United States   .     Office of
          Environmental Protection   Emergency and
          Agency           Remedial Response
EPA/ROD/R04-92/116
September 1992
vxEPA    Superfund
          Record of Decision:
          Standard Auto Bumper, 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 1. REPORT NO. 2.
PAGE EPA/ROD/R04-92/116
4. TMeendSUbWe
SUPERFUND RECORD OF DECISION
Standard Auto Bumper, FL
First Remedial Action - Subsequent to follow
7. AUharM




U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
1* fwctpiwii • AccMSMOfi No.
«. Report (Me
09/28/92
«.
«. Performing OroantartonBept. No.


11. CoMnd(C) or «eM(a) No,

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EPA/ROD/R04-92/116
Standard Auto Bumper, FL
First Remedial Action - Subsequent to follow

Abstract (Continued)

1989 and 1990, a removal action included soil excavation of the discharge trench area and
offsite disposal of the material.   The primary source of contamination was determined to
be the electroplating process waste streams.  This ROD addresses onsite contaminated soil
to reduce the migration of these contaminants to the ground water.  Remediation of
contaminated ground water will be addressed in a subsequent ROD.  The primary
contaminants of concern affecting the soil are metals, including chromium and lead.

The selected remedial action for this site includes excavating 2,500 cubic yards of
contaminated soil with concentrations exceeding a 10-6 risk level and disposing of the
soil offsite; backfilling the excavated areas with clean fill; and monitoring ground
water.  The estimated present worth cost for this remedial action is $338,186, which
includes a present worth O&M cost of $40,186.

PERFORMANCE STANDARDS OR GOALS:  Chemical-specific soil clean-up goals are based on the
exceedance of a 10~6  risk level, including hexavalent chromium 52 mg/kg, nickel
370 mg/kg,  and total chromium 519 mg/kg.

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     respectively.

     No excavation will take place below the water table.  Current
     knowledge of contaminants in the soil and groundwater indicate
     that no excavation below the water table  will be necessary.
     In addition, aquifer characteristics indicate that dewatering
     would not be feasible at this site.

•    Offsite disposal  of excavated  soils at  a Florida  Class I
     Landfill.

•    Groundwater monitoring for up to 5 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  utilizes permanent
solutions  and   alternative  treatment   (or   resource  recovery)
technology  to   the  maximum  extent  practicable  for  this  site.
However, because treatment of the principal threats of the site was
not  found to  be practical,  this remedy does  not  satisfy  the
statutory preference for treatment as a principal element.

Because  this  remedy will  not  result  in .hazardous  substances
remaining onsite  above health-based  levels,  the five-year review
will not apply to this action.
Date  /                      jUGreer C. Tidwell
                            * Regional Administrator

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                       DECLARATION STATEMENT

              RECORD OF DECISION - OPERABT.g TIMTT ONE

                    STANDARD AUTO BUMPER SITE
Site Name  and Location

Standard Auto Bumper  Site
Hialeah, Dade County, Florida

Statement  of Basis  and Purpose

This decision document  presents the selected remedial action for
the Standard Auto Bumper site,  in Hialeah, Dade County, Florida,
which  was  chosen  in accordance  with the  requirements  of  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  Oil  and Hazardous  Substance  Pollution Contingency
Plan.  This decision is based on the administrative record for this
site.   The State  of  Florida,  as  represented  by the Florida
Department of Environmental Regulation  (FDER), has been the support
agency  during  the  Remedial  Investigation and  Feasibility Study
process for the Standard Auto Bumper site.  In accordance with 40
CFR 300.430, as the support agency, FDER has provided input during
this process.    Based upon comments  received  from FDER,  it  is
expected that concurrence  will  be forthcoming;  however, a formal
letter of  concurrence has  not yet been received.

Assessment of the Site

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

Description of the  Selected Remedy

The response action described in this document represents the first
of two planned operable units  for the site.  This remedy addresses
the source of  contamination, the soils.  A prior removal action in
1989 entailed the removal of contaminated waste from an underground
trench and contaminated soils  surrounding  the  Standard Auto Bumper
facility.   Remaining contaminated soils are the existing threat at
the site.   The second operable unit will address groundwater.

The major components of the selected remedy include the  following:

•    Excavation  of  approximately  2500  cubic  yards  of  soils
     contaminated  with  nickel,  total chromium,   or  hexavalent
     chromium equal to or  exceeding 370 ppm,  519 ppm,  or 52 ppm,

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                        TABLE OF CONTENTS

SECTION                  TOPIC

THE DECISION SUMMARY

1.0  Site Description                                         1
     1.1  Surface Features                                    1
2.0  Site History                                             5
3.0  Community Relations Activities and Participation         7
4.0  Scope and Role of Operable Unit One                      8
5.0  Site Characteristics                                     8
     5.1  Surface Water Hydrology                             8
     5.2  Geology                                             9
     5.3  Hydrogeology                                       10
     5.4  Subsurface Features                                12
     5.5   Sampling Results                                  12
          5.5.1   Surface Soil                               13
          5.5.2   Subsurface Soil                            13
          5.5.3   Groundwater                                15
          5.5.4   Surface Water and Sediments                24
6.0  Summary of Site Risks                                   24
     6.1  Chemicals of Concern                               24
     6.2  Exposure Assessment                                26
     6.3  Toxicity Assessment                                27
     6.4  Characterization of Risk                           29
     6.5  Environmental Risks                                33
7.0  Remediation Goals                                       33
8.0  Description of Alternatives                             37
     8.1  Alternative 1 - No Action                          37
     8.2  Alternative 2 - Excavation and Offsite Disposal    37
     8.3  Alternative 3 - Excavation, Onsite Soil Washing,
               and Onsite Replacement                        38
     8.4  Alternative 4 - Excavation, Stabilization/
               Solidification, and Onsite Disposal           41
9.0 Summary of Comparative Analysis of Alternatives          43
10.0 Selected Remedy                                         48
11.0 Statutory Determinations                                50
12.0 Documentation of Significant Changes                    52

Appendix A     Responsiveness Summary
Appendix B     Risk Assessment Exposure Assumptions and Parameters
Appendix C     DERM Soil Disposal Criteria

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                          LIST OF TABLES

NUMBER                   TABLE                               PAGE


  1       Soil Sampling Data Summary                          16

  2       Toxicity Characteristic Leaching Procedure Levels   18

  3       Contaminant Data for the Standard Auto Bumper Site  26

  4       Intake Factors                                      28

  5       Carcinogenic Toxicity Values for
          Contaminants of Concern in Surface Soil             30

  6       Noncarcinogenic Toxicity Values for
          Contaminants of Concern in Surface Soil             31

  7       Hazard Indices for Nonearcinogens in Surface Soil   32

  8       Carcinogenic Risk Levels for Surface Soils          34

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                         LIST OF FIGURES

NUMBER              FIGURE                                  PAGE


  1       Dade County Location Hap                            2

  2       Topographic Location Map       -                     3

  3       Site Base Map                                       4

  4       Shallow Aquifers in Southern Florida               11

  5       Concentrations of Selected Inorganic Analytes
          Detected in Surface Soil During the
          Phase I RI                                         14

  6       Concentrations of Selected Inorganic Analytes
          Detected in Subsurface Soil
          During the Phase 1 RI                              17

  7       Concentrations of Selected Inorganic Analytes
          Detected in Groundwater, April 1991                19

  8       Concentrations of Selected Inorganic Analytes
          Detected in Groundwater From
          Temporary Monitoring Wells
          During the Phase 1 RI                              21

  9       Concentrations of Selected Inorganic Analytes
          Detected in Groundwater From
          Permanent Monitoring Wells
          During the Phase 1 RI                              22

 10       Concentrations of Selected Inorganic Analytes
          Detected in Groundwater From
          Permanent Monitoring Wells
          During the Phase 2 RI                              23

 11       Soil Above Cleanup Goals                           39

 12       Soil Washing System                                40

 13       Stabilization/Solidification                       42
                               iii

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                           DECISION SUMMARY

1.0  SITE DESCRIPTION

The Standard Auto Bumper site is  located in an industrialized area
of  northeast  Dade  County,  Florida at   2500  West  3rd  Court,
approximately six miles  northwest  of downtown Miami and includes
areas where the  contamination has  come to be located (Figure 1).
Standard Auto  Bumper  is an  active  chromium and  nickel plating
facility which has operated at the same Hialeah address since 1959.
The  property  area  is  approximately  42,000  square  feet  and
geographically  located  at  25°50'40"  N   latitude,  80°17'15"  W
longitude.  The site is  shown in Figure 2 on the Hialeah, Florida
USGS 7.5 minute topographic quadrangle map.

Standard Auto  is bordered on the  north by Quality Manufacturing
Products, Inc.  and World Metals; on the east,  across West  3rd Court
by Nela Junk Yard; on the south by Fernandez Transport Corporation;
and on  the  west, across the  railroad track,  by the Gilda Bakery
(Figure 3).  The Red Road Canal is located approximately 300 feet
west  of the  site running  parallel to  West 3rd  Court  and  the
railroad.

Hialeah is an incorporated city that consists of heavy development
with mixed  zoning.    The city has an approximate  population of
188,000 people and a strong manufacturing, wholesale, service and
retail  industry.   Twenty percent  of .the property within a mile
radius  of  the  site is  utilized  for  commercial  and  industrial
purposes,  sixty percent is  residential,  and  the .remaining  20
percent  is  used for  recreational  parks and  schools.    It  is
estimated that 11,000 people  live or work within a mile radius of
the site.

1.1 Surface Features

The ground  surface at  the Standard Auto Bumper  site  is almost
entirely flat and unpaved,  ranging between 6.5  feet and 9.5 feet
above the National Geodetic Vertical Datum of 1929 (NGVD29).  The
ground surface elevation on-site is between 7.5 feet above NGVD29
on the southern part of  the site and 6.8 feet above NGVD29 on the
northern portion of the site.  The  ground  surface elevation on the
neighboring property to the west  is between 9.0  and 9.5 feet above
NGVD29 and the  ground surface elevation across West 3rd Court is
approximately 6.7 feet above  NGVD29.

The area north of the  facility building  has two open excavations
where removal  activities of  contaminated  soil  occurred in 1989.
The open excavations are deeper  on the westernmost sides and are
approximately 2.5 to 3  feet in depth.  The site features consist of
a one story concrete block  structure (approximately 19,150 square
feet), two concrete holding tanks, a concrete and  an asphalt slab
and numerous holding and drying racks for  bumpers and other chrome

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&EPA
DADE COUNTY LOCATION MAI
STANDARD AUTO BUMP!1
   HIALEAH, FLORIDA


      Figure 1

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              1 S   IV-
STANDARD AUTO 3UMPER SITE
                         APPROXIMATE SCALE
                       2000          0    1000   2000
                     t
                                                                            15
        Figure 2

TOPOGRAPHIC LOCATION MAP
-jtERA
( IN FEET )
1 incn - 2000ft.
^lAINUMKU AUIU DU.V.ri.-
HI ALE AH, FLCRiCA
SOURCE: USCS MIAL£A*. H-CXCO*
7.s MNuir sones OJAMAMCLE. -:M

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  GRAPHIC SCALE
           0      90
    SITE BASE MAP
STANDARD AUTO BUMPER /
   HIALEAH. FLORIDA
         y*y kU^ SQURC& U & tft* V
         MUM. PHOTO Ijjo/ft. tMfll
               IflCATtD MXAHM ID
         MUMUMT sumrr oi/n/n

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 items.     Other  one  story  concrete   block  structures   housing
 commercial/industrial businesses occupy the  immediate  surrounding
 area.

 The Red Road canal is the nearest body of surface water to the site
 and is  located to the west at a distance of approximately 300 feet.
 Based on the elevations obtained from the  vertical  control survey
 conducted during  the RIf  the  Florida  East  Coast  Railway  (FEC)
 roadbed acts as an  artificial  dike that prevents any  westward
 migration of surface water from the site.

 2.0 SITE HISTORY

 Standard Auto  Bumper  Corporation  has  owned  the  electroplating
 portion of the  site since 1959.   Prior  to  1959,  this property was
 divided into 2   facilities:   located on the  southern half of the
 site was a slaughterhouse, and on the northern half of the  property
 was a furnace/smelting company  (Yacco,  1991).   In 1959  Standard
 Auto Bumper began chromium  and  nickel  plating operations on the
 site.   Prior to installation of a  treatment system in 1972, the
 wastewater from Standard Auto Bumper's electroplating and stripping
 process  was discharged to a drainage ditch/swale area west of the
 facility.   Since 1972,  a wastewater treatment system to  convert
 hexavalent chromium  to  insoluble   trivalent  chromium  has been
 operational.  Approximately 5,760 gallons of wastewater per day can
 be  processed, according to Standard Auto Bumper.  Between  1972 and
 1979 the effluent  from the treatment system was discharged to an
 underground, slab-covered drainage  trench  located adjacent to the
 treatment tanks.  In 1979, use of this trench  was  discontinued when
 the Hialeah sewer  system became the  receptor  for the  effluent
 discharge.  Numerous  improper discharges of treated and untreated
 wastes   to  the  ground  have  been documented  by Dade County
 authorities.

 A Metropolitan  Dade County Department  of Environmental Resources
 Management  (DERM) inspector  observed effluent being discharged to
 a soakage trench in the back alley on May 10,  1977.  The owner was
 ordered  to correct the violations.  However,  on November 16,  1981,
 a county inspector observed that metal  cleaning waste was being
 discharged  into an  on-site drain.    On June  4, 1982,  open and
 leaking  drums and discharges of  plating liquids were found on the
 ground.  A pipe was also discovered  leading from  the facility into
 a ditch  and the  ditch water sample  contained 160 mg/1 of  nickel,
 160 mg/1 of chromium,  and 7.52 mg/1  of copper.

A county Waste Dumping Citation was  also issued to the  facility on
 June 4,  1982, and subsequent inspections found the facility had not
 ceased illegal discharges.  A Final  Notice  of Violation was issued
 on October 5,  1983.  A county inspector,  on  March  3,  1985,  observed
 evidence of  untreated wastewater discharges  into  the  city  sewer
 system.

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On August 14, 1985 soil and groundwater samples collected onsite by
the  EPA contained  numerous contaminants  associated with metal
plating activities.  On December 3, 1985, waste samples collected
by county officials contained concentrations of total cadmium and
nickel which exceeded county groundwater quality  standards.   On
September 10,  1986, county officials  observed illegal discharges
and an overflow pipe leading offsite.

An Expanded Site Investigation (ESI) was  conducted  at the Standard
Auto Bumper  site  in March 1987, by the  U.S.  EPA Region IV Field
Investigation  Team  (FIT).   Numerous  soil and groundwater samples
were collected at  the site as part of the  ESI,  and were used to
document the Hazard Ranking System (HRS) package data and provide
preliminary data for the Remedial Investigation/Feasibility Study
(RI/FS).

