United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R04-92/123
September 1992
x°/EPA Superfund
Record of Decision:
Agrico Chemical, FL
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NOTICE
The appendices listed in the index that are not found in this document have been removed at the request of
the issuing agency. They contain material which supplement but adds no further applicable information to
the content of the document All supplemental material is, however, contained in the administrative record
for this site.
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110272-101
'.'.<
REPORT DOCUMENTATION 11. REPORT NO. I ~ 3. Recipient'. AcC8MIon No.
PAGE EPA/ROD/R04-92/123
4. TIt.. and Sub11118 5. Report 0818
SUPERFUND RECORD OF DECISION 09/29/92 .
Agrico Chemical, FL 6.
First Remedial Action - Subsequent to follow
7. Author(.) 8. Perfonnlng Organization RepL No.
8. Perfonnlng Orgalnlzatlon Name and Adell..a 10. ProjectlT..klWork Unit No.
11. Contract(C) or Grant(O) No.
(C)
(0)
12. &PO_Inti Organization Name and Add.... 13. Type of Report 6 Period Cover8d
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
Washingtonr D.C. 20460 14.
15. Suppiemen18ry No...
PB93-964017
16. Abetracl (UmII: 200 wonla)
The 35-acre Agrico Chemical site is a former fertilizer manufacturing facility located
in Pensacola, Escarnbia County, Florida. Land use in the area is mixed residential,
municipal, commercialr and industrial. From 1889 to 1920, sulfuric acid was produced
onsite from pyrite. In 1920, the production of superphosphate fertilizer began. The
source rock used in the process was fluorapatite, which also contained silica and
trace levels of aluminum and uranium. Four unlined ponds used at the site for
wastewater discharge are referred to as PFP I through PFP IV. By early 1957, city
officials shut down a public supply well because analyses indicated declining pH
values and elevated levels of fluoride and sulfate in the ground water. In 1983, EPA
conducted an investigation that indicated that the onsite soil and surface water were
contaminated with elevated levels of fluoride and lead. In January 1987., the state
conducted a ground water assessment at the site that revealed that site contaminants,
primarily fluoride and sulfate, had polluted the ground water. This ROD addresses a
final remedy for contaminated soil and sludge at the site as OU1 to prevent current or
future exposure. Future RODs will address the treatment of contaminated ground water
(See Attached Page)
17. Docu......t Analyala L DMcrlptora
Record of Decision -,Agrico Chemical, FL
First Remedial Action - Subsequent to follow
Contaminated Media: soil, sludge
Key Contaminants: VOCs, other organics (PAHs, pesticides), metals (arsenic, lead),
radioactive materials
II. Identlf"raIOpen-Ended Tarme
c. COSAl1 FlaldJGroup
18. Availability S18tamant 18. Security CI... (This Report) 21. No. 01 Pa,,"
None 62
20. Security Claaa (Thla Page) 22.PrIca
None
A .18 See Insttuctions on Reverse ' ~HM 212 (4-11J
(See NSI-nI )
(Formerty N11S-35)
Department 01 Commerce
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EPA/ROD/R04-92/123
Agrico Chemical, FL
First Remedial Action - Subsequent to follow
Abstract (Continued)
as'OU2 and will include the results of a bayou impacts study being conducted by the PRPs
on the Bayou Texar. The primary contaminants of concern affecting the soil and sludge
are VOCs;' other organics including PAHs and pesticide residues; metals, including arsenic
and lead; and radioactive materials.
The selected remedial action for this site includes excavating an estimated 32,500 cubic
yards of contaminated soil with concentrations above 1,463 mg/kg fluoride from PFP I,
III, and IV, and dewatering the excavated areas; excavating, solidifying, and stabilizi~g
all soil with lead concentrations above 500 mg/kg and arsenic levels above 16 mg/kg from
PFP IV; excavating and stabilizing contaminated sludge from all ponds; consolidating the
excavated soil and sludge from all areas into PFP II; constructing a slurry wall around
PFP II, and covering the area with a RCRA cap; monitoring ground water; and implementing
institutional controls including deed restrictions, and site access restrictions such as
security fencing. The estimated present worth cost for this remedial action is
$10,731,013, which includes a present worth O&M cost of '$384,313.
PERFORMANCE STANDARDS OR GOALS: Chemical-specific soil excavation goals are based on
protection of ground water and include fluoride 1,463 mg/kg. The excavation goals
established for lead and arsenic are based on health-based soil exposure scenarios,
including lead 500 mg/kg and arsenic 16 mg/kg.
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"",
I'
,
RECORD OF DECISION
OPERABLE UNIT 1
AGRICO CHEMICAL NPL SITE
Pensacola, Escambia County, Florida
.~ft~.
t-,
~:7
Prepared By:
Environmental Protection Agency
Region IV
Atlanta, Georgia
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Record of Decision
ODerable Un! t One
Declaration
SITE KAME AND LOCM.'IOR
Agrico Chemical Site
Pensacola, Escambia County, Plorida
STATEMENT OP BASIS AND PURPOSB
This decision document presents the selected remedial action for
the Agrico Chemical Site in Pensacola, Florida, which was chosen
in accordance with CERCLA, as amended by 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 the Aqrico Chemical Site.
The State of Florida, as represented by the Florida Department of
Environmental Regulation (FDER), has been the support agency
during the Remedial Investigation and Feasibility Study process
for the Agrico Chemical Site. In accordance with 40 CFR 300.430,
FDER, as the support agency, has provided input during this
process. Based upon comments received from FDER, it is expected
that concurrence will be forthcoming; however, a formal letter of
concurrence has not yet been received.
ASSESSMENT OP THE SITE
Actual or threatened releases of hazardous
site, if not addressed by implementing the
this Record of Decision (ROD), may present
substantial endangerment to public health,
environment.
substances from
action selected
an imminent and
welfare, or the
this
in
DESCRIPTION OP '1'HB REMEDY
This operable unit is the first action of two planned operable
units for the Agrico Chemical Site. The remedy selected in this
ROD addresses site soils that have been contaminated as a result
of production of fertilizer and sulfuric acid at the Agrico
Chemical Site. This first operable unit addresses the principal
threat at the site by treating the most highly contaminated soils
and waste material. Stabilized waste materials and soils
contaminated at low levels will be consolidated under a RCRA cap
to be constructed on aite.
The major components of the selected remedy includes
.
Excavation and solidification/stabilization of
approximately 32,500 cubic yards of contaminated sludge
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I
I
and soils from site sludge ponds.
Consolidation of all stabilized sludge and soil, in~o
one sludge pond. .
.
.
Construction of a RCRA cap over the sludge pond.
Const:ruction of a slurry wall around the ReRA cap.
.
.
Implementation of institutional controls to include
security fencing, access and deed restrictions.
STATtJ'l'ORY DBTERMIHATIORS
The selected remedy is protective of human health and the
environment, complies with Pederal and state requirements that
are legally applicable or relevant and appropriate to the
remedial action, and is cost-effective. This remedy utilizes
permanent solutions and alternative treatment (or resource
recovery) technologies to the maximum extent practicable and
satisfies the statutory preference for remedies that employ
treatment that reduces toxicity, mobility, or volume as a
principal element. Because this remedy will result in hazardous
substances remaining on-site above health-based levels, the five-
year review will apply to this action.
~1r1~
r Greer C. Tidwell
Regional Administrator
~LrII9J'2
-Date
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TABLI: 01' C())n:ulTS
1.0 SITE LOCATION AND DBSCRIPTION
. . .
. . . . .
. . . . .
2.0
SITE HISTORY AND ENFORCEMENT ACTIVITIBS
. . . . .
. . .
3.0 HIGHLIGHTS. OF COMMUNITY PARTICIPATION
. . .
. . .
. . .
4.0
SCOPB AND ROLB OF OPBRABLE UNIT
. . . . .
. . . .
. . .
5.0 SUMMARY OF SIn CHARACTERISTICS. . . . . . . . . . . .
5.1 GENERAL SITE CHARACTERISTICS. . . . . . . . . . .
5 . 2 GBOLOGY. . . . . . . . . . . . . . . . . . . . . .
5.3 HYDROGBOLOGY
5 . 4 I..AND USB. . . . . . . . . . . . . . . . . . . . .
5.5 RBSULTS OF SITE INVESTIGATION. . . . . . . . . . .
5.5.1 SITE SOIL/SEDIMENT INVESTIGATION. . . . . .
5.5.2 GROUND-WATER INVESTIGATION. . . . . . . . .
SUMMARY OF SITE RISKS. . . . . . . . . . . . . . . . .
6 . 1 SCOPB. . . . . . . . . . . . . . . . . . . . . . .
6.2 CONTAMINANTS OF CONCERN. . . . . . . . . . . . . .
6.3 EXPOSURE ASSBSSMENT ...............
6.4 TOXICITY ASSBSSMENT ...............
6.5 RISK CHARACTERIZATION. . . . . . . . . . . . . .
6.6 ENVIRONMENTAL RISK. . . . . . . . . . . . . . . .
6.0
7.0 DBSCRIPTION OF ALTERNATIVES. . . . . . . . . . . . . .
7 . 1 REMEDIAL ACTION OBJECTIVES. . . . . . . . . . . .
7 . 2 VOLUMES. . . . . . . . . . . . . . . . . . . . . .
7.3 .AR,AR.S. . . . . . . . . . . . . . . . . . . . . . .
7.4 DEVELOPMENT AND SeRBENING OF ALTERNATIVES. . . . .
7.4 . 1 PROCESS. . . . . . . . . . . . . . . . . .
7 . 4 .2 ALTERNATIVE 1 - NO ACTION. . . . . . . . .
7.4.3 ALTERNATIVE 4 -
SOLIDIFICATION/STABILIZATION, RCRA
CAPPING, SLURRY WALL . . . . . . . . . . . .
7.4.4 ALTERNATIVE 7 -
SOLIDIFICATION/STABILIZATION,
CLAY CAPPPING, SLURRY WALL . . . . . . . . .
7.4.5 ALTERNATIVE 8 - SOIL WASHING,
SOLIDIFICATION/STABILIZATION,
CLAY CAPPING, SLURRY WALL . . . . . . . . .
7.4 . 6 ALTERNATIVE 10 - CONTAINMENT
WITH CLAY CAP, SLURRY WALL,
SOLIDIFICATION/STABILIZATION,
AND OFF-SITE DISPOSAL. . . . . . . . . . .
8.0
SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
8 . 1 CRITERIA FOR EVALUATING REMEDIAL ALTERNATIVES. . .
8.2 OVERALL PROTECTION OF HUMAN HEALTH AND THE
ENVIRONMENT. . . . . . . . . . . . . .
. . .
. . .
8.3
COMPLIANCB WITH APPLICABLB OR RELEVANT
AND APPROPRIATE REQUIRBMBNTS . . . . . . . .
. . .
1
1
5
6
6
6
7
7
7
11
11
13
16
16
16
18
19
20
33
34
34
36
36
37
37
38
38
40
41
42
43
44
45
46
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8.4 LONG-TERM BFFBCTIVENESS AND PBRMANENCE . . . . . .
8.5 REDUCTION OF TOXICITY, MOBILITY OR VOLUME
THROUGH TR.BA.'I!-mN'I' . . ~ . . . . . . . . . . . . . .
SHORT-TERM BFFBCTIVENESS ..... . . . . . . . .
IMPLEMBNTABILITY . . . . . . . . . . . . . .
COST . . . . . . . . . .. . . . . . . . . . . . . .
STATE.ACCBPTANCE . . . . . . . . . . . . . . . . .
COMMUNITY ACCBPTANCE . . . .. . . . . . . . . . . .
SBLBCTED RBMBDY . . . . . . . . . . . . . . . . . .
8.6
8.7
8.8
8.8
8.9
9.0
46
46
46
47
47
47
47
48
STATUTORY DBTERMINATIONS . . . . . . . . . . . . . .. 51
10.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT. . 52
10.2 COMPLIANCB WITH APPLICABLB OR ..
RELEVANT AND APPROPRIATE REQUIREMENTS. . . . . . 52
10.2.1 CHEMICAL SPBCIFIC ARARs. . . . . . . . . . 53
10.2.2 ACTION SPBCIFIC ARARs. . . . . ... . . . . 54
10.2.3 LOCATION SPBCIFIC ARARs . . . . . . . .. 54
10.3 COST BFFBCTIVENESS . . . . . . . . . . . . ... . . 54
10.4 UTILIZATION OF PBRMANENT SOLUTIONS AND
ALTERNATIVE TREATMENT TECHNOLOGY OR RESOURCE
RECOVERY TECHNOLOGIBS TO THE MAXIMUM
EXTENT PRACTICABLE. . . . . . . . . . . . . . . .. 55
10.5 PREFBRENCE FOR TR.BA.TMBNT AS A PRINCIPAL BLBMBNT. 55
10.6 DOCUMENTATION OF SIGNIFICANT CHANGBS . . . . . . . 55
10.0
Table 6-1
Table 6-2
Tabl..
Reference Doses (RfDS), Cancer Slope Factors
(CSFs), And BPA Cancer Classification
For Constituents Of Concern. . . . . . . . . . .
Risk Characterization For Direct
Contact With Surficial Soils (CUrrent Use)
. . . .
Table 6-3. Risk Characterization For Direct Contact
With Surficial Soils (CUrrent Use) . . ..
Table 6-4
Table 6-5
Table 6-6
Table 6-7
Table 6-8
Table 6-9
Table 6-10
. . . . .
Risk Characterization por Direct Contact
With Surficial Soils (CUrrent Use) . . . . . . . .
Risk Characterization Por Direct Contact
With Surficial Soils (Future Use) ........
Risk Characterization Por Direct Contact
With Surficial Soils (Future Use) .........
Risk Characterization por Direct Contact
With Surficial Soils (Future Use) .... ~ . ...
Risk Characterization por Direct Contact
With Surficial Soils (Excavation) ........
Risk.Characterization por Direct Contact
With Surficial Soils (Excavation) ........
Risk Characterization Por Direct Contact
With Surficial .Soi18, Baseball Pield
(B;xcavation) ..................
21
24
25
26
27
28
29
30
31
32
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Figure 1-1
Figure 1-2
Figure 5-1
Figure 5-1
Figure 5-2
Figure 5-4
Figure 5-5
Figur..
Regional Area Map and Site Location. . . . . . . . 2
Former Pond Boundaries. . . . . . . . . . . . . . 3
Regional Stratigraphic and Hyrogeologic Column. . 8
Geologic X-Section for the Study Area. . . . . . . 9
Surrounding Land Use. . . . . . . . . . . . . . . 10
Fluoride Concentrations. . . . . . . . . . . .. 14
Vertical Distribution X-Section for Fluoride. . . 15
Appen4ic..
