PB94- 964072
EPA/ROD/R04-94/205
February 1995
EPA Superfund
Record of Decision:
Airco Plating Company
(O.U. 1), Miami, FL
10/1/1993
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RECORD OF DECISION
DECLARATION
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, ,
SITE NAME AND LOCATION
Airco Plating Company, Inc.
Miami, Dade County, Florida
STATEMENT OF BASIS AND PURPOSE
This decisiondoc~ent presents the selected remedial action for
the Site noted above. 'The remedy was chosen in accordance with
the, Comprehensive Environmental Response, Compensatiqn and
Liability Act of 1980 (CERCLA), as amended by the Superfund
AIDendments and Reauthorization Act of 1986 (SARA), and to the
extent practicable, the National Oil and HazardouS Substances
Pollution Contingency Plan, (NCP). This decision is based on the
administrative record for this Site. '
The State of Florida, as represented by the Florida Department of
Environmental Protection, has been the support agency during the
Remedial Investigation (RI) .arid Feasibility Study (FS) process for'
the Airco Plating Company, Inc. Site. In accorda~ce with 40 CFR
300.430, FDEP, as the, support agency, has provided input, during
this process. Based upon discussions with FDEPi it 'is anticipated
that the State of Florida will concur with the groundwater
treatment to reduce organic and inorganic contaminant levels, soil
vapor extraction to reduce organic contamination, deed
restrict,ions, and soil capping to reduce the threat posed by direct
contact with soil. However, FDEP has stated a preference for
additional soil treatment prior to capping the Site. A formal
letter of concurrence has not been received to date.
ASSBSSMENT OF THB SITE
Actuai or threatened releases. of hazardous' substances from this
Site, if not addressed by implementing the response action selected
in this Record of Decision (ROD), may present an imminent and
substantial endangerment to public heal'th, welfare, or the
environment. '
DESCRIPTION OF THE SELECTED REMEDY
This remedy addresses the contaminated soil and groundwater at the
Site. This remedy addresses the most mobile threat at the Site by
extraction and treatment of groundwater'c'ontaminated with organic
compounds. " ,
In addition, soil contaminated with tetrachloroethylene, which is
the source of organic contaminants in Site groundwater, will be
treated with soil vapor extraction. Metals contaminated soil will
be capped to, reduce exposure to the soil contaminants and to reduce
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the potential for leachate generation.
The major components of the remedy include:
-Soil vapor extraction of organic compounds, such as PCE
concentrations in excess of 90 ppm, that are preser.: in Site soils
to a depth of 5-6 feet below land surface, or just above the water
table, whichever is lower.
-Placement of a RCRA-type cap over soil with cadmium concentrations
in excess of 73 ppm and PCE concentrations in excess of .060 ppm.
-Institutional controls, including deed restrictions, to preserve
integrity of the cap and to prohibit activities that are not
compatible with the remedy.
-Extraction of contaminated groundwater with subsequent treatment
by air stripping at the Site; and
-Discharge of treated water to the POTW or to the surficial aquifer
via a recharge gallery in accordance with all applicable
regulations and other Performance Standards.
-Evaluation of the need for treatment of inorganics in groundwater
will be conducted during the Remedial Design.
-Modeling of air emissions and analysis of actual air .emissions
from the air stripping tower and the soil vapor extraction system
will be conducted during the Remedial Design in order to determine
the need for air emission control equipment.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that are
legally applicable or relevant and appropriate to the remedial
action, and is cost-effective. This remedy satisfies the statutory
preference for remedies that employ treatment for the reduction of
toxicity, mobility, or volume as a principal element and utilizes
permanent solutions and alternative treatment technologies to the
maximum extent practicable for this Site.
Because the remedy will result in hazardous substances remaining
on-site, a review will be conducted within five years after
commencement of remedial action to ensure that the remedy continues
to provide adequate protection of human health and the environment.
~{Y)7~
Patrick M. Tobin,
Acting Regional Administrator
/0 -1--9.5'
Date
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TABLE OF CONTENTS
SECTION
TITLE
PAGE
1. 0 Site Background................................. . . .1
2.0 Site History and Enforcement Activities....~..... ..1
3.0 History of Community Relations~....................4
4.0 Scope and Role of Action...........................5
5.0 Summary of Site Characteristics................... 5
5.1 Site Geology......................... '. . . . . . .. 5
5 .2 Hydrology.................................... 5
5.3 Soil contamination.....:..................... 6
5.4 Groundwater Contamination.................. ..10
6.0' Summary of Site Risks. . . . . . . . . . . . . . . . . . . . . . . . . . . . .13,
6.1 Identification of Contaminants of Concern....13
,6.2 Exposure Assessment Summary...~..............14
~.3 Toxicity Assessment.............~............15
6.4 Summary of Risk Characterization........... ..16
6.5 Environmental Risk.......................... .19
6~6 Risk Uncertainty........................... .20
7 . 0 Surnrnary of ,Al ternati ves . . . . . . . . . . . . . . . . . . . . . . . . . . .20
8.0 Comparative Analysis of Alternatives.......~.."...28
Overall Protection............................... .28
Compliance with ARARs. . . . . . . . . . . . . . . . . .. . . . . . . . . . . .29
Long term effectiveness and perman~nce.......... ..29
Reduction of toxicity, mobility, or' volume',' ,
through treatment..... . . . . . . . . . . . . . . . . . .. . . . . . . .. 33
Short term effectiveness......~...................34
Implementability................................. .34
Cos t s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
State Acceptance.... . . . . . . . . . . . . . . . .'. . . . . . . . . . . : . .35
Community Acceptanc~.. . . . . . .. . . . . . .. . . . .. . . . . . . . . .35
Synopsis of CQmparative Analysis.,............. .'. .36
9.0 S,elected Remedy.....,.. . . .' .. . . . . . . .. . . . . . . . . . . . . . . . . .37
A. Source Control............ .'.... .'~. .'.......... :37
, A.1 Components of Source Cont~ol..... '. . . . .'. ~ 37
A.2, Treatment of in-situ m'aterial...........38
A.3' Performance Standards................... 39
,B. Groundwater Remediation...................... .42
B.! ComPonents of Remediation.....;.........42
B.2 Extraction, Treatment, and Discharge of '
Groundwat'er. . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
B.3 Performance Standards.................. .43
10.0 Statutory Determinations........ .'................ .48
10.1 Protection of Human Health, .
and the Environment...,... . . . .; . . . . . .. . . .. . '. . . .48 .
Compliance with ARARs.........~......~......48'
Cost effectiveness..........................49
Utilization of Permanent Solutions
or alternative treatment technologies
to the maximum extent practicable......... ..49
10.5 Preference for treatment....................49
11.0 Explanation of Significant Changes.............~..49
10.2 '
10.3
10.4
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TABLE OF CONTENTS (cont.)
APPENDIX A: Administrative Record Index
APPENDIX B: Responsiveness Summary
APPENDIX C: Risk Calculation Constants/Calculations
TABLES
Number
Title
Page
1
2
3
4
5
Contaminant Concentrations in Soil. """ .... ..9
Contaminant Concentrations in groundwater.....12
Summary of Baseline Risks.... """ ....... ... .18,
Location Specific ARARs. ...... """ ....... ....30
Action & Chemical Specific ARARs... """"" .31
FIGURES
Number
, Title
Page
1
2
3
4
Site Location Map..............................2
Site Layout....................................3
Soil Sampling Locations. . . . . . . . . . . . . . . . . . . . . . . .7
Location of Groundwater Monitoring Wells..... .11
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'THE DECISION SUMMARY
SITE LOCATION AND DESCRIPTION
1.0
The Airco Plating Company, Inc. Site ("Site") is principally
located at 3650 N.W. 46th Street, Miami, Florida. The Site is
close to the i~tersection of N.W. 46th Street and N.W. 36th
Avenue which is a just over one mile northeast of the Miami
International Airport (see Figures 1 and 2) .
rhe Site occupies approximately two acres in a predominantly
industrial/commercial area and is surrounded by other activ.e
bus,inesses. There is a mobile home park located about 300 feet
, south of the Site. '
The topography is relatively flat in the vicinity of the Site with
a land surface elevation of about 8 feet above mean sea level.
, "
The Miami Canal is. located approximately 2/3 of a mile southwest
of the Site and is the only major surface water body in the, '.
vicinity of the Site. .
The Site is immediately underlain by the Biscayne AqUifer which is
approximately,100 feet thick in the vicinity of the Site. The
Biscayne Aquifer.supplies all municipal water supply systems from.
SOuth Palm Beach County southward~' . ' ,
. .
The Site is an operational electroplating facility owned and
operated by Airco Plating Company, Inc. Primarily steel, copper,
and brass items are plated with zinc, but the facility also plates
various items with brass, cadmium, chromium, copper, nickel, and
tin. Cyanide, caustic compounds and acids are addition~l
chemicals used in the plating process. . Tetrachloroethene, a
common industrial solvent, has been used to clean'parts prior to
plating. " .
, 2.0
SITE HISTORY AND ENFORCEMENT ACTIVITIES
, .
Airco Plating began its operations at the Site in the mid~1950's.
From approximately 1957 to 1972, Airco, by permit from the Florida
State Board of Health, utilized three ponds to discharge
wastewater, after some treatment, following electroplating
operations. The treatment process included cyanide destruction,
, chromium reduction and pH neutraliza~ion.
According to Airco Plating, the center pond was used by Airco from
abou~1957 until 1972 or 1973. In 1962, Airco leased a parcel of
property immediately south of the southwest corner of Airco's
current property boundary. This leased parcel was utilized as a
pond for about 10 years. The northw~st pond was used from the
late 1960's until about 1972 or 1973.
1
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A/RCO PLA llNG CO., INC.
3650 N.W. 4-6th STREET
MIAMI. FLORIDA
Figure 1:
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An EPA inspection during 1971 noted the use of the seepage ponds
and reported that some wastewater was discharged to the ponds
without tr~atment. Between June 1972 and January 1973, Airco
Plating received at least three notices regarding wastewater
discharges that exceeded Dade County standards. In February 1973,
Airco was ordered to pump out the ponds and make necessary changes
to the treatment system so that it would comply with regulations.
Sometime after June 1973, Airco ceased use of the ponds and began
to discharge the treated wastewater to the Miami municipal sewer.
In 1981, the treatment facility at Airco was upgraded to separate
sludge from the treated effluent before it was discharged to the
sewer. The sludge was collected on-site and periodically shipped
offsite for disposal.
u.S. Environmental Protection Agency investigations at the Site
were conducted in July 1985, December 1986, and January 1987. In
February 1990 the Site was listed on the National priorities List
as defined in Section 105 of the Comprehensive Environmental
Response, Compensation and Liability Act (CERCLA).
During July 1990, Airco Plating and other Potentially Responsible
Parties (PRPs) received Special Notice Letters for the Remedial
Investigation and Feasibility Study (RIfFS). On November 8, 1990,
Airco Plating Company, Inc. signed an Administrative Order by
Consent for the RIfFS.
The RI report was finalized during February 1993 along with the
Baseline Risk Assessment prepared by EPA. The RI report
documented the presence of primarily metals, cyanide, and
tetrachloroethylene (also known as perchloroethyleneor PCE) in
the areas of the former seepage ponds, and an area of excessive
PCE and metals levels adjacent to the main building. In addition,
PCE was found in excessive levels in shallow groundwater from a
well near the location of the excessive PCE soil concentrations.
PCE and related by-products were found in deeper portions of the
aquifer at the edge of the Site and also downgradient of the Site.
Cadmium exceeded groundwater standards in the shallow groundwater
and, to a lesser extent, in intermediate depths of the aquifer.
3.0
HISTORY OF COMMUNITY RELATIONS
Public announcements for the Proposed Plan comment period and
public meeting appeared in the Diaros Las Americas on July 18 and
the Miami Herald Neighbors on July 20. The 30-day comment period
was held from July 19 to August 18 and the public meeting was held
on August 2 at the Caleb Business Center in Miami. Over 100
Proposed Plan fact sheets were mailed to local businesses,
citizens, environmental groups, and local and state agencies.
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An availability session was held at the Caleb Center prior to the
start of the RI/FS in July 1990. Brief fact sheets were mailed
periodicaIly during the course of the RI/FS.
4.0
SCOPE AND ROLE OF ACTION
The planned actions for this Site address both soil and
groundwater contamination. The planned soil cleanup for metals,
including cadmiUm and nickel, and organic compounds, such as PCE,
is necessary to prevent further migration of contaminants. to
groundwater. The planned groundwater cleanup for metals and, ,
organics is necessary to protect the Biscayne Aquifer, the sole
source of drinking water in Dade County. The ROD further'
describes this combined action and is the only ROD anticipated for
this Site. ' ,
5.0
SUMMARY OF SITE CHARACTERISTICS
5.1
Site Geology
The surface sediments are made up of organic rich top soil in
areas of no asphalt or concrete cover and limerock base fill where'
asphalt cover 'occurs.. Below the surficial soils, the Site is '
underlain bya 4Q to 45 feet thick layer of fine to ,
coarse-grained, moderately sorted, unconsolidated quartz sand
which contains randomly distributed ,limestone rubble increasing
with depth. The sand ranges in color from a white to a light
brown. The sand unconformably overlies a coral limestone which'
ranges in depth from 45 to 55 feet below land surface (bls). Sand
has filled some of the voids and open spaces within the limestone.
Crystalline calcite,also occurs at this depth.
From 52 to 65 feet beneath the Site is a fairly dense, fine
grained limestone containing abundant solution channels and voids
which may be filled with sand. At approximately 65 to 70 feet
, bls, this limestone grades into a less dense ~oarse grained shelly
limestone which continues to at least 75 feetbls. Both ,are buff,
, tan to white in color. These sands and limestones are interpreted
to be constituents of the Pamlico, Key Largo and Fort Thompson
Formations, respectively.
On-site soil samples, collected at a depth of about three feet,
indicated that permeability ranged between 0.00719 to 0.0166
em/see, pH ranged between '7.8 to 8.7, oil and grease ranged
between 10 to less than 1800 mg/kg, sulfate ranged between 140 ,
mg/kg to 370 mg/kg, 'calcium (as CaC03) ranged between 1.2% to
, 6.3%, and porosity ranged between, 31.51%, to 56.12%. '
5.2 Site Hydrology
The Site is immediately underlain by the Biscayne Aquifer. The
unconfined aquifer is approximately 100 feet thick in the vicinity
5
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of the Site. It is composed of sand, limestone and sandstone.
Groundwater in the Biscayne Aquifer flows through pore spaces
between grains of sand, solution channels and joint systems in the
limestone, and secondary openings and pore spaces in the
sandstone.
The Biscayne Aquifer supplies all municipal water supply systems
from South Palm Beach County southward. It has been stated that
the Biscayne Aquifer "is the most productive aquifer of the
shallow nonartesian aquifers in the area and is one of the most
permeable in the world" (Klein and Hull, 1978).
The water table is found at the Site at depths of about 4.5 to 6
feet bls. Groundwater flow direction varies from the southeast to
the southwest. The flow direction in the shallow or intermediate
depths of the aquifer may be affected by pumpage of two industrial
wells at the Site, which, according to Airco, pump approximately
15,000 gallons per day, five days a week.
Hydraulic conductivity of the aquifer was measured by two
different methods, slug tests and pump tests. Hydraulic
conductivity values ranged from 119.73 to 398.02 gpd/ft2 (gallons
per day per square foot). Transmissivity, which is equal to
hydraulic conductivity times the aquifer thickness, was estimated
to have a minimum value of 8,381 gpd/ft.
The maximum range of horizontal groundwater velocities in the
shallow aquifer, based on the pump test and slug test data, is
.0384 ft/day to .362 ft/day.
5.3
Soil Contamination
Various metals, cyanide, PCE and occasionally, trichloroethene,
were detected in soil ranging in depths from one-half foot bls to
16 feet bls (see Figure 3 - Soil Boring Locations). The metals
detected most often at the highest concentrations were cadmium,
chromium, copper, lead, nickel, and zinc. Generally, the higher
concentrations are found in areas used formerly as percolation
ponds for industrial wastewaters (see Figure 2). However, there
is also a limited area outside the boundaries of the former ponds,
that contains the highest levels of PCE in soil. Soil
contaminants are summarized in Table 1.
As can be seen from the data presented in Table 1, various
chemicals associated with electroplating operations are present at
elevated concent,rations in Site soils. PCE, cadmium, chromium,
cyanide, copper, lead, nickel, and zinc are present at
concentrations much above background levels detected just north of
the Site. The highest concentrations are generally found in the
first five feet of soil, but were detected at reduced
concentrations as deep as 16 feet. The soil sampling focused on
the former percolation ponds and most of "the contaminants were
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Locations of All Soil Sample Borings, AircoPlating
eo.pany, Inc., Miami, Florida.
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detected in all of the surface soil samples. However, there was
sufficient decrease in the concentrations to approximate the
extent of the contaminated areas.
Other contaminants, including acetone, chloroform,
trichloroethene, bis (2-ethylhexyl) phthalate, 4,4'-DDT, and 4,4'-
DDE, and antimony were detected in single soil samples. However,
given the low frequency of detection and the low detected levels,
those contaminants are not considered significant.
8
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TABLE 1:
CONTAMINANTS IN SURFACE SOIL
Contaminant Range of Detected Average Background Detection
ConceI).trations (ppm) Concentration Level Frequency
Acetone .088 .088 Not detected 1/1
(00)
Chloroform .016 .016 00 1/18
Tetrachloroethylene '. .009 - '230 19.6 00 12/18
(PCE)
TriChloroethylene .010 .010, ND 1/18
Bis. (2-ethylhexyl) .310 .310 00 1/1
phthalate
4 , 4 ' - DDT .058 .058 00 1/1
4,4'-DDE .029 .029 00 1/1
Cyanide 1.8 - 3,100 858 ND 15/18
Arsenic 4 4 00 1/1
.Cadmi um 1 - 1,400 452 00 18/18
Chromium 9.6 - 5,300 1,911 ND 18/18
Copper 2 -1,200 258 23 18/18
Lead 1.3 - 3,700 281 26 18/18
Nickel '. 18 - 760 244' ND 15/18
Zinc 15 - 13,700 4,589 00 18/18
Antimony 39.6 . 39.6. 00 1/1
9: .
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5.4
Groundwater Contamination
Shallow groundwater quality at the Site was characterized by data
from monitoring wells with depths ranging from 14 to 20 feet.
Shallow groundwater, within the boundaries of the Airco Plating
property, is primarily contaminated with cadmium and volatile
organic compounds (VOCs) such as PCE. Three wells (APS 5, 6, and
10) contained cadmium at levels ranging from 50 to 67 ppb, which
is greater than the federal standard for cadmium. Well APS-10
contained highly elevated levels of PCE, at least 4000 ppb, which
is much greater than the state standard for PCE.
Intermediate groundwater quality was characterized by data from
monitoring wells with depths of approximately 45 feet. Cadmium
and PCE exceeded their respective MCLs in an intermediate well
located adjacent to the former Pond 2. Pond 2 was located on a
parcel of land immediately south of Airco Plating's fence line.
PCE exceeded its MCL in wells located approximately 120 feet
south of the Airco Plating property (see Figure 4 - Monitor Well
Locations) .
Deep groundwater quality was charatterized by data from
monitoring wells with depths of approximately 75 feet. PCE
exceeded its MCL in the four wells located on the southern edge
of the Airco Plating property and about 120 feet south of the
property boundary.
The sampling results are consistent with the presence of a PCE
plume which has its origins on the Site and which has migrated at
least 120 feet south of the Site. PCE and related VOCs were
detected at elevated levels at various depths in groundwater at
the Site. The highest concentrations are found in shallow
groundwater while the most extensive migration has been in the
deeper portions of the aquifer as evidenced by reduced
concentrations detected in several intermediate and deep wells.
Also, PCE concentrations decrease with increased distance south
of the Site. Groundwater contaminants are listed in Table 2.
10
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FIGURE 4:
/\Pl-Sl
/\PO-OJ &SS /\PS-OI
p- !
()
~I .
>1
I ~I
I~I
I I.
II
i :
I i
.1 I
I .
I. I.
I I
N.W. 46TH STREET
I
I
L-.J
I
o
i~-~lT I J~~~5T I
I' /\PS - 1'$ , /
rt @ ,
/\FS-05is U OCS-02 I
I I fO
/\P~-05 /\P0-02
1$$$ I\PD-03
APS-02 ... S ,
/\PI -02L-J 1\ SAP! -03
I <7". S.~
I /\PS-07 - /\PS-03
SAP! -08
~. APO~Qr
~
I
N
,
,
1
-'
APO -09 AP! -09
I S$
SCI\LE
es
!70 FEET
j SAPI-DI
@ DeS-O!
() P-I "
EXPL"NA T I C3'J
~/\ TER WELL LOC" T I ON AMJ
EXISTING DADE COUNTY COMPLIANcE
WELL LOCA T ] ON Af\C) NJMBER.
P [E2Dl"ETER LOC" T i ON Af\D NUMBER.
Monitor Well and Piezometer. Locations, Airco Plating Company Inc.,
Miami, Florida.. .
