United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R09-93/094
August 1993
c/EPA Superfund
Record of Decision:
Lorentz Barrel & Drum, CA
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50272-101
REPORT DOCUMENTA T10N 11. REPORT NO. . 2. 3. Recipient'. Ace...lon No.
PAGE' EPA/ROD/R09-93/094
4. TItI8 .nd Subtitle Ii A8por1 Date
SUPERFUND RECORD OF DECISION 08/26/93
Lorentz Barrel & Drum, CA " 6.
. .
Second Remedial Action - Final
7. Aulhor(.) a. Performing Organization Rept No.
"
8. Performing Organlz8tlon Name and Add..... 10 Proj8c:t TulclWork Unit No.
11. Contr8Ct(C) or Grant(G) No.
(q
:
(0)
12.. ~ Organization Name and Add,... 13. Type of Raport . PerIod Covered
U.S. Environmental Protection Agency /
401M Street, S.W. 800/800
Washington, D.C. 20460 14.
15. ~ary Not.
PB94-964522
15. Ab8tr8Ct (Umlt: 200 words)
The Lorentz Barrel & Drum site is an inactive drum recycling facility located 13 miles
southeast of the southern tip of San Francisco Bay in San Jose, Santa Clara County,
California. The site consists of the 6.72 acre, former Lorentz Barrel & Drum facility,
a limited amount of adjacent City of San Jose sidewalk property and ashall9w ground-
water plume, extending north of the site. Land use in the area is mixed industrial,
comme'rcial, residential, and recreational. In addition; the site features include
shallow and deep aquifers ; a contaminated shallow ground water plume area; five
buildings which housed the drum reconditioning facilities; several sumps; an open
storage bin located adjacent to the processing facility; various piles of wood; rusted
metal debris; and numerous empty and nonhazardous drums. Less than 3,000 people reside
within a one-mile radius of the Lorentz Barrel & Drum (LB&D) property, and three public
water supply well fields for 'the, drinking water and irrigation are also within a one-
mile radius. In 1947, the Lorentz family began recycling drums on the property and
continued until facility operations ceased in 1987., Around 1954 other facilities on
the original LB&D property included an auto wrecke~, a junkyard, a roofing company, a
construction company, and a sandblasting company. LB&D Facility operations consisted
(See Attached Page)
17. Document Analya!a a. Descrlptora
Record of Decision - Lorentz Barrel & Drum, CA
, ,
Second Remedial Action - Final
Contaminated Media: soil, debris
Key Contaminants: VOCs, other organics (dioxin, PCBs, pesticides), metals (arsenic,
chromium, lead)
b. Jd8ntlftef'8lOpen-Ended T...ms
Co COSATI Fl8IdIGroup
1a. Availability Slat-nt 18. Security C1888 (Thla Report) 21. No. of Pages
None 92
31., Security Claa (This Page) , 22. PrIce
None
(See ANSI-Z3t.18)
SNlnatfUt:llon8 on R..,.,..
OPTIONAL FOAM 272 (4-77)
(Formerly NTJS..35)
Department of Comm8n:8
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EPA/ROD/R09-93/094
'Lorentz Barrel & Drum, CA
Second Remedial Action - Final
Abstract (Continued)
of receiving drums for recycling; which consisted of emptying all residues, cleaning,
resealing, repainting, and reselling the drums. Residues were removed from the drums by
various methods, including caustic .and acid washes, incineration, blasting with steel
shot, and steam cleaning. Drums were then resurfaced, resealed, and repainted using
various substances, including phenolic epoxy resins and rust inhibitors.. From the 1950s
until between 1976 and 1978, a drainage ditch from the processing facility was utilized to
drain wastes to a large sump, which discharged to the storm drain system. Between 1968
and 1971, the discharge was diverted to the sanitary sewer. Discharge to the sanitary
sewer ceased in 1983 or 1984, when liquid waste was reportedly reduced in volume by
evaporation, drummed, and disposed of as hazardous waste along with incinerator ash,
residual liquids, and sludge. Surface runoff was collected and recycled in the hot caustic
wash cycle of the drum recycling process. In 1981, EPA and the State began six years of
soil and ground water sampling from 6nsite and offsite monitoring wells,. which indicated
numerous metals, organic, and PCB contamination. As a direct result of operations at the
LB&D facility, ,a large variety of chemical residues from drums and the drum reconditioning
process have contaminated the soil, structures, . and shallow ground water at and beneath
the site. In late 1987 and 1988, EPA and site PRPsjointly conducted .emergency response
actions to remove approximately 3,000 yd3 of highly contaminated soil at the former main
sump area and over 26,000 drums, and paved the majority of the site. Later that year, EPA
issued a ROD for expedited cleanup of, the shallow ground water, as OU2. In 1991, EPA
installed 10 monitoring wells to better define the ground water contaminant plume
boundaries and to provide deep aquifer monitoring. In 1990, EPA and 11 PRPs signed a
consent decree requiring the PRPs .to design, construct, and operate a shallow ground water
extraction and treatment system to address the VOC contamination of' the ground water
beneath the site~ as well 'as the plume that extends approximately.2,000 feet north from
the former main sump. In 1992, EPA and a group of 7 PRPs signed an Administrative Order
of Consent also requiring these PRPs to remove buildings, sumps, drums, and miscellaneous
debris, expected to be completed in 1994. This ROD addresses a final action for the
contaminated soil and debris, as OU1. The primary contaminants of concern affecting the
soil and debris are VOCs; other organics, including dioxin, PCBs, and pesticides; and
metals, including arsenic, chromium, and lead.. .
The selected remedial action for this site includes treating 9,700 tons of contaminated
soil using soil vapor extraction and granular activated carbon to remove and capture VOCs,
with offsite treatment by carbon regeneration to destroy the VOCs; capping the remaining
contaminated soil and debris with asphaltic concrete pavement to eliminate the exposure
pathway to building pads and soil contaminated with non-mobile chemicals; monitoring for
VOCs in deeper aquifiers and. soil and gas; removing, and disposing of the contaminated
.. septic system and sewer line, contaminated incinerator ash, stockpiled soil containing
greater than 50 ppm PCBs, non-essential wells acting as potential conduits, miscellaneous
debris, and the uncontaminated warehouse off site to reduce potential exposure to or
migration of contaminated residues; and implementing institutional controls, including
deed and land use restrictions. The estimated present worth cost of this remedial action
is $1,970,000, which includes an annual O&M cost of $63,000.,
PERFORMANCE STANDARDS OR GOALS:
'Soil cleanup levels are based upon EPA cap action levels and Federal and State standards,
~nd include aldrin 0.8 ~g/kg; arsenic 23 rng/kg; chlordane 2 mg/kg; chromium 475 mg/kg;
4,4-DDD 10 mg/kg; 4,4-DDE 10 mg/kg; 4,4~DDT 10 mg/kg; dieldrin 0.8 mg/kg; endosulfan 1.6
mg/kg; lead 500 mg/kg; PCBs 1.7 mg/kg; and 2,3,7,8-TCDD 0.086 ug/kg.
. ,
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,'\'
"....,. \
:m::: RECORD OF DECI:SI:ON ;:)::'
I I
~ffi1 it
1111':1:1 PART I: DECLARATION jj::~~
I PART II: DECISION SUMMARY I
I~ wi
:::::::::: ::::::::::
I I
I I
I I
August 26, 1993
PART
III:
RESPONSIVENESS
SUMMARY
u.S.
ENVIRONMENTAL PROTECTION AGENCY
REGION
9
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. PART
SECTION
I 1.0
I 2.0
I 3.0
I 4.0
I 5.0
5.1
5.2
5.3
.5.4
5.5-
5.6
II
1.0
1.1
1.2
1.3
1.4
1.5
1.6
, 1.7
1.8
CONTENTS
PART I:
DECLARATION
SITE NAME AND LOCATION
. . . . . . .
. . . .
STATEMENT OF BASIS AND PURPOSE
. . . .
. . .
ASSESSMENT OF THE SITE. . . .
.......
DESCRIPTION OF THE REMEDY
. . .
. . . . . .
~
. . 7
. . 7
. . 7
. . 7
STATUTORY DETERMINATIONS. . . . . . . . . . . . 9
protectiveness. . . . . . . .. . . . . . 9
Applicable or Relevant and Appropriate
Requirements. .. . . ... . . . . . . .. 10
Preference for Treatment as a Principal
Element. . . . . . . . . . . . . . . .. 10
SITE
SITE
2.0
2.1
2.2
2.2.1
2.2.1.1
2.2.1.2
2.2.1.3
2.2.1.4
2.2.2
2.2.3
2.2.4
2.2.5
2.2.6
, 2.3
II
Use of Permanent Solutions, Alternative
Treatment or Resource Recovery
Technologies. . . . . . . . ~ . . . . .
Cost Effectiveness. . . . . . . . . . .
Summary. . . . . . . . . . . . . . . . .
PART II:
DECISION SUMMARY
NAME, LOCATION, AND DESCRIPTION. . . . .
site Name and Location. . . . . . . . .
Topography . . . . . . . . . . . . . . .
Adjacent Land Use. . . . . . . . . . . .
Historical Land Use. . . . . . . . . . .
Geology. . . . . . . . . . . . . . . . .
Hydrogeology. . . . . . . . . . . . . .
Water Use. . . . . . . . . . . . . . . .
structures. . . . . . . . . . . . . . .
HISTORY AND ENFORCEMENT ACTIVITIES. . .
History of Site Activities. . . . ,. . .
History of Site Investigations. . . . .
Soil. . . . . . . . . . . . . . . .
Soil with Risk-Based COCs . . .
Principal Threat Soil. . . . .
Vicinity/Background Soil. . .
Coyote Creek Sediments. . . .
Water. . . . . . . . . . . . . . .
Air. . . . . . . . . . . . . . . .
Condui ts . . . . . . . . . . . . . .
structures/Debris. . . . . . . . .
Residues. . . . . . . . . . . . . .
History of Enforcement Actions. . . . .
1
10
10
11
12
12
14
14
15
15
15
19
20
20
20
22
23
23
24
25
25
25
25
26
26
27
27
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II 3.0 COMMUNITY RELATIONS 29
II 4.0 SCOPE AND ROLE OF THE RESPONSE ACTION .... 29
4.1 Scope of the Response Action 29
4.2 Role of the Response Action 30
4.2.1 Relationship with OU-2 ....... 30
4.2.2 Relationship with Removals 31
II 5.0 SUMMARY OF SITE CHARACTERISTICS 32
5.1 Sources of Contamination 32
5.2 Description of Contamination 32
5.2.1 Soil 32
5.2.1.1 Soil with Risk-Based COCs ... 32
5.2.1.2 Principal Threat Soil ..... 37
5.2.1.3 Vicinity/Background Soil ... 38
5.2.1.4 Coyote Creek Sediments .... 38
5.2.2 Water . . . 39
5.2.3 Air 40
5.2.4 Conduits . 40
5.2.5 Structures/Debris 40
5.2.6 Residues . 41
II 6.0 SUMMARY OF SITE RISKS 42
6.1 Contaminant Identification . 42
6.2 Exposure Assessment 42
6.3 Toxicity Assessment 45
6.4" Risk Characterization 46
6.4.1 Soil 46
6.4.1.1 Soil with Risk-Based COCs ... 46
6.4.1.2 Principal Threat Soil ..... 47
6.4.1.3 Vicinity/Background Soil ... 47
6.4.1.4 Coyote Creek Sediments .... 47
6.4.2 Water 48
6.4.3 Air 48
6.4.4 Conduits 49
6.4.5 Structures/Debris 49
6.4.6 Residues 50
6.4.7 Uncertainties 50
6.5 Presence of Sensitive Populations .... 51
6.6 Presence of Sensitive Ecological Systems 51
6.7 Conclusion 52
II 7.0 APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENTS 52
7.1 Types of ARARs 53
7.2 Site Specific ARARs . 53
II 8.0 DESCRIPTION OF ALTERNATIVES 58
8.1 Remedial Action Objectives 58
8.2 Soil Cleanup Standards 59
8.3 Compliance Boundaries 61
8.4 Remedial Action Alternatives 64
8.4.1 No Action 65
8.4.2 Hybrid Closure Cap 65
8.4.3 Excavation and Off-Site Disposal . . 68
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II 9.0 COMPARATIVE ANALYSIS OF ALTERNATIVES . . . . . 70
9.1 Criteria . . . . . . . . . . . . . . . . 70
9.2 Analysis of Alternatives . . . . . . . . 71
II 10.0 THE SELECTED REMEDY . . . . . . . . . . . . . 82
10.1 Basis of Selection . . . . . . . . 82
10.2 Features of the Remedy . . . . . . . . . 82
II 11.0 STATUTORY DETERMINATIONS . . . . . . . . . . . 86
11.1 Protectiveness . . . . . . . . . . . . . 86
11.2 Applicable or Relevant and Appropriate
Requirements . . . . . . . . . . . . . . 87
11.3 Preference for Treatment as a Principal
Element . . . . . . . . . . . . . . . . . 88
11.4 Use of Permanent Solutions, Alternative
Treatment or Resource Recovery
Technologies . .. . . . . . . . . . . . . 88
11.5 Cost Effectiveness .. . . . . . . . . . . 88
11.6 Summary . . . . . . . . . . . . . . 89
II 12.0 DOCUMENTATION OF SIGNIFICANT CHANGES.. . . . . 89
PART III: RESPONSIVENESS SUMMARY
III 1.0 INTRODUCTION . . . . . . . . . . . . . . . . . 90
1.1 - Overview . . . . . . . . . . . . . . . . 90
1.2 Background on community Involvement . . . 90
III 2.0 COMMUNITY PREFERENCES . . . . . . . . . . . . 92
2.1 Previous Community Preferences . . . . . 92
2.2 Preferences Raised at Community Meeting . 93
2.3 Preferences Raised During Public Comment 93
III 3.0 INTEGRATION OF COMMENTS . . . . . . . . . . . 94
3.1 Summary of Major Comments . . . . . . . . 94
3.2 Comprehensive Response to All Comments 95
ATTACHMENT A:
Administrative Record Index
3
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TABLE
5.1
5.2
5.3
6.1
7.1
8.1
8.2
8.3
10.1 .
FIGURE
1.1
1.2
1.3
1.4
8.1
LIST OF TABLES
TITLE
Soil Contaminants of Concern
. . . .
. . . .
. . .
Soil Contaminants Not of Concern
. . .
. . .
. . .
Materials to be Addressed by the Final Remedy. . .
Maximum Risks Associated with COCs
. . . .
. . . .
ARARs For Selected Remedy
Cap Action Levels for Soil
. . .
. . . .
. . . . .
. . . . . . .
. . . . .
Estimated Amount of Soil' Exceeding
Cleanup Standards. . . . . . . . .
........
Comparison of Estimated Costs for
Cleanup Al ternati ves . . . . . .. . . .
. . . . . .
Summary of Estimated Costs for the
Selected Remedy: Hybrid Closure. .
. . . . . . . .
LIST OF FIGURES
TITLE
Map of LB&D Site and Immediate Vicinity
Simplified Hydrogeologic Profile
. . .
. . .
. . . . . .
. . .
Map of Shallow Groundwater Plume
. . . .
. . . . .
Surface and Subsurface Structures at LB&D site
Map of Soil Contamination Above Cleanup standards.
4
PAGE
33
34
35
43
54
60
63
69
84
PAGE
13
17
18
21
62
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ADI
AL
AOC
ARARs
BAAQMD
BDAT
bgs
BHRA
BNA '
Cal-EPA
Cal-OSHA
CFR
CCR
CCS
CD
CDI
CERCLA
CERCLIS
COCs
CPFs
CRP
CRQL
DCA
DCE
DDD
DDE
DDT
DHS
DRE
DTSC
EE/CA
EETB
FR
FS
FUS
GAC
HEAST
HI
HOC
IDLs
IRIS
kg
LB&D
LDR
LSGTF
LSP/PHE
MCL
LIST OF ACRONYMS
Acceptable Daily Intake
Action Level
Administrative Order on Consent or
Area of Contamination
Applicable or Relevant and Appropriate Requirements
Bay Area Air Quality Management District
Best Demonstrated Available Technology
below ground surface
Baseline Health Risk Assessment
Base/Neutral and Acid Extractables
California Environmental Protection Agency
California Occupational Safety and Health
Administration
Code of Federal Regulations
California Code of Regulations
Current Conditions Scenario
Consent decree
Chronic Daily Intake
Comprehensive Environmental Response, Compensation, ,and
Liability Act of 1980 .
Comprehensive Environmental Cleanup Liability
Information System
contaminants of concern
Cancer Potency Factors
Community Relations Plan
Contract Required Quantitation Limit
Dichloroethane
Dichloroethene
Dichlorodiphenyldichloroethane
Dichlorodiphenyldichloroethylene
Dichlorodiphenyltrichloroethane
Department of Health Services (State of california)
Destruction Rate of Eff iciency --
Department of Toxic Substances Control (formerly part
of DHSi now part of Cal-EPA)
Engineering Evaluation/Cost Analysis
Environmental Epidemiology and Toxicology Branch (part
of state of California Department of Health Services)
Federal Register
Feasibility Study
Future Use Scenario
Granulated Activated Carbon
Health Effects Assessment Summary Tables
Hazard Index
Halogenated organic compound
Instrument Detection Limits
Integrated Risk Information System
Kilogram
Lorentz Barrel & Drum
Land Disposal Restriction
Lorentz Shallow Groundwater Task Force
Limited Sample Plan/Public Health Evaluation
Maximum Contaminant Levels
5
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mg
msl
NCP
NPL
O&M
OSWER
OU-l
OU-2
PAHs
PCB
PCDD
PCDFs
PCE
PCP
ppb
ppm
PRPs
PSS
RD/RA
RfDs
RFI
ROD
RWQCB
SARA
SCVWD
SIP
SJSU
SJWC
SVE
TBC
TCDD
TCDFs
TCE
TSCA
TTLC
URS
USC
VOC
milligram
mean sea level
National contingency Plan
National Priorities List
Operation and Maintenance
Office of Solid Waste and Emergency Response
Operable unit One
operable unit Two
Polycyclic Aromatic Hydrocarbons
Polychlorinated Biphenyl
Polychlorinated Dibenzodioxin
Polychlorinated Dibenzofuran
Tetrachloroethene
Pentachlorophenol
parts per billion
parts per million
Potentially Responsible Parties
Pacific Sandblast Services
Remedial Design/Remedial Action
Chronic Reference Doses
Recycled Fibers, Inc.
Record of Decision
Regional Water Quality Control Board
Superfund Amendments and Reauthorization Act of 1986
Santa Clara Valley Water District
State Implementation Plan
San Jose State University
San Jose Water Company
Soil Vapor Extraction
To-Be-Considered
2, 3,7, 8-Tetrachlorodibenzo-p-dioxin
Tetrachlorodibenzofurans
Trichloroethene
Toxic Substances Control Act
Total threshold limit concentration
URS Consultants, Inc.
united States Code.
Volatile Organic Compound
6
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PART I:
DECLARATION
1.0
SITE NAME AND LOCATION
Lorentz Barrel & Drum Superfund site
South Tenth Street and East Alma Avenue
San Jose, California 95112
EPA ID# CAD 029295706
2.0
STATEMENT OP BASIS AND PURPOSE
This Record of Decision (ROD) presents the selected remedial
actions for Operable Unit One (OU-1) at the Lorentz Barrel & Drum
(LB&D) Superfund site in San Jose, California. This document was
developed 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. SS 9601 et sea., and, to the extent
. practicable, in accordance with the National Oil and Hazardous
Substances Pollution Contingency Plan, 40 C.F.R. Part 300
(National Contingency Plan [NCP]). The attached administrative
record index (Attachment A) identifies the documents upon which
the selection of the remedial action is based.
The State of California, through the California Environmental
Protection Agency's (Cal-EPA) Department of Toxic Substances
Control (DTSC), concurs with the selected remedy. .
3.0
ASSESSMENT OP THE SITE
Actual or threatened releases of hazardous substances from the
. LB&D site, if not addressed by implementing the response action
selected in this ROD, may present an imminent and. substantial en-
dangerment to public health, welfare, or the environment.
4.0
DESCRIPTION OP THE REMEDY
This operable unit (OU-1) addresses all remaining sources of
contamination not already addressed by the removal of barrels,
drums, and soils completed in 1988; the removal of structures,
sumps, drums, and debris scheduled for 1993 and 1994; and the
Operable Unit 2 (OU-2) shallow groundwater extraction and.
treatment system. Therefore, the OU-1 remedy selected in this
ROD is considered and referred to as the "final remedy" for the
LB&D site. While this remedy addresses contaminated soil, one of
the principal threats at the LB&D site, OU-2 will continue to
address the principal threat posed by contaminated shallow
groundwater.
7
-------
The selected remedy, which addresses soil, groundwater, vadose
zone soil gas in residential areas, vertical and horizontal
conduits, structures, debris, and residues, consists of the
following major components:
(1)
(2)
(3)
(4)
(5)
(6)
(7)
Treatment by soil vapor extraction (SVE) of principal threat
soil containing volatile organic compounds (VOCs) at
concentrations that total more than 1 ppm;
containment by a cap (single layer asphaltic-concrete
pavement without leachate collection or monitoring systems)
using long-term maintenance to ensure elimination of the
exposure pathway to building pads and soil contaminated with
non-mobile chemicals (e.g., polychlorinated biphenyls
(PCBs), pesticides, and metals);
Removal and off-site disposal of contaminated septic system
and sewer line following their excavation to reduce
potential exposure to or migration of contaminated residues;
Removal and off-site disposal of contaminated incinerator
ash, stockpiled soil containing greater than 50 parts-per-
million PCBs, non-essential wells acting as potential
conduits, miscellaneous debris and the uncontaminated
warehouse;
Monitoring for VOCs in deeper aquifers and in soil gas
selected residences to provide advance warning in the
unlikely event that significant migration of shallow'
groundwater contaminants begins;
near
Reviews of the protectiveness of the selected remedy to
occur at least once every five years in accordance with
section 121(c) of CERCLAj and
Land use restrictions to prevent well construction (for
water supply purposes) in source areas that remain
contaminated and deed restrictions for those properties
(LB&D, Recycled Fibers, Inc. [RFI] and the adjacent sidewalk
area belonging to the City of San Jose) that contain
contaminated soil exceeding cap action levels. Restrictions
will prohibit residential development and will limit
industrial development to activities that do not breach the
integrity of the cap or do not mobilize the soil
contaminants. Restrictions will also preclude excavation,
other than temporary subsurface work beneath the cap and
will require complete restoration of any disturbed fill or
cap once any such temporary work is completed.
8
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5.0
STATUTORY DETERMINATIONS
5.1
PROTECTIVENESS
The selected remedy is protective of
environment. Protection is achieved
in the aquifers extending beyond the
following ways:
human health and the
at this industrial site, and
former LB&D facility, in the
(1)
The cap will protect humans from direct contact with
building pads and contaminated soil present at or adjacent
to the former LB&D facility. In addition to the LB&D and
RFI properties, the cap will cover all adjacent soil (e.g.,
adjacent city sidewalk area) that exceeds the cap action
levels for contaminants of concern (COCs). Risk will be
reduced to zero because the cap breaks the exposure pathway.
Soil adjacent to LB&D site boundaries would not be sUbject
to the cap because it does not exceed cap action levels.
The cap will also minimize contaminant leaching by surface
water infiltration. .
(2)
Extraction of VOC-contaminated soil vapors followed by
capture of the VOCs on granular activated carbon will
protect the shallow groundwater from further degradation by
these highly mobile contaminants. Health risks from the
VOCs would be eliminated because they will be destroyed
during regeneration of the granular activated carbon.
Removal and off-site disposal of non-essential wells located
in the vicinity of the shallow groundwater contamination
plume will reduce the potential for the wells to act as
vertical migration conduits for shallow groundwater
contaminants. In addition, excavation and off-site disposal
of the contaminated septic system and sewer line will reduce
potential exposure to or migration of contaminated residues.
(3)
(4)
Removal and off-site disposal of contaminated incinerator
ash from the LB&D facility operations,. stockpiled soil
containing greater than 50 ppm PCBs, and contaminated debris
and residues will prevent future direct human contact with
these contaminated materials.
(5)
Additional protection from future potential human exposure
to contaminated groundwater will be provided by a mechanism
. for early warning in the unlikely event that. shallow
groundwater contaminants migrate towards .the deep, drinking
water aquifer. Both the intermediate and deep aquifers will
be monitored for VOCs on a semi-annual basis to alert the
community if VOCs are detected. In a similar fashion,
monitoring of the soil gas near residences situated above
the shallow groundwater plume will provide advance warning
in the unlikely event that VOCs begin a significant
migration towards the confined spaces of dwellings.
Land u~erestrictions will prevent well construction (for
water supply purposes) in source areas that remain
(6)
9
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, contaminated. Deed restrictions will be imposed for those
properties (LB&D, RFI, and the adjacent sidewalk area
belonging to the City of San Jose) that contain contaminated
soil exceeding cap action levels. Deed restrictions will
prohibit residential development and will limit industrial
development to activities that do not breach the integrity
of the cap or do not mobilize the soil contaminants.
