United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R04-88/031
December 1987
&EPA
Superfund
Record of Decision
Zellwood, FL
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50272-1 1
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R04-88/031
2.
3. Recipient's Accession No.
4. Title end Subtitle
SUPERFUND RECORD OF DECISION
Zellwood, FL
First Remedial Action - Final
S. Report Date
12/17/87
&.
. Author(s)
8. Performing Organization Rept. No.
9. Performln, O,.anlzatlon Name and Address
10. Project/Task/Work Unit No.
11. ContraetCC) or Grant(G) No.
(C)
(G)
.._._--
12. Sponsoring Organization Name and Address
U.S. Environmental Protection
401 M street, S.W.
Washington, D.C. 20460
13. Type 01 Report & Period Covered
Agency
800/000
14.
15. Supplementary Notes
I&. Abstract (Limit: 200 words)
The 57-acre Zellwood site is located in the northwestern corner of Orange County,
Florida, approximately one-half mile west of the unincorporated town of Zellwood.
Situated in a rural area, the site is occupied by four industries and an open field
containing a marshy wetland area. Approximately 300 'homes within a one-mile radius of
the site depend on private wells as their sole source of potable water. Between 1963
and 1971, Drum Service Company of Florida, a drum recycling facility, operat~d
wastewater disposal system without. a regulatory permit, treating and disposing of
generated wastewaters in two onsite evaporation/percolation ponds. In 1980, the company
eliminated the use of these ponds for waste disposal and in August 1981 initiated
drainage and removal of contaminated sediments from the ponds. Douglas Fertilizer and
Chemical Company and Southern Liquid Fertilizer discharge wastewater from their
production process into three unlined surface impoundments. Additionally from 1960 to
1983, the Zellwin Farms Company facility, a vegetable washing and packing plant,
discharged wastewaters from the vegetable washing process into a ditch. From 1971
through 1985, the Drum Service Company has had various types of waste treatment and
disposal permits issued by the Florida Department of 'Environmental Regulation (FDER).
To date, the Douglass Fertilizer and Chemical Company and the Zellwin Farm Company have
(See Attached Sheet)
17. Document Analysis a. Descriptors
I l.
Record of Decision
Zellwood, FL
First Remedial Action - Final
Contaminated Media: gw, sediments, sludge, soil
J<~nt~.Q~!hiIU\t4i.;ms chromium, inorganics, organics,
pesticides, toluene
c. COSATI Field/Group
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EPA/ROD/R04-88/031
zellwood, FL
First Remedial Action - Final
16.
ABSTRACT (continued)
not been permitted by FDER. In December 1982, EPA.representatives discovered an
abandoned drum storage area in the northern section of the Zellwood site. Based on
unsubstantiated reports from area residents, material in this drum storage area may have
been there for more than 20 years. In the fall of 1983, EPA oversaw a PRP removal
action of the abandoned drum area. The primary contaminants of concern affecting the
ground water, soil, sediments, and sludge include: organics, inorganics, metals, and
pesticides.
The selected remedial action for this site includes: excavation of soils and
sediments with onsite incineration and testing of residuals to determine appropriate
disposal; ground water pump and treatment with flushing of the treated ground water back
through the abandoned drum area to facilitate cleanup of residual contamination; and a
long term ground water monitoring program for private potable water wells. The estimated
present worth cost for this remedial action ranges from $41,264,244 to $61,908,244 with
estimated present worth O&M of $13,543,244 (excluding ground water treatment and
remediation). The present worth range incorporates variations in the soil and sediment
volume that will be incinerated. .
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DECLARATION FOR THE
RECORD OF DECISION
SITE NAME AND LOCATIOO
Zellwood Groundwater Contamination Site, Zellwood, Florida
STATEr1ENI' OF PURPOSE
This decision document represents the selected remedial actio~ for this
site, develoPed in accordance with CERCLA, as amended by SARA, and to the
extent practicable, the National Contingency Plan.
The State of Florida has ~ot concurred on the selected remedy.
STATEMENT OF BASIS
This decisio~ is based upon the ad~inistrative record. The attached
index for the administrative record upon which the selection of a remedial
actio~ is ~~sed identifies the ite~~ which comorise the administrative
record.
DESCRIPfICW OF THE SELECTED RE'1EI)'i
-Excavation of soils/sedime~ts i~ the three on-site ditches, the existing
abandonp.d dru~ area ponds, the temporary sludge storage area, the two
fo~r ?erculation ponds, and the waste piles:
-on-site thermal destruction of the excavated soil/sediment:
-Appro?riate leach testing and disposal of the incinerated soH:
-Groundwater removal and treatment for the ~hallow aquifers.
be used as clean-up a~d treatment criteria.
ARARs wi 11
-Flu~hing the treated groundwater back through the abandoned drum area,
to clean up the residual contamination;
-An attempt will be made to locate and plug up any abandoned wells or
boreholes in the area; .
-A long-term monitor program for the private potable water wells in the
area.
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DECLA.RATION
The selected remedy is protective of human health and the envir0nment,
attains Federal and State requirements that are applicable or relevant
and appropriate, (or that a waiver can be justified for whatever ARARs
which will not be met), and is cost-effective. This remedy satisfies
that preference for treatment that reduces toxicity, mobility, preference
for treatment that reduces toxicity, mobility, or volume as a principal
element. Pinally, it is determined that this remedy utilizes permanent
solutions and alternative treatment (or resource recovery) technologies to
the maximum extent practicable.
T1Fr 1 7 1Qq1
~? W-L: -L:J- -
Lee A. DeHihns, III
Actinq Reqional A~inistrator
Date
.
.
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SECfION I
SITE UOCATION AND DESCRIPTION
The Zellwood Groundwater Contamination Site is located in the northwestern
corner of Orange County, Florida; approximately one-half mile west of the
unincorporated town of Zellwood. The 57-acre site, as shown in Figure 1-2,
consists of an area occupied by four industries and an open field with a
marshy wetlands area.
The site is situated in a rural area. Small residential communities are
located to the north and to the east; agricultural lands to the south and
west. There are approximately 300 homes within a one-mile radius of the
site. These homes depend on private wells as their sole 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. Besides the industries and the residences; there are several
plant nurseries, vegetable growing operations, and citrus groves.
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 their on-site
operation. The business was operated until 1981 when the plant was
purchased and operations were assumed by the Douglass Fertilizer and
Chemical Company. Douglass Fertilizer sold the property and moved its
operation to a new off-site location in 1984. The former fertili~er
production area is now occupied by Coatings Application and waterproofipg
Company. Chemical Systems, Incorporated, located on the western part of
the site, commenced operations in 1982.
1
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SECrION I I
SITE AND REGULATJRY 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 majority
of residences north of the sit€ and the Willow Stre€t Community Center
have been established since 1965.
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 is occupied
by Coati~s Application and vlaterproofing Canpany. In addition, several
other businesses are located in the industrial area surrounding the site.
Adjacent to the Zellwin Farms facility is a migrant worker hotel.
Approximately one-half ~ile north of the site are several residential
develooments and the Willow Street Community Center. Adjacent to the
site on the south side are muck farms, and the remaininq areas surroundinq
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~ile radius of the site can be divided into f.ive major
categories. 'Agriculture, primarily muck farms and citrus groves accounts
for 74 percent of the area's land use. Residential uses total 10 percent,
followed by commercial industrial and transporation areas ocupying 9
percent. Seven percent of the land area is combined lake and wetland
areas.
PREVIOUS SITE ACTIVITIES
Drum Service Company of Florida, a drum recycli~ facility, began operations
in 1963. In th€ 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, eliminati~ the use of the ponds for waste disposal.
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
2
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county. To cernplete the clean-up of the two ponds, Drum Service Ccrnpany
of Florida constructed a temporary sludge storage area consisting of an
earthen berm at the western edge of the drum storage area. The sludge
was subsequently removed frern 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 and the area where the temporary sludge
storage area existed is now used for drum storage.
Douglass Fertilizer and Chemical Company and the previous business,
Southern Liquid Fertilizer, had three unlined surface impoundments which
received wastewater frern 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. Reportedly, this ccrnpany 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 paralleling Jones Avenue. In 1983,
water frern 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 their facility south of Jones Avenue.
The remainder of the water is still discharged to the southern ditch.
In December 1982, representatives of the EPA discovered the abandoned.
drum storage area located on an.approximately 6-acre field north of the
northern ditch and south of the Seaboard Coastline Railroad in the northern
section of the Ze11wood Groundwater Contamination Site. The abandoned
.drum area was apparently used for the disposal of drums and other wastes.
Based on the unsubstantiated reports frern residents in the area serne of.
the material may have been there from more than 20 years.
The Ze11wood site was listed on the first final National priorities List:
which was published in the Federal'Register in '1983. In the fall of
1983, EPA's Region IV Emerqency Response Control Section (ERCS) oversaw a
PRP removal action of the abandoned drum area of the site. In 1984, a
Remedial Action Master Plan was developed and a WOrk Plan for the RI/FS
was formulated. Negotiations with the PRPs were initiated, but it was
indicated by the PRPs that they did not wish to implement the EPA WOrk
Plan. EPA, via its contractor NUS-FIT, llnplemented the RI/FS in 1985.
3
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REGULATORY 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 usinq 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. FD~~ issued Operation Permit No. I048-2077 for
this system on July 31, 1975. In 1980, further design changes were made
eliminating use of the ponds for storage of wastewater. As of 1985, Drum
Service Company of Florida held FDER Permit No. A048-27470B 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 Cbuglass Fertilizer and Chemical Conpany and the Zellwin Fam C01lparr;
have not, in the past nor currently, held any industrial waste treatment
of disposal 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. As of the date of this ROD, the outcome of the suit is
unknown.
4
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SEcrION III
CURRENT SITE STATUS
SITE GEOUX;Y AND HYD~EOUX;Y
The Zellwood site is underlain by an unconfined surficial aquifer and the
artesian Floridan aquifer. Regionally, the water level ranges from
llnmediately below ground surface to greater than twenty feet below ground
surface. The shallow aquifer fluctuates in response to recharge and
discharge mechanisms and 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 may be due to continual 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.
Separating the 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 move-
ment 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.
Underlying the Hawthorne is the Floridan aquifer. This aquifer 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 measure-
ments taken in the Floridan aquifer wells at the site in May, June, and
September were plotted and contoured. Examination of this data confirms
a divergency from the normal northeasterly flow and suggests that water
levels at the site are not representative for the determination of a
regional flow direction in the Floridan aquifer. The anomalies of the
potentiametric.sur~ace of the Floridan aquifer could be an ef~ect of
numerous factors including a structural depression at the top of the
Ceala Formation, local pumpage of rm.micipal 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. Conservatively, it
may be assumed that in the site vicinity, flow in the Floridan aquifer is
radially away from the site for a lUnited distance before the regional
northeastern flow direction becomes dominant.
PREVIOUS SITE INVESTIGATlOOS
Numerous investigative activities have taken place at the Zellwood
Groundwater Contamination Site since 1980. Following are a few of these
activities:
5
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I,
o
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.
o
In April 1981, the FDER analyses of groundwater samples taken 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. A surface water sa~le was also collected from the large pond
on Southern Liquid Fertilizer.
o
In November 1981, Drum Service Company of Florida contracted Seabury
and Bottorf Associates, Inc. to conduct a soil and water sampling
investigation along the right-of~ay 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 ~/kg were found in the soil at each of the'
three locations.
o
Geophysical studies conducted by the FDER in 1981 and the Ecology &
Environment Inc., (E & E) Field Investigation Team (FIT) in April and
July 1982, indicated the presence of possible groundwater contamination
plumes on the south side of both Drum Service Company and Douglass
Fertilizer Company. .
~
During July and August 1982, FIT (E & 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
analyses. Much of the data was unusable because of QA reasons.
j
The EPA Environmental Services Division (ESD) conducted a hazardous
waste site field investigation during December 1982. Several metals
and orqanic compounds were detected in the soil/sediment and water
samples. Of particular interest, were the cadmium and lead that were
found in two potable water wells.
o
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 Remedial Investigation and Feasibility Study.
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SEC!ION IV
REMEDIAL INVESTlGATIOO RESULTS
DESIGN OF THE REMEDIAL INVESTIGATIOO
Previous studies at the Zellwood Groundwater Contamination Site indicated
several major co~cerns. The combined factors of the shallow water table
and the known waste disposal/treatment practices led to the public health
concern of possible groundwater contamination. Another concern is the
transport of contaminants via the drainaqe ditches since these ditches
have historically been collp.ction points for run-off of potentially
contaminated surface water and soil. A third concern is the potential
public health threat that may have existed from contaminant migration
and/or direct contact with on-site contaminants or waste.
Groundwater qual i ty in both the surficial and Floridan aquifers and the
other potential contamination migration routes were investigated during
the RI. The investigation included a subsurface boring program, installation
of 17 monitor wells, grounqwater sampling and analysis, and data evaluation.
Surface water and sediment samples were also collected from ditches within
the study area. Th~ results were compared with previous study results to
assess changes in water quality. and sediment contaminant levels. The
contaminants found in the surface water and sediment samples were evaluated
to identify sour~e areas. .
The waste area at the site were identified using historic aerial photographs
and geophysical techniqu~s. Surface and subsurface soil samples were
collected from these area 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.
CONTAMINANTS OF CONCERN
All of the samQles taken for the RI were analyzed for the chemicals on
the CLP-Hazardous Substance List. In addition, the water samples were
analyzed for the standard parameters and for sulfates.
The results of the investigation indicated that a varied assortment of .
chemical contaminants were found at the site. In an attempt to focus the
interpretation of the results, a screening process was .initiated as part
of the RI. The screening process was a qualitative "best engineering
judgement" process that took into account present site conditions;
physical, chemical and environmental rate and mobility of the contaminants;
number of different mediums that were found to contain the individual
contaminants; and qualitative health effects and the environmental impacts
associated with exposure to the contaminants. The resulting list of
contaminants can be found in Table 1. The list in Table 1 is used for
7
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TABLE ONE
Chranium
Lead
Mercury
Cyanide
Nitrite
Toluene
Phenol
OOT/DDE/DDD
Arsenic
Cadmium
Chlordane
Potassium
Total Phosphorus
Arrmonia
Zinc
Aluminum
Iron
Silver
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TABLE 1m
Arsenic
Benzo (a) pyrene
Chlordane
Chronium
Nitrate-Nitrite nitrogen
Cyanide
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purposes of clarity throughout most of this ROD. It should be made clear
at this juncture that this list in no way represent the sum total of
chemicals found in each sample.
There is only one area that a different subset of chemicals was selected
for evaluation. This different subset can be found in Table 2. This
subset was developed usi~ the "indicator chemical" process found in the
Superfund Public Health Evaluation Manual (draft December 17, 1985, 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 Sectio~ V of this ROD.
SOILS INVESTIGATICN
Soil samples were taken in several designated areas of the site. The
designated areas were: 1) Abandoned drum area; 2) former Drum Service
pe~culation ponds: 3) temporary sludge storage area; 4) railroad right-of-
way; and 5) current Drum Service area. The soil sampling locations can
~ seen on Figures 3-10 and 3-14.
Subsurface Soil
Twelve subsurface soil samples were collected from the historic waste
areas throughout the site. The samples were collected by augering from 6
to 18 inches and from 2 to 3 feet. For presentation of the data, the
subsurface soil samples have been grouped into two categories; abandoned
d~lm area and other areas.
The selected contaminant results of the subsurface soil samples
from the abandoned drum area are presented in Tables 3-15 and 3-28,
respectively. The analytical results of subsurface soil samples from the
other areas are presented in Tables 3-19 and 3-28.
SURFACE \-JATER AND SEDH1ENT INVESTIGATION
Several areas were sampled as part of the surface water/sediment portion
of the investigation. These areas are 1) the northern, middle and southern
ditches; 2) the four ponds in the abandoned drum area; and 3) the three
ponds on the former Douglass Fertilizer Company property. The sampling
locations can be seen on Figure 5-5.
NORTHERN DITCH
rh~ northern ditch begins at the northeast boundary of the site and
travels westerly along the northern site border then south of the
abapdoned drum area. At the eastern boundary, the northern ditch flows
under the railroad tracks and south toward the southern ditch.
8
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TARLe s..JJ .
COMPARISON OF SELeCTED CON1 AMiNANTS IN SURFACE .A TER
MIDOLE DITCH
ZELL.OOO GROUNO-A TER COOT AMlNAT10N SITE
oRANGE COUNTY, FLORIDA
5.-." 5W-11/0-7 SW-I~' SW~20
(Canlrol)
Parimelft ~ ---lill.- ' 2/1' 12/12 -lID- U/12 ~
CtrotniUln II 9~0 "0 120 12
Lead 100J ~,700 ',OOOJ ),600 ~OJ
Mert:wr . - NAI NAI
Cyahide .,0 R 110 R
Nitr.te-Nitrite N R NA R NA R
T ohaene 29
Phenols 'J 10J U
',"'..001 NA NA
',"'''00£ O.06J NA NA
',"-OOD NA NA
Chldrdane NI\ NI\
Alpha-chlordane NI\ NI\ '.J NI\ .011 NI\
Gamma-Chlordane NI\ NI\ . NI\ .on NI\
Material was .al,zed lor but not detected.
J Estimated value.
R Qualit, control Indicates .ta not useable.
NA Not ...al,Rd.
NAI Analyses not perlormed due to Interlerences in sample.
,
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The northern ditch flows under the railroad tracks at the western end and
then southward toward the southern ditch. As can be seen from Table 5-31
the concentrations of mercury and chlordane in the sediment sample indicate
that contaminants have migrated to at least the sample location in the
connecting ditch (55-31).
MIDDLE DITCHES
The middle ditches consist of two parallel pathways north and south of
the railroad tracks. Just north of the Douglass Fertilizer building the
middle ditch flows northerly under the tracks and proceeds northwesterly
toward the northern ditch.
5urface Water
The natur~ of the surface water contaminants found in the middle ditches
are presented in Table 5-33. The table also includes the results of the
analyses of samples c011ected at the same locations as 5\~18 (designated
0-7) ,and 5~19 (designated 0-6) during the EPA Deoember.1982 investigation.
All three samples collected during the RI indicate the presence of lead
and chromium. The results from the 1982 investigation also indicated
above background levels of lead and chromium in the water samples.
5ediment
Table 5-34 presents the concentrations of contaminants in sediment samples
collected from the middle ditches. The results from the EPA December
1982 investilation are also included. The 1982 samples were collected
from locations similar to 55-19 and 55-18 and are designated as 0-65 and
0-75, respectively. During 1982 EPA investi']ation, the highest sediment
concentrations of all contaminants except cyanide found in the sediment
sample collected north of the Douglass Fertilizer buildinq (55-21) appear
similar to those found in the Douglass Fertilizer west pond sediments and
therefore may be the result of run-off from the Douglass Fertilizer
property. The concentration of contaminants found in the Douglass
fertilizer Company west pond are presented in Table 5-35.
The concentrations of iron, aluminum and zinc are highest in the sediment
sample collected from the middle ditch north of the rairoad tracks (55-18).
The higher concentration of these contaminants in this sample suggests that
this area currently or in the past has received run-off or groundwater
seepage from a different source. The temporary sludge storage area
is the most likely source for the contaminants. This is substantiated by
the comparison of the concentrations of chromium and lead in sample 55-18
to those in the samples from the eastern end of the northern ditch (55-3,
55-4, and 55-6). 5ince 55-18 had higher concentrations of chromium and
lead t~an the eastern end of the northern ditch, it has or is being
9ffected by another source. Table'S-35 contains concentrations of
contaminants from the subsurface soil samples collected in the temporary
sludge storage area that could have effected the middle ditch.