The ESI samples were analyzed for the parameters in the Hazardous
Substance List.   This list, which was a precursor to the Target
Compound  List and Target  Analyte  List,   included organic  and
inorganic chemicals.  Elevated concentrations  of heavy metals were
found in the former disposal areas and  other areas of interest.
Similar contaminants were identified in the  soils, groundwater, and
waste effluent samples, indicating that  the source of groundwater
contamination  is  soil leachate from  the discharge areas.    The
detected   organic   compounds   included  polynuclear   aromatic
hydrocarbons  (FAHs)  and pesticides.   PAHs are  associated  with
creosote products that can  be  found  in railroad ties and asphalt
paving.  Pesticides are not related to the electroplating process
and were not attributed to  the  Standard Auto site.  No groundwater
samples contained  concentrations  of any organic  compounds above
Federal or  State drinking  water  standards.   The  Standard  Auto
Bumper site  was  proposed for inclusion  to  the National Priority
List (NPL) in June,  1988 and became  finalized in October, 1989,
based on the HRS Package (1987).

In 1989 and 1990,  Standard  Auto Bumper conducted a  soil removal on
the property under an Administrative Order  (AO) with the EPA.
Under the removal action the PRP was required  to excavate the soil
and sludge in the bottom of the slab-covered trench. The excavated
material was  sent to the  Chemical Waste Management  facility in
Emelle, Alabama for disposal.  Soils were also excavated from the
drainage  ditch  and  south areas  of  the  site  to a  depth  of
approximately 6 feet.   These soils were not deemed  hazardous waste
and were sent to the South Bade County Landfill. The PRP's removal
activities were conducted under the oversight of the EPA.

The AO for the removal specified soil  clean-up levels based on the
Extraction Procedure (EP) Toxicity test method for the contaminants
at the site.  The extraction levels included cadmium at 0.01 mg/kg,
chromium at  0.05 mg/kg,  copper  at  0.4 mg/kg,  lead at 0.05 mg/kg,
nickel at 0.15 mg/kg, and cyanide at nondetectable levels.

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On February  28,  1990, a  second Administrative Order was  signed
between  Standard Auto Bumper and  EPA to  implement the  RI/FS.
However, in  February 1991, Standard Auto  Bumper elected  not  to
continue performing the RI/FS, and  EPA, Region IV,  took over the
RI/FS activities. Standard Auto Bumper had not  conducted any field
studies at the time EPA took over the remedial activities.

The EPA conducted the preliminary RI in April,  1991.  Groundwater
samples were collected from existing monitoring wells at the site
to  determine the  current  conditions  of  the  groundwater.    In
addition, sediment samples were collected from the Red Road Canal
to provide information on the site's impact on the canal.

The first phase of the RI took place in 1991  and 1992 and consisted
of the  majority  of  the field activities (soil sampling, surface
water sampling, monitoring well installation, and additional ground
water sampling).  Metals such as  chromium,  nickel,  and lead were
found in the samples.  During Phase 2 in May 1992, two additional
monitoring wells  were installed and the third round of ground water
samples were  collected from all  of the wells.   Analytical  data
indicated that,  between  successive groundwater  sampling events,
metal concentrations in the groundwater decreased considerably.  A
significant  portion of the apparent  decrease,  however,  may  be
attributed to improved, state-of-the-art, sampling techniques that
have been able to effectively eliminate turbidity.

EPA completed a Baseline Risk Assessment for the site in July 1992.
The assessment evaluated  the current  and potential future risks
posed by the  contamination  at the site under  the no-action scenario
for current  and  future uses of the site.   The Feasibility Study
(FS) Report was prepared by the EPA and finalized in August 1992.
The report evaluated  a range  of  remedial alternatives that could
address  the  contaminated  soil  at  the site.   The alternatives
included no-action,  removal, and treatment.

3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION

Prior to the RI/FS  the EPA conducted an Information Availability
session to introduce the  Super fund process and the  site  to the
community, explain the activities planned for the site, and answer
any questions.   The meeting, held on January  10, 1991 in a local
school,  was  publicized  in  local  papers   and by  door to  door
canvassing in the community.  At the completion of the RI/FS, the
RI/FS Report and Proposed  Plan  for  the site were released to the
public in August 1992. These  documents were made available to the
public  in both  the  Administrative  Record and an information
repository maintained at the  EPA Records Center in Region IV and
the John F.  Kennedy Memorial Library  in Hialeah.   The notice of
availability for the documents was published in the Miami Herald on
August 13,  1992,  and the Spanish newspaper,  Diario Las Americas, on
August 7, 1992.

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The Proposed Plan was  sent to over 400 people  in the community,
government, and  media.   A public comment  period was  held from
August 7 to September 6,  1992.  A public meeting, announced in the
public  notices  and in the Proposed Plan,  was  held in  a nearby
school auditorium on August 18, 1992.   The purpose of the meeting
was to  present the  proposed plan and  answer questions.   Three
citizens attended the public meeting.   A response to the comments
received  during  this  period is  included in the Responsiveness
Summary, which is part of this Record of Decision (Appendix A).

This decision document presents the selected remedial action for
operable unit one of the Standard Auto  Bumper Superfund Site, chose
in accordance with CERCLA,  as  amended by  SARA.   The decision for
this site is based on the Administrative Record.

4.0 SCOPE AND ROLE OF OPERABLE UNIT ONE

As with many Superfund sites, studying and addressing contaminated
media in the most efficient manner can be a difficult endeavor, due
to  complex characteristics of each  site.    As  a result,  EPA
organized the site into  two operable  units  (OUs): one to address
contaminant  source  areas  (OU  #1)  and  the other  to  evaluate
groundwater conditions (OU #2).  The remedy presented in this ROD
addresses the first operable unit,  the  contaminated soils at the
site.

This  soil  poses  a  principal  threat to  human  health  and  the
environment due  to  ingestion  of  contaminated  surface  soils by
children of potential future residents and the soil contamination's
impact on the groundwater.  The cleanup objectives for this OU are
to prevent current or future exposure to the  soil contaminated with
nickel and  chromium through treatment and/or containment, and to
reduce  the migration  of  these contaminants from  the  soil to
groundwater.

The second  operable  unit will address the  groundwater while the
remedial  action  presented in this ROD  is performed.   Additional
groundwater sampling will be necessary befere a final decision can
be made about the need  for and type of  cleanup alternative for  this
media.    A decision  regarding OU f2  will  be  presented in  a
subsequent ROD.

5.0 SITE CHARACTERISTICS

5«1 Surface Water Hv*^Toloqv

The location of surface water in Dade County  is almost completely
limited  to  the intricate  canal network that was  dug to support
farming,  flood control and urbanization.   Drainage from the  site
during rainfall events appears unlikely due to the topographic  high
of the limestone gravel roadbed of the Florida East Coast  Railway,
which acts as a barrier and the porous nature of the well drained

                                8

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sandy soils in the area.  Surface water in the canals is in direct
hydraulic  connection  with the  Biscayne  Aquifer,  however/  the
potential  for contamination from the Standard Auto site to impact
the surface water in the Red Road canal by means of an overland or
surface water route is  remote.

The canal  system was started in the early 1900's as a way to drain
lands for  farming along the south rim of Lake Okeechobee.  Later,
as a result of roads that were built across the area, water became
diked and  impounded and  subsequent canals were  built  for flood
control to intercept overland flow of water and divert some of the
water to the southeastern coast of Florida. Because of this direct
connection to  the ocean,  sea water intrusion became  a problem.
Dam-like structures or water  control  stations  with  gates to hold
back or release water  in the  canals were built as a way to guard
against flooding and sea water intrusion.  During  wet times of the
year, the  gates  are opened allowing water to  flow  in the canals
thus lowing ground water levels  and preventing flooding.   At the
end of the rainy  season and during the dry months/  the gates are
closed, allowing water  levels to be maintained high enough in the
canals to  protect against sea water intrusion.

The hydraulic connection between the Biscayne Aquifer and the canal
system is evident from the variation in  canal elevations depending
on precipitation levels.  Most of  the canal water  level elevations
are higher in  the area of  the site than  the  surrounding ground
water level elevations  when there is less than normal precipitation
and the canal gates at water control stations  are closed to prevent
the movement  of  seawater up  the  canals.   The   reverse  of  this
situation  (i.e. canal  gates open to release  storm  water runoff)
results in lower canal water level  elevations   relative  to  the
surrounding ground water level elevations.

5.2 Geology

In south   Florida,  the upper  3,00.0 feet  of rocks are composed
chiefly of limestone,  dolomite,  sand,  clay,  marl,  and  shells.
Geologically, the Biscayne Aquifer is composed of soils of Holocene
age and rock ranging in age from Pleistocene through Pliocene.  The
1987 ESI at the Standard Auto site documented mostly unconsolidated
surficial deposits consisting of  calcareous sands  and gravels to a
depth of approximately 28 feet below land surface  and quartz sands
to a  depth of  approximately  48  feet.   A  harder,  consolidated
bedrock  unit  was  reportedly encountered below the  surficial
deposits and was described as cavity-riddled,  fossiliferous, marine
limestone.   At  the site, the Biscayne Aquifer extends to  a depth of
approximately 110 feet  below sea level.

Solution cavities occupy a significant volume of  the limestone in
the Biscayne  Aquifer,  causing it  to  have  high horizontal  and
vertical permeabilities.  The lower part of the oolitic limestone
is also cavity  riddled  and  is  identified  by  the presence  of

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bryozoans.   A  hard cavernous  limestone underlies  the bryozoan
layer.    Because  of  the  extremely  high  permeability of  this
limestone, all  large capacity wells are completed in this part of
the aquifer, generally 40 to 100  feet below the land surface.
 5.3
 The uppermost hydrogeological water bearing unit in the study area
 is the Biscayne Aquifer.  The Biscayne Aquifer is the major source
 of all the municipal water for the residents of the southeast coast
 of Florida from Boca Raton southward and is  composed of limestone,
 sandstone, and sand.

 The  major aquifers  in south Florida are  composed primarily of
 limestone  and supply  varying  yields of  potable and  non-potable
 brackish water for municipal and irrigation water use  in southern
 Florida.  The aquifers, ranging from highest to lowest  yield, are:
 the Biscayne Aquifer of southeast Florida,  the  Shallow Aquifer of
 South  West Florida, and  the Coastal  Aquifer of  Palm Beach and
 Martin Counties  (Figure 4).  Underlying these aquifers is a thick
 confining layer composed of relatively impermeable beds of clay and
 marl which overlie the Floridan aquifer.

 The Floridan Aquifer in southern Florida  is composed of permeable
 limestone and contains non-potable brackish  water. The  impermeable
 beds  separating  the  shallow  aquifers and the  deeper Floridan
 aquifer  shield  against the  upward intrusion  of brackish water.
 However, there  is no shield against  the  lateral encroachment of
 seawater .

 Recharge to the  Biscayne  Aquifer  is primarily by local rainfall.
 Infiltration is rapid in the areas covered by sand, or where soil
 is absent.  In the  site vicinity,  the soil  type consists of fine
 quartz sand.  Discharge is by evapotranspiration, canal drainage,
 coastal seepage, and pumping.

 Transmissivity (T) of  the Biscayne Aquifer ranges  from 5.4 X  10*
 ftVday (581 cmvsec) where the  aquifer is mostly sand  to greater
 than 1.6 X 106 ftVday (17,200 cmVsec) in the limestone-rich areas.
 During the ESI conducted in 1987, site specific values of hydraulic
 conductivity  (K)  were determined to  range between  42.8  ft/day
 (0.0151 cm/sec)  to 102 ft/day (0.036 cm/sec) or an average of 62.6
 ft/day  (0.0221  cm/sec).   Using  the  relationship T=Kb,  a  site
 specific  value   for  the   transmissivity  of  the  unconsolidated
calcareous sands and gravels and quartz sand zone can be estimated:
T = 62.6 ft/day X 48 ft = 3000  ftVday  (32.3 cmVsec).  This site
 specific value for the transmissivity of the  unconsolidated zone is
an order of magnitude lower than the published value for the sandy
portion of the Biscayne Aquifer.

Regional flow of ground water in the Biscayne Aquifer of southeast
Florida is seaward.  Locally, however, the direction and rate of

                                10

-------
            LEGEND
    r BISCATW AQUIfW. M1O1
 SHALLOW AQUIFER OF SOUTH WEST FLORIDA.
 MODERATE TO HIGH YIELD
 COASTAL AOUIFTR or PALM BEACH AMD
 MARTIN COUNTIES. MODERATE YIELD

- LOCAL. DISCONTINUOUS. WATERBEARING
 MATERIAL, LOW YIELD
—«—- LINE OF EQUAL DEPTH OF BASE OF AQUIFER.
      FEET BELOW SEA LEVEL (NCVC29)
      (EOUIOISTANCC - 20 FEET - 6.1 METRES)
    FIGURE 4

SHALLOW  AQUIFERS
         IN
SOUTHERN  FLORIDA
  &EPA
                                                             STANDARD AUTO BUMPER

                                                               HIALEAH, FLORIDA
                                                                    APPROXIMATE SCALE
                                                                  23           0     U.I     25
                                                                      (IN MILES)

                                                                    1  In. • 25 mil«s
                                                                       (Uo«*M
                                                                              Ktoto «n« otn
                                                                              tea_ «»•* 3)
                                                                                    >«. 1*73. ix>s»

-------
flow may be significantly  influenced  by the direct surface water
connection of the canal system and/or  by pumping from well fields.

Variations in the  direction and rate of  flow  of  groundwater was
documented during  the  ESI  and RI.   During  the ESI in 1987, site
specific groundwater elevations indicated  shallow groundwater flow
towards the west.  Groundwater elevations during the preliminary RI
in April 199 I/  also indicated a westward trend in groundwater flow
for shallow groundwater monitoring wells.  The rate of groundwater
movement at this time was an estimated 88 feet per year.

The rate of groundwater movement differed greatly in 199 1, compared
to   previous   observations.     During   the  Phase   1   RI   in
January/February 1991,  groundwater  flow in the shallow aquifer was
southeasterly and the rate of flow was approximately  1.7 feet per
day.  During the Phase 2 RI in May 1992, two trends were observed
in the aquifer.  Close to  the site,  shallow groundwater movement
was  towards  the site,  while  farther from  the  site,  groundwater
movement was to the southwest.

5.4 SnhgiiT-fa.ee
In the northwest corner of the site there is an unused underground
storage tank.  Standard Auto Bumper had plans to remove the tank,
however, no action has  been taken to date.   A gas line extends from
the east side  to the west of  the  site on the north  edge of the
property.  No  other  underground  structures are  known to exist at
the site.
The scope of the RI at the Standard Auto Bumper site included field
studies  on the  soils  and  the groundwater.   Additionally,  the
sediment  and  the  surface  water  from  Red  Road  Canal  were
investigated.  Soils were analyzed for the full Target Analyte List
(TAL).  The investigation focused on inorganic contaminants for the
following reasons.  The primary reason for the reduced sample and
analysis plan to include only inorganic chemicals was based on the
extensive sampling efforts of the ESI.  During the ESI, a  variety
of organic  and inorganic contaminants were  found in  the former
disposal areas and other areas  of  interest.   Among these  organic
compounds were some polynuclear aromatic hydrocarbons (PAHs) and
pesticides.  PAHs are associated with creosote products that can be
found  in railroad ties and  asphalt paving.   Pesticides  are not
related  to  the  electroplating  process  and are  difficult  to
attribute to the Standard Auto site.

