United States Office of
Environmental Protection Emergency and
Agency Remedial Response
PB93-964204
EPA/ROD/R06-92/072
September 1992
£EPA Superfund
Record of Decision:
Fourth Street Abandoned
Refinery, OK
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NOTICE
The appendices listed in the index that are not found in this document have been removed at the request of
the issuing agency. They contain material which supplement but adds no further applicable information to
the content of the document All supplemental material is, however, contained in the administrative record
for this site.
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50272-101
REPORT DOCUMENTATION i. REPORT NO. 2.
PAGE EPA/ROD/R06-92/072
4. Tide and Subtitle
SUPERFUND RECORD OF DECISION
Fourth Street Refinery, OK
First Remedial Action - Final
7. Author(«)
9. Performing Orgalnizason Nam* and Addrss*
12. Sponsoring Organization Nun* and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
3. Recipient's Accession No.
5. Report D»te
09/28/92
6.
•. Performing Organization Rapt No.
10. Proiect/Tsek/Work UnH No.
11. Corrtract(C) or Gr*nt(G) No.
(C)
(G)
13. Type of Report * Pwiod Covered
800/000
14.
IS. Supplementary NolM
PB93-964204
16. Abstract (Limit: 200 word*)
The 27-acre Fourth Street Refinery (FSR) site is located in Oklahoma City, Oklahoma.
Land use in the area is mixed industrial and residential. Four schools are located
within a 1-mile radius of the site. Portions of the FSR site have been identified as
wetlands. Since the early 1940's, used oils were collected, stored, re-refined, and
distributed as recycled product. Another Superfund site, the Double Eagle Refinery
(DER), lies about 500 feet southwest of the FSR site. The two adjacent sites contain
very similar waste material since both sites recycled used oil. Contamination from
FSR has contributed to contamination in an area just south of the FSR site, known as
the "Parcel H" area. Sludge generated by the reclamation process was disposed of in
onsite impoundments. Physical dumping also occurred in a landfill area just west of
the Parcel H area, but this waste is not attributable to either the FSR or DER sites.
Operations ceased in the late 1960's or early 1970's. In 1989, EPA notified the
owners to conduct a removal at the site; however, the parties declined. Later in
1989, EPA performed a removal action, which included fencing the site and posting
warning signs. This ROD addresses both onsite and offsite sources of contamination,
including soil, sediment, sludge, debris, and surface water as the source control
(See Attached Page)
OK
17. Document Analyst* a. Descriptor*
Record of Decision - Fourth Street Refinery,
First Remedial Action - Final
Contaminated Medium: debris, sediment, sludge, soil
Key Contaminants: Organics (PAHs, PCBs), metals (arsenic, lead), other inorganics
(asbestos)
b. ktentifi
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EPA/ROD/R06-92/072
Fourth Street Refinery, OK
First Remedial Action - Final
Abstract (Continued)
operable unit. This ROD also focuses on reducing the potential for contaminant
migration to surface water and ground water. A subsequent ROD will address the
potential migration of site contaminants via the ground water and surface water
pathways. The primary contaminants of concern affecting the soil, sediment, sludge, and
debris are organics, including PAHs and PCBs; metals, including arsenic and lead; and
inorganics, including asbestos.
The selected remedial action for this site includes excavating 1,200 cubic yards of the
contaminated material from the Parcel H area and consolidating this onsite along with
other contaminated material; treating approximately 42,000 cubic yards of the
consolidated soil, sediment, sludge, and debris onsite using neutralization of the
acidic waste and stabilization of the lead-contaminated materials; disposal of the
treated wastes to.a permitted landfill; and cleaning, consolidating, demolishing, and
salvaging or removing contaminated equipment, structures, and asbestos, as necessary.
The estimated present worth cost for this remedial action is $6,400,000. There are no
O&M costs associated with the selected remedy.
PERFORMANCE STANDARDS OR GOALS: Soil clean-up levels are established for consolidated
materials that will be stabilized to ensure that leaching does not exceed the TCLP.
Chemical-specific goals for soil correspond to the TSCA clean-up level for industrial
land use, regional guidance for setting remedial goals, and industrial land use for the
FSR site, and include PCBs 25 mg/kg; PAHs 30 mg/kg; and lead 500 mg/kg.
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RECORD OF DECISION
FOURTH STREET REFINERY SITE
OKLAHOMA CITY, OKLAHOMA
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
SEPTEMBER 1992
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DECLARATION
FOURTH STREET REFINERY SITE
Statutory Preference for Treatment
as a Principal Element
is Met and Five-Year Review Not Required
SITE NAMEAND LOCATION
Fourth Street Refinery Site
Oklahoma City, Oklahoma
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for
the Fourth Street Refinery Site (FSR site), in Oklahoma City,
Oklahoma, which was chosen in accordance with the Comprehensive
Environmental Response, Compensation, and Liability Act of 1980
(CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA), and, to the extent practicable,
the National Contingency Plan (NCP). This decision is based on the
Administrative Record for this site.
The State of Oklahoma agrees with the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this
site, if not addressed by implementing the response action selected
in this Record of Decision, may present an imminent and substantial
endangerment to public health, welfare, or the environment.
DESCRIPTION OF THE REMEDY
This Record of Decision (ROD) addresses the source of contamination
both on and off the site, which includes surface sludges,
contaminated waters and sediments, and contaminated soil and
debris. This action is the first operable unit for the FSR site.
The first operable unit will also be referred to as the "Source
Control Operable Unit". A second operable unit for the FSR site
will address ground waters beneath the site in a subsequent Record
of Decision. The second operable unit will be referred to as the
"Groundwater Operable Unit".
This Source Control Operable Unit addresses the principal threat at
the site by neutralizing the acidic sludges thereby reducing the
potential for contaminant migration to surface waters and ground
waters. The principal threat at the DER site is posed by direct
contact and inhalation, and potential for migration of contaminants
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to the ground water. The remedial objectives are to minimize
potential exposure by direct contact or inhalation, and to reduce
the potential for migration of contaminants into the surface waters
and ground waters. This action also addresses the low level threat
at the site by chemically binding the hazardous constituents
together in a matrix which eliminates potential exposure via the
following pathways: inhalation, incidental ingestion, and direct
contact.
The major components of the selected remedy include:
• Cleaning, consolidation, demolition as necessary, and salvage or
removal of contaminated equipment and structures on-site, in order
to implement the remedial components specified below;
• Consolidation of off-site and on-site wastes (an estimated volume
of 42,000 cubic yards of contaminated material) onsite;
• On-Site neutralization of the consolidated acidic wastes;
• On-Site stabilization and solidification of waste containing
lead;
• Off-site disposal of the treated waste in a landfill permitted to
accept the waste.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that are
legally 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, or
volume as a principal element.
Because - this remedy will not result in hazardous substances
remaining on site above health-based levels, no review will be
conducted within five years after commencement of remedial action
to ensure that the remedy continues to provide adequate protection
of public health, welfare, and the environment.
B. J. Wynne Date
Regional Administrator
Region 6
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CONCURRENCE DOCUMENTATION
FOR THE
FOURTH STREET RECORD OF DECISION
Site/remedial Project Manager
Office fff. Regional Counsel
Site Attorney
Carl Edlund, Chief
Superfund Programs Branch 6H-S
o<5george/Alexanderri Jr.
r Regional Counsel 6C
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FOURTH STREET REFINERY
RECORD OF DECISION
TABLE OF CONTENTS
I. Site Name, Location, and Description 1
II. Site History and Enforcement Activities 6
A. Site History 6
B. Enforcement Activities 7
III. Highlights of Community Participation 8
IV. Scope and Role of Operable Unit 1 9
V. Summary of Site Characteristics 9
A. General Overview 9
B. General Geology and Hydrogeology Characterization... 10
C. Site Hydrogeologic Conditions 12
D. Nature and Extent of Contamination 12
E. Discrete Areas of Contamination 13
1. Tar Mat Area 13
2. Surface Impoundments 16
3. Drainage Pathways 17
4. Parcel H 17
VI. Summary of Site Risks 17
A. Human Health Risks 17
B. Land Use 18
1. Current Land Use 18
2. Future Land Use 19
C. Identification of Chemicals of Concern 20
D. Exposure Assessment 20
1. Current Exposure Pathways 20
2. Future Exposure Pathways 22
3. Exposure Scenarios 26
E. Toxicity Assessment 28
F. Human Health Risk Characterization 30
1. Current Risk Characterization 32
2. Future Risk Characterization 32
G. Central Tendencies 35
H. Uncertainties with the Human Health Risk
Calculations 35
I. Ecological Risks 42
1. Receptor Characterization and Endpoints 43
2. Toxicological Response Assessment 44
3. Exposure Assessment 44
4. Risk Characterization 44
VII. Remedial Action Goals 45
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VIII. Description of Alternatives 46
A. Remedial Action Alternatives 47
1. Common Elements 47
2. No Action 48
3. Limited Action 48
4. Onsite Stabilization and Capping 49
5. Onsite Stabilization/Onsite Landfill Disposal... 53
6. Onsite Stabilization/Offsite Landfill Disposal.. 55
7. Onsite Incineration/Onsite Ash Disposal 56
8. Off site Incineration/Off site Ash Disposal 57
IX. Summary of Comparative Analysis of Alternatives 59
A. Nine Criteria 59
1. Threshold Criteria 59
2. Balancing Criteria 59
3. Modifying Criteria 60
4. Comparative Analysis 60
X. The Selected Remedy 64
XI. Statutory Determinations 66
A. Protection of Human Health and Environment 66
B. Compliance with ARARs 66
C. Chemical Specific ARARs 66
D. Action Specific ARARs 67
E. Cost Effectiveness 67
F. Utilization of Permanent Solutions and Treatment.... 67
G. Preference for Treatment as a Principal Element 68
XII. Documentation of Significant Changes 68
Administrative Record Index Attachment A
Responsiveness Summary Attachment B
Letter of State of Oklahoma Preference Attachment C
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DECISION SUMMARY
FOR THE
FOURTH STREET REFINERY SITE
OKLAHOMA CITY, OKLAHOMA
I. SITE NAME. LOCATION. AND DESCRIPTION
The Fourth Street Refinery Superfund Site ("FSR site", or "the
site") occupies the Southwest Quarter (SW 1/4) of Section 36,
Township 12 North, Range 2 West and Range 3 West, Indian Meridian,
Oklahoma County, Oklahoma City, Oklahoma. Located at 1900 NE First
Street, the site is bounded to the south by the Union Pacific
Railroad tracks, to the north by Northeast Fourth Street, and to
the east by Interstate 35. Martin Luther King Boulevard lies on
the west side of the site as an overpass to the railroad tracks.
Two active industrial facilities (which have not been associated
with past site operations) also lie contingent to the mid-northern
portion of the site, just south of Northeast Fourth Street.
The Double Eagle Refinery Site ("DER site1*) lies about 500 feet
southwest of the FSR site, just south of the railroad tracks and
just west of Martin Luther King Boulevard. The FSR and DER sites
are essentially adjacent to each other, and contain very similar
waste material since both sites recycled used oils. Due to the
fact that these sites are in such close proximity and migration of
contaminants in certain cases overlap, this Record of Decision
(ROD) will make reference to the DER site as necessary. The DER
site will be addressed in a separate ROD. Figures 1 and 2 show the
location of each site in relation to the other.
The FSR site extends over three contiguous tracts of land, two
tracts fenced and one tract unfenced, totaling approximately 27
acres. An active industrial facility is currently operating on the
westernmost tract, which is part of the original refinery property,
but is now owned and operated by a separate individual. This tract
is fenced and will be referred to as the Pipe Storage Yard,
consistent with the active facility's current operations. The Pipe
Storage Yard contains buried sludge material beneath the site,
which is presently covered with gravel. The middle tract of the
site is also fenced and contains the majority of contaminated
material, a large tar mat area and surface ponds. This tract will
be referred to as the Main Site Area, consistent with the fact that
most of the contaminated material and scattered debris can be found
on this tract. The eastern tract of land is unfenced and contains
only surficial contamination carried from the Main Site Area via
surface drainage. This tract will be referred to as the Eastern
Drainage Area.
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OKLAHOMA
Fourth Street | Site L
louble Eagle SJte
NOT TO SCALE
FIGURE 1
Double Eagle and Fourth Street
Superfund Sites,
Oklahoma City, Oktahaona
FLUDR DANIEL
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The Pipe Storage Yard and the Main Site Area were once the former
operations area, as evidenced by historical aerials and the
extensive piping network discovered during investigations at the
site. The gravel/sand cover in the Pipe Storage Yard has been
ineffective in covering buried contaminated sludges; consequently,
surface seeps are now apparent. The Main Site Area contains
several discrete areas of concern: a tar mat area, two smaller
earthen impoundments, one small concrete sump, and numerous pieces
of abandoned refinery equipment and debris from past uncontrolled
dumping. Remnants of the dismantled refinery in the Main Site Area
include a warehouse foundation, three horizontal tank stands and
foundations, an oil well, and an abandoned concrete oil well
derrick foundation. Figure 3 is a schematic of the FSR site which
shows the surface features and areas of contamination.
Although industrial areas surround the site, the land use within a
1 mile radius of the FSR site is mixed industrial and residential.
One residence is located adjacent to the Pipe storage Yard, just
north of the railroad tracks and to the east of Martin Luther King
Boulevard. A small neighborhood is located about 1/4 mile to the
northwest of the Martin Luther King Boulevard and Northeast Fourth
Street intersection. Four schools (Douglas High School, Dunbar
School, Bath School, and Edwards School) are located within a 1
mile radius of the site. Recreational areas close to the site
include the Douglas Community center, Douglas Community Park, and
Washington Park. Drug Recovery, Inc. is the only medical facility
located within a 1 mile radius of the site.
The FSR site has contributed to off-site contamination in an area
just south of the site, the "Parcel H Area". This off-site area is
unfenced. The contamination at the Parcel H Area which is
attributable to past site operations includes two surficial ponds,
approximately 0.5 acre. The Parcel H Area is shown in Figure 3.
The "Landfill Area" in this figure, located just west of the ponds
on Parcel H, is not attributable to either the FSR or DER site past
operations.
Both portions of the FSR site and the Parcel H Area have been
identified as wetlands. The North Canadian River is located just
south of Interstate 35, approximately one-half mile south of the
site. Although no endangered species have been identified in these
areas, wildlife in the area includes migratory fowl and small
mammals.
No drinking water wells are located within a 1 mile radius of the
site. The oil well drilling operations in the early 1920's may
have impacted the alluvial aquifer. This zone could be considered
a Class III aquifer due to salinity, since the shallow ground water
beneath both the FSR and DER sites has levels of Total Dissolved
Solids ranging from 310 to 13,100 ppm.
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The interconnection between the shallow alluvium and the
deeperdrinking water aquifer (Garber-Wellington) is currently
undergoing further study for both the FSR and DER sites. In
addition, the alluvium connection and potential impact of site
contaminants to the North Canadian River will need further
evaluation. A separate Record of Decision (ROD) will address the
potential migration of site contaminants via the ground water
pathway for the FSR site as Operable Unit 2.
n. SITE HISTORY AND ENFORCEMENT ACTIVITIES
Site History
The Fourth Street Refinery collected, stored, and re-refined used
oils and distributed the recycled product. The refinery was active
in the early 1940's and was noted on historical aerial photographs
available as early as 1941. Refining operations were conducted on
land owned by the Chicago, Rock Island and Pacific Railway Company.
Planet Oil and Refining Company participated in the waste oil
reclamation business during the early part of the 1940's through
the early 1960's. Elliot Refining Company conducted waste oil
reclamation activities during the late 1940's through the 1960's.
Salyer Refining Company performed waste oil reclamation operations
from the late 1940's through the 1960's. These three companies
conducted waste oil reclamation activities on-site. Operations
ceased in the late 1960's or early 1970's. Currently, exposed
underground pipes at many locations on-site indicate that an
extensive piping network was utilized during operations.
Refinery operations at the FSR site apparently recycled used oils
in a similar manner to that process employed at the DER site.
Sulfates in the waste suggest the use of sulfuric acid in
clarification of the used oils. Sludges generated by the
reclamation process were disposed of in on-site impoundments.
A preliminary assessment of the site was completed in April, 1984,
and a reconnaissance site inspection was conducted in October,
1984. Subsequent sampling was performed in June and December of
1985, in the Main Site Area. Further sampling was conducted in
1986 along with the installation of ground water monitoring wells.
