EPA/ROD/R04-95/234
September 1995
EPA Superfund
Record of Decision:
US DOE Oak Ridge Reservation
Lower East Fork Poplar Creek OU, TN
8/17/95
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DOE/OR/02-1370&D2
Record of Decision
for
Lower East Fork Poplar Creek
Oak Ridge, Tennessee
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DOE/OR/02-1370&D2
Record of Decision
for
Lower East Fork Poplar Creek
Oak Ridge, Tennessee
Date Issued—July 1995
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 Lower East Fork Poplar Creek, Oak Ridge,
Tennessee (DOE/OR/02-1370&D2) was prepared in accordance with
requirements 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
1.4.12.3.1.04 (Activity Data Sheet 9304, "Lower East Fork Poplar
Creek"). This document provides the Environmental Restoration
Program with information about the selected remedy for Lower East
Fork Poplar Creek, which involves excavating floodplain soil with
mercury concentrations > 400 parts per million and disposing of the soil
at a landfill at the U.S. Department of Energy Oak Ridge Y-12 Plant.
Information in this document summarizes information from the remedial
investigation (DOE/OR/02-1119&D2&V1 and V2), the feasibility study
(DOE/OR/02-1185&D2&V1 and V2), and the proposed plan
(DOE/OR/02-1209&D3).
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ACRONYMS AND ABBREVIATIONS
ARAR applicable or relevant and appropriate requirement
ATSDR Agency for Toxic Substances and Disease Registry
°C degrees Celsius
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act of
1980
CFR Code of Federal Regulations
cm centimeter
DNA deoxyribonucleic acid
DOE U.S. Department of Energy
EFPC East Fork Poplar Creek
EPA U.S. Environmental Protection Agency
°F degrees Fahrenheit
FFA Federal Facility Agreement
ft foot
g gram
ha hectare
in. inch
kg kilogram
km kilometer
Ib pound
LOAEL lowest observed adverse effect level
m . meter
mg milligram
NEPA National Environmental Policy Act
NOAA National Oceanic and Atmospheric Administration
NOAEL no observed adverse effect level
NPL National Priorities List
OREPA Oak Ridge Environmental Peace Alliance
ORNL Oak Ridge National Laboratory
ORR , Oak Ridge Reservation
.OU operable unit . .
oz ounce
PAH polycyclic aromatic hydrocarbon
PCB polychlorinated biphenyl
ppm parts per million
RfD reference dose
SARA Superfund Amendments and Reauthorization Act of 1986
TDEC Tennessee Department of Environment and Conservation
Y-12 Plant Oak Ridge Y-12 Plant
yd yard
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PART 1. DECLARATION
JT93Q328.2DH/SDD July 28, 1995
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SITE NAME AND LOCATION
U.S. Department of Energy
Lower East Fork Poplar Creek Operable Unit
Oak Ridge Reservation
Oak Ridge, Tennessee
STATEMENT OF BASIS AND PURPOSE
This record of decision (ROD) presents the selected remedial action for Lower East Fork
Poplar Creek (EFPC) 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 Section 9601 et seq. and, to the extent practicable, the National Oil and Hazardous
Substance Contingency Plan.
This decision is based on the administrative record for Lower EFPC, including the-
remedial investigation report (DOE 1994a), the baseline risk assessment, the feasibility study
report (DOE 1994b), the addendum to the remedial investigation (DOE 1994c) that includes the
sediment toxicity special study, the proposed plan (DOE 1995b), and other documents contained
in the administrative record file for this site. - .
This document is issued by the U.S. Department of Energy (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 response action, and they concur with the selected remedy.
ASSESSMENT OF THE SITE
If releases of hazardous substances from this site are not addressed, they present an
unacceptable risk to public health, welfare, or the environment.
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DESCRIPTION OF THE SELECTED REMEDY
This response action fits into the overall Oak Ridge Reservation (ORR) cleanup strategy
by addressing floodplain soil, sediment, and groundwater contaminated by mercury originating
from the DOE Oak Ridge Y-12 Plant (Y-12 Plant). Lower EFPC surface water is not within the
scope of this ROD, but is discussed for informational purposes only. The objective of this
remedial action is to minimize the risk to human health and the environment from mercury-
contaminated soil in the Lower EFPC floodplain pursuant to CERCLA and the FFA (1992).
The selected remedy addresses the principal threats at the site by excavating and disposing
of the identified floodplain soils contaminated above the remediation goal of 400 ppm mercury.
The major components of the selected remedy include:
• excavating identified floodplain soils with mercury concentrations greater than 400
ppm from four areas. [Three of the areas are at the National Oceanic and
Atmospheric Administration (NOAA) site (two areas in Parcel #571 and one area in
Parcel #461), and the other area is at the Bruner's Center site (Parcel #564). The in
situ volume to be excavated is estimated to be 7,650 m3 (10,000 yd3)]. Confirmatory
sampling conducted before the remedial action will further refine the areas to be
excavated;
• disposing of contaminated soil in a permitted landfill at the Y-12 Plant;
• performing confirmatory sampling in the excavated areas to ensure all mercury
concentrations above 400 ppm have been removed;
• backfilling the excavated areas, including the 0.24-ha (0.6-acre) wetland at the
Bruner's Center site, with clean borrow soil and vegetating appropriately; and
• appropriate monitoring on Lower EFPC to ensure effectiveness of the remediation.
Groundwater and sediment do not present an unacceptable risk to human health and the
environment. If sufficient quantities of groundwater could be extracted from the shallow soil
horizon [0-6 m (0-20 ft)] for residential use, such groundwater could pose an unacceptable risk.
However, because residential use of shallow soil horizon (shallow) groundwater is not realistic
(as explained in more detail in the Decision Summary), groundwater is not considered to pose
an unacceptable risk. As a safeguard, DOE will monitor to detect any future residential use of
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shallow groundwater. In the unlikely event such use is detected, DOE will mitigate, as
appropriate, any risks associated with such use.
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. However, because treatment of the soils, which pose the principal threat at the site,
was not found to be practicable, this remedy does not satisfy the statutory preference for
treatment as a principal element of the remedy. This remedy will result in remediation of
hazardous substances and allows unlimited use of, and unrestricted exposure to, the Lower EFPC
Operable Unit (OU).
APPROVALS
James Hall, Manager Date
U.S. Department of Energy
Oak Ridge Field Office .
Earl Leming.Director <— Date
DOE Oversight Division
Tennessee Department of Environment and Conservation
John H. Hankinson, Jr., Regional Administrator Date
U.S. Environmental Protection Agency
Region IV
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PART 2. DECISION SUMMARY
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SITE LOCATION AND DESCRIPTION
ORR is in Oak Ridge, Tennessee, approximately 32 km (20 miles) west 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.
The Lower EFPC OU site includes the soil, sediment, and groundwater in the 100-year
floodplain along Lower EFPC and the Sewer Line Beltway (Fig. 2.1). More than 20 tributaries
and treated effluent from the Oak Ridge Sewage Treatment Plant flow into the creek. EFPC
begins within the Y-12 Plant as the Upper EFPC. Upper EFPC is a separate OU with
contamination and is addressed independently of this action. The Upper EFPC OU terminates
at Lake Reality, a retention pond at the eastern end of the Y-12 Plant.
The Lower EFPC OU begins at the outfall of Lake Reality at creek kilometer 23.3 (creek
mile 14.5) and ends at its confluence with Poplar Creek. Floodplain soils from Lower EFPC
served as backfill material for construction of the Sewer Line Beltway through the city of Oak
Ridge. These soils have been included as part of the investigation. The site includes portions
of ORR and commercial, residential, agricultural, and miscellaneous areas within the city of Oak
Ridge. Some residences are within 400 m (0.25 miles) of the areas to be remediated.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
Between 1953 and 1983, operation of the lithium isotope separation processes at the Y-12
Plant resulted in the release of 108,000-212,000 kg (239,000-470,000 Ib) of mercury into Lower
EFPC. Although the primary mercury loss from the Y-12 Plant stopped in 1963, mercury
continues to be released into Lower EFPC from secondary sources (e.g., building drain systems,
sewers, and connecting lines) at the plant. The current release averages approximately 20 g/day
(0.7 oz/day), down from 100 g/day (3.5 oz/day) in 1985. Portions of the sewers were relined in
1986-1987 to reduce mercury losses. Efforts continue to further reduce mercury losses (e.g.,
decontamination and decommissioning, reduction of mercury in plant effluents, and remediation
of mercury-use areas). The goal of these efforts is to meet the requirements of the draft National
Pollutant Discharge Elimination System permit.
The state of Tennessee posted advisory signs in 1983 warning the public that Lower
EFPC was contaminated. In 1989, ORR was placed on the National Priorities List (NPL) as a
CERCLA site requiring investigation. Areas of the EFPC OU contaminated by DOE releases
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U)
APPROXIMATE
WATERSHED
BOUNDARY
UPPEH EAST FORK POPLAR CREEK
2 MILES
I
3 KM
I
LEGEND
| | EPPC floodplain
\OM Sewer Line Beltway
020.11603-107
Fig. 2.1. Location map for Lower EFPC.
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of hazardous substances are also considered part of the NPL site. With respect to EFPC soils,
the release (or site) is limited to areas within the 100-year floodplain and does not extend to areas
outside the floodplain, with the exception of soils that may have been taken from the floodplain
and used in other areas as fill (e.g., Sewer Line Beltway). (A more detailed description of the
release is provided in the remedial investigation/feasibility study.)
In accordance with CERCLA and as agreed to in the FFA (DOE 1992) by DOE, EPA,
and TDEC, a remedial investigation (DOE 1994a) and a feasibility study (DOE 1994b) were
conducted, and a proposed plan (DOE 1995b) was developed. This ROD fulfills the next
requirement of the CERCLA process. It presents the selected remedial action for Lower EFPC,
chosen in accordance with CERCLA, as amended by SARA and, to the extent practicable, the
National Oil and Hazardous Substance Contingency Plan. The decision for this site is based on
the information contained in the administrative record file.
HIGHLIGHTS OF COMMUNITY PARTICIPATION
Public involvement has been an important element throughout the Lower EFPC project.
In the early stages of the project, DOE conducted numerous meetings with property owners who
lived along the creek: to inform them of sampling and other activities associated with the remedial
investigation.
At a public meeting held by DOE in March 1993, the remedial investigation and
preliminary feasibility study were presented. DOE answered questions and comments from the
public at that point. One outcome of the meeting was the formation of a citizens working group
of about 30 members of the public to provide feedback to DOE and its contractors during
preparation and selection of potential remedial action alternatives. From the outset, DOE
explained that the group was not a decision-making or consensus-building group. DOE is
responsible for recommending the preferred cleanup alternative to EPA and TDEC.
Between May 1993 and November 1994, 12 meetings were held with the citizens group
to provide information to better understand the cleanup process. Meeting discussions focused on
issues involved in conducting the remedial investigation and the feasibility study, building blocks
of the site-wide cleanup alternatives, institutional actions; ideal characteristics of a remedial
action, the risk assessment process, mercury-reduction efforts at the Y-12 Plant, and mercury
speciation. The group also toured areas of the creek that contained the highest levels of mercury.
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Members of the citizens working group played an active role throughout the entire
decision-making process and especially during the official public involvement period. They
submitted articles to the local newspapers, sent comments to DOE, and encouraged other
members of the community to become involved.
DOE believes input from the citizens group has been invaluable to the project team in
understanding community concerns and opinions on the project.
In addition to the citizens group, DOE provided fact sheets and updated them on a
regular basis, published numerous articles in a widely distributed newsletter, issued media
releases, contacted local media about meetings dealing with Lower EFPC issues, and produced
a video that helped citizens understand more about potential cleanup alternatives for the floodplain
soils.
In the summer of 1994, the Lower EFPC team participated in DOE's Speakers Bureau
to generate awareness of the project among community and civic organizations. As a result, the
team spoke to eight organizations where approximately 260 people learned more about the
project.
The public also had the opportunity to receive all the documents leading up to DOE's
selection of the preferred alternative [the remedial investigation (DOE 1994a), the feasibility
study (DOE 1994b), and the proposed plan (DOE 1995b)]. A document request form was sent
to more than 1,500 stakeholders. More than 100 people requested and received documents.
DOE placed numerous announcements in area newspapers and on local television and
radio to prepare for the official public comment period. The public comment period was
January 9, 1995, through February 22, 1995. DOE formally presented the preferred alternative
at the official public meeting January 26, 1995. Approximately 50 comments were received
during the meeting, 9 of which were submitted anonymously. DOE received approximately 40
letters during the public comment period. Responses to the summarized comments received are
included in this ROD as Part 3, Responsiveness Summary.
DOE held an informal public meeting June 8, 1995, and accepted additional written
comments between June 14, 1995, and July 13, 1995. During that public comment period, DOE
received six letters specifically related to the 400 ppm cleanup level. Responses to those letters
are also summarized in the Responsiveness Summary.
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SCOPE AND ROLE OF OU
The Lower EFPC OU encompasses soil, sediment, and groundwater contaminated with
mercury downstream from Lake Reality at the Y-12 Plant to the confluence of Poplar Creek.
Because topographic ridges separate the site from the other DOE ORR plants, only waterborne
contaminants carried by EFPC from the Y-12 Plant affect the site. The remedial action for the
Lower EFPC site fits into the overall cleanup strategy for ORR by addressing this downstream
contamination. The surface water remediation is not within the scope of this project, but is
discussed for informational purposes only. Investigations of Upper EFPC and other OUs address
contamination within and adjacent to the Y-12 Plant and on the rest of ORR.
SUMMARY OF SITE CHARACTERISTICS
The Lower EFPC site includes two distinct but overlapping areas—Lower EFPC and the
Sewer Line Beltway. Lower EFPC flows 23.3 km (14.5 miles) from Lake Reality at the Y-12
Plant to its confluence with Poplar Creek near the Oak Ridge K-25 Site (see Fig. 2.1). The site
includes creek sediment and soils making up the creek's 100-year floodplain. The Sewer Line
Beltway consists of 16 km (10 miles) of sewer lines. One portion is within the floodplain of
Lower EFPC and two branches are in the city of Oak Ridge. Because the CERCLA risk
assessment process and the RI report confirmed Sewer Line Beltway soils present no significant
risk, the beltway is not discussed further.
Lower EFPC is a perennial stream flowing through Anderson and Roane Counties in
Oak Ridge, Tennessee. The creek's watershed [approximately 77.2 km2 (29.8 mile2)] consists
of many streams and tributaries that flow into EFPC. This watershed lies primarily within East
Fork Valley and is bounded by Black Oak Ridge on the northwest and East Fork Ridge on the
southeast.
A range of soils makes up the 270-ha (670-acre) floodplain of Lower EFPC and is
mostly well-drained and somewhat acidic. Although floodplain soils are classified as prime
farmland, much of the land in the floodplain is already in or committed to urban development
or attenuating flood flow during storms, which thereby exempts this classification.
Surface water flow leaving the Y-12 Plant contains spring water, surface drainage water,
and a relatively large amount of Y-12 Plant discharge water. This flow averages 0,24 mVsecond
(8.6 ftVsecond) and is augmented downstream by additional groundwater discharge, stormwater
JT9S0328.2DH/SDD • July 28. 1995
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and stormflow, and the discharge of the Oak Ridge Sewage Treatment Plant. Some contaminants
are present in surface water during baseflow conditions. Stormflow exhibits higher
concentrations of various metals, indicating they are particle-bound.
Results from the first phase of the soil, sediment, groundwater, and surface water
sampling in the remedial investigation showed detectable levels of 13 heavy metals, 9 polycyclic
aromatic hydrocarbons (PAHs), 2 polychlorinated biphenyls (PCBs), and 11 radionuclides.
For the heavy metals, mercury was by far the most significant contributor with > 85
percent of the total noncarcinogenic risk. For radionuclides, total uranium accounted for 98
percent of the total activity. Risk associated with exposure to radionuclides fell within the EPA
acceptable target range in all cases. The organic compound groups of PAHs and PCBs did not
substantially contribute to the estimated risks to human health. The results of the baseline human
health risk assessment confirmed mercury as the predominant contaminant of concern in Lower
EFPC.
Groundwater flow in the floodplain is predominantly through a fairly shallow stormflow
zone immediately beneath the land surface. Enhanced hydraulic conductivity in this zone results
from a widespread system of small cavities caused by roots, worms, and burrowing animals. In
addition, the shallow or alluvial aquifer (composed of stream sediments) reaches 6 m (20 ft) in
thickness. Water levels fluctuate in the alluvial aquifer, reflecting evapotranspiration and the
aquifer's hydraulic communication with Lower EFPC. East Fork Valley is predominantly
developed in limestone bedrock. Some evidence for relatively deep along-strike groundwater
flow exists; however, bedrock is unlikely to provide much water to the creek. Even if the creek
loses water to the bedrock aquifer, mercury contamination is predominantly particle-bound, and
the low-velocity flow in the bedrock would not transport these particles. In addition to mercury,
groundwater samples showed elevated naturally occurring metals, primarily particle-bound and
not available for transport through the aquifer. No active potable water wells are located within
the floodplain, and groundwater is currently not a drinking water source.
Ecological resources potentially impacted by remedial activities include aquatic and
terrestrial habitats, animals, and plants. Surface water and sediments are two primary abiotic
components of aquatic habitats and are the major exposure pathways for contaminants. These
habitats occupy about 21 ha (52 acres). Riparian habitats (habitats near a stream) include the
stream channel, banks, and floodplain that span the transition from aquatic to terrestrial habitats
and communities. Many organisms in the creek use both communities in the course of their
lives. For example, many insects have aquatic larval stages, but terrestrial adult stages. Riparian
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habitats are fairly narrow along the creek, ranging from 10 to 30 m (11 to 33 yd) wide.
Disturbance of riparian habitats often has direct negative effects on the wide range of biota that
use this habitat.
An analysis of species richness or diversity in aquatic biota can serve as an indicator of
water quality. A 1991 fish population survey in Lower EFPC, using Hinds Creek as a control,
found taxonomic richness and diversity were depressed near the Y-12 Plant, but increased further
downstream, probably as a result of the reduction in toxicant concentrations downstream. Species
tolerant of contamination predominated near the Y-12 Plant, supporting this conclusion. In
general, many taxa exhibited decreased diversity all along Lower EFPC as compared to the
control site.
Exposure of terrestrial plants and animals to contaminants in soil and attendant vegetation
varies according to feeding habits. For the evaluation of ecological risk, three terrestrial cover
types were defined: urban, forest, and field. These were further divided into more specific
subelements. In terms of these subelements, the majority of terrestrial habitats are bottomland
hardwoods. The only significant and systematic variation in terrestrial biota was an increase in
the mean number of flying insect populations downstream. There was also an increase in the
mean number of aquatic insect larvae downstream. In general, biological diversity increased with
distance from the Y-12 Plant.
The U.S. Army Corps of Engineers defines wetlands as swamps, marshes, bogs, and
similar areas having wetland hydrology, hydrophytic vegetation, and hydric soils. A floodplain
and wetlands assessment [Appendix J of the feasibility study (DOE 1994b)] and floodplain
statement of findings [Appendix K of the feasibility study (DOE 1994b)] were prepared for
Lower EFPC. Seventeen jurisdictional wetland areas were identified, comprising approximately
4.9 ha (12 acres). Most of these wetlands provide highly productive wildlife habitat: Studies
undertaken in conjunction with the investigation of the Lower EFPC show that mercury is being
accumulated by wetland animals at concentrations comparable to levels found in other animals
in other nonwetland areas of the floodplain and that some of this mercury occurs as
methylmercury in crayfish. Only 0.24 ha (0.6 acres) of one jurisdictional wetland area will be
affected by implementation of the selected remedy.
Although potential habitat may be available along the Lower EFPC floodplain, there is
no documentation of the presence of any federally listed or state-listed threatened or endangered
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species. The remedial investigation (DOE 1994a) and the feasibility study (DOE 1994b) list the
threatened and endangered species that have been reported in Oak Ridge and the surrounding
area.
An archaeological reconnaissance of the Lower EFPC area identified six historic period
sites, two prehistoric sites, and a steel truss bridge. The identified archaeological sites will not
be affected by remediation of the floodplain soils.
The area that Lower EFPC flows through hosts a range of human activities and land
uses. For the purposes of the site investigation, these uses were grouped into five categories:
residential, commercial, agricultural, other, and DOE-owned. Households within 150 m (500
ft) of the creek with an associated population of 1,189 are potentially most affected by the
contamination. These residents live in clusters near the intersection of Oak Ridge Turnpike and
Illinois Avenue, and also in west Oak Ridge near Bruner's Center. These areas are shown in the
"Selected Remedy" section.
Contamination of the Lower EFPC can be understood through a conceptual model for
contaminant transport. The initial premise is that soil contamination in the floodplain is closely
linked to hydrologic events. Contaminants from the Y-12 Plant were washed down Lower EFPC
during high-flow conditions following rain storms. At least some contaminants were adsorbed
onto sediment particles and were transported downstream in a suspended phase. Other
contaminants were transported in dissolved phase. During flood events, the creek overflows its
banks and spreads out across its floodplain, depositing contaminated sediments on vegetation and
the land. Considering this model, the remedial investigation focused oh the evaluation of surface
water, creek sediments, floodplain soils, and groundwater as potentially affected media. The
remedial investigation identified a wide range of contaminants of potential concern (DOE 1994a).
Mercury concentrations in Lower EFPC decrease with distance downstream from the
Y-12 Plant, although above-background concentrations occur at depositional areas (i.e., where
the water flow slows down, such as through braided areas) throughout the floodplain. In general,
however, mercury and other inorganic constituents are situated in defined areas of the floodplain
and not randomly scattered throughout its length.
Creek sediments contain the same constituents as floodplain soils, but at lower
concentrations. Because of the transient nature of sediments, the distribution of metals is not as
predictable in sediments as it is in soils. The upper reaches generally show somewhat elevated
levels of the various metals compared to the lower sections of the creek.
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SUMMARY OF SITE RISKS
Baseline human health and ecological risk assessments were conducted as part of the
remedial investigation (DOE 1994a) to examine the potential for adverse health effects in humans
and ecological receptors from exposure to chemicals released from the Y-12 Plant to Lower
EFPC. The results of the baseline risk assessment were used to determine the need for
remediation. The baseline risk assessment was, therefore, an evaluation of potential risks in the
absence of remedial action.
HUMAN HEALTH KISKS
The baseline human health risk assessment used a "tiered" or phased approach. In Tier
I, contaminant data from locations of highest projected concentration were screened against
toxicity data to identify chemicals of potential concern. The second phase (Tier II) was the full
baseline evaluation using a comprehensive data set and a thorough assessment of current and
future land uses. Tier III was a probabilistic risk assessment. In this approach, called Monte
Carlo simulation, input parameters are defined as ranges or distributions. The result of this
simulation is a distribution of risk estimates from which the probability of individual values can
be determined. This is used to help understand and quantify the uncertainty inherent in the
results of the baseline risk assessment.
The EFPC floodplain was divided along the length of the creek into nine segments for
the purposes of data aggregation and risk assessment. These segments were based on an
understanding of the nature and extent of contamination and a knowledge of current and projected
future land uses. Inorganic and organic chemicals and radionuclides were identified as chemicals
of potential concern based on the concentration-toxicity screen (Tier I) evaluation. These
substances were carried through the full baseline human health risk assessment (Tier II).
Sampling data from EFPC were aggregated so that exposure point concentrations could be
calculated separately for each land-use area within each segment.
The exposure scenarios were based on land-use type: (1) agricultural setting,
(2) residential populations, (3) commercial setting, and (4) occasional use of open land. The
receptor groups at greatest risk of exposure were assumed to be children and adults who reside
in the vicinity of EFPC. For each exposure scenario and receptor group, the intensity, duration,
and frequency of exposure were characterized. Exposure pathways include the following:
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• incidental ingestion of soil;
• dermal exposure to soil;
• dermal exposure to surface water while swimming and wading;
• incidental ingestion of surface water while swimming;
• dermal exposure to sediments while wading;
• ingestion of groundwater as a drinking water source and inhalation of
groundwater vapors during showering;
• ingestion of homegrown produce, beef, and dairy;
• ingestion of recreationally caught fish; and
• inhalation of particulates while mowing.
The exposure evaluations were based on reasonable maximum exposure assumptions as
requested by EPA Region IV. The reasonable maximum exposure estimate is a "high end"
conservative estimate of exposure in the population at potential risk. In addition to reasonable
maximum exposure point estimates, probability simulations were used to generate a range of
exposure and risk estimates (Tier III) that were used in uncertainty analysis and as a supplement
to the single-point reasonable maximum exposure estimate.
Noncarcinogenic and carcinogenic effects of exposure to contaminants in EFPC were
evaluated in the risk assessment. Toxicity measures needed to evaluate these effects were selected
for chemical compounds and radionuclides and include: (1) reference doses for oral exposure —
acceptable intake values for chronic and subchronic exposure (noncarcinogenic effects),
(2) reference concentrations for inhalation exposure—acceptable intake values for subchronic and
chronic exposure (noncarcinogenic effects), (3) cancer slope factors for oral exposure, and (4)
cancer slope factors for the inhalation route.
