United States Off ice of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R09-92/078
March 1992
SEPA Superfund
Record of Decision:
Pacific Coast Pipeline, CA
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NOTICE
The appendices listed in the index that are not found in this document have been removed at the request of
the issuing agency. They contain material which supplement, but adds no further applicable information to
the content of the document. All supplemental material is, however, contained in the administrative record
for this site.
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50272-101
REPORT DOCUMENTATION 11. REPORTNO.
PAGE EPA/ROD/R09-92/078
I~
3. Reclpienta Ac:c:eaaion No.
.. n..8nd~
SUPERFUND RECORD OF DECISION
Pacific Coast Pipeline, CA
First Remedial Action - Final
7. Aulhar(a)
5. Report DatAl
03/31/92
6.
8. Ferformlng Organization Repl No.
I. Iwfol1011I11 Org8InIzdon ...... and AddnI88
10. ProjectlTuklWork Unit No.
11. Contract(C) or Gl'ant(G) No.
(e)
(G)
12. Spon8orIng 0rgar8zatI0n Nur8 and Addr8a8
U.S. Environmental Protection
401 M Street, S.w.
Washington, D.C. 20460
13. Type of Repor1& Period Covered
Agency
800/000
14.
15. SupplamltDl' No...
PB93-964502
18. Ab8nc:t (lImI1: 2110 _Ida)
The 20-acre Pacific Coast Pipeline site, located in Ventura County,California, is a
former petro-chemical refinery that operated from the 1920's to 1950. The site is
currently used by Texaco as a pumping station for crude oil produced in local oil
fields. Surrounding land use is industrial, agricultural, and residential. The site
is located near the confluence of three major drainages: the Santa Clara River, Sespe
Creek, and Pole Creek. Prior to the construction of a flood channel, Pole Creek
emptied directly into the site. Surface water from the site is either channeled for
collection in bermed storage areas or in excavated pits, or it flows into Pole Creek
through drainage pipes or over the ground's surface. The San Cayetono Thrust Fault
that crosses the site is associated with areas of natural oil seeps. From 1928 to
1950, refinery wastes were disposed of onsite in a large main waste pit (MWP) as well
as in eight smaller unlined sumps and pits located on the South Western portion of the
site. Monitoring wells installed by Texaco have identified 45 chemicals of potential
concern detected at the site, including VOCs, SVOCs, and TPHs. In 1986, under state
guidance, Texaco removed 33,000 cubic yards of waste material and contaminated soils
from the MWP and the eight other waste disposal areas. There are currently two areas
(See Attached Page)
17. Doc:um8nt An8Iy8I8 L Dncripto..
Record of Decision - Pacific Coast Pipeline, CA
First Remedial Action - Final
Contaminated Media: gw
Key Contaminants: VOCs (benzene, ethylbenzene, methyllene choride, toluene) other
organics
b. Identi~Tenna
c. COSAlI R8kIIGroup
-- 18. AL - - iI1y Statement
I
11. Security caaas (This Repor1)
None
20. Security CI8aa (Thia Page)
None
21. No. of Pages
46
22. Price
See ANSI-Z39.18
See ImtructiOf16 on Ratte,.
272(4-17)
(Formed, N11~)
Oepar1rnent of Commerce
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EPA/ROD/R09-92/078
Pacific Coast Pipeline, CA
First Remedial Action - Final
~stract (Continued)
of groundwater contamination: one beneath the MWP and one in the southwest site area.
The source of this ground water contamination is likely associated with the disposal of
refinery wastes in the MWP and other waste disposal pits. Since the removal of the
refinery wastes in the MWP, concentrations of ground water contamination have decreased.
This ROD addresses remediation of ground water to reduce contaminant levels below federal
and state drinking water standards. The principal contaminated media are soil and ground
water. The primary contaminants of concern affecting the soil in thevadose zone and
ground water are VOCs, including benzene, 1,2-dichloroethane, ethylbenzene, methylene
chloride, and toluene; andother organics.
The selected remedial action for this site includes soil vapor extraction for areas that
threaten to contaminate ground water at levels above site clean-up standards following a
1-year subsurface study; design, construction, and operation of a ground water extraction
and treatment system using multiple extraction wells to treat extracted ground water
using activated carbon to levels that meet clean-up standards; discharge of treated
ground water to the onsite aquifer by injection or provision of treated ground water to
beneficial uses; ground water monitoring to demonstrate that the extraction system is
effectively capturing the contaminant plume and achieving clean-up standards throughout
the aquifer; and maintenance of perimeter fencing until clean-up standards are met.
Assuming a 3D-year operational period, the estimated present worth cost is $7,000,000,
which includes an annual O&M cost of $480,000.
PERFORMANCE STANDARDS OR GOALS: Chemical-specific clean-up goals for ground water in the
aquifer are based on state MCLs, and the TBCs State Action Level for toluene, including
~enzene 1 ug/l (state); 1,2-DCA 0.5 ug/l (state); ethylbenzene 680 ug/l (state);
methylene chloride 5 ug/l (proposed MCL/TBC); and toluene 100 ug/l (state action
level/TBC) .
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PACIFIC COAST PIPELINE
(TEXACO FILLMORE REFINERY)
SUPERFUND SITE
RECORD OF DECISION
u.s. EPA
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TABLE OF CONTENTS
Page
List of Figure s.................. ..... """""""'''' ........... ..................... ......................... ....... ............... ii
List of Tables... ......... ...... ......... .................... ........................ ..... .................... .......... ......... ....... ii
Declaration for the Record of Decision............. ..................... '''''''''''''''''''''''''''''' ..................1
Decision Summary......... """,,,,,,,,,,, .... ......... .......................... ........................ ........................ 3
1
Site Name, Location and Description........... ..................................... 3
n
Site History and Enforcement Activities............................................ 6
ID.
Highlights of Community Involvement..............................................6
IV.
Scope and Role of the Response Action............................................ 8
v.
Summary of Site Characteristics[[[ 9
VI.
Summary of Site Risks. ............... .... ........ .......... ......., ....... ........ ..... ..... 14
vn.
Description of Alternatives. '"'''''''''''''''''' ......... .......................... ....... 24
vm.
Summary of Comparative Analysis of Alternatives........................... 31
IX.
Selected Remedy.. ........ .,....... ... ......... ... ................. ............ ................ 37
x.
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Figure #1
Figure #2
Figure #3
Table A
Table B
Table C
Table D
Table E
Table F
Table G
LIST OF FIGURES
Paee
Site :Location Map............. '''''''''''' .......................... ........ .......4
Locations ofW aste Disposal Areas......... ........... .................... 9
Aquifer#l Benzene Plume. .................................................. 13
LIST OF TABLES
Pa~e
Waste Pit Materials.. '"'''''''''''' ......... ......... ............ ......... .................... 7
Primary VOCs in Ground Water and Cleanup Standards.................. 12
Potential Compounds of Concern and Criteria for
Selection. ............ ......... .............. ............... ...... ......... ........ ............ ...... 15-16
Exposure Scenarios and Assumptions............................................... 18-19
Selected Toxicity Values for Compounds of Concern....................... 20-23
Risk Characterization for Ground Water............................................ 25-26
Risk Characterization for Surface Soils.............................................. 27
ii
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STIE NAME AND LOCATION
Pacific Coast Pipeline
Texaco Fillmore Facility
67 East Telegraph Road
Fillmore, CA
STATEMENT OF BASIS AND PURPOSE
This Record of Decision (ROD) presents the remedial action selected for the Pacific Coast Pipeline (also
referred to as the Texaco Fillmore Facility) Site ("the Site") in the City of Fillmore, County of Ventura,
California. This remedial action was chosen in accordance with the Comprehensive Environmental
Response, Compensation and Liability Act of 1980 (CERCLA), as amended by the Superfund
Amendments and Reauthorization Act of 1986 (SARA) (42 U.S.C.~9601 ~.), and, to the extent
practicable, with the National Oil and Hazardous Substances Pollution Contingency Plan (NCP)(40
U.S.C.~300 ~.). The attached Administrative Record Index (Attachment A) identifies the documents
upon which the decision is based. The State of California concurs with the selected remedy.
ASSESSMENT OF THE SITE
If the actual or threatened releases of hazardous substances from the Site are not addressed by
implementing the remedial response action selected in this ROD, the Site may present an imminent and
substantial endangerment to public health, welfare, or the environment.
DESCRIPTION OF THE REMEDY
EPA has selected Alternative 6 as the remedy for the Pacific Coast Pipeline Site. The selected remedy
for contaminated ground water at the Pacific Coast Pipeline Site consists of:
1) Design, construction and operation of a ground water extraction and treatment system to
treat extracted ground water to levels that meet the cleanup standards set forth in this ROD;
2) Discharge of treated ground water to the aquifer at the Site by injection or provision of the
treated ground water to beneficial users of the tteated ground water;
3) Soil Vapor Extraction for those areas that threaten to contaminate ground water at levels
above Site cleanup standards following a one year subsurface study;
4) Ground water monitoring to demonstrate that the extraction system is effectively
capturing the contaminant plume and ultimately, to demonstrate achievement of the cleanup standards -
throughout the aquifer; and
I
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5)
Maintenance of perimeter fencing at the Site until cleanup standards are met.
Implementation of this remedy will prevent the spread of ground water contamination and reduce the
principal risk of exposure to contaminated ground water. The ground water extraction and treatment
system will operate until the cleanup standards are achieved through the aquifer. Because this remedy
will not result in hazardous substances remaining on the site above health-based levels, the five-year
review will not apply to this action. The selected remedy will undergo periodic performance evaluations
at a frequency to be determined in the Remedial Design Workplan.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the environment, complies with Federal and State
requirements that are legally applicable or relevant and appropriate for the remedial action, and is cost-
effective. This remedy uses permanent solutions and alternative treatment technologies to the maximum
extent practicable and satisfies the statutory preference for remedies that employ treatment to reduce
toxicity, mobility, or volume as a primary element.
2i9 gui-
"
-
M~ ~I; /99-L
Daniel W. McGovern
Regional Administrator
Date
2
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CONCURRENCES
PACIFIC COAST PIPELINE SITE
RECORD OF DECISION
Nancy Marvel, Regional Counsel
Office of Regional Counsel
Harry Seraydarian
Water Management Division
.s 1-5//92
Date
Date
Date
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CONCURRENCES
PACIFIC COAST PIPELINE SITE
RECORD OF DECISION
Nora McGee
Assistant Regional Administtator
Office of Policy and Management
~"", l;;' :/j/ /:.-.<,,- ----t~'')~
:.' J
Nancy Marvel, Regional Counsel
Office of Regional Counsel
Harry Seraydarian
Water Management Division
Date
'~ "/. /::::;..
