SEMS-RM DOCID # 100010493
PROl*-0
Record of Decision
for
FOSET #2 - Group 2 Action Sites
Former McClellan Air Force Base,
McClellan, California
U.S. Environmental Protection Agency
Region 9
San Francisco, California
September 2018
Final
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
TABLE OF CONTENTS
ACRONYMS AND ABBREVIATIONS VI
1.0 PART 1: THE DECLARATION 1
1.1 Site Name and Location 1
1.2 Statement of Basis and Purpose 3
1.3 Assessment of the Sites 4
1.4 Description of Selected Remedies 4
1.4.1 Alternative VOC2 - Institutional Controls to Restrict Land Use 5
1.4.2 Alternative VOC3 - ICs to Restrict Land Use and Engineered Controls
(ECs) to Mitigate Shallow Soil Gas Contamination 6
1.4.3 Alternative Non-VOC2 - ICs to Restrict Land Use, ECs, and Monitoring 6
1.4.4 Alternative Non-VOC4a - Excavation and Disposal and ICs to Restrict
Land Use 7
1.4.5 Summary of the Selected Remedies 8
1.5 Statutory Determinations 15
1.6 Data Certification Checklist 15
1.7 Authorizing Signatures 17
2.0 PART 2: THE DECISION SUMMARY 19
2.1 Site Name, Location, and Description 19
2.2 Site History and Enforcement Activities 19
2.2.1 Site History 19
2.2.2 Previous Investigations 20
2.2.3 Enforcement Activities 20
2.2.4 Base Closure and Privatization 20
2.3 Community Participation 21
2.3.1 Community Interviews and Fact Sheet 21
2.3.2 Community Involvement Plan 21
2.3.3 Public Notifications 21
2.3.4 FOSET #2 Group 2 Action Sites Proposed Plan 21
2.3.5 FOSET #2 Group 2 Action Sites Proposed Plan Outreach 22
2.3.6 FOSET #2 Group 2 Action Sites Proposed Plan Public Meeting 22
2.3.7 EPA Participation in Outreach Events 22
2.3.8 Restoration Advisory Board 22
2.3.9 Information Repositories 22
2.3.10 Administrative Record 23
2.4 Scope and Role of FOSET #2 Group 2 Action Sites Response Actions 23
2.4.1 Past Removals/Interim Actions 25
2.5 Site Characteristics 25
2.5.1 Topography, Geology, and Hydrology 47
2.5.2 Ecological Characteristics 47
2.6 Current and Potential Future Land and Resource Uses 47
2.7 Summary of Site Risks 48
2.7.1 Conceptual Site Model 48
2.7.2 Human Health Risks 48
2.7.2.1 Identification of Contaminants of Concern 48
2.7.2.2 Exposure Assessment 49
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
2.7.2.3 Toxicity Assessment 53
2.7.2.4 Risk Characterization 53
2.7.3 Ecological Risks 65
2.7.4 Basis for Action 65
2.8 Remedial Action Objectives 65
2.8.1 Basis and Rationale for Remedial Action Objectives 65
2.8.2 How the Remedial Action Objectives Address Risks 66
2.8.3 Basis of Cleanup Levels 66
2.9 De scription of Alternative s 74
2.9.1 Common Elements and Distinguishing Features of Each Alternative 76
2.9.1.1 Common Elements 76
2.9.1.2 Distinguishing Features 77
2.10 Summary of Comparative Analysis of Remedy Alternatives 77
2.10.1 VOC Alternatives 79
2.10.2 Non-VOC Alternatives 79
2.11 Principal Threat Wastes 109
2.12 Selected Remedies 109
2.12.1 Alternative VOC2 109
2.12.2 Alternative VOC3 109
2.12.3 Alternative Non-VOC2 110
2.12.4 Alternative Non-VOC4a 110
2.12.5 Institutional Controls Ill
2.12.5.1 Existing ICs 112
2.12.5.2 Selected ICs 113
2.12.6 Engineering Controls 117
2.12.6.1 Vapor Barrier 117
2.12.6.2 Gas Collection 118
2.12.6.3 Ventilation 118
2.12.6.4 Surface Cover 118
2.12.6.5 Sediment Collection 119
2.12.7 Summary of the Estimated Remedy Costs 122
2.12.8 Summary of the Rationale for the Selected Remedies 122
2.12.9 Expected Outcomes 126
2.13 Statutory Determinations 127
2.13.1 Protection of Human Health and the Environment 127
2.13.2 Compliance with Applicable or Relevant and Appropriate Requirements
(ARARs) 128
2.13.3 Use of Permanent Solutions and Alternative Treatment Technologies to
the Maximum Extent Practicable 129
2.13.4 Preference for Treatment as a Principal Element 129
2.13.5 Requirements for Five-Year Reviews 129
2.13.6 Cost Effectiveness 129
2.13.7 State Acceptance 130
2.13.8 Community Acceptance 130
2.14 Documentation of Significant Changes 130
3.0 PART 3: RESPONSIVENESS SUMMARY 131
3.1 Stakeholder Comments and Lead Agency Responses 131
3.2 Technical and Legal Issues 132
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
4.0 REFERENCES 133
5.0 GLOSSARY/ACRONYMS 136
ATTACHMENT A. APPLICABLE OR RELEVANT AND APPROPRIATE
REQUIREMENTS 141
ATTACHMENT B. PAST FOSET #2 GROUP 2 ACTION SITES REMOVAL
ACTIONS 145
ATTACHMENT C. SUMMARY OF SITE RISKS 149
ATTACHMENT D. RATIONALE FOR SELECTED REMEDIES AND SITE
FIGURES 157
List of Figures
Figure 1-1 FOSET #2 Group 2 Action Sites Locations 2
Figure 2-1 Conceptual Model for Vapor Intrusion Pathway 50
Figure 2-2 Exposure Pathway Analysis 51
Figure D-l AOC 325 Site Features Map 158
Figure D-2 AOC 325 IC Compliance Boundary Map 158
Figure D-3 CS P-005 Site Features Map 158
Figure D-4 CS P-005 IC Compliance Boundary Map 158
Figure D-5 CS P-006 Site Features Map 158
Figure D-6 CS P-006 IC Compliance Boundary Map 158
Figure D-7 CS S-021 Site Features Map 158
Figure D-8 CS S-021 IC Compliance Boundary Map 158
Figure D-9 CS S-027 Site Features Map 158
Figure D-10 CS S-027 IC Compliance Boundary Map 158
Figure D-l 1 CS T-037 Site Features Map 158
Figure D-12 CS T-037 IC Compliance Boundary Map 158
Figure D-13 CS T-059 Site Features Map 158
Figure D-14 CS T-059 IC Compliance Boundary Map 158
Figure D-l5 PRL L-001 (F2) Site Features Map 158
Figure D-l6 PRL L-001 (F2) IC Compliance Boundary Map 158
Figure D-l7 PRL L-002 Site Features Map 158
Figure D-l8 PRL L-002 Compliance Boundary Map 158
Figure D-l9 PRL L-003 (F2) Site Features Map 158
Figure D-20 PRL L-003 (F2) IC Compliance Boundary Map 158
Figure D-21 PRL L-004 Site Features and Target Volume Map 158
Figure D-22 PRL L-004 Site Features Map 158
Figure D-23 PRL L-004 IC Compliance Boundary Map 158
Figure D-24 PRL L-005 (F2) Site Features Map 158
Figure D-25 PRL L-005 (F2) IC Compliance Boundary Map 158
Figure D-26 PRL P-001 Site Features Map 158
Figure D-27 PRL P-001 IC Compliance Boundary Map 158
Figure D-28 PRL P-003 Site Features Map 158
Figure D-29 PRL P-003 IC Compliance Boundary Map 158
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Figure D-30 PRL P-004 Site Features Map 158
Figure D-31 PRL P-004 IC Compliance Boundary Map 158
Figure D-32 PRL S-022 & SA 069 Site Features and Target Volume Map 158
Figure D-33 PRL S-022 IC Compliance Boundary Map 158
Figure D-34 SA 069 IC Compliance Boundary Map 158
Figure D-35 PRL S-037 Site Features Map 158
Figure D-36 PRL S-037 IC Compliance Boundary Map 158
Figure D-37 PRL T-015 Site Features Map 158
Figure D-38 PRL T-015 Compliance Boundary Map 158
Figure D-39 PRL T-019 Site Features Map 158
Figure D-40 PRL T-019 IC Compliance Boundary Map 158
Figure D-41 PRL T-031 Site Features Map 158
Figure D-42 PRL T-031 IC Compliance Boundary Map 158
Figure D-43 PRL T-033 Site Features Map 158
Figure D-44 PRL T-033 IC Compliance Boundary Map 158
Figure D-45 SA 037 Site Features Map 158
Figure D-46 SA 037 IC Compliance Boundary Map 158
Figure D-47 SA 038 Site Features Map 158
Figure D-48 SA 038 IC Compliance Boundary Map 158
Figure D-49 SA 040 Site Features Map 158
Figure D-50 SA 043 Site Features Map 158
Figure D-51 SA 043 IC Compliance Boundary Map 158
Figure D-52 SA 044 Site Features Map 158
Figure D-53 SA 044 IC Compliance Boundary Map 158
Figure D-54 SA 047 Site Features Map 158
Figure D-55 SA 047 IC Compliance Boundary Map 158
Figure D-56 SA 048 Site Features Map 158
Figure D-57 SA 048 IC Compliance Boundary Map 158
Figure D-58 SA 053 Site Features Map 158
Figure D-59 SA 053 IC Compliance Boundary Map 158
Figure D-60 SA 058 Site Features Map 158
Figure D-61 SA 058 IC Compliance Boundary Map 158
Figure D-62 SA 059 Site Features Map 158
Figure D-63 SA 059 IC Compliance Boundary Map 158
Figure D-64 SA 067 Site Features Map 158
Figure D-65 SA 067 IC Compliance Boundary Map 158
Figure D-66 SA 068 Site Features Map 158
Figure D-67 SA 068 IC Compliance Boundary Map 158
Figure D-68 SA 071 Site Features Map 158
Figure D-69 SA 071 IC Compliance Boundary Map 158
Figure D-70 SA 073 Site Features Map 158
Figure D-71 SA 073 IC Compliance Boundary Map 158
Figure D-72 SA 077 Site Features Map 158
Figure D-73 SA 077 IC Compliance Boundary Map 158
Figure D-74 SA 078 Site Features Map 158
Figure D-75 SA 078 IC Compliance Boundary Map 158
Figure D-76 SA 079 Site Features Map 158
Figure D-77 SA 079 IC Compliance Boundary Map 158
Figure D-78 SA 081 Site Features and Target Volume Map 158
Figure D-79 SA 081 IC Compliance Boundary Map 158
Figure D-80 SA 086 Site Features Map 158
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Figure D-81 SA 086 IC Compliance Boundary Map 158
Figure D-82 SA 094 Site Features Map 158
Figure D-83 SA 094 IC Compliance Boundary Map 158
Figure D-84 SA 098 Site Features Map 158
Figure D-85 SA 098 IC Compliance Boundary Map 158
Figure D-86 SA 101 Site Features Map 158
Figure D-87 SA 101 IC Compliance Boundary Map 158
Figure D-88 SA 102 Site Features Map 158
Figure D-89 SA 102 IC Compliance Boundary Map 158
List of Tables
Table 1-1 45 FOSET #2 Group 2 Action Sites 1
Table 1-2 Selected Remedies for FOSET #2 Group 2 Action Sites 8
Table 2-1 Site Characteristics 27
Table 2-2 Summary of Cancer Risks and Non-carcinogenic Hazards for the FOSET #2
Group 2 Action Sites in a Restricted Use Scenario 57
Table 2-3 Cleanup Levels - FOSET #2 Group 2 Action Sites 69
Table 2-4 Levels for Protection of Surface Water and Groundwater Quality 71
Table 2-5 Shallow Soil Gas Institutional Control Compliance Levels 73
Table 2-6 Comparative Analysis of Both VOC and Non-VOC Alternatives 81
Table 2-7 Summary of Selected Institutional Controls 114
Table 2-8 Summary of Selected Engineered Controls and Monitoring 119
Table 2-9 Summary of Estimated Selected Remedy Costs 122
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Acronyms and Abbreviations
1-ig/dL
AFB
AFCEC
AFRPA
AoC
AOC
ARAR
AST
bgs
BRAC
CCR
CDI
CDPH
Central Valley Water Board
CERCLA
CERCLIS
CFR
CHHSLs
CIP
COC
CS
CSM
CTR
CU
cy
DCA
DCB
DCE
DLM
DTSC
EC
EPA
EPC
ERA
ESCA
F2
FFA
FOSET
FOSS
FS
FSS
HHRA
HI
HQ
IC (#)
microgram per deciliter
Air Force Base
Air Force Civil Engineer Center (also known as AFCEC/CIBW)
Air Force Real Property Agency
Administrative Order on Consent
area of concern
applicable or relevant and appropriate requirement
aboveground storage tank
below ground surface
Base Realignment and Closure
California Code of Regulations
chronic daily intake
California Department of Public Health
Central Valley Regional Water Quality Control Board
Comprehensive Environmental Response, Compensation, and Liability
Act
Comprehensive Environmental Response, Compensation, and Liability
Information System
Code of Federal Regulations
California Human Health Screening Levels
Community Involvement Plan
contaminant of concern
confirmed site
Conceptual Site Model
California Toxics Rule
consolidation unit
cubic yards
dichloroethane
dichlorobenzene
dichloroethene
Designated Level Methodology
Department of Toxic Substances Control
engineered controls
Environmental Protection Agency
exposure point concentration
ecological risk assessment
Environmental Services Cooperative Agreement
the portion of the IRP site within FOSET #2
Federal Facilities Agreement
Finding of Suitability for Early Transfer
Follow-on Strategic Sites
feasibility study
Focused Strategic Sites
human health risk assessment
hazard index
hazard quotient
investigation cluster (used with a numeral to identify SVE
investigation/cleanup areas)
institutional control
VI
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McClellan FOSET #2-
Group 2 Action Sites ROD Final
ID
identification
IP
initial parcel
IRP
Installation Restoration Program
IWL
industrial waste line
IWTP
industrial wastewater treatment plant
lbs
pounds
MBP
McClellan Business Park, LLC
MCL
maximum contaminant level
mg/kg
milligrams per kilogram
MTBE
methyl tert-butyl ether
NCP
National Oil and Hazardous Substances Pollution Contingency Plan
NFA
no further action
No.
number
NPDES
National Pollutant Discharge Elimination System
NPL
National Priorities List
OMB
Office of Management and Budget
OU
operable unit
OWS
oil and water separator
O&M
operation and maintenance
PAH
polycyclic aromatic hydrocarbon
PCA
tetrachloroethane
PCB
polychlorinated biphenyl
PCE
tetrachloroethene
PCG
preliminary cleanup goal
ppbv
parts per billion by volume
PRL
potential release location
RAB
Restoration Advisory Board
RAO
remedial action objective
RAWP
remedial action work plan
RCRA
Resource Conservation and Recovery Act
RD/RA
remedial design/remedial action
RfD
reference dose
RI
remedial investigation
RICS
remedial investigation characterization summary
RI/FS
remedial investigation/feasibility study
ROD
record of decision
ROI
radius of influence
SA
study area
SARA
Superfund Amendment and Reauthorization Act
SF
slope factor
SLUC
State land use covenant
STLC
soluble threshold limit concentrations
SSG
shallow soil gas less than 15 feet below ground surface
SVE
soil vapor extraction
SVOC
semi-volatile organic compound
svs
Small Volume Sites
TCDD
tetrachlorodibenzo-p-dioxin
TCE
trichloroethene
TEQ
toxicity equivalence
TMB
trimethylbenzene
TPH
total petroleum hydrocarbons
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
TPH-D
diesel-range total petroleum hydrocarbons
TPH-G
gasoline-range total petroleum hydrocarbons
TPH-JP4
jet fuel-range total petroleum hydrocarbons
TRV
toxicity reference value
TSCA
Toxic Substances Control Act
TTLC
total threshold limit concentrations
UST
underground storage tank
UTL
upper tolerance level
VOC
volatile organic compound
WQL
Water Quality Limit
Vlll
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
1.0
PART 1: THE DECLARATION
l.l
SITE NAME AND LOCATION
This Record of Decision (ROD) is for 45 Finding of Suitability for Early Transfer (FOSET) #2 Group 2
Action Sites at the former McClellan Air Force Base (AFB) Superfund Site in Sacramento, California. The
45 FOSET #2 Group 2 Action Sites consist of Installation Restoration Program (IRP) sites grouped
geographically in the area to the east and southeast of the airfield (Figure 1-1). These sites are referred to
as the Group 2 Action Sites. The Group 2 Action Sites come from larger site groupings known as the
Follow-on Strategic Sites (FOSS) and Small Volume Sites (SVS). The Remedial Investigation
Characterization Summaries (RICS) Addenda and Feasibility Study (FS) were completed by the Air Force
under these larger site groupings; however, most of the IRP sites from these groups that are located within
FOSET #2 are now being addressed through a private-sector cleanup by McClellan Business Park, LLC
(MBP). This ROD selects remedies for both volatile organic compound (VOC) contaminants in shallow
soil gas (depths less than 15 feet below ground surface [bgs]) and for non-VOC contaminants in soil within
15 feet bgs. The 45 sites included in this ROD are listed in Table 1-1.
Table 1-1 45 FOSET #2 Group 2 Action Sites
Follow-on Strategic Sites
Small Volume Sites
AOC 325
PRL T-033
CS P-005
PRL P-003
SA 048
SA 078
PRL L-001 (F2)
SA 043
CS P-006
PRL P-004
SA 053
SA 079
PRL L-005 (F2)
SA 044
CS S-021
PRL S-022*
SA 058
SA 081
PRL P-001
SA 073
CS S-027
PRL T-015
SA 059
SA 086
PRL S-037
SA 094
CS T-037
PRL T-019
SA 067
SA 098
PRL T-031
CS T-059
SA 037
SA 068
SA 101
PRL L-002
SA 038
SA 069*
SA 102
PRL L-003 (F2)
SA 040
SA 071
PRL L-004
SA 047
SA 077
Notes: * PRL S-022 and SA 069 are discussed together throughout this ROD, but are counted separately when
discussing the total number of sites as well as the number of sites with each selected remedy.
AOC area of concern
CS confirmed site
F2 the portion of the IRP site within FOSET #2
PRL potential release location
SA study area
The former McClellan AFB is listed on the U.S. Environmental Protection Agency's (EPA) National
Priorities List (NPL) and has a Federal Facilities Agreement (FFA) in place that governs investigation and
cleanup at this former military facility. McClellan AFB was listed on July 22, 1987 (EPA, 2007), National
Superfund database identification number CA4570024337. The primary Regulatory Agencies overseeing
the former McClellan AFB cleanup are EPA and the State of California Environmental Protection Agency,
represented by the Department of Toxic Substances Control (DTSC) and the Central Valley Regional Water
Quality Control Board (Central Valley Water Board). As described below, the Air Force has agreed in an
amendment to the FFA (the FFA Amendment) that EPA, in consultation with DTSC and the Central Valley
Water Board, will select response actions for the FOSET #2 Group 2 Action Sites.
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 101
— _PRL P-004
PRLT-015
SA 086
SA_079
LEGEND
CREEKS
Ol» f30UNDAR\
CftUMGMpr v
y'lTLfr
FOSET #2 GROUP 2
ACTION SITES
McCLELLAN BUStNESS PARK
SACRAMENTO, CALIFORMA
Figure 1-1 FOSET #2 Group 2 Action Sites Locations
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
1.2 STATEMENT OF BASIS AND PURPOSE
This ROD presents the selected remedies for soil and shallow soil gas at depths less than 15 feet bgs on the
45 Group 2 Action Sites that were recommended for further action in the FOSET #2 Group 2 Action Sites
Proposed Plan (Proposed Plan; EPA, 2017a) within 525 acres of the former McClellan AFB Superfund
Site, referred to as the "FOSET #2 Property," and addresses public comments on the Proposed Plan. EPA
issued the Proposed Plan as part of its public involvement responsibility under the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA) Section 117 and Part 300.430(f)(2)
of the National Oil and Hazardous Substances Pollution Contingency Plan (NCP). The Proposed Plan and
this ROD address the community involvement requirements of CERCLA.
The FOSET #2 Property was included in the third portion of the former McClellan AFB selected for early
transfer with privatized cleanup ("privatization"). Pursuant to CERCLA and Executive Order 12580, the
Air Force is responsible for environmental restoration at its facilities. At facilities which are listed on
EPA's NPL, EPA and the Air Force jointly select the remedy with the concurrence of DTSC and the Central
Valley Water Board under the terms of a FFA. Although CERCLA generally requires the Air Force to
complete the cleanup of contamination prior to the transfer of property, it also allows the Air Force to
transfer property before it has been cleaned up with the approval of EPA and the Governor of the State of
California. This process, which is documented in a FOSET, requires the Air Force to provide assurances
that the necessary remedial action will be completed. At former McClellan AFB, the Air Force entered
into an agreement with the new owner of the property, MBP and the County of Sacramento, to fund the
cleanup. MBP will conduct the cleanup of contamination within the first 15 feet bgs of soil pursuant to the
terms of an Administrative Order on Consent (2013 AoC) with EPA, DTSC, and the Central Valley Water
Board. The FFA was amended in May 2007 to suspend the obligation of the Air Force to conduct the
cleanup of the sites transferred under the privatized FOSET and document the Air Force's agreement that
EPA, in consultation with DTSC and the Central Valley Water Board, shall select remedies for the FOSET
Sites. Therefore, EPA has selected the remedy for these 45 Group 2 Action Sites within the property
transferred under FOSET #2.
As described in the 2013 AoC and the 2007 FFA Amendment, the Air Force retains the responsibility for
cleanup of groundwater and existing contamination, pollution, or other environmental conditions deeper
than 15 feet bgs. Groundwater contamination is present below the FOSET #2 Property, and is being
addressed under the 2007 Final Basewide VOC Groundwater Record of Decision (VOC Groundwater
ROD; Air Force Real Property Agency [AFRPA], 2007) and the Non-VOC Amendment to the Basewide
VOC Groundwater Record of Decision (Non-VOC ROD Amendment; AFRPA, 2009) and is, therefore, not
covered by this ROD. The threat to groundwater from VOCs at several of the sites in FOSET #2 is currently
being addressed through soil vapor extraction (SVE) as selected in the VOC Groundwater ROD, and is
therefore not addressed by this ROD (AFRPA, 2007). Potential VOC impacts to groundwater will continue
to be addressed at these sites using SVE until an SVE termination and optimization process decision is
made per the VOC Groundwater ROD (AFRPA, 2007).
If, during implementation of the FOSET #2 remedial activities, MBP finds soil contamination exceeding
cleanup levels deeper than 15 feet bgs (which is defined as a "Retained Condition" in the 2013 AoC), the
AoC recognizes the Environmental Services Cooperative Agreement (ESCA) process, in which MBP (on
behalf of the County of Sacramento) consults with the Air Force on how to address the Retained Condition
(AFRPA, 2012b). Pursuant to the ESCA and as recognized in the 2013 AoC, the Air Force (with the
approval of EPA, MBP and the County of Sacramento) may choose to treat the Retained Condition as an
"Added Condition" under the AoC, in which case the AoC shall govern the response action to be
implemented by MBP and the funding for such action shall be paid by the Air Force though the ESCA. To
the extent necessary due to the scope of the discovered Retained Condition, the Air Force retains the
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
responsibility for addressing any remedial change in accordance with 40 CFR [Code of Federal
Regulations] 300.435(c).
The remedies for the FOSET #2 Property were selected in accordance with CERCLA, as amended by the
Superfund Amendment and Reauthorization Act (SARA), and the NCP. The decision documented in this
ROD is based on the Administrative Record for the former McClellan AFB, which has been developed in
accordance with §113(k) of CERCLA, 42 U.S.C. §9613(k). The Administrative Record Index identifies
all the items that support the remedy selection. The FOSET #2 Group 2 Action Sites ROD will become part
of the Administrative Record for the former McClellan AFB.
1.3 ASSESSMENT OF THE SITES
The FOSET #2 Group 2 Action Sites include 45 IRP sites previously identified by the Air Force. As a
result of past industrial activities at the Property, hazardous substances or contaminants have been released
to the soil in this area or have migrated from a different area. The response action selected in this ROD is
necessary to protect the public health and welfare of the environment from actual or threatened releases of
hazardous substances. There are 78 additional IRP sites covered by FOSET #2 (original Action Sites and
No Further Action [NFA] sites); remedies have already been selected for those sites by EPA in other RODs.
The contamination at the site includes VOC and Non-VOC contaminants of concern. VOCs include many
chlorinated solvents and petroleum-related compounds. Non-VOCs include semi-volatile organic
compounds (SVOCs), metals, and petroleum hydrocarbons. SVOCs addressed in this ROD include
polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dioxins/furans, and
pesticides. Petroleum hydrocarbons include two primary classes of compounds: total petroleum
hydrocarbons (TPH) as diesel (TPH-D) and as gasoline (TPH-G). Petroleum product contamination is
exempt from CERCLA; however, EPA guidance states that if petroleum product contamination is
commingled with CERCLA-regulated contamination, the petroleum contamination is also addressed under
CERCLA. Because the TPH contamination at the FOSET #2 Property was assumed to be commingled
with other CERCLA contaminants, the TPH contamination is addressed in this ROD. The Central Valley
Water Board intends to administratively close underground storage tanks (USTs) and oil and water
separators (OWSs) that have not previously been closed.
1.4 DESCRIPTION OF SELECTED REMEDIES
EPA selected the remedies for the FOSET #2 Group 2 Action Sites based on the site-specific
characterizations detailed in the Small Volume Sites RICS Addenda and FS (CH2MHill, 2011) and the
Follow-on Strategic Sites RICS and FS (CH2MHill, 2012).
The selected remedies address:
• VOCs in shallow soil gas (SSG) that may present a threat to human health through the vapor
inhalation pathway; and
• Non-VOCs in soil that may present a threat to human health through direct contact, inhalation, or
ingestion, or that may present a threat to groundwater or surface water quality protection.
Individual site characteristics and risk summaries for each of the sites (found in Section 2.5) and the selected
remedies for the FOSET #2 Group 2 Action Sites are presented in Tables 2-1 and 2-2. The tables highlight
site contaminants of concern (COCs) exceeding cleanup levels. The final selected remedies for the FOSET
#2 Group 2 Action Sites generally use cleanup levels for industrial or industrial/commercial land uses,
which are the current and reasonably anticipated future use of the FOSET #2 Property. The FOSET #2
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Group 2 Action Sites were selected based on the need to actively remediate non-VOC contamination. Many
FOSET #2 Group 2 Action Sites have both VOC and non-VOC remedies.
The selected remedies will provide protection to human health and the environment by either removing
contaminants from the sites, thereby reducing residual risk, or by limiting exposure to human receptors by
implementing engineered and institutional controls (ECs and ICs). Sites requiring ECs or ICs will be
available for restricted use. Group 2 Action Sites with both VOC and non-VOC contamination have two
selected remedies, one for each set of contaminants. Alternative 1, No Further Action, was evaluated for
each Action Site in the FS documents (CH2MHill, 2011, and 2012), which is required as a baseline for
comparative analysis of the other remedy alternatives.
1.4.1 Alternative VOC2 - Institutional Controls to Restrict Land Use
Alternative VOC2 has been selected for the 19 FOSET #2 Group 2 Action Sites listed below:
Confirmed Site (CS) CS P-005
• SA 040
•
SA 073
CS T-059
• SA 043
•
SA 077
Potential Release Location (PRL) P-003
• SA 047
•
SA 086
PRL S-037
• SA 048
•
SA 094
PRL T-015
• SA 059
•
SA 098
Study Area (SA) 037
• SA 068
SA 038
• SA 071
Ten of the 19 sites chosen for Alternative VOC2 also require Alternative Non-VOC2: CS P-005, SA 038,
SA 040, SA 043, SA 047, SA 059, SA 071, SA 073, SA 086, and SA 094.
Soil contamination at one site chosen for Alternative VOC2 will be addressed by Alternative Non-VOC4a:
PRL T-015.
ICs are non-engineered instruments such as administrative and/or legal controls that minimize the potential
for human exposure to contamination by limiting land or resource use (such as permits, zoning, and/or deed
restrictions). The ICs associated with Alternative VOC2 are intended to minimize the potential for human
exposure to soil gas contamination at levels exceeding EPA's risk management range within the upper 15
feet bgs by prohibiting residential and sensitive receptor (e.g., daycares, public or private schools for
persons under 18 years of age, hospitals, etc.) uses.
The future land use is expected at this time to be industrial or commercial. The maintenance, monitoring,
enforcement, and reporting of the selected ICs will be protective of human health and the environment and
comply with applicable or relevant and appropriate requirements (ARARs). The ICs selected under
Alternative VOC2 will restrict land use such that homes, day care centers, health care centers, and public
or private schools for persons under 18 years of age may not be constructed on the contaminated portion of
the property. The use restrictions will be implemented through inclusion in the property deeds and state
land use covenants (SLUCs) recorded on the property, which will be enforced by DTSC and the Central
Valley Water Board. Alternative VOC2 includes monitoring and enforcement of the ICs. The site features
maps for each site (see figures in Attachment D) show the associated IC compliance boundaries, which
apply to the legal lot(s) in which each applicable FOSET #2 Group 2 Action Site is located. The IC
compliance boundaries define the extent of the area to which ICs are applicable.
5
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
1.4.2
Alternative VOC3 - ICs to Restrict Land Use and Engineered Controls (ECs) to
Mitigate Shallow Soil Gas Contamination
Alternative VOC3 has been selected for the 23 FOSET #2 Group 2 Action Sites listed below:
Area of Concern (AOC) 325
PRL L-004
PRL L-005 (F2)
PRL P-004
PRL S-022 & SA 069
• SA 058
• SA 067
• SA 079
• SA 081
• SA 101
• SA 102
CS P-006
CS S-021
CS S-027
CS T-037
PRL T-031
PRL T-033
SA 044
PRL L-001 (F2)
PRL L-002
PRL L-003 (F2)
SA 053
Nine of the 23 sites chosen for Alternative VOC3 also require Alternative Non-VOC2: AOC 325, CS P-
006, PRL L-001 (F2), PRL L-002, PRL L-003 (F2), PRL T-031, PRL T-033, SA 079, and SA 102.
Soil contamination at four sites chosen for Alternative VOC3 will be addressed by Alternative Non-VOC4a:
PRL L-004, PRL S-022 & SA 069, and SA 081. Sites PRL S-022 and SA 069 are addressed together due
to their close proximity, similar COCs, and their combined investigations under the RICS.
Land use activity restrictions will be used to reduce the human exposure potential from VOCs in SSG in
buildings and the impact to occupants via vapor inhalation pathways. This remedy will restrict residential
or sensitive land use as described for Alternative VOC2 through the use of the same types of IC mechanisms
(i.e., deeds and SLUCs). In addition to the ICs, Alternative VOC3 will require the installation of approved
ECs (such as vapor barriers, gas collection systems, and/or ventilation systems) in any future buildings or
during significant remodeling of existing buildings (e.g., remodeling that requires replacing major portions
of the foundation or floor) at these sites. Vapor controls will be required unless new sampling indicates
that SSG IC compliance levels in Table 2-5 are not exceeded, or a risk assessment based on new sampling
is performed to evaluate the risk posed under CERCLA and the NCP. Any waiver of vapor controls would
have to be approved by EPA, in consultation with DTSC and the Central Valley Water Board. The selection
of the controls to be implemented will be based on whether the controls are to be implemented on an existing
building or future construction. For existing buildings, the building design, foundation type (e.g., slab,
raised, etc.), and function of the building (e.g., warehouse, office building, etc.) will be used to determine
the most appropriate type of EC in the approved work plan. For new buildings, a vapor barrier is assumed
to be the most appropriate type of EC; however, this will ultimately be determined during the building
design phase and approved by EPA, in consultation with DTSC and the Central Valley Water Board. The
specific IC compliance boundaries and the restrictions to be incorporated into the ICs are identified in the
site-specific figures in Attachment D and Table 2-7, respectively. The IC compliance boundaries define
the extent of the area to which ICs are applicable. Because of the potential for migration of shallow soil
gas, sites where VOC3 is selected also include a 100-foot buffer zone. The 100-foot buffer zone can be
reduced or eliminated if there is SSG data that demonstrates there is no SSG contamination above the IC
compliance levels in an area.
1.4.3 Alternative Non-VOC2 - ICs to Restrict Land Use, ECs, and Monitoring
Alternative Non-VOC2 has been selected for the 22 FOSET #2 Group 2 Action Sites listed below:
• AOC 325
• CSP-005
• CS P-006
• PRL T-031
• PRL T-033
• SA 038
• SA 073
• SA 078
• SA 079
6
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
• PRL L-001 (F2)
• PRLL-002
• PRL L-003 (F2)
• SA 040
• SA 043
• SA 047
• SA 059
• SA 071
• SA 086
• SA 094
• SA 102
• PRLP-001
• PRL T-019
Ten sites chosen for Alternative Non-VOC2 also require Alternative VOC2: CS P-005, SA 038, SA 040,
SA 043, SA 047, SA 059, SA 071, SA 073, SA 086, and SA 094.
Nine sites chosen for Alternative Non-VOC2 also require Alternative VOC3: AOC 325, CS P-006, PRL
L-001 (F2), PRL L-002, PRL L-003 (F2), PRL T-031, PRL T-033, SA 079, and SA 102.
ICs and ECs will be used to eliminate or limit exposure pathways for non-VOCs to human receptors and
the environment. The specific type of controls and monitoring required for a particular site will depend on
the specific characteristics of the site such as the type of contaminants, how people might come in contact
with the contaminants, the risk associated with the contaminants, and whether the contaminants could
migrate offsite. Monitoring will be implemented in conjunction with, and in support of, other remedies
such as ICs and ECs. The monitoring would be used to show that the remedy protects human health and
the environment.
ICs will consist of any or all of the following: a prohibition on sensitive uses of the property (as described
under Alternative VOC2), a prohibition on building slab removal without agency approval, or a prohibition
on intrusive activities (such as digging, removal of existing surface covers [e.g., landscaping, pavement,
gravel, etc.]) without agency approval. The specific IC compliance boundaries and the restrictions to be
incorporated into the ICs are identified in the site-specific figures in Attachment D and Table 2-7,
respectively. The IC compliance boundaries define the extent of the area to which ICs are applicable.
ECs will consist of surface cover and/or sediment collection. The maintenance or expansion of existing
surface cover (including concrete, asphalt, and building foundations) will be implemented to reduce or
eliminate the direct contact pathway and/or potential impacts to surface water. Prefabricated sediment traps
will be installed in areas that collect and/or channel storm water runoff to trap and remove residual sediment
before it enters natural surface water features (such as creeks). The surface cover EC will achieve remedial
action objectives (RAOs) immediately upon installation. The sediment collection EC will require
maintenance and monitoring to evaluate performance and protectiveness. If current buildings will be
demolished or remodeled or if other soil cover is removed, then soil sampling would be required. If the
results of sampling are above the cleanup levels prescribed in the ROD, then a surface cover would be
required to prevent the non-VOC contamination from impacting surface water quality and human health.
The specific ECs and required monitoring are identified in the site-specific figures in Attachment D and
Table 2-8, respectively.
1.4.4 Alternative Non-VOC4a - Excavation and Disposal and ICs to Restrict Land Use
Alternative Non-VOC4a has been selected for the five following sites: PRL L-004, PRL S-022 & SA 069,
PRL T-015, and SA 081. All of these sites will be remedied in combination with Alternative VOC3, with
the exception of PRL T-015, which will be remedied in combination with Alternative VOC2. TPH
contamination below 15 feet bgs at these sites is an Air Force Retained Condition and is not addressed in
Under Alternative Non-VOC4a, the FOSET #2 Group 2 Action Sites with contaminated soil and/or
sediment within the upper 15 feet bgs above industrial use cleanup levels and/or water quality protective
cleanup levels will be excavated, and the excavated soil will be transported to an appropriate facility for
this ROD.
7
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
disposal. Water quality protective cleanup levels are soil cleanup levels that were established by the Central
Valley Water Board to protect surface water or groundwater quality. For example, surface soil with
concentrations above the water quality protective levels could impact ecological receptors if contaminated
soil erodes and is transported to a surface water body. Alternative Non-VOC4a also may include treatment,
if required to meet landfill disposal requirements, of some of the excavated soil prior to disposal. All soil
containing concentrations of contaminants above restricted use levels will be removed and the resulting
land use is restricted to prohibit residential or sensitive land use as described above for Alternative VOC2.
Alternative Non-VOC4a also includes ECs (such as maintaining the existing surface cover or sediment
collection) as necessary, ICs, and monitoring as described in detail in Section 2.9. The ICs are the same as
those in Alternative VOC2 and will also be implemented through deed restrictions and SLUCs. In addition,
deed restrictions and SLUCs will include digging restrictions for sites where surface cover must be
maintained, as indicated in Table 2-7. The site features maps for each site (see figures in Attachment D)
show the associated IC compliance boundaries, which apply to the legal lot(s) in which each applicable IRP
site is located. The IC compliance boundaries define the extent of the area to which ICs are applicable.
1.4.5 Summary of the Selected Remedies
The selected remedies for the FOSET #2 Group 2 Action Sites are summarized in Table 1-2 and are
described further in Section 2.12.
