Superfund Record of Decision: Florida Steel, FL


           United States        Office of
           Environmental Protection   Emergency and
           Agency           Remedial Response
EPA/ROD/R04-92/122
June 1992
&EPA   Superfund
          Record of Decision:
           Florida Steel, FL

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                                         NOTICE

The appendices listed in the index that are not found in this document have been removed at the request of
the issuing agency. They contain material which supplement, but adds no further applicable information to
the content of the document All supplemental material is, however, contained In the administrative record
for this site.

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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R04-92/122
3. Redpianr* Accession No.
4. TMa and Subtitle
SUPERFUND RECORD OF .DECISION
Florida Steel, FL
First Remedial Action - Subsequent to follow
B. Report DM*
06/30/92
7. Authors)
8. Performing Organization Rapt No.
9. Performing Organization Name and Address
10. ProJect/Task/Work Ural No.
11. Contract* C) or Gram
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EPA/ROD/R04-92/122
Florida Steel, FL
First Remedial Action - Subsequent to follow

Abstract (Continued)

disposal. In 1983, state investigations revealed PCB contamination of soil in the area
of a recirculating reservoir and in the EC disposal areas. In 1985, the state required
FSC to remove approximately 8,000 tons of EC dust from the disposal areas and send it to
an offsite recycling facility for zinc recovery. A second removal action, conducted in
1986, involved excavating 11,200 cubic yards of contaminated soil, sediment, and EC dust
containing PCBs greater than 50 mg/kg and temporarily storing the materials in an onsite
storage vault, as well as implementing an onsite ground water monitoring program. The
stored PCB-contaminated soil was later incinerated onsite under a consent order with EPA
in 1987, and ash from this incineration was consolidated within the ash retention
building pending final deposition. This ROD addresses the remaining contaminated onsite
soil, sediment, and debris as OU1. The primary contaminants of concern affecting the
soil, sediment and debris are organics, including PCBs; and metals, including lead.

The selected remedial action for this site includes excavating and disposing offsite
600 cubic yards of soil and sediment contaminated with PCB levels equal to or greater
than 50 mg/kg; excavating and onsite solidification of 37,000 cubic yards of EC dust and
metals-contaminated ash and soil, including soil with lead concentrations above 600 mg/kg
and/or PCB concentrations between 25 and 50 mg/kg; temporarily storing the excavated
materials onsite pending final
treatment in a manner that will prevent PCB contamination through surface water run-off,
and disposing of the solidified materials in an onsite double-lined landfill with a RCRA
cap; controlling surface water run-off from the site by routing it to the onsite surface
water retention pond; periodic monitoring of surface water for at least 2 years after
construction is completed; continuing ground water quality monitoring; and implementing
institutional controls, including deed restrictions. The estimated present worth cost
for this remedial action is $7,004,750, which includes an annual O&M cost of $18,200 for
30 years.

PERFORMANCE STANDARDS OR GOALS:

Chemical-specific soil excavation goals are based on health risk levels and the
leachability of lead from soil into the underlying ground water, including lead in soil
600 mg/kg; PCBs 25 mg/kg; and slag, which contains lead 1360 mg/kg. The slag level was
developed to be protective of human health in an industrial setting, and additional TCLP
testing will be conducted during the RD stage to confirm its protectiveness. Compliance
with the RCRA land disposal treatment standards for EC dust will be attained by meeting
levels specified in the treatability variance for contaminated soil and debris.
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RECORD OF DECISION
THE DECLARATION
SITE NAME AND LOCATION
Florida Steel Corporation
Indiantown, Martin County, Florida

STATEMENT OF BASIS AND PURPOSE

This decision document presents the selected remedial action for
the site noted above. The remedy was 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), and to the
extent practicable, the National Contingency Plan (NCP). This
decision is based on the administrative record for this site.

The State of Florida has concurred with this Record of Decision.

ASSESSMENT OF THE SITE

Actual or threatened releases of hazardous substances from this-
site, if not addressed by implementing the response action selected
in this Record of Decision (ROD), may present an imminent and
substantial endangerment to public health, welfare, or the
environment.

DESCRIPTION OF THE SBT.RCT'iqD REMEDY

This response action represents the first of two planned operable
units at the site. However, several actions were taken prior to
this first operable unit. The first action was the removal of
emission control (EC) dust piles from the site during 1985 with the
approval of the Florida Department of Environmental Regulation
(FDER). The second action, in 1986, was the excavation and on-site
storage of soil contaminated with polychlorinated biphenyls (PCBs)
as described in a consent agreement between Florida Steel
Corporation (FSC) and FDER. In 1987, the PCB contaminated soil was
incinerated in accordance with a consent order between FSC and the
U.S. Environmental Protection Agency (EPA).

This remedy addresses the remaining source, incinerator ash, soil
and sediment contamination at the site. This remedy addresses the
principal threat at the site by excavating and treating the EC dust
and the most highly contaminated soils. The second planned
operable unit at this site will address contamination in off-site
wetlands and contaminated groundwater.

The major components of the remedy for this first operable unit
include:

•Excavation and off-site disposal at an EPA approved facility of
approximately 600 cubic yards of soil contaminated with PCB levels
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equal to or greater than 50 ppm.

•Excavation and on-site solidification of approximately 37,000
cubic yards of the following:
-EC dust and metals contaminated soil and ash. All EC dust
and ash would be excavated and treated; soil containing lead
above 600 ppm would be excavated and treated.
-soil containing PCB levels between 25 and 50 ppm;

No excavation will take place below the water table. Current
knowledge of contaminant distribution at the Site would indicate
that no excavation below the water table will be required.

•Control of surface water runoff from the site during remediation
of on-site soils. *

•Compliance with Resource Conservation and Recovery Act (RCRA) Land
Disposal Restriction treatment standards for EC dust, which is the
listed RCRA waste K061, by meeting levels specified in the
treatability variance for contaminated soil and debris.

•Disposal, in an on-site double lined RCRA landfill with a RCRA
cap, of all solidified material. The landfill would meet the
provisions of 40 C.F.R. Subpart N landfill requirements and would
be built above the water table.

•Periodic monitoring of surface water and groundwater quality. The
quality of surface water runoff should be consistent with possible
future criteria developed for the adjacent wetlands in the second
operable unit for this site. Groundwater quality would be
monitored for up to 30 years.

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 satisfies the statutory
preference for remedies that employ treatment for the reduction of
toxicity, mobility, or volume, as a principal element and utilizes
permanent solutions and alternative treatment technologies to the
maximum extent practicable for this site.

Because the remedy will result in hazardous substances remaining
on-site, a review will be conducted within five years after
commencement of remedial action to ensure that the remedy continues
to provide adequate protection of human health and the environment.
Date A) Greer C. Tidwell
' Regional Administrator
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TABLE OF.CONTENTS

SECTION TITLE PAGE

1.0 Site Background 1
2 .0 Site History and Enforcement Activities 1
3 .0 History of Community Relations 9
4 . 0 Scope and Role of Action 9
5.0 Summary of Site Characteristics 10
5 .1 Site Geology 10
5.2 Hydrology 16
5. 3 Soil contamination 18
5 .4 Groundwater Contamination .21
5.5 Surface Water Contamination 23
5.6 Potential Routes of Contaminant Migration....24
6 .0 Summary of Site Risks 24
6.1 Identification of Contaminants of Concern....24
6 .2 Exposure Assessment Summary 25
6 .3 Toxicity Assessment 27
6.4 Summary of Baseline Risk 28
6 . 5 Environmental Risk 34
6 . 6 Risk Uncertainty 34
6 .7 Risk Conclusions 35
7 .0 Summary of Alternatives 35
PCB Contaminated Soil 35
EC Dust and Metal Contaminated Material 36
8 .0 Comparative Analysis of Alternatives 39
Overall Protection 40
Compliance with ARARs 40
Long term effectiveness and permanence 40
Reduction of toxicity, mobility, or volume
through treatment 41
Short term effectiveness 41
Implement ability 41
Costs 42
State Acceptance 42
Community Acceptance 42
9 .0 Selected Remedy 42
9.1 Remediation Goals 44
10.0 Statutory Determinations 45
10.1 Protection of Human Health
and the Environment 45
10.2 Compliance with ARARs 45
10. 3 Cost effectiveness 47
10.4 Utilization of Permanent Solutions
or alternative treatment technologies
to the maximum extent practicable 47
10.5 Preference for treatment 48
11.0 Explanation of Significant Changes 48
References 49

APPENDIX A: Administrative Record Index
APPENDIX B: Responsiveness Summary
APPENDIX C: Risk Calculation Constants
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TABLES

Number Title. Page

1 Contaminant Concentrations in EC dust and
soil 21
2 Contaminant Concentrations in groundwater 23
3 Air Sampling Results 26
4 Summary of Baseline Risks 30-33
5 Treatment Levels for EC dust 38
FIGURES

Number Title Page

1 General Location Map 2
2 Site Location Map 3
3 Site Layout 5
4 Phase I Soil Sampling Locations 7
5 Phase II Soil Sampling Locations 8
6 Geologic Cross Section A-A' 12
7 Geologic Cross Section B-B' 13
8 Groundwater elevation Map 14
9 Surface Water Flow 17
10 PCB Concentration Map 19
11 Lead Concentration Map 20
12 Location of Groundwater Monitoring Wells 22
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RECORD OF DECISION
THE DECISION SUMMARY
FLORIDA STEEL CORPORATION
INDIANTOWN, FLORIDA

1.0 SITE NAME. LOCATION. DESCRIPTION

The Florida Steel Corporation (FSC) Site is located on Highway
710 approximately two miles northwest of Indiantown, Florida.
The Site is approximately two miles northeast of the St. Lucie
Canal and is located within the Indian River Lagoon Drainage
Basin System. The Site covers approximately 150 acres and is
bounded on the north by the Seaboard Coast Line (CSX) railroad
and State Highway 710 (see Figures 1 and 2). Beyond the highway,
for several miles to the north/ there is only unimproved land.
The adjacent property is a mixture of uplands and wetlands, with
little overall variation in elevation.

Indiantown is a small community in Martin County. It is located
on State Highway 710, near the St. Lucie Canal, about 25 miles
west of Stuart, the county seat, and 40 miles northwest of the
city of West Palm Beach. The Indiantown population of about
5,000 is mostly employed in the nearby citrus farms and in local
commerce. A large area west of Indiantown and surrounding the
FSC steel mill site is zoned industrial.

