approval before any penetration in the area, have been in place
since the waste has been in place, but CERCLA will also require these controls once a ROD is signed. The
EMWMF will be fenced with access controls.
DOE is committed to maintaining necessary land use controls to ensure that unacceptable exposures to residual
contamination do not occur. Specific land use control requirements for Bear Creek were incorporated in the first
ROD, and the details will be described in a land use control implementation plan. Future Bear Creek Valley
RODs may augment the land use controls. The areas of Bear Creek Valley that are contaminated will be
designated for controlled industrial (restrictions below 0.6 meter (two feet)), with areas of restricted waste
disposal use for the Burial Grounds and the EMWMF.

3.1.4

Estimated Long-Term Stewardship Costs for Bear Creek Watershed

Long-term stewardship activities for the Bear Creek Watershed Portion are anticipated to include monitoring and
maintaining engineered units, monitoring groundwater, and enforcing institutional controls. For cost estimating
purposes, DOE is assuming that groundwater remediation will be by natural attenuation with no active restoration
and installing of hydraulic barriers to isolate contaminant sources (i.e., the Burial Grounds). Also, for cost
estimating purposes, DOE assumes that engineered caps, trenches, and groundwater wells will be replaced at 50year intervals, resulting in peaks in long-term stewardship costs around the years 2040-2050 for existing caps
and 2060 for new caps. Regular monitoring will occur in accordance with agreements reached during closure.
Effectiveness of the remedial actions and long-term stewardship activities will be validated and verified through
the CERCLA five-year review process. However, monitoring efforts are expected to decrease over time as
environmental conditions stabilize, resulting in decreasing cost over time. Although costs are reported until FY
2070, long-term stewardship is anticipated to be required beyond FY 2070.
Currently, the environmental remediation project costs for the Reservation are not estimated by portion
(watersheds), but rather, by three major areas (Oak Ridge National Laboratory, Y-12 Plant, and East Tennessee
Technology Park). The estimated long-term stewardship costs for the Bear Creek Watershed Portion are a
percentage of the Y-12 Plant's long-term stewardship costs.
Long-Term Stewardship Costs (Constant Year Dollars)
F¥2000F¥2010

F¥2011F¥2020

F¥2021F¥2030

F¥2031·
F¥2040

F¥2041F¥2050

$22,006,000

$18,101,000

$12,469,000

$10,728,000

$29,050,000

3.2

F¥2051F¥2060
$8,198,000

F¥2061F¥2070

Estimated
Total

$11,359,000

$111,911,000

Bethel Valley Watershed Portion

This portion encompasses a 702-hectare (1,734-acre) area of Bethel Valley in the southwest region of the Oak
Ridge Reservation and contains the main plant area for the Oak Ridge National Laboratory. The Bethel Valley
portion is a contiguous area of contamination that lies within the valley. Within Bethel Valley, there are three
areas: East Bethel Valley, Central Bethel Valley, and West Bethel Valley.
•

East Bethel Valley is the Laboratory maintenance area, which contains a single facility and a volatile
organic compound (VOC) contaminated groundwater plume. There are no contaminated soil, surface

Tennessee

15


water, sediment, or engineered units.

•

Central Bethel Valley includes the Laboratory
area, which contains active and inactive
buildings, former burial grounds, underground
liquid low level waste tanks, underground
pipelines, and associated underground and
above-ground utilities. Contaminated soil,
surface water, sediment, and groundwater have
resulted from Laboratory activities. The most
significant release offsite results from
subsurface spills of strontium in the Laboratory
area, which have contaminated groundwater
and surface water. Strontium contamination
resulting from Bethel Valley flows offsite
through Melton Valley and can be detected in
the Clinch River.

BETHEL VALLEY WATERSHED PORTION
HIGHLIGHTS
Major Long-Term Stewardship Activities- monitoring

Portion Size- 702 hectares (1,734 acres)
*Estimated Volume of Residual Contaminants - soil
765,000 cubic meters (1 million cubic yards);
groundwater unknown; engineered units 115,000 cubic
meters (150,000 cubic yards); facilities unknown
perpetuity
2000-2006- $1,124,000
residual contaminants.

West Bethel Valley contains a burial ground area. Groundwater and soil are contaminated as a result
of disposal activities in this area of the valley.
These areas will be remediated and will be subject to long-term stewardship in accordance with CERCLA. The
assumptions below are from a proposed plan and could be modified when decisions are made in the next year.
The contaminated media for this portion (soil, groundwater, engineered units, facilities) are discussed in the
following paragraphs. Surface water and sediments would be restored to recreational use, the highest use
possible given the size of the streams. Contaminated sediments would be excavated and disposed in the
EMWMF. No institutional controls or other long-term stewardship activities would be required in Bethel Valley
surface water and sediment once established goals have been met.

3.2.1

Soil

Contaminated soil through Central Bethel Valley releases contaminants into common ground and surface water
paths. Bethel Valley is underlain by bedrock which has innumerable small-scale folds, faults, and fractures that
play a major role in groundwater flow. The bedrock is covered with a mantle of soils that tend to retain the
fractures and bedding planes of the parent bedrock but have a higher porosity and permeability than the parent
rock. The primary contaminants of concern in the soil are cesium-137, strontium-90, and cobalt-60.

•

East Bethel Valley has no soils that are known to be significantly contaminated.

•

Central Bethel Valley has soil that is primarily contaminated with radionuclides (e.g., cesium-137),
although there is also some mercury contamination. The surface soil is contaminated as a result of spills,
fallout, and runoff. Contamination leaked out of Oak Ridge National Laboratory buildings as a result
of pipeline leaks and breaks, tank leaks, migration of surface contamination through the soil, and
movement of contaminated groundwater through pipelines and natural channels. An extensive amount,
approximately 765,000 cubic meters (one million cubic yards), of contaminated soil will remain in
Central Bethel Valley because remediation efforts will focus only on the top 0.6 meters (two feet).
Although considerable sampling has occurred, there is still a high degree of uncertainty on the extent and
depth of contamination.

