EPA/ROD/R04-96/260
1996
EPA Superfund
Record of Decision:
OAK RIDGE RESERVATION (USDOE)
EPA ID: TN1890090003
OU26
OAK RIDGE, TN
02/21/1996
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DOE/OR02-1410&D3
Record of Decision
for
Chestnut Ridge Operable Unit 2
(Filled Coal Ash Pond and Vicinity)
Oak Ridge, Tennessee
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DOE/OR/02-1410&D3
Record of Decision
for
Chestnut Ridge Operable Unit 2
(Filled Coal Ash Pond and Vicinity)
Oak Ridge, Tennessee
Date Issued-January 1996
Prepared by
Jacobs ER Team
125 Broadway Avenue
Oak Ridge, Tennessee
under contract DE-AC05-930R22028
Prepared for
U.S. Department of Energy
Office of Environmental Restoration and Waste Management
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PREFACE
This Record of Decision for Chestnut Ridge Operable Unit 2 (Filled Coal Ash Pond and Vicinity),
Oak Ridge, Tennessee (DOE/OR/02-1410&D3) was prepared in accordance with reguirements under the
Comprehensive Environmental Response, Compensation, and Liability Act to present the selected
remedy to the public. This work was performed under Work Breakdown Structure 1.4.12.3.1.01
(Activity Data Sheet 2301, "Filled Coal Ash Pond"). This document provides the Environmental
Restoration Program with information about the selected remedy for Chestnut Ridge Operable Unit
2, which involves improving and stabilizing the 62-ft dam that retains the coal ash, performing
limited environmental enhancements, and implementing institutional controls to limit access to
the site. Information in this document summarizes information from the remedial investigation
(DOE/OR/01-1268/V1&V2-D2), the feasibility study (DOE/OR/02-1259&D2), and the proposed
plan(DOE/OR/02-1329&D2).
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ACRONYMS AND ABBREVIATIONS
Al
ARAR
As
Ba
Be
Cd
CERCLA
CFR
COG
COPC
Cr
Cs
Cu
DOE
EPA
FCAP
Fe
FFA
FR
FS
ft
ha
Hg
K
km
L
m
MCL
Mn
MSDS
Na
NCP
NPL
O&M
ORR
OU
Pb
pCi
PMP
Ra
RCRA
RI
ROD
aluminum
applicable or relevant and appropriate requirement
arsenic
barium
beryllium
cadmium
Comprehensive Environmental Response, Compensation, and Liability Act of 1980
Code of Federal Regulations
contaminant of concern
contaminant of potential concern
chromium
cesium
copper
U.S. Department of Energy
U.S. Environmental Protection Agency
Filled Coal Ash Pond
iron
Federal Facility Agreement
Federal Register
feasibility study
foot
hectare
mercury
potassium
kilometer
liter
meter
maximum contaminant level
manganese
Material Safety Data Sheet
sodium
National Contingency Plan
National Priorities List
operation and maintenance
Oak Ridge Reservation
operable unit
lead
picocurie
probable maximum precipitation
radium
Resource Conservation and Recovery Act
remedial investigation
record of decision
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ACRONYMS AND ABBREVIATIONS (continued)
SARA Superfund Amendments and Reauthorization Act of 1986
Se selenium
SHPO state historic preservation officer
SWMU solid waste management unit
TDEC Tennessee Department of Environment and Conservation
Th thorium
Tl thallium
U uranium
USC United States Code
V vanadium
Zn zinc
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PART 1. DECLARATION
SITE NAME AND LOCATION
U.S. Department of Energy
Oak Ridge Y-12 Plant Chestnut Ridge Operable Unit 2
Oak Ridge Reservation
Oak Ridge, Tennessee
STATEMENT OF BASIS AND PURPOSE
This record of decision (ROD) presents the selected remedial action for the Oak Ridge Y-12 Plant
Chestnut Ridge Operable Unit (OU) 2, also known as the Filled Coal Ash Pond (FCAP). FCAP is on
the U.S. Department of Energy (DOE) Oak Ridge Reservation (ORR) in Oak Ridge, Tennessee. The
action was chosen in accordance with the Comprehensive Environmental Response, Compensation, and
Liability Act of 1980 (CERCLA) , as amended by the Superfund Amendments and Reauthorization Act
of 1986 (SARA), 42 United States Code (USC) Section 9601 et seg., and to the extent practicable,
the National Oil and Hazardous Substance Contingency Plan.
This decision is based on the administrative record for the Y-12 Plant Chestnut Ridge OU 2,
including the remedial investigation (RI) report (COM 1995), the feasibility study (FS) report
(Jacobs ER Team 1995a), the proposed plan (Jacobs ER Team 1995b), and other documents contained
in the administrative record file for this site.
This document is issued by DOE as the lead agency. The U.S. Environmental Protection Agency
(EPA) and Tennessee Department of Environment and Conservation (TDEC) are supportive agencies as
parties of the Federal Facility Agreement (FFA) for this remedial action, and they concur with
the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this site may present an unacceptable
risk to public health, welfare, or the environment if not addressed by implementing the response
action selected in this ROD.
DESCRIPTION OF THE SELECTED REMEDY
This response action fits into the overall ORR cleanup strategy by addressing surface water and
soil contaminated by coal ash and its leachate originating from the FCAP on Chestnut Ridge,
south of the Y-12 Plant.
The selected remedy addresses the principal threats from the site to plants, animals, and
humans by (1) upgrading containment of the coal ash with dam improvements and stabilization, (2)
reducing contaminant migration into Upper McCoy Branch with a passive treatment system, and (3)
restricting human access to the contamination by implementing institutional controls. Major
components of the selected remedy are designed to:
• minimize the migration of contaminants into surface water,
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minimize direct contact of humans and animals with the ash,
reduce the potential for future failure of the dam, and
preserve the local habitat in the long term.
STATUTORY DETERMINATIONS
The selected remedy protects human health and the environment, complies with federal and state
requirements that are legally applicable or relevant and appropriate, and is cost-effective.
The selected remedy uses permanent solutions and alternative treatment technologies to the
maximum extent practicable for this site. The selected remedy does not satisfy the statutory
preference for treatment, which results in permanent and significant reduction of toxicity,
mobility, or volume of the contamination, because treatment of the large volume of coal ash at
this site is not practicable. The ash will remain in place at the site, and surface water will
receive limited treatment. Institutional controls will restrict access to the contamination and
reduce risk to human health. Actions taken to isolate the ash, restrict animal access, and
reduce contaminant migration to surface water will reduce risk to ecological receptors. As
required for remedies in which waste is left in place, a 5-year review will be conducted to
verify that the remedy continues to protect human health and the environment.
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APPROVALS
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James Hall, Manager Date
U.S. Department of Energy
Oak Ridge Operations
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Earl C. Leming, Director Date
U.S. Department of Energy Oversight Division
Tennessee Department of Environment and Conservation
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PART 2. DECISION SUMMARY
SITE NAME, LOCATION, AND DESCRIPTION
ORR is a 14,000-ha (35,000-acre) DOE facility in Anderson and Roane Counties, about 38 km (24
miles) northwest of Knoxville, Tennessee. The Y-12 Plant is on 324 ha (800 acres) in Bear Creek
Valley, 3.2 km (2 miles) south of downtown Oak Ridge (Fig. 2.1).
FCAP is on Chestnut Ridge, approximately 0.8 km (0.5 miles) south of the Y-12 Plant (Fig. 2.2).
The pond was constructed by building a southwest-facing earthen dam across Upper McCoy Branch
(Fig. 2.3). The pond was used as a settling basin for coal ash slurry from the Y-12 Steam Plant
from 1955 to 1967, when the pond was filled. From 1967 to 1989, the slurry continued to be
discharged to the pond and then flowed across the dam down the Upper McCoy Branch and into
Rogers Quarry.
Upper McCoy Branch has its headwaters along two tributaries near the crest of Chestnut Ridge.
The tributaries join at the ash pond. Water flows over and through the ash in the pond.
Surface water flows down the existing eroded spillway on the eastern end of the earthen dam.
Subsurface flow exits in seeps and springs below the dam. Although minimal erosion appears to
be occurring on the downstream dam face that is covered with grass and ground vegetation, the
spillway channel for the darn has eroded approximately 4.6m (15 ft) deep.
At the base of the dam is a spring that is a discharge point for groundwater. Water from this
spring has cut a channel approximately 0.9 m (3 ft) deep into the valley. At times of heavy
rainfall the stream sometimes overflows its banks. Since 1967, when the stream was diverted
from flowing into Melton Hill Reservoir, Upper McCoy Branch has flowed approximately 0.8 km (0.5
miles) from the dam to Rogers Quarry, a 4-ha (10-acre) guarry that was used as a source of stone
in the 1940s.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
The 19-m (62-ft)-high earthen dam across Upper McCoy Branch was constructed in 1955 to create a
pond to serve as a settling basin for fly and bottom ashes generated by burning coal at the Y-12
Steam Plant. Ash from the steam plant was mixed with water to form a slurry and then pumped to
the crest of Chestnut Ridge and released through a large pipe to flow across the Sluice Channel
area and into the pond. The ash slurry eventually overtopped the dam and flowed along Upper
McCoy Branch to Rogers Quarry. In 1989, a bypass pipe was constructed to carry the slurry
directly to the guarry from the steam plant. All discharges from the steam plant to the ash
pond stopped in 1989. Since then ash deposits in the ash pond, Upper McCoy floodplain, and the
Sluice Channel Area have been left in place. The site is now well vegetated.