Appendix A Responsiveness Summary
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neci.ion Sn__ry
aecord of neci.ion
Operable hi te eme
Agrico Chemical Site
Pen.acola, rlorida
1.0
SITB LOCATJON AND DBSCRIPTIOR
The Agrico Chemical Site (hereinafter, .the site.) is located in
Pensacola, Bscambia County, Plorida and covers approximately 3S
acres. The site is located at the northwest corner of Pairfield
Drive and Interstate 110 (Pigure 1-1). The site is bounded by
Interstate 110 to the east, Pairfield Drive to the south, the CSX
railroad tracks to the west, and includes an abandoned baseball
field to the north. .
Site topography is flat and ground-surface elevations range fram
about 81 feet to 90 feet National Geodetic Datum (NGVD). Areal.
photographs, field observations, and a topographic map indicate
that surface drainage is currently contained on site. The
concrete foundations of former plant buildings remain on site.
Storage warehouses, in the southern portion of the site, are the
only structures on site. Areas of the site not occupied by the
storage warehouses, old foundations, and the abandoned baseball
field, are open and characterized by tall grass, brush, and
trees. The site is currently owned by Pred L. Vigodsky, Bdwin
Walborsky, and James Lamar Dean, d/b/a MARGOD, a Plorida .
partnership, and P.A. Baird, Jr.
A second baseball field is located north of the abandoned
baseball field. In addition, a fOJ:1l\er excavation, or borrow pit,
is located north of the site. A third baseball. field has been
constructed north of the site by the Potentially Responsible
Parties (PRPs), Conoco Inc. and Preeport MCMoRan, to replace the
abandoned baseball field on-site.
Pour ponds were used for wastewater discharge and designated PPP .
I through PPP IV for the purposes of the RI/PS documents (Pigure
1-2). Aerial photographs taken fram 1940 through 1990 indicate
that the ponds were interconnected throughout different ttme
periods, but the area referenced as PPP II appears to have
received the majority of the sludge. A portion of PPP II is
visible at land surface. In addition, historic aerial
photographs show a drainage ditch through PPP IV to across
Pairfield Drive. A fence has been constructed around the. former
ponds and southern-most baseball field.
2.0. SIn HISTORY AND BNPORCBMBN'l' ACTIVITIBS
Industrial processes at the site began in 1889 by a company that
produced sulfuric acid fram pyrite. The production of sulfuric
acid continued at the plant until approximately 1920. The
sulfuric acid was manufactured in lead pots, in a building
slightly north of PPP IV (Pigure 1-2). Production of nor.mal
. I
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Dw(' DAT[ 04/IIJ/Q7/1Q y, PRJCT NO: $07919
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SCALE A'j tlorm
REGIONAL AREA MAP
AND SITE LOCATION
FEASIBILITY STUDY
AGRICD CHEMICAL SITE:
PENSACOLA. fLl)RIDA
FIGURE
1 - 1
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... .....
" I
, / I J
I II
/ II
I II -
...
I II
i {{
.... i ...
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--- "nIICI..... ID.IOI2R. IIIID .. .
t8ITIIIICIL ....... "WI'-.T1a
"., % nIICI..... .....fIII
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C-II ........, ..,... IIICU. ..-fIII
.. lID' ..... WILL ""'81
=
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-
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200
Former Pond. Boundaries
Phase I Remedial In vestiga tion
. Agrico Chemical Site
Pensacola, Florida
F'IGUR
1-2
-------
superphosphate fertilizer was initiated in 1920. The 80urce rock
used in the process was fluorapatite, which also contained silica
and trace levels of many metals such as aluminum, along with
uranium at 20 to 200 parts per million (ppm) as impurities.
. Superphosphate was produced through the digestion of the source
rock with sulfuric acid and water. The reaction produced
anhydrite and fluoride as byproducts. The anhydrite portion
remained with the product and was sold as part of it, unlike
modern wet process phosphoric acid plants which filter the
anhydrite (phosphogyps~) out and stockpile it on. site.
The historic site files indicate that the plant purchased and
apparently utilized some volume of spent sulfuric acid during
1967 and 1968. Dinitrotoluenes were constituents of this acid in
concentrations which ranged from 5 ppm to 1600 ppm.
There is no way to determine how much spent acid was used over a
given period of time. Calculating probable volumes utilized was
not possible due to the lack of information ~oncerning the amount
of fertilizer produced and the amount of acid used to manufacture
the product. Additional ground-water and soils samples were
analyzed for organics as part of the Phase II RI 8tudy to
investigate the possible moveme~t of dinitrotoluene8 from the
plant, a potential source of which may have been the acid.
By early 1957, Pensacola City officials shut down a public supply
well located downgradient of the site. The City'8 decision to
remove the well from service was based on analY8es indicating
declining pH values and elevated levels of fluoride and sulfate
in the ground water.
BPA conducted a Hazardous Waste Site Investigation in October
1983. The results of the study indicated that the on-site soils
and surface water were contaminated with elevated levels of
fluoride and lead. No attempt was made to install temporary
wells to sample the ground water. However, an effort was made to
locate any private shallow wells in the area; none were located.
The Plorida Department of Bnvironmental Regulation (PDER)
conducted a ground-water assessment at the site in January, 1987.
The study concluded that the.site contaminants, primarily
fluoride and sulfate, had polluted the area ground water. BPA
listed the site on the National Priorities List (NPL) on October
4, 1989.
Conoco Inc. and Preeport MCMoRan Inc. entered into an I
Admdnistrative Order on Consent (AOC) on September 29, ~989.
According to the terms of the AOC, the PRPs agreed to conduct the
source and ground water control RI/FS at the site. The RI field
study was conducted in two (2) phases. The first phase was
conducted in the summer of 1990. Subsequent confirmatory
sampling was necessary in 1991. The second phase RI field study
4
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I I
was conducted in Pebruary, 1992 to more fully define the nature
and extent o"f impacts caused by the site. This ROD addresses ~he
source (soils and sludges) control for the site (Operable Unit
#1). The results of the hydrolbgic RI/PS are detailed in the
1992 Phase I and Phase II RI Reports and the 1992 PS Report.
There is also a bayou impacts study being conducted by the PRPs
on the Bayou Texar. The results of the study will be reported in
an addendum to the RI/FS Reports and will be addressed in a
subsequent Proposed Plan and ROD (Operable Unit #2).
3.0 HIGHLIGHTS OP COMMDHITY PAR~ICIPATIOR
In accordance with public participation requirements of CBRCLA
Sections 113(k) (2) (B) (i-v) and 117, a comprehensive community
relations program was developed and implemented throughout the
remedial process at the Agrico Chemical site. BPA conducted
community interviews in the winter of 1990.
In June 1990, a Remedial Investigation /peasibility Study (RI/PS)
Kick-Off Pact Sheet was prepared and delivered to interested
citizens and local officials included on the site's mailing list.
This fact sheet explained the overall process of Superfund, the
incoming RI/PS at the site, and opportunities for community
involvement. A RI/PS Kick-Off Public Meeting was held on June 5,
1992 with approximately 35 interested citizens of Pensacola,
Plorida to discuss the activities that were to take place as part
of the investigation, and to answer any questions the public had
regarding the upcoming investigation. Television interviews were
conducted with the local ABC affiliate station on two occasions
during the field investigations. BPA also met with members of
the church for whom the new baseball field was built to discuss
potential site risks.
The Public comment period for this ROD was from August 6, 1992 to
September 5, 1992. DUring the comment period, the Administrative
Record was available to the public at both the information
respository maintained at the Pensacola Public Library and at the
BPA Region IV Docket Room in Atlanta, Georgia. A Proposed Plan
public meeting was held on Thursday, August 13, 1992. At the
meeting, representatives from BPA presented BPA's preferred
alternative for source cleanup of the site and answered any
questions the public had regarding the preferred alternative.
Approximately 50 interested parties attended this meeting. A
response to the comments received for the.Agrico Chemical site
during the public comment period and at the Proposed Plan" public
meeting is included in the Responsiveness Summary, whiqh is part
of this Record of Decision. This decision document presents the
selected source control remedial action for the Agrico Chemical
site in Pensacola, Plorida, chosen in accordance with CBRCLA, as
amended by SARA, and, to the extent practicable, the National
Contingency Plan. The decision for this site is based on the
Administrative Record for the site.
5
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4.0
SCOPB AND ROLB OP OPBRABLB URIT
As with many Superfund sites, the problems at the Agrico Chemical
site are complex. As a result, EPA organized the remedy into two
operable units (OUs). These are:
.
OU One:. Contamination of the soils.
.
OU Two:
Contamination of the ground water.
This ROD will address EPA's selected remedy for OU One,
contamination of the on-site soils and sludges. Potential
ingestion of soils and sludges poses the principal threat at the
site because the EPA's acceptable risk range is exceeded. In
addition, contaminant concentrations in soils and sludges are
greater than those established by the Agency and the State of
Florida as protective of ground water. The purpose of this
response is to prevent current or future exposure to the
contaminated soils and sludges on the site. In addition, this
response will eliminate further impacts to the ground water.
This first operable unit will be the first response action for
the site. The remedial action for OU Two, treatment of
contaminated ground water, will be selected in a subsequent ROD.
5.0
StJMMAIty OP SID t"1fUAC"l'BRISTICS
The purpose of this section is to discuss the general site
physical characteristics and to discuss the results of the source
characterization Remedial Investigation. The issue of ground-
water contamination is addressed in the Phase I Remedial
Investigation Report, Geraghty & Miller, Inc., March 1992, and
the Phase II Remedial Investigation Report, Geraghty & Miller,
Inc., August 1992. A short swmnary of the extent of ground-water
contamination is discussed in this section. However, a selected
remedy for ground-water contamination is outside the scope of
this document. EPA's selected remedy for ground-water
contamination will be addressed in a subsequent ROD.
5.1
GBNBRAL SID t'"RJ..RAC"l'BRISTICS
Climate in the Pensacola area is characterized by mild winters
and relatively long, humid, warm summers. The average annual
rainfall is 62 inches. Pensacola is located in the coastal
lowlands, a subdivision of the Coastal Plain province. The
coastal lowlands are relatively level with an elevation of 100
feet NGVD or less. The most significant topographic features are
step-like Pleistocene marine terraces that generally p~rallel the
coast. The Agrico Chemical site is within a plain of a
Pleistocene terrace and, as a result, is relatively flat. Site
elevation varies from about 81 feet to 90 feet NGVD.
6
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5.2
GEOLOGY
The uppermost sediments in the Pe~sacola area are marine ~erraces
and beach scarps, and the Citronelle Formation. The marine'
terraces and beach scarps are composed mainly of quartz sand but
contain some clay, silt, gravel, and iron oxide-cemented
sandstone, locally referred to as hardpan. The sediments were
deposited in ~ine, deltaic, and fluvial environments and are
Middle Oligocene to Pleistocene in age (Figure 5-1).
The site geology's predcminant lithologies are sands, clayey
sands, and sandy clays. A geologic cross section showing the
variation in lithology over the study area was constructed fram
monitoring wells AC-lD, AC-2D, AC-3D, AC-l0D, and AC-llD (Pigure
5-2). A shallow layer of sandy clay, present over much of the
area, is encountered at approximately 10 feet below land surface
(bls) in the vicinity of the site and is about 30 feet thick.
The sandy clay layer tends to thicken towards the south of the
study area where it is found at land surface. Descriptions of
soil samples taken for the RI indicate that soils on the site
could be classified as Lake 1 and and Bustis. These soils.are
characterized by rapid external and internal drainage, small
inclusions of organic matter, low fertility, and susceptibility
to erosion in sloping areas. .
5.3
IIYDROGBOLOQY
The upper-most water bearing unit in Pensacola is the.sand-and-
gravel aquifer. The upper limit of the aquifer coincides with
the surface of the water table and the lower limit of the aquifer
coincides with the top of the Pensacola Clay. The Pensacola
Clay, which is vertically persistent. in the Pensacola area, acts
as a confining unit between the sand-and-gravel aquifer and the
upper portion of the Floridan Aquifer. According to lithologic
logs from wells installed for the Phase I and Phase II RI and
previous studies, the sand-and-gravel aquifer is approximately
270 feet in thickness and extends to that depth below land
surface (bls) in the vicinity of the site. The sand-and-gravel
'aquifer is characterized by various permeability zones.
Generally, two permeability zones are identified for purposes of
defining ground water flow direction. The potentiometric surface
contour maps for both shallo~ and deep zones of the aquiter show
that ground-water flow direction is essentially east-southeast in
the vicinity of the Agrico site, but becomes easterly as it
approaches Bayou Texar~
5.4
LAND USB
f
The land use surrounding the site within a l-mile radius consists
ot residential, municipal, commercial, and industrial zoned areas
(Figure 5-3). Immediately to the north and west of the site is
an industrial zoned area. The Bscambia Wood Treating
7
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EJ
SANDY CLAY
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Area
FIGURE
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FIGURE
SURROUNDING LAND USE
5-3
o -
-
- 2000
AGRICO CHEMICAL SITE
PENSACOLA, FLORIDA
-------
Company site is located in this area and is the current subject
of a removal. BPA is currently excavating contaminated soil from
the site and stockpiling it on site as a Superfund removal
action. .
5.5 RESULTS OP SID INVBSTIGATIOlf
The Agrico Chemical site RI was conducted in two phases. Pield
work for the Phase I RI was initiated in mid-1990. Confirmatory
sampling was required in April 1991, and again in November, 1991.
Field investigations for the Phase II RI were conducted in
February, 1992.
Constituents to be addressed during the Remedial Investigations
were identified by locating and sampling the primary areas of .
waste deposition. Available records indicate that the four
impoundment ponds had received industrial wastewater and sludges
(Figure 1-2). Soil borings were used to investigate the
horizontal and vertical extent of waste deposition within the
four sludge ponds. Based on historical areal photographs,
isolated areas off-site were also targeted for. sampling and
analyses. Samples of soil and sludge were analyzed for the
TAL/TeL parameters to provide a characterization of the
contamination. Blevated levels of radionuclide activity, if
present at a fertilizer production plant, are generally
associated with the gypsum stacks. However, at the Agrico site
the anhydrite (gypsum) portion remained with the product and was
sold as part of the final product. Nevertheless, BPA required
that targeted areas on site were to be analyzed for
radionuclides.
An existing monitoring well network, established specifically for
a previous PDER investigation of the site, was supplemented by
newly installed and other already existing monitoring wells.