Restrictions will also preclude excavation, other than
temporary subsurface work beneath the cap and will require
complete restoration of any' disturbed fill or cap once any
such temporary work is completed.
5.2
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIRBKENTS
The selected, remedy complies with federal and state requirements
that are legally applicable, or relevant and appropriate (ARARs)
to the remedial action.
5.3
PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
The selected remedy will use SVE to treat all of the VOC-
contaminated soil, which is about 15 percent of the contaminated
, soil at the LB&D site. This in situ treatment will occur only on
the LB&D. property. Extracted VOCs will be captured on granular
activated carbon and subsequently destroyed off-site during the
carbon regQneration 'process. No other treatment processes are
involved in the final remedy, mostly because of the lack of
technologies that can effectively treat the heterogeneous mix of
LB&D soil COCs. Because principal threat soil is treated, the
selected remedy satisfies the statutory preference for treatment
as a principle element of the remedy. .
5.4
USE OF PERMANENT SOLUTIONS I ALTERNATIVE TREATHENT OR
RESOURCE RECOVERY TECHNOLOGIES
Permanent solutions, alternative treatment and alternative
, resource technologies were evaluated during the Feasibility Study
(FS), but were not determined to be practicable or cost effective
for most of the contaminated soil at the LB&D site, largely
because of the heterogeneous mixture of COCs. By its use of SVE
for principal threat soil, the selected remedy utilizes permanent
solutions and alternative treatment technologies to the maximum
extent practicable.
Because this remedy will result ~n hazardous substances remaining
on-site above health-based levels and the cap will require long-
term routine maintenance, a review will be conducted within five
years after commencement of the remedial action and every five
years thereafter, to ensure that the remedy continues to provide
adequate protection of human health and the environment.
5.5
COST EFFECTIVENESS
The remedy is cost effective because adequate protection is
achieved for the estimated cost of performance. The analysis
contained in the FS and this ROD demonstrates that additional
10
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remedial action and the cost associated with that action would
not achieve a significantly greater reduction in risk, but would
result in a dramatically higher cost. The FS and this ROD also
show that a lesser effort and a lower cost would result in a
measurably higher risk at the LB&D site.
5.6
StJMMARy
The selected remedy is protective of human health and the en-
vironment, complies with ARARs, and is cost-effective. This
remedy utilizes permanent solutions and alternative treatment
technologies to the maximum extent practicable, and satisfies the
statutory preference for remedies that employ treatment that.
reduces toxicity, mObility, or volume as a principal element.
Because the remedy will result in hazardous substances remaining
on-site ~bove health-based levels, ,a five-year review, pursuant
to Section 121(c) of CERCLA, 42 U.S.C. 59621(c), will be
, conducted at least once every five years after initiation of the,
remedial action to ensure that the remedy continues to provide
adequate protection of human health and the environment.
~ .
C. W\Lt.
n C. Wise
Acting Re9~onal Administrator
1'.2.".q~
Date
11
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PART II:
DECISION SUMMARY
This Decision Summary provides an overview of the problems posed
by the LB&D Superfund site, the remedial alternatives, and the
analysis of the remedial alternatives. This Decision Summary
explains the rationale for the remedy selection and how the
selected remedy satisfies the statutory requirements.
1.0
SITE NAME, LOCATION, AND DESCRIPTION
1.1
SITE NAME AND LOCATION
Lorentz Barrel & Drum Superfund site
1515 South Tenth Street
Corner of South Tenth Street and East Alma Avenue
San Jose, California 95112 '
CAD # 029295706
The LB&D site is located at the above address in Santa Clara
County, about 13 miles southeast of the southern tip of San
Franci~co Bay (Figure 1.1). The LB&D site is defined as all land
previously used for LB&D facility operations and all areas where
contamination from the LB&D facility operations has come to
reside. The LB&D site includes a contaminated shallow
groundwater plume area and properties containing contaminated
soil, structures, debris, and residues. Figure 1.1 shows the
locations of the various areas of the LB&D site that are'defined
and described below. For purposes of reference, the first
appearance of a defined area in the text below is underlined.
These defined terms will be used throughout the remainder of this
document. .
The oriqinal LB&D oropertv consisted of 10.5 acres located at the
southern corner of South Tenth Street and East Alma Avenue in the
City of San Jose. A 3.78-acre portion of the original property
was never significantly involved in the LB&D drum recycling
operations and was transferred shortly after theLB&D operations
began. This portion includes the 3.39-acre Norton/Phelps
orooerty and a 0.39-acre Western Pacific Railroad easement. This
portion is located at the southeastern end of the original LB&D
property and is not considered part of the LB&D site.
The remaining 6.72-acre portion of the original 10.5-acre LB&D
property that is contaminated from operations of the former LB&D
facility is part of the LB&D site. This portion includes the
LB&D orooerty, defined as the 5.25-acre, L-shaped parcel that
contained the LB&D facility operations in 1987. The former LB&D
facility included all the buildings, equipment, and land that
LB&D used in operating the drum recycling business from 1947
onward~ Before 1981, facility operations also occurred on
neighboring property, currently owned by RFI, that once was part
12
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Story Road
Landfa
CoyoteCreek
Parking
SJSU
Student
Housing
Kelley Park
' Playing
Field
JSU Spartan
Stadium Wai
»RFI
San Joae
Muni BasebaO
Stadkim
LBW
Prepwty
LORCNTZ BARREL
AND DRUM SITE
NORTH
FIGURE
1.1
MAP OF LB&D SITE AND IMMEDIATE VICINITY
13
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of the original 10.S-acre LB&D property. The 1.47-acre RFI
property includes the 1.32-acre RFI parcel (388 East Alma Avenue)
that is occupied by the RFI paper recycling business operations.
(formerly known as Arata Western) and the O.lS-acre Pacific
Sandblast Services (PSS) parcel (400 East Alma Avenue) that is
occupied by the PSS business operations. PSS once leased its
parcel from LB&D and now leases its parcel from RFI.
In addition to the former LB&D facility. property, the LB&D site
also includes a limited amount of adjacent City of San Jose
property. The ad;acent city sidewalk area is defined as soil
belonging to the City of San Jose located between the LB&D
property fence lines parallel to East Alma Avenue and to South
Tenth Street and their respective street pavements. While' the
former LB&D facility operation did not officially involve the
adjacent city sidewalk area, it is likely that contaminated
runoff from the LB&Dproperty contaminated soil beneath the
sidewalks.
Finally, the area above the shallow groundwater plume is also
part of the LB&D site, although there is no known surface or
shallow. soil contamination in this area, except for those
portions of the plume that lie under LB&D, RFI, and adjacent
sidewalk area properties.
city
1.2
TOPOGRAPHY
The topography of the LB&D property is nearly flat, with a slight
slope from the southwest corner to the northeast corner. The
highest elevation at the southwest corner is 106 feet above mean
sea level (msl), and the lowest point at the northeast corner is
102 feet above msl. The regional topography slopes gradually to
the north toward Coyote Creek. Elevations south of the LB&D site
are between 10S and 110 feet above msl and gradually decrease in
the northerly direction toward Coyote Creek to between 9S and 100
feet above msl. .
1.3
ADJACENT LAND tJSE
The LB&D and RFI property, and the surrounding area to the south
and west are zoned for commercial/industrial use per the City of
San Jose Planning Department. The predominant zoning within a
1-mile radius of the LB&D property is commercial/industrial. The
residential and recreational district to the north and east of
the LB&D property includes Spartan Stadium (San Jose State
University [SJSU] football stadium), San Jose Municipal Stadium
(City of San Jose), and SJSU recreation fields. The City of San
Jose intends to maintain and further develop the recreational
uses of land to the north and east of the LB&D site.
The closest residence to the LB&D property is the SJSU student
housing on South Tenth Street, located approximately 700 feet
north. single family residential houses are located 1,100 feet
north 'of the LB&D property. Less than 3,000 people are estimated
to live within a 1-mile radius of the LB&D property. .
14
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1.4
HISTORICAL LAND USE
The majority of the San Jose area developed from agricultural use
to the current predominant residential/commercial/industrial use.
Review of a 1939 aerial photograph indicates that, prior to
development of the LB&D and RFI properties, the nearest
developments to the LB&D property consisted of Spartan Stadium to
the northwest, SJSU tennis courts to the north, residential'
housing to the north, and railroad tracks to south.
A 1954 aerial photograph shows the LB&D drum reconditioning
facility, including two warehouses. Other facilities on the
original LB&D property included an auto wrecker in the southwest
corner, California Roofing and Lou Jones Construction to the
south of the LB&D facility and PSS to the north. Drums were
stored on most of the open areas at the former LB&D facility,
including at least half of the property that is now owned by RFI.
Between 1954 and 1968, the warehouse to the west of the
processing facility was reportedly destroyed by fire and other
structures were added or modified. The 1971 aerial photograph
indicates that the northwe$t portion of the LB&D property (part
of-the RFI property) was fenced from the remainder of the LB&D
property. This property was used as a junkyard. The 1976 aerial
photograph of the current RFI property shows that the area was
filled with automobiles (presumably junked), while in a 1980
aerial photo, the majority of the automobiles were gone. The
1982 aerial photograph shows the main RFI facility constructed~
The basic structures on the LB&D property remained largely'
unchanged after 1968. From the photo, it appears that roadway
improvements and sidewalk additions on both East Alma Avenue and
South Tenth Street, which occurred in the late 1970s or early
1980s, may have covered over portions of land impacted by the
LB&D facility operations.
1.5
GEOLOGY
The LB&D site lies near the axis of the Santa Clara-Valley (a
deep, broad, northwest tending alluvial basin) situated between
the Santa Cruz Mountains to the southwest and the Diablo Range to
the northeast. The basin sediments are divided into the lower
Plio-Pleistocene Santa Clara Formation, which is somewhat
consolidated and has been slightly deformed, and the upper
Quaternary alluvium, which is poorly consolidated. Both units
consist of interbedded gravel, sand, silt, and clay and cannot be
reliably differentiated in well logs. .
1.6
HYDROGEOLOGY
Water that is considered part of the LB&D site is comprised of
the shallow and deep aquifers. The LB&D site is located in the
southeastern region of the San-Jose water resources subarea.
This groundwater basin subarea is an important groundwater source
due to the extent, thickness, and permeability of the deep water-
bearing' units. Numerous water-bearing units (aquifers) underlie
the LB&D site, separated by thick low-permeability marine clay
15
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layers (aquitards) formed. during past incursions of San Francisco
Bay.
There are four predominantly granular water-bearing or
potentially water-bearing subsurface zones below the LB&D site.
These zones have been designated with respect to increasing depth
below ground surface (bgs) as Zone A, Zone B, Zone C, and Zone D
as shown in Figure 1.2. The contaminated shallow groundwater
currently located. in Zone B comprises OU-2. If contaminated
groundwater from Zone B also comes to exist in Zone A (e.g., a
rise in the water table or resaturation), Zone A. groundwater
would be addressed under OU-2. The deep aquifer (Zones C and D)
and potential conduits between the shallow and deeper aquifers
comprise the groundwater portion of OU-1. Unsaturated portions
of Zone A lying above the contaminated groundwater in Zone B
contain low levels of VOCs. .VOC-contaminated soil gas and soil
in Zone A are considered part of OU-1.
Zone A extends from the existing grade to approximately 20 feet
bgsand is comprised of sand and silty sand with occasional
lenses of silt and clay. Soil borings completed through Zone A
indicate that the soils are generally dry, although it may
. contain seasonal perched groundwater. Zone A is underlain by a
2- to 7-foot-thick clay/silty clay aquitard with occasional local
sandy to clayey silt discontinuities near or under the LB&D site
that connect Zone A to the underlying Zone B.
Zone B contains VOCs as groundwater contamination (Figure 1.3)
and is predominantly comprised of sands and silty sands with
occasional lenses of sandy gravel, silt, and silty clay. These
soils are encountered at depths starting at approximately 25 feet
bgs. Zone B is a semi-confined aquifer and is currently the
uppermost water-bearing unit under the LB&D site. Groundwater
levels in Zone B range from approximately 18 to 30 feet bgs and
the flow direction is northerly. Conduits may exist which could
transfer VOC contaminants from the shallow aquifer to deeper
. aquifers.. .
Underlying Zone B is an approximately 35-foot-thick aquitard,
encountered at depths from approximately 35 feet bgs to .
approximately 70 feet bgs. This unit is comprised primarily of
very stiff clay/silty clay with occasional, discontinuous lenses
of silt separating the shallow aquifer contamination from
contaminating Zone C.
Zone C (starting from approximately 70 feet bgs) is predominantly
comprised of sand and gravel and has a groundwater flow direction
to the northwest.
According to Santa Clara Valley Water District (SCVWD), the
granular, water-bearing soils in Zones Band C comprise the
regional upper aquifer. The SCVWD indicates that groundwater
usage in the regional upper aquifer is limited to local domestic
or agricultural purposes. However, the SCVWD also indicates that
16
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o +102
ZONE A [Unsaturated Sill. Sand
(willi I*ch8cI_)) Gravel
20 AQUTAIU) Qey/Silly Qey 80
ZONE B [Saturated] Sands, Sb, 8I'Id Clays
~o with Gravel L....
60
AOUrTARO ClaylSiIy Clays
60 40
80 ZONE C (Unsaturated Course Sands, GnMtIs.
and CObbles wth 20
(wiIII.--s-)) Sill and ClaY Lenses
0
f=
w
w 120
!:::. -20
w ffi"
o
~ 140 -40 W
o u..
-
~ 160 Z
AOUrTARD MARINE CLAVS ~ 0
..J ~
W
C) ~
J:: 180 .ao
.-
~ w
w
0 200
.100
220 .120
240 .140
260 -160
280 ZONE D [Saturated] Course Sands. .180
Gravel
300 -200
320
SIMPLIFIED HYDROGEOLOGIC PROFILE
17
FIGURE
1.2
-------
+
..c,o
<>
.
.
,.-
/
6
--
{;
Approximate Zone B
Groundwater Gradient
Story Road
LandfiU
LEGEND
Approximate Location of
Technos Inc.'s Possible
Abandoned Well Casing
Zone C and Zone D
Monitoring Wells
Water Wells
Approximate Location of
Potentiol Conduits
NOr'l-Essentiol Wells
Approximate Sholiow
Groundwater Boundary 9/2/92
NORTH
~
0 250 FIGURE
500
, I 1.3
SCAL£ IN I'EET
Approximate Location for
Recommended GeophysicOI
Survey
Approximate Piping and
Building Locotion for LSGTF"
MAP OF SHALLOW GROUNDWATER PLUME
18
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some of the deep production wells in the groundwater basin may be
extracting water from both the upper and lower zones because of
the placement of multiple Perforations. This is the case for the
SJSU Spartan Stadium well and 'for the Kelley Park well; both are
gravel-packed across the Zone C and Zone D aquifers.
An approximate 100-foot-thick aquitard, consisting of silts and
clays, separates Zone C from Zone D. Zone D (encountered from
230 to 1,000 feet bgs) is comprised of thick beds of sand and
gravel interbedded with thick beds of silty and sandy clay. Zone
D comprises the regional lower aquifer, or deep aquifer, from
which Santa Clara Valley extracts an estimated 107,000 acre-feet
.of groundwater a year for irrigation and domestic uses. The San
Jose Water Company (SJWC) maintains and operates the 12th Street
well field, located on 12th Street, approximately 0.75 miles
north and downgradient of the LB&D property. The well field
consists of nine production wells which extract groundwater from
the Zone D aquifer for use as a municipal drinking water supply
for approximately 33,000 households in the area. Water levels in
wells at the 12th Street well field range from approximately 75
feet bgs to 150 feet bgs under pumping conditions. The expected
gradient for Zone D is toward the north. At locations within the
vicinity of the LB&D site, the gradient is influenced by the SJWC
. 12th Street well field. .
1.7
WATER USE
-
The LB&D site is located in the southeastern corner of the San
Jose subarea as defined by the California Department of Water
Resources. This subarea is one of the most important natural
sources of groundwater in the south San Francisco Bay area (South
Bay). The deep aquifer (250 to 400 feet bgs) is a major source
of potable groundwater, from which it is estimated that Santa
Clara Valley extracts 107,000 acre-feet per year. Three public
water supply well fields (owned by SJWC), located at the 12th
Street, Cottage Grove, and Needles Stations, are within 1 mile of
the LB&D site. An SJSU well is located at the Spartan Stadium.
Groundwater in the area is used for drinking and irrigation. The
nearby water wells all draw water from screened intervals located
at depths greater than 150 feet bgs. The principal groundwater
extraction wells for drinking water purposes are located in the
Zone D aquifer and are operated by the SJWC. The SJSU Spartan
Stadium well is used for both potable and irrigation purposes.
The Kelley Park well provides water for the fish pond and is not
used as a potable water supply. There are no extraction wells
located in the Zone B aquifer other than those used for treatment
of the contaminated groundwater.
Coyote Creek is located iess than 0.5 miles northeast of t~e LB&D
property. Historically, the primary uses of water from.. thJ.s' .
creek have been agricultural and to some extent recreational.
Its current principal value is the contribution to the ecology of
the South Bay. No other surface waters are located within 2
miles of the LB&D site.
19
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1.8
STRUCTURES
Approximately 2.75 acres of the LB&D property have been paved
with a tar and gravel mixture (chipped seal) to cover an area
. once used for drum storage. The paved area overlies soils which
are discolored and potentially contaminated. A small portion of
this 2~75 acres is covered by an asphaltic-concrete cover
installed by LB&D. The other 2.5 acres of the LB&D property are
unpaved but are covered by five buildings which housed the drum
reconditioning facilities, several sumps, an open storage bin
located adjacent to the processing facility, various piles of
. wood, rusted metal debris, numerous empty drums and numerous non-
hazardous drums. All of these structures and materials, with the
exception of an intact warehouse and drums of ash, are scheduled
to be removed in 1993 and 1994 by a group of potentially
responsible parties (PRPs) under a~ Administrative Order on
Consent (AOC) as more fully described below. Figure 1.4 shows
the locations of existing and former facilities. Some of the
facility structures, numerous barrels and limited amounts of soii
were removed from the LB&D site during 1987 emergency response
actions conducted by the California Department of Health
Services' (DHS's) toxic substances control division, (now known
as DTSC, a part of cal-EPA).
The RFI property includes both the RFI and PSS parcels, as shown
in Figure 1.4. The RFI parcel is completely covered by a
concrete s~ab, and the PSS parcel is entirely covered by asphalt.
2.0
SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.1
HISTORY OF SITE ACTIVITIES
The Lorentz family started recycling drums at the former LB&D
facility iri 1947. During the early years, portions of the
original LB&D property (10.5 acres) were also rented or leased to
other companies. Several facilities were in operation on the
.LB&D property around 1954, including an auto wrecker, a junkyard,
a roofing company, a construction company, and sandblasting
services. .
Drums for recycling were received from both private and public
sources throughout California and Nevada. Private sources
included over 2000 different companies and individuals,
representing chemical, food, health care, electronics, paint,
ink, and paper industries. Public sources included military
bases, research laboratories, and county agencies. Many drums
arrived at the LB&D facility containing residual aqueous wastes,
organic solvents, acids, oxidizers, and oils.
The LB&D facility operations consisted in part of ~mptying all
residues, cleaning, reseal~ng, repainting, and reselling the
drums. Residues were removed from the drums by various methods,
including caustic and acid washes, incineration, blasting with
20
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East Alma Avenue
PACIFIC
SANDBLAST
PROPERTY
RECYCLED
FlBERS. INC.
PROPERTY
LEGEND
,. Treatment Facility
2. Processing Facility
3. Residence
4. Former Incinerator
5. Shop and Bathrooms
B. Storage Facility
7. Warehouse and Offic8
8. Former Sump
. Existing Sump
PORTIONS REMOVED
BY LBacD AND DHS
IN 1983 AND 1985
I.
G
.
B.
Note.
LB6.D facility structures will be removed by PAPa in 1993 « ~.
,
r--,
\ :
I
I 8. I
I I
I I
I I
I I
LI7 .J
1/
/
DRAINAGE / I
DITCH I I
1/
II
II
/ I
/
....
Q)
Q)
~
....
(/)
~
....
o
.-
~
....
::J
o
(/)
NORTH
~
0 50 100 FIGURE
, 1.4
SCALE IN FEET
SURFACE AND SUBSURFACE STRUCTURES AT LB&D SITE
21
1.
~
,.
~
.
2.
.
7.
-------
steel shot, and steam cleaning. Drums were then resurfaced,
resealed, and repainted using various substances, including
phenolic epoxy resins and rust inhibitors.
From the 1950s until some time between 1976 and 1978, a drainage
ditch from the processing facility .was utilized to drain wastes.
The drainage ditch discharged to a large sump (approximately 30
by 80 feet) located in the northern corner of the LB&D property
bounded by the corner of East Alma Avenue and South 10th Street.
Aerial.photographs of the LB&D site from that time period reveal
the presence of liquids in the sump, drainage ditch, and various
ponded areas. The sump discharged to the storm drain system.
Between 1968 and 1971, the discharge was diverted to the sanitary
sewer.
Previous investigations have indicated that discharge to the
sanitary sewer ceased in 1983 or 1984. After 1984, liquid wastes
were reportedly reduced in volume by evaporation, drummed, and
disposed as hazardous waste along with incinerator ash, residual
liquids, and sludge. Surface runoff was reportedly collected and
recycled in the hot caustic wash cycle of the drum recycling
process. As a result of the LB&D facility operations, a large
variety of chemical residues from drums delivered to the LB&D
site, as well as chemicals used by the LB&D facility in its drum
reconditioning processes, have contaminated soil, structures, and
shallow groundwater at and beneath the LB&D site. Contaminated
groundwater has also migrated about 2,000 feet north of the LB&D
property.
The LB&D facility ceased operations in.1987. In late 1987 and
early 1988, DTSC and the u.S. Environmental Protection Agency
(EPA) conducted emergency response actions at the LB&D site that
included removal of 3,000 cubic yards of highly contaminated
soils at the former main sump area and over 26,000 drums, some of
which contained residues. At the conclusion of the removal
action~ the'majority of the LB&D property wCis paved over.
In 1992, pursuant to a Consent Decree (CD) with EPA, a group of
eleven PRPs, known as the Lorentz Shallow Groundwater Task Force
(LSGTF), completed construction of and began operating a shallow
groundwater extraction and treatment system. This system
addresses the VOC contamination of groundwater bepeath the LB&D
site, as well as the plume that extends approxim~tely 2000 feet
north from the former main sump.
Recently, a separate group of seven PRP companies, known as the
Structures Removal Group, has begun a removal of buildings,
sumps, drums, and miscellaneous .debris pursuant to an AOC with'
EPA. They are expected to complete the removal in 1994.
2.2
HISTORY OF SITE INVESTIGATIONS
Since 1981, there have been several environmental sampling
studies at the LB&D site aimed at investigating the' nature and
extent of contamination.. Over a period of 6 years DTSC and LB&D
have collected soil and groundwater samples from on-site and off-
22
-------
site monitoring wells. Numerous metals, organics, and PCBs were
found above Total Threshold Limit Concentrations (TTLC).
Sampling results from these efforts are summarized in' section 5.0
of this Decision Summary. .
In 1988, EPA began field activities for the Remedial
Investigation (RI). The RI included sampling and analysis of
surface and subsurface soil, facility structures, groundwater,
sediments, and surface water; a geophysical survey; topographic
surveying and mapping; pump tests; borehole geophysics;
geotechnical sampling; air sampling; and biota sampling.
Additionally, a limited well survey was performed, and potential
conduits were investigated.
Beginning in 1991, EPA commenced field activities for six RI
addenda. For RI Addendum NO.1, EPA installed eight Zone B, one
Zone C, and one Zone D monitoring wells to better define the
groundwater contaminant plume boundaries and to provide deep
aquifer monitoring. RI Addendum No.2 included sampling of 30
soil borings on the RFI property to assess the impact of the LB&D
operations on the RFI property. RI Addendum No.3 updated the
Baseline Health Risk Assessment (BHRA) contained in the RI by
evaluating soil risks under a residential use scenario. It also
modeled and evaluated potential risk from the vapor-phase
migration of groundwater contaminants up to the surface and into
confined spaces of buildings located above the plume.
In RI Addendum No.4, EPA assessed the location and status of
potential conduits and whether additional conduits existed along
the leading edge of the plume~ In RI Addendum.No. 5, EPA
investigated the stockpiled soil excavated from the treatment
facility foundation to assess the soil contamination present.
The sampling results of the stockpiled soil were compared with
previous investigation results t~ evaluate heterogeneity of LB&D
soil. For RIAddendum No.6, EPA installed one Zone C monitoring
well to serve as a warning well for the SJSU Spartan Stadium well
and to better define the characteristics of the Zone C aquifer
immediately downgradient from the original source area.
In addition, various sampling and analysis activities have been'
performed by the Structures Removal Group as part of the removal
of structures, debris, equipment, and drums. Specific sampling
activities have been performed on drum contents, sump liquids,
and building materials.