EPA had withdrawn the oral reference dose for mercury from the Integrated Risk
Information System data base (EPA 1993). A reference dose (0.0003 mg/kg/day) obtained from
the EPA Health Effects Assessment Summary Tables for Fiscal Year 1993-94 (EPA 1992a) was
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used in the baseline human health risk assessment. This reference dose was based on toxicity
testing using soluble mercury species (mercuric chloride) in laboratory animals, not the less
soluble forms (mercuric sulfide and elemental mercury) that were shown to predominate in EFPC
floodplain soils. The baseline risk assessment, therefore, conservatively assumed that all mercury
in EFPC is present in its most toxic and bioavailable form.
Risk characterization was conducted using reasonable maximum exposure assumptions.
This approach resulted in high end (i.e., protective) estimates of the potential for adverse
noncarcinogenic and carcinogenic effects associated with long-term exposure to contaminants in.
EFPC. For noncarcinogenic effects, risk estimates were determined to be of concern (i.e.,
exceeding the target range established by EPA) if the hazard quotient for any given chemical or
the hazard index for combined exposure across chemicals exceeds 1. Estimates of excess lifetime
cancer risk that exceed 1 x 10"* were determined to be of concern (i.e., fall outside the target
range of 1 x 10"6 to 1 x KT* established by EPA for waste site remediation under the CERCLA
program).
Groundwater does not present ah unacceptable risk to human health and the environment.
In the RI, risk estimates for the groundwater ingestion pathway were based on data from the soil
horizon [0-6.3 m (0-20 ft deep)] and exceeded the acceptable EPA target range. These risk
estimates considered all conceivable uses of the groundwater regardless of probability, including
residential use. Residential use of groundwater from the soil horizon, however, is unrealistic
because of insufficient .yield, the availability of municipal water supply, and legal restriction on
drilling water supply wells less than 6.3 m (20 ft) in depth [TDEC 1200-4-9-.10(3)(a)]. (The
only calculated risk greater than EPA's protective range associated with other groundwater
horizons was related to manganese levels, which are naturally occurring and not the result of a
release). Accordingly, groundwater is not considered to present an unacceptable risk and
remediation goal options for groundwater were not carried over into the analysis of alternatives
in the FS or this ROD.
Results of the baseline human health risk assessment indicate unacceptable risks to human
health (i.e., exceed the target ranges established by EPA under the CERCLA program for waste
site remediation) may result from exposure to the Lower EFPC floodplain soils. Two exposure
pathways of concern were identified: (1) inadvertent ingestion of soils and (2) ingestion of
groundwater as a drinking water source.
Risk estimates based on reasonable maximum exposure assumptions indicate the potential
for adverse health effects associated with long-term exposure to EFPC soils. Children ages 3 to
J7950328.2DH/SDD • July 21. 1995
2-12
-------
12 years were identified as the receptor group at greatest risk. Mercury was identified as the
predominant contaminant of concern and inadvertent soil ingestion to be the exposure pathway
of greatest significance. Remaining toxicity due to other contaminants present will be reduced
by the remedial action. Organic chemicals observed in EFPC media did not substantially
contribute to the estimated risks to human health. Risks associated with exposure to radionuclides
fell within the EPA acceptable target range in all cases.
The results of the baseline human health risk assessment confirmed mercury as the
contaminant of concern in EFPC and direct exposure to soils as the critical exposure pathway.
Remediation goals were derived for mercury in EFPC soils.
Evaluation of risk presented in the feasibility study focused on mercury as the single
contaminant of concern in floodplain soils and direct soil contact as the exposure pathway of
concern (DOE 1994b). The remediation goal was developed to protect the most sensitive
receptors (i.e., children) following long-term, inadvertent ingestion exposure and dermal contact
with soils containing mercury.
Results of mercury speciation and leaching/availability studies (DOE 1994c) on EFPC
soils indicated that the less mobile and less bioavailable forms of mercury predominate in EFPC
floodplain soils. The remediation goal is based on the presence of mercuric sulfide and metallic
mercury rather than mercuric chloride (i.e., the mercury species upon which the mercury
reference dose was based). The remediation goal was derived as a conservative, risk-based value
(point estimate), following EPA methods. In addition to the point estimate, a quantitative
uncertainty analysis was conducted to examine the uncertainty surrounding the remediation goal
and the assumptions that form the basis of this estimate.
ECOLOGICAL RISKS
The ecological risk assessment followed EPA's Framework far Ecological Risk
Assessment (EPA 1992b), which includes problem formulation, analysis (exposure
characterization and effects characterization), and risk characterization. Assessment and
measurement endpoints were defined and used in the assessment. Approved protocols were
followed to select and measure abundance, diversity, taxonomic richness, and contaminant body
burdens at various trophic levels in aquatic organisms (fish and benthic macroinvertebrates) and
terrestrial organisms (small mammals, birds, earthworms, insects, and vegetation). Organisms
were analyzed to determine the whole-body concentrations of inorganic chemicals, PAHs,
pesticides, and PCBs.
rTO(028.2DH/SDD July 2g ,995
2-13
-------
Surface water, sediment, and floodplain soils were evaluated as potential sources of
contaminant risk to nonhuman receptors. Inorganics, PCBs, and chlordane as a representative
of pesticides, and PAHs were retained as contaminants of potential concern for plants and
animals.
Consumption of contaminated organisms provides risk to both aquatic and terrestrial
predators. Historical and current studies of bioaccumulation showed (1) higher body burdens of
contaminants in common stonerollers, redbreast sunfish, crayfish, earthworms, and terrestrial
insects at EFPC sites than at uncontaminated reference sites; and (2) generally decreasing body
burdens with increasing distance downstream from the Y-12 Plant. A. notable exception is that
redbreast sunfish had higher PCB and pesticide body burdens at some sites distant from the Y-12
Plant than at the site closest to the Y-12 Plant. Based on tree ring analysis, the trunks of trees
showed elevated mercury levels that probably reflect exposures three to four decades ago.
Elevated contaminant body burdens were also noted in terrestrial mid-level predators (shrews and
wrens), reflecting current exposures. Generally, elevated contaminant levels were not observed
in white-footed mice which consume plants and terrestrial insects, or in plant leaves.
No threatened or endangered species nor critical habitats for them were found in the-
EFPC. floodplain. Therefore, the remedial investigation concluded that there is no current threat
from contaminants in the EFPC floodplain to threatened or endangered species or their critical
habitats (DOE 1994a).
The remedial investigation (DOE 1994a) concluded that there is ongoing risk to
ecological resources, especially aquatic organisms in the upper part of the creek, from exposure
to contaminants in environmental media and food. Mercury was the primary contaminant of
concern in the sediments and floodplain soils. PCBs were a contaminant of concern associated
with biota. The source of the PCBs appears to be associated with the Upper EFPC OU and will
be evaluated as part of the Y-12 Plant Environmental Restoration Program. Direct contact with
and ingestion of surface water, sediment, and sediment pore water are primary exposure pathways
for aquatic organisms. The food chain is also a primary exposure pathway for aquatic fauna.
Releases from the Y-12 Plant are the primary source of waterborne contaminants; however,
evidence suggests that some ecological recovery of the aquatic community has been occurring in
the upper reaches of the creek, as documented by the Y-12 Plant Biological Monitoring and
Abatement Program (Loar et al. 1992; Hinzman et al. 1993). Nevertheless, elevated contaminant
body burdens and an excess of pollution-tolerant species are still present.
JT95032S.2DH/SDD ju]y 28. 1995
2-14
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Toxicity studies (DOE 1994c) showed no toxicity to test organisms from chemicals
extracted when sediment was suspended in water. Sediment-based food chain exposures were
also evaluated (DOE 1995). Exposures from EFPC sediments are substantially lower than those
from surface water. EFPC sediments do not currently pose a risk to aquatic organisms nor their
predators.
The food chain is the most important exposure pathway for terrestrial organisms. Initial
results in the remedial investigation report (DOE 1994a) indicated that there were potential risks
to terrestrial organisms. Additional studies were done to determine the relationship of apparent
risks to soil mercury concentrations (DOE 1994c). These studies included analysis of organisms
exposed in wetlands and expanded analysis of mercury content in vegetation. The studies
concluded that there is no threat to plant communities from mercury in floodplain soils. Mercury
concentrations in some floodplain soils are a potential threat to biota by exposure through the
food chain.
Ecologically based remediation goals were derived by evaluating several exposure
scenarios. Site-specific data, exposure assumptions, and toxicity thresholds were evaluated
further to determine what soil concentrations could protect biota.
DESCRIPTION OF ALTERNATIVES
Remedial alternatives evaluated in the feasibility study (DOE 1994b) spanned a wide
range of cleanup options for Lower EFPC. Table 2.1 summarizes the impacts of each of the
alternatives. In all cases, best management practices would be followed to control fugitive dust,
surface water and rain runon and runoff, erosion, and to minimize the area disturbed. Alternative
3 is the selected remedy and is discussed in more detail in the "Selected Remedy" section.
ALTERNATIVE 1: NO ACTION
CERCLA requires that the no action alternative be evaluated at every site to establish
a baseline for comparison. Under this alternative, no further action would be taken at the site
to prevent exposure to the contaminants. No time would be required to implement the no action
alternative. Monitoring would be undertaken for 30 years because risk would not be reduced to
acceptable levels.
JT950328.2DH/SDD ju!y 28. 1995
2-15
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Table 2.1. Summary of impacts due to Lower EFPC remedial alternatives
Import
1993 Cost ($ million) ,
Volume excavated (m!)
Area impacted (hectare)
Wetlands area impacted (hectare)
Time to complete (weeks)
Dump truck loads
Area fenced (hectare)
Area capped (hectare)
Transportation injuries to worker*
Transportation fatalities to worker*
Transportation injuries to the community
Transportation fatalities to the community1*
Construction injuries to worker
Construction-fatalities to worker1
Total injuries
Total fatalities
Alternative
1
12
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
23-50
7,103
2.47
0.25
62
929 .
0
0.13
0.0018
0.0009
0.050
0.0033
5.27
0.039
5.32
0.044
' 3
22-28
7,646
2.47
0.25
26
1.000
0
- 0 '
0.0018
0.0010
0.052
0.0034
5.15
0.038
5.20
0.043
4
26-57
7,103
2.47
0.25
62
929
0
jp.13
0.0018
0.0009
0.050
0.0033
3.85
0.029
3.90
0.033
f
26-55
7,646
2.47
0.25
61
1.000
0
0
0.0018
0.0010
0.052
0.0034
4.10
0.031
4.16
0.035
6
22-47
0
2.79
0.25
78
0
2.23
1.51
0.0010
0.0005
0.028
0.0018
3:12
0.023
3.15
0.026
7
18-39
2,329
1.85
0.25
84
697
1.12
0
0.0013
0.0007
0.036
0.0024
3.12
0.023
3.15
0.026
•Numbers < 1 indicate that injury is unlikely to occur over the remedial action activity period.
'Numbers < 1 indicate that a fatality is unlikely to occur over the remedial action activity period.
Alt. 1: No Action
All. 2: Containment and Institutional Actions for Commercial/DOE and Other
Remedial Unit Soils; Excavation and Disposal of Residential Remedial Unit
Soils
All. 3: Excavation and Disposal of Commercial/DOE, Other, and Residential
Remedial Units Soils
Alt. 4: Containment and Institutional Actions for Commercial/DOE and Other
Remedial Units Soils: Excavation, Treatment, and Beneficial Reuse of
Residential Remedial Unit Soils
Alt. 5: Excavation. Treatment, and Beneficial Reuse of Commercial/DOE, Other.
and Residential Remedial Units Soils
Alt. 6: Containment and Institutional Actions for Commercial/DOE, Other, and
DOE-Acquired (Previously Residential) Remedial Units Soils
Alt. 7: Institutional Actions for Commercial/DOE and Other Remedial Units Soils;
Excavation and Disposal of Residential Remedial Unit Soils
EFPC = East Fork Poplar Creek
m = meter
$ = dollar
-------
ALTERNATIVE 2: CONTAINMENT AND INSTITUTIONAL ACTIONS FOR
COMMERCIAL/DOE AND OTHER REMEDIAL UNIT SOILS; EXCAVATION AND
DISPOSAL OF RESIDENTIAL REMEDIAL UNIT SOILS
Under this alternative, all soil with mercury concentrations greater than the remediation
goal in the Commercial/DOE and Other Remedial Units would be contained by a 45-cm (18-in.)
soil cover with a subsoil animal intrusion barrier (netting). First, vegetation would be removed,
and the stream bank stabilized. Netting would be installed, the soil placed over the contaminated
area, and grass planted. Long-term maintenance and periodic environmental monitoring,
including a CERCLA-required 5-year recurring review, would be performed. Institutional actions
for the Commercial/DOE and Other Remedial Units would include future land-use limitations,
construction permit restrictions, public education, and signs.
Soils with mercury concentrations greater than the remediation goal in the Residential
Remedial Unit would be excavated and disposed of in a permitted landfill at the Y-12 Plant. A
small area of one of the wetland areas would be remediated and restored. Clean borrow soil
would be used to fill the excavation. Implementation of this alternative may involve building
additional roads, removing vegetation and soils, grading excavated areas, and controlling surface
runoff.
ALTERNATIVE 3: EXCAVATION AND DISPOSAL OF COMMERCIAL/DOE, OTHER,
AND RESIDENTIAL REMEDIAL UNITS SOILS
Floodplain soils with mercury concentrations greater than the remediation goal would
be excavated and disposed of in a permitted landfill at the Y-12 Plant. A small area of wetland
would be remediated and restored. Clean borrow soil would be used to fill the excavation.
Implementation of this alternative may involve building additional roads, removing vegetation and
soils, grading excavated areas, and controlling surface runoff.
ALTERNATIVE 4: CONTAINMENT AND INSTITUTIONAL ACTIONS FOR
COMMERCIAL/DOE AND OTHER REMEDIAL UNITS SOILS; EXCAVATION,
TREATMENT, AND BENEFICIAL REUSE OF RESIDENTIAL REMEDIAL UNIT SOILS
This alternative would cover Commercial/DOE and Other Remedial Units with mercury
concentrations greater than the remediation goal with 45 cm (18 in.) of uncontaminated soil and
netting. Also, institutional actions as described for Alternative 2 would be implemented. All
vegetation would be removed, and the stream bank stabilized.
JT950328.2DH/SDD July 28. 1995
2-17
-------
Residential Remedial Unit soils with mercury concentrations greater than the remediation
goal would be excavated and treated on site in a low-temperature thermal desorption unit.
Treated soils would be enhanced with organic matter, nutrients, and water and used as fill in the
excavated areas within the Lower EFPC floodplain. A small wetlands area would be remediated
and restored.
Implementation of this alternative would involve treatment, which, through the process
of waste concentration, may produce a Resource Conservation and Recovery Act-characteristic
waste, a low-level radioactive waste, and/or air emissions. Also, as with Alternative 2, additional
roads may be constructed, vegetation and soils removed, excavated areas graded, and surface
runoff controls installed. The treatment process residuals, or secondary waste streams, would
be packaged for shipment to an approved or licensed off-site disposal facility as necessary. Air
emissions would be analyzed for hazardous pollutants. Consultation with TDEC and EPA would
be required to comply substantively with the requirements of any permitting processes.
ALTERNATIVE 5: EXCAVATION, TREATMENT, AND BENEFICIAL REUSE OF
COMMERCIAL/DOE, OTHER, AND RESIDENTIAL REMEDIAL UNITS SOILS
For this alternative, floodplain soils with mercury concentrations greater than the
remediation goal would be excavated and treated on site in a low-temperature thermal desorption
unit. Treated soil would be enhanced and returned to the excavation, and a small wetlands area
would be remediated and restored. This alternative would also involve treatment, which, through
the process of waste concentration, may produce Resource Conservation and Recovery Act-
characteristic waste, low-level radioactive waste, and/or air emissions.
ALTERNATIVE 6: CONTAINMENT AND INSTITUTIONAL ACTIONS FOR
COMMERCIAL/DOE, OTHER, AND DOE-ACQUIRED (PREVIOUSLY RESIDENTIAL)
REMEDIAL UNITS SOILS
For Alternative 6, DOE would acquire the real estate right to fence and contain the
NOAA site. One area would be contained by a 45-cm (18-in.) soil cover and netting as described
in Alternative 2. DOE would also acquire, fence, and contain the remaining property in the
Residential Remedial Unit containing soils with mercury concentrations above the remediation
goaL The remaining floodplain soils with mercury concentrations above the remediation goal
would be contained by a 45-cm (18-in.) soil cover and netting but not fenced. The DOE real
estate acquisition could include easement, right-of-way, and property procurement. Long-term
maintenance and periodic environmental monitoring, including a 5-year recurring review, would
JT950328.2DH/SDD , July 28. I99S
2-18
-------
ensure that levels of risk remain acceptable. Institutional actions would include future land-use
limitations, construction permit restrictions, public education, and signs.
ALTERNATIVE 7: INSTITUTIONAL ACTIONS FOR COMMERCIAL/DOE AND
OTHER REMEDIAL UNITS SOILS; EXCAVATION AND DISPOSAL OF RESIDENTIAL
REMEDIAL UNIT SOILS
Alternative 7 addresses remedial actions on an area-specific basis. For this alternative,
DOE would acquire the real estate rights to and fence the NOAA site. Soil containing mercury
above the remediation goal would remain uncovered inside the fenced area. Institutional actions,
including land-use restrictions, would be implemented.
In the Residential Remedial Unit, all remaining soil with mercury concentrations greater
than the remediation goal would be excavated and disposed of in a permitted landfill at the Y-12
Plant. Clean borrow soil would be used to fill the excavation.
In the remaining areas of the Commercial/DOE and Other Remedial Units, institutional
actions would be implemented to maintain nonagricultural and nonresidential land use.
Institutional action in these areas and in the fenced areas would include future land-use
limitations, construction permit restrictions, public education, signs, environmental monitoring,
and a 5-year recurring review. Implementation of this alternative would involve activities very
similar to those described for Alternatives 3 and 6.
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
DOE, TDEC, and EPA evaluated all alternatives against the nine criteria provided by
•CERCLA for final remedial actions. This comparative analysis is provided here.
OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
Overall protection of human health and the environment addresses whether an alternative
provides adequate long- and short-term protection of human health and the environment from
unacceptable risks from hazardous substances by reducing, eliminating, or controlling exposure
and describes how risks posed through each pathway are eliminated, reduced, or controlled
through treatment, engineering controls, or institutional controls. All of the alternatives, with
JT950328.2DH/SDD July 28. 1995
2-19
-------
the exception of the no action alternative, adequately protect human health and the environment
by eliminating, reducing, or controlling risk through treatment, engineering controls, or
institutional actions.
The greatest risk associated with Alternatives 2 through 7 would be to ecological
receptors. Alternatives 3 and 5 would eliminate unacceptable residual risk in the floodplain and
would not permanently alter floodplain habitat. These alternatives would impact ecological
receptors in small areas and recovery might be slow. Alternative 7 would provide a high degree
of overall protection to human health but would leave residual risk for ecological receptors.
Alternatives 2 and 4 would permanently alter habitat and land use, and residual contaminants
would remain. Alternative 6 provides the least, overall protection of the action alternatives
because containment and extensive fencing throughout the floodplain would permanently alter
habitat, and long-term maintenance of fencing and access controls is considered difficult.
The no action alternative is not considered further in this analysis because it does not
protect human health and the environment.
COMPLIANCE WITH APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENTS
Compliance with applicable or relevant and appropriate requirements (ARARs) addresses
whether a remedy will meet all ARARs of all federal and state environmental statutes and/or
provide grounds for invoking a waiver. Alternatives 2 through 7 would comply with identified
federal and state ARARs. No waivers would be necessary to implement any of the remedial
alternatives. 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 3 and 5 provide the greatest degree
i
of long-term effectiveness and permanence because they would remove all contaminated material
above levels of concern from the OU. Alternatives 2 and 4 provide slightly less long-term
effectiveness and permanence because some of the contaminated material would remain in the
floodplain and be covered by 45 cm (18 in.) of soil. Alternative 7 provides less long-term
effectiveness and permanence than Alternatives 2 and 4 because only institutional actions limit
contact with the contaminated material in the floodplain. Maintenance of fencing and land-use
JT950328.2DH/SDD July 28. 1995
2-20
-------
restrictions would be required for long-term effectiveness in some areas. Alternative 6 provides
the least amount of long-term effectiveness and permanence because all contaminated material
would remain in place, and access would be restricted by fencing.
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. Alternatives 4 and 5 would reduce the toxicity of mercury-contaminated soil through
low-temperature thermal desorption. None of the other alternatives include treatment processes.
SHORT-TERM EFFECTIVENESS AND ENVIRONMENTAL IMPACTS
Short-term effectiveness considers impact to community, site workers, and the
environment during construction and implementation and includes the time until protection is
achieved. All of the alternatives involve minimal transportation and construction accident risks.
Risk to the community and to workers from exposure to contaminants would be within acceptable
limits because engineering controls and a project-specific health and safety plan, including
personal protective equipment, would be used. A floodplain statement of findings, provided as
an appendix to the feasibility study (DOE 1994b), is the resultant document from the floodplain
assessment of Lower EFPC. The statement of findings concludes that there is no practicable
alternative to remediating the Lower EFPC floodplain soil that would not destroy any wetland
areas. Excavation involves disturbance of approximately 0.24 ha (0.6 acres) of wetlands. The
wetlands in the Lower EFPC floodplain serve as wildlife habitat, but also have low flood flow
attenuation and sediment retention functions. Any disturbed wetlands would be remediated and
restored.
Alternative 7 would have the least impact on the environment because only a small area
of floodplain habitat would be destroyed. Alternatives 2, 3, and 6 would have a greater adverse
effect on the environment than Alternative 7 because they involve excavation of a larger area of
contaminated floodplain soil. Alternatives 4 and 5 would have the largest impact on the
environment because implementation would destroy the largest area of habitat of the alternatives,
and treatment would involve additional handling of the soil.
JT950328.2DH/SDD July 28. 1995
2-21
-------
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 2 and
3 are most readily implementable because they involve only excavation, disposal, containment,
and institutional actions that are commonly used and readily implementable. Alternative 7 would
be slightly more difficult to implement because of the additional separate actions required to
acquire a portion of land and restrict access by fencing. Alternative 6 would be less
implementable if landowners were reluctant to negotiate agreements with DOE for contaminated
portions of their property. Long-term maintenance of the soil cover and fencing may also be
difficult. Alternatives 4 and 5 may be the hardest to implement because they include a treatment
process, low-temperature thermal desorption, for which full-scale effectiveness and
implementability have not been proven. Low-temperature thermal desorption is an EPA-accepted,
best demonstrated available technology, effective in removing mercury from Lower EFPC soils
in bench-scale and pilot-scale tests.
COST
Cost compares the differences in cost, including capital and operation and maintenance
costs, expressed as estimated total present-worth cost. Alternative 7 is the least expensive action
alternative. The next lowest-cost alternatives are Alternatives 6,2, and 3. Alternatives 4 and
5 are the most expensive.
STATE ACCEPTANCE
State acceptance 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. The proposed plan (DOE 1995b) presented Alternative 3, as previously
described, as DOE, EPA, and TDEC's preferred alternative. The "Selected Remedy" section
reflects a compromise of the many public comments on'the proposed plan. The "Highlights of
Community Participation" section summarizes community participation. Part 3, the
"Responsiveness Summary," summarizes and responds to comments submitted during the two
public comment periods.
JT950328.2DH/SDD July 28. 1995
2-22
-------
SELECTED REMEDY
Based on a comparative analysis of the alternatives presented in the feasibility study
(DOE 1994b), Alternative 3 is selected as the remedial action. This alternative reflects the best
balance of the evaluation criteria. The remediation goal that is protective of human health and
the environment is 400 ppm mercury.
The selected remedy addresses soil contaminated with mercury at concentrations greater
than 400 ppm by excavating and disposing of the identified highly contaminated floodplain soils.
The major components of the selected remedy include:
• The areas to be excavated include three areas at the NOAA site (Parcels #571
and #461) and one area at the Bruner's Center site (Parcel #564). Figures 2.2,
2.3, and 2.4 delineate the areas. The mercury contamination above 400 ppm in
the three areas at the NOAA site extends approximately 40 cm (16 in.) deep.
Figure 2.2 shows the 400 ppm contours for the NOAA site. No jurisdictional
wetlands at the NOAA site would be excavated. The mercury contamination
above 400 ppm in the area to be excavated at the Bruner's Center site extends to
80 cm (32 in.) deep, as shown in Figures 2.3 and 2.4. Figure 2.3 shows the 400
ppm contour for the soil from the surface to 40 cm (16 in.) deep. Figure 2.4
shows the 400 ppm contour for the soil from 40 cm (16 in.) to 80 cm (32 in.)
deep. Excavation will be conducted using standard construction machinery.
Confirmatory sampling conducted before the remedial action will further refine
the areas to be excavated.
• ~ For disposal, the excavated contaminated soil will be loaded into standard dump
trucks and transported to the Y-12 Plant. The soil will then be deposited in a
modification or expansion of an existing, state-approved, permitted, lined,
Subtitle D landfill at the Y-12 Plant. The landfill will have leachate collection
capabilities and, if necessary, any leachate collected will be pretreated before
discharge.
