United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R04-90/071
March 1990
Superfund
Record of Decision:
Dubose Oil Products, FL
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50272-101
REPORT DOCUMENTATION i. REPORT NO. *•
PAGE EPA/ROD/R04-90/071
4. Title and SubHtto
SUPERFUND RECORD OF DECISION
Dubose Oil Products, FL
First Remedial Action - Final
7. Autnor(e)
9. Performing Organization Name and Addrma
1 2. Sponaoring Organization Nam* and Addreea
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
3. Reclpienfa Accaaalon No.
S. RaportDat*
03/29/90
6.
a. Parlorming Organization Rapt No.
10. ProjectfTaak/Work Unit No.
11. Contract(C) or Grant(G) No.
(C)
<0
13. Typa ol Report 1 Parlod Covarad
800/000
14.
15. Supplementary Notaa
18. Abetract (Umrt: 200 worda)
The 20-acre Dubose Oil Products site is an inactive waste storage, treatment,
recycling, and disposal facility in Cantonment, Escambia County, Florida. Surrounding
land use is primarily rural agricultural. The site overlies a deep aquifer, which
serves as a drinking water source for area residents. Site operations began in 1979,
and included thermal treatment of waste oil, petroleum refining wastes, oil based
solvents, and wood treatment wastes; steam heating of spent iron/steel pickle liquors;
and rock salt filtration of waste diesel fuel. Liquid waste was transferred from
tanker trucks and drums to onsite treatment tanks for these processes. Empty drums
were either sold or crushed and buried onsite. Operations ceased in 1981, and the
site owner commenced closure of the site without a proper closure plan. Unauthorized
closure activities included excavation of buried drums (causing some drums to be
punctured), operation of an aeration system to remediate onsite drainage ponds, and
movement of contaminated material with heavy equipment. A State emergency response
action in 1985 included excavation and onsite vaulting of 38,000 cubic yards of
contaminated soil and the offsite disposal of onsite drums. Site investigations in
1988 identified'the soil containment vault as the principal contaminant source and
(See Attached Page)
17. Document AnaJyaia a. Daecriptora
Record of Decision - Dubose Oil Products, FL
First Remedial Action - Final
Contaminated Media: soil, sediment, gw, sw
Key Contaminants: VOCs (benzene, TCE, toluene, xylenes), organics (phenols, PAHs)
idTarma
c. COSAT1 HaM/Group
18. Availability Statement
19. Sacurfty Claaa (Thia Report)
None
20. Security Claaa (TW» Paga)
None
21. No. ofPagaa
65
22. Prloa
(See ANSI-Z39.18)
Saa /naffuctfona on fiemerae
LfHM at fat (*
(Formerly NTIS-3S)
Department of Commerce
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EPA/ROD/R04-90/071
Dubose Oil Products, FL
First Remedial Action - Final
Abstract (Continued)
revealed contamination above health-based levels of the shallow aquifer beneath the site,
in onsite surface water, and sediment. Investigations showed that the deep aquifer
contained extremely low to undetectable levels of contaminants, which were below drinking
water standards. This Record of Decision (ROD) addresses final remediation of source
areas and onsite shallow ground water. The primary contaminants of concern affecting the
soil, sediment, ground water, and surface water are VOCs including benzene, TCE, toluene,
and xylenes; and other organics including PAHs and phenols.
The selected remedial action for this site includes excavating the top 20 feet of vault
soil containing low-level contamination and disposing of soil in an onsite ravine area;
excavating the remaining vault soil and treating by aerobic biodegradation, which
includes windrowing of soil on a concrete slab, addition of microbial seed and nutrients,
and aeration; disposing of treated soil onsite in the ravine area; placing a two-foot
soil cover over the vault area and the ravine area; treating soil leachate from the
windrowing process using filtration and either carbon adsorption or UV oxidation followed
by onsite discharge to surface water; draining and filling of onsite ponds; installing
surface water runoff controls; conducting ground water and soil monitoring; restoring
ground water by natural attenuation; and implementing institutional controls including
deed and ground water use restrictions. The estimated present worth cost for this
remedial action is $3,008,000, which includes an annual O&M cost of $115,000 for years 0
to 5 and $10,000 for years 6 to 10.
PERFORMANCE STANDARDS OR GOALS: Cleanup standards for leachate discharge are based on
the more stringent of Federal or State ARARs and include benzene 1 ug/1 (State), TCE
3 ug/1 (State), xylenes 50 ug/1 (State), and PNAs 10 ug/1 (EPA detection limit). Soil
cleanup goals are based on either leaching potential (LP) or health-based criteria (HBC)
and include benzene 10 mg/kg (HBC), TCE 0.050 mg/kg (LP), xylenes 1.5 mg/kg (LP), and
PAHs 50 mg/kg (LP).
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RECORD OF DECISION
DECLARATION
Site Name And Location
Dubose Oil Products Site
Cantonment, Escambia County, Florida
Statement Of Basis And Purpose
This decision document presents the selected remedial action for the
Oubose Oil Products Site in Cantonment, Florida, developed in
accordance with CERCLA as amended by SARA and, to the extent
practicable, the National Contingency Plan. This decision is based
on the Administrative Record for this site.
The State of Florida concurs with the selected remedy.
Assessment: Of The Site
Actual or threatened releases of hazardous substances from this site,
if not addressed by implementing the response action selected in this
Record of Decision (ROD), may present an imminent and substantial
endangerment to public health, welfare and the environment.
Description Of The Hnafiilj/'
The selected remedial alternative will be both the first and the
final remedial action for this site. This alternative will use
biodegradation to treat the contaminated soils to levels that are
within acceptable risk levels for human health and the environment.
This remedy will not allow for further contamination of the
groundwater.
The major components of the selected remedy include:
o Excavation of the top twenty feet of vault soils, shown in
thigj RI to be uncontaminated, and placement of those soils
into the ravine area;
o Transformation of the hog barn area into a process area
where the batch bioremediation system will be installed;
o Excavation of the remainder of the vault soils in separate
batches, bioremediation and disposal in the ravine area;
o Drainage and filling of the onsite ponds;
o Placement of a two foot topsoil layer over the ravine and
former pond area, grading and vegetation;
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o Installation of surface water runoff controls to accommoc ^
seasonal precipitation;
o Groundwater monitoring;
o Additional soil sampling during the remedial design to
confirm location of "hot spots" of contaminated soil outside
of tha vault. .
o Deed restrictions to preclude inappropriate future use.
Declaration
The selected remedy is protective of human health and the
environment/ attains Federal and State requirements that are
applicable or relevant and appropriate to the remedial action, and is
cost-effective. This remedy satisfies the statutory preference for
remedies that employ treatment that reduces toxicity, mobility or
volume as a principal element and utilizes permanent solutions and
alternative treatment technologies to the maximum extent practicable
for this site.
Because this remedy will result in low levels of hazardous substances
remaining onsite, a review will be conducted within five years after
commencement of remedial action to ensure that the remedy continues
to provide adequate protection of human health and the environment.
Date Greer C. Tidwell
Regional Administrator
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RECORD OF DECISION
SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
DUBOSE OIL PRODUCTS SITE
CANTONMENT, ESCAMBIA COUNTY, FLORIDA
PREPARED BY:
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
ATLANTA, GEORGIA
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TABLE OF CONTENTS
1. 0 Introduction 1
2.0 Site Name, Location and Description 1
2 .1 Area Land Use 2
2.2 Surface Water 2
2.3 Groundwater 3
3 . 0 Site History and Enforcement Activities 4
4.0 Community Relations 8
5.0 Summary of Site Characteristics 8
5.1 Contaminant Source Investigation 9
5.2 Onsite Soils and Vadose Zone 11
5.3 Groundwater 12
5.4 Surface Water and Sediment 12
5.5 Air Investigation 13
5.6 Bio-Treatability Study 13
5.7 Contaminant Fate and Transport 14
6 .0 Summary of Site Risks 15
6.1 Selection of Indicator Chemicals 15
6.2 Exposure Assessment Summary 16
6.3 Toxicity Assessment 16
6.4 Potential Carcinogenic and Noncarcinogenic
Contaminants 17
6.4.1 Noncarcinogens 17
6.4.2 Carcinogens 18
6.4.3 Environmental Risks 18
7.0 Remedial Action Objectives and General
Response Actions 18
7 .1 Site Remedial Action Objectives 18
7.2 Water 19
7.3 Soils 19
8.0 Description of Alternatives 20
8.1 Overall Objectives 20
8.2 Alternative 1 21
8.3 Alternative 2 21
8.4 Alternative 7 22
8.5 Alternative 8 23
8.6 Alternative 9 24
8.7 Alternative 10 24
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9.0 Summary of Comparative Analysis of Alternatives....25
10. 0 Selection of Remedy 27
11.0 Statutory Requirements 27
11.1 Protective of Human Health and the
Environment 27
11.2 Attainment of Applicable or Relevant
and Appropriate Requirements 27
11.2.1 Contaminant Specific ARARs 28
11.2.2 Location Specific ARARs 28
11.2.3 Action Specific ARARs 28
11.2.4 To Be Considered Criteria 29
11.2.5 ARAR Attainment 29
11.3 Cost Effectiveness 29
11.4 Utilization of Permanent solutions and
Alternative Treatment Technology or
Resource Recovery Technologies to the
Maximum Extent Practicable 30
11.5 Preference for Treatment as a
Principal Element 30
12 .0 Remedial Design 30
12 .1 Treatability Studies 30
12.2 Wetlands 31
12.3 Cleanup Goals 31
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LIST OF FIGURES
Figure 1.3 DOPC Surface Features
Figure 1.4 Oil Recovery System
Figure 4.2 Contaminants in Vault
Figure 5.5 Alternative 8
Table 4.6
Table 4.8
Table 1.2
Table 5.1
LIST OF TABLES
Contaminants in Vault
Contaminants in Vault
Potential Exposure Pathways
Table 1 PNAs List
Table 2.2 ARARs
Alternative Criteria Assessment
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Record Of Declaion
Dubose Oil Products Site
Cantonment, Florida
1.0 INTRODUCTION
The Dubose Oil Products Company Site (DOPC) was proposed for
inclusion on the National Priorities List (NPL) in 1984 and finalized
in June 1986. In 1985, the Florida Department of Environmental
Regulation (FDER) conducted an Emergency Removal at the site that
consisted of excavation and onsite containment in a vault of
contaminated soil and installation and maintenance of a leachate
treatment system for the vault. In 1987, FDER signed a Consent Order
(CO) for the performance of a Remedial Investigation and Feasibility
Study (RI/FS) with the potentially responsible parties (PRPs). The
RI report, which examines air, sediment, soil, surface water and
groundwater contamination was completed in April 1989. The FS
report, which develops and examines alternatives for remediation of
the site, was issued in draft form to the public on February 16,
1990.
2.0 SITE NAME. LOCATION. AND DESCRIPTION
The DOPC site occupies approximately 20 acres of land in Escambia
County, approximately two miles west of Cantonment, Florida (see
Figure 1.3). The land onsite slopes from an elevation of 165 feet
above mean sea level (msl) in the south to 80 feet above msl in the
north. A nearby stream, Jacks Branch, receives site runoff which is
conveyed to the Perdido River and subsequently to Perdido Bay.
The DOPC site is flanked by Highway 97 on the east and River Annex
Road on the west. Highway 97 extends in a northwest-southeast
direction and River Annex Road extends in a northeast-southwest
direction. These roads meet approximate three-quarters of a mile
north of the DOPC site. Access to the site is by private road
leading off Annie Bell Road.
The site consists of an open-sided barn, a soil containment vault, a
sump pond, three surface water ponds (designated as the Southwest
Sump, the Leachate Pond and North Pond), and an area where soil was
excavated (west and southwest of the barn) and placed in the
containment vault. Figure 1.2 depicts the features described above.
The containment vault is approximately 170 ft(l) x 170 ft(w) x 35 ft
(d) in size and holds roughly 38,000 cubic yards of soil. The barn,
used as the "process facility" during site operation, contains old
rusted tools, machine parts, old cans and several drums containing
unidentified waste material. This barn was formerly used for raising
hogs and was identified as the "hog barn" in previous investigation
reports; this Record of Decision (ROD) conforms to previous usage of
the name.
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DOPC SURFACE FEATURES
DUBOSE OIL PRODUCTS COMPANY SITE
SOUTHWEST,
SUMP
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-2-
2.1 AREA LAMP USE
The DOPC site is located in a rural setting. Land use is
predominately agricultural, although development of low density
housing is encroaching from the east. Residences in the area are
served by the Farm Hill Utility District, a community water supply.
Tree farms lie west of the site, while pasture land and undeveloped
forest areas lie south and north. Aerial photographs taken in 1980
indicate about 35 residences within 1/2 mile of the DOPC site.
Eleven residences are located within 1/4 mile of the center of the
vault; the nearest residence is approximately 540 feet south of the
center of the vault. The nearest community, Cantonment, a town of
about 3,500 people is about two miles east of the site. Land use in
Cantonment is mixed residential, commercial, and industrial.
2.2 SURFACE WATER
Surface water hydrologic features of the DOPC site and its
surroundings include natural drainage features and man-made drainage
alterations. The northern half of the DOPC site and the area just
north and west of the site are characterized by naturally occurring
steep grades which form streams that flow only during rainfall
periods; there is not continual surface water flow offsite. These
streams flow into Jacks Branch to the northwest. An intermittent
stream begins at the overflow weir of the North Pond and leads north
to Join a second intermittent stream formed by a drainage area to the
west. This combined (second-order) stream then flows to Jacks
Branch. The approximate distance that run-off must travel from the
DOPC site to Jacks Branch is 5,400 feet.
Previous studies cited a number of springs on the DOPC site. These
springs were reportedly located near the present Southwest Sump and
Leachate Pond area and southeast of the North Pond. During the early
phases of the RI, springs were present near the southwest corner of
the North Pond and in an area near the northeast corner of the North
Pond. During the summer of 1988 (a period of low rainfall), no
springs were observed on the site. Thus, spring flow onsite responds
to changes in precipitation and groundwater levels in the perched
water-table- aquifer.