2.2.1
soil
2.2.1.1
Soil with Bealth-Risk-Based cocs'
There are two basic categories of soil COCs that remain at the
LB&D site. Some contaminants have been identified as health-
risk-based COCs because they contribute a significant level of
cancer or non-cancer risk for direct exposure as determined in
the RI risk assessment. All of the contaminated soil at the LB&D
site contains health-risk-based COCs. However, most of this soil
23
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poses a low level threat because the COCs have low mobility in
the environment, and are present near health-based levels.
In a few small areas near former sumps, the soil also contains
VOCs at concentrations that threaten to contaminate groundwater.
VOCs are not included as health-risk-based COCs because of their
limited occurrence in contaminated soils and the absence of a
direct human exposure threat from their presence in soil.
Instead they are considered a separate category of COCs because
they represent a principal threat to the groundwater environment.
LB&D ProDertv. The 5.25 acre LB&D property was originally
investigated by LB&D in 1982, by DTSC and EPA in the mid and late
1980s, and most recently by 'the Structures Removal Group as part
of the waste profiling necessary for off-site disposal. A
discussion of the sampling performed on the LB&D property on the
surface, subsurface and stockpiled soil is presented below.
surface soil. Limited investigations of the surface soil have
been conducted by LB&D and DTSC in addition to EPA's RI soil
sampling. Data collected by LB&D and DTSC are of limited use
because the data were not validated. EPA conducted the RI
starting in 1988 and issued the RI Report in 1990. The focus of
the RI was on the LB&D property. However, off-site surface
samples were taken to assess background chemical concentrations.
subsurface soil. Investigation of the subsurface soil was
. conducted as part of the RI. RI Addendum No.5 reported the
results of three additional soil borings sampled to assess
\ heterogeneity of the LB&D site's soil contaminants.
stockpiled soil. During the geotechnical investigation conducted
for the LSGTF shallow groundwater treatment facility, pesticide
and PCB contamination was encountered. During excavation
activities, the LSGTF removed and stockpiled approximately 1,000
cubic yards of potentially contaminated soil at the LB&D
property. A portion of this stockpiled soil (10 cubic yards) was
excavated for installation of a utility line to service the
treatment facility. The stockpiled soil was subsequently
investigated (RI Addendum No.5) to assess contaminant levels and
heterogeneity in the LB&D site soil contaminants.
Nei~hborina ProDerties. The neighboring properties consist of
the RFI property and the adjacent City of San Jose sidewalk area
bordering the LB&D property. The RFI property was investigated
as part of RI Addendum No.2. The sidewalk area was not directly
investigated, but EPA believes that there is contamination based
on RI results from soil samples taken adjacent to the sidewalk
and on a 1954 aerial photograph. Runoff from the former LB&D
facility flowed over the sidewalk area nearest the corner of E.
Alma Avenue and South Tenth Street.
2.2.1.2
Principal Threat Soil
The principal threat soil poses a potential groundwater threat
and is defined as soil containing VOCs at a combined total
24
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concentration greater than 1 part per million (ppm). The
principal threat soil has been identified through the soil
borings conducted alongside the sumps and from samples taken of
the sump contents.
2.2.1.3
Vicinity/Backqround soil
EPA performed the vicinity/background sampling as part of the
Limited sample Plan/Public Health Evaluation (LSP/PHE) and the
RI. The LSP/PHE investigated off-site garden soil for pesticide
and PCB contamination. The RI evaluated off-site locations to
assess background concentrations of contaminants for comparison
to the LB&D site contamination.
2.2.1.4
Coyote Creek Sediments
The sediments in Coyote Creek were investigated to assess if
discharges from the LB&D site to the storm drain impacted Coyote
Creek. Investigations were conducted during both the LSP/PHE and
RI to assess temporal trends.
2.2.2
Water
Water concerns at the LB&D site involve groundwater (Zones A - D)
and the surface water of Coyote Creek (0.5 miles to the east).
Groundwater (Zones A-D). The Zone B shallow groundwater contains
the contaminant plume. Zone A is currently dry. The deeper
Zones C and D aquifers are used for irrigation and drinking water
purposes. The Zone A through C aquifers were addressed as part
of the original RI. Additional wells in Zones B, C, and D were
installed as part of RI Addendum No.1. The Zone Dwell (MW-44)
provides an early warning mechanism in case contamination is
transferred via conduits to the deeper aquifers. As part of the
RI Addendum No.6 investigation of the Zone C aquifer, EPA
installed an early warning well (MW-45) upgradient of the SJSU
Spartan Stadium well. The installation of MW-45 assisted in
determining the regional groundwater gradient in the Zone C
aquifer.
Coyote Creek. Surface water samples were collected near the
Coyote Creek outfall of the storm drain once used by the former
LB&D facility. Sampling was conducted for the LSP/PHE and RI.
2.2.3
Air
soil Gas. EPA conducted modeling of the soil gas emissions due
to the VOCs in the shallow groundwater contaminant plume as part
of RI Addendum No.3. The potential health risk effects were
evaluated for residences above the groundwater contaminant plume.
Surface Air and Dust. EPA evaluated the surface 'air and dust
exposure routes during the RI. The objective was to assess if
soil contamination at the LB&D site was impacting breathing zones
adjacent to the LB&D site. Upwind and background samples were
also collected.
25
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2.2.4
conduits
l'
Identification of conduits at the LB&D site includes both
vertical and horizontal conduits.
Vertical conduits. Because of the importance of attempting to
locate all potential conduits that threaten to convey shallow
groundwater contaminants to the drinking water aquifer, three
different conduit investigations were conducted. An initial
conduit survey was performed by DTSC.As part of the RI and RI
Addendum NO.4, EPA performed further document investigations and
door-to-door searches for potential conduits.
Horizontal Conduits. EPA conducted a limited investigation of .
potential horizontal conduits on the LB&D site during the RI.
EPA performed a geophysical survey and subsequent test pit
investigation as part of the RI. A redwood tank, which is
. thought to be part of the former LB&D facility septic system was
encountered during the test pit investigation. In addition,
sewer and water lines are suspected to exist at the,LB&D property
and further investigation is required to establish their
existence and locations.
2.2.5
structures/Debris
Buildinas/Eauipment. Wipe sampling of the buildings and
equipment was conducted as part of the RI. The structures,
Removal Group conducted additional sampling to better profile the
buildings and equipment for off-site disposal.
Pavements/Pads. Sampling of the various concrete pads was
conducted as part of the RI~ The various bermedand paved areas
have not been sampled because of their limited volume.
Surface Drains. The surface drains have not been sampled because
of their limited volume. However, analytical data obtained from
. the sump residues, which were discharged to the surface drains,
indicate potential contamination of the surface drains.
Sum~s. Sampling and analysis of the sump structures have not
been conducted. However, the sump contents were sampled by EPA
during the RI and, more recently, by the Structures Removal
Group.
septic Tank. EPA conducted an analysis of the septic tank as
part of the test pit investigation (Test pit No.4) during the
RI. Sampling was performed on the soil surrounding the septic
tank~
Debris Pile and other Debris. Although the various debris piles
at the LB&D property have not been sampled, EPA conducted
sampling of the adjacent buildings and equipment during the RI.
Based on the adjacent sampling and field observation, EPA expects
that the debris contains minimal contamination. The debris piles
will be removed 'by the Structures Removal Group. '
26
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Remaininq Drums. Various drums remain that will be removed by
the structures Removal Group. The drums are mostly empty,
although some contain acids and caustics used as part of the LB&D
drum cleaning operation. Because the majority of the drums do
not contain materials and are limited in number, they have not
been sampled.
2.2.6
Residues
-
Contents of structures and Conduits. EPA has not conducted
sampling of the structures and conduits. However, for those
structures connecting the sumps, EPA expects that the structure
and conduit residues will be similar to the residues discovered
in the RI analysis of sump residues.
SumD Residues. EPA conducted an analysis of the sump residues
during the RI. Subsequent sampling was conducted by the
structures Removal Group as part of the profiling necessary for
off-site disposal.
Incinerator Ash. EPA conducted sampling and analysis of the
incinerator ash as part of the RI. Subsequent sampling was
conducted by the Structures Removal Group as part of the
profiling necessary for off-site disposal of drum contents.
2.3
HISTORY OF EHFO~CEKENT ACTIONS
Since 1968, federal, State, and local authorities have taken many
regulatory and enforcement actions at the LB&D site. A complete
chronological list of enforcement events is provided in Appendix
1-A of the RI. In summary, the major enforcement actions have
included:
1968 - City of San Jose industrial waste inspector ordered
Lorentz to switch sump discharge from coyote Creek
storm drain to the sanitary sewer.
1980 -
California occupational safety and Health
Administration (Cal-OSHA) informed DHS of potential
problems with hazardous materials at the Lorentz
facility. LB&D site is entered into EPA's CERCLIS
database.
1982 - DTSC inspected the facili~y and issued a Notice of
Violation to Lorentz' for soil and groundwater
contamination.
1983 -
The Regional Water Quality Control Board (RWQCB)
began investigating potential threats to the
groundwater from sumps and other LB&D facility
activities and issued Clean Up & Abatement Order No.
83-007. U.S. Dept. of Fish & Game cited Lorentz for
violations involving heavy metals and petroleum
products in surface runoff leaving the LB&D facility
and entering the storm drain to coyote Creek.
27
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1984 -
1985 -
San Jose/Santa Clara Water Pollution Control District-
cited Lorentz for violations and issued a cease and
desist order for discharge into sanitary sewer. EPA
completed a Preliminary Assessment and site
Investigation and proposed the LB&D site for the
National Priorities List (NPL). .
DTSC cited LB&D with 14 violations of the California
Administrative Code and Federal Regulations
concerning the handling and storage of hazardous
wastes. The Santa Clara County District Attorney
obtained a Temporary Restraining Order to close .down
operations at LB&D. Operations resumed after 3
months.
The Santa Clara County District Attorney filed a
criminal complaint against LB&D and Ernest Lorentz
which alleged the defendants had committed one felony
and 13 misdemeanor violations of the California
Hazardous Waste Control Act. The RWQCB issued
Corrective Action Order #86-001 requiring LB&D to
determine the lateral off-site extent of groundwater
pollution.
1987 - The LB&D facility ceased operation. EPA assumed the
lead agency responsibility for the LB&D site
- remediation.
1986 -
1988 - EPA and DTSC completed removal of 3,000 cubic yards
of highly contaminated soils and over 26,000 drums.
EPA paved most of the LB&D property.
1988 - EPA issued the OU-2 ROD for expedited cleanup of the
shallow groundwater.
1989 - EPA sent Special Notice to 43 PRPs to start
negotiations on the OU-2 ROD. The LB&D site went
from proposed to final on the NPL.
1990 -
1992 -
EPA and 11 PRPs (the LSGTF) signed a CD requiring the
PRPs to design, construct, and operate a shallow
groundwater extraction and treatment system as
specified in the OU-2 ROD.
EPA and a group of 7 different PRPs (the Structures
Removal Group) signed an AOC that requires the PRPs
to remove from the LB&D property and dispose of the
remaining barrels, asbestos, site debris, structures
(except the concrete pads and the warehouse), and
sumps.
1993 - EPA proposed a final remedy addressing all remaining
contamination at the LB&D site.
28
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I '
3.0
COMMUNITY RELATIONS
The RIfFS report and Proposed Plan for the LB&D site were
released to the public in May 1993~ These two documents were
made available to the public in both the Administrative Record
and the information repositories maintained at the SJSU Library,
San Jose Main Library and EPA Region" 9 Superfund Records Center.
The notice of the availability of these two documents was
published in the San Jose Mercurv News on May 19, 1993. A public
comment period was held from May 17, 1993 through June 17, 1993.
In addition, a public meeting was held on May 27, 1993. At this
meeting, representatives from EPA answered questions about the
LB&D site and the remedial alternatives under consideration. A
response to the comments received during this period is included
in the Responsiveness Summary, which is part of this ROD. This
decision document presents the selected remedial action for the
LB&D site in San Jose, California, chosen in accordance with,
CERCLA, as amended by SARA, and, to the extent practicable', the
NCP. The decision for the LB&D site is based on the
Administrative Record.
A more detailed description of the history of community relations
'activities at the LB&D site, the background on community
involvement and concerns, and specific comments and responses ~n
EPA's proposed plan for the final remedy are included in the
Responsiveness Summary (Part III) of this ROD.
4.0
SCOPE AND ROLE OF THE RESPONSE ACTION
4.1
SCOPE OF THE RESPONSE ACTION
The main objective of the response action selected as the final
remedy for the LB&D site is to protect human health and the
environment from all remaining releases or threats of releases of
hazardous substances that have not already been addressed by
. previous or current cleanup actions at the LB&D site. The
materials of concern include groundwater in deeper aquifers,
vadose zone soil gas near residences situated above the shallow
groundwater contaminant plume, vertical and horizontal conduits
(e.g., old agricultural wells and sewer lines), structures and
debris (e.g., septic tank), residues (e.g., LB&D incinerator
ash), soil contaminated with health-risk based COCs, and, the
only principal threat remaining unaddressed at the LB&D site,
soil contaminated with VOCs that threaten groundwater.,
The response action objectives are:
(1)
Treat or remove principal threat soil that threatens to
contaminate groundwater;
Reduce potential exposure to other, non-mobile soil
contaminants;
(2)
(3)
Reduce potential exposure to contaminated structures,
conduits, debris and residues;
29
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(4)
Reduce potential groundwater migration and surface water
infiltration by removing non-essential wells that could act
as potential conduits; and
(5)
Provide advance warning to drinking water suppliers and
residents in the event that shallow groundwater contaminants
begin significant migration to deeper aquifers or towards
confined spaces of dwellings.
To address the response action objectives, three alternatives
were evaluated during the FS. Alternative 1 is the no action
alternative and was evaluated as a basis for comparison with the
two action alternatives. Alternative 2, involving a hybrid
closure cap and soil vapor extraction, was presented as EPA's
preferred alternative in the Proposed Plan. Alternative 3
involves excavation and off-site disposal of contaminated soil
and other contaminated material. Each of these alternatives is
described in more detail in Sections 8 and 9 of this ROD.
.Section 10 further describes Alternative 2 as the selected
response action.
4.2
ROLE OP .THE RESPONSE ACTION
The selected response action is the final remedy in a series of
cleanup activities that have been or are currently being
conducted at the LB&D site. In 1988 EPA and DTSC performed a
joint removal of contaminated soil and drums. EPA then divided
, the LB&D site into two operable units. OU-1 addresses the
overall LB&D site and source control while OU-2 specifically
addresses the contamination in the shallow groundwater. A
limited removal of sumps, structures, and debris is currently
being perform~d by seven companies pursuant to an AOC with EPA.
Because a remedy was selected for OU-2 before a remedy was
selected for aU-1, the OU-1 remedy selected in this ROD is
considered and referred to as the final remedy.
4.2.1
Relationship with OU-2: Shallow Groundwater Cleanup
The 1988 ROD for the OU-2 shallow groundwater response action
included the following objectives: 1) control plume migration by
preventing existing contamination in the shallow aquifers (i.e.,
Zones A and B) from migrating deeper and farther from the LB&D
site, 2) attempt to retard north and northeasterly migration and
discharge of contaminated shallow groundwater to Coyote Creek,
and 3) remove contaminated water from the shallow aquifer to
greatly reduce the possibility of contamination of potable water
supplies. To meet these objectives, the 1988 ROD requires
design, construction, and operation of a groundwater extraction
and treatment system based in part on further information.
gathered during the OU-l RI. No other separate types or zones of
shall~w groundwater contamination were identified during the RI.
The 1990 CD requires the LSGTF to implement the 1988 ROD. They
are currently operating a shallow groundwater extraction and
treatment system and monitoring the Zone B aquifer. If
necessary, they will monitor the Zone A aquifer and Coyote Creek.
30
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The groundwater extraction and treatment system design includes a
contingency plan in the unlikely event that the currently .
operating extraction and treatment system fails to reduce
contaminant levels at the leading edges of the shallow
groundwater plume.
The 1988 ROD and 1990 CD for the OU-2 shallow groundwater remedy
do not address all aspects of potential migration of shallow
groundwater contaminants to deeper aquifers. While the ongoing
shallow groundwater remedial action is directed at controlling
lateral migration of the plume and eventually reducing
contamination to acceptable levels, the pumping will, to some
extent, also reduce potential downward migration of contaminated
shallow groundwater. Since the OU-2 ROD does not directly
address potential migration of shallow groundwater contaminants
to deeper aquifers through conduits, the OU-1 selected remedy
will address potential conduits. Remediation of deeper
groundwater contamination, if any were found during the RI, has
always been considered to be part of OU-1. Monitoring of deeper
aquifers will be performed as part of the final remedy to verify
that potential conduits are not a problem and to provide advance
warning in the event that contaminants migrate to the deeper
aquifers. .
Although soil gas was not addressed by the OU-2 ROD, the decrease
in shallow groundwater VOC concentrations resulting from
implementation of the OU-2 remedial action is expected to have
the complementary effect of reducing VOC concentrations in the
vadose zone soil gas (Zone A). This in turn will reduce the
likelihood of significant migration of voe contaminants through
soil gas towards dwellings situated above the contaminant plume.
Monitoring of soil gas near residences will be performed as part.
of the final remedy to verify models that predicted that, even
under a worst case scenario, the risk from VOCs in confined
spaces would still be within the EPA acceptable risk range. Such
monitoring would also provide advance warning in the event that
VOCs begin significant upward migration. Unsaturated portions of
Zone A containing VOC concentrations that threaten groundwater
will also be addressed by the final remedy.
4.2.2
Relationship with soil, Drums, and structures Removals
In early 1988, EPA and DTSC removed most of the drums (over
26,000) and the most heavily contaminated sump and associated
soils (3,000 cubic yards). Some full or partially full drums,
empty drums, small sumps, and a variety of debris were left
behind to be addressed by the OU-1 RI/FS and final remedy.
During the course of the RI/FS and the OU-2 Remedial
Design/Remedial Action (RDfRA), the condition of these remaining
structures and materials deteriorated and began to present
further threats of releases of hazardous substances at the LB&D
site. In addition, trespassers added to the threats of releases
of hazardous substances by dismantling some of the facility
structures and exposing asbestos covered piping. Accordingly, in
1992, EPA signed ,an Aoe with seven PRPs (structures Removal
31
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Group) requiring the PRPs to remove the exposed asbestos material
and to contain the leaking drums. In addition, the AOCrequires
the Structures Removal Group to prepare an engineering
evaluation/cost analysis (EE/CA) and, based on the EE/CA, to
remove all remaining sumps, and most of the remaining structures,
debris, and drums from the LB&D property.
Upon completion of the removal, the structures Removal Group is
required to secure the Lorentz property by boarding up the
remaining warehouse, covering remaining drums of incinerator ash
with a plastic covering, and paving over any exposed surface
soils. In addition, they will mark the extent of sump
excavations to delineate the boundary between original Lorentz
soils and clean backfill. This removal action will facilitate
implementation of the final remedy.
5.0
SUMMARY OF SITE CHARACTERISTICS
5.1
SOURCES OF CONTAMINATION
The LB&D facility received. barrels and drums' for recycling from
numerous businesses. The barrels and drums often contained
chemical residues (e.g., solvents, PCBs, and spent cleaning
fluids) from the businesses when the LB&D facility received them.
These residues sent ,to the LB&D facility were discharged by LB&D
to various-sumps, drains, or the ground. The processing of the
barrels and drums also led to the generation of residues such as
incinerator ash. Thus, the LB&D site soil and groundwater were
gradually contaminated over time by residues contained in the
used barrels and drums, incineration products of those residues,
and other chemicals used to handle, store, or recondition the
barrels and drums.
Soil COCs chosen for evaluation at the LB&D site are listed in
Table 5.1. contaminants not chosen as COCs because of low
toxicity, frequency of detection, and/or concentration are listed
in Table .5.2. The materials comprising OU-l are shown in Table
5.3.
5.2
DESCRIPTION OF CONTAMINATION
5.2.1
SOIL
The description of the soil characteristics for the LB&D site has
been divided into the soil exceeding the health-risk-based
cleanup standards for the COCs (Table 2-5 in the FS), the soil
considered a principal threat t~ the groundwater, and the
vicinity/background soil. The estimated volume of contaminated
soil is 50,000 in place cubic yards.
5.2.1.1
soil with Health-Risk-Based COCs
LB&D Prooertv. Soil contamination at the LB&D site was
identified during the RI through investigation of the surface,
32
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Table 5.1
SOIL CONTAMINANTS OF CONCERN(I)
LORENTZ BARREL & DRUM SITE
San Jose, California
F.-.quency of Detection Soil Concentration (ppm)
(00. detected! 10~
Contaminant DO. samples) Average of
Detections(2) Maximum(2) Risk(3) m = 0.1(3)
INORGANICS
-
Arsenic 271/274 (99%) 7.8 35.8 2.3 115.0
Chromium 271/274 (99%) 105.7 4400.0 NC 594.0
..
Lead 270/274 (99%) 148.5 9210.0 ND NA
ORGANICS
Pesticides
Aldrin 6/203 (3%) 0.310 0.780 0.08 1.14
-
Chlordane 171195 (9%) 0.316 1.6 1 2.22
4,4-DDD 25/265 (9%) 1.04 12.0 5 20.0
4,4-DDE 641305 (21 %) 1.82 27.0 4 . 20.0
4.4-DDT 36/238 (15%) 1.38 20.0 4 20.0
Dieldrin 13/281 (5%) . 0.09 0.52 0.08 2.0
Endosulfan 1/185 (0.5%) 4.2 4.2 NC 2.0
PCBs/Dioxin
PCBs (Total) 751204 (37%) 27.4 380.0 0.17 0.38
2.3.7.8-TCDD 16121 (76%) 0.16 0.51 0.0086 NA
(Eq.)(ppb)
LEGEND:
NA = Not Applicable
NC = Noncarcinogen
HI = Hazard Index
ND = Not Determined
ppb = parts per billion
ppm = parts per million
NOTES:
(I)
(2)
(3)
Information and data obtained from RI Report Table 4-1.
Average of detections and maximum is for surface and subsurface soil at the LB&D and RFI properties.
The soil concentration at 10-6 risk and an HI/I0 is based on a future use of the LB&D Site. The HI is equal to 0.1
(HI = 1 divided by 10 contaminants) to account for the potential synergistic effects of the 10 COCs. .
33
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Table 5.2
SOIL CONTAMINANTS NOT OF CONCERN(1)
LORENTZ BARREL & DRUM SITE
San Jose, California
Son Coueeotratiou (ppm)
Frequency of Detection
CoDtamUumt (DO. deteetedl Average of
DO. samples) DetectioUS(4) Maximum('" ur' rWk(2) m(3) = 1/12
Inomanics
Cadmium 41/274 (15%) .4.4 27 NC 95
Copper 270/274 (99%) 43.5 661 NC 3,152
Manganese 273/274 (99 %) 604.5 8,130 NC 18,983
Mercury 149/274 (54%) 0.5 10 NC 28
Nickel 209/274 (76%) 152.0 1,410 NC 1,898
Zinc 274/274 (100%) 145.0 2,660 NC 18,983
Or2anics
ButyIbcnzylphthalatc 271306 (9%) 1.66 7.4 NC 6,386
Di( ethylhexyl)phthalatc 1031306 (34 %) 2.0 26.0 0.096 NA
Dibutylphthalate . 20/298 (7%) 0.2 0.8 NC 3,191
Heptachlor 2/263 (I %) 0.1 0.26 0.3 NA
IsoPhorone 18/247 (7%) 1.1 9.6 327 NA
Phenol 261244 (11 %) 4.3 18 NC 319
1,2,~ Trichlorobenzene 23/180 (13%) 0.7 6.6 NC 936
.,
.'--
LEGEND:
NA = Not Applicable
NC = Noncarcinogen
ppm = parts per million
NOTES:
(I)
Infonuation and data obtained from RI Report Table 4-1.
(2)
Given the Jack of state and/or federal soil cleanup criteria, risk-based 'action' levels (ALs) for LB&D site soils were
developed. The calculation used to derive these levels is a simple extension of the risk equations used in the baseline
risk assessment, assuming future industrial use of the LB&D Site. For carcinogens, acceptable risk is fixed at a range
of 10-6 to 10-4; the equation is then solved for the contaminant concentration in soil that would incur that risk level.
(3)
Action levels (ALs) developed for noncarcinogenic contaminants were derived in a similar fashion, as described above,
but assumed a different (toxicity) endpoint. Therefore, back-ca1culations were perfonned to render a CDI/RID ratio
of 1.0 for each individual contaminant. Because this calculation does not account for cumulative (e.g., synergistic)
effects associated with exposures to multiple contaminants or mixtures, initial ALa were divided by the number of
. . noncarcinogerrlc contaminants evaluated (12) in the RI to render a more conservative 'cumulative' noncarcinogen AL.
(4)
Average of detections and maximum is for surface and subsurface soil at the LB&D and RFI properties.
