EPA Superfund
Record of Decision:
PB96-964204
EPA/ROD/R06-96/102
March 1997
Vertac Superfund Site,
Operable Unit 2, Jacksonville, AR
9/17/1996
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RECORD OF LECISION
VERTAC SUPERFUND SITE
JACKSONVILLE, ARKANSAS
OPERABLE UNIT #2
SOILS, FOUNDATIONS AND UNDERGROUND UTILITIES
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
SEPTEMBER 1996
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RECORD OF DECISION
CONCURRENCE DOCUMENTATION
FOR THE
VERTAC SUPERFUND SITE
OPERABLE UNIT #2
JACKSONVILLE, ARKANSAS
Philip H. Allen, P.E.
Site Remedial Project Manager
John Dugdale
Senior Attorney, 6SF-DL
Wren Stefager, CHuef
Arkansas/Oklahoma Section, 6SF-AO
Wilfianf K. Honker, Chief
Superfund AR/OK/TX Branch, 6SF-A
Mark Peyck^ Chief
Superfund Litigation and Enforcement Branch, 6SF-DL
.
- Myron Of Knudson, P.E., Director
Superfund Division, 6SF
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DECLARATION
VERTAC SUPERFUND SITE
RECORD OF DECISION
OPERABLE UNIT #2
SEPTEMBER 1996 >
SITE NAME AND LOCATION
Vertac Incorporated
Jacksonville, Arkansas
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action
for Operable Unit 2, Soils, Foundations and Underground
Utilities, for the Vertac Incorporated site (the site), located
in Jacksonville, Arkansas, whic" was chosen in accordance with
the Comprehensive Environmental Response, Compensation and
Liability Act (CERCLA), 42 U.S.C. S 9601 et seq.. and, to the
extent practicable, the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP), 40 CFR Part 300. This decision
is based on the administrative record file for this site.
The State of Arkansas fully supports this remedy, and a
concurrence letter from the Arkansas Department of Pollution
Control and Ecology (ADPC&E) can be found in Attachment C to this
Record of Decision (ROD).
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from
this site, 'f not addressed by implementing the response action
selected in this ROD, may present an imminent and substantial
endangerment to public health, welfare, or the environment.
DESCRIPTION OF THE SELECTED REMEDY
There are six operable units for the Vertac site. This ROD
for Operable Unit 2 (OU2) addresses the remediation of dioxin-
and herbicide-contaminated on-site soils and debris, of on-site
underground utilities, and of on-site building foundations and
curbs. This ROD also addresses the disposal of contiguous soils
and debris originally addressed by the Vertac Superfund Site Off-
Site Areas Record of Decision (ROD), dated September 27, 1990, in
which EPA had selected its preferred remedy for soils, sediments,
and sludges excavated or to be excavated from contiguous areas
adjacent to the site. That 1990 Off-Site Areas ROD had selected
on-site incineration as the remedy for the soils to be excavated
from the Rocky Branch Creek floodplain, the sediments removed
from sewage collection lines, and the sludges removed from the
sewage digester. Subsequent to executing the 1990 Off-Site Areas
ROD, EPA deferred addressing the disposition of the 1990 Off-Site
Areas ROD media so that its disposal would be consistent with the
disposal of similar media addressed in the RODs for OU1 and OU2.
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Finally, in 1990 Hercules, Inc., a party liable for site
response actions and costs, in 1990 had performed a removal
action in which it excavated and bagged, and then stored on-site,
dioxin-contaminated soils excavated from contiguous residential
areas. The 1993 ROD for OU1 expressly deferred the disposition
of those bagged soils until EPA selected a remedy for OU2. All
of the media addressed in this ROD constitute low level threat
media, and the remedy selected takes into account the reasonably
anticipated future land use for the site, which is
commercial/industrial. A brief description of the components of
the OU2 remedy follows:
On-Site Soils
The remedy selected for OU2 consists of the excavation and
consolidation within an on-site hazardous waste landfill that
meets the substantive requirements <-f Subtitle C of the Resource
Conservation and Recovery Act (RCRA), 42 U.S.C. S 6901 et seq..
of site soils and debris that contain dioxin contamination levels
at or above a 5 part per billion (ppb) cleanup level. Excavated
areas will be backfilled with clean fill, graded, and vegetative
cover will be established. Upon completion of the site
remediation, data indicate that the average dioxin concentrations
will be less than 1 ppb. This is due to the fact that a large
percentage of the site acreage contains dioxin levels well below
1 ppb.
The northern portion of the site, which is approximately 100
acres, never had been used for industrial operations and the
soils are less than 1 ppb dioxin. The northern portion of the
site will be unrestricted and will be available for
commercial/industrial redevelopment. The southern portion of the
site, which consists of about 93 acres, is where active
industrial activities had occurred and the highest concentrations
of dioxin contamination are found. Some segments of the southern
portion of the site will remain fenced and access will ba
restricted to on-site maintenance workers where existing landfill
areas exist, where the on-site hazardous waste landfill will be
located, where an active wastewater treatment plant is located,
and possibly where ground water extraction and containment wells
are likely to be situated as part of implementing the remedy for
ground water. EPA plans to execute the ROD for the ground water
operable unit (OU3) concurrently with the execution of this ROD.
Such restrictions on the southern portion of the site are
necessary to prevent trespass into and the disturbance of the
existing waste disposal areas that were created as a result of a
1984 order of the U.S. District Court for the Eastern District of
Arkansas, into the wastewater treatment plant, into the hazardous
waste landfill, and possibly around any future ground water
wells. The 1984 court order imposed the "Vertac Remedy," under
which the Vertac plant cooling water pond and the equalization
basin were closed and sediments from these units were removed and
placed into an excavated area where earlier operators had buried
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drums of waste. The burial area was capped, a French drain and
leachate collection system were installed around the burial
areas, and a wastewater treatment plant was constructed to treat
water from the French drain and storm water runoff. Ground water
monitoring wells were also installed and a ground water
monitoring program was initiated.
Notwithstanding the limitations of the 1984 Court-ordered
Vertac Remedy, the remedy selected herein provides a feasible
means of ensuring that the greatest amount of site acreage be
~eturned to commercial/industrial use upon completion of the
remedy by addressing low level threat wastes through
consolidating them on-site in a RCRA Subtitle C hazardous waste
landfill.
Crystalline Tetrachlorobenzene (TCB) and Soils Contaminated
w-'th TCB
In addition to addressing the dioxin contamination within
on-site soils and debris at 5 ppb and above, the remedy selected
for OU2 will address crystalline tetrachlorobenzene (TCB) and
soils having TCB contamination above a 500 parts per million
(ppm) action level. This contamination exists in a small area of
the central process area of the site where some time during
active site operations a TCB spill had occurred from a rail car
parked at an on-site siding. Therafore, the remedy calls for the
excavation of crystalline TCB material and TCB-contaminated soils
where the TCB concentration exceeds 500 ppm. EPA's risk
assessment has established that soils containing TCB
concentrations below 500 ppm do not pose an unacceptable risk to
future site workers or occasional bypassers. Both the excavated
crystalline TCB material and the TCB contaminated soils will be
taken off-site for treatment by incineration at a compliant RCRA-
regulated facility.
Bagged Residential Soils from a 1990 Removal Action
In 1990, Hercules, Inc., conducted a removal action
involving the excavation of dioxin-contaminated soils from
contiguous residential areas where the dioxin concentrations were
1 ppb or greater. The 1993 ROD for OU1 deferred the treatment
decision for those soils, and the soils have been stored on-site
in bags until a decision on the remedy for similar on-site OU2
soils would be made. The total volume of bagged soil is
estimated at 2,770 cubic yards, and the remedy selected in this
ROD calls for the on-site consolidation within the RCRA Subtitle
C landfill.
Vertac Off-Site Areas ROD Soils. Debris, and Sludges
The remedy selected in the 1990 Off-Site Areas ROD specified
the removal of sediments from the active sewer interceptor and
the installation of pipe liners in the clean sewer, the filling
of the abandoned interceptor with grout, the removal of sludge
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from the sludge digester in the old wastewater treatment plant,
the capping of the sludge drying beds in the old wastewater
treatment plant with one foot of clean soil, the draining of an
aeration basin in the old wastewater treatment plant, the
demolition of the berm and capping of the basin with one foot of
clean soil, and the excavation of Rocky Branch Creek flood plain
soils that are contaminated with dioxin at 1 part per billion
(ppb) and greater. That ROD also selected on-site incineration
of those excavated soils, sediments and sludges, and monitoring
the Rocky Branch Creek and Bayou Meto fish for dioxin.
Under the terms of a Unilateral Administrative Order (UAO)
issued to Hercules, Inc. pursuant to CERCLA Section 106, 42
U.S.C. S 9606; in July 1993, Hercules, Inc., has completed the
performance of the 1990 ROD's off-site remedial actions except
for the excavation of the Rocky Branch Creek flood plain soils
and the on-site incineration of sorUnents removed from sewage
collection lines, sludge removed from the digester, and the as-
yet unexcavated Rocky Branch Creek soils. The removed sediments
and sludge are currently stored on-site. Subsequent to issuing
the 1990 Off-Site Areas ROD, EPA determined that the off-site
soils and debris are similar in their physical characteristics
and in the nature and extent of contamination in that they all
constitute low level threat media. For that reason, EPA
concluded that it was appropriate to defer the disposal of the
off-site soils and debris to ensure that such disposV vould be
consistent with that of the on-site soils.
Both EPA's original Proposed Plan for the Vertac Operable
Unit 2, presented to the public on May 25, 1995, and the
Supplemental Proposed Plan for OU2, presented to the public on
March 5, 1996, stated that EPA intended to address the disposal
of the _,(90 Off-Site Areas ROD wastes as a component of the OU2
remedy. In addition, both proposals indicated that EPA's
preferred remedy for those off-site soils and debris was on-site
consolidation within the RCRA Subtitle C landfill due to their
similarity to OU2 contaminated media. Therefore, the public had
two opportunities to comment on this change to the remedy
selected in the 1990 Off-Site Area*? ROD. During those two
comment periods, EPA received no adverse comments to that aspect
of the proposals.
Therefore, in the absence of adverse comment, EPA has
amended the 1990 Off-Site Areas ROD and hereby incorporates the
change in the disposal method for off-site soils and debris
within the Vertac OU2 ROD.
The major components of that amendment, which are selected
in this ROD, include the consolidation of soils to be excavated
from the Rocky Branch Creek flood plain within the on-site RCRA
Subtitle C landfill. Consistent with the 1990 Off-Site Areas
ROD, all soils with dioxin concentrations greater than or equal
to 1 ppb in the Rocky Branch Creek flood plain will still be
excavated. In addition, this ROD calls for the consolidation of
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removed sediments from the sewage collection lines within the on-
site RCRA Subtitle C landfill. Those sediments have been removed
and are currently stored on-site. Finally, this ROD calls for
the consolidation of removed digester sludges within the on-site
RCRA Subtitle C landfill. Those dioxin-contaminated sludges have
been removed from the abandoned sewage treatment plant sludge
digester and are currently stored on-site.
Underground On-Site Utility Lines. Building Foundations and
Curbed Areas
The final component of the remedy selected in this ROD
relates to on-site utility lines, building foundations, and
curbed areas. Under this remedy, the underground utility lines
will be cleaned to remove solids and filled with grout. Solids
from the lines will be consolidated within the on-site RCRA
Subtitle C landfill. Cutoff barri'-s wi"] '- installed .round
various underground utility lines to prevent shallow water
migration and contaminant transport, along the lines.
The remedy selected for the building foundations and curbed
areas consists of the cleaning through hydroblasting and
scarification, after which they will be left in place. Areas
with persistent staining will be sealed rfith epoxy type sealants.
Upon completion of the cleaning and scarification, the
foundations and curbed areas will be covered with soil adequate
to support a vegetative cover and contoured to prevent erosion
and ponding.
While the OU2 feasibility study (FS) identified five
underground storage tanks (USTs) suspected of containing
petroleum products, and both the original May 1995 Proposed Plan
for OU2 ana the March 1996 Supplemental Proposed Plan for OU2
discussed those five USTs, Hercules, Inc., has recently taken
action to address those tanks by draining their contents and
backfilling the tanks with "flowabj.<- grout containing a mixture
of cement, fly ash, and sand. Therefore, this ROD need not
address the tanks.
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. Because this remedy
involves on-site consolidation of low level threat media, it need
not satisfy treatment as a principal element of the remedy.
Instead, the remedy selected is consistent with the NCP's
preference for containment remedies when addressing low level
threat media. However, because this remedy will result in the
consolidation within a RCRA Subtitle C hazardous waste landfill
of contaminated soils, debris, and sludges, hazardous substances
will remain on a portion of the site above levels that allow for
unlimited use and unrestricted exposure. This is due to the fact
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that the hazardous waste landfill will remain in place for an
indefinite period of time, and due to the fact that the above-
described 1984 Court-ordered remedy resulted in dioxin wastes
remaining in place. Therefore, EPA shall review the remedial
action no less than every five years after initiation of the
selected remedial action to ensure that the remedy continues to
provide adequate protection of human health and the environment.
That five-year review is required by CERCLA Section 121(c), 42
U.S.C. S 9621(c).
SEP 1 71996
J>ne It. Sagina
Regional Adm
. 'v.PA Reg
or
Date
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TABLE OF CONTENTS
1.0 SITE LOCATION AND DESCRIPTION 1
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES 4
2.1 Site Operations History . . , 4
2.2 Enforcement Activities 6
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION 10
4.0 SCOPE AND ROLE OF OPERABLE UNIT 13
5.0 SUMMARY OF SITE CHARACTERISTICS 20
5.1 Demography and Land Use in the Area of the Site ... 20
5.2 Soils and Geology 22
5.2.1 Soils 22
5.2.2 Geology 22
5.3 Hydrology 25
5.3.1 Surface Water 25
5.3.2 Ground Water 25
5.4 Remedial Investigation Findings 26
5.4.1 Background 26
5.4.2 Sampling Results for Surface Soils 30
5.4.3 Subsurface Soils 36
5.4.4 Tetrachlorobenzene Spill Area 36
5.4.5 Underground Utilities 36
5.4.6 Underground Storage Tanks 37
5.4.7 Offsite Rocky Branch Creek and Bayou
Meto Flood Plain Soils 38
5.4.8 Residential Bagged Soils 38
5.4.9 Sludges and Sediments from Old Sewage
Treatment Plant Digester 38
6.0 SUMMARY OF SITE RISKS 39
6.1 Risk Assessment Description 39
6.2 Identification of Chemicals of Concern 40
6.3 Human Health Risk Assessment 46
6.3.1 Summary 46
6.3.2 Exposure Assessment 46
6.3.3 Toxicity Assessment 49
6.3.4 Risk Characterization 67
6.3.5 Uncertainty Analysis 72
6.3.6 Central Tendency Exposure 76
6.4 Ecological Risk Assessment 76
6.5 Remedial Action Goals 79
7.0 DESCRIPTION OF ALTERNATIVES 86
7.1 Alternatives 86
7.2 ARARs 104
7.2.1 Federal ARARs 107
7.2.2 State ARARs 124
7.2.3 To-Be-Considered 131
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8.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 132
8.1 Comparative Analysis of Remedial Alternatives 134
9 . 0 THE SELECTED REMEDY 141
9.1 Soils and Sediment Media 144
9.2 Underground Utilities and Tanks 146
10. STATUTORY DETERMINATIONS 147
10.1 Protection of Human Health and the Environment .... 147
10.2 Compliance with ARARs 149
10.3 Cost Effectiveness 150
10.4 Utilization of Permanent Solutions and
Alternative Treatment Technologies 151
10.5 Preference for Treatment 151
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES 152
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LIST OF FIGURES
Figure 1 Site Location Map 2
Figure 2 Vertac Site Map 3
Figure 3 Land Use Zoning Map 21
Figure 4 Geologic Map of Jacksonville Area 24
Figure 5 Remedial Actions Performed at the Site 27
Figure 6 Vertac Site Process Areas 28
Figure 7 Early Sampling Grids at Vertac 31
Figure 8 Sampling Grids in the Central Process Plant Area 32
Figure 9 Sampling Grids Outside Central Process Plant Area 33
Figure 10 Conceptual Model of Exposure Pathways 50
Figure 11 Conceptual Diagram of Soil Cover 92
Figure 12 Conceptual Model of Subtitle-C Landfill 93
Figure 13 Map Depicting Fenced (Restricted Access) Area of
the Site and Area where Access will be
Unrestricted 143
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LIST OF TABLES
1
2
3
4
5
6
7
Table
Table
Table
Table
Table
Table
Table
Table 8
Table 9
Table 10
Table 11
Table 12
Table 13
Table 14
Table 15
Table 16
Table 17
Table 18
Table 19
Table 20
Table 21
Table 22
Table 23
Table 24
Table 25
Table 26
Table 27
Table 28
Table 29
Table 30
General Geologic Section for Site 23
Site Contaminants of Concern 34
Contaminants of Concern in Soil 41
Contaminants of Concern in Ground Water 42
Contaminants of Concern in Surface Water 44
Soil Ingestion 51
Dermal Absorption 52
Soil Inhalation 54
Vapor Inhalation 56
Surface Water Dermal 57
Ground Water Ingestion ... 59
Model for Calculating Dose
Model for Calculating Dose
Model for Calculating Dose
Model for Calculating Dose
Model for Calculating Dose
Model for Calculating Dose
Categorization of Carcinogenic Substances 61
Cancer Slope Factors 62
Chronic Reference Doses 63
Subchronic Reference Doses 65
Potential Lifetime Cancer Risk - Trespasser 69
Potential Lifetime Cancer Risk - Current Worker 70
Potential Lifetime Cancer Risk - Future Worker 71
Hazard Quotient/Index - Trespasser 73
Hazard Quotient/Index - Current Worker 74
Hazard Quotient/Index - Future Worker 75
Central Tendency - Cancer Risk/Hazard Indices 77
Parameters Used in RME Risk Calculations 82
Parameters Used in Monte Carlo Risk Calculations 83
Comparison of RME and Monte Carlo Risk Calculations ... 85
Remediation Goals for Contaminated Soils 86
Summary of Soils Alternatives 88
Quantities of Materials for Soils Alternatives 89
Summary of Underground Utilities Alternatives 102
Potential ARARs for the Vertac Site 106
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LIST OF ATTACHMENTS
Attachment A - [Foreword] Original Responsiveness Summary
Attachment B - Supplemental Responsiveness Summary
Attachment C - Arkansas Department of Pollution Control
and Ecology Letter
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DECISION SUMMARY
FOR THE
VERTAC SUPERFUND SITE
JACKSONVILLE, ARKANSAS
OPERABLE UNIT #2
SEPTEMBER 1996
1.0 SITE LOCATION AND DESCRIPTION
The Vertac Incorporated Superfund Site (the site) is
approximately 193 acres in size, and is located on Marshall Road
in Jacksonville, Pulaski County, Arkansas, as shown in Figura 1.
Jacksonville is about 15 miles northwest of the State Capital,
Little Rock. Approximately 1,000 residents live within one mile
of the site with residential areas bordering the entire east and
south sides. The west and northern sides of the site are bounded
by an industrial area and the Little Rock Air Force Base,
respectively.
The site consists of two parcels of land (Parcel 1 and
Parcel 2) that were acquired at different times during plant
operations (Figur* 2). Parcel 1 (the southern acreage), which
contains the central process area, is approximately 93 acres and
has been in nearly continuous industrial use since 1948. Parcel
2, which is approximately 100 additional acres to the north, was
purchased by Vertac Chemical Corporation (Vertac) in 1978 but was
never used in the herbicides formulations operation. In 1979,
the 2,4,5-T storage shed was built adjacent to the Regina paint
building, which today is believed to contain empty Vertac 2,4,5-T
waste drums Parcel 2 does not contain production facilities and
is currently used by the United States Environmental Protection
Agency (EPA) for drum storage in newly-constructed warehouse
buildings. An incinerator constructed under the contract to the
Arkansas Department of Pollution Control and Ecology (ADPC&E) to
burn drummed waste is also located in the northern part of
Parcel 1.
Topographically, the land has moderate relief, sloping from
about 310 feet above mean sea level (MSL) in the north to
approximately 260 feet near the southwestern corner. The central
process area is located on a south plunging topographic nose
bounded by Rocky Branch Creek on the west and Marshall Road on
the east. Land on the western side of Rocky Branch Creek has not
been used for manufacturing or disposal and is topographically
separated from the central process plant area by the creek. Land
on the eastern side of Marshall Road has not been used for
manufacturing and is geographically separated from the central
process plant area by Marshall Road. Land on the northern part
of the site has not been used for herbicide manufacture and is
generally up slope from the central process plant area.
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JACKSONVILLE
/
SITE
LOCATION
Source: U.S. Geological Survey
7.5 Minute Series
Otmstead, AR (1967)
Cabot, AR (1987)
Jacksonville, AR (1987)
McAlmont, AR (1986)
1248-331 11/16/92
QUADRANGLE LOCATION
SITE LOCATION MAP, VERTAC SITE
JACKSONVILLE, ARKANSAS
FIGURE 1
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r~* vW^ ->^ Containerize
i Change V*^Ł^ Soil Storage
House __y Warehouse
Storagd /TjT™"*^ HU Laboratorv
Building// eussand '/I Chemica,
:=:,. XV instrument Shop >VStorage_
===:=:=:=::=5Supervisorh
•Storeroom ' offices
Legend
Boundary Between
Parcels 1 and 2
•"•""•• Central Process Area
•"• e» ••§ Property Line
»• Rocky Branch Creak
Y///////A Buildings and Foundations
niiiirl Railroad
—»— Fence
600
Revised February 1993
SITE MAP, VEHTAC SITE
JACKSONVILLE, ARKANSAS
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2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.1 SITE OPERATIONS HISTORY
The first facilities on the site were constructed by the
U.S. Government in the 1930's and 1940's. These facilities were
part of a munitions complex that extended beyond the present site
boundaries. Little is known about the operations that occurred
during that time period. In 1948, the Reasor-Hill Company
purchased the property and converted the operations to
manufacture insecticides such as DDT, aldrin, dieldrin, and
uoxaphene. During the 1950's, Reasor-Hill manufactured
herbicides such as 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,5-
trichlorophenoxyacetic acid (2,4,5,-T), and 2,4,5-
trichlorophenoxypropionic acid (2,4,5,-TP), which is also called
Silvex. Drums of organic material were stacked in an open field
immediately southwest of the production area, and untreated
process water was discharged from the western end of the plant to
Rocky Branch Creek.
Hercules Powder Company, now known as Hercules, Inc.
(Hercules), purchased the Reasor-Hill property and plant in 1961
and continued to manufacture and formulate herbicides. The drums
that were in the open area southwest of the central process area
were buried in what is now referred to as the Reasor-Hill
Landfill. From 1964 to 1968, Hercules produced the herbicide
Agent Orange, a mixture of equal parts of 2,4,5-
trichlorophenoxyacetic acid (2,4,5-T) and 2,4-
dichlorophenoxyacetic acid (2,4-D). Hercules discontinued
operations at the site in 1971.
From 1971 to 1976, Hercules leased the plant site to
Transv?-*! , Inc. (Transvaal), a predecessor company of Vertac.
Transvaal resumed production of 2,4-D and intermittently produced
2,4,5-T. Organic wastes from these manufacturing processes were
stored and then buried by Hercules on the site in what is now
referred to as the North Landfill area. Transvaal purchased the
property and plant from Hercules in 1976. In 1978, Transvaal
underwent a Chapter XI bankruptcy reorganization and ownership of
the site was transferred to the new company, Vertac Chemical
Corporation, which is the present owner.
In 1979, ADPC&E issued an order that required Vertac to
improve its hazardous waste practices, and in 1980 EPA and ADPC&E
jointly filed suit in federal district court against Vertac and
Hercules. A Consent Decree entered into by EPA, ADPC&E, Vertac,
and Hercules in January 1982 required that an independent
consultant assess the conditions of pnsite wastes and develop a
proposed disposal method for the wastes. The proposal, called
the "Vertac Remedy", was deemed by EPA to be unsatisfactory. The
court decided in favor of the proposed remedy, which was
implemented in the summer of 1984 and completed in July 1986. As
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part of the remedy, the Vertac plant cooling water pond was
closed, and sediment from this unit was removed and placed in an
above-ground vault. The Reasor-Hill and Hercules/Transvaal
Landfills were capped, and a French drain and leachate collection
system were installed around the burial (landfill) areas. Ground
water monitoring wells were also installed, and a ground water
monitoring program was initiated.
Vertac operated the plant until 1986. On January 31, 1987,
Vertac abandoned the site and declared bankruptcy, leaving
approximately 29,000 drums of 2,4-D and 2,4,5-T wastes. Many of
these drums were corroded and leakj.nt,. At tl*at time EPA
initiated an emergency removal action to stabilize and secure the
site.
In 1988, ADPC&E contracted for the incineration of the
drummed waste, using a $10.7 million combined trust fund and
letter of credit obtained from Vertac during bankruptcy
litigation. A contract for the incineration of the drummed waste
was signed in 1989 between ADPC&E and Vertac Site Contractors
(VSC). VSC is a joint venture of MRK Incineration and Morrison-
Knudsen Environmental Services. In January 1992, ADPC&E approved
the VSC trial burn and production incineration began. Because of
the difficulty in handling the Vertac drummed waste material,
incineration operations took longer than originally anticipated.
In May 1993, the trust fund money had been expended with
approximately 50 percent of the waste destroyed under the State's
contract. In June 1993, EPA took over the incineration operation
and completed the incineration of the D-waste drums in September
1994. EPA contracted for the off-site incineration of the
remaining 3,100 drums of T-waste. Shipments of T-waste to the
APTUS commercial hazardous waste incineration facility, located
in Coffeyv:"le, Kansas, concluded on March 29, 1996.
On July 16, 1996, the Regional Administrator for EPA Region
6 executed a Non-Time Critical Removal Action Memorandum that
concluded the on-site incinerator support activities associated
with the on-site D-waste incineration, which had concluded on
January 2, 1994. That Action Memorandum authorized the off-site
disposal of 33,000 drums of salts (and the associated pallets)
that were generated during the on-site incineration of D-wastes,
and it authorized the on-site disposal within the RCRA Subtitle C
hazardous waste landfill of both 10,000 shredded pallets used to
store drummed waste materials and of 6,300 drums of incinerator
ash (and their associated pallets). In that Action Memorandum,
the Regional Administrator also granted a variance from the RCRA
Land Disposal Restriction (LDR) treatment standard applicable to
dioxin-containing wastes found at 40 CFR S 268.31. Specifically,
the Regional Administrator approved a treatability variance for
the disposal of dioxin-contaminated wastes within the on-site
RCRA Subtitle C landfill of 5 ppb from the LDR standard of 1 ppb
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pursuant to the procedures set out at 40 CFR S 268.44.
Therefore, should the LDR dioxin treatment standard be
applicable to the on-site disposal within the on-site RCRA
Subtitle C hazardous waste landfill if placement within the unit
occurs, the treatment standard is 5 ppb. See July 18, 1996, Non-
Time Critical Action Memorandum in Administrative Record for more
details.
Currently, there are no manufacturing operations at the
site. At the time operations were shut down, Vertac "mothballed"
the plant. Mothballing involved flushing process lines and
draining several of the process vessels. Continuing activities
at the site include operation of an on-site wastewater treatment
plant by Hercules, Inc. The treatment plant processes ground
water collected in French drains constructed downgradient (south
and west) of the old waste burial areas, and surface water runoff
collected in a series of drainage ditches and sumps that surround
the central process area. This treated water was originally
piped to the West Wastewater Treatment Plant owned and operated
by the city of Jacksonville and was discharged into Bayou Meto.
As part of ongoing remedial activities at the site, Hercules has
recently completed the cleaning and regrouting of certain
sections of the sewer lines that run through the site to the West
Wastewater Treatment Plant, and as such, water that was
discharged to the sewer interceptor on the site is now treated
and discharged directly into Rocky Branch Creek (after meeting
discharge limits established by ADPC&E).
The Vertac site was added to the National Priorities List
(NPL) of hazardous waste sites in 1982. Once the site was placed
on the NPL, money available from the Comprehensive Environmental
Response, Compensation, and Liability Act of 1980, commonly
called Superfund, 42 U.S.C. § 9601 et seq.. could be used to
investigate and study the problems at the Vertac site and find
ways to correct them to protect the public health and the
environment.
2.2 ENFORCEMENT ACTIVITIES
A Potentially Responsible Party (PRP) search was not
conducted since the Agency knew the identities of former owners,
operators, and some generators of waste at the Vertac site, and
since litigation was already ongoing prior to CERCLA activities.
However, CERCLA Section 104(e) information request letters were
mailed in March 1990, and later to several companies which had
"tolling agreements'* with the Vertac Chemical Corporation and/or
Hercules.
The following is a chronology of enforcement activity at the
Vertac site:
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1. Litigation was filed in 1980 under Section 7003 of the
Resource Conservation and Recovery Act (RCRA), 42 U.S.C. §
6973, and other statutes by the United States and the State
of Arkansas against Vertac Chemical Corporation and Hercules
Inc. (the Parties). In January 1982 EPA and the State of
Arkansas entered into a Consent Decree with Vertac Chemical
Corp. and Hercules, Inc., in the litigation for developing a
remedial plan for certain on-site and off-site areas. After
EPA invoked dispute resolution and had a hearing on the
remedy, the Court ordered the implementation of the "Vertac
Remedy" in July 1984 (see Site History for a discussion of
the action taken).
2. In July 1986, pursuant to an agreement between the parties
and entry by the court, Vertac established an Environmental
Trust Fund as part of a bankruptcy agreement. Vertac placed
$6,700,000 in this fund to be used to remediate portions of
the plant. A $4,000,000 letter of credit was later added to
this Trust Fund also for the purpose of future site
remediation. Both EPA and the State of Arkansas had access
to this fund which was later used to incinerate the 29,000
drums of waste left at the site by Vertac.
3. In August 1986 EPA issued a Unilateral Administrative Order
(UAO) pursuant to Sections 104 and 106 of CERCLA, 42 U.S.C.
SS 9604 and 9606, to all PRP's to require posting of warning
signs and the fencing of portions of the West Wastevattr
Treatment Plant and certain areas of Rocky Branch Creek.
This work was performed by Hercules.
4. In January 1987 EPA issued a notice letter to Vertac
Chemical Corp. that required Vertac Chemical Corp. to
continue operation and maintenance of the leachate
collection and treatment system which was established around
old on-site waste burial areas.
5. In June 1938 EPA signed an Administrative Order on Consent
(AOC) pursuant to Section 106 of CERCLA, 42 U.S.C. S 9606,
with Hercules to allow Hercules to implement the fine grid
sampling investigation for specific off-site areas.
6. In September 1988 EPA signed an AOC pursuant to Section 106
of CERCLA, 42 U.S.C. S 9606, with Hercules that required
Hercules to remove approximately 3,000 cubic yards of
dioxin-contaminated soil from residential yards near the
facility.
7. In July 1989 EPA signed an AOC pursuant to Section 106 of
CERCLA, 42 U.S.C. S 9606, with Hercules that required
Hercules to conduct the on-site Remedial
Investigation/Feasibility Study (RI/FS).
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8. In March 1990 EPA sent CERCLA Section 104(e) information
request letters to several companies which had been involved
in business deals with the Vertac Chemical Corp. and
Hercules Inc., including "tolling agreements".
9. In July 1990 EPA sent General Notice letters to the PRP's
regarding the proposed off-site remedial plan and other site
actions.
10. In February 1991 the U.S. District Court for the Eastern
District of Arkansas entered a Consent Decree between the
United States and "Phoenix Parties", which are companies
related to the Vertac Chemical Corp., and which carried on
the remaining business of Vertac under their names after
Vertac abandoned the site. Hercules appealed the entry of
the Consent Decree to the Eighth Circuit Court of Appeals,
which upheld the entry of the Consent Decree in April 1992.
Under the terms of the Consent Decree, the Phoenix Parties
have contributed $1,840,000 to a RCRA Closure Trust Fund,
and will contribute a percentage of pre-tax profits for 12
years, in return for release of liability.
11. Hercules, Inc., had opposed the United States' efforts to
select various CERCLA remedies at Vertac. This opposition
included a motion filed in September 1992 to enforce the
1982 RCRA Consent Decree. The parties were ultimately
unable to resolve their differences regarding this motion.
In June 1992 the District Court entered an order denying
Hercules' motion to enforce the Consent Decree and allowed
EPA to utilize CERCLA procedures to select remedies for the
Vertac site.
12. The United States added CERCLA Section 107, 42 U.S.C. §
S»ou7, cost recovery claims against Hercules, Dow Chemical
Company, and Uniroyal Chemical Limited of Canada, in a
complaint filed in March, 1992. By order of the trial court
in June 1992, this complaint was administratively closed,
and the claims asserted against Hercules, Dow, and Uniroyal
were consolidated with the existing litigation. Other
parties, including BASF AG, Standard Chlorine, and Velsicol,
have been added to the litigation as third-party defendants.
13. Special notice letters for Remedial Design/Remedial Action
(RD/RA) for the off-site areas were sent to the PRP's in
August 1992. No "good faith" offers were received in
response to the letter. A subsequent special notice letter
was sent in December 1992 to the PRP's after EPA revised the
scope of the remedial work at the off-site areas.
Negotiations regarding this work did not result in an RD/RA
Consent Decree.
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14. In June 1993 EPA issued a Unilateral Administrative Order
(UAO) pursuant to Section 106 of CERCLA, 42 U.S.C. S 9606,
to Hercules requiring it to implement the Remedial Design
and Remedial Action for the Off-site ROD, which was signed
in September of 1990.
15. In March 1994 EPA issued another UAO pursuant to Section 106
of CERCLA, 42 U.S.C. S 9606, to Hercules requiring it to
implement the Remedial Design and Remedial Action for the
Operable Unit 1 ROD, which was signed in June of 1993.
16. The liability phase of the on-going -itigation was completed
in October 1994, when the United States was granted a motion
for summary judgement against Hercules, Inc., holding it
jointly and severally liable to the United States for past
and future response costs incurred at the site. The claims
made by the United States were against Hercules, Inc., Dow
Chemical Company, and Uniroyal ^nder CERCLA Section 107, 42
U.S.C. S 9607, for recovery of costs related to the Vertac
site, including EPA removal costs. The claims against Dow
and Uniroyal were based on tolling agreements that those
companies had with Vertac, where they sent raw materials to
Vertac for processing into finished product that was shipped
back to them. These tolling agreements constituted
arrangements for disposal pursuant to CERCLA Section
107(a)(3), 42 U.S.C. S 9607(a)(3). Prior to a liability
phase trial, the United States settled its claims against
Dow through a Consent Decree for $3.5 million. Settlements
were also reached with Velsicol and the United States on
behalf of the Department of Defense.
The only United States claims remaining unresolved after
these ~,ettlements were those against Uniroyal. The
liability phase of the trial against Uniroyal was concluded
in November 1993. A jury, sitting both as an advisory jury
and a fact-finding jury, returned a verdict finding Uniroyal
also liable at the site for CERCLA Section 107 costs, but
that its involvement was divisible. To date, the Court has
not entered its order addressing the findings of the jury,
and the cost phase of the trial has not been initiated.
17. Although not specifically enforcement related, several
separate citizens suits were filed seeking to halt
incineration of the 29,000 drums of dio:cin contaminated
still bottom wastes which were stored at the site. They are
as follows:
After the incineration contract was finalized, but before
the first trial burn, came National Toxics Campaign (NTC).
et.al. v. Arkansas Department of Pollution Control and
Ecology (ADPC&E). et. al.. seeking to enjoin the impending
trial burn. After six days of testimony, the trial court
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denied a preliminary injunction based on the merits. NTC
subsequently dismissed its lawsuit in federal court.
Incineration opponents sued again, in State chancery court,
on the morning of the same trial burn approved in federal
court during the NTC litigation. This suit, Rubv Brown and
Sharon Golqan v. ADPC&E. was filed in Pulaski County
Chancery Court. The chancellor denied the temporary
restraining order on the merits after a hearing that day.
After thousands of D-waste drums had been burned, ADPC&E's
director announced that T-waj^e would b_ burned after a
limited burn of T-waste so that ambient air and incinerator
stack data could be evaluated for risk considerations. This
announcement brought the lawsuit by the Arkansas Peace
Center (APC) gt aj^, in October 1992. During this
litigation, control of the incineration passed from State to
EPA control, after State funds were exhausted.
The APC litigation resulted in a preliminary injunction (the
March 17, 1993, order mentioned above), a subsequent stay of
that injunction by the Eighth Circuit based on both
jurisdiction and the merits, and eventual dismissal due to
lack of jurisdiction.
After denial of a petition for certiorari to the U.S.
Supreme Court, plaintiffs filed suit again in chancery court
in April 1994. That case was removed to federal court and
eventually dismissed. In the dismissal order, the district
court found that the lawsuit was barred by CERCLA 113(h), 42
U.S.C. S 9613(h), since the lawsuit was clearly designed to
stop incineration. The District Court also found that
dismissal was appropriate based on res judicata. i.e.. that
the same case had already been tried.
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
A community relations plan for the Vertac site was put in
place in 1983. This plan listed contacts and interested parties
within the federal, state, and local governments, various
organized affiliations, and local citizens. It also established
communication pathways to ensure timely dissemination of
pertinent information about site activities. Extensive community
outreach has been performed in Jacksonville over the years
through the release of information fact sheets, by conducting
frequent open houses and work shops, and through numerous
meetings with local civic groups and media representatives
(newspapers, radio and TV). Reports updating activities at the
site are also distributed to the Mayor, interested civic groups,
and the local media on a weekly basis. A satellite community
relations office was established in Jacksonville in July 1990 to
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provide easy access to documents and information, and to provide
a local contact for questions and concerns.
A Technical Assistance Grant (TAG) was awarded by EPA in
1989 to a citizens group called Jacksonville People With Pride
Clean Up Coalition (JPWPCUC). This award was challenged by
citizen groups that had competed for the grant and who alleged
that JPWPCUC was funded by the Potentially Responsible Parties
(PRP's) for Vertac. Upon investigation by EPA, the grant was
annulled after it was determined that the JPWPCUC TAG application
listed their source of matching funds as a bank account shared
with their larger "parent" group, che Jacksonville People With
Pride. This parent group had indeed accepted monetary
contributions from Vertac PRP's, and since these funds were not
distinct from those of JPWPCUC, EPA determined that a possible
conflict of interest could exist, resulting in annulment of the
TAG in December 1991.
TAG availability was again advertised in January 1992, and
the grant was awarded to the Concerned Citizens Coalition (CCC)
in April 1993 after considerable effort by EPA to facilitate
consolidation of four competing citizen groups. CCC then
solicited several technical groups in order to select a technical
advisor for the TAG. The Environmental Compliance Organization
(ECO) was selected as the technical advisor and actively reviewed
site documents for the community.
In February 1995 EPA released the draft feasibility study
(FS) for Operable Unit 2, and several meetings were held in
Jacksonville with local citizens groups and the press to discuss
the various options being considered. The Operable Unit 2 FS was
finalized in April 1995, and was made available to the public at
five local repositories (Jacksonville City Hall, Public Library,
Police Courts Building, Air Force Base Library, and ADPC&E). The
official Administrative Record for this Operable Unit is
maintrined at EPA in Dallas, the Jacksonville City Hall, and the
Arkansas Department of Pollution Control and Ecology in Little
Rock.
In the feasibility study, EPA assumed that the future land
use for the site, based on past land use and existing zoning
ordinances, would be commercial/industrial. This reasonably
anticipated future use for this site is consistent with EPA's
directive "Land Use in the CERCLA Remedy Selection Process,"
OSWER Directive No. 9355.7-04, May 25, 1995.
On May 25, 1995, EPA held an informal open house in
Jacksonville to discuss EPA's proposed plan of action for
contaminated soils at the Vertac site. The meeting was well
attended by Jacksonville citizens, members of the city
government, State Health Department representatives, numerous
local civic groups, and the technical advisor for the TAG grant.
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At that time, the proposed plan was released to the public for
review and comment. Several weeks prior to the informal open
house, the EPA project manager met with the local press to
discuss the major elements of EPA's proposed plan which received
coverage in both local papers and the State paper. At this open
house, EPA discussed with the community the anticipated future
land use scenario for the site, which formed the basis for EPA's
risk assumption. That risk assumption presupposed that the
future usage of the site would remain consistent with both past
land use and current zoning for the site area, which is
commercial/industrial. Therefore, the EPA derived the site's
cleanup level of 5 parts per billion (ppb) toxicity equivalents
(TEQ) for dioxin due to the fact that a commercial/industrial
human exposure scenario assumes that a worker would be exposed to
post-cleanup dioxin levels over a 40-hour-per-week period. This
worker exposure scenario additionally is protective of a
trespasser or a passerby, both of whose exposure period would be
less than that ox a site worker.
On June 15, 1995, EPA held a formal public meeting in
Jacksonville at the community civic center to discuss EPA's
proposed cleanup scenario for dioxin-contaminated soils at the
Vertac site. At that meeting EPA attempted to address all
comments or questions raised concerning the proposed cleanup and
formally accepted all public comments. Over 100 citizens
attended the meeting, including members from the Jacksonville
Chamber of Commerce, Jacksonville City Council, the Mayor,
representatives from ADPC&E, and the State Health Department.
The comment period for the proposal ran from May 26 through
August 11, 1995, after EPA granted two extensions of time. All
comments received by EPA prior to the end of the public comment
period, including those expressed verbally at the public meeting,
are addressed in the Responsiveness Summary section of this
Recorv- >,f Decision. Thus, the requirements of CERCLA Sections
113(k) (2) (B) (i-v) and 117, 42 U.S.C. SS 9613(k) (2) (B) (i-v) and
9617, were met during the remedy selection process. During both
the May open house and the June public meeting, the community
indicated its approval and acceptance of EPA's reasonably
anticipated land use for the site and the risk assumptions based
on that anticipated future land use.
EPA's original proposal for remediation of soils,
foundations and underground utilities at Vertac was presented to
the community at an informal open house held in Jacksonville on
May 25, 1995. At that time EPA's preferred alternative called
for the off-site incineration of dioxin-contaminated hot spots
and on-site landfilling of dioxin contaminated soils that
exceeded a site-specific commercial/industrial exposure level.
Under this scenario approximately two-thirds of the site would
have potentially been available for future commercial reuse.
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Following the release of the original Proposed Plan for OU2
in May 1995 and the subsequent community meetings, EPA
Administrator Carol M. Browner issued a series of administrative
reforms for the Superfund Program on October 3, 1995. One
purpose of the reforms was to control remedy costs and to promote
cost effectiveness, and the reforms directed EPA to base site
cleanup decisions on practical future land usage and reasonable
contaminant exposure scenarios.
As a result of those reform measures, and due to the ongoing
deadlock over the Federal budget, occurring at the time, Region 6
revised the proposed plan of action for OU2. The Supplemental
Proposed Plan was issued on February 26, 1996, and presented to
the public at an Open House on March 5, 1996. The Supplemental
Proposed Plan for OU2 eliminated the off-site incineration
component of the original proposed plan, included capping in-
place soils having dioxin contamination between 5 to 50 ppb, and
proposed on-site landfilling of soil contaminated with dioxin in
excess of 50 ppb. The community objected strongly to the
Supplemental Proposed Plan.
After the March 5, 1996, Open House, EPA representatives
conducted numerous meetings with several community groups to
listen to the concerns of the local residents. Following the
March 5, 1996, release of EPA's Supplemental Proposed Plan for
OU2, EPA held another comment period to accept formal public
comment on the supplemental plan. The response to these comments
is contained separately from the original responsiveness summary
in the "Supplemental Responsiveness Summary,1* which is included
as Attachment B to this document. Subsequently, EPA conducted
another open house on July 30, 1996, to present to the public the
remedial elements it had reconsidered and currently held under
consideration at the time. In general, EPA has responded to
community concerns and has reevaluated the OU2 FS and the two
proposed plans, and the elements discussed during the July 30,
1996, Open House are now contained in this ROD.
4.0 SCOPE MID ROLE OF OPERABLE PHIT
The problems at the Vertac Superfund site are complex, and
the EPA has determined that site remediation can be accomplished
most efficiently in six phases. This ROD addresses one of the
six cleanup phases, i.e.. Operable Unit 2, which consists of on-
site soils, off-site soils and sediments, underground utility
lines, building and equipment foundations, curbs, and pads.
The studies undertaken at the Vertac Superfund site for
Operable Unit 2 media have identified the soils at the site to be
a low-level threat in light of all the media being remediated at
the site. EPA has made that determination with respect to the
site soils and associated debris, which includes contaminated
media having similar dioxin contamination levels. Those media
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include treatment residues from the on-site incineration of D-
waste, dioxin-contaminated drums, containers, pallets, personal
protective clothing and equipment, process equipment and
structures, and sludges and sediments associated with historical
treatment of wastewaters. EPA has defined these media as
constituting low-level threats in contrast to principal threats.
Generally, EPA associates principal threats with liquids,
areas contaminated with high concentrations of toxic compounds,
and highly mobile materials that generally cannot be reliably
contained. See NCP Section 300.430(a)(iii)(A), 40 CFR S
300.430(a)(iii)(A). Low-level threat wa~_es are those source
materials that can be reliably contained and that would pose only
a low risk in the event of a release. Wastes that generally are
considered to constitute a low-level threat include surface soils
containing contaminants of concern that are relatively immobile
in air or ground water, i.e.. non-liquid, low volatility, and low
leachability. See "A Guide to Principal Threat and Low Level
Threat Wastes," November 1991, OSWER Directive No. 9380.3-06FS.
That guidance document states where toxicity and mobility of
source material combine to pr^e a potential risk of 10~3 (1 in
1,000 excess cancer deaths) or greater, treatment alternatives
generally should be evaluated. In addition, NCP Section
300.430(a)(iii)(B), 40 CFR S 300.430(a)(iii)(B), in
characterizing EPA's remedial program expectations, states:
EPA expects to use engineering controls, such as
containment, for waste that poses a relatively
low long-term threat or where treatment is
impracticable.
Therefore, on-site consolidation within a RCRA Subtitle C
hazardous waste landfill is appropriate for these low level
threat dioxin-contaminated media because EPA's threat guidance
would only direct EPA to consider other treatment alternatives
where those media would constitute a principal threat. Such a
determination would only arise when the overall dioxin
concentration would exceed 5,000 ppb (three orders of magnitude
above the 5 ppb dioxin cleanup level identified in its site-
specific risk assessment as protective for commercial/industrial
exposures).
The concentrations of dioxin present in Vertac soils are
generally an order of magnitude lower than the concentrations
found in the dioxin-containing liquids (both drummed still bottom
wastes and process tank sludges), and as such, are identified as
a low-level threat based on relative concentration to other site
media. The dioxin in the Vertac soils also fit the definition of
a low-level threat due to the fact that they are relatively
immobile except through sediment transport, i.e.. soil migration
from rainwater runoff. Dioxins are characterized as having a
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very low solubility in water and a very low vapor pressure (they
do not readily leach to ground water or vaporize to the air). In
addition, numerous studies have also shown that dioxin binds
tightly to fine-grained and organic-rich soils, further reducing
its mobility.
Dioxin, however, is considered to be a highly toxic
compound, and if left unremediated would continue to present a
serious threat to the public health and the environment due to
the potential for cancer and noncancer effects, and would also
continue to present potential long term threats to the
environment from the migration of contaminants off-site through
various sediment transport mechanisms.