-------
TABLE 2:
CONTAMINANTS IN GROUNDWATER
Contaminant Range of Detected Average of Detected Background Detection Groundwater
Concentrations Concentrations Concentration Frequency Standard
(ppm) (ppm)
Acetone .007 .007 ND 1/3 I NA
Chloroform .001 - .21 .008 ND 5/21 .100
1,1 Dichloroethylene .011 .011 ND 1/21 .007
Cis/trans 1,2 .07/.100
Dichloroethylene .004 - .27 .042 .004 11/21
Tetrachloroethylene .0046 - 4.0 2.5 ND 10/21 .003
(PCE)
Trichloroethylene .017 - .042 .016 NO 6/21 .003
Vinyl Chloride .005 - .1 .024 .005 .001
Bis (2 -ethylhexyl) .004 - .005 .0045 ND 2/3 NA
phthalate
Cyanide .011 - .024 .015 .010 3/21 .200
Cadmium .009 - .067 .045 <.005 5/21 .005
Chromium .010 - .26 .047 <.005 13/21 .100
Copper .0026 - .049 .026 <.02 9/21 1.3
Lead .005 - .13 .025 .13 6/21 .015
Nickel .005 - .15 .064 .053 9/21 .100
Zinc .02 - .68 .2 ,07 13/21 5.0
ppm pares per mlillon Nu=-noe aeeeceea JA' noe appllcaOle or a roprlaee
pp
12
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II
i I
6.0
SUMMARY OF SITE RISKS
~ERCLA directs EPA to conduct a baseline risk assessment to
determine whether a Superfund Site poses a current or potential
threat to human health and the environment in the ~bsence of any
remedial action. The baseline risk asses~ment provides the basis
for taking action and indicates the exposure pathways that need'
to be addressed by the remedial action. It serves as the
baseline indicating what risks could exist if no action were
taken at the Site. This section of the ROD reports the results
of the baseline risk assessment conducted for this Site.
6.1
Contaminants of Concern
. .
. . .
The chemicals measured in the various environmental media. during
the RI were included in this di~cussion of the site risks if the
results of the risk assessment indicated that a contaminant might
pose a significant current or future risk or contribute to a
cumulative risk which is significant. The criteria for a
significant risk was a carcinogenic risk level above the
acceptable risk range, i. e., 1x10-4 to 1x10-6, or a hazard
quotient (HQ) greater than 1.0 (unity). .
The exposure point concentrations for each of the chemicals of
concern and the expQsure assumptions for each pathway were used
to estimate t.he chronic daily intakes for the potentially'
complete pathways. The ,exposure point concentrations are based
on either the calculated 95% Upper Confidence Limit of the
. arithmetic mean or the maximum concentration detected during
sampling. If the calculated UCL exceeded the maximum level
measured at the Site, then the maximum concentration detected was
used to. represent the reasonable maximum concentration.' The
chronic daily ,intakes were then used in conjunction with cancer
slope factors and noncarcinogenic reference doses to evaluate
risk. . . .
. .
'The baseline 'risk assessment considered current commercial land
use and future residential land use. There is a mobile home park
about 250 feet south of the'Site~ but commercial operations are
between the Site and the mobile home park. Future residential
use ot the Site is evaluated in the risk assessment. However,
given the current Comprehensive Development Master Plan .for Dade
County, revised October 1992, and Site visits. by EPA, it .is not
anticipated that this use will occur in the immediate future.
Groundwater at the Site is currently used for industrial
purposes. Groundwater at the mobile home park'is currently used.
fO.r irrigation of lawns. Groundwater in the vicinity of the Site
could be used in the future for drinking water since the aquifer
.is the only Source of drinking water in Dade County.
13
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6.2
Exposure Assessment
Whether'a chemical is actually a concern to human health and the
environment depends upon the likelihood of exposure, i.e. whether
the exposure pathway is currently complete or could be complete
in the future. A complete exposure pathway (a sequence of events
leading to contact with a chemical) is defined by the following
four elements:
.
A source and mechanism of release from the source,
.
A transport medium (e.g" surface water, air) and
mechanisms of migration through the medium,
.
The presence or potential presence of a receptor at the
exposure point, and
.
A route of exposure (ingestion, inhalation, dermal
absorption) .
If all four elements are present, the pathway is considered
complete.
The three major constituent release and transport mechanisms
potentially associated with the Site are as follows:
.
.
.
The infiltration of precipitation through the affected
soils and the percolation of the resulting leachate
into subsurface soils and groundwater, followed by
groundwater transport.
Release of contaminated surface soil through wind
erosion. Surface soils could be suspended in air and
transported from their source by the wind.
Release of volatile compounds from soils and waste to
the atmosphere. These constituents could be
transported and dispersed by the wind.
Because the vegetation and ground cover present at the Site will
impede volatilization and wind erosion, exposure to constituents
in air, either as vapor or adsorbed to dust, is not considered
significant at the Site under current land use conditions. The
presence of vegetation also reduces direct contact with surface
soils by Site visitors. .
An evaluation was undertaken of all potential exposure pathways
which could connect chemical sources at the Site with potential
receptors. All possible pathways were first hypothesized and
evaluated for completeness using the above criteria. Three
current potentially complete exposure pathways and five future
exposure pathways remained after screening. The current pathways
14
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represent exposure pathways which could exist under current Site
conditions while the future pathways represent exposure pathways
which coula exist, in the future, if the current exposure
conditions change. Exposure by each of these pathways was
mathematically modeled using generally conservative assumptions.
The major assumptions used in the risk calculations are presented
in Appendix C. .
The potential current or future pathways for industrial use are:
.
ingestion of surface soil by a trespasser or an on~ite
worker;
.
absorption through the skin from surface soil by a
tre$passer or an onsite worker;
.
inhalation of fugitive dust and VOCs by a trespasser .or
an onsite worker .
The potential future pathways for residential use are:
.
ingestion of surface soil by an onsite resident;
.
. .
. absorpt~on through the skin from su~face soil by an
onsite resident; .
: .
ingestion of groundwater by an onsite.resident;
.
inhalation of VOCs in groundwater by an onsite resident
during showering;
inhalation of airborne .dust by an onsite residents;
.
The baseline risk assessment i~ based on. the reasonable maximum
exposure (RME) that may be encountered during the various Site
, use scenarios. The intent of the RME is to estimate a
conservative exposure case ( i.e., well above the. average case)
that is still within the range ,of possible exposures..
6.3
Toxicity Assessment
Toxicity values are used in conjunction with the results of the
exp'osure assessment to characterize'Site risk. EPA has developed
critical toxicity values for carcinogens and noncarcinogens.
Cancer slope factors (CSFs) have been developed for estimating
excess .lifetime cancer risks associated with exposure to
. potentially carcinogenic chemicals. CSFs" which are expressed in
units .of (mg/kg/day)-l, are multiplied by the estimated intake of
a potential carcinogen, in mg/kg/day, to provide an upper-bound
estimate of the excess lifetime cancer risk associated with
exposure at that intake level. The term "upper bound" reflects
the conservative estimate of the risks calculated from the CSF.
15
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Use of this conservative approach makes underestimation of the
actual cancer risk highly unlikely. CSFs are derived from the
results of-human epidemiological studies or chronic animal
bioassays to which animal-to-human extrapolation and uncertainty
factors have been applied.
Reference doses (RfDs) have been developed by EPA for indicating
the potential for adverse health effects from exposure to
chemicals exhibiting noncarcinogenic effects. RfDs, which are
expressed in units of mg/kg/day, are estimates of lifetime daily
exposure levels for humans, including sensitive individuals.
Estimated intakes of chemicals from environmental media can be
compared to the RfD. RfDs are derived from human epidemiological
studies or animal studies to which uncertainty factors have been
applied (e.g., to account for the use of animal data to predict
effects on humans). These uncertainty factors help ensure that
the RfDs will not underestimate the potential for adverse
noncarcinogenic effects to occur.
6.4
Risk Characterization
Human health risks are characterized for potential carcinogenic
and noncarcinogenic effects by combining exposure and toxicity
information. Excessive lifetime cancer risks are determined by
multiplying the estimated daily intake level with the CSF. These
risks are probabilities that are generally expressed in
scientific notation (e.g., 1x10-6). An excess lifetime cancer
risk of 1xlO-6 indicates that, as a plausible upper boundary, an
individual has a one in one million additional (above their
normal risk) chance of developing cancer as a result of
Site-related exposure to a carcinogen over a 70-year lifetime
under the assumed specific exposure conditions at a Site.
EPA considers individual excess cancer risks in the range of
lx10-4 to 1xlO-6 as protective; however the 1x10-6 risk level is
generally used as the point of departure for setting cleanup
levels at Superfund sites. The point of departure risk level of
lx10-6 expresses EPA's preference for remedial actions that
result in risks at the more protective end of the risk range.
The health-based risk levels for the Site are shown in Table 3.
Potential concern for noncarcinogenic effects of a single
contaminant in a single medium is expressed as the hazard
quotient (HQ) (or the ratio of the estimated intake derived from
the contaminant concentration in a given medium to the
contaminants's reference dose). A HQ which exceeds unity (1)
indicates that the daily intake from a scenario exceeds the
chemical's reference dose. By adding the HQs for all
contaminants within a medium or across all media to which a g1ven
population may reasonably be exposed, the Hazard Index (HI) can
be generated. The HI provides a useful reference point for
gauging the potential significance of muitiple contaminant
exposures within a single medium or across media. An HI which
16
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exceeds unity indica~es that there may be a concern for potential
health effects resulting from the cumulative exposure to multiple
contaminant.s within a s'ingle medium or across media. The HIs for
the Site are shown in Table 3. Chemical specific risk.
calculations and exposure point concentrations are summarized in
Appendix C. ..
17
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TABLE 3:
Summary of Cumulative Potential Cancer Risks
and Non-Carcinogenic Hazard Indices
Land Use/Receptor Pathway Noncarcinogenic Carcinogenic
Risk (Hazard Index) Risk
Current Cormnercial Fugitive Dust 3 x 10-4 4.4 x 10-8
Onsite Worker Inhalation
Ingestion of Soil 1.1 x 100 5.1 x 10-9
Dermal Contact 2.1 x 10-1 1.0 x 10-8
with Soil
TOTAL: 1. 31 x 10°
Current Cormnercial Fugitive Dust 6 x 10-s 3.8 x 10-9
Trespasser Inhalation
Ingestion of Soil 8.6 x 10-1 4.3 x 10-9
Dermal Contact 2.2 x 10-1 1.1 x 10-8
with Soil
TOTAL: 1. 08 x 100 2.0 x 10-8
Future Residential Fugitive Dust 1.8 x 10-3 2. 3xl0-s
(Adult) Inhalation
Ingestion of Soil 5.8 x 100 1.1 x 10-s
Dermal Contact 1.6 x 10° 1.9 x 10-s
with Soil
Ingestion of 9.4 x 10° 2. 8xl0-3
groundwater
Inhalation of NA 1. 2x10-4
groundwater
TOTAL: 1.68 x 101 3 xl 0 -3
Future Residential Fugitive Dust 8.5 x 10-3 2 .lxl0-s
(Child) Inhalation
Ingestion of Soil 5.4 x 101 2 .lxl0-s
Dermal Contact 5.8 x 100 1. 4x10-s
with Soil
Ingestion of 4.6 x 101 2.6x10-3
groundwater
Inhalation of NA 1.2xlO-4
groundwater
TOTAL: 1. 06 x 102 3xlO-3
18
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. The risk assessment indicates that the noncancer Site risks are
slightly above the EPA benchmark of 1.0 for the commercial use
sc.enario. - The HI for all exposure pathways for the on-site
worker is 1.3.
The noncarcinogenic and carcinogenic risks for the
residential use of the Site exceed EPA guidelines.
adult resident for all exposure pathways is 16.8.
child resident for all exposure pathways is 105.8.
carcinogenic risk for all exposure pathways is 3 x
adult resident and for the child resident. .
future
The HI fpr an
The HI for a
The.
1.0-3 for the
Groundwater standards, for certain contaminants, particularly
PCE, have been exceeded at the Site and downgradient of the Site.
Cadmium also exceeded its MCL in some shallow groundwater at ~he
Si~e; MCLs. are chemical specific standards that. define . ..
acceptable risk levels. Violation of such standards generally
warrant remedial action. Furthermore, since contaminated .soil
provides a source for the groundwater contamination, some.
.remedial action for soil is also warranted.
Other contaminants that exceeded groundwater standards are.
included in Table 2. PCE is the primary organic. compound. found
in Site soil. Other organic compounds, such as cis/trans 1,2-
dichloroethene, are common breakdown products of PCE. Cadmium is
the most common inorganic groundwater c9ntaminant. Other meta~s,
such as nickel or chromium, were not detected above standards as .
often as cadmium. Lead was detected above standards in a single
upgradient well. .
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 Risk
A qualitative risk assessment was .conducted to determine if
contaminants present in site soils and groundwater have impacted
or can potentially impact flora and fauna in the area. Given the
industrial nature .of the Site and the surrounding area, impacts
to. local flora and fauna are .not expected and, as a result, it
was not necessary to perform a quantitative risk assessment for
environmental risk. Furthermore, no endangered or threatened
species have been identified in the immediate vicinity of the
Site. . .
The risk assessment also considered the potential for
contaminated groundwater to reach the Miami Canal, which is about
one-half mile downgradient .of the Site. It concluded that there
was a potential for impacts to aquatic species in the canal if
contaminated groundwater reached the Canal. However, this is
unlikely given that even without remedial action, dilution,
19
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dispersion, adsorption, and biodegradation of the contaminants
may occur before the groundwater reached the Canal.
6.6
uncertainties
At all stages of the risk assessment, conservative estimates and
assumptions were made so as not to underestimate potential risk.
Nevertheless, uncertainties and limitations are inherent in the
risk assessment process.
The estimates of exposure point concentrations of the chemicals
of concern probably overstate actual concentrations to which
individuals would hypothetically be exposed and therefore, the
health risk estimates are very conservative. In addition, no
attenuation of the chemicals was considered; however, this may
reduce concentrations of organic chemicals over time.
The assumed exposure pathways evaluated in the risk assessment
are conservative in nature and may overstate the actual risk
posed by this Site. As an example, the risk assessment assumes
that an on-site worker will spend a significant amount of time
outdoors and be exposed to uncovered soil; actually, most of the
workers are indoors for a majority of their work day.
Summing risks or hazard indices for multiple contaminants ignores
the possibility of synergistic or antagonistic activities in the
metabolism of the contaminants.
7.0
DESCRIPTION OF ALTERNATIVES FOR SOIL AND GROUNDWATER
The following Site specific alternatives represent a range of
distinct actions addressing human health and environmental
concerns. The analysis presented below reflects the fundamental
components of the various alternatives considered feasible for
this Site.
Six alternatives have been identified for evaluation and are
listed below:
C-4:
Ground-water recovery and treatment; soil vapor
extraction (SVE); RCRA-type cap
Ground-water recovery and treatment; source removal and
off-site landfill disposal; RCRA-type cap
Ground-water recovery and treatment; source removal and
off-site landfill disposal; SVE; RCRA-type cap
Ground-water recovery and treatment; source in-situ
S/S; cap
Ground-water recovery and treatment; RCRA-type cap
No Action
C-l:
C-2:
C-3:
C-5 :'
C-6:
20
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7.1
Ground-Water Recovery and Treatment; SVE; RCRA-typeCap (C-
1)
This
alternative provides: .
'. Ground-water remediation
. Soil vapor extraction of
the water table with PCE
.of 90 ppm.
Capping of soil above the water table with cadmium
concentrations in excess of 73 ppm and PCE
concentrations in excess of .060 ppm but less than
90 ppm;
for organics;
organics from soil above
concentrations in excess
.
. .
. The ground water would be .removed from the subsurface by pumping
from a recovery well and would then be treated. Organic.
contaminants would be removed by air stripping. The treated
water would then either be 1) directed to Aircofor industrial
purposes and discharged to the 'P0'IW subsequent to treatment for
inorganics" or 2) treated to remove inorganics and then' .
reintroduced to the surficial aquifer through a recharge gallery.
The discharge of treated groundwater would comply with the '.
, pertinent ARARs. . '
. .
Soil vapor extraction would.be used to remove organic
contaminants from the soil above the water table or .vadose'
zone.." ,This would involve the application of a vacuum to ' .
: subsurface soils at extractio~ points and .the introduction 'of ,air
under pressure at injection points. . The subsequent movement of
air through the pore spaces of the contaminated soils would carry
volatilized VOCs with it. The captured VOCs would then be
treated, if required, or discharged directly to the atmosphere.
Soil.vapor extraction would remediate the unsaturated soil' .'
contaminated with organic constituents, including PCE in excess
of 90 ppm.
Closure of the former pond areas would be accomplished'by
installation. of a RCRA-type cap over soil with contaminant
concentrations above. the cleanup levels, except'for Gontaminated
soil that is adequately covered by' buildings, concrete, or
asphalt. The existing concrete and asphalt will be evaluated to
determine if it must be replaced by the RCRA-type cap. The cap
would substantially reduce or eliminate the leaching of Site
contaminants" particularly metals, from soil to groundwater.
Institutional controls would be implemented in order to maintain
and ensure the effectiveness' of the 'cap. Institutional controls
include: .
Additional fencing to further restrict access to the
area of concern;
Posting of appropriate warnlng signs;
A monitoring. and maintenance 'program to ~nsure that
institutional controls remain in place; and
21
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Recording of deed restrictions to control future uses
incompatible with the remedy.
Zoning restrictions for future land use already exist and deed
restrictions controlling soil excavation and the construction of
buildings would be recorded. Current fencing would be maintained
or expanded to restrict access by animals and the general public.
7.2 Ground-Water Recovery and Treatment; Source Removal and Off
Site Landfill Disposal; RCRA-type Cap (C-2)
This
.
alternative provides:
Ground-water remediation for organics and inorganics;
Excavation of sources above the water table with PCE
concentrations in excess of 90 ppm, with off-site
disposal;
Capping of all soil with PCE concentrations in excess
of .060 ppm but less than 90 ppm and cadmium
concentrations in excess of 73 ppm.
.
.
The ground water would be removed from the subsurface by purnp~ng
from a recovery well and would then be treated. Organic
contaminants would be removed by air stripping. The treated
water would then either be 1) directed to Airco for industrial
purposes and discharged to the POTW subsequent to treatment for
inorganics, or 2) treated to remove inorganics and then
reintroduced to the surficial aquifer through a recharge gallery.
The discharge of treated groundwater would comply with the
pertinent ARARs.
Soil containing PCE concentrations above 90 ppm would be
excavated and transported off-site to an approved disposal
facility. Given the elevated concentrations of contaminants
that would be present in the excavated material, the soil may
require treatment prior to disposal. Additional analysis of the
excavated material may be appropriate to confirm the need for
treatment before disposal. The excavated areas would be
subsequently backfilled with clean fill material and covered with
a RCRA-type cap.'
The purpose of this excavation would be to remove the soil
contaminated with elevated levels of PCE which is acting as a
source of underlying groundwater contamination. A small amount
of metals contaminated soil would be removed as a result of this
excavation. Existing sampling data indicate that the
contaminated soil would require disposal in a hazardous waste
landfill. If it becomes necessary to conduct further
characterization of the contaminated soil prior to disposal, the
excavated soil could possibly be stockpiled temporarily at the
Site.
Site structures and a shallow water table may render excavation
below the water table impracticable; therefore, excavation would
22
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be limited to soils above the water table and which are not
covered with substantial buildings.
Closure of the former pond areas would be accomplished by
installation of a RCRA-type cap over soil with contaminant,
concentrations above the cleanup' levels, except fQr contaminated
soil that is adequately covered by buildings, concrete, or
asphalt. The existing concrete and asphalt will be evaluated to
determine ,if it must be replaced by the RCRA-type cap. The cap
would substantially reduce or eliminate the leaching of Site
contaminants, particularly metals, from soil to groundwater.
Institutional controls would be implemented in order to maintain
and ensure the effectiveness of the cap. Institutional controls
,include:
Additional fencing to further restrict access to the
area of concern; " ,
Posting of appropriate warning signs;
A monitoring and maintenance 'program to insure that
institutional controls remain in place; and
Recording of deed restrictions to cqntrol future uses
incompatible with the remedy. '"
Zoning restrictions for future land use already exist and deed
restrictions controlling soil excavation ,and the construction of
buildings would be recorded. Current fencing would ,be maintained
or eXpanded to restrict access by animals and the general 'public.
7.3 Ground-Water Recovery and Treatment; Source Removal and Off
Site Landfill Disposal; SVE; RCRA-type Cap (C-3)
Alternative C-3 provides:
Ground-water remediation for organics and inorganics;
Excavation of sources above the water table with,
cadmium concentrations in excess of 500 ppm, with
off-site disposal; , '
Soil vapor'extraction removal of organics from soil
above t,he, water table withPCE concentrations in
excess of 90 ppm; ,
Capping of all soil with PCE concentrations in excess
of .060 ppm but less than 90 ppm and cadmium
concentrations in excess of '73 mg/kg.
The ground water would be ,removed from the subsurface by pumping
from a recovery well and would then be treat$d. Organic
'contaminants would be removed by air stripping. The treated
water would then either be 1) directed to Airco for industrial
purposes and discharged to the POTW subsequent, to treatment for
inorganics, or 2) treated to remove inorganics and then .
reintroduced to the surficial aquifer through a recharge gallery.
The discharge of treated groundwater would comply ,with the
pertinent ARARs.
23
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Soil containing cadmium greater than the cleanup levels would be
excavated and transported off-site to an approved disposal
facility. -Given the elevated concentrations of contaminants that
would be present in the excavated material, the soil may require
treatment prior to disposal. If it becomes necessary to conduct
further characterization of the contaminated soil prior to
disposal, the excavated soil could possibly be stockpiled
temporarily at the Site. The excavated areas would be
subsequently backfilled with clean fill material and covered with
a RCRA-type cap.