Tennessee

16


ORNL

ESSS::J
-

0

Soil Contamination

Engineered Units

1

2

Miles

Bethel Valley Watershed
•

West Bethel Valley soils are associated with the burial ground and will be addressed as part of the
engineered unit.

The proposed remediation strategy is to generally remove (down to 0.6 meters (two feet)) contamination in the
surface soil and dispose of the soil in the EMWMF in Bear Creek Valley. Contamination in subsurface soil, such
as in secondarily contaminated areas along seepage discharge routes from source units, will remain in place
unless significantly contributing to groundwater contamination, in which case it will be removed. In general,
high levels of cesium-137 contamination will remain, although strontium-90 levels will be reduced. However,
the soil remediation levels are dependent on the final land use identified for the area. The Oak Ridge National
Laboratory main plant area (Central Bethel Valley) is assumed to be remediated to a controlled industrial land
use (clean to a depth of0.6 meters (two feet)). The remainder of the developed area outside the main plant area
(East Bethel Valley) is assumed to be remediated to unrestricted industrial land use (clean to a depth of three
meters (ten feet)). The burial grounds/landfill in West Bethel Valley are assumed to be a waste management area
(although some limited surface use may be appropriate). The remainder of the watershed (which has only small
isolated areas of contamination and no current industrial use) will be remediated to unrestricted land use in West
Bethel Valley. By 2006, soil remediation is anticipated to be only partially complete.

Tennessee

17


In Central Bethel Valley, 0.6 meters (two feet) of clean surface soil would prevent access to contamination. DOE
will maintain a permit program to control unauthorized penetration into residual contamination. Likewise, three
meters (ten feet) of clean soil in East Bethel Valley and a cap on the burial ground in West Bethel Valley with
the same permit program will control access in those areas. DOE is committed to maintaining the necessary land
use controls, including institutional controls, for as long as they are necessary to ensure that unacceptable
exposures to residual contamination do not occur. Specific requirements for institutional controls in Bethel
Valley will be documented in the ROD; additional detail will be provided in a future land use control
implementation plan to be developed after the watershed ROD is signed. The land use controls will include a
DOE-administered permit program that will require the appropriate safeguards and precautions whenever
disturbance of the remediated area is needed. The controls will also include fences and signs, primarily in
Central Bethel Valley. Regular monitoring will occur in accordance with agreements reached during closure.
the CERCLA five-year review process.
If selected, the engineered controls, such as multilayer caps or soil covers, will require periodic surveillance and
maintenance. DOE assumes, for planning purposes, that each cap will be replaced every 50 years.

3.2.2

Groundwater

The groundwater in Bethel Valley is contaminated with numerous radionuclides and volatile organic compounds.
A relatively continuous zone of groundwater contamination, 17 hectares (42 acres), exists through the plant area
in Central Bethel Valley. Contaminated groundwater originates from source areas and typically follows shallow
pathways to nearby surface water bodies and basement sumps. The groundwater contamination migrates through
the subsurface along natural channels, as well as via pipelines and their bedding material. Groundwater is not
expected to migrate along deep pathways outside the current zone of groundwater contamination. Some early
actions to control one of the most contaminated areas have resulted in decreased contamination of nearby surface
water bodies. Collected groundwater from early actions is currently treated at a wastewater process treatment
plant onsite. The proposed remedial action would continue these activities and would add deep groundwater
extraction in Central Bethel Valley.
East Bethel Valley contains a plume of volatile organic compounds thought to be due to a spill in the
maintenance area. To date, neither the extent of contamination nor the spill source have been identified.
The proposed action is enhanced in-situ biodegradation.
Central Bethel Valley groundwater is contaminated primarily from subsurface pipeline leaks. Additional
contamination has resulted from the migration of contaminants from tank, building, and impoundment
leaks, as well as contaminated soil. The contamination is primarily radionuclides (strontium-90 and
tritium) volatile organic compounds, and some metals. However, the groundwater system is not clearly
understood. There are multiple sources and complex flow paths. Multiple groundwater collection
activities are proposed for this contamination.
West Bethel Valley groundwater is contaminated primarily with strontium-90 as a result of materials in
the burial ground. Groundwater contamination is reasonably well understood because there is only a
single, well identified source (burial ground) and a fairly old and stable plume of strontium
contamination. Monitoring is all that is proposed for this plume.
As mentioned above, the contaminated groundwater conditions are complex.
Tennessee

Consequently, the final
18


groundwater remediation strategy has been deferred by the Federal Facility Agreement parties. For costestimating purposes, DOE assumes that the actions mentioned above are implemented through interim decisions,
but no active restoration will occur. The completed source control actions (i.e., tank sludge removal, pond sludge
removal) and those proposed in the next remedy (deep soil removal, pipeline grouting) are expected to reduce
contamination concentrations and flux in the groundwater but not restore the groundwater to drinking water
standards. In-situ biodegradation in East Bethel Valley and deep groundwater extraction in Central Bethel Valley
will also reduce contaminant levels. The final remedial decision on groundwater will not be made until source
control actions are complete and their effectiveness monitored. A more informed decision for final groundwater
remediation can be made sometime after 2006.

DOE will monitor groundwater in accordance with interim decisions. Effectiveness of the remedial actions and
long-term stewardship activities will be validated and verified through the CERCLA five-year review process.
DOE assumes, for costing purposes, that any necessary groundwater interception/treatment trenches and wells
will be replaced at 50-year intervals. To ensure that unacceptable exposures to residual contamination do not
occur, DOE will maintain land use restrictions, including institutional controls, for as long as they are necessary.
Specific requirements for institutional controls in Bethel Valley will be documented in the ROD, with the details
to be presented in a future land use control implementation plan to be developed after the watershed ROD is
signed. The land use controls will include a DOE-administered permit program that will require the appropriate
safeguards and precautions to prevent inappropriate use of the groundwater.
The engineered controls for groundwater contamination include pump and treat and shallow collection in existing
sumps for groundwater contaminated with radionuclides. Groundwater collected will be treated at one or more
water treatment plants prior to release. Each of the engineered controls will receive periodic surveillance and
maintenance.