• The only jurisdictional wetland area affected is a 0.24-ha (0.6-acre) portion of
Wetland COE ID #8 at the Bruner's Center Site. The contaminated soil in the
wetland will be remediated through excavation and disposal. The wetland will
then be restored in the same location. No delineated wetlands at the NOAA site
will be affected by implementation of the selected remedy.
JT950328.2DH/SDD July 28. 1995
2-23
-------
\ _r« -
f^' C"\ HOLIDAY INN \
r \\""
PARCEL BOUNDARY
ASPHALT ROAD
100 YR. FLOOOPLAIN
WETLANDS
CREEK
SAMPLE LOCATION
..MERCURY CONCENTRATION > 400 ppm
GRID TIC
Science Applications
international Corporation
EAST FORK
POPLAR CREEK
OAK RIDGE, TENNESSEE
SCALE: 1 = 500'
rT950328.2DH«DD
Fig. 2.2. Mercury concentrations 0-16 in. at NOAA site.
2-24
July 26. 1995
-------
ft 34 p* 8i|/iyt I
' i i 400 ppm
GRID TIC
500
SCALE: 1" = 500'
Science Applications
in (emotional Corporatior
EAST FORK
POPLAR CREEK
OAK RIDGE, TENNESSEE
CM FU t
PUT FU |
JT950328.2DH/SDD
Fig. 2.3. Mercury concentrations 0-16 in. at Bruner's Center Site.
2-25
July 26, 1995
-------
>•—LC *12$ 5J ; Ł Pj 433 ,p. ;,4 ' ' V-s
?E5i5i II i:rJiy:3:l14b
442
P* 564
LEGEND:
...PARCEL BOUNDARY
ASPHALT ROAD
GRAVEL ROAD
.100 YR. FLOODPLAIN
WETLANDS
...CREEK
.SAMPLE LOCATION
..MERCURY CONCENTRATION > 400 pom
...GRID TIC
SCALE: T = 5001
Science Applications
international Corporator
EAST FORK
POPLAR CREEK
OAK RIDGE, TENNESSEE
CM FU I
PLOT FlŁ |
Fig. 2.4. Mercury concentrations 16-32 in. at Bruner's Center Site.
t
JT950328.2DH/SDD • 2-26
July 26, 1995
-------
• Verification sampling will ensure that all soil with mercury concentrations above
400 ppm in each of the designated areas is excavated. Results of analyzed
samples below 400 ppm will verify that excavation is complete.
• All areas excavated will be backfilled with clean soil. The clean soil will either
be transported from another area such as the DOE ORR, or nearby soil in the
same parcel will be recontoured, thereby providing fill material for the
excavation. Similar vegetation to that removed during excavation will be.
replaced at all excavated areas.
• Appropriate monitoring (sampling and analysis) of the identified areas in the
Lower EFPC floodplain will be conducted to ensure effectiveness of the
remediation.
DOE will monitor to detect any future residential use of the shallow soil horizon
groundwater. In the unlikely event such use occurs, DOE will mitigate, as appropriate, any risk
associated with such use.
Implementation of the selected remedy is estimated to cost $22.3-27.9 million. A
breakdown of the cost components is provided in Table 2.2. The cost is in escalated dollars.
Design includes the design, review, and permitting of the cleanup activities. Cleanup includes
excavation and drying of the identified soil, transportation of the soil to the landfill, acceptance
Table 2.2. Costs components of the selected remedy
,. Comtponcnl
Design
Cleanup
Indirect and overhead
O&M
Contingency
Total
Cost (SmiiJion)
1.4
12.1
5.0
3.8
3.6
22.3-27.9
O&M = operating and maintenance
JT950328.2DH/SDD July 28. 1995
2-27
-------
at the landfill, and upgrades to the landfill leachate storage system. The indirect and overhead
value includes costs for project management, administrative support, and overhead. The O&M
value consists of the cost of operating and maintaining the landfill leachate storage system and
monitoring the floodplain for 5 years. The contingency value allows for unforeseen costs not
included in the design, cleanup, indirect and overhead, and O&M costs.
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 alternative treatment
technologies or resource recovery technologies to the maximum extent practicable. Finally, the
statute includes a preference for remedies that employ treatment that permanently and
significantly reduce the toxicity, mobility, or volume of hazardous substances as their principal
element.
PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
The selected remedy is protective of human health and the environment through removal
of the principal contaminated soils in the 100-year floodplain of Lower EFPC. In so doing, the
risk is reduced for human ingestion of contaminants and for uptake of contaminants into biota.
COMPLIANCE WITH ARARS
All alternatives considered for Lower EFPC were in compliance with identified ARARs.
The selected remedy meets all ARARs, which are listed in Table 2.3.
Chemical-specific ARARs for the site include maximum containment levels (MCLs) (40
Code of Federal Regulation (CFR) 141) and secondary MCLs for drinking water promulgated
and legally enforceable under Tennessee law (TDEC 1200-5-1-12). These are relevant and
appropriate for groundwater below the shallow soil horizon. Manganese concentrations exceed
secondary MCLs in the Oak Ridge area because background concentrations are high. Therefore,
the secondary MCL for manganese is excepted from the relevant and appropriate requirements
for groundwater.
JT9503:8.2DH;SDD • July 28. '199S
2-28
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Table 2.3 Chemical-, location-, and action-specific ARARs and TBC guidance for sitewide Alternative 3 at EFPC—Sewer Line Beltway
Actions
Requirements
Citation
K)
K)
Chemical-specific
Presence of contaminanis in
deep groundwater
Location-specific
Presence of wetlands as
defined in Executive Order
11990 §7(c)
Presence of jurisdictional
wetlands as defined in
40 CFR 230.3(1) and
33 CFR 328.3(b)
Within area encompassing
or affecting waters of the
state of Tennessee as
defined in TCA
69-3-103(32)
Must comply with SDWA MCLs and SMCLs for groundwater below 20 ft from the
soil surface - relevant and appropriate
Whenever possible, actions involving federal activities and programs affecting land
use 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. Discharges for which there is a practicable alternative with less adverse
impacts or those which would cause or contribute to significant degradation are
prohibited - applicable
Must comply with the general and specific terms and conditions of NWP 13 (Bank
Stabilization), NWP 14 (Road Crossings), NWP 18 (Minor Discharges), NWP 38
(Cleanup of Hazardous and Toxic Waste), or others if authorized by COE for minor
adverse environmental effects - applicable
Must comply with the substantive requirements of the individual permitting process
for alterations to "waters of the U.S." which cause more than minimal individual or
cumulative adverse environmental effects - applicable
Discharge of "substances" into the waters of the state which "will result or will
likely result in harm, potential harm or detriment to the health of animals, birds,
fish, or aquatic life" is prohibited - applicable
40 CFR 141
TDEC 1200-5-1-
12
Executive Order 11990;
10 CFR 1022
Clean Water Act §404
40 CFR 230
33 CFR 323
33 CFR 330, Appendix A
33 CFR 325.1
TCA 69-3-101 el seq.
-------
Table 2.3. (continued)
Actions
Requirements
Citation
u>
o
Within "lowland and
relatively flat areas
adjoining inland and coastal
waters and other floodprone
areas...." [Executive Order
11988 §6(c)]
Presence of federally
owned, administered, or
controlled prehistoric or
historic resources -or- the
likelihood of undiscovered
resources
Must comply with the substantive requirements of the aquatic resource alteration
individual or general permits for activities such as noncommercial sand and gravel
dredging, bank stabilization, minor road crossings, wetlands disturbance -
applicable
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 during federal activities involving acquisition,
management, and disposition of lands and facilities or conducting any federal
activities and programs affecting land use. The potential effects of actions in flood-
plains shall be evaluated and consideration of flood halards and floodplain manage-
ment ensured. If action is taken in floodplains, alternatives that avoid adverse
effects and incompatible development and .minimize potential harms shall be
considered - applicable
Cultural resources included in or eligible for inclusion in the National Register of
Historic Places (36 CFR 60) or National Historic Landmark Program (36 CFR 65)
must be identified - applicable
Action(s) that will affect such resources must be identified and alternatives to the
aclion(s) examined and considered - applicable
When alteration or destruction of a resource is unavoidable, steps must be taken to
minimize or mitigate the impacts - applicable
When alteration or destruction of a resource is unavoidable, steps must be taken to
preserve records and data of the resource - TBC
Consultation with SHPO should be conducted if cultural resources are inadvertently
discovered during remediation activities - TBC
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 - TBC
TDEC 1200-4-7
Executive Order 11988
10 CFR 1022
National Historic
Preservation Act (16
USC 470a-w
Executive Order 11593
36 CFR 800
16 USC 470f
36 CFR 800
-------
Table 2.3, (continued)
Actions
Requirements
Citation
Presence of archaeological
resources on public land
Presence of archaeologic or
historic resources
Action-specific
Construction/excavation/
transport of soils
Surface water control
Waste pile
Treatment and disposal of
decontamination/dewater-
ing fluids
Steps must be taken to protect archaeological resources and sites for any action
involving alteration of terrain which might cause irreparable loss or destruction of
significant scientific, prehistoric, historic, or archaeologic data - applicable
A survey of affected areas for resources and data should be conducted and steps
taken to recover, protect, and preserve data therefrom or request that DOI do so;
the Secretary of Interior must be advised of the presence of the data - TBC"
Must take- reasonable precautions to prevent paniculate matter from becoming
airborne during handling or transporting of any materials - applicable
Comply with the substantive requirements of the stormwater permitting process for
discharges associated with construction activity, including clearing, grading, and
excavation that result in a disturbance of 5 acres or more total land and implement
good site planning and BMPs to control stormwater - applicable; relevant and
appropriate for less than 5 acres
Implement a BMP to address each component of a system capable of causing a
release of significant amounts of hazardous or toxic pollutants to waters of the U.S.
- applicable
All cost-effective and reasonable BMPs for nonpoint source control shall be
implemented - applicable
Pile used for the storage of paniculate RCRA hazardous waste must be managed to
control wind erosion and surface water runoff - relevant and appropriate to soil
containing RCRA constituents
A person who generates solid waste must determine whether that waste is hazardous
using various methods, including TCLP or application of knowledge of the
hazardous characteristics of the waste based on information regarding the materials
or processes used - applicable to the mercury-contaminated solid waste contained in
the soil.
Archaeological Resources
Recovery Act of 1979
(16 USC 470aa-ll);
43 CFR 7
Archaeological and
Historic Preservation Act
(16USC469a-c)
TDEC 1200-3-8-.01
TDEC 1200-4-10-.05
40 CFR 125.104
40 CFR 264.250(c);
TDEC 1 200- 1-11 -.06(-
40CFR262.il
TDEC 1200-1-11-
•03(1 )(b)
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Table 2.3. (continued)
Actions
Requirements
Citation
O
a
Direct discharge to surface
water body
Discharge to publicly
owned treatment works
(POTW)
Must meet water quality criteria for the designated use - relevant and appropriate TDEC 1200-4-3;
TDEC 1200-4-4
Must meet NPDES .permit limitations for any discharge via permitted outfalls -
applicable
Pollutants that pass through the POTW without treatment, interfere with POTW
operation,- or contaminate POTW sludge are prohibited - applicable
TDEC 1200-4-5
40 CFR 403.5
40 CFR 403.5(d)
Disposal of solid waste
Discharge must comply with local POTW pretreatment standards - applicable
A person who generates solid waste must determine whether that waste is hazardous 40 CFR 262.11
using various methods, including TCLP or application'of knowledge of the TDEC 1200-1-11-
hazardous characteristics of the waste based on information regarding the materials .03(l)(b)
or processes used - applicable
'Although administrative and procedural requirements are not ARARs for on-site CERCLA activities, adherence to these steps is strongly recommended by EPA because of the
effectiveness of these procedures in identifying and protecting sensitive resources.
ARARs = applicable or relevant and appropriate requirements
BMPs = best management practices
CFR = Code of Federal Regulations
COE = U.S. Army Corps of Engineers
DOI = U.S. Department of the Interior
EPA = U.S. Environmental Protection Agency
ft = foot
LDRs - land disposal restrictions
MCL = maximum contaminant level
MOA = memorandum of agreement
NPDES = National Pollutant Discharge Elimination System
POTW = publicly owned treatment works
RCRA = Resource Conservation and Recovery Act
SDWA = Safe Drinking Water Act
SHPO = State Historical Preservation Officer
SMCL = secondary maximum containment level
TBC = to be considered
TCA = Tennessee Code Annotated
TCLP = Toxicity Characteristic Leaching Procedure
TDEC = Tennessee Department of Environment and Conservation
USC = United States Code
-------
Location-specific ARARs include requirements to avoid or minimize adverse impacts to
wetlands. When such impacts cannot be avoided, mitigation and compensation are required. The
selected alternative involves disturbance of approximately 0.24 ha (0.6 acre) of wetlands at the
Bruner Center location. These wetlands primarily serve as wildlife habitat, but also have low
floodflow attenuation and sediment retention functions. The disturbed area will be remediated
and restored. A wetlands and floodplain assessment was performed, per 10 CFR 1022, as part
of the remedial investigation, after the wetlands were delineated by the U.S. Corps of Engineers
(DOE 1994a). Best management practices (e.g., sediment barriers and erosion control measures)
and mitigation measures (e.g., wetlands replacement) discussed in the wetlands and floodplain
assessment will be followed.
Since the remedial action will occur in a floodplain, actions must minimize any
unavoidable adverse impacts. A notice of floodplain and wetlands involvement was published
for the actions in the Lower EFPC wetlands and floodplain on October 4, 1993 (58 Federal
Register 51623-4). A floodplain assessment was performed (DOE 1994b) as mentioned above.
A statement of findings was subsequently published in compliance with review requirements for
floodplains (10 CFR 1022). The finding showed there is no practicable alternative to the
proposed action. The Statement of Findings is provided in the feasibility study (DOE 1994b) and
will be published in the Federal Register before the action is initiated. It specifies several
measures that DOE will take to minimize potential harm within the affected floodplain. These
include, but are not limited to implementation of soil erosion and sediment control measures;
avoidance of stream obstruction; restoration of original contours; haul roads not to follow the
shoreline; minimization of disturbance; and use of mats, low-pressure ground machines, or
extended-reach excavating equipment.
Other location-specific ARARs are related to cultural resources and would be invoked
only if discoveries of cultural resources should be made during remedial activities.
Action-specific ARARs for remedial action at Lower EFPC include requirements for
surface water controls using site planning and best management practices to minimize adverse
effects from erosion and stormwater discharges into the creek, which could result from activities
such as clearing, grading, and excavation. Precautions must be taken to prevent fugitive dust that
may result from handling and transport of soils from becoming airborne (TDEC 1200-3-8-.01.
Best management practices will be followed to address minimizing the potential release
of hazardous substances into surface waters (40 CFR 125.104, TDEC 1200-4-3-.06), to control
stormwater discharges (40 CFR 122, Tennessee Code Annotated 69-3-108 et seq), and for
JT950328.2DH/SDD Ju,y 28. 1995
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nonpoint source controls. These practices will be identified by complying with the substantive
requirements of the storm water permitting process (40 CFR 122, TDEC 1200-4-10-05).
Waste generators are required to determine whether the waste is hazardous (40 CFR
262.11, TDEC 1200-1-11-.06). Previous sampling has indicated that the soils at Lower EFPC
are not hazardous as defined by Resource Conservation and Recovery Act. Excavated soils will
be disposed of in a solid waste landfill at the Y-12 Plant on ORR as a special waste (TDEC 1200-
1-7-.01 et seq.).
COST EFFECTIVENESS
Actions under CERCLA must consider the estimated total present-worth costs of the
alternatives. Alternative 3 is cost effective for the protection of human, health and the
environment.
USE OF PERMANENT SOLUTIONS TO THE MAXIMUM EXTENT PRACTICABLE
Because treatment of the soils was not practicable, this remedy does not satisfy the
statutory preference for treatment of media containing hazardous substances. However, it does
provide long-term effectiveness and permanence through containment systems for untreated waste.
PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
Treatment of the principal threat from the soils was not found to be practicable based
on the large volume of low concentrations of material. Therefore, this remedy does not satisfy
the statutory preference for treatment as a principal element of the remedy. .However, this
remedy will result in remediation of hazardous substances and allows unlimited use of, and
unrestricted exposure to, the Lower EFPC OU.
DOCUMENTATION OF SIGNIFICANT CHANGES
The preferred alternative presented in the proposed plan (DOE 1995b) was Alternative
3. Extensive public comment on the proposed plan indicated a need to reassess the remediation
goal for mercury. Many commentors argued to increase the cleanup level, and some commentors
argued to lower it. Several technical arguments were advanced, which challenged the
conservative nature of the risk assessment. In response to the public comments, including those
JT9S0328.2DH/SDD July 18. 1995
2-34
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requesting a more conservative cleanup level, DOE revisited the assumptions used in the
.derivation of the remediation goal for protection of human health and the environment. This
reassessment is part of the risk management process for EFPC.
REASSESSMENT OF THE HUMAN HEALTH REMEDIATION GOAL FOR LOWER
EFPC SOILS
DOE, in developing the remediation goal for mercury in soil, attempted to derive the
most appropriate, scientifically valid, and protective target concentration possible. A value of
180 ppm was developed to protect children (the most sensitive receptor group) from direct
exposure to mercury through inadvertent soil ingestion and dermal contact (DOE 1994c). Several
public comments indicate a preference for a less conservative remediation goal for mercury in
soils. Residents urged DOE and EPA to derive a remediation goal based more on measures of
central tendency (i.e., closer to average values) rather than high end (i.e., upper bound) exposure
estimates and toxicity.
The bioavailability of mercury in EFPC soils, and the EPA oral reference dose (toxicity
measure) for mercury species significantly influence the development of the remediation goal for
mercury. The magnitude of the remediation goal estimate is inversely proportional to the
bioavailability factor and directly proportional to the reference dose. That is, the greater the
availability of mercury in soil, the greater the uptake and dose, and the lower the target cleanup
level needs to be (i.e., greater exposure means greater need for protection). Conversely, the
higher the value of the oral reference dose for mercury species under evaluation, the less toxic
the form of mercury and the higher the target cleanup level may be.
During the remedial investigation, DOE had conducted a reevaluation of the available
toxicity data of mercury as part of the baseline risk assessment (DOE 1994a). The EPA oral
reference dose for mercury was based on exposure of laboratory animals to mercuric chloride,
a highly mobile (available) form of mercury not found in EFPC. An alternate reference dose was
derived for mercuric sulfide and submitted to the EPA Environmental Criteria Assessment Office
(Cincinnati, Ohio). EPA Environmental Criteria Assessment Office reviewed the analysis
submitted and decided that data were insufficient to support the acceptance of an alternate
reference dose for mercuric sulfide. The remediation goal was, therefore, derived using a
conservative oral reference dose value of 0.0003 mg/kg-day published in the EPA Health Effects
Assessment Summary Tables for Fiscal Year 1993-94 (EPA 1992a). Note that the oral reference
dose for mercury had been withdrawn from the EPA Integrated Risk Information System [(EPA
1993), the primary source of EPA toxicity data] pending further review.
JT950328.2DH/SDD July 28. 1995
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As noted previously, DOE derived the remediation goal of 180 ppm taking into
consideration bioavailability of mercury species in EFPC floodplain soil. Data on the
bioavailability of mercury (i.e., mercuric sulfide and elemental mercury) in EFPC were
empirically derived from leaching/availability studies conducted by Oak Ridge National
Laboratories on contaminated samples of EFPC soil. Data from these studies were aggregated
and statistically evaluated. The simulation was also used to examine the uncertainty surrounding
the estimate of bioavailability of mercury species (DOE 1994c). The analysis generated a
probability distribution that graphically depicts the range of possible values for mercury
bioavailability in EFPC soils. The bioavailability factor selected in deriving the remediation goal
of 180 ppm for mercury (see equation 1 DOE 1994c) was 30 percent and corresponds.
approximately to the 94th percentile of the probability distribution! • • ', .
At this point in the planning process, DOE and EPA have made a risk management
decision to use a bioavailability factor for mercury corresponding to the 85th percentile of the
probability distribution. The 85th percentile of the distribution corresponds to a bioavailability
factor of 10 percent and results in a calculated remediation level of approximately. 400 ppm of
soil. Given that insoluble/unavailable forms of mercury predominate in EFPC, the 85th
percentile of the probability distribution (i.e., 10 percent bioavailability) still affords considerable
protection to human health. It is still a more conservative value than some commentors felt was
justified, but not as conservative a value as requested by others. It is, however, scientifically
defensible and sufficiently protective of the most sensitive receptor group (i.e., children) for
direct contact with soils.
REASSESSMENT OF THE ECOLOGICAL REMEDIATION GOAL FOR LOWER EFPC
SOILS
, The preferred remedial alternative identified in the proposed plan included an ecological
remediation goal for mercury in soil of 200 ppm. The remedy selected in the ROD contains an
ecological remediation goal for mercury in soil of 400 ppm. The increase in the remediation goal
is based on the determination that the harm that would be caused to ecological receptors in the
short-term from removal of soil contamination in the 200-400 ppm range outweighs the short-
and long-term benefits of removing this soil because it would destroy valuable parts of the
ecosystem, including wetlands, hardwood forests, and associated organisms.
DOE believes that further justification for the increase in the remediation goal is the
conservative nature of the ecological risk assessment, which DOE believes tended to overstate
the risk posed by contaminants.
TOS0328.2DH/SDD July 28. 1995
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SUMMARY OF CHANGES
Given the extensive knowledge of the EFPC soils, a change in the overall remediation
(cleanup) goal from 180 to 400 ppm protects human health and the environment. The effect this
increased remediation goal has on the proposed plan's preferred alternative is shown in Table 2.4
and described here:
Table 2.4. Comparison of impacts of remediation goals of 180 ppm vs 400 ppm,
EFPC for Selected remedy
Impact
Cost (S million)
Volume extracted (m3)
Area impacted (hectares)
Wetlands area impacted (hectares)
Time to complete (weeks)
Dump truck loads
Area fenced (hectares)
Area capped (hectares)
Transportation injuries to worker1
Transportation fatalities to worker"
Transportation injuries to the community2
Transportation fatalities to the community6
Construction injuries to worker
Construction fatalities to workerb
Total injuries
Total fatalities
Remediation Poal (ppra)
180
36-78
41,300
7.3
0.6
82
6,750
0
0
0.01
0.005
0.3
0.02
10.3
0.008
-11
0.1
400
22-28
7,646
2.47
0.25
26
1,000
0
0
0.0018
0.0010
0.052
0.0034
5.15
0.038
5.20
0.043
'Numbers < 1 indicate that injury is unlikely to occur over the remedial action activity period.
"Numbers < 1 indicate that a fatality is unlikely to occur over the remedial action activity period.
$ = dollar
EFPC = East Fork Poplar Creek
m = meter
ppm = parts per million
JT950328.2DH/SDD
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July 28. 1995
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• With a remediation goal of 400 ppm, the total identified in situ volume of
floodplain soils to be excavated is 7,650 m3 (10,000 yd3), comprised of four
areas (three areas at the NOAA site and one area at the Bruner's Center site).
In comparison, a remediation goal of 180 ppm corresponded to a soil volume of
41,300 m3 (54,000 yd3) in six different areas.
• Contaminated soil would be disposed of in a state-approved landfill at the Y-12
Plant whether the remediation goal were 400 or 180 ppm. The volume requiring
transportation and landfill space are much lower if the remediation goal is 400
ppm than if the remediation goal is 180 ppm (see volumes in previous bullet).
• A remediation goal of 400 ppm means that only 0.24 ha (0.6 acres) of low-
quality wetlands would be excavated and would require .mitigation. In
comparison, a remediation goal of 180 ppm corresponded to excavation of 0.6
ha (1.5 acres) of low- and high-quality wetlands.
• The verification sampling method used does not depend on the remediation goal.
However, since a smaller area would be excavated with a remediation goal of
400 ppm than with a remediation goal of 180 ppm, fewer samples overall would
be required.
• Backfilling excavations would occur independently of the remediation goal.
Again, however, a smaller Volume of backfill would be required for the 400 ppm
.remediation goal than for the 180 ppm remediation goal.
• The revised Alternative 3 now includes appropriate monitoring (sampling and
analysis) of Lower EFPC media to ensure effectiveness of the remedial action.
This significant change is a logical outgrowth of responding to public comments. An
additional formal public comment period is not required for these changes in the selected remedy.
REFERENCES
DOE (U.S. Department of Energy). 1992. Federal Facility Agreement for the Oak Ridge
Reservation, DOE/OR-1014, U.S. Environmental Protection Agency Region IV, Atlanta,
JT950328.2DH/SDD Ju|y 28, 1995
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GA, U.S. Department of Energy, Oak Ridge Operations, Oak Ridge, TN, and
Tennessee Department of Environment and Conservation, Nashville, TN.
DOE. 1994a. East Fork Poplar Creek—Sewer Line Beltway Remedial Investigation Report,
DOE/OR/02-1119&D2. Oak Ridge, TN.
DOE. 1994b. Feasibility Study for the Lower East Fork Poplar Creek—Sewer Line Beltway,
DOE/OR/02-1185&D2, Volumes 1 and 2. Oak Ridge, TN.