An Expanded Site Inspection was conducted in 1987 through 1988,
which confirmed that the site should be ranked for inclusion on the
National Priorities List (NPL). In March 1989, the FSR site was
added to the NPL, pursuant to Section 105 of the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA),
42 U.S.C. Section 9605, as amended.
Prior to initiation of the Remedial Investigation and Feasibility
Study (RI/FS) projects for both the FSR and DER sites, review of
the historical topography of the surrounding area revealed that
drainage from the DER site onto Parcel H had occurred at one time.
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A site scoping visit was conducted to follow up on possible Parcel
H contamination. Although drainage from the FSR site to Parcel H
did not appear likely due to the diking on each side of the
railroad tracks, historical aerials were the only source of
information for the FSR site operations.
Physical dumping at the edge of the eastern-most pond on Parcel H
appeared to have occurred. Further sampling conducted on Parcel H
in April of 1990 revealed elevated levels of lead in the sediments
of ponds on Parcel H. Due to the similar waste characteristics of
both sites, one objective of the RI/FS was to sample the waste on
Parcel H for determining the contribution of contamination in
relation to either, or both, the FSR and DER sites.
The RI/FS project was initiated in May 1990 for the FSR site. The
RI and FS reports were completed in Hay 1992 and June 1992,
respectively. Due to the close proximity of the FSR and DER sites
and due to the similar types of wastes present at both sites and at
the Parcel H Area, EPA assigned one contractor to conduct the RI/FS
projects concurrently. Therefore, distinguishable characteristics
of each site could be easily identified and efforts would not be
duplicated for the overall study area. The specialized
"fingerprinting effort" for the off-site areas was performed by
EPA's Environmental Monitoring Systems Laboratory in Las Vegas,
Nevada, in coordination with the Alternative Remedial Contractor
(ARCS) given the RI/FS project. This will be discussed further in
Section V - Summary of Site Characteristics; Discrete Areas of
Concern.
Enforcement Activities
In July, 1989, General Notice Letters were sent to the three (3)
current owners of the FSR site. The General Notice Letters
informed these parties that they may be responsible for future
response measures taken at the site. These parties were afforded
the opportunity to conduct the removal at the FSR site; however,
the parties expressed an unwillingness to perform or finance the
removal -action. In September 1989, EPA performed the removal
action which included fencing the site and posting warning signs to
alarm potential trespassers.
In October, 1989, Special Notice of Potential Liability Letters
were sent to the current owners affording them the opportunity to
conduct the RI/FS at the FSR site. The current owners declined to
participate in either the financing, or the actual performance of
the RI/FS.
Later, in 1990, the RI/FS project was initiated by EPA, and has
been completed. Simultaneously with the performance of the RI/FS,
EPA proceeded to collect liability information regarding the
contamination at the site. Currently, the Potentially Responsible
Party search investigation is ongoing.
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ffl. HIGHLIGHTS OF COMMUNITY PARTICIPATION
This decision document presents the selected remedial action for
the FSR Superfund site, in Oklahoma City, Oklahoma, chosen in
accordance with CERCLA, as amended by the Superfund Amendments and
Reauthorization Act (SARA) and, to the extent practicable, the
National Contingency Plan (NCP), 40 CFR Part 300. The decision for
this site is based on the administration record. An index for the
administative record is included as Attachment A to this document.
The public participation requirements of CERCLA, sections
113 (k) (2) (B) (i-v) and 117, were met during the remedy process. The
Remedial Investigation (RI) report, released in May 1992, the
Feasibility Study (FS) report, released in June 1992, and the
Proposed Plan, released in July 1992, were all made available to
the public in both the administrative record and information
repositories maintained at the Ralph Ellison Branch Library, the
OSDH Central Office in Oklahoma City, Oklahoma, and the EPA Region
6 Office in Dallas, Texas. The notice of availability for these
documents was published in The DailyOklahomian and The Black
Chronicle, on July 17, 1992.
The OSDH and EPA held an Open House in Oklahoma City on August 4,
1990, to explain the Superfund process and to notify the public
that RI activities were going to begin. The RI fieldwork was
discussed and information about the site was provided to the public
by EPA.
On June 25, 1992, the OSDH and EPA held an Open House in Oklahoma
City, to inform the public of the findings of the RI Report which
included the results of the Baseline Risk Assessment. EPA and OSDH
also discussed the various alternatives of remediation considered
in the RI/FS.
A 30-day public comment period was held from July 17, 1992 to
August 15, 1992. No requests were received to extend the comment
period. One (l) written comment was received during the public
comment period.
A public meeting was held in Oklahoma City on July 23, 1992. At
this meeting, representatives from the OSDH and EPA presented
information on the RI/FS, and the Risk Assessment (RA); and
answered questions about the site, the remedial alternatives under
consideration, and the Proposed Plan of Action. A response to the
comments received at this meeting and during the 30-day period is
included in the Responsiveness Summary, which is as Attachment B to
this ROD.
8
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IV. SCOPE AND ROLE OF OPERABLE UNIT 1 WITHIN THE SITE STRATEGY
Principal threat wastes are those source materials considered to be
highly toxic or highly mobile that generally cannot be reliably
controlled and that present a significant risk to human health or
the environment should exposure occur. The principal threats at
the FSR site are the acidic sludges and contaminated ponds. These
discrete waste areas present the most significant risk at the site,
due to the potential for exposure through, direct contact and
inhalation. The risk is also increased due to the concentrated
nature of the waste which presents a high potential for migration
of contaminants to surrounding areas and the underlying ground
water.
Low level threats are those source materials that generally can be
reliably managed with little likelihood of migration and that
present a low risk in the event of exposure. The low level threats
at the site are the contaminated soils and tar matrices, both on
and off-site. These areas are not as highly mobile as the acidic
sludges and the material in the ponds on-site and the concentration
of contaminants is more dilute which decreases the risk from
potential exposure.
The principal threat at the FSR site is posed by direct contact and
inhalation, and potential for migration of contaminants to the
ground water. The remedial objectives are to minimize potential
exposure by direct contact or inhalation, and to reduce the
potential for migration of contaminants into the surface waters and
ground waters.
During the RI/FS project for the FSR site, the issues related to
the ground waters beneath the site were acknowledged as complex in
comparison to those issues apparent for the source contamination.
Although shallow and deep we 14s were installed around the perimeter
of both the FSR and DER sites, the determination of vertical and
lateral migration of contaminants will require further study. The
impact of the migration of contaminants in ground water and surface
water will be addressed in a future Record of Decision, Operable
Unit 2 (Groundwater Operable Unit - GOU). This ROD will address
the source of contamination at the DER site, Operable Unit 1
(Source Control Operable Unit - SCOU).
V. SUMMARY OF SITE CHARACTERISTICS
General Overview
The FSR site and Parcel H Area are not located in the 100 year
floodplain. Prior to construction of Interstate 35, the North
Canadian River meandered through the FSR site. During construction
of the highway, the river was diverted to the south side of 1-35,
and is now located approximately one half-mile to the south of the
FSR site.
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Ponds on the FSR site and portions of the Parcel H Area appear on
the National Wetlands Inventory Maps (NWI) (U.S. Dept. of Interior,
Fish and Wildlife Service, 1989). These maps are based on
interpretation of aerial photographs and not on actual site
surveys. Vegetation around open water areas in the Eastern
Drainage Area and on Parcel H appear to consist of grasses, likely
to be prairie grass species rather than wetlands species. Wetlands
classification of the FSR site and off-site areas will be discussed
in detail under Section VI (Summary of Site Risks - Ecological
Risks).
General Geology and Hydrogeology Characterization
The FSR site is situated on Quaternary alluvial deposits which
represent recent deposition by the nearby North Canadian River.
The floodplain deposits typically consist of unconsolidated and
interfingering lenses of sand, silt, clay, and gravel. These
alluvial sediments are predicted to have relatively high
permeabilities and porosities. The alluvium in Oklahoma County
ranges in thickness from several inches to 90 feet below ground
surface along the river basin.
The predominant outcropping geologic formation beneath the FSR site
includes the Garber and Wellington Formations. These bedrock
formations (i.e., lithified strata below the alluvial channel fill)
have a gentle westward homoclinal regional dip of 30 to 40 feet per
mile and are located approximately 40 to 60 feet below the surface
at the FSR site. Collectively, the Garber-Wellington consists of
massive, cross-bedded sandstones irregularly interbedded with
siltstones and shales. The "red bed" sandstones and shales of the
Garber and Wellington Formations are similar in lithology and
conform gradationally. Therefore, these formations are commonly
mapped as a single lithologic unit and classified as a single
aquifer (the Garber-Wellington aquifer). See Figure 4 for a cross-
section of the subsurface.
The Garber-Wellington aquifer constitutes the most important source
of ground water in Oklahoma County. Wells drilled into the water
bearing zone may penetrate as much as 200 to 300 feet of water
bearing sandstone. Artesian conditions exist below 200 feet in
areas in which the aquifer is overlain by the Hennssey Group. The
depths of municipal, institutional, and industrial wells screened
in the Garber-Wellington range from 100 to approximately 1,000 feet
in Oklahoma County. Yields of wells less than 250 feet deep range
from 5 to 115 gallons per minute (gpm) and average 35 gpm.
Reported yields of wells more than 250 feet deep range from 70 to
475 gpm and average 240 gpm. The principal hydrologic factor
controlling the development of the aquifer for fresh water supply
is the presence of a deeper saline water wedge.
No private wells currently exist within a 1 mile radius of the
site. Residents and industries in the area utilize city water,
which is obtained from reservoirs surrounding the city. Results
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11
-------
from sampling the shallow ground water beneath both the FSR and DER
sites indicate total dissolved solids from 310 ppm to 13,100 ppm;
high conductivities were also documented, >20,000 milli moles.
These conditions confirm the presence of saline water beneath the
site which would prohibit use of the shallow ground waters for
domestic use.
The Hennessey Group formation, predominantly reddish-brown shale
containing some layers of siltstone and fine-grained sandstone,
overlays the Garber-Wellington Formation in the vicinity of the
site. However, this shale layer was not encountered above the
Garber-Wellington aquifer in the deeper borings drilled at both the
FSR and DER sites in March of 1992. Due to the absence of the
Hennessey Shale beneath the site, a separate study is plannned to
assess the vertical migration and potential impact of site
contaminants on the deeper Garber-Wellington aquifer. In addition,
the lateral migration and potential impact of site contaminants on
the nearby Canadian River will be investigated. The results of
this study will be utilized to complete the ROD for the GOU.
Site HydrogeologicConditions
Field investigations at the Fourth Street Refinery site included
portions of the Parcel H area; and revealed that the upper 1 to 20
feet of surface material consisted of stained soils within a
variable amount of sand, silt and clay matrix. Subsurface strata
consisted of a classic, fining-upwards alluvial sequence of sand
and gravel. At depths ranging from 20 to 32 feet, a dense layer of
medium to coarse-grained sand and gravel in a brick-red matrix was
encountered in several of the borings on the FSR site. This
surface most likely represents the erosional top of the Permian
bedrock.
During drilling operations, groundwater was encountered at varying
depths that ranged from 4.5 to 9.5 feet below the surface.
Subsequent groundwater monitoring indicates that the the
groundwater levels range from about 4 to 12 feet below the ground
surface.. The groundwater levels were determined periodically, and
exhibited moderate seasonal fluctuations.
Nature and Extent of Contamination
The Source Control RI/FS was focused to provide information for
discrete areas of concern and subsequent migration pathways, given
the type of oily matrix encountered at the site. The discrete
areas of concern at the FSR site are well delineated waste areas;
buried waste material beneath the Pipe Storage Yard Area, a tar mat
extending across the Main Site Area, two small earthen impoundments
and one concrete sump in the Main Site Area, various piles of waste
material and debris from the dismantled refinery scattered across
the Main Site Area, and the Eastern Drainage Area. In addition,
the off-site "Parcel H" area was included in the investigation, as
discussed under Section I.
12
-------
Figure 5 is a conceptual model of the site, used for visualizing
the potential exposure pathways of concern. As discussed
previously, the ground water pathway is currently unknown.
Therefore, this pathway is presented as incomplete in the current
conceptual model, but will be evaluated under the GOU ROD.
From all the chemicals detected in various media at the site,
certain chemicals were originally identified as potential
Contaminants of Concern (COC). This determination for selection of
a COC is based upon concentrations detected, toxicity of the
compound, and their persistence in the environment. COCs
attributable to site activities include Polycyclic Aromatic
Hydrocarbons (PAHs), chlorinated hydrocarbons and polychlorinated
biphenyls (PCBs), alkyl benzenes, ketones (particularly 2-
butanone), lead, arsenic, and antimony. Lead is the primary COC
given the widespread occurance in all media and the extremely high
concentrations (approximately 15,000 ppm) in sludge and
contaminated soils or sediments. Exposure to the COCs could
potentially occur due to direct contact as well as inhalation.
The COCs are discussed in Section VI - Summary of Site Risks.
Although the air pathway contributed the greatest risk and hazard
index for organics detected, a trend is not apparant to suggest
that the site contributes to the ambient air contaminant levels of
the surrounding area. This is due to high gasoline constituent
levels measured upwind of both the FSR and DER sites; probably due
to the areas surrounding both sites being highly industrialized.
Similarly, particulate air sampling results for lead were high
(32.8 ug/m3) onsite. However, upwind locations were just as high
(32.0 ug/m3).
Discrete Areas of Concern
a) Tar Mat. Exposed and Buried Areas
Evaluation of the tar mat was completed upon visual inspection of
borings over a 20 by 20 foot surveyed grid system, tied to the
larger 100 by 100 foot surveyed grid system for the entire site
(Figure 6). Samples were collected randomly from the smaller grid,
both laterally and vertically, for full scan analysis (Target
Compound List - TCL) under the Contract Laboratory Program (CLP).
In addition, samples were obtained for indicator parameter analysis
(Total Petroleum Hydrocarbons - TPH; pH; Lead; and Chromium) to
correlate with visual observations and full scan analysis. Also,
technology screening samples were collected (physical parameters
such as density, grain size distribution, solubility, viscosity,
heat content, etc.).
Discrete depth samples were not planned since an initial inspection
of the exposed tar mat prior to the RI/FS Work Plan approval did
not reveal distinguishable differences vertically within the Main
Site Area. However, buried tar material was noted in the form of
seeps in the Pipe Storage Yard Area. Since this matrix appeared
13
-------
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14
-------
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o:
o: ai
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O
CT
L
2
n ni
DNIX a3Him
15
-------
more fluid than the weathered material of the exposed tar mat,
samples obtained for characterization of the waste material were
obtained from both the Pipe Storage Yard Area and the Main Site
Area (areas shown in Figure 3).
Results of this sampling effort show that the chemical composition
of the buried and the exposed tar mat material are not
significantly different. Vertical versus lateral composition did
not vary significantly, either. In general, the correlation
between visual observations and indicator parameters was only
loosely established. However, lead concentrations did increase
with higher TPH content in the sludge matrix and higher acid
content.
In general, the correlation between visual observations and
indicator parameters was only loosely established. However, lead
concentrations did increase with higher TPH content in the sludge
matrix and higher acid content. In the Pipe Storage Yard, waste
material is covered by a thin layer of gravel (approximately 6 to
12 inches). The buried sludge extends across the entire pipe yard
site and has an aerial extent of approximately 150,000 square feet.
In the Main Site Area, the tar mat extends westward towards a
north-south fence line that represents the eastern boundary of the
Pipe Storage Yard. The aerial extent of the tar mat is
approximately 300,000 square feet. However, the western-most and
the eastern-most portions of the tar mat are covered with grass.
The estimated volume of waste material for the exposed tar mat is
26,000 cubic yards and the estimated volume for the buried tar
material is 11,000 cubic yards (total sludge material of 37,000
cubic yards).
b) Surface Impoundments
The two impoundments on-site are not considered very large and were
assumed to be homogeneous in nature and composition. Both of the
earthen impoundments are unlined. The concrete sump is located
just south of Impoundment A, as shown in Figure 3. Therefore, only
one water and one sediment sample were collected from each of the
impoundments and the sump. All samples were analyzed for TCL
compounds and some samples were analyzed for technology screening
parameters.
Water sample results were limited in use due to matrix
interferences in both impoundments. However, results of the
sediment sampling indicated that sediments in the ponds were
similar in chemical composition to that material in the main tar
mat area. The aerial extent of contaminated material in the
impoundments is estimated at approximately 20,000 square feet with
an estimated volume of 400 cubic yards.