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FCAP was originally listed as a Resource Conservation and Recovery Act (RCRA) Section 3004(u)
solid waste management unit (SWMU) under the 1984 Hazardous and Solid Waste Amendments general
permit for ORR (Welch 1989). At that time, coal ash was subject to regulation as a hazardous
waste under RCRA Subtitle C. ORR was subseguently listed on the National Priorities List (NPL),
making FCAP subject to CERCLA regulations. In 1992, as a result of the FFA, CERCLA reguirements
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were invoked for the preparation of the planning and decision documents for the FCAP area, as
well as the actual remediation. Fly and bottom ashes were later exempted from hazardous waste
regulation under Subtitle C [58 Federal Register (FR) 42466, August 9, 1993], although the ash
is still regulated as solid waste under Subtitle D. The site remains a CERCLA OU.
Site investigations under RCRA and CERCLA began in 1990 in which surface water, soils, ash, and
groundwater were sampled. An RI report, an FS report, and a proposed plan were completed in
accordance with CERCLA and the FFA (1992). This ROD presents the decision for Chestnut Ridge OU
2 and is based on information contained in the administrative record.
HIGHLIGHTS OF COMMUNITY PARTICIPATION
The proposed plan for Chestnut Ridge OU 2 was issued in June 1995. DOE published a public
notice regarding the project in The Knoxville News-Sentinel July 5, 1995, and set a public
comment period from July 5, 1995, to August 5, 1995. The proposed plan was one of the topics
discussed at the guarterly July 18, 1995, stakeholders meeting. No formal public meeting was
reguested. Few comments were received and few issues were raised by the public. Part 3 of this
document, "Responsiveness Summary," addresses the informal comments made by the public during
the July 18, 1995, stakeholders meeting, telephoned comments, and written comments received
during the public comment period. Subseguent to comments and guestions submitted during the
period of community participation, DOE, in concurrence with the other FFA parties, determined
that the actions suggested in the proposed plan, with some modifications, are justified. These
modifications to the selected remedy are described in the "Documentation of Significant Changes"
section.
SCOPE AND ROLE OF RESPONSE ACTION
The response action for FCAP will address contaminant abatement for surface waters, sediments,
and soils of Upper McCoy Branch and will upgrade the dam to reduce risk of an uncontrolled
release of the ash into the Upper McCoy Branch watershed. The principal threat to human health
is limited risks from exposure to the radionuclide 228Th and its daughters through direct
exposure to the ash under hypothetical trespasser and residential scenarios. Current risks to
the environment are primarily to terrestrial biota through exposure and potential accumulation
of selenium and arsenic from uptake or ingestion of the ash, its leachate, or organisms affected
by it. The purposes and components of this response action are to (1) reduce or eliminate the
risk of an uncontrolled release by strengthening the dam and spillway, (2) restrict human access
to the site to control the potential for direct exposure, and (3) reduce or eliminate
contaminant entry into the Upper McCoy Branch surface waters through enhancement of an existing
wetland which currently acts as a natural passive treatment system. Implementation of these
measures will constitute the final response action for this OU.
SUMMARY OF SITE CHARACTERISTICS
The nature and extent of contamination at the ash pond and vicinity were investigated by
sampling and analyzing the ash, surface water, sediments, soil, and groundwater. Analysis of
the ash for metals and radioactive substances indicates the ash is typical of coal ash from the
combustion of eastern United States coals. Radioactivity in the coal ash is above background
levels in soil (Energy Systems 1993); however, this is common to coal ash residues and not a
result of plant processes associated with the Y-12 Plant. Contaminants leaching from the ash
into underlying soil or surface water are primarily metals. Reference samples were collected as
part of the RI for surface water, sediments, and groundwater to provide indicators of nearby
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site conditions (CDM 1995). Soil data were compared to published background levels of soils at
ORR (Energy Systems 1993). Ash data were also compared to published data for coal ash
constituents (CDM 1995).
Surface water characterization during the RI indicated that the primary contaminants in surface
water exceeding levels of nearby sampled reference points are metals, including Al, As, Fe, Mn,
and Zn. Levels of Cu, Pb, Hg, Th isotopes, and 238U were also elevated in comparison to
reference sample levels in the surface water, but to a lesser extent. Contaminant
concentrations are consistently lower in the downstream water of Upper McCoy Branch, indicating
that ash deposits in the floodplain and creek are not a primary source of surface water
contaminants (CDM 1995).
Background concentrations of soil constituents were obtained from the Background Soil
Characterization Project for the Oak Ridge Reservation (Energy Systems 1993). Soil samples were
collected from beneath the ash at five locations along Upper McCoy Branch, beneath the ash at
FCAP, and in the Sluice Channel. All the metals, except mercury and uranium, exceeded the
background soil means in one or more samples. Arsenic and iron were the most elevated metals
when compared to the background levels for local soils. Leachate from ash was detected in the
underlying soil at the sampling locations.
Surface ash samples were collected from FCAP. The maximum metal concentration in ash exceeded
the maximum background level for local soil in all eases except manganese, which is naturally
high in local soils. Arsenic and iron concentrations were an order of magnitude greater than
the background samples; however, these contaminants are commonly found in coal ash at the
detected levels (CDM 1995).
Sediment samples were collected from nearby reference locations to determine reference levels
and at 12 potentially affected locations adjacent to springs or seeps. Aluminum, Ba, Fe, Mn, K,
and Na in the sediment are well above reference sediment levels. Uranium-238 and 232Th are also
elevated. The elevated levels of these metals and all radionuclides are typically associated
with coal and coal ash.
Groundwater quality for eight monitoring wells within Chestnut Ridge OU 2 was monitored during
RI characterization of FCAP. Four of the eight wells are screened in the overburden and the
other four are screened within the bedrock. Six piezometers were installed to evaluate flow
directions. Certain samples were analyzed for total and dissolved metals, radiological
parameters, common ions, various physical properties, volatile organic compounds, and
semivolatile organic compounds.
Groundwater data from Chestnut Ridge OU 2 suggest that former activities at the site have had
some impact on the groundwater, but the impact is limited. Data from both phases include four
maximum contaminant level (MCL) exceedences for one analyte; initial samples from a duplicate
sample at GW-676 exceeded the gross alpha MCL of 15 pCi/L. Interpretation of the groundwater
data was problematic because a karst geologic system has developed on Chestnut Ridge. Initial
attempts to compare topographically upgradient groundwater data to topographically downgradient
well data were unsuccessful. The presence and extent of organics, metals, and radionuclides in
groundwater at OU 2 is limited (CDM 1995).
SUMMARY OF SITE RISKS
HUMAN HEALTH RISKS
Human health risks were evaluated for current and future baseline conditions and were presented
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in the RI report (CDM 1995) . All scenarios were evaluated in the risk assessment using the
upper 95 percent confidence limit of the mean concentrations. Current risks were evaluated for
industrial workers given existing institutional controls and were found to be acceptable.
Future risks were estimated for trespasser and on-site resident scenarios. The most likely
future exposure scenario was a trespasser scenario. Under this scenario, a hunter was
hypothesized to spend 2 weeks each year on the site for 30 years. The actual site-specific
allowable hunting days are currently fewer than the assumed 2 weeks. For this scenario, the
excess cancer risk from external gamma exposures from the naturally occurring radionuclides in
the coal ash was assessed. The risk was 6 x 10-5, which is within the EPA target risk range of
1 x 10-6 to 1 x 10-4 (EPA 1990). None of the contaminants of potential concern (COPCs) for
groundwater exceeded acceptable risk levels using the trespasser scenario. This was the land
use scenario used for selection of the remedy.
The second exposure scenario assumes that a future on-site resident is exposed to contaminants
for 350 days each year for 30 years, as a child during the first 6 years and as an adult during
the next 24 years. This scenario considered dermal contact with soil/ash, incidental ingestion
of soil/ash, inhalation of these contaminated media, and direct gamma exposures; ingestion of
homegrown vegetables and fruit; ingestion of contaminated surface and groundwater; and dermal
contact with surface and groundwater and inhalation of volatile organic compounds. By using the
upper 95 percent confidence limit of the mean values in conjunction with this residential
exposure scenario, it is unlikely that actual risks at the site have been underestimated. The
total excess cancer risk was calculated to be 1 x 10-3, of which 92 percent was attributable to
external gamma exposures to 228Th and its daughters, most notably 208T1. This is unacceptable
because the cancer risk is greater than EPA's target range for acceptable risk. For
noncarcinogenic risks for the on-site resident, hazard indices greater than 1 (unacceptable by
EPA guidance) were determined for arsenic and manganese from ingestion of surface water and
homegrown produce. Ingestion of home garden produce also had hazard indices greater than 1 for
mercury and cadmium.
ECOLOGICAL RISKS
Although toxicity tests indicate that the surface water stream (Upper McCoy Branch) is
recovering from the detrimental effects of the coal ash, the coal ash itself is toxic to soil
invertebrates. Metal concentrations in sediments and surface water of Upper McCoy Branch
exceeded ecological risk benchmarks and were sufficient to reduce survival or reproduction of
benthic macroinvertebrates. Successful growth and reproduction of plants has been observed at
the FCAP, Sluice Channel Area, and Upper McCoy Branch sites. However, evidence of contaminant
accumulation in plants was observed on FCAP when tissue analyses were performed. Aluminum, As,
Se, and V represented the highest risks to plants. Additionally, selenium and arsenic is taken
up by some plants on the site, which poses potential risks to vegetation and animals in the food
chain. The surface water, which serves as a drinking water source for area wildlife, and coal
ash, which is ingested by the deer as a mineral supplement, could also have a detrimental effect
on these animals. Furthermore, Al, Cd, Cr, Cu, Fe, Mn, Hg, V, and Zn concentrations in the ash
could cause reduced microbial growth and reduction in the activities of enzymes involved in
organic matter breakdown and nutrient cycling.
