PB96-964017
EPA/ROD/R04-96/274
October 1996
EPA Superfund
Record of Decision:
Wingate Road Municipal
Incinerator Dump and Landfill Site,
Fort Lauderdale, FL
5/14/1996
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RECORD OF DECISION
FOR THE
WINGATE ROAD MUNICIPAL INCINERATOR AND LANDFILL SITE .
THE DECLARATION
SITE NAME AND LOCATION
Wingate Road Municipal Incinerator And Landfill Site .
Fort Lauderdale, Broward County, Florida
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action
for the Wingate Road Site in Fort Lauderdale, Florida. This
remedial action is chosen in accordance with the Comprehensive
Environmental Response Compensation and Liability Act of 1980
(CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986, SARA 42 U.S.C. Section 9601 et.
seq.. and, to the extent practicable, the National Oil and
Hazardous Substance Pollution Contingency Plan (NCP). This
decision is based on the administrative record for this site.
The State of Florida, as represented by the Florida
Department of Environmental Protection (FDEP), has been the
support agency during the Remedial Investigation and Feasibility
Study process for the Wingate Road site. In accordance with 40
CFR 300.430, as the support agency, FDEP has provided EPA with
input during the process. Although FDEP has not indicated an
objection to the overall approach of the selected remedy, FDEP is
unwilling to concur with this ROD because FDEP disputes the
remediation goals selected for arsenic and dioxin in soil.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from
this site, if not addressed by implementing the response action
selected in this ROD, may present an imminent and substantial
.endangerment to public health, welfare, or the environment.
DESCRIPTION OF THE REMEDY
This remedy addresses the contaminated media at the site.
This remedy addresses the principal threat remaining at the site
by capping the landfill. The major components of the selected
remedy include:
* construction of a synthetic or clay cap with erosion
controls over the landfill,
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* excavation of contaminated soil and incinerator ash,
and disposal on the on site landfill,
* drainage, treatment, and disposal of water in Lake Stupid,
* excavation of Lake Stupid sediments, and disposal on the
on site landfill,
* storm water management
* construction of a vertical barrier between the
landfill and Rock Pit Lake,
* natural attenuation for the surface water at Rock Pit
Lake,
* decontamination of the buildings and structures,
* ground water, surface water, sediment, and fish tissue
monitoring,
* institutional controls and/ or ground water use
restrictions within the current site boundary, and
* institutional controls for the maintenance of the site
cap, storm water controls, fencing, and signs.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that
are legally applicable or relevant and appropriate to the
remedial action, and is cost effective. This remedy utilizes
permanent solutions but does not satisfy, for that portion of the
Site consisting of material already placed in the landfill and
for the material to be placed in the landfill, the statutory
preference for remedies -that employ treatment that reduce
toxicity, mobility, or volume as a principal element because: 1)
it would not be cost effective to treat the waste disposed of in
the landfill, 2) the selected remedy provides adequate protection
to human health and the environment, 3) the selected remedy for
that portion of the Site.consisting of material already placed in
the landfill and for the material to be placed in the landfill
complies with the Presumptive Remedy for CERCLA Municipal
Landfill Sites approved by OSWER Directive 9355.0-49FS and 4} the
waste material is not a RCRA hazardous waste.
OSWER Directive 9355.0-49FS establishes that the following
are the elements of a presumptive remedy for a municipal
landfill: 1) landfill cap, 2) source area groundwater control to
contain plume, 3) leachate collection and treatment, 4) landfill
gas collection and treatment, and/or 5) institutional controls to
supplement engineering controls. The remedy herein selected does
not include source area groundwater control to contain plume
because there is no known plume migrating from the Site. In
addition, the remedy does not include a leachate collection and
treatment system because the landfill material will remain in
place below the water table. Therefore, it would be futile to
have a leachate collection and treatment system as part of this
remedy. In the event that groundwater exceedences of Maximum
Contaminant Levels (MCLs) are observed beyond the current Site
boundary, the groundwater portion of the selected remedy will be
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reevaluated.
Because this remedy will result in hazardous substances,
pollutants, and contaminants remaining on site above levels that
allow for unlimited use and unrestricted exposure, a review will
be conducted within five years after commencement of the remedial
action to ensure that the remedy continues to provide adequate
protection of human health and the environment. These reviews
will be conducted every five years or until remediation goals are
achieved.
\\V W\
Richard D, Green, Acting Director
Waste Management Division
Date
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RECORD OF DECISION
Decision Summary
Wingate Road Municipal Incinerator and Landfill NPL Site
Fort Lauderdale, Broward County, Florida
1.0 Site Location and Description
The Wingate Road Municipal Incinerator and Landfill NPL Site
(the site) is located at 1300 NW 31st Avenue, Fort Lauderdale,
Broward County, Florida (see Figure 1, Site Location Map). The
site is bordered on the west by NW 3lst Avenue, to the north by a
privately owned junk yard, to the northeast by a privately owned
lake known as Rock Pit Lake, and to the east and south by
residential properties (Figure 2, Study Area Map).
The site is approximately 60 acres in size and includes two
inactive incinerator buildings, cooling water treatment
structures, an ash and solid waste landfill, a vehicle
maintenance area, and various buildings. The study area also
includes the cooling water percolation pond, known as Lake
Stupid, and Rock Pit Lake which historically received overflow.
from Lake Stupid. The site is owned and was operated by the City
of Fort Lauderdale.
The landfill area is approximately 40 acres in size, 35 feet
above sea level (25 feet above surrounding grade), and is densely
overgrown with brush and trees. The remaining 20 acres is known
as the southern portion of the site. The site is currently leased
by the city to Fort Lauderdale Production Central, Inc., which
uses the site for film support and production activities.
2.0 Site History and Enforcement Activities
The site was purchased by the City of Fort Lauderdale in
1951. The municipal incinerator and landfill operated from 1954 •
through June 1978. The facility processed approximately 480 tons
of municipal solid waste per day. Two incinerators were
constructed on site; the "old" incinerator in 1954, and the "new"
incinerator in 1966. The old incinerator consisted of two
furnaces and did not use cooling water until 1975. The new
incinerator became operational in 1966 and included two parallel
incinerators and a cooling water percolation pond. The cooling
water percolation pond lost permeability due to the buildup of
fine ash and was subsequently named Lake Stupid. The city
periodically removed the ash from the bottom of Lake Stupid and
placed the ash in the landfill or around the banks of the pond.
Lake Stupid was then connected to Rock Pit Lake by an overflow
ditch located along the eastern edge of the landfill.
The cooling water treatment system was constructed in 1975.
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CD
POUPAHO PARK
RACE TRACK
CYPRCSS CRUK SO.
FT. LAUDEROAU EXECUTW
AIRPORT
COUWERCIAL BLVD.
OAKLAND PARX BLVD.
0 1000 2000 MOO
ountc SCAIT M rm
FIGURE: 1
SITE LOCATION
W1NGATE ROAD MUNICIPAL INCINERATOR
AND LANDFILL SITE
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GRAPHIC SCALE
cmcTDrr
0 125 250 500
SCAli 1* - 500'
nmmr
FIGURE: 2
STUDY AREA
WINGATE ROAD MUNICIPAL INCINERATOR
AND LANDFILL
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The system was designed to remove the ash from the cooling water
before the water was discharged to Lake Stupid. The resultant
sludge from the water treatment system was disposed of in the
landfill along with the ash from the incinerators.
The EPA conducted a site inspection and developed a Hazard
Ranking System Report for the site in 1985. The City of Fort
Lauderdale began closure of the landfill in 1986 in accordance
with Florida Administrative Code (FAC) requirements. The site was
placed on the National Priorities List (NPL) in 1990 with a
Hazard Ranking System (HRS) score of 31.72. Closure of the
landfill was delayed until the Remedial Investigation and
Feasibility Study (RI/FS) could be completed.
The City of Fort Lauderdale and the Port Everglades
Authority entered into, an Administrative Order on Consent (AOC)
with the EPA in 1991 to conduct the RI/FS. Four phases of field
investigation were conducted from August 1992 through September
1994. Approximately 300 samples of soil, sediment, surface water,
ground water, and incinerator ash residue were collected during
Phase I. Phase Ila was conducted to assess the distribution of
dioxins and furans (dioxin) and included fish tissue samples.
Phase lib was conducted to provide quality assurance regarding
the metals data from the Phase I water samples, and to collect
additional samples for dioxin .analysis from the drainage ditch
that historically connected Lake Stupid to Rock Pit Lake. Phase .
Ill was conducted in September 1994 to assess the potential
impact of off site deposition of flyash from the historic
incinerator stack emissions.
The RI/FS analyzed the different remedial alternatives under
the nine point criteria that the National Contingency Plan
establishes for the selection of a remedy. The RI/FS analysis
corroborated that the Presumptive Remedy for CERCLA Municipal
Landfill Sites approved by OSWER Directive 9355.0-49FS for that
portion of the Site consisting of material already placed in the
landfill and for the material to be placed in the landfill was
the appropriate remedy to be selected for the Site.
3.0 History of Community Participation
EPA began its community relations efforts in April 1992 by
conducting community interviews and holding a public meeting at
the Fort Lauderdale Branch Public Library at 1300 East Sunrise
Boulevard. This meeting was held to address concerns of the
citizens and to inform them of EPA's planned RI/FS activities.
Additional meetings were held with local citizens in March 1993,
and again in February 1994 to discuss the results of the Remedial
Investigation.
A public comment period for the proposed remedial action was
held from December 7, 1994 through January 6, 1995. On December
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5, 1994 a Proposed Plan fact sheet was released to the public to
inform the public of EPA's findings and to notify the public that
they could review details of the RI/FS reports at the Fort
Lauderdale Main Library. Additionally, a public meeting was held
on December 12, 1994 at the Bass Park Community Center, located •
at 2750 NW 19th Street in Fort Lauderdale. At this meeting, EPA
and the Agency For Toxic Substances and Disease Registry (ATSDR)
presented the results of the RI/FS, and answered questions about
the site and the remedial alternatives under consideration. A
response to the comments received during this period is included
in the Responsiveness Summary, which is part of this Record of
Decision (ROD). This decision document presents the selected
remedial action for the Wingate Road site in Fort Lauderdale,
Florida, chosen in accordance with CERCLA, as amended by SARA,
and to the extent practicable, the National Contingency Plan. The
decision for this site is based on the Administrative Record.