The purpose of this excavation would be to remove the accessible
soil contaminated with elevated levels of metals, particularly
cadmium. This excavation would reduce the volume of metals
contaminated soil at the Site. Site structures and a shallow
water table may render excavation below the water table
impracticable; therefore, excavation would be limited to soils
above the water table. Approximately 850 cubic yards of
contaminated soil would be removed. This would remove
approximately 20 percent of the unsaturated soil contaminated
with cadmium in excess of 73 ppm, and approximately 31 percent of
the unsaturated soil contaminated with PCE in excess of .060 ppm.
Soil vapor extraction would be used to remove the organic
contaminants, above cleanup levels, remaining in the vadose zone
following excavation. This would involve the application of a
vacuum to subsurface soils at extraction points and the
introduction of air under pressure at injection points. The
subsequent movement of air through the pore spaces of the
impacted soils carries volatilized VOCs with it. The captured
VOCs would then be treated, if required, or discharged directly
to the atmosphere. Soil vapor extraction would rernediate
approximately 100 percent of the unsaturated soil contaminated
with organic constituents in excess of .060 ppm at the Site, with
the exception of soil beneath buildings that cannot be completely
exposed to subsurface SVE.
Closure of the former pond areas would be accomplished by
installation of a RCRA-type cap over soil with contaminant
concentrations above the cleanup levels, except for contaminated
soil that is adequately covered by buildings, concrete, or
asphalt. The existing concrete and asphalt will be evaluated to
determine if it must be replaced by the RCRA-type cap. The cap
would substantially reduce or eliminate the leaching of Site
contaminants, particularly metals, from soil to groundwater.
Institutional controls would be implemented in order to maintain
and ensure the effectiveness of the cap. Institutional controls
include:
Additional fencing to further restrict access to the
area of concern;
Posting of appropriate warning signs;
A monitoring and maintenance program to insure that
24
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institutional controls remain in place; and
Recording of deed restrictions to control future uses
- incompatible with the remedy.
zoning restrictions for future land use already exist and deed
restrictions controlling soil excavation and the construction of
buildings would be recorded. Current fencing would be maintained
. or expanded to restrict access by animals and the general public.
7.4 Ground-Water Recovery and Treatment; Source In-Situ S/S (C-4)
This alternative provides:
. Ground-water remediation for organics and inorganics;
. Stabilization/solidification of all accessible soil.
(soil not covered by buildings) with concentrations
of cadmium in soil below the water. table that. exceed
50 ppm, and concentrations o! cadmium in soil above
the water table tnat exceed 73 ppm;. . '.
Stabilization/solidification, as described above,
will provide an impermeable barrier for soil with PCE
concentrations in excess of .060 ppm; .
Placement of a protective cover over the S/S mass.
.
..
The grourid water would be removed from the subsurface by pumping
from a recovery well and would then be treated. . Organic
. contaminants would be.removed by air stripping. The treated.
water would then either be 1) directed t'o Airco for industrial
purposes and discharged to the POTW subsequent to treatment for
inorganics, or 2) treated to remove inorganics and then
reintroduced to the surficial aquifer through a recharge gallery.
The discharge of treated groundwater would comply with the
pertinent ARARs. .
. .
In~situ S/S would be used to treat contaminated soil that is not
presently covered by Site buildings. The process utilizes'
. mechanical mixing. and injection as a means of stabilizing the
. soil 'in pia.ce. An estimated 6,700 cubic yards of contaminated
soil. would be stabilized, which includes. stabilization to a depth
of approximately 8.5 feet. . This would stabilize and solidify'
approximately 100 percent of. the unsaturated soil contaminated
with cadmium in excess of 73 ppm and. 90 percent of the .saturated
soil contaminated with cadmium in excess of 50.ppm at the Site.
Approximately 97 percent of the unsaturated soil contaminated
with PCE in excess of .060 ppm would have a reduced permeability,
as a result of S/S. .
I~-situ S/S.could treat a larger volume of metals contamin~ted .
soil than excavation because of the difficulties' associated with
excavation below the water table and the proximity to Site .
structures. However, in-situ S/S may also have some restrictions
on its area of application because of the presence of buildings
at or adjacent to the Site. .
25
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The basic components of the in-situ S/S system include a crane
with an associated mixing system. The mixing system is comprised
of an auger(s) with mixing blades and a batch mixing plant, which
supplies the necessary treatment chemicals, binding agents, and
additives. The mixing auger (typically 3 to 12 feet in diameter)
penetrates and loosens the soil, lifting it to the mixing paddles
(attached to the upper portion of the auger), effectively mixing
the additives and soil. The mixing blades move through the total
depth of the soil column in a vertical motion. Treatment
chemicals are transferred pneumatically for dry chemicals (or
pumped in cases where liquid chemicals are used) and mixed with
the untreated soil. If vapor emissions are of concern, auguring
can be performed beneath a hood which is connected to a vapor
treatment unit. Once mixing is completed to the desired depth,
the auger is retracted and begins mixing the adjacent soil,
overlapping the previously mixed zone. This process is repeated
until all of the soil is treated. After allowing the S/S mass to
cure, the concrete cap would be placed over the S/S mass to
reduce the potential of compromising its integrity.
A protective concrete cover would be installed over the S/S mass.
The surface would be graded, compacted, and sloped to direct
precipitation runoff to a desirable location. Upon completion of
grading, a reinforced concrete pad would be constructed over the
S/S mass. .
Institutional controls would also be implemented in order to
ensure the effectiveness of the cap. Institutional controls
include:
Additional fencing to further restrict access to the
area of concern;
Posting of appropriate warning signs;
A monitoring and maintenance program to insure that
institutional controls remain in place; and
Recording of deed restrictions to control future uses
incompatible with the remedy.
Zoning restrictions for future land use already exist and deed
restrictions controlling soil excavation and the construction of
buildings would be recorded. Current fencing would be maintained
or expanded to restrict access by animals and the general public.
7.5 Ground-Water Recovery and Treatmenti RCRA-type Cap;
(C-5)
This alternative provides:
. Ground-water remediation for organics and inorganicsi
. Capping of all soil with PCE concentrations in excess
of .060 ppm but less than 90 ppm and cadmium
concentrations in excess of 73 ppm.
The ground water would be removed from the subsurface by pumping
from a recovery well and would then be treated. Organic
26
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contaminants would be removed by air stripping. The treated
water would then either be 1) directed to Airco for industrial
purposes and discharged to the POTW subsequent to treatment for
inorganics, or 2) treated to remove inorganics and then.
reint~oducedto the su+ficial aquifer. through a recharge gallery.
The discharge of treated groundwater would comply with the
pertinent ARARs. .
Closure of the former pond areas would be accomplished by
installation of a RCRA-type cap over soil with contaminant
concentrations above the cleanup levels, except for contaminated
soil that is adequately covered by buildings, concrete, or
asphalt. The existing concrete and asphalt will be evaluated to
determine if it .must be replaced by the RCRA~type cap. The.cap
would substantially reduce or eliminate the leaching of Site
contaminants~ particularly metals, from so~l to gioundwater~
Institutional controls would be implemented in. order to maintain
the effectiveness of the cap. Institutional controls include:
Additional fencing to further restrict access to the
area of concerni
Posting of appropriate warning signsi
A monitoring and maintenance program to insure that
institutional controls remain in placeiand .
Recordi.ngof deed restrictions to control :future uses
. incompatible with the remedy. ..
Zoning restrictions for future land use already exist and deed
restrictions controlling soil excavation and the construction of
buildings would be recorded. Current fencing would be main~ained .
or expanded to restrict access by animals and the general .
public. . .
7.6 No Action (C-6)
No remedial action would occur under this al~ernative.
7.7. Volume of contaminated m~dia:
The amounts of contaminated soil, based on EPA-derived soil
cleanup levels, are estimated as follows:
..
Volume of soil above the water table contaminated with
inorganics:. approximately 4,225 cubic yards (soil with
cadmium concentrations in excess of 73 ppm) .
Volume of soil below the water table contaminated with
inorganics: approximately 2,500 cubic yards (soil with
cadmium concentrations in excess of 50 ppm)
.
27
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.
Volume of soil above the water table contaminated with
organics: approximately 140 cubic yards (soil with PCE
concentrations in excess of 90 ppm)i approximately 1,960
cubic yards (soil with PCE concentrations in excess of .060
ppm)
Volume of contaminated groundwater: approximately 3,411,000
gallons.
8.0 COMPARATIVE ANALYSIS OF ALTERNATIVES
The alternatives are evaluated against one another by using the
following nine criteria:
.Overall protection of human health and the
.Compliance with Applicable or Relevant and
Requirements (ARARs).
.Long term effectiveness and permanence.
.Reduction of toxicity, mobility, or volume
.Short term effectiveness.
.rmplementability.
.Costs.
.State Acceptance.
.Community Acceptance.
environment.
Appropriate
through treatment.
The NCP categorized the n1ne criteria into three groups:
(1) Threshold criteria: the first two criteria, overall
protection of human health and the environment and compliance
with ARARs (or invoking a waiver), are the minimum criteria
that must be met in order for an alternative to be eligible
for selection
(2) Primary balancing criteria: the next five criteria are
considered primary balancing criteria and are used to weigh
major trade-offs among alternative cleanup methods
(3) Modifying criteria: state and community acceptance are
modifying criteria that are formally taken into account
public comment is received on the proposed plan. State
community acceptance is addressed in the responsiveness
summary 0 f the ROD.
after
and
The comparative analysis of the six alternatives proposed for
this Site are presented in the following section.
8.1 Comparative Analysis of Combined Remedial Alternatives
1.
Overall Protection of Human Health and the Environment
28
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II
Except for the nQ'action alternative, all the alternatives
would provide protection for human health and the
environment. These alternatives all treat the contaminated
ground water and provide protection from contact with
contaminated soil as well as reduced leachate potential
through either excavation and/or treatment as well as Site
capping. .
2.
Compliance with ARARs
The no action alternative would not comply 'with ARARs because
contaminants would remain in ~xcess of soil and groundwater
action levels.'
All of the combined alternatives include ground water
. treatment, and this component of the remedy would comply with
.ARARs (see Tables 4 and 5). Alternatives C-l, C-2, and C-3
will reduce the ongoing source of PCE contamination in .
. groundwater and thus'reduce the time necessary to achieve
ARARs for organic 90ntaminants. Alternatiye C-5 will likely
take longer to achieve ARARs for organic compounds in
groundwater.because a cap alone will not red~ce the leaching
of PCE from soil for PCE concentrations greater than 90 ppm.
Groundwater remediation time frames maybe extended if metals
leach to the ground water. Alternative C-4 maybe more
ef.fecti ve at reducing remediati.on time frames for .metals in
groundwater. Alternative C-3 provides a lesser amount of
saturated soil metals removal.
3. . .Lonq-Term Effectiveness and Permanence
All the alternatives., except no action, would reduce
potential risks and environmental impacts. Alternative. C-3
would provide the highestqegree of long term effe9tiveness .
and permanence because it includes excavation and offsite
disposal and SVE. for certain .sources of c.ontaminated .soil .in
. addition to treatment of the ground water. Exposure to .
contaminants would be essentialiy eliminated.
Alternative C-l would provide a high degree of long term
effectiveness and permanence because the RCRA-type cap would
reduce infiltration and, in combination with deed
restrictions and institutional controls, would restrict
access to contaminated soil. Organic contaminants in the
vadose zone wQuldbe removed. Ground water recovery and
treatment would provide remediation of Site ground water and
would'reduce risks associated with human or environmental
exposure to ground water~ Alternative C-2 would provide an
approximately equal level of long~term effectiveness and'
permanence. .
29
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TABLE 4
POTENTIAL LOCATION SPECIFIC ARARs
I
Citation Location/Description
A . Florida Administrative Code 17-524 and Florida Statute 373.309 Areas of known contamination. Regulatory clearance required to
use potable water wells in area of known contamination.
A 'Florida Administrative Code 17-736 Hazardous waste sites. Requires use of warning signs to inform
public of potentially harmful conditions at sites.
A 'Endangered Species Act of 1973 (50 CFR Part 200 and Part 402) Critical habitat upon which endangered or threatened species
'Fish and Wildlife coordination Act (33 CFR Parts 320-330) depends
R&A -General RCRA Facility Location Standard (40 CFR 264 .18(b]) Within 100-year floodplain
-TSCA requirements (40 CFR 761. 75)
.Protection of floodplain (40 CFR 6, Appendix A)
'Fish and Wildlife coordination Act (40 CFR 6.302)
.TSCA 140 CFR 761.75)
R&A 'Florida Administrative Code 17-55.312 Location of public drinking water wells. Buffer zone of no less
than 500 feet between future potable well and existing land
applications of reclaimed water areas
A = APPLICABLE REQUIREMENTS WHICH WERE PROMULGATED UNDER FEDERAL LAW TO SPECIFICALLY ADDRESS A HAZARDOUS SUBSTANCE, POLLUTANT, CONTAMINANT,
REMEDIAL ACTION LOCATION OR OTHER CIRCUMSTANCE AT THE SITE.
R . A = RELEVANT AND APPROPRIATE REQUIREMENTS WHICH WHILE THEY ARE NOT 'APPLICABLE' TO A HAZARDOUS SUBSTANCE, POLLUTANT, CONTAMINANT, REMEDIAL
ACTION, LOCATION, OR OTHER CIRCUMSTANCE AT THE SITE, ADDRESS PROBLEMS OR SITUATIONS SUFFICIENTLY SIMILAR TO THOSE ENCOUNTERED AT THE SITE THAT
THEIR USE IS WELL SUITED TO THE SITE.
30
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'1'ABLE 5
PO'1'ENTIAL CHEMICAL-SPECIFIC AND AC'1'ION-SPECIFIC ARARs
-
~ WATKR ACT - 33 O. S. C. 1251-137&
40 CFR Part 122-125: National Pollutant Requires permits for 'the discharge of pollutants for
Discharge Elimination System any point source into waters of the United States.
R &. A 40 CFR 131
40 CFR 136.1
R &. A 40 CFR Part 131 - Ambient Water Quality Suggested ambient standards for the protection of
Criteria requirements human health and aquatic life.
R &. A 40 CFR Part 146 Technical criteria and standards for the UIC program.
Class IV and V well criteria and standards
A CWA 402 (a) (1) Effluent limitations are required to achieve all
appropriate state water quality standards
A 40 CFR Part 403 - National Pretreatment Sets standards to control pollutan~s which pass,
Standard,s through or interfere with treatment processes in"
public treatment works or which may contaminate
sewage sludge.
~BO'DRa CONSKRVATION ANtI RBCOVKRY',ACT - '42 O.B.C. '1901-&1187
A, 40 CFR Part 241 - Guidelines for the Land Establishes minimum levels of performance required of
R&.A, Disposal of Splid Wastes any solid waste land disposal Site operation and
includes operation and maintenance.
R&.A 40 CFR Part 261 - Identification and Defines those solid wastes which are subject to
Listing of Hazardous Wastes regulation as hazardous wastes under 40 CFR Parts
263-265 and Parts 124, 270, and 271.
R &. A 40 CFR Part 262 - Standards Applicable to Establishes standards for generators of hazardous
~enerators of Hazardous Waste wastes.
40 CFR Part 263 - Standards Applicable to Establishes standards which apply to transporters of
'A 1'ransportat'ion of ,Hazardous Waste hazardous ,waste within the U.S. if the transportation
requires' a manifest under 40 CFR Part 262.
40 CFR Part 264 - Standards for Owners and Establishes minimum national standards which define
R &. A ~perators of Hazardous Waste Treatment, the acceptable management of hazardous wastes for
Storage and Disposal (TSD) Facilities owners and operators of facilities which treat, store
or dispose of hazardous wastes.
40 CFR Part 268 - Land Disposal Identifies hazardous wastes that are restricted from
A1.a 51 FR 40641 land disposal and describes those circumstances 'under
52 FR 25760 which an otherwise prohibited waste may be land
RCRA sections 3004(d) (3), &. (el (3) disposed.
BAn DllDIItDIQ WATER ACT - 40 O'se section 300
A 40 CFR Part 141 - National Primary ',Drinking Establishes maximum contaminant levels, (MCLs) which
"ater Standards are health-based standards for public water systems.
R &. A PL No. 99-339 100 Stat.462 (1986) - Maximum Establishes drinking water quality' goals set at
Contaminant Level Goals (MCLGs) levels of no known or anticipated adverse health
effects with an adequate margin of safety;
~ An AC'1'
'A 40 CFR Part 52 Part 50 specifies the maximum primary and secondary
24-hour concentrations for listed pollutants.
Subchapter C, Part 52, provides federal appr~val of
Florida's air quality implementation plan, with
standards. criteria, and procedures.
A 40 CFR Part 61 - National Emission Addresses hazardous air pollutants at their point of
Standards for Hazardous Air Pollutants emission from specific sources
DTKRIALS TRANSPORTATION ACT - U O'.S. C 1801-1813
40 CFR Parts 107, 171-179: Hazardous Regulates transportation of hazardous
A Materials Transpor~ation Regulations ~aterials.
ISTATa ARARS I I
FAC 17-730 Florida hazardous waste management regulations
R &. A FAC 17-302.300 Antidegradation policy for surface water quality.
Prohibits discharge of wastes into Florida waters
~ithout treatment to protect beneficial uses.
31
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I TABLE 5 (cont.) I
R I< A FAC 17-710 Used oil management regulations.
A FAC 17 -28 Regulations to control discharges to groundwater.
Authorizes zone of discharge for facilities
discharging to ground water as July L 1982.
R I< A FAC 17-2.3 Specifies ambient air quality standards not to be
exceeded for listed pollutants
A FAC 17-2.1 Regulations to el iminate, prevent, and control air
pollution
A FAC 17-4 Establishes procedures and requirements to obtain a
penn i t from FDEP
R I< A FAC 17-6~" Effluent di scharge requirements for industrial
wastewater treatment facilities.
A . AI'9UCAILI UQUI'.u.KDrrn'lMoGOI WUI ~ UJrC>U TlDUAL. LAW fO lPIa1fCAU.y ADCU'" ..."AZMtDOUI 1tlUrAM1 JItOU.JJrMlf. c::cM'AII8NAM', alfEaAL JfCJ'JOIlDCADOIHOI: 01NU CDQJIUTAN::8 Jtr D8 8ft.
R 1:1 A . UU'lANr I/H} ~ UQUIUMDo'T'I ~ IHU 1HIY AU M'J'I' "MIIUCAIU" 1'0 A HAZAotDOUf 1UN1'AfrQ. I'CIILID'AHT. CXlh'fAllNMrtr. UIGLIAL 1ftCfJOI. LOCmON. 0« ODIU CJIa£IU1'MCI A.'r!HI am. ADDIUI
""IO&IMI 01 8'TUA2J(».8 AlntO'IMI.r IUII1M: 'f"O!JfOM ~D A:I 'DR In'lINAr 1H81.111 J' .u. RlTID TO DR &JTI.
1.CHDIICAt.SPIC1IC-
- AC'DON-ftCFIC UQUIWIIIHr
32
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Alternative C-4 provides approximately the same level of
long-term effectiveness and permanence as C-l. The treatment
process would immobilize metals, and the permeability of the
mass relative to organics would be reduced, but the toxicity
and volume of contaminants would not be reduced. Access
restrictions would be required to continue effect{veness, and
this is provided by the capping alternatives. . The only
penefit provided by alternative C-4 over the other
alternatives is that the ground water remediation time frame
for. metals may be reduced. .
Alternative C-5 would provide effectiveness and permanence,
but not to the extent of the other alternatives in .
consideration since contaminants in Site soils would not be
removed 'or immobilized. AiternativeC-6 would provide little
or no long-term effectiveness or permanence. .
4.
Reduction of Toxicity, Mobility, or Volume
All combined alternatives include ground water remediation,
~o the only relative differences between the alternatives are
restricted to the components of the alternatives that address
soil contamination. The ground water remediation system
would remove ground water contaminants, and thus would reduce
toxicity, mobility, and volume. .
Alternative C-3 would provide' the greate~t reduction of.
toxicity, mobility, .and volume of all. the alternatives'
through removal and treatment of limited sources of
contaminants in the soil. Soil vapor extraction would
effectively reduce the toxicity, mobility, and volume of any
VOCs remaining following excavation. Most of the organic.
contaminants in unsaturated soil would be removed, and about
20 percent of the inorganics in unsaturated soil would b~
removed, and about 25 percent of the saturated soil
inorganics'would be removed. The cap would essentially.
eliminate infiltration tPrough remaining contaminated soil. .
. .
AlternativesC-l and C-2 would provide a relatively 'moderate
degree of reduction in toxicity, mobility, and volume. Both
alternatives would remove unsaturated soil organic'
contaminants to the 90 ppm level. Alternative C-2 would
remove a small percentage of unsaturated soil inorganics,
while neither alternative would remove saturated soil
inorganics. .
Alternative C~4 would provide a lesser degree of reduction of
toxicity, mobility, and volume, si.nce soil contaminants would
not be removed; they would be bound in place thereby reducing
their mobility. .
Alternative C-5 would provide an even lower degree of
reduction in toxicity, mobility, and volume, because sipce it
does not provide for treatment of soil contaminants.
