United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R04-90/076
March 1990
oEPA
Superfund
Record of
Zellwood Groundwater
Contamination, FL
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50272.101
REPORT DOCUMENTATION 11. REPORT NO. I ~ 3. Reclplenh AcceMion No.
PAGE EPA/ROD/R04-90/076
.. TIle end Subll.. 5. Report De"
SUPERFUND RECORD OF DECISION 03/01/90
Ze11wood Groundwater Contamination, FL
First Remedial Action 6.
(Amendment)
7. AUlhor(e) 6. Pwfonnlng Org8l\1D1i0n ~ No.
8. Pwfonnlng OrgainlDlion Name end Add.... 10. ProjectlTe8klWork Unit No.
11. ContI8C1(C) or Gt8l\t(0) No.
(C)
(0)
1~ --ortng Org8riz8llon Name end Addre.. 11 Type 01 Repor1 . Period Covered
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
Washington, D.C. 20460 1..
15. Suppl8m8nWy No...
16. Abelrect (Um/t: 200 worde)
The 57-acre Zellwood Groundwater Contamination site is approximately 1/2-mile west of
the town of Zellwood in Orange County, Florida. The site is situated in a rural area,
and approximately 300 homes located within one mile of the site depend on private wells
for their potable water supply. The site is comprised of four active industries and an
open field with marshy wetlands. Prior to 1963, the area was used by several
agriculturally related businesses. In 1963, a drum recycling facility began operations
at the site. During the drum recycling process, onsite wastewaters were generated by
draining and cleaning procedures, and two onsite evaporation/percolation ponds (n and
12) were used in the treatment and disposal of the wastewaters. A new treatment system
was installed in 1980 and use of the ponds was discontinued. In 1981, the site owners
drained the two ponds and moved some of the contaminated sediment to an offsite
landfill. The remainder of the contaminated sediment was consolidated into a temporary
sludge storage area before the sediment was moved offsite in 1982 and the onsite ponds
were filled in. In 1982, EPA identified an abandoned drum storage area by a 6-acre
field at the northern part of the site, which was apparently used for the disposal of
drums and other 'wastes. Site investigations by EPA from 1988 to 1990 identified
(See Attached Page)
t7. Document An8Iy8I8 .. DnaIpID18
Record of Decision - Zellwood Groundwater Contamination, FL
First Remedial Action (Amendment)
Contaminated Media: soil, sediment
Key Contaminants: VOCs (PCE, toluene, xylenes), other organics (PAHs, pesticides),
metals (chromium, lead)
b. IcI8nlltl8r8/Op8n-End8cI Terma
c. COSA TI FI8IdIGtoup
18. AY8II8bIIty St8t8m8nt 18. SecurIty a... (TIlle Report) 21. No. 01 Pe...
None 66
20. S8cIa1ty CIe.. (TIlle P8g8) 22. Price
IlInn",
-77)
(See ANSa-m.18)
,.. IMIrul:Ii- on R..,.-
(FOI'I1I8I'Iy NTlS-35)
Department 01 Cornrnerce
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EPA/ROD/R04-90/076
Zellwood Groundwater Contamination, FL
First Remedial Action (Amendment)
Abstract (Continued)
contamination in the soil, sediment, and ground water at the site. This Record of
Decision (ROD) addresses remediation of onsite source areas. Ground water remediation
will be addressed in a subsequent ROD. The primary contaminants of concern affecting the
soil and sediment are VOCs including PCE, toluene, and xylenes; other organics including
PAHs and pesticides; and metals including chromium and lead.
The selected remedial action for this site includes excavating approximately 3,000 cubic
yards of contaminated soil and sediment from the ditch, drum, and pond areas, followed by
onsite stabilization and solidification of the soil and sediment; replacing the
stabilized soil and sediment into the excavation area, covering the area with top soil
a~d reseeding the area; evaluating existing ground water wells for decommissioning; and
ground water monitoring. This ROD amends a 1987 ROD, which proposed treatment of
contaminated soil and sediment by incineration with disposal of the residual ash onsite.
The estimated total cost for this remedial action is $1,030,000, which includes an
estimated total O&M cost of $250,000 over 10 years.
PERFORMANCE STANDARDS OR GOALS: Soil cleanup criteria were calculated using
specific soil and climatic data from the EPA, State, and other sources.
Chemical-specific goals for soil include lead 220 mg/kg, chromium 100 mg/kg,
10 mg/kg, PCE 1 mg/kg, toluene 30 mg/kg, and total xylenes 5 mg/kg.
site
total PAHs
"
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..
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AMENDED RECORD OF DECISION
FUNDAMENTAL CHANGE
SITE NAME AND LOCATION
Zellwood Groundwater Contamination
Operable Unit .1 (OU '1)
Zellwood, Orange County, Florida
Site
STATEMENT OF PURPOSE
This document represents the rationale for an amended Record of Decision
(ROD) for the selected remedial action for this Site developed in accordance
with CERCLA, as amended by.SARA, and, to the extent practicable, the National
Contingency Plan. The amended ROD documents the significant changes in the
remedy previously proposed by the Agency.
The State of Florida has concurred in this Amendemnt to the ROD.
STATEMENT OF BASIS
The decision is based upon the administrative
Groundwater Contamination Site. The attached
which comprise the administrative record upon
remedial action is based.
record for the Zellwood
index identifies the items
which the selection of a
DESCRIPTION OF THE SELECTED REMEDY
Approximately 3,000 cubic yards of soil at the Zellwood Groundwater
Contamination Site contains elevated levels of lead, chromium, chlordane,
tetrachloroethylene, toluene, ethylbenzene, xylenes and polyaromatic
hydrocarbons (PAHS). The F10=ioa Department of Environmental Regulation has
concurred with EPA on the cleanup levels established for this remedial
alternative. The Selected Remedy consists of a source control remedy which
is consistent with an overall risk goal for this site.
"
To address the contamination at the site, the selected remedy includes the
following activities.
Activitv 1
Excavat10n-of the .011. and/or .ediment.
depicted 1ft Figure. 2 and 3:
the exi8tin9 abandoned drum areas;
former percolat10n pond '2;
abandoned drum pond;
Douglas Fertilizer Pond '1;
M1ddle Ditch South; and the
South Ditch West.
at the following locations
Verification sampling of excavated areas.
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Activitv 2
Stabilization/Solidification of the excavated aoile and sediments;
construction of a solidified monolith.
Leachability testing of solidified soils during construction of the
solidified monolith.
Placement of the stabilized/solidified soils and sediments back into the
excavated area, covering with topsoil and seeding.
Activity 3
Operation and maintenance activities required to ensure the continued
effectiveness of the remedy including:
Long term groundwater monitoring to ensure that long term
performance has been achieved with the solidification and
stabilization process. This requires additional monitor wells to
be constructed in the area of the remedy and in areas of past
disposal.
Evaluation of existing groundwater wells for decommissioning;
appropriate wells will be decommissioned in accordance with Florida
requirements.
Groundwater recovery and treatment will be addressed at a later date with a
separate Record of Decision. The scope of groundwater remediation will be
dependent on results of groundwater testing to be conducted during
implementation of the remedy set forth in this ROD for Operable Unit #1.
EXPLANATION OF FUNDAMENTAL CHANGE
Further Characterization and Results from Treatability Study Information
(Weston, 1989) developed by U.S. EPA during the Superfund Remedial Design
Process demonstrates that the selected remedy described above satisfies EPA'S
goals for source control. This change in method of source control is
significantly different than the previous ROD, 1987. The ROD, 1987 had
determined incineration of soil followed by solidification of ash to be the
proper source control method, solidification has been proven to be a viable,
effective treatment for soils and sludges at the Zellwood site at a lower
cost.
Specifically, the fundamental change in the previous remedy (ROD, 1987) and
the new selected remedy, described herein, is as follows: First,
solidification of contaminated soil and sludges at the locations described
herein will increase soil volume in the constructed remedy. This is because
incineration would reduce volume prior to solidification of ash. Second,
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solid~:ication i8 a different type of treatmen~ cri~eria. Third, the cost of
t~e selected remedy is substan~ially less than incineration and would
there:~re effectuate a quicker, cost effective treatment. This fundamental
change will produce an effective solution to contaminants present at the site
withou~ removal of hazardous constituents off site. Further, the fundamental
change meets .Applicable and Rele~ant and Appropriate Requirements at a lower
cost.
DECLA.~':'ION
The selected remedy is protective of h.~an heal~h and the environmen~,
a~~ai~s federal and state re~irements that are applicable or relevant and
appropriate, and is cost-effective. This remedy satisfies the preference for
treat~ent that reduces toxici~y, mobility, or volume as a p~incipal element.
Final~y, it is determined that ~his remedy utilizes a permanen~ solution and
alter~ative treatmen~ techno:cgy ~o ~~e max~~ extent practicable. The
expected capital cost for this remedy is approximately $780,000 with an
additional $250,000 for 12 years of operation and maintenance after the
remedial action is completed for Operable Unit One.
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Regional A~~inistratcr
.'.
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SUMMARY
of the
REMEDIAL ALTERNATIVE SELECTION
ZELLWOOD GROUNDWATER CONTAMINATION SITE
ORANGE COUN7Y, FLORIDA
Prepared by:
u.S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
ATLANTA, GEORGIA
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TABLE OF CONTENTS
1.0 INTRODUCTION 1
1.1 Executive Summary 1
1.2 Subsequent Action 2
1.3 Fundamental Change in Previous Remedy ... 2
1.4 Site Location and Description 2
1.5 Site and Regulatory History 5
1.6 Previous Site Activities 5
1.7 Regulatory Actions 9
2.0 ENFORCEMENT ANALYSIS
3.0 CURRENT SITE STATUS 10
3.1 Site Geology and Hydrogeology 10
3.2 Previous Site Investigations 11
3.3 Remedial Investigation Results 12
3.3.1 Soil Investigations 15
3.3.2 Subsurface Investigations 15
3.3.3 Discussion of Sampling Activities .... 15
3.3.4 Air Investigations 25
3.4 Routes of Transport and Potential Receptors 25
3.5 Contaminants of Concern 26
4.0 CLEANUP CRITERIA 30
4.1 Soil/Sediment Remediation . 30
5.0 ALTERNATIVE EVALUATION 31
5.1 Alternative 1 - No Action 31
5.2 Alternative 2 - Solidification/Fixation . . 33
5.3 Alternative 3 - Off-Site Disposal 33
5.4 Alternative 4 - On-Site Incineration
of Contaminated Soils 33
5.5 Comparative Analysis 34
6.0 RECOMMENDED ALTERNATIVE 34
6.1 Description of Remedy 35
6.2 Operation and Maintenance 36
6.3 Cost Estimates 36
6.4 Cost Effectiveness 36
6.5 Schedule 37
7.0 COMPLIANCE WITH OTHER ENVIRONMENTAL LAWS .... 37
8.0 COMMUNITY RELATIONS HISTORY 38
9.0 STATE INVOLVEMENT 39
Appendix A - Analytical Results, 1988 Study 40
RESPONSIVENESS SUMMARY 52
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LIST OF FIGURES
F~g~~e ~
General Site Locat~on Map
. . . . .
F~~~~e 2 - S~te Sketch
FLgure J - SOLl and Sed~ent SamplLng Locations
Figure 4 - sample Grid Pattern
. . . . . . . . .
Figure Sa - Vertical Distribution of ContAminants. .
Figure Sb - Vertical DistributLon of Contaminants. .
FLgure 6 - GeologLc Cross-Section
. . . .
FLgure 7 - Geologic Cross-Section
. . . . . . .
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4
7
14
17
19
20
21
22
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LIST OF TABLES
Table 1 - Pesticides and organics at the Zellwood
Groundwater Contamination Site
. . . .