Another  reason for the reduced analysis is that organic compounds
were not detected in any groundwater samples  from monitoring wells
at levels above Federal  or  State drinking water standards during
the ESI or the RI.  However,  trichloroethene  slightly exceeded the
Maximum  Contaminant  Level in  samples from  an onsite industrial

                                12

-------
well.  Full TAL/TCL analyses will be conducted at the completion of
cleanup to demonstrate that the site is clean.

Three areas were identified in the Remedial Investigation as having
the highest concentrations of metals in soils relative  to the other
areas.  These areas correspond to  the former drainfield area north
of the  facility building, the loading and  unloading  area at the
southeastern portion of the site and near the southwest corner of
the site.   Concentrations of chromium and  nickel  in  these areas
were one to two orders of magnitude higher than the concentrations
found at most of the other soil sample locations.

5.5.1 Surface Soil

Nineteen  metals and  cyanide  were detected in the surface  soil
samples.  Aluminum, barium, calcium, chromium, copper, iron, lead,
magnesium,  manganese,  mercury, nickel, strontium,  titanium,  and
zinc were detected  in nearly  every  surface soil sample.   Surface
soils were collected from the surface to a  depth  of .8  inches at 17
locations throughout the site.

The  chromium concentrations  ranged  between  2300  mg/kg  and  9.4
mg/kg.  Table 1  presents information on the ranges of concentration
of target contaminants.  Concentrations of  chromium in the surface
soil samples were highest near the former drainfield area north of
the  facility building,  near  the  southwest corner  of the  site
property  and   near  the  loading  and  unloading  areas  at  the
southeastern portion of the site (Figure 5).

The three highest concentrations of nickel (4200 mg/kg, 3800 mg/kg,
and  1900  mg/kg) were identified in  areas corresponding  to  the
former drainfield area north of the facility building, the loading
and unloading area  at the southeastern portion  of  the  site,  and
near the southwest corner of the site property, respectively.  The
nickel concentrations ranged from 4200 mg/kg to 8.9 mg/kg.

Copper was detected at concentrations ranging  from 16  mg/kg to 600
mg/kg.  The highest  copper detections were at the same  locations as
the highest chromium and nickel concentrations.

Detectable lead concentrations ranged from 7.9 mg/kg to 160 mg/kg.

5.5.2 Subsurface Soil

Nineteen metals and cyanide were  detected in  the subsurface soil
samples from depths ranging from the 11 to  18 inch interval to the
38 to  43  inch  interval.   Most  of the  subsurface samples  were
obtained from 2.5 to 3 feet below the surface.  The nineteen metals
are:  aluminum,   antimony,  arsenic,  barium,  calcium,  chromium,
copper, iron, lead,  magnesium,  manganese, mercury, nickel, silver,
strontium, tin, titanium, vanadium,  and zinc.  A summary of


                               13

-------
««•"*•
                                                                                                                                FIGURE y
                                                                                                                        CONCENTRATIONS OF  SELECTED
                                                                                                                       INORGANIC ANAIYIES  OEHCTIO
                                                                                                                        INSIJWACE SOU  DURING  THt
                                                                                                                         PHASf t  «l OV91    V92)
                                                                                                                          SfANUAUl) AUIO HUMPIK
                                                                                                                             HIAII AM.  MOKIDA
                                                                                                                                   B*^ ""' »*«u us IP*, ini.
                                                                                                                                   MMM MlOII) IJ/VU/M ANII
                                                                                                                                   HH»ruM^ inono miAiM  in

-------
 subsurface soil data for the Standard Auto Bumper site is presented
 in  Table 1.   Figure  6  presents the concentrations  of selected
 metals  for each  subsurface soil  sample location.

 The  maximum concentrations of thirteen  of  the nineteen detected
 metals  were  found in one subsurface soil sample obtained from an
 area offsite, near the northwest property corner.  Of both surface
 and  subsurface soil samples,  the maximum  concentrations for eleven
 metal analytes were detected in  this subsurface soil sample.

 Chromium  was found  detected in  concentrations  as  high  as 9100
 mg/kg,  1600  mg/kg, 690  mg/kg,  360  mg/kg, and 200  mg/kg.   These
 areas correspond to the  southwest corner of the site property and
 near the  former  drainfield area  north of the facility building.

 Relatively  high  concentrations  (340 mg/kgf  170 mg/kg,  and 140
 mg/kg)  of copper were  identified in subsurface soil samples which
 are  located near the southwest corner of the site  property and near
 the  loading  and  unloading area at the southeastern portion of the
 site. Elevated concentrations of nickel,  2300 mg/kg  and 970 mg/kg,
 are  found near the southwest corner of the site  property.  Slightly
 elevated  nickel  concentrations  were  found  near the  loading and
 unloading area at the  southeastern portion of the site.

 Aside from the maximum lead  concentration found in  one sample of
 520  mg/kg,  the  lead  concentration ranged  from  99  mg/kg  to 2.9
mg/kg.

As  part  of  the  RI/FS, the  Toxicity  Characteristic  Leaching
 Procedure  (TCLP) test was performed  on  the soil from  the site.
 Three soil samples were collected from three locations, two surface
 samples and one  subsurface sample.  These locations were in areas
 containing the highest concentrations of the contaminants.

The soil did not  exceed TCLP regulatory levels as  shown in Table 2,
 indicating there are no RCRA hazardous wastes at the  site. However,
the  TCLP  results  do   indicate  contaminants  can  leach,  thus
contributing to  groundwater contamination.

 5.5.3 Groundwater

Preliminary  RI.     During the  preliminary RI  in April  1991,
groundwater samples were collected from seven existing monitoring
wells and the industrial well.  All samples were analyzed for the
complete  TAL  and Target  Compound  List (TCL).    A summary  of
 significant levels of selected inorganic  chemicals detected  in the
groundwater during this  sampling event is presented  in Figure 7.

The  groundwater  samples contained  a variety of metals  and some
organic compounds.   The most pervasive groundwater contamination
was  detected  in  the shallow  groundwater  monitoring well samples,
particularly from the location directly downgradient  from the site.

                                15

-------
                                    TABLE 1
               STANDARD AUTO BUMPER SOIL SAMPLING DATA SUMMARY

                                    (mg/kg)

                                  SUBSURFACE
Contaminant
Concentration   Number
    Range      Detected
Concentrat ion
  Average
  Total
Number of   Background
Samples   Concentration
Chromium
Copper
Lead
Nickel
2.7
4.0U -
l.OU -
2.0U -
9100
4700
520
9700
15
13
16
15
STANDARD AUTO BUMPER
719.2
327.95
55.73
948.41
17
17
17
17
2.7
l.OU
l.OU
2.0U
SOIL SAMPLING SUMMARY
(mg/kg)
SURFACE

Contaminant
Chromium
Copper
Nickel
Lead
Cyanide
Zinc


Concent rat ion
Range
9.4
10U
8.9
7.9
0.21U -
10U
2300
600
4200
160
12
400

Number
Detected
14
14
15
17
4
16

Concent rat ion
Average
290.28
118.08
879.22
74.49
1.37
131.11
Total
Number of
Samples
17
17
17
17
17
17
4
Background
Concentration
10U
10U
20U
7.9
0.23U
10U
U - Material was analyzed for but not detected.
    The number is the minimum quantification limit.

Source:  Remedial Investigation Report for the Standard Auto Bumper Site,
         EPA, 1992
                                      16

-------
                                       CHROMIUM
                                       COPPCR
                                       !IAO
                                       MCKCl
                                       CYAMOC
                                                                CHROMIUM
                                                                COPPER
                                                                If AD
                                                                MCKa
                                                                CYAWDC
CHROMIUM
COPPER
UAD
MCKCl
CYAMOC
                                   CHROMIUM
                                   COPPER
                                   11*0
                                   MCKCl
                                   CYAMOC
                                         RAM AS BROTHERS
                                           AUIO REPAIR
 CHROMIUM
 COP«H
 LEAD
 mom.
 CYAMOC
                                            CHROMIUM
                                            COPPER
                                            UAO
                                                 CHROMIUM
                                                 COPPCR
                                                 HAD
                                                 MCHCI.
                                                 CYANUC
CHROMIUM
COPPER    31
UAD      47
MCKCL     310
CYAMDC
SIANOAKD
  AUIO
 BUWt R
CHROMMM   20
COPPER    37
UAD      ••
MCKa     100
CYAMOC    0.97
                                                                                    A - SOII SAMI'll IUCAIIUN
                                CHROMIUM
                                COPPCR
                                UAO       4.9
                                MCKfl      70
                                CYANXJC
                       CHROMUM   l»
                       COPPCR     7S
                       UAO       n
                       NICKCl      32O
                       CYANOC
                                                                                 AU CONL1NINAIIONS IN  KG/KG
    CHROMUM   690
    COPPER    340
    UAD      SO
    MCKEL     230C
    CYAMOC    M
                                                                                        GRAPHIC  SCALt
                                                                                                  0       M)
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a                                          NAN SPORT
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                                                                                                     OK  SHfClfl)
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                                                                                     IIIAII All.  II OKIDA
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                                                                                                     Alii) kll A
                                                                                           IIM'AINM!, ll» AHI) kll All*  III
                                                                                           UUiMiAHl MOV* » m/m/»l

-------


TABLE 2


TOXICITY CHARACTERISTIC LEACHING PROCEDURE RESULTS
(M6/L)
SAMPLE
1
2
3
Average
Regulatory
Levels
COPPER CHROMIUM
1.73
1.55
1.85
1.71
—
no regulatory level
0.022
0.015
0.021
0.019
5.0
has been
NICKEL
9.76
9.61
9.33
9.57
—
established
LEAD
0.058
0.038
0.031
0.042
5.0

18

-------
ZCCC3IAT

                                                                                                                      LLONQ
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                                                                                                             - INDUSIRIAI Will
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-------
MCLs  (Maximum  Contaminant Levels)  were  exceeded  for  arsenic,
chromium,  iron,  lead  and manganese  in  most  of  the  samples.
Trichloroethene, with a MCL of 5 ug/1, was detected at an estimated
concentration  of 7  ug/1  in  the industrial  well onsite.   This
chemical will be sampled further during OU #2 for groundwater.

Phase One.  During phase one of the RI in December 1991 and January
to  February 1992 temporary wells  were installed.   Existing and
newly installed shallow permanent monitoring wells were sampled and
analyzed  for the  complete TAL.    One sample  was  analyzed for
purgeable organic compounds in addition to the TAL.

Groundwater concentrations for chromium and nickel were highest in
temporary  monitoring  wells  near  the  southern  site  property
boundary.    The  most  pervasive groundwater contamination was
detected in the shallow permanent monitoring well located west and
directly adjacent and downgradient  from the former drainfield area
north  of  the facility  building (groundwater  sampling  data from
temporary and permanent monitoring wells is depicted in Figures 8
and  9,  respectively).     The  sample  collected  from  this  area
contained the highest concentrations of chromium, copper, nickel,
and zinc.

The samples collected from the deeper monitoring wells (Figure 9)
and the  onsite  industrial well did  not contain  any  detectable
chromium, nickel, or copper.  Overall the deeper monitoring wells
and the  onsite  industrial well yielded  samples which  had low
concentrations  of the metals  compared  to  the shallow monitoring
wells.

The ground  water samples  from six  shallow monitoring  wells were
analyzed for hexavalent chromium.   Hexavalent chromium is a more
toxic  form  of  the metal than trivalent chromium.   No hexavalent
chromium was detected in any of the samples.

Phase one of  the RI detected groundwater  samples with inorganic
concentrations which exceed drinking water standards.

Phase Two.   Phase 2  RI field activities were  conducted  in May,
1992.    The purpose  of  this  groundwater  sampling  event was  to
confirm the Phase 1 results and/or identify the necessity for any
additional groundwater  sampling.  Two  deep monitoring wells were
installed and sampled for the  complete  TAL.  The  13 existing wells
were also  sampled and  analyzed for  the  same parameters.   The
concentrations  of selected inorganic analytes  identified in the
groundwater samples are presented in Figure 10.

Chromium,  copper,  lead   and  zinc  were  not  detected  in  any
groundwater samples  from  the  shallow  monitoring  wells.   Nickel
exceeded the MCL in only one well.

The results  from the  newly installed  monitoring wells  did not

                                20

-------
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-------
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-------
appear  to coincide  with previous  sampling  results or  with the
current groundwater data. Chromium, lead, and nickel were detected
only  in  the  two new deep monitoring wells and> not in any of the
other deep wells.  The concentration of these three metals were at
low  concentrations slightly  above  their detection limits.   The
chromium concentration was slightly above the State drinking water
standard.  The concentration of aluminum found in these  two samples
was  two  orders of magnitude  higher than was  found in any other
sample.   Based  on these  results,  and  the   sample clarity with
respect to that obtained in all other  samples  it appears that the
samples  may  have  been  collected prior  to  complete development.
Another   sampling  event  will   determine   more   representative
groundwater conditions.

The  results  from  the  third  round  of  sampling  since  April 1991
indicate  significantly  lower  concentrations  for most of  the
inorganics detected when compared to the results from the second
round of sampling.  The analytical results of the second  and third
round of groundwater sampling have  indicated  lower concentrations
of inorganic  contamination than  the  first  round  of   groundwater
sampling.  The RI  Report concluded  that the particles  responsible
for elevated levels of metals  such as chromium and nickel, found in
early sampling events, had been removed as a  result of additional
well  development  conducted  during the  RI.    The report  also
determined  that   the   last   sampling  results   are   the  most
representative of  groundwater quality  and that nickel may be the
only  contaminant  of concern  at  the  Standard Auto Bumper site.
Additional field work will be  performed to confirm the condition of
the groundwater during operable unit #2.

5.5.4 Surface Water and  Sediment

Three sediment samples and surface water samples  were collected in
Red Road Canal and analyzed for TCL/TAL and TAL, respectively.  The
sediment  samples   contained metals  which did  not appear  to  be
related  to  the site,  with the  exception of lead at  a maximum
concentration of  120 mg/kg.    The surface water samples from the
same  location contained  no  detectable  chromium, copper, cadmium,
nickel, lead, arsenic, or cyanide.

The RI concluded  that surface water data could not be correlated
with  the soil  and  groundwater   data  for the  site.    Also  the
upgradient surface water concentrations  were nearly identical to
the downgradient concentrations.

6.0 SUMMARY OF SITE RISKS

As part of the RI/FS, EPA prepared a Baseline Risk Assessment for
the Standard Auto Bumper site in  July  1992.   This risk assessment
was carried out to characterize,  in  the absence of remedial action
(i.e., the  "no-action"   alternative),  the current  and potential
threats to human  health  and the  environment  that may  be posed by

                               24

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exposure to  contaminants migrating from  the soil.   Results  are
contained in  the Final Baseline Risk Assessment,  dated July 21,
1992.  The assessment considers  environmental media and exposure
pathways that could result in unacceptable levels of exposure now
or in the foreseeable future.  Data collected and analyzed during
the  RI  provided  the  basis  for  the risk  evaluation.    The  risk
assessment  process   can  be   divided  into   four  components:
contaminant   identification,   exposure   assessment,   toxicity
assessment, and risk characterization.