Table 1-2 Selected Remedies for FOSET #2 Group 2 Action Sites
Silo \:ime
So Ice led
Remedy
C()(
s Addressed
Remedy
Description
YOCs ill SS(;
Soil
Chloroform
Benzo(a)pyrene
AOC 325
VOC3 and
ICs/ECs and
Naphthalene
TPH-D
Non-VOC2
Monitoring
PCE
TCE
TPH-G
CS P-005
VOC2 and
Non-VOC2
ICs/ECs and
Monitoring
Naphthalene
PCE
1.2.4-TMB
1.3.5-TMBA
Aroclor 1260A
Dieldrin*
Dioxins/Furans*
Benzene
Chloroform
Cis-1,2-DCE
CS P-006
VOC3 and
Non-VOC2
ICs/ECs and
Monitoring
1,2-DCA
Ethylbenzene
Naphthalene
PCE
TCE
1.2.4-TMB
1.3.5-TMB
Vinyl chlorideA
CadmiumA
Chrysene*
Dioxins/FuransA
TPH-D*
8
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo \:1111c
So Ice led
Remedy
Remedy
Description
( OC s Addressed
YOCs ill SS(;
Soil
CS S-021
VOC3
ICs/ECs
Carbon Tetrachloride
Chloroform
1,4-DCB
Ethylbenzene
PCE
TCE
None
CS S-027
VOC3
ICs/ECs
1,4-DCB
Naphthalene
PCE
TCE
1.2.4-TMB
1.3.5-TMB
None
CS T-037
VOC3
ICs/ECs
Carbon Tetrachloride
Chloroform
1,4-DCB
Ethylbenzene
PCE
TCE
None
CS T-059
VOC2
ICs
Naphthalene
None
PRLL-001
(F2)
VOC3 and
Non-VOC2
ICs/ECs and
Monitoring
Benzene
Chloroform
Chloro methane
Methylene chloride
Naphthalene
PCE
TCE
1,2,4-TMB
Vinyl chloride
Benzo(a)anthracene*
Benzo(a)pyrene*
Benzo(b)fluoranthene*
Benzo(k)fluoranthene*
Chrysene*
Dibenzo(a,h)anthracene*
Indeno( 1,2,3 -c,d)pyrene*
Lead*
PCBsA
TPH-G*
PRL L-002
VOC3 and
Non-VOC2
ICs/ECs and
Monitoring
Benzene
Carbon Tetrachloride
Chloroform
Cis-1,2-DCE
Ethylbenzene
Naphthalene
PCE
TCE
1.2.4-TMB
1.3.5-TMB
Xylenes
Cadmium*
Lead*
Benzo(a)pyreneA
TPH-G*
9
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo \:1111c
So Ice led
Remedy
C()(
s Addressed
Remedy
Description
YOCs ill ss<;
Soil
PRL L-003
(F2)
VOC3 and
Non-VOC2
ICs/ECs and
Monitoring
Benzene
Carbon Tetrachloride*
Chloroform
Naphthalene
PCE*
TCE*
CadmiumA
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Indeno( 1,2,3 -c,d)pyrene
Chrysene
Benzene
1,3-butadiene
Carbon Tetrachloride
Chloroform
1,4-DCB
PRL L-004
VOC3 and
Non-VOC4a
ICs/ECs;
Excavation and
Disposal-
Restricted Land
Use
Ethylbenzene
Hexane
Hexachlorobutadiene
Naphthalene
CadmiumA*
Lead*
TPH-D*
TPH-G
1,1,2,2-PCA
PCE
TCE
1.2.4-TMB
1.3.5-TMB
Vinyl chloride
Benzene
Chloroform
1,2-DCA
1,4-DCB
PRL L-005
(F2)
Ethylbenzene
VOC3
ICs/ECs
2-methylnaphthalene
None
Naphthalene
PCE
TCE
1.2.4-TMBA
1.3.5-TMBA
PRLP-001
Non-VOC2
ICs/ECs and
Monitoring
None
Aroclor-1254
Aroclor-1260
Benzene
PRL P-003
VOC2
ICs
Naphthalene
TCE
None
PRL P-004
VOC3
ICs/ECs
ChloroformA
TCEA
None
10
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo \:1111c
So Ice led
Remedy
C()(
s Addressed
Remedy
Description
YOCs ill SS(;
Soil
PRL S-022
&SA069
VOC3 and
Non-VOC4a
ICs/ECs;
Excavation and
Disposal-
Restricted Land
Use
Benzene
Carbon Tetrachloride
Chloroform
1,1,2,2-PCA
PCE
TCE
Benzo(a)anthracene
Benzo(a)pyrene
B enzo (f)fluoranthene
Chrysene
Naphthalene
TPH-DA
Benzene
1,3-Butadiene
PRL S-037
VOC2
ICs
Carbon Tetrachloride
1,1,2,2-PCA
PCE
None
PRLT-015
VOC2 and
Non-VOC4a
ICs/ECs;
Excavation and
Disposal-
Restricted Land
Use
BenzeneA
EthylbenzeneA
Naphthalene
PCE
TCE
1.2.4-TMB
1.3.5-TMBA
Arcolor-1260A
Benzo(a)anthraceneA
Benzo(a)pyreneA
Benzo(b)fluorantheneA
Benzo(k)fluorantheneA
NaphthaleneA
PRL T-019
Non-VOC2
ICs/ECs and
Monitoring
None
Thallium
Benzene
PRLT-031
VOC3 and
Non-VOC2
ICs/ECs and
Monitoring
Chloroform
NaphthaleneA
PCE
TCE
ManganeseA
VanadiumA
Aroclor-1254
PRL T-033
VOC3 and
ICs/ECs and
Benzene
Chloroform
Chloro methane
Naphthalene
Aroclor-1260
Benzo(a)anthracene*
Benzo(a)pyrene*
Benzo(b)fluoranthene*
Cadmium*
Chrysene*
CobaltA
Dibenzo(a,h)anthracene*
Indeno( 1,2,3 -c,d)pyrene*
LeadA*
Non-VOC2
Monitoring
PCE
TCE
1,2,4-TMB
Vinyl chloride
SA 037
VOC2
ICs
Chloroform
PCE
None
SA 038
VOC2 and
ICs/ECs and
Benzene
TPH-D
Non-VOC2
Monitoring
Chloroform
TPH-G
11
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo \:1111c
So Ice led
Remedy
Remedy
Description
( OC s Addressed
YOCs ill SS(;
Soil
SA 040
VOC2+ and
Non-VOC2
ICs/ECs and
Monitoring
None
CadmiumA*
CobaltA
Lead*
TPH-D*
SA 043
VOC2 and
Non-VOC2
ICs/ECs and
Monitoring
Naphthalene
Methylene chloride
PCE
Cadmium
Cobalt
Zinc
SA 044
VOC3
ICs/ECs
TCEA
None
SA 047
VOC2 and
Non-VOC2
ICs/ECs and
Monitoring
Chloroform
Naphthalene
PCE
CadmiumA*
CobaltA
LeadA*
SA 048
VOC2
ICs
Chloroform
Naphthalene
None
SA 053
VOC3
ICs/ECs
Benzene
Carbon Tetrachloride
Chloroform
Hexachlorobutadiene
Naphthalene
PCE
TCE
None
SA 058
VOC3
ICs/ECs
Benzene
Carbon Tetrachloride
Chloroform
Naphthalene
PCE
None
SA 059
VOC2 and
Non-VOC2
ICs/ECs and
Monitoring
Benzene
Hexachlorobutadiene
Naphthalene
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Chrysene*
SA 067
VOC3
ICs/ECs
Benzene
Chloroform
EthylbenzeneA
NaphthaleneA
PCEA
TCEA
None
12
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo \:1111c
So Ice led
Remedy
Remedy
Description
( OC s Addressed
YOCs ill SS(;
Soil
SA 068
VOC2
ICs
BenzeneA
Carbon Tetrachloride
ChloroformA
1,4-DCBA
EthylbenzeneA
NaphthaleneA
PCEA
TCE
None
SA 071
VOC2 and
Non-VOC2
ICs/ECs and
Monitoring
Benzene
Chloroform
CadmiumA*
PCBs*
SA 073
VOC2+ and
Non-VOC2
ICs/ECs and
Monitoring
None
LeadA
Benzo(a)pyreneA
PCBsA
SA 077
VOC2
ICs
Benzene
Carbon Tetrachloride
Chloroform
Ethylbenzene
Naphthalene
PCE
1,2,4-TMB
None
SA 078
Non-VOC2
ICs/ECs and
Monitoring
None
Lead*
TPH-D*
SA 079
VOC3 and
Non-VOC2
ICs/ECs
Chloroform
1,4-DCB
Ethylbenzene
Hexachlorobutadiene
Naphthalene
PCE
TCE
1.2.4-TMB
1.3.5-TMB
Vinyl Chloride
CadmiumA
SA 081
VOC3 and
Non-VOC4a
ICs/ECs;
Excavation and
Disposal-
Restricted Land
Use
Benzene
Chloroform
Ethylbenzene
Naphthalene
PCEA
TCEA
1.2.4-TMB
1.3.5-TMB
Vinyl chloride
Benzo(a)anthraceneA
Benzo(a)pyreneA
Benzo(b)fluorantheneA
CadmiumA*
ChryseneA Lead*
Naphthalene
2-methylnaphthalene
TPH-D
TPH-G
13
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo \:1111c
So Ice led
Remedy
C()(
s Addressed
Remedy
Description
YOCs ill SS(;
Soil
SA 086
VOC2 and
Non-VOC2
ICs/ECs and
Monitoring
Benzene
PCE
1.2.4-TMB
1.3.5-TMB
CadmiumA*
Lead*
TPH-D*
SA 094
VOC2 and
Non-VOC2
ICs/ECs and
Monitoring
Benzene
Naphthalene
Chrysene*
SA 098
VOC2
ICs
Chloroform
Naphthalene
None
SA 101
VOC3
ICs
ChloroformA
None
Benzene
Carbon Tetrachloride
Chloroform
Cis-1,2-DCE
1.4-DCB
SA 102
VOC3 and
Non-VOC2
ICs/ECs and
Monitoring
Ethylbenzene
Naphthalene
PCE
TCE
1.2.4-TMB
1.3.5-TMB
M,p-xylenes
O-xylene
2,4-DinitrotolueneA
PCBs*
Notes: Cleanup Levels and IC Compliance Levels are presented in Table 2-3 and Table 2-5, respectively. Levels for the
protection of surface water and groundwater for evaluation of ICs/ECs are presented in Table 2-4.
* indicates that contaminant was not identified as a COC in the RICS but was added based on protection of surface
water and/or groundwater quality. See the site-specific descriptions in Attachment D for more discussion.
A indicates that contaminant was not identified as a COC in the RICS but was added based on risk and/or exceeding
human health cleanup levels found in Tables 2-3 and 2-5. See the site-specific descriptions in Attachment D for more
discussion.
+ See Attachment D for the rationale for this remedy.
AOC
area of concern
CS
confirmed site
COC
contaminant of concern
DCA
dichloroethane
DCB
dichlorobenzene
DCE
dichloroethene
EC
engineered control
F2
the portion of the IRP site within FOSET #2
IC
institutional control
PAH
polycyclic aromatic hydrocarbon
PCA
tetrachloroethane
PCBs
polychlorinated biphenyls
PCE
tetrachloroethene
PRL
potential release location
SA
study area
SSG
shallow soil gas
TCE
trichloroethene
1MB
trimethylbenzene
TPH-D
total petroleum hydrocarbons in the diesel range
14
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
TPH-G
TPH-JP4
VOC
total petroleum hydrocarbons in the gasoline range
total petroleum hydrocarbons in the jet fuel range
volatile organic compound
1.5
STATUTORY DETERMINATIONS
EPA has selected the remedies for the FOSET #2 Group 2 Action Sites specified in Table 1-2. The response
actions selected in this ROD are necessary to protect public health or the environment from actual or
threatened releases of hazardous substances into the environment and from actual or threatened releases of
pollutants. The selected remedies are protective of human health and the environment, comply with federal
and state ARARs for the remedial actions, and are cost effective. The selected site remedies do not satisfy
the statutory preference for treatment as a principal element of the remedies because costs to achieve the
same risk reduction using treatment are significantly higher, treatment is not fiscally practical due to
extraordinarily high costs to address relatively low VOC concentrations in soil vapor, and because
contaminant concentrations in soil indicate that treatment would not be required to dispose of soil in a
permitted landfill.
The selected remedies for all of the sites will result in hazardous substances, pollutants, or contaminants
remaining onsite above levels that would allow for unlimited use and unrestricted exposure. Therefore, a
statutory review (i.e., a CERCLA Five-Year review) will be conducted within five years after initiation of
remedial action, and every five years thereafter, to ensure that the remedy is, or will be, protective of human
health and the environment. CERCLA five-year reviews will be required for all of the Group 2 Action
Sites. Other remedies implemented at the former McClellan AFB under other RODs also require five-year
reviews. All of the five-year reviews at the former McClellan AFB are performed on the same schedule
and documented in a single basewide report. The FOSET #2 Group 2 Action Sites will be included in the
basewide five-year review. The next review will occur in 2019, just after the signing of this ROD to
implement the selected remedies. Therefore, the first five-year review to evaluate protectiveness of the
FOSET #2 Group 2 Action Sites remedies will be in 2024 and every five years thereafter to ensure that the
remedies are, or will be, protective of human health and the environment.
The following information is included in the Decision Summary in Section 2.0 of this ROD. Additional
information can be found in the Administrative Record file for the FOSET #2 Property.
• Site descriptions and histories (Section 2.5, Table 2-1, and Attachment D);
• A summary of the risk represented by the COCs (Section 2.7, Table 2-2, and Attachment C);
• A list of the COCs and cleanup levels (Section 2.8.3, Table 2-3);
• Current and reasonably anticipated future land use assumptions and current and potential future
beneficial uses of land and groundwater used in the baseline risk assessment and ROD (Section
• Potential land and groundwater use that will be available following implementation of the remedial
action (Section 2.6);
• Estimated cost of the remedies (Section 2.12.7 and Table 2-9);
• The Principal Threat Wastes (Section 2.11); and
• The key factor(s) that led to selecting the remedies (Section 2.13).
1.6
DATA CERTIFICATION CHECKLIST
2.6);
15
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
This ROD was prepared in compliance with the guidance published by EPA for preparation of RODs (EPA,
1999).
16
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
1.7
AUTHORIZING SIGNATURES
The ROD documents the selected remedies for soil contamination at the FOSET #2 Group 2 Action Sites.
Pursuant to Section 111 of the 2010 Federal Facilities Agreement Amendment, EPA is selecting response
actions for the FOSET #2 Group 2 Action Sites, in consultation with DTSC and the Central Valley Water
Board. The Assistant Director of Federal Facilities and Site Cleanup Branch (EPA, Region 9) has been
delegated the authority to approve and sign this ROD.
Assistant Director of Federal Facilities and Site Cleanup Branch
Region 9, U.S. Environmental Protection Agency
State Acceptance
Tlic DTSC and the Central Valley Water Board had an opportunity to review and comment on the FOSET
#2 Group 2 Action Sites ROD, and their concerns have been addressed.
/
/
ANGELES II
'! Ci i h
iLES HERRERA
Date
MUFISEN NAZLMI
Bate
Deputy Director, Brownfieids and Environmental Restoration Program
Department of Toxic Substances Control
California Environmental Protection Agency
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2.0 PART 2: THE DECISION SUMMARY
This Decision Summary provides a description of the site-specific factors and analyses that led to the
selection of the remedies for the FOSET #2 Group 2 Action Sites. It includes background information
about the nature and extent of contamination and the rationale for the selection of the remedies.
2.1 SITE NAME, LOCATION, AND DESCRIPTION
The former McClellan AFB, which encompasses 3,452 acres, is located 7 miles northeast of downtown
Sacramento, California (Comprehensive Environmental Response, Compensation, and Liability
Information System [CERCLIS] Identification [ID] Number CA 4570024337 and Superfund Site ID
Number 0902759). Following the listing of the former McClellan AFB on the NPL, EPA, the California
Department of Health Services (now the Department of Toxic Substances Control), and the Air Force
entered into a FFA on May 2, 1990 (Department of the Air Force, 1990). The FFA identified the Air Force
as the lead agency and required the Air Force to identify, perform, and complete all necessary environmental
cleanup and response actions, including operation and maintenance (O&M) at the site under CERCLA.
Funds to complete the response actions for the FOSET #2 Group 2 Action Sites are being provided to MBP
by the Air Force through agreements with Sacramento County (AFRPA, 2012b).
The former McClellan AFB is surrounded by the City of Sacramento to the west and southwest,
unincorporated areas of Antelope on the north, Rio Linda on the northwest, and North Highlands on the
east.
From 1936 until 2001, McClellan AFB was an aircraft repair depot and supply base. On July 22, 1987, all
of McClellan AFB, including the FOSET #2 Property, was added to the NPL as a site with known releases
or threatened releases of hazardous substances, pollutants, or contaminants that warranted further
investigation and cleanup under CERCLA.
The predominant current land uses at the former McClellan AFB are industrial, aviation, commercial, and
residential. There are also open areas, some of which are relatively large. Land parcels designated for
commercial, office, and industrial uses are interspersed around the Property and are used for shopping
centers, office complexes, military operations (U.S. Coast Guard), rescue training, schools, and warehouses.
The FOSET #2 Group 2 Action Sites are located east and southeast of the runway at former McClellan
AFB (Figure 1-1). The FOSET #2 Group 2 Action Sites do not currently have any residential areas and
only minimal ecological habitat.
2.2 SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.2.1 Site History
McClellan AFB was an active industrial facility since its dedication in 1936, when it was called the
Sacramento Air Depot. Operations changed from the maintenance of bombers during World War II and
the Korean War to the maintenance, repair, modification, and disassembly of jet aircraft in the 1960s. More
recently, operations were expanded to include the maintenance and repair of communications equipment
and electronics. Hazardous substances were utilized at a number of facilities on-base, including disposal
pits, washracks, fuel and oil storage, electronics repair and testing facilities, aircraft painting facilities,
wastewater treatment plants, machine shops, and open storage areas. In 1995, the Congressional Base
Realignment and Closure (BRAC) Commission recommended closure of McClellan AFB; and on July 13,
2001, McClellan AFB was closed as an active military facility.
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
The FOSET #2 Group 2 Action Sites include former aircraft repair, testing, and support facilities; fuel
storage and distribution facilities; storage areas; and waste handling and treatment areas. A summary of
the history for each site can be found in Table 2-1 and Attachment D.
2.2.2 Previous Investigations
In response to detections of contaminants in soil and groundwater, the Air Force initiated the first phase of
the IRP in 1981. Under the IRP, the investigation and remediation of contamination at the Property has
been conducted in accordance with CERCLA as amended by SARA and the NCP. The principal data
collection and analysis components of the restoration program are the remedial investigations (RIs) at the
IRP sites. The RIs are the primary source of site characterization data for the FOSET #2 Group 2 Action
Sites.
Several phases of investigation have been conducted at each Action Site. Generally, the media collected
during the sampling events included soil, soil gas, and groundwater. Information on site history,
investigations performed, COCs, and resulting risk is discussed by site in Table 2-1 and Table 2-2. The
results of all RIs were summarized and potential remedies evaluated in the Small Volume Sites RICS
Addenda and FS (CH2MHill, 2011), the Follow-on Strategic Sites RICS and FS (CH2MHill, 2012), the
Small Volume Sites FS Addendum (EPA, 2016b), and the Follow-on Strategic Sites FS Addendum
(EPA, 2016c).
Removal actions have occurred at some ofthe FOSET #2 Group 2 Action Sites, including removal of USTs,
bioventing systems to address TPH contamination, and operation of SVE systems to address soil vapor
contamination that could impact groundwater. Information regarding past removal actions is summarized
in Section 2.4.1 and additional information can also be found in Attachment B.
2.2.3 Enforcement Activities
Following the listing of the former McClellan AFB on the NPL, EPA, the State California Department of
Health Services (now the Department of Toxic Substances Control), and the Air Force entered into an FFA
on May 2, 1990 (Department of the Air Force, 1990). The FFA identified the Air Force as the lead agency
and required the Air Force to identify, perform, and complete all necessary environmental cleanup and
response actions, including O&M at the site under CERCLA.
2.2.4 Base Closure and Privatization
Cleanup under the FOSET #2 Group 2 Action Sites ROD is being addressed through the process of
privatization. In conjunction with the Early Transfer of the property and the execution of the 2013 AoC
with the transferee, the FFA was amended on August 23, 2011, to suspend the obligation of the Air Force
to conduct the response actions associated with the FOSET #2 Property (AFRPA, 2011a). MBP is the
current owner of the property and is responsible under the terms of the 2013 AoC for the implementation
of remedial activities associated with SSG, soil, and subsurface soils to a depth of 15 feet bgs at the FOSET
#2 property. TPH contamination below 15 feet bgs at four sites is an Air Force Retained Condition and is
not addressed in this ROD.
Funds to complete the response actions for the FOSET #2 Group 2 Action Sites are being provided to MBP
by the Air Force through agreements with Sacramento County (AFRPA, 2012b). The Air Force retains
responsibility for the groundwater and soil contamination below a depth of 15 feet bgs and, if the selected
remedy is not completed by MBP under the 2013 AoC, the obligation of the Air Force under the FFA is
restored.
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
2.3 COMMUNITY PARTICIPATION
The former McClellan AFB has had an active community relations/public participation program since the
beginning of restoration activities in the early 1980s. The purpose of the program is to help community
members understand the former McClellan AFB's cleanup program and to learn how to become involved
in the cleanup decision-making process.
From the initial FOSET #2 planning stages prior to the transfer of the property and cleanup obligations,
EPA, DTSC, and the Central Valley Water Board have invited the community to participate in the cleanup
decision-making process and have kept the community informed through oral and published
communications. In an effort to keep residents and tenants informed of plans, activities, and findings, the
following procedures have been or will be implemented to facilitate an ongoing dialogue with
the community.
2.3.1 Community Interviews and Fact Sheet
In August 2017, two interviews were conducted with key MBP stakeholders. Information and suggestions
provided through the interviews are used to improve communication methods, community involvement in
the cleanup and to address concerns. Interviewees were asked a variety of questions about their personal
history, their understanding of MBP, and their preferred methods of communication regarding the Sites. A
Fact Sheet was developed and distributed in April 2017. For additional information, including a full list of
the interview questions, refer to the Appendices of the Community Involvement Plan (EPA, 2018).
2.3.2 Community Involvement Plan
The Final Community Involvement Plan (CIP) for McClellan Business Park, March 2018 (the 2018 CIP)
presents EPA's plan for addressing issues and concerns identified in August 2017 interviews. The CIP relies
on tools and techniques that EPA has developed over the years at hundreds of Superfund sites. The 2018
CIP includes EPA's Environmental Justice Screening and Mapping Tool (EJ Screen) to obtain pertinent
demographic information for an area within 1.5-mile radius of the former McClellan AFB privatized
cleanup, including the cleanup of the FOSET #2 Group 2 Action Sites. The 2018 CIP identified several
issues of concern associated with the completion of the environmental cleanup, property transfer and
complicated land use restrictions. More information is provided in Section 3.0, Responsiveness Summary,
and in the 2018 CIP.
2.3.3 Public Notifications
In April 2017, EPA ran a print ad in The Sacramento Bee announcing the release of the Proposed Plan
(EPA, 2017a). The notice invited the surrounding communities to attend an availability session and apublic
meeting on April 20, 2017, and it announced that comments on the Proposed Plan would be collected during
a 30-day comment period. The print ad also identified where copies of the Proposed Plan and the site
documents, including the RICS and FS, could be obtained for further information and review.
2.3.4 FOSET #2 Group 2 Action Sites Proposed Plan
The Proposed Plan had a two-fold purpose: 1) to present alternatives to the public that were being
considered for cleanup of the FOSET #2 Group 2 Action Sites and 2) to request public input on those
alternatives. The preferred cleanup alternatives were specifically identified and the public was requested
to submit comments and concerns during the comment period, which opened on April 10, 2017 and closed
on May 10, 2017.
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2.3.5 FOSET #2 Group 2 Action Sites Proposed Plan Outreach
A Fact Sheet summarizing the FOSET #2 Group 2 Action Sites Proposed Plan was distributed by mail to
residents and businesses within a quarter-mile radius surrounding the FOSET #2 Group 2 Action Sites and
to persons on EPA's former McClellan AFB mailing list. Also contained within the Proposed Plan was an
invitation to learn more about the FOSET #2 Group 2 Action Sites cleanup at the availability session and
public meeting held on April 20, 2017, at the North Highlands Recreation Center.
The Fact Sheet was mailed to approximately 1,000 on- or near-base recipients and also served to notify the
public about the Proposed Plan and the opportunity for public comment.
2.3.6 FOSET #2 Group 2 Action Sites Proposed Plan Public Meeting
Representatives from county, state, and federal agencies were available to discuss the Proposed Plan during
an Availability Session held on April 20, 2017 at the North Highlands Recreation Center. EPA formally
presented the Proposed Plan and written and oral comments were formally documented during the Public
Meeting Session. Comments were collected through May 10, 2017 and considered during development of
the ROD. No written comments were received on the Proposed Plan, but public comments were presented
verbally at the public meeting. Responses to public comments are found in Section 3.0 - Responsiveness
Summary.
2.3.7 EPA Participation in Outreach Events
EPA attends community events to distribute information about projects and answer questions at an
information booth or table. In addition, EPA coordinates with local municipal, environmental, or civic
groups to provide information at special events.
EPA also periodically participates in local and municipalities group meetings to provide the public with
updates on the privatized cleanup of McClellan Business Park.
2.3.8 Restoration Advisory Board
Quarterly Restoration Advisory Board (RAB) meetings offer opportunities for the public to learn about
environmental restoration and to become involved in the redevelopment process. These meetings are
specifically designed for the public to voice concerns, ask questions, and raise issues about the cleanup
process. The public is encouraged to serve on the RAB, representing the interests of various parts of the
community, such as local residents, students, or environmental groups. Representatives from county, state,
and federal agencies, MBP, and other community members also participate in the meetings.
2.3.9 Information Repositories
Information is available to facilitate discussion on environmental cleanup at the following websites.
• EPA: www.epa.gov/region09/McClellanAFB
• Air Force: http://afcec.publicadmin-record.us.af.mil/
• DTSC: www.envirostor.dtsc.ca.gov
• Central Valley Water Board: geotracker.waterboards,ca.gov
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
2.3.10 Administrative Record
Copies of documentation pertaining to the FOSET #2 Property cleanup are available at the following
locations:
EPA Region 9 Superfund Records Center
95 Hawthorne Street, Suite 403 S
San Francisco, California 94105
Telephone: 415-536-2000
Hours: Monday - Friday 8 a.m. to 5 p.m.
Air Force Repository
AFCEC/CIBW
3411 Olson Street
McClellan, California 95652-1071
Telephone: 916-643-1250 x239
2.4 SCOPE AND ROLE OF FOSET #2 GROUP 2 ACTION SITES RESPONSE
ACTIONS
For environmental management purposes, the Air Force has subdivided the former McClellan AFB into the
following 11 operable units (OUs): A, B, Bl, C, CI, D, E, F, G, H, and Groundwater, which encompasses
the entire Property.
However, because of the complexity of different types of contaminants commingling at the former
McClellan AFB, the presence of contamination in the soil, soil gas, sediment, and groundwater, and the
large extent of contamination across the former McClellan AFB, the investigation and remediation of
contamination at the former McClellan AFB has been subdivided into several projects based on geographic
areas and/or media. This subdivision allows for more efficient planning and implementation of each
project.
Several RODs have been completed at the former McClellan AFB, as follows:
• No Further Action ROD (AFRPA, 2003) addresses six sites that that have no soil contamination.
No remedies were required for these sites.
• Local Reuse Authority Initial Parcel ROD #1 (IP #1 ROD, AFRPA, 2004) addresses non-VOC
contaminants in soil at seven sites. The remedies under the IP #1 ROD have been implemented.
• VOC Groundwater ROD (AFRPA, 2007) addresses basewide VOC contamination in groundwater
and soil gas in the vadose zone that threatens groundwater. The VOC Groundwater ROD
established cleanup requirements for groundwater remedies and SVE that had previously been
implemented as removal actions and interim remedies. The remedies specified in the VOC
Groundwater ROD have been implemented.
• Non-VOC ROD Amendment (AFRPA, 2009) addresses non-VOC contamination in groundwater.
The remedies under the Non-VOC ROD Amendment have been implemented.
• Local Reuse Authority Initial Parcel ROD #2 (IP #2 ROD, AFRPA, 2008) addresses non-VOC and
VOC contaminants in soil and shallow soil gas at 16 sites and VOC contaminants in shallow soil
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
gas at seven sites included in Initial Parcel ROD #1. The remedies under the IP #2 ROD have been
implemented.
• Parcel C-6 ROD (EPA, 2009) addresses non-VOC and VOC contaminants in soil and shallow soil
gas at 12 sites on the first privatization parcel. The remedies under the Parcel C-6 ROD have been
implemented.
• Area of Concern G-l ROD (AOC G-l ROD, AFRPA, 2010) addresses non-VOC and VOC
contaminants in soil and shallow soil gas at site AOC G-l. The remedy under the AOC G-l ROD
has been implemented.
• Former Skeet Range ROD (Skeet Range ROD, AFRPA, 2011b) addresses cleanup of lead and
PAHs in surface soils at the former skeet range. The remedy under the Skeet Range ROD has been
implemented.
• Focused Strategic Sites ROD (FSS ROD, AFRPA, 2012c) addresses radiological, non-VOC, and
VOC contaminants in soil and shallow soil gas at 11 sites. Collectively, the 11 sites contain the
largest volume of wastes at the former McClellan AFB. The remedies under the FSS ROD are
being implemented and will be completed when the Consolidation Unit (CU) is closed in 2020.
Under the FSS ROD, a CU is being constructed at the former McClellan AFB for disposal of
contaminated soil and sediment.
• Local Reuse Authority Initial Parcel ROD #3 (IP #3 ROD, EPA, 2012) addresses non-VOC and
VOC contaminants in soil and shallow soil gas. The IP #3 ROD covers 49 sites located in the
southwestern and eastern portions of the former McClellan AFB. The remedies under the IP #3
ROD have been implemented and were completed in 2016.
• Ecological Sites ROD (AFCEC, 2013) addresses contaminants in soil and sediment at 12 sites with
ecological habitat, such as creeks and vernal pools. The remedies under the Ecological Sites ROD
were implemented and completed during the 2014 field season.
• Follow-on Strategic Sites (FOSS) ROD (AFCEC, 2014) was completed in 2014 and addresses non-
VOC and VOC contaminants in soil and shallow soil gas at 88 sites located around and to the west
of the airfield. The remedies under the FOSS ROD are currently being implemented.
• The Action Sites ROD (EPA, 2015) was completed in 2015 and addresses non-VOC and VOC
contaminants in soil and shallow soil gas at 43 FOSET #2 sites located east and south of the airfield.
The Final Remedial Design/Remedial Action (RD/RA) Work Plan was completed in 2015 and the
remedies for the Action Sites are currently being implemented.
• The No Further Action Sites ROD (EPA, 2016a) was completed in 2016 and 35 FOSET #2 sites
located east and south of the airfield. NFA was selected as the remedy for these sites because risk
levels are below or within the risk range, and there are no threats to groundwater or surface water
quality. No additional actions are anticipated for these sites.
The remaining IRP sites at the former McClellan AFB are grouped geographically or, because of similar
attributes, into the following RODs:
• The FOSET #2 Group 2 Action Sites ROD (this ROD) addresses non-VOC and VOC contaminants
in soil and shallow soil gas at 45 FOSET #2 sites located east and southeast of the airfield.
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
• The Group 4 ROD will address non-VOC and VOC contaminants in soil and shallow soil gas at 16
sites. The sites are located east of the flight line and north of Palm Avenue. The Group 4 ROD is
planned for completion by EPA in 2019.
VOC contamination in groundwater at the FOSET #2 Group 2 Action Sites is addressed under the VOC
Groundwater ROD that was completed in 2007 (AFRPA, 2007). VOC contamination in the vadose zone
that threatens groundwater is also addressed under the VOC Groundwater ROD (AFRPA, 2007). Non-
VOCs that may be present in groundwater at the FOSET #2 Group 2 Action Sites are addressed in the Non-
VOC ROD Amendment (AFRPA, 2009). Deed restrictions specified in the VOC Groundwater ROD and
included in the FOSET #2 restrict the use of groundwater, protect the integrity of the groundwater remedial
systems at the FOSET #2 Group 2 Action Sites, and provide for access to the wells.
Contamination addressed by this ROD is located within the upper 15 feet bgs of soil and includes sites
within OUs A, G, and H.
2.4.1 Past Removals/Interim Actions
The Air Force has previously undertaken some removal actions to clean up the FOSET #2 Group 2 Action
Sites and reduce the risks to people and the environment.
Various USTs have been removed from 16 of the FOSET #2 Group 2 Action Sites (AOC 325, CS S-021,
CS T-037, CS T-059, PRL P-003, PRL S-022 & SA 069, PRL T-015, PRL T-019, PRL T-031, SA 038, SA
048, SA 059, SA 078, SA 079 and SA 086). The status of these UST removals is listed in Attachment B.
It should be noted that closure has only been granted by the Central Valley Water Board for UST removals
at seven of these 16 sites. The remaining USTs will be administratively closed by the Central Valley Water
Board.
The FOSET #2 Group 2 Action Sites are within the radius of influence of 11 SVE systems (Investigation
Cluster [IC] 23, IC 25, IC 27, IC 29, IC 30, IC 31, IC 32, IC 34, IC 35, IC 37, and PRL T-044) that were
installed by the Air Force under past CERCLA removal actions to address the potential threat to
groundwater from VOCs (CH2MHill 2011 2012). For SVE system details, see Attachment B.
2.5 SITE CHARACTERISTICS
The Air Force conducted multi-year investigations to characterize the contamination and develop remedial
alternatives for the FOSET #2 Group 2 Action Sites. Site-specific characterizations are detailed in the
Small Volume Sites RICS Addenda and FS (CH2MHill, 2011), the Follow-on Strategic Sites RICS and FS
(CH2MHill, 2012), the Small Volume Sites FS Addendum (EPA, 2016b), and the Follow-on Strategic Sites
FS Addendum (EPA, 2016c). EPA, DTSC, and the Central Valley Water Board concurred on these
findings.
Individual site characteristic summaries of the FOSET #2 Group 2 Action Sites addressed in the ROD are
presented in Table 2-1 and Attachment D. This table and attachment present information to support the
selection of remedial alternatives, including the site features that impacted remedy selection; sources or
potential sources of contamination, a summary of the SSG and soil risks, selected remedial alternative(s),
and the target excavation volumes. Generally, contamination sources at the FOSET #2 Group 2 Action
Sites are related to the routine Air Force activities, aviation support operations, vehicle and facility
maintenance activities, accidental spills and releases, and onsite storage or disposal of hazardous materials.
Remedial alternatives were selected primarily based on the SSG and soil risks and for protection of water
quality at each site.
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Table 2-1 Site Characteristics
Silo
Silc IViiluivs
Soiircc/I'olenliid Sources
of ('oiKiiiniiiiilion
Shallow Soil (l;is
Soil3
Selected Remedial
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AOC 325
This site consists of the 0.3-acre area between Building 1033
and former Building 1036, which was formerly used as a
hazardous waste storage area, and a small portion of Building
1033. A portion of the IWL (PRL L-001) runs through AOC
325 from east to west. There are two USTs associated with
former Building 1036: 1036A - 4,000 gallon diesel UST, and
1036B - 2,000 gallon aviation fuel tank removed in 1996. A
bioventing system was installed by the Air Force in January
2010 to address TPH contamination at AOC 325. The USTs
and bioventing system were granted closure by the Central
Valley Water Board on August 8, 2016. A bermed storage
area (concrete pad) is located in the northeastern side of the
site, where former Building 1036 was located. A second
bermed area, located in the northwestern corner of AOC 325,
may have supported a hazardous waste storage area.
Surface spills from hazardous
waste storage areas at Building
1033 (engine testing and
motor/generator repairs) and
former Building 1036 (fuel
storage), or from a washrack
east of former Building 1036
may have released
contaminants to surface soil.
Additionally, contaminants may
have been released to
subsurface soil as a result of
exfiltration from the IWL and
USTs.
SSG risk is within the risk management range for
both unrestricted and restricted uses. The HI is
greater than 1 for unrestricted use and less than 1
for the restricted use. The SSG COCs are
chloroform, naphthalene, TCE and PCE.
Soil risk is at the high end of the risk management
range for unrestricted use and at the low end of the
risk management range for restricted use. The HI
is greater than 1 for unrestricted use and less than
1 for the restricted use. Arsenic is a driver for risk
and hazard. However, arsenic concentrations are
within the range of background for subsurface
soils; therefore, arsenic was not identified as a
COC. Excluding arsenic, the soil risk is at the low
end of the risk management range for the
unrestricted use scenario. The soil COCs are
benzo(a)pyrene, TPH-D, and TPH-G.
VOC3 (ICs/ECs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
CS P-005
This site is the location of former 600-foot unlined drainage
ditch that conveyed surface water runoff from Buildings 473
and 475 (reciprocating aircraft engine repair and test area) to
Magpie Creek from 1943 to the early 1990s. In the early
1990s, the ditch was rerouted to the west, and all but the
southern end of site was filled with soil. Currently, all but the
extreme southern portion of the site is covered by Building
445 or asphalt. From October 1999 to May 2008, the southern
half of the site was under the influence of the IC 35 SVE
system.
Runoff from former engine
repair and the test area flowed
into storm drains that emptied
into the site, and then flowed
north into Magpie Creek.
Risk is within the risk management range for
unrestricted use, and at the low end of the risk
management range for restricted use. The HI for
unrestricted use is greater than 1 and for restricted
use, less than 1. There is some uncertainty
regarding SSG, because SSG samples were only
collected at two locations (CSP5SBB004 and
CSP5SBB007), the latter being northeast of the
site boundaries. The SSG COCs are naphthalene,
PCE, 1,3,5-TMB, and 1,2,4-TMB.
Soil risk is at the upper end of the risk
management range for unrestricted use and within
the risk management range for restricted use. The
HI is greater than 1 for unrestricted use and less
than 1 for restricted use. Arsenic is a driver for risk
and hazard, but was determined to be within the
range of naturally occurring background
concentrations. Excluding arsenic, soil risks are
within the low end of the risk management range
for unrestricted use. Cobalt was detected at a
concentration exceeding the unrestricted use
screening level and slightly exceeding the range of
concentrations in the background data set, but was
subsequently determined to be isolated and not a
source of contamination. PCBs concentrations in
surface soil (0.078 mg/kg) exceed the cleanup
level for protection of human health.
There are potential impacts to surface water
quality from dieldrin and dioxins/furans.
The soil COCs are PCBs, dieldrin, and
dioxins/furans.
VOC2 (ICs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
CS P-006
This site is a drainage ditch that accepts run-off from several
source areas. The drainage ditch was previously unlined and
1150 feet long, but the northern portion was widened and
lined with concrete in 1980. The southern portion was
backfilled in the late 1940s and Building 431 was constructed
over part of the former ditch, leaving about 260 feet of
remaining drainage ditch. The ditch receives stormwater,
which overflows into Magpie Creek when it reaches a certain
level. The site was formerly under the influence of the IC 35
SVE system, which operated from June 1999 until May 2008.
The site may have been
impacted by runoff from fire-
training activities at adjacent
site CS T-057 and nearby
industrial areas that drain to
lined portion of drainage ditch.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and is less than 1 for the
industrial use. The SSG COCs are benzene;
chloroform; cis-l,2-DCE; 1,2-DCA;
ethylbenzene; naphthalene; PCE; TCE; 1,2,4-
TMB; 1,3,5-TMB, and vinyl chloride.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and is less than 1 for the
industrial use. However, the dioxins/furans
contamination is addressed with overlapping
source sites CS T-057, SA 080, SA 107, and PRL
L-003A-B.
There are potential impacts to groundwater quality
from arsenic; however, the arsenic exceedances
VOC3 (ICs/ECs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Sile l-'e:ilures
Soiircc/I'olenliid Sources
of ('oiKiiiniiiiilion
Shallow Soil (l;is
Soil3
Selected Remedial
Allern:ili\e(s)b
T:ir»cl
\ 01 u in ec
were detected using Method SW6010, which is
considered to be an unreliable method for arsenic.
There are potential impacts to surface water
quality from TPH-D, dioxins/furans, and chrysene.
The soil COCs are cadmium, chrysene,
dioxins/furans, and TPH-D.
CS S-021
This site consists of 31,000-square foot Building 351, which
contained an ordnance shop, a paint shop, and a cleaning
shop. The building was also used for degreasing, machining,
and blasting operations. In the 1950s, Building 351 housed a
hydraulic repair shop, an electrical equipment repair shop,
and a small-toll repair shop. Materials handled in Building
351 included solvents, VOCs, SVOCs, acids, bases, fuels,
oils, and paint. The building originally had six floor drains
that flowed to the IWL. As of 1997, five of the drains had
been grouted, capped, or covered over. A former solvent UST
was located in the southeast corner of Building 351 and was
removed in 1989. The UST has not been granted closure
status. A degreaser was located in the northwest corner of
Building 351. CS S-021 was formerly under the influence of
the IC 29 and IC 31 SVE systems.
Leaks from a former solvent
UST, a degreaser, and releases
from IWL drains located within
Building 351 may have
impacted the subsurface soil.
Spills or leaks from the
degreaser may have impacted
the surface soil. Additionally,
contamination from nearby
sites SA 102 (washrack),
leaking sections of the IWL
(PRL L-002D), and CS T-017
(tank farm) has affected soil gas
and groundwater.
Risk is at the upper end of the risk management
range for unrestricted use and within the risk
management range for industrial use. The HI is
less than 1 for both unrestricted use and industrial
use. The SSG COCs are ethylbenzene; carbon
tetrachloride; chloroform; 1,4-DCB; TCE; and
PCE.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is less
than 1 for both unrestricted use and industrial use.
Excluding arsenic, the soil risk is on the low end
of the risk management range for unrestricted use
and below the risk management range for
industrial use. No soil COCs have been identified.
There are potential impacts to groundwater quality
from arsenic, but concentrations are within the
range of natural background. No potential impact
to surface water quality is indicated.
VOC3 (ICs/ECs)
N/A
CS S-027
This site consists of a former solvent supply and recovery
system that included a 10,000-gallon solvent AST, an OWS, a
piping trench, and a solvent distillation unit located in
Building 478. CS S-027, which is about 1000 square feet, was
at least partially paved during site operations. All site features
associated with the solvent supply and recovery unit and
Building 478 were demolished in 1994. Most of CS S-027 is
now covered by gravel, with some pavement present in the
southern portion of the site. The OWS has not been granted
closure status. CS S-027 was within the radius of influence of
two IC 37 SVE wells
Spills from operations at the
solvent supply and recovery
unit, the AST, and the OWS
may have impacted the surface
soil. Leaks from the piping
trench, sump, and drain may
have impacted the subsurface
soil.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is 14 for
unrestricted use and less than 1 for industrial use.
Although risk for industrial use is within the risk
management range, there are multiple VOCs
detected at concentrations exceeding industrial
screening levels and ECs are needed to mitigate
SSG risk for industrial users. The SSG COCs are
naphthalene; 1,4-DCB; 1,2,4-TMB; 1,3,5-TMB;
TCE; and PCE.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is less
than 1 for both unrestricted use and industrial use.
Arsenic is the main driver of soil risk, but
concentrations in soil are within the range of
background. Excluding arsenic, soil risks are at the
low end of the risk management range for
unrestricted use and below the risk management
range for industrial use. No soil COCs have been
identified.
There are potential impacts to groundwater quality
from arsenic; however, arsenic concentrations in
soil are within the range of natural background.
While concentrations of TPH-D and TPH-G
exceed screening levels, concentrations are
shallow and do not exceed the protection of
groundwater quality levels. No surface soil
samples were collected at this site
VOC3 (ICs/ECs)
N/A
CS T-037
This 50-square foot site is the former location of a 500-gallon
Stoddard solvent UST contained within an open-top and
open-bottomed concrete vault. In 1989, the vault was
reportedly and intentionally filled with water above the level
of the tank, and product from the tank was observed floating
on the water. When inspected in 1989, it was observed that a
"homemade" 130-gallon tank had been mounted on the top of
the UST. No information is available about when the
homemade tank was installed or what it was used for. The
Releases resulting from leaks in
UST and associated piping may
have impacted the subsurface
soil.
Risk is at the upper end of the risk management
range for unrestricted use and at the lower end of
the risk management range for industrial use. The
HI is less than 1 for both unrestricted use and
industrial use. Although risk for industrial use is
within the risk management range, there are
multiple VOCs detected at concentrations
exceeding industrial screening levels and ECs are
needed to mitigate SSG risk for industrial users.
Risk is at the upper end of the risk management
range for unrestricted use and at the lower end of
the risk management range for industrial use. The
HI is greater than 1 for unrestricted use and less
than 1 for industrial use. Arsenic and cobalt are the
main drivers of soil risk, but concentrations of
both metals are within the range of natural
background concentrations and the maximum
detected concentrations are less than the
VOC3 (ICs/ECs)
N/A
28
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Sile l-'e:ilures
Soiircc/I'olenliiil Sources
of ('oiKiiiniiiiilion
Shallow Soil (l;is
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tank, the concrete vault, and 2 feet of soil from beneath the
concrete pads were removed in 1989 and backfilled with
clean soil. The UST has not been granted closure status.
Currently, CS T-037 is paved, and the surrounding area is
covered in asphalt. CS T-037 was within the former radius of
influence of the IC 31 and IC 29 SVE systems.
The SSG COCs are carbon tetrachloride,
chloroform, 1,4-DCB, ethylbenzene, PCE, and
TCE.
background values. Aluminum is also within the
range of natural background concentrations.
Excluding arsenic, the soil risk is below the risk
management range. Excluding arsenic, aluminum,
and cobalt, the soil HI is less than 1. No soil COCs
have been identified.
CS T-059
This site is the former location of a 4,000-gallon UST (circa
1962-1987) that provided fuel for a nearby service station.
The UST was removed in 1987 and the site was reportedly
backfilled with clean soil. Closure was granted for the UST
by the Central Valley Water Board in September 2000. Prior
to installation of the UST, a small southern portion of the site
overlapped an area used for vehicle parking and storage.
Releases resulting from leaks in
UST and associated piping may
have impacted the subsurface
soil.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is
equal to 1 for unrestricted use and less than 1 for
industrial use. However, there is uncertainty
regarding SSG because only a single SSG sample
was collected for this site. The SSG COC is
naphthalene.
Risk is below the risk management range for both
unrestricted use and industrial use. The HI is less
than 1 for both unrestricted use and industrial use.
No soil COCs have been identified.
Soil data do not indicate potential impacts to
surface water or groundwater quality.
VOC2 (ICs)
N/A
PRL L-001
(F2)
This site is the location of an underground IWL that
transports wastewater generated from numerous industrial
facilities to the IWTP. A short segment of the IWL line was
within the former radius of influence of the SVE system at
PRL T-044.
PRL L-001 includes the portions of the IWL within OUs F
and G and the northern portion of OU H. PRL L-001 (F2)
extends into OU H approximately 400 feet south of Lift
Station 1000 to the west-east length of Price Avenue. The
remainder of PRL L-001 in OU H was included in FOSET #1
and will be included with the PRL L-001 A/B (Fl) remedy
with the FOSET #1 Group 4 sites. It should be noted that the
short segment in OU G between Manholes 36A and Sump
1048, which was included in FOSET #1 (Parcel A4, Lot 23,
near PRL T-044) will be included with the PRL T-044
remedy with the FOSET #1 Group 4 sites.