27
Ta~~e 2 - Purgeable Organics
. . . .
. . .. .
27
Table 3 - Sample Number Soil and SedLment Samples.
28
Table 4 - Clean-Up Criteria. . . . .
. . . . . . .
30
Table 5 - Technologies Considered for Screening. .
32
Table 6 - Preliminary Cost Estimates
. . . . . . .
3S
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Amendment to the Record of Decis~on
Summary of Remed~a: Alternative selection
Zellwood Groundwater Contamination Site
Operable Unit '1
Zellwood, Florida
1.0
INTRODUCTION
1.1
EXECUTIVE SUMMARY:
Record of Decision, 1987
The Zellwood Contaminated Groundwater Site (the ~Site~) was included on
the National Priorities List (NPL) in October, 1981. In 1984, the
United States Environmental Protection Agency (EPA) Field Investigation
Team (FIT) NUS Corporation began a Remedial Investigat~on/Feas~bility
Study (RI/FS) at the site. This RI/FS was conducted to ident~fy the
types, quantities, and locations of contaminants, and to assess methods
for solving the problems presented by those contaminants. The results
of the RI/FS del~neated a var~ety of problems. These are:
Contaminated sediments located in drainage ditches, the percolation
pond, the Douglas Fert~lizer Pond and abandoned drums areas.
..
Contaminated groundwater downgradient from the Site.
..
Contaminated local irrigation wells on the Site.
After review of the Remedial Action Alternatives presented in the
Feasib~lity Study, EPA issued a Re=ord of Decis~on (ROD) in December,
1987. This RO: is included as Appendix A. The ROD recommended ~he
following actions:
..
Excavation and incineration of soils/sediments in the on-si~e
ditches, temporary sludge and two former percolation ponds, and
waste piles.
..
Appropriate leachability testing and disposal of the incinerated
soil.
..
Groundwater removal and treatment for the surficial aquifer.
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.J
1.2
SUBSEOUENT ACTION
After review of the ROD, the Florida Depar~ment of Environmental
Regulation (PDER) concluded that the remedy selected by EPA was not
substantiated by the FS. As a result, EPA and FDER agreed to re-assess
the groundwater conditions relating to the Site, to re-evaluate the risk.
assessment, and to re-assess the remedial alternatives. Subsequently,
in April 1988, EPA initiated an additional study to further evaluate the
Site conditions since the time of the RI/FS, to further investigate the
risk assessment, and to further evaluate the alcernatives for clean-up.
The analytical results of the 1988 study can be seen in Appendix A.
1.3
FUNDAMENTAL CHANGE IN PREVIOUS REMEDY
Further Characterization and Results from Treatability Study Information
(Weston, 1989) developed by U.S. EPA during the Superfund Remedial
Design Process demonstrates that the selected remedy described above
satisfies EPA'S goals/(9 criteria) for source control. This change in
method of source control is significantly different than the previous
ROD, 1987: The ROD, 1987 had determined incineration of soil followed
by solidification of ash to be the proper source control method.
Solidification has been proven to be a viable, effective treatment for
soils and sludges at the Zellwood site at a lower cost.
Specifically, the fundamental change in the previous remedy (ROD, 1987)
and the new selected remedy, described herein, is as follows: First,
solidification of contaminated soil and sludges at the locatior.s
described herein will increase soil volume in the constructed remedy.
This is because incineration would reduce volume prior to solidification
of ash. Second, solidification is a different type of treat~ent
criteria. Third, the cost of the selected remedy is substantially less
than incineration and would therefore effectuate a quicker, cost
effective treatment. This fundamental change will produce an effective
solution to contaminants present at the site without removal of
hazardous constituents off site. Further, the fundamental change meets
Applicable and Relevant and Appropriate Requirements at a lower cost.
,
1.4
"
SITE LOCATION AND DESCRIPTION
The Zellwood Groundwater Contamination Site is located in the
northwe.tern corner of Orange County, Plorida; approximately one-half'
mile we8t of the unincorporated town of Zellwood. The 57-acre Site, as
shown in 'igure One, consists of an area occupied by four industries and
an open field with a marshy wetlands area.
The Site i. .ituated in a rural area. Small r.sidential communities are
located to the north and to the east with agricultural lands to the
south and west. There are approximately 300 hom.. within a one-mile
radius of the Site. The.e homes depend on private wells for potable
water supply. In addition, Zellwood water Users, Inc. has two public
water supply wells within a half mile east of the Site servicing about
700 to 800 people. In addition to these industries and the residences,
there are .everal plant nurseries, vegetable growing operations, and
citrus groves.
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FIGURE 1
General Site Location Map
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The industrialized section of the Site has been occupied since the
1960's by Zellwin Farms Company and Drum Service Company of Florida. In
the early 1970's, Southern Liquid Fertilizer Company began its operation
on the site. The business was operated until 1981 when the plant was
purchased and operations were assumed by the Douglas Fertilizer and
Chemical Company. Douglas Fertilizer sold the property and moved its
operation to a new location in 1984. The former fertilizer production
area is now occupied by Coatings Applications and Waterproofing
Company. Chemical Systems, Incorporated, located on the western part of
the Site, commenced operations in 1982.
1.5 SITE AND REGULATORY HISTORY
LAND USE
Prior to 1963 when the Drum Service Company of Florida was established,
the area was almost entirely composed of agriculturally-related
businesses such as citrus groves, nurseries, farmland, and muck farming.
The Zellwood Groundwater Contamination Site is currently occupied by
four active businesses: Drum Service Company of Florida, Chemical
Systems of Florida, Zellwin Farms Company, and the former fertilizer
area occupied by Coatings Application and Waterproofing Company. In
addition, several other businesses are located in the industrial area
surrounding the Site. Adjacent to the Zellwin Farms facility there is a
migrant worker hotel.
Approximately one-half tr.ile north of the Site are several residential
developments and the Willow Street Community Center. The majority of
residences north of the Site and the Willow Street Community Center have
been established since 1965. Adjacent to the Site on the south side are
muck farms. The remaining areas surrounding the Site are composed of
citrus groves and pastureland. A main traffic artery, U.S. Highway 441,
is located less than one-half mile east of the Site.
Land use in a one-mile radius of the Site can be divided into five major
categories. Agriculture, primarily muck farms and citrus groves,
accounts for 74 percent of the area land use. Residential use totals 10
percent, followed by commercial, industrial, and transportation areas
occupying 9 percent. Seven percent of the land area is combined lake
and wetland areas.
1.6 PREVIOUS SIT1 ACTIVITIES
Drum Service Company of Florida, a drum recycling facility, began
operations in 1963. In the course of recycling used drums, wastewaters
were generated through the draining and cleaning procedures. From 1963
until 1975, the Company used two on-site evaporation/percolation ponds
for treatment and disposal of the wastewater. In 1980, the Company
redesigned its treatment system, eliminating the use of the ponds for
waste disposal. These ponds, former percolation ponds II and 12, are
depicted in Figures 2 and 3.
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FIGURE 2
Site Sketch
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Drainage and removal of contaminated sediments from the two ponds was
initiated in August 1981. The sediments were collected and initially
disposed of in the Astatula Landfill in Lake County, Florida. After
August 21, 1981, the landfill operators changed their policy and refused
to accept the wastes because the sediments had been generated in another
county. To complete the clean-up of the two ponds, Drum Service Company
of Florida constructed a temporary eludge storage area consisting of an
earthen berm at the western edge of the drum storage area. The sludge
was subsequently removed from the temporary storage area during October
and November 1982, and hauled to the Brevard County Shredder Landfill.
The areas where the ponds had been located were filled in and are
presently used for parking and drum storage.
Douglas Fertilizer and Chemical Company and the previous business,
Southern Liquid Fertilizer, had three unlined surface impoundments which
received wastewater from their production process. The company is no
longer at this location and, as of 1985, water remained in only the
easternmost pond.
Chemical Systems, Inc., located northwest of the Drum Service Company of
Florida, is a small facility producing cleaning products for the citrus
concentrate industry. This company reportedly does not generate either
solid or liquid wastes.
The Zellwin Farms Company facility is a vegetable washing and packing
plant. From 1960 to 1983, all waters from the vegetable washing processes
were discharged to the southern ditch which parallels Jones Avenue. In
1983, water from the carrot and radish cooling process and the run-off
from the Zellwin Farms parking lot area north of the Jones Avenue facility
were diverted to a drainage ditch south of Jones Avenue. The remainder of
the water is still discharged to the southern ditch which parallels Jones
Avenue.
In December 1982, EPA representative8 discovered an abandoned drum storage
area located on an approximately six-acre field north of the northern
ditch and south of the Seaboard Coastline Railroad in the northern section
of the zetlwood Groundwater Contamination Site. The abandoned drum area
was apparently u8ed for the di8poeal of drums and other wastes. Based on
unsubstantiated reports from residents in the area, some of the material
may have been there for more than 20 years.
The Zellwood Site was listed on the first final National Priorities List
which wa. publi8hed in the Federal Register in 1983. In the fall of 1983,
EPA'8 Re;ion IV Emergency Re8ponse and Control Section (ERCS) over8aw a
Potential Re.ponsible Party (PRP) removal action at the abandoned drum
area of the Site. In 1984, a Remedial Action Ka8ter Plan was developed
and a Work Plan for the RI/FS was formulated. Negotiations with the PRPs
were initiated, but the PRPs did not implement the EPA Work Plan. EPA,
using its FIT, implemented the RI/FS in 1985. The Site was resampled in
June 1988 to confirm levels of contamination in both water and soil.
-8-
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'JIATORy ACTIONS
Between 1963 and 1971, Drum Service Company of Florida operated its
wastewater disposal system without a regulatory permit. In 1971, Drum
Service Company of Florida applied for and was granted Florida Department
of Environmental Regulation (FDER) Operation Permit No. IC-1308. The
permit was granted for a wastewater treatment system using evaporation and
percolation ponds for treatment and disposal of wastes from the plant. In
1975, the system was redesigned to eliminate ponds except for temporary
storage of wastewater. FDER issued Operation Permit No. ""S48-2077 for
this system on July 31, 1975. In 1980, further design cr. .-.ges were made
eliminating use of the ponds for storage of wastewater. As of 1985, Drum
Service Company of Florida held FDER Permit No. AO48-27470B to operate a
drum reclamation furnace for processing used drums by burning and melting
the interior residue, and subsequent coating of interior and exterior drum
surfaces.
The Douglas Fertilizer Chemical Company and the Zellwin Farm Company have
not, in the past or currently, held any industrial waste treatment
permits. Chemical Systems, Inc., reportedly did not generate either solid
waste or wastewater, and thus would not have a permit.
In March 1986, the Florida Department of Environmental Regulation filed
suit against the Drum Service Company for failure to comply with
applicable air regulations. In May 1989, both the PRP and FDER reached a
joint agreement for dismissal of the suit.
2.0 ENFORCEMENT ANALYSIS
Four businesses currently operate at the Zellwood Groundwater
Contamination Site. The Drum Service Company recycles used steel drums.
The drums are recycled by incinerating liquids and residuals that are
present in the drums at a minimum temperature of 1600*F, followed by
cooling, straightening, and repainting. Wastewater is generated by the
draining and cleaning of the drums prior to incineration. Oil is
separated from the wastewater by an oil separator. Recovered oil is
stored in a 5,000 gallon tank until it is sold to an oil reclaimer. Prior
to November 1980, effluent from the wastewater treatment system was
discharged into two evaporation/percolation ponds. Presently all effluent
is reportedly recirculated through a closed loop system and used as
conveyor chain cooling water in the incinerator system.