Three man-aide ponds on site collect groundwater seepage and retard
overland run-off. These ponds were constructed by the site owner
without the benefit of engineering studies to capture seepage and to
"treat" leachate from the old South Pond. Water depths of the
Southwest Sump and Leachate Ponds are approximately 15.4 feet near
the southern end to 18.5 feet near the northern dike. These depths
were measured in late spring, 1988. The Southwest Sump drains to the
Leachate Pond through a small channel in the dike which separates the
ponds. The Southwest Sump and Leachate Pond are hydraulically
connected to the perched water-table aquifer through the pond
bottoms. The Leachate and North Ponds are not connected by a surface
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channel but are connected via seepage through the dike separating
ponds and the overflow pipes. The North Pond is eleven (11) feet
lower in elevation than the Leachate Pond, thus a strong hydraulic
gradient exists between the ponds. The North Pond was built on the
local clay unit and is recharged through lateral in-flows from the
Leachate Pond and the perched water-table. The estimated volume of
water contained in the North and Leachate Ponds and Southwest Sump is
8.1, 0.7, and 0.065 million gallons, respectively. The North Pond
water level is controlled by several overflow drain pipes located in
the pond and in the dike. Due to relatively constant groundwater
inflows, discharge from the North Pond occurred continuously through
out the period of RI studies.
2.3 GROUNDWATER
The DOPC site is located within a recharge area of the
sand-and-gravel aquifer (Trapp and Geiger, 1986). The
sand-and-gravel aquifer consists primarily of quartz sand that
contains much gravel-sized quartz and thin discontinuous lenses of
fine-grained sediments. Regionally, the aquifer is a wedge of
unconsolidated sediments that varies in thickness from a featheredge
in southern Alabama and Walton County, Florida, to more than 1,400
feet in southwestern Alabama (Miller, 1986). The aquifer sediments
are alluvial deposits ranging in age from Miocene to Recent (Fran1
1982). Trapp and Geiger (1986) report the aquifer is generally
unconfined, although in some areas clay-rich lenses within the wedye
of sediments produce confined conditions. The aquifer at the DOPC
site is unconfined to seasonally semi-confined by a thick clay layer
that is present at 55-105 feet above msl under most of the site. The
surficial sands locally contain a perched water-table that develops
as the downward progress of infiltrating precipitation is slowed by
the clay unit. Water levels within the perched water-table are
between 0-25 feet below land surface. Water levels in the regional
aquifer locally are at depths of 30-95 feet below land surface.
Seasonally, water levels in the regional aquifer extend into the base
of the clay unit, so that semi-confined conditions occur within the
deeper sand units.
The regional sand-and-gravel aquifer receives recharge at the DOPC
site by direct infiltration and by percolation of water through the
local confining clay unit. Consistent with the gradient reported in
the earlier studies (FDER, 1985), groundwater movement in the
regional aquifer in Fall 1988 was to the west in the vicinity of the
DOPC site. Gradients reported in earlier studies (FDER, 1985) were
low and RI studies confirm that local gradients remain low. Aquifer
testing indicated that the perched water-table and the regional
aquifer are poorly connected hydraulically. No water level declines
were noted in the perched water-table during aquifer testing of the
well in the regional sand-and-gravel aquifer.
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Groundwater in the perched water-table is recharged by infiltration
of precipitation and moves laterally to its place of discharge. The
water level contours of the perched water-table are a subdued replica
of local topographic contours. Previous studies indicated seepage
from the perched water-table discharged at land surface where the
Southwest Sump and Leachate Pond are currently located. Water level
contours and r&sults of RI test borings indicate the perched
water-table does not exist at elevations less than about 115 feet
above msl on the northern side of the DOPC site. The Leachate Pond
and the Southwest Sump are hydraulically connected with the perched
water-table. On its eastern side, the North Pond receives lateral
in-flow from the perched water-table, and seepage from the Leachate
Pond migrates through the dike to the North Pond. Thus, water from
the perched water-table aquifer beneath most of the site reaches the
North Pond before leaving the site.
3.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
The DOPC site was operated by Mr. Earl Dubose from January 1979 to
approximately November 1981 as a waste storage, treatment, recycling,
and disposal facility. Material was transported to the site in
trailers and drums and included waste oils, petroleum refining
wastes, wood-treatment wastes, paint wastes, spent solvents, and
spent iron/steel pickle liquors. Most of the waste handling occurred
in and on the north and west sides of "process facility" that was
formerly a hog barn.
Mr. Dubose acquired the site in late 1977 and reportedly made
modifications to the site before he started his operation. Early
operation of the facility (during 1979 and most of 1980) was
described in the July 1982 Dubose Site Closure Plan. According to
this report, "the facility utilized a batch thermal treatment process
to recover a usable oil product from waste oil, petroleum refining
wastes and oil-based waste solvents." Waste oils were transported to
the site by tanker trucks. Spent solvent and process wastes from
petroleum refining and wood treating operation arrived at the site in
55 gallon drums aboard flatbed trucks. These drums were unloaded and
the contents emptied into a tank transport vehicle. The emptying of
drum contents into the tank transport vehicle occurred somewhere
adjacent to the drum storage area. Empty drums were stored in the
drum storag* area.
Figure 1.4 depicts the treatment process as reported by Mr. Dubose in
his 1982 Site Closure Plan. Spent pickle liquor was shipped to the
site in aluminum tanker trucks and emptied into a treatment tank
(T-l) to begin a 12 hour steam heating period. Waste oils and
solvents were stored in Tank T-l after filtration for the purpose of
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SIMPLIFIED PROCESS FLOWCHART FOR OIL RECOVERY SYSTEM
Spent Pickle Liquor
\a a
Soda Ash (100-0)0 U.s./Batd>)
. Decontamination Residues to Landfill
*" (76 druns. 11-81)
Feed Water Tank
n
O
J
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removing solids. The pickle liquor acted as "a thermal medium and
mixing agent for the waste oils and solvents" (Environmental
Licensing Group, 1982). Soda ash was added during the last 30
minutes of the 12 hour heating cycle to neutralize the pickle
liquor. After heat treatment, the spent pickle liquor was stored in
Tank S-7 (see Figure 1.3) for subsequent offsite transport. "Usable
solvent blended fuel oil" from the heating process was stored in
Tanks S-l, S-2 and S-3. As noted in Figure 1.4, a second Tank (T-2)
was used for treatment of waste diesel fuel; the treatment system
consisted of rock salt filtration. "Product" recovered from this
process was stored in Tanks S-5 and S-6. Empty drums were either
sold to the Mitchell Steel Drum Company of Mobile, Alabama or
"crushed and stacked for possible resale as scrap metal." The 1982
Closure Plan also stated that Mr. Dubose had buried crushed drums in
the eroded area just west of the "facility equipment location."
Mr. Dubose had contracted with several companies in the Gulf Coast
area to receive, treat, and properly dispose of their wastes. In
September 1980, after over a year-and-a-half of operation, Mr. Dubose
applied to the EPA for a Resource Conservation and Recovery Act
(RCRA) Interim Status permit to operate a treatment, storage, and
disposal (TSD) facility at the site. Mr. Dubose continued to operate
the facility before receiving an approved permit and he did not
inform his clients that he was operating without a permit. In
November 1981 Mr. Dubose ceased operations and, late in the year,
began to dismantle his equipment and transport it to a similar
operation he was running called Recovery Systems in Biloxi,
Mississippi.
In March 1982, the FDER conducted an Interim Status Standard
Compliance Inspection at the site and found Mr. Dubose was preparing
to close the site without an approved closure plan. The FDER then
requested that the U.S. Environmental Protection Agency (EPA) sample
the site. During this activity, buried metal objects, contamination
of springs and leachate seeps, and an oil sheen on the North Pond
were noted. In July 1982, Mr. Dubose submitted a site closure plan
to the FDER. This plan did not meet FDER criteria and Mr. Dubose was
denied permission to close the site.
In late October 1982, Mr. Dubose informed the FDER that he was
excavating the buried drums found at the site, an action that
constituted an unapproved cleanup action. In May 1983, the FDER
filed a civil complaint against Mr. Dubose in the Circuit Court in
Escambia County. * The FDER alleged that actions by Mr. Dubose had
violated surface water quality criteria, posed a threat to local
groundwater supplies, violated the Florida Air and Water Pollution
Act by operating the facility without a permit, violated the Florida
Solid Waste Statute by burying drums without a permit, and posed an
imminent hazard and immediate danger to human health, safety,
welfare, and the environment.
In its complaint, the FDER requested the court issue a permanent
mandatory injunction requiring Mr. Dubose to perform all cleanup
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procedures starting with site investigation and ending with site
cleanup and long-term monitoring. In addition, the FDER requested
the Court to order Mr. Dubose to reimburse FDER for all expenses
incurred by FDER in connection with the site and to impose civil
penalties against Mr. Dubose for violation of applicable Florida
laws. FDER also asked the Court to retain jurisdiction over the suit
until all terms.of the court orders were in compliance.
During the period between the FDER-EPA site visit and the end of July
1983, Mr. Dubose altered many surface features at the site. In April
1982, the DOPC site north of the hog barn consisted of the former hog
pond area, contaminated leachate seeps and springs emanating from a
side slope north of the former hog pond, and the North Pond (which
was receiving discharge from the contaminated seeps and springs).
Sometime before October 1982, the north dike of the North Pond
failed, releasing contaminated water to the tributary of Jacks
Branch. By early October, Mr. Dubose had constructed a ditch to
collect contaminated water from the seeps on the hillside south of
the drained hog pond and the springs. This ditch traversed the site
in an east-west direction and discharged where the North Pond had
previously discharged. By July 1983, the north dike of the North
Pond had been repaired and a new southern dike had been constructed
that created the Leachate Pond. The Leachate Pond was constructed by
moving the northern edge of the former drainage ditch further north
and placing a dike across the ditch at the halfway point (near the
east edge of the drained hog pond). Mr. Dubose also buried at the
east end of the Leachate Pond a storage tank from the previous
operation. This tank was to serve as a sump for a system to pump
water from the Leachate Pond up to the drained hog pond. Mr. Dubose
then set up a homemade water treatment system to aerate the Leachate
Pond water. Mr. Dubose also attempted biological treatment of
Leachate Pond water by adding commercially available microbial
seed. At an undetermined later date, Mr. Dubose added a mechanical
aerator to the Leachate Pond.
In early August 1983, Mr. Dubose started operation of the aeration
treatment system; this system was responsible for the creation of the
South Pond. Mr. Dubose started this treatment system without
approval by the FDER and continued its operation into the fall of
1984. During the pond construction activities, Mr. Dubose used heavy
equipment to aove contaminated soil without FDER approval. Mr.
Dubose did not have permits to carry out these activities as required
by Florida lav. Consequently, on August 17, 1983, FDER filed a
motion for preliminary injunction prohibiting Mr. Dubose from
continuing activities at the site that constituted an environmental
hazard to the public health and safety and requiring Mr. Dubose to
allow FDER access to the property to locate buried drums and
contaminated soil and to assess immediate cleanup requirements. The
motion also required Mr. Dubose to submit to FDER, and upon approval
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of FDER, to implement, a plan for cleanup and removal of the drums
and contaminated soil.
On August 26, 1983, the court entered a consent order requiring Mr.
Dubose to immediately curtail the aeration system and other work at
the site and allowing FDER access to the site for inspection and
determining compliance with the order.
In September 1983, the court granted a preliminary injunction
requiring Mr. Dubose: to allow FDER to sample and analyze the air,
soils, groundwater, surface water, and sediments on the site; and to
carry out certain soil and water operations at the site; and to
control water run-off from the site; to submit to FDER, within 10
days of receiving the results of analysis of FDER's samples, a
detailed plan for removing all contaminated material from the site.
Mr. Dubose was then to begin soil removal within five days after
receipt of FDER approval of the submitted plan.
In October 1983, the FDER hired O.H. Materials Company (OHM) to
perform a contamination assessment that would identify areas of
significant contamination. OHM activities during this assessment
included geophysical surveys, monitoring well installation, test pit
excavations, surface soil sampling and analysis, groundwater and
surface water sampling and analysis, and air monitoring.
In late October 1983, Mr. Dubose removed approximately 100 drums from
the site in violation of the September court order. On
October 25, 1983, FDER filed a motion for contempt and for
supplementary injunctive relief, requesting that Mr. Dubose be held
in contempt of the court's September injunction for removing the
buried drums and for soil excavation at the site during which several
drums were punctured. FDER contended these acts not only violated
the court's order but could result in spread of the contamination and
could impair the validity of data being collected by the FDER
contractor. On November 4, 1983, the court granted FDER's motion for
contempt, specifically finding Mr. Dubose in violation of the
preliminary injunction but ruled that the violation was done in good
faith reliance on the advice of Mr. Dubose's counsel. When Mr.
Dubose failed to submit a proposal for removal of contaminated soils
and buried drums by March 5, 1984, as ordered, the FDER on March 8,
1984, pled with the court a second motion for contempt and
supplementary injunctive relief. FDER asked the court to authorize
FDER and itfl contractor to enter the site and remove contaminated
soils in the event Mr. Dubose failed or refused to do so. FDER
further requested that Mr. Dubose reimburse the State of Florida for
the costs of removal.
On November 2, 1984, the court entered a second consent agreement
requiring Mr. Dubose to excavate and to secure onsite the
contaminated soils and sediments. The order also required the study
of onsite treatment processes, and the removal by Mr. Dubose of other
contaminated soils, sludges, and sediments to an approved hazardous
-------
-8-
waste landfill if the contaminated soils, sludges, and sediments
could not be effectively treated at the site. From September through
November, 1984, the FDER installed additional monitoring wells and
conducted other onsite studies.
From November 1984 through May 1985 the FDER, assisted by Earl Dubose
and OHM, proceeded with an emergency response action at the site.
The FDER initially worked with Mr. Dubose on the excavation of
contaminated soils and drums. Mr. Dubose also provided labor and
equipment for beginning construction of the containment vault.
However, when it became apparent that Mr. Dubose's equipment would be
unable to complete the excavation work and his resources were
exhausted, FDER requested that OHM complete the emergency response
action necessary to secure the contaminated soils onsite. Meanwhile,
other responsible parties were sought to complete the site cleanup.
Several PRPs were subsequently identified and a PRP Steering
Committee was formed.