DOE. 1994c. Addendum to the East Fork Poplar Creek—Sewer Line Beltway Remedial
Investigation Report, DOE/OR/02-1119&D2/A1/R1. Oak Ridge, TN.
DOE. 1995a. Remedial Goal Options for Mercury in Sediment of East Fork Poplar Creek, Oak
Ridge, Tennessee, DOE/OR/01-1342&D2. Oak Ridge, TN.
DOE. 1995b. Proposed Plan, East Fork Poplar Creek—Sewer Line Beltway, Oak Ridge,
Tennessee, DOE/OR/02-1209&D3. Oak Ridge, TN.
Eisler, R. 1987. Mercury Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review.
Biological Report 85(1.10), Fish and Wildlife Service, U.S. Department of the Interior,
Patuxent, MD.
EPA (U.S. Environmental Protection Agency). 1992a. Health Effects Assessment Summary Tables
(HEAST). Annual Update and Supplement Nos. 1 and 2, OHEA ECAO-821. Office of
Health and Environmental Assessment, Office of Research and Development,
Washington, D.C.
EPA. 1992b. Framework for Ecological Risk Assessment, EPA 630/R-92/001. Risk Assessment
Forum, Washington, D.C.
EPA. 1993. Integrated Risk Information System (IRIS). U.S. Environmental Protection Agency
On-line Database of Toxicity Measures. Office of Research and Development,
Environmental Criteria and Assessment Office, Cincinnati, Ohio. Electronic Mail
Account Information via TOXNET, National Library of Medicine, Bethesda, MD.
JT950328.2DH/SDD July 28. 1995
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Hildebrand, S., J. Huckabee, F. Diaz, S. Janzen, J. Solomon, and K. Kumar. 1980.
Distribution of Mercury in the Environment at Almaden, Spain, ORNL/TM-7446. Oak
Ridge, TN.
Hinzman, R. L. (Ed.). 1993. Second Report on the OakRidge Y-12 Plant Biological Monitoring
and Abatement Program for East Fork Poplar Creek, Y/TS-888. Oak Ridge National
Laboratory, Oak Ridge, TN.
Loar, J. M. (Ed.). 1992, First Report on the Oak Ridge Y-12 Plant Biological Monitoring and
Abatement Program for East Fork Poplar Creek, Y/TS-886. Oak Ridge National
Laboratory, Oak Ridge, TN. -
Seheuhammer, A: M. 1988. "Chronic Dietary Toxicity of Methyl/mercury in the Zebra Finch,
Poephila guttata." Bull. Environ. Contam. Toxicol.
Suter, G. W. II, B. E. Sample, D. S. Jones, and T. L. Ashwood. 1994. Approach and Strategy
for Performing Ecological Risk Assessments for the U.S. Department of Energy's Oak
Ridge Reservation: 1994 Revision, ORNL ES/ER/TM-33/RI. Oak Ridge, TN.
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PART 3. RESPONSIVENESS SUMMARY
TO50328.2DH/SDD . July 28, 1995
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RESPONSIVENESS SUMMARY
This responsiveness summary documents formal public comments on the Lower East
Fork Poplar Creek Proposed Plan made during the official Lower EFPC Public Meeting and
those submitted in writing during the public comment periods. The official public meeting was
held January 26, 1995, at Pollard Auditorium in Oak Ridge, Tennessee. The first public
comment period started January 9, 1995, and ended February 22, 1995. The second public
comment period started June 14, 1995, and ended July 13, 1995. This responsiveness summary
also presents DOE's response to all comments received.
Based on the evaluation of the remedial action alternatives for Lower EFPC, Alternative
3 is the selected remedy. This selected remedy is referred to in the feasibility study and is the
preferred alternative in the proposed plan. The remedial alternative, as described in the
feasibility study and proposed plan, involved excavating all soil in the floodplain that contains
more than 180 ppm mercury and disposing of the soil in a Y-12 Plant-permitted landfill. The
selected remedy has since been changed. The decision summary of this ROD presents the same
remedial alternative but with, a remediation goal of 400 ppm mercury instead of 180 ppm.
This responsiveness summary serves three purposes. First, it informs DOE, EPA, and
TDEC about 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 report is prepared pursuant to the terms of the 1992 Federal Facility Agreement
among DOE, EPA, and TDEC, as well as other requirements, including:
• CERCLA as amended by SARA, 42 United States Code, Section 9601, et seq.;
• NCP, 40 Code of Federal Regulations, Part 300; and
• Community Relations in Superfund, A Handbook, EPA/540/R-92/009, January
1992.
After reviewing the written comments and the transcript of verbal comments, DOE
grouped comments according to common issues. DQE summarized each comment and prepared
a response to each issue.
JT950328.2DH/SDD July 2g. 1995
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A corresponding comment code is provided at the end of each comment. Numbers that
stan with "028" correspond to written comments submitted to DOE during the public comment
periods. The number is the log number used by the Information Resource Center, the repository
that maintains the Administrative Record and has copies of all comments received. Codes in the
form of PMxx (where xx denotes a two-digit number) correspond to verbal comments from the
public meeting transcript. A list of commentors and the corresponding comment codes are
provided in Appendix A.
COMMENTS AND RESPONSES
First public comment period (January 9, 1995—February 22, 1995)
and first official public meeting (January 26, 1995)
ISSUE 1: THE REMEDIATION GOAL IS TOO LOW
Several commentors say that EPA's risk assessment methodology is too conservative and
that this results in an overly conservative remediation goal, an overly conservative approach to
the protection of human health and the environment, and that implementing cleanup based on a
remediation goal of 180 ppm for mercury is far too conservative. Some commentors
recommended specific remediation goals. Other commentors stated reasons that 180 ppm is too
low.
Comment: Fred Maienschein said the current remediation goal is too conservative and
submitted a list of scientific articles that support increasing the remediation goal. Maienschein
agrees it is necessary to be conservative, but said DOE is extremely conservative without
indicating how conservative the proposal actually is. In the public meeting, Maienschein
proposed a remediation goal of 2,600 ppm, which would provide a safety factor of 50,000 to
100,000. John and Kathleen Shacter expressed support for Maienschein's position. (028564,
PM01.PM19, 028453)
Comment: Alfred Brooks recommends that, for risk management purposes, the oral
absorption factor be set at the site-specific value of 0.01 (1 percent) and the corresponding soil
remediation goal be set no lower than 1,200 ppm except in areas showing exceptionally high
bioavailability. Brooks supported his position with a petition containing 13 signatures. He
further stated that, in his professional opinion, the EPA risk assessment numbers are wrong.
They provide a conservative factor of approximately 500,000 to a million, a level of security
JT950328 2DH/SDD Ju|y 28. 1995
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much larger than many risks associated with people's everyday lives. He also wrote, "The
bioavailability factor for mercury in EFPC soils and sediments [should] be set at 5 percent, the
average value of the ORNL measurements. The dermal absorption factor should be set at zero.
The RGO should be set at 1,200 ppm." (028347, 028591, 028674, PM02, PM32, PM39)
Comment: William J. Wilcox said he supports a remediation goal of 1,200 ppm
mercury because the 180 ppm goal was set using the solubility of mercuric chloride, which is
3;600,000 times more soluble than the mercuric sulfide believed to be in the EFPG soil.
(028744, PM10)
Comment: Fred Sweeton said he advocates raising the remediation goal to at least 1,200
ppm mercury because of the very large safety factor used in setting the 180 ppm mercury
remediation goal. (028768)
Comment: The Friends of Oak Ridge National Laboratory said that the proposed action
level of 180 ppm mercury for soil in the EFPC watershed is too low by a factor of at least four
(i.e., the remediation goal should be at least 720 ppm). (028650, PM20)
Comment: Robert W. Peelle recommended following the DOE proposed plan but setting
the remediation goal at about 600 ppm mercury except in any areas where more than 10 percent
of the mercury is in a relatively soluble form. He wrote, "An appropriate compromise would
be to choose a bioavailability percentage (like 10 percent) that bounds results for almost all
samples and provide exceptions for those areas where measured bioavailability values exceed the
bound. Accept 30 percent or the measured percentage in those cases. I propose basing the
remediation goal on the 10 percent value." (028788, PM07)
Comment: Ellen D. Smith, Oak Ridge Environmental Quality Advisory Board, said that
the human health remediation goal of 180 ppm mercury is unnecessarily conservative. However,
she does support remediation in areas where the highest concentration of contaminated material
exists. She states that the contamination in the floodplain and creek sediment poses no real risk
to human health because the mercury is primarily in the sulfide form, which is not only low in
toxicity and bioavailability, but also quite chemically stable. She further states that the mercury
contamination is buried 6-12 in. deep, further reducing potential exposure. Jane Shelton
submitted a letter supporting the Environmental Quality Advisory Board position. (028767,
PM03, 028745)
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Comment: James Johnson wrote that the 180 ppm remediation goal is too low a trigger
for remedial action. "My impression is that the 180 ppm number is based on a maximum excess
risk to an exposed individual of 10^*. To make a comparison, one needs an estimate of the
exposed population. There has been little discussion that I remember helpful in arriving at such
an estimate." (028675)
Comment: Herman Weeren wrote that the proposed plan greatly overstated the risk to
human health. (028563)
Comment: Murray W. Rosenthal said that the mercury concentration of 180 ppm that
DOE proposes as the basis for soil removal is lower than it needs to be. He said that changing
the estimate of the limiting mercury concentration from an excessively conservative value to one
that is lower, but still quite conservative would seem to be prudent. (028416)
Comment: H. Richard and B. Jane Hicks said that Alternative 3 is probably overly
conservative and that a large arbitrary factor has been built in to account for unknowns.
(028345)
Comment: A. D. Ryon supported previous commentors that the 180 ppm mercury is
too low, based on the strong evidence that the mercury exists as a very insoluble sulfide.
(028820)
Comment: Ann and Douglas Macdonald agreed with other commentors that risk
estimates err on the very conservative side. (028346)
Comment: Oak Ridge City Council members said they are uncertain that the proposed
180 ppm remediation goal is the appropriate cleanup threshold to achieve unrestricted future use.
The council recommends a reevaluation to set the remediation goal to the highest possible level
without jeopardizing human health or preventing unrestricted future land use. (028789)
Response: Many Oak Ridge citizens said that the remediation goal derived for mercury
in soil is overly conservative (i.e., the cleanup concentration proposed by DOE is too low). DOE
attempted to derive a scientifically valid and protective target concentration that took into
consideration the best available information. A value of 180 mg mercury per kg of soil (ppm)
was developed for the protection of children (the most sensitive receptor group) from direct
exposure to mercury via inadvertent soil ingestion and dermal contact (DOE 1994c). The value
JT950328.2DH/SDD ' Ju|y 28. 1995
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of 180 ppm was based on an understanding of the mercury species present and bioavailability in
Lower EFPC soils.
The remediation goal of 180 ppm was developed to protect against adverse
noncarcinogenic effects of chronic exposure to mercury. One member of the Oak Ridge
community was under the impression that the remediation goal was "based on a maximum excess
risk to an exposed individual of 1 X 10"4" and that a population estimate was required to make
a comparison between remediation goals. This is not the case. Mercury is not a carcinogen and,
according to EPA methods, the results of risk assessment for noncarcinogens are not expressed
in terms of incremental or excess risk to an exposed population.
A number of factors affect the magnitude of the estimate of the remediation goal. Two
factors of particular importance are the bioavailability and toxicity of the form of mercury to
which receptors are exposed. A considerable amount of work was conducted by DOE and Oak
Ridge National Laboratory (ORNL) to determine the nature of mercury contamination in Lower
EFPC soil. The weight of evidence indicated that insoluble inorganic forms of mercury, such
as mercuric sulfide, predominate in Lower EFPC. The toxicity and bioavailability of these forms
of mercury are considerably less than that for mercuric chloride, the form of mercury that was
used as the basis for derivation of the EPA reference dose (RfD) used in the risk assessment.
DOE and ORNL derived an alternate RfD for mercuric sulfide and submitted the results
of this assessment to the EPA Environmental Criteria Assessment Office (Cincinnati, Ohio). The
EPA Environmental Criteria Assessment Office reviewed the analysis and decided that data were
insufficient to support the acceptance of an alternate RfD for mercuric sulfide. Given that
receptors are potentially exposed predominantly to insoluble inorganic forms of mercury in Lower
EFPC, not mercuric chloride, 'he RfD used in the risk and in the derivation of the remediation
goal was very conservative. This RfD incorporated a large "safety factor" (i.e., uncertainty
factor) that affords a very high degree of protection and conservatism for receptors exposed to
insoluble forms of mercury. However, EPA directives did not permit modification of the RfD
for mercuric chloride in the risk assessment, thus this extra degree of conservatism remains in
the derivation of the remediation goal.
The bioavailability of mercury directly influences the magnitude of the dose estimates.
The lower the bioavailability, the lower the dose experienced by receptors and the higher the
remediation goal. Data on bioavailability were empirically derived from leaching/availability
studies conducted by ORNL. The data from these studies were aggregated and statistically
evaluated to determine an appropriate measure for use in deriving the remediation goal. Monte
JT950328.2DH/SDD July 28, 1995
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Carlo simulation was also used to explore the uncertainty surrounding the estimate of
bioavailability of mercury species (DOE 1994c).
Many members of the Oak Ridge community expressed the opinion that the 30 percent
estimate of bioavailability used in the derivation of the remediation goal was excessively
conservative (i.e., too high). A number of individuals recommended use of a value of 0.01
(1 percent). Another member of the community recommended a compromise value of 10 percent,
except in those regions of the creek where "measured" bioavailability values exceed 10 percent.
Based on use of these alternate bioavailability factors, members of the community recommended
remediation goals above 180 ppm; ranging to 2,600 ppm mercury.
The 30 percent bioavailability factor used by DOE corresponds approximately to the 95th
percentile of the distribution (i.e., probability distribution) of possible bioavailability values for
mercury in Lower EFPC. The value of 30 percent is a conservative value in keeping with
recommendations made for remediation at mercury mining sites under the purview of EPA
Region IX and the state of California.
In this ROD, a risk management decision has been made to use a bioavailability factor
of 10 percent for mercury in Lower EFPC soils. It is important to recognize that the
bioavailability of mercury in Lower EFPC is variable and has been quantified by a statistical
distribution. Any bioavailability value selected represents a compromise; one which reflects an
understanding of uncertainty (confidence level) surrounding the estimate. The 10 percent value
corresponds to the 85th percentile of the probability distribution that was based on site-specific
measurements. It results in a calculated remediation level of approximately 400 ppm (actual
value is 438 ppm). The 10 percent value is a reasonable compromise that still affords
considerable protection to human health. It is a more conservative value than requested by some
Oak Ridge, Tennessee citizens. It is, however, scientifically defensible and sufficiently protective
of the most sensitive receptor group (i.e., children) for direct contact with soils.
As recommended by Mr. Peelle, any areas shown to have higher bioavailability may be
considered for a lower remediation goal.
ISSUE 2: REMEDIATION GOAL IS TOO HIGH
Some people said they are worried that some people in Oak Ridge have been affected
or could be affected by contamination in Lower EFPC. They said they do not necessarily agree
with others who think the remediation goal is too conservative.
/T950328.2DH/SDD Ju|y 28. 1995
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Comment: Sandra Reid wrote, "This analysis is not protective of human health."
(028786)
Comment: Ralph Hutchison, Oak Ridge Environmental Peace Alliance (OREPA), said
that selection of the remediation goal has been based on public acceptance criteria rather than on
the professional medical opinion about mercury's health impacts. (028835)
Response: The objective of the human health risk assessment was to evaluate the
potential for adverse health effects associated with exposure to chemicals released from the DOE
Y-12 Plant. DOE conducted a comprehensive evaluation based upon an understanding of the
nature and extent of contamination and the inherent toxicity of the chemicals of concern. The
assessment closely followed EPA guidelines for risk assessment and was conducted with their
concurrence and consensus.
EPA directives for the baseline risk assessment require a quantitative (numerical)
characterization of the potential for adverse health effects.' This baseline assessment is not an
evaluation based on public acceptance or medical opinion alone. The baseline risk assessment
conducted by DOE took into consideration data from past epidemiological studies. This
information was reviewed and considered as part of the risk assessment. No new epidemiological
assessments were conducted. The Agency for Toxic Substances and Disease Registry (ATSDR)
is directed by CERCLA and SARA to perform specific public health activities associated with
actual or potential exposure to hazardous substances released into the environment. At the
request of private citizens, ATSDR conducted a health consultation on the mercury remediation
goal derived by .DOE for soil in the EFPC floodplain and determined the remediation goal to be
protective of public health.
As noted above (Issue 1) and discussed in the remedial investigation, the toxicity measure
(RfD) for mercury used in the risk assessment was very conservative. Use of this RfD assumes
that receptors are exposed to mercuric chloride. The RfD for mercuric chloride is a very
conservative value in and of itself. Given that the less soluble and less bioavailable mercury
species predominate in Lower EFPC, this RfD for mercury affords an even higher degree of
conservatism and protection to human health. Similarly, the exposure assumptions were
conservative and designed to ensure protection of children, the most sensitive receptor.
JT950328.2DH/SDD July 28. 1995
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ISSUE 3: OPPOSITION TO CLEANUP
Several people said they opposed the proposed cleanup action in general.
Comment: Ardis Leichsenring said she opposes any cleanup action specific to the
Greenview Subdivision because her backyard will never be anything else except an aesthetically
pleasing backyard. (028258)
Comment: Helen Waraksa said she favors no action anywhere along the creek.
(028308)
Comment: James Westcott said that "at a time when government is stressing economy
and eliminating unnecessary spending and waste, the DOE will indeed look very .good if the creek
project is placed on the back burner and nothing more is said about it." (028318)
Comment: Michael G. Finn said he opposes the proposed cleanup. However, he said
he believes that if something must be done, removing only 10 percent of the 54,000 yd3 is
preferable to moving all of it. (028421)
Comment: Charles R. and Alma P. Schmitt said they favor no action except in areas
where mercury contamination exceeds 1,200 ppm. (028448)
Comment: Geoffrey Gleason said that EFPC is not a problem and recommends that "no
remedial action whatsoever be taken in connection with the mercury contamination of the East
Fork Poplar Creek." (028673)
Comment: Daniel Axelrod said he prefers that action be delayed 10 years while mercury
discharge from Y-12 continues to decrease. (028748)
Comment: J. Francis does not favor the proposed remedial action and favors leaving
the land undisturbed. (028759)
Comment: Elizabeth K. Busteed said she favors no action because of little risk of
leaving the mercury in place. She lives on the creek and has "no fear of the contamination."
She wrote, "to spend millions of dollars for unnecessary remediation cannot be justified,
especially when studies show it is not a great risk." (028834)
JT950328.2DH/SDD July 28. 1995
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Comment: Ann and Douglas Macdonald said they oppose the remediation of the creek
and think that too much money has been spent already on an unnecessary project. (028346)
Response: The CERCLA legislative process requires that a baseline risk assessment be
performed during the remedial investigation. This baseline risk assessment determines the risk
to human health and the environment if no cleanup action is taken. The DOE completed a
baseline risk assessment for Lower EFPC. The results indicate that an unacceptable risk to
human health and the environment would remain if no cleanup action were conducted. Based on
this assessment, CERCLA mandates that DOE conduct a cleanup action to reduce the mercury
contamination to acceptable risk-based levels. In addition, ATSDR concluded in a health
consultation that in some locations along EFPC mercury levels in soil pose a threat to public
health, especially to children who play along the creek's floodplain.
DOE reevaluated the original remediation goal of 180 ppm of mercury and recommended
to EPA and TDEC that the remediation goal be raised to 400 ppm mercury. Upon approval, the
volume of excavated soil was reduced from 54,000 yd3 to approximately 10,000 yd3. The
number of discrete areas along the Lower EFPC floodplain requiring cleanup will be reduced
from six areas to two—the areas commonly referred to as the Brunei's Center site and the NOAA
site.. This eliminates the Greenview Subdivision and three other areas. The increase in the
remediation goal also decreases the cost of the cleanup action by about $30 million. Delaying the
required cleanup for any period of time would result in increased project costs and would further
deny affected property owners the unrestricted use of their land.
ISSUE 4: FURTHER STUDIES OR MONITORING NEEDED
Several people said further studies and/or monitoring are needed to better characterize
the site, better understand the effects of mercury on humans, and confirm the protectiveness of
the remediation action.
Comment: Linda Ewald said that "we need to know really what is here and how much
and where before making a firm decision." (028746)
Comment: Alfred Brooks wrote that the EFPC feeding studies should be repeated in a
preferred species (e.g., pigs as suggested by ATSDR), monitoring of EFPC should be continued
to assess any changes in trends significant to human health, and the movement of mercury in
environmental food chains be studied further. Brooks made similar recommendations at the
public meeting. (028347, PM02, PM34)
JT950328.2DH/SDD July 28. 1995
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Comment: William Wilcox suggested in his letter that some of the taxpayer's money
be spent to obtain a direct measurement of the toxicity [reference dose] of mercuric sulfide with
rats or other animals. He urged use of pure mercuric sulfide and not an EFPC soils mixture.
Such a study "could put future remediation projects on a sounder footing and help assure that
scarce environmental dollars are spent where they are most needed...." He made similar
comments at the public meeting. (028744, PM10, PM16)
Comment: James Phelps said he is concerned that "the Scarboro community is worthy
of careful study to determine if it has any affected population due to releases from mercury and
other pollutants." He also commented on possible damage involving mercury and radionuclides.
He also urged that a recent fish kills in EFPC be explored. (028742)
t
Comment: Sandra Reid said that "... we do not know the extent of the damage on human
health because no one has done the clinical examinations of these individuals who live around
these sites to find out what has happened." She said that it is DOE's responsibility to prove that
the contaminants in Lower EFPC have not been detrimental to the health of the community, and
not the community's responsibility to prove that it is dangerous. (028786)
Comment: Ralph Hutchison, Oak Ridge Peace Alliance, said that "whatever course of
action DOE chooses at the present, it must make a commitment to revisit the decision at points
in the future, perhaps every five years, or perhaps on an expanding scale- 5, 10, 20, 30, or 50
years in the future." (028835)
Hutchison said he is also concerned that DOE develop additional information on the
forms of mercury and other contaminants and the effects on human and ecological health of
mercu*y; DOE should invest in research and development of technologies designed to address
contamination in the environment. He also echoed Sandra Reid's concern that DOE should
conduct a clinical evaluation of populations likely to have been impacted by mercury
contamination.
Response: The Lower EFPC OU is one of the most intensively studied mercury sites
in the U.S. In addition to a two-phase sampling effort involving approximately 4,000 samples,
DOE conducted several special studies on mercury speciation, wetlands, bioavailability, sediment
bioassay, etc. Even though the argument can be made that we don't know everything, there is
sufficient information to make an informed decision under the CERCLA decision process.
JT950328.2DH/SDD July 28. 1995
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The remedial investigation/feasibility study process, by necessity, is based on estimations
and assumptions. The information gathered and processed in the remedial investigation and risk
assessment has been deemed sufficient by the regulatory agencies to determine the risk to human
health and the environment from contamination present in the Lower EFPC and its 100-year
floodplain.
Regarding additional laboratory animal studies and derivation of an alternate reference
dose for mercuric sulfide, DOE does not believe the time delay in conducting such a study is
justified. Existing laboratory studies were used by DOE to argue for an alternate RfD with EPA
earlier in the process. EPA recommended that bioavailability factors be examined. This was
done, resulting in a substantial increase in the remediation goal. Further, evaluation of pure
mercuric sulfide would not be particularly useful for Lower EFPC because the mercury occurs
in several forms, albeit primarily mercuric sulfide and elemental mercury.
Some comments suggested that clinical studies be done to determine what may have
happened to people, including those residing in the Scarboro community. Studies of the potential
health risk from human exposure to mercury contamination from past DOE operations have been
conducted by the Centers for Disease Control, the Tennessee Department of Health and
Environment (Rowley 1985), and the University of Michigan (University of Michigan 1987).
These studies have concluded that residents exposed to contaminated soil are not likely to be at
an increased risk of having significantly high mercury levels.and that mercury contamination had
not resulted in any clinical problems. DOE used these studies in the CERCLA process. The
studies are available at the Information Resource Center.
Additional health, studies are currently underway to address these concerns. The
Tennessee Department of Health is conducting Oak Ridge health studies to find out if adverse
health effects may have occurred in people as a result of past DOE operations. The Tennessee
Department of Health is currently conducting a dose reconstruction study on past mercury
releases from the Y-12 Plant. The commissioner of the Tennessee Department of Health has
appointed the Oak Ridge Health Agreement Steering Panel (ORHASP), a group of expens and
area citizens, to guide and oversee the studies. DOE is providing requested information and data
to support the state of Tennessee with the Oak Ridge health studies.
In addition, at the request of private citizens, ATSDR has conducted health consultations
to evaluate public health issues related to the current contamination in EFPC and the remediation
goal derived by DOE. ATSDR will also be holding a science panel meeting to develop technical
papers on current methods for determining the bioavailability of mercury compounds in soil
JT9503:8.:DH.'SDD July 2t. 1995
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matrices and on the development of a standardized site-specific soil bioassay protocol for
determining the bioavailability of mercury in soil. Finally, DOE and EPA have, on several
occasions, explained at public meetings that the risk assessment process used under CERCLA
focuses on determining a remediation goal (cleanup level) which will be protective once
implemented; it does not focus on the probabilities of past harm. In the risk assessment process,
multiple contaminants are considered and the effects of these multiple contaminants are assumed
to be additive.