16
-------
c) Drainage Pathways
Although the tar mat and ponds on-site were of major concern,
drainage pathway sediments were also investigated. The volume of
contaminated material for drainage areas is estimated as 400 cubic
yards. This includes sediments in the Eastern Drainage Area.
d) Parcel HArea
The contamination at the Parcel H Area includes oily sediments in
two surface ponds, and these sediments which contain high lead
concentrations. The concentrations of lead encountered in the
sludge from the ponds at Parcel H ranged from 199 to 8,780 mg/kg.
The concentrations of lead encountered in the sediments from the
ponds ranged from 5,550 to 19,900 mg/kg. Each pond is
approximately 0.25 acre in size. The volume estimate for
contaminated sediments in both ponds is 2,420 cubic yards, assuming
a 3 foot depth for each pond.
The EPA Environmental Monitoring Systems Laboratory (EMSL) has
evaluated existing data and analyzed samples from both the FSR and
DER sites, and the Parcel H Area. This specialized fingerprinting
effort was intended to confirm whether or not the waste at the
Parcel H Area was attributable to the FSR site and/or DER site.
The results have indicated that waste from FSR is slightly
different in chemical composition than waste from DER. Both sites
have contributed to the Parcel H contamination. Based on the
fingerprinting effort, EPA estimates that 50% of the waste at
Parcel H is attributable to each site and will be addressed as part
of each site remedy.
VI. SUMMARY OF SITE RISKS
Human Health Risks
As part- of the Remedial Investigation at the FSR site, a
quantitative risk assessment was performed to estimate human health
risks from the site. This section presents a summary of the
Baseline Human Health Risk Assessment for exposure of humans to
contaminants existing within areas of concern at the FSR site and
a non-contiguous area referred to as the Parcel H area.
This ROD does not address the potential contamination of
groundwater due to site-related activities. The shallow aquifer
may be classified as a Class III aquifer (water not suitable for
human consumption). This pathway of potential contamination and
the possible human health effects which could result from exposure
is being evaluated, and will be addressed separately by the GOU.
The purpose of the risk assessment was to compile and evaluate
information collected in the site investigation in order to
17
-------
estimate the upper limit of potential health risk which may be
present at the site. In the evaluation of potential human exposure
scenarios, on-site sampling and analysis results were used in
conjunction with current federal and state guidance documents and
professional judgement to estimate the potential human health risk
attributable to contamination resulting from past site-related
operations.
The "risk" values generated within this human health risk
assessment will reflect the plausible upper limit to the actual
risk of cancer posed by the site under the exposure scenarios
evaluated. These estimates were compared to the EPA's target risk
range of l X 10~* to 1 X 10"6 for hazardous waste site remediations.
The NCP stipulates a 1 X 10"6 risk level as a point of departure in
risk management. Such estimates, however, do not necessarily
represent an actual prediction of the risk. Non-carcinogenic
impacts are quantified by the "Hazard Index" which is the ratio of
site concentrations of a contaminant of concern to a reference
concentration that causes a non-carcinogenic impact. EPA's
remedial goal is to reduce the "Hazard Index" at a site to less
than 1.0.
The values which are calculated in this assessment are considered
representative of the cancer risk posed by the site only in that
they represent estimates of the plausible upper bound limit of what
is most probably the risk range. The true risk within the range of
the upper limit and zero is indeterminable. What is estimated is
the projected reasonable maximum potential additional lifetime
cancer risk and potential for adverse health effects. The
reasonable maximum potential risk is calculated in order to be
health protective ("health protective" assumptions are also
referred to as "conservative" assumptions in risk assessment
terminology). It should be noted that the risk is an additional
risk - it is present in addition to the baseline approximate "1 in
3" chance which humans share of "getting cancer".
Land Use
a) Current Land Use
The former FSR site is located near the intersection of northeast
Fourth Street and Martin Luther King (MLK) Boulevard. The immediate
area of the site, the eastern drainage area and Parcel H are zoned
for industrial use. To the west of the FSR site is a residence and
a convenience store. Further to the west are industrial facilities
including an insulation plant and an operating waste oil
reclamation refinery.
North of the site is a residential area within which are parks and
schools. Portions of the residential area, parks and schools are
within one mile of the site as previously described in this risk
assessment. The residents living in these areas may be exposed to
contaminants in the on-site waste areas via atmospheric transport.
18
-------
Some of the residents may also gain unauthorized access to the site
and could be exposed in a manner similar to transients. Access to
Parcel H and eastern drainage areas are not controlled since they
are not fenced.
The potential for trespass in this general area is substantial,
since the site is situated in the immediate area of the MK&T
multi-track railway line. There are two major interstate freeways
nearby (1-35 and 1-40). These thoroughfares may increase the
prevalence of transients in the area. Transients have been observed
loitering under the bridge which carries MLK Boulevard over the
MK&T railway lines. There are also signs such as gathered firewood
that may indicate "camping" in good weather under the MLK Boulevard
bridge. In addition, the close proximity to a residential area
suggests that children may visit the Parcel H and eastern drainage
areas during play activities.
The FSR site and adjacent areas are, for the most part, vacant
(i.e., authorized personnel work in the Pipeyard for only part of
the day). Therefore, there is significant potential for transients
and trespassers to be exposed to contaminants in the waste areas.
Pipeyard operations may also create a potentially-exposed
population of on-site workers.
The nearest major surface water body is the North Canadian River,
which is located approximately one half mile south of the site. The
river is on the far side of the raised freeway with no apparent
hydraulic connections with surface drainage features from the site.
b) Future Land Use
Given the current land use patterns, the Fourth Street site is
likely to remain an industrial facility. Two possible scenarios of
usage, not considering remediation of the site, are possible. They
are:
The Pipeyard remains with no change in the existing tar
. mat and impoundments in the undeveloped section of the
site.
The Pipeyard remains; new structures are built; and,
workers are present in the tar mat area in a normal
working environment. Even though this is not likely
unless the waste areas are remediated, this scenario will
still be evaluated because it represents a reasonable
possible scenario.
The future use and development of the Parcel H area is somewhat
more uncertain as any development is likely to depend on
remediation of the waste area as well as the "landfill/rubbish"
area. Because the land use surrounding Parcel H is commercial, EPA
expects future land use at Parcel H to be commercial. Future
commercial development at the eastern drainage area is likely.
19
-------
In the proposed future use scenarios, it assumed that no specific
remediation of the waste material will occur and that industrial
and construction workers will be exposed to the waste material in
each area.
Identification of Chemicals of Concern
The initial Chemicals of Concern (COCs) were the contaminants on
site which were identified as most likely to contribute significant
cancer risks and non-cancer health effects, and to cause a public
health concern. The risk assessment focused on contaminants that
were site-related, but a chemical was included if it materially
contributed to the overall public health impact. Factors such as
frequency of detection, exposure point concentration and human
toxicity dictated which COCs contributed most to the potential
human health risk from exposure to a particular medium of concern.
The FSR site was an oil reclamation plant. As such, the major COCs
were expected to be oil-derived contaminants and other materials
(such as lead) associated with motor vehicle products. In general,
the initial COCs were related to this process. Table 1 lists the
initial COCs, and the media in which they were detected. However,
only a few of the chemicals originally identified actually drove
the risk at the FSR site. These specific chemicals will be
discussed later in this Section, Human Health Risk
Characterization.
Exposure Assessment
a) Current Exposure Pathways
The following is a summary of the selected exposure pathways for
the current use of the FSR site and the surrounding areas:
Oral/dermal exposure of on-site Pipeyard workers to
contaminants in the sludge present in the soils;
Inhalation exposure of the on-site Pipeyard workers to
volatilized contaminants or to particulates carrying
contaminants;
Oral/dermal exposure of trespassers in the tar mat area
to the contaminants in the sludge present in the
impoundments, tar mat and soil;
Direct exposure of trespassers in the tar mat area to
contaminants present in the surface water of the
impoundments through accidental exposure;
Inhalation exposure of the trespassers in the tar mat
area to volatilized contaminants or to particulates
20
-------
TABLE
Initial
Fourth Street Site
Contaminants of Concern
Compound
Tar Mat
Soil
Pipeyard
Soil
Off-
site
Soil
Off-site
Hot Spot
CARCINOGENS
Arsenic
Cadmium
Beryllium
Benzene
Tetrachloroethylene
Trichloroethylene
Methylene Chloride
Phthalates
PCBs
Styrene
FAHs
Heptachlor
Chlordane
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
NON-CARCINOGENS
Antimony
Barium
Copper
Lead
Nickel
Thallium
Vanadium
Zinc
Ketones
Alkyl Aromatics
1,1, 1-Trichloroethane
Polychlorobenzenes
Phenols
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Tar Hat
Surface
Water
Off-
site
Surface
Water
Air
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
21
-------
carrying contaminants;
Oral/dermal exposure of transients to the
contaminantspresent in the areas of concern (hot spot) in
the Parcel H and eastern drainage areas;
Oral/dermal exposure of transients to the contaminants
present in the soil/sediment surrounding the site, in the
Parcel H and in the eastern drainage areas;
Direct exposure of the transients to contaminants present
in the surface waters of the Parcel H area impoundments
through accidental exposure;
Inhalation exposure of the transients to volatilized
contaminants or to particulates carrying contaminants
while in the vicinity of the Fourth Street site or in the
Parcel H and in the eastern drainage areas; and,
Inhalation exposure of children to volatilized
contaminants and/or to particulates carrying contaminants
in the ambient air while in the vicinity of the pool and
the high school.
Table 2 lists the exposure and intake assumptions for dermal
contact and ingestion of surface soil/sludge and surface water, for
the current use scenario. Table 3 lists the exposure and intake
assumptions for inhalation, for both the current and future use
scenarios.
b) Future Exposure Pathways
The following is a summary of the selected exposure pathways for
the future use of the FSR site and the surrounding areas:
'• . Oral/dermal exposure of Pipeyard workers to contaminants
present in the soils;
Inhalation exposure of the Pipeyard workers to
volatilized contaminants and/or to particulates carrying
contaminants;
Oral/dermal exposure of on-site workers to contaminants
present in the sludge and in the impoundments, tar mat
and the soil of the tar mat area;
Direct exposure of on-site workers in the tar mat area to
contaminants present in the surface water of the
impoundments through accidental exposure;
Inhalation exposure of the on-site workers in the tar mat
22
-------
TABLE 2
Fourth Street Site
Exposure and Intake Assumptions for
Dermal Contact and Ingestion of Soil/Sludge and Surface Water
Current Use Scenario
Assumption
Duration of Exposure (years)
Dermal Soil Deposition (mg/cm3)
Skin Exposed to Soil (cm3)
Water Ingestion (I/day)
Dermal Exposure to Water (hr/day)
Skin Exposed to Water (cm3)
x vt> -'-' "',\ "> "<^7 ^ '^On^jSite ! at fourth 'Street
Dermal Exposure to Soil (day/year)
Soil Ingestion (mg/day)
/itl?^ "' ltr?i1>^pn;-s^e^'A't\'Fbur1^t?Sttee$
Dermal Exposure to Soil (day/year)
Dermal Exposure to Water (day/year)
Soil Ingestion (mg/day)
W^^^f\::>^^'^\ ' 4* s?;v:bff~ici
•Transient
Dermal Exposure to Soil (day/year)
Dermal Exposure to Hot Spot
(day/year)
Dermal Exposure to Water (day/year)
Soil Ingestion (mg/day)
For All Areas:
•Soil Dermal Absorption Factors:
Semivolatile Organics
Volatile Organics
Metals
•Gut Absorption Factors:
Metals , Semivolatiles
Volatile Organics
Age Groups by Years
7-11
5
1.4
4676
0.1
4
3392
Facility*
0
0
0
0
0
•etSTSS??
117
12
39
50
1.3%
5%
1%
50%
100%
12-17
6
1.4
6255
0.1
4
4905
-;-NPipeya
0
0
39
12
50
117
12
39
50
1.3%
5%
1%
50%
100%
Adult
10
1.4
4300
0.1
4
5190
ird!^, >J
0
0
I^?^'\;l
52
12
50
117
12
39
50
1.3%
5%
1%
50%
100%
Worker
10
1.4
4300
0.1
4
5190
*K£ •-. -
250
25
ij^jj^*'-%
0
0
0
1.3%
5%
1%
50%
100%
Sources: Skin surface areas exposed are from Anderson et al., (1984);
; other parameter values were derived as described in the text.
23
-------
TABLE i 3
Fourth Street Site
Exposure and Intake Assumptions for Inhalation
Current and Future Use Scenarios
Age group
% ' * .• % ** s* ^ f
7-11
12-17
Adult
^ v '-^ v- ^ -'\-y''' ^
7-11
12-17
Exposure
Duration
(Years)
; ; ;T"^^'
5
6
10
;,V'*>XV,1.,
5
6
Exposure
Frequency
(Days/yr)
-TransietvfcV ' I'
117
117
117
Pobl/Sch6o!l' -'"„
250
250 *
Respiratory
Volume
(m3/day)
'£ *;'^£::t^-'
4.6
4.6
4.6
:^j'iiV"'y' %'-'->
14
.14
Body
Weight
(kg)
'&-/' :y* -
27
48
70
«*X44?i?v^^^>?^v:'
18-70
30
365
27.4
70
^•f/'rv /^;^;/r:^^^^r^'^w6rIter^''^^ M^^V'^P^rV^
Industrial
Construction
Industrial-Future
;'f . ; ^ t ' "V
12-17
Adult
25
1
25
*, "<• ."-"r^
6
10
150
250
250
Trespasser-' ' ~ ;
39
52
6
20
20
-^ fs;r. <,-;;/ \s,
4.6
4.6
70
70
70
?>^>''%V'/'
48
70
Sources: USEPA 1991, USEPA 1989b, Anderson 1984
24
-------
areas to volatilized contaminants and/or to particulates
carrying contaminants;
Oral/dermal exposure of off-site construction workers to
the contaminants present in the areas of concern (hot
spot) in the Parcel H and eastern drainage areas;
Oral/dermal exposure of off-site construction workers to
the contaminants present in the soil/sediment surrounding
the site, in the Parcel H and in the eastern drainage
areas;
Direct exposure of off-site construction workers to
contaminants present in the surface water of the Parcel H
area impoundments through accidental exposure;
Inhalation exposure of off-site construction workers to
volatilized contaminants or to particulates carrying
contaminants;
Oral/dermal exposure of off-site industrial workers to
the contaminants present in the soil/sediment surrounding
the site, in the Parcel H and in the eastern drainage
areas;
Direct exposure of off-site industrial workers to
contaminants present in the surface water of the Parcel H
area impoundments through accidental exposure;
Inhalation exposure of off-site industrial workers to
volatilized contaminants or to particulates carrying
contaminants;
Oral/dermal exposure of transients to the contaminants
present in the areas of concern (hot spot) in the Parcel
H and eastern drainage areas;
Oral/dermal exposure of transients to the contaminants
present in the soil/sediment surrounding the site, in the
Parcel H and in the eastern drainage areas;
Direct exposure of transients to the contaminants present
in the surface water of the Parcel H area impoundments
through accidental exposure;
Inhalation exposure of the transients to volatilized
contaminants or to particulates carrying contaminants
while in the vicinity of the Fourth Street site or in the
Parcel H and in the eastern drainage areas;
Inhalation exposure of the children to volatilized
contaminants or to particulates carrying contaminants in
the ambient air while in the vicinity of the pool and the
25
-------
high school.
Table 3 lists the exposure and intake assumptions for inhalation,
for both the current and future use scenarios. Table 4 lists the
exposure and intake assumptions for dermal contact and ingestion of
surface soil/sludge and surface water, for the future use scenario.
c) Exposure Scenarios
There were four major sets of exposure pathways utilized for this
risk assessment of current use. They are:
• Pipeyard workers exposure to the on-site contaminants;
• Trespassers exposure to the on-site contaminants in the
Tar Mat area;
• Transients and children exposure to transported
contaminants which includes the Parcel H area; and
• Residents and children to air borne contaminants.
Therefore, the current use scenario includes on-site workers,
transients both on-site and in the immediate vicinity of the site,
and off-site residents. Since the site is only used periodically,
exposure assumptions are based on actual use.
There were five major sets of exposure pathways utilized for this
risk assessment of future use. They are:
• Pipeyard workers with continued operations in the
pipeyard area;
• Transients and children exposure to transported
contaminants;
• . Residents and children to air borne contaminants;.