In 1986, the PRP Steering Committee engaged Geraghty & Miller, Inc.
(G & M) to prepare a work plan for conducting a RI/FS for the DOPC
site. The work plan was prepared (G & M, August, 1986), and was
reviewed and approved by the FDER (October, 1987).
On October 26, 1987, a Consent Agreement for proceeding with the
RI/FS was reached between the FDER and the PRPs. Engineering-Scie
(ES) was selected in December, 1987 by the PRPs and approved by FL
(January, 1988) to conduct the RI and FS work at the DOPC site.
The RI/FS was conducted in 1988 and 1989. The RI was submitted in
April 1989 and the final draft FS was submitted in January 1989.
4.0 COMMUNITY RELATIONS
The RI/FS and Proposed Plan for the DOPC were released to the public
in February 1990. These documents were made available to the public
in the administrative record and in information repositories
maintained at J. M. Tate High School and the Main Library at the
University of West Florida. The notice of availability was published
in the Pensacola News Journal. The public comment period was held
from February 16 to March 16, 1990. A public meeting was held on
February 27, 1990, to present the remedial alternatives for the
site. During the meeting, EPA, FDER, and representatives from
Engineering-Science (the RI/FS consultant) presented the results of
the RI/FS. FOER presented the Proposed Plan and answered questions
about problems at the site and the remedial alternatives under
consideration. A response to the comments received during the public
comment period is included in the Responsiveness Summary/ which is
part of this ROD. A transcript of the public meeting is available
for review in the repositories.
-------
-9-
5.0 SUMMARY OF SITE CHARACTERISTICS
The RI at the DOPC site was designed to determine the extent of
contamination at the site, to determine potential impacts of the
contaminants on human health and the environment, and to develop data
needed for an engineering evaluation of further remedial actions.
Earlier studies at the site had found onsite areas of soil, sediment,
and groundwater contamination. The RI expanded the search for
contaminants to offsite areas, and also re-examined areas previously
excavated and the vault to determine residual contaminant levels in
the soils. The RI was a comprehensive assessment of site conditions
that included additional characterization of site hydrogeology, new
site mapping by aerial and ground surveys, completion of additional
magnetometer surveys, air sampling and soil test borings, and
sampling of streams and wells offsite.
The investigation of the DOPC site was conducted during the period
from March 1988, through September 1988. A Work Plan for conducting
the site investigation (G & M, 1986) was provided to FDER by the PRPs
and incorporated into the Consent Order for conducting the RI/FS.
Stage 1 was conducted from March through July 1988, and consisted of
air sampling, soil and sediment sampling, surface water sampling,
test boring and monitoring well construction, groundwater sampling,
vault sampling, geophysical surveys, local well inventory, and site
surveys. Stage 2 work was conducted in September 1988, and consisted
of additional surface water, soil, sediment and groundwater sampling,
installation of piezometers and monitoring wells, aquifer testing and
site surveying necessary to refine the information obtained during
Stage 1. All analyses, except for field screening, were performed
using EPA Contract Laboratory Program (CLP) protocols. During the
period of June through October 1988, bench tests were conducted by ES
to evaluate the potential for biological treatment of the
contaminants in the vault soils. The results of the RI are presented
in the remainder of Section 5.
5.1 CONTAMINANT SOURCE INVESTIGATION
The contaminant source investigation was addressed according to the
Work Plan. Earlier studies indicated that soil excavations were
halted based on HNU readings, rather than on chemical tests. ES
conducted soil borings to determine residual contaminant levels in
soils in areas previously excavated and in potentially contaminated
areas surrounding the hog barn. Due to earlier reports of seeps and
springs of contaminated groundwater where the Southwest Sump and
Leachate Pond are situated, ES conducted borings into the pond
bottoms to determine residual contaminant levels in the sediments.
Because the majority of the contaminated soils were expected to
reside in the vault, ES sampled the soil containment vault during the
first stage activities. In addition, a magnetometer survey was
conducted to confirm that'all buried drums had be removed.
-------
-10-
ES completed 12 test borings into the containment vault (estimated to
be 40 feet deep) in order to characterize the soils inside. However,
as chere were no as-built drawings of the containment vault, it was.
decided that the boreholes would not extend below 35 feet. Extending
the boreholes any deeper risked breeching the integrity of the bottom
liner of the vault. The upper twenty feet of each boring was sampled
using a hand auger. The lower 15 feet were sampled using hollow-stem
auger drilling methods and split-spoon sampling techniques. A crane
was used to place a trailer-mounted hollow-stem auger rig on the
vault. Once on the vault, the rig moved from hole to hole with the
use of a winch. This movement caused a considerable amount of damage
to the vault cover, which was repaired once the drilling work was
concluded.
The principal contaminant source at the DOPC site is the soil
containment vault. in 1983, a site-wide geophysical survey was
conducted by Technos, Inc. that identified several areas where drums
were suspected to be buried. Data from the ES magnetometer survey
indicated that no buried tanks, drums, or other metal objects are
present in or around areas previously excavated.
The principal contaminants in the vault soils are Total Polynuclear
Aromatics (TPNAs), Phenols and volatile organic compounds. Analyses
of soil samples indicate contaminant concentrations increase with
depth in the vault (Figure 4.2 and Table 4.6). Both TPNA and
TPhenols concentrations increase from the top of the vault downwar
to the 25 to 30 foot depth level. The peak TPNA and TPhenols
concentration were 146,400 and 53,210 ug/kg, respectively for the
eastern vault samples; and 91,700 and 26,020 ug/kg for the western
vault samples. These values were found at depths ranging from 25 to
30 feet below the top of the vault. The compounds
benzo(g,h,i)perylene, acenaphthalene, and ideno(1,2,3-cd)pyrene were
the only compounds detected in samples recovered from the upper 15
feet of the vault.
\
The analytical results indicate that no one compound predominated
over the other PNAs. In contrast, pentachlorophenol, phenol, and
4-methylphenol are predominant among the TPhenols group.
Pentachlorophenol is the most common phenolic, with concentrations
ranging froa 58 ug/kg at the 5 foot depth (5E) 51,000 ug/kg at a
depth of 27 feet (27E). Phenol was detected in six samples from the
east and w»«t side of the vault, primarily in the 20 foot to 30 foot
zone. Phenol concentrations ranged from 210 ug/kg (20E) to 3,2000
ug/kg (10W). The' compound 4-Methylphenol was detected in more
samples than phenol/ but at concentrations half that of phenol.
A few other semi-volatile organic compounds were detected in the
vault. Following the pattern of PNAs and Phenols, dibenzofuran
increases in concentration with depth; peak concentration occurs in
the interval of 25 to 27 feet (6,000 ug/kg). Three phthalates,
bis(2-ethylhexyl)phthalate, butylbenzyphthalate, and
-------
VERTICAL DISTRIBUTION OF SEMI-VOLATILE
CONTAMINANTS IN THE VAULT
DUBOSE OIL PRODUCTS COMPANY SITE
CONCENTRATION IN PPB
100 1000 10000 100000
WEST
CONCENTRATION IN PPB
1 10 100 1000 10000 100000
i i umrf 11 nui4 i i inuJ i 11 nut i i tiiuf i
1Ph«nola
EAST
-------
TAHIK4.4
SUMMARY OF SKMI-VOlATIl.t: ORGANIC
( OMI'OUNDS IkKTMTKI) IN VAULT SAMPI.KS
millOSK Oil. PKOmUTS COMPANY SITK
( 'tnn|Hisili; DfjMh (Dc|ilh liclow lii|
%
1 .!!£» | < il«»U|»
l'H
Aiom.ilKs O7HJ)
liiljl I'lii- lit ils ****
(MU)
IUE I2I£ iSt
Nl) fc^Sl 3»S1
(I47U) (IhHSi)
Nl) Nl) ND
(UMU)
201
2l>IHIk
(I2MU)
IIMI
(IHlU)
2si-: 27I-: sw
SS»7« |46«K» Nl)
(4*>7Ui) (I4IUIJ)
I'MHII S12IU Nl)
(22IIUI
. ..(v.iull)1
IOW ISW 20W 25W MIW
4(HNI HS69 2H24U 9I70U (il)S4l
(IIIVJ) (2S40J) (6UU) (I'HJ)
I71MIU 140 1400 IIS7U 2d020
(I4IHU) (24HU) (2HOJ)
ius+ *>u/*
I TV i W
is- vv
7HOIO ISHTJ
(2MU) (HSU)
6MHt 41(1
(4lttl>
I I is tuNl h*M «>l v-ull anJ W is west lull «l vault
• I In M: 41 c tltMicIc samples
IX < 'iMnmwnil c«Mrcnli«lMMi cwccJctl the calihfMmtn langc. V^luc in«lii4lcs Ihc cumulative itMucnHjlum of ctMnptMintls thai citcctktl the
Nl) None tktcitcJ
J liiJii jtcs cdimatcU value. Value in |iaitnlbcui ic|MCM:nls estimated |>ail .4 laigci jy«Hi|)
nnlI I
-------
-11-
di-n-butylphthalate were detected in the vault samples. Only
bis(2-ethylhexyl)phthalate concentrations show increases with depth
similar to PNAs and Phenols. The soil composite sample from the 10
foot depth on the western half of the vault (10 W) contained
compounds not found in other vault samples, including
1,4-dichlorobenzene (59 ug/kg), 4-nitrophenol (3,100 ug/kg),
2-chlorophenol (3,600 ug/kg), and 4-chlcro-3methylphenol (3,700
ug/kg) . Other "compounds detected in discrete samples include
1,4-dichlorobenzene in sample 1W35 (59 ug/kg), benzo(g,h,i)perylene
in sample 30W, and ideno(1,2,3-cd)pyrene in sample 5E (41 ug/kg) and
sample 1W35 (130 ug/kg).
Discrete soil samples from the vault were analyzed for volatile
organics because compositing can result in losses of the compounds to
the atmosphere. The samples analyzed represent the most contaminated
depth interval encountered in each borehole, as determined by field
OVA screening. The principal TVA compounds in the vault were
xylenes, toluene, ethylbenzene; low levels of benzene and
chlorobenzene were detected in a few samples. Table 4.8 lists TVAs
and THNAVs levels in the vault samples. The depth intervals and
elevation values listed in Table 4.8 were calculated to identify
zones of contamination in relation to a common datum. The top of the
vault is not horizontal, thus, sample depths were adjusted for
differences in borehole elevations.
5.2 ONSITE SOILS AND VADOSE ZONE
The soils and vadose zone investigation at the DOPC site was
conducted over the whole site per the Work Plan, including areas of
concern identified by earlier studies. Shallow soil borings were
made over a wide area west of the hog barn and vault, south of the
hog barn, beneath the concrete floor of the hog barn, along the berms
surrounding the vault, and north of the North Pond. Previous studies
had indicated these were areas of potential soil contamination. The
areas were subdivided into numbered square or rectangular
subsections. Hereafter, these numbered sampling zones are referenced
by grid numbers. In accordance with the Work Plan , soil samples
from the screened intervals of monitoring wells were analyzed if
field screening indicated the soils were highly contaminated.
Polynuclear aromatic compounds constitute the majority of
contamination with G20-SS5 soil containing the highest concentration
(367,600 ug/kg). TCE was also detected at G20-SS5 at concentrations
ranging from 20 to 210 ug/kg over an eight foot depth. Soils in
berms around the vault appear to be contaminated at depths below four
feet while other areas have contaminants closer to the ground
surface. Pentachlorophenol was detected in all six areas ranging
form 130 (North Berm) to 5,500 ug/kg (G9-SS5).
-------
TAIUK48
SlIMMAKY OK VOIATILK ORGANIC COMPOUNDS
IMCTKCTKI) IN SOILS FROM Till*. VAULT
IIUIIOSK OIL I'ROIMUTS COMI'ANY SHI
SAMI'lliUH ATION
1)1 fill AND TAKif IKKtfo ?£ ?**
'(trial Vt4alilc Aiomaltcs NS
NIHI Autmalic Vtilalilcs NS
Ik'valitMt **
Sa.miil<; IH'iHh 2^ 27
'l.rial Vtdalilc Aftimaliu, NS
1 trial llalii^cnalcd
Nun Aiomatic Vt4alilcs NS
1 Icvalion **
s.tm|kit; IHpih 27-2V
'1 trial V«4alik Aiu«alic& 22.StHI
(30UJ)
|ND|
'I'trial llakigcoaled
Non AitimalK ViAalUcs ND
l-W-vali..- »MM
21: '31:
NS NS
NS NS
2.613 NS
(Hi)
|22|
Nl) NS
133 IIS
NS NS
NS NS
41: SI- (,K IW
NS NS NS NS
NS NS NS NS
NS NS 6.|
NS NS Nl) NS Kill
131 1)3 III Ml
NS
Sample depths have been adjusted fu* difltitntes in I
Heel aU»ve me a* sea level
(•untcnlf alion
-------
ix riu ANi>TAK<;i-T Aiomalic Volatile*
rievalion *•
Sample Ikpth y> 31*
1NTINIIKI»
SUMMARY 01 VOIATII K <)K<;ANI( (OMHUINDS
hHKrri i> IN SOILS KKOM TIIK VAULT
IHIItOSK OIL ^KOIUKTS COMPANY SHI
II:
NS
SAMI'I I-LOCATION
"ill 4K
51:
IW 2W
NS
.Ml W.27II NS
(41) |NI)|
NS NS NS NS
IW 4W SW 6W
NS
NS NS
NS NS Nl) H70I NS NS NS NS NS NS NS NS
I JO 112 IW 112
NS 2.041 NS NS NS NS NS NS NS NS H.IIMI NS
<2J)
NS HI NS NS NS NS NS NS NS NS Nl) NS
1 1
NS
J
Nl >
Sample (kpths have bcc* adiu&lctl fur differences in iMwcholc elcv
l-'cel above mew tea level
C (Mucnlf alMM of beazcoe deleclcJ
NtH uuaplcJ
InJicalcs cslimaied value. Value in paicnlhcMS icprc&cnls estimated pail of Urgcl gfoup
None delected
-------
TAIU.K 4.8 «:ONTINIIKI»
SUMMARY OF VOIATII Ji ORGANIC COMPOUNDS
IH IXTI l> IN SOILS FROM THK VAULT
inmost: on, r HO wins COMPANY SIIK
SAMI'l.li (.(RATION "
1)1 ITU AND TAKiiirrtiROUr l£ 2K ,- 31- 41- SII r»E |W 2W 3W
Sample Iknlli 31 31
1.4*1 VolaldcAuiMalics NS NS NS NS NS NS NS NS NS
'
Tidal llaki^cnalcd
Nun Aromatic VolalUcs NS NS NS NS NS NS .NS NS NS
IkvaUtM,-
I. .lal Volatile Aiomalitt NS NS NS NS NS NS 170 272 NS
Ilkil k| IK1I \l
ipii'i l^*"!