Drum Service company of Florida currently leases the business property
from NAPA Inc. NAPA also owns the property which housed the abandoned
drum area. NAPA Inc. funded the emergency removal that was supervised by
EPA in 1983. NAPA hired Drum Service as the contractor for the emergency
removal project.
Drum Service participated in negotiations to implement the RI/FS Work
Plan. The company ultimately declined to -mplement the EPA RI/FS Work
Plan. Drum Service did submit an RI/FS Work Plan of their own; however,
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EPA did not accept that Work Plan as being technically equivalent to the
EPA Work Plan. EPA then offered to split the Work Plan into surface and
subsurface portions; thus, allowing any interested parties to perform at
least part of the RI/FS with EPA performing the rest. This offer was
declined. Drum Service has been cooperative in allowing EPA site access
for the investigative work and has followed EPA activities at the Site.
Drum Service has recently (May 1989) indicated their renewed interest in
participating in the RD/RA activities associated with source remediation
presented herein. Negotiations are being pursued at this time.
Douglas Fertilizer, which operated on the Zellwood Site from the mid 1970s
to 1984, has relocated to another piece of property in Zellwood, Florida.
According to FDER, the company currently operating on the old Douglas
Fertilizer Company property, Coatings Applications and Waterproofing
Company, does not require any environmental permits.
Chemical Systems Inc., leases the property it occupies from Drum Service
Company. It also does not discharge any wastewater and thus requires no
permit. Chemical Systems has been in business at this Site since 1982.
Seaboard Railroad, which owns the railroad right-of-way on the Site, was
notified that they were a PRP during the negotiations. The company showed
no interest in implementing the project.
3.0 CURRENT SITE STATUS
3.1 SITE GEOLOGY AND HYDROGEOLOGY
The Zellwood Site is underlain by an unconfined surficial aquifer and the
artesian Floridan aquifer. Regionally, the water level ranges from
immediately below ground surface to greater than twenty feet below ground
surface. The shallow aquifer fluctuates in response to climatic recharge
and discharge mechanisms. Seasonal fluctuation of up to ten feet are not
uncommon. At the Site, the hydraulic gradient ranges from 0.35 to 0.63
feet per 100 feet, which is somewhat steeper than is regionally normal.
This mayxbe due to continuous pumping of surface water out of the muck
farm area directly south of the Site. The general direction of flow is to
the south-southwest.
Between th« surficial and Floridan aquifers is the Hawthorne Formation.
In the area, the Hawthorne consists of a green to yellowish-green clay
which is underlain by a brown to white dolomite or dolomitic limestone. A
clay-like sand layer in the upper Hawthorne retards the vertical movement
of water between the surficial aquifer and the limestone of the Floridan.
The dolomites and limestones of the lower Hawthorne may be considered to
be hydraulically part of the Floridan aquifer. The Floridan is the major
source of potable water for people living near the Zellwood Site.
Regional potentiometric surface maps indicate a northeasterly direction of
groundwater flow in the Floridan aquifer. The water level measurements
taken in the Floridan aquifer wells at the Site in May, June, and
-10-
-------
September 1985, were plotted and contoured. Examination of this data
confirms a divergency from the normal northeasterly flow and suggests that
water level* »t the Site are not representative for the determination of a
regional flow direction in the Floridan aquifer. The anomalies of the
potentlometric surface of the Floridan aquifer could be an effect of
numerous factors including a structural depression at the top of the
Floridan Formation, local pumpage of municipal and industrial wells, and
localized flow patterns within the solution channels of the Floridan
aquifer. Also, one of the three deep monitor wells was set in a solution
channel immediately below the Hawthorne Formation while the other two were
set in the limestone of the Floridan Aquifer.
3.2 PREVIOUS SITE INVESTIGATIONS
Numerous investigative .ctivities have taken place at the Zellwood
Groundwater Contaminat >n Site since 1980. Following are a few of the
more significant activities:
' The FDER collected wastewater samples from two ponds on Drum Service
Company of Florida in July 1980. Several heavy metals were
identified in the samples.
In April 1981, the FDER analyses of groundwater samples collected
from temporary monitor wells on Drum Service Company and downgradient
of Southern Liquid Fertilizer indicated the presence of several
contaminants. A sample collected from a well located between a pond
on Drum Service Company and the large pond on Southern Liquid
Fertilizer showed the presence of arsenic and other contaminants. A
surface water sample was also collected from the large pond on
Southern Liquid Fertilizer.
In November 1981, Drum Service Company of Florida retained Seabury
and Bottorf Associates, Inc. to conduct a soil and water sampling
investigation along the right-of-way of the Seaboard Coastline
Railroad. Samples were collected from three locations along the
railroad and analyzed for residual arsenic. Arsenic concentrations
ranging from 5.89 milligrams per kilogram (mg/kg) to 5.96 mg/kg were
found in the soil at each of the three locations.
Geophysical studies conducted by the FDER in 1981 and the EPA Field
Investigation Team (FIT) contractor, Ecology fc Environment, Inc.,
(Ml) in April and July 1982, indicated the presence of possible
grooadweter contamination plumes on the south side of both Drum
Service Company and Douglas Fertilizer Company.
* During July and August 1982, FIT (ES.E) conducted a sampling
investigation and installed six groundwater monitor wells in three
locations. Surface water and sediment, soil, and groundwater samples
were collected for analysis. However, much of the data was unusable
because of Quality Assurance reasons.
-11-
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The EPA Environmental Services Division (ESD) conducted a hazardous
waste site field investiga~ion during December 1962. Several metals
and organic compounds were detected in the soil/sediment and water
samples. Cadmium and lead were found in two potable water wells.
'.
The ESD resampled two private wells in April 1983. The two metals of
concern, cadmium and lead, were not detected in either sample.
These were the investigations that took place prior to the initiation of
the 1984 FIT Remedial Investigation and Feasibility Study.
In June 1988, EPA resampled all private and industrial wells and soils on
the Site. The two primary metals of concern that were detected were lead
and chromium.
3.3
REMEDIAL INVESTIGATION RESULTS
Previous studies at the Zellwood Groundwater Contamination Site indicated
several major concerns. The combined factors of the shallow water table
and the known waste disposal/treatment practices led to the public health
concern of groundwater contamination. Another concern is the transport of
contaminants off-site via the drainage ditches since these ditches have
historically been collection points for run-off of contaminated surface
water and soil. A third concern is the potential public health threat
that may exist from contaminant migration and direct contact with on-site
contaminants or waste, or both.
Groundwater quality in both the surficial and Floridan aquifers and the
other potentia: contamination migration routes were investigated during
the RI. The investigation included a subsurface boring program,
insta:lation of 17 monitor wells, groundwater sampling and analysis, and
data evaluation.
Surface water and sediment samples were also collected from ditches within
the stud~ area. The result. were compared with previou8 study re.ults to
assess ch~nge8 in water quality and sediment contaminant levels. The
contaminants found in the .urface water and sediment .amples were
evaluated to identify .ource areas. The analytical results of the
sampling inve.tigation. for 1982, 1985, and 1988 have been compiled in
tabular form in Appendix A. A dra.tic change in contaminant
concentration. can be .een by reviewing the data. The changes could be
attributed to the pump well. nearby as well as many other factors. The
pump rate. are approximately 125 million gallons per month in the dry
.eason and 1.3 billion gallons per month in the wet ..ason. This could
eventually draw .lug. of contamination accro.. the area at varying rates
and be observed in a random sampling.
The waste areas at the Site were identified using historic aerial
photographs and geophysical techniques. Surface and subsurface soil
samples were collected from the.e areas to evaluate the potential for
contaminants to migrate to groundwater. The results of the analyses were
also used to estimate the vertical extent of contamination.
-12-
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FIGURE 3
Soil and Sediment Sampling Locations
-13-
-------
\
k>
ir¥
-*•
I'I Ri :OI AFION
POfJIl /111
._ I —II
( 12)
cnu-v
ij.r. I'OND'.,
D Inf
POND |2
L.-'
n
son
SLUIMENT SAMPLi: LOCAIIONS
LI t;i rju
f 'jAMI'Ll Silt:
-------
3.3.1
SOILS INVESTIGATION
In June 1988, as part of addit~onal RIfFS work, post 1987 ROD, EPA
conducted a thorough resamp~ing of the Site to determ~ne contam~nant
levels and migrat~on patterns.
Soil samples were collected in several designated areas of the Site
~ncluding the fQllow~ng areas: l} abandoned drum area; 2} former Drum
Service percolat~on ponds; 3) temporary sludge storage area; 4} railroad
r~ght-of-way; and 5) current Drum Service area. The so~l sampling
locations are depicted in Figure 3.
3.3.2 SUBSURFACE INVESTIGATION
Test Bor~nq Proqr~~
As part of the June 1988 investigation, a test boring program was
instituted at the Zellwood Groundwater Contamination Site to further
characterize the Site geologically and to determine intervals for well
screens prior to well ~nstallation. A test borehole was advanced at each
of the seven monitor well locations. Except for location number two, all
test borings were advanced 200 feet or to the top of the Floridan aquifer,
wh~chever was less. The confining Hawthorne Formation was not penetrated
at location number two because of the suspected high levels of
contam~nat~on ~n th~s area.
During the June 1988 study, geologic information generated during the RI
was examined to further characterize the Site. Well logs were used to
develop cross sections to illustrate the geology On and around the S~te.
Figures 5(a) and 5(b) show the locations of cross sections. These figures
also show fence d~agrams for the Site developed using wells logs from all
test boring locat~ons.
3.3.3
DrscussrON OF JUNE 1988 SAMPLING ACTIVITIES
This sampling activity was comprised of multimedia sampling. All soil,
sediment, and groundwater samples were collected in accordance with the
1986 EPA Reg~on IV - Engineering Support Branch Standard operating
Procedures and Quality Assurance Manual, referred to as the SOP.
Twenty-.ix percent of the total specific .ite .ample. were split with the
PRP, a. reque.ted by the PRP. Surveying of .oil and groundwater sampling
location. va. conducted by the EPA Emergency Re.pon.e Team {ERT}, Edison,
New JerNly.
The Zellwood Site was divided into five .oil and .ediment sampling
area. to confirm .oil contamination level..
1.
Abandoned Drum Area
A sample grid pattern 100' x 100'
in Figure 4. Each grid point was
was u.ed in this area depicted
surveyed. The grid pattern
-15-
-------
FIGURE 4
sample Grid Pattern
,
-16-
-------
,.-
- - -==- - - ....-
: --:::- - .-
1--- -------- ~ ----
I I ~ ~~ - -'"':......... - - .
I I ~- - - ,;
! '-'- 1- . I'
I '" --- --
I ..: J.. -=--:=..------ - - - 5
/
I
I
I
I ' /
r i " I
~'
~ r I
,\ I
D f'e!
I '<' I
C ii'~ , I
I: '''',)
" ¥,,' .
t---
I \ ~...'i .
'I \ v' ,
:3 I \ ~)
, Il "
:-;T~. :- '
I :~.. --: ,
J-.. ',<.....
,,,-,
." .
.........
.........
.
.
---
--
i :
, 1
"'I"
1
2
: \
I \
I I
uV
'5
5'
FIGURE 4.
SAMPLE GRID PATTE~~
4
-17-
"
E
-------
FIGURE SA AND S8
Vertical Distribution of Contaminants
-18-
-------
A
100
90
80 7~58
70
60 ,~ "0 ~
50
40 .n 140 Cr
-..~
30
20
'0
1 10
0
. -10
-20
-30
....
24'T )) Cr
20~
FI~lIrp ')<1.
VfRTlCAL DISTRIBUTION OF CONTAMINANTS
) W'58
.10
A'
10(
!)(
YWP) 2 5A/"
'\" ~ ,....
