PB94-964077
EPA/ROD/R04-94/210
February 1995
EPA Superfund
Record of Decision:
Murray-Ohio Dump (O.U. 1),
Lawrenceburg, TN
6/17/1994
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MURRAY OHIO DUMP NPL SITE
LAWRENCEBURG, TENNESSEE
RECORD OF DECISION
REMEDIAL DESIGN/REMEDIAL ACTION
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TABLE OF CONTENTS
Section Page
L Declaration. 1-1
n. Site Description, History and Summary of
Enforcement Activities. 2-1
Investigations and Studies Completed to Date 2-2
HZ. Scope and Role of Response Action. 3-1
IF. Summary of Site Characteristics. 4-1
Contaminant Characteristics 4-1
Affected. Media Characteristics 4-1
Migration Pathways 4-3
V. Summary of Site Risks. 5-1
Exposure Assessment 5-1
Toxicity Assessment 5-6
Risk Characterization 5-8
Environmental Risks 5-8
VT. Description of Remedial Alternatives 6-1
Alternative 1 6-1
Alternative 2 6-1
Alternative 3 6-3
Alternative 4 6-5
Alternatives 6-6
Alternative 6 6-8
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-ii-
TABLE OF CONTENTS (Continued)
Section Page
Alternative 7 6-10
Alternatives 6-13
VH. Comparative Analysis of
Alternatives. 7-1
VZZL Selected Remedy. 8-1
Performance Standards 8-2
Compliance Testing and Monitoring 8-4
IX. Statutory Determinations. 9-1
Protection of Human Health and Environment 9-1
Compliance withARARs 9-1
Cost-Effectiveness 9-4
Utilization of Permanent Solutions and Alternative
Treatment Technologies or Resource Recovery Technologies to
the Maximum Extent Practicable 9-4
Preference for Treatment as a Principle Element 9-5
X. Significant Changes to Alternative 7. 10-1
Appendix A ~ Letters from Support Agencies
Appendix B - Responsiveness Summary
Appendix C - Risk Assessment Certification
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-ttt-
TABLES
Number Title Page
4-1 Occurrence of Contaminants in
Subsurface Soils 4*8
4-2 Overland Flow and Former
Ponded Areas Analytical Results 4-9
4-3 Occurrence of Contaminants in
Surficial Soils 4-9
4-4 Occurrence of Contaminants in
Water and Soil from Ground-
Water Seeps 4-1O
4-5 Summary of Ground-Water
Analytical Results. 4-13
5-1 Contaminants of Concern. 5-14
5-2 Exposure Point Concentrations
for Driving COCs by Media. 5-16
5-3 Equations and Example
Calculations for the Current
Wading Scenario 5-18
5-4 Blood Lead Levels in Children. 5-19
5-5 Total Site Risk 5-2O
5-6 ELCR Associated with Exposure
to Surficial Soils (Future). 5-21
5-7 Hazard Indices Associated with
Exposure to Surficial Soils
(Future) 5-21
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IV-
FIGUKES
Number Title Page
2-1 Regional Location Map 2-7
4-1 Ground-Water Seep and
Surface Water/Sediment
Sampling Locations. 4-5
4-2 Ground-Water Sampling Points 4-6
4-3 Domestic Water Supplies
Sampled 4-7
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Murray Ohio Dump NPL Site
Record of Decision
Section/
Pagel
I. DECLARATION FOR THE RECORD OF DECISION
SITE NAME AND LOCATION
Murray Ohio Dump Site
Lawrenceburg, Lawrence County, Tennessee
STATEMENT OF BASIS AND PURPOSE
This decision document represents the selected remedial action
for the Murray Ohio Dump Site developed in accordance with the
Comprehensive Environmental Response, Compensation, and Liability
Act of 1980 (CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA) and, to the extent
practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP).
This decision is based on the contents of the administrative
record for the Murray Ohio Dump site.
The State of Tennessee concurs on the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases from this Site, if not addressed by
implementing the response action selected in this Record of
Decision (ROD), may present an imminent or substantial
endangerment to public health, welfare, or the environment.
DESCRIPTION OF THE REMEDY
This final remedy addresses remediation of ground-water/seep
contamination and soil contamination by eliminating or reducing
the risks posed by the Site, through treatment, engineering and
institutional controls.
The major components of the selected remedy include:
Constructing an enhanced single barrier cover system over
the pre-1973 disposal area;
Slope stabilization of the post-1973 disposal area with
improvements on the existing cover;
Constructing a durable surface cover over the 1973 disposal
area;
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Murray Ohio Dump NPL Site
Record of Decision
Section I
Page 2
Constructing a single barrier cover system over the overland
flow area;
Deed restrictions and fencing around the disposal areas;
Continued maintenance of the cover systems;
Site monitoring; and
Contingent construction of a seep collection and treatment
system with discharge of treated effluent to Shoal Creek or
a water treatment facility.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment, complies with federal and State requirements that
are applicable or relevant and appropriate to the remedial action
and is cost-effective. This remedy utilizes permanent solutions
and alternative treatment technologies to the maximum extent
practicable, and satisfies the statutory preference for remedies
that employ treatment that reduces toxicity, mobility and volume
as a principal element. However, because treatment of the
principle threats at the site was not found to be practicable,
this remedy does not satisfy the statutory preference for
treatment of all Site wastes as a principle element.
Because this remedy will result in hazardous substances remaining
on-Site above health-based levels, a review will be conducted at
least every five years beginning no later than five years from
the date of commencement of construction of the remedial action
to ensure that the remedy continues to provide adequate
protection of human health and the environment. Reviews may be
conducted on a more frequent bases as EPA deems necessary.
/?.
Date John H. Hankinson,
Regional Administrator
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Record of Decision
Section ff
Page!
II. SITE DESCRIPTION. SITE HISTORY, AND SUMMARY OF ENFORCEMENT
AND COMMUNITY RELATIONS
A. SITE LOCATION AND DESCRIPTION
The Murray Ohio Dump Site is located three miles southwest
of the Lawrenceburg city limits in Lawrence County,
Tennessee. It is within the boundaries of a tract of land
owned and formerly operated by the City of Lawrenceburg as a
sanitary landfill. The Site consists of two landfill areas,
covering about 0.25 and 27 acres, respectively.
Approximately eight acres of the larger landfill area were
used for waste disposal. Figure 2-1 gives the general
location of the Site.
Referring to Figure 4-2, the smaller, .25 acre area to the
northwest is known as the 1973 disposal area. The western
portion of the larger 27 acre landfill is known as the pre-
1973 disposal area, with the eastern portion of this area
being known as the post-1973 disposal area. An area not
drawn on the figure, immediately to the north and
downgradient of the larger area is known as the overland
flow area since wastes flowed from the site over the surface
to this area.
The Site occupies an elongated high spot running southeast
to northwest. It is on the crest of a hill, 40 to 100 feet
above the adjacent land. Steep slopes surround the
landfill, especially north of the Site. In general, the
natural soils that form the base of the landfill are well
drained. The Site water table is approximately 40 to 50
feet below the land's surface and is Class II. Ground-water
flow is easterly and northeasterly with interruption by
karst features. The geologic units at the Murray Ohio Dump
Site have been classified according to lithology,
environment of deposition, and visual characteristics. The
units are essentially flat-lying and increase in age with
depth.
Figure 4-1 shows the several ephemeral streams located
around the Site. Names of the major ones are Northeast
Branch, Southeast Branch, and Southwest Branch. Most are
on-Site flowing off-Site. All streams go into Shoal Creek
(off-Site to the South) which is the major collection point
in the area. Figure 4-1 also shows the five major seeps
emanating from the northern side of the larger landfill unit
and located along Northeast Branch.
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Murray Ohio Dump KPL Site
Record of Decision
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Page 2
The major recognized units at the Site are the Fort Payne
Residuum, the Fort Payne Formation, Middle Paleozoic Shales,
and the Ordovician Limestones. The Fort Payne Formation at
the Site consists of an upper siliceous limestone unit and a
shale unit. The Fort Payne is underlain by several thin
shale and shaley limestone formations (Middle Paleozoic
Shales) including, in descending order, the Maury Shale, the
Chattanooga Shale, the Mannie Shale, the Fernvale Limestone
and the Seguatchie Formation. The lowest geologic unit at
the Site, the Ordovician Limestone, consists of
undifferentiated limestones of the Maysville and Nashville
groups and is composed primarily of fine- to coarse-grained
calcarenite. Along Northeast Branch, a buff-colored,
medium-grained calcareous sandstone predominates in the
upper part of the unit.
The U.S. Bureau of the Census has estimated the 1994
population of Lawrenceburg at 10,708 persons and that of
Lawrence County at 36,435 persons. Land immediately around
the Site is considered residential and therefore any future
use scenarios on or off-Site would involve residential
exposure concentrations.
The city is mostly served by municipal potable water supply
and sewer systems with a few private water supplies. Water
for domestic and industrial use is withdrawn from Shoal
Creek and Hope Spring, both points of which are
approximately three miles upstream of the Murray Site.
There are 11 domestic wells within a one-mile radius of the
Site, 32 wells within a one- to two-mile radius of the Site,
and 30 wells within a two- to three-mile radius of the Site.
B. SITE HISTORY AMD ENFORCEMENT ACTIVITIES
Murray Ohio Manufacturing Company (Murray Ohio) began
disposing of paint and plating sludge on-Site in 1963 and
continued until December 1982. The smaller .25 acre
landfill was used for a brief period during 1973 to 1974.
Originally, the company placed its liquid wastes and sludges
containing chromium, nickel and zinc in open trenches to
facilitate dewatering. After the materials dewatered, the
trenches were backfilled. Later, Murray Ohio changed its
treatment process to produce dried filter cakes.
Approximately 3,000 cubic yards of solid wastes were
landfilled and covered between 1973 and 1982. The quantity
of liquid wastes landfilled is unknown.
In March 1979, EPA conducted a site investigation at the
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Murray Ohio Dump KPL Site
Record of Decision
Section n
Page 3
landfill. Open trenches of metal plating sludges and paint
wastes were observed, and samples were collected during the
inspection. Analysis of the samples showed elevated
concentrations of chromium and nickel in both the water and
soil at the base of the slope below the landfill used by
Murray Ohio.
In the summer of 1980, while still placing waste in the
post-1973 area of the larger landfill, Murray Ohio graded
parts of the Site and covered it with native soil to a
thickness of two to ten feet. This cap was designed to
minimize surface infiltration, control erosion, and isolate
and contain the disposed wastes. Murray Ohio also
constructed drainage ditches to intercept and divert surface
water runoff from the landfill area.
In November 1981, the Tennessee Department of Environment
and Conservation (TDEC) required that a ground-water
monitoring system be installed at the Site to comply with
Tennessee hazardous waste regulations. One well was
installed uphill from the larger landfill and three wells
were installed downhill in November 1981 and January 1982,
respectively. Sampling from these wells began in September
1982. Murray ceased disposal at the Site in December 1982.
Based on its Hazard Ranking System (HRS) score of 46.44, the
Site was listed in September 1983 on EPA's National
Priorities List (NPL).
At the direction of TDEC, early investigative work began in
May 1984 for the Murray Ohio Dump Site. Beginning in June
1985, drilling of new wells and further sampling at the Site
were conducted under a second phase of investigative work.
Until the summer of 1989, TDEC was responsible for oversight
of the investigative work at the Murray Ohio Dump Site.
After the State had preliminarily investigated and
characterized the waste, EPA took over the lead oversight
role via an Administrative Order on Consent (AOC). In this
March 1990 AOC, Murray agreed to fund RI/FS activities for
the Site.
The RI/FS, with oversight by EPA, was conducted from
September 1990 to October 1993. Activities performed can be
grouped into the following categories: planning and
preparation, field activities (including sampling),
laboratory analysis, data validation, evaluation and
analysis, and report preparation. Specific objectives of
the RI were:
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Murray Ohio Dump KPL Site
Record of Decision
Section IT
Page 4
To further characterize wastes remaining at the Site;
to define the set of Site-Specific contaminants
attributable to the Site;
to define the areal and vertical extent of any Site
soil contamination;
to identify site-related contamination in the sediments
of Northeast Branch, Southeast Branch, and Southwest
Branch and to evaluate potential for contaminants to
migrate into Shoal Creek and other streams around the
site;
to define the ground-water flow regime beneath the Site
and its relationship to Northeast Branch, Southeast
Branch, Southwest Branch, Shoal Creek, and other
streams around the Site;
to define the extent of Site-related ground-water
contamination;
to define the extent of Site-related surface water
contamination in Northeast Branch, Southeast Branch,
and Southwest Branch, and to evaluate potential for
contaminants to migrate into Shoal Creek and other
streams around the site;
to ascertain any Site-related air risks;
to collect sufficient data to complete an accurate
topographical Site map, including the location of all
service buildings, fencelines, property boundaries and
the like; and
to produce a map showing the relationship of the Site
to the residences, schools, churches and daycare
centers within a one-half, one, two and three mile
radius of the Site.
The following field sampling activities were undertaken as
part of accomplishing these objectives:
Soil samples were collected from:
The pre-1973 disposal area of the larger landfill;
the post-1973 disposal area of the larger landfill;
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Murray Ohio Dump NPL Site
Record of Decision
Section JJ
PageS
the smaller 1973 to 1974 disposal area;
the area immediately downgradient to the southeast of
the larger landfill; and
the area immediately to the north and downgradient of
the larger landfill, or, the "overland flow area".
Surface water and sediment samples were collected from:
Northeast Branch upstream, downstream, and adjacent to
the Site;
Southwest Branch upstream, downstream and adjacent to
the Site;
Southeast Branch;
the confluence of Southeast and Southwest Branches; and
the confluence of Northeast Branch', and Shoal Creek.
Ground-water seep and seep soil samples were collected along
Northeast Branch at the point of contact between bedrock and
overlying soils. Ground-water samples were collected both
on-Site and on properties adjacent to the Site.
Murray Ohio retained Geraghty & Miller, Inc., to perform
field activities and prepare documents relating to the
RI/FS. EPA oversight work was conducted by Lee Wan &
Associates and later by CDM. The RI is discussed in more
detail in Section IV of this document.
C. COMMUNITY RELATIONS ACTIVITIES
A Community Relations Plan for the Murray Ohio Dump Site was
finalized in August 1990. This document lists contacts and
interested parties throughout government and the local
community. It also establishes communication pathways to
assure timely dissemination of pertinent information.
Also in August 1990, EPA held a RI/FS kickoff meeting.
Prior to this in June 1990, EPA conducted community
interviews to assess public interest and concerns.
The RI and FS reports were finalized in February 1993 and
February 1994, respectively. These reports and all other
documents concerning the Site have been made available to
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Murray Ohio Dump NPL Site
Record of Decision
Section IT
Page 6
the public in the Murray Ohio Dump NPL Site Information
Repository in the Lawrenceburg Public Library on East Gaines
Street in Lawrenceburg.
The Proposed Plan was sent out to the public on February 23,
1994, and a public meeting to discuss the Proposed Plan was
held on March 8, 1994. This meeting was used to gain
insight on public opinion concerning the remedial
alternatives.
A public comment period was held on the Proposed Plan from
February 26 to March 29, 1994. Comments received have been
incoporated into the Responsiveness Summary (Appendix B) of
this document.
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Page 2-7
REFERENCE:
U.S.Q.S. 7.5 MinuMl S»rws
) EitMridg* OuadrmngK, T
b) Lmrtnoiburg quadrangle. T
AWRENCEBURG
OlB SHOAL
f CHEEK DAM ,
Murray Ohio
Disposal Site
EXPLANATION
Appronmat* City Limit Boundary
SCALE
5000ft
L
Murray Ohio
Regional Location Map
Disposal Site Lawrenceburg. Tennessee
FIGURE
2-1
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Hurray Ohio Dump NFL Site
Record of Decision
Section HI
Pagel
III. SCOPE AND ROLE OF THE RESPONSE ACTION
The scope of this response action is to address remaining soil
and ground water/seep concerns at the Site. As discussed
previously in Section II of this document, actions were
implemented in the summer of 1980 to grade parts of the Site and
cover it with a layer of native soil. Drainage ditches were also
constructed to intercept and divert surface water runoff from the
landfill area. Also in place was a small ground-water monitoring
well network, as required by TDEC prior to EPA's involvement.
During the developmer... of the EPA RI, areas of concern were
delineated for soil (contamination was mostly metals) in and
immediately around the disposal areas. Of the most concern among
these was the 'overland flow area", an area to the north,
immediately downgradient of the larger landfill where
contamination had migrated via surface water runoff. It was
also found during the RI that infiltration of precipitation
through the wastes placed on-Site had caused downward migration
of these contaminants into the upper aquifer beneath the Site.
Further, these contaminants were found to exit the upper aquifer
via various seeps found along Northeast Branch.
The FS determined that the most effective method of treating the
contaminated ground water, which runs through highly fractured .
and solutionally enlarged conduits in the bedrock, is to block
infiltration by augmenting the cap areas at the Site, allowing
the remaining contaminants beneath the Site to exit via the
seeps. Seeps will be monitored in a manner consistent with
accepted karst monitoring practices quarterly up to twenty
quarters or 5 years, in conjunction with the five-year-review
process. (See Section VIII of this document for the monitoring
plan.) Upon evaluating results of this monitoring program (at
the time of the five-year-review), EPA will make a determination
on whether or not to construct a seep collection and treatment
system at the Site. If the seep system is required, discharge of
the treated water would be to Shoal Creek.
This selected alternative for the Murray Ohio Dump Site will
address all known concerns at the Site. It is intended to
address the entire Site with regards to threats to human health
and the environment posed by the Site, as indicated by the Risk
Assessment included in the February 1993 RI report and revised by
EPA in the February 1994 FS report. Findings of the Risk
Assessment are summarized in Section V of this document.
This is the only ROD contemplated for this Site.
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Murray Ohio Dump NPL Site
Record, of Decision
Section IV
Pagel
IV. SUMMARY OF SITE CHARACTERISTICS
A. CONTAMINANT CHARACTERISTICS
The primary contaminants of concern at the Site are chromium
and nickel, of which chromium is mostly hexavalent.
Sediment and soils are the probable repositories for most
metals emitted into the environment. Inorganic molecules
such as these have a high affinity for adsorption to soil
and sediment under the right conditions. This, in turn,
considerably restricts the molecule's mobility through the
media. As a result, inorganics tend to not migrate
substantially in soil and sediment except during erosion and
heavy runoff periods and under certain soil pH conditions.
An important factor affecting adsorbance is pH of the soil
or sediment. Inorganic adsorption is much higher at
elevated pH levels. The redox potential (Eh) of a molecule
also affects sorption and solutioning as it determines the
oxidation state of a metal. Adsorption of metal cations
increases with decreasing valence.
Nickel and chromium III are both expected to sorb well to
soils and sediments, whereas chromium VI (also called
hexavalent chromium) is a more water soluble contaminant due
to the higher valence of chromium in this form. This is
evidenced at Murray by the fact that more hex chromium was
found in ground water and seep water whereas trivalent
chromium was found more in soils and sediments.
B. AFFECTED MEDIA CHARACTERISTICS
For Site management purposes, the Murray Ohio Dump Site can
be divided into specific affected media. The following
discussion summarizes the characteristics of each media that
are relevant to the identification, screening, and selection
of remedial technologies and strategies. For more detailed
information on sampling and results, refer to the Remedial
Investigation Report on file in the Administrative Record
for the Murray Ohio Dump NPL Site.