The nearest downgradient residence is about one-half mile south
of the FSC property, and is a single family private dwelling.
There are several other dwellings located within one mile
downgradient of the site.

2. SITE HISTORY AND ENFORCEMENT ACTIVITIES

The Indiantown site was acquired by FSC in 1969 for the purpose
of constructing a steel mill using electric arc furnace
technology for recycling scrap steel, primarily junk automobiles,
into new steel products including concrete reinforcing steel and
round and square merchant bar.

The Indiantown steel mill operated from November 1970 until
February, 1982, when, because of the prevailing depressed
economic conditions, FSC decided to temporarily cease production
at the facility. The mill has not been operated since that time
and the company has no present plans for its reopening.

Three types of byproducts were produced at the Indiantown Mill.
These were mill scale, slag, and emission control (EC) dust.
Mill scale is the oxidized iron that sloughs off the hot steel as
it is being cooled with water sprays. It accounts for roughly 2
percent of the steel produced and has the same composition as the
steel.

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State of Florida
Martin
County
Figure 1: General Location Map
Florida Steel Corporation
Martin County
Indiantown, Florida
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200O
SITE LOCATION MAP
SECTION 35
TOWNSHIP 39, SOUTH
RANGE 38, EAST
SCALE FEET
MTAIKED F1CT U5g QUM HM- OKEEOOKE 4 SE. FIOK1M (WOTOttVISED W83)
ArdMiMflA
Inc.
FLOfOOA tTEEL COflPQKATKM
INOIANTOWN
mOUNTOWN,
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Slag is formed on top of the steel in electric arc furnaces. It
is formed from lime, which is introduced as a flux into the
furnace to remove impurities such as soil and sand from the
molten steel. Total primary metals present in slag are barium,
chromium and lead. At Indian town, the slag was crushed and
graded and sold.as aggregate and fill material.

EC dust is the fine particulate material generated as the high
temperatures (greater than 3000 degrees F.) in an electric arc
furnace drive off and oxidize some of the iron and most of the
other volatile metals contained in the scrap. Roughly 25 to 30
Ibs of EC dust are generated for every ton of steel produced.
Typically at the Site, the major constituents in EC dust, in
order of decreasing concentrations, are iron oxide, zinc oxide,
and lead oxide.

During the lifetime of the plant, from November 1970 to February
1982, the EC dust was collected by a system of baghouses. Until
November 17, 1980, the dusts captured in the baghouses were
deposited in two on-site disposal areas (area B on Figure 3).
After November 18, 1980, EC dust was regulated as an EPA-listed
hazardous waste (KO61). Between November 18, 1980, and February
1982 the EC dust generated at Indian town was shipped of f-site
under RCRA manifest.

In December 1982, the FSC Indian town Hill property was included
on the National Priority List (NPL) under the provisions of
CERCLA. The listing was based on the potential threat to the
environment from the heavy metals present in the EC dust and the
shallow water table. Early in 1983, FSC met with the FDER
District Office and commenced the first phase of the site
investigation, focusing on the EC dust disposal areas.

In March 1983 it was discovered that some of the soils in the
vicinity of the concrete recirculating reservoir (CRR) and a
small portion of the area containing the EC dust were
contaminated with PCBS. The PCB contamination has been
attributed to the use, in the early 1970s, of hydraulic fluid
containing PCBs.

During 1985, FSC removed approximately 8000 tons of EC dust from
both of the EC dust disposal areas and shipped it under manifest
to a metal recycling facility for zinc recovery. Some EC dust
was also removed as part of the PCB cleanup. However, EC dust is
still present in the former disposal areas.

In compliance with the Consent Agreement between FSC and FDER
dated September 4, 1985, approximately 11,200 cubic yards (18,800
tons) of soil, sediment and EC dust containing PCBs at a
concentration of 50 ppm and above were excavated from the site
between February 15, 1986 and May 8, 1986, and temporarily placed
in a specially constructed secure on-site storage vault. The

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Fioure 3: Site Layout
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excavations were then backfilled with clean fill material..

Also in 1986, Florida Steel began a periodic groundwater
monitoring program at the site.

In October 1986, Florida Steel developed a separate Feasibility
Study that described options for the treatment of the PCS
contaminated soil in the vault. In 1987, based on this
feasibility study, Florida Steel was directed to incinerate the
PCB contaminated soil.

In compliance with the Administrative Order on Consent between
FSC and EPA dated September 21, 1987, incineration of the
material in the vault began during October 1987 and was completed
in May 1988.

Because of the presence of heavy metals, ash from the
incineration was consolidated within the ash retention building
pending final disposition. Final disposition of the ash is
addressed by the ROD.

FSC received a Special Notice Letter from EPA dated May 22, 1987
requesting that FSC conduct the Remedial Investigation/
Feasibility Study (RI/FS). The letter also stated that if FSC
declined, then EPA would conduct the RI/FS and seek to recover
its costs. FSC was the only party to receive a notice letter. A
title search confirmed that Florida Steel was the only owner at
the site.

FSC ultimately agreed to conduct the RI/FS. The State of Florida
requested the enforcement lead for the project and an Order on
Consent between FDER and FSC was signed September 22, 1987 (OGC
#84-0150).

In 1988, FDER directed Florida Steel to conduct a RI at the site.
The RI was conducted in two phases. During Phase I, soil and
groundwater samples were collected from the most frequently used
areas of the site. These samples were analyzed for the full
range of hazardous substances. Metals such as cadmium, chromium,
iron, lead, zinc were found in the samples. Figure 4 shows the
location of the Phase I sampling points.

Phase II of the RI included additional sampling to further define
the extent of EC dust and to determine if PCBs were present in
areas outside those previously addressed. Soil samples were
collected from across the entire site and analyzed for PCBs and
the metals that were most commonly found during Phase I. Figure
5 shows the Phase II sampling locations.

A Baseline Risk Assessment for the Indiantown site was submitted
by Envirologic Data, Inc. The Baseline Risk Assessment evaluated
the current and potential risks posed by the contamination at the

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LEGEND

01 • DENOTES SOIL SAMPLING LOCATION

P1COMPKC2 DENOTES SOIL SAMPLES

P1SED * SEDIMENT SAMPLING POINT
PHASE I
SOIL AND SEDIMENT
SAMPLING LOCATIONS
la* It/fi/ir
Figure 4
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LOCATION OP
MUM! 80H. SAMMJI8
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site under the no-action scenario for current future uses of the
site.

The Feasibility Study (FS) was prepared after completion of the
RI and Risk Assessment. The FS evaluated a range of remedial
alternatives that would permanently reduce the volume, toxicity,
and/or mobility of any contaminants of concern remaining at the
site.

3.0 HISTORY OF COMMUNITY RELATIONS

The RI/FS report and the Proposed Plan for the Site were released
to the public for comment on April 27, 1992. These two documents
were made available to the public in both the administrative
record and an information repository maintained at the EPA Docket
Room in Region IV and at the Indiantown Public Library (see
Appendix A for an index of the administrative record).

The notice of availability for these two documents was published
in the Stuart News on April 20, 1992 and in the Indiantown News
on April 22, 1992. The notice also advertised the upcoming
public meeting and the availability of site documents at the
Indiantown Public Library. The public comment period on the
documents was held from April 27, 1992 until May 27, 1992.

Over 600 fact sheets summarizing the proposed plan, advertising
the upcoming public meeting, and noting the availability of site
documents at the Indiantown Public Library were mailed on April
20.

A public meeting was held on April 30, 1992. At this meeting,
representatives from EPA and FDER answered questions about site
conditions and the remedial alternatives under consideration. A
response to the comments received during this meeting and the
comment period is included in the Responsiveness summary, which
is part of this ROD (see Appendix B).

4.0 SCOPE ANP nnr.B pp ACTION;

As with many Superfund sites, the problems at the Florida Steel
Corporation Site are complex. As a result, EPA has organized the
remedial work into two operable units: 1) soil and 2) groundwater
and wetlands. This ROD addresses operable unit one - soil at the
Site.

The most immediate threats at the site have already been reduced
through the removal of EC dust and the incineration of PCB
contaminated soil. Remedial actions described for operable unit
one will address the residual amounts of EC dust and PCB
contaminated soil that remain on-site; the interrelationship
between the soil contaminant levels and groundwater protection
will be discussed.

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Cleanup alternatives are being evaluated for contaminated
groundwater and contaminated wetland areas located adjacent to
the site. However, additional information is needed before a
final decision can be made about the need for and type of cleanup
alternatives for both of these media. A decision regarding the
groundwater and.wetlands will be made later under a second
operable unit for this Site after the public comment period has
concluded.

5.0 SUMMARY OF SITE CHARACTERISTICS

5.1 Site Geology

The Atlantic Coastal Ridge in Martin County parallels the present
coastline and varies in width from about three miles in the
southeast corner of the county to about six miles in the central
coastal area, and to about four miles in the northern area.

The Eastern Flatlands occupy the area from the Atlantic Coastal
Ridge westward to the Everglades and Lake Okeechobee. This is a
monotonously flat region with the exception of two elongated
ridges known as Orlando Ridge and Green Ridge. Both ridges trend
northwest. Green Ridge is in the center of the county and
Orlando Ridge in the western half. The Indiantown steel mill is
located on the southwestern flank of the Orlando Ridge. The
altitude of the Orlando Ridge in Martin County ranges from about
30 to 50 feet above mean sea level, the highest altitude being
near the southern part of the ridge. The altitude of Green Ridge
is Ibwer than that of Orlando Ridge, ranging from 30 to 35 feet
above mean sea level. The altitude of the land surface in the
remainder of the Eastern Flatlands generally ranges from slightly
less than 20 feet above mean sea level to 30 feet above mean sea
level.

In the area north of the St. Lucie Canal, the Eastern Flatlands
rise gradually from the valley of the St. Lucie River to Green
Ridge. West of Green Ridge the land surface is extremely flat,
having an average altitude of 28 feet above mean sea level and a
very slight slope to the south. West of the Orlando Ridge the
Eastern Flatlands slope gently to the Everglades and the shore of
Lake Okeechobee.

There are two major aquifers in Martin County; the shallow
(non-artesian) aquifer, from 15 to 150 feet below the land
surface, and the Floridan (artesian) aquifer, 600 to 1,500 feet
below the land surface. The two aquifers are separated by a
thick section of sand and clay of low permeability.