Potential IWL leaks as a result
of deteriorated pipes and/or
offset joints, lift stations,
manholes, and sumps may have
released contaminants to the
subsurface soil.
Risk is at the upper end of the risk management
range for unrestricted use and at the low end of
the risk management range for industrial use. The
HI is greater than 1 for unrestricted use and less
than 1 for industrial use. Although risk for
industrial use is within the risk management
range, there is uncertainty because the full length
of the IWL has not been characterized. The SSG
COCs are 1,2,4-TMB; benzene; chloroform;
chloromethane; methylene chloride; naphthalene;
PCE; TCE; and vinyl chloride.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and is less than 1 for industrial
use. PCBs concentrations in surface soil (0.0862
mg/kg) exceed the cleanup level for protection of
human health. There are potential impacts to
groundwater quality from arsenic; however,
arsenic concentrations are either within the range
of natural background or were measured using
Method 6010, which is unreliable for arsenic.
There are potential impacts to surface water
quality from arsenic, lead, PAHs (chrysene,
benzo(a)anthracene, benzo(a)pyrene,
benzo(b)fluoranthene, benzo(k)fluoranthene,
dibenzo(a,h)anthracene, indeno( 1,2,3 -c,d)pyrene),
lead, TPH-G, and PCBs.
The CSM for PRL L-001 does not support surface
or near surface releases, so nearby site activities
(including aircraft maintenance and fuel/solvent
storage) are most likely the source of shallow soil
contamination along this portion of the IWL;
however, each site should have a remedy to
address the contamination within the site
boundaries.
VOC3 (ICs/ECs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
PRL L-002
This site is the location of an underground IWL (PRL L-
002A-D) consisting of four segments (A-D) located
throughout IC 23, IC 29, IC 30, and IC 31 in OU A. The
IWL is situated at depths ranging from 5 to 13 feet bgs and
was used to collect wastewater from buildings in this portion
of McClellan for treatment at an IWTP. The majority of PRL
L-002A-D was within the radius of influence of former SVE
systems (IC 23, IC 29, IC 30, and IC 31).
Leaks from the IWL as a result
of deteriorated pipes or offset
joints may have impacted the
subsurface soil.
Risk is above the risk management range for both
unrestricted use and industrial use. The HI is
greater than 1 for both unrestricted use and
industrial use. The SSG COCs are benzene;
carbon tetrachloride; chloroform; cis-l,2-DCE;
ethylbenzene; naphthalene; 1,2,4-TMB; 1,3,5-
TMB; xylenes; PCE; and TCE.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and is less than 1 for industrial
use. Benzo(a)pyrene concentrations (1.04 mg/kg)
exceed the cleanup level for protection of human
health. There are potential impacts to groundwater
quality from arsenic; however, arsenic
concentrations are either within the range of
natural background or were measured using
VOC3 (ICs/ECs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
29
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Sile l-'e:ilures
Soiircc/I'olenliid Sources
of ('oiKiiiniiiiilion
Shallow Soil (l;is
Soil3
Selected Remedial
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Method 6010, which is unreliable for arsenic.
There are potential impacts to surface water
quality from arsenic and lead.
The CSM for PRL L-002 does not support surface
or near surface releases, so nearby site activities
(associated with sites such as CS S-024, PRL S-
017, and SA 102) are most likely the source of
shallow soil contamination along this portion of
the IWL; however, each site should have a remedy
to address the contamination within the site
boundaries. The soil COCs are cadmium, lead,
benzo(a)pyrene, and TPH-G.
PRL L-003
(F2)
This site is an underground IWL located in the west-central
portion of OU A in the southeastern area of the former
McClellan AFB, which is a main conduit of the IWL piping
system that transports industrial wastewater from five
facilities (Buildings 443, 447, and 651, Tank Farm 1, and a
washrack located in IC 35 and IC 36). The IWL is below
ground at depths ranging from about 3 to 15 feet bgs and was
in operation from the 1940s until the late 1990s. Most of PRL
L-003B (the eastern portion of PRL L-003) was within the
former radius of influence of the SVE system at IC 35. The
length of the IWL north of Manhole 431J is located in Parcel
Big, Lot 219, of FOSET #3; the remedy fortius portion of
the IWL was selected in the Follow-On Strategic Sites ROD.
Leaks from the IWL as a result
of deteriorated pipes or offset
joints may have impacted the
subsurface soil.
Risk is at the upper end of the risk management
range for unrestricted use and at the lower end of
the risk management range for industrial use. The
HI is equal to 1 for unrestricted use and is less
than 1 for industrial use. Although risk for
industrial use is within the risk management
range, there is uncertainty associated with
characterizing the entire length of the IWL. The
SSG COCs are benzene, carbon tetrachloride,
chloroform, naphthalene, PCE, and TCE.
Risk is at the upper end of the risk management
range for unrestricted use and within the risk
management range for industrial use. The HI is
greater than 1 for unrestricted use and is less than
1 for industrial use. Arsenic and aluminum are the
main drivers of soil hazard, but concentrations of
both are within the range of natural background.
Excluding arsenic and aluminum, soil risks are
within the risk management range and the HI is
less than 1 for both unrestricted and industrial use;
however, cadmium was detected at concentrations
up to 10 mg/kg while the risk assessment only
considered a concentration of 0.96 mg/kg. The
concentration of 10 mg/kg exceeds the cleanup
level and adds approximately 1.5 to the HI. The
soil COCs are cadmium, benzo(a)pyrene,
benzo(a)anthracene, benzo(b)fluoranthene,
benzo(k)fluoranthene, indeno(l,2,3-c,d)pyrene,
and chrysene.
There are potential impacts to groundwater quality
from arsenic; however, arsenic is within the range
of natural background. There are potential impacts
to surface water quality from chrysene.
VOC3 (ICs/ECs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
PRL L-004
This site is the location of the underground IWL (PRL L-
004A-B). Wastewater from both lines A and B drained by
gravity to Lift Station D, which is located near former
Building 473A. Wastewater from Lift Station D then flowed
by gravity through the IWL system westward to the IWTP.
The majority of PRL L-004A is within the radius of influence
of the former IC 34 and IC 37 SVE systems. Only the
northern portion of PRL L-004B (north and east of SA 060)
was within the radius of influence of the IC 37 SVE system.
Leaks from the IWL as a result
of deteriorated pipes or offset
joints may have impacted the
subsurface soil.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for both unrestricted use and industrial use. The
SSG COCs are benzene; 1,3-butadiene; carbon
tetrachloride; chloroform; 1,4-DCB;
ethylbenzene; hexane; hexachlorobutadiene;
naphthalene; PCE; TCE; 1,1,2,2-PCA; 1,2,4-
TMB; 1,3,5-TMB; and vinyl chloride.
Risk is at the upper end of the risk management
range for unrestricted use and within the risk
management range for industrial use. The HI is
greater than 1 for unrestricted use and is less than
1 for industrial use. Arsenic and cadmium are the
main drivers of soil risk, but isolated elevated
concentrations of both metals do not appear
indicative of contamination from Air Force
activities. Soil risks (without arsenic and
cadmium) are below the unrestricted risk
management range. The soil COCs are cadmium,
lead, TPH-D, and TPH-G.
VOC3 (ICs/ECs)
Non-VOC4a
(Excavation and
Disposal-Restricted
Land Use)
6,210 cy
30
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Sile l-'e:ilures
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of ('oiKiiiniiiiilion
Shallow Soil (l;is
Soil3
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There are potential impacts to groundwater quality
from arsenic (using non-SW6010 methods),
thallium, TPH-D, and TPH-G. Thallium
concentrations are considered within the range of
background.
There are potential impacts to surface water
quality from arsenic, cadmium, and lead. There are
also potential impacts to surface water quality
from aluminum, but concentrations of aluminum
were within the range of background levels.
PRL L-005
(F2)
This site is the location of an underground IWL (PRL L-
005G), that received wastewater from eight facilities. The
IWL consists of 2900 feet of piping consisting predominantly
of 15- to 18-inch vitrified clay pipe and buried at depth
between 11 and 19 feet bgs. The FOSET #2 portion of PRL
L-005G is approximately 2,000 feet long and includes the
section of IWL between Manhole 16 and just east of Manhole
19, plus the branch to Building 651. This segment of IWL
runs east-west and connected the eastern portion of Former
McClellan AFB with the western portion and the IWTP. The
IWL operated from 1940 to 1994 and transported materials
including fuels, oils, paints, cyanide, acids, bases, metals, and
radionuclides.
Leaks from the IWL as a result
of deteriorated pipes or offset
joints may have impacted the
subsurface soil.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and is less than 1 for
industrial use. Although risk for industrial use is
within the risk management range, there is
uncertainty related to characterizing the length of
the entire IWL. The SSG COCs are benzene,
chloroform, 1,2-DCA, 1,4-DCB, ethylbenzene, 2-
methylnaphthalene, 1,2,4-TMB, 1,3,5-TMB,
naphthalene, PCE, and TCE.
Risk is at the upper end of the risk management
range for unrestricted use and at the low end of the
risk management range for industrial use. The HI
is greater than 1 for unrestricted use and is less
than 1 for industrial use. Arsenic is the main driver
of soil risk, but soil concentrations are within the
range of background. Excluding arsenic, soil risks
are below the unrestricted risk management range.
No soil COCs have been identified.
There are potential impacts to groundwater quality
from arsenic. Arsenic concentrations are within the
range of background.
VOC3 (ICs/ECs)
N/A
PRLP-001
This site comprises a former engine test cell, revetment area,
and drainage ditch. Currently, Building 877 (former
administrative office and aircraft maintenance hangar), a
parking lot, a grassy area, and streets are present in this area.
A diesel-powered backup generator and associated 250-gallon
diesel AST were located at this site. Activities such as
cleaning, maintenance, and testing of reciprocating engines
took place at two portable test stands. Building 877 is
currently used by the California Department of Forestry and
Fire Protection for maintaining aircraft.
Potential releases may have
resulted from historical surface
disposal practices, surface
spills, and leaks.
Risk is within the risk management range for
unrestricted use and below the risk management
range for industrial use. The HI is less than 1 for
both unrestricted use and industrial use. No SSG
COCs have been identified.
Risk is at the lower end of the risk management
range for unrestricted use and below the risk
management range for industrial use. The HI is
equal to 1 for unrestricted use and is less than 1 for
industrial use. The soil COCs are PCBs.
There are potential impacts to groundwater quality
from arsenic. There are potential impacts to
surface water quality from PCBs.
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
PRL P-003
This site is the location of a former oil fill pit where mop carts
were placed beneath aircraft to collect the oil and hydraulic
fluid drained from the aircraft. PRL P-003 is also the location
of a former 150-gallon diesel UST, which was removed in
1990. There are no records indicating the location of the tank
or whether it was given closure status. PRL P-003 was within
the radius of influence of the IC 29 SVE system.
Possible leaks from the fill pit,
and from the nearby UST and
associated piping pose the
potential subsurface impacts.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is less
than 1 for both unrestricted use and industrial use.
Two older SSG sample locations are located
approximately 15 and 60 feet outside of the PRL
P-003 site boundaries (the other soil gas samples
were collected deeper than 15 feet bgs). Based on
the original sampling, SSG COCs identified in
SSG are benzene, naphthalene, and TCE.
In 2017, an interim SSG data gap investigation
was completed to verify the CSM and supporting
information within the Site boundaries and
included the collection of two SSG samples at 7
feet bgs. Chloroform, cis-l,2-DCE, PCE, and
TCE were detected in the 2017 samples, but no
No soil COPCs have been identified at PRL P-003.
Thus, no carcinogenic risks or non-carcinogenic
hazards for soil exposures were calculated. Arsenic
(detected by Method SW6020) was the only
analyte detected in soil that exceeded screening
levels, but was below background.
VOC2 (ICs)
N/A
31
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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VOCs were detected at concentrations above the
IC compliance levels. Therefore, no additional
SSG COCs were identified.
PRL P-004
This site consists of Lift Station F, two manholes, and a
multiple line junction of the IWL. This site received
wastewater from Buildings 351, 362, 363, and 375, as well as
facilities upstream of these locations. Lift Station F consists
of a sump that operated from approximately 1955 to 1991.
PRL P-004 was within the radius of influence of the former
IC 31 SVE system.
Leaks from the IWL as a result
of deteriorated pipes or offset
joints may have impacted the
subsurface soil.
Risk is within the risk management range for
unrestricted use and below the risk management
range for industrial use. The HI is less than 1 for
both unrestricted use and industrial use. There is
uncertainty regarding initial SSG
characterization; although eight SSG samples
were collected at four locations, all of these
locations are located outside of the site
boundaries. Prior to 2017, there were no SSG
samples collected within the boundaries of this
site, where several IWL lines come together.
Based on the original data, the SSG COCs are
chloroform and TCE.
In 2017, an interim SSG data gap investigation
was completed to verily the CSM and supporting
information within the Site boundaries and
included the collection of two SSG samples at 7
feetbgs. Benzene, chloroform, cis-l,2-DCE, 1,1-
DCA, ethylbenzene, PCE, TCE, 1,3,5-TMB, and
vinyl chloride were detected in the 2017 samples,
and the chloroform concentration in one sample
(PP04-SG-01-7.0) was above the IC compliance
level. Based on the previous data and the 2017
sampling, the COCs identified in SSG are
chloroform and TCE.
Risk is within the risk management range for
unrestricted use and for industrial use. The HI is
less than 1 for both unrestricted use and industrial
use. Only arsenic and cobalt were detected in soil
at concentrations greater than any screening levels;
however, they are not considered to represent a
source of contamination. Arsenic is the risk driver
but was detected at a concentration less than
background.
Soil data do not indicate potential impacts to
groundwater. No surface soil samples have been
collected at this site, but since PRL P-004 is a
multiple line junction of the IWL, surface soil
contamination is not consistent with the CSM.
VOC3 (ICs/ECs)
N/A
PRL S-022
& SA 069
PRL S-022 consists of Building 355 while SA 069 consists of
Building 367. Building 355 has housed a number of
operations since its construction. In the 1940s and 1950s, the
northern portion of Building 355 contained the carpentry
shop, the southern portion contained the welding shop, and
the southern wing contained the battery shop. In the 1960s,
the main section of Building 355 was converted to hydraulic
and pneumatic repair shops. During this time, there were
hydraulic and solvent spray booths located in the southern
wing of the building. An aboveground bulk solvent tank was
located adjacent to the southern wall of Building 355, east of
the former fuel USTs. There was a chemical degreaser located
on the western side of Building 355, which was used to clean
various pieces of equipment being repaired in the hydraulic
and pneumatic shops. In 1983, the hydraulic and pneumatic
repair shops moved out of Building 355 and the building was
converted to office space. The southern wing remained the
battery repair shop. Approximately 80 batteries a month were
serviced at the battery shop. This service included draining
and refilling, which produced approximately 100 to 150
gallons of waste sulfuric acid per month. The waste sulfuric
Leaks from IWL drains and
lines, a sump, abandoned fuel
oil USTs, former diesel USTs
and associated lines, or the oil
and boiler water runoff sump
and chemical mixing tanks may
have impacted the subsurface
soil and spills, leakage, and/or
runoff from the solvent AST,
transformer, fuel pumps,
solvent spray booths, hydraulic
spray booth, and chemical
degreaser at this site may have
impacted the surface soil.
Risk is above the risk management range for
unrestricted use and wihin the risk management
range for industrial use. The HI is less than 1 for
both unrestricted use and industrial use. There is
uncertainty about SSG concentrations
surrounding PLS22SB013. There is also
uncertainty regarding SSG characterization other
than the extent surrounding sample location
PLS22SB013; although SSG samples were
collected at seven locations, only two of these
locations are within the site boundaries. The SSG
COCs are PCE; TCE; 1,1,2,2,-PCA; benzene;
carbon tetrachloride; and chloroform.
Risk is at the upper end of the risk management
range for unrestricted use and within the risk
management range for industrial use. The HI is
equal to 1 for unrestricted use and is less than 1 for
industrial use. Several PAHs are present at
concentrations above the cleanup levels and have
been identified as COCs. The soil COCs are
benzo(a)anthracene, benzo(a)pyrene,
benzo(f)fluoranthene, chrysene, naphthalene, and
TPH-D.
There are potential impacts to groundwater quality
from TPH-D and arsenic and to surface water
quality from arsenic. Arsenic exceedances were
detected using Method SW6010, which is
considered unreliable for this metal. Detections of
arsenic using the more reliable Method SW7060
are all below background.
VOC3 (ICs/ECs)
Non-VOC4a
(Excavation and
Disposal-Restricted
Land Use)
1,940 cy
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
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of ('oiKiiiniiiiilion
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acid was poured into 55 gallon drums that were periodically
transferred to 15-gallon containers and transferred to the
plating shop (exact building on base is unknown). Building
355 was vacated in 2001. A transformer location with oily
staining on the concrete surrounding the transformer was
noted on the western side of Building 355.
Building 367 contained a steam-generation facility.
Chemical-mixing tanks, on the southern side of Building 367,
were used to soften water upstream from the boilers. An IWL
drain and sump adjacent to the chemical tank area were used
to drain excess fluid from the chemical mixing tanks, which
had been removed from the site. An oil/water runoff sump
was used to collect oil/water discharges from the boilers. A
transformer is located at the northwestern corner of Building
367. The entire site is covered by asphalt or concrete, and it is
unlikely that any leaks or spills associated with a potentially
leaking transformer migrated to the soils below the concrete
or asphalt.
Several former USTs located between PRL S-022 and SA 069
supplied fuel to the boilers used for steam production in
Building 367. There were two 21,000-gallon fuel oil USTs
and two 20,000-gallon diesel fuel storage USTs. The 21,000-
gallon tanks (367A and 367D) were constructed of concrete
and used to store fuel oil; these tanks were abandoned in
place in 1991 and 1995. Two 20,000-gallon USTs (367B and
367C) were constructed of steel and were used to store diesel
fuel. In 1996, tanks 367B and 367C (the steel diesel USTs)
were removed and replaced with tanks 367E and 367F. Tanks
367E and 367F were 20,000-gallon tanks that were also used
to stored diesel fuel. Use of the diesel tanks 367E and 367F
was discontinued in 1998, when the boilers were converted to
operate using natural gas. Tanks 367E and 367F were
removed in July 2003, along with the associated piping
connecting them to Building 367. The USTs at PRL S-022
and SA 069 have not been granted closure status. The site
was formerly under the influence of the IC 29 SVE system.
PRL S-037
This site is the 1.5 acre location of former outdoor drum
storage area. The eastern portion is covered by asphalt and the
western portion by concrete. The asphalt was reportedly
cracked from weathering. A shallow unlined drainage ditch is
located to the south; surface runoff from PRL S-037 flows
south to the unlined drainage ditch and eventually into Arcade
Creek.
Releases resulting from leaks
and/or spills from historically
stored drums containing
solvents, oils, and automotive
waste fluids may have impacted
surface soil.
Risk is within the risk management range for
unrestricted use and at the lower end of the risk
management range for industrial use. The HI is
less than 1 for both unrestricted use and industrial
use. Although risk for unrestricted use is within
the risk management range, there are multiple
VOCs detected at concentrations exceeding
residential screening levels and ICs are needed to
prevent unrestricted use. The SSG COCs are 1,3-
butadiene, benzene, carbon tetrachloride, PCE,
and 1,1,2,2-PCA.
Metals were detected at concentrations consistent
with background levels. No soil COPCs have been
identified. Thus, no carcinogenic risks or non-
carcinogenic hazards for soil exposures were
calculated.
VOC2 (ICs)
N/A
33
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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PRL T-015
This site is the location of former Tank Farm #1 (nine 50,000-
gallon fuel USTs) and two buildings (448 and 449) that
served as fill stands. Buildings 448 and 449 were constructed
in 1955. Prior to the construction of these buildings, PRL T-
015 was used intermittently for storage. The USTs were also
installed in 1955 and removed in 1997 along with associated
piping. It is unknown if the fill used in the excavation was
tested. The USTs have not been granted closure status. The
surface of the site is covered with a mixture of gravel and
vegetation. The site was under the former influence of the IC
35 SVE system.
Spills from the fill stands may
have impacted the surface soil,
and releases from leaks in
USTs and piping may have
impacted subsurface soil.
Risk is at the lower end of the risk management
range for unrestricted use and below the risk
management range for industrial use. The HI is
greater than 1 for unrestricted use and is less than
1 for industrial use. The SSG COCs are benzene,
ethylbenzene, naphthalene, PCE, TCE, 1,2,4-
TMB, and 1,3,5-TMB.
Risk is below the risk management range for both
unrestricted and industrial use. The HI is greater
than 1 for unrestricted use and is less than 1 for
industrial use. Excluding thallium, soil risks are
below the risk management range for both
scenarios. Although they are not risk drivers,
concentrations of benzo(a)anthracene,
benzo(a)pyrene, benzo(b)fluoranthene,
benzo(k)fluoranthene, and naphthalene in soil
exceed the soil cleanup levels in Table 2-3.
There are impacts to surface water quality from
PCBs. The soil COCs are PCBs, PAHs, and
naphthalene.
VOC2 (ICs)
Non-VOC4a
(Excavation and
Disposal-Restricted
Land Use)
60 cy
PRL T-019
This 18,000-square foot site is the location of the former UST
farm known as Tank Farm No. 5. The UST farm consisted of
a fuel filling stand, loading area, and three 12,000-gallon
USTs. The USTs were installed in 1946 and used for storing
aviation fuel and waste aviation fuel. The tanks and filling
equipment were removed in 1960, and the tank excavation
was filled with clean soil. The exact location of the fuel
filling stand and loading area is unknown. The tanks have not
been given closure status because of contamination detected
during previous investigations. PRL T-019 was within the
former radius of influence of the IC 32 SVE system.
Releases during filling
activities may have impacted
the surface soil, and releases
from the USTs may have
impacted the subsurface.
Risk is at the lower end of the risk management
range for unrestricted use and below the risk
management range for industrial use. The HI is
less than 1 for both unrestricted use and industrial
use. No SSG COCs have been identified.
Risk is below the risk management range for both
unrestricted and industrial use. The HI is greater
than 1 for unrestricted use and is less than 1 for
industrial use. Thallium is the main driver of soil
risk, but elevated thallium detections are most
likely the result of an unreliable analytical method
(Method SW6010); however, the HI is greater than
1. Therefore thallium is identified as a COC. The
soil COC is thallium.
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
PRL T-031
This site originally consisted of Buildings 1027 and 1028,
both of which were constructed in 1957 and used primarily
for aircraft maintenance. Beginning in 1994, the buildings
stored office furniture, administrative supplies, and military
supplies and equipment of the 940th Division. Currently,
Building 1027 is vacant and Building 1028 houses the
aerospace museum. At least two USTs supported these
buildings' operations (UST 1028Aand 1028B). USTs 1028A
and 1028B were removed in 1989, and an unknown amount
of soil was excavated. Both USTs received closure
designations by the Central Valley Water Board in July 1999.
Buildings 1032 and 1033 are outside the site boundary, but
they were included with the site in order to investigate
additional hangars in an area that was not previously included
within an IRP site. These buildings also supported aircraft
maintenance activities.
Releases from USTs or from
light maintenance activities to
floor drains and the IWL may
have impacted subsurface soil.
Releases from transformers
along Price Avenue may have
impacted the surface soil.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and less than 1 for industrial
use. The SSG COCs are benzene, naphthalene,
chloroform, PCE, and TCE.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and less than 1 for industrial
use. The soil COCs are manganese and vanadium.
There are potential impacts to surface water
quality from PCBs; however, the reported
concentrations do not exceed the protection of
surface water PCG (0.025 mg/kg).
VOC3 (ICs/ECs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
34
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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Selected Remedial
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PRL T-033
This site consists of Buildings 1020 and 1021 (aircraft
maintenance hangars) and a former aircraft wash area.
Building 1022 (aircraft maintenance hangar) was also
investigated as part of the site, although it is outside the site
boundary. During the early 1990s, the hangar buildings were
extended and the former aircraft wash area was completely
covered. A segment of the IWL (PRL L-001A) runs through
the eastern portion of PRL T-033. Surface features at PRL T-
033 include Buildings 1020 and 1021 and anunpaved grassy
area between the buildings. The northeastern portion of PRL
T-033 was under the former influence of the PRL T-044 SVE
system.
Releases from light
maintenance activities to floor
drains and the IWL may have
impacted the subsurface soil.
Spills and leaks near the aircraft
wash area and from
transformers located adjacent to
Price Avenue east of Building
1021 may have impacted the
surface soil.
Risk is at the upper end of the risk management
range for unrestricted use and within the risk
management range for industrial use. The HI is
greater than 1 for unrestricted use and less than 1
for industrial use. However, the TCE results at
boring PT3 3 SB005 (under Building 1021) were
2030 ppbv at 5 feet bgs and 516 ppbv at 15 feet
bgs, which raises concerns regarding exposure for
current and future occupants at Building 1021.
The SSG COCs are 1,2,4-TMB, benzene,
chloroform, chloromethane, naphthalene, PCE,
TCE, and vinyl chloride.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and less than 1 for industrial
use. Lead concentrations (229 mg/kg) exceed the
cleanup level for protection of human health. The
soil COCs are Aroclor-1254, Aroclor-1260, cobalt,
cadmium, lead, benzo(a)anthracene,
benzo(a)pyrene, benzo(b)fluoranthene, chrysene,
dibenzo(a,h)anthracene, and indeno(l,2,3-
c,d)pyrene.
Soil data indicate potential impacts to groundwater
quality from arsenic, but arsenic is within the
range of background. There are potential impacts
to surface water quality from cadmium, lead,
PAHs (benzo(a)anthracene, benzo(a)pyrene,
benzo(b)fluoranthene, chrysene,
dibenzo(a,h)anthracene, indeno( 1,2,3 -c,d)pyrene),
and PCBs.
VOC3 (ICs/ECs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
SA 037
This 8,500-square foot site consists of Building 24 (a motor
pool) and the location of a former small storage shed to the
northwest of the building. The former motor pool operated
from 1939 until 1972. The storage she was removed in 1971.
Since 1972, Building 24 has been used for administrative
offices. A new addition, approximately 60 feet by 40 feet,
was added to the south end of Building 24 around 1992.
Automotive fluids, including fuels, oils, and solvents
(generated from degreasing activities), were stored and
handled at Building 24 and the shed, and mineral oil
contaminated with PCBs was also handled at the site. The
site was within the former influence of the IC 25 SVE system.
Spills from motor pool
operations and possible leaks or
spills from storage shed may
have impacted surface soil.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is less
than 1 for both unrestricted use and industrial use.
Although risk for unrestricted use is within the
risk management range, there are multiple VOCs
detected at concentrations exceeding residential
screening levels and ICs are needed to prevent
unrestricted use. The SSG COCs are chloroform
and PCE.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is
greater than 1 for unrestricted use and less than 1
for industrial use. Aluminum, thallium, and arsenic
are the primary contributors to the soil risk;
however, aluminum and arsenic concentrations are
within the range of natural background, and
thallium was detected with an unreliable method
(Method SW6010). Excluding aluminum,
thallium, and arsenic, soil risks are below the
unrestricted risk management range. No soil COCs
have been identified.
There are potential impacts to groundwater and
surface water quality from arsenic, but the data
indicate that the detected concentrations are below
background levels.
VOC2 (ICs)
N/A
SA 038
This 5,000-square foot site consists of Building 26, which
served as gas station from 1940 to about 1990, and two
former USTs. From 1940 to 1980, two 5,000-gallonUSTs
stored gasohol and leaded gasoline. In 1980, these USTs were
removed and replaced with a 5,000-gallon diesel UST and a
10,000-gallon unleaded gasoline UST. These two USTs and
associated piping were removed in 1990. The pipelines were
reportedly 4 inches in diameter and 3.5 inches long. The
USTs were over-excavated to 13 feet bgs and backfilled with
clean soil. The USTs have not been granted closure. Building
26 was most recently used as a locksmith shop, but is not
currently occupied. In 1997, abioventing system was
installed to remediate TPH contamination. The bioventing
Leaks from the USTs and
associated piping may have
impacted the subsurface soil,
and spills from fuel pumps may
have impacted the surface soil.
Risk is within the risk management range for
unrestricted use and below the risk management
range for industrial use. The HI is less than 1 for
both unrestricted use and industrial use. However,
the risks are based on a single sample location,
and there is some uncertainty regarding SSG
concentrations to the north. The SSG COCs are
benzene and chloroform.
No soil COPCs were identified at SA 038 in the
human health risk assessment. Thus, no
carcinogenic risks or non-carcinogenic hazards for
soil exposures have been calculated.
There are potential impacts to groundwater quality
from arsenic, TPH-D, and TPH-G; however, the
arsenic concentrations were detected using Method
SW6010, which is considered to be an unreliable
method for arsenic. Although there are no soil
COCs that pose a human health risk, TPH-D and
TPH-G exceed groundwater protection preliminary
cleanup goals, and data indicate that natural
VOC2 (ICs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
35
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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system was recommended for shutdown and has been inactive
since September 2003. The southern portion of SA 038 was
within the former radius of influence of the IC 25 SVE
system.
degradation of TPH is still occurring. TPH-D and
TPH-G are identified as soil COCs.
SA 040
This 35,000-square foot site includes a former electrical
repair shop and civil engineering storage area for construction
materials and chemicals. Buildings 49, 50, 53, 56, and 58
were all located within SA 040, and the remainder of the site
is paved. Materials handled at these buildings include acids,
gas cylinders, batteries, and solvents. The electrical repair
shop was located on the eastern side of Building 53 (exterior)
and began operation in 1967. Drums and electrical
maintenance equipment were stored in a "lean-to" structure
built directly on the asphalt. Building 58 is the only building
that still exists onsite. All other buildings have been removed
and the site is completely covered in asphalt or by concrete
foundations (Building 53), and is currently divided by a
fence. Materials typically stored included, paint, oil,
chemicals, and other miscellaneous construction items. A
gasoline spill was reported to have occurred in March 1993 at
the former location of Building 53. The specific location and
amount of gasoline released is unknown. SA 040 was
partially within the former radius of influence of the IC 25
SVE system.
Activities associated with
repairs and maintenance and
hazardous materials and/or
waste storage may have
impacted surface and/or
subsurface soil.
Risk is at the lower end of the risk management
range for unrestricted use and below the risk
management range for industrial use. The HI is
less than 1 for both unrestricted use and industrial
use. No SSG COCs have been identified based on
the older data. Prior to 2017 only two SSG
samples were collected from a single location
(SA40SB001) at this 35,000-square foot site.
In 2017, an interim SSG data gap investigation
was completed to verily the CSM and supporting
information within the Site boundaries and
included the collection of two SSG samples at 7
feet bgs. Carbon tetrachloride, chloroform, PCE,
and TCE were detected in the two 2017 samples,
but no VOCs were detected at concentrations
above the IC compliance levels. No additional
SSG COCs were identified. Uncertainty remains
regarding SSG characterization because three
SSG sample locations are not sufficient to
characterize the 35,000-square foot site.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and less than 1 for industrial
use.
There are potential impacts to surface water from
cadmium, lead, and TPH-D, but SA 040 is
completely paved by asphalt or covered by former
building foundations. ECs are needed to maintain
the pavement and a soil management plan is
needed to address diesel in shallow soil.
Cadmium, cobalt, lead, and TPH-D are identified
as soil COCs.
An interim soil investigation for arsenic was
completed in 2017 that included the collection of
two samples (one surface soil and one subsurface
soil) from two locations. Arsenic was detected in
all four samples, but all detections were below
background. Therefore, arsenic was not identified
as a soil COC.
VOC2 (ICs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
SA 043
This 2.91 acre site is the former location of Building 236 and
four storage sheds, and the current location of Building 239
(aircraft maintenance hangar). A concrete-asphalt-paved area
surrounds Building 239 and extends approximately 410 feet
south of the building. The site includes sumps, a drainage
trench, and a hazardous waste storage area. Building 239
contained a sump, a drain, and an approximately 180-foot
drainage trench. The trench is not connected to the IWL or to
the sanitary sewer. The final discharge location of the
drainage is most likely an outdoor sump located about 150
feet southwest of Building 239. Waste solvent was poured
into a 3 3-gallon hazardous storage container that was serviced
by a contractor. A transformer is located at the southwest
corner of Building 239. All four storage sheds were
demolished and removed by 1988, and no information
concerning their contents or function is available. No
information about the use of former Building 236 is available.
In 2002, the drain trench in Building 239 was abandoned-in-
place by grouting with concrete.
Activities associated with
aircraft maintenance, hazardous
materials and/or waste storage,
possible leaks in waste oil/fuel
bowser, and discharges/leaks
from outdoor sumps may have
impacted surface and/or
subsurface soil.
Risk is within the risk management range for
unrestricted use and at the lower end of the risk
management range for industrial use. The HI is
less than 1 for both unrestricted use and industrial
use. Although risk for both unrestricted and
industrial use is within the risk management
range, SSG samples were collected from only six
locations, which is not sufficient to characterize
such a large site (2.91 acres). The SSG COCs are
naphthalene, methylene chloride, and PCE.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is
greater than 1 for unrestricted use and less than 1
for industrial use. The soil COCs are cadmium,
cobalt, and zinc.
There are potential impacts to groundwater quality
from arsenic; however, arsenic concentrations are
within the range of natural background. Soil data
do not indicate potential impacts to surface water;
however, only one surface soil sample was
collected.
VOC2 (ICs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
36
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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Silc l-'e:ilures
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SA 044
This site consists of Building 240, which supported a former
aircraft nose dock from 1957 to 1973 and an x-ray facility for
aircraft components from 1973 until at least 1990. X-ray film
developing and silver recovery were performed inside
Building 240. A 300-gallon sump on the north side of the
building was used to collect filtered wastewater from these
operations. Wastewater was later pumped into a 1,000-gallon
bowser (mobile fuel tanker) that was emptied weekly at the
on-base Industrial Waste Treatment Plant. Hazardous
materials used or stored at the site included aircraft fuels,
hydraulic fluids, metals, acids, bases, solvents, oils, grease,
and waste absorbent. Abandoned fuel distribution lines
associated with the adjacent SA 108 are located east of
Building 240.
Activities associated with film
developing, spills or leaks of
hazardous materials, and
discharges/leaks from tanks and
sumps may have impacted
surface and/or subsurface soil.
There is insufficient SSG data available for the
site. The 1996 samples were analyzed using
T014, but a sample was only collected at 21.3 ft
(no SSG samples were collected from within 15
feet bgs) and the 1999 samples were analyzed
using M18MS. Risk values are not available (they
were not calculated because no VOCs were
detected in the samples collected, but detection
limits were elevated). TCE was identified as a
SSG COC.
In 2017, an interim SSG data gap investigation
was completed to verify the CSM and supporting
information within the Site boundaries and
included the collection of two SSG samples at 7
feet bgs. Benzene, carbon tetrachloride,
chloroform, cis-l,2-DCE, 1,1-DCA,
ethylbenzene, PCE, and TCE were detected in the
two 2017 samples, and the TCE concentration in
one sample (SA44-SG-01-7.0) and its duplicate
was above the IC compliance level. These results
confirm the identification of TCE as a SSG COC.
Risk is below the risk management range for both
unrestricted use and industrial use. The HI is
greater than 1 for unrestricted use and less than 1
for industrial use. Results for thallium were
flagged by the laboratory as "estimated" amounts
and do not increase in concentration with depth,
indicating the concentrations of thallium in soil are
representative of natural variation in background
levels. The thallium concentration was detected
with Method SW6010, which is considered to be
unreliable at the reported concentrations.
An interim soil investigation for arsenic and
thallium was completed in 2017 that included the
collection of two samples (one surface soil and one
subsurface soil) using method SW6020. Arsenic
and thallium were detected in both samples, but all
arsenic detections were below background and all
thallium detections were below cleanup levels.
Therefore, arsenic and thallium were not identified
as soil COCs.
VOC3 (ICs/ECs)
N/A
SA 047
This 7,600-square foot site consists of two former washracks
housed inside Buildings 254 and 257 and a hazardous
materials storage area. The washrack in Building 254 was
built circa 1940 and was demolished in 1986. The washrack
in Building 257 was built in 1986 near the east side of
Building 251 and the former location of the washrack in
Building 254. At each washrack, wastewater flowed into
drains, which were reportedly connected to the IWL. This site
also included a 1,000-gallon bowser tank used for storage of
waste motor and hydraulic oil. SA 047 was within the radius
of the influence of EW-326 and EW-367 from the IC 23 SVE
system.
Releases from washracks, spills
or leaks of hazardous materials,
and discharges/leaks from tanks
may have impacted surface
and/or subsurface soil.
Risk is within the risk management range for
unrestricted use and below the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and less than 1 for industrial
use. There is uncertainty regarding SSG
characterization. Although three SSG samples
were collected at two locations, only one of these
samples was collected within the site boundaries.
The SSG COCs are chloroform, naphthalene, and
PCE.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and less than 1 for industrial
use. Arsenic was not detected greater than
background in the sample analyzed by Method
SW7060. Excluding arsenic, soil risk is less than
the risk management range for both unrestricted
and industrial use; however, the HI is still greater
than 1 due to cadmium and cobalt. Lead
concentrations (150 mg/kg) exceed the cleanup
level for protection of human health.
Soil data do not indicate potential impacts to
groundwater quality. There are potential impacts
to surface water quality from arsenic, cadmium,
and lead. The soil COCs are cadmium, cobalt, and
lead.
VOC2 (ICs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
SA 048
This 20,000-square foot site consists of Building 264 (which
was used for storage of building and ground maintenance
materials) and a former 375-gallon diesel UST that was used
as backup fuel source for the generator on the west side of the
building. In 1996, UST 264 was granted closure status by the
Central Valley Water Board. SA 048 was partially within the
former radius of influence of the IC 25 SVE system. Small
quantities of solvents, paints, stains, resins, and glues were
stored in hazmat cabinets along the south wall of Building
264.
Releases from spills or leaks of
hazardous materials, and
discharges/leaks from tanks
may have impacted surface
and/or subsurface soil.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is less
than 1 for both unrestricted use and industrial use.
Although risk for both unrestricted and industrial
use is within the risk management range, SSG
samples were collected from only three locations,
which is not sufficient to characterize such a large
site (20,000 square feet). The SSG COCs are
chloroform and naphthalene.
Risk is below the risk management range for both
unrestricted use and industrial use. The HI is less
than 1 for both unrestricted use and industrial use.
No soil COCs have been identified.
Soil data do not indicate potential impacts to
groundwater or surface water quality.
VOC2 (ICs)
N/A
37
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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SA 053
This approximately 0.83 acre site is the location of Building
310, which contained an equipment repair area and special
vehicle maintenance facility, a hazardous waste staging area,
a washrack, a storage shed, and a bowser tank. The washrack
was used to wash maintenance equipment, and the wash
water was collected in a centrally located drain. It is unknown
if the drain connected to the IWL or the sanitary sewer.
Petroleum-based wastes were stored in a 750-gallon bowser
tank that was emptied every 4 to 6 months. According to Base
personnel, the bowser tank was in a gravel area east of
Building 310; however, the exact location of the tank is
unknown. A discolored area is in the southern portion of the
site where waste oil may have been stored. SA 053 was
within the former radius of influence of the IC 27 SVE
system.
Leaks from the storage shed
and bowser tank, and
subsurface leaks from the
washrack area and associated
piping may have impacted the
surface and subsurface soil.
Risk is at the upper end of the risk management
range for unrestricted use and within the risk
management range for industrial use. The HI is
less than 1 for both unrestricted use and industrial
use. However, no SSG samples were collected
beneath the washrack or the hazardous waste
storage area, which results in some uncertainty
with regard to SSG characterization. The SSG
COCs are benzene, carbon tetrachloride,
chloroform, PCE, TCE, hexachlorobutadiene, and
naphthalene.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is
greater than 1 for unrestricted use and less than 1
for industrial use. Arsenic and thallium are the risk
drivers in soil at SA 053, but arsenic was detected
below background and both metals were detected
using an unreliable method (SW6010). When
arsenic and thallium are excluded, soil risks are
below the unrestricted risk management range. No
soil COCs have been identified.
There are potential impacts to groundwater quality
from arsenic and thallium and to surface water
quality from arsenic, but data for these metals
were obtained with Method SW6010 and are
considered unreliable.
VOC3 (ICs/ECs)
N/A
SA 058
This 17,500-square foot site consists of former Building 334
(wet chemistry, x-ray diffraction, and radiological
laboratories), which was built sometime between 1938 and
1942. The building included floor drains connected to the
sanitary sewer lines and a suspected AST at the southern end
of the building. Spent laboratory samples, including acids,
bases, and small quantities of chloroform, were disposed of
into the sanitary sewer system. A transformer was located
outside the southwest corner of Building 334. Building 334
was demolished in 1993, and only the foundation remains. SA
058 was partially under the influence of the IC 27 SVE
system.
Releases from disposal or spills
of material used in labs and
leaks from a suspected AST
and transformer may have
impacted the surface soil. Leaks
from a sanitary sewer may have
impacted the subsurface soil.
Risk is greater than the risk management range
for unrestricted use and at the upper end of the
risk management range for industrial use. The HI
is greater than 1 for unrestricted use and less than
1 for industrial use. Although the risk for
industrial use is within the risk management
range, it is at the very upper end and ECs are
needed to mitigate SSG for industrial users. The
SSG COCs are benzene, chloroform, carbon
tetrachloride, naphthalene, and PCE.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is less
than 1 for both unrestricted use and industrial use.
Arsenic is the main driver of soil risk, but soil
concentrations are within the range of natural
background. Excluding arsenic, soil risks are
below the risk management range for unrestricted
use. No soil COCs have been identified.
There are potential impacts to groundwater quality
from arsenic, but arsenic data are below
background. There are potential impacts to surface
water quality from PCBs. However, the reported
concentrations do not exceed the protection of
surface water PCG (0.025 mg/kg).
VOC3 (ICs/ECs)
N/A
SA 059
This 9,000-square foot site consists of Building 338 (which
contained classrooms, offices, and a 500-gallon diesel UST)
and former Building 91 (Base Well 8, which consisted of a
3,000-gallon AST, 500-gallon AST, 200-gallon gasoline
UST, and a sump). A railroad spur ran along the east side of
Building 338. The Spur was removed prior to 1971, and the
entire area is currently covered with asphalt. The USTs were
removed in 1988 and received closure from the Central
Valley Water Board in 1995. An area of discolored soil had
been identified in aerial photographs between the railroad
tracks; it is no longer present. SA 059 was partially within the
former radius of influence of the IC 27 SVE system.