1. Soil
The EPA Remedial Investigation at the Site took
surficial and deeper (below and including the existing
clay cover) soil samples in the following areas:
the pre-1973 disposal area of the larger landfill;
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Hurray Ohio Dump KPL Site
Record of Decision
Section IV
Page 2
the post-1973 disposal area of the larger
landfill;
the smaller 1973 to 1974 disposal area;
the area immediately downgradient to the southeast
of the larger landfill; and
the area immediately to the north and downgradient
of the larger landfill, or, the "overland flow
area".
Deeper soil borings below the clay covers were found to
contain unacceptable levels of chromium, lead, nickel
and zinc. Soil borings with paint waste mixed in were
found to contain elevated levels of toluene, xylenes,
and ethylbenzene. Acetone, 2-butanone, methylene
chloride, 4-methyl-2-pentanone, 2-methylnephthalene,
and naphthalene were also detected in subsurface soils.
Analytical breakdowns on subsurface soil samples can be
found in Table 4-1.
Surficial soils in the overland flow area were found to
contain unacceptable levels of nickel and chromium.
Table 4-2 gives a breakdown on analytical results for
each sample taken in the overland flow area and Table
4-3 shows results for other areas.
A geotechnical investigation was also performed on the
clay cover and can be found in Appendix F of the
Remedial Investigation report. Parameters such as cap
thickness, hydraulic conductivity and compaction were
tested. Based on the results of this investigation,
EPA has concerns regarding the structural integrity and
adequacy of long-term protection provided by the cover.
Surface Water and Sediments
Surface water and sediment samples were collected as
part of the RI from:
Northeast Branch upstream, downstream, and
adjacent to the Site;
Southwest Branch upstream, downstream, and
adjacent to the Site;
Southeast Branch;
the confluence of Southeast and Southwest
Branches; and
the confluence of Northeast Branch and Shoal
Creek.
Sampling locations are shown in Figure 4-1 of this
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Murray Ohio Dump NPL Site
Record of Decision
Section IV
Pages
document.
In surface water, chromium and nickel were detected at
elevated concentrations near the head of Northeast
Branch. Concentration levels decline in the downstream
direction and are equal to background concentration
before Northeast Branch enters Shoal Creek. No other
streams around the Site contained significant
concentrations of any contaminants.
In sediments, contaminant concentrations tend to follow
trends in surface water, i.e., elevated concentrations
of chromium and nickel were detected at the head of
Northeast Branch, declining towards background at the
confluence with Shoal Creek. No other significant
concentrations of contaminants were detected in
sediments in other streams around the Site.
3. Ground-water Seep and Seep Soils
Ground-water seep and seep soil samples were collected
along Northeast Branch at the point of contact between
bedrock and the overlying soils. Locations can be
found in Figure 4-1 of this document or in the RI
report.
Work was supervised by TDEC and then EPA on several
occasions from 1984 to 1990 when seeps were found to be
flowing. Results from these investigations confirmed
impact above acceptable levels along Northeast Branch.
Seep soils were sampled concurrently with running
seeps. Samples showed impacts for chromium, nickel,
lead and zinc. One organic compound, trichloroethene,
was found at elevated levels in seep soils. For more
detailed analytical results, refer to Table 4-4 of this
document.
Ground water
Ground water was sampled on-Site in November - December
of 1990 as part of the EPA RI. Samples were taken from
14 wells and were drawn mostly from the upper aquifer,
the Fort Payne Formation. Samples were also collected
from other underlying zones. Ground-water
contamination was found in the Fort Payne Formation,
but not the lower aquifer. Impacts for chromium,
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Record of Decision
Section/V
Pope 4
nickel, cadmium and lead were noted in the Fort Payne.
For a breakdown on the exceedances at each sampling
location, refer to Figure 4-2, which shows ground-water
sampling locations, and Table 4-5 which gives
analytical results for each contaminant at each
location.
Referring to the February 1993 RI report, the on-Site
square footage associated with ground-water exceeding
Maximum Contaminant Levels (MCLs) is estimated to be
444,800 square feet. The corresponding contaminated
pore volume is estimated to be 37,765,024 gallons, or
4,948,800 cubic feet.
Ground water was also sampled at off-Site residential
locations by TDEC and Murray Ohio over a three year
period from 1987 to 1990. Figure 4-3 shows locations
where wells and springs were sampled. All results were
well below drinking water standards.
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Page 4-5
Murray Ohio
Disposal Site
EXPLANATION
Surface-Water and Sediment
Sampling Location
Ground-Water Seep and Soil
Sampling Location
Rapid Bioassessment
Acute Toxicity Testing
Surface water adjacent to this
seep was sampled in 1991
Ground-Water Seep and Surface-Water/Sediment
Sampling Locations
Murray Ohio Disposal Site Lawrenceburg. Tennessee
FIGURE
4-1
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EXPLANATION
5A Unconsolidaled Zone Monitor-Well
Location and Number
Fort Payne Bedrock Monilor-Well
I _~«llAM nnjj Mlunluw
Location and Number
* Deep Bedrock (Ordovician Limestone)
Monitof-Wcll Location and Number
1990 Ground-Water Sampling Points
Murray Ohio Disposal Site Lawrenceburg, Tennessee
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Page 4-7
Lawrancsburg 1 CROCKETT
Newton Weim
Taylor Well
Johansik We//@
^ Bailey Spring
Murray Ohio
Disposal Site
EXPLANATION
Domestic Well Location
Sampled Well
Sampled Spring
Domestic Water Supplies Sampled by
TDHE and Murray Ohio
Murray Ohio Disposal Site Lawrenceburg, Tennessee
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Page 4-8
Table 4-1 Occurrence of Contaminants Detected in Subsurface Soils, Murray Ohio Disposal Site, Lawrenceburg, Tennessee.
Frequency of
Contaminants Detection
INORGANICS
Aluminum
Arsenic
Barium
Cadmium
Chromium (total)
Chromium VI
Cobalt
Cyanide
Copper
Iron
l,ead
Nickel
Vanadium
Zinc
VOCs
Acetone
2-Butanone
Ethylbenzene
4-Methyl-2-pentanone
Methylene chloride
Toluene
Xylenes
1/2
1/2
1/2
16/51
50/51
4/37
1/2
3/18
1/2
50/51
24/51
49/51
1/2
49/51
1/4
4/4
7/18
2/4
1/4
7/18
7/18
8,300
6
13
0.083
1.1
0.95
4.8
0.28
21
260
3.9
8.5
34
30
0.37
0.82
0.003
5.7
0.18
0.049
0.021
Range
- 8,300
6
13
13
- 1,000
1.6
4.8
3.8
21
- 32,000
800
880
34
- 1,100
0.37
0.98
890
6.8
- 0.18
- 5,800
- 4,700
Arithmetic Mean
Total Detects
8,300
6
13
0.7
88
0.25
2.4
0.37
10.5
15,000
31
150
17
110
0.15
0.4
80
3.1
0.061
500
430
8,300
6
13
1.7
90
1.2
4.8
1.6
21
15,000
62
154
34
119
0.37
0.4
206
5.7
0.18
1,300
1,100
UCL
NA
NA
NA
1.1
130
0.35
18
0.73
77
17,000
58
190
120
150
0.32
0.9
170
7.4
0.16
1,100
920
Site**
Background
(50,000)
(6.5)
(500)
(NA)
15
(10)
-.
(10)
16,850
42
(5)
(30)
180
~
~
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Table 4-2 Overland Flow and Former Ponded Areas Analytical Results
Murray Ohio Disposal Site Liwrenceouiv. Tennessee
Page 4-9
Sample
fdvfiilficatiofi
Overland Flow Area
OF-1
OF-2
OF-3
OF-4
. OF-5
OF-6
OF-7
OF-8
OF-9
OF-10
OF-11
OF-12
OF-13
OF-14
OF-15
OF-16
OF-17
OF-18
OF-19
OF-20
OF-21
OF-22
OF-23
OF-24
OF-25
OF-26
OF-27
OF-28
OF-29
OF-30
OF-31
OF-32
OF-33
OF-34
OF-35
OF-36
OF-37
OF-38
OF-39
Deep Sample #1 (OF-5)
Deep Sample #2 (OF-30)
Foe met Ponded Arcs
PA-l
PA-2
PA-3
PA-4
PA-5
PA-6
PA-7
Backeround
BG-1
BG-2
BG-3
Data
Sampled
5/11)93
5/11)93
5/11)93
5/11/93
5/11/93
5/11)93
5/1 1/93
5/1 1193
5/11/93
5/11)93
5/11/93
5/11)93
5/1 1/93
5/1 D93
5/11/93
5/11/93
5/11/93
5/11)93
5/11/93
5/11)93
5/11/93
5/11)93
5/12/93
5A2/93
5/12/93
5/12/93
5/12/93
5/12/93
5/12/93
5/12/93
5/12/93
5/12/93
5/12/93
5/12/93
5/12/93
5/12/93
5/12/93
5/12/93
5/12/93
5/13)93
5/13/93
5/12/93
5/13)93
5/13/93
5/13/93
5/13/93
5/13/93
5/13/93
5/12/93
f/12/93
5/12/93
Total Cr
(ing/kg)
16
1.090
26
23
356
278
12
17
19
11
42
202
156
302
436
30
523
511
361
32
3.730
112
1080
377
1O50
194
212
547
162
213
520
«
4.830
54
19
165
19
124
25
1.080
53
15
14
42
i9
_j
! i
:3
:o
;<
:o
HeoTaJentCr
(tog/kg)
OOOU
OOOU
0.20 U
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
0.20 U
OOOU
1.8
OOOU
OOOU
OOOU
OOOU
1.4
0.20 U
0.70
OOOU
1.7
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
5.7
0.86
0.20 t'
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
OOOU
Nickel
(tng/kg)
24
3.040
83
52
1980
552
*^mt
19
54
12
21
»*
1.110
*3 13
285
661
765
24
1.470
546
2.130
202
3.650
935
900
893
1080
918
134
110
641
428
1.560
18
6.910
151
592
1.110
244
160
52
942
79
27
*0
98
96
:8
67
:o
:3
5
[.-. -n.t
I (or. but wu noc detected.
en ««ue u me samoie ouwuuuon limit.
-------
Page 4-10
4-3
Contaminants
^
^^^^^^^^^^^^^
Inorganics
Aluminum
Arsenic
Barium
Calcium
Chromium
Cobalt
Iron
Lead
Magnesium
Manganese
Nickel
Potassium
Vanadium
Zinc
Pesticides
Endosulfan I
1
Frequency
Detects / Total
^ 1^l
^ ^_ _
4/4
4/4
4/4
4/4
8/9
4/4
9/9
5/9
4/4
4/4
9/9
4/4
4/4
9/9
1 /4
' _
Ranee of Dcj/^-tc
Min -Max
^^^^^^ ^ i n-^^^_^^_
7,600 - 9,700
4.9 - 8.0
54-200
1,600 - 24,000
13.0 - 145
14-24
14,000 - 123,000
8.9 - 94
430-2,100
820 - 3,000
13 - 278
540-990
20-34
24-71
0.0029 - 0.0029
1
.
Arithmetic Mean
Total
8,500
6.1
130
9,300
35
19
29,000
17
1,000
1.800
65
780
26
46
0.002
Detects
^"""^^^^^^^^^W
8,500
6.1
130
9,300
39
19
29,000
28
1,000
1.800
65
780
26
46
0.003
UCL
^^^^^^^^^^^^^^^
9,600
7.7
220
21,000
62
24
51,000
35
1,900
2,900
120
1,000
33
55
0.0026
.
Background*
Mean
^ ^^^^^
^^^^^^^«^^^^»
(50,000)
(6.5)
(500)
(2,300)
12
(10)
10,300
(15)
(1,500)
335
6
(6.800)
(30)
13
.
Concentrations are given in milligrams per kilogram (mg/kg).
List includes all contaminants which were detected at least once.
* Concentrations in parentheses are regional background means reported by CDM (Appendix A); other values
are from boring 17A, 0 to 5 feet sampling interval (Geraghty &. Miller, 1990).
Not detected in background samples.
Mean Arithmetic average of the total number of samples, using one-half the detection limit for non-detects.
UCL 95 percent upper confidence limit (one-tailed normal distribution) on the arithmetic mean.
-------
Pag -11
Table 4-4 Occurrence of Contaminants in Water and Soil from Ground-Water Seeps, Murray Ohio Disposal Site, Lawrenceburg,
Page 1 of 3
Tennessee.
Contaminants
Frequency
of Detection
Range
Arjlhmetip Mean
Total Detects
UCL
INORGANICS
METALS
Cadmium
Chromium (total)
Chromium VI
Iron
Magnesium
Manganese
Nickel
Zinc
4/6
6/6
3/5
2/6
5/6
6/6
5/6
1/6
0.0003
0.01
0.03
0.08
3.5
0.05
0.06
O.I
0.0007
1.4
1.5
0.49
11
1.2
2.9
0.1
SEEP WATER
0.00035
0.56
0.55
0.11
5.9
0.45
0.99
0.034
0.0007
0.56
0.91
29
6.7
0.45
1.2
0.1
0.00054
1
1.3
0.27
9.2
0.81
1.9
0.063
ANIONS
Bicarbonate
Carbonate
Chloride
Cyanide
Nitrale-N
Sul fate
3/5
3/5
5/5
1/6
5/5
5/5
210
0.2
7
0.005
0.2
28
340
0.4
35
0.005
2.9
130
190
0.29
15
0.0029
0.8
77
290
3
15
0.005
0.8
77
330
0.46
26
0.0038
1.9
130
-------
Page 4-12
Table 4-4
Occurrence of Contaminants in Water and Soil from Ground-Water Seeps, Murray Ohio Disposal Site,
Lawrenceburg, Tennessee.
Page 2 of 3
Contaminants
CATIONS
CaJcium
Potassium
Sodium
ORGANICS
1 ,2-DichIoroelhene
Toluene
Trichloroethene
INORGANICS
METALS
Aluminum
Arsenic
Barium
Beryllium
Chromium (total)
Cobalt
Copper
Iron
I^ad
Frequency
of Detection
6/6
5/6
6/6
2/2
2/5
2/2
1/1
1/1
1/1
1/1
6/6
1/1
1/1
6/6
2/6
29
0.65
8.6
0.013
0.006
0.13
12,000
5
130
0.74
120
50
56
1,200
6.8
Range
140
i.r
44
- 0.015
- 0.008
0.14
- 12,000
5
130
0.74
- 1,100
50
56
- 12,000
80
Arithmetic
Total
75
0.7
24
0.014
0.0043
0.13
SEEP SOIL
12,000
5
130
0.74
500
50
56
4,300
17
Mean
Detects
75
0.78
24
0.014
0.007
0.13
12,000
5
130
0.74
500
50
56
4,300
43
UCL
120
0.92
37
0.02
0.0067
0.16
'
830
~
--
7,700
42
-------
Page 4-13
Table 4-4
Occurrence of Contaminants in Water and Soil from Ground-Water Seeps, Murray Ohio Disposal Site,
jM'urr i VIIK***ISUI g, i vi 1 1 iwaa«*^ . o r o
Contaminants
Magnesium
Manganese
Mercury
Nickel
Selenium
Silver
Vanadium
Zinc
ANIONS
Cyanide
CATIONS
Calcium
Potassium
Sodium
ORGAN1CS
Trichloroethene
Frequency
of Detection
6/6
6/6
1/1
6/6
1/1
I/I
1/1
6/6
I/I
6/6
6/6
2/2
2/2
47
420
0.27
42
0.4
0.045
14
19
0.43
460
64
21
0.13
Range
600
- 3,100
0.27
780
0.4
- 0.045
14
100
0.43
- 2,200
490
36
- 0.21
Arithmetic
Total
180
1,000
0.27
440
0.4
0.045
14
44
0.43
1,300
180
29
0.17
Mean
Detects
180
1,000
0.27
440
0.4
0.045
14
44
0.43
1,300
180
29
0.17
UCL
350
1,900
670
70
--
1,800
310
76
. 0.44
All surface-water concentrations are in milligrams per liter (mg/L) and surficial soil concentrations are in milligrams per kilogram
(ing/kg).
UCL Upper 95 percent confidence limit on the arithmetic mean.
No data available.
-------
Page 4-14
Table 4-5 Ground Water Summary of Analytical Results
Sample Location:
Sample ID:
Date Sampled:
Monitored Zone:
Constituent
Cadmium
Calcium
Chromium
Chromium, hcxavalcnl
Iron
l.i-a.l
Magnesium
Manganese
Nickel
I'nlassiuin
Sodium
Zinc
Cyanide (total)
( 'hloride
Nitrate
Sulfaic
Sulfidc
Alkalinity (total)
Curlxinalc
Hicarbonate
Hydroxide
1101)
COD
C02l;ree
pll (Lab) (pH units)
pi 1 (held) (pi I units)
111 ll/l'IIC (P|'l>)
Toluene (|'|>b)
Eihylhenzcnc (ppb)
Xyltncs (|'|ib)
MW-1B
in-2
12/6/90
OL
0.0014
36 U
0.01 U
0.01 U
1.8U
0.036
7.7
0.04
0.05 U
3.2
40
O.I6UJ
0.005 UJ
3.6 U
l.OU
l.OU
0.2 U
151
IU
151
l.OU
201)
797 J
91 U
6.52
6.28
1 U
SOU
1 U
2U
MW-3B
3B-2
12/7/90
FPF
0.0052
68
0.01
0.18
0.9 U
0.057 J
26
0.10
0.05 U
5.0
25 J
0.06 UJ
1 I)
II U
1 U
21)
Murray Ohio
MW-4B
4B-2
12/7/90
FPF
0.0028
67
0.01 U
0.01 U
0.03 U
0.004 UJ
7.7
0.03
0.05 U
2.0
1.2UJ
0.10UJ
0.005 U
111)
O.IU
1.4 J
0.2 U
164
0.3
164
l.OU
6
81)
0.3
7.21
1 U
6U
IU
2U
Disposal Site Lawrenceburg, Tennessee Paee 1 of 3
MW-5A
5A-2
12/2/90
FPR
5
5U
1 U
2U
MW-5B
5B-2
12/5/90
FPF
0.0016
66
0.01 U
0.01 U
0.46 U
0.004 U
22
0.07
o:os u
2.7
I2J
0.02 U
0.006
0.2 UJ
164 J
0.2
164
l.OU
5
99 UJ
21
7.20
IU
12 U
IU
2U
MW-5B
5B-2-F*
12/1.5/90
FPF
0.0002 J
70
0.01 U
0.01 U
0.17U
O.IXM U
24
0.04
0.05 U
1.7
12 J
0.02 U
0.005
0.2 UJ
160 J
IU
3.0 U
l.OU
0.1
7.66
MW-5C
5C-2
12/5/90
OL
0.0002 U
270
0.01 U
_
0.60 U
0.004 UJ
57
0.06
0.05 U
6.2
120 J
0.04 U
0.005 U
38 U
O.IU
I.400J
0.2 UJ
138
0.3
138
l.OU
54 UJ
11
7.40
7.19
IU
79
IU
2U
MW-5C
5C-2-F*
12/2.5/90
OL
0.0002 U
170
0.01 U
0.01 U
0.23 U
0.004 UJ
40
0.02
0.05 U
4.2
98 J
0.02 U
0.005 U
40 U
O.IU
1.128J
156
0.5
155
l.OU
9.4
7.52
MW-6A
6A-2
12/2.3W
FPR
0.0004
9.5 U
0.01 U
0.01 U
0.15 U
0.004 U
2.8
0.06
0.05
0.60 U
1.4UJ
0.02 U
0.005 U
12 U
O.IU
17
0.2 UJ
50
IU
50
l.OU
9
7U
7.4
7.13
6.45
IU
5U
IU
2U
MVV-6U
6B-2
12/6/90
FPF
0.(XKI2
no
0.48
0.43
0.091)
0.001 J
24
0.0!)