Iit4al Il4l«i^cn«ilttl
N,.n A,,miahi V,4aUlcs NS NS NS NS NS NS NO ND NS
1 Icvaliun •• IM >25
* Sampk dcpttu kave been adjiuled f«n differences in bof cb*4c clcvali N«me delected
NS N«i4 sampkd
4W 5W bW
NS NS Ml
|ND|
NS NS 7
127 I21)
NS NS NS
NS NS NS
-------
-12-
5.3 GRQUNDWATER
During the RI, ES installed 12 wells in the perched water-table and
seven wells in the regional sand-and-gravel aquifer. Water samples
from the shallow and deep wells installed during the first stage were
analyzed for the full Target Compound List (TCL). Samples from wells
installed during the second stage were analyzed only for organic
compounds. In addition to sampling the shallow wells installed
during the second stage, the deep wells installed during the first
stage were resampled to confirm the absence of contamination in the
regional aquifer.
Water in the perched water-table aquifer contains volatile organic
compounds (33 to 175 ug/1), as detected in three onsite wells (MW1S,
MW9S, MW14S). Among these were 1,1-Dichloroethene (1,1-DCE) at 15
ug/1 (MW14S) and 25 ug/1. MW14S also contained 11-14 ug/1 of
semi-volatile compounds. The regional aquifer is the source of local
water supplies. Trace amounts of organics were detected in three of
14 wells around the site that are completed in the regional
water-table aquifer. The amounts detected were below drinking water
standards, and one result was not confirmed by a subsequent sampling
round.
5.4 SURFACE WATER AND SEDIMENT
Surface water samples were obtained from the three ponds onsite and
from streams offsite. Earlier studies had identified contaminants in
ponds onsite, but had not sampled surface waters offsite. The stream
sampling points were located 1,250 feet north of the site and in an
unnamed stream with similar characteristics in an adjacent drainage
basin west of the DOPC site. The locations of the surface water
sampling sites are shown on Figure 2.3. Sampling of the streams was
conducted by obtaining a grab sample just below the water surface at
each sampling point. Sampling of the ponds at various depths was
accomplished with the use of a Kemmerer sampler. All sampling
equipment was decontaminated prior to each use.
Sediment samples were collected from the upper 3 inches and lower 1
foot of the sediments present in the North Pond, Leachate Pond and
Southwest Snip. Because earlier studies reported a breaching of the
North Pond, the sediments of the tributary to Jack's Branch were
sampled. Tte sediment samples were collected at the same sampling
stations where surface waters were collected.
Surface waters of the DOPC site are free of contaminants with the
exception of the Southwest Sump and Leachate Ponds, where up to
97 ug/1 of contaminants were detected. The Southwest Sump contained
-------
-13-
17 ug/1 Trichloroethane (TCE) and 4 ug/1 1,1-Dichloroethene (DCE).
First and second stage sampling determined that the northern
two-thirds of the North Pond's sediments contain polynuclear
aromatics and pentachlorophenol up to 2,268 ug/kg and 560 ug/kg,
respectively. Testing showed that contamination is restricted to the
upper 6 feet of pond sediments. This is in contrast with the
Leachate Pond, vhere volatile aromatics (3 to 180 ug/kg), polynuclear
aromatics (68 to 8,503 ug/kg) and phenols (99 to 660 ug/kg) were
detected to a depth of 8 feet below the pond bottom. Samples from
the Southwest Sump were free of contaminants at depths greater than 1
foot below the pond bottom. The upper 1 foot of sediments contains
roughly 16,800 and 850 ug/kg of polynuclear aromatics and
pentachlorophenol, respectively. The sediments in a tributary to
Jacks Branch, immediately north of the North Pond, had much lower but
detectable levels of contaminants to a depth of 1.7 feet.
5.5 AIR INVESTIGATION
Air sampling for semi-volatile organic compounds and total suspended
particulates was performed in accordance with the Work Plan for the
purpose of acquiring background data. This was necessary to measure
the level of fugitive emissions from the site prior to the
commencement of remedial actions, thus determining the level of
protection necessary for the workers on the site and to evaluate
potential impact on the public downwind of the site.
The results of the air investigation indicate that the air pathway
would not be of concern.
5.6 BIO-TREATABILITY STUDY
In accordance with the Work Plan, bench-scale treatability studies
were performed at the BS laboratory in Atlanta to assess the
potential of biological methods to remediate the site. The primary
objectives of the bench tests were as follows:
* To determine if the wastes could be stabilized onsite by
biological transformation and mineralization.
" To determine the extent to which biological treatment could
be used to remediate the site and to assess the fate of
waste constituents present at the site.
To achieve these RI objectives, four separate treatability studies
were performed:
1. In-Situ Column Experiment - This study was designed to
evaluate the feasibility of in-situ degradation in the
vault. Leachate recirculation and side stream biological
treatment were tested to assess their relative merits.
-------
-14-
Mineral salts were added to the leachate to ensure that
organic material in the soil column was growth limiting and
nitrate was supplemented in one set of columns to support
anoxic growth.
2. Anaerobic/Anoxic Serum Bottle Experiments - The purpose of
these experiments was to assess anaerobic/anoxic bioactivity
in the contaminated soils by direct measurement of gas
production over time.
3. Biometer Experiments - The purpose of these tests was to
evaluate aerobic biological activity within soils by direct
measurement of oxygen consumption over time.
4. Mesocosm Experiments - Mesocosm experiments were conducted
to assess the biological treatability of the contaminated
soils using landfarming and composting technologies. The
effects of different waste loading rates on constituent
removal was also examined.
Preliminary results from the treatability studies suggest that
semi-volatile compounds in the vault soils can be degraded
aerobically. Seeding of the contaminated soils with aerobic bacteria
appears to speed up biodegradation. Pentachlorophenol appears
somewhat resistant to biodegradation and leaching, and may be the
most persistent contaminant onsite. Studies indicate years to
decades may be required to biodegrade high levels of
pentachlorophenol in soils and sediments. Anaerobic treatability
experiments indicated that degradation in the saturated zone of the
vault is likely to occur slowly, if at all, under current
conditions. For biodegradation to be a successful remediation
technique at the site, it is likely that nutrients and oxygen will
have to be added to the soils. Of the volatile compounds in the
vault, only chlorobenzene is considered somewhat resistant to
biological attack.
5.7 CONTAMINANT PATE AND TRANSPORT
All of the results of the RI site investigation demonstrate that
offsite migration of contaminants in air, surface and groundwater is
not occurring, but that the potential exists for leaking of volatile
and phenolic contaminants out of the vault and into the perched
water-table. These contaminants would then be transported to onsite
ponds and to the tributary of Jacks Branch. Volatile compounds are
not expected to remain in surface waters as they will volatilize and
eventually be photo-oxidized in the atmosphere. This is confirmed by
the fact that low levels of volatile organics were detected in two
wells in the perched water-table, yet no volatile organics were
detected in samples from the North Pond and Jacks Branch. At
present, migration of semi-volatile organic contaminants from pond
-------
-15-
sediments to surface water is not evident. Phenolic compounds,
except pentachlorophenol, potentially could reach Jacks Branch after
leaching from vault berm soils or in leachate escaping the vault
because these compounds are moderately soluble, have low sorptivity,
and are slow to volatilize.
The semi-volatile compounds and pentachlorophenol detected at the
DOPC site adsorb strongly to soil and thus migration of these
contaminants is a function of sediment transport. Overland migration
of sediments and soils during rainfall events or via North Pond
discharges could occur. Pond sediments could be resuspended and
discharged from the North Pond during windy conditions (i.e.,
churning of bottom sediments) or heavy rainfall events. Washoff of
contaminated soil near the hog barn and vault could also occur during
heavy rains.
Preliminary results from treatability studies suggest that
semi-volatile compounds in the vault soils can be biologically
degraded under aerobic conditions. Seeding of the contaminated soils
in the vault is likely to occur slowly under current conditions. For
biodegradation to be a successful remediation technique at the site,
nutrients and oxygen will have to be added to the soils.
6.0 SUMMARY OF SITE RISKS
6.1 SELECTION OF INDICATOR CHEMICALS
The RI report contains results of a baseline public health evaluation
of the OOPC site that was conducted per USEPA methods (Superfund
Public Health Evaluation Manual, 1986). Based on concentration,
pervasiveness, toxicity, and persistence; the following compounds
were chosen as indicator chemicals: polynuclear aromatic
hydrocarbons (TPNAs), bis(2-ethylhexyl)phthalate, xylenes,
1,1,1-trichloroehane, 1,2-dichloroethene, and pentachlorophenol.
Both maximum (28 ug/1) and best estimate (12.75 ug/1) concentrations
of 1,1,1-trichloroethane (TCA) detected in the surface water samples
from the Leachate Pond and Southwest Sump do not exceed the MCL and
Florida Groundvater Primary Standard of 200 ug/1. Therefore, no risk
computation* were required for TCA. The Risk Assessment performed
for the RI was very conservative for evaluating risk from human
exposure to TPNAs. All TPNAs were assumed to have the same
carcinogenic risk as benzo(a)pyrene (BAP)/ even though some TPNAs are
not believed to be as potent as BAP, nor even to be carcinogenic. In
order to evaluate effectiveness of remedial alternatives to protect
public health, the risk assessment for this FS was conducted by
separating the TPNAs into carcinogenic and noncarcinogenic groups.
Likewise, more detailed risk evaluation of the remedial alternatives
was performed using oral exposure values to estimate dermal
exposures, and 1,1-DCE was used to estimate toxic effects of the
dichloroethene isomers.
-------
-16-
6.2 EXPOSURE ASSESSMENT SUMMARY
The following complete pathways of exposure (Table 1.2) were
identified for the baseline risk assessment: dermal exposure to
soils onsite, dermal exposure to surface water onsite, dermal
exposure to sediments in the tributary to Jacks Branch, ingestion of
soils onsite, ingestion of surface water onsite and ingestion of
sediments in the tributary to Jacks Branch. Potential receptors for
these six pathways are children aged 3 to 12, both as trespassers and
family members residing near the site. An exposure pathway through
groundwater might exist in the event that no remediation occurs, the
vault liner fails, and the site is developed for residences that do
not utilize public water supplies. There is also a very long-term
possibility that without remediation, contaminants might migrate
offsite and emerge from groundwater into the tributary to Jacks
Branch. These pathways were not considered complete during the RI
because there were not potential receptors to the low levels of
contaminants detected in groundwater onsite and no contaminants were
detected in surface water offsite.
6.3 TQXICITY ASSESSMENT
For purposes of public health evaluation, USEPA (1986) uses three
values with which to characterize the toxicity of a given compound.
These include:
0 The Reference Dose for chronic exposure (RFD)
8 The acceptable intake for subchronic exposure (AIS)
0 The carcinogenic potency factor
The RFD for a compound is ideally based on study of chronic effects
where the test animal or human population was exposed to the compound
of interest over a major portion of total lifespan. The AIS is
ideally based on studies involving subchronic exposure, i.e.,
exposure for approximately 10 percent of the lifespan.
If animal studies are used as the basis for an AIS and RFD, a
No-Effect-Lsjrel (NOEL), No-Observed-Adverse-Effect-Level (NOAEL) or
Lowest-Observed-Adverse-Effect-Level (LOAEL) is determined from the
most appropriate.study, and is subsequently divided by a series of
uncertainty factors to arrive at an AIS or RFD for humans. The
uncertainty factors correct for possible unknown effects associated
with extrapolation of data for animals to human, effects of
especially sensitive subgroups within a population, using a LOAEL to
approximate a NOAEL when the NOEL or NOAEL was not determined, and
for using subchronic data to estimate chronic exposure effects.
Carcinogenic potency factors are derived only for compounds which
have been shown to cause an increased incidence of tumors in either
-------
MATKIX 01-
TABI.K 1.2
I'OTKNTUI. KXPOSUKK PATHWAYS
—~^. 4v\Mi»ANV SITE
S...I
-------
IAHI K 1.2 (CONTINUUM
MA IK IX OK POTENTIAL EXPOS1IKK PATHWAYS
IHIHOSK Oil. PRODUCTS COMPANY SITE
McJuMH
HckMsSMM/
fiMMfy lufHuuic
fnmiry
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tcakd, IIOMVCI •Muni clcmcnu ami
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Muiknlc. MMimlm rkcntir*lk vcn
4ticnod Mrt ike MIC Juc4 MM tovc wxcu
ICMIWIUMU
-------
-17-
human or animal studies. The potency factor is an upper 95 percent
confidence limit on lifetime risk and is determined by low-dose
extrapolation modeling of human or animal data. When an animal study
is used, the final potency factor is adjusted to account for
extrapolation of animal data to humans. If the studies used to drive
the potency factor were conducted for less than the lifespan of the
animal (or human), the final potency factor is adjusted to reflect
risk associated with lifetime exposure.
Subchronic exposure was not considered in this evaluation since the
primary concern is potential lifetime risk. Therefore only RFDs and
carcinogenic potency factors were used in the following evaluation.
Available RFD values and carcinogenic potency factors for the
indicator chemicals are presented in Table 6.18. For oral exposure,
either a potency factor or an RFD is available for most of the
indicator chemicals. However, PCP had no carcinogenic potency
factor, therefore, carcinogenic risks associated with potential
exposures at the DOPC site could not be quantified. However, the
risks for short and long-term exposure to PCP for each alternative
was developed in the FS using the not yet officially proposed
carcinogenic potency factor of 1 x 10 . Those risk ranges fell
within Agency guidelines of 1 x 10~* to 1 x 10~6 acceptable risk
range.
For dermal exposure, RFDs and carcinogenic potency factors for many
compounds have not been derived.