Remedial action objectives have been developed to address
the compounds of concern at this site, namely, 2,3,7,8-
tetrachlorodibenzo-p-dioxin (TCDD or dioxin) and other dioxin and
furan congeners, chlorobenzene, chlorophenoxyherbicides,
chlorophenols, and toluene. The remedial action objectives are
formulated in such a way that residual contaminant concentrations
in the media of concern are reduced or controlled to a level
where exposure of an environmental receptor to the contaminants
does not result in an unacceptable carcinogenic risk or an
adverse toxic response when considering the reasonably
anticipated land use intended for the site. EPA's risk
assumption for OU2 presupposed that the future usage of the site
would remain consistent with past land use and the current zoning
for the site area, which is commercial/industrial. Therefore,
the EPA derived the site's cleanup level of 5 parts per billion
(ppb) toxicity equivalents (TEQ) for dioxin due to the fact that
a commercial/industrial human exposure scenario assumes that a
worker would be exposed to post-cleanup dioxin levels over a 40-
hour-per-week period. This worker exposure scenario additionally
is protective of a trespasser or a passerby, both of whose
exposure period would be less than that of a site worker.
The remedial action objectives, developed to address the
low-level threats present at the site, which are applicable to
the OU2 media are as follows:
• Prevent exposure of future site workers to concentrations of
site contaminants in surface soils that remain following
remedial activities which would result in an excess lifetime
cancer risk greater than 1 in 10,000 to 1 in a 1,000,000.
• Complete the soils remedial action activities to result in
average dioxin concentrations no greater than 1 ppb.
• Prevent exposure of future site workers to concentrations of
site contaminants that would result in an adverse toxic
response.
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• Prevent off-site environmental receptors from exposure to
site contaminants that would result in an adverse toxic
response.
• Prevent/control dust generation during remedial activities
and/or removal activities to the maximum extent practicable.
• In concert with OU3 (ground water) remedial activities,
prevent potential contamination of the on-site and off-site
ground water by releases from below-ground portions of the
plant, and
• Destroy and/or contain hazardous substances generated by the
remediation.
Following is a description of the six cleanup phases or
operable units that are currently in progress, or have been
completed at the Vertac site. Collectively, the completion of
all six phases is intended to address all environmental risks
posed by the site.
Phase 1 The "VERTAC REMEDY"
ADPC&E issued an order in 1979 that required Vertac, Inc.,
to improve its hazardous waste practices, and in 1980 EPA and
ADPC&E jointly filed suit in federal district court against
Vertac, Inc., and Hercules, Inc. A Consent Decree entered into
by EPA, ADPC&E, Vertac, and Hercules in January 1982 required an
independent consultant to assess the conditions of on-site wastes
and to develop a proposed disposal method for the wastes. The
proposal, called the "Vertac Remedy", was deemed by EPA to be
unsatisfactory and EPA returned to court in early 1984 for a
resolution. The court decided in favor of the proposed remedy,
which was implemented in the summer of 1984 and completed in July
1986.
As part of the remedy, the Vertac plant cooling water pond
and the equalization basin were closed and sediments from these
units were removed and placed into an excavated area where
earlier operators had buried drums of waste. The burial area was
capped and a French drain and leachate collection system were
installed around the burial areas. Ground water monitoring wells
were also installed and a ground water monitoring program was
initiated.
Phase 2 DRUMMED WASTE INCINERATION
In 1989, ADPC&E signed a contract to have approximately
29,000 barrels of 2,4-D and 2,4,5-T herbicide still bottom wastes
incinerated on-site. Wastes from the production of 2,4,5-T at
this site have been found to contain up to 50 ppm of dioxin,
while wastes from the production of 2,4-D generally contain
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dioxin in the low parts per billion range. All drummed wastes
are treated as F-listed (dioxin containing) wastes pursuant to
the Resource Conservation and Recovery Act (RCRA), 42 U.S.C. §
6901 et seq.
To accomplish this incineration, the State used funds from
the trust fund that was established when Vertac went bankrupt.
Incineration of these wastes began in fall 1990. In June 1993,
funding for the project was depleted and EPA assumed immediate
responsibility for incinerating the remaining drums as a time-
critical removal action undertaken pursuant to CERCLA Section
104, 42 U.S.C. S 9604. In late September 1994, the incineration
of 25,179 drums of dioxin-contaminated 2,4-D waste was completed
at the Vertac site. In July 1995 EPA announced that it would
pursue the off-site incineration of approximately 3,200 drums of
dioxin containing 2,4,5-T waste located at the Vertac site. On
November 9, 1994, a contract was signed between the APTUS
commercial incineration facility in Coffeyville, Kansas, and
EPA's prime contractor URS Consultants, to accept the Vertac
drummed T-waste material. The first shipment of T-waste went to
APTUS in November 1994, and the last shipment was sent off-site
on March 29, 1996.
Phase 3 VERTAC OFF-SITE AREAS
A Record of Decision (ROD) was signed in September 1990 to
address the cleanup of contiguous off-site areas that were
contaminated as a result of untreated and partially treated
surface and underground discharges of plant wastewater and other
releases. Elements of this operable unit include an active sewer
interceptor and an abandoned sewer interceptor, portions of an
old abandoned trickling filter wastewater treatment plant, an
active Wes+ Wastewater Treatment Plant, ind the Rocky Branch
Creek flood plain. The selected remedy called for removing
sediments from the active sewer interceptor, installing pipe
linern in the clean sewer, filling the abandoned interceptor with
grout, and removing sludge from the sludge digester in the old
wastewater treatment plant. Sludge drying beds in the old
wastewater treatment plant were capped with one foot of clean
soil and the aeration basin in the old wastewater treatment plant
was drained and demolished. Flood plain soils along Rocky Branch
Creek that are Contaminated with dioxin in excess of one part per
billion (ppb) will be excavated for treatment at Vertac.
Monitoring of fish in Rocky Branch Creek and Bayou Meto for
dioxin will continue.
As EPA proceeded with overall site remediation, it concluded
that it was appropriate to defer the disposal of the contaminated
soil and debris addressed in the 1990 Off-Site Areas ROD to make
the disposal of excavated off-site soils and debris consistent
with the disposal of on-site soils and debris. All other
elements of the off-site remedial action, except for the above-
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mentioned off-site soils and debris disposal and the excavation
of flood plain soils were completed in November 1995.
Hercules has completed the remedial design and has started
the remedial action under the terms of a Unilateral
Administrative Order issued in July 1993. The Order requires
Hercules to conduct the remedial design and remedial action to
implement the selected remedy, except the on-site incineration of
soils excavated from the Rocky Branch Creek flood plain and
contaminated sludges and debris from sewage treatment plant and
sediments from the interceptor lines was deferred to make the
disposal of excavated off-site soils consistent with the disposal
of on-site soils. All off-site remedial actions (except for the
excavation of flood plain soils) were completed in November 1995.
The excavation of the flood plain soils is expected to be
completed in early 1997.
Phase 4 ON-SITE ABOVE GROUND MEDIA (Operable Unit #1)
A ROD for the above ground media was signed in June 1993.
The above ground media includ« buildings, process equipment,
leftover chemicals in the process vessels, spent activated
carbon, shredded trash and pallets, and miscellaneous drummed
wastes at the site. The selected remedy consisted of: (1) On-
site incineration of F-listed process vessel contents, spent
carbon, shredded trash and pallets, and miscellaneous drummed
wastes; (2) off-site incineration of PCB transformer oils and
non- F-listed process vessel contents; (3) recycle/reuse of
decontaminated process equipment to the maximum extent
practicable; (4) on-site consolidation of debris resulting from
demolition of buildings and equipment that cannot be
recycled/reused in a RCRA subtitle C landfill; (5) the deferral
of a decision on the treatment of approximately 2,770 cubic yards
of TCDD-contaminated residential soils Hercules, Inc., had
excavated as a removal action in 1990 from contiguous residential
areas south of the site; (6) disposal of treatment residues
consistent with disposal of ash and salt that was generated by
the incineration of drummed wastes at the site; and, (7) the
construction of a RCRA Subtitle C landfill on-site.
A Unilateral Administrative Order (UAO) was issued to
Hercules, Inc., in March 1994 requiring it to perform the
remedial design and remedial action under the ROD for OU1.
Hercules' remedial design work plan has been approved. Part of
the work plan expressed interest in pursuing off-site
incineration as the means to perform the actions under the ROD.
Therefore, Hercules has signed a contract with APTUS, an off-site
commercial hazardous waste incineration facility. An Explanation
of Significant Difference (BSD) was issued in May 1995 by EPA to
allow such off-site incineration. Hercules has completed off-
site incineration of F-listed and non- F-listed liquids and
solids that were present in the process vessels. The remedial
18
-------
design is expected to be complete by the end of 1996. Hercules
has commenced construction of the on-site RCRA Subtitle C
landfill, with completion expected in November 1996. Also,
Hercules has commenced the off-site shipment of activated carbon
that was used for the treatment of leachate and storm water,
which should be completed by the end of 1996. All remedial
actions for this Operable Unit are expected to be completed by
the end of 1997.
Phase 5 SOILS AND UNDERGROUND UTILITIES (Operable Unit 2)
Operable Unit 2 (OU2) media are the subject of this ROD,
which addresses surface and subsurface soils, underground
utilities, foundations, curbs and pads. In addition, in
conjunction with an amendment to the 1990 Off-Site Areas ROD, the
ROD for OU2 addresses media originally intended to be addressed
by the 1990 Off-Site Areas ROD, which consist of cont-iguous soils
from the Rocky Branch Creek flood plain, sludge from the Old
Sewage Treatment Plant sludge digester, and the sediment from the
associated interceptor lines (which are considered to be
contiguous to the sita due to the continuous connection to the
site via the sewer interceptor). Finally, the ROD for OU2 also
addresses bagged soils Hercules had excavated from contiguous
residential yards in 1990 as part of a removal action, the
treatment of which EPA deferred in the OU1 ROD.
Because of the similarity of OU2 media to the media from the
1990 Off-Site Areas ROD and contiguous off-site residential soils
Hercules had excavated during a 1990 removal action, EPA has
chosen to address them in the OU2 ROD so that similar waste
materials associated with the Vertac site would be treated in a
consistent manner.
The 1990 Off-site Areas ROD called for the excavation and
incineration of soils in the flood plain area along Rocky Branch
Creek that had a 2,3,7,8-TCDD concentration greater than 1 ppb.
The estimated volume of flood plain soils is approximately 4,100
cubic yards. The 1990 Off-site Areas ROD also called for the
incineration of sludges removed from the digester and sediments
from the interceptor that connected the Old Sewage Treatment
Plant to the Vertac facility. The approximate volume of sludges
from the digester is 800 cubic yards, and the approximate volume
of sediments from the interceptor line is 2 cubic yards. The ROD
for OU1 deferred the treatment decision for the bagged soils
removed from residential yards as a part of a removal action in
1990. The total volume of bagged soil is estimated at 2,770
cubic yards. The final disposition of these materials will be
discussed in detail in Sections 7 and 9.
19
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Phase 6 GROUND WATER (Operable Unit #3)
Hercules completed the Remedial Investigation/Feasibility
Study (RI/FS) for this phase of the site cleanup in September
1995. Remedy selection is expected to occur in September 1996.
Ground water remediation at the Vertac site will pose
certain technical challenges due to the combination of complex
subsurface geology (tilted, fractured bedrock), and the presence
of dense nonaqueous phase liquids (DNAPL's). Ground water is
generally contaminated with chlorophenols,
^hlorophenoxyherbicides, and dioxin. More detailed information
on groundwater will be provided in the ROD for the Groundwater
Operable Unit (OU3).
5.0 SUMMARY OF SITE CHARACTERISTICS
5.1 DEMOGRAPHY AND LAND USE IN THE AREA OF THE SITE
The Vertac site covers approximately 192 acres on Marshall
Road within the city limits of Jacksonville, Arkansas, population
29,000. Approximately 1,000 residents live within one mile of
the site with residential areas bordering the entire east and
south sides. The west and northern sides of the site are bounded
by an industrial area and the Little Rock Air Force Base.
The Vertac site is currently zoned for industrial use and
has been used for commercial/industrial operations for
approximately 50 years. Land use zoning near the Vertac plant is
shown in Figure 3. The area just south of the Vertac site,
between Marshall Road and the Missouri-Pacific railroad tracks,
south to West Main Street, is a residential area made up of both
single family homes and apartments. The area immediately west of
the ra.L^oad tracks and north of West Main Street has recently
been developed and supports several light industries. The area
between West Main Street and South Redmond Road is commercial and
light industrial. Just south of South Redmond Roau is
undeveloped land that includes the Jacksonville Sewage Treatment
Plant, DuPree Park, and Lake DuPree. On to the south, the rest
of the area consists predominantly of irrigated rice fields and
woodlands.
As discussed in Section 4.0 above, EPA has evaluated the
past land use for the site, the current land use scheme for the
area surrounding the site determined by zoning ordinances, and
has held discussions with City of Jacksonville officials and
residents regarding land use. Based on this evaluation, EPA has
concluded that the reasonably anticipated future land use for the
site is commercial/industrial. Thus, EPA derived its site-
specific risk assessment based on that reasonably anticipated
future land use.
20
-------
SCALE W FEET
APPROXIMATE
Und Use Zoning Map
-------
5.2 SOILS AND GEOLOGY
5.2.1 Soils
Soils in the area of the plant are classified as the
Leadvale-Urban land complex with a 1 to 3 percent slope. The
Leadvale series soils are composed of moderately well-drained
soils in valleys, formed mainly of loamy sediment and washed from
uplands consisting of weathered shale, siltstone and sandstone,
such as those that underlie the site. Leadvale soils are
generally described as having moderately low permeability and a
seasonally perched water table. Tne Leadvale-Urban land complex
consists of areas of Leadvale soils that have been modified by
urban development. Because of the extensive development and
earth-moving activities at the site, natural soil characteristics
have been obscured.
5.2.2 Geology
The site lies in the transition zone between the Coastal
Plain and the Interior Highla^s Physiographic Province. The
surficial geology of the Coastal Plain Province in the region
surrounding the site is dominated by westward thinning wedge of
unconsolidated sediment consisting of the Tertiary Age Clairborne
Group, Wilcox Group, and Midway Formation.
The Clairborne Group and the Wilcox Group are
undifferentiated along the fall line that occurs in the site
area. The wedge onlaps the Rocks of Pennsylvanian Age lower
Atoka Formation, which dominate the geology of the Interior
Highlands Province in the region surrounding the site.
Quaternary alluvium and terrace deposits occur locally along
drainages in both provinces and are more common in the Coastal
Plain Province. A generalized summary of the geologic formations
surrounding the site is presented in Table 1. A map of the site
geoloTy is presented in Figure 4.
The contact between the Tertiary Age sediments and the
Pennsylvanian Age rocks occurs along a regional trend northeast
to southwest and is present in the area of the site. On a local
scale, the trend of the contact depends on the current erosional
surface and the paleotopographic surfaca of the Atoka Formation.
The strike of the Wilcox Group Sediments and the Midway Formation
tends toward the northeast-southwest. The dip of the sediments
is low and oriented toward the southeast. The Midway Formation
was deposited onto the irregular and weathered surface of the
Atoka Formation, which was folded and fractured during the late
stages of the Alleghenian orogeny. The Atoka Formation was later
uplifted and weathered. In the area of the site, the strike of
the beds in the Atoka Formation trends N70°W and dips about
35°NE. The Atoka Formation outcrops along Rocky Branch Creek on
the western side of the property.
22
-------
ERA
SYSTEM
rt
y
8
o
z
LLJ
U
U
3
SERIES
HOLOCENE
SUBDIVISION
ALLUVIUM
THICKNESS
(FEET)
0-50
LITHOLOGY
RED TO GRAY CLAY;
OCCASIONAt LY SiLTY TO SANDY
WATER SUPPLY
3ENERALLY NON-WATER
BEARING; DOMESTIC
SUPPLIES AVAILABLE
FROM BASAL UNITS
PLEISTOCENE
EOCENE
_ •
PALEOCENE
__
1
UPPER
CRETACEOUS
ALLUVIUM
AND
TERRACE
DEPOSITS
_
CLAIBORNE
GROUP
WILCOX
GROUP
Q
1
-7 IU
uiZ
-------
o
w
J>
Legend
Quaternary
Alluvium Red to Gray Clay.
Occasionally Silty to Sandy
Terrace Deposits Basal Sand and
Gravel Overlain by Fine Sand.
Silt an
^^_^ Tertiary
K^""1 Wilcox Group - Orange-red to
KaJl Red-brown Silty Sand to Silty Clay
•^^j Midway Formation Uyht Gray Cldy
Pennsylvanian
ra"5*l Atoka Formation - Interbedded
rajl^J] Sandstones. Siltstones and Shales
j/ Stike - Slip Fault Indicating Relative
-^^ Motion
''^ .Jormal Fault Indicating Dip Direction
Sources: C Stone, Cabot Geologic Quadrangle
Map. 1968
C Stone. Olmstead Geologic
Quadrangle Map. 1968
B Haley and C Stone. Jacksonville
Geologic Quadrangle Map. 1968
C. Stone and B. Haley. fV.cAlmont
Geologic Quadrangle Map. 1 968
N-
w
400
Seal* In FMt
GEOLOGIC MAP OF THE
JACKSONVILLE, ARKANSAS AREA
-------
5.3 HYDROLOGY
5.3.1 Surface Water
Because of the potential for surface runoff to transport
potentially contaminated soils off of the site, previous remedial
actions included the installation of sumps to collect the first
flush of surface water runoff from the central process area for
treatment. After treatment, this water is discharged to Rocky
Branch Creek. Runoff that exceeds the capacity of the sumps
currently flows to the Rocky Branch Creek. This ROD will in part
address potentially contaminated sedimer'. j that bypass the sumps
after they are inundated by heavy rains. See Section 7.2, Storm
Water Runoff Control.
There are two major drainageways in the area, Rocky Branch
Creek, and Bayou Meto, which is a tributary to the Arkansas
River. Rocky Branch Creek flows through the part of the site
west of the central process area. Approximately 2 miles
downstream, Rocky Branch Creek flows into Bayou Meto.
Surface drainage ditches on the western part of the site
direct local runoff westward toward Rocky Branch Creek. An
earthen dam was constructed across the creek in the early 1950's
to form a cooling water pond that was used to supply non-contact
cooling water to the plant.
At its maximum extent, the pond extended to a distance of
about 1,000 feet north of the dam. The pond was adjacent to the
north burial area. The dam was removed and the cooling water
pond was closed in July 1985. Rocky Branch Creek was diverted
around the location of the former cooling water pond as a part of
the pond c3 sure. The diversion is maintained today by an
earthen dike along the eastern side of the creek.
Surface water runoff from the western part of the central
process area, including the central ditch that transects the
central process area, is contained in drainage ditches that
divert the initial runoff to sumps. The sumps are connected to
the wastewater treatment plant, which uses activated granular
carbon to treat the water.
Surface drainage ditches in the northeastern part of the
site direct runoff eastward toward a primary ditch that lies
along the western side of Marshall Road. ,This ditch directs
water toward Rocky Branch Creek south of the site.
5.3.2 Ground Water
This ROD does not address the ground water issue. The
Operable Unit 3 ROD, scheduled for September 1996, will address
ground water contamination.
25
-------
Ground water in the region surrounding the site occurs in
both the overburden and the underlying bedrock. The overburden
and bedrock are generally not considered as major sources of
ground water near the site. Ground water supplies in the region
are obtained from the unconsolidated sands and gravels in the
Tertiary and younger Quaternary sediments. Most ground water is
produced from wells completed in the sands within the Wilcox
Group and basal sands and gravels within the Pleistocene alluvium
and terrace deposits. Yields from these deposits can range up to
2,000 gallons per minute (gpm). Ground water in the
unconsolidated sediments is present in the primary intergranular
pore space. Some domestic ground ^ater supplies are obtained
from the Atoka Formation. Yields can range up to 10 gpm. Ground
water in the bedrock is present in fractures and partings within
the rock.
The hydrology in the area of the site is influenced by the
location of Rocky Branch Creek, the French drain, the central
ditch, and the hydraulic characteristics of the overburden,
weathered rock, and bedrock.
5.4 REMEDIAL INVESTIGATION FINDINGS
5.4.1 Background
Site investigations and remedial actions have been performed
at the site since 1978. Figure 5 shows an overview of the
remedial action performed at the site to date, mostly involving
the closing of a cooling water pond, capping old landfills and
burial areas, and the installation of a french drain leachate
collection system around the landfills and an on-site wastewater
treatment plant. Hercules, Inc., completed the RI for OU2 Phase
1 in December 1992 which addressed surface and subsurface soils,
shallow ground water, and underground structures such as
underground utilities, foundations, curbs, pads and fuel storage
tanks. The USTs have since been addressed. Hercules, Inc.,
emptied these underground storage tanks (USTs) and filled them
with grout. The OU2 Phase 2 RI, completed in September 1995,
principally addressed deep ground water contamination and some
additional soil investigation in the northern part of the site.
Ground water has since been split off into a separate operable
unit (OU3) for the purpose of expediting the completion of the
soils and underground structures remediation effort and is not a
part of this ROD.
The RI for OU2 has shown that the nature and levels of
contaminants found in the soils at the site tend to parallel
particular process areas of the plant. The central process area
of the site has been divided into 10 subareas based on
operational activities (see Figure 6). They include the
following:
26
-------
O
M
Ul
,
-1L.
JIP^ i .'/ '
'Jl!<« -^
|I*-'"'U
fc- I
\\*%%Ji- •:• H
{ *> '^ * A ' ") ^ v / 1
r, yJjBP"^ 'Ml '* y' J Excavated Surface Soils Area
im Asphalt-Capped Blow Out Area
fc%%) Scraped Areas
• -o- - — French Drain
•• Slurry Wall
Fence Line
miiiriii j Central Ditch
• < • Railroad
""•" Diversion Dike
•"•• •— • Clay Barrier Wall
Gunnlte-Covered
• Surface Water Sump
v /. / ' \ Buildings and Foundations
N
nr ^^ c
^
s
0 400 800 1200
Seal* In F«*t
Source: vertac Site Boundary and Pnotogiammeiric
Survey Prepared by Weil an 1 Associates. Inc
Projection: Arkansas Coordinate Syitem.
North Zone (NAD i 983|
AREAS OF PREVIOUS REMEDIATION
VERT AC SITE
JACKSONVILLE, AR
-------
Tl
M
O
?d
a
ON
ESTERflCATION
PLANT
DALAPON
PRODUCTION \ |
» 1L AREA «.
EXISTING
QtORMATIOM
PLANT 9TE
FORIO CHIOBNATION
PLANT STE
RECYOI UQUOR
STORAGE AREA
FORMULATIONS
AREA
2.4,5-T
PRODUCTION
AREA
PRODUCTION ARIAS
CENTRAL PROCLSS
BOUNDARY
VERTAC SITE PROCESS AREA
-------
• Maintenance Area - used for equipment repairs and storage of
equipment, parts, and some raw materials.
• Formulations Area - used for the storage of raw and finished
products (large warehouse and some process vessels).
• Former Chlorination Plant Area - used in manufacturing 2,4-D
herbicide.
• Existing Chlorination Plant Area - built in early 1980's and
replaced old Chlorination plant.
• Esterification Plant - used to add alcohols to increase
solubility of the herbicide to water.
• Dalapon Production Area - used in manufacturing dalapon
(1,1,1-trichloropropionic acid).
• Recycle Liquor Storage Area - used for the storage of
manufacturing materials such as recycle liquor, caustic
soda, and spent solvents. Currently used to store drums
generated by ongoing site activities.
• Recovery Plant - used in the treatment of process wastes.
2,4-D waste were recovered, and drums containing 2,4-D were
washed.
• 2.4.5-T Production Area - used in manufacturing of 2,4,5-T
herbicide.
• Acid Plant - chlorophenols were reacted with acetic acid and
monochloroacetic acid to form phenoxyacetic acid herbicides.
The area around the Regina Paint Building, located in Parcel
1 (north area of the site) is included in OU2 because the
building was used to store empty drums that had been used to
handle or store wastes from the manufacture of 2,4,5-T.
The media addressed in the OU2 RI include:
Surface soils
Subsurface soils
Tetrachlorobenzene (TCB) spill area
Underground utilities
Building Foundations and Curbed Areas
Underground Storage Tanks (USTs)
The USTs have since been addressed. Hercules, Inc., emptied
these USTs and filled them with grout. Therefore, they will not
be addressed in this ROD.
29
-------
Other media that will also be addressed in this ROD include;
• Off-site soils from Rocky Branch Creek flood plain
(1990 ROD).
• Sludge from the Old Sewage Treatment Plant sludge
digester, and sediments from the interceptor line.
(1990 ROD).
• Bagged soils excavated from residential yards
(1993 ROD).
Remediation of the off-site soils, sludges from the off-site
sewage digester and sediments from the interceptor line, and
bagged soils from a residential removal action were originally
addressed by EPA as response elements in previous ROD'S and
removals. However, because of the similarities of these media,
and the wish to Lreat similar media In a consistent manner, EPA
now will address these media with the on-site soil media.
The ROD for the off-sit^ area, dated September 1990, called
for the excavation and incineration of soils in the flood plain
area along Rocky Branch Creek that had a 2,3,7,8-TCDD
concentration greater than 1 ppb. The estimated volume of flood
plain soils is approximately 4,100 cubic yards. The off-site ROD
also called for the incineration of sludges removed from the
digester at the Old Sewage Treatment Plant and sediments from the
interceptor line. The approximate volume of sludges from the
digester is 800 cubic yards and the sediments from the
interceptor line is about 2 cubic yards. The ROD for OU1
deferred the treatment decision for the bagged soils removed from
residential yards as a part of a removal action in 1990. The
total volume of bagged soil is estimated at 2,770 cubic yards.
5.4.2 Sampling Results for Surface S«ils
During the period between 1989 and 1992 approximately 461
grids were established for the purpose of determining the level
of contaminants present across the site. EPA, IT Corporation,
Hercules, Vertac Site Contractors, and Weston (contractor for
Hercules) were principally responsible for the collection of this
information (see Figures 7, 8, and 9; early grid sampling,
surface grid locations in the central process plant area, and
surface soils sampling outside the central process plant area,
respectively).
Over 180 grids were sampled under the OU2 Phase 1 RI. The
majority of the grids were located in the central process area
and were approximately 5,000 square feet. These grids were
sampled for 2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol,
2,6-dichlorophenol, 2,3,6-trichlorophenol, 2,4,5-trichlorophenol,
2,4-D, Silvex, 2,4,5-T, and 2,3,7,8-TCDD. Grids outside the
30
-------
1 U S Environmental Protection Agency Surface
«>' I Sol Samplng Grtd and Number
' Nuttoera ftx EPA Grteh and Grab S*mpto
Range Item 001 Tnrou/i 282
V US EiMfonmental ProtKDon Agency Stxtoce
Grab Sampling Location and NunDe<
Hrtrmjoonal Technology Surface Sol Sampkng I
Grtd and Nunntxr
NurOen tor mtemaDonal Tecnnology Grids
Range from 800 Tnrougn 820
H Venae Sat Canracion Surface Soil Samplng
Grid and Number Symbol Represents Grab
Samptng Location and Number
Number* tor Venae Ske Contractor! Grids
Range from 900 Tnrougn 949
X Venae SKr Contractors Surface SoU Grab
Sampftng Locabon and Number
• GndJ VWiere Elevated ConcennaDons
t>20 ppb) of 2.3.7.8-TOX) Were Found
~ Central Process Area Boundary
Property Boundary
250
500
750
Source Wmc Ste Boundary «nd FYioaDQrammccnc
Survey Prepared by Wca *nd AUOCIMH. me
QRID8 FROM PREVIOUS SURFACE
SOIL SAMPUNQ 8URROUNOMQ THE
CENTRAL PROCESS AREA
VERT AC SITE
JACKSONVILLE, AR
-------
CPtTKAl MOCtSS ««» BOUNWr
~~"= ""
I . WESTON Surface Son Sampang Odd and
" I Nuiroer Numbers for WESTON Gndj «nd
Grab Samples Rang* from 400 Through 5«5
WESTON Surface Son OcaD Sampung
Locaoonand NumtMr
556
(Tj WESTON Surface SON Sampling. Location Wltnn
ttie Blow Out Afea
^ ; Environmental PrattcOon Agency
Surface Son Sampano end and Numoet
~ ~— Central Proccu Are* Boundary
•541T54T- 550 bbl
Source: Veruc Site Boundary and Photogrammetric
Survey Prepared by West and Aisociatci. inc
SURFACE SOIL SAMPLING GRIDS
AND GRAB SAMPLING LOCATIONS
WITHIN THE CENTRAL PROCESS AREA
VERT AC SITE
JACKSONVILLE, AR
-------
Ti
PI
D
Inul No. 2
JSL
No. 2
—— Outline of Grids Outside the Central Process Area
Q WESTON Surface So* Samomg Odd and
Number. Numbers for WESTON Gods and
Grab Samples Range from 400 Through S85
»4t
° WESTON Surface So* Grab Sampttig Location
and Number
•"* WESTON Surface Soil Sampling Location WWnn
me Blow Out Area
Central Process Area Boundary
Property Boundary
400
800
120
Scatoln F««t
Source: Venae Site Boundary and Photogrammetnc
Survey Prepared by U/eu and Associates, me
SURFACE SOIL SAMPLING GRIDS
OUTSIDE THE CENTRAL PROCESS AREA
VERTAC SITE
JACKSONVILLE, AR
-------
central process area are approximately 40,000 square feet and
were screened for 2,3,7,8-TCDD only, because these areas were
outside of known production operations. Eleven samples were
collected from a series of 11 uniform nodes within each grid.
From those 11 samples three composites were made and
analyzed for 2,3,7,8-TCDD. Essentially all areas exhibiting
elevated TCDD concentrations are located in the central process
area, and relative concentrations of chlorophenoxyherbicides and
chlorophenols measured in the surface soils paralleled dioxin
concentrations.
Most of the unsampled areas of the site were generally in a
downstream direction from sampled areas exhibiting TCDD
concentrations of 2 ppb or less. Tabla 2 depicts the maximum and
average concentrations for the contaminants of concern (COC's) at
the site.
Table 2.
CHLOROPHENOLB
2-chlorophenol
4-chlorophenol
2 , 4-dichlorophenol
2 , 6-dichlorophenol
2,3, 6-trichlorophenol
2,4, 5-trichlorophenol
2,4, 6-trichlorophenol
CHLOROBEN2ENE8
Trichlorobenzene
CHLOROPHENOXYACIDS
2,4-D
Silvex
2 , 4 , 5-T
MAXIMUM CONG.
3 ppm
o . 12 ppm
360 ppm
15 ppm
0.73 ppm
270 ppm
79 ppm
17,000 ppm
5,500 ppm
290 ppm
710 ppm
AVERAGE CONG.
1.9 ppm
not computed
6.9 ppm
0.54 ppm
0.54 ppm
2.0 ppm
3.5 ppm
not computed
191 ppm
12.4 ppm
23.1 ppm
TCDD concentrations at the site ranged between non-detect to
2,800 ppb. The highest concentrations of TCDD found in surface
soils at the site were in the following areas (note: TCDD
concentrations are reported as the 95 percent upper confidence
limit for each grid sampled in an area):
34
-------
Blow Out Area - For the seven grids sampled in this area
TCDD concentrations ranged between 0.25 ppb for the least
contaminated grid to 660 ppb for the most contaminated grid.
The dioxin in this area is associated with occasional
releases or "blow outs" during facility operations from the
reactor vessel when the control of the chemical reactions
was not maintained. After such a release, the solidified
2,4-D and 2,4,5-T was scraped from the ground and replaced
with a thin layer of clean fill material.
East Drum Storage Field Area - TCDD concentrations for this
area ranged between 7.3 ppb and 120 ppb.
The east drum storage field can be subdivided into two
distinct areas. The first area includes the drainage grids
along the northern side of the site entrance road. Dioxin
in this are^ was most likely transported there from the blow
out area. The second area is located in the western part of
the drum field. Soil contaminants are most likely related
to spillage from, the drum storage operations.
Main Boiler House Area - TCDD concentrations in this area
ranged between 0.39 ppb and 1,270 ppb.
This area acted as a sediment retention basin, and since it
is located downslope from the blow out area, TCDD is likely
present from sediment migration from the blow out area.
Area East of the Main Boiler House - TCDD concentrations in
this area ranged between non-detect and 98 ppb.
This area is down slope from the main boiler house.
Therefore, the TCDD may have originated at the blow out area
and migrated with sediments from the main boiler house area.
Area of the Existing and Former Chlorination Plants - TCDD
concentrations in this area ranged between 22 ppb and
2,800 ppb.
Portions of this area were used to dry 2,4,5-T, and TCDD is
suspected to be present as the result of these drying
practices.
Maintenance Area - TCDD concentrations in this area ranged
between 4.8 ppb and 57 ppb.
Previous overpacking of leaking drums in this area may have
contributed to the TCDD found in this area.
35
-------
5.4.3 Subsurface soils
During the RI, numerous subsurface soil samples were taken
from soil borings throughout the site. The purpose was to
determine whether significant sources of contamination existed
below the surface soils which could potentially migrate and
degrade water quality. Analyses were performed on these samples
to quantify the concentrations of chlorophenols,
chlorophenoxyherbicides, and TCDD in these soils.
Of more than 90 samples taken and analyzed for TCDD, only 5
vere greater than 20 ppb. The ra-ge of the 5 samples were
between 20 ppb and 310 ppb. These elevated levels were all
obtained in different borings and at different depths.
The vertical extent of TCDD at depths greater than 36 inches
appears to be related to areas where burial occurred such as the
chlorination area, or where sediments may have accumulated such
as the main boiler house area. The vertical extent of TCDD
between 12 and 36 inches is limited to areas where the land
surface may have been built up during subsequent site activities,
such as the blow out area, and south of the chlorination area.
The data suggest that TCDD contamination between 12 and 36 inches
of soil depth is not the result of downward migration of TCDD
from the surface.
5.4.4 Tatrachlorobanzanc Spill Araa
The tetrachlorobenzene (TCB) spill area resulted from an
accidental release of TCB from a railroad car. Molten TCB filled
the low area between the railroad tracks and penetrated into the
soils pore spaces under the tracks before crystallizing. The
spill area is about 830 square yards, based on where TCB was
observ The western limit was noi found because access for
excavation was impeded due to physical obstructions at the site,
e.g.. building foundations, etc. The vertical extent was also
not determined at the time of the RI for similar rtasons. The
horizontal and vertical extent of the TCB contamination will be
determined during the remediation process. TCB was found at
concentrations ranging between 200 ppm and 1,700 ppm in pit
samples at depths of 32 to 34 inches below ground surface.
5.4.5 Underground Utilities
Because TCDD tends to adsorb to clay-rich and organic-rich
soils and due to the potential for the compound to migrate with
these sediments if they are transported by water flow, samples
were taken from several underground utility lines including the
industrial and sanitary sewer lines as well as surface water
sumps. Pressurized piping (natural gas lines and public water
lines) were not sampled since there was no accessible point of
36
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entry to these lines at the site due to the fact that they were
under constant pressure.
Five samples were collected for each structure.
• Industrial Sewer - sediment samples showed the highest TCDD
concentrations of any underground utilities, with the
concentrations ranging between 7.3 ppb and 79 ppb.
• Surface Water Sumps - sediment samples for TCDD from the
surface water sumps ranged between 8.4 ppb and 18 ppb, and
are generally consistent witr the soil concentrations within
the central process area.
• Sanitary Sewer - the lowest concentrations of TCDD were
found in the sanitary sewer system and ranged between non-
detect to 4.1 ppb. Measurable concentrations of TCDD were
found in the on site sewer lines extending southeastward
from the central process area. No TCDD was found in the
currently active portions of the sanitary sewer which
extends southward of the site.
• Porous Bedding Material around Underground Utilities - there
is no field information or design drawings available that
indicate whether or not granular material was used for
bedding of these lines. Therefore, the potential for
preferential flow of ground water in bedding material around
the outside of utility piping may exist at the site.
5.4.6 Underground Storag* Tanks (USTa)
A survey of the USTs for the site indicated the presence
of 5 tanks, with capacities ranging between 250 gallons and 1,000
gallons. All 5 tanks have previously been used to store gasoline
or diesel fuel. The approximate volume of residual fuel in the
tanks is as follows:
UST1 - 42 gallons
UST2 - 57 gallons
UST3 - 17 gallons
UST4 - 35 gallons
USTS - 208 gallons
Since the preparation of the RI and FS, all 5 tanks have
been pumped dry and backfilled with grout containing a mixture of
sand, cement, and flyash by Hercules, Inc. Subsurface soil
samples around the UST's for petroleum hydrocarbons, lead,
benzene, toluene, and xylenes do not indicate the presence of any
significant leaks from these USTs.
37
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5.4.7 Off-ait* Rocky Branch Creek and Bayou Meto Flood Plain
Soils
One element of the 1990 Off-site ROD called for the
excavation of flood plain areas that are currently zoned
residential where the TCDD concentrations are greater than 1 ppb.
Approximately 4,100 cubic yards of soils are estimated to contain
dioxin above the cleanup goal. The highest TCDD concentration
found in this area was 9.6 ppb. The remedy in the 1990 ROD also
called for these soils to be brought back to the Vertac site for
on-site incineration. EPA subsequently deferred the treatment
requirement for these soils such that all site soils could be
handled in a consistent manner. The remediation of these soils
has now been incorporated into this ROD. For more information
see the Vertac Superfund Site Record of Decision for Off-site
Areas, September 1990. The final disposition of the flood plain
soils is discussed in Section 9.0 of this document.
5.4.8 Residential Bagged Soils
In 1988, EPA signed an Administrative Order on Consent (AOC)
with Hercules, Inc., requiring it to remove soils from
residential yards south of the Vertac plant where TCDD was found
above 1 ppb, and a drainage ditch on-site in the area of the
residences. Approximately 2,770 cubic yards of soils were bagged
and placed in a storage facility at the site. Chlorinated
phenols, chlorinated benzenes, and chlorinated phenoxyherbicides
were present at non-detect to low concentrations. TCDD was
detected in all samples at levels ranging from 13 ppb to 55 ppb.
The 1993 ROD for Vertac On-site Operable Unit 1 (above ground
media) deferred the treatment requirement for these soils so that
all site soils could be handled in a consistent manner. The
remediation of these soils has now been Incorporated into this
ROD. For more information see the Record of Decision, Vertac
Superfund site - Operable Unit 1, June 1993. The final
disposition of the residential soils Hercules, Inc., excavated as
part of a removal action is discussed in Section 9.0 of this
document.
5.4.9 Sludges and Sediments from the Old Sewage Treatment Plant
Digester
One element of the Record of Decision for the Vertac Off-
Site Areas, dated September 1990, called for cleanup and
demolition of the old Sewage Treatment Plant. As a part of that
ROD, approximately 890 cubic yards of sludge from the sludge
digester was removed in 1994 using a vacuum pumping system. The
sludge was then transported back to the Vertac site for on-site
incineration. The maximum concentration of TCDD found in the
sludge digester sediments was 12.5 ppb. Another element of that
ROD called for the removal of sediments from a sewer interceptor
line, which physically connected the Old Sewage Treatment Plant
38
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to the Vertac facility. Approximately 2 cubic yards of sediments
were removed from the interceptor line in 1994 and transported
back to the Vertac site for on-site incineration.
EPA subsequently deferred the treatment requirement for
these sludges/sediments so that all such site materials could be
handled in a consistent manner. As discussed at Section 4.0
above, those media are considered to constitute low level threats
due to the fact that the average level of dioxin contamination in
those media is well below 5,000 ppb, which is three orders of
magnitude above the site's 5 ppb cleanup level identified in the
risk assessment. See EPA's guidance on low level and principal
threats cited at Section 4.0, OSWER Directive No. 9380.3-06FS.
Therefore, the remediation of these sludges/sediments has now
been incorporated into this ROD. For more information see the
Vertac Superfund Site Record of Decision, Off-Site Areas, dated
September 1990. More discussion on the final disposition of
these sludges a^.J sediments is included in Section 9.0 of this
ROD.
6.0 SUMMARY OF SITE RISKS
6.1 RISK ASSESSMENT DESCRIPTION
An evaluation of the potential risks to human health and the
environment from site contaminants associated with Operable Unit
2 media was presented in a separate document called the OU2
Baseline Risk Assessment. The baseline risk assessment was
completed in concert with the development of the RI/FS. The
purpose of the baseline risk assessment is to evaluate the
potential risk to human health and the environment from site
contaminants prior to remediation. The results from the baseline
risk assessment are used to establish cleanup goals for the
contaminants at the site that pose the greatest risk. The OU2
baseline risk assessment is divided into two main sections, the
Human Health Risk Assessment and the Ecological Risk Assessment.
In general, a risk assessment is a procedure which uses a
combination of facts and assumptions to estimate the potential
for adverse effects on human health and the environment from
exposure to contaminants found at a site. The environmental or
ecological risk assessment is conducted to determine if there are
any current or potential impacts on ecological receptors
attributable to the unremediated site. Human health risks are
determined by evaluating known chemical exposure limits and
actual concentrations at the site as identified during the RI
sampling activities. In the risk assessment, carcinogenic risks
(from chemicals that are known or believed to cause cancer) and
non-carcinogenic health risks (from chemicals that are not known
39
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to cause cancer, but can cause a range of other illnesses) are
calculated.
6.2 IDENTIFICATION OF CHEMICALS OF CONCERN
This section summarizes the site data that were used to
evaluate potential health risks to human and nonhuman receptors.
The substances that were considered for each exposure medium
include the following:
• Surface Soil - Chlorophenols
Chlorophenoxyherbicides
- 2,3,7,8-TCDD
• Ground Water - Acetone
Chloroform
Chlorophenols
Chlorophenoxyherbicides
- Methylene Chloride
- Nitroaromatic explosives
Priority pollutant metals
- 2,3,7,8-TCDD
- Tetrachlorobenzene
- Toluene
• Surface Water - Chlorophenols
Chlorophenoxyherbicides
- 2,3,7,8-TCDD
- Toluene
An effort was made to focus the risk assessment on those
chemicals that are of greatest concern for a given medium.
Chemicals that were infrequently detected in a medium that was
sample^ systematically, unless there was evidence for a "hot
spot", were eliminated (see U.S. EPA guidance, 1989 (b)).
Tables 3, 4, and 5 present the data summary for substances
of potential concern for each medium and their frequency of
detection. Please note that the terminology used in Tables 3
through 5 is consistent with the terminology set out in the EPA
guidance document "Supplemental Guidance to Risk Assessment
Guidance for Superfund (RAGS): Calculating the Concentration
Term," OSWER Publication 9285.7-081, 1992. Therefore, the term
"Upper 95% Confidence Limit of the Geometric Mean" used in Tables
3 through 5 actually means the upper 95% confidence limit of the
arithmetic mean. However, when evaluating the combined risk
posed by all the COC's at the site, dioxin contributed over 99
percent of the total risk.
40
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Substances of Potential Concern in Soil
Data Summary — All Samples
W
UJ
Substance
2-Chlorophenol
2,4-D
2,4-Dichlorophenol
2,6-Dichloropbenol
quency
e
of
ection*
>/138
2/127
7138
1/138
3/124
5/129
/1.146
1/1
J/137
J/136
Range of
Sample
Quantitation
Limits
(mg/kg)b
0.33-18
0.023-4.2
0.042-18
0.33-18
0.012-670
0.012-670
0.01-4.5
(ng/g)
NI
0.33-3.8
1.7-91
Range of
Detected
Concentrations
(mg/kg)b-<
0.047-3.0
0.0053-5,500
0.034-360
0.066-15
0.0012-290
0.0016-710
0.04-2,200
(ng/g)
670,000
0.033-270
0.047-79
Adjusted
Geometric
Mean
Concentration
(mg/kg)b
0.34
580
3.0
0.54
28
63
5.3
(ng/g)
NA
1.9
2.6
Upper 95%
Confidence Limit
of the Geometric
Mean
Concentration
(mg/kg)b
0.39
3,100
5.0
0.66
110
250
9.2
(ng/g)
NA
3.0
3.4
Tetrachlorobenzened
2.4.5-Trichlorophenol
2.4.6-Trichlorophenol
NA = Not applicable
M = Information was not available
r i tinns at which the substance was detected to the total number of sampling locations, with the exception of
•Ratio of the number of sampling locauon^ ^ 2,3,7,8-TCDD is the ratio of the number of composite samples in which 2,3,7,8-TCDD was detected to
237 8-TCDD. The frequency ot aete
the total number of «>mP°s'%Jlgg^mch is expressed in units of ng/g. .
•"""•- the exception of 2,3, /,»-»cr~' .. low the minimum sample quantitation limit.
. ... ._....!—k ore esiimdicu . fc,,^^rt;nn i M
i the hot spot analysis
-------
Substances of Potential Concern in Groundwater
Data Summary — Atoka Formation
I
M
Upper 95% Confidence
Limit of the Geometric
Mean Concentration
(mg/L)b
Range of Detected
Concentrations
(Range of) Sample
Cuantitation Limit(s)
Adjusted Geometric
Mean Concentration
Frequency of
Detection*
2-Chlorophenol
4-ChiorophenoI
0.00015-1,640
2,4-D
•MVM«
2.6-D
-•
2.4-Dichlorophenoj
2.6-Dichlorophenol
•. —^•••^•^
Methylene chloride
^^•^^^•^•M
Phenol
0.005 0.06
_-—— 11.^^
0.005-0.82
0.005-0.063
0.005
0.0005-0.54
—i "• -
0.00013-0.007
>«^BI^"~
0.005
0.85-2,080
(ng/L)
0.01-1.8
(ng/L)
2,3,7,8-TCDD
Tetrachlordbenzene
Toluene
2 3 6-Trichlorophenol
2 4.5-Trichlorophenol
0.005-0.82
.. i '••••
0.005-4.1
-------
r1
«
-p-
o
o
3
Substance
Organic* (continued)
2.4.6-Trichlorophenol
Inorganics
Antimony
Arsenic
Chromium
Copper
Lead
Mercury
Nickel
Silver
Thallium
Zinc
Substances of Potential Concern in Groundwater
Data Summary — Atoka Formation
(continued)
Frequency of
Detection*
38/80
3/26
2/26
j/26
3/26
2/26
9/26
10/18
11/26
4/26
22/22
(Range of) Sample
Quantitation Limit(s)
(mg/L)b
0.005-0.82
Range of Detected
Concentrations
(mg/L)b*
0.001-94
Adjusted Geometric
Mean Concentration
(mg/L)J
2.1
Upper 95% Confidence
Limit of the Geometric
Mean Concentration
(mg/L)b
9.9
0.060
0.010
C.010
0.025
1,003
0.0002-0.00025
0.040
0.010
0.010-0.10
0.020'
0.022-0.029
0.0036-0.013
0.0020-0.012
0.0066-0.025
0.0036-0.011
0.00022-0.00076
0.011-0.109
0.0034-0.0094
0.010-0.100
0.011-0.270
0.029
0.0053
0.0050
0.013
0.0018
0.00023
0.032
0.0056
0.031
0.043
0.030"
0.0056
0.0055
0.014
0.0021
0.00031
0.049
0.0060
0.060
0.063
,5, detected during one or more sampling rounds to the total number of wells sampled.
f
"With the exception of
"Exceeds the maximum reported
'Sample quantitation limits were not
......
concentrations, usually below the minimum sample quantitation limit.
contract-required detection limit/instrument detection limit (CRQL/IDL) is indicated.