The shallow aquifer is the principal source of fresh water
supplies in Martin county. It includes the Pamlico sand, the
Anastasia formation and possibly the Caloosahatchee marl with the
Anastasia formation probably being the principal source of

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groundwater. The shallow aquifer extends from the water table to
about 150 feet below the land surface. It is composed
principally of sand, but also contains relatively thin beds or
lenses of limestone, sandstone, or shell, which are generally
more permeable than the sand. Most large-capacity wells are
developed in the limestone, sandstone, or shell.

Some fairly large supplies of water and many small water supplies
are obtained from the sand by the use of sandpoints, well
screens, and open-ended wells.

The lithology of the aquifer changes laterally as well as
vertically, so that the permeable beds are not always found at
the same depth; in fact, in some areas they are missing entirely.
The permeable limestone, sandstone, and shell strata are more
prevalent in the eastern part of the county than in the western
part.

The lithology of the upper portion of the shallow aquifer at the
site is shown on the geologic cross-sections on Figures 6 and 7.
The locations of the cross-section lines are shown on the
figures. The cross-sections indicate consistent geology with
fine to coarse sand from land surface to approximately 10 feet,
organic-rich sand or hardpan to 15 feet, very fine to fine
tan-white sand to 30 feet and gray-green silt to 40 feet. From
40 to 120 feet, the lithology consists of very fine to coarse
gray sand in 5- to 10-foot layers, some of which are shell-rich
and/or silty.

In the Indiantown area, small diameter open-end wells can be
constructed immediately below the hardpan, in permeable sand from
25 to 35 feet below the land surface. Open-end wells can also be
developed in shell beds from 95 to 110 feet below the land
surface to yield moderate amounts of potable water.

Most of the sand of the Eastern Flatlands area is of low to
medium permeability, but sandpoint wells will yield enough water
for most domestic needs. Most sandpoint wells are 15 to 45 feet
deep and 1.25 to 2 inches in diameter. The nearest wells of such
shallow depth are located approximately 1/2 mile south
(downgradient) of the FSC Indiantown Mill. The higher capacity
wells in the Indiantown area, including the FSC production well
are screened from about 100 to 125 feet. The water supply wells
for the community of Indiantown, located over two miles southeast
of the mill, are also screened in the 100 to 125 foot depth
interval.

The water table is an undulating surface conforming in a general
way to the topography of the land. Most of Martin County west of
the coastal ridge is relatively flat and the water table is close
to the land surface.
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CRAY S1M>. VERT FINE TO COARSE
IN SFT. TO 10 FT. LAYERS.
SOME SHELL-RICH a SILTV
rflORMO OR
I MOWTDRINO WELL
J00«00
i •GHw.n AMoctttn
QCOUXHC
CUOSS-SHmONA-A
Figure 6
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ORAT SAND. VERT FINE TO COARSE
M S FT. TO 10 FT. LAYERS,
SOME SHELL-RICH a SILTV
GEOLOGIC .
CROSS-SECTION B-B'
Figure 7
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\
-ysrss
..-'Taw
M MTERMEDMTE DEPTH
MONTTOfONQ WELLS ON
MAY 11, 19»»
Figure 8
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Groundwater elevation maps for the shallow aquifer prepared by
Earle (1975), confirm the findings of the site investigation,
namely that the direction of groundwater flow at the Site is
towards the south. The maps prepared by Earle also show that the
St. Lucie Canal represents a divide for the shallow aquifer with
groundwater flowing toward the canal from both the north and
south. A groundwater elevation map for the site is presented in
Figure 8. Subsurface drainage is very sluggish owing to the
flatness of the terrain.

The shallow aquifer in Martin County receives most of its
recharge from rainfall in and immediately adjacent to the county.
Most of the county is covered with sand that is sufficiently
permeable to absorb practically all 60 inches of annual rainfall.
In general, surface water runoff accounts for a minor fraction of
the annual precipitation until the water table reaches the ground
surface.

Groundwater is discharged by flow into streams, ditches or
canals, by direct flow into the ocean, by evapotranspiration, and
by pumping from wells. In the central part of the county, where
the water table is at or near the surface during most of the
year, evapotranspiration is the most important means of
discharge.

Groundwater levels decline from about 2 to 5 feet during the dry
season in most areas of the county. Seasonal fluctuations
observed in monitoring wells at the FSC Indiantown Mill are in
this range with the water table generally within 5 feet of land
surface.

The artesian aquifer in Martin County is part of the Floridan
aquifer, which underlies all of Florida and southern Georgia.
Permeable parts of the Avon Park limestone and the Ocala Group
comprise the principal producing zones of the Floridan aquifer.

In all parts of Martin County, except at the tops of the high
sandhills in the eastern part of the county where the land
surface is more than 50 feet above mean sea level, wells
penetrating the Floridan aquifer will flow. The top of the
Floridan aquifer in Martin County is usually between 600 and 800
feet below the land surface. The thickness of the aquifer is
unknown, as no wells have completely penetrated it. The deepest
known wells extend 1,300 to 1,500 feet below mean sea level.

The potentiometric surface for the Floridan aquifer in Martin
County ranges from 49 to 53 feet above mean sea level. The
potentiometric surface generally slopes in an east-southeasterly
direction in Martin County; however, local cones of depression
caused by relatively large withdrawals can distort the regional
pattern.

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The piezometric surface is higher than the water table in.all
parts of Martin County. For this reason, recharge to the.
Floridan aquifer does not occur in Martin County. Discharge by
upward leakage through the confining beds of the Hawthorn
formation is probably small in Martin County. The confining bed
is composed of more than 500 feet of fine sand, silt and "tough"
green clay of extremely low permeability.

Groundwater from the artesian aquifer in the vicinity of
Indiantown is somewhat brackish with chloride and total dissolved
solids concentrations on the order of 500 to 1,000 mg/1,
respectively.

5.2 Hydrology

The surficial sands throughout most of central Martin county are
sufficiently permeable to absorb pre ically all 60 inches of
annual rainfall; consequently, drai- a is chiefly underground.
Due to the flatness of the terrain, ads form throughout most of
the. region during the rainy season. surface water flow from the
site is intermittent, occurring oniv during the rainy season.
The direction of surface water flow is shown on Figure 9.

The St. Lucie Canal, which is approximately two miles southwest
of site at its closest point, is the major channel used for
control of water levels in Lake Okeechobee. The canal originates
on the east shore of the lake and flows generally northeastward
for about 40 miles to the Atlantic Ocean. The upper reaches
constitute an engineered canal but the lower channel follows the
canalized course of the South Fork of the St. Lucie River.

Indiantown and a large part of Martin County lies within the
Indian River Lagoon Drainage Basin. Surface water in the
Indiantown area can flow into the channelized St. Lucie Canal
which flows into the St. Lucie River at Stuart.

Surface water on the FSC Indiantown Mill property can flow either
to the borrow pit/retention pond in the southeast corner of the
site or to the ditch along the southwest property line. Since
the borrow pit and ditch are connected, water flows from the
borrow pit/retention pond to the ditch. There is an opening in
the dike for the ditch at approximately the center of the
southern property line. Water flowing off-site through this
opening flows southwest to the perimeter ditch around the Talquin
Corporation orange groves. The perimeter ditch flows east around
the groves and discharges into a county ditch which flows south
to the St. Lucie canal.

During clean-up of PCBs from the borrow pit/retention pond in
1986, a culvert at the east end of the pond was removed. Prior
to its removal, this culvert may have allowed offsite drainage to

-16-
-------
• WELL LOCATED DOWN GRADIENT
FROM SITE "
WATER DRAIUAGE
FROM" SITE
•rre •OUNDAHY
DOWN GRADIEN
rr "34-.;

E^ POTENTIAL QROUNDWATER
' A SURFACE WATER
RECEPTORS
aoMD* rna OMWOIMTKM
1000^ 0 OOP 2QOO

SCALE IN FEET
-------
the east during periods of extremely high water. Surface water
from the culvert would have flowed north to approximately the
middle of the eastern FSC property line and then offsite to the
east.

5.3 Soil Contamination

Soil contamination at the site is due to the disposal of EC dust
on-site during the plant's operation and leaks of hydraulic fluid
containing PCBs. The concentrations of contaminants in soil are
presented in Table 1.

EC dust is the fine particulate material generated as the high
temperatures in an electric arc furnace drive off and oxidize
some of the iron and most of the other volatile metals contained
in the scrap. This silt-sized material is a listed hazardous
waste and has been given the designation K061 by EPA. Some EC
dust is present in the ash resulting from the PCS incineration.

During the period from November 1970 until November 1980,
approximately 11/000 dry tons of EC dust were deposited in two
on-site disposal areas designated as Area B on Figure 3.

The thickness of the EC dust remaining in the former disposal
area to the south of the plant site ranges from 0.75 inches to
18.5 inches and averages 9.6 inches. The line of demarcation
between the EC dust and the underlying fine sand is visually
distinguishable in extruded samples of the EC dust and underlying
soil' and is also visually distinguishable in the field.

Once exposed to the elements, EC dust tends to form a hard crust
as a result of the cementing reaction between the lime in the
dust and moisture from the atmosphere. As a result, the EC dust
is less susceptible to erosion by wind and water.

PCB contaminated soil is found in limited areas on the edge of
the previous PCB cleanup and a small area west of the slag
disposal area.

Metals contaminated sediment is found in drainage ditches
including part of the southern border of the site (see Figures 10
and 11).
-18-
-------
W (I Off TM Of SAMKMQ MTEftVM.