6.1 Ch**m'*cal8 of Concern

The risk assessment began by  evaluating the soils data in the RI to
identify the chemicals most likely to  contribute a majority of the
risk.   Five  contaminants  in the surface soils  were selected to
represent the major  potential health risks  at  the  site based on
concentrations  at  the  site,  toxicity,  and  physical/chemical
properties that affect transport and movement.   Chemical data from
the 16 surface soil samples  (the control or background sample was
not included) used to identify potential contaminants of concern
(COCs) is shown  on Table 3.   The Baseline Risk Assessment Report
determined that chromium, copper, lead, nickel and zinc were COCs
at this site.
Soil contaminant migration by  way of  surface water runoff is not
likely at this site.  The railroad spur directly west and adjacent
to the  site  is significantly higher  in elevation  than the site.
Infiltration  through  the sandy  soil would be  expected to  be
relatively rapid.   Surface floods have  not been observed at this
site during the RI.   The removal  action and this remedial action
reduces the likelihood of this pathway occurring.

The  depth to  groundwater at  the Standard  Auto Bumper  site  is
typically  four to  six  feet  below  ground  surface.   Mobile  soil
contaminants above  the water table posed  the principal threat as
they can migrate  to the groundwater and thus pose  a  risk to the
Biscayne Aquifer, which  is the sole source of municipal drinking
water for southeast Florida.

Exposure  pathways  consist  of  four  elements:  1)  a  source  and
mechanism of chemical release to the environment, 2)  a retention or
transport  mechanism  for the  released  chemical,  3)  a  point  of
potential  human  contact with  the contaminated medium,  and  4)  a
human uptake route  (intake of contaminated media) at the point of
exposure.

Currently, the site  and the  surrounding  area is  an industrial
setting  made  up of  numerous  small  businesses.    The closest
residents to the site are 350 feet to  the west beyond the Red Road
Canal.  Therefore, exposure pathways could  involve onsite workers

                                25

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                                   TABLE  3

              CONTAMINANT DATA FOR THE  STANDARD AUTO BUMPER SITE
                                SURFACE SOILS
CONTAMINANT
Aluminum
Antimony
Barium
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Strontium
Tin
Titanium
Vanadium
Zinc
Cyanide
FREQUENCY
    OF
DETECTION
    16/16
     1/16
    14/16
     2/16
    16/16
    15/16
     1/5
    15/16
    16/16
    16/16
    16/16
    16/16
    13/16
    16/16
    16/16
     3/16
    16/16
     5/16
    16/16
     4/16
 CONCENTRATION
     RANGE
                                (mg/kg)
   710
    <6
31,000
   <15
    <2
   890
   8.4
   320
   9.7
  <.05
   8.9
    98
    <5
    13
    <2
    26
 <0.21
7,400
17
43
10
260,000
2,300
3.2
600
17,000
160
19,000
85
0.35
4200
820
54
420
29
400
12
   AVERAGE
CONCENTRATION

     {mg/kg)

       5,930
        10.1
        18.0
         2.0
     118,750
         308
         1.7
         126
       4,431
        79.2
       2,130
        43.9
        0.13
         934
         407
        13.8
        53.1
         5.9
         139
         1.5
  BACKGROUND
CONCENTRATION

     (mg/kg)

       960
       <30
        <5
   180,000
       820
       7.9
     1,700
        23
     <0.05
       <20
       400
       <25
        29
     <0.23
      Frequency of  detection is reported  as  the number of  .samples the
      chemical was detected above detection limits out of the total number
      of samples in which the chemical was analyzed.

      Material was analyzed for but was not detected.  The number is the
      minimum  quantitative limit,  which varies  due to the  presence of
      other compounds in the sample.
                                      26

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for current use and residents  for potential future use.  Based upon
the  four elements  above, the  exposure analysis  identified  the
following exposure  pathways:

     •    inhalation  of  fugitive  dust from the surface
          soils  by onsite  workers,  site  visitors,  or
          hypothetical future residents

     •    incidental  ingestion  of  surface  soils  by
          onsite workers, site visitors, or hypothetical
          future residents

     •    dermal  contact with  surface   soils  by  onsite
          workers,  site  visitors,  or hypothetical  future
          residents

The hypothetical future resident scenario was applied to an adult
resident and a child  resident.  Reasonable maximum exposure point
concentrations of chemicals of concern in air, surface soils,  and
subsurface soils were estimated to quantify intakes of chemicals
for each exposure pathway. General assumptions for the calculation
of the intake factor regardless of pathway and  specific assumptions
for each exposure  scenario are used to estimate  intakes.   These
assumptions  are contained  in  Appendix B.    The Appendix  also
contains the exposure parameters for each receptor.

Reasonable  maximum exposure  point  concentrations  of  COCs  are
estimated on the basis of transport and dispersion modeling and/or
field measurement.    These  concentrations  are used to  estimate
intakes of chemicals  for each exposure pathway.   For  the onsite
worker, the intake  factor for inhalation of fugitive dust is 1.9E-1
mVkg-day for nonearcinogens and 6.9E-2 mVkg-day for carcinogens;
for  incidental  ingestion  of  soils  is  4.9E-7  mg/kg-day  for
none arc inogens and  1.7E-7 mg/kg-day for carcinogens;  and for dermal
contact with soils is  2.0E-8 mg/kg-day for none arc inogens and 7.0E-
9 mg/kg-day  for carcinogens.   Intake  factors for  all  exposure
pathway scenarios are provided in Table 4.

The site is likely  to  continue to be  used for  business or industry
in the  future;  however,  the potential for  future  land  use to be
residential does exist given the proximity of the residents.

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 toxic ity, depending on whether they
exhibit carcinogenic  or nonearcinogenic effects.


                                27

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                                          TABLE 4

                                      INTAKE FACTORS
PATHWAY-SPECIFIC
EXPOSURE
ONSITE-WORKER  SITE VISITOR
             FUTURE ADULT
               RESIDENT
              FUTURE CHILD
                RESIDENT
Inhalation of
Fugitive Dust
     noncarcinogenic
      (mVkg-day)
     carcinogenic
      (mVkg-day)

Incidental Ingestion
of Soils
     noncarcinogenic
      (mg/kg-day)
     carcinogenic
      (mg/kg-day)

Dermal Contact with
Soils
     noncarcinogenic
      (mg/kg-day)
     carcinogenic
      (mg/kg-day)
   1.9E-1

   6.9E-2
   4.9E-7

   1.7E-7
   2.0E-8

   7.0E-9
4.2E-2

6.0E-3
2.1E-7

3.0E-8
1.1E-8

1.6E-9
2.7E-1

1.1E-1
1.3E-6

5.9E-7





7.3E-8

3.1E-8
1.27

4.8E-11*
1.2E-5

NC




3.2E-7

NC
*  -  Memorandum from Solomon Pollard, Jr., Regional Toxicologist, to Barbara Dick,
      Remedial Project Manager, September 4, 1992

NC -  Not calculated since there are no oral slope factors

Source:  Final Baseline Risk Assessment for the Standard Auto Bumper Site
                                            28

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Carcinogens.   Slope factors  (SFs)  have been developed  by EPA's
Carcinogenic Assessment Group for estimating excess lifetime cancer
risks associated  with  exposure to potentially carcinogenic COCs.
SFs, 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 risks
associated  with  exposure at that intake level.  The  term "upper
bound" reflects the conservative estimate of the risks calculated
from the  SF.   Use of  this  approach makes  underestimation of the
actual cancer risk highly unlikely.  Slope 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 (e.g., to account for the use of animal
data  to  predict  effects  on  humans).    Slope factors   for  the
identified COCs are presented  in Table 5.

Nonearcinoaens.  Reference doses (RfDs)  have been developed by EPA
for  indicating the  potential  for adverse  health effects  from
exposure to COCs exhibiting noncarcinogenic effects.  RfDs, which
are expressed in  units  of  mg/kg-day, are  estimates  of  lifetime
daily exposure levels  for  humans  including sensitive individuals
and are listed for site COCs in Table 6.   Estimated intakes of COCs
from environmental media (e.g., the amount of a COC 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 (e.g., to account for
the use of animal  data to predict effects on humans).

6.4 Characterization of Risk

Potential  noncarcinogenic  and carcinogenic risks  posed by  the
chemicals  of  concern  in   the various  exposure  pathways  were
evaluated.  Nonearcinogenic effects are characterized by comparing
estimated chemical intakes with  chemical-specific RfDs  and  are
expressed as the hazard quotient.   Individual hazard quotients are
summed for  all chemicals in  an exposure pathway  to  provide the
Hazard Index  (HI).  HI values  for the site are shown in Table 7.

The  values   exceeding  unity  indicate  potential  unacceptable
nonearcinogenic risk.   All  chemicals of concern posed cumulative
hazard  indices below  one   for each  exposure  pathway,  with  the
exception of  the  future child resident scenario.   The  HI  for
ingestion of surface soils for this child receptor is 8.5, due to
the chromium and nickel in the soil.

Potential risks  from lead exposure were calculated for children
using  the  Uptake  Biokinetic  Model,   since  children   are  very
sensitive to  lead exposure.   The  assessment  determined  that the
level of contamination would result in a blood-lead level below 10
ug/dL, the level of concern, if a family with a child established
a residence at this site in the future.
                                29

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                             TABLE 5

                 CARCINOGENIC TOX1CITY VALUES FOR
                     CONTAMINANTS  OF  CONCERN
                         IN SURFACE SOILS
                      INGESTION
                    SLOPE FACTOR
                 INHALATION
                SLOPE FACTOR
                  DERMAL
                SLOPE FACTOR
CONTAMINANT
(mg/kg-day)'1
(mg/kg-day)'1   (mg/kg-day)
                                                                -i
Chromium
Copper
Lead
Nickel
Zinc
NA
NA
NA
NA
NA
4.2E+1
NA
NA
8.4*
NA
2 . OE+2
NA
NA
NA
NA
*    Integrated   Risk   Information  System   or  Health  Affects
     Assessment Summary Tables (HEAST), 1991.

     Adjusted from an SF to an absorbed dose  SF.

NA - Not Available

Source:  Final Baseline Risk Assessment for the Standard Auto
         Bumper Siter"
                                30

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                             TABLE 6
               NONCARCINOGENIC TOXICITY VALUES FOR
                     CONTAMINANTS OF  CONCERN
                         IN SURFACE SOILS
                      INHALATION
                         RfD
                                      INGESTION
                                         RfD
                  ADJUSTED
                 DERMAL RfD
CONTAMINANT
                      (mg/kg-day)
(mg/kg-day)
(mg/kg-day)
Chromium
Copper
Lead
Nickel
Zinc
5




.7.1E-71
NA
NA
NA
NA
5.0E-31
3.7E-21
NA
2.0E-21
2.0E-11
2.5E-22
0.1852
NA
O.I2
I2
     Integrated   Risk  Information  System   or  Health  Affects
     Assessment Summary Tables  (HEAST), 1991.
     Adjusted from an oral dose to an absorbed  dose RFD.
1.
2.
NA - Not Available
Source:  Final Baseline Risk Assessment for the Standard Auto
         Bumper Site
                                31

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                             TABLE 7
                          HAZARD INDICES
             FOR NONCARCINOGENS FOUND IN SURFACE SOIL
Fugitive Dust
Inhalation
                                  Hazard Indices

Cont ***" t nant
Chromium
Copper
Lead
Nickel
Zinc
HAZARD INDEX:
Ingestion of


Contaminant
Chromium
Copper
Lead
Nickel
Zinc
HAZARD INDEX:
Ons ite
Worker
8.5E-5
NA
NA
NA
NA
8.5E-5
Surface Soils

Ons ite
Worker
0.12
0.0038
NA
0.14
0.00045
0.269
Adult
Resident
0.00012
NA
NA
NA
NA
0.00012

Hazard
Adult
Resident
0.4
0.012
NA
0.47
0.0014
0.88
Child
Resident
0.0006
NA
NA
NA
NA
0.0006

Indices
Child
Resident
3.8
0.12
NA
4.6
0.014
8.5

Visitor
1.9E-5
NA
NA
NA
NA
1.9E-5



Visitor
0.064
0.0019
NA
0.075
0.00023
0.14
Dermal Contact
With Surface


Contaminant
Chromium
Copper
Lead
Nickel
Zinc
Soils

Ons ite
Worker
1.2E-3
3.7E-5
NA
1.4E-3
4.4E-6

Hazard
Adult
Resident
0.0044
0.00014
NA
0.0053
1.6E-5

Indices
Child
Resident
0.0019
0.00059
NA
0.023
7.15E-5



Visitor
0.00068
2.0E-5
NA
0.0008
2.4E-6
HAZARD INDEX:
0.0026
HAZARD INDEX
ACROSS ALL PATHWAYS  0.27
0.0026


0.88
0.043


8.5
0.0015
                                   0.14
NA - Not Available
Source:  Final Baseline Risk Assessment, July 21, 1992
                                32

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Carcinogenic risks are estimated as the incremental probability of
a person developing cancer over a lifetime as a result of exposure
to a potential carcinogen. The chemical intake level  is multiplied
by the  cancer  potency factor.   An excess lifetime cancer risk of
1E-6  indicates  that  an individual  has  a  one  in one  million
additional  chance of  developing  cancer over  a  70-year lifetime as
a  result of  site-related exposure  to  a  carcinogen   under the
specific exposure conditions at  a  site.

The  NCP  states  that  sites  should  be  remediated  to  chemical
concentrations  that  correspond  to an upper-bound lifetime cancer
risk  to an individual  not exceeding 10~6  to 10'4 excess lifetime
risk.  Carcinogenic risk levels that exceed this range indicate the
need  for performing  remedial  action at a site.  The carcinogenic
risk  levels are shown in Table  8.   No carcinogenic  risks levels
exceeded  10E-6, except for the child  resident scenario.   The
carcinogenic risk level  from surface soils for the child receptor
is 2.5E-5,  due to the  risk from chromium and nickel inhalation.
The  estimate   of  carcinogenic  risk   is  conservative  and  may
overestimate the actual  risk due to exposure.

In summary, an  unacceptable nonearcinogenic  and carcinogenic risk
is  present, primarily from chromium  and nickel  at this  site.
Actual  or  threatened releases of  hazardous  substances  from this
site, if not addressed by implementing the response action selected
in this ROD, may present an imminent and substantial endangerment
to public health, welfare, or the environment.

6.5 Environmental Risks

The ecological effects due to  releases  from contaminated soils are
not expected to be significant  for a variety of  reasons.   First,
this site does  not provide habitat resources for wildlife, due to
the industrial nature of the site.  Second, the site and canal data
and the nature of the relationship of the canal to the site do not
indicate there is an offsite environmental risk.  The  sampling data
for surface water from the  nearby  Red Road  Canal  indicates  no
relation to site  contamination.   Also,  canal sediments indicate
minor levels of contamination that cannot be linked to the site,
due to the  high amount of traffic and  industrial activity between
the site and canal. DERM has been made aware of the  findings.  It
is likely that  the lead and zinc could be a result of traffic or
industrial  influences and not  the site.  Contamination via surface
water discharge is not likely  due  to  the  businesses,  elevated
railroad, and  four-lane  road  located  between the  site  and the
canal.