-------
Substances of Potential Concern in Surface Water
Datp. Sumi ary — All Sample Locations
r1
M
Substance
2-Chlorophenol
4-Chlorophenol
2,4-D
2,6-D
2,4-Dichlorophenol
2,6-Dichlorophenol
Phenol
Silvex
2,4.5-T
2.4,6-T
2,3,7,8-TCDD
Toluene
Frequency of
Detection'
6/6
6/6
6/6
6/6
6/6
6/6
6/6
6/6_
6/6
6/6
3/6
.ange of
Sample
antitation
Limits
(^/L)b
0.8-5
1.1-5
2-5
2-5
1-5
0.5-50
0.6-5
1-2
1-2
1-2
2-10
(ng/L)
5-21
Range of Detected
Concentrations
(^g/L)b'c
0.85-460
1.2-8,800
2.9-17,000
2.0-5,400
1.8-6,800
1.0-1,100
0.60-620
1.0-1,100
1.7-3,300
1.1-11,000
2.0-12
(ng/L)
0.022-3,900
Adjusted
Ge ^metric
Mean
Concentration
(^g/L)b
18
230
1,100
500
200
13
24
84
200
240
1.6
(ng/L)
52
Upper 95%
Confidence Limit
of the Geometric
Mean
Concentration
(^/L)b
420
480,000d
2,700,000d
45,000d
290,000d
350
4,600d
18,000d
44,000"
33,000d
1.9
(ng/L)
9,900d
-------
r1
w
o
o
3
Substances of Potential Concern in Surface Water
Data Summary — All Sample Locations
(continued)
.ange of
Sample
antitation
Limits
(/WL)b
1.2-50
1.5-5
1.1-5
Range of Detected
Concentrations
(A€/L)b'c
2.0-69
1.6-5,000
1.7-1,500
Adjusted
Geometric
Mean
Concentration
(/4S/L)b
4.1
130
29
Upper 95%
Confidence Limit
of the Geometric
Mean
Concentration
(/^g/L)b
12
350,000"
2,500d
•Ratio of the number of
"With the exception of 2,.,,.,- - ----•
Includes "J" values, which are estimated below
«Emb the maximum reported concentrate
I rinns at which :ae substance was detected to the total number of sapling locations.
11 ^ ed •„ ^ of ng/L.
-------
6.3 HUMAN HEALTH RISK ASSESSMENT
6.3.1 Summary
A baseline risk assessment was conducted for the Vertac site
where risks were evaluated using current site conditions for
three potential receptor scenarios: teenage trespasser, current
unprotected worker, and future unprotected worker. Exposure
routes assessed for the trespasser scenario included dermal
contact with soil, incidental ingestion of soil, contact with
surface water, and inhalation of particulates or vapors.
Exposure routes accessed for the current unprotected worker
scenario included incidental ingestion of soil, dermal contact
with soil, dermal contact with surface water and water from the
production outfalls at the site, and the inhalation of airborne
particulates and vapors. A future unprotected worker was assumed
to be exposed to the same substances of concern as the current
unprotected worker uith the addition of the ingestion of site
ground water. It should be noted, however, that the cleanup goal
proposed by EPA for the site does not consider that a future
worker will be consuming grov-^ water. Public water supplies are
readily available and the future use of site ground water as a
drinking water source will be prohibited through institutional
controls.
6.3.2 Exposure Assessment
The potentially exposed populations and the pathways through
which they could be exposed for current and future site
conditions are discussed below.
Current and Future Land Use
As discussed in Section 4.0 above, EPA has evaluated the
past land use for the site, the current land use scheme for the
area surrounding the site determined by zoning ordinances, and
had discussions with City of Jacksonville officials and
residents. EPA has concluded that the reasonably anticipated
future land use for the site is commercial/industrial, which is
consistent with past land use and the current zoning for the site
area. EPA's risk assumption for OU2 presupposed that future land
use would be commercial/industrial, and so EPA derived the site's
cleanup level of 5 parts per billion (ppb) toxicity equivalents
(TEQ) for dioxin due to the fact that a commercial/industrial
human exposure scenario assumes that a worker would be exposed to
post-cleanup dioxin levels over a 40 hour per week period. This
worker exposure scenario additionally is protective of a
trespasser or a passerby, both of whose exposure period would be
less than that of a site worker. In deriving the 5 ppb dioxin
cleanup level, EPA assumed that the pathways of exposure to site
contaminants likely for future site workers would be soil
ingestion, dermal absorption from soil, soil inhalation, vapor
46
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inhalation or dermal absorption from volatilization of surface
water. In addition, EPA assumed a soil inyestion and dermal
absorption pathway from soil for a trespasser or an occasional
passersby.
Thus, EPA derived its site-specific risk assessment based on
that reasonably anticipated future land use. The land occupied
by the Vertac facility is zoned commercial/industrial. While
there are no manufacturing operations at the site, it is
reasonably anticipated that future use could include commercial
development. Continuing activities include general maintenance
of the plant, maintenance of previous remedies, and operation of
a wastewater treatment plant by PRP site maintenance workers.
Deed restrictions are in place that will prevent future
residential development of the site. Additional deed
restrictions will be sought to limit future commercial
development of portions of the site that will contain waste
disposal areas and are otherwise encumbered by long terr.
remediation and perpetual operation and maintenance activities.
The land located west and north of the plant is also used
for commercial/industrial purposes. Residential areas are
located directly east and south of the plant.
To assess the current and reasonably anticipated future land
use, four receptors were evaluated: A trespasser, a passerby, a
current unprotected worker, and a future unprotected worker.
Trespassers and workers are the most likely future receptors at
the site and represent those individuals with the highest
potential for exposure to site related substances of concern.
A trespasser could enter the site unnoticed by either
climbing or crawling under one of the fenres either currently or
in the future. A teenager between 12 and 18 years of age was
evaluated for this scenario.
A passerby could walk by the east side of the site along
Marshall Road in the future. A teenager between 12 and 18 years
of age was evaluated for future exposure using this scenario.
Although any exposure is considered remote using this future
scenario, it was evaluated since the strip of property along the
west side of Marshall Road may eventually be unrestricted and
without a fence, allowing for future commercial/industrial
development.
Current and future worker scenarios were also evaluated.
Because this site is zoned commercial/industrial, a maintenance
worker is the individual who has the greatest potential to
contact on-site media on a regular basis, both currently and in
the future.
47
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Potential Exposure Pathways
Trespasser
It is possible for a trespasser to be exposed to substances
of concern on the site through contact with soil, surface water,
and air. Potential soil exposure routes include dermal contact
and incidental ingestion of soil.
Of the on-site surface waters, a trespasser is most likely
to come into contact with Rocky Branch Creek, which is located
within the western margin of tlie site. Due to the shallow nature
of the creek, with a depth of approximately 1 foot, only dermal
contact was evaluated. The potential for a trespasser to come
into contact with outfalls that flow to Rocky Branch Creek was
considered to be unlikely, due to the fact that they flow only
during periods of high rainfall.
The trespasser could also be exposed to chemicals of concern
through the inhalation of airborne substances originating from
surface soil and surface water (particulate and/or vapor).
The potential for a trespasser to become exposed to site
ground water was considered to be remote. Even if ground water
were to be used on the site in the future, it is likely that the
ground water would be used only after treatment. Thus, this
exposure pathway was not evaluated.
Casual Passerby
A casual passerby was considered for possible exposure to
site related contaminants along the east side of the site
adjacent to Marshall Road, since the existing fence located at
the pi ^erty boundary will be moved' to the west after remedial
action is complete so as to minimize the areas of the site that
will be restricted in that fashion. EPA will not be certain of
precise fence locations until the remedial design phase of the
OU2 remediation. However, a casual passerby will have no actual
exposure after remediation since there is no complete pathway.
If the remote possibility is considered for contact of the
passerby through dermal contact: and incidental ingestion similar
to a trespasser, this would be a conservative assumption.
After remedial action there will be a greenbelt in this area
to camouflage the site from view of the motorists along Marshall
Road. This greenbelt will be enhanced with vegetation consisting
of grass and fast-growing native trees which will nearly
eliminate any contaminants from becoming airborne for contact
with the passerby. When the site is remediated to 5 ppb the
average concentration of dioxin in the area along Marshall Road
will be less than 1 ppb. This is due to the fact that after
grids where dioxin concentrations exceeding 5 ppb are excavated
48
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and replaced with clean backfill material, data indicate that
average dioxin concentrations along Marshall Road will be at or
below 1 ppb because some portions of that area currently have
dioxin concentrations less than 1 ppb. The process of averaging
resulting dioxin concentrations results in a less than 1 ppb
average.
Extremely conservative assumptions were made to calculate
the risk for a casual passerby. Using the most conservative
assumptions possible, the risk posed by the site after
remediation was within EPA's acceptable risk range. Therefore,
the site cleanup to 5 ppb provides for a fully protective remedy.
See memorandum from Ghassan Khoury to Philip Allen in the
Administrative Record.
Current Unprotected Worker
The current unprotected worker was assumed to be exposed to
substances of potential concern through the same exposure routes
as the trespasser: Incidental ingestion of soil, dermal
absorption of soil, dermal absorption from surface water, and
inhalation of airborne soil and vapors. The on-site worker could
also potentially come into contact with all on-site surface
waters, including outfalls, on a regular basis. Contact could
occur during performance of general maintenance activities.
However, because ground water has no current on-site uses, the
current worker has limited potential for contact with ground
water. Thus, the ground water pathway was not evaluated.
Future Unprotected worker
The future unprotected worker was assumed to be exposed to
the substa-oes of potential concern through the same exposure
routes as the current unprotected worker, with the addition of
the ingestion of site ground water. Ground water is currently
not used as a drinking water source for the site, and it is
unlikely that it will be used as such in the future because of
the availability of public water. Conservatively, this pathway
was evaluated, but EPA did not include this exposure route in
developing remediation goals for the site.
A summary of the exposure pathways used for quantitative
evaluation is shown in Figure 10. Models used to calculate
intakes, i.e.. doses of the substances of concern for each
receptor through the various exposure routes are shown in Tables
6, 7, 8, 9, 10, and 11.
6.3.3 Toxicity Assessment
The toxic effects of a chemical generally depend upon the
level of exposure (dose), the route of exposure (oral,
inhalation, dermal), and the duration of exposure (acute,
49
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SOURCE
RELEASE
MECHANISM
SOURCE
RELEASE
MECHANISM
SOURCE
POTENTIAL
EXPOSURE
ROUTE
RECEPTOR
D
SOIL
DUST GENERATION
VOLATILIZATION _
•
•••IB—
AIR
AIR
.1
. •!
. •
VOLATILIZATION _
RUNOFF
RUNOFF^
DRAINAGE
HITCHES
I
DISCHARGE
AIR
~\
1
.1
1
— A
VOLATILIZATION |~~"
f
M
. . .«
c
/ CACHING
• '
— — ™
R°rRy^sB<
1
— ~ DISCHARGE
MB/\I ikinui ATER
QHwUNl/wf A I en
_— '
DISCHARGE
....• DisCHARGE
» AIR
••
WATER
5OLLECTK
SYSTEM'
1
ns*Antnr . Dathuiau 1
—
)N
:
\
J *
L_
INHALATION
INHALATION i
INQESTKDN f
DERMAL
CONTACT
INHALATION
INGESTION [
DERMAL 1
CONTACT 1
INHALATION |
INQES: ION
DERMAL
CONT^'JT
DERK XL
CON"1 «^T
VAP^I
1 INHALATION
IKJ/'ICCTI/'MU
IINUCO I KJN
DERMAL
CONTACT
H
LEGEND:
X
• tXpUSUI* p»Mi"-7 --
I cannot be completed
U Exposure route is highly unlikely
NOTES: '-
'»• uncertain
r
JL
1 x
1 x
1 x
1 o
1 u
1 u
1 o
\ u
\ x
1 '
\ '
] '
II
II
II
II
II
II
II
II
II
II
II
II
x
x
x
o
u
X
o
u
X
s
1
1
1 x
1 x
1 x
1 o
1 u
II x
II o
II u
II x
II s
II o
II x
HERCVERM-l/X.OAHOMBDMVCvRSKQRP
CONCEPTUAL MODEL OF POTENTIAL EXPOSURE ROUTES
-------
Model for Calculating Doses through the
Incidental Ingestion of Soil
Soil Ingestion Dose CS * SIR * EF * ED
(mg/kg-day) = BW AT
Where:
CS = Chemical concentration in surface soil (mg/kg)
CTr* -• Soil ingestion rat*1 (kg/day)
EF = Exposure frequency (days/year)
ED = Exposure duration (years)
BW = Body weight (kg)
AT = Averaging time (days)
Exposure Assumptions
All Scenarios:
CS = Surface soil exposure concentrations
Trespasser:
SIR = 5.0E-05 kg/day (U.S. EPA, 1994a)
EF = 1 day/week, 26 weeks/year
ED = 5 years
BW = 56 kg, average weight of a 12-to 18-year old (U.S. EPA, 1989a)
AT = 365 days/year x 5 years (for evaluating noncancer risk)
= 365 days/year x 70 years (for evaluating cancer risk)
Worker (Current and Future):
SIR = 5.0E-05 kg/day (U.S. EPA, 1991)
EF = 250 days/year (U.S. EPA, 1991)
ED = 25 years (U.S. EPA, 1991)
BW = 70 kg (U.S. EPA, 1991)
AT = 365 days/year x 25 years (for evaluating noncancer risk)
= 365 days/year x 70 years (for evaluating cancer risk)
TABLE 6
-------
Model for Calculating Doses through
Dermal Absorption from Soil
Soil Dermal Absorption Dose CS * SA * AF ' ABS (or RABS1 * EF * ED
(mg/kg-day) = BW AT
Where:
CS = Chemical concentration in surface soil (rag/kg)
SA = Skin surface area available for contact (cm2/day)
AF = Sr»il-to-skin adherence factor (kg/err2)
ABS = Absorption factor (unitless)
RABS = Relative dermal absorption factor (unitless)
EF = Exposure frequency (days/year)
ED = Exposure duration (years)
BW = Body weight (kg)
AT = Averaging time (days)
Exposure Assumptions
All Sec nos:
CS = Surface soil exposure concentrations
AF = l.OOE-06 kg/cm2, reasonable upper limit of soil adherence factor (U.S.
EPA, 1992a)
ABS = 0.03 for dioxin (U.S. EPA, 1992a)
RABS = 0.50 for all chemicals except dioxin, based on guidance in U.S. EPA, 1989c
Trespasser.
SA = 1,950 cm2/day, based on the average arm and hand surface area of a 12- to
18-year old (U.S. EPA, 1989a)
EF =1 day/week, 26 weeks/year
ED = 5 years
BW = 56 kg, average weight of a 12- to 18-year old (EPA, 1989a)
AT = 365 days/year x 5 years (for evaluating noncancer risk)
= 365 days/year x 70 years (for evaluating cancer risk)
TABLE 7
-------
Model for Calculating Doses through
Dermal Absorption from Soil
(continued)
Worker (Current and Future):
SA = 2,000 cm2/day, based on the average arm and hand surface area of adult
males (U.S. EPA, 1989a)
EF = 250 days/year (U.S. EPA, 1991)
ED =25 years (U.S. EPA, 1991)
BW = 70 kg (U.S. EPA, 1991)
AT = 365 days/year x 25 years (for evaluating noncancer risk)
= 365 days/year x 70 years (for evaluating cancer risk)
TABLE 7 (cent)
-------
Model for Calculating Doses through the
Inhalation of Airborne Soil
Soil Inhalation Dose CS * RD * IV ' EF * ED
(mg/kg-day) = BW * AT
Where:
CS = Chemical concentration in surface soil (mg/kg)
RD = Respirable-size soil particle concentration in air (i.e., PM10) (kg/m3)
IV = Inhalation volume (m3/day)
EF = Exposure frequency (days/year)
ED = Exposure duration (years)
BW = Body weight (kg)
AT = Averaging time (days)
Exposure Assumptions
All Scenarios:
CS = Surface soil exposure concentrations
RD = 3.1E-C8 kg/m3 (URS, 1990)
Trespasser.
IV = 2.5 m3/day, based on 1 hour of moderate activity on the site (U.S. EPA,
1989a)
EF = 1 day/week, 26 weeks/year
ED = 5 years
BW = 56 kg, average weight of a 12- to 18-year old (U.S. EPA, 1989a)
AT = 365 days/year x 5 years (for evaluating noncancer risk)
= 365 days/year x 70 years (for evaluating cancer risk)
TABLE 8
-------
Model for Calculating Doses through the
Inhalation of Airborne Soil
(continued)
Worker (Current and Future):
IV =20 m3/day (U.S. EPA, 1991)
EF = 250 days/year (U.S. EPA, 1991)
ED = 25 years (U.S. EPA, 1991)
BW = 70 kg (U.S. EPA, 1991)
AT = 365 days/year x 25 years (for evaluating noncancer risk)
= 365 days/year x 70 years (for evaluating cancer risk)
TABLE 8 (cent)
-------
Model for Calculating Doses through the
Inhalation of Vapors
Vapor Inhalation Dose CA * IV * EF * ED
(mg/kg-day) = B W* AT
Where:
CA = Chemical vapor concentration in air (mg/m3)
TV = Inhalation volume (m3/day)
EF = Exposure Frequency (days/year)
ED - Exposure duration (years)
BW = Body weight (kg)
Af = Averaging time (days)
Exposure Assumptions
All Scenarios:
CA = Vapor concentrations
Trespasser
IV = 2.5 m3/day, based on 1 hour of moderate activity on the site (U.S. EPA,
1989a)
EF = 1 day/week, 26 weeks/year
ED = 5 years
BW = 56 kg, average weight of a 12- to 18-year old (U.S. EPA, 1989a)
AT = 365 days/year x 5 years (for evaluating noncancer risk)
= 365 days/year x 70 years (for evaluating cancer risk)
Worker (Current and Future):
IV = 20 m3/day (U.S. EPA, 1991)
EF = 250 days/year (U.S. EPA, 1991)
ED = 25 years (U.S. EPA, 1991)
BW = 70 kg (U.S. EPA, 1991)
AT = 365 days/year x 25 years (for evaluating noncancer risk)
= 365 days/year x 70 years (for evaluating cancer risk)
TABLE 9
-------
Model for Calculating Doses through
Dermal Absorption from Surface Water
Surface Water
Dermal Absorption Dose = CSW * CF-1 * SA * PC * ET ' CF-2 * EF * ED
(mg/kg-day) BW • AT
Where:
CSW = Chemical concentration in surface water (mg/L)
CF-1 = Conversion factor (mg//^g)
SA = Skin surface ar^a available for con*r ~t (cm2)
PC = Dermal permeability coefficient (cm/hour)
ET = Exposure time (hours/day)
CF-2 = Conversion factor (L/cm3)
EF = Exposure frequency (days/year)
ED = Exposure duration (years)
BW = Body weight (kg)
AT = Averaging time (days)
Exposure Assumptions
All Scenarios:
CF-1 = Img/l.OOO/ig
PC = Permeability coefficient.
CF-2 = lL/l,OOOcm3
Trespasser:
CSW = Surface water exposure concentrations for Rocky Branch Creek, presented
in Table 3-2
SA = 1,970 cm2, average hand and foot surface area of a 12- to 18-year old (U.S.
EPA, 1989a)
ET = 1 hour/day
EF = 1 day/week, 13 weeks/year
ED = 5 years
BW = 56 kg, average weight of a 12- to 18-year old (U.S. EPA, 1989a)
AT = 365 days/year x 5 years (for evaluating noncancer risk)
= 365 days/year x 70 years (for evaluating cancer risk)
TABLE 10
-------
Model for Calculating Doses through
Dermal Absorption from Surface Water
(continued)
Worker (Current and Future):
CSW = Surface water exposure concentrations based on all surface waters,
presented in Table 3-2
SA =840 cm2, average hand surface area of an adult (U.S. EPA, 1989a)
ET =1 hour/day
EF = 1 day/week, 50 weeks/year (U.S FPA, 19°^
ED = 25 years (U.S. EPA, 1991)
BW = 70 kg (U.S. EPA, 1991)
AT = 365 days/year x 25 years (for evaluating noncancer risk)
= 365 days/year x 70 years (for evaluating cancer risk)
TABLE 10 (cont)
-------
Model for Calculating Doses through the
Ingestion of Groundwater
G-oundwater Ingestion Dose CGW * GIR * EF * ED
(mg/kg-day) = BW * AT
Where:
CGW = Chemical concentration in groundwater (mg/L)
C "c = Groundwater ingestion rate (L/day)
EF = Exposure frequency (days/year)
ED = Exposure duration (years)
BW = Body weight (kg)
AT = Averaging time (days)
Exposure Assumptions
Worker (Future):
CW = Groundwater exposure concentrations
IR = 1 L/day (U.S. EPA, 1991)
EF = 250 days/year (U.S. EPA, 199n
ED = 25 years (U.S. EPA, 1991)
BW = 70 kg (U.S. EPA, 1991)
AT = 365 days/year x 25 years (for evaluating noncancer risk)
= 365 days/year x 70 years (for evaluating cancer risk)
TABLE 11
-------
chronic, subchronic, or lifetime). Thus, a full description of
the toxic effects of a chemical includes a listing of what
adverse health effects the chemical may cause (carcinogenic and
noncarcinogenic), and how the occurrence of these effects depends
upon dose, route, and duration of exposure.
Slope factors (SF's) have been developed by EPA for
estimating excess lifetime cancer risks associated with exposure
to potentially carcinogenic contaminants of concern. SF's, which
are expressed in units of (mg/kg-day)'1, are multiplied by the
estimated intake of potential carcinogen, in mg/kg-day, to
provide an upper-bound estimate of the e^^ess 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 unlikely. Slope
factors are derived from the results of human epidemiological
studies or chronic animal bioassays *-o which animal-to-human
extrapolation and uncertainty factors have been applied.
References doses (RfD's) have been developed by EPA for
indicating the potential for adverse health effects from exposure
to contaminants of concern exhibiting non-carcinogenic adverse
health effects. RfD's which are expressed in units of mg/kg-day,
are estimates of daily (maximum) exposure levels for the human
population, including sensitive subpopulations. Estimated
intakes of contaminants of concern from environmental media
(e.g.. the amount of chemical ingested from drinking contaminated
ground water) can be compared to the RfD. RfD's are derived from
human epidemiological studies or animal studies to which
uncertainty factors have been applied to account for the use of
animal data to predict effects on humans.
loxicity information used to calculate the risk for
carcinogenic risk including the slope factor, the weight of
evidence, and source of the toxicity information can be found in
Tables 12 and 13. Chronic and subchronic references doses used
in the toxicity assessment can be found in Tables 14 and 15.
In numerous public forums over the past year, EPA has
summarized the preliminary results from the dioxin reassessment
study in order to accept public comment during the scientific
peer review process. One of the major conclusions was that the
"weight-of-evidence" suggested that dioxin, furans, and dioxin
like compounds are likely to present a cancer hazard to humans,
and that a risk specific dose of dioxin at 0.01 pico grams (pg)
TEQ per kilogram (kg) of body weight per day, resulted in one
additional cancer in one million. This risk specific dose
estimate represents a plausible upper bound on risk based on the
evaluation of both animal and human data. With regards to
average intake, humans are currently exposed to background levels
60
-------
U.S. EPA and IARC Categorizations of the Carcinogenic
Substances of Potential Concern
Substance
Organics
Chloroform
Methylene chloride
2,3,7,8-TCDD
2,4,6-Trichlorophenol
EPA
Carcinogenirity
Category*'1'
IARC
Carcinogenicity
Category0-"
B2
C
B2
B2
2B
2B
2B
NC
Inorganics
Arsenic
Lead
A
B2
1
2B
•References: IRIS, 1995; U.S. EPA, 1994b
"Category definitions (U.S. EPA, 1986b):
A = Human carcinogen (sufficient evidence from epidemiologic studies).
62 = Probable human carcinogen (sufficient evidence from animal studies and inadequate or no human
dataV
C = Pos&iole human carcinogen (limited evidence from animal studies and no iiuman data)
'Reference: WHO, 1987
"Category definition (WHO, 1987):
1 = Human carcinogen (sufficient evidence of carcinogenicity in humans).
2B = Possible human carcinogen (limited evidence of carcinogenicity in humans in the absence of
sufficient evidence of carcinogenicity in experimental animalyt inadequate evidence of carcinogenicity
in humans or no human data and sufficient evidence of carcinogenicity in experimental animals; or
inadequate evidence of carcinogenicity or no data in humans and limited evidence of carcinogenicity
in experimental animals with supporting evidence from other relevant data).
NC = Not categorized.
TABLE 12
-------
Cancer Slope Factors
Substance
Organic*
Chloroform
Methylens chloride
23,7,»-TCDD
2,4,6-
Trichlorophenol
Inhalation
Slope Factor
(mg/kg-day)-1
NC
NC
L5E+05
9.7E+03
1.1E-02"
Reference
or Basis
—
—
VS. EPA,
1994b
OSF
IRIS, 1995
Oral Slope
Factor
(mg/kg-day)-1
Reference
or Basis
6.1E-03
7J5E-03
UE+05
9.7i- M)3
1.1E-02
IRIS, 1995
IRIS, 1995
U.S. EPA,
1994b
ChemRisk,
1990
IRIS, 1995
Dermal Slope
Factor*
(mg/kg-day)-1
NC
NC
3.0E+05
1.9E+04
2.2E-02
Inorganics
Arsenic
Lead
NC
NC
—
—
USE+OO"
NTV
IRIS, 1995
-
NC
NC
'Dermal slope factors were derived from the oral slope factors as described in Subsection 3323.
"Derived from a unit risk, assuming the inhalation of 20 m3 of air per day and a body weight of 70 kg (U.S. EPA,
1994b).
""Derived from a unit risk, assuming the consumption of 2 liters of water per day and a body weight of 70 kg
(U.S. EPA, 1994b).
NC = S bstance is not of concern through this exposure route.
NTV = A toxitity value was not available.
OSF = Oral slope factor was used (Subsection 33.2.2).
TABLE 13
-------
Chronic Reference Doses (RfDs)
w
I—'
p-
Organic*
Acetone
.,
Chloroform
"•
2-Chlorophenol
4-Chlorophenol
^M*^™"!"™"^"1^^^"*^™l—*^^
2,4-D
—.. ""
2,6-D
^••^«-^-»-
2,4-Oichlorophenyl
2.6-Dichlorophenyl
—^^^—^•~"1
Methylene chloride
_»————
Phtnol
•ii —
Silver
•n ••
2,4,5-T^
^—•- -
2,4,6-T
2,3,7,8-TCDD
Tetrachlorobenzene
. ^~~~~"
Toluene
•
2.3.6-Trichlorophenol_
Reference
or Basis
OralRfD
(mg,'kg-day)
Reference
or Basis
Dermal RfD*
(mg/kg-day)
NC
„ —
NC
_—
5.0E-03
— ,
NC
— . •
l.OE-02
. • — • —
NC
3.0E-03
__ . — .
3.0E-03
_ 1 •
NC
NC
___ • •
8.0E-03
.
l.OE-02
— • •
NC
__
NTV
. — .
3.00E-04"
— . •
NC
NC
—
—
ORD
—
ORD
—
ORD
ORD
—
ORD
ORD
ORD
—
l.OE-01
l.OE-02
5.0E-03
5.0E-03
l.OE-02
l.OE-02
3.0E-03
3.0E-03
6.0E-02
6.0E-01
8.0E-03
l.OE-02
l.OE-02
NTV
3.0E-04C
2.0E-01
l.OE-01
IRIS, 1995
IRIS, 1995
IRIS, 1995
Isosncr
IRIS, 1995
Isomer
IRIS, 1995
Isomer
IRIS, 1995
IRIS, 1995
IRIS, 1995
IRIS, 1995
Isomer
• —
IRIS, 1995
IRIS, 1995
Isomer
NC
NC
4.5E-03 (dw)
4.5E-03 (dw)
5.0E-03 (d)
5.0F-03(d)
2.7E-03 (dw)
2.7E-03 (dw)
NC
5.4E-01 (g)
4.0E-03 (d)
5.0E-03 (d)
5.0E-03(d) |
NTV 1
NC 1
1.8E-01 (g) 1
5.0E-02 (d) 1
-------
Chronic Reference Doses (RfDs)
(continued)
r1
w
o
o
0
Substance
Oryanics (continued)
2.4,5-Trichlorophenol
2,4,6-Trichlorophenol
Inorganics
Antimony
Arsenic
Chromium
Copper
Lead
Mercury
Nickel
Silver
Thallium
Zinc
•Chronic dermal RfDs were
in the studies on which the
d = diet
dw = drinking water
lation RfD
5/kg-day)
L.OE-01
L.OE-01
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
Reference
or Basis
ORD
ORD
Oral RfD
(mg/kg-day)
l.OE-01
l.OE-01
Reference
or Basis
IRIS, 1995
Isomer
Dermal RfD'
'mg/kg-day)
5.0E-02 (d)
5.0E-02 (d)
—
—
—
—
—
—
—
—
—
—
4.0E-04
3.0E-04
5.0E-03"
3.7E-02'
NTV
3.0E-04
2.0E-02
5.0E-03
NTV
3.0E-01
IRIS, 1995
IRIS, 1995
IRIS, 1995
U.S. EPA, 1994b
—
U.S. EPA, 1994b
IRIS, 1995
IRIS, 1995
—
IRIS, 1995
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
chronic oral RfDs as described in Subsection 3.3.3.3. The route by which the chemical was administered
is indicated in parentheses as follows:
bot
-------
Subchronic Reference Doses (RfDs)
r1
M
Inhalation RfD
(mg/kg-day)
Reference
or Basis
Oral RfD
(mg/kg-day)
Reference
or Basis
Dermal RfD*
(mg/kg-day)
NC
NC
5.0E-02
5.0E-02(D)
l.OE-02
l.OE-02
3.0E-03
3.0E-03
NC
6.0E-01(D)
8.0E-03
l.OE-01
l.OE-01
NTV
NC
2.0E + 00(D)
l.OE + 00
U.S. EPA, 1994b
Isomer
U.S. EPA, 1994b
Isomer
' I.S. EPA, 1994b
Isomer
U.S. EPA, 1994b
U.S. EPA, 1994b
U.S. EPA, 1994b
Isomer
U.S. EPA, 1994b
Isomer
NC
NC
4.5E-02 (dw)
4.5E-02 (dw)
5.0E-03 (d)
5.0E-03(d)
2.7E-03 (dw)
2.7E-03 (dw)
NC
5.4E-01 (g)
4.0E-03 (d)
5.0E-02 (d)
5.0E-02(d)
NTV
NC
1.8E + 00 (g)
5.0E-01(d)
-------
Subchronic Reference Doses (RfDs)
(continued)
r4
w
n
o
Substance
d
dw
g
(D)
NC
NTV
ORD
Inhalation RfD
(mg/kg-day)
Reference
or Basis
Oral RfD Reference
(mg/kg-day) or Basis
Dermal RfD*
(mg/kg-day)
ORD
ORD
l.OE+00
l.OE+00
U.S. EPA, 1994b
Isomer
5.0E-01 (d)
5.0E-01 (d)
calculated from the subchronic oral RfDs as described in Subsection 3.3.3.3. The route by which the chemical
which the oral RfD was based is indicated in parentheses as follows:
was
= diet
= drinking water
= gavage
TheTubstance is not of concern for the trespasser scenano throug- the oral route.
TteS«l RfD was used only to calculate the dermal RfD.
The chemical is not a substance of potential concern through this exposure route.
A toxicity value was not available.
The subchronic oral RfD was used.
-------
of dioxin-like compounds on the order of 3-6 TEQ's pg/kg/day.
Therefore, plausible upper-bound risk estimates for general
population exposures to dioxin and related compounds (at
background levels) may be as high as 1 in 10,000 (1X10"*) to 1 in
1,000 (1X10"3) . High end estimates of body burden of individuals
in the general population (approximately the top 10% of the
general population) may be greater than 3 times higher.
What should also be noted here is that the risk calculations
presented in the baseline risk assessment (and reported in this
summary) for dioxin are based on exposure to 2,3,7,8-TCDD only.
Additional sampling performed by +. ve PRP at the request of EPA
shows that other dioxin and furan compounds are present at the
site, and could contribute to approximately 20 percent greater
risk than TCDD alone, i.e.. the risk estimates presented could be
adjusted upward by 20 percent.
It is also important to note that the non-cancer risks
outlined in the baseline risk assessment and summarized here do
not address the non-cancer risks associated with low level
exposures to dioxin. As a result, the baseline risk assessment
may underestimate the non-cancer risk associated with exposure to
site contaminants. The reason being is that a reference dose
(RfD) (the daily intake of a chemical to which an individual can
be exposed without experiencing non-cancer health effects) has
not been established by EPA for dioxin at this time. If a
reference dose were to be calculated for dioxin based on human
and animal data, it could result in an acceptable intake level
for humans below the current level of daily intake in the general
population. EPA's dioxin reassessment study has suggested that
at some dose, and possibly within one order of magnitude of
average background body burdens, dioxin exposure can result in
noncancer health effects in humans. These effects include
developmental and reproductive effects, immune suppression, and
disruption of regulatory hormones.
6.3.4 Risk Characterisation
Cancer Risk
The risk of getting cancer from exposure to a chemical is
described in terms of probability that an individual exposed for
his or her entire lifetime will develop cancer by the age 70.
For carcinogens, risks are estimated as the incremental
probability of an individual developing cancer over a life-time
as a result of exposure to the carcinogen. Excess life-time
cancer risk is calculated using the following equation:
67
-------
Cancer Lifetime Cancer
Risk = Averaged x Slope
Dose Factor
(mg/kg-day) (mg/kg-day)'1
These risks are probabilities that are generally expressed
in scientific notation (e.g. , 1 x 10"6 or IE"6) . An excess
lifetime cancer risk of 1 x 10"45 indicates that, as a reasonable
maximum estimate, and individual has a 1 in 1,000,000 chance of
developing cancer as a result of site related exposure to a
carcinogen over a 70-year lifetime under the specific exposure
conditions at a site.
Tables 16, 17, and 18 summarize the potential lifetime
cancer risk for the three exposure scenarios examined in the risk
assessment.
The calculated excess lifetime cancer risk for the
trespasser scenario was 8X10'5 or approximately 8 in 100,000. The
exposure routes that posed the majority of the risk to the
trespasser were through dermal absorption from surface water,
incidental soil ingestion, and dermal contact with soil. TCDD
dioxin was the only contaminant that contributed to an excess
cancer risk greater that 1X10"6.
The calculated excess lifetime cancer risk for the current
unprotected worker scenario based on all exposure routes was
approximately l in 1,000 or 1X10'3. This risk exceeds EPA's
acceptable risk range. The exposure routes that posed the
majority of the risk to the current unprotected worker were
through dermal contact with soil (6X10"*), dermal contact with
surface waters (5X10"*), and incidental soil ingestion (2X10"*) .
T^ calculated excess lifetime cancer risk for the future
unprotected worker scenario based on all exposure routes was
approximately 5 in 100 or 5X10'2. This risk exceeds EPA's
acceptable risk range. The exposure routes that posed the
majority of the risk to the future unprotected worker were
through soil ingestion (2X10"*) , dermal contact with soil (6X10"*) ,
dermal contact with surface water (5X10"*), and ground water
ingestion (5X10'2) .
Over 99 percent of the calculated risk for all exposure
scenarios was contributed by 2,3,7,8-TCDD. As mentioned earlier,
when all dioxin and furan congeners are factored into the risk
estimates, those estimates may be 20 percent higher.
Non—cancer Risk
The potential for non-carcinogenic effects is evaluated by
comparing an exposure level over a specified time period (e.g.,,
68
-------
OTEMTIAL LIFETIME CANCER RISK
TRESPASSER
-3
>
33
71
SUBSTANCE
2^8-TCb& (U.S. EPA)
(Ch«mRI«h)
2,4,6-Trlchloroph»nol
TOTAL (U.S. EPA)
TOTAL (Ch»mRi8kl
SOIL
INGESTION
4.05E-07
1.70E-10
6.27E-06
4.06E-07
DERMAL
ABSORPTION
FROM SOIL
9.29E-07
3.31E-09
1.47E-05
9.32E-07
SOIL
INHALATION
6.28E-10
2.63E-13
9.72E-09
6.29E-10
VAPOR
INHALATION
1.94E-10
1.26E-11
2.50E-14
1.94E-10
1.26E-H
DERMAL |
ABSORPTION
FROM SURFACE
WATER
4.05E-06
4.41E-10
6.39E-05
4.05E 06
TOTAL
8.48E-05
5.38E-06
3.92E-09
TOTAL LIFETIME
CANCEF RlŁ (U.S EPA) 8.49E-05
TOTAL LIFETIME
CANCER RISK (CtwmRltk) 5 39E-06
-------
POTENTIAL LIFETIME CANCER RISK
CURRENT UNPROTECTED WORKER
H
r>
B
f
w
SUBSTANCE
_. — =
2,3.7.8-TCDD (U.S. EPA)
//•'fc.mmQlakl
^Cn9ninl«A;
2,4,6-Trlchloroph«nol
TOTAL (U.S. EPA)
rnTAL (Ch«mRI«Kl _
i •» -^-^— ^•"^'•^
SOIL
INGESTION
..
2.41E-04
1.56E-05
6.53E-09
2.41 E-04
V56E-05
DERMAL
ABSORPTION
FROM SOIL
5.79E-04
3.67E-05
1.31E-07
5.79E-04
3.68E-0C
1 — '
-J
SOIL
INHALATION
2.99E-06
1.93E-07
8.10E-11
2.99E-06
1.93E-07
VAPOR
INHALATION
5.98E-08
3.86E-09
7.69E-12
5.98E-08
3.87E-09
DERMAL
ABSORPTION
FROM SURFACE
WATER
4.68E-04
2.97E-05
1.14E-06
4.70E-04
3.08E-05
TOTAL
1.29E-03
8.21E-05
1.28E-06
TOTAL LIFETIME
CANCEP RISK (U.S. EPA) 1.29E-03
TOTAL LIFE! ^E
CANCER RISK (CtomFUtk) B.34E-05
-------
POTENTIAL LIFETIME CANCER RISK
FUTURE UNPROTECTED WORKER
H
Ł
t-<
w
00
SUBSTANCE
Chloroform
Methytone eWorld*
2,3.7,8-TCDD (U.S. EPA)
(Ch*mRlsk)
2.4.6-Trichloroph*nol
Arsenic
Lead
TOTAL (U.S. EPA)
SOIL
INGESTION
NA
NA
2.41E-04
1.56E-05
6.53E-09
NA
NA
2.41E-04
ERMAL
ORPTION
3M SOIL
NA
NA
5.79E-04
3.67E-05
1.31E-07
NA
NA
5.79E-04
3.68E-05
SOIL
INHALATION
NA
NA
2.99E-06
1.93E-07
8.10E-11
NA
NA
2.99E-06
1.93E-07
VAPOR
INHALATION
NA
NA
598E-08
3.86E-09
7.69E-12
NA
NA
5.98E-08
3.87E-09
DERMAL
ABSORPTION
FROM SURFACE
WATER
NA
NA
4.68E-04
2.97E-05
1.14E-06
NA
N'
4.70E-04
3.08E-05
GROUNDWATER
INGESTION
1.51E-07
3.41E-07
5. QBE -02
3.29E-03
3.81E-04
3.42E-05
N1V
5.13E-02
3.70E-03
TOTAL
1.51E-07
3.41E-07
5.21E-02
3.37E-03
3.82E-04
3.42E-05
NTV
TOTAL LIFETIME
CANCER RISK (U.S. EPA) 5.26E-02
TOTAL LIFETIME
CANCER RISK (ChemRlsk) 3. 79E - 03
NA - Not applicable. Ch*mlcal is not of concern through this exposure rout*.
NTV~- Not calculated because a slope factor was not available.
-------
life-time) with a reference dose derived for a similar exposure
period. The ratio of exposure to toxicity is called the hazard
quotient. By adding the hazard quotients for all contaminants of
concern which affect the same target organ (e.g.. the liver)
within a medium or across all media to which a population may
reasonably be exposed, the Hazard Index (HI) can be generated.
In general, a total hazard index of 1 is used as a benchmark of
potential concern for non-cancer health effects.
Hazard Daily Reference
Quotient = Intake -5- Dose
Tables 19, 20, and 21 summarize the hazard quotients and indices
calculated for the same potentially exposed individuals.
The total hazard index calculated for contaminants of
concern other than dioxin for a trespasser was approximately 0.4,
based on soil ingestion, soil inhalation, dermal contact with
soil, and dermal contact with surface water. Again, the
benchmark of concern for non-cancer health effects is 1. A total
hazard index of approximately 4 was calculated for the current
unprotected worker with dermal contact with 2,4-D contributing
most of the risk. For the future unprotected worker a hazard
index of 5,520 was calculated. The ground water ingestion
pathway contributed most to the non-cancer risk for the future
unprotected worker. Again, for this ROD EPA did not consider the
ground water ingestion exposure route in developing thfi
remediation goals for this site, because drinking water for the
Jacksonville area is provided from sources near Little Rock, and
it is doubtful that any wells on this property will ever be used
for domestic purposes.
6.3.5 Uncertainty Analysis
Within the Superfund process, baseline risk assessments are
developed to provide risk managers a numerical representation of
the se/erity of contamination present at a 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 process. Some of these uncertainties may
lend in the under estimation of site risk others in its
overestimation.
Factors that Tend to Underestimate Exposure/Risk
• Lack of RfD's or SF's for all chemicals of concern;
• Nonquantification of some exposure pathways;
• Exclusion of chemicals present but not detected;
72
-------
HAZARD QUOTIENTS AND INDICES
TRESPASSER
W
Ł
SUBSTANCE
*-v-..ioroph«nc
4-ChlofOph«nol
2.4-D
2.8-D
2.4-Dichlofoph«nol
2,6-Dichloroph«nol
Phenol
Silvex
2,4.5-T
2.4,6-T
2,3.7.8-TCDD
Tetrachlorobenzant
Toluene
2,3.6-Trlchloropheiol
2'4 5_Trlchlorophenol
2'.4,6-Trlchlorophenol
SOIL
GESTION
4.96E-07
NA
1.97E-02
NA
1.06E-04
1.40E-05
NA
8.75E-04
1.59E-04
NA
NTV
NA
NA
NA
.91E-07
2.16E-07
209E-02
DERMAL
ABSORPTION
FROM SOIL
9.67E-06
NA
3.84E-01
NA
2.07E-03
2.73E-04
NA
1.71E-02
3.10E-03
NA
NTV
NA
NA
NA
3.72E-06
4.22E-06
4.07E-01
SOIL
INHALATION
7.69E-10
NA
3.06E-05
NA
1.64E-07
2.17E-08
NA
1.36E-06
2.46E-07
NA
NTV
NA
NA
NA
2.96E-10
3.35E-10
3.23E-05
VAPOR
INHALATION
1.34E-10
NA
NC
NA
3.60E-08
6.04E-09
NA
5.96E-09
3.18E-09
NA
NTV
NA
NA
NA
5.09E-10
3.18E-11
5.19E-08
DERMAL
ABSORPTION
FROM SURFACE
WATER
2.02 E'- 06
1.80E-05
2.75E-04
8.6BE-05
3.62E-04
2.22E-05
4.38E-08
9.96E-05
2.76E-05
< 55E-05
NTV
NA
5.01E-07
2.85E-07
1.58E-06
5.62E-07
9.10E-04
==ir_.. .
HAZARD INDEX
(BY
SUBSTANCE)
1.22E-05
1.60E-05
4.04E-01
8.68E-05
2.54E-03
3.09E-04
4.38E-08
1.80E-02
3.29E-03
1.55E-05
NTV
NA
5.01 E- 07
2.85E-07
5.49E-06
5.00E-06
TOTAL HAZARD INDEX 4.29E - 01
^u mi«.ii» not of concern through thle«xpo»u» route.
NA - Not applicable. Chwnh»l I» "« eonc.n,rat|on could not b. dstormlmd (APP.ndlx E).
-------
HAZARD QUOTIENTS AND INDICES
CURRENT UNPROTECTED WORKER
r1
w
SUBSTANCE
2-Chlorophenol
4-Chloropheno)
2.4-0
2 fl-D
2.4-Dichlorophenol
2.6-Dichlofophenol
Phanol
Sllvex
245-T
2.4,6-T
2.3.7.8-TCDD
Tetrachlorobenzene
2.3.6-Trlchlorophenol
2,4,5-Trlchlorophenol
2,4,6-Trlchlorophenol
, ..-r.nn IMPIFV (BY FXPOSURE ROUTE)
SOIL
INGESTION
3.82E-05
NA
1.52E-01
NA
8 15E-04
1.08E-04
NA
F 73E-03
i.2: E-02
NM
NTV
Nf
N/
NA
1 47E-05
1.66E-05
1.72E-01
DERMAL
ABSORPTION
FROM SOIL
7.63E-04
3.03E+00
NA
1.63E-02
2.15E-03
NA
1.35E-01
2.45E-01
NA
NTV
NA
NA
NA
2.94E-04
3.33E-04
3.43E+00
SOIL
INHALATION
4.73E-07
NA
1.88E-03
NA
1.01E-05
1.33E-06
NA
8.34t-05
1.52E-04
NA
NTV
NA
NA
NA
1.82E-07
2.06E-07
2.13E-03
VAPOR
INHALATION
8.22E-08
NA
NC
NA
2.22E-06
1.72E-07
NA
3.67E 07
1.96E-06
NA
NTV
NA
NA
NA
3.13E-07
1.96E-08
5.33E-06
DERMAL
ABSORPTION
FROM SURFACE
WATER
5.06E-03
1.16E-01
4.72E-02
1.50E-02
2.48E-01
3.09E-03
1.55E-CJ,
1.20E-C&
3.98E-02
7.99E-CC
NTV
NA
1.SOE-03
2.24E-05
8.81 E-03
2.91E-03
5.79E-01
HAZARD INDEX
(BY
SUBSTANCE)
5.86E-03
1.16E-01
3.23E+00
1 50E-02
2.66E-01
5.35E-03
1.55E-05
1 53d -01
2.97E-01
7.99E-02
NTV
NA
1 60E-03
2.24E-05
8.92E-03
3.26E-03
TOTAL HAZARD INDEX 4.19E+00
NA - Not applicable. Chemical is not of concern through this exposure route.
NC - Not calculated because an exposure concentration could n<.. br determined (Appendix E).
NTV - Not calculated because an RfD was not available.
-------
HAZARD QUOTIENTS AND INDICES
FUTURE UNPROTECTED WORKER
H
is
CD
r1
w
ho
>__l
SUBSTANCE
— — ! —
Acetone
Chloroform
2-Chlorophenol
4-CWorophenol
2.4-D
2,6-D
2,4-Dtehlorophenol
2,6-Dlchlorophenol
Methylene chloride
Phenol
SHvex
2,4,5-T
2,4,6-T
2,3,7.8-TCDD
Tefrachlorobenzene
Toluene
2 3 8-Trlchlorophenol
2 4,5-Trlchlorophenol
2,4,6-TrlcWorophenol
Antimony
Arsenic
Chromium
Copper
Lead
Mercury
.Nickel
Silver
Thallium
Zinc
. r-x/nstd IDC Qrtl JTE
^TftnnjMpnf (RY CVPQSURE ROUI ti
SOIL
INGESTION
^^-Des^raa^ttffi^
NA
NA
3.82E-05
NA
1.52E-01
NA
8.15E-04
1.08E-04
NA
NA
6.73E-03
1.22E-02
NA
NTV
NA
NA
NA
1.47E-05
1.66E-05
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
1.72E-01
DERMAL
ABSORPTION
FROM SOIL
NA
NA
7.63E-04
NA
3.03E+00
NA
1.63E-02
2.15E-03
NA
NA
1.35E-01
2.45E-01
NA
NTV
NA
NA
NA
2.94E-04
3.33E-04
NA
LA
NA
NA
NA
NA
NA
NA
NA
NA
3.43E+00
SOIL
INHALATION
NA
NA
4.73E-07
NA
1.88E-03
NA
1.01E-05
1.33E-06
NA
NA
8.34E-05
1.52E-04
NA
NTV
NA
NA
NA
1.82E-07
2.06E-07
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
2.13E-03
VAPOR
INHALATION
NA
NA
8.22E-08
NA
NC
NA
2.22E-06
3.72E-07
NA
NA
3.67E-07
1.96E-06
NA
NTV
NA
NA
NA
3.13E-07
1.96E-08
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
5.33E-06
DERMAL
ABSORPTION
FROM SURFACF
WATER
NA
NA
5.06E-03
1.16E-01
4.72E-02
1.50E-02
2.48E-01
3.09E-03
NA
1.55E-05
1.20E-02
3.98E-02
7.99E-02
NTV
NA
1.60E-03
2.24E-05
8.61E-03
2.91E-03
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
.79E-01
GROUNDWATER
INGESTION
1.57E-03
6.95E-03
3.13E+01
1.19E+02
1.57E+03
1.08E+03
1.89E+03
8.15E+01
2.12E-03
1.24E-01
1.35E+02
3.72E+02
i-OSE+02
NTV
3.26E+00
2.I5E+01
9. JOE -03
1.27E+01
9.69E-01
7.09E-01
1.83E-01
1.08E-02
3.70E-03
NTV
1.01E-02
2.40E-02
1.17E-02
NTV
2.05E-03
5.52E+03
HAZARD INDEX
(BY
SUBSTANCE)
1.57E-03
6.95E-03
3.13E+01
1.19E+02
1.57E+03
1 08E+03
1.89E+03
8.15E+01
2.12E-03
1.24E-01
1.35E + 02
3.72E+02
2.06E+02
NTV
3.26E+00
2.15E+01
9.32E-03
1.27E+01
9.72E-01
7.09E-01
1.83E-01
1.08E-02
3.70E-03
NTV
1.01E-02
2.40E-02
1.17E-02
NTV
2.05E-03
TOTA •_ HAZARD INDEX 5.52E + 03
NA - Not applicable. Chemical is not of concern through this exposure route.