10
-------
'~ftLe ~"
COIIP~.I~ OF 5I!UCfEn CONr~I8N~HYS" 5DII_"'
""HERN ..rot - SOUtH ~NI) WUf OF A"ANIJONEn DRUM ~.!~
lULtroOO (;,AO'..nWAIER CONrA"N~'1UH seff.
ORAH(;,E COUNr y. fl.ORIDA
... »-, ..., »-"~IS B-II B-)8
tc-enI8
..........,... III' 1/8' "" "" n/ll 1/1' II"
Arwnic: 10,000' 10,000' 10,000' .,100
C...."ium 100,000 "0,000 90,000 110,000 1.- t,"
h... -.IOOJ 100,000) '.000.000' 100,000) . 110.000 1,000'
Mftcur, J.lOO '.100 1,100 19.000 .,0
l. ,Mi. R If If '.000
N"r.'~-N'IrUe N R It It N~ . R
'..IUIPM IU t.IOO' JJ IU
1'hPflo1,
'.".nnr 10 "A
'."-OnE "0 '. 700C "..000 ',100 "A II ItO
'....oon ,'oc tlON "A 21" II
t:....... II. GOON H. OOON ",OOON NA "ON . . tOON
G_"'..dtIar.... - NA "A NA "A N~
J
R
"A
"
C
....«1" .. ....,~ I. ... ... *18d'"
t'li"'.'H ."ue.
Qua"" C_.,aI ""a... .... .. .......
Ita. ....,...
",ft"""'" .wI*"m .. ....... .. ...«1".
C_'Ar"'" .. GC/MSo
-------
TARLE S-)O
COMPARISON OF SELECTEn CONT AMINANTS IN SEOIMI!NT
NORTUERN DlTC.. EAST 01: TUE ARANOONEO ORtJM AREA
ZELL -000 GROUNO. A TEA CONT AUINA TION sITe
ORANGE COUNTY, FLORIDA
5.\-1 SS-, 5S-) SS-t 55-6 5S-7
(Cantrol)
P..-ameter ~ 2/" 2/" 2/'" --.l!" 2/t'S 2/"
Ctw'omium 20,000 10,000 ",000 69,000
L~ad t,OOOJ 20,OOOJ ~O,OOOJ 70,000) 200,OOOJ 200 , 000 )
Mercury 9) "0 )00 I , 900
Cyanide R
Nitrate-Nitrite N 1),000 7,000 8,200 R
T ol~ne r,])
Phe.tols
',"'.bnT 20 }. ) '0 160 )ION
',"'.hOE 2"0 21 "ON 720N I , 200 " , 'JOO
","'.bno 7"OC J.9 17 I' ISON
Chlordane 1)0 7'ON 2, ~ON ",OOON
Gamma-chlordane 100 NA NA NA NA Nt\
Arsehic - 11,000 R
Iron .220,000 "0,000 '. ~O,OOO , . 800,000 11,000,000 ',100,000
R
1
N
C
NA
Materi.1 was analyzed lor but not *tected.
Quality control indiates data not useable.
Estim~ted v~lue.
Presumptive evidence 01 presence 01 material.
Conlirmed by GC/MS.
Not iIf\~lyzed.
-------
T AALE J-2'
COMPARISON OF SELECTED CONTAMINANTS IN SURFAce WATER
NORTHERN DlTm
ZELLWOOO GROUNDWATER CONT AWNA 110N SITE
okANGE COUNTY. FLORIDA
5W-IJ SW-I' S.-17/1)..1 5W-)1
(Cancro"
Patameter ~ --1ill- 2/. 'J ". 2/.' IZ/12 Z/.,
Chromium 20 11 ., 190
L~8d 10J ,00J
Mercw, }.o
Cyanide R R II
Nitr ate-Nitrl te R R NA
Toluene U
~nuls
",It'-OOT NA
","'-OOE NA
Chlordane NA
Gamma-chlordane NA NA NA 0.067 NA
Alpha-chlordane NA NA NA 0."2 NA
r
Material was enal,zed lor but not delecl~d.
) Estimated value.
R Qualit, Control indic.les dala 001 useabl~.
NA NOl ...al,zed.
-------
5urface Water
The nature of the surface water contaminants found in the northern ditch
is presented in Table 5-29. This table also incudes the results of the
analyses of a sample collected at a sample location similar to 5W-17
(designated as D-8) during the EPA December 1982 investigation. This
table indicates that a variety of contaminants, not present in the control
sample, were found in the surface water samples collected at all three
locations.
Sediment
Table 5-30 and 5-31 present the concentrations of contaminant in sediment
samples collected in the northern ditch east as well as south and west of
the abandoned drum area, respectively. Chromium, mercury, and chlordane
were found in the sediment of the northern ditch east of the abandoned
drum area (55-3, 55-45, 55-6, and 55-7) although the contaminants were
not found in the sediment of the northern fork of the northern ditch (55-1,
55-5). These three contaminants were also present in the composite
surface soil samples collected from the drum storage area. The presence
of these contaminants appears to be related to run-off in surface soils
in the drum storage area and possibly from active operations of drum
storage. A comparison of the concentrations of iron and lead in samples
collected east of the abandoned drum are (55-3, 55-4, 55-6 and 55-7) with
the surface soils of the abandoned drum area and drum storage area
substantiates the run-off asumption. Table 5-32 presents the concentrations
of contaminants in areas that could be providing a source of contamination
to the northern ditch. 5ix extractable organics were' also detected in
the southern fork of the northern ditch.
The concentrations of chromium, mercury, lead, and chlordane are one to
two orders of ma~nitude higher in sediment samples south and west of the
abandoned drum area (55-9, 55-14 and 55-17) than in other areas of the
northern ditch. The hi~h concentrations of these contaminants suggest
that this area is receiving run-off from the abandoned drum area and
overflow from the larqe pond located on the southwest part of the abandoned
drum area. The samples from the area south of the abandoned drum area
(55-9 and 55-14) also contained toluene, ethylbenzene, xylenes, acetone,
bis(2-ethylhexhl)phthalate and DOT and its derivatives. The operations
in the drum storage area may also be effecting the nature and concentration
of contaminants in samples collected from these two locations (55-9 and
55-14) .
5amples were also collected west of the abandoned drum area at locations
55-17,55-16 and 55-31. The nature and concentration of contaminants in
the sediment sample at tl1e west end of the northern di tch (55-17) are
similar to those in the sediment samples collected east of the abandoned
drum area (55-3, 55-4, 55-6 and 55-7). This suggests that a source of.
contamination may be run-off from operations conducted in the active drum
storage area.
9
-------
TABLE 3-U
MAXIMUM CONCENTRATJONS OF SELECTED CONTAMINANTS IN SlmSURFACE SOIL
ABANDONED DR UM ARf.A
ZELL 900D GROUND" A TER CONT AMJNA TION SITE.
ORANCE COUNTY, F1.0RIDA
AC-I. AC-2. AC-' NA-I
Sh&llow Deep Waste Piles
C'. - 11") (2' - 3') And Drums
'aram~ter ~u~/kd 211' 2/1' 12/12
Chromium 200,000 ',100 1,200,000
Lead 100,000J. 1,000J ',600,000
Mercury 2,000 110 13 ,.000
Cyanide 2,100 10,000
Njtrat~-Nitr ite..N NA NA NA
T oj uene 110 240 10,000
PJ,enols - .
II ,lI'.DDT 33~ NA
4,4'.00E 1,300 NA
II,II'.DDO NA
Chlordan~ "",000 70J NA -
Gamma Chlordane SA NA 11 ,000
Alpha Chlordane .' NA NA 7,300
Cadmium 3,'00 28,000
J
NA
Estimated value.
Material was analyzed for but not detected.
Not analyzed.
-------
TABLE 3-22
MAXIMUM CONCENTRATIONS OF SELECTED CONTAMINANTS.lN SUBSURFACE SOIL
DRUM SERVICE COVERED PONDS
ZELL "000 GROUND" A TER CONT AMINA TlON SITE
ORANGE COUNTY, FLORIDA
Northern Pon~ Southern Pond (AG-6/A)
Paramatef' (U2!k() -12/&2 2/&5
12/12 2 &5
Chromium 3,300 13,000 U , 000 3,000
Lead 7,000 30,000J 35,000
Mercury 190 760 .500
Cyanide 190 1,000
Nitrate-Nitrite N NA NA NA NA
Toluene 22 IJ
Phenols
1f,4'-OOT NA 120 NA
4,4'-ODE NA 68 N:\ 5~~
1f,4'-00D NA NA
Chlordane NA 3,200 NA
Gamma-Chlordane NA .5.9 - NA
Alpha-Chlordane NA '.6 NA
J
NA
Material was analyzed for but not dete<:ted.
Estimated value.
Not analyzed.
-------
TABLE )-21
COMPARISON OF SELECTED CONTAMINANTS IN "ASTE PllES
NOR TH OF ABANDONED DRUM AREA
ZELL WOOD GROUNDW A TER CONT AMINA TlON SITE
ORANGE COUNTY, FLORIDA
CS-, 55 "'" °
Waste Pile Waste Pile
parameter (usUkV 2/1' 211'
Chromium '20,000 14,000
Lead 3.000.000] 100.000]
Mercury 41.000 300
Cyanide
Nitrate-Nitrite N R '.400
Toluene '90,000]
Total Xylenes 1,200,000
Phenols
4,4'-DOT '2
4,4'-ODE 40,000 "0
4.C,'-DDD lOON
Chlordane 470N
.
J
R
N
Estimated value.
Material was analyzed for but not de1ected.
Quality Control indkates data not useable.
Presumpti'/e evidence of presence of material.
. .
-------
TABLE 3-19
MAXIMUM CONCENTRATIONS OF SELECTED CONTAMINANTS IN SUBSURFACE SOIL
TEMPORAR Y SLUDGE STORACE AREA
ZELLWOOD CROUNDfr'ATER CONTAMINATION SITE
ORANGE COUNTY. FLORIDA
Ae-..A PT-l
2-3 ft Com~site
Parameter (uVkv 2/" 12/12
Chromium '1
Lead 320
Mercury 76 220
Cyanide 1,'00
Nitr ate-Nitrite-N NA NA
Toluene '3
Phenols 60J
.,4'-00T NA
4,4'-ODE NA
4,4'-000 NA
Zinc 200,000
Aluminum 1,6QO,OOO 3,700,000
Iron 22,OQO,000
J
NA
Mate:-iaj w~ analyzed for but not detected.
Estimated value.
Not analyzed.
-------
Pw.... I~
B-1
ec--o
II"
,,,ftt.~ to.,.
COIIPARfSO't g: seucun O1N'"I8HAHr''' .......,
...nnt.~ ",Ot
Z~llWOOO .-..01..0.1' ,f.. CON'''I8HA1IOH SI'I!
mANtZ COUtTY. FLOIIIM
B-1 I" B-1tfD." B-JO B-IIID-IS
II" J/" U/" 1/1' 1/81 U/"
'.900 I,too I." '.900 .., OlIO ",000
10.0001 10,0001 ".000 10,0001 --.0lIO) 110,000
IJO 110 ',000 '60
. "OK '00
. M HA A . HI'
HAl IlJ It) II
~ H
HI' HI' .
.. HI' 1,100 HI'
HI' HI'
IIN . HI' HI'
"'1' ''''1' HI' HA ,",0
HI' . HI' HI' HI' 710
'10.000 JO.OOO 11.000 11,000 1.-,000 IDO, 000
"0.000 no, OUO "0,000 "0,000 10,100.000 '.000,000
110.000 tOO. 000 . .610,000 no, 000 ',MIO.OIIO I.MIO,OOO
Clwalnl-
hed
Mrrdlr,
C r-Ictr
HI".'~-H""'e H
T 01....
""'IOI)ls
t,,'.do,
',"-OOE
t,,'-oon
C".'"
AI~ ctt"'''.
G-iM dIIar...
lenc
Alt.""""
It""
'.0lIO)
10
,to
'toe
IDO
''',100
110,100
M.'~I" ... "","1. .... ... .'ecte.l.
J E IIj",.tecl ..Iue.
KArt.... ..Iue I, ....... .. .. In' .... alue IPftft.
R Quahl, Contfol 6n11iC.I" cia'..., ,,""e.
HA Hot ..aI,_d.
H P'ftdftpllft e"*nce.. "esence D' "'er'~.
HA' Inter lerer,",s.
C Con"""" " GClIn.
-------
TABLE '-3'
COMPARISON OF SELECTED CONTAMINANTS IN sorL/SEDIMENT
POSSELE SOURCES OF CONTAMINATION OF MIDDl.E DITCHES
ZELLWooD GROUND. AT"fR CONTAMINATION SITE
ORANGE COUNTY, FlORIDA
Ac:r'/A./PT-I 5.> 22
Subs\lface Soil Pond Sedi men t
Parameter (UlIkI) Temp. S1udae Area Dou&Jass Fertilizer
211' 12/12 2/1'
Ctromium '1,000 200,000
Lead 320,000 100,OOOJ
Mercury 76 220
Cyanide 1 , '00 R
Nitrate-~itrite ~ NA NA R
Toluene '3 4QJ
Phenol 60J
4,4'-00 T ~.4.
4,II'-00E NA 37
4,.'-000 NA 6JN
Chlordane NA ClOON
Alpha Chlordane NA NA
Camma Chlordane SA NA
Zinc 200,000 11 ,000,000
Aluminum 1,600,000 3,700,000 18,000,000
rron 22,000,000 42,000,000
.
Maximum concentration from two depths.
"Estimated value. .
Quality control indicates data not useable.
Material was analyzed for but not deteCted.
Not analyzed.
:7
R
NA
-------
SOUl'HERN DITCH
Surface Water
The nature of the surface water contaminants found in the southern ditch
is presented in Tables 5-'36 and 5-37. These tables also include the
results from the EPA December 1982 investigation when samples were
collected at locations similar to SW-25, SW-28, S~29, and S~~33, and
designated as D-2, D-3, D-4, and D-5, respectively. For the purposes of
this discussion, the surface water in sample S~25 is considered the
upstream control sample, since this sample includes the discharge from
Zellwin Farms after it enters the ditch. The discharge from Zellwin Farms
is a major source of water in the southern ditch. Other surface water
collected at the boundary between Douglass Fertilizer and W. R. Grace
(~43) is considered to represent the surface water quality leaving the
Ze llwood Groundwater Contamination Si te.
As shown on Tables 5-36 and 5-37, the highest concentration of contaminants
was found in s~mples collected downstream of the site boundary and behind
an abandoned paint shop (~33). The furthest downstream sample (~36),
approximately 1,400 feet fram the site boundary, contained no contaminants
of interest at significant concentrations. Therefore, it does not appear
that even the contaminants contributed by off-site sources are migrating
in the surface water of the southern ditch more than a few feet.
Sediment
Tables 5-38 and 5-39 present the concentrations of contaminants in sediment
samples collected in the sourthern ditch. The results from the EPA
December 1982 investigation are also included. These samples are designated
as D-2S, D-3S, D-4S; and D-5S and were collected from locations similar
to SS-25, SS-28, SS-29, and SS-33, respectively.
The southern ditch runs along the northern side of Jones Avenue at the
. site. Because of the proximity of the ditch to the road and the heavy
traffic of cars and truck, the ditch sediment contained a wide variety of
polynuclear aromatic hydrocarbons (PAHs). These compounds in the sediment
samples may be related to the asphalt paved surfaces since the asphalt is
composed of coal tar derivatives which contain numerous aromatic hydrocarbons.
The concentrations of chromium, lead, and mercury in the sediments samples
during the EPA December 1982 investigation are generally higher than the
concentrations found during the RI. The exception is the sediment sample
collected behind the abandoned paint shop (SS-33). An examination of the
concentrations of both the inorganic and organic contaminants in the
sediment samples collected during the RI indicates a significant increase
in the concentrations of the contaminants of interest in the samples
collected at and just dOWT'lstream of the site boundary (SS-43 and SS-33).
.
11
-------
JAN.I! J... K
COMPAIIISQf OF 5ell!CTfO CON' A"NANTS .. SU.fACE WA nil
~ITIIENN OI'Ot EA\T OF nOUQ.An fflUllllfR
If-1.lWOOO (;,ROUNOWAUM CON'A"NA 'k" ~fE
. ORANtI COt..ry. H.ORIf)A
~Wf).1 Sw-u SW-l~O- 1 SW-l!IO-'
P.~~L m I Jl~L --.1!~~- .' '!~~ .--Hl.~-- ~, -~ll~
CtwOln".n 1.6 II
l...d "
M.HUf'
l:,.,,* II , A A - II 1.1
Hi".'.-NIU'le N . NA R Ie NA A NA
'ut'R- JJ
Ptwnoh
',".I)[n NA NA NA
',"-OnE NA NA HA
-,".000 NA NI\ HI\
Chi.. cI.ane NA HI\ NA
~8m1n..Chlar'" NA .NA HA NA ....
Alptw. Chi.. d8ne NA HI\ HA NA O.lt
J
NA
Ma'"'" .. MAl,.. f. .... ... *I.e'ed.
E".."aled "alur.
HOI .anal,led.
-------
TARLE S-J7
COMPARISON OF SELECTED CONTAMINANTS IN SURFACE WATER
SOUTHERN DITCH WEST OF DOUGLASS FERTILIZER
lELL WOOO GROUNOW A TER CONT AMINA TlON SITE
ORANGE COUNTY. FLORIDA
SW-)O SW-'} SW-}}ID-'
Paratneter 4m&/lca~ -1ill- 2/.~ 2/.' 12/12
Clw'otnium " )1 )80 10
Lead 200J IOOJ 2,ooOJ
Mere", 1.6
Cyanide R 9.6
Nitr..e-Nitrile N R It R NA
T oltltne
Phenols
',"'-DOT NA
',"-DOE 0.07J 0." 2.9 NA
',"'-000 NA
Chlotdane 0.') 7.2 26 NA
Gamtna-Chlordane NA NA NA 0.'.
Alpha-Chlordane NA NA NA 0.016
.
Material was anal, zed lor bul nol detected.
J r:.,'hna.ed value.
NA Not analyzed.
SW-K
2/1'
).1
-"
R
NA
NA
-------
TABU ~ JI
COI8"AR'SON (W SflfCIEn CON'A18NANTS... SE"IIENT
~".tf..N "'m fAH OF nOUG.AU nR'lllll!.lt
ZEUwoon (;'.UM..nWAffR OJNJAI8NAflON sail!
ORANY! c.ou.JY, FlOltIM
... ... CUiII'.)
B-1
ec...r.u
l/IJ
~1)/D-n ~16 ~IIlD-JS B-ltJD...s
1/" ---!ll~ 1/" 1/" U/U 1/" lUll
t,.oo 11,000 ",000 )0,000 ",001 ",000 ",000
IO,OOOJ 10,000 60,0001 60,0001 10,000 to,OOOJ '90,000
IlJO "0 ..0 100 100
IlOK A I," M 6,000
R NA M A NA R NA
R NA NA NA
110 NA 1,100 lOG 1 NA I. NA
11 NA 6001 1001 NA 601 NA
R . NA " 900N NA 1 , 700N NA
NA NA NA NA 1,700
NA NA NA NA 1,100
CtwO"Ml8n
LeN
Mt'f CII, ,
(: '8f1ldp
NII''',r-NII,ile N
J 0""-
I't1rnbh
',".00'
',".00£
t,"-OOO
ChIor~
G8m"'.-~-""
A IpN-chiur ct.ne
-,001)
10
'to
,.OC
100
NA
M.'er.aI was ..aI,... 1- .... ... .'ec'M.