•COMBfT IMVIMQ lOCtTXM

MOMTOMNQ WIU LOCAT10N1
\
.
•UMMMVON C» tm PHAM • M MCPCNT

ucnucTfDwnii
ixt muf i * MMXT
PC8 CONCENTR/mONS
M SOLS AND 8EDMENT
PHASE in
nA*—r
Figure 10
-------
^^ ///*•*• T "i* v i
^ tZ». //«*~ »'r -»i «*« j
..'^ «•• /? \ \ \
•^ //fl— «- 1!"« W-» V*
•». "** /^i.*.« •.»• / «?»« iA.« •«••
••••« t MCt »(• m« Hof

AttA A \ " ""' " "^S~
•rt M^« Ns^11 **3
-------
Table 1: Concentrations of contaminants
EC Dust and Soil/Sediment
range average
EC Dust (ppm)

Cadmium 217 - 956
Lead 7520 - 27,600
Zinc 55,200 - 242,000
449
15,384
129,200
Soil/Sediment (ppm)

Cadmium 2 - 380
Lead 4 - 17,000
Zinc 32 - 110,000
PCBs 1 - 1,100
82
1,391
27,922
37
Volume of Contaminants (estimated):

EC dust and soil/sediment contaminated
with metals and low level PCBs 26,000 cubic yards

Soil/sediment contaminated with PCBs
above 50 ppm 600 cubic yards

PCB incinerator ash contaminated with
metals 10,700 cubic yards

5.4 Groundwater Contamination

During the Phase I Remedial Investigation, groundwater samples
from two wells were analyzed for the CLP/HSL constituents. The
wells were M-50, near the center of the plume, and M-20,
downgradient from the scrapyard. The CLP/HSL analyses identified
the same contaminants of concern in groundwater for which
monitoring has been performed since November 1985. The Consent
Agreement of September 1985 between FDER and FSC provided for
semi-annual sampling for these parameters until June 1990, at
which time samples were collected and analyzed annually. Because
PCBs have never been detected in the monitoring wells, analyses
for this parameter are presently performed annually. The
location of the 24 existing permanent wells are shown on Figure
12.

A groundwater plume extends south from the vicinity of the brine
discharge from the plant's former water softener to a distance of
approximately 600 feet beyond the southern property line. The
plume extends to a depth of approximately 35-40 feet. The extent

-21-
-------
LEGEND

LOCATION Of MONITOHIN* Wtll»

LOCATION Ot OICOUHIMIONIO UONITONINO OfLL*
/-10— |M a«-a CONDUCTIVITY CONTOUH fO«
(CONDUCTIVITY IN MILLIMHOt/MITINt

O LOCATION Of NIW MOMTONINO WILL*
LOCATION or raoouCTKm wtu*

ttM'ACf WAT1K MIMIM rOMT

•OHIBO
IM7
LOCATION OF GROUNDWATER MONITORING WELLS AND
EM 34 CONDUCTIVITY CONTOURS _,
-------
of the plume has been defined by. analytical data and
electromagnetic geophysical surveys. Water quality in the plume
is characterized by elevated concentrations of the following
parameters:

Table 2: Groundwater contaminant concentrations
Contaminant
Range
Average
Cadmium ( ppb )
Lead ( ppb )
Zinc (ppm)
Radium 226 (pCi/L)
228
1
7
.11 -
1

38
742
13
91

12
50
3
25
3

Estimated volume of contaminated groundwater: 365 million gallons

Several uncertainties exist with regard to the radium detected in
the groundwater. Radium-228 was measured in concentrations
substantially less than the radium-226. However, its source is
uncertain given its short half-life. Another uncertainty is the
mechanism that resulted in the elevated radium-226 concentrations
in groundwater.

Two related theories may explain the occurrence of elevated
radium levels and subsequently high gross alpha levels. First,
leaching tests with a sodium chloride solution performed on
native soil, EC dust, lime and slag indicate that the presence of
dissolved radium in the ground water plume could be a result of
the dissolved sodium chloride causing naturally occurring radium
to leach from the soil. Secondly, it is possible that naturally
occurring radium in the groundwater withdrawn by the former
production well was concentrated by cation exchange with the
column resin in the water
softener.

5.5 Surface Water Contamination

During the Phase I Remedial Investigation, a surface water sample
was collected at the only point where the off-site flow from the
property intermittently occurs, a drainage ditch on the southwest
border of the property. The sample was collected in August
because there was no off-site surface water flow when the soil
and groundwater samples were collected in May.

Class M surface water standards for zinc and iron were exceeded.
Volatile, acid or base neutral extractable organics, pesticides,
or PCBs were not detected in the sample.

During Phase II, additional surface water samples were collected
from on-site and off-site locations. Lead was detected in one

-23-
-------
sample, collected on-site from the "polishing pond." The
concentration of lead/ 31 ppb, was above existing Florida surface
water standards. Other surface water samples, collected from
private and county maintained drainage ditches, had lower lead
concentrations that decreased to a level of 8 ppb at a point near
the St. Lucie Canal.

Zinc exceeded surface water standards in three out of the seven
Phase II surface water samples. The highest zinc concentration
in the on-site samples -was 155 ppb; the highest zinc
concentration in off-site surface water samples was 45 ppb.

5.6 Potential Routes of Contaminant Migration

Groundwater is a migration route from the site. Groundwater at
depths of approximately 30 feet or more is reportedly used for
drinking water at some residences about 1/2 mile from the site.

Metals have been detected in surface water in the borrow pit.
However, surface water samples taken from the borrow pit were
either at or slightly above existing standards. Metals were
detected in surface water in drainage ditches south of the site.
The metals concentrations decreased with increasing distance from
the site.

Surface water runoff from the contaminated soil at the Site can
contain metals and is one migration route from the site. On-site
actions are expected to reduce metals concentrations in the
runoff.

Runoff from the site does provide some water to seasonal wetlands
located south/southwest of the site.

6.0 SUMMARY OF SITE RISKS

CERCLA directs that EPA must protect human health and the
environment from current and potential exposure to hazardous
substances at Superfund sites. In order to assess the current
and potential future risks for the Florida Steel Site, a risk
assessment was conducted. This section summarizes the findings
concerning the risks from exposure to soil and groundwater at the
Site. However, the treatment and disposal of contaminated
groundwater will be addressed in the second operable unit for
this Site.

6.1 Identification of Contaminants of Concern

At this Site the contaminants of concern in soil are cadmium,
chromium, lead, zinc, and PCBs. These contaminants are present
in site soils because of the on-site disposal of EC dust and from
leaks of hydraulic fluid containing PCBs. The contaminants of
concern in groundwater are cadmium, lead, and radium-226 and 228.

-24-
-------
The presence of metals in groundwater is due to the leaching of
metals from the soil and EC dust; therefore, soil cleanup levels
have been developed for the protection of groundwater. The
presence of radium in groundwater may be due to the discharge
from a water softening system which may have increased leaching
from native soils. Table 4 provides the reasonable maximum
exposure concentrations for the contaminants of concern.

6.2 Exposure Assessment Summary

Exposure pathways are identified which consist of four elements:
1) a source and mechanism of chemical release to the environment,
2) an environmental transport media (e.g., air, ground water,
surface water) for the release chemical, 3) a point of potential
human contact with the contaminated medium (referred to as an
exposure point), and 4) a human exposure route (e.g., drinking
water). Each pathway therefore describes a particular route by
which a. population or individual may be exposed to contaminants
originating from a site. Once the exposure pathways have been
identified and adequately described, receptor populations can be
identified, exposure point concentrations determined, doses and
intakes can be calculated, and any uncertainties can be
described.

The potential exposure pathways considered for the FSC site under
the no-action scenario for present and future land use are:

1) Dermal contact and ingestion of contaminated soil by
industrial workers under current and* future use conditions at the
site.

2) Non-potable use of groundwater, such as hand washing, for
future conditions at the site.

3) Residential drinking water, residential bathing and showering
at nearby off-site locations in the future if contaminated
groundwater was not treated.

Residential uses of the site were not evaluated in the risk
assessment. Deed restrictions on the use of the site have been
filed with the Martin County Clerk of Circuit Court. The deed
restrictions limit use of the site to mostly industrial or
commercial activities. The restrictions are already in effect
and will remain in effect regardless of the cleanup activities
that occur.

In addition, a coal fired power plant is to be built on adjoining
property southwest of the site. A 500-KV electric power line
will likely be erected across the western portion of the site.
Given these conditions, the existing zoning laws, and the deed
restrictions, future residential use of the site is not
anticipated.

-25-
-------
Exposure to contaminated sediment and surface water was not
evaluated because the.chance of exposure is very low at the site.
The site is located in a relatively isolated area and a fence
around the site limits the access of people who pass by.

The nearest downgradient potable well is over 1,400 feet from the
plume's boundary and is currently not impacted by the
contamination plume. Therefore, exposure to groundwater under
current conditions is not quantitatively assessed. No potable or
non-potable wells are currently in use on the site and
consequently are not assessed under the current use scenario.

With respect to future use, the locations of water supply wells
downgradient from the site are shown on Figure 9. Private and
commercial downgradient wells are reported to range in depth from
30 to 100 feet below land surface. The nearest well is more than
1,400 feet from the downgradient edge of the contaminated
groundwater plume. Groundwater samples were collected from the
two domestic wells nearest the site during the June 1987
sampling. One well is reported to be 104 feet deep and the other
well is over 100 feet deep. Concentrations of cadmium, chloride,
iron, lead, sodium, total dissolved solids, and gross alpha were
at background levels in the two domestic wells.

Given an average flow velocity of 40 feet/year and a distance of
approximately 1400 feet from the edge of the contaminated
groundwater plume to the nearest residential well, it would take
about 35 years for the plume to reach the nearest well.

Inhalation of contaminants volatilizing from the surface soil,
sediment in drainage ditches or other surface waters is not
considered to be significant at the FSC site due to the low
volume of the only contaminant, PCBs, which could potentially
volatilize.

Air sampling was conducted in the EC dust area on two consecutive
days during the Phase I investigation. The sampler was placed
immediately downwind of Area B. Wind speed varied from calm to
very windy during the 9 hour collection period on May 26, 1988
and varied from calm to breezy during the 12-hour collection
period on May 27, 1988. The results of the analyses and the OSHA
permissible exposure limits are presented in the following table:
Table 3:
Air Sampling Results (units expressed in mg/m3)
Analyte
Lead
Cadmium
Chromium
May 26, 1988
0.290
0.011
0.008
May 27,1988
0.040
0.002
0.003
8 hr. Occupational
Limits
30
200
NA
-26-
-------
The groundwater concentrations used in calculations of chemical
intakes were based on the 95% upper confidence limit (UCL) of
measured concentrations from the wells most strongly influenced
by the high total dissolved solids (TDS) plume. Flow from the
current plume boundary to potential receptors has been assumed to
follow a plug flow pattern with no attenuation or dilution.

Several assumptions and constants used to evaluate the exposure
and calculate site risk are presented in Appendix C.

6.3 Toxicity Assessment

To assess the possible toxicological effects from exposure,
health effects criteria are derived from a review of health and
environmental standards and published toxicological studies.

For risk assessment purposes, individual pollutants are separated
into two categories of chemical toxicity, depending on whether
they exhibit carcinogenic or nonearcinogenic effects.