Alternative C~6, no action,' would rank lowest for this
criteria.
33
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5.
Short-Term Effectiveness
All the alternatives present some potential risks to
remediation workers, local workers, and the environment
during implementation. Alternatives C-1 and C-5 could be
implemented more quickly than the other alternatives, and
require the least amount of soil disturbance and intrusion.
Any volatile emissions or fugitive dust generated could be
controlled through the application of water (wetting) or foam
vapor suppressants.
Alternatives C-2, C-3, and C-4 present additional risks to
remediation workers and local.workers during implementation
due to heavy equipment operation within Site constraints. .
These risks would be controlled by the implementation of
appropriate health and safety procedures during construction.
6.
Implementabilitv
All the alternatives, except for no-action, may require that
a treatability study or pilot test be performed.
Alternatives C-1 and C-5 would not require any specialized
equipment to implement.
Alternatives C-2 and C-3 would be more difficult to implement
because of Site access and space limitations. Both of these
alternatives include excavation, which can be conducted at
the Site but may require consent by adjacent property owners
and will require more planning than at typical Sites.
Site structures limit access to the majority of the
contaminated soil. To completely remove contaminated soil,
he treatment building and a portion of the main building may
eventually have to be demolished. Excavation to recover all
contaminated soil to 16 feet is not possible with the
buildings on Site, and with adjacent buildings. Excavation
to a depth of 16 feet would include "wet" excavation because
the water table occurs at about 6 feet. The sandy soil would
sluff under the wet conditions and, even with shoring,
building stability would be in jeopardy. Because of
implementability problems, contaminated soil source removal
to a depth of 8 feet is the only excavation considered
implementable.
AlternativeC-4 would require specialized technical expertise
as well as specialized equipment, and requires a large amount
of space for the equipment. S/S equipment is large and would
be difficult to maneuver in the limited space at the Site.
The in-situ S/S mixing equipment may not be able to reach
soil beneath Site or adjacent buildings, and would require a
minimum setback of one to two feet from the buildings. The
space limitations would require staging because equipment
would have to be setup over stabilized material to access
unstabilized material. On-site and some off-site business
34
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activities may have to be suspended during S/S
implementation. This remedy may also interfere with adjacent
businesses because equipment would have to mobilize over and
setup some operations on adjacent property. This alternative.
would be the most difficult to implement.
£Qg
7 .
The cost estimates for the various alternatives are
.sumrnarized in order of least to highest present worth below.
1IIIIIIIIIIilllllll~llllllllljillllllill[lllijllllllll111111111111111111111111111111111111111111111111111111Ijlllllllii~11
$0 $0 $0 .
C-6 - No Action
C~5 - GW Recovery &
Treatment; .
R<:RA-type cap
C-2 - GW Recovery &.
Trea tmen t ; .
limited source removal;
RCRA-type' cap'
$399,750
$71,900
$1,505,000
$442,200,
$71,900
$1,547,400
C-1 - GW Recovery &
Treatment;
RCRA-type cap; SVE
C-3 - GW.Recovery &
Treatment;
limited source removal;
SVE; RCRA-type cap
$445,500
$9.2,600
$1,868,900
$800,813
$92,600
$2,224,200.
C-4 - GW Recovery &
Treatment; limited source
in-situ S/S; .concrete cap
$1,-801,500
$75,000
$2,954,400
. 8.
community Acceptance
. . . ." . . '" .
The local community did not have any significant comment on
the various remedial alternatives. One commentor did not.
disapprove of .the selected remedy, but did raise various'
questions regarding the risk assessment process and the
. general Superfund process. Responses to their questions are
provided in Appendix B. - Responsiveness Summary.
An equipment vendor submitted a limited proposal for
groundwater treatment which'was s~milar to one of the
.tr:eatment methods described in the FS. Based on the.
available information, EPA concluded that the vendor's
.proposed method would not be cost effective.
9.
State Acceptance
The State of Florida accepted portions of the selected remedy
35
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including the gro~ndwater treatment and deed restrictions,
but recommended excavation or solidification of the
contaminated soil in ,order to control the leaching of metals
to groundwater. EPA does not agree with the State regarding
excavation or solidification of soil since those methods
would likely be the most difficult to implement because of
the space constraints at the Site. In addition, excavation
of all metals contaminated soil would require the demolition
of some Site buildings, including the existing industrial
wastewater pretreatment plant.
The metals contamination in groundwater is generally limited
to the shallow groundwater and has not migrated beyond Airco
Plating's property. Furthermore, the selected groundwater
action is expected to capture the groundwater contaminated
with metals and will include treatment for metals in
extracted groundwater if necessary to satisfy discharge
requirements.
Groundwater monitoring is a component of the selected remedy.
If long term monitoring indicates that the cap is not
effective in reducing metals concentrations in groundwater,
then it may be necessary to conduct more active soil
remediation measures.
8.2
Synopsis of Comparative Analysis of Alternatives
All the alternatives, except for No-Action, would provide
some. degree of overall protection of human health and the
environment and would comply with ARARs. Each of the
remaining five alternatives included groundwater extraction
and treatment to address VOCs in groundwater. Therefore, to
select from among the remaining five alternatives, more
significance was given to reducing the volume of PCE in soil
through treatment because PCE is the most mobile contaminant
at the Site when compared to the metal contaminants.
Therefore, active measures such. as soil vapor extraction were
favored. Excavation and off-site disposal of the PCE
contaminated soil would be effective but there is a
regulatory preference for treatment and a regulatory bias
against the off-site disposal of untreated wastes. The soil
vapor extraction will result in a permanent reduction of
organic contaminant concentrations in the Site soil.
Capping the metals contaminated soil was considered
sufficient to reduce the leaching of metals from soil to
groundwater. More active measures such as excavation to the
water table ~nd in-situ S/S would also be effective but would
have been more difficult to implement because of space
constraints at the Site and the presence of functional
buildings at and adjacent to the Site. In addition,
alternative C-4, which included in-situ S/S, had costs which
were double the costs of alternativeC-5, which included a
cap.
36
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9.0 SELECTED REMEDY
Based upon consideration of the requirements of CERCLA, the
NCP, the detailed analysis of alternatives and public and
state comments, EPA has selected a combined source control
and groundwater remedy for this site.' At the completion of
this remedy, the risk associated with this Site has been
determined to be in the range from 1x10-s to 1x10-6 which is
considered to be protective of human health and the
environment.
The total present worth cost of the selected remedy,
Alternative C-1, is estimated at $ 1,868,900. Th~s includes.
capital costs of $445,500 and annual O&M costs of $92,6'00.
A.
Source Control
Source control remediation will address the contaminated
soils at the Site. The primary contaminants are metals,
including cadmium, and'VOCs including PCE. Source control
will include soil vapor extraction of VOCs fromso{labove
the water table, capping metals and VOC contaminated soils,
and institutional controls (including deed restrictions),
tnat will preserve the integrity of the cap and prohibit
activities that are not compatible with the seleGted remedy.
A.1 Major' components of source control include:
a.
Soil vapor extraction of VOCs, including PCE
concentrations greater than 90' ppm, for Site soil to
a depth of 5-6 feet below land surface, or just above
the water table, whichever is lower.
b.
A RCRA-type cap over soil above t.he water table with"
cadmium concentrations in .excess of 73 ppm and PC:S
concentrations in excess of .060ppmbut less than 90.
ppm; . .
c.
. .
Institutional controls, including deed restrictions
that are not inconsistent with the NCP, that shall:
1) preserve integrity of the cap and restrict
activities that are. not compatible with the remedy.
The restrictions would prohibit residential use of
the Site as long as the contaminated soil remains in
place and would prohibit removal of the cap unless
any necessary remedial action, such as soil .
treatment, was conducted; 2) ensure that the remedy
.remains protective of human health and the.
environment. if on-site buildings that are currently
located over contaminated.soil undergo any.
significant physical modification or alteration.
Those areas under such buildings would then be
evaluated to determine if remedial action is
necessary, such as extending a RCRA-type cap over
37
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those areas.
d.
A pilot-scale treatability study of the soil vapor
extraction system will be necessary during the
remedial design in order to maximize the performance
of the system. In addition, modeling of projected
air emissions and analysis of actual air emissions
from the pilot plant will be conducte~ in order to
determine the need for air emission control equipment
for the system.
e.
Review of the periodic groundwater monitoring results
to determine the effectiveness of the cap at reducing
the concentrations of inorganics in groundwater at
the Site. If metals concentrations in Site
groundwater increase or do not decrease within five
years after installation of the cap, then the need
for active soil treatment measures such as
excavation, solidification, etc., shall be' evaluated.
f.
Compliance with ARARs listed in Tables 4 and 5 and in
this Section 9.
A.2 Treatment of in-situ material
Site
with
than
with
Soil action levels are intended to reduce the leaching of
contaminants from soil to groundwater so that groundwater
standards are no longer exceeded, or to reduce the risk
associated with exposure to contaminated soil. The
levels for PCE and cadmium were calculated by using the
Summers model, which is more fully explained in Appendix
C of the FS.
Soil action levels were set for PCE because it is the
primary organic contaminant detected at elevated
concentrations in Site soils. PCE found in Site soil is
the likely source of PCE and related organic compounds
found in Site groundwater. Soil action levels were set
for cadmium because it is found at elevated levels in
soil and is acting as a source of cadmium in underlying
groundwater.
Site soil containing elevated levels of cadmium generally
contain elevated levels of other metals and cyanide.
Therefore, action for cadmium contaminated soil will also
address other metals and cyanide found in the soil.
Nevertheless, action levels for the other site
contaminants have also been developed. They are
generally based on calculated allowable levels for
exposure to soil.
soils above the water table that are contaminated
PCE concentrations greater than .060 ppm and less
90 ppm will be capped as well as soil contaminated
cadmium concentrations greater than 73 ppm.
38
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.-."..- - . ...
However, since PCE is a highly mobile contaminant, the
cap is not exp~cted to reduce the potential for leaching
of PCE in soil for PCE concentrations greater 90 ppm.
Thgrefore, Site soils above the water table that are
contaminated with PCE at concentrations greater than 90
'ppm will be treated by soil vapor extraction. This, '
method involves the application of a vacuum to subsurface
soils at extraction points (typically wells) and the'
introduction of air under pressure at injection points.
Th~ resulting movement of air through the pore spaces of
the contaminated soils carries volatilized VOCs with it.'
The captured VOCs will then be treated, if necessary, or
discharged directly to the atmosphere. At a minimum,
additional air emission testing coupled with a risk
assessment methodology will be conducted to evaluate the
need for'air emission control equipment for the soil'
vapor extraction. system alone and in 'combinat'ion with the
air stripping tower used for groundwater treatment:
'A.3 Performance Standards
Because certain performance standards may not be
determined until the Remedial Design Phase, and beoause
certain minor performance standards may not be listed,
the list of Performance Standards in this section is not
exclusive. The performance standards for this component
of the selected remedy include, -but are not limit,ed 'to~ "
the following standards: ',' ",
a.
Treatment standards
PCE concentrations in Site soils
feet below land surface, or just
table, whichever is lower, shall
than or equal to 90 ppm by SVE.
b.Capping,standards
to a depth of .5-6
above the water
be reduced to less
" ,
Site soils above the water' table that are
contaminated above the action ,levels listed below
wi 11 be capped.
CON'rAMINANT SOIL ACTION LEVEL (ppm)
Tetrachloroethylene (PCE) >.060 and <901
Cadmium 731
Chromium 1,3502-~
Copper 9, 990r}
Cyanide 5,940r3
Lead 50~3
39
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Nickel 5,4003
Zinc 8,1003
1 Summers model calculation - protection of groundwater
2 Florida Background Level
3 BRA - protection of human health from contact with soil
In general, the cap shall comply with the pertinent
portions of 40 CFR 264 Subparts, F, G, and K. In
particular, the cap will substantially eliminate
infiltration and thus reduce leachate generation of
metals and organic compounds in general, and cadmium and
PCE in particular. The soil cleanup levels are based
upon a cap permeability value of 10-7 ern/sec. At a
minimum, the cap will be designed so that it meets the
requirements in the EPA guidance document "Construction
Quality Management for Remedial Action and Remedial
Design - Waste Containment Systems" (EPA/540/R-92/073)
and other relevant guidance. The cap will be a
"hardened" cap as required for the closure of hazardous
waste storage facilities where it is advantageous to
continue using the Site.
As part of the construction of the cap, the surface would
be graded, compacted, and sloped to direct precipitation
runoff to a desirable location. Upon completion of
grading, a geosynthetic layer would be placed on the soil
surface. Next, a geomembrane would be put in place which
would then be topped by a granular drainage layer.
Finally, a reinforced concrete pad would be constructed
to protect the underlying layers and to provide a durable
working surface for ongoing industrial activity.
In addition, the cap will satisfy the pertinent
requirements in 40 CFR 264.90 -.120/ and 264.228 which
include:
-provide long term minimization of liquids through the
closed surface impoundment.
-function with minimum maintenance
-promote drainage and minimize erosion or abrasion of the
final cover
-accommodate settling and subsidence so that the cover's
integrity is maintained
-maintain the integrity and effectiveness of the final
covert including making repairs to the cap as necessary
-have a permeability less than or equal to the
permeability of any bottom liner system or natural
40
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subsoils present
Use of the capped area for commercial purposes will
follow the substantive requirements found. in 40 CFR
264.~17 -.120 regarding post closure care and use of
property including, but not limited to, maintenance,
groundwater monitoring, post closure plans and notices,
etc.
The estimated size of the cap is approximately 12,500
square feet. The size of the cap may increase if .
existing concrete or asphalt at the Site does not provide
an equivalent level of protection or effectiveness. A
final decision regarding the effectiveness of the
existing covers will. be made during the RD.
c.
D~scharge standards
Air emission ~odeling and monitoring coupled with a risk
assessment methodology will be conducted to evaluate the
need for air emission control equipment for the soil.
vapor .extraction system alone and in combination with the
air stripping tower. .
Air emissions from the SVE system shall comply with EPA
Office of Solid Waste and Emergency Response Directive
93~5.0-28 titled Control of Air Emissions from Superfund
. Air Strippers from Superfund Groundwater Sites. This
guidance indicates that air emission sources need.
controls if their actual emission rates for total VOCs
exceed:
3 pounds/hour or
15 pounds/day or
10 tons/year
Air emissions shall also comply with levels included
and/or referred to in the guidance document entitled
i;Estimatiol1of Air Impacts for Air Stripping of . ... . .
Contaminated WaterU (EPA-450/1-91-002, dated 5/91),. where
appropriate.
Air emissions must also comply with State regulations
identified as ARARs for this Site. Florida regulations
in Chapter 17-2 provides requirements for sources ~hich
emit pollutants. If any contaminant regulated by these
standards will be released by the planned remedial
action, the regulations shall be followed.. .
Air emissions that exceed the standards ref.erred to above
shall. be collected and treated by carbon absorption,
vapor membrane separation, or other suitable methods as
approved by. EPA.
41
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B.
Groundwater Remediation
Contaminated groundwater will be removed by pumping from
recove~ wells designed to provide effective capture of
dissolved contaminants. The extracted ground water will then
be treated by air stripping. The treated water will then
either be directed to Airco (for industrial purposes and
discharged to the POTW after meeting POTW permit requirements
for inorganics), or, as necessary, treated to remove
inorganics and then reintroduced to the surficial aquifer
through a recharge gallery on-Site.
B.1.
The malor components of qroundwater remediation to be
implemented include:
Extraction of contaminated groundwater and treatment by air
stripping at the Site; and
a. Discharge of treated water to the POTW or to the
surficial aquifer via a recharge gallery on-Site in
accordance with all applicable regulations and other
Performance Standards.
b. Evaluation of the need for treatment of inorganics in
groundwater will be conducted during the RD.
c. Air emissions will be sampled during the initial
operation of the air stripping tower. The purpose of the
sampling will be to validate the air emissions mOdeling
included in the FS. Air emission control equipment will
be added to the design of the air stripping system if EPA
determines that such equipment is necessary.
d.
Compliance with ARARs listed in Tables 4 and 5 and
this Section 9.
B.2.
Extraction, Treatment, and Discharqe of Contaminated
Ground Water
Groundwater beneath and downgradient from the Site contains
VOCs at various depths in the Biscayne Aquifer. Some metals,
including cadmium, have also been detected primarily in
shallow groundwater at the Site.
The contaminated groundwater will extracted by extraction
wells. The groundwater extraction well design and
installation requirements will be finalized during the design
phase. However, according to the FS, one extraction well
pumping at a rate of approximately 75 gprn would be sufficient
to contain the entire contaminant plume within 180 days.
The VOC contaminated groundwater will be treated by air
stripping to remove the VOCs. Air stripping equipment is
generally classified as either packed towers or low profile.
42
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The specific tyPe of air stripping system will be determined
during the RD and will depend upon flow rates, influent
concentrations, efficiency rates, etc. In either type of
system, air is forced through the groundwater in order to
,volatrlize the VOCs. According to the FS, a single packed
tower', about 30 feet high would be required to achieve
cleanup levels for groundwater.
The need for treatment of inorganics in groundwater will b~
determined during the RD/RA. This will be accomplished
during a pilot scale operation of the airstripping tower.
Treated effluent from the tower will be analyzed for
inorganics. If contaminants are detected above discharge
standards, then appropriate treatment methods shall be
designed. If inorganic contaminants are detected
consistently during periodic effluent sampling from the full
scale operat:lon of the groundwater treatment system, then an
EPA approved' design for inorganics treatment shall' be ",
implemented. '
Treated groundwater will be discharged to either the POTW, an
on-site recharge gallery, or a combination of both. '
Currently, Airco Plating'only discharges a portion of the
total daily volume allowed under its permit with DERM (Dade
Couhty) for discharge to the POTW. This excess discharge
capacity may be utilized for disposal of a portion of the
treated groundwater, if authorized by DERM and the POTW. The
remainder 'of the treated groundwater could then be discharged
to an on-site recharge gallery that would discharge the'
treated water to th~ surficial aquifer. However, a recharge
gallery shall be designed in such a manner so as to allow for
the discharge of all treated water if conditions prohibit a
discharge to the POTW. It shall also be designed so that
urechargedu water does not adversely alter the migration
pattern. '
, Air emissl.onsfrom' a packed column air stripping tower have
been estimated. Based on the estimates developed in the FS,
air emissions shouidno~' exceed allowable levels. ' However,
since the soil vapor extraction'system for soil will also
have air emissions that were not estimated, additional air,
emission testing coupled with a risk assessment methodology
will be conducted to evaluate the need for air emission
control equipment for the air stripping tower, the soil vapor
extraction system, or both. "
All sampling conducted during the RD/RA is subject to
verification by EPA.
B.3.
Performance Standards
Because'certain performance standards may not be determined
until the Remedial Design Phase, and because certain minor
performance standards-may not be listed, the list of
Performance Standards in this section is not exclusive.'
4'3
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a. Extraction Standards
Groundwater at the Site which exceeds federal and/or
state groundwater standards, particularly those
listed in the following table, will be extracted. A
pumping rate of 75 gallons per minute was used in the
FS as estimates of the pumping rate necessary to
contain the entire plume; these values will be
further evaluated during the RD.
b. Treatment Standards
Groundwater shall be treated until federal and/or
state groundwater standards are attained at the wells
designated by EPA as compliance points. These
compliance points are currently considered to be
located at the immediate boundaries of the capped
area, the furthest extent of the contaminant plume,
and the extraction wells.
The groundwater treatment standards include the
levels listed in the following table - "Groundwater
Extraction and Treatment Standards".
Some of the groundwater treatment standards include
promulgated State groundwater standards that are more
stringent than Federal standards. These State
standards are ARARs that shall be complied with and
include:
Trichloroethylene 3 ppb
Tetrachloroethylene 3 ppb
Vinyl Chloride 1 ppb
Acetone and bis(2-ethylhexyl)phthalate, listed as
contaminants of concern in the Risk Assessment, might
not be Site related. It is possible that these
compounds are laboratory compounds that contaminated
a groundwater sample during the RI but are not
actually present in Site groundwater. Additional
sampling and analysis of groundwater will be
conducted during the RD to confirm the presence or
absence of these compounds.
CONTAMINANT
Acetone
Chloroform
Cis/trans 1,2 dichloroethylene
1, 1-Dichloroethylene
GROUNDWATER EXTRACTION AND
TREATMENT STANDARDS (ppm)
NA
.1001
.07/.1001
.0071
44
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Tetrachloroethylene (PCE)
Tr i chloroethene
Vinyl Chloride
Bis (2-ethylhexyl)phthalate
Cyanide
Cadmium
Chromium
Copper
Lead
Nickel
Zinc
.0032
.0032
.0012
NA
.2001
.0051
.1001.
1.33
.0154
.1001
5 . o5 :
1 Federal MCL 2Florida Groundwater standard 3 Federal MCLG
4 Federal action level 5 Federal SMCL
c. Discharge Standards
Discharges from the ground water treatment system
shall comply with all ARARs, including, but not
limited to, federal and -state groundwater standards
and all effluent limits established by EPA.
Treated water discharged to the recharge gallery
shall meet performance standards including those
noted in 9.B.3.b.
Treated water discharged to the POTW shall meet the
standards required by the POTW and/or .DERM. DERM has
issued an annual waste pretreatment operating permit
to Airco Plating. The current standards for
pretreatment of wastewater prior to discharge to the .