6.4 POTENTIAL CARCINOGENIC AND NONCARCINOGENIC CONTAMINANTS
6.4.1 NONCARCINOGENS
Exposure point concentrations were determined for each medium and
compared with ARARss Maximum Contaminant Levels (MCLs), Maximum
Contaminant Level Goal (MCLGs), Water Quality Criteria, and Florida
Groundwater Quality Standards. Chronic Daily Intake (CDI) values by
oral and dermal routes were calculated in the RI for each indicator
chemical. No baseline risk assessment was made in the RI for
exposure to the soils in the containment vault because access by
children is temporarily prevented by the PVC cover. The
route-specific GDIs were compared with toxicity values which have
been derived by USEPA. Carcinogenic and nonearcinogenic effects were
considered separately. For non-carcinogenic compounds,
route-specific GDIs were compared with reference doses (RfDs).
Ratios of CDI to RfD were summed across chemicals and routes of
exposure to yield a hazard index. A hazard index of less than one
indicates that no risk is likely to be incurred by a receptor.
Hazard indices for children aged 3 to 12 were computed to range from
0.0001 to 0.0003. These indices are based solely on oral exposure,
since RfD values do not exist for dermal exposure. Nonetheless, the
indices suggest that potential health hazards associated with
non-carcinogenic indicator chemicals at the DOPC site are unlikely to
exist for children age 3 to 12 under current conditions.
-------
TABLE 6.18
CRITICAL TOHCITY VALUES(l)
DUBOSE OIL PRODUCTS COMPANY SITE
Indicator Chemical
Polynuclear Aromatic Hydrocarbons
bis (2-EthyLhexyl) Phthaiate(4)
Xylenes(4)
1, 1, l-Trichioroethane(4)
1,2-Dichloroethene (4)
Pemachlorophenol (4)
CAG
Group (2)
B2
B2
D
D
D
D(3)
Reference Dose
Oral
(mg/kg/day)
none
2E-02
2
9E-02
2E-02
3E-02
Carcinogenic
Potency Factor
Oral
(mg/kg/day)'1
USE H- 01(5)
1.4E - 02
none
none
none
none(3)
(1) Source of Data is U.S. EPA, 1986, unless otherwise referenced.
(2) CAG - U.S. EPA Carcinogen Assessment Group;
CAG Groups are assigned as follows:
A known human carcinogen
Bl, B2 probable human carcinogens
C limited evidence of carcinogenicity
D insufficient evidence of carcinogenicity
E evidence which supports lack of carcinogenicity
(3) Note • Since this report was written, pentachlorophenol has been «"-i««"fi»j< as a B2 carcinogen,
however an MCL has not been proposed nor has a Carcinogenic Potency Factor been
established.
(4) Source of Data is IRIS Database: on-line review November 14,1988.
(5) Benzo(a)pyrene value used for CPF since it is the most potent of the PAHs.
881U30
6-30
-------
-18-
6.4.1 QARCINOGEN^
For carcinogenic compounds, GDIs were multiplied by potency factors
to obtain the risk of developing cancer from daily exposure over a
period of 70 years. The ES approach to computing cancer risk in the
RI was conservative for two reasons: (1) some TPNA compounds are not
carcinogenic, and (2) the potency factor for the entire group is
estimated from the potency factor of the group's most carcinogenic
compound [benzo(a)pyrene]. Since route-specific GDIs were available
only for oral exposure, and since USEPA has not derived potency
factors for dermal exposure, risks were calculated only for oral
exposure. The risks associated with oral exposure for each indicator
chemical were then summed to yield an overall total risk for each
receptor. Based on the available data, best and maximum estimates of
baseline risk are respectively, 1.03 and 5.65 cancers per one million
persons exposed during their childhood. In other words, the risks of
such children developing cancer over a lifetime of 70 years range
from 1 cancer in 1 million to 6 cancers in 1 million individuals.
These risks are acceptable under current USEPA guidelines (1 in
10,000 to 1 in 10 million cancers).
6.4.3 ENVIRONMENTAL RISKS
Risks to the environment were not quantified; however, according t-
U.S. Department Of Interior (U.S. DOI), there are no significant
natural resources near the site. Several species "of concern" liv<=«
in the general area of DOPC; none have been identified on the site
proper. Based on the analysis of the fate and transport of
contaminants, it does not appear as if any of the contaminants are
migrating off-site and, thus, onsite contaminants should not pose a
threat to the environment.
\
7.0 REMEDIAL ACTION OBJECTIVES AND GENERAL RESPONSE ACTIONS
7.1 SITE REMEDIAL ACTION OBJECTIVES
The RI at the DOPC site indicated that the regional aquifer beneath
the site contained extremely low to undetectable levels of
contaminants below drinking water standards. The perched
water-table, Leachate Pond, and Southwest Sump contain trace
quantities of contaminants, and the levels of TCE and DCE were
detected above surface and groundwater ARARs. Because these small
ponds and the perched water-table discharge directly into the North
Pond, cleanup objectives for site waters are developed for the North
Pond discharge. The point where water exits the North Pond discharge
pipe is considered to be "offsite" and is the point where water ARARs
apply. During remedial action, monitoring of discharge from the
North Pond is necessary to assure ARARs are not exceeded. After
remedial action is complete, groundwater monitoring will be
necessary. Also, deed restrictions should be implemented
-------
-19-
to preclude use of the perched water-table beneath the site as a
water supply. The RI study found higher contaminant levels in the
vault and in soils and sediments from isolated areas onsite.
Preliminary cleanup goals for the DOPC site will address TPNAs,
pentachlorophenol, xylene, TCE, DCE, and benzene levels in the North
Pond discharge water and the soil and sediment media.
7.2 WATER
Preliminary cleanup goals for the North Pond discharge water are as
follows:
TPNAs 10 ug/1
Pentachlorophenol 30 ug/1
Xylenes 50 ug/1
Benzene 1 ug/1
Trichloroethene (TCE) 3 ug/1
1,1-Dichloroethene (DCE) 7 ug/1
A list of individual PNAs is found in Table 1. The values for
pentachlorophenol, benzene, TCE and OCE are based on the lower of
federal and state ARARs listed in Table 2.2. The value for xylene is
a Florida groundwater quality standard. The value for TPNAs is
tentatively set at the currently achievable detection limit for TPNAs
in water according to USEPA Method 8270. Although the ARAR for TPNAs
is 2.8 nanograms/1, Section 121 d(4)(c) of SARA allows remedial
action levels greater than ARAR levels if compliance with such ARARs
is not technically possible at this time. The preliminary goal for
TPNAs may be lowered as future techniques allow lower detection
limits to be reached.
7.3 SOILS
Preliminary soil cleanup goals or action levels at the DOPC site will
be:
TPNAa 50 mg/kg
Pentachlorophenol (PCP) 50 mg/kg
Xylene* 1.5 mg/kg
Benzene 10 mg/kg
Trichloroethene (TCE) 0.050 mg/kg
1,1-Dichloroethene (DCE) 0.070 mg/kg
The cleanup goals for TCE, DCE, TPNAs, and xylenes are based
primarily on potential leaching of these materials from soils into
the perched water-table and migrating to the North Pond. The cleanup
goals for PCP and benzene are based on health based criteria that are
protective of human health. These cleanup goals will also prevent
leaching into the groundvater.
-------
TABLE 1
Acenapthene
Acenapthylene
Anthracene
Benzo(a)Anthracene
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Benzo(g, h, i)Perylene
Benzo(k)Fluoranthene
Chrysene
Fluoranthene
Fluorene
Indeno(1,2,3-cd)Pyrene
Naphthalene
Phenanthrene
Pyrene
2-Methylnaphthalene
-------
liulit .ilor ( hciitit .il
i AIIII: 2.2
AITI.U Alll I OK KH I VAN I AND AITKOI'KIATK Kl QIUKI Ml NTS STANDARDS AND
< KIT! KIA I OK < ONTAMINANTS Ol < ON< I KN
7 DIHIOSI OIL PRODUCTS COMPANY SI II
I'lOpOSt'd
M(K,
Sale l>iinkiiu>
W.IUM A»l"'
Mil.
MUii
Wiilcr (Ju.ililv ( liu-fia'2 *'
I >i inking Wiiu-r Di inking Water
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I.I I >it liloiiH llu in
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111 Soui.e 411 UK 141. last amendment 521 R2S7I2. Inly K, I'er I'fttS. On May 22, I'W), the HSI-il'A requesled tomntenls (led Reg., Vol. S4, No 97) on a M( I (. of /no I
of llu- reflassiftralion of PIT as a Class-02 careinogen. Tin- USl-l'A also icqiiesU-d toiiiiiienls on the feasibility of a Mt'l ol II.I M^/|. wliuli IN llu: |>i.itiual
lion limit for Pi'P.
-------
-20-
8.0 DESCRIPTION QP 1T.TERNATIVES
8.1 Q\
In the FS, a number of steps were performed to evaluate thoroughly
the potential remedial action alternative for the DOPC site. These
steps were: (1) formulation of site remedial action objectives, (2)
identification of general response actions, (3) identification and
screening of technologies, (4) development and screening of remedial
action alternatives, and (5) detailed analysis of alternatives.
Alternatives developed and screened included the following:
Alternative 1 -
Alternative 2 -
Alternative 3 -
Alternative 4 -
Alternative 5 -
Alternative 6 -
Alternative 7 -
N\
Alternative 8 -
Alternative 9 -
Alternative 10 -
No action, but long-term water monitoring.
Site regrading, capping and long-term water
monitoring.
Offsite landfill, site regrading and
topsoil cover.
Onsite landfill, site regrading, leachate
treatment, and long-term water monitoring.
Pozzolanic treatment, site regrading,
topsoil cover, and long-term water
monitoring.
Soil washing, wastewater treatment, site
regrading, topsoil cover, and short-term
water monitoring.
In situ biological treatment, wastewater
treatment, site regrading, topsoil cover,
and short-term water monitoring.
Composting/windrowing, wastewater
treatment, site regrading, topsoil cover,
and short-term water monitoring.
Combination of Alternatives 7 and 8.
Onsite incineration, site regrading, and
topsoil cover.
One common component of all 10 alternatives are deed restrictions to
prevent future exposures due to improper site development.
Alternatives 2, 7, 8, 9, and 10 were retained for detailed analysis
because they were determined to be protective of human health and the
environment and cost-effective. Alternatives 3, 4, 5 and 6 were not
retained because they provided the same level of protection that the
retained alternatives did. at a greater cost. Alternative 1 was
retained as a baseline case in the detailed analysis.
-------
-21-
The remainder of Section 8.0 will focus on the alternatives retained
for detailed analysis. A detailed evaluation of the risks associated
with each alternative can be found in Appendix B of this ROD. The
numbering scheme will remain the same to maintain consistency with
the FS.
8.2 ALTERNATIVE 1 - NO ACTION. BUT LONG-TERM MONITORING
Maintenance on the vault and collection and treatment of the leachate
would cease under this alternative. The only continuing activity
would be monitoring.
8.3 ALTERNATIVE 2 - SITE RESHAPING. CAPPING AND LONG-TERM WATER
MONITORING
Alternative 2 would consist of several steps. First, the sump pond
and leachate pond would be drained. The water would be treated by
the existing leachate treatment system and discharged to the North
Pond. After the ponds are drained, the top 15 feet of the vault soil
(10,300 yd3) would be moved to the ravine area west of the vault
and the hog barn. The ponds would be filled to approximately 120
feet mean sea level (msl) elevation with soil from the upper five
foot zone of the vault. Contaminated soils near the silo would also
be excavated, moved to the ravine, and spread. The remaining ravine
area would then be filled and covered with one-half foot of topsoil
to act as a temporary cover. This would bring the elevation of the
ravine to approximately 133 to 134 feet above msl and the top of the
remaining vault soils would be at an elevation of approximately 145
feet above msl. The berms and the vault would be regraded to reduce
sideslope steepness to 2:1 (horizontal:vertical).
The final cap over the vault would consist of a two-foot clay layer
(permeability less than 1 x 10 cm/sec), a flexible synthetic
membrane (30 mil thickness), a one-foot sand drainage layer, a
two-foot topsoil layer, and cover vegetation. This cap would cover
an area of approximately 152 feet above msl. After completion of the
cap on the vault, the North Pond would be drained and filled using
soil in the retaining berm. The ground would be graded to achieve a
slope similar to surrounding areas. The entire filled area would be
covered with a two-foot topsoil layer and seeded with vegetation.
This would require approximately 3500-3700 yd3 of soil to cover 1.1
acres. Run-on and run-off diversion ditches would be placed west of
the ravine area and south and east of the vault. Run-off from the
cap would discharge across the former North Pond via the natural
slope. Long-term monitoring of groundwater would be necessary for
approximately 30 years. Treatment of vault leachate would be
discontinued, but treatment for contaminated groundwater might be
required in future years to meet ARARs.
The time to finish the cap depends on many variables including the
weather conditions, availability of materials and the size, type, and
quantity of equipment used. For screening purposes, it is estimated
-------
-22-
that construction will require 3-6 months.
8.4 ALTERNATIVE 7 - IN SITU BIOLOGICAL TREATMENT. WASTEWATER
TREATMENT. SITE REGRADING. TOPSOIL COVER AND
SHORT-TERM MONITORING
This alternative would consist of in situ treatment of vault soils by
applying and recycling water and nutrients to the soil to enhance
biodegradation of contaminants. Water and nutrients would be applied
at the top of the vault and leachate would be pumped out of the
bottom of the vault and recycled back to the top for reapplication.
Biological seed from an offsite source would be applied to the soils
initially and as required to enhance biological treatment.
Following the transfer of the top 20 feet of the vault soil to the
ravine (after appropriate sampling), the vault would be fitted with a
water application system, and a leachate recovery system. Leachate
would be pumped from the recovery system to a holding tank where
nutrients would be added. This water would then be reapplied at the
top of the vault at a steady rate. Treatment would continue until
analysis of vault soil samples indicated that RAOs had been
attained. After soils have met cleanup objectives, all leachate
would be pumped out of the vault and the vault area and ravine area
would be covered with a two foot topsoil layer. The ponds would ba
drained and filled with soil from the berro of the North Pond. The;
site would be regraded and seeded. Run-on and run-off controls wouxu.
be installed as in the capping alternative. During the soil
treatment process/ excess water may be withdrawn from the system to
maintain the correct water volume in the vault. This excess water
would be treated by filtration followed by carbon adsorption or UV
oxidation and discharged to the North Pond. The water treatment
system would also treat the final leachate pumped before site
closure. Groundwater and surface water monitoring would be conducted
while the treatment process was being operated. After remediation,
monitoring of site groundwaters will likely be necessary for an
additional five years.