NC - Not calculated because an exposure concentration could not be determined (Appendix E).
NTV - Not calculated because an RtD value was not available.
-------
Factors that Tend to Overestimate Exposure/Risk;
• Use of conservative exposure assumptions;
• Use of conservative RfD's or SF's;
• Factors that could either Over or Underestimate
Exposure/Risk;
• Use of 1/2 the detection limit; and
• Possible occurrence of hotspots.
6.3.6 Central Tendency Exposure
In February 1992 a guidance memorandum from the Deputy
Administrator of EPA required that all Superfund risk assessments
evaluate both reasonable maximum exposure (RME) and central
tendency exposures. Exposure assumptions in the ROD up to this
section have been based on RME. The central tendency scenario
represents the risk from more of an "average" exposure (see
Table 22).
6.4 ECOLOGICAL RISK ASSESSMENT
The objective of the ecological risk assessment is to
identify and estimate the potential for adverse ecological
effects to terrestrial and aquatic flora and fauna from exposure
to hazardous substances found in the soil and surface waters at
the Vertac site, including Rocky Branch Creek. An ecological
risk assessment is subject to a wide variety of uncertainties.
Virtually ever step in the risk assessment process involves
numerous assumptions that contribute to the total uncertainty in
the final evaluation of risk. The uncertainty incorporated in
this assessment may result in an increase or decrease of the
estimation of potential ecological risks. However, when
possible, conservative approaches are used in uncertain
situations. The conservative method tends to increase the
estimated risk and therefore is protective of ecological
resources. The substance of potential concern concentration
data, exposure assessment factors, and toxicity value selection
are the major contributors to uncertainty in the risk assessment.
Therefore, the ecological risk assessment for the OU2 media used
conservative, yet realistic, assumptions.
In general, the approach for conducting the ecological risk
assessment parallels that used in the human health risk
assessment. Habitats and organisms potentially affected by site-
related chemicals were identified. For some organisms, the risk
estimated was due to direct exposure to site chemicals, such as
through ingestion of site surface water, and for other organisms
simple models were used to determine exposure to site
76
-------
Summary of Potential Cancer Risks and Hazard Indices" —
Central Tendency Case
Scenario
Trespasser
Current Unprotected Worker
Future Unprotected Worker
Total Lifetime Cancer Riskb
4E-06 (ChemRisk)
7E-05 OJ.S. EPA)
1E-05 (ChemRisk)
2E-04 (U.S. EPA)
2E-04 (ChemRisk)
2E-03 (V S. EPA)
Total Hazard Index
2E-02
2E-01
2E+03
'Values are rounded to one significant figure.
bChe"iRisk = Cancer risk was calculated using the slope factor for 23,7,8-TCDD developed by ChemRisk.
U.S. EPA = Cancer risk was calculated using the slope factors for i3,7,8-TCDD developed by U.S. EPA.
TABLE 22
-------
contaminants through indirect exposure routes, such as eating
contaminated vegetation. The potential for effects to occur was
evaluated by comparing benchmark criteria, such as acceptable
daily intakes to estimated exposures. This comparison resulted
in the calculation of hazard quotients. In general, a hazard
quotient greater than 1 indicated a potential for impacts to
occur as a result of exposure to a particular chemical.
Potential ecological risks were evaluated for two mammalian
species and three avian species. The potential for adverse
ecological effects on aquatic fauna of the Rocky Branch Creek
were also estimated. The results ->f the ecological risk
assessment showed that each of the organisms evaluated had a
hazard index exceeding the benchmark of 1. The total hazard
indices for the ecological receptors evaluated ranged between 3.4
and 54.
While this data suggests that dioxin contaminated s^^iments
in Rocky Branch Creek have resulted in ecological impacts, until
the site is remediated and the source of dioxin contamination
eliminated, the potential for -.ontinuing impacts exists through
contaminated surface soils, sediment transport and groundwater
seeps. However, with this remedy, the primary source will be
removed through consolidation of dioxin contaminated soils in the
on-site landfill and sediment transport resulting from the sump
overflows and storm water runon/runoff will be reduced or
eliminated through storm water management.
Groundwater seeps from the contaminated areas of the site
into Rocky Branch Creek are currently impeded by the French Drain
system installed along the western edge of the site and bordering
the on-site burial grounds, thereby preventing another potential
source of contamination for Rocky Branch Creek. Stream data
indicates no measurable dioxin concentrations, for example,
following rain events. Since Rocky Branch Creek is not a
perennial waterbody and does not flow through the site, the
removal of the contaminated soils and elimination of untreated
discharges and possible groundwater seeps will essentially
eliminate future impacts. While data suggests that existing
impacts in Rocky Branch Creek are on the decline, any actions to
remove contaminated sediments in Rocky Branch Creek would be cost
prohibitive, but more importantly, any disturbance of the
existing sediment could prove catastrophic, possible even
destroying the entire existing ecosystem. As such, this remedy
in addition to the other on-going remedies at the site will
effectively remove the contamination source and the storm water
transport concern allowing Rocky Branch Creek to continue, in
essence, a natural attenuation process.
In addition to the Ecological Risk Assessment, fish tissue
data collected for TCDD from the Rocky Branch Creek/Bayou Meto
watershed areas near the site suggest that contaminants of
78
-------
concern continue to pose an actual threat to local ecological
receptors. EPA issued a ROD in September 1990 addressing the
Vertac off-site areas. One of the ROD requirements was to
monitor fish in the streams for dioxin and continue the ban on
commercial fishing and the advisory that discouraged sport
fishing as long as fish tissue dioxin levels are above Food and
Drug Administration (FDA) alert levels. FDA issued a health
advisory stating that fish with 2,3,7,8-TCDD > 50 parts per
trillion (ppt) should not be consumed, and levels below 25 ppt
pose no serious health threat. Based on this guidance, the
Arkansas Department of Health (ADH) has established an advisory
level of 25 ppt in fish flesh. The current advisory encompasses
Bayou Meto from Arkansas Highway 13, upstream to the mouth of the
discharge from Jacksonville West Wastewater Treatment Plant,
including Rocky Branch Creek and Lake Dupree.
Based on 1994 fish tissue sampling results, dioxin
concentrations appeared to generally decrease with increasing
distance from the site. The highest dioxin concentrations were
found in Big Mouth Buffalo from Rocky Branch Creek and Bayou Meto
upstream of Hwy 67-167. The concentrations found were 73 ppt and
94 ppt as TCDD TEQ's, respectively. Concentrations of TCDD for
White Crappie at the Rocky Branch Creek location was 26 ppt, and
19 ppt for Large Mouth Bass at the Bayou Meto 67-167 location.
At the Arkansas Highway 161 location, TCDD concentrations ranged
from 22 to 36 ppt depending upon the species of fish sampled.
In comparison, as a part of EPA's National Bioaccumulation
Study (EPA, 1992), fish data were collected to help identify
background levels of dioxin in fish. Sixty fish samples were
collected from fresh and estuarine waters at a total of 34 sites
away from points of obvious industrial activity. The average TEQ
was 1.2 ppt (assuming half the detection limit for non-detects).
When looking at all areas (not just pristine or background) EPA
(1992) found an average of 11 ppt TEQ for 314 stations sampled.
6.5 REMEDIAL ACTION GOALS
A Remedial Action Goal (RG) is a chemical-specific
concentration for each chemical of concern that helps determine
whether a contaminated medium may be left in place or must be
addressed in the site remediation effort. Media exhibiting
contaminant concentrations below the RG's may be left in place
without treatment. Those wastes that exceed the RG's at the site
will be addressed to meet requirements set out in the performance
standards for each medium.
Two different risk assessment approaches were conducted for
Vertac soils in order to realistically evaluate appropriate
Remediation Goals (RG's) for site contaminants based on given
land use and exposure assumptions. The first method, Reasonable
Maximum Exposure (RME), is based on EPA risk assessment guidance
79
-------
(see Risk Assessment Guidance for Superfund: Volume I: Human
Health Evaluation Manual (Part A) (Interim Final, EPA/540/1-
89/002, December 1989), and the second method was based on Monte
Carlo probabilistic risk modeling. Soil cleanup levels derived
from these two risk assessment methodologies can differ for any
given exposure scenario. Examples of assumptions that go into
the models to develop cleanup standards include how often a
person visits a site, how long the person stays there during each
visit, how much soil or dust a person is exposed to at the site,
how contaminated the soil is, and how hazardous the contamination
in the soil is. One of the principle differences between the two
risk assessment methodologies is that RME uses one combination of
values for each of these input assumptions (which is high but
reasonably possible), and Monte Carlo uses a wide range of values
for each input parameter.
Over the past year, EPA has met on numerous occasions with
various local civic groups and community leaders to discuss
cleanup activities at the Vertac site. One common element from
those discussions included concern over the potential for future
commercial redevelopment of the site, or portions of the site.
See discussion at Sections 3.0 and 4.0 above. With that in mind,
EPA has developed soil cleanup goals for dioxin at the Vertac
Site that would be protective for a worker in a
commercial/industrial setting. EPA acknowledges that certain
portions of the site will be unavailable for potential future
redevelopment, i.e.. areas that house landfills, and areas that
are otherwise encumbered by long-term remediation or other
perpetual operations and maintenance. Also, input from the
community stressed that the workers required to maintain these
restricted portions of the site should also be protected to a
commercial/industrial level and not be required to wear
"moonsuits" to conduct their activities in the community.
Anotht- community concern is that t.ie smallest area possible be
fenced so that future potential commercial/industrial development
is possible. EPA expects the fence along Marshall Road will be
moved west in phases as the remedial action completion allows.
However, EPA will not know until the remedial design phase of the
OU2 remediation the precise location of the fence it will require
Hercules, Inc., to install. With this in mind EPA analyzed the
risk for a "casual passerby". EPA has concluded that any future
passerby is fully protected by any risks from the site. See
Section 6.3.2 - Casual Passerby.
The two primary contaminants in Vertac soils that will
require remediation are dioxins and furans as 2,3,7,8-TCDD
toxicity equivalents (TEQ's), and tetrachlorobenzene (TCB). TCDD
contamination is present across a wide area of the site and was
an unwanted byproduct from the production of the herbicide
2,4,5-T. TCB contamination, however, is only found in a
localized area or "hot spot" and is the result of a railroad tank
car spill. RG's were not developed for other contaminants of
80
-------
concern at the site because they will be well below health-based
action levels after dioxin remediation takes place.
Following is a summary of EPA's risk evaluation used to set
site remediation goals for dioxin and furans (TEQ) at Vertac.
EPA evaluated a 50 ppb, 20 ppb, and a 5 ppb as not-to-exceed
cleanup values for TCDD (TEQ) at the Vertac site using both RME
and Monte Carlo risk analysis. Some of the assumptions used in
the modelling included a worker scenario, non-detects were
counted as 0.15 ppb (1/2 the detection limit), and that all
remediated grids would be replaced with clean fill. Table 23
presents all the parameters and values u^ed in the RME
calculations and Table 24 presents the parameters and values used
in the Monte Carlo calculations. An RME and Monte Carlo
simulation was run for each of the soil cleanup levels and the
results of those analyses are shown in Table 25.
The RME results show that the excess lifetime cancer risk
associated with an average exposure point concentration of 50,
20, and 5 ppb, are 7.6 x 10-3, 3.0 x 10-3, and 7.6 x 10-4
respectively. Compared to RME risks, the Monte Carlo simulation
risks were 3.1 x 10-3, 1.2 x 10-3, and 3.1 x 10-4 respectively
using the 95% probability distribution point when Monte Carlo
analyses are run with the fixed point concentrations of 50, 20,
and 5 ppb respectively. These results also support the
conclusion that any risk posed to a casual passerby is well
within EPA's acceptable risk range.
In order to more realistically evaluate the exposure
concentration of a person at the site, grid averaging was
employed to determine the actual exposure concentration, rather
than defau1ting to the cleanup goal as the exposure point
concentration. In order to accomplish this, EPA next ran both
the RME and Monte Carlo simulations on the arithmetic mean (using
the 95% upper confidence limit (UCL95; of dioxin that would be
present at the site after remediation. For not-to-exceed cleanup
values of 50, 20, and 5 ppb, arithmetic mean values of 2.92, 1.8
and 0.676 ppb were obtained. The RME excess cancer risks
associated with 2.92, 1.8, and 0.675 ppb were 4.4 x 10-4, 2.7 x
10-4 and 1.0 x 10-4 respectively.
For the Monte Carlo analysis, the lognormal distribution of
these residual grids were used as the concentration term, and the
excess lifetime cancer risk at the 95% probability distribution
were 1.8 x 10-4, 1.1 x 10-4, and 4.1 x 10-5 for not to exceed
values of 50, 20, and 5 ppb. Table 26 depicts the RG's developed
for the Vertac site.
81
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ta
w
n^v-amo^rs and Values Used in the RME Risk Calculations Assuming a
u «.*, *<«! Sorker Scenario Exposed Through Oral and Dermal Routes to Soil
gonŁam?naŁed v?"* '-"%.8-TCDD TEQS at Vertac, Inc. Superfund Site.
Parameter
Concentration (C,)
Conversion Factor (CF)
Fraction^
Body Weight
Averaging Time (AT^
Dermal Slope Factor
Oral Cl"pa Factor (SF^
d)
Units
mg/kg
kg/mg
cm
Unitless
years
days/year
Unitless
Unitless
kg
days
/ing/kg/day
/mg/kg/day
Value
0.005
1E-06
5000
0.03
250
Source
Soil Cleanup level
US EPA, 19891
US EPA, 19922
EPA, 1992
US EPA, 1992
US EPA, 19913
US EPA, 1991
US EPA, 1991
0.5
25550
284000
156000
UC EPA,
US EPA, 1989
UJ EPA, 199la4
US EPA, 199la
US EPA, 1992
US EPA, 19945
. ,l1sted by the following equations, adapted from EPA guidances*1 •2-3-4>
Risk was calcuiatea uy
Risk * (
BW * AT
L-*-
BW
I * ABS0 * EF * ED * SF0 )
AT
-------
H
s
r<
N3
•P-
^ U
rke'r ISena
%rt«c '"•-
Parameter
Units
2,3,7,8,-TCDD
TEQs
Adult Skin
Surface Area
ci2
Fraction of
Skin Exposed
25550
0.287
50
Monte Carlo Simulations and RME Risk Calculations Assuming a
rough Oral and Denal Routes to Soil Contaminated v tth 2,3,7,8-
e.
te Carlo
verage
74
49
49
>4
)155
0
B*.
.9
Monte Carlo
95th %le
2.1
18194
0.329
1.2
0.0286
250
34.4
88.5
Distribution
Type
Log normal
Lognormal
Uniform
Triangular
Uniform
Fixed Point
Estimate
Cumulative
Lognormal
Distribution
parameter?
M * 0.674
SD = 0.8739
Males
M = 19400
SD = 37.4
Females
M = 16900
SD = 37.4
Min. = 0.161
Max. = 0.338
Min. = 0.2
Best =0.2
Max. = 1.5
Min. = O.T01
Max. = O.oJ
Min. = 0
I Max. = 48
Males
GM =ln 76.71
GSD = In1.19
Females
Source
Site
data
USEPA,
1992
USEPA,
1992
USEPA,
1992
USEPA,
1992
USEPA,
1991
HERCULES
1994
Smith,
1994
Fixed Point
Estimate
Unifonm
Fixed Point
Estimate
GM =ln 64.72
GSD =ln1.22
Min. = 0.05
Max. = 0.3
USEPA,
1991
HERCULES
1994
USEPA,
1991
-------
03
r1
O
o
3
Parameter
Fraction Soil
Contaminated
Unitless
Used in Monte Carlo Simulations and RME Risk C.- 'culations Assuming a
-1-——- s°u c ~" ™
7.5E-04
Monte Carlo
Average
0.5
1.0E-06
1.0E-05
1.0E-05
Monte Carlo
95th %le
0.5
4.1E-06
4.1E-05
4.1E-05
Distribution
Type
Fixed Point
Estimate
Distribution
parameters
Source
USEPA,
1989
H =
tandard viation. UM = beo»etric Meai, U5U = ueo.etric Standard Deviation.
-------
Pathways
Comparison of
Expj
Type of Risk
Estimate
Fixed Point RME
(RME) and Monte Carlo Risk Estimates - Worker
Ingestion Plus Dermal Contact with Soil.*
Fixed Point RME
Using 95% UCL on the
Arithmetic mean of
residual grids.
Monte Carlo
Lognornal
Distribution of
Residual Grids
Average
Maximum
Minimum
Percenti*tes_
25
50 %_
75A
95 %
100 %
from
negligible
Lifetime Cancer Risk
Soil Ł50 ppb Removed
Cleanup - 50 ppb
7.6E-03
Cleanup = 2.92 ppb
4.4E-04
Ave =3.210, SD-6.840
Monte Carlo Ave=3.12
Monte Carltt_95t"H.l
Cleanup =20 ppb
3.0E-03
mp = 1.
2.7E-04
cer Risk
Removed
ppb
8 ppb
Lifetime Cancer Risk
Soil Ł5 ppb Removed
Cleanup = 5 ppb
7.6E-04
Cleanup = 0.675 ppb
l.OE-04
5.1E-09
3 . IE- 06
.OE-05
9.6E-5
Ave=1.933, SD= 3.610
Monte Carlo Ave=1.90
Monte Carlo 95%=6.6
2.7E-05
3.8E-03
8.5E-09
Ave=0.674, SD=0.8739
Monte CarloAve=0.674
Monte Carlo 95%=2.1
l.OE-05
1.3E-03
4.7E-09
1.8E-04
3.9E-03
2.0E-06
6.5E-06
2.0E-05
6.1E-05
1.1E-04
3.8E-03
Con 01
SO]
was not consi<
Lnce risk
9.3E-07
2.8E-06
8.4E-06
2?3E-05
4.1E-05
1.3E-04
througn this "route
is
-------
Table 26. Remediation Goals for Contaminated Soil Media,
CONTAMINANT
Dioxins & Furans (TEQ)
Tetrachlorobenzene
REMEDIATION GOAL
5 ppb
500 ppm
Information from EPA's site specific risk assessment showed
that a RG of 5 ppb TEQ for dioxin was necessary to be protective
for a worker exposure scenario. The ris\ associated with a not-
to-exceed soil cleanup value of 5 ppb dioxin ranged from between
1X10"1 to 4X10-5.
A second soil RG was also established for tetrachlorobenzene
(TCB) associated with a spill area at the site. All crystalline
TCB, and TCB in site soils greater tLan 500 ppm would be
excavated and treated off-site.
7.0 DESCRIPTION OP ALTERNATIVES
7.1 ALTERNATIVES
Alternatives for remediation were developed in the FS by
assessing technologies and the range of media to which they would
be applied. The FS considered separate "stand alone"
alternatives for the two media addressed by Operable Unit 2, they
are:
• Soils - There are two components to the soils alternatives.
The first component involves both on-site surface and
subsurface soils that have not yet been excavated and bagged
soils excavated from contiguous off-site residential
properties as part of an earlier removal action. These
bagged soils are discussed in the FS for OU1, and the OUl
ROD deferred the treatment of those soils until all site
soils were to be addressed.
The second component involves an amendment to the 1990 ROD
for Off-Site Areas, which had selected incineration as the
treatment method for contaminated soils and debris from
contiguous portions of Rocky Branch Creek, sludges removed
from the sewage treatment plant and sediments from the sewer
interceptor lines. The sewage treatment plant sludges and
the sediments from the sewer lines are considered to be
contiguous to and within the site's area of contamination
(AOC) due to the continuous connection from the site to the
sewage treatment plant by way of the sewer line.
86
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The Agency intentionally deferred treating those materials
from the Off-Site ROD until all site soils were to be
addressed. In addition, the on-site incinerator is no
longer operational, the 1990 Off -Site ROD materials came
from contiguous areas within the site's AOC, and the
materials are similar to the contaminated soils and debris
addressed in this ROD. Therefore, EPA has determined that
these materials are appropriately addressed in a manner
consistent with the remedy selected for this operable unit.
For those reasons, in conjunction with this ROD, the EPA
will also amend the 1990 Off-Site ROD to reflect the change
in approach.
• Underground Structures - this includes underground
utilities, foundations, curbs, and pads. (As discussed
above, Hercules, Inc., has .recently addressed the fuel
storage tanks by draining them and filling the drained tanks
with flowable grout so as to prevent any possible leakage of
residues. Therefore, this ROD need not address those tanks
as had been proposed in the FS . )
SOILS
The following is a summary of the soils alternatives
presented in the FS. A more detailed description of the
alternatives can be found in the OU2 FS report itself.
The alternatives evaluated in the FS differed from one
another principally in two ways: First by the cleanup level
presented for TCDD in soils (i.e. . the level of TCDD that would
be left on the ground after remediation to be protective for a
specific future site use) , and secondly; by the concentration of
TCDD in soils that would be subjected to various treatment,
containment, and/or capping options.
Three series of action levels for TCDD in site soils were
presented in the FS for many of the alternatives evaluated.
These action levels were presented by Hercules in the FS as a
guide for costing purposes only. The cleanup levels for the
site, however, were established by EPA after evaluating the risk
assessment. EPA made those decisions after the completion of the
FS, which presented the entire universe of possible alternatives.
However, not all of those alternatives remain under consideration
after initial screening by EPA.
27 presents a summary of the soils alternatives
evaluated for this ROD, and Tabl« 28 presents a summary of the
quantities of materials addressed by the various treatment
options.
This ROD will address on-site soils and underground
utilities and the contaminated soils and debris from the 1990
87
-------
H
f
w
T»blc 27
SUMMARY SURFACE SOILS ALTERNATIVES
Consolidation
TCDD>500
Bagged SoiU
TCDD>200
Bagged Soib
50050
Bagged SoiU
TCDD>20
Bagged Soils
Desorption
TCDD>2000
TCB Spill Soib
TCDD>1000
TCB Spill Soib
TCDD>2000
TCB Spill Soils
TCDD>50
TCB Spill Soib
TCDD>20
Bagged Soib
TCB Spill Soib
Dechlori nation
Desorbed TCDD-
related liquids
Desoibed TCDD-
relale- 1 liquids
Desoibed TCDD-
relaled liquids
Onsite Incin
TCDD>2000
TCDD>1000
Offsite Incin
Ciyitalline TCB
A Spill Soib
Crystalline TCB
& Spill Soib
Crystalline TCB
desorbed TCB
Crystalline TCB
deiorbed TCB
Crystalline TCB
desorbed TCB
Crystalline TCB
& Spill Soib
Crystalline TCB
t Spill Soib
Crystalline &
desorbed TCB &
TCDD ocndensate
Crystalline ft
desorbed TCB *
TCDD condensate
TCDD > 50
Crystalline TCB
A. Spill Soib
TCDD > 20
Bagged Soib
Crystalline TCB
& Spill Soib
Crystalline TCB
& Spill Soib
Crystalline TCB
& Spill Soib
Crystalline TCB
& Spill Soib
Crystalline TCB
& Spill SoiU
-------
Table 28
SUMMARY OF QUANTITIES OF MATERIALS UNDER SOILS ALTERNATIVES
w
K3
00
-------
Off-Site Areas ROD (sludges from the sewage treatment plant and
sediments from the interceptor lines), soil? that will be
excavated from Rocky Branch Creek flood plain deferred in the
1993 OU1 ROD, and bagged soils removed from contiguous
residential areas as part of a removal action conducted by
Hercules, Inc. The disposition of the 1990 Off-Site Areas ROD
materials and the bagged residential soils Hercules had excavated
as part of a 1990 removal action was deferred in both the 1990
Off-Site Areas and the 1993 OU1 RODs, and also was evaluated in
the Operable Unit 2 FS, because those materials are essentially
identical media as OU2 soils in that they also constitute low
level threat media as discussed in Section 4.0 above. One should
note that the decision to address the disposition of the 1990
Off-Site Areas ROD materials as part of the ROD for OU2 does not
alter any other aspects of the 1990 Off-Site Areas ROD, such as
the l ppb TCDD cleanup level for flood plain soils.
Alternative l Mo Action
DESCRIPTION
The no action alternative for OU2 media at the site provides
a basis for comparing existing site conditions with those
resulting from implementation of the other proposed alternatives.
Under the no action alternative, no additional measures would be
used to remediate contaminant sources. Access to the site would
be prohibited only by the existing site fence. Therefore, public
access would only be passively restricted. No institutional
controls, facility maintenance, or monitoring would be
implemented, except for those being performed in accordance with
the 1984 Court Order.
Implementing no remedial activities for the OU2 media at the
site allows the existing contaminant sources to remain in place.
The potential for exposure to contaminants is not reduced under
this alternative.
The Superfund program requires that a no action alternative
be considered at every site as a basis of comparison when
evaluating other alternatives. This alternative would not
decrease the toxicity, mobility, or volume of contaminants or
reduce public health or environmental risks to acceptable levels.
Also, this alternative would not comply with State and Federal
environmental regulations, and therefore, is not favored by EPA.
COST AND TIME OF IMPLEMENTATION
Capital Cost: $0
Operation and Maintenance: $0
Total Cost: $0
Time of Implementation: 0 years
90
-------
Alternative 8-2 Containment and Consolidation
DESCRIPTION
Under this alternative, no action would be applied to
surface soils with a TCDD concentration of 50 ppb or less.
Surface soils exceeding the action level of 50 ppb but less than
500 ppb TCDD would be covered with a 12 inch thick layer of clean
soil to prevent direct exposure and to reduce the potential for
surface migration of contaminated soil (see Figure 11).
The 10-fold range in the action level addressed by the soil
cover is based on the assumption that if the soil is disturbed by
site workers, the contaminated soil would be diluted by a ratio
of 10 to 1 dilution with the clean soil before exposure to
workers occurs. The 10 to 1 dilution would yield an exposure
concentration and therefore an equivalent risk of exposure to
below the action level. This approach is consistent with that
applied by EPA for dioxin-contaminated soils at other CERCLA
sites in Region 6, such as the related RODs for both the
Jacksonville and Rogers Road Municipal Landfill sites. In
addition, a 10-fold increase in the dioxin level for soils below
a depth of 1 foot was also used by EPA for the Missouri dioxin
sites.
Under this alternative, surface soils to a depth of one foot
below ground surface exceeding 500 ppb TCDD and bagged
residential soils Hercules had excavated as part of a 1990
removal action from contiguous residential areas would be
consolidated (landfilled) on-site. Excavated areas would be
backfilled to grade using clean soil and revegetated. The
excavated materials would be placed into the
consolidation/containment unit (CCU) whic>> was included as part
of the selected remedy for certain OU1 materials. As described
in greater detail in the portion of Section 7.2 below entitled
"Consolidation," although dioxin-contaminated media constitute a
listed RCRA waste whose applicable land disposal restriction
(LDR) treatment standard is defined at 40 CFR 5 268.31, those
requirements are not applicable due to the fact that placement,
the triggering element for the imposition of LDR's, will not take
place. This is due to the fact that all media proposed to be
consolidated within the on-site RCRA Subtitle C hazardous waste
landfill come from within the site's area of contamination (AOC),
or fall below the 5 ppb treatability variance range EPA has
selected for dioxin-contaminated Vertac media in a July 18, 1996,
Action Memorandum found in the Administrative Record. The CCU
presented in the OU2 FS would be a modification or enlargement of
the CCU to be constructed for OU1 materials. Modifications to
the CCU would incorporate design standards required for a RCRA
Subtitle C hazardous waste landfill (see Figure 12).
Nonetheless, the CCU will meet all applicable substantive RCRA
91
-------
PJ
Vegetation
-
Topsoil
-77- xV\
: Grid Bounda :
\' • \ riginal Surface So
'' ' ' ' C ',\ '.lj ' Grid
.'V,,,N-i Original Surface Soils . , x._,^, x ^ x. ^ , ^._,^ x ,p-«^ ' •-_»,- •• •, » t- -»v- _»,' - ",
•//V'XX",V-'/V'''^I^~'/\'''NI\~ N' x ' 1 x > x ~ j'\''^»^~'/\''-xi»~ ,
\x * \ , - ' v , ^ ' ' f - ' , ^ ' ' ' - " , ^ ' ' - - ' I . ^ ' ' • - - V '*s - -
_ v I ~ - ^x ' - x '_ - ' ^ , ' ~ * ~ ~ ' 2 , ' ~ * - ' - ,' ~ \ ~ ' ^ ' - x ' " - -^ ' - -
^'" " ' ~~' i . L '" ''/" x' ,' - '- ' ''/" x' ,' -x 1 ' '',"!.,'- ~ ^ -\^ ^,' - L ^ -'/''-'- ^ -'
Not to Scale
CONCEPTUAL DIAGRAM OF SOIL COVER - CROSS-SECTION
-------
Gas Vent
Leachate
Collection System
Primary FML
(80 Mil)
12" Sand for
Lateral Drainage
Leachate Detection
System
Secondary FML
(80 Mil)
36" Clay (10 7cm/sec)
Liner
Approximate Height Above
Ground Surface = 30'
12" Topsoil/Vegatative Cover
6" Sand for Lateral Drainage
36" Clay (10 7 cm/sec) Cap
Waste i ayer
Slope = 3:1
12" Sand for
Lateral Drainage
Ground
Surface
94P-1307 3/4/94
DOUBLE-LINED CONSOLIDATION/CONTAINMENT UNIT - CONCEPTUAL CROSS-SECTION
-------
standards for the design, construction, and operation of a
hazardous waste landfill found at 40 CFR Part 264.
Except for the TCB spill area, subsurface soils at depths.
greater than 1 foot below the ground surface would remain in
place because there are no direct exposure pathways to subsurface
soils. An indirect exposure pathway is present through the
potential migration of site compounds from these soils into
ground water. However, site-related compounds, especially TCDD,
bind tightly to the soils and are not considered very mobile.
The crystalline TCB and associated soils exceeding the
action level of 500 ppm will be excavated and transported off-
site for incineration at a RCRA-permitted facility. The
treatment residuals from the TCB and related soils would be
disposed of by the off-site facility that performs the treatment.
Administrative and engineering control of site access would
be implemented. Administrative controls would include deed
notifications to limit future land use for the portion of the
property that will remain fen~-d. Engineering controls would
include maintenance of the following: The site fence, engineered
structures proposed under OU1 (i.e.. the CCU), and the soil and
vegetative cover over areas that received clean backfill after
excavation of the dioxin-contaminated soil, and any other
backfill necessary to achieve final site grading to facilitate
positive drainage. Monitoring and maintenance of the site would
also be performed.
Alternative S-2 reduces potential exposure to target
compounds at the site through off-site treatment of TCB
contamination and consolidation or containment of TCDD-
contaminated soils. Under this alternative approximately 83
percent of the TCDD-contaminated soil will be covered or
isolated. Implementation of this alternative and the options to
this alternative effectively address the low level threats posed
by the media subject to the OU2 ROD by containing, versus
treating, those media within the RCRA Subtitle C hazardous waste
landfill. This approach is expressly endorsed for low level
threat wastes whose treatment is impracticable at NCP Section
300.430(a)(iii)(B), 40 CFR S 300.430(a)(iii)(B), which states:
EPA expects: to use engineering controls, such as
containment, for wastes that pose a relatively low long-term
threat or where treatment is impracticable.
COST AND TIME OF IMPLEMENTATION
Total Capital Cost: $5,896,000
Operation and Maintenance: $37,700
Total Present Worth: $6,500,000 (rounded)
Time of Implementation: 2 years
94
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Alternative 8-2, Option A
DESCRIPTION
Option A provides the same remedial actions for the OU2
soils as Alternative S-2 except with different action levels for
TCDD. Bagged soils from contiguous residential areas and
crystalline TCB and spill-related soils would be the same as that
described for Alternative S-2. For Alternative S-2A, only
surface soils with TCDD concentrations above 20 ppb would be
addressed. Those surface soils greater than 200 ppb TCDD would
be excavated and placed in the on-site CCU, and those soils with
concentrations greater than 20 ppb, but less than or equal to 200
ppb, would be covered (capped with clean backfill) in place.
COST AND TIME OF IMPLEMENTATION
Total Capital Cost: $6,398,000
Operation and Maintenance: $37,700
Total Present Worth: $7,000,000 (rounded)
Time of Implementation: 2 years
Alternative 8-3 Containment, Consolidation and On-site
Desorption and Chemical Treatment
DESCRIPTION
This alternative is the same as S-2, with the following key
differences. Surface soils with concentrations of TCDD exceeding
2,000 ppb will be treated on-site. Two options to this
alternative are evaluated, Alternatives S-3A and S-3B, which use
the same remedial approach but are based <~>r> different action
levels. Treating soils with concentrations of TCDD greater than
2,000 ppb would permanently reduce toxicity, mobility, and volume
of a large portion of the TCDD. The on-site treatment process
would consist of thermal desorption of the soils to extract the
organic compounds, including TCDD. The organic compounds would
exit the treatment process as a condensate which will be treated
by chemical dechlorination. Chemical dechlorinate residuals
would be incinerated off-site. The treated soil residuals would
be considered to be clean and would be used in the CCU as fill,
or they would be delisted and used on the site for grading
purposes.
Soils associated with the TCB spill would be desorbed on-
site, with the desorption residuals incinerated off-site.
Crystalline TCB would be sent off-site for treatment at a
permitted facility.
95
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$8,546,000
$37,700
$9,100,000 (rounded)
3 years
COST AND TIME OF IMPLEMENTATION
Total Capital Cost:
Operation and Maintenance:
Total Present Worth:
Time of Implementation:
Alternative 8-3, Option A
DESCRIPTION
Alternative S-3A would address surface soils with TCDD
concentrations greater than 20 ppb. Surface soils with TCDD
concentrations greater than 1,000 ppb would be subjected to on-
site thermal desorption. Soils with TCDD concentrations greater
than 200 ppb and less than or equal to 1,000 ppb would be
excavated and consolidated in the on-site CCU. Surface soils
with TCDD concentrations greater than 20 ppb but less than or
equal to 200 ppb would be left in place and covered with a one
foot thick soil cover. Other media such as the bagged soils from
contiguous residential areas, crystalline TCB, and spill-related
soils would be treated the same as under Alternative S-3.
COST AND TIME OF IMPLEMENTATION
Total Capital Cost:
Operation and Maintenance:
Total Present Worth:
Time of Implementation:
Alternative 8-3, Option B
$9,396,000
$37,700
$10,000,000 (rounded)
3 years
Alternative S-3B provides for on-site thermal desorption of
surface soils with TCDD concentrations in excess of 2,000 ppb,
consolidation in the on-site CCU of surface soils with TCDD
concentrations between 350 ppb and 2,000 ppb, and covering of
surface soils with TCDD concentrations greater than 35 ppb.
Other media such as the bagged soils from contiguous residential
areas, crystalline TCB, and spill-related soils would be treated
the same as Alternative S-3.
COST AND TIME OF IMPLEMENTATION
Total Capital Cost:
Operation and Maintenance:
Total Present Worth:
Time of Implementation:
$8,687,000
$37,700
$9,300,000 (rounded)
3 years
96
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Alternative 8-4 Containment, Consolidation and On-site
Incineration
DESCRIPTION
The actions described under Alternative S-3 would be
implemented under this alternative except that on-site
incineration would be used in place of thermal desorption and
dechlorination for surface soils with TCDD concentrations
exceeding 2,000 ppb. One option to this alternative, Alternative
S-4A, was also evaluated. The soils associated with the TCB
spill exceeding 500 ppm and the crystalline TCB would be
transported to an off-site incineration tacility for treatment
because of their non-F listing. Residuals resulting from on-site
incineration would be consolidated with other OU2 media in the
ecu.
COST AND TIME OF IMPLEMENTATION
Total Capital Cost: $8,900,000
Operation and Maintenance: $37,700
Total Present Worth: $9,500,000 (rounded)
Time of Implementation: 3 years
Alternative 8-4, Option A
DESCRIPTION
Surface soils with TCDD concentrations in excess of 1,000
ppb would be treated by an off-site incinerator. Surface soils
"\th TCDD concentrations greater than 200 ppt vut less than or
equal to 1,000 ppb would be placed into the on-site CCU. Soils
exceeding 20 ppb TCDD but less than or equal to 200 ppb would be
covered in place.
COST AND TIME OF IMPLEMENTATION
Total Capital Cost: $10,959,000
Operation and Maintenance: $37,700
Total Present Worth: $11,500,000 (rounded)
Time of Implementation: 3 years
Alternative 8-5 On-site Desorption with Off-site incineration
DESCRIPTION
Under this alternative, surface soils with TCDD
concentrations above 50 ppb and soils associated with the TCB
spill would be excavated and treated on-site by thermal
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desorption. One option to this alternative, Alternative S-5A,
was also evaluated. The condensate from the thermal desorption
process would be transported off-site for incineration at a RCRA-
permitted facility. The treatment residues would be disposed of
by the treatment facility. The soils from OU1 would be placed
into the on-site CCU.
$14,603,000
$10,400
$14,800,000 (rounded)
4 years
COST AND TIME OF IMPLEMENTATION
Total Capital Cost:
Operation and Maintenance:
Total Present Worth:
Time of Implementation:
Alternative 8-5, Option A
DESCRIPTION
Alternative S-5A provides for the same excavation, on-site
treatment, and off-site incineration for the surface soils as
Alternative S-5, except that a lower action level of 20 ppb for
TCDD applies. Bagged soils from contiguous residential areas and
TCB spill soils would also be treated using the on-site thermal
desorption process.
COST AND TIME OF IMPLEMENTATION
Total Capital Cost:
Operation and Maintenance:
Total Present Worth:
Time of Implementation:
$26,636,000
$10,400
$26,800,000 (rounded)
4 vears
Alternative 8-6
DESCRIPTION
Off-site Incineration
Under this alternative, surface soils with TCDD
concentrations above 50 ppb, crystalline TCB, and the soils
associated with the TCB spill exceeding 500 ppm would be
excavated and incinerated off-site at a RCRA permitted facility.
One option to this alternative, Alternative S-6A, was also
evaluated. Treatment residues from off-site incineration would
be disposed of by the off-site treatment facility. The bagged
soils from contiguous residential areas would be consolidated
into the on-site CCU.
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COST AND TIME OF IMPLEMENTATION
Total Capital Cost: $62,089,000
Operation and Maintenance: $10,400
Total Present Worth: $62,200,000 (rounded)
Time of Implementation: 5 years
Alternative 8-6, Option A
DESCRIPTION
Alternative S-6A provides for the same excavation and off-
site incineration for the surface soils, but applies to a lower
action level of 20 ppb TCDD.
$164,601,000
$10,400
$164,800,000 (rounded)
5 years
COST AND TIME OF IMPLEMENTATION
Total Capital Cost:
Operation and Maintenance:
Total Present Worth:
Time of Implementation:
Alternative 8-7 Containment (Capping)
DESCRIPTION
Under this alternative, no action would be applied to
surface soils with a TCDD concentration of 50 ppb or less. The
surface soils exceeding the action level of 50 ppb TCDD would be
covered with a 12 inch layer of clean soil to prevent direct
exposure and reduce the potential for migration of surface soils
due to rair fall and wind. An option to this alternative, S-7A,
would use the same remedial approach but with different TCDD
action levels was also evaluated.
'^he crystalline TCB and associated TCB spill-related soils
exceeding the action level of 500 ppm would be excavated and
transported off-site for incineration at a RCRA permitted
facility. Following treatment of the TCB and associated soils,
the residuals would be disposed of oy the off-site treatment
facility.
Administrative and engineering control of site access as
described in Alternative S-2 would also be implemented.
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COST AND TIME OF IMPLEMENTATION
Total Capital Cost: $5,698,000
Operation and Maintenance: $37,700
Total Present Worth: $6,300,000 (rounded)
Time of Implementation: 2 years
Alternative 8-7, Option A
DESCRIPTION
Alternative S-7A provides for the same remedial actions as
Alternative S-7, except with different action levels for TCDD.
Surface soils with TCDD concentrations above 20 ppb would be
addressed by the remedial action. Specifically, those surface
soils with TCDD concentrations above 20 ppb would be covered in
place with a 12 inch layer of clean soil to prevent direct
exposure and reduce the potential for migration of surface soils
due to rainfall and wind.. Bagged soils from contiguous
residential areas and crystalline TCB and TCB spill-related soils
would be addressed in the --me manner as described under
Alternative S-7.
COST AND TIME OF IMPLEMENTATION
Total Capital Cost: $6,076,000
Operation and Maintenance: $37,700
Total Present Worth: $6,700,000 (rounded)
Time of Implementation: 2 years
Alternative 8-8 Consolidation (Landfilling)
DESCRIPTION
Under this alternative, no action would be applied to
surface soils with a TCDD concentration of 50 ppb or less. The
surface soils exceeding the action level of 50 ppb TCDD would be
excavated to a depth of 1 foot and consolidated on-site in the
CCU. As an option to this alternative, Alternative S-8A would
employ the same remedial approach as under S-8, but with
different TCDD action levels.
The crystalline TCB and associated TCB spill-related soils
exceeding the action level of 500 ppm would be excavated and
transported off-site for incineration at a RCRA permitted
facility. Following treatment of the TCB and associated soils,
the residuals would be disposed of by the off-site treatment
facility.
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COST AND TIME OF IMPLEMENTATION
Total Capital Cost: $6,720,000
Operation and Maintenance: $19,500
Total Present Worth: $7,000,000 (rounded)
Time of Implementation: 2 years
Alternative 8-8, Option A
DESCRIPTION
Alternative S-8A provides for the same remedial actions for
the OU2 surface soils as under S-8, except with different action
levels for TCDD. Bagged soils from contiguous residential areas
and crystalline TCB and TCB spill-related soils would addressed
in the same manner as that described for Alternative Ł-8.
Surface soils with TCDD concentrations above 20 ppb would be
excavated and placed into the on-site CCU.
COST AND TIME OF IMPLEMENTATION
Total Capital Cost: $8,220,000
Operation and Maintenance: $19,500
Total Present Worth: $8,500,000 (rounded)
Time of Implementation: 2 years
UNDERGROUND UTILITIES
Following is a summary of the underground utilities
alternatives presented in the FS. A more detailed description of
the alternatives can be found in Lhe OU? FS report itself.
Table 29 presents a summary of the underground utilities
alternatives.
Alternative D-l No Action
DESCRIPTION
The no action alternative for underground structures would
involve no additional measures employed to address those items.
The underground utilities would remain buried with their contents
in place. Access to the site would be prohibited by the existing
site fence so that public access would be passively restricted.
Specific institutional controls, maintenance, or monitoring would
not be implemented, except for those that would be performed in
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T»ble 29
SUMMARY OF THE UNDERGROUND UTILITIES ALTERNATIVES
M
ho
Chemical sewer,
Underground
storage tanks
NOTES:
1 Aqueous phase treatment at oolite treatment plant.
1 Solid phase treatment will be selected with soils alternative.
Hydroblast/
Scarification
Foundations
and curbs
Foundations
and curbs
Surface Seal
Foundations
aud curbs with
persistent stains
Aqueous Phase
Treatment1
Rinse materials
from flush,
hydroblast
Rinse materials
from flush,
hydroblast
Solid Phase
Treatment2
Recovered solids
from flush,
scarification, and/
or hydroblast
Recovered solids
from flush,
scarification, and/
or hydroblast
-------
accordance with the monitoring and maintenance plan set out in
the 1984 Court Order.
Implementing no remedial activities for the OU2 underground
utilities and foundations at the site allows the existing
contaminant sources to remain in place. The potential for
exposure to contaminants is not reduced in this alternative.
The Superfund program reqri-es that a no-action alternative
be considered at every site as a basis of comparison when
evaluating other alternatives. This alternative would not
decrease the toxicity, mobility, or volume of contaminants or
reduce public health or environmental risks. Also, this
alternative would not comply with State and Federal environmental
regulations, and therefore, it is not favored by EPA.
COST AND TIME OF IMPLEMENTATION
Capital Cost: $0
Operation and Maintenance: $0
Total Cost: $0
Time of Implementation: 0 years
Alternative U-2 Equipment Plugging and Cleaning
DESCRIPTION
Under this alternative, corrective measures would be
implemented to reduce the risk associated with the underground
structures. The chemical sewer would be hydraulically flushed to
remove solids from the line. After flushing, the access to the
sewer would be restricted by installing plugs at all available
access locations. In conjunction with line plugging, subsurface
cut-off barriers would be installed across the line and bedding
cross-section. These cut-off barriers would be constructed of
materials such as clay, membrane sheeting, or other low
permeability material. The purpose of these barriers is to
eliminate potential preferential contaminant migration pathways.
They would be located in the field at points where plugging is
conducted or where migration may occur off-site. Any excess
contaminated soil from the excavation process would be handled in
accordance with the soil alternative.
The foundations and curbs would be cleaned by hydroblasting
using high pressure, low volume water. In areas with persistent
staining, surface scoring (such as scarification) will be used to
remove visible contamination from the exposed foundations and
curbs. Water generated from the sewer flushing and concrete
hydroblasting would be treated in the on-site wastewater
treatment plant. Solids generated from flushing, hydroblasting,
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and scarification would be handled in accordance with the
selected alternative for soils.
COST AND TIME OF IMPLEMENTATION
Capital Cost: $1,229,000
Operation and Maintenance: $0
Total Cost: $1,229,000 (rounded)
Time of Implementation: 1.5 years
Alternative U-3 Equipment Plugging, Cleaning, and Sealing
DESCRIPTION
This alternative is similar to Alternative U-2, with the
following additions. After flushing, the sewer would be filled
with grout to improve the structural integrity of the line and
prevent migration of contaminants through the pipe. In addition,
a surface sealant would be -pplied to foundations and curbs in
areas of persistent staining, i.e.. visible staining that is not
removed by scarification.
COST AND TIME OF IMPLEMENTATION
Capital Cost: $1,359,000
Operation and Maintenance: $0
Total Cost: $1,359,000 (rounded)
Time of Implementation: 1.5 years
7.2 ARAR'B
In conducting a remedial action, EPA is required to attain a
degree of cleanup for s. given site that assures protection of
human health and the environment. "Applicable or relevant and
appropriate requirements" (ARAR's) are the federal, state, or
local requirements that ensure such a cleanup standard. (See
CERCLA Section 121(d), 42 U.S.C. S 9621(d), and NCP Section
300.410(g), 40 CFR S 300.410(g).) Applicable requirements are
those standards, requirements, criteria, or limitations
promulgated under federal environmental, state environmental, or
facility siting laws that specifically address a hazardous
substance, pollutant, contaminant, remedial action, location, or
other circumstance found at a CERCLA site.