ISSUE 5: TRAFFIC AND CONSTRUCTION RISKS AND CONCERNS
Many who attended the public meeting or who submitted written comments said they
were concerned about increased truck traffic, related transportation risk, and'risk to construction
workers or the community during remediation. People wanted to know how the risk associated
with the increased truck traffic compares to the risk associated with leaving the contaminated soil
in place. They also asked what safety measures would be used during remediation to prevent
accidents and spills.
Comment: Michael Finn wrote that the thousands of heavily loaded trucks on the
highway may contribute more risk than leaving the soil in place. (028421)
Comment: Fred Maienschein wrote that the wildlife in EFPC is in more danger from
bulldozers during remediation and subsequent development after cleanup is completed (than from
the contamination). (028564)
Comment: Patty Dyer said she agreed with concerns that the traffic hazard is the
greatest risk of this project. (PM05)
Comment: Herman Weeren asked what methodology was used to weigh a traffic death
against cleaning the creek to protect wrens or worms. He asked how the decision was made to
protect wrens and worms instead of the public. Weeren said that his primary concern was with
the traffic hazard imposed by all of the enormous dump trucks barreling down the highway and
what happens to him if he happens to be in the way. (028563, PM04)
Comment: James Johnson asked for a satisfactory comparison of the risks of bulldozing
and trucking the soil versus the health risks of leaving it alone. He said that the 180 ppm number
is based on a maximum excess risk to an exposed individual of 1 x 10"4. (028675)
JT950328 2DH/SDD ' Ju,y 2J. 1995
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A commentor at the public meeting asked if the risk to the safety and health of the
construction workers from typical construction site activities has been calculated. Another
commentor asked if the risk to the public from traffic disruption had been calculated. (PM35,
. PM36, PM37)
Comment: Sidney P. duMont III wanted to know what safety measures are proposed
to protect the citizens and drivers of Oak Ridge from the increased dump truck traffic. He also
wanted to know if the dump trucks would be covered and escorted in small caravans. (028439)
Comment: Charles R. and Alma P. Schmitt said that excavation and trucking the soil
would represent a transportation hazard in itself. (028448)
Comment: Fred Harmon said that DOE should "draw parallels from the time that the
soil was moved from the Civic Center up on the hill." (PM18)
Comment: Elizabeth Peelle suggested using "low-tech" solutions instead of using
bulldozers and dump trucks. (PM21)
Comment: Sara Childs asked about the possibility of installing a signal light at the exit
and entrance of the excavation areas! (PM22) . .
Comment: H. Richard and B. Jane Hicks asked that the total negative effects be
balanced against the estimated real mercury hazard, which is not terribly serious because they and
a lot of other people have handled pure mercury and had no ill effects. (028345)
Response: A quantitative comparison of risks estimated to be incurred during
remediation (i.e., due to activities such as construction and additional traffic) and risks due to
leaving the mercury-contaminated soil in the floodplain is not possible.
The chances of injuries and fatalities during remediation were calculated based on U.S.
Department of Transportation statistics. Sections 5.3.1 through 5.3.7 (Short-Term
Effectiveness)in the feasibility study (DOE 1994b) contain brief discussions of community
protection and remediation worker protection (see "physical hazards" portion). In these sections,
for each of the seven alternatives (as presented in the proposed plan), the risk of transportation
accidents to these two groups is estimated. These estimates are listed in Table 2.1 in the
Decision Summary of this ROD. For Alternative 3, the feasibility study estimates that < 1 (
0.0018) worker injuries will occur and that < 1 (0.0018) worker will die a's a result of
JT950328.:DH/SDD • Ju!y 2g ,9,5
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transportation activities. It also estimates that < 1 (0.0515) people in the community will be
injured and that < 1 (0.0034 people) will die as a result of transportation activities. The
feasibility study further estimates that five injuries will be incurred by workers due to
construction activities and < 1 (0.038) worker will die as a result of construction activities.
In contrast, the chances of adverse health effects caused by leaving the mercury-
contaminated soil in place (i.e., by not remediating), a noncarcinogen, cannot be calculated. The
1 x \0~* maximum excess risk mentioned by one commentor applies only to carcinogenic
(cancer) risk. Below a specific dose, noncarcinogens do not induce any adverse health effects
in exposed populations. That specific dose is defined as the reference dose. Risk due to
exposure to noncarcinogens is quantified through the hazard index. The hazard index is simply
the ratio of the chronic daily intake of a chemical to that chemical's reference dose. A hazard
index greater than 1 would indicate that the chronic daily intake is greater than the reference
dose, but it in no way quantifies the probability of inducing an adverse health effect (LaGrega
et al. 1994).
The risks incurred during remediation can be qualitatively compared to the risks of
leaving the mercury-contaminated soil in the floodplain. This comparison is illustrated in Chapter
6 of the feasibility study (DOE 1994b) and in the proposed plan (DOE 1995b). The discussion
on "short-term effectiveness" corresponds to the risks incurred during remediation. The
discussion on "long-term effectiveness and permanence" corresponds to the benefits achieved by
remediating the mercury-contaminated soil as compared to the baseline risk assessment found in
the remedial investigation (EPA 1994a) and summarized in the feasibility study (EPA 1994b).
DOE's preference for Alternative 3 is based on a balance between short-term effectiveness and
long-term effectiveness. DOE believes that Alternative 3 provides the best balance between risks
incurred during remediation and risks incurred by leaving the mercury-contaminated soil in the
floodplain. DOE also believes that human health and the environment would be protected
adequately during implementation of the remedial alternative.
DOE appreciates the public's recommendations for reducing transportation and
construction hazards. Safety measures, generically referred to as "best management practices"
in the Decision Summary, will be used during implementation of any remedial action. Exact
measures will be specified during the remedial design phase. They may include such actions as
using alternative construction equipment (i.e., using "low-tech" solutions), constructing new
roads, installing temporary signal lights in high-traffic areas, covering the dump trucks, and
escorting the trucks in small caravans. DOE will also review the procedures followed when
JT950328 :DH'SDD July 28. I
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moving soil from the Civic Center to determine what lessons learned from that activity apply to
excavation and transportation of the soil in the Lower EFPC floodplain.
ISSUE 6: REMEDIATION IS TOO EXPENSIVE
Many people at the meeting criticized costs associated with implementation of Alternative
3 or the cost of the entire project of remediating the mercury contamination in the soils near
Lower EFPC. Others said that remediation levels for Alternative 3 are too low and that money
could be saved by raising them. Two commentors suggested that the money saved from raising
remediation levels could be well used on other remediation sites. Other commentors said that
the benefits of implementing Alternative 3 should be weighed against these deleterious effects.
Several said remediation is a waste of money. •
In general, these commentors said that the cost of implementing Alternative 3 outweighs
the benefits. Specific comments are listed here.
Comment: James Ed Westcott wrote that no remediation should take place at all along
EFPC: (028318)
Comment: Murray W. Rosenthal and Fred Sweeton said that spending too much on one
remediation project could effectively reduce the amount of money available for -other such
projects, thereby increasing the overall risk to the public and the environment. (028416, 028768)
Comment: Charles and Alma Schmitt wrote that they consider Alternative 3 a waste of
money and based their opinion on mercuric sulfide not being a health hazard. (028448)
Comment: William Fulkerson, Friends of ORNL, said that, because the remediation
goal should be four times higher than it is, implementation of Alternative 3 will waste an
enormous amount public funds. (028650)
Comment: Geoffrey Gleason wrote that the mercury contamination of EFPC is riot a
hazard and that to spend additional funds on it cannot be justified. (028673)
Comment: William J. Wilcox, Jr. wrote, "Can't you adequately protect us and our
environment by spending less money [by remediating to a higher level]?" (028744)
JT950328.2DH/SDD July 2g. 1995
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Comment: Elizabeth Busteed wrote that to spend millions of dollars for unnecessary
remediation cannot be justified. She added that too much money has already been spent.
(028834)
Comment: Fred Maienschein said he estimates the cost associated with "unnecessary
conservatism" is $50 million. (PM01).
Comment: Ellen Smith said that DOE could purchase the affected land at fair market
value and it would be much cheaper than Alternative 3. (PM03)
Comment: Fritz McDuffie asked, "Why will it cost $3,000/yd3 to move all the dirt?"
(PM09)
Comment: One of the cards anonymously submitted at the public meeting objected to
the massive expenditure of money on risk assessment with a confidence level of essentially zero.
(PM33)
Response: DOE realizes that the remediation of the Lower EFPC floodplain is very
expensive. However, the health, safety, quality control, and regulatory requirements for dealing
with contaminated substances (i.e., mercury-contaminated soil) make implementation of a
remedial action expensive compared to, for example, excavating a residential basement.
Several commentors said Alternative 3 was too expensive due to unnecessary
conservatism in the remediation goal. As discussed in the Decision Summary and in the response
to comments under the "Remediation goal is too low" issue, the remediation goal has been
increased, thereby substantially decreasing the cost of implementing Alternative 3.
Other commentors said that remediation of the Lower EFPC floodplain is not worth the
high cost. As discussed in the response to comments under the "Opposition to cleanup" issue,
remediation is required to protect human health and the environment.
The comparison of alternatives in the feasibility study (DOE 1994b) and in the proposed
plan (DOE 1995b) documents the balance between the benefits and costs of remediation for each
of the alternatives considered (including Alternative 7, which included DOE acquisition of real
estate rights). The site was prioritized and funds were made available for its cleanup when the
EPA and the state of Tennessee reviewed the FFA (DOE 1992) for the ORR. Any money saved
could be used for other DOE remedial action projects.
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ISSUE 7: CONCERN ABOUT OTHER CONTAMINANTS, CUMULATIVE EFFECTS,
AND CONTAMINATION IN OTHER AREAS
Several people asked if other contaminants, cumulative effects of contaminants, and
contamination in other areas were considered.
Comment: Sandra Reid said she was concerned that only mercury was being considered
and that "multiple other contaminants, including uranium, volatile organic compounds, arsenic,
and chlordane, and their combined hazardous effects on the environment and human health" be
considered. She also said that "pregnant women and their fetuses are the most vulnerable,
particularly to atmospheric mercury, radiation, heavy metals, and volatile organic compounds."
She asked, "Why was only mercuric sulfide/chloride considered?," and said that fruit and
vegetable pathways of exposure were not considered. She indicated that a study had shown tree
rings that contained 3,000 ppm mercury and uranium uptake was significant. She asked that the
significant amounts of material generated by the Y-12 Plant be considered. (028786)
Comment: Ralph Hutchison, OREPA, said, "The feasibility study does not adequately
address contaminants other than mercury. During Y-12's years of peak production, significant
amounts of other contaminants, including uranium, PCBs, other metals, and organic compounds
are known to have been released irito the air and water. Any attempt to address environmental
restoration must examine the presence and remediation requirements of each individual
contaminant and all contamination taken as a whole." He said that the feasibility study must
consider other contaminants and must consider cumulative impacts of the variety of contaminants.
Hutchison is concerned with synergistic effects of multiple contaminants found in EFPC.
(028835)
Comment: Herman Weeren recalled that the data from the Hines Creek area, intended
as the control area, indicated that it was the most toxic of the areas sampled. He asked about the
implications of this and if it needed to be remediated also. (PM26)
Comment: John Williams said he was concerned about a fire vaporizing the mercury
in the soil and thus exposing the public to air borne mercury. He also 'asked about the
relationship of mercury and uranium in the soil. (PM30)
Comment: An anonymous comment at the public meeting indicated concern with arsenic
and radioactive contamination and their bioavailability in plants (PM45). Another anonymous
commentor asked if multiple contaminants, synergism, and cumulative exposure had been
considered. (PM49)
IT950328.2DH/SDD ' ju|y 28. 1995
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Response: Several chemicals were evaluated and cumulative impacts were determined
for the Lower EFPC site. The baseline human health risk assessment used a tired or phased
approach. This three-tired approach is explained in some detail in the ROD. In tier one, a
screening-level assessment was performed on 182 chemicals, including metals, organics, and
radionuclides. The assessment took into consideration the various historical effluents from the
Y-12 Plant and was intended to be comprehensive for the Lower EFPC site. This concentration-
toxicity screening approach reduced the number of contaminants requiring evaluation as
"contaminants of potential concern."
During the initial screening of Lower EFPC soil contaminants, eight inorganic
compounds, pesticides and PCBs, some polycyclic aromatic hydrocarbons (PAHs), and uranium
were found to be elevated in soils. The toxicity of the contaminants of potential concern were
considered to be additive because of the lack of data on the toxicity of multiple contaminants.
Additional evaluation ruled out all of these contaminants except mercury. The pesticides,
PCBs, and PAHs observed in the Lower EFPC media did not substantially contribute to the
estimated risks to human health. Risks associated with exposure to radioactive uranium fell
within the EPA target range in all cases. Contaminants driving the elevated risk estimates in the
baseline human health risk assessment include the inorganic compounds Hg, As, Be, and Mn.
Because mercury was by far the major contributor to risk of these contaminants, it was retained
as the chemical of concern for human health. A similar screening process was used for biota,
also resulting in mercury as the primary contaminant of concern in soils.
In surface water and sediment, multiple contaminants were also analyzed. It was
recognized that contaminants in surface water that are currently coming from the Y-12 Plant are
best addressed at the plant and not as part of the Lower EFPC remediation. Mercury and PCBs
were the major elevated contaminants in sediment. Mercury concentrations in sediment are not
high enough to cause direct toxicity in sediment, and aquatic biota do not contain mercury levels
high enough to be associated with toxicity, so the only potential for harm to the environment is
through the aquatic food chain. The contribution of mercury from sediment to surface water
exposure was modeled (because releases from sediment could not be measured directly) and
appears to be at least two orders of magnitude below the observed concentrations. Therefore,
sediment mercury appears not to be a major contributor to mercury body burdens in aquatic
biota. Most of the PCB is found in sediments north of the Oak Ridge Turnpike and downstream
of the Tennessee Valley Authority substation at the intersection of Illinois Avenue and the
Turnpike, suggesting that the transformers at the substation, not the Y-12 Plant, were the most
;g 2DH.-SDD My 28 ,995
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likely source. Ongoing efforts at the Y-12 Plant are improving conditions in the upper reaches
of the creek.
Synergism was considered in the ecological risk evaluations. The principal toxic form
of mercury is methyl mercury, whose mode of action is different from metal salts, so other
metals could not interact with it. Several combinations of metals have been shown to interfere
with rather than potentiate each others' actions, so it was more conservative to consider the
inorganic compounds individually. None of the other potential contaminants of concern were
known to act synergistically.
Areas such as Hinds Creek, near Norris, and Mill Branch, well upstream of its
confluence with Lower EFPC, were investigated as reference areas. Findings indicate that any
type of environmental investigation is unnecessary.
In the ROD, DOE, EPA, and TDEC have committed to monitoring this OU.
ATSDR concluded in the EFPC health consultation (April 1993) that only mercury in
soil and PCBs and mercury in fish are at levels of public health concern. In addition, ATSDR
stated concentrations of contaminants in the shallow groundwater are a public health concern, but
the groundwater is not used for drinking water or other domestic purposes and does not pose a
threat to people who receive drinking water from the municipal water supply. ATSDR concluded
that other contaminants, including radionuclides found in the soil, sediment, surface water, and
fish, were not at levels of public health concern.
ISSUE 8: ALTERNATIVE 3 AND/OR IMMEDIATE ACTION ALTERNATIVES ARE
THE MOST ACCEPTABLE
Several people said that remedial action should begin and be completed as soon as
possible, at. least for the areas of highest contamination.
Comment: James Harless said, "There is no better time to remove this material from
EFPC" since "not much time need pass for parts or all of these expensive studies to be out of
date." He said he does not want a few critics to be able to block some significant real toxic
material removals that are aimed at making this as safe a community as current knowledge and
experience seems to support. He wrote, "We owe it to future Oak Ridge residents, current and
downstream residents, and to taxpayers in general, to take a cleanup action based on 180 ppm
mercury, or on a number reasonably close to this level. We did not spend all this time and
money to get all dressed up so we could be told we have no place to go." (028621)
JT9503:8.:DH/SDD ' July 28. 1995
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Comment: Landowners Wayne Clark and Melvin Sturm said they are concerned about
the financial losses they are suffering so long as they are not able to develop their properties.
(028732, 028766)
Comment: Amy Fitzgerald, ORR Local Oversight Committee, said she is concerned that
funding may not be available to complete the project if additional studies are conducted to raise
the remediation goal and remediation is not initiated according to the current schedule. (028769)
Comment: The Oak Ridge City Council "urges the DOE to commence and complete
remediation activities at the earliest possible opportunity." (028789)
Comment: Robert Peelle said, "We should follow roughly the plan DOE has prescribed,
the so-called Alternative 3, removing and replacing the contaminated soil." He said,
"Administrative controls like fences won't last, soil treatment seems very problematic, capping
seems very temporary in the course of generations because the creek will most likely. ..meander
in the floodplain." (PM07)
Response: Alternative 3, the alternative put forth in the proposed plan (DOE 1995b) and
presented at the public meeting, is the selected remedy. The remediation goal has been increased
to 400 ppm mercury, thereby changing the magnitude of some of the components of the
alternative, but not otherwise changing the alternative. Some studies are ongoing or planned, but
remediation will not be delayed as a result of those studies. Remediation must be initiated within
15 months of the approval of the ROD.
ISSUE 9: REMEDIATION SHOULD FOCUS ON THE AREAS OF HIGHEST
CONTAMINATION
Several commentors said that the areas of highest contamination ("hot spots") should be
removed. Some said that only these areas need to be excavated.
Comment: Ellen Smith said that the layers of "black goop" seem to have the highest
concentrations of mercury and that it would make sense to clean up the identifiable concentrated
deposits. (PM03). She also wrote, "It should be possible to selectively remove the visually
identifiable concentrated layers of contamination using excavation equipment (scrapers?) that
would enable stripping of discrete soil layers, in order to separate relatively clean soil layers from
those with significant contamination." (028767)
JT950328.2DH/SDD ju]y 2g ,995
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Comment: Ricky Williams suggested spot cleanup so that a smaller total volume of soil
is ultimately excavated. (PM17)
Comment: Elizabeth Peelle suggested a "tailored, low-tech way" of removing the "most
contaminated stuff' and keeping open the option of more detailed cleanup later. (PM21, PM41)
Comment: Ralph Hutchison, OREPA, recommended that DOE immediately remediate
"those few small areas which present significant mercury contamination (> 300 ppm)" and store
the soil until it can be treated or disposed of. (028835)
Comment: Mayor Edmund Nephew recommended targeting excavation efforts on the
selective removal of the visually identifiable soil layers that have been correlated with
significantly elevated contaminant concentrations. (028789)
Response: Soil at only two sites, the NOAA site and the Bruner's site, contain levels
of mercury above the remediation goal of 400 ppm. Excavation will occur only at those two
sites. . .
There is a dark-colored band of soil which often contains high concentrations of
mercury. However, there are soils with mercury concentrations above 400 ppm that are not
distinguishable by color.
Because of the heterogenous distribution of mercury in soil, both horizontally and
vertically, excavation of selected, narrow bands may not remove all of the mercury above the
selected cleanup level. Even if it were .possible to always isolate mercury contamination to a
discrete layer in the soil, there are real world problems of recognition and actual physical
removal. It "would be very difficult with .any type of equipment to get the separation desired at
a reasonable cost and in a reasonable time.
Using hand shovels would require a longer time to remove the areas of high mercury
contamination than using standard construction equipment because roots and trees must be
removed and a layer of clean soil often covers the contaminated soil to be excavated.
The mercury contours in the maps in the remedial investigation (DOE 1994a) and the
feasibility study (DOE 1994b) are estimates of the suspected location of mercury above a certain
level. The contours are based on finding mercury above a given concentration (during the Phase
Ib sampling of the remedial investigation) and interpolating that concentration based primarily on
JT950328.2DH/SDD Ju,y 28. ,995
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topography. Thus, during the actual remediation, confirmatory sampling will be conducted to
establish the exact location of the higher mercury concentrations and to confirm that all soil
contaminated with mercury above 400 ppm has been removed.
ISSUE 10: EROSION AND RECONTAMINATION
Comment: Sidney duMont asked if the differences between soil erosion impacts of
replacement of contaminated soil with borrow soil versus treatment of contaminated soil and
backfill with that original soil had been considered. He also asked about the impacts of erosion
of soils from the borrow area and from the landfill. (028439)
Comment: Linda Ewaid said that excavation and trucking of the soil may "make the
situation worse by stirring up and spreading the contamination and damaging the environment."
(028746)
Comment: Ardis Leichsenring said she was concerned that trees would be cut, "leaving
the land nude." (PM08)
Comment: A card anonymously submitted at the public meeting asked, "What is the
point of removing some of the contamination when the Y-12 Plant could still recontaminate the
creek?" (PM44)
Response: After remediation, each excavated site would be restored by grading the land
surface to. its original contour, stabilizing the site to prevent erosion, and revegetating the site to
ensure long-term stability of the soil surface [see page 5-63 of the feasibility study (DOE 1994b)].
A specific comparison between backfilling with borrow soil versus treatment of the contaminated
soil and backfill with that original soil was not considered. However, erosion effects of backfill
material and treated soil" were considered in the feasibility study (DOE 1994b).
Recontamination of the soils is not expected. The contamination of the floodplain soils
occurred during the 1950s and 1960s. The processes in use at that time have been discontinued
and the current residual releases of mercury from the Y-12 Plant are minimal and decreasing.
As pan of the remedial design, an Erosion Control Plan will be written. Following good
management practices during cleanup of upstream areas would prevent any appreciable
contamination from migrating downstream.
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Contamination of sediments by sloughing of stream-bank soil containing high levels of
mercury was also examined in the feasibility study (DOE 1994b). The predicted downstream
concentrations in the sediment are less than 100 ppm. This model result is consistent with
observed sediment concentrations, which have always been below 100 ppm.
ISSUE 11: LANDFILL AND ASSOCIATED OPERATING COSTS
A few comments had specific concerns related to the proposed landfill at the Y-12 Plant,
into which excavated contaminated soil would be deposited under Alternative 3.
Comment: Sidney duMont, in a written comment, asked about the erosion of soils from
the proposed landfill. He also asked if there was any chance DOE would later be forced to treat
the contaminated soil placed in the landfill because of the teachability of contaminants or other
performance issues. (028439)
Comment: Harry Francke and Ricky Williams asked, "What will the landfill look like?
How will it be handled? How will the mercury be contained in the landfill? What will the effect
on the groundwater be? What will the cost of ongoing care and monitoring of the landfill be for
the next hundred years? Mr. Williams said he did not see any cost estimates for ongoing care
of the landfill." (PM12, PM17)
Comment: Linda Ewald asked about disposal of the contaminated soil. If it is exposed
to rain or buried in the ground, she said she is concerned that the contamination will eventually
reach and contaminate the groundwater. (028746)
Response: The landfill, used for disposal of the mercury-contaminated soil will be a
lined, permitted, Subtitle D landfill with leachate collection. The liner will prevent any migration
of leachate to the groundwater. The leachate will be treated, if necessary, before it is discharged.
The landfill is estimated to be open for 5 years after the first load of soil from the Lower EFPC
floodplain is deposited. When full, the landfill will be capped with liners and a vegetative cover.
The level of material in the landfill will always be lower than the perimeter of the
landfill. Therefore, erosion of the mercury-contaminated soil in the landfill will not occur. The
liners and vegetative cover will inhibit erosion after the landfill is closed. .
The cost estimate presented in the feasibility study (DOE 1994b) reflects the cost of
operating the open landfill for 5 years. Thirty years of post-closure care are generally required
JT950328.:DH/SDD July 28. 1995
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for landfills. However, the cost for post-closure care is not included in the feasibility study cost
estimate for Alternative 3. DOE is evaluating whether costs associated with post-closure care are
applicable to this remedial action.
ISSUE 12: REASON FOR REMEDIATION
Comment: Shannon Gorman asked, "Why did DOE make the decision to remediate?"
She also asked, "What is the guiding factor and why did DOE decide that this cleanup action was
necessary?" (PM28)
Response: DOE performed a baseline risk assessment as part of the remedial
investigation of Lower EFPC. The results of this risk assessment indicated that an unacceptable
risk to human health and the environment would remain if no cleanup action is taken. The
CERCLA legislative process mandates that a cleanup action be taken if an unacceptable risk to
human health and the environment is posed. Therefore, DOE has no option except to reduce the
level of mercury contamination to acceptable risk-based levels.
ISSUE 13: ADVISORY SIGNS
The state of Tennessee has posted signs discouraging fishing and water contact along
Lower EFPC. Some members of the public wanted these advisory signs changed to only
discourage fish consumption.