Cancer potency factors(CPFs) have been developed by EPA's
Carcinogenic Assessment Group for estimating excess lifetime
cancer risks associated with exposure to potentially carcinogenic
chemicals. CPFs, 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 CPF. Use of this approach make
underestimation of the actual cancer risk highly unlikely.
Cancer potency factors are derived from the results of human
epidemiological studies or chronic animal bioassays to which
animal-to-human extrapolation 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 nonearcinogenic effects. RfDs, which are
expressed in units of mg/kg-day, are estimates of lifetime daily
exposure levels for humans, including sensitive individuals, that
is not likely to be without an appreciable risk of adverse health
effects. Estimated intakes of chemicals from environmental media
(e.g., the amount of a chemical ingested from contaminated
drinking water) can be compared to the RfD. RfDs are derived
from human epidemiological studies or animal studies to which
uncertainty factors have been applied. Uncertainty factors are
used 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.
-27-
-------
The applicable RfDs and CPFs are:
RfDs (mg/kg/day) CPFs (mg/kg/day)-l
Cadmium
Chromium
Chromium
Lead
Zinc

(III)
(VI) .

5
1
5
4
2
x 10-"
x 10°
x 10'3
.28 x 10'4 **
x 10'1
PCBs 7 . 7

**No cancer potency factor or reference dose has been determined
by EPA. The reference dose noted above was presented in the risk
assessment for comparative purposes only and was derived using
EPA's action level of 15 ppb for lead in drinking water.

6.4 Summary of Baseline Risk Characterization

A characterization of risk was performed in the risk assessment
to address potential risk and hazards to human health posed by
the Site in the absence of remedial action. The risk
characterization is based on identifying potential chemicals of
concern and developing exposure scenarios for each of the
potential and future exposure pathways.

Excess lifetime cancer risks are determined by multiplying the
intake level with the cancer potency factor. These risks are
probabilities that are generally expressed in scientific notation
(e.g., lxlO~6 or IE'6). An excess lifetime cancer risk of 1x10"6
indicates that, as a plausible upper bound, an individual has a
one in one million chance of developing cancer as a result of
site-related exposure to a carcinogen over a 70-year lifetime
under the specific exposure conditions at a site.

Potential concern for non-carcinogenic effects of a single
contaminant in a single medium is expressed as the hazard
quotient (HQ) or the ratio of the estimated intake derived from
the contaminant concentration in a given medium to the
contaminant's reference dose. By adding the HQs for all
contaminants within a medium or across all media to which a given
population may reasonably be exposed, the Hazard Index (HI) can
be generated. The HI provides a useful reference point for
gauging the potential significance of multiple contaminant
exposures within a single medium or across media.

This risk associated with the various exposure pathways is
summarized in Table 4. A range of 95% UCL concentrations in soil
and groundwater is often presented because subsections of the
site were each evaluated for their contribution to the risk.
However, the risk or hazard index values presented in the tables
represent a total site risk for each contaminant for each
exposure pathway.

-28-
-------
Table 4 shows that pathways which indicate the greatest concern
are dermal contact and incidental ingestion of soils and future
ingestion of the groundwater. The chemicals which drive the risk
in the soil related pathways are lead and PCBs. Lead drives the
risk in the groundwater pathway.

Cleanup levels were derived for those scenarios which, based on
the quantitative risk assessment, may adversely impact the health
of exposed individuals. The exposure pathways which were
evaluated and determined to pose either potential carcinogenic
risks greater than 10~6 and/or a hazard index exceeding one are
listed below:

1) Dermal contact and ingestion of contaminated soil by
industrial workers under current and future use conditions at the
site.

2) Ingestion of contaminated water at nearby off-site locations
in the future if contaminated groundwater was not treated.

Of the most toxic metals on-site, lead is present in the highest
concentrations. In addition, the highest potential risk is
associated with ingestion of contaminated groundwater.
Therefore, it is appropriate to base the final soil cleanup level
upon the soil lead concentration that would be protective of
groundwater. The soil lead cleanup level, 600 ppm, was
determined to be the level that would ensure that the underlying
groundwater would contain no more than 15 ppb of lead, and would
thus be protective of future residents drinking groundwater.
-29-
-------
Table 4: Summary of Baseline Risk
Current and Future Use Industrial Scenario Noncarcinogenic Risk
Soil Ingestion
Contaminant Range of 95% UCL
Exposure concentrations
Cadmium 8 - 482
Chromium 294 - 1,460
Lead 43 - 9,760
Zinc 4090 -• 134,000
TOTAL HAZARD INDEX FOR PATHWAY
Range of Chronic
(ppm) Daily Intake Values
(mg/kg/day)
3.6x10-6/1.1x10-4
6.9x10-5/1.2x10-4
1.0x10-5/2.3x10-3
9.6x10-4/3.1x10-2

Reference Dose
(mg/kg/day)
5x10-4
1x10°
4.28x10-4*
2.0x10-1

HQ
• .12
.0007
6.9
7.18
*Reference dose for lead was calculated for comparison purposes only.
EPA reference dose.
It is not an appn
Current and Future Use Industrial Scenario Noncarcinogenic Risk
Soil Dermal Contact
Contaminant Range of 95% UCL
Exposure concentrations
Cadmium 8 - 482
Chromium 294 - 1,460
Lead 43 - 9,760
Zinc 4090 - 134,000
TOTAL HAZARD INDEX FOR PATHWAY
Range of Chronic
(ppm) Daily Intake Values
(mg/kg/day)
6.6x10-7/3.9x10-5
2.3x10-5/1.2x10-4
4.4x10-6/7.8x10-4
1.6x10-3/5.3x10-2

Reference Dose
(mg/kg/day)
1x10-3
1x10°
4.28x10-4 2
2.0x10-1
2
HQ
.04
.0002
.3
^05.
.39
-30-
-------
Table 4: Summary of Baseline Risk (cont.)
Future Use Industrial Scenario Noncarcinogenic Risk
On-site Dermal Contact with Groundwater (handwashing)
Contaminant 95% UCL Exposure
Concentrations (ppm)
Cadmium 20
Lead 80
TOTAL HAZARD INDEX FOR PATHWAY
Chronic Daily
Intake Values
(mg/kg/day)
2.8x10-8
1.1x10-7
Reference Dose
(mg/kg/day)
5x10-4
4.28x10-4*
HQ
.0001
.0003
.0004
Future Ingestion of groundwater by nearby residential adult and child, Noncarcinogenic Risk
Contaminant 95% UCL Exposure
Concentrations (ppm)
Child
Cadmium 20
Lead 80
TOTAL HAZARD INDEX FOR CHILD PATHWAY
Adult
Cadmium 20
Lead 80
TOTAL HAZARD INDEX FOR ADULT PATHWAY
TOTAL HAZARD INDEX FOR PATHWAY
Chronic Daily
Intake Values
(mg/kg/day)
1.2x10-3
4.7x10-3
5.7x10-4
2.3x10-3

Reference Dose
(mg/kg/day)
5x10-4
4.28x10-4*
5x10-4
4.28x10-4*

HQ
2.4
11.0
13.4
1.1
5^4
6.5
19.9
-31-
-------
Table 4: Summary of Baseline Risk (cont.)
Current and Future Use Industrial Scenario Carcinogenic Risk
Soil Ingestion
Contaminant Range of 95% UCL
Exposure concentrations
(ppm)
PCS 1248
PCB 1254
8.0 - 16
.78 - 5.3
TOTAL RISK FOR PATHWAY
Range of Lifetime
Avg. Daily Dose
(mg/kg/day)

1.2x10-6/3.7x10-6
1.0x10-7/2.2x10-6
Cancer Potency
Factor (mg/kg/day)-1
Risk
7.7
7.7
3.-67x10-5
6.3x10-6

4.3x10-5
Current and Future Use Industrial Scenario Carcinogenic Risk
Dermal Contact with Soil
Contaminant Range of 95% UCL
Exposure concentrations
(ppm)
PCB 1248
PCB 1254
8.0 - 16
.78 - 5.3
TOTAL RISK FOR PATHWAY
Range of Lifetime
Avg. Daily Dose
(mg/kg/day)

1.9x10-6/3.7x10-6
1.2x10-6/1.8x10-7
Cancer Potency
Factor (mg/kg/day)-l
7.7
7.7
Risk
6.2x10-5
1.1X10-5

7.3x10-5
-32-
-------
Table 4: Summary of Baseline Risk (cont.)
Future Ingestion of Groundwater; Nearby Residential Carcinogenic Risk
Contaminant Average Exposure
Concentrations (pCi/L)
Radium 226 24.6
Radium 228 2.9
TOTAL RISK FOR PATHWAY

Lifetime Dose
(pCi/lifetime)
538,740
63,510

Cancer Slope
Factor (pCi/l)-l
1.0x10-10
1.2x10-10
•
Risk
6x10-6
6.5x10-5
7.1x10-5
Current and Future Industrial Scenario Carcinogenic Risk
Dermal contact with groundwater (handwashing)
Contaminant
Average Exposure
Concentrations (pCi/L)
Radium 226 24.6
Radium 228 2.9
TOTAL RISK FOR PATHWAY
Lifetime Dose
(pCi/lifetime)
34.9
4.1
Cancer Slope Risk
Factor (pCi/l)-l
1.0x10-10 4.1x10-10
1.2x10-10 4.6x10-9
5.0x10-9
Future Use Nearby Residential Carcinogenic Risk
Dermal contact with groundwater (bathing)
Contaminant
Radium 226
Radium 228
Average Exposure
Concentrations (pCi/L)
24.6
2.9
Lifetime Dose
(pCi/lifetime)
1212
143
Cancer Slope
Factor (pCi/l)-l
1.0x10-10
1.2x10-10
TOTAL RISK FOR PATHWAY
Risk
1.4x10-8
1.5x10-7
1.6x10-7
-33-
-------
6.5 Environmental Risks

To date, no endangered or threatened species or associated
habitats have been identified on-site.

Site contaminants have been detected at low levels in surface
water from a retention pond on-site. Fish are present in the
pond; ducks and other birds have been seen occasionally at the
pond. The pond received some runoff from a portion of the
contaminated areas of the site.

Site contaminants have been detected in the sediment and surface
water of seasonally flooded wetlands adjacent to the site. On-
site cleanup of contaminated soil is expected to reduce the
metals levels in surface water runoff and ultimately improve
surface water quality in the on-site pond and the off-site
wetlands. Sampling will be required to document changes in
surface water quality. Contaminated wetland sediment and
contaminated groundwater will be evaluated in a second operable
unit.