J Elli.n.'~ ".Iur.
K Antllli ...Iur " ...... .. - Ins ,.... ..AI. Ihen.
R ~hl, conlfol indICAln .,. -. UIe~.
NA Not ...I,_d.
N "'n18npllft nltlrnce 01 pr~ .. ....'ert".
-------
........ t..II8)
-..
ec.......o
JIIJ
Cllromlum
l..ct
Metc~,
CJ8I\"~
Ni".,~-NUrile N
, oIurne
Ptwnol.
-,_'-oh'
-,"-DOE
-,,,-nho
C"ar".
(;8ftm.C"'--
"...... CNardine
',OOOJ
10
'"
,-OC
100
NA
M.I.iAl .., an",,, I. .... ... .'ecl~.
J £ ,..,,,..~ ..Iur.
.. Qu8UI, control lnclca." ...... .......
NA Not ....,.ct.
N Prnumptiw ewt*"ce 01 presence of ....1.1".
,,,en ~"
COIIPA"'~ OF seU!CYfO c.."ON'A"N"HTS.. SI!f1I_Nt
5OUf'~"N ..'a. .ur (1F ooua.An FEMfllIZI!R
ZUl.OOO (;,AOUNn."nR C~T""N"'ION SITE
OR"NGe c.."'OU\I'Y, FLORIDA
~JO »-U »- )J/~" B-M u-n -.16
I/It I/It . 1/1' 11/11 I/It 1/., III'
10,000 ",000 ",000 _,000 1,700 ",000 t, tOO
-,oooJ 100,000) _oo,oooJ 11,000 ',oooJ -0,0001 20,0001
" . ,100 1,-00 "0 110
M .. _,100 ..
11,000 M R N" .. .. R
601
.. HI' 1J8N
"ON ,.0 . J, JOO H" . II I,.uo '70
.17 -600) " HA 1O .00) ,to
no lI,oooN ",GOON H" 'tON U,GOON " toON
H" H" H" 1,600 HA N" HA
NA NA NA 1,100 NA HA HA
-------
MISCELLANEOUS DITCHES
Surface Water
The nature of the surface water contaminants found in the ditches south
of Jones Avenue is presented in Table 5-40. The water from the Zellwin
Farms facility south of Jones Avenue enters a ditch and flows west. This
ditch flows a short distance before merging with a southerly flowing ditch.
The surface water in the Zellwin Farms drainage ditch (SW-27) contained
low concentrations of lead, and toluene. The surface water sample
(SW-39) collected upstream from S~27 also contained acetone and trans-
1,2-dichloroethene. The presence of these two organic contaminants in
surface water at sample location S\~-39, although not at S~27, indicates
that these organic contaminants are apparently the result of upstream
contaminants in the ditch. It is possible that it is the result of run-
off from the asphalt road.
Sediment
The nature of the sediment contaminants found in the ditches south of
Jone Avenue is presented in Table 5-41. The sample (SS-39) containinq
the highest levels of most contaminants was collected upstream of the
area where the Ze11win Farms drainage ditch joins the southerly flowing
ditch. This sample contained concentrations of toluene and DOT and its
derivatives higher than those in other samples collected both upstream at
SS-38 and to the east at SS-27. The sediment sample collected at SS-39
also contained Trans-1,2-dichloroethene, methyl ethyl ketone, and 4-methyl
~henol. Since the upstream samples does not show any of the contaminants,
t~e little spur drainage ditch which runs north of the sampling location
may be the source of the contaminants. A sand parking lot exists directly
north of the short spur drainage dirch. Run-otf from the parking area
may be entering the ditch.
Since the contaminants in the miscellaneous ditches were not related to on-
site activities, the extent of any contamination in them was not addressed
in the RI.
PONffi
Most of the on-site ponds are related to the historic waste areas. The
remaining ponds, the northwest pond, the nursery pond and the W.R. Grace
fire pond, are discussed here.
12
-------
TABLE MO
COMPARISON OF SELECTED CONTAMINANTS IN SURFACE WATER
DITCHES SOUTH OF JONES A. VENUE
%ELLWOOD GROUNDWATER CONTAMINATION SITE
ORANCE COUNTY t FLORIDA
SW-l'
(Control)
2/8'
Parameter (uK/O
Ctv'omium
Lead
Merc:ur y
Cyani de
Niuate-'Htrite'l
ToJuene
Phenol
4,II'-00T
4,4'-ODD
If,II'-ODE
ChJordane
. .
J
R
Material analyzed for but not detected.
Estimated value.
Data invalid.
SW-27
.2/1'
59-39
2/"
20J
2'
30j
R
4J
4j
-------
TABLE '-'I
COMPARISON OF SELECTED CONTAMINANTS IN SEDIMENT
MISCELLANEOUS DITCHES
%ELLWOOD GROUNDWAnR CONTAMlNAnON SITE
ORANGE COUNTY, FLORIDA
SS-l SS-31 SS-3' 55-21
(Control)
Parameter (uK!1cK) 2/1' 2/1' 2/1' 2/35
Crv-omium 29,000 ',200
Lead 4,OOOJ
Mercury
Cyanide
Nitrate-Nitrite N R R R
ToJuene 600)
Phenols
4,4'-00E 240 ' 1 , 100 32
4,4'-00T 20 R 1,300 6
4,4'-00D 740C 3J 930 13
Chlordane R R
Camma chJordane SOD NA NA NA
J
R
N
C
NA
Material analyzed for but not detected.
Es~mated value.
Data invalid.
Presumpti ve evidence of presence of material.
Confirmed by GCI MS.
Not analyzed.
-------
Surface Water
The nature of the surface water contaminants found in the off-site ponds
and W.R. Grace fire pond is presented in Table 5-42. As shown, the off-
sita ponds located northwest and northeast of the site and at the W.R.
Grace facility contain no concentrations of the contaminants of interest
above the laboratory detection limits.
Sediment
The nature, of the sediment found in the off-site ponds is presented in
Table 5-43. No sediment samples were collected fram the W.R. Grace fire
pond because it was lined with concrete. Both off-site ponds contain
contaminants of interest at very low concentrations unrelated to site
activities.
SURFACE WATER AND SEDIMENT SUMMARY
The surface water and sediment investigation included the collection and
analysis of water and sediment samples from several drainage ditches and
ponds. There were three main ditches; northern, middle and southern, as
wall as four on-site ponds. The major source of the water in the ditches
is derived from run-off of rainfall; however, the southern ditch does
receive a direct discharge from the Zellwin Farms Company. There were
several potential sources of contamination identified as a result of the
sample analysis. The large pond in the southwest corner of'the abandon~
drum storage area appears to have contributed contaminants to the northern
ditch.
The water and sediment samples collected on the western end of the middle
ditch exhibit elevated concentrations of lead and and chromium, as well as
above background levels of iron, aluminum and zinc. These samples were
collected very near the location of the temporary sludge storage area.
The ditch is at a lower elevation ~han the sludge storage area. The
ditch is at a lower elevation than the sludge storage area and runoff
or groundwater seepage into the ditch is plausible.
Finally the southern ditch samples contained may polynuclear aromatic
hydrocarbons, apparently associated with run-off from the paved'asphalt
surfaces at the Zellwin Farms Company as well as from Jones Avenue.
GROUNI:WATER INVESTIGATION
The groundwater investigation portion of the project can be subdivided
into several portions. EPA installed seventeen new monitor wells: seven
in the upper part of the shallow aquifer; seven in the lower part DC the
13
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TABLE ~2
COMPARISON OF SELECTED CONTAMINANTS IN SURFACE WATER
MISCELLANEOUS PONDS
ZEl..lWOOD CROUNDW ATER CONTAMINATION SITE
ORANCE COUNTY. FLORIDA
Paramett!!' Cuxft>
CtYomium
Lead
Mercur y
Cyanide
Nitrate-Nitrite ~
Toluene
Phenols
~,c.'-DDT
4,4'-DDE
4,~'-DDD
Chlordane
SW-l'
NY Pond
2/.'
$1r-1
Nw-ser'Y Pand
2/.'
R
Material analyzed for but not detected.
Data invalid.
SW-32
".R. Grace
Fire Pond
2/.'
R
R
-------
TABLE '-43 .
COMP ARlSON OF SELECTED CONTAMINANTS IN SEDIMENT
MISCELLANEOUS PONDS
ZELL WOOD GROUNDWATER CONT AMINA TlON SITE
ORANGE COUNTY, FLORlDA
SS-u SS-l
NWPond Nursery Pond
Parameter ( u2/k2l -1!!L- 2/8'
Chromium
Lead 9,OOOJ -J
Mercury
Cyanide
Nitrate-Nitrite N
Toluene
Phenols
. 4,4'-ODT 9.6N
4,4'-ODO S3N
4,4'-ODE 120N 10
Chlordane
Gamma-Chlordane NA 30J
Alpha.- Chlordane NA 30J
. Material analyzed for but not detected.
J' Estimated value. .
N Presumptive evidence of presence of material.
NA Not analyzed.
~
-------
shallow aquifer; and three in the Floridan aquif~r.
previously installed shallow aquifer monitor wells,
and several temporary wellp::>ints were sampled. The
locations can be seen on Figure A-12.
In addition, six
various private welils
groundwater sampling
Surficial Aquifer
The nature of the groundwater contaminants found in the surficial Gquifer
is presented in Tables 4-24, 4-25, and 4-26. The tables include the
maxbnum concentration of each contaminant found in samples collected from
either the upper of lower well at each location. The maximum concentration
was used because the contaminants of interest were distributed throughout
the aquifer; and, if groundwater recovery is part of the selected alternative,
groundwater from the complete thickness of the aquifer would need to be
rerroved .
The presence of cadmium in the 1985 groundwater samples from wells at the
southern boundary and southwest of the site (6SA/SB, MW-3A/B, and MW-WB)
of Florida and to Southern Liquid Fertilizer/Douglass Fertilizer and
Chemical Company. This is substatiated by the presence of cadmium found
in the surface water samples collected from the large p::>nd on fertilizer
companies' property in 1981 and 1982, and the cadmium found in the surface
water samples collected from the Drum Service Company of Florida p::>nds in
1980.
The presence of arsenic in the groundwater samples collected from the
southern boundary of the site (MW-WB) appears to also be related to
past operations at the fertilizer companies or to past or present operations
at Drum Service Company of Florida. This is based on the presence of
arsenic in the groundwater beneath the two Drum Service Company of Florida
covered p::>nds. Aresenic was also present in lower concentrations in the
shallow groundwater beneath the abandoned drum area and the temporary
sludge storage area.
There was also a significant level of cyanide (200 mg/1) in the groundwater
samples collected southwest of the site (6SA/SBO and at the southern site
boundary (MW-lA/B). The concentration in the groundwater in these two
areas were an order of magnitude greater than in any other samples
collected during the RI. Since many soil and surface water samples were
considered not useable because of quality control, the source of the
cyanide in the groundwater cannot be determined. However, cyanide was
found in the shallow groundwater beneath both of the covered ponds used
by Drum Service Company of Florida in sbnilar concentrations to those
found in the groundwater at the upgradient well 3SA/SB.
The other trace metals of interest found in groundwater samples collected
dawngradient or on-site are chromium, lead, and mercury. The presence of
mercury has been detected in past studies in surface water samples. collected
from the Southern Liquid and Fertilizer p::>nd in 1981, in surface water
samples collected in 1980 from the ponds used by Drum Service Company,
14
-------
TABLE '-24
MAXIM UM CONCENTRATIONS OF SELECTED CONTAMINANTS IN CROUNDW A TER
5URF1Ci.\L AQUIFER DOWNCRADIENT OF LOCATJON,1
ZELL WOOD CROUNDW A TER CONT AMINA TION 51TE
ORANCE COUNTY, FLORIDA
~adient %sA/58 75A/58 Downgradient 6SA/58
15A/58 MW-IA/8 MW-3A/8
Parameter CUlt/I) 'la, 'la, 'la, 'la, 'la, 'la,
Chrom ium 22 44 102 18 4 92
Lead 440 ' 286 110 290
Mercury IJ O.4J 0.8:7
Cyanide 20,000J 200,000J 200,OO~j
Nitrate-Nitrite N 22,000 18 ,000 23,000 1,600 3,800 214,000
ToJuene ,J ,J ,J ,J
PhenoJs 10J . 10J
4,4'-00T
4,4'-00E .09
4,4'-000
ChJordane
Ammonia 330' lJ ,000 770 18 ,000 328 ,oog
Total Phosphorus 32~ 69 78 '730 270 1',000
Cadmium 24 11 10
Arsenic 46
J
Material was analyzed for but not detected.
Estimated vaJue.
-------
TABLE '-2.5
MAXIMUM CONCENTRATIONS OF SELECTED CONTAMINANTS IN GROUNDW"'TER
SURFICIAl AQUIFER DOWNGRADIENT OF LOCATION.
ZELLWOOD CROUNDWATER CONTAMINATION SITE
ORANCE COUNTY, FLORIDA
UPI"~d;ent Downgr'ildient
-SA/sa 7SA/S8
Parameter (~/J) '18' 'I"
Chromium 13 1C2
Lead UO 44:;
Mercury IJ
Cyanide
Njtrate-~itri!e ~ 300 23,~~C
Toluene ,J
Phenols 10J 10J
4,4'-DDT
4,4'-DDE
4,4'-DDD
Chlordane
A:'11monia 160 11,00C
Total Phosphorus 2,8'0 78
Cadmium
Arsenic
Materia! was analyze-: for but not detected.
Estimated value.
J
'.
-------
TABLE '-26.
MAXIMUM CONCENTRATIONS OF SELECTED CONTAMINANTS IN GROUNDWATER
- SURFICIAL AQUIFER DOWNGRADIENT OF LOCATION 3
ZELL 1'00D GROUNDW A TER CONT AMINA TION SITE
ORANGE COUNTY, FLORIDA
YEP'adjent ;SA/S8 [)oW1'l~radjent &SA/S8
)SA/S8
Parameter (~/t) "I' "I' ,'as
Chromium 17 110 92
Lead 290
Mercury 0.8'
Cyanjde 20,000' 2~=,O~Cj
Nitrate-Nitr ite N 7,000 300 214,0:0
Toluene '.1
Phenols 10'
4,4'-DOT
4,4'-00E
4,4'-DOO
Chlordane :-
Ammon ia 12~ 328 ,O~O
Total Phos?norus 330 1"10 1',0:0
Cadmjum 10
Arsenic:
Material ....as analyzed for but not detec:ted.
. .
.
-------
and i~ shallow groundwater samples collected downgradient of the abandoned
drum area in 1981. During the RI, mercury was found in significant
concentrations in the abandoned drum area in the samples collected from
both the surface and subsurface soils. Mercury was also found in shallow
groundwater samples collected in 1985 beneath the abandoned drum area,
temporary sludge area and both covered ponds as well as the groundwater
southwest (~3A/B and 6SA/B) and west of the site (7SA/B).
The presence of chromium and lead was found throughout the site. The
highest concentrations of lead (an order of magnitude greater) found
during the RI were in the samples collected from the sediment of the
large pond in abandoned drQm area. Chromium was found in the greatest
concentration in the soil samples from the abandoned drum area and in the
sediment samples from the fertilizer companies' ponds. Chromium was also
found in the groundwater concentrations (7SA/SB, 5SA/SB, 6SA/SB) as well
as in the shallow groundwater drum area. Lead was found in the groundwater
samples collected at the southern boundary of the site (MW-IA/B) as well
as west and southwest of the site (7SA/SB, ~3A/B: and 6SA/SB) and
beneath the abandoned drum area and the two covered ponds.
Many organics were found in the groundwater ,)n and downgradient of the
site. The presence and concentration of both pur~eable and extractable
organics is greatest in the groundwater samples collected beneath the
Drum Service Company I s former perculation ponds. Many of the organics
found in groundwater samples beneath and downgradient of the site are
contaminants that are present in (~ither the subsurface soil samples from
the abandoned drum area or in the subsurface soil samples from the covered
ponds. This indicates that these contaminants may still be leaching and
mi~ratinq to the surficial aquifer. Some of these contaminants have
~igrated at least as far as the southern boundary of the site (MW-IA/B).
The ~roundwater samples containir~ the highest overall level of contamination
Here collected southwest of the site from monit')r well 6SA/SB. The
concentrations of nitrate-nitrite, ammonia, and phosphorus were all an
order of magnitude greater than in other samples. These high concentrations
are associated with fertilizer production and are apparently coming from
the old Southern Liquid Fertilizer/Douglass Fertilizer ponds or past
operations at that facility.
Volume of Contaminated Groundwater in Surficial Aquifer
The distribution of the contaminants in the surficial aquifer beneath and
downgradient of the site suggests that groundwater contaminants have
migrated to at least the location of well 6SA/SB. Using the chemical
analyses and travel times described above, an estimate was made of the
potential horizontal extent of t;Jt"oundwat.er contamination attributable to
the site. Figure 4-14 shows the region approximating the areal extent of
groundwater contamination in the surfidal aquifer. The groundwater.
beneath abandoned drum area and tempora~l sludge storaJe is included in
the region because these areas received an unknown quantity of waste
15
-------
POTENTIAL
CONTAMINATION
APPROXIMATE EXTENT OF GROUNDWATER CONTAMINATION
SllRFICIAL AQUIFER
ZELLWOOD GROUNDWATER CONTAMINATION SITE
ORANGE COUNTY, FLORIDA
FIGURE 4- 14
-------
material and contaminants still exist in the subsurface soils. In
addition, contaminants were detected in the shallow groundwater immediately
beneath each area.
Based on the chemical analyses, contaminants were found throughout the
vertical extent of the surficial aquifer. Therefore, the vertical
estimates of contaminated groundwater were based on the aquifer thickness
of 40 feet.
Floridan Aquifer
The nature of the groundwater contaminants found in the Floridan aquifer
.is presented in Table 4-31. The tables include the maximum concentration
of each contaminant of interest and its location, and the presence and
location of the organics found in the Floridan aquifer. An evaluation of
the data showed that several critical contaminants were present.
~ direct correlation between the site contaminants and the contaminants
in the Floridan aquifer cannot be made; however, it is not inconceivable
that the contaminated groundwater in the surficial aquifer is reaching
the Floridan aquifer through sinkholes, through areas where the confining
layer is not continuous, or through improper construction techniques used
to install industrial and/or drinking water wells into the Floridan
aquifer.
The EPA, Water Supply Branch, requested that wells IW-2, I~4, IW-5, I~6,
I~8, PW-10, and ~12 be resarnpled because of the potential health risk
of drinking water with the concentrations of the contaMinants detected
during the RI. All of these wells were screened in the Floridan Aquifer.
The wells were resampled by EPA in December, 1985 and analyzed and the
well owners were advised by EPA that the results showed no contaminants
3t concentrations that would pose a significant health risk.
Air Investigation
No air samples were collected during the RI, but under normal conditions,
it is unlikely that particulate or volatile contaminants would present
much of a threat to the nearby residents or workers. Strong winds, heavy
equipment operation, or continuous truck traffic within the site could
expose contaminated surface soils to airborne transport. 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
~ould occur only during times of heavy truck traffic within the drum
storaqe ares.