0.05 U
2.0
24
O.I9UJ
0.007 J
3311
l.OU
119
0.2 U
220
0.3
220
l.OU
1 1)
20 UJ
29
7.18
7.09
1 U
511
1 U
21.1
NOTE: All concentrationi reported in pans per million unless noted otherwise.
ppb'- paru per billion
OL - Ordovician Limestone
IW - Fort Payne Formation
FPR Fort Payne Residuum
Parameter not analyzed for in this sample.
Filtered Sample
U The parameter was analyzed for, but was not delected.
The associated numerical value is the sample qtianiilaiion limit.
J The associated numerical value is an estimated quantity.
(U - The parameter was analyzed for, but was not detected.
Ihe sample quanlilation limit is an estimated quantity.
-------
Page 4-15
Table 4-5 Ground Waler Summary of Analytical Results
Murray Ohio Disposal Silc Lawrenceburg. Tennessee
Page 2 of 3
Simple Location:
Sample ID:
Dale Sampled:
Monitored Zone:
Constituent
Cadmium
Calcium
Chromium
'Chromium, hcxavaluii
Iron
Lead
Magnesium
Manganese
Nickel
I'oiassiiuii
Sixliuin
Zinc
Cyanide (total)
Chloride
Nilralc
Siilfatc
Sulfide
Alkalinity (loial)
Carbonate
Bicarbonate
Hydroxide
HOD
COD
C02 Prcc
|>ll(l.ab)
pi 1 (Field)
Hciucnu
Toluene
liiliylbcnzcnu
Xylcnes
(pll units)
(pll units)
(PI*)
(ppb)
(PI'b)
(ppb)
MW-8A
8A-2
ll/30;12/3,4/90
FPR
0.0006
I9U
0.04
0.09
1.2 U
0.046 J
3.5
1.8
0.57
1.4
7.8J
0.12U
0.005
0.2 U
28 U
1U
28 U
1.0 U
4U
70 UJ
22 U
6.41
5.60
1U
5U
IU
2U
MW-8B
8B-2
11/30/90
FPF
0.0002 U
123
2.2
2.5
0.06 U
0.004 U
32
0.04
0.05 U
3.5
53
0.22 U
0.005 U
33 U
1.4 U
243
0.2 U
193
0.4
193
1.0 U
13
82 U
0.4
7.38
6.94
IU
5U
IU
2U
MW-8B
8B-2-F*
11/30/90
FPF
0.0002 UJ
106
2.1
2.6
0.03 U
0.004 U
32
0.03
0.05 U
3.6
51
0.02 U
0.005 U
33 U
1.4 U
171
0.2 UJ
193
0.6
192
1.0 U
0.6
7.50
MW-9A
9A-2
11/30; 12/3.4/90
FPR
0.0002 U
8.3 U
0.01 U
0.14
0.19U
0.004 U
2.6
0.06
0.05 U
1.1
3.3 UJ
0.02 U
0.005 U
0.2 U
76
IU
76
1.0 U
4U
95 UJ
39
6.59
1 U
5U
IU
2U
MW-9A
9A-2-F*
12/3.4/90
FPR
0.0005
34 U
0.01 U
0.1 IU
0.004 U
11
0.05
0.05 U
1.5
5.8 J
0.07 U
MW-10A
10A-2
12/3.4/90
FPR
0.0021
9.8 U
0.01 U
0.01 U
2.5
0.010
2.0
1.0
0.05 U
2.3
0.2 UJ
0.03 U
0.005 U
0.2 U
22 U
IU
22 U
1.0 U
4U
7UJ
11U
6.62
1 U
5U
IU
2U
MW-10B
10B-2
12/3.4/90
FPF
0.0002 U
820
0.02
0.04
1.1U
0.005 J
2.6
0.02
0.05 U
6.0
I8J
0.02 U
6.580
5,617
32 U
931
1.0 U
12.27
IU
9U
IU
2U
MW-12A
12A-2
12/6/90
FPR
0.0030
20 U
0.01 U
0.01 U
0.69 U
0.004 UJ
2.1
0.97
0.06
0.78
0.2 U
0.14 UJ
0.005 U
2.6 U
0.1 U
9.4 J
0.2 U
56
IU
56
1.0 U
IU
7U
1.0 U
7.26
6.71
IU
5U
IU
2U
MW-13A
I3A-2
12/2.3/90
FPR
0.0002 U
54 U
0.01 U
0.01 U
0.36 U
0.00-1 U
II
0.08
0.05 U
1.1
2.3 UJ
0.02 U
0.005 U
1.5 U
O.I U
10 U
0.2 UJ
98
0.1
98
1.0 U
IU
24 U
33
6.77
6.43
1 I)
6U
IU
2U
MW-I3A
13A-2-K*
12/3.4/90
FPR
0.0006
36 U
0.01 U
0.01 U
0.03 U
0.004 U
5.3
0.05
0.05 U
0.6H
I.4UJ
0.02 U
2.1 U
0.1 U
10 U
0.2 UJ
112
O.I
112
I.OU
__ _.
20
7.0-1
NOTE: All concentrtUoni reported in pirti per million unleii noted olherwiie.
ppb- pul> per billion
OL- Ordoviciin Limestone
I-PP- Fort Payne Formation
FPR- Port Payne Residuum
Parameter not analyzed for in ihis sample.
l-'iltcrcd Sample
U - The parameter wu analyzed tot, but wai not delected.
The associated numerical value It the ample quantiiaiion limit.
J - The associated numerical value if an estimated quantity.
UJ The parameter wu analyzed for. but wu not delected.
1"he sample quanlilation limit ii an estimated quantity.
-------
Page 4-16
Table 4-5 (.'round Water Summary or Analytical Results
Murray Ohio
Sample Locution:
Sample ID:
l>«lc Sampled:
Monitored Zone:
Constituent
Cadmium
Calcium
Chromium
Chromium, hcxavalunl
Iron
Lead
Magnesium
Manganese
Nickel
Potassium
Sodium
Zinc
Cyanide (total)
Chloride
Niiraie
Sulfalc
Sulfidc
Alkalinity (total)
Carbonate
Bicarbonate
Hydroxide
HOD
COD
CO2 Free
pH (Lab)
pH (Field)
Benzene
Toluene
Eiliylbcnzene
Xylcncs
(pH units)
(pH units)
(|>pb)
(ppb)
(ppb)
(Ppb)
MW-14A
14A-2
12/2,3/90
FPR
0.0003
55 U
0.01 U
0.0! U
0.39 U
0.004 U
6.6
0.25
0.05 U
1.1
0.2 UJ
0.02 U
0.005 U
1.5U
0.1 U
10 U
0.2 UJ
148
0.2
148
1.0 U
9
26 U
20
7.16
7.47
1U
5U
iu
2U
MW-14B
14B-2
12/6/90
FPF
0.0004
52 U
0.01 U
0.01 U
0.03 U
0.004 UJ
7.4
0.01 U
0.05 U
0.77
0.6 U
0.02 UJ
0.005 U
1.5 U
0.1 U
11 UJ
0.2 U
151
0.4
151
1.0 U
IU
7U
9.7
7.49
7.92
1 U
6U
IU
2U
MW-14B
140-2-Dt
12/6/90
FPF
o.txxxs
54 U
0.01 U
0.01 U
0.03 U
0.004 UJ
7.4
0.02
0.05 U
0.60 U
0.2 U
0.02 UJ
0.005 U
1.0 U
0.1 U
7.6 UJ
0.2 U
149
0.9
148
1.0 U
IU
7U
4.5
7.80
IU
7U
IU
2U
Disposal Site Lawrenccburg, Tennessee
MYV-15A
15A-2
12/4/90
FPR
-
IU
5U
IU
2U
MW-15B
1SB-2
12/2,3/90
FPF
0.0002
63 U
0.01 U
0.01 U
0.15 U
0.004 U
1.7
0.01 U
0.05 U
2.3
20 J
0.02 U
0.005 U
73
0.1 U
10U
0.2 UJ
100
62 U
23 U
14 U
2
243 U
1.0 U
10.48
IU
9U
IU
2U
MW-16A
16A-2
12/1/90
FPR
0.0085
84
0.03
0.01 U
2.0 U
0.004
11
7.3
2.5
6.2
70 J
0.54 U
0.005 U
SI
0.1 U
280 J
0.2 UJ
108
IU
108
1.0 U
3
133 UJ
49
6.64
6.51
3
8U
IU
5
MW-16B
160-2
12/2.3/90
FPF
0.0008
95
0.01 U
0.01 U
0.53 U
0.004 UJ
47
0.04
0.05 U
30
340 J
0.02 U
0.01 U
10
41
709
0.2 UJ
108
IU
IU
3.88
126 U
1.0 U
11.88
IU
5U
IU
2U
MW-17A
17A-2
12/3,4/90
FPR
0.0029
6.3 U
0.01 U
0.01 U
3.9
0.018
5.4
4.6
0.13
1.6
2.3 UJ
0.42 U
0.005 U
0.2 U
136
0:3
136
1.0 U
4
7UJ
10
7.43
7.39
IU
5U
IU
2U
Page 3 of 3
MVV-17A
I7A-2-F*
12/5/90
FPR
0.0003
41 U
0.01 U
0.03 U
0.(KM U
3.2
0.01 U
0.05 U
0.93
8.2 J
0.02 U
'
MW-I7B
1711-2
12/5/VO
FPF
0.(M)65
340
0.01 U
0.01 U
1.90U
0.004 UR
123
0.24
0.05 I)
5.7
580 J
0.02 U
1 U
5U
1 U
2U
NOTE: All concentrations reported in pans per million unleii noted otherwise.
ppb- paru per billion
OL Ordovician Limestone
r-TF- Fort Payne Formation
FPR Fort Payne Residuum
Parameter not analyzed fur in Ihis sample.
Filmed Sample t Duplicate Sample
U - The parameter was analyzed for, but was not detected.
The associated numerical value Is the sample quantiuiion limit.
J - The associated numerical value is an estimated quantity.
UJ - The parameter was analyzed for, but was not detected.
The sample quantilalion limit is an estimated quantity.
R 'Hie data arc unusuable (compound may or may not be present).
Resampling and icanatysis is necessary fot verification.
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V. SUMMARY OF SITE RISKS
Surficial on-site soils and surface water of the streams around
the site and Shoal Creek were considered to have current,
potentially complete exposure pathways. Future potentially
complete exposure pathways include surficial and subsurface
soils, surface water of the streams around the Site . (including
Shoal Creek), and ground water. The risk assessment was
performed as part of the RI for the matrices listed above and can
be found in the RI report with an EPA addendum in the FS report.
A^ SELECTION OF CONTAMINANTS OF POTENTIAL CONCERN
The hazard identification involved the selection of contaminants
of potential concern (COPCs), detected contaminants which have
inherent toxic or carcinogenic effects that are likely to pose
the greatest concern with respect to the protection of public
health and the environment. Selected contaminants of concern
which were found to drive the Risk Assessment (or account for
approximately 90% of the risk) at the Murray Site include:
* Nickel
* Chromium III
* Chromium VI
Delineation of all COPCs for each media can be found in Table 5-1
of this document. Monitoring data from the RI report were used
to calculate exposure concentrations for the exposure scenarios
described below.
B. EXPOSURE ASSESSMENT
The objective of the exposure assessment is to estimate the type
and magnitude of exposures to the chemicals of potential concern
that are present at or migrating from the Site. The results of
the exposure assessment are combined with chemical-specific
toxicity and carcinogenicity information to characterize
potential risks.
Populations at greatest risk of health effects are those who
would potentially use on-Site ground water and children who would
play in surficial soils in the overland flow area on-Site. The
primary routes of exposure to contaminants in the ground water
are ingestion of the water, inhalation of volatiles and dermal
absorption. The primary route of exposure for children playing
in surficial soils of the overland flow area is ingestion.
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Rcooixt of Dcds&ofi
Section V
Pope 2
Exposure Point Concentrations
Exposure point concentrations were calculated for ground water,
surface water, sediment, ground-water seeps and surficial soils.
The reasonable maximum exposure (RME) point concentration was
calculated after testing the data's distribution. The 95% Upper
Confidence Limit (UCL) on the arithmetic mean was calculated for
each COC in each area. The RME was the lower of the 95% UCL or
the maximum detected concentration.
Table 5-2 of this document contains the exposure point
concentrations, or the UCLs, for each of the driving contaminants
in each media tested. Ground water, surface water and sediment,
seep soil and water, soil (surficial and subsurface) and surface
water data from the RI Report were used to derive exposure point
concentrations. The RI Report contains data for samples taken
for the contaminants of concern for the time frames and locations
discussed for each media in Section III of this document.
Some of the analytical results are reported as "non-detects",
meaning the actual concentration of the contaminant analyzed for
is between zero and the detection limit. The risk assessment
calculations were based on assuming that all non-detect samples
were contaminated at a concentration equal to the detection
limit. This makes the risk assessment more conservative.
Exposure Dose Calculations
Average daily exposure doses (ExDs) were calculated for each
exposure pathway using standard assumptions in EPA Risk
Assessment guidance. Exposure scenarios and calculations with
assumptions will be summarized below. For cancer effects, doses
were averaged over a lifetime (70 years); doses for non-cancer
effects were averaged over the exposure period CU.S. EPA 1989a).
Current Exposure
1. wading
Current wading exposure doses (WExDs) for a child (6 to 15 years
of age) to surface water and sediment in Northeast, Southeast,
and Southwest Branches and on-Site ground-water seeps were
calculated using the following assumptions:
a. a 38-kg body weight (U.S. EPA, 1989c);
b. a skin surface area of 4,100 sq. cm in contact with
affected media (i.e., hands, feet, lower arms, and
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Record of Decision
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Page 3
lower legs);
c. a sediment or soil adherence rate of 1.0 mg/cm2 (U.S.
EPA, 1992b);
d. an incidental sediment ingestion rate of 50 mg/day or
one-half the rate for soil (U.S. EPA 1991a);
e. standard EPA bioavailability adjustment factors and
permeability constants for dermal absorption of
contaminants from water and soils, respectively;
f. an exposure frequency of 50 days/year for 10 years,
which is similar to EPA Region IVs recommended
exposure frequency of 45 days/year of swimming (U.S.
EPA, 1991b);
g. an exposure duration of 2.6 hours per day wading in the
branches, which equals the standard default value for
swimming, and one hour per day playing in the seeps;
and
h. an averaging period for children and adults of 25,550
days for cancer risk (365 days for 70 years) and 3,650
days (365 days for 10 years) for hazard quotients.
Example calculations for this scenario are shown in Table 5.3.
For a child trespasser exposed to surface water and sediment, the
excess lifetime cancer risk (ELCR) was found to be 1 x 10~-9.
The hazard index (HI) was found to be 0.3. For a child
trespasser exposed to water and soil in ground-water seeps, the
ELCR was 1 x 10 ~-6 and the HI was 0.3 here as well. All
computed risk values for the wading scenario are within EPA
guidelines.
2. Swimming
Using a similar approach to that described for wading,
calculations were made for swimming exposure in Northeast,
Southeast and Southwest Branches. Numerical results of
calculations will be revealed in the Risk Characterization
portion of this section. All swimming exposures were found to be
acceptable.
3. Fish Ingestion
While it is unlikely that fish would be caught and consumed from
the branches, calculations were performed for them, as opposed to
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tf array Ohio Dump JVPL Site
Rcoofu oj Decision
Section V
Shoal Creek (a more likely scenario since it is a larger stream)
to obtain a more concentrated, conservative scenario. Exposure
doses were calculated for consumption of fish caught locally in
Shoal Creek based on data from Northeast, Southeast, and
Southwest Branches and the following assumptions:
a. hypothetical concentrations of contaminants in the fish
were calculated using the 95% UCL concentrations
detected from the three branches times the fish
bioconcentration factor (BCF); and
b. ingestion of an average of 54 grams of fish per day
(U.S. EPA, 1991a).
Body weight and averaging times were the same for the other
scenarios previously presented.
4. Soils
Surficial soil exposure doses were estimated for children (6 to
15 years of age) trespassing on the Site. Specific guidance is
not currently available for this non-residential type of
scenario. Thus, exposure doses were calculated based on body
weights and averaging times presented previously and the
following assumptions:
a. a breathing rate of 2 cubic meters/hour which assumes
moderate activity (U.S. EPA, 1989c);
b. a dust adherence of 1 mg/cm2 (U.S. EPA, 1992b) ;
c,. a skin surface area of 3,100 cm2 (hands, face and arms,
U.S. EPA, 1989O;
d. a soil ingestion rate of 100 mg/day (U.S. EPA, 1989a);
and
e. an exposure frequency of 50 days/year for 10 years.
Future Exposure
Data from both the unconsolidated and Fort Payne bedrock zones of
the upper aquifer were used to estimate exposure to ground-water
contaminants and soil data to a depth of 16 feet. Exposure
scenarios assumed a future resident and included ingestion of
ground water, inhalation of VOCs during domestic use of the
water, dermal contact with ground water while bathing and
ingestion of soil. As with Current Exposures, results of
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Section V
Page S
calculations are presented in the Risk Characterization portion
of this section.
1. Potable Ground Water
Average daily drinking-water exposure doses for future ingestion
of ground water from a hypothetical potable well installed at the
disposal site were calculated based on the body weights and
averaging times previously presented and the following
assumptions:
a. ingestion of 2 liters of water/day for 30 years (U.S.
EPA 1989a); and
b. the ground water in the potable well is from both the
unconsolidated as well as the Fort Payne bedrock zones.
2. Showering
Exposure doses for inhalation of VOCs released from tap water
during indoor activities (showering, dishwashing) are based on
models presented in Foster and Chrostowski (1987) and McKone
(1987). McKone's study indicated that inhalation exposure in the
shower was approximately equal to inhalation exposure from all
other household sources. Inhalation exposure while in the shower
was based on the Foster and Chrostowski model. The shower
exposure dose for each contaminant was doubled to derive a total
household inhalation exposure dose estimate. Assumptions used
are similar to those previously presented.
3. Soil Exposure Due to Residential Construction
Future residential development of the Site would require
excavation and regrading; thus, all soil data to a depth of 16
feet were selected to represent future surficial soil
concentrations. Ingestion was the only exposure pathway
considered for future residents in the excavation/construction
scenario. This is consistent with current EPA guidance (1991d).
Dermal and inhalation pathways were considered minor because
lawns and the generally undisturbed nature of residential
property limit these exposure routes. Furthermore, VOCs would
not persist in surficial soil, and inorganics are not well
absorbed across the skin. Therefore, the standard soil ingestion
assumptions should provide a reasonably conservative estimate of
future residential exposure to soil.
Exposure of a future resident considered exposure as a child and
adult over a 30-year residence time. Body weights and soil
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ingestion rates differ with age; therefore, an age-adjusted soil
ingestion factor of 114 mg-yr/kg-day and an exposure frequency of
350 days per year were used to calculate exposure (U.S. EPA, 1991
a and d).