',' .,' I cr-
/
Date
Date
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CONCURRENCES
PACIFIC COAST PIPELINE SITE
RECORD OF DECISION
Nora McGee
Assistant Regional Administrator
Office of Policy and Management
Nancy Marvel, Regional Counsel
Office of Regional Counsel
.'
.". .
-,. ,f. /."t.--
./.-....:....-v..-? ..' ...' J'''',?""~,,,-'
,..,./Harry Seraydarian
. Water Management Division
Date
Date
3 I ....;/~..........,;...--~ 1."/.:-
Date
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DECISION SUMMARY
This Decision Summary provides an overview of the problems posed by the Pacific Coast
Pipeline Site. It also includes a description of the remedial alternatives considered and the analysis of
these alternatives against criteria set forth in the National Contingency Plan (NCP). This Decision
SommaTy explains the rationale for the remedy selection and how the selected remedy satisfies the
statutory requirements of CERCLA.
I.
SITE LOCATION AND DESCRIPTION
A.
SITE NAME AND LOCATION
Pacific Coast Pipeline
Texaco Fillmore Facility
67 East Telegraph Road
Fillmore, CA
B.
SITE DESCRIPTION
The Pacific Coast Pipeline (Texaco Fillmore Facility) site (the "Site") is located in Ventura
County, California. on the eastern edge of the City of Fillmore (see Figure #1). The Site address is 67
East Telegraph Road, Fillmore, California. The 20 acre Site was the location of a fonner Texas Company
Inc. ("Texaco") petro-chemical refinery which operated from the 1920s to 1950. The Site is currently
used by Texaco as a pumping station for crude oil produced in the local oil fields of V entura County. The
Site is located just north of State Highway 126, which runs in an east to west direction betWeen U.S.
highways 101 and 5.
C.
LAND AND WATER USE
Along the western boundary of the Site are residential homes and San Cayetano Elementary
School. To the nonh and east of the Site is vacant land with some agricultural use. Industrial and resi-
dential properties are located to the south of the Site. To the southwest of the Site is a gas station that re-
moved leaking fuel tanks in 1989.
Private agricultural, industrial and residential ground water supply wells exist within a half mile radius
of the Site. An onsite production well is used to irrigate the orChards on a hill to the east of the Site. City
of Fillmore municipal welIs are located to the southwest of the Site. These wells are planned for use by
the City of Fillmore.
The Site surface structures include large holding tanks, piping and a small operations building.
There are no wetlands on or near the Site.
D.
REGIONAL TOPOGRAPHY
The Site is located betWeen the Topa Topa Mountains to the northwest and the Fillmore ground
water basin to the southwest. Site elevations range between 480 to 625 feet above mean sea level. The
3
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BASE MAP: USGS 7.5 MIN. FILLMORE QUADRANGLE
PHOTOREVISED 1969
@
o 1000 2000
I . I
SCALE IN MIL.ES
KEY MAP
4
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Santa Dara River is approximately one half mile to the south of the Site. The Site slopes generally to the
south and west toward the Santa Clara River and is bordered on the west by Pole Creek, the natural surface
water drainage system in the immediate vicinity of the facility. The average topographic gradient is above
0.05 foot per foot.
The Site is located near the confluence of three major drainages: the Santa Clara River, Sespe
Creek and Pole Creek. Pole Creek emptied directly into the Site prior to the construction of a flood control
channel. Water in the Pole Creek Flood Control Channel discharges into the Santa Clara River. Surface
water from the Site is either channeled along graded roads for collection in benned storage areas or in
excavated pits, or it flows into Pole Creek either over the ground's surface or through drainage pipes.
The San Cayetano Thrust Fault that crosses the Site is associated with areas of natural oil seeps.
Fractures associated with folding and fault zones can act as either seals or conduits for the migration of
fluids.
E.
HYDROLOGY
The Site lies at the eastern end of the Fillmore ground water basin. The Fillmore basin, the Piru
basin and the Santa Clara River Valley sediments fonn a large connected ground water system. The
ground water gradient slopes down toward the west with local variations reflecting irregularities along
the boundaries of the basin. At the Site, the Fillmore basin suddenly widens and the regional ground water
gradient turns towards the northwest on the north side of the Santa Clara River Valley. In the vicinity of
the Site, the gradient is estimated to be approximately 35-ft per mile (0.66-foot per 100 feet) toward the
west.
Geologic Units
The most correlative single soil unit at the Site is a fine-grained unit that occurs at a depth ranging
from 40 to 60 feet below grade. This unit is approximately one to five feet thick and has acted as a venical
barrier to water migration in scattered locations.
Another soil horizon with properties similar to the shallow fine-grained unit appears at a depth of
approximately 135 to 140 feet below grade. The textural properties and fine-grained composition of this
unit appear to make it an impediment to fluid migration. It serves as a substantial confining layer to aquifers
penetrated in at least eight deep monitoring wells. In each of these wells, ground water was initially
encountered at an elevation near 380 to 385 feet above mean sea level (msl). Subsequently, the water
elevation rose in the wells to approximately 395 feet above msl. The thickness of this soil unit varies
between one to 20 feet throughout the Site with the greatest thickness to the north of the Site and in the
vicinity of the main waste pit.
Ground Water
Three possible hydrogeologic units were identified during the Remedial Investigation. From the
surface down they are as follows:
A perched zone generally shallower than 40 to 50 feet below grade;
5
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Aquifer 1, is unconfined and found betWeen 80 to 100 feet below grade; and
Aquifer 2, is confined and found generally 100 feet below grade.
The base of Aquifer 1 is formed by the unit described as the deep fine- grained unit. Ground water
in this unit flows in a westerly or northwesterly direction. Aquifer 2 appears to be confined beneath the
same deep fine-grained unit, which is described above. Ground water in this unit flows in a northwesterly
direction. There appears to be some vertical migration of ground water down from Aquifer 1 to Aquifer
2 in the southern portion of the Site where the deep fme-grained soil unit is'thinnest.
-. D.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
Texaco operated a petroleum refinery at the Site from 1928 to 1950. The primary products of the
Texaco refinery were gasoline, diesel and fuel oil. Wastes from the refinery process are believed to have
consisted primarily of tank bottoms, fIlter clays, and sludges.
These refinery wastes were disposed of onsite from 1928 to 1950 in a large main waste pit (MWP)
located on the western border of the Site, and in eight smaller unlined sumps and pits located throughout
the Site. In 1950, Texaco dismantled and convened the refinery to a crude oil pumping station. It is
believed that the onsite refinery wastes disposal areas were not used since 1950.
In 1986, under the guidance of the California Depamnent of Toxic Substances Control (CA
DTSC), Texaco removed 33,000 cubic yards of waste material and contaminated soils from theMWP and
eight other waste disposal areas. These areas contained contaminants at concentrations considered to be
hazardous substances (DHS Criteria). The contaminants found in the MWP are listed in Table A.
Texaco installed a total of 17 ground water monitoring wells betWeen 1983 and 1988 voluntar-
ily and at the direction of the CA DTSC. These wells indicated that ground water at the Site has been
contaminated with a variety of petroleum rerming waste contaminants.
In June of 1988, the Site was proposed for the National Priorities List (NPL) and final listing
OCCUJTed in September of 1989. EP A conducted a Potential Responsible pany ("PRP") Search in 1989.
EPA issued a Special Notice Letter to Texaco on June 26, 1989. EPA and Texaco signed an
Administrative Order on Consent (AOC) for the Remedial Investigation and Feasibility Study ("RIlFS")
in October 1989. This agreement required Texaco to conduct the RIlFS at the Site under EP A's oversight.
For the next tWo and one-half years investigations were conducted by Texaco until sufficient
information was gathered to propose a remedy. The Feasibility StUdy which resulted in the seven
remedial action alternatives discussed in detail below was completed in February 1992.
fiL
HIGHLIGHTS OF COMMUNITY INVOLVEMENT
The Community Relations Plan (CRP) was completed in August 1989 by EPA Community
6
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TABLE A ...
Maximum Recorded Concentrations of Hazardous and Other Substances
From Excavated Main Waste Pit Material
.. . Compounds .. ::. Maximum Concentration (ppm)
Arsenic (As) 19.0
Barium (Sa) 140.0
Cadmium (Cd) 11.0
Chromium (Cr) 120.0
Lead (Pb) 3.700.0
Mercury (Hg) None Detected
Selenium (Se) 1.2
Silver (Ag) None Detected
Benzene 9.3
Toluene 16.0
Ethylbenzene 10.0
Alcohols (a) 200.0
Ketones(a) 100.0
Aliphatic and Alicyclic Hydrocarbons(a) 450.0
Aromatic Hydrocarbons(a) 140.0
Alkene and Alkyne Hydrocarbons(a) 120.0
(8) Individual compounds combined and reported in their major hydrocarbon groups.
7
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Relations staff, following EP A guidance. Development of the CRPwas based on a series of infonnational
interviews with members of the community. Consistent with the recommendations of the CRP, the EP A
Project Manager, communicated regularly with the parties that had expressed a high degree of concern
regarding Site activities and provided general fact sheets to the community to notify them of major
milestone events.
In November 1989, EPA issued a Fact Sheet to the community of Fillmore to announce the
signing of the AOC for the RIlFS with Texaco. Shonly after, the EPA project manager presented the
project RIlFS workplan to the Fillmore City Council and the teachers and staff of San Cayetano School.
The San Cayetano School is located directly on the western border of the property. The EPA project
manager met again with the teachers and staff of the school in April 1990. In July 1990, EPA issued a
second Fact Sheet and later in September met With parents of students at the school. A tour of the Site
forthe press and other interested community members was conducted by the EP A project manager in July
1990.
In December 1990, a third Fact Sheet was issued by EP A to announce the preliminary results of
the Remedial Investigation. No responses were received following the disnibution of this Fact Sheet.
In addition to effons to provide infonnation on the progress of the investigation to the commUnity,
a regulatory technical steering committee met regularly . The purpose of the committee has been to foster
communication relating to the Site activities at all levels of government. The committee includes
representatives of the City of Fillmore, the County of Ventura Environmental Health Depanment,
California EP A Department of Toxic Substances Control and U.S. EP A. The committee met regularly
throughout the Site RIIFS.
In February 1992, EP A issued a Proposed Plan outlining the remedial action alternatives for the
Site. An announcement was printed in the Fillmore Gazette on February 24, 1992, announcing the
Proposed Plan, public comment period and public meeting. EP A held the public meeting on March 10,
1992 at the San Cayetano Elementary School in Fillmore. The meeting was attended by 25 community
members and representatives of the City government. EP A received three comment letters during the
public comment period, which officially closed on March 25, 1992.