16
-------
TABLE .-31
MAXIMUM CON CENTRA TJON OF SELECTED CONTAMINANTS IN GROUNDWATER
.' FLORIDAN AQUIFER 1985
ZELL WOOD GROUNDWATER CONT AMtNA nON SITE
ORANGE COUNTY. FLORIDA
'
Parameter Concentration (yg,ffi, Loc:ation(s)
Chromium 96 10
Lead '0 10
Mercury 2.2 IW-2
Cyanide
Nitrate-Sitrite N 200 10
Toluene ,J 10,70
Phenol 24 ID
4,IJ'-DDT
",4'-00E
",4'-00D
Ammonia 2,100 1\\' -6
Phosphorus 1 ,'00 IW-6
Chloride 330,000 IW-6
Iron 190,000 30
SHver ,J IW-2
.
-------
SUBSURFACE INVESTIGATION
Test Boring Program
A test boring program was instituted at the Zellwood Groundwater
Contamination Site to characterize the site geologically and to determine
intervals tor well screens prior to well installation. 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 whichever was less. The confining Hawthorn
Formation was not penetrated at location number two because of the
suspected levels of contamination in this area.
Well logs were used to develop cross sections to illustrate the geology
on and around the site. Figure 4-3 shows the location of cross sections.
Figure 4-5 shows a fence diagram encompassing the site that was developed
using wells logs from all test boring locations.
ROUTES OF TRANSPORT AI\JD POTE~TIAL RECEPTORS
Surface Water and Sediment/Soil
Surface water features at the site include several ponds and three
distinctive draina~e pathways referred to as the northern, middle, and
southern ditches. Surface water run-off at the site is either confined
in the ponds or is channeled to one of the ditches. Although site drainage
is to the ~est 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 dry containing only isolated
areas of stagnant water. The southern ditch contains a fairly constant
flow of water, since it receives a direct discharge and run-off from the
Zellwin Fapns large paved parking lot.
Several inorganic and organic constituents were detected in both the
surface water and sediment samples. The inorganic constituents include
arsenic, zinc, and mercury, which was detected in sediment samples from
the northern ditch; mercury was also identified in sediment samples from
the southern ditch. Many extractable organic compounds associated with
coal tar derivatives were identified in samples from the southern ditch.
17
-------
i .
.
00 rJ 0
o g
CJ
00.0 00 0
~ ,...-
0----.
~._O-O
. ---. .......
.-.
I
,
.~
:+~8-
/0
o
.\o_._._._._._.~.,.,.
. \
I
[}
. .
o
lit
I.EOEHD
,.-. - Tea, 8011..0
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a
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...
.................... --.~_.
I
~
C:l
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L
i ,
J .
_0-1
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'AII.a-T'8-'
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.
.
8C.".
. ..~
.
..,
.
.~........- ......-
CROSS SECTION AND FENCE DIAGRAM LOCATION
ZELLWOOD GROUNDWATER CONTAMINATION SITE
ORANGE COUNTY. FLORIDA
FIGURE" -3
-------
HORIZONTAL SCALE
VERTICAL SCALE
TB-f
LEGEND
£3 SANDY t 8ILTY SAND
§ CLAYEY SAND
Q SANDY CLAY
£§ SANDY CLAY WITH PHOSPHATE
§ANOY CLAV *
2 WHITE RESIDUAL LIMESTONE
^ SANDY CLAY I SHELL FRAGMENTS
__ SURFICIAL DEPOSITS / HAWTHORN
CONTACT
— HAWTHORN / OCALA CONTACT
? WHERE APPROXIMATE
FENCE DIAGRAM
ZELLWOOD GROUNDWATER
CONTAMINATION SITE
ORANGE COUNTY, FLORIDA
FIGURE 4-5
-------
Six of these compounds were also detected in the southern fork of the
northern ditch. It is possible that the heavily paved area around the
Zellwin Farms Company packaging house or the Jones Avenue asphalt road
are contributing these contaminants via surface water run-off. The water
samples from,the ditches also contained numerous inorqanic and organic
constituents; DDE was detected in all three ditches.
The samples from the two ponds located in the abandoned drum storage area
exhibited the highest concentrations for several organic compounds'
including toluene.
Surface soil samples collected from the drum storage area contained many
inorganic constituents including chromium, lead, and mercury. Several
organic compounds associated with wood preserving chemicals were detected
in the surface soil sample collected along the northern end of the site
on the souths ide of the Seaboard Coastline Railroad tracks. These
compounds may be leaching out of the railroad ties into the surrounding
soils.
Groundwater,
.
The movement of contaminants through the groundwater (surficial and
Floridan aquifers) is one of the major transport routes of concern at the
Zellwood Groundwater Contamination Site. Groundwater flow rates, direction,
and hydrogeologic parameters affecting contaminant migration were defined.
Several heavy metals and a few organic compounds were detected in. the
groundwater samples collected from the surficial aquifer monitor wells.
Chromi~, cyanide, nitrate, and mercury are among the inorganic constituents
detected; toluene, chlordane, and trichloroethene are examples of some
organic compounds identified. Although a direct exposure to the contaminants
in drinking water wells is unlikely, human and biotic receptors could
come in contact with the chemicals where the groundwater discharges to
surface waters or as a result of shallow excavation downgradient of the
site. The Floridan aquifer has shown no contaminants which could be
related to site activities.
Air
Under normal conditions, it is unlikely that particulate or volatile
contaminants would present much of a threat to the nearby residents or
workers. 'However, strong winds, heavy equiprent operation, or continuous
truck traffic within the site could expose contaminated surface soils to
airborne transport. Harmful acute exposures to any of the contaminants is
very unlikely. For chronic exposures, there would have to be a constant
disturbance of the soil over a long time period. The changes of this
occurring are likewise very minimal.
18
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SECTION V
REMEDIAL ALTERNATIVES
SCREENING OF RE~1EDIAL TEC~OU:X;IES
Numerous technoloqies are available for use at the Ze1lwood Groundwater
Contamintation Site. Although many are applicable, it is apparent that a
number of technologies can be removed from further consideration based
on the information obtained about the site from the remedial investigation
(RI) .
Screening began during the RI as information on the site conditions was
obtained, and a list of preliminary, applicable technolgies was developed.
This list comprises actions that address the potential site problems and
pathways of contamination identified during the RI:
o
No action
No action - monit0ring
Alternate water supply
Capping
Regrading and revegetation
Groundwater barriers
Groundwater recovery
Sediment and surface water removal
Excavation
Waste pile removal
In-situ treatment
Surface water and groundwater treatment
Incineration
Disposal technologies
o
o
o
o
o
o
o
o
o
o
o
o
o
Each technology has been reviewed in accordance with the following three
criteria:
o
Effectiveness
Implementabil i ty
Cost
o
o
During the initial screening, the investigation team and other personnel,
with experience in various applicable disciplines, reviewed and evaluated
the results and conclusions of the RI. The technologies identified during
the RI, as well as technologies encompassing treatment or disposal which
19
-------
were thought to be of importance, were discussed and evaluated. I~ same
cases, there are'several technologies that are similar to each other, such
as the various technologies' used for an alternate water supply. In these
cases, an evaluation was performed to determine which technology was most
appropriate for the Zellwood Groundwater Contamination Site.
Tables 2-1 through 2-6 contain the technologies that were initially
screened. These tables also contain the reasons why the various
technologies either passes or failed the initial screening. The tech-
nologies that passed the screening were then grouped into a series of
nine remedial alternatives. The nine remedial alternatives were developed
in accordance with the National Contingency Plan exhortation to develop a
series of alternatives that show: ,.
1)
alternatives for treatment or disposal at an off-site facility
as appropriate:
2)
alternatives that attain applicable or relevant and appropriate
Federal public health and environmental requirements;
3) . alternatives that exceed applicable or-relevant and appropriate
Federal pUblic health and environmental requirements;
4)
alternatives that do not attain applicable or relevant and appropriate
Feder~l public he~lth and envir~~ental requirements b~t will reduce
the likelihood of present or future threat from the hazardous substance
and that provide significant protection to pubiic health and welfare
and the environment. This must include an alternative provided by the
applicable or relevant and appropriate requirements;
5)
No action alternative.
The remainder of the section will discuss in detail the nine alternatives.
ALTERNATIVE 1 - No Action - Monitoring
. .
If this alternative were implemented, a long term groundwater monitoring
program would be established to provide information on contaminant movement
and exposure to humans and the environment. The monitoring would be
performed on a quarterly basis for the first three years, at which time
the progra~ would be re-evaluated.
20
-------
TABLE 2-1
TECHNICAL SCREENING
Al TERNA TE WATER SUPPLY TECHNOLOGY
ZELLWOOD GROUNDW ATER CONTAMINATION SITE
ORANGE COUNTY, FLORIDA
,.. .
.'" . -
Alternate
Water Supply
Technology
Retained for
Further
Evaluation
- ..
Comments
Municipal Water Supply
Extension
Yes
Most complete and reliable;
no moni~oring req'Jire:
Bottled Water
Yes
Short-term solution
Individual Treatment
Uni ts
No
Requires extensi ve
monitoring and maintenance
.
-------
TABLE 2-2
TECHNICAL SCREENING
CAPPING TECHNOLOGY
ZELLWOOD GROUNDWATER CONTAMINAnON SITE
ORANGE COUNTY, FLORIDA
,.. .
Surface Cappin~ Technology
Retained for
Further Evaluation
- ..
Comments
Clay
Yes
Used extensi :vely
Synthetic Mem'brane
Yes
Used extensi vely
Concrete and Asphalt
No
Susceptible to cracking
Soil MiXtures
No
Limited experience
. .
.- .0._. .
-------
TABLE 2-.3
TECHNICAL SCREENING
GROUNDW ATER BARRIERS
ZELLWOOD GROUNDW ATER CONTAMINATION SITE
ORANGE COUNTY, FLORIDA
Groundwater Barrier
Technology
Retained for Fw-ther
Evaluation
Comments
Slurry Wall
Yes
Demonstrated performance
Sheet Piling
No
High cos t *
Grout Curtain
No
Potential for gaps to occur
during curtain placement
* in comparison to the slurry wall technology
I "I
I :
I
I I
I
-------
---
TABLE 2-4
TECHNICAL SCREENING
SURF ACE WATER AND GROUNDW A TER TREATMENT TECHNOLOGIES
ZELLWOOD GROUNDWATER CONTAMINATION SITE
ORANGE COUNTY, FLORIDA
Water
Treatment Technology
Retained for
Further Evaluation
Flow Equalization
Yes
Precipitation, Flocculation,
and Sedimentation
Yes
Fll tration
Yes
.
Carbon Adsorption
Yes
Ion Exchange
Yes
Chemical Oxidation
Yes
Acti vated Sludge
Yes
Anaerobic contaCt/anaerobic filter
Yes
Oxidation ditch
Yes
- .-
,.. .
-
- ..
Comments
Promotes process stability
Metals and inorganics
rem oval
Suspended solids removal
Organic chemical removal
Nitrate removal
Cyanide removal
Organics, metals, and
nitrogen removal
Organi cs, metals, and
nitrogen removal
Organics, metals, and
nitrogen removal
-------
Incineration Technology
Fluidized Bed
Multiple Hear.h
Cement Kiln
Lime Kiln
Rotary Kiln
.
TABLE 2.'
TECHNICAL SCREENING
INCINERA nON TECHNOLOGY
ZELLWOOD GROUNDW A TER CONT AMINA nON SITE
ORANCE COUNTY, FLORIDA
,-. .
.
Retained for
Further Consideration
Com"ment
No
Limited experience
No
Not appropriate for was.es
requiring high temperatures
No
Not appropriate for hazardous
waste
No
Not appropriate for hazardous
waste
Yes
Applicable for variable liquid
and solid wastes
-------
TABLE 2~
POTENTIAL REMEDIAL TECHNOLOGIES
ZELLWOOD GROUNDW ATER CONTAMINATION SITE
ORANGE COUNTY, FLORIDA
Technology
Passed
Initial
Screening
-' . .
Site Remediatian:
No ACtion Technologies
No
Monitoring
Yes
Alternate Water Supply
(Extension of Municipal Water Lines and
Bottled Water)
Yes
Capping
(Synthetic and Clay)
Yes
Regradin2 and Revegetation
No.
'Groundwater Barriers
Yes
..
Croundwater Recovery
Yes
Sediment and Surface Water Removal
. Yes
£xcavation
Yes
Waste Pile Removal
Yes
In-situ Treatment
(Soil Fl1/Shin2)
Yes
~
Treatment of Removed Materials: .
Surface Water and Groundwater Treatment
Yes
Incineration
(Rotary Kiln)
Yes
Disposal of Removed Materials:
Ofbite Disposal
Onsite Disposal
Yes
Yes
.
Ancillary to primary technologies
,- 00
o .0
Passed
Further
Screening
Yes
No
Yes
No
Yes
Yes
Yes,
Yes
Yes
Yes
Yes
Yes
Nn
-------
Effectiveness
Implementation of this alternative would not reduce or eliminate any of the
impacts resulting from the site contaminants. It would be effective in
providing information about the movement of the contaminants, so that future
remedial actions could be taken if necessary. The monitoring system should
last the effective life necessary to complete the objectives of this
alternative.
The major safety risk involved in implementing this alternative would be to the
workers constructing the two new groundwater monitor wells. Continuous
monitoring during construction would prevent exposure to hazardous substances.
There should be no threat to any private residents or workers at or near the
site.
In addition to the sampling personnel under the no action alternative, there
would be workers involved in the construction of two new groundwater monitor
wells. These remedial personnel could be faced with possible deleteriou s
effects as a result of inhalation of volatile contaminants. However, if
continuous air monitoring activities were performed, risks associated with the
implementation of this alternative could be controlled. Based on previous
experience with these activities, the duration of exposures would be very short
and exposure levels could be adequately controlled to below acceptable levels
by existing, readily available technologies. The excess risk 'of cancer,
chronic health effects, and acute health effects could be minimal and therefore
not a factor in the implementation of monitoring activities.
For the' purpose of evaluating public health risks from the release of hazardous
substances from the site, it was necessary to select certain chemicals for
evaluation. These indicator chemicals are those that are considered to
contribute most significantly to the risk of endangering human health. The
procedure used to select the indicator chemicals was outline in the draft
guidance document prepared for the EPA, Superfund Public Health Evaluation
Manual (lCF, 1985). The maximum concentration of each of the indicator
chemicals detected in various sampling media during the RI is shown on Table
4-1.
Groundwater is the principal environmental transport medium for contaminants
originating from the Zellwc:xxj Groundwater Contamination Site. During the RI,
high levels of contaminants were found in the surficial aquifer both on- and
off-site. The contaminants were detected in samples taken from permanent
groundwater monitor wells and temporary well points. The risk associated with
the site is dependent on both the hazard of the specific chemicals and the
potential for exposure. Presently, there are no known points of potential
human exposure through ingestion of contaminated groundwater. The surficial
aquifer flows to the southwest and eventually discharges to Lake Apopka or to
the canals which flow into Lake Apopka. There are no known wells finished in
the surficial aquifer between the site and Lake Apopka.
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There are many possible scenarios which CQuld provide a point of exposure
for humans to the contaminated groundwater. For the purposes of this
investigation and to illustrate the levels of contaminants found during the
RI, a "worst case" situation is developed below. The worst case would be
for a well, utilized for potable water, to be set in the most contaminated
area of the surficial aquifer. Based on the concentrations shown on
Table 4-1, the cancer risk associated with drinking two liters of water
per day for seventy years if approximately 6 x 10-1. This cancer risk is
based entirely on the high levels of arsenic found in the groundwater
collected from shallow well points located on-site. It should be noted
that because groundwater samples are not filtered, the concentration
detected may not represent the concentration which is actually moving in
the groundwater. .
Another possible worst case scenario could occur if excavation were to be
performed downgradient of the site. Since the water table is only 4 to 6
feet below the ground surface, excavation could expose contaminated
groundwater. using the maximum concentration of cyanide [200 milligrams
per liter (mg/l)] found in the groundwater at monitor well location 6, a
quantity of approximately 4.8 ounces could be lethal. This quantity was
estimated based on the LDLo for cyanide at 2857 micrograms per kilogram
(ug!kg)' (Sax, 1981) and a 10 kg (child) body weight. It is not impossible
for a child to fall into a samUl body of water formed during excavation
and for several ounces of water. to be ingested.
Surface water is another principal medium for humans to be exposed to at
the site. Surface water was present in both ponds and ditches. Since it
is highly unlikely that a~y of surface'water bodies will be used for a
li.fe-time drinking water source, it is more appropriate to look at surface
water as providing an accidental exposure and therefore acute toxicity.
Based on surface water samples obtained during the RI, there are no known
chemicals present at sufficient concentrations to cause acute toxicity.
The surface soil, sediment and waste piles provide an additional contaminated
media for potential exposure on-site. Since the site is accessible to
humans, contact is possible. In order to estimate a potential risk for
ingestion of soil, assumptions were made based on studies performed by
the Centers for Disease Control (CDC). A child courd ingest approximately
0.1 to 1 gram of soil per day for about five years. Since the most
contaminated soil areas exist in the abandoned drum area, and accessibility
is easily accomplished, ingestion of 0.1 gram per day and a 20 percent
availability factor were used in the risk calculation. The risks. are
summarized on Table 4-2. This table represents a worst case analysis and
assumes a shield would ingest 0.1 gram of soil each day for five years and
that 20 percent of the time the soil would be from the area on-site
found during the RI to be the most ontaminated. As shown on Table 4-2,
arsenic has the highest risk.
The remaining residual risk associated with the no-action alternative is
the potential for a change in the existing levels of risk, due to changes
in the concentrations of chemicals that the receptors are presently
experiencing. Since the groundwater is to only media expected to have
22
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any potential for migration, the proposed monitoring program would
provide information regarding changes in contaminant concentration.
The no action alternative would provide no protection to the regional
ecolo~y from the conditions as they presently exist. The groundwater
will eventually discharge into Lake Apopka or the canals which flow into
Lake Apopka. The approximate volume of Lake Apopka is 5 billion gallons.
This would create a dilution factor of about 2.5 million to 1. Using the
maximum concentration of cyanide observed in the groundwater and assuming
it is uniformly distributed throughtout the full extent of the aquifer at
the same concentration, the concentration of cyanide after dilution in
Lake Apopka (under worst case conditions) could not exceed 0.02 nanogram/liter
(ng/l). There is a possibility for environmental receptor toxicity to
occur if the receptor were to came in contact with undiluted concentrations
of a contaminant, but this is not considered likely because of dispersion
and advection of the groundwater contaminants over the large area.
Implementability
This alternative could be impl~ented quickly with little difficulty.
Two new groundwater monitor wells could be installed in approximately one
week at the downgradient location. Existing monitor wells or private
wells could be used for the other monitoring locations.
Implementing this alternative would require workers skilled in taking
representive groundwater samples from monitor and existing private wells.
Such workers are readily available. Historically, monitoring has proven
to be a reliable method for determining concentrations of contaminants in
groundwater. Operations and maintenance considerations would include
inspection of the wells and quarterly sampling and analyses of the
groundwater.
Implementing the monitoring portion of the no action alternative should
create no negative environmental impacts. Sa~pling of groundwater monitor
wells and private and industrial water supply wells would be the only
actions. Generally, environmental sampling of this nature is an unobtrusive
exercise which, if executed conscientiously, should not pose a threat to
the regional environment.
23
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This alternative could be implemented without having to obtain any oermits
or other regulatory approvals; however, it would not satisfy any applicable
or relevant and appropriate requirements. It would be necessary to make
arrangements for an agency to conduct the sampling, analysis, aod
interpretation of data.