Leaks/spills from tanks and
activities associated with the
railroad spurs may have
impacted surface and/or
subsurface soil.
Risk is at the lower end of the risk management
range for unrestricted use and below the risk
management range for industrial use. The HI is
less than 1 for both unrestricted use and industrial
use. Although the risk for unrestricted use is
within the risk management range, there is
uncertainty remaining because SSG samples were
only collected from two locations in the southern
portion of SA 059. The SSG COCs are
hexachlorobutadiene, benzene, and naphthalene.
Risk is at the lower end of the risk management
range for unrestricted use and below the risk
management range for industrial use. The HI is
equal to 1 for unrestricted use and less than 1 for
industrial use. The soil COCs identified in soil are
benzo(a)anthracene, benzo(a)pyrene,
benzo(b)fluoranthene, and chrysene.
There are potential impacts to groundwater from
arsenic. There are potential impacts to surface
water from arsenic, TPH-D, and chrysene. Arsenic
was detected using Method SW6010, which is
considered unreliable for this metal. ECs are
needed to maintain surface cover due to PAHs.
VOC2 (ICs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
SA 067
This site consists of the 73,000-square foot Building 360
(used for F-15 and A-10 aircraft maintenance) and the area
south of the building, which was used for hazardous waste
storage. Areas west of the building include a former wash
rack, a former 400-gallon hydraulic fluid AST, a former
Releases from the washrack,
leaks/spills from the tanks, and
activities associated with
aircraft maintenance may have
Risk is at the lower end of the risk management
range for unrestricted use and below the risk
management range for industrial use. The HI is
less than 1 for both unrestricted use and industrial
use. However, there is uncertainty regarding SSG
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is
greater than 1 for unrestricted use and less than 1
for industrial use. Arsenic was detected using
Method SW7060 in one sample, but this
VOC3 (ICs/ECs)
N/A
38
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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1,000-gallon steel bowser tank, and a hazardous materials
storage area. A catch basin/vault on the southern end of the
washrack collected runoff. The catch basin/vault was located
in 1985 and was determined to be abandoned, but its exact
location was never documented and is currently unknown.
The washrack was located on badly cracked concrete and
asphalt and was used to clean and remove paint from aircraft.
The AST was located in a bermed area that had repeatedly
filled up with hydraulic fluid over the last 25 years; and that
light solvents and heavy detergents were used to remove paint
and to wash down aircraft in the former washrack area west
of Building 360. The removal date of the AST is unknown
and the bowser tank was reported to have been removed
following the environmental baseline survey in 1999. The
washrack room in the southeastern corner of Building 360
was used to steam clean aircraft parts. A sump collected wash
water from the steam cleaning activities performed in the
southeastern washrack room. The sump discharged wash
water into the IWL system. Operations inside Building 360
ceased in April 1999. SA 067 was within the former radius of
influence of the IC 29 SVE system.
impacted surface and/or
subsurface soil.
characterization. This site is about 147,650 square
feet (approx. 3.39 acres) with a 73,000-square
foot building that was used for aircraft
maintenance, but no SSG samples were collected
beneath the building and only five SSG sample
locations were located within the site boundaries.
The SSG COCs are benzene, chloroform,
ethylbenzene, naphthalene, PCE, and TCE.
concentration is below background. Cobalt was
detected above the unrestricted use screening level
in one sample. No soil COCs have been
identified.
SA 068
This approximately 0.90 acre site consists of Building 365
(aircraft hangar), where aircraft maintenance and minor paint
stripping activities took place dating back to 1943. TCE was
known to be sprayed on parts and left to air-dry. TCE spills
on the floor were not uncommon. A hydraulic manifold
system was present in the building and consisted of hydraulic
fluid lines that ran beneath the building. A hazardous material
storage area used to store paint was located in the north end
of the building, and 5 5-gallon waste drums (potentially
containing Freon or hydraulic oil) were stored in the
southwest portion of the building. Two additional hazardous
materials storage areas were located along the west edge of
the building where chemicals for maintenance activities and
waste from building activities were stored. Trench drains ran
along each side of the hangar. Cracks in the concrete
foundation were noted throughout the building, and an
employee noted that a floor drain in the west-central portion
of the building occasionally backed up and overflowed. SA
068 was partially within the radius of influence of the former
IC 29 SVE system.
Activities associated with
aircraft maintenance and paint
stripping, leaks of hazardous
materials, and releases from
trench drains may have
impacted surface and/or
subsurface soil.
Risk is at the lower end of the risk management
range for unrestricted use and below the risk
management range for industrial use. The HI is
less than 1 for both unrestricted use and industrial
use. However, there is uncertainty regarding SSG
characterization, because only two SSG samples
were collected from a single location
(PT10SB017). Benzene, carbon tetrachloride,
chloroform, 1,4-DCB, ethylbenzene, naphthalene,
PCE, and TCE were identified as SSG COCs.
In 2017, an interim SSG data gap investigation
was completed to verify the CSM and supporting
information within the Site boundaries and
included the collection of three SSG samples at 7
feetbgs. Chloroform, cis-l,2-DCE, 1,4-DCB,
PCE, and TCE were detected, but no VOCs were
detected at concentrations above the IC
compliance levels. Therefore, no additional SSG
COCs were identified.
Risk is below the risk management range for both
unrestricted use and industrial use. The HI is
greater than 1 for unrestricted use and less than 1
for industrial use. Cobalt was detected above the
unrestricted use screening level in one sample;
however, it was not detected above screening
levels in deeper samples from the same location,
indicating that the detection is isolated and does
not represent a source of contamination.
There are potential impacts to groundwater quality
from arsenic, but data were obtained with Method
SW6010 and are considered unreliable at the
reported concentrations. Arsenic results by a more
reliable method (Method SW7060) indicate
concentrations were below background levels. Soil
data do not indicate potential impacts to surface
water quality.
An interim soil investigation for arsenic was
completed in 2017 that included the collection of
two samples (one surface soil and one subsurface
soil). Arsenic was detected in both samples, but
all arsenic detections were below background.
Therefore, arsenic was not identified as soil a
COC.
VOC2 (ICs)
N/A
39
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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SA 071
This 1,400-square foot site includes Building 369, which is
the former location of hazardous material (southern part of
building) and hazardous waste (northern part of building)
storage areas that were used from 1969 until base closure in
2001. An open area to along the west side of the building was
used as a staging area for hazardous waste from the
reprographics department. An area southwest of the building
was used to containerize 55-gallon drums on pallets.
Additionally, two transformers are located on the west side of
the building. Hazardous materials stored at the site included
paints, oils, thinners, and film-developing chemicals.
Hazardous wastes stored along the side of the building
included solvents, spent containers, paints, solvent-
contaminated rags, and chemicals found in printing and photo
developing labs.
Releases from spills and leaks
of hazardous materials from the
storage and staging areas, and
possible surface releases from
the transformers.
Risk is within the risk management range for
unrestricted use and below the risk management
range for industrial use. The HI is less than 1 for
both unrestricted use and industrial use. Although
the risk for unrestricted use is within the risk
management range, there is uncertainty remaining
because SSG samples were only collected from a
single location. The SSG COCs are benzene and
chloroform.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and less than 1 for industrial
use. Arsenic was detected at concentrations above
background using Method SW6010, which is
considered unreliable for this metal. Excluding
arsenic, soil risks are less than the risk
management range for unrestricted use; however,
the soil HI for unrestricted use is still greater than
1 due to cadmium.
There are potential impacts to groundwater and
surface water quality from arsenic, but arsenic data
were obtained with Method SW6010 and are
considered unreliable. There are potential impacts
to surface water quality from PCBs, arsenic, and
cadmium. ECs are needed to maintain the surface
cover because of PCBs and cadmium.
VOC2 (ICs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
SA 073
This site is approximately 0.32 acres and consists of former
Building 385 (comprised of a hangar, observation room,
heating and cooling equipment room, and a basement
containing hydraulic equipment) and the surrounding area.
Before Building 385 was constructed in 1970, this area was
used to wash aircraft. Operations in Building 385 ceased in
1999. Approximately 300 gallons of hydraulic fluid was used
to operate stress rams. A sump that discharged to Magpie
Creek was reportedly located in the basement and collected
spills that may have occurred. A 25,000-gallon liquid
nitrogen AST was located at the southwest side of the
building. Current site conditions are dirt and grass, some
concrete and remaining curbing, and a concrete pad with
electrical switching station.
Spills from the hydraulic
equipment and aircraft washing
activities subsurface releases
from the sump at Building 385.
There is insufficient SSG data available. The soil
gas sample from 21-21.5 feet bgs at SA73HP31
contained high levels of VOCs, but there were no
SSG samples collected at the site prior to 2017.
Risk values are not available (none were
calculated because SSG samples were not
collected). No SSG COCs have been identified.
In 2017 an interim SSG data gap investigation
was completed to verify the CSM and to provide
supporting information within the Site boundaries
and included the collection of two SSG samples
at 7 feet bgs. Chloroform and TCE were
detected, but no VOCs were detected at
concentrations above the IC compliance levels.
Therefore, no SSG COCs were identified.
No soil samples were collected prior to 2017, so
the risk associated with soil is uncertain and it is
unknown if contaminants with potential impacts to
groundwater and surface water quality are present.
An interim soil investigation was completed in
2017 that included the collection of three surface
soil and two subsurface soil samples from three
locations. Several metals and PAHs were
detected, but only lead and benzo(a)pyrene
concentrations exceeded cleanup levels. The
reporting limit for PCBs was greater than the
cleanup level. Therefore, benzo(a)pyrene, lead,
and PCBs have been identified as soil COCs.
VOC2 (ICs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
SA 077
This approximately 0.58 acre site consists of Building 411,
which was used for aircraft and automotive maintenance. In
1965, two 500-gallon oil ASTs were installed at the north
corner of Building 411 and were used until 1990. The site
also included a hazardous material staging and storage area
and three self-contained solvent/degreasing sinks. Site
drawings show a capped IWL drain and three sanitary drains.
SA 077 was within the former radius of influence of the IC 37
SVE system.
Spills from hazardous material
staging and storage area may
have impacted surface soil.
Releases from the
solvent/degreasing sinks, IWL
drain, USTs at CS T-020, or
fuel distribution pipeline may
have impacted the subsurface
soil.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is less
than 1 for both unrestricted use and industrial use.
However, there is some uncertainty regarding this
risk characterization due to the past SVE system
operation. The SSG COCs are benzene, carbon
tetrachloride, chloroform, PCE, 1,2,4-TMB,
ethylbenzene, and naphthalene.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is less
than 1 for both unrestricted use and industrial use.
No soil COCs have been identified.
There are potential impacts to groundwater from
TPH-D and to surface water quality from TPH-D
and PCBs.
VOC2 (ICs)
N/A
40
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Site Features
Source/Potential Sources
of Contamination
Shallow Soil Gas
Soil3
Selected Remedial
Alternative(s)b
Target
Volume0
SA 078
This site is approximately 0.66 acres and consists of Building
412, a former locomotive maintenance facility that operated
from 1946 to 1994. This area consisted of a hazardous
materials storage building and locomotive washing area, a
service pit for working on locomotives, and a 3,100 gallon
UST that was removed in November 1985. IWL drains were
located in the washing area, and a hazardous material shed
was located adjacent to the washing area. . Closure for the
UST was granted by the Central Valley Water Board in
September 1999. From 1988 to 1994, the concrete service pit
collected water, which was pumped to the IWL. Before 1988,
wastewater was pumped into a 1,000-gallon bowser tank.
Materials used, handled, and stored at SA 078 include fuels,
oils, solvents, and acids. Wastes were containerized and
picked up by Defense Reutilization Marketing Office for
proper disposal. There was evidence of spills in the stained
benn area southwest of Building 412. Building 412 is
currently used as a locomotive maintenance facility by
Sacramento Valley Railroad.
Surface spills or leaks from
operation of the locomotive
maintenance facility, former
1,000-gallon bowser tank,
former locomotive wash area,
and former hazardous materials
storage building. Subsurface
leaks from the former 3,100-
gallon diesel UST and Building
412 service pit with associated
sump and drain lines.
Risk is at the lower end of the risk management
range for unrestricted use and below the risk
management range for industrial use. The HI is
less than 1 for both unrestricted use and industrial
use. No SSG COCs have been identified.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is less
than 1 for both unrestricted use and industrial use.
There are potential impacts to groundwater from
arsenic; however, arsenic data exceeding
background values were detected using Method
SW6010, which is considered unreliable for
arsenic. Arsenic data analyzed using Method
SW7060 are below the background value for
arsenic. There are potential impacts to surface
water quality from arsenic, lead, and TPH-D. The
soil COCs are lead and TPH-D.
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
SA 079
This site is approximately 0.50 acres and consists of Building
429 (former fuel-testing facility and electronics and motor
shop), which was constructed in 1951. Building 429 operated
as an electronics and motor shop from 1964 to 1985. Stoddard
solvent was reportedly used to degrease parts at the
electronics shop. Building 429 had 4 solvent trench pipelines
and 18 IWL floor drains. The IWL runs along the
southwestern corner of the building. Four fuel and lubricant
USTs ranging from 265 gallons to 10,000 gallons were in the
southeast corner of the building. These USTs were installed
in the 1950s and removed prior to April 1989. The USTs have
not been granted closure. SA 079 was within the former
radius of influence of the IC 35 SVE system.
Releases from USTs, solvent
supply line, solvent drain line
trenches, and IWL drains inside
the building may have impacted
the subsurface soil.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for both unrestricted use and industrial use. The
SSG COCs are chloroform, 1,4-DCB,
ethylbenzene, hexachlorobutadiene, naphthalene,
PCE, TCE, 1,2,4-TMB, 1,3,5-TMB, and vinyl
chloride.
Risk is at the upper end of the risk management
range for unrestricted use and within the risk
management range for industrial use. The HI is
greater than 1 for unrestricted use and less than 1
for industrial use. Arsenic is the main driver of soil
risk, but was analyzed using an unreliable method.
Excluding arsenic, soil risks are below the risk
management range for unrestricted use and
industrial use, but the HI for unrestricted use is
above 1. The soil COC is cadmium.
There are potential impacts to groundwater quality
from arsenic and thallium, but the data for these
metals were obtained with Method SW6010 and
are considered unreliable.
VOC3 (ICs/ECs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
SA 081
This site consists of a fuel distribution pipeline constructed of
3-, 4- and 6-inch-diameter black iron pipe. The pipeline was
constructed to convey aviation gas, jet fuel, and lube oil from
former Tank Farms 1, 2, 3, 6, and 8 to various buildings
throughout OU A. The fuel pipeline began operations in 1956
and operated until 1992. Approximately one-quarter of the
pipeline is located in an underground, concrete-lined trench.
The remaining sections of the pipeline are buried
underground. Following the end of operations, the various
sections were drained, steam cleaned, and then abandoned in
place.
Leaks from the fuel distribution
pipeline as result of
deteriorated pipes and offset
joints may have impacted the
subsurface soil.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is
greater than 1 for unrestricted use and less than 1
for industrial use. The SSG COCs are TCE; PCE;
benzene; chloroform; ethylbenzene; naphthalene;
vinyl chloride; 1,2,4-TMB; and 1,3,5-TMB.
Risk is at the upper end of the risk management
range for unrestricted use and within the risk
management range for industrial use. The HI is
greater than 1 for unrestricted use and less than 1
for industrial use. Arsenic is the main driver of the
soil risk at SA 081, but it is not a COC for fuel
pipelines, and it was within the range of natural
background. Excluding arsenic, soil risks are
within the risk management range for unrestricted
use and at the low end of the risk management
range for industrial use. Lead concentrations (173
mg/kg and 575 mg/kg) exceed the cleanup level
for protection of human health. Concentrations of
benzo(a)anthracene, benzo(a)pyrene.
VOC3 (ICs/ECs)
Non-VOC4a
(Excavation and
Disposal-Restricted
Land Use)
42,620 cy
41
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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benzo(b)fluoranthene, and chrysene also exceed
cleanup levels.
There are potential impacts to surface water
quality from cadmium, lead, and TPH-D and to
groundwater quality from TPH-D, TPH-G, arsenic,
and thallium, but arsenic was detected below
background levels and thallium was detected using
a method that is considered unreliable.
The soil COCs are benzo(a)anthracene,
benzo(a)pyrene, benzo(b)fluoranthene, cadmium,
chrysene, lead, naphthalene, 2-methylnaphthalene,
TPH-D, and TPH-G.
SA 086
This approximately 0.25 acre site consists of former Building
458 (demolished), four former 1,000-gallon single-wall steel
USTs (removed in 1989), and an oil sump in the building's
basement (removed during building demolition). Building
458 is a former engine testing facility (from 1940 to 1972),
with a radioactive instrumentation calibration-repair
laboratory (from the early 1960s to the late 1970s) and a dry-
cleaning facility (from 1990 to the early 2000s). A portion of
the IWL runs west of Building 458. An IWL sump was off
the north corner of the building and received wastewater from
operations at Building 458. Wastewater from building
operations discharged to the sump (oil/water separator with a
sump) in the basement. The sump was connected to the IWL.
According to the 1997 physical site survey, there were two
floor drains in the basement; however, the exact locations
cannot be determined because the building has been
demolished. The four USTs contained waste oil to support jet
engine testing operations at Building 458. One of the USTs
(Tank 458C) had a significant hole on one side. During the
removal of the USTs, contaminated soil was excavated, and
the site was backfilled with clean soil and covered with
concrete. Closure was granted for the four USTs by the
Central Valley Water Board in 1996.
Releases from the USTs, the oil
sump, and IWL may have
impacted the subsurface soil,
and releases from activities in
building may have impacted the
surface.
Risk is within the risk management range for
unrestricted use and below the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and less than 1 for industrial
use. Although the risk for unrestricted use is
within the risk management range, there is
uncertainty remaining because SSG samples were
only collected from two locations in the southern
portion of SA 086. The SSG COCs are PCE,
benzene, 1,2,4-TMB, and 1,3,5-TMB.
Risk is below the risk management range for both
unrestricted use and industrial use. The HI is
greater than 1 for unrestricted use and less than 1
for industrial use. Cadmium was detected at an
elevated concentration in two of fifteen samples.
The soil COCs are cadmium, lead, and TPH-D.
There are potential impacts to groundwater quality
from arsenic, but most arsenic data were obtained
with Method SW6010 and are considered
unreliable. Arsenic results from samples analyzed
using Method SW7060 were below background.
There are potential impacts to groundwater quality
from TPH-D. There are potential impacts to
surface water quality from cadmium and lead.
VOC2 (ICs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
SA 094
This 2.4 acre site is the location of a former fuel metering
station, fuel pipeline, hazardous waste/material storage area,
former motor oil storage shed, and fuel truck parking and
maintenance area. The fuel metering station was in the
southeastern corner of SA 094 and operated from 1946 to
1964. The fuel lines in this area carried jet fuel from the
Southern Pacific railroad to the metering station. The fuel
meters were capped and decommissioned in 1979, and this
area now consists of an empty asphalt lot. The fuel truck
parking and maintenance area began operations in 1964. It is
unknown when these operations ended. The fuel truck
parking and maintenance area contained an asphalt-covered,
bermed hazardous waste/material storage area along the
western boundary of SA 094. The hazardous materials storage
Releases from spills within the
fuel metering station, hazardous
waste/material handling, spills
from the suspected motor oil
storage shed, and truck leaks
may have impacted the surface
soil. Leaking fuel pipelines may
have impacted the subsurface
soil.
Risk is within the risk management range for
unrestricted and industrial use. The HI is less than
1 for both unrestricted use and industrial use. It
should be noted that the extent of naphthalene in
SSG is uncertain. The SSG COCs are benzene
and naphthalene.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is less
than 1 for both unrestricted use and industrial use.
Arsenic is the main driver of soil risk, but it was
detected below background levels.
There are potential impacts to groundwater quality
from arsenic, but arsenic was detected below
background using Method SW7060. There are
potential impacts to surface water quality from
chrysene and TPH-D. The soil COC is chrysene.
VOC2 (ICs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
42
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Silc l-'e:ilures
Soiircc/I'olenliiil Sources
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Selected kcmcdiiil
Allern:ili\e(s)b
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\ Ol u in ec
area was decommissioned and capped with asphalt and
concrete prior to 1979. The southern portion of SA 094 was
within the former radius of influence of the IC 35 SVE
system.
SA 098
This 20,000-square foot site consists of Building 271, where
electronic repair, electrical testing, a spray paint booth, and a
solvent spray booth rooms were located. The building was
constructed in 1943. The floor consists of concrete, and no
floor drains have been identified. The spray paint and solvent
spray booths operated until 1985. From 1985 to 1991,
building materials were stored at the site. The northern part of
the building is currently occupied by Sun Edison, and the
southern part is occupied by Silver State Helicopters Flight
Academy. Building 271 is surrounded by asphalt and
concrete.
Releases from disposal or spills
of materials used in the solvent
and spray paint booths may
have impacted the surface soil.
Risk is within the risk management range for
unrestricted use and at the lower end of the risk
management range for industrial use. The HI is
less than 1 for both unrestricted use and industrial
use. Although the risk for unrestricted use is
within the risk management range, there is
uncertainty remaining because SSG samples were
only collected from three locations in the
southern portion of SA 098. The SSG COCs are
naphthalene and chloroform.
Risk is within the risk management range for both
unrestricted use and industrial use. The HI is less
than 1 for both unrestricted use and industrial use.
Arsenic is the main driver of soil risk, but soil
concentrations are below background. Excluding
arsenic, soil risks are below the risk management
range for unrestricted use and industrial use. No
soil COCs were identified.
There are potential impacts to groundwater quality
from arsenic; however, soil concentrations are
below background. Soil data do not indicate
potential impacts to surface water.
VOC2 (ICs)
N/A
SA 101
This 31,000-square foot site consists of the former location of
Building T-57, a radiochemical laboratory that operated from
1943 to 1971, when it was demolished. The building was a
semi-permanent wood structure set on a concrete foundation
that was reportedly used as the central kitchen, until World
War II when it was converted into a laboratory. A sump and
sump pump were in the southwest corner of the building. It is
unclear if the building or sump drained to the IWL or the
sanitary sewer system. The site is currently an asphalt-paved
parking lot. SA 101 was within the radius of influence of the
IC 32 SVE system.
Surface and subsurface releases
as a result of activities
conducted at the radiochemical
laboratory
Prior to 2017, only screening-level SSG data are
available for SA 101, and none of the screening-
level data contained VOCs at concentrations
greater than screening levels. There is uncertainty
regarding SSG characterization, because only two
soil gas samples were collected (both at depths of
21.5 ft), and not within 15 feet bgs.
In 2017, an interim SSG data gap investigation
was completed to verify the CSM and to provide
supporting information within the Site boundaries
and included the collection of two SSG samples
at 7 feet bgs. Chloroform, ethylbenzene, PCE,
TCE, 1,2,4-TMB, 1,3,5-TMB, and o-xylene were
detected, but only chloroform was detected at
concentrations above the IC compliance levels.
Therefore, the SSG COC is chloroform.
No COPCs were identified so an updated risk
assessment was not conducted.
Soil data do not indicate potential impacts to
groundwater or surface water quality. No metals
were detected above background levels and no
other analytes were detected. No soil COCs were
identified.
VOC3 (ICs/ECs)
N/A
43
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Silc l-'e:ilures
Soiircc/I'olenliiil Sources
of ('oiKiiiniiiiilion
Shallow Soil (l;is
Soil3
Selected kcmcdiiil
Allern:ili\e(s)b
T:ir»cl
\ 01 u in ec
SA 102
This 21,000-square foot site is the former location of Building
361, a masonry shack, and an abandoned bermed washrack.
The southeastern side of Building 361 was used as a paint
shop, where small paint jobs were performed on repaired
equipment. The southwestern side of the building was used
for vehicle repairs. The north end of Building 361 was used
as storage for rigging equipment. The washrack was used to
steam-clean machinery parts, such as gear boxes, and releases
during operations at the washrack may have impacted the
surface soil. The section of the IWL under Building 361 was
reported in poor condition prior to repairs in 1988. SA 102
was under the influence of the IC 31 SVE system, which
operated from September 1996 to January 2008.
Potential releases of solvents
and wastes discharged to IWL
drains may have impacted the
subsurface soil.
Risk is above the risk management range for both
unrestricted use and industrial use. The HI is
greater than 1 for both unrestricted use and
industrial use. The SSG COCs are benzene,
carbon tetrachloride, chloroform, cis-l,2-DCE,
1,4-DCB, ethylbenzene, naphthalene, 1,2,4-TMB,
1,3,5-TMB, m,p-xylene, o-xylene, PCE, and
TCE.
Risk is above the risk management range for
unrestricted use and within the risk management
range for industrial use. The HI is greater than 1
for unrestricted use and less than 1 for industrial
use. Arsenic concentrations detected using Method
SW7060 were below background. Excluding
arsenic, risk is within the risk management range
for unrestricted use, and below the risk
management range for industrial use. Without
arsenic, the HI for the residential scenario is less
than 1. The 2,4-dinitrotoluene detection is
considered isolated.
Data indicate potential impacts to groundwater
quality from arsenic and TPH-G and to surface
water quality from PCBs. TPH-G was detected in
a single sample at 3 feet bgs, only slightly
exceeded the concentration for protection of
groundwater, and was not detected at 8 feet bgs in
the same boring, so it was not identified as a COC.
The arsenic concentrations showing potential
impacts to groundwater are below background or
were analyzed using an unreliable analytical
method.
The soil COCs are PCBs and 2,4-dinitrotoluene.
VOC3 (ICs/ECs)
Non-VOC2 (ICs/ECs
and Monitoring)
N/A
Notes:
a) The term "screening level" is used in the soil discussion, which refers to the values that were used in the RICS/FS to determine risk and designate COCs. This evaluation included human health levels, protection of surface water levels, and protection of groundwater levels.
b) The remedy selections are based on the SSG and soil risks, as detailed in Section 2.12.5.
c) The parenthetical notations in this column indicate the basis for the target volume. For example, "(restricted)" indicates the target volume is based on the volume of soil that exceeds restricted use cleanup levels, while "(groundwater)" indicates the target volume is based on the
volume of soil that exceeds cleanup levels for the protection of groundwater quality. Similarly, "(surface water)" indicates that the target volume is based on the volume of soil that exceeds cleanup levels established by the Central Valley Water Board for the protection of surface
water.
d) Indicates the costs and volumes for the remedy were revised based on completion of the SVS and Building 252 Radiological NTCRA.
AOC area of concern
AST aboveground storage tank
bgs below ground surface
COC contaminant of concern
COPC contaminant of potential concern
CS confirmed site
CSM conceptual site model
cy cubic yards
DCA dichloroethane
DCB dichlorobenzene
DCE dichloroethene
EC engineered control
F2 the portion of the IRP site within FOSET #2
HI Hazard Index
IC institutional control
IC (#) investigation cluster (used with a numeral to identify SVE investigation/cleanup areas)
IWL industrial wastewater line
IWTP industrial wastewater treatment plant
mg/kg milligrams per kilogram
N/A not applicable
No. number
OWS oil and water separator
44
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
PAH polycyclic aromatic hydrocarbon
PCA tetrachloroethane
PCBs polychlorinated biphenyls
PCE tetrachloroethene
PCG preliminary cleanup goal
ppbv parts per billion by volume
PRL potential release location
ROD record of decision
SA study area
SSG shallow soil gas
SVE soil vapor extraction
SVOC semi-volatile organic compound
TCE trichloroethene
TMB trimethylbenzene
TPH-D total petroleum hydrocarbons as diesel
TPH-G total petroleum hydrocarbons as gasoline
TPH-JP4 total petroleum hydrocarbons as jet fuel
UST underground storage tank
VOC volatile organic compound
45
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
2.5.1 Topography, Geology, and Hydrology
The former McClellan AFB is located in the Sacramento Valley. The regional topography slopes gently
westward toward the Sacramento River. The FOSET #2 Group 2 Action Sites are located in the
northeastern, central and southeastern sections of the former McClellan AFB, and the surface elevation in
this area is approximately 75 feet above mean sea level.
The vadose zone is the unsaturated soils between the ground surface and the water table. The vadose zone
is approximately 95 to 110 feet thick, and the saturated (groundwater) zone is approximately 1,000 feet
thick. The vadose zone and the shallow groundwater zone, to 450 feet bgs, are the zones most likely to be
affected by contamination (CH2MHill, 2012).
Groundwater flow directions have varied over the past 80 years, but they have persisted in a south-to-
southwesterly direction over the past several decades. Deposits on the east side of the former McClellan
AFB include more fine-grained sediments. In the eastern portions of the former McClellan AFB in
Monitoring Zone A, relatively thinner saturated thicknesses and increased percentages of fine-grained
sediments result in relatively lower transmissivity than in the western portions of the former McClellan
AFB. Contaminant transport is inhibited, but not prevented, by lower permeability layers, both in the
vadose and saturated zones. The relatively higher transmissivity in the western portions of the former
McClellan AFB results in relatively greater potential for contaminant transport (CH2MHill, 2012).
2.5.2 Ecological Characteristics
Impact from the FOSET #2 Group 2 Action Sites to ecological habitat was evaluated. The FOSS RICS/FS
and the SVS RICS/FS concluded that there was no significant ecological habitat within the FOSET #2
boundaries, only downgradient of the sites; therefore, no further ecological investigation was recommended
at the Group 2 Action Sites.
2.6 CURRENT AND POTENTIAL FUTURE LAND AND RESOURCE USES
Much of the land surrounding the former McClellan AFB, particularly to the west, is zoned for low-density
residential and agricultural use. Historical land use at the FOSET #2 Group 2 Action Sites included
industrial and commercial usage. Based on the McClellan Reuse Plan (EDAW, 2000) and the McClellan
Park Special Planning Area (Ordinance No. SZC-2002-0029) (County of Sacramento, 2002), all of the
FOSET #2 Group 2 Action Sites are located within areas designated for industrial or industrial/commercial
land use.
There are no current or future planned uses of groundwater at or in the vicinity of any of the FOSET #2
Group 2 Action Sites. Groundwater use is prohibited by restrictions described in the VOC Groundwater
ROD (AFRPA, 2007). There are no current or future human uses (e.g., drinking water, irrigation, or
recreational) of surface waters at or in the vicinity of any of the FOSET #2 Group 2 Action Sites. However,
in accordance with the tributary rule of the Water Quality Control Plan (the Basin Plan) for the Sacramento
River and San Joaquin River Basins, Magpie Creek would have a designated use as drinking water. There
are seasonal drainage ditches and creeks, seasonal wetlands, and vernal pools in the vicinity of the FOSET
#2 Group 2 Action Sites. The seasonal drainage features contribute to downstream receiving waters which
empty into the Sacramento River. The potential beneficial uses of the receiving waters include drinking,
irrigation, and recreational. The downstream seasonal wetlands and vernal pools serve as habitat for various
aquatic species.
47
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
2.7 SUMMARY OF SITE RISKS
McClellan Park is a very large and complex Superfund Site with multiple Records of Decision that address
contamination at approximately 316 individual sites in varying media. The 45 FOSET #2 Group 2 Action
Sites have varying degrees of potential risks to human health. Many of the individual sites addressed in past
McClellan decisions (RODs) overlie or potentially impacted other sites, which may increase the cumulative
risk associated with FOSET #2 Group 2 Action Sites. The possible reduction of risk from interim or
remedial actions were not considered during the development of this ROD, nor was the risk from
groundwater contamination included in the cumulative risk assessments for the individual sites.
Contamination at some of the sites also pose potential threats to surface water and/or groundwater quality.
The potential for migration to surface water and groundwater was determined by comparing detected
concentrations of COCs to the screening levels for protection of surface water and groundwater quality.
Screening levels for protection of surface water were applied to surface soils (0 to 1 foot bgs). Screening
levels for protection of groundwater were applied from 0 to 15 feet bgs.
2.7.1 Conceptual Site Model
A Conceptual Site Model (CSM) was used to develop an understanding of a site and to evaluate potential
risks to human health and the environment. CSMs for the 45 FOSET #2 Group 2 Action Sites examined
VOC contamination in shallow soil and shallow soil gas, as well as non-VOCs in soil. The VOC and non-
VOC components of this model were developed in accordance with EPA's guidance and include known
and suspected sources of contamination, types of contaminants and affected media, known and potential
routes of migration, and known or potential human and ecological receptors. Information for the
contaminant sources, transport pathways, and receptors to aid in remedy selection are depicted
schematically on Figure 2-1, which presents the conceptual site model for the shallow soil and vapor
intrusion pathway, and Figure 2-2, which presents the exposure pathway analysis. Site-specific CSM
descriptions can be found in the Small Volume Sites RICS Addenda and FS (CH2MHill, 2011) and the
Follow-on Strategic Sites RICS and FS (CH2MHill, 2012).
2.7.2 Human Health Risks
The baseline risk assessment estimates what risks a site would pose if no further action were taken. It
provides the basis for taking action and identifies the contaminants and exposure pathways that need to be
addressed by the remedial action. This section of the ROD summarizes the results of the baseline risk
assessments for the FOSET #2 Group 2 Action Sites. As stated in the Risk Assessment Guidance for
Superfund, Volume I, Human Health Evaluation Manual (Part A) (EPA, 1989), baseline risk assessments
are site-specific and therefore may vary in both detail and the extent to which qualitative and quantitative
analyses are used. There are four elements required in a baseline risk assessment process: identification of
COCs, exposure assessment, toxicity assessment, and risk characterization. Baseline human health risk
assessments were conducted for each of the FOSET #2 Group 2 Action Sites using the process outlined in
the following subsections.
2.7.2.1 Identification of Contaminants of Concern
Analytical data used to identify the COCs for the risk assessment include those from subsurface soil (0 to
10 feet bgs) and VOCs in soil gas (0 to 15 feet bgs) collected within the exposure areas of the various
FOSET #2 Group 2 Action Sites. The subsurface soil depth intervals are used to represent future conditions
if construction activities disturb subsurface soil and bring it to the surface to be mixed with surface soil.
48
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
All detected organic compounds in soil or soil gas were retained as COCs for the risk assessment, with one
exception: VOCs in soil were not retained as COCs because VOCs are evaluated in soil gas. Some
inorganic compounds are considered to be beneficial to human health or may be present only at naturally
occurring levels. For this reason, an inorganic chemical was retained as a COC in the risk assessment for
soil if:
• It was detected in a depth interval for which at least one exposure pathway was considered to be
complete;
• It is not an essential human nutrient (EPA, 1989); or
• Detected concentrations exceeded recognized ambient levels at the former McClellan AFB.
COCs were identified separately by site. For each site, Table 2-2 summarizes the commercial/industrial
carcinogenic human health risk and non-carcinogenic hazard and Attachment C summarizes the
commercial/industrial and residential carcinogenic risk and non-carcinogenic hazard. For each soil COC,
the maximum detected concentration was used as the exposure point concentration (EPC). Soil gas data
were evaluated on a sample-by-sample basis so EPCs are the detected concentrations of VOCs for an
individual soil gas location. For the indoor air evaluation, it was assumed that a receptor's exposure will
primarily be at one building. Therefore, rather than generating a single point estimate of exposure or risk
across an exposure area (i.e., using 95 percent upper confidence limit EPCs for soil gas or a single point
represented by the maximum detected concentrations), the VOCs detected in soil gas were evaluated on a
sample-by-sample basis, in which each sample location represents an exposure point. This approach
provides information on the spatial distribution of potential risk across the site, allowing the display of
potential risk levels for specific portions of the FOSET #2 Group 2 Action Sites that are in the vicinity of
buildings or in areas where buildings may be constructed in the future.
Chemical-specific concentrations for each site (i.e., maximum and minimum concentrations, frequency of
detection) are presented for each site in the SVS RICS Addenda and FS (CH2MHill, 2011) and the Follow-
on Strategic Sites RICS and FS (CH2MHill, 2012).
2.7.2.2 Exposure Assessment
The exposure pathways that were included in the calculation of the human health risks are illustrated in
Figure 2-1 and Figure 2-2 (CH2MHill, 2012). For non-VOCs in soil, the exposure pathways were soil
ingestion, skin contact with soil, inhalation, and homegrown produce ingestion. For VOCs in shallow soil
gas, the only exposure pathway was inhalation of VOCs emitted from soil into indoor air. The potentially
exposed populations were hypothetical future residents, current and future outdoor occupational and
construction workers, and future indoor occupational workers. Based on the current understanding of land
use conditions at and near the site, an occupational worker scenario was considered and evaluated at the
FOSET #2 Group 2 Action Sites. The commercial/industrial (occupational worker) scenario includes
indoor occupational workers, outdoor occupational workers, and construction workers. Although
residential land use is not planned for any of the FOSET #2 Group 2 Action Sites at this time, residential
exposure scenarios (adults and children; indoor and outdoor exposure) were evaluated to provide
information on future risk management decisions.
Children and families that consume produce grown onsite are considered sensitive subpopulations.
Potential exposures of these two groups were considered by including 6 years of childhood exposure and
ingestion of homegrown produce in the development of the screening levels for the unrestricted use
scenario.
49
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
T
BUILDING ZONE
OF INFLUENCE
AIR STREAMLINES
AOVECTION
ADVECTION
VADOSE ZONE
CONVECTION CONVECTION
VQC CONTAMINATED
SOIL AND SOL GAS
DIFFUSION
DIFFUSION
CONCEPTUAL MODEL FOR VOCs
IN SHALLOW SOIL GAS -
VAPOR INTRUSION PATHWAY
SVS RICSADOENDAAND FS
FORMER McClEllAN AJR FORCE EASE
SACRAMENTO, CALIFORNIA
CH2MHILL
Figure 2-1 Conceptual Model for Vapor Intrusion Pathway
50
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Primary Sources
Surficial Sources
Primary
Release
Mechanisms
Secondary Sources
Secondary
Release
Mechanisms
Exposure
Media
Sumps
Aboveground Tanks and Petroleum Oil and
Lubricant (POL) Lines
Surface Runoff, Ditches, Washracks
Buildings
Spills, Storage Areas
> Volatilization
Air Indoor
Air Dispersion/
Particle Deposition
Dust
Wind
Dispersion
Water Erosion
Stormwater
Runoff
Air Outdoor
Bioaccumulation
Biota (plants.
Invertebrates,
vertebrates)
-> Dispersion in Soil
Surface Water
Vadose Zone (includes soil and
unsaturated overburden)
Infiltration
Subsurface Sources
Underground Tanks and Petroleum Oil and
Lubricant (POL) Lines
Ditches, OilA/Vater Separators
Other, Buildings
Spills
IWL Lines
Sewer Lines
Disposal Pits
Percolation/
Lateral Flow
Sorbed to
Dissolved in
Solids
Porewater
Excavation
Exposure
Routes
Human Receptors
Ecological Receptors***
Hypothetical
Residential
Outdoor
Occupational
Indoor
Occupational
Construction
Workers
Aquatic
Terrestrial
Plants
Inverts
M8IJ
Birds
Mammals
Plants
Inverts
Fish
Birds
Mammals
Inhalation
•
o • [o
o
o
o o
o
o
o
o o
o
Inhalation
•
•
o
•
©| ©
© 0
©
©
©
©
0
0
Ingestion**
•
o
o
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©
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©
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0
©
Ingestion
o
o
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©
©
©
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©
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o
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•
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o
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0
Root Uptake
o
o
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o
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Ingestion
•
•
o
•
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•
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•
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•
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NOTES
• Potentially complete pathways addressed in this report.
© Potentially complete pathway, but not addressed in this report.
O Incomplete pathway for this scenario.
** Plants may take up contaminants and hypothetical residents may be exposed
through ingestion of homegrown produce affected by contaminants.
*** For the sites included in this report, there is no significant ecological habitat.
Therefore, no complete exposure pathway exists tor ecological receptors.
EXPOSURE PATHWAY ANALYSIS
SVS RICS ADDENDA AND FS
FORMER McCLELLAN AIR FORCE BASE
SACRAMENTO, CALIFORNIA
Figure 2-2 Exposure Pathway Analysis
51
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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52
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
2.7.2.3 Toxicity Assessment
Chemicals detected at each site were evaluated as two groups based on their effects on human health:
carcinogens (cancer-causing) and non-carcinogens (may cause adverse health effects other than cancer).
Chemicals classified as carcinogens may also exhibit non-carcinogenic health effects, thus these effects
were also evaluated. For potential carcinogens, the quantitative risk to human health is expressed in terms
of the probability of the chemical causing cancer over an estimated lifetime of 70 years. For non-cancer
effects, the likelihood that a receptor will develop an adverse effect is evaluated as a predicted level by
comparison to the highest level of exposure that is considered protective. For non-carcinogens, the potential
impact to human health is expressed as a hazard quotient (HQ) for each exposure route (e.g., ingestion,
dermal contact, and inhalation) and the hazard index (HI) is the sum of all the HQs for all chemicals to
which adverse health effects are possible.
Additionally, exposure to lead was evaluated separately by comparison to risk-based levels estimated for
occupational workers and residents.
2.7.2.4 Risk Characterization
For carcinogens, risks are generally expressed as the incremental probability of a population of individuals
developing cancer over a lifetime as a result of exposure to the carcinogen. Excess lifetime cancer risk is
calculated from the following equation:
Risk = CDI x SF
where:
Risk = a unitless probability (e.g., 2 x 105) of a population of individuals developing cancer
CDI = chronic daily intake averaged over 70 years (milligrams per kilograms per day [mg/kg-day])
SF = slope factor, expressed as (mg/kg-day )J
These risks are probabilities that are expressed in scientific notation (e.g., 1 x 10 6). An excess lifetime
cancer risk of 1 x 10 6 indicates that a population of individuals experiencing the reasonable maximum
exposure estimate has a 1 in 1,000,000 chance of developing cancer as a result of site-related exposure.
This is referred to as an "excess lifetime cancer risk" because it would be in addition to the risks of cancer
individuals face from other causes such as smoking or exposure to too much sun. The chance of a
population of individuals developing cancer from all other causes has been estimated to be as high as one
in three. EPA's generally acceptable risk range for site-related exposures is 1 / 1Q-4 to 1 / 10-6.
Determination of what constitutes acceptable levels of residual risk within this range is made on a site-
specific basis.