4.0 Scope and Role of Response Action
. This ROD presents the planned remedial activities for the
site. The remedy will address the contaminants present in the
surface soil, incinerator ash residue, landfilled material,
sediment, ground water, and fish tissue associated with the site.
The purpose of this remedy is to reduce the risks associated with
exposure to contaminated media to health based levels and to
protect the surficial aquifer system beyond the current site
boundary. This ROD is the only ROD anticipated for this site
since the contamination present at the site will be addressed as
a single operable unit.
5.0 Summary of Site Characteristics
Broward County occupies approximately 1220 square miles of
the southern Florida peninsula. The physiography of the county
includes coastal sand dunes overlying the Atlantic Coastal Ridge,
the everglades, and the sandy flatland located between the
Atlantic Coastal Ridge to the east and the everglades to the
west. The Wingate Road site is located in the sandy flatland of
eastern Broward County.
The topography of the county is flat. Elevations range from
zero to 25 feet, with most land at 5 to 10 feet above mean sea
level. The land generally slopes slightly to the southeast.
The climate in the area is semi-tropical to.tropical with an
average annual temperature of 73 degrees (F). Average rainfall is
approximately 60 inches per year with most precipitation falling
between June and October. January is the driest month, with
average rainfall of 2.2 inches, whereas September averages 8.5
inches of precipitation. The predominant wind direction is from
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the southeast.. The primary drainage features in Broward County
include tidal streams, borrow pits, water conservation areas, and
manmade canals. The drainage system is controlled by the South
Florida Water Management District, the Broward County Water
Resources Department, and local drainage districts.
Surface drainage on site is controlled by the site
topography, lakes, and paved areas. Precipitation which falls on
the southern portion of the site is routed through a storm water
management system to Lake Stupid, and percolates from the lake
into the ground water. Precipitation which falls on the landfill
infiltrates through the landfill material. Lake Stupid and Rock
Pit Lake are hydraulically connected to ground water, have no
surface water outlets, and apparently do not overflow during
storm events. The nearest surface drainage to the site is the
North Fork of the New River which passes approximately one half
mile south of the site. The Middle River Canal passes
approximately two miles north of the site. Both canals flow east
to the Intracoastal Waterway.
5.1 Regional and Site Hydrogeology
The South Florida Peninsula is underlain by a wedge of
sediments that thickens toward the south, exceeding 15,000 feet
thick beneath the site. These sediments are underlain by
metamorphic and igneous rocks similar to those of the Appalachian
region.
The geologic units of interest to this site are three groups
of sediments. The upper unit is the Biscayne aquifer which is
comprised of a sequence of limestones with varying mixtures of
shell and sand. The Biscayne aquifer extends from the water table
to depths of 200 feet or more beneath .the surface. The Biscayne
is a prolific source of water and provides all potable water in
Broward County.
Underlying the Biscayne aquifer are 600 to 800 feet of
silty, sandy clays and marls which are known as the intermediate
confining unit. The confining unit effectively separates ground
water circulation within the Biscayne from the Floridan aquifer
below.
The Floridan aquifer contains carbonate rocks that extend
downward from a depth of approximately 1,000 feet in the area of
the site. The Floridan contains confined water with 30 to 60 feet
of head above sea level. Water in the Floridan aquifer in this
area is highly mineralized and is not suitable for potable water
supply.
In the vicinity of the Wingate Road site, the upper portion
of the Biscayne aquifer consists of approximately 50 feet of fine
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to medium grained quartz sand with stingers of calcareous
sandstone. A thin, marly shell bed zone was found at depths of 46
to 66 feet below land surface. A crystalline, sandy limestone was
found at 66 feet below land surface; this limestone represents
the top of the major water producing zone of the Biscayne
aquifer.
Ground water within the Biscayne aquifer generally flows
toward the east and southeast. Regional flow can be influenced
locally by the effects, of pumping wells and by drainage canals.
Local ground water flow at the site is influenced by the landfill
topography. A slight mounding of the water table develops beneath
the landfill, resulting in a radially- outward flow of ground
water. The mounding effect does not appear to influence the
ground water flow pattern beyond the site.
5.2 Nature and Extent of Contamination
The Remedial Investigation included four phases of field
investigation which were conducted from August 1992 through
September 1994. Approximately 300 samples of soil, sediment,
surface water, ground water, and incinerator ash residue were .
collected during Phase I. Phase I was conducted to assess the
nature and extent of contaminants in the four areas of
contamination at the site; the landfill, the southern portion of
the site, Lake Stupid, and Rock Pit Lake. The Phase I samples
were analyzed for purgeable hydrocarbons, semi-volatile organic
compounds, pesticides and PCBs, and target analyte list (TAL)
metals. Select Phase I samples were also analyzed for dioxin. The
results of Phase I identified dioxin in the soil and sediment
associated with the site. Phase Ila was conducted to assess the
distribution of dioxin. Phase lib was conducted to provide
quality assurance regarding the metals data from the Phase I
water samples, and to collect additional samples for dioxin
analysis from the drainage ditch that connected Lake Stupid to
Rock Pit Lake.
Phase III was conducted in September 1994 to assess the
potential impact of off site deposition of flyash from the
historic incinerator stack emissions. The purpose of the off site
sampling was to determine if dioxin or metals from the
incinerator emissions had been deposited in residential areas in
concentrations which would pose a risk. Phase III also included
sampling of sediment and ash from on site for Toxicity
Characteristic Leachate Procedure (TCLP) metals analysis.
5.2.1 Surface Soil / Ash Residue Investigation
The primary source areas at the site include the areas and
structures which contain ash or ash residue from the incineration
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process. The source areas investigated include the incinerator
buildings, the landfill, the cooling water treatment system
structures, soils, sediments,.and the onsite drainfields and
disposal areas. A total of 68 surface soil/ ash samples were
collected during the Remedial Investigation.
The predominant contaminants identified in the landfill and
the onsite surface soils and ash residue are lead, arsenic,
benzo(a)pyrene, beryllium, and dioxin (a comprehensive list of
all compounds detected above background concentrations is
included in the Remedial Investigation and Baseline Risk
Assessment reports). As shown on Table l, lead was detected at
concentrations of up to 10,768 parts per million (ppm) . The lead
concentration was highest in the ash residue sample collected
from the flocculation basin, with lead concentrations above clean
up goals also being detected in the other water treatment system
structures, in the incinerator buildings, and, in the surface
soils on the southern portion of the site and on the landfill.
Arsenic was detected at concentrations of up to 211 ppm in the
central settling basin. Arsenic, concentrations above the clean up
goal were also detected in the other water treatment structures,
and in the incinerator buildings. Benzo(a)pyrene was detected at
concentrations of up to 0.99 ppm on the landfill. Benzo(a)pyrene
was also detected above the clean up goal in the surface soil on
the southern portion of the site and in the east settling basin.
Beryllium was detected at concentrations of up to 1.7 ppm in the
surface .soil on the southern portion of the site. Beryllium was
also detected above the clean up goal on the landfill and in the
sludge bed. Dioxin was detected at concentrations of up to 0.054
ppm TEQ in the old incinerator building.
Phase III of the Remedial Investigation included collection
of twenty (20) surface soil samples from the residential areas
surrounding the site. The purpose of the off site sampling was to
determine if dioxin or metals from the incinerator emissions had
been deposited in residential areas in concentrations which would
pose a risk. None of the off site soil samples were found to
contain levels of dioxin or metals which exceed the site
remediation goals.
Phase III also included, sampling of sediment and ash from on
site for TCLP metals analysis. Five representative samples were
collected from Lake Stupid sediments and from the incinerator
buildings and water treatment system structures. None of these
samples exceeded the regulatory limits for TCLP metals.
5.2.2 Subsurface Soil Investigation
Subsurface soil samples were collected from 21 soil borings
on the southern portion of the site. Lead was detected at
concentrations of up to 5,360 ppm, and arsenic at up to 31 ppm,
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TABLE 1
CONTAMINANTS OF CONCERN IN ONSITE SURFACE SOIL/ASH RESIDUE
CONTAMINANT
LEAD MG/KG
ARSENIC MG/KG
BENZO(A)PYRENE MG/KG
BERYLLIUM MG/KG
DIOXINS MG/KG (TEQ)
FREQUENCY OF
DETECTION
67/68
64/68
3/64
12/64
25/25
RANGE OF DETECTED
CONCENTRATIONS
1.6-10,768
0.2-211
0.85-0.99
0.2-1.7
0.0000006-0.054
BACKGROUND
CONCENTRATIONS
1.5-58.5
1.4
*ND
*ND
0.00000012
*ND = NOT DETECTED
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in subsurface soil samples collected from the drainage area north
of Lake Stupid. Benzo(a)pyrene was detected at concentrations of
up to 7.4 ppm in a subsurface sample from the vehicle maintenance
area. And, beryllium was detected at concentrations of up to 0.6
ppm in a subsurface soil sample collected from the drainage area
north of Lake Stupid.
5.2.3 Surface Water Investigation
Water samples were collected from two surface water bodies
and associated ditches. Lake Stupid is a shallow pond located in
the southeast corner of the site. A ditch was constructed along
the east side of the landfill to connect Lake Stupid to Rock Pit
Lake. Rock Pit Lake is a borrow pit lake and was constructed in
the 1950s and 60s. The lake has nearly vertical sidewalls on the
west, east, and south sides; the north side of the lake has a
sloping bank. Rock Pit Lake is approximately 60 feet deep. The
ditch which connected the lakes was partially plugged after the .
site operations were stopped.
As shown on Table 2, the predominant contaminants identified
in the surface water samples are lead, aluminum, beryllium,
antimony, cadmium, copper, silver, zinc, and iron. The chronic
ambient water quality criteria (AWQC) for lead was exceeded in
all surface water samples collected from Lake Stupid, and in one
surface water sample from Rock Pit Lake. Aluminum concentrations
exceeded the chronic AWQC in two Lake Stupid water samples, a
sample from a drainage area leading to the bank of Lake Stupid,
and in the samples from the drainage area leading to Rock Pit
Lake. The State of Florida criteria for beryllium was exceeded in
three Lake Stupid water samples and in all of the Rock Pit Lake
water samples. The AWQCs for antimony, cadmium, copper, silver,
zinc, and iron were also exceeded in the two samples collected
from the drainage area leading to Rock Pit Lake.