Implementation of this alternative would provide responsible agencies and
the public with information on the location, magnitude, and potential
~pact of the contamination from the Zellwood Groundwater Contamination
Site. It would not correct any problems at the site and consequently
would not address 'any concerns which the agencies or the public might
have regarding the site.
Land use restrictions would also be necessary to prevent well installation
in the surficial aquifer downgradient of the site.
Cost
Capital costs for constructitYJ two groundwater monitor wells woula be
$12,000. Operation and maintenance costs were included with this
. alternative to inspect the monitor wells and provide quarterly groundwater
sampling and analyses. The number of groundwater samples taken each year
was assu~ to remain constant at 64 and monitoring was assumed to occur
annually for thirty years. For the first three years, the groundwater
would be analyzed for the hazardous substance list of contaminants, and
then the proqram would be re-evaluated. For purposes of costing, it was
also assumed that analyses would cost $500 per sample for all samples
collected after the third year. This would result in an estimated annual
operation and maintenance cost for the first three year of $102,720 and
for years four through thirty of $48,960.
ALTERNATIVE 2 - Monitoring and Waste Pile Removal
If this al ternati ve were implemented, a m6ni tdring 'program for groundwater'
would be established in addition to the removal of the waste piles located
in the northern section of the abandoned drum area.
The evaluation of the monitoring program applies to this alternative as
well. This section only presents the evaluation of the removal of the
waste piles. '
Effectiveness
If the waste area were removed, no maintenance would be needed, since the
source of contamination would be elUninated.
24
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The residual risk of this alternative would be almost identical to the
residual risk of the previous alternative. The only change would be that
the two waste areas would no lo!p]er be an eXPJsure PJint or provide a
future source of contaminants to groundwater or surface water.
Some decrease in environmental impact would result from removing the
waste piles. The analyses of the soil/waste from these two areas indicate
high levels of various contaminants, and the surrounding area showed
little or no vegetation.
Implementability
The major risks added to this alternative would be those incurred by
handling and transPJrting contaminated soil trom the waste piles.
Monitorinq of these area was performed during the RI with an HNU and no
readings above background were recorded. However, high concentrations of
many or~anics and many inorganics, such as mercury, would suggest that
precautions should be taken. The period of eXPJsure would be short, which
would tend to decrease the risks of chronic health effects. Any risks
associated with exposure should be controlled by readily available and
proven control technolgies.
Nearby off-site public receptors could be eXPJsed during transportation
of wastes to an off-site facility. Since it should take only one truck
to haul the wastes, no significant risk should be incurred. .
Impacts on local and regional environmental receptors during implementation
of this .alternative would be negligible if good work practices are
employed.
All previously discussed institutional r8quirements would apply to this
alternative. In addition, the RCRA regulations set forth in 40 CFR Part
263, "Standards Applicable to Tranporters of Hazardous Waste" would apply
to the transportation of the wastes if the waste piles were removed.
Tranparters are required to obtain an EPA identification number from the
EPA Administrator prior to the movement of the material, and the material
must be registered in accordance with the manifest system requirements.
Cost
The capital costs for this alternative would be $22,000. This includes
the cost for removal and disposal of the two waste piles which was
estmiated at $10,000. Detailed costing information can be found in
Appendix F.
The present worth value of the total costs for 30 years at a 10 percent
~iscount rate would be $617,000.
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A five percent sensitivity factor was included for the capital costs for the
waste pile clean-up because of the volume to be removed. This would cause the
total costs to vary from $568,000 to $691,000.
ALTERNATIVE 3 - Monitoring, Waste Pile Removal, Groundwater Recovery, Water
Treatment, and Soil Flushing
If this alternative were implemented, the monitoring prog ram would be
established and the waste piles would be removed. Also, the contaminated
groundwater would be removed, treated, and then flushed though the abandoned
drum area.
The evaluation of the previous alternative' also applies here. This section
only present the evaluation of groundwater removal, treatment, and flushing of
the abandoned drum area.
Effectiveness
Groundwater recovery through the use of pumping wells is a proven technology.
An extraction well system could also'effectively control the migration of
contaminated groundwater. If periodic operation and maintenance requirement of
the recovery systems were met, the system should last the effective life
necessary to complete the objectives of the alternative.
The two alternate groundwater treatment systems proposed for this alternative
are composed of unit processes which nave proven their performance in many
water and wastewa~er treatment applications. The use of either of these
systems would provide a higi') level of public health and environmental
protection by removing the majority of contaminants associated with the
groundwater in the surficial aquifer. The groundwater treatment process would
continue until appropriate ARARs are met or until the determination has been
made that further treatment would not be effective.
The effectiveness of soil flushing is very site and contaminant specific. This
technology would prove beneficial for removal of sparingly soluble compounds.
In addition, the reintroduction of treated water would decrease the time
required for aquifer remediation by increasing the rate of groundwater flow in
the surficial aquifer. The useful life of this system should far exceed the
time required for groundwater treatment.
Either treatment system described would effectively eliminate the contaminants
associated with the groundwater in the surficial aquifer. Reclamation of this
aquifer would prevent vertical migration of the contaminants to the Floridan
aquifer as well as off-site migration to nearby surface waters. Residual risks
would center around those contaminants associated with the subsurface soils.
These sparingly soluble contaminants could be released, at various rates,
following the cessation of the groundwater removal process. The inclusion of
soil flushing in this alternative would address the majority of ,this problem.
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The remaining risk, soil ingestion, would be identical to that found earlier.
As discussed earlier, the risk involved with soil ingestion is estimated from
the maximum concentrations observed, but soil ingestion is considered unlikely.
A significant decrease in the potential risk of harmful environmental impacts
would result from the recovery of contaminated groundwater. The reduction in
environmental risk would also be true for this alternative. Negligible risk
would remain if this alternative is implemented.
Implementability
In-situ treatment processes are not as well developed or demonstrated as other
more conventual technologies. Of the various in-situ technologies, soil
flushing has been shown to be one of the more effective and easily
Implementing the soil flushing technology at the site should not present a
problem. The benefits of the system would be facilitated by the relatively
shallow depth of contaminated soil (4 to 6 feet). The time required for
installation of the spray irrigation system should be short.
The materials and components needed to construct a pumping system are readily
availab le. Construction of the wells would require experienced d rille rs.
Constant monitoring for vapors would be necessary during drilling. The well
installation should be completed in a six-month period. Scheduling of
materials and labor would have to be planned so that they were available
on-site when needed.
No factors should affect the construction of the treatment facility. The
majority of the unit processes in either treatment system could be bu ilt above
ground. The time required for implementing the water treatment portion of this
alternative could be extensive. Prior to construction, it would be necessary
to conduct laboratory and possibly pilot scale studies to obtain information
necessary to design the full scale facility. Following the construction, the
system could be put on-line.
Both .treatment systems, particularly treatment system one, wou ld requ ire
chemical handling during their operation. In addition, the potential would
exist for plant operator exposure to the groundwater contaminants. In both
instances, worker risk should be minimal and easily controlled using standard
safety procedures.
Pumps would need to be inspected at regular intervals to detect any wear or
deterioration because of contact with contaminated groundwater. Flow rate
analyses and inspections should also be conducted regularly. The analyticaJ
equipment, flow rate equipment and methods of inspection are readily
dvailable. Groundwater recovery systems utilizing pumping wells have been
studied and used in controlling contaminated groundwater migration at other
sites.
27
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Impacts on local and regional environmental receptors during implementation of
this alternative would be minimal. However, any treated water that would be
discharged has the potential to impact on the environment. This impact would
stem from trace levels of contaminants and nutrients which might be present in
the effluent. Nutrient levels are of particular importance since the water
will ultimately discharge to the already euthrophic Lake Apopka.
Implementation of this alternative would require permits from the State for the
removal of the groundwater and the installation of the wells. Any point source
discharge from -the treatment facility may be regulated under the Clean Water
Act (CWA). In addition, transportation of the solids to an off-site RCRA
landfill would be subject to 40 CFR Part 263, "Standards Applicable to
Transporters of Hazardous Waste".
Cost
The Capital costs for this alternative would be $6,684,000. The capital costs
for the groundwater recovery system and soil flushing would be $33,000 and
$432,000, respectively. As described in the Feasibility Study, two treatment
schemes would be feasible for this site. The capital cost for treatment system
1 would be $6,197,000, and the cost for treatment system 2 would be
$2,570,000. All the following costing tables contain only the costs for the
first treatment system.
Operation and maintenance costs would include experienced personnel for the
groundwater treatment plant. The annual operation and maintenance costs for
treatment system 1 and treatment system 2 would be $302,000 and $258,000,
respectively. Again, only the cost for the first treatment system is presented
on all the following tables. Routine inspections would also be necessary for
both the recovery system and the soil flushing program. The present worth
value of total costs for 15 years at a 10 percent discount rate would be
$9,638,000.
A twenty percent sensitivity factor was included for the capital costs and
operation and maintenance costs for the groundwater recovery system, treatment
plant, and soil flushing programs because of the various assumptions which were
made in calculating the volume of water necessary for treatment and the extent
of contaminated soils. This analysis resulted in a variation in total present
worth costs from $7,832,000 to 11,469,000.
Analysis of the Alternatives that Attain Applicable or Relevant and Appropriate
Federal Public Health and Environmental Requirements
ALTERNATIVE 4: Monitoring, Waste Pile Removal, Groundwater Recovery, Water
Treatment, Sediment and Surface Water Removal, and Gapping
If this alternative were implemented, the monitoring program, removal of the
waste piles, the groundwater recovery system, and the water treatment
28
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process discussed earlier would ~ established. The sediment and surface
water would be removed fram the contaminated areas in the northern,
middle, and southern ditches, the Douglas Fertilizer ponds, and the two
ponds in the southwest section of the abandoned drum area. Disposal of
the sedime~ts at an approved facility would be necessary under this
alternative. Also included would be the capping of the abandoned drum
area.
The eVqluations of the previously described technologies also apply here.
This section only presents the evaluation of sediment and surface water
removal and capping the abandoned drum area.
Effectiveness
Caos. have been demonstrated to be an effective method of minimizing the
infiltr~tion of surface water or rainwater. Regrading and revegetation
would assist in rAducing the volume of water that reaches the cap barrier.
The expected design life of the proposed cap system would be required to
insure cap inteqrity. \vith proper upkeep, the cap could last indefinitely.
Dredging and pumping would be effective in removing the sediments and
surface waters onsite. The depth of surface water in the ditchlines is
relatively shallow (less than 1 foot), which should permit efficient
removal of the contaminated surface water and sediment. The location of
the ponds would allow for easy access for pumping and sediment removal
equipment.
The alternative addresses all the contaminated media discussed earlier
where potential human contact could occur. The only remaining areas with
contamination not remediated are several low level subsurface soil areas
where there should be little to no potential for exposure.
.~l potential environmental impacts associated with contaminated surface
water and sediment and contaminated surface soils in the abandoned drum
area would ~ eliminated by implementing this alternative.
Dmplementability
The techniques required for the removal of the sediment and surface water
would involve standard and well proven construction practices. The
ability to locate a party to complete this work should not present a
problem and costs would be relatively low.
The theoretical amount of time required for removing the 2,430 cubic
yards of sediment, at an excavation rate of 1,043 cubic yards per day,
would be approximately three days. The time requirement would be extended
due to pond draining, sediment dewatering, and equipment relocation ~ut
29
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this should be minimal. Beneficial results from the implementation of this
technology would occur immediately following completion.
Operation and maintenance procedures for the cap would be minimal, requiring
routine inspection and repair of erosional effects and subsidence. Cover top
maintenance would be modest, consisting primarily of preventing undesirable
species from becoming established and penetrating the cap.
There are no factors which should prevent the completion of this alternative.
The ability to locate a source for cap components should not present a
problem. Time required for cap installation would be approximately nine
months.
Impacts on local and regional environmental receptors' during Implementation
would be negligible if good work practices are employed.
Cost
The total capital costs for this alternative would be $8,531,000. The capital
costs for capping and sediment and surface water removall and disposal would be
$1,292,000 and $987,000, respectively.
.
No operation and maintenance costs should be incurred for sediment and surface
water removal. The operation and maintenance costs for capping would include
inspections and cover crop maintenance. The annual operation and maintenance
costs would be $768 and the present worth of the total costs for 30 years at 10
percent rate would be $11,461,000.00.
A ten percent sensitivity factor was included for capital costs for capping and
the surface water and sediment removal since both the areas to be capped and
the volume of surface water and sediment to be removed could vary. This
analysis resulted in a variation in total costs from $9,472,000 to $13,475,000.
ALTERNATIVE 5: Monitoring, Waste Pile Removal, Groundwater Recovery, Water
Treatment, Soil Flushing, and Sediment and Surface Water
Removal
If this alternative were implemented, it would be identical to the previous
alternative except that soil flushing would be used in the abandoned drum area
rather than capping. Since all the technologies have been discussed in
previous sections, only the cost evaluation is presented in this section.
Cost
Capital costs for this alternative would be $7,671,000. The present worth. 'of.
the total costs at 10 percent discount rate for 30 years would be $10,625,000..
The sensitivity analysis resulted in a variation in total costs from $8,720,000
to $12,555,000.
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Analysis of the Alternative that Exceeds Applicable or Relevant and
Appropriate Federal Public Health and Environmental Requirements
AL TERNAT IVE 6:
Monitoring, Waste pile Removal, Groundwater Recovery, Water
Treatment, Sediment and Surface Water Removal, Excavation,
and Onsite Incineration
If this alternative were implemented, the abandoned drum area, the
t~lporary sludge storage area, and the two closed percolation ponds would
be excavated and backfilled. This material, as well as the two waste
piles and all sediment removed, would be incinerated onsite. Due to the
excavation procedures, regrading and revegetation would be necessary.
This alternative would also include groundwater recovery and treatment,
sediment and surface water removal, waste pile ~emoval, and the monitoring
proqram previously discussed.
This section only presents the evaluation of excavation, backfilling, and
onsite incineration since these technologies have not been Dreviously
discussed.
Effectiveness
Excavation involves standarn construction practices and would be effective
in removing conta~inated soil from the three designated areas. The risk
of leaving isolated pockets of conta~inated soil would be eli~inated by
~xcavating to the water table. Backfilling is also a well established
practice and the ability to locate an offsite source of fill should not
present a proble~. .
The use of an incinerator for the processing of hazardous materials has
been well documented, and should be effective in destroying the principal
organic hazardous contaminants (POHC) present in the soils and sediments.
Disposal of fly ash and any material not selected for incineration in an
offsite apDroved landfill would prevent any further onsite contamination
associated with these sources.
The time required for waste pile removal, excavation, and sediment r~oval
would be approximately seven months. Using a single, mobile, rotary kiln
incinerator operating 24 hours per day, the time required to incinerate
the estimated 47,825 tons of material would be approximately 1.25 years
which includes a 15 percent downtime.
Implementation of this alternative would, in a relatively short time,
eliminate the public health risks associated with the site. This would
be achieved through source removal, treatment, and destruction. The
possibility would exist for isolated areas of contamination to re~ain.
However, these areas should be small with sufficiently lowered contaminant
,,;r)ncentrations.
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I mplementabilit y
Excavation, backfilling, and the removal of material to an offsite landfill are
proven techniques and have been used effectively in similar situations.
The use of incinerators for the thermal destruction of hazardous waste is well
documented; however, an evaluation of trial burn results would be necessary for
the selection of optimum operational parameters and treatment. requirements.
Incineration would involve extensive operation and maintenance requirements for
efficient operation.
The excavation and backfilling procedures would involve the use of heavy
equipment, and therefore would present some safety concerns. This concern
would be amplified due to the amount of time (seven months) required to
complete the excavation and sediment removal process. Safety considerations
for onsite incineration would center around worker exposure to site
contaminants during incinerator loading and handling of thermally refractive
material.
There are no factors which should prevent the implementation of the excavation
and incineration portions of this alternative. However, careful coordination
among the various components would be required for efficiency to be maintained.
The implementation of this alternative would have the potential to negatively
impact the public health. The technologies of concern include sediment and
surface water removal, excavation, and on-site incineration. Sediment and
surface water removal have been previously discussed. During the excavation
procedure, the potential for off-site migration of contaminants would be
increased. Pathways for this migrat'ion would include- airborne particulates,
volatile organic vapors, and surface runoff. Receptors in the area of the site
would be susceptible to inhalation of vapors as well as contaminant-laden
particulates, the ingestion of particulates, and direct contact with the
excavated soils.
Incineration could also produce some public health risk. These risks would
primarily arise from emitting products of incomplete combustion (PICs). PICs
could result not only from the waste material, but from the auxiliary fuel as
well. The particular PICs emitted would be dependent on the waste and
incinerator operation parameters. Receptors in the path 'of the incinerator
plume could inhale these emissions.
Other factors having an impact on public health would be the storage of the
. material prior to incineration and. the offsite transportation of fly ash and
the material not selected for incineration. Storing the waste onsite would
increase the chance of contaminant loss due to volatilization and surface
runoff. Transporting the waste offsite would have the potential to increase
receptor exposure to fugitive gas emissions, dust, and direct contact in the
event of an accidental spill.
Incineration should not be expected to add significantly to the environmental
impact. However, environmental receptors in direct line with the incinerator
plume could be subject to emissions. The use of air pollution devices would
keep air emissions within compliance standards and relieve
32
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envir~nmental stress. Any n~ative envir~nmental imoact that mi~ht result
from incineration would be further reduced due to the short amount of
time (1.25 years) estimated to complete the incineraiton process.
This alternative through source reduction treatment and dest~Jction would
alleviate the majority of the contamination at the site. Therefore,
i~lementation of this alternative would be expected to mitiJate any further
environmental impact.
The incineration of hazardous waste is regulated under RCRA: therefore,
the onsite incinerators would have to operate within these requirements.
,~ditional state and local regulations could include solid waste storage
and air quality emissions requirements. The ash generated by incineration
would have to be disposed of in an approved landfill. The transporter
requirements discussed would also be applicable to this alternative.
Cost
Capital costs for the onsite mobile incineration facility would be
$27,911,000. The capital cost for incineration would include the offsite
disposal of fly ash in a local approved landfill as well as disposal of
materials not selected for incineration. The costs for excavation were
based on a unit crew which would include one front-end loader. The
capital costs for excavation would be $820,000.
The operation and maintenance costs for excavation would include periodic
inspections and cover crop maintenance. The present worth at a 10 percent
discount rate and 30 years for the total costs would be $38,031,000.
The volume of material that would be excavated and the amount of material
that could be incinerated have the ~reatest impact on costs. A 20 percent
variation in the volume of material and a 30 percent variation in the
volume rerlucted by incineration was used. This caused the present worth
costs to vary from $27,721,000 to $48,365,000.
Analysis of the Alternatives that Specify Offsite Disposal
AL TER~TIVE 7:
Monitoring, Waste Pile Removal, Groundwater Recovery, Water
Treatment, Sediment and Surface Water Removal, Excavation,
and Offsite Disposal
If this alternative were implemented, it would be identical to the previous
alternatives, except that the excavated material, sediment, and waste
piles would be disposed of in an offsite EPA-approved RCRA landfill
instead of being incinerated onsite.
33
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Since all the technologies that compose this alternative have been
previously discussed, this section only presents the evaluation of the
disposal of contaminated soils and sediment in an offsite EPA-approved
RCRA f aci li ty .