Details of community involvement activities and responses to public comments on the Adminis-
trative Record are presented in the Responsiveness Summary (Attachment B).
The public participation requirements of Sections 113(k)(2)(B)(i-v) and 117 ofCERCLA have
been satisfied in the remedy selection process.
IV.
SCOPE AND ROLE OF THE RESPONSE ACTION
The 1986 removal of the wastes and contaminated soil from the MWP and the other eight waste
disposal areas significantly reduced the amount of risk to human health and the environment at the Site.
Based on the results of the Risk Assessment prepared in December 1991, the residual extent and
concentration of contamination in the surface soils do not present a known significant threat to human
health or the environment. However, contaminant concentrations in the ground water exceed the Federal
and California standards for drinking water and may present an imminent and substantial endangerment
8
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SOURCE: RADIAN 1884, AS PRESENTED IN
FIELD SAtIotPLING PLAN FOR
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FIGURE :£
LOCATIONS OF
WASTE DISPOSAL AREAS
FILLMORE FACILITY
9
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to human health if not remediated. Therefore, remediation of the ground water is required to reduce con-
taminant concentrations in the ground water.
v.
SUMMARY OF SITE CHARACTERISTICS
A Remedial Investigation was conducted between December 1989 and February 1992. The
investigation program consisted of sampling programs to: (1) charaCterize known onsite areas where
hazardous substances were disposed of in the past and (2) screen for the presence of contaminantS that
may have migrated or are migrating from the Site. The screening program included sampling and analysis
of soil gas, stream sediment, surface water, and ambient air sampling. The sampling program to
characterize known areas of contaminant disposal included surface soil, su~surface soil and ground water
sampling.
A
SURFACE SOILS
Historical layouts and early Site investigation worlc provided a foundation for design of the surface
soil sampling program. The program was designed to provide a site-wide survey of possible surface soil
contamination.
A total of 36 surface soil samples were collected at the Site during the Remedial Investigation.
Surface soil sampling was conducted within 250 foot by 250 foot grids. Sample results indicated that in
areas of known and suspected past refmery waste disposal, volatile organic compounds (VOCs) ranged
from not-detectable to low-concentrations. In these same areas, semi-volatile organic compounds
(SVOCs) ranged from non-detect to concentrations in the hundred pans per billion (ppb) range for select
poly-aromatic hydrocarbons (PAHs), such as Chrysene. Figure #2 indicates the known and suspected
waste disposal areas.
Concentrations of metals throughout the Site are presently consistent with background samples.
B.
SUB-SURFACE SOn..
The extent of su~surface soil contamination was established from the analysis of 785 samples
from 78 exploratory boreholes drilled in known and suspected waste disposal areas and in uncontami-
nated areas to provide a bench-mark for natural Site conditions. The following section is a description
of the contaminants discovered during the Remedial Investigation.
Total Petroleum Hydrocarbons ITPH) and Tentatively Identified Compounds mC)
TPH was found throughout the Site, however high concentrations were predominantly in the
MWP and southwestern portion of the Site, corresponding with the areas of ground water contamination.
TIC were detected in prior disposal areas at the Site. TPH and TIC are not known to be of concern to
human health however.
Volatile Organic Compounds (\TOCs)
Toxicity Characteristics !aching Procedure (TCLP) for VOCs was conducted on approximately
10
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142 samples. Benzene was detected in 15 of 142 samples and was generally present in subsurface soils
below 11 ppb with a maximum concentration of 38 ppb. Ethylbenzene was detected in 42 of the samples
with concentrations ranging from non-detectable ("ND") to a maximum of 260 ppb. Toluene was
detected in 49 samples at concentrations ranging from ND to a maximum of 300 ppb. Xylenes were
detected in 58 samples ranging in concentration from ND to 860 ppb. Four other VOCs were detected
in sub-smface soils. However. they were only detected in one to two samples each and at low
concentrations.
Given the age of the facility and the 1986 removal of the refinery wastes from the waste disposal
areas. it appears that the majority of VOCs in the subsurface soils have either migrated to ground water.
volari1i7ed dispersing laterally and vertically. or degraded through natural processes.
Semi- Volatile Compounds (SVOCs)
The primary SVOCs detected included 2-Methylnaphthalene and Naphthalene. 2-Meth-
ylnapthalene was detected in 34 of the 154 samples with reponed results ranging from 10 ppb to 160 ppb.
Napthalene was detected in 60 samples at concentrations ranging from 10 to 160 ppb.
Metals
Metals concentrations presently in sub-surface soils were found to be consistent with background
levels for the Site and for the region.
SUMMARY
The lateral and vertical disttibution of VOCS and the range of VOC concentrations deteeted in sub-
surface soils do not indicate the presence of a principal threat in soil. However. the low levels ofVOCs
(specifically benzene) in the vadose zone or capillary fringe may result in ongoing contamination of
ground water. The investigation results indicate that studies must be conducted to determine the need
for response action in sub-surface soils in order to achieve the Site cleanup standards in ground water.
Data indicate that vadose zone contamination may threaten ground water quality.
c.
GROUNDWATER
Ground water contamination was originally detected in 1983 with the initial installation of three
monitoring wells. Water quality data from these wells indicated VOCs in the pans per million (ppm)
range. Fourteen additional monitoring wells were installed by Texaco at the Site prior to EPA
involvement at the Site. Between mid-l990 and mid-I991. 20 more monitoring wells were drilled and
completed at the Site as a pan of the Remedial Investigation bringing the total number of wells at the Site
to 37. These 37 wens have been sampled quarterly for TPH. VOCs. SVOCs. Metals and Ethylene
Dibromide (EDB).
Water quality data indicates that ground water contamination consists mainly ofTPH. TIC. VOCs
and SVOCs in Aquifer #1. VOCs have only been detected in Aquifer #2 in well 25D. VOC contami-
nation in ground water consists primarily of benzene. toluene, ethylbenzene and xylenes. These
11
-------
contaminants and their respective regulatory. standards are presented in Table B.
SVOCs detected were generally limited to naphthalene and 2-Methylnaphthalene. However,
SVOCs were infrequently detected and generally in the low ( < 1 OOppb) range. Metals did not frequently
exceed background levels and, with the exception of one sample, were not detected or detected at
concentrations in compliance with existing drinking water standards.
Table B
Primary VOCs in Ground Water and Cleanup Standards
Ground Water Quality Drinking Water Clean-up
Concentration (ppb) Standards (ppb) Standards (ppb)
Contaminants Minimum Maximum State Federal
Benzene 2 720 1 5 1
1.2- Dichloroethane 1 9 0.5 5 0.5
Ethylbenzene 1 150 680 700 680
Methylene chloride 6.9 56 40* 5** 5
Toluene 3 110 100* 1,000 100
*State Action Leve/ITBC
**Proposed MCLlTBC
There arecwrently two areas ofVOC ground water contamination; one beneath the former MWP
and one in the southwestern portion of the Site. The source of ground water contamination beneath the
MWP is likely to have come from the refinery wastes in the MWP. The ground water contamination
plume in the southern portion of the Site is likely to derive its source from suspected refinery waste pits
located in the southern portion of the Site. However, the southern plume may also have been connected
with sources in the nonhem portion of the facility given the high historical contaminant concentrations
beneath the MWP. Since the removal of the refinery wastes in the MWP, concentrations of these
contaminants in ground water have decreased.
A recent contour map of the ground water contamination plumes is presented in Figure 3. This
presents ground water concentration contours for benzene in Aquifer #1 as described in the Site
hydrology section.
Texaco sampled private production wells within a one half mile radius of the Site during the
12
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LEGCHP
ESTIMATED BOUNDARIES OF REMEDIATION
ACTION AREAS CBASED DN 10 ppb BENZENE
CONTOURS OF SECOND, THIRD AND FOURTH
QUARTER 1991 GRQUNDVATER MONITORING
SAMPLE DATA).
NOT TO SCALE
13
FIGURE 3
DEFINITION OF ACTION AREAS
TEXACO F1LLMORE SITE
-------
Remedial Investigation. Sample results indicate that no contaminants were deteCted.
D.
SCREENING INVESTIGATIONS
A soil-gas survey was conducted. No statistical cOITelation was found to exist between soil-gas
survey results and smface soil. However, subsmface soil data from the area of high soil gas concentrations
indicate TPH, TIC and VOCs concentrations in the pans per million. However, limited TCLP data does
not indicate significant leachable VOCs. It is unclear whether soil gas data indicates a potential subsurface
source of leachable contaminants.
Stream sediment and surface water samples were collected from Pole Creek flood conn-ol
channel and analyzed during the RI. Four sediment samples were collected, two upstream from the Site
and two downstream. Eleven water quality samples were collected from seven sampling locations along
Pole Creek. Samples were analyzed for metals, VOCs, SVOCs and EDB.
Stream sediment and surface water quality sampling results indicated low-levels of VOCs and
SVOCs some of which may have been associated with the Site. Metals were either not detected or
detected at similar concentrations in upstream samples, with the exception of a few compounds, one of
which was total chromium.
Upwind and downwind ambient air samples were collected over three consecutive days. Target
metal, VOCs and SVOCs in ambient air samples were either found to be below detectable limits or the
upwind and downwind concentrations were determined to be insignificantly different.
E.
DATA VALIDATION
Review and validation of sub-surface soils, surface soils, ground water, stream sediment and
surface water, as well as equipment rinsate samples and trip blanks followed EP A Functional Guidelines.
EP A's selected 10% of the laboratory data packages for full review. The review and validation
of analytical data followed EP A Functional Guidelines. A more detailed description of the data review
and validation activities and results are presented in the RI Repon and the Risk Assessment Report.
VI.
SUMMARY OF SITE RISKS
A Risk Assessment for the Site was completed by EP A in December 1991. The purpose of the
Risk Assessment was to evaluate the public health and environmental risks posed by VOCs and other
contaminants detected in the different media at the Site.
There were fony five (45) chemicals of potential concern detected at the Site, including VOCs,
SVOCs and metals. Metals in surface and subsurface soils samples were detected in concentrations
similar to concentrations detected in offsite background samples. The chemicals of potential concern are
presented in Table C.