5.2.4 Sediment Investigation
Sediments from two surface water bodies and associated
ditches were sampled during the investigation (surface water and
sediment samples were collected from the same locations). The
predominant contaminants identified in the sediments are dioxin,
toxaphene, antimony, arsenic, and cadmium. As shown on Table 3,
dioxin was detected at concentrations of up to 0.0029 ppm TEQ in
the sediment in Lake Stupid. Toxaphene was detected at 2.9 ppm in
sample LSD-04, which was collected from the sediment in the ditch
located north of Lake Stupid. Antimony was detected at
concentrations of up to 390 ppm, arsenic was detected at
concentrations of up to 68 ppm, and, cadmium was detected at
concentrations of up to 449 ppm in sediment samples from Lake
Stupid and the ditch north of Lake Stupid. Antimony and cadmium
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TABLE 2
CONTAMINANTS OF CONCERN IN SURFACE WATER
CONTAMINANT
ug/1
LEAD
ALUMINIUM
BERYLLIUM
ANTIMONY
CADIUM
COPPER
SILVER
ZINC
IRON
MERCURY
FREQUENCY
OF DETECTION
8/12
5/7
6/10
6/7
6/7
4/12
2/2
10/12
12/12
1/2
RANGE OF
DETECTED
CONCENTRATIONS
11-2,480
150-25,055
. 2-3
10-65
0.3-37
5-718
10-16
20-3,760
27-31,216
0.9
BACKGROUND
CONCENTRATIONS
3.6-25
ND
2
61-229
ND
6-10
8.3-23
20
40-206
ND
*ND = NOT DETECTED
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TABLE 3
CONTAMINANTS OF CONCERN IN SEDIMENT
CONTAMINANT
DIOXINS
MG/KG(TEQ)
TOXAPHENE MG/KG
ANTIMONY MG/KG
ARSENIC MG/KG
CADMIUM MG/KG
FREQUENCY
OF DETECTION
13/13
• 1/21
16/38
35/38
33/38
RANGE OF
DETECTED
CONCENTRATIONS
0.0000001-0.0029
2.9
8-390
0.5-68
1-449
BACKGROUND
CONCENTRATIONS
NA
ND
ND
0.3-6.5
0.5-2
*ND = NOT DETECTED
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were also found at levels above the remedial goals in Rock Pit
Lake sediments.
5.2.5 Fish Tissue Investigation
Fish tissue samples were collected from Lake Stupid and Rock
Pit Lake during Phase Ila of the RI. The tissue samples were
analyzed for dioxin and mercury. Dioxin was detected in whole
body fish tissue samples from Lake Stupid at concentrations of up
to 6.62 parts per trillion (ppt) TEQ. Dioxin was detected in
whole body fish tissue samples from Rock Pit Lake at
concentrations of up to 1.86 ppt TEQ. Fish fillet samples (i.e.;
the edible portion of the fish) from Rock Pit Lake.contained
dioxin at concentrations of up to 0.07 ppt TEQ.
5.2.6 Ground Water Investigation
Thirty eight (38) ground water monitoring wells were sampled
during the RI. Well clusters generally include three wells, with
one well each to monitor the top of the Biscayne aquifer
(approximately 20 feet deep) , an intermediate, depth
(approximately 50 feet deep), and a portion of the producing zone
of the aquifer used by water supply wells (90 feet deep) . Nine
monitoring wells were installed in the area of an underground
storage tank excavation located on the southern portion of the
site near the vehicle maintenance area. Four private wells were
also sampled during Phase Ila of the RI to assess the potential
for off site migration of contaminants from Rock Pit Lake, the
landfill, and Lake Stupid.
As shown on Table 4, the predominant contaminants identified
in the ground water on site are bis (2-ethylhexyl)phthalate,
benzene, lead, antimony, cadmium, aluminum, manganese, and
mercury. Bis(2-ethylhexyl)phthalate was detected at
'concentrations of up to 480 parts per billion (ppb) in monitoring
well MW-5B, located at the southern edge of the landfill; Bis(2-
ethylhexyljphthalate was also detected above the federal MCL in
monitoring wells MW-2C and MW-10A, located at the eastern edge of
the landfill. Benzene was not detected above the federal MCL of 5
ppb (benzene was detected at up to 2 ppb in ground water samples
collected from the vehicle maintenance area). Lead was detected
at concentrations of up to 49 ppb in monitoring well MW-8A,
located on the southern portion of the site immediately west of
Lake Stupid. Lead was also detected above the MCL in monitoring
wells MW-2A and MW-10A, located at the eastern edge of the
landfill. Antimony was detected at 15 ppb in MW-8A. Cadmium was
detected at concentrations of up to 39 ppb in well MW-8A. Cadmium
was also detected at 6 ppb in MW-10A, located at the eastern edge
of the landfill, and at the MCL of 5 ppb in several monitoring
wells on the southwestern portion of the site. Additionally,
8
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TABLE 4
CONTAMINANTS OF CONCERN IN GROUNDWATER
(UG/L)
CONTAMINANT
UG/L
BIS(2-ETHYLHEXL)PHTHALATE
BENZENE
ALUMINUM
ANTIMONY
CADMIUM
LEAD
MANGANEGE
MERCURY
FREQUENCY
OF DETECTION
8/38
3/38
31/38
4/38
8/38
19/38
34/38
5/38
RANGE OF
DETECTED
CONCENTRATIONS
5-480
1-2
248 - 76,720
4-15
4-39
2-49
2 - 2,800
0.2-2.5
BACKGROUND
CONCENTRATIONS
32
ND
290 - 2,012
ND
5-6
ND
21-65
ND
•ND = NOT DETECTED
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aluminum was detected at concentrations of up to 76,720 ppb,
manganese was detected at concentrations of up to 2,800 ppb, and,
mercury was detected at concentrations of up to 2.5 ppb in the
ground water on site.
6.0 Summary of Site Risks
Actual or threatened releases of hazardous substances from
this site, if not addressed by implementing the response action
selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare,
or the environment.
The Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA) directs EPA to conduct a baseline risk
assessment to determine whether a NPL site poses a current or
potential threat to human health or the environment in the
absence of any remedial action. The baseline risk assessment
provides the basis for taking action and indicates the
contaminants and the exposure pathways that need to be addressed
by the remedial action. This section of the ROD contains a
summary of the results of the baseline risk assessment conducted
for this site.
6.1 Contaminants of Concern
Chemicals which were evaluated in the risk assessment are
referred to as chemicals of potential concern (COPCs). The
selection of COPCs is based on several factors including chemical
toxicity, prevalence, and concentration. Chemicals were included
in the Summary of Site Risk section of the Risk Assessment if the
results of the risk assessment indicate that a COPC might pose a
significant current or future risk. These chemicals are referred
to as. contaminants of concern (COCs). Chemicals are not included
if their individual carcinogenic risk contribution is less than
IE-6 or their noncarcinogenic hazard quotient is less than 0.1 .
6.2 Exposure Assessment
Whether a chemical is actually a concern to human health and
the environment depends upon the likelihood of exposure, i.e.,
whether the exposure pathway is currently complete or could be
complete in the future. A complete exposure pathway (a sequence
of events leading to contact with a chemical) is defined by four
elements. An exposure pathway is considered complete if the
following four elements are present:
• A source and mechanism of chemical release,
-------
• A retention or transport medium (or media in cases
involving media transfer of chemicals),
• A point of potential human contact with the
contaminated medium (referred to as the exposure
point), and
• A route of exposure (e.g., ingestion) at the contact
point.
If all four elements are present, the pathway is considered
complete.
An evaluation was undertaken of all potential exposure
pathways which could connect chemical sources at the site with
potential receptors. All possible pathways were first
hypothesized and evaluated for completeness using the above
criteria. The current pathways represent exposure pathways which
could exist under current site conditions while the future
pathways represent exposure pathways which could exist, in the
future, if the current exposure conditions change.
The potential current exposure pathways are:
• Incidental ingestion of and dermal contact with
surface soil by workers and/or trespassers;
• Incidental ingestion of surface water in Rock Pit Lake
by swimmers;
• Ingestion of fish from Rock Pit Lake by nearby
residents;
• Incidental ingestion of and dermal contact with
subsurface soil by excavation workers;
• Incidental ingestion of incinerator building or water
treatment structure ash residue by workers or
trespassers.
The potential future exposure pathways are:
• Incidental ingestion of and dermal contact with surface
soil by residents;
• Incidental ingestion of and dermal contact with
sediment in the drainage area north of Lake Stupid by
residents;
10
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• Ingestion of ground water from within the current Site
boundary by residents;
• Inhalation of and dermal contact with chemicals in
ground water by residents.
6.3 Toxicity Assessment
Toxicity values are used in conjunction with the results of
the exposure assessment to characterize site risk. EPA has
developed toxicity values for many carcinogens and
noncarcinogens.
Cancer slope factors (CSFs) have been developed for
estimating excess lifetime cancer risks associated with exposure
to potentially carcinogenic chemicals. CSFs, which are expressed
in units of (mg/kg/day)"1, are multiplied by the estimated intake
of a potential carcinogen, in mg/kg/day, to provide an upper-
bound estimate of the excess lifetime cancer risk associated with
exposure at that intake level. The term "upper bound" reflects
the conservative estimate of the risks calculated from the CSF.
Use of this conservative approach makes underestimation of the
actual cancer risk highly unlikely. Cancer slope factors are
derived from the results of human epidemiological studies or
chronic animal bioassays to which mathematical extrapolation from
high-to-low dose and uncertainty factors have been applied.
Reference doses (RfDs) have been developed by EPA for
indicating the potential for adverse health effects from exposure
to chemicals exhibiting noncarcinogenic effects. RfDs, which are
^expressed in units of mg/kg/day, are estimates of lifetime daily
exposure levels for humans, including sensitive individuals that
are likely to be without risk of adverse effect. Estimated
intakes of chemicals from environmental media can be compared to
the RfD. RfDs are derived from human epidemiological studies or
animal studies to which uncertainty factors have been applied
(e.g., to account for the use of animal data to predict effects
on humans). These uncertainty factors help ensure that the RfDs
will not underestimate the potential for adverse noncarcinogenic
effects to occur.
6.4 Risk Characterization
Human health risks are characterized for potential
carcinogenic and noncarcinogenic effects by combining exposure
and toxicity information. Excess lifetime cancer risks are
determined by multiplying the estimated daily intake.level with
cancer potency factor. These risks are probabilities that are
generally expressed in scientific notation (e.g., ixlCT4) . An
11
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excess lifetime cancer risk of ixlO"4 indicates that, as a
reasonable maximum estimate, an individual has a one in ten
thousand additional (above their normal risk) chance of
developing cancer as a result of site-related exposure to a
carcinogen over a 70-year lifetime under the assumed specific
exposure conditions at a site. EPA considers individual excess
cancer risks in the range of ixlCT* to IxlO"6 as protective;
however, the 1E-6 risk level is generally used as EPA's point of
departure when establishing clean up goals at NPL sites.