12
,~ 14 ,..
1.10 C, f)
20 )10.... I~OO L,
10 CN
11"" J1
4] C, 10 U4
))
711 ""
~::J
II~ ~- ~..~
8'
A
I
18
L. -
rp
" c, T
'4"" I)'
- - - -~~
..
2
-2
-)
5EPA
v <' r tlc;11 0 1st r i h II t i () 11 () f C" 11 t 1111 i 1\ IIII ~;
-----,
-------
8
100
9
80 8 SAt-
WIP-4
70 nn c;, nc;,
8 .ISO" 8 2. "
80 eN 1001
60
110 c;,
50 ...
10CH
S] 340 C,
40 UPb
30
I
,.J 20
c.:>
I
10
0
. -10
-20
-30
VERTICAL DISTRIBUTION OF CONTAMINANTS
NP-2
8
8.1 Pb 8
/'
IW-8
U Ph
IOn C,
I~O l'b
~~
8'
I" 0 Cr
27f1 Pb
A
~
- - - ..h.....
..
Flgure 5b.
Vt'rtical Oisl rihul ion of COllI amilla. ion
I SA"
21 . 21 Pb
50
IJO C,
2~ ....
G'
100
90
80
70
60
50
40
30
20
10
o
-10
-20
-30
-------
A A'
100 10(
90 ~(
8(
70- 7(
60 f)(
50 - :)(
40 4(
30 3(
I 20 2(
f'J
....
I 10
-10
-20
-30 .
LEGEND
FIGlIHE 6.
~ SAND
~ SIlTY SAND
~ C~Y£Y SAND
~ SAHDYC~Y
~ SANOy C~Y Wlni PHOSPHAT[
erol OGIC (r~o~=~ - ~)rc riCH'!
/ IJ I woo [) N I ) L ~; III
S EPA
------
WATfR TABLE
------
ItAWTIIORN[ r IJR~TlON
CONIALI
NOrF vlRflCAl [XA(,I.t RAIION ~ 10 R~
-- 1 (
-2(
-3(
-------
{
100
C)O /
/
Rn
10
f,Q.
~)O-
40
30-
I 20-
,)
"
I 10-
0
. -10
-20-
-30-
r
.- Inn
:}O
RO
In
(;()
~ I (J
'to
,',n
." .
)n
10 -
o
- -.
- .
--10 :
"1- .
~... ~-
--)0
-. - --,7.0
l.tC[NU
- - -. . . ..
w" Inl r Afll F.
FIClIH\': 7.
GL 0\ OCIC CROSS - Sl _C rIO~J
/1 I.LWOOD NI t. ~~In:
f!r!I SAND
~ SILTY SAND
r.-;.-:j f-IAYfY ~ANO
L .~ SANDY CLAY
~ SANOY CI.M WIn! Pltn~.I'II"lr
------
I t"W II ,nf/tlt lOR""" liON
cnN I"". I
NOlL VIRIWAI rxAr.r.1 RABON = 10.8'1(
8 EPA
...--.-- .
.-___'.+0
- - .
------- --
- .
--. -.----
----
-- ..--- - u..
--------
-------
was four columns wide and five rows h~gh. Row A of the actual
grid patter~ was placed in the approxLmate position of Row B ~n
the sampling plan. Row F cou:d not be placed in the drum area,
therefore, it was elLminated. The pond in the drum area fell
out.ide of the gr~d pattern, and the entire pattern was t~lted,
northeast to southwest approximately 20..
2.
Sludoe Storaoe Area
One compo8~te sample wa. collected per cell from five distinct
sample points. sample depth wa. .ix to 12 inches for two
rea.ons. First, the .ludge .torage area i. now located in a
fairly high traffic area. Therefore, .urface .oils would not be
representative. In addition, over the la.t five year. the
surface soils have been .craped occa.ionally by the site
operator.
3.
Existi~Q Ponds
There are currently four ponds on-site. SedLment samples com-
pos~ted from five distinct points were collected from each pond
or pond section.
a.
Douolas Fertilizer Ponds
Dur~ng the years that Douglas Fertilizer was in operation,
wastewater from fertilizer formulation. was di.charged into
three unlined ponds. One composite sample was collected
from the dry pond at a depth of zero to .ix inches.
Samples were sent to Contract Laboratory Program (CLP) for
a full Target Compound List (TCL) scan, and split w~th ERT
for screening of metal. and cyanide (CN). The larger
Douglas Fertilizer pond i. below the water table and always
contains water. Due to its size, the pond was divided into
two sections. Each section had one composite .ediment
sample. Sample. were .ent to the CLP laboratory for a full
TCL .can and to ERT for screening of pe.ticides.
During an investigation of the Dougla. Fertilizer property,
a 8tained area was found. It wa. sampled, labeled DFP-O,
and screened for pesticide. by ERT.
b.
Abandoned Drum Area Pond
The pond was sampled as one composite sediment sample.
The sample was .ent to the CLP laboratory for a full TCL
scan, and split with ERT for screening of metals and CN.
4.
Former Percolation Ponds
The two percolation ponds used by Drum Service. Company were
excavated and backfilled in 1982. aecause of this, sampl.. were
collected at a depth below thr.. feet. Each pond was divided
into two sections with one composite sample collected per
-23-
-------
~.
section. Each of the five distinct points per composite sample
were measured from the survey points and laid out in a random
pattern. All four samples were sent to CLP for a full TCL scan,
split with ERT for a full TCL scan and three samples were split
with the PRP.
Ditches
a. North Ditch
Grab samples were collected at 200' intervals along the
north ditch in the area of highest contamination as indi-
cated in the 1985 sampling data. The first sampling loca-
tion (ND-l) was placed 200' from the north-middle ditch
intersection. All samples were sent to ERT for screening
analysis of metals and CN. The two grab samples directly
below the abandoned drum area (ND-4 and ND-5) were split
and sent to the CLP laboratory for a full TCL scan.
b.
Middle Ditches
There were two sections to the middle ditches. The first
section was from the north-middle ditch intersection to the
culvert under the railroad tracKs. In this area, grab
samples were collected every 100' for a total of six
samples. The sample closest to the north-middle ditch
intersection and on each side of the railroad tracks were
sent to CLP for a full TCL analysis. All six samples were
sent to ERT for screening of metals and CN.
The second section was from the culvert past the railroad
tracks to the middle of Drum Services. Grab samples were
collected every 200' for a total of five samples. Samples
MDS-l, and MDS-3 through MDS-5 were sent to CLP for a full
TCL scan and all five samples were sent to ERT for screen-
ing of metals and CN.
c.
South Ditch
From the 1985 sampling data, only one area had contami-
nation of any significance in the south ditch. Therefore,
only two grab samples were collected, one on each side of
the ditch between Douglas Fertilizer and Drum Services.
Both .amples were sent to CLP for a full TCL 8Can and
.creened by ERT for a full TCL.
,
d.
Zellwin Ditches
Grab .ampl.. were to be collected in the approximate loca-
tion. a. th08e collected in 1985. Two .amples were
collected, east and west of the Zellwin Farms discharge
ditch. Sample ZFD-2 was sent to CLP for a full scan and
screened through ERT for pesticide..
-24-
-------
e.
Tank Farm Dit=h
There was a small ditch that ran from the Drum Services
Company tank farm to the north ditch. Since the Site lnVes-
tlgation conducted on Hay 17, 1988, the ditch was converted
to a culvert. Secause of this, one sample was collected
at the mouth of the culvert at the north ditch, 18 inches
deep. The sample was sent to CLP and ERT for a full TCL
scan.
f.
DouqlAS Fertilizer Ditch
Th~s ditch runs between the old Douglas Fertilizer Company
and Drum Services. Two grab samples were collected from
this ditch and DFD-l was sent to the CLP laboratory. Bot~
samples were sent to !RT for a TCL scan.
3.3.4
A:R INVES~!GATION
No air samples were collected for analysis during the RI. However, under
normal conditions, it is unlikely that particulate or volat~le
contaminants will present much of a threat to the nearby res~dents or
workers. However, strong winds, heavy equipment operation, or continuous
truck traffic within the Site could expose contaminated surface soils to
airborne transport. Remedial activities are expected to consist of
removing th~s exposure pathway through solidification of the contaminated
soils. Poss~ble dust control will be implemented at the S~te during the
remedial activities if airborne particulate increa.e.. The extent of the
exposure to the various chemicals via inhalation of contaminated dust from
wind erosion is not anticipated to be significant. This exposure would
occur only during t~es of heavy truck traffic within the drum storage
areas. EPA toxicologists have evaluated this pathway and determ~ned that,
during so~l excavat~on activities, air mon~toring will be requlred for
personnel protection.
3.4
ROUTES OF TRANSPORT AND POTENTIAL RECEPTORS
Surface Water and Sediment/Soil
Surface water feature. at the Site include .everal ponds and three distinc-
tive drainaqe pathways referred to as the northern, middle, and southern
ditche.. Surface water run-off at the Site i. either confined in the
pond. or L8 channeled to one of the ditches. Although Site drainage is to
the west and ultimately to the south toward the muck farms and Lake
Apopka, the data from the RI showed little migration of surface water
contaminants off-site. Unless there has been a heavy incidence of rain,
the northern and middle ditches are usually fairly dry and contain only
isolated area. of stagnant water. The 80uthern ditch contain. a fairly
constant flow of water, since it receives a direct discharge and run-off
from the Zellwin Farms large paved parking lot.
-25-
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3.5
CONTAMINANTS or CONCERN
One of the June, 1966 sampling activity goals was to determine the level
of contaminants present in soil and groundwater. The predominant contami-
nants found were lead, chromium and PAHs. There is only one area of the
site in which a different subset of chemicals was selected for
evaluation. This different subset can be found in Table 2. This subset
was developed using the "i~dicator chemical" process found in the
Superfund Public Health Evaluation Manual (draft December 17, 1965, EPA).
The sole purpose of the list was to evaluate the risk to public health
that would remain if no remedial action was taken. The only place this
list is utilized is in Section V of this ROD.
~.
-26-
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nBLB
1
Pesticides & organics
at the
Zellwood Groundwater Contamination Site
ME':'A.:.S
Arsenic
EXTRACTABLE ORGANICS
Napthalene
Cadmium
Acenaphthylene
Chromium
Fluorene
Lead
Phenanthrene
Cyanl.de
Anthracene
PES':'ICIDES
Dieldr:..r.