The potential for non-carcinogenic effects is evaluated by comparing an exposure level over a specified
time period (e.g., lifetime) with a reference dose (RfD) derived for a similar exposure period. An RfD
represents a level that a population of individuals may be exposed to that is not expected to cause any
deleterious effect. An HQ is the ratio of exposure to toxicity. An HQ less than 1 indicates that a receptor's
dose of a single contaminant is less than the RfD, and that toxic non-carcinogenic effects from that chemical
are unlikely. The HI is generated by adding the HQs for all COCs that affect the same target organ (e.g.,
liver) or that act through the same mechanism of action within a medium or across all media to which a
given population of individuals may reasonably be exposed. An HI less than 1 indicates that, based on the
sum of all HQs from different contaminants and exposure routes, toxic non-carcinogenic effects from all
53
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
contaminants are unlikely. An HI greater than 1 indicates that site-related exposures may present a risk to
human health.
The HQ is calculated as follows:
Non-cancer HQ = CDI/RfD
where:
CDI = chronic daily intake
RfD = reference dose
CDI and RfD are expressed in the same units and represent the same exposure period (i.e., chronic [7 years
or more], subchronic [2 weeks to 7 years], or short-term [less than 2 weeks]).
Uncertainties associated with the calculation of the risk-based screening levels could affect the risk
estimates developed using the screening levels. These uncertainties include the following:
• Use of the residential exposure assumptions - The current and reasonably anticipated future land
use for the FOSET #2 Group 2 Action Sites is industrial or industrial/commercial. Use of screening
levels based on residential exposure assumptions might result in chemicals being identified as
COCs that would not be COCs using the industrial exposure parameters. It will tend to
overestimate potential risk by including the homegrown produce pathway, increasing exposure
times, and including exposures to a child.
• Homegrown produce pathway - Plant root uptake of metals was only evaluated for the six metals
included in EPA's Soil Screening Guidance (EPA, 1996) because the soil partition coefficients
values available in literature for other metals were not as well defined as the Soil Screening
Guidance values. Leaving plant root uptake out of the evaluation of the homegrown produce
pathway for some metals will tend to underestimate risk via the homegrown produce pathway for
those metals.
• Route-to-route extrapolation for toxicity factors - For some chemicals, cancer SFs or RfDs have
only been established for one exposure route. In those cases, toxicity values were extrapolated
across exposure routes. For instance, oral toxicity values were used to evaluate inhalation exposure
in some cases. This simple extrapolation method allows a pathway for which no cancer SFs or
RfDs have been defined to be evaluated. However, it also introduces uncertainties into the risk
estimates because it does not account for differences in "port-of-entry" effects or pharmacokinetics
(i.e., what the body does to the chemicals). The contribution from the exposure route for which the
extrapolated toxicity factor was used might be overestimated or underestimated. The contribution
from dermal exposure might be underestimated because no adjustment was made to the oral toxicity
values used for the dermal route.
For lead, risks were evaluated by comparing soil concentrations with California Human Health Screening
Levels (CHHSLs) by Cal-EPA (2009). The CHHSLs are based on a source-specific "benchmark change"
of 1 microgram per deciliter (|ig/dL) blood concentration of lead. The residential CHHSL value of 80
milligrams per kilogram (mg/kg) was adopted as the unrestricted screening level, and the industrial CHHSL
of 320 mg/kg was adopted as the industrial screening level. These levels are to be considered (TBC) when
selecting a remedy.
54
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Results of the quantitative risk assessment conducted for each site are presented in Table 2-2 for the
commercial/industrial occupational worker and in Attachment C for both the commercial/industrial
occupational worker and future resident. The tables present cancer risks and non-cancer hazards for each
site using color codes to indicate the level of concern for consideration of remedial action. Green indicates
a risk below the risk management range, yellow within the risk management range, and red above the risk
management range. Table 2-2 also includes risk drivers (i.e., COCs). The maximum estimated risk to a
commercial/industrial (occupational) worker for combined exposure to soil and SSG is provided in
Attachment D for each Action Site. The maximum estimated risk was determined by adding the
commercial/industrial risk value for soil to the highest commercial/industrial risk value for soil vapor. This
value was included to represent the total risk from all soil exposure pathways and to support the rationale
discussion for the selected remedies.
Individual human health risk assessments (HHRAs) for the FOSET #2 Group 2 Action Sites were conducted
for exposure to chemicals in soil only; groundwater characterization was not considered part of the
investigation.
In general, calculated cumulative cancer risks greater than 1 x 10~4 and His greater than 1 require
consideration of cleanup alternatives. Cancer risks between 1 * 10"4 and 1 x 10"6 (between 1 in ten-thousand
and 1 in one-million) fall within EPA's risk management range. Determination of what constitutes
acceptable levels of residual risks within this range is decided on a site-specific basis, considering the degree
of conservatism and inherent uncertainty associated with the risk assessment. Cumulative incremental
lifetime cancer risk related to site contamination below 1 x 10"6 is considered a de minimis level and
typically does not warrant active risk/exposure mitigation.
55
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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56
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Table 2-2 Summary of Cancer Risks and Non-carcinogenic Hazards for the FOSET #2 Group 2 Action Sites in a Restricted Use Scenario
Site
Commercial/Industrial Risk
Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Carcinogenic Risk
Non-carcinogenic HI
Carcinogenic Risk
Non-carcinogenic HI
Soil
Shallow Soil Gas
AOC 325
7E-6
<1
4E-6
< 1
Arsenic*
Benzo(a)pyrene
Vanadium
Chloroform
Naphthalene
VOC3
Non-VOC2
CS P-005
5E-6
< 1
1E-6
< 1
Arsenic*
Aroclor 1260
Naphthalene
1.2.4-TMB
1.3.5-TMB
VOC2
Non-VOC2
CS P-006
4E-5
< 1
9E-5
< 1
Dioxins/Furans
Benzo(a)anthracene
Benzo(a)pyrene
Cadmium
PCE
TCE
Cis-1,2-DCE
1.2.4-TMB
1.3.5-TMB
VOC3
Non-VOC2
CS S-021
5E-6
< 1
7E-6
< 1
Arsenic*
PCE
TCE
Chloroform
Cis-1,2-DCE
1,2,4-TMB
1,4-DCB
VOC3
CS S-027
4E-6
< 1
1E-5
< 1
Arsenic*
Naphthalene
PCE
1,4-DCB
1.2.4-TMB
1.3.5-TMB
VOC3
CS T-037
6E-6
< 1
7E-6
< 1
Arsenic*
Aluminum*
Cobalt*
PCE
TCE
Cis-1,2-DCE
1,2,4-TMB
VOC3
CS T-059
1E-8
< 1
1E-6
< 1
None
Naphthalene
1.2.4-TMB
1.3.5-TMB
VOC2
PRLL-001 (F2)
7E-5
< 1
7E-6
< 1
Arsenic
Vanadium
PAHs
PCE
TCE
Cis-1,2-DCE
1.2.4-TMB
1.3.5-TMB
VOC3
Non-VOC2
PRL L-002
2E-5
< 1
4E-3
29
Arsenic*
Cadmium
Benzo(a)pyrene
TCE
Cis-1,2-DCE
1,2,4-TMB
VOC3
Non-VOC2
57
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Commercial/Industrial Risk
Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Carcinogenic Risk
Non-carcinogenic HI
Carcinogenic Risk
Non-carcinogenic HI
Soil
Shallow Soil Gas
PRL L-003 (F2)
1E-5
< 1
6E-6
< 1
Arsenic*
Aluminum*
Benzo(a)anthracene
Benzo(a)pyrene
PCE
TCE
Carbon Tetrachloride
VOC3
Non-VOC2
PRL L-004
1E-5
< 1
1E-5
4
Arsenic*
Cadmium*
2-methylnaphthalene
PCE
TCE
1,4-DCB
Naphthalene
Ethylbenzene
Chloroform
Vinyl Chloride
1.2.4-TMB
1.3.5-TMB
VOC3
Non-VOC4a
PRL L-005 (F2)
8E-6
< 1
2E-5
< 1
Arsenic*
Vanadium
PCE
VOC3
PRL P-001
3E-7
< 1
8E-7
< 1
Cadmium
Vanadium
Aroclor-1254
Cliloroform
Carbon Tetracliloride
TCE
PCE
1,1-DCE
Naphthalene
Benzene
Non-VOC2
PRL P-003
N/A
N/A
1E-6
< 1
None
PCE
TCE
Naphthalene
Ethylbenzene
Benzene
VOC2
PRL P-004
3E-6
< 1
6E-7
< 1
Arsenic*
TCE
Cliloroform
Cis-1,2-DCE
PCE
Benzene
VOC3
58
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Commercial/Industrial Risk
Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Carcinogenic Risk
Non-carcinogenic HI
Carcinogenic Risk
Non-carcinogenic HI
Soil
Shallow Soil Gas
PRL S-022 & SA 069
1E-5
< 1
4E-6
< 1
Arsenic*
Benzo(a)pyrene
PCE
TCE
Carbon Tetrachloride
Chloroform
VOC3
Non-VOC4a
PRL S-037
N/A
N/A
1E-6
< 1
None
1,1,2,2-TCA
1,3-Butadiene
Carbon Tetrachloride
PCE
Ethylbenzene
Benzene
VOC2
PRL T-015
9E-9
< 1
3E-7
< 1
Thallium
1.2.4-TMB
1.3.5-TMB
Naphthalene
Ethylbenzene
Benzene
PCE
VOC2
Non-VOC4a
PRL T-019
1E-9
< 1
2E-7
< 1
Thallium*
Naphthalene
Benzene
PCE
TCE
Non-VOC2
PRL T-031
1E-5
< 1
1E-5
< 1
Arsenic*
Vanadium
Manganese*
Chloroform
Benzene
1,2,4-TMB
PCE
TCE
Cis-1,2-DCE
VOC3
Non-VOC2
PRL T-033
2E-5
< 1
5E-6
< 1
Arsenic*
Cadmium*
Vanadium*
Aroclor-1254
Aroclor-1260
PAHs
TCE
Chloroform
Naphthalene
N-propylbenzene
Xylenes
1.2.4-TMB
1.3.5-TMB
VOC3
Non-VOC2
SA037
5E-6
< 1
3E-6
< 1
Arsenic*
Aluminum*
Thallium*
PCE
TCE
Chloroform
Benzene
VOC2
SA038
N/A
N/A
3E-7
< 1
None
Benzene
VOC2
59
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Commercial/Industrial Risk
Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Carcinogenic Risk
Non-carcinogenic HI
Carcinogenic Risk
Non-carcinogenic HI
Soil
Shallow Soil Gas
Ethylbenzene
Methylene Chloride
PCE
TCE
Chloroform
Non-VOC2
SA040
1E-5
< 1
9E-8
< 1
Arsenic*
Cadmium
Cobalt
Carbon Tetrachloride
Chloroform
Benzene
Ethylbenzene
PCE
TCE
VOC2
Non-VOC2
SA043
6E-6
< 1
1E-6
< 1
Arsenic
Cobalt
Zinc
Cadmium
Benzene
Naphthalene
MTBE
PCE
TCE
Methylene Chloride
VOC2
Non-VOC2
SA044
3E-10
< 1
N/A1
N/A1
Thallium*
TCE
VOC3
SA047
7E-6
< 1
7E-7
< 1
Arsenic*
Cadmium
Cobalt
Vanadium
Chloroform
PCE
TCE
Benzene
Ethylbenzene
Naphthalene
VOC2
Non-VOC2
SA048
9E-11
< 1
2E-6
< 1
None
Benzene
Chloroform
Ethylbenzene
Methylene Chloride
MTBE
Naphthalene
VOC2
SA053
3E-6
< 1
8E-6
< 1
Arsenic*
Thallium
TCE
PCE
Carbon tetrachloride
Ethylbenzene
Naphthalene
Chloroform
Hexachlorobutadiene
VOC3
SA058
3E-6
< 1
1E-4
< 1
Arsenic*
Carbon Tetrachloride
VOC3
60
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Commercial/Industrial Risk
Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Carcinogenic Risk
Non-carcinogenic HI
Carcinogenic Risk
Non-carcinogenic HI
Soil
Shallow Soil Gas
Chloroform
PCE
SA059
5E-7
< 1
4E-7
< 1
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Aluminum
Vanadium
Naphthalene
Hexachlorobutadiene
Chloroform
Chloromethane
Benzene
Ethylbenzene
Methylene Chloride
PCE
1,4-DCB
TCE
VOC2
Non-VOC2
SA067
3E-6
< 1
2E-7
< 1
Arsenic*
Cobalt*
Benzene
Ethylbenzene
Naphthalene
PCE
TCE
Chloroform
Vinyl Chloride
1,4-DCB
VOC3
SA068
6E-8
< 1
9E-8
< 1
Cobalt*
Benzene
Ethylbenzene
1,4-DCB
PCE
TCE
Carbon Tetrachloride
Chloroform
Naphthalene
Methylene Chloride
VOC2
SA071
1E-5
< 1
7E-7
< 1
Arsenic*
Cadmium
Vanadium
Chloroform
Methylene Chloride
PCE
TCE
Benzene
VOC2
Non-VOC2
SA073
N/A1
N/A1
N/A1
N/A1
None
None
VOC2
Non-VOC2
SA077
3E-6
< 1
2E-6
< 1
Arsenic*
Benzene
Carbon Tetrachloride
Ethylbenzene
VOC2
61
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Commercial/Industrial Risk
Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Carcinogenic Risk
Non-carcinogenic HI
Carcinogenic Risk
Non-carcinogenic HI
Soil
Shallow Soil Gas
1,4-DCB
Naphthalene
PCE
Chloroform
SA078
5E-6
< 1
2E-7
< 1
Arsenic*
Benzene
Carbon Tetrachloride
Chloroform
Ethylbenzene
Hexachlorobutadiene
Naphthalene
PCE
TCE
Non-VOC2
SA079
1E-5
< 1
1E-5
4
Arsenic*
Aluminum
2-Methylnaphthalene
1,4-DCB
Chloroform
Ethylbenzene
Naphthalene
PCE
TCE
Cis-U-DCE
Vinyl Chloride
1.2.4-TMB
1.3.5-TMB
VOC3 and Non-VOC2
SA081
9E-6
< 1
5E-6
< 1
Arsenic*
Cadmium
Thallium
Dioxins
PAHs
Naphthalene
2-Methylnaphthalene
Vinyl Chloride
TCE
Xylenes
Naphthalene
1.2.4-TMB
1.3.5-TMB
VOC3
Non-VOC4a
SA086
2E-7
< 1
8E-7
< 1
Cadmium*
Benzene
Ethylbenzene
Naphthalene
PCE
1.2.4-TMB
1.3.5-TMB
VOC2
Non-VOC2
SA094
4E-6
< 1
1E-6
< 1
Arsenic*
Benzo(a)pyrene
Benzene
Methylene Chloride
MTBE
Naphthalene
VOC2
Non-VOC2
62
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Commercial/Industrial Risk
Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Carcinogenic Risk
Non-carcinogenic HI
Carcinogenic Risk
Non-carcinogenic HI
Soil
Shallow Soil Gas
SA098
5E-6
< 1
1E-6
< 1
Arsenic*
Benzene
Ethylbenzene
Naphthalene
Chloroform
TCE
PCE
VOC2
SA 101
N/A1
N/A1
N/A1
N/A1
None
Chloroform
VOC3
SA 102
7E-6
< 1
4E-3
29
Arsenic*
2,4-Dinitrotoluene
TCE
PCE
Cis-U-DCE
1,2,4-TMB
VOC3
Non-VOC2
Notes: Green indicates a risk below the risk management range, yellow indicates risk within the risk management range, and red indicates risk above the risk management range.
*Metals concentrations are below or within the range of background for soils, detected with an unreliable analytical method, or not considered to be representative of site contamination. Excluding the listed metal, the soil risk is below or at the low end of the risk management range and/or
the HI is less than 1.
1) Although additional data was collected during 2017 data gap sampling investigation, no risk assessments were conducted following the data collection, so the risk values have not been revised.
AOC area of concern
COC contaminant of concern
CS confirmed site
DCB dichlorobenzene
DCE dichloroethene
F2 the portion of the IRP site within FOSET #2
HI Hazard Index
MTBE methyl-tert-butyl ether
N/A Not available, risk values were not calculated because samples were not collected, chemicals of potential concern (COPCs) were not identified, or sufficient data was not available
PAH polycyclic aromatic hydrocarbon
PCA tetrachloroethane
PCE tetrachloroethene
PRL potential release location
SA study area
TCE trichloroethene
TMB trimethylbenzene
VOC volatile organic compound
63
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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64
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
2.7.3 Ecological Risks
In cooperation with regulatory/resource agencies, the Air Force evaluated all IRP sites for their potential to
affect downgradient habitats, including creeks, wetlands, and vernal pools. The basewide creeks program
evaluates potential impacts to creeks, and any IRP site that was identified as having potential to affect
downgradient vernal pools was retained for evaluation in the Basewide Vernal Pool Scoping Level/Tier 1
ERA (Parsons, 2005). Based on the results of the Scoping Level/Tier 1 ERA, none of the FOSET #2 Group
2 Action Sites was retained for further evaluation in a Tier 2 ERA.
The FOSS RICS/FS and the SVS RICS/FS evaluated impact from the FOSET #2 Group 2 Action Sites to
ecological habitat. The FOSS RICS/FS and the SVS RICS/FS concluded that there was no significant
ecological habitat onsite; therefore, no further ecological investigation was recommended at the Group 2
Action Sites.
2.7.4 Basis for Action
The basis for action at the 45 FOSET #2 Group 2 Action Sites is that one or more of the following is true
at each site: (1) cumulative excess carcinogenic risk to an individual exceeds 1 x 10~6, (2) the non-
carcinogenic HI is greater than 1, (3) chemical-specific levels for lead (based on blood lead levels) are
exceeded in soil, (4) soil contamination poses significant risks to surface water, (5) soil contamination poses
significant risks to groundwater, or (6) there is some remaining uncertainty regarding the characterization
of site contaminants or risks. No ecological habitat is present at the FOSET #2 Group 2 Action Sites, so
exposure of ecological receptors is not part of the basis for action. The specific basis of action for each site
is described in Table 2-1 and Attachment D. Based on the data presented in Table 2-1 and Attachment D,
the response action selected in this ROD is necessary to protect the public health or welfare or the
environment from actual or threatened releases of hazardous substances into the environment.
2.8 REMEDIAL ACTION OBJECTIVES
EPA, in conjunction with the Air Force, has developed RAOs to describe how the remedy is expected to
address site risks. These RAOs are based on current and future land uses and address exposure risks by
removing contamination and isolating potential receptors from remaining contamination. The RAOs are
as follows:
• For protection of human health, prevent inhalation, ingestion, direct contact, and external exposure
to shallow soil gas and soil within the upper 15 feet bgs posing excess cancer risk greater than the
CERCLA risk range (1 x 10-6 to 1 x 10 4) or an HI greater than 1.
• Protect surface water and groundwater quality and uses from contaminants in soil.
• Protect downgradient ecological receptors, such as vernal pools.
2.8.1 Basis and Rationale for Remedial Action Objectives
The RAOs were selected in consideration of the current land use and to support the anticipated future land
use. Current and anticipated future land use at the FOSET #2 Group 2 Action Sites is industrial or
industrial/commercial. Residential use and use by sensitive receptors (e.g., day care centers, public or
private schools for persons under 18 years of age, hospitals, etc.) will be prohibited. Surface water and
groundwater quality, as well as ecological receptors, will be protected.
65
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
2.8.2 How the Remedial Action Objectives Address Risks
The RAOs will address unacceptable risks identified in the risk assessment by preventing exposure to
ensure that after implementation of the remedies, the remaining risks will be below or within the risk
management range for the anticipated future land use. Because some of the selected remedies involve
leaving contamination in place that is acceptable for industrial use, ICs restricting residential use will be
implemented to ensure that land use does not change and prevent exposure to potential future residential
receptors.
2.8.3 Basis of Cleanup Levels
For human health, cleanup levels for all contaminants were calculated using inputs specific to the former
McClellan AFB (some of the exposure parameters used in the risk calculations, such as the homegrown
produce pathway, have been derived specifically for the former McClellan AFB) and represent the lesser
of the concentration equivalent to a 1 x 10 6 carcinogenic risk or the concentration equivalent to an HI of 1.
For soil, risk-based cleanup levels supportive of unrestricted use were developed for most contaminants
based on exposure via ingestion of soil, ingestion of homegrown produce, inhalation, and dermal contact.
Risk-based cleanup levels supportive of industrial use were developed based on exposure via ingestion of
soil, inhalation, and dermal contact. The cleanup levels for shallow soil gas are based on the vapor
inhalation pathway. Following attainment of the cleanup levels for the protection of human health, residual
risk associated with chemical constituents on an individual basis would be at or less than a carcinogenic
risk of 1 x 10-6 or a non-carcinogenic HI of 1 for industrial exposure.
Cleanup levels for lead in the soil from 1 to 15 feet bgs are based on DTSC's residential CHHSL of
80 mg/kg as the unrestricted use level, and the industrial CHHSL of 320 mg/kg as the industrial level. The
cleanup level for lead in surface soil (0- to 1-foot horizon) for protection of surface water is 140 mg/kg,
which represents a cleanup to the anthropogenic background levels for lead at the former McClellan AFB
(i.e., levels resulting from normal human activity). The cleanup levels for cadmium and cobalt in surface
soil (0 to 1 foot bgs) and for cobalt in subsurface soil (1 to 15 feet bgs) are based on the background
concentrations of these metals.
Cleanup levels for protection of human health were not developed for TPH-D and TPH-G. Instead, cleanup
levels for the protection of surface water quality and groundwater quality were selected as the cleanup levels
for TPH-D and TPH-G.
Cleanup levels for protection of groundwater from metals, SVOCs, and TPH in soil (0 to 30 feet bgs) were
derived separately. Cleanup levels for metals and TPH-D were calculated using the Designated Level
Methodology (DLM) (Central Valley Water Board, 1989). The basis used for the development of cleanup
levels for metals and TPH-D is either the maximum contaminant levels (MCLs) or TBC risk-based Water
Quality Limits (WQLs). For SVOCs and TPH-G, cleanup levels for protection of groundwater were
developed using vadose zone and groundwater mixing-cell models. The basis for the evaluation is either
MCLs or other risk-based WQLs. The MCLs or WQLs for each contaminant were identified in consultation
with the Central Valley Water Board.
Cleanup levels for the FOSET #2 Group 2 Action Sites are presented in Table 2-3 and levels for protection
of surface water and groundwater quality for use in evaluating the need for ICs/ECs are presented in Table
2-4. The levels for protection of surface water and groundwater quality apply to soil at the Group 2 Action
Sites and specify the concentrations at which ICs and/or ECs, such as maintenance of existing surface
covers, are required. SSGIC compliance levels are presented in Table 2-5. The SSGIC compliance levels
apply to soil vapor at the Group 2 Action Sites and specify the concentrations at which ECs, such as vapor
controls, are required. When concentrations decrease below the SSG IC compliance levels through natural
66
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
attenuation, or sampling has shown that vapor intrusion no longer poses an unacceptable risk, ECs may no
longer be necessary. EPA, in consultation with DTSC and the Central Valley Water Board, set these
cleanup levels and other action levels (IC compliance levels and water quality protection levels) to protect
human health and surface water quality. While the FOSET #2 Group 2 Action Sites ROD does not address
cleanup of groundwater, it is expected that these action levels will also protect groundwater quality beneath
the FOSET #2 Group 2 Action Sites.
67
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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68
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Table 2-3 Cleanup Levels - FOSET #2 Group 2 Action Sites
('(>(¦
I n restrict oil I so Cleanup Lc\cls
Industrial I se Cleanup l.e\els (m<>/k<>)
loot b»s
Basis lor Cleanup
1-15 loot b»s
Basis lor Cleanup
loot b»s
Basis lor Cleanup
1-15 feel b»s
Basis lor Cleanup
Inorganics
Arsenicb
12
Background
12
Background
12
Background
12
Background
Barium
3,200
Protection of surface water
6,900
Protection of human health
3,200
Protection of surface water
7,800
Protection of groundwater
Beryllium
15
Protection of human health
15
Protection of human health
130
Protection of surface water
360
Protection of groundwater
Cadmium
4.1
Surface soil background
6.2
Protection of human health
4.1
Surface soil background
96
Protection of groundwater
Cobalt
16
Surface soil background
18
Subsurface soil background
270
Protection of human health
270
Protection of human health
Chromium
1,600
Protection of surface water
2,600
Protection of human health
1,600
Protection of surface water
5,500
Protection of human health
Lead
140
Surface soil background
80
Protection of human health
140
Surface soil background
320
Protection of human health
Manganese
830
Protection of human health
830
Protection of human health
1,600
Protection of surface water
22,000
Protection of human health
Molybdenum
170
Protection of human health
170
Protection of human health
320
Protection of surface water
1,000
Protection of groundwater
Nickel
430
Protection of human health
430
Protection of human health
770
Protection of surface water
5,800
Protection of groundwater
Selenium
110
Protection of human health
110
Protection of human health
160
Protection of surface water
4,600
Protection of human health
Silver
23
Protection of surface water
170
Protection of human health
23
Protection of surface water
3,500
Protection of groundwater
Thallium
2.3
Protection of human health
2.3
Protection of human health
54
Protection of surface water
61
Protection of human health
Vanadium
170
Protection of human health
170
Protection of human health
1,600
Protection of surface water
4,600
Protection of human health
Zinc
1,700
Protection of surface water
3,100
Protection of human health
1,700
Protection of surface water
140,000
Protection of groundwater
SVOCs
2-Methylnaphthalene
16
Protection of human health
16
Protection of human health
170
Protection of human health
170
Protection of human health
1,4-Dichlorobenzene
1.1
Protection of human health
1.1
Protection of human health
4.5
Protection of human health
4.5
Protection of human health
2,4-Dinitrotoluene
0.0063
Protection of human health
0.0063
Protection of human health
1.6
Protection of surface water
2.5
Protection of groundwater
Benzo(a)anthracene
0.088
Protection of human health
0.088
Protection of human health
0.14
Protection of surface water
0.88
Protection of human health
69
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
COC
I n restrict oil I so (le;inup Lc\cls (in *»/k«)
liuliistriiil I se(le;inup l.exels (m»/k»)
tM loot b»s
liiisis lor Cleitnup
1-15 lee I b»s
liiisis lor C'k';inii|)
tM loot b»s
liiisis lor C'k'iinii|)
1-15 loot b»s
linsis lor C'k'iinii|)
Benzo(a)pyrene
0.018
Protection of human health
0.018
Protection of human health
0.14
Protection of surface water
and human health
0.14
Protection of human health
Benzo(b)fluoranthene
0.11
Protection of human health
0.11
Protection of human health
0.14
Protection of surface water
0.88
Protection of human health
Benzo(k)fluoranthene
0.11
Protection of human health
0.11
Protection of human health
0.14
Protection of surface water
0.88
Protection of human health
Chrysene
0.14
Protection of surface water
0.88
Protection of human health
0.14
Protection of surface water
8.7
Protection of human health
Dibenzo(a,h)anthracene
0.028
Protection of human health
0.028
Protection of human health
0.14
Protection of surface water
0.26
Protection of human health
Dieldrin
0.0045
Protection of surface water
0.0058
Protection of human health
0.0045
Protection of surface water
0.11
Protection of human health
Dioxins/Furans
4.2E-07
Protection of surface water
1.3E-06
Protection of human health
4.2E-07
Protection of surface water
1.6E-05
Protection of human health
Indeno( 1,2,3 -c,d)pyrene
0.12
Protection of human health
0.12
Protection of human health
0.14
Protection of surface water
0.88
Protection of human health
Naphthalene
2.4
Protection of human health
2.4
Protection of human health
5.1
Protection of human health
5.1
Protection of human health
PCBs
(Aroclor-1254 and
Aroclor-1260)
0.063
Protection of human health
0.063
Protection of human health
0.17 a
Protection of surface water
0.53
Protection of human health
lot ill Petroleum
1 lulrociirbons
loot b»s
liiisis lor C Ionnup
1-15 loot b»s
linsis lor C'loiiniii)
loot b»s
linsis lor C'k'iinii|)
1-15 loot b»s
liiisis lor C 'loiimip
TPH-D
3,200
Protection of surface water
3,900
Protection of groundwater
3,200
Protection of surface water
3,900
Protection of groundwater
TPH-G
160
Protection of surface water
220
Protection of groundwater
160
Protection of surface water
220
Protection of groundwater
Notes: Values for protection of human health, used as the basis for cleanup for non-VOCs and VOCs, are equivalent to the lesser of the carcinogenic risk of 1E-06 or a Hazard Quotient (HQ) 1 for each contaminant for exposure to soil through direct contact,
inhalation, and ingestion for the industrial use scenario.
a The industrial use cleanup level for PCBs was revised from 0.53 mg/kg to 0.17 mg/kg, based on an EPA Memo to File by Valerie Walker dated March 16, 2017 (EPA, 2017b). The screening level for protection of surface water for total PCBs is based
on 25% of the high TRV for benthic invertebrates.
b The cleanup level for arsenic is based on the revised background threshold value and risk management action level for arsenic (95% UTL with 99% coverage).
COC contaminant of concern
bgs below ground surface
mg/kg milligrams per kilogram
PCBs polychlorinated biphenyls
SVOC semi-volatile organic compound
TPH-D Total petroleum hydrocarbons as diesel
TPH-G Total petroleum hydrocarbons as gasoline
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Table 2-4 Levels for Protection of Surface Water and Groundwater Quality
Protection of Surface Water
Protection of (irounclwater
Lcm'Is •'
l.cxcls ;|
Contaminantb
0 to 1 foot bgs
0 to 15 feet bgs
Inorganics (mg/kg)
Aluminum
15,000 d
84,000
Arsenic f
12 d
12 d
Barium
3,200
7,800
Beryllium
130
360
Cadmium
4.1 d
96
Chromium
1,600
81,000
Cobalt
1,600
47,000
Lead
140 d
4,300
Manganese c
1,600
28,000
Molybdenum
320
1,000
Nickel
770
5,800
Selenium
160
5,800
Silver
23
3,500
Thallium
54
140
Vanadium
1,600
13,000
Zinc
1,700
140,000
SVOCs (mg/kg)
1,4-Dichlorobenzene
160
14
2-Methylnaphthalene c
—
170
2,3,7,8-TCDD
(dioxins/fiirans, total
TEQ)
0.00000042
0.0027
Benzo(a)anthracene
0.14
17
Benzo(a)pyrene
0.14
17
Benzo(b)fluoranthene
0.14
22
Benzo(k)fluoranthene
0.14
9.8
Chrysene
0.14
18
Dibenzo(a,h)anthracene
0.14
8.3
Dieldrin
0.0045
0.11
Indeno(l,2,3-cd)pyrene
0.14
11
Naphthalene
670
1,100
PCBs (Aroclor-1254,
Aroclor-1260)e
0.17
540
TPH (mg/kg)
TPH-D
3,200
3,900
TPH-G
160
220
Notes: a) The values contained in this table are for use in determining whether ECs are necessary for the
protection of groundwater and surface water quality.
b) The source of the levels for protection of groundwater and surface water is Table 80 of the FOSS ROD,
unless otherwise noted.
c) The source of the levels for protection of groundwater and surface water is Table Cl-19 of the FOSS
RICS because the contaminant was not included in Table 80 of the FOSS ROD.
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d) The background value is higher than the levels for protection of groundwater and surface water, so the
background value has been included in place of the values specified in Table 80 of the FOSS ROD or Table
Cl-19 of the FOSS RICS.
e) The screening level for protection of surface water for total PCBs is based on 25% of the high TRV for
benthic invertebrates.
f) The cleanup levels for arsenic are based on the recently revised background threshold value and risk
management action level for arsenic (95% UTL with 99% coverage).
no protection level was developed
bgs below ground surface
EC engineered control
FOSS Follow-on Strategic Sites
IC institutional control
mg/kg milligrams per kilogram
PCBs polychlorinated biphenyls
RICS Remedial Investigation Characterization Summary
ROD Record of Decision
SVOCs semi-volatile organic compounds
TCDD tetrachlorodibenzo-p-dioxin
TPH total petroleum hydrocarbons
TPH-D total petroleum hydrocarbons as diesel
TPH-G total petroleum hydrocarbons as gasoline
TRV toxicity reference value
UTL upper tolerance level
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Table 2-5 Shallow Soil Gas Institutional Control Compliance Levels
('(>(¦
Commercial/
Industrial IC
Compliance l.e\el
Depth
Basis lor Cleanup
Volatile Organic Compounds (VOCs) (ppbv)
1,1-DCA
63
0 to 15 feet
Protection of human health
1,1,2,2-PCA
1.0
0 to 15 feet
Protection of human health
1,2-DCB
4,900
0 to 15 feet
Protection of human health
1,2-DCA
3.9
0 to 15 feet
Protection of human health
1,2,4-TMB
1,800
0 to 15 feet
Protection of human health
1,3-butadiene
1.1
0 to 15 feet
Protection of human health
1,3-DCB
2,700
0 to 15 feet
Protection of human health
1,3,5-TMB
1,800
0 to 15 feet
Protection of human health
1,4-DCB
6.1
0 to 15 feet
Protection of human health
2-Methylnaphthalene
400
0 to 15 feet
Protection of human health
Benzene
4.4
0 to 15 feet
Protection of human health
Carbon tetrachloride
1.6
0 to 15 feet
Protection of human health
Chloroform
3.6
0 to 15 feet
Protection of human health
cis-l,2-DCE
290
0 to 15 feet
Protection of human health
Ethylbenzene
38
0 to 15 feet
Protection of human health
Hexachlorobutadiene
1.8
0 to 15 feet
Protection of human health
Hexane
29,000
0 to 15 feet
Protection of human health
Methylene chloride
120
0 to 15 feet
Protection of human health
m,p-xylene
3,400
0 to 15 feet
Protection of human health
Naphthalene
2.3
0 to 15 feet
Protection of human health
o-xylene
3,400
0 to 15 feet
Protection of human health
PCE
9.9
0 to 15 feet
Protection of human health
TCE
19
0 to 15 feet
Protection of human health
Vinyl chloride
2.1
0 to 15 feet
Protection of human health
Notes: Values for protection of human health are equivalent to the lesser of the carcinogenic risk of 1 x io 6 or an
HQ of 1 for each contaminant for exposure to soil gas through indoor air inhalation for the industrial use
scenario based on current EPA and DTSC understanding of toxicity. EPA's IRIS levels are the default
standard unless DTSC's HERO levels are three times more stringent than federal levels. These values are
used as the basis for institutional controls for VOCs and were not used as the basis for risk assessments in
the Remedial Investigations (RIs)..
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coc
contaminant of concern
DCA
dichloroethane
DCB
dichlorobenzene
DCE
dichloroethene
IC
institutional control
PCA
tetrachloroethane
PCE
tetrachloroethene
ppbv
parts per billion by volume
TCE
trichloroethene
TMB
trimethylbenzene
voc
volatile organic compound
2.9 DESCRIPTION OF ALTERNATIVES
Representative process options were screened and assembled into nine remedial alternatives that address a
broad range of site conditions and contaminant types. Under some alternatives, contaminants will be
removed to reduce the risk such that the sites are available for unrestricted land use. Under alternatives
requiring ECs or ICs, sites will be available for limited use (referred to as restricted or industrial land use).
Because the types (e.g., VOCs versus non-VOCs) and mix of contamination vary by site, not all of the
alternatives were evaluated for every site. The eight evaluated alternatives are as follows:
• Alternative 1 - No Further Action. CERCLA and the NCP require the evaluation of a No Further
Action alternative to establish a basis for comparison with other alternatives. No remedial activities
for VOCs or non-VOCs are implemented under this alternative. No cost is associated with this
alternative. The No Further Action alternative does not reduce risk to human health or the
environment.
• Alternative VOC2 - Institutional Controls to Prohibit Residential Use (Restricted Land Use).
ICs would be used under this alternative to eliminate or limit exposure pathways to humans where
site contamination levels in SSGs would not allow for unrestricted land use. This alternative would
restrict land use such that the property may not be used for sensitive uses such as homes, day care
centers, health care centers, or public or private schools for persons under 18 years of age within
the contaminated portion of the property.
• Alternative VOC3 - Institutional Controls to Prohibit Residential Use and Engineered
Controls to Mitigate Shallow Soil Gas Contamination (Restricted Land Use). Under this
alternative, land use activity restrictions would be used to reduce the potential for human exposure
from VOCs in SSG migrating into buildings and impacting occupants via the vapor inhalation
pathway. This alternative would restrict land use such that the property may not be used for
sensitive uses as described for Alternative VOC2. In addition, the selected restrictions under
Alternative VOC3 would require the installation of ECs (such as vapor barriers, gas collection
systems, and/or ventilation systems) in any future buildings or during significant remodeling of
existing buildings (e.g., remodeling that requires replacing major portions of the foundation or
floor), unless sampling indicates that the IC compliance levels in Table 2-5 are not exceeded.
• Alternative VOC4 - Soil Vapor Extraction and Institutional Controls to Restrict Land Use.
SVE is a process that applies a vacuum to subsurface soil (via extraction wells) to extract
contaminated vapors from the soil and flush fresh air through the contaminated soil. As necessary,
the extracted vapors are treated to reduce emissions to the air to acceptable levels. Under
Alternative VOC4, existing SVE systems (operating under the former McClellan AFB SVE
Program) would continue to operate at sites containing VOCs in SSG to mitigate the vapor
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inhalation pathway. If necessary, additional shallow extraction or monitoring wells would be
installed to enhance the existing SVE systems, as the existing SVE systems are operated for the
sole protection of groundwater and are not intended to remediate SSG contamination. In addition,
this alternative would use ICs to restrict land use such that the property may not be used for sensitive
uses as described for Alternative VOC2 and would require the installation of ECs until the IC
compliance levels are reached as described for Alternative VOC3.
• Alternative Non-VOC2 - Institutional Controls to Restrict Land Use, Engineered Controls,
and Monitoring. Under this alternative, ICs, ECs, and/or monitoring would be used to eliminate
or limit exposure pathways for non-VOCs to human receptors and the environment. The specific
type of controls and/or monitoring required for a particular site would depend on the specific
characteristics of each site such as the type of contaminants, how people might come in contact
with the contaminants, the risk associated with the contaminants, and whether the contaminants
could migrate offsite. Monitoring would be implemented in conjunction with, and in support of,
other remedies such as ICs and ECs. The monitoring would be used to show that the remedy
protects human health and the environment.
• Alternative Non-VOC3 - Bioventing and Institutional Controls to Restrict Land Use.
Bioventing is typically used for sites with fuel-related contamination. This alternative involves
pumping oxygen to contaminated soils through the extraction and/or injection of air. As necessary,
the extracted vapors are treated to reduce emissions to the air to acceptable levels. The increased
oxygen within the subsurface supports naturally-occurring microorganisms within the soil to
biodegrade the contamination. Because the contamination would be treated in place, ICs and
monitoring similar to those described for Alternative Non-VOC2 would be required under
Alternative Non-VOC3. Once treatment was completed, the ICs and monitoring requirements
could be eliminated if unrestricted land use cleanup levels were achieved. Based on previous
bioventing systems that have been installed at McClellan Park, it is estimated that it would take
several years for bioventing to achieve RAOs.
• Alternative Non-VOC4a - Excavation and Disposal and Institutional Controls to Restrict
Land Use (Restricted Land Use). Under this alternative, soil that is contaminated at levels above
industrial use cleanup levels would be excavated and transported off-site for disposal at an
appropriate facility. Because some residual contamination would remain at the site, ICs and ECs
would be used to eliminate or limit exposure pathways for non-VOCs to human receptors and the
environment. The site would be restricted to industrial or commercial use. Sensitive uses such as
residential use, public or private schools for persons under 18 years of age, and/or day care centers
would be prohibited. For sites where residual contamination could impact surface water, ECs (such
as maintaining a surface cover or sediment collection and monitoring) would be required to protect
surface water. Alternatively, if the existing cover is removed and there is a potential impact to
surface water quality, sampling must be done to determine if a surface cover or sediment trap and
sediment monitoring are required. Monitoring would be implemented in conjunction with, and in
support of, other remedies such as ICs and ECs. Based on previous excavation activities at the
former McClellan AFB, it is estimated that most excavations could be planned and executed within
6 months to 1 year.
• Alternative Non-VOC4b - Excavation and Disposal (Unrestricted Land Use). Under this
alternative, soil that is contaminated at levels above unrestricted use cleanup levels would be
excavated and transported off-site for disposal at an appropriate facility. Because all contamination
above unrestricted use cleanup levels would physically be removed from the site, no ICs or long-
term monitoring would be required. Alternative Non-VOC4b would facilitate unrestricted use of
the site, including residential use, public or private schools for persons under 18 years of age, and/or
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
day care centers. Based on previous excavation activities at the former McClellan AFB, it is
estimated that most excavations could be planned and executed within 6 months to 1 year.
Alternative VOC4 (SVE) was evaluated for CS P-006, CS S-021, CS S-027, CS T-037, PRL L-003 (F2),
PRL L-004, PRL L-005 (F2), PRL P-004, SA 079, SA 081, and SA 102 because these sites are within or
are anticipated to be within the radius of influence of an SVE system that will continue to operate; however,
Alternative VOC4 was determined to be not technically feasible, effective in the short- or long-term, or
cost effective due to the fact that soil gas contamination is widely distributed and that SVE may not be able
to reduce SSG concentrations to levels that are protective of indoor air. Alternative Non-VOC3
(Bioventing) was only evaluated for sites with TPH contamination, including AOC 325, PRL S-022 & SA
069, PRL L-004, PRL T-019, SA 038, and SA 081; however, Alternative Non-VOC3 was determined to
be more difficult to implement than excavation and is more expensive than excavation. In addition, the
timeframe required to achieve cleanup levels and the effectiveness are uncertain for Alternative Non-
VOC3. Lastly, Alternative Non-VOC3 would not address other types of soil contaminants that are present,
such as metals and PCBs. Alternative VOC4 (SVE), Alternative Non-VOC3 (Bioventing), and Alternative
Non-VOC4b (Excavation and Disposal [Unrestricted Land Use]) were not selected and are not discussed
further in this ROD. Alternative 1 (No Further Action) was not selected for any of the Group 2 Action
Sites; however, this alternative is discussed in Table 2-6 as a baseline for comparative analysis purposes.
Alternative VOC2 (Institutional Controls to Prohibit Residential Use [Restricted Land Use]), Alternative
VOC3 (Institutional Controls Prohibit Residential Use and Engineered Controls to Mitigate Shallow Soil
Gas Contamination [Restricted Land Use]), Alternative Non-VOC2 (Institutional Controls to Restrict Land
Use, Engineered Controls, and Monitoring), and Alternative Non-VOC4a (Excavation and Disposal
[Restricted Land Use]) were selected for one or more sites. Please see Table 1-2 for a summary of the
alternative(s) selected for each site.