Major components in this alternative would be one to six pumps, a
leachate holding tank for nutrient mixing and equalizing recycle
flow, four or acre leachate recovery wells in the vault, several
concrete pads, a spray header system or other leachate application
equipment/ and water treatment equipment for any excess water from
the system. The system flow is expected to be in the range of 5,000
to 15,000 gallons/day. The time required for completion of treatment
could be quite variable depending on bacterial acclimation, pumping
rates and the permeability of the vault soils. Time to complete in
situ biological treatment is estimated to be from 2.5 to 5 years.
A variation of this alternative would be to add a waste activated
sludge bioreactor tank to the treatment system between the holding
tank and the vault leachate application system. This option would
provide additional leachate treatment and provide additional
-------
-23-
bacteria to the vault soils. The additional bacteria would enhance
treatment through increased bacterial contact with contaminants
attached to the soil. This variation of Alternative 7 would require
one to two additional pumps, a biological reactor tank, an air
blower, and additional piping and appurtenances.
8.5 ALTERNATIVE 8 - COMPOSTING/WINDROWING. WASTEWATER TREATMENT,
SITE REGRADING. TOPSOIL COVER. AND SHORT-TERM
MONITORING
This alternative would use composting/windrowing to biologically
treat soils with contaminant levels above cleanup objectives. The
hog barn structure would be demolished and the floor slab modified to
accept the soils to be treated. Modifications would include
installing a run-off collection system, and a water application
system. The floor slab integrity would have to be evaluated prior to
modifications. After the slab is ready, the top 20 feet of the vault
soils would be transferred to the ravine area. This soil would be
sampled prior to its placement in the ravine to assure that it met
the cleanup criteria. A portion of the remaining vault soil would
be placed in piles (windrows) two or three foot high on the slab.
The process of moving the soil from the vault to the soil treatment
area would result in the volatilization of some of the volatiles.
Air monitoring during this operation would be undertaken to assure
that excessive volatilization was not occuring. The slab is
estimated to hold approximately 500 yd-* of soil. Wood chips or
other similar bridging agents would be added, if necessary, to
enhance aeration of the piles. Water and nutrients would be added to
the top surface of the piles and the piles would be periodically
turned for aeration. Biological seed would be brought from an
offsite source and applied to each new volume of soil transferred to
the slab from the vault. A new roof would be placed over the slab to
protect the piles in heavy rains. Drainage from the piles would be
collected the run-off collection system on the slab and treated (by
filtration followed by either activated carbon adsorption or UV
oxidation) before discharge to the North Pond. After treatment had
reduced contaminants to below the cleanup goals, the soil would be
moved to the ravine and a new batch of contaminated soil moved to the
slab for treatment. Contaminated soils near the vault would be
excavated, Moved to the slab, and treated along with the vault
soils. After treatment of all vault soils has been completed, the
vault area would be backfilled with clean topsoil from offsite. The
ponds would be drained and filled. The ravine and vault areas would
be covered with a two-foot topsoil layer (7,000 yd3) and the site
regraded and seeded. Run-off and run-on controls would be
constructed as in the capping alternative. Site monitoring would be
followed by short-term monitoring program (approximately 5 years)
after remediation was completed.
Major components of the composting/windrowing alternative would be
several pumps, a water distribution system, a leachate storage and
treatment system, and a frpnt end loader for mixing soils piles, it
is estimated that each pile will require approximately three months
-------
-24-
of treatment. At this rate of cleanup, remedial action would take
approximately 5 to 7.5 years. The slab size and the volume of the
piles could be increased to reduce this time period. A variation of
this alternative would be to use air blowers to aerate the piles. An
air distribution network could be incorporated into the slab during
engineering modifications. With forced aeration of the piles and
increased slab -size, it is estimated that treatment time would be
reduced to two to three years.
8.6 ALTERNATIVE 9 - CQMPQSTING/WINDROWING. IN SITU BIOLOGICAL
TREATMENT. WASTEWATER TREATMENT. SITE
RESHAPING. TOPSQIL COVER. SHORT-TERM
MONITORING
This alternative is a combination of Alternative 7 and 8. The
composting/windrowing component would be the same as that described
for Alternative 8. The in situ component would be similar to
Alternative 7 except that only the existing leachate pump would be
used to recover water from the vault. Recycled water and nutrients
would be applied to the top of the vault via a low velocity piping
system. The system would be dismantled and reassembled for each lift
of vault soils transferred to the slab for composting/windrowing.
Biological seed would be brought from an offsite source and applied
to slab soil piles and the vault soils at specified time periods
(each time a new soil lift is transferred to the slab). Leachate
from the vault would be recycled through the vault after the addit A
of nutrients. Excess recycle leachate would be treated as described
for Alternative 7.
Major components of this alternative would include those in
Alternative 8 plus the vault leachate application equipment, pumps,
holding tank, and excess water treatment units for the in situ
treatment system. The treatment time is expected to be in the two to
four year range. Upon completion of treatment on the slab and
transfer of all vault soils to the ravine, the vault liner would be
removed and the vault area backfilled with clean soil from offsite.
The ponds would be drained and filled and the site would be regraded
to match natural contours as closely as practical. A two-foot soil
cover would be placed over the ravine and vault areas, and the site
would be seeded.
8.6 ALTERNATIVE 10 - ONSITE INCINERATION. SITE REGRADING AND
TOPSOIL COVER
Alternative 10 consists of moving the top 20 feet of the vault soil
to the ravine area. This would be followed by rotary kiln
incineration of the soils that are above cleanup goals. Incinerator
residue (soil and ash) would be backfilled in the vault excavation
along with additional borrow soils. Upon completion of treatment,
the vault and ravine area-would be regraded, and a two-foot layer of
topsoil will be placed over those areas.
-------
-25-
The mobile incinerator equipment would require a minimum of one acre
of land. Based on this requirement, the incinerator facilities would
be located in the open field east and southeast of the vault. A
large baclchoe would be used to transfer the lower 15 feet of thevault
soils (approximately 15,000 yd3) to the incineration pretreatment
units. A scale and soil crusher would precede the rotary kiln,
respectively, to measure the soil tonnage incinerated and to break-up
any large clumps of soil. The kiln can accept particles up to 4
inches in diameter. An elevating conveyer system would transfer the
soil to the kiln. Ash from the incineration would be disposed onsite
after the ash is determined to be non-hazardous. The site would be
regraded and seeded as described in the other alternatives.
9.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
In this section, the alternatives are compared to each other based on
the first seven of the nine criteria on which the Agency bases its
decisions on remedial actions. Table 5.1 outlines how each
alternative compares with the selected criteria. Because the' last
two criteria are determined after the public comment period, they are
evaluated separately.
Alternative 1, no action with monitoring, posed potential future
risks to human health and the environment. The vault's southwest
corner has already slumped and further deterioration can be expected
with the possibility of exposure of contaminated soils at the ground
surface. It is also possible that contaminated water could seep from
the vault, at the ground surface or leach into the perched
groundwater from the vault, at the ground surface, or leach into the
perched groundwater from the vault. This alternative does not
provide source control and provides no reduction in toxicity,
mobility, or volume of site contaminants. This alternative would not
meet soil RAOs and could cause water RAOs to be exceeded in the
future. This alternative is the least costly of all alternatives.
Alternative 2, capping, would minimize infiltration of water to
contaminated soil and eliminate the soil ingestion pathway. However,
the contaminated soils will be a source of potential groundwater
contamination. If the cover should fail at a future date, human
exposure to coils having concentrations approximately equal to those
found in th» vault at present could occur. Uncertainty also exists
as to what effects the bottom liner of the vault will have on the
overall effectiveness of this remedy. The capping option would not
be difficult to implement technically, and would require three to six
months to complete. However, capping does not meet SARA provisions
that favor treatment as a major component. This alternative would
meet site soil and water RAOs in the short-term; however, ARARs for
water may be exceeded in the future. Implementation of the
alternative would not pose significant health risks to site workers
or nearby residents. Except for Alternative 1 (no action), the
capping alternative is the least costly alternative.
-------
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See Allcnt
-------
TAUI.I-: S.I ( ouliniinl
Al II UNA IIVI (Kill Kl A ANSI SSMI NI
.i ssmi HI l-jiiiu* AlMIIMiJM 1
(NoAc*»)
Adci|iui y ol No engineering rontrott to
i »ni i »lv pi c VCM human MgcUMM of
OMiiaMMiaicd tuilft of
Nn control over luiurr
degradation irf
groundwaici or turlacc
wjtri or ol the vault linen
Monitoring will track
conlamittani plume i in
ground or turtacc watcn.
hul will not remediate the
lite
Id lialuliiy irf No action will lie taken 10
1 oniioli conlnilMtt unit
Allrm.ilivc I
(( apping)
( *ap will prevent duct 1
cipnturc in contain
mated MH|, l>ul will not
roulct Ike vault could
till with inliliralton water
rauttng contaminant
migration ctlhei to the
lurlare vu vault icepagc
or iu Ihc pcnhed waici
lal>k Ihnwgh the liollom
liner
1 he rap would require
maintenance and |M*»I
AllciiKiive 7 Alicm^iive K Alieinaiivc •> Allcrnalivc HI
(In Situ lltotogKtl) (( oni|MiMing) (( ombtned 7 and 8) (lncmcralion|
Iwo loot lopviMl Uyei 1 w|Klli
-------
lAltl.K 5.1- < onlimicil
All I UNA 11VI ( Kill KIA ASSI SSMI Nl
AVM \MW in 1 M lor.
AhCMMM 1
(NoAOMM)
Alliinjlrt 2
Allcin.ilivt 7
tin S«
AlirmJIivc H
(( >ini|Nttiing)
Alicm^nvc V
(( omhmcil / jnJ H)
HI
v. IfcaimcM icwditaU
Hrmaininf, Alter
Mont in vciy Milt
Hi> iicM ..I
the IfNA f«nnpi>uiMb
witukl Iw icnwivcj fcnu
r.siiniaie J ihal tiver hall ol
the I l-NAi would be
i e moved I'enlxhkiro-
phenol lemiivil unrenun
I'lloi u ale leilv needed to
<|u«nlrfy irmuval met and
Sec Allcrn^livc H
urucnam
liejimcnl » irrcvenrfik Sec Alienxlive 7
IVA and ITNA liHiil<|ia Sec Alltinative 7
dalton by (inidm u ace
l'eniKliloni|ibtni4
by pniiturli could l<
piiieniially lour
A|>pn>llinalcly 1 1>M ID
I VIM) yd i4 vml «t>uW lie
See Aliccnjlivc 7
Sec Allcnulivc 7
Ninety |teffenl 01 gieaui
tletinuiitiQ of trtMl
ctmiaimnanlfc u e«pcfic«l
All KA«I Icvck will Iw met
Sec AllcrnAlivc 7
lieatmcnl ictiduaU
inrludc kiln and (wnitk
uiulilwi atb, cooling
•alei. and pnireu tlai k
gu IFNA ami
kv
-------
TAltl I 5.1 < onlmmcl
Al 11 KNAIIVK < KIT) KIA ANSI SSMI NT
\\M\SIIHIII I aiiurv
Alternative I Alternative 7
(•..ipping) (In SuulhohigMall
Allorulivc H
Alternative *'
(( 'itnibincil 7 and H)
Alternative III
Sh.Hi I HIM I lltflivrneit
I uitr until «iIHMI u I lo 2 MUMki lo tMlatt Apprntimaiely I in
muottorMl nclb. •MMlhi
• I ommuiiily
I'cnheil gniunJwauc and
tuil«c tce|tagc (nun Ihe
vjuh may pi»t a ntk lo
tile Impaucn Aihlihtiaal
ilump>n| «4 the vault ctMiM
ei|«i»c MIC iitvpaucn lo
tiMiiaminatcil Mill
'Ibc IN aliecnauve nvk
aucwmcnl (AppenOn II)
imliraict < *i> imigcoH
niki l» neaitiy feuUcnii
and thildicn urspjucn
Inwn mhalaiHin «nil oul
cip>Mi»e aic Ixliio 2 "
10 Mint laifinti^eiiu
iiklik are well beltiw
IISI »'A guiiklinci
yean Ariual iit*imeni
lime tiiuU lie kmgci
Sec Allemalive 2
I King eiiktmg lUh and \
mimih Cklimated pik
(regiment lime, alternative
may laic up to 7.S yean to
nxnpkie II ihe (lab MIC u
liifileil Ireatnienl lime n
tkhmaictl 1*1 IK 2 4 yean
Same at Alternative 2
eitcpt carcinogen* ruk
I mm oral and dermal
cipiiMire loi fhiMrc*
lieipaucn u J 77 110
and lor miikcn u 2 4) >
10 * wkHh arc boik ouutdc
Ihe IISIil'A target ruk
range Mimevcr. the
eipinurt aucumcnl
appnwrh w»k cilrcmcly
rontcrvaiivc and auumed
dermal and ma! i
o be 2 io4
lUiu II immihi ii>
ci>m|4cle sue wmk
Sec Allcnutive It
Sec Allcin*livt 2
-------
TAIll.l'. 5.I--4 onlimu-il
Al II KNAIIVK < KITKKIA ASSI SSMI Nl
i* AJttMMb* 1 Alieinjiivc 2
(N* ActfM) (< *pp»nt >
Altrinjlive 7
(In Situ llMidigH jl)
AllniMiivc 8
((«Mn|«Atiag)
Allernjtivt •*
(tincd7andH)
Alteinitivc III
(IwuKtalma)
Ni> MgwTirMU ink IO
•MM ken dunaf uumfku^
lite IN alienuiive nsk
aMC^kmcm |Ap|icntliB II)
me wiMkcn lumi
ct|MAuR mulct *re
hrkm I • III* Nim
mil hchiw I ISI I'A
guide line*
Sec Alirin«livc I
< «i> im>(;rnH n\k limn oial
•ml iltim«l e»pi»«ic IIM
chiMicn licvp*iitri iv 2 III
• III ami IIM Milken 11
I JVi l04whirli*lct>.Mh
ituUHle Iht; USri'A laigel
lull langc howevei. I he
eiptnuir aucumenl
•ppnwt h w»» eilremely
ronwiviiivt and •uumeil
Jecmad duiing
I miuiixu irf wilalik
organia and partirkct
dyimg cicavalMM acimlKi
arc IMM cuouderctl lo
Ufniliraaily impact an
quality Inuallaiiun irf
lopvHl rove i may uurcasc
tedimeai kMJu>| to pondi.
pnoi lu liUinf
See Allcinaltvc 7.