The potential for non-carcinogenic effects is evaluated by
comparing an exposure level over a specified time period (e.g.,
lifetime) with a reference dose derived for a similar exposure
period. The ratio of exposure to toxicity is called a hazard
quotient (HQ). An HQ<1 indicates that a receptor's dose of a
single contaminant is less than the RfD, and that toxic
noncarcinogenic effects from that chemical are unlikely. The
Hazard Index (HI) is generated by adding the HQs for all
chemical(s) of concern that affect the same target organ (e.g.,
the liver) within a medium or across all media to which a given
population may reasonably be exposed. An HI<1 indicates that,
based on the sum of all HQ's from different contaminants and
exposure routes, toxic noncarcinogenic effects due to
simultaneous exposure to all COCs are unlikely.
The HQ is calculated as follows:
Non-cancer HQ=CDI/RfD
where:
CDI=Chronic daily intake
RfD=reference dose
GDI and RfD are expressed in the same units arid represent
the same exposure period (i.e., chronic).
As shown on Table 5, the cumulative potential current
carcinogenic risk level for workers on the southern portion of
the site is 6E-6. The cumulative potential current carcinogenic
risk levels for trespassers on the southern portion of the site
and on the landfill are 2E-6, and 1E-4, respectively. The main
pathways responsible for these risk levels are incidental
ingestion of.and dermal contact with surface soil, due primarily
to the presence of dioxin, arsenic, and beryllium in the soil and
ash residue. The cumulative current noncarcinogenic hazard
indexes are less than 1. Therefore, noncarcinogenic effects are
unlikely under current land use conditions.
12
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TABLE 5
SUMMARY OF CUMULATIVE RISK ESTIMATES
RECEPTOR
CUMMULATIVE RISK ESTIMATES
Total Upper
Bound Excess
Lifetime Cancer
Risk
Cumulative
Hazard Index for
Noncarcinogenic
Effects
RISKS ASSOCIATED WITH CURRENT LAND-USE CONDITIONS
WORKER
Southern Portion
TRESPASSER
Southern Portion
Landfil
Nearby Resident Using Rock
Pit Lake
6x10"'
2x10'*
IxlO"4
3x10''
<1
<1
RISKS ASSOCIATED WITH FUTURE LAND-USE CONDITIONS
CHILD RESIDENT
Southern Portion
Drainage Area North of Lake Stupid
ADULT RESIDENT
Southern Portion
Drainage Area North of Lake Stupid
1x10*
IxlO/4
2xlO-$
9xlO"s
-------
The cumulative potential current carcinogenic risk level for
nearby residents using Rock Pit Lake is 3E-6, due primarily to
the presence of dioxin in fish tissue.
The cumulative potential future carcinogenic risk levels for.
child residents on the southern portion of the site and on the
drainage area north of Lake Stupid are IE-5 and 1E-4,
respectively, with cumulative future noncarcinogenic hazard
indexes greater than 1. These levels are due primarily to the
presence of benzo(a)pyrene, dioxin, arsenic, and beryllium in
surface soil; and, the presence of dioxin, toxaphene, arsenic,
antimony, and cadmium in the sediment in the drainage area.
The cumulative potential future carcinogenic risk levels for
adult residents on the southern portion of the site and on the
drainage area north of Lake Stupid are 2E-5 and 9E-5,
respectively, with a cumulative noncarcinogenic hazard index of
greater than 1 for the drainage area. These risk levels are due
primarily to the presence of dioxin, arsenic, and beryllium.
The potential future carcinogenic risk levels associated
with site ground water are IE-6 'for child residents and 3E-6 for
adult residents, due primarily to the presence of bis (2-
ethylhexyl)phthalate in site ground water. Ground water within
the current Site boundary exceeded Maximum Contaminant Levels
(MCLs) for bis(2-ethylhexyl)phthalate, aluminum, antimony,
cadmium, lead, manganese, and mercury. Ground water at the
current site boundary exceeded secondary MCLs (for aluminum and
manganese) only. Off site private water wells were not found to
exceed ground water MCLs.
A remedial goal of 500 ppm has also been established for
lead in surface soil. This level was given in the Baseline Risk
Assessment (BRA) as the value derived using exposure default
values in the UBK model (draft OSWER Directive #9355.4-08) as
referenced in the BRA document.
6.5 Environmental Risk
A qualitative risk assessment was conducted to determine if
contaminants present on site have impacted or can potentially
impact flora and fauna in the area. The results of the comparison
of chemical concentrations in surface soil with toxicity
reference values (TRVs) suggest the potential for impacts to
invertebrates from the presence of some metals on the southern
portion of the site and the landfill. Potential impacts to small
mammals and birds from the ingestion of earthworms were also
evaluated. On the southern portion of the site, the estimated
total dose a shrew would receive from the ingestion of earthworms
and soil is greater than the TRV for cadmium, suggesting that
impacts to shrews could potentially occur as a result of exposure
13
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to cadmium in this area. In the landfill area, the estimated
total doses of dioxin and.cadmium are greater than the TRVs,
suggesting potential impacts to shrews in this area. Potential
impacts to sensitive aquatic species in Lake Stupid are also
possible as a result of lead and aluminum in the lake water.
Apparently, there are no endangered species in the area.
6.6 Uncertainties
At all stages of the risk assessment, conservative estimates
and assumptions were made so as not to underestimate potential
risk. Nevertheless, uncertainties and limitations which may lead
to over- or under- estimation of risk are inherent in the risk
assessment process.
7.0 Description of Alternatives
The following alternatives represent a range of distinct
actions for addressing human health and environmental concerns.
The analysis presented below reflects the fundamental components
of the various alternatives considered feasible for this site.
Five remedial alternatives have been identified for evaluation:
Alternative 1. No action
Alternative 2. Restricted access
Alternative 3. Soil cover
Alternative 4. Single barrier landfill cap
Alternative 5. Double barrier landfill cap
7.1 Alternative 1; No Action
Under the no action alternative, the site would be left "as
is" and no funds would be expended to actively control or cleanup
the site related contamination. The potential risks posed by the
presence of contamination would not be minimized by this
alternative.
The remaining alternatives all require ground water use
controls in the form of a deed notice for ground water inside the
current site boundary. Additionally, the alternatives require
site monitoring for up to 30 years.
7.2 Alternative 2: Restricted Access
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Alternative 2 would include engineering controls to restrict
access to the site, and ground water monitoring for up to 30
years. A fence would be constructed around Lake Stupid and Rock
Pit Lake to limit access to surface water. The incinerator
buildings would be sealed to restrict access. All entrances,
windows and openings of each building would be closed off with
brick, concrete, or metal in a secure and permanent fashion. The
water treatment system structures would be decontaminated. The
method of decontamination would be determined by the construction
of each structure. Typically, the ash residue would be scraped
from the walls and floors and the contaminated surfaces would be
pressure washed. The collected decontamination water would be
treated for disposal.
7.3 Alternative 3: Soil Cover
Alternative 3 would include actions to reduce human contact
with the ash within the landfill, and to minimize potential
migration of contaminants through storm water runoff. A minimum
of 30 inches of native soil would be placed on the 40 acre
landfill, and grading would be modified to control surface water
runoff and infiltration, and to reduce leachate development. Lake
Stupid would be backfilled to eliminate contact with sediments
and to eliminate potential ecological exposure pathways. The lake
water would be removed for off-site treatment and disposal.
Residual ash from the southern portion of the site would be
excavated and placed in the landfill prior to construction of the
soil cover. The buildings and structures would be sealed and
decontaminated. This alternative would also include ground water
monitoring for up to 30 years.
7.4 Alternative 4; Single Barrier Cap
Alternative 4 would be designed to reduce human contact with
the landfill material, control erosion, and reduce infiltration
and leachate production. A landfill cap would be designed to meet
the requirements of Chapter 17-701 and 17-702 of the Florida
Administrative Code (FAC), including a single liner landfill cap.
A storm water management plan would be prepared to design the
grading plan, design the retention and detention ponds, and to
determine the discharges for storm water runoff. Lake Stupid
would be drained and excavated to eliminate human contact with
the sediments, and to eliminate the potential ecological exposure
pathways. The water would be treated and disposed of, and the
sediments would be excavated and placed on the landfill prior to
construction of the landfill cap. Excavation of Lake .Stupid
sediments shall continue horizontally until the remaining
sediment achieves the maximum contaminant concentrations noted in
section 9 below. Vertically, the excavation shall continue to a
depth of 24 inches, or until the remedial goals have been met,
15
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whichever depth is less. The excavated areas will be backfilled
with clean soil. A vertical barrier would be constructed between
the landfill and Rock Pit Lake. The vertical barrier would
prevent the migration of contaminants to Rock Pit Lake from the
landfill. It is expected that the surface water of Rock Pit Lake
would return to health based levels through natural attenuation.
Residual ash and contaminated soils from the southern
portion of the site would be excavated and placed on the
landfill. Soil excavation shall continue horizontally until the
remaining soil achieves the maximum contaminant concentrations
noted in section 9 below. Vertically, the excavation shall
continue to a depth of 24 inches, or until the remedial goals
have been met, whichever depth is less. The excavated areas will
be backfilled with clean soil.
The buildings and structures on the southern portion of the
site would be decontaminated and/or demolished, depending on the
planned use of the building locations and on the practicability
of decontaminating the buildings. The rubble and debris from any
demolished buildings and/ or process structures which require
demolition due to remediation or construction considerations will
be crushed and disposed of in the landfill. This alternative
would also include ground water monitoring, surface water
monitoring and monitoring of sediment and fish in Rock Pit Lake
for up to 30 years.
7.5 Alternative 5: Double Barrier Cap
Alternative 5 would include a landfill cap designed to
reduce human contact with the landfill material, control erosion,
and reduce infiltration and leachate production. The landfill cap
would be designed to meet the requirements of Subtitle C of the
Resource Conservation and Recovery Act (RCRA), including a double
liner landfill cap. Any demolished buildings, structures, and
excavated soils would be placed on the landfill prior to
construction of the landfill cap. A storm water management plan
would be prepared to design the grading plan, design the
retention and detention ponds, and determine the discharges for
storm water runoff. Lake Stupid would be drained and excavated to
eliminate human contact with the sediments, and to eliminate the
potential ecological exposure pathways. The water would be
treated and disposed of, and the sediments would be excavated and
placed on the landfill prior to construction of the landfill cap.