6.6 Risk Uncertainty

There is a generally recognized uncertainty in human risk values
developed from experimental data. This is primarily due to the
uncertainty of extrapolation in the areas of (1) high to low dose
exposure and (2) animal data to values that are protective of
human health. The site specific uncertainty is mainly in the
degree of accuracy of the exposure assumptions. Most of the
exposure assumptions used in this and any risk assessment have
not been fully verified. For example, the degree of chemical
absorption from the gut or through the skin or the amount of soil
contact that may occur is not known with certainty. Generally
accepted default values provided in Agency guidance were used
when available.

In the presence of such uncertainty, the Agency and the risk
assessor have the obligation to make conservative assumptions
such that the chance is very small, approaching zero, for the
actual health risk to be greater than that determined through the
risk assessment process. On the other hand, the process is not
intended to yield absurdly conservative risks values that have no
basis in reality. That balance was kept in mind in the
development of exposure assumptions and pathways and in the
interpretation of data and guidance for this baseline risk
assessment.

For this site-specific risk assessment, a quantified risk
analysis for the trespasser exposure scenario was not conducted.
The risk to a trespasser was deemed to be negligible at the
Florida Steel Site compared to the risk to current and future
workers because it is an industrial site in an isolated area

-34-
-------
(that is zoned industrial) and the site is completely fenced. In
addition, the risk assessment was first submitted in November
1989 which was prior to the release of EPA's present guidance
which recommends that this pathway be quantified in the risk
assessment.

6.7 Risk Conclusion

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.

The exposures that are of greatest concern are dermal contact and
incidental ingestion of soils and future ingestion of the
groundwater. The chemicals which drive the risk for the soil
related exposures are lead and PCBs. Lead drives the risk for
the groundwater exposure.

7.0 SUMMARY OF ALTERNATIVES

The remedial alternatives developed in the FS report for this
site are divided into two groups: 1) treatment for PCB
contaminated soils and sediment; and 2) treatment for EC dust
and metal contaminated soils or sediment. This section of the
ROD presents a summary of each of the alternatives.

ALTERNATIVES FOR PCB CONTAMINATED SOIL

Alternative 1-P: No Action
Capital Costs: $ None
O&M Costs: None
Total Present Worth: None

The Superfund program requires the "No Action" Alternative to be
evaluated at every site to serve as a baseline for comparison
with the other alternatives. Under this alternative, no further
action would be taken to minimize the impact of site
contaminants.

Alternative 2-P: Excavation, Off-site disposal; On-site
Solidification/disposal
Capital Costs: $ 306,750
O&M Costs: None
Total Present Worth: $ 306,750
Time to Complete: Six months

Under this alternative, PCB contaminated soils would be addressed
by two different methods. For soil with PCB levels greater than
50 ppm, the soil would be excavated and shipped off-site to a

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RCRA/TSCA approvecl disposal facility. For soil with PCB levels
between 25 and 50 ppm, the contaminated soil would be solidified
and placed in the on-site landfill with the metal contaminated
soil. Excavation would continue until the cleanup goals are met
or the water table is encountered. The excavated areas would be
graded and grass*ed.

The soil with PCB concentrations above 50 ppm also contains
metals. Any necessary treatment will be dependent upon the
chosen disposal facility. Treatment is not expected to
significantly increase overall site cleanup costs because of the
small estimated volume of affected soil (600 cubic yards).

ALTERNATIVES FOR EC DUST, LEAD CONTAMINATED SOIL, SEDIMENT, AND
ASH
Alternative 1-S: No Action
Capital Costs: $12,000
O&M Costs: $25,000/year for 30 years
Total Present Worth: $345,000

No further action would be taken to minimize the impact of site
contaminants. Monitoring of air and groundwater quality would be
conducted for up to 30 years to document changing site conditions.

Alternative 2-S: Excavation, Off-site
Treatment and Disposal
Capital Costs: $20,990,000
O&M Costs: $12,800/year for 30 years
Total Present Worth: $21,160,000
Time to complete: 15 months

This alternative involves excavation of residual EC dust, soil with
lead levels above 600 ppm, and slag with total lead levels above
1360 ppm or above the Toxicity Characteristic Leaching Procedure
(TCLP) standards noted on page 38. The lead level of 1360 ppm was
derived in the risk assessment as an allowable value for direct
contact in an industrial setting. In addition, incinerator ash
would be removed from its current location in a covered building
on-site. All material described above would be shipped to an EPA
approved High Temperature Metal Recovery facility for treatment
and disposal. This process heats the contaminated material to a
temperature high enough to volatilize the individual metals which
are collected in baghouses. Zinc can usually be collected in
sufficient quantities for recycling.

The excavated area would be graded and grassed. Surface water
runoff from the site would be retained on-site until remedial
activities were complete and surface water quality was sufficient
to allow a flow off site. Groundwater quality would be monitored
for up to 30 years.

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Alternative 3-S: Excavation, On-site solidification and
disposal in an on-site Double Lined RCRA Landfill with RCRA cap
Capital Costs:$6,456,000
O&M Costs: $18,200/year for 30 years
• Total Present Worth: $6,698,000
Time to Complete: 12 months

This alternative involves excavation of residual EC dust, soil
with lead levels above 600 ppm, and slag with total lead levels
above 1360 ppm or above the TCLP standards noted on page 38. No
excavation below the water table would occur. In addition,
incinerator ash would be removed from its current location, a
covered building on-site. The material would then be treated on-
site by solidification. Solidification involves mixing the
contaminated material to achieve a hardened mass. The hardened
mass reduces the mobility of the contaminants. Compliance with
RCRA Land Disposal Restriction (LDR) treatment standards for EC
dust, which is the listed RCRA waste K061, would be achieved by
meeting levels specified in the treatability variance for
contaminated soil and debris.

The solidified material would be placed in an on-site RCRA
landfill with double liners and a leachate collection system and
covered with a RCRA cap. The base may be constructed from slag
that passes the cleanup goals specified for slag. Such a base
would elevate the solidified material above the surrounding land
surface, thus increasing the distance between the water table and
solidified material. The base would not substitute as bottom
liner of the landfill unless it met the requirements for bottom
liners found at 40 C.F.R 264.301 (c).

The excavated area would be graded and grassed. Surface water
runoff from the site would be controlled and routed to the
stormwater retention pond on-site until remedial activities were
complete and surface water quality was sufficient to allow a flow
offsite. Groundwater quality would be monitored for up to 30
years.

Alternative 4-S: Excavation, Solidification
Solidification, On-site Disposal in Single Lined Landfill with
RCRA Cap
Capital Costs: $5,856,000
O&M Costs: $18,200/year for 30 years
Total Present Worth: $6,098,000
Time to complete: 9 months

This alternative is similar to alternative 3-S except for
differing landfill design requirements. Under this alternative,
the landfill would have only one liner and would not have a
leachate collection system. The landfill would be covered with a
RCRA cap.

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For each alternative considered for metals contaminated material
at this site, all visually distinguishable EC dust remaining at
the site would be excavated and treated. Soil contaminated with
lead above 600 ppm would also be excavated and treated. Also,
drainage ditch sediments with lead levels above 600 ppm would be
excavated and treated.

Zinc, the most common metal contaminant at the site, is generally
present at levels 8 times higher than lead. Therefore, based on
the lead cleanup goal of 600 ppm, the zinc cleanup level would be
approximately 4800 ppm. For comparison, an estimated acceptable
soil zinc level in a residential setting would be approximately
50,000 ppm (EPA Risk Assessment Guidance for Superfund).

For the alternatives involving on-site treatment of metal
contaminated material, compliance with the LOR treatment levels
specified for EC dust, which is a RCRA listed waste K061, would
be achieved by meeting the standards specified in the
treatability variance for contaminated soil and debris. A
comparison of the treatability variance levels for contaminated
soil and debris (EPA 9347.3-06FS, 09-90) and the LDR levels for
low zinc EC dust is presented below:

Table 5: Treatment Levels for K061 Wastes (in mg/1 TCLP extract)

Treatability Variance Levels LDR treatment standards
Cadmium
Chromium
Lead
Nickel
.2
.5
.1
.5
- 2
- 6
- 3
- 1
.14
5.2
.24
.32
Cleanup standards for slag are the TCLP standards for substances
listed in RCRA Section 261.24, Table 1 and a total lead level no
greater than 1360 ppm. The applicable TCLP standards for slag
include, but are not limited to:

Cadmium 1 mg/1
Chromium 5 mg/1
Lead 5 mg/1
Silver 5 mg/1

Given the TCLP values presented in the FS, the leachability of
slag is expected to be very low. TCLP values ranged from less
than .5 mg/1 to 1.3 mg/1 of lead for slag samples containing
total lead concentrations of 545 to 758 ppm.
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The single lined landfill was originally presented in the FS as
an appropriate option. However, it has since been determined
that a facility specific delisting for the stabilized K061 would
be required in order for the waste to be disposed of in a
landfill meeting subtitle D design requirements.
•
The cleanup standard for PCB contaminated soil is based on the
TSCA Spill Cleanup Policy for areas with restricted access. The
standard, 25 ppm, does not apply to those areas previously
cleaned to a level of 50 ppm.

Some bench scale testing has been performed on varying mixtures
of EC dust, soil, and cement to evaluate the effectiveness of
solidification. These initial results were presented in the
Phase II RI Report. As part of the testing, unconfined
compressive strength, permeability and EP toxicity were measured.
8 out of 12 samples of "pure" EC dust mixed with varying amounts
of cement yielded EP toxicity values less than 3 mg/1.
Additional treatability testing will be required to refine the
mix of ingredients that will ensure that the solidified material
will meet the TCLP standards noted in the treatability variance
for contaminated soil and debris and in Table 5.

Additional standards for the solidified material will be
developed during the remedial design. These standards may
include:
- permeability less than or equal to 10"6 cm/sec
- unconfined compressive strength
-r satisfactory performance during the American Nuclear Society
(A.N.S.) 16.1 leach test procedure.

Another factor that will be evaluated during the treatability
study will be the potential for volatilization of PCBs during the
solidification process. Soil containing PCBs between 25 and 49
ppm will be solidified and disposed of in the on-site landfill.