4. Soil Exposure for a Child Resident in Overland Flow and
Formerly Ponded Areas
This portion of the Risk Assessment was performed by EPA after
the previously presented parts since additional sampling of the
Overland Flow and Formerly Ponded areas was required subsequent
to the RI. Additional sampling was required due to very high
soil concentrations found in these areas. Calculations for this
scenario are presented in the EPA addendum to the FS.
This scenario assumed a future child resident playing in the
Overland Flow and Formerly Ponded Areas and ingesting, dermally
absorbing and/or inhaling soil contaminants. EPA's Regional
Toxicologist performed this portion of the Risk Assessment and
assumed all current EPA values for exposure^in these three
avenues. Refer to this part .of the FS for a'll information on
these values and assumptions. Exposure point concentrations can
be found in Table 5.2 herein.
Exposure to Lead
The current approach to assessing the toxicity of lead is based
on potential effects seen in children as predicted by the Uptake
Biokinetic Model for lead. The model estimates blood lead levels
which are then compared to the acceptable level of 10
micrograms/deciliter. .
This model is a program that estimates total lead uptake
[micrograms (ug) lead/day] in humans which results from diet,
inhalation and ingestion of soil, dust, water, painting, and
placental transport to the fetus. The current program calculates
lead uptake and blood lead levels for the most sensitive
subpopulation, children aged 0 to 6 years. This would be a
hypothetical future exposure scenario where children in this age
group visit the Site or are on-Site residents. Table 5.4
summarizes the results from this model.
C. TQXICITY ASSESSMENT
Under current EPA guidelines, the likelihood of carcinogenic and
non-carcinogenic effects due to exposure to Site chemicals are
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considered separately. Criteria for evaluating the potential of
Site chemicals to cause these two types of adverse effects are
described below.
Criteria for Non-Carcinocrenic Effects
The Reference Dose (RfD) is an estimate of the highest human
intake of a chemical, expressed as mg/kg/day, that does not cause
adverse effects when exposure is long-term (lifetime). RfD
values are based on animal or human toxicity studies from which a
no-observed-adverse-effect level (NOAEL) is experimentally
determined. The NOAEL is the highest dose at which there was no
statistically or biologically significant adverse effect
observed. The RfD is derived by dividing the NOAEL from the
selected study by an uncertainty factor. The uncertainty factor
consists of multiples of 10 to account for specific areas of
uncertainty in the available data.
The dose calculated from the exposure assessment is compared to
the RfD to determine whether adverse effects might occur. If
predicted exposure concentrations are below the level of the RfD,
no adverse health effects are expected according to current EPA
guidelines.
The oral RfD for nickel is 2 X lO'^g/kg/day, which is calculated
using an uncertainty factor of 300. Total Chromium and Chromium
VI have RfDs of 1 X 10° and 5 X 10*3, respectively, with
corresponding 1000 and 500 uncertainty factors.
Nickel's chronic RfD was derived from a rat subchronic study in
which the subjects exhibited substantial weight loss. Chromium's
RfDs were based on NOAELs. Dermal RfDs were developed by
adjusting oral RfDs by the oral absorption factors presented in
ATSDR's toxicological profiles.
Criteria for Carcinogenic Effects
EPA uses a weight-of-evidence system to convey how likely a
chemical is to be a human carcinogen, based on epidemiological
studies, animal studies, and other supportive data. The
classification system of EPA for characterization of the overall
weight of evidence of carcinogenicity includes: Group A - Human
Carcinogen; Group B - Probable Human Carcinogen; Group C -
Possible Human Carcinogen; Group D - Not Classifiable as to
Human Carcinogencity; Group E Evidence of Non-Carcinogenicity
for Humans. Group B is subdivided into two groups: Group Bl -
limited human evidence for carcinogenicity; and Group B2 -
sufficient data in animals, but inadequate or no evidence in
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Record of Decision
Section V
^ Page 8
humans.
EPA's weight-of-evidence classification for nickel is B2 and is
based on effects from exposure to refinery dust. The use of this
chemical's carcinogenic toxicity value in this analysis is
therefore conservative. The classification for Chromium VI is
also B2.
For chemicals with carcinogenic effects, EPA calculates the
cancer risk associated with a given dose by multiplying the dose
from a given route of exposure by a cancer potency factor or
potency'slope. EPA derives potency factors from the upper 95%
confidence limit of the slope of the extrapolated dose-response
curve, which shows the relationship between a given dose and the
associated tumor incidence. As a result, the predicted cancer
risk is an upper-bound estimate of the potential risk associated
with exposure. The inhalation CSFs for Nickel and Chromium VI
are 8.4 X 10"1 and 4.1 X 10"1, respectively. There are currently
no oral CSFs for any of the COPCs.
EK_ RISK CHARACTERIZATION
The risks for each of the scenarios presented in the exposure
assessment are be quantified in this section and can be found in
Table 5.5. The table summarizes all of the added lifetime risks
for each scenario, with the exception of the "Soil Exposure for a
Child Resident in Overland Flow and Formerly Ponded Areas". With
the exception of this scenario, the HI for a future resident is
at 4.0, above the EPA allowable limit of 1.0. This risk for a
future resident is mostly all due to ground water ingestion.
Potable ground water for future potential residents presents a
scenario which will require remediation.
Tables 5.6 and 5.7, respectively, give the cancer and non-cancer
risks associated with the Overland Flow Area. Cancer risks are
acceptable, however, the hazard index for a future child resident
playing in soils in the area is 2.28. This area will require
remediation to bring nickel levels down to permissible
concentrations in the soil, as nickel is the contaminant mainly
responsible for the unacceptable HI.
JL_ ENVIRONMENTAL RISKS
Endangered Species and Critical Habitats
The Tennessee Department of Environment and Conservation (TDEC)
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Record, of Decision
Section V
Page 9
has identified a critical habitat for the slackwater darter
(Etheostoma boschundi) in both Lawrence and Wayne Counties,
however, this critical habitat does not occur downstream of the
Site. In addition, the U.S. Department of Interior, Fish and
Wildlife Service has expressed concern for the federally-listed
endangered gray bat (Mvotis grisescens) for the area around
Lawrenceburg. A gray bat was collected in the Lawrenceburg on
April 28, 1969, by Tennessee Valley Authority researchers.
No priority hibernation, maternity, or bachelor caves for the
gray bat have been identified in either Lawrence County Tennessee
or adjacent Giles County. There is, however, one priority cave
(Ice Cave) and another cave (Lay Cave) documented to be used by
the gray bat for hibernation purposes. Each of these caves is
approximately 35 to 40 kilometers (22 to 25 miles) from the Site.
Given that foraging ranges for the gray bat are from an average
of 11 kilometers (6.8 miles) to a maximum of 17 to 20 kilometers
(10.5 to 12 miles) from a roost cave (La Val et. al.), it is
highly unlikely that gray bats potentially occupying Ice Cave or
Lay Cave would frequent the Site.
A cave used by bats, other than gray bats, is known to exist
around the Murray Ohio Dump Site. The cave is approximately 400
meters (1/4 mile) down the gravel road past the background
monitoring wells (MW-17A and MW-17B). Gray bats will not
cohabitate with other bat species in the same cave; therefore,
the presence of other bat species precludes use of this cave at
this time by gray bats.
A threatened or endangered species survey was conducted by
CDM/FPC for EPA in November 1991 as part of the RI and found no
threatened or endangered species. A copy of this report can be
found in Appendix B of the RI report.
Aquatic Effects
Northeast Branch receives most of the Site runoff before entering
Shoal Creek. Northeast Branch is a shallow (6 to 12 inches deep)
seasonal stream which is not expected to support a complex
aquatic ecosystem. Southeast Branch and Southwest Branch are
even more shallow and seasonal than Northeast Branch. Figure 4.1
shows the location of these streams in relation to the Site.
Surface water and sediment samples were collected from these
streams by Geraghty & Miller, Inc. and CDM/FPC as part of the RI.
Additional samples were collected by EPA's Environmental Services
Division (BSD).
Samples revealed elevated levels of nickel, hexavalent chromium
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Section V
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(mostly in water) and total chromium (mostly in sediment). These
levels were at their highest at the head of Northeast Branch
adjacent to the landfill and decreased to background at the
confluence with Shoal Creek. Chemistry samples from Southeast
Branch and Southwest Branch revealed no unacceptable levels.
Chromium was the primary contaminant detected. Its toxicity to
biota is significantly influenced by abiotic variables such as
Ph, temperature, and hardness of water and biological factors
such as species, life stage and sensitive populations. Chronic
(28 to 84 days) lethal concentrations for 50 percent of the
population tested (LC50s) for freshwater organisms most sensitive
to chromium VI have been reported from 0.2 to 0.5 mg/1 (Eisler
1986) . The maximum and average concentrations detected in
Northeast Branch exceeded the chronic criterion for chromium VI,
but did not exceed the criterion for chromium III. Again,
concentrations are diluted to background at the entrance to Shoal
Creek.
The National Oceanic and Atmospheric Administration (NOAA) has
established values for screening sediment contaminant
concentrations with respect to potential biological effects.
These values are not standards or criteria. NOAA Effects Range-
Low (ER-L) and Effects Range-Median (ER-M) values were used for
comparison with the detected levels of contaminants in sediment.
ER-L values are concentrations equivalent to the lower 10
percentile of NOAA screened available data and indicate the low
end of the range of concentrations in which adverse biological
effects were observed or predicted in sensitive species and/or
sensitive life stages. ER-M values are the 50th percentile
concentrations in ranges of screened data; above these
concentrations, adverse effects were observed or predicted for
most species tested.
Nickel exceeded the ER-M value at Northeast Branch locations
nearest the Site. The maximum sediment concentration of nickel
detected in Southeast Branch of 64 mg/kg exceeded the sediment
background level (30 mg/kg) as well as the NOAA ER-M value of 50
mg/kg. Chromium exceeded the ER-L value but not the ER-M value.
Biological testing was conducted by BSD to assess current ambient
conditions and ecological integrity of the tributaries draining
the Site and feeding into Shoal Creek. These tests were designed
for a tiered approach and included habitat assessment, surface-
water and sediment toxicity testing and benthic macroinvertebrate
biosurvey. This study is contained in Appendix A of the RI
report.
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Record fy Occisioft
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Data for surface water and sediment chromium and nickel
concentrations, acute toxicity tests, and benthic
macroinvertebrate survey indicate that the Site exerts an impact
on the upper reaches of Northeast Branch. However, the impact to
the aquatic community is restricted in areal extent. There is no
indication of metal contamination or aquatic toxicity where
Northeast Branch drains into Shoal Creek. The toxicity of water
diminishes and disappears as Northeast Branch reaches Shoal
Creek. Some places along Southeast Branch show toxicity to
biota. Although toxicity samples were not collected from
Southwest Branch in the proximity of the Site drainage, current
data (i.e., habitat assessment, bioassessment score) indicate
that the Site exhibits no impact to this branch.
Elevated levels of nickel and chromium detected in surface water
and sediment of Northeast Branch (and sporadically along
Southeast Branch) decreased to acceptable levels as the tributary
approached Shoal Creek. There is no indication of elevated
contaminant concentration in Southwest Branch. Chromium and
nickel may be migrating from the Site to Northeast Branch and
Southeast Branch from erosion and ground-waner transport.
Concentrations of chromium and nickel may be' affecting biota in
Northeast Branch and Southeast Branch, but are not likely
affecting populations in Shoal Creek.
Terrestrial Effects
The results of the CDM/FPC terrestrial habitat survey are
presented in Appendix B of the RI report. In summary, the only
significant contaminants posing risk were chromium and nickel.
The current landfill cover does lessen threats to the terrestrial
environment, but not to an acceptable level. The chance of
exposure to contaminants is increased in the 1973 area due to
inadequate cover thickness. Likewise, high levels of nickel and
chromium in the surficial soils of the overland flow and formerly
ponded areas present a threat to terrestrial receptors.
F\_ UNCERTAINTIES
All estimates of risk are based upon numerous assumptions with
uncertainties. In addition to limitations associated with Site-
specific chemical data, other assumptions and uncertainties that
affect the accuracy of the Site-specific risk characterizations
result from the extrapolation of potential adverse human health
effects from animal studies, the extrapolation of effects
observed at high-dose to low-dose effects, the modelling of dose
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response effects, and route-to-route extrapolation.
The use of acceptable levels (established standards, criteria and
guidelines) and unit cancer risk values which are derived from
animal studies introduces uncertainty into the risk estimates.
In addition, the exposure assumptions used in estimating
individual dose levels are often surrounded by uncertainties. As
such, these estimates should not stand alone from the various
assumptions and uncertainties upon which they are based. In
developing numerical indices of risk, an attempt is made to
evaluate the effect of the assumptions and limitations on the
numerical estimates.
The uncertainty factors which are incorporated into the risk
estimates are believed to be conservative. As such, when they
are considered collectively, exposure and subsequently risk may
be overestimated. On the other hand, these risk calculations
were based on present conditions at the Site, including present
concentrations of contaminants in the various Site media.
Additional risk could occur should the concentrations increase in
any of the Site media.
G. CONCLUSIONS
Hazard Indices were unacceptable for a future resident ingesting
ground water at the Site and for a child playing in and ingesting
soils from the Overland Flow Area. These His were 4.0 and 2.3,
respectively and were due almost entirely to nickel, chromium and
hexavalent chromium. All other scenarios presented in the
Exposure Assessment and Risk Characterization portions of this
section were found to be acceptable for cancer as well as non-
cancer risks. A summary of the cancer as well as non-cancer risk
numbers for each scenario can be found in Tables 5.5, 5.6 and
5.7.
Recommended remediation numbers are to those ground-water ARARs
specified in Section VII of this document and the following
surficial soil numbers for the driving contaminants, as
calculated by EPA's Regional toxicologist:
Nickel - 1,498 ppm
Chromium(6) - 374 ppm
Total Chromium - 74,881 ppm
Off-Site soils meet the approved action delineation levels for
Nickel, Chromium(S), and Total Chromium.
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Hurray Ohio Dump NPL Site
Record of Decision
Section V
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Data for surface water and sediment chromium and nickel
concentrations, acute toxicity tests, and benthic
macroinvertebrate survey indicate that the Site exerts an impact
on the upper reaches of Northeast Branch. No other streams
around the Site show impacts with the exception of some mild
impacts to Southeast Branch. No further ecological sampling in
the tiered approach is necessary at this time. High metal
concentrations in the surficial soils of the overland Flow Area,
in addition to presenting a human health risk, could pose risks
to the terrestrial environment.
Actual or threatened releases of hazardous substances from this
Site, if not addressed by implementing the response actions in
this ROD, may present an imminent and substantial endangerment to
public health, welfare and the environment.
-------
lc 5-..1 .^Contaminants of Potential Concern1;1
Disposal Site, Lawrenceburg Tennessee.
I'il-JC I Hi .'
Contaminants
INORGANICS
Arsenic
Uarium
Herylliuin
Cadmium
C'hromiiini
Cohall
Copper
Cyanide:
Iron
Lead
Manganese
Mercury
Nickel
Nitrate
Vanadium
Zinc
OUCANICS
Ground Waler Ground-Water Seeps
Fort Payne
Unconsoliduled Zone Bedrock Zone Surface Waler Sediment Seep Waler Seep Soil
XX X
X
x ~"~ x
x x x x x x
x x
x
xx xx
'*
XXX X
X X X X
X
X' X X X X
X X
(x)
XX X X
.
Soil
0-6 (eel
(x)
(x)
X
X
X
X
X
X
(x)
X
0-16 leel
(.v)
(x)
x
x
x
x
x
X
X
X
(x)
X
VOCs
Acetone
Itcnzcne
2-Bnlanone
1,2-Dicliloroellione
Lihylhenzene
4-Methyl-2-peulanone
Toluene
Tricliloroelhene
X'ylenes
x
x
X
X
X
X
Footnotes appear on page 2.
-------
5-15
Contaminants of P3t«utlal> concern, Murray Ohio Disposal Site, Lawrenceburg Tennessee.
Ground Water
Ground-Water Seeps
Uncoiisolidufcd Zone
Fort Puyne
Bedrock Zone
Soil
Surface Water Sediment Seep Water Seep Suit 0-6 feel 0-16 led
bi-iui-VOCs
Fluoranlhene
I'yrene
I'lJSTICIDliS
g;inima-BHC
Emlosulfaii I
\
(x)
x
Contaminant of concern.
Retained in exposure calculations, but not likely a contaminant of concern based on background concentrations.
Constituent is included as a COC because it was detected in a ground-water seep.
-------
Page 5-16
TABLE 5.2
EXPOSURE POINT CONCENTRATIONS FOR DRIVING COGS BY MEDIA
Page 1 of 2
GROUND WATER
Dnconsolidated Zone
Contaminant DCL (mg/1)
Chromium (total) 0.022
Chromium VI 0.068
Nickel 0.99
Fort Payne Bedrock Zone
Contaminant DCL (mg/1)
Chromium (total) 0.76
Chromium VI 0.97
Nickel
Unconsolidated and Fort Payne Bedrock Zones
Contaminant DCL (mg/1)
Chromium (total) 0.39
Chromium VI 0.48
Nickel 0.46
SUBSURFACE SOILS
Contaminant DCL (mg/kg)
Chromium (total) 93
Nickel 180
SURFICIAL SOILS EXCLUDING OVERLAND FLOW AND FORMERLY PONDED AREAS
Contaminant DCL (mg/kg)
Chromium 62
Nickel 120
SDRFICIAL SOILS FROM OVERLAND FLOW AREA
Contaminant DCL (mg/kg)
Total Chromium 1290
Chromium VI 0.358
Nickel 3390
SURFICIAL SOILS FROM FORMERLY PONDED AREAS
Contaminant DCL (mg/kg)
Total Chromium 70.1
Chromium VI NA
Nickel 96
-------
Page 5-17
TABLE 5.2 (continued)
EXPOSURE POINT CONCENTRATIONS FOR DRIVING COGS BY MEDIA
Contaminant
Chromium
Nickel
Page 2 of 2
SURFACE WATER
UCL (mg/1)
0.041
0.047
SEEP WATER
Contaminant
Chromium (total)
Chromium VI
Nickel
UCL (mg/1)
1.0
1.3
1.9
SEEP SOIL
Chromium (total)
Nickel
UCL (mg/kg)
830
670
Contaminant
Chromium (total)
Nickel
SEDIMENT
UCL (mg/kg)
110
580
-------
rage D-
Table 5.3 Equations and Example Calculations, Current Wading Exposure Doses to Surface
Water, Sediments, and Ground-Water Seeps, Murray Ohio Disposal Site,
Lawrenceburg, Tennessee.
Equation Definitions
WEXD = Cc^ x rfiRi + (SSA x SA x BAFYI x EF
BW x AP x UCl sediment
WExD = C^ x SSA x PC x ED x EF
BW x AP x UC2 surface water
where:
WExD Average daily wading exposure dose (mg/kg/day).
AP Averaging period (25,550 days/lifetime [70 years] for carcinogens; 3,650 days
[10 years] for non-cancer effects) (USEPA, 1989a; 1991a,c).
BAF Bioavailability adjustment factor (unitless) (Table 7-11).
BW Body weight (38-kg) (USEPA, 1989c).
C^ Constituent concentration in sediment (mg/kg). ,
Cw Constituent concentration in surface water (mg/L).
ED Exposure duration (2.6 hours/day for streams and 1 hour per day for seeps)
(USEPA, 1991a).
EF Exposure frequency (50 days/year x 10 years).
IR Ingestion rate (50 rng/day).
PC Permeability constant (cm/hr) (Table 7-11).