Excavation of Lake Stupid sediments shall continue horizontally
until the remaining sediment achieves the maximum contaminant
concentrations noted in section 9 below. Vertically, the
excavation shall continue to a depth of 24 inches, or until the
remedial goals have been met, whichever depth is less. The
excavated areas will be backfilled with clean soil. A vertical
barrier would be constructed between the landfill and Rock Pit
16
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Lake. The vertical barrier would prevent the migration of
contaminants to Rock Pit Lake from the landfill. It is expected
that the surface water of Rock Pit Lake would return to health
based levels through natural attenuation.
Residual ash and contaminated soils from the southern
portion of the site would be excavated and placed on the
landfill. Soil excavation shall continue horizontally until the
remaining soil achieves the maximum contaminant concentrations
noted in section 9 below. Vertically, the excavation shall
continue to a depth of 24 inches, or until the remedial goals
have been met, whichever depth is less. The. excavated areas will
be backfilled with clean soil.
Soils from the Liquid Disposal .Area located west of Lake
Stupid would be excavated. Soils from the drainfields on the
southern portion of the site would be excavated and placed on the
landfill. The buildings and structures on the southern portion of
the site would be decontaminated and/ or demolished, depending on
the planned use of the building locations and on the
practicability of decontaminating the buildings. The rubble and
debris from any demolished buildings and/ or process structures
which require demolition due to remediation or construction
considerations will be crushed and disposed of in the landfill.
This alternative would also include ground water monitoring,
surface water monitoring and monitoring of sediment and fish in
Rock Pit Lake for up to 30 years.
8.0 Comparative Analysis of Alternatives
The comparative analysis of the alternatives proposed for
the site are presented in this section. The alternatives are
evaluated against one another by using the following nine
criteria:
•Overall protection of human health and the environment.
•Compliance with Applicable or Relevant and Appropriate
Requirements (ARARs).
•Long term effectiveness and permanence.
•Reduction of toxicity, mobility, or volume through
treatment.
•Short term effectiveness.
•Implementability.
•Costs.
•State Acceptance.
•Community Acceptance.
The NCP categorizes the nine criteria into three groups:
(1) Threshold criteria: The first two criteria, overall
protection of human health and the environment, and
17
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compliance with ARARs (or invoking a waiver) , are the
minimum criteria that must be met in order for an
alternative to be eligible for selection.
(2) Primary balancing criteria: The next five criteria are
considered primary balancing criteria and are used to weigh
major trade-offs among alternative cleanup methods.
(3) Modifying criteria: State and community acceptance are
modifying criteria that are formally taken into account
after public comment is received on the proposed plan.
State and community acceptance are addressed in the
responsiveness summary of the ROD.
1. Overall Protection of Human Health and the Environment
With the exception of the no action alternative, all of the
alternatives would provide some degree of protection for human
health and the environment. However, Alternative 2 would not
eliminate the contaminant exposure pathways, and would rely on
engineering controls (such as fences, warning signs, etc.) to
minimize the possibility of direct contact with the contaminated
media. Alternative 3, while offering some degree of protection,
lacks a vertical barrier which would separate the landfill
contents from Rock Pit Lake and thereby prevent further erosion
of landfill material into the lake. Furthermore, alternative 3
would address residual ash above the clean up goals but would not
address the hot spots (contaminated soil, contaminated sediment,
etc.) on the southern portion of the site.
Alternatives 4 and 5 provide protection by eliminating the
potential routes of direct exposure to the contaminants,
primarily through excavation and capping. It is expected that
contaminant levels in surface water, fish tissue, and the
sediment in Rock Pit Lake would decrease over time since the
source material would be contained beneath the landfill cap.
However, as with all alternatives, the contents of the landfill
would remain in contact with ground water. Alternatives 4 and.5
would eliminate vertical infiltration above the water table, thus
providing the degree of protection practicable at this site given
that the source material will remain in contact with ground
water.
2.Compliance with ARARs
Alternatives 1 and 2 would not comply with act ion-specif ic
or chemical-specific ARARs. Subtitle D of the Resource
Conservation and Recovery Act (RCRA) requires closure of the
landfill with a cover of equivalent permeability to the
surrounding soil. The Florida Administrative Code (FAC) Chapter
18
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17-701 requires closure of Type I landfills with a multi-layer
cap including a gas collection layer, a drainage layer, and a low
permeability drainage layer. Storm water management is required
by FAC Chapter 17-725. Alternatives 1 and 2 would not decrease
levels of ground water contamination which currently exceed MCLs.
Alternative 3 could comply with RCRA subtitle D requirements
and the Alternate Procedures of the State landfill closure
requirements. Alternatives 4 and 5 would comply with Federal and
State action-specific and chemical-specific ARARs. Federal RCRA
Subtitle D and State Chapters 17-701, 17-702, and 17-725 action-
specific ARARs would be achieved under alternatives 4 and 5.
Achievement of risk based goals would also be achieved under
alternatives 4 and 5.
.3.Long-Term Effectiveness and Permanence
The soil cover in Alternative 3 would provide long term
reduction of risk by reducing the potential for exposure to the
landfill material. However, the soil cover would not be as
effective in the long term as the Alternative 4 and 5 landfill.
caps. Excavation and backfilling of Lake Stupid would reduce the.
potential for exposure to the lake sediments. Landfilling of the
incinerator ash residue would reduce' the potential for exposure
to this material. However, the soil cover would not provide for
long term protection of ground water because the permeable soil
cover would allow precipitation to continue to migrate through
the landfill.
Under alternatives 4 and 5, contamination would be further
reduced through removal of the source areas outside of the
landfill and control of the storm water and ground water
migration pathways. However, for each alternative, the contents
of the landfill would remain in contact with ground water. The
multi-layer cap would maintain its integrity with less
maintenance than a soil cover. The construction of a vertical
barrier between the landfill and Rock Pit Lake and control of
storm water would reduce the contaminant migration to Rock Pit
Lake, allowing for natural attenuation to reduce the
contamination in Rock Pit Lake to health based levels. Under
Alternative 5, the double liner cap would be expected to maintain
its integrity longer than a single liner cap without maintenance.
However, with proper maintenance and institutional controls that
would protect the integrity of the cap, both alternatives 4 and 5
should be equally protective.
4.Reduction of Toxicity. Mobility, arid Volume Through Treatment
Alternative 3 would reduce the toxicity and mobility of the
ash residue in the incinerator buildings and water treatment
19
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system structures by placing the material on the landfill prior
to construction of the soil cover. However, this alternative
would not reduce the toxicity of the landfilled material or Lake
Stupid sediments. Alternative 3 also would not reduce the
toxicity or mobility of the contaminated soils on the southern
portion of the. site.
Alternatives 4 and 5 would reduce the toxicity and mobility
of contaminants from the hot spots (contaminated soils,
sediments, and ash residue) by placing this material on the
landfill prior to construction of the landfill cap.
None of the alternatives employ treatment that reduce
toxicity, mobility, or volume as a principal element because: 1)
it would not be cost effective to treat the waste disposed of in
the landfill, 2) the selected remedy provides adequate protection
to the human health and the environment, 3) complies with the
Presumptive Remedy for CERCLA Municipal Landfill Sites approved
by OSWER Directive 9355.0-49FS for that portion of the Site
consisting of material already placed in the landfill and for the
material to be placed in the landfill and 4) the waste material
is not a RCRA hazardous waste.
OSWER Directive 9355.0-49FS establishes that the following
are the elements of a presumptive remedy for a municipal
landfill: 1) landfill cap, 2) source area groundwater control to
contain plume, 3) leachate collection and treatment, 4) landfill
gas collection and treatment, and/or 5) institutional controls to
supplement engineering controls. The remedy herein selected does
not include source area groundwater control to contain plume
because there is no known plume migrating from the Site. In
addition, the remedy does not include a leachate collection and
treatment system because the landfill material will remain in
place below the water table. In the event that groundwater
exceedences of Maximum Contaminant Levels (MCLs) are observed
beyond the current Site boundary, the groundwater portion of the
selected remedy will be reevaluated.
5.Short-Term Effectiveness
Alternatives 3, 4, and 5 each would present some potential
risks to remediation workers and the environment during
implementation. These risks would be controlled during remedial
action by restricting access in the construction area and
implementing a Health and Safety Plan. Additionally, the
community would be temporarily affected by the clearing and
grubbing of the landfill, exposure to fugitive dust during
clearing and grubbing, and increased traffic and noise. Dust
generation would be monitored and dust emissions would be
controlled during remediation. Under alternatives 4. and 5,
residents on the east side of the landfill may be impacted by
construction of the landfill cap, depending on how the cap is
20
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designed (the east toe of the landfill cap may encroach on
residential properties in this area). Protectiveness will be
achieved as soon as the contaminated soils, ash and sediments are
excavated, landfilled and a cap is constructed on the landfill
and as soon as Lake Stupid is drained and the water treated and
disposed of. Regarding Rock Pit Lake, protectiveness is expected
to be achieved through natural attenuation although an adequate
estimate of how long it will take to achieve protectiveness
cannot be established. However, Rock Pit Lake will be monitored
as established in Section 9.0 (Selected Remedy), Sub-section E
(Compliance Testing) and based on the results of the monitoring,
EPA, in consultation with FDEP, may reevaluate the remedy.
6.Implementabilitv
Under alternative 3, the soil cover construction, dewatering
and backfilling of Lake Stupid, and the decontamination and
sealing of the buildings and structures are technically feasible.
Services and materials are currently available to complete this
work. Under alternatives 4 and 5, construction of the landfill
caps, removal of hot spots, dewatering and dredging of Lake
Stupid, and the decontamination and/or demolition of the
buildings and structures can be implemented. Services and
materials are currently available to complete this work. These
alternatives would require compliance with storm water management
regulations. If the slope of the landfill along the east side of
the site encroaches on residential properties, it may be
necessary to relocate some residents and acquire their property.
However, this necessity will depend on, and may be eliminated by,
the details of the remedial design.
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7.Cost
A summary of the present worth costs (Capital and Operation
& Maintenance) for each of the alternatives is presented below.