Effectiveness
Disposal in an offsite landfill would be a permanent remedial action for
the Zellwood Groundwater Contamination Site and would provide a high
level of environmental and public health protection. This alternative,
through source rerroval, would prevent any further migration of contamination.
]mplementability
The implementation of this alternative would present some logistical
problems. These would primarily concern the coordination of excavation
rate and transportation. The estimated time that would be required for
excavation and sediment removal is seven months. Transportation of the
excavated material offsite would be done in trucks with a 20 cubic yard
capacity and would require approximately 2,400 shipments.
The ability to secure transporation for the removed material should not
present a problem. The performance of EPA-approved RCRA landfills. has
been demonstrated for the disposal of hazardous waste.
The. majority of the health effects that would be associated with tmplementing
this alternative have been previously discussed. Additional concerns
would involve movin,~ the material outside the confines of the site.
Public acceptance considerations, in addition to those previously discussed,
would involve the transport of the exhumed material. Increased traffic
generated by the transport of material might create some disruption, but
attention to routing and scheduling should increase public tolerance.
Cost
The total capital costs for this alternative would be $25,419,000.
Capital costs for off-site disposal would include tranportation and
disposal fees. The disposal fee is based on the costs at the EPA-
approved RCRA 'landfill in Emelle, Alabama. These costs are approximately
$30 less per ton than the disposal fee at the Pine WOod, South Carolina
tacility.
Operation ahd maintenance costs for the revegetation of the backfilled
material were based on four times per year. The annual operation and
maintenance costs for this alternative would be $458,648. The preseAt
worth at a 10 percent discount rate and 30 years for the total costs
would be $28,349,000.
34
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A sensitivity analysis was performed on various components of this
alternative. The most significant of these concerned the volume of waste
to be excavated and tranported to an off-site landfill and a 20 percent
difference in the volume was used. The sensitivity analysis resulted in
a present worth cost variation of $22,853,000 to $33,870,000.
ALTERNATIVE 8 - Monitoring, Waste pile Removal, Groundwater Recovery,
Water Treatment, Sediment and Surface Water Removal, Excavation,
and Off-Site Incineration
If this alternative were implemented, the soils, sediments and waste
piles would be excavated and incinerated off-site. Due to the excavation
procedure, regradinq and revegetation would be required. This alternative
would also employ the groundwater recovery and the water treatment process
and the monitoring program.
This section will present the evaluation for off-site incineration since
the remaining technologies have been previously evaluated.
Effectiveness
Incineration would be effective in destroying many of the contaminants at
the site. Source removal with off-site incineration would prevent further
conta~ination associated with the soil and sediment, thereby providinq
substantial environmental and public health protection.
The performance of incineration for the destruction of hazardous waste
has been well doc~mented. The operation and maintenance, similar to the
use of an off-site landfill, would be ~inimal.
The implementation of this alternative should effectively negate any
residual risk associated with the site contaminants. The possibility
would exist for isolated areas of contamination to remain. However,
these areas should be small with sufficiently lowered contaminant
concentrations.
Implementability
The logistical problems would also be applicable to this alternative.
The nearest appropriate commercial incinerator to the site is located in
Calvert City, Kentucky approximately 850 miles away. This facility has
the capacity to incinerate 297 tons per day; and therefore, could
theoretically dispose of the excavated soils and sediments in a few
months.
Since commercial incineration facilities require that the material ~
incinerated is contained in a drum or fiberpack; this would eliminate the
release of particulates and fugitive qases during transportation.
35
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The transporter requirements would also be applicable to this alternative.
In addition, the commercial incineration facility must be in compliance"
with all applicable standards of Federal environmental and public health
statutes.
Public acceptance of this alternative would be the same as that discussed
in off-site landfilling.
Cost
The captial costs for this alternative would be $45,158,000. Capital
costs for off-site incineration would include tranportation and incineration
fees. The incineration fee was based on the costs at the EPA-approved
RCRA incinerator in Calvert City, Kentucky. These costs are approximately
$900 less per ton than the incineration fee at the Rock Hill, South
Carolina facility.
Operation and ~intenance costs for the revegetation 'of the backfilled
material were based on four times per year which would make the annual
operation and maintenance costs $457,880. The present worth for 30 years
3t a 10 percent discount rate for the total costs would be $4£,088,000.
.
A sensitivity analysis was performed on various components of this
alternative. The most significant of these concerned the volume of waste
to be excavated and transported to an off-site incinerator and a 30
percent difference in the waste volume was used. The sensitivity analysis
resulted in a present worth cost variation of $34,761,000 to" $61,439,000.
Analysis of Additional Alternatives
ALTERNATIVE SA - Monitoring, Waste Pile Removal, Groundwater Recovery",
Water Treatment, Sediment and Surface' Water Removal,
Off-site Disposal
After reviewing the draft Feasibillty Study, it was requested of the program
that an additional alternative be considered. This additional alternative
would be a combination of the original Alternative 5: combined with portions
of Alternative 7. This alternative was described in detail in the Fact Sheet
that was developed as part of the required public ccmnent period. This
alternative was identified as Alternative SA.
Alternative SA consists of:
o
Excavation of soils/sediments from the three existing ditches,
the two ponds in the abandoned drum area, the two waste piles
in the abandoned drum area, the temporary sludge storage
area, and the two forrnerDrum Service perculation ponds:
o
Removal of the excavated soils/sediments to an offsite
36
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RCRA approved facility;
o
Removal and treatment of the groundwater in the shallow aquifer;
o
Flushing the treated groundwater back through the abandoned
drum area;
o
long-term monitoring for the private well in the area.
Alternative 5A would be classified as one of the alternatives that exceeds
applicable and relevent requirements. The various evaluations would be
similar to the evaluations for Alternative 5. The capital costs for
this alternative are approximately $11,647,000.
37
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SECTION VI
REMEDY SELECTION
The selected remedy will consist of a combination of the various alternatives
that have been presented.
Several areas have been selected for excavation. The basis of the selection of
these areas was two fold: the levels of contamination that were found in the
surface and subsurface soils and the historical data regarding waste
water/sludge storage/runofff areas. These areas are: 1) two former perculation
ponds used by Drum Service Company; 2) temporary sludge storage area; 3) three
onsite ditches; 4) sludge from two existing ponds in abandoned drum area; and
5) waste piles in abandoned drum area. This will be approximately 5800 yd. of
soil/sed iment.
Several options were considered for the treatment and/or disposal of the
excavated soil. The majority of the contamination in the excavated soils is of
an organic nature. Because of this, solidification was not considered to be
appropriate. Because of the upcoming .land ban, off site disposal was ruled.
out. The appropriate treatment technology was deemed to be thermal
destruction. An appropriate test will be conducted on the ash to determine
final disposal.
The contaminated soil in the abandoned drum area poses a different problem.
The soil is contaminated with both organics and inorganics. Thus, to eit.her
incinerate or solidify would be inappropriate. Two other options were
considered. The first option consisted of capping ttle approximately six acre
area. The second option consisted of flushing the area with clean water.
Because the second option provides for a more permanent clean up of the
abandoned drum area, it was selected. The abandoned drum area will be flushed
with clean water until clean up has occurred.
There are two aquifers at the site. The Floridan aquifer, the lower aquifer,
is separated from the water table aquifer by the Hawthorne formation. The
sample results obtained during the RI did' not. ind icate any contamination that
could be related to the site. On that basis, no remediation of the Floridan
aquifer is recommended. However, because the Floridan is the only source of
drinking water at the site, a long term monitor program for. it will be
implemented. .
The surficial aquifer is demonstratively contaminated throughout its entire
vertical extent. The direction of flow is to the southwest; towards the muck
farms. Because the surficial aquifer has been determined to be a Class I
aquifer and because of concern that the surficial aquifer might
38
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contaminate the Floridan aquifer, an active groundwater remediation program
will be implemented. This will consist of an extraction and a treatment
system for this wat~r. The treated water will then be pumped back throu~h
the abandoned drum area to facilitate the cleanup of that area. It is
estimated that the groundwater cleanup will take approximately fourteen years.
It is estimated that the present worth cost of this remedy is $13,543,244.
39
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SECrION VII
ro1MUNITY RELATIONS
As required by the NCP, a Community Relations Plan (CRP) was developed
and submitted to the Agency for this project. Two separate repositories
have been set up. One repository is located at the Zellwood Community
Center. The other repository is located at the Zellwood Elementary
School.
A public meeting was held on September 30, 1986 to present the findings of
the RI/FS. This meeting also initiated the start of the three-week
public comment period.
Less than ten written ccmnents were received by EP.a.. Those ccmment,
along with the transcript of the public meeting, are included in the
Responsiveness Summary.
Appropriate Community Relations, as required by SARA, will continue
throughout the RD/RA phase of the project.
40
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SECTION VIII
CCMPLIANCE WITH OTHER ENVIRa-Jr1ENTAL LAW:;
The applic~ble laws at the Zellwood Groundwater Contamination site are as
follows:
o
EPAls Groundwater Protection Strategy;
Clean Water Act;
Resource Conservation and Recovery Act, 1984 Amendements;
National Environmental Policy Act;
Various dredge and fill programs
Executive Order 11990;
Florida Class III Surface Water Standards (FAC Chapter 17-3);
Safe Drinking Water Act;
Florida State Drinking Standards (FAC Chapter 17-22);
o
o
o
o
o
o
o
o
By perforni~ an RI/FS at the Zellwood site, EPA has fulfilled the
requirements of NEPA.
Destruction of the contaminated soils by inceneration will have to meet
the requirements of Parts 264(0) and 261 Appendix 2 of RCRA, along with
Chapter 17-30 of the Florida Administrative Code. RCRA part 264 (0)
governs all aspects of incineratore test burns, and RCRA Part 261 Appendix 2
gov9~S the EP Toxicity requirements governing incineration (FAC 17-30)
adopts RCRA Part 264(0) without further state-imposed regulations.
Therefore, incineration activities must be conducted in accordance with
applicable portions of RCRA.
SARA now has codified the requirement that EPA apply its Groundwater
Protection Strategy to any site where contaminated groundwater may be of
concern. In accordance with that, EPA Region IV Groundwater technology
experts assessed the two aquifers (memo, Mitchell to Wright, 4/7/87).
Groundwater in the surficial aquifer was classified as a Class I based,
on the presence of threatened or endangered species in groundwater
discharge areas. \vithiri the two mile classification review area.
The Florida aquiferr was classified as a definitive Class IIA, and could
potentially be Class I. Based on these classifications, plus the
site-specific data, it was determined that groundwater remediation be
undertaken.
The recovered groundwater will be treated and discharged into the abandoned
drum area. The discharge will meet all applicable surface water and
~roundwater standards.
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~te~ this remedy has been completed, the~e should be no fu~the~ threat
~esulti~ f~om the a~eas add~essed by the Supe~fund p~CX]ram. Thus, no
RCRA loN;-term moni toring prog~am will oe ~equi~ed.
.
42
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,
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SECTION IX
ENFORCEMENT ANALYSIS
Four Businesses currently operate at the Zellwood Groundwater Contamination
site. The Drum Service Company of Florida recycles used, steel drums. The
drums are recycled by incineration at a minimum of 1600°F, cooling,
straightening, and painting. 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 picked up by 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
N'APA Inc. NAP A also owns the property inhabited by the abandoned drum area.
\'A?A Inc. funded the emergency removal that was supervised by EPA in 1933.
NAPA hired Drum Service to be their contractor for the emergency removal
project.
Drum Service participated in the negotiations to implement the RI/FS Work
Plan. The company ultimately declined to implement EPA's RI/FS Work Plfen.
Drum Service did submit an .RI/FS Work Plan of their own; however, EPA did not
accept that Work Plan as being the technical equivalent to EPA's 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. The Drum Service
Company has been cooperative about allowing site access for the investigative
work. Drum Service has remained very interested in following what EPA is doing
at the site.
Douglass Fertilizer, which operated on the Zellwood site from the mid 1970's to
1984, has relocated to another piece of property across Zellwood. The company
currently operating on the old Douglass Fertilizer Company property, Coatings
Applications and Waterproofing Company, reportedly 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 at the initiation of the RI/FS PRP negotiations.
The company showed no interest in implementing the project.
The Florida Department of Environmental Regulation (FDER) filed suit against
the Drum Service Company in March 1986. The suit was to force Drum Service to
bring its incinerator into compliance with applicable air regulations. As of
the date of this ROD, the outcome of the suit was unknown.
43
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The Drum Service Company and its consultant, Geraghty & Miller, Inc., has been
in contact with FDER several times in regard to the EPA RI/FS. EPA, by choice,
was not directly involved with these discussions.
,
44
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L(~)
AMENDED RECORD OF DECISION
FUNDAMENTAL CHANGE
SITE NAME AND LOCATION
,
Zellwood Groundwater Contamination Site
Operable Unit .1 (OU '1)
Zellwood, Orange County, Florida
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 (PAMS). The Florida 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
Excavation of the soils and/or sediment.
depicted in rigure. 2 and 3,
the exi.ting abandoned drum areas;
former percolation pond '2;
abandoned drum pond;
Dougla. Fertilizer Pond '1;
Middle Ditch South; and the
South Ditch West.
at the following locations
Verification sampling of excavated areas.
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-2-
Activity 2
Stabilization/Solidification of the excavated soils and sedLments;
construction of a solid~fied monolith.
Leachability testing of solidified soils during construction of the
solidified monolith.
Placement of the stabilized/solidified 80ils 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 ~n this ROD for Operable Unit fl.
EXPLANATION OF FUNDAMENTAL CHANGE
Furthe~ 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 i.
signiticantly 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 treat88nt 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 tollows: Pirst,
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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solidi!ication i. a different type of treatment criteria. Third, the cost of
the selected remedy is substantially 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
without removal of hazardous constituents off site. Further, the fundamental
change meets Applicable and Relevant and Appropriate Requirements at a lower
cost. '
DECLA.~'!'ION
The selected remedy is protective of human health and the environment,
attai~s federal and state requirements that are applicable or relevant and
appropriate, and is cost-effective. This remedy satisfies the preference for
treat=ent that reduces toxicity, mobility, or volume as a principal element.
Final:y, it is determined that this remedy utilizes a permanent solution and
alter~ative treatment te=hno~cgy to the maximum extent practic~le. 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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Greer C. Tidwell
Regional AdIT.inistrator
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SUMMARY
of the
REMEDIAL ALTERNATIVE SELECTION
ZELLWOOD GROUNDWATER CONTAMINATION SITE
ORANGE COUNTY, FLORIDA
Prepared by:
U.5. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
ATLANTA, GIORGIA
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9.0
TABLE OF CONTENTS
1.0
INTRODUCTION .................
1.1 Executive Summary. . . . . . . . . . . .
1. 2 Subsequent Action. . . . . . . . . . . .
1.3 Fundamental Change in Previous Remedy
1.4 Site Location and Description. . . . . . .
1.5 Site and Regulatory History. . . . . . .
1.6 Previous Site Activities. . . . . . . . .
1.7 Regulatory Actions. . . . . . . . .
2.0
ENFORCEMENT ANALYSIS
. . . .
.........
3.0
CURRENT SITE STATUS. . . . . . . . . . . . . .
3.1 Site Geology and Hydrogeology
3.2 Previous Site Investigations. . . .
3.3 Remedial Investigation Results. . . . . .
3.3.1 Soil Investigations. . . . . . . . . . .
3.3.2 Subsurface Investigations. .
3.3.3 Discussion of Sampling Activities.
3.3.4 Air Investigations. . . . . . . . . . .
3.4 Routes of Transport and Potential Receptors
3.5 Contaminants of Concern. . . . . . .
. . . .
4.0
CLEANUP CRITERIA. . . . . . . . . . . . . . .
4.1 Soil/Sediment Remediation. . . . . . . . .
5.0
ALTERNATIVE EVALUATION. . . . . . . . . .
5.1 Alternative 1 - No Action. . . . . .
5.2 Alternative 2 - Solidification/Fixation. .
5.3 Alternative 3 - Off-Site Disposal. . . . .
5.4 Alternative ~ - On-Site Incineration
of Contaminated Soils. . . . . . . . .
5.5 Comparative Analysis. . . . . . . .
6.0
RECOMMENDED ALTERNATIVE. . . . . .
6.1 Description of Remedy. . . . . . . .
6.2 Operation and Maintenance. . . . . .
6.3 C08t E.timat.. . . . . .
6.4 Coat Eff.ctiv.n... . . . . . . . . .
6 . 5 Sch8clule . . . . 0 0 0 0 0 0 0 '. . 0
7.0
COMPLIAHC8 WID OTHER ENVIRONMENTAL LAWS.
8.0
COMMUNITY aBLATIONS HISTORY
. . . .
STATE INVOLVEMENT
........
. . . .
Appendix A - Analytical Re8u1t., 1988 Study 00
RESPONSIVENESS SUMMARY
.......
. . . .
. . . .
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1
1
2
2
2
5
S
9
9
10
10
11
12
15
lS
15
25
2S
26
30
30
31
31
33
33
33
34
34
35
36
36
36
37
37
38
39
40
52
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LIST OF FIGURES
Figure 1 - General Site Location Map
. . . . .
Figure 2 - Site Sketch
. . . . . . . .
. . . . . . .
Figure 3 - Soil and Sediment Sampling Locations. . .
Figure 4 - Sample Grid Pattern
. . . . . . . .
Figure Sa - Vertical Distribution of Contaminants. .
Figure Sb - Vertical Distribution of Contaminants. .
Figure 6 - Geologic Cross-Section
. . . .
. . . . .
Figure 7 - Geologic Cross-Section
. . . . . .
-ii-
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
Table 2 - Purgeable Organics
. . . .
. . . .
. . . . . .
27
Table 3 - Sample Number Soil and Sediment Samples
. . . .
28
Table 4 - Clean-Up Criteria. . .
. . . .
........
30
Table 5 - Technologies Considered for Screening.
. . . .
32
Table 6 - Preliminary Cost Estimates
.....
. . . . .
35
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Amendment to the Record of Decision
Summary of Remedial 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 Investigation/Feas~bility
Study (RIfFS) at the site. This RIfFS was conducted to identify 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 delineated a variety of problems. These are:
.
Contaminated sediments located in drainage ditches, the percolation
pond, the Douglas Fertilizer 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
Feasibility Study, EPA issued a Re:ord of Decision (ROD) in December,
1987. This ROD is included as Appendix A. The ROD recommended the
following actions:
.
Excavation and incineration of sOils/sediments in the on-site
ditchea, temporary sludge and two former percolation ponds, and
wa.te pile..
.
Appropriate leachability teating and diapo8al of the incinerated
80i1.
.
Grou~t.r removal and treatment for the 8urficial aquiter.
-1-
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1.2
SUBSEOUENT ACTION
After review of the ROD, the Florida Department of Environmental
Regulation (FDER) concluded that the remedy selected by EPA was not
substantiated by the FS. As a result, EPA and FDER agreed to re-assess
the 9roundwater 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 al.cernatives 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 selectee 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, solidification is a different type of treatment
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 Oranqe County, Florida, approximately one-half
mile we.t of the unincorporated town of Zellwood. The 57-acre Site, as
shown in PLvure One, con.i.t. of an area occupied by four industries and
an open field with a mar.hy wetland. area.
The Site im .ituated in a rural area. Small re.idential communities are
located to the north and to the ea.t with aqricultural lands to the
.outh and we.t. There are approximately 300 home. within a one-mile
radius of the Site. The.e home. depend on private well. for potable
water .upply. In addition, Zellwood Water U.er., Inc. has two public
water .upply well. within a half mile ea.t of the Site .ervicing about
700 to 800 people. In addition to these industries and the residences,
there are .everal plant nur.erie., vegetable growing operation., and
citrus groves.