2.9.1 Common Elements and Distinguishing Features of Each Alternative
These alternatives include common elements, as well as distinguishing features unique to each option. The
following discussion summarizes the common elements and distinguishing features of the alternatives. As
previously noted, not all of the alternatives were evaluated for every site.
2.9.1.1 Common Elements
Common elements for the alternatives are as follows:
• All of the alternatives, except for Alternatives 1 (No Further Action) and 8 (excavation to
unrestricted use), result in restricted (i.e., limited or industrial) land use and include ICs.
• Alternatives VOC2, VOC3, Non-VOC2, and Non-VOC4a require monitoring of the ICs.
Alternatives Non-VOC2 and Non-VOC4a may also require sediment monitoring. Contamination
left in place triggers ARARs for ICs and, in cases with potential impacts to surface water or
groundwater, ARARs for monitoring requirements.
• All of the alternatives, except for Alternative 1 for sites with unacceptable risks, are compatible
with intended site reuse.
• All of the alternatives, except for Alternative 1, are expected to be completed and facilitate reuse
within less than one year to three years.
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
2.9.1.2 Distinguishing Features
The distinguishing features of Alternative 1 are that no remedial action would take place under this
alternative and that there is no cost associated with this alternative.
ECs (e.g., surface cover and sediment collection systems) are a distinguishing feature of Alternatives
VOC3, Non-VOC2, and Non-VOC4a. Under Alternative VOC3, vapor controls (e.g., vapor barrier, gas
collection, or ventilation) would prevent worker exposure to soil gas and support the overall protectiveness
of the remedy. It is expected that ECs (e.g., vapor barrier, gas collection, or ventilation) could be designed,
planned, and installed within 6 months to 1 year. Under Alternatives Non-VOC2 and Non-VOC4a, surface
cover (e.g., asphalt, concrete, or building foundations) would provide a physical barrier to prevent direct
contact with contaminated soil and prevent erosion and associated impacts to surface water. Sediment
collection systems would also prevent direct contact and surface water impacts because contaminated
sediment would be collected and removed. These will support the overall protectiveness of the remedy. It
is expected that ECs (e.g., surface cover or sediment collection systems) could be designed, planned, and
installed within six months to one year.
The distinguishing feature of Alternative Non-VOC4a is excavation and disposal of excavated wastes. The
long-term reliability of these alternatives is high because the waste is removed from the site and placed into
an appropriate facility. Excavation of large volumes is expensive; therefore this remedy is used sparingly.
It is expected that most excavations under Alternative Non-VOC4a could be planned and executed within
six months to one year.
2.10 SUMMARY OF COMPARATIVE ANALYSIS OF REMEDY ALTERNATIVES
In accordance with the NCP (Section 300.430(f)(5)(i)), the remedial alternatives were evaluated against the
following nine criteria:
• Criterion 1: Overall Protection of Human Health and the Environment - This criterion
addresses whether each alternative provides adequate protection of human health and the
environment and describes how risks posed through each exposure pathway are eliminated,
reduced, or controlled, through treatment, ECs, and/or ICs. In every ROD, a "no action" alternative
is considered as a baseline for comparative analysis purposes. In cases where the no action
alternative is found to not meet this criterion, it is ruled out for further consideration and therefore,
need not be discussed further in the nine criteria analysis.
• Criterion 2: Compliance with ARARs - This criterion addresses whether each alternative
complies with federal and state requirements that are applicable or relevant and appropriate to the
remedial action. Section 121(d) of CERCLA and NCP 300.430(f)(l)(ii)(B) require that remedial
actions at CERCLA sites attain ARARs, unless such ARARs are waived under CERCLA Section
121(d)4. For an alternative to pass into the detailed analysis stage and thus become eligible for
selection it must comply with its ARARs or a waiver should be identified and the justification
provided for invoking it. An alternative that cannot comply with ARARs or for which a waiver
cannot be justified, is eliminated from consideration for further discussion as a potential alternative
in the Proposed Plan or ROD.
• Criterion 3: Long-term Effectiveness and Permanence - Long-term effectiveness and
permanence refers to expected residual risk and the ability of a remedy to maintain reliable
protection of human health and the environment over time, once cleanup levels have been met.
This criterion includes the consideration of residual risk that will remain onsite following
remediation and the adequacy and reliability of controls. Long-term effectiveness and permanence
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
of an alternative are viewed along a continuum (i.e., an alternative can offer a greater or lesser
degree of long-term effectiveness and permanence). Alternatives that are more effective in the long
term are more permanent.
• Criterion 4: Reduction of Toxicity, Mobility, or Volume through Treatment - Reduction of
toxicity, mobility, or volume through treatment refers to the anticipated performance of the
treatment technologies that may be included as part of a remedy. Each characteristic is analyzed
independently and collectively to determine how effectively treatment is being employed by the
remedial alternative. In addition, other elements such as the risks posed by residuals are considered.
• Criterion 5: Short-term Effectiveness - Short-term effectiveness considers the amount of time
until the remedy effectively protects human health and the environment at the site. It also includes
an evaluation of the adverse effects the remedy may pose to workers, the community, and the
environment during implementation. Possible adverse effects should be evaluated in advance to
determine mitigative steps to adequately minimize the impact to workers, the community, or the
environment and to minimize any risks that would remain at the site.
• Criterion 6: Implementability - Implementability considers the ease of implementing the remedy
in terms of construction and operation, and the availability of services and materials required to
implement the alternative. Technical consideration also includes the reliability of the technology,
the effect on future remedial action options, and monitoring at the site. Variables such as the site's
topography, location, and available space are considered. Implementability is significant when
evaluating treatment technologies that are dependent on resources such as facilities, equipment,
professionals or experts, and especially technologies that have not been proven effective. In
addition, administrative feasibility, which includes activities that need to be coordinated with other
offices and agencies, is addressed when analyzing this criterion.
• Criterion 7: Cost - The cost of an alternative addresses all engineering, construction, and O&M
costs incurred over the life of the project. The assessment against this criterion is based on the
estimated present worth of these costs for each alternative. Present worth is used to estimate
expenditures that occur over different lengths of time. The costs of remedies always are qualified
as estimates with an expected accuracy of +50% to -30%.
• Criterion 8: State Acceptance - This assessment evaluates the technical and administrative issues,
concerns, and preferences the State agencies may have regarding each of the alternatives. Resource
agencies have reviewed the site documents and have agreed with the selected remedies. Major
support agency comments must be summarized under this criterion and the lead agency's response
to those comments are also summarized.
• Criterion 9: Community Acceptance - This assessment evaluates the issues, concerns, and
preferences the public may have regarding each of the alternatives. Because information available
on the community acceptance criterion may be limited before the public comment period for the
Proposed Plan, this factor is fully evaluated in the ROD.
The nine criteria are categorized as threshold criteria, primary balancing criteria, or modifying criteria.
Threshold criteria are requirements that each alternative must meet to be eligible for selection as the
preferred alternative. The threshold criteria are 1 and 2 - overall protection of human health and the
environment and compliance with ARARs. Primary balancing criteria are used to weigh effectiveness and
cost tradeoffs among alternatives. They are the main technical criteria upon which the alternative evaluation
is based. The balancing criteria are 3 through 7 - long-term effectiveness and permanence; reduction of
toxicity, mobility, or volume through treatment; short-term effectiveness; implementability; and cost.
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Modifying criteria may be used to modify aspects of the preferred alternative when preparing this ROD.
The modifying criteria are 8 and 9 - State acceptance and community acceptance.
The comparative analysis of alternatives based on the threshold and balancing criteria is summarized in
Table 2-6. Site-specific details were considered when comparing the performance of each alternative. Not
all of the alternatives are evaluated for each site because not all alternatives are appropriate at every site.
2.10.1 VOC Alternatives
In the FS documents (CH2MHill, 2011 and 2012), the VOC alternatives were evaluated at the Group 2
Action Sites for which COCs for SSG have been identified or sites where insufficient SSG data is available.
Each of these sites was evaluated for Alternative 1 and Alternative VOC2. Additionally, due to risks (or
potential risks) associated with SSG within, or greater than, the risk management range (1 x 10"4 to 1 x 10"
6 carcinogenic risk) for restricted use, Alternative VOC3 was evaluated. Of the 45 Group 2 Action Sites 43
were evaluated for VOC alternatives.
The overall ranking of VOC alternatives varies by site upon consideration of numerous factors within the
balancing criteria, including the level of existing risk to human health, current and future land use, and
incremental cost (i.e., the cost difference between alternatives). In general, Alternative VOC3 is most often
the highest ranking (i.e., most preferable) alternative because it is the most protective and is typically not
significantly more expensive. For sites with commercial/industrial risks below the risk management range,
the additional cost and restrictions for Alternative VOC3 may not be justified and Alternative VOC2 may
be preferable.
There are no actions associated with Alternative 1. Therefore, there are no technical impediments to
implementing Alternative 1. For Alternatives VOC2 and VOC3, land reuse might be constrained by the
ICs and risk of future exposure might exist if monitoring is insufficient to detect failure of an IC. Significant
coordination will be required between AFCEC, Sacramento County, DTSC, and the Central Valley Water
Board for these alternatives to be successful. The ECs associated with Alternative VOC3 will be readily
implementable, and vendors are readily available. Installing a vapor barrier and gas collection system in
an occupied building will require coordination with current tenants.
A summary of the comparative analysis of alternatives for these sites from the FSs is presented in Table 2-
6.
2.10.2 Non-VOC Alternatives
In the FS documents (CH2MHill, 2011 and 2012), the non-VOC alternatives were evaluated at 26 of 45
FOSET #2 Group 2 Action Sites. Only two non-VOC alternatives (i.e., Alternatives Non-VOC2 and Non-
VOC4a) were selected for the FOSET #2 Group 2 Action Sites.
The overall ranking of non-VOC alternatives varies by site upon consideration of numerous factors within
the balancing criteria, including the level of existing risk to human health, the types of contaminants present,
the potential for impacts to water quality, the potential for direct or indirect impacts to nearby wetlands,
current and future land use, and incremental cost (i.e., the cost difference between alternatives).
In general, ICs/ECs (Alternative Non-VOC2) are more preferable because they are typically more cost
effective and are still protective of both human health and of surface water quality. Alternative Non-VOC2
was selected for 21 of the FOSET #2 Group 2 Action Sites, while Alternative Non-VOC4a was selected
for four of the FOSET #2 Group 2 Action Sites. Between Alternatives Non-VOC2 and Non-VOC4a,
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Alternative Non-VOC4a has the advantage of physically removing contaminated soil, but in many cases
there are significantly higher costs for excavation/disposal.
There are no actions associated with Alternative 1. Therefore, there are no technical impediments to
implementing Alternative 1. For Alternatives Non-VOC2 and Non-VOC4a, land reuse might be restricted
by the ICs, and risk of future exposure might exist if monitoring is insufficient to detect failure of an IC.
Significant coordination will be required between AFCEC, Sacramento County, DTSC, and the Central
Valley Water Board for these alternatives to be successful. The ECs will be readily implementable, and
vendors are readily available. For Alternative Non-VOC4a, excavation with accompanying equipment are
readily implementable, technically feasible, and reliable; however, it will be subject to potential capacity
limitations regarding the amount of waste received at an offsite landfill at one time. At many sites, these
alternatives need to be implemented along with another alternative to address VOCs in shallow soil gas.
A summary of the comparative analysis of alternatives for these sites from the two FSs is presented in Table
2-6.
80
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Table 2-6 Comparative Analysis of Both VOC and Non-VOC Alternatives
Silo
Protection of 11 iiin:in Health itncl the
Kn\ironmenl
Compliance
with ARARs
Long-term LITectness and Performance
Reduction in Toxicity,
Mobility, and Volume
Through Treatment
Short-term LITcctncness
Implementahility
C'OSI (I'V.tn)
AOC 325
VOC alternate es:
VOC3 would be protective for future use
if a new building is constructed;
however, both VOC2 and VOC3 would
prohibit unrestricted use.
NFA for SSG would not be protective
considering the HI is greater than 1 for
the unrestricted use scenario.
Non-VOC alternatives:
Non-VOC4a and Non-VOC4b would be
protective because TPH would be
physically removed. Non-VOC3 would
be protective. Non-VOC2 with ECs
(e.g., maintaining surface cover) would
be protective of human health and
surface water.
NFA for soil would be protective of human
health but potential impacts to water
quality would remain. NFA would also not
require maintaining surface cover and
would therefore not be protective of
surface water quality.
VOC
alternatives:
VOC2 and
VOC3 would
comply with
ARARs.
Non-VOC
alternatives:
Non-VOC2,
Non-VOC3,
Non-VOC4a
and Non-
VOC4b
would comply
with ARARs.
VOC alternate es:
Risks are within the risk management range for unrestricted use and at the
low end of the risk management range for industrial use. The HI is greater
than 1 for the unrestricted use scenario. Risks under VOC3 would be
acceptable. Risks under VOC2 would be acceptable. Risks under NFA
would not be acceptable.
The long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would depend on the maintenance, monitoring, and enforcement of
the ICs. The criterion for long-term effectiveness and permanence would
not be met under NFA.
Non-VOC alternatives:
Current risks (without arsenic) are at the low end of the risk management
range for unrestricted use and less than the risk management range for
industrial use. TPH-D and TPH-G were detected at maximum
concentrations of 2,680 mg/kg, and 351 mg/kg, respectively, which
exceed levels for the protection of groundwater and surface water.
Non-VOC4b would be the most effective and permanent because levels
acceptable for unrestricted use would be achieved by excavation and offsite
disposal. Under Non-VOC4a, levels acceptable for industrial use would be
achieved. Under Non-VOC4a, Non-VOC3, and Non-VOC2, residual
contamination would remain; however, ICs and ECs would provide
continued protection of human health and water quality. The long-term
effectiveness and permanence of Non-VOC3 would be increased relative to
Non-VOC2 with the addition of bioventing. The long-term effectiveness and
permanence of the ICs under Non-VOC2 would depend on the maintenance,
monitoring, and enforcement of the ICs. The criterion for long-term
effectiveness and permanence would not be met under NFA.
VOC alternatives:
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
Non-VOC alternatives:
Toxicity, mobility, and
volume would be
reduced at the site by
bioventing under Non-
VOC3. Only Non-VOC3
would meet the statutory
preference for treatment.
NFA, Non-VOC2, Non-
VOC4a, and Non-
VOC4b do not meet the
statutory preference for
treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3 may
involve limited disruption of shallow
soils.
For Non-VOC alternatives:
NFA and Non-VOC2 would require
the least amount of time to
implement, and contaminated soil
would not be disturbed.
Implementation of Non-VOC2
would entail no significant adverse
risks to the environment or health
of the community and workers.
Non-VOC3 would require the
installation of the bioventing
system which could likely be
accomplished in a relatively short
period of time. However, the
bioventing system would likely
require many months to years of
operation before RAOs could be
achieved. Short-term risks during
bioventing (Non-VOC3) and
excavation (Non-VOC4a and Non-
VOC4b) could be managed
VOC alternatives:
NFA, VOC2, and
VOC3 are
implementable.
For Non-VOC
alternatives:
NFA, Non-VOC2, and
Non- VOC3 are
implementable.
Excavation (Non-VOC4a
and Non-VOC4b) may be
more difficult to
implement because
contamination likely
extends to 30 feet bgs.
Current site use would be
disrupted during
bioventing (Non-VOC3)
and excavation (Non-
VOC4a and Non-VOC4b).
VOC alternate es:
VOC2 = $98,300
VOC3 = $206,300
Non-VOC alternatives:
Non-VOC2 = $193,000
Non-VOC3 = $651,000
Non-VOC4a = $265,000
Non-VOC4b = $185,000
81
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiince
with ARARs
Long-term LITectncss ;iikI IViToriiiiiiuc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llroni>h Trciilmcnt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
CS P-005
VOC alternatives:
V0C3 would be protective but V0C2
would effectively prevent unrestricted
use.
NFA would not be protective considering
the HI is greater than 1 for the
unrestricted use scenario.
Non-VOC alternatives:
Risk for soils are within the risk
management range for unrestricted use;
however, there are potential impacts to
surface water quality. Non-VOC4a would
be protective because contaminants
would be physically removed. Non-
V0C2 withECs (e.g., maintaining
surface cover) would be protective of
surface water quality.
NFA would not be protective of surface
water quality.
VOC
alternatives:
V0C2 and
V0C3 comply
with ARARs
Non-VOC
alternatives:
Non-VOC2 and
Non-VOC4a
would comply
with ARARs.
VOC alternatives:
Risks under V0C2 and V0C3 would be acceptable. Risks for unrestricted
use are within the risk management range and for industrial use are below
the risk management range; however, the HI is greater than 1 for the
unrestricted use scenario. NFA would not be protective considering the HI
is greater than 1 for the unrestricted use scenario.
The long-term effectiveness and permanence of the ICs under V0C2 and
V0C3 would be nearly equal; however, the long-term reliability and
permanence of V0C3 would be increased relative to V0C2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under V0C2 would
depend on the maintenance, monitoring, and enforcement of the ICs. The
criterion for long-term effectiveness and permanence would not be met
under NFA.
Non-VOC alternatives:
Risks under Non-VOC2 would be acceptable and would address protection
of surface water quality with ECs. Risks and hazard without arsenic are
within the risk management range for both unrestricted use and industrial
use. There are potential impacts to surface water quality. NFA would not
be protective of surface water quality.
Non-VOC4a would be effective and permanent given that post-excavation
soil sampling would be performed to verily that residual contamination
would not impact groundwater. The long-term effectiveness and
permanence of the ICs under Non-VOC2 would depend on the
maintenance, monitoring, and enforcement of the ICs and ECs. The
criterion for long-term effectiveness and permanence would not be met
under NFA.
VOC alternatives:
NFA, V0C2, and V0C3
do not meet the statutory
preference for treatment
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4a do not meet
the statutory preference
for treatment.
VOC alternatives:
NFA, V0C2, and V0C3 would be
effective immediately.
Implementation of V0C2 would
entail no significant adverse risks to
the environment or health of the
community and workers. V0C3
would involve limited disruption of
shallow soils.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately, and
contaminated soil would not be
disturbed. Implementation of Non-
V0C2 would entail no significant
adverse risks to the environment or
health of the community and
workers. Short-term risks during
excavation (Non-VOC4a) could be
managed.
VOC alternatives:
NFA, V0C2, and V0C3
are implementable.
Coordination with the
SVE program would be
required.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4a are
implementable. Current
site use would be disrupted
during excavation (Non-
V0C4a).
VOC alternatives:
V0C2 = $108,600
VOC3 = $536,600
Non-VOC alternatives:
Non-VOC2 = $88,000
Non-VOC4ab =
$507,800
82
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiince
with ARARs
Long-term LITectncss ;iikI IVrforniiiiuc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llroni>h Trciilmcnt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
CS P-006
VOC alternatives:
V0C4 would be protective because
volume and concentrations of VOCs
would be reduced. V0C3 would provide
additional protection compared to V0C2.
V0C2 would effectively prevent
unrestricted use.
NFA would not be protective considering
the risk for unrestricted use is greater than
the risk management range and the HI is
greater than 1 for the unrestricted use
scenario.
Non-VOC alternatives:
Risk in soils is greater than the risk range
for unrestricted use, and Non-VOC2 with
ECs (e.g., maintaining surface cover)
would effectively prevent unrestricted use
and would be protective of surface water
quality.
NFA would not be protective considering
the risk for unrestricted use is greater than
the risk management range and the HI is
greater than 1 for the unrestricted use
scenario. NFA would also not be protective
of groundwater and surface water quality.
VOC
alternatives:
V0C2, V0C3,
and V0C4
would comply
with ARARs.
Non-VOC
alternatives:
Non-VOC2
would comply
with ARARs.
VOC alternatives:
Risks under V0C2 would be acceptable. Risks under V0C4 and V0C3
would be acceptable. Risk for unrestricted use is greater than the risk
management range and the HI is greater than 1. Risk for industrial use is
within the risk management range. The long-term effectiveness and
permanence of the ICs under V0C2 would depend on the maintenance,
monitoring, and enforcement of the ICs. NFA would not be protective
considering the risk for unrestricted use is greater than the risk management
range and the HI is greater than 1 for the unrestricted use scenario.
The long-term effectiveness and permanence of the ICs under V0C2,
V0C3, and V0C4 would be nearly equal; however, the long-term
reliability and permanence of V0C4 would be increased relative to V0C3
with the addition of SVE, which would physically remove VOCs. The
long-term effectiveness and permanence of the ICs under V0C2 and
V0C3 would be nearly equal; however, the long-term reliability and
permanence of V0C3 would be increased relative to V0C2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under V0C2
would depend on the maintenance, monitoring, and enforcement of the
ICs. The criterion for long-term effectiveness and permanence would not
be met under NFA.
Non-VOC alternatives:
Risks under Non-VOC2 would be acceptable and would address protection
of surface water quality with ECs. Risks are greater than the risk
management range for unrestricted use and within the risk management
range for industrial use. There are also potential impacts to surface water
quality. NFA would not be protective considering the risk for unrestricted
use is greater than the risk management range and the HI is greater than 1
for the unrestricted use scenario. NFA would also not be protective of
groundwater and surface water quality.
The long-term effectiveness and permanence of the ICs and ECs under Non-
V0C2 would depend on the maintenance, monitoring, and enforcement of
the ICs and ECs. The criterion for long-term effectiveness and permanence
would not be met under NFA.
VOC alternatives:
Mobility and volume
would be significantly
reduced under V0C4.
NFA, V0C2, and V0C3
do not meet the statutory
preference for treatment.
Non-VOC alternatives:
NFA and Non-VOC2 do
not meet the statutory
preference for treatment.
VOC alternatives:
NFA, V0C2, and V0C3 would be
effective immediately; however,
there is uncertainty for V0C4
regarding the time required to
achieve industrial use PCGs.
Implementation of V0C2 would
entail no significant adverse risks to
the environment or health of the
community and workers. V0C3
would involve limited disruption of
shallow soils. V0C4 could require
installation of additional wells, but
short-term risks could be managed.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately, and
contaminated soil would not be
disturbed. Implementation of Non-
V0C2 would entail no significant
adverse risks to the environment or
health of the community and
workers.
VOC alternatives:
NFA, V0C2, V0C3, and
V0C4 are implementable.
Non-VOC alternatives:
NFA and Non-VOC2 is
implementable.
VOC alternatives:
V0C2 = $88,000
VOC3 = $196,000
VOC4 = $214,000
Non-VOC alternatives:
Non-VOC2 = $88,000
83
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of lliiinnn llciilth iinil the
Km iron moil t
('ompliiince
with ARARs
Long-term LITectncss ;iikI I'crforniiincc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llroni>h Trciilmcnt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
CS S-021
VOC alternatives:
V0C4 would be protective because
volume and concentrations of VOCs
would be reduced. V0C3 would provide
additional protection compared to V0C2.
V0C2 would effectively prevent
unrestricted use.
NFA would not be protective because the
risk for unrestricted use is at the upper end
of the risk management range and several
VOCs were detected above industrial
screening levels.
VOC
alternatives:
V0C2, V0C3,
and V0C4
would comply
with ARARs.
VOC alternatives:
Risks under V0C3 and V0C4 would be acceptable. Risks under V0C2
would be acceptable, however, given the number of VOCs detected above
industrial screening levels, V0C3 would better protect industrial users.
Risks are at the upper end of the risk management range for unrestricted use
and within the risk management range for industrial use. NFA would not be
protective given that the risk for unrestricted use is at the upper end of the
risk management range and that several VOCs were detected above
industrial screening levels.
The long-term effectiveness and permanence of the ICs under V0C2, V0C3,
and V0C4 would be nearly equal; however, the long-term reliability and
permanence of V0C4 would be increased relative to V0C3 with the addition
of SVE, which would physically remove VOCs. The long-term effectiveness
and permanence of the ICs under V0C2 and V0C3 would be nearly equal;
however, the long-term reliability and permanence of V0C3 would be
increased relative to V0C2 with the addition of ECs, which would control
migration of soil gas into indoor air. The long-term effectiveness and
permanence of the ICs under V0C2 would depend on the maintenance,
monitoring, and enforcement of the ICs. The criterion for long-term
effectiveness and permanence would not be met under NFA.
VOC alternatives:
Mobility and volume
would be significantly
reduced under V0C4.
V0C4 meets the statutory
preference for treatment,
but NFA, V0C2, and
V0C3 do not include
treatment.
VOC alternatives:
NFA, V0C2, and V0C3 would be
effective immediately; however,
there is uncertainty for V0C4
regarding the time required to
achieve industrial use PCGs.
Implementation of V0C2 would
entail no significant adverse risks to
the environment or health of the
community and workers. V0C3
would involve limited disruption of
shallow soils. V0C4 could require
installation of additional wells, but
short-term risks could be managed.
VOC alternatives:
NFA, V0C2, V0C3, and
V0C4 are implementable.
VOC alternatives:
V0C2 = $88,000
VOC3 = $576,000
VOC4 = $594,000
CS S-027
VOC alternatives:
V0C4 would be protective because
volume and concentrations of VOCs
would be reduced. V0C3 would provide
additional protection compared to V0C2.
V0C2 would effectively prevent
unrestricted use.
NFA would not be protective given that the
risk for unrestricted use is greater than the
risk management range and that several
VOCs were detected above industrial
screening levels.
VOC
alternatives:
V0C2, V0C3,
and V0C4
would comply
with ARARs.
VOC alternatives:
Risks under V0C3 and V0C4 would be acceptable. Risks under V0C2
would be acceptable, however, given the number of VOCs detected above
industrial screening levels, V0C3 would better protect industrial users.
Risks for unrestricted use are greater than the risk management range and
for industrial use are within the risk management range. NFA would not be
protective given that the risk for unrestricted use is greater than the risk
management range and that several VOCs were detected above industrial
screening levels.
The long-term effectiveness and permanence of the ICs under V0C2, V0C3,
and V0C4 would be nearly equal; however, the long-term reliability and
permanence of V0C4 would be increased relative to V0C3 with the addition
of SVE, which would physically remove VOCs. The long-term effectiveness
and permanence of the ICs under V0C2 and V0C3 would be nearly equal;
however, the long-term reliability and permanence of V0C3 would be
increased relative to V0C2 with the addition of ECs, which would control
migration of soil gas into indoor air. The long-term effectiveness and
permanence of the ICs under V0C2 would depend on the maintenance,
monitoring, and enforcement of the ICs. The criterion for long-term
effectiveness and permanence would not be met under NFA.
VOC alternatives:
Mobility and volume
would be significantly
reduced under V0C4.
V0C4 meets the statutory
preference for treatment,
but NFA, V0C2 and
V0C3 do not include
treatment.
VOC alternatives:
NFA, V0C2, and V0C3 would be
effective immediately; however,
there is uncertainty for V0C4
regarding the time required to
achieve industrial use PCGs.
Implementation of V0C2 would
entail no significant adverse risks to
the environment or health of the
community and workers. V0C3
would involve limited disruption of
shallow soils. V0C4 could require
installation of additional wells, but
short-term risks could be managed.
VOC alternatives:
NFA, V0C2, V0C3, and
V0C4 are implementable.
Coordination with the
SVE program would be
required.
VOC alternatives:
VOC2 = $88,000
VOC3 = $173,000
VOC4 = $181,000
84
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of lliiinnn llciilth iinil the
Km iron moil t
('ompliiince
with ARARs
Long-term LITectncss ;iikI I'crforniiincc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llroni>h Trciilmcnt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
CS T-037
VOC alternatives:
V0C4 would be protective because
volume and concentrations of VOCs
would be reduced. V0C3 would provide
additional protection compared to V0C2.
V0C2 would effectively prevent
unrestricted use.
NFA would not be protective given that the
risk for unrestricted use is at the upper end
of the risk management range and that
several VOCs were detected above
industrial screening levels.
VOC
alternatives:
V0C2, V0C3,
and V0C4
would comply
with ARARs.
VOC alternatives:
Risks under V0C3 and V0C4 would be acceptable. Risks under V0C2
would be acceptable, however, given the number of VOCs detected above
industrial screening levels, V0C3 would better protect industrial users.
Risks at the upper end of the risk management range for unrestricted use
and within the risk management range for industrial use. NFA would not be
protective given that the risk for unrestricted use is at the upper end of the
risk management range and that several VOCs were detected above
industrial screening levels.
The long-term effectiveness and permanence of the ICs under V0C2, V0C3,
and V0C4 would be nearly equal; however, the long-term reliability and
permanence of V0C4 would be increased relative to V0C3 with the addition
of SVE, which would physically remove VOCs. The long-term effectiveness
and permanence of the ICs under V0C2 and V0C3 would be nearly equal;
however, the long-term reliability and permanence of V0C3 would be
increased relative to V0C2 with the addition of ECs, which would control
migration of soil gas into indoor air. The long-term effectiveness and
permanence of the ICs under V0C2 would depend on the maintenance,
monitoring, and enforcement of the ICs. The criterion for long-term
effectiveness and permanence would not be met under NFA.
VOC alternatives:
Mobility and volume
would be significantly
reduced under V0C4.
V0C4 meets the statutory
preference for treatment,
but NFA, V0C2, and
V0C3 do not include
treatment.
VOC alternatives:
NFA, V0C2, and V0C3 would be
effective immediately; however,
there is uncertainty for V0C4
regarding the time required to
achieve industrial use PCGs.
Implementation of V0C2 would
entail no significant adverse risks to
the environment or health of the
community and workers. V0C3
would involve limited disruption of
shallow soils. V0C4 could require
installation of additional wells, but
short-term risks could be managed.
VOC alternatives:
NFA, V0C2, V0C3, and
V0C4 are implementable.
VOC alternatives:
V0C2 = $88,000
VOC3 = $173,000
VOC4 = $191,000
CS T-059
VOC alternatives:
Although risk is within the risk
management range for unrestricted use,
there is uncertainty regarding
characterization of SSG because only a
single SSG sample was collected. V0C3
would be protective and V0C2 would
effectively prevent unrestricted use. NFA
would not be protective given the
uncertainty of SSG characterization.
VOC
alternatives:
V0C2 and
V0C3 comply
with ARARs.
VOC alternatives:
Risks under V0C2 and V0C3 would be acceptable. Risks for unrestricted
use and industrial use are within the risk management range; however,
there is uncertainty regarding characterization of SSG because only a
single SSG sample was collected. NFA would not be protective given the
uncertainty of SSG characterization.
The long-term effectiveness and permanence of the ICs under V0C2 and
V0C3 would be nearly equal; however, the long-term reliability and
permanence of V0C3 would be increased relative to V0C2 with the addition
of ECs, which would control migration of soil gas into indoor air. The long-
term effectiveness and permanence of the ICs under V0C2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The criterion for
long-term effectiveness and permanence would not be met under NFA.
VOC alternatives:
NFA, V0C2, and V0C3
do not use treatment.
VOC alternatives:
NFA, V0C2, and V0C3 would be
effective immediately.
Implementation of V0C2 would
entail no significant adverse risks to
the environment or health of the
community and workers. V0C3
would involve limited disruption of
shallow soils.
VOC alternatives:
NFA, V0C2, and V0C3
are implementable.
VOC alternatives:
VOC2 = $98,300
VOC3 = $183,300
85
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiince
with ARARs
Long-term LITectncss ;iikI IViToriiiiiiuc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llroni>h Trciilmcnt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
PRL L-
001 (F2)
VOC alternatives:
VOC3 would be protective for future use
if a new building is constructed or an
existing building is renovated; however,
both VOC2 and VOC3 would prohibit
unrestricted use.
NFA would not be protective considering
risk is at the upper end of the risk
management range and the HI is greater
than 1 for the unrestricted use scenario.
Non-VOC alternatives:
Risk in soils is greater than the risk
management range for unrestricted use
and Non-VOC2 with ECs (e.g.,
maintaining surface cover) would
effectively prevent unrestricted use and
would be protective of surface water
quality.
NFA would not be protective considering
the risk for unrestricted use is greater than
the risk management range. NFA would
also not be protective of surface water
quality.
VOC
alternatives:
VOC2 and
VOC3 would
comply with
ARARs.
Non-VOC
alternatives:
Non-VOC2
would comply
with ARARs.
VOC alternatives:
Risks are at the upper end of the risk management range for unrestricted
use and within the risk management range for industrial use. The HI is
greater than 1 for the unrestricted use scenario. Risks under VOC3 would
be acceptable. Risks under VOC2 would be acceptable; however, there is
uncertainty associated with characterizing the entire length of the IWL.
Risks under NFA would not be acceptable.
The long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under VOC2 would
depend on the maintenance, monitoring, and enforcement of the ICs. The
criterion for long-term effectiveness and permanence would not be met
under NFA.
Non-VOC alternatives:
Risks under Non-VOC2 would be acceptable and would address protection
of surface water quality with ECs. Risks for unrestricted use are greater
than the risk management range and for industrial use are within the risk
management range. There are also potential impacts to surface water
quality. Risks under NFA would not be acceptable.
The long-term effectiveness and permanence of the ICs and ECs under Non-
VOC2 would depend on the maintenance, monitoring, and enforcement of
the ICs and ECs. The criterion for long-term effectiveness and permanence
would not be met under NFA.
VOC alternatives:
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
Non-VOC alternatives:
NFA and Non-VOC2 do
not meet the statutory
preference for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the environment or
health of the community and
workers.
VOC alternatives:
NFA, VOC2, and
VOC3 are
implementable.
Non-VOC alternatives:
NFA and Non-VOC2 are
implementable.
VOC alternatives:
VOC2 = $180,800
VOC3 = $288,800
Non-VOC alternatives:
Non-VOC2 = $88,000
86
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiince
with ARARs
Long-term LITectncss ;iikI IViToriiiiiiuc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llroni>h Trciilmcnt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
PRL L-
002
VOC alternatives:
VOC3 would be protective. VOC2
would effectively prevent unrestricted
use; however, risks are greater than the
risk management range for both
unrestricted and industrial use and the HI
is greater than 1 for both use scenarios,
so industrial users would not be
adequately protected.
NFA would not be protective considering
risks are greater than the risk
management range for both unrestricted
and industrial use and the HI is greater
than 1 for both use scenarios.
Non-VOC alternatives:
Risks in soils are greater than the risk
management range for unrestricted use
and within the risk management range
for industrial use. Non-VOC2 with ECs
(e.g., maintaining surface cover) would
effectively prevent unrestricted use and
would be protective of surface water
quality.
NFA would not be protective of surface
water quality.
VOC
alternatives:
VOC2 and
VOC3 would
comply with
ARARs.
Non-VOC
alternatives:
Non-VOC2
would comply
with ARARs.
VOC alternatives:
Risks under VOC2 would be acceptable. Risks under VOC3 would be
acceptable. Risks for both unrestricted use and industrial use are greater
than the risk management range. The HI is greater than 1 for both use
scenarios. NFA would not be protective considering risks are greater
than the risk management range for both unrestricted and industrial use
and the HI is greater than 1 for both use scenarios.
The long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under VOC2 would
depend on the maintenance, monitoring, and enforcement of the ICs. The
criterion for long-term effectiveness and permanence would not be met
under NFA.
Non-VOC alternatives:
Risks under Non-VOC2 would be acceptable. Risks for unrestricted use
are greater than the risk management range and for industrial use are
within the risk management range; however, excluding arsenic, risks are
within or below the risk management range for both use scenarios. There
are potential impacts to surface water quality, and Non-VOC2 would be
protective of surface water quality with ECs. NFA would not be protective
of surface water quality.
The long-term effectiveness and permanence of the ICs and ECs under Non-
VOC2 would depend on the maintenance, monitoring, and enforcement of
the ICs and ECs. The criterion for long-term effectiveness and permanence
would not be met under NFA.
VOC alternatives:
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
Non-VOC alternatives:
NFA and Non-VOC2 do
not meet the statutory
preference for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately, and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the environment or
health of the community and
workers.
VOC alternatives:
NFA, VOC2, and
VOC3 are
implementable.
Non-VOC alternatives:
NFA and Non-VOC2 are
implementable.
VOC alternatives:
VOC2 = $88,000
VOC3 = $196,000
Non-VOC alternatives:
Non-VOC2 = $88,000
87
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiince
with ARARs
Long-term LITectncss ;iikI IVrforniiiiuc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llroni>h Trciilmcnt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
PRL L-
003 (F2)
VOC alternatives:
VOC4 would be protective because
volume and concentrations of VOCs
would be reduced. VOC3 would provide
additional protection compared to VOC2.
VOC2 would effectively prevent
unrestricted use, but may not be
protective given the uncertainty
associated with characterizing the entire
length of the IWL.
NFA would not be protective given the
HI for unrestricted use is equal to 1.
Non-VOC alternatives:
Non-VOC4a and Non-VOC4b would
be protective for soil because
contaminants would be physically
removed. Non-VOC2 withECs (e.g.,
maintaining surface cover) would
effectively prevent unrestricted use and
would be protective of surface water
quality.
NFA would not be protective of
groundwater and surface water quality.
VOC
alternatives:
VOC2, VOC3,
and VOC4
would comply
with ARARs.
Non-VOC
alternatives:
Non-VOC2,
Non-VOC4a,
and Non-
VOC4b would
comply with
ARARs.
VOC alternatives:
Risks under VOC2 would be acceptable; however, given the uncertainties
related to characterizing the length of the entire IWL, VOC3 would be
protective of industrial users. Risks under VOC3 and VOC4 would be
acceptable. Risks for unrestricted use are at the upper end of the risk
management range and for industrial use are at the low end of risk
management range. The HI is equal to 1 for the unrestricted use scenario.
NFA would not be protective given the HI for unrestricted use is equal to
1.
The long-term effectiveness and permanence of the ICs under VOC2,
VOC3, and VOC4 would be nearly equal; however, the long-term
reliability and permanence of VOC4 would be increased relative to VOC3
with the addition of SVE, which would physically remove VOCs. The
long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under VOC2
would depend on the maintenance, monitoring, and enforcement of the ICs.
The criterion for long-term effectiveness and permanence would not be
met under NFA.
Non-VOC alternatives:
Risks (excluding arsenic and aluminum) for both unrestricted and industrial
use are within the risk management range. There are potential impacts to
groundwater and surface water quality, which would be addressed by Non-
VOC4a and Non-VOC4b. Potential impacts to surface water quality would
be addressed by Non-VOC2 using ECs. NFA would not be protective of
groundwater or surface water quality.
Non-VOC4b would be the most effective and permanent for soil because
levels acceptable for unrestricted use would be achieved by excavation and
offsite disposal. Under Non-VOC4a and Non-VOC2, residual contamination
would remain; however, ICs would provide continued protection of human
health. The long-term effectiveness and permanence of the ICs and ECs
under Non-VOC2 would depend on the maintenance, monitoring, and
enforcement of the ICs and ECs. The criterion for long-term effectiveness
and permanence would not be met under NFA.
VOC alternatives:
Mobility and volume
would be significantly
reduced under VOC4.
VOC2 and VOC3 do not
meet the statutory
preference for treatment.
Non-VOC alternatives:
NFA, Non-VOC2, Non-
VOC4a, and Non-VOC4b
to not meet the statutory
preference for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately; however,
there is uncertainty for VOC4
regarding the time required to
achieve industrial use PCGs.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils. VOC4 could require
installation of additional wells, but
short-term risks could be managed.
Non-VOC alternatives:
NFA and Non-VOC2 would
require the least amount of time to
implement for soil, and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the environment or
health of the community and
workers. Short-term risks during
excavation (Non-VOC4a and Non-
VOC4b) could be managed.
VOC alternatives:
NFA, VOC2, VOC3, and
VOC4 are implementable.
Non-VOC alternatives:
NFA, Non-VOC2, Non-
VOC4a, and Non-VOC4b
are implementable.
Current site use would be
disrupted during
excavation for Non-
VOC4a and Non-VOC4b.
VOC alternatives:
VOC2 = $175,700
VOC3 = $283,700
VOC4 = $214,000
Non-VOC alternatives:
Non-VOC2 = $88,000
Non-VOC4a= $331,000
Non-VOC4b = $252,000
88
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Protection of Human Health and the
Environment
Compliance
with ARARs
Long-term Effectivess and Performance
Reduction in Toxicity,
Mobility, and Volume
Through Treatment
Short-term Effectiveness
Implementability
Cost (PV30)
PRL L-
004
VOC alternatives:
VOC4 would be protective because
volume and concentrations of VOCs
would be reduced. VOC3 would provide
additional protection compared to VOC2.
VOC2 would effectively prevent
unrestricted use, but would not be
protective of industrial users given the
uncertainty associated with
characterizing the entire length of the
IWL and that the HI is greater than 1 for
industrial use.
NFA would not be protective given the
risk for unrestricted is greater than the
risk management range and the HI is
greater than 1 for both the unrestricted
and industrial use scenarios.
Non-VOC alternatives:
Non-VOC4a and Non-VOC4b would
generally be protective for soil because
TPH-G would be physically removed;
however, some areas of TPH-G
contamination are too deep for
excavation to be a feasible alternative.
Non-VOC3 would be protective. Non-
VOC2 withECs (e.g., maintaining
surface cover) would effectively prevent
unrestricted use and would be protective
of surface water quality.
NFA would be protective of human health
but potential impacts to surface water and
groundwater would remain.
VOC
alternatives:
VOC3 and
VOC4 would
comply with
ARARs.
Non-VOC
alternatives:
Non-VOC2,
Non-VOC3,
Non-VOC4a,
and Non-
VOC4b
would comply
with ARARs.
VOC alternatives:
Risks under VOC3 and VOC4 would be acceptable. VOC2 would
effectively prevent unrestricted use, but would not be protective of
industrial users. Risks for unrestricted use are greater than the risk
management range and for industrial use are within the risk management
range. The HI is greater than 1 for both use scenarios. NFA would not be
protective given the risk for unrestricted is greater than the risk management
range and the HI is greater than 1 for both the unrestricted and industrial use
scenarios.
The long-term effectiveness and permanence of the ICs under VOC2,
VOC3, and VOC4 would be nearly equal; however, the long-term
reliability and permanence of VOC4 would be increased relative to VOC3
with the addition of SVE, which would physically remove VOCs. The
long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under VOC2
would depend on the maintenance, monitoring, and enforcement of the ICs.
The criterion for long-term effectiveness and permanence would not be
met under NFA.