POTW include:
Parameter
Flow, total
PH
Cadmium
Chromium
Chromium, hex
Copper
Daily Maximum Limit
80,000 gal Ions /day
9.5
(5.5 is monthly average limit)
.5 mg/1 .
1.0 mg/1
.5 mg/1
.5 mg/1
45
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Cyanide
Lead
Nickel
Silver
Zinc
Total Toxic
Organics (TTO)
Total Metals
(Cu, Cr, Ni, Zn)
.1 mg/1
.3 mg/1
1.5 mg/1
.4 mg/1
1.0 mg/1
2.0 mg/1
2.0 mg/1
Airco Plating is currently discharging approximately
45,000 gallons/day of treated wastewater, thus there
is currently unused capacity in the total permitted
daily discharge at the Site. Use of this discharge
option is dependent upon the approval of DERM and the
POTW.
Air emissions from the groundwater treatment system
shall comply with EPA Office of Solid Waste and
Emergency Response Directive 9355.0-28 titled Control
of Air Emissions from Superfund Air Strippers from
Superfund Groundwater Sites. This guidance indicates
that air emission sources need controls if their
actual emission rates for total VOCs exceed:
3 pounds/hour or
15 pounds/day or
10 tons/year
Air emissions shall also comply with levels included
and/or referred to in the guidance document entitled
"Estimation of Air Impacts for Air Stripping of
Contaminated Water" (EPA-450/1-91-002, dated 5/91).
Air emissions must also comply with State regulations
identified as ARARs for this Site. Florida
regulations in Chapter 17-2 provides requirements for
sources which emit pollutants. If any contaminant
regulated by these standards will be released by the
planned remedial action, the regulations shall be
followed.
d. Design Standards
The design, construction and operation of the
groundwater treatment system shall be conducted in
accordance with all ARARs, including the pertinent
requirements set forth in 40 C.F.R. Part 264 (Subpart
F) .
C. Compliance Testing
46
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Sampling of treated and untreated soils, groundwater, treated
effluent, and air emissions shall be conducted at this Site.
Appropriate samples from soil or the extracted air/PCE
mixture shall be collected to ensure that PCE levels in soil
are less than or equal to 90 ppm. This sampling will be .
conducted in order to determine the effectiveness of the SVE
system. Verification samples will be collected to.
demonstrate that all soil that exceeds action levels has been
capped.
A long term monitoring system shall be implemented to monitor
the progress of groundwater remediation and the effectiveness
of continued operation of the groundwater treatment system. .
After demonstration of compliance with groundwater
Performance Standards, the groundwater shall be monitored for
at least five years. If monitoring indicates that the
Performance Standards set forth in Paragraph B.3 are being
exceeded at any time after pumping has been discontinued,
extraction and treatment of the ground water will recommence
until the Performance Standards are once again achieved.
Furthermore, if monitoring indicates Performance Standards
set forth in Paragraphs A.3 or B.3 have been exceeded, the
effectiveness of the source control component will be
re-evaluated. .
Treated groundwater will also be monitored on a regular basis
to ensure that the treated water meets the necessary
discharge standards. Discharge standards include federal-and
.state groundwater standards for discharges to the -aquifer.
An appropriate sampling and analysis plan for the remedial
action will be prepared during the RD. In addition to
analyses of organic contaminants, inorganic contaminants will
be analyzed periodically during the first two years of .
operation. After two years, the frequency of metals analyses
may be reduced.. If, at any time, metals .are present above
federal or state standards, then treatment for metals may.be
deemed by EPA to be necessary, dependent upon the discharge
point and associated discharge standards.
Air emissions monitoring will be performed periodically
during the remedial action to evaluate the air emissions from
the groundwater treatment system and the SVE system to
determine if air emission controls are necessary.
Use of the capped area will follow the substantive
requirements found in 40 CFR 264.117 -.120 regarding post
closure care and use of property including, but not limited
to, maintenance, groundwater monitoring, post closure plans
and notices, etc.
10. STATUTORY DETERMINATIONS
EPA has determined that the selected remedy will satisfy the
statutory determinations of Section 121 of CERCLA. The
remedy will be protective of human health and the
47
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environment, will comply with ARARs (unless a
waiver is justified), will be cost effective,
permanent solutions and alternative treatment
the maximum extent practicable.
statutory
and will use
technologies to
Furthermore, the regulatory preference for treatment as a
principal element and the bias against off-site land disposal
of untreated wastes are satisfied to the exte~~ practicable.
10.1 Protection of Human Health and The Environment
The selected remedy protects human health and the
environment through treatment of the principal threat
in soil. PCE is considered a principal threat in soil
because it is the most mobile primary contaminant at
the Site. SVE will reduce the most elevated levels of
PCE in soil that act as a source of groundwater
contamination at the Site. The subsequent cap over the
soil containing any remaining PCE and the various
metals will further reduce the generation of leachate
which contaminates the underlying groundwater. The cap
will also greatly reduce the risk of direct exposure
associated with the contaminated soil. Installation of
a cap will reduce the cancer risks associated with soil
contact to less than 1 x 10-6; the non-carcinogenic
hazard index will be reduced below 1.
The groundwater treatment component of the selected
remedy will protect human health and the environment by
reducing or preventing further migration of the
contaminated groundwater and by reducing the
contaminant concentrations in groundwater until the
concentrations are less than or equal to MCLs.
Compliance with MCLs will reduce the longterm cancer
risk associated with possible ingestion of the
groundwater to the range between lxlO-s and lxlO-6.
Periodic groundwater monitoring will be conducted to
evaluate the performance of the groundwater treatment
system.
10.2 Compliance with ARARs
Implementation of this remedy will comply with all
Federal and State ARARs and will not require a waiver.
The groundwater extraction and treatment system will
meet the groundwater performance standards noted in
Section 9.B.3, which are based on Federal and State
MCLs or EPA action levels. Federal and State MCLs are
considered relevant and appropriate in the cleanup of
contaminated groundwater. . MCLs will be met with
respect to the discharge of treated groundwater and
long-term groundwater monitoring to assess progress and
effectiveness of cleanup.
The cap will comply with the substantive RCRA
48
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11.
requirements regarding the capping and closure. of
. hazardous waste units. These reqUirements include the
relevant portion$ of 40 CFR 264 Subparts F, G, and K
and are also discussed in Section 9.A.3.
Air emissions from the soil and groundwater treatment
systems shall comply with EPA Directive 9355.0-28 which
provides guidelines for the control. of air emissions.
from air stripping towers at Superfund groundwater
sites. In addition, State standards for air emissions
are found in FAC 17-2.300. . These standards would apply
if regulated pollutants were emitted during the.
remedial action.
10.3 Cost-Effectiveness
The selected remedy, alternative C-1~ is a cost
effective remedy. The total estimated present worth
cost of this alternativ.e. is approximately $1,868,900'.
. . which includes capital costs arid annual operation and
maintenance cost~. EPA has determined that the cost of
implementingt~e remedy is proportionate to the overall
effectiveness of the remedy and is a reasonable value.
10.4.Use of Permanent Solutions and Treatment Technologies
. The selected remedy uses permanent solutions and
treatment t.echnologies to the maximum extent
practicable. Groundwater extraction and treatment will
involve .ac.tive measures to reduce the toxic'ity,
mobility, and volume of contaminants' in groundwater. .
Soil treatment, through soil vapor extraction, involves
active treatment to address the PCE in soil which acts
as a source of contamination in the groundw~ter. PCE
is the most mobile Site contaminant.
10.5 Preference for' Treatment asa Principal Element
, .
The statutory preference for treatment will be met
because the selected remedy ipcludes .active treatment
for ground~ater and active .treatment for the most
mobile soil contaminant;:s. ' Groundwater remediation will
be accomplished' through extraction and air stripping of
the contaminated groundwater. Air stripping will'
remove the VOCs from groundwater and discharge them to
. the air at levels that will not pose an unacceptable
level 9f risk to ,human health or the environment.
Treatment for the PCE c:::ontaminated soil, ,soil vapor
extraction, will,reduce the amount of PCE.that leaches
from soil. to groundwater and thus increase the' .
effectiveness of the groundwater treatment system.
DOCUMENTATION OF SIGNIFICANT CHANGES
The remedy described in this Record of Decision is the
preferred alternative described in the Proposed Plan for
49
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this Site. There have been no significant changes in the
selected remedy.
50
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APPENDIX. A:
ADMINISTRATIVE RECORD INDEX
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FINAL,' 10/13/93
Page 1
ADMINISTRATIVE RECORD INDEX,
for the
AIRCO PLATING CO INC NPL Site
1.0
PRE~REMEDIAL
1,8
PrelLminary Assessment Documents
1. Preliminary Assessment, Airco Plating Company Site,
Eric Nuzie, State of Florida Department of
Environmental Regulation. (September 20, ,1984).
2. Preliminary Assessment, Airco Plating Company Site,
Camilla Warren, EPA Region 'IV~ (May 20, 1985).
1,.9
Site Inspection Documents
1. Site Inspection, Airco Plating Company Site, Kenneth
Richardson, EPA Region IV. (April 24, 1985).
2. Site Inspection, Airco Plating Company Site, Kenneth
Barry, EPA Region IV., (January 29, 19861.
3. Site Inspection, Airco Plating Company Site, Kenneth
Richardson, EPA Region IV (May 19, 1986).
1.10
Expanded Site Inspection 'Documents
1. "Report, Airco Plating Company, Miami, -Florida," EPA
Region IV. (September 16, 1986).
2. "Final Expanded Site Investigation, llirco Plating'
Company Site, Miami, Fl.orida, Volume IIi Apperidices~"
NUS Corporation., [Note: Thesetwo volumes appear in
reverse order in th~ Index because of their approval
dates. However, they appear in correct volume order ~n '
the Administrative Record itself.] (July 1987).
3. "Final Expanded Site Investigation, Airco, Plating
Company Site, Miami, Florida, Volume I," NUS
Corporation. [Note: ThesetwQ volumes appear in reverse
order in the Index because of their approval dates.
However, they appear in correct volume order in the'
Admi~istrative Record itself.] (July 1988). ,
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FINAL, 10/13/93
Page 2
3.0
REMEDIAL INVESTIGATION (RI)
3.4
Work Plans and Progress Reports (cont'd.)
1. Letter from David Ferrell, United States Department of
the Interior, to Randy Bryant, EPA Region IV.
(February 12, 1991). Concerning the United States
Department of the Interior's choice not to comment on
the Airco Plating RI/FS.
2. Letter from Alex Cordero, Florida Department of
Natural Resources, to Randy Bryant, EPA Region IV.
(May 8, 1991). Concerning comments on the Revised
Work Plan for the RI/FS.
3. "Remedial Investigation and Feasibility Study Work
Plan, Airco Plating Company, Inc.," Prepared for Airco
Plating Company, by M.P. Brown & Associates, Inc.
(June 1991).
3.8
Interim Deliverables
1. "Site Safety and Health Plan, Airco Plating Company,
Inc., Miami, Florida," Prepared for Airco Plating
Company, by M.P. Brown & Associates, Inc. (June 1991).
2. "Quality Assurance Project Plan for Airco Plating
Company, Inc., Miami, Florida," Prepared for Airco
Plating Company, by M.P. Brown & Associates, Inc.
(June 1991).
3. "Field Sampling and Analysis Plan, Airco Plating
Company, Inc., Miami, F lor ida," Prepared for Airco
Plating Company, by M.P. Brown & Associates, Inc.
(June 1991).
3.10
Remedial Investigation (RI) Reports
1. Memorandum from Dan Thoman, EPA Region IV
Environmental Services Division, Athens, Georgia, to
Randy Bryant, EPA Region IV. (May 15, 1992).
Concerning comments on the Airco Plating Remedial
Investigation Report.
2. Memorandum from William O'Steen, EPA Region IV, to
Randy Bryant, EPA Region IV. (May 19, 1992).
Concerning Comments on the Airco Plating Draft
Remedial Investigation Report.
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FINAL, 10/13/93
Page 3
3.10
Remedial Investigation (RI) Reports (cont'd.)
3. Letter from Kelsey Helton, State of Florida Department
of Environmental Regulation, to Randy Bryant, EPA
Region IV. (July 9, 1992). Concerning transmittal of
the enclosed comments on the draft Site Source "
Characterization (Remedial Investigation Report) for
the Airco Plating Co. NPL Site. "
4~ Letter from Randy Bryant, EPA Region IV, to ~ke King,
Airco Plating Company, Inc. (July 14, 1992).
"Concerning transmittal of EPA's encl~sed comments on
the draft'Remediat Investigation Report for Airco
'Plating ComI>any NPL Site. ' ""
5. Memorandum from William O'Steen, EPA Region, IV, to
Randy Bryant, EPA Region IV. (November 5, 1992). '
Concerning transmittal of the enclosed comments on the
Airco Plating Revised Draft Remedial Investigation
Report. '
6. Letter from Randy Bryant, EPA Region IV, to Charles
MacPhearson, Haztech. (November 20, 1992). Concerning
transmittal of the enclosed comments, on the Revised"
Remedial Inves'tigation Report as' well as scheduling of
the Remedial Investigation Report and Feasibility
Study Report Documents for the Airco Plating Company
Site. ' , "
7. Letter from Kelsey Helton, State of Florida Department
of Environmental Regulation, to Randy Bryant, EPA
Region IV. (December 7, 1992). Concerning transmittal,
of the enclosed comments on the Site Source '
Characterization (Remedial Investigation Report) for
the Airco Plating Co. NPL Site. '
, '8. Letter from Randy Bryant, EPA Region IV, to Kelsey"
Helton, State of Florida Department of Environmental
Regulation. (Decembe"r 23, 1992). Concerning request
for review of the Final Remedial Investigation Report
and the Draft Technical Memorandum for Remedial
Alternatives (Provided) for the Airco Plating Co. NPL
Site.
9. Letter from Randy Bryant, EPA Region IV, to Charles,
"MacPhearson,Haztech. (January 8,1993). " Concerning
transmittal of the enclosed comments on the Revised
Remedial Investigation Report and ,Technical Memorandum
for the FS for the Airco Plating Company Site.
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FINAL, 10/13/93
Page 4
3.10
Remedial Investigation (RI) Reports (cont'd.)
10. Memorandum from William O'Steen, EPA Region IV, to
Randy Bryant, EPA Region IV. (January 22, 1993).
Concerning Comments on the Airco Plating Revised Draft
Remedial Investigation Report and Technical Memorandum
on Remedial Technologies and Alternatives.
11. Letter from Randy Bryant, EPA Region IV, to Charles
MacPhearson, Haztech. (January 28, 1993). Concerning
transmittal of the enclosed comments on the Revised
Remedial Investigation Report and Technical Memorandun.
for the FS for the Airco Plating Company Site.
12. "Remedial Investigation, Airco Plating NPL Site,
Miami, Florida, Volume' I, " M.P. Brown &1 Associates,
Inc., Prepared for Airco Plating Company, Inc.
(February 1993). '
13. "Remedial Investigation, Airco Plating NPL Site,
Miami, Florida, Volume II," M.P. Brown &1 Associates,
Inc., Prepared for Airco Plating Company, Inc.
(February 1993). .
14. Letter from Kelsey Helton, State of Florida Department
of Environmental Regulation, to Randy Bryant, EPA
Region IV. (February 12, 1993). Concerning the State
of Florida Department of Environmental Regulation's
comments on the Remedial Investigation Report and the
Technical Memorandum on Remedial Technologies and
Alternatives.
3.11
Health Assessments
1. "Interim Preliminary Health Assessment, Airco Plating
Company, Inc., Miami, Dade County, Florida," Agency
for Toxic Substances and Disease Registry (ATSDR) .
(February 26, 1992).
3.12
Endangerment Assessments
1. Memorandum from Elmer Akin,
Bryant, EPA Region IV. (May
attached review comments by
contractor, on the Baseline
Airco Plating Co. NPL Site.
2. Letter from Randy Bryant, EPA Region IV, to Cody
Jackson, Dynamac Corporation. (July 1, 1992).
Concerning the attached comments on the Baseline
Assessment for the Airco Plating Co. NPL Site.
EPA Region IV, to Randy
6, 1992). Concerning the
Krista Jones, onsite ESAT
Risk Assessment for the
Risk
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FINAL, 10/13/93
Page 5
3.12
Endangerment Assessments (cont'd.)
3. Letter from Randy Bryant, EPARegion .IV, to Cody
. Jackson, Dynamac Corporation. (November 5, 1992)..
Concerning the attached comments on the Revised. . .
Baseline Risk Assessment for the Airco Plating Co. NPL
Site. . ..
4. Memorandum from Elmer Akin, EPA Regi,on IV, to Randy
Bryant, EPA Region IV. (January 29, 1993). Concerning
the attached review comments by Krista Jones, onsite
ESAT contractor, on the .Revised Baseline Risk.
Assessment for the Airco Plating Co. NPL Site.
5. Letter from Randy Bryant, EPA Region IV, to Cody
J~ckson, Dy'namac Corporation. (February 24, 1993)~
Concerning the attached comments on the Revised
Baseline Risk Assessment for the Airco Plating Co. NPL
Site. . .
6. "Revised Final Baseline Risk Assessment, Airco.P1ating
Company Site, Miami, Dade County, Florida," Dynamac
Corporation. (March 19, 1993).
7. Memor~ndum from EIIDer Akin,. EPA Region IV, to Randy
Bryant, EPA Reg~on IV. (April 8, 1993). Concerning
the attached review comments by Krista Jones, onsite
ESAT.contractor, concurring on the Revised Baseline
Risk Assessment for the Airco Plating Co. NPL Site.
4.0
FEASIBI~ITY STUDY (FS).
. . - .. . - .
4.8
Interim Deliverables
1. "Technical Memorandum on Remedial Technologies and
. . Alternatives for Airco Plating. NPL Site, Miami,FL,~I.
Blasland, Bouck & Lee, and Haztech, for Airco Plating
Company, Inc. (December 1992).
2. Cross-Reference: Letter from Randy Bryant, EPA Region
. IV, to Kelsey Helton, State of Florida Department of
Environmental Regulation. (December 23, 1992).
Concerning request for review of the Final Remedial
Investigation Report and the Draft Technical
Memorandum for Remedial Alternatives (provided) for
the Airco Plating Co. NPL Site. [Filed and cited as
entry number 8 in 3.10 REMEDIAL INVESTIGATION (RI) -
Remedial Investigation (RI) Reports]
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FINAL, 10/13/93
4.0
Page 6
FEASIBILITY STUDY (FS)
4.8
Interim Deliverables (cont'd.)
3. Cross-Reference: Letter from Randy Bryant, EPA Region
IV, to Charles MacPhearson, Haztech. (January 8,
1993). Concerning transmittal of the enclosed
comments on the Revised Remedial In~estigation Report
and Technical Memorandum for the FS for the Airco
Plating Company Site. [Filed and cited as entry
number 9 in 3.10 REMEDIAL INVESTIGATION (RI) -
Remedial Investigation (RI) Reports]
4. Cross-Reference: Memorandum from WilliamO'Steen, EPA
Region IV, to Randy Bryant, EPA Region IV. (January
22, 1993). Concerning Comments on the Airco Plating
Revised Draft Remedial Investigation Report and
Technical Memorandum on Remedial Technologies and
Alternatives. [Filed and cited as entry number 10 in
3.10 REMEDIAL INVESTIGATION (RI) - Remedial
Investigation (RI) Reports]
5. Cross-Reference: Letter from Randy Bryant, EPA Region
IV, to Charles MacPhearson, Haztech. (January 28,
1993). Concerning transmittal of the enclosed
comments on the Revised Remedial Investigation Report
and Technical Memorandum for the FS for the Airco
Plating Company Site. [Filed and cited as entry
number 11 in 3.10 REMEDIAL INVESTIGATION (RI) -
Remedial Investigation (RI) Reports]
4.9
6. Cross-Reference: Letter from Kelsey Helton, State of
Florida Department of Environmental Regulation, to
Randy Bryant, EPA Region IV. (February 12, 1993).
Concerning the State of Florida Depa~tment of
Environmental Regulation's comments on the Remedial
Investigation Report and the Technical Memorandum on
Remedial Technologies and Alternatives. [Filed and
cited as entry number 14 in 3.10 REMEDIAL
INVESTIGATION (RI) - Remedial Investigation (RI)
Reports]
Feasibility Study (FS) Reports
1. Cross-Reference: Letter from Randy Bryant, EPA Region
IV, to Charles MacPhearson, Haztech. (November 20,
1992~. Concerning transmittal of the enclosed
comments on the Revised Remedial Investigation Report
as well as scheduling of the Remedial Investigation
Report and Feasibility Study Report Documents for the
Airco Plating Company Site. [Filed and citea as entry
number 6 in 3.10 REMEDIAL INVESTIGATION (RI) -
Remedial Investigation (RI) Reports]
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FINAL, 10/13/93
Page 7
4.9
Feasibility Study (FS) Reports (cont'd.)
2. Memorandum from William O'Steen, :EPA Region IV, to
Randy Bryant, EPARegion IV. (March 8, 1993).
Concerning comments on the draft Feas.ibility Study
Report for the Airco Plating.Co.NPL Site.
3. Letter from Krista Jones, ManTech Environmental
Technology, to Eimer Akin, EPA Region IV. (March 9,
1993). Concerning comments on the draft Feasibility
Study Report for the Airco Plating Co. NPL Site~
4. Letter from Randy Bryant, EPA Region:rV, to Charles
MacPhearson, Haztech.. (March 25, 1993). Concerning
EPA Region IV review and comments on the ~aft
Feasib~lity Study Report for the Airco Plating Co. NPL
Site. .