7.0 REMEDIATION GOALS

Risk Assessment remediation goals were developed for chromium and
nickel based upon the  exceedance of acceptable EPA standards (1 for
hazard index and 10'6 for risk level) for the child receptor for the

                                33

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                             TABLE 8

                    CARCINOGENIC RISK LEVELS
                        FOR SURFACE SOILS
                                   Risk Level
Pathway

Fugitive Dust
Inhalation

     Chromium
     Nickel

Ingestion of
Surface Soils (Lead)
Onsite Worker
  7.6E-10
  7.6E-11
     NA
Adult
Resident
1.2E-9
1.2E-10
 NA
 Child
Resident Visitor
2.3E-5
2.3E-6
 NA
6.7E-11
6.5E-12
  NA
Dermal Contact with
Surface Soils (Lead)     NA

TOTAL RISK
FROM SURFACE SOIL:    8.4E-10
                 NA
               1.3E-9
           NA
         2.5E-5
           NA
         7.4E-11
NA - Not Available
Source:  Baseline Risk Assessment, July 21, 1992
                                34

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COCs.   The remediation goal was  developed to provide a level that
would result in a  risk level of  less  than  10~* and a hazard index
of .less than 1.0.   Under these conditions, the remediation goal of
total chromium is  519 mg/kg, hexavalent chromium is 52 mg/kg, and
nickel is 1600 mg/kg.

The EPA determined that nickel and chromium soil remediation goals
(maximum soil concentrations of nickel and chromium) are necessary
to also protect groundwater.  These  remediation goals are designed
to insure that leachate from the soil will not cause concentrations
of  these metals  in groundwater to  exceed  the MCLs.   This  is
important because the Biscayne Aquifer is located beneath the site
and is the  sole source of municipal drinking water for southeast
Florida.

Three  groundwater  models  were   used to  determine  these  soil
remediation goals.   The fate  and transport  model,  MULTIMED, was
used to calculate  the  levels of  contribution to groundwater that
would be caused by given soil  levels of nickel and chromium.  The
geochemical,  metals  speciation   model,  MINTEQA2,  was  used  to
determine the  relative mobilities of  nickel,  chromium,  and other
possible contaminants  at  the site.  And,  finally,  the results of
MULTIMED were cross-checked with  a leaching-flow continuity model,
the SUMMERS MODEL, to  arrive at  the final  soil  cleanup level for
nickel.

Nickel

A  soil/water  distribution  coefficient  (Kd)  for  nickel  of  35
milligrams of nickel/kilogram of  soil per milligram of nickel/liter
of  water  (or  35  I/kg) was determined for the  site by  EPA's
Environmental  Research  Laboratory.   This  Kd  is  fairly  low,
indicating that divalent  nickel  (the  common  species of nickel in
surface and groundwater)  is considerably more soluble and mobile
than many other metals, such as lead or trivalent chromium.  Using
this Kd,  the  soil cleanup  level calculated for nickel was 370
mg/kg.  This cleanup,-level should insure that nickel leaching from
the soil will not  result in a  groundwater concentration exceeding
the nickel MCL of 0.100 mg/1 (100 ug/1).  This level of 370 mg/kg,
for the protection of  groundwater,  is  considerably more stringent
than the protective level for direct exposure to  soil calculated in
the risk assessment  (1600 mg/kg).

Chromium

Chromium can  exist in one  or  both  of two  oxidation states under
normal environmental conditions:  trivalent chromium [Cr (III)] and
hexavalent chromium  [Cr(VI)]. Chromium can be converted between
the two oxidation  states, but typically it  does  not.   For Cr(III)
to be oxidized to  Cr(VI), a catalyst  and an oxidizing agent  (such
as  manganese  dioxide), must usually  be present under very acid
conditions.  The mobilities of the two species of chromium are also

                                35

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quite different.   Cr(VI)  is extremely mobile, even  more so than
nickel;  but  Cr(III)  is  virtually  immobile.    Cr(III)   is  very
insoluble and adsorbs strongly to soil particles.

EPA analysis for Cr(VI)  in the groundwater indicated none present,
with a minimum detection level of 10 ug/1.  Back-calculating this
level through the MOLTIMED model showed 10 ug/1 in the groundwater
would be equivalent to only 0.05 mg/kg of Cr(VI)  in the soil.  This
indicates that virtually all chromium present must be Cr(III) and
that particulate transport of Cr(III) on colloidal material is the
most likely mechanism through which Cr is found in the groundwater.
While this  mechanism cannot be modeled  at  present,  a reasonable
assumption is that adsorption of these colloidal particles onto the
aquifer matrix would decrease the measurable amount of total Cr in
the groundwater over time.

Because of  the  uncertainties of modeling the fate  and colloidal
transport of Cr(III), a  toxicological  approach was used.   This
approach considers the uncertainty of both the oxidation  states of
chromium  and toxicological  effects  of  both Cr(VI)  and Cr(III).
This approach resulted in a  soil cleanup recommendation  for total
chromium of 519  mg/kg and hexavalent chromium of  52 mg/kg,  based on
an inhalation risk, which will also  insure that any leachate from
the site  will not cause  the State  drinking water  standard (0.1
mg/1) or MCL  (0.1 mg/1) for chromium to be exceeded.

Other Remediation Considerations

High soil concentrations of nickel and chromium are typically found
at the site in areas  which also contain the highest concentrations
of other  metals,  such as  copper,  lead,  and zinc.   These metals
would be  removed  as  nickel and  chromium is removed,  therefore
reducing the  overall  cumulative  risk below protective levels for
both soil and groundwater.   In  cleaning up soils above the water
table at  the site which  contain nickel above   370  mg/kg,  total
chromium above  519 mg/kg,  and hexavalent chromium above 52 mg/kg
these protective levels would be attained.

These soil cleanup goals are expected to insure that drinking water
standards would not  be exceeded in the downgradient groundwater.
This  expectation,   subject  to  verification   by  groundwater
monitoring, would minimize the measures necessary for groundwater
remediation which will be  addressed in OU #2.  These cleanup goals
will also reduce the risks associated with direct health threats to
a  child,  considering the   future  child  resident   scenario,  to
protective levels.

Based on analytical data collected during the RI and presented in
the RI Report, a total of  2500 cy of  soil are estimated to contain
contaminants above the soil  remedial  goals of 370 mg/kg nickel, 519
mg/kg total chromium, and 52 mg/kg hexavalent chromium.


                                36

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 8.0  DESCRIPTION OF ALTERNATIVES

 A feasibility study was conducted to develop and evaluate remedial
 alternatives  for contaminated soils at  the Standard Auto Bumper
 site.    Remedial  alternatives  were  assembled  from applicable
 remedial  technology process options and were initially evaluated
 for  effectiveness, implementability,  and cost.   The  alternatives
 meeting these criteria were then  evaluated and compared to nine
 criteria  required by the NCP.   The  NCP  also, requires that a no-
 action alternative be considered at every site  to «erve primarily
 as a point  of comparison  for other alternatives.

 8.1  Alternative 1  - Ho Action

 Capital Cost:   0
 Present Worth (PW)  Operation & Maintenance  (O&M) Cost:  $94,700
 Total  PW:   $94,700
 Months to Implement:   None                            v

 This alternative  does not  provide any remedial  activities  to
 address the source of contamination.    Contaminants  in  the soil
 would  continue  to  leach into  the groundwater.  Monitoring for at
 least   30 years would be  included to  evaluate  trends   in  the
 contaminants'   concentrations  in  the   groundwater   due  to  the
 continued  migration  of  contaminants  in  the   soil.   Existing
 monitoring  wells   would  be  used   for  long-term  groundwater
 monitoring.

 Because this alternative would result in contaminants remaining on-
 site,  CERCLA requires  that the site be reviewed every five years.
 If indicated by the review, remedial actions would be implemented
 at that time to remove or treat  the contaminated soil.

 The  No  Action alternative was considered as a baseline option for
 comparison to other remedial action alternatives.

 8.2 Alternative 2  - Excavation and Offsite  Disposal

 Capital Cost: $298,000             Total PW:  $338,186
 PW O&M:  $40,186                   Months to Implement:  Two

 This alternative would consist of excavating the contaminated soil
 and  loading it  onto trucks and  hauling it to  a  Florida  Class I
 solid  waste landfill.   After  excavation, clean backfill material
would be placed and the area would be regraded.

 The landfill requires all  soils to be nonhazardous waste as defined
by 40 CFR 261.  Because it has been confirmed during the RI/FS that
 the soil at the site is neither characteristic or listed hazardous
waste,  DERM has  approved the disposal of the contaminated soil at
 the  county  or other local landfill.   Wastes are considered to be
 RCRA characteristic if they exhibit Toxicity Characteristics (TC).

                                37

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The TC  rule  specifies chemicals which, if present in waste at or
above regulatory levels set in the rule, make the waste a hazardous
waste.   The  contaminants at  Standard  Auto Bumper were below the
regulatory levels.

The  contaminated soil would  be excavated to  either the cleanup
level or the point when the water table is encountered. Dewatering
would   be very  difficult   at  this   site,   due  to  the  high
transmissivity  of  the aquifer.  Groundwater is estimated to be at
a  depth  of  4  to  8  feet.    Confirmation  samples would  then be
collected at the base of any  excavation not into  the  groundwater.
If the results indicated that contaminants are  still  above cleanup
levels  (370  ing/kg nickel, 52  mg/kg  hexavalent chromium,  and 519
mg/kg total chromium), then additional soil would be  removed until
the cleanup level is met  or groundwater is reached.  If all cleanup
goals were attained  the area  would be  backfilled  with.clean soil.
For optimal  performance  of  this remedial action  alternative, the
soils  would  be  excavated during dry periods of the year.   As
determined in the previous  section,  the  site contains separate
blocks  of areas to be excavated.   At a minimum,  excavation would
occur in  the areas indicated on Figure 11.  The total  volume to be
excavated would be approximately 2500  cubic yards.

The  excavated soil  would  be  placed in containers  or trucks by
standard dirt-lifting equipment, such as a backhoe, and transported
to the  landfill.   DERM would  be notified  that the soil would be
taken to the  landfill. Transportation routes to the landfill would
be established  for safe transport.

Periodic  groundwater monitoring would  determine the effectiveness
of the alternative at reducing migration of inorganic  compounds to
the groundwater.  Existing wells would be sampled  periodically for
up to 5 years.

8.3 Alternative 3 -  Excavation, Onsite Soil Washing.
                     and Onsite Replacement

Capital Cost:  $878,000            Total PW:  $891,650
PW O&M:   $13,650                   Months to Implement:  Seven

Alternative  3  consists  of  excavating  the  contaminated  soils,
washing the soil with the  washwater and/or solvent, placement of
clean soil back into the excavated area, washwater treatment, and
sludge  disposal.   The replaced soil would be  covered with clean
soil and graded. Excavation would follow the procedure outlined in
Alternative 2 above.

As shown in Figure 12, the soil washing process would consist of a
temporary soil  mixing/scrubbing unit to uniformly distribute the
solvent washwater in the  soil. As the 2500 cy of  excavated soil is
placed in the unit in  batches, the washwater and  solvent is mixed
thoroughly with the contaminated soil.  Rinse water is then applied

                                38

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HAMAS 8ROTMCRS
 AUIO RtPAM
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                                                                               SOU IS ABOVE CLEANUP COALS
                                                                              GRAPHIC SCALE
                                                                                       0      50     100


                                                                                    ( IN FEET )
                                                                                    FIGURE ||
                                                                           SOIL ABOVE CLEANUP GOALS

                                                                             STANDARD AUTO BUMPER
                                                                                IIIAIFAM. FIOKIOA
                                                                                     "KM
                                                                                     IOCAIHNS IOCAKO MLAnvl ID

-------
                 Figure  12

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Coolnminaled Soil
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                                                                                       Source: UFA

-------
to the  soil  to  remove  any residuals.  Any remaining washing agent
within  the soils would be removed with a non-hazardous  solvent. The
clean rinsed soil would be sampled to verify all contaminants meet
the cleanup  goals.  If all cleanup goals are met,  the soil would be
replaced on  site and the excavation area backfilled and regraded as
needed.  If cleanup goals are not  met,  then the  soil  would be
washed  again.

The collected washwater containing the contaminated soil particles
would  undergo   dewatering treatment  onsite,  such  as  gravity
separation,  flocculation,  or vacuum  filtration.  The concentrated
fines from the  dewatering are estimated to be 10% of the original
mass  of the treated soil.  These  fines would be treated through
solidification  or disposed in  a RCRA  hazardous  waste landfill,
depending on the quantity and concentration of the  contaminants.

The fines would be tested prior to offsite disposal.  These fines
would probably  be characterized as RCRA characteristic wastes for
lead, chromium, cadmium, or arsenic because the contaminants are
concentrated into the  smaller volume of soil.

The TCLP would be performed on the concentrated fines from the soil
washing process prior to disposal.   If the  fines exceed any of the
leachate regulatory levels, the fines would be handled  as hazardous
waste.   For offsite disposal the fines would be  manifested by a
licensed hazardous waste hauler and transported to an approved RCRA
Subtitle C  hazardous waste landfill.   For  onsite disposal,  the
fines would  be  treated to  comply with the TCLP regulatory levels.

The rinse water may  be treated before it would be recycled to the
soil washing process.

Screening  level  treatability  tests  performed  during  the  RI
indicated  soil from  the site  was  not  amenable  to  use  of
hydrochloric  acid  as  an extracting  agent, indicating  another
treatability test would be necessary prior to actual application of
this alternative.

8.4 Alternative 4 -  Excavation. Stabilization/Solidification
                     and  Onsite Disposal

Capital Cost:   $232,000            Total PW:  $385,225
PW O&M:  $153,225                   Months to Implement:  Three

This  alternative consists of excavating the contaminated soils,
chemical stabilization/solidification  of the soils and placement
onsite.   A treatment diagram is provided on  Figure  13.  Excavation
would   follow  the  same  procedure  as described  in  the  above
alternative.  The 2500  cy of excavated soil would then  be placed on
a temporary  storage  pad  or directly into the fixation units.

Soil would be processed  in the fixation units onsite with one or

                               41

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Stabiliza//on solidification.
Bulk
Liquid
Storage



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Storage
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Wasie r
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	 Liquid Chemical
Feed Pump
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3' ' cr Curing
A.-93
                                 Source. EPA
               Figure  13

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more fixation/solidification agents such as silicate and portland
cement or fly ash to ensure the new material remains non-hazardous,
with respect  to the contaminant leachability, and  to  ensure the
contaminants do not contribute to groundwater degradation.  Inside
the process  unit as the soil  enters the  mixer approximately 10%
water is added along with the cement dry agent.  The operation is
similar to cement mixing and when the mixture is at a wet concrete-
like consistency,  a liquid reagent can be  added, which enhances
chemical encapsulation of the metals.