Non-VOC alternatives:
Risks for both unrestricted use and industrial use (excluding arsenic and
cadmium) are less than the risk management range. Non-VOC2 would
effectively prevent unrestricted use and would be protective of surface
water quality with ECs. NFA would be protective of human health but
potential impacts to surface water and groundwater would remain.
Non-VOC4b would be the most effective and permanent for soil because
levels acceptable for unrestricted use would be achieved by excavation and
offsite disposal. Under Non-VOC4a, Non-VOC3, and Non-VOC2, residual
contamination would remain; however, ICs and ECs would provide
continued protection of human health and water quality. Under Non-VOC2,
residual contamination would also remain in place; however, ICs and ECs
would provide continued protection of human health and surface water
quality. The long-term effectiveness and permanence of Non-VOC3 would
be increased relative to Non-VOC2 with the addition of bioventing. The
long-term effectiveness and permanence of the ICs and ECs under Non-
VOC2 would depend on the maintenance, monitoring, and enforcement of
the ICs and ECs. The criterion for long-term effectiveness and permanence
would not be met under NFA.
VOC alternatives:
Mobility and volume
would be significantly
reduced under VOC4.
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
Non-VOC alternatives:
Only Non-VOC3 would
meet the statutory
preference for treatment.
NFA, Non-VOC2, Non-
VOC4a, and Non-
VOC4b do not meet the
statutory preference for
treatment.
VOC alternatives:
NFA, VOC2, VOC3, and VOC4
would be effective immediately;
however, there is uncertainty for
VOC4 regarding the time required to
achieve industrial use PCGs.
Implementation of VOC2 would
entail no significant adverse risks to
the enviromnent or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils. VOC4 could require
installation of additional wells, but
short- term risks could be managed.
Non-VOC alternatives:
NFA and Non-VOC2 would
require the least amount of time to
implement for soil, and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the enviromnent or
health of the community and
workers. Short-term risks during
bioventing (Non-VOC3) and
excavation (Non-VOC4a and Non-
VOC4b) could be managed.
VOC alternatives:
NFA, VOC2, VOC3, and
VOC4 are implementable.
Coordination with the
SVE program would be
required for the VOC
alternatives.
Non-VOC alternatives:
NFA, Non-VOC2, Non-
VOC}, Non-VOC4a, and
Non- VOC4b are
implementable; however,
excavation (Non- VOC4a
and Non-VOC4b) may be
more difficult to
implement because
contamination likely
extends to 30 feet bgs and
these areas are located
between Buildings 473
and 475. Current site use
could be disrupted during
excavation for Non-
VOC4a and Non-VOC4b.
Some areas of TPH-G
contamination are too deep
for excavation to be a
feasible alternative.
VOC alternatives:
VOC2 = $88,000
VOC3 = $196,000
VOC4 = $203,000
Non-VOC alternatives:
Non-VOC2 = $407,000
Non-VOC3 = $861,000
Non-VOC4a = $953,000
Non-VOC4b = $874,000
89
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of lliiinnn llciilth iinil the
Km iron moil t
('ompliiiiHT
with ARARs
Long-term LITectncss ;iikI I'crforniiincc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llI'Olll>ll TrCilllllCIlt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
PRL L-
005 (F2)
VOC alternatives:
VOC4 would be protective because
volume and concentrations of VOCs
would be reduced. VOC3 would provide
additional protection compared to VOC2
if a new building is constructed or an
existing building is renovated; however,
both VOC2 and VOC3 would prohibit
unrestricted use. VOC2 may not be
protective of industrial users due to the
uncertainty associated with characterizing
the entire length of the IWL.
NFA would not be protective considering
risk for unrestricted use is greater than the
risk management range and the HI is
greater than 1 for the unrestricted use
scenario.
VOC
alternatives:
VOC2, VOC3,
andVOC4
would comply
with ARARs.
VOC alternatives:
Risks are greater than the risk management range for unrestricted use and
within the risk management range for industrial use. The HI is greater than
1 for the unrestricted use scenario. Risks under VOC4 and VOC3 would be
acceptable. Risks under VOC2 would be acceptable; however, there is
uncertainty associated with characterizing the entire length of the IWL so
VOC2 may not be sufficient to protect industrial users. Risks under NFA
would not be acceptable.
The long-term effectiveness and permanence of the ICs under VOC2, VOC3,
and VOC4 would be nearly equal; however, the long-term reliability and
permanence of VOC4 would be increased relative to VOC3 with the addition
of SVE, which would physically remove VOCs. The long-term reliability
and permanence of VOC3 would be increased relative to VOC2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under VOC2 would
depend on the maintenance, monitoring, and enforcement of the ICs. The
criterion for long-term effectiveness and permanence would not be met under
NFA.
VOC alternatives:
Mobility and volume
would be significantly
reduced under VOC4.
VOC4 meets the statutory
preference for treatment.
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately; however,
there is uncertainty for VOC4
regarding the time required to
achieve industrial use PCGs.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils. VOC4 could require
installation of additional wells, but
short-term risks could be managed.
VOC alternatives:
NFA, VOC2, VOC3, and
VOC4 are implementable.
VOC alternatives:
VOC2 = $165,400
VOC3 = $273,400
VOC4 = $236,000
PRL P-
001
Non-VOC alternatives:
Non-VOC4b would be protective
because contaminants would be
physically removed. Non-VOC2 with
ECs (e.g., maintaining surface cover)
would protect human health by
prohibiting unrestricted use and would
minimize or eliminate impacts to
surface water using surface cover.
NFA would be protective of human health,
but potential impacts to groundwater
would remain.
Non-VOC
alternatives:
Non-VOC2 and
Non-VOC4b
would comply
with ARARs.
Non-VOC alternatives:
Risks are at the low end of the risk management range for unrestricted use
and less than the risk management range for industrial use; however, there
are potential impacts to groundwater and surface water quality. Non-
VOC4b would be the most effective and permanent because levels
acceptable for unrestricted use would be achieved by excavation and offsite
disposal.
Under Non-VOC2, residual contamination would remain; however, ICs and
ECs would provide continued protection of surface water. The long-term
effectiveness and permanence of the ICs under Non-VOC2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The criterion for
long-term effectiveness and permanence would not be met under NFA.
Non-VOC alternatives:
Toxicity, mobility, and
volume would be
reduced at the site upon
excavation under Non-
VOC4b. NFA, Non-
VOC2, and Non-VOC4b
do not meet the statutory
preference for treatment.
Non-VOC alternatives:
NFA and Non-VOC2 would require
the least amount of time to
implement, and contaminated soil
would not be disturbed.
Implementation of Non-VOC2
would entail no significant adverse
risks to the environment or health
of the community and workers.
Short-term risks during excavation
(Non-VOC4b) could be managed.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non- VOC4b are
implementable. Current
site use would be disrupted
during excavation (Non-
VOC4b).
Non-VOC alternatives:
Non-VOC2 = $117,000
Non-VOC4b = $107,000
PRL P-
003
VOC alternatives:
VOC2 would effectively prevent
unrestricted use.
NFA would not be protective. Although
the risk for unrestricted use is within the
risk management range, there is
uncertainty regarding characterization of
SSG (only two sample locations within site
boundaries from the 2017 data gap
sampling, and two additional samples
located outside of the site boundaries).
VOC
alternatives:
VOC2 would
comply with
ARARs.
VOC alternatives:
Risks under VOC2 would be acceptable. Risks for unrestricted use are
within the risk management range and for industrial use are at the low end
of the risk management range. Risks may be acceptable under NFA, but
there is uncertainty regarding characterization of SSG (only two sample
locations within site boundaries from the 2017 sampling, and two previous
samples located outside of the site boundaries).
The long-term effectiveness and permanence of the ICs under VOC2 would
depend on the maintenance, monitoring, and enforcement of the ICs. The
criterion for long-term effectiveness and permanence would not be met under
NFA.
VOC alternatives:
NFA and VOC2 do not
meet the statutory
preference for treatment.
VOC alternatives:
NFA and VOC2 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse
risks to the environment or
health of the community and
workers.
VOC alternatives:
NFA and VOC2 are
implementable.
VOC alternatives:
VOC2 = $98,300
90
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Protection of Human Health and the
Environment
Compliance
with ARARs
Long-term Effectivess and Performance
Reduction in Toxicity,
Mobility, and Volume
Through Treatment
Short-term Effectiveness
Implementability
Cost (PV3o)
PRLP-
004
VOC alternatives:
VOC4 would be protective because
volume and concentrations of VOCs
would be reduced. VOC3 would provide
additional protection compared to VOC2
given the exceedance of the IC
Compliance level for chloroform during
the 2017 interim SSG data gap
investigation. VOC2 would effectively
prevent unrestricted use.
NFA would not be protective. Although
the risk for unrestricted use is within the
risk management range, there is
uncertainty regarding characterization of
SSG (two sample locations within site
boundaries from the 2017 sampling, but
historical sample locations are all outside
of the site boundaries).
VOC
alternatives:
VOC2, VOC3,
and VOC4
would comply
with ARARs.
VOC alternatives:
Risks under VOC3 and VOC4 would be acceptable. Risks under VOC2
would be acceptable. Risks for unrestricted use are within the risk
management range and for industrial use are at the low end of the risk
management range. Risks may be acceptable under NFA, but there is
uncertainty regarding characterization of SSG (two sample locations within
site boundaries from the 2017 sampling, but historical sample locations are
all outside of the site boundaries).
The long-term effectiveness and permanence of the ICs under VOC2, VOC3,
and VOC4 would be nearly equal; however, the long-term reliability and
permanence of VOC4 would be increased relative to VOC3 with the addition
of SVE, which would physically remove VOCs. The long-term effectiveness
and permanence of the ICs under VOC2 and VOC3 would be nearly equal;
however, the long-term reliability and permanence of VOC3 would be
increased relative to VOC2 with the addition of ECs, which would control
migration of soil gas into indoor air. The long-term effectiveness and
permanence of the ICs under VOC2 would depend on the maintenance,
monitoring, and enforcement of the ICs. The criterion for long-term
effectiveness and permanence would not be met under NFA.
VOC alternatives:
Mobility and volume
would be significantly
reduced under VOC4.
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately; however,
there is uncertainty for VOC4
regarding the time required to
achieve industrial use IC compliance
levels. Implementation of VOC2
would entail no significant adverse
risks to the enviromnent or health of
the community and workers. VOC3
would involve limited disruption of
shallow soils. VOC4 could require
installation of additional wells, but
short-term risks could be managed.
VOC alternatives:
NFA, VOC2, VOC3, and
VOC4 are implementable.
VOC alternatives:
VOC2 = $98,300
VOC3 = $183,300
VOC4 = $191,000
PRLS-
022 & SA
069
VOC alternatives:
VOC3 would provide additional
protection compared to VOC2 if a new
building is constructed or an existing
building is renovated; however, both
VOC2 and VOC3 would prohibit
unrestricted use. VOC2 may not be
protective of industrial users due to the
uncertainty associated with
characterizing SSG.
NFA would not be protective. Although
risks are within the risk management
range for unrestricted use, there is
uncertainty regarding SSG
characterization around PLS22SB013.
Non-VOC alternatives:
Non-VOC4a and Non-VOC4b would
be protective because TPH-D would
be physically removed. Non-VOC3
would be protective. Non-VOC2
would effectively prevent unrestricted
use.
NFA would be protective of human health
given that risk for unrestricted use
(excluding arsenic) is within the risk
management range, but potential impacts
to water quality would remain.
VOC
alternatives:
VOC2 and
VOC3 would
comply with
ARARs.
Non-VOC
alternatives:
Non-VOC2,
Non-VOC3,
Non-VOC4a,
and Non-
VOC4b
would comply
with ARARs.
VOC alternatives:
Risks under VOC2 would be acceptable. Risks under VOC3 would be
acceptable. Risks for unrestricted use are within the risk management
range. Risks for industrial use are at the low end of the risk management
range. Risks under NFA would not be acceptable. Although risks are
within the risk management range for unrestricted use, there is uncertainty
regarding SSG characterization around PLS22SB013.
The long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under VOC2 would
depend on the maintenance, monitoring, and enforcement of the ICs. The
criterion for long-term effectiveness and permanence would not be met
under NFA.
Non-VOC alternatives:
Risks for unrestricted use (excluding arsenic) are within the risk
management range and for industrial use (excluding arsenic) are at the low
end of the risk management range. NFA is not protective of groundwater
quality.
Non-VOC4b would be the most effective and permanent because levels
acceptable for unrestricted use would be achieved by excavation and offsite
disposal. Under Non-VOC4a, Non-VOC3, andNon-VOC2, residual
contamination would remain; however, ICs and ECs would provide
continued protection of human health and surface water quality. The long-
term effectiveness and permanence of Non-VOC3 would be increased
relative to Non-VOC2 with the addition of bioventing. The long-term
effectiveness and permanence of the ICs under Non-VOC2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The criterion for
long-term effectiveness and permanence would not be met under NFA.
VOC alternatives:
None of the evaluated
alternatives meet the
statutory preference for
treatment.
Non-VOC alternatives:
Only Non-VOC3 would
meet the statutory
preference for treatment.
NFA, Non-VOC2, Non-
VOC4a, and Non-
VOC4b do not meet the
statutory preference for
treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse risks to
the enviromnent or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils.
Non-VOC alternatives:
NFA and Non-VOC2 would require
the least amount of time to
implement, and contaminated soil
would not be disturbed.
Implementation of Non-VOC2
would entail no significant adverse
risks to the enviromnent or health
of the community and workers.
Short-term risks during bioventing
(Non-VOC3) and excavation (Non-
VOC4a and Non-VOC4b) could be
managed.
VOC alternatives:
NFA, VOC2, and
V0C3 are
implementable.
Non-VOC alternatives:
NFA, Non-VOC2, Non-
VOC3, Non-VOC4a, and
Non-VOC4b are
implementable; however,
excavation (Non-VOC4a
and Non-VOC4b) may be
more difficult to
implement because
contamination likely
extends to 25 feet bgs and
the area is located between
Buildings 355 and 367.
Current site use would be
disrupted during
excavation for Non-
VOC4a and Non-VOC4b.
VOC alternatives:
VOC2 = $160,200
VOC3 = $575,200
Non-VOC alternatives:
Non-VOC2 = $328,000
Non-VOC3 = $458,000
Non-VOC4a = $410,000
Non-VOC4b = $330,000
91
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Protection of Human Health and the
Environment
Compliance
with ARARs
Long-term Effectivess and Performance
Reduction in Toxicity,
Mobility, and Volume
Through Treatment
Short-term Effectiveness
Implementability
Cost (PV3o)
PRLS-
037
VOC alternatives:
VOC2 would be protective because
unrestricted use would be prohibited. NFA
would not be protective. Although risks are
within the risk management range for
unrestricted use, there are multiple VOCs
detected at concentrations exceeding
screening levels.
VOC
alternatives:
VOC2 would
comply with
ARARs.
VOC alternatives:
Risks are within the risk management range for unrestricted use and at the
low end of the risk management range for industrial use. Risks under
VOC2 would be acceptable. Risks under NFA would not be acceptable
because there are multiple VOCs detected at concentrations exceeding
screening levels.
The long-term effectiveness and permanence of the ICs under VOC2 would
depend on the maintenance, monitoring, and enforcement of the ICs. The
criterion for long-term effectiveness and permanence would not be met under
NFA.
VOC alternatives:
NFA and VOC2 do not
meet the statutory
preference for treatment.
VOC alternatives:
NFA and VOC2 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse
risks to the enviromnent or
health of the community and
workers.
VOC alternatives:
NFA and VOC2 are
implementable.
VOC alternatives:
VOC2 = $88,000
PRL T-
015
VOC alternatives:
VOC2 would effectively prevent
unrestricted use. NFA would not be
protective considering that the HI is
greater than 1 for the unrestricted use
scenario.
Non-VOC alternatives:
Non-VOC4a would be protective because
PCBs would be physically removed by
excavation and disposal of PCB-impacted
soil. Risks are less than risk management
range for both unrestricted use and
industrial use, but the HI is greater than 1
for the unrestricted use scenario.
Non-VOC2 would effectively prevent
unrestricted use. NFA would be not be
protective of human health given the HI
greater than 1.
VOC
alternatives:
VOC2
would
comply
with
ARARs.
Non-VOC
alternatives:
Non-VOC2 and
Non-VOC4a
would comply
with ARARs.
VOC alternatives:
Risks under VOC2 would be acceptable. Risk for unrestricted use is within
the risk management range, but the HI is greater than 1. Risk for industrial
use is less than the risk management range. The long-term effectiveness and
permanence of the ICs under VOC2 would depend on the maintenance,
monitoring, and enforcement of the ICs. NFA would not be protective
considering that the HI is greater than 1 for the unrestricted use scenario.
The long-term effectiveness and permanence of the ICs under VOC2
would depend on the maintenance, monitoring, and enforcement of the
ICs. The criterion for long-term effectiveness and permanence would not
be met under NFA.
Non-VOC alternatives:
Risks under both Non-VOC4a and Non-VOC2 would be acceptable. Risks
for both unrestricted use and industrial use are within the risk management
range; however, the HI is greater than 1 for the unrestricted use scenario.
NFA would not be protective of human health given the HI greater than 1
Both Non-VOC2 and Non-VOC4a would be effective and permanent;
however, the long-term effectiveness and permanence of Non-VOC4a would
be increased relative to Non-VOC2 due to the removal of PCBs at sample
location PL2SB004. The long-term effectiveness and permanence of the ICs
under Non-VOC2 would depend on the maintenance, monitoring, and
enforcement of the ICs. The criterion for long-term effectiveness and
permanence would not be met under NFA.
VOC alternatives:
NFA and VOC2 do not
meet the statutory
preference for
treatment.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4a do not meet
the statutory preference
for treatment.
VOC alternatives:
NFA and VOC2 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse
risks to the enviromnent or
health of the community and
workers.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the enviromnent or
health of the community and
workers. Short-term risks during
excavation (Non-VOC4a) could be
managed.
VOC alternatives:
NFA and
VOC2 are
implementable.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4a are
implementable. Current
site use would be disrupted
during excavation (Non-
VOC4a).
VOC alternatives:
VOC2 = $88,000
Non-VOC alternatives:
Non-VOC2 = $88,000
Non-VOC4a = $259,610
PRL T-
019
Non-VOC alternatives:
Non-VOC4a and Non-VOC4b would be
protective because TPH would be
physically removed.
Non-VOC3 would be protective. Non-
VOC2 would be protective of human
health. NFA would be protective of human
health considering that risk for unrestricted
use is at the low end of the risk
management range and the HI exceeds 1,
but potential impacts to groundwater
would remain.
Non-VOC
alternatives:
Non-VOC2,
Non-VOC3,
Non-VOC4a,
and Non-
VOC4b
would comply
with ARARs.
Non-VOC alternatives:
Risks for both unrestricted and industrial use (without thallium) are less
than the risk management range; however, there are potential impacts to
groundwater quality. NFA would be protective of human health, but
would not be protective of groundwater quality.
Non-VOC4b would be the most effective and permanent because levels
acceptable for unrestricted use would be achieved by excavation and offsite
disposal. However, Non-VOC2, Non-VOC3, and Non-VOC4a would also be
effective and permanent given that soil sampling would be performed to
verify that residual contamination would not impact groundwater. The long-
term effectiveness and permanence of Non-VOC3 would be increased
relative to Non-VOC2 with the addition of bioventing. The long-term
effectiveness and permanence of the ICs under Non-VOC2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The criterion for
long-term effectiveness and permanence would not be met under NFA.
Non-VOC alternatives:
Only Non-VOC3 would
meet the statutory
preference for treatment.
NFA, Non-VOC2, Non-
VOC4a, and Non-
VOC4b do not meet the
statutory preference for
treatment.
Non-VOC alternatives:
NFA and Non-VOC2 would require
the least amount of time to
implement, and contaminated soil
would not be disturbed.
Implementation of Non-VOC2
would entail no significant adverse
risks to the enviromnent or health
of the community and workers.
Short-term risks during bioventing
(Non-VOC3) and excavation (Non-
VOC4a and Non-VOC4b) could be
managed.
Non-VOC alternatives:
NFA, Non-VOC2, Non-
VOC}, Non-VOC4a, and
Non-VOC4b are
implementable. Current
site use would be disrupted
during excavation (Non-
VOC4a and Non-VOC4b).
Non-VOC alternatives:
Non-VOC2 = $248,000
Non-VOC3 = $458,000
Non-VOC4a = $251,000
Non-VOC4b = $172,000
92
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiince
with ARARs
Long-term LITectncss ;iikI IViToriiiiiiuc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llroni>h Trciilmcnt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
PRL T-
031
VOC alternatives:
VOC3 would be protective for future use
if a new building is constructed;
however, both VOC2 and VOC3 would
prohibit unrestricted use. NFA would not
be protective considering risks are
greater than the risk management range
for unrestricted use and the HI is greater
than 1 for the unrestricted use scenario.
Non-VOC alternatives:
For soil, Non-VOC4b would be protective
because contaminants would be physically
removed. Non-VOC2 would protect human
health by prohibiting unrestricted use.
NFA would not be protective since the
risks are greater than the risk management
range and the HI is greater than 1 for the
unrestricted use scenario.
VOC
alternatives:
VOC2 and
VOC3 would
comply with
ARARs.
Non-VOC
alternatives:
Non-VOC2 and
Non-VOC4b
would comply
with ARARs.
VOC alternatives:
Risks are greater than the risk management range for unrestricted use and
within the risk management range for industrial use. The HI is greater than
1 for the unrestricted use scenario. Risks under VOC3 would be acceptable.
Risks under VOC2 would be acceptable. Risks under NFA would not be
acceptable.
The long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under VOC2
would depend on the maintenance, monitoring, and enforcement of the ICs.
Considering the relatively low risks for industrial use, VOC2 is protective.
The criterion for long-term effectiveness and permanence would not be met
under NFA.
Non-VOC alternatives:
Soil risks (excluding arsenic) are within the risk management range for
unrestricted use and less than the risk management range for industrial
use; however, the HI is greater than 1 for the unrestricted use scenario
after excluding arsenic. Under Non-VOC2, residual contamination would
remain; however, ICs would provide continued protection of human
health.
Non-VOC4b would be the most effective and permanent because levels
acceptable for unrestricted use would be achieved by excavation and offsite
disposal. The long-term effectiveness and permanence of the ICs under Non-
VOC2 would depend on the maintenance, monitoring, and enforcement of
the ICs. The criterion for long-term effectiveness and permanence would not
be met under NFA.
VOC alternatives:
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4b do not meet
the statutory preference
for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the environment or
health of the community and
workers. Short-term risks during
excavation (Non-VOC4b) could be
managed.
VOC alternatives:
NFA, VOC2, and
VOC3 are
implementable.
Non-VOC alternatives:
NFA, Non-VOC2 and
Non-VOC4b are
implementable. Current
site use would be disrupted
during excavation (Non-
VOC4b).
VOC alternatives:
VOC2 = $88,000
VOC3 = $182,000
Non-VOC alternatives:
Non-VOC2 = $88,000
Non-VOC4bb =
$3,395,300
93
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiiiHT
with ARARs
Long-term LITectncss ;iikI I'crforniiincc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llI'Olll>ll TrCilllllCIlt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
PRL T-
033
VOC alternatives:
VOC3 would be protective for future use
if a new building is constructed;
however, both VOC2 and VOC3 would
prohibit unrestricted use. NFA would not
be protective considering the HI is
greater than 1 for the unrestricted use
scenario.
Non-VOC alternatives:
For soil, Non-VOC4b would be protective
because contaminants would be physically
removed. Non-VOC2 withECs (e.g.,
maintaining surface cover) would protect
human health by prohibiting unrestricted
use and would minimize or eliminate
impacts to surface water using surface
cover. NFA would be protective of human
health, but potential impacts to water
quality would remain.
VOC
alternatives:
VOC2 and
VOC3 would
comply with
ARARs.
Non-VOC
alternatives:
Non-VOC2 and
Non-VOC4b
would comply
with ARARs.
VOC alternatives:
Risks within the risk management range for both unrestricted and
industrial use, but the HI is greater than 1 for the unrestricted use scenario.
Risks under VOC3 would be acceptable. Risks under VOC2 would be
acceptable. Risks under NFA would not be acceptable.
The long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under VOC2 would
depend on the maintenance, monitoring, and enforcement of the ICs. The
criterion for long-term effectiveness and permanence would not be met
under NFA.
Non-VOC alternatives:
Soil risks exceed the risk management range for unrestricted use and are
less than the risk management range for industrial use. PAH contamination
is addressed under PRL S-044.
Non-VOC4b would be the most effective and permanent because levels
acceptable for unrestricted use would be achieved by excavation and offsite
disposal. Under Non-VOC2, residual contamination would remain; however,
ICs and ECs would provide continued protection of human health and
surface water. The long-term effectiveness and permanence of the ICs under
Non-VOC2 would depend on the maintenance, monitoring, and enforcement
of the ICs. The criterion for long-term effectiveness and permanence would
not be met under NFA.
VOC alternatives:
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4b do not meet
the statutory preference
for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils.
Non-VOC alternatives:
NFA and Non-VOC2 would
require the least amount of time to
implement for soil, and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the environment or
health of the community and
workers. Short-term risks during
excavation (Non-VOC4b) could be
managed.
VOC alternatives:
NFA, VOC2, and
VOC3 are
implementable.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4b are
implementable. Current
site use would be disrupted
during excavation (Non-
VOC4b).
VOC alternatives:
VOC2 = $88,000
VOC3 = $176,000
Non-VOC alternatives:
Non-VOC2 = $130,000
Non-VOC4b = $125,000
SA037
VOC alternatives:
NFA would not be protective. Although
risks are within the risk management range
for unrestricted use, VOCs are present
above their screening levels. VOC3 would
be protective, but VOC2 would effectively
prevent unrestricted use.
VOC
alternatives:
VOC2 and
VOC3 would
comply with
ARARs.
VOC alternatives:
Risks under NFA would not be acceptable and under VOC2 would be
acceptable, because VOCs are present above their screening levels. Risks
under VOC2 and VOC3 would be acceptable. Risks for unrestricted use
are within the risk management range. Risks for industrial use are at the
low end of the risk management range. Considering the relatively low risks
for residential and industrial use, VOC2 is protective.
The long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the addition
of ECs, which would control migration of soil gas into indoor air. The long-
term effectiveness and permanence of the ICs under VOC2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The criterion for
long-term effectiveness and permanence would not be met under NFA.
VOC alternatives:
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils.
VOC alternatives:
NFA, VOC2, and VOC3
are implementable.
VOC alternatives:
VOC2 = $88,000
VOC3 = $220,000
94
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Protection of Human Health and the
Environment
Compliance
with ARARs
Long-term Effectivess and Performance
Reduction in Toxicity,
Mobility, and Volume
Through Treatment
Short-term Effectiveness
Implementability
Cost (PV3o)
SA038
VOC alternatives:
NFA would not be protective. Although
risks are at the low end of the risk
management range for unrestricted use,
there are uncertainties regarding SSG
characterization. VOC2 would
effectively prevent unrestricted use.
Non-VOC alternatives:
Non-VOC4a and Non-VOC4b would be
protective because TPH would be
physically removed. Non-VOC3 would
be protective. Non-VOC2 would be
protective of human health. NFA would
be protective of human health given that
no soil COPCs were identified and no
risk calculations were completed, but
potential impacts to groundwater would
remain.
VOC
alternatives:
VOC2
would
comply
with
ARARs.
Non-VOC
alternatives:
Non-VOC2,
Non-VOC3,
Non-VOC4a,
and Non-
VOC4b would
comply with
ARARs
VOC alternatives:
Risks under NFA would not be acceptable because there are uncertainties
regarding SSG characterization. Risks under VOC2 would be acceptable.
Risks for unrestricted use are at the low end of the risk management
range, and risks for industrial use are less than the risk management
range. Considering the relatively low risks for residential and industrial
use, VOC2 is protective and is necessary given the uncertainty related to
characterization of SSG.
The long-term effectiveness and permanence of the ICs under VOC2
would depend on the maintenance, monitoring, and enforcement of the
ICs. The criterion for long-term effectiveness and permanence would not
be met under NFA.
Non-VOC alternatives:
Non-VOC4b would be the most effective and permanent because levels
acceptable for unrestricted use would be achieved by excavation and offsite
disposal. However, Non-VOC3, and Non-VOC4a would also be effective
and permanent given that soil sampling would be performed to verify that
residual contamination would not impact groundwater. The long-term
effectiveness and permanence of the ICs under Non-VOC2 would depend
on the maintenance, monitoring, and enforcement of the ICs. NFA would
not address potential impacts to groundwater quality.
VOC alternatives:
NFA and VOC2 do not
meet the statutory
preference for
treatment.
Non-VOC alternatives:
Only Non-VOC3 would
meet the statutory
preference for treatment.
NFA, Non-VOC2, Non-
VOC4a, and Non-
VOC4b do not meet the
statutory preference for
treatment.
VOC alternatives:
NFA and VOC2 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse
risks to the enviromnent or
health of the community and
workers.
Non-VOC alternatives:
NFA and Non-VOC2 would require
the least amount of time to
implement, and contaminated soil
would not be disturbed.
Implementation of Non-VOC2
would entail no significant adverse
risks to the enviromnent or health
of the community and workers.
Short-term risks during bioventing
(Non VOC3) and excavation (Non-
VOC4a and Non-VOC4b) could be
managed.
VOC alternatives:
NFA and
VOC2 are
implementable.
Non-VOC alternatives:
NFA, Non-VOC2, Non-
VOC3, Non-VOC4a, and
Non-VOC4b are
implementable; however,
excavation (Non-VOC4a
and Non-VOC4b) may be
more difficult to
implement because
contamination likely
extends to 30 feet bgs and
the area is located adjacent
to Building 26. Current
site use would be disrupted
during excavation (Non-
VOC4a and Non-VOC4b).
The target volume is
adjacent to Building 26,
which could complicate
excavation (Non-VOC4a
and Non-VOC4b).
VOC alternatives:
VOC2 = $98,300
Non-VOC alternatives:
Non-VOC2 = $248,000
Non-VOC3= $458,000
Non-VOC4a = $218,000
Non-VOC4b = $139,000
SA040
VOC alternatives:
NFA would not be protective. Although
risks are at the low end of the risk
management range for unrestricted use,
there are uncertainties regarding SSG
characterization. Although two
additional SSG samples were collected
during the 2017 sampling, no revised
risks were calculated and uncertainties
regarding SSG characterization remain.
VOC2 would effectively prevent
unrestricted use.
Non-VOC alternatives:
Although the site is currently completely
paved by asphalt or covered by former
building foundation. NFA would not
require maintaining surface cover and
would therefore not be protective of
surface water. Non-VOC2 withECs (e.g.,
maintaining surface cover) would be
protective of surface water.
VOC
alternatives:
VOC2
would
comply
with
ARARs.
Non-VOC
alternatives:
Non-VOC2
would comply
with ARARs.
VOC alternatives:
Risks under NFA would not be acceptable because there are uncertainties
regarding SSG characterization. Risks under VOC2 would be acceptable.
Risks for unrestricted use are at the low end of the risk management
range, and risks for industrial use are less than the risk management
range. Considering the relatively low risks for residential and industrial
use, VOC2 is protective and is necessary given the uncertainty related to
characterization of SSG. Although two additional SSG samples were
collected during the 2017 sampling, no revised risks were calculated and
uncertainties regarding SSG characterization remain.
The long-term effectiveness and permanence of the ICs under VOC2
would depend on the maintenance, monitoring, and enforcement of the
ICs. The criterion for long-term effectiveness and permanence would not
be met under NFA.
Non-VOC alternatives:
Non-VOC2 would be the most effective and acceptable to address impacts
to surface water quality. Soil risks (excluding arsenic) are less than the risk
management range for both unrestricted use and industrial use, but the HI
for unrestricted use would exceed 1. Also, there are potential impacts
surface water quality from soil.
The long-term effectiveness and permanence of the ICs under Non-VOC2
would depend on the maintenance, monitoring, and enforcement of the ICs.
NFA would not address potential impacts to surface quality.
VOC alternatives:
NFA and VOC2 do not
meet the statutory
preference for treatment
Non-VOC alternatives:
NFA and Non-VOC2 do
not meet the statutory
preference for treatment.
VOC alternatives:
NFA and VOC2 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse
risks to the enviromnent or
health of the community and
workers.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the enviromnent or
health of the community and
workers.
VOC alternatives:
NFA and
VOC2 are
implementable.
Non-VOC alternatives:
NFA and Non-VOC2 are
implementable.
VOC alternatives:
VOC2 = $108,600
Non-VOC alternatives:
Non-VOC2 = $88,000
95
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiiiHT
with ARARs
Long-term LITectncss ;iikI I'crforniiincc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llI'Olll>ll TrCilllllCIlt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
SA043
VOC alternatives:
V0C3 would be protective for future use
if a new building is constructed or the
existing building is renovated; however,
both V0C2 and V0C3 would prohibit
unrestricted use. NFA would not be
protective. Although soil risks are within
the risk management range for
unrestricted use, there are uncertainties
regarding SSG characterization.
Non-VOC alternatives:
For soil, Non-VOC4b would be protective
because contaminants would be physically
removed. Non-VOC2 would protect human
health by prohibiting unrestricted use.
NFA would not be protective considering
the HI for the unrestricted use scenario is
greater than 1. NFA would also not be
protective of groundwater quality.
VOC
alternatives:
VOC2 and
VOC3 would
comply with
ARARs.
Non-VOC
alternatives:
VOC2 and Non-
VOC4b would
comply with
ARARs.
VOC alternatives:
Risks are within the risk management range for unrestricted use and at the
low end of the risk management range for industrial use. Risks under
VOC3 and VOC2 would be acceptable. Risks under NFA would not be
acceptable because there is uncertainty regarding SSG characterization.
The long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under VOC2 would
depend on the maintenance, monitoring, and enforcement of the ICs.
Considering the relatively low risks for residential and industrial use,
VOC2 is protective given the uncertainty related to characterization of
SSG. The criterion for long-term effectiveness and permanence would not
be met under NFA.
Non-VOC alternatives:
The current soil HI (excluding arsenic) is greater than 1 for the unrestricted
use scenario. Soil risks (excluding arsenic) are less than the risk
management range for unrestricted use and less than the risk management
range for industrial use. NFA would not be protective considering the HI
for the unrestricted use scenario is greater than 1. NFA would also not be
protective of groundwater quality.
Non-VOC4b would be the most effective and permanent because levels
acceptable for unrestricted use would be achieved by excavation and offsite
disposal. Under Non-VOC2, residual contamination would remain; however,
ICs would provide continued protection of human health. The long-term
effectiveness and permanence of the ICs under Non-VOC2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The criterion for
long-term effectiveness and permanence would not be met under NFA.
VOC alternatives:
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4b do not meet
the statutory preference
for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils.
Non-VOC alternatives:
NFA and Non-VOC2 would
require the least amount of time to
implement for soil, and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the environment or
health of the community and
workers. Short-term risks during
excavation (Non-VOC4b) could be
managed.
VOC alternatives:
NFA, VOC2, and
VOC3 are
implementable.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4b are
implementable. Current
site use would be disrupted
during excavation (Non-
VOC4b).
VOC alternatives:
VOC2 = $103,500
VOC3 = $289,500
Non-VOC alternatives:
Non-VOC2 = $88,000
Non-VOC4b = $166,000
SA044
VOC alternatives:
V0C3 would be protective for future use if
a new building is constructed or the
existing building is renovated; however,
both V0C2 and V0C3 would prohibit
unrestricted use. NFA would not be
protective. Although VOCs were not
detected in SSG, there is insufficient data
to characterize SSG. Two additional SSG
samples were collected during the 2017
sampling, but this information is not
sufficient to fully characterize the site and
elevated TCE concentrations were
detected.
VOC
alternatives:
VOC2 and
VOC3 would
comply with
ARARs.
VOC alternatives:
VOCs were not detected in SSG (by M18MS which has elevated detection
limits for TCE); however, data indicate TCE may be present at
concentrations greater than unrestricted use screening levels, but likely less
than industrial use screening levels. The interim SSG data gap investigation
confirmed the presence of elevated TCE concentrations. Risks under
VOC3 and VOC2 would be acceptable. Risks under NFA are unacceptable
given the insufficient data to characterize SSG. Although additional SSG
samples were collected during the 2017 sampling, revised risk was not
calculated and uncertainty regarding SSG characterization remains.
The long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the addition
of ECs, which would control migration of soil gas into indoor air. The long-
term effectiveness and permanence of the ICs under VOC2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The criterion for
long-term effectiveness and permanence would not be met under NFA.
VOC alternatives:
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would
be effective immediately.
Implementation of VOC2 would
entail no significant adverse
risks to the environment or
health of the community and
workers. VOC3 would involve
limited disruption of shallow
soils.
VOC alternatives:
NFA, VOC2, and VOC3
are implementable.
VOC alternatives:
VOC2 = $108,600
VOC3 = $196,000
96
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiiiHT
with ARARs
Long-term LITectncss ;iikI I'crforniiincc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llI'Olll>ll TrCilllllCIlt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
SA047
VOC alternatives:
V0C2 would be protective because
unrestricted use would be prohibited.
NFA would not be protective. Although
VOCs were not detected in SSG, there is
insufficient data to characterize SSG.
Non-VOC alternatives:
For soil, Non-VOC4a would be protective
because contaminants would be physically
removed. Non-VOC2 would protect human
health by prohibiting unrestricted use.
Non-VOC2 with ECs would also be
protective of surface water quality. NFA
would not be protective of human health,
given that the HI is greater than 1 for the
unrestricted use scenario. NFA would also
not be protective of surface water quality.
VOC
alternatives:
V0C2
would
comply
with
ARARs.
Non-VOC
alternatives:
Non-VOC2 and
Non-VOC4a
would comply
with ARARs.
VOC alternatives:
VOCs were not detected in SSG (by M18MS which has elevated detection
limits for TCE); however, data indicate TCE may be present at
concentrations greater than unrestricted use screening levels, but likely less
than industrial use screening levels. Risks under V0C2 would be
acceptable. Risks under NFA are likely acceptable; however, there is
insufficient data to characterize SSG.
The long-term effectiveness and permanence of the ICs under V0C2
would depend on the maintenance, monitoring, and enforcement of the
ICs. The criterion for long-term effectiveness and permanence would not
be met under NFA.
Non-VOC alternatives:
Soil risks (excluding arsenic) are less than the risk management range for
both unrestricted use and industrial use; however, the HI is still greater
than 1 for unrestricted use when arsenic is excluded. Risks under Non-
V0C2 are acceptable. Although residual contamination would remain, ICs
and ECs would provide continued protection of human health and surface
water quality.
Non-VOC4a would also be effective and permanent given that post-
excavation soil sampling would be performed to verily that residual
contamination would not impact groundwater. The long-term effectiveness
and permanence of the ICs and ECs under Non-VOC2 would depend on the
maintenance, monitoring, and enforcement of the ICs and ECs. The
criterion for long-term effectiveness and permanence would not be met
under NFA.
VOC alternatives:
NFA and V0C2 do not
meet the statutory
preference for
treatment.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4a do not meet
the statutory preference
for treatment.
VOC alternatives:
NFA and V0C2 would be
effective immediately.
Implementation of V0C2 would
entail no significant adverse
risks to the environment or
health of the community and
workers.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately, and
contaminated soil would not be
disturbed. Implementation of Non-
V0C2 would entail no significant
adverse risks to the environment or
health of the community and
workers. Short-term risks during
excavation (Non- V0C4a) could
be managed.
VOC alternatives:
NFA and
V0C2 are
implementable.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non- V0C4a are
implementable. Current
site use would be disrupted
during excavation (Non-
V0C4a).
VOC alternatives:
V0C2 = $108,600
Non-VOC alternatives:
Non-VOC2 = $88,000
Non-VOC4ab =
$238,900
SA048
VOC alternatives:
NFA would not be protective. Although
risks are within the risk management range
for unrestricted use, there is uncertainty
regarding SSG characterization. V0C3
would be protective but V0C2 would
effectively prevent unrestricted use.
VOC
alternatives:
V0C2 and
V0C3 would
comply with
ARARs.
VOC alternatives:
Risks under NFA would not be acceptable because there is uncertainty
regarding SSG characterization. Risks under V0C2 and V0C3 would be
acceptable. Risks for both unrestricted use and industrial use are within
the risk management range. Considering the relatively low risks for
residential and industrial use, V0C2 is protective and is necessary given
the uncertainty related to characterization of SSG. The long-term
effectiveness and permanence of the ICs under V0C2 would depend on
the maintenance, monitoring, and enforcement of the ICs.
The long-term effectiveness and permanence of the ICs under V0C2 would
depend on the maintenance, monitoring, and enforcement of the ICs. The
criterion for long-term effectiveness and permanence would not be met under
NFA.
VOC alternatives:
NFA, V0C2, and V0C3
do not meet the statutory
preference for treatment.
VOC alternatives:
NFA, V0C2, and V0C3 would be
effective immediately.
Implementation of V0C2 would
entail no significant adverse risks to
the environment or health of the
community and workers. V0C3
would involve limited disruption of
shallow soils.
VOC alternatives:
NFA, V0C2, and V0C3
are implementable.
VOC alternatives:
VOC2 = $124,100
VOC3 = $404,100
97
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiince
with ARARs
Long-term LITectncss ;iikI I'crforniiincc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llroni>h Trciilmcnt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
SA053
VOC alternatives:
V0C3 would be protective. V0C2 would
effectively prevent unrestricted use;
however, given the concentration of TCE
above IC compliance level, V0C2 may not
be protective of industrial users. NFA
would not be protective of human health
given that SSG risk for unrestricted use is
at the high end of the risk management
range and there is uncertainty regarding
SSG characterization.
VOC
alternatives:
V0C2 and
V0C3 would
comply with
ARARs.
VOC alternatives:
Risks under V0C3 would be acceptable. Risks under V0C2 would be
acceptable, however, because TCE was detected above the IC compliance
level, V0C3 would better protect industrial users. Risks for industrial use
are at the low end of the risk management range, while risks for
unrestricted use are at the upper end of the risk management range. NFA
would not be protective of human health given that SSG risk for
unrestricted use is at the high end of the risk management range and there
is uncertainty regarding SSG characterization.
The long-term effectiveness and permanence of the ICs under V0C2 and
V0C3 would be nearly equal; however, the long-term reliability and
permanence of V0C3 would be increased relative to V0C2 with the addition
of ECs, which would control migration of soil gas into indoor air. The long-
term effectiveness and permanence of the ICs under V0C2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The criterion for
long-term effectiveness and permanence would not be met under NFA.