Relevant and appropriate requirements are those standards,
requirements, criteria, or limitations promulgated under federal
environmental, state environmental, or facility siting laws that,
while not "applicable" to hazardous substances, pollutants,
contaminants, remedial actions, locations, or other circumstances
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at a CERCLA site, address problems or situations so that their
use may be suited to the particular site. Factors that may be
considered in making this determination, when the factors are
pertinent, are discussed at NCP Section 300.440(g)(2), 40 CFR
S 300.400(g)(2). They include, among other considerations,
examination of: The purpose of the requirement and the purpose
of the CERCLA action; the actions or activities regulated by the
requirement and the remedial action contemplated at the site; and
the potential use of resources affected by the requirement and
the use or potential use of the affected resource at the CERCLA
site.
ARAR's are divided into chemical-specific, location-
specific, and action-specific requirements. Chemical-specific
requirements govern the release to the environment of materials
possessing certain chemical or physical characteristics or
containing specific chemical compounds. Chemical-specific ARAR's
are numerical standards. These values establish the acceptable
amount or concentration of a chemical that may be found in, or
discharged to, the ambient environment.
Location-specific ARAR's relate to the geographic or
physical position of the site, rather than to the nature of site
contaminants. These ARAR's place restrictions on the
concentration of hazardous substances or the conduct of cleanup
activities due to the site's location in the environment (i.e. . a
site located in a flood plain).
Action-specific ARAR's are usually technology- or activity-
based requirements, or are limitations on actions taken with
respect to hazardous substances. A particular remedial activity
will trigger an action-specific ARAR. Action-specific ARAR's
dictate how the selected remedy must be imple r.ted.
Only the substantive portions of requirements are ARAR's.
Administrative requirements are not ARAR's and, thus, do not
apply to actions conducted entirely on-site. Administrative
requirements are those that are non-substantive requirements that
involve such actions as consultation, issuance of permits,
documentation, reporting, record keeping, and enforcement. The
CERCLA program has its own set of administrative procedures that
assure proper implementation of CERCLA because the application of
additional or conflicting administrative requirements could
result in delay or confusion. Provisions of statutes or
regulations that contain general goals that merely express
legislative intent about desired outcomes or conditions, but are
non-binding, are not ARAR's.
State standards that are identified in a timely manner by
the state in which a Superfund site is located and are more
stringent than federal requirements may be applicable or relevant
and appropriate. To be an ARAR, a state standard must be
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"promulgated," which means that the standards are of general
applicability, are legally enforceable, and have been equally
applied.
Additional standards may be identified as "to be considered"
(TBC). The TBC category consists of advisories, criteria, or
guidance which was developed by EPA, other federal agencies,
states, or local agencies that may be useful in developing CERCLA
remedies. These may be considered as appropriate in sele^^g
and developing cleanup actions.
The potential ARAR's for CU2 media are listed in Table 30.
These potential ARAR's were identified based on site-specific
conditions and are described in more detail in the remainder of
this section.
In identifying ARAR's for OU2, it is important to recognize
that the Vertac site has three existing burial areas that are
closed under a 1984 Court Order. In that Order, dated July 18,
1984, in the matter styled U.S. v. Vertac Chemical Corporation
and Hercules/ Inc.. E.D. Ar., Western Division, No. LR-C-80-109,
Judge Henry Woods concluded that the Vertac Plan, which EPA
opposed, but which the State of Arkansas supported, was superior
to an alternative plan submitted by EPA. Specifically, the
Vertac plan allowed the burial in the North Burial Area of
barrelled waste containing up to 100 ppm dioxin and allowed the
burial in that location of chlorinated phenols, anisoles,
chlorinated benzenes, 2,4-D, 2,4,5-T, and the burial of aldrin,
dieldrin and DDT in the Reasor-Hill Burial Area. In addition,
the Court in its Order concluded that the dioxin-containing
barrels buried in the North Burial Area do not pose a serious
danger of moving off-site underground. See Order of July 18,
1984, at page 4. Therefore, pursuant to a final order of the
Court, the containment by burial of dioxin wastes i*»
concentrations up to 100 ppm do not constitute a principal threat
to the public health or the enviiunmenc,
Table 30. Potential ARAR's for the Vertac Site, Jacksonville,
Arkansas
Chemical-Specific
• Resource Conservation and Recovery Act (RCRA), 42
U.S.C. S 6901 et seq.
• Clean Water Act (CWA), 33 U.S.C. S 1251 et sea.
• Safe Drinking Water Act (SDWA), 42 U.S.C. S 300f et
seq.
• Clean Air Act (CAA), 42 U.S.C. S 7401 fit sea.
• Arkansas Water and Air Pollution Control Act, ACA 8-4-
101 - 106 and 8-4-201 - 229, and 8-4-301 - 313
• Arkansas Non-Criteria Air Pollutants Control Strategy
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Table 30 - Continued.
• Arkansas State Ground Water Quality Protection Strategy
• State Implementation Plan for Air Pollution Control,
ADPC&E Reg. No. 19
• Water Quality Standards for Surface Waters of the State
of Arkansas, ADPC&E Reg. No. 2
• State Administration of the National Pollutant
Discharge Elimination System, ADPC&E Reg. No. 6
• Hazardous Waste Management, ADPC&E Reg. No. 23
• Arkansas Air Pollution Control Code (Minor Source,
ADPC&E Reg. No. 18), (Operating Air Permit Program,
ADPC&E Reg. No. 26)
Location-Specific
• Resource Conservation and Recovery Act (RCRA), 42
U.S.C. S 6901 gt seq.
• Arkansas Solid Waste Management Code, ADPC&E Reg.
No. 22
• State Administration of the National Pollutant
Discharge Elimination System, ADPC&E Reg. No. 6
• Hazardous Waste Management (Arkansas), ADPC&E Reg.
No. 23
• Arkansas Air Pollution Control Code (Minor Source,
ADPC&E Reg. No. 18), (Operating Air Permit Program,
ADPC&E Reg. No. 26)
Action—Specific
• Resource Conservation and Recovery Act (RCRA), 42
U.S.C. S 6901 et seq.
• Clean Water Act (CWA), 33 U.S.C. S 1251 et sea.
• Safe Drinking Water Act (SDWA), 42 U.S.C. S 300f et
seq.
* Clean Air Act (CAA), 42 U.S.C. S 7401 eŁ sea.
• Arkansas Solid Waste Management Code, ADPC&E Reg.
No. 22
• state Implementation Plan for Air Pollution Control,
ADPC&E Reg. No. 19
7.2.1 Federal ARAR's
Resource Conservation and Recovery Act (RCRA)
The Resource Conservation and Recovery Act (RCRA), 42 USC §
6901 et seq.):
• RCRA Subtitle C established a comprehensive regulatory
program to control and manage hazardous waste from the time
of generation to disposal.
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• Under RCRA Subtitle D, EPA promulgated regulations
containing guidelines to assist in the development and
implementation of state non-hazardous solid waste management
plans.
RCRA requirements may be ARAR's because some materials at
the Vertac site are solid wastes and also may be considered RCRA
hazardous wastes. In general, RCRA regulations apply to the
management of RCRA hazardous wastes and RCRA waste management
facilities. Regulations promulgated under RCRA generally provide
the basis for management of hazardous waste and establish
technology-based requirements for hazardous waste facilities.
xiCRA facility design standards may also be consulted if
considered relevant and appropriate for wastes other than RCRA
hazardous wastes containing significant concentrations of
hazardous constituents.
Cheaical-Specific Requirements
Hazardous Waste Identification
The regulations governing the identification and
classification of RCRA hazardous wastes are found at 40 CFR Part
261. The two basic classifications of RCRA hazardous waste are:
• Characteristic hazardous wastes (defined at Subpart C of 40
CFR Part 261), which involve evaluation of the following
general waste characteristics:
Ignitability (D001 waste)
Corrosivity (D002 waste)
Reactivity (D003 waste)
Toxicity (D004 - D043 wastes) due to specific chemical-
specific compounds.
• Listed hazardous wastes (defined at Subpart D of 40 CFR Part
261), which involve specific identification of the following
regulatory listings:
Hazardous Waste from Non-specific Sources (F- series wastes
listed at 40 CFR S 261.31).
Hazardous Waste from Specific Sources (K- series wastes
listed at 40 CFR S 261.32).
Commercial Chemical Products (P- and U- series wastes listed
at 40 CFR S 261.33).
Specific tests cited in the regulations are used to
determine if a solid waste also constitutes a RCRA characteristic
hazardous waste. The maximum concentrations of contaminants
allowed in the leachate of a solid waste before the solid waste
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is considered hazardous for the toxicity characteristic (TC) are
presented in 40 CFR S 261.24. Site-related compounds for which a
TC level has been identified include:
Waste Code Compound Name TC Level
DO16 2,4-Dichlorophenoxyacetic Acid 10.0 mg/L
DO41 2,4,5-Trichlorophenol 400 mg/L
DO42 2,4,6-Trichlorophenol 2.0 mg/L
DO17 Silvex 1.0 mg/L
To determine if a solid waste is a listed RCRA hazardous
waste, it is necessary to examine the source of the waste. At
the Vertac site, the manufacture and formulation of insecticides
and herbicides resulted in the generation of process wastes
containing chlorinated benzenes, chlorinated phenols,
chlorophenoxy herbicides, and dioxin. These substances have been
found in the environmental media (soils, ground water, and
surface water) at the site. A comprehensive listing of
mechanisms that released these substances into these
environmental media is unavailable. However, material handling
practices, waste management practices and material releases
during the 45 years of plant operation are the most probable
cause.
A number of mechanisms could be hypothesized based on the
types of activities performed during site operation, but most of
the releases cannot be confirmed and likely occurred prior to the
promulgation of RCRA. An exception is the tetrachlorobenzene
(TCB) spill, which resulted from a known release while
transferring tetrachlorobenzene from a rail car to a material
storage tank and occurred after RCRA's promulgation. Where
spills or releases occurred after the promulgation of RCRA and
it" hazardous waste listings found at 40 CFR P -t 261, RCRA
standards are applicable. Where that is not the case, RCRA
standards would be either relevant or appropriate.
Some of the production processes performed, at the Vertac
site would have generated wastes given hazardous waste numbers
F020, F022, F023, F026, or F027 (40 CFR S 261.31, dioxin-related
hazardous wastes from non-specific sources). These waste numbers
are referred to in this document as "F-02X" wastes and are
defined at 40 CFR S 261.31.
Some of the substances found in the site soils and other OU2
media may have resulted from the release of wastes other than the
F-02X wastes. These wastes could potentially be classified as
follows:
• Listed hazardous wastes from specific sources that are
related to 2,4-D and 2,4,5-T production are defined at 40
CFR S 261.32 as K042, K043, and K099 wastes .
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• Wastes defined at 40 CFR S 261.33 as discarded commercial
chemical products, off-specification species, container
residues, and spill residues thereof. The hazardous waste
identification code U240 (2,4-D salts, and esters) may be
applicable to some of the OU2 media at the site.
• The soils containing residues from a rail car spill
containing still bottoms from the production of
chlorobenzenes (called throughout this FS as the
"tetrachlorobenzene spill soils") may be listed as a K085
specific source listed hazardous waste. K085 listed
hazardous wastes are identified at 40 CFR S 261.32 as
distillation or fractionation column bottoms from the
production of chlorobenzenes.
Historically, some chlorobenzene still bottoms were
purchased from an off-site facility (generated at the off-
site facility during the production of dichlorobenzene) and
were transported via rail car to the site. The stixl
bottoms contained high levels of tetrachlorobenzene and were
dechlorinated on-site as part of the 2,4,5-trichlorophenol
manufacturing process. Prior to use on-site, a hose leading
from a rail car containing the still bottoms to a storage
tank ruptured spilling the chlorobenzenes onto the ground
surface along the rail spur immediately north of the central
process area. These soils are included as part of the OU2
remedial action and may require management as a K085 waste.
• Residues from the treatment of a listed RCRA hazardous waste
are themselves considered RCRA hazardous wastes unless
delisted. Residues resulting from the incineration or
thermal treatment of the F-02X materials would be considered
F028 wastes per 40 CFR § 261.31.
The regulations pertaining to the dioxin-containing F-listed
wastes are more stringent than for the other listed wastes. For
example, 99.9999 percent (six 9's) destruction removal efficiency
(ORE) is required for incineration of these dioxin-containing
wastes, while only 99.99 percent (four 9's) ORE is required for
most other wastes. Regulatory requirements for the land disposal
of the F-02X are also more stringent than for other wastes.
Therefore, complying with the regulations applicable to the F-
listed wastes ensures compliance with less stringent regulations
applicable to non-F02X listed RCRA wastes.
Mixture Rul«/Contain«d-In Policy
The "mixture rule" found at 40 CFR S 261.3 states that a
mixture of a solid waste and a listed RCRA hazardous waste may be
considered a RCRA hazardous waste. This may be applicable to the
solids in the underground piping if the contents are determined
to be mixture of a solid waste and a listed RCRA hazardous waste.
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In the "contained in" policy, the EPA has further expanded the
mixture rule to include environmental media (not considered a
"solid waste" under RCRA) mixed with a listed RCRA hazardous
waste. In this policy, EPA has stated that the mixture of a
listed RCRA hazardous waste and an environmental medium shall be
a listed RCRA hazardous waste until decontaminated and should be
managed as a hazardous waste for as long as the medium contains
the listed waste. As a result of this policy, on-site soils
containing listed RCRA hazardous waste may be required to be
managed as a listed RCRA hazardous waste. See 40 CFR §§
261.3(c)(l) and 261.3(d)(2). Also see the discussion in the
preamble to the proposed NCP revisions, Federal Register volume
53, page 51444 (December 21, 1988).
RCRA Maximal Contaminant Levels (MCL's)
As part of the ground water protection requirements for RCRA
treatment, storage, or disposal facilities (TSD's), EPA has
promulgated at 40 CFR S 264.94 maximum concentrations of
constituents in ground water (RCRA MCL's). The constituents, and
their associated concentrations in ground water, addressed by
this requirement are presented at 40 CFR S 264.94. The standards
for site-related compounds are as follows:
• 2,4-D 0.1 mg/L
• Silvex 0.01 mg/L
These ground water protection standards are equal to MCL's
established in the National Primary Drinking Water Standards
promulgated pursuant to the Safe Drinking Water Act (SDWA) , 42
U.S.C. S 300f et sea. The basic jurisdictional prerequisites for
RCRA MCL's are part of the RCRA ground water monitoring and
response requirements, which apply to RCRA-regulated units
subject to permitting (e.g., landfills, surface impoundments,
waste piles, and land treatment units) that received RCRA
hazardous waste after July 26, 1982. Therefore, RCRA MCL's would
be considered as part of any long-term monitoring program for
most on-site remedial measures. EPA will address the long-term
monitoring of ground water in the ROD for OU3, which will focus
on ground water issues and which EPA has yet to issue.
RCRA Location-Specific Requirements
Location-specific ARAR's within RCRA are location standards
detailed at 40 CFR S 264.18 that are potentially applicable to
the siting of a new on-site TSD unit managing RCRA hazardous
waste as part of a remedial alternative.
These location standards are specified and addressed as
follows:
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• Seismic considerations restricting TSD facilities within 200
feet of a fault that has had a displacement within Holocene
time. Because the Vertac site is not located in
jurisdictions listed in Appendix VI of 40 CFR Part 264, such
an on-site facility would be in compliance with this
requirement as per 40 CFR § 270.14(b)(11).
• Flood plain considerations requiring TSD facilities located
within a 100-year flood plain to be designed, constructed,
operated, and maintained to prevent washout (the movement of
hazardous waste from the active portion of the facility as a
result of flooding) . Par*: of tho site contains portions of
the 100-year flood plain. Approximately 150 feet to the
east and west of Rocky Branch Creek are included within the
100-year flood plain.
• Salt dome formationsf salt bed formations, underground mines
and caves are locations where placement of non-containerized
or bulk liquid hazardous waste is prohibited. This
requirement is not applicable to the Vertac site because
these features are not located within the area of the site.
RCRA Action-Specific ARAR's
Action-specific ARAR's are usually technology or activity-
based requirements or limitations on actions taken with respect
to hazardous wastes. These requirements may be triggered by the
particular remedial action that is selected to accomplish the
selected alternative. Because there is more than one alternative
action for the OU2 media at the site, many different requirements
may be applicable.
General TSD Facility Requirements
General TSD facility requirements under RCRA apply to those
facilities that treat, store, or dispose RCRA hazardous wastes.
The requirements that could potentially be ARAR's at the site
include:
• General facility standards (40 CFR Part 264, Subpart B)
including those for waste analysis.
• Preparedness and prevention standards (40 CFR Part 264,
Subpart C) addressing facility design and operation and
required equipment.
• Contingency plan and emergency procedures (40 CFR Part 264,
Subpart D).
• Manifest system recordkeeping and reporting (40 CFR Part
264, Subpart E) to continuously track off-site hazardous
waste transport.
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• Releases from solid waste management units (40 CFR Part 264,
Subpart F) for new landfills, land treatment, and waste pile
units. This includes provision for ground water monitoring
programs.
• Closure and post-closure requirements (40 CFR Part 264,
Subpart G) requiring removal of waste and residuals to an
extent that controls, minimizes, or eliminates post-closure
release of hazardous constituents.
• Use and management of containers (40 CFR Part 264, Subpart
I) which provides standards for the condition of containers,
waste compatibility, inspections, LBorage building design
and construction, and closure.
• Landfills (40 CFR Part 264, Subpart N).
• Incinerators (40 CFR Part 264, Subpart 0).
Land Disposal Restrictions
The land ban, promulgated pursuant to RCRA Section 3004, 42
U.S.C. § 6924, on 7 November 1986 and codified at 40 CFR Part
268, Subparts A, C, and D, stipulates that no hazardous wastes
(as defined at 40 CFR S 261.31) may be land disposed unless
treated. RCRA requires that the treatment of wastes that are
subject to the ban on land disposal attain levels achievable by
the best demonstrated available technology (BOAT). BOAT requires
that a treated F-02X material have less than 1 ppb TCDD, as
measured by the Toxicity Characteristic Leaching Procedure (TCLP)
found at 40 CFR Part 261, App. II, prior to disposal in a RCRA-
permitted landfill.
The land disposal restrictions (LDR's) also apply to the
storage of certain hazardous wastes on-site. These restrictions
prohibit the on-site storage of "bannad" wastes for longer than l
year unless the owner/operator can prove that the extended
storage is solely for the purpose of accumulating enough waste
for proper treatment. Thus, all materials potentially subject to
LDR's that have been stored on-site and whose disposition is the
subject of this ROD have been accumulated in such a manner.
Conso1idation
As long as contaminated material remains within a CERCLA
Area of Contamination (AOC), EPA generally does not consider
placement to have occurred. See 55 Fed. Reg. 8760 (March 6,
1990). The Agency has codified that principal in the RCRA
corrective action regulations, such as the Corrective Action
Management Unit Rule, 58 Fed. Reg. 8658 (Feb. 16, 1993), which
generally may permit movement of contaminated material outside an
AOC for on-site handling or treatment without triggering
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placement and the associated LDR treatment and disposal
requirements.
For LDR's to be applicable requirements, EPA must first
determine whether consolidation activities considered or
contemplated at the Vertac site constitute placement. To assist
in defining when placement does and does not occur for CERCLA
actions involving on-site disposal of wastes, EPA uses the
concept of AOC's, which may be viewed as equivalent to RCP»
units, for the purposes of LDR applicability determinations. An
AOC is delineated by the areal extent of contiguous
contamination. Such contamination must be continuous, but may
contain varying types and concentrations of ^azardous substances.
Depending upon site characteristics, one or more AOC's may be
delineated.
Placement does not occur when wastes are consolidated within
a land-based unit, when they are treated in situ, when they are
left in place, or when they are moved within an AOC. See 55 FR
8666, 8758-8760 (March 8, 1990), and "Determining When Land
Disposal Restrictions (LDR's) Are Applicable to CERCLA Response
Actions," OSWER Directive 9347.3-O5FS (July 1989). Also see 61
FR 18804-18805 (April 29, 1996). Specifically, placement does
not occur when the wastes are consolidated within the AOC.
EPA considers the entire landmass of the Vertac site to be
contaminated due to the fact that TCDD levels in the soils found
on-site and on contiguous contaminated off-site areas exceed the
background TCDD level found in Jacksonville of 0.3 ppb or less.
Therefore, all consolidation actions contemplated in this ROD
that will apply to excavated on-site soils and debris, or to
soils and debris removed from areas contiguous to the site, are
within the AOC for purposes of determining the applicability of
LDR's due to the fact that TCDD concentrations withi^ the AOC and
contiguous contaminated areas exceed background TCDD
concentrations by substantial orders of magnitude. Thus, during
the on-site consolidation activities, materialr will be
consolidated within the AOC, and therefore, the land disposal
restrictions are not applicable.
However, if the materials are treated on-site within the AOC
in a manner that would constitute "treatment" as that term is
defined at RCRA Section 1004(34), 42 U.S.C. S 6903(34), and then
redeposited within the AOC such as in the consolidation unit,
then placement has occurred and the land disposal restrictions
apply, unless a treatability variance under 40 CFR S 268.44 is
obtained, or unless the ARAR is waived under CERCLA Section
121(d)(4)(A), 42 U.S.C. S 9621(d)(4)(A), and NCP Section
300.430(f)(1)(ii)(C)(l)f 40 CFR S 300.430(f)(1)(ii)(C)(1).
On July 18, 1996, the EPA Region 6 executed an Amended Non-
Time Critical Action Memorandum that, among other things, granted
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a treatability variance pursuant to 40 CFR S 268.44, of the 1 ppb
LDR treatment standard for dioxin-contaminated wastes set out at
40 CFR § 268.31, to allow the on-site disposal of treatability
residues from the on-site incineration of TCDD-contaminated
Vertac wastes. That treatability variance allows the on-site
disposal of Vertac site-related dioxin-contaminated materials,
such as some of the incinerator ash and possibly some shredded
pallets and incinerator salt residuals, that exceed the 1 ppb LDR
treatment standard but that fall below the 5 ppb alternative
treatment standard selected in the treatability variance section
of the Action Memorandum.
Therefore, should placement occur with respect to Vertac
TCDD wastes within the AOC, the treated materials cannot exceed
the 5 ppb TCDD alternate LDR treatment standard selected in the
July 18, 1996, Action Memorandum. In addition, EPA has
established LDR treatment standards for most of the hazardous
wastes associated with the Vertac site, but, as discussed above,
they will not be applicable where consolidation within the CCU
occurs since placement will not have occurred.
Finally, substantive, versus procedural, minimum technology
requirements (MTR's) are applicable for the CCU to be constructed
within an AOC, due to the fact that the CCU will be constructed
on-site, within the AOC.
Incinerators
Incineration of a RCRA hazardous waste is regulated under 40
CFR Part 264, Subpart O. These regulations include provisions
for:
• Conduct of a trial burn (40 CFR SS 270.19(b) and
270.62(b)(6^.
• Incinerator start up/shut down requirements (40 CFR S
264.345(d).
• Waste feed analysis (40 CFR SS 264.341 and 270.62(b)(2).
• Operating requirements (40 CFR S 264.345). This includes a
control of fugitive emissions either by keeping the
combustion zone totally sealed or maintaining a combustion
zone pressure lower than atmospheric pressure. In addition,
an automatic cutoff system must be provided to stop the
waste feed when operating conditions deviate from design
conditions.
• Monitoring and inspections (40 CFR S 264.347(a)). This
includes monitoring of the following operating parameters:
- Combustion temperature.
- Waste feed rate.
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- Combustion gas velocity.
- Carbon monoxide (CO) emissions.
• Closure with disposal of hazardous waste and residues,
including ash, scrubber water, and scrubber sludge (40 CFR §
264.351).
• Compliance with additional general TSD facility
requirements.
In addition, the regulacions set the following performance
standards for incineration at 40 CFR § 264.343 that require that
the incinerator:
• Achieves a destruction and removal efficiency (ORE) of
99.9999 percent (six 9's) for each principal organic
hazardous constituent (POHC) in the waste feed for F-02X
wastes. A ORE of 99.99 percent (four 9's) is required for
non-F-02X wastes. For F-02X wastes, the ORE must be
demonstrated on POHC's that are more difficult to incinerate
than tetra-, penta-, id hexachlorodibenzo-p-dioxins and
dibenzofurans. In addition, the owner or operator of the
incinerator must notify the Regional Administrator of his
intent to incinerate F-02X wastes.
• Reduces hydrogen chloride (HCl) emissions to 1.8 kg/hr or 1
percent of the HCl in the stack gas before entering any
pollution control device.
• Does not release particulate matter in excess of 180 mg/dscm
(milligrams per dry standard cubic meter), corrected for the
amount of oxygen in the stack gas.
The ability to meet these performance standards must be
demonstrated during the trial burn period.
Furthermore, as discussed above, monitoring of various
parameters during operation of the incinerator is required per 40
CFR S 264.347. These operating parameters include:
• Combustion temperature
• Waste feed rate
• An indicator of combustion gas velocity
• Carbon monoxide emissions
Finally, fugitive emissions must be controlled (40 CFR
364.345) either by:
• Keeping the combustion zone totally sealed.
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• Or maintaining a combustion zone pressure lower than
atmospheric pressure.
The EPA has Standards for Owners and Operators of Hazardous
Waste Incinerators (40 CFR Parts 260, 261, 264, and 270). The
standards establish risk-based emission limits for individual
toxic metals (Appendix VIII of 40 CFR Part 261). The EPA also
regulates hydrochloric acid (HC1) emissions using the same risk-
based approach proposed for metals. The limits are back -
calculated from ambient levels that the EPA believes pose an
acceptable health risk. To simplify this process, the EPA has
developed conservative screeniry limits based on terrain and
effective stack height. If the screening limits are not
exceeded, the Agency has determined that emissions do not pose
unacceptable risk. If the screening limits are exceeded,
however, site-specific dispersion analysis is required to
demonstrate that emissions will not result in an excecdance of
acceptable ambient levels. The risk-based controls are applied
on a case-by-case basis to ensure that the existing technology-
based standard is protective.
Existing regulations control organic emissions by the ORE
standard in 40 CFR S 264.343(a). This standard limits stack
emissions of POHC's to 0.0001 percent (for dioxin-containing
waste) of the quantity of the POHC fed into the incinerator. The
standard considers a POHC to be destroyed (or removed in ash or
scrubber water) if it is not present in the stack emissions.
Given that stack gas carbon monoxide (CO) is a conventional
indicator of combustion efficiency and a conservative indicator
of combustion upsets (i.e., poor combustion conditions),
emissions to a 3e minirois level (100 ppmv - parts per million by
volume) ensures high combustion efficiency an^ "'.ow unburned
hydrocarbon emissions. The owner or operator would be required
to demonstrate that higher CO levels would not result in high
hydrocarbon emissions, in cases where che CO limit is exceeded.
Delisting
If residues from treatment are delisted, they are no longer
considered to constitute RCRA hazardous wastes, and the wastes
could be placed in any landfill permitted to receive non-RCRA
hazardous solid waste. Delisting of the material would involve
petitioning the EPA Regional Administrator of Region 6 to remove
the site-specific waste from the list of RCRA hazardous wastes
and to consider it nonhazardous. The petition must state the
need and justification for the delisting, and it must include
supportive documentation that demonstrates to the Administrator
why the material does not meet any of the criteria under which
the original waste was listed. A rotary kiln was used to
incinerate wastes from the Vertac site at the U.S. EPA Combustion
Research Facility (CRF) in Jefferson, Arkansas as a pilot
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project. Scrubber brines and ash generated in that pilot burn
have been delisted by the U.S. EPA (Federal Register Vol. 54, No.
71, 14 April 1989). A similar delisting procedure would be
required for any F-Listed materials treated at the site prior to
disposal in a landfill not permitted to accept these F-listed
wastes.
Hazardous Waste Landfills
The technical requirements for an on-site consolidation unit
may, but are not required to, be considered as relevant and
appropriate certain design guidance (such as requirements for
such things as covers/caps, drainage, liners, stability)
pertaining to RCRA-permitted facilities. RCRA-specific
requirements for a hazardous waste landfill are found at 40 CFR §
264.300 (Subpart N), which could be considered for a
consolidation unit. These requirements would be applicable to an
on-site containment unit if residues from treatment were to be
put into the unit without delisting. 40 CFR S 264.301 states
that a RCRA landfill must have two or more liners that are
designed, constructed, and installed to prevent migration of
wastes out of the landfill to the adjacent soil or subsurface
soil or ground water during the active life of the landfill.
Other liner system requirements include:
• Construction with materials that have appropriate chemical
properties and sufficient strength to prevent failure.
• Placement upon a base capable of providing support to the
liner.
• Installation to cover all earth likely to be in contact with
the waste or leachate.
Furthermore, leachate collection systems are required above
and between the liners that are designed, constructed,
maintained, and operated to collect and remove any leachate from
the landfill. For a RCRA landfill, the leachate collection and
removal systems must be:
• Chemically resistant to the waste managed or leachate
expected in the landfill.
• Of sufficient strength and thickness to prevent collapse
under the pressure exerted by the overlying waste.
• Designed and operated to prevent clogging through the
scheduled closure of the landfill.
Furthermore, RCRA presents specific requirements for F-02X
wastes. In order to place F-02X wastes into a landfill, the
landfill must be operated in accordance with a management plan
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for these wastes that is approved by the Regional Administrator
(40 CFR S 264.317). Approval of the management plan would be
based on the following factors:
• The volume, physical, and chemical characteristics of the
waste, including migration potential.
• The attenuative properties of the underlying and surrounding
soils.
• The effectiveness of additional treatment, design, or
monitoring requirements.
Finally, RCRA also presents monitoring, inspection,
surveying, record-keeping, closure, and post-closure care
requirements (40 CFR SS 264.303 - 264.310), and general facility
management requirements.
A RCRA-equivalent consolidation/containment unit (CCU) will
be constructed on-site as part of the remediation for OU1 for on-
site disposal of demolition debris. The CCU will be designed to
meet substantive RCRA requirements, and it will be designed to
contain adequate capacity to hold whatever volumes of
contaminated soil and debris this ROD may propose to consolidate
within that CCU, which will lie within the AOC.
Treatment Standards for Hazardous Debris
Treatment of hazardous debris is required if the debris is
to be land disposed, assuming that the debris does not remain
within the CERCLA area of contamination (AOC). As discussed
earlier, as long as contaminated material remains within a CERCLA
Area of Contamination (AOC), EPA generally does not consider
placement to have occurred. See 55 Fed. Reg. 8760 (March 6,
1990). RCRA corrective action regulations, such as the
Corrective Action Management Unit Rule, 58 Fed. Reg. 8658 (Feb.
16, 1993), may permit movement of contaminated material outside
an AOC for on-site handling or treatment without triggering
placement and the associated LDR treatment and disposal
requirements. However, where "placement" does occur, debris must
be treated using the technology or technologies identified in
Table 1 of 40 CFR S 268.45, or the waste-specific treatment
standards for the waste contaminating the debris.
In addition, 40 CFR S 268.44 allows EPA to apply alternative
treatment standards under the Land Disposal Restrictions (LDR's)
found at 40 CFR Part 268 where best demonstrated available
technology (BOAT) treatment standards are in effect, but where
resort to the waste-specific BOAT LDR treatment standard is not
appropriate for the treatment of the waste in question. The
National Contingency Plan (NCP), 40 CFR Part 300, has expressly
approved, on a site-by-site basis, the use of the LDR
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treatability variance for CERCLA response actions involving
contaminated soil and debris. See preamble to the NCP at pages
8761 and 8762, 55 Fed. Reg. 8761 and 8762, March 8, 1990.
In general, the treatment standards for hazardous debris are
not applicable if the OU2 debris (i.e. . manholes, sumps, sewers,
and foundations) is consolidated and not land disposed. If this
debris is managed in place, the hazardous debris standards may be
relevant and appropriate.
Clean Watar Act (CWA)
The Clean Water Act (CWA) , 3J U.S.C. S 1251 et sea. .
required EPA to establish regulations to protect the quality of
surface waters across the nation. The CWA may be applicable to
treatment and discharge of water used as part of a remedial
action where the treatment and discharge occurs on-site. For any
off -site discharges, both procedural and substantive CWA
requirements would apply. "On-site" discharges should meet
substantive requirements but are exempt from federal, state and
local permitting requireme. s. See CERCLA Section 121(e)(2), 42
U.S.C. S 962l(e)(2), and 40 CFR 300.400(e). A discharge of
CERCLA wastewaters is considered "on-site" if the receiving water
body is in the area of contamination or is in very close
proximity to the site and is necessary for the implementation of
the response action (even if the water body flows off-site) .
Under the CWA, three interrelated areas were identified for
regulation:
• Establishment of water quality standards;
• Establishment of storm water runoff control; and
• Establishment of effluent standards (discharge limitations)
intended to ensure compliance with applicable water quality
rtandards .
Water quality standards represent chemical-specific
requirements, while storm water runoff controls and effluent
standards are action-based requirements. Each is addressed
separately below.
Chwaical-Spttcif ic
Water Quality Criteria (WQC)
CERCLA Section 121(d) (2) (A) , 42 U.S.C. S 9621 (d) (2) (A) ,
states that remedial actions shall attain Federal water quality
criteria where they are relevant and appropriate under the
circumstances of the release or threatened release. Water
quality criteria are non-enforceable guidance developed under the
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Clean Water Act (CWA) Section 304, 33 U.S.C. S 1314, but are used
by the state, in conjunction with a designated use for a stream
segment, to establish water quality standards under CWA Section
303, 33 U.S.C. § 1313. In determining the applicability or
relevance and appropriateness of water quality criteria, the most
important factors to consider are the designated uses of the
water and the purposes for which the potential requirements are
intended. Water quality criteria have been developed based on:
• Protection of human health. These levels have been
developed based on two separate potential exposure pathways.
The first criterion is based solely on consumption of fish,
while the second criterion considers both consumption of
fish and consumption of water.
• Protection of aquatic life. These levels have been
developed based on acute toxicity and chronic toxicity
effects to aquatic organisms.
Whether a water quality criterion is appropriate and which
form of the criterion is appropriate depends on the likely
route(s) and receptors of exposure.
Action-Specific Requirements
Storm Water Runoff Control
The EPA has issued regulations setting forth the NPDES
permit application requirements for discharges of storm water
from industrial activities (40 CFR 122, 123, and 124). An NPDES
permit is required for all discharges of storm water from
industrial activities as defined in the November 1990
regulations, as amended. In states which hav vaen granted NPDES
permitting authority by the EPA, all NPD^S permits are issued and
administered by the state regulatory agency. The ADPC&E has been
granted authority over the NPDES program. The requirements of
the s^ate NPDES program are discussed in Subsection 2.3.3.
However, for all on-site discharge activity, only substantive,
versus procedural (such as obtaining a permit), is required. See
CERCLA Section 121(e)(2), 42 U.S.C. S 9621(e)(2).
As a result of previous on-site remedial actions, the
central process area is surrounded by a series of five concrete-
lined drainage ditches and collection sumps. During a storm
event the drainage ditches divert run-off to the sumps. The
initial sump volume (first flush) for each of the five sumps is
diverted to the on-site treatment plant. Overflow from the sumps
currently discharges to Rocky Branch Creek without treatment.
Therefore, after soils remediation is complete, Hercules, Inc.
will develop a storm water management plan called a Storm Water
Pollution Prevention Plan (SWPPP) to address, in part,
elimination or significant reduction of the sump overflows and
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develop management controls for storm events. The SWPPP will be
developed in accordance with criteria contained in EPA's Final
National Pollutant Discharge Elimination System Storm Water
Multi-Sector General Permit for Industrial Activities. (60 FR
50804)
Direct Discharge of Treatment System Effluents
Direct discharge of wastewaters to a surface water is
governed by tlie NPDES permitting requirements. 40 CFR Parts 122,
125, and 129 as applicable to point source discharges to waters
of the United States, which reruire:
• The use of the Best Available Technology (BAT) economically
achievable to control toxic and nonconventional pollutants.
• Use of best conventional control technology (BCT) is
required to control conventional pollutants. Technology-
based limitations may be determined on a case-by-case basis.
• 40 CFR S 122.44 and state regulations approved under 40 CFR
Part 131 require compliance with applicable Federally-
approved state water quality standards. These standards
may be in addition to or more stringent than other Federal
standards under the CWA.
• 40 CFR S 122.44(e) requires that discharge limitations must
be established at more stringent levels than technology-
based standards for toxic pollutants.
• 40 CFR S 125.100 requires that Best Management Practices
(BMP) be developed and implemented to prevent the release of
toxic constituents to surface waters.
• 40 CFR S 122.41(i) requires that discharges must be
monitored to assure compliance. The discharger will
monitor the mass of each pollutant, the volume of effluent,
and the frequency of discharge and other measurements as
appropriate.
The direct discharge requirements may be applicable if
waters generated during the remediation are discharged to Rocky
Branch Creek. ADPC&E has established discharge limitations which
would apply to the site wastewaters if they are discharged to
Rocky Branch Creek. Water generated during OU2 and as a result
of perpetual operation and maintenance will need to be treated to
meet applicable water-quality based, effluent discharge limits.
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The Clean Air Act (CAA), 42 U.8.C. S 7401 et sea.
The Clean Air Act (CAA) and the 1990 CAA Amendments required
EPA to establish regulations to protect ambient air quality. In
response to this mandate, the EPA directed the following:
• Establishment of National Ambient Air Quality Standards
(NAAQS).
• Establishment of maximum emission standards as expressed
under the National Emission Standards for Hazardous Air
Pollutants (NESHAP). These standards apply to emissions
from specific sources, and do not constitute an ARAR for
activities that are expected to take place at the Vertac
site.
• Establishment of maximum emission standards as expressed
under the New Source Performance Standards (NSPS).
Chemical-specific Requirements
National Ambient Air Quality Standards
National Ambient Air Quality Standards (NAAQS) (40 CFR Part
50) have been developed by the EPA for seven classes of
pollutants: Particulates, sulfur oxides, nitrogen oxides,
hydrocarbons, oxidants (ozone), carbon monoxide, and lead. The
NAAQS focus on two levels of control: Primary and secondary.
The primary standards apply exclusively to the protection of
human health, while the secondary standards are set to protect
welfare, including wildlife, climate, recreation, transportation,
and economic values. A listing of NAAQS primary and secondary
standards i ; included in 40 CFR Part 50. The NAAQS specify
maximum primary and secondary 24 hour concentrations for
particulate matter in the ambient air. These ambient sir
concentrations are not designed to apply to specific sources;
rather, states may promulgate State Implementation Plan (SIP)
emission limits applicable to sources, which will result in
attainment and maintenance of the NAAQS. While not ARAR's, NAAQS
provide guidance with respect to appropriate levels of
particulate airborne emissions.
It should be noted that these standards are not emission
(i.e.. discharge) standards, but are standards to be met for the
ambient air, after allowing for mixing of the particular
discharge with the ambient air. NAAQS attainment requirements
are applicable only to "major sources," which are pollutant-
specific, or sources which emit 10 tons/year of a single
regulated hazardous air pollutant (HAP) or 25 tons/year of any
combination of regulated pollutants (HAP's). The definition of
"major sources" is also dependent on the local attainment
classification. Pulaski County, Arkansas, is designated as an
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ozone maintenance area, and therefore a "major source" is defined
as any source with the uncontrolled potential to emit 100
tons/year of volatile organic compounds (VOC's).
State Implementation Plans (SIPs) are developed by
individual states and contain the actual abatement requirements
necessary to achieve compliance with the NAAQS.
Ambient air monitoring during remediation may be part of the
selected remedial action for OU2. Perimeter air samplers and
real-time ambient air monitors may be used to monitor ambient air
quality on-site. Particulates would be the NAAQS contaminant of
greatest concern on-site if soil excavation is required.
Engineering controls would be necessary if particulate
concentrations in ambient air become a concern. VOC emissions
would be the NAAQS contaminant of concern if incineration were
part of a remedial action.
Action-Specific Requirements
New Source Performance Star'irds (NSPS)
NSPS regulations found at 40 CFR Part 60 have been
promulgated to cover particulate discharges from a number of
different types of facilities, including incinerators.
Incineration regulations are listed under 40 CFR Part 60, Subpart
E, Standard of Performance for Incinerators. The operating
standard found at 40 CFR S 60.52 is that the discharge of
particulate matter shall not exceed 180 mg/dscm (milligrams per
dry standard cubic meter), corrected to 12% C02. This provision
applies to incinerators with a charging rate exceeding 50 metric
tons per day. It should be noted that this performance standard
for particulate matter matches that listed under the RCRA
regulations for incinerators found at 40 CFR Parts 264 and 270.
If the treatment process selected for OU2 has a charging
rate exceeding 50 tons per day, the NSPS may be applicable.
However, the particulate standard stated above should be easily
attained using commercially available air pollution control
equipment.
7.2.2 STATE ARAR'S
Regulation No. 2; Water Quality Standards for Surface Waters
Pursuant to the Arkansas Water and Air Pollution Control Act
(AWAPCA), ACA 8-4-101 - 106, 8-4-201 - 229, and 8-4-301 - 313,
and in compliance with the requirements of the Federal Water
Pollution Control Act, the State of Arkansas has developed water
quality standards for all surface waters, interstate and
intrastate. Established water quality standards are based upon
present, future, and potential uses of the surface waters of the
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state and criteria developed from statistical evaluations of past
water quality conditions and a comprehensive study of least-
disturbed, ecoregion reference streams. The standards are
designed to enhance the quality, value, and beneficial uses of
the water resources of the state; aid in the prevention, control,
and abatement of water pollution; provide for the protection and
propagation of fish and wildlife, and; provide for recreation in
and on the water.
General standards for color, taste and odor, solids, toxics,
and oil/grease have been developed. In addition, specific
standards for temperature, turbidity, pH, dissolved oxygen,
radioactivity, bacteria, toxics, nutrients, oil/grease, and
mineral quality have been developed depending on the individual
ecoregions within the state. The site is situated within the
Arkansas River Valley Ecoregion.
Water quality standards relate to the existing on-site
treatment plant and its off-site discharges. As part of OU2,
the existing treatment plant may be utilized to treat collected
storm water and wastewaters generated as part of the remediation.
Although the existing treatment plant currently discharges to a
local Publicly-Owner Treatment Works (POTW), discharge
limitations for discharge to Rocky Branch Creek have been
proposed by ADPC&E.
Regulation 3; Certification of Wastewater Utilities Personnel
Operators in responsible charge of wastewater treatment
facilities are required to be licensed and certified by ADPC&E in
order to safeguard the public health and protect the waters of
the state from pollution. Certification typically includes
training, classifying, and licensing of treatm t plant
operators.
Regulation 6; State Administration of the National Pollutant
Discharge Elimination System (NPDES)
The technical, versus procedural, requirements of an NPDES
permit may apply if wastewaters generated at the site are
directly discharged off-site into Rocky Branch Creek. Further,
the technical, versus procedural, requirements of a storm water
permit may apply if storm water discharges associated with the
site remedial activities that involve disturbing more than five
(5) acres are discharged off-site to Rocky Branch Creek. An
individual NPDES permit may be issued by the ADPC&E, or general
permit coverage may be obtained under the Department's General
NPDES Permit No. ARROOAOOO. Obtaining NPDES coverage for off-
site storm water discharges requires submission of an individual
application, or Notice-of-Intent (NOI), development and
implementation of a Storm Water Pollution Prevention Plan, and
possibly storm water sampling and monitoring.
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The existing treatment plant on-site may be used to treat
wastewaters generated as part of the OU2 remediation. Currently
this treatment plant discharges to a local POTW in accordance
with a previous permit. However, as part of the off-site
remedial action, the treated effluent will go to Rocky Branch
Creek. The system will allow compliance with discharge
limitations which have been proposed to control the discharge to
Rocky Branch Creek.
Regulation 23; Hazardous Waste Management Code
The Arkansas Hazardous Waste Management Act of 1979 and the
Arkansas Resource Reclamation Act of 1979 are known together as
the Arkansas Hazardous Waste Management Code (amended June 1992),
ADPC&E Reg. No. 23. This code resembles the federal hazardous
waste management regulations promulgated under RCRA. The
Arkansas Hazardous Waste Management Code does contain siting
criteria (Section S) for a hazardous waste management facility.
Such a facility may not be sited in the following areas:
• An active fault zone.
• A "regulatory floodway" as adopted by communities
participating in the National Flood Program.
• A 100-year flood plain.
• A recharge zone of sole source aquifer designated pursuant
to the SDWA.
• Wetlands areas that are inundated or saturated by surface
water or ground water.
In addition, no permit shall be issued for a hazardous waste
landfill facility or surface impoundment if such a facility is
located in the following areas:
• Areas of high earthquake potential.
• Areas having a soil that would be classified as vertisol.
• Areas in which a stratum of limestone or similar rock of an
average thickness of more than 1 meter lie within 30 meters
of the base of the proposed liner system.
• Areas in which the liner bottom or in-place barrier soil is
less than 10 feet above the historically high water table.
• Areas near a functioning private or public water supply that
would constitute an unacceptable risk to the public health
or safety.
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• Areas one-half mile from any occupied dwelling, church,
school, hospital, or similarly occupied structure.
• Areas where the active portion of the facility is less than
200 feet from the facility's property line, and less than
300 feet from right-of-ways for roads and utilities.
Section 13 of the Code includes performance standards in
addition to the provisions of
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• Water Table - Landfill operations will maintain a safe
vertical distance between deposited refuse and the maximum
seasonal water table elevation and shall include such
measures necessary to prevent contamination of the ground
water.
• Flooding - sites subjected to flooding shall be avoided.
• Site Improvements - The following physical improvements
shall be made before a landfill site is placed in operation:
The Site shall be adequately fenced, with an entrance gate
that can be locked and posted; all-weather operational roads
shall be provided, and; arrangements shall be made for fire-
protection services.
• Operation - All operations of the landfill shall be in
accordance with the approved plans and the Arkansas Solid
Waste Management Code.
The consolidation/containment unit (CCU), which is a
component of many alternatives for OU2 media, will be designed
and constructed as part of OU1. Therefore, while those siting
criteria discussed above are applicable, they have been addressed
in the ROD for OU1, under which authority the CCU's siting will
be addressed.
Arkansas Water and Air Pollution Control Act (AWAPCA)
Subchapter 2 of the AWAPCA, ACA 8-4-101 - 106, 8-4-201 -
229, and 8-4-301 - 313, (relating to water pollution) provides
the Arkansas Pollution Control and Ecology Commission the
authority to prescribe:
• Effluent standards specifying the maximum amounts or
concentrations and nature of the contaminants being
discharged into the waters of the State of Arkansas or into
POTW's.
• Requirements and standards for equipment and procedures for
monitoring contaminant discharges at their sources.
• Water quality standards, performance standards, and
pretreatment standards.
In compliance with the requirements of Federal Water
Pollution Control Act, the Arkansas Commission on Pollution
Control and Ecology has established water quality standards for
all surface waters, interstate and intrastate, of the State of
Arkansas.
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Arkansas air pollution control regulations (ACA Subchapter
3) resemble the national standards set forth by the EPA under the
CAA, but require preconstruction review by the State. Section 5
of the Arkansas Air Pollution Control Regulations outlines
specific limitations for particulate emissions and for visible
emission from new or modified sources. Particulate emission
limits are based on the rate of material being processed (Ib/hr),
visible emission standards are action specific.