Groundwater use restrictions may be needed to prevent
disturbances of the off-site groundwater plume until the
groundwater cleanup is completed. Possible disturbances may
include the installation of water supply wells or excavation
below the water table.
8.0 COMPARATIVE ANALYSIS

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): meeting requirements of other laws that
relate to the actions proposed for the site.

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•Long term effectiveness and permanence
•Reduction of toxicity, mobility, or volume through treatment
•Short term effectiveness
•Implementability: being technically and administratively
possible
•Costs
•State Acceptance
•Community Acceptance

Overall Protection; The "No Action" alternative, would not
protect human health and the environment and will not be
evaluated further in the selection of cleanup alternatives.

The remaining alternatives would provide protection of human
health and the environment by utilizing treatment to minimize or
control the risk associated with exposure to Site contamination.
Alternative 2-P would greatly reduce the risk of dermal contact
and ingestion of PCB contaminated soil.

Alternative 3-S would greatly reduce the risk of dermal contact
and ingestion of metal contaminated soil, including EC dust, by
solidifying the waste and disposing it in an on-site landfill.
The landfill design would provide a high degree of protection for
groundwater.

Compliance with ARARS: The alternatives considered for the site
would meet their respective applicable or relevant and
appropriate requirements (ARARs) of Federal and State
environmental laws or justify a variance from those laws.

As part'of alternatives 3-S and 4-S (EC dust and metal
contaminated soil), compliance with the RCRA LDR treatment
standards for the EC dust (RCRA listed waste K061) would be
achieved by meeting the treatment levels specified in the
treatability variance for contaminated soil and debris.

Long term effectiveness and permanence; All remedial
alternatives considered, except the no-action alternative, offer
long term effectiveness and permanence. Alternative 2-S, off-
site treatment of the EC dust and lead contaminated soil,
represents an effective method to reduce the risk associated with
that material. The metals in the EC dust and lead contaminated
soil would be separated by the HTMR process and recycled.

Alternative 3-S and 4-S, solidification of EC dust and metals
contaminated soil, is an effective and permanent method of
reducing the risk associated with the EC dust and metals
contaminated soil and ash because the contaminants are
permanently bound in a cement matrix.
These alternatives would also serve to limit, to the extent
practicable, the source of metals contamination in the

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groundwater. Alternative 3-S, solidification and disposal in the
on-site RCRA double lined landfill, provides an extra.measure of
protection for groundwater.

Alternative 2-P, off-site disposal of soil containing greater
than 50 ppm of PCBs would offer protection by proper disposal in
a permitted hazardous waste facility. Solidification of the low
level PCB contaminated soil is an effective and permanent
treatment method for the remediation of the Florida Steel Site.

Reduction of Toxicitv, Mobility, or Volume Through Treatment;
Use of HTMR, as described in Alternative 2-S, will greatly reduce
the toxicity of EC dust and lead contaminated soil. Alternative
3-S, solidification of the EC dust, lead contaminated soil and
ash will increase the volume of material that would be placed in
the on-site vault. However, mobility of the metals will be
greatly reduced because they will be permanently bound up in a
cement matrix.

Alternative 2-P includes off-site disposal of high levels of PCB
contaminated soils and on-site solidification of low level
contamination. Off-site disposal of PCB contaminated soil will
indirectly reduce the mobility of the contaminants by isolating
the material in a secure landfill, thus reducing the forces which
drive mobility. On-site solidification of the lower level
contaminated soil would increase the volume of the material to be
placed in the on-site vault, but the mobility would be
substantially reduced by the cement matrix.

Short-term effectiveness; After implementation, all of the soil
and ash alternatives, 2-S, 3-S, 4-S, and 2-P, will remove the
risk associated with direct exposure to the contaminated
material. However, cleanup workers could experience a short term
risk due to direct contact, inhalation, or ingestion during
excavation and movement of the soil, ash, and EC dust. Airborne
emissions of dust will be monitored and controlled to minimize
exposure off-site.

Alternative 2-S, HTMR, is not as effective in the short term
because of the possibility of traffic accidents with trucks
hauling EC dust and metal contaminated material off-site. In
addition, the capacity of HTMR facilities is not certain; costs
and time required for cleanup could increase depending on
capacity of the HTMR facilities. For these reason, HTMR may have
a reduced implementability.

Implementability; Alternative 2-S (off-site disposal of EC dust
and metal contaminated soil and ash) will take longer to
implement since it is dependent upon the rate at which the off-
site treatment facility can accept the materials. Alternatives
3-S and 4-S (solidification of EC dust and metal contaminated
soil and ash) could be implemented more quickly.

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Alternative 2-P (off-site disposal/on-site solidification for PCB
contaminated soil) would not be difficult to implement. The
volume of soil involved is relatively small so the disposal
facility should be able to quickly accept the material. The
solidification of low level PCBs is an established technology and
is implementable,.

Costs; The estimated total present worth costs of each remedy is
discussed in this section. The cost associated with Alternative
1-S, the no action alternative for lead contaminated soils is
$345,000. The cost for Alternative 2-S is $21,160,000. The cost
for Alternative 3-S is $6,698,000. The cost for Alternative 4-S
is $6,098,000. The cost for Alternative 1-P, the no-action
alternative for PCB contaminated soil, is zero. The cost for
Alternative 2-P is $306,750.

The action alternatives have substantially higher costs due to
increased efforts to permanently treat the contamination present
in the soil and groundwater. This includes on-site
solidification of the EC dust and metals contaminated soil and
ash (Alternative 4-S), off-site disposal of PCB contaminated soil
with concentrations above 50 ppm, and on-site solidification of
PCB contaminated soil with concentrations between 25 and 50 ppm
(Alternative 2-P).

State Acceptance; The State of Florida has concurred with this
Record of Decision.

Community Acceptance; The Martin County Board of Commissioners
and local citizens agree that site remediation is necessary;
however they are currently opposed to a possible discharge of
treated groundwater to the St. Lucie Canal as was stated in EPA's
Proposed Plan (see Section 11 - Explanation of Significant
Changes).

9.0 SELECTF-n Rgamnv

Based upon consideration of the requirements of CERCLA, the
detailed analysis of the alternatives, and public comment, EPA
has selected the following remedy for the site:

•Excavation and off-site disposal at an EPA approved facility of
approximately 600 cubic yards of soil contaminated with PCB
levels equal to or greater than 50 ppm.

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No excavation below the water table will occur unless- the water
treatment system anticipated for the second operable unit is
operational. However, at this time it is not anticipated that
excavation below the water table will be required.

•Control of surface water runoff from the site during remediation
of on-site soils.

•Compliance with Resource Conservation and Recovery Act (RCRA)
Land Disposal Restriction treatment standards for EC dust/ which
is a listed RCRA waste, K061, by meeting levels specified in the
treatability variance for contaminated soil and debris.

•Periodic monitoring of surface water and groundwater quality.
The quality of surface water runoff should be consistent with
possible future criteria developed for the adjacent wetlands in
the second operable unit for this site. Groundwater quality
would be monitored for up to 30 years.

Appropriate dust control measures shall be used to reduce the
potential for airborne transport of site contaminants during the
remedial action, especially during the excavation of EC dust and
contaminated soil. Similar steps will also be taken during
removal of the incinerator ash for solidification.

PCB contaminated soils that are excavated and temporarily stored
on-site pending final treatment and/or disposal roust be stored in
a manner that will prevent the PCBs from being carried away in
surface water runoff. For example, stockpiled soil should be
covered with tarps or be contained within berms. In addition,
any temporary storage of PCB contaminated soils may be subject to
TSCA requirements limiting storage to 30 days or less.

Groundwater monitoring will be performed to ensure that soil lead
cleanup levels and the proposed landfill measures will remain
protective of groundwater. However, if suggested by results of
the monitoring, additional site cleanup may be necessary. This
additional site cleanup may include, but not be limited to,
additional soil excavation and treatment, modifications to the
landfill cover, etc.

As part of the remedial action, all surface water runoff will be
controlled and routed to the on-site surface water retention
pond. Surface water samples will be collected and analyzed for
the site contaminants. The control of surface water runoff and
analysis of surface water samples may continue for at least two
years after all on-site construction has been completed. This

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should allow time to determine the effect of controlling the
source of metals contamination upon surface water quality.

The total present value cost of the selected remedy is
approximately $7 million dollars. For the EC dust and
contaminated soij., this cost includes O&M costs of $l8/200/year
for up to 30 years. The volume of soil that would be treated
under the selected remedy would be approximately 37,600 cubic
yards.

9 .1 Remediation goals

Based on the results of the RI/ FS reports and the risk
assessment, remediation levels were developed that would be
protective of human health and the environment. These levels
form the basis for the remedial activity to be taken at this
site.

EPA and FDER derived a soil lead cleanup level of 600 ppm. This
value is based upon, .the leachability of lead from soil into the
underlying groundwater and is a level calculated to be protective
of groundwater. EPA's recommended cleanup level for lead in
groundwater, 15 ppb, was used as the basis for the derivation of
this lead soil cleanup level.

This value was calculated by first determining an average soil
lead concentration and an average groundwater lead concentration
for an area of the site where a cause and effect relationship
could be established. In addition, EPA arrived at a similar
cleanup value for lead in soil by using the Summers model and
site specific parameters.

Slag, which contains lead, will be cleaned up to 1360 ppm, a
level protective of human health in an industrial setting. Slag
may not be subject to the cleanup level based on groundwater
protection because it produces low levels of lead in leachate and
is not a threat to groundwater for levels below 1360 ppm.
Toxicity Characteristic Leaching Procedure (TCLP) results are
included in the FS (see also Section 5.1 of ROD). However,
additional TCLP testing will be conducted during the remedial
design.

Some treatment of the soil containing PCBs above 50 ppm may be
necessary before disposal in the offsite RCRA/TSCA approved
landfill. Some of the PCB contaminated soil contains elevated
levels of metals. The disposal facility will be responsible for
ensuring that the PCB and metal contaminated soil is disposed of
in accordance with appropriate regulations. Treatment and
disposal costs of these soils are not expected to significantly
increase because of the limited volume (600 cubic yards) of
affected soil.
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The PCB cleanup level of 25 ppm .is based on the regulations
referred to in the Toxic Substances Control Act PCB Spill Cleanup
Policy for areas with restricted access.