Alternative
Alt. 1
Alt. 2
Alt. 3
Alt. 4
Alt. 5
Description
No Action
Restricted
Access
Soil Cover
Single
Barrier
Landfill Cap
Double
Barrier
Landfill Cap
Capital
Cost
In
Thousands
$0
$949
$12,361
$12,575
$19,675
O&M Cost
30 Years
In
Thousands
$91
$1,547
$3,696
$3,431
$3,431
Total -
Capital &
30 Yr O&M
In
Thousands
$91
$2,496
$16,057
$16,006
$23,106
Construction
Period
Not
Applicable
Not
Applicable
1 Year
2 Years
2 Years
8.State Acceptance
The State of Florida, as represented by the Florida Department of
Environmental Protection (FDEP), has been the support agency during
the Remedial Investigation and Feasibility Study for the Wingate Road
Municipal Incinerator and Landfill site. In accordance with 40 CFR
300.430, as the support agency, FDEP has provided EPA with input
during the process. Although FDEP has not indicated an objection to
the overall approach of the selected remedy, FDEP is unwilling to
concur with this ROD because FDEP disputes the remediation goals
selected for arsenic and dioxin in soil.
9.Community Acceptance
The concerns of the community are discussed in detail in the
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Responsiveness Summary, which is part of this ROD.
8.1 Synopsis of Comparative Analysis of Alternatives
All of the alternatives, except for Alternative 1 (No Action),
would provide some degree of overall protection of human health and
the environment. Alternatives 4 and 5 would comply with ARARs.
Alternative 4 represents the best balance among the criteria used to
evaluate remedies. Alternative 4 is believed to be protective of human
health and the environment, would comply with ARARs, would be cost
effective, and does not employ treatment that reduces toxicity,
mobility, or volume as a principal element because: 1) it would not be
cost effective to treat the-waste disposed of in the landfill, 2) the
selected remedy provides adequate protection to the human health and
the environment 3) complies with the Presumptive Remedy for CERCLA
Municipal Landfill Sites approved by OSWER Directive 9355.0-49FS) for
that portion of the Site consisting of material already placed in the
landfill and for the material to be placed in the landfill and 4) the
waste material is not a RCRA hazardous waste.
9.0 SELECTED REMEDY
Based upon consideration of the requirements of CERCLA, the NCP,
the detailed analysis of alternatives and public and state comments,
EPA has selected Alternative 4, Single Barrier Site Cap, as the remedy
for this site. At the completion of this remedy, the risk associated
with this site has been determined to be in the range from IxlO"4 to
IxlO"6 which is considered by EPA to be protective of human health and
the environment. The State of Florida prefers IE-6.
The total present worth cost of the selected remedy, Alternative
4, is estimated at $16,006,159. This includes capital costs of
$12,574,674. and present worth O&M costs of $3,431,485.
A. Source Control
A.I Major Components of Source Control
Source control will address the contaminated media at the site.
The primary component of the source control is the landfill cap.
Source control shall also include excavation of ash residue, soils,
and sediments, placement of the excavated material on the landfill,
and backfilling of the excavated areas with clean fill.
All surface soil and sediment on the southern portion of the site
which exceeds any of the remedial goals will be excavated and placed
on the landfill prior to construction of the landfill cap. Any
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residual ash or ash residue on the site (such as that located in the
buildings and structures, on the ground surface, in the soils, in Lake
Stupid, in the sediments and soils adjacent to Lake Stupid, in the
Lake Stupid drainage area, in the sludge bed and settling basins,
etc.) will be excavated to the levels of the performance standards
shown in Section 9.A.2 below. This material will be placed on the
landfill prior to construction of the landfill cap. The excavations
will be backfilled with clean fill.
The single barrier landfill cap will be designed to reduce human
and environmental contact with landfilled material, control erosion,
reduce infiltration and leachate production, and manage storm water in
accordance with state and federal standards. This site cap will be
designed to meet the requirements of Subtitle D of RCRA and Chapters
17-701 and 17-702 of the FAC. The cap will be designed with a gas
layer and drainage layers. The cap will be constructed of a low
permeability barrier layer, and a soil layer that includes topsoil or
soil to support vegetative cover. The remedial design will include an ,
investigation of the geotechnical characteristics for the site
material to support design of the cap. Design of the cap should
include consideration for future use of the property. Institutional
Controls may be required to assure the integrity of the cap.
The bushes and trees on the landfill will be cleared, grubbed,
and/or cut down. The cleared wood and vegetation debris will be
mulched, composted, and placed, on the landfill prior to construction
of the landfill cap. Debris from any demolished buildings and/ or
process structures which require demolition due to remediation or
construction considerations will be crushed and placed over the
cleared landfill area. Excavated soil will be placed over the building
debris on the landfill, and may be used to enhance grading, prior to
capping.
In accordance with Chapter 17-725 of the FAC, a storm water
management plan will be prepared to design the grading plan, determine
.the storm water flow rate from the cap, size the channels, and
determine the discharges for storm water runoff. Retention and/or
detention ponds will be designed around the landfill. A proposed site
plan for Alternative 4 is shown on Figure 3, however, placement of the
retention pond may be modified during the remedial design based on the
future use of the site and on the details of the design.
Grading and vegetation of the soil cover will be used to control
erosion. Geotextile fabric will be utilized for erosion control on the
landfill slope adjacent to Rock Pit Lake. A vertical barrier will be
constructed between the landfill and Rock Pit Lake to reduce migration
of hazardous substances, pollutants and contaminants from the landfill
to Rock Pit Lake. Once migration ceases, it is expected that the
levels of contaminants exceeding health based levels in the surface
water in Rock Pit Lake will decrease to these levels through natural
attenuation.
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J V.
MARTIN LUTHER KING JR. DLVO (NW 31st AVE.. FORMERLY WINCATE ROAD)
HnHm-
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.Lake Stupid will be drained and excavated to eliminate human
contact with the sediments, and to eliminate the potential ecological
exposure pathways. The water will be treated and disposed of, and the
sediments will be excavated and placed on the landfill prior to
construction of the landfill cap. The sediment may also be dried prior
to placement. The excavated area will be backfilled with clean soil.
The incinerator buildings and the buildings and structures
utilized for waste water treatment will be decontaminated. The method
of decontamination will be determined by the construction of the
building or structure. Typically, the residue/ash will be scraped from
the walls and floors and placed on the landfill prior to construction
of the cap to achieve the soil/ ash clean up goals.
All fencing and warning signs will be maintained, as well as the
site cap and storm water management system. The site will be
periodically inspected for vandalism. A maintenance and inspection
punch list will be developed and completed for submittal with the
inspection reports. The site will periodically be mowed and bushes and
trees trimmed.
Closure of the landfill under Alternative 4 may provide suitable
land area for future beneficial use of the property that will not
affect the integrity of the cap or other components of the remedy or
monitoring system. EPA encourages the responsible parties to consider
beneficial land uses during the remedial design. Some community
preferences for future land use are included in the Responsiveness
Summary.
A.2 Performance Standards
Soil excavation shall continue horizontally until the remaining
soil achieves the following maximum contaminant concentrations.
Vertically, the excavation shall continue4 to a depth of 24 inches, or
until the remedial goals have been met, whichever depth is less. The
excavated areas will be backfilled with clean soil. The following
remedial goals have been established for ash residue and surface soil:
Lead 500 mg/kg (ppm)
Arsenic . 23 mg/kg (ppm) *
Benzo(a)pyrene 0.13 mg/kg (ppm)
Beryllium 0.034 mg/kg (ppm)
Dioxin 0.0006 mg/kg (ppm) TEQ *
* EPA considers 23 ppm arsenic and 0.0006 ppm TEQ dioxin to be
protective of human health and the environment as these levels
fall within EPA's risk range. However, on September 29, 1995, FDEP
issued guidance suggesting a cleanup goal for arsenic of 0.7 ppm
which is more stringent than the selected remediation goal.
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Additionally, FDEP has stated a preference for 0.000006 ppm TEQ
dioxin which would meet a IE-6 risk, and which is more stringent
than the selected remediation goal. Attainment of the more
stringent levels may be necessary to obtain FDEP's concurrence
with deletion of this site from the National Priorities List in
the future.
Excavation of Lake Stupid sediments shall continue horizontally
until the remaining sediment achieves the following maximum
contaminant concentrations. Vertically, the excavation shall continue
to a depth of 24 inches, or until the remedial goals have been met,
whichever depth is less. The excavated areas will be backfilled with
clean soil. The following remedial goals have been established for
sediments. These levels are also established to evaluate the
effectiveness of the landfill closure on the sediments in Rock Pit
Lake:
Dioxin 0.0013 mg/kg (ppm) TEQ
Toxaphene 1.8 mg/kg (ppm)
Antimony 67 mg/kg (ppm)
Arsenic 46 mg/kg (ppm)
Cadmium - .170 mg/kg (ppm)
B. Ground Water Remediation
Section 300.430(f)(5)(iii)(A) of the NCP states that performance
shall be measured at appropriate locations in the ground water. EPA
has determined that remediation levels should be attained at and
beyond the edge of the waste management area when waste is left in
place. In accordance with the NCP and OSWER Directive 9283.1-2
"Guidance on Remedial Actions for Contaminated Ground Water at
Superfund Sites, December 19ff8", since the contaminated source
material will be left in place, this waste management area boundary
can be defined as the current (60-acre) site boundary.
The ground water component of the selected remedy requires no
remedial action within the current Site boundary other than ground
water use restrictions in the form of a deed notice. Therefore, ground
water inside the current Site boundary should not be used for potable
water supply. Based on available information, ground water outside the
current site boundary is protective of the human health and the
environment and requires no action at this time but will be monitored
in accordance with State FAC Chapters 17-701 and 17-702 landfill
closure requirements. Should exceedences of landfill closure ARARs or
ground water ARARs (including the performance standards in Section
9.B.I) be observed outside of the current site boundary; EPA, in
consultation with FDEP, will reevaluate the effectiveness of the
ground water component of the selected remedy.