34
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Table 5.3
MATERIALS TO BE ADDRESSED BY THE FINAL REMEDY
LORENTZ BARREL & DRUM SITE
San Jose, California
; , ,; '' JMATEJRlAitVF^ -
Groundwater
Air
Conduits
Vertical
Horizontal
Structures/debris
Residues
Soil
Risk-based COCs
Principal threat
- ' CONfAMG&tfe& :'*':VF"
•" \ . . . '. -r-ft
None(l)
Soil gas
None known
LB&D sewer lines
LB&D septic distribution line
Septic tank
Pavements/building pads
Drains
Incinerator ash
Spent GAC
Decontamination residues
LB&D property
Neighboring properties*2'
Excavated stockpiles
Soil near former sumps
/ , >:vto^tottMm>" * \
Aquifer Zone C
Aquifer Zone D
NA
Agricultural wells
SJSU Stadium wells
Non-essential monitoring wells
Old water line
Warehouse
Pavements/building pads
Miscellaneous
NA
Backfill^)
OJ
LEGEND:
NA=
NOTES:
(D
(2)
(3)
Not Applicable
Aquifer Zone A is presently dry, but Aquifer Zone B contains the contaminated shallow groundwater that is addressed by the 1988 OU-2 ROD
and 1990 Consent Decree.
Neighboring properties, known or assumed to have contaminated soil; include the RF1 property (both the RFI and PSS parcels) and the adjacent
City of San Jose sidewalk area.
Backfill may be needed for excavations and grading.
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subsurface, and stockpiled soil as described below. . A summary of
the various investigations conducted at the LB&D property prior
to the RI is provided in the 1988 ROD.
Surface soil. A total of 54 surface soil samples (including five
duplicates) were collected at the LB&D property. from 0 to 2 feet
bgs during the RI. No significant concentrations of VOCs were
detected. Butylbenzylphthalate was the most commonly detected
base/ne~tral and acid extractables (BNA) compound, ranging in
concentration from 79 to 7,400 parts per billion (ppb).
Di(ethylhexyl)phthalate was also found at concentrations up to
25,000 ppb. Other BNA compounds detected in LB&D property
surface soils were phenol and benzoic acid. Locations of
concentration maxima for these compounds coincided and occurred
in the area of the existing sumps near the processing facility.
Pesticides and PCBs were detected frequently in the surface soils
of the LB&D site. The occurrence of pesticides in LB&D site
surface soils generally parallels the distribution of PCBs,
although at lower concentrations. The pesticide
dichlorodiphenyldichloroethylene (DDE) was most prevalent, with
concentrations ranging from 29 to 29,000 ppb. The pesticides
. dichlorodiphenyldichloroethane (DDD) and
dichlorodiphenyltrichloroethane (DDT) were also present in
comparable concentrations. PCBs were predominant in terms of
magnitude and spatial extent with concentrations ranging from 230
to 380,00~ ppb. The highest concentrations of PCBs were detected
along the northern boundary of the LB&D property near the
location of the former main sump, and around the processing
facility.
Lead and chromium were the primary metals detected at
concentrations above background levels. The highest values of
lead, up to 9,210 ppm occurred in the vicinity of the processing
facility, with additional elevated concentrations occurring near
the southern boundary of the LB&D property. Concentrations of
. chromium up to 4,400 ppm occurred near the processing. facility.
Thirteen surface soil samples, including two collocated field
duplicate samples, were collected for dioxin/furan analysis by a
modification of EPA Method 8280, which quantifies the isomers of
greatest concern. All samples contained dioxin/furan
detections. The 2,3,7,8-Dioxin tetrachlorodibenzo-p-dioxin
(TCDD) isomer, considered to be the most toxic of the.
polychlorinated dibenzodioxin/polychlorinated dibenzofurans
(polychlorinated dibenzodioxin [PCDD]/polychlorinated
dibenzofuran [PCDF]), was detected in four surface soil samples
east of the processing facility. These locations also had more
detections of other PCDD/PCDFs than did other locations.
Concentrations of isomers were low enough that, when converted to
TCDD equivalents, values were near or below 0.5 ppb.
Subsurface soil. The discussion of VOCs in the subsurface soil
is provided in section 5.2.1.2. The spatial distribution of BNAs
generally occurred with maximum concentrations limited to the
deeper subsurface soils in the vicinity of the former sump area.
36
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Principal BNA subsurface contaminants include phenol, detected at
concentrations up to 12,000 ppb, di(ethylhexyl) phthalate (3,000
ppb), phenanthrene (6,480 ppb), and pentachlorophenol (PCP;
12,000 ppb).
PCBs were predominant (primarily Aroclor 1260, detected at
concentrations up to 63,000 ppb), with the pesticides DDD, DDE,
and DDT detected at concentrations up to 4,800 ppb. Maxima for
these compounds were detected in the northeast corner of the LB&D
property and west of the processing facility. Pesticides and
PCBs were generally limited to depths less than 10 feet bgs.
Of the metals analyzed, only arsenic (at a maximum concentration
of 35.8 ppm) and lead (at a maximum concentration of 391 ppm)
occurred at concentrations above background in subsurface soils.
Dioxin/furans (equivalents) were detected in two of six samples
at a maximum concentration of 0.182 ppb.
stockpiled soil. The BNAs bis(2-ethylhexyl)phthalate,
di-n-butylphthalate, and butylbenzylphthalate occurred with a
frequency of 95, 76, and 71 percent, respectively, with the
highest concentration being butylbenzylphthalate at 98,000 ppb.
Pesticides and PCBs were detected at concentrations above
instrument detection limits (IDLs) in all 21 samples analyzed
from the stockpiled soil with the highest concentration being
54,000 ppb for PCBs. Concentrations of the inorganic analytes
arsenic, cadmium, copper, mercury, nickel, and zinc are,
, consistent with background values identified in the RI Report.
Lead was detected at a maximum concentration of 977 ppm and
chromium was detected at a maximum concentration of 201 ppm.
The stockpiled soil generally contains higher average
concentrations of BNAs, pesticides and PCBs than encountered in
prior investigations conducted on LB&D and adjacent properties.
The results of the extensively sampled stockpiled soil indicate
that the former drum storage areas, assessed_as relatively
uncontaminated in the 1990 RI Report, are likely contaminated.
Neiahborina Prooerties. Investigation of the RFI property did
not detect total VOCs above 1 ppm. The BNA
bis(2-ethylexyl)phthalate was the most significant BNA detected
in terms of concentration (34,000 ppb). Results of the inorganic
analyses indicate that soil concentrations are consistent with
background levels established in the RI Report. PCBs (up to
1,700 ppb) exceeded the 10-6 risk levels in two samples and the
10-5 risk levels in one sample. The maximum pesticide
concentration was 3,800 ppb of DDT. Sampling conducted on the
LB&D property adjacent to the City sidewalk area along Alma
Avenue suggests that pesticide and PCB contamination extend under
the sidewalk area.
5.2.1.2
principal Threat soil
soil with greater than 1 ppm of total VOCs is termed' principal
threat soil. The principal threat soil is located in the former
sump area, as evidenced by high concentrations of VOCs in
37
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adjacent soil borings and the sump residues. The primary VOCs
detected are trichloroethene (TCE) and tetrachloroethene (PCE) at
maximum.concentrations of 940 ppb and 1,300 ppb, respectively.
The estimated volume of principal threat soil is 7,'200 cubic
yards (in place). VOC contamination was generally limited to the
deeper soil (10 to 20 feet bgs).
5.2.1.3
Vicinity/Background soils
Soil samples were collected from off-site locations (within 0.25
miles) .to assess background contaminant concentrations. PCBs
were detected' in one background sample (at 230 ppb) during the RI
and three perimeter samples (up to 1,200 ppb) during the LSP/PHE.
Of the BNAs, polycyclic aromatic hydrocarbons (PARSi up to 3,156
ppb) and phthalates (up to 4,600 ppb) were detected in both
investigations although with limited frequency. Lead and arsenic
were encountered at concentrations up to 366 ppm and 14.9 ppm,
respectively. .
Surface soil from residential gardens overlying the shallow
groundwater plume contained a variety of pesticides (up to 880
ppb of DDE) but no PCBs. DDE and DDT were detected (up to 20 and
37 ppb, respectively) in the surface soil from the Community
Garden east of the LB&D site. Contamination detected in the
residential gardens is not attributable to the LB&D site because
the contaminant concentrations increased with increasing distance
from the ~B&D site. Similar levels of pesticides can be found in
other areas that were once agricultural.
5.2.1.4
Coyote Creek Sediments
Analyses for pesticides, PCBs, and VOCs were conducted in the
Coyote Creek sediments at one upstream and three downstream
locations during the LSP/PHE, and at one upstream and six
downstream locations during the RI. VOCs were detected at or
below the Contract Required Quantitation Limits (CRQL) for both
investigations. Significant concentrations of PCBs (up to 7,300
ppb) and pesticides (DDD up to 3,300 ppb) were detected at two of
the farthest downstream locations (approximately 1 kilometer from
the LB&D site stormwater outfall). Concentrations of the BNAs
pyrene (2,500 ppb) and pentachlorophenol (up to 1,700 ppb) were
also detected. . .
Concentrations. of metals in the downstream samples were compared
to the upstream sample taken 100 yards up from th~ LB&D site'
stormwater outfalL Eighty-three'percent of the metals on the RI
Target compound List were detected at levels higher than those of
the upstream sample. Contaminants were detected at various
concentrations in all downstream samples, as well as in the
background sample, and their distribution is random. The LB&D
site does not appear to be a source for the sediment
contamination because of the lack of intermediate contamination
between the storm-drain outfall and farthest downstream sample.
38
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~
5.2.2
Water
Water relevant to the LB&D site is comprised of the shallow and
deep aquifers (Zones A through D) and Coyote Creek.. A summary of
the early groundwater investigations is provided in the 1988 ROD.
Groundwater (Zones A-D).
Zone A.Wells installed in 1988 in the shallowest potential.
water bearing zone beneath the LB&D site during the RI have been
dry since their installation. It is likely that most groundwater
contaminants migrated from sumps directly through Zone A to Zone
B, the first consistently water-bearing zone.
Zone B. Common VOCs detected in the shallow groundwater (Zone B)
and their approximate highest concentrations are TCE (900 ppb) ,
1,1-DCE (800 ppb) , 1,1-DCA (52 ppb) , vinyl chloride (170 ppb) ,
and benzene (78 ppb). Pesticides, PCBs, and metals have not been
confirmed in the shallow aquifer. Quarterly groundwater
monitoring is currently being conducted by the LSGTF with
oversight by the RWQCB and EPA. The shallow groundwater
.monitoring results obtained to date show no significant movement
of the plume since the 1988 ROD (see Figure 1.1). The
installation of the monitoring wells at the leading edge of the
plume has better defined the plume's limit.
Zone C. The intermediate groundwater aquifer (Zone C) is not
contaminated based on the findings of two years of quarterly
groundwater monitoring. TCE was once detected at 13 ppb in a
Zone C well located on the LB&D property near the former
processing facility. This detection was not confirmed during any
of the next five quarterly sampling events for this or any other
Zone C well.
Zone D. The deepest groundwater aquifer (Zone D) is used as a
. supply of drinking water and is uncontaminated. Nearby wells at
SJSU's Spartan Stadium and the SJWC's 12th Street Well Field have
been tested regularly for the presence of VOCs. No VOCs have
ever been detected in these wells. EPA installed a deep well
between the SJWC's well field and the leading edge of the shallow
groundwater plume. This well serves as a warning well in the
event that shallow groundwater contaminants migrate to the
deepest aquifer. No VOCs have been detected in this well either.
Coyote Creek. Water samples from six locations in Coyote Creek
contained no detectable concentrations of PCBs. All VOCs
detected (acetone, chloroform, and bromodichloromethane) were at
or below the CRQLs. No BNAs were detected above the CRQLs.
Three pesticides (endosulfan I, 2.0 ppb; 4,4'-DDE, 0.34 ppb; and
4,4'-DDD, 0.39 ppb) were detected at one sample location. The
observed random distributions of these contaminants in the creek
water suggest that the former LB&D facility was not the only
source of contamination to this section of Coyote Creek.
39
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5.2.3
Air
Soil Gas. A potential exposure route for VOCs present in the
groundwater to residences overlying the shallow groundwater
contaminant plume is through the vadose zone. Soil gas
monitoring for VOCs was not conducted during the RI. However,
the VOC flux from groundwater to surface air and potential indoor
air exposure risks have been calculated. Current VOC
concentrations in the shallow groundwater used to estimate VOC
concentrations in soil gas and confined spaces of dwellings do
not indicate potential exposure risks outside of EPA's acceptable
risk range (10-4 to 10-6).
-
Surface Air and Dust. Analytical parameters for air sampling
targeted pesticides and PCBs in both particulate and vapor.
phases., The only contaminant detected was alpha-BHC, which was
also found in the background sample. At this time, the LB&D site
is not a significant source of offsite air or dust contamination.
5.2.4
Conduits
Vertical Conduits. Vertical conduits consist primarily of former
agricultural wells and non-essential monitoring wells. The
former agricultural wells were typically screened in deeper
aquifers and have the potential to transfer shallow groundwater
contamination to deeper aquifers. The non-essential monitoring
wells are only in the shallow aquifer zones and have the
potential to transfer surface water into the shallow aquifer
zones. The well materials are only expected to be contaminated
at surfaces that came into direct contact with the shallow.
groundwater contaminant plume.
, Horizontal Conduits. Horizontal conduits consist of sewer,
water, and surface drain pipes. The contents of these various
conduits and their potential contamination will be addressed
below in Subsection 5.2.6 - Residues.
5.2.5
structures/Debris
Bui1dinQs/Eauioment. Analysis of building surface wipe samples
indicates that significant portions of the processing facility.
structure have pesticide and PCB contamination. The Structures
Removal Group will dispose of the former LB&D facility buildings
and equipment in 1994 with the exception of the large,
uncontaminated warehouse structure located in the southeast
portion of the LB&D property. The volume of the wooden
superstructure of the warehouse is 1,450 cubic yards.
Pavements/Pads. The various pavements, including the asphaltic
'chip-seal and bermed areas as well as the concrete pads, cover
the majority of the LB&D and RFI properties. Three core samples
taken from the concrete pads on the LB&D property contained BNAs
in all samples at concentrations less than 10 ppm. Pesticides
and PCBs were detected at all three locations, with the highest
40
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concentrations being 20,000 ppb for PCBs, 19,800 ppb for total
,chlordane, and 5,100 ppb for DDE.
Surface Drains. . The concrete surface drains are expected to have
contamination similar to the contaminated pavements and pads with
the primary contaminants being pesticides and PCBs. Residues
contained in the surface drains are expected to be similar to
those contained in the sumps to which the drains were connected.
Sumos.. Although the sumps will be removed in 1994, the soil
surrounding the sumps will not be removed by the structures
Removal Group. A description of the sump contents is provided in
Subsection 5.2.6 to provide further information on the likely
soil contamination adjacent to the sumps.
Seotic Tank. A redwood tank previously used as part of the
septic system for the LB&P facility was encountered during the
initial magnetometer survey and subsequent test pit
. investigation. Assorted debris, including cans, automobile
parts, rags, and bottles, was found in the test pit. VOCs
(toluene, ethylbenzene, and total xylenes) were detected at
levels up to 330 ppb; BNAs to 13,000 ppb (benzoic acid); and
PCBs to 31,000 ppb. significant metals contamination was
detected in samples collected from around the redwood tank (lead
up to 4,220 ppm and chromium up to 7,210 ppm).
Debris pile and Other Debris. The LB&D site contains various
debris piles consisting primarily of scrap metal such as
vehicles, drum lids, building fixtures, etc. The Structures
Removal Group will dispose of most of this debris in 1994. Only
materials supporting and covering the stockpiled soil will remain
as debris.
Remainin9 Drums. The majority of the drums remaining on the LB&D
site are empty and will be removed by the Structures Removal
Group in 1993 and 1994. Some drums that contain former LB&D
facility incinerator ash will remain. Characterization of the
ash residue is presented in the next section.
5.2.6
Residues
The residues part of OU-l includes the contents of various
structures and conduits, sumps, and the drummed incinerator ash
as described below.
Contents of structures and conduits. EPA expects that various
on-site structures and conduits such as the sewer line and
surface drains contain potentially hazardous residues. The
primary contaminants are expected to be PCBs and lead based on
analysis of sump residues as described below.
Sumo Residues. Although the sump residues and structures are to
be disposed of by the Structures Removal Group, the types of
contaminants present and their concentrations will have affected
the surrounding soil, and thus, they are relevant to this ROD.
Most of the COCs were detected at elevated levels in the sump
41
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residues. VOCs such as TCE and PCE were present at
concentrations of 83,OOOppb and 19,000 ppb, respectively. PCBs
and lead are present at concentrations up to 70,000 ppb and
20,900 ppb, respecti vely,.~," EPA expects that the surrounding sump
soil contains similar contaminants, but at potentially lower
concentrations.
Incinerator Ash. Approximately 15 cubic yards of incinerator ash
are contained in drums at the LB&D site. The incinerator ash
contains elevated levels of metals, including lead and chromium
at 13,300 ppm and 1,930 ppm, respectively. Comparison with the
soil data does not indicate significantly elevated concentrations
of other contaminants. TCDDs/tetrachlorodibenzofurans (TCDFs)
were detected in all ash samples up to hundreds of ppb levels.
Five furan congeners and three dioxin congeners were detected in
one or more samples. 2,3,7,8-TCDD, which is the most toxic
dioxin isomer, was not detected in the ash samples. However,
2,3,7,8-TCDF, the most toxic of the PCDFs, was detected in the
sample from inside the hopper at 0.088 ppb.
6.0
SUMMARY OF SITE RISKS
6.1
CONTAMINANT IDENTIFICATION
The media of concern for the LB&D site are soil, groundwater,
structures~ and air. subcategories within these media are
referred to as "materials" and include: principal threat'soil,
risk-based COCs soil, residues (ash and the contents of various
conduits), concrete building pads and pavements, and conduits
(horizontal and vertical). The main contaminants identified for
each media include:
.
Soil: principal Threat - VOCs
Risk-Based COCs - PCBs, metals, pesticides (Table 6.1)
.
Groundwater:
Shallow Groundwater - VOCs
'.
structures/Debris:
Surfaces - primarily pesticides and PCBs
. Air: Vapor emissions from shallow ~roundwater - VOCs
Dust from risk-based COC soil - COCs (Table 6.1)
The LB&D risk assessment (including RI Addendum No.3) evaluated
the health risks associated with the risk-based COC soil,
groundwater, and air. The health risks associated with the other
materials were not evaluated because of either limited
contamination and/or volume. The risk assessment used the
arithmetic mean and maximum contaminant concentrations to model
exposure risks.
6.2
EXPOSURE ASSESSMENT
6.2.1
Exposure Pathways and ,Receptors
A baseline risk assessment typically evaluates a site in the
absence of any remedial action. However, at the LB&D site,
42
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Table 6.1
MAXIMUM RISKS ASSOCIATED WIm SOIL
LORENTZ BARREL & DRUM SITE
San Jose, California
SOIL CONCENTRATIO~2)
Contaminant
CANCER RISK(1)
(CR)
HAZARD INDEX(1)
(HI)
Inorganics:
Ar~enic
Chromium
.:~f~~tll~tIj~1~~~~~~~~~~~~IftI~~[~~~t~i~1~~t~llit]~ffitili*i~~~i~r~1i~J~~lli~1*tI~~~~~~[j~1~t~~1~~~J~~ilii~~1~i1t~~t~i
Lead
Organics:
Pesticides
Aiddn
Chlordane
I. 46 x 104
NC
ND
~
w
4,4-DDD
4,4-DDE
4,4-DDT
Dieldrin
Endosulfan
PCBs/Dioxin
PCBs (Total)
2,3,7,8-TCDD (Ppb)
0.310
0.316
1.04
1.82
1.38
0.09
4.2
0.780
1.6
12.0
27.0
20.0
0.52
4.2
4.39 x 10-5
7.50 x 10-6
I. 02 x 10-5
3.25. x 10-5
2.41 x 10-5
9.13 x 10-6
NC
0.151
0.165
0.149
0.335
0.248
0.0198
0.520
I~~~~t111i1~~i~~~~m~~~ff.~~~~~~~i~~~~~~~1~11~i1~~~~~~~~I~l~1~~t~1~("":'
.:~~~~f~~iiI~lrf~~f~~~1~i~~~1~~~i~~~~~~~rt~~rn
27.4
0.16
380.0
0.51
TOTAL
1.04 x 10-2
2.88 x 104
I. 1 x 10-2 (3)
236
239(3)
LEGEND: .
NA = Not Applicable
NC = Noncarcinogen
CR = Cancer Risk
HI = Hazard Index'
ppm = parts per million
ppb = parts per billion
ND = Not Determined
NOTES:
(1)
(2)
(3)
Risk associated with maximum soil concentration. .
Average and maximum soil concentration is obtained from surface and subsurface soil data at the LB&D and RFI properties.
Totals are slightly different from the values of 9.1 X 10-3 and 270 reported in the RI Risk Assessment because the final list of COCs is slightly
different in the RI report versus the FS report and ROD.
-------
various interim remedial measures have been implemented since
1984 to limit potential.human exposure to contaminants and to
reduce LB&D site hazards. These measures included removal of
waste drums, excavation and disposal of contaminated soil and
replacement with clean soil, and sealing of 2.75 acres with a
chip and asphaltic-seal mix. The LB&D risk assessment considered
LB&D site conditions that existed following these interim
remediation activities and is referred to as the Current
Conditions Scenario (CCS). In addition, a second risk scenario,
termed the Future Use Scenario (FUS) evaluates risks associated
with hypothetical future industrial land use at the LB&D site.
In comparison, the CCS evaluates only soil and Coyote Creek
sediment exposure pathways for a child receptor (a 6 year old
trespasser is most conservative case), whereas the FUS includes a
groundwater exposure pathway and additional receptor populations
(SJSU.student, adult gardener, on-site worker, and average adult
resident) as well as a child. The combined Current Conditions
and Future Use Scenarios evaluated 12 different exposure cases.
The exposure pathways evaluated under the CCS for a child
receptor were on-site soil ingestion and dermal absorption, and
Coyote Creek sediment ingestion and dermal absorption. The SJSU
student, adult gardener, on-site worker, and average adult
receptors were only evaluated under the FUS exposure pathways.
The soil exposure pathways evaluated under the FUS for the child,
SJSU student, adult gardener, on-site worker and average. adult
receptors were contaminated soil inhalation, ingestion~ and
dermal contact. In addition the following exposure pathways were
evaluated for the SJSU student, adult gardener, .and average adult
receptors: off-site dermal adsorption of soil contaminants, off-
site inhalation of wind-borne contaminants, and off-site soil
ingestion. .
Soil gas emissions from the VOC shallow groundwater contaminant
plume were evaluated as a potential inhalation health risk
because the groundwater contaminant plume extends beneath
residential areas. The health risk associated with VOC emissions
was evaluated by estimating the magnitude of emissions reaching.
the living spaces and then performing risk calculations.
Exposure risks were estimated using seven cases based on varying
input parameters including groundwater chemical concentrations,
soil porosity, housing air exchange rates, and housing
configurations.
6.2.2
Exposure Assumptions
The CCS assumes that only the on-site trespassing child receptor
would receive any significant exposure (inhalation, ingestion, or
dermal) to soil contamination. Due to the extensive soil
crusting and an asphaltic covering (70% of the LB&D property),
off-site receptors would not be exposed to particulate emissions.
The FUS makes the conservative assumption that the entire LB&D
site would be exposed to limited erosion of soil particles to
off-site receptor locations.
44
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The CCS modeling and exposure data used for a child receptor
assumed a 6 to 10 year old child, weighing 22 kilograms (kg),
exposed for 2/4 years (best estimate/plausible maximum), 24/48
,days per year, and 0.5 hours per day. The soil ingestion rate is
200 milligrams (mg)/day, the sediment ingestion rate is 25/100
mg/day, and the assumed gastrointestinal absorption is 50%/100%.
The FUS makes similar exposure assumptions for a child. The
adult on-site worker, which is the most conservative exposure
scenario, assumed a 70 kg adult, exposed 20/40 years for 240 days
per year, and 8 hours a day. The assumed soil ingestion rate is
100 mg per day with a gastrointestinal absorption of 50%/100%.
6.3
TOXICITY ASSESSMENT
The primary source for all toxicity information, such as verified
chronic reference doses (RfDs) and cancer potency factors (CPFs)
was the EPA risk assessment database Inteqrated Risk Information
system (IRIS). The risk assessment generally used those toxicity
values presented in the Health Effects Assessment Summary Tables
(HEAST; EPA 1989). If an RfD was not available from IRIS,
Acceptable Daily Intakes (ADI) were developed or obtained .from
other sources, such as the National Academy of Sciences or the
World Health Organization.