-2-
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FIGURE 1
General Site Location Map
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.
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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 System., 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 busillesses are located in the industrial area
surrounding the Site. Adjacent to the Zellwin Farms facility there is a
m~grant worker hotel.
Approximately one-half mile 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 t-2 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. Re.idential use totals 10
percent, followed by commercial, industrial, and transportation area.
occupying 9 percent. Seven percent of the land area is combined lake
and wetland area..
1.6
PREVIOUS SI~ ACTIVITIES
Drum Service Campany of Florida, a drum recycling facility, began
operations in 1963. In the course of recycling used drum., wa.tewaters
were generated through the draining and cleaning procedure.. From 1963
until 1975, the Company u.ed two on-site evaporation/percolation ponds
for treatment and di.posal 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 .1 and '2, are
depicted in Figures 2 and J.
-5-
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FIGURE 2
Site Sketch
-6-
-------
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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 .ludge 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 8urface 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 representatives 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 Zellwood Groundwater Contamination Site. The abandoned drum area
was apparently used for the disposal of drums and other wastes. Based on
unsubstantiated reports from resident. in the area, some of the material
may have beeft there for mare than 20 years.
The Zellwood Site was listed on the first final National Priorities List
which wa. pub11.hed 1n the Federal Register in 1983. In the fall of 1983,
EPA'8 Reg10n IV lmergency ".ponse and control Section (ERCS) over8aw a
Potential ".ponsible Party (PRP) removal action at the abandoned drum
area of the Site. In 1984, a Remedial Action Kaster Plan was developed
and a Work Plan for the RI/rs was formulated. Negotiations with the PRPs
were initiated, but the PRP. did not implement the EPA Work Plan. EPA,
using its rIT, implemented the RI/rs in 1985. The Site was resampled in
June 1988 to confirm levels of contamination in both water and soil.
-8-
-------
<-
:".7
REG~~~TORY 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. 1048-2077 for
this system on July 31, 1975. In 1980, further design changes were made
eliminating use of the ponds for storage of wastewater. As of 1985, Drum
Service Company of Florida held FDER Permit No. A048-27470B 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
not, in the past or currently, held any industrial waste treatment
permits. Chemical Systems, Inc., reportedly did not generate either
waste or wastewater, and thus would not have a permit.
have
solid
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 eteel 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 tre.tment system was
discharge4 1nto two evaporation/percolation pon4s. pre.ently all effluent
is reportedly recirculated through a closed loop system .nd used as
conveyor cb&1n cooling water in the incinerator sy.tem.
Drum Service Company of Flori4a currently le.... the business property
from NAPA Inc. NAPA also owns the property which hou.ed the abandoned
drum area. NAPA Inc. funded the emergency removal that w.. .upervi.ed 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 implement the BPA RI/FS Work
plan. Drum Service did submit an RI/FS Work Plan of their own; however,
-9-
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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 RIIFS 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 (Kay 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 Umplementing 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 mechani8ms. 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 i8 somewhat 8teeper than is regionally normal.
This may be due to continuou8 pumping of 8urface water out of the muck
farm area directly south of the Site. The general direction of flow is to
the .outh-southwe.t.
aetween the .urficial and Ploridan aquifer. i. the Hawthorne pormation.
In the area, the Hawthorne consists of a green to yellowish-green clay.
which i. underlain by a brown to white dolomite or dolomitic lime.tone.1 A
clay-like .and layer in the upper Hawthorne retard. the vertical movement
of water between the .urficial aquifer and the limestone of the Floridan.
The dolomite. and lime.tone. of the lower Hawthorne may be con.idered to
be hydraulically part of the Ploridan aquifer. The Floridan i. the major
.ource of potable water for people living near the Zellwood Site.
Regional potentiometric .urface map. indicate a northea.terly direction of
groundwater flow in the Floridan aquifer. The water level measurements
taken in the Floridan aquifer well. at the Site in Kay, June, and
-10-
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September 1985, were plotted and contoured. Examination of this data
confirms a divergency from the normal ; '~theasterly flow and suggests that
water levels at the Site are not repre ,tative for the determination of a
regional flow direction in the Florida: aquifer. The anomalies of the
potentiometric surface of the Floridan aquifer could be an effect of
numerous factors including a structural depression at the top of the
Floridan Formation, local p~page 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 ~ediately below the Hawthorne Formation while the other two were
set in the limestone of the Floridan Aquifer.
3.2
PREVIOUS SITE INVESTIGATIONS
Numerous investigative activities have taken place at the Zellwood
Groundwater Contamination 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 sample. collected
from temporary monitor well. 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 ot ar.enic and other contaminants. A
surface water sample was a180 collected from th.-large pond on
Southern Liquid Fertilizer.
In November 1981, Drum Service Company of Florida retained Seabury
and Bottorf Associate., Inc. to conduct a soil and water sampling
investigation along the right-ot-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 ~ Environment, Inc.,
(E&K) 1ft April and July 1982, indicated the presence of possible
grOUDdweter contamination plumes on the south side of both Drum
SerYice Company and Douglas Fertili&er Company.
During July and August 1982, FIT (E~E) conducted a sampling
investigation and installed six groundwater monitor wells in three
locations. Surface water and sediment, s011, and groundwater samples
were collected for analysis. However, much of the data was unusable
because of OUality Aasurance reasons.
-11-
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The EPA Environmental Services Division (ESD) conducted a hazardous
waste .ite field investigation during December 1982. 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 ditch.. .ince 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 .ubsurface boring program,
installation of 17 monitor wells, groundwater sampling and analysis, and
data evaluation.
Surface water and 8ediment .amples were al.o collected from ditches within
the study area. The re.ult. were compared with previous 8tudy re8ults to
a88e8S change8 in water quality and .ediment contaminant leve18. The
contaminant8 found in the .urfac. water and .ediment .ampl.. were
evaluated to identify .ource area.. The analytical re.ult. of the
8ampling inv..tigation. for 1982, 1985, and 1988 have been compiled in
tabular fom. in Appendix A. A dra.tic change in contaminant
concentrat1ona can be ...n by reviewing the data. The change. could be
attr~uted to the pump well. n.arby a. well a. many other factor.. The
pump rat.. are approximately 125 million gallon. per month in the dry
.ea.on and 1.3 billion gallon. per month in the w.t ..a.on. This could
eventually draw .lug. of contamination accro.. the area at varying rates
and be observed in a random .ampling.
The waste areas at the Sit. were identified u.ing hhtoric aerial
photographs and geophy.ical techniques. Surface and .ubsurface soil
.ample. were collected from these areas to evaluate the potential tor
contaminants to migrate to groundwater. The r.sult. of the analy... were
a180 used to estimate the vertical extent of contamination.
.-12-
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FIGURE 3
Soil and Sediment Sampling Locations
-13-
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3.3.1
SOILS INVESTIGATION
In June 1988, as part of aoditional RI/FS work, post 1987 ROD, EPA
conducted a thorough resampling of the Site to determine contam~nant
levels and migration patterns.
Soil samples were collected in several designated areas of the Site
including the fQllowing areas: 1) abandoned drum area; 2) former Drum
Service percolation ponds; 3) temporary sludge storage area; 4) railroad
right-of-way; and 5) current Drum Service area. The soil sampling
locations are depicted in Figure 3.
3.3.2 SUBSURFACE INVESTIGATION
Test Borino Proqram
As part of the June 1988 investigation, a test boring program was
insiituted at the Zellwood Groundwater Contamination Site to further
characterize the Site geologically and to determine intervals for well
screens prior to well installation. 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,
whichever was less. The confining Hawthorne Formation was not penetrated
at location number two because of the suspected high levels of
contamination in this 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 Site.
Figures 5(a) and 5(b) show the locations of cross sections. These figures
also show fence diagrams for the Site developed using wells logs from all
test boring locat~ons.
3.3.3
DISCUSSION 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 Region IV - Engineering Support Branch Standard Operating
Procedures and Quality Assurance Manual, reterred to as the SOP.
Twenty-six percent of the total specific site aamples were split with the
PRP, as requ..ted by the PRP. Surveying of soil and groundwater aampling
location. va. conducted by the EPA Emergency Re.pon.e Team (ERT), Edison,
New Jer..,.
The Ze11wood Site wa. divided into five .oil and .ediment .ampling
area. to confirm .oil contamination levels.
1.
Abandoned Drum Area
A sample grid pattern 100' x 100' wa. used in this are. depicted
in Figure 4. Each grid point was surveyed. The grid pattern
-15-
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FIGURE 4
Sample Grid Pattern
-16-
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SAMPLE GRID PATTE~~
-li-
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FIGURE SA AND 58
Ver~ical Distribution of Contaminants
o
-18-
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A
100
90
80
70
60
50
40
30
20
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-20-
-30
VERTICAL
7
-------
VERTICAL DISTRIBUTION OF CONTAMINANTS
Figure 5b. Vertical Distribution of C.oni .imin.nl ion
-------
A'
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WATFR TABLE
HAWTHORNE TORMATION
CON I ACT
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FIGURE 6.
GEOLOGIC CROSS-SLCTION
/ELI-WOOD NPL SI1L
NOTF: VfRIK.AL EXAGOf RATION =- lOflX
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Gl OIOGIC CROSS-SECTION
/i LLWOOD
sin:
NOTF: VIRTICAI TXAOCrRATION = 10.8X
SEPA
-------
was four columns wide and five rows high. Row A of the actual
grid pattern was placed in the approximate position of Row B in
the sampling plan. Row F could not be placed in the drum area,
therefore, it was eliminated. The pond in the drum area fell
outside of the grid pattern, and the entire pattern was tilted,
northeast to southwest approximately 20..
2.
Sludqe Storaqe Area
One composite sample was collected per cell from five distinct
sample points. Sample depth was six to 12 inches for two
reasons. First, the sludge storage area is now located in a
fairly high traffic area. Therefore, surface soils would not be
representative. In addition, over the last five years the
surface soils have been scraped occasionally by the site
operator.
3.
Existinq Ponds
There are currently four ponds on-site. Sediment samples com-
posited from five distinct point. were collected from each pond
or pond section.
a.
Douqlas Fertilizer Ponds
Dur~ng the years that Douglas Fertilizer was in operation,
wastewater from fertilizer formulations was discharged into
three unlined ponds. One composite sample was collected
from the dry pond at a depth of zero to six inches.
samples were sent to Contract Laboratory Program (CLP) for
a full Target Compound List (TCL) scan, and split with ERT
for screening of metals and cyanide (CN). The larger
Douglas Fertilizer pond is below the water table and always
contains water. Due to its size, the pond was divided into
two sections. Each section had one composite sediment
sample. samples were sent to the CLP laboratory for a full
TCL scan and to ERT for screening of pesticides.
During an investigation of the Dougla. Fertilizer property,
a stained area was found. It was sampled, labeled DFP-O,
and 8creened for pesticides by ERT.
b.
Abandoned Drum Area Pond
The pond was sampled as one composite .edim8nt sample.
The sample was .ent to the CLP laboratory for a full TCL
scan, and split with IRT for .creening of metal. and CN.
4.
Former Percolation Pond.
The two percolation ponds u.ed by Drum Service. Company were
excavated and backfilled in 1982. Becau.e of thi., .ample. were
collected at a depth below three feet. Bach pond was divided
into two .ection. with one compo.ite .ample collected per
-23-
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8ection. 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,
8plit with ERT for a full TCL scan and three samples were split
with the PRP.
5. .
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 cl08est to the north-middle ditch
intersection and on each side of the railroad tracks ~ere
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 .amples. Samples
KDS-l, and MDS-3 through KDS-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 .ampling data, only one area had contami-
nation of any .ignificance in the .outh ditch. Therefore,
only two grab .ample8 were collected, one on each side of
the ditch between Dougla. Fertilizer and Drum Service..
Both .ample. were .ent to CLP for a full TCL .can and
.crMud by IRT for a full TeL.
4.
ZeUwin Ditche.
Grab .ample. were to be collected in the approximate loca-
tion. a. tho.e collected in 1985. Two .ample. were
collect8c!, ea.t and we.t of the Zellwin Farm. di.charge
ditch. Sample ZFD-2 wa. .ent to CLP.for a full .can and
.crHned through IRT for pe.ticide.. .
-24-
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e.
Tank Farm Ditch
There was a small ditch that ran from the Drum Services
Company tank farm to the north ditch. Since the Site inves-
tigation conducted on May 17, 1988, the ditch was converted
to a culvert. Because 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.
Doualas Fertilizer Ditch
This ditch runs between the old Douglas Fertilizer Company
and Drum Services. Two grab samples were collected from
this ditch and DFD-1 was sent to the CLP laboratory. Both
samples were sent to ERT for a TCL scan.
3.3.4
AIR INVESTIGATION
NO air samples were collected for analysis during the RI. However, under
normal conditions, it is unlikely that particulate or volatile
contaminants will present much of a threat to the nearby residents 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 this exposure pathway through solidification of the contaminated
soil.. Possible dU8t control will be implemented at the Site during the
remedial activities if airborne particulate increases. 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 times of heavy truck traffic within the drum storage
areas. EPA toxicologists have evaluated this pathway and determ~ned ~~at,
during soil excavation activities, air monitoring will be required fa:
personnel protection.
3.4
ROUTES OF TRANSPORT AND POTENTIAL RECEPTORS
Surface Water and Sediment/Soil
Surface water features at the Site include several ponds and three distinc-
tive drain&98 pathways referred to as the northern, middle, and southern
ditches. lurface water run-off at the Site is either confined in the
pond. Or 18 channeled to one of the ditches. Although Site drainage is to
the we.t aDd ultimately to the .outh toward the muck farms and Lake
Apopka, the data from the RI .hewed little migration of surface water
contaminant. off-site. Unle.. there ha. been a heavy incidence of rain,
the northern and middle ditches are u.ually fairly dry and contain only
isolated areas of stagnant water. The southern ditch contains a fairly
constant flow of water, since it receive. a direct di.charge and run-off
from the Zellwir. Farms large paved parkin; lot.
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3.5
CONTAMINANTS OF CONCERN
One of the June, 1988 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 "indicator chemical" process found in the
Superfund Public Health Evaluation Manual (draft December 17, 1985, 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.
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'l'ABLB
1
Pesticides & Organics
at the
Zellwood Groundwater Contamination Site
METALS
Arsenic
EXTRACTABLE ORGANICS
Napthalene
Cadmium
Acenaphthylene
Chromium
Fluorene
Lead
Phenanthrene
Cyanide
Anthracene
PESTICIDES
Dieldr"-n
Pyrene
Benzyl Butly Phthlate
4'4' DDE
Dry.ene
4'4' DDD
Senzo Flouranthene
Gamma Chlordane
Senzo-A Pyrene
Alpha Chlordane
Ideno-Pyrene
Benzo-Perylene
'rABL8
2
PURGEABLE ORGANICS
Tetrachloroethene
Toluene
Ethyl Benzene
Total Xylene
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DBLB 3
SAMPLE NUMBER
SOIL AND SEDIMENT SAMPLES
June 1988
Abandoned Drum Area
ADS-A1-1 Grid A1, 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-81-2 Grid 81, 6" - 18"
ADS-B2-1 Grid B2, 0" - 6"
ADS-B2-2 Grid 82, 6" - 18"
ADS-B3-1 Grid 83, 0" - 6"
ADS-B3-2 Grid 83, 6" - 18"
ADS-B4-1 Grid B4, 0" - 6"
ADS-84-2 Grid 84, 6" - 18"
ADS-C1-1 Grid C1, 0" - 6"
ADS-Cl-2 Grid C1, 6" - 18"
ADS-C2-1 Grid C2, 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"
t)
ADS-D1-1 Grid D1, 0" - 6"
ADS-Dl-2 Grid D1, 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 Grid D4, 0" 6"
ADS-D4-2 Grid D4, 6" - 1B"
ADS-I1-1 Grid 11, 0" - 6"
ADS-11-2 Grid 11, 6" - 18"
ADS-12-1 Grid 12, 0" - 6"
ADS-J:2-2 Grid 12, 6" - 18"
ADS-J:3-1 Grid 13, 0" - 6"
ADS-13-2 Grid 13, 6" - 18"
ADS-B4-1 Grid 14, 0" - 6"
ADS-14-2 Grid 14, 6" - 18"
ADS-IS-1 Grid IS, 0" - 6"
ADS-15-2 Grid 15, 6" - 18"
TSA-l Temporary Sludge Storage - Grid 1
TSA-2 Temporary Sludge Storage - Grid 2
-28-
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~ 3 (Cont'd.)
SAMPLE NUMBER
SOIL AND SEDIMENT SAMPLES
June 1988
Ponds
ADP
Abandoned Drum Area
FPP-l-Cl
FPP-l-C:2
FPP-:2-Cl
FPP-:2-C:2
Former Percolation Pond U - Grid 1
Former Percolation Pond U - Grid :2
Former Percolation Pond .:2 - Grid 1
Former Percolation Pond ,:2 - Grid :2
Douglas Fertilizer Pond U 0" - 6"
Douglas Fertilizer Pond ':2 0" - 6"
Douglas Fertilizer pond '3 Grid 1
Douglas Fertilizer pond '3 Grid :2
DFP-l-l
DFP-:2-l
DFP-3-1
DFP-3-:2
Ditches
ND-l
ND-:2
ND-3
ND-4
ND-S
ND-6
ND-i
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)
MD-l
MD-:2
MD-3
MD-4
MD-S
MD-6
MDS-l
MDS-2
KDS-3
KDS-4
KDS-S
Middle Ditch
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 16
Ditch Sample '1
Ditch Sample 12
Ditch Sample .3
Ditch Sample t4
Ditch Sample '5
SDE-l
SDW-1
South Ditch Ea.t Sample
South Ditch We.t Sample
ZFD-1
ZFD-2
Zellwin Farm Ditch 11
Zellwin Farm Ditch '2
TFN
Tank Farm North Sample 6" - 18"
DFD-1
DFD-2
DFP-O
Dougla. Fertilizer Ditch Sample 11
Dougla. Fertilizer Ditch Sample .2
Douglas Fertilizer Debris Area
-29-
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4.0
CLEAN-UP CRlTERI~
Based on calculations using site specific soil and climatic data and data
from the Soil Conservation Service, the University of Florida, and the US
EP~ Envirorunent'al Reeearch Laboratories, mathematical modele, and beet
professional judgment, EPA determined the ~lean-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 m,g/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 .ite. 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 EPA determine. through the excavation efforts that the levels for
cleanup are not attainable or approachable the.e levels will be
reconsidered by both the State of Florida and EPA.
4.1
SOIL/SEDIMENT REMEDIATION
,The remedial action .elected will con.i.t of removing the contaminated
.oil. from ~he Site. Stabilization/Solidification of those .oil. will be
conducted in a .uitable area, large enough to contain the completed
monolith and allow for worker. to operate equipDent and perform the
nece..ary activities to mitigate the problem. at this Site. There will be
approximately 3,000 cubic Y&fd. of .oil to be r8Dl8dia~ed. Du.t control
mea.ure. will be anticipated in the event of increa.ed particulate into
the atmo.phere in the area of excavation and 80lidification. Treatability
.tudie. have been conducted to in8ure the mixture. of fixation agent. will
prevent the contaminant. from leaching into the groundwater. Confirmation
.ampling will be conducted after excavation of the .oi1. to en.ure all
contaminant. have been removed from the Site; te.ting during construction
will verify the .ucce.. of the remedy.