Potentially exposed populations at and near the Site include CUITent on site workers, visitors or
trespassers at the Site, and nearby offsite workers and residents. As a conservative estimate and because
14
-------
Table C
Potential Compounds of Concern and Criteria for Selection
Texaco Fiilmore Site
Sheet 1 of 2
Compound
Acenaphtaene
Benzene
Benzo(a )antbracene
Benzo(a)pyrene
Benzo(b)0uoramhene
Benzoic Acid
Bis(2-«thylhexyl)phthalate
2-Butanone (MEK)
Carbon disulfide
Chlorobenzene
2-Chlorophenol
Chrysene
1,2-Dibromoethane
1,4-Dichlorobenzene
1.2-Dichloroethane
1,1 -Dichloroethylene
1 ,2-Dichloroethylene
Dimethyl phthalate
2,4-Dinitrotoluene
Etbylbenzene
2-Methylnapbthalene
Naphthalene
4-Nitrophenol
N-nitroso-di-n-propylamine
NJ^-Dimethyl acetamide
Phenanthrene
Phenol
Ton city
Values
a
b
a
a,b
a
a
a
b
b
b
a,b
a
' a
b
a
a
b
_
a
Toxicity
Concerns
c
c
c
c
.
Other
Factors
d
d
d
-
d
15
-------
., ~
Table. C (continued)
Potential Compounds or CoDcern aDd Criteria for Selection
Texaco FWmore Site
Sheet 2 or 2
Toxicity ToDdty Other
Compound Values Cooc:erns Factors
.
Pyrene a
Styrene a.b
Toluene a
1,2,4- TrichJorobenzene a
1.1.1- Trichloroethane 8
1.1.2.,2- Tetracl1loroethane b
Trich1oroetbylene b
Trichlorotrifluoroethane - - d
Vinyl acetate a
Xylenes. total a
Arsenic b
Barium a
Cadmium a.b
Chromium b
Copper a
Lead e
N ickel a
Vanadium a
-Has a Reference Dose (RID) (oral or inhalation) (as defined in Chapter 4, Toxicity Assessment)
~ a CaDcer Slope FaCtor (CSF) (oral or inhalation)
CPotentiaJ carcinogenicity
dFrequency of occunence or site history
16
-------
residential development is located immediately adjacent to the Site, risks for the Texaco Site have been
evaluated assuming a future residential exposure scenario.
Potential exposure pathways identified in the Risk Assessment included ingestion of ground
water, inhalation of VOCs from ground water, and direct contact with surface site soil. Screening level
evaluations were also performed for ingestion of surface water, inhalation ofVOCs in surface water, in-
gestion of stream sediment, and inhalation of ambient air. In addition, worker exposure to soil gas con-
taminants while trenching onsite was also a screening level evaluation. The exposure pathways are
summarized in Table D.
Toxicity values for the chemicals of concern are presented in Table E.
The excess lifetime cancer risks assuming residential use of contaminated ground water
(ingestion and inhalation) located at the Site, is estimated at 6x 10-5. The major contributorto this risk was
benzene with an estimated cancer risk of 5xl0-s. Although the risk associated with ground water
ingestion and inhalation is within the range generally considered to be acceptable by EP A [104 to 10-6]
pursuant to the National Contingency Plan, 40 C.F.R. See 300.430(e)(2)(1)(A)(2), benzene and other
known carcinogens are present in the ground water at levels that significantly exceed the federal and
California drinking water standards for those chemicals.
Drinking water (chemical-specific) standards are health-based levels and may be used to
determine whether an exposure is associated with an unacceptable risk to human health. To detennine
whether remediation is warranted at a site, EP A considers the results of the baseline risk assessment and
compares site concentrations to chemical-specific standards to assess whether there is an unacceptable
risk to human health or the environment (see OSWER Directive 9355.0-3.0,pg.4, April 22, 1991). EPA
has determined that the ground water contamination at this Site poses an unacceptable risk to human
health because ground water at the Site is a potential source of drinking water and contains carcinogens
that exceed federal and state drinking water standards.
The total estimated hazard index for non-carcinogens in the ground water, based on a child
exposure scenario, was 5.0. The hazard index is a measure of the chemical-specific noncarcinogen risk.
A hazard index of one (1.0) or more indicates a potential concern. Arsenic and cadmium in the ground
water were the major contributors to the hazard index. It should be noted, however, that the
concentrations of both of these compounds in the ground water are believed to be at naturally occuning
levels and are in compliance with existing standards for drinking water. Therefore, EP A is not requiring
any remediation of metals in the ground water. The risk calculation for ground water is summarized in
TableF.
The estimated excess lifetime cancer risk for ingestion of surface soils assuming future onsite
residential use is 4x 10-5. The major contributor to this surface soil risk was chrysene with an estimated
excess lifetime cancer risk of lXI0-5. Three additional chemicals, n-nitro-sodi-propylamine,
benzo(a)pyrene, and benzo(a)flouranthene had excess lifetime cancer risks within EP A's acceptable risk
range of 104 and 10-6. The total estimated hazard index for non-carcinogenic effects due tosoiI ingestion
was .005. This risk calculation is summarized in Table G.
Risk estimates were conducted by EP A for exposure to ambient air, stream sediment, surface
. water, and soil gas to detennine where other possible sources of risk might be located. Evaluations were
17
-------
Table D
Kxposnrc Scenarios and Assumptions
Baseline Risk Assessment
Texnco Klllmore Site
Sheet 1 of 2
Groundwater
00
Surface Water/
Sediments
Surface Soils
Major Exposure Pathways
Ingeslion; Inhalation/Dermal (in-home
use)
Dermal Contact; Ingeslion
Ingestion; Dermal Contact; Inhalation
(parliculates)
Kxposiire Scenarios
No known current use as
drinking water.
Private wells within 1/2 mile.
Conservative assumption or
future residential ingcslion of
groundwaier based on
importance of area groundwater
as eventual drinking water
source.
Stream often dry; exposures of
low frequency, duration, and
magnitude.
Channel is fenced; assume
occasional trespass by children.
Not a drinking water source.
Only consistent, current
exposures are to onsilc
personnel.
Conservative assumption is
future residential use.
Exposure Assumptions"
Adult: 70-kg body weight
2 liters per day ingestion
Child: 10-kg body weight
1 liter per day ingestion
30-year exposure duration (except
children)
350 days per year exposure frequency
Screening assessment to check detected
compounds.
Adult: 70-kg body weight
100 mg per day soil ingeslion
24-year exposure duration
Child: IS kg body weight
200 mg per day soil ingcslion
6-year exposure duration
Total exposure (Adult-f Child) = .10 yrs
.150 days per year exposure frequency
-------
Table D (continued)
Exposure Scenarios and Assumptions
Baseline Risk Assessment
Texaro Fillmore Site
Sheet 2 of 2
Major Exposure Pathway!)
Exposure Scenarios
Exposure Assumptions*
Subsurface
Soils
Current: Incidental Ingcstinn/Dcrmal
Contact for Onsitc Worker
Future: Incidental Ingcstion/Dermal
Contact for Residential or
Recreational Use
No direct exposure expected
unless soils arc excavated.
Exposures of low frequency,
duration, and magnitude.
Screening Assessment
Air
Inhalation
VO
Exposure to residents at
boundary represents realistic
potential scenario.
Adult: 70-kg body weight
20 nr/day inhalation
Child: 10-kg body weight
5 m /day inhalation
30-year exposure duration (except
children)
350 days per year exposure frequency
Soil-Gas
None
No direct exposure expected
except as compounds move into
ambient air.
Important as evidence of
continuing sources and site-
specificity of contaminants.
Conservative assumptions of
worker in trench.
Workers: 8 hours per day
20 nvVday Inhalation
25-year exposure duration
250 days per year exposure frequency
"From EPA. 1980. I9«9 and I990a
-------
K>
o
Compound
Accnapihcne
Benzene
Benzo(a)anthraccne
Benzo(a)pyrene
Benzn(n)nuoranthenc
Bcn/oic Acid
Bis(2 ethylhcxyl)
phlhalale
2-Bulannnc (MEK)
Carbon disulfidc
Chlorobcnzcnc
2-Chlorophcnol
Chryscne
1,2-Dibromoethane
(EDB)
1 ,4-Dichlnrnbcnzcne
1,2-Dichlorocihanc
1,1-Dichlnroclhylcnc
Table E
Selected Toxlclty Values for Compounds of Concern
Texaco Flllmore Site
Sheet 1 of 4
Oral
RfDdng/ke/d)
0.06
m~
--
--
«
4.0
0.02"
0.05
O.I
0.02
0.005
--
*
--
-.
o.ow
Inhalation
Rfl)(mg/lc£/d)
*«
.
--
--
--
--
V*
0.(W
o.on3c
0.005"
«
--
--
0.2C
«
--
WclRhl of
Evidence
--
A
B2
B2
B2
D
B2
*
D
--
D
B2
B2
#
B2
C
Oral
CSF(kj..d/mR)
--
0.029
II. 5b
11.5s
II. 5b
--
O.OI48
*»
--
*v
--
II. 5b
85"
0.024
0.091
0.6
Inhalation
UR(/ug/mJ)
--
8.3E-06
l.7E-03b
I.7E-3"
1.7-E-03b
**
--
--
-
-
l.75-03b
2.2E-04"
AA
2.6E-05
6E-05
Inhalation
CSF (ke-d/me)
*v
0.029
6.lb
6.1"
6.1"
--
--
* V
--
6.1"
0.76
-
0.091
1.2
-------
Table E (continued)
Selected Toxlclly Values for Compounds of Concern
Texaco Hllmore Site
Sheet 2 of 4
Compound
Cis 1,2-Dlchlorocihylene
trans
1,2-Dichloroethylcne
Oral
Rfn(me/kg/d)
0.01"
0.02
Inhalation
RflMniR/kR/d)
--
--
Weight of
Kvldence
D
.
Oral
CSF(kR.d/mR)
» v
Inhalation
llH(/»E/m3)
V*
-
Dimethyl phthalatc
2,4-Dinitroinluene
Elhylbcnzene
2-Melhylnaphlhalcnc
Naphthalene
4-Niirophennl
N-nitroso-di-n-
propylaminc
N,N -Dimethyl acctamidc
^^-^^^^^^i^
Phenanthrcne
Phenol *
1.0"
«
O.I
-
0.004"
* *
*
--
D
B2"
0.2K6BC
--
-
D
mf
*
w*
--
P^^BB^^HMMMH^BM^BHBBMI
0.6
*«
B«IMMm_MIM-BWT~MM*V
W
"
B2
*
^«BBH^H««l«H^HB«^iM
D
D
»*
0.68s
--
--
--
--
.
7.0
VMB^H«^i^^MM^WHV^MHtf^M>^M
A*
--
-
-
--
--
.MVBBWMta
"
Pyrcnc
0.03"
--
»
Inhalation
CSK (kR-d/mj.)