During the first phase of the RI, samples of ground water were
analyzed for the TAL/TeL parameters. Ground-water sampling
efforts during the second phase RI focused on site specific
inorganic constituents, organic constituents, and radionuclides.
It should be remembered that the ground-water contamination
investigation is not complete at this time. The ground-water
remediation selection is not an objective of this ROD.
5.5.1
SITH SOIL/sBD~ INVBSTIGATIOlf .
Blevated fluoride concentrations were noted at most of the Agrico
targeted and random soil and sludge locations. Pluoride.
concentrations in surficial soils ranged fram the labor. tory
detection limit of 150 me/kg to 530,000 me/kg in a sample
obtained fram the on-site abandoned baseball field. Blevated
levels of fluoride concentrations were detected within the
boundaries of the sludge ponds PFP I, PFP II, and PFP III.
However, the sampling results of the main or east impounom~nt
11
-------
pond, PFP II, clearly indicate that the most extensive
contamination of fluoride is within its boundaries. Fluori~e
concentrations in excess of 2,500 mg/kg were noted in a soil
boring collected at a depth of 25 feet below land surface (bls)
within this sludge pond. The fluoride concentrations detected in
soils off site were slightly above the detection limit.
Arsenic concentrations were detected either at or slightly above
the detection limit in all areas of the site, except for two
locations. A sample obtained fram the PFP IV pond yielded an
arsenic concentration level of 56 mg/kg. An arsenic detection
level of 58 mg/kg was obtained fram the PFP II pond.
Blevated lead concentrations were detected in the area of PFP IV
impoundment pond. A surficial soil sample collected fram PFP IV
yielded a lead concentration of 46,000 mg/kg. The lead
contamination is confined to surficial soils. Soil borings at
depths of 10 feet bls in the PFP IV pond yield lead
concentrations below 100 mg/kg. Lead fram the site is not
impacting the ground water. Site records indicate that sulfuric
acid was manufactured in lead chambers located in this area.
Blevated sulfate concentrations were noted in samples obtained
fram the PFP II sludge pond. The concentrations of
nitrate/nitrite fram the PFP I, II, and III sludge ponds range
fram below laboratory detection to 12 mg/kg. Blevated levels of
aluminum (44,000 mg/kg) were detected in samples collected fram
the PFP III sludge pond.
The presence of organochlorine pesticides is limited. The
compound dieldrin was detected in two locations at a maximum
detection of 2.4 ug/kg. 4,4-DDT was noted in two locations at
levels slightly above the detection level.
The volatile organic compounds, acetone and methylene chloride,
were detected at elevated levels in numerous soil samples and
sample blanks. However, sample results for these contaminants did
not exceed ten times the maximum amount detected in any blank.
According to the Functional Guidelines for Organics (BPA 1988e),
sample results not exceeding ten times the maximum amount
detected in any blank should be considered a laboratory artifact.
Methylene chloride is used as a solvent and carrier fluid in the
gas chromatography procedure and is commonly detected by this
method. The Acetone (2-proponone) detected in the samples is
likely the result of residual laboratory grade isopropyl alcohol
(2-propanol) used in the field decontamination procedures between
sample collections. .
Blevated semi~volatile organic compound levels were detected in
the area of the PFP IV impoundment pond. Di-n-butyl phtalate and
Di-n-octyl phthalate were detected in numerous soil samples and
sample blanks. Using the above BPA guidelines, it appears these
12
-------
I'
contaminants are field artifacts. The presence of the two
phthalate compounds is the result of contamination fram gaskets
used in thenanalytical instruments,which is detectable ,at -:rrery
low semi-volatile organic concentrations. ','.
Samples and analyses of radionuclides, gross alpha, gross beta,
radium 226, and uranium 238 were collected from the sludge ponds
PPP I, PPP II, and PPP III. Also, other alpha-emitters fram the
»2thorium and ZUuranium decay series are likely present. The
highest radionuclide activity was a reading for uranium 238 of
8.0 picocuries per gram (pCi/gm). The detected level' for this
radionuclide is lower than regional background levels of 20 to
200 parts per million.
In conclusion, the contaminants of concern in the soils and
sludges at the Agrico site are primarily fluoride, arsenic and
lead. ' The highest contamination of fluoride is found in the
areas of PPP II, PFP III, and PPP I. The lead and arsenic
contamination is generally confined to the area of PPP rY.
5.5.2
GROUND-WATER INVBSTIQATIOII
To' further define the extent of ground-water contamination
associated with the Agrico Chemical site, six (6) two-well
clusters, screened in the shallow and deep zones of the sand-and-
gravel aquifer, were installed during the two phased RI study.
In addition, three (3) new shallow wells and three (3) new deep
wells were added to the existing well network.
The discharge of wastewater has generated a ground-water plume of
contaminants that is approximately 7,000 feet long and 1,300 feet
wide. The monitoring well network indicates that the plume of
inorganic constituents has migrated to the Bayou Texar within the
northern portion of the study area (Figure 5-4). The most highly
concentrated area of the plume is in the lower portion of the
sand-and-gravel aquifer, approximately 2,000 feet downgradient of
the site (Figure 5-5). ' ,
During phase II of the RI study, samples fram 34 existing and
recently installed monitoring wells were collected and analyzed
for inorganic constituents related to plant processes. A plume
of mainly semivolatile organic compounds is present in the deep
zone of the aquifer in the northern portion of the study area.
The source of the organic plume appears to be the Bscambia
Treating Company site, a fo~er wood treatment facility located
approximately 2,500 feet hydraulically upgradient from the Agrico
site. I
13
-------
NORTH
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)1
2000
Fluoride Con centra tions
in the Deep Zone
Phase II Remedial Investigation
Agrico Chemical Site
Pensacola, Florida
FlC JRE
5-4
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WA TER LEVEL £lEVA TlON
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rWORIO£ CONC£NTRA TlON VERTICAL DISTRIBUTION (mg/l)
FlUORIDE CONCENtRATION (mg/l)
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-.------
Vertical Distribution Cross Section for Fluoride
(F'ebruBry 1992)-
Plwse II Uemedial Investigation
Agrico ChenlicBI Site'
Pensacola. Flo,.;da
..-.-.-
100
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FIGURE
5-5
-------
]1
,
A study of the ground-water impacts to the bayou is currently
being conducted. After this study is complete, BPA will .elect a
remedy for the second operable unit, .contamination of the ground.
water.
6.0
6.1
S1JMKARY OF SID RISES
SeOPB
The baseline risk assessment provides the basis for taking action
and indicates the exposure pathway. 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. Thi.
section of the ROD reports the result. of the baseline ri.k
assessment conducted for this .it..
A baseline Risk Assessment was conducted by BPA as part of the RI
to estimate the health or environmental problems that could
result if the Agrico site was not remediated. Result. are
contained in the Pinal Risk Assessment Report. A Baseline Risk
Assessment represents an evaluation of the .No Action.
alternative, in that it identifies the risk present if no
remedial action is taken. The assessment consider. environmental
media and exposure pathways that could result in unacceptable
levels of exposure now or in the foreseeable future. Data
collected and analyzed during the RI provided the basi. for the
risk evaluation. The risk assessment process can be divided into
four components: contaminant identification, exposure assessment,
toxicity assessment, and risk characterization. The ri.k
assessment for source control is summarized in this doucment.
However, because the risk associated with ground-water
contamination will be addressed in a subsequent ROD, the ri.k
assessment for ground water is not summarized here.
6.2
CONTAMINANTS OF COHCBRlI
Compiled aerial photos (ranging in age from 1940 to 1990)
illustrate that water from the facility operations ponded in four
general areas. These areas are shown on Pigure 1-2 and will be
referred to in this section as PPP I, PPP II, PPP III, and PPP
IV. Other site areas referred to in the following risk sections
are the on-site baseball field and the former drainage ditch
associated with PPP IV. The four ponds are now devoid of any
surface water. Surface drainage is currently contained on .ite
as a result of natural topography and berms associated with road
construction. Por the purpose8 of this ROD, soi18 are the media
of potential concern at the site. Lands surrounding t~ site are
zoned industrial to the north, commercial/office/residential to
the west and south, and medium-to-low density residential further
south and to the east. There i8 no residential development in
the immediate vicinity. Therefore, it is unlikely that the
future use of the property would include residential development.
16
-------
Several factors are considered in determining whether a
constituentndetected in soils is i~cluded or dropped from.
consideration as a constituent of concern. Constituents not'
detected at concentrations above the detection limit are not
retained for consideration. Constituents detected only once in a
particular media at a concentration less than twice the detection
limit are excluded from the above list. Constituents detected in
soils at concentrations below background concentrations for soils
in the vicinity of Pensacola are eliminated from consideration as
contaminants of concern. Constituents that are essential human
, nutrients and toxic only at very high doses (i.e., much higher
than those that could be associated with contact at the site) are
eliminated from the quantitative risk assessment. Examples of
such constituents are iron, magnesium, calcium, potassium, and
sodium.
Thirty-eight (38) chemical contaminants were found in the soils
and/or sediments at the Agrico Chemical site. Based on the
chemical screening guidelines published in the U.S. BPA Human
Health Evaluation Manual (HHBM), 1989, twenty-one (21) chemicals
of potential concern were retained for the detailed health risk
assessment. Those 21 chemicals, are:
IDo~ganic Con.tituenta
o
o
o
o
o
Arsenic
Aluminum
Pluoride
Nitrate
Lead
Volatile Organic CampoUDd8
o
o
Acetone
Methylene chloride
Semi-Volatile Organic CompoUDd8
o
o
o
carcinogenic Polycylcic Aromatic Hydrocarbons
total Polycyclic Aromatic Hydrocarbons
Di - n-butylphthalate.
P..ticide.
o
o
o
o
o
o
o
o
4,4' -DDT
Dieldrin
2,4-Dinitrotoluene
2,6-Dinitrotoluene
Bndosulfan I
Aldrin
beta-BRC
4,4-DDB
17
-------
RadioDuclide.
o
o
o
Radium-226
Radium-228
Uranium-238
6.3
BXPOSURB ASSBSSMBHT
Two timeframes are considered in the baseline ri8k assessment:
(1) the current risk, or the risk fram the .ite as it exist.
today, and (2) the future risk from the site assuming no remedial
actions are taken. The current risk assessment examine. the
risks for all pathways which analytical data indicate. that
constituents have already reached a point of exp08ure.
Two human receptor populations are evaluated in the current and
future use scenario - resident and excavation worker. Por the
purpose of determining future risks associated with constituents
detected in surficial and subsurface soils, it is assumed that
the site is developed into a residential area. Exposure via
direct dermal contact and ingestion is assumed for hypothetical
adult and child residents. This i8 a conservative approach a.
residential use of the 8ite is unlikely. Risks a880ciated with
direct contact with surficial and subsurface 80ils will also be
determined for an excavation worker, assuming future development
of the 8ite.
Current public exposure to surficial 80i18 and 8ludges in the
vicinity of fo~er pond areas PPP I, PPP II, PPP III, PPP rv, the
baseball field, and the fo~er drainage ditch is assessed in the
RIfFS Ri8k Assessment. Routes of exposure evaluated include
ingestion, dermal contact, and inhalation of 8uspended
particulates. Low concentrations of VOCs (acetone and methylene
. chloride) were detected in a minimal number of 80il samples.
Therefore, vapor inhalation is not expected to be a significant
exposure pathway for soils and not evaluated herein.
There is no current human exposure to subsurface soils. Assuming
the property is developed into a residential area in the future,
there is the potential for adult and child residents and
excavation workers to be exposed to constituents in 8urficial and
subsurface soils. Subsurface 80ils could be brought to the
surface during excavation for foundations or basements. .
. I
Representative exposure point concentrations (EPC) are taken as
the lesser of the 95 percent upper confidence limit (UCL) on the
mean of the lognormal distribution or the maximum detected
concentration of available samples by media and area.
Constituent concentrations are assumed to remain constant; thus,
18
-------
current and future exposure point concentrations are the same.
Concentratio.ns in dust also are assumed to equal concentrations
in soil for a given area. Por current public exposure, oBly .
surficial soil samples are considered. Hypothetical future
residents and excavation workers are assumed to be exposed to
constituents in surficial and subsurface soils.
por the resident adult scenario for exposure to soils, the period
of exposure is 100 days/year for 30 years. Assuming hands, face,
neck, and forearms (skin eurface area of 2,940 ~) are exposed
to soil, 1.45 mg/~ of soil adheres to exposed skin. Por the.
resident child scenario, the period is 100 days/year for 6 years.
Assuming skin surface area of 2,758 ~exposed to soil, 1.45
mg/~ of soil adheres to exposed skin. The same general.
exposure assumptions used to calculate current exposure to 80ils
also apply for future exposure. Por future exposure, an
additional receptor, a site excavation worker, is a180 .
considered. Por the excavation worker scenario for exposure to
soils, the period of exposure is 8 hours/day for a 90-day
exposure. Using the skin surface area of 2,940 car exposure to
soil, 1.45 mg/~ of soil adheres to exposed skin.
Ingestion, inhalation, external exposure, and ingestion of
vegetables grown in affected soils are the exposure pathways
evaluated for the radionuclides of concern, radium 226 and
uranium-238, at the site. Dermal uptake is not evaluated because
this route of uptake is generally not an important route of
uptake for radionuclides.
6.4
TOXICITY ASSBSSMBRT
Slope factors (SPs) have been developed by BPA's carcinogenic
Assessment Group for estimating excess lifetime cancer risks
associated with exposure to potentially carcinogenic
contaminant(s) of concern. SPs, which are expressed in units of
(mglkg-day) "1, are multiplied by the estimated intake of a
potential carcinogen, in mg/kg/day, to provide an upper-bound
estimate of the excess lifetime cancer risk associated with
exposure at that intake level. The term .upper bound. reflects
the conservative estimate of the excess lifetime cancer risk
associated with exposure at that intake level. Use of this
approach makes underestimation of the actual cancer risk highly
unlikely. Slope factors are derived from the results of human
epidemiological studies or chronic animal bioassays to which
anima1-to-human extrapolation and uncertainty factors hav~ been
applied (e.g., to account for the use of animal data to predict
effects on hn~na). ,
Reference doses (RfDs) have been developed by BPA for indicating
the potential for adverse health effects from exposure to
contaminant(s) of concern exhibiting noncarcinogenic effects.
19
-------
RfDs, which are expressed in units of mg/kg-day, are estimates of
lifetime daily exposure levels for humans, including sensitive
individuals. Bstimated intakes of contaminant(s) of concern
ingested fram contaminated drinking Water can be compared t~ the'
RfD. RfDs are derived fram 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). Taqle 6-1 provides Reference Doses (RfDs), Cancer
Slope Factor8 (CSFs) and BPA's Cancer Classification for
constituents of concern.