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S.O
ALTERNATIVES EVALUATION
The purpose of the Operable Unit One remedial action at the Zellwood
Groundwater Contamination Site is to mitigate and min~ize contamination
in 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 exposure to
contaminated soils or sediments and water through inhalation,
inge8tion and direct contact.
To prevent the spread of contaminants in the groundwater, surface
water and soils.
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 statute. or other
regulations (Table 5-1). The goal. were developed to prevent potent.ial
groundwater contamination from exceeding ARAR. and to reduce potential
cancer risk from inhalation.
An initial screening of possible technologies was performed to identify
those technologies which best meet the criteria of Section 300.68 of the
National Contingency Plan (NCP). Following the initial screening of
technologies, 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 re.ults of the screening process. Each of the
remaining alternatives for soil and .ediment remediation were evaluated
based on cost, technical feasibility, in.titutional requirements, and
degree of protection of publiC health and the env~ronment.
5.1
~T!RNAT:rW 11
NO ACTIO"
The ri.k ........n~ conducted a. part of the remed~al inve.tigation .howed
that no action i. not protective of human health from the Site conditions
pre.ently exi.ting. contaminant toxicity i. not reduced in the ab.ence of
treatment. No action doe. no~ provide permanent .ource control, and doe.
not .ati.fy a preference for treatment.
Thi. alternative i. required to be con.idered by the NCP and i.
to provide a ba.e-level action again.t which other alternatives
compared.
pre.ented
may be
-31-
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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 FL
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
.tream.
*If Eliminated, ....on for Doing So.
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5.2
ALTERNATIVE 2:
SOLIDIFICATION/FIXATION
A silicate/cement-based stabilization process has been selected for
evaluation of the sOlidification/fixation of soils at the Zellwood
Groundwater Contamination Site. These methods have the ability to
stabilize materials containing high concentrations of heavy metals, even
under acidic condition8. M08t processes use two inorganic chemical
reagents which react with polyvalent metal ion8 to form a chemically and
mechanically stable solid. The process is based on reaction8 between
soluble 8ilicate8 and 8ilicate setting agents under controlled conditions
to produce a 801id matrix. Reagent8 commonly used include sodium
silicate, fly ash, kiln dust, and Portland cement (as the setting agent).
The resulting matrix is clay-like and display. properties of high
stability, low permeability, high alkalinity, high bearing 8trength, and
high cation exchange capacity. The resulting solid can be easily and
economically handled, transported and stored. The volume added to the
waste by the treatment process would be between 5 and 10 percent. A
vegetative cover will be constructed over the solidified waste.
This alternative is considered innovative for metals; but experimental for
organic compounds. During excavation and mixing of approximately 3,000
cubic yards of soil, some volatilization of organics will occur;
leachability testing for verification and groundwater wells near the
sol~dified monolith will monitor for any leaching of organic compounds.
Estimated Capital Cost:
$780,000 includes monitor wells
$250,000 operation and maintenance
5.3
A:.TERNA':'IVE 3:
OFF-SITE DISPOSAL
This alternative requires the excavation of all contAminated soi1 and the
disposal of the waste in an off-site RCRA permitted fac~lity.
Approximately 3,000 cubic yard. 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 top.oil and veqetated. Plorida Landfill restrictions
prohibits this activity. 50il. would have to go out of .tate. EPA policy
prefer. on-.ite, permanent remedies as oppo.ed to off-.ite landfillinq.
E.timated capital Co.t:
$1.12M
5.4
ALTERNATIVE 4:
ON-SI'rE INCINERATION OF CONTAMINATED SOILS
It is e.timated that it will take approximately (one) 1 year to incinerate
approximately 3,000 cubic yard. of on-site highly contaminated .oi18 at
&bout 1.75 ton. per hour.
The lack of organic contamination in large quantity at the Site prevent.
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:
51.75M 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 erotection of human health and the environment: and comeliance
with aeelicable or relevant and aeeroeriate 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 cerformance: reduction of toxicity. mObility.
or volume throuah treatment: short-term effectiveness: imelementability:
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 metal. contamination. 80th alternatives would
give the .ame effectivene.. both long and .hort-term .ince both
alternative. require 80lidification of the .oil. from the site.
Solidification ia much more implement able and coat effective than the
incineration alternative by almoat half the coat.
State/8uUDOrt aaencv acceotance: and community acceotance
Solidification receivea more .upport and acceptance than
initiating an incineration project within a local agricultural area.
The burning of contaminant. into the atmo.phere ha. never been easily
accepted by the public or many atatea, wherea. .olidification with
monitoring of the area i. more acceptable.
6.0
RECOMMENDED ALTERNATIVE
The recommended alternative for remediation of .oil an~ .ediment
contamination at the Zellwood Groundwater Contamination Site includes
-34-
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solidification and stabilization and backfilling of treated material on
the Site. During the March, 1989 Treatability Study, different mixtures
were analyzed for leachability of organics, pesticides and metals. A mix
can be chosen fom that analysis that does not leach &bove drinking water
standards into the groundwater. Therefore, 801idification and
stabilization of the contaminated soil provides a vi&ble remedy for the
Zellwood Site.
6.1
DESCRIPTION OF RECOMMENDED REMEDY
Contaminated soil will be treated u8ing stabilization/solidification
methods. Following treatment, the stabilized and solidified sOil/sediment
will be placed back into the excavated area, covered with approximately
six inches of top soil and s.eded to provide vegetative cover. At
selected intervals, during excavation, soil 8amples will be collected and
analyzed to determine the limits of excavations. Excavation will continue
in des~gnated areas until clean-up goals are reached.
TABLE
6
PRELIMINARY COST ESTIMATES
ZELLWOOD GROUNDWATER CONTAMINATION SITE
ZELLWOOD, ORANGE COUNTY, FLORIDA
Estimated Estimated Estimated
Construction O&M Total
Cost C08t C08t
Technology
SolidHicatior. S 780,000 $250,000 $1,030,00::
!Fixation
Incineration $1,746,240 $250,000 $1,996,240
Off-Site Disposal at $1,117,370 -0- $1,117,370
RCRA Facility
-35-
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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 sediments in the lagoons and
ditches. Another activity planned for Operable Unit One, groundwater
evaluation, will determine 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 is 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 MAINTENANCE
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 FDER, may evaluate conditions and determine the aampling
regime needed. Samples will be analyzed for the Target Compound List
metals, cyanide, PAHs, volatiles and pesticides.
6.3
COST ESTIMATE
Solidification/stabilization is expected to have a total estimated capital
cost of approximately $1.03 million. Thi8 estimate a.sumes a cost of $120
per ton for solidification/stabilization, with the inclusion of other
related costs for con.truction bringing the con.truction costs to
approximately $780,000. Monitoring C08t is $75,000 each year for the
first two year. after implementation and $10,000 for each 8ucceeding year
for an additional 10 year..
6.4
COST EFnC'fIWnSS
Thi. alternative afford. a higher degr.. of overall effectivene.. in not
only protecting the public again.t direct expo.ure but in removing the
threat of future relea.e o~ contaminant.. The e.timated capital co.t of
this alternative i. $1.03 million (including operation and maintenance).
Thi. remedy i. a practical remedy which can be implemented year-round.
Operable Unit One, by providing .ource control and groundwater monitoring,
will allow an opportunity to implement anticipated activities in Operable
Unit Two which will addre.. contamination of groundwater on-.ite.
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6.5
SCHEDULE
Thi8 planned .chedule for remedial activitie8 at the Zellwood Groundwater
Contamination Site is as follows:
September, 1989 Amend December 11, 1987, ROD
September, 1989 Complete RD
January, 1990 Complete Monolith
June 1990 Complete In8tallation of Monitor Well8
7.0
COMPLIANCE WITH OTHER ENVIRONMENTAL LAWS
Section 121(d)(2)(A) of CERCLA incorporate. into law the CERCLA Compliance
Policy, which specifies that Superfund remedial actions meet any Federal
standards, requirements, criteria, or limitation. that are determined to
be legally applicable or relevant and appropriate requirements (ARARs).
Also included is the provi8ion that State ARAR8 must be met if they are
more stringent than Federal requirements.
The requirements of the National Environmental Protection Act (NEPA) have
been met. Additionally, the re8ults of these 8tudies are being presented
to the public through a public notice, and the public has been given the
opportunity to comment on the re8ult. of the .tudie. and the proposed plan.
for the remedial action.
. Occupational Safetv and Health Admini.tration
/OSHAI
A health and 8afety plan will be developed during remedial de.ign and will
be followed during field activities to as.ure that regulations of OSHA are
followed.
. Safe Driokioq Wa~e~ Act
/SDWA)
Additional groundwater studies will be conducted during Operable Unit
One. A fea.ibility .tudy to determine the appropriate clean-up
alternative will include mea.ures to en.ure conformance with the SDWA.
Any di.charge will be below the drinking water .tandard..
. National Pollutant Di.charoe Elimination Sv.tem
(NPDES)
The cho.en alternative doe. not include any discharges, therefore this
requirement doe. not apply.
. Clean Water Act
50il remediation i. aimed at .ource control, and implementation of the
recommended alternative would result in an end to potential contamination
of .urtace water.
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Resource Conservation and Recoverv Act
I 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 Di8posal Re8trictions (LORs) are,
however, applicable to remediation of contaminated soils. The LORs
are applicable to the waste on-site if the .oils are excavated and
removed or excavated and treated. In alternatives where the LDRs are
applicable, the 80il must be treated to the interim treatment levels
prior to land disposal.
Although the recommended remedy for soil/8ediment contamination i8
not regulated under RCRA' in 80me in8tances, it may be considered
"treatment" of hazardous waste. However, this action is treatment of
hazardous substances under CERCLA, not hazardous wa8te. Therefore,
. LDR does not apply. Neverthele8s, all solidification/8tabilization
activities will take place within a confined corrective actio~
management unit (CAMU), and RCRA land disposal-type requirements will
be 8ub8tantially met. .
Florida Department of Environmental Reaulation IDER)
compliance ~ith other 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 a. well a. monitor the monolith for a period of
twelve years to en.ure that the metals are not leaching into the
groundwater.
8.0
COMMUNITY RELATIONS HISTORY
The following community relation. activities were performed at the
Zellwood G~dwater COntamination Site:
.
A Pact'Sh..t on the Site wa. prepared in November 1986.
A COmmunity aelation. Plan wa. de~eloped and implemented.
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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 pre.s relea8e providing an opportunity for a public meeting and
info~ation on the opening of the public comment period has been
issued August, 1989.
Public notices providing the same information will run in the morning
and evening editions of the Orlando Sentinel, a daily paper
dete~ined to be the most widely read in the area.
9.0
STATE INVOLVEMENT
A8 required by CERCLA, Section 104(C), the State must aS8ure payment of
ten percent of all costs of remedial action if performed by EPA. Remedial
action has been defined in SARA as including all construction and
implementation activities until 8ite remediation is completed. Activitie.
required to maintain the effectiveness of the remedy following completion
of the remedial action is considered operation and maintenance (O&M). The
State is required to pay 100 percent of all O&M 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.
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APPENDIX A
SOIL ANALYTICAL DATA
FROM MARCH, 1988
METALS AND CYANIDE
PESTICIDES
EXTRACTABLE ORGANICS
PURGEABLE ORGANICS
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METALS AND CYANIDE
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LAI STATION
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EXTRACTABLE ORGANICS
-46-
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PURGEABLE ORGANICS
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-------
RESPONSIVENESS SUMMARY
This summary presents all of the Agency's responses to relevant comments
received from the inter~8ted 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 80ils on-site to prevent the
organic and metal contamination from leaching into the 8urrounding 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
bifurcation of this action is being taken in response to the Florida Department
of Environmental Regulation's CFDER) 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. Thi6 responsiveness .ummary will forcus on the comments from the
attorney for Drum Service. The comments received from the attorney for pouglas
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 Period and
Agency Responses.
Remaining Concerns.
B.
BACKGROUND ON COMMUNITY INVOLVEMENT
Community interest in the Zellwood Groundwater Site has been very limited
dating back to September 29, 1986 when EPA held a public meeting at the
Zellwood Elemen~ary School. Pour letter. were received by EPA following the
public meeting, thr.. frOll 1fttere.ted citizen. and one frOll a PD. pollowing
the meeting, Era 88t up repo.itorie. at the Zellwood Ilementary School and at
EPA Regional Otf1c8. 1ft Atlanta', Georgia. The minute. of the public ..eting
have been plac8d 1ft the Admini.trative Record at both repo.itorie.. The
administrative record at the repo.i~orie. have been updated when new relevant
information hae become available. On september 5, 1989 BPA i..ued a public
notice in The Orlando Sentinel informing the Public of the fundamental change
to the December 1987 Record of Deci.ion. Pa~ .h..t. were ..nt to all
intere.ted pa~ie., PD., local media and official.. BPA received
-52-
-------
one 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
information previously placed in the repository at the Zellwood Elementary
School was missing. As a result, EPA replaced these materials and began
updating the information that had previously been put into the Administrative
Record and EPA Library for the Zellwood Groundwater Contamination Site.
C.
SUMMARY OF COMMENTS RECEIVED DURING PUBLIC COMMENT PERIOD AND AGENCY
RESPONSES
EPA mailed the Notice of Fundamental Change Fact Sheet to all interested
parties on September 29, 1989. EPA received two responses, one from the
Attorney for Drum Service Company of Florida, one from the Attorney for
Douglass Fertilizer. 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 will follow the same 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 available 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 Repository, 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.
EPA Response: Since the public meeting in 1986, EPA has maintained an
Administrative Record in Repositories at the Ze11wood 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 recognize. that one purpo.e of the repositories is to provide
interested parties with sufficient relevant information supporting Agency's
choice ot 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 partie.. Upon di.covery, the missing documents were replaced with
copies from the Atlanta Repository. As a result, all of the items that were
intended to be in the Zellwood Repository may not have been placed there before
the release of the public notice. However, the information was replaced on
september 29, 1989 and was alway. available in the Atlanta Repository and
through the Florida DER. Further, EPA had mailed the Notice of Fundamental
Change and Fact Sheet to all intere.ted group. and individuals in OCtober,
1989. Thi. notice referred the recipients to contact person. 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
proprietary information. Based on the comments in the PRPs letter, it appears
the PRP took 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 Atlanta 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 .upporting the Agency'8
decision concerning the remedial alternative cho.en 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. Memorandum8 1, 3, and 4 were not considered in
the decision process while memorandum 2 wae u.ed to determine the 8011 clean-up
levels protective of a Cla8s II Ground Water. Although the levels repre8ented
in memorandum 4 were modified to allow for the lead and chromium leve18 to be
higher based on the fact that the leachate concentrations of lead and chromium
in 80il would not lead to groundwater contamination Above drinking water
8tandards at the concentration. li.ted 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. A8 such, it i. a predeci8ional
document and not available for review. However, the Fact Sheet sent out with
the Notice of Fundamental Change de.cribed the changes that were being
considered for the amended ROD. Also, ba.ed on the comments in his letter, the
PRP had apparently received a copy of the draft Amended ROD a8 well as the
materials he discussed in his letter from the Florida DER under the Sunshine
Law.
The PRP's la.t comment under this heading addre..ed the length of the 10 day
comment period 8et for re.pon.e. to the changes pre.ented in the Amended ROD.
The primary difference between the original ROD and the Amended ROD i. the
choice of the remedy for the Site. The information and fact. pre.ented are the
.ame for both documents. Since the change. to the ROD were not exten.ive and
intere.ted partie. had .ufficient relevant information to review and comment on
the.e change., it i. the &PA'. opinion that a 10 day comment period wa.
adequate to addr8a8 the change. and not arbitrary and capricious a. .ugge.ted
by the PRP.
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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 based 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 site, 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 goala for the site, both to be protective of
human health and the environment on a long-term basis. In summary, these
levels in no w»y can b« specified as arbitrary and capricious as the PRP has
stated in their comments.
The PRP also questioned the us* of the PRZM model in EPAs estimation of a
clean-up goal for the sit*.
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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 Technoloqy 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 eoil
remediation goals took into account the partitioning behavior of the pesticides
based upon their solubility and the octanol/water partitioning characteristics
of these 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 eet at very low concentrations, the result ie 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),
(31 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-Bite remedy. Off-Bite
disposal would be acceptable only if on-Bite treatment i. not feaBible, 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 -experimental for organic compounds- and
"innovative for ..tals-.
EPA ResDens.. !be remediation alternative has been analyzed in the laboratory
with extensive leachate te.t. on the .oil for both organic. and metals. The
results prove tb8 remedy cho..n vill mitigate the po.1bility of organic. and
metals cont&mia&tion entering the surrounding groundwater above the drinking
water .tandard. ..t by the State of.rlorida. Therefore the alternative meets
Agency requirements in that the enviro~ and public are being protected.
Solidification of the contaminated soils on site i. the be.t 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 site at this tLme
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 been the focus of Operable
Unit 11 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 '2.
4.
Clean-up Goals.
The PRP cla~s 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
levela found in other materials, the removed materials should be placed in a
solid waste landfill; and other sites and RODs 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 a. appropriate model.. All of this
information i. 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 90als were set in accordance with the provisions of
CERCLA. In support of their allegation, the PRP sugge.ted that although there
were high level. of lead, other values of lead were lower and in a range
acceptable in ather .ituation.. The PRP then refer. to .tandards .et in
.everal other countries and in a 1986 IPA .tudy. The fact i. that .one of the
data repre.ent. .ample. taken from area. that may have had low level. of
contamination. However, there were also unacceptable, high level. ot lead (as
well a. other metals and substances) pre.ent at the Site.
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This argument is similar to the PRPs next comment concerning the use of average
values in place of absolute values of the data for certain metals in
determining the clean-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 volitilization of the soils caused by heat should result in lower
levels of contamination which is not the case at this Site.
The PRP'e 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 is 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 tin* 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, etc. 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. Miscellansxmo.
The PRP mentions that they have mad* significant and enormous changes to the
plants and businessess over the past 15 years to prevent further pollution of
the environment. The PRP stated that BPA has neglected to account for this in
the contaminant levels dropping at the sit*.
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[PA Re8POn8e: EPA recognizes the advancement the PRPs have made in the manner
in which they handle their wastes and obvious growth the PRPs have experienced
over t~, years; but in no way does this account for the reduction of waste
contam: ation. The PRPs are becoming aware of the serious liability involved
in rele~sing waste into the environment and taking precautions to prevent any
further releases. However, the advancement and modifications to the businesses
does not remediate the contamination previously released by any industry or
business nor does it relinquish the companies from their responsibility for
remediation of the site. From a hydrological stand point the levels of organic
contaminants may have been reduced over the years due to the large transfer of
groundwater through the soil, in essence, flushing the organics out of the area
and diluting the contaminants over time.
D.
REMAINING CONCERNS
EPA is mainly concerned with the contamination on site migrating into the
groundwater that may be used for public water supply. FDER has raised concerns
with the PRPs and EPA concerning the Floridian Aquifer and its present
condition as well as stressing that they would not recommend further conduits
into the aquifer from the Zellwood site. Further studies may be needed to
confirm the concentration of contaminants or lack of contaminants from the site
into the Floridian aquifer before the site can be deleted from the NPL. This
issue will be brought to the table in the future once Phase II of the remedial
investigation is completed by EPA. The citizens have not raised any concerns
since the October 5, 1989 public notice. EPA plans to keep the public and
local officials informed of the activities EPA is undertaking at the site along
w~th any new information that may involve the site.
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