Comment: Alfred Brooks, in a petition signed by 13 community members, requested
that EFPC be posted against fishing only in those regions for which the levels for mercury and
other toxins in fish exceed the guidelines for safe human consumption and that other restrictions
on creek water contact be removed. (028674, PM02)
Comment: Richard and Jane Hicks asked for a permanent solution, which they said
would allow the existing advisory signs to be removed. (028345)
Response: The advisory signs fall under the purview of the state of Tennessee. Upon
completion of cleanup, the state will reevaluate the need for the advisory signs.
/T9503:S 2DH/SDD juty 28. 1995
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ISSUE 14: DOE COMMITMENT TO DECREASE MERCURY LOSSES FROM Y-12
Several residents requested a commitment from DOE to further decrease discharges from
the Y-12 Plant.
Comment: Alfred Brooks and 13 members of the community signed a petition stating
that DOE should continue its commitment to the cleanup of the discharges from Lake Reality and
subsurface sources at Y-12. (028591,028674)
Comment: Robert W. Peelle requested that DOE include an explicit pledge to.
continually reduce pollution discharges from the Y-12 Plant. (028788, PM07)
Comment: Amy Fitzgerald, ORR Local Oversight Committee, said she would like DOE
to make a commitment including "an explicit pledge to continue to reduce discharges from the
Y-12 Plant." (028769)
Comment: Charles and Alma Schmitt said they think there is no adequate guarantee or
environmental pollution controls that would prevent the Y-12 Plant from recontaminating EFPC
with mercury, radioactive substances, or other toxic pollutants. (028448)
Response: DOE is committed to decreasing mercury losses from the Y-12 Plant, The
potential for substantive mercury releases from the Y-12 Plant is minimal in that neither
production activities nor processes that used mercury are operative now. The source of
contamination is outside of the confines of the Lower EFPC OU and are being addressed by the
Y-12 Plant ER Program as part of the Upper EFPC OU. Any small amounts of mercury leaving
the Y-12 Plant are the result of historic deposits of mercury within the plant boundaries. To
comply witrr the requirements of the Clean Water Act, DOE is negotiating a new National
Pollutant Discharge Elimination System permit, as required by Section 402 of the Clean Water
Act. The National Pollutant Discharge Elimination System permit is undergoing final negotiation
to establish effluent compliance goals, objectives, and a schedule for obtaining compliance with
State instream water quality standards. As a regulated process, failure to comply with the permit
requirements may result in stipulated fines and penalties. Further detailed information on the
status and progress of this Clean Water Act requirement may be obtained by contacting the
Information Resource Center.
JT950328.2DH/SDD _ ' July 28 1995
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ISSUE 15: NEED FOR CONFIRMATORY SAMPLING
Comment: Ardis Leichsenring asked if the contaminated areas would be checked again
to be sure thai they contain 180 ppm mercury before they are excavated. (PM08)
Response: DOE is currently sampling to further define the contours of the soil
contaminated with mercury above 400 ppm. In.addition, confirmatory sampling will be
conducted during remediation excavation to further delineate the soil above 400 ppm and to
confirm that excavation is complete.
ISSUE 16: DESIRE FOR UNRESTRICTED LAND USE AFTER REMEDIATION
Three written comments encouraged cleanup to levels that would provide for unrestricted
future land use.
Comment: Melvin Sturm, property owner, said that he would like to see his property
"returned to a safe condition so that [he can] be free of restrictions." (028732)
Comment: Wayne Clark, property owner, said he hopes EPA, TDEC, and DOE will
"adopt a remedy which will incorporate sufficient health-based performance criteria to protect
the public, the environment, and return [his] property to a safe condition and with no restrictions
on its use." (028766)
Comment: Finally, Mayor Edmund Nephew, on behalf of the Oak Ridge City Council,
wrote that "the city strongly embraces this goal [of unrestricted future land use] and believes it
to be a necessary outcome of any cleanup strategy." (028789)
Response: Implementation of Alternative 3 will allow for future unrestricted land use
for all land use types in the Lower EFPC floodplain.
ISSUE 17: COST SHOULD DETERMINE SELECTION OF THE REMEDY
Several people said that cost should determine the choice of alternative.
Comment: W. W Parkinson wrote that "simple economy should be the controlling
factor since all alternatives protect human health adequately." (028226)
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July 28. 1995
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Comment: Daniel Axelrod suggested developing alternatives on the basis of cost. For
example, he suggested an alternative that consists of remediating as much of the floodplain as
possible for $4.5 million or $10 million. (028748)
Response: Of the nine CERCLA criteria, two are threshold criteria, five are balancing
criteria, and two are modifying criteria. Only the two threshold criteria, "overall protection of
human health and the environment" and "compliance with ARARs," drive the selection of a
remedial alternative. In other words, those two criteria must be met to consider implementation
of a particular alternative. Cost is one of the balancing criteria and, at the remedy selection
stage, is only used to compare alternatives against one another.
Implementation of any of the evaluated alternatives would cost more than $10 million.
A partial expenditure could mean only partial remediation, which would extend the time period
to final remediation, or not allow for final remediation.
ISSUE 18: INTERAGENCY COOPERATION
Comment: John and Kathleen Shatter wrote that they are "greatly concerned that DOE
isn't in dialog with EPA...making sure that our money is not wasted." (028453)
Comment: Ray Hedrick, U.S. Army Corps of Engineers, Nashville District, said he
commended DOE for the outstanding interagency cooperation. (PM31).
Response: DOE has benefitted greatly from constant interagency communication
regarding technical and program management issues that serve as the focus of the dialogue among
EPA, the state, and.itself. In particular, EPA has served a valuable role by providing the
resources of their national laboratories to review and evaluate technical approaches and studies.
For example, before the use of the mercury chemical speciation data, DOE used EPA's standard
risk assessment guidance to determine a cleanup level protective of human health. One hundred
per cent adsorption of the mercury exposure was assumed, resulting in a human health cleanup
level of 50 ppm (mercury). However, after networking, DOE found that the use of the absorbed
dose concept had been employed recently at two CERCLA sites in EPA Region IX (California).
The modified risk assessment that resulted from the chemical speciation and absorption studies
was used in the feasibility study addendum and resulted in raising the proposed human health
cleanup level to 180 ppm. In response to public comments and more site-specific supportive
data, EPA has concurred that a cleanup level of'400 ppm will be protective of human health for
;TM0328.:DH/SDD ( July 28, 1995
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this site. The results of these technical interactions have saved over $130 million in remediation
costs at this writing.
ISSUE 19: PUBLIC INVOLVEMENT IN THE DECISION TO CHANGE
COMPREHENSIVE ENVIRONMENTAL RESPONSE, COMPENSATION, AND
LIABILITY ACT/NATIONAL ENVIRONMENTAL POLICY ACT INTEGRATION
Comment: Ellen Smith, Environmental Quality Advisory Board, said she is concerned
that since DOE policy changed with respect to writing a feasibility study incorporating National
Environmental Policy Act (NEPA) values instead of writing a feasibility study-environmental
impact statement, the public would no longer have the opportunity to comment on the feasibility
study. Ms. Smith said she would have appreciated notification of the opportunity to comment
on withdrawing the notice of intent to prepare an environmental impact statement for this project.
(028767)
Response: DOE advised the public of its revised NEPA policy in a mailing sent to more
than 1 ,500 stakeholders. In the mailing, DOE solicited public opinion on withdrawing the notice
of intent for NEPA. DOE did not receive any adverse comments on the proposed feasibility
study. Nonetheless, the feasibility study fully addresses all NEPA values.
In addition to the public being asked to comment on the proposal to change the approach
in dealing with NEPA, DOE followed a 45-day public comment period on the proposed plan,
which is consistent with a NEPA review period for a Draft Environmental Impact Statement,
rather than a 30-day period, which is consistent with CERCLA. DOE also indicated that
comments on the proposed plan and supporting documents (such as the feasibility study and the
remedial investigation) would be addressed in the Responsiveness Summary, so the public had
opportunity to comment on the full range of information available.
ISSUE 20: NATURAL RESOURCE DAMAGE ASSESSMENT APPLICABILITY
Comment: Vickie Brumback asked if the city of Oak Ridge could receive Natural
Resource Damage Assessment funds to be used for other purposes if a lower cost alternative were
selected. (PM24)
Response: The Natural Resources Damage Assessment process is performed after a
response action to assess residual damages. Residual damages are those injuries to natural
resources thai were not addressed by remedial actions. The damage assessment is the process
the trustees of natural resources (e.g., the U.S. Fish and Wild'iie Service) use to determine the
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amount of monetary damages a trustee may pursue in a CERCLA action as compensation for
injury to natural resources, or for the cost of mitigation, restoration, or replacement of lost or
injured natural resources. Therefore, any potential money would not go to the city of Oak Ridge.
ISSUE 21: FUTURE LIABILITY
Comment: Wayne Clark expressed a liability concern. He said that he owns 2,000
undeveloped linear feet of the Oak Ridge Turnpike and EFPC. He said that, if in the future he
seeks to develop his land and then he's taken to court by a person making a claim, DOE should
assume the legal responsibility and hold him harmless. Mr. Clark also asked who would be liable
if future requirements indicate that the present cleanup level is too high and further remediation
is required, (PM15)
Response: DOE assumed the role of Potentially Responsible Party pursuant to
CERCLA. Should DOE releases require further CERCLA cleanup, DOE, in concert with the
FFA panics, would undertake the remediation in accordance with CERCLA, NCP, and the FFA.
ISSUE 22: EFFECT OF A FIRE IN THE FLOODPLAJN
Comment: John Williams asked whether DOE, EPA, and the state of Tennessee
considered the scenario of a fire in the floodplain with potential volatilization of hydrogen sulfide
where concentrations of hydrogen [mercuric?] sulfide are less than 180 ppm (PM06).
Response: While soil temperatures become elevated during a fire, they do not exceed
200°C (390°F) 2.5 cm (1 in.) below the soil surface (Barbour et al. 1980). The change in soil
temperature is a function of the thermal conductivity of the soil and the temperature and duration
of the fire. The rate of heat transfer is affected most by the amount of soil moisture.
Temperatures will not rise above 100°C (212°F) until all water evaporates.
Treatability studies showed that the mercury species in the Lower EFPC floodplain soils
volatilize in the temperature range of 250-650°C (480-1,200°F) (DOE 1993), In addition, the
majority of the mercury in the Lower EFPC floodplain soil is buried under more than 2.5 cm
(1 in.) of soil, and the soils have a very high moisture content. For these reasons, volatilization
of mercury would be negligible, even during very intense fires such as forest fires or fires used
to clear land for development.
JT950328.2DH/SDD ,uly 2«. ,995
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ISSUE 23: PROCEDURE FOR CHANGING THE REMEDIATION GOAL
Comment: Bill Burch asked if it is possible to change the remediation goal (i.e., what
the procedure was to change it). (PM13)
Response: It is possible to change the remediation goal. In fact, this ROD reflects an
increase in the remediation goal. Alternative 3, as presented at the public meeting, was based
on a remediation goal of 180 ppm mercury. Through the risk management process, the
remediation goal has since been increased to 400 ppm based on less-conservative risk assumptions
and additional risk calculations. The remediation goal of 400 ppm is protective of human health
and the environment.
ISSUE 24: ECOLOGICAL CONCERNS
One commentor expressed support of the remediation plan despite short- to
intermediate-term loss of habitat. Several commentors said that the apparent ecological risks in
the EFPC floodplain are less than indicated by the feasibility study. They expressed concerns
that the remediation goal of 180 ppm is too low and that cleanup would do more damage to the
environment than it would benefit the resident plant and animal populations. On the other hand,
some commentors said that the remediation goal is not sufficiently protective of plants and
animals.
Three commentors criticized the content of the ecological risk assessment. Some
comments reflected an impression that the feasibility study deals with exposures to EFPC surface
water as well as floodplain soils and that DOE is responsible for evaluation and remediation of
non-DOE sources of contaminants.
Comment: Amy Fitzgerald, Local Oversight Committee, said she generally supports the
selected remedy. She said that wetlands compensation could help offset the loss of wetlands
caused by remediation and that habitat restoration will probably occur in the not-too-distant
future. (028768)
Comment: Ann and Douglas Macdonald said they do not want the Greenview area
remediated. They said that the birds and animals are plentiful and do not seem to suffer from
toxic effects. (028346)
July 28 1995
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Comment: A. D. Ryon said that the ecological remediation goal of 180 ppm is too
conservative and that habitat destruction resulting from remediation would be more damaging than
the existing exposures. He said that Florida has a mercury problem—not Oak Ridge. (028820)
Comment: James Ed Westcott said he is concerned that cleanup will destroy natural
habitats, which will require years to recover and that EFPC "may never return to its natural
state." (028318)
Comment: Geoffrey Gleason said that mercury levels in biological specimens do not
indicate significant exposure to mercury. He said that concentrations of mercury in canned tuna
(analyzed between 1983 and 1987) were higher than in any biological specimens from EFPC.
(028673) •'.'.-
Comment: James Phelps and Sandra Reid mentioned fish kills in EFPC. James Phelps
said he wants the problem of fish kills in EFPC to be explored and exposed publicly, as well as
interactions of mercury and radionuclides that cause damage to deoxyribonucleic .acid (DNA).
(028742)
Comment: Alfred Brooks.said that the ecological risk assessment for EFPC addresses
individuals rather than populations, does not address effects from non-DOE sources, does not
balance the cost of environmental cleanup against the value of a few individual animals, does not
demonstrate harmful effects to plant or animals populations, and does not demonstrate a need to
harm the environment by remediating it. (028347)
Comment: Ellen Smith wrote that the ecologically based remedial goal of 200 ppm is
too stringent. She said that the EFPC floodplain ecosystem appears to be healthy and diverse,
so the net effect of remediation, with its attendant habitat alteration, would be "extremely
negative." She wrote that it is questionable whether habitat restoration would be successful
because of the lack of habitat reservoirs in the urban setting of the floodplain. She said that the
remedial goal for protection of the environment should be greater than that for the protection of
human health; "that is, if a higher human health goal is selected, the ecological goal should also
increase to the same level or higher." (028767)
Comment: Fred Maienschein said of the ecological risk assessment, "the numbers and
the quoted remediation goal are neither understandable nor apparently consistent," and the
accompanying uncertainties make the remediation goal no better than an order-of-magnitude
estimate. He said wildlife is thriving now but will be threatened by cleanup. He also stated that
JT950328.2DH/SDD Ju|y 28, 1995
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the bioavailability factor of 100 percent used in ecological risk assessment is unrealistic in light
of low apparent bioavailability of mercury from floodplain soils. (028564)
Comment: Ralph Hutchison, OREPA, said that the feasibility study did not adequately
address contaminants other than mercury. He said that there are significant risks to plants and
animals from exposure to uranium, as documented by detectable levels of uranium in their bodies
and in soil, sediment, and water. He said there are risks to aquatic life from chlordane in the soil
and that the ecological risk assessment does not address cumulative or synergistic effects of
contaminants on plants and animals. He further stated that DOE has not demonstrated that the
distribution of forms of mercury in EFPC floodplain soils will not change in the future and has
ignored the potential of mercury to inhibit the repair of radiation damage in fish.
Hutchison said that toxic effects of EFPC contaminants to plants were ignored in the
ecological risk assessment, including the presence of mercury in tree cores, which he states was
documented to be above 3,000 ppm. He expressed a concern that toxic effects of contaminants
on contaminant-resistant plants were studied.
Hutchison further said that the impact of contamination on ecological health is either
underestimated or ignored. He believes that the ATSDR health consultation should not have been
restricted to evaluation of risks to humans. He said the uncertainties inherent in the ecological
risk assessment were "stunning." He does not believe that a decision on protection of the
environment can be made when the environment is a constant state of flux. He said that
comparing the relative risks of current exposures to the potential damage caused by remediation
is "outside the boundaries of recognized practice in considering environmental impacts," as
described by NEPA. Hutchison said that risk managers may not have the moral authority to
decide whether to remediate a site or leave its habitat intact. He said that balancing the remedial
risks to ecosystems against ecotoxicity requires further discussion before it is applied, and he
demanded that the ecological risk assessment be rewritten to include "recent data and cumulative
impacts or multiple contaminants and to discard the 'new method'" (i.e, balancing risks in the
feasibility study). (028835)
Response: The selected remedy is based primarily on protection of human health, so
choice of the remedy did not rely solely on a demonstration of harmful effects to plants and
animals. However, ecological risks were identified, and it is necessary that after remediation
there be no unacceptable residual risks to plant and animal populations.
1T9S032S 2DH SOD July 28. 1995
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Numerous ecological remediation goals for soil were published in the remedial
investigation addendum (DOE 1994c). Remedial goal.for four types of receptors under three
exposure conditions were systematically developed. Mid-level predators required the lowest
remediation goals for protection; for the lower exposure scenario, remedial goal ranged from 60
ppm to -4,200 ppm. The recommended remediation goal, 300 ppm, was based largely on site-
specific assumptions and data. A previously computed remedial goal of 200 ppm (DOE 1994a)
was selected in the feasibility study (DOE 1994b) because of its conservative exposure
assumptions.
Because there were many public comments critical of the methods and results of remedial
goal development, DOE has systematically reexamined the remediation goal development process
(DOE 1995a). Two technical approaches were taken to extend and/or reinterpret the ecological
remediation goals for soil. One was to protect populations instead of each individual organism;
the other was to reevaluate all of the parameters in the exposure equation.
The approach and strategy document for the ecological risk assessment on the ORR
(Suter et al. 1994).states that the lowest observed concentration for dietary exposure that causes
effects on avian reproduction is "the most important chronic test endpoint for ecological
assessment of terrestrial effects of pesticides arid arguably the most applicable" for waste sites
(Suter et al. 1994). This document also states that the appropriate level of ecological protection
of mid-level predators is the population rather than the individual. Thus, an acceptable degree
of threat or risk to population survival at Lower EFPC should be achieved as long as the dietary
exposure of individuals does not exceed the lowest observed adverse effect level (LOAEL) for
reproductive success.
The value used in the Rl addendum (DOE 1994c) as the toxicity endpoint for the diet
of birds was 0.2 ppm, a value based on an estimated no observed adverse effect level (NOAEL)
for reproductive'effects. The currently proposed LOAEL for reproduction by wrens, which is
based on the LOAEL for reproduction by finches (1 ppm), was adjusted for the higher metabolic
rate of wrens to a value of 0.33 ppm (DOE 1995a). A change in the dietary toxicity benchmark
for mid-level predators from 0.2 mg mercury/kg diet to 0.33 ppm raises the by a factor of 1.67
to 500 ppm.
i
The second approach, which is independent of the first, is a reevaliiation of the assumed
fraction of mercury in the diet of mid-level predators that is methylmercury. A very conservative
value was used in the RI addendum (DOE 1994c). Data from the EFPC RI were not used
because the only data available from animals were for crayfish, which are more aquatic than
JT95032S.:DH/SDD July 2g. ,995
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terrestrial and are likely to have a much higher methylmercury content than terrestrial organisms
fed upon by mid-level predators. Instead, the fraction of methylmercury in birds was used in the
remediation goal derivation (DOE 1994c). Because methylmercury bioaccumulates more in mid-
level predators than in their prey, the methylmercury fraction in birds is a conservative estimate
of methylmercury percentage in the diet of mid-level predators.
The remediation goal for mid-level predators recommended in the RI addendum (DOE
1994c) was based on the assumption that 4 percent of the dietary mercury consumed by mid-level
predators is methylmercury. The number was the highest geometric mean fraction reported on
a seasonal basis for sparrows at the Almaden, Spain mercury mining site (Hildebrand et al.
1980). The geometric mean fraction calculated from all data reported (DOE 1995a) was 2.5
percent. If the toxicity benchmark remains at 0.2 pprn, a dietary methylmercury fraction of 2.5
percent , which is still conservative, increases the remediation goal from 300 ppm to 480 ppm.
Therefore, either a change in the safety factor or a change in the percent methylmercury results
in a remediation goal of ~ 500 ppm. If both these changes are considered together, the
remediation goal could be as high as 800 ppm. It is DOE's position that the revised remediation
goal is conservatively protective for both human health and the environment.
Digging up contaminated soil will unquestionably alter some terrestrial habitats.
However, remediation must protect human health and the environment in the long term. The
proposed remediation will result in temporary destruction of small amounts of habitat that will
not permanently impact ecological populations. Because the revised plan calls for only a very
limited area to be excavated, a relatively small amount of habitat will be damaged. It will take
a few to several decades for the habitat, including wetlands, to recover completely. The choice
of the preferred alternative indicates that DOE, EPA, and TDEC consider the loss of habitat to
be justified by the resulting reduction of risk to humans, plants, and animals using those parts of
the floodplain. The proposed plan requires measures be taken to prevent damage to the creek
as a result of excavation of floodplain soils. The revised cleanup plan calls for excavation of only
a few limited areas in the floodplain, none of them adjacent to current residences.
Elevated levels of mercury were found in some biological specimens during the remedial
investigation. Many biological samples taken from EFPC had mercury concentrations above
1 ppm, the current level allowed by the Food and Drug Administration for fish sold for human
consumption (49 Federal Register 45663). The mercury problem in Oak Ridge is real, but it is
clearly smaller and better contained than the problem in Florida.
:s :DH/SDD ' Ju!y 28. 1995
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The problem with fish kills has been discussed publicly in several newspaper articles.
Fish kills in Lower EFPC have been caused by such things as gasoline spilled from an overturned
tanker truck and solvents spilled at one of the commercial establishments near the creek. No fish
kills in Lower EFPC have been attributed to DOE activities or to contaminants in the floodplain
soils. Fish kills have occurred in Upper EFPC as a result of Y-12 Plant activities, but better
chlorine-handling equipment installed at the Y-12 Plant has decreased their frequency. However,
toxicity in Upper EFPC is not the subject of the Lower EFPC project.
The Second Report on the Oak Ridge Y-12 Plant Biological Monitoring and Abatement
Program for East Fork Poplar Creek (Hinzman 1993) describes studies of DNA damage (strand
breaks) in fish from EFPC. The studies do not identify the cause of DNA damage because there
are many possible causes of damage. The report concludes that the observed amount of DNA
damage is higher in fish from EFPC, Beaver Creek, and Brushy Fork than in fish from the Hinds
Creek reference site. Some EFPC samples had more strand breaks and some had fewer strand
breaks than samples from Brushy Fork. The amount of DNA damage in EFPC fish generally
decreased during the study period from June 1987 to August 1988. The highest amount of DNA
damage was observed in fish sampled in the loop north of the Oak Ridge Turnpike, where
concentrations of PCBs and some PAHs are also elevated more than at most locations nearer the •
Y-12 Plant. It is likely that urban runoff and commercial spills, rather than DOE activities,
account for most of these elevated contaminant levels.
Impacts of non-DOE sources on biological populations were discussed in the ecological
risk assessment. Effects on plant and animal populations were attributed to specific habitats,
nonspecific cyclical effects on populations, and former grazing. Pesticides, PAHs, and PCBs
may come from non-DOE sources, but their harmful effects are not so large as to negate the
benefits to human health of cleaning up contamination for which DOE is responsible.
A special task force studied ways to balance the risks and benefits of remediation against
the risks and benefits of exposure to contaminants: This task force concluded that an existing
threat to human health justifies the damage to ecosystems that would accompany remediation,
unless those ecosystems are protected by law (e.g., wetlands or critical habitat for threatened or
endangered species). Risks from remediation were discussed in the feasibility study, and
alternatives that caused the highest risks during remediation were among those eliminated from
consideration. An attempt was made in Alternative 7, more than in any other alternative, to
balance the value of ecological resources against the costs and benefits of remediation. DOE,
EPA, and TDEC concluded that the value of a permanent remedy was higher than the value of
preventing a temporary loss of a few animals or of habitat.
JT9503J8.:DH/SDD july 28. ,995
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Incremental changes in the ecological risk assessment resulted from the evolution of the
risk assessment process during the study. Remediation goals presented to the public and
described in supplemental documents [Addendum to the East Fork Poplar Creek—Sewer Line
Beltway Remedial Investigation Report (DOE 1994c) and Remedial Goal Options for Mercury in
Sediment of East Fork Poplar Creek, Oak Ridge, Tennessee (DOE 1995a)] were developed with
data that became available after the remedial investigation was completed. The wide range of
remedial goal presented in these supplemental documents reflects the broad uncertainties in the
available data, including limited site-specific data and published exposure data. It is the
responsibility of the regulators to choose what level of uncertainty fits with their policies for risk
management. Therefore, a conservative remediation goal for ecological risk was chosen.
The risks from contaminants other than mercury to plants and animals were addressed
in the ecological risk assessment. During the initial screening of EFPC soil contaminants, eight
inorganics, pesticides and PCBs, some PAHs, and uranium were found to be elevated. The
plants and animals that were sampled were analyzed to determine their whole-body burdens of
those analytes. When the amounts of available tissue were limited, the analyses were done in the
order presented above. The remedial investigation report presented the results of these analyses
in the tissue samples as representative of the exposure of biota to the contaminants. Most of the
analytes were excluded from further consideration at most sites because they were not above
background levels. Mercury and cadmium, pesticides, PCBs, and PAHs were retained because
their levels were elevated above background in at least one site.