'.5
RISE ~~CTBRIZATIOR
Por carcinogens, risks are estimated as the incremental
probability of an individual developing cancer over a life-time
a8 a result of exposure to the carcinogen. Exce88 life-time
cancer risk is calculated fram the following equation:
Ri8k - CDI X SP
where:
risk - a unitless probability (e.g., 2 X 10~) of an individual
developing cancer;
CDI - chronic daily intake averaged over 70 years (mg/kg-day);
and SF - slope-factor, expressed as (mg/kg-day)~
These risks are probabilities that 'are generally expres8ed in
8cientific notation (e.g., 1~04 or 1~). An excess lifetime
cancer risk of 1x104 indicate8 that, as a reasonable mLyi~
estimate, an individual has 1 in 1,000,000 additional chance of
developing cancer a8 a result of site-related exposure to a
carcinogen over a 70-year lifetime under the specific expo8ure
conditions at a site.
The potential for noncarcinogenic effects is evaluated by
comparing an exposure level over a 8pecified t~e period (e.g.,
lifetime) with a reference dose derived for a similar exposure
period. The ratio of exposure to toxicity i8 called a hazard
quotient (HQ). By adding the HQs for all contaminants(s) of
concern that affects the same target organ (e.g., liver) within a
medium or across all media to which a given population may
reasonably be exposed, the Hazard Index (HI) can be generated.
The HQ is calculated as follows:
Non-cancer HQ - CDI/Rfd
20
-------
Table 6-1
aeference oo.e. (RfDS), CaDcer Slope Factor. (CS..), and BPA Cancer Cla..ificatioD
for Con.tituent. of ConcerD, Agrico Chemical Site
afD (ag/kg/day)
CS. (8IJ/kg/day)"
BPA Cancer
Cla..ificatioD
.
Con.tituent
Oral
Inhalation
Oral
Inhalation
Arsenic 3x10'" 1m 1.75xlOo 5. OxlO. A
Pluoride 6x10.2 1m NA NA D
Nitrate 1.6x10o 1m 1m 1m D
Organic.
voc.
Acetone 1x10'. 1m NA NA D
Methylene chloride 6x10.2 8. 6x10-. 7.5xlO'" 1.6xlO'" 82
Sead -VOC.
Di-n-butylphthalate 1xlO'. . 1m NA NA
2,4-Dinitrotoluene 1m 1m 6 . 8x10.1 1m 82
2,6-Dinitrotoluene 1m . 1m 6. 8x10'. 1m 82
cPAHs 4X10'" 1m . 5 . 8x10' 6.1x10' 82
tPAHs 4x10'" 1m NA NA D
Pe.ticide.
I Beta - 8RC
1m
1m
1. 8x10o
1.8x10'
C
I
21
-------
(Table 6-1 continued)
4,4-DDT 5x10~ ND 3. 4x10.1 3. 4x10-1 82
Dieldrin 5x10..s ND 1.6x10. 1.6x101 82
Bndosulfan I 5x10..s ND NA NA D
NA
ND
A
81 or
82
C
D
Not applicable
No data
Itnown Human Carcinogen
Probable Human Carcinogen, where 81 indicates that limited data is available.
82 indicates sufficient evidence in animals and inadequate or no evidence in
humans.
Possible Human Carcinogen
Not a Carcinogen
22
-------
where:
CDI - Chronic Daily Intake
Rfd - reference does; and
CDI and RfD are-expressed in the same units and represent the
same exposure period (i.e., chronic, subchronic, short-te~).
Risk characterization for current and future direct contact with
soi18 for resident adult, child, and excavation worker is
summarized in Tables 6-2 through 6-10. Excess lifetime cancer
risk associated with current ingestion, inhalation, and external
exposure to radionuclides ranged fram 1x10~ in the PPP I area to
6x10~ in the PPP II area. As is evident, these risks are lower
that the BPA's target clean-up risk range for Superfund sites
(10" to 10-4).
The cPAHs contribute to the cancer risk for current exposure at
the PFP IV area, where the cancer risk associated with cPABS is
4.1x10~. For the current residential scenario, Dieldrin
contributes to the excess cancer risk for the for.mer ditCh
location at a risk number of 1.Sx10~. Dieldrenalso poses a non-
cancer risk at this location with a hazard index of 1.8. .
Deter.mination of current non-cancer effects, expressed as hazard.
indices, range from 0.2 to S for an adult and from 0.4 to 40 for
a child. Fluoride contributes most significantly to the hazard
indices. The highest hazard indices are for current exposure to .
soils at the b.seball field.
BPA has identified a blood lead level of 10ug/dL as a
concentration of potential concern for health effects in children
that warrants avoidance. The results of the LEADS model run
using the Agrico site data indicate that 100 percent of. the
hypothetical child residents exposed to soils at PPP IV would
have blood lead. levels above 10 ug/dL. .
Hypothetical future risks to adults and children residents and to
excavation workers exposed to constituents in surficial and
subsurface soils via direct contact are found on Tables 6-5
through 6-10. Hazard indices range from under 1.0 for an adult
to 100 for a child. The significant hazard index of 100 is
associated with the risk from Fluoride on the baseball field.
Cancer effects from dieldrin are evident in the area of the
for.mer drainage ditch with a risk of 5.1x10~. In this tame area,
. non-cancer effects for dieldrin yield a hazard index 0 6.4.
Under the future use scenario, excess lifetime cancer risk from
cPAHs located in PFP IV is 1.5x104.
23
-------
Table 6-2
R.ISE CEARAC'l'BR.IZATIOH .OR. DIRECT
COH'1'AC'l' WITS SUUICIAL SOILS (COR.RJD1T US.)
PI'P I (mg/kg)
Cancer Bffects
~
Calculated Risks
Adult Child
Arsenic
cPAHs
Dieldrin
5.0 x 10"
4.3 x 10"
1 . 2 x 10"
6.0 x 10..s.
12
7.8
0.2
Non-Cancer Bffects
Arsenic
Fluoride
Nitrate
tPAH8
4,4' -DDT
Dieldrin
2.2 x 10~
1.0 X 10.1
7.0 X 10''7
8.9 x 1001
3.7 x 1001
3.6 x 10~
0.2
P.P II (mg/kg)
12
11,000
2
16
0.3
0.2
7.4 x 10"
4.2 x 10"
1 . 1 x 1 ~.s
6.0 x 10
1.6 X 10.1
7.5 X 10-1
5.1 x 10"
4.4 x 10~
1.6 x 10~
1 . 5 x 10.1
1.0
BEe
Calculated Risks
Adult Child
Cancer Bffects
Arsenic
2,4-Dinitrotoluene
2,6-Dinitrotoluene
cPAHs
4.6 x 10"
7.1 x 10"
2.5 x 10"
2.6 x 10"
4.0 x 10"
11
11
3.9
4.7
Non-Cancer Bffects
Arsenic
Fluoride
Nitrate
Acetone
tPAHs
Bndosulfan I
2.0 x 10~
2.9 x 10°
6 . 6 x 10.'7
3.9 x 10~
6.7 X 10'"
1.2 x 1001
3.0
11
310,000
1.9
8.6
12
0.024
6.8 x 10"
7.0 x 10"
. 2.5 x 10"
2.6 x 10"
4.0 x 10"
1.5 X 10-1
2.1 x 10+1
4.9 x 10"
1.8 x 1001
3.3 x 10~
5.9 x 1001
20.0
----------------------------------------------------------------.
BPC -
cPAHs -
tPAHs -
a -
Exposure Point Concentrationa
sum of carcinogenic Polycylcic Aromatic Hydrocarbons
total Polycyclic Aromatic Hydrocarbons i
Cummulative risks may be slightly higher for some
scenarios than additive risks on this summary page due to
the low level risk contributions from other contaminants.
24
-------
Table 6-3
RISE CB:A.RAC'l'BRIZATIOR I'OR DIRBC'l'
COR'l'ACT WITH SOU'ICIAL 'SOILS (COUD1T USB)
PI'P III (mg/kg)
Cancer Effects
Arsenic
cPABs
Non-Cancer Effects
Arsenic
Fluoride
Nitrate
Acetone
Methylene Chloride
Di-n-butylphthalate
tPABs
Aldrin
, 4,4' -DDB
Dieldrin
Bndosulfan I
Cancer Effects
Arsenic
cPABs
Aldrin
Non-Cancer Effects
Arsenic
Fluoride
Nitrate
Acetone
tPAHs
Aldrin
Endosulfan I
Heptachlor
lEe
Calculated Risks
Adult Child
4.6
4.17
1.9 x 10~
2.3 x 10-5
3.0 x 10-5
2.8 x 10~
2.3 x 10-5
3.0 x 10-5
6.3 X 104
2.7 X 10-1
, 1.4 x 10-5
1.9 x 10'"
9.2 x 10~
3.5 x 10-5
2.5 x 10011
5.1 x 10"
3.1 x 10'"
5.3 x 10"
1.0 x 10-5
0.4
ec
Calculated Risks
Adult Child
25
3.5 x 10-5
4.1 x 10'"
2.1 X 10-4
5.0 x 10'"
7.7 X 10-1
5.5 X 104
4.9 X 10-4
2.0 x 10011
5.2' X 10-1
4.8 X 104
i.3 x 10011
3.3 x 10"
1.0
cPABs - sum of carcinogenic polycylcic Aromatic Hydrocarbons
tPAHs - total Polycyclic Aromatic Hydrocarbons
8.6 x 10"
3.6 X 104
2.0 x 10~
4.3 x 10-5
2.1 x 10~
7.0 x 10~
5.2 x 10"
1.2 x 10'"
7.0 x 10-5
1.2 x 10"
2.1 x 10'"
0.05
PFP IV (mg/kg)
4.6
3,900
5.6
0.94
0.027
0.34
9.3
0.005
0.0056
0.0069
0.0041
56
76
0.047
2 .3 x 10-5
4.2 x 10'"
2.4 x 10~
4.0 x 10'"
56
810
1.9
96
189
0.047
0.051
0.043
1.0 X 10-1
7.5 x 10"
6 . 6 X 10-1
4.4 x 10"
1. 0 X 10-1
1.1 X 104
2.6 x 10"
7.7 x 10'"
0.2
-------
Table 6-4
RISI: ('H~JlIZATIOH POR DIUcr
COH'l'ACT WITH StJU'ICUL SOILS (CtJJWD1'r US.)
Ba.eball l'ie14 (mg/kg)
He
Calculated Risks
Adult Child
Cancer Effects
Arsenic
5.8
2.4 X 104
2.0 X 104
3.6 X 104
4.0 X 104
Non-Cancer Effects
Ar.enic
Fluoride
1.1 X 104
L.1
5.0
Pormer Drainage Ditch (mg/kg).
5.8
530,000
7.9 X 104
3 .6 X 10+1
36.0
He
Calculated Risks
Adult Child
Cancer Effects
cPAB8
Dieldrin
2.1
2.4
1.1 x 10'"
1.5 x 10~
2.0 x 10~
1.1 x 10'"
1. 3 x 1 O~
1.0 x 10~
Non-Cancer Effects
Methylene Chloride
Di-n-butylphthalate
tPAB8
Dieldrin
0.01
4.8
3.9
2.4
7 . 6 x 10.7
9.9 x 10'"
2.2 x 10~
4.3 X 10-1
0.4
3.4 X 104
4.9 x 10~
1.1 X 10-2
1. B x 10°
2.0
----------------------------------------------------------------
BPC - Exposure Point Concentrations
cPAHs - sum of carcinogenic Polycylcic Aromatic Hydrocarbons
tPAHs - total Polycyclic Aromatic Eydrocarbons
26
-------
'1'aJ)le ,- 5
_ISI: C'HUAC'l'BJlIZA'1'IOR .0- J)IUCT
.COH'l'AC'r WIft StJUICIAL SOILS (,uTud VS.)
." %
~ancer Bffects
Arsenic
cPAHs
Dieldrin
Non-Cancer Bffects
Arsenic
Pluoride
Nitrate
Di-n-butylphthalate
tPAHs
4,4' -DDT
Dieldrin
Cancer Bffects
Arsenic
2,4-Dinitrotoluene
2,6-Dinitrotoluene
cPAHs
'Non-Cancer Bffects
Arsenic
Pluoride
Nitrate
Acetone
Di-n-butylphthalate
tPAHs
Bndosulfan I
~
12
7.8
0.2
12
4,500
2
0.7
16
0.3
0.2
~
11
0.86
0.62
0.67
11
270,000.
1.9
1.7
0.46
1
0.024
Calculated Risks
Adult Child
1.8 x 104
1.6 X 104
4.5 x 104
2.0 X 104
8.2 X 104
1.5 X 10-1
2.5 X 104
5.3 x 104
3.2 X 104
1.4 X 104
1.3 X 10-1
0.4
." %%
2.7 x 10"
1.6 X 104
3.8 x 104
2.0 X 10-4
6 .. 0 X 10-1
1.1 x 10°
1.9x 104
2.6 x 10-4
1.6 X 10-1
6.0 X 104.
S . 6 X 10-1
3.0
Calculated Risks
Adult Child
1.7 x 104
2.0 x 10"
1.5 x 10"
1.4 x 10"
3.0 x 10"
7.5 X 10-2
9.2 x 10°
2.4 x 10"
2.8 X 10-4
3.5 x 10"
2.0 X 104
4.5 X 104
9.0
2.5 x 10"
2.0 x 10"
1.4 x 10"
1.3 x 10"
4.0 x 10"
5 .5 x 10-1
6.7 X 10+1
1.8 x 10"
1.3 X 104
1.7 X 104
1.0'x 104
2,.2 X 10-2
70.0
BPC - Exposure Point Concentrations
cPAHs - sum of carcinogenic Polycylcic Aromatic Hydrocarbons
tPAHs - total Polycyclic Aromatic Hydrocarbons
27 .
-------
Tabla 6-6 RISE ~:&JtAC'1'BRIZATIOH POR nIUCT
CONTACT WITH St1JlPICUL SOILS bv.l:ud US.)