Sec Allcrnaltvc 7
VoUulc. iHm volalik. aM
panuk cmiUHMU Inm
tnrineraiiun ai«l/»f
euavalHM arc IMM
ei|>eited lo imjaii HI
qiMlily IflitJlUlMMi til
liipMMl iuwci may iiu*fc«»c
ledimcat loading to
-------
I Att
TAItl.I-: 5.1- (onlinmril
Al II KNATIVI ( KITKKIA ANSI SSMI NT
» AlMIMMMl
(NoAflfcM)
Allrrnalivc 2
(( a|i|ung)
Allrinalivc 7
(In Situ IhologMaO
Allrm.ilivc H
(( tini|NAting)
Alteinjiive ''
(Combined /antltt)
Atacrnalive III
(IwuktralHin)
— Ability lot'|ieiaic
Wel
umplMf CMily
iinptca»cnlcd
Cap tOntllUtlMMI ami
maintenance will not IK
dillicull
I 'umlrUilMIQ will mil I>C
iliflicull Water ditlnhu
IHHI lyMcm auy R«|UIK
tpct ul *p|Miiicn>nfck ut il
i an he Jiuukul ibc
»yMUilup Aliilily loopcialc
bejvy ai| barn
See Ahemalivet 7 anil N
m\
nmlilMly pertnrmetl
4 ap ciwhl IK imparted
by future land uct
Potential lor
(Oiumlwatei
See Alteinjlivr I
Tipanding t ap Jmien
SMKI& wouM rci|unc
drnu*lilioii .ind irniovjl
ol hogILIIII
Simpluuy and •ulomalino
ol kytiein aukci reliability
high Ihiwcvcf. Ibe vmull
liner may leak reuiltin| in
ideate ol reutlual
conumuunli to ibc
(round water
S.«li would ttill be in vault
and riiuld be cu'avated il
luilhcr ailion itdeemt>l
nueuary AilditHinal
water licaimeni is
HI i aibon unit^
Keliabilily ol windrowiug
relict on maintenance of
conditions conducive lo
bat icnal acimly and o«
lime tpcnl and care cicr-
ciud m turning of tod pdct
and wetting pdct. IJllk
down time anticipated.
Additional MK| could IK
Heated but may tubilan
tMtly in< icaM remedial
i>Mn|>leiion tune Watci
liiainirni wouli
Sec Alternativet 7 ami H
See Alternative H
Prureu u well leucd aiwl
rcliabte IhMm lime >NI 14
hour upcrvlKMi whcdulc M
ektimaled to be l&\.
Athlilional MM! muM he
in< ineratcd wiih no
iniriruplHHi in tttjiniciu
lyMent
-------
TAltl I 5.1 < onliniHil
Al II KNATIVI < KITKKIA ASSKSSMIiNT
Assessment 1 ailiirt AlMlM** 1
(N.A*»>
• Alulny lonHmilor MnMorMf of mrfere and
ellei lively glMMdMICIS watt deleft
i—n't/mti"— •HftMH«
effectively. Majtalionol
mil IMII addrctted
••• •
Alleinalive 2 Alleinalive 7
(lapping) (In Situ Hn4iigM.ll)
Same at Aliernativc 1 Moniioimg perlormame
would lie dillNuli 1 Icier
mining hi*w many MM|
tampkt arc needed to
repretenl ol all the vault
UMlt Will 1* dllltfull
Moniioimg ol recycle
walel it nm likely lo
Alleinalive H Alternative V
1 1 . imputiing) (< 'ombmcd 7 and H )
I'liavjimg and turning id See Alternative H
t4Hl will inr icate k4mti>-
geneily ill MH| Se done on Ike tlab
Alternative III
n>i>hcn»l MOt'C
lht»c are highly adxi
liilbc KM!
Iratihilily
AvailalMhly i
irivkct and
male nalt
NII ptmuti ot rumlinaiHMi
•miMg tfcncxt
AH equipment and ttnntt
•vailaMe I-oral lalwxalory
it availabk fur analylif al
tccvirct III 'I P pimorirf-.
•ic lequired. latMiialtwy
avaiUtiilny will Iw OMUC
limited
Mm lavored hy SARA
pmvitHMU. l>Ul OpIMM
ka* been applied al many
il-KCIAuiet
IMjuipmenl and tervuet
eatily availabk (lay
source it likely lube out
ol tlatc Sue woikeit
would be required lo
have a rcrlilh ale ol
naming Irom a 411 hnui
ha/aidout wa%lc health
and ifamnigioui»
At a liealmenl melkod.
alieinalive wiH n»eei SARA
poMHunt Pcnnilt would
nm be icquired unrc
wane wale n mU be
divkargcil on uie
IU|uipmenl it availabk
ferwMoel opcialin| ibc
tyMcm wiiuhl be lequiKd
In kjve a tenilMate nl
naming I mm a 4O hnui
ha/aiihius watte bealib and
valely ioui\e
Will meet SARA Ireaimenl
piuvUHNu NII perauu
icquiieJ
See Aliemauve 7
Sec Alternative 8
Sec Alternative 7
I nal burn will be net e
tl in. ..u
alum tytleim aic availji.
Sue worker* wouhl l«
rei|uirrd lo have a
lenifiraie .»! nmining ti-->
a -to huui h.i/ji.l. »u* MU i
llll.UII
J.> S-1HIH.I
tl
-------
TAIU h 5.1 < onlii
AI 11 KNATIVI CKITKKIA ASSI<:SSMI-:NI
ASM \simnl
- - — ' /
Ij.l.pr* ftlUnaHltl 1 Alternative 2 Alternative 7
(NnActio*) (CappinK) (In Siiu llrokigical)
IAM<>«u SNi.OnO (yean 1 S) J>,(.IIU»(ye.m 1 S| tIM.IMMycan 1 S)
tU.OUO(yc*n6-JO) }|1.(HU(ycaaA Ml) tlU.IMI (ytan b-IU)
Allrnitilive H
(( 4>ni|Mi&ting)
lllS.limilve^n 1 ">)
tlU.mill(yearM> 10)
Alternative '< Allcrnalive III
(t iHnbincd 7 and H) (lacMcratuMi)
„.,..„;,.„>,
i Wi.nb iisi.ono
t mi (eaptial COM
thai
AHAIUartcireeded
l-uiurc dticnonltrm uf Ibc
vault makes Iranipon uf
MMK and cool* I J>»K not
degiadalion IJ>i»
alieinalivc nmtukl not
gene rale pn>rcu WMICVJI-
lei <» Ireaimenl MIC.
W«ici HA< K uM be
me I
S^me j& Alternative H
e ire pi pcnlathlont-
phenol KA(H aie moic
likely lube met because
Inalmcnl will he
initialed in Ihe vault and
continued in windru*
(diet
iMMi w<»uM H
MM| KA< K W*iei «
be iimiumcd in the
-------
IAIII I1S.I (onl.iiiu.l
AI.TKKNATIVK < KITKKIA ASSKSSMKNT
A\\* \\MII HI I 44 it i
AlMlMIMl
(NoAMM)
AlieiitJliM 2
Alicinjlive 7
(In Situ lliiifcigMal)
Aln iii.iuvc K
Allrininv. '*
(('••mhinej /
Alumjiivt HI
(lactncfaiion)
I i.ill l'i.iii|
I linn itilk «ic climi-
n^irtl. icdwcJ <»
AllcmMivc «!•«»
MldicM MMC mki M ibc
UlC VMillMNliWlH
riwiiiMic lo be • p»»iiMc
UHlll'C III gllNMMl Mil
kuilarc »*in
otouminaiHMi and even-
tually, il cipukcd, Iw a mfc
In human fcrahh via
wuukl MM pi\>»e(i human
health ot i he cnvinMOKM
4 "«|i|Mn| will pn vr ni
ducti eipi»urc in
raoiamuialcd tml\
CtMlaiMHMICll MM!N will
nmlMuc li> lie a |»i^ililt
kHi| Item WHIIIC ill
(itHinil ami kurfaic w«iet
runiaminaiMMt W«ici
Kcalmcnl. il
impkmenieJ. miulJ
pnMcrl human health
•ml cnvmmmtnl
I «.•• (mil ciwc* will cllcr
lively pievcnt direct
iimtat I with trcMeil Mull.
I icaiment i4 MMh will
icilwe moa til fiwiami
n*nl» that i«n Icai'h into
the (iccihtJ waiei t
Ve Aliciiuiive / See Alitntalive 7 See Aliernalive /
Alleiiitfiive iieipcctcd lo Alieroalive u eipeclcii Heuilual nik ..I n<
lie j| i-iuiununanu lo HA( > to meet HAOi mute MNU it very low
kvcK on nt elleilivcly than IIK< eulully th^n
AllciiiAlive 7 AllcinaiivCk 7 in H
-------
-26-
Alternative 7, in situ biological treatment, relies on the bottom
liner of the vault being intact; otherwise, contaminants and/or
treatment by-products may leach into the perched water-table. In
situ treatment of the contaminants in the vault is enhanced by
aerobic conditions. The degree to which aerobic conditions can be
maintained in the vault is not certain, and would require full scale
operation to determine. Nitrate could be added as a terminal
electron acceptor in the in situ system should oxygen levels drop too
low, but nitrate might be transported to the perched water-table.
Alternative 7 would not be difficult to implement technically. This
alternative would meet SARA provisions by utilizing treatment as a
major component of remediation. However, monitoring the
effectiveness of the treatment system would be difficult because of
the difficulty in obtaining representative soil samples. This
alternative is expected to meet soil and water cleanup goals, but
actual performance must be determined in full-scale operation.
implementing this alternative poses health risks to workers, site
trespassers, and nearby residents that are within USEPA guidelines.
This alternative is approximately 1.4 times more expensive than
Alternative 2.
Alternative 8, composting/windrowing, is a more easily controlled
system than in situ biological treatment because treatment is
accomplished above ground. Since aerobic conditions will be easier
to maintain, this alternative is more reliable and is expected to
treat site soils to lower residual concentrations than in situ
treatment. This alternative would not be difficult to implement and
will meet the SARA treatment preference. Monitoring the
effectiveness of this alternative would be easier than in situ
treatment. The mixing and turning of soil piles will make the soil
more homogeneous and grab soil samples will be more representative.
This alternative is expected to meet soil and water RAOs; however,
pilot testing is required to confirm system performance. This
alternative is approximately equal in cost to the in situ treatment
alternative.
\
Alternative 9, in situ treatment and composting/windrowing, is a
combination of Alternative 7 and 8. The in situ component is
considered a supplement of composting/windrowing. The primary
advantage of this alternative would be to reduce the treatment time
required because acclimated bacteria in the vault would be
transferred with soils to the slab. As in Alternative 7, the
uncertainties associated with vault bottom liner would be a concern
in this alternative. Monitoring the effectiveness of this
alternative would be the same as in Alternative 8. This alternative
would not be difficult to implement and would meet the SARA treatment
preference. This alternative would pose approximately the same
health risks to workers and children trespassers as Alternative 8.
The cost of this alternative is greater than Alternative 8 by
approximately $275/000.
-------
-27-
Implementation of Alternative 10 will result in the lowest residua.
contaminant concentrations in the soil of all treatment
alternatives. Incineration will reduce all contaminants to below
soil RAO levels. Implementing this alternative would require that a
rotary kiln be available and would require a trial burn to test the
effectiveness of the treatment system. Ample water and power
supplies would be necessary/ but it is believed these supplies would
be available. Health .risks to workers, children trespassers and
nearby residents are within USEPA guidelines. Incineration is
approximately five to 10 times more expensive than biological
treatment and 20 times more expensive than capping.
10.0 SELECTION OF REMEDY
The selected remedial alternative for the DOPC is Alternative 8. A
process flow diagram of this alternative is provided in Figure 5.5
and a more complete description can be found in section 8.5 of this
ROD. This remedy satisfies all of the statutory requirements, as
discussed in detail in Section 11.0 and provides the best balance
between the nine criteria that the Agency uses to select a remedial
alternative. This alternative will remediate the source to
contaminant levels below RAOs that are protective of both human
health and the environment. Although groundwater from one
downgradient well did contain contamination slightly over allowable
levels, it appears that this low level groundwater contamination
occurred prior to the containment of the contaminated soils in the
vault. This low level of contamination is expected to degrade
naturally in a short period of time and, consequently, does not
require active remediation.
11.0 STATUTORY REQUIREMENTS
The Agency has determined that this remedy satisfies the statutory
requirements of providing protection of human health and the
environment, attaining applicable or relevant and appropriate
requirements (ARARs) of other environmental statutes, will be
cost-effective and will utilize permanent solutions and alternative
treatment technologies or resource recovery technologies to maximum
extent practicable. The remainder to this section discusses how the
statutory requirements relate to this site.
11.1 PROTgCTIVB OF HUMAN HEALTH AND THE ENVIRONMENT
The selected remedy of bioremediation of the vault soils and selected
hot spots is protective of human health and the environment by
reducing the levels of contaminants to below what would cause an
unacceptable threat to human health. This remedy would also result
in residual levels of contaminants that would not leach into the
groundwater in significant enough levels to and to the groundwater.
-------
m
in
«*i
j»
z
m
fH
•m
X
o
1
K
o
m
ALTERNATIVE 8 PROCESS FLOW DIAGRAM
/ DUBOSC OIL PRODUCTS COMPANY SITE
•TREATED I t ACMATE-*
77/77^*
^
1
Mt
~ •*~*/W.