Future site risks are expected to be similar to or less than the current risks, except in a
catastrophic dam failure. Such a failure is possible in the long term because of dam erosion
caused by high intensity storms. Dam failure and the subseguent release of ash would create
significantly higher risks to human health and the environment because ash exposures would be
dramatically increased.
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DESCRIPTION OF ALTERNATIVES
Nine remedial alternatives spanning a wide range of cleanup options for Chestnut Ridge OU 2 were
developed in the FS (Jacobs ER Team 1995a). The alternatives developed ranged from no action to
complete removal and off-site disposal of the ash. The nine alternatives were screened in the
FS based on effectiveness, implementability, and cost to develop a shorter list of alternatives
for detailed analysis. In the application of all action alternatives, best management practices
would be followed to control fugitive dust, erosion, runoff, and to minimize the area disturbed.
Descriptions of the alternatives and results of the screening process are provided in the
following paragraphs.
ALTERNATIVE 1: NO ACTION
The no action alternative provides a comparative baseline against which other alternatives can
be evaluated. It was retained for detailed analysis in the FS, as reguired by the National
Contingency Plan (NCP). Under this alternative, no action would be implemented and the material
in the coal ash waste areas (i.e., the Sluice Channel Area, FCAP, and Upper McCoy Branch) would
be left "as is," without implementing any containment, removal, treatment, or other mitigating
actions. This alternative does not provide for soil, surface water, or groundwater monitoring,
and it does not use institutional controls to reduce the potential for exposure (e.g., physical
barriers, deed restrictions).
ALTERNATIVE 2: INSTITUTIONAL CONTROLS AND ENVIRONMENTAL ENHANCEMENT
Alternative 2 is intended to enhance the ongoing recovery of site vegetation and habitats, while
providing controls to limit the access and use of the site to reduce human and ecological
exposures by direct or indirect contact. This alternative includes access and use controls,
monitoring, and environmental enhancements (placing salt licks on site, adding nutrients and
organic material to the ash, planting preferred species, and installing a passive treatment
system at the toe of the FCAP dam). This alternative was screened out from detailed
analysis in the FS because it does not protect against dam failure.
ALTERNATIVE 3: INSTITUTIONAL CONTROLS AND DAM IMPROVEMENTS
Alternative 3 includes institutional controls, monitoring, environmental enhancements described
in Alternative 2, and adds dam improvements. The dam improvements are intended to repair
existing erosion damage to the emergency spillway on the eastern end of the dam. This
alternative was also screened out because it does not provide enough stormwater retention
capacity to prevent overtopping and erosion of the dam.
ALTERNATIVE 4: SURFACE WATER CONTROLS AND DAM IMPROVEMENTS
Alternative 4 includes institutional controls, environmental enhancements, dam improvements,
surface controls, and monitoring. Alternative 4 was retained for detailed analysis in the FS.
The following describes the primary components of this alternative.
Institutional Controls. Deed restrictions, fencing, and signs would be used to limit access to
the site.
Environmental Enhancements. Environmental enhancements include establishing salt licks, adding
nutrients and organic material to the ash, and planting or seeding of preferred species.
• On-Site Salt Licks-Salt licks would be established on or immediately adjacent to the
site at strategic locations as a replacement source of mineral intake for deer that
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now use FCAP as a "natural" salt lick. Salt licks would reduce deer exposure to ash
and contaminated soil through ingestion. Existing patches of exposed ash sculled by
deer would be covered with topsoil.
• Nutrient Addition-Nutrients, in the form of granular or dissolved fertilizer, would
be added to the ash to accelerate the accumulation of plant biomass in order to
dilute the accumulated contaminants and reduce further contaminant uptake. For
example, selenium uptake would be reduced by adding sulphur, and arsenic by adding
phosphorus. Over time, this would dilute selenium and arsenic concentrations in
plant tissues and also reduce animal exposure to these contaminants. The addition
of other nutrients, such as nitrogen and potassium, would promote overall vegetative
growth and further dilute contaminant concentrations in plant and animal tissue.
Fertilization of already vegetated areas typically results in a "jump-start" to the
plant growth already present. Thereafter, the process accelerates on its own. Risk
levels will also decrease on an ongoing basis.
• Organic Material Addition-Weathered organic material, such as manure or compost,
would be added to the ash to enhance soil microbial populations and soil texture and
expedite the natural recovery process. This would be done once.
• Planting/Seeding of Preferred Species-The perimeter of FCAP and areas below the dam
where wetlands are present would be seeded or planted with facultative,
nitrogen-fixing, wetland species with high habitat values and local hardiness. This
would expedite the natural recovery process and maintain wetland habitats. This
would be done once, monitored for success, and repeated if weather conditions
interfere with plant establishment.
• Passive Treatment System-A passive water treatment system would be constructed near
the toe of the dam, upstream of the spillway outfall after dam and spillway
improvements are complete. Water seepage and runoff from the vicinity of the dam
toe would be directed into a riprap area for oxygenation and a small sedimentation
basin. Flow from this basin would then enter the wetland [approximately 0.2 ha (0.5
acre)], which would be relocated from the toe of the dam to just below the basin.
The passive treatment system is intended to treat only the seepage water described
above. Any additional site runoff and/or storm flow would exceed the capacity of
the system and the space at the toe. Appropriate mitigation, according to best
management practices, would be followed throughout construction.
Dam Improvements. Dam improvements would consist of the following elements:
• Spillway Repair-Erosion damage in the spillway would be repaired by filling and
compacting the spillway area on the eastern end of the dam with suitable material.
The adjacent slope would be backfilled and regraded.
Surface Water Controls. Surface controls include the following:
• Surface Water Diversions-Aboveground pipes and other methods would be used to
collect surface water and divert it around FCAP to reduce water flow through the
ash. Water would be released below the dam.
• Raising the Crest of the Dam-The crest of the FCAP dam would be raised by placing
compacted fill at the top of the dam. The existing crest is almost level with the
top of the impounded ash; thus, there is no capacity for impoundment of stormwater
behind the dam. Greater storage capacity is reguired to properly control the
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discharge of water through the spillway. Raising the crest would also prevent
uncontrolled surface flow from overtopping the dam and the resulting erosion damage.
• Revegetation-Sediment runoff due to erosion would be minimized by establishing a
vegetative cover (e.g., by seeding with native grasses) on areas where excavation or
other disturbance of natural vegetation may have occurred.
Monitoring. This component is intended to ensure that the engineered features of the remedial
actions continue to perform as expected and meet regulatory reporting reguirements. Long-term
physical surveillance of the darn will be conducted to determine future maintenance needs and
prevent failure. Surface water and groundwater would be monitored to evaluate effectiveness and
determine if existing and future receptors are threatened.
ALTERNATIVE 5: SURFACE WATER CONTROLS AND DAM STABILIZATION
Alternative 5 adds dam stabilization and includes institutional controls, environmental
enhancements, dam improvements, surface water controls, and monitoring described in Alternative
4. Alternative 5 was retained for detailed analysis.
Dam Stabilization. Dam stabilization would provide all additional modifications necessary to
satisfy reguirements in the Tennessee Safe Dam Act of 1973, as amended May 1991. Following are
some components that may be included in dam stabilization if deemed necessary in the detailed
design phase.
• Rock Buttress-The entire outslope of the dam would be stabilized with a rock
buttress to provide enhanced structural stability.
• Riprap-Rock riprap or gabions (rock-filled baskets) would be installed, as reguired,
for slope protection due to high velocity flow under design conditions.
• Subsurface Drains-A subsurface drain would be installed at the toe of the dam, near
the abandoned principal spillway outlet, to control seepage from and around the
outlet pipe. The pipe (to be grouted) is blocked because the entire standpipe on
the upstream side of the dam is filled with ash and buried below the FCAP surface.
ALTERNATIVE 6: CAP
Alternative 6 is a containment alternative intended to isolate the coal ash at FCAP, the Sluice
Channel area, and Upper McCoy Branch from the environment and to reduce the generation and
release of contaminated leachate to surface water. This alternative includes bulk liguid
removal, wastewater discharge, surface flow controls, access and use controls, monitoring, dam
improvements and stabilization, dust suppression, and capping. This alternative also would
include construction of a clay cap over all coal ash and permanent diversion of surface water
flow. This alternative was screened out because it is much more costly than retained
alternatives, yet does not improve long-term reliability or effectiveness in protecting human
health and the environment.
ALTERNATIVE 7: WASTE CONSOLIDATION AND CAPPING
Alternative 7 is identical to Alternative 6, except that waste would be excavated from the
Sluice Channel Area and Upper McCoy Branch and consolidated into FCAP before capping. This
additional measure would reduce the areal extent of the waste to be capped. The reduction in
cap surface area would reduce material and labor costs in building the cap. This alternative
was screened out because of little improvement in effectiveness at a much greater cost and
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negative short-term effects to the environment.
ALTERNATIVE 8: WASTE CONSOLIDATION AND STABILIZATION AND CAPPING
Alternative 8 is identical to Alternative 7, except that in situ waste stabilization is added.