Regulations 18 and 26: Arkansas Air Pollution Control Code
The Arkansas Air Pollution Control Code (Minor Source,
ADPC&E Reg. No. 18), (Operating Air Perr-. Program, ADPC&E Reg.
No. 26) was derived from the AWAPCA and outlines permit
requirements, and emission limits for small or nuisance sources
not covered by the SIP. Of particular interest are Section 4 -
Visible Emissions; Section 6 -Emission of Particulate Matter from
Incinerators; Section 7 - Emission of Particulate Matter from
Equipment; Section 8 - Emission of ^articulate Sulfur Compounds;
Section 10 - Emission of Air Contaminants Such as to Constitute
Air Pollution; and Section 11 - Control of Fugitive Emissions.
Regulation 19; Arkansas State Implementation Plan for Air
Pollution Control
Promulgation and enforcement of the SIP (Regulation No. 19,
September 1993) is necessary for the attainment and maintenance
of the National Ambient Air Quality Standards (NAAQS)(40 CFR Part
50), New Source Performance Standards (NSPS)(40 CFR Part 60),
Prevention of Significant Deterioration (PSD)(40 CFR S 52. 21),
and the National Emissions Standards for Hazardous Air Pollutants
(NESHAP) (40 CFR Part 61). The SIP is formatted into the
fallowing sections:
• Protection of the National Ambient Air Quality Standards;
• Applicability, Permitting Procedure;
• General Emissions Limitations Applicable to Equipment;
• Upset Conditions, Revised Emissions Limitations;
• Sampling, Monitoring, and Reporting Requirements;
• Prevention of Significant Deterioration Supplement;
• lll(d) Designated Facilities; and,
• Regulations for the Control of volatile organic compounds
(VOC's).
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The SIP was developed primarily to satisfy the requirements
of the Clean Air Act.
Arkansas Non-criteria Air Pollutants Control Strategy
ADPC&E has implemented an evaluation of the emissions of
non-criteria air pollutants from all sources in order to
determine if a permit should be issued or if an existing source
should be required to retrofit control equipment. The No-
criteria Air Pollutants Control Strategy (NAPCS) allows
applicants to apply a 3 level evaluation of the emission source.
The three levels are as follows:
• Level 1 Analysis - This analysis is based upon Threshold
Limit Values (TLV's) for chemical substances adopted by the
American Conference of Governmental Industrial Hygienists
(ACGIH). According to NAPCS, the predicted ambient air
concentration of gases and vapors is considered acceptable
if it is less than 1/100 of the ACGIH TLV. The ambient
concentration is determined by using appropriate atmospheric
dispersion models over a 24-hour average. The spacing
between receptors used in the model is 100 meters (in the
area of the highest concentration). The NAPCS may consider
8 and 24-hour averages, first highs, as well as annual
averages for use in assessing risk.
TLV's have been established for the following OU2-related
site compounds:
Compound TLV
2,4-D 10 mg/m3
2,4,5-T 10 mg/m3
When the substance emitted is a particulate compound and
persistence in the environment is expected, the predicted annual
average concentration is considered acceptable if it does not
exceed the dosage mass of the lethal dose 50 (TD50) (or where 50%
of a study species dies upon exposure to a specific dosage)
expression divided by 10,000.
If the substance emitted is an herbicide, pesticide, or
fungicide, the recommended application rate (in pounds/m2) is
divided by 30,000 to obtain the maximum allowable 24 hour average
ambient concentration.
• Level 2 Analysis - If the source fails the Level 1 analysis,
the applicant must demonstrate it is using control
techniques equivalent to lowest achievable emission rate
(LAER) and submit toxicological and/or other data sufficient
to demonstrate the ground level concentration predicted in
Level 1 will not adversely affect the public's health or
welfare.
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• Level 3 Analysis - If the applicant is unable to
successfully demonstrate acceptance under Level 1 or 2
analyses, then more appropriate mathematical models (using
site-specific information), or ambient air monitoring can be
performed. Information gathered during Level 3 analysis is
then plugged back into the Level 1 and/or 2 analysis to
determine acceptance.
The substantive component zl NAPCS may be applicable to
remedial actions performed on-site. A site-wide air monitoring
program may be required to ensure compliance with this control
strategy.
Arkansas State Ground Water Quality Protection Strategy
The objective of Arkansas' ground water strategy is to
formulate and recommend a management program to protect the
quality of ground water resources.
Arkansas' Ground Water Quality Protection Strategy outlines
water quality criteria for ground water (drinking water) within
the State. Arkansas has adopted the recommended standards for
drinking water set by the SDWA. The Arkansas Department of
Health uses the National Primary Drinking Water Standards in
setting the criteria to which public water supplies must adhere.
The Arkansas State Ground water Quality Protection Standard
is not directly applicable to OU2 media, but may be indirectly
relevant as a result of the migration of site-related compounds
migrating from OU2 media into ground water.
7.2.3 TO-BE-CONSIDERED (TBC's)
City of Jacksonville Ordinances 604. 620. 684. and 877
Ordinance No. 620 sets forth uniform requirements for direct
discharge and indirect contributors into the wastewater
collection and treatment system for the City of Jacksonville,
Arkansas, and enables the City to comply with all applicable
state and Federal laws required by the CWA and its General
Pretreatment Regulations (40 CFR Part 403).
Ordinance No. 684 is an ordinance amending Ordinance No.
620 that specifically lists additional chemical-specific
pollutant limitations for contributors into the wastewater and
treatment system for the City of Jacksonville.
Ordinance No. 877 is an ordinance that amends Ordinances 620
and 684, specifying that no industrial user shall discharge
wastewater of sufficient strength to cause the 24-hour loading to
the POTW to exceed background levels by more than those
specified, under this ordinance, for selected chemicals.
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Ordinance No. 604 is an ordinance regulating the
Jacksonville sewer system and sets forth requirements and
regulations for the use of public sewers and private sewage
disposal.
8.0 SUMMARY OF COMPARATIVE ANALYSIS OP ALTERNATIVES
EPA is required to analyze each of the individual
alternatives against a set of 9 criteria and develop a
comparative analysis that focuses upon the relative performance
of each alternative against those criteria.
The nine evaluation criteria are as follows:
1. Overall Protection of Public Health and the Environment
This criterion addresses the way in which a potential remedy
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 may be through engineering
controls, treatment techni^es, or other controls such as
restrictions on the future use of the site. Total elimination of
risk is often impossible to achieve. However, a remedy must
minimize risk to assure that human health and the environment
would be protected.
2. Compliance with ARAR's
Compliance with ARAR's, or "applicable or relevant and
appropriate laws and regulations," assures that a selected remedy
will meet all related federal, state, and local requirements.
The requirements may specify maximum concentrations of chemicals
that can remain at a site; design or performance requirements for
treatment technologies; and, restrictions that may limit
potential remedial activities at a site because of its location.
3. Long-Term Effectiveness or Permanence
This criterion addresses the ability of a potential remedy
to reliably protect human health and the environment over time,
after the remedial goals have been accomplished.
4. Reduction of Toxicity, Mobility, or Volume of Contaminants
This criterion assesses how effectively a proposed remedy
will address the contamination problems. 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.
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5. Short-Term Effectiveness
This criterion addresses the time factor. Technologies
often require several years for 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 the remediation.
6. Implemantability
Implementability addresses the ease with which a potential
remedy can be put in place. Fact-rrs such as availability of
materials and services are considered.
7. COSt
Costs (including capital costs required for design and
construction, and projected long-term maintenance costs) are
considered and compared to the benefit that will result from
implementing the remedy.
8. State Acceptance
The State of Arkansas has had an opportunity to review the
FS, the Proposed Plan and the ROD, and offer comments to EPA.
The State of Arkansas fully supports EPA's preferred alternative.
9. Community Acceptance
During the public comment period, interested persons and
organizations have commented on the alternatives. EPA has
carefully considered these comments in making its final
selection. The comments received in response ~ EPA's initial
Proposed Plan for OU2, issued in May 1995, are addressed in a
document called "The Original Responsiveness Summary," which was
released to the public on March 5, 1996, when EPA issued its
Supplemental Proposed Plan for OU2, and is included as Attachment
A as part of this Record of Decision. EPA received additional
formal and informal comments following the release of the
March 5, 1996, Supplemental Proposed Plan, and these comments are
addressed in "The Supplemental Responsiveness Summary" which is
included as Attachment B to this ROD. For additional information
on community participation, refer to Section 3.0 of this
document.
The nine criteria are categorized into three groups:
Threshold criteria, primary balancing criteria, and modifying
criteria. The threshold criteria must be satisfied 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 public comment is received on the Proposed Plan.
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Threshold Criteria
• Overall protection of human health and the environment.
• Compliance with ARAR's (applicable or relevant and
appropriate requirements of other Federal and State
environmental statutes).
Primary Balancing Criteria
• Long-term effectiveness and permanence.
• Reduction of toxicity, mobility, and volume through
treatment.
• Short-term effectiveness.
• Implementability.
• Cost.
Modifying Criteria
• State acceptance.
• Community acceptance.
8.1 COMPARATIVE ANALYSIS OF REMEDIAL ALTERNATIVES
1. Overall Protection of Human Health and the Environment
Alternative S-l (no action), does not provide adequate
protection of human health and the environment. Alternatives S-2
through S-8 do not provide for adequate protection — human
health and the environment when considering the proposed TCDD
cleanup standards of 50 ppb, 35 ppb, and 20 ppb presented in the
FS (see EPA risk evaluation of soil cleanup levels for 2,3,7,8-
TCDD at the Vertac Superfund site). EPA has determined that a 5
ppb action level, based on site-specific risk factors for TCDD
TEQ, is necessary to be protective of a future on-site
unprotected worker exposure scenario. However, in examining the
protectiveness of Alternatives S-2 through S-8 the following
comparisons were made:
Alternatives S-2 through S-8 pose varying degrees of
potential short term risk during the construction phase of the
remedial actions associated with the various alternatives
proposed. Those short term risks will be addressed in greater
detail in Section 8.1.5, "Short-Term Effectiveness," below.
However, through appropriate health and safety measures and
proper engineering controls that would be implemented in
connection with any of the alternatives, adequate protection
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would be provided to the community and the workers during the
remedial actions.
However, containment of the low level risk media addressed
in this ROD, particularly when a 5 ppb cleanup level is applied
to the on-site consolidation remedy proposed in Alternative S-2,
will be fully protective of the human health and the environment.
Containment of low level threat wastes within a properly
engineered RCRA-compliant hazard-
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However, the long term benefits associated with these
alternatives are offset by the additional short term risks posed
by material handling associated with on-site desorption or with
material handling and transportation to an off-site incineration
facility, as well as substantial additional costs associated with
implementing Alternatives S-5 and S-6.
Alternative U-l (no further action with respect to equipment
and underground utilities), would not provide adequate protection
to the human health and the environment. Potential risks would
continue at current conditions for an extended period of time.
Alternatives U-2 (equipment plugging and cleaning) and U-3
(equipment plugging, cleaning and sealing) would provide overall
protection to the human health and the environment due to the
fact that both would substantially remove sources of future
contamination. However, Alternative U-3 provides a greater
degree of overall human health and environmental protection by
sealing off the cleansed and flushed equipment, sewer lines and
curbs and foundations, further ensuring that those objects not be
a source of future recontamination.
2. Compliance with Applicable or Relevant and Appropriate
Requirements (ARAR's)
At present there are no State or Federal regulations that
are applicable to Alternative S-l (no action), although this
alternative is not protective of human health. Land disposal
restrictions (LDR's) are not applicable to consolidated or
containerized soils for the on-site landfilling component of
Alternatives S-2 through S-8, as they would be consolidated
within an area of containment (AOC) without treatment, and
therefore placement will not occur. See discussion of
consolidation within Section 7.2.1, Federal ARAR's. For
alternatives S-3 through S-6, thermally-treated soils would need
to comply with land disposal restrictions prior to on-site
disposal due to the fact that placement would occur with respect
to treated wastes, as opposed to untreated contaminated soil and
debris. Treatment and disposal of TCB spill-related material
would comply with all applicable requirements with respect to
pre-transportation and manifesting requirements. Because TCB
spill-related materials above a 500 ppm action level would be
treated and disposed of off-site, further ARAR's analysis is
inapposite, and all applicable requirements would apply once the
material leaves the site.
Leachate collected from the on-site landfill in Alternatives
S-2 through S-8, and condensed water from Alternative S-3, would
be treated at the on-site treatment system, and the resulting
discharge to Rocky Branch Creek would have to meet
treatment/discharge requirements. Organic condensate generated
from on-site thermal desorption in Alternative S-5 would be
transported off-site for incineration, and would have to be in
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compliance with appropriate incineration and disposal
requirements.
Off-site transportation of crystalline TCB and associated
spill soils in Alternatives S-2 through S-6 and desorbed liquids
generated in Alternative S-5 would comply with all applicable
manifesting and transportation regulations.
Alternatives U-2 and U-3 would comply with ARAR's. The LDR
treatment standards for hazardous debris are not applicable to
underground structures such as manholes, sumps, and sewers
because the proposed actions do not involve placement within a
unit, and therefore land disposal will n^v. have occurred.
However, RCRA treatment and disposal requirements are applicable
to the wastewater generated during the remedial actions.
Wastewater generated from flushing of the industrial sewer, and
from hydroblasting of foundations and curbs, would be treated at
the on-site treatment plant in compliance with applicable
treatment and standards, and the treated water would be
discharged into Rocky Branch Creek in compliance with applicable
State water quality standards. Solids removed from the sewer
lines or removed from foundations and curbs would be placed in
the on-site consolidation unit. Because those solids constitute
contaminated debris from within the site's AOC, placement will
not occur when they would be consolidated within the CCU, and
therefore RCRA's LDR's do not apply as an ARAR.
3. Long-Term Effectiveness and Permanence
Alternative S-l (no action) does not provide for long-term
protection. Alternative S-2 (on-site containment), S-7 (capping
in place), and S-8 (on-site containment of site media with dioxin
concentrations above 50 ppm) provide for the r "action in the
migration and exposure pathways through capping and/or
landfilling contaminated soils. As discussed earlier,
containment of low level threat wastes in a RCRA Subtitle C
hazardous waste landfill has proven to be an effective and
reliable technology, but one that requires long term operation
and maintenance (O & M) and the imposition of institutional
controls to remain effective. Alternatives S-3 and S-4 provide
for more reliable long term protection through additional
reduction in toxicity by permanently destroying some of the
contaminants through treatment. Alternatives S-5 and S-6 involve
the greatest treatment components and would be more effective in
the long term because they would permanently destroy site
contaminants. However, the high cost to implement the off-site
incineration alternative (S-6) and increased length of time to
implement the on-site thermal desorption alternative (S-5) make
these options problematic.
For Alternative U-l (no action with respect to underground
utilities, equipment, and curbs and foundations), the quantity of
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site-related compounds in underground structures is expected to
remain constant for the foreseeable future. For Alternatives U-2
(plugging and cleaning underground utilities, equipment, and
curbs and foundations),and U-3 (plugging, cleaning, and sealing
underground utilities, equipment, and curbs and foundations) the
residual contaminant concentrations remaining after remediation
would be minimal. Alternative U-3 would provide an additional
level of effectiveness by the grouting up of the sewer line,
which would reduce the potential for collapse and transmission of
groundwater, and the sealing of foundations and curbs would
prevent contact with contaminants that cannot be removed by
scarification.
4. Reduction of Toxicity, Mobility, or Volume of the
Contaminants through Treatment
A significant reduction in toxicity, mobility and volume of
TCDD is not expected under Alternative S-l (no action), since any
reduction under the no action alternative would occur through
natural attenuation mechanisms. Alternatives S-2, S-7 and S-8
rely on capping and/or excavation and landfilling. Therefore,
this criterion is not applicable because neither involves
treatment. Alternative S-8 provides the greatest reduction of
the mobility of the three alternatives due to extensive soil
isolation, yet does not involve treatment. Alternatives S-3 (on-
site desorption and chemical treatment) and S-4 (on-site
containment, consolidation, and on-site incineration), which
incorporate capping, landfilling, and treatment options, address
reducing the toxicity, mobility and volume of TCDD at the site to
some extent. Alternatives S-5 (on-site desorption), and S-6
(off-site incineration) address soils with TCDD concentrations
greater than 50 ppb or 20 ppb depending upon the option
considered, would provide for the greatest reduction in toxicity,
mobility and volume of TCDD of all che options revi_.ed.
However, drawbacks to these options include the estimated 4 years
of on-site treatment time required under Alternative S-5 and the
extremely high cost of implementation associated with Alternative
S-6.
Alternative U-l would not provide for the reduction of
toxicity, mobility and volume of contaminants associated with the
on-site structures. Under Alternatives U-2 and U-3, contaminants
are removed from these structures, thereby significantly reducing
their toxicity, mobility and volume.
5. Short-Tent Effectiveness
All action alternatives require between 2 and 5 years to
implement. Remedial actions involving capping and excavation and
landfilling are generally faster to implement than those options
requiring combinations of on-site/off-site treatment, capping,
and landfilling.
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Alternative S-l (no action) poses no short term impact to
the community and site workers. Alternatives S-2 through S-8
pose some potential short term impacts to the community and
workers from dust generated during material handling activities.
Alternatives S-3 through S-6 pose additional impacts associated
with the operation of treatment systems. Short term impacts
posed by Alternatives S-5 and S-6 are greater than for the other
alternatives due to the relatively large volume of soil to be
excavated and treated, which COMM create a longer period of time
for potential exposure. Alternative S-5 involves transportation
of relatively small amounts of high concentration liquids off-
site, and poses the additional risks associated with excavation
and treatment of a large volume 01 contaminated soil, both of
which actions could create a longer period of time for potential
exposure. However, with respect to all alternatives that involve
excavation and material handling that generate dust, appropriate
engineering controls would be used for dust suppression, along
with other measures necessary to detect and prevent airborne
releases
No short term impact would result from implementation of
Alternative U-l (no action). Short term impacts associated with
Alternatives U-2 and U-3 are primarily from dust generated during
remedial activities. Appropriate engineering controls will be
used for dust suppression, along with other measures necessary to
detect and prevent airborne releases.
6. implementability
Alternative S-l is the easiest to implement because it
requires no further action. Alternatives S-2, S-7, and S-8
(capping and landfilling options) are relatively simple to
implement because they use conventional construction techniques.
Alternatives S-3, and S-4 are more difficult because they require
temporary soil storage and on-site treatment of soils. The
requirements for implementing Alternative S-6 are similar to S-3
and S-4 except that the volume of soils requiring excavation and
treatment is substantially larger. Alternative S-5 is the most
difficult to implement because it involves the same amount of
soil involved in S-6, except that both on-site and off-site
treatment options would be in effect.
Alternative U-l can easily be implemented as it does not
require any further action. Alternatives U-2 and U-3 can be
implemented using standard and specialized equipment.
Technologies and technical expertise associated with the
alternatives are readily available.
7. Coat
The costs associated with the alternatives described ranged
from $5,896,000 (Alternative S-2) to $164,601,000 (Alternative
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S-6). Annual operation and maintenance costs ranged from $10,400
(Alternatives S-5 and S-6) to $37,700 (S-2 to S-4).
The cost to implement Alternatives U-2 and U-3 are
$1,229,000 and $1,359,000, respectively.
8. State Acceptance
Under the Superfund law, EPA is required to ensure that
states have a meaningful and continuing role in remedy selection
and execution. While states are not required to concur formally
with EPA-selected remedies, if the remediation is funded by the
Superfund, the state where the site is located must contribute 10
percent of the remedy's construction cost. States are required
to formally concur with the deletion of a site from the National
Priorities List (NPL) upon completion of the remediation process.
For these reasons, EPA has kept ADPC&E staff informed regarding
the remedy selection process and has briefed the State on several
occasions concerning the remedial alternatives considered in the
FS and the preferred option set out in the original and
Supplemental Proposed Plan *->r OU2 and this ROD.
The ADPC&E has reviewed the FS, the May 1995 Proposed Plan
and the March 1996 Supplemental Proposed Plan, and has provided
EPA with comments on this ROD. The ADPC&E is in full agreement
with this ROD.
9. Community Acceptance
EPA recognizes that the community in which a Superfund site
is located is the principal beneficiary of all remedial actions
undertaken. EPA also recognizes that it is its responsibility to
inform interested citizens of the nature of Superfund
environmental problems and solutions, and to learn from the
community what its desires are regarding those sites.
EPA has undertaken an extensive effort to solicit input from
the community on the various remedial options considered for this
operable unit. The concerns the community raised at various
times during discussions with EPA include the following:
1) The on-site landfill should be located at the greatest
distance away from the nearest residences, its size should be
minimized, and its height should not exceed 25 feet; 2) For the
restricted access portion of the site (the area that would remain
fenced) workers should not have to wear "moonsuits" (the highest
level of protective clothing) to conduct their daily activities;
3) An attempt should be made to return a substantial portion of
the site to commercial/industrial productivity; 4) The cleanup
level for dioxin within the fenced area should be no greater than
5 ppb; 5) For the area outside the fence, the dioxin cleanup
level should be a maximum of 1 ppb; and, 6) That the smallest
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area possible be fenced to provide the maximum acreage for
potential future commercial/industrial redevelopment.
EPA, in the remedy selected in this document, has made an
effort to address these community objectives within Statutory
guidelines. While the community desired that the strip of
property along Marshall Road be cleaned to 1 ppb dioxin to
promote what they believed was a more attractive draw for
prospective land developers, they understand that the 5 ppb
cleanup level is justified by the risk assessment and defensible,
and that a lower cleanup level, like 1 ppb, for example, is not.
As such, the community understands that EPA cannot mandate a
lower cleanup level than is justified. However, through
discussions and meetings regarding the communities desire for 1
ppb along Marshall Road, Hercules, Inc., has indicated it would
evaluate this additional cleanup. Such action on the part of
Hercules, Inc., would be fully supported by EPA and totally
voluntary.
9.0 THE SELECTED REMEDY
Based upon consideration of the requirements of CERCLA, the
detailed analysis of the alternatives using the nine evaluation
criteria, consultation with the Arkansas Department of Pollution
Control and Ecology, and public comments, EPA has determined that
Alternatives S-2 (with the modifications described below for on-
site surface soils) and U-3, are the most appropriate remedies
for the Vertac Operable Unit 2 media. Given the reasonably
anticipated future land use for the site and the low level
threats at the site that this ROD addresses, and consistent with
the NCP's preference for EPA to implement containment remedies
when addressing low level threat wastes where treatment of those
wastes is impracticable (see NCP Section 300.'~0(a)(iii)(B), 40
CFR S 300.430(a)(iii)(B)), on-site consolidation of OU2 media,
including those similar media from the 1990 Off-Site Areas ROD
and the bagged soils Hercules, Inc., had excavated in a 1990
removal action from contiguous residential areas, is fully
protective and appropriate.
A component of the selected remedy uses excavation and
landfilling to address low level threats posed by contaminated
soil media. In addition, as discussed earlier, the remedy
selected also addresses contaminated soil originally intended to
be incinerated on-site. These materials consist of soils to be
removed from the Rocky Branch Creek flood plain, sludges removed
from the on-site sewage treatment plant and sediments from the
interceptor line as part of the 1990 Off-Site Areas ROD, and
residential bagged soil from the 1990 Hercules-performed removal
action whose disposition the 1993 OU1 ROD expressly deferred
until EPA executed the OU2 ROD. Because the on-site incinerator
is no longer operational and because those contaminated soils and
debris described above came from a contiguous area of
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contamination and constitute low level threat media, and
therefore in no way differ from the contaminated soil and debris
addressed in this ROD, EPA has determined that it is appropriate
to amend the 1990 Off-Site Areas ROD to reflect this change.
After remediation, the northern portion of the site will
have unrestricted access for commercial/industrial development.
EPA cannot determine the permanent fence locations on the
southern portion along Marshall Road until the remedial
design/remedial action phases begin. However, fence locations on
this portion of the property may be phased in order to provide
unrestricted access in the future for commercial/industrial
development. Figure 13 depicts the appr,..imate areas of the site
that will remain fenced in relation to the portion of the site
that will have unrestricted commercial access. It should be
emphasized that tne area shown on this drawing is approximate,
and the fencing will be conducted in phases, since a continuous
effort will be made to provide the maximum amount of property for
commercial redevelopment.
EPA acknowledges that contaminated sediments in Rocky Branch
Creek have resulted in ecological impacts. However, until the
site is remediated and the source of dioxin contamination
eliminated, the potential for continuing impacts exists through
contaminated surface soils, sediment transport and groundwater
seeps. With this remedy, the primary source will be removed
through consolidation of dioxin contaminated soils in the on-site
landfill and sediment transport resulting from the sump overflows
and storm water run-on and run-off will be reduced or eliminated
through storm water management, thereby eliminating ecological
risk.
Groundwater seeps from the contaminated areas of the site
into Rocky Branch Creek are currently impeded by th^ French drain
system installed along the western edge of the site and bordering
the on-site burial grounds, thereby preventing another potential
source of contamination for Rocky Branch Creek. Stream data
indicates no measurable dioxin concentrations, for example,
following rain events. Since Rocky Branch Creek is not a
perennial waterbody and does not flow through the site, the
removal of the contaminated soils and elimination of untreated
discharges and possible groundwater seeps will essentially
eliminate future impacts. While data suggests that existing
impacts in Rocky Branch Creek are on the decline, any actions to
remove contaminated sediments in Rocky Branch Creek would be cost
prohibitive, but more importantly, any disturbance of the
existing sediment could prove catastrophic, possible even
destroying the entire existing ecosystem. As such, this remedy
in addition to the other on-going remedies at the site will
effectively remove the contamination source and the storm water
transport concern allowing Rocky Branch Creek to continue, in
essence, a natural attenuation process.
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A summary of the selected remedy is presented below.
9.1 SOILS AND SEDIMENT MEDIA
1) On-sita Surface Soils
The selected remedy for the Vertac on-site soils media is
Alternative S-2, with the following modifications.
All soils on both the northern and southern parcels with dioxin
concentrations at or above the action level of 5 ppb will be
excavated and disposed of in the on-site landfill. While EPA did
not include this 5 ppb cleanup level in the description of
Alternative S-2 in the OU2 FS, EPA has received substantial
public comment regarding the use of a 5 ppb dioxin cleanup level.
In addition, EPA has reevaluated its risk assessment taking into
account the reasonably anticipated future land use for the site
and considering the low level threat media addressed by this ROD
for OU2. Therefore, EPA now selects 5 ppb as the appropriate and
fully protective action level for the implementation of
Alternative S-2.
The OU2 on-site soils area includes the area around the
existing Regina Paint Building, which is targeted for demolition
under the OU1 ROD. Sampling results indicate that some
excavation will be necessary in the areas around the Regina Paint
Building. Following remediation, the entire northern parcel will
be available for redevelopment.
All excavated site areas will be backfilled with clean soil,
compacted and revegetated. Some surface drainage modifications
may be used to control runon and runoff, thereby minimizing the
potential for erosion, and to facilitate positive drainage to
eliminate the possibility for ponding water.
During remedial action for this remedy, there is a
possibility of dust being created which could suspend dioxin
contamination. As part of the remedial action, continuous air
monitoring will be conducted and dust suppression measures will
be implemented to ensure that no airborne contaminants migrate
off-site to a receptor point. Therefore, no-site related
contaminants will be allowed to pose a threat to nearby citizens
or a casual passerby.
EPA will work with the Vertac Receiver and City of
Jacksonville to impose deed restrictions and notifications, or to
enact specific land use restrictions to limit the future use of
the property as appropriate for the long term remediation
efforts. Finally, upon completion of the remedy for OU2, long
term operations and maintenance measures will be instituted to
ensure, in part, that the integrity of the RCRA Subtitle C
hazardous waste landfill will be maintained.
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Another element of this portion of the remedy is a "phased
fencing" approach for the southern parcel. Once initial
remediation is complete, the smallest possible area of the site
will be fenced. A continuous effort will be made to provide the
maximum amount of property possible for potential commercial
redevelopment, as long term remediation efforts allow the
restricted area to be reduced.
2) Crystalline Tetrachlorobenzene (TCB) and soils associated
with the TCB spill
This component of the remedy -sails for the excavation and
off-site incineration of the crystalline TCB and TCB-associated
spill soils where the TCB concentrations exceed a 500 ppm health-
based action level. Excavated areas will be backfilled with
clean fill, graded and revegetated to prevent future contact with
the remaining soils that fell below the 500 ppm TCB action level.
It has been estimated in the RI that there are approximately
1,400 cubic yards (2,100 tons) of crystalline TCB and associated
soils for costing purposes. The actual volume of material will
be determined during the remedial action.
3) Bagged Soils from Residential Areas Excavated by Hercules,
Inc., During a 1990 Removal Action
This component of the remedy calls for the consolidation of
approximately 2,770 cubic yards (4,155 tons) of dioxin-
contaminated soils removed from residential yards in 1990 into
the on-site RCRA-compliant CCU. As discussed earlier, the
Agency's 1993 ROD had deferred treating these contaminated low
level threat soils and debris until all site soils were to be
addressed. Due to the similarity of the on-site soils addressed
ir. this ROD and the bagged soils from residen* 1 areas, EPA has
determined that it is appropriate to treut all low level threat
media in a manner consistent with the approach selected for the
on-site soils in this ROD, that is, on-site disposal in the RCRA
Subtitle C Landfill. Dioxin concentrations in the bagged soils
range between 13 ppb and 55 ppb TCDD, which is consistent with
the dioxin concentrations found in the soil and debris
principally addressed in this ROD.
4) Off-site Soils from the Residential Portions of Bayou Meto
and Rocky rranch Creek riood Plain Areas from the 1990 Off-
Site Areas ROD
This component of the remedy calls for the excavation of 1
ppb or greater (approximately 4,100 cubic yards or 6,150 tons)
dioxin-contaminated soils from along Rocky Branch Creek and Bayou
Meto and consolidation of this material into the on-site RCRA
compliant CCU that is being constructed as part of the remedial
action phase of the 1993 OU1 ROD. As discussed earlier, these
contaminated soils and debris constitute low level threat media
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and had originally been addressed in the 1990 ROD for Vertac Off-
Site Areas, which had required that they be incinerated in the
now-defunct on-site incinerator. Due to the similarity to the
on-site soils addressed in this ROD, EPA has determined that it
is appropriate to treat all low level threat media in a manner
consistent with the approach selected for the on-site soils in
this ROD, that is, on-site disposal in the RCRA Subtitle C
Landfill.
5) DevatereŁ Sludges from the Old Savage Treatment Plant Sludge
Digester and Sediments from the Interceptor line from the
1990 off-site Areas ROD
This component of the remedy calls for the consolidation of
approximately 890 cubic yards (1,200 tons) of digester sludge
from the Old Sewage Treatment Plant into the on-site RCRA
compliant CCU. Also, about 2 cubic yards of contaminated
sediment from the interceptor lines will be disposed in the CCU.
The dioxin concentrations found in the sewage treatment plant
digester are consistent with those being landfilled from on-site
areas. As discussed earlier, these contaminated soils and debris
had originally been addressed in the 1990 ROD for Vertac Off-Site
Areas, which had proposed that they be incinerated in the now-
defunct on-site incinerator. Due to the similarity to the on-
site soils addressed in this ROD, EPA has determined that it is
appropriate to treat all low level threat media in a manner
consistent with the approach selected for the on-site soils in
this ROD, that is, on-site disposal in the RCRA Subtitle C
Landfill.
The cost to implement Alternative S-2, with above-mentioned
changes in action levels, is estimated to be $12.25 million.
9.2 UNDERGROUND UTILITIES, FOUNDATIONS AND CURBS
The selected remedy for addressing the contaminants
associated with these structures at the site is Alternative U-3.
In addition to the elements already described in Alternative U-3,
the underground chemical sewer lines will be cleaned to remove
solids and filled with grout. Cut-off barriers will be installed
around various underground utility lines to prevent shallow water
migration along these lines. Foundations and curbs will be
cleaned through surface scarification, and for areas where
persistent staining exists, surface sealing will also be
employed. Further, the foundations and curbs will be covered
with adequate soil (typically between 18 and 24 inches) to
support a vegetative cover and contoured to prevent erosion and
prevent ponding of storm water. (The USTs were targeted to be
addressed in this component of the selected remedy, but as
previously discussed in Section 5.4.6 of this ROD, Hercules,
Inc., has recently pumped dry and backfilled these tanks with
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grout. Therefore, the five USTs no longer require remedial
action.)
The cost to implement Alternative U-3 for the underground
utilities lines, building and equipment foundations, and curbs is
estimated at $1.56 million.
The total estimated cost to implement both components of the
selected remedy is $13.81 million, The annual operation and
maintenance costs are estimated at $37,700. A more detailed
estimate of the annual operation and maintenance cost will be
provided in the site opertaion and maintenance plan to be
developed during the remedial design.
10.0 STATUTORY DETERMINATIONS
Section 121(b)(1) of CERCLA, 42 U.S.C. $ 9621(b)(l),
requires that EPA select remedial actions that are protective of
human health and the environment, that are cost effective, and
that utilize permanent solutions and alternative treatment
technologies or resource recovery technologies to the maximum
extent practicable. In addition, CERCLA Section 121(d)(l), 42
U.S.C. S 9621(d)(l), requires EPA to select remedies that comply
with applicable or relevant and appropriate environmental
standards (ARAR's) established under Federal and State
environmental laws, unless a waiver is granted. The following
sections discuss how the selected remedy meets the statutory
requirements.
10.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
The selected remedy is protective of human health and the
environment. The remedial action objectives and goals specified
in section 6.5 of this ROD will be met.
The selected containment remedy for the low level threat
site soils, sediments and sludges, underground utility lines, and
foundations is protective of human health and the environment
because:
1) All soils contaminated with dioxin concentrations of 5 ppb
and greater will be excavated and consolidated within an on-site
RCRA Subtitle C hazardous waste landfill. Excavation and
consolidation of» that low level threat material into the RCRA
landfill will substantially reduce the mobility of the site
contaminants and will prevent direct exposure through dermal
contact, inhalation, or ingestion by future site workers
maintaining the restricted access area and individuals passing by
the site. Excavation and consolidation of the contaminated soil
will also prevent the threat of leaching to ground water due to
the engineering of the landfill, and will reduce potential
sediment transport from runon and runoff. Such on-site
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consolidation of low level threat media is consistent with the
NCP's preference for containment remedies for low level threat
media where treatment is impracticable. See NCP Section
300.430(a)(iii)(B), 40 CFR S 300.430(a)(iii)(B).
2) Concentrations of dioxin-contaminated soil that will remain
in place will be below 5 ppb, and are estimated to be on average
less than 1 ppb, which is well below the concentration required
to be protective of human health and the environment. EPA data
indicate that such an average dioxin concentration will result
due to the excavation of grids containing dioxin concentrations
above 5 ppb and due to the fact that there already exist grids
v.hat contain dioxin concentrations below 1 ppb. Commercial
access will be possible for much of the site so as to allow
redevelopment of the maximum amount of acreage.
3) Crystalline TCB and TCB-contaminated soils above the 500 ppm
health-based limit will be excavated and transported off-site for
incineration. By permanently treating these wastes at an off-
site facility, the possibility of direct contact exposure is
completely eliminated. In ddition, the replacement of clean
topsoil will eliminate the contact exposure pathway for the TCB-
contamination below the 500 ppm action level.
4) Soils excavated from the contiguous areas of Rocky Branch
Creek, bagged soils from the contiguous residential areas, and
sediments and sludges from the old on-site sewage treatment plant
will be consolidated within the on-site RCRA Subtitle C landfill.
Excavation and consolidation of these sediments within a RCRA
Subtitle C hazardous waste landfill will substantially reduce the
mobility of these contaminants and will prevent direct exposure
through dermal contact, inhalation, or ingestion by members of
the public, who will be excluded from the landfill.
5) Underground utility lines will be closed and/or grouted to
prevent the possibility of ground water contaminant migration and
leaching through those lines. As discussed earlier, the USTs
have already been addressed, which has eliminated tne possibility
of future leaching of any petroleum contaminants.
6) Building foundations and curbed areas will be cleaned using
hydroblasting, scarification, epoxy sealing, and covered with
adequate soil to provide vegetative cover and contoured to
prevent erosion and ponding water. After such remediation, these
structures will not present an exposure hazard Ło future workers.
Short-term risks associated with the selected remedy can be
controlled by closely monitoring the design and implementation of
remedial measures and employing continuous air monitoring and
dust suppression measures during construction phases. No adverse
cross-media impacts are expected from implementation of the
selected remedy.
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10.2 COMPLIANCE WITH ARAR'S
The selected remedy for site soils, sediments and sludges,
underground utility lines, and foundations, will comply with all
ARAR's identified for the site. The ARAR's applicable to the
selected remedy are presented below:
Due to the fact that the excavation of the contaminated
soils and debris proposed in this ROD and their subsequent
consolidation within the CCU will occur entirely within the area
of contamination, and because no treatment will occur that would
result in those materials' placement under LDRs within the CCU,
RCRA's land disposal restrictions do not appj.y. In addition,
those restrictions do not apply to the soil and debris from the
1990 Off-Site Areas ROD or to the bagged residential soils
Hercules had excavated from contiguous areas as part of a 1990
removal action, because they were also removed from within the
area of contamination (AOC) and have not been treated. The
substantive (versus procedural) RCRA minimum technology
requirements (MTR's) for hazardous waste landfills are applicable
to the CCU, due to the fact that all soil and debris
consolidation actions will occur entirely within AOC. See 40 CFR
SS 264.301(a, c, g-j), 264.302(a), 264.310(a) and (b) 264.312,
264.313, 264.314, 264.315, 264.316, 264.317. Therefore, design,
construction, and operation of the CCU will substantively comply
with MTR's. Finally, no ARAR exists for the backfill of clean
soil over areas with dioxin contamination.
Crystalline TCB and spill-related soils will be excavated
and taken off-site for treatment, and therefore ARAR's do not
apply to the off-site component of this action. However, RCRA
manifesting and pre-transportation requirements are applicable to
tha elements of this action that occur on-sit*- Those RCRA
requirements concerning manifesting, waste packaging, labeling,
waste analysis and notification to treatment, storage and
disposal facilities subject to land disposal restrictions are
found at 40 CFR SS 262.20 - 262.23 and 262.30 - 262.32, and 40
CFR 268.7, and apply in their entirety to off-site shipments of
hazardous wastes.
In addition, while not constituting an ARAR, compliance with
the CERCLA Off-Site Rule, promulgated pursuant to CERCLA Section
121(d)(3), 42 U.S.C. S 9621(d)(3), and formally entitled
"Amendment to the National Oil and Hazardous Substances Pollution
Contingency Plan; Procedures for Planning and Implementing Off-
Site Response Action: Final Rule," 58 FR 49200 (September 22,
1993), and codified at 40 CFR 300.440, is mandatory for off-site
disposal actions.
The RCRA classification and listing as a K085 waste is
applicable, based on the TCB material's exhibiting the
characteristic of toxicity pursuant to analysis under 40 CFR S
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261.32. The land disposal restrictions require that K085-listed
wastes be treated to concentrations of constituents specified in
40 CFR S 268.43, which applies treatment standards set out at 40
CFR S 268.40, prior to land disposal. Such treatment will occur
at the off-site disposal facility. Transportation of crystalline
TCB and spill-related soils for off-site treatment/disposal would
need to comply with all the requirements set forth under 40 CFR
SS 107,171-177, and 263, the Hazardous Materials Transportation
Act, 49 U.S.C. S 1801 et seq.. and state hazardous waste
transportation requlations.
The Clean Air Act's (CAA's) National Ambient Air Quality
Standards (NAAQS), 40 CFR S 50.06, as administered through
Arkansas' State Implementation Plan (SIP), may not be applicable
to this component of the remedy since these standards are
applicable only to "major sources" or sources that emit over 10
to 25 tons per year of a regulated pollutant. The standards,
however, are relevant and appropriate because respirable dust
will be generated during the cleanup. In addition, the Arkansas
ambient air quality standards as described in the Non-criteria
Pollution Control Strategy are applicable.
Aqueous waste generated during the remediation activities
and during perpetual operation and maintenance, such as
decontamination water or leachate from the CCU, will be processed
through the on-site water treatment system. Water from this
treatment system will be discharged to Rocky Branch Creek,
monitored for compliance with State water quality criteria, and
self-reported in accordance with State-developed effluent
discharge limitations.
Erosion and sediment controls during excavation,
backfilling, regrading, and revegetation would have to comply
with local regulations.
10.3 COST EFFECTIVENESS
The selected remedy for Operable Unit 2 media is cost
effective and is fully protective of human health and the
environment based on reasonably anticipated future land use for
the site and the community objective of commercially redeveloping
the greatest amount of the site's acreage. Section 300.430
(f)(ii)(D) of the NCP, 40 CFR § 300.430(f)(ii)(D), 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, and short term effectiveness.
Overall effectiveness is then compared to cost to ensure that the
remedy is cost effective. For the reasons described in greater
detail in discussions above, the selected remedy meets these
criteria.
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The total estimated present worth of the selected remedy for
soils, sediments and sludges for the northern and southern
parcels, including underground utilities and foundations, is
$13,810,000. The variation in remedy costs evaluated for these
media ranged from $5,896,000 for Alternative S-2, with higher
site action levels to $164,601,000 for a total incineration
remedy. Even though the selected remedy does not provide for a
reduction in the toxicity or volume of dioxin in site soils,
landfilling will substantially .-duce the mobility of the
contaminants of concern. As stated earlier, the NCP favors
containment remedies for low level threat media, or where
treatment is impracticable. NCP Section 300.430(a)(iii)(B), 40
CFR S 300.430(a)(iii)(B). Due to the extreme cost of the
treatment remedies, EPA has concluded that such treatment is
impracticable. However, previously implemented remedies
associated with other operable units have accomplished a
reduction in toxicity and volume of dioxin as a site contaminant
where those dioxin-contaminated media were considered to
constitute a principal threat. As discussed earlier, however,
containment is deemed to be the preferred method of addressing
low level threat media, and the remedy selected in this ROD cost
effectively accomplishes that by utilizing the on-site RCRA
Subtitle C hazardous waste landfill being constructed as part of
the remedy for OU1.
10.4 UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE
TREATMENT TECHNOLOGIES TO THE MAXIMUM EXTENT PRACTICABLE
EPA has determined that the selected remedy represents the
maximum extent to which permanent solutions and treatment
technologies can be utilized in a cost-effective manner for this
operable unit.
Of those alternatives that were protective of human health
and the environment, and that comply with ARAR's, EPA has
determined that the selected remedy provides the best balance in
terms of long-term effectiveness and permanence, reduction in
toxicity, mobility, or volume achieved through treatment, and
taking into consideration short-term effectiveness,
implementability, costs, and State and community concerns. The
selected remedy is consistent with the WCP's preference of
employing containment remedies when addressing low level threat
media. NCP Section 300.430(a)(iii)(B), 40 CFR S
300.430(a)(iii)(B).
10.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
Due to the fact EPA has determined that principal threats,
as defined at NCP Section 300.430(a)(iii)(A), 40 CFR S
300.430(a)(iii)(A), are not at issue in this operable unit, the
remedy selected for OU2 does not require treatment to be
implemented. Therefore, EPA has determined that containment by
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consolidating the low level threat media within an on-site RCRA
Subtitle C hazardous waste landfill will effectively and
protectively address those low level threat media. Therefore, it
is not necessary or appropriate for the OU2 remedy to meet the
general statutory preference for treatment as a principal
element. Thus, EPA has determined that neither on-site thermal
desorption, on-site incineration, or off-site incineration for
the low level threat media are appropriate. TCB-contaminated
soils, however, will be excavated and transported off-site for
treatment.
All soils that contain concentrations of dioxin equal to or
greater than 5 ppb will be excavated and placed into the on-site
landfill. By landfilling all grids having dioxin contamination
levels of 5 ppb or more, approximately 99 percent of all dioxin
in site soils and debris will be contained. Thus, completion of
the remedy selected in this ROD, in conjunction with other
operable unit remedies and related CERCLA response actions, will
either contain or immobilize over 99 percent of the dioxin found
in the Vertac soils and debris. The total amount of dioxin
present in site soils and "" ~bris covered under this operable
unit's remedy selected herein comprises only about 1 to 5 percent
of the amount of dioxin that was buried in on-site landfills
under the 1984 Court-ordered remedy.
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES
The Original Proposed Plan for Operable Unit 2 media at the
Vertac site was released to the public in May 1995. As a result
of the Superfund Administrative Reforms issued in October 1995, a
Supplemental Proposed Plan was issued in March 1996. The section
of the ROD that follows explains the differences from the
original proposal and the selected remedy contained in this
document.
The modifications that have been made to the Record of
Decision for Operable Unit 2 media are the result of two
fundamental changes: The preference for treatment of principal
threats has been met through other remedial actions undertaken or
to be undertaken at the site, while this ROD addresses low level
threat media for which the NCP prefers containment remedies, and
the future land use scenario for only about two thirds of the
southern portion of the site will involve long term restricted
access due to the on-site containment of hazardous wastes.
Otherwise, the reasonably anticipated future land use, which is
commercial/industrial, for much of the site will be attainable
under the selected remedy.
In the original May 1995 Proposed Plan, EPA had envisioned
that approximately 50 percent of the southern 93 acres of the
site would eventually be returned to commercial/industrial use.
However, after reevaluating the long term operation and
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maintenance requirements for that area of the site, which will
involve maintaining the caps on the existing site burial areas,
the new RCRA Subtitle C hazardous waste landfill, and operation
and maintenance of a ground water treatment system, EPA believes
that a more realistic estimate would be that only a portion of
the property along Marshall Road could be available for future
redevelopment opportunities on the southern portion of the site.
Because access to about two thirds of the southern property will
remain restricted, except for site maintenance workers, the
selected remedy provides a more cost effective remedy that is
fully protective of human health and the environment.
The selected remedy for the Operable Unit 2 media differs
significantly from EPA's original May 1995 Proposed Plan and the
March 1996 Supplemental Proposed Plan in several areas. Those
differences are:
1) Off-site incineration of dioxin-contaminated soil is no
longer a component of the selected remedy.
The original Proposed Plan called for the excavation and
off-site incineration of the 8 most highly-contaminated soil
grids at the site (approximately 2,000 tons).
EPA's original rationale for incinerating the 8 most highly-
contaminated grids (out of a total of 461) at the site was based
on EPA's preference for treatment of principal threats and for
permanent remedies, and those eight grids had initially been
regarded to constitute a principal threat. Approximately 72
percent of the TCDD in site soils would have been treated at an
off-site facility.
After reevaluating all remedial options f the site, EPA
has determined that the preference for treatment of principal
threats is not necessary due to the fact that this ROD addresses
low level threat media, not principal threats, when all of the
media addressed in the ROD are considered as a whole. S_ee
Section 10.5 of this ROD. One should note, however, that the
off-site incineration of the TCB-contaminated soil has remained
unchanged .
2) The volume of TCDD-contaminated material that was proposed
for consolidation into the on-site RCRA Subtitle C hazardous
waste landfill within the fenced portion of the site has
increased.
The original May 1995 Proposed Plan called for the
excavation and consolidation of approximately 104 grids, or
approximately 17,059 cubic yards, of TCDD-contaminated soil into
the on-site landfill. The March 1996 Supplemental Proposed Plan
called for the excavation and on-site landfilling of TCDD-
contaminated soils with TCDD concentrations of 50 ppb or greater.
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Under that proposal, approximately 4,259 cubic yards of
contaminated soil would have been consolidated within the CCU.
The selected remedy will require that 112 soil grids that have
TCDD concentrations at or above 5 ppb (approximately 18,319 cubic
yards) be excavated and consolidatsd within the on-site landfill.
This represents approximately 99 percent of all the dioxin
present within site soils.