PPP III
Calculated Risks
~ Adul t Child
Cancer Bffects
Arsenic 4.6 7.0 x 1004 1.0 x 10'"
r::PAH8 4.2 8.4 x 10'" 8.3 x 10'"
J.>ieldrin 0.0069 1.5 x 1004 1.3 x 1004
9.0 x 10'" 1.0 x 10'"
Non-Cancer Bffects
Arsenic 4.6 3.1 x 10~ 2.3 X 10.1
Pluoride 12,000 4.1 x 10.1 3.0 x 10°
Nitrate 5.6 7.1 x 1004 5.2 x 10'"
Methylene Chloride 0.027 7.5 x 104 3.4 x 10'"
Di-n-butylphthalate 1.2 9.0 x 10'" 4.5 x 10'"
tPAH8 9.3 1.9 x 10~ 9.3 x 10~
Aldrin 0.005 4.3 x 10" 1.9 x 10~
4,4'-DDB 0.0056 2.5 x 10'" 1.1 x 10"
Dieldrin 0.0069 4.5 x 10" 1.9 x 10~
Bndosulfan I 0.0041 7.7 x 10'" 3.7 x 10"
0.5 3.0
PO IV
Calculated Risks
~ Adul t Child
Cancer Effects
Ar8enic 56 8.6 x 10'" 1.3 x 10'"
cPAH8 76 1.5 x 10" 1.5 x 10"
Aldrin 0.047 8.8 x 1004 7.7 x 1004
Heptachlor 0.043 2.7 x 104 2 . 3 x 104
2.0 x 10" 2.0 x 10"
Non-Cancer Bffects
Arsenic 56 3.8 X 10-1 2.8 x 100
Fluoride 740 2.5 x 10~ 1. 8 X 10-1
Nitrate 1.9 2.4 x 1004 1.8 x 10'"
Acetone 96 1.6 x 10~ 7.2 X 10-2
Methylene Chloride 0.071 2.0 x 10'" 8.9 x 10'"
tPAHs 189 3.8 X 10-1 1.9 x 10°
Aldrin 0.047 4.0 x 10~ 1~ 8 X 10-1
Bndosulfan I 0.053 9.9 x 10" 4.8 x 10~
Heptachlor 0.043 2.8 x 10" 1.2 x 10~
0.9 5.0
28
-------
Tabl. 6-'
RISE CllARACTBRIUTIOR I'OR J)IUC'1'
HCOHTAC'l' WITH SOJUPICUL, SOILS ("u',I;ud US.)
"8call .1.14
lEe
Calculated Risks
Adult Child
Cancer Effects
Arsenic
8.9 X 1.04
9.0 X 10-4
5.8
Non-Cancer Effects
Arsenic
Pluoride
3.9 X 104
1..8 X 1.0+1
20
5.8
530,000
1..] x 1.0'"
1.0 x 10'"
2 .9 X 10.1
1. .] x 1.0+2
100 '
l'ozm8r J)rall18.ge J)1 ~=
Calculated Risks,
Adult' Child
lEe
Cancer Effects
cPAHs
Dieldrin
2.0 x 1.0'"
5.1. x 1.0~
5.0 x 10~
1
2.3
Non-Cancer Effects
Methylene Chloride
Di-n-butylphthalate
tPAHs
Dieldrin
1.6 X 10-4
3.6 x 10~
5.3 x 10"
1..5 x 1.0°
0.0056
4.8
2.6
2.3
2.0 x 10'"
4.4 x 1.0~
5.0 x 10~
7.0 x 10"
1.8 x 10"
2.6 X 104,
6.4 x 1.0°
.-----------.-----.----------------------------------------------
Note:
BPC Exposure Point Concentrations '
cPAHs - sum of carcinogenic Polycylcic Aromatic Hydrocarbons
tPAHs - total Polycyclic Aromatic Hydrocarbons
29
-------
Tabla 6-8
RISI: CHARAC'l'BJlIZATICDr POR DIUCT
COR'l'AC'l' WITH Stm1'ICIAL SOILS (UCAVATIOIT)
PPP I
Cancer Effects
cPAHs
Non-Cancer Efft!cts
Arsenic
Fluoride
Nitrate
Di-n-butylphthalate
tPAHs
4 , 4' - DM
Dieldrin
Cancer Effects
Non-Cancer Effects
Arsenic
Fluoride
Nitrate
Acetone
Di-n-butylphthalate
tPAHs
Bndosulfan I
~
Calculated Risks
7.8
1.3 X 10-6
2.0 X 10-6
12
4500
2
0.7
16
0.3
0.2
8.2 x 10~
1.5 X 10-1
3.1 X 10-6
5.3 x 10'"
3.2 x 10~
1.4 x 10~
1 . 3 x 10-1
4.0 X 10-1
PPP II
~
Calculated Risks
11
270,000
1.9
1.7
0.46
1.0
0.024
7.5 x 1()~
9.2 x 10°
2.4 X 10-6
2.8 X 10-4
3.5 x 10'"
2.0 x 10'"
4.5 x 10'"
9.0
------------------------------------------------------~---------
BPC - Exposure Point Concentrations
cPAHs - sum of carcinogenic Polycylcic Aromatic Hydrocarbons
tPAHs - total polycyclic Aromatic Hydrocarbons
30
-------
!'8b18 6-9
.. R.ISE CBARAC"l'DIZATIOW I'OR. I)IUC!'
COH'l'AC'l" WID SURPICnr" SOILS (BZCAVA!'IOIt)
.... III
Cancer Effects
Non-Cancer Effects
Arsenic
Pluoride
Nitrate
Methylene Chloride
Di-n-butylphthalate
tPAHs
Aldrin
4, 4 ' - DDB
Dieldrin
Bndosulfan I
Cancer Effects
cPAHs
Non-Cancer Effects
Arsenic
Pluoride
Nitrate
Acetone
Methylene Chloride
tPAHs
Aldrin
Bndosulfan I
Heptachlor
~
4.6
12,000
5.6
0.027
1.2
9.3
0.005
0.0056
0.0069
0.0041
lEe
56
740
1.9
96
0.071
189
0.047
0.053
0.043
Calculated Risks
3.1 X 104
4.1 X 10-1
7.1 x 10"
7.5 x 10"
9.0 x 10'"
1.9 X 104
4.3 X 10"
2.5 x 10"
4.5 x 10"
7.7 x 10"
0.5
.... IV
Calculated Risks
76
1.3 x 10'"
3.8x 10-1
2.5 x 104
2.4 x 10"
1.6 X 104
2.0 x 10'"
3.8 X 10-1
4.0 X 104
9.9 X 10"
2.8 X 10"
0.9
I
---------------------------------------------------~--~----------
Note':
BPC - Exposure Point Concentrations
cPAHs - sum of carcinogenic Polycylcic Aromatic Hydrocarbons
tPAHs - total Polycyclic Aromatic Hydrocarbons
31
-------
!fabl. 1-10
1.181: ~UACTBI.IZATIOIT 1'01. DIUC"t
CmrrACT WITH StmJI'ICIAL SOILS (JaCAVATIC5)
8a.8ball 1'1.14
ec
Calculated Ri8k8
.Can~er Bffe~t8 .
Non-Can~er Bffe~t8
Arsenic
Pluoride
5.8
530,000
3.9 X 104
1.8 :x 10+1
18
I'ormer Drainage DI tah
ec
. Calculated Ri8k8
Can~er Bffe~t8
Dieldrin
2.3
4.2 X 104
Non-Can~er Bffect.
Methylene Chloride
Di-n-butylphthalate
tPAH8
Dieldrin
0.0056
4.8
2.6
23
1.6 X 104
3.6 x 10"
5.3 x 10"
1.5 X 10°
2.0 -
-----------------------------------------------------------------
BPC - Exposure Point Concentrations .
~PAHs - sum of car~inogenic Polycyl~ic Aromatic Hydrocarbons
tP~ - total Polycy~lic Aromatic Hydrocarbons
32
-------
Risks calculated for the hypothetical scenario are higher.than
current risk estimates because of exposure to constituent8. in
subsurface as well as surficial soils, higher exposure .
.frequencies associated with residential exposure, and additional
exposure pathways. Constituent concentrations were assumed to
remain at current levels, and an additional receptor (8ite
excavation worker) is also considered.
In summary, fluoride, tPABS, and dieldrin contribute most
significantly to non-cancer risks. Pluoride contributes most
significantly to the hazard indices on the baseball field. The ..
PAHs and dieldrin pose the worst health hazard in the former
drainage ditch area. In addition, cPAHs and dieldren contribute
most significantly to cancer risks in the drainage ditch area and
the PPP IV area. The subchronic assessmen~ of lead exposure to
potential on-site children conclude that the leve18 of lead in
on-site soils in the area of PPP IV are sufficiently contaminated
to be of health concern. .
Uncertainty is inherent in the risk assessment proce88. Bach of
the three basic buil~ing blocks for risk assessment (monitoring
data, exposure scenarios, and toxicity values) contribute
uncertainties. Environmental sampling itself introduces
uncertainty, largely because of the potential for uneven
distribution of constituents in environmeotal media. However,
the use of upper-bound assumptions, no attenuation, and the
conservatism built into the reference doses and cancer .lope
factors are believed to result in an over-estimate of human
health risk. Therefore, actual risk may be lower than the
estimates presented here but are unlikely to be greater.
6.6
BNVIRONMKNTAL tISE
Potentially exposed populations in the environment include: (1)
those at the site, (2) threatened or endangered species in the
area, and (3) the bayou communities. A study of the Bayou Texar
is currently being conducted to assess the extent of (1) the
contaminated ground-water plume associated with the aite and (2)
potential impacts to bayou communities. Once the bayou .tudy is
complete, an environmental risk assessment for impacts fram
ground water can be concluded.
Vegetation communities within the site consist of open
field/scrub-shrub mix: forested (oak and wax ~le): potential
wetland; and open field. The site is predominantly covered by an
open field/scrub-shrub community. This biotic communi~y is .
characterized by a predominance of woody vegetation not exceeding
approximately 6 feet in height. Potential wetland area8 are
located in the western section of the site and adjacent to the '
borrow pit and near the Interstate off-ramp. These areas are
predominantly vegetated by cattails. A jurisdictional wetland
review will be conducted for the 8ite and included with the .
33
-------
II
.ubsequent Bayou Texar .tudy. Terrestrial effect8 from expo8ure
to constituents in surficial .oils at the .ite either through
direct contact or from fugitive dust are likely to be har.mful to
vegetation in some instances. Constituents detected in on-.ite
-surficial soils at concentrations potentially toxic to vegetation
include aluminum, arsenic, chromium, fluoride, manganese, and
sodium. By rem~diating surface soils for fluoride, the potential
for exposure of the biota to the other 8urface 80il. contaminant.
should also decrease. Except for the area of PFP II, no vi.ible
signa of stressed vegetation has been observed. R~mediatioD of
.oil. in the PFP II area will eliminate .tress to tbe vegetation
in this area. Animal inhabitants on site are limited to
invertebrates (insects and worm&). Vertebrate8 (e.g., bird8 and
rabbits) may occasionally pass through the site, but the site is
not conducive to providing a habitat for a resident population.
Therefore, wildlife exposure to site contaminants is expected to
be low to sporadic.
Actual or threatened releases of hazardous substances fram this
site, if not addressed in implementing the response action
selected in this ROD, may present an imminent and .ubstantial
endangerment of public health, welfare or the environment.
7.0
7.1
DBSCRIPTION OP ALTBRNATrvBS
REMEDIAL ACTION OBJBC'1'rvBS
Soil cleanup goals are required for direct contact, ingestion and
inhalation of dust (risk-based). A .oil level is a180 nece..ary
which is protective of ground water (leachability-based), for
both organic and inorganic constituent..
Risk based remediation goal. were determined for several exposure
scenarios. Due to the expected continued industrial zoning at
the Agrico site, risk based action levels based on an. indu.trial
cancer risk of ~l04 i8 considered appropriate. Remedial goa18
that are protective of ground water were also developed. A
number of contaminants evaluated in the Baseline Ri8k A8se8ament
and the Feasibility Study are not assigned remediation goals;
because the contaminant was present, but in very low
concentrations or isolated areas. Also, those contaminants that
were determined not to be site related were not assigned
remediation goals. Thi. included the organic contaminants. A
variety of methods were used to develop these-goals.
The method used to determine the leachability-based cleanup level
for organic component8 was the Summers Model. The SUmmers model
assumes that 80me percentage of rainfall will infiltrate and
desorb constituents present in the soil matrix which will -
eventually reach the ground water. This adsorption mechanism i.
based on 80il:water partition coefficients.
34
-------
[,
~timate1y, remediation goals were appropriate for fluoride,
arsenic, an~ lead. The remedial go&l established for fluoride is
based on protection of ground water. P1uoride, arsenic and lead
are considered representative of the entire inorganic profile and
-are used as target compounds.- The remedial goals established for
lead and arsenic are calculated based on health based 80il
exposure scenar~os.
To determine a cleanup level for fluoride in soil protective of
ground water, a site specific approach was developed. The
cleanup 1e',e1 for fluoride is calculated based on the 1I\&7"""mI
allowable perimeter ground-water concentration of 4 me/l for
fluoride, and translated to a maximum allowable total
characteristic leachate parameter (TCLP) concentration via a
dilution factor. The calculation account8 for the mixing and
dilution in the aquifer, does not assume any retention, or
attenuation of constituents in saturated soil, and presents a
worst case, maximum concentration effect of leachate on ground
water. This approach was recommended by the Plorida Department
of Bnvironmental Regulation (PDER), with BPA concurrence. In
addition, the calculation used was based on total fluoride
concentrations found in the soil. Based on the above .ite
specific approach, the soil remediation goal for total fluoride
was calculated to be 1,463 me/kg.. .
The lead contamination i8 confined to surficial 80ils in the area
of PFP IV. In addition, the lead and is not impacting the ground
water. Therefore, the lead remediation goal of 500 me/kg i8
based on health risk associated with the hypothetical future
child residential scenario. The conservative approach for a lead
cleanup goal was determined by the lead uptake/biokinetic (OBX)
model. The soil cleanup number represents the concentration which
the model predicts would result in 95t of a hypothetical future
child residential population having a blood lead concentration
less than the Agency benchmark of 10 ug/al.
The remedial goal for arsenic in soils of 16 me/kg is based on an
industrial scenario at the 104 risk level based on ingestion and
inhalation pathways. In summary, the s01l remediation goals are:
Chemieal
Remediation
Goals (D19/ka)
Fluoride
Lead
Arsenic -
1,463 .mg/kg
500 me/kg
16 mg/kg
. - J
Based on soil treatability studies conducted as part of the PS,
solidification/stabilization of the fluoride will result in
solidification/stabilization of the lead and arsenic as vell.
Lead is known to have a low mobility in soils. Site specific
35
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data .upports the assumption, because the lead contamination i.
confined to .urficial .oils in the area of PFP IV only.