3.2.3

Engineered Units

The West and Central areas of Bethel Valley have 61 multiple and low-level waste engineered units (five burial
grounds/landfills, 13 gunite tanks, and 43 steel tanks), which occupy three hectares (eight acres). All of these
units have released, or have the potential to release, contaminants into the environment. Depending on their
location, these units contribute to commingled groundwater contamination. East Bethel Valley does not contain
any engineered units. The burial grounds in West Bethel Valley and Central Bethel Valley contain a total of
109,000 cubic meters (142,000 cubic yards) of residual contamination.
•

West Bethel Valley has a burial ground area that contains demolition debris contaminated with
radionuclides, fly ash, contaminated soil, and alpha waste. Procedures were to bury waste in unlined
trenches and cover with soil. Considerable radioactive (alpha) contaminants from other sites were buried
in West Bethel Valley. Most of this material was covered with concrete. As discussed previously,
releases of strontium to the groundwater have occurred. The proposed remediation strategy is to cap the
material in place. Remediation of the burial grounds is not anticipated until around 2006.

•

Central Bethel Valley contains a minor burial ground and some landfills, gunite and steel underground
tanks, and pipelines.
The burial ground consists of unlined trenches covered by soil, and covered landfills. These are
some of the older burial areas at the Oak Ridge National Laboratory and, therefore, portions
have been removed. There is slight contamination from minor quantities of radioactive waste

Tennessee

19

National Defense Authorization Act {NDAA) Long-Term Stewardship Heport

(low-level waste) under the burial area, but it is not impacting nearby surface water. The
estimated volume of contamination in Central Bethel Valley burial ground/landfills is 17,200
cubic meters (22,450 cubic yards). The proposed remedial action is to cover and cap the burial
sites in place; however, the State of Tennessee prefers that the waste eventually be removed.
Regardless, the burial areas will not be remediated until after 2006.
Thirteen gunite tanks (gunite is a concrete, sand, and water mixture that was sprayed over a wire
mesh and steel reinforcing frame) and 43 steel tanks (totaling 5,800 cubic meters (7,600 cubic
yards) capacity) were used in Bethel Valley to store wastewater and provide settling and storage
capacity for low-level waste. These tanks have been sources of groundwater contamination,
typically as a result of line leaks outside of the tanks. Groundwater underneath the tanks is
contaminated with strontium and uranium. Removal of99 percent of the sludge and liquid waste
and 95 percent of the contamination remaining in the tanks was completed in November 2000.
The sludge and liquids were transferred to new stainless steel tanks. By 2006, the shells (and
residual sludge in the tanks) will be filled with grout. Slight radioactive contamination of the
shells will exist. Eventually, the waste will be treated onsite and shipped to the Waste Isolation
Pilot Plant in New Mexico for disposal.
Roughly 17,000 meters (56,000 feet) of inactive pipelines exist in Central Bethel Valley. These
pipelines were used to transport process wastes from buildings to waste treatment facilities.
Transported waste included radionuclides, organics, and transuranic waste. As these pipelines
aged, numerous leaks occurred. The proposed remedial action is to flush out the materials in
the pipelines and then fill them with grout in place. Residual contamination is expected to be
minimal, although residuals from historic releases will exist in the surrounding soils.

The required long-term stewardship activities will include monitoring and maintaining engineered barriers and
enforcing institutional controls. Each of the engineered controls (i.e., multilayer caps) will require periodic
surveillance and maintenance. DOE assumes, for planning purposes, that caps will be replaced every 50 years.
DOE is committed to maintaining the necessary land use controls, including institutional controls, for as long
as they are necessary to ensure that unacceptable exposures to residual contamination do not occur. Specific
requirements for Bethel Valley will be documented in the ROD, with the details of land use controls to be
developed in a future land use control implementation plan. Land use controls include a DOE-administered
permit program that requires the appropriate safeguards and precautions whenever disturbance of a remediated
area is needed. Regular monitoring will occur in accordance with agreements reached during closure.
the CERCLA five-year review process.

3.2.4

Facilities

Approximately 57 inactive buildings and other structures, generally of concrete block construction, are
contaminated due to past operations. These buildings occupy an estimated two hectares (five acres) and are being
remediated in accordance with CERCLA regulations. All but one of the inactive buildings are located in Central
Bethel Valley. More buildings will become inactive in the future. Some buildings contain reactors, hot cells,
and other areas that are highly contaminated with radioactive material. Activities in the experimental reactors
and in the laboratories contributed to contaminated walls, floors, and equipment.
The proposed remedy is decontamination and demolition of the building surface features. The contaminated
Tennessee

20


material will be disposed either in the EMWMF or offsite. Some of the buildings have below-ground basements.
These subsurface structures will be remediated by removal of loose contamination, followed by backfilling. For
industrial areas outside the main plant area (East Bethel Valley), contaminated subsurface features of buildings
will be removed to a depth of three meters (ten feet), if required. The demolition work at the Oak Ridge National
Laboratory will be underway but not completed by 2006.
The only residual surface contamination would be at the Graphite Reactor.
The Graphite Reactor will not be removed because it is designated as a
National Historical Landmark. The Graphite Reactor operated untill963.
At shutdown, boron-steel rods were inserted into the roughly 30-by-46
meter ( 100-by-150 foot) reactor to ensure the reactor would not go critical.
The fuel was removed in 1966. A negative pressure is maintained
throughout the reactor and the exhaust is vented. Residual fixed (painted
or grouted) contamination remains, as listed in the following table
(Graphite Reactor Contaminants of Concern). However, the volume of
residual fixed contamination is minor. Thin layers of contamination that
are under paint could be anywhere, and, since the contamination is fixed in
place, there are no specific target remediation levels. The additional
CERCLA action is to remove the need for permanent negative pressure by
grouting the reactor core.