This solidified mass can be transferred from the mixer using a pump
to the desired  placement location.  The mass would  be  tested
for compressive  strength.  Unconfined compressive strength at the
design cure period would be at least 50 psi.  Permeability would be
required to  be  less than 10~5  for land burial.   The treated soil
would be replaced in excavation areas and  is expected to undergo a
15-25%  increase in volume.    The  specific  placement  would  be
determined  and   evaluated during the  remedial design  and  would
consider the depth of the water table.  The fixation process units
would be  set up on site.   Samples would  be required  from the
treated  soil to assure compliance  with long-term leachability
criteria.  The solidified monolith would be covered with soil and
vegetated.   Deed restrictions  would  be implemented  to  ensure the
integrity of the solidified material.

For placement of treated soil below the surface,  long-term O&M
would   include   monitoring   wells   surrounding  the   monolith.
Groundwater monitoring  would determine the effectiveness  of the
alternative  at  reducing migration of  inorganic  compounds  to the
groundwater.    Existing wells  or  new  wells would be sampled
periodically  for a  minimum of  30 years after the construction is
completed.

Onsite  maintenance  would  also be  required  and  would include
checking  the monolith  area  for erosion.   The screening  level
treatability    test   performed   during   the   RI   indicated
stabilization/solidification was effective in reducing TCLP levels
in nickel  and copper.   Lead was not  affected and  chromium TCLP
levels  increased but  were  still below TCLP  regulatory levels.
Another   treatability   test   would   be   necessary   prior   to
implementation of this alternative to determine optimal stabilizing
agents.  However, this is a proven treatment  for metal-contaminated
wastes.

9.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES

The remedial alternatives developed in the FS for  contaminated soil
were  analyzed  in  detail using nine  evaluation criteria.   The
resulting strengths  and weaknesses  of  the alternatives were then
weighed to  identify the alternative providing  the  best balance
among the nine criteria.  These criteria are 1) overall protection
of human health and the environment;  2) compliance with applicable

                                43

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or relevant  and appropriate  requirements  (ARARs);  3) "reduction of >•
toxicity,  mobility,  or volume  through treatment; ' 4)  long-term
effectiveness^ and  permanence; " 5)  shorty-term  effectiveness;  tf)
implementability;  7)  cost;  8) state acceptance; and 9)  community
acceptance*.  -.The first  two criteria are .essential  and  must be me\ -
before  an-^alternative  is  considered^ffurther.   The  next   frv«£
criteria are used to further  evaluate all  options that meet the
first two  dg&beria.  The final  two  ciSferia are used to further*
evaluate the'/propos'ed  plan  after thec^foblic  comment period has 6
ended  and  comments  from the  community^ and the  State have  beenr
received.  This evaluation of eaoh of tlie alternatives.-against the.*
nine criteria is  summarized  below.

Overall  Protectiveness.  All  of the  alternatives except the  no
action  alternative   are protective   of  human health   and   the
environment  and comply  with  the ARARs identified  for the site or
obtain an equivalent level of performance.   Therefore,  Alternative
1, no action, is not acceptable and will not be considered further.
Risk of exposure from further migration of the contaminants through
the soil to  the groundwater  is reduced in Alternatives 3  and  4 by
treating  the contaminated   soil  to  the cleanup  levels  and  in
Alternative  2  by removing the contaminated soil  to the cleanup
levels.   Alternatives  1,  3f  and  4  all provide protection  from
contaminant  migration  from  the  soil  to   the  groundwater.     In
addition,  risk  associated with the  child  resident  scenario  is
minimized by these alternatives.

Compliance with ARARs.   All alternatives  would  comply with the
Federal  and  State action-specific  ARARs.    Applicable action-
specific  requirements  would  be  the  Resource  Conservation   and
Recovery Act (RCRA)  regulations (for hazardous wastes as defined by
40 C.F.R 261).  Because there are no RCRA listed or characteristic
wastes at the site, this requirement  would not apply to the soils.
However, this requirement may apply to the treatment residuals  from
the site, depending on  whether they  are listed or characteristic
wastes.   Any hazardous  waste  would  either  be  treated to levels
below the TCLP regulatory levels or be taken to a  RCRA Subtitle C
hazardous waste landfill.

Contaminated media that  is not listed or characteristic waste would
need to be disposed in  a Florida Class I landfill, therefore the
FDER Class  I and RCRA  Subtitle D landfill regulations  would  be
applicable.

Other action-specific requirements that would be appropriate
are Department of Transportation Hazardous Materials Transportation
rules for off site transport,  and National Air Quality Standards for
excavation.  State  action-specific requirements that would apply
are the Florida Ambient Air Quality Standards and  the  Florida Air
Pollution Rules.
                                44

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                    ' \                         -       .
 No chemical-specific ARARs are available for soil and there are no
 location-specific ARARs.

 No waiver from ARARs is necessary to implement any alternatives.

 Long-Term Effectiveness and Permanence.  Alternative 2 would remove
 all waste to a permitted offsite landfill,  thereby eliminating any
 long-term risks of  exposure  at  the site.   This alternative  also
 offers a high  degree of  certainty  that it  will be executed
 successfully  and  is considered to be  an  irreversible permanent
 remedy.   Alternative 3 employs an irreversible treatment process to
 provide  long-term effectiveness and permanence to reduce  hazards
 posed by all  known wastes  at the  site.   Alternative  4 utilizes
 treatment to  achieve slightly less long-term effectiveness.  The
 stabilization/solidification  process does  have a low potential to
 leach contaminants  in the future  and therefore  may not be as
 permanent as the other two alternatives. However,  this technology
 has been  demonstrated to be effective at similar sites and long-
 term monitoring of the groundwater would detect any breakdown of
 the treatment  remedy.   Alternative 4 would rely on  institutional
 controls  to ensure  future integrity of the  solidified material, by
 requiring deed restrictions.

 Reduction of Toxicity,  Mobility, or Volume.   Alternative  2 would
 reduce the toxicity, mobility,  and volume  of contaminants  at the
 site.  This alternative would not utilize  treatment; however, the
 estimated 2500 cy  of  waste would be transported  to a permitted
 landfill  offsite where mobility would be reduced by containing the
 contaminated soil in a  secure  landfill.   However,  toxicity and
 volume would not be reduced.   Alternatives 3 and 4  use treatment or
 fixation  technologies to reduce  the inherent hazards posed by the
 soil  contaminants  at  the site.   These  two  alternatives would
 satisfy  the statutory  preference  for  treatment as a principal
 element,  to the maximum extent practicable.

 The   stabilization/solidification  process   in   Alternative  4
 encapsulates the soil contaminated with heavy metals, reducing the
 mobility  of the  metals.   There  is  a small  potential  for the
 fixation  process not to maintain the contaminants in the chemical
 bond  in  the long-term,  thereby initiating risk  of contaminants
 migrating to the  groundwater.  Treatability tests would minimize
 this  possibility.    The stabilization/solidification  process in
 Alternative  4  increases the soil  volume  by  the addition of
 cementing materials and/or additives.   The increase in volume is
 estimated to  be fifteen  to  twenty-five percent  of  the original
 waste material.

 Soil washing in Alternative 3  uses chemical interactions to reduce
 the toxicity, mobility or volume  of the soil contaminants to levels
 which are protective of groundwater.  However, this technology has
 not demonstrated  full  capability of attaining the cleanup  goals.
Alternative 3  would require  additional management of  residuals.

                                45

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The treatment process for this alternative would reduce the volume
of contaminated soil by washing the contaminants from the soil  into
a concentrated waste stream.'  This smaller volume of waste contains
the  finer soil particles, contaminants  and  some washwater.   The
washwater would require treatment and the concentrated contaminated
fine  soil would require treatment or offsite RCRA  hazardous waste
disposal.  The soil washing process in Alternative 3 would render
approximately 90% of the  soil uncontaminated.

Short-term effectiveness.  Alternative 2, 3,  and 4  are  expected to
be  protective of  human  health and  the  environment   throughout
construction  and implementation.   Similar  risk  exists  for all
alternatives to workers,  the  community and the environment during
excavation  and  treatment or  removal.   Alternatives 2,  3,  and 4
would involve implementing dust control measures  during excavation
of the soils to prevent release of  increased  particulates into the
atmosphere.

Alternatives 2 and 4 would provide protectiveness  in a relatively
short time, compared to Alternative  3.   A construction period of
only  one month  for Alternative 2  and  two  to  three  months for
Alternative 4 would be  required to achieve short-term  protection.
Alternative  2   poses   a  risk  during   transportation  of  the
contaminated soil to the offsite facility and Alternatives 3 and 4
pose  a risk during the  treatment process.  Careful implementation
of standard safety protocols  would lessen  this risk.

Alternative  3  is  anticipated  to  have  the   least   short-term
effectiveness.     Alternative  3   would  require  the  longest
implementation time  of five  to  seven months.   This  alternative
poses a risk of accidental exposure to the soil washing additive.
Also, there  is a risk the cleanup goals  may not easily  be met
during the soil washing, which would require  additional washes and
additives.  This would slow  the process.  Alternative  3 requires
treatability tests to determine effectiveness and  optimal design,
prior to  starting.

Implementation.   Alternative 2  would  not  require   specialized
materials,  and  equipment beyond  common  excavation   equipment.
Alternative  2  is  a  proven  technique  and would not  require
treatability studies.   Prior to disposing offsite, this  alternative
would require coordination with the landfill.  Alternatives 2 and
3 would  require  less   future  O&M  than  Alternative 4  since the
contamination is removed from the site or the soils, respectively.

Alternatives 3  and 4  would  both require  specialized  equipment,
materials, and labor, which is available from a variety  of vendors.
There are more vendors  available for stabilization/solidification
in Alternative 4 that have demonstrated effectiveness than for  soil
washing   in  Alternative  3.    The   solidification  process  of
Alternative 4 can be conducted onsite in a suitable area which is
large enough for portions  of the soil to  be processed and allow for

                                46

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workers to operate the equipment.  Alternative 3 would require, more
elaborate process equipment than Alternative 4,  which would drive
up the cost.  Treatability tests would be required for Alternatives
3  and  4  to ensure  that  the  soil washing would  remove  the
contaminants to  concentrations below the  cleanup goals,  and to
ensure   the  mixtures   of   fixation  agents  would  prevent  the
contaminants from leaching  into  the groundwater,  respectively.
However, the nature of the contaminants  and  the characteristics of
the soil have  been shown to be more  responsive  to the treatment
process  in Alternative  4 than Alternative 3.
                                «*
Soil  washing (Alternative 3)  has  been  selected as  the remedial
alternative  at other  Superfund sites; however,  the cleanup goals
for these sites were higher than those  for this site.  Also, soil
washing  was not  shown to  be  as  effective as  stabilization/
solidification for the contaminants  at the site  in  small scale
treatability tests and soil washing requires a larger area  for the
process  operation than  the fixation alternative.

Cost.   Alternative 2  is  the most economical alternative  with a
total  present  worth cost  of  $338,186.   This  alternative offers
similar  protectiveness compared to the other alternatives and is a
proven technique.  Alternative 4 has a total present worth  cost of
$385,225.  The  higher cost  of Alternative 4 is primarily due to the
O&M, which accounts for 40% of the total cost.

The soil washing process drives the high capital cost of $878,000
for Alternative 3 and the low O&M cost of $13,650 does not  totally
replace  the  loss  of  money to capital outlay.  This alternative's
total  present  worth  cost  of  $891,650  is   the  least economical
without  providing additional protectiveness.

It is  assumed  for all alternatives that construction would begin
within one year.

State  Acceptance.   The State  of Florida,  as represented by the
Florida  Department of Environmental Regulation (FDER), has been the
support  agency during the Remedial Investigation and Feasibility
Study  process  for the  Standard Auto  Bumper site.   In  accordance
with 40  CFR  300.430, as the support agency FDER has provided input
during this process.  Based upon comments received from FDER, it is
expected that  concurrence  will be forthcoming;  however, a formal
letter of concurrence  has  not  yet  been  received.

Community Acceptance.    The  local  Dade  County  Department of
Environmental  Resources (DERM) has been involved with this site.
EPA has  consulted DERM  on the site and the alternatives.  DERM and
EPA will continue to work  together  to  provide  the best remedial
action  which minimizes  the potential  for  impacts  to the nearby
businesses and residents to the site. DERM has provided assurance
that the soil may be  sent  to a Florida  Class I Landfill.


                                47

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During the 30-day public  comment period, no comments were received
from the community.  The  public meeting at which EPA presented the
proposed plan was attended by three people.   Overall,  there has
been very  little community interest at this  site  throughout the
Superfund process, even though over 400 proposed plans were sent to
the  community,   media,  and  government officials  and  newspaper
articles have highlighted  this site.   There is no  indication the
public would not  support the selected remedy.

10.0 SELECTED REMEDY

Based upon consideration of the requirements of  CERCLA, the NCP,
the  detailed  analysis  of alternatives  and public  and  state
comments, EPA has selected a source control remedy for this site.
At the  completion of this remedy, the risk associated  with this
site has been calculated  at less than 10"6 for carcinogens and less
than one for nonearcinogens, which is determined to be protective
of human health  and will be protective of  the environment.   The
total present worth cost  of the selected remedy, Alternative 2, is
estimated at $338,186.

A. SOURCE CONTROL

Source control remediation will address the contaminated soils at
the site.   Source control shall include excavation of contaminated
soils, transportation to a Florida  Class  I landfill,  backfilling
the excavated area and site monitoring.

     A.I. The major components of the source control to
          be Tmplemented includes

     •    Complete excavation from the surface soils of
          soil   contaminated  with  total   chromium,
          hexavalent  chromium,  or  nickel  above  519
          mg/kg,  52 mg/kg, and 370 mg/kg, respectively,
          or   interface   with   the   water   table
           (approximately 2500 cubic yards).

     •    Offsite  disposal of  the excavated soil  at  a
          Florida Class I  landfill,

     •    Backfilling the  excavated areas with clean fill, and

     •    Groundwater monitoring for the contaminants of
          concern for up to 5 years.

     A.2. Performance Standards.

The performance standards for this component of the  selected remedy
include,  but are not limited to,  the following  excavation and
disposal standards:


                                48

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          a.  Excavation  Standards

          Excavation  shall continue until the remaining
          soil  achieves  the maximum  levels below or
          until  the  water  table  is  reached.    All
          excavation  shall comply with ARARs, including
          but not  limited to the Clean Air Act, Florida
          Air  Pollution  Rules,  Florida  Ambient  Air
          Quality  Standards, Subtitle  D requirements,
          and DOT  requirements.   All work  at the site
          shall comply with OSHA requirements.  Testing
          methods  approved by  EPA or that are the best
          available   technology  shall   be  used  to
          determine if  the maximum nickel and chromium
          concentration  levels shown  below  have been
          achieved in the remaining soil.