7.2
VOLtDmS
The volumes of .ludge and contaminated soils have been calculated
based on the estimated boundaries of the pond areas PPF I, II,
III, and IV and the inorganic constituent concentrations found CD
site. The horizontal extent of .oil contamination is limited to
the area documented to be the approximate boundary of the pond
areas (+/- 25 feet). The vertical extent of .oil contamination
i. limited to roughly a depth of 10 to 15 feet beneath the
majority of the pond areas. The soils are contaminated to a
depth of 25 to 30 feet fram an area extending fram the expo.ed
portion of Pond PFP II in a northwesterly direction towarda the
east end of PFP I.
The total volume of soil. present beneath the estimated PFP pond
boundaries, to a depth of 25 feet is approximately 600,000 cubic
yards (ey). The volume of soils and sludge containing fluoride
concentrations exceeding the .ite specific clean up level for
fluoride is approximately 400,000 ey. The volume of sludge CD
site is 32,500 ey. The volume of soil. exceeding fluoride,
arsenic, and lead clean up level. in the area of PFP IV i. 20,800
ey.
In summary, volumes of soil. and sludges to be remediated at the
site are as follow.:
.
Soil. (low to moderately contaminated)
Soils (highly contaminated)
400,000 yeS'
20,800 yeS'
32,500 yeS'
.
.
Sludge (highly contaminated)
\
7.3
un.
Section 121 (d) (2) (A) of CBRCLA specifies that Superfund
Remedial Actions must either meet any Pederal standard,
requirement, criteria or limitations that is determined to be an
applicable or relevant and appropriate requir~ent (ARAlt). ARAR8
fall into three categories: contaminant-specific; location
specific; and action-specific. Same rule. do not specifically
apply to a remedial action, however, because of their .ubject
matter, they may provide some guidance in implementing ~a cho.en
RA. These rules are called to-be-considereda (TBC.). Potential
ARAR.8 and TBCs are discussed below. .
Pederal standards regarding action-specific ARARs for 80il.
36
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I
I
management relate to the manner in which the selected remedy i.
implemented." Regulations regarding capping and landfill.
construction are included in 40 CPR 264.228," 40 CPR 264.258, aDd
.40 CPR 264.310 pertaining to closing a landfill, surface
impoundment or waste piJ.e as a landfill. Additional capping
standards regulate post-closure use of property to prevent damage
to the cover, and management of run-on and run-off. General
performance standards are included in 40 CPR 264.111 for clean
closure.
"Chemical-specific ARARa, other criteria, and site-related factors
serve to initially identify remedial alternatives. Chemica1-
specific ARARs define acceptable exposure levels and therefore
are used in establishing remediation goal..
The chemical ARARs for ground-water constituents detected at the
Agrico site were obtained fram the promulgated proposed " primary
maxtmum contaminant levels (MCLs) for drinking water for the
State of Plorida (P.S. 17-550). In instances where there i. DO
state MCLs for a given constituent, proposed or promulgated
Pedera1 MCLs (40 CPR 141) are referenced to identify ground-water
ARARs. According to the NCP, MCLs are only used for ARARs when
the MCLGs are zero. In other instances, MCLGs will take
precedence over MCLs. If there are no Federal MCLs for a given
constituent, health-based criteria are developed using Federal
Water Quality Criteria (PWQC), Lifettme Health Advisories (RAs)
and reference doses (RfD). The technical approach and
calculations were derived under the guidance of BPA and PDBR, and
are discussed previously in Section 7.1.
7.4
DBVBLOPKBN'l' AND SCUBNING OF AL'l'BRNA'1'ZVBS
7.4.1 PROCBSS
". As a part of the process, the FS pre1tminari1y evaluate. the
" number of different technologies for remedial action. The
,technologies are generally evaluated on the basis of their
effectiveness, implementabi1ity and cost in relation to the
remedial action goals for the site. After the screening, four
major alternatives were determined to be worth developing into
detailed alternatives for evaluation as the final cleanup plan.
For ease of crossreference with the FS, this ROD has maintained
the numbering system used in the FS. The retained alternatives
are as follows: "
Alternative 1
Alternative 4
No Action
SOlidification/Stabilization, RCRA
Multtmedia Capping, Slurry Wal;L
Alternative ,
Solidification/Stabilization, RCRA
Clay Capping, Slurry Wall
37
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,[
Alternative 8
Soil Washing, Solidification/
Stabilization, Clay capping, Slurry Wall'
Off-Site Disposal, SOlidification/
Stabilization, Consolidation, Clay Cap
Alternative 10 -
7.4.2 ALTBRNATIVB 1 - 50 AC'l'IOIT
Kajor Components of the Remedial AlternatiYe - The National
Contingency Plan (NCP) requires the development of a no action
alternative as a basis for comparison with the other
alternatives. The No Action alternative is presented .s .
baseline case. The No Action alternative would include the U8e
of deed restrictions to limit site acce.s and land use to prevent
site development or any excavating of contaminated .oil. (or
sludge) on the 8ite. These restrictiona would prevent dermal
contact or ingestion of contaminants. However, this alternative
does not meet the remedial action objectives. for preventing
dermal contact, ingestion, or mitigation of ground-water
contamination.
Since construction would not be involved in thi8 alternative, the
implementability concerns, engineering, equipment and material.,
health and safety, and schedule are not applicable. Because no
ground-water monitoring would be conducted under this
alternative, there would be no cost associated with quarterly
sampling and analyses. Therefore, there is' no estimated pre.ent
worth costi nor i8 there capital C08t included with this No
Action alternative.
7.4.3
ALTBRNATIVB 4 - SOLIDIPICATION/STABILIZATION. ROA
CAPPING. SLURRY WALL .
Kajor components of the Remedial AlternatiYe - This alternative
includes the excavation and consolidation of the impacted .oil.
above 1,463 mg/kg of fluoride fram PPP I, PPP III, and PPP IV
into PFP II. This alternative a180 includes excavation,
sOlidification/stabilization, and consolidation of the impacted
80ils above 500 mg/kg of lead and 16 mg/kg of arsenic fram PPP IV
into PPP II. All sludge from all PFPs would be excavated,
stabilized, and consolidated into PPP II. A .lurry wall would be
constructed around PPP II and adjacent areas. A multimedia RCRA
cover system would be constructed over the area enclosed in the
slurry wall. This alternative would also include ground-water
quality monitoring, access, and deed restrictiona. I
Containment Component - The containment of the
sOlidified/stabilized material and low to moderately contaminated
soils would prevent direct contact risk and continued .
c ,:amination of the ground water from leachate generation. The
c~~struction of a low permeability cap over the stabilized
material and moderately contaminated soils would minimize the
38
f
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" '" "rOo..,'" "
f ( ,~. ';': :";
,
amount of rainfall infiltrating through it. 'the multimedia RCRA
cap would be. comprised of a min~ of seven layers of materials
of various thickness. In ascending order, these layers include:
.1) landfill preliminary grade; 2) compacted .clay layer; 3)
flexible membrane liner; 4) drainage layer; 5) geotextile fabric;
6) general fill; and 7) topsoil. The construction of a slurry
wall would el~nate lateral movement of .perched. water zones
through the fill area. The wall would not be anchored to a
subsurface impermeable rock formation, but would be built to a
depth of 30 feet, which is 20 feet above the water table. %D
addition, the slurry wall will be approximately 2 to 4 feet in
width. .
General CompoDent - The soils, located outside of the proposed
cap area, containing fluoride at concentrations exceeding the
remedial action criteria of 1,463 mglkg would be excavated aDd
consolidated into the RCRA containment area. In addition, 80i18
contaminated above 500 mg/kg of lead and 16 mglkg of arsenic fram
PPP IV would be excavated, stabilized, and consolidated into PPP
II. Sludges in the containment area would be excavated aDd
stabilized, using a combination of sludge, Portland cement, fly
ash, and other additives to improve physical and chemical
characteristics of the sludge. Construction of a ber.med area.
adjacent to PPP II would provide an area to stockpile stabilized
sludge. Dewatering of excavation areas, especially PPP II, would
probably be necessary. At a minimum, a 10,000 gallon tanker
truck or above-ground portable pools would be utilized for
storage of construction water. Construction of the slurry wall
around the containment area would entail excavation of a trench,
which would be backfilled with a fluid cement or bentonite aDd
80il mix.
The capital cost for this alternative i8 estimated to be
$10,347,000. The total present worth cost of the alternative 1s
$10,730,000.
un. CompoDent - The maj or federal ARARs aDd 'l'BC. for this
alternative areas follows: '.
Safe Drinking Water Act, 40 CPR 141.11 -141.16, 141.50,
141.51;
. Resource Conservation and Recovery Ac~ (RCRA) -
Proposed Rule for Corrective Action for Solid Waste
Management Unit, 40 CPR Parts 264.111, 264.258, 264.228,
264.310; 40 CPR 261 Land Ban.
.
The major State ARARs and 'l'BCs are as ~0110W8:
.
Plorida Drinking Water Standards, PAC 17-550.
This alternative will meet all Pederal and State ARARs.
39
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,."." ALTBRNATIVB '7 - SOLIDIPICATION/sTUILIZATIOH. t!f.1Y
CAPPPING. SLURJlY 1f-.T.T.
Major Components of tb. 18m.dial Alt.rnatiV8 - This alternative .
"includes the excavation and consolidation of the impacted .oil.
above 1,463 mg/kg fluoride fram PFP I, PFP III, and PPP IV into
PFP II. In addition, 80ils contaminated above 500 mg/kg of lead
and 16 mg /kg of. arsenic from PPP IV would be excavated,
stabilized, and consolidated into PPP II. All highly
contaMinated sludge and soi18 fram all PPP8 would be excavated,
stabilized, and con80lidated into PPP II. A .lurry wall would be
constructed around PPP II and adjacent area.. A clay cover
8ystem would be constructed over the area enclo.ed in the slurry
wall. This alternative would al.o include ground-water quality
monitoring, acces., and deed restricti0D8.
Containment Component - The containment of the
solidified/stabilized material and low to moderately contaminated
soils would prevent direct contact risk and continued
contamination of the grou~d water fram leachate generation. The
construction of a low permeability clay cap over the stabilized
material and moderately contaminated 80ils would minimize th.
amount of rainfall infiltrating through it. The clay cap would
be comprised of a minimum of compacted clays and top.oil covera.
The construction of a slurry wall would eliminate lateral
movement of .perched. water zone. through the fill ar... The
wall would not be anchored to a subsurface impe~eable rock
formation, but would be built to a depth of 30 feet, which i. 20
feet above the water table.
QeD.ral Component - The .oil., located out.ide of the propo.ed
cap area, containing fluoride at concentrations exceeding the
remedial action criteria of 1,463 mg/kg would be excavated and
consolidated into the clay cap containment area. Soil.
contaminated above 500 mg/kg of lead and 16 me/kg of ar.enic from
PFP IV would be excavated, stabilized, and consolidated into PPP
II. All highly contaminated sludges and .oil. in the containment
"area would be excavated and stabilized, using a combination of
sludge, Portland cement, fly ash, and other additives to improve
physical and chemical characteristic. of the sludge.
Because the 80ils and sludges treated under a clay cap mu.t meet
stricter clean up 8tandards than those under a RCRA cap, the
volume of treated 80ils and sludges would be 'ignificantly
greater for thi8 alternative. The clay layers would be installed
in loose lifts, and compacted to specified density t9 attain the
desired pe~eability. Construction of a be~ed area adjacent to
PFP II, and dewatering of excavation areas, would be necessary.
As in alternative 4, construction of a .lurry wall around the"
containment area would entail excavation of a trench, which would
be backfilled with a fluid cemen~ or bentonite and .oil mix. Tbe
capital cost for this alternativ i. $13,500,000. The total
40
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~ :' :< of' . ;\j.,: ~:.
---.~.~; :1" .." ~.~ -'~,-"'~'. - .
present worth cost is $13,657,000.
AVR8 Componct - The major federal ARARs and DCs for this.
alternative are as follows: .
Safe Drinking Water Act, 40 CPR 141.11 -141.16, 141.50,
141.51: .
8 Resource Conservation and Recovery Act (RCRA) -
Proposod Rule for Corrective Action for Soli~Waste
Managanent Unit, 40 CPR Part8 264.111, 264.258, 264.228,
264.310; 40 CPR 261 Land BaD. .
8
The major. State ARARs and TBC8 are a8 fol1owa:
8 Florida Drinking Water Standards, FAC 17-550.
This alternative will aeet all Federal and State ARARa.
7.C.5 ALTBRNATrvB 8 - SOIL WASBrNQ~ SOLIDIPICATIOR/
STABILIZATION ~ CLAY CAPPINQ~ SL17R.R.Y .&T.T.
Kajor Component. of the Remedial Alternativ8 - The 80i18, located
outside of the proposed cap area, containing fluoride at
concentrations exceeding the remedial action criteria of 1,463
mg/kg would need to be excavated and consolidated into the clay
cap containment area. Soils contaminated above 500 mg/kg of lead
and 16 mg/kg of arsenic from PPP IV would be excavated, treated,
and consolidated into PPP II. All highly contaminated 80i1s fram
all PPP ponds would be excavated, soil washed and subsequently
used as clean backfill. A slurry wall would be constructed
around PFP II and adjacent areas. A clay cap system ~ou1d be
constructed over the area enclosed in the slurry wa11~ This
alternative would also include ground-water quality monitoring,
access, and deed restrictions.
Containment Componct - Soil washing of the highly contaminated
soil would significantly reduce the volume of sludges/soi18 to be
managed within the containment area. The containment of the
stabilized material and moderately contaminated soils would
prevent direct contact risk and continued contamination of the
ground water from leachate generation. '!'he construction of a low
. permeability clay cap over the stabilized material and low to
moderately contaminated soils would minimize the amount of.
rainfall infiltrating through it. The clay cap would be
comprised of a mintmum of compacted clays and topsoil covers.
'!'he construction of a slurry wall would eliminate later,al
movement of .perched. water zones through the fill area.
General Component - Soil washing involves treating the
contaminated 80ils and sludges by remoVing a wide range of
organic and inorganic contaminants. The treatment works upon the
41
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concept that contaminants have a propensity to reside in specific
particle grain-size domains. The system separates the waste
stream into four major .cuts. and focuses treatment appropriate
'to this contaminant/grain size relationship. The final product
of this process would be a much reduced volume of froth and
sludge which wo~ld require disposal at a hazardous waste
facility. The larger volume of .c1ean. soil would be returned to
the site. The sOlidification/stabilization of remaining soils
would be done in the same manner as the previously discussed
alternatives. In addition, the construction of the clay cap and
slurry wall would be conducted in a similar fashion as
alternatives 4 and 1. The capital cost for this alternative is
$28,221,000. The total present worth of this alternative is
$28,488,000.