Waste stabilization would minimize the potential for long-term waste settlement and the release
of contaminants to the surface water and groundwater. Shallow soil mixing and the addition of
stabilizing reagents is the specific stabilization method that would be implemented under this
alternative. This alternative was screened out because of its limited additional effectiveness
versus cost and negative short-term effects to the environment.
ALTERNATIVE 9: EXCAVATION AND OFF-SITE DISPOSAL
Alternative 9 includes excavation of solids and sediments and lowering of moisture content by
use of a thickening agent, bulk liguid removal and wastewater discharge, sediment control
barriers during excavation, grading and revegetation; solids disposal at an off-site solid waste
disposal facility, and site restoration. Waste would be treated to the extent necessary to meet
the transportation reguirements and waste acceptance criteria of the off-site disposal facility.
Alternative 9 was retained for detailed analysis to address the regulatory preference for
removal and treatment.
All coal ash and underlying contaminated soils in the Sluice Channel Area, FCAP, and Upper McCoy
Branch would be excavated by dredging and dry mechanical excavation methods, as reguired.
Incidental and standing water, construction stormwater, and decontamination water would be
pumped into tank trucks and transported to the Y-12 West End Treatment Facility. The waste
would be excavated and blended with a thickening agent to lower the overall moisture content.
The waste would be placed in trucks, sealed with liners, and transported to the disposal
facility. The dam would be excavated and removed and, after sampling and analysis, soil with
contaminant concentrations below action levels would be used to backfill and regrade the site.
When excavation is complete, the site would be restored by grading to original (predam
construction), natural contours, establishing native plant species, and allowing natural
vegetative succession. Maintenance and postremedial action monitoring would not be reguired
under this alternative.
Chestnut Ridge Landfill is the designated off-site solid waste disposal facility, owned and
operated by Waste Management of North America. The landfill is approximately 16 km (10 miles)
west of the OU 2 site in Heiskell, Tennessee. This landfill formerly accepted coal ash produced
by the ORR K-25 Site and currently accepts ash from the Y-12 Steam Plant. The moisture content
of the waste would be lowered to meet waste acceptance criteria, and documentation would be
provided showing that the waste passes toxicity characteristic leaching procedure metals testing
and the paint filter test for release of free liguids. All necessary approvals and
certifications would be provided before shipment.
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
DOE, TDEC, and EPA screened the nine alternatives in the FS. After consideration, four
alternatives (Alternatives 1, 4, 5, and 9) were retained for detailed analysis and evaluation
against the nine criteria provided by CERCLA for final remedial actions.
OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
This criterion addresses an alternative's ability to provide adeguate long- and short-term
protection of human health and the environment. All of the alternatives except the no action
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alternative adequately protect human health and the environment by eliminating, reducing, or
controlling risk through treatment, engineering controls, or institutional actions.
The overall protectiveness of the three action alternatives is approximately the same.
Alternative 9 is slightly more reliable because off-site disposal removes the source of
contamination from the site. Alternatives 4 and 5 would achieve protection by repairing the dam
spillway, raising the crest of the dam, diverting uncontaminated runoff around FCAP, providing
environmental enhancements, and implementing institutional controls.
The no action alternative is not considered further in this comparative analysis of alternatives
because it does not provide the most basic requirement of protecting human health and the
environment.
COMPLIANCE WITH APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
This criterion addresses an alternative's ability to meet applicable or relevant and appropriate
requirements (ARARs) of all federal and state environmental statutes.
Alternatives 4, 5, and 9 comply with identified federal and state ARARs. The "Statutory
Determinations" section summarizes the ARARs for the selected remedy.
LONG-TERM EFFECTIVENESS AND PERMANENCE
Long-term effectiveness and permanence refers to the magnitude of expected residual risk and the
ability of a remedy to maintain reliable protection of human health and the environment over
time, once cleanup goals have been met.
Alternatives 4, 5, and 9 would be effective in the long term and provide permanent solutions.
Alternatives 4 and 5 provide institutional controls, surface water controls, and dam
improvements while leaving the ash in place and enhancing the rate of natural recovery in the
area. These alternatives would be equally effective in reducing the residual risks to potential
receptors, with the exception that Alternative 5 would have slightly greater long-term
reliability because of the additional structural stabilization of the dam. Alternative 9
would be slightly more reliable in reducing residual risks to potential receptors at the site
because all ash and contaminated soil would be removed, and there would be no on-site dependence
on the reliability of institutional controls.
Long-term environmental impacts are dramatically different between the on-site and off- site
disposal alternatives. Minimal impacts would occur under Alternatives 4 and 5, and no critical
habitats of threatened or endangered species would be directly affected. Construction of the
dam modifications for Alternative 5 would affect a portion of the small wetland [less than 0.2
ha (0.5 acre)] below the dam. This would be mitigated by relocating the wetland slightly
downstream as part of the passive treatment system. Because of the extensive excavation and
removal of all ash and contaminated soil to health-based levels, Alternative 9 would destroy
existing site habitats, including several acres of wetlands. The affected habitats would
eventually recover, but it would take 30-50 years for the area to reach successional stages
equivalent to those currently present.
REDUCTION OF TOXICITY, MOBILITY, OR VOLUME THROUGH TREATMENT
Reduction of toxicity, mobility, or volume through treatment addresses the anticipated
performance of treatment that permanently and significantly reduces toxicity, mobility, or
volume of waste.
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Alternatives 4 and 5 would not reduce toxicity or mobility of the ash in FCAP through treatment.
The passive treatment system would remove and concentrate contamination from surface water;
however, this would result in only a slight reduction of contaminant volume. Alternative 9
increases the volume and decreases the mobility of contaminants due to the addition of lime to
meet the waste acceptance criteria of the off-site disposal facility.
SHORT-TERM EFFECTIVENESS AND ENVIRONMENTAL IMPACTS
This criterion considers impacts to community, site workers, and the environment during
construction and implementation and includes the time until protection is achieved.
During remediation, Alternatives 4, 5, and 9 protect the community and workers through the use
of engineered and institutional controls. However, Alternatives 4 and 5 would be more
protective because the waste would not be disturbed, there would be virtually no potential for
off-site migration of dust or other airborne contaminants. Short-term risks to the community
(not including transportation) and to nonremedial workers would be approximately egual and
within acceptable limits for all three alternatives. Risks to the community along the
transportation route and to workers during waste excavation and handling would be higher for
Alternative 9.
Short-term environmental effects associated with Alternatives 4 and 5 would be minor.
Alternative 9 would destroy approximately 6 ha (15 acres) of habitat and reguire relocation of a
state-listed plant species of special concern and mitigation for wetland destruction.
The duration of remedial activities for Alternatives 4 and 5 would be approximately the same, 4
months, with environmental enhancement actions continuing for up to 5 years. Maintenance and
surveillance actions would be reguired and CERCLA 5-year reviews would be performed until the
site no longer presents a hazard. Alternative 9 would reguire a remediation period of
approximately 4 years due to the time involved in waste removal. After the first 5-year review,
no further surveillance or maintenance would be expected for Alternative 9.
IMPLEMENTABILITY
Implementability is the technical and administrative feasibility of a remedy, including the
availability of materials and services needed to implement the chosen solution.
Alternatives 4, 5, and 9 are technically feasible to implement, although Alternative 9 would
involve greater amounts of time, eguipment, and activity. All three alternatives could be
performed using conventional eguipment and construction methods. Excavation of FCAP ash under
Alternative 9 would be moderately difficult because of the working conditions caused by the
unstable substrate (saturated ash). All other components of the three action alternatives would
be easy to implement.
Implementation of Alternatives 4 and 5 would not be subject to administrative barriers. The
administrative feasibility of Alternative 9 is moderately difficult because of the logistical
arrangements and documentation reguired for off-site disposal.
COST
The differences in cost, including capital costs and operation and maintenance (O&M) costs, are
expressed as estimated, total, present-worth cost for each alternative. Alternatives 4
and 5 are estimated at $4.3 and $4.6 million, respectively. Alternative 9 is estimated to be
more than an order of magnitude higher in cost at $65 million.
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STATE ACCEPTANCE
This criterion evaluates whether the state agrees with, opposes, or has no comment on the
preferred alternative. The state of Tennessee concurs with the selected remedy.
COMMUNITY ACCEPTANCE
Community acceptance addresses the issues and concerns the public may have regarding each of the
alternatives and the preferred alternative in particular. The proposed plan (Jacobs ER Team
1995b) presented Alternative 5, with minor modifications from the alternative described in the
FS, as the preferred alternative. The "Highlights of Community Participation" section
summarizes community participation. The selected remedy was not modified based on public
comments. The "Responsiveness Summary" in Part 3 provides comments submitted during the public
comment period and responses to these comments.
SEIiECTED REMEDY
Based on CERCLA reguirements, the comparative analysis of the alternatives presented in the FS
(Jacobs ER Team 1995a), and public comments, DOE, with the concurrence of EPA and the state of
Tennessee, has determined that the preferred alternative as presented in the proposed plan and
subseguently modified by agreement of all FFA parties is selected as the most appropriate remedy
for the FCAP OU. The modifications to the preferred alternative agreed to by the FFA parties
are summarized in the "Documentation of Significant Changes" section of this ROD because the
changes were made following closure of the public comment period. For simplicity and brevity,
the components of the selected remedy are rearranged here from the way they were presented in
the FS and proposed plan and in the description of alternatives previously presented in this
document. The selected remedy reflects the best balance of the evaluation criteria.