Pyrene
Benzyl Butly phthlate
4'4' DDE
Drysene
4'4' DD:::
Benzo Flouranthene
Ga.rrur.a Chlordane
Benzo-A Pyrene
Alpha Chlordane
Ideno-Pyrene
Benzo-Perylene
nBLB
2
PURGEABLE ORGANICS
Tetrachloroethane
Toluene
Ethyl Benzene
Total Xylene
-27-
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nBLB 3
SAMPLE NUMBER
SOI~ AND SEDIMENT SAMPLES
June 1988
Abandoned Drum Area
ADS-Al-l Grid Al, 0" - 6"
ADS-Al-2 Grid Al, 6" - 18"
ADS-A2-1 Grid A2, 0" - 6"
ADS-A2-2 Grid A2, 6" - 18"
ADS-A3-1 Grid A3, 0" - 6"
ADS-A3-2 Grid A3, 6" - 18"
ADS-A4-1 Grid A4, 0" - 6"
ADS-A4-2 Grid A4, 6" - 18"
ADS-81-1 Grid 81, 0" - 6"
ADS-Bl-2 Grid 81, 6" - 18"
ADS-82-1 Grid 82, 0" - 6"
ADS-B2-2 Grid B2, 6" - 18"
ADS-B3-1 Grid B3, 0" - 6"
ADS-83-2 Grid 83, 6" - 18"
ADS-B4-1 Grid B4, 0" - 6"
ADS-B4-2 Grid 84, 6" - 18"
ADS-Cl-1 Grid Cl, 0" - 6"
ADS-Cl-2 Grid Cl, 6" - 18"
ADS-C2-1 Grid C~, 0" - 6"
ADS-C2-2 Grid C2, 6" - 18"
ADS-C3-1 Grid C3, 0" - 6"
ADS-C3-2 Grid C3, 6" - 18"
ADS-C4-1 Grid C4, 0" - 6"
ADS-C4-2 Grid C4, 6" - 18"
ADS-Dl-l Gric1 D1, 0" - 6"
ADS-Dl-2 Grid Dl, 6" - 18"
ADS-D2-1 Grid D2, 0" - 6"
ADS-D2-2" ' Grid D2, 6" 18"
-
ADS-D3-1 Grid D3, 0" - 6"
ADS-D3-2 Grid D3, 6" - 18"
ADS-D4-1 Gric1 D4, 0" - 6"
ADS-D4-2 Grid D4, 6" - 18"
ADS-El-l Grid El, 0" - 6"
ADS-El-2 Grid 11, 6" - 18"
ADS-!2-1 Grid 12, 0" - 6"
ADS-12-2 Grid E2, 6" - 18"
ADS-13-1 Grid 13, 0" - 6"
ADS-13-2 Grid E3, 6" - 18"
ADS-14-1 Grid 14, 0" - 6"
ADS-14-2 Grid 14, 6" - 18"
ADS-IS-l Grid 15, 0" - 6"
ADS-IS-2 Grid ES, 6" - 18"
TSA-l Temporary Sludge Storage - Grid, 1
TSA-2 Temporary Sludge Storage - Gric1 2
-28-
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TABLB 3 (Cont'd.)
SAMPLE NUMBER
SOIL AND SEDIMENT SAMPLES
June 1988
DFP-l-l
DFP-2-1
DFP-3-1
DFP-3-2
Ponds
Abandoned Drum Area
Former Percolation Pond tl - Grid 1
Former Percolation Pond tl - Grid 2
Former Percolation pond '2 - Grid 1
Former Percolatl.on pond '2 - Grl.d 2
Douglas Fertilizer Pond tl 0" - 6"
Douglas Fertilizer Pond .2 0" - 6"
Douglas Fertilizer pond '3 Grid 1
Douglas Fertilizer Pond ,3 Grid 2
ADP
FPP-1-Cl
FPP-l-C2
FPP-2-Cl
FPP-2-C2
Ditches
N:J-1
ND-2
ND-3
N:J-4
ND-S
ND-6
N:J-'7
North
North
North
North
North
North
North
Ditch
Ditch
Ditch
Ditch
Ditch
Ditch
Ditch
(north-middle
Sample '2
sample .3
Sample t4
Sample .5
sample '6
Sample '7
intersection)
/00-1
MD-2
MD-3
MD-4
MD-S
MD-6
MDS-l
MDS-2
MDS-3
MDS-4
MDS-5
Middle Dl.~ch
Middle Ditch
Middle Ditch
Middle Ditch
Middle Ditch
Middle Ditch
Middle-South
Middle-South
Middle-South
Middle-South
Middle-South
(north-middle intersection)
Sample '2
Sample .3
sample '4
Sample '5
Sample '6
Ditch sample tl
Ditch Sample '2
Ditch Sample .3
Ditch Sample '4
Ditch Sample '5
SDE-l
SDW-l
South Ditch East Sample
South Ditch West Sample
ZFD-l
ZFD-2
Zellwin Farm Ditch '1
Zellwin Farm Ditch '2
TFN
Tank Farm North Sample 6" - 18"
DFD-1
DFD-2
DFP-O
Douglas Fertilizer Ditch sample '1
Douglas Fertilizer Ditch sample '2
Douglas Fertilizer Debris Area
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4.0
CLEAN-UP CRITERIA
Based on calculations using site specific soil and climatic data and data
from the Soil Conservation Service, the University of Florida, and the US
EPA Environmental Research Laboratories, mathematical models, and best
professional judgment, EPA determined the clean-up levels for the Zellwood
Groundwater Contamination Site. Site wide clean-up levels are designated
below:
Table 4
Clean-Up Criteria
~
Abandoned Drum Pond
Contaminant
Lead
Chromium
Chlordane
Total PAHs
Concentration
220 mg/kg
100 mg/kg
7 mg/kg
10 mg/kg
Abandoned Drum Storage Area
and Former perc Pond '2
Tetrachloroethylene
Toluene
Ethyl Benzene
Total Xylenes
1 mg/kg
30 mg/kg
38 mg/kg
5 mg/kg
Middle Ditch South
Lead
Chromium
Chlordane
220 mg/kg
100 mg/kg
7 mg/kg.
The total PAH's referred to are extractable organics and the total xylenes
refer to the ortho, meta and para xylenes. These levels were selected by
inputting climatic and soil data into the Pesticide Root Zone MOdel (PRZM)
with consideration of the E.P. Toxicity data from the site. The model was
calibrated to reproduce the average yearly water budget. This model
ranked fifteen (15) chemicals found at the Site based on the potential to
contaminate groundwater. Upon initiation of the remedial action at the
Site, If ~PA determines through the excavation efforts that the levels for
cleanup'.,are not attainable or approachable these levels will be
reconsidered by both the State of Florida and EPA.
4.1
SOIL/SEDIMENT REMEDIATION
The remedial action 8elected will consist of removing the contaminated
80il. from the Site. Stabilization/Solidification of th08e .oil. will be
conducted in a .uitable area, large enough to contain the completed
monolith and allow for workers to operate equipment and perform the
nece..ary activitie8 to mitigate the problema at this Site. There will be
approximately 3,000 cubic yards of 80il to be remediated. DU8t control
measures will be anticipated in the event of increa.ed particulate into
the atm08phere in the area of excavation and .olidification. Treatability
.tudies have been conducted to in.ure the mixture. of fixation agents will
prevent the contaminants from leaching into the groundwater. Confirmation
sampling will be conducted after excavation of the 80ils to ensure all
contaminants have been removed from the Site; testing during construction
will verify the success of the remedy.
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5.0
ALTERN~TIVES EVALUATION
The purpose of the Operable Unit One remedial action at the Zellwood
Groundwater contamination Site is to mitigate and m~n~~ze contamination
~n the soils, sediments, surface and groundwater, and to reduce current
and future potential risks to human health and the environment. Based on
the level of contaminants found at the site, the endangerment assessment
and regulatory requirements, the following clean-up objectives were
determined:
To protect the public health and environment from
contaminated soils or sedDnents and water through
ingestion and direct contact.
exposure to
inhalation,
To prevent the spread of contaminants in the groundwater, surface
water and so~ls.
To reduce or prevent contamination of groundwater.
Clean-up goals were developed for the contaminated soil at the Zellwood
Groundwater contamination Site based on applicable or relevant and
appropriate requirements (ARARs) of federal and state statutes or other
regulations (Table 5-1). The goals were developed to prevent potent~al
groundwater contamination from exceeding ARARs and to reduce potential
cancer risk from inhalat~on.
An initial screening of possible technologies was performed to identify
those technologies which best meet the criteria of Section 300.68 of the
Nat~onal Contingency Plan (NCP). Following the initial screening of
technolog~es, potential remedial action alternatives were identified and
analyzed. These alternatives were screened and those which best satisfied
the clean-up objectives, while also being cost-effective and technically
feasible, were developed further.
Table 5.2 summarizes the results of the screening proce... Each of the
remaining alternatives for soil and sediment remediation were evaluated
based on cost, technical feasibility, institutional requirements, and
degree of protection of publiC health and the environment.
5.1
AL TERNATIV8 11
NO ACTION
The ri.k ......ment conducted as part Qf the remedial inve.tigation showed
that no act10n is not protective of human health from the Site conditions
presently ex1sting. contaminant toxicity is not reduced in the absence of
treatment. No action does not provide permanent source control, and does
not satisfy a preference for treatment.
This alternative is required to be considered by the NCP and is
to provide a base-level action against which other alternatives
compared.
presented
may be
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TABLE
5
TECHNOLOGIES CONSIDERED FOR SCREENING
ZELLWOOD GROUNDWATER CONTAMINATION SITE
ZELLWOOD, ORANGE COUNTY, FLORIDA
Eliminated (E)*
Technology
Retained
(R)
1.
No Action
E
Not protective to human health or
the environment.
2.
Solidification/Fixation
R
Adsorption
E
Not Applicable due to waste
characteristics.
Lime Addition
R
Clay Addition
R
3.
Off-site Disposal at
RCRA permitted facility
E
Not applicable due
characteristics;
Landfill and EPA
this activity.
to waste
State of FI"
policy restricts
4 .
On-site Incineration
E
Metals cannot be incinerated;
solidification of ash still needed
resulting in additional costs; not
appropriate or cost effective due
to the minimal quantities of
organics present within the waste
stream.
"
'.
*If Eliminated, .e..on for Doing So.
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5.2
ALTERNATIVE 2:
SOLIDIFICATION/FIXATION
A silicate/cement-based stabillzation process has been selected for
evaluation of the solldificatlon/fixation of soils at the Zellwood
Groundwater Contamination Site. The8e methods have the ability to
stabilize materials containing high concentrations of heavy metals, even
under acidic condition8. M08t proces8es us. two inorganic chemical
reagents WhiCh react with polyvalent metal ions to fo~ a chemically and
mechanically stable solid. The process is based on reactions between
soluble silicates and silicate setting agents under controlled conditions
to produce a solid matrix. Reagents commonly used include sodium
silicate, fly ash, kiln dust, and Portland cement (as the setting agent).
The resulting matrix is clay-like and displays properties of high
stability, low permeability, high alkalinity, high bearing strength, and
high cation exchange capacity. The resulting solid can be easily and
economically handled, transported and stored. The volwme added to the
waste by the treatment process would be between 5 and 10 percent. A
vegetative cover will be constructed over the 801idified waste.
This alternatlve is considered innovative for metals; but experimental for
organic compounds. During excavation and mixing of approximately 3,000
cublc yards of Boil, some volatilization of organics will occur;
leachability testing for verification and groundwater wel18 near the
solldified monolith will monitor for any leaching of organic compounds.
Estlmated Capital Cost:
$780,000 includes monitor wells
$250,000 operation and maintenance
5.3
A:.TER.'\A:I'J:: 3:
OFF-SITE DISPOSAL
T~ls alternatlve requires the excavation of all contaminated 80il and the
disposal of the waste in an off-site RCRA permitted facility.
Approximately 3,000 cubic yards of contaminated soil would be excavated.
This soil would be placed in a pile near the excavated area and allowed to
drain prior to loading into trucks. Water would drain from the soil into
the excavated area. The upper six inches of the excavated area would be
backfilled with topsoil and vegetated. Florida Landfill restrictions
prohibits this activity. Soils would have to go out of state. EPA policy
prefers on-site, permanent remedies as opposed to off-site landfilling.
Estimated Capital Cost:
$1. 12M
5.4
ALTERNATIVE 4:
ON-SITE INCINERATION OF CONTAMINATED SOILS
It is estimated that it will take approximately (one) 1 year to incinerate
approximately 3,000 cubic yards of on-site highly contaminated soils at
about 1.75 tons per hour.
The lack of organic contamination in large quantity at the Site prevents
this technology from being a viable alternative. The major contaminants
-33-
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remaining within the soil are metals and few pesticides. In addition,
there is a lack of readily available permitted mobile incinerators
nationwide. There may be a considerable delay between the design of an
incineration system and the set-up of an incinerator on-site. As
indicated, this is not a feasible alternative due to the high metals
concentration and "minimal organic concentration. The ash from the
incinerator would have to undergo treatment to bind the metals in the soil
before the disposal of the ash making incineration a non-viable solution
for the remedy.