SA Sediment adherence (1 mg/cm2/day) (USEPA, 1992b).
SSA Skin surface area in contact with affected media (4,100 cm2 - child) (USEPA,
1989c).
UC 1 Unit conversion ( 1 ,000,000 mg/kg) .
UC2 Unit conversion (1,000 cmVL).
mg/kg Milligrams/kilogram.
mg/L Milligrams/liter.
cm/hr Centimeters/hour.
Example calculations (Total chromium in Seeps)
WExD.4 = 830 mp/kg x f(50 mg/dav^ + (4.100 cm2 x 1 mg/cm2/dav x 0.211 x 500 davs
38 kg x 3,650 days x 1,000,000 mg/kg
= 2.6E-03 mg/kg/day (soil)
WExD,, = 1 mp/L x 4.100 cm2 x 0.001 cm/hr x 1 hr/dav x 500 davs
38 kg x 3,650 days x 1,000 cm3/L
= 1.5E-05 mg/kg/day (water)
-------
Page 5-19
Table 5,4 Blood Lead Levels in Children (Aged 0 to 6), Murray Ohio Disposal Site, Liwrenceburg, Tenn
Source Area
Medium
Blood 1 faii Levels'
Lead Cooceotnuioa
Geometric Mean
pg/dL
Percent Below
10 pg/dL
Unconsolidated Zi
and Bedrock Zone
SurficialSol
Ground Water 16 /ig/L
Soil/Dust
Air"
35 mg/kg
0.0026
2.47*
100*
a CalcoUted using the USEPA LeadS model (USEPA, 199 le).
b Calculated value. C^ = SPM mg/m5 x C, mg/kg x 10"* kg/mg x 10* pg/mg; where SPM is the
fraction of suspended particuUte matter in mg/m1 from soil (Federal Register. 1988).
* Sum of all the sources together.
/ig/dL Micrognms per deciliter.
/ig/L Micrognms per liter.
pg/m3 Micrognms per cubic meter.
mg/kg Milligrams per kilogram.
-------
Page 5-20
Table 5.5 Total Site Risk
Murray Ohio Disposal Site Lawrenceburg, Tennessee.
Cancer Effects
Adult Child
Current Risks
Wading
Branches NA 1 x Itf9
Ground- Water Seeps NA 1 x 10*
Swimming NA NA
Fish Ingestion NA NA
Surficial Soil NA 1 x 1O6
Total NA 2 x 10-*
Future Residential Risks
Ground Water
Ingestion 5 x 10-7 NC
Inhalation 4 x 10"7 NC
Dermal Contact 1 x 10"* NC
Soil 2 x ID"5
Total 2 x ID'5
Non -Cancer
Adult
NA
NA
0.1
0.3
NA
0.4
3.8
0.0009
0.1
0.39
4
Effects
Child
0.27
0.33
0.1
0.5
0.25
1
NC
NC
NC
-
NA Not applicable.
NC Not calculated, future exposure based on 30-year residency.
* Included in adult risk estimate.
-------
Page 5-21
Table 5.6 EMM ltfetis*C«nwW*A»odttod with Bcpo«« to Surface SoflU^
\
Chemksls
Total Chramon
Cteoatan(6)
Nk*r1
Tottta
Old
laftrtta
LBCR
NC
NC
NC
NC
and
Derail
LECK
NC
NC
NC
!NC
GhBd
Inhalation
LECR
NC
Z78E-09
SJ9E47
5.42&07
S.39&07 |
Table 5.7 H«nrtladlc««A»oditedwtlhExpoiur«toSartuceSo&tUnderFuttrt&tpoareSceuriM
.
Quaalaig
ToolOiremitm
Oration (6)
Nickel
Tool*
ChM
iBfcftioo
Do^RID
Bftlff
041720000
0^)0095467
""MMOOOO
Z27S15467
Ch&d
Dermal
DOM/HID
Ratio
0.00002726
0.00000151
OJW358210
040361088
Chfld
Tnhit.H/^
DoM/UC
Ratio
NC
NC
NC
NC
Z282 I
*NC - Not calculated due to some of the components in the mathematical formula
being zero.
-------
Hurray Ohio Dump NPL Site
Record of Decision
Section VI
Page I
VI. DESCRIPTION OF REMEDIAL ALTERNATIVES
In the previous section of this document, several risk scenarios
were developed. The two unacceptable ones were that of a future
resident ingesting ground water from beneath the Site and that of
a child resident ingesting soils from the Overland Flow Area.
A total of eight alternatives were evaluated for remediating
ground water and soil at the Site. With the exception of
Alternative 1 which involves no action, the other seven
alternatives involve different degrees of capping at the Site,
some in conjunction with seep collection and treatment or ground-
water extraction and treatment. The alternatives are as follows:
Alternative 1; No Action
The National Contingency Plan requires the development of a no
action alternative as a basis for comparison of alternatives.
Therefore, Remedial Alternative 1 consists of implementing no
remedial action at the Site, including no restriction on future
installation of potable ground-water wells, deed restrictions, or
institutional controls such as fencing. Maintaining the existing
cover system would be discontinued.
There is no present worth cost or implementation time associated
with this remedial alternative since no action would be taken and
the Site would remain in its present condition.
Alternative 2; Current Site Conditions with Remediation
Performed to Date, Upgrades, and Continued Maintenance of
Containment Systems
Remedial Alternative 2 includes current Site conditions with
remediation performed to date and upgrades to promote and
continue maintenance of the containment systems. The existing
cover system would be maintained over the pre- and post-1973
disposal areas and a durable cover would be constructed over the
1973 disposal area. Deed restrictions are currently in place for
the property to restrict the use of ground water and land use.
1. Landfill Contents
Landfill contents would be maintained under Remedial Alternative
2 by maintaining the existing cover system over the pre- and
post-1973 disposal areas and constructing a durable surface cover
over the 1973 disposal area. The durable surface cover would
provide a road surface for vehicular access to the City of
-------
Murray Ohio Dump NPL Site
Record of Decision
Section V7
Pages
Lawrenceburg Sanitary Landfill. Infiltration of precipitation
through the landfill contents would be reduced by installing and
maintaining the cover systems. Restrictions would be noted in
the deed for the Murray Ohio Dump Site.
Slope stabilization of the eastern lobe of the post-1973 disposal
area would reduce erosion and prevent slope failure of the final
cover. A concrete retaining wall approximately 10 feet high
would be constructed against the almost vertical slope. The wall
foundation would be installed above the existing grade to prevent
disturbance of the waste. Slope stabilization would occur prior
to cover system construction.
The existing barrier cover systems over the pre-and post-1973
disposal areas would continue to be maintained. The vegetative
cover on these areas would be mowed regularly on-schedule and
granular lime would continue to be applied (to maintain the Ph of
the soil at 7 or above) to promote vegetative growth, mainly
crown vetch.
A durable surface cover would be constructed over the 1973
disposal area. An access road for the active portions of the
City of Lawrenceburg Sanitary Landfill currently passes over this
former disposal area. The durable surface cover would consist of
a fiber-reinforced concrete cover installed over the existing
access road and would be approximately six inches thick. This
would prevent further erosion of the existing clay cover, protect
the clay cover from vehicular damage, and allow continued access
to the City landfill.
2. Ground Water
Deed restrictions and the Conservation Easement and Restrictive
Covenant for the Site would restrict future development of
ground-water supply wells. These would remain in effect for no
less than 30 years. After 30 years, prohibitions on specific
activities may be terminated upon showing that the prohibition is
no longer necessary to protect humans, animals, or the
environment from exposure to contaminants.
No action would be performed on seeps to collect contaminated
ground water.
3. Surface Water
No action would be performed for surface water.
4. Costs and Time to Implementation
-------
Hurray Ohio Dump NPL Site
Record of Decision
Section VI
Patfe3
The present worth cost of Alternative 2 is $370,000. Although no
exact implementation times are available, EPA estimates the time
required to implement each remedy, from shortest to longest, by
alternative number, is as follows:
#1 < #2 < #3 <#6 <#8 <#4 <#7 <#5
Therefore, Alternative #2 has a fast implementation time.
Because this alternative would result in contaminants remaining
on-Site, CERCLA requires that the Site be reviewed every five
years. If justified by the review, remedial actions would be
implemented at that time to remove or treat contamination.
Remedial Alternative 3t More Elaborate Upgrades with Storm-water
Management Controls and Additional Institutional Controls and
Deed Restrictions
Remedial Alternative 3 represents more elaborate upgrades to the
current containment systems. As with Alterative. 2, the existing
cover system over the pre-and post-1973 disposal areas would be
maintained and a durable cover system would be constructed over
the 1973 disposal area.. The additional cover component in this
alternative involves construction of a single barrier cover
system over the Overland Flow Area. Storm-water management
controls would be implemented to reduce run-off and infiltration
of precipitation through the landfill contents. Additional
institutional controls and deed restrictions would also be
employed.
1. Landfill Contents
Remedial Alternative 3 includes maintaining the cover systems,
construction of a durable surface cover on the 1973 disposal
area, and construction of a single barrier cover system on the
Overland Flow Area. Maintenance of the existing covers would
involve mowing and lime application. Mobility of the
contaminants of concern would also be reduced by implementing
storm-water management controls. These controls include
regrading and revegetation of the pre-1973 disposal area and
slope stabilization of the post-1973 disposal area. Slope
stabilization of the eastern portion of the post-1973 disposal
area would be performed as described under Alternative 2.
Regrading and revegetation of the pre-1973 disposal area would
reduce transport of contaminants of concern in two ways. First,
it would eliminate the ponding that currently is increasing
infiltration into the area. Secondly, it would direct storm
-------
Jtf urroy Ohio Dump NFL Site
Record 07 Decision
Section VI
Page 4
water away from the Overland Flow Area, where it is transporting
constituents into Northeast Branch. The single barrier cover
system to be constructed over the Overland Flow Area would reduce
leaching of the contaminants of concern via infiltration of
precipitation through this area. A durable surface cover would
be constructed over the 1973 disposal area, as described in
Alternative 2.
Access restrictions in the form of a perimeter fence around the
disposal areas would be constructed to limit access to the
landfill contents and restrict the direct contact exposure
pathway of would-be trespassers. Previously described deed
restrictions would also be implemented.
2. Ground Water
Deed restrictions would prohibit installation of ground-water
supply wells at the Site and adjacent properties. Additionally/
Site monitoring would be performed at selected wells in the
existing monitor well network at the Site to gauge ground-water
contaminant concentrations. Periodic monitoring under this
alternative would also be performed to confirm the continued
stability of aquifer characteristics. Samples from each well
would be analyzed for TAL metals, TCLs, semi-volatiles, and
general water quality parameters. No action would be performed
on the seeps to collect contaminated ground water.
3. Surface Water
No action would be performed for surface water under this
alternative.
4. Costs and Time to Implement at ion
The present worth cost of Alternative 3 is $1,700,000. Although
no exact implementation times are available, EPA estimates the
time required to implement each remedy, from shortest to longest,
by alternative number, is as follows:
#1 < #2 < #3 <#6 <#8 <#4 <#7 <#5
Therefore, Alternative #3 has a moderately fast implementation
time.
Because this alternative would result in contaminants remaining
on-Site, CERCLA requires that the Site be reviewed every five
years. If justified by the review, remedial actions would be
implemented at that time to remove or treat contamination.
-------
Hurray Ohio Dump NPL Site
Record of Decision
Section VI
PageS
Remedial Alternative 4: Alternative 3 Plus a Subsurface Drain
System for Collecting Ground-Water Seeps, Treatment and Surface-
Water Monitoring
Remedial Alternative 4 involves collection and on-Site -treatment
of the ground-water seep discharges to improve water quality in
the upper reaches of Northeast Branch coupled with maintaining
the cover systems. The collected water would be discharged to
Shoal Creek under an NPDES permit after being treated by chromium
reduction, metals precipitation, coagulation/flocculation, and
gravity clarification.
1. Landfill Contents
Remedial Alternative 4 includes maintaining the cover systems,
construction of a durable surface cover, and construction of a
single barrier cover system as a containment response for the
landfill contents. These containment options for landfill
contents, storm-water management controls, and maintenance
procedures are the same as under Remedial Alternative 3.
2. Ground Water
Remedial Alternative 4 involves collection and on-Site treatment
of ground water and the five seeps along Northeast Branch.
Ground water and the seeps would be collected in a subsurface
trench and piped to a collection point for on-Site treatment. A
trench drain would be installed to collect both the seep
discharge and contributing ground water from the Site that is
baseflow to Northeast Branch. Collected seep and ground-water
discharge would flow to a sump at the lowest collection point and
then be pumped to a treatment system located in the vicinity of
the headwaters.
Treatment of the ground-water and seep discharge would be
accomplished on-Site through chromium reduction, metals
precipitation, coagulation/flocculation and gravity
clarification. After exiting the treatment train, the treated
ground-water and seep discharge would be pumped to a sludge
thickening tank to settle precipitated material and then piped to
a gravity clarifier for additional particulate and solids
removal. The settled sludge would then be collected in a sludge
accumulation tank and transported off-Site for disposal. Prior
to surface water discharge through a transfer pump, the treated
ground water and seep discharge would flow through a polishing
filter to remove any residuals and the flow rate would be
equalized in an accumulation tank.
Improvements to the existing roadway at the Site would be
-------
Hurray Ohio Dump KPL Site
Section VI
Page 6
required to permit tanker truck access for treatment reagent and
residual transport. Approximately 18,000 square feet of wooded
area would have to be cleared, grubbed and regraded to make room
for the treatment system compound and truck turn-around area.
The same sampling actions as those in Alternative 3 would be
employed for ground water, i.e., sampling and analysis would be
performed at selected wells in the existing monitoring well
network at the Site to gauge ground-water contaminant
concentrations and mobility, as well as aquifer characteristics.
3. Surface Hater
Sampling would be conducted on a quarterly basis at SW-007.
Sampling would be for TAL metals. This would mark improvements
to -water quality of Northeast Branch after implementation of
containment measures at the .Site.
4. Costs and Time to Implementation
The present worth cost of Alternative 4 is $4,500,000. Although
no exact implementation times are available, EPA estimates the
time required to implement each remedy, from shortest to longest,
by alternative number, is as follows:
#1 < #2 < #3 <#6 <#8 <#4 <#7 <#5
Therefore, Alternative #4 has an implementation time on the slow
side.
Because this alternative would result in contaminants remaining
on-Site, CERCLA requires that the Site be reviewed every five
years. If justified by the review, remedial actions would be
implemented at that time to remove or treat contamination.
Remedial Alternative 5: Alternative 3 Plus a Vertical Ground-
water Extraction Well Network, Treatment of Ground Water, and
Surface-Water Monitoring
This alternative involves ground-water collection and on-Site
treatment as a means of restoring the ground water for potential
use as drinking water and reducing contaminant transport to seeps
and Northeast Branch. Treatment methods used and sludge disposal
and water discharge options are identical to those described
under Remedial Alternative 4 for ground water and seeps.
1. Landfill Contents
-------
Murray Ohio Dump NPL Site
Record of Decision
Section VT
Page 7
Remedial Alternative 5 includes maintaining the cover systems,
construction of a durable surface cover, and construction .of a
single barrier cover system as a containment response for the
landfill contents. These containment options for landfill
contents, maintenance procedures and storm-water management
controls are the same as those described for Alternatives 3 and
4.
2. Ground Water
Remedial Alternative 5 includes collection and on-Site treatment
of ground water for potential use as drinking water and
addressing the seeps and contaminant transport to Northeast
Branch. Ground-water collection would be accomplished using
vertical extraction wells. Once operating effectively, these
wells would prevent contaminated ground water from moving beyond
the landfill boundary and potentially impacting Northeast Branch.
A target constant extraction flow rate of 45 gallons per minute
is estimated (18 wells at approximately 2.5 gallons per minute
per well) . A high degree of uncertainty exists for the estimated
well yields because these yields are based oh measurements of the
in-situ hydraulic conductivity.
Treatment and discharge of the ground water would be accomplished
using the treatment methods described for the ground water and
seeps under Remedial Alternative 4.
Improvements to the existing roadway at the Site would be
required to permit tanker truck access for treatment reagent and
residual transport. Approximately 18,000 square feet of wooded
area would have to be cleared, grubbed and regraded to make room
for the treatment system compound and truck turn-around area.
3. Surface Water
Sampling would be conducted on a quarterly basis at SW-007.
Sampling would be for TAL metals. This would mark improvements
to water quality of Northeast Branch after implementation of
containment measures at the Site.
4. Costs and Time to Implementation
The present worth cost of Alternative 5 is $7,200,000. Although
no exact implementation times are available, EPA estimates the
time required to implement each remedy, from shortest to longest,
by alternative number, is as follows:
#1 < #2 < #3 <#6 <#8 <#4 <#7 <#5
-------
Murray Ohio Dump NPL Site
Record of Decision
Section VT
Page 8
Alternative #5 has the slowest implementation time of all of the
alternatives.
Because this alternative would result in contaminants remaining
on-Site, CERCLA requires that the Site be reviewed every five
years. If justified by the review, remedial actions would be
implemented at that time to remove or treat contamination.
»
Remedial Alternative 6; Alternative 3 Plus Mai'or Enhancement of
the Existing Cover Over the Pre-1973 Disposal Area
Remedial Alternative 6 involves the same containment options
described in Remedial Alternative 3 with major enhancement of the
existing cover system over the pre-1973 disposal area. This area
appears to be a source of contaminants entering Northeast Branch.
Additional institutional controls and deed restrictions would be
instituted to reduce the potential for direct contact with
landfill contents and restrict the future use options of the Site
and adjacent properties.
1. Landfill Contents
This alternative includes maintaining cover systems over the
disposal areas, upgrading the stormwater management controls,
construction of an enhanced single barrier cover system over the
pre-1973 disposal area, construction of a single barrier cover
system over the Overland Flow Area, and construction of a durable
surface cover over the 1973 disposal area.
For suitable construction of the enhanced single barrier cover
system, the pre-1973 disposal area would be regraded to provide a
minimum slope of approximately 5 percent for positive surface-
water run-off. Approximately 8,300 cubic yards of fill material
would be imported from a borrow source adjacent to the Site so
that disturbance of the existing cover and the wastes would not
be necessary. Upgrading to an enhanced single barrier cover
system over this disposal area would provide further protection
to human health and the environment by blocking potential
exposure pathways and reducing infiltration into the landfill
contents.
As described in Remedial Alternative 3, a durable surface cover
and a single barrier cover system would be constructed over the
1973 disposal area and the Overland Flow Area, respectively. The
single barrier cover system on the Overland Flow Area would
prevent direct transfer of contaminants from surface soils to
Northeast Branch during precipitation events. This cover would
also limit contaminant migration to ground water by limiting
-------
Hurray Ohio Dump NPL Site
Record of Decision
Section V7
Page 9
infiltration of precipitation. Once the cover systems have been
placed, the soil cover and disturbed areas would be vegetated to
provide erosion control and limit surface-water infiltration.
Routine inspection and maintenance of the cover systems on the.
disposal areas would be conducted to maintain the integrity of
the cover systems. Installation of additional fencing around the
perimeter of the Site would limit direct contact with landfill
contents and would prohibit vehicular access over the disposal
areas.
Slope stabilization of the post-1973 disposal area would be
implemented to reduce erosion of the slope and sedimentation into
Northeast Branch, as described in previous Remedial Alternatives.
Access restrictions and deed restrictions described in previous
Remedial Alternatives would be maintained to reduce the potential
of direct contact with landfill contents and restrict future use
options of the property.