The RI risk assessment indicates a current risk to ecological receptors and the potential for
future risk to human and ecological receptors, particularly if the dam fails. The selected
remedy reduces risks by implementing institutional controls, environmental enhancements, surface
water controls, dam improvements and stabilization, and monitoring.
Institutional Controls. Institutional controls limit access to the site to (1) prevent
prolonged exposure of humans to contaminants, (2) control future development and disturbance of
the site, and (3) prevent destruction of engineered actions. Access to the site will be
confined to authorized personnel through the use of fencing, gates, and signs. Deed
restrictions or continued government ownership will limit access and use of the site, thereby
eliminating public exposure to on-property contamination.
Environmental Enhancements. A passive treatment system will be constructed to lessen migration
of contaminants from ash into surface water. First, the wetland at the toe of the dam will be
carefully excavated, and plants will be set aside for later relocation. Then construction of
the dam and spillway improvements will be performed promptly. An oxygenation area and a
settling basin will be constructed at the toe of the dam. Finally, the excavated wetland plants
will be relocated just downgradient of the small basin and upstream of the emergency spillway
outfall. The system will intercept and treat contaminated water seeping under the dam, reducing
contaminant levels in the surface water of Upper McCoy Branch. The system will be able to
remove metals by oxidation, sedimentation/precipitation, settling, filtration, and biological
processes similar to those occurring in the existing wetland. Contaminated sludge in the bottom
of the basin may be removed, if necessary, as determined by periodic inspections and review of
monitoring data. Any removed material would be sampled, characterized, and disposed of in an
approved facility.
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Dam Improvements and Stabilization. This component will modify the dam to bring it into
compliance with all requirements for existing dams of the Tennessee Safe Dam Act and will
include actions to satisfy appropriate requirements for new dams, although these are not ARARs
for this action. The entire outslope of the dam will be stabilized, if necessary, with a rock
buttress to provide enhanced structural stability. The crest elevation of the dam will be
raised to provide capacity for impoundment of stormwater behind the dam and to minimize erosion.
The spillway will be repaired by backfilling and compacting the spillway channel, increasing its
capacity to meet the requirements of the Tennessee Safe Dam Act, and protecting it from further
erosion. Trees will be removed from the dam and all voids filled with compacted soil to seal
the roots. A subsurface drain at the toe of the dam will be installed, if required, to control
seepage from and around the abandoned primary spillway pipe and the existing underdrain system.
Monitoring. Monitoring will verify the effectiveness of the remedial actions and provide the
basis for CERCLA 5-year review. A monitoring and surveillance plan will be developed during the
remedial design phase. Monitoring will consist of the following actions.
• Physical Surveillance and Maintenance-Scheduled periodic inspections will assess the
condition of the dam and emergency spillway. Scheduled maintenance actions will be
performed periodically and unscheduled maintenance will be performed, as required,
based on surveillance and monitoring findings.
• Monitoring-Surface water will be periodically sampled and characterized. These
monitoring results will be analyzed to verify that the passive treatment system
reduces contaminant levels in water entering Upper McCoy Branch at least as well as
the existing wetlands and to evaluate whether the passive treatment system requires
maintenance.
• CERCLA 5-Year Report-DOE will prepare a report for the postremediation, 5-year
review as required by CERCLA 121 (c) for remedial actions that leave waste in place.
Revisions to monitoring frequency, adding or eliminating remedial actions, and
determining if future 5-year reviews are necessary will be addressed, as
appropriate, in the report.
The estimated capital cost for the selected remedy is about $1,120,000 plus a 35 percent
contingency for a total of about $1,760,000. Monitoring and O&M costs for 30 years are
estimated at about $1,200,000 plus a 35 percent contingency for a total of about $1,620,000. A
breakdown of the projected cost components is provided in Table 2.1. These estimates were
developed by subtracting cost savings resulting from changes to the scope of action from the
cost estimates for comparison of the alternatives during preparation of the FS (Jacobs ER Team
1995a). The original FS cost estimates, together with modifications to the selected remedy, are
enumerated in the "Documentation of Significant Changes" section.
STATUTORY DETERMINATIONS
Section 121 of CERCLA establishes several statutory requirements and preferences, including
compliance with ARARs. Statutory requirements specify that, when complete, the selected remedy
must be cost-effective. It must use permanent solutions and innovative treatment technologies
or resource recovery technologies to the maximum extent practicable. Finally, the statute
includes a preference for remedies that use treatment that permanently and significantly reduces
the toxicity, mobility, or volume of hazardous substances.
PROTECTION OF HUMftN HEALTH AND THE ENVIRONMENT
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The selected remedy is protective of human health and the environment through continued
containment of the ash and reduction in the potential for exposure of humans and biota to the
ash.
COMPLIANCE WITH ARARs
All alternatives retained for detailed analysis in the FS report would meet all ARARs; the
selected remedy would meet or exceed all ARARs (Table 2.2).
Chemical-specific requirements set health- or risk-based concentration limits or discharge
limitations in various environmental media or else indicate a safe level of discharge that may
be considered for a remedial activity. Available ARARs and to-be-considered guidance for
radionuclides address only man-made, not naturally occurring, radionuclides. Therefore, no
ARARs for radionuclides are included in this decision document. Groundwater at the site would
be potential drinking water under current state classification (TDEC Rules, Chapter
1200-4-6.05). However, no unigue contaminants were identified as originating from FCAP and the
few contaminants in the groundwater (above background levels) did not exceed MCLs. Thus, no
action is being taken on groundwater at the OU.
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Table 2.1. Revised estimates for cost components of the modified selected remedy for
Chestnut Ridge Operable Unit 2' Oak Ridge, Tennessee
Project Cost Item
CAPITAL COSTS
Cost ($Thousands)2
Direct Cost:
Environmental enhancements
Access and use restrictions
Surface water controlsS
Dam controls (improvements, stabilization)4
Mobilization and demobilization
Direct Cost Total (rounded)
0
40
0
480
120
640
Indirect Cost:
Remedial design work plan
Remedial design report
Remedial action work plan
Remedial action integration
Contingency - 35 percent
Indirect Cost Total (rounded)
12
140
12
500
456
1,120
TOTAL CAPITAL COST
1,760
O&M COSTS
Environmental enhancements
MonitoringS
Contingency - 35 percent
0
1,200
420
TOTAL PROJECT ESCALATED COST6
TOTAL O&M COST
TOTAL PROJECT PRESENT WORTH7
1,620
3,380
1,450
lOriginally estimated for comparison purposes in the feasibility study and modified based on revised bases
of estimates.
2Escalated.
3Components eliminated as part of modification.
4Passive treatment system costs are included here as part of construction.
SOriginally included costs for groundwater monitoring.
6A11 costs were reduced as site- and remedy-specific data became available to replace initial conservative
assumptions made for the feasibility study cost estimate.
7Present value cost is based on 30-year present value, using a 6 percent discount rate.
Note: Costs presented in table are rounded.
O&M = operation and maintenance
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Table 2.2. ARARs/TBC guidance for the selected alternative for Chestnut Ridge Operable Unit,
Oak Ridge, Tennessee
Requirements Citatic
Chemical-sped fie
None
Location-specific
Whenever possible, actions must avoid or minimize adverse impacts on wetlands and act
to preserve and enhance their natural and beneficial values. New construction in wetlands
areas should be particularly avoided unless there are no practicable alternatives.
Wetlands protection considerations shall be incorporated into planning, regulating, and
decision-making processes - applicable
Action to avoid degradation or destruction of wetlands must be taken to the extent
possible. If adverse impacts are unavoidable, action must be taken to enhance, or create
alternative wetlands. - applicable to actions involving discharge of dredge or fill material
into wetlands
Floodplains
Within "lowland and relatively flat areas ad-
j oining inland and coastal waters and other
floodprone areas such as offshore islands,
including at a minimum, that area subj ect to a
one percent or greater chance of flooding in
any given year." [Executive Order 11988
§6(c)]
Within areas encompassing or affecting waters
of the state of Tennessee, as defined in TCA
69-3-103(32), and the presence of wildlife or
aguatic life
Action shall be taken to reduce the risk of flood loss, minimize the impact of floods on
human safety, health and welfare, and restore and preserve the natural and beneficial
values of floodplains - applicable
The potential effects of actions in floodplains shall be evaluated and consideration of
flood hazards and floodplain management ensured - applicable
If action is taken in floodplains, alternatives that avoid adverse effects and incompatible
development and minimize potential harms shall be considered- applicable
Tennessee Water Quality Control
Act of 1977 [TCA 69-3-102(b)]
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Table 2.2. (continued)
Requirements
Within area encompassing aquatic ecosystem
with dependent fish, wildlife, or other aquatic
life or habitat
Degradation of destruction of aquatic ecosystems must be avoided to the extent possible.
Discharges that cause or contribute to significant to significant degradation of the water of such
ecosystems are prohibited. - applicable to any action involving the discharge of dredge or
fill material into an aquatic ecosystem
The effects of water-related projects on fish and wildlife resources must be considered.
Action must be taken to prevent, migrate, or compensate for project-related damages or
losses to fish and wildlife resources - applicable
Fish and Wildlife Coordination
Act (16 USC 661 et seq.)
Protected species (i.e., endangered species) may not be uprooted, dug, taken, removed,
damaged or destroyed, possessed, or otherwise disturbed for any purpose - relevant and
appropriate to "species of special concern" present at the site
Tennessee Rare Plant Protection
and Conservation Act of 1985
(TCA 11-26-201 et seq.)