Graphite Reactor

Contaminants of Concern
Plutonium-239

Strontium-90

Carbon-14

Asbestos

Iron-55

Lead

Cesium-137

Facilities Long-Term Stewardship Activities
Upon completion of the demolition activities, land use restrictions will be required. The permit program used
to prevent access to subsurface (greater than 0.6 meters (two feet)) soil will be used to prevent access to slightly
contaminated subsurface structures. The only facility requiring unique institutional controls will be the Graphite
Reactor. The Graphite Reactor will continue to be an historic monument and open to the public for tours. DOE
Orders for levels of public exposure and maintenance/monitoring of the facility will continue to be followed.
To ensure that unacceptable exposure to residual subsurface contamination does not occur, DOE will maintain
necessary land use restrictions. Specific requirements for Bethel Valley will be documented in the ROD, with
details specified in a future land use control implementation plan to be developed after the watershed ROD is
signed. The land use controls will include a DOE-administered permit program that requires appropriate
safeguards and precautions whenever disturbance of a remediated area is needed. Controls also may include
fences and signs for residual subsurface contamination. Regular monitoring will occur in accordance with
agreements reached during closure. Effectiveness of the remedial actions and long-term stewardship activities
will be validated and verified through the CERCLA five-year review process.

3.2.5

Estimated Long-Term Stewardship Costs for Bethel Valley Watershed

DOE anticipates that long-term stewardship activities for the Bethel Valley Watershed Portion will include
monitoring and maintaining engineered units, monitoring groundwater, and enforcing institutional controls. For
cost-estimating purposes, DOE assumes that the groundwater remedial actions are implemented through interim
decisions, but no active restoration will occur. DOE assumes, for planning purposes, that engineered caps will
be replaced every 50 years, resulting in a peak in long-term stewardship costs in the years 2051-2055. Regular
monitoring will occur in accordance with agreements reached in the ROD. Monitoring efforts and costs are
expected to decrease over time as site conditions stabilize. Although costs are only estimated to FY 2070, DOE
anticipates that long-term stewardship activities will be required in perpetuity at most areas.

Tennessee

21

National Defense Authorization Act (NDAA) Long-Term Steardship Report

(watersheds), but rather, by three major areas (Oak Ridge National Laboratory, Y -12 Plant, and East Tennessee
Technology Park). The estimated long-term stewardship costs for the Bethel Valley Watershed Portion is based
on a percentage of the Oak Ridge National Laboratory's long-term stewardship costs.
Long-Term Stewardship Costs (Constant Year200f! Dollan)
FY2000~

FY2010

FY20IIFY2()20

FY2021•
FY2030

$17,308,000

$28,825,000

$29,704,000

3.3

FY2031•FY
2040
$30,005,000

FY2(J41 ~·
FY2050.

FY205[fi'Yi061J<

$34,561,000

$53,252,000

·

...

FY206J;;<.·.
Estimated
.. FY207.0. •.•· .·· Total
$29,713,000

$223,368,000

Upper East Fork Poplar Creek Watershed Portion

This portion includes theY -12 Plant and the ridge south
UPPER EAST FORK POPLAR CREEK
of the Plant. The Y-12 Plant encompasses about 300
WATERSHED PORTION HIGHLIGHTS
hectares (800 acres) near the northeast corner of the
Oak Ridge Reservation. It is separated from the City of
Major Long-Term Stewardship Activities - monitoring
Oak Ridge by a wooded ridge. The Y-12 Plant began
operations in 1943 to enrich uranium and produce
Portion Size- 300 hectares (800 acres)
nuclear weapons as part ofthe Manhattan Project. Now
*Estimated Volume of Residual Contaminants - soil
the Y-12 Plant is a major manufacturing, development
unknown; groundwater unknown; engineered units
engineering, and technology center supporting DOE and
250,000 cubic meters (330,000 cubic yards)
other energy agency programs. Historic operations at
the Y -12 Plant resulted in contaminated soil,
perpetuity
groundwater, surface water, and sediment.
The
predominant contaminants of concern are mercury,
2000-2006- $1,001,000
PCBs, and uranium. This region is considered one
portion because multiple areas within the plant are
releasing contaminants into common ground and
surface water migration pathways. Releases from
contaminated soil and sediments to ground and surface water have resulted in offsite contamination (e.g., mercury
in surface waters and VOCs in groundwater).
The Y -12 plant has an ongoing Defense Program mission that is assumed to continue for the foreseeable future.
Therefore, the projected future land use for the Y-12 Plant site will be controlled industrial use (restrictions
below 0.6 meters (two feet)) in the West/South Central Y-12 Plant area (Defense Program) and unrestricted
industrial use (restrictions below three meters (ten feet)) in the East/North Central Y -12 Plant area. These future
anticipated land uses are based on DOE's estimates of which portion of the plant will no longer be needed to
fulfill the government's mission. Access to the controlled industrial area will be restricted to workers and
controlled by signs and fences. Chestnut Ridge, to the south of the Plant, contains several small disposal areas
and large industrial waste landfills. The remediation program anticipates leaving some of the small units in place
because the operating Plant will continue to use the adjacent landfills. Eventually (well after 2006), DOE will
close the landfills in place under state regulations.
Each of the contaminated media (soil and groundwater) is discussed separately in the following sections. The
groundwater discussion includes the Union Valley plume which is moving offsite, east of the Y -12 Plant. A
mercury-contaminated building within theY -12 Plant, Alpha 4, will be completely decontaminated and will not
require long-term stewardship activities. Therefore, facilities are not discussed in this section. Surface water
and sediments will be restored to their highest beneficial and classified use, and no institutional controls will be
required. Therefore, surface water and sediment are not discussed in this section. The engineered units currently
Tennessee

22


D

Sediment
Disposal
Basin

FCAP

~

~ Groundwater Contamination

ISSSSJ

Soil Contamination
0.25

0.5

Miles

Upper East Fork Poplar Creek Watershed

in the remediation program scope are associated with the Chestnut Ridge area.