• Construction workers engaged in building new facilities
on the Parcel H and Tar Mat areas; and
• Industrial workers employed at these new facilities.
The future use scenario assumes more frequent exposure to on-site
workers based on increased useage of the site. Standard default
assumptions were utilized. In addition, industrial redevelopment
of the Main site area, eastern drainage and Parcel H areas is
assumed, based on land use trends (previous section). Off-site
workers were considered under the future use scenario. The
residential exposure assumptions are the same under the future use
scenario as under the current use scenario. These assumptions were
identical since the residents could potentially be impacted via the
26 '""'.-
-------
TABLE
Fourth Street Site
Exposure and Intake Assumptions for Dermal Contact
and Ingestion of Surface Soil/Sludge and Surface Water
Future Use Scenario
Age Groups by Years
Duration of Exposure (years)
Dermal Soil Deposition (mg/cm2)
Skin Exposed to Soil (cm2)
Soil Ingestion (mg/day)
Skin Exposed to Water (cm2)
Water Ingestion (I/day)
Dermal Exposure to Water (hr/day)
7-11
5
1.4
4676
50
3392
0.1
4
, t : * ' ', x -,-''•-" -, on— Site at Fourth Street *
Dermal Exposure to Soil (day /year)
Soil Ingestion (mg/day)
0
0
- *t^s~ % ' c / - "" * -' * 1~ v,' OB-sitel at - Fourth* . Street: .
Dermal Exposure to Soil (day/year)
Dermal Exposure to Water (day/year)
0
0
12-17 Adult I
6
1.4
6255
50
4905
0.1
4
Facility
0
0
.'Faci^Lty
0
0
<.A&** '" '&' '" '"" " '* ' ''-'" '' * % ''""''" ' - ' ' ; " ' Off-Site r *>'* A '' --'
•Transient
Dermal Exposure to Soil (day /year)
Dermal Exposure to Hot Spot
(day /year)
Dermal Exposure to Water (day/year)
Soil Ingestion (mg/day)
For All Areas:
•Soil Dermal Absorption Factors
Semivolatile Organics
Volatile Organics
Metals
•Gut Absorption Factors
Metals, Semi volat lies
Volatile Organics
Sources: Skin surface areas exposed
117
12
39
50
1.3%
5%
1%
50%
100%
are
117
12
39
50
1.3%
5%
1%
50%
100%
10
1.4
4300
50
5190
0.1
4
— Pipeya
0
0
--^tarfci
0
0
X ^ *• '•• '"^\v i
•> x v ff'f
117
12
39
50
1.3%
5%
1%
50%
100%
from Anderson et
. Worker C. Worker
25
1.4
4300
50
5190
0.1
4
trd''"^
250
25
stf£ft^
250
12
'/^f*<
250
0
12
50
1.3%
5%
1%
50%
100%
aJ. ,
1
1.4
4300
50
5190
0.1
4
";^;~'^ -
0
0
.\V-'^|'H^Vv<
250
12
*'>'V£%'*'^".
250
12
12
50
1.3%
5%
1%
50%
100%
(1984); other
parameter values were derived as described in the text.
27
-------
air pathway, which will remains the same in the absence of any
remedial action.
Toxicity Assessment
The objective of the toxicity assessment is to weigh available
evidence regarding the potential for particular contaminants to
cause adverse effects in exposed individuals. Also, the toxicity
assessment provides, where possible, an estimate of the
relationship between the extent of exposure to a contaminant and
the increased likelihood and or severity of adverse effects. The
types of toxicity information considered in this assessment
include the reference dose (RfD) used to evaluate noncarcinogenic
effects and the slope factor to evaluate carcinogenic potential.
RfDs have been developed by EPA for indicating the potential for
adverse health effects from exposure to contaminants of concern
exhibiting noncarcinogenic effects. RfDs, which are expressed in
units of mg/kg-day, are estimates of acceptable lifetime daily
exposure levels for humans, including sensitive individuals.
Estimated intakes of contaminants of concern from environmental
media (e.g., the amount of a contaminated drinking water) can be
compared to the RfD. RfDs are derived from human epidemiological
studies or animal studies to which uncertainty factors have been
applied (e.g., to account for the use of animal data to predict
effects on humans and to protect sensitive subpopulations) to
ensure that it is unlikely to underestimate the potential for
adverse noncarcinogenic effects to occur. The purpose of the RfD
is to provide a benchmark against which the sum of the other doses
(i.e. those projected from human exposure to various environmental
conditions) might be compared. Doses that are significantly higher
than the RfD may indicate that an inadequate margin of safety could
exist for exposure to that substance and that an adverse health
effect could occur.
No RfD or slope factors are available for the dermal route of
exposure. In some cases, however, noncarcinogenic or carcinogenic
risks associated with dermal exposure can be evaluated using an
oral RfD or an oral slope factor. Exposures via the dermal route
generally are calculated and expressed as absorbed doses. These
absorbed doses are compared to an oral toxicity value that is also
expressed as an absorbed dose. Toxicity information used in the
toxicity assessment for the Site was obtained from the Integrated
Risk Information System (IRIS). If values were not available from
IRIS, the Health Effects Assessment Summary Tables (HEAST) were
consulted.
For chemicals that exhibit noncarcinogenic health effects,
authorities consider organisms to have repair and detoxification
capabilities that must be exceeded by some critical concentration
(threshold) before the health is adversely affected. For example,
an organ can have a large number of cells performing the same or
similar functions. To lose organ function, a significant number of
28 I
-------
those cells must be depleted or impacted. This threshold view
holds that exposure to some amount of a contaminant is tolerated
without an appreciable risk of adverse effects.
Health criteria for chemicals exhibiting noncarcinogenic effects
for use in risk assessment are generally developed using EPA's RfDs
developed by the Reference Dose/Reference Concentration ("RfD/RfC")
Work Group and included in the IRIS.
For chemicals that exhibit carcinogenic effects, most authorities
recognize that one or more molecular events can evoke changes in a
single cell or a small number of cells that can lead to tumor
formation. This is the non-threshold theory of carcinogenesis
which purports that any level of exposure to a carcinogen can
result in some finite possibility of generating the disease.
EPA's Carcinogenic Risk Assessment Verification Endeavor (CRAVE)
has developed slope factors (i.e., dose-response values) for
estimating excess lifetime cancer risks associated with various
levels of lifetime exposure to potential human carcinogens. The
carcinogenic slope factors can be used to estimate the lifetime
excess cancer risk associated with exposure to a potential
carcinogen. Risks estimated using slope factors are considered
unlikely to underestimate actual risks, but they may overestimate
actual risks. Excess lifetime cancer risks are generally
expressed in scientific notation and are probabilities. An excess
lifetime cancer risk of 1 x 10"6 (one in one million), for example,
represents the probability that one additional individual in a
population of one million will develop cancer as a result of
exposure to a carcinogenic chemical over a 70-year lifetime under
specific exposure conditions.
Slope factors (SFs) have been developed for estimating excess
lifetime cancer risks associated with exposure to potentially
carcinogenic contaminants of concern. SFs, which are expressed in
units of (mg/kg-day)'1 , are multiplied by the estimated intake of
a potential carcinogen, in mg/kg-day, to provide an upper-bound
estimate of the excess lifetime cancer risk associated with
exposure at that intake level. The term "upper bound" reflects the
conservative estimate of the risks calculated from the SF. Use of
this approach makes underestimation of the actual cancer risk
highly unlikely. Slope factors are derived from the results of
human epidemiological studies or chronic animal bioassays to which
animal-to-human extrapolation and uncertainty factors have been
applied( e.g., to account for the use of animal data to predict
effects on humans).
There are varying degrees of confidence in the weight of evidence
for carcinogenicity of a given chemical. The EPA system involves
characterizing the overall weight of evidence for a chemical's
carcinogenicity based on the availability of animal, human, and
other supportive data. The weight - of- evidence classification is
an attempt to determine the likelihood that the agent is a human
29
-------
carcinogen, and thus, qualitatively affects the estimation of
potential health risks. Three major factors are considered in
characterizing the overall weight of evidence for carcinogenicity:
<1) the quality of evidence from human studies; (2) the quality of
evidence from animal studies, which are combined into a
characterization of the overall weight of evidence for human
carcinogenicity; and (3) other supportive information which is
assessed to determine whether the overall weight of evidence
should be modified. EPA uses the weight of evidence classification
system to categorize carcinogenicity of contamination as one of the
following five groups:
Group A - Human Carcinogen: This category indicates that there
is sufficient evidence from epidemiological studies to support
a causal association between an agent and cancer.
Group B - Probable Human Carcinogen: This category generally
indicates that there is at least limited evidence from
epidemiological studies of carcinogenicity to humans (Group
Bl) or that, in the absence of adequate data on humans, there
is sufficient evidence of carcinogenicity in animals (Group
B2)
Group C - Possible Human Carcinogen : This category indicates
that there is limited evidence of carcinogenicity in animals
in the absence of data on humans.
Group D - Not Classified: This category indicates that the
evidence for carcinogenicity in animals is inadequate.
Group E - No Evidence of Carcinogenicity to Humans; This
category indicates that there is no evidence for
carcinogenicity in at least two adequate animal tests in
different species, or in both epidemiological and animal
studies.
Several of the initial chemicals of concern have been classified as
potential carcinogens by EPA. Each of these also has been assigned
a carcinogenicity weight -of-evidence category. These chemicals are
presented in Table 5 with the respective Referenced Doses and
Potency Factors.
Human Health Risk Characterization
For all exposure scenarios, the air pathway contributed the
greatest carcinogenic risk and HI. Direct contact to soil/sediment
and sludge also contributed to the carcinogenic risk. Direct
contact to the surface water did not contribute significantly to
the risk. However, the HI do not include the toxic effects of lead
and the potential synergistic effects. These estimates suggest
that the receptors are at hazard from exposure to these chemicals
for potential carcinogenic and toxic effects. The contaminants of
concern which actually drove the carcinogenic risk and/or HI will
30
-------
TABLE 5
Fourth Street site
Reference Doses and Potency Factors for Contaminants of Concern
Contaminant
Arsenic
Berylliun
Cadmiun
Benzene
Tetraeh loroethylene
Trichloroethylene
Hethytene Chloride
Phthatates
PCBs
Styrene
Benzo(a)pyrene
Benzo(a)anthracene
Benzo(b) f luoranthene
Naphthalene4
Heptaehlor
CJilordane
Antimony
Barium
Copper
Lead
Nickel
Thallium
Vanediua
Zinc
Ketones5
A Iky I Benzenes
PhenoU2,4-Di«ethyl)
1,1.1-Triehlorethane
RfD(O)
ng/kg-day
1E-3
5E-3
1E-3
.2
1E-2
.
6E-2
2E-2
.
2E-1
4E-3
4E-3
4E-3
4E-3
5E-4
6E-5
4E-4
5E-2
2E-25
NO
2E-2
7E-5
7E-3
2E-1
5E-2
2E+0
96-2
2E-2
9E-2
RfO(I)
mg/kg-day
ND1
.
NO
.
ND
*
.
ND
.
ND
.
.
.
.
ND
NO
ND
1E-4
ND
ND
ND
.
-
ND
9E-2
2E-1
4E-2
ND
3E-1
Carcinogen
Class
A
82
B1
A
B2
B2
82
B2
82
82
82
82
82
-
82
82
.
.
.
.
.
-
.
.
-
.
-
.
-
Pf<0) ,
(mg/kg-day)
1.8E+0
8.4E+0
NO
2.9E-2
5.1E-2
1.1E-2
.
1.4E-2
7.7E+0
3.0E-2
1.1E+13
1.1E+03
1.1E+03
-
5E*0
1E+0
-
.
.
-
-
-
•
.
.
.
-
.
-
Pf(I> ,
-------
be discussed for each pathway:
a) Current Risk Characterization
The estimated overall risks of carcinogenic effects from exposure
to the on-site contaminants for the workers (1.2x10"*) and
trespassers (2.7xlO"s) are greater than the target risk of IxlCT6.
The COCs which drove the risk are Chlorinated Hydrocarbons for the
inhalation pathway and PAHs for the soil contact pathway. The
estimated overall His of non-carcinogenic effects from exposure to
the on-site contaminants for the workers (0.89) and trespassers
(0.23) are less than the target HI of one (1.0).
The estimated overall risks of carcinogenic effects from exposure
to the off-site contaminants for the transient adults (4.8xlO~5),
the 7-11 age group (6.5xlO's) and the 12-17 age group (4.9xlO's)
aregreater than the target risk of IxlO"6. The COCs which drove the
risk are Chlorinated Hydrocarbons for the inhalation pathway and
PAHs for the soil contact pathway. The estimated overall His of
non-carcinogenic effects from exposure to the off-site contaminants
for the adults (0.27), 7-11 age group (0.70), and 11-17 age group
(0.42) are less than the target HI of one (1.0).
The estimated overall risks of carcinogenic effects from exposure
to the off-site contaminants in the air for the nearby residents
(2.lxlO'3) and children at the pool and high school (3.1xlO~* for the
7-11 age group and 2.1X10"4 for the 11-17 age group) are greater
than the target risk of 1x10"*. The COCs which drove the inhalation
risk are Chlorinated Hydrocarbons, Heptachlor and Chlordane. The
estimated overall HI of non-carcinogenic effects from exposure to
the off-site contaminants for the resident (3.30) and for children
at the pool and high school (3.00 for the 7-11 age group and 1.7
for the 11-17 age group) are greater than the target HI of one
(1.0). The COCs which contributed to the HI are BTEXs, (Benzene,
Toluene, Ethylbenzene, Xylenes) and Trichloroethane. Particulate
air sampling results for lead were high (17.9 ug/m3) ,onsite.
However, upwind locations were higher (32 ug/m3). Therefore, the
risk calculated for children at the pool and the high school is not
attributable to the site, since this location was the upwind
monitoring station.
b) Future Risk Characterization
The estimated overall risk of carcinogenic effects from exposure to
the on-site contaminants for the future workers (S.SxlO"4) is
greater than the target risk of ixlO"6. The COCs which drove the
risk are Chlorinated Hydrocarbons, Benzene, Heptachlor and
Chlordane for the inhalation pathway; and PAHs for the soil contact
pathway. The estimated overall HI of non-carcinogenic effects from
exposure to the on-site contaminants for the workers (2.60) is
greater than the target HI of one (1.0). The COCs which contributed
significantly to the HI are Alkyl Benzene and Ketones for
32
-------
inhalation; and Chlorinated Hydrocarbons and PAHs for the soil
contact pathway.
The estimated overall risks of carcinogenic effects for off-site
transient adults and children on Parcel H and off-site residents
and school children are the same as the current exposure scenario.
This is assuming no redevelopment of the off-site areas occurs.
If redevelopment occurs the most reasonable land use would be
industrial, therefore construction workers and full time industrial
workers would be exposed. The estimated overall risk of
carcinogenic effects from exposure to the off-site contaminants for
the construction workers (3.7xlO's) and for the future industrial
workers (9.3x10"*) is greater than the target risk of 1x10"*. The
COCs which drove the risk are Chlorinated Hydrocarbons and
Heptachlor for the inhalation pathway; and PAHs and PCBs for the
soil contact pathway. The estimated overall HI of non-carcinogenic
effects from exposure to the off-site contaminants for both types
of worker scenarios (1.8) is greater than the target HI of one
(1.0). The COCs which contributed to the HI are Alkyl Benzene,
Ketones, and Chlorinated Hydrocarbons for inhalation.
Qualitative Assessments; Lead was found in high concentrations
throughout the FSR site (up to 5,000 mg/kg in some locations. It
was also found at elevated concentrations (up to 1000 mg/kg) in
off-site soil/sediment and waste materials. Since there are no
currently-accepted toxicity criteria, lead was not quantitatively
evaluated; therfore, a qualitative evaluation was necessary.
Lead and its compounds have a wide variety of industrial uses; as
such, lead contamination is widespread in the environment. The
major sources of lead exposure in the environment include releases
from vehicular exhaust (currently being reduced by EPA fuel lead
content regulations); discharges from primary and secondary
smelting operations; leaching from lead pipes and solder into
drinking water supplies; and, ingestion of lead-contaminated paint
chips, house dust, and soil by children.
The toxic effects of lead depend on the specific compound to which
humans are exposed. Generally, organic lead compounds, such as the
gasoline additive tetraethyl lead, are somewhat more toxic than
soluble lead salts, particularly with regard to the central nervous
system. This is apparently due to their higher affinity for
tissues with high lipid content. Less soluble lead compounds may
also be less toxic than soluble salts, on the basis of administered
dose, because of their less efficient absorption into the
bloodstream from the gastrointestinal or respiratory tract.