**
--
w
V*
--
-
"
*4
--
V4^mvM^kVi^i^H^^B^A«^^iA*«^AMfl^B^^
-
--
-------
M
Compound
Slyrcne
Toluene
Table E(continued)
Selected Toxlclfy Values for Compounds of Concern
Texnco Flllmore Site
Sheet 3 of 4
Oral
Rn>(mg/kf!/d)
0.2
0.2
Inhnlalion
Kn>(mg/ke/<1)
--
0.572C
Weight of
Kvidence
B2
D
Oral
CSF(kK-d/mf»)
0.0V
--
Inhalation
UR^uK/m1)
5.7E-078
--
Inhalation
CSF (M-d/mR)
0.002"
«
1 . 1 , 1 -Trichlomet hane
1,1,2.2-
Tcirachloroeihane
Trichloroclhylene
I.U-Trlchloro- 1.2,2-
Iriduoroelhane
Vinyl acetate
Xylenes. total
0.09
--
«
30
1.0"
2
O..V
--
--
7.7C
o.osr
0.
-------
Ta"Ie E (continued)
Selected Tnxldty Value!; fnr Cnmpound!J or Concern
Texaco "'lIImore Site
Sheet 4 Qr 4
Compound 0...1 Inhola"on Wel~ht nr Oral Inhll.tlon Inh.latlon
, Rm(mWlcWd) Rm(mWkWd) ":.Idence CSF(~-d/m~) UR(/uglm]) CSF (~-dJm~)
Lead -- -- 82 eo -. --
Nickel 0.02 -- -. -- .- --
Vanadium 0.007 -- " -- -- -.
N
W
Notes:
Source of Toxicity Values = IRIS 1991, unlc.'is noted.
8From HEAST, Annual FYI991
Oral RID = Oral Reference Dme
Inh RID :: Inhalation Reference Dose
Oral CSF = Oral Cancer Slope Factor
. Inh UR :: 'Inhalation Unit Risk
Inh CSF :: Inhalation Cancer Slope Faclor
CA Weight.of-Evidence Classifications:
A Human carcinogen
8 I Proh~hle human carcinogen, limited human dala
82 Prohahle human carcinogen, adequale animal evidence and
inadequale or no human dala
C Possihle human carcinogen
D Not classified as to human carcinogenicity
.... = Not avallahle or not applicahle .
'Toxicity a5.'iumed equal 10 hcnlo(a)pyrene, Based on U.S. EPA policy (Memo from Pei-Fung HurstlU.S. EPA Coordinator,
Superfund Technology Supf'C)rt center, tn Dana DavnlilU.S. EPA Region IX, Septemher IR, 1990.
c8ackcalculatcd from HEAST value in mg/m:\ using 20 m:\ inhalalion rale and 70 kg hody weight.
dUnil risk or SE.OS (,.tg/L) proposed (IRIS, Fehruary, 1991).
cWaler .
'Food
.
-------
-- --
based on conservative exposure assumptions using the highest concentration detected for each contami-
nant. Evaluations for ambient air, stream sediment, and surface water are based on a future onsite resi-
dential scenario. Evaluations for soil gas were based on the scenario of a worker excavating onsite soils.
The estimated excess lifetime cancer risk due to inhalation of chemicals detected in the ambient
air was 4x 10..5. The estimated hazard index for this pathway is .08. The estimated excess lifetime cancer
risk due to ingestion and inhalation of chemicals detected in surface water was 5x 1 0-6, while the risk due
to ingestion of chemicals detected in stream sediment was 2x 1 0-6. The hazard indices for both scenarios
were less than one. The risks for both scenarios are within EP A's acceptable risk range of 1 (k and 10..
6.
The estimated excess lifetime cancer risk for worker exposure to soil gas while trenching was
4x 1 0..3. This initial onsite worker calculation was a conservative estimate. A more realistic recalculation
would likely fall within the EP A acceptable riskrange. However, additional characterization of soil gases
is required.
ENVIRONMENTAL RISK
In the qualitative environmental assessment portion of the Risk Assessment, information was
collected regarding the sensitive species and habitats in the area. Nine birds and seven mammals were
identified as special status species potentially occurring in the vicinity of the Site. Potential exposure
pathways include direct contact with detected chemicals in surface soils, surface water, and creek
sediment
Pole Creek flows into the Pole Creek Flood Control Channel along the western border of the Site
and eventually to the Santa Clara River. Chemical concentrations detected in Pole Creek were compared
to regulatory criteria for the protection of freshwater aquatic life. All chemicals with criteria were detected
at concentrations below the corresponding criteria for the protection of aquatic species.
SUMMARY
Releases of hazardous substances from the Site have resulted in the contamination of ground
water presenting an imminent and substantial endangerment to public health, welfare or the environment
if the releases from the Site are not addressed by implementing the remedial response action selected in
this ROD. Interim removal oftherefmery wastes in the MWP and other areas has significantly reduced
Site risks. However, ground water contamination beneath the Site still exceeds drinking water standards
and requires remedial action.
VTI.
DESCRIPTION OF ALTERNATIVES
This section will describe seven alternatives that EP A has evaluated in selecting the final cleanup
plan for the Site. The seven alternatives were evaluated and compared to the nine criteria required by
the NCP (40 CFR Sec. 300.430(e)(9» in the Feasibility Study. The nine criteria are: overall protection
of human health and the environment; compliance with applicable or relevant and appropriate require-
ments (ARARS); long-term effectiveness and permanence; reduction of toxicity, mobility, or volume
through treatment; shon term effectiveness; implementation; cost; state acceptance; and community
I
j
24
-------
N
\.11
Tahle f
RI!'ik Char8rterlzatlon for Groundwater
"~.aco Fillmore Site
"~lor2
On!ilte Reliidential Scenario Child ReII"ntlal Sftnarlo
F.ue!l!l Ufetlme NOIKard~nlc lIal8n1
(:Rncer RI!lk Quotient"
Groundwater
Concentntlon(b)
Compound(.) (mWl) In~!ltlon Inhalation TOTAl. I~tlon Inhalation TOTAl.
Oen7.ene (A) ~_.. -. 0.071 2.4E-0,5c 2.4E-05 4.RE-05 -- -- eo
Carlton disutnde 0.11032 -- -- -- 0.0001 0.10 0.10
Chlorof)cnzene 0.001 u eo -- 0.11048 0.019 0.024
1.2-0ichloroclhane (B2) 0.11021 2.2E-06 2.2E-06 4.4E-06 -- eo --
Elhylbenlene (0) 0.01 -- -- -- 0.01 0.0034 0.013
2-Bulanone (MEK) (D) 0.018 -- u -- 0.034 0.019 0.053
Naphlhalene 0.011 -- u -- 0.26 .- 0.26
2-Melhylnaphlhalene 0.(1073 u -- -- -- .. ..
1.I.2.2-TetrBchloroelhane (C) 0.001 2.3E-fW) 2.3E-06 4.6E-06 -- -- -.
Toluene (0) 0.015 -- -- .. 0.0072 0.002S 0.11097
Xylenes (D) 0.01 " .- " 0.00048 0.011 0.011
Am:nic (A) 0.018 -- NC u 1.7 NC 1.1
Barium 0.324 -- NC -- 0.44 NC 0.44
.
Cadmium (0 I) 0.11048 -- NC -- 0.92 NC 0.92
Chromium 0.015 u NC .. 0.0014 NC 0.(1014
"..
-------
N
0\
Tahle F (continued)
RI!ik Chal'1Kterizalion for Groundwater
TexRco 1'lIImore Site
'.2012
On!iUe Residential Srenarto Child Residential Sftnarlo
.:XCe!iS Urellme NOIK'an:1n.nlc lIal8n1
C.ncer Risk Qootlentll
Groundwater
COnfentratlont')
C08Ipoond(8) (mwl) In~tlon InhalRtion TOTAl. lnantton Inhalatton TOTAl.
Chromium VI 0.02 .. NC -. 0.38 NC 0.38
Carper 0.022 -- NC -- -- NC --
Lead (82) 0.0029 -- NC -- .. NC --
Nickel 0.04 -- NC .. 0.19 NC 0.19
Vanadium 0.032 -- NC .. 0.44 NC 0.44
.'
TOTAI_" :m.U5 :m-U5 6E-05 4.4 0.2' 5
(II)Lellcrs In parcothC5C5 are carcinogenic weight-of-evidence da~~irIcatinns.
(tt>9S% upper oonOdenoo limit of the mean or the maximum detected value, whichever i~ luwer (from Table 1-3).
(c:>9.7E-OS :I 9.7 I 10.5
--No toxicity value available.
NC := Not calculated
-------
. Table G
Risk Characterization' for Surface SoDs
Texaco F&llmore Site
Excess Wetime NoDC8l'CiDoeenic
Cone" Cancer Risk Hazard Quotients
Compound Cl&1"k&) ID2estion Chil~tion
Acenaphtbene 1169 - 2.49E-04
Benzene (A)~ 10.9 4.9SE-I0 -
Benzo(a)anthracene (B2) 61 1.1Q.06 -
Benzo(a)pyrene (B2) 250 4.soE-06 -
Benzo(b)Ouoranthene (B2) 93 1.62E-06 -
Bis(2-ethylhexyl)phtbalate (B2) 890 1.9SE-08 5.69E-04
2-Butanone (MEK) (D) 19.6 - 5.01E-06
Chlorobenz.ene (D) 7.61 " 4.86E-06
-
2-Chloropbenol 1263 - 3.23E-03
Chrysene (B2) 800 1.44E-05 -
l,2-Dibromoethane (B2) 3.22 4.28E-07 -
1,4-Dichlorobenzene 1162 4.31£-08 -
1,I-Dicbloroethylene 6.45 6.06E-09 9. 16E-06
2,4-Dinitrotoluene (B2) 1181 1.26E-06 -
Ethylbenzene (D) 4.67 - 5.97E-07
4-Nitrophenol 5591 - -
N-nitrosodi-n-propyJamine (B2) 1178 1.29E-05 -
Phenanthrene (D) 110 - -
Pbenol (D) 1220 - 2.60E-05
Pyrene 1177 - 5.02E-04
Toluene (D)' 173 - 1.11E-05
1.1,I-Trichloroethane (D) 4.7 - 6.68E-07
Trichloroethylene (B2) 6.99 1.20E-I0 -
Vinyl acetate 15.3 - 1.96E-07 .
Xylenes (Total) (D) 9.69 - 6.19E-08
TOTAlS 4E-05 0.005
.
'Ninety-fIVe percent upper confidence limit on the mean ({rom Table 2-2).
bJ.,etten in parentheses IJ"C c:aTCinogenic weilht~r-evidence clas.silicatioDS.
27
...' .--
-------
acceptance. The nine criteria are described in more complete detail in Pan VITI of this decision document,
entitled SIJmmary of Comparative Analysis of Alternatives.