3.3.1

Soil

Although soil contamination, 136 hectares (336 acres), is spread throughout the Y-12 Plant, contamination is
most extensive in the western part of theY -12 Plant. Due to past operations, the predominant contaminants of
concern are uranium and mercury, although other contaminants, such as PCBs, cesium, beryllium, and radium,
are present.
Early actions have been completed to excavate contaminated soils from the Y -12 Firing Range and Basin 9822.
However, final decisions on the remediation strategy for soil are expected in late 2001 or 2002. The anticipated
remedial action is the removal, treatment, and disposal (in the EMWMF) of soil contributing to future worker
(industrial) risk. Some soil will be treated in place to remove mercury. Scrap will be removed from the site. By
2006, approximately two-thirds of the soil will be remediated. It is expected that uranium-238 and mercury in
surface soils will remain at levels acceptable for industrial use. Mercury will remain below 0.6 meters (two feet),
especially under buildings. The residual contamination will be scattered and an approximation of volume is not
possible.

Tennessee

23

National Defense Authorization Act (NDAA) Long-Term Stewards hill Report

Due to the residual contamination, long-term stewardship activities, such as access restrictions, institutional
controls, and monitoring, will be required. Specific requirements for the Upper East Fork Poplar Creek portion
will be documented in the ROD, with the details developed in a future land use control implementation plan to
be developed after the CERCLA ROD is signed. The Y-12 Plant has an ongoing Defense Program mission that
is assumed to continue for the foreseeable future. Access to the controlled industrial area is assumed to be
restricted to workers through signs and fences. The excavation of soils will be limited to a depth of 0.6 meters
(two feet) within the controlled area and to a depth of three meters (ten feet) in the unrestricted industrial area.
These controls will be implemented through a permit program maintained by DOE. Regular monitoring will
occur in accordance with agreements reached during closure. Effectiveness of the remedial actions and long-term
stewardship activities will be validated and verified through the CERCLA five-year review process. Monitoring
efforts will decrease over time as site conditions stabilize.

3.3.2

Groundwater

Groundwater contamination caused by multiple historic releases associated with the Y-12 Plant, extends over
the southern half of the Upper East Fork Poplar Creek Portion, 162 hectares (400 acres). The contaminated area,
consisting of a series of interconnected carbon tetrachloride groundwater plumes under the southern portion of
the Y-12 Plant, extends offsite into Union Valley. Shallow (less than 30 meters (100 feet) deep) and deeper
(greater than 30 meters (100 feet) deep) aquifers contain contaminants; however, most contaminants are
transported through the shallow aquifer. The design of a groundwater extraction and treatment system to treat
the contaminated groundwater plume that extends offsite is in progress as part of an interim action. By 2006,
offsite migration into West Union Valley will have been halted by the East End Volatile Organic Compound
Plume pump-and-treat activity. However, the predominant contaminants of concern, carbon tetrachloride,
trichloroethylene (TCE), tetrachloroethylene (PCE), 1-2 dichloroethylene (DCE), arsenic, and nitrate, will remain
onsite. Data indicate that dense non-aqueous phase liquids (DNAPLs), such as organic solvents, may also be
present.
The final groundwater remediation has been deferred from all negotiations. There has been significant
disagreement on the strategy, so the Federal Facility Agreement parties agreed to implement actions to prevent
source contaminant releases and monitor the effects on groundwater before negotiating a final groundwater
strategy. The groundwater contamination conditions are complex since the geology is karstic (fractures) and flow
paths of contaminants are difficult to track. The sources of groundwater contamination are not well identified,
contamination is deep, and secondary sources (free products) are assumed to be found hundreds of feet deep.
For cost-estimating purposes, DOE assumes that, beyond 2015, a passive groundwater containment system on
the eastern end of the Y-12 Plant will be the only groundwater action. The final remedial decision on
groundwater will not be made until well after 2006 (assumed to be no earlier than 2010); however, interim
remedial decisions to extract groundwater at the east end of the Plant are scheduled to begin this year (2000).

Based on the interim action and the proposed remedial action, the required long-term stewardship activities will
include surveillance and maintenance of the engineered controls, groundwater monitoring, and enforcing of
institutional controls. Upper East Fork Poplar Creek engineered controls include extraction and ex-situ treatment
of the East End groundwater plume. The groundwater monitoring wells will be flushed every 10 years and
replaced at 50-year intervals. The controls will be in place with no end date planned. The exception is that the
existing water treatment system is planned to be converted to a passive system by 2015. Groundwater will
continue to be monitored.

Tennessee

24


DOE is committed to maintaining necessary land use controls to ensure that unacceptable exposures to residual
contamination do not occur. A ROD has been signed to implement deed restrictions in the contaminated portion
of Union Valley, where contamination has migrated from the Plant. Specific requirements for groundwater under
the Y-12 Plant will be documented in other ROD(s) and detailed in future land use control implementation
plan(s) to be developed after CERCLA ROD(s) are signed. These controls will be implemented through a permit
program maintained by DOE. Regular monitoring will occur in accordance with agreements reached during
closure. Effectiveness of the remedial actions and long-term stewardship activities will be validated and verified
through the CERCLA five-year review process.