2. Ground Water
Remedial Alternative 6 employs Site monitoring and deed
restrictions for addressing the potential risks to human health
associated with ground water at the Site. Sampling and analysis
would be performed at selected wells.in the existing monitoring
well network at the Site to gauge ground-water contaminant
concentrations, as previously described. Periodic ground-water
monitoring would be performed to confirm the continued stability
of aquifer characteristics. Deed restrictions described for the
previous remedial alternatives would be implemented.
3. Surface Water
Remedial Alternative 6 involves installation of chain-link
fencing around the seep areas. This would prohibit direct
contact with seeps, thus restricting access and exposure to
humans and animals. Sampling would be conducted on a quarterly
basis at SW-007, SW-BKG and SW-A. Surface water sampling would
be for TAL metals. This would mark improvements to water quality
of Northeast Branch after implementation of containment measures
at the Site.
4. Costs and Time to Implementation
The present worth cost of Alternative 6 is $2,000,000. Although
no exact implementation times are available, EPA estimates the
time required to implement each remedy, from shortest to longest,
by alternative number, is as follows:
#1 < #2 < #3 <#6'<#8 <#4 <#7 <#5
-------
Murray Ohio Dump NPL Site
Record of Decision
Section VI
Page 10
Alternative #6 has a moderate implementation time.
Because this alternative would result in contaminants remaining
on-Site, CERCLA requires that the Site be reviewed every five
years. If justified by the review, remedial actions would be
implemented at that time to remove or treat contamination.
Remedial Alternative 7: Containment and Surface Water Options in
Alternative 6 Plus a Seep Collection and Treatment Contingency
Measure and Cover Improvements on the Post-1973 Disposal Area
Remedial Alternative 7 involves the same containment options and
sampling for surface water as Alternative 6 plus additional
improvements' on the post-1973 disposal area, however, a
contingent option for seeps is also included. At EPA's
discression, as part of a five-year-review for the Site, if
ground-water, seep water, and surface water quality in Northeast
Branch are not observed to improve after construction of the
cover systems, the seep collection, treatment and discharge
contingency would be implemented.
1. Landfill Contents
This alternative includes maintaining cover systems over the
disposal areas, upgrading the stormwater management controls,
construction of an enhanced single barrier cover system over the
pre-1973 disposal area, construction of a single barrier cover
system over the Overland Flow Area, and construction of a durable
surface cover over the 1973 disposal area. In addition,
improvements would be constructed on the post-1973 disposal area
to bring it up to RCRA standards.
For suitable construction of the enhanced single barrier cover
system, the pre-1973 disposal area would be regraded to provide a
minimum slope of approximately 5 percent for positive surface-
water run-off. Approximately 8,300 cubic yards of fill material
would be imported from a borrow source adjacent to the Site so
that disturbance of the existing cover and the wastes would not
be necessary. Upgrading to an enhanced single barrier cover
system over this disposal area would provide further protection
to human health and the environment by blocking potential
exposure pathways and reducing infiltration into the landfill
contents.
As described in Remedial Alternative 3, a durable surface cover
and a single barrier cover system would be constructed over the
1973 disposal area and the Overland Flow Area, respectively. The
single barrier cover system on the Overland Flow Area would
-------
Hurray Ohio Dump NPL Site
Record of Decision
Section VJ
Page 11
prevent direct transfer of contaminants from surface soils to
Northeast Branch during precipitation events. This cover would
also limit contaminant migration to ground water by limiting
infiltration of precipitation. Once the cover systems have been
placed, the soil cover and disturbed areas would be vegetated to
provide erosion control and limit surface-water infiltration.
Routine inspection and maintenance of the cover systems on the
disposal areas would be conducted to maintain the integrity of
the cover systems. Installation of additional fencing around the
perimeter of the Site would limit direct contact with landfill
contents and would prohibit vehicular access over the disposal
areas.
Slope stabilization of the post-1973 disposal area would be
implemented to reduce erosion of the slope and sedimentation into
Northeast Branch, as described in previous Remedial Alternatives.
Access restrictions and deed restrictions described in previous
Remedial Alternatives would be maintained to reduce the potential
of direct contact with landfill contents and restrict future use
options of the property.
2. Ground Water
Remedial Alternative 7 employs Site monitoring and deed
restrictions as remedial actions for addressing the potential
risks to human health associated with ground water at the Site.
Sampling and analysis would be performed at selected wells in the
existing monitoring well network at the Site to gauge ground-
water contaminant concentrations, as previously described.
Periodic ground-water monitoring would be performed to confirm
the continued stability of aquifer characteristics. Deed
restrictions described for the previous remedial alternatives
would be implemented.
In addition, Remedial Alternative 7 involves the same collection
of ground water and the five seeps along Northeast Branch, as
outlined in Alternative 4. If the seep remedial measures are
required, on-Site and off-Site treatment options are available.
Ground water and the seeps would be collected in a subsurface
trench and piped to a collection point for on-Site treatment. A
trench drain would be installed to collect both the seep
discharge and contributing ground water from the Site that is
baseflow to Northeast Branch. Collected seep and ground-water
discharge would flow to a sump at the lowest collection point and
then be pumped to a treatment system located in the vicinity of
the headwaters of Northeast Branch.
Treatment of the ground-water and seep discharge would be
accomplished through chromium reduction, metals precipitation,
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coagulation/flocculation and gravity clarification. After
exiting the treatment train, the treated ground-water and seep
discharge would be pumped to a sludge thickening tank to settle
precipitated material and then piped to a gravity clarifier for
additional particulate and solids removal. The settled sludge
would then be collected in a sludge accumulation tank and
transported off-Site for disposal. Prior to surface water
discharge through a transfer pump, the treated ground water and
'seep discharge would flow through a polishing filter to remove
any residuals and the flow rate would be equalized in an
accumulation tank.
In the event of on-Site seep treatment, improvements to the
existing roadway at the Site would be required to permit tanker
truck access for treatment reagent and residual transport.
Approximately 18,000 square feet of wooded area would have to be
cleared, grubbed and regraded to make room for the treatment
system compound and truck turn-around area.
3. Surface Water
Remedial Alternative 7 involves installation of chain-link
fencing around the seep areas. This would prohibit direct
contact with seeps, thus restricting access and exposure to
humans and animals. Surface water sampling would be conducted on
a quarterly basis at SW-007, SW-BKG and SW-A. Sampling would be
for TAL metals. This would mark improvements to water quality of
Northeast Branch after implementation of containment measures at
the Site.
4. Costs and Time to Implementation
The present worth base cost of Alternative 7 is $3,416,000. An
additional $2,100,000 would be added to this cost if the seep
contingency were invoked and treatment occurred on-Site.
Likewise, if the seep contingency were required and treatment was
off-Site, an additional $7,900,000 would be added to the base
cost. Although no exact implementation times are available, EPA
estimates the time required to implement each remedy, from
shortest to longest, by alternative number, is as follows:
#1 < #2 < #3 <#6 <#8 <#4 <#7 <#5
Alternative #7 will take longer than most of the other remedies
to implement.
Because this alternative would result in contaminants remaining
on-Site, CERCLA requires that the Site be reviewed every five
years. If justified by the review, remedial actions would be
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implemented at that time to remove or treat contamination.
Remedial Alternative 8: Alternative 7 Plus Containment Upgrades
to the Pre-1973 Disposal Area, the Overland Flow Area, and the
1973 Disposal Area
Alternative 8, double barrier containment with contingent seep
controls, is the most rigorous alternative. It is composed of
the same remedial measures as Alternative 7, except for the
following upgraded components: a) The Pre-1973 disposal area
would be covered with a new double barrier cover system instead
of an enhanced single barrier cover system; b) The Overland
Flow area would be covered with a new double barrier cover system
instead of a new single barrier cover system; and c) The 1973
disposal area would be covered with an enhanced single barrier
cover system instead of a durable surface cover.
1. Landfill Contents
Refer to this portion of Alternative 7, as it is identical. The
only additions are those listed in the preceding paragraph. The
same durable road surface would be required to be constructed and
inspection and maintenance requirements would be the same as for
Alternative 7.
2. Ground Water
Refer to this portion of Alternative 7, as it is exactly
identical.
3. Surface Water
Refer to this portion of Alternative 7, as it is exactly
identical.
4. Costs and Tine to Implementation
The present worth base cost of Alternative 8 is $3,516,000. An
additional $2,100,000 would be added to this cost if the seep
contingency were invoked and treatment occurred on-Site.
Likewise, if the seep contingency were required and treatment was
off-Site, an additional $7,900,000 would be added to the base
cost. Although no exact implementation times are available, EPA
estimates the time required to implement each remedy, from
shortest to longest, by alternative number, is as follows:
#1 < #2 < #3 <#6 <#8 <#4 <#7 <#5
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This estimation assumes high efficiency of the cover systems once
implemented and in estimating a relative time does not assume
that the seep contingency will be necessary. Alternative #8 will
therefore have a moderate implementation time.
Because this alternative would result in contaminants remaining
on-Site, CERCLA requires that the Site be reviewed every five
years. If justified by the review, remedial actions would be
implemented at that time to remove or treat contamination.
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VII. COMPARATIVE ANALYSIS OF REMEDIAL ALTERNATIVES
A detailed comparative analysis was performed on the eight
remedial alternatives developed during the FS and the
modifications submitted during the public comment period using
the nine evaluation criteria set forth in the NCP. The
advantages and disadvantages of each alternative were evaluated
in order to identify the alternative with the best balance among
the nine criteria.
Threshold Criteria;
Aj. OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
This criterion addresses whether or not an alternative provides
adequate protection and describes how risks are eliminated,
reduced, or controlled through treatment and engineering or
institutional controls.
Alternatives 7 and 8 are the most desirable and are estimated to
reduce seep and ground water levels of contaminants to Ambient
Water Quality Criteria (AWQC) and Maximum Contaminant Levels
(MCLs) for nickel, chromium and hexavalent chromium within a
reasonable time frame. Both of these alternatives also eliminate
the risk due to a child ingesting soils in the Overland Flow
Area. Alternative 7 is estimated to achieve the same results as
Alternative 8, however, Alternative 8 costs more.
Due to the lack of a seep control contingency, EPA is not
confident that Alternative 6 will meet acceptable levels of the
signature contaminants in ground water. If the cap systems were
to function ideally and prevent all infiltration, the system
would naturally cleanse itself via the seeps and meet these
levels, however, there is no guarantee of this. Alternative 6
does, however, eliminate the risk due to a child ingesting soil
in the Overland Flow Area. If Alternative 6 were to achieve
health-based levels it would most likely do so in the same amount
of time it would take Alternatives 7 or 8 to do so in the event
that their seep contingencies were not necessary.
Alternative 5, which involves removing the ground water via
vertical extraction wells and treating it would be protective of
human health and the environment if effective. It is not
thought, however, that this remedy will be effective due to the
inherent uncertainty (because the soil zone dye traces have been
ineffective) associated with well installation in this karst
hydrogeologic setting. If Alternative 5 were implemented and
effective, it would take the longest of all remedies to achieve
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protection. Alternative 5 does, however, eliminate the risk due
to a child ingesting soil in the Overland Flow Area.
While Alternative 4 does have a seep contingency, the cap
systems/ identical to those in Alternative 5, are not as
protective as those of Alternatives 6 through 8. EPA is not
confident that all health based levels of contaminants in the
ground water beneath the Site will be met, however, the risk due
to a child ingesting soil from the Overland Flow Area is
eliminated by this alternative. Relative to the others, this
alternative has a moderate time to achieve its goals.
Construction time would be on the long side compared to the other
alternatives.
Alternative 3, which involves various upgrades to the cap systems
is not thought to be protective of human health and the
environment for ground water/seeps since it neither has the
conservative cover of higher numbered alternatives nor the seep
collection contingency. It should, however, be protective of a
child ingesting soil in the Overland Flow Area. Alternative 3 is
estimated to take a moderate time to both construct as well as
achieve its goals once construction is complete.
Alternative 2 is not estimated to be protective for ground
water/seeps or a child ingesting soil since the cover systems
outlined are less conservative than Alternative 3 and do not even
include the Overland Flow Area. Since its goals are not high,
its implementation time and time to achieve its goals are quite
rapid.
Alternative 1 is not estimated to be protective of human health
and the environment since it does not eliminate, reduce, or
control risks by treating contamination in the environment.
JT.. COMPLIANCE WITH APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENTS (ARARS)
This criterion addresses whether or not an alternative will meet
all ARARs or provide grounds for invoking a waiver. Each
alternative was evaluated for compliance with ARARs, including
chemical-specific, action-specific, and location-specific ARARs.
For a complete discussion of all ARARs and "To be considered"
(TBC) criteria, refer to Section IX of this document.
Alternatives 1 and 2 do not comply with Maximum Contaminant
Levels (MCLs) and Maximum Contaminant Level Goals (MCLGs) set
forth in the Safe Drinking Water Act (SDWA), 40 CFR Part 141,
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Subparts B, F, and G, nor do they comply with the Ambient Water
Quality Criteria (AWQC) set forth in 40 CFR Part 403, Sections
303 and 304 of the Clean Water Act (CWA). They also do not
comply with the Resource Conservation and Recovery Act (RCRA)
Subtitle C, 40 CFR Part 265.310; which regulates landfill closure
and post-closure activities.
Alternative 3 will not meet AWQCs or RCRA Subtitle C and EPA is
not confident that it will meet MCLs. Alternative 4 will meet
AWQCs, but will not comply with RCRA Subtitle C and will probably
not comply with MCLs either.
If effective, Alternative 5 would comply with MCLs and AWQC,
however, due to the karst hydrogeologic setting at the. Site, EPA
doubts the effectiveness of a ground-water extraction scenario.
The cap scenario for this alternative will still not comply with
RCRA Subtitle,C for the Post-1973 disposal area.
Alternative 6 will not meet AWQCs. There is no way to predict
with certainty until the caps are in place and ground-water
monitoring occurs if it will meet MCLs, but EPA is not confident
that these levels will be achieved by the proposed cap
augmentations.
Alternatives 7 and 8 will meet AWQCs and EPA feels confident that
they will meet MCLs. They also comply with RCRA Subtitle C.
Alternatives 7 and 8 comply with all ARARs that are known at this
time.
Primary Balancing Criteria;
C. LONG-TERM EFFECTIVENESS AND PERMANENCE
This refers to the ability of an alternative to maintain reliable
protection of human health and the environment, over time, once
cleanup objectives are met.
Since their caps are more conservative and they employ seep
contingencies to take up where the caps may not be effective,
Alternatives 7 and 8 are the most effective in the long term.
Alternatives 5 and 6 can be considered only partial for long-term
effectiveness since Alternative 5 is not thought to be a
technology which will work to extract ground water at the Site
and Alternative 6 has no seep collection to account for cap
systems which might not totally prevent all infiltration.
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EPA does not feel confident about the long-term effectiveness of
Alternative 4 since even though it has a seep contingency, its
cover system scenario is not conservative enough for the long-
term.
Alternatives 2 and 3 can also only be considered partial for
long-term effectiveness since EPA doubts that either of these
will achieve health based levels in ground water and seeps.
Alternative 2 also does not outline any cover for placement on
the Overland Flow Area.
By its nature, Alternative 1 is not at all long-term effective.
D^ REDUCTION OF TOXICITY. MOBILITY OR VOLUME THROUGH TREATMENT
This is the anticipated performance of the treatment technologies
an alternative may employ. The degree of reduction of toxicity,
mobility or volume through treatment varies depending on the
capping and ground-water/seep collection scenarios in an
alternative.
The cap systems placed over the Site in several of the
alternatives will act to prevent infiltration of precipitation
through the landfill areas, thus keeping leachate from coming out
the sides of the landfills in ground-water seeps, particularly
along Northeast Branch. The caps placed over the landfill areas
will act to contain the plume in this order of effectiveness: 8 &
7, 6 & 4 , 5, 3, 2.
Alternatives 4,5,7 and 8 all utilize the same type of treatment
for ground-water/seeps, once collection is complete. The
chromium reduction and metals precipitation process is a well-
established method for removing the metal contaminants, such as
those at the Murray Site, from water. This is a reliable
treatment process which will adapt well to varying influent
concentrations.
E. SHORT-TERM EFFECTIVENESS
This involves the period of time required to achieve protection
and any adverse impacts on human health and the environment that
may be posed during the construction and implementation period
until cleanup objectives are achieved. The following factors
were used to evaluate the short-term effectiveness of each
alternative: protection of the community during remedial
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actions, protection of workers during remedial actions,
environmental impacts from implementation of alternatives, and
the time until remedial action objectives are met.
With respect to protection of the community, Alternatives 2-8
will not pose additional risk to the community, although there
may be some slight inconveniences in some cases. Likewise,
Alternative 1 poses no risk to the community over what already
exists.
Alternatives 7 and 8 are more effective and protective to the
community in the short-term than are Alternatives 4 and 6.
Following these would be Alternatives 3 and 5 with only partial
effectiveness. Last for short term effectiveness would be
Alternatives 2 and 1, respectively.
Risks to workers for all of the alternatives can be minimized
with safe working practices. Alternatives 4, 7 and 8 may involve
more risk than the others since placement of the seep collection
system involves blasting the rock outcrops along Northeast Branch
with explosives.
With respect to environmental impacts, the ground-water plume
will be contained in the order of effectiveness cited in the
previous section, "Reduction of Toxicity, Mobility and Volume".
Alternatives 4, 7 and 8 will impact the environment in a greater
way than the other alternatives due to the blasting of the banks
around Northeast Branch. The environment of this shallow
ephemeral stream would be significantly altered and would require
rejuvenation when seep collection systems were finally in-place.
Assuming that seep contingencies are not needed, Alternatives 7
and 8 will achieve the best degree of protection in the same time
frame as Alternatives 6 and 4 will achieve a lesser degree of
protection. In approximately the same time frame, Alternatives
5, 3 and 2 will achieve only partial protection. Should the seep
contingency be required for Alternatives 4, 7 and 8, this will
add to their implementation times by approximately one and one-
half years.
F. IMPLEMENTABILITY
This is the technical and administrative feasibility of an
alternative, including the availability of goods and services
needed to implement the solution. Alternatives 1 through 8 will
be feasible, both technically and administratively. Required
services and materials generally are available, and the
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technologies used for all alternatives rely on standardized
construction methods and demonstrated technologies.
Alternative 1 would be the most implement able, as it involves no
remedial activities. Alternative 2 and then 3 would be
considered the next most implementable since they involve only
some upgrades to the existing cap systems. Because of its
better-developed cap systems, Alternative 6 is slightly more
difficult to implement, but still not as difficult as Alternative
4 since Alternative 4 involves installing a seep collection
system. Alternative 5, with ground-water extraction wells falls
somewhere between 4 and 6 for implementability concerns.
Alternatives 7 and 8 would, be the most difficult to implement
since they have the most advanced cap systems and possible
construction of seep collection systems.
The ease of implementability is, however, not largely different
from the easiest action (Alternative 2) to the most advanced
'{Alternative 8} .