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B.I Performance Standards
Site related ground water contamination which exceeds federal
and/or state ground water standards, including those listed in the
following table, will be evaluated. The following remedial goals have
been established for ground water outside the current Site boundary:
Bis(2-ethylhexyl)phthalate 6 ug/1 (ppb)
Benzene • 1 ug/1 (ppb)
Aluminum 50 ug/1 (ppb)
Antimony 6 ug/1 (ppb)
Cadmium 5 ug/1 (ppb)
Lead 15 ug/1 (ppb)
Manganese 50 ug/1 (ppb)
Mercury 2 ug/1 (ppb)
C. Surface Water Monitoring
Site related surface water contamination which exceeds Ambient
Water Quality Criteria (AWQC) will be evaluated to confirm the
effectiveness of the landfill closure in mitigating the surface water
migration pathway. The acute and chronic AWQC for lead (96/ 3.6 ppb),
aluminum (750/ 87 ppb), antimony (88/ 30 ppb), cadmium (3.9/ 1.1 ppb),
copper (19/ 13 ppb), silver (4.8/ 0.12 ppb), zinc (127/ 115 ppb), iron
(1000 ppb, chronic), mercury (2.4/ 0.012 ppb), and beryllium (0.13
ppb), shall apply to the site related surface waters.
p. Fish Tissue Monitoring
Site related fish tissue contamination in Rock Pit Lake which
exceeds remedial goals will be evaluated to confirm the effectiveness
of the landfill closure in mitigating this migration pathway. The
following remedial goal has been established for fish filet tissue in
Rock Pit Lake:
Dioxin 0.02 ng/kg (ppt, parts per trillion) TEQ
E. Compliance Testing
Ground water, surface water, sediment, and fish tissue monitoring
shall be conducted at this site for 30 years. The effectiveness of the
remedy will be reevaluated in consultation with FDEP, based on the
results of the monitoring. A zone of discharge may be established in
accordance with the state landfill closure regulations. Additional
monitoring wells will be necessary to monitor ground water outside of
the current Site boundary. The monitoring wells will be sampled and
the samples analyzed quarterly for the first two years for FAC Chapter
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17-701 parameters, as well as the site related contaminants noted in
Section B.I above. The monitoring frequency for the remaining years
will be determined based on the analytical results of the first two
years.
Sediment in Rock Pit Lake shall be monitored for the contaminants
noted in Section A.2 above. Surface water in Rock Pit Lake shall be
monitored for AWQCs for the contaminants noted in Section C above.
Sediment and surface water samples will be collected and the samples
analyzed quarterly for the first two years. The monitoring frequency
for the remaining years will be determined based on the analytical
results of the first two years.
Fish tissue in Rock Pit Lake will be monitored for dioxin and
lead concentrations. Fish samples will be collected and the samples
analyzed semi-annually for the first two years. Analysis will include •
whole-body analysis of a forage species and -filet analysis of a sport
species. The monitoring frequency for the remaining years will be
determined based on the analytical results of the first two years.
10.0 STATUTORY DETERMINATIONS
EPA has determined that the selected remedy is protective of
human health and the environment, complies with Federal and State
requirements that are legally applicable or relevant and appropriate
to the remedial action, and is cost effective. EPA has also
determined that this remedy utilizes permanent solutions but does not
satisfy the statutory preference for remedies that employ treatment
that reduce toxicity, mobility, or volume as a principal element
because: l) it would not be cost effective to treat the waste disposed
of in the landfill, 2) the selected remedy provides adequate
protection to the human health and the environment, 3) complies with
the applicable provisions of the Presumptive Remedy for CERCLA
Municipal Landfill Sites approved by OSWER Directive 9355.0-49FS for
.that portion of the Site consisting of material already placed in the
landfill and for the material to be placed in the landfill and 4) the
waste material is not a RCRA hazardous waste. However, the remedy
satisfies the bias against off-site land disposal of untreated wastes
to the extent practicable.
10.1 Protection of Human Health and The Environment
The selected remedy will protect human health and the environment
by reducing or preventing further migration of and exposure to
contaminants. The selected remedy should reduce the contaminant
concentrations in surface water, sediment, and fish tissue through
capping of the ash and soil contamination. The long-term cancer risk
posed by the ash and soil will be reduced to within EPA's acceptable
risk range of 1x10"* to ixlO"6 and the non carcinogenic risk would be
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reduced to the EPA goal of 1.
10.2 Compliance With ARARs
Implementation of this remedy will comply with State landfill
closure ARARs and will assure that Federal and State drinking water
standards outside the current site boundary are not exceeded.
As presented in section 9.A.I, the source control component of
the selected remedy includes in place closure of the landfill. The
landfill material is currently buried to approximately 30 feet below
the water table. To the extent technically practicable, capping the
source material will minimize leachate and contaminant migration above
the water table. However, horizontal flow of ground water through the
source material below the water table will continue, thus attainment
of ground water MCLs within the current site boundary is not
technically feasible.
Ground water outside of the current site boundary will be
monitored for compliance with the Federal and State ground water ARARs
including those identified in Section 9.B.I, as well as Sate landfill
closure ARARs.
Section 300.430 (f) (5) (iii) (A) of the NCP states that performance
shall be measured at appropriate locations in the ground water. EPA
has determined that remediation levels should be attained at and
beyond the edge of the waste management area when waste is left in
place. In accordance with the NCP and OSWER Directive 9283.1-2
"Guidance on Remedial Actions for Contaminated Ground Water at
Superfund Sites, December 1988", since the contaminated source
material will be left in place, this waste management area boundary
can be defined as the current (60-acre) site boundary.
The ground water component of the selected remedy requires no
remedial action within the current site boundary other than ground
water use restrictions to avoid drinking water wells from being
installed in this area. Therefore, ground water inside the current
site boundary should not be used for potable water supply. Ground
water outside the current Site boundary requires no action at this
time but will be monitored in accordance with State FAC Chapters 17-
701 and 17-702 landfill closure requirements. Should exceedences of
landfill closure ARARs or ground water ARARs (including the
performance standards in Section 9.B.I) be observed outside of the
current site boundary; EPA, in consultation with FDEP, will reevaluate
the effectiveness of the ground water component of the selected
remedy.
10.3 Cost Effectiveness
The selected remedy, Alternative 4, is a cost effective remedy.
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The total estimated present worth cost of this alternative is
$16,006,159 which includes capital costs and operation and maintenance
costs. EPA has determined that the cost of implementing the remedy is
appropriate given the threat posed by the site contaminants.
10.4 Use of Permanent Solutions and Treatment Technologies
The selected remedy utilizes permanent solutions but does not
satisfy the statutory preference for remedies that employ treatment
that reduce toxicity, mobility, or volume as a principal element
because: 1) it would not be cost effective to treat the waste disposed
of in the landfill, 2) the selected remedy provides adequate
protection to the human health and the environment, 3) complies with
the applicable provisions of the Presumptive Remedy for CERCLA
Municipal Landfill Sites approved by OSWER Directive 9355.0-49FS for
that portion of the Site consisting of material already placed in the
landfill and for the material to be placed in the landfill and 4) the
waste material is not a RCRA hazardous waste.
10.5 Preference for Treatment as a Principal Element
The selected remedy does not satisfy the preference for treatment
because: 1) it would not be cost effective to treat the waste disposed
of in the landfill, 2) the selected remedy provides adequate
protection to the human health and the environment, 3} complies with
the Presumptive Remedy for CERCLA Municipal Landfill Sites approved by
OSWER Directive 9355.0-49FS for that portion of the Site consisting of
material already placed in the landfill and for the material to be
placed in the landfill and 4) the waste material is not a RCRA
hazardous waste.
Because this remedy will result in hazardous substances,
pollutants and contaminants remaining on site above levels that allow
for unlimited use and unrestricted exposure, a review will be
conducted within five years after commencement of the remedial action
to ensure that the remedy continues to provide adequate protection of
human health and the environment. These reviews will be conducted
every five years or until remediation goals are achieved.
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES
Alternative 4 of the Feasibility Study envisioned additional work
to be performed in order to accommodate the storm water management
system on the southern portion of the site. This work would include :
* Excavating/ treating soils from the liquid disposal area located
east of the new incinerator building,
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* Excavating/ treating soils contaminated with petroleum in the
vehicle maintenance area,
* Excavating/ treating soils from drainfields associated with the
truck wash area, the old incinerator building, and the east drainfield
located east of the new incinerator building, and,
* Demolishing the incinerator buildings and water treatment system
structures after they have been decontaminated and placing the
demolition debris on the landfill prior to construction of the
landfill cap.
• Treatment of soils will not be necessary since samples of the
source material did not exceed the regulatory limits for TCLP metals,
as noted in Section 5.2.1 above, and since the soils are not a RCRA
listed hazardous waste. However, all soils in excess of the remedial
goals will be excavated and placed beneath the landfill cap to
eliminate the direct contact exposure pathway.
Additionally, the Feasibility Study envisioned that the area of
petroleum contamination in the vehicle maintenance area would be
remediated as part of the Remedial Action. However, CERCLA prevents
EPA from taking remedial action on petroleum contamination. Therefore,
the petroleum contaminated area must continue to be addressed through
FDEP and the Broward County Office of Natural Resource Protection
(ONRP) during the Remedial Design phase. If this area has not been
addressed by the City and ONRP prior to the completion of the Remedial
Design, EPA will proceed with the selected remedy for this site (i.e.;
the petroleum contaminated area will still need to be addressed
through ONRP). It should be noted that the selected remedy may include
construction in this area which may necessitate excavation for
construction of storm water management controls or other components of
the remedial action. In this event, the excavated soils will be
disposed of in the landfill prior to construction of the landfill cap.
The storm water management system design will be addressed in
detail in the remedial design. If building demolition is necessary in
order to accommodate adequate storm water controls, or in order to
achieve any of the remedial goals established in this Record Of
Decision, or because decontamination of the buildings/ structures is
not practicable; then such work may be carried out in accordance with
Alternative 4 of the Feasibility Study.
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RESPONSIVENESS SUMMARY
The U.S. Environmental Protection Agency (EPA) held a public
comment period from December 7, 1994 through January 6, 1995 for
interested parties to comment on EPA's Proposed Plan for the Wingate
Road Municipal Incinerator and Landfill Site (the site). EPA conducted
a public meeting at the Bass Park- Andrew De Graffenreidt Community
Recreation Center in Fort Lauderdale, Florida on December 12, 1994,
during the public comment period. During this meeting,
representatives of EPA presented the results of the site investigation
and EPA's preferred alternative for addressing the site related
contamination.
A summary of EPA's response to comments received during the
public comment period, known as the responsiveness summary, is
required under Section 117 of CERCLA. EPA has considered all the
significant comments made during the public comment period and answers
them in this responsiveness summary in determining the final selected
remedy presented in the Record of Decision.
This responsiveness summary consists of the following sections:
A. Background of Community Involvement and Concerns; this section
provides a brief history of community interest and concerns
regarding the site.
B. Summary of Significant Questions and Comments Received During
the Public Comment Period and EPA's Responses: This section
presents both oral and written (if any) comments submitted
during the public meeting and public comment period, and
provides the responses to these comments.