Lead exposure produces a wide range of adverse effects in humans,
over a wide range of exposures. Lead is known to effect the
hematopoietic system, the kidneys, the peripheral and central
nervous systems, and the reproductive system. Lead compounds have
been found to be mutagenic in several test systems, and have been
33
-------
found to cause cancer in several animal bioassays.
Children are generally more sensitive to lead exposures than
adults. The principal concern with regard to lead exposures in
young children (under age 6) is the occurrence of impaired
neurological development, which may be associated with a broad
spectrum of neurobehavioral disorders. Originally, it was thought
that such effects occurred at lead exposures associated with a
blood level greater than 35 ug/dl. More recent studies have found
that such effects may occur at much lower blood lead levels,
perhaps as low as 10 ug/dl. EPA currently evaluates lead exposures
in children in reference to the latter benchmark blood-lead level
(10 ug/dl).
EPA has classified lead as a Class B2 carcinogen. A number of lead
compounds have been found to induce elevated cancer incidence in
rats and mice. However, the evidence for the association between
lead exposure and elevated cancer rates in epidemiologic studies of
human populations experiencing high lead exposures is equivocal.
EPA has therefore not derived a cancer potency factor for lead
compounds. The EPA has determined that an RfD would not be
appropriate to protect children from adverse developmental impacts
of lead exposure, due to the complex relationship between lead
exposures by various routes, blood-lead levels, and the occurrence
of adverse effects. Instead, EPA had developed a biokinetic model
for assessing the impacts of multi-route lead exposures on
children's blood-lead levels.
EPA recommends that this model be used for age groups 0 to 6 years
to evaluate the health significance of lead exposures using a
target blood lead level of 10 ug/dl as an indicator of potential
adverse effects. At the FSR site this model was considered, but
adapting the model for industrial land use and adult exposures
produced inappropriate or erroneous information. Alternatively,
EPA has provided OSWER (Office of Solid Waste and Emergency
Response) Directive #9355.4-02, which establishes that an excess of
lead in soil of 500 to 1000 ppm is responsible for blood level
increases in children above background levels. The concentrations
at the FSR site are of such magnitude that exposure to these
materials is likely to be a cause for concern.
Additionally, the industrial setting of the FSR site also presents
a problem in evaluating the air pathway quantitatively. Although
the air pathway contributed the greatest risk and hazard index for
organics detected, a trend is not apparent to suggest that the site
contributes to the ambient air contaminant levels of the
surrounding area. This is due to high gasoline constituent levels
measured upwind of both the FSR and DER sites; probably due to the
areas surrounding both sites being highly industrialized.
Similarly, particulate air sampling results for lead were high
(17.9 ug/m3) onsite. However, upwind locations were higher (32
ug/m3). Therefore, the risk calculated for children at the pool
and high school may not be attributable to the site, since this
34
-------
location was the upwind monitoring station.
Central Tendencies
Based on a February 26, 1992, memorandum from Deputy Administrator
F. Henry Habicht, EPA is required to evaluate both "reasonable
maximum exposure" (RME) and "central tendency" in the risk
assessment at Superfund sites. The exposure assumptions associated
with the RME have been used to estimate the baseline risks and
ultimately the remedial action goals at sites. The "central
tendency" scenario represents the risk from more of an "average"
exposure, compared to a "reasonable maximum" exposure.
A comparison of the differences in the risk assumptions between the
RME and central tendency is shown in Table 6. For the FSR site the
central tendency risks would decrease from 3.0xlO'3 to l.OxlO"3 for
the current risk and from l.OxlO"2 to S.OxlO"3 for future risk to
on-site workers.
Uncertainties Associated with the Human Health Risk Calculations
Within the Superfund process, baseline quantitative risk
assessments are performed in order to assess the potential human
health impacts of a given site under currently existing conditions.
They are performed in order to provide risk managers with a
numerical representation of the severity of contamination present
at the site, as well as to provide an indication of the potential
for adverse public health effects. There are many inherent and
imposed uncertainties in the risk assessment methodologies.
This section addresses potential sources of uncertainty in the risk
estimates, possible impacts of the various sources of uncertainty
and potential bias in the risk estimates. This discussion provides
a context in which the significance and limitations of the various
results can be better understood to evaluate the overall potential
health impacts of the Fourth Street site.
Significant uncertainties are associated with estimates of
exposures and human health risks presented in the risk assessment.
The uncertainties in these results are unavoidable in that they all
depend, to a greater or lesser extent, upon many technical
judgements and, to a lesser extent, upon imperfect mathematical
models of physical, chemical, and biological processes.
Several techniques have been developed to address these
uncertainties. These techniques include the following:
• use of multiple exposure and risk scenarios to illustrate the
range of variability in risk estimates associated with
specific analytical methods and assumptions;
• qualitative discussion of the levels of uncertainty associated
with specific models and assumptions, and how they contribute
35
-------
TABLE 6
Average or
Central Tendency
Reasonable
Maximum Exposure
Contact Rates fCR)
Water Ingestion Rates
Children (1-6 yrs)
Adults
Workers
Soil Ingestion Rates
Children (1-6 yrs)
Adults
Workers
Fish Ingestion Rates
Adults
Air Inhalation Rates
Children (1-6 yrs)
Adults
0.7 L/day
1.4 L/day
0.7
200 nvg/day
100 mg/day
50 jng/day
6.5 g/day
5 cu. m/day
20 cu.m/day
Dermal Exposure
Adherence factor (AF) 0.2 mg/cm2
Absorption factor (ABS) Chemical-specific
Total Surface Area (SA)
Children 7,200 cm2/event'
Adults 20,000 cm2/event
Body Weights (BVH
Children (1-6 yrs) 16 kg
Adult 70 kg
Workers 70 kg
l L/day
2 L/day
1 L/day
200 mg/day
100 mg/day
50 mg/day
54 g/day
5 cu.m/day (50%)
20 cu.m/day (50%)
1 mg/cm2
Chemical-specific
7,200 cm2/event
20,000 cm2/event
16 kg (50%)
70 kg (50%)
70 kg (50%)
36
-------
Average or
Central Tendency
Exposure Duration (ED)
Residential 9 years
Industrial 9 years
350 days/year
250 days/year
Exposure Frequency fEF)
Residential
Industrial
Averaqing Time (AT)
Carcinogenic effects 70 years
Noncarcinogenic effects ED
Reasonable
Maximum Exposure
30 years
25 years
350 days/year
250 days/year
70 years
ED
C. References For Central Tendency Exposure Parameters
Concentration Term (C)
Site-specific value
Contact Rates fCR)
Water Ingestion Rates
Children (1-6 yrs)
Adults
Workers
Soil Ingestion Rates
Children (1-6 yrs)
Adults
Workers
Fish Ingestion Rates
Adults
Central Tendency
95% UCL
Basis/Reference
US EPA, 1992a
0.7 L/day
1.4 L/day
0.7
200 mg/day
100 mg/day
50 mg/day
6.5 g/day
US EPA, 1989a
US EPA, 1989b
50% Adults
Ingestion Rate
US EPA, 1989C
US EPA, 1989C
US EPA, 1991
US EPA, 1989b
37
-------
Air Inhalation Rates
Children (1-6 yrs)
Adults
Central Tendency
5 cu. in/day
20 cu.in/day
Dermal Exposure
Adherence factor (AF) 0.2 mg/cm2
Absorption factor (ABS) Chemical-specific
Total Surface Area (SA) '
Children (1-6 yrs) 7,200 cm2/event
Adults
Body Weights (BW)
Children (1-6 yrs)
Adult
Workers
20,000 cm2/event
16 kg
70 kg
.70 kg
Exposure Duration fED)
Residential 9 years
Industrial 9 years
350 days/year
250 days/year
Exposure Frequency (EF)
Residential
Industrial
Averaging Time (AT)
Carcinogenic effects 70 years
Noncarcinogenic effects ED
Basis/Reference
US EPA, 1989a
US EPA, 1989a;
US EPA, 1989b
US EPA, 1992b
US EPA, 1989a;
US EPA, 1989b
US EPA, 1992b
US EPA, 1989b
US EPA, 1989b;
US EPA, 1991
US EPA, 1991
US EPA, 1989b
= to residential
US EPA, 1991
US EPA, 1991
US EPA, 1989b
US EPA, 1989b
38
-------
D. Reasonable Maximum Exposure Parameters
Reasonable Maximum
Concentration Term fC)
Site-specific value 95% UCL
Contact Rates fCRl
Water Ingestion Rates
children (1-6 yrs)
Adults
Workers
Soil Ingestion Rates
Children (1-6 yrs)
Adults
Workers
Fish Xngestion Rates
Adults
Air Inhalation Rates
Children (1-6 yrs)
Adults
Adults
1 L/day
2 L/day
1 L/day
200 mg/day
100 mg/day
50 mg/day
54 g/day
5 cu. m/day
20 cu.m/day
30 cu.m/day
Basis/Reference
US EPA, 19923
US EPA, 1939a
US EPA, 1989b;
US EPA, 1991
US EPA, 1991
Average value,
US EPA, 1989c
Average value,
US EPA, 1989c
Average value,
US EPA, 1991
US EPA, 1991
US EPA, 1989a
Average value,
US EPA, 1989a;
US EPA, 1989b
Upper bound #,
US EPA, I989a;
US EPA, 1989b
39
-------
Reasonable Maximum
Dermal Exposure
Adherence factor (AF) 1 mg/cm2
Absorption factor (ABS) Chemical-specific
Total Surface Area (SA)
Children (1-6 yrs) 7,200 cm2/event
Adults
Body Weights fBVH
Children (1-6 yrs)
Adult
Workers
20,000 cm2/event
16 kg
70 kg
70 kg
Exposure Duration (ED)
Residential 30 years
Industrial
25 years
Exposure Frequency fEF)
Residential 350 days/year
Industrial
250 days/year
Averaging Time (ATA
Carcinogenic effects 70 years
Noncarcinogenic effects ED
Basis/Reference
US EPA, 1992b
Average value,
US EPA, 1989a;
US EPA, 1989b
Average value,
US EPA, 1992b
Average value,
US EPA, 1989b
Average value,
US EPA, 1989b;
US EPA, 1991
Average value,
US EPA, 1991
US EPA, 1989b;
US EPA 1991
US EPA 1991
Average value,
US EPA, 1991
Average value,
US EPA, 1991
US EPA, 1989b
US EPA, 1989b
40
-------
E. References
US EPA. 1989a. Exposure Factors Handbook. EPA/600/8-89/043.
US EPA. 1989b. Risk Assessment Guidance for Superfund, Volume I,
Human Health Evaluation Manual (Part A). EPA/540/1-89/002.
US EPA. I989c. Interim Final Guidance for Soil Ingestion Rates.
OSWER Directive 9850.4.
US EPA. 1991. Risk Assessment Guidance for Super fund, Volume I,
Human Health Evaluation Manual, Supplemental Guidance, Standard
Default Exposure Factors. OSWER Directive 9285.6-03.
US EPA. 1992a. Supplemental Guidance to RAGS: Calculating the
Concentration Term. Publication 9285.7-081.
US EPA. 1992b. Dermal Exposure Assessment: Principles and
Applications. EPA/600/8-91/011B.
41
-------
to uncertainties in the overall assessment; and,
• use of probabilistic risk models or formalized sensitivity
analyses which quantify uncertainties in each step of the risk
assessment.
The approach taken in this assessment has been to apply a
combination of the first two methods, multiple exposure and risk
scenarios and qualitative discussions of uncertainty in specific
aspects of the models, to characterize the level of uncertainty
associated with risk estimates. One probabilistic model was
performed to examine the assumptions used in this risk assessment
and to illustrate the uncertainty. Multiple exposure scenarios
have been developed which illustrate the potential range of
exposures that can occur at the site under present and possible
future use. Exposures have been assessed with regard to
individuals in multiple age categories as a means of determining
how physiological and behavioral characteristics of these
populations might affect exposure and dose levels.
The overall strategy employed in assessing exposures has been to
define methods and assumptions in such a way as to develop
reasonable maximum estimates for all of the major assumptions used
in the risk modeling. That is, where there is a range of models to
choose from, or a range of parameter values to be used in these
models, the specific models used and parameters chosen are those
which are at the upper-bound of realism and reasonableness, based
upon professional judgement and information available in the
literature. The overall impact of this technique on the assessment
of risks is to generate results which, if assessed in a
quantitative probabilistic way, would lie at the upper end of the
expected probability distribution of risk. It is unlikely that
actual risks calculated for any pathway will exceed those
predicted. For example, if it is assumed that a given risk
estimate is derived from three independent models of contaminant
concentrations, contaminant transport, and dose/risk
characterization, and that the parameter values chosen for use in
each model are at or above the 90-percent upper-bound confidence
interval of their actual expected value, then statistically, the
probability that the resulting risk estimate will exceed
(overestimate) the actual risk will be 99.9 percent. That is,
there would be only a 0.1 percent (one in one thousand) probability
that actual risks will exceed calculated risks.
Ecological Risks
The baseline ecological risk assessment, performed by the EPA,
provides a qualitative evaluation of the environmental risks at the
Double Eagle site. The site ecology was evaluated to determine if
the contamination from the site was causing any significant adverse
ecological impact.
The ecological risk assessment is summarized as follows:
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a) Receptor Characterization and Endpoints
Receptor Characterization; Potential environmental receptors
include fish populations in the North Canadian River, woody or
herbaceous (non-woody) plants, birds or mammals feeding on this
vegetation, and animals incidentally using the open water areas
(migratory waterfowl and mammals).
Site visits have resulted in observation of a killdeer with its
nest of eggs on the Fourth Street site. Small tadpoles have been
noted in the larger impoundment on site. Turtles and frogs have
been observed at the Double Eagle site. Rabbits are common in the
area of both sites and egrets and other migratory waterfowl have
been sited at the impoundents on parcel H.
A site survey during collection of samples for the toxicity
testing on Parcel H demonstrated that no minnows were available in
the impoundments that could be collected for bioaccumulation
studies, as originally planned. A black snake, believed to be a
King Snake, of about 6 feet in length was encountered at the Radio
Tower Area.
Impoundments on both sites appear on the National wetlands
Inventory Maps (NWI) (U.S. Dept. of Interior, Fish and Wildlife
Service, 1989). However, since these NWI maps were developed (the
mapping process began in 1991), site changes have likely occurred.
These maps are based on interpretation of aerial photographs and
not actual site surveys.
The Parcel H area incudes three different classification areas:
PUBFx, PUBHx, and Palustrine, Emergent, Semi-Permanently Flooded
Wetlands (PEMF).
Vegetation around open wate» areas at Fourth Street and Parcel H
appears to consist of grasses, likely to be prairie grass species
rather than wetlands species. The former operations area of Fourth
Street and the Eastern Drainage and Parcel H areas appear to have
grass and shrubby vegetation. They are generally open areas that
might not provide much shelter or food for permanent populations of
wildlife species other than small mammals as mentioned above.
Endpoints; Biological Integrity: An assessment endpoint is the
maintenance of biological integrity (i.e., the maintenance of the
structure and function of aquatic ecosystems). The measurement
endpoints for this assessment endpoint will be "toxicity1' as
demonstrated by aquatic toxicity tests. The objective of aquatic
toxicity tests is to estimate the "safe" or "no effect"
concentration which permits the normal propagation of fish and
other aquatic life (U.S. EPA 1988). Toxicity testing assessed the
toxicity of the oily wastes from the site on aquatic life.
43
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b) Toxicological-Response Assessment
Heavy metals, lead and chromium, present long-term threats and
could present a serious environmental effect. Due to the habitat,
impacts on the aquatic environment would be more serious than
effects on the terrestrial environment. Therefore, only aquatic
effects were studied.