               Total  Chromium           519 mg/kg
               Hexavalent Chromium      52 mg/kg
               Nickel                  370 mg/kg

          The  soil  cleanup  levels  are  necessary  to
          ensure that migration of all the contaminants
          into  the groundwater  is  minimized and were
          developed during the Risk Assessment based on
          risk to  human health and the environment (the
          groundwater).  Cleanup to these standards will
          ensure that contaminants do not  continue to
          migrate  into the groundwater and human health
          risks are reduced to protective levels.

          b.   Disposal Standards

          Transportation  of  the  contaminated soil will
          be   conducted   in   accordance   with   DOT
          regulations.    The excavated  soil shall  be
          transported from  the  site  to  the Class  I
          landfill (liner and leachate collection) using
          approved  transportation   routes   for  safe
          transport.  All soil to be disposed of off site
          must meet the following criteria:

          • Non-hazardous waste as defined by the TCLP
            test (40  CFR  261)

          The  landfill  must  meet   FDER Class  I  landfill
          regulations.
B.  COMPLIANCE TESTING
Groundwater monitoring shall be  conducted  at this  site.   After
demonstration of  compliance  with Performance Standards, the site
                                49

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groundwater shall be monitored for the contaminants of concern for
up to  five  years to verify that  the  removal of the contaminated
soil in excess of those  levels  set forth  in  paragraph A. 2 does
minimize the impact these contaminants have on the quality of the
underlying  aquifer.    If  monitoring  data  indicates   the soils
continue  to  be  a  source of groundwater contamination  after
implementation  of  the remedial action, EPA will re-evaluate the
effectiveness of the remedy.

Because  this  remedy will  not  result  in  hazardous   substances
remaining onsite above  health-based levels, the five-year review
will not be necessary at this  site.

11.0 STATUTORY DETERMINATIONS

EPA's  primary  responsibility  at  Superfund Sites  is  to select
remedial  actions that  are protective of  human health  and the
environment.   CERCLA also requires  that the  selected remedial
action  for  the site  comply  with  applicable  or  relevant  and
appropriate environmental standards established under Federal and
State environmental laws,  unless a waiver is granted.  The selected
remedy must also be cost-effective and utilize permanent treatment
technologies  or resource  recovery technologies  to the  maximum
extent practicable.   The  statute also contains  a  preference for
remedies  that include  treatment  as  a principal  element.   The
following sections  discuss how the selected remedy for contaminated
soils  at the  Standard  Auto  Bumper  site meets these  statutory
requirements.

Protection of Human Health and Environment:

The selected remedy protects human health and the environment by
reducing levels of  contaminants in the source of contamination, the
soils,  through excavation  and containment.  Eliminating  the source
of contamination will reduce levels  of  contaminants migrating from
the soils into  the groundwater,   and reduce  the  threat  to levels
below  10"6 for carcinogens  and a Hazard  Index of below  one for
nonearcinogens for  future  child  residents ingesting contaminated
soil.  No unacceptable short-term risks or cross-media impacts will
be caused by implementation of the remedy.

Compliance with ARARs

All ARARs will be met by the selected remedy.

Chemical-Specific  ARARs.    No chemical-specific ARARs  apply to
contaminated soils.

Action-Specific ARARs.  Federal action-specific ARARs include the
National Ambient Air  Quality  Standards under  the  Clean Air Act.
State action-specific ARARs  include the Florida Air Pollution Rules
FAC 17-2.1 and Florida Ambient Air Quality Standards FAC 17-2.3.

                               50

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RCRA  Land disposal  restrictions  (LDRs)  are  not applicable  or
relevant and appropriate.  The contaminated soil at the site is not
a listed or  characteristic  RCRA waste.   In studies conducted for
the FS, the  soil  did not  exceed the regulatory TCLP criteria for
chromium and lead (no regulatory level has  been established for
nickel).

Nickel, chromium, and lead are listed CERCLA hazardous substances
as defined by CERCLA 40 CFR 302.4.   However, because the soil is a
RCRA non-hazardous waste  it may be  disposed in a permitted solid
waste landfill.   Therefore the RCRA Subtitle  D requirements and
FDER  Class  I requirements  will apply to  the  landfill  and  DERM
requirements for soil disposal in a local landfill will also apply.


DOT requirements will be appropriate to consider during transport
of the contaminated soil to the landfill.

Location-Specific ARARs. No location specific ARARs are applicable
or relevant and appropriate for the site.

Cost-Effectiveness

After evaluating  all of the  alternatives  which  satisfy  the two
threshold criteria  above,  EPA has  concluded the selected remedy
affords the highest level  of overall effectiveness proportional to
its cost.  Section 300.430(f)(1)(ii)(D) of the NCP also requires EPA
to evaluate three out of  the  five balancing criteria:   long-term
effectiveness and permanence; reduction  of  toxicity,  mobility or
volume  through   treatment;   and short-term  effectiveness,  to
determine overall effectiveness. Cost-effectiveness is determined
by  evaluating  these  balancing criteria  to  determine  overall
effectiveness.  Overall effectiveness is then compared to cost to
ensure that  the  remedy is cost-effective.  The  selected remedy
provides for overall effectiveness  in proportion to its cost.

The estimated total present worth cost for the selected remedy is
$338,186.

Utilization  of  Permanent  Solutions  and  Alternative  Treatment
Technologies  or Resource  Recovery Technologies to the M^^imnm
Extent Practicable ("HEP")

EPA believes the selected remedy represents the maximum extent to
which permanent solutions  can  be  utilized in  a cost-effective
manner for the  Standard Auto Bumper site.   After evaluating the
alternatives  that   are protective of  human  health  and  the
environment  and comply with ARARs, EPA has determined  that the
selected remedy provides the best balance in terms of the remaining
criteria.

The  selected  remedy   includes  offsite  disposal  of  untreated

                                51

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contaminated  soil which  does  not  satisfy the  preference  for
treatment as a principal element. EPA has determined however that
the benefits of this  alternative,  as  determined by the balancing
and modifying criteria,  outweigh the disadvantage of not employing
treatment.  Treatment was  found to  be  unnecessary for the waste at
this site,  due to the  non-hazardous  nature of  the contaminated
soil, as defined by RCRA.   However, a cleanup action is necessary
to  reduce  the risk  to  human  health  and the  environment  to
acceptable  levels.   In making  the determination  for  or against
offsite disposal, the modifying criteria of state acceptance was
considered  (Section 300.430(f)(1)(ii)(E) of the NCP.  In light of
this consideration,  EPA decided after  evaluating all nine criteria
to select excavation and offsite disposal for this site.

This selected remedy provides protectiveness; attains ARARs; offers
long-term  effectiveness and  permanence;  and  reduces  toxicity,
mobility, or volume of  contaminants at the site.   Excavation and
offsite  disposal  requires the  simplest equipment,  the shortest
implementation time,  and  is the most cost effective  of  all the
alternatives.

This remedy is consistent with future  response actions that may be
considered for the site by addressing the source of contamination
at the site.   Source control reduces  or eliminates the level of
further  action at the  site  that would  be necessary  for  OU f2,
groundwater.

Preference for Treatment as a Principal Element

The statutory  preference  for treatment  is not satisfied  by the
selected remedy;  however, excavation and  offsite disposal utilizes
a cost-effective method to  address  the threats posed by conditions
at the site. The cleanup objectives of the selected remedy address
the health and environmental threats at the site:  direct contact
with contaminated surface soil and migration of soil contaminants
to the groundwater. ..The remedy will reduce the toxicity, mobility,
and volume of the co'ntaminants at the site and will provide long-
term effectiveness and permanence.

12.0  DOCUMENTATION OF SIGNIFICANT CHANGES

The Proposed Plan was released for public comment during August and
September 1992.  Three changes to the  Proposed Plan have been made
since its release and will be described  in this section.

The  Proposed  Plan   identified Alternative  4,   excavation  of
contaminated   soil,   onsite   stabilization/solidification,   and
groundwater monitoring, as the preferred alternative.  One of the
other alternatives (Alternative 2)  presented in the Proposed Plan
and in the FS involved excavation of contaminated soils  and offsite
disposal.  The original preference for Alternative  4 was based in
part  on  the  preference   for  employing  an  onsite  treatment

                                52

-------
 alternative at a site.  However, during the public comment period,
 staff  at PDER voiced a preference for Alternative 2 because  this
 alternative did  not require the long-term O&M that Alternative  4
 required.   Groundwater monitoring for up to 30 years was  necessary
 to  ensure the   integrity  of   the   stabilization/solidification
 treatment  in  Alternative  4.   Upon re-evaluation  of  the  two
 alternatives,  the offsite disposal remedy was determined to  be  a
 more reliable, long-term effective,  permanent, implementable, and
 cost-effective remedy for the estimated quantity  of contaminated
 soil   at   the    Standard   Auto   Bumper    site    than    the
 stabilization/solidification remedy  originally preferred.

 The Proposed  Plan did not state that institutional controls would
 be required  for  Alternative 4 to  ensure the  integrity  of  the
 solidified material.   EPA decided  that  deed restrictions would
 provide  more  effective  long-term   protectiveness   for   this
 alternative and has included it in the  description of  Alternative
.4.

 Lastly, the Proposed Plan stated a cleanup goal  for nickel  only.
 EPA and FOER decided that  a cleanup goal was also necessary for
 chromium to  ensure this  contaminant was  reduced to protective
 levels during the implementation of  the remedy.
                                53

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APPENDIX A

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                      RESPONSIVENESS SUMMARY

 This  summary presents all of  the  Agency's responses to comments
 received from  the community,  local officials,  and potentially
 responsible  parties  (PRPs)  for  the Standard  Auto  Bumper site
 operable unit one,  soils.

 A.  OVERVIEW

 At  the  start  of  the public  comment  period,  EPA  released its
 selection for the  preferred alternative  via the media  and the
 proposed plan.   EPA's recommended alternative  was excavation of
 contaminated  soil,  onsite   stabilization/solidification,  and
 groundwater  monitoring.   Based on the comments received from the
 State of  Florida  and  documented  herein,  EPA  re-evaluated the
 alternatives and selected another alternative.   The alternative
 specified in  this  Record of  Decision  involves excavation  of
 contaminated soil and offsite disposal.

 Judging  from the  comments  received from  the  residents  in the
 community during the public comment period, the community would not
 be  adverse to excavation and offsite disposal.  The local citizens
 did not  voice objections to any of the  alternatives.

 B.  BACKGROUND ON COMMUNITY INVOLVEMENT

 Community interest  in the  Standard Auto Bumper site has been very
 limited dating back to the  start of the Remedial  Investigation when
 EPA held a  public availability  session at  the Henry M.  Filer
 Middle/Community School.   The  meeting,  held on January 10, 1991,
 was announced in  the  local newspaper and an EPA fact sheet.  The
 only  person  from the community who  attended  the meeting,  was an
 employee  of  the Standard Auto Bumper Corporation.   EPA has made
 information  on  the site available at the  local  library  and the
 Regional office in Atlanta, Georgia.   These  files are updated as
 new material is generated  concerning the site.

 During   the  Remedial  Investigation/Feasibility  Study,   public
 interest remained at the  same low level.   Calls the Agency received
 regarding  the  site  were  from firms  conducting  environmental
 assessments on nearby properties.   These callers wanted to know the
 extent of contamination  at the site.   The Agency's  response was
 that  contaminated  soil  was  found  on properties  adjacent  to the
 Standard Auto Bumper  property  and  that  the extent of groundwater
 contamination had not been ascertained.

 C.   SUMMARY OF COMMENTS  RECEIVED DURING THE PUBLIC COMMENT PERIOD
     AND AGENCY RESPONSES

 EPA mailed the  Proposed  Plan to approximately  450 people in the
media, community,  and government  on August 3,  1992.   The public
 comment period on the Feasibility  Study and Proposed Plan for the
 site was held from  August  7  to September 6, 1992.   All comments
 from  the community were received during  the public meeting on

-------
August 18, 1992, at the Henry M. Filer Middle/Community School in
Hialeah, Florida.  The purpose of the meeting was to present EPA's
preferred  alternative.    This meeting  was  attended  by  three
citizens.   Part I  of this  section  addresses  the  community's
questions; Part  II addresses  the State's  comments  received after
the public meeting.  No comments have been received from the PRP.
A summary of the comments  or questions  and EPA's response to those
comments or questions is set out below.

Part I - Summary and Response to Local Community Concerns

1.   Who pays for the cleanup?

     EPA Response: The EPA Superfund provides the money; however,
     the fund is reimbursed.   EPA recovers the costs from the PRP,
     Standard Auto Bumper, through the justice system.

2.   At  the  public   meeting   a student  asked  how  stable  the
     solidified soils will be  and who's responsible for monitoring
     the material.

     EPA  Response:     It was explained  that  EPA performed  a
     treatability study on the contaminated soil and successfully
     solidified   the   material  as   shown   by  the   Toxicity
     Characteristic Leaching  Procedure.   This  procedure measures
     the  levels  of  contaminants  leaching  from  the  hardened
     monolith.  The leach levels for the solidified soil were below
     regulatory   levels,   indicating  the  solidification   was
     effective.   However,  EPA will perform another treatability
     test  prior  to  the  cleanup.     EPA   further  explained
     stabilization/solidification is a common and reliable remedy
     for metal-contaminated soil.  The process solidifies the soil
     into a mass very  similar to  concrete, preventing  the  soil
     contaminants  from  leaching  into  the  groundwater.    EPA
     considers this technology to be protective of the groundwater
     at the site.  It  was  added that  solidification will enhance
     natural   attenuation   of  groundwater  contamination,   and
     groundwater  sampling has indicated  much  lower levels  of
     contaminants during subsequent sampling events.  In conclusion,
     EPA explained that should this remedy be selected, they will
     monitor the remedy for the first  year following cleanup and
     then the State will assume responsibility.

Part II - Summary and Response to the State of Florida's Concerns

1.   Staff at  the  Florida  Department  of  Environmental Regulation
     (FDER)   disagreed with   EPA's   preferred  alternative  of
     excavation,  stabilization/solidification,  and  groundwater
     monitoring.    FDER   staff suggested  that  the  long-term
     monitoring was excessive  and that this requirement could be
     avoided by selecting  a comparable  alternative, excavation and
     offsite disposal.  This alternative did not require long-term

-------
     operation and maintenance (O&M).

     EPA Response:  The alternative EPA recommended at the public
     meeting (excavation,  onsite stabilization/solidification, and
     groundwater  monitoring)  was  favored  mainly  due  to  the
     Superfund statutory preference to employ treatment to reduce
     toxicity,  mobility,  or  volume  as  a  principal  element.
     However, EPA determined that the  staff at the State had valid
     concerns regarding the  burdensome  long-term O&M commitments
     necessary for the stabilization/solidification alternative.
     EPA  resolved that  at this  site it was  not preferable  to
     utilize treatment  to reduce toxicity, mobility,  or volume,
     because the  soil is  not a hazardous  waste  as defined by the
     Resource  Conservation  and   Recovery  Act  (RCRA)   and is  a
     relatively  small volume,  approximately 2500  cubic  yards.
     Excavation and offsite disposal was then selected as a remedy
     that utilizes permanent technologies and alternative treatment
     technologies, to the maximum extent practicable for this site.
     Up to five years of  groundwater  monitoring will be required
     following offsite disposal.   Excavation and offsite disposal
     was the remedy  selected in the  ROD, which contains further
     details of the process for selecting the remedial alternative.