3.3.3

Engineered Units

The engineered units associated with the Upper East Fork Poplar Creek portion are located on Chestnut Ridge.
The largest units are the five landfills (two construction/demolition landfills and three industrial landfills) used
for Y-12 operations. These landfills are not associated with the remediation activities on the Reservation and
will be closed eventually (after 2006) under State solid waste regulations. The landfills occupy approximately
20 hectares (45 acres) of land and have the potential to contain 1,656,000 cubic meters (2, 168,000 cubic yards)
of waste (non-hazardous). Once the landfills are closed, they will be capped in accordance with TDEC solid
waste regulations.
On the same ridge as the landfills are several hazardous waste units, including two quarries (Rogers and Kerr
Hollow), a coal ash pond (known as the Filled Coal Ash Pond), a Gully soil pile, and three capped areas. The
Rogers quarry is approximately four hectares (ten acres) and the Kerr Hollow quarry is one hectare (three acres).
The Rogers quarry contains coal ash, ammunition, and classified material from the Y-12 Plant, which are
covered at the bottom by gravel. The Kerr Hollow quarry contains reactive material and plant debris, some of
which was removed in an early remedial action. The exact volume of residual contamination is unknown in both
quarries. The Filled Coal Ash Pond is four hectares (nine acres) with 188,300 cubic meters (246,300 cubic yards)
of coal ash that was closed in place under a CERCLA ROD. The Gully soil pile of less than 0.4 hectare (one
acre) contains less than 8,000 cubic meters ( 10,000 cubic yards) of plant (mercury) soil with a vegetative cover.
The three capped areas include (1) a two-hectare (four-acre) area, known as the Sediment Disposal Basin, which
contains 8,000 cubic meters (10,000 cubic yards) of soils, sludges, methanol, metals, and other organics; (2) a
two-hectare (six-acre) area, called the Security Pits, with 15,000 cubic meters (20,000 cubic yards) of classified
uranium contaminated material, beryllium, thorium and volatile organic compounds in trenches and auger holes;
and (3) a 0.4-hectare (one-acre) area, called the United Nuclear Corporation Landfill, which contains 31,000
cubic meters (40,000 cubic yards) of uranium contaminated soils and debris. The hazardous waste units are
assumed to be capped in place.

The required long-term stewardship activities will include maintaining caps, monitoring groundwater, and
enforcing institutional controls. Caps are assumed to require periodic replacement and will be maintained in
accordance with closure decisions or appropriate regulations. Specific requirements for the Chestnut Ridge sites
will be documented in a future ROD and detailed in a land use control implementation plan. The land will
remain under DOE ownership and current land use controls will be maintained. The closure plan for the
industrial landfills under state regulations will include long-term stewardship requirements, such as monitoring
and maintenance of the engineered cap for 30 years.

3.3.4

Estimated Long-Term Stewardship Costs for Upper East Fork Poplar Creek Watershed

The Upper East Fork Poplar Creek Watershed is anticipated to require long-term stewardship activities, including
Tennessee

25

National Defense Authot·ization Act (NDAA) Long-Term Stewardship Report

monitoring and maintaining engineered units, monitoring groundwater, and enforcing institutional controls. For
cost estimating purposes, DOE assumes that the engineered caps and the horizontal well will be replaced at 50year intervals. The groundwater monitoring wells will be flushed every ten years and replaced at 50-year
intervals, resulting in a peak in long-term stewardship costs around the year 2050. These controls will be in
place, with no end date planned. The exception is that the existing water treatment system is planned to be
converted to a passive system by 2015, resulting in a cost reduction. Regular monitoring will occur in accordance
with agreements reached in the ROD. Effectiveness of the remedial actions and long-term stewardship activities
will be validated and verified through the CERCLA five-year review process. Monitoring efforts and costs will
decrease over time as a result of stabilizing site conditions. Although costs are only estimated to FY 2070, DOE
anticipates that long-term stewardship activities will be required in perpetuity at most areas.
(watersheds), but rather, by three major areas (Oak Ridge National Laboratory, Y-12 Plant, and East Tennessee
Technology Park). The estimated long-term stewardship costs for the Upper East Fork Poplar Creek Watershed
Portion are based on a percentage of the Y-12 Plant's long-term stewardship costs.
Long-Term Stewardship Costs (Constant Year 2000 Dollars)
F¥2000-FY
2010
$11,005,000

3.4

F¥2011F¥2020

F¥2021F¥2030

F¥2031F¥2040

$9,050,000

$6,235,000

$5,364,000

F¥2041-FY
2050
$14,525,000

F¥2051F¥2060

F¥2061F¥2070

Estimated
Total

$4,099,000

$5,679,000

$55,957,000

East Tennessee Technology Park Watershed Portion

East Tennessee Technology Park (formerly known as
EAST TENNESSEE TECHNOLOGY PARK
the K-25 Site) was built in 1943, during World War II,
WATERSHED PORTION HIGHLIGHTS
as part of the Manhattan Project to supply enriched
Major Long-Term Stewardship Activities -monitoring
uranium for nuclear weapons production. The K-25
building was the first diffusion facility for large-scale
separation of uranium-235. Now, East Tennessee
Estimated Volume of Residual Contaminants- soil
Technology Park is an inactive gaseous diffusion plant.
unknown; groundwater unknown
As a result of past process activities, soil and
groundwater are contaminated.
The soil is
perpetuity
contaminated primarily with radionuclides, and the
groundwater with volatile organic compounds. Solid
2000-2006- $481,000
waste was disposed in burial grounds in several
locations. Contamination moving from the subsurface
to buried storm drains has exited to adjacent surface water bodies. Although the surface water is relatively clean,
as a result of early remediation actions, the sediment and fish in adjacent ponds are contaminated with PCBs,
metals, and radionuclides. The East Tennessee Technology Park facility is identified as a portion because it has
multiple, interrelated contaminated areas with commingled plumes. A single land-use decision (unrestricted
industrial) is anticipated for most of the portion and will necessitate a single set of land use controls.
East Tennessee Technology Park is likely to be divided into two portions for decision making: the area outside
the fence (Zone 1) and the area inside the fence (Zone 2). Surface facilities will be removed, the surface water
and sediment restored to its highest classified use (recreational), and subsurface features decontaminated to limit
the need for institutional controls. All engineered units (i.e., burial grounds) currently containing contamination
will be removed, treated, and disposed at the Environmental Management Waste Facility and offsite. Therefore,
no institutional controls will be needed for facilities, surface water bodies, or engineered units. Consequently,
Tennessee

26


, .................. __ .. _
..

i

·.....