Toxicity tests were conducted on water from the Parcel H
impoundments (Bio-Aquatic Testing, 1990), in which Ceriodaphnia
dubia survival and reproduction, Pimephales promelas larval
survival and growth, and bacterial luminescence (MicroTox tests)
were measured. Results of toxicity tests indicate that impoundment
water could have toxic effects on aquatic life. The maintenance of
biological integrity in these impoundments could be impaired by
site related contaminants.
c) Exposure Assessment
There is no current drainage connection between the sites and the
North Canadian River, although it should be noted that there was a
connection in the past. Potential impacts of the sites on fish
populations, especially game fish, are not currently an issue given
the assumption that the impoundments do not support a fish
population. However, other on-site environmental receptors could
be exposed to site related contaminants. These receptors might be
woody or herbaceous (non-woody) plants growing in locations of
relatively high contamination, birds or mammals feeding on this
vegetation, and any organisms (migratory waterfowl and mammals)
incidentally using the open water areas.
d) Risk Characterization
The EPA indicates that environmental receptors, in particular
migratory fowl, could be adversely affected by site related
contaminants. Toxicity tests indicate that the potential for toxic
effects "from the Parcel H impoundment water on aquatic life do
exist. The analytical results from surface water samples from the
Parcel H impoundments indicate that the chronic water quality
criteria for copper, and the chronic and acute water quality
criteria for lead were exceeded. Therefore, the maintenance of
biological integrity in these impoundments could be impaired by
site related contamination.
Actual or threatened releases of hazardous substances from this
site, if not addressed by implementing the response action selected
in this Record of Decision, may present an imminent and substantial
endangerment to public health, welfare, or the environment.
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Vn. REMEDIAL ACTION GOALS
Results of field investigations, laboratory test results, and
engineering analyses have identified the following contaminant
source areas on the FSR site with associated affected media:
Site Area Media
Tar mat area Sludge, debris and air
Pipe yard area Sludge and air
Impoundments Sediment, surface water and air
Exposed waste
(off-site) Sediment, surface water and air
Structures Tank stands, concrete foundations
and debris
Principal threat wastes are those source materials considered to be
highly toxic or highly mobile that generally cannot be reliably
controlled and that present a significant risk to human health or
the environment should exposure occur. The principal threats at
the FSR site are the acidic sludges and contaminated ponds. These
discrete waste areas present the most significant risk at the site,
due to the potential for exposure to lead through direct contact
and inhalation. The risk is also increased due to the concentrated
nature of the waste which presents a high potential for migration
of contaminants to surrounding areas and the underlying ground
water.
Low level threats are those source materials that generally can be
reliably managed with little likelihood of migration and that
present a low risk in the event of exposure. The low level threats
at the site are the contaminated soils and tar matrices, both on
and off-site. These areas are not as highly mobile as the acidic
sludges and the material in the ponds on-site and the concentration
of contaminants is more dilute which decreases the risk from
potential exposure.
The principal threat at the FSR site is posed by direct contact and
inhalation, and potential for migration of contaminants to the
ground water. The remedial objectives are to minimize potential
exposure by direct contact or inhalation, and to reduce the
potential for migration of contaminants into the surface waters and
ground waters.
During the RI/FS project for the FSR site, the issues related to
the ground waters beneath the site were acknowledged as complex in
comparison to those issues apparent for the source contamination.
Although shallow and deep wells were installed around the perimeter
of both the FSR and DER sites, the determination of vertical and
45
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lateral migration of contaminants will require further study. The
impact of the migration of contaminants in ground water and surface
water will be addressed in a future ROD, Operable Unit 2
(Groundwater Operable Unit - GOU). This ROD will address the
source of contamination at the FSR site, Operable Unit 1 (Source
Control Operable Unit - SCOU).
As discussed in the Risk Characterization section, the surface
water present at the FSR site does not pose a significant threat.
The PAHs, PCBs and lead found in pond sediments and sludges pose
the most significant threat (carcinogenic excess risks) due to
direct contact. The Chlorinated Hydrocarbons, Heptachlor,
Chlordane, BTEXs (Benzene, Toluene, Ethylbenzene, Xylene),
Trichloroethane, Alkyl Benzene and Ketones pose the most
significant threat (carcinogenic excess risks) due to inhalation.
Since the remedial action goal for the FSR site is to eliminate or
reduce risk to human health and the environment, target action
levels for soil, sediments, and sludges have been established. As
discussed in the Qualitative Assessment section, the OSWER guidance
was utilized for lead. A target action level of 500 ppm for lead
will be utilized, based on industrial laud use for the DER site.
For PCBs, a target action level of 25 ppm corresponds to the Toxic
Substances Control Act cleanup level for industrial land use.
However, the maximum concentration of PCBs detected at the DER site
is much less than this level and therefore already meets the
remedial objectives. For PAHs, a target level of 30 ppm Total
Benzo(a)Pyrene Equivalents has been set. This concentration
represents approximately a 10~* excess cancer risk and was selected
based on Regional guidance for setting remedial goals for PAHs.
By addressing the source of contamination at the DER site (soils,
sediments, and sludges), the risk associated with the air pathway
will be eliminated. However, short-term risks due to air emissions
during a remedial action will also be addressed by use of Region 6
Standard Operating Procedures (SOP) for air emissions, during
remedial- design. The SOP for air emissions is dated November,
1991.
Vin. DESCRIPTION OF ALTERNATIVES
A Feasibility Study was conducted to develop and evaluate remedial
alternatives for the FSR site. Remedial alternatives were assembled
from applicable remedial technology process options and were
initially evaluated for effectiveness, implementability, and cost
based on engineering judgement. The alternatives selected for
detailed analysis were evaluated and compared to the nine criteia
required by the NCP. As a part of the evaluation, the NCP requires
that a no-action alternative be considered at every site. The no-
action alternative serves as a point of comparison for the other
alternatives.
46
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The Remedial Action Goals set for the FSR site are the
concentration levels below which the media can be left in-place
without treatment. The descriptions and evaluations of remedial
action alternatives included in this ROD addresses surface
contamination, contamination associated with surface soil and the
material in the impoundments on the main site, soil and sludges on
Parcel "H". Ground water contamination will be investigated
separately in the GOU. Upon completion of this investigation, EPA
will propose a plan of action to address any potential problems
from ground water contamination identifed at the site.
The descriptions and evaluations of remedial action alternatives
are separated into seven alternatives addressing contaminated
sediments, surface soils, suface water, and sludges.
Remedial Action Alternatives
The remedial action alternatives for the SCOU are presented below
with a description of the common elements contained in each
alternative.
• Alternative 1: No Action
• Alternative 2: Limited Action
• Alternative 3: On-site Stabilization and Capping
• Alternative 4: On-site Stabilization and Disposal in an
On-site Landfill
• Alternative 5: On-site Stabilization and Disposal in an
Off-site Landfill
• Alternative 6: Excavation, On-site Incineration, and
On-site
Capping of Ash
• Alternative 7: Excavation, Off-site Incineration and
Disposal of Ash
Common Elements
All of the SCOU alternatives, with the exception of Alternative 1,
have the following common elements: site preparation; the
installation of office, storage, and security facilities; the
installation of surface water runoff control measures; installation
and maintenance of warning signs and fencing; placement of a notice
to the property deed warning of site hazards; restoration of the
site surface upon completion of the remedial action; and air
monitoring and dust control to minimize any potential short-term
adverse health effects during the remedial action.
All of the alternatives, with the exception of Alternative 1 and 2,
involve treating and/or containing soils, sediments and sludges
which have contaminant concentrations that exceed remedial goals.
These alternatives were developed to address the specific mixture
of wastes at the FSR site. The high concentration of lead at the
site precludes biological treatment as an alternative and increased
the need for air pollution controls and residuals treatment for
47
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incineration^ The low organics concentration in the sludges (below
health based cleanup levels) allowed stabilization to occur, as
shown in treatability studies conducted in the feasibilty study.
All costs and implementation times are estimates. The costs have
a degree of accuracy of +50% to -30% pursuant to the "Guidance for
Conducting Remedial Investigations and Feasibility Studies Under
CERCLA - Interim^Final" OSWER Directive 9955.3-01, October 1988.
A brief description of the seven alternatives evaluated to address
contaminated sludges, sediments, surface soils, and surface waters
follows:
Alternative 1: No Action
Alternative 1 is a "no action" alternative for contaminated
sludges, sediments, surface soils, and surface water. This
alternative does not provide a means for source control or the
monitoring of the environmental media to determine if contaminant
releases are occurring.
No action alternatives are normally evaluated to determine what the
threat would be, based on a risk assessment, to human health and
the environment if no further actions were taken. The risk
assessment performed assuming a no action alternative provides a
baseline for the comparison of other alternatives. The no action
alternative would not reduce or eliminate the threat posed by the
contaminants of concern presently on-site; therefore, the remedial
action objectives would not be met. Without enhanced source
control, contaminant releases into the air and groundwater could
occur, potentially endangering human health and the environment.
Although the no action alternative would not reduce the risk from
the site, the NCP requires that the no action alternative be
carried through to the detailed analysis of alternatives. The no
action alternative will therefore be carried through to provide a
baseline- of comparison to the alternatives utilizing remedial
action.
There are no costs associated with Alternative 1.
Alternative 2: Limited Action
Maior Components of the Limited Action Alternative: Components of
this alternative include: consolidation of approximately 1,200
cubic yards of contaminated waste material from Parcel H; netting
the ponds on-site to comply with Migratory Bird Act; construction
of security fencing and posting signs around the site; deed notices
to identify material remaining on-site; perpetual operation and
maintenance of the site; and five year reviews of the remedial
action.
48
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Access restrictions would be provided by the construction of a
fence with the addition of a sufficient number of warning signs
surrounding the site. This would restrict access to the site by
unauthorized persons and possibly wildlife inhabiting the
surrounding environment. A deed notice would be filed to notify
future land owners of the hazards associated with this site. Fifty
per cent of the volume of the waste from Parcel H (1,200 cubic
yards), which is above the remedial action goals discussed in
Section VII of this ROD, will be consolidated with the material on
the site. This operation will eliminate the risk from exposure to
the contaminants of concern and the need for fencing, deed
notification and perpetual maintenance for Parcel H. The excavated
off-site areas will be backfilled to grade with clean fill.
Perpetual maintenance to ensure the integrity of the nets and
fences onsite would be required.
General Components: The estimated time to implement this remedy is
12 months. The estimated cost associated with implementing
Alternative 2 are: Capital Costs: $150,000; Annual Operation and
Maintenance Costs: $10,000; Present Worth: $300,000.
Alternative 3: On-site Stabilization and Capping
Manor Components of the Remedial Alternative. The major features of
this alternative consists of the consolidation of off-site wastes
(as discussed in alternative 2), neutralization of the acidic
wastes and in-situ stabilization of 42,000 cubic yards of material
contaminated above the target levels discussed in Section VII of
this ROD, installation of a Subtitle C cap (approximately 2 acres)
over the treated waste, fencing, warning signs, deed notice,
perpetual maintenance and 5 year reviews. Perpetual maintenance is
required because the waste ^materials will remain on site as a
result of this remediation e'ffort.
Treatment Components: Alternative 3 utilizes an in-situ
stabilization/ solidification technology as a treatment process for
the waste material. Stabilization/solidification of the waste
materials utilizing commercially available materials such as
flyash, kiln dust or portland cement, will provide a neutralized
end product of sufficient structural strength to support a final
cover system.
Stabilization refers to the transformation of the waste into a form
where chemical reactions, or the potential for chemical reactions,
is eliminated over the long-term. Stabilization would place the
inorganic contaminants, like lead and other heavy metals, in a less
soluble form and therefore, reduce the mobility of the contaminant.
Solidification does not necessarily involve a chemical interaction
between the waste and the solidifying agents, but may mechanically
encapsulate the waste into a monolith. Contaminant migration is
restricted by decreasing the surface area exposed to leaching
and/or by isolating the wastes within an impervious capsule.
49
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Treatability studies conducted as part of the feasibility study
indicate that stabilization/ solidification is an effective
technology for the wastes at the FSR site. The results of these
studies are shown in Tables 7 and 8. These results indicate that
following treatment, none of the TCLP chemicals were detected above
their respective TCLP regulatory levels (40 CFR Part 261.24). The
optimum mixture yielding these results was 150% kiln dust and 10%
lime by weight. The low levels of organic COCs and PCBs allows the
stabilization/ solidification to occur, while immobilizing the lead
as well. This alternative will meet the Remedial Action Goals by
minimizing potential exposure by direct contact or inhalation, and
reducing the potential for migration of contaminants into the
surface waters and ground waters.
Implementation of this alternative will require demolition of some
structures on the site. Contaminated off-site soils from Parcel H
will be excavated and consolidated with the materials onsite. The
stabilization/ solidification process will require the addition of
kiln dust and lime, resulting in an increase of volume of waste to
be disposed by 30%. The total volume of treated waste is estimated
to be 54,600 cubic yards. There is an acceptable amount of
disposal capacity at the FSR site.
Containment Components: Consolidation of adjacent contaminated
soils will allow the stabilization/solidification process to be
centrally located on the lagoon site and reduce the area needed for
disposal. The estimated area necessary for disposal of the treated
waste is 2.4 acres, and will be capped and closed as a RCRA
Subtitle C landfill in accordance with the requirements specified
in 40 CFR 264.310 for landfill closure, which will require a cap to
have a permeability less than or equal to the permeability of the
natural underlying soil. Closure of the area would also comply
with the State of Oklahoma requirements. The cap will be designed
and constructed to promote drainage, minimize erosion of the cover,
and provide long-term minimization of migration of liquids through
the underlying contaminated soils. Consistent with the
requirements of 40 CFR 264.117, long-term operation and maintenance
(O&H) would be conducted to monitor the ground water around the
landfill and to ensure the integrity of the cap.
The stabilization/solidification process will be performed in-situ
with heavy construction equipment such as a backhoe and proceed
sequentially from one end of the lagoon to the other. Generally,
treatment of the waste material will be performed within the area
of contamination (sludge lagoon) followed by excavation,
stockpiling or placement in an area previously treated and
excavated to the remedial action objective. Throughout treatment,
a buffer zone will be maintained to separate treated material from
untreated material allowing complete treatment and excavation of
waste material in excess of the treatment standards. The above-
ground containment dikes will be reinforced structurally by the
same stabilization/ solidification process to support the final
50
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cover. Contaminated surface water will be utilized for dust
control and as an admixture with the stabilization/ solidification
reagent(s) to improve mixing efficiency. Capping the site will
eliminate the risk from direct contact and inhalation exposure.
The stabilization process will immobilize the contaminants and
minimize the potential for future ground water contamination.
General Components: The estimated time to implement this remedy
and to meet the cleanup levels is 24 months. The estimated costs
for this alternative are: Capital Costs: $4,900,000; Annual
Operation and Maintenance Costs: $10,000; Present Worth:
$5,100,000.
Alternative 4: On-site Stabilization and Disposal in an On-site Landfill
Manor Components of the Remedial Alternative. The major features of
this alternative 4 consists of neutralization of the acidic waste
and immobilization of the inorganic contaminants in place with
stabilization/solidification technology, excavation of the
neutralized waste, construction and placement of approximately
54,600 cubic yards of the treated waste into a new on-site landfill
with a cap system, meeting the requirements of the RCRA Subtitle D
regulations, 40 CFR Part 258, backfilling the excavated areas,
installation of fencing and warning signs, deed notification,
perpetual maintenance and 5 year reviews. Perpetual maintenance is
required because the waste materials will remain on-site as a
result of this remediation effort.
Treatment Components: Alternative 4 utilizes the same
stabilization/ solidification technology as described under
Alternative 3, however the waste material will be encapsulated in
a new on-site landfill (bottom and cover) constructed meeting the
requirements of the RCRA Subtitle D regulations. The RCRA Subtitle
C cap utilized in Alternative 3 is deleted from this alternative in
favor of the base liner and capping requirements identified under
Subtitle D. The RCRA Subtitle D criteria are typically associated
with municipal solid waste landfills, and is appropriate because
the stabilization process will remove the hazardous characteristics
of the waste.
Upon neutralization of the waste utilizing stabilization/
solidification technology, the resulting waste mass is assumed to
be a nonhazardous waste by not exhibiting the hazardous corrosivity
characteristic or exceeding the limitations identified in the
Toxicity Characteristic Leaching Procedure rule. Treatability
studies, as described in Alternative 3, indicate that
stabilization/ solidification to meet these criteria can be
accomplished. By meeting these two criteria, the waste may be
deposited in a Subtitle D landfill. The alternative description
for the remaining portions of Alternative 4 will apply to this
alternative. However, stockpiling of treated material will be
necessary prior to placement in the landfill.