3) TCDD-contaminated soils outside the fenced area will
excavated and landfilled on-site wherever the TCDD
concentration exceeds 5 ppb.
The May 1995 Proposed Plan did not make a distinction
between the cleanup level for either the northern or southern
portions of the site, and selected 5 ppm as the cleanup level for
TCDD. The March 1996 Supplemental Proposed Plan set a 1 ppb TCDD
cleanup level for the northern (unfenced) portion of the site,
and proposed to cap the southern (fenced) portion of the site
where TCDD levels ranged between 5 and 50 ppb. Areas having TCDD
soil concentration levels above 50 ppb were to be excavated and
consolidated within the CCU.
As discussed earlier in this ROD, data indicate that
following the excavation of TCDD-contaminated soils, the average
TCDD contamination levels will be less than 1 ppb. EPA data
indicate that such an average dioxin concentration will result
due to the excavation of grids containing dioxin concentrations
above 5 ppb and due to the fact that there already exist grids
that contain dioxin concentrations below 1 ppb. Therefore, by
excavating soils where TCDD concentrations exceed 5 ppb over the
entire site, the remedy selected results in the same overall
cleanup goal as had been proposed in the original May 1995
Proposed Plan.
All other elements of the original proposed plan remain
unchanged in the selected remedy.
The changes discussed above were fully evaluated as other
remedial options considered in the OU2 FS and the original and
supplemental proposed plan. EPA's selected remedy is a
modification of Alternative S-2, which addressed landfilling of
dioxin-contaminated media. The difference between the selected
remedy and alternative S-2 is that EPA is requiring a more
conservative dioxin action level to trigger excavation and
landfilling fi.e.. 5 ppb rather than 50 ppb). In addition, the
remedy selected in this ROD differs from EPA's preferred
alternative selected in the March 1996 Supplemental Proposed Plan
in that there no longer is a soils capping component to the
remedy. This is in response to comments received during the
public comment period. The remedy selected herein also allows
the landfill height to be maintained at less than 25 feet, which
likewise constitutes an accommodation to public preferences.
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ATTACHMENT A
FOREWORD
The comments received in iexpense to EPA's initial May 1995
Proposed Plan for OU2 are addressed in the following document
titled "Original Responsiveness Summary." EPA's initial proposal
for remediation of soils called for the off-site incineration of
dioxin contaminated hot spots and on-site landfilling of dioxin
contaminated soils that exceeded a site-specific
commercial/industrial exposure level. Under this scenario
approximately two-thirds of the site would have potentially been
available for future commercial reuse.
Following the release of the initial Proposed Plan in
May 1995, EPA issued a series of administrative reforms for the
Superfund Program. One purpose of the reforms was to control
remedy costs and to promote cost effectiveness, and the reforms
directed EPA to base site cleanup decisions on practical future
land usage and reasonable contaminant exposure scenarios. As a
result of those reform measures, Region 6 reconsidered and
revised its Proposed Plan.
At an open house on March 5, 1996, EPA presented a
Supplemental Proposed Plan for OU2 and the "Original
Responsiveness Summary." The Supplemental Proposed Plan for OU2
eliminated the off-site incineration component of the original
May 1995 Proposed Plan, included capping in-place soils having
dioxin contamination between 5 to 50 ppb, and proposed on-site
landfilling of soil contaminated with dioxin in excess of 50 ppb.
Under this scenario none of the southern portion of the site
would have been available for future development. The community
strongly objected to the Supplemental Proposed Plan.
As a result of revisions to the initial Proposed Plan, some
of the following responses take into account EPA's preferred
alternative at that time. Therefore, some of the responses will
indicate that capping dioxin contaminated soils in-place is
appropriate. These comments reflect the EPA thinking at that
time and are included as part of the administrative record.
Nonetheless, the remedy presented in this Record of Decision for
the soils media is excavation of 5 ppb and above dioxin
contaminated soils and on-site disposal in a RCRA Subtitle C
Landfill, not capping.
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ORIGINAL RESPONSIVENESS SUMMARY
This "Original Responsiveness Summary" has been prepared to
provide written responses to comments received at the public
meeting and during the public comment period for the Proposed
Plan of Action for Operable Unit 2 media at the Vertac Superfund
Site.
An informal open house was held in Jacksonville on May 25,
1995, to discuss EPA's proposed plan of action for remediating
the contaminated soils at the Vertac site. A public meeting was
held at the Jacksonville Civic Center on June 15, 1995 to further
discuss the EPA's cleanup proposal and to formally accept
comments on the plan. The transcript of this meeting is included
in the Administrative Record. The comment period ran from May
26, 1995 to August 11, 1995.
Written comments on the proposed plan were submitted by the
Arkansas Department of Pollution Control and Ecology (ADPC&E),
Hercules, Incorporated, State Senator Bill Gwatney, the Concerned
Citizens Coalition, the En Lronmental Compliance Coalition, the
Jacksonville Chamber of Commerce, the Jacksonville Commerce
Corporation, City of Jacksonville Office of Economic Development,
the Jacksonville Serotoma Club, the Jacksonville Lions Club, the
Arkansas Peace Center, Vietnam Veterans of America, the
Environmental Health Association of Arkansas, Jacksonville
Mothers and Children's Defense Fund, and numerous concerned
citizens. ADPC&E also submitted additional comments on the draft
ROD which can be found in Appendix C.
As will be explained in greater detail within the
Supplemental Proposed Plan, which modifies the Proposed Plan upon
which the comments below were submitted, since the May 26, 1995,
issuance to the public of the initial Proposed Plan for OU 2, the
EPA announced a series of administrative reforms to the Superfund
Program on October 3, 1995, to be effective immediately. The
October 3, 1995, administrative reforms that EPA followed in
reevaluating the preferred remedy it had proposed for OU 2 were
those intended to control remedy costs and to promote the cost-
effectiveness of remedies for Superfund sites, and that directed
EPA to base remedy decisions on practical future land usage and
exposure pathways scenarios for a given Superfund site. In
addition, EPA's reevaluation of the preferred remedy for OU 2 of
the Vertac Site has been thoroughly reviewed and approved by EPA
Headquarters Dioxin Review Board to ensure its consistency with
EPA's decisions concerning dioxin-contaminated soils at
industrial sites elsewhere in the county. Finally, EPA has
requested that the Agency for Toxic Substances Disease Registry
(ATSDR) with its revised approach for OU2, and ATSDR has informed
EPA that this approach is protective of the human health and the
environment.
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Due to EPA's revision of its initial Proposed Plan for OU 2,
the responses to some of the comments will take into account
EPA's revised approach for the remediation of OU 2.
Arkansas Department of Pollution Control and Ecology comments
1. Comment: For years an earthen central ditch had been the
pathway for transportation/migration of off-
specification materials. During 1984-1985 Vertac
lined the bottom of the central ditch with
concrete. In 1986 Vertac gunnited the slopes of
the ditch.
The survey measurements and the persistent seepage
of groundwater into the central ditch indicates
that the base of the central ditch is below the
adjacent ground water level. Thus, contaminated
soil/sludge beneath the lined concrete is a major
and continuous source of ground water
contamination.
Any remedial action which leaves the highly
contaminated soil/sludge beneath the lined
concrete at the central ditch does not provide
adequate protection of the environment. ADPC&E
recommends inclusion of the soil/sludge beneath
the central ditch as part of the soil remedy.
Response: EPA acknowledges that the central ditch at the
Vertac site was used an unlined disposal conduit
for many years. However, information presented
during the remedial investigat' ~i at the site
indicates that bedrock is very near the surface in
this location and as such very little soil is
thought to be present in that area. Contaminants
in this area would most likely be present in
fractures in the bedrock itself.
Under EPA's selected remedy for the Vertac site,
the southern 100 acres (i.e., the area that
contains the central ditch) will be fenced and
access will be restricted to future site workers.
Soils within the restricted area that have dioxin
concentrations greater than 5 ppb and less than 50
ppb will be covered with 1 foot of clean soil to
prevent direct exposure by site workers. Deed
notices and appropriate restrictions will also be
placed on this portion of the site to prevent
unauthorized excavation into the soil cap.
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Ground water contamination at the site is being
addressed by EPA in a separate Record of Decision.
Comment: Soils beneath some of the tank foundations are
heavily contaminated. ADPC&E does not believe
sealing foundations where persistent staining
exists is a proper method of treatment. The
contaminated soils beneath tank foundations,
especially foundations that consist of ped: '.^ls,
should be remediated.
Response: EPA agrees that soils below many of the old
process tank foundations may be heavily
contaminated. However, because EPA has determined
that the southern 100 acres of site has little
potential for commercial redevelopment, access to
this area will be restricted for the foresseable
future. As such, site workers will be performing
their daily activities (mainly ground water
monitoring and treatment and site maintenance
activities) under an authorized health and safety
plan that will ensure their protection. Because
building foundations, curbed areas, and other
paved surfaces will remain in place, there is
little potential for direct exposure to
contaminants below these structures. Surface
contamination on foundations will be removed
through scarification and hydroblasting, and any
areas that have persistent staining will be
sealed.
Comment: EPA has indicated its desire to remediate the
eastern half of the central process "^ea for
future commercial/industrial usage. However,
under EPA's preferred remedy the foundations would
be left intact. Beneath some of those foundations
there could exist highly contaminated soil. So,
if and when industrialization of this section of
the site becomes a reality, construction
activities could bring contaminated soil to the
surface. Even with a comprehensive deed
restriction, it would be difficult to monitor the
integrity of every foundation. Therefore, the
above concern should be addressed at this time.
Response: EPA now has determined that access for most of the
southern 100 acres of the site will remained
restricted. However, a 150 foot wide buffer zone
along Marshall Road will be cleaned to
commercial/industrial levels and as such could be
developed for commercial/industrial purposes.
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There are no building foundations within the
buffer zone along Marshall Road that will require
remediation. See Figure 13 in the ROD.
4. Comment: Since EPA's preferred remedy is not specifically
listed in the feasibility study (FS), please
explain the nature of remedial activities once
excavation of the contaminated soil is completed
(i.e.. backfill!;*^, grading, placement of topsoil,
vegetative cover, etc.).
Response: EPA's selected remedy for site soils is
Alternative S-2 in the FS with designated changes
in action levels. Soils with dioxin
concentrations exceeding the action level of 5
ppb, but less than 50 ppb will be capped in place.
Capping will involve covering the contaminated
surface soil with a 6 inch layer of compacted
soil, topped by a 6 inch layer of topsoil, and
revegetating the cap. Excavated areas would be
backfilled and compacted with clean soil,
including 6 inches of topsoil (to return areas to
pre-excavation grade), and revegetated. Some
surface drainage modifications may be used to
control runon and runoff, thereby minimizing the
potential for the deterioration of the soil cap.
Concerned Citizens Coalition Comments
The Concerned Citizens Coalition is the group of
Jacksonville citizens that has undertaken the responsibility of
administrating the Technical Assistance Grant (TAG) for the
Vertac, Jacksonville, and Rogers Road landfill Superfund sites.
As part of that responsibility, the group felt compelled to
carefully evaluate the FS and EPA's Proposed Plan of action for
the Vertac soil remediation, and as such, has developed several
specific recommendations to EPA's proposal, which they designate
as the "Jacksonville Plan." EPA received numerous letters in
support of the "Jacksonville Plan," some of those included
letters from such parties as the State Senator, the Jacksonville
Chamber of Commerce, and the Jacksonville Serotoma Club.
The Major elements of the "Jacksonville Plan" are as
follows:
5. Comment: The on-site landfill should be constructed on the
extreme northwest section of the site. The base
dimensions shall not exceed 500 feet by 500 feet,
and the vertical height shall not exceed 25 feet.
In order to maintain the proposed landfill
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dimensions, the following should be considered:
1) Ship wood debris from the demolition
activities, salt and ash, bagged soils from off-
site residential areas, and other off-site soils
to an off-site permitted facility for treatment
and disposal; 2) decontaminate and recycle all
steel from non-product piping and vessels
structural steel (I-beams), steel doors, sheet
metal, etc.; 3) place product piping and vessels
into the landfill, and; 4) place concrete,
asphalt, bricks, and cinder blocks into the
landfill (crush prior to placement to minimize
long axis to 18 inches).
Response: Based on the current estimated volume of material
to be placed into the on-site landfill, the
dimensions should be very close to those presented
by the Concerned Citizens Coalition. However, the
exact dimensions will be established when the
design is finalized over the next few months. The
ROD for Oper,." le Unit 1 (the old process plant)
called for recycling of non-contaminated or
lightly contaminated material when possible.
Recycling, however, is not desirable when more
waste is generated during decontamination
activities than is generated from efficient
disposal practices. Specific details on recycling
of materials will be developed during the remedial
design.
Compaction of demolition debris, concrete, metal,
wood, etc, will be an integral component of the
landfill construction. Void spaces within the
landfill will be minimized to ensure the integrity
of the structure.
Wood debris, bagged soils and other off-site soils
must be remediated as specified in EPA Records of
Decision for the site. These materials have been
designated to be placed into the on-site landfill.
At present, no decision has been made regarding
the disposal of the incinerator salt and ash. EPA
is concurrently issuing for comment an Engineering
Evaluation Cost Analysis (EE/CA) that outlines
EPA's disposal preference for these materials.
That preference involves the on-site in the RCRA
Subtitle C landfill of the incinerator ash, salts,
and pallets on which the drummed ash and salts had
been stored.
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8.
9,
Consent: The landfill leachate handling system should be
protective of ground water and surface water and
consist of a temporary holding tank coupled to a
pump station with a direct pipeline to the on-site
water treatment system.
Response: The final design for the on-site RCRA Subtitle C
landfill has not been completed at this time.
However, because most of the material that will be
placed into the on-site landfill will be
construction debris and soil, very little leachate
is expected to be generated or collected from the
disposal unit. Any leachate collected from the
landfill would be processed through the existing
on-site ground water treatment system.
Comment: Roads to the new landfill should be constructed of
concrete or asphalt to minimize dust and sediment
migration.
Response: EPA agrees that dust suppression will be an
important aspect of soils remediation at the site.
The specific engineering controls that will be
used during soils remediation will be developed
during the remedial design phase of the cleanup.
It is likely that hard surface roads will be used
to allow access to the landfill during varied
weather conditions.
Comment: A large drainage swale or french drain should be
placed inside the fenced site area to control
surface water runoff.
Response: Surface runoff from the southern portion of the
site is currently directed through the existing
sump/water treatment system at the site, i.e., the
"first flush," or surface water that passes over
the site (which is typically the most
contaminated) is collected in the on-site sump
system and is processed through the on-site carbon
treatment system prior to discharge. Additional
drainage controls will be implemented as part of
the OU2 ROD that will minimize surface water runon
and runoff from areas that have been capped.
Comment: Establish a 75 foot unobstructed buffer zone
outside the fenced portion of the site. Outside
the buffer zone establish a 75 foot wide
vegetative barrier that will serve to obscure the
site from the community.
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Response: The selected remedy will require that a 150 foot
buffer zone be established for the southern
portion of the site along Marshall Road. A visual
barrier will also be established so as to obscure
as effectively as possible the site from the
surrounding community to the east and south.
10. Comment
The site fence line for the southern portion of
the site should be approximately 225 fact ^.~~^ of
Rocky Branch Creek, extending in a north-
northeast direction to the juncture of the two
existing site fences running east-west.
Response: EPA now believes that the future landuse scenario
for the southern 100 acres of the site should
involve long-term restricted access, rather than
extensive potential future commercial/ industrial
redevelopment.
In the proposed plan, EPA had origionally
envisioned that approximately 50 percent of the
southern 100 acres of the site would eventually be
returned to commercial/ industrial use. However,
after re-evaluating the long-term operational and
maintenance requirements for this area of the site
(i.e. , maintaining the caps on the existing site
burial areas, the RCRA Subtitle-C landfill, and
operation and maintenance of the ground water
treatment system) , EPA believes that these
operations will substantially reduce the chance
for extensive future redevelopment opportunities
on the southern 100 acres. Thus, the site fence
along the eastern bo.rder of the site -'ill be
located approximately 150 feet west or Marshall
Road generally running in a north-south direction.
11. Coament:
Response:
All buildings and structures, including concrete
and asphalt pavements, within the existing
Hercules security area should be demolished and
disposed of properly.
The ROD for Operable Unit 1 requires that all
above ground structures at the southern portion of
the site, including buildings and plant equipment,
be demolished as a part of site remediation. In
addition, most of the above ground structures in
the northern portion of the site will also be
removed except for the old munitions bunkers,
which were never a part of herbicide operations at
the site, and possibly the EPA-constructed pole
barns. Some interest has been expressed that
8
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12. Comment:
these structures may be useful for future
commercial operations. EPA will ensure that these
structures were decontaminated and clean if left
in place.
Because access to the southern portion of the site
will remain restricted, building foundations,
curbed areas, and roads will remain in place after
cleaning.
Hercules should construct permanent office and
equipment storage facilities, not temporary
structures.
Response: Construction details involving office space, site
maintenance facilities, and the waste water
treatment plant will be addressed during the
remedial design phase of the cleanup. These
issues are generally not specified in a ROD.
13. Comment:
Hercules should clean all soils to an acceptable
action level of 5 ppb within the security
perimeter. All areas outside the security
perimeter shall be cleaned to 1 ppb 2,3,7,8-TCDD
toxic equivalent quotients (TEQs).
Response: Since the May 26, 1995, issuance to the public of
the initial Proposed Plan for OU 2, the EPA
announced a series of administrative reforms to
the Superfund Program on October 3, 1995, to be
effective immediately. The October 3, 1995,
administrative reforms that EPA followed in
reevaluating the preferred remedy it had proposed
for OU 2 were those intended to control remedy
costs and to promote the cost-effectiveness of
remedies for Superfund sites, and that directed
EPA to base remedy decisions on practical future
land usage and exposure pathways scenarios for a
given Superfund site. In addition, EPA's
reevaluation of the preferred remedy for OU 2 of
the Vertac Site has been thoroughly reviewed and
approved by EPA Headquarters Dioxin Review Board
co ensure its consistency with EPA's decisions
concerning dioxin-contaminated soils at industrial
sites elsewhere in the county. Finally, EPA has
requested that the Agency for Toxic Substances
Disease Registry (ATSDR) with its revised approach
for OU2, and ATSDR has informed EPA that this
approach is protective of the human health and the
environment.
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14. Comment:
Therefore, EPA has concluded that capping in place
soils with dioxin concentrations exceeding the
action level of 5 ppb, but less than 50 ppb, will
be protective of human health and the environment
and cost effective. Capping will involve covering
the contaminated surface soil with a 6 inch layer
of compacted soil, topped by a 6 inch layer of
topsoil, and revegetating the cap. Excavated
areas would be backfilled and compacted with clean
soil, including 6 inches of topsoil (to return
areas to pre-excavation grade), and revegetated.
Some surface drrinage modifications may be used to
control runon and runoff, thereby minimizing the
potential for the deterioration of the soil cap.
Soils with dioxin concentrations in excess of 50
ppb will be excavated and consolidated within the
on-site RCRA Subtitle C landfill.
All areas east of the Hercules security perimeter
shall be reclaimed to original grade with a slope
not to excei.~ 2 feet per 100 feet.
Response: Details involving the extent and location of
excavation, capping, and grading will be developed
during the remedial design phase of the cleanup.
15. Comment:
No contaminated soils shall be used as filler for
restoring excavated areas to grade.
Response: EPA agrees. Only clean soil will be used for
backfilling purposes.
Citizens' comments
The citizens of Jacksonville showed a decided interest in
EPAs proposal to remediate soils <*t tue Vertac site. Over 300
citizens responded either individually or by signing various
petitions stating their cleanup preferences for the site.
Similar questions have been grouped together in order to more
fully respond to all the issues raised by the Jacksonville
community.
16. Content:
Locate the landfill to the NW adjacent to or on
the other side of the present landfills.
Response: Over the past several months EPA has been working
with ADPC&E and Hercules to develop an alternate
location for the on-site RCRA Subtitle C landfill.
In order to be responsive to the community
interest on this issue, the proposed location for
the new landfill will be on the west side of Rocky
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17. Comment
Branch Creek, roughly at the midpoint from north
to south. EPA, however, is still working out a
potential conflict situation with the U.S. Air
Force that is currently planning on upgrading
their sanitary sewer line which crosses the Vertac
property near the proposed landfill location.
Currently, it appears that the two projects can
proceed as planned if closely coordinated.
Reduce the height of the landfill, transport the
maximum amount of waste from the site, and
landfill only what cannot be transported. The
maximum height of the landfill should not exceed
25 feet.
Response: There are two primary alternatives that can be
implemented in order to reduce the height of the
RCRA Subtitle C landfill that will be constructed
at the site: 1) Make the footprint of the
landfill larger, thereby lowering the height of
the structure, or; 2), put less material into the
landfill. Because of the overwhelming response by
the community to locate the landfill at the back
portion of the site, the ability to increase the
size of the landfill footprint is limited. So, to
minimize the height of the landfill, EPA agrees
that less material should be placed into the unit.
However, off-site transportation and treatment of
soils from the Vertac site is a cost prohibitive
operation. Estimates from the OU2 FS show the
cost to excavate site soils and transport them to
an off-site incineration facility to be
approximately $6,000 per ton. "f-site treatment
of dioxin-contaminated soils above the 50 ppb
action level would exceed $25,000,000. EPA will
now require that most of the contaminated soils at
the southern portion of the site to be capped in
place. Access in this area will be restricted to
on-site maintenance workers, and by capping all
dioxin-contaminated soils below 50 ppb, workers
will not be required to wear protective clothing
to conduct their daily site maintenance
activities. EPA will, however, require the most
contaminated areas of the site to be excavated and
landfilled. This is a change from landfilling
approximately 17,000 cubic yards to about 4,200
cubic yards. Capping is a cost effective means of
minimizing any potential threat to human health or
the environment, while reducing the size of the
on-site landfill. EPA normally does not include
actual specifications for remedial alternatives in
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18. Comment:
a ROD. Those issues will be addressed during
remedial design.
Restore the original buffer zone between the
residences and the plant site, move the fence and
gates to the original location, clean the soil on
the south and east side to 1 ppb.
Response: It will be impossible to move the fence
at the southern side of the site to its original
location, because of the existence of the French
drain leachate collection system which is a part
of the long term remediation effort of the site.
The French drain was installed in 1986, under a
court-ordered remedy, to intercept ground water
contamination that could potentially pass beyond
the site boundary. Pursuant to the 1986 Court-
orderd remedy, Hercules is required to maintain
the French drain system for a minimum of 20
additional years. Under this remedy EPA will
require trees to be planted along the perimeter of
the site where access will be restricted so as to
provide a visual buffer to residents that live
along the southern and eastern margins of the
site. In addition, EPA will require that the
southern gate be closed and new fencing be
installed that will prevent future access to site
from that area.
In response to the requested 1 ppb action level,
as discussed in Response Number 15, EPA has
established a 1 ppb action level for dioxin for
all areas of the Vertac site that will be outside
of the restricted access portion of w~a site.
This will include a strip along Marshall Road and
the northern 100 acres of the site which is slated
to be returned to a commercial/ industrial
development. The area of the site along the
southern fence is currently at or below the 1 ppb
action level for dioxins. All areas within the
restricted access southern portion of the site
will be cleaned to a 5 ppb dioxin action level.
19. CoBuumt:
The heart of the plant site should be cleaned so
that all grids with more than 5 ppb dioxin will be
excavated and cleaned.
R«spons«: See response to Comments 15, 18 and 19.
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2 0. Comment:
Place warning signs at inside perimeter of buffer
zone.
Response: Appropriate signage will be required as part of
this remedy. Areas of the site that will have
restricted access will be so designated.
2l. Comment:
Dress up green area and maintain in a well-groomed
condition.
Response: Hercules will be required to maintain all
restricted access portions of the site. This will
include such activities as landscaping and mowing
so as not to present a public nuisance.
The following nine comments are of a similar theme and are
listed separately but responded to as a whole.
22,
Comment:
23,
Comment:
24,
Comment:
25.
26,
27,
Comment:
Comment:
Comment:
28. Comment:
I want to see you give us a generous buffer zone
between the homes and the plant site. I would
ultimately like to see the whole thing taken away
and a park put on it,
Move it and move it all. This is a horrible
situation for Jacksonville and unsafe. This
should be EPA's job to see that this is all
cleaned up. Please don't leave us with this mess
and the problems that go with it.
I would like to express my hope that the Vertac
site be returned to its original use as an
industrial site. The end use of this property,
including along Marshall Road is of the utmost
importance to Jacksonville. I support an
effective, expeditious cleanup, such as
recommended by EPA.
I feel that the site should be cleaned up totally
so that it would be safe for children to be on the
grounds.
Return the site to the very best condition
possible.
Clean the northern portion of the site to
commercial standards or for use as a city park.
The southern portion of the site should be cleaned
to industrial standards.
All necessary action should be taken to ensure
that the Vertac site is cleaned up to the point
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29. Comment:
30. Comment
that the site can be used for commercial
development, city park, or residential
development.
We have lived under the stigma of Vertac for so
long that regardless of how long it takes, we want
the site cleaned up totally. This location should
be suitable for a park for children when cleanup
is completed.
We encourage the restoration of the site to its
original condition prior to development by
Hercules Chemical Company and its predecessors.
That would include: A) Removal of all structures;
B) removal of all buried wastes; C) removal of all
contaminated soils, and D) ; restoration of ground
water to background standards. We would like to
see in the future a site that could be used for
any activity including development and use as
parks, residences, commercial establishments or
industrial '"cilities.
Response: EPA agrees that cleanup of the Vertac site is
necessary. Under the proposed remedy for the
Vertac site soils, approximately 50 percent of the
property will be available for
commercial/ industrial redevelopment. This is due
to the facts that the southern portion of the site
currently contains landfills and will contain the
RCRA Subtitle C landfill, which will be
constructed to contain site equipment, debris and
soils. In addition, that portion of the site
contains ground water monitoring and treatment
facilities, whioh will renain in place due to the
necessity for conducting long term ground water
remediation and monitoring. Therefore, most of
the southern portion of the site will remain under
restricted access. However, a north-south strip
of land along Marshall Road (approximately 150
feet wide) will be cleaned so as to allow for
commercial development in that area.
As previously stated in response to Comment 11, a
buffer zone will be in place for the southern and
eastern portions of the site. These areas are or
will be cleaned up to 1 ppb for dioxin, and visual
vegetative barriers will be installed. Because of
the extensive contamination present at the old
process plant area of the site, cleanup to a level
that would permit the development of a park would
be cost- prohibitive. EPA, when developing
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appropriate remedies for a site, must also
consider the past use of that property. The
Vertac property has been in commercial use for
over 60 years, and as such, EPA's remedy for the
site must be consistent with its past use.
Finally, EPA's mandate under the Superfund law is
to provide long term solutions to hazardous
substance contamination problems by abating
conditions that pose imminent and substantial
endangerments to the human health and the
environment. However, under the Superfund law,
EPA is prohibited from substantially improving a
property beyond its pre-contamination condition.
Because the proposed remedy for OU 2 will be
protective of the human health and environment and
will allow a substantial portion of the site to
return to industrial usage, EPA will meet its
mandate while not improving the property beyond
its existing industrial usage, which would be the
case were it to accomplish a cleanup goal that
would permit residential uses of the property.
31. Comment: I believe it is in the best long term interest of
the EPA, the City of Jacksonville, and the State
of Arkansas to not bury any more wastes at the
site. There are sufficient off-site landfills
available able to receive these wastes.
Response: One of the issues that EPA had to consider when
evaluating disposal options for dioxin
contaminated soils at Vertac was the "dioxin rule"
which states that if dioxin wastes are taken off-
site then they must be treated 'a the Best
Demonstrated Available Technology (BOAT) prior to
disposal. BOAT requires that a treated F-02X
waste (dioxin-containing waste) be reduced to less
than 1 ppb TCDD as determined by the toxicity
characteristic leaching procedure (TCLP) found at
40 CFR Part 261, Appendix II, prior to land
disposal in a RCRA permitted landfill. Therefore,
any soil that is transported off-site would first
have to be incinerated (at a cost of approximately
$4,000 per ton) and then the residuals would have
to be land disposed in a RCRA Subtitle C landfill
per RCRA regulations. Thus, the cost for off-site
disposal of dioxin wastes is extremely high. On
the other hand, on-site disposal of dioxin-
contaminated soils may be land disposed in a RCRA
Subtitle C landfill without triggering the 1 ppb
land ban requirement if done within a contiguous
"area of contamination" (AOC). According to EPA
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guidance (OSWER Directive 9347.3 05FS), "for the
land disposal restrictions (LDRs) to be applicable
to a CERCLA response, the act must first
constitute placement of a restricted hazardous
waste." Therefore, it must first be determined
whether consolidation activities considered or
contemplated at the site constitute placement, and
if a RCRA hazardous waste is involved. To assist
in defining when placement does and does no*- ^ccur
for CERCLA actions involving on-site disposal of
wastes, EPA uses the concept of areas of
contamination (AOCs) which are equivalent to RCRA
units, for the purpose determining the
applicability of RCRA's land disposal restrictions
found at 40 CFR Part 268. An AOC is delineated by
the areal extent of contiguous contamination.
Placement does not occur when wastes are left in
place, or moved within an AOC. Specifically,
"placement does not occur when the wastes are
consolidated within the AOC." See preamble to the
National Contingency Plan (NCP), 55 Federal
Register 8759 - 8760, March 8, 1990.
In addition, minimum technology requirements are
also not required within the AOC but may be
relevant and appropriate requirements for such a
CERCLA action. If materials are treated on-site
within the AOC and then redeposited within the AOC
such as within a landfill, then placement has
occurred and land disposal restrictions would
apply. However, as noted above, because the
proposed on-site landfilling of dioxin-
contaminated soil and debris will occur entirely
within the Vertac AOC, but without p^or
treatment, placement will not occur for purposes
of applicability of the RCRA land disposal
restrictions.
32. Coament: it is in the best long term interest to exhume the
existing wastes. I realize there are existing
court decisions and RODs that must be overcome in
order for this to occur. I believe that it can be
done, and shorten the overall site cleanup,
including that for groundwater.
Response: In 1984 EPA challenged the court-ordered plan for
disposal of waste materials in the on-site burial
areas at Vertac with no success. See Order of the
U.S. District Court for the Eastern District of
Arkansas, Western Division, in U.S. v. Vertac
Chemical Corporation and Hercules. Inc.. No. LR-C-
16
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80-109, July 18, 1984. Because that Order is now
unappealable, EPA will continue to evaluate the
effectiveness of the Court-ordered remedy, and
will respond as appropriate.
33. Comment: I believe the dioxin cleanup standard should be
1-10 ppb. I do not object to the on-site
treatment via incineration or tilling of soil for
exposure to sunlight.
Response: EPA has established that 5 ppb dioxin cleanup
standard is appropriate for a
commercial/industrial future use exposure scenario
for the Vertac site. EPA no longer favors
additional treatment of dioxin-contaminated soils
at the Vertac site for the following reasons:
When looking at the Vertac site and each of the
six operable units as a whole, it can be seen that
a substantial amount of treatment, both on-site
and off-site, have been employed to address
principal threats at the site. Examples of on-
site treatment include the incineration of
approximately 29,000 drums (10,000 tons) of
dioxin-containing organic liquids. The dioxin
concentration in these drums was one to several
orders of magnitude greater than that generally
found in the Vertac site soils. In addition, the
contents of the abandoned tanks at the site, oily
leachate from the french drain system, and
contaminated carbon from ground water treatment
operation will also be treated by incineration at
an off-site facility and will exceed approximately
5,000 additional tons of material. As such, a
significant amount of the dioxin at the site has
or will be treated during site remediation
efforts.
34. Comment: I object to siting the landfill on clean soil near
the railroad. I believe that this area should be
kept clean for future development.
Response: EPA received overwhelming response from
Jacksonville citizens that if an above ground on-
site landfill was necessary at the Vertac site,
that it be placed as far back on the Vertac
property as possible and that its height be
restricted to 25 feet or less if possible. The
current proposed location for the on-site landfill
is responsive to those concerns. As far as future
development in the proposed landfill area, it is
true that this area is clean. However, because of
17
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35,
Comment:
the location of Rocky Branch Creek to the east and
the railroad to the west, access to this area is
extremely limited.
EPA's proposals do not take into account exposure
of children, who are at higher risk and when
factored in make risks unacceptable.
36,
37,
38.
Response: The future land use for the Vertac site was
assumed to be a commercial/industrial scenario,
and is based on the most probable use of the land
and current land u?e zoning requirements. For a
commercial/industrial type scenario exposure to
adults is evaluated rather than to children.
Comment: Alternative disposal methods should be employed,
not incineration, either off-site or on-site.
Response: In the proposed remedy for Vertac soils, off-site
incineration is no longer a component of the
cleanup. I--,tead, EPA has proposed employing on-
site landfilling and on-site capping as
alternative disposal methods.
Comment: Health monitoring, health surveys and a disease
and hazardous waste exposure registry should be a
priority for the Vertac site.
Response: A health and exposure study was initiated by the
Arkansas Department of Public Health (ADPH) in
conjunction with the Agency for Toxic Substances
Disease Registry (ATSDR) and the Centers for
Disease Control (CDC) over four years ago, and is
ongoing. Preliminary results of these studies
have been presented to the public during a number
of public meetings over the past several years.
The commenter is referred to the Arkansas
Department of Public Health for information
concerning the results from those studies.
Comment: Opening up any part of the site that does not have
less than 1 ppb TEQs is irresponsible and contrary
to EPA's mandate to safeguard health and safety.
Response: Under the proposed remedy for on-site soils, all
portions of the site that will be available for
commercial/industrial development will be
remediated to an action level of 1 ppb for dioxin.
Areas that will remain fenced where access will be
restricted to on-site workers will be remediated
to 5 ppb for dioxin.
18
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39. Comment:
Landfill ing is at best a temporary solution. The
existing landfills have breached the French drain
and there is some evidence that the ground water
at the site is contaminated.
Response: EPA currently has no data from Vertac ground water
monitoring program that would suggest that the
French drain leachate collection system is not
functioning as designed. EPA does, however,
acknowledge that the ground water under the Vertac
site is heavily contaminated with site compounds.
The results of the ground water investigation at
Vertac can be found in the OU2 Phase 1 and Phase 2
Remedial Investigation Reports. Ground water
remediation will be addressed as part of the
Record of Decision for Operable Unit 3. EPA
expects to release a Proposed Plan to discuss
potential ground water remediation options within
the next several months.
40. Comment:
Construction of a landfill will allow more
airborne particulates and fugitive emissions.
Response: The construction of the on-site landfill is
required as a part of the Record of Decision for
Operable Unit 1, where all building debris and
equipment from the demolition of the plant will be
disposed in the on-site landfill. Appropriate
dust suppression measures will be employed and
monitoring will be conducted to ensure the safety
of workers and residents living near the site. As
a part of the proposed remedy for Operable Unit 2
(Soils) , EPA is now requiring r,uch reduced
volume of soil to be placed into the on-site
landfill which should substantially reduce any
issues concerning fugitive emissions from soil
excavation operations.
41. Comment:
Establish a laboratory, testing and research
facility on the Vertac site for the future
evaluation of non-thermal dioxin destruction
technologies .
Response: Many lawsuits have been filed over the past
several years concerning the potential for
emissions from on-site remedial operations to
impact the local community. EPA is curious why
the commenter would be interested in EPA setting
up an experimental testing facility to work on
dioxins near a residential community. Little is
known about the potential emissions from many of
19
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the new and untested technologies. Such a testing
facility would most likely have to be in place for
many years to determine the effectiveness of new
treatment technologies. EPA does not favor such a
proposition for this site.
Arkansas Peace Center, Vietnam veterans of America,
Environmental Health Association of Arkansas/
Jacksonville Mothers and Children's Defense Fund,
and the Environmental Compliance Organisation
Comments
42. Comment:
43,
The failure to characterize all dioxin and furan
congeners, and to include analyses-supported toxic
equivalency quotients (TEQs) into the generation
of remedial goals (RGs) is seriously problematic,
as is the failure of the risk assessment to
provide calculations for all possible exposure
scenarios. Therefore, selection of remedial
alternatives should be deferred until adequate
analytical data in regard to dioxins and furans
are available.
Response: EPA agrees that it is important to evaluate all
dioxin and furan congeners when addressing the
risk from exposure to site soils. Because these
data were not available for most of the sampling
that was conducted for the site during the
remedial investigation, EPA is requiring that all
soil remediation be conducted with respect to
dioxin and furans as 2,3,7,8-TCDD toxicity
equivalents (TEQs). That is to say, for each soil
grid remediated at the site, the average
dioxin/furan concentration shall not =xceed the
action level as for TCDD and TCDFs as TEQs.
Comment: There is a concern regarding the absence in all
data obtained for review of an attempt to
calculate soil remedial goals that would be
protective of the extremely aggressive ground
water Maximum Contaminant Limit (MCLs) of 30 parts
per trillion (TEQ) for dioxin established by EPA
and the even lower TEQ thought to be protective of
surface water.
Response: Remediation of ground water at the Vertac site
will be addressed as part of the Operable Unit 3
ROD. In general, the ground water situation at
the Vertac site is extremely complex, due to the
presence of dense nonaqueous phase liquids
(DNAPLs) and questions as to how they move within
20
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44. Comment:
a tilted, fractured bedrock environment. These
dense phase liquids typically migrate down along
dipping rock strata and are trapped in fractures
where current remediation technologies have a very
limited potential of capturing them. As such,
these DNAPLs will provide a long term source for
dissolved phase contamination at the site. A
ground water technical impracticability waiver
will most likely ^e sought for the central process
plant portion of the site, and thus attainment of
MCLs will not be required. One positive point is
that ground watrr (even though highly
contaminated) does not move quickly under the
Vertac site. With over 40 years of on-site
operations, current data suggest that the ground
water plume has not migrated beyond the boundaries
of the site. Various forms of ground water
containment will be necessary, however, to ensure
that migration of site contaminants is controlled
over the long term.
There are concerns that the favored plan of action
to include off-site disposal and on-site
landfilling appears to be less than fully
protective of human health and the environment, as
required by the National Contingency Plan (NCP),
and does not provide mandated treatment to reduce
the toxicity, mobility, and/or volume of the
waste.
Response: EPA disagrees. Soils within the restricted access
portion of the site that are highly contaminated
will be excavated and consolidated into an on-site
RCRA Subtitle C landfill. Soils that contain
lower levels of contaminants will be capped in
place. Both excavation and consolidation into a
RCRA landfill, and capping in place, will
substantially reduce the mobility of site
contaminants and will prevent direct exposure
through dermal contact, inhalation or ingestion by
future site workers maintaining the restricted
access area. Therefore, the proposed remedy is
fully protective of human health and environment.
When evaluating the Vertac site and each of the
six operable units, it can be seen that a
substantial amount of treatment, both on-site and
off-site, have been employed to address principal
threats at the site (i.e., the most toxic and
mobile materials). Over 15,000 tons of dioxin-
containing organic liquids and sludges have been
21
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45. comment:
treated through both on-site and off-site
incineration.
We find no discussion of the RCRA land ban
restrictions on the type of waste contemplated for
land disposal in this instance as Applicable,
Relevant and Appropriate Requirements (ARARs).
Response: Page 44 of the Proposed Plan for OU2, and page 12
of the OU2 Fact Sheet both discuss compliance with
ARARs and specifically address land ban issues.
A complete discussion of potential ARARs for each
disposal option is presented in Sections 2.2, 2.3
and 2.4 of the OU2 feasibility study. Pages 2-12
through 2-16 deal with RCRA disposal and
specifically with TSD facility requirements, land
ban, and consolidation issues. See also response
to Comment 32.
4 e. Comment:
Response:
There is con rn that there has been limited
chemical and physical characterization of the
condition of the existing disposal areas on the
site. We can find no documentation of a
comprehensive ground water monitoring plan, no
effort to delineate the wetlands that appear to
encroach the northwest disposal area..., no
discussion or investigation into the status of
closed disposal areas which do not appear to
sustain grass or other vegetative cover.
The north burial area, the south burial area, the
Reasor Hill burial area, above ground vault (Mt.
Vertac), and the cooling water pond were all
remediated between 1984 and 1986 as part of a
Court-ordered remedy. The remedy generally
involved closing the Vertac plant cooling water
pond and the equalization basin and consolidation
of the sediments from these units into an
excavated area where earlier operators had buried
drums of waste. The burial areas were capped and
a French drain and leachate collection system was
installed around them. Ground water monitoring
wells were also installed and a ground water
monitoring program was initiated.
EPA generally disapproved of the remedial
approach, but its legal objections were
overturned. As such, these remedies are
considered to be final, and further action by EPA
on this areas is limited unless documentation of
22
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remedy failure is found.
Comment 33.
See also response to
47. Comment:
Page 3, Paragraph 4 of the Proposed Plan states
that soil concentration levels are based on what
"will be protective for persons reasonably
expected to be in contact with these soils." This
statement fails to note that EPA health-based
cleanup standards are to be conservative, not
reasonably protective. Additionally, this
rationale fails to embrace the twin mandate of
CERCLA to protect both human health and the
environment... No demonstration has been
presented that the proposed soils remediation
goals will provide adequate protection of ground
water resources and aquatic environments. The
concluding sentence of this paragraph notes
primarily that the preferred alternative is cost
effective. However, under existing EPA guidance
cost is not to be considered in preference to
technical considerations, except where the
difference in cost between to alternatives
represents a magnitude of order discrepancy.
Response: EPA believes that a remediation goal for dioxin of
5 ppb TEQ is protective of human health and the
environment assuming a commercial/ industrial
exposure scenario. See EPA's risk assessment
dated April 11, 1995, which is part of this
Administrative Record. This action level is being
applied to that portion of the site (southern 100
acres) where access will remain restricted to
future site workers and is conr ->red to be
conservative for that exposure scenario. A 1 ppb
dioxin action level will be required for all other
area of the site that will have unrestricted
commercial access. While ground water issues are
not being addressed in this ROD, they will,
however, be addressed in the ROD for Operable Unit
3. See also response to Comment 44.
48. Comment:
There exists a potential conflict of interest
involved with allowing a responsible party to
perform a risk assessment that will subsequently
determine remedial goals, given the negative
economic implications of more extensive, and more
protective, remedial work.
Response: EPA allowed Hercules to conduct the baseline risk
assessment and Monte Carlo risk modelling for the
Vertac site. After review of these documents and
23
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many discussions with Hercules and its contractors
on various assumptions used in the risk
assessments, EPA decided to conduct its own risk
assessment. Remediation goals for Vertac were
established from the EPA site-specific risk
assessment for Vertac, and not on Hercules'
product .
49. Comment:
EPA's justification for choosing 261 ppb an^
as the cutoff for off-site remediation appears to
be cost efficiency. We do not believe that cost
is a proper, or controlling, factor in determining
remedial goals whicn are per statute intended to
be health-based.
Responsa: The 261 ppb cleanup number presented in the
Proposed Plan for OU2 media should not be confused
with a remedial action goal for the site. It is
simply a number where EPA made a determination of
cost effectiveness for applying two different
treatment technologies. The health-based remedial
action goal for site soils was set a 5 ppb TEQ for
dioxin.
50. Comment:
Page 6, Paragraph 2 of the Proposed Plan gives the
impression that on-site landfilling, a non-
permanent, non-destructive alternative that does
not immobilize, detoxify, or reduce We*sic: volume
is preferable to on-site treatment, despite the
SARA-mandated preference for treatments.
Response: See response to Comment 34.
51. Comment
We request that EPA provide document a ^on of the
compliance and regulatory history of the APTUS
facility. Full explanation of any permit
suspensions, administrative orders, or notices of
deficiencies is also requested.
Response: EPA is no longer proposing to send contaminated
soil to the APTUS facility for treatment under
this Record of Decision. EPA has reevaluated the
necessity to treat dioxin-contaminated soil at the
Vertac site and since it is not considered to be a
principal threat at the site, other disposal
options have been selected in place of
incineration. See also response to Comment 34.
52. Comment:
We are uncomfortable with the assumption that
since unsampled areas of the site are downgradient
from areas of relatively low contamination, that
24
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no contamination is probable in those areas.
More and comprehensive characterization is
required and is a prerequisite to critical
remedial determinations.
Response: EPA disagrees. When examining the soil
contaminant data that were collected from over 460
different collection grids at the Vertac site,
patterns of contaminant distribution become
readily apparent. Site contamination is related
to specific process operations at specific site
locations and is also related to past site
disposal activities.
53. Comment
Page 15, Bullet 3 of the Proposed Plan identifies
porous bedding media as a potential problem, but
does not elaborate on potential contaminant
migration, corrective action, or sampling effort
to fully characterize the concern.
Response: EPA has no data that show whether porous bedding
media was actually used at the site around
underground conduits, i.e. , no plans or drawings
are available from early construction activities.
However, EPA has conservatively assumed that
porous bedding media may be present, and as such,
the proposed remedy will require that cuttoff
barriers be installed at specific locations along
these conduits to prevent any potential shallow
ground water flow along these lines.
54. Comment:
At page 17, Bullets 1 and 3 of the Proposed Plan,
EPA notes its goal to minimize cancer risks to
within the statutory mandate between 1/10,000 and
1/1,000,000. This is, however, a very broad range
of values, and requires an explicit statement of
the specific level of acceptable risk that EPA has
adopted for OU2 and the site in general.
Response: EPA's risk modelling for the Vertac site shows
that a commercial/ industrial worker exposed to
site soils remediated to 5 ppb dioxin or less will
be exposed on average to 0.67 ppb dioxin. The
risk estimated from the Reasonable Maximum
Exposure (RME) method is 1X10"*. Monte Carlo
modelling predicts the risk at the upper 95
percentile level for a 5 ppb cleanup to be 4X1Q~S.
Both are within EPA's acceptable exposure risk
range. See also in the Administrative Record
EPA's site specific risk assessment entitled
"Evaluation of Surface Soil Cleanup level
25
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55. Comment:
contaminated with 2,3,7,8-TCDD TEQs at the Vertac,
Inc. Superfund Site," dated April 11, 1995.
The proposed fish flesh monitoring program should
be modified to provide better information
responsive to on-site conditions. Specifically,
sampling should be scheduled for one event prior
to excavation activities, at the midpoint of
remedial activities, and a 30 days post-remedial
confirmation sampling.
Response: EPA was not proposing to conduct a new fish-
monitoring program. Rather, EPA was explaining
the results of the existing monitoring program
that is a requirement of the Off-site ROD issued
in September 1990. The existing program is
considered to be adequate for monitoring
contaminant concentrations in aquatic organisms in
Rocky Branch Creek and Bayou Meto.
56. Comnent:
At page 22, Paragraph 2 of the Proposed Plan EPA
takes the position that because public water is
available on and around the site, ground water is
not a potential pathway for human exposure. This
is not necessarily the case in that it is well
documented that ground water normally discharges
into proximate surface features. Therefore,
contaminated ground water from the site is likely
to discharge into Rocky Branch Creek which is a
potential human exposure route through both direct
contact and the food chain.
Response: EPA agrees that potential exposure pathways from
ground water sources may exist for the Vertac site
through dermal exposure and incidental ingest ion
exposures from primarily surface water features.
EPA's statement in the Proposed Plan was that the
ground water ingestion pathway (drinking well
water) was unlikely since Jacksonville is on a
public water supply.
Ground water exposure issues are not being
addressed in the Operable Unit Record of Decision.
They will, however, be addressed in the ROD for
Operable Unit 3.
57. Comment:
The additional characterization data for all
congeners for dioxin and furan needs to be
reflected in recalculated risk assessment values.
It is absolutely necessary that EPA show the
actual calculations related to the 20 percent
26
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elevation in risk when all dioxins and furans are
considered.
Response: See response to Comment 43.