. ^,^^
MOUTH POND
tf. ,
BIOLOGICAL
SEED
SOURCE
1
1
\/
MAKEUP
WATER —
^-fo\
MAKEUH
WATER!
PUMP
t
NUTRIENTS TO PILES 1
T _ 1-
• BIOLOGICAL SECD TO PILES [
LEGEND
- CONTINUOUS f LOW
- - PERIODIC flOW
L«
4 EILTER
rS r— 1_ f— 1 •VfcWTLEACMATC-'
n n^3 — i 1 •
LJ ; '
CARBON T |
COLUMNS BACKHOE i
_ •- 6^^) I
CONTAMINATED >v X^
SOIL X X
TO SLAB
- »^ VAULT
n
I
1.
^^^
^^^^ 1 ^"^^x^^ ^ SHED ROOF
jX^WATCR DISTRIBUTION 1 ^^«x^
U U U A U M 1 U U A A
/- \ X- X X^~X TREATED SOIL TO STORAGE „„„.,,
/ \ / \ / \ A*tA
fc / SOIL PILt \ / y^ \
X u-r ..„„ ,... lili SLAB AND STORAGE AREA
HOG BARN SLAB f f RUN-OFF COLLECTION SUMP
^ ,_ ~t
RUN-OFF V«CTER S2/
REAPPUED TO SOIL SUUP
PUMP
T1
o
f
^
m
u«
i/*
-------
-28-
11.2 ATTAINMENT OF THE APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENTS
Remedial actions performed under Superfund must comply with all
ARARs. The following ARARs were identified for this site.
11.2.1 CONTAMINANT-SPECIFIC ARARS
For water media, USEPA considers drinking water Maximum Contaminant
Levels (MCLs), Federal Ambient Water Quality Criteria, National
Ambient Air Quality Standards (NAAQS) and state environmental
standards to be contaminant-specific ARARs for ambient
concentration. Table 2.2, found earlier in the ROD, lists these
ARARs for each of the contaminants of concern at the DOPC site.
These ARARs are for water only and they represent target levels for
remediation only if contaminants occur in surface water or
groundwater. There are no contaminant-specific ARARs for soils or
sediments at the DOPC site.
11.2.2 LOCATION-SPECIFIC ARARs
Location-specific ARARs are restrictions on remedial activities in
especially sensitive areas, such as wetlands, floodplains, or
historic sites. During the RI study, it was determined that there
are no sensitive environments (wetlands), endangered species habi s
(aquatic and terrestrial), historical sites, or floodplains affeci
by the DOPC site. Therefore, no state or federal location-specific
ARARs apply to the DOPC site.
11.2.3 ACTION-SPECIFIC ARARs
Action-specific ARARs are enforceable state or federal requirements
or standards applicable to each remedial alternative. Federal
statutes which may apply are as follows:
" Resource Conservation and Recovery Act (RCRA) - The provisions
of these acts are "applicable" to remedial alternatives because
they govern the remedial action chosen, the disposal of
Superfund wastes and future monitoring requirements. RCRA
requirements that are applicable to remedial alternatives
includo ainimum technology standard, treatment standards,
monitoring requirements and prohibitions on landfilling of
liquid and specified solid hazardous wastes. If offsite
treatment or disposal is chosen as a remedial alternative, RCRA
requirements for hazardous waste generators and transporters as
well as land disposal requirements and other requirements for
treatment, storage and disposal facilities must be met.
-------
-29-
' Clean Water Act (CWA) - Remedial alternatives that require
discharge to waters offsite must comply with provisions in the
CWA. Administrative procedures for obtaining a permit for
onsite discharge are not required, but offsite discharge
standards may be applicable.
0 Clean Air Act (CAA) - This act may be applicable for those
alternatives where contaminants may be released to the air
(such as stripping or incineration). For onsite treatment
alternatives administrative procedures for obtaining a permit
are not required, but offsite discharge standards may be
applicable.
Certain Florida state laws may be applicable to potential remedial
action alternatives. Florida Resource Recovery and Management
Regulations, Florida Hazardous Waste Rules and Hazardous Waste
Facility Siting Regulations (Chapters 17-1, 17-30 and 17-33) may
apply to offsite or onsite disposal of solid wastes at the DOPC
site. Florida Water Quality Standards (Chapter 17-3) may apply if
future contamination of surface or groundwater and subsequent offsite
releases occur. Florida Air Pollution Rules and Ambient Air Quality
Standards (Chapters 17-2 and 17-2 part III) may be applicable if
remedial actions result in emissions of regulated compounds to the
atmosphere.
11.2.4 TO BE CONSIDERED CRITERIA
To be considered (TBC) criteria are those criteria, which although
not required by or based on federal statutes (as ARARs are), may be
applicable to the DOPC site. The USEPA is now considering "to be
proposed" MCLs and MCLGs for xylene of 10 mg/1 (fed. Reg. Vol. 54,
No. 97, May 22, 1989). This level constitutes a TBC criterion for
the OOPC site.
\
11.2.5 ARAR ATTAINMENT
All other alternatives, with the exception of Alternative 1, would
meet their respective ARARs and cleanup goals. The contaminated soil
is not a RCXA hazardous waste and is currently under the soil and
debris exemption to the Land Disposal Restrictions (LDR). Therefore,
the LDR are not ARARs for this site. No waiver from ARARs would be
necessary to implement the active cleanup options.
11.3 COST EFFECTIVENESS
EPA's selected remedy Alternative affords a higher degree of overall
protectiveness in not only protecting the public against direct
exposure to surface soils but also in removing the threat of future
contamination of the adjacent wetlands. The present worth estimated
-------
-30-
cost of EPA'a selected remedy is approximately $3,000,000 dollars.
This remedy employs a proven technology which can be implemented year
round and has been proven to be a permanent solution for this type of
contamination. The selection remedy affords overall effectiveness
proportional to its costs such that the remedy represents a
reasonable value for the money. When the relationship between cost
and overall eftectiveness of the selected remedy is viewed in light
of the relationship between cost and overall effectiveness afforded
by the other alternatives, the selected remedy appears to be
cost-effective.
11.4 UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT
TECHNOLOGY OR RESOURCE RECOVERY TECHNOLOGIES TO THE MAXIMUM
EXTENT PRACTICABLE
U.S. EPA believes this remedy is the most appropriate cleanup
solution for DOPC site and provides the best balance among the
evaluation criteria for the remedial alternatives evaluated. This
remedy provides effective protection in both the short- and long-term
to potential human and environmental receptors, is readily
implemented, is cost-effecive and is consistent with future response
actions that will be undertaken at the site. Bioremediation of the
contaminated soil represents a permanent solution (through treatment)
which will effectively reduce and/or eliminate mobility of hazardous
wastes and hazardous substances into the environment.
11.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
Organic chemical contamination in the landfill is the principal
threat at the site. Bioremediation is a treatment process which has
been demonstrated to effectively treat organic chemical contamination
to acceptable levels.
12.0 REMEDIAL DESIGN
This section identifies activities that must be accomplished during
the remedial design phase before the Agency approves the
implementation of the remedial action. Additional activities may be
identified daring the design.
12.1 TREATABILITY STUDIES
Pilot scale treatability studies will be conducted during the design
in order to determine the best method of implementing the
composting/windrowing process. Emphasis will also be on determining
the most effective way to bioremediate the pentachlorophenols.
Emphasis will also be on determining whether contaminants are being
treated by the bioremediation process; not merely being airstripped
by physical movement of the soils.
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12.2 WETLANDS
Additional sampling will be done in the wetlands to the Immediate
north of the North Pond to confirm the presence or absence of
contamination in the area which might have resulted from the breach
in the dike.
12.3 CLEANUP GOALS
There were six "hot spots" of contaminated soil outside the vault
identified in the RI. The appropriate computer modeling, as done for
the soil to be placed in the ravine, will be done to determine
whether these spots can be left in place or whether they should be
moved to the ravine area.
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APPENDIX A
RESPONSIVENESS SUMMARY
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STHQARY
Dubose Oil Products Site
Cantonment, Florida
Overview
The DOPC was proposed for inclusion on the NPL in 1984 and finalized
in June 19S6. In 1985, the FDER conducted an Emergency Removal at the
site that consisted, of excavation and onsite containment in a vault of
contaminated soil and installation and maintenance of a leachate
treatment system for the vault. In 1987, FDER signed a Consent Order
(CO) for the performance of a RI/FS with the potentially responsible
parties. The RI report, which examines air, sediment, soil, surface
water and groundwater contamination was completed in April 1989. The
FS report, which develops and examines alternatives for remediation of
the site, was issued in draft form to the public on February 16, 1990.
The site consists of an open-sided barn, a soil containment vault, a
sump pond, three surface water ponds (designated as the Southwest
Sump, the Leachate Pond and North Pond), and an area where soil was
excavated (west and southwest of the barn) and placed in the
containment vault. The containment vault is approximately 170 ft(l) x
170 ft(w) x 35 ft (d) in size and holds roughly 38,000 cubic yards of
soil. The barn, used as the "process facility" during site operation,
contains old rusted tools, machine parts, old cans and several drums
containing unidentified waste material. This barn was formerly used
for raising hogs and was identified as the "hog barn* in previous
investigation reports; this Responsiveness Summary conforms to
previous usage of the name.
The DOPC site was operated by Mr. Earl Dubose from January 1979 to
approximately November 1981 as a waste storage, treatment, recycling,
and disposal facility. Material was transported to a site in
trailers and drums and included waste oils, petroleum refining wastes,
wood-treatment waste*, paint wastes, spent solvents, and spent
iron/steel pickle liquors. Most of the waste handling occurred in and
on the north and west side* of "process facility" that was formerly a
hog barn.
The RX/FS aasMropoeod Plan for the DOPC were released to the public
in February 1990. These documents were made available to the public
in the administrative record and in information repositories
maintained at J. M. 'Tat* High School and the Main Library at the
university of West Florida. The notice of availability was published
in the Pensacola News Journal. The public comment period was held
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from February 16 to March 16, 1990. A public meeting was held on
February 27, 1990, to present the remedial alternatives for the site.
During the meeting, EPA, FDER, and representatives from
Engineering-Science (the RI/FS consultant) presented the results of
the RI/FS. FDER presented the Proposed Plan and answered questions
about problems at the aite and the remedial alternatives under
consideration. A response to the comments received during the public
comment period is included in the Responsiveness Summary, which is
part of this ROD. A transcript of the public meeting is available for
review in the repositories.
Community Concerns
Throughout the life of this project, this has been a State lead
project. As such, no formal Community Relations Plan was developed by
the Agency. However, community relations activities were undertaken
at periodic times when activities were undertaken at the site or
milestones in the project were reached.
During the emergency removal undertaken by FDER in 1984-85, periodic
press releases were issued by FDER. Because little formal response
was seen as a result of these meetings, no formal public meetings were
held during the RI/FS. The State Project Manager (SPM) maintained
informal contact with both Mr. Dubose and with the residents who lived
within a few hundred yards of the site and had expressed concern about
the site. These residents wjere on the mailing list for the Proposed
Plan.
The PRPs' consultant, BS, developed a Community Relations Plan. As a
result of these activities, it was discovered that, during the RI/FS
process, little community interest was discovered. As such, the
following objectives for the program were developed:
o Inform area residents of Superfund process.
o Provide site-specific information concerning Dubose Oil Site.
o Provide) avenue for local citizens to express concerns they may
have About site.
o Keep local officials updated on progress at site.
Response during Public Comment Period
The public meeting to present the RI/FS and the Proposed Plan was held
at J. M. Tate High School on February 27, 1990. There were two main
issues raised at by attendees at this meeting: (1) there was a family
that lived several hundred yards downgradient from the site. Florida
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Department of Health and Rehabilitative Services (FHRS) had sampled
these their well and had found a potential problem. They were
concerned about the next step; and (2) neighbors who lived north of
the site were concerned about the long term stability of the dike
containing the North Pond.
These concerns were answered in the public meeting in this way: (1)
the FDER SPM promised follow up with FHRS to see what the results of
their testing was and to arrange for a resampling of their wells; and
(2) it was explained that, as part of the proposed remedial action,
the ponds were to be drained and filled in; therefore they would no
longer pose a threat.
Two written responses were received by the Agency during the Public
Comment Period. Concerns expressed in these letters are answered as
follows:
There tree a great deal of concern expressed about the length of time
the remedial action would take; especially in light of the) length of
time the RD/RA negotiatione and RD would take preceding the RA
implementation.
The negotiations process is mandated by SARA; including the minimum
time frames that the Agency has to allow to reach an agreement with
the PRPs. However, the Agency is committed to trying to reduce the
amount of time the RA will take by close technical scrutiny of the
Remedial Design.
Concern was expressed about the long term stability of the forth Pond
dam.
As part of the RA, the ponds will be drained and filled. During the
RD/RA implementation phase, the PRPs will be responsible for erosion
maintenance of the vault and the ponds.
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APPENDIX B
STATE CONCURRENCE LETTER
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SOUtH
Florida Department of Environnfgtft&tffftyjklat n
I' Twin Towers Office Bldg. • 26OO Blair Stone Road • gUa^sset^ gjp|||a'^399 _ ..jo
Bob Martinez. Governor Dale Twachtmann. Secreurv John shearer Assistant ^r^-.
BRANCH
May 7, 1990
Mr. Greer Tidwell
U.S. Environmental Protection
Agency, Region IV
345 Courtland Street
Atlanta, Georgia 30365
Dear Mr. Tidwell:
The Florida Department of Environmental Regulation concurs with
the recommended action for remediation at the Dubose Oil Products
Superfund Site, Cantonment, Florida. This action involves the
use of biodegradation to treat contaminated soils to levels that
are within acceptable risk levels for human health and the
environment. The action also includes 1) the draining and
filling of onsite ponds, 2) site grading and revegetation, 3)
surface water control, and 4) groundwater monitorin<
Implementation of the various components of this action will i
dependent upon detailed design results and hydrologic evaluations.
The responsible parties have formed a steering committee and have
indicated a willingness to remediate the site at their expense.
No state funds will be required.
We look forward to the successful completion of this remedial
action.
Siafcer/ly,
/Dale
Secretary
DT/Sbt
'".[
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