Estimated Capital Cost:
Sl.75M plus cost of additional treatment for ash
5.5
COMPARATIVE ANALYSIS
This analysis will compare the alternatives presented in an evaluation of
performance to the statutory criteria. On-site incineration and.
solidification/fixation will be compared due to the other two alternatives
failing the threshold criteria.
Overall protection of human health and the environment: and compliance
with apPlicable or relevant and appropriate reauirements
Both of the alternatives accomplish these criteria. Incineration
requires compliance with a larger range of ARAR's than does
solidification thus increasing the task of monitoring activities as
well as technology challenges using incineration.
Lona-term effectiveness and performance: reduction of toxicity. mobility.
or volume throuah treatment: short-term effectiveness: implementabilitv;
and cost
Solidification is the leading alternative here. Incineration
actually would not address the reduction in toxicity or mobility of
contaminants at the site due to the remaining contaminants consisting
largely of metals with minimal to no organic ,concentration.
Treatment of the ash from the incineration unit would be required to
address the remaining metals contamination. Both alternatives would
giv~.the same effectiveness both long and short-term since both
alternatives require solidification of the soils from the site.
Solidification is much more implementable and cost effective than the
incineration alternative by almost halt the cost.
State/8uDDOrt aaencv acceptance: and communitv acceptance
SOlidification receives more support and acceptance than
initiating an incineration project within a local agricultural area.
The burning of contaminants into the atmosphere has never been easily
accepted by the public or many states, whereas solidification with
monitoring of the area is more acceptable.
6.0
RECOMMENDED ALTERNATIVE
The recommended alternative for remediation of soil and sediment
contamination at the Zellwood Groundwater Contamination Site includes
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solidification and stabilization and backfilling of treated material on
the Site. During the March, 1989 Treatability Study, d~fferent m~xtures
were analyzed for leachabil~ty of organics, pesticides and metals. A m~x
can be chosen fom that analysis that does not leach above drinking water
standards into the groundwater. Therefore, solidification and
stab~lization of the contaminated soil provides a viable remedy for the
Zellwood Site.
6.1
DESCRIPTION OF RECOMMENDED REMEDY
Contaminated soil will be treated using stabilization/solidification
methods. Following treatment, the stabilized and solidified soil/sedUnent
will be placed back into the excavated area, covered with approxUnately
six inches of top soil and s.eded to provide vegetative cover. At
selected intervals, during excavation, soil sample. will be collected and
analyzed to determ~ne the lUnits of excavations. Excavation will cont~nue
~n des~gnated areas until clean-up goals are reached.
TABLE
6
PRELIMINARY COST ESTIMATES
ZELLWOOD GROUNDWATER CONTAMINATION SITE
ZELLWOOD, ORANGE COUNTY, FLORIDA
EstUnated EstUnated EstUnated
Construction O&M Total
Cost Cost Cost
Technology
Sol~dH ~catior. S 780,000 S250,OOO Sl,030,OO:
/Fixation
Incinerat~on 51,746,240 S250,OOO S1,996,240
Off-Site Disposal at S1,117,370 -0- S1,117,370
RCRA Facility
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This recommended alternative meets the requirements of the National Oil
and Hazardou8 Substances Contingency Plan (NCP)" 40 CFR, 300.68(j) and the
Superfund Amendments and Reauthorization Act of 1986 (SARA). This
alternative permanently and significantly reduces the mobility of
hazardous contaminants in the soil and the sediment8 in the lagoons and
ditches. Another activity planned for Operable Unit One, groundwater
evaluation, will determin~,the requirements for this remedy.
The alternative is cost-effective when compared with other applicable
alternatives. The technology has been innovative and experimental,
although the studies indicate the alternative i8 implementable at the
Site. It is estimated that this alternative could be implemented within
twelve months. Alternatives 2 and 4 would require from one to twelve
additional months for implementation.
6.2
OPERATION AND MAIN~ENANCE
Long-term operation and maintenance requirements are expected for the
alternative for this operable unit. Monitoring will determine the
effectiveness of the alternative at reducing migration of
inorganics/organics to the groundwater. At this time, it is anticipated
that five well clusters of three wells each will be installed. Each of
these wells would be sampled on a quarterly basis for the first two years
after the construction of the remedy is completed, and semi-annually
thereafter for a minimum 10 years. At the end of 12 years, the Agency, in
coordination with FCER, may evaluate conditions and determine the sampling
regime needed. Samples will be analyzed for the Target Compound List
metals, cyanide, PARs, volatiles and pesticides.
6.3
COST EST!MATE
Solidification/stabilization is expected to have a total estimated capital
cost of approximately $1.03 million. This estimate assumes a cost of $120
per ton'(of,solidification/stabilization, with the inclusion of other
,
related costs for construction bringing the construction costs to
approximately $780,000. Monitoring cost is $75,000 each year for the
first two years after implementation and $10,000 for each succeeding year
for an additional 10 years.
6.4
COST E,nCTIVENESS
This alternative affords a higher degree of overall effectiveness in not
only protecting the public against direct exposure but in removing the
threat of future relea.e of contaminants. The estimated capital cost of
this alternative is $1.03 million (including operation and maintenance).
This remedy is a practical remedy which can be implemented year-round.
Operable Unit One, by providing source control and groundwater monitoring,
will allow an opportunity to implement anticipated activities in Operable
Unit Two which will address contamination of groundwater on-site.
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6.5
SCHEDULE
This planned schedule
Contam~nation Site is
september, 1989
September, 1989
January, 1990
June 1990
for remedial activities at the Zellwood Groundwater
as follows:
Amend December 11, 1987, ROD
Complete RD
Complete Monolith
Complete Installation of Monitor Wells
7.0
COMPLIANCE WITH OTHER ENVIRONMENTAL LAWS
Section l2l(d)(2)(A) of CERCLA incorporates into law the CERCLA Compliance
Policy, which specifies that Superfund remedial actions meet any Federal
standards, requ~rements, criteria, or limitations that are determined to
be legally applicable or relevant and appropriate requirements (ARARs).
Also included is the provision that State ARARs must be met if they are
more str~ngent than Federal re~~irements.
The requirements of the National Environmental Protection Act (NEPA) have
been met. Additionally, the results of these studies are being presented
to the public through a public notice, and the public has been given the
opportu~~ty to comment on the results of the studies and the proposed plan
for the remedial action.
. Occupational Safetv and Health Administration
(OSHA)
A health and safety plan will be developed during remedial design and will
be followed during field activities to assure that regulations of OSHA are
followed.
. Safe Drinkinq Wa~e~ Act
(SDWA)
Additional groundwater studies will be conducted during Operable Unit
One. A feasibility study to determine the appropriate clean-up
alternat~ve will include measures to ensure conformance with the SDWA.
Any discharge will be below the drinking water standard..
. National Pollutant Discharoe Elimination System
INPDESI
The cho.en alternative does not include any di.charge., therefore this
requirement 408. not apply.
. Clean Water Act
Soil remediation is aimed at source control, and implementation of the
recommended alternative would result in an end to potential contamination
of surface water.
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Resource Conservation and Recoverv Act
(RCRA)
The requirements of the Resource Conservation and Recovery Act (RCRA)
are applicable to RCRA characterized or listed hazardous wastes (40
CFR Part 261) which were disposed at a site after November 19, 1980.
Examples of RCRA requirements include minimum technology standards,
monitoring requirements, and storage and disposal prohibitions. No
Federal or State contaminant-specific ARAR has been identified for
PAH-contaminated soils. The levels for pesticides, metals and
volatiles onsite have been obtained through groundwater modeling and
acceptance by EPA and the State of Florida Department of
Environmental Regulation. Land Disposal Restrictions (LDRs) are,
however, applicable to remediation of contaminated soils., The LDRs
are applicable to the waste on-site if the soils are excavated and
removed or excavated and treated. In alternatives where the LDRs are
applicable, the soil must be treated to the interim treatment levels
prior to land disposal.
Although the recommended remedy for soil/sediment contamination is
not regulated under RCRA, in some instances, it may be considered
~treatment~ of hazardous waste. However, this action is treatment of
hazardous substances under CERCLA, not hazardous waste. Therefore,
LDR does not apply. Nevertheless, all sOlidification/stabilization
activities will take place within a confined corrective action
management unit (CAMU), and RCRA land disposal-type requirements will
be substantially met.
Florida Department of Environmental Reaulation (DER)
Compliance ~ith othe: environmental laws (17-701 FAC Solid Waste for
monolith cap) includes the cap cover and monitoring of the monolith.
The cap over the solidified mass will consist of a minimum of six to
ten inches of topsoil with seeding to initiate a vegetative cover.
The monitoring wells will be installed to monitor the water quality
around, the monolith as well a8 monitor the monolith for a period of
twel~e years to ensure that the metals are not leaching into the
groundwater.
8.0
COMMUNITY RELATIONS HISTORY
The following community relations activities were performed at the
Zellwood Groundwater contamination Site:
A ract Sheet on the Site was prepared in November 1986.
A community Relations Plan was developed and implemented.
-38-
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An information repository was established in January 1987, at:
Zellwood Community Center - 6565 Willow St., Zellwood, FL
Zellwood Elementary School - East Washington St., Zellwood, FL
A pres. release providing an opportunity
~nformation on the open~ng of the public
issued August, 1989.
for a public meeting and
comment period has been
Public notices providing the same information will run in the
and evening editions of the Orlando Sentinel, a daily paper
determined to be the most widely read in the area.
morning
9.0
STATE INVOLVEMENT
As required by CERCLA, Section 104(C), the State must assure payment of
ten percent of all costs of remedial act~on if performed by EPA. Remedial
action has been defined in SARA as including all construction and
Lmpl.mentat~on activities until site remediation is completed. Activitie.
required to maintain the effectiveness of the remedy following completion
of the remed~al action is considered operation and maintenance (O~). The
State is requ~red to pay 100 percent of all O~ following completion of
the remedial action. EPA and the State may enter into an agreement
whereby EPA would fund 90\ of O&M costs for a period not to exceed one
year, until the remedy is determined to be operational and functional.
The State of Florida has been consulted on the selection of this remedy.
The State has concurred with the selected remedy.
-39-
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APPENDIX A
SOIL ANALYTICAL DATA
FROM MARCH, 1988
METALS AND CYANIDE
PESTICIDES
EXTRACTABLE ORGANICS
PURGEABLE ORGANICS
,
-40-
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ARS[IIIC 1:1.1'111 1111 cmu"I"" 1.111.0 CUll"."
u. STArIlIll UU 1988 1 '111\ 19118 IVII\ 1988 198' 1988 1985 1981
/ /
1:1., AI-I 6.'11 16. n8 J 190.00 J 1000.00 J 11.00 J
.:I, AI'2 1.'0 II 1.'0 .J 800 . 00 .J U.OII II 1.10
1:1 r A1 I '.60 I.hll J ".00 .J )60.011 J ).60 .I
1:1.1' 0\1..1 0.1111 1. III .I J8 .UII .1
1:11' AI I 11.1111 I I'U 6\1 1
1.1.1' U'l I. III 11.011 .I \\ Ulf .. 2.00 J
nl' "6 I 2.1111 ).21\ .1 16.UU .I
1:11' A6 1
u.r ",1 7.60 1.911 .I 160.00 J 610.00 J 16.00 ./
1:1.1' II'l 0.89 1.111 J U.OO J 110. 00 J 1.20 J
1:11' 12- I 7.110 1.'" J 16.00 .1 210.00 J '.)0 J
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1:11' 1),2 1.'0 J U.OII J I .lU .I t~
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I CI.I' 16-1 1;1:.