Risk characterizations were done using available information about the concentrations
and toxicity of the contaminants of potential concern. Mercury was retained as a contaminant
of concern, but cadmium levels in soil appeared to be inadequate to cause chronic toxicity to
plants or wildlife. Although detectable levels of pesticides were found in some animals,
pesticides were not widespread in the biota, nor could it be shown that they originated from the
Y-12 Plant. EPA has set no cut-off level for cancer rates in biota, so protection of populations
from toxicity is the most suitable endpoint for PAH, PCB, and uranium exposure. The
concentrations of carcinogens required for direct toxicity are much higher than those that elicit
tumors, so higher concentrations of PAHs, PCBs, and uranium are tolerable for protection of
animals than for humans. Therefore, cadmium, pesticides, PAHs, PCBs, and uranium were
dropped and mercury was retained as the single contaminant of concern for the terrestrial
ecosystem.
In surface water and sediment multiple contaminants were also analyzed. It was
recognized that contaminants in surface water that appear to be currently coming from the Y-12
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Plant can not be cleaned up as part of the EFPC remediation. Mercury and PCBs were the major
elevated contaminants in sediment. Mercury concentrations in sediment are not high enough to
cause direct toxicity in sediment, and aquatic biota do not contain mercury levels high enough
to be associated with direct toxicity, so the only potential for harm to the environment is through
the aquatic food chain. The contribution of mercury from sediment to surface water exposure
was modeled (because releases from sediment could not be measured directly) and appear to be
at least two orders of magnitude below the observed concentrations. Therefore, sediment
mercury appears not to be a major contributor to mercury body burdens in aquatic biota. Most
of the PCBs are found in sediments north of the Oak Ridge Turnpike and downstream of the
transformer station at the intersection of Illinois Avenue and the Turnpike, indicating that those
transformers, not the Y-12 Plant were the most likely source. Ongoing efforts at the Y-12 Plant
are improving conditions in the upper reaches of the creek, but further changes in operations are
necessary and are being planned to reduce exposures in surface water even more.
Synergism was considered in the risk evaluations. The principal toxic form of mercury
is methyl mercury, whose mode of action is different from metal salts, so other metals could not
interact with it. Several combinations of metals have been shown to interfere with rather than
potentiate each others' actions, so it was more conservative to consider the inorganics
individually. The concentrations of gamma-emitting radionuclides, which cause DNA strand
breaks, were not sufficiently high in EFPC soils that inhibition of the repair of radiation-induced
DNA strand breaks by mercury would be a problem.
Mercury has been found in trees in the EFPC floodplain. Ralph Turner of ORNL has
found concentrations as high as 3 ppm (3,000 ppb, not 3,000 ppm) in trees. He states that the
location of the maximum concentrations in the cores corresponds to exposures by air or surface
water in the 1950s and 1960s, with much lower concentrations in recent growth rings. Only two
samples of leafy vegetation and shrub shoots, which reflect current exposures from soil and
surface water, were found to have mercury concentrations above 1 ppm. No trees sampled
during the EFPC remedial investigation showed mercury concentrations above 1 ppm [Addendum
to the East Fork Poplar Creek—Sewer Line Beltway Remedial Investigation Report (DOE 1994c)].
Surveys of plant populations showed the same kinds of plant species in contaminated and
noncontaminated areas of the floodplain. The presence of mercury in healthy trees implies that
normal populations of trees have not been selected against by the toxic effects of mercury or
other contaminants. It is not harmful to the environment if individual plants are resistant to
contaminants, as long as ecosystem function is maintained.
JT9503:8.2DH,'SDD ' ju|y 28. 1995
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All of the requirements of EPA and TDEC were followed in preparing the ecological
risk assessment for EFPC. These included problem formulation, analysis (exposure assessment
and effects assessment), and risk characterization. Methods for an ecological risk assessment are
not as well defined by EPA as methods for a human health assessment. Therefore, the
site-specific approach and methods to be used for the EFPC environmental risk assessment were
discussed with and approved by EPA and TDEC before the work began. ATSDR did not advise
DOE on methods or toxicity values for ecological risk assessment because ecological effects are
beyond that agency's scope.
At many points during the process, meetings and teleconferences were held with EPA
and TDEC to ensure that the risk assessment was being performed in accordance with general
and site-specific EPA guidance. The result was a document of over 500 pages that was more
detailed in its analyses than most published ecological risk assessments to date. It also included
a more detailed analysis of uncertainties than most ecological risk assessments. The document
was reviewed and approved by regional and national offices of DOE and EPA and by TDEC.
Progress reports and conclusions were presented to the public on several occasions. The remedial
investigation report, including the ecological risk assessment, was accepted by EPA and TDEC.
DOE, EPA, and TDEC are required by CERCLA to make decisions concerning risks
to the environment and the best forms of risk management to deal with those risks. Weighing
the risks of remedial activities against the risks from current exposures is necessary under
CERCLA and is not forbidden by NEPA, so it was done as a part of the feasibility study. The
approach to balancing risks, in which human health risks and risks to the environment were
considered, was developed by a task force that included representatives from ATSDR,
Environmental Quality Advisory Board, ORNL, and Science Applications International
Corporation. The use of that method was approvd by EPA and TDEC and has received general
support from the public.
ISSUE 25: WETLANDS
Comment: Edmund Nephew, mayor of the city of Oak Ridge, stated that the damage
to wetland and riparian habitats accompanying remediation may be more damaging to the
environment than the current exposures. He also expressed a concern that there is insufficient
information on how wetlands disturbed by remedial activities would be restored, replaced, or
compensated. He stated that preservation of wetlands is preferable to mitigation. (028789)
JT950328 2DH/SDD )u|y28. 1995
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Response: The delineated wetlands at the NOAA site are no longer slated for
excavation. Only 0.24 ha (0.6 acres) of the "low-quality" wetlands at the Bruner's Center site
have mercury concentrations > 400 ppm. That portion of wetlands will be remediated and
restored. No wetlands will be removed and compensated for on DOE property. The amount of
riparian.habitat to be disturbed is small.
ISSUE 26: ECOLOGICAL BIOAVAILABILITY TOO CONSERVATIVE
Comment: Fred Maienschein said that the assumption of 100 percent bioavailability was
a fundamental flaw in the risk assessment. (PM38, PM40)
This point was reiterated by Alfred Brooks. (PM42)
Response: Exposure estimates in the ecological risk assessment were not based on the
bioavailability information used to revise the human health remediation goal. Instead,
bioaccumulation factors derived from site-specific data or from published information were used
to estimate bioavailability of total mercury to plants and animals. It was assumed that 100
percent of methyl mercury in ingested food is bioavailable. That assumption is prudent because
methyl mercury, unlike particle-bound or insoluble inorganic mercury species, is readily absorbed
after it is ingested. .
ISSUE 27: MERCURY SPECIATION
Comment: Ralph Hutchison, OREPA said, "Re-speciation by biota is noted but not fully
explored in the ecological risk assessment. He said that DOE has not adequately explained the
cyclical nature of mercury speciation in an anaerobic system in the presence of bacteria. He also
said that EPA's Environmental Monitoring Systems Lab was unable to provide conclusive
evidence that a high percentage of the mercury in the EFPC floodplain is in the form of mercury
sulfide. (028835) -
Comment: Sandra Reid asked about future projections of the mercuric sulfide in an
anaerobic environment. (028786)
Comment: A card anonymously submitted at the public meeting asked how elemental
mercury became mercuric sulfide and how many studies were conducted. (PM46)
JT950328.2DH/SDD , july jg. 1995
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Response: Mercury in Lower EFPC, as in all environments, is subject to
transformations as a result of changing biogeochemical conditions. The biogeochemical cycle of
mercury is tremendously complex. Since the 1970s, a voluminous amount of literature has been
produced on many aspects of mercury biogeochemistry. Despite this effort, many fundamental
questions still remain, and will remain unanswered for the foreseeable future. The lack of a
fundamental understanding of many processes governing the behavior of mercury in the
environment is not limited to Lower EFPC. Thus, it is not a reflection of a lack of scientific
effort, but rather an indicator of the complexity and magnitude of the problem and the pace of
science. Because some fundamental questions will remain independently, and because the
environment in the floodplain will always be dynamic, the biogeochemistry of mercury in the
Lower EFPC floodplain will never be understood unequivocally. To make a decision within the
FFA milestones, we must rely on our current understanding of mercury in the Lower EFPC,
based on DOE-sponsored investigations and on data available in the scientific literature, while
maintaining awareness about subjects where knowledge is limited. The evidence must be
weighted and criticality evaluated, as the speciation of mercury in Lower EFPC soils illustrates.
Revis et al. (1989a), using a sequential extraction technique he developed (Revis et al.,
1989b), determined that mercury in several soils in the floodplain were approximately 85 percent
mercuric sulfide. Subsequently, EPA EMSL, using a sequential extraction procedure they
developed (Miller 1993), determined the mercury in a different set of soils from the floodplain
was predominantly elemental mercury (Dobb et al. 1994), though significant mercuric sulfide was
detected in deeper, more concentrated samples. To resolve this discrepancy, ORNL-ESC
compared the results of the Revis and EMSL sequential extraction procedures, as well as a third
procedure (Sakamoto et al. 1992), on the same set of five soils. The results indicated the mean
percentage of mercuric sulfide detected by the three procedures was 46 percent, 25 percent, and
83 percent, respectively (Barnett et al. in press). The biggest difference between the results for
the Revis and EMSL procedures was in the abundance of elemental mercury, an average of 28
percent and 72 percent, respectively. Researchers from ORNL traveled to EMSL to discuss these
issues, but no final resolution was reached. ORNL-ESD has several theories as to the causes,
mostly related to the nature of sequential extraction methods and the procedures used for their
development. Although sequential methods are common methods for speciating metals in soils
and sediments (Tessier et al. 1979), these results illustrate the problems of using sequential
extraction procedures for quantitative analysis and are common concerns with sequential
extraction procedures (Pickering 1981). All three techniques did indicate, however, the mercury
in Lower EFPC soils was not organic, was not water soluble, and was resistant to extraction
except by aggressive means.
JT95032S 2DH/SDD ,„,,, 2S )995
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Other evidence implicated the presence of mercuric sulfide in Lower EFPC soils. A
consistent association between elemental mercury and elemental sulfur was shown in a number
of soils (K-25 Technical Division 1993). Total mercury correlated with total sulfur in the deeper
samples from the floodplain (Barnett and Turner. 1995). In addition, sub-micron crystals of
mercuric sulfide (metacinnabar) were definitively identified in some soil fractions (DOE 1994c).
Although the evidence is not conclusive quantitatively, the weight of the evidence suggests there
is mercuric sulfide in Lower EFPC soils. There is a clear association between mercury and
sulfur in a larger number of soils and mercuric sulfide was detected in all three sequential
extraction procedures applied to Lower EFPC soils, though the relative fractions were variable.
We do not definitely know the percentage of mercuric sulfide throughout the floodplain, nor is
the technology to determine this information available. In addition, as the mercury was not
discharged to the Y-12 Plant as a sulfide, it must have formed in situ, which is geochemically
intuitive and has been suggested in the scientific literature for years. This mercuric sulfide could
not have come from coal-fired steam plant emissions, as the majority of mercury in smoke stacks
is elemental, and there is no increase in mercury concentrations in noncontaminated soils in Oak
Ridge nor in other locations adjacent to coal-fired steam plants.
The potential for inter-species transformation of mercury in the floodplain is not known
precisely. This lack of knowledge is not just reflective of Lower EFPC, but of the global
mercury cycle as a whole. Of particular importance to the Lower EFPC is the transformation
from relatively innocuous mercuric sulfide to other more detrimental forms. While we do not
completely understand the cycles or all the issues involved, the available data suggest mercuric
sulfide is resistant to transformation. Over 1,000 times as much methylmercury formed in
sediments dosed with mercuric chloride (basis for RfD) as compared to mercuric sulfide
(Fagerstrom and Jernelov 1971). The mobilization of mercuric chloride from sediments to fish
in aquariums was more rapid than the mobilization of mercuric sulfide (Gillespie and Scott 1971).
The volatility of mercury from soils decreases with solubility, and is very low for mercuric
sulfide (Rogers 1979). Mercuric sulfide (cinnabar) applied to soils even in high concentrations
did not fail the TCLP test (Willet et al. 1992). Engler and Patrick (1975) studied the
transformation of mercuric sulfide dosed soils, and detected little transformation in either aerobic
or anaerobic conditions. Mercuric sulfide (cinnabar) was resistant to weathering in a riverwash
soil (Harsh and Doner 1981). Metal sulfide oxidizing bacteria were not observed to oxidize
mercuric sulfide (cinnabar) (Silver and Torma 1974).
While the methylation of mercury by microorganisms in anaerobic waters has been
noted, the production of anaerobic conditions by sulfate-reducing bacteria should actually promote
the formation of mercuric sulfide. Revis (1989a) shows an approximately 90 percent conversion
;T9S0328.:DH/SDD July. 28. 1995
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of mercuric chloride to mercuric sulfide in anaerobic soils by anaerobic organisms within 30
days. One unknown piece of information, until recently, was the weathering rate of mercuric
sulfide by oxidants common in the environment. Recent research at ORNL-ESD has shown the
oxidation rate of mercuric sulfide to be slow, with half-lives (t1/2) on the order of 20-200 years
depending on the conditions. If the weathering rate is slow (t1/2 of tens to hundreds of years)
relative to the rates of formation (t1/2 of days to months) as is suggested, mercury may be
effectively immobilized for long periods as mercuric sulfide. Indeed the current speciation in the
Lower EFPC fioodplain is the result of 30-40 years of such transformations. Research on this
subject is ongoing.
Finally, the ecological and human health remediation goals are not based on the
speciation results per se. There is not an accepted RfD for mercuric sulfide, and the mercury
in the Lower EFPC soils is not 100 percent mercuric sulfide. The human health remediation goal
was based on a bioavailability study (Barnett and Turner 1995) designed to measure the fraction
of mercury in soil available for absorption in the human digestive tract due to soil ingestion, the
critical pathway for human exposure in this system. This study, adopted from an EPA-approved
protocol at another CERCLA site, measured site- and soil-specific bioavailability without regards
to speciation. The bioavailability of mercury in Lower EFPC soil, regardless of form, was
shown to be orders of magnitude less than mercuric chloride, the basis for the RfD. Similarly,
the ecological risk assessment did not involve assumptions about mercury speciation. The
mercury speciation studies provided insight into the behavior of mercury in Lower EFPC soils
(i.e., the low solubility and bioavailability), but did not explicitly influence the remedial goal
calculations. These issues are discussed in more detail in the Addendum to the remedial
investigation (DOE 1994c).
ISSUE 28: SUGGESTIONS FOR THE SELECTED REMEDY
. Some people suggested technologies or ideas that might be considered.
Comment: Fred Harmon challenged the audience to develop their own alternative
because few members, seemed to support the DOE preferred alternative. (PM18)
Comment: Ralph Hutchison, OREPA, suggested that DOE limit access and maintain
strict environmental controls on EFPC pending any further action and that DOE purchase, at fair
market value, lands in the EFPC fioodplain to limit access, restrict development, and guarantee
cleanup. He suggested that lands could be sold back to owners at fair market value if
remediation efforts are successful. (028835)
/T9503:8.:DH/SDD
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Comment: Ellen Smith, Environmental Quality Advisory Board, suggested that DOE
offer to buy the affected land at a fair market value or to purchase deed restrictions that would
prohibit certain uses on affected portions of the land. Following remedial action, the land could
be transferred to the city of Oak Ridge or the state of Tennessee for floodplain protection and
other compatible public uses. (028767)
Comment: Fred Sweeton said he thinks each landowner affected by the remediation
effort "should be paid an amount equivalent to a reasonable rent up to the present time, and in
addition each should be offered a payment to compensate for both the real and the perceived
impairment of their land for future use." (028768)
Comment: Robin Williams suggested mixing the topsoil to a depth of about 6 in. using
a disk harrow for areas that have surface contamination slightly higher than acceptable levels.
He suggested burying the topsoil under 18 in. of subsoil for those areas where this will not
adequately reduce the level of contamination. (028747)
Comment: Daniel Axelrod recommended four additional alternatives: (1) delay action
for 10 years, then reassess; (2) divert headwaters of EFPC to the headwaters of Bear Creek,
(3) doing the maximum amount of remediation possible for $4.5 million; and (4) doing the
maximum amount of remediation possible for $10 million. (028748)
Comment: Charles and Alma Schmitt said DOE should consider installing emergency
cleanup treatment measures at Y-12 (holding pond, bags of Imbiber Beads for PCBs and oils, ion
exchange resins, and activated carbon granules) to adsorb pollutants before they reach the city
of Oak Ridge. (028448)
Comment: J. Francis suggested installing some sluice boxes to collect any mercury
migrating downstream and allowing the stream to clean itself. (028759)
Comment: Sara Childs asked, "How will the public be informed if the preferred
alternative is changed." She also asked, "Where are the areas of highest bioavailability?"
(PM29, PM47)
Comment: Ardis Leichsenring wrote, "We can see no reason for having all the areas
of the EFPC floodplain treated in the same way. The contamination levels are different and
future uses vary considerably." (028258)
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Comment: Alfred Brooks reiterated what Leichsenring said. (PM32)
Response: DOE appreciates the suggestions offered through written comments and at
the public meeting. Some suggestions are detailed enough that they would not affect the outcome
of the remedy selection process. Those suggestions will be taken into consideration during the
detailed design phase of the remedial action.
DOE has determined that the purchase of private properties in the Lower EFPC
floodplain would not provide the degree of protectiveness achievable through excavation and
disposal of the soil contaminated with > 400 ppm mercury, may be difficult to implement, and
would be an unnecessary expenditure of public funds. Excavation and disposal has been chosen
in favor of long-term institutional controls (e.g., access restrictions and deed restrictions) to avoid
requiring DOE to maintain long-term control of personal property and to provide for a permanent
remediation.
Mixing contaminated topsoil to a depth of 6 in. would essentially dilute the concentration
of mercury in the floodplain soil. While this would decrease the maximum concentrations of
mercury in the soil, it would not decrease the amount of total mercury in the floodplain, and it
may increase the volume of contaminated soil. Burying the topsoil under 18 in. of subsoil
essentially constitutes a cap. Capping is generically referred to as containment in the proposed
plan and was considered as a component of Alternatives 2, 4, and 6. The excavation and disposal
alternative rated higher than containment alternatives in the evaluation of alternatives because it
provides better long-term effectiveness and permanence.
Delaying action for 10 years would potentially nullify the current characterization of the
floodplain soils. Reassessing the site in 10 years could require duplicating the remedial
investigation efforts already conducted, resulting in an unnecessary expenditure of public funds.
Diverting the headwaters of EFPC to Bear Creek would decrease the volume of water
flowing through the Lower EFPC floodplain, but it would not decrease the amount of mercury
now present in the floodplain soil.
The lowest-cost alternative evaluated, the no action alternative, is estimated to cost $12
million dollars. Therefore, none of the remedial alternatives evaluated in the FS would be
possible for $4.5 million or S10 million.
JT950328.2DH/SDD July 28 1995
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The amount of mercury discharged from Y-12 into Lower EFPC is already very low and
is continually decreasing. Installing emergency cleanup treatment measures at the Y-12 Plant
would not affect the amount of mercury currently present in the Lower EFPC floodplain soil.
Sluice boxes would not be effective in collecting mercury suspended in the surface water.
Other methods of capturing the mercury may be considered during remedial design.
Public information meetings are held to inform the public of changes in the preferred
alternative. A public information meeting was held June 8, 1995. At the meeting, DOE presented
the most current information about the site and the selected remedy, including an increase in the
remediation goal from 180 ppm to 400 ppm.
Current land uses in the floodplain vary considerably. However, one goal of the Lower
EFPC soil remediation is to allow for future unrestricted land use. The most conservative land
use is the residential land use scenario. To allow for all types of future land use, all areas of the
Lower EFPC floodplain will be treated in the same way (i.e., all areas of the floodplain soil with
mercury concentrations > 400 ppm will be excavated). The area of higher bioavailability is near
the Y-12 Plant at the NOAA site.
ISSUE 29: ATSDR HEALTH CONSULTATION
Comment: Amy Fitzgerald, ORR Local Oversight Committee, said that without
additional information, the ATSDR may not be able to "sign off" on a significantly higher
cleanup level. (028769)
Comment: Max Howie, Jr., ATSDR, submitted a draft report stating that the proposed
remediation goal of 180 .ppm mercury was protective of human health. (028592)
Comment: The Oak Ridge City Council and Environmental Quality Advisory Board
requested that the ATSDR conduct another independent evaluation if the remediation goal is
increased. (028789, 028767)
Comment: A 'card submitted anonymously at the public meeting asked what kind of
health evaluation was done to show the remediation goal of 180 ppm was safe. (PM48)
Comment: Alfred Brooks asked if ATSDR could comment if a remediation goal is
"overly safe." (PM50)
JT950328.2DH/SDD
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Response: At the request of private citizens, ATSDR has conducted two health
consultations. The first consultation evaluated public health issues related to the current
contamination in EFPC. ATSDR concluded that soil mercury levels in some locations along
EFPC pose a threat to public health, especially to children who play in the creek's floodplain.
In addition, ATSDR stated contaminants in the shallow groundwater are of public health concern,
but the groundwater is not used for drinking water or other domestic purposes and does not pose
a threat to people who receive drinking water from the municipal water supply. ATSDR also
concluded that frequent ingestion of fish from the creek over a prolonged period poses a moderate
increased risk of adverse health effects.
The second consultation evaluated DOE's remediation goal of 180 ppm mercury in the
EFPC floodplain soil. ATSDR concluded the remediation goal was protective of public health.
Based on comments made during the EFPC public meeting, ATSDR initiated an addendum to the
consultation to evaluate the new remediation goal of 400 ppm. ATSDR has determined that the
400 ppm mercury remediation goal for the EFPC floodplain soil to be protective of public health.
ATSDR does not determine if a remediation goal is "overly safe."
ISSUE 30: PROJECT COSTS
Some people questioned specific project costs.
Comment: Fritz McDuffie asked how much money had been spent by all of the parties
concerned on this project without any remediation being done yet. (PM09)
Comment: Sara Childs asked if money is already set aside for this project. If not, she
asked how DOE budget cuts would affect this project. (PM11)
Response: As of January 1995, DOE has spent $24.7 million on the Lower EFPC
CERCLA project.
DOE conducts a prioritization of all projects based on risk to human health and the
environment. Because DOE-operations-related contamination has migrated off of the controlled
area of the ORR, this program will continue to rate very high in remediation activities.
JT950328 2DH/SDD ,uly 2g 1W5
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ISSUE 31: PROPER INVESTIGATIVE PROCESS NOT FOLLOWED
Several people questioned the procedures followed during the remedial investigation and
the risk assessment.
Comment: James Phelps wrote, "The proper process for doing this study is to map all
the pollution as it sits currently, via environmental sampling. Next, to fully determine the
specification [sic] of the many representative areas of the.mercury pollution and also to consider
if other forms of pollution are present. Next, to look at all known emissions to the Creek and
Floodplain to determine the equations in time for how the pollution deposits are changing in time
and spatial redistribution. Finally, to clearly present all known information accurately and farely
[sic] to the public which is clearly involved and has the right to the foil information set. To my
knowledge DOE has only reached step number one above." (028742)
Comment: Sandra Reid wrote that "good science" was not employed and that the
analysis is not accurate and "does not deal with the complexity of human beings and their varied
responses to toxic assaults." (028786)
Comment: Elizabeth Peelle asked if the risk assessment procedure described by Mr.
Zafran of Science Applications International Corporation was the standard practice for conducting
risk assessments. (PM27) .
Response: Since the ORR was formally placed on the National Priorities List of
CERCLA in December 1989, DOE has followed CERCLA guidance. In addition DOE has
complied with the provisions of the FFA in all aspects of the Lower EFPC project. In particular,
during the remedial investigation and baseline risk assessment for Lower EFPC, DOE obtained
regulatory approval of the technical approach to be used in collecting data for the project and
advice and assistance from an EPA national laboratory.
DOE conducted all four steps outlined in Mr. Phelps' comment. A two-phased approach
was followed in the remedial investigation stage. DOE identified and tested for 182 potential
contaminants and performed a screening level risk assessment on the results. After it was
determined that mercury was the primary contaminant of concern, the extent of this and some
other metals were determined by a systematic sampling of the entire floodplain of the creek,
involving over 3,000 samples. Since mercury proved to be the contaminant contributing by far
the greatest potential risk, and because the human health risk assessment process DOE was
required to use is especially sensitive to the species or form of mercury, special studies were
pursued to determine the various species of mercury in floodplain soils.
JT950J28.:DH/SDD ' Ju)y 2g ,995
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During these investigations it was shown that areas identified in the early 1980s as high
in mercury are still high and areas that are low were still low suggesting that the mercury has
some stability in the floodplain. Also, it was shown that many areas having higher mercury
concentrations were buried under soils deposited since the mercury releases in the late 1950s and
early 1960s. Studies were also performed which showed that sloughing of creek banks
containing high mercury concentrations could be accurately modelled (model results matched field
measurements).
DOE has made the information on this and other environmental restoration projects
available to the public as soon as possible and has specifically staffed an Information Resource
Center where the public can easily obtain this information free of charge. Further discussion of
community outreach is contained in the response to comments for Issue 39 (Citizen's Working
Group) and in the Decision Summary of the ROD.