A. Background of Community Involvement and Concerns
In accordance with Sections 113 and 117 of CERCLA, EPA has
conducted community relations activities at the site to ensure that
the public remains informed of the continuing progress. During the
investigation, EPA has held meetings with state and local officials
and with the public to advise them of the progress at the site.
A community relations plan was developed to establish EPA's plan
for community participation during the investigation. Prior to the
initiation of the RI/FS, EPA held an Availability Session in Fort
Lauderdale to present the activities scheduled for the RI to the
public. Following completion of the RI field work, EPA held an
Availability Session to inform the public of the results of the RI.
Following completion of the FS, a Proposed Plan Fact Sheet was mailed
to local residents and public officials in December 1994. This fact
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sheet outlined EPA's preferred alternative for addressing the
contamination at the site. Additionally, the Administrative Record for
•the site, which contains site related documents including the RI and
FS reports and the Proposed Plan, was made available for public review
at the information repository at the Broward County main library in
Fort Lauderdale. Notices of the availability of the Administrative
Record for the site were published in the Westside Gazette Newspaper
on December 1st and 8th, 1994, and in the Broward Times Newspaper on
December 2nd and 9th, 1994.
A 30 day public comment period was held from December 7, 1994
through January 6, 1995 to solicit public input on EPA's preferred
remedial alternative: In addition to the comment period, EPA held a
public meeting at the Bass Park- Andrew De Graffenreidt Community
Recreation Center in Fort Lauderdale on December 12, 1994. The purpose
of this meeting was to discuss the remedial alternatives under
•consideration and to answer any questions concerning the Proposed Plan
for the Wingate Road site. The meeting was attended by approximately
50 area residents and public officials. Comments were received from
citizens of Fort Lauderdale, city officials, and the Florida
Department of Environmental Protection (FDEP). With the exception of
the cleanup levels for arsenic and dioxin in soils, FDEP has verbally
expressed agreement with the selected remedy.
EPA's response to the comments received at the meeting or during
the comment period are summarized in Section B below. A transcript of
the public meeting was prepared by a certified court reporter, and
this transcript is part of the Administrative Record upon which the
remedy selected in the Record of Decision is based.
Following the issuance of the final Record of Decision, EPA will
continue to keep the community informed about progress at the site
through fact sheets and informational meetings as needed.
Additionally, design and construction documents pertaining to the
implementation of the remedy will be placed in the information
repository at the Broward County main library.
B. Summary of Significant Questions and Comments Received During the
Public Comment Period and EPA's Responses.
1. Comment: Is it safe for people to eat fish from Rock Pit lake?
Response: Yes. Fish samples were collected and analyzed during the
investigation. The fish filet samples collected from Rock Pit Lake
contained a maximum dioxin concentration of 0.07 parts per trillion
(ppt) TEQ, which is below the level considered safe by ATSDR. If the
dioxin concentration had exceeded 25 ppt TEQ, then a fishing advisory
may have been called for. Additionally, EPA generated a site specific,
risk assessment based level of 0.02 ppt TEQ which would fall within
the acceptable risk range of 1E-4 to IE-6; 0.07 ppt also falls within
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this range.
2. Comment: Is there a correlation between the concentrations detected
and the ground water sampling locations? For instance, if ground water
was sampled close to Rock Pit Lake, was it more concentrated than
something two blocks away or three blocks away?
Response: The highest levels of ground water concentrations were found
in two places; one being in three wells located along the eastern edge
of the property, and the other being at the southern edge of the
landfill. Samples collected from off site private wells did not exceed
primary drinking water standards.
3. Comment: Is it safe to use Lake Stupid for recreational purposes?
Response: No. The sediment within and adjacent to Lake Stupid requires
remediation in order to mitigate future risk. Also, the water samples
collected from Lake Stupid exceed EPA's ambient water quality
criteria.
4. Comment: What is considered to be a normal level of contamination
in landfills? How can EPA compare the concentrations found ?
Response: There are no normal or set levels of contamination for
landfills. The concentrations are compared to the normally existing
background conditions in this area of Fort Lauderdale. Background
samples were collected from areas which would not have been impacted
by the site. Results from analysis of those samples are compared to
concentrations found on site to evaluate the site's impact relative to
naturally occurring background conditions.
5. Comment: Is the data presented in the Proposed Plan the total data?
Did EPA require TCLP testing?
Response: The proposed plan is a summary. There is more information
in the Remedial Investigation, but this is a summary of the conditions
at the site. The Remedial Investigation report can be found in the
Administrative Record in the information repository at the Broward
County main library. The administrative record contains the complete
data set. Toxicity Characteristic Leachate Procedure (TCLP) analysis
was performed on samples of the incinerator ash to determine whether
contaminants would leach from the ash. The samples passed the TCLP
test.
6. Comment: Can you determine after you do a risk assessment whether
or not there are certain types of cancers caused by certain chemicals
found at this type of site or maybe were produced by this site over a
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course of time?
Response: That is very difficult because one would have to look at an
individual's entire life history. One person in every four in the
United States gets cancer, whether they live near a hazardous waste
site or not. A lot of it has to do with lifestyle., genetics,
occupation, and some has to do with exposure, but we would have to be
able to pinpoint what each person was exposed to, and whether that
chemical causes a certain cancer or illness. EPA's risk assessment
predicts the potential for increased cancer risk to the general
population, not to specific individuals.
7. Comment: Due to the fact that City employees worked at the
incinerator, could the records of the health and well being of those
employees who worked at the site be gathered to find out what kind of .
health problems may have occurred in their lifetimes?
Response: That does not come under the jurisdiction of ATSDR or EPA.
There is a government agency that does look into that; the National
Institute of Occupational Safety and Health (NIOSH). Additionally, the
Florida Department of Health and Rehabilitative Services (HRS) may be
able to help with that. The commentor was informed to have former
employees at the facility make the request for a study directly to
either NIOSH or HRS. EPA has notified HRS of this concern.
8. Comment: Would the clean up alternatives potentially effect any of
the neighborhoods around the site?
Response: Yes. Alternatives four and five could potentially effect
three homes on the east side of the landfill. These homes could be
effected by construction of the landfill cap because they are so close
to the landfill. However, the effect, if any, will not be known until
the Remedial Design is done. The cap might be able to be designed in a
way that would not effect those properties.
9. Comment: Do local residents have to worry about the sediment from
the site potentially effecting them, in that could the wind blow it
off site and potentially hurt them?
Response: During clean up the contractors doing the work generally
take every precaution possible for dust suppression. Dust control
measures are used and air monitoring equipment is used to detect if
dust or contaminants are going into the community above a safe level.
These events are taken into consideration when preparing the Remedial
Design.
10. Comment: Is the site fenced?
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Response: Yes. However, both ATSDR and EPA have said on numerous
occasions that the gates at the site should be kept closed to minimize
contact with contaminated media.
11. Comment: Will there be a wall between the landfill and Rock Pit
Lake?
Response: Yes, under Alternatives four and five there would be an
impermeable barrier between the landfill and the lake.
12. Comment: Can we use the no action alternative?
Response: For this site, no. In this case, an action is necessary
since the site poses potential for risk due to long term exposure to
contaminated media.
13. Comment: Does the site pose a health threat to the community now?
Response: As long as there is no contact with contaminated material,
no. However, the threat at this site is associated with direct contact
with and incidental ingestion of contaminated media under current and
future land use scenarios.
14. Comment: Why can't we use Alternative 5 instead of Alternative 4?
Response: Although Alternative 5 has an added feature (an extra
liner), both alternatives 4 and 5 are protective of human health and
the environment. The cap included in the design for Alternative 4
would contain all of the contaminants from the southern portion of the
site and from the landfill itself. And, EPA will perform a Five-Year-
Review once every five years,'including a'physical check of the cap
and the ground water monitoring system, and all other components of
the Remedial Action to make sure it remains protective. Based on the
protectiveness of Alternative 4, EPA determined that it was not cost
effective to add an additional liner, which was included in
alternative 5, at a cost of approximately $7 million more.
15. Comment: Can you calculate past contaminant concentrations or risk
levels?
Response: No. We can calculate current and future risk, but we can not
go back in time and calculate past levels of risk. ATSDR can look into
probable past exposure, but not levels of contamination or risk.
16. Comment: Several commentors asked what beneficial use the site
might be put to following the remedial action. They mentioned ideas
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such as a golf course, a cultural arts center, a theatre, and a nature
area.
Response: Given that the site is in a residential area, EPA agrees
that future land use that will not adversely affect the integrity of
the selected remedy should be considered. The future use of the site
will ultimately depend on how the city decides to use the property.
Under CERCLA, EPA can only require that threats to human health and
the environment be addressed. It is not known at this time whether the
examples noted above would be practicable. However, EPA will encourage
the responsible parties to consider and plan for future beneficial use
of the property during the remedial design phase.
17. Comment: FDEP expressed concern with the arsenic cleanup level of
23 parts per million (ppm) in soil and the dioxin cleanup level of
0.0006 ppm TEQ in soil. FDEP has stated a preference for 0.56 ppm or
background, whichever is greater, for arsenic; and 0.000006 ppm TEQ
for dioxin which would meet a IE-6 risk.
Response: EPA's remediation goals of 23 ppm arsenic and 0.0006 ppm
dioxin in soil yield a risk within the acceptable risk range as
defined by 40 CFR 300.430(e)(2). EPA is aware of FDEP's guidance
concerning 0.7 ppm arsenic for soil dated September 29, 1995, and
FDEP's stated preference concerning 0.000006 ppm dioxin for soil.
However, these levels are not considered to be Applicable or Relevant
and Appropriate Standards (ARARs) as defined in 40 CFR 300.400 because
they have not been promulgated by the State.
EPA is aware of FDEP's long standing preference for attaining risk no
greater than 1E-6 for carcinogens. However, the Superfund provides EPA
with flexibility in developing remediation goals which attain risk
between 1E-4 and 1E-6. Use of a risk range is a necessary tool for the
risk management process to account for factors such as toxicological
uncertainty and/or confidence. FDEP's preference was also factored
into the risk management process prior to establishing the remediation
goals.
EPA acknowledges FDEP's preferred cleanup goals and the potential need
to attain these goals for NPL deletion of the site in the future.
Although lower cleanup levels are not necessary to meet EPA's selected
remediation goals at this site, the State may independently pursue an
agreement with the PRPs to address the lower goals. A negotiated
agreement between the PRPs and FDEP could be incorporated into the
design and implementation of EPA's selected remedy.
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