",. n.1' CI-I 6.'0 160.00 .I 1'00.00 J U.OO .I t I :)
'"
I CI.I' CI-I ).)0 II 0 . 00 I.U J 100.00 .J ".00 .J 1.10 .I I'
CI.I' Cl-I H.OO J 110.00 J 2.60 J ~~ f:
CI.' C7-1 '.60 J 1.00.1 ~\!
CI.I' C)- I U.OO J .1.00 J 'J .,
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CI., C6-1 1.20 J
CI.' C6-1 I. '0 J 100.00 J 1.10 J 1.00
[/IT 01-1 1'.10 108.00 19\.00 1.)0
£IT 01-1 11.10
UT 01-1 '1.00 1.10
ElT 07-' 100.00 J 1.20 I. \0
un 0)-1 I. 10 ). '0
[liT 0'-1
£IT D6-1 '.60 I. 10
[liT D6-' '.00
[IT II-I 1'.60 n.811
UlT II-I 2.20
UT U-I ).10
laT U-2 '.60 1.90
t:M, [J-I I. )0
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III' U-I I .2U
1.11' U-2 18 80
_-,ooftf01('...
UNn lit PI'''
C\ P - COKIRACf I Aft PROCRA&.I
IH"'IIoIIHOIHCY Itl ~Ot.:I[ II""
II ac ...-CAIf' ntll' OAf A UHUSNI f.
J. 151!UII'W VAllI[
8. 1981 AttAi YlICAI 011111
-------
AII51.1I11; LAillIlUH UIAO"IIIII ItAIl L'(AIIIP[
tAl STAT ION 1911~ I~IIII 191\', 1988 19111 I~II" I ~"\ 1 'I"" I~"\ I'IRR
eLP TSA-I ".00 . II '0 1 11n 011 . 6 M) ' I\UII 011 .
CI.P '5"'1 h UII , 711 uu I
I;IP AlIP '.60 1 ,,, " 1111 I 1000 00 J 2~O uo .I 0 ~II I
u, trp- I-CI 1 00 1 10 . 1 '" I 1 IJU . , 40 .I /I I ~ .
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(;I.P DIP - , -, , 10 11 00 200.00 11 II.. I IOU 011 U 011 J 1 II) I
(;1.' O"I-J 26.00 110 un I '''0 IHI .I 6 10 J
CI.' II'P-'-I 61 00 1.10 160.00 III 00 I 60.00 I III I 0 01 I
elP PIP l-J 1 ", 16 un I 11 Uti .I
ClP DIP 1-8 1. 00 ).1U '. 20 " 110 1 II 110 '1 011 J
Cl' Otp-\-, I 10 .I 20 /lU .I
lIlT III. 8 '.20 I 90 \ '0 100.00 / 110 2110 00 11 10 I un
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UT 1111 1 10 00 1 /11 \0.60 10011 110 I' 10
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CI.' 1111- 1 II \U I 61 011 J "I
UT 1111 6 80.00 69.00 7UO 011 II 10 I
I UT 1111 ' 11 00 II '"
~. ClP 1111 8 ) 60 " 00 J 210 1111 .I
L.
I UT ItIJ 2 , 00 16 00 160 00 ,., f'
lilT HI! 1 1.'0 1 60 " 00 220 00 I 10 0 )0
UT HI! 6 / .0
CI' .., 1 2.60 , 10 I " 00 66.00 J
CI.P Hli 6 . 60 J /.IU J 0 U "
, I
CIP ",S , 1.'0 10 on 9 /U J
£IT HI" - 2 8.10 '90 10 1111 11 111 ) 40
Ct.P I8IS-l 1 111 II III .I 1\ 011 ,
CLP HlIS-6 1 00 .I 1.60 61 nit I 160 no I
CI., HlIS-' '1.00 .I IU 110 .1 J9" uu J 7 '0 /
eLP 50[-1 , 00 1 60 " 00 29 '111 .I 110 00 1111 IIU J 1 411
el.p SOU, 9.00 , III 61 00 UII Uti I 1911 011 2111 1111 I
ClP IfU-' . 110 I
CL' nil 2 6 70 1 uu J
CLF 1111 1 00 / 16 00 I
el' 11111 I 20 00 , . ~II 1 19 00 J
(liT UfU 2 2 In I' 11/ 4ft 10
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"tllI~ "' 1'1'101
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-------
PESTICIDES
"
-44-
-------
01[11.11111 ',"11111 '."VDO (;AHA CIII"~DAHR AI riiA .111 OP"AHI
IAI n AT 11111 "I~ 1911 19ft' 19111 19ft' 1981 I~'" I~IIII I (IH ") ..""
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'.'1' AI 1 100 00 1100 uo '" 011 }IIU ou I I/U 00 I
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RESPONSIVENESS SUMMARY
This summary presents all of the Agency's responses to relevant comments
received from the interested public and potentially responsible parties (PRPS)
for the Zellwood Groundwater Contamination Site in Zellwood, Florida.
. .
A.
OVERVIEW
The alternative chosen in the original ROD involved the incineration of onsite
soils to remove the organics and metals from the site. The amended ROD
requires solidification/stabilization of the soils on-site to prevent the
organic and metal contamination from leaching into the surrounding area,
mitigating the threat to the environment and public. While the original ROD
addressed both groundwater and soil remediation. The amended ROD addresses
only soil contamination. Groundwater will be addressed specifically at a later
date after the results of the soil remediation are analyzed and reviewed. The
bifurca~ion of this action is being taken in response to the Florida Department
of Environmental Regulation.s (FDER) concerns regarding the Floridian Aquifer.
The general community, did not provide any comments on the proposed remedy for
the amended ROD. Comments were received from the attorneys for two of the
PRPs. This responsiveness summary will forcus on the comments from the
attorney for Drum Service. The comments received from the attorney for Douglas
Fertilizer were not related to the selection of a remedy and are therefore not
adressed here.
The responsiveness summary is divided into the following sections:
Background on community Involvement.
Summary of Comments Received during the Public Comment Perioe and
Agency Responses.
Remaining Concerns.
B.
BACKGROUND ON COMMUNITY INVOLVEMENT
Community int~rest in the Zellwood Groundwater Site has been very limited
dating back to September 29, 1986 when EPA held a public meeting at the
Zellwood Elementary School. Four letters were received by EPA following the
public meeting, three from interested citizens and one from a PRP. Following
the meeting, .,A set up repositories at the Zel!wood Elementary School and at
EPA Regional Office. in Atlanta, Georgia. The minutes of the public meeting
have been placed 1n the Administrative Record at both repositories. The
administrative record at the repositories have been updated when new relevant
information has become available. On September 5, 1989 EPA issued a public
notice in The Orlando Sentinel informing the public of the fundamental change
to the December 1987 Record of Decision. Fact sheets were sent to all
interested parties, PRPs, local media and officials. EPA received
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or.e response to the release, that being from the attorney for Drum Service, one
of the PRPs. Based on a comment from one of the PRPs, EPA discovered that the
~nformat~on previously placed in the repository at the Zellwood Elementary
School was m~B.ing. As a result, EPA replaced these materials and began
updating the information that had prev~ously been put into the Administrative
Record and EPA Library for the Zellwood Groundwater Contamination Site.
c.
SL~Y OF COMMENTS RECEIVED DURING PUBLIC COMMENT PERIOD AND AGENCY
RESPONSES
EPA mailed the Notice of Fundamental Change Fact Sheet to all interested
part~es on September 29, 1989. EPA received two responses, one from the
Attorney for Drum Service Company of Florida, one from the Attorney for
Douglass Fert~lizer. As noted above, this summary will focus only on the
comments from the Drum Service Attorney. Their comments were broken down into
several categories and this response w~ll follow the S4me format. A summary of
the comments and EPA's response to those comments is set out below.
1.
Public Record Deficiencies.
The PRP commented on the lack of new information at the repository set up in
the Zellwood Elementary School and the fact that the proposed amended ROD was
not ava~lable for review before the end of the 10 day public comment period.
Claims were made by the PRP's tha~ the materials they felt were necessary for
review and reference were not made available to them at the Zellwood Elementary
School Rep06~tory, although these materials were apparently received from the
Florida DER and EPA by the PRP. The PRP also claimed the 10 day public comment
period was unreasonable considering the extent of the changes and
inaccessibility of certain materials.
E?A Response: Since the public meeting in 1986, EPA has maintained an
Administrat~ve Record in Repositories at the Zellwood Elementary School in
Zellwood, Florida and the EPA Region IV offices in Atlanta, Georgia. Both
Repositories are updated as necessary with additional information. Recently,
September 22, 1989, information supporting the changes in the ROD was Sent to
both places.
The Agency recognizes that one purpose of the repositories is to provide
interested parties with sufficient relevant information supporting Agency's
choice of a remedy such that they may comment on the proposed remediation
technique. As noted in Section B above, EPA discovered that materials that had
been placed in the Zellwood Elementary School Repository had been removed by
unknown parti... Upon discovery, the missing documents were replaced with
copies from the Atlanta Repository. Aa a result, all of the items that were
intended to be in the Zellwood Repository may not have been placed there betore
the release of the public notice. However, the informAtion was replaced on
September 29, 1989 and was always available in the Atlanta Repository and
through the Florida DER. Further, EPA had mailed the Notice of Fundamental
Change and Fact Sheet to all interested groups and individuals in OCtober,
1989. This notice referred the recipient. to contact persons at EPA if more
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information was needed. As noted, many of the documents were available to the
public from the Florida DER under the Sunshine Law which requires the release
of all requested documents and information with the exception of certain
proprie~ary information. Based on the comments in the PRPs letter, it appears
~he PRP ~ook advantage of this source. Thus, although the information was not
immediately available at the Zellwood Elementary School, all the necessary,
relevant information was available through EPA in Atlan~a and other sources.
Further, it is important to note that every document in the Agency's files need
not be included in the Administrative Record in the repository files. In
addition to being the official record of the Site, one purpose of the
Administrative Record is to provide information supporting the Agency's
decision concerning the remedial alternative chosen for the ROD. This would
allow an interested party an opportunity to review and comment on the ROD. The
PRP noted that several documents that were referenced in the Florida State
agency files were not included in the record. However, the memorandums
indicated in the October 15, 1989 letter from the PRPs were not all pertinent
to the decision making process. Memorandums 1, 3, and 4 were not considered in
the decision process while memorandum 2 was used to determine the soil clean-up
levels protective of a Class II Ground Water. Although the levels represented
in memorandum 4 were modified to allow for the lead and chromium levels to be
higher based on the fact that the leachate concentrations of lead and chromium
in soil would not lead to groundwater contamination above drinking water
standards at the concentrations listed in the amended ROD. The PRP also
commented that a copy of the amended ROD was not available for review. At that
point, the amended ROD was in draft form. As such, it is a predecisional
document and not available for review. However, the Fact Sheet sent out with
the Notice of Fundamental Change described the changes that were being
considered for the amendec ROD. Also, based on the comments in his letter, the
PRP had apparently received a copy of the draft Amended ROD as well as the
materials he discussed in his letter from the Florida DER under the Sunshine
La\.;.
The PRP's last comment under this heading addressed the length of the 10 day
comment period set for responses to the changes presented in the Amended ROD.
The primary difference between the original ROD and the Amended ROD is the
choice of the ,remedy for the Site. The information and facts presented are the
same for both documents. Since the changes to the ROD were not extensive and
interested parties had .ufficient relevant information to review and comment on
these changes, it is the EPA'. opinion that a 10 day comment period was
adequate to addre.. the change. and not arbitrary and capricious a. .ugge.ted
by the PRP.