The focus of the Feasibility Study was the achievement of drinking water standards in ground
water. The aquifers at the Site are designated by the State of California as potential sources of drinking
water and therefore must be restored to drinking water quality standards. The federal and state drinking
water standards for the compounds of concern are presented in Table B. The alternatives described
below, except the no-action alternative, are designed to meet these standards in the aquifer over different
restoration time periods, employing different treattnent technologies.
Each alternative would require periodic ground water monitoring to determine the effectiveness
of the cleanup and to verify achievement of the cleanup standards. The specific ground water monitoring
program will be defmed more precisely during Remedial Design/Remedial Action.
A
ALTERNATIVE 1
The NCP requ!res that a no-action alternative be considered at every site. The no-action
alternative serves primaril~ a point of comparison to other alternatives. There are no costs associated
with this alternative. No activ~eattnent systems exist at the site and none would be implemented in this
alternative.
B.
ALTERNATIVE 2
Remedial Alternative 2 consists of continuing (l) existing resaictions to access to the Site by
maintaining perimeter fencing until the cleanup standards are achieved and (2) ground water monitoring
presently performed at the Site. However, no action would be taken to remove contamination from the
ground water or soils.
There would be a capital cost of $55,000 for this alternative. The annual operation and
maintenance costs for Alternative #2 would be $120,000. Net present value for this alternative would
range betWeen $500,000 and $1,500,000. Cleanup time frames are presented as a range to account for
the variable influence that natural degradation may have on the time it takes to achieve the cleanup
standards in groundwater.
C.
ALJERNA TIVE 3
Alternative 3 would involve continuing the activities described in Alternative 2 plus the
installation of caps or covers over the waste pit areas to inhibit leachate migration from the soils to ground
water. However, no action would be taken to remove the contaminants from the ground water or soils
or to prevent the migration of ground water contamination.
Capping the waste pit areas would involve importing native fill from.other locations at the Site,
combining the fill with clay, and covering the waste pit with this mixed material. Capping with a synthetic
cover would involve installing the cover over the area and capping it with imponed fill from other
locations at the Site. Both scenarios would involve final surface grading and revegatation to control
surface drainage.
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There would be a capital cost of $970,000 for this alternative which includes maintaining the
existing perimeter fencing and quanerly ground water monitoring. The annual operation and mainte-
nance costs for Alternative 3 would be approximately $140,000. Likely net present value would range
between $1,600,000 and $2,700,000.
D.
ALTERNATIVE 4
Remedial Alternative 4 includes: (1) continuing maintenance of perimeter fencing, (2) quanerly
ground water monitoring that is currently conducted at the Site and (3) a ground water extraction and
surface treatment system. No action would be taken to prevent or inhibit the migration of low levels of
leachable contaminants from the subsurface soils to the ground water under this alternative.
Under this alternative the ground water extraction system would consist of a set of recovery wells
strategically situated within both areas of ground water contamination. The placement and number of
wells will be determined by EP A once aquifer testing and ground water modeling has been completed.
Preliminary conceptual design work indicates that somewhere between four to seven extraction wells
may be required for the ground water system.
The extracted ground water will be treated at the surface using carbon adsorption. Carbon
adsorption was selected as the most cost effective and implementable treatment system in the Feasibil-
ity Study. Carbon adsorption is a physical process in which materials are transferred from the aqueous
phase to the surface of a solid (carbon), where they are concentrated. Granular activated carbon (GAC)
is the most common adsorbent used in water and waste water treatment. The internal pore structure
provides a large surface area for adsorption of different organic compounds.
The carbon after use needs to be replaced or regenerated. Regeneration and or replacement of
the carbon constitutes the majority of the operation costs associated with carbon adsorption. The specific
design of the GAC system will be determined during the remedial design phase. Spent carbon will be
thermally desttoyed or regenerated.
Treated ground water will be injected into the aquifer or reused in a beneficial manner such as
irrigation.
There would be a capital cost of $550,000 for this alternative. The annual operation and
maintenance costs for Altemative4 would be $240,000. Net present value for this alternative ranges from
$1,200,000 to $3,500,000.
E.
ALTERNATIVE 5
Remedial Alternative 5 would include an in-situ bioremediation system to cleanup ground water.
In-situ bio-remediation consists of enhancing environmental conditions in the subsurface where contami-
nants are present to optimize natural microbial metabolism of organic compounds. The conceptuaIlayout
of the system includes: (1) extraction of ground water from the areas with contaminated ground water,
(2) surface treatment of the extracted groundwater with activated carbon to removeresiduaI constituents,
(3) addition of oxygen and nutrients to the treated ground water; and (4) re-infiltration of the enhanced
water through the vadose zone soils to the ground water.
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The system would require the use of extraction wells, infiltration galleries, and injection wells.
Maintenance of the perimeter fencing and quarterly ground water monitoring would be continued under
this alternative.
Laboratory or field studies are usually required to determine biodegradation rates, oxygen and
nutrient requirements, and effects of different parameters such as pH and temperature on bio-
degradation. Once implemented, bio-remediation systems require significant operational effons to
monitor and maintain optimum conditions for microbial growth, and to prevent fouling or plugging that
may render the system ineffective. .
The total capital cost associated with this alternative is approximately $790,000. The annual
operation and maintenance costs are estimated at $300,000. The estimated net present value for this
alternative ranges betWeen $1,300,000 and $4,500,000, depending upon the rate of natural degradation
that may be occuning at the Site.
F.
ALlERNATNE 6
Alternative 6 consists of the ground water extraction and carbon treatment described in
Alternative 4, plus soil treatment by soil vapor extraction (S VE). Maintenance of the perimeter fence and
periodic ground water monitoring would be required. Treated ground water will be injected into the
aquifer or reused in a beneficial manner such as inigation.
The remedial action objective for SVE would be to remove the potential for continued ground
water contamination due to migration of contamination from the vadose zone. The criteria for the need
to conduct the SVE and the extent of such an action would be triggered by a residual distribution and mass
ofVOCs in the vadose zone that threatens to contaminate underlying ground water at levels exceeding
federal or State drinking water standards (Maximum Contaminant Levels, or MCLs) selected in this ROD.
The distribution and mass of residual VOCs would be evaluated at regular interVals throughout operation
and/or monitoring of the SVE system.
SVE removes contaminants in the vapor phase from pore spaces in the unsaturated zone by
drawing air through the subsurface. This is accomplished by installing and drawing a vacuum on vapor
recovery wells. The flow of air through the subsurface enhances the volatilization rate of contaminants.
Significant increases in the subsurface biological degradation of many compounds has also been
confirmed through the use of the SVE. Extracted soil vapor will be treated by vapor-phase carbon
adsorption or equivalent treatment method.
Prior to initiating the design of the SVE system, a one year subsurface study will be conducted.
Components of the study will include: (1) an assessment of soil parameters potentially influencing rates
of natural degradation in the sub-surface soil; (2) performance of additional field work to collect data on
soil vapors in target areas; (3) a calculation of sub-surface soils impact to ground water using "Designated
Level Methodology" or "V-Leach" or a similar analytical tool approved by EPA; and (4) collection of
additional ground water monitoring data. Values for soil, contaminant, and underlying saturated zone
parameters to be used in the application the analytical tool and the mixing zone calculations shall be those
selected by EP A. Following an analysis of the results of the one year subsurface study, EP A shall require
SVE for those areas that threaten to contaminate groundwater at levels above site cleanup standards.
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The total capital cost for this alternative is $1,075,000 or lower depending on whether an SVE is
included in the alternative following the one-year soil study. Annual O&M costs would be $480,000. Net
present value for the remedy would range from $2,300,000 to $7,000,000.
G.
ALTERNATIVE 7
Alternative 7 would consist of the in-situ ground water treatment system as described in
Alternative 5, plus soil treatment by SVE. The perimeter fencing would be maintained, and periodic
ground water monitoring would be continued. The in-situ soil bioremediation system would differ from
that described for Alternative 5 in that the ground water enhanced with oxygen and nutrients would be
reinjected into the subsmface only through the injection well rather than through infiltration galleries. The
.. SVE system would be similar to that described in Alternative 6.
The total estimated capital cost for this alternative is $1,270,000. Annual O&M costs, including
maintaining perimeter fencing and ground water monitoring, would be $540,000. The estimated net
present value for this alternative would range between $1,800,000 and $8,000,000.
vm SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
A.
PROTECfION OF HUMAN HEALTH AND 1HE ENVIRONMENT
Overall protection of human health and the environment addresses whether an alternative
provides adequate protection from exposure to contamination and describes how risks for the exposure
pathways are eliminated or reduced.
The no-action Alternative 1 would not provide any protection from exposure to ground water
contamination at the Site and there would be no reduction of Site risk. Alternatives 2 and 3 would not
actively eliminate or reduce risks posed by ground water contamination and could result in the
contamination spreading. Ground water monitoring would measure possible natural processes such as
degradation and anenuation, however, these processes are uncertain and do not provide as much
protection as provided by alternatives 4, 5, 6 and 7.
Alternative 4 and 6 through the use of engineering controls in the form of a ground water
extraction and treatment system would protect against the spread of contaminated ground water and
reduce the risk of exposure to contaminants in ground water by the treatment of contaminants in ground
water to the state or federal standard for drinking water, whichever is more stringent. Alternatives 5 and
7, would to the degree that they would be able to affect the full extent of ground water contamination
down to the cleanup standards, provide protection from the migration of contaminants equal to the level
provided by alternatives 4 and 6. However, in-situ systems are not as robust in capturing the full extent
of ground water contamination.
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B.
COMPUANCE WITIiARARS
Section 121(d) of the CERCLA, 42 D.S.C. ~9621(d), requires that remedial actions selected
under CERCLA attain a level or standard of control of the hazardous substances at a Site which complies
with "applicable or relevant and appropriate requirements" ("ARARS") of federal environmental laws
and more stringent state environmental and facility siting laws, that have ~n identified by the state in
a timely manner.
"Applicable" requirements are those cleanup standards, standards of control, and other substan-
tive requirements or limitations that have been promulgated under federal or state environmental and
facility siting laws that specifically address a hazardous substance, pollutant or contaminant, remedial
action or other circumstance at a particular CERCLA Site. "Relevant and appropriate" requirements are
cleanup Standards, standards of control and other substantive environmental protection requirements,
criteria, or limitations promulgated under federal or state law that, while not directly applicable, to a
hazardous substance, pollutant, contaminant, remedial action, location or other circumstance at a
CERCLA Site, address problems or situations sufficiently similar to those encountered at the particular
Site that their use is well suited to the particular Site. If an ARAR does not cover a particular situation,
or if an ARAR is determined to be insufficient to protect human health or the environment, non-
promulgated advisories or guidance (To Be Considered or TBCs) may be used in determining the
necessary cleanup level for protection of health or the environment.