53
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Containment Components: The additional requirements associated with
this alternative involve the construction of a new on-site landfill
meeting the RCRA Subtitle D requirements identified under 40 CFR
Part 258 (Subpart D) . A RCRA Subtitle D landfill incorporates the
use of a single composite bottom liner system or an alternate
bottom liner system meeting the performance requirements identified
in 40 CFR Part 258. The RCRA Subtitle D requirements identified
under 40 CFR Part 258 have been approved by EPA. These
requirements are not presently effective, but are expected to be
effective before disposal activities will be accomplished. The
State of Oklahoma is currently seeking approval of their revised
Subtitle D permitting program. A composite liner system consists
of two components; the upper component must be a minimum 30-mil
flexible membrane liner, and the lower component must be of at
least a two-foot layer of compacted soil with a hydraulic
conductivity of no more than 1 x 10"7 cm/sec. The composite liner
system decreases the potential for leachate to escape the contained
landfill cell.
The cover system will meet the requirements outlined in 40 CFR Part
258.60, Closure and Post-Closure Care, and will be comprised of an
erosion layer underlain by an infiltration layer comprised of a
minimum of 18 inches of earthen material that has a permeability
less than or equal to the permeability of the bottom liner system
or natural subsoils present, or a permeability no greater than 1 x
10"5 cm/sec., whichever is less. Upon completion of the landfilling
operation, portions of the site area unused by the on-site landfill
will be backfilled with clean imported fill material. As
previously described under Alternative 3, contaminated surface
water will be utilized in the stabilization/ solidification
process.
Implementation of this alternative will require demolition of the
on-site equipment, tankage and structures, to provide sufficient
area for construction of the new landfill cell. Demolition of the
site structures will provide sufficient area to stockpile treated
material prior to construction of the landfill and placement of the
treated material into the landfill. The new landfill cell will
utilize approximately 4 acres, at a depth of 10 feet, with the
bottom of the landfill cell a minimum of 5 feet above the seasonal
high groundwater elevation. Since the depth of the sludge lagoon
is within 5 feet of groundwater, a 5 foot layer of fill material
will be placed in the excavated sludge lagoon area prior to
construction of the landfill. The landfill cover will eliminate
the risk from direct contact and inhalation exposure. The
stabilization process will immobilize the contaminants and minimize
the potential for future ground water contamination.
General components: The estimated time to implement this remedy and
to meet the cleanup levels is 24 months. The estimated costs
associated with implementing Alternative 4 are: Capital Costs:
$7,100,000; Annual Operation and Maintenance: $10,000; Present
Worth: $7,300,000.
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Alternative 5: On-site Stabilization and Disposal in an Off-site Landfill
Major Components of the Remedial Alternative. The major features of
Alternative 5 involves the neutralization of acidic waste and
immobilization of inorganic contaminants in place utilizing
stabilization/solidification technology, excavation and shipment of
approximately 54,600 cubic yards of the non-hazardous waste to a
commercial landfill, and backfilling the excavated area with clean
imported fill material. This alternative would constitute a clean
closure for the site and would not necessitate fencing, warning
signs, deed notices, perpetual maintenance or 5 year reviews.
Containment Components: Alternative 5 is the same as Alternative 4,
except this alternative involves disposing the wastes at a
permitted off-site landfill meeting the requirements of RCRA. The
off-site materials on Parcel H will be excavated and consolidated
with the material onsite for treatment. Implementation of this
alternative will require demolition of above-ground structures
onsite. Material will be neutralized and stabilized/ solidified to
remove the hazardous corrosivity characteristic of the waste, and
exceedance of the toxicity regulatory limits set in 40 CFR Part
261.24 (Toxicity Characteristics Leaching Procedure). By meeting
these two criteria, the waste may be deposited in an off-site
Subtitle D landfill meeting the RCRA requirements identified under
40 CFR Part 258 (Subpart D). Off-site transportation of the
treated waste will be in accordance with the applicable Department
of Transportation regulations. Waste not treated to remove the
corrosivity or that exceeds the toxicity regulatory limits after
treatment will require disposal at a RCRA Subtitle C facility.
Addition of the neutralizing reagents will increase the volume of
waste material to be disposed by approximately 30%. As previously
described under Alternative 3, contaminated surface water will be
utilized in the stabilization solidification process.
The neutralized and conditioned waste material will be excavated,
loaded on trucks and transported to a permitted off-site facility,
meeting the requirements of a RCRA Subtitle D landfill, and
disposed. Excavated areas on and off-site would be backfilled,
graded, and revegetated.' Backfill materials will consist of clean
imported material. The risk from direct contact and inhalation
exposure, and the potential for future ground water contamination
will be eliminated by completely removing the waste from the FSR
site.
General Components: The estimated time to implement this remedy and
to meet the cleanup levels is 24 months. The estimated costs
associated with implementing Alternative 5 are: Capital Costs:
$6,400,000; Annual Operation and Maintenance: None; Present Worth:
$6,400,000.
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Alternative 6: Excavation. On-site Incineration, and On-site Capping of Ash
Manor Components of the Remedial Alternative; The major features of
this alternative involves the consolidation of off-site waste, as
discussed in previous alternatives, neutralization of acidic waste
in place utilizing stabilization/solidification technology,
treatment of the waste in an on-site incinerator for the
destruction of organics, stabilization and disposal of residual
ash, installation of a RCRA Subtitle C cap, fencing, warning signs,
deed notification, perpetual maintenance and 5 year reviews.
Perpetual maintenance is required because the waste materials
(metals) will remain on site as a result of this remediation
effort.
Treatment Components: Alternative 6 involves the on-site
neutralization, excavation and destuction of the organic
contaminants of the waste material in a transportable on-site
incinerator, on-site stabilization/ solidification and disposal of
the incineration residues and backfill of the unused excavated area
with clean imported fill. Neutralization is required due to the
corrosivity characteristic of the waste and its effect on the
incineration equipment. Operation of the incinerator would be in
accordance with RCRA (40 CFR 264 Subpart O).
Several forms of transportable incinerators are presently available
for the treatment of CERCLA wastes. Many are equipped with high
efficiency, off-gas scrubbers and particulate removal systems
essential for the compliant treatment of the Fourth Street wastes.
High efficiency emission control systems may be a major factor to
evaluate due to considerable lead contamination. Lead in the
wastes will volatilize at temperatures below those of an operating
hazardous waste incinerator and will be entrained in the off-gas
process stream. High efficiency off-gas scrubbing systems are
capable of precipitating the metal from the gas stream and removing
it as a blowdown solid. The transportable incineration processes
that are applicable for the on-site treatment of the Fourth Street
wastes include rotary kilns, circulating bed combustors and
infrared furnaces. These systems are similar in operational
characteristics as those found at permanent installations. Process
units are skid mounted for transportation and are connected
together when mobilized to the site. Selective demolition and
disposal of on-site equipment and tankage is required to
accommodate a transportable incinerator, off-gas scrubbing system,
blowdown water treatment facilities, materials handling
(pretreatment) units and other ancillary equipment necessary for
effective and efficient operations. The total area required for
the incinerator and ancillary equipment is approximately 3 acres.
Containment Components: Residues from the incineration process,
including ash and scrubber blowdown solids, would contain
concentrated levels of heavy metals and would therefore, require
stabilization prior to on-site disposal. Based on current analyses
of the Fourth Street wastes, it is estimated that through
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incineration, the volume of waste would be reduced to approximately
15,000 cubic yards of residual ash and soil. If a bulking factor
of approximately 30% is assumed for the addition of stabilization
additives, a total of approximately 20,000 cubic yards of material
would be backfilled onsite. Additionally, approximately 22,000
cubic yards of clean fill would be imported in order to restore the
Fourth Street site to current elevations. A RCRA Subtitle C cap
would be installed over the backfilled waste, because of the lack
of a bottom liner containment system beneath the waste. The
Subtitle C cap would be designed and constructed in accordance with
the requirements specified under 40 CFR 264. Contaminated surface
water and blowdown water from the scrubber system will be utilized
for dust control and as an admixture with the
stabilization/solidification reagent to improve mixing efficiency.
Closure of the site would necessitate fencing, signs, deed notice,
perpetual maintenance and five year reviews.
The landfill cover will eliminate the risk from direct contact and
inhalation exposure. The stabilization process will immobilize the
contaminants and minimize the potential for future ground water
contamination.
General Components: The estimated time to implement this remedy and
to meet the cleanup levels is 24 months. The estimated costs
associated with implementing Alternative 6 are: Capital Costs:
$32,400,000; Annual Operation and Maintenance: $10,000; Present
Worth: $32,600,000.
Alternative 7: Excavation. Off-site Incineration and Disposal of Ash
Major Components of the Remdial Alternative; The major features of
this alternative involves consolidation of waste from Parcel H , as
previously discussed, the neutralization of acidic waste in place
utilizing stabilization/solidification technology, excavation and
shipment of neutralized waste to a commercial facility for the
thermal destruction of organic contaminants, stabilization and
disposal of residual ash. The excavated areas of the site would be
backfilled, with clean imported material. This alternative
provides for clean closure of the site and would not require the
items required under Alternative 2, Limited Action.
Treatment Components: Alternative 7 involves the neutralization and
excavation of waste on the Fourth Street site, followed by
transportation to an off-site thermal treatment or energy recovery
facility. The excavated areas will be filled with clean imported
backfill. Clean closure of the site would not necessitate fencing,
signs, deed notice, perpetual maintenance or a five year review.
Several forms of thermal destruction are presently available for
the treatment of CERCLA wastes. Numerous facilities exist
throughout the country where both the thermal destruction of the
waste organic constituents and the disposal of the residual ash
could be achieved. Other facilities, although capable of thermally
processing the waste would be required to address the ultimate
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disposal of residuals. Operation of the incinerator would be in
accordance with RCRA (40 CFR 264 Subpart O).
Wastes on the Fourth Street site will require pretreatment for
neutralization in order to make them acceptable for off-site
transport and/or to meet the requirements of a thermal treatment or
energy recovery facility. Off-site contaminated soils from Parcel
H and the on-site contaminated soils will be consolidated with the
tar material onsite. Soils, sediments and sludges would be
neutralized in situ, and then excavated for loading and transport.
Contaminated surface water will be utilized in the neutralization
process. Transportation of waste materials to a permitted off-site
facility will be in compliance with DOT regulations (i.e.,
placards, proper shipping containers, etc.). Selective demolition
of on-site equipment and tankage will be required to implement the
neutralization and excavation operations. Although dependent on
the progress of the neutralization effort, it is estimated that the
final excavation and transport of the waste on the Double Eagle
site would take approximately 6 to 8 months.
Once received at the off-site thermal treatment facility, bulk
waste would be unloaded for temporary RCRA compliant storage or
directly fed to the treatment unit. This alternative also
incorporates co-combustion of the waste, or use of the waste as
fuel in devices whose primary purpose is energy production, such as
boilers, furnaces, and process heaters. The thermal treatment
processes provide high temperature destruction of organics in the
waste and scrubbing of the combustion gases. The thermal treatment
processes that are applicable for the treatment of the Fourth
Street waste include rotary kilns, pyrolysis, circulating bed
combustors, infrared furnaces and some industrial installations
(boilers, kilns and furnaces). Thermal destruction is a treatment
process employed to destroy organic contaminants in liquid, gaseous
and solid waste streams. Thermal treatment will not destroy
inorganic contaminants such as lead, therefore, the ash residue
must be stabilized prior to disposal.
The operation of a thermal system results in generation of
residual/effluent streams consisting of ash, decontaminated soils
(if soils are present in the feed stream) , scrubber water or
blowdown, and flue gases. A detailed waste analysis is required
before a waste is accepted by a treatment/disposal facility. Among
the most important factors which a facility owner considers in
determining the suitability of wastes for thermal treatment
include: BTU content of the waste, viscosity, water content,
halogen content and ash content.
Containment Components: Based on current analyses of the Fourth
Street wastes, it is estimated that through thermal treatment the
volume of waste would be reduced to approximately 20,000 cubic
yards of residual ash, soil and bulking reagent. Because of the
heavy metal (lead) content of these residuals and solids generated
from the facility's air pollution control system, stabilization
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would be required prior to final disposition in a landfill. The
treated material would have to meet the TCLP requirements
previously discussed prior to landfill disposal. Several
alternative thermal destruction options are available for the waste
at the Fourht Street site. The risk from direct contact and
inhalation exposure, and the potential for future ground water
contamination will be eliminated by completely removing the waste
from the FSR site.
General Components: The estimated time to implement this remedy and
to meet the cleanup levels is 12 months. The estimated costs
associated with implementing Alternative 7 are: Capital Costs:
$23,900,000; Annual Operation and Maintenance: None; Present Worth:
$23,900,000.
PL SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
The EPA uses nine criteria to evaluate alternatives for addressing
a Superfund site. These nine criteria are categorized into three
groups: threshold, primary balancing, and modifying. The threshold
criteria must be met in order for an alternative to be eligible for
selection. The primary balancing criteria are used to weigh major
tradeoffs among alternatives. The modifying criteria are taken
into account after state and public comment is received on the
Proposed Plan of Action.
Nine Criteria
The nine criteria used in evaluating all of the alternatives are as
follows:
a) Threshold Criteria
Overall Protection of Human Health and the Environment addresses
the way in wich an alternative would reduce, eliminate, or control
the risks posed by the site to human health and the environment.
The methods used to achieve an adequate level of protection vary
but may include treatment and engineering controls. Total
elimination of risk is often impossible to achieve. However, a
remedy must minimize risks to assure that human health and the
environment are protected.
Compliance with ARARs. or "applicable or relavent and appropriate
requirements11, assures that an alternative will meet all related
federal, state, and local requirements.
b) Primary Balancing Criteria
Long-term Effectiveness and Permanence addresses the ability of an
alternative to reliably provide long-term protection for human
health and the environment after the remediation goals have been
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accomplished.
Reduction of Toxicity. Mobility, or Volume of Contaminants through
Treatment assesses how effectively an alternative will address the
contamination on a site. Factors considered include the nature of
the treatment process; the amount of hazardous materials that will
be destroyed by the treatment process; how effectively the process
reduces the toxicity, mobility, or volume of waste; and the type
and quantity of contamination that will remain after treatment.
Short-term Effectiveness addresses the time it takes for remedy
implementation. A potential remedy is evaluated for the length of
time required for implementation and the potential impact on human
health and the environment during implementation.
Implementabilitv addresses the ease with which an alternative can
be accomplished. Factors such as availability or materials and
services are considered.
Cost (including capital costs and projected long-term operation and
maintenance costs) is considered and compared to the benefit that
will result from implementing the alternative.
c) Modifying Criteria
State Acceptance allows the state to review the proposed plan and
offer comments to the EPA. A state may agree with, oppose, or have
no comment on the proposed remedy.
Community Acceptance allows for a public comment period for
interested persons or organizations to comment on the proposed
remedy. EPA considers these comments in making its final remedy
selection. The comments are addressed in the responsiveness
summary which is a part of this ROD.
Comparative Analysis
The following discussion provides the comparative analysis for each
of the nine criteria:
1. Overall Protection of Human Health and the Environment
All of the alternatives, except No Action, will provide some degree
of overall protection of human health and the environment. The
degree to which each alternative provides this protection is
discussed below.
The No Action alternative provides no increase in the overall
protection to human health and the environment. Under this
alternative, all of the potential risks to human health and the
environment associated with the FSR site would remain.
Alternative 2, Limited Action, will eliminate the risk associated
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with the contaminated material on Parcel "H" since this material
will be excavated, placed on site and replaced with clean fill.
Direct contact with material on site will be reduced as long as the
fences are maintained trespassers are kept away from the site. The
risk associated with potential air emissions will not be reduced,
nor will this alternative address the potential risk to future
workers on site.
Alternative 3, On-site Stabilization/ On-site Capping, will
eliminate the offsite direct contact risk Parcel H similarly to
the Limited Action Alternative. This alternative will also reduce
the risk from direct contact with the sludges and soils onsite by
covering the stabilized material with a cap. The cap will also
eliminate the potential for air emissions from the site. Some risk
from direct contact and migration to the ground water may remain
from possible failure of the cap; however, the potential for
failure would be minimized by proper annual maintenance.
Alternative 4, On-site Stabilization/On-site Landfill Disposal,
offers levels of overall protection similar to the capping
alternative. However, this alternative provides an additional
level of protection to the ground water by the construction of a
liner beneath the stabilized material. This liner will minimize
the possibility that contaminants can migrate to the ground water
under the site.
The On-site Stabilization/Off-site Landfill Disposal and Off-site
Incineration alternatives, Alternatives 5 and 7, provide
protection of human health and the environment by the ultimate
removal of the contaminated material from the site. Because the
material would be removed, the potential for migration to ground
water and for air emissions would be eliminated.