. 5. Memorandum from R~ck Ruscito, State of Florida
. Department of Environmental Regulation, to Kelsey
Helton, State .of Florida Department of Environmental'
Regulation. (April 16, 1993). Concerning comments on
. the draft Feasibility Study Report for the Airco
Plating Co. NPL Site. .
. . .
. .
6. Memorandum from William O'Steen, EPA Region IV, to
Randy Bryant, EPA Region IV. (April 30, 1993). .
Concerning soil remediation goals, Airco Plating Co.
NPL Site. . .
.
. 7. Letter' from Charles MacPhearson, Haztech, to Randy
BrYant, EPA Region IV. (May 11, 1993) ..Concerning a
request for additional .time to produce the final
Feasibility Study Report for the Airco Plating Co. NFL
Site.
8. Letter. from Charles MacPhearson,Haztech, to Randy
Bryant, EPA Region IV. (May 26, 1993). Concerning
Haztech's position regarding some of EPA Region IV's'
comments on the draft Feasibility Study Report for the
Airco Plating Co. NPL'Site.
9. "Feasibility Study Report, Airco Plating NPL Site,
Miami, Florida," Haztech, Blasland & BO.uck Engineers,
P.c.', Blasland, Bouck & Lee, Engineers and Scientists, .
for Airco Plating Co., Inc. (May 26,.1993).
10. Letter from Kiber Environmental Services, Inc., to
Randy Bryant, EPA Region IV. (June 15,' 1993).
Concerning recent information relative to hydrogen
peroxide/ultra violet light treatment for organics.
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FINAL, 10/13/93
Page 8
4.9
Feasibility Study (FS) Reports (cont'd.)
11. Memorandum from William O'Steen, EPA Region IV, to
Randy Bryant, EPA Region IV. (June 16, 1993).
Concerning comments on the revised Feasibility Study
Report.
12. Letter from Randy Bryant, EPA Region IV, to Charles
MacPhearson, Haztech. (July 14, 1993). Concerning
transmittal of the enclosed review comments on the
Revised Feasibility Study Report for the Airco Plating
NPL Site.
13. Letter from Frederick Blickle, Blasland, Bouck & Lee,
to Randy Bryant, EPA Region IV. Response to EPA's
comments on the Feasibility Study (July 26, 1993).
4.10
Proposed plans for Selected Remedial Action
1. Letter from Randy Bryant, EPA Region IV, to Kelsey
Helton, State of Florida Department of Environmental
Regulation. (June 28, 1993). Concerning request for
review of and comments on the draft Proposed Plan for
the Airco Plating Co. NPL Site.
2. Letter from Alex Cordero, State of Florida Department
of Environmental Protection, to Randy Bryant, EPA
Region IV. (July 8, 1993). Concerning review comments
on the Proposed Plan for the Airco Plating NPL Site.
3. "Superfund Proposed Plan, Region IV, Airco Plating
Superfund Site, Miami, Florida," EPA Region IV. (July
14, 1993).
4. Letter from George King, Airco Plating Co. Inc., to
Randy Bryant, EPA Region IV. Comments on the proposed
remedy for the Airco Plating Superfund Site (August
17, 1993).
5. Letter from Damon Marunyak, Ecozone, Inc., to Randy
Bryant, EPA Region IV, with attached letter to Chuck
MacPhearson, KibeI Environmental, from Damon Marunyak,
Ecozone. Summary of technology and test results using
an Advanced Oxidation Process (AOP) (August 27, 1993).
6. Cross-Reference: Letter from Kelsey Helton, Florida
Department of Environmental Protection, to Randy
Bryant, EPA Region IV. Review of the draft Record of
Decision (ROD) (September 3, 1993). [Filed and
cited as entry number 1 in 5.9 RECORD OF DECISION
(ROD) - Record of Decision (ROD)]
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FINAL, 10/13/93
Page 9
5.0
. RECORD OF DECISION (ROD)
5!9
Record of Decision (ROD) (cont'd.)
1. Letter from Kelsey Helton, Florida Department of
Environmental Protection, to Randy Bryant, EPA.Region '
IV. Review of the draft Record of Decision (ROD)
(September 3, 1993)'. '
'2. "Record of Decision, Airco Plating, Co. Inc. Dade
County" (October 1, 1993).
ENFORCEMENT'
10.0
10.11 EPA Administrative Orders
1. Administrative Order by Consent for Remedial
investig'ation/Feasibili ty Study', "In the Matter of
Airco 'Plating Company, Inc., Respondent," EPA Region
IV, (Includes Scope of Work)~ (November 14, 1990).
13.0
COMMUNITY RELATIONS
13.6.
Community Relations Plans
1. "Final Community Relations Plan, Airco Plating Company,
Site, Miami, Dade County, Florida," Dynamac
Corporation. (March 22, 1991).
13.7
News Clippings and Press Releases
1. Public Meeting Announcement' (in Spanish), EPA Region
IV, Newspaper Advertisement, Diario Las Americas.
(April 21, 1991).
'2. "Airco Plating Company, National Priorities List;
Superfund Site, Public Availability Session," .EPA
Region IV. (April 30, 1991). .
. 3. "The United States Environmental Protection Agency
Announces a Comment Period 'and Public Meeting for 'the.
Airco Plating Superfund Site, Newspaper Advertisement,
appeared in the Miami Herald (July 18, 1993).
4. Environmental Protection Agency announces a public
comment 'period and meeting (in Spanish), Newspaper
Advertisement, appeared in Diario Las Americas (July'
20,1993).
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FINAL, 10/13/93
Page 10
13.7
News Clippings and Press Releases (cont'd.)
5. Newspaper article outlining the Proposed Plan for
Airco Plating Superfund Site, (in Spanish), EPA Region
IV, appeared in Diario Las Americas (August 5, 1993).
13.8
Public Meetings
1. Transcript, "The Airco Plating Superfund Site, Public
Information Meeting", held at the Joseph Caleb Center
(August 2, 1993).
13.9
Fact Sheets
1. "Superfund Proposed Activities Fact Sheet, Airco
Plating Site," EPA Region IV. (May 1991).
2. Hoja De Hechos Sobre Actividades Propuestas Del
programa "Superfund," Predio Superfund De La Airco
Plating Company (Superfund Proposed Activities Fact
Sheet, in Spanish), EPA Region IV. (May 1991).
16.0
NATURAL RESOURCE TRUSTEE
16.1
Correspondence
1. Cross-Reference: Letter from David Ferrell, United
States Department of the Interior, to Randy Bryant,
EPA Region IV. (February 12, 1991). Concerning the
United States Department of the Interior's choice not
to comment on the Airco Plating RI/FS. [Filed and
cited as entry number 1 in 3.4 REMEDIAL INVESTIGATION
(RI) - Work Plans and Progress Reports]
2. Letter from Susan Goggin, State of Florida Department
of Environmental Regulation, to Randy Bryant, EPA
Region IV. (January 26, 1993). Concerning the fact
that the Florida Department of Environmental
Regulation is a natural resource trustee, and should
therefore should continue to have the opportunity to
review and comment on documents associated with the
Airco Plating NPL Site.
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FINAL,' 10/13/93
Page 11
16.0
NATURAL RESOURCE TRUSTEE
16.1 . Correspondence (cont.'d.)
3. Letter f~omAlex Cordero, Florida Department of
.Natural Resources; to Randy Bryant, EPA Region IV.
(February 5, 1993). Concerning a request to review.
.Airco Plating Remedial Investigation/Feasibility Study
. Report documents in light of the natural resource
trustee status of the Florida Department of Natural
Resources. .
17.0
SITE MANAGEMENT RECORDS
17.8 . State and Local Technical Records
1. Facsimile from Omar Prieto,' .Dade.County, to Randy
Bryant EPA Region IV, of a letter from JQhn Renfrow, .
Dade County, Flor~da, to George King, Airco Plating
Co. (June 23, 1993). . Concerning transmittal of the
enclosed Multiple Source Operating Permit for the
Airco Plating Co.
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APPENDIX B:
RESPONSIVENESS SUMMARY
-------
APPENDIX B .
RESPONSIVENESS SUMMARY
AIRCO PLATING NPL SITE
RECORD OF DECISION
PART I:
Summary of Commentor's Major Issues and Concerns
A public. meeting was held on August 2,. 1993 at the Caleb
Business Center in Miami, Florida. The purpose of the meeting
was to discuss EPA's proposed plan for Superfund action at the
Airco Plating Site. The.proposed plan included groundwater
extraction and treatment via airstripping, soil vapor
~xtraction, and.a cap over contaminated soil. .
. .About .. nine people attended. the m~eting, including
representatives of Airco Plating, a newspaper reporter; and
two private citizens. No significant concerns about the
proposed cleanup were expressed during the meeting.
A.30-day public comment period on the.proposed plan began on
July 19 and concluded on August 18. Comments were received
from Airco Plating, Dade County Environmental Resources
Management (DERM), Florida Department of Environmental
Protection (FDEP) and a vendor of groundwater treatment
technologies. Airco Plating expressed support for the
proposed action, but expressed concerns about the accuraCy of
the Risk Asses.sment conducted by EPA, the fairness of the
Superfund laws, and the need for Site investigations. . DERM
verbally expressed some. hesitation to allow treated
groundwater to be discharged to the POTW because of.possible
capacity limitations. FDEP' s main concern was. that more
extensive soil. cleanup actions were necessary. The vendor
proposed a variation of an ultraviolet light groundwater
treatment system. .
. .
pAAT II.:
Con:unents and Responses
1.
One commenter wanted to emphasize EPA comments regarding the
limitations of pump and treat systems.
RESPONSE:EPA indicated the possible difficulty associated
with achieving MCLs for organic compounds in groundwater when
using a pump and treat system and that such a system should be
monitored on a regular basis to evaluate its continued
effectiveness towards meeting MCLs.
2 .
One commenter suggested that groundwater contamination at the
Site is due to groundwater contamination at the Miami Airport.
RESPONSE: As part of EPA's Biscayne Aquifer Study, conducted
in the 1980' s, groundwater samples were collected within an 80
square mile area that included the Miami Airport. The highest
concentration of PCE found in the study area was approximately
. .
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5.9 ppb. The highest concentration of PCE recently found in
groundwater underneath the Airco Plating property however, was
at least 4,000 ppb, which is at least 650 times higher than
the highest value noted in the Biscayne Aquifer Study.
Furthermore, during the Site-specific investigations, PCE was
not detected in upgradient monitoring wells which are located
about 150 feet northwest of the Site.
3.
One cornrnentor supported EPA' s statement that the need for
treatment of metals in groundwater can best be determined
during the Remedial Design because groundwater results to date
indicate that such treatment is not necessary.
RESPONSE: Currently, cadmium is present in concentrations
above its MCLs in shallow groundwater underneath the Airco
Plating property. However, once the pump and treat system is
operational and begins to draw in enough groundwater to
capture the PCE plume, the cadmium levels in the extracted
groundwater may be low enough that treatment for metals, such
as cadmium, may not be necessary before discharge. However,
if metals in the treated groundwater are present above
discharge standards, additional treatment may be necessary.
4.
A cornrnentor claimed that the most significant flaw in the
Baseline Risk Assessment (BRA) is the calculation of the
Hazard Index for the onsite worker.
RESPONSE: The Hazard Index of 1.3, was calculated correctly.
A review of the risk assessment reveals that the primary
component of the HI for the onsite worker is the ingestion of
soil containing cadmium and chromium. The soil concentrations
used in the calculations for soil ingestion were taken from
soil boring B-62. B-62 is located on the Airco Plating
property and is accessible to workers. Boring locations B-52
and B-70 may be covered by asphalt or concrete and contained
some of lowest levels of site contaminants; use of data from
these points would underestimate potential risk.
Use of sampling data from boring B-62 is appropriate because
the calculated 95 % upper confidence level (UCL) of average
soil concentrations for the onsite worker scenario was much
higher than the maximum value of the four sampling points
referenced, including B-62. EPA risk assessment guidance
indicates that when the UCL is higher than the maximum
detected value, then the maximum detected value should be
used, and that such an approach is reasonable. The BRA is
intended to provide conservative calculations of risk in order
to ensure protection of human health and the environment.
The HI of 1.3 for the onsite worker is a summation of the
hazard quotients (HQ) for exposure to surface soil. A
limitation of this approach is that it is bas.ed on the
assumption that dose additivity is most properly applied to
compounds that induce the same effect. The application of the
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5.'
HI approach to a number of compounds that are not expected to
induce the same type of effects or do not act by the same
~echanism could overestimate the potential for effects .It is .
appropriate to sum these chemicals as a screening approach but
if the HI is greater than unity as a consequence 'of summing
several HQs, it is appropriate .to segregate the compol.lnds 'by
effect and by mechanism of action~ The two major contributors
to the .HI of 1.3 are cadmiurri and chromium. These' two
chemicals do not have the same toxic effect and neither
chemical has an individual HQ greater than 1. .
A comment or noted that the depicted location of soil .boring.B-
70 changed during revision of. the .BRA and that such a change
may have an impact on the onsite worker scenario.
6.
RESPONSE: The depicted location of soil boring .B-701s'
ident~cal to the location noted in the RI report. The
sampling data from boring .B~70 was not used in the calculated
value of 1.3'for the Hazard Index for the onsite .worker.
A commentor noted that ,in the BRA,. it is not possible. to
arrive at the reported mean concentration of PCE when using
the reported concentrations of PCE in the upper one foot of
soil from locations .B-57, 62, 67, and 70.
RESPONSE: It.appears that the detected concentrations were
. used in the calculation of the' mean concentration of PCE at
those locations.' Nevertheless, the calculated mean
concentration was not used in the risk calculation and thus
does not affect the risk assessment conclusions.
7..
One commentor noted that, in the .BRA, the oral and dermal risk
calculations for the onsite worker are based on a revised
Fraction of Area NotCbvered (FI) value of I, but previously
the value. was considered.2. Thus, the area of exposure is
reportedly uncovered. It is not. clear how a worker would
actually be in proximity to these. areas, especially since
three of the four sampling points a.re covered.' . .'
RESPONSE: The FI term was changed from .2 to 1.0 at EPA's
request. The FI term should represent the fraction of
ingested soil that comes from the contaminated source. The FI
term should not represent the fraction of the area not.
covered. Since all of the exposed soil is contaminated, the
FI term should be 1.0. In other. words, 100% of the soil
ingested may come from the contaminated source. References to
this concept inadvertently appear as' footnotes in some tables
in the BRA, but' the concept was not used in the actual
calculation of risk.' .
8.
A commentor
of F (x) for
result, it
particulate'
suggested that, in the .BRA, the calculated value
x=3.1 shou~d be .00326 instead of .006468. As a
is not possible to further evaluate the air
concentrations and the . associated risk
-------
calculations.
RESPONSE: It appears that the value should be revised to
.00326. However, the calculated risks from inhalation of
particulate contaminants_were initially within an acceptable
risk range. If the F(x) value were revised, the net result of
this change is that the risk levels associated with inhalation
of air particulate would be even lower.
9.
A conunentor asked why the BRA states that -the noncarcinogenic
risk associated with dermal contact and inhalation of
contaminated soil is insignificant compared with the total
noncarcinogenic risks associated with soil exposure when those
two exposure routes account for 20% of the total
noncarcinogenic risk?
RESPONSE: Ingestion of contaminated soil contributes
approximately 80% of the calculated noncarcinogenic risk for
the onsite worker scenario; therefore, ingestion of
contaminated soil, with a Hazard Index of 1.1, is the most
significant exposure pathway. The other individual hazard
indices were much lower: dermal contact - .2; inhalation-
.0003.
10.
A conunentor suggested that the Rfds listed in table 8-4 of the
BRA do not match the Rfds listed in other tables.
RESPONSE: There are discrepancies in some reference doses
for DDT, trichloroethene, l,2-dichloroethene, antimony, and
cadmium. As an example, the correct Rfd for cadmium was used
in the risk calculations, but a different Rfd was used for the
calculation of soil remediation goals for cadmium. The net
result of the change is that the soil remediation goal for
cadmium would be reduced to about 135 ppm. However, this
revision would have no impact on the planned site cleanup
because the final cleanup level for cadmium in soil was
actually based on the protection of groundwater which is lower
than the revised soil remediation goal based on the risk
associated with direct contact.
The net impact upon the site cleanup of revising Rfds for the
other compounds is neglible. Rfds are listed correctly for
the remaining contaminants.
11.
A conunentor noted that, in the BRA, the particulate
concentrations were not calculated for VOCs in Table 5-1.
Also, the ambient concentration of particulate reported in
Table 5-1 for bis(2-ethylhexyl)phthalate is not used in the
risk calcL~ations for the onsite worker scenario as presented
in Appendix B.
RESPONSE: The particulate concentrations were not calculated
for VOCs because of their volatility. There is no currently
acceptable reference dose or cancer slope factor for
-------
inhalation of bis(2-ethyihexyl)phthalate. EPA generally
recommends the use of an ora~ toxicity value in place of an
inhalation toxicity value. unless the chemical is known to
cause a. local effect on the respiratory system. Using this
approach for for bis (2 -ethylhexyl) phthalate at this Site would
yield a risk level even lower than the acceptable range.. .
12,..
. ,.
One commentor noted that the number of soil borings used iri
the environmental. risk assessment (70) differ from the number
used in other sections of the report (71). You need to
precisely define the data set before any calculations are
performed. . .
. ,
RESPONSE: As npted in the BRA, ~nvironmental ri~kass6ciated
with expQsure., to contaminated' soil' was evaluated
, qualitatively,' not quantitatively,' Therefore, it is not,
appropriate to specify criteria for the calculation 'of
environmental risk due, to soil exposure, since no calculations
of this nature were performed.
13.
k commentor inquired how the' value of 2,000 ug/l for the
median lethal concentration of TeE was derived.
RESPONSE':. For trichloroethylene (TeE), the median lethal
concentrations (LCso) for acute toxicity testing of the water
flea', Daphnia maqna, ranged from 4:1,,000 ug/l to 100,000' ug/l
(USEPA, .Ambien't Water Quality Criteria for Trichloroethylene,
EPA-440/5-80-077, 1980). To be conservative, the lowest of
these concentrations 'was divided by a safety factor of 20
(page 169 of the Ecological Assessment), to address possible
effects on more sensitive species. The resulting
concentration is approximately 2,000 ug/l.
For vinyl chloride, the LCso of 406,000' ug/l was not shown in
the USEPA document uAmbient Water Quality Criteria for Vinyl'
Chlorideu, EPA-440/5-80-078, 1980. This number may have been
obtained from the AQUIRE database. . However, the maximum
ground water concentration of vinyl chloride (100 ug/l) was
far below the calculated benchmark (20, ;300 ug/l') 'for this'
'compound, indicating no risk to aquatic receptors in the
canal. .
14.
One commentor asked why p. 170 of the BRA refers to benchmark
value for TCE ,of 2,000 ug/l when a different value in used in
Table 10-8.
, .
RESPONSE: The text on page 170 of the, BRA should have used
the Florida surface water quality standard of 80.7 ug/l for
TCE, rather 'than a calculated concehtration., Table 10-8 of
.the EA does, in fact, use the Florida standard as the
benchmark for TeE.
15.
One commentor Suggested that the assumption in the BRA
regarding,the persistence of hexavalent chromium in natural
-------
16.
17.
18.
water is not defensible
RESPONSE: Table 10-8 of the EA compares the maximum total
chromium concentration in the ground water to the surface
water benchmark for chromium VI, as a worst-case scenario,
since no hexavalent chromium data were available.
One commentor noted that the State of Florida surface water
criterion for tetrachloroethene should have been used as a
benchmark in the BRA.
RESPONSE: The Florida standard for tetrachloroethylene (8.85
ug/l) should have been used as the surface water benchmark in
Table 10-8 of the EA. (The benchmark of 84 ug/l was actually
a calculated chronic toxicity screening number, based upon
toxicity test data for fewer than eight species.) Comparison
of the maximum ground water concentration for
tetrachloroethylene (11,000 ug/l) to the Florida standard for
this compound (8.85 ug/l) changes the Toxicity Unit from 131
to 1243, implying an increased risk to aquatic receptors.
One commentor noted that the EPA ambient water quality
criterion for acute toxicity for chloroform should be 289,000
ug/l and that the EPA ambient water quality criterion for
chronic toxicity for chloroform in freshwater is 1,240 ug/l
instead of 1,240 mg/l.
RESPONSE: The lowest acute toxicity concentration for
chloroform is given as 28,900 ug/l (not 289,000 ug/l) in the
USEPA document "Ambient Water Quality Criteria for
Chloroform", EPA- 440/5-80-033, 1980. The benchmark given in
Table 10-8 of the EA was apparently based upon the EPA Region
IV Waste Division surface water screening numbers. Since
acute toxicity data for fewer than eight species were
presented in the AWQC document for chloroform, the lowest
acute toxicity concentration was decreased by a factor of 10,
to account for possible effects on more sensitive species.
Apparently ,another factor of 10 was then applied to account
for chronic effects, yielding a chronic screening number of
289 ug/l for chloroform.
The chronic toxicity concentration (1240 ug/l) shown in the
AWQC document was also based upon toxicity data for fewer than
eight species. The chloroform concentration units on page 170
of the EA should be ug/l. If a factor of 10 is applied to
account for possible effects on more sensitive species, the
chronic screening number would become 124 ug /1, and the
Toxicity Unit would increase from 0.73 to 1.69.