G. COST
Cost includes capital costs as well as operation and maintenance
costs and is presented in present value. This evaluation
examines the estimated costs for implementing the remedial
alternatives. The estimated present-worth value of each
alternative is as follows:
Alternative 1: $0
Alternative 2: $370,000
Alternative 3: $1,700,000
Alternative 4: $4,500,000
Alternative 5: $7,200,000
Alternative 6: $2,000,000
Alternative 7: $3,416,400
(with seep treatment on-Site, add:) $2,100,000
(with seep treatment off-Site, add:) $7,900,000
Alternative 8: $3,516,400
(with seep treatment on-Site, add:) $2,100,000
(with seep treatment off-Site, add:) $7,900,000
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Modifying Criteria:
H. STATE ACCEPTANCE
This indicates whether, based on review of the RI report, FS
Report, and Proposed Plan, U.S. EPA and TDEC agree on the
preferred alternative. EPA and TDEC are in agreement on the
selected alternative. Please refer to Appendix A of this
document which contains a letter of concurrence from TDEC.
I. COMMUNITY ACCEPTANCE
This indicates the public support of a given alternative. This
criterion is addressed in the Responsiveness Summary. Appendix B,
to this document. The community accepts the selected remedy.
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VIII. SELECTED REMEDY
Based upon consideration of the requirements of CERCLA, the NCP,
the detailed analysis of alternatives and public and State
comments, EPA has selected a source control/ground-water remedy
for this Site. At the completion of this remedy, the risk
associated with this Site has been calculated at 10"6 which is
determined to be protective of human health and the environment.
The total present worth base cost of the selected remedy,
Alternative #7, is estimated at $3,416,400. Additional present-
worth costs of $2,100,000 and $7,900,000 are estimated if seep
control is required and treatment is on- and off-Site,
respectively.
A. SOURCE CONTROL
Source control remediation will address the contaminated soils
and sludges at the Site.
The selected remedy includes maintaining the cover system over
disposal areas, upgrading the storm-water management controls,
construction of an enhanced single barrier cover system over the
pre-1973 disposal area, construction of a single barrier cover
system over the Overland Flow Area, and construction of a durable
surface cover over the 1973 disposal area. Slope Stabilization
and cap improvements would be implemented for the post-1973
disposal area.
For suitable construction of the enhanced single barrier cover
system, the pre-1973 disposal area would be regraded to provide a
minimum slope of approximately 5 percent for positive surface-
water run-off. Approximately 8,300 cubic yards of fill material
would be imported from a borrow source adjacent to the Site so
that disturbance of the existing cover and the wastes would not
be necessary. Upgrading to an enhanced single barrier cover
system over this disposal area would provide further protection
to human health and the environment by blocking potential
exposure pathways and reducing infiltration into the landfill
contents.
A durable surface cover and a single barrier cover system would
be constructed over the 1973 disposal area and the overland flow
area, respectively. The single barrier cover system on the
Overland Flow Area would prevent direct transfer of constituents
from surface soils to Northeast Branch during precipitation
events and would also block the unacceptable future child
ingestion of soil scenario. Both covers would limit contaminant
migration to ground water by limiting infiltration of
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precipitation. Once the cover systems have been placed, the soil
cover and disturbed areas would be vegetated to provide erosion
control and limit surface-water infiltration. Routine inspection
and maintenance of the cover systems on the disposal areas would
be conducted to maintain the integrity of the cover systems.
Installation of additional fencing around the perimeter of the
Site would limit direct contact with the landfill contents and
would prohibit vehicular access over the disposal areas.
Slope stabilization of the post-1973 disposal area would be
implemented to reduce erosion of the slope and sedimentation into
Northeast Brar.ch. The cover system on this area would be
upgraded to comply with RCRA Subtitle C standards. Following
source control remediation, access restrictions and deed
restrictions (in the form of record notices placed on the site)
would be maintained to reduce the potential of direct contact
with landfill contents' and restrict future use options of the
property.
Performance Standards
1. Capping Standards
To insure protectiveness of human health and the environment,
EPA's Regional Toxicologist has calculated the following
allowable surficial soil concentrations for the Overland Flow and
Formerly Ponded Areas. Concentrations shall not exceed these
numbers once the cover system is in-place:
Total Chromium: 74,881 ppm
Hexavalent Chromium: 374 ppm
Nickel: 1,498 ppm
As stated in Section IX of this document, the regulations in the
Resource Conservation and Recovery Act (RCRA) Section 265.310,
Closure and Post-Closure Care, also provide standards for all of
the cover systems to be constructed at this Site.
2. Other Standards
Section IX of this document lists all other Applicable or
Relevant and Appropriate Requirements (ARARs) pertaining to this
remedial action at the Murray Ohio Site.
B. GROUND-WATER REMEDIATION
Capping is expected to reduce infiltration, thereby allowing
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natural attenuation processes to act in reducing contaminant
levels toward levels stated in Section IX of this document under
ARARs. If the capping and natural attenuation measures of the
selected remedy are not effective in bringing ground water to
acceptable levels, ground-water seep collection and treatment
measures will be employed. Ground water and the seeps would be
collected in a subsurface trench and piped to a collection point
for on-Site treatment. A trench drain would be installed to
collect both the seep discharge and contributing ground water
from the Murray Site that is baseflow to Northeast Branch. The
trench would be approximately four feet wide, with a 6-inch
perforated PVC pipe laid at the bottom of the trench. The trench
would be filled with gravel, covered with a 6-mil polyethylene
sheet, a minimum of one foot of soil, and revegetated. The
trench depth may vary from approximately 30 feet at SW-800 to
close to land surface at SW-250. The collected seep and ground-
water discharge would gravity flow to a sump at the lowest
collection point and then be pumped to a treatment system either
on- or off-Site.
Treatment of the water would be accomplished through chromium
reduction, metals precipitation, coagulation/flocculation, and
gravity clarification. Discharge of treated effluent would be to
Shoal Creek.
Performance Standards
1. Monitoring Locations and Parameters for Triggering Seep
Collection and Treatment Measures
Parameters: Full TCL/TAL list
Locations: - all ground-water monitoring
wells used in the RI
all seeps used in the RI
surface water at SW-BKG and
points SW007 and SW-A in
Northeast Branch
2. Treatment Standards
If the seep contingency is necessary, ground water and seeps
shall be treated at least until the following maximum
concentration levels are attained at the wells, ground-water
seeps and surface water stations designated by EPA as compliance
points:
Chromium: .1 ppm
Hexavalent Chromium: .1 ppm
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Nickel: . 1 ppm
3. Discharge Standards
Discharges from the ground water and seep treatment system shall
comply with all ARARs, including, but not limited to,
requirements of the National Pollutant Discharge Elimination
System (NPDES) permitting program under the Clean Water Act, 33
U.S.C. {1251 et sea.) and all effluent limits established by EPA,
as well as Tennessee Surface Water Quality Standards.
4. Design Standards
The design, construction and operation of the treatment system
shall be conducted in accordance with all ARARs. Design will
'also be performed in an effort to minimize all environmental
impacts to terrestrial and aquatic habitats in the area.
5. Other Standards
Section IX of this document lists all other Applicable or
Relevant and Appropriate Requirements (ARARs) pertaining to this
remedial action at the Murray Ohio Site.
C. COMPLIANCE TESTING AND MONITORING
No later than five years from the date of commencement of
remedial construction, a five year review will be completed for
the Murray Ohio Site since waste remains on-Site. Five year
reviews regularly occur after the first five-year-review at
intervals of no greater than five years.
Quarterly monitoring will be performed beginning with the date of
source-control construction completion for the parameters and
locations listed above for "Performance Standards/ Monitoring
Locations and Parameters for Triggering Seep Collection and
Treatment Measures". At the time of the first or any five-year-
review, EPA will evaluate quarterly monitoring performed to that
point and all ARARs in part IX of this document to determine if
the source-control component and natural attenuation are
functioning in an effective enough fashion to reduce levels of
contaminants to acceptable levels. Based upon this evaluation,
EPA may require employing the seep contingency measures in this
remedy.
If EPA determines that the seep measures in this remedy are
required, the constructed system's effectiveness will be
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evaluated by EPA based on the same parameters and locations used
to previously determine the need for the seep measures.
Should a five-year-review reveal any other inadequacies for the
source-control component, such as the "Capping Standards" under
"Source Control" in this section being exceeded, EPA will re-
evaluate the effectiveness of the source control component and
may make recommendations to improve its capabilities.
Any significant alteration of the environment in and around
Northeast Branch due to seep collection and treatment measures
(if necessary) will be repaired by methods such as dredging,
filling, planting vegetation to prevent erosion, etc..
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IX. STATUTORY DETERMINATIONS
Under its legal authorities, EPA's primary responsibility at
Superfund sites is to undertake remedial actions that achieve
adequate protection of human health and the environment. In
addition, Section 121 of CERCLA establishes several other
statutory requirements and preferences. These specify that when
complete, the selected remedial action for this Site must comply
with applicable or relevant and appropriate environmental
standards established under federal and State environmental laws
unless a statutory waivsr is justified. The selected remedy must
also be cost-effective and utilize 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 reduces the volume, toxicity
or mobility of hazardous wastes as their principle element. The
following sections discuss how the selected remedy meets these
statutory requirements.
A. PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
The selected remedy protects human health and the environment by
preventing infiltration of water into the waste. This, together
with natural attenuation, prevents migration of any contaminated
ground water in the plume beneath the surface or in leachate
seeps. The selected remedy also contains measures for collecting
and treating seeps should monitoring outlined in Section VIII of
this document reveal that the cap systems are not functioning
effectively. Discharge of the treated water would be to Shoal
Creek at concentrations protective of human health and the
environment.
Institutional controls and monitoring will insure that the public
is not affected by Site-related contaminants at a future time.
Implementation of Alternative #7 will not pose any unacceptable
short-term risks or cross-media impacts to the Site, the workers,
or the community. If seep collection and treatment measures are
required, the environment around Northeast Branch may be altered
temporarily, but will be restored.
B. ATTAINMENT OF APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENT OF ENVIRONMENTAL LAWS
The selected remedy of source control via- improving the cover
systems, possible seep collection with on-site treatment and
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discharge to Shoal Creek will comply with all applicable or
relevant and appropriate chemical, action, and location-specific
requirements (ARARs). The ARARs are presented below. Sludges
generated from on-site contingent treatment of seeps will be
transported off-Site for disposal. Discharge of contingent
treatment system effluent off-site to Shoal Creek will require an
NPDES permit. Contingent treatment may require off-site instead
of on-site treatment.
Action-Specific ARARs;
* Surface Discharge Standards for Treated Effluent,
50 FR 30784; 40 CFR 122.44(a), (i); 40 CFR 131; TWQCB
1200-4-5.02 &.03. Pertinent State water quality
standards must be complied with for discharge. These
standards may be in addition to or more stringent than
standards in the federal Clean Water Act. Applicable
since direct discharge of treatment system effluent is
a component of the selected remedy.
* Test Methods for Waste Constituents in Treated
Effluent, 40 CFR 136. Approved test methods for waste
constituents to be monitored must be followed.
Detailed requirements for analytical procedures and
quality control are provided. Potentially applicable
since direct discharge of treatment system effluent is
a component of the selected remedy.
* Fugitive Dust Emissions Standards for Excavation and
Grading, TDHE 1200-3-8-.01. Fugitive dust emissions
for particulates shall not exceed 5 minutes per hour or
20 minutes per day as to produce a visible emission
beyond the property line. Potentially applicable since
construction activities, including earth moving
activities, may release particulate matter into the
atmosphere.
* . Resource Conservation and Recovery Act (RCRA), 40 CFR,
Section 265.310, Closure and Post-Closure Care.
Applicable for the post-1973 disposal area since RCRA
regulated waste was disposed in this area and relevant
and appropriate for the remainder of the Site
* Tennessee Regulations for Non-Specific Earth Moving
Activities, TDHE 1200-1-7-.04-(2)-(i). Meet Subtitle 9
requirements and develop an erosion and sedimentation
control plan. Applicable since earth moving activities
are part of the selected remedy.
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Murray Ohio Dump NPL Site
Record of Decision
Section IX
* TDHE 1200-1-7-.04-(7)-(b), Tennessee Ground-water
Monitoring Requirements. Maintaining the quality of
ground water through monitoring requirements.
Potentially applicable since treatment technologies to
be used in the selected remedy include treatment of
ground water/seep water.
* Tennessee Landfill Requirements, TDHE 1200-1-7-.04-(8)
& TDHE 1200-l-7-.04-(8)-(c)-3-(i) & (iii) . The cover
system shall consist of at least 36 inches of compacted
soil with a minimum of 12 inches of soil which will
support the growth of suitaole vegetation. Applicable
since the disposal areas have been used as industrial
waste landfills.
* Tennessee Closure and Post-Closure Requirements, TDHE
1200-1-11-05 (14)(e). Provide long-term minimization
of migration of liquid; function with minimum
maintenance; promote drainage and minimize erosion/
accommodate settling and subsidence; and have a
permeability of less than or equal to the permeability
of a bottom liner system or natural subsoils present.
Post closure requirements include ground-water
monitoring. Applicable to the larger landfill since
F006 waste was disposed of in this area after 1980 and
relevant and appropriate to the other areas because
they contain the same or similar waste.
Location-Specific ARARs;
* National Archaeological and Historical Preservation
Act, 16 U.S.C., Section 469; 36 CFR Part 65. Action to
recover and preserve artifacts. Potentially applicable
based on May 27, 1993, correspondence from TDEC
Division of Archaeology. Prehistoric and historic
archaeological resources are potentially located in the
project area. Action to recover and preserve artifacts
located in the undisturbed areas of the site may
therefore be required.
Chemical-Specific ARARs;
* Safe Drinking Water Act (40 CFR Part 141). Subparts B
and G provide maximum concentration levels (MCLs)
allowable for drinking water, i.e., ground water and
ground-water seeps at and around the Site. Relevant
and Appropriate to ground water beneath and seeps
emanating from the Site.
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Hurray Ohio Dump NPL Site
Section CC
Page 4
* EPA Ambient Water Quality Criteria (AWQC), Clean Water
Act, 40 CFR 403. AWQC are identified in Section
121(d)(2)(A) of CERCLA, as amended by SARA to be ARARs.
Gives chemical-specific concentration-based standards
for surface water bodies. AWQC are developed as
guidance for the States to develop ambient surface
water quality standards that will be fully protective
of human health and the environment. As such, AWQC are
relevant and appropriate to the selected remedial
action. Discharge of the treated effluent from the
site must not result in ambient surface water
concentrations that exceed chemical-specific AWQC.
* Tennessee Water Quality Criteria (1200-4). Gives
chemical-specific concentration-based standards for
protection of human health and the environment in
surface water bodies. Applicable to streams around the
site.
Other Criteria To-Be-Considered;
* Covers for Uncontrolled Hazardous Waste Sites,
EPA/540/2-85/002. Provides guidance for cover design,
gas and infiltration control, cost estimation, and
construction.
* Secondary Drinking Water Standards, 40 CFR 143. Sets
forth nonenforceable guidelines to states.
* EPA Ambient Water Quality Criteria Guidance (EPA 440/5-
80-068, 077, 041).
C. COST-EFFECTIVENESS
The selected remedy is cost-effective because it has been
determined to provide overall effectiveness proportional to its
costs, the net present worth value being $3,416,400 plus
$2,100,000 if seep measures are required and treatment is on-Site
or plus $7,900,000 if treatment is off-Site. The only other
alternative which would meet all ARARs for the Site was
Alternative #8 which is less cost-effective. In addition to not
meeting ARARs for the Site, the other alternatives are only
partially protective.
D. UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT
TECHNOLOGIES (OR RESOURCE RECOVERY TECHNOLOGIES) TO THE
MAXIMUM EXTENT PRACTICABLE
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Murray Ohio Dump JVPL Site
Record of Decision
Section IX
Pages
EPA and the State of Tennessee have determined that the selected
remedy represents the maximum extent to which permanent solutions
and treatment technologies can be utilized in a cost-effective
manner for the Murray Ohio Dump Site. Of those alternatives that
are protective of human health and the environment and comply
with ARARs, EPA and TDEC have determined that the selected remedy
provides the best balance of tradeoffs in terms of long-term
effectiveness and permanence, reduction of toxicity, mobility, or
volume achieved through treatment, short-term effectiveness,
implementability, and cost, also considering the statutory
preference for treatment as a principle element and community
input.
The selected remedy will be easy to implement technically since
it relies on standard construction methods and treatment methods
which have been used extensively in a wide range of applications.
Of Alternatives #7 and #8, which are equally protective,
Alternative #7 (the selected remedy) is more cost-effective.
E. PREFERENCE FOR TREATMENT AS A PRINCIPLE ELEMENT
If treatment is found necessary, the remedy provides for reducing
contaminants in ground water to acceptable levels via metals
precipitation, coagulation, flocculation and filtration. The
selected remedy also contains provisions for five-year-reviews.
These provisions insure that the remedy will be evaluated at
intervals of no less than five years starting from the date of
construction commencement and, if it is not meeting the standards
set forth in this Record of Decision, will be upgraded to meet
them.
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Murray Ohio Dump NPL Site
Record of Decision
Section X
Page 1
X. SIGNIFICANT CHANGES TO ALTERNATIVE 7
During the public comment period on the Proposed Plan, EPA
received comments from Geraghty & Miller, Inc. on behalf of
Murray Ohio Manufacturing Co. These comments proposed changes to
the monitoring program for determining the necessity of seep
control and collection measures after cap repairs are completed.
Geraghty & Miller also expressed concern that the construction
work required to install the seep collection system would destroy
the natural environment of the upper reaches of Northeast Branch.
EPA feels that some of Geraghty & Miller's ideas are of merit and
worth incorporating into the ROD as changes since the Proposed
Plan.
Deviations made from the Proposed Plan as a result of Geraghty &
Miller's March 29, 1994, comments include changing the monitoring
period for determining if the seep measures are necessary and
adding in measures to insure that Northeast Branch is protected
in the event that the seep construction occurs.
In the Feasibility Study, EPA had originally stated that a
monitoring period of one year (4 quarters) from the date of
construction would be necessary to determine if seep collection
and treatment measures would be necessary. Geraghty & Miller
proposed five years (20 quarters) of seep collection as a period
for determining if the additional construction should take place.
EPA feels that the 20 quarters is quite excessive while one year
may or may not be enough to make this determination. As a
result, EPA has incorporated measures into the ROD which would
make the evaluation for seep measures part of the five-year-
review process. As stated previously, the first five-year-review
can occur at any time before five years from the date of
construction commencement with successive five year reviews
occurring at five year intervals thereafter. In this way, data
can be evaluated quarterly as it is generated, thus allowing for
a more appropriate time (chosen by EPA) to make the determination
for or against additional construction for seep controls.
Locations stated in Section VIII of this ROD are as stated in the
FS and will still be used as sampling points. A full TCL/TAL
scan will be run at each point. EPA still agrees with and will
use Geraghty & Miller's sampling methodology, health and safety
measures and data validation procedures presented in the March
29, 1994, submittal.
EPA is also concerned with possible damage to the Northeast
Branch environs, which is exactly the area which the remedy seeks
to protect. The five-year-review measures outlined in the
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Murray Ohio Dump NPL Site
Record of Decision
Section X
Page 2
previous paragraph should eliminate making a decision on a firm
date when concentrations may well be declining towards and near
reaching acceptable levels. The seep contingency portion of the
selected remedy will only be invoked if after quarterly
monitoring in what EPA deems a reasonable time frame, it appears
that levels of contaminants are not close to reaching acceptable
levels.
Measures for restoring Northeast Branch and its surroundings have
also been incorporated into the ROD for the event that the seep
construction is necessary.
Please see Appendix B to this document which is the
Responsiveness Summary to the Proposed Plan. The Responsiveness
Summary contains greater details on Geraghty & Miller's proposed
modifications as well as EPA's responses to each issue raised.