The risk associated with contact with material on Parcel "H" will
be eliminated by Alternative 6, since this material will be
excavated and replaced with clean soil. The risk associated with
exposure to the organic contaminants will be eliminated by
destruction of these contaminants. Exposure to lead on the Double
Eagle property will be reduced by this alternative by the
stabilization and capping of the metal-contaminated ash from the
incinerator.
2. Compliance with Applicable or Relevant and Appropriate
Requirements (ARARS)
Contaminated material stabilized on-site will have to be treated to
the extent that it is no longer considered a RCRA characteristic
hazardous waste (40 CFR 261). All of the stabilization
alternatives will attain this degree of treatment. The
alternatives involving incineration will be required to meet the
standards set by the federal government for the operation of
hazardous waste incinerators (40 CFR 264 Subpart 0). The
alternatives involving landfill disposal will be required to meet
the standards for landfill construction and operation set by the
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federal government (40 CFR 264 Subpart N).
3. Long-term Effectiveness and Permanence
The No Action and Limited Action alternatives would not provide
long-term effectiveness or a permanent solution to potential risks
associated with material onsite. However, Limited Action would
eliminate the risk from Parcel "H" by excavating the contaminated
material in these areas and backfilling with clean soil.
Alternative 3 provides a higher degree of long-term effectiveness
and permanence by physically and chemically binding the
consolidated waste material into a stabilized mass, and covering
the treated material with an impermeable cap. The effectiveness
and permanence of this alternative depends on the perpetual
maintenance of the cap. Alternative 4 provides even greater
effectiveness through the construction of a liner to collect any
leachate generated on site, thereby protecting the ground water.
The overall effectiveness and permanence of this alternative also
depends on perpetual maintenance of the cap.
On-site incineration will provide the greatest degree of long-term
effectiveness and permanence of the on-site alternatives evaluated,
by destroying the organic contaminants in the waste, eliminating
the risk from the polynuclear aromatic hydrocarbons at the site.
Permanence of this alternative will depend on perpetual
maintenance of the cap over the stabilized, metal contaminated
residual from the incinerator.
The Off-site Landfill and Off-site Incineration alternatives
provide the greatest degree of long-term effectiveness and
permanence since the contaminants are removed from the site and no
maintenance actvities would be necessary.
4. Reduction of Toxicity, Mobility or Volume Through Treatment
The No Action and Limited Action alternatives do not provide any
treatment to reduce the toxicity, mobility, or volume of the
contaminated material. Alternatives 3, 4, and 5 use treatment to
reduce the mobility of the metals and, to a lesser degree, the
mobility of the organic contaminants. The volume of material would
increase approximately 30%, by the addition of the neutralization/
stabilization reagents. Alternatives 6 and 7 would reduce the
toxicity and volume of contaminated material through the
destruction of the organics. Following treatment of the organic
material, the mobility of lead would be reduced by stabilization of
the ash.
5. Short-Term Effectiveness
There would be no short-term risks associated with construction
under the no action alternative. However, the risks currently
associated with wastes at the site would remain. There would be
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potential short-term risks to site workers during the consolidation
of the material from Parcel "H" and from the transportation of the
excavated material to the site area associated with Alternatives 2,
3, 4, and 6. Some increase in air emissions may occur because of
excavation and during the stabilization process onsite. However,
engineering controls and monitoring will reduce the potential for
any adverse impacts during implementation of the remedy. Air
pollution emissions can be detected very quickly with standard
industrial hygiene monitoring equipment and visible monitoring. A
contingency plan would be developed to address any potential air
emissions during remedial activities. Alternatives 5 and 7 also
have short-term risks associated with the transportation of wastes
to an off-site facility. These risks can be significantly reduced
by a detailed transportation/ spill prevention plan. The estimated
time to implement Alternatives 3, 4, and 5 is 24 months. The
estimated time to implement Alternatives 2, 6, and 7 is 12 months.
6. Implementability
Treatability studies conducted on material from the FSR site
indicate that stabilization (Alternatives 3, 4, and 5) would
effectively immobilize and address the hazardous charateristics of
the contaminated materials at the site. The concentration of
organic chemicals is sufficiently low that stabilization is not
inhibited. The construction of a cap (Alternative 3) over the
treated material would be easily implemented. Alternatives 5, 6,
and 7 are also easily implementable. However, the implementability
of Alternatives 5 and 7 will depend upon the availability of
facilities that are compliant with the Superfund Off-site Disposal
Policy Construction of a landfill on-site (Alternative 4) would
require the demolition of several of the site structures in
addition to the tanks and process equipment. An area to store
excavated material during on-site landfill construction would also
be required.
7. COSt
The present worth cost of the preferred alternative is $6,400,000.
The Limited Action and Onsite Capping alternatives have lower
present worth costs of $300,000 and $5,100,000, respectively. On-
site Treatment and disposal in an on-site landfill is slightly
higher with a cost of $7,300,000. Onsite and Offsite Incineration
are the most expensive alternatives; $32,600,000 and $29,400,000,
respectively.
8. State Acceptance
The Oklahoma State Department of Health (OSDH) has reviewed the
alternatives and does not believe that the No-Action and Limited
Action alternatives (1 and 2) are acceptable. OSDH does not
believe that Alternative 3 will provide adequate protection of the
ground water because of the uncertainty associated with the depth
of waste on site. The State does not believe that incineration
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(Alternatives 6 and 7) of the waste is appropriate because it would
not address the risk associated with the lead at the FSR site.
The OSDH does not have a technical objection to Alternative 4,
which is EPA's preferred alternative and was the Proposed Plan for
public comment. However, prefers Alternative 5, Neutralization.
StabilizationT and Off-site Landfill disposal. The State of
Oklahoma prefers this alternative because 1) the cost of the
alternative and subsequent 10% State match, is lower than
Alternative 4, and 2) long term operation and maintenance would not
be required because all of the contaminated material would be
removed from the site.
9. Community Acceptance
Comments received during the public comment period indicated a
preference for off-site disposal, although one commenter indicated
that off-site incineration was most preferable. Other commenters
suggested that technologies other than landfill disposal and
incineration should be developed. All comments received during the
public comment period and EPA responses are in the attached
Responsiveness Summary.
X. THE SELECTED REMEDY
Based upon consideration of the requirements of Super fund, the
detailed analysis using the nine criteria, and the public comments,
EPA has determined that Alternative 5 - Neutralization, Excavation,
On-site stabilization, and Off-site Landfill Disposal of the
stabilized material is the most appropriate remedy for the FSR
site. The major componenets of this remedy include:
Excavation of the contaminated material on Parcel "H"
(approximately 1,200 cubic yards)
Consolidation of this material with the contaminated material
on the FSR property
Demolition of onsite structures and disposal of the asbestos
insulation, as necessary
- Use of the surface water in the impoundments in the
stabilization process
On-site stabilization of 42,000 cubic yards of the
consolidated material to immobilize and address the hazardous
characteristics of the contaminants
Disposal of the stabilized material in a fully permitted off-
site landfill
The principal threat at the FSR site is posed by direct contact and
inhalation of contaminants in site soils and sludges, and potential
for migration of contaminants to the ground water. The remedial
objectives are to minimize potential exposure by direct contact or
inhalation, and to reduce the potential for migration of
contaminants into the surface waters and ground waters.
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This alternative will significantly reduce the risks from direct
contact with the sludges, soils and sediment at the FSR site by
stabilizing and isolating the contaminants in an off site landfill
permitted to accept this type waste. Since all of the material
contaminated above EPA's remedial action goals (lead, 500 ppm;
PAHs, 30ppm; PCBs 25ppm) will undergo treatment and be isolated in
an off-site landfill, the long-term effectiveness is better than
for the stabilization and capping alternative. This alternative
will also comply with all ARARs for stabilization and off-site
landfill disposal. The consolidated material will be stabilized to
ensure that leaching of COCs does not exceed the TCLP regulated
standards listed in 40 CFR 261.24. On-site stabilization and off-
site landfill disposal uses treatment technologies and permanent
solutions to the maximum extent practicable and is cost effective,
offering a degree of protection similar to the incineration
alternatives at a lower cost. The selected alternative will also
satisfy the preferences for treatment as a principal element of the
remedy and for on-site remedies written in the Superfund law.
The No Action and Limited Action alternatives (Alternatives 1 and
2) are not being considered at this time because neither
alternative provides for overall protection of human health and the
environment. The Onsite Stabilization/Capping alternative
(Alternative 3) presents technical issues due to the uncertainty of
treating contaminated material near the bottom of the impoundments
onsite without excavation of the material. The selected remedy
does not satisfy the preference in the Superfund law for onsite
remedies. However, it is more cost-effective than the onsite
disposal alternative, and preferred by the State of Oklahoma. The
onsite and off site incineration alternatives (Alternatives 6 and 7)
are much less cost effective than the preferred alternative.
Because each would require stabilization of the incinerator ash
prior to disposal, EPA does not believe that the incinerator
alternatives offer additional protection in line with the
additional cost.
The selected remedy uses treatment and permanent solutions to
address the risks posed by the COCs at the site to the maximum
extent practicable. The selected remedy does not, however, satisfy
the preference in SARA for on-site remedies. EPA's original
proposed plan, Alternative 4, would satisfy this preference in the
law. However, EPA is deferring its preference in consideration of
public comments and the State of Oklahoma's comments. The selected
remedy will be less costly and not require expenditure of State or
EPA funds for operation and maintenance.
Upon completion of the remedial action, future source control
operation and maintenance activities will not be required, since
all of the wastes will be removed from the site.
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XL THE STATUTORY DETERMINATIONS
EPA's primary responsibility at Superfund sites is to select
remedial actions that are protective of human health and the
environment. Section 121 of CERCLA also requires that the selected
remedial action for the site comply with applicable or relevant and
appropriate environmental standards established under Federal and
State environmental laws, unless a waiver is granted. The selected
remedy must also be cost-effective and utilize treatment or
resource recovery technologies to the maximum extent practicable.
The statute also contains a preference for remedies that include
treatment as a principal element. The following sections discuss
how the selected remedies for contaminated soils, sediments and
sludges at the FSR site meet the statutory requirements.
Protection of Human Health and the Environment
In order to protect human health and the environment, the
contaminated soils, sediments, sludges, and ground water that
exceed RAOs will undergo a combination of excavation, treatment and
disposal. These media will be treated and contained to meet the
performance standards set forth in this ROD. These performance
standards will assure that site risks fall within the target cancer
risk range of 10"* to 10"6 and the non-carcinogenic hazard index will
be reduced to less than one (1). The performance standards will
also assure that 1) direct contact with contaminated sediments,
sludges, and surface soils will cease, and 2) contaminated
sediments, sludges, and surface soils will cease to act as a source
of ground water contamination.
The selected remedy protects human health and the environment by
reducing levels of contaminants through treatment and disposal. Of
all the alternatives evaluated for the contaminated sediments,
sludges, and soils, the selected alternative provides the best
overall protection to human health and the environment. No
unacceptable short-term risks will be caused by implementing this
remedy.
Compliance with ARARs
The selected sediment, sludge and surface soil remedy, which
utilizes excavation, consolidation, neutralization and
stabilization, and ultimate disposal will comply with all
applicable or relevant and appropriate requirements. The ARARs are
presented as follows:
Chemical-Specific ARARs for Softs and Sediments
l. Identification and Listing of Hazardous Waste (40 CFR Part
261), Subpart C - Characteristics of Hazardous Waste and Subpart D
- Lists of Hazardous Waste. Applicable because characteristically
hazardous waste will be managed.
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2. National Emission Standards for Hazardous Air Pollutants (40
CFR Part 61). Relevant and appropriate during excavation,
neutralization and stabilization processes.
3. Air Pollution Permits (Oklahoma Air Pollution Control Rules,
OAC 310:200-7). Applicable during excavation, neutralization and
stabilization processes if emissions exceed one pound per hour for
any one criteria pollutant.
4. Control of Emissions of Organic Materials (Oklahoma Air
Pollution Control Rules/ OAC 310: 200-37). May be applicable
depending on the specific air emissions during biotreatment,
neutralization and stabilization processes.
5. Control of Emission of Hazardous and Toxic Air Contaminants
(Oklahoma Air Pollution Control Rules/ OAC 310:200-41). May be
applicable depending on the specific air emissions during
excavation, neutralization and stabilization processes.
Action-Specific ARAR for Soils, Sludges and Sediments
Standards for Owners and Operators of Hazardous Waste Treatment/
Storage/ and Disposal Facilities (40 CPR Part 264). Relevant and
appropriate during excavation, neutralization and stabilization
processes.
Cost-Effectiveness
EPA believes that the selected remedy is cost-effective in
mitigating the threat of direct contact with site wastes. Section
300.430 (f) (ii) (D) of the NCP requires EPA to determine cost-
effectiveness by evaluating the following three of the five
balancing criteria to determine overall effectiveness: long-term
effectiveness and permanence, reduction of toxicity, mobility or
volume through treatment, and short-term effectiveness. Overall
effectiveness is then compared to cost to ensure that the remedy is
cost effective. EPA believes the selected remedies meet these
criteria. The estimated present worth cost for the selected SCOU
remedy is $6,400,000.
Utilization of Permanent Solutions and Treatment or Resource Recovery Technologies to the
Maximum Extent Practicable
EPA believes the selected remedy represents the maximum extent to
which permanent solutions and treatment/resource recovery
technologies can be utilized in a cost-effective manner for the FSR
site. Of those alternatives that are protective of human health
and the environment and comply with ARARs, EPA and OSDH have
determined that the selected remedies provide the best balance in
considering long-term effectiveness and permanence; reduction in
toxicity, mobility or volume through treatment; short-term
effectiveness; implementability; and cost, as well as considering
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the statutory preference for treatment as a principal element and
considering state and community acceptance.
Preference/or Treatment as a Principal Element
The selected remedy satisfies the statutory preference for
treatment as a principal element. The Source Control remedy will
use stabilization/solidification, and neutralization as treatment
methods .
DOCUMENTATION OF SIGNIFICANT CHANGES; A Proposed Plan for
the FSR site was released for public comment on July 17, 1992. The
Proposed Plan identified Alternative 4, Consolidation,
Neutralization, On-site Stabilization and On-site Landfill Disposal
as EPA's preferred alternative for soil, sludge, and sediment
contamination. At the same time, EPA requested the preference of
the State of Oklahoma regarding the Proposed Plan. In a letter
dated August 18, 1992, (Attachment C) the OSDH indicated that the
State of Oklahoma preferred Alternative 5 - Consolidation,
Neutralization, On-site Stabilization, and Off-site Landfill
Disposal. OSDH cited the lower cost of the remedy and subsequent
lower State match. As a result of State and general public
comments, EPA has decided to select off-site landfill disposal
rather than on-site landfill disposal for the FSR site.
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ATTACHMENT C
Joan K. LeaviH, M.D.
Commissioner DEPARTMENT
Board of Health 1QQO JMi TENT
John B. Carmichael, D.D.S. Gordon H. Deckert, M.D. OKUVHOMA&fYpO
President Dan H. Fieker, D.O. 73117-1299
ErnestD. Martin, R.Ph. Linda M. Johnson, M.D. HA2t'-?! n-;:- -V^r1:
Vice President Walter Scott Mason, III '
Burdge F. Green, M.D. Lee W. Paden
Secretary-Treasurer
August 4, 1992
Mr. Allyn Davis, Director
Hazardous Waste Management Division (6H)
U.S. Environmental Protection Agency
1445 Ross Ave, Suite 1200
Dallas, Texas 75202-2733
Dear Mr. Davis:
This letter is in reply to your letter of July 6,1992. Your letter requests that the Oklahoma
State Department of Health (OSDH) provide comments on the Proposed Plans for the
Double Eagle Refinery and the Fourth Street National Priorities List (NPL) sites. OSDH
prefers the onsite stabilization and neutralization of wastes followed by the disposal in an
offsite commercial landfill as nonhazardous waste. OSDH has no technical objection to the
onsite landfill recommended by EPA, but prefers the offsite landfill because the Feasibility
Study indicates a significantly higher cost for the onsite landfill.
The offsite landfill also has the advantage of saving taxpayers the cost of operation and
maintenance each year. EPA would not be required to conduct five-year reviews of the
remedy because the waste would be removed from the site.
Thank you for your time. If you wish to discuss these matters in more detail please call me at
(405)271-8056.
Sincerely,
Mark S. Coleman, Deputy Commissioner
Environmental Health Services
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