CPFs have been developed by EPA'S Carcinogenic Assessment Group
for estimating excess lifetime canc;er risks associated with
exposure to-potentially carcinogenic chemicals. CPFs, which are
expressed in units of (mg/kg-day)-l, are multiplied by the
estimated intake of a potential carcinogen, in mg/kg-day, to
provide an upper-bound estimate of the excess lifetime cancer
risk associated with exposure at that intake level. The term
"upper-bound" reflects the conservative estimate-of the risks
calculated from theCPF. Use of this approach makes
underestimation of the actual cancer risk highly unlikely.
Cancer potency factors are derived from the results of human
epidemiological studies or chronic animal bioassays to which
animal-to-human extrapolation and uncertainty factors have been
applied.
RfDs have been developed by EPA for indicating the potential for
adverse health effects from exposure to chemicals exhibiting
noncarcinogenic effects. RfDs, which are expressed in units of
mg/kg-day, are estimates of lifetime daily exposure levels for
humans, including sensitive individuals. Est~mated intakes of
chemicals from environmental media (e.g., the amount of a
chemical ingested from contaminated drinking water) can be -.
compared to the RfD. RfDs are derived from human epidemiological
studies or animal studies to which uncertainty factors have been
applied (e.g., to account for the use of animal data to predict
effects on humans). These uncertainty factors help ensure that
the RfDs will not underestimate the potential for adverse -
noncarcinogenic effects to occur.
45
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6.4
RISK CHARACTERIZATION
The LB&D risk assessment and .RI Addendum No.3 evaluated the
health .risks associated with the primary exposure sources: the
contaminated soil at the LB&D property and the shallow
groundwater plume. Although a specific risk assessment was not
performed for each of the various materials. comprising OU-1, an
evaluation is presented below of the general risks associated
with the various materials.
6.4.1
Soil
6.4.1.1
Soil with Bealth-Risk-Based COCs
LB&D PrODertv. Soil at the LB&D property is comprised of
shallow, deep, and stockpiled soil as discussed below.
shallow soil. The operation of the LB&D facility required large
areas for the storage of open and leaking drums that contained
residues of hazardous substances. Thus, the most significant
contamination occurs in the shallow soil (the upper 4 feet bgs).
. The shallow soil also exhibits heterogeneity in soil contaminants
and concentrations. Under the CCS, the greatest exposure to a
trespassing child occurred through shallow soil ingestion (1.8 x
10-6/2.1 x 10-4). For the FUS, greatest risk for exposure to the
shallow solI was to the on-site worker through direct contact
(with a carcinogenic risk of 1.4 x 10-4/9.1 x .10-3 and a hazard
index (HI) of 6.9/270). The contaminant contributing the most to
the CCS and FUS excess risks was PCBs.
deep soil. The deeper soil (greater than
contamination in various. isolated areas.
access by potential receptors, the deeper
for potential risks.
. stockpiled soil. The stockpiled soil was excavated from the
upper 3 feet of the LB&D site to allow construction of the LSGTF
Treatment Facility. Initial geotechnical borings and subsequent
analytical testing of the excavation bottom detected elevated
concentrations of health-risk-based COCs, primarily PCBs.
Subsequent visual characterization, sampling, and analyses of the
stockpiled soil indicated similar contaminants as detected around
the former processing facility but, typically, at lower
concentrations. The stockpiled soil investigation provided
evidence that there is significant heterogeneity in the presence
and concentration of contamination at the LB&D site. The
stockpiled soil presents a potential risk to trespassing
individuals over the long term should the LB&D site not be
maintained. currently, the stockpiled soil is covered and the
LB&D s~te fenced, thus the stockpiled soil is not considered to
have immediate public health risk. ..
4 feetbgs) contains
Because of the limited
soil was not evaluated
Neiqhborina ProDerties. Testing of the RFI property encountered
contaminant concentrations within the EPA risk range and less
than concentrations 6.4.2 typically encountered on the LB&D
46
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property. Based on soil sampling conducted along the perimeter
of the LB&D site, there is a likelihood that the sidewalk areas
adjacent to the LB&D property have soil contamination exceeding
the risk-based cleanup standards developed in the FS. Because
both the RFI property and the adjacent sidewalk area are covered
with either concrete or asphaltic-concrete there is minimal
current risk since the soil is not exposed. There could,
however, be health risks if the soil were to be exposed in the
future.
6.4.1.2
principal Threat Soil
The principal threat (VOC contaminated) soil, if allowed to
remain in place, could impact the groundwater. Thus, the'risk
associated with the principal threat soil is primarily through
the groundwater exposure pathway. Based on this exposure'
scenario, there are no risks associated with the CCSs. The FUS
groundwater exposure risks for the child and average adult are
1.5 x 10-3/5.0 x 10-2 and 6.9 x 10-3/6.3 x 10-1, respectively.
The FUS HI estimates for the child and average adult are 93/580
and 61/320, respectively.
Health risks were not evaluated for the VOCs present in the
Principal Threat soil. It is unlikely that the VOCs in princ~pal
threat soil would significantly increase the level of risk posed
by the other COCs in principal threat soil under the soil
exposure pathways described in section 6.4.1.1. However~ it is
, possible that the VOCs would pose a risk to indoor airspaces of,
potential future dwellings constructed directly above the
principal threat soil.
6.4.1.3
Vicinity/Backqround Soil
Shallow samples (a total of 14) were collected from off-site
locations to serve as background data. PCBs were detected at
levels in excess of the 10-6 risk level in one sample. DDE., the
most frequently occurring pesticide, exceeded the 10-6 risk level
in 7 samples. The presence and concentration of BNAs was not
considered significant. The only significant metal detected
offsite was lead, at a concentration of 642 ppm, which exceeds
the cleanup standard of 500 ppm.
6.4.1.4
coyote Creek Sediments
Exposure through ingestion and dermal contact with sediments from
coyote Creek was considered a pathway for the CCS only. Under
the CCS, dermal contact with the sediments resulted in risks of
2.0 x 10-7/1.7 X 10-5, attributed primarily to PCBs. The total
sediment exposure His (attributed primarily to PCBs) were 0.1 for
the best estimate HI and 3.5 for the plausible maximum HI. As
part of the initial public Health Evaluation conducted at the
LB&D site, the adjacent community Garden produce was sampled.
Risk characterization of the produce did not indicate that
consumption of the produce was a significant exposure pathway.
47
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6.4.2
Water
Groundwater (Zones Athrouah D). Because contamination is
currently only detected in the shallow aquifer (Zones A/B) and
not in the deeper aquifers (Zones C and D), the groundwater
pathway was not evaluated for the CCS since there is no current
exposure through ingestion. The risk assessment did assess
shallow groundwater contamination risks under an FUS because of
the high VOC concentrations in the shallow groundwater and the
potential for future exposures. The risk assessment is
applicable to the deeper aquifers in the event that contamination
is found in Zones C and D. Groundwater risks were evaluated
through groundwater ingestion, inhalation and dermal exposures
routes. The most significant exposure occurs through groundwater
ingestion. . .
carcinogenic. The greatest exposure risk for groundwater
. ingestion was for adults using the best estimate/plausible
maximum (1.2 x 10-3/2.9 x 10-2). The total groundwater exposure
risks (including inhalation) for children and the average adult
were 1.5 x 10-3/5.0 x 10-2, and 6.9 x 10-3/6.3 x 10-1,
-respectively.
noncarcinogenic. In terms of the HI, the greatest exposure risk
for groundwater ingestion was for children (91/560) and is
attributed-to antimony. The total groundwater exposure risks
(including inhalation) for children and the average adult were
93/580, and 61/320, respectively.
Coyote Creek. The FUS exposure-route evaluated only the
consumption of fish. Evaluation of the risks of consumption of
fish from Coyote Creek was also performed during the initial
Public Health Evaluation.
carcinogenic. The FUS evaluated the risks 9f fish consumption
for children and the average adult, and the levels were 1.2 x 10-
4/2.3 X 10-4, and 7.3 x 10-4/2.5 x 10-3, respectively.
noncarcinogenic. A single HI of 52/32 was calculated for the
child and adult receptors, respectively, for the fish consumpt~on
exposure pathway. -
6.4.3
Air
Evaluation of air risks consists of soil gas (vapor emissions)
and surface air and dust from the LB&D site.
soil Gas. Soil gas emissions which could potentially emanate
from the shallow groundwater contaminant plume were evaluated.
VOCscould potentially migrate from the shallow groundwater
through the vadose zone and enter into overlying residences. The
risk evaluation concluded that neither the current TCE and vinyl
chloride chemical concentrations beneath residential housing nor
the highest concentrations of TCE and vinyl chloride, likely to be
encountered beneath residential areas once the groundwater
48
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extraction/treatment system is operating, indicate risks outside
the EPA's acceptable risk range. In addition, evaluation of the
potential exposure risks posed by VOC emissions for residences.
with walk-in basements does not indicate potential 'exposure risks
exceeding the EPA acceptable risk range.
surface Air and Dust. Under the CCS, inhalation was not
considered a pathway because of the limited exposure. Thus, only
future exposure scenarios evaluated surface air and dust.
carcinogenic risks. The FUS soil inhalation risk was greatest for
the on-site worker (1.8 x 10-4/1.3 x 10-2; best estimate/upper
bound exposure). The inhalation pathway for vapors generated
during the domestic use of shallow qroundwater was greatest for
the average adult (5.0 x 10-3/5.2 x-~) and exceeded EPA's
acceptable risk range.
noncarcinogenic risks. In terms of the HI, the on-site worker
had the greatest risk (0.016/1.4) posed by inhalation of soil
contaminants. The average adult risks posed by inhalation of
VOCs through domestic water use were 2.4/11. The contaminant
contributing most significantly to this risk is 1,1-
,dichloroethene.
6.4.4
Conduits
There are two types of conduits at the LB&D site, vertical
conduits and horizontal conduits.
Vertical Conduits. Vertical conduits include all types of wells
that could potentially transfer contaminants from the shallow
aquifer to deeper aquifers. The vertical conduits pose a
potential drinking water risk~
Horizontal Conduits. The horizontal conduits include utility
lines (e.g. sewer lines) underlying the LB&D site which could
contain contaminated residues. The horizontal conduits are
buried and, because of their limited exposure, they pose minimal
health risks. The conduit residues are addressed in Section
6.4.6.
6.4.5 structures/Debris
The structures/debris consists of the warehouse, pavements/ pads,
surface drains, septic tank, and other debris. They have minimal
contamination associated with them, however, they could be
potential conduits (i.e. .surface drains and septic tank). The
risk due to direct contact was not evaluated because of the
limited contamination.
Buildinas/EauiDment. The warehouse that will remain upon
completion of the ongoing structures removal action, is not
contaminated and poses no health risks.
49
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Pavements/Pads. The chip and, asphaltic-seal covering is
uncontaminated. Portions of the concrete building pads may
contain limited contamination.
'Surface Drains. The concrete surface drains have the potential
to act as horizontal conduits, but will pose minimal risk
provided the drain residues are removed.
septic Tank. , The septic tank has the potential to act as a
conduit but poses minimal risk provided the residues are removed.
Debris Pile and other Debris. Most debris at the LB&D site has
not been tested, but is not expected to pose a significant risk.
The most contaminated structures, the processing facility and its
building pad, were tested and found to contain only low levels of
pesticides and PCBs on their surfaces.
6.4.6
Residues
The residues are comprised of the ash, spent granulated activated
carbon ([GAC] from the SVE system), the contents of the various
conduits and structures, and decontamination liquids and material
(from RD/RA). If not attended to, the residues are expected to
have a similar risk as the risk-based COC soil. However, this
risk can be substantially reduced provided the residues are
contained in drums (thus limiting access), their volume is kept
~o a minimum, and they are disposed at a secure facility.
Contents of Structures and Conduits. The contents of the various
structures and conduits at the LB&D site likely contain
significant concentrations of contaminants and are considered a
potential human health risk and groundwater threat~
~
Incinerator Ash. Based on the elevated concentrations of metals
detected in the incinerator ash, the incinerator ash poses a
significant human health risk.
6.4.7 Uncertainties
Uncertainti~s specific to the LB&D site risk assessment are
grouped into 1) monitoring data gaps, 2) model parameters, and 3)
eXposure or fate models. Monitoring data gaps include the
limited availability of fish from Coyote Creek and limited
ambient air data. Model input parameters for which high
uncertainty exists are numerous., These include contaminant-
specific dermal absorption efficiencies, gastrointestinal
absorption efficiencies of soil contaminants relative to
contaminants in food, daily soil ingestion rate, soil (and
sediment) loading per unit of skin surface area, contaminant-
specific uptake efficiencies for plants, home-grown produce
consumption estimates, actual fish consumption rates, and
estimated off-site soil concentrations. In the absence of
comprehensive ambient air sampling, two air quality models were
used to estimate annual average emissions of contaminants from
the LB&D site. These models have not been field verified.
Estimation of the VOC emissions in residential areas had
50
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uncertainties in soil moisture content, volatilization of
contaminants and building air exchange rates.
6.5
PRESENCE OF SENSITIVE HUMAN POPULATIONS
Although the LB&D site is currently unoccupied, there are
sensitive human populations in close proximity to the LB&D site.
The LB&D site is located in an industrial area and is zoned
industrial. The SJSU stadium, fields, and student housing are
located to the north; a parking area and community gardens (to be
relocated in the future) are located to the east; and, to the
south and west are industrial-related businesses. Residences and
Kelley Park are located within 0.25 miles of the LB&D site.
Residences are located over portions of the shallow groundwater
VOC plume perimeter.
6.6
PRESENCE OF SENSITIVE ECOLOGICAL SYSTEMS
. Due to the urban location of the LB&D site, ecological risk is
presently limited. The ecological effects associated with the
LB&D site contamination are presently associated primarily with
two effects: 1) if the LB&D site were converted to an unpaved
park or open space, potential ingestion of soil contaminants by
birds and; 2) contamination of Coyote Creek with soil
contaminants released from the LB&D site through storm runoff.
Quantitative evaluation of the effects of bird ingestion of soils
is very difficult due to a lack of information regarding expected
soil consumption rates for urban bird species. Therefore, a
quantitative analysis of this possibility was considered. beyond
the scope of the risk assessment and was not performed.
. .
LB&D site contaminants that could potentially be released into
coyote Creek through the East Alma storm sewer may become
bioconcentrated in fish, insects, or other aquatic organisms
which serve as important food supplies to wildlife in the area.
Analysis of Coyote Creek water samples for VOCs, BNAs,
pesticides, PCBs, and metals showed no significant contamination.
However, a sediment sample taken downstream of the LB&D site did
show high P9B contamination. Although high sediment PCB
concentrations correlate with the high concentrations of PCBs
observed in the LB&D shallow soils, the location of this sample
is quite removed from the LB&D drainage area's storm sewer
outfall and little contamination was found in the samples between
the outfall and the Keyes street/story Road overpass. Downstream
transport of these contaminants seems unlikely considering the
lack of any gradational trends from upstream. In addition, the
storm drain serves the industrial area adjacent to the LB&D site.
other point sources in the area (e.g., the story Road landfill)
also could have contributed to elevated levels of pollution found
in coyote Creek. . At present, it appears that Coyote Creek
ecology is more affected by urban land use and runoff than by
LB&D runoff.
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6.7
CONCLUSION
Because a variety of the COCs detected at the LB&D site pose a
significant health risk as carcinogens and/or as noncarcinogens,
and that complete exposure pathways exist, EPA has determined
that remedial action is appropriate for the LB&D site.
Actual or threatened releases of hazardous substances from the
LB&D site, if not addressed by implementing the response action
selected in this ROD, may present an imminent and substantial
endangerment to the public health, welfare, or environment.
7.0
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
Section 121(d) of CERCLA requires, for hazardous substances left
on site at the conclusion of remedial actions, that the action.
requires a level or standard of control which at least attains
applicable or relevant and appropriate federal or state
environmental or public health requirements (ARARs), except in
certain limited circumstances. To ensure protection of human
health and the environment, remedial alternatives must attain or
exceed ARARs, or qualify for a waiver. Section 121(d) (4)
provides a list of the six potential waivers.
ARARs-may include the following:
- Any standard, requirement, criterion or limitation
under federal environmental law;
- Any promulgated standard,. requirement, criterion or
limitation under a state environmental or facility-
siting law that is more stringent than the associated
federal standard, requirement, criterion or
limitation. .
A requirement may be either "applicable" or "relevant and
appropriate," but not both. Applicable requirements include
requirements that specifically address a hazardous substance,
pollutant, contaminant, remedial action, location, or other
circumstance at a CERCLA site. Relevant and appropriate
requirements include those requirements that, while not
"applicable" to a hazardous substance, pollutant, contaminant,
remedial action, location, or other circumstances at a CERCLA
site, address problems or situation sufficiently similar to those
encountered at the CERCLA site that their use is appropriate to
the site.
. .
Substantive requirements are requirements that apply directly to
actions or conditions in the environment. Examples include.
quantitative health or risk-based standards for contaminants.
Administrative requirements are those mechanisms that assist in
the implementation of the substantive requirements (e.g.
reporting, record keeping, permit issuance etc.). While off-site
activities must fulfill both substantive and administrative
52
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requirements, in general, on-site CERCLA actions must comply only
with substantive requirements. '
ARARs are identified from information about specific chemicals at
.a site, specific features of a site location and actions that are
considered as remedies. If an ARAR does not address a particular
situation or does not sUfficiently protect human health or the
environment, nonpromulgated standards, criteria, guidance and
advisories may be considered to guide selection of a protective
remedy. These to-be-considered criteria (TBCs) may be adopted as
enforceable cleanup standards in a ROD.
7.1
TYPES OF ARARs
ARARs fall into three broad categories, based on the manner in
which they are applied at a site. These categories are as
follows:
.
Chemical-Specific - These ARARs govern the extent of
site cleanup. Such ARARs may be actual concentration-
based cleanup standards or they may provide the basis
for calculating such concentrations. In general,
chemical- specific ARARs and TBCs are considered during
the risk assessment process. Chemical-specific ARARs
may be superseded by the risk-based levels for a site
if they are not sufficiently protective of human health
and the environment. Examples of chemical-specific
ARARs include groundwater maximum contaminant levels
(MCLs) and air emission standards.
.
Location-Specific - These ARARs are restrictions placed on
the concentration of a hazardous substance or of activities
planned because of natural or man-made site features or
environmentally sensitive areas. Examples of restricted
locations include 100 year floodplains or historic
properties or landmarks.
Action-Specific - These ARARs affect the implementation and/
or operation of remedial actions. These technology or .
activity-based requirements determine how a remedial action
must be performed. Examples of action-specific ARARs
include RCRA generator requirements and land-disposal
restrictions.
.
7.2 .SITE SPECIFIC ARARs
Table 7.1 lists and explains ARARs for the selected alternative.
Because no potential chemical-specific or location-specific ARARs
have been identified, the table consists of only action-specific
ARARs. The FS contains a detailed description of the potential.
ARARs and TBCs for Alternatives 1 (No Action) and 3 (Excavation
and Off-site Disposal).
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Table 7.1
ARARs FOR SELECTED REMEDY
LORENTZ BARREL " DRUM SITE
San Jose, CaUfornia
Requiremellt8
Commellt8
ACTlON-SPECInC
Toxic SubstaDc:ca Control Act (TSCA)
{l5 USC 2605 leD
(40 CFR Part 761 Subpart D)
Non-liquid PCBa at CODCentrations of 50 ppm or greater after 1978 shall be
dillpOlCd of in a TSCA-approved incineralOr, a TSCA IaDdfill, or shall be
treated with . TSCA-approved alternative method with equivaleD1 performance
10 incineration.
Status: . Applicable
Standarda Applicable 10 GCDCratora of
Hazardous Waste
(22 CCR Div. 4.5, Chapter 12)
Generation of bazardoua waite &hall comply with the generator &laDdards. A
waste cJaaaification of the coD18miDated aoils and dzummed Waste on site is
required 10 determine if the waite is RCRA hazardous, DOn-RCRA hazardous
or DOn-hazardoua.
Status: Applicable
LaDd Dispo&al Rcalrictions
(22 CCR Div. 4.5, Chapter 18)
-
LaDd dispoaal te8ttictiooa (LDRs) are applicable 10 CERCLA rcapoo&e actions
if the rcapoo&e action con&titutes IaDd disposal or 'placcmeD1' of restricted
RCRA bazardoua waste or DOD-RCRA hazardous waste. Placement into a
IaDd disposal unit occura when: I) RCRA or DOII-RCRA hazardous waites are
moved from ODe d"lineated area of colltaDliDation (AOC) into anocher AOC or
movemeD1 occura from the AOC 10 . taDk and is redeposited into the lime
AOC (such 81 the situation in the stabilizationlaolidification treatmcD1
alternative). If the rcapoo&e action requires placement or dispoaal, an
application for a treatability variaDce fiom LDR "best demODlllrated available
technology' (BDAT) &laDdards may be appropriate. LDRs are DOt applicable
10 wxli8turbed lOils or investigatioa-derived stockpiled aoil as long as these
aoils remain within the ODe AOC.
Status: Applicable
Soils contaminated with RCRA waste code DOO6 (cadmium), DOO7
(chromium), DOO8 (lead). and DOO9 (mercury) have waste extract treatment
&taIIdanIa DOt.1O be exceeded of I ppm (cadmium), 5 ppm (chromium),
0.2 ppm (mercury), 8Dd 5 ppm (lead) in DOn-wastewater (22 CCR 66268.35).
Nonliquid RCRA hazardous wastes containing halogenated organic
colllpClUDda (HOCs) listed in Appeudix m of Chapter 18 (California list
wastes: PCBs, IOlventa, pesticides, dioxins) mixed with RCRA hazardous
waste. are subject 10 laDd dispoaal prohibitions. Waste. coniaining HOCs in
total concelltt8tion greater than or equal 10 1,000 mglkg (1000 ppm) are
prohibited from IaDd disposal. RCRA waste containing 1,000 ppm HOCs
catabliahe. incineration with a destruction rate of efficiency (DR£) of 99.99$
II the treatmcD1 standard (22 CCR Div. 4.5 66268.42.a.2).
Non-RCRA hazardous waste. (generally, wastes exhibiting characteristics
Wlique 10 California regulations 88 defined in 22 CCR Div. 4.5 66261.101,
but DOt a listed or characteristic hazardous waste set forth in 40 CFR. 261)
containing the foUowiII(.COfttJImilUlnl& are subject 10 LDRs: PCBs, metals or
metal compouuds identified in 66261.24(a)(2), and organic hazardous
constituCD18 88 defined in aectiOD 66260.10. Solid hazardous wastes
containing organic. IDUIt meet the treatment 8tandards spec:ified in aectiOD
66268.113 for allowable IaDd dispoaa.1 (e.g., 64 ppm for volatile organics; 435
ppm for aemi-volatile organics); or incineration with a DRE of 99.99$; or an
alternative treatment method approved by DTSC.
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Table 7.1 (Cont'd.)
ARARs FOR SELECTED REMEDY
RequiremeD18 CommeD18
LaDd DiaposaJ Resrrictioas ScaDdanIa are promuJaated for IIOn-RCRA bazardou. wore IOlidi cODtliaing
(22 CCR Div. 4.5, Chapter 18) (COIIt'd.) HOC. aDd for DOn-RCRA hazardoua wute IOlida cOlltliDing organic.. An
exemption ia provided to cleanup activitie. from the land di8poaal probibition
for DOD-RCRA hazardous waste IOlida """...;..;..,1,000 ppm HOC. (22 CCR
Div. 4.5 66268.32.11.3). The atandarda provided for DOD-IlCRA hazardous
wutc IOlids colltaiaiua organics with the wllSle coDStilUe1ltS are 1 $ oU aDd
greaae, 64 ppm VOC., aDd 435 ppm aemi-volatile. OptiOI1l are provided in
lieu of theae ataDdarda throuJh the \&Ie of incineration with a DRE of 99.99 $
or a treatmell1 method with an equivalell1 performance.
Non-RCRA bazardoua wore IOlida cOlltliDing organic. which contain
hazarcIoua wore metala IIII&It meet the treatmell1 atandarda for DOD-RCRA
meta1-coII1aiai IOlid wastes (i.e., chromium m (560 ppm), lead (67 ppm),
aDd nictel (20 ppm».
~mi...~ aoiI from cleanup actio. may receive a LDR variaDCe from
DTSC for DOD-IlCRA hazardous wutc or a variaDcc from both EPA aDd
DTSC for RCRA hazarcIoua waatc if the apecified treatment level can DOt be
achieved or the treatment tcehDology ia DOt appropriate (22 CCR Div. 4.5
66268.44).
Poder-Colope-Watcr Quality COIIIrOI Act 1bia IOCtiOD eallbliahea the development of well deSlNCtiOI1 ataDdarda to
(Well DesuuctiOI1 StaDdarda Section 13801) protect Jt'OUIIdwatcr from improperly abandoned wells (e.g., vertical conduits
for the migration of cont.m;IUI"'~). The poasible presence of abandoned wells
Swus: Applicable aDd utility linea located at thia site may aerve as vertical conduits for
CC)ftt8m;IUI".a. The locar implemeDtltion of the California Well Standards
(Bulletin 74-90) through the SaDtI Clara Valley Well Ordiaance require the
removal of theae vertical conduits, as weD as prescn"be aealing materials aDd
grout placement methoda foDowing removal.