ALU8 Component - The major federal ARAR.s and TBCs for this
alternative are as folloW8:
.
Safe Drinking Water Act, 40 CPR 141.11 -141.16, 141.50,
141.51;
Resource Conservation and Recovery Act - Prop08ed Rule
for Corrective Action for Solid Waste ~gement Unit, 40
CPR Parts 264.111, 264.258,264.228, 264.310; 40 CPR 261
Land Ban.
.
The major State ARARs and TBCs are as follows:
.
Florida Drinking Water Standards, FAC 11-550.
This alternative will meet all Federal and State ARARs.
7.4.6 ALTERNATIVB 10 - CON'1'AINMBN'l' "Im CLAY CAP. SLURRY "1r.r..
SOLIDIPICATION/STABILIZATION. AND OPP-SITS DISPOSAL
Kajor Component - Remedial Alternative 10 consists of the
excavation and consolidation of impacted soils exceeding 1,463
mg/kg of fluoride fram PFP I, PFP III, and PFP IV into PFP II.
Soils contaminated above 500 mg/kg of lead and 16 mg/kg of
arsenic fram PFP IV would be excavated, treated, and consolidated
into PFP II. All highly contaminated soils from PFP II would be
transported offsite for disposal at a RCRA facility. A slurry
wall would be constructed around PFP II and the adjacent impacted
area. A clay cap and soil cover would be constructe~ over the
PFP II containment area containing stabilized material iand
moderate to low contaminated soils. Ground-water monitoring
would also be conducted. Access and deed restrictions would also
be implemented as part of this alternative remedy.
Containment Component - The containment of the
solidified/stabilized material and moderately contaminated soils
42
-------
would prevent direct contact risk and continued contaminat~on of
the ground water from leachate generation. The construction of a
low permeability cap over the stabilized material and low to
. ~erately contamianted soils would minimize the amount of
rainfall infiltrating through it. The clay cap would be
comprised of a minimum of compacted clays and topsoil covers.
The construction of a slurry wall would eliminate lateral
movement of .perched. water zones through the fill area. The
disposal off-site of the highly contaminated soils and sludges
would greatly reduce the ,rolume of treated soils/sludges within
the containment area, and would provide enhanced containment of
the most heavily impacted sludges/soils.
General CompoDent - Alternative 10 would greatly minimize future
generation of impacted ground water by excavating and
transporting the highly contaminated soils and sludges for off-
site disposal to a RCRA facility. 40 cn 268 requires the BPA to
evaluate each RCRA sludge to determine if land disposal
prohibitions are appropriate. Careful consideration of this
fe4eral regulation would be required to successfully implement
this alternative. The sOlidification/stabilization of the
remaining sludge would be done in the same manner as the ,
previously discussed alternatives. In addition, the construction
of the clay cap and slurry wall would be conducted in a similar
fashion as alternatives 4, 7 and 8. The capital cost for this
alternative is $39,946,000. The total present worth of this
alternative is $40,206,000.
.u.u.. CompoDent - The major federal ARARs and TBCs for this
alternative are as follows:
Safe Drinking Water Act, 40 cn 141.11 -141.16, 141.50,
141.511
. Resource Conservation and Recovery Act - Proposed Rule "
for Corrective Action for Solid Waste Management Unit, 40
CPR Parts 264.111, 264.258, 264.228, 264.3101 40 CPR 261
Land Ban.
.
The major State ARARs and TBCs are as follows:
. Plorida Drinking Water Standards, PAC 17-550.
This alternative will meet all Pederal and State ARARs.
8.0 SmDtU.Y OF '1'BB COMPAltATIVB ANALYSIS OF ALTBRHATIVBS
This section of the ROD provides the basis for determining which
alternative provides the best balance with respect to the
statutory balancing criteria in Section 121 of CBRCLA and in
Section 300.430 of the RCP. The major objective of the PS is to
develop, screen, and evaluate alternatives for the remediation of
43
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the Agrico Chemical site.
1.1 CRITERIA peR EVALUATING 'RRM'1mIALAL"l'KRNA'1'%VBS
-The remedial alternatives selected from the acreening proceaa are
evaluated using the following nine evaluation criteria:
Overall Protection of Human Health an4 the RDviroDment - Assesses
degree to which alternative eliminates, reduces, or controla
health and environmental threats through treatment, engineering
methods, or institutional control..
Compliance with Applicable or .elevant an4 Appropriate
Requirements - Assesses compliance with Pederal/State
requirements.
Coat - Weighs the benefits of a remedy against the cost of
implementation.
1mplementability - Refers to the technical feasibility and
administrative ease of a remedy.
Short-Term Effectivene.. - Length ~f time for remedy to achieve
protection and potential impact of construction and
implementation of a remedy.
Long-Term Effectivene.. - Degree to which a remedy can maintain
protection of health and environment once cleanup goal. have been
met.
Reduction of Toxicity, XObility, or VolWILe 'l'hrough Treatment -
Refers to expected performance of the treatment technologies to
lessen harmful nature, movement or amount of contaminant..
State Acceptance - Consideration of State'. opinion of the
preferred alternative.
Community Acceptance - Consideration of public comment. on the
Proposed Plan.
The NCP categorizes the nine criteria into three groups:
e
'l'hreaho14 Criteria - overall protection of human health
and the environment and compliance with ARAR8 (or
invoking a waiver) are threshold criteria that must be
satisfied in order for an alternative to be eligible
for selection; . i
Primary Balancing Criteria - long-term effectiveness
and permanence; reduction of toxicity, mobility, or
volume; short-term effectiveness; implementability, and
cost are primary balancing factors used to weigh major
.
44
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I I
I'
.
trade-offs among alternative hazardous waste management
st.rategies; and
MOdifyiDg Criteria - state and community acceptance are
modifying criteria that are formally taken into account
after public comment is received on the proposed plan
and incorporated in the ROD.
The selected alternative must meet the threshold criteria and
comply with all ARARs or be granted a waiver for compliance with
ARARs. Any alternative that does not satisfy both of these
requirements is not eligible for selection. The Primary
Balancing Criteria are the technical criteria upon which the
detailed analysis is primarily based. the final two criteria,
known as Modifying Criteria, assess the public's and the 8tate
agency's acceptance of the alternative. Based on these final two
criteria, BPA may modify aspects of a specific alternative.
The following analysis is a summary of the evaluation of
alternatives for remediating the Agrico Chemical Superfund Site
under each of the criteria. A comparison is made between each of
the alternatives for achievement of a specific criterion.
Thr..bo14 Criteria
8.2 OVERALL PRO'l'BCTIOH 01' B'tJMAH 1nI!a.L'1'K AND '1'BB BNVIRONMBR'l'
All of the alternatives, except the no-action alternative, are
protective of human health and the environment by eliminating,
reducing, or controlling risk through treatment of 80il
contaminants, engineering controls, and/or institutional
contro18. .
Alternatives 8 and 10 provide the best long-ter.m protection to
human health and the environment from direct contact with the
impacted material, through treatment (8) and off-site disposal
(10). However, potential short-ter.m exposures to the community
during excavation for treatment and off-site disposal. of the
waste reduce the overall protectiveness of this alternative.
Alternatives 4 and 7, through containment, would provide similar
and acceptable levels of overall protection, since the proposed
cover systems prevent dermal contact and ingestion of
contaminated. soils/sludge. Alternatives 4 and 7 also minimize
infiltration of surface water and resulting generation of
leachate, and are protective of ground water. The institutional
controls associated with alternatives 4, 7, 8, and 10 minimize
site usage through deed restrictions and, therefore,"fUrther
reduce exposure to contaminants remaining onsite.
Since the no-action alternative does n~t eliminate, reduce, or .
control any of the exposure pathwaY8, it is therefore not
protective of human health or the environment and will Dot be
45
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considered further in this analY8is a8 an option for the so~l
wastes.
1.3 COMPLIANCE WITS APPLICABLB OR RELEVANT AND APPROPR~TB
RBOt1IItEMKN'1'S
Of the five (5) alternatives evaluated, Alternative8 4, 1, 8, and
10 will attain or exceed ARARs. These alternatives include
source control remedial actions (capping and stabilizing) that
wo~ld achieve site specific and remedY/8ite 8pecific cleanup
leve18 to be protective of ground water and to attain the State
of Plorida drinking water standards for the impacted aquifer.
prtmary Balancing Criteria
1.4 LONG-TERM BPPBCTIVENBSS AND PBRKANBHCK
Excavation and 80lidification/stabilization cl08ure is proposed
in all of the alternatives. The RCRA cap (4), in conjunction with
the slurry wall, would function to provide the ground water a
greater degree of protection throughout the life of the cover
system than the clay caps (7), (8), and (10) since the annual
infiltration rates for a RCRA and clay cap are less than .25 and
2 inches, respectively. Alternatives 8 and 10 would immediately
reduce the residual risks at the site through treatment or off-
site removal of the highly contaminated soils and sludges. The
potential risks associated with alternative8 4, 7, 8, and 10 are
perched water and ground water. The risks should be greatly
minimized within five years for all alternatives.
1.5 REDUCTION OP TOXICI'l'T. KOBILI'l'T OR VOLmm THROUGH 'l'Rn'l'MD'l'
Only Alternative 8 implements treatment to reduce the volume and
subsequently the mobility. Alternatives 4, 7, 8, and 10 employ
stabilization to effectively reduce mobility and provide enhanced
load bearing capacity. These alternatives contain the 8011
contamination, therefore the mobility is reduced.
8.6 SBORT-TERM BPPBCTrvBHBSS
Alternatives 4, 7, and 10 have the potential to provide the best
short-term effectiveness. Alternative 8 has lower short-ter.m
effectiveness due to the length of implementation time and
potential adverse impacts on human health and the environment.
I
Alternatives 4, 7, 8, and 10 involve earthwork at the site and
have the potential to provide 8imilar protection to the community
and on-site workers during construction activitie8. Measures may
be required at the site during earthwork activities associated
with these alternatives to reduce the potential for fugitive dust
emissions. The heavy earth moving equipment required to
implement these alternatives may create noise nuisances for
46
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nearby residents during remediation activities. In addition,
alternatives 8 and 10 require additional contaminated .oil
handling for soil washing and off-site deposal of soi18/8ludges,
respectively. .
Al ternati ve 8 will require adherence to strict operation
procedures to protect the community during remediation
activities. Alternative 8 may require the most 8tringent
monitoring and health and safety plan due to the nature of the
proposed treatment technology.
Alternatives 4, ." 8, and 10 are expected to 8ignificantly rec:tuce
the potential for direct human or wildlife contact with the
contaminated soils. In addition, these alternative8 will
virtually eliminate the hypothetical risks at the site ~
removing the potential exposure pathway..
1.7 %MPLBMENTABILITT
Alternative 7 is the most implementable of the four alternative8
that involve full scale remedial activitie8;although,
alternative 4 is very similar and the level of increa8e4
difficulty with implementation is .minimal. Due to quality
assurance and control tasks required to construct/install the
HDPB membrane of the RCRA cover, alternative 4 would be .lightly
more difficult to implement than alternative 7. However, .
alternatives 4, 7, 8, and 10 contain many of the same components;
therefore, the level of difficulty to implement would be 8imilar.
Alternatives 8 and 10 possess additional logi8tics problems
associated with soil washing. and off-site disposal, respectively.
In addition, alternative 8 would require the construction of an
on-site soil washing facility.
8.8 ~
The comparative present worth cost of the four alternative. are
as follows:
Alternative 4
Alternative 7
Alternative 8
Alternative 10
$10,730,000
$13,657,000
$28,488,000
.$40,206,000
XodifyiDg Criteria
8.8 STATE ACCBPTABCB
J
The State of Plorida, as represented by the Plorida Department of
Environmental Regulation (FDD), has been the support agency
during the Remedial Investigation and Peasibility Study process
for the Agrico Chemical Site. In accordance with 40 CPR 300.430,
FDER, as the support agency, has provided input during thi.
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process. Based upon comments received from FDER, it is expected
that concurrence will be forthcoming; however, a formal letter of
concurrence has not yet been received. . .
'. ., COMMCNI'l'!' ACCBPTAHCB
The community had no major concerns about the remedy BPA proposed
for public comment. The concerns of the community are discussed
in detail in the Responsiveness Summary, which is Appendix A of
this ROD.
'.0 SBLECTED .~
Based on consideration of the requirements of CBRCLA, the KCP,
the detailed analysis of alternatives and public and stat.
comments, BPA has selected Alternative 4 as the source control
remedy for this site. At the completion of this remedy, the risk
associated with this site has been calculated at an industrial
1x10~ which is within BPA's acceptable risk range of 1x10~ to
1xlO~. BPA has determined that this risk range is protective of
human health and the environment. The total present worth cost
of the selected remedy, Alternative 4, i. estimated to be
$10,730,000.
Kajor Components of the ..medial Alternative - This alternative
includes the excavation and consolidation of the impacted soils
above 1,463 me/kg of fluoride from PPP I, PPP III, and PPP IV
into PFP II. Soils and sludge contaminated with lead above 500
mg/kg and arsenic above 16 mg/kg in the area of PPPIV would be
excavated, stabilized, and consolidated into PFP II. All sludge
from all PFPs will be excavated, sOlidified/stabilized, and
consolidated into PPP II. A slurry wall shall be constructed
around PFP II and adjacent areas. The construction of a slurry
wall would eliminate lateral movement of .perched. water zones
through the fill area. The wall will not be anchored to a
subsurface impermeable rock formation, but will be built to a
depth of 30 feet, which is 20 feet above the water table. A
multimedia RCRA cover system shall be constructed over the are.
enclosed in the slurry wall.
This alternative will also include ground-water quality
monitoring, access, and deed restrictions. A deed restriction or
a perpetual conservation easement pursuant to Section 104 (j) of
CBRCLA and in accordance with the provisions of Section 704.06,
Florida Statutes (1990) is appropriate after completion of
remedial action of the source material at the site. . I
Treatment Component - The solidification/stabilization technology
utilizes a feed system, mixing vessels, and a curing area. The
excavated material is mixed with a variety of stabilization
reagents and sorbents. The types of materials possibly used for
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80lidification could include cement kiln duet, lime kiln dust, or
fly ash. So.rbents that might be added to the stabilization
process could include natural or modified clays, zeolites,-
activated alumina, or activated carbon.' (Soil treatability
'studies currently recommend the formation of calcium fluoride
(caP), whose solubility in water is 20mg/L, to immobilize the
fluoride) . .