2.
Endangerment- Aa.e.ament
The PRP aeked if there had been a formal reevaluation of the endangerment
a..e..ment and if .0, was the evaluation reflected in written document.
EPA Response: The endangerment as.e..ment for this site was not formally
reevaluated. Of cour.e, the information contained in this document was
reviewed during the decision making process. This review would not constitute
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an implicit reevaluation of the endangerment assessment. EPA will not
reevaluate the original endangerment assessment unless the concentrations
reported during Operable Unit II justify a reevaluation of the endangerment
assessment. In the event that a reevaluation is conducted, the document will
be sent to the repository. The endangerment assessment, if reevaluated, will
not be sent to the PRPs for comment.
The PRP wanted to know if EPA baaed its new remediation alternative on the same
risk and endangerment assessment which previously led EPA to conclude that
incineration was the proper remedy.
EPA Response; EPA did not conclude based on the endangerment assessment alone
that the remedy was to be incineration; many other factors and information were
taken into consideration to form a conclusion as to the proper remedy. As
mentioned before, the population affected by the contamination, the environment
affected, migration pathway and the contaminants present are all considered
along with the endangerment assessment.
At the time of remedy selection, the best available alternative was
incineration for the quantity of organic and pesticide contamination reported
to be present at the site. Although, the soil concentrations of organics at
this time are lower than those previously reported, the metals contamination
from the Site remains the same, therefore thus using the previous endangerment
assessment for the soils is appropriate. This is not to say that the organic
concentrations are low enough to justify reducing the remedy to no action or
off site land disposal. The leachability of the contaminants into the
surrounding areas and groundwater remain to be a major concern.
3. Remedy Selection
The PRP inquired into how EPA determined the clean-up levels/goals for the site
set out in the notice and summary of the Amended ROD.
EPA Response: The clean up goals chosen are not arbitrary, but are based on
research and review of available information concerning the specific site and
meet the requirements of the NCP. EPA utilized many sources of information in
order to determine the clean-up goals for the site. This included the analysis
of soils and groundwater from the lite, use of the groundwater models available
to EPA, the PRZM model and the leachability tests used to characterize the area
and understand the relationship between the aquifer and the prevention of the
contamination from entering the water table. This information was compiled and
reviewed to determine the clean-up goals for the site, both to be protective of
human health and the environment on a long-term basis. In summary, these
levels in no way can be specified as arbitrary and capricious as the PRP has
stated in their cooroents.
The PRP also questioned the use of the PRZM model in EPAs estimation of a
clean-up goal for the site.
-55-
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EPA Response: The PRP has questioned the use of the PRZM model. At the same
time, the other concerns expressed seem to state that they have no information
as to how the model was applied. It is difficult to understand how the PRP's
technical consultants are able to reach the conclusion that the model was
misapplied and at the same time state that they have no information as to how
it was applied in this specific instance. The PRZM was used to evaluate the
ability of pesticides to leach into the groundwater. In addition this
information was used by the Ground-Water Technology Unit in their derivation of
soil remediation goals.
We recognize that the site-specific pesticides are likely to be highly adsorbed
to the organic material in the site soils; our derivation ,of these soil
remediation goals took into account the partitioning behavior of the pesticide8
based upon their solubility and the octanol/water partitioning characteristics
of theee compounds. What must be recognized here is that no matter how
strongly the pesticides may be adsorbed to the 80il, there will always be some
portion of the adsorbed mass which will partition into the ground water. Given
that the appropriate ground-water protection standards for these contaminants
are set at very low concentrations, the result is that the soil concentrations
protective of ground water are correspondingly low. It is correct that the
PRZM was not used to derive soil remediation goals for metals on the site.
This would be inappropriate, in our view. The metals criteria were derived
from an examination of soil quality data from the borings and the corresponding
ground-water quality data from the same boring locations.
The PRP also expressed that EPA improperly eliminated Alternative 3, off-site
disposal as the appropriate remediation method for the site.
EPA ReSDonse: CERCLA, as amended by SARA, Section 121 (b)(l) and (d)(2)(A),
(3\ and (4) set out the relevant Federal requirements related to the Zellwood
proposed plan. After review of the alternative, the Agency has determined that
an on-site remedial action is preferred over an off-site remedy. Off-site
disposal would be acceptable only if on-site treatment is not feasible, which
is not the case for Zellwood. Further, offsite disposal of the contaminated
materials from a CERCLA site must be placed in a facility that fully meets the
requirements of RCRA which in this case would render this option cost
prohibitive.',"
',~
The PRP has questioned the permanance of the remedy chosen in that past EPA
SITE reports consider the alternative Rexperimental for organic compoundsR and
"innovative for metalsR.
EPA Response, The remediation alternative hae been analyzed in the laboratory
with extensive leachate tests on the soil for both organics and metals. The
results prove ~e remedy chosen will mitiqate the posibility of organics and
metals contamination entering the surrounding groundwater above the drinking
water standards .et by the State of Plorida. Therefore the alternative meets
Agency requirements in that the environment and public are being protected.
Solidification of the contaminated soils on site is the best available
technology to be implemented at the Site at this time. Transportation of the
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wastes to a landfill for disposal does not conform to the permanent remedy
solution in that the problem is being transferred to a different location with
the potential to contribute to a larger problem in the future. EPA as well as
the industry realizes that in the future technology will advance to a level
capable of addressing the problems that are faced by the present environmental
community in a more cost effective and efficient manner. As stated earlier the
alternative chosen is the best available technology for the Bite at this time
and delaying the remediation would not be in the best interest for all
involved.
The PRP raised a question as to how the level of clean-up could be chosen
before the groundwater was addressed.
EPA Response: The clean-up levels chosen are protective of the groundwater.
In this case, the source of the contamination has b««n the focus of Operable
Unit #1 in which soil removal will mitigate the contamination from continuing
to be released into the groundwater. Which in turn initiates groundwater
remediation. With the removal of the source of contamination the groundwater
contaminant concentration will decrease. Goundwater clean-up will then be
addressed in further detail during Operable Unit 12.
4. Clean-up Goals.
The PRP claims that the specific clean-up goals set for the Site were
arbitrary, caprcious and unreasonable.
EPA Response: The PRP based this claim on the arguments that other clean-up
guidelines are lower; the average of the data for certain metals at this Site
are less than the clean-up goal; rain may have caused isolated areas of
contamination affecting the samples that were taken from the drum disposal
area; based on the comparison of soil composite lead EP toxicity extract data
levels found in other materials, the removed materials should be placed in a
solid waste landfill; and other sites and RODa for drum handlers have had
stringent clean-up standards.
As discussed in the response to the PRP concerns with the remedy selection, the
clean-up levels set for the Site were based on a review of site specific
information, general information as well as appropriate models. All of this
information is taken into consideration when the clean-up goals are set. As
such, the goals set were not arbitrary, capricious nor unreasonable as alleged
by the PRP. Further, the goals were set in accordance with the provisions of
CERCLA. In support of their allegation, the PRP suggested that although there
were high levels of lead, other values of lead were lower and in a range
acceptable in other situations. The PRP then refers to standards set in
several other countries and in a 1986 EPA study. The fact is that sone of the
data represents samples taken from areas that may have had low levels of
contamination. However, there were also unacceptable, high levels of lead (as
well as other metals and substances) present at the Site.
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This argument ia similar to the PRPe next comment concerning the use of average
value's in place of absolute values of the data for certain metals in
determining the claan-up goals. The use of an average of all samples taken at
the Site is clearly not appropriate or relevant in setting clean-up goals.
Wher a large number of samples are examined, averaging the data can mask the
higher (as well as lower) values. The purpose of the soil investigation was to
define the areas of contamination that will require remediation. This would
result in sampling data from areas that had low or no contamination. Averaging
the data serves no purpose in this type of investigation. In sum, the fact
that the average value, site wide for a certain parameter, may fall below the
remedial goal is not relevant.
The PRP also suggested that the 1983 samples from the drum disposal area may
have been inaccurate due to rain causing isolated bits of contamination to be
mixed in the surface soil and mud. A review of all of the Site data taken over
time does not support this contention. The data clearly indicates the presence
of these contaminants at high levels supporting the need for the remediation.
Further, based on this argument, overtime the flushing action of the rainfall
and/or the volatilization of the soils caused by heat should result in lower
levels of contamination which is not the case at this Site.
The PRP's next comment suggests that based on the results of the analysis of
the EP Toxicity extract from a soil composite sample, lower lead clean-up
standards would be appropriate. However, a soil composite sample ia not
reflective of the absolute levels of contamination at the Site. Actually, it
is an average of the samples that make up the composite sample. Further, in
this case, the sample tested was a solidified treated sample, not raw soil
rendering this comparison irrelevent.
The PRP next compares the level of contamination found at other drum handling
facilities that did not require clean-up and suggests that the proposed levels
may be more demanding than levels the EPA has proposed in other Florida drum
handlers RODa. Further, the PRP complained that the period of time set for
public comment did not allow sufficient time for comparison of the other
Florida drum site RODs to the remedy chosed for this Site. In either case, it
is important to remember that many site specific factors such as location,
population, public access, contaminants present, effects to public drinking
water, number of private drinking water wells in area, migration pathways of
contaminants, ate. are considered when remedies are chosen and clean-up levels
are set for a specific sit* (or determining if clean-up is necessary).
Abstract comparison of remedies or contaminant levels found at similar
industries is inappropriate.
5. Miscellaneous.
The PRP mentions that they have made significant and enormous changes to the
plants and businessess over the past IS years to prevent further pollution of
the environment. The PRP stated that EPA has neglected to account for this in
the contaminant levels dropping at the site.
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EPA Re.pOn.e: EPA recognizes the advancemen'C t.hod :?~Ps hc:.ve mCtde J(j the manner
in wh1.ch they handle the1.r wastas and ol1vir.-u& growth the PRPii have eX}?erienced
over the years; but in no way does thi3 account for the red~ct;.on of waste
contamination. The PRPs are bec~ml.ng ~ware o~ t~e aer~~uc li~ility l.nvolved
l.n releas1.ng wa8te into the enV1.ronment A~d taking pre~autions to prever.~ any
further releases. However. the advancemept and modificatione to the blJ91.ne8SeS
does not remedia~e th~ cont~.i~atio~ previously releasad by any i~dustry or
business nor does Lt rel~nqui6h the companies from their re.ponsibilicj' for
remediation of t.he sit",. r'L"otT, a hydrIJlogical. otand pt:>lont the levals of organic.:
contaminants may h&ve hedn redvceu OV6r the years d~e to the ~arge trans for of
groundwater through t.he s=~l, 1.n eesence, flu8hing the organics out of the area
and diluting the contaminaI',te uver time.
D.
REMAININq~9BcERN~
EPA is mainly concerned with ~he ~ontaminatton on site migrating into the
groundwater that may be used tor public water 8upply. FDER has raised concerns
w1.th the PRPs and EPA cuncer~i~g the Floridi~n Aquifer and its present
condition as ""811 as £trA8sing that they would not recommend further condujts
into the aquifer from t~e Zellwood site. Further studies may be needed to
conf irm the c;oncentr;oti0n of cor.ta..'T\lo:iants or lack of contalDinants from the site
l.nto the Florid1.an aqu~fer before the site can be deleted from the NPL. This
los.ue will be brought to th~ table i~ the future on~e Phase ~I of the remedial
investigat.i~n is completed by EPA. The citizens have not raised any cuncerns
since the October 5, 1989 puhlic notice. EPA plans to kdep the public and
local officiala informad of the actlvities EPA ia undertaking at the slte along
W1.th any new ~nformat1.on that may involve the site.
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