Bay Area Air Quality Management Disrrict Local air poIlutioa COUIIOI nile. aDd reguiatioDS are eatabliahed to achieve and
(BAAQMD) Rule. aDd Regulations maintain Itate aDd federal ambiell1 air quality IIaDdarda throuJh the federally
RegulatiOI1 8, Rule 15 approved State ImplementatiOI1 Plan (SIP). BAAQMD regulatiOl1llimit
Regulation 8, Rule 47 emissioDS through limitatiol1l or ataDdarda placed 011 particulate matter
emission rates aDd CoaceniratioDS, visible emissions aDd opacity, odorous
SWUS: Applicable aubataDCe., aDd organic compounds (ReguiatiOI1 8). :Regulation 8, R1I1e 15.
lpeCifiea the typea of uphalt which may be used aDd the percent of petroleum
IOlvent they may contain in paving material or in paving aDd maintenance
operaIiOl1l which ia applicable to the a1tcrostivea involving capping of wllSle
011 lite; aDd R1I1e 47 applie. ataDdarda to air srripping aDd .oil vapor
eX1tllctiOD operatiol1l to limit emiasioDS of organic. tompoullda, aDd lpeCities
that any air llripping aDd aoiI vapor eX1tllctiol1 operatiOl1l which emit benzene,
vinyl chloride, petChloroetbyleoe, methylene chloride aDdIor trichloroethylene
muat be vea&ed to . COIItro1 device to reduce emil8i0l1l by at Ieu& 90$ by
weight but lpeCifiea an exemption from the nile for operatiol1l with total
.,.,,;...;on, of leaa than 1 pouDd per day of the above five C!nnt.8m;IUIntJ .
Regulation 8-47-302 apecifie.1he threshold level of emiaiOl1l (i.e., 15
lbalday) that muat be vented to a scrubber or other c:oatrol device to reduce
the tocal orgaiaic compouDd emissiODS by at least 90 percent by weiJht.
55
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Table 7.1 (Cont'd.)
ARARs FOR SELECTED REMEDY
Requirements Comments
HWCL Closure and Post~losure of Chapter 14 requirements arc applicable to the LB&D site if the waste is a
HazardOus Waste Management Facilities RCRA or lIOo-RCRA hazardous waste and the activity at the site coostibltes
(22 CCR Div. 4.5, Chapter l4) treatment, storage, disposal, or "placement". RCRA hazardous waste disposal
after the effective date of the RCRA requirements (November 1980)
Stab1a: Relevant and Appropriate coastirute. di8poIal. Because dilpoul ofRCRA hazardous waste after 1980 is
I1IIkDown at LB&D, thele requiremell1B are relevant and appropriate. If not
applicable, relevlllt and appropriate closure requiremell1B may be combined to
form a "hybrid closure.' Alternate clean closure and alternate land disposal
closure arc the tWO forms of hybrid closures.
The use of a hybrid landfill closure is appropriate when residual
contsmiDation poles a direct coll1Bct threat, but not a groundwater threat. The
hybrid IaDdfill closure is identical to nonnallandfill closure except that the
cover requiremell1B arc relaxed because the wastes being contsined do not
pole a threat to groundwater, and the cover will adequately address direct
cOll1BCt, surface water, or other threats. Closure would coDllist of: a cover,
which prevema human contact but is permeable to precipitation, limited
loq-cerm management including site and cover maiDtelWlCe, minimal
poundwater monitoring, and the use of property deed aoUce(s}.
(53 FR 51446).
56
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Action-specific ARARs differ from alternative to alternative.
For example, California Hazardous Waste Control Law (state
authorized RCRA equivalent law) closure requirements are relevant
and appropriate for Alternatives 1 and 2 which leave contaminated
soil in-place, but not for Alternative 3 which involves
excavation of contaminated soil. Other action-specific ARARs may
effect the action alternatives (2 and 3) but not Alternative 1.
For example, RCRA generator standards and RCRA land disposal
restrictions, as specified in 22 CCR, Division 4.5, Chapters 12
and 18, are ARARs for Alternatives 2 and 3 insofar as they
involve generation and disposal of hazardous waste. Similarly,
TSCA disposal requirements (40 CFR S761.60) apply to the disposal
of PCB contaminated soil contemplated under Alternatives 2 and 3.
The ARARs for the selected alternative, Alternative 2, are
described in detail below. There are no chemical-specific or
location-specific ARARs for this alternative. Action-specific
ARARs for this alternative include:
.
22 CCR, Div. 4~5, S66264.310 (Landfill Closure Requirements)
- HWCL/RCRA landfill closure is an action-specific ARAR for
this alternative because contaminated soil will be left in-
place without excavation or treatment. LB&D was not a RCRA
regulated facility, therefore RCRA closure is not applicable
but is relevant and appropriate. Because the LB&D site is
most closely analogous to a landfill type unit, the relevant
and appropriate analysis focuses on the landfill closure
requirements of 22 CCR, Div. 4.5, S66264.310 and the
"alternate-landfill" or "hybrid" closure described in the
proposed revisions to the NCP, 53 FR 51446, and in EPA's
ARARs guidance (Volume I, p. 2-20).
The guidance describes the following conditions as
appropriate for implementation of hybrid closure: residual
waste material at a site poses a direct contact threat but
does not pose a threat to groundwater; and, residual
leachate contamination does not exceed health-based levels.
The hybrid closure to address this scenario consists of a
permeable cover to address the direct contact threat and
limited long-term management, including site and cover
maintenance, groundwater monitoring and institutional
controls, including land use restrictions. Conditions at
the LB&D site are such that hybrid closure is appropriate.
Implementation of Alternative 2 would satisfy this closure
ARAR. 1
.
1 TSCA PCB disposal regulations (40 CPR ~761.60) do not impact the hybrid closure as described in alternative 2. These
regulations apply to post-1978 disposal of non-liquid PCBs at concentrations greater than SO ppm. If these regulations were an A~R,
then the long-term management controls required for TSCA chemical waste landfills would need to be addn:ssed for some of the soils
that will be left on site under alternative 2. Because it is not known when disposal of PCBs occurred or what levels were disposed of,
these regulations are not applicable. Further, in accordance with EPA's guidance on remediating PCB contamin~tion at Superfund
Sites, the regulations an: not relevant and appropriate. As stated in the guidance, at sites where RCRA closure IS also an ARAR,
TSCA will not be considered relevant and appropriate because RCRA closure requirements will address the situation. ("Guidance on
Remedial Actions for Superfund Sites with PCB Contamination" (OSWER Dir. No. 93SS.4..Q1), p.47.) However, as stated in the text,
these regulations are applicable to the off-site disposal of PCB contaminated soil that is a separate clement of alternative 2.
57
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8.1
.
22 CCR, Div. 4.5, Chapter 12 (HWCL/RCRA generator standards)
- hazardous wastes generated during the RD/RA, including
contaminated SVE treatment residuals and any other potential
hazardous wastes, shall be managed in accordance with the
RCRA generator regulations (e.g. manifesting, labelling
etc.).
22 CCR, Div. 4.5, Chapter 18 (HWCL/RCRA LDRs) - any
hazardous wastes to be disposed of off-site under this
alternative shall be tested and handled in accordance with
LDR standards. For off-site disposal of contaminated soil
to which RCRA land disposal restrictions would apply, a.
treatability variance, as provided for in 22 CCR, Div. 4.5,
S66268.44 and 40 CFR S268.44, will need to be obtained.
.
.
40 CFR S761.60 (TSCA PCB Disposal Requirements) - in
accordance with these regulations, off-site disposal of the
small amount of stockpiled soil contaminated by PCBs at a
concentration greater than 50 ppm shall be in a TSCA-
approved chemical waste landfill, a TScA-approved
incinerator, or by a TSCA-approved alternative disposal
method. .
BAAQMD Regulation 8 - Rule 47 - emissions from the soil
vapor extraction system must be controlled in accordance'
with this rule. Section 302 of Rule 47 specifies that any
soil vapor extraction operations with VOC emissions greater
that 15 pounds per day must employ a control device which
reduces the total VOC emissions to the atmosphere by at
least 90% by weight. .
.
.
BAAQMD Regulation 8 - Rule 15 - this rule specifies the
tyPes of asphalt that may be used for capping and the
percent of petroleum solvent the asphalt may contain.
California Water Code S13801 and Bulletin 74-90 (Well
Abandonment Standards) - removal of potential vertical
conduits for groundwater contamination by closure of wells
must be performed in accordance with the standards set in
Bulletin 74-90.
.
8.0
DESCRIPTION OF ALTERNATIVES
REMEDIAL ACTION OBJECTIVES
The overall remedial action objective for the
protect human health and the environment from
contaminated materials that are not currently
.OU-2 CD or the AOC for removal of structures,
debris.
final remedy is to
all remaining
addressed by the
sumps, drums, and
58
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specific remedial action objectives for the final remedy include:
Reducing the principal threat of soil contaminants
potentially migrating into and contaminating shallow
groundwater;
Reducing potential exposure to soil contaminants;
Reducing potential exposure to contaminated structures,
debris, and residues;
Reducing potential migration of contaminated shallow
groundwater to deeper aquifers and potential surface water
infiltration; and
Providing advance warning to drinking water suppliers and
residents in the event that VOCs begin significant migration
through conduits or soil gas towards exposure points (e.g.
drinking water wells and confined air spaces of dwellings).
Another Remedial Action Objective for soil gas and groundwater
migration is to eliminate the source of VOCs in the shallow
groundwater. The 1988 ROD for OU-2 already addresses this
objective by requiring that all contaminated shallow groundwater
be extracted and treated to reduce contaminant levels.
"Groundwater extraction and treatment will continually reduce VOC
contaminant concentrations to levels that will greatly reduce
their potential to reach harmful concentrations in dwellings or
deeper groundwater aquifers. Because this remedial action
objective for soil gas and groundwater migration was fully
addressed by the OU-2 ROD, it is not included in this final site
ROD. .
.
.
.
.
.
8.2
SOIL CLEANUP STANDARDS
Soil with Health-Risk-Based COCs. EPA developed capping action
levels (Table 8.1) for soil contaminated with the health-risk-
based COCs. Soil with COCs present at concentrations exceeding
these action levels is subject to the cap described in Section
"8.4.2. The cap action levels presented in Table 8.1 are
identical to the cleanup standards that were presented in Table
2-5 of the FS and were also used to evaluate Alternative 3,
excavation and off-site disposal.
Because there currently are no chemical-specific ARARs for soil,
the cap action levels were developed based on the risk
assessment; and, in the case of lead, on a guidance document. .
criteria used in deriving these action levels included
maintaining a cumulative hazard index less than 1.0, maintaining
an individual cancer risk no greater than 1 X 10-5, and
maintaining a cumulative cancer risk no greater than 10-4 for
direct contact with exposed soil at the LB&D site under a future
industrial use scenario for an on-site worker.
PrinciDal Threat Soil. Any soil that contains contaminants that
threaten to migrate to and contaminate shallow groundwater is
59
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. Table 8.1
CAP AcrION LEVELS FOR SOIL
LORENTZ BARREL " DRUM SITE
San Jose, California
Risk-Based Cap Action Levels(l)
Action Hazard
Levels Cancer Index(%)
Contaminants of Concern (ppm) Basis Risk(%) (Ill)
INORGANICS
Arsenic 23 C Risk 10"5 0.02
Chromium 475 HI N C(4) 0.08.
Lead 500(3) EPA ND NA
Guidancc(3)
ORGANICS
Pesticides
Aldrin 0.8 C Risk 10.5 0.07
Chlordane 2 HI 2 x 10-6 0.09
4,4-DDD 10 HI 2 x 10-6 0.05
4,4-DDE 10 HI 2.5 x 10-6 0.05
-
4,4-DDT 10 HI 2.5 x 10-6 0.05
Dieldrin 0.8 HI 10.5 0.04
Endosulfan 1.6 HI NC 0.08
PCBslDioxin
PCBs (Total) 1.7 C Risk 10.5 0.45
2,3,7,8-TCDD (Eq.)(ppb) 0.086 (ppb) C Risk 10"5 NA
TOTAL: :j~111j~j~~I~1~11~~~j~1~~~~~~~~i~i~1~~r~1ill~~~j~j~t~~i~~~~~~~~~~jj~~ij1I~~1~i~j~~j~~1ill1~~1~~~~~~jjj~~~~~~~~j~ 6 x l(T5 0.98
LEGEND: .
NA = Not Applicable
NC = Nonc:arcinogen
HI = Hazard Index
ND = Not Determined
C = Carcinogen
ppm = parts per million
ppb ... parts per billion
NOTES:
(I)
(2)
Action levels are based on the following cancer risk, HI, and lead concentration:
. Individual cancer risk not to exceed 1
-------
considered principal threat soil. Based on RI data, the
principal threat soil is limited to soil contaminated with VOCs
adjacent to former sumps. EPA has adopted the RWQCB recommended
cleanup level of 1 ppm total VOCs for principal threat soil. EPA
assumes, based on engineering experience, that the health-risk-
based COCs do not pose a threat to groundwater at the
concentrations found during the.RI.
8.3
COMPLXANCE BOUNDARXES
Any contaminated soil at the LB&D site that exceeds cleanup
standards is subject to the soil cleanup remedy that is selected
in this ROD. For the purposes of estimating costs, especially
for Alternative 3, EPA assumes that all surface soil down to a
depth of four feet bgs exceeds cleanup standards (Table 2-5 in
the FS) for PCBs, and possibly for other contaminants. EPA also
assumes that soil beneath' City of San Jose sidewalk area located
adjacent to the LB&D property is contaminated. These assumptions
.are based on the detailed characterization of soil representative
of the drum storage area and on lack of controls for runoff from
the LB&D property during ~he former LB&D facility operations.
contaminated soil at depths greater than ten feet bgs are not of
concern for direct exposure health risks because of the low
likelihood that any of this soil would ever be exposed at the
surface. Therefore, the vertical compliance boundary for
excavation under Alternative 3 is 10 feet bgs.
There is no exact vertical compliance boundary for principal
threat soil. EPA assumes that VOCs migrated deeper than the COCs
present in former sumps, and that they are present at depths
greater than ten feet bgs. All principal threat soil down to the
shallow groundwater table, approximately 20 feet bgs, will be
ad~ressed by the SVE treatment system that is selected in this
ROD. compliance monitoring for verifying cleanup of principal
threat soil will include direct. measurements of VOCs in soil
samples.
Figure 8.1 shows a map of soil contamination at the LB&D, RFI,
and adjacent city sidewalk area properties. The map indicates
the various depth levels at which contamination exceeds cleanup
standards for both soil with health-risk-based COCs (applicable
only to Alternative 3 analysis) and principal threat soils.
Table 8.2 provides the estimated amounts of soil exceeding
cleanup standards for both types of contaminated soils. Besides
providing a total weight in tons for all contaminated soils,
.including principal threat soil and soil that exceeds the TSCA
action level for PCBs, the table also indicates the individual
weight of principal threat soil containing VOCs and the
individual weight of soil that exceeds the TSCA action level for
PCBs. The information relevant to Alternative 2 analysis is
limited to the column for principal threat soil and the
stockpiled soil in the column for soil contaminated with greater
than 50 ppm PCBs. All of the information in this table is
directly relevant to the analysis of Alternative 3.
61
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Soutll Tenth Street
a-
N
i
i
i
"" "" "" "" "" "" "" "" "" "" "" I "" "" "" ""
'" ~ ~ '" '" '" '" '" ,;;;...,,~ \"",0. '" '"
"'~~"'''' ~ '" '"
"""""""" """". "" ""
"""""""""" "" ""
"~' ~ '" '" '" " '" '"
Prlnclp.' T~..t 901/9""", AI.. 90.
'" '" '" ~~~.. ". . '" '" G I
~ "''''''''''''''''''''''''''''''''''''''''''''''''' f
"""" ~ ~~~~""""""""""~""""""
LB&D PROPERTY
~~~.. "'''''''''' "''''''''''~''''''
CPwCII No. .n-ot-o34l .
.~ .~ ~~.~~~ ~~~~~~..~
"" ""~"""""" """"""""""""""
"" "" ""~""""""""""~""""~
~""""""""""~""""""""""""""""~""""~
"" ~. ~ "" "" "" "" ~ ~ .
. .
MAP OF SOIL CONT AMINA TION ABOVE CLEANUP STANDARDS
~
rt~
~~.
LEGEND
- ~.....
F...., Dr"
~F-
~ 0'-4' ........ 8aII
~ -. ,,- aurt-
~ 4'-11' -- ,,-
~ ...- 8aII
ITTTTl1 4'-10' -. ,,-
ILUlJI -,... 8aII
r-::?I ,.,.,... ThrMtt
IL.-I ..... AI.. 801
o 25 50
.
SCAlf IN fEET
FIGURE
8.1
-------
. Table 8.2
ESTIMATED AMOUNT OF SOIL EXCEEDING CLEANUP STANDARDS
LORENTZ BARREL & DRUM SITE
San Jose, California
Depth Princi~ SoU Contaminated with AU Contaminated
(bgs feet) Threat SOU 1) (to_) PCBs > 50 ppm (to_) SOUO) (tom)
().4(4) 1,945 1,690 51,880
4-5(S) 485 130 1,600
5-10(6) 2,430 750 6,365
lO-20(7) 4,860 - 4,860
Stockpiled Soil - 55 1,080
TOTAL (I): 9,720 2,615 65,785
LEGEND:
bgs - below ground surface
ppm - parts per million
NOTES:
. (l)
(2)
(3)
(4)
Soil with total VOC concentrations exceeding 1 ppm.
Includes, but no, limited to, principal threat soil and soil contaminated with PCBs> 50 ppm.
Density (in-place) of soil is 100 pounds per cubic foot (pet); density (excavated) of soil is 80 pef.
0- 4 feet - includes entire site (6.72 acres), entire sidewalk area along East Alma Avenue and 15O-foot-Iong
sidewalk area along South 10th Street. .
(S) 4 - 5 feet - includes volume around five soil boring (identified as SBI5, SB26, SB29, ,SB38 and SB39 in the
RI Report) locations (465 CY) and volume in Sump Area (720 CY).
(6) 5 - 10 feet - includes volume around two soil boring (identified as SB38 and SB51 in the RI Report) locations
(1,115 CY) and volume in Sump Area (3,600 CY). .
(7) 10 - 20 feet - approximately 50 percent of Sump Area is considered to have principal threat soil (3,600 cy).
(8) Total contaminated soil includes the CODtAmmlllt~ soil with PCBs> 50 ppm and the principal threat soil.
63
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soil Gas Monitorina ComDliance Boundaries. Monitoring of soil
gas for VOCs will be limited to the residential areas that are
near wells with groundwater -concentrations of vinyl chloride or
TCE that exceed maximum contaminant levels (MCLs). Such wells
would be within the shallow groundwater plume boundaries, near
the leading edges. Vadose zone sampling will be done right
beside or just beneath (using diagonal probes) representative
residences near the affected wells.
Groundwater MonitorinQ com~liance Boundaries. Monitoring of the
grounqwater in the Zones C and D aquifers will include all
existing wells installed into these zones by EPA during the RI,
the SJSU South Campus well and the Kelley Park well. Well
samples will be analyzed as long as a significant threat of
migration is posed by contaminants in the shallow (Zone B)
aquifer. This threat will eventually be eliminated by the
shallow groundwater extraction and treatment required by the 1988
OU-2 ROD, as implemented through the 1990 CD.
For five year reviews, it may be necessary to analyze SJWC wells
and other nearby wells for soil COCs that are not routinely
analyzed by SJWC or other well owners. Such analyses would be
necessary in the event that soil COCs are detected in the Zone B
aquifer during operation of the shallow groundwater extraction
and treatm~nt system. All wells in the vicinity of the LB&D site
are already analyzed for VOCs on a routine basis.
Vertical Conduit ComDliance Boundaries. The final remedy will
address all non-essential vertical conduits that are within or
near the shallow groundwater plume boundaries and have been
identified as potential conduits of primary concern by EPA inRI
Addendum No.4. These conduits include abandoned agricultural
wells (e.g., Well Nos.' 1, 130, 192, 199) and the former SJSU
South Campus well. Conduits to be addressed by the final remedy
also include any monitoring wells installed by EPA during the RI
that are no longer es~ential to the operation and oversight of
the shallow groundwater extraction and trea~ment system.
ComDliance Boundaries for Other Materials. All, other materials
involved in the final remedy are located at the LB&D property.
8.4
REMEDIAL ACTION ALTERNATIVES
FOllowing a preliminary screening of soil cleanup technologies
and process options, EPA developed seven cleanup alternatives in
the FS to address the ~emedial action objectives for the LB&D
site. These alternatives included no action, hybrid closure,
excavation and off-site disposal, limited action,
solidification/stabilization, soil washing, and off-site
incineration. Only the first three alternatives survived the
screening process through detailed analysis.
64
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8.4.1
Alternative 1: No Action
The No Action alternative would only address groundwater in
deeper aquifers~ All other materials of concern for the final
remedy would not be addressed. Thus, the remedial action
objectives for the LB&D site would not be met. The No Action
alternative was included as a basis for comparison as required by
the NCP.
The No Action alternative does involv~ the semi-annual monitoring
of six Zone C aquifer wells and one Zone D aquifer well until the
shallow groundwater (Zone B) extraction system reduces VOC
contaminant concentrations to levels that no longer pose a
significant migration threat to the deeper aquifer zones. The
status of the LB&D site would be reviewed every five years. Such
a review would include analyses of groundwater samples for soil
COCs if such contaminants were detected in the Zone B aquifer.
Under Alternative 1, 65,000 tons of contaminated soil would be
left at the LB&D site and would pose a cancer risk of 1.3 X 10-2
to future on-site workers. . The HI for future on-site workers
would be 270. . About 9,700 tons of this soil would also pose a
threat to shallow groundwater because of the presence of VOCs.
In addition, a contaminated sewer line, septic system, drums of
incinerator ash, and some contaminated pavements and drains would
be left at the LB&D site and would pose health threats from
direct exposure. .
Alternative 1 has no capital costs. The present worth cost of
$853,174 is based on 30 years of groundwater monitoring at an
annual cost of $55,000.
8.4.2
Alternative 2: Hybrid Closure Cap
Alternative 2 involves removing almost all non-soil materials
contaminated with LB&D COCs and covering all remaining.
contaminated materials (primarily soils) with a cap; Because
contamination will be left at the LB&D site following
implementation of Alternative 2, five-year reviews would be
performed in accordance with Section 121(c) of CERCLA. In
addition, Alternative 2 will require land use restrictions to
prevent well construction (for water supply purposes) in source
areas that remain contaminated and deed restrictions for those
properties (LB&D, RFI, and the" adjacent sidewalk area belonging
to the City of San Jose) that contain contaminated soil exceeding
cap action levels. Restrictions will prohibit residential
development and will limit industrial development to activities
that do not breach the integrity of the cap and do not mobilize
the soil contaminants. Restrictions will also preclude
: excavation, other than temporary subsurface work beneath the cap
and will require complete restoration of any disturbed fill or
cap once any such temporary work is completed. "
Groundwater. Additional protection from future potential
exposure of humans to contaminated groundwater will be provided
65
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by a mechanism for early warning in the unlikely event that
shallow groundwater contaminants migrate towards the deep aquifer
that is used for drinking water. Both the intermediate and deep
aquifers will be monitored for VOCs on a semi-annual basis to .
alert the community if VOCs are detected. Such monitoring would
continue for 30 years or until concentrations of VOCs in the
shallow ,groundwater no longer pose a threat to the deeper
aquifers~ '
Vadose Zone soil Gas. Ongoing shallow groundwater extraction and
treatment is expected to reduce VOC source concentrations in the
shallow groundwater contaminant plume to the extent that VOCs
will not pose an indoor air threat to people inside dwellings
over a sustained period of time (e.g., 30 years). While the risk
assessment (RI Addendum NO.3, URS Consultants, Inc., 1992)
indicates that probable carcinogenic VOC contaminant
concentrations would not' likely reach harmful levels in dwellings
over a sustained period of time, some risk numbers were right at
the 10-4 borderline of EPA's acceptable risk range. More refined
models of soil gas migration and risk assessment would likely
indicate lower risk than the modeling effort used in the RI.
'Soil gas measurements taken near residences located above the
shallow groundwater contaminant plume will be used with more
refined; soil gas migration models to better predict the potential
concentration of VOCs in confined spaces of dwellings. Such
monitoring-is expected to be limited in 'scope and only necessary
as long as shallow groundwater VOC concentrations pose a
significant mig~ation threat. Such monitoring should provide
ongoing assurances that vapor migration will not pose significant
indoor air health risks.