CODtainment CampOD~t - The containment ' of the
solidified/stabilized material and low to moderately ,contaminated
soils will prevent direct contact risk and continued ,
contamination of the ground water from leachate generation. '!'he
construction of a low permeability RCRA cap over the stabilized
material and moderately contaminated soil will minimize the '
amount of rainfall infiltrating through it. The multimedia I.CIA
, cap is comprised of a minimum of seven layers of material. of
various thickness. In ascending order, these layers include: 1)
landfill preliminary grade; 2) compacted clay layer; 3) flexible
membrane liner; 4) drainage layer; 5) geotextile fabric; 6)
general fill; and 1) topsoil. The construction of a ,slurry wall
will eliminate lateral movement of .perched. water zones through
the fill area. The slurry wall will not be anchored to a
subsurface impermeable rock formation, but will be built to .'
depth of 30 feet, which i. 20 feet above the water table.
General CompOD~t - The 80ils, located outside of the proposed
cap area, containing fluoride at concentrations exceeding the
remedial action criteria of 1,463 me/kg will be excavated and
consolidated into PPP II, the RCRA containment area. Tbi8
alternative also includes ex~avation,
sOlidification/stabilization, and consolidation of the impacted
soils above 500 mg/kg of lead and 16 me/kg of arsenic from PPP rv
into PPP II. All sludge from all PPP ponds will be excavated,
stabilized, and consolidated into the PPP II area, with the
remaining low to moderately contaminated soi18. A slurry wall
shall be constructed around PPP II and adjacent areas.
A mul timedia RCRA cover system shall be constructed over the PPP
II pond and adjacent areas. This alternative shall 'also include
ground-water quality monitoring, access, and deed restrictions.
Construction of a bermed area adjacent to PPP II will, provide aD
area to stockpile stabilized sludge. Dewatering of excavation
areas, especially PPP II will probably be necessary. As a
minimum, a 10,000 gallon tanker truck or above-ground portable
pools will be utilized for storage of construction water.
Construction of the slurry wall around the containment area .ill
entail excavation of a trench, which will 'be backfilled with a
fluid cement or bentonite and soil mix. :.
'.rforma..uc. StancSard8 (Bxcavaticm)
Performance standards for excavation of the soils/8ludges were
49
..
. - --. -. -. -
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developed to protect human health, to prevent contamination of
the ground water and to be in compliance with ARAR8. Bxcava~ion.
shall continue until the remaining soi18/8ludge8 are at or below
the 8elected performance standards. All excavation shall cauply
with ARARs. Testing methods approved by BPA shall be used to
determine wheth~r the performance standards have been achieved.
The .tandards selected for the chemical. of concern are ..
follow.:
Chemical
..rformaDce
S tancSarcS8 (ag /kg)
Fluoride
Lead
Arsenic
1,"63
500
16
..rfo:nunc. StancSarcS8 ('1'r.atment/CoDtainmct)
After the contaminated material has been excavated, all .ludge
from PFP I, II, III, and IV will be excavated and stabilized
before being placed into the containment area. The 8tabilization
of the sludges must attain strength requirement. (50 p.i) for
installation of a RCRA cap. USBPA OWSBR Directive, No. 9437.00-
2A considers 50 psi sufficient unconfined compres.ive .trength
for supporting a final cover and the construction equipment
necessary for in8talling the cover.
I
The installation of a RCRA Cap to contain .tabilized .ludge. and
contaminated soils will reduce the infiltration of surface vater
to a negligible amount, thereby all but eliminating the
generation of leachate containing fluoride. The reduced
infiltration rate was calculated using the Hydrogeologic
Evaluation of Landfill Performance (HELP) model. The
infiltration rate was calculated to be le8. than .25 inche.per
year, based on the climatological data for Mobile, Al~ma, 50
miles west of Pensacola, and geotechnical properties of locally
available soils to be utilized for the construction of the low
permeability clay .oil layer and .oi18 for the final cover of the
RCRA Cap.
The performance standards for this component of the .elected
remedy include, but are not limited to, the fQllowing
treatment/containment .tandards:
.
. .
so
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II
Parameter
Perfonaance
StancSard '
1x10-locm/ see
'1'e.tiDg
lletbocSology . '
BPA Method 9100-SW846
-Permeability,
Strenath Testina
Unconfined
Compressive
Strength
Penetrometer
50 psi
50 psi
AS'DoI D2166
ASTM D1558-MOdified
Because certain perfo~ce standards may not be determined until
the Remedial Design phase, and because more minor perfo~ce
standards need not be listed, it should be understood that the
list of perfo~ce standards in this section is not exclusive
and may be subject to addition and/or modification by the 'Agency
in the RD/RA phase. '
.un. CompoDent - The major federal ARARs and TBCs for this
alternative are as follows: '
Safe Drinking Water Act, 40 CPR 141.11 -141.16, 141.50,
141.51~
. Resource Conservation and Recovery Act - Proposed Rule
for Corrective Action for Solid Waste Management Unit, 40
CPR 264.111, 264.258, 264.228, 264.310~ 40 CPR 261 Land
Ban.
.
The major State ARARs and TBCs are as follows:
.
Florida Drinking Water Standards, FAC 17-550.
This alternative will meet all Federal and State ARARs.
Co.t
The capital cost for alternative 4 is $10,346,700.
worth for Operations and Maintenance is $384,313.
present worth for alternative 4 is $10,731,013.
10.0 STA'1'tJ'1'ORY DB'l'BRXIHA'1'IOHS
The present
The total
Under its legal authorities, BPA's primary responsibiltty at
Superfund sites is to select remedial actions that are protective
of human health and the environment. In addition, Section 121 of
CBRCLA establishes several other statutory requirements and
preferences. These specify'that when complete, the selected
remedy for this site must comply with applicable or relevant and
51
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appropriate environmental standards established under Pederal and
State environmental laws unless a statutory waiver is justif.ied.
The selected remedy also must be cost-effective and utilize .
permanent solutions and alternative treatment technologies or
resource recovery technologies to the maximum extent practicable.
Pinally, the statute includes a preference for remedies that
employ treatment that permanently and significantly reduce the
volume, toxicity, or mobility of hazardous wastes as their
principal element. The following sections discuss how the
,elected remedy for the Agrico Chemical site meets these
statutory determinati0n8.
10.1 PRO'l'BC'J.'IOH OF JmKMr wwa.L'l'B U1) TBB KNVIROHMID1'1'
The selected remedy for the Agrico Chemical Site protects human
health and the environment through extraction and treatment of
the affected on-site soils. Treatment of the contaminated soils
on site will effectively reduce risk from exposure to surficial
soils as well as prevent further contamination of the ground
water. The combined institutional controls along with the
monitoring requirements will serve to ensure protection of human
health and the environment.
The current risk associated with the site i. a non-carcinogenic
risk for on-site residents. Pluoride contributes most
significantly to the hazard indices of 5 for an adult and 40 for
a child. The current risk associated exposure to lead in
surficial soils, as a result of modeling, is a 100 percent child
population having a blood lead level above 10 ug/L.
Hypothetical future risks
site excavation worker is
hazard indices using this
adult to 100 for a child.
Through implementation of the selected remedy risk levels should
be effectively reduced to acceptable levels. Potential short
term risks will be controlled through the utilization of standard
engineering practices.
to adults, children resident., and on-
based on exposure to fluoride. The
scenario range from under 1.0 for an
10.2 COMPLIANCE WITS APPLICABLE OR ULKVAN'1' U1) APPROPRn'l'B
REOUIRBMBN'l'S
Section 121 (d) (2) (A) of CBRCLA incorporate. into the law the
CBRCLA Compliance Policy, which specifies that Superfund remedial
actions must mmet any federal and state standards, re~irements,
criteria, or limitations that are determined to be legally
applicable or relevant and appropriate requirements (ARARa).
Also included is the provision that state ARARs must be met if
they are more stringent than federal requirement..
Applicable requirements are defined as cleanup standards,
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standards of control, and other substantive environmental
protection requirements, criteria,. or limitations promulgated,
under Pederal or State law that specifically address a hazardous
.substance, pollutant, contaminant, remedial action, location, or
other circumstance at a CBRCLA site.
All potential ARARs for treating the contaminated soils and
sludge at the Agrico Chemical Site are presented below. The
recommended alternative was found to meet or exceed the following
ARAR.8 .
10.2.1 Chemical Specific apa_.
Clean Water Act (CWA) I Safe Drinki~CI Water Act (SDn)
Safe Drinking Water Act (40 C.P.R. 141, 142, and 143), which
specifies the MCLs for the contaminants of concern that will be
applicable as the remediation levels for contaminated ground
water. However, should the State drinking water standard under
Plorida Administrative Code (PAC) 17-550, for a particular
contaminant be more stringent, the State standard will be used as
the remediation level. (Applicable requirement)
. .
Clean Water Act (40 C.P.R. 122-125), which specifies the
substantive requirements of the National Pollutant Discharge
Blimination System (NPDBS) applies to handling of construction
water around PFP II. Should the State effluent limitations for
surface water, under 17-302, be more stringent, the State
standard will be applicable.. (Applicable requirement)
Resource Conservation aDd Recoverv Act (RCRA)
40 C.P.R Part 261 Land Ban - The RCRA land disposal restriction
(8LDR8) (40 CPR 268) promulgated in the 1984 HSWA amendments
require that RCRA hazardous wastes be treated to BDAT (Best
Demonstrated Available Technologies) Standards prior to placement
into the land. . BPA promulgated treatment standards in May 1990.
The onsite wastes are characterized as RCRA wastes for lead and
arsenic, because the wastes exhibit TCLP Toxicity as defined 40
CPR 261. Excavation and treatment in a separate unit is
considered to be placement under RCRA LDR. Therefore, LDR will
be an applicable/or relevant and appropriate requirement. The
selected remedy will meet BDAT standards Por RCRA characteristic
waste. The treatment process will immobilize the metals to the
extent that the waste will not longer be hazardous waste &s
define by RCRA. (Applicable requirement) I
Plori4a administrative Cod. ~ter 17-3
Construction of the RCRA cap and slurry wall would insure that
water quality standards are met for surface water and ground .
water affected by leachate and sto~ runoff fram the site.
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10.2.2 Action Specific aequir888Dta
...ource Conservation and .ecoverv Act (.~)
40 C.P.R. Part 264 Subpart G - Closure and Postclosure require.
capping standards to regulate post-closure use of the property to
prevent damage to the cover, and management of run-on, run-off.
(Applicable requirement)
40 C.P.R. 264.228, 40 C.P.R.2S8, 40 C.P.R. 264.310 - Capping and
landfill construction standards pertaining to closing a landfill,
surface impoundment or waste pile a. a landfill are applicable
and will be met when implementing the selected remedy.
(Applicable requirement)
Florida Admini.trative Code ~pter 1'.'01
PAC 17.701 establishes standards for landfill con.truction,
capping, and disposal of .olid waste. (Applicable requirement)
Florida Admini.trative Code ~~ter l'.'J'
PAC 17-736 requires that warning .igD8 be placed on all .ide. of
the fenced containment area (RCRA cap and slurry wall) with the
warning that there i. a hazardous wa.te .ite pre.ent. (Applicable
requirement)
10.2.3
Location Specific .equir8m8Dt
Bn~."a.red Species Act (.SA) .
The selected remedy is believed to be protective of .pecie.
listed as endangered or threatened under the BSA. Requirements
of the Interagency Section 7 Consultation proce.., 50~PR Part 402
will be met. The U.S. Department of Interior (DOl) and the u.s.
Pish and Wildlife Service will be consulted during the RD to
. ensure that endangered or threatened specie. are not a~er.ely
impacted by implementation of this remedy. There i. currently no
information to indicate that the .ite i. vi.ited by or contain8
.uch species. (Relevant and Appropriate requirement)
.ation.l Hi.toric.l Pre.ervation Act (HBPA)
The NHPA requires that action be taken to preserve or recover
historical or archaeological data which might be destroyed a. a
result of site activities. No information exist. to indicate
that the Agrico Chemical site has any hi.toric or archaeological
.ignificance. (Relevant and Appropriate requirement)
10.3 COST BrPBCT~v£NBSS
This remedy employs a proven technology which can be e..ily
54
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This remedy employs a proven technology which can be easily
. implemented at the Agrico Chemical' Site. This technology'
provides the most cost effective treatment when compared to the
'other alternatives due to its ability to most effectively treat
and limit further spread of contamination.
.
10.4 'D"I'ILIZATION OF PERMANENT SOLtJ'l'IONS AND ALTERNATIVE 'l'REA'l'MJm'l'
TECHNOLOGY OR RESOURCE RECOVERY TECHNOLOGIES TO THE MAX~
EXTENT PRACTICABLE ..
, EPA and the Florida Department of Environmental Regulation have
determined that the selected remedy represents the maximum extent
to which permanent solutions and treatment technologies can be
utilized in a cost effective manner for contaminant treatment at
the Agrico Chemical site. Of those alternatives that are
protective of human health and the environment and comply with
ARARs, EPA and the State have determined that the selected remedy
provides the best overall balance of tradeoffs in terms Of the
five balancing criteria: long-term effectivenessi and permanencei
reduction of toxicity, mobility, or volumei short-te~
effectiveness; implementabilitYi and cost. Additionally, the
selected remedy fulfills the two modifying criteria: state
acceptancei and community acceptance.
The selected remedy meets the statutory preference to utilize
permanent solutions and treatment technologies, to the mayimum
extent practicable. Remediation of the source will effectively
remove the threat from. exposure to surficial contamination and
will prevent further contamination of the ground water.
10.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL BLEMENT
By treating the source and through institutional controls, the
selected remedy addresses the principal threats posed to human
health and the environment by the site through the use of a
proven treatment technology. Therefore, the statutory preference
for remedies that employ treatment as a principal element is
satisfied. .
10.6 DOCUMENTATION OF SIGNIFICANT CHANGES
The Proposed Plan for the Agrico Chemical site was released for
public comment on August 6, 1992. The Proposed Plan identified
Alternative.. as the preferred alternative for this action. SPA
reviewed all written and verbal comments submitted during the
public comment period. . I
SPA has determined that a significant change to the remedy, as it
was originally presented in the Proposed Plan, is necessary. SPA
has determined that a remedial goal of" 16 mg/kg for arsenic is .
appropriate for the site based on a risk level of 104 for an
ss
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industrial scenario. This change may increase the estimated
volume of soils in the PFP IV area to be excavated and .
stabilized. The increase in volume could affect the estimated
cost of the remedy. The changes in volume and cost will be
determined during Remedial Design.
S6
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