10.0 STATUTORY DETERMINATIONS

Under its legal authorities, EPA's primary responsibility at
Superfund sites is to undertake remedial actions that achieve
adequate protection of human health and the environment. In
addition, Section 121 of CERCLA establishes several other
statutory requirements and preferences. These specify that, when
complete, the selected remedial action for this site must comply
with applicable or relevant and appropriate environmental
standards established under Federal and State environmental laws
unless a statutory waiver is justified. The selected remedy also
must be cost-effective and utilize permanent solutions and
alternative treatment technologies or resource recovery
technologies to the maximum extent practicable. Finally, the
statute includes a preference for remedies that employ treatment
that permanently and. significantly reduce the volume, toxicity,
or mobility of hazardous wastes as their principal element. The
following sections discuss how the selected remedy meets these
statutory requirements.

10.1 Protection of Human Health and the Environment

The selected remedy, including solidification of EC dust, metals
contaminated soil and ash, and soil with PCB concentrations
.between 25 ppm and 50 ppm will eliminate the source of
contamination. The selected remedy will also greatly reduce the
threat of dermal contact with contaminated soil.

Excavation and proper off-site disposal of soil with PCB
concentrations above 50 ppm will also greatly reduce the threat
of dermal contact with contaminated soil.

Eliminating the source of contamination will result in improved
surface water quality thereby reducing the amount of
contamination that could be carried away in site runoff. In
addition, the metals that could leach into the groundwater will
be removed.

10.2 Compliance with ARARs

The select remedy will meet the following ARARs:

Resource Conversation and Recovery Act (RCRA)

- Compliance with federal RCRA LDRs for RCRA listed waste
K061 (EC dust) will be achieved by meeting treatment levels
specified in the treatability variance for contaminated soil

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and debris. The treatment standards are listed in Table 5
on page 38..

- 40 C.F.R. Part 261 Subpart C: Characteristics of Hazardous
Waste

The preliminary TCLP results for slag presented in the FS
indicate that slag does not exhibit the characteristic of
toxicity. Additional TCLP sampling will be conducted as
part of the remedial design.

- 40 C.F.R. Part 264 Subpart N: Landfill Requirements

- 40 C.F.R. Part 268 Subpart C: Prohibitions on Land
Disposal

- 40 C.F.R. Part 268 Subpart D: Treatment Standards

EC dust is a listed RCRA waste, K061. According to the
LDRs, a listed, .waste must be treated to its specific
treatment standards before disposal. At this site, the EC
dust is considered "low zinc." Five samples of EC dust were
analyzed during the RI. The average zinc concentration was
129,320 ppm or 12.9% zinc. Standard deviation was 70,000
ppm.

As noted previously, compliance with the LOR treatment
levels specified for EC dust, which is a RCRA listed waste
•K061, would be achieved by meeting the standards specified
in the treatability variance for contaminated soil and
debris (OSWER 9347.3-06FS, 09/90).

Placement, as defined in the RCRA LDRs, will occur as part
of the on-site actions. However, the material will be
treated to the levels specified in the variance before its
disposal in the on-site landfill.

Toxic Substances Control Act (TSCA)

40 C.F.R. Part 761 Subpart D: Storage and Disposal of
PCBs

- 40 C.F.R. Part 761 Subpart G: PCS Spill Cleanup Policy

- 40 C.F.R. Part 761 Subpart K: PCB Disposal Record Keeping

Other:
- Federal Occupational Safety and Health Administration Act
(OSHA): The selected remedial action contractor will develop
and implement a health and safety program for its workers.
All on-site workers will meet the minimum training and
medical monitoring requirements outline in 40 CFR 1910.

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- National Ambient Air Quality Standards (NAAQS)

- Florida Department of Environmental Regulations - Class
III Surface Water Quality Standards

To Be Considered (TBC):

- 06/21/90 OSWER recommendation: a protective cleanup level
for lead in water of 15 ppb.

10.3 Cost effectiveness:

The selected remedy has an estimated total present worth of
approximately $7 million dollars. The selected remedy affords
overall effectiveness proportional to its costs. When the
relationship between cost and overall effectiveness of the
selected remedy is viewed in light of the relationship between
cost and overall effectiveness of the other alternatives, the
selected remedy is cost effective.

Capital costs:

-Disposal of soil contaminated with PCBs > 50 ppm: $306,750
-Solidification of EC dust, metal contaminated
material, and soils with PCB levels between
25 and 50 ppm : $6,456,500

O&M costs per year (for up to 30 years) : $18,200

EC dust and metal contaminated material represent the largest
volume of site contaminants and the a source for continuing
groundwater contamination. Solidification and disposal of this
material in an on-site RCRA landfill is an effective method to
address the principal source of contamination.

10.4 Utilization of Permanent Solutions and Alternative
Treatment or Resource Recovery Technologies to the Maximum
Extent Practicable

EPA has determined that the selected remedy provides the best
balance among the nine evaluation criteria for the alternatives
evaluated. The remedy uses permanent solutions and treatment
technologies to the maximum extent practicable. The EC dust,
soil, and groundwater remedy provides short and long term
protection for human health and the environment, is readily
implementable, is cost effective and is consistent with future
response actions that may be undertaken at the site.
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10.5 Statutory Preference for Treatment as a Principal
Element .

The statutory preference for treatment of soil contamination will
be met at this site. The principal threat at this site is
ingestion and dermal contact with contaminated soil and the
future migration of contaminants from soil into groundwater. The
selected remedy will use treatment for the metal contaminated
material (EC dust, soil, ash), which represents the largest
source of contamination. Treatment of the metal contaminated
material will greatly reduce the risk associated with ingestion
and contact with contaminated soil, sediment, and ash and will
remove the source of future groundwater contamination.

On-site treatment of soil with PCB concentrations above 50 ppm
was not considered worthwhile because of the small volume of
contaminated media relative to the high costs of effective
technologies. However, some treatment may be required before
disposal in the RCRA/TSCA approved landfill because of the
presence of metals an some of the PCB contaminated soil.

11.0 EXPLANATION OF SIGNIFICANT CHANGES

The Proposed Plan was released for public comment in April 1992.
The Proposed Plan identified a combination of Alternative 3-S:
excavation, onsite solidification and disposal in an on-site
double lined RCRA landfill; Alternative 2-P: Excavation and
offsite disposal for soils with PCB concentrations above 50 ppm
and excavation, on-site solidification and disposal in the
planned landfill noted above for soils containing PCBs between 25
and 50 ppm; and Alternative 2-GW: groundwater treatment and
discharge to the St. Lucie Canal or the POTW or an industrial
user.

EPA reviewed all written and verbal comments submitted during the
public comment period. Upon review of these comments, EPA, in
consultation with the State of Florida, decided to defer the
groundwater component of the proposed remedy to the second
operable unit for this site. This will allow EPA to initiate
cleanup of the contaminated soils which are a source of
groundwater contamination, while a further evaluation is
conducted of discharge methods for treated groundwater. EPA will
issue a second proposed plan for the second operable unit at the
Site and will again seek community input prior to the selection
of a remedial action for the contaminated groundwater and
wetlands.
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References
Completion Report, Task I PCB Remedial Action Plan, Florida
Steel Corporation Indiantown Mill, Indiantown, Florida,
dated October 2, 1986, Ardaman and Associates.

Phase I Remedial Investigation Report, Florida Steel
Corporation Indiantown Mill Site, dated September 30, 1988,
Ardaman and Associates.

Phase II Remedial Investigation Report, Florida Steel
Corporation Indiantown Mill Site, dated October 17, 1989,
Ardaman and Associates.

Human Health and Environmental Risk Assessment of the
Florida Steel Corporation Indiantown Mill Site, dated
January 1991, Envirologic, Inc.

Results of Groundwater Sampling Through June 1991, Florida
Steel Corporation Indiantown Steel Mill, dated December 19,
1991, Mark Schultz Associates

Feasibility Study Report, Florida Steel Corporation
Indiantown Mill Site, dated March 13, 1992, Ardaman and
Associates.
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APPENDIX C: RISK CALCULATION CONSTANTS

Several assumptions and constants used in determining exposure
and calculating site risks and are presented in the following
tables:

Current and Future Use Scenarios
Soil Ingestion
Relative Absorption
Ingestion Rate
Exposure Frequency
Exposure Duration
Body Weight
Averaging Time
1 (unitless)
50 rag/day
120 days/year
40 years
70 kilograms (kg)
14,600 days
1 (unitless)
50 mg/day
120 days/year
40 years
70 kg
25,500 days
Current and Future Use Scenarios
Soil Dermal Contact

Noncarcinogenic
chronic effects
Carcinogenic
effects
Adherence factor
Relative absorption*
Skin Surface Area
Exposure Frequency
Exposure Duration
Body Weight
Averaging Time
1 mg/cm2
.01 unitless
1700 cm2
120 days/year
40 years
70 kg
14,600 days
1 mg/cm2
.05 unitless
1700 cm2
120 days/year
40 years
70 kg
25,500 days
* .01 - inorganics
.05 - PCBs
-------
APPENDIX C (cont.)

Future Use Scenarios
Dermal Contact with Groundwater (handwashing)
Nonearcinogenic
chronic effects
Carcinogenic
effects
Skin Surface Area
Exposure Time
Exposure Frequency
Exposure Duration
Body Weight
Averaging Time
1700 cm2
.167 hrs/day
120 days/year
40 years
70 kg
14,600 days
1700 cm2
.167 hrs/day
120 days/year
40 years
70 kg
25,500 days
Nearby Residential Future Use
Ingestion of Groundwater
Noncarcinogenic
chronic effects
Carcinogenic
effects
Body weight Adult
child
Ingest ion rate Adult
Child
Relative absorption
Exposure Frequency
Exposure Duration
Adult
Child
Averaging Time Adult
Child
Lifetime Dose

70 kg
17 kg
2 I/day
1 I/day
1 unitless
365 days /year

30 years
6 years
10,950 days
2,190 days
538,740
63,510
70
17
2
1
NA
365

30
6

pCi/L (Ra-226)
pCi/L (Ra-228)
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APPENDIX C (cont.)

Nearby Residential Future Use

Dermal contact with groundwater (bathing)
Exposed Skin Surface Area Adult
Child
Exposure Time (hours/day)
Exposure Frequency (days /year)
Exposure Duration (years) Adult
Child
Averaging Time (days) Adult
Child
Permeability Rate (cm/hr)
18,000 cm2
5,760
.33
365
30
6
10,950
2,190
5.0E-4
18,000
5,760

365
30
6
10,950
2,190

cm2

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