Vertical Conduits. Alternative 2 requires that a geophysical
survey be performed to locate abandoned wells that were
identified during the RI as potential conduits of concern because
of their proximity to the contaminated shallow groundwater. If
these wel'ls are located, the feasibility of removing them will be
assessed and, if practical, performed. Shallow Zone A and Zone B
monitoring wells no longer essential to operation and maintenance
of the shallow groundwater extraction and treatment system will
be removed and disposed at 'an appropriate landfill. Removal of
these potential conduits will reduce the potential' ~igration of
shallow groundwater contaminants to deeper aquifers and will
reduce the infiltration of surface water into the shallow'
aquifer.' .
Horizontal Conduits. A geophysical survey will be performed to
locate an old sewer line, water line, and septic system. Once
located, these structures will be excavated, removed, and
disposed off-site at an appropriate landfill. The sewer line and
septic system will probably need to be disposed of at a hazardous
waste landfill because of the likely presence of contaminated
residues. '
structures and Debris. The uncontaminated warehouse and,
decontaminated containment debris (e.g., used visqueen plastic
66
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and stockpile frame boards) and other LB&D site debris will be
removed from the LB&D, property and disposed at a Class III
landfill. These actions will facilitate the installation of a
cap over the contaminated soils.
Residues. Drums of contaminated incinerator ash and
decontamination liquids and residues will be removed from the
LB&D site and disposed at a Class I landfill. Eventually, spent
granular activated carbon from the SVE system will be sent to a
carbon regenerating facility. .
S~ockpiled Soil. Any stockpiled soil that. contains PCBs at
concentrations greater than 50 ppm will be removed from the LB&D
site and disposed at a TSCA landfill. All other stockpiled soil
(approximately 1100 tons) will be spread over the existing
pavements and building pads. Clean fill will be used to grade
the LB&D site and cover the contaminated stockpile soil before
the cap is installed.
princi~al Threa~ Soil. A SVE system will be tested before being
installed in areas near former sumps that contain high soil
concentrations of VOCs. The system will likely include a 600
cUbic-feet-per-minute capacity using a 20 horsepower blower unit.
A SOO-pound GAC treatment unit would remove VOCs from the
extracted soil vapors. Installation of the vapor extraction
wells and modifications of well heads for existing groundwater
monitoring veIls will be completed prior to installation. of the
asphaltic-concrete cap. After .completion of the cap paving, a
small building to house the blower and GAC units will be erected
on the cap.
The SVE system will treat 9,700 tons of soil in-situ to eliminate
the threat of VOCs migrating to the shallow groundwater~ This
system is anticipated to operate for 2 to 3 years. The cleanup
standard for VOCs will be 1 ppm total VOCs.
Soil with Beal~h-Risk-Based COCs. A cap consisting of 180,000
square feet of a 3-inch-thick layer of compacted asphalt on a 6-
inch-thick 'layer of compacted aggregate base (Caltrans Class II)
will be installed on the LB&D property only. Existing LB&D site
monitoring wells, retained for operation and maintenance of the
shallow groundwater extraction and treatment system, will be
protected during installation of the cap and left accessible.
Surface drains will be installed as necessary. Long-term
maintenance will be conducted to ensure the integrity of the cap.
Minor Damage (e.g., utility line excavation) to the existing
pavement on the RFI and ~djacent city sidewalk area properties
will require repair of the pavement at least equal to the.
integrity of the cap for the LB&D property. Extensive
disturbance or exposure of the soil at these properties might
require full implementation of a graded and drained cap as
specified for and consistent with the LB&D property.
Alternative 2 will maintain a cap over the LB&D, RFI, and
adjacent city sidewalk area properties and break the direct
exposure pathway. Thus, the future potential cancer risk to an
67
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on-site worker of 1.3 X 10-2 will be reduced to zero and the HI
of 270 will also be reduced to zero. A total of 65,000 tons of
contaminated soil will remain at the LB&D site beneath the cap.
Alternative 2 has a present worth cost ($1,970,000) that is about
double that of Alternative 1 (Table 8.3). Annual Operation and
Maintenance (O&M) costs ($63,000) include the same groundwater
monitoring costs as Alternative 1 and, in addition, include a
relatively minor increase for the annual O&M of the cap and SVE
system. The present worth of O&M is $968,468. The total capital
costs ($1,001,532) are dominated by the cap and SVE system costs.
8.4.3 Alternative 3: Excavation and Off-site Disposal
Alternative 3 involves removing all non-soil materials
contaminated with LB&D COCs and excavating and removing 65,000
tons of contaminated soil. All materials would be disposed at
appropriate landfills. Because contamination above residential
.risk based standards would be left at the LB&D site following
implementation of Alternative 3, five-year reviews would be
performed in accordance with Section 121(C) of CERCLA. In
addition, Alternative 3 would require land use restrictions to
prevent well construction (for water supply purposes) in source
areas that remain contaminated and deed restrictions for those
properties (LB&D, RFI, and the adjacent sidewalk area belonging
to the city of San Jose) that contain contaminated soil exceeding
residential cleanup standards. Restrictions will prohibit
residential development. Restrictions will also preclude
excavation, other than temporary subsurface work beneath the
existing caps at RFI and the adjacent city sidewalk area -
properties, unless the excavation conforms to the requirements of
Alternative 3.
Groundwater. soil Gas. Conduits. structures/Debris. and Residues.
For Alternative 3, all non-soil materials of concern would be
addressed exactly the same as for Alternative 2, except that all
existing building pads, pavements, and drains would also be
removed and disposed off-site. For a detailed description of the
remedy for each of these materials, see the description under
Alternative 2 in Section 8.4.2.
PrinciDal Threat Soil and soil with Health-Risk-Based COCs. The
only significant difference between Alternatives 2 and 3 is how
they each would handle contaminated soil. Instead of leaving
most of the soil in place, Alternative 3 would excavate all
principal threat soil (9,700 tons) down to the water table
(approximately 20 feet bgs) and excavate all other contaminated
soil (55,300 tons) down to a maximum of 10 feet bgs. All
excavated soil would be disposed off-site at appropriate
landfills. Soil left behind at the LB&D site would present a
cancer risk no greater than 6X 10-5 and a HI of 0.98 for a
future on-site worker. This represents a risk reduction of 4600
times for cancer and 270 times for non-cancer risks.
68
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Table 83
COMPARISON OF ESTIMATED COSTS FOR CLEANUP ALTERNATIVES
LORENTZ BARREL & DRUM SITE
San Jose, California
Category
Capital Costs
Annual O&M
GW Monitoring
Cap
O&M Present Worth*1)
GW Monitoring
Cap
TOTAL PRESENT WORTH COST:
Alternative 1
0
55,500
0
853,174
0
$853,174
Alternative 2
1,001,532
55,500
7,500
853,174
115,294
$1,970,000
Alternative 3
13,756,273
55,500
0
853,174
0
$14,609,447
NOTES:
(i)
Present worth cost was calculated based on a period of 30 years and assuming a discount
rate of 5% per annum.
69
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Alternative 3 involves removal of all structures/debris,
conduits, and all building slabs prior to performance of the soil
excavation described above. About 8,900 tons of miscellaneous
. structures would be demolished and disposed at a Class III
landfill. Soils contaminated with PCBs at concentrations greater
than 50 ppm would be transported to and disposed at a TSCA-
approved facility. Principal threat soil and stockpiled soil
would be disposed at a Class I landfill. Any of the soil that
exceeds land disposal restriction standards may require treatment
at the landfill before actual disposal.
As a result of the extensive excavation, this alternative would
be accomplished in phases of excavation and packfilling. 'All
excavation would be backfilled using imported clean fill
material, compacted, and surface graded. Excavation, clean soil
placement, and compaction would be performed by conventional
equipment, including bulldozers, backhoes, and compaction .
equipment. Dust may be generated during excavation and materials
.handlirig activities. Therefore, dust suppression procedures
would be needed. . .
Perimeter air monitoring would be required during remedial
activities to determine if measures were needed to protect the
community from adverse air emissions. An emergency response plan
is necessary to account for the possibility of a contaminated
soil spill-during off-site transport.
Soil excavation activities at the RFI and adjacent city sidewalk'
area properties would not behconducted unless there was extensive
disturbance or exposure to the soil. A short-term disturbance or
exposure of a small area (e.g., water or utility line trench)
would require re-covering with pavement material equal to or
greater than the existing pavement. Costs calculations for this
alternative include the costs of removal of surface and
subsurface features on the RFI property.
Alternative 3 has a present worth cost ($14,609,447) that is
almost. an order of magnitude higher than the present worth costs
of Alternatives 1 and 2 (Table 8.3). The total capital costs
($13,7~6,273) are dominated by the approximate $6.5 million for
off-site disposal costs. Annual O&M costs ($55,000) for
groundwater monitoring are iderttical to those of Alternatives 1
and 2 and have a present worth of $853,174. The costs for
addressing the various other non-soil materials such as the
vertic~l conduits ($45,300) and soil gas monitoring and
evaluation ($60,000) are the same as under Alternative 2.
9.0
COMPARATIVE ANALYSIS OF ALTERNATIVES
9.1
CRITERIA
The alternatives were evaluated to determine which alternative
provides the best balance of tradeoffs with respect to the
following nine evaluation criteria. These criteria, which are
70
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listed below, are derived from requirements contained in the NCP
and CERCLA Sections 121(b) and'121(c).
The first two criteria are known as the "Threshold criteria"
because 'they must be attained by' an alternative selected as the
remedy. They are:
1.
Overall protection of human health and the
environment; and
2.
Compliance with ARARs.
The next five of the nine criteria are known as the "Primary
Balancing Criteria" because they can provide the major areas of
tradeoffs during the remedy section process. They are:
3.
Long-term effectiveness and permanence;
4.
Reduction of toxicity, mobility, or volume through
treatment;
5.
Short-term effectiveness;
6.
Implementability; and
Cost.
7.
The final two of the nine criteria are known as the "Modifying
criteria" because they are addressed during the public comment
period and may influence the preferred remedy as described in the
Proposed Plan. They are:
9.2
8.
State acceptance/support agency acceptance; and
9.
Community acceptance.
ANALYSXS OF ALTERNATXVES
The major objective of this section is to evaluate the relative
performance of the alternatives with respect to the nine criteria
so that the advantages and disadvantages associated with each
cleanup option are clearly understood. Under each criterion, the
alternative that performs best in that category is discussed
first. The other alternatives are discussed in sequence from
most to least advantageous. ..
9.2.1
Overall p;otection of Human Health and the Environment
Only Alternatives 2 and 3 provide adequate protection of human
health and the environment. Both alternatives reduce the
concentration of VOCs in principal threat soils to levels that.
will not further degrade the shallow groundwater. Alternatives 2
and 3 protect humans from exposure to contaminated structures,
conduits, and residues by capping or removing these contaminated
materials from the LB&D site and properly disposing them off-
71
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site. Alternative 3 is slightly more protective than Alternative
2 because potentially contaminated drains, building pads, and.
pavements are removed and disposed off-site, whereas Alternative
2 leaves these structures in place beneath an asphaltic-concrete
cap. However, the off-site landfill used for disposal under
Alternative 3 would, ultimately, also be capped.
In addition to groundwater monitoring, which is also included in
Alternative 1, Alternatives 2 and 3 include monitoring of soil
gas in residential areas located above the shallow groundwater
plume. These monitoring programs would provide advance warning
in the unlikely event that shallow groundwater VOC contaminants
begin significant migration towards eXposure points in drinking
water aquifers or in confined spaces of dwellings. Alternatives
2 and 3 also provide protection to all groundwater aquifers,
including the shallow aquifer currently under remediation, by
removing potential conduits that might otherwise assist in
potential groundwater migration or surface water infiltration.
Both Alternatives 2 and 3 will rely on deed restrictions and
five-year reviews to ensure that contamination beneath.
neighboring property currently owned by RFI and the City of San
Jose, and soil beneath the OU-2 shallow groundwater treatment
facility will eventually be addressed. In the meantime, current
pavement and building structures prevent human exposure to any
contaminated surface soils assuming. that the underlying soil is
not disturbed. In addition, five-year reviews and deed
. restrictions will prevent inappropriate uses (eg., residential
development or storage of chemical-leaching agents) of the
Lorentz, RFI, and City of San Jose sidewalk properties that
comprise the contaminated soil portion of the LB&D site.
The major distinction between the protectiveness of Alternatives
2 and 3 lies in how each alternative reduces risk of human
exposure to contaminated soils. Alternative 3 provides the
highest degree of protectiveness for the LB&D site because all
soil to a depth of 10 feet bgs posing a risk greater than
6 X 10-5 and exceeding a HI of 1.0 will be excavated and disposed
o£f-site. In most cases, the risk will be much lower because
only several COCs at a given location would be present after
cleanup at concentrations as high as their individual cleanup
standards. Since very limited areas of the LB&D site at a depth
greater than ten feet bgs might contain soils contaminated above
the cleanup standards, it is considered extremely unlikely that
such soil will ever become exposed at the surface under
conditions that would pose significant risk to an on-site worker.
In addition, deed restrictions and future land use plans of the
City of San Jose further reduce the likelihood of significant
risk from human exposure to the levels of contamination that will
remain after cleanup by Alternative 3, particularly if the LB&D,
RFI, and City of San Jose sidewalk properties remain covered by
some form of paving or structure. .
While Alternative 2 eliminates risk from soil contaminants by
breaking the exposure pathway with a cap, it is less protective
than Alternative 3 because almost all of the contaminated soil
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will remain on the LB&D property. A potential cap failure or
leakage of chemical-leaching agents (e.g., acids) through the cap
could increase the level of risk from major soil contaminants
(e.g., lead and PCBs) because the contaminant levels exceed
health-based cleanup standards (i.e., cap action levels) over.
most of the LB&D property, especially in the surface soils. Deed
restrictions, five-year reviews, and city of San Jose future land
use plans are expected to ensure cap integrity and, thus, .
adequate protection by Alternative 2. Alternative 3, on the
other hand, would leave behind clean fill over most of the LB&D
and RFI properties to a depth of four feet or more.
However, when considering the environment as a whole, both
Alternatives 2 and 3 will ultimately result in contaminated LB&D
soils remaining beneath caps because the off-site landfill used
under Alternative 3 would eventually be capped. Thus, .
Alternatives 2 and 3 would provide essentially the same level of
protectiveness for human health and the environment.
Alternative 1 is not protective of human health and the
environment because contaminated materials are not treated,
removed, contained, or even controlled. While there is a strong
likelihood that present and future owners of the property would
maintain a reasonably effective covering over surface soils,
there is no assurance that one or more of the owners would not
inadverten~ly or purposefully contribute to the migration or
unsafe exposure of contaminants on- or off-site. contaminated
stockpile soil, drummed ash, and drain residues would most likely.
be disturbed once private activities resume at the LB&D property.
Alternative 1 does provide a small amount of protectiveness for
the integrity of nearby drinking water wells. Groundwater
monitoring of deeper aquifers will provide advance warning in the
unlikely event that contaminated shallow groundwater began
significant migration down into deeper aquifers. However,
Alternative 1 does not reduce the likelihood of such vertical
migration. Only Alternatives 2 and 3 remove potential vertical
conduits, in addition to groundwater monitoring. Also
Alternatives 2 and 3 provide monitoring and evaluation of the
vadose zone soil. gas as advance warning in the unlikely event
shallow groundwater contaminants migrate into the confined spaces
of dwellings.
In summary, Alternative 3 provides the highest degree of
protectiveness and is closely followed by Alternative 2.
Alternative 1 does not provide adequate protection of human
health and the environment.
9.2.2
compliance with ARARs
The evaluation of the ability of the alternatives. to attainARARs
included a review and analysis of ARARs that was presented in the
FS report for Alternatives 1, 2, and 3 and in Section 7.0 of this
ROD for Alternative 2. Only Alternatives 2 and 3 can be
performed to attain their respective ARARs. Alternative 1, the
no-action alternative, would not attain its ARARs.
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9.2.3
Long-term Effectiveness and Permanence
Alternative 3 provides the highest degree of long-term
effectiveness and permanence because the vast majority of
significantly contaminated soil and all other contaminated
materials will be removed from the LB&D site. Ultimately, these
soils and other contaminated materials may be treated and will be
placed in a landfill that will have a liner and cap with
integrity equal to or greater than the cap planned for
Alternative 2. Alternative 3 will also require land use
restrictions and five-year reviews to insure its long-term
effectiveness since non-principal threat soil will remain beneath
the RFI property, LSGTF treatment facility and adjacent City
sidewal~ area, and contaminated soil at the LB&D site would still
exceed residential cleanup standards.
Alternative 2 provides a lower degree of long-term effectiveness
and permanence because most of the contaminated soil will remain
on-site covered by a cap. The integrity of the cap will rely on
long-term O&M, deed restrictions, and five-year reviews. . Such
long-term controls are critical for Alternative 2 since failure
to prevent or detect a problem with the cap may result in direct
contact with the contaminated soil and further degradation of the
groundwater if leaching agents are introduced.
Both Alternatives 2 and 3 will rely on deed restrictions and
five-year reviews to ensure that contamination beneath
. neighboring property currently owned by RFI and the City of San
Jose, and soil beneath the OU-2 shallow groundwater treatment
facility will eventually be addressed. Delaying remedy
implementation for these properties avoids costly disruptions to
the current operations of RFI, PSS, and the OU-2groundwater
extraction and treatment system. In the meantime, current
pavement and building structures prevent human exposure to any
contaminated surface soils. Five-year reviews and deed
restrictions are slightly less critical for Alternative 3 because
soil contamination remaining on the LB&D, RFI, and adjacent City
sidewalk area properties will be present at concentrations
significantly lower than those remaining with Alternative 2.
In comparing the overall long-term effectiveness for addressing
soil contamination, Alternative 2 is essentially as effective as
Alternative 3. Although, for the LB&D site itself, Alternative 3
(is significantly more effective and permanent because the
contaminated soil would be removed from the site, both
alternatives will result in LB&D soil cQntaminants remaining
beneath a cap either at the LB&D site (Alternative 2) or at a
distant off-site location (Alternative 3). Long-term operation
and maintenance of the Alternative 2 cap along with deed
restrictions and five-year reviews will be implemented to achieve
a level of long-term effectiveness similar to the effectiveness
of the off-site landfills used for Alternative 3. .
Both Alternative 2 and 3 caps will prevent direct exposure to
LB&D soil contaminants and will prevent contamination of
groundwater. However, the off-site landfill (Alternative 3)
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would require a multi-layered cap, liners, and a leachate
collection system because acids and other leaching agents would
also be present or be produced in. the landfill. The single layer
Alternative 2 cap would be easier to maintain because it is
simpler and does not need a leachate collection system. Even
though rainwater infiltration might be better prevented by the
off-site landfill cap, PCBs and metals will not be mobilized
beneath the Alternative 2 cap because acids and other leaching
agents will not be present or produced, and Alternative 2 will
effectively. prevent infiltration of leaching agents at the LB&D
site. Only a rise in perched groundwater or infiltration of
rainwater would ever bring water into contact with the soil
contaminants at the LB&D site, and water is not an effective
leaching agent for these remaining' soil contaminants. Thus
Alternatives 2 will provide a level of long-term protection of
groundwater similar to the level for the more complex cap and
operation and maintenance of an off-site landfill under
Alternative 3. .
Alternatives 2 and 3 are equally' effective over the long-term at
eliminating risk from human exposure-to contaminated conduits,
structures, and residues because these materials will ultimately
remain beneath a cap at the LB&D site (pavements under
Alternative 2) or at an off-site landfill (most of these
materials under both alternatives).
Neither alternative provides a truly permanent r~medy because,
even under Alternative 3, contaminated materials will remain
beneath a cap. However, Alternative 3 does permanently remove
contaminated materials from the LB&D site.
As long as significant contamination remains in the shallow
aquifer, Alternatives 2 and 3 will continue to provide a
sufficient level of groundwater and soil-gas monitoring. Such
monitoring can detect significant VOC migration from shallow
groundwater into deeper aquifers or into soil gas beneath
confined spaces of surface dwellings.
Alternative 1 provides almost no long term effectiveness because
contaminated soil, residues, and structures are not treated,
removed, or adequately contained or controlled. It is possible
that some contaminants will degrade over a long period of time,
but such natural attenuation cannot be relied on.
In summary, Alternative 3 provides more long-term effectiveness
and permanence than Alternative 2, while Alternative 1 provides
almost none. While excavation or removal and off-site disposal
of the contaminated materials under Alternative 3 provide greater
long-term effectiveness for the LB&D site itself, Alternatives 2
and 3 each involve leaving contaminated soil beneath caps that
would provide essentially the same level of long-term
effectiveness for the environment as a whole.
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9.2.4
Reduction of Toxicity, MObility, or Volume Through
Treatment
None of the Alternatives offer significant reductions of
toxicity, mobility, or volume through treatment. This is largely
a result of the heterogeneity of the LB&D site and the lack of
effective technologies that can treat the range of contaminants.
found at the LB&D site.
Alternative 2 will treat about 15% of the contaminated soil at
the LB&D site using in situ SVE to remove VOCs from principal
threat soils. While there will be volume reduction for soils
containing VOC concentrations that threaten groundwater, most of
the original volume will remain contaminated with. COCs that are
non-volatile. SVE will reduce the toxicity of this principal
threat soil by removing most VOCs, although the toxicity of the
remaining COCs is not affected. Mobility of extracted VOCs is
reduced by adsorption onto GAC as part of air emissions control.
Ultimately, the toxicity and mobility of removed VOCs will be
eliminated when the VOCs are incinerated during GAC regeneration.
Only Alternative 2 treats the principal threat soil, thus
satisfying the statutory preference for treatment as a principal
element of the remedy. A cap will be used to break the exposure
pathway to_the vast majority of soil contaminants. Except for
VOCs in a limited volume of LB&D soil, the cap and deed .
restrictions will ensure that all remaini~g soil contaminants
will be essentially immobile in the soil matrix. While capping
is not a treatment, it will slightly increase the immobility of
COCs by limiting the possibility for leachates to reach the COCs.
In addition, capping reduces mobility caused by contaminated
surface soil becoming airborne or ~obile by rainwater runoff.
Alternative 2 does not reduce the toxicity or volume of soil
contaminated with these COCs.
. Alternatives 2 and 3 may reduce the mobility of contaminated
shallow groundwater by the destruction of potential conduits,
although the destruction process is not a true form of treatment.
containment of the shallow groundwater plume is also being
addressed by the ongoing operation of the LSGTF groundwater
extraction system required by the 1988 ROD forOU-2.
Alternative 3 provides no reduction of toxicity, mobility, or .
volume through on-site treatment. Excavated soil may be treated
off-site to address land disposal restrictions at a disposal
facility. If treatment is required prior to land disposal, it
would most likely represent a small reduction in toxicity,
mobility, or volume through treatment because only a small volume
of contaminated soil is expected to exceed LDR standards.
Although excavation and off-site disposal alone do not represent
treatment, Alternative 3 effectively eliminates on-site toxicity,
.mobility, and volume of soil contaminants. However, most of the
toxicity, mobility and volume of LB~D site soil contaminants are
simply transferred to another locat~on, where exposure to
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landfill
unlikely
landfill
event of
leachates may actually increase their mobility in the
event of a landfill cap failure. Exposure to typical
leaching agents is much less probable in the unlikely
on-site cap failure with Alternative 2.
Alternative 1 provides no treatment and no reduction of toxicity,
mobility, or volume. Under this alternative, contamination is
not treated or even removed. It is possible that, over a long
period of time, some contaminants would be destroyed through
natural attenuation, although this is not assured.
In summary, Alternative 2 provides a relatively low level of
reduction of toxicity, mobility, and volume through treatment.
Alternative 3 also provides a low level of reduction of toxicity,
mobility and volume through treatment because treatment is, at
best, a small element of the alternative. Alternative 1 provides
no reduction through treatment.
9.2.5
Short-Term Effectiveness
Alternative 1 provides a high degree of short-term effectiveness
because the only activity conducted at the LB&D site would be
periodic groundwater monitoring of already-installed monitoring
wells. None of the wells are currently contaminated, and they
are anticipated to remain uncontaminated. Because no
construction, soil handling, or excavations are involved,
Alternative-l does not pose any significant short-term risks to
. the on~site workers, members of the community, or the. .
environment. However, it is likely that someone (e.g, an owner)
would want to move the stockpiles of contaminated soil and
drummed ash during resumption of private activities at the
Lorentz property. Inexperienced or irresponsible disturbance of
these two material types could lead to a short-term exposure to
low levels of contamination. However, the City of San Jose and
local health agencies are aware of this contamination and would
be likely to insist that safe handling techniques be used.
Alternative 2 provides a moderate degree of short-term
effectiveness. While the most heavily contaminated soil will
remain undisturbed beneath existing surface pavements, some of
the cap construction activities (e.g., site grading) will involve
disturbing the moderately contaminated stockpiled soils. Also,
excavation of the septic system and conduits will disturb
contaminated soil$. Standard dust suppression practices will
limit exposure to on-site workers and members of the community.