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Appendix A
Letters from Support Agencies
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STATE OF TENNESSEE
DEPARTMENT OF ENVIRONMENT AND CONSERVATION
NASHVILLE ENVIRONMENTAL FIELD OFFICE
M i n i n n /i 537 BRICK CHURCH PARK DRIVE
May 10, 1994 NASHVILLE, TENNESSEE 37243-1550
Ms. Patricia C. Fremont
Remedial Project Manager
Kentucky/Tennessee Remedial Section
United States Environmental Protection Agency
Region IV
345 Courtland Street, N. E.
Atlanta, Georgia 30365
Re: Murray Ohio Dump NPL Site, Lawrenceburg,
Tennessee. (DSF site # 50-502)
Subject: Review of the Draft Record of Decision and
Responsiveness Summary
Dear Ms. Fremont:
Division of Superfund personnel have reviewed the Draft Record of
Decision and Responsiveness Summary for the Murray Ohio Dump NPL
Site. The major components of the selected remedy include:
* Constructing an enhanced single barrier cover
system over the pre-1973 disposal area;
* Slope stabilization of the post-1973 disposal area
with improvements on the existing cover;
* Constructing a durable surface cover over the 1973
disposal area;
* Constructing a single barrier cover system over
the overland flow area;
* Deed restrictions and fencing around the disposal
areas;
* Continued maintenance of the cover systems;
* Site monitoring; and
* Contingent construction of a seep collection and
treatment system with discharge of treated
effluent to Shoal Creek or a water treatment
facility.
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We feel that the selected remedy adequately addresses State
concerns and is appropriate for this site based on the existing
known conditions.
Sincerely,
Clinton W. Wilier
Director
Division of Superfund
xc: Nashville Field Office
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Appendix B
Responsiveness Summary
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Murray Ohio Dump NPL Site
Record of Decision
Appendix B,Refpon*ipaies* Summary
Pagel
APPENDIX B
MURRAY OHIO DUMP HPL SITE
RESPONSIVENESS SUMMARY
A. OVERVIEW
When the public comment period began, EPA had selected a
preferred alternative for the Murray Ohio Dump Site in.
Lawrenceburg, Tennessee. EPA's preferred alternative addressed
the soil and ground-water/seep contamination problems at the
Site. The preferred alternative involved placing different types
of caps over the various Site areas, maintenance and monitoring,
and contingent seep collection, treatment and discharge if
necessary. If seep measures were employed, treated seep/ground
water would be returned to Shoal Creek.
Judging from the comments received during the public comment
period, the residents and city officials of Lawrenceburg and the
Tennessee Department of Environment and Conservation (TDEC) would
support the cap enhancements and contingent seep measures. In a
letter dated March 29, 1994, the PRPs had some concerns about the
monitoring interval from which data would be taken to evaluate
the need for seep measures. As written in Section X of the ROD
and below, EPA has modified the ROD somewhat since some of these
suggestions are practical. The PRPs were also concerned .that the
seep measures, if constructed, would destroy the upper reaches of
Northeast Branch. EPA agrees that this is precisely the
environment that the selected remedy plans to protect and has
also made allowances for this, as in Section X and below.
These sections follow:
* Background on Community Involvement
* Summary of Comments Received During the Public Comment
Period and Agency Responses
Part I: Summary and Response to Local Community
Concerns
Part II: Comprehensive Response to Specified
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Murray Ohio Dump KPL Site
Record of Decision
Legal and Technical Questions
Remaining Concerns
Attachment: Community Relations Activities at Murray
Ohio Dump
B. BACKGROUND ON COMMUNITY INVOLVEMENT
A core group of citizens whose property is closest to the Murray
Ohio Dump site has always been, and continues to be, extremely
concerned about the site. Several of these citizens have written
letters to TDEC concerning animals that have died on their
property, the condition of ground water, and other general
inquiries about the Site.
In contrast, other citizens are aware of the Site, but have not
expressed undue concern. Furthermore, there is little official
documentation of community concern regarding the Site. Local
officials could remember no verbal complaints or questions about
the Site and the Site has not been an issue in city elections.
During interviews, residents and local officials expressed
concern for private wells in the area, even though all of the
citizens who use well water have access to city water. The
homeowners with well water, however, do not want city water
because of the expense and the fluoride in the water.
Although everyone interviewed knew about the Site's existence, no
one except a few close neighbors considered the Site to be a
problem. These neighbors reported that in the past they had to
make repeated calls'to TDEC before well water testing occurred.
They were extremely concerned since learning that Murray Ohio's
contractor would be conducting water sampling from then on. They
said they would not feel confident that the results they received
would be correct.
City and County officials wanted to be kept informed about Site
findings, as did the Site's neighbors.
The major concerns expressed during the remedial planning
activities at the Murray Ohio Dump Site focused on the possible
health effects from contamination at the Site. These concerns
and how EPA addressed them are described below:
1. Several citizens living nearest to the Site expressed
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Murray Ohio Dump NPL Site
Record, of Decision
Appcjuux Bf RctponMiucnets Suaunsuy
Pages
concerns about using their well water. Citizens questioned
Murray Ohio's contractor performing tests on their wells.
EPA Response: EPA informed citizens of past sampling events
performed by TDEC which had revealed no impacts to
residential wells in the area. Citizens were reassured that
EPA would be overseeing Murray's contractor in the field as
well as evaluating all sampling results.
2. Citizens noted that there had been several fish kills near
the Site. Eight cows on a nearby farm had to be killed
after coming down with a disease, which their owner
attributed to the Site. One citizen noted that he stopped
hunting in the area after killing a raccoon whose teeth were
rotting and who appeared to be under-nourished. No one
expressed any human health concerns about the Site.
EPA Response: EPA stated that all the water and sediments
of all streams in the area would be sampled to determine the
" cause of the fish kills. EPA thanked the citizens for
sharing the incidents concerning cattle and raccoons and
said that this information would be taken into account when
designing the studies and evaluating results.
3. Local citizens were concerned about the effect the Site was
having on property values.
EPA Response: EPA sympathized and said that it hoped that
remedial activities at the Site would help bring the
property values up.
C. SUMMARY OF COMMENTS RECEIVED DURING THE PUBLIC COMMENT
PERIOD AND AGENCY RESPONSES
The public comment period on the proposed plan for the Murray
Ohio Dump Site was held from February 26, 1994, to March 29,
1994. EPA held a public meeting on March 8, 1994, to present the
proposed plan to the public. Comments received during this time
are summarized below. Part I of this section addresses those
community concerns and comments that are non-technical in nature.
Responses to specific legal and technical questions are provided
in Part II.
Part I - Summary and Response to Local Community Concerns
Comments Made During the March 8, 1994, EPA Public Meeting
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Hurray Ohio Dump KPL Site
Record of Decision
Page 4
For the detailed transcript of the public meeting, please consult
the administrative record for the Murray Ohio NPL Site.
1. A citizen wanted to know how deep the contaminants went down
into the soil and ground water. This same citizen also
wanted to know what the concentration of chromium in the
Cothren Spring was.
EPA Response: EPA stated that the original trenches for
disposing of waste had been dug 8 to 12 feet deep, but that
contamination had migrated downward into the ground water. EPA's
hydrologist explained that the contamination flowed down through
the Fort Payne soil layer and limestone layer (ranging from 10 to
80 feet) after which it flowed to Northeast Branch.
EPA responded that the data taken in TDEC's off-Site private well
surveys revealed that in 1990, the chromium level in the Cothren
Spring was .001 parts per million (ppm), as compared to the
ground-water protection standard of 0.1 ppm and that nickel was
below the detection limit. In 1991 sampling, both chromium and
nickel were below the detection limit. In 1992, chromium was
.001 ppm again and nickel was below the detection limit.
Citizens were advised to consult the information repository in
the Lawrence County Library for additional information or for
answers to questions that they thought of after the public
meeting.
2. A citizen was concerned that a spring on his property had
not been sampled. He felt that his location was one close
to the vicinity of the Site and should not have been
overlooked.
EPA Response: Several large and small scale maps were shown to
Mr. Cothren on the overhead projector for the purpose of
discerning exactly where the spring he was referring to was
located. In the end, EPA was able to discern approximately where
it was located. . EPA encouraged Mr. Cothren to send in a comment
during the public comment period requesting that his spring be
sampled and to attach a marked copy of the map handout given to
him in the meeting. Mr. Cothren was also told that more detailed
technical information on sampling points and results could be
found in the Site Information Repository located in the Lawrence
County Library. Mr. Cothren was told that his spring could be
sampled either by EPA or TDEC. Jerry Archer of Geraghty & Miller
stated that he believed the reason the spring was not previously
sampled was that it issued from the lower, uncontaminated
aquifer.
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Murray Ohio Dump tut. Site
Record of Decision
Appendix B, Responsiveness Summary
PageS
3. A citizen mentioned concern that fractures beneath the
surface could carry contaminants far off in various
directions. This citizen was also concerned that
contaminated leachate beneath the Site would remain there
after capping.
EPA Response: EPA stated that monitoring points would be placed
around and off the Site to determine if contamination was
migrating via fractures and where. EPA stated that any
contaminated leachate had probably exited the aquifer via seeps
into Northeast Branch.
4. A gentleman and his son stood up with questions concerning
locations of the off-Site ground-water monitoring points on
the maps shown on the overhead and given in handouts. They
wanted to know how the proposed cover systems worked and how
water flowed where it did beneath the ground. The son was
the person who had previously stood up with concerns about
his spring being contaminated.
EPA Response: EPA and Geraghty & Miller clarified locations of
these points to the gentleman's satisfaction. EPA explained that
the caps were meant to divert precipitation, etc.. from
infiltrating down into the waste and carrying out leachate via
ground-water seeps. EPA also explained that underground water
flowed via pressure differences and therefore ended up in
Northeast Branch. EPA and Geraghty & Miller again explained that
his spring came from a formation below that of the contaminated
one and that impermeable layers of rock between the two
formations would cause contaminated ground water to flow out as
seeps into Northeast Branch.
5. The same gentleman and his son had more questions concerning
the hydrogeologic characterization of the Site. They
related a point where Northeast Branch went underground and
pointed to it on a map, questioning if EPA had accounted for
this.
EPA Response: EPA stated that monitor well 10A covered the area
where Northeast Branch went underground. EPA also explained that
Northeast Branch and the other streams in the vicinity of the
Site were seasonal streams and that sampling was therefore
performed at different times of the year to get a complete
picture of the contamination.
6. A question was asked regarding the half-lives of chromium
and nickel, i.e., if they would break down into anything
else in the future.
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Murray Ohio Dump NPL Site
Record of Decision
Appendix B, Responofene** Summary
Page 6
EPA Response: EPA's toxicologist stated that since chromium and
nickel were elements, they could not be broken down any further.
EPA stated that the solution was dilution - lowering the
concentrations to acceptable values - and also explained due to
various parameters such as Ph and soil properties, that it was
very difficult to say with any certainty how long the dilution
process would take.
7. A question arose concerning the City Landfill which is
adjacent to the Murray Ohio Site and the dumping of waste by
Murray Ohio Mfg. at this Site.
EPA Response: EPA explained that the small stream, Southeast
Branch, that runs between the two Sites was sampled as part of
the RI. Results were evaluated and the remedy will address any
problems in the Southeast Branch. EPA also stated that its Site
Assessment section was currently evaluating the City Landfill and
offered to give the citizen a contact to whom he could ask
questions about the City Landfill.
8. Another citizen voiced concern about children possibly
playing in the downwash area of the City Landfill and seeps
from it.
EPA Response: EPA requested that the citizen send in a written
comment and again said it would give the citizen a toll free
number after the meeting where he could call and report this to
Site Assessment.
Part II: Comprehensive Response to Specified Legal and Technical
Questions
Comments Made By PRPs in the March 29, 1994, Letter to EPA
The only legal and technical questions received were those in the
March 29, 1994, letter to EPA from Geraghty & Miller, Inc., on
behalf of Murray Ohio Mfg. This letter can be found in the
administrative record for the Murray Ohio Site. Following is a
summary of the major questions and concerns raised in this letter
and EPA's responses. EPA has attempted to address each issue in
the order found in the letter; however, some skips may exist
where questions cross-reference others, or two questions in
different places in the letter relate directly to one another.
In general, the PRPs agreed with EPA's selected remedy for the
Site but had the following concerns, listed with EPA's responses:
1. The PRPs stated that construction work required to construct
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Murray Ohio Dump KPL Site
Record of Decision
Appendix B, Responmtoenes* Summary
Page 7
the contingent seep collection and treatment system would
destroy the upper reaches of Northeast Branch. The PRPs
also proposed modifying the monitoring period for
determining the necessity of the seep measures from 4
quarters (one year) to 20 quarters (5 years).
EPA Response: EPA felt that 20 quarters was excessive and
instead included a compromise in Section X of the ROD. This
consisted of making the evaluation for the seep measures part of
the five-year review process. The first five-year review can
occur at any time before five years from the date of construction
commencement with successive five-year reviews at intervals of no
longer than five years thereafter. In this way, data can be
evaluated quarterly as it is generated, thus allowing for a more
appropriate time (chosen by EPA) to make the determination for or
against additional construction for seep controls.
EPA is also concerned with possible damage to the Northeast
Branch environs, which is exactly the area which the remedy seeks
to protect. The five-year review measures should eliminate
making a decision on a firm date when concentrations may well be
declining towards and near reaching acceptable levels. The seep
contingency portion of the selected remedy will only be invoked
if after quarterly monitoring in what EPA deems a reasonable time
frame, it appears that levels of contaminants are not close to
reaching acceptable levels.
Measures for restoring Northeast Branch and its surroundings have
also been incorporated into Section VIII of the ROD for the event
that the seep construction is necessary.
2. The PRPs asserted that without the seep contingency
measures, Maximum Contaminant Levels (MCLs) and Ambient
Water Quality Criteria (AWQC) would be eventually achieved
over time.
EPA Response: Perhaps these levels would be achieved eventually
over some period in geologic time, but maybe not in a time frame
which EPA deems reasonable for protecting human health and the
environment. This is why the contingent seep control and
collection measures are included.
3. The PRPs asserted that implementation of the seep
contingency could harm the health and safety of the
community during operation of an on-Site treatment system.
EPA Response: EPA agrees that there are some risks associated
with these measures, but these risks are very slight indeed, if
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Murray Ohio Dump NPL Site
Record of Decision
Appendix B, Responsiveness Sunumvy
PageS
proper management measures are taken.
4. The PRPs asserted in Section 2.0 of their letter that RCRA
closure requirements are not applicable to the entire Post-
1973 area of the landfill, but only to the unit or area of
contamination (AOC) which received waste after 1980. They
also asserted that all technical standards set forth in
various RCRA guidance manuals for landfill closure need not
be rigidly followed.
EPA Response: RCRA defines the "unit" differently than CERCLA.
This is a CERCLA facility and for CERCLA purposes, a landfill is
considered to be one "unit". Therefore, RCRA regulations set
forth in Section IX of this document are applicable to the post-
1973 area of the landfill and relevant and appropriate to all
other areas.
EPA agrees that technical guidance documents are "To be
considered" or TBC materials and has stated this in Section IX of
the ROD. These TBC technical guidance manuals were only used in
the Feasibility Study for the purpose of a general, worst-case
estimate for comparing the cost of the various remedies with an
upgraded cap required for the Post-1973 area of the landfill. No
attempt was made to give exact design numbers.
5. The PRP asserts in Section 2.3.5 of the letter that the
existing cover over the post-1973 disposal area currently
meets all requirements of RCRA Subtitle C.
EPA Response: There are several reasons why this cover does not
meet RCRA Subtitle C requirements. First, it does not comply
with the provisions in 40 CFR, 265.310 (a)(1) and (a)(3) which
state that, "the final cover must be designed and constructed to
provide long term minimization of migration liquids through the
closed landfill" and "...promote drainage and minimize erosion of
abrasion of the cover." EPA has on various trips out to the Site
observed the post-1973 area of the cover to be hummocky and
cracked in spots, a condition which certainly does not minimize
migration of liquids through the landfill. This area of the
landfill also has a slope which is too steep and will result in
erosion of the cover, if the grade is not decreased. For the
above-mentioned reasons, the cover also will not comply with
265.310(a)(4), which states, "...accommodate settling and
subsidence so that the cover's integrity is maintained".
6. The PRP asserts in Section 2.4 that the existing cover over
the post-1973 disposal area meets RCRA Subtitle D
requirements.
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Murray Ohio Dump KPL Site
Record of Decision
Appendix B. Raponstoeness Summary
EPA Response: RCRA Subtitle C is the ARAR which applies here.
Subtitle D is not an issue.
7. Geraghty & Miller was dissatisfied with the level of detail
provided by EPA in the FS for the estimation of additional
costs to the PRP to perform cap improvements for Alternative
#7 (the selected remedy) and Alternative #8. Both of these
alternatives involved improvements to the post-1973 area of
the cap beyond what Geraghty & Miller had included in the
FS.
EPA Response: When EPA took back the FS after two drafts by
Geraghty & Miller, a general estimate of the cost, of the
additional work required for compliance with ARARs was needed to
prepare any PRPs signing on to pay for Remedial Design/Remedial
Action for a worst-case scenario and to provide the public with
sufficient information to allow for informed public comment.
Estimates were made as per practical experience and the TBC
guidance, "Covers for Uncontrolled Hazardous Waste Sites",
EPA/540/2-85/002. To reiterate, the additional figure of
$1,216,400 is a worst-case scenario for cost estimation purposes
only. No attempt was made to give any exact design numbers or
parameters. These will be obtained during Remedial Design.
D. REMAINING CONCERNS
EPA is unaware of any remaining concerns.
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Murray Ohio Dump ItPL Site
Record of Decision
Appendix B, Responsiveness Summary
Page 10
ATTACHMENT A - COMMUNITY RELATIONS ACTIVITIES AT MURRAY OHIO DUMP
SUPERFUND SITE
Community relations activities conducted for the Murray Ohio Dump
Site have included:
* Distribution of an RI/FS kickoff fact sheet (August 1990)
* Community interviews (June 1990)
* An RI/FS kickoff public meeting (August 1990)
* Distribution of a proposed plan fact sheet (February 1994)
* A proposed plan public meeting in Lawrenceburg to record
comments by the public, including potentially responsible
parties (March 1994)
* Phone calls to various members of the community throughout
the RI/FS to address their various concerns
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Appendix C
Rislc Assessment Certification
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RISK ASSESSMENT CERTIFICATION
The Region IV risk assessment staff has reviewed the PRP-
generated risk assessment for the Murray Ohio Disposal NPL Site,
Lawrenceburg, TN for compliance with current Agency health risk
guidance and policy. Comments were conveyed to the Potential
Responsible Parties (PRP) through the Remedial Project Manager
and changes/corrections have been incorporated into a revised
risk assessment document. An addition to this BRA was developed
by EPA as a supplemental Baseline Risk Assessment provided in
appendix C of the FS report. In accordance with the requirement
of OSWER Directive No. 9835.15 (8/28/90), it has been determined
that the final risk assessment including the EPA supplement as
summarized in the Record of Decision conservatively conveys the
upperbound cancer and the systemic toxicity human health risk
posed through all reasonably likely current and future exposure
scenarios and the ecological risks by contaminants identified at
this site. Therefore, it is acceptable to the Agency.
ELMER W. AKIN, CHIEF
OFFICE OF HEALTH ASSESSMENT
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