There are three categories of ARARs or TBCs: (1) contaminant-specific, (2) action-specific and
(3) location-specific. Contaminant-specific ARARs and TBCs are limits on concentrations of specific
hazardous substances, pollutants or contaminants in the environment. Examples of this type of
requirement are drinking water standards and ambient waterquality criteria. Action-specific ARARs and
TBCs are restrictions that are triggered by a particular type of activity at a Site such as Resource
Conservation and Recovery Act regulations regarding hazardous waste treatment. storage or disposal.
The third type of ARARs or TBCs are restrictions on certain types of activities based on the location of
the Site. These include restrictions on activities in wetlands, floodplains and historic areas.
Contaminant-Specific ARARs and TBCs
A total of forty five (45) contaminants were identified for evaluation in the risk assessment
because they were detected at the Site. The risks from these contaminants were determined to be within
EPA's acceptable risk range for all exposure pathways for all contaminants. However, four of these
contaminants exceed their federal or state drinking water standards and therefore present an unnacept-
able risk to human health. .
The contaminant-specific ARARs for the Site are Federal and State of California drinking water
standards because the Site ground water is a potential source of drinking water. The NCP (40 C.F.R.
i300.430(f)(S» requires that remedial actions attain the Maximum Contaminant Level Goal (MCLGs)
established under the federal Safe Drinking Water Act that are set above zero for ground water that is a
current or potential source of drinking water. If a M CLG is set at zero or is not relevant and appropriate
under the circumstances, the Maximum Contaminant Level (MCL) established under the Safe Drinking
Water Act will be an ARAR. The MCLsand MCLGs for the constituents of concern are set forth in Table
B. EPA considers the proposed MCL for Methylene Chloride as the TBC because it is the most
protective standard.
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The State of California has also promulgated MCLs for the constituents of concern as shown in
Table B. The California MCLs are either equal to or more stringent than the federal MCLs and MCLGs
for the constituents of concern.
EP A also considered the California Department of Health Services drinking water action levels
(ALs) as TBCs. ALs are health-based chemical concentrations designed to limit public exposure to
substances that do not have state MCLs at this time. ALs are advisory standards that apply at the tap for
public water supplies. Toluene has a California AL.
EP A has selected the California AL as the ground water cleanup standard for toluene because the
federal MCLG for toluene is not as protective of ground water as the State AL. In addition, EP A has
selected the proposed federal MCL, as the cleanup standard for methylene chloride because that standard
is the most protective standard for the ground water. For the other contaminants, EP A has selected as the
cleanup standard for ground water the CU1Tent federal MCLs or federal MCLGs or state MCLs,
whichever is most stringent for the particular contaminant. Table B sets fonh the cleanup standards for
five contaminants.
All of the alternatives could possibly achieve the chemical-specific ARARs. However, the
ARARs would be achieved in varying time frames under the various alternatives. Alternatives 1 through
3 rely entirely on natural degradation of contamination and represent the alternatives least likely to
achieve ARARs. Alternatives 5 and 7 would rely on certain natural conditions to enhance the rate of
degradation, which are more difficult to control but would likely achieve the ARARs, particularly
Alternative 7. Alternatives 4 and 6 are also likely to achieve ARARs. Without site specific results from
implementation of each of the alternatives, it is very difficult to estimate any particular alternative's ability
to achieve a cleanup standard as low as 1 ppb, as in the case for benzene at this Site.
Action Specific ARARs and TBCs
Iniection of Treated Effluent into Aquifer
Alternatives 4, 5, 6 and 7 include ground water extraction and treatment, and possible injection
of treated effluent into the ground water. Effluent from the ground water treatment system that is injected
into the aquifer at the Site must meet the following ARARs: (1) the Los Angeles Regional Water Quality
Control Board's Water Quality Control Plan, which incorporates State Water Resources Control Board
(SWRCB) Resolution No. 68-16 "Statement of Policy with Respect to Maintaining High Quality of
Waters in California," (2) Section 3020 of the Resource Conservation and Recovery Act, (3) the
California Safe Drinking Water Act (Proposition 65), and (4) the federalUnderground Injection Control
(UlC) Program for class V wells set fanh in 40 C.F.R. Part 144.
SWRCB Resolution #68-16 requires maintenance of existing State water quality unless it is
demonstrated that a change will benefit the people of California, will not unreasonably affect present or
potential uses, and will not result in water quality less than that prescribed by other State policies.
Section 3020 of the Resource Conservation and Recovery Act prohibits disposal of hazardous
waste above or into a fonnation which contains a source of drinking water. This prohibition does not apply
to injection of treated contaminated ground water into an aquifer if (1) such injection is pan of a response
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action under CERCLA, (2) the contaminated ground water is treated to substantially reduce hazardous
substances prior to such injection, and (3) the response action will upon completion be adequate to protect
human health and the environment.
Proposition 65 prohibits the discharge of chemicals known to the State to cause cancer or repro-
ductive toxicity into ground water or surface water drinking water sources or onto land which may pass
into a drinking water source. Benzene, and other constitUents of concern at the Site, have been identified
as carcinogens by the State of California.
The federal Underground Injection Control Program requires that injection wells such as those
that would be located at the Site not, (I) cause a violation of primary MCLs in the receiving aquifer, and
(2) not adversely affect the health of persons (40 C.P.R. Sec. 144.12). .
To meet these ARARs, any treated ground water that is reinjected at the Site will be treated to
concentrations below federal MCLs/MCLGs or State MCLs, whichever is more stringent, for all the
constituents of concern, except toluene, for which the ground water must be treated to below the State
AL and methylene chloride for which the ground water must be treated to below the proposed federal
MCL.
Reuse of Treated Ground Water
Alternatives 4 and 6 include ground water extraction and treatment that results in treated effluent
that could be reused in a beneficial manner. The action-specific ARARs or TBCs that are applicable to
the use of treated ground water from the Site in a public drinking water system are (l)the State and federal
drinking water standards, (2) the SWRCB 's Resolution #68-16 and (3) California's Proposition 65. To
meet these ARARs, any treated ground water that is delivered from the Site to public water supplies must
be treated to concentrations below the State or federal MCLs, whichever is more stringent for the
contaminants of concern except the ground water will have to be treated to below the California AL for
toluene.
The three requirements listed above have been identified by EP A as TBCs if the ground water
extracted from the Site is provided at the Site for use as non-potable water. EP A has determined that this
is necessary to protect human health and the environment from the use of inadequately treated ground
water. Accordingly, the ground water must be treated to below the State or Federal MCLs, whichever
is more stringent for the contaminants of concern before reuse of any type.
Carbon AdsorJ>tion
Use of activated carbon for treatment of organics under alternatives 4,5, 6, and 7 could trigger
Resource Conservation and Recovery Act (RCRA) and California Hazardous Waste Control Act
(HWCA) requirements for hazardous waste generators if the spent carbon contains sufficient quantities
of hazardous constituents that cause the spent carbon to be classified as a characteristic hazardous waste
underRCRAorHWCA. If the spent carbon is a characteristic hazardous waste underRCRAand HWCA,
the ARARs for handling such waste are the requirements for hazardous waste generators set fonh in 40
C.F.R. Part 262 and Part 268 and HWCA regulations at Title 22 Sections 66470-66515 and Title 22
Chapter 30, Article 15. Storage of contaminated carbon that is classified as a characteristic hazardous
waste for more than 90 days ttiggers the hazardous waste storage requirements set fonh in 40 C.F .R. Part
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264 and HWCA Title 22 Sections 67180-67194.
Soil Vapor Extraction
Alternatives 6 and 7 include soil vaporexttaction which may result in the release of pollutants into
the air. In California, the authority to regulate stationary sources has been delegated to local air quality
management districts. The Site is located within the jurisdiction of the Ventura County Air Pollution
Control DistriCt (APCD). Accordingly, action-specific ARARs for emmissions from a soil vapor
extraction system at the site include the substantive requirement of APCDs Rules 26.2 (New Source
Review) if the emmissions are determied to be of the type and quantity to be covered by these rules.
Location-Specific ARARs and TBCs
EP A has not identified any location-specific ARARs or TBCs for the Site.
C.
LONG-TERM EFFECfIVENESS AND PERMANENCE
Long-term effectiveness and permanence refers to the ability of a remedy to maintain reliable
protection of human health and the environment over time. This criterion includes the consideration of
residual risk and the adequacy and reliability of controls after implementation of the remedy. The residual
risk, or risk remaining after completion of the cleanup, is the same for all of the alternatives because the
cleanup standards are the same for all alternatives. The residual risk for benzene at the cleanup standard
of 1 ppb is approximately lxlO.{). Other contaminants are present at concentrations that would adequately
be reduced during the cleanup of benzene to 1 ppb. These other residual contaminants would not
contribute additional significant residual risk.
Long-term effectiveness is also measured by the adequacy and reliability of controls. Alternatives
4 through 7 would have the greatest ability to maintain reliable protection of human health and the
environment over time because active measures are used under these alternatives to control the spread
of contamination and to restore the aquifer. All alternatives include ground water monitoring. Alternatives
2 and 3 have no hydraulic controls, and therefore provide the least amount of control over ground water
when compared with alternatives 4 through 7. Alternatives 1 through 3 might allow contamination to
spread to clean zones within the aquifers in the Fillmore basin.
D.
REDUCTION OF TOXICITY, MOBILITY, OR VOLUME TIlROUGH TREATMENT
Reduction of toxicity, mobility, or volume through treatment refers to the preference for a remedy
that uses treatment to reduce health hazards, contaminant migration, or the quantity of contaminants at the
Site.
Alternatives 1,2 and 3 do not employ treatment and therefore provide no measurable beneficial
effeet for this criteria when compared with the other alternatives. Alternative 4 would reduce
contaminants by extracting them from the ground water and destroying them through the regeneration
of the spent carbon. Alternative 5 would provide a slightly higher degree of treatment by enhancing
degradation occurring in soils, and not relying upon the rate of contaminant removal via extraction wells.
Alternative 6 would provide an even greater degree of treatment than alternative 5 by simultaneously
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effecting a greater reduction of contaminants in soils, since S VB will remove contaminants and stimulate
biodegradation in the vadose zone. Alternative 7 through the use of in-situ bie-remediation would be
likely to provide treatment equal to Alternative 6, depending on the enhanced rate of degradation that may
be achieved in ground water. However, it is difficult to predict how well biodegradation would work due
to the variability of natural conditions.
E.
SHORT -TERM EFFECTIVENESS
Shan-term effectiveness refers to the period of time needed to complete the remedy and to
prevent adverse impacts on human health and the environment that may be posed during construction and
-- implementation of the remedy. Since a complete health and safety plan would be completed prior to the
implementation of the remedies, shon-term adverse impacts during construction of the remedies would
minimized. The alternatives are estimated to achieve the cleanup standards within varying time periods.