One commentor
concentrations
agree In many
BRA.
noted that the reported maximum detected
of contaminants in Site groundwater did not
instances in Tables 10-4,-5,-6, and-B of the
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RESPONSE: A rev~ew of the tables in question.
data reported in Tables 10-4, -5, -6 do agree.
detected concentrations listed in 10-8 do not
.with the previous data and should be revised as
reveals that
The maximum
always agree
follows:
Contaminant
Groundwater Benchmark (ug/l) Toxicity Unit (ug/l)
concentration
(ug/l)
Acetone 7 NA NA
Chloroform 22 289 .076
1.2-dichloroethene 270 11.000 .025
Tetrachloro-ethene 4,000 84 47.6
Trichloroethene 42 80.7 .52
Vinyl Chloride 100 20,300 .005
. Cadmium 67 1.13. 59.2
Chromium. 260 11 23.7
Copper 49 11.8 4.15
Lead Npl 3.2 NA
Nickel 150 157.7 9.5
Zinc 680 . 106 6.4
Cyanide 24 5.2 4.6
Bis(2-ethylhexyl) 5.5 <.3 18.3
phthlate
Butylbenzyl .7 22 .03
phthalate
-uea.. was not aetectea 1n grounawater unaerneatn tne :>lte, DUt was aetecteu 1n an upgraa1ent weu.
19.
A commentor noted that data from. the first sampling of well
APS-10 was used in Table 10-8 of the BRA while. data from the
second sampling of well APS-10 was used in Tables 10-4, -5, and
-6. .
RESPONSE: Table 10-8 should have used the unfiltered data
from the second sampling of APS-10. If table 10-8 wer.e
revised accordingly, then thecalculatedtoxici ty units would
decrease for the s.ite related organic compounds, but would
increase for the inorganic compounds (because of conversion of
the inorganic results to ug/l). However, this measure. of
potential environmental risk was not ultimately used for the
remedy selection at this Site. because the likelihood of
exposure for organisms to Site groundwater is minimal.
20.
A commentor noted that the reported concentration of acetone
differs i'n certain sections of the BRA. In Table 3..,4, . the
value is reported as . ..0"075 mg/l. In Table 10-5, the value is
reported as .007J mg/l. . Such inconsistencies cast doubt. on
the reporting of data throughout the document.
RESPONSE: The two
represent values of
values are virtually the. same; both
approximately 7 parts per Dillion of
-------
acetone in groundwater. To suggest that there is any
significant difference between the two values and that such a
difference renders other data questionable, is unsupportable.
21.
One commentor suggested that the BRA is inconsistent with
regards to evaluation of the potential environmental impacts
of contaminated groundwater. The conclusions which are drawn
regarding the site-specific potential for ecological impacts
to offsite receptors is thereby weakened.
RESPONSE: The statement concerning the potential for Site
ground water contaminants to cause ecological impacts in the
Miami Canal (Summary section on page 173 of the risk
assessment) reflects a conservative evaluation, based upon
available data and information. This statement is later
qualified (on the same page) by mentioning that it does not
take into account factors such as dilution, dispersion,
adsorption, and biodegradation which could result in
attenuation of the ground water contaminants prior to, or
during, discharge to the canal. For clarity, this qualifier
should have directly followed the statement on potential
ecological efects. Also, the qualifier could have been
reworded to state more directly that some degree of
attenuation would be expected, but the degree of such
attenuation has not been determined.
The ROD states that there is little likelihood for any
negati ve impacts to the Miami Canal due to contaminated
groundwater migrating from the Site. Continued monitoring of
the contaminated groundwater will be used to confirm this
statement.
22.
Airco Plating resubmitted its comments on the draft BRA dated
April 1992.
RESPONSE: EPA had earlier received and reviewed these
comments, and incorporated these comments where appropriate
in subsequent revisions to the BRA. The draft BRA was not
used as a basis for the final remedy selection.
23.
A commentor asked why a cleanup is necessary since Airco
Plating had a permit to operate the percolation ponds.
RESPONSE: The presence of metals, cyanide, and PCE in soil
and groundwater at this Site constitutes a release of
hazardous substances as defined in CERCLA and SARA (the
Superfund laws). EPA is required to investigate and remediate
such releases when necessary to protect human health and the
environment.
24.
A commentor questioned the conclusions of an earlier Expanded
Site Investigation (ESI) and also why it was necessary to
perform both an ESI and a Remedial Investigation (RI) at the
Site.
-------
RESPONSE: The ESI was conducted during 19'87-1988. The data
from the ESI were used to determine if the Site should be'
placed on the NPL and to facilitate planning for subsequent
investigations.
Results of the ESI indicated the presence of various metals,
cyanide, and PCEin soil and metals and PCE in groundwater.
. The ESI' concluded that the environmental impact associated
with this 'site was estimated to be negligible because of. its
location in urban area. ".
However, the ESI went on to state that ....themost
significant public welfare impact is the potential loss of a
portion of the Biscayne Aquifer asa drinking water source.p
. The Biscayne Aquifer, which ~der1ies this site, is the only
source of' drinking water for people in South' Florida~
particularly in Dade County. .
EPA did not agree with the conclusions of the ESI that the
Site could be moved directly to the Feasibility Study stage,
,but felt that additional RI sampling was necessary. The RI
provided further information not developed in the previous
sampling investigations. The RI further delineated the extent
of contamination, especially to the north, south, and west of
the covered percolation ponds previously used by Airco at the
Site. In addition, the RI identified, fQr the first time,
significant localized' PCE contamination of soil and shallow
groundwater at the Site. The RI also identified the presence
,of PCE contamination in deeper groundwater,' that had moved
further downgradient from the Site than was previously known.
Although Site related, this PCE contamination appears to be
unrelated to Airco's permitted use of the percolation ponds.
25.
One commentor claimed that EPA wanted to remove relevant
information regarding land use at the Site from RI/FS reports.
RESPONSE: A description ,of land use at and around the Site,'
including 'relevant zoning lnformation, is fui1y described in '
the RI Report, Section 2.4
26.
A commentor claimed that information in the Ris~ Assessment
should be repeated in the FS so that the FS can serve ,as a
stand alone document describing Site risk.
RESPONSE: Given the complexities and difficult issues
associated with Superfund sites, it is not appropriate for the
FS to serve as a stand alone document. The Record of Decision
summarizes all relevant information regarding remedy
selection. . In addition, the administrative record for this
Site contains documents relied upon in the remedy selection
process. The documents for this Site including sampling'
information, zoning information, risk assessment cal.c'u1ations,
remedial alternatives, etc. are available at the John F.
Kennedy Library in Hialeah,' Florida and EPA Region IV in
-------
27.
28.
29.
30.
Atlanta, Georgia.
One commentor stated that the development of future work plans
for Site actions could be accelerated if EPA were not so
"picky. "
RESPONSE: EPA will approve future work plans at such time as
they are determined to comply with appropriate regulations and
guidance and satisfy Site specific considerations.
A commentor submitted a
light/proprietary catalyst
groundwater at the Site.
proposal for an
system to treat
ultraviolet
contaminated
RESPONSE: A similar system was evaluated in the FS for this
Site. Such systems can be effective in destroying most VOCs
in groundwater. However, according to the FS, this type of
system is not cost effective when compared with air stripping
and thus was not chosen as the Site remedy. The commentor's
estimate appears to be approximately equal to the cost
estimate in the FS. .
The commentor reported that its system could also treat
metals, along with the VOCs, in groundwater. Air stripping
does not treat metals in groundwater. The need for treatment
of metals in groundwater will be determined during the RD
phase of the project. If metals treatment is combined with
the air stripping system, then it may be worthwhile to
reevaluate the total costs of the combined treatment process
to the total costs of other systems, including the commentor's
proposed system.
DERM expressed some concern about the potential discharge of
a portion of the treated groundwater through Airco Plating's
existing sewer discharge permit, primarily due to system-wide
capacity limitations. Currently I if such a discharge was
undertaken, both County and Federal approval of the discharge
would be necessary due to a Federal suit regarding the Miami-
Dade Sewer system.
RESPONSE: The ROD suggests two possible discharge options for
treated groundwater: 1) the POTW and/or 2) an on-site recharge
gallery. The recharge gallery is feasible and would be easier
to implement at this time. However, a discharge to the POTW
via the facility's existing discharge permit should not be
ruled out because limitations on this option may be lifted in
the future. .
FDEP recommended that the ROD adopt soil cleanup levels for
Site contaminants (in addition to those already established
for PCE and cadmium) including cyanide, chromium, lead and
zinc because these soil contaminants are acting as 9 source of
groundwater contamination. These cleanup levels, as developed
by the State, should be protective of human health under a
-------
31.
32.
future industrial scenario which assumes unlimited exposure to
Site contaminants.
RESPONSE: These additional contaminants are not present at
signifiCant levels in Site groundwater and thus soil cleanup
levels to protect groundwater are not' necessary. Chromium has
been detected in only one well at levels above its MCL. Leaq
was detected in one upgradient well and was not present in
Si te groundwater.. Cyanide was detected. above MCLs in one
turbid sample from a well that was later resampledi cyanide
was below MCLs in those latter samples. Zinc was not detected
above its SMCL in any groundwater sample.
Action levels for these. contaminants were .developed on the
basis of direct exposure to soil.. The risk assessment
calcul~tedsuch va~ues in Table' 8-4. Action levels.forthese
and other inorganic contaminants will be presented in the ROD
and used during :verification sampling to confirm that the soil
that requires action is addressed. .
. ,
A cleanup level for cadmium in soil that would be protective
of groundwater was calculated and was below the direct contact
cleanup level noted in the BRA. The more protective value was
established as the cleanup level. For the purposes of the
RI/FS, it is less cumbersome to refer to this single cleanup
level for inorganics because the other inorganic Site
contaminants tend to be. elevated when cadmium is. elevated.
Thus, action that addresses the cadmium contaminated soil will
also address soil contaminated with other inorganics.
A comment or stated that groundwater recovery should continue
until all' groundwater at. the Site contamin~nt. plume' is
remediated, not just the portions monitored by compliance
wells.' .
RESPONSE: The EPA document -Guidance on Remedial Actions for
Cbritam1nated Groundwater at Superfund Sites., EPA/540/G-
. . 88/003., 'indicates' that. it may not be appropriate tq require
compliance withgroundwater'standards' in those specific areaS
where wastes are managed in place. At this Site, such
guidance may apply to the former pond 'areas t:t1at will be
capped. Therefore, groundwater standards for metals should
not have to be met directly in the areas of the former ponds,
but at the immediate boundaries of those ponds. Monitoring of
the groundwater will be designed to detect the migration of
metals beyond the boundaries of the former ponds. EPA feels
that. this guidance would not apply to the, organic
contamination because the organic c'ompounds in so1.1 are being
actively remediatedi thus groundwater standards for the
organic contaminants shall be met throughout the extent of the
plume.
A commentor noted that Air emissions from the air stripper or
the SVE system must meet Florida's Air Quality Standards.
-------
33.
34.
35.
36.
37.
RESPONSE: The ROD refers generally to these standards as
ARARs. However, during the RD, the State should specify the
numerical values associated with these standards.
A commentor noted that the recharge gallery should be located
in such a way so that a recharge to the aquifer does not
result in splitting the plume or otherwise adversely changing
the migration pattern.
RESPONSE: These design considerations will be incorporated to
the extent possible.
One commentor stated that deed restrictions limiting future
use of the Site to industrial use must be enacted if the Site
is remediated to levels that are not protective of future
residential use.
RESPONSE: The deed restrictions will restrict residential use
of the Site because such use would not be consistent with the
cap to be installed over the contaminated soil.
One commentor noted that the nature of the intended cap and
its long term effectiveness is questionable.
RESPONSE: The cap is more fully described in Section 9.A.3.b
of the ROD: Performance Standards - Capping. With periodic
maintenance, the cap is expected to last approximately 30
years.
A commentor questioned the effectiveness
asphalt covers in reducing infiltration.
existing
of
the
RESPONSE: EPA agrees. That is why the existing covers will
be further evaluated during the RD to determine if they
deliver an acceptable level of performance. If the existing
covers do not meet the levels of effectiveness achieved by the
new cap, then the existing covers will be replaced by
expanding the new cap.
The State recommends that soil above the water table which
exceeds the metals cleanup levels be remediated by 1)
excavation and off-site disposal, or 2) excavated, solidified,
disposed of at the Site, and capped in order to control the
leaching of metals in groundwater.
RESPONSE: Similar alternatives were evaluated in the FS.
They would likely be very difficult to implement because of
the space constraints at the Site. In addition, excavation of
all metals contaminated soil would require the demolition of
some Site buildings, including the existing industrial
wastewater pretreatment plant and the replacement of the pipes
and sumps which feed the pretreatment plant.
The metals contamination in groundwater is generally limited
-------
to the shallow groundwater and has not migrated beyond Airco
Plating's property. Furthermore, the selected groundwater
action is expec.t::ed to capture the groundwater contaminated
with metals and will include treatment for metals in extracted
groundwater if necessary to satisfy discharge requirements.
Groundwater monitoring is a component of the selected remedy.
If long term monitoring indicates that the .cap is' not
effective in reducing metals concentrations in groundwater,
then .it may be necessary to conduct more active soil
remediation measures. .
-------
APPENDIX C:
SUMMARY OF RISK ASSUMPTIONS/CALCULATIONS
-------
The major assumptions about exposure frequency and "duration that
were included in the exposure assessment were:
" .
.
The most likely trespasser is a male, age 9-18.
.
The trespasser will visit the Site on a routine basis
.for 10 years (age 9-18) .
.
The trespasser will visit the Site 39 .days per year
(one day per week for nine months)
.
. "
The average body weight of the trespasser is 50.5 kg.
.
The soil ingestion rate for the trespasser is 100
.mg/day.
The resident will spend 24 hours per day, 350 days per
year onsite..
.
Residents will drink 2 liters of water per day.
The resident child lives on the Site for the six-year
period from ages Ito 6. The resident adult lives on
. the Site for 30 years.
.
The " average weight of the child is 15 kg over the nine-
year period. The average weight of the adult is 70 kg.
The soil ing~stion rate of the resident. child is 200 . ..
mg/day. The soil ingestion rate for the resident adui~
is 100 mg/day. .
. .
.
The average body weight of the on-site worker is 70 kg.
The on-site worker will spend 250 daY$ per year onsite.
. .
.
The on-site worker will work at the Site for 25 years.
..
The soil ingestion rate for the on-site. worker is 50
mg/day.
-------
T ABL E EXPOSURE POINT CONCENTRATIONS FOR SOIL (in ppm)
Chemical Exposure Scenarios
On-site Off-site Future
worker trespasser Resident
Antimony ND ND 39.6
Arsenic ND ND 4
Cadmium 770 1400 1400
Chromium 3100 5150 5300
Copper 290 1400 1200
Cyanide 1000 2950 3100
Lead 220 . 180 1381
Nickel 140 760 760
Zinc 5600 13000 13700
PCE .570 2.8 230
Th.BLE EXPOSURE POINT CONCENTRATIONS IN GROUNDWATER (in ppm)
Chemical Exposure Scenario
Future Resident
Cadmium .023
Chromium .055
Copper .049
Nickel .056
Zinc .284
Bis (2-ethyhexyl) phthalate .006
Chloroform .022
1,1-dichloroethene .011
1,2-dichloroethene .144
PCE 2.6
TCE (trichloroethene) .01
vinyl chloride .05
-------
. TES VIII WORK ASSIGNMENT NO. C04084 .
AIReO PLATING COMPANY SITE. BASELINE RISK ASSESSMENT
CALCULATION Of AVERAGE DAILY INTAKE fOR ONSITE WORKER
NONCARCINOGENS SOIL AMBIENT AIR 'PATH.SPEClfIC PATH.SPEClfIC PATH.SPEClfIC AV<3. DAILY AVG.DAIL AVG. DAILY JNHALED ORAL DERMAL RISK FRO
SURfACE SOIL CONCENT CONCENTR. INT AKE fACTOR INTAKE FACTO INTAKE fACTOR INTAKE INTAKE INTAKE REF. REF. REF. RISK. FROM RISK FROM DERMAL
CONTA~INANT (mgIl<9) (mg/mA3) IWHALA TlON INGESTION DERMAL CONTACT INHALATION INGESTION DERMAL DOSE DOSE DOSE INHALATION INGESTION CONTACT
ACETONE NO NO 0.19 4.8E.07 1.9E.07 O.OE+oo NA NA NA 1.0E.01 2.0E.02 NA NA NA
CHLOROfORM NO NO 0.19 4.8E.07 1.9E .07 O.OE+oo NA NA NA 1.0E.02 2.0E.03 . NA NA NA
TETRACHLOROETHYLE 0.57 3.3E.04 , 0.19 4.8E.07 1.9E.07 6.3E .05 2.7E.07 1.1 E .07 NA 1.0E.02 2.0E.03 NA 2.7E.05 5.4E.05
TRICHLOROETHYLENE NO NO 0.19 4.8E.07 1.9E.07 O.OE+oo NA NA NA 6.0E.03 I.2E.03 NA ! NA NA
CADMIUM 770 2.5E.10 0.19 4.8E.07 1.9E.08 4.8E.11 3.7E.04 \.5E.05' NA 5.0E-04 1.0E.04 NA 7.4E.01 1.5E-01
CHROMIUM 3100 9.1E.10 0.19 4.8E.07 1.9E,08 1.7E-10 1.5E.03 5.9E.05 5.7E.07 5.0E.03 1.0E.03 3.0E.04 3.0E.01 5.9E-02
COPPER 290 2.2E.10 0.\9 4.8E.07 1.9E.08 4.2E.I\ 1.4E-04 5.5E-06 NA 3.7E.02 7.4E.03 NA 3.8E.03 7.4E.04
LEAD 220 4.0E.11 0.19 4.8E-07 1.9E.08 .7.6E.12 1.1 E.04 4.2E.06 NA NA NA NA NA NA
NICKEL 140 1.4E.10 0.19 4.8E.07 1.9E.08 2.7E.11 6.7E.05 2.7E-06 NA 2.0E-02 4.0E.03 NA 3.4E.03 6.7E.04
ZINC 5600 2.4E.09 0.19 4.8E-07 1.9E.08 4.~E.10 2.7E.03 1.1E-04 NA 3.0E.01 6.0E.02 NA 9.0E.03 1.8E.03
CYANIDE' 1000 5.3E.10 0.19 4.8E.07 1.9E.08 \.OE.\O 4.8E.04 1.9E-05 NA 2.2E.02 4.4E.03 NA 2.2E-02 4.3E.03
ANTIMONY NO NO 0.19 4.8E.07 \.9E'08 O.OE+oo O.OE+oo O.OE+oo NA 4 .0E.04 8.0E.05 NA NA NA
ARSENIC NO NO 0.19 4.8E.07 1.9E.08 ' O.OE+oo O.OE+oo O.OE+oo NA 3.0E.04 6.0E.05 NA NA NA
B\S(2.ETHYLHEXYL)PHT NO NO 0.19 4.8E-07 1.9E.07 O.OE+oo NA . NA NA. 2.0E-02 4.0E.03 NA NA NA
4.4' OOT NO NO 0.19 4.8E.07 1.9E.07 O.OE+oo NA NA NA NA NA NA NA NA
4.4 OOE NO NO 0.19 4.8E.07 1.9E.07 O.OE+oo NA NA NA NA NA NA NA NA
.
TOTAL 3.0E.04 1.1 E+oo 2.1E-0\
CARCINOGENS SOIL AMBIENT AIR PATH. SPECifiC PATH.SPECIFIC. PATH.SPECIFIC AVG.OAILY AVG. DAIL A VG. DAILY INHALED ORAL DERMAL RISK FRO
SURfACESOIL CONCEN CONCENTR. INTAKE fACTOR INTAKE FACTO INTAKE FACTOR INTAKE INTAKE INTAKE SLOPE SLOPE SLOPE RISK FROM RISK FROM DERMAL'
CONTAMINANT (mgi'Kg) (mgIm"3)" INHALA TlON INGESTION OERMAL CONTACT INHALATION INGESTION DERMAL FACTOR FACTOR FACTOR INHALATIO INGESTION CONTACT
ACETONE NO NO 0.07 1.75E .07 7.0E.08 NA NA NA NA NA NA NA NA NA
CHLOROFORM NO NO 0.07 1.75E.07 7.0E.08 NA NA NA 8,IE.02 6.IE.03 3.1E.02 NA NA NA
TETRACHLOAOETHYLE 0.57 3.3E.04 0.07 1.75E .07 7 .0E.08 2.3E.05 1.0E-07 4.0E-08 1.8E.03 5.IE-02 2.5E-01 4.2E.oe 5.1E.09 1.0E-08
TRICHLOAOETHYLE NE NO NO 0.07 1.75E .07 7.0E.08 NA O.OE+oo O.OE+oo 1.7E.02 1.1 E-02 5.5E.02 NA NA NA
CADMIUM - 770 2.5E.10 0.07 1.75E.07 7.0E.09 1.8E.11 1.3E-04 5.4E.06 6.1E+00 NA NA 1.IE.10 NA NA
CHROMIUM 3100 9.IE.10 0.07 1.75E.07 7.0E.09 6.4E.11 5.4E.04 2.2E.05 4. fE+OI NA NA 2.6E.09 NA NA
COPPER 290 2.2E.10 0.07 1.75E-07 7.0E.09 1.5E.11 5.1E.05 2.0E-06 NA NA NA NA NA NA
LEAD 220 4.0E.11 0.07 1.75E-07 . 7 .0E.09 2.8E.12 3.9E.05 I.5E.06 NA NA NA NA NA NA
NICKEL 140 1.4E.10 0.07 1.75E.07 . 7.0E.09 9.8E.12 2.5E.05 9.8E.07 1.7E+00 NA NA I.7E.\1 NA NA
ZINC 5600 2 .4E.09 0.07 1.75E.07 7 .0E.09 I.7E.10 9.8E-04 3.9E.05 NA NA NA NA NA NA
CYANIDE 1000 5.3E.10 0.07 1.75E.07 7.0E.09 3.7E.11 1.8E-04 7.0E'06 NA NA NA NA NA NA
ANTIMONY NO ND 0.07 1.75E.07 7 .0E.09 NA NA NA NA NA NA - NA NA NA
ARSENIC ND NO 0.07 '1.75E.07 7 .0E.09 NA NA NA 1.5E+01 1.8E+00 8.8E+00 NA NA NA
BIS(2.ETHYLHE XYLjPHT ND NO 0.07 1.75E.07. 7.0E.08 NA NA NA NA 1.4E-02 7.0E.02 NA NA NA
4.4' DOT NO ND 0.07 1.75E.07 7.0E-08 NA NA NA 3.4E.01 3.4E.0\ 1.7E+00 NA NA NA
4.4 DOE NO ND 0.07. U5E .07 7.0E.08' NA NA NA 3.4E.01 3.4E'01 1.7E+00 NA NA NA
...