......

_, .. -··

.,.,..·

......-.. J ..
~

.I

_ .. -··-·

.1

/
./

/

EEK

WATERSHED

......··
/

E2222J Groundwater Contamination
~ Soil Contamination

0.5

Miles

East Tennessee Technology Park Watershed
these contaminated media are not addressed in this section.
Currently, DOE is reindustrializing portions of the East Tennessee Technology Park. DOE retains responsibility
for all residual contamination and will complete the remediation of the Plant.

3.4.1

Soil

Approximately 400 hectares (1,000 acres) of potentially contaminated soil are located in the East Tennessee
Technology Park within two zones, either outside or within the current fence (Zone 1 and Zone 2, respectively).
In both zones there are two dominant types of soil contamination. Shallow soil is contaminated by radionuclides
(uranium and small amounts of metals) as a result of surface spills, fallout, and surface runoff. Some areas of
the surface have PCB contamination from electrical switch yards, beryllium contamination around buildings that
used this metal, and chromium contamination around cooling towers. Much of this contamination is below
applicable risk levels, although there are some unacceptable risks to future users of the site. Subsurface soil was
contaminated as a result of subsurface leaks in pipelines and tanks or from burial grounds. This soil tends to be
contaminated with more mobile contaminants, such as volatile organic compounds. The contamination levels
are high in some areas, especially near the historic waste processing areas in Zone 2 (inside the fence) as a result
of waste pipeline leaks. In Zone 1 (outside the fence) operational processes did not transport waste through the
subsurface. In general, Zone 1 soils (outside the fence) are less contaminated than Zone 2 soils (inside the fence).
Tennessee

27

National Defense Authorization Act (NDAA) Long-Term SteHtnlship Repm·t

However, there continue to be uncertainties related to the extent of contamination, especially the depth of soil
contamination. Consequently, the CERCLA decision-making process is in its early stages, and a remedial
decision is not likely until 2004. However, there is a verbal understanding between the Federal Facility
Agreement parties that the top three meters (ten feet) of soil are likely to be remediated to industrial use criteria.
If similar strategies for remediation (excavation of contamination to three meters (ten feet)) are used in both
zones, it is likely that no significant volumes of contaminated soil will remain in Zone 1 (except perhaps under
the K-1070-A burial ground), while significant volumes of contaminated soil (volatile organic compounds) will
remain at depths in Zone 2.

Based on the assumption that contaminated soils in the top three meters (ten feet) will be removed and residual
contamination will remain, below three meters (ten feet) in some locations, long-term stewardship activities such
as institutional controls, will be required. Institutional controls for East Tennessee Technology Park include
subsurface land (below three meters (ten feet)) restrictions, implemented through notices placed on the original
acquisition records for DOE and through a permit program maintained by DOE (excavation permits below three
meters (ten feet)). Specific requirements for East Tennessee Technology Park will be documented in future
RODs, while the details will be developed in future land use control implementation plans. DOE will continue
to ensure that the East Tennessee Technology Park area is not used for residential or agricultural purposes but
rather for industrial use.

3.4.2

Groundwater

Groundwater monitoring at the East Tennessee Technology Park shows contamination in approximately 10
hectares (20 acres) of the site. Leaks of waste transfer pipelines, underground storage tanks, and impoundments
have resulted in the release of radionuclides and volatile organic compounds. Contamination has also moved into
groundwater from disposal practices, especially at the K-1070-A and K-1070-C/D burial grounds. The most
frequently detected contaminants are trichloroethylene (TCE), tetrachloroethylene (PCE), various
dichloroethylene (DCE) isomers, methylene chloride, and chloroform. Contamination in groundwater migrates
though the bedrock and vadose zone. However, there is evidence of natural biodegradation occurring in some
of the plumes at the East Tennessee Technology Park. All plumes are similar in nature and often commingled
underneath the East Tennessee Technology Park. Contamination of groundwater primarily exists under the plant,
but some volatile organic compound contamination from a burial ground has been found outside the fence but
within the DOE property boundary. No known contamination is leaving the site at levels above regulatory limits.
The final groundwater remediation strategy has been deferred from all negotiations. There is significant
disagreement on the strategy, so the Federal Facility Agreement parties have agreed to implement actions to
prevent source contaminant releases and monitor the effects on groundwater before negotiating a final
groundwater strategy. For cost-estimating purposes, the strategy is assumed to be natural attenuation, with no
active restoration. Final groundwater remedial decisions will not be made until after 2006 (assumed to be no
earlier than 2010).

Based on the assumed remedial strategy, DOE will monitor groundwater to assess natural attenuation and to
ensure that groundwater does not migrate offsite nor cause a problem in nearby surface water bodies, including
Mitchell Branch and the K-1007 and K-901-A Ponds. To ensure that unacceptable exposures to residual
contamination do not occur, DOE will maintain land use restrictions. Specific requirements for East Tennessee
Technology Park will be documented in future RODs and will be detailed in future land use control
Tennessee

28


implementation plans. Institutional controls for East Tennessee Technology Park will likely include groundwater
use restrictions (i.e., notices placed on the original acquisition records for DOE and a permit program maintained
by DOE). In addition, the effectiveness of any remedial actions and residual groundwater contamination will
be monitored as frequently as needed to identify changing conditions and will be reported at least every five years
during the five-year review process.