D.  REMAINING CONCERNS

EPA  is  mainly concerned  with the  abatement. of  any groundwater
contamination  by  cleaning  up  the  soils,  the  source  of  the
contamination.  Future testing of the  groundwater during the RI/FS
for  operable  unit two, groundwater,  will define the  nature and
extent of any groundwater contamination.  EPA is  confident that the
selected alternative will minimize the need for groundwater pumping
and treatment.  EPA  plans  to keep the public  and local officials
informed of the activities  that  the Agency is  undertaking at the
site along with any new information that may involve the  site.  EPA
will issue  another  Proposed Plan for the  preferred groundwater
alternative for oper-able unit two.

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APPENDIX B

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 fi &.1.1  Qn-Site Worker Assumptions

 Exposure  factors  chosen  for  the on-site  worker  in conducting  this  exposure
 assessment come from  the  EPA  reference  documents  cited earlier and are listed
 below.

     .     Based upon information in  the  EPA document, Exposure Factors Handbook
           (EPA 1989b), the recommended BU for adults is 70 kg.  This, factor is
           also a Standard Default Exposure Factor for Commercial/Industrial Land
           use according to EPA guidance.  Therefore,  this factor is selected for
           use in assessing the exposure  to on-site workers.

     •      The Standard Default Exposure Factor for Commercial/Industrial Land use
           in  determining the exposure frequency (EF)  is 250 days/year according
           to  EPA guidance.    Therefore,  this factor  is  selected  for use  in
           assessing  the exposure  to  on-site workers.

     »     The Standard Default  Exposure Factor for Commercial/Industrial Land use
           in determining the exposure duration (ED) is 25 years according to EPA
          guidance.  Therefore, this  factor is  selected  for use in assessing the
          exposure to  on-site workers.

     •     For  noncarcinogenic  chemicals,  average  time  (AT)  is calculated  by
          averaging  365 days/year over  a period of 25 years to yield an AT  of
          9,125 days.  For carcinogens,  intakes are calculated by averaging the
          total cumulative dose over  a 70-year  lifetime, yielding a carcinogenic
          AT of 25.550  days.

     •     Available  exposed  skin area for  an  onsite  worker was assumed to  be
          limited to the  head  and hands.   According  to the  Exposure  Factors
          Handbook.   March  1990,  this  area  for an   adult   male  would  be
          approximately 2,000 cm2.

All exposure parameter values for the onsite worker scenario are listed in Table
6-1.   The intake factor  formulas for each pathway-specific exposure and the
intake factor  value  is included in Table 6-2.
                                       36

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                          TABLE 6-1
             TES VIII WORK ASSIGNMENT NO.  C04094
           FINAL BASELINE RISK ASSESSMENT FOR THE
                  STANDARD AUTO BUMPER SITE
                HIALEAH, DADE COUNTY, FLORIDA

PARAMETERS FOR CALCULATION OF INTAKE FACTOR FOR ONSITE WORKER
PARAMETER
BODY WEIGHT (BW)
EXPOSURE TIME (ET)
EXPOSURE FREQUENCY (EF)
EXPOSURE DURATION (ED)
INHALATION RATE (IR)
SOILS INGESTION RATE (IRSS)
SKIN SURFACE AREA (SA)
SOIL/SKIN ADHERENCE FACTOR (AF)
ABSORPTION FACTOR (ABS)
NONCARCINOGENIC AVERAGING TIME (NAT)
CARCINOGENIC AVERAGING TIME (CAT)
CONVERSION FACTOR (CF)
UNITS
kg
Hours
Days/Year
Years
m3/Workday
mg/Day
cm2
mg/cm
No Units
Days
Days
kg/rag
VALUE
70
8
250
25
20
50
2,000
1.0
0.001 (for Inorganics)
9,125
25,550
1/1.000.000
SOURCE
SDEF1
SDEF1
SDEF1
SDEF1
SDEF1
SDEF1
Professional
Judgement
NIR4G1
NIR4G3
RAGS*
RAGS*
RAGS*
1. Human Health Evaluation Manual, Supplemental Guidance: "Standard Default Exposure Factors",
March 25, 1991.
2. Professional Judgement justification is discussed in Section 6.4.1.
3. New Interim Region IV Guidance, February 11, 1992.
4. Risk Assessment Guidance for Superfund, Volume I, Human Health Evaluation Manual (Part A), Interim Final,
December 1989.
                              37

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 j /. i  9  Site Visitor

 For purposes of assessing potential health risks associated with exposure to a  site
 visitor,  the site visitor  is assumed to be a youth between the ages of 9 and 18.  The
 exposure  assumptions are itemized below.

     •     Based upon information in the EPA document, Exposure Factors Handbook  (EPA
           1989b) the average BW for male  youths between the ages of 9 and 18 is  50.5
           kg.   Based on professional  judgement,  this  BW will be utilized  for the
           site visitor  in assessing exposure.

     •     The site visitor is assumed to visit the  site for 8 hours/visit.   This
           assumption is a professional judgement based  upon the size of the site and
           the general  composition of the  site  layout and features.   Based  on
           professional judgement,  this EF will be utilized for  the site  visitor  as
           the  ET in assessing  exposure.

     •     The  site visitor is assumed to visit  the site 1 day/week for 9 months/year
           or 39 days/year.  Based on professional judgement, EF will be utilized for
           the  site  visitor in  assessing exposure.

     •      The  ED for the  ages  9 to  18  is 10 years.

     •      For noncarcinogenie chemicals, AT is  calculated by averaging 365 days/year
           over a period of 10 years to yield an AT of 3,650 days.  For  carcinogens,
           intakes are calculated by averaging  the total cumulative dose  over a 70-
           year lifetime, yielding a carcinogenic AT  of 25,550 days.
              /
     •      Available  exposed skin area for the site visitor was assumed to  be  limited
           to the head, hands,  forearms, and lower legs.  According to  the Exposure
           Factors  Handbook. March  1990,  this area for an  adult male  would  be
           approximately 5,300  cm2.

All values for the site visitor scenario  is  listed in Table 6-3.  The  intake factor
formulas for each pathway-specific exposure and the intake factor value is  included
in Table 6-4.
                                         39

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                                                   TABLE 6-3
                                      TES VIII WORK ASSIGNMENT NO. C04094
                                     FINAL BASELINE RISK ASSESSMENT FOR THE
                                           STANDARD AUTO BUMPER SITE
                                         HIALEAH, DADE COUNTY, FLORIDA

                          PARAMETERS FOR CALCULATION OF INTAKE FACTOR FOR SITE VISITOR
PARAMETER
BODY WEIGHT (BW)
EXPOSURE TIME (ET)
EXPOSURE FREQUENCY (EF)
EXPOSURE DURATION (ED)
INHALATION RATE (IR)
SOILS INGESTION RATE (IRSS)
SKIN SURFACE AREA (SA)
SOIL/SKIN ADHERENCE FACTOR (AF)
ABSORPTION FACTOR (ABS)
NONCARCINOGENIC AVERAGING TIME (NAT)
CARCINOGENIC AVERAGING TIME (CAT)
CONVERSION FACTOR (CF)
UNITS
kg
Hours
Days/Year
Years
mJ/Workday
mg/Day
cm2
rag/era
No Units
Days
Days
kR/mR
VALUE
50.5
8
39
10
20
100
5 , 300
1.0
0.001 (for Inorganics)
3,650
25,550
1/1.000.000
SOURCE
Professional
Judgement
Professional
Judgement
Professional
Judgement
Professional
Judgement
Professional
Judgement
Professional
Judgement
Professional
Judgement
NIR4C2
NIR4G2
RAGS3
RAGS1
RAGS1
1.  Professional Judgement Justification is discussed in Section 6.4.1.
3.  New Interim Region IV Guidance, February 11, 1992.
4.  Risk Assessment Guidance for Superfund, Volume I, Human Health Evaluation Manual (Part A),  Interim  Final,
    December 1989.
                                                       4.0

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fc L 1.3  Hypothetical Residential Exposure Assumptions

Exposure factors  chosen for the hypothetical  future residents in  conducting  the
hypothetical future  resident assumptions  will  consider both an adult  and  a  child
scenario.  The adult scenario will be considered for all exposure pathways cited in
Section 6.1.4-  The child scenario will be considered for the incidental ingestion
and dermal contact  of  soils pathway as these are considered  the  most  significant
pathway concerning  children.   This  exposure assessment  is  derived from  the  EPA
reference documents cited earlier and are as follows:

     .     The body weights for the adult and child is  70 kg and 15 kg, respectively,
          in accordance with the guidance in EPA's Human Health Evaluation Manual.
          Supplemental  Guidance.  "Standard Default Exposure Factors' (1991).

     .     The EF to  be utilized according to the EPA's Risk Assessment Guidance  for
          Superfund. Vol""an  Health Evaluation Manual  (Part A)   Interim
         Final  (1989),  the  90th percentile national upper-bound  time  at a single
         residence  is   30 years.   EPA guidance  states that  the  90th  percentile
         values   should be  used  if  95th  percentile  values  are unavailable.
         Therefore,  this value will be utilized as the ED in assessing  exposure to
         the hypothetical future resident.   The  ED for the child  will  be 6 years.

    •    Available  exposed  skin area for the adult hypothetical  future  residents
         will be assumed to  be limited  to the head, hands, forearms and  lower  legs.
         According  to the Exposure Factors  Handbook. March 1990,  this  area for an
         adult nale would be approximately 5,300  cm2.  The child will include  head,
         hands, arms and legs which would  be approximately  5,000  cm2.

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          For  noncarcinogenic chemicals,  the adult scenario's  AT  is calculated by
          averaging  365 days/year over a period of 30  years to yield an AT of 10,950
          days.   For  carcinogens,  intakes are  calculated by  averaging  the  total
          cumulative dose over a 70-year  lifetime,  yielding a  carcinogenic  AT of
          25,550  days.

          For  noncarcinogenic chemicals, AT for the child scenario is calculated by
          averaging  365 days/year over  a period of 6  years to yield an AT of  2,190
          days.   Carcinogenic intakes will not  be considered in the child scenario
          because the purpose in assessing carcinogenic risk is to evaluate the long-
          term effects of exposure.  Further, slope factors are based upon 70  years
          of exposure and therefore is inappropriate for the evaluation of children.

All values for the hypothetical future  residents are  listed in Tables 6-5 and 6-7.
The intake factor formulas for each pathway-specific exposure and the intake factor
value is included in Tables  6-6 and 6-8.
                                        43

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                                    TABLE  6-5
                       TES VIII WORK ASSIGNMENT NO. C04094
                             BASELINE RISK ASSESSMENT
                             STANDARD AUTO  BUMPER  SITE
                              HIALEAH,  DADE, FLORIDA
PARAMETERS FOR CALCULATION OF INTAKE FACTOR FOR ADULT HYPOTHETICAL FUTURE RESIDENT
PARAMETER
BODY WEIGHT (BU)
EXPOSURE TIME (ET)
EXPOSURE FREQUENCY (EF)
EXPOSURE DURATION (ED)
INHALATION RATE (IR)
SOILS INGESTION RATE (IRSS)
SKIN SURFACE AREA (SA)
SOIL/SKIN ADHERENCE FACTOR (AF)
ABSORPTION FACTOR (AfiS)
NONCARCINOGENIC AVERAGING TIME (NAT)
CARCINOGENIC AVERAGING TIME (CAT)
CONVERSION FACTOR (CF)
UNITS
kg
Hours
Days/Year
Years
mJ/Workday
rag/Day
cm2
mg/cm2
No Units
Days
Days
kR/mR
VALUE
70
24
350
30
20
100
5,300
1.0
0.001 (for Inorganics)
10,950
25,550
1/1,000,000
1. Human Health Evaluation Manual, Supplemental Guidance: "Standard Default Exposure Factors",
2. Professional Judgement Justification Is discussed In Section 6.4.1.
3. New Interim Region IV Guidance, February 11, 1992*
4. Risk Assessment Guidance for Super fund, Volume I, Human Health Evaluation Manual (Part A),
December 1989.
SOURCE
SDEF1
SDEF1
SDEF1
SDEF1
SDEF1
SDEF1
Professional
Judgement
Professional
Judgement
NIR4G1
RAGS*
RAGS*
RAGS*
March 25, 1991.
Interim Final,

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                                                   TABLE 6-7
                                      TES VIII WORK ASSIGNMENT NO. C04094
                                     FINAL BASELINE RISK ASSESSMENT FOR THE
                                           STANDARD AUTO BUMPER SITE
                                         HIALEAH, DADE COUNTY, FLORIDA

               PARAMETERS FOR CALCULATION OF INTAKE FACTOR FOR CHILD HYPOTHETICAL FUTURE RESIDENT
PARAMETER
BODY WEIGHT (BW)
EXPOSURE TIME (ET)
EXPOSURE FREQUENCY (EF)
EXPOSURE DURATION (ED)
INHALATION RATE (IR)
SOILS INGESTION RATE (IRSS)
SKIN SURFACE AREA (SA)
UNITS
kg
Hours
Days/Year
Years
m'/Workday
mg/Day
cm2
VALUE
15
24
350
6
20
200
5,000
SOURCE
SDEF1
SDEF1
SDEF1
SDEF1
SDEF1
SDEF1
Professional
SOIL/SKIN ADHERENCE FACTOR (AF)           mg/cm2


ABSORPTION FACTOR (ABS)                   No Units

NONCARCINOGENIC AVERAGING TIME  (NAT)      Days

CONVERSION FACTOR (CF)	kg/rag
1.0


0.001 (for Inorganics)

2,190

1/1.000.000       	
Judgement

Professional
Judgement
NIR4GJ

RAGS*

RAGS*
1. Human Health Evaluation Manual, Supplemental Guidance:  "Standard Default Exposure Factors", March 25,  1991.
2. Professional Judgement-justification is discussed in Section 6.4.1.
3. New Interim Region IV Guidance, February 11, 1992
4. Risk Assessment Guidance for Superfund, Volume I, Human Health Evaluation Manual  (Part A), Interim Final,
   December 1989.

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APPENDIX C

-------
                    r»
                    P/-'
Gasoline Spill
(•/G
                          Br.
                                          ppre   Cd
                                      <77 ppm   Hg
                                     <155 ppm
                                      >
TZil ':r
<100 ppn
<100 ppa
<50,000 ppm
i ' r
0.' :



Cil Spill
J!3t;D fO?. SPZCI-IC  5:Tv.'.
       ^..i.IiiS OF SOIL  TO  BE DISPOSED Or K.1/.
       -.'- ALTSPNATIVES.
       :LS MUST NOT BE A IiA7.A?.I;C-.'J  l/AsTS  A:  ..
               •! (0/G)  pay  fca iv:/-aa?;-d ti :v:
            Art as.
      (Total Recoverable P^troJeun  Hydroc = rb.-/..
      •"=rdous wastes nu^t  b-3  disposed c5 d :.
      '•i'.^r cont.ajninateci t'.ils  viJ.l  b>i :V;31 •.!'•".i
                                                             ' .- THE
                                                               •;FS 261.
                                                              .  D: Velllisid

                                                              .. Ksthod S073.
                                                             •- ?o facility.
                                                             :'.-' disposal at
                          l  i •
                                                          POOR QUALITY
                                                              ORIGINAL

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