TOTAL 4.4E.08 5.\E.09 1.0E-08
UNITS f~A PA1H.SPECIFIC INTAKE FACTORS ARE mA3/kgiday FOR INHALATION AND kglkg/day FOR INGEST ION AND DERMAL CONTACT
-------
TES VIII WORK ASSIGNMENT NO. C()4O&
-------
TES VIII WORK ASSIGNMENT NO. C040&4 .
AIR CO PLATING COMP~Y SITE - BASELINE RISK ASSESSMENT .
CALCULA TlON OF AVERAGE DAILY INTAKE FOR 'FUTURE ADULT RESIDENT
NONCARCINOGE NS SOIL AMBIENT AIR PATH.SPECIFIC pATH-SPECIFIC PATH. SPECIFIC AVG.DAltY AVG. DAILY AVG. DAILY INHAlED ORAL DERMAL RISK FRO
SURFACE SOIL CONCENl CONCE/lfTR. 1/IfT AKE I' ACTOR 1/IfT AKE FACTO INTAKE FACTOR 1/IfT AKE 'IT AKE SOIL 1/IfT AKE REF. REF. REF. RISK FROM RISK FROM DERMAl
CONTAMINANT (mgJkg) (mgJm"3) INHALATION INGESTION DERMAL CO/IfTACT INHALATION INGESTION DERMAl DOSE DOSE DOSE INHALA TlO INGESTION CONTACT
ACETONE 0.088 9.2E-05 0.27 1.~E.06 7.3E.07 2.5E-05 1.2E.07 6.~E-08 NA 1.0E-01 2.0E.02 NA I.2E.06 .3.2E.06
CLOROFORM 0.016 2.2E-05 0.27 I.~E.06' 7.3E-07 5.9E.06 2.2E-08 1.2E-08 NA 1.0E-02 2.0E-03 NA 2.2E-06 5.8E.06
TETRACHLOROETHYLE 230 1.1E-01 0.27 1.~E-06 7.3E.07 2.9E-02 3.2E-04 1.7E-04 NA I.OE-02 2.0E-03 NA 3.2E-02' 8.~E.02
T.RICHLOR()ETHYLENE 0.01 2.~E-05 0.27 1.4E-06 7.3E-07 6.5E.06 I.~E-08 7.3E-09 NA 6.0E-03 1.2E.03 NA . 2.3E-06 ) 6.1 E-06
CADMIUM 1~00 I.OE -09 0.27 UE.06 7.3E-08 2.7E.10 1.9E-03 1.0E-04 . NA 5.0E.04 1.0E-04 . NA 3.8E+00 1.0E+00
CHROMIUM 5300 3.8E -09 0.27 . 1.4E .06 7.3E.08 1.0E-09 7.31:.03 3.9E-04 5.71::07 5.0E.03 1.0E.03 1.8E-03 1.5E+00 3.9E.01
COPPER 1200 6.0E.10 0.27 1.4E .06 7.3E-08 1.6E.10 1.6E-03 8.81:-05 NA 3.7E.02 7.4E-03 NA 4.~E.02 I.2E.02
LEAD 1381 2 .8E.09 0.27 1.4E-06 7.3E.08 7.6E'10 1.9E.03 1.0E-04 NA NA NA /... NA NA
NICKEL 760 5.6E-10 0.27 1.4E.06 7.3E.08 1.5E.10 1.0E-03 5.5E-05 NA 2.oE.02 4.0E.03 NA 52E.02 1.~E.02
ZINC 13700 I.OE -08 0.27 1.4E.06 7.3E.08 2.7E.09 1.9E-02 1.0E-03 NA 3.0E.01 6.0E-02 NA 6.3E.02 1.7E-02
CYANIDE 3100 2.2E-og 0.27 I.~E.06 7.31:-08 5.9E.10 ~_2E-03 2.3E-04 NA 2 .2E .02 ~.~E-03 NA 1.9E.01 .5.1E-02
ANTIMONY 39.6 3.6E-11 0.27 UE.06 7.3E-08 9.7E-12 5.4E-05 2.9E-06 NA 4.0E-04 8.0E-05 NA 1.4E-01 3.6E-02
ARSENIC " 3.01:-12 0.27 1.4E.06 7.31:-08 8.11:.13 5.51:-06 2.9E-07 NA 3.0E-04 6.OE -OS NA 1.6E.02 4.9E-03
BIS(2-ETHYlHEXYL)PHT 0.31 2.2E.12 0.27 1.~E.06 7.3E-07 5.9E.13 ~.2E-07 2.3E-07 NA 2.0E.02 ~.OE-03 NA 2.1E-05 5.7E-05
~,~. DOT 0.058 ~.~I:-I~ 0.27. 1.~E-06 . 7.3E-07 1.2E.14 7.9E-08 4.2E-08 .NA NA NA NA NA NA
~.~ DOE 0.029 2.2E-I~ 0.27 1.4E.06 7.3E-07 5.gE-15 ~.OE.08 2.1E-08 NA NA NA NA' NA NA
TOTAL 1.8E-03 5.8E+00 .1.6E+00
CARCINOGENS SOIL AMBIENT AIR PATH. SPECIFIC PATH.SPECIFIC PATH.SPECIFIC AVG. DAILY AVO.DAIL AVG. DAILY INHALED. ORAL DERMAL RISK FRO
SURFACE SOIL CONCEN . CONCENTR. INTAKE FACTOR INTAKE FACTO INTAKE FACTOR INTAKE 1/IfT AKE 1/IfT AKE SLOPE SLOPE SLOPE RISK FROM RISK FROM DERMAL
,CONTAMINANT (mglkg) (mg/m"3) INHALATION INGESTION DERMAL CONTACT INHALATION INGESTION DERMAl FACTOR FACTOR FACTOR INHALAT'O INGESTION CONTACT
ACETONE 0.088 9.2E.05 0.12 !i.9E-07. 3.IE-07 1.IE.05 5.2E.08 2.7E.08 NA NA NA NA NA. NA
iCLOROFORM . 0.016 2.2E.05 0.12, 5.9E..07 3.1E.07 2.6E.06. 9.4E-09 5.0E-09 8.1E-02 6.IE.03 3.IE.02 2.1E.01 5.7E.11 I.5E.10
, TETRACHLOROETHYLE 230 1.1 E.OI 0.12 5.9E.01 3.IE.01 1.3E .02 1.4E.04 7.1E-05 .1.8E-03 5.IE.02 2.5E-01 2.3E-05 6.9E.06 I.8E.05
ITRICHLOROETHYLENE 0.01 2.~E-05 0.12 5.9E-07 3.1E.07 2.9E.06 5.9E-09 3.IE-09 . 1.7E.02 1.1 E-02 5.5E.02 4.9E.08 6.5E.11 . 1.7E-10
CADMIUM 1400 .I.OE-og 0.12 5.9E-07 3.1E.08 1.2E.10 8.2E.04 4.3E-05 6.1 E+OO NA NA 7.3E.10 NA NA
ICHROMIUM 5300 3.8E-09 0.12 5.9E.01 3.1E-08 4.6E.10 3.1E.03 1.6E-04 4.1E+01 NA NA 1.9E.08 NA NA
,COPPER 1200 a.OE.10 0.12 5.9E.07 3.1E.08 1.2E." 7.0E.04 3.7E.05 NA NA NA NA NA NA
iLEAD '1381 2.8E-09 0.12 5.9E-07. 3.1E.08 3.4E-10 8.1E.04 4.3E.05 NA NA NA NA NA NA
NICKEL 760 5.6E-10 0.12 5.9E.07 3.1E-08 6.7E." ~.5E.04 2.4E-05 1.7E+00 NA NA 1.1E.10 NA NA
4.2E-04 NA ...
ZINC 13700 1.0E-08 0.12 5.9E .07 3.IE.08 1.2E.09 8.0E.03 NA NA NA " NA NA
CYANIDE 3100 2.2E-09 0.12 5.9E.07 3.1E.08 2.6E.10 1.8E.03 9.6E:05 NA NA NA NA NA NA
IANTIMONY 39.6 3.6E." 0.12 5.9E.07 3.IE.08 4.3E.12 2.3E.05 1.2E'06 NA NA NA NA NA NA
IARSENIC 4 3.0E.12 0.12 5.9E.07 3.1E-08 3.6E.'J 2.3E.06 1.2E-07 1.5E.01 I.8E.OO 8.8E.00 5.4E.12 ~.IE.06 1.1 E.06
fBIS(2.ETHYLHEXYL)PHT 0.31 2.2E.12 . . 0.12 5.9E.07 3..1E.07 2.6E-13 1.8E-07 9.6E-08 NA I.~E.02 7.0E.02 NA '2.5E-09 6.7E.09
f4.4' DOT 0.058 4.4E.14 0.12 S.9E .07 3.1E-07 5.3E.15 3.4E-08 1.8E-08 3.4E-01 3.4E-01 1.7E+OO 1.8E-15 1.2E.08 3.1E-08
r..4 DOE 0.029 2.2E-14 0.12 5.9E.07 3.IE.07 2.6E.15 1.7E.08 9.0E.09 3.4E.01 3.4E.01 1.7E+00 9.0E.16 5.8E -09 I.5E.08
-
TOTAL 2.3E.05 1.1 E.OS 1.9E .05
UNITS FOR PATH.SPECIFIC INTAKF FACTORS ARE m+jlkg/day FOR INHALATlON'AND kgJkglday FOR INGEST ION AND DERMAL CONTACT
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TES VIII WORK ASSIGNMENT NO. C~
AIRCO PLATlNG COMPANY SITE. BASEUNE RISK ASSESSMENT
CAlCULATION OF AVERAGE DAILY INTAKE FOR FUTURE CHILD RESIDENT (CONTD)
NONCARCINOOENS aROUNDWATE CONCENTR. PATH.SPECIFIC PATH.SPECIFIC AVa. DAIL v AVG. DAILV INHALED ORAL
GRouNDWATER CONCENTR. IN AIR INTAKE FACTO INTAKE FACTOR INTAKE INTAKE REFERENCE REFERENCE RISK FROM RISK FROM
CONTAMINANT (~) (mglmA3) INHALATION INGESTION INHALATION INGESTION DOSE DOSE INHALATION INGESTION
CHLOROFORM 0.022 0.088 1.2E.OJ 1.3E.01 1.1E.04 2.8E.OJ NA 1.0E.02 NA 2.8E.01
1,2.DICHLOROETHYLENE 0.1437 0.57 1.2E.OJ 1.3E.01 6.8E.Q.4 1.8E-02 NA 9.0E.03 NA 2.0E+00
TETRACHLOROETHYLENE 2.6 10.~ 1.2E-OJ 1.3E.01 1.2E.02 3.3E.01 NA 1.0E.02 NA 3.3E+01
TRICHLOROETHVLENE 0.0008 0.039 1.2E.OJ 1.3E.01 ~.7E.05 1.3E.OJ NA 6.0E.03 NA 2.1E-OI
VINYL CHLORIDE 0.0522 0.21 1.2E.OJ 1.3E.01 2.5E.Q.4 6.7E.03 NA NA NA NA
CADMIUM 0.023 NA 1.2E.OJ 1.3E.01 O.OE+oo 2.9E.OJ NA 5.0E.04 NA 5.9E+00
CHROMIUM 0.0551 NA 1.2E.OJ 1.3E.01 O.OE+oo 7.1E.03 5.7E.o7 5.0E.OJ NA 1.4E+00
COPPER 0.049 NA 1.2E.OJ 1.3E.01 O.OE+oo 6.3E.03 NA 3.7E.02 NA 1.7E.01
LEAD 0.0085 . NA 1.2E.OJ 1.3E.01 O.OE+OO 1.1E.03 NA NA NA NA
NICKEL 0.0562 NA 1.2E.OJ 1.3E.01 O.OE+oo 7.2E.03 NA 2.0E.02 NA 3.6E.01
ZINC 0.264 NA 1.2E.OJ 1.3E-01 O.OE.oo 3.6E.02 NA 3.0E-01 NA 12E.01
CYANIDE 0.0075 NA 1.2E.OJ 1.3E.01 O.OE+oo 1I.6E.04 NA 22E.02 NA ~.~E-02
ACETONE 0.0075 0.03 1.2E.OJ 1.3E.01 3.IIE.05 Q.6E.04 NA 1.0E.01 NA 9.6E.OJ
BIS(2.ETHYLHEXVL)PKT 0.0055 NA I.2E.OJ 1.3E.01 O.OE+oo 7.0E-04 NA 3.0E.
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TES VIII WORK ASSIGNMENT NO. C04O&4
AIReo PLATING COMPANY SITE . BASEUNE RISK ASSESSMENT .
CALCULATION OF AVERAGE DAILY INTAKE FOR FUTURE ADULT RESIDENT (COm-D)
NONCARCINOOENS GROUNDWATE CONCENTR. pATH.SPECIFIC PATH.SPECIFIC AVG. DAILY AVG. DAILY INHALED ORAl.
GROUNDWATER CONCENTR. IN AIR INTAKE FACTO INTAKE FACTOR INTAKE INTAKE REF.. REF. RISK FROM RISK FROM
CONTAMINANT (~ . (mglmA3) INHALATION INGESTION INHALATION INGESTION DOSE. DOSE INHALATION INGESTION
CHLOROFORM 0.022 0.088 , 2.9E.03 2.7E.02 2.6E.04 6.0E-04 NA l.oE-02 NA 6.0E.02
1,2.DICHLOROETHYLENE 0.1437 '0.57 2.9E.03 2.7E.02 1.7E.03 3.0E-03 NA II.OE-03 NA 4.4E.ot
T~CHLOROETHYlENE 2.6 10.4 2.9E.03 2.7E.02 3.0E-02 7.1E.02 NA I.oE-02 NA 7.1E+oo
TRICHLOROETHYLENE 0.0098 0.039 2.9E.03 2.7E.02 1.IE-04 ~.7E.04 NA 8.0E-03 NA 4,5E.o2
VINYl CHLORIDE 0.0522 0:21 2.9E.03 2.7E.02 6.1E-04 IAE-03 NA, NA NA NA
CADMIUM 0.023. NA 2:9E.03 2.7E.02 O.OE+OO 8.3E-04 NA 6.0E-04 NA t.3E+OO
CHROMIUM 0.0551 NA 2.9E.03 2.7E.02 O.OE+OO t.SE-03 6.7E'07 6.0E-03 NA 3.0E.01.
COPPER 0.049 NA 2.9E.03 2.7E.02 O.OE+OO I.3E-03 NA 3.7E.02 NA 3.6E.02
LEAD 0.0085 NA 2.9E.03 2.7E.02 O.OE+oo 2.3E-04 NA NA NA NA
NICKEL 0.0562 NA 2.9E.03 2.7E.02 O.OE+OO UE-03 NA . 2.0E-02. NA 7.7E-02
ZINC 0.284 'NA 2.0E.03 2.7E.02 O.OE+OO 7.IIE-03 NA 3.0E.o1 NA 2.6E.02
CYANIDE 0.0075 NA 2.0E.03 2.7E.02 O.OE+oo 2.1E-04 NA UE-02 NA O.3E-03
ACETONE 0.0075 0.03 2.0E.03 2.7E.02 8.7E.05 2.1 E-04 NA 1.0E.o1 NA 2.1E-03
BIS(2.ETHYlHEXYL)PHT 0.0055 NA 2.0E.03 2.7E.02 O.OE+OO UE-04 NA 2.0E-02 NA 7,SE.Q3
1.I.DICHLOROETHENE 0.011 0.044. 2.0E.03 2.7E.02 1.3E-04 3.0E-04 NA II.OE-03 NA 3.3E-02
VANADIUM 0.0047 NA 2.9E.03 2.7E.02 O.OE+OO 1.3E-04 NA . 7.oE-03 NA t.8E.02
TOTAL O.OE+OO 9.4E+oo
CARCINOGENS GROUNDWATE CONCENTR. PATH.SPECIFIC PATH.SPECIFIC ,AVG. DAILY AVG. DAILY INHALED ORAl.
GROUNDWATER CONCENTR. IN AIR INTAKE FACTO ,INTAKE 'FACTOR INTAKE 'NT AKE SLOPE $LOPE RISK FROM RISK FROM
CONTAMINANT l(rroIll (mglmA3) INHALATION INGESTION IN'HAlATION INGESTION FACTOR FACTOR INHALATION INGESTION
CHLOROFORM 0.022 0.088 I.2E.03 1.2E.02 1.1E.04 2.8E-04 8.1E.02 8.1E-03 8.6E.08 1.6E.08
1,2.DICHLOROETHYLENE 0.1437 0.57 t.2E.03 1.2E.02 6.8E-04 1.7E-03 NA NA NA NA
TETRACHLOROETHYlENE 2.6 10.4 1.2E.03 1.2E.02 1.2E.02 3.0E.02 1.8E-03 5.1E-02 2.2E-05 1.6E.03
TRICHLOROETHYLENE 0.0098 0.039 I.2E.03 1.2E.02 4.7E.05 1.1E-04 1.7E-03 1.1E.02 8.0E.08 I.3E-06
VINYl CHLORIDE 0.0522 0.21 I.2E.03 I.2E.02 2,SE-04 8.1E.04 3.0E.o1 1.9E+OO 7.6E-05 I.2E-03
CADMIUM 0.023 NA I.2E.03 1.2E.02 O.OE+OO 2.7E-04 6.1E+OO NA NA NA
CHROMIUM 0.0551 NA I.2E.03 1.2E.02 O.OE+OO 6.4E-04 4.1 E+OI NA NA NA
COPPER . 0.048 AA . 1,2E.03 I.2E.02 O.OE+OO 5.7E~ NA NA NA NA
lEAD 0.0085 NA I.2E.03 I.2E.02 O.OE+OO D.9E-05 NA NA NA NA
NICKEL 0.0562 NA' I.2E.03 1.2E.02 O.OE+OO UE-04 1.7E+OO NA NA NA
ZINC . 0.284 NA I.2E.03 t.2E.02 O.OE+OO 3.3E-03 NA NA NA NA
CYANIDE 0.00711 NA . I.2E.03 I.2E.02 O.OE+OO 8.8E.oII NA NA NA NA
ACETONE' 0.00711 0.03 I.2E.03 1.2E.02 3.8E-05 UE.05 NA NA NA NA
BIS(2.ETHYlHEXYLIPHT 0.0055 NA I.2E.03 1.2E.02 O.OE+OO 8.4E.oII NA. I.4E-02 NA 9.0E.o7
1.I.DICHLOROETHENE 0.011 0.044 1.2E.Q3 1.2E.02 5.3E.05 1.3E-04 . 1.8E.o1 8.OE.o1 9.2E.os 7.7E.05
VANADIUM 0.0047 ' NA 1.2E.Q3 1.2E.02 O.OE+OO UE.oII NA . NA NA NA
I
, TOTAL I.2E.04 " 2.8E.Q3
. .
UNITS FOR PATH.SPECIF'IC INTAKE FACTORS ARE mA3Ikg/day FOR INHALATION AND kglkgJday FOR INGEST ION AND DERMAL CONTACT
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TES VIII WORK ASSIGNMENT NO. C().406-4
AIRCO PLATING COMPANY SITE - BASELINE RISK ASSESSMENT
CAL~LATION OF AVERAGE DAILY INTAKE FOR FUTURE CHILD. RESIDENT
NONCARCINOGENS AMBIENT AIR P.ATH-SPECIFIC ATH-SPECIFIC PATH-SPECIFIC AVG. DAIL Y AVG. DAilY AVO. DAilY INHALED ORAL DERMAL RISK FRO
SURFACE SOIL 95"1'. UCl CONCENTR. INTAKE FACTOR INTAKE FACTO INTAKE FACTOR INTAKE INTAKE ImAKE REF. REF. REF. RISK FROM RISK FROM DERMAl
CONTAMINANT (mjl\
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