All removal, cap construction, and SVE system construction would
likely be completed within a 6-month period.
operation of the SVE portion of Alternative 2 on the LB&D
property is anticipated to require about 2 years before VOC
concentrations in principal threat soil are reduced to safe
levels. During this time, escape of extracted VOCs to the
atmosphere and subsequent exposure of on-site workers and members
of the community will be virtually eliminated by using a GAC off-
gas emissions control. Neither SVE nor relocation of
contaminated-soil stockpiles will be involved in future
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implementation of Alternative 2 at the RFI property, adjacent
city sidewalk property or at the site of the shallow groundwater
treatment facility.
Alternatives 2 and 3 involve identical! short-term risks during
the removal and disposal of conduits, septic tank, residues, and
the uncontaminated warehouse. Exposure risks for this removal
are minor, considering the relatively small volume of these
contaminated materials compared with the massive volumes of
pavements and contaminated soil to be excavated under Alternative
3. .
Alternative 3 provides the lowest level of short-term
effectiveness because of .the large volume of soil (over 60,000
cubic yards) that will be excavated and then transported through
the immediate community. Dust suppression will be more difficult
than in Alternative 2, not to mention that excavation will also
involve the most heavily contaminated soils. VOC emissions from
.excavation of the principal threat soil will be difficult to
control and will pose the greatest risk to on-site workers.
Depending on actual air concentrations measured during
excavation, workers may need face masks for protection. Because
of the brief exposure time and the probable dilution as VOCs
disperse into the community, members of the community would not
be significantly affected. . .
Excavation-and removal of the contaminated materials from the
LB&D property by Alternative 3.is anticipated to require 10 to 12
months. Additional excavation and removal would be required for
the neighboring properties if disruption or removal of the
existing pavement occurs by the property owners or operators.
Therefore, Alternative 3 would also produce future short-term
risks, although from relatively lo~ levels of contamination.
Before implementation of the additional excavation, existing
pavements and structures will protect on-site workers and members
of the community from soil contamination at_the RFI property and
beneath the shallow groundwater treatment facility and sidewalks
adjacent to the LB&D property.
In summary, relative performance in short-term effectiveness is
most affected by the volume of soil handling involved in each
alternative. Alternative 1 provides the highest degree of short-
term effectiveness because no soils handling, construction, or
removals are involved. Alternative 2 requires relatively little
soil handling compared to the massive amounts required by
Alternative 3. Therefore, Alternative 2 has a significantly
higher degree of short-term effectiveness than Alternative 3.
9.2.6
Implementability
Alternative 1 would be the most easily implemented remedy because
no cleanup actions are required. The five-year reviews and
routine groundwater monitoring of deeper aquifers are relatively
easy to implement, administratively as well as technically.
These are standard practices at numerous other sites and are also
required and easily implemented in Alternatives 2 and 3.
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Alternative 2 would be relatively simple to implement. While
construction of a cap would have significant materials handling
requirements, the materials and expertise are available locally.
Expansion of the cap to th~ RFI property and adjacent City
sidewalk areas would be relatively easy once their structures
were removed. Periodic maintenance of, the cap will control its
future reliability.
The SVE technology required by Alternative 2 is fairly reliable
because of its mechanical simplicity. Also, limited downtime and
very little operator involvement are anticipated. However, as
with any in situ treatment system, samples throughout the
principal threat soil area must be taken frequently to determine
the progress and effectiveness of the technology. since SVE with
GAC emissions control is already being employed at other nearby
cleanup sites, expertise and materials availability as well as
meeting air emissions requirements are not expected to be
problems.
Both Alternatives 2 and 3 involve locating and removing conduits.
The only conduits that pose major problems are poorly-identified,
former agricultural wells and the original SJSU stadium well.
,Some wells may be inaccessible under residential structures and
may present the administrative difficulty of gaining access
permission from property owners. Even if the wells can be
located, their condition and lack of well construction details
may make removal especially difficult. All other conduits are
fairly well described, located, and accessible.
Alternatives 2 and 3 also involve some limited soil gas
measurements and the removal and disposal of various residues and
structures. All these activities are expected to be easily
implementable. .
Alternative 3 will be most difficult to implement, primarily
because of the large volume of contaminated soil that needs to be
. removed. Although standard excavation equipment will be
employed, a significant level of field coordination will be
required to determine that cleanup standards are met and safety
precautions are followed effectively. Soil and air sampling as
well as segregation of clean and dirty soils must be carefully
integrated with progressive excavation and loading of various
soil transporters. Execution of safety procedures and dust
control are much more critical for Alternative 3 not only because
of the large volume of contaminated soil being excavated, but'
also because of the high concentrations of contaminants in some
of the soils.
Another difficulty in the implementation of Alternative 3 is the
delay in excavating soil beneath the neighboring RFI property,
the adjacent City sidewalk area, and beneath the shallow
groundwater treatment facility. A high degree of ongoing
coordination between various agencies and responsible parties
will be necessary to ensure that excavation of contaminated soils
will be carried out effectively and safely, once there was
extensive disturbance of or exposure to the contaminated soil.
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Meanwhile, deed restrictions and five-year reviews would inhibit
any disruption of the current pavement that protects workers and
the community from direct exposure.. .
In summary, Alternative 1 would be the easiest to implement
because no cleanup actions are required. Alternative 2 would be
moderately easy to implement because of the simplicity of the cap
and SVE technologies and the limited disturbance of contaminated
soils. Alternative 3 would be the most difficult to implement
because of the degree of field sampling and coordination required
to safely and effectively meet cleanup objectives. In addition,
Alternative 3 would require a greater level of coordination with
other agencies and parties to ensure future implementation on the
neighboring properties.
9.2.7
cost
Alternative 1 has the lowest present worth cost ($853,175)
because it has no capital costs and only involves annual O&M
costs ($55,500) for groundwater monitoring.
Alternative 2 has a present worth cost ($1,970,000) more than
double that of Alternative 1. Annual O&M costs ($63,00Q) include
the same groundwater monitoring costs as Alternative 1 and, in
addition, include a relatively minor increase for the annual O&M
of the cap. The present worth of O&M is $968,468. The total
capital cost ($1,001,532) is dominated by the cap, conduits and
SVE system costs. .
Alternatives 2 and 3 have the same costs for soil gas and
groundwater monitoring and for the removal and disposal of the
septic tank, warehouse, conduits, and residues.' These non-soil
capital costs (about $300,000) are relatively minor in comparison
to the capital costs necessary for addressing soil contaminants.
Alternative 3"has a present worth cost ($14,609,447) that is an
order of magnitude higher than the present worth costs of
Alternatives 1 and 2. The total capital costs ($13,756,273) are
dominated by the approximate $6.5 million off-site disposal
costs. Annual O&M costs ($55,500) for groundwate~ monitoring are
identical to those of Alternative 1 and have a present worth of
$0.9 million. .
When costs in common to Alternatives 2 and 3 (groundwater
monitoring, soil gas monitoring, and removal and disposal of the
septic tank, warehouse, conduits, and residues) are subtracted
out from their respective present worth costs, the main'
distinction between these two alternatives becomes apparent. To
attain ARARs and provide adequate protection from soil
contaminants, Alternative 2 wil,l cost about $0.9 million compared
with $14 million for Alternative 3. While Alternative 3 is more
protective over the long term, it is probably not even an order
of magnitude more protective than Alternative 2, and thus, a 15
times greater cost for Alternative 3 is not justified.
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In conclusion, Alternative 2 is more cost effective than
Alternative 3 because the cap will provide adequate protection of
human health and the environment for a cost almost fifteen times
less than the soil excavation and off-site disposal of
Alternative 3. Despite the lowest overall cost, Alternative 1 is
the least cost effective because it is the only alternative that.
does not provide adequate protection or attain ARARs.
9.2.8
state/support Agency Acceptance
The FS and Proposed Plan Fact Sheet were reviewed by the State of
California's DTSC. In a letter dated June 23, 1993, DTSC
concurred with EPA's proposed cleanup plan.
In addition, RWQCB, SCVWD, and DHS's Environmental Epidemiology
and Toxicology Branch (EETB) reviewed the Proposed Plan Fact
Sheet and attended the May 27, 1993' public meeting in San Jose.
Each of these support agencies concurred with EPA's proposed
cleanup plan.
The main concerns raised by State and support agencies focused on
interim controls at the LB&D property and on groundwater and soil
gas monitoring methods. However, EPA believes these minor
technical concerns will be addressed by the selected remedy. A
full response to comments received from state and support
agencies can be found in the Responsiveness Summary (Part III) in
this ROD.
9.2.9
community Acceptance
The Proposed Plan was presented to the community of San Jose in a
fact sheet and at a public meeting. During the 30 day comment
period, 5 comment letters were received and one formal comment
was made at the public meeting.
Commentors from the local community prefer Alternative 3. The
major concerns of the community were long-term effectiveness,
future land use, and cost. Commentors from the local community
generally believe that Alternative 3 is the only alternative that
wil~ provide sufficient long-term effectiveness, especially
because they would like to see the former LB&D facility
properties restored to their fullest potential uses. Commentors
from the local community are concerned that Alternative 2 would
not allow profitable development of the former LB&D facility
properties, which in turn might affect the prosperity of their
neighborhood community and property values. Commentors from the
local community generally believe that the increased cost of
Alternative 3 is not that much on an absolute basis and that the
PRPs should pay for Alternative 3.
None of the comments .received provided EPA with the technical
justification for selecting Alternative 3 or making any changes
to Alternative 2. EPA remains convinced that Alternative 2 is
essentially just as protective of human health and the
environment as Alternative 3 over the long term. EPA knows of no
indications that local prosperity or property values will be
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negatively affected by Alternative 2, and points out that
successful businesses are currently operating on part of the LB&D
site under the same limitations that will exist under Alternative
2. In addition, the City of San Jose and SJSU have joint plans
to expand the recreational development of adjacent properties and
have strong desires for the LB&D property to be used for public
parking~
EPA disagrees that the absolute cost of Alternative 3 is
relatively low and, therefore, should be spent by PRPs. EPA
believes that the absolute cost is significant, especially when
compared to the overall site cleanup costs. As required by law,
EPA evaluated cost and effectiveness of the remedies as elements
of the nine criteria used to evaluate the alternatives. EPA
. believes that spending $12.6 million more for a remedy
(Alternative 3) that would only provide marginally better
protection of a relatively low level threat (direct contact with
PCBs and lead present at average concentrations near or below the
cleanup standards typically used for industrial sites without a
cap) is not justified.
All community concerns and comments received during the public
. comment period are addressed in the Responsiveness Summary (Part
III) in this ROD. .
10.0
THE SELECTED REMEDY
10.1
BASIS OF SELECTION
Only two of the alternatives, Alternatives 2 and 3, meet the
threshold criteria by complying with their respective ARARs (See
section 7) and providing adequate protection of human health and
the environment. Both alternatives provide a good level of
overall protection, although they provide relatively low levels
of reduction of toxicity, mobility, or volume through treatment.
While Alternative 3 provides a greater level of long-term
. effectiveness and permanence because all significant soil
contamination is removed from the LB&D and RFI property,
Alternative 2 will provide a similar level of long-term
effectiveness with long-term maintenance, deed restrictions, and
five-year reviews ensuring cap integrity.
Alternative 2 provides greater short-term effectiveness and is
easier to implement than Alternative 3, but the main advantage of
Alternative 2 is its cost effectiveness. The Alternative 2 cap
will provide good protection of human health and the environment
at a significantly lesser cost (15 times less) than the soil'
excavation and off-site disposal in Alternative 3. For these
reasons, EPA has selected Alternative 2, the hybrid closure cap
with in situ SVE, as the final remedy for the LB&D site.
10.2
FEATURES OF THE REMEDY
All features of Alternative 2, the Selected Remedy, including
remediation goals, cleanup standards, and compliance boundaries,
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are as described in detail in Section 8. Costs are summarized in
Table 10.1. The selected remedy, which addresses soil,
structures, debris, residues, vertical and horizontal conduits,
groundwater, and vadose zone soil gas in residential areas,
contains the following features:
princi~al Threat Soil. Principal threat soil will be treated by
SVE to remove VOCs present at concentrations that total more than
1 ppm. EPA assumes, based on engineering experience, that the
COCs listed in Table 5.1 do not pose a threat to groundwater at
the concentrations found during the RI.
Extraction of VOC-contaminated soil vapors followed by capture of
the VOCs on granular activated carbon will protect the shallow
groundwater from further degradation by these highly mobile
contaminants. Health risks from the VOCs would be eliminated
upon destruction of the VOCs during the regeneration of the
granular activated carbon by incineration. The SVE system is
estimated to cost $78,000 to construct and $84,000 to operate for.
2 years.
Soil with Bealth-Risk-Based COCs. A cap (single layer asphaltic-
concrete pavement without leachate collection or monitoring
systems) will be used to contain soil contaminated with non-
mobile chemicals (e.g., PCBs, pesticides, and metals) that pose
health risks. Long-term cap maintenance will ensure elimination
of the expO$ure pathway to the contaminated soils and to the
contaminated building pads that will be left in place beneath the
cap. capital costs for the cap are estimated to be $344,940 and
the present worth of 30 years of cap maintenance is estimated to
be $115,294. The present worth cost of performing cap
maintenance in perpetuity is estimated to be $150,000.
Summary of Estimated Costs for the Selected Remedy
The cap will protect humans from direct contact with building
pads and contaminated soil present at or adjacent to the former
LB&D facility. In addition to the LB&D and RFI properties, the
cap will cover all adjacent soil (e.g., adjacent city sidewalk
area) that exceeds the cap action levels for soil. Risk will be
reduced to zero because the cap breaks the exposure pathway. The
cap will also minimize contaminant leaching by surface water
infiltration.
Any stockpiled soil that contains PCBs at concentrations greater
than 50 ppm will be removed from the LB&D site and disposed at a
TSCA landfill. All other stockpiled soil (approximately 1100
tons) will be spread over the existing pavements and building
pads; Clean fill will be used to grade the LB&D property and
cover the contaminated stockpiled soil before the cap is
installed. It is estimated that 50 9ubic yards of stockpiled
soil will need to be removed and disposed at a cost of
approximately $10,280.
Deed restrictions will be imposed for those properties (LB&D,
RFI, and the adjacent sidewalk area belonging to the City of San
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Table 10.1
SUMMARY OF ESTJl\ttA TED COSTS FOR mE SELECTED REMEDY
HYBRID CLOSURE
LORENTZ BARREL & DRUM SITE
San Jose, California
DESCRIPI'ION
TOTAL COST
($)
CAPITAL COST
Site Preparation
Removal & Disposal of Structures & Surface Features
Residue Disposal
Off-site Disposal of Stockpiled Soil PCBs> 50 ppm
Conduit Investigation & Abandonment
Cap Construction
In Situ Treatment of Principal Threat Soil, SVE System
SVE System Operations for 2 Years (monitoring, electricity, and maintenance)
57,400
65,560
3,900
10,280
45,300
344,940
78,000
84,000
Construction Cost Subtotal
689,380
Health & Safety
Engineering - & Construction Management
Administration
Contingency
Deed Restriction
Soil Gas Monitoring and Evaluation
30,269
60,538
30,269
121,076
10,000
60,000
TOTAL CAPITAL COST
$1,001,532
ANNUAL O&M COST
Groundwater Monitoring (Zones C and D)
Site Cap Maintenance
55,500
7,500
Annual O&M Cost Subtotal
63,000
TOTAL PRESENT WORTH OF ANNUAL O&M COST(l)
$968,468
TOTAL PRESENT WORm COST
$1,970,000
NOTES:
(1)
GW Monitoring and Cap Maintenance. Assumes 5 % annual interest rate for 30 years.
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Jose) that contain contaminated soil exceeding cap-action levels.
Restrictions will prohibit residential development and will limit
industrial development to activities that do not breach the.
integrity of the cap and do not mobilize the soil contaminants.
Restrictions will also preclude excavation, other than temporary
subsurface work beneath the cap, and will require complete
restoration of any disturbed fill or cap once any such temporary
work is completed.
In accordance with Section 121(c) of CERCLA, reviews of the
protectiveness of the selected remedy, in particular the cap and
its continued maintenance, will occur at least once every five
years. The reviews will also consider the ongoing effectiveness
of deed restrictions and other land use restrictions.
structures and Debris. The warehouse and contaminated septic
tank and miscellaneous debris (e.g., visqueen cover used on
stockpiled soils) will be removed and disposed off-site. These
actions will eliminate the potential for direct exposure to
contaminated structures and debris located at the LB&D property
and will also facilitate installation of the cap. The cost of
addressing the structures and debris is estimated at $65,560. .
Residues. Incinerator ash and decontamination liquids will be
removed and disposed at an off-site landfill. Spent granular'
activated carbon will be decontaminated at a regeneration
facility. -The regeneration of the spent carbon will involve
incineration, resulting in the destruction of the sorbed. organic
. contaminants. Residues contained in the contaminated septic
system and sewer line will be addressed by the removal of these
potential conduits. These actions will prevent human exposure to
contaminated residues located at the LB&D property. The cost of
r~sidue disposal is estimated to be $3,900.
conduits. Accessible wells that could act as potential conduits
in the vicinity of the shallow groundwater contamination plume
will be located, assessed, and removed and disposed of at an off-
site facility. However, there will always be some uncertainty
whether all potential conduits have been located. It is possible
that some of the old wells will not be able to be located or
might not be accessible.
In the particular case of the currently-operating SJSU Spartan
Stadium well, the pumping of this potential conduit may have a
direct effect on the direction of flow in the intermediate
aquifer and may increase the chances that contaminated shallow
groundwater could migrate down to the intermediate aquifer. In
the event that the intermediate aquifer becomes contaminated by
shallow aquifer contaminants, EPA will reevaluate the need for
restricting the use of this drinking water well to agricultural
use or may require its removal.
The removal .of potential conduits will reduce the potential for
shallow groundwater contaminants to migrate to deeper aquifers.
Removal of non-essential monitoring wells will also reduce the
likelihood that the wells could act as potential conduits of
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surface water into the shallow aquifer zone. In addition,
removal and disposal of the contaminated septic system and sewer
line, following their excavation, will reduce potential exposure
to or migration of contaminated residues contained in these
potential horizontal conduits. The removal of potential
conduits, including a geophysical survey, is estimated to cost
$45,300.
Groundwater. Additional protection from future potential
domestic exposure of humans to' contaminated groundwater will be
provided by a mechanism for early warning in the unlikely event
that shallow groundwater contaminants begin significant migration
towards the deep aquifer that is used for drinking water. Both
the intermediate and deep aquifers will be monitored for VOCs on
a semi-annual basis to alert the community if VOCs are ever
detected. Also, land use restrictions will prevent well
construction (for water supply purposes) in source areas that
remain contaminated. The estimated present worth cost of 30
years of groundwater monitoring is.$853,174.
Vadose Zone Soil Gas. Monitoring of the s011 gas near residences
situated above the shallow groundwater plume will provide advance
warning in the unlikely event that shallow groundwater VOCs begin
a significant migration towards the confined spaces of dwellings.
Soil gas monitoring is estimated to cost $60,000.
11.1
11.0
STATUTORY DETERMINATIONS
PROTECTIVENESS
The selected remedy is protective of
environment. Protection is achieved
in the aquifers extending beyond the
fo110w~ng ways:
(1)
(2)
human health and the
at this industrial site, and
former LB&D facility, in the
The cap will protect humans from direct contact with
building pads and contaminated soil present at or
. adjacent to the former LB&D facility. In addition to the
LB&D and RFI properties, the cap will cover all adjacent
soil (e.g., adjacent city sidewalk area) that exceeds the
cap action levels for soil. Risk will be reduced to zero
because the cap breaks the exposure pathway. Soil beyond
the LB&D site boundaries is not subject to the cap
because it meets cap action levels. Such soil, if
exposed under an industrial on-site worker scenario,
would exhibit a maximum cancer risk of.6 X 10-5 and a HI
less than 1. The cap will also minimize contaminant'
leaching by surface water infiltration.
Extraction of VOC-contaminated soil vapors followed by
capture of the VOCs on granular activated carbon will.
protect the shallow groundwater from further degradation
by these highly mobile contaminants. Health risks from
the VOCs would be eliminated because they will be
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(3)
(4)
(5)
(6)
11.2
destroyed during regeneration of the granular activated
carbon.
Removal and off-site disposal of non-essential wells
located in the vicinity of the shallow groundwater
contamination plume will reduce the potential for the
wells to act as vertical migration conduits for shallow
groundwater contaminants. In addition, excavation and
off-site disposal of the contaminated septic system and
sewer line will reduce potential exposure to or migration
of contaminated residues.
Removal and offsite disposal of contaminated incinerator
ash from the LB&D facility operations, stockpiled soil
containing greater than 50 ppm PCBs, and contaminated
debris and residues will prevent future direct human
contact with these contaminated materials.
Additional protection from future potential human
exposure to contaminated groundwater will be provideq by
a mechanism for early warning in the unlikely event that
shallow groundwater contaminants migrate towards the
deep, drinking water aquifer. Both the intermediate and
deep aquifers will be monitored for VOCs on a semi-annual
basis to alert the community if VOCs are detected. In a
similar fashion, monitoring of the soil gas near
residences situated above the shallow groundwater plume
will provide advance warning in the unlikely event that
VOCs begin a significant migration towards the confined
spaces of dwellings.
Land use restrictions will prevent well construction (for
water supply purposes) in source areas that remain
contaminated. Deed restrictions will be imposed for the
properties (LB&D, RFI, and the adjacent sidewalk area
belonging to the City of San Jose) that contain
contaminated soil exceeding cap action levels. Deed
restrictions will prohibit residential development and
will limit industrial development to activities that do
not breach the integrity of the cap or do. not mobilize
the soil contaminants. Restrictions will also preclude
excavation, other than temporary subsurface work beneath
the cap and will require complete restoration of any
disturbed fill or cap once any such temporary work is
completed.
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
The selected remedy complies
that are legally applicable,
to the remedial action. See
of ARARs.
with federal and state requirements
or relevant and appropriate (ARARs)
Section 7 for a detailed discussion
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11.3
PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
The selected remedy will use SVE to treat approximately 15
percent of the contaminated soil at the LB&D site. This in situ
treatment will occur only on the LB&D property. Mobility of the
extracted VOCs is reduced by adsorption onto granular activated
carbon as part of air emissions control. Ultimately, the.
toxicity and mObility of removed voCswill be eliminated when the
VOCs are incinerated and destroyed during GAC regeneration. No
other treatment processes are involved in the final remedy,
mostly because of the lack of technologies that can effectively
treat the heterogeneous mix of LB&D soil COCs. Because principal
threat soil is treated, the selected remedy satisfies the
statutory preference for treatment as a principal element of the
remedy. .
While there will be volume reduction for soil containing VOC
concentrations that threaten groundwater as principal threat,
most of the original volume will remain contaminated with non-
volatile COCs (e.g., PCBs and metals). SVE will reduce the
toxicity of this principal .threat soil by removing most of the
VOCs, although the toxicity of the remaining COCs is not
affected.
11.4
USE OF PERMANENT SOLUTIONS, ALTERNATIVE TREATMENT OR
RESOURCE RECOVERY TECHNOLOGIES
Permanent solutions, alternative treatment and alternative
resource technologies were evaluated during the FS, but were not
determined to be practicable or cost effective for most of the
contaminated soil at the LB&D site, largely because of the
heterogeneous mixture of COCs. By its use of SVE for principal
threat soil, the selected remedy utilizes permanent solutions and
alternative treatment technologies to the maximum extent
practicable.
Because this remedy will result in hazardous substances remaining
onsite above health-based levels and the cap will require long-
term routine maintenance, reviews of the protectiveness of the
remedy will be conducted every five years, in accordance with.
section 121(c) of CERCLA.
11.5
COST EFFECTIVENESS
The remedy is cost effective because adequate protection is
achieved for the estimated cost of performance. The analysis
contained in the FS and this ROp demonstrates that additional
remedial action and the cost associated with that action would
not achieve a significantly greater reduction in risk, but would
result in a dramatically higher cost. The FS and this ROD also
show that a lesser effort and a lower cost would result in a
measurably higher risk at the LB&D site.
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11.6
SUHKARY
The selected remedy is protective of human health and the en-
vironment, complies with ARARs, and is cost-effective. This
remedy utilizes permanent solutions and alternative treatment
technologies to the maximum extent practicable, and satisfies the
statutory preference for remedies that employ treatment that
reduces toxicity, mobility, or volume as a principal element.
Because the remedy will result in hazardous substances remaining
on-site above health-based levels, a five-year review, pursu~nt
to section 121(c) of CERCLA, 42 U.S.C. S9621(c), will be
conducted at least once every five years after initiation of the
remedial action to ensure that the remedy continues to provide
adequate protection of human health and the environment.
12.0
DOCUMENTATION OF SIGNIFICANT CHANGES
The Proposed Plan for the LB&D site was released for pUblic
comment in May 1993. The Proposed Plan identified Alternative 2,
the hybrid closure cap, as the preferred alternative. EPA
reviewed all written and verbal comments submitted during the
public comment period. Upon review of these comments, EPA
determined that no significant changes to the remedy, as it was
originally- identified in the Proposed Plan, were necessary.
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