58. Comment: Page 24, paragraph 2 of the Proposed Plan states
that 2,4-D contributed materially to an
unacceptable hazard index of 4 (1.0 is the
threshold). However, no soil remedial goals for
2,4-D are proposed.
Response: The commenter is correct. However, EPA need not
establish remediation goals for all contaminants
of concern at the site if such contaminants are
reduced to below levels of concern during the
remediation of another contaminant. Such is the
case for 2,4-D. When dioxin is remediated in
surface soils at the site below the specified
action level, 2,4-D concentrations will also be
well below a health based exposure levels.
Hercules Incorporated Comments
59. Comment: Although the plan acknowledges the existence of
the two areas, it fails to recognize unique area-
specific conditions when proposing surface soil
cleanup criteria, i.e., the plan provides for a 5
ppb dioxin (TEV) cleanup criterion for surface
soil for both the restricted and unrestricted
portions of the site.
Response: EPA disagrees. EPA made a conscious decision to
establish a soil cleanup level < the southern
restricted access portion of the site that would
be protective of a site worker, such that
protective clothing would not be required during
the conduct of daily activities. Several reasons
for this include: 1) The long term ground water
remediation efforts and site maintenance efforts
will be required, and thus individual site workers
will likely be required to be at the site a normal
work period; 2) it is difficult to enforce/monitor
how well health and safety requirements (i.e.
personal protective clothing requirements are
being maintained) over a long term operation, and
3); the Jacksonville Community felt that a "no
moon suits" requirement should be established for
the southern part of the site because of the
nearness to residential neighborhoods and the fact
that this site will be a part of their community
for the foreseeable future.
27
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60. Comment: The 5 ppb dioxin surface soil cleanup criterion,
however, is unnecessarily stringent and
inconsistent with a past dioxin cleanup
requirement of 20 ppb used at another
commercial/industrial site in Arkansas, e.g.. the
site in Arkwood, Arkansas, and at other sites.
Response: EPA disagrees that a 5 ppb dioxin surface soil
cleanup level is unnecessarily stringent, ""--
commenter failed to note that EPA's risk
assessment did not consider an exposure to dioxin
at a concentration of 5 ppb. Rather, EPA more
liberally looked ac the average concentration of
dioxin that would be present at the site after
remediaion of dioxin at 5 ppb occurred, which is
0.67 ppb. EPA calculated the risk from exposure
to future site workers based on this average
concentration and found the risk to be 1X10"*,
using EPA RME methodology. A cancer risk of
1X104 is the upper limit of the range (1X10"1 to
1X10"*) that EPA considers to be acceptable. Monte
Carlo modelling was also used by EPA to predict
the risk to a future site worker from exposure to
dioxin after remediaion at a 5 ppb action level,
the future risk was estimated at 4X10'5.
A 20 ppb cleanup level for dioxin (which equates
to a 2 ppb exposure concentration after
remediation), based on site-specific conditions,
would result in exposures that are outside of
EPA's acceptable risk range for both RME (2.7X10^*)
and Monte Carlo modelling (1.1X10^*).
EPA believes that it has appropriately established
a cleanup level for dioxin at the site that is
protective of human health.
61. Content: The EPA risk assessor incorrectly used EPA default
risk assessment guidance when selecting the amount
of skin area exposed to soil for workers wearing
the clothing described above. The risk assessor
used 25 percent as the percent of the total body
surface exposed every working day for twenty-five
years. This skin area corresponds to hands, arms,
face and lower legs being continually exposed.
For normal work clothing, i.e.. long sleeve shirt
and pants, EPA risk assessment guidance for
exposure to soil indicates that the skin exposure
should be 10 percent (reference made to the
"Dermal Exposure Assessment: Principals and
Applications, Interim Report," U.S. EPA, 1992)
28
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Response:
which corresponds to exposure of hands and face.
This factor alone will effectively reduce the
estimate of potential risk to future workers by
about 60 percent for any given soil cleanup
criterion.
EPA guidance referenced by the commenter, the
"Dermal Exposure Assessment: Principles and
Applications" st^es on pages 8-10 that "for soil
contact scenarios dermal exposure was expected to
occur at the hands, legs, arms, neck, and head
(McKone and Layton, 1986) with approximately 26
percent and 30 percent of the total surface area
exposed for adults and children, respectively.
Less conservative scenarios have limited exposure
to the arms, hands, and feet. The clothing
scenario presented above suggests that roughly 10
percent to 25 percent of the skin area may be
exposed to soil. Since some studies have
suggested that exposure can occur under clothing,
the upper end of this range was selected for
deriving defaults. Thus, applying 25 percent to
the total body surface area results in defaults
for adults of 5,000 cm2 and 5,800 cm2. The
defaults for children can be derived by
multiplying the 50th and 95 percentiles by 0.25
for the ages of interest."
The risk assessor also assumed that future site
workers would not conduct any of their activities
in those portions of the containment area that
have already been remediated. Under EPA
oversight, 40 percent of the containment area has
been remediated using clean off-site soil and is
currently contaminant free. The EPA risk assessor
ignores the fact that many of the site activities,
e.g., inspection and maintenance, mowing of capped
areas, measuring water levels in monitoring wells,
etc., currently and in the future will occur in
clean areas. Hercules believes that the risk
assessment for the future worker should reflect
this site information. If incorporated correctly,
this factor would reduce the predicted risk to
future workers by at least 40 percent because
future site workers are expected a
disproportionate share of time in clean areas.
Response: The worker exposure area as defined by Hercules
includes about 100 acres of the southern portion
of the site. This is considered to be an
extremely large exposure area. The exposure for a
62. Comment:
29
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site worker could be much less than the whole 100
acre site. It is currently not known what
specific activities will be required of future
site workers and the locations of the site that
they will be required to conduct their daily
activities. In EPA's risk assessment evaluation
of the soil cleanup level for the southern portion
of the site, the risk posed by exposure to site
soils after remediation at a 5 ppb cleanup level
was approximately 1X10"* based on RME calculations
and 4X10'5 using Monte Carlo risk estimates. These
risk numbers are based on an average exposure of
0.67 ppb for dioxin, which is the average
concentration of dioxin for all the southern
portion of the site that gets remediated. That is
not to say that some workers will not be exposed
to higher concentrations and others to lower
concentrations, depending upon the exact location
where work is conducted at the site. For example,
the cleanup scenario requires that any grid at the
site (each i~ approximately 5,000 sq. ft. in size)
with an average dioxin concentration greater than
5 ppb be covered with 1 foot of clean soil. Thus,
the dioxin concentration at that location is now
assumed to be half the detection limit or 0.15
ppb. Any grid that has an average dioxin
concentration of less that 5 ppb, say 4.9 ppb,
would be left undisturbed. For that particular
case, the actual exposure point concentration for
a worker at that location would be 4.9 ppb and not
the average of 0.67 ppb for the entire site. This
means that the risk associated with exposure to
this one grid or several adjacent grids if the
concentrations a^e similar, would be higher than
the average or approximately 8X10"* based on RME
and 3X10"* based on Monte Carlo, which are outside
of EPA's acceptable risk range. EPA, however,
considers it unreasonable to assume that site
workers will be exposed only to these grids.
Rather, EPA believes that site workers will be
exposed to a range of dioxin concentrations across
the site from 4.9 ppb to zero as they conduct
*:heir daily activities. Thus, EPA's risk
assessment reasonably predicts the risks
associated with future work conducted on the
southern portion of the site after remediation is
complete.
63. Comment: The EPA risk assessor also failed to consider that
remedial plans for the site which, although not
yet finalized, include relocation of most of the
30
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waste water treatment facilities into a clean
building within the containment area. Collection
and treatment of ground water will be the main
future activity within the containment area.
Therefore, future worker exposure to site soil
will be further reduced from that assumed by the
EPA risk assessor. Hercules has estimated that
over one-half of each worker's time in the
containment area will be spent on operating and
maintenance activities which will occur within the
clean building. This factor should also be
included in the site risk assessment.
Response: Recent conversations between EPA and Hercules have
indicated that the waste water treatment plant may
not in fact be relocated to a "clean" portion of
the site. EPA does not believe it appropriate to
reevaluate site exposure scenarios based on
unknowns. See also response to Comment 64.
64. Comment:
Two other inappropriate assumptions or procedures
were used by the risk assessor that resulted in an
overly stringent cleanup standard. One
inappropriate procedure was the use of a site-
specific bioavaliability factor of 10 percent that
was higher than any of the individual results
determined by the Rutgers University
bioavailability study for 2,3,7,8-TCDD conducted
with soils samples from the Vertac site. The
individual results ranged from less than 1 percent
to less than 9 percent. An average of the site-
specific results which had a geometric mean 2.3
percent more accurately descri>~ - the
bioavailability of dioxin for Vertac site soil.
In addition, the risk assessor used a slope factor
of 156,000 kg-day/mg for 2,3,7,8-TCDD that is
substantially greater than the slope factor of
100,000 kg-day/mg which corresponds to the risk-
specific dose of dioxin (0.01 grams TEV per
kilogram of body weight results in one additional
cancer in one million) stated in the plan (page
22) .
Response: a) The bioavailability study of 2,3,7,8-TCDD
conducted by Hercules for Vertac site soils was
reviewed by EPA and discussed with Hercules
personnel, Hercules contractors, and the author of
the report on several different occasions as the
study progressed and at the conclusion of the
study. EPA found the study results to be
inconclusive concerning whether the low
31
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measurements of bioavailability were attributable
to Vertac soils or to experimental error. The
study failed to show proper expected responses in
the positive control animals. It was not apparent
from the authors of the study that the experiment
was designed or implemented to determine a
reliable, reproducible bioavailability "factor" to
be used quantitatively in the manner proposed by
Hercules. Rather, their study seemed to b«
directed more toward establishing whether dioxin
in Vertac soils is bioavailable as determined by
liver enzyme responses and other bioassay
techniques, rather than producing specific
percentages of bioavailability to apply to human
risk calculations. In short, Callow and Meeker
(authors of the study) seem to attribute
qualitative significance to their study, but not
the quantitative significance which Hercules does.
Site-specific soil studies done at other Superfund
sites showed a wide degree of variation in
bioavailability. For example, Callow and Meeker
discussed a Times Beach soils study that showed
approximately 30 percent bioavailability. There
was no indication that an attempt was made to
characterize the soils (i.e., sand versus clay or
absorption capacity) to help correlate or explain
differences within Vertac soils or between Vertac
soils and Times Beach or other site soils. EPA
does not believe that the Hercules bioavailability
study for Vertac site soils was conclusive for the
reasons mentioned above. However, EPA gave
Hercules credit for conducting the study and
acknowledges that dioxin absorption from soil is
expected to be less chat absorption ^om corn oil
(55 percent is often used as the default
bioavailability for dioxin), thus an absorption
factor of 10 percent (the upper range of the
individual results obtained in the Hercules study)
was accepted by EPA and was used in EPA risk
assessment calculations for the site.
b) The statement by Hercules that M... 0.01 grams
TEV per kilogram of body weight results in one
additional cancer in a million" was improperly
cited from EPA's proposed plan. What EPA stated
was that 0.01 picograms TEV per kilogram of body
weight per day results in the incidence of one
additional cancer case in one million people.
According to the Risk Assessment Guidance for
Superfund Volume I, Human Health Evaluation Manual
(Part A), pages 7-15, the toxicity values in the
32
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65. Comment
Integrated Risk Information System (IRIS) database
should be used in EPA risk assessments. If
information is not available in IRIS, then the
toxicity values in the Health Effects Summary
Tables (HEAST) may be used. A toxicity value for
2,3,7,8-TCDD is not available on IRIS as of August
1995, but an oral and inhalation slope factor of
1.5E+5 (150,000) mg/kg-day is presented in the
HEAST database. The toxicity value of 156,000
mg/kg-day which was used in the Vertac risk
assessment was based on the Rat toxicity study
done by Kociba et al. in 1978. The study by
Kociba et al. was referenced in the HEAST and has
been used historically to evaluate risk from
exposure to dioxin and furans. Current
information from the EPA's dioxin reassessment
also does not change the slope factor for dioxin.
Hercules supports EPA's conclusion that dioxin-
contaminated soils can be safely disposed of in an
on-site hazardous waste landfill. Hercules does
not agree, however, that application of that
remediation technology should be limited to soil
containing less than 260 ppb dioxin. None of the
site soil is a principal threat, especially when
compared to the thousands of tons of concentrated
wastes which have been, or will be, destroyed by
incineration. Based on both the technical
effectiveness of landfilling dioxin-contaminated
soil and the very low cost effectiveness of
incinerating such soil, Hercules believes that all
excavated dioxin-contaminated surface soil should
be placed into the on-site hazardous waste
landfill that will be constructed as part of
Operable Unit 1 remediation. Landfilling will
eliminate the need to transport the soil over
public highways to an off -site incinerator,
shorten the remediation time, and eliminate short
term risks by not having to pre-process the soils
(removal of coarse rock fraction) prior to
shipment .
Raspons*: EPA agrees.
66. Comment
The Feasibility Study evaluated capping of
contaminated soil in place and found the
technology to be both technically and economically
appropriate for areas of low contamination
concentrations. The very low potential for dioxin
to migrate through soil, as supported by the low
bioavailability, is supportive of covering
33
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contaminated soil in place with a layer of clean
soil. Therefore, Hercules recommends that capping
for some areas of low contaminant concentrations
... in the containment area with clean soil be
selected as an optional remediation technology.
Capping some areas of low contaminant
concentration would have the additional benefit of
minimizing the size of the landfill. Hercules is
aware that the Jacksonville community would like
the landfill size to be minimized.
Response: EPA agrees. When FPA re-evaluated the future
landuse potential for the southern portion of the
Vertac site, i.e.. the southern 100 acres, EPA
concluded that because of the existing on-site
burial areas and landfills, the construction of a
new landfill as part of Operable Unit 1
remediation, and likelihood of long term on-site
ground water monitoring and treatment, these
operations would substantially reduce commercial
redevelopmer.1^ opportunities at this part of the
site.
Because the southern portion of the site will not
be used for commercial/industrial development,
other remedial options presented in the OU2 FS and
in the supplemental proposed plan, such as
capping, present a more cost effective means of
cleanup that is fully protective of human health
and the environment. The cap for Operable Unit 2
soils would involve covering the contaminated
surface soil with a 6 inch layer of compacted
soil, and a 6 inch layer of topsoil, and re-
vegetation. Drainage controls would be
implemented to prevent runon and runoff from
capped areas. The function of the cap is
principally twofold: 1) To pre—ent direct
exposure through dermal contact, inhalation, or
ingestion by future site workers maintaining the
restricted access portion of the site, and 2); to
prevent potential off-site exposure to human and
environmental receptors from the migration of
contaminated soils via various sediment transport
mechanisms.
Migration of dioxin-contaminated soils is
adequately addressed by the 1 foot soil cap
because:
• Dioxin has an extremely low solubility in
water and does not leach readily;
34
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• Site-specific studies have shown that dioxin
adheres strongly to fine grain particles and
soils with organic content of 3 percent or
greater, thereby further reducing its
leachability;
• The soil cap is not designed to protect
ground water at the site. Ground water is
heavily contaminated with high concentrations
of dissolved phase contaminants and non-
aqueous-phase liquids (NAPLs), and as such a
technical impracticability (TI) waiver will
be sought for this area of the site. Ground
water remediation will most likely entail
hydraulic containment of the plume;
• The construction of an impervious
infiltration barrier over a major portion of
the site could substantially complicate
ground water flow and contaminant migration
prediction, as well as affect the collection
of both dissolved phase contaminants and NAPL
recovery efforts in the existing French drain
system. Several years have been invested in
developing a good conceptual ground water
flow model for the site (which has been
confirmed through long term site testing and
monitoring), and as such few benei^cs can be
found for installing an impermeable cap, and;
• An increase in the thickness of the soil cap
would not add additional protection from
exposure for on-site work*- -~. They will be
conducting maintenance activities under an
approved health and safety plan that will
dictate the appropriate level of protection
should the need arise to breach any capped
areas. Increasing the thickness of the cap
also has certain negative aspects in that it
could increase the possibility of erosion in
areas graded from the cap surface to the
ground surface because the slope in these
areas would be greater.
67. Comment: The assessment of potential risk to human health
from exposure to contaminated soil in the
tetrachlorobenzene (TCB) spill area indicated that
500 ppm of TCB in soil provided an acceptable risk
if exposure of workers is limited. The FS
evaluated only two remedial technologies, thermal
desorption and incineration, for TCB-contaminated
35
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68,
69,
70.
soil. Although evaluation of other technologies
was focused on dioxin-contaminated soil, Hercules
believes these evaluations apply to TCB
contaminated soil as well. Specifically, Hercules
believes soil which contains up to ten times the
no-action level of 500 ppm TCB should be placed
into the on-site landfill for permanent
containment. Soil containing more than 5,000 ppm
TCB and any crystalline TCB should be sent off-
site for treatment in a RCRA facility. Although
incineration is the most likely treatment for
these materials, ths ROD for these materials
should allow for other permitted treatments or
recovery options to be evaluated and selected
during the remedial design period.
Response: EPA currently cannot comment on the
appropriateness of the Hercules proposal to
j.andfill TCB-contaminated soils with
concentrations between 500 ppm and 5,000 ppm
because it was not an option considered by EPA in
the Feasibility Study. In addition, EPA believes
that this cleanup option could not have reasonably
been anticipated by the public, and as such, must
be presented to the public for consideration or
comment prior to further action by EPA.
Pvil)lie Heating Comment•
Comment: Why hasn't a comprehensive health study, morbidity
study, or a census on adverse health effects been
conducted for the residents in Jacksonville.
Response: See response to Comment 38.
Comment: The Vertac site should be used as a dioxin
research facility where alternative treatment and
disposal technologies are developed and tested.
Response: See response to Comment 42.
Comment: EPA needs to hold a public referendum on all
possible alternatives for soils remediation,
including chemical dechlorination.
Response: Under the Superfund process each citizen has the
opportunity to review and comment on cleanup
alternatives proposed for each site. This
information is formally presented to the public in
the Feasibility study and Proposed Plan of Action,
and comments received are evaluated by EPA prior
36
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71. Comment:
to drafting a Record of Decision for the site.
Chemical dechlorination was one of the
technologies evaluated in the Vertac Operable Unit
2 Feasibility Study and was presented as one of
the options in the May 1995 Proposed Plan for on-
site soils. In addition, EPA discussed in length
many of the pros and cons associated with the use
of chemical dechlorination for dioxin-contaminated
soils at the public meeting held in Jacksonville
on June 15, 1995. EPA received over 300 written
responses or signatures concerning the proposed
cleanup for soi.Tc at the Vertac site, and only
three comments concerned chemical dechlorination.
EPA believes that the public has had an
opportunity to provide EPA input on the use of
chemical dechlorination at Vertac.
EPA needs to develop a study to evaluate the
potential migration of contaminated ground water
off-site.
Response: EPA has been eve.luating the condition of
contaminated ground water at the Vertac site over
the past several years and is currently in the
process of developing a Proposed Plan that will
present various cleanup alternatives and EPA's
preferred alternative for ground water remediation
at the Vertac site. See also response to Comment
44.
72. Comment: EPA needs to guarantee that there will be no
further on-site incineration.
Response: EPA cannot guarantee that if additional
remediation efforts are needed at the site that
they would not include on-site incineration. EPA
can, however, state that on-site incineration is
not a part of any current remediation efforts
slated for the site and that the on-site
incinerator used in the remedy for OU 1 has been
dismantled to the point that it would be cost-
prohibitive to reassemble it and return it to
operating condition.
73. Comment: There are concerns about fugitive emissions in the
moving of the dirt, including dust, salt, and ash,
and the salt soils, and salt spills around the
incinerator site. Have they been sampled, or are
they included in the sampling process?
37
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Response: See response to Comment 41 on dust suppression.
As a part of the cleanup operation for the
northern portion of the Vertac site, soil sampling
will be employed to ensure that dioxins and furans
are below the 1 ppb action levels set for this
area of the site.
74. Comment:
EPA should consider using the local abandoned
missile silos as permanent waste storage
facilities.
Response: This option was not considered by EPA in the FS,
and EPA is very doubtful ^aat it poses a very
realistic disposal alternative for dioxin-
contaminated wastes. EPA fails to see the
advantages is disposing of dioxin wastes in
missile silos over that of a hazardous waste
containment unit that was designed to hold
hazardous wastes.
75. Comment:
EPA should declare this a contaminated area,
permanently restrict access, and buy out nearby
homes and business properties.
Response: EPA disagrees. EPA believes that approximately 50
percent or 100 acres of the Vertac site can be
returned to commercial/ industrial reuse after site
cleanup efforts are complete. Access to the
remaining 100 acres of the site, i.e. , the old
process plant area, will be restricted and
engineering controls such as landfilling and
capping will be employed to ensure that
contaminants are controlled so that they will not
pose an unacceptable risk to nearby residents,
future site workers, or the environment.
Residential areas that were found to have site
contaminants above health-based levels were
remediated as part of a removal action back in
1987.
76. Comment:
Explain in terms of risk the difference between
the 20 ppb dioxin cleanup standard that Hercules
is proposing and EPA's 5 ppb dioxin cleanup level.
Response: First, the distinction between a cleanup standard
and an exposure concentration must be made. When
soils are cleaned up to a certain concentration,
say 5 ppb, the resulting concentration of
contaminants in the soil after remediation will
range from 4.9 ppb at their maximum for some areas
down to zero for others. So, a 5 ppb cleanup
38
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77,
Comment:
level will result in an exposure concentration
that will be the average of all the remediated
area.
Specifically for Vertac, if the site is cleaned to
20 ppb for dioxin, then the resulting average
dioxin concentration for the remediated areas will
be 1.8 ppb. The risk associated with being
exposed to 1.8 ppb of dioxin under a commercial
scenario ranges from 3X10"* based on RME estimates
to 1X10"4 for Monte Carlo estimates. These are
both outside EPA's acceptable risk range. A 5 ppb
dioxin cleanup, however, will result in an average
exposure concentration of approximately 0.67 ppb
dioxin. The risk associated with exposure at this
concentration for a commercial scenario is 1x10^*
for RME and 4X10-S for Monte Carlo. Both are
within EPA's acceptable risk range.
Will the portion of the site that is cleaned up
and tested to be below 5 ppb have unrestricted
commercial access, public access, or public use?
78,
Response: Access to southern portion of the site (fenced
area) will be restricted to site maintenance
workers. The Receiver for Vertac Corporation,
which holds title to the property, has indicated
to EPA a willingness to impose deed restrictions
on the property that will prevent the property
from being redeveloped.
The northern portion of the site will be cleaned
to a 1 ppb dioxin (TEQ) action "-vel and will have
unrestricted commercial/industrial use.
Generally, municipal zoning restrictions are used
to control the type of development that occurs on
a particular piece of property. When EPA
determines future site risks, guidance requires
that EPA evaluate the past use of the property,
and in most instances, future use of a piece of
property follows its past or historical use. EPA
generally is prohibited from restoring a site to a
future use that is above its historical use. See
response to Comment 31.
Comment: Does EPA's risk assessment address potential
exposure to children who may have access to this
site (the area that will have commercial
redevelopment) after the remediation is complete?
39
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Response: No. The portions of the site that will be
returned to productive use ( i . e . , the northern 100
acres) will have administrative controls such as
deed restrictions that will prevent future
development other than commercial and light
industrial. However, as a part of EPA's proposed
remedy, EPA will require that the northern portion
of the site be cleaned to a 1 ppb dioxin TEQ
action level. This action level has been used by
EPA as the cleanup standard for residential
properties adjacent to the Vertac property and
floodplain soils along residential stretches of
Rocky Branch Creek, and as such, any incidental
exposure from children accompanying a parent to
work would not pose an unacceptable risk to the
child.
79. Comment:
Clean the area of the site that will be used for
commercial/ industrial reuse to 1 ppb (dioxin) and
the fenced portion of the site to 5 ppb (dioxin) .
Response: See response to Comment 14.
80. Comment:
We encourage the restoration of the site to its
original condition prior to development by
Hercules and its predecessors. This includes,
removal of all structures, removal of all buried
waste, removal of all contaminated soila, and
restoration of ground water to background
standards. Partial restoration of the site is not
in the best interest of the community or its
future residents. The future use of the site
should be able to support any activity, including
parks, residences, cojtmercial establishments, or
industrial facilities.
Response: See response to Comment 31.
81. Comment
82.
The average person in Jacksonville would like to
see the site cleaned up to conditions that existed
prior to Hercules' operation, including the
excavation and off-site disposal of the existing
on-site landfills.
Response: See response to Comment 31.
Comment: It appears that some of the buildings at the site
may remain. All the buildings should be removed.
Response: See response to Comment 12.
40
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83. Comment: The EPA pole barn buildings at the northern
portion of the site should be cleaned and left in
place. These building could be used by the city
as a new recycling center.
Response: The disposition of the existing pole barns on the
site are not part of the proposed remedy for OU2.
However, EPA is willing to clean and leave these
structures in p]-*~e if they are considered to be
valuable. Agreement from the City and the Vertac
Receiver will be sought should the City and the
Receiver have such an interest.
84. Comment: Highly contaminated soils should be treated or
taken off-site rather than placing all that soil
into an on-site landfill.
Response: EPA has determined that off-site disposal of the
highly contaminated soils is not cost-effective
and affords only minimal additional protection
over secure containment on-site in a RCRA Subtitle
C landfill.
85. Commen^: The salt and ash residuals from the completed
incineration operation should not go into the on-
site landfill.
Response: EPA is presenting information to the public in an
Engineering Evaluation/Cost Analysis which will
explain options being considered by the Agency for
the disposal of approximately 40,000 drums of salt
and ash generated during the on-site incineration
of drummed herbicide wastes and approximately
1,000 tons of pallets used in the storage of these
wastes. EPAs preferred alternative for salt, ash
and pallets is containment in an on-site RCRA
•Subtitle C landfill. Citizens will have 30 days
to comment on EPA's proposal when it is released.
86. Comment: The restricted access portion of the site should
be much smaller than that proposed. Minimize the
portion of the site that will remain fenced.
Response: See response to Comment 11.
87. Comment: We had origionally hoped that while the
incinerator was operating out at the site that all
the contaminated soil would have been processed,
which would have allowed for a smaller landfill.
If there are other technologies that could be used
41
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at the site to remediate the soils and reduce the
size of the landfill, they should be considered.
Response: Other technologies were evaluated in the
Feasibility Study for treating on-site soils, but
were not adopted by EPA as the preferred
alternatives for OU 2.
88. Comment
The citizens of Jacksonville, the business
community, the civic clubs, and the city officials
all are saying the same thing, and that is, clean
it, restore it, and give us back an area at least
equivalent to what we started out with. If some
waste must be left out there, make it as little as
possible.
Response: See response to Comment 31.
89. Comment
EPA has stated that the total amount of dioxins
and furans at the site are approximately 20
percent high-- as toxicity equivalents than for
2,3,7,8-TCDD alone. The dioxin reassessment
indicates that the ratio should be approximately
10 times greater than for 2,3,7,8-TCDD alone. How
does EPA derive the 20 percent figure?
Response: The 20 percent number used by EPA was based on
site-specific sampling conducted at Vertac. In
1994, five areas at the Vertac site were resampled
using EPA Method 8280 to determine the dioxin and
furan congener concentrations for those areas.
The analytical results from each area was used to
calculate a Toxic Equivalency (TEQ) concentration
for the sample collected, and the ratio of
2,3,7,8-TCDD to TEQ was determined. The ratio of
2,3,7,8-TCDD to TZQ ranged between 0.73 and 1.00.
This suggests that other dioxin and furan
congeners are present at the site that would
contribute to the overall dioxin toxicity
calculated for site. As a result of the dioxin
resampling effort, EPA is requiring that all soil
grids at Vertac site be remediated for dioxin and
furans expressed as 2,3,7,8-TCDD toxicity
equivalents.
90. Comment:
Has EPA evaluated the various isomers of
tetrachlorobenzene (TCB) from the spill area to
determine the appropriate cleanup level, or has it
just considered a common potency for all. Some of
the isomers are dioxin-like and this should be
factored into the cleanup determination.
42
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Response: EPA evaluated the toxicity of tetrachlorobenzene
and some of its isomers from the data available in
EPA's Integrated Risk Information System (IRIS)
database. The studies used to develop the
reference dose (RfD) for tetrachlorobenzene
included the evaluation of 1,2,4,5-
tetrachlorobenzene, 1,2,3,4-tetrachlorobenzene,
and 1,2,3,5-tetrachlorobenzene isomers.
91. Comment: Has EPA evaluated other dioxin-like compounds at
the site such as chlorinated biphenalenes? These
compounds are as toxic as dioxins and are expected
to be present and could radically change the risk
assessment.
Response: During the remedial investigation of the site
Hercules, Incorporated evaluated compounds in site
soils based on raw materials used at the site,
manufacturing intermediates, and finished
products. These compounds included compounds such
as toluene, chlorinated herbicides, chlorinated
phenols and dioxin. Because the history of site
operations was known, extensive screening for
numerous other compounds was not conducted.
92. Comment: EPA should considered using other treatment
technologies such as chemical dechlorination, base
catalyzed decomposition, or bio-remediation to
destroy the approximately 2,000 tons of soils
slated for off-site incineration. Even if these
technologies do not get the dioxin contamination
down to the cleanup standard, it would have
reduced the dioxin level to a c'-^ree that it could
be dealt with in other ways.
Response: Both chemical dechlorination and biological
treatment were evaluated in the Vertac Operable
Unit 2 FS. Biological treatment using "white rot
fungus" was found to be in the developmental
stage, and limited bench scale tests have been run
on contaminated media containing 2,3,7,8-TCDD.
Currently no venders offer this remediation
service commercially.
Chemical dechlorination along with base catalyzed
decomposition (BCD) were also evaluated and found
to be successful in treating dioxin-contaminated
media. Most tests conducted to date have been
either bench scale tests or field trial tests and
considerable additional testing would most likely
be necessary to confirm the efficiency of this
43
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93,
comment:
94,
Response:
Comment:
95.
technology for Vertac soils. One of the major
concerns that has been raised during on-site
incineration was the health effects associated
with emissions from the incinerator. The Region
also considered those concerns when it evaluated
whether to pursue chemical dechlorination or BCD
for soil remediation at Vertac. Information
available from a test conducted at the Koppers
Superfund site showed that dioxin and furan
emissions had to be addressed with additional
engineering controls before the full scale
operation could proceed. Therefore, EPA did not
prefer this option for the small amount of soil
that would have required treatment at Vertac.
The dioxin data collected for the Vertac site
soils was for 2,3,7,8-TCDD only and not toxicity
equivalents. Why were equivalents used in the
risk assessment?
See response to Comment 43.
In the risk assessment a gastrointestinal
absorption of 0.55 was assumed for TCDD
equivalents ard was derived from the U.S. EPA's
1989 Human Health risk guidance. Is that document
still valid after the dioxin reassessment.
Response: Yes.
Comment: What criteria did EPA use to define the 260 ppb
cutoff for dioxin soil treatment and landfilling,
i.e., your determination between high
concentrations and lew concentrations. It looks
as though it could have been entirely economic.
Response: The 260 ppb treatment level for dioxin-
contaminated surface soils was based primarily on
a cost/benefit balance. The balance that EPA
weighed was the high cost associated with off-site
incineration and the reduction of toxicity or
mobility of soil contaminants through treatment.
EPA looked at the reduction in the total amount of
dioxin that would be achieved by incrementally
incinerating the most highly contaminated grid at
the site down to the least contaminated, and the
resulting cost for that incineration. What was
found was that by incinerating the 8 most highly
contaminated grids at the site approximately 70
percent of all the dioxin in site soils was
destroyed. However, by incinerating the ninth
44
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9 6. Comment:
Response;
97,
98,
Comment:
Response:
Comment:
Response:
99,
Comment:
Response:
grid, only an additional 0.5 percent was destroyed
at a cost of an additional $1 million. After
treatment of the 8th grid, it became apparent that
treatment of additional grids yielded little
additional benefit.
Who developed Monte Carlo Modelling? My
indication is that industry actually developed
Monte Carlo in cr^er to raise the cleanup levels
at various sites.
Monte Carlo probabilistic modelling is a
statistical application that nas been used in a
wide variety of fields to evaluate population-type
data. This modelling technique is widely used by
researchers in universities, industry, and the
government. This modelling technique is unique in
that it looks at data as a distribution for a
given input parameter, rather than as a fixed
point. Application of Monte Carlo modelling does
not result in laxer cleanup standards for a given
contaminant.
Is the landfill that is to be constructed under
the ROD for Operable Unit 1 going to be built to
RCRA hazardous waste specifications?
Yes. The on-site landfill will be constructed to
RCRA Subtitle-C standards.
EPA should consider reducing the toxicity of the
soil through treatment prior to putting it into
the on-site landfill, even if requires that
several different alternatives be used.
From a cost/benefit perspective, there is very
little benefit from pretreating dioxin-
contaminated soils to reduce toxicity prior to
disposal into a secure RCRA Subtitle C landfill.
The Subtitle C landfill will be designed and
maintained to strict standards, and therefore
exposure to waste materials placed in the landfill
would be considered a very remote possibility.
Is EPA considering capping any of the dioxin-
contaminated soil at the site as Hercules is
proposing?
Yes. In the proposed plan, EPA had origionally
envisioned that approximately 50 percent of the
southern 100 acres of the site would eventually be
45
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returned to commercial/industrial use. However,
after reevaluating the long term operational and
maintenance requirements for this area of the site
(i.e., maintaining the caps on the existing site
burial areas and the RCRA Subtitle C landfill, and
operation and maintenance of the ground water
treatment system), EPA believes that these
operations will substantially reduce the chance
for extensive future redevelopment opportunities
on the southern 100 acres. Because access to this
area of the site will remain restricted (except
for site maintenance workers), other remedial
options presented in the OU 2 FS and set out in
the OU 2 Proposed Plan, such as capping, present a
more cost effective means of cleanup that is fully
protective of human health and the environment.
46
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ATTACHMENT B
SUPPLEMENTAL
RESPONSIVENESS SUMMARY
The Environmental Protection Agency (EPA) has prepared this
Supplemental Responsiveness Summary in response to comments
received at the open house held in Jacksonville, Arkansas, on
March 5, 1996, and during the public comment period that ran from
.larch 6, 1996, to April 29, 1996, regarding the Supplemental
Proposed Plan of Action for Operable Unit #2 (OU2) media at the
Vertac Superfund Site.
This Responsiveness Summary addresses comments received upon
the Supplemental Proposed Plan for OU2, and does not address
those comments EPA received on the original Proposed Plan for OU2
dated May 23, 1995. EPA provided the public with its response to
those comments on March 5, 1996, and those responses are attached
to this ROD as Attachment A.
Written comments on the May 1995 Supplemental Proposed Plan
were submitted by the Arkansas Department of Pollution Control
and Ecology (ADPC&E), Hercules, Incorporated (Hercules), State
Senator Bill Gwatney, the Concerned Citizens Coalition, the
Environmental Compliance Coalition, the Jacksonville Chamber of
Commerce, the Jacksonville Commerce Corporation, City of
Jacksonville Office of Economic Development, the Jacksonville
Serotoma Club, the Jacksonville Lions Club, the Arkansas Peace
Center, Vietnam Veterans of America, the Environmental Health
Association of Arkansas, Jacksonville Mothers *nd Children's
Defense Fund, and numerous concerned citizens.
As was explained in detail within the Supplemental Proposed
Plan issued on February 26, 1996, EPA Administrator Carol M.
Browner issued a series of administrative reforms tor the
Superfund Program on October 3, 1995. One purpose of those
reforms was to control remedy costs and to promote cost
effectiveness, and the reforms directed EPA to base site cleanup
decisions on reasonably anticipated future land usage and
reasonable contaminant exposure scenarios based on the future
land usage.
As a result of those reform measures, and due to the ongoing
deadlock over the Federal budget occurring at the time, Region 6
revised the proposed plan of action for OU2 and developed the
Supplemental Proposed Plan issued on February 26, 1996. That
supplemental plan eliminated the off-site incineration component
of the original proposed plan, included capping of soils having
dioxin concentrations between 5-50 parts per billion (ppb), and
proposed on-site landfilling of soil contaminated with dioxin
concentrations in excess of 50 ppb.
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The following are the comments received by EPA Region 6
during the 45-day comment period between March 6, 1996, and April
29, 1996, and the responses from the EPA are included below each
comment.
1) Comment: The commenter is opposed to constructing the on-
site landfill on the west side of the Rocky Branch CTO^IC and
stated that it would be more desirable to site the landfill
within the French drain system since the land on the west
side is considered "clean." Also, this commenter expressed
some concern with respect to the continued integrity of the
ground water monitoring wells.
Response: The siting of the landfill is considered
appropriate since it is on-site and within the general area
of contamination at the Vertac site. Based on numerous
comments during meetings with the community, the most
desirable location was west of Rocky Branch Creek where the
new landfill could be "out of site - out of mind." See
response to comment #34 in the Original Responsiveness
Summary in Attachment A.
The Hercules, Inc., a potentially responsible party (PRP),
will be conducting continuous groundwater monitoring at the
site. More information on ground water will be included in
the ROD for the Groundwater operable Unit (OU3), wnich EPA
plans to issue concurrently with the ROD for OU2.
2) Comment: The commenter (Hercules, Inc.) provided two
letters stating that the trichlorobenze (TCB) and TCB-
contaminated soil having TCB concentrations between 500 ppm
and 5,000 ppm should be landfilled on-site, bu_ agreed with
EPA that the TCB above 5,000 ppm should be incinerated off-
site.
Response: The on-site landfilling of TCB-contaminated soils
above 500 ppm was not an option considered by EPA in the
Feasibility Study, and therefore was not presented to the
public for comment. In addition, in the ROD for OU2, EPA
has chosen to consolidate within the on-site RCRA Subtitle C
hazardous waste landfill low level threat material having
the similar characteristic of dioxin contamination.
However, the TCB-contaminated soils with concentrations
between 500 and 5,000 ppm TCB do not share that common
characteristic. In addition, because Hercules' proposal has
not been held out for public comment, EPA cannot include
that proposal within its remedy decision for OU2.
3) Comment: The commenter stated that the existing fenced
areas at the site were unacceptable since the fence along
the south side of the site is considered a detriment to
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property values in the area. The commenter further stated
that the site should be completely remediated so that the
site could be "useful" in the future.
R«sponsa: One of the EPA's goals with respect to the remedy
selected for OU2 is to allow the greatest amount of the site
to be unrestricted by such structures as fencing to permit
the commercial redevelopment of the greatest amount of the
site. However, EPA will not know the extent of the fencing
that will be necessary for areas around the eastern and
southern portions of the site until the remedial
design/remedial action phase of the OU2 remediation.
Nonetheless, the northern and western fenced areas are
around the existing landfills, and the French Drain must
remain in place due to the fact that those areas were
delineated by a 1984 order of the U.S. District Court for
the Eastern District of Arkansas. In addition, it will be
necessary to maintain some fencing around areas where ground
water extraction and monitoring wells currently are located
or will be placed upon the execution of the ground water
operable unit ROD (OU3) to protect those wells and to
prevent trespassers from interfering with them. Finally,
fencing will also have to be maintained around the existing
wastewater treatment plant since that facility will continue
to be operated during the extended periods of operation and
maintenance (O & M) for various of the site's operable
units .
With respect to the comment regarding a complete remediation
of the site, EPA believes that the remedy selected in this
ROD for OU2 allows the greatest amount of the site's future
useful reuse in a manner that is consistent with the new
direction of the Superfund program and that meets the
public's general approval.
4) Comment: The commenter provided voluminous petitions from
local citizens, and numerous other letters from individuals,
endorsing and reiterating the preference for the
Jacksonville Plan.
While EPA acknowledges tne merits of the
Jacksonville Plan, it is not cost effective when evaluated
along with the other eight criteria set out in the Superfund
statute for evaluating Superfund remedies. The remedy
selected in the ROD for OU2 results in a cost effective
remedy that is protective of the human health and the
environment, recognizes the reasonably anticipated future
land use for the site, which allows for a substantial amount
of the site to be redeveloped for commercial /industrial
uses, is supported by the State of Arkansas, and is
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consistent with the Agency's strategy for dealing with low
level threat wastes.
5) Comment: The commenter expressed concern about reduced
property values of real estate in areas adjacent to the site
to the west and requested that all material that might
constitute a hazardous waste be removed from the site
immediately. The commenter also requested that a public
statement be made when any and all of the hazardous wastes
have been removed from tho site so that it would be suitable
for industrial use. Finally, the commenter stated that if
the requests could not be performed then adjacent landowners
should be compensated for the true loss of value to the
property.
Response: As discussed earlier in this Responsiveness
Summary, a 1984 Court Order resulted in the permanent
location of several unlined landfills and the French drain
system on-site. In addition, as discussed in the OU2 ROD,
EPA considers the material to be consolidated within the on-
site RCRA Subtitle C hazardous waste landfill to constitute
low level threat media. The Agency has stated in the
National Contingency Plan (NCP), 40 CFR Part 300, that the
preferred method of addressing such low level threat media
is containment, and that the use of the technologies
employed in constructing, operating, and maintaining such a
hazardous waste landfill have been proven. Therefore, the
on-site containment of low level threat media within the on-
site RCRA Subtitle C landfill is appropriate in light of the
above comments and when considering that the 1984 Court-
ordered remedy resulted in the on-site burial of principal
threat materials in unlinod landfills that do not meet the
technological standards of the RCRA Subtitle C unit
currently being constructed.
Nonetheless, the remedy selected in this ROD will result in
a substantial amount of the site being available for
commercial/industrial redevelopment. Upon completion of the
OU2 remedy, the public will be made aware of the fact that
those portions will be available for such redevelopment.
Finally, the conditions at the site are not due to the
actions of the Federal government, and therefore, any loss
of property value is not compensable by the United States or
any of its agencies.
6) Comment: The commenter offered financial management
services and stated that a local bank could provide direct
deposit and electronic transfer capabilities. Also, the
commenter further stated that the EPA was spending more
money on the cleanup than necessary.
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Response: There is no known need for electronic transfer
capabilities to fund this project. In addition, EPA believes
that the remedy selected for OU2 is cost effective and fully
protective of the human health and the environment.
Therefore, EPA disagrees that it is spending more money at
the site than is necessary. Furthermore, it is the intent
of EPA to order Hercules, Inc., to perform the OU2 remedy.
7) Comment: The commenters stated that there has been economic
damage to the City of Jacksonville because of the publicity
surrounding the Vertac site. Before Vertac, Jacksonville
was one of the fastest growing communities in the area, and
as a result of the Vertac situation, adjacent communities
such as Cabot and Sherwood have experienced economic and
population booms. The City of Jacksonville Chamber of
Commerce has formed an organization to purchase industrial
property to enhance recruitment opportunities for potential
industry and associated jobs. The Commenter has urged the
EPA to clean the northern portion of the site to 1 ppb and
is eager for the EPA to donate this property to the City of
Jacksonville so that this land can be included in industrial
marketing efforts. The commenter further requested that
careful consideration should be given to the strip of
property along Marshall Road for long term future
development as it relates to cleanup levels.
Response: The EPA recognizes that the City of Jacksonville
has suffered a continued economic loss as a result of the
Vertac site. However, the cleanup standards included in
this ROD will allow future use of the northern portion of
the site and will result in an average d^ ~vin concentration
of 1 ppb or less. Property along Marshall Road will be
cleaned to a dioxin concentration of 5 ppb thereby providing
for future redevelopment. Due to the long term operation
and maintenance (O & M) activities necessary with respect to
the wastewater treatment plant, ground water extraction and
monitoring wells, and the existing landfills within the
southern portion of the site, future land use exists for
only a portion of the southern property. The risk
assessments performed for OU2 have established that soil
concentrations of up to 5 ppb dioxin are fully protective
for future commercial/industrial land use.
Finally, while the Vertac site belongs to the Vertac
Receiver, and is not the property of the EPA, EPA has and
will continue to encourage the future redevelopment of all
available remediated portions of the site.
8) Comment: The commenter (the Department of the Interior (
DOI)) has stated that based on numerous previous studies,
unacceptable levels of TCDD (dioxin) in sediments already
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exist in Rocky Branch Creek and Bayou Meto; and that if the
source of contamination is not controlled, even more dioxins
will be loaded into this system which would pose an
unacceptable risk to fish, mammals and birds. Further, the
commenter indicated that the proposed capping of the
southern portion of the site does not provide a permanent
remedy since dioxin contamination can be uncovered during
flood events, resulting in continued loading of dioxin into
the system.
Response: There is no doubt that dioxin has been released
to Rocky Branch Creek and subsequently into Bayou Meto.
However, the remedy selected in this ROD does not include a
capping component, as was recommended in the Supplemental
Proposed Plan for OU2. Instead, the remedy selected in this
ROD will result in the excavation and consolidation within a
RCRA Subtitle C hazardous waste landfill of dioxin
contaminated soils at concentrations of 5 ppm and above for
the entire site. EPA data indicate that the average post-
remediation soil levels will be at or below 1 ppb. The
excavation and on-site consolidation of soils with dioxin
concentrations of 5 ppb and above will provide for
commercial/industrial remedial actions. Therefore, the
implementation of the remedy selected in this ROD will
eliminate dioxin concentrations in site soils, excepting the
areas subject to the 1984 Court Order, in excess of 5 ppb,
which will effectively eliminate those soils as a source of
off-site contamination. Finally, because storm water run-
on/run-off measures will be implemented in connection with
the remedy selected in this ROD, site soils or surface run-
off waters will be prevented from leaving the site, and most
storm waters will be captured and treated in t -. on-site
wastewater treatment facility.
9) Comment: This comment was provided by the City of
Jacksonville by Resolution #47 (#2-96) which opposed the
modification of the original proposed plan issued May 1995,
and reiterated support of the Jacksonville Plan.
Response: With the exception of the off-site incineration of
up to eight highly-contaminated grids, the remedy selected
in this ROD is substantially similar to the remedy proposed
in EPA's original May 1995 Proposed Plan for OU2. As
discussed above, the Jacksonville Plan, while having some
merit, is not a cost effective remedy that takes fully into
account the reasonably anticipated future land use for the
site or acknowledges that the OU2 media constitute low level
threat media, as opposed to principal threat media.
10) Comment: This comment is a summary of numerous letters and
petitions from various members of the Jacksonville community
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expressing concern with EPA's proposal to "reduce the scope"
of the cleanup of the Vertac site. Also, included in the
letters and petitions is a statement supporting the
"Jacksonville Plan."
Response: As discussed in the response to Comments 5 and 10,
EPA believes that the remedy selected in this ROD is fully
protective of the human health and the environment, is cost
effective, and meets with general public approval.
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ATTACHMENT C
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STATE OF ARKANSAS
DEPARTMENT OF POLLUTION CONTROL AND ECOLOGY
8001 NATIONAL DRIVE, P.O. BOX 8913
LITTLE ROCK, ARKANSAS 72219-8913
PHONE: (501) 682-0831
FAX: (501) 682-0880
September 16, 1996
Jane Saginaw
Regional Administrator
U.S. Environmental Protection Agency
1445 Ross Avenue
Suite 1200
Dallas, Texas ^5202
Dear Ms. Saginaw:
This letter is to inform you that the Arkansas Department of
Pollution Control and Ecology (ADPC&E) formally concurs with the
Operable Unit 2 Record of Decision (ROD) and the amended 1990 Off
Site ROD for the Vertac Superfuni Site.
ADPCScE also concurs with the ROD for Operable Unit 3 provided that
any changes to the ground water plume containment trigger levels
will be more stringent than those which are currently contained in
the ROD. In addition, ADPC&E must be involved in the decision
making process should changes to the trigger levels become
necessary.
I commend your staff in their efforts in achieving this goal.
Sincerely,
Randall Mathis
Director
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