The human health risk assessment process follows the standard EPA protocols for this
work. For the Lower EFPC project, extra care was taken to identify the uncertainties in the risk
assessment process.
ISSUE 32: GROUNDWATER RISKS
Comment: Amy Fitzgerald, ORR Local Oversight Committee, said she thinks DOE
should "commit in writing to the city and other property owners that the agency will address, and
is liable for groundwater contamination." (028769)
Comment: Ellen Smith, Environmental Quality Advisory Board, said she thinks that
nothing needs to be done to address groundwater contamination. She said she understands that
"unacceptable" levels of contaminants were found in unfiltered samples of floodplain groundwater
but not in filtered samples, indicating that the measured contamination was in soil particles
suspended in the water. She said that domestic water supply wells and delivery systems are
designed and built to exclude suspended sediment, so people would not drink the suspended
contaminants. (028767)
Response: DOE is committed to monitoring groundwater and performing periodic use
surveys to determine if EFPC groundwater aquifers are being used as potable sources. Mitigative
action would be taken if required.
JT950328.2DH/SDD luly 28 ,995
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Domestic drinking water supplies are not always filtered, so it is possible that people
would ingest suspended contaminants. For this reason, EPA protocol specifies that the presence
or absence of groundwater contamination be determined through analysis of unfiltered samples.
Risk Assessment Guidance for Superfund, Volume 1 (EPA 1989) states, "...While filtration of
groundwater samples provides useful information for understanding chemical transport within an
aquifer, the use of filtered samples for estimating exposure is very controversial because these
data may underestimate chemical concentrations in water from an unfiltered tap. Therefore, data
from unfiltered samples should be used to estimate exposure concentrations..."
ISSUE 33: MERCURY EFFECTS ON HUMANS
Two people asked if DOE would be interested in results of studies showing effects of
mercury on humans.
Comment: Alfred Brooks said there was some work done in Singapore because Chinese
traditional medicine prescribes cinnabar, which is mercuric sulfide, to calm people's nerves. He
also mentioned a reference by Goyer on human gut absorption of inorganic salts, a reference by
Frieberg on oral toxicity in humans, and a reference by Sin on human relative uptake of chloride
and sulfide in the spleen and the liver. In addition, he cited an Oak Ridge study on mice.
(PM14, PM25)
Comment: Harry Francke asked if DOE would be interested .in knowing about people
who are now suffering from mercury poisoning. (PM23)
Response: DOE recognizes that there is a great deal of uncertainty about the toxicity
of mercury. EPA has withdrawn the reference dose from its Integrated Risk Information System
because of that uncertainty.- The document submitted to EPA requesting approval of a reference
dose for mercuric sulfide included some of the references offered by Mr. Brooks. In particular,
the reference by Sin on absorption of mercuric sulfide and references ori use of
mercury-containing compounds as medications were used in that document. The other references
Mr. Brooks called to DOE's attention were used and cited in the human health risk assessment
portion of the remedial investigation report. They add weight to the conclusion that the selected
remedy will be conservatively protective of human health.
Mr. Francke and others have stated that there are people suffering from the toxic effects
of mercury exposure in the EFPC floodplain. In several public meetings, DOE has expressed
its interest in talking to or knowing the names of such individuals. To date, no affected
Ju)y 28 ,995
3-50
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individuals have come forward or been identified by name. Any exposures that may have
occurred at other sources, such as the Clinch River, tributaries beyond the influence of EFPC,
or the work place, are not the subject of this remedial action, but DOE would be happy to talk
to people who are concerned that they may have been affected.
ISSUE 34: CITIZENS WORKING GROUP
Several people discussed the Citizens Working Group.
Comment: Ellen Smith said that DOE's efforts to involve and inform the community
about the site and the remedial investigation/feasibility study process have been exemplary, with
the exception of the CERCLA/NEPA integration issue previously discussed. (028767)
Comment: Sara Childs asked for information concerning the existence of a citizens
advisory board mentioned during the public meeting. (PM43)
Comment: Sandra Reid said that the Citizens Working Group was "an obvious ploy to
make it appear that the concerns of the community were being addressed, while keeping a tight
rein on the meetings." She said there, was no outreach to Scarboro or to other impacted
stakeholders and that newcomers were prevented from joining. She said the majority of the
participants were Martin Marietta Energy Systems, Inc., employees and wrote, "one has to
question whether or not they could speak out, a difficult conflict." She concluded that the
Citizens Working Group was used to "imply consensus, agreement, and consent with the process.
That is not a true representation of all views." (028786)
Comment: Concerning the Citizens Working Group, Ralph Hutchiscn wrote, "DOE
misrepresents public opinion in the Feasibility Study. In the most egregious example, the
document claims... that the EFPC [community?] recommended a cleanup level of 200 ppm. DOE
does not explain the methodology used to elicit this recommendation, implying only that the
Citizens Working Group provided a consensus recommendation. The implication is entirely false;
from the outset, at least one member of the Working Group was steadfast in refusal to accept an
arbitrarily established cleanup level based on a mercury sulfide theory. The shortcomings of the
Working Group process aside (they were legion), DOE at least owes the public an accurate and
fair presentation of the results of the Working Group process."' (028835)
Response: The Lower EFPC Citizens Working Group was established in May 1993 to
provide the opportunity for members of the community to interact with members of the project
JT«503:8.!DH'SDD July 28. 1995
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team and provide input on the development of cleanup alternatives. From the beginning, DOE
explained that the group was neither a decision-making nor consensus-building body, and that
DOE had the legal obligation of recommending the preferred remedial alternative.
The group met monthly for more than a year. Each meeting was open to the public and
members of the media were invited to report on each meeting.
While there were members who believed the cleanup levels should be lowered and/or
studied further, the majority of the group expressed opinions that the levels were too low, based
on the form of mercury believed to be in the floodplain, and requested that DOE conduct
speciation studies to confirm that belief.
ISSUE 35: PROPOSED PLAN DIFFICULT TO UNDERSTAND
Comment: Herman Weeren wrote that the proposed plan was difficult to read and
understand. (028563)
Response: To clearly and concisely summarize the feasibility study (DOE 1994b) and
present DOE's preferred alternative, the proposed plan (DOE 1995b) was published in a fact
sheet format. Many complex issues were summarized in the 10-page document. Engineers and
scientists first wrote the plan, then professional editors, revised it to make it readily
understandable to the general public. DOE personnel are available to explain any difficult
concepts to members of the public.
COMMENTS AND RESPONSES
Second public comment period (June 14, 1995—July 13,1995)
Only public comments addressing the increase in the remediation goal were accepted
during this comment period (see Attachment 1).
ISSUE A: REMEDIATION GOAL IS TOO LOW
Comment: Weldon Dillow wrote that he felt that even though the Lower East Fork
Poplar Creek (EFPC) proposed cleanup level was revised upward from the baseline risk
JT95032S.2DH/SDD ' ,u|y M |99J
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assessment of 50 ppm to 180 ppm and then again to 400 ppm of mercury, it is still too
conservative. Mr. Dillow stated that the Monte Carlo uncertainty analysis cumulative probability
distribution for mercury in soil for the residential child scenario presented in Figure 3.3 of the
addendum to the East Fork Poplar Creek - Sewer Line Beltway Remedial Investigation Report
indicates a mercury bioavailability factor of 30 percent for a soil cleanup level of 790 ppm at the
90th percentile. Mr. Dillow felt that when the newly agreed upon bioavailability of 10 percent
is applied to the Monte Carlo uncertainty analysis, it will significantly increase the cleanup level
because the sensitivity analysis indicates a strong negative correlation between the bioavailability
factor and the cleanup level.
Mr. Dillow said that, based on the bioavailability factor, Monte Carlo calculations should
be repeated and a cleanup level selected based on a cumulative probability of 90 percent for the
residential child scenario. He felt that the revised cleanup level should not be based on a point
estimate because of the many uncertainties involved. He stated that the cleanup level would still
be conservative because of the use of a mercury bioavailable factor of 10 percent, the ultra
conservative assumption of 350 days/year exposure over a 9-year period for the exposure of
children, and the use of the average concentration of mercury in the top 18-in. of soil when the
concentrations in the surface layer accessible to children are about a tenth of the average. He felt
that most people would agree that this would still be a conservative scenario. (031399)
Comment: Martin Macher wrote that the remediation goal of 400 mg/kg seems to be
extremely conservative because the ROD says it is "orders of magnitude lower than LOAELS and
NOAEL for inorganic mercury ingestion." He felt that increasing the limit by orders of
magnitude could probably greatly reduce cleanup costs while having a relatively insignificant
effect on public health and recommended a reexamination of the cleanup level for mercury.
(031628)
Response: As stated in the Responsiveness Summary of the Record of Decision for
Lower East Fork Poplar Creek (DOE/OR/02-1370&D1), "a risk management decision has been
made to use a bioavailability factor of 10 percent for mercury in Lower EFPC soils." The 10
percent value for bioavailability corresponds to the 85th percentile of the probability distribution
for bioavailability based on site-specific measurements. In agreement with EPA, Monte Carlo
analysis was used to understand the uncertainty surrounding the point estimates of risk and
cleanup levels but not in the derivation of actual cleanup levels. As stated in Mr Dillow's
comment, the 90th percentile of the distribution of cleanup levels is approximately 790 ppm.
Repeating the Monte Carlo calculations will not change the probability distribution of the
remediation goal because none of the input probability density functions have changed (Note:
JT950328.2DH/SDD
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Even though there was a decision to use the 10 percent bioavailability factor rather than the 30
percent value in developing the point estimate of 400 ppm, the underlying probability density
function for bioavailability does not change). Therefore, repeated Monte Carlo calculations will
always place the 90th percentile of the distribution at or near 790 ppm.
Again, as stated in the response to Issue 1 for the first public comment period, it is
important to recognize that the bioavailability of mercury in Lower EFPC is not known, and
cannot be known with absolute certainty. There is limited published information specific to lower
EFPC soils. Mercuric sulfide predominates in Lower EFPC, but relative concentrations of
mercury species are undetermined. Any bioavailability value selected represents a compromise;
one which reflects an understanding of uncertainty (confidence level) surrounding the estimate.
The 10 percent value is a reasonable compromise that still affords considerable protection to
human health.
In regards to the comment provided by Mr. Macher, DOE has carefully evaluated and
reevaluated the remediation goal used for Lower EFPC. The remediation goal of 400 ppm,
although conservative, is scientifically defensible and protective of the most sensitive receptor
group (i.e., children) for direct contact with soils.
ISSUE B: REMEDIATION GOAL IS TOO HIGH
Some people commenting in the second public comment period felt the remediation goal
of 400 ppm for Hg is too high.
Comment: Jeffrey Teitel, legal counsel for Mr. Melvin Sturm and Mr. and Mrs. G.
Wayne Clark, wrote4 "Establishment of a 400 ppm action level for Hg is arbitrary and capricious,
and an abuse of discretion." He further stated, "As attorneys, not scientific researchers, we have
found no government-adopted action levels for Hg which approach 400 ppm," citing EPA's
"Draft Soil Screening Level Guidance" Fact Sheet (PB93-963508, 9355.4-14, September 1993)
and EPA's "Cleanup Criteria for Soil and Groundwater" (Table 9 - Superfund Proposed Soil
Screening Levels, from National Standards and Guidelines, Cleanup Criteria for Soil and
Groundwater). Mr. Teitel also wrote that, since there is some question about the species of
mercury present in his clients' land, a conservative cleanup level is essential. He suggested that
EPA's stated 30 percent bioavailability factor for mercury is not a sound enough basis for raising
the mercury action level to 400 ppm. (031045)
JT
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Comment: Greg Hawk of Mercury Treatment Alternatives, Inc., commented on the
issue of increasing the cleanup level from 180 ppm to 400 ppm mercury. He stated, "In this
case, the cleanup level should be dictated by the environmental and health risks associated with
both elemental mercury and mercuric sulfide since both appear to be present. When in doubt,
conservative values should be used in the risk assessment and transport calculations due to the
environmentally sensitive nature of the site and the use of the area by the public." (031392)
Comment: During the second public comment period, Melvin S. Sturm questioned the
use of 400 ppm mercury as the cleanup goal, especially as applied to the RI Phase Ib use of
homogenized samples, and requested that Parcel #563 be included in the remediation of EFPC
floodplain mercury-contaminated soils. He wrote that he does not believe enough consideration
has been given to the impact of raising the cleanup level of mercury to 400 ppm when "this new
level is combined with a sampling technique that understates the contamination level actually
present in the soil." (031369)
Response: As was stated in the response to Issue 2 in the first public comment period,
DOE conducted a comprehensive human health risk assessment to evaluate the potential health
effects associated with exposure to chemicals released from the DOE Y-12 Plant. This evaluation
was based on an understanding of the nature and extent of contamination and the inherent toxicity
of the chemicals of concern. The assessment closely followed EPA guidelines for risk
assessment, and was conducted with EPA concurrence and consensus. The basis for the 20
percent bioavailabilty factor is included in the response to Issue 1 in the first public comment
period.
The toxicity measure (RfD) for mercury used in the risk assessment was very
conservative. Use of this RfD assumes receptors are exposed to mercuric chloride. The RfD
for mercuric chloride is a very conservative value. Given that the less soluble and less
bioavailable mercury species predominate in the Lower EFPC floodplain, this RfD for mercury
affords an even higher degree of conservatism and protection to human health. Similarly, the
exposure assumptions were conservative and designed to ensure protection of children, the most
sensitive receptor.
The response to the issue of sample homogenization is provided in the response to
Issue F.
JT950328 :DH SDD _ July 21. IW5
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ISSUE C: CONCERN ABOUT CONTAMINATION IN OTHER AREAS
One commentor during the second public comment period stated a concern about
mercury contamination at another location along the floodplain.
Comment: Jeffrey Teitel, legal counsel for Mr. Melvin Sturm and Mr. and Mrs. G.
Wayne Clark, wrote that the consequence of a 400 ppm remediation goal, based on data
presented in the RI (DOE 1994a), will be no remedial action on the Sturm property, even though
the addendum to the RI (DOE 1994c) shows a mercury concentration of 1,600 ppm in a core
sample taken from the Sturm property. (031045)
Response: The areas delineating the limit of 400 ppm mercury, as provided in the ROD,
were constructed for volume, area, and cost estimation purposes. Before remedial action begins,
further sampling will be conducted to formally define all areas of soil in the floodplain with
mercury concentrations > 400 ppm. This additional sampling will be conducted in areas shown
in historical data (i.e., Tennessee Valley Authority, Oak Ridge Associated Universities, and RI
data) to have mercury concentrations in excess of 400 ppm. All areas defined in the formal
sampling will be dealt with during the remedial action. Additionally, once the excavation is
completed, an independent verification will be conducted to ensure all areas > 400 ppm mercury
have been remediated.
ISSUE D: ALTERNATIVE 3 AND/OR IMMEDIATE ACTION ALTERNATIVES ARE
THE MOST ACCEPTABLE
During the second public comment period, F. L. Harmon wrote that the 400 ppm
remediation goal provides an excellent balance between the protection of the health and safety of
the population and remediation of EFPC. (031145)
Response: The selected alternative, Alternative 3, employs the remediation goal of
400 ppm.
ISSUE E: MERCURY SPECIATION
Comment: Jeffrey Teitel, legal counsel for Mr. Melvin Sturm and Mr. and Mrs. G.
Wayne Clark, wrote, "Another consideration specifically pertinent to Hg found at EFPC is
JT9503:8.2DH/SDD July 2g ,995
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speciation." He further wrote, "Since the species of a chemical determines its toxicity, it is
important to correctly identify the species of Hg present along EFPC. Because there is some
question about the species of Hg present in the land of our clients, a conservative cleanup level
is essential." (031045)
Response: The response to this comment is covered in the response to Issue 27 in the
first public comment period section.
ISSUE F: PROPER INVESTIGATIVE PROCESS NOT FOLLOWED
Comment: During the second public comment period, Melvin Sturm wrote that the
sampling technique employed in the RI understates the contamination level actually present in the
soil. He further wrote that the homogenization of the 16-in. core samples mixed relatively clean
soil with a heavily contaminated strata, which resulted in a mercury concentration reading lower
than the true contamination present in a layer of the soil. (031369)
Response: The comment questions the practice of taking a 0-16 in. soil core,
homogenizing the core, and selecting a subsample from the homogenized mixture for analysis.
The concern is that relatively clean soil on the surface was mixed with soil from a zone of high
mercury content, thereby diluting the concentrated zone and underestimating the level of mercury
in the floodplain.
It has been recognized for some time that mercury in the floodplain is stratified in highly
concentrated zones unequally distributed throughout the soil horizon. During Phase la of the
RI, the EFPC team sampled soil at three transects in the areas previously identified as the most
contaminated sites in the floodplain. The transects analyzed samples at 1-ft intervals to a depth
of 5 ft. A vertical integration study also analyzed a series of 1-in. samples to a depth of 18 in.
The results showed that a zone about 6 in. thick (corresponding to the time of the highest releases
from the Y-12 Plant) occurred at varying depths at the Burner's and NOAA study sites.
The sampling plan developed during Phase Ib involved gathering the most information
to feasibly and timely complete the project, using available resources. Resources were not
available to provide a level of detail to a depth of 4 ft over 15 miles of the floodplain (over
4,000 samples have been taken to date). It was decided during the planning stages, and approved
by EPA Region IV in accepting the Phase Ib Sampling and Analyses Plan, that a conservative
scenario would be used in estimating contaminant concentrations for the surface soil exposure
/T950328.2DH/SDD ;u,y 2g. 1995
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pathway. That is, all mercury found in the 16-in. cores was assumed to be surface
contamination. The surface soil pathway is the most critical pathway because it includes chronic
(long-term) exposure via dermal, inhalation, and ingestion routes by children and adults. The
400 ppm cleanup level was established to protect human health using these scenarios. If the
assumption was not made that all mercury contamination is the 16-in. cores was surface
contamination, extensive contamination at depth would have been evaluated using different
parameters than the surface soil scenario (such as ingestion/inhalation on a daily basis for 30
years), yielding higher cleanup levels for subsurface areas. Consequently, an informed decision
was made to incorporate the highest concentrations of mercury in the surface soil data in order
to develop a conservative evaluation. By using a shallower interval for surface soil
characterization, mercury concentrations would be under-represented and the extent of
remediation would be insufficient. . •
mS0328.2DH/SDD • July 28. 1995
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ATTACHMENT 1
NOTICE OF RE-OPENING OF PUBLIC COMMENT PERIOD
-------
The .TTTivtv.1 amcij tvas ciipr^d man
The Oak Ridger
0*kRidtt.TN
EAST FORK POPLAR CREEK
DOE Re-Opening Public Comment Period
June 14 -July 13,1985
The Department of Energy (DOE) is accepting comments only on the cleanup
level for Lower East Fork Poplar Creek fioodpiain soils. In the Record of Decision
(ROD), this cleanup level was increased to 400 parts per million for bom human
health and ecological protection. The draft ROD and Responsiveness Summary
is available at DOE'S Information Resource Center, 105 Broadway Ave.
DOE's responses to comments and questions on the cleanup level will be available
to the public later this summer.
Submit comments to: Nelson Lingle, Chief
Oak Ridge Remediation Branch, DOE Oak Ridge Operations
105 Broadway Avenue, Oak Ridge, Tennessee 37830
IT9SOJ:8 :OH/SDO
3-60
July 26. 1995
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Benjamin/Cummings Publishing Company, Inc.
Barnett, M. O., L. A. Harris, R. R. Turner, T. J. Henson, R. E. Melton, and R. J. Stevenson.
in press. "Characterization of mercury species in contaminated floodplain soils," Water,
Air, and Soil Pollution.
Barnett, M.O. and R. R. Turner. 1995 (in press). Bioavailability of Mercury in East Fork
Poplar Creek Soils, Y-12 ER Report.
EPA (U.S. Environmental Protection Agency). December 1989. Risk Assessment Guidance for
Superfund, Volume 1: Human Health Evaluation Manual, Interim Final, OSWER
Directive 9285.7-0la, EPA-540/1-89-002.
Dobb, D., E. Miller, D. Cardenas, and K. Brown. 1994. Determination of Mercury, with
Speciation, in Poplar Creek Soil Samples, internal report. U.S. Environmental
Protection Agency, Environmental Monitoring Systems Laboratory. Las Vegas, NV.
DOE (U.S. Department of Energy). January 1, 1992. Federal Facility Agreement for the Oak
Ridge Reservation, DOE/OR-1014. U.S. Environmental Protection Agency Region IV,
Atlanta, GA; U.S. Department of Energy, Oak Ridge Operations, Oak Ridge, TN; and
Tennessee Department of Environment and Conservation, Nashville, TN.
DOE. September 1993. Treatability Study Report for Mercury in East Fork Poplar Creek, Oak
Ridge, Tennessee. Oak Ridge, TN.
DOE. 1994a. East Fork Poplar Creek—Sewer Line Beltway Remedial Investigation Report,
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APPENDIX A
COMMENTOR/COMMENt CODE/ISSUE CROSS-REFERENCE
JT950328.2DH/SDD . • July 31. 1995
-------
Name
W. W. Parkinson
Ardis LeJcbsenring
Helen. Waraksa
James Ed Westcotc
Richard & Jane Hicks
Ann & Douglas Macdonald
Alfred Brooks
Murray Rosenihal
Michael Finn
Sidney du Mont III
C. R. & A. P. Schmitt
John & Kathleen Shatter
Herman WeereB
Fred MaienscheiB
Alfred Brooks
Max Howie, Jr. (ATSDR)
James Harless
William Fulkerson (FOORNL)
Geoffrey Gleason
Alfred Brooks (13-person petition)
James Johnson, Jr.
Me J via Sturm
James PheJps
William Wilcox, Jr.
Jane Sheiton
Linda Ewald
Robin Williams
Daniel Axelrod :
]. Francis
Comment Code
-------
Name
G. Wayne Clark
Ellen Smith (EQAB)
Fred Sweeten
Amy Fitzgerald (ORR LOG)
Sandra Lock Reid
Robert Peelle
Edmund Nephew (City of Oak Ridge)
A. D. Ryon
Elizabeth Busteed
Ralph Hutchison (OREPA)
Jeffrey H. Teitel
Greg Hawk
Martin S. Macher
Weldon Dillow
F. L. Hannoh
Fred Maienschein
Al Brooks .
Ellen Smith (EQAB)
Herman Weeren
Patty Dyer
John Williams
Robert Peelle
Ardis Leichensring
Fritz McDuffie
William Wilcox
Sarah Childs .
Harry Francke
Bill Burch
Al Brooks
Comment Code
028766
028767
028768
028769
028786
028788
028789
028820
028834
028835
031045
031392
031628
031399
031145
PM01
PM02
PM03
PM04
PM05
PM06
PM07
PM08
PM09
PM10
PM11
PM12
PM13
PM14
Issues
8,16
1,9,19,24,28,29,32,34
1,6,24,28 .
8
' 2,4,7.27.31,34
1,14
1,8,9,16,25,29
3,6
2,4,7,9,24,27,28,34
- B,C,E
B
A'"
A
D
1,6
. 1,4,13
1,6,9
5
5
22
' 1.8,14
to.is
6,30
1,4
30
11
23
33
• A-3
July 31. 1995
-------
Name
Wayne Clark
William Wilcox
Ricky Williams
Fred Hannon
Fred Maienschein
Jon Johnston (FOORNL)
Elizabeth Peelle
Sarah Childs
Harry Francke
Vickie Brurabadk
Al Brook*
Herman Weereu
Elizabeth Peelle
Shannon Gorman
Sarah Childs
John Williams
Ray Hedrick
Al Brooks
Card #1"
Al Broote
Card #2 •
Card #3
Card #4
Fred Maienschein
Al Brooks
Fred Maienschein
Elizabeth Peelle
Al Brooks
Sarah ChUds
Comment Code
PM15
PM16
PM17
PM18
PM19
PM20
PM21
PM22
PM23
PM24
PM25
PM26
PM27
PM28
PM29
PM30
PM31
PM32
PM33
PM34
PM35
PM36
PM37
PM38
PM39
PM40
PM41
PM42
PM43
Issues
21
4
9,11
5,28
1
1
5.9
5
33
20
33
?
31
12
28
7
18
1,28
6 v
4
. . • 5 , , .
5
..••:•-• v „-.:•-.•• •;• -: -
26
1
26
9
26
34
A-4
July 31. 1995
-------
Name
Card #5
Card #6
Card #7
Sarah Childs
Card #8
Card #9
Al Brooks
Comment Code
PM44
*AI4S
PM46
PM47
PM48
PM49
PM50
Issues
i 'to--''
! ' V\
»
28
29
7
29
"Cards refer to comments anonymously submitted at the public meeting.
ATSDR = Agency for Toxic Substances and Disease Registry
EQAB = Environmental Quality Advisory Board
FOORNL = Friends of Oak Ridge National Laboratory
OREPA = Oak Ridge Environmental Peace Alliance
ORR LOC = Oak Ridge Reservation Local Oversight Committee
JT9S0328.2DH/SDD
A-5
July 31. 1995
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