Actions involving alteration of terrain which
might cause irreparable loss or destruction of
significant scientific prehistoric, historic, or
archaeological resources
The Secretary of Interior must be advised of the presence of the data. A survey of
affected areas for resources and data must be conducted and steps taken to recover,
protect, and preserve data therefrom or request that DOI do so - applicable if action;
impact any such identified resources
Archaeological and Historic Pres-
ervation Act of 1974 (16 USC
4 69a-c)
Actions impacting any archaeological resources
Steps must be taken to protect archaeological
resources and sites - applicable if actions
Archaeological Resources Protection public land
(i.e., within the ORR impact any
such identified resources
tion Act of 1979 (16 USC 470aa-
boundaries)
II)
43 CFR
Actions impacting any federally owned, admin-
istered, or controlled prehistoric or historic
resources -or- the likelihood of undiscovered
resources
Consultation should be initiated with the SHPO and Advisory Council on Historic
Preservation before the initiation of any groundbreaking activities to determine the need
for any additional archaeological or historic survey work and the need for an MOA
regarding protection of archaeological resources - applicable
Dams
Actions involving/impacting construction or
modification of a dam as defined in TCA
69-12-102 (3)
Tennessee Safe Dam Act of 1973
(TCA 69-12-101 to -125);
TDEC 1200-5-.06
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Table 2.2. (continued)
Requirements
Stability - all dams shall be stable
Slope protection - earth embankments shall be protected from surface erosion by
appropriate vegetation or some other type protective surface such as riprap or paving
and shall be maintained; all inappropriate vegetation shall be removed from the dam
Emergency spillway - All dams shall have an emergency spillway system with capacity
to pass a flow resulting from a 6-hour design storm for a hazard classification appropri-
ate for the dam, or
If applicant can success fully demonstrate by engineering analysis that the dam is a safe
structure and is sufficient to protect against probably loss of human life downstream,
dam design can be approved by the Commissioner.
Action-specific
Take reasonable precautions to prevent particular matter from become airborne; no
visible emissions are permitted beyond property boundary lines for more than 5 min/hour
or 20 min/day - applicable
Activities are authorized under Nationwide Permit (NWP) 18 (Minor Discharges), NWP
26 (Headwaters and Isolated Waters Discharge), NWP 27 (Wetland Restoration and
Creation Activities), and NWP 38 (Cleanup of Hazardous and Toxic Waste) provided that:
Releases of airborne radionuclides during
construction, remediation, or transport
activities
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Table 2.2. (continued)
Requirements
General public exposure, all sources - TBC
100 mrem/year EDE
Temporary exemption, maximum limit - TBC
500 mrem/year EDE
DOE Order 5400.5, II.la
! document BMP's in a stormwater control plan or equivalent document
! minimal clearing for grading
! removal of vegetation cover only within 20 days of construction
! perform weekly erosion control inspections and maintenance
! control measures to detain runoff
! discharges must not cause erosion
Institutional controls shall be required for all areas where containment is a remedial
action; controls shall include, at a minimum, deed restrictions for sale and use of
property, and securing the area to prevent human contact with hazardous substances -
applicable
Operator of a Class II solid waste disposal facility must close the facility in a manner
that:
(1) minimizes the need for further maintenance; and (2) controls, minimizes, or elimi-
nates , to the extent necessary to prevent threats to public health and the environment,
post closure escape of solid waste, solid waste constituents, leachate, contaminated
rainfall, or waste decomposition products to the ground or surface waters to the atmo-
sphere - relevant and appropriate to unpermitted solid waste disposal facilities
ARAR = applicable or relevant and appropriate requirements
BMP = best management practice
CFR = Code of Federal Regulations
DOE = U.S. Department of Energy
DOI = U.S. Department of Interior
EDE = effective dose equivalent
min = minute
MOA = memorandum of agreement
mrem = millirem
ORR = Oak Ridge Reservation
SHPO = state historic preservation officer
TBC = to be considered
TCA = Tennessee Code Annotated
TDEC = Tennessee Department of Environment and Conservation
USC = United States Code
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Contaminants in leachate from FCAP contribute to existing pollution in surface waters of the
Upper McCoy Branch. The Tennessee Water Quality Control Act of 1997, whose purpose is to "abate
existing pollution... [and] reclaim polluted waters..." [TCA69-3-102.(b)], is cited as an ARAR
for this reason. The goal of this remedial action is to abate this pollution through
enhancement of the passive treatment system where leachate exists at the toe of the dam.
Little legislation or guidance governing cleanup of contaminated soils or sediments at CERCLA
sites is available. Since coal ash is not a RCRA hazardous waste, none of the Subtitle C RCRA
regulations, including land disposal restrictions and the proposed RCRA rules addressing
hazardous soils, are ARARs.
Location-specific ARARs include reguirements to avoid or minimize adverse impacts to wetlands.
If such impacts cannot be avoided, mitigation and compensation are reguired. The selected
remedy involves relocating a small, existing wetland approximately 61 m (200 ft) downgradient
from its current location. The disturbance may be unavoidable if the dam is improved and the
spillway is repaired. A wetlands delineation and wetlands assessment were completed per 10 Code
of Federal Regulations (CFR) 1022 and in consultation with the U.S. Army Corps of Engineers as
part of the FS. The substantive reguirements of a wetlands mitigation plan (as identified in
the FS) will be incorporated into the remedial design work plan and approved by DOE, with the
concurrence of EPA and the state of Tennessee, before activities in the wetlands begin.
Since the remedial action will occur within a floodplain, actions must minimize any adverse
impacts. A Notice of Floodplain and Wetland Involvement was published for investigative and
remedial actions on the ORR October 4, 1993 (58 FR 51624) . A floodplain delineation and
assessment was completed as part of the FS.
A homestead was identified in the Sluice Channel Area during the RI. It was evaluated during
the FS for eligibility for listing as a historic resource in consultation with the state
historic preservation officer (SHPO). The SHPO concurred with DOE that the homestead was not
eligible for listing in the National Register of Historic Places, and the consultation was
completed. No mitigation would be reguired for the homestead. Location-specific ARARs related
to cultural resources would be invoked only if discoveries of additional potential cultural
resources were made fluting remedial activities.
A small population of lesser ladies tresses orchids (Spiranthes ovalis), a state-listed species
of special concern was identified at the site during a survey of the OU and surrounding area for
threatened and endangered plants (Cunningham 1993). The selected remedy is not expected to
impact these plants; however, should any actions be taken upgradient of the dam, several
location-specific ARARs would be triggered, reguiring protection and mitigation for these
plants.
Dams in Tennessee are subject to periodic inspection and certification under the Tennessee Safe
Dams Act of 1973, as amended July 1989 (TCA Sect. 69-12-101 et seg.). These regulations [TDEC
1200-5-7.02(32)] do not legally apply to the U.S. government. However, the substantive
reguirements of the regulations for existing dams are relevant and appropriate to this action.
TDEC 1200-5-7.06 lists standards for existing dams, and addresses stability, slope protection,
and emergency spillways. Compliance with these regulations may be achieved by meeting the
specifications enumerated in the regulations or by gaining the approval of the FFA parties. The
selected remedy will bring the dam into compliance with all specifications for existing dams and
will voluntarily meet some of the specifications for new dams, although these are not ARARs.
Action-specific ARARs for remedial action at FCAP include reguirements for surface water
controls during remediation and site planning to minimize adverse effects from erosion and
stormwater discharges into the creek which could result from activities such as grading,
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clearing, and excavation. Best management practices will be followed to minimize the potential
release of hazardous substances into surface waters (40 CFR 125.104), to control stormwater
discharges (40 CFR 122, TDEC 1200-4-10-.05), and for nonpoint source controls (TDEC
1200-4-3-.06). These practices would comply with the substantive requirements of the aguatic
resources alteration and stormwater permitting process (TDEC 1200-4-10-.05, TDEC 1200-4-7 et
seg.). Precautions must also be taken to prevent fugitive dust from becoming airborne (TDEC
1200-3-8-.01). Since substantive rather than administrative reguirements must be followed, it
should be possible to combine these reguirements into one best management plan for the project
which also incorporates the wetland and floodplain mitigation measures discussed previously.
TDEC Class II solid waste disposal general performance reguirements for closure with waste in
place are relevant and appropriate for the selected remedy. Reguirements include minimizing the
need for further maintenance and minimizing the escape of solid waste and leachate, which could
pose threats to public health and the environment. These reguirements will be met by repairing
the dam and constructing the passive treatment system.
COST EFFECTIVENESS
Actions taken under CERCLA must consider the estimated total present-worth costs of the
alternatives. Alternatives 4, 5, and 9 in the FS meet the regulatory reguirements and reduce
risk to human health and the environment to acceptable levels. Alternative 5, with an estimated
cost of $4.6 million, is less than 7 percent more costly than Alternative 4 and provides for
greater stability of the dam. Alternative 9 is more than 10 times as costly as Alternative 5.
Alternative 5 is, therefore, considered the most cost-effective remedy for the protection of
human health and the environment.
USE OF PERMANENT SOLUTIONS TO THE MAXIMUM EXTENT PRACTICABLE
DOE believes the selected remedy represents the maximum extent to which permanent solutions can
be used in a cost-effective manner for FCAP. Of the remediation alternatives, DOE believes the
selected remedy provides the best balance of trade offs in terms of long-term effectiveness and
permanence; reduction of toxicity, mobility, or volume through treatment; short-term
effectiveness; implementability; and cost.
PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
The coal ash in FCAP is not regulated as a hazardous waste. Some toxic constituents in the ash
have limited mobility through leaching into surface water. Treatment of the ash to reduce
volume would reguire dewatering. Dewatering would produce a large liguid waste stream and would
not necessarily reduce the mobility of the residual hazardous constituents. Treatment of the
large volume of ash to reduce toxicity or mobility would increase volume significantly, and the
costs are not commensurate with the slight reduction of risk that would be achieved.
The passive treatment system at the toe of the dam is expected to effectively reduce the
mobility and bioavailability of the contaminants leached from the dam. The system should egual
or exceed the reduction in contaminant concentrations in surface water currently occurring in
the natural wetland.
DOCUMENTATION OF SIGNIFICANT CHANGES
The preferred alternative in the proposed plan included minor refinements to Alternative 5 of
the FS (i.e., deletion of surface water diversions upgradient of FCAP). The surface water
diversions were eliminated because of uncertainties about their effectiveness in reducing
contaminant migration, the potential for adverse effects on wildlife habitat and wetlands
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resulting from implementation, and difficulty in justifying installation and maintenance costs
for the diversion structures. The determination to eliminate that component is documented in
the administrative record in a May 30, 1995, letter to DOE (Jacobs ER Team 1995c).
Subseguently, additional changes were agreed to by the FFA managers during a December 6, 1995,
meeting. The managers reviewed several components of the selected remedy at DOE's reguest. The
revisions incorporated into the selected remedy are based on regulator comments, a regulatory
decision by the state that the structure at FCAP is a dam, and comments raised during the FFA
managers meeting. The resulting changes included eliminating implementation of portions of the
environmental enhancements. Design reguirements for the emergency spillway were also discussed
during the FFA managers meeting.
Portions of the environmental enhancements component of the selected remedy, which will not be
implemented, include adding nutrients and organic amendments to FCAP soils, planting preferred
wetland species at the OU, and placing man-made salt licks on site for deer and other animals
use. The managers concurred that there is not a specific regulatory driver for these measures,
and current funding constraints within the DOE Environmental Restoration Program argued against
their implementation.
Groundwater monitoring was also eliminated from the project as a result of a comment from the
state during review of the draft (Dl version) ROD. There was not a specific regulatory driver
mandating groundwater monitoring because the remedial action does not include action on
groundwater. These changes to the selected remedy will result in cost savings. The difference
between the original cost estimates prepared for comparison of the alternatives in the FS and
the estimated costs for the remedy, as it will now be implemented, are presented in Table 2.3.
Regulations for the Tennessee Safe Dam Act include guidance for the design of an emergency
spillway with a capacity of 1/3 PMP. This was believed to be overly conservative for FCAP, and
an alternate design may be approved by the state administrator of the dam program. DOE, EPA,
and TDEC agreed that a design storm event suitable under best engineering management practices
will be approved before remedial design. This is also expected to result in cost savings, which
cannot be estimated at this time.
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Table 2.3. Cost components of the selected remedy for Chestnut Ridge OU 2, and as
presented in the FS for Alternative 5', Oak Ridge, Tennessee
Project cost item Cost ($Thousands) 2
CAPITAL COSTS
Direct Cost: FS Estimate Revised Estimate
Environmental enhancements 24 0
Access and use restrictions 96 40
Surface water controlsS 360 0
Dam controls (improvements, stabilization)4 480 480
Mobilization and demobilization 280 120
Direct Cost Total (rounded) 1,200 640
Indirect Cost:
Remedial design work plan 22 12
Remedial design report 280 140
Remedial action work plan 21 12
Remedial action integration 810 500
Contingency - 35 percent 830 456
Indirect Cost Total (rounded) 2,000 1,120
TOTAL CAPITAL COST 3,200 1,760
O&M COSTS
Environmental enhancements 1,300 0
MonitoringS 4,300 1,200
Contingency - 35 percent 1,900 4.20
TOTAL O&M COST 7,500 1,620
TOTAL PROJECT ESCALATED COST6 10,700 3,380
TOTAL PROJECT PRESENT WORTH7 4,600 1,450
lOriginally estimated for comparison purposes in the feasibility study and modified based on revised bases
of estimates.
2Escalated.
3Components eliminated as part of modification.
4Passive treatment system costs are included here as part of construction.
SOriginally included costs for groundwater monitoring.
6A11 costs were reduced as site- and remedy-specific data became available to replace initial conservative
assumptions made for the feasibility study cost estimate.
7Present value cost is based on 30-year present value, using 6 percent discount rate.
Note: Costs presented in table are rounded. FS = feasibility study
O&M = operation and maintenance
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REFERENCES
CDM (CDM Federal Programs Corporation). 1995. Remedial Investigation Report on Chestnut
Ridge Operable Unit 2 (Filled Coal Ash Pond/Upper McCoy Branch) at the Oak Ridge Y-12
Plant, Oak Ridge, Tennessee, DOE/OR/01-1268/V1&D2. Prepared for U.S. Department of
Energy, Oak Ridge, TN.
Cunningham, M., et al. August 1993. Resource Management Plan for the Oak Ridge Reservation,
Volume 29: Rare Plants on the Oak Ridge Reservation, Martin Marietta Energy Systems, for
the Oak Ridge Reservation Resource Management Organization and Oak Ridge National
Environmental Research Park-Office of Health and Environmental Research, ORNL/NERP-7. Oak
Ridge, TN.
Energy Systems (Martin Marietta Energy Systems, Inc.). 1993. Background Soil Characterization
Project for the Oak Ridge Reservation, DOE/OR/01-1174/V1 and Appendixes DOE/OR/01-1175/V2.
Oak Ridge, TN.
EPA (U.S. Environmental Protection Agency). 1990. Role of the Baseline Risk Assessment in
Superfund Remedy Selection Decisions, OSWER Directive 9355.0-30.
Jacobs ER (Environmental Restoration) Team. 1995a. Feasibility Study for the Y-12 Chestnut
Ridge Operable Unit 2, Filled Coal Ash Pond, Oak Ridge, Tennessee, DOE/OR/02-1259&D2.
Prepared for U.S. Department of Energy, Oak Ridge, TN.
Jacobs ER Team. 1995b. Proposed Plan for Chestnut Ridge Operable Unit 2 (Filled Coal Ash Pond
and Vicinity), Oak Ridge, Tennessee, DOE/OR/02-1329&D2. Prepared for U.S. Department of
Energy, Oak Ridge, TN.
Jacobs ER Team. 1995c. "Justification for Removing Surface Water Diversions from the Preferred
Alternative for the Y-12 Chestnut Ridge Operable Unit 2 Filled Coal Ash Pond,"
JE/OR/95-00708. Letter from Sheldon Meyers, Program Manager, Jacobs ER Team, to Wendell
Mansel, U.S. Department of Energy, Oak Ridge, TN.
Radian. 1993. Environmental Restoration Program, Chestnut Ridge Operable Unit 2, Technical
Summary, Draft, D93-132KG51. Prepared for U.S. Department of Energy under contract
DE-AC05-900R21851.
Welch, S. H. 1989. RCRA Facility Investigation Plan General Document Y-12 Plant, Oak Ridge,
Tennessee, Vol. 1, Rev. 1. Y/TS-352. Martin Marietta Energy Systems, Inc., Oak Ridge, TN.
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PART 3. RESPONSIVENESS SUMMARY
This "Responsiveness Summary" documents the public comments on the Proposed Plan for Chestnut
Ridge Operable Unit 2 (Filled Coal Ash Pond and Vicinity), Oak Ridge, Tennessee (Jacobs ER Team
1995b). The proposed plan was issued in June 1995. The public comment period started July 5,
1995, and ended August 5, 1995. DOE announced the availability of the proposed plan in a public
notice published in The Knoxville News-Sentinel July 5, 1995. The public notice advised that
the proposed plan would be one of the topics discussed at the guarterly stakeholders meeting
July 18, 1995, and that a formal public meeting would be arranged if reguested. This document
addresses the informal comments made by the public during the July 18, 1995, stakeholders
meeting and telephone and written comments received during the public comment period.
This "Responsiveness Summary" serves three purposes. First, it informs DOE, EPA, and TDEC of
community concerns about the site and the community's preferences regarding the proposed
remedial alternative. Second, it demonstrates how public comments were integrated into the
decision-making process. Finally, it allows DOE to formally respond to public comments.
This summary is prepared pursuant to the terms Of the 1992 FFA among DOE, EPA, and TDEC, as well
as other reguirements, including:
CERCLA as amended by SARA, 42 USC, Section 9601, et seg. ;
NCP, 40 CFR 300.430; and
Community Relations in Superfund, A Handbook, EPA/540/R-92/009.
COMMENTS FROM QUARTERLY STAKEHOLDERS MEETING
No formal transcripts were made at the guarterly stakeholders meeting and no formal public
meeting was reguested. Although individuals making comments did not identify themselves, the
Chestnut Ridge OU 2 issues raised at the stakeholders meeting were recorded. DOE's responses to
those issues follow.
ISSUE 1: WHAT ARE THE CONSTITUENTS PRESENT IN THE COAL ASH? HOW DO THEY DIFFER FROM OTHER COAL
ASH? DO ALL OTHER ASH DISPOSAL SITES NEED THE REMEDIATION PROPOSED HERE?