3.4.3

Estimated Long-Term Stewardship Costs for East Tennessee Technology Park Watershed

Long-term stewardship activities that are anticipated for the East Tennessee Technology Park Portion include
monitoring groundwater and enforcing institutional controls. The current costs assume no active groundwater
restoration (only natural attenuation), and there are no appreciable anticipated changes in requirements over time.
Although costs are only estimated to FY 2070, DOE anticipates that long-term stewardship activities will be
required in perpetuity at most areas.
l.on!f·Terin Stewardship Costs (Constant Year 2000 Dollars)
· ..

FY2000·
F¥2010
$5,334,000

3.5

FYZOll~FY

FY202L~

2020

FY2030

F¥2031F¥2040

F¥2041F¥2050

FY2051·
FY2060

P¥2061F¥2070

Estimated
Total

$3,489,000

$3,524,000

$3,317,000

$3,371,000

$3,488,000

$25,898,000

$3,375,000

Melton Valley Watershed Portion

While Oak Ridge National Laboratory's main plant is
located in Bethel Valley, most of its active and inactive
waste management areas are in neighboring Melton
Valley. Contamination in Melton Valley originated
from operations of the Oak Ridge National Laboratory
and other facilities over a 50-year period. Oak Ridge
National Laboratory's historic missions of plutonium
production and chemical separation during World War
II and development of nuclear technology during the
postwar era produced a diverse legacy of waste. In
addition, from 1955 to 1963, Oak Ridge National
Laboratory served as a major disposal site (known as
the Southern Regional Burial Ground) for wastes from
over 50 offsite government-sponsored installations,
research institutions, and other isotope users. Transport
from waste disposal areas to surface water via
subsurface flow paths (e.g., leachate migration) is the
predominant contaminant migration pathway. The
contaminated areas in Melton Valley may be grouped
for descriptive purposes as follows:
•
•
•
•
•

MELTON VALLEY WATERSHED PORTION
HIGHLIGHTS
Major Long-Term Stewardship Activities - maintaining

engineered barriers; monitoring groundwater;
enforcing institutional controls
*Estimated Volume of Residual Contaminants- soil
groundwater unknown; surface water/ sediment
engineered units 2,627,000 cubic meters (3,815,000
cubic yards); facilities 1,500 cubic meters (2,000 cubic
yards)
perpetuity
2000-2006- $1,124,000

inactive waste disposal sites containing buried radiological and chemical wastes;
inactive liquid waste seepage pits and trenches;
several inactive wastewater impoundments;
abandoned underground liquid waste transfer pipelines and associated historic leak and spill sites;
secondary contamination of soil adjacent to contaminant sources;
contaminated floodplain soil and sediment;

Tennessee

29


•

various inactive facilities and structures with no designated future use (excess); and
deep-injected radiological waste and grout mixtures associated with four formerly used hydrofracture
test/waste disposal facilities.

In general, the major problems in the watershed include (1) continuing contaminant releases (e.g., strontium-90,
tritium, cesium-137) from sources to groundwater and surface water; (2) the presence of high inventories of short
half-life radiological waste and lesser quantities oflong half-life material, particularly within the burial grounds;
and (3) widespread distribution of radiological contaminants in soil and groundwater. Contamination is present
in soil, groundwater, surface water/sediments, engineered units, and facilities. Approval of a ROD for the Melton
Valley watershed should occur in FY 2000. However, the ROD will not address two inactive reactors
(Homogeneous Reactor Experiment and Molten Salt Reactor Experiment), active units, and contaminated units
that are within Melton Valley but outside the Melton Valley watershed ROD area. The selected remedy will
isolate, treat, or remove most of the known sources of contamination in the watershed and significantly reduce
the release of contaminants from source areas into streams that carry contamination offsite. The eastern portion
of Melton Valley, which contains the reactor sites, will be remediated to a condition that allows industrial use
with limited restrictions. Much of the central and western portion of Melton Valley, occupied by the waste
disposal sites, will continue to be a waste management area with wastes contained in place and access restricted.
The Melton Valley Watershed ROD establishes two different remediation areas related to reasonably anticipated
future land uses. However, the land use control objectives for the areas are similar. Acceptable uses of the
remediation areas within the Melton Valley watershed include: industrial activities associated with ongoing Oak
Ridge National Laboratory operations; remediation activities, including environmental monitoring of ground and
surface water; surveillance and maintenance activities, including inspections or walkdowns of waste management
areas; and routine security patrols. The land use controls are implemented through the permit program and
through engineered controls, such as DOE excavation fences/gates, signs, and caps.

3.5.1

Soil

Soil in Melton Valley is treated as a single medium because the contaminants, causes of contamination, and
remedial action objectives (e.g., mitigate further impact to groundwater, protect surface water, and protect postremediation workers) are similar throughout the valley. (Note: Soil in this context does not include floodplain
soil, which is combined with the surface water/sediment discussion.) Two hundred and twenty-five hectares (555
acres) of soil in Melton Valley are contaminated primarily with radionuclides, such as cesium-137 and cobalt-60.
Causes of soil contamination include:
material spills on the surface;

•

contaminated biological material, including leaves and animal droppings;
pipeline leaks;

•

contaminated seepage during operation of the Seepage Pits and Trenches; and
migration of contaminated seepage and groundwater originating as leachate in primary source areas, such
as waste burial trenches.

Surface-contaminated areas range in size from small hot spots for material spills to areas less than 0.4 hectare
(one acre) for most pipeline leaks. The primary subsurface contamination will be along contaminant migration
pathways between sources and surface water. The many contaminated soil areas within the watershed release
Tennessee

30

Tennessee

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