Alternatives 1 and 2 would provide the slowest anticipated cleanup because they rely on natural
degradation of contamination to accomplish the cleanup. Alternative 3, which includes a soil cover, may
prevent the future leaching of contaminants from soil to ground water which would achieve a slightly
faster clean-up when compared with Alternative 1 and 2. Alternatives 4, 5, 6 and 7, by actively conttolling
migration of contaminants and restoring the ground water, would achieve the cleanup standard in the
shortest period of time. .
It is difficult to estimate with accuracy the degree to which natural degradation in ground water
may be enhanced under Alternatives 5 and 7 (bio-degradation) to provide a faster cleanup than under
Alternatives 4 and 6 (extraction and treatment). Similarly, it is difficult to predict the degree to which
natural rates of degradation in the soils may be enhanced through infiltration of oxygen and nunient
enhanced water (Alternative 5) in comparison with SVE (Alternatives 6 and 7). However, SVE
(Alternative 6), as a proven and reliable treatment technology, is more likely to remove contaminants from
the vadose zone soil and stimulate bie-degradation resulting in a faster cleanup of soils and ultimately of
ground water.
F.
IMPLEMENTABll..ITY
Implementability refers to the technical and administrative feasibility of a remedy, including the
availability of materials and services needed to implement the selected remedy. It also includes
coordination of Federal, State and local governments in cleanup of the Site.
All of the alternatives are implementable. Technically and administratively, Alternatives I and 2
are the easiest alternatives to implement because they require little or no work. The most difficult
alternatives to implement are 5 and 7 as they require significant technical oversight in the balancing of
oxygen and nutrient levels to optimize the stimulation of degradation. Variables and uncertainties for
Alternatives 5 and 7 could lead to delays. Alternatives 3,4 and 6 would employ reliable technologies that
are relatively easy to implement.
G.
COST
This criteria examines the estimated costs for each remedial alternative. For comparison, capital
costs and annual O&M costs are used to calculate a total net present worth cost for each alternative.
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Alternative 1 is not discussed in detail in this section because it requires no-action and therefore no costs.
Alternative 2 would not require significant capital costs and the annual O&M costs would be
limited to ground water monitoring of approximately $120,000. Altemative2 has a total net present value
of $1.5 million after 30 years of operation.
Alternative 3 has an estimated capital cost of$970,OOOplus annual O&M costs to monitor ground
water equal to $140,000. The total net present value for alternative 3 is $2.7 million assuming 30 years
of operation.
Alternative 4 has an estilrnlt~ capital cost of $550,000 plus an annual O&M cost of $240,000. The
total net present value for alternative 4 is $3.5 million assuming 30 years of operation.
Alternative 5 has an estimatro capital cost of $790,000 plus an annual O&M cost of $300,000. The
total net present value for alternative 5 is $4.5 million assuming 30 years of operation.
Alternative 6 has an estimated capital cost of$1 ,07 5,000 plus an O&M costof$480,000. The total
net present value for alternative 6 is $7.0 million assuming 30 years of operation.
Alternative 7 has an estimated capital cost of $1,270,000 plus an annual O&M cost of $540,000.
The total net present value for alternative 7 is $8.0 million assuming 30 years of operation.
H.
STATE ACCEPTANCE
State acceptance indicates whether, based a State's review of the RIlFS and Proposed Plan, the
state in which the Site is located agrees with the preferred alternative.
EP A has involved the Los Angeles Office of California EP A Department of Toxic Substances
Control in the development of the RIlFS and the selection of the remedy. The Department of Toxic
Substances Control, on behalf of the State of California, has stated a preference, and concurs with EP A,
on the selection of Alternative 6 as the preferred remedy.
L
COMMUNITY ACCEPTANCE
Community acceptance indicates the public suppon of a given alternative.
EP A has solicited input from the community on the alternatives evaluated for the Site. The public,
with the exception of one letter endorsing the no-action alternative, has supponed the preferred
alternative. A response to these comments is provided in Attachment B.
IX.
SELECTED REMEDY
EP A has selected Alternative 6 as the remedy for the Pacific Coast Pipeline Site. The selected
remedy for contaminated ground wa~er at the Pacific Coast Pipeline Site consists of:
1)
Design, construction and operation of a ground water extraction and treattneot system
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to treat extracted ground water to levels that meet the cleanup standards set fonh in this ROD;
2) Discharge of treated ground water to the aquifer at the Site by injection or provision of the
treated ground water to beneficial users of the treated ground water;
3) Soil Vapor Extraction for those areas that threaten to contaminate ground water at levels
above Site cleanup standards following a one year subsurface study as described on page 30 of this ROD;
4) Ground water monitoring to demonstrate that the extraction system is effectively
capturing the contaminant plume and ultimately, to demonstrate achievement of the cleanup standards
throughout the aquifer; and
5)
Maintenance of perimeter fencing at the Site until cleanup standards are met.
Implementation of this remedy will prevent the spread of ground water contamination and reduce
the principal risk of exposure to contaminated ground water. The ground water extraction and treatment
system will operate until the cleanup standards are achieved. Because this remedy will not result in
hazardous substances remaining on the site above health-based levels, the five-year review will not apply
to this action. The selected remedy will undergo periodic performance evaluations at a frequency to be
determined in the Remedial Design Workplan.
The decision to select Alternative 6 as the remedy is based on a comparative analysis of the
alternatives presented above and provides the best balance of trade-offs with respect to the nine
evaluation criteria.
The ground water extraction system will operate until the cleanup standards are achieved and
continuously maintained throughout the aquifer; EP A will periodically re-evaluate the remedy at a rate
to be determined during the Remedial Design. It may become apparent, during implementation or
operation of the ground water extraction system, that contaminant levels have ceased to decline and are
remaining constant at levels higher than the cleanup standards. Based on performance data, operation
of the extraction system will be adjusted as warranted if so determined by EP A during the periodic EP A
evaluations.
GROUND WATER EXTRACI10N AND TREATMENT SYSTEM
Ground water shall be extracted using multiple extraction wells, the exact location, number, and
pumping rates shall be detennined during the design of the ground water recovery system. Recovered
ground water shall be treated using an on site treatment system. Ground water shall be treated using
activated carbon treatment. Final flow rates and treatment unit dimensions will be determined during the
remedial design. The treated effluent shall be reused for beneficial purposes or injected back into the
subsurface through injection wells constructed as a part of the remedial action.
CLEANUP STANDARDS FOR GROUNDWATER
The cleanup standards for the ground water are set fonh in Table B of Section II of the Decision
Summary. The selected remedy, when complete, will have reduced the concentrations of contaminantS
in ground water to below the cleanup standards thereby satisfying the chemical-specific ARARs (Federal
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or State MCLs, whichever is more stringent and the TBCs State Action Level for toluene) for the Site.
In addition, during remediation, this remedy will meet action-specific ARARs for discharging the treated
water into the aquifer by injection or for providing treated water to beneficial users of the water. For any
waste carbon that is generated during the ground water or soil vapor treatment by activated carbon, the
applicable Resource Conservation and Recovery Act and more stringent California Hazardous Waste
Control ACt requirements will be met
GROUND WA1ER REMEDY IMPLEMENTATION
An operation and maintenance plan for the ground water extraCtion and treatment system shall be
required. The performance of the ground water extraction and treatment system shall be carefully
monitored on a regular basis and the system may be modified, as warranted by the perfonnance data
colleeted during operation and at the discretion of EP A.
A long-term ground water monitoring program shall be implemented to evaluate the effective-
ness of the ground water pumping and treatment system and to demonstrate achievement of cleanup
standards. Additional monitoring wells shall be installed if necessary.
x.
STATUTORY DETERN.UNATIONS
The selected remedy is protective of human health and the environment as required by section
121 ofCERCLA. The selected remedial action, when complete, shall comply with applicable or relevant
and appropriate environmental standards established under Federal and State environmental laws, unless
a statutory waiver is granted. The selected remedy is cost-effective, uses permanent treatment
technologies to the maximum extent practicable and includes treatment as a principal element. The
following sections discuss how the selected remedy for the Pacific Coast Pipeline Site meets these
statutory requirements.
PROTECI10N OF PUBUC HEALTH AND THE ENVIRONMENT
Attainment of clean-up standards will assure that the levels of the contaminants of concern in the
ground water at the site will not exceed health-based drinking water standards. Alternative 6 uses
engineering controls in the form of a ground water extraction treatment system to remove contaminated
ground water from the aquifer where it could be used for consumption. The extraction of VQC-
contaminated ground water will significantly reduce the threat of exposure to residents. The implemen-
tation of this remedy will not create any shon-term risks nor any negative cross-media impacts.
A TIAINMENTOF ARARS
All ARARS will be met by the selected remedy. The selected remedy will achieve compliance
with chemical-specific ARARs by treating ground water to concentrations at or below the chemical-
specific cleanup standards. Action-specific ARARs will be met for the selected discharge option and for
the SVE system. There are no location-specific ARARs.
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COST-EFFECTIVENESS
EPA believes the selected remedy is cost-effective and treats the contaminated ground water
within a reasonable period of time. The selected remedy fulfills the nine criteria of the NCP and provides
overall effectiveness in relation to its cost.
Alternative 6 has a capital cost of approximately $1 ,075,0C'IJ and an approximate annual O&M cost
of$480,OOO. The total net present value is between $2.3 and $7.0 million depending on the time required
to cleanup the Site.
USE OF PERMANENT SOLUTIONS AND ALTEItNA TIVE TREATMENTTECHNOLOOIES OR
RESOURCE RECOVERY TECHNOLOOIES TO TIffi MAXIMUM EXTENT PRACIlCABLE
The selected remedy represents the maximum extent to which permanent solutions and tteatment
technologies can be used in a cost-effective manner for the Pacific Coast Pipeline Site. Of those
alternatives that are protective of human health and the environment and comply with ARARs, EP A has
determined that the selected remedy provides the best balance of long-tenn effectiveness and perma-
nence; reduction oftoxicity, mobility and volume through treatment; shon-tenn effectiveness; imple-
mentability, and cost effectiveness. The selected remedy has also been accepted by the state and
community .
PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
Contaminants of concern in the ground water will be extracted, and treated. The treatment will
occur in the carbon adsorption treatment system to remove and concentrate the contaminants. Captured
contaminants will be destroyed when the carbon is regenerated or replaced and thermally destroyed.
Therefore, this remedy satisfies the statutory preference for remedies that employ treatment which
pennanently and significantly reduces toxicity, mobility or volume of hazardous substances as a principal
element
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