Response: The constituents in the FCAP ash are typical of constituents in ash from combustion
of eastern United States coal. None of the constituents present at the FCAP were out of
concentration ranges typical for eastern coal; the median values at the FCAP were comparable to
median values for other coal. The constituents and their concentrations are presented in Table
1.3 of the FS Report and are based on FCAP sampling results and published literature values
(Jacobs ER Team 1995a).
Coal ash is regulated as a solid waste under RCRA. It is exempted from being a hazardous waste,
but facilities with coal ash must comply with storage and disposal reguirements for solid waste.
These facilities would not normally reguire remediation due to the presence of the ash. When
ORR was placed on the NPL, SWMUs, including FCAP, were evaluated under CERCLA guidelines to
determine whether they pose unacceptable risks to human health and the environment. The ash at
FCAP was found to pose such risks largely because it had been placed behind a dam and situated
above a natural water body (a small creek). This presents a risk of dam failure and release of
the ash under circumstances not present at other sites. In addition, the site conditions are
more conducive for transport of the constituents into the environment than at other sites.
Thus, remediation of this site is appropriate and reguired under CERCLA, but may not be reguired
at other coal ash disposal sites.
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ISSUE 2: ARE THE COSTS FOR THIS PROJECT JUSTIFIED? CAN THE MONEY PROPOSED FOR THIS PROJECT BE
BETTER USED ELSEWHERE?
Response: Compared to many other potential remedial actions on the ORR, the cost for this
action is small. Although the "no action" alternative assumes that the site is abandoned and
there is zero cost, significant expenditures for existing and planned monitoring and maintenance
programs would be incurred even if remedial actions were not taken at the site. Over a 30-year
period, only a slight reduction from the $5.6 monitoring and O&M costs projected for
Alternatives 4 and 5 and the selected remedy would be expected. In addition, the most
significant risk results from possible failure of the dam and release of the ash. This would
not pose a large human health safety risk, because the area is occupied by people only rarely.
Failure of the dam and release of the ash would, however, significantly damage the local
environment and reguire cleanup at a cost many times the proposed capital remediation cost. DOE
feels that the project costs are justified because (1) the incremental cost of the project above
already committed expenditures is small, (2) remediation is needed to meet regulatory
reguirements, and (3) the remediation could prevent greater expenditures in the future.
ISSUE 3: COAL ASH IS SOLD AS A RESOURCE. HAS RESALE OF THE ASH BEEN CONSIDERED TO REDUCE COSTS
OR TO MAKE A PROFIT FROM REMEDIATION OF THE SITE?
Response: Resale of the ash for industrial use was investigated in a draft Environmental
Restoration Program, Chestnut Ridge Operable Unit 2, Technical Summary (Radian 1993) and
eliminated from further consideration. The ash in the FCAP consists of both fly ash and bottom
ash. Due to placement methods and its exposure to the environment for decades, the ash is mixed
with soil and sediment. Resale at a profit to users of low volumes of high guality ash (e.g.,
for metal or mineral extraction or as a concrete or asphalt additive) is not possible because
the ash would not be accepted without significant treatment and analysis to produce and
guarantee a homogeneous product that meets the users specifications. Reuse for high volume, low
technology applications (e.g., road base and subbase or structural fill) would reguire
excavation and transport of the ash. Transport would be either as a slurry (reguiring the
addition of water) or as solid granular material (reguiring dewatering). The material would
have to be dewatered before use. If users could be found, they would likely accept the material
at no charge, rather than pay a fee for receipt of the material. Thus, disposal costs could be
avoided, but excavation, dewatering, transportation, and environmental restoration costs would
still be incurred. There would be significant, adverse short-term effects on the environment
during and after the excavation process. The overall cost of reuse would, therefore, be similar
to Alternative 9 in the FS with the elimination of the disposal fees ($65 million less $5
million = about $60 million). This remedy would actually be more costly than the selected
remedy and would cause adverse environmental effects.
ISSUE 4: ARE THERE MATERIAL SAFETY DATA SHEETS THAT DESCRIBE THE HAZARDS ASSOCIATED WITH COAL
ASH?
Response: Coal ash is a combustion by-product of a naturally occurring energy source (raw
material). It is not classified as a hazardous waste under RCRA (although there are low
concentrations of hazardous constituents in the ash), and no Material Safety Data Sheets (MSDSs)
are available. MSDSs are provided by chemical and other material manufacturers to purchasers of
the manufactured material. They describe components of the material sold and the reguirements
for safe handling, use, and disposal of hazardous materials. As stated, coal ash is the result
of combustion of a natural, as opposed to manufactured, product. The risks to human health
associated with the FCAP ash were calculated based on certain residential and trespasser
scenarios that consider long-term exposure to or ingestion of the ash or its leachate in
accordance with EPA and CERCLA protocols. These risks and risks to environmental receptors were
determined to be unacceptable, as explained in Issue 1. Institutional Control is the lowest
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cost remedial action that will mitigate the risks to human health. Because the scenarios
leading to unacceptable human health risks are considered unlikely, institutional controls are
the only actions in the selected remedy designed to reduce human health risk. The other actions
in the selected remedy address potential catastrophic failure of the dam and reduction of the
risks to environmental receptors.
WRITTEN COMMENTS
Three written comments were received. Two of the comments and DOE responses to them follow.
The third comment by W. L. McCullough is similar to Issue 3, which is discussed on page 3-4,
and is not included here.
COMMENT 1. Fred F. Haywood
"This proposed plan fails to demonstrate that the FCAP and vicinity poses a significant threat
to human health and the environment. In this case, the only action which can be justified is
stabilization of the dam to prevent catastrophic failure. Risk associated with 228Th represents
only a portion of the total potential exposure due to gamma-rays. Radionuclides in the uranium
decay chain are also present in the ash. However, protection of the public from this radiation
source, or the need for it is poorly justified."
Response: Radionuclides evaluated as COPCs in the RI (Tables 5-1 .a, b, and c; Tables 5.3
through 5.5) included risk contributions from 228Th, 230Th, 232Th, 234Th, 234U, 235U, 238U, and
137Cs. These contaminants were evaluated for trespasser and residential scenarios for
inhalation of dust, external radiation exposure, incidental ingestion of soil, and ingestion of
homegrown vegetables. External radiation exposure from 228Th, with a risk greater than 1 x 104
under the residential scenario, was the only radionuclide that exhibited a risk greater than 1 x
10-6. Therefore, 228Th was the only radionuclide retained as a relevant contaminant of concern
(COG) and discussed in the proposed plan. Assuming continued DOE ownership of the property and
access restrictions to the site, DOE agrees that there is little current or future risk to human
health from exposure to radioactivity or other constituents in the ash. DOE also agrees that
stabilization of the dam to prevent catastrophic failure is justified. CERCIA reguires not only
protection of human health, but also protection of the environment from the risks resulting from
site contaminants. There is a potential risk to sensitive ecological receptors, which could
result from contact with or ingestion of surface waters in Upper McCoy Branch contaminated by
the ash or its leachate. There are existing, documented risks to on-site terrestrial biota from
contact with or ingestion of the ash, plant uptake of ash constituents, and plant ingestion
resulting in bioaccumulation of ash constituents in animals. Stabilization of the darn and
protection of the ecological receptors are the drivers for the proposed actions. Other than
continued institutional control through DOE ownership of the land, no actions are proposed to
protect the public from exposure to radiation.
Dam stabilization is, by far, the most costly portion of the capital expenditures for remedial
action. The dam stabilization actions will probably destroy a portion of the existing wetlands
at the foot of the dam. Under current law, DOE would be obligated, at a minimum, to replace
those wetlands. DOE has chosen to provide the reguired replacement wetlands in conjunction with
environmental enhancements designed to reduce risk to ecological receptors in Upper McCoy
Branch. The cost of the replacement wetlands is small compared to the cost of dam
rehabilitation, and the additional cost of incorporating a passive treatment system into the
wetland replacement is an insignificant part of the total project cost. Another small cost will
be incurred for placement of salt licks for deer and addition of nutrients (i.e., fertilizer)
and organic matter (e.g., sewage sludge, compost, or manure) to the ash pond to enhance recovery
of the habitat, reduce plant uptake of constituents in the ash, and reduce exposure to and
ingestion of the ash by wildlife.
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As described for Issue 2, the most significant cost element for this project is for continued
monitoring and O&M actions. Most of this cost would be incurred regardless of the scope of
remedial actions. Because the incremental costs of the remedial actions to protect the
environment are small compared to the construction costs for dam rehabilitation and the
continued monitoring and O&M costs, DOE feels that the actions described in the selected remedy
are justified.
COMMENT 2 . William A. Goldsmith
"The only component of Alternative 4 or Alternative 5 that would control radiation exposures
from the ash pile is the component that restricts access. This component costs nothing. The
proposed plan fails to demonstrate how Alternative 4 or Alternative 5 would control risks.
Risks other than those attributable to 228Th are poorly identified. Risks attributable to 228Th
are not distinctly different from those that may be attributable to natural background
radiation. No expenditure for remediation is warranted based on the information provided in
this proposed plan."
Response: As discussed in the response to Comment 1, DOE agrees that the human health risks
from exposure to radiation are unlikely and do not warrant remediation other than continued
institutional controls. As discussed in the responses to Comment 1 and Issue 2, the drivers for
remediation of this site are the control of ecological risks and the prevention of catastrophic
failure of the dam to reduce the likelihood of greater expenditures in the future. DOE feels
that the expenditures to mitigate these risk drivers are justified.
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