VOC alternatives:
NFA, V0C2, and V0C3
do not meet the statutory
preference for treatment.
VOC alternatives:
NFA, V0C2, and V0C3 would be
effective immediately.
Implementation of V0C2 would
entail no significant adverse risks to
the environment or health of the
community and workers. V0C3
would involve limited disruption of
shallow soils.
VOC alternatives:
NFA, V0C2, and V0C3
are implementable.
VOC alternatives:
V0C2 = $113,800
VOC3 = $393,800
SA058
VOC alternatives:
V0C3 would be protective. V0C2 would
effectively prevent unrestricted use;
however, given the number of VOCs above
industrial screening levels and that SSG
risk for industrial use is at the high end of
the risk management range, V0C2 may not
be protective of industrial users. NFA
would not be protective of human health
given that SSG risk for unrestricted use is
greater than the risk management range
and that the HI is greater than 1 for the
unrestricted use scenario.
VOC
alternatives:
V0C3 would
comply with
ARARs.
VOC alternatives:
Risks under V0C3 would be acceptable. Risks under V0C2 would be
acceptable, however, because the industrial risk is at the upper end of the
risk management range, V0C3 would better protect industrial users. NFA
would not be protective of human health. Risks for unrestricted use are
greater than the risk management range and for industrial use are at the high
end of the risk management range. The HI is greater than 1 for the
unrestricted use scenario.
The long-term effectiveness and permanence of the ICs under V0C2 and
V0C3 would be nearly equal; however, the long-term reliability and
permanence of V0C3 would be increased relative to V0C2 with the addition
of ECs, which would control migration of soil gas into indoor air. The long-
term effectiveness and permanence of the ICs under V0C2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The criterion for
long-term effectiveness and permanence would not be met under NFA.
VOC alternatives:
NFA, V0C2, and V0C3
do not meet the statutory
preference for treatment.
VOC alternatives:
NFA, V0C2, and V0C3 would be
effective immediately.
Implementation of V0C2 would
entail no significant adverse risks to
the environment or health of the
community and workers.
V0C3 would involve limited
disruption of shallow soils.
VOC alternatives:
NFA, V0C2, and V0C3
are implementable.
VOC alternatives:
VOC2 = $88,000
VOC3 = $173,000
98
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiiiHT
with ARARs
Long-term LITectncss ;iikI I'crforniiincc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llI'Olll>ll TrCilllllCIlt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
SA059
VOC alternatives:
NFA would not be protective. Although
risks are at the low end of the risk
management range for unrestricted use,
there is uncertainty regarding SSG
characterization. V0C2 would
effectively prevent unrestricted use.
Non-VOC alternatives:
Non-VOC4b would be protective because
contaminants would be physically
removed. Non-VOC2 withECs (e.g.,
maintaining surface cover) would
effectively prevent unrestricted use and
would be protective of surface water
quality. NFA would be protective of
human health considering that risks for
unrestricted use are at the low end of the
risk management range, but NFA would
not require maintaining surface cover and
would therefore not be protective of
surface water and groundwater quality.
VOC
alternatives:
V0C2
would
comply
with
ARARs.
Non-VOC
alternatives:
Non-VOC2 and
Non-VOC4b
would comply
with ARARs.
VOC alternatives:
Risks under NFA would not be acceptable because there is uncertainty
regarding SSG characterization. Risks under V0C2 would be acceptable;
however, there is uncertainty regarding SSG characterization. Risks for
unrestricted use are at the low end of the risk management range and risks
for industrial use are less than the risk management range. Considering the
relatively low risks for residential and industrial use, V0C2 is protective
given the uncertainty related to characterization of SSG. The long-term
effectiveness and permanence of the ICs under V0C2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The long-term
effectiveness and permanence of the ICs under V0C2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The criterion for
long-term effectiveness and permanence would not be met under NFA.
Non-VOC alternatives:
Risks for industrial use are less than the risk management range.
Non-VOC4b would be the most effective and permanent because levels
acceptable for unrestricted use would be achieved by excavation and offsite
disposal. Under Non-VOC2, residual contamination would remain; however,
ICs and ECs would provide continued protection of human health and
surface water quality. The long-term effectiveness and permanence of the
ICs and ECs under Non-VOC2 would depend on the maintenance,
monitoring, and enforcement of the ICs and ECs. NFA would not be
protective of surface water and ground water quality.
VOC alternatives:
NFA and V0C2 do not
meet the statutory
preference for
treatment.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4b do not meet
the statutory preference
for treatment.
VOC alternatives:
NFA and V0C2 would be
effective immediately.
Implementation of V0C2 would
entail no significant adverse
risks to the environment or
health of the community and
workers.
Non-VOC alternatives:
NFA and Non-VOC2 would require
the least amount of time to
implement, and contaminated soil
would not be disturbed.
Implementation of Non-VOC2
would entail no significant adverse
risks to the environment or health
of the community and workers.
Short-term risks during excavation
(Non-VOC4b) could be managed.
VOC alternatives:
NFA and
V0C2 are
implementable.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4b are
implementable. Current
site use would be disrupted
during excavation (Non-
V0C4b).
VOC alternatives:
V0C2 = $108,600
Non-VOC alternatives:
Non-VOC2 = $88,000
Non-VOC4b = $119,000
SA067
VOC alternatives:
V0C3 would provide additional
protection compared to V0C2 if a new
building is constructed or an existing
building is renovated; however, both
V0C2 and V0C3 would prohibit
unrestricted use. V0C2 may not be
protective of industrial users due to the
uncertainty associated with
characterizing SSG.
NFA would not be protective. Although
SSG risks for unrestricted use are at the
low end of the risk management range,
there is insufficient data to characterize
SSG.
VOC
alternatives:
V0C2 and
V0C3 would
comply with
ARARs.
VOC alternatives:
Risks under V0C2 would be acceptable. Risks under V0C3 would be
acceptable. Risks under NFA are likely acceptable; however, there is
insufficient data to characterize SSG. Risks for unrestricted use are at the
low end of the risk management range and risks for industrial use are
below the risk management range. Although risks are within the risk
management range for unrestricted use, there is uncertainty regarding SSG
characterization.
The long-term effectiveness and permanence of the ICs under V0C2 and
V0C3 would be nearly equal; however, the long-term reliability and
permanence of V0C3 would be increased relative to V0C2 with the addition
of ECs, which would control migration of soil gas into indoor air. The long-
term effectiveness and permanence of the ICs under V0C2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The criterion for
long-term effectiveness and permanence would not be met under NFA.
VOC alternatives:
None of the evaluated
alternatives meet the
statutory preference for
treatment.
VOC alternatives:
NFA, V0C2, and V0C3 would be
effective immediately.
Implementation of V0C2 would
entail no significant adverse risks to
the environment or health of the
community and workers. V0C3
would involve limited disruption of
shallow soils.
VOC alternatives:
NFA, V0C2, and V0C3
are implementable.
VOC alternatives:
VOC2 = $149,900
VOC3 = $931,000
99
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiiiHT
with ARARs
Long-term LITectncss ;iikI I'ei loi iiiitiuc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llI'Olll>ll TrCilllllCIlt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
SA068
VOC alternatives:
VOC2 would be protective because
unrestricted use would be prohibited. NFA
would not be protective. Although SSG
risks for unrestricted use are at the low end
of the risk management range, there is
insufficient data to characterize SSG. Two
additional SSG samples were collected
during the 2017 sampling, but no revised
risks were calculated and uncertainties
regarding SSG characterization remain.
VOC
alternatives:
VOC2 would
comply with
ARARs.
VOC alternatives:
Risks under VOC2 would be acceptable. Risks under NFA are likely
acceptable; however, there is insufficient data to characterize SSG. Risks
for unrestricted use are at the low end of the risk management range and
risks for industrial use are below the risk management range. Although two
additional SSG samples were collected during the 2017 sampling, no
revised risks were calculated and uncertainties regarding SSG
characterization remain.
The long-term effectiveness and permanence of the ICs under VOC2 would
depend on the maintenance, monitoring, and enforcement of the ICs. The
criterion for long-term effectiveness and permanence would not be met under
NFA.
VOC alternatives:
NFA and VOC2 do not
meet the statutory
preference for treatment.
VOC alternatives:
NFA and VOC2 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse
risks to the environment or
health of the community and
workers.
VOC alternatives:
NFA and VOC2 are
implementable.
VOC alternatives:
VOC2 = $108,600
SA071
VOC alternatives:
NFA would not be protective. Although
risks are within the risk management
range for unrestricted use, there is
uncertainty regarding SSG
characterization. VOC2 would
effectively prevent unrestricted use.
Non-VOC alternatives:
Soil risks (excluding arsenic) are less than
the risk management range for unrestricted
use, but the HI would still exceed 1. For
soil, Non-VOC4a would be protective
because contaminants would be physically
removed. Non-VOC2 withECs (e.g.,
maintaining surface cover) would be
protective of human health and of surface
water quality. NFA would not be
protective of human health, given that the
HI is greater than 1 (excluding arsenic) for
the unrestricted use scenario. NFA would
also not require maintaining surface cover
and would therefore not be protective of
surface water quality.
VOC
alternatives:
VOC2
would
comply
with
ARARs.
Non-VOC
alternatives:
Non-VOC2 and
Non-VOC4a
would comply
with ARARs.
VOC alternatives:
Risks under NFA would not be acceptable because there is uncertainty
regarding SSG characterization. Risks under VOC2 would be acceptable.
Risks for unrestricted use are within the risk management range and risks
for industrial use are less than the risk management range. Considering the
relatively low risks for residential and industrial use, VOC2 is protective
given the uncertainty related to characterization of SSG.
The long-term effectiveness and permanence of the ICs under VOC2
would depend on the maintenance, monitoring, and enforcement of the
ICs. The criterion for long-term effectiveness and permanence would not
be met under NFA.
Non-VOC alternatives:
Soil risks (excluding arsenic) are less than the risk management range for
both unrestricted use and industrial use; however, the HI is still greater
than 1 for unrestricted use when arsenic is excluded. Risks under Non-
VOC2 are acceptable. Although residual contamination would remain, ICs
and ECs would provide continued protection of human health and surface
water quality.
Non-VOC4a would also be effective and permanent given that post-
excavation soil sampling would be performed to verily that residual
contamination would not impact groundwater. The long-term effectiveness
and permanence of the ICs and ECs under Non-VOC2 would depend on the
maintenance, monitoring, and enforcement of the ICs and ECs. The
criterion for long-term effectiveness and permanence would not be met
under NFA.
VOC alternatives:
NFA and VOC2 would
not provide any
additional reduction
over NFA.
Non-VOC alternatives:
NFA, Non-VOC2 and
Non-VOC4a do not meet
the statutory preference
for treatment.
VOC alternatives:
NFA and VOC2 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse
risks to the environment or
health of the community and
workers.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the environment or
health of the community and
workers. Short-term risks during
excavation (Non-VOC4a) could be
managed.
VOC alternatives:
NFA and
VOC2 are
implementable.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4a are
implementable. Current
site use would be disrupted
during excavation (Non-
VOC4a).
VOC alternatives:
VOC2 = $98,300
Non-VOC alternatives:
Non-VOC2 = $88,000
Non-VOC4ab =
$347,100
100
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiince
with ARARs
Long-term LITectncss ;iikI IViToriiiiiiuc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llroni>h Trciilmcnt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
SA073
VOC alternatives:
There was insufficient SSG data
because no SSG samples were
collected prior to 2017; however, an
interim SSG data gap investigation
was completed in 2017 to confirm the
extent of contamination within the Site
boundaries and included the collection
of two SSG samples at 7 feet bgs.
Chloroform and TCE were detected,
but no VOCs were detected at
concentrations above the IC
compliance levels. Although two SSG
samples were collected during the
2017 sampling, no risks were
calculated and uncertainties regarding
SSG characterization remain. NFA
would not be protective given the lack
of SSG data. VOC2 would effectively
prevent unrestricted use.
Non-VOC alternatives:
There was insufficient soil data as no soil
samples were collected prior to 2017;
however, an interim soil investigation was
completed in 2017 that included the
collection of three surface soil and two
subsurface soil samples from three
locations. Several metals and PAHs were
detected, but only lead and benzo(a)pyrene
concentrations exceeded cleanup levels.
The reporting limit for PCBs was greater
than the cleanup level, so uncertainty
regarding characterization of PCBs
remains. Non-VOC2 withECs would
effectively prevent unrestricted use, given
the uncertainty related to risk and impacts
to surface water quality. NFA would not be
protective of human health given the
uncertainty. NFA would also not be
protective of surface water and
groundwater quality.
VOC
alternatives:
VOC2
would
comply
with
ARARs.
Non-VOC
alternatives:
Non-VOC2
would comply
with ARARs.
VOC alternatives:
An interim SSG data gap investigation was conducted in 2017. No VOCs
were detected at concentrations above the IC compliance levels, but no
risk calculations were conducted for the new data and uncertainties
regarding SSG characterization remain. Risks under VOC2 would be
acceptable. VOC2 is protective given the uncertainty related to
characterization of SSG.
The long-term effectiveness and permanence of the ICs under VOC2
would depend on the maintenance, monitoring, and enforcement of the
ICs. The criterion for long-term effectiveness and permanence would not
be met under NFA.
Non-VOC alternatives:
Non-VOC2 with ECs would be protective of human health as well as of
surface water quality. The risk associated with soil is uncertain, but recent
sampling results indicate that lead and benzo(a)pyrene exceed the cleanup
levels. In addition, the detection limit for PCBs was elevated, so it is still
uncertain if PCBs exceed cleanup levels. Therefore, Non-VOC2 is necessary
to address uncertainty related to PCB concentrations and exceedances of lead
and benzo(a)pyrene.
The long-term effectiveness and permanence of the ICs and ECs under Non-
VOC2 would depend on the maintenance, monitoring, and enforcement of
the ICs and ECs.
VOC alternatives:
NFA and VOC2 do not
meet the statutory
preference for
treatment.
Non-VOC alternatives:
NFA and Non-VOC2 do
not meet the statutory
preference for treatment.
VOC alternatives:
NFA and VOC2 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse
risks to the environment or
health of the community and
workers.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the environment or
health of the community and
workers.
VOC alternatives:
NFA and
VOC2 are
implementable.
Non-VOC alternatives:
NFA and Non-VOC2 are
implementable.
VOC alternatives:
VOC2 = $103,500
Non-VOC alternatives:
Non-VOC2 = $88,000
101
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiiiHT
with ARARs
Long-term LITectncss ;iikI I'crforniiincc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llI'Olll>ll TrCilllllCIlt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
SA077
VOC alternatives:
NFA would not be protective. Although
risks are within the risk management range
for unrestricted use, there is uncertainty
regarding SSG characterization. VOC2
would effectively prevent unrestricted use.
VOC
alternatives:
VOC2 would
comply with
ARARs.
VOC alternatives:
Risks under NFA would not be acceptable because there is uncertainty
regarding SSG characterization. Risks under VOC2 would be acceptable.
Risks for unrestricted use are within the risk management range, and risks
for industrial use are at the low end of the risk management range.
Considering the relatively low risks for residential and industrial use,
VOC2 is protective given the uncertainty related to characterization of
SSG.
The long-term effectiveness and permanence of the ICs under VOC2 would
depend on the maintenance, monitoring, and enforcement of the ICs. The
criterion for long-term effectiveness and permanence would not be met
under.
VOC alternatives:
NFA and VOC2 do not
meet the statutory
preference for treatment.
VOC alternatives:
NFA and VOC2 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse
risks to the environment or
health of the community and
workers.
VOC alternatives:
NFA and VOC2 are
implementable.
Coordination with the
SVE program would be
required.
VOC alternatives:
VOC2 = $108,600
SA078
Non-VOC alternatives:
NFA would be protective of human health
considering risks are within the risk
management range for unrestricted use;
however, NFA would not be protective of
surface water quality. Non-VOC2 with
ECs would effectively prevent unrestricted
use and be protective of surface water
quality.
Non-VOC
alternatives:
Non-VOC2
would comply
with ARARs.
Non-VOC alternatives:
Risks under NFA would not be acceptable because NFA would not be
protective of surface water quality. Risks under Non-VOC2 with ECs
would be acceptable and would protect surface water quality. Risks for
unrestricted use are within the risk management range and risks for
industrial use are at the low end of the risk management range; however,
there are potential impacts to surface water quality.
The long-term effectiveness and permanence of the ICs and ECs under Non-
VOC2 would depend on the maintenance, monitoring, and enforcement of
the ICs and ECs. The criterion for long-term effectiveness and permanence
would not be met under NFA.
Non-VOC alternatives:
NFA and Non-VOC2 do
not meet the statutory
preference for treatment.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the environment or
health of the community and
workers.
Non-VOC alternatives:
NFA and Non-VOC2 are
implementable.
Non-VOC alternatives:
Non-VOC2 = $88,000
SA079
VOC alternatives:
VOC4 would be protective because
volume and concentrations of VOCs would
be reduced. VOC3 would provide
additional protection compared to VOC2.
VOC2 would effectively prevent
unrestricted use; however, given the HI is
greater than 1 for the industrial use
scenario, VOC2 would not be protective of
industrial users. NFA would not be
protective of human health because the risk
for unrestricted use is greater than the risk
management range and the HI is greater
than 1 for both the unrestricted and
industrial use scenarios.
Non-VOC alternatives:
Non-VOC2 would effectively prevent
unrestricted use and be protective of
human health. NFA would not be
protective of human health because the HI
is greater than 1 for the unrestricted use
scenario.
VOC
alternatives:
VOC3 and
VOC4 would
comply with
ARARs.
Non-VOC
alternatives:
Non-VOC2
would comply
with ARARs.
VOC alternatives:
Risks under VOC3 and VOC4 would be acceptable. Risks under VOC2
would be acceptable for unrestricted use; however, VOC2 would not
adequately protect industrial users. Risks under NFA are not acceptable,
and NFA would not be protective of human health. Risks for unrestricted
use are greater than the risk management range and for industrial use are
within the risk management range. The HI is greater than 1 for both the
unrestricted and industrial use scenarios.
The long-term effectiveness and permanence of the ICs under VOC2 would
depend on the maintenance, monitoring, and enforcement of the ICs. The
criterion for long-term effectiveness and permanence would not be met under
NFA.
Non-VOC alternatives:
Risks under NFA would not be acceptable because NFA would not be
protective of human health (the HI is greater than 1 for the unrestricted use
scenario). Risks under Non-VOC2 would be protective. Risks for
unrestricted use are at the upper end of the risk management range and risks
for industrial use are within the risk management range. The HI is greater
than 1 for unrestricted use and less than 1 for industrial use.
The long-term effectiveness and permanence of the ICs under Non-VOC2
would depend on the monitoring and enforcement of the ICs. The criterion
for long-term effectiveness and permanence would not be met under NFA.
VOC alternatives:
Mobility and volume
would be significantly
reduced under VOC4.
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
Non-VOC alternatives:
NFA and Non-VOC2 do
not meet the statutory
preference for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately; however,
there is uncertainty for VOC4
regarding the time required to
achieve industrial use PCGs.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils. VOC4 could require
installation of additional wells but
short- term risks could be managed.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the environment or
health of the community and
workers.
VOC alternatives:
NFA, VOC2, VOC3 and
VOC4 are implementable.
Coordination with the
SVE program would be
required.
Non-VOC alternatives:
NFA and Non-VOC2 are
implementable.
VOC alternatives:
VOC2 = $88,000
VOC3 = $295,000
VOC4 = $302,000
Non-VOC alternatives:
Non-VOC2 = $88,000
102
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiince
with ARARs
Long-term LITectncss ;iikI I'crforniiincc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llroni>h Trciilmcnt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
SA081
VOC alternatives:
VOC4 would be protective for SSG
because volume and concentrations of
VOCs would be reduced. VOC3 would
provide additional protection compared to
VOC2. VOC2 would effectively prevent
unrestricted use, but would not be
protective of industrial users given the
uncertainty associated with characterizing
the entire length of the fuel line. NFA
would not be protective of human health
given that the HI is greater than 1 for the
unrestricted use scenario.
Non-VOC alternatives:
Non-VOC4a and Non-VOC4b would be
protective for soil because TPH would be
physically removed. Non-VOC3 would
be protective. Non-VOC2 with ECs
would be protective of surface water
quality. NFA would not be protective of
human health given that the HI
(excluding arsenic) is greater than 1 for
the unrestricted use scenario.
Also, potential impacts to surface water
and groundwater quality would remain.
VOC
alternatives:
VOC3 and
VOC4 would
comply with
ARARs.
Non-VOC
alternatives:
Non-VOC2,
Non-VOC3,
Non-VOC4a,
and Non-
VOC4b
would comply
with ARARs.
VOC alternatives:
Risks under VOC3 and VOC4 would be acceptable. SSG risks under VOC2
would be acceptable; however, VOC2 may not be protective of industrial
users given the uncertainty associated with characterizing the entire length
of the fuel line. NFA would not be protective of human health given that
the HI is greater than 1 for the unrestricted use scenario. SSG risks are
within the risk management range for both unrestricted use and industrial
use; however, the HI is greater than 1 for the unrestricted use scenario.
The long-term effectiveness and permanence of the ICs under VOC2
would depend on the maintenance, monitoring, and enforcement of the
ICs. The criterion for long-term effectiveness and permanence would not
be met under NFA.
Non-VOC alternatives:
Risks for unrestricted use (excluding arsenic) are within the risk
management range and for industrial use (excluding arsenic) are at the low
end of the risk management range. However, the HI (excluding arsenic)
exceeds 1. NFA would be protective of human health, but potential impacts
to surface water and groundwater quality would remain.
Non-VOC4b would be the most effective and permanent for soil because
levels acceptable for unrestricted use would be achieved by excavation and
offsite disposal. However, Non-VOC3 and Non-VOC4a would also be
effective and permanent given that soil sampling would be performed to
verify that residual contamination would not impact surface water and
groundwater quality. The long-term effectiveness and permanence of Non-
VOC3 would be increased relative to Non-VOC2 with the addition of
bioventing. The long-term effectiveness and permanence of the ICs and ECs
under Non-VOC2 would depend on the maintenance, monitoring, and
enforcement of the ICs and ECs. The criterion for long-term effectiveness
and permanence would not be met under NFA.
VOC alternatives:
Mobility and volume
would be significantly
reduced under VOC4.
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
Non-VOC alternatives:
Only Non-VOC3 would
meet the statutory
preference for treatment.
NFA, Non-VOC2, Non-
VOC4a, and Non-
VOC4b do not meet the
statutory preference for
treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately; however,
there is uncertainty for VOC4
regarding the time required to
achieve industrial use PCGs.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils. VOC4 could require
installation of additional wells, but
short-term risks could be managed.
Non-VOC alternatives:
NFA and Non-VOC2 would
require the least amount of time to
implement for soil, and
contaminated soil would not be
disturbed. Implementation of Non-
VOC2 would entail no significant
adverse risks to the environment or
health of the community and
workers. Short-term risks during
bioventing (Non-VOC3) and
excavation (Non-VOC4a and Non-
VOC4b) could be managed.
VOC alternatives:
NFA, VOC2, VOC3, and
VOC4 are implementable.
Non-VOC alternatives:
NFA, Non-VOC2, Non-
VOC3, Non-VOC4a, and
Non- VOC4b are
implementable; however,
excavation (Non-VOC4a
and Non-VOC4b) may be
more difficult to
implement because
contamination likely
extends to 30 feet bgs and
some of these areas are
located adjacent to
buildings. Current site use
would be disrupted during
excavation (Non-VOC4a
and Non-VOC4b).
VOC alternatives:
VOC2 = $175,700
VOC3 = $283,700
VOC4 = $203,000
Non-VOC alternatives:
Non-VOC2 = $407,000
Non-VOC3 =
$2,068,000
Non-VOC4a =
$5,577,000
Non-VOC4b =
$5,498,000
103
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiince
with ARARs
Long-term LITectncss ;iikI IViToriiiiiiuc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llroni>h Trciilmcnt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
SA086
VOC alternatives:
VOC3 would provide additional
protection compared to VOC2. VOC2
would effectively prevent unrestricted
use. NFA would not be protective of
human health considering that the HI is
greater than 1 for unrestricted use and
given the uncertainty regarding SSG
characterization.
Non-VOC alternatives:
For soil, Non-VOC4b would be protective
because contaminants would be physically
removed. Non-VOC2 with ECs would
protect human health by prohibiting
unrestricted use and would be protective of
surface water quality. NFA would not be
protective considering that the HI is greater
than 1 for unrestricted use and would not
be protective of groundwater and surface
water quality.
VOC
alternatives:
VOC2 and
VOC3 would
comply with
ARARs.
Non-VOC
alternatives:
Non-VOC2 and
Non-VOC4b
would comply
with ARARs.
VOC alternatives:
Risks under VOC2 and VOC3 would be acceptable. Considering the
relatively low risks for residential and industrial use, VOC2 is protective
given the uncertainty related to characterization of SSG. Risks for
unrestricted use are within the risk management range and for industrial
use are less than the risk management range; however, the HI is greater
than 1 for the unrestricted use scenario.
The long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under VOC2 would
depend on the maintenance, monitoring, and enforcement of the ICs. The
criterion for long-term effectiveness and permanence would not be met
under NFA.
Non-VOC alternatives:
Under Non-VOC2, residual contamination would remain; however, ICs
would provide continued protection of human health. Non-VOC2 with ECs
would be protective of surface water quality. Risks for unrestricted use and
industrial use are less than the risk management range; however, the HI is
greater than 1 for the unrestricted use scenario. NFA would not be
protective of human health or of water quality.
Non-VOC4b would be the most effective and permanent because levels
acceptable for unrestricted use would be achieved by excavation and offsite
disposal. The long-term effectiveness and permanence of the ICs and ECs
under Non-VOC2 would depend on the maintenance, monitoring, and
enforcement of the ICs and ECs. The criterion for long-term effectiveness
and permanence would not be met under NFA.
VOC alternatives:
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4b do not meet
the statutory preference
for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately, and
contaminated soil would not be
disturbed.
Implementation of Non-VOC2
would entail no significant adverse
risks to the environment or health of
the community and workers. Short-
term risks during excavation (Non-
VOC4b) could be managed.
VOC alternatives:
NFA, VOC2, and
VOC3 are
implementable.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4b are
implementable. Current
site use would be disrupted
during excavation (Non-
VOC4b).
VOC alternatives:
VOC2 = $113,700
VOC3 = $202,100
Non-VOC alternatives:
Non-VOC2 = $164,200
Non-VOC4bb =
$350,800
104
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiiiHT
with ARARs
Long-term LITectncss ;iikI I'crforniiincc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llI'Olll>ll TrCilllllCIlt
Short-term LITcctncncss
Implementiihility
C'OSI (I'V.tn)
SA094
VOC alternatives:
VOC2 would be protective because
unrestricted use would be prohibited.
NFA would not be protective. Although
risks are within the risk management
range for unrestricted use, there is
uncertainty regarding the SSG
characterization.
Non-VOC alternatives:
NFA would not be protective. Although
risks are within the risk management range
for unrestricted use, NFA would not be
protective of surface water quality. Non-
VOC2 with ECs would effectively prevent
unrestricted use and would be protective of
surface water quality. For soil, Non-
VOC4a would be protective because
contaminants would be physically
removed.
VOC
alternatives:
VOC2
would
comply
with
ARARs.
Non-VOC
alternatives:
Non-VOC2 and
Non-VOC4a
would comply
with ARARs.
VOC alternatives:
Risks are within the risk management range for unrestricted use and at the
low end of the risk management range for industrial use. Risks under
VOC2 would be acceptable. Risks under NFA would not be acceptable
because there is uncertainty regarding SSG characterization. Considering
the relatively low risks for residential and industrial use, VOC2 is
protective given the uncertainty related to characterization of SSG.
The long-term effectiveness and permanence of the ICs under VOC2
would depend on the maintenance, monitoring, and enforcement of the
ICs. The criterion for long-term effectiveness and permanence would not
be met under NFA.
Non-VOC alternatives:
Risks under Non-VOC2 with ECs would be acceptable and this alternative
would be protective of surface water quality. Risks are within the risk
management range for unrestricted use and at the low end of the risk
management range for industrial use. Although NFA would be protective of
human health, NFA would not be protective of surface water quality.
Non-VOC4a would be effective and permanent given that post-excavation
soil sampling would be performed to verify that residual contamination
would not impact groundwater. The long-term effectiveness and
permanence of the ICs and ECs under Non-VOC2 would depend on the
maintenance, monitoring, and enforcement of the ICs and ECs. The
criterion for long-term effectiveness and permanence would not be met
under NFA.
VOC alternatives:
NFA and VOC2 do not
meet the statutory
preference for
treatment.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non-VOC4a do not meet
the statutory preference
for treatment.
VOC alternatives:
NFA and VOC2 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse
risks to the environment or
health of the community and
workers.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately and
contaminated soil would not be
disturbed.
Implementation of Non-VOC2
would entail no significant adverse
risks to the environment or health of
the community and workers. Short-
term risks during excavation (Non-
VOC4a) could be managed.
VOC alternatives:
NFA and
VOC2 are
implementable.
Non-VOC alternatives:
NFA, Non-VOC2, and
Non- VOC4 are
implementable. Current
site use would be disrupted
during excavation (Non-
VOC4a).
VOC alternatives:
VOC2 = $124,100
Non-VOC alternatives:
Non-VOC2 = $88,000
Non-VOC4ab =
$589,400
SA098
VOC alternatives:
NFA would not be protective. Although
risks are within the risk management range
for unrestricted use, there is uncertainty
regarding SSG characterization. VOC3
would be protective, but VOC2 would
effectively prevent unrestricted use.
VOC
alternatives:
VOC2 and
VOC3 would
comply with
ARARs.
VOC alternatives:
Risks under NFA would not be acceptable because there is uncertainty
regarding SSG characterization. Risks under VOC2 and VOC3 would be
acceptable. Risks for unrestricted use are within the risk management
range and for industrial use are at the low end of the risk management
range. Considering the relatively low risks for residential and industrial
use, VOC2 is protective and necessary given the uncertainty related to
characterization of SSG.
The long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the addition
of ECs, which would control migration of soil gas into indoor air. The long-
term effectiveness and permanence of the ICs under VOC2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The criterion for
long-term effectiveness and permanence would not be met under NFA.
VOC alternatives:
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers.
VOC3 would involve limited
disruption of shallow soils.
VOC alternatives:
NFA, VOC2, and VOC3
are implementable.
VOC alternatives:
VOC2 = $103,500
VOC3 = $383,500
105
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo
Protection of 11 inn:in llciilth iinil the
Km iron moil t
('ompliiiiHT
with ARARs
Long-term LITectncss ;iikI I'crforniiincc
Reduction in Toxicity,
Mobility, itiul Volume
'I'llI'Olll>ll TrCilllllCIlt
Short-term LITcctncncss
Iniplcmcnliihility
C'OSI (I'V.tn)
SA 101
VOC alternatives:
Given the uncertainty regarding SSG
characterization, VOC3 and VOC2 would
be protective because unrestricted use
would be prohibited. VOC3 would provide
additional protection compared to VOC2
for industrial users. NFA would not be
protective because there is uncertainty
regarding the SSG characterization.
Although two SSG samples were collected
during the 2017 sampling, no revised risks
were calculated and uncertainties regarding
SSG characterization remain. In addition,
chloroform concentrations detected during
the 2017 sampling were greater than the IC
compliance level.
VOC
alternatives:
VOC2 and
VOC3 would
comply with
ARARs.
VOC alternatives:
There are no risk calculations available because no SSG samples were
collected prior to 2017. Although two SSG samples were collected during
the 2017 sampling, no risks were calculated and uncertainties regarding
SSG characterization remain. In addition, chloroform concentrations
detected during the 2017 sampling were greater than the IC compliance
level. Risks under VOC3 and VOC2 would be acceptable, although
VOC3 would provide additional protect for industrial users. NFA would
not be protective of human health given the uncertainty regarding SSG
characterization and chloroform exceedances. VOC3 and VOC2 would
be protective of human health given the uncertainty related to
characterization of SSG.
The long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the addition
of ECs, which would control migration of soil gas into indoor air. The long-
term effectiveness and permanence of the ICs under VOC2 would depend on
the maintenance, monitoring, and enforcement of the ICs. The criterion for
long-term effectiveness and permanence would not be met under NFA.
VOC alternatives:
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would
be effective immediately.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils.
VOC alternatives:
NFA, VOC2, and VOC3
are implementable.
VOC alternatives:
VOC2 = $103,500
VOC3= $196,000
SA 102
VOC alternatives:
VOC4 would be protective because
volume and concentrations of VOCs
would be reduced. VOC3 would provide
additional protection compared to VOC2.
VOC2 would effectively prevent
unrestricted use, but would not protect
industrial users because the risk for
industrial use is greater than the risk
management range. NFA would not be
protective considering risks are greater
than the risk management range for both
industrial and unrestricted use.
Non-VOC alternatives:
Non-VOC2 with ECs would protect human
health by prohibiting unrestricted use and
would be protective of surface water
quality. NFA would be protective of
human health considering the risk
(excluding arsenic) is within the risk
management range for unrestricted use, but
would not be protective of surface water
quality.
VOC
alternatives:
VOC3 and
VOC4 would
comply with
ARARs.
Non-VOC
alternatives:
Non-VOC2
would comply
with ARARs.
VOC alternatives:
Risks under VOC3 and VOC4 would be acceptable. Risk under VOC2
would not be acceptable due to the risk to industrial users. Risk under
NFA would not be acceptable. Risks for both industrial and unrestricted
use are greater than the risk management range. The HI is greater than 1
for both the industrial and unrestricted use scenarios.
The long-term effectiveness and permanence of the ICs under VOC2,
VOC3, and VOC4 would be nearly equal; however, the long-term
reliability and permanence of VOC4 would be increased relative to VOC3
with the addition of SVE, which would physically remove VOCs. The
long-term effectiveness and permanence of the ICs under VOC2 and
VOC3 would be nearly equal; however, the long-term reliability and
permanence of VOC3 would be increased relative to VOC2 with the
addition of ECs, which would control migration of soil gas into indoor air.
The long-term effectiveness and permanence of the ICs under VOC2
would depend on the maintenance, monitoring, and enforcement of the ICs.
The criterion for long-term effectiveness and permanence would not be
met under NFA.
Non-VOC alternatives:
Risk (excluding arsenic) under NFA would be acceptable; however, NFA
would not be protective of surface water quality. Under Non-VOC2,
residual contamination would remain; however, ICs would provide
continued protection of human health. Non-VOC2 with ECs would be
protective of surface water quality. Risks for unrestricted use (excluding
arsenic) are within the risks management range and for industrial use
(excluding arsenic) are below the risk management range.
The long-term effectiveness and permanence of the ICs and ECs under non-
VOC2 would depend on the maintenance, monitoring, and enforcement of
the ICs and ECs.
VOC alternatives:
Mobility and volume
would be significantly
reduced under VOC4.
NFA, VOC2, and VOC3
do not meet the statutory
preference for treatment.
Non-VOC alternatives:
NFA and Non-VOC2 do
not meet the statutory
preference for treatment.
VOC alternatives:
NFA, VOC2, and VOC3 would be
effective immediately; however,
there is uncertainty for VOC4
regarding the time required to
achieve industrial use PCGs.
Implementation of VOC2 would
entail no significant adverse risks to
the environment or health of the
community and workers. VOC3
would involve limited disruption of
shallow soils. VOC4 could require
installation of additional wells but
short- term risks could be managed.
Non-VOC alternatives:
NFA and Non-VOC2 can be
implemented immediately, and
contaminated soil would not be
disturbed.
Implementation of Non-VOC2
would entail no significant adverse
risks to the environment or health of
the community and workers.
VOC alternatives:
NFA, VOC2, VOC3, and
VOC4 are implementable.
Non-VOC alternatives:
NFA and Non-VOC2 are
implementable.
VOC alternatives:
VOC2 = $88,000
VOC3 = $173,000
VOC4 = $651,000
Non-VOC alternatives:
Non-VOC2 = $150,700
Notes: 1) Institutional controls alone would not directly address potential threats to groundwater; however, the threat to groundwater via VOCs is addressed under the VOC Groundwater ROD. Alternative VOC2 would not comply with ARARs for SVS sites, where risks for the industrial use scenario exceed (or
potentially exceed) the upper end of the risk range,
a) State and community acceptance are modifying criteria that will be evaluated during the Proposed Plan public comment period.
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b) Cost escalated from 2012 to 2015 using a real discount rate of 1.4% according to the Office of Management and Budget (OMB) Circular No. A-94 (OMB 2015). All other costs were taken from the FOSS RICS/FS and SVS RICS/FS, which use a discount rate of 2.7 percent, taken from Appendix C of
the Office of Management and Budget Circular A-94 (January 2008).
* Indicates the costs and volumes for the alternative have been revised based on the completion of the SVS and Building 252 Radiological NTCRA.
AOC
area of concern
ARAR
applicable or relevant and appropriate requirements
bgs
below ground surface
CS
confirmed site
EC
engineering control
HI
Hazard Index
IC
institutional control
IC (#)
investigation cluster (used with a numeral to identify SVE investigation/cleanup areas)
NFA
no further action
PCG
preliminary cleanup goal
PRL
potential release location
PV30
Present value worth 30-year costs; no costs are associated with No Further Action alternative
SA
study area
SSG
shallow soil gas
SVE
soil vapor extraction
TPH
total petroleum hydrocarbons
TPH-D
diesel-range total petroleum hydrocarbons
TPH-G
gasoline-range total petroleum hydrocarbons
VOC
volatile organic compound
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
2.11 PRINCIPAL THREAT WASTES
Principal threat wastes are those hazardous substances, pollutants, or contaminants that act as a reservoir
for migration of contamination and are considered to be highly toxic or highly mobile, which generally
cannot be reliably contained or would present a significant risk to human health or the environment should
exposure occur. The NCP establishes an expectation that EPA will use treatment to address the principal
threats posed by a site wherever practicable.
The contaminants at the 45 FOSET #2 Group 2 Action Sites are not highly mobile and could be reliably
contained; therefore, they do not constitute principal threat wastes.
2.12 SELECTED REMEDIES
EPA, in consultation with DTSC and the Central Valley Water Board, is selecting the combination of
remedial alternatives as described below for the FOSET #2 Group 2 Action Sites. These remedial
alternatives were presented in the Proposed Plan, and EPA has determined that the selected remedies are
protective of human health and the environment, given the current and reasonably anticipated future land
use of industrial or industrial/commercial. The selected IC measures are necessary to protect public health
and the environment from the residual contaminants at the sites.
The selected remedies are presented in Table 1-2 and are presented in site-specific write-ups in Attachment
D. Each of the selected remedies is described in detail in Sections 2.12.1 through 2.12.3. Because ICs and
ECs are a component of most of the remedies, they are discussed in detail in Sections 2.12.5 and 2.12.6,
respectively, following the remedy descriptions.
2.12.1 Alternative VOC2
Under Alternative VOC2, restrictions on residential/sensitive use will be used to eliminate or limit exposure
pathways for VOCs to human receptors and the environment. Alternative VOC2 results in restricted land
use. The use restrictions will be implemented through provisions in the property deeds and in SLUCs. The
restrictions will prohibit the use of the sites for residential purposes, hospitals for human care, public or
private schools for persons under 18 years of age, or day-care centers for children. Annual monitoring to
determine if property use has conformed to the ICs and use restrictions is part of this alternative.
2.12.2 Alternative VOC3
In addition to the selected restrictions in Alternative VOC2, Alternative VOC3 includes ECs requiring
either mitigation for vapor intrusion or sampling to show acceptable risk for any future construction or
significant remodeling of existing buildings (e.g., remodeling that requires replacing major portions of the
foundation or floor). Alternative VOC3 results in restricted land use. These ECs will be implemented
through provisions in the property deeds and in SLUCs. Annual monitoring to determine if property use
has conformed to the ICs or use restrictions is part of this alternative.
The restriction will prohibit construction or significant remodeling unless vapor controls are installed to
mitigate the risk from vapor intrusion. Vapor controls are required unless new sampling indicates that SSG
IC compliance levels in Table 2-5 are not exceeded, or a risk assessment based on new sampling is
performed to evaluate the risk posed under CERCLA and the NCP, as determined by EPA, in consultation
with DTSC and the Central Valley Water Board. The selection of the controls to be implemented will be
based on whether the controls are to be implemented on an existing building or future construction. For
existing buildings, the building design, foundation type (e.g., slab, raised, etc.), and function of the building
(e.g., warehouse, office building, etc.) will be used to determine the most appropriate type of EC in the
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
approved work plan). For new buildings, a vapor barrier is assumed to be the most appropriate type of EC;
however, this will ultimately be determined during the building design phase and approved by EPA, in
consultation with DTSC and the Central Valley Water Board.
2.12.3 Alternative Non-VOC2
Under Alternative Non-VOC2, restrictions on residential/sensitive use will be used to eliminate or limit
exposure pathways for non-VOCs to human receptors and the environment. Alternative Non-VOC2 results
in restricted land use. The use restrictions will be implemented through provisions in the property deeds
and in SLUCs. The restrictions will prohibit the use of the sites for residential purposes, hospitals for
human care, public or private schools for persons under 18 years of age, or day-care centers for children.
Annual monitoring to determine if property use has conformed to the ICs and use restrictions is part of this
alternative.
If, based on the sampling for specific sites as identified in Attachment D during the Remedial Design phase,
the average residual concentrations in the 0- to 1-foot-bgs interval exceed cleanup levels for protection of
surface water, then a water quality assessment, ECs (e.g., maintaining the existing surface cover or sediment
traps and quarterly monitoring), ICs (i.e., digging restrictions), and/or monitoring will be required to address
potential impacts to surface water. If monitoring is required, it would be conducted over a period of at least
three years or as long as levels protective of surface water quality as shown in Table 2-4 are exceeded. ICs
include use restrictions to prevent residential and sensitive use (e.g., hospitals, public or private schools for
persons under 18 years of age, daycares, etc.), protection of surface covers or sediment traps, and digging
restrictions to prevent soil disturbing activities (e.g., digging, excavation, grading, removal, trenching,
filling, or other earth movement) that do not comply with the McClellan Park Soils Management Manual
for Transfer Parcels that is in effect at the time of proposed soil or surface cover disturbing activities. The
selected ICs will be implemented through provisions in the property deeds and in SLUCs. Table 2-7
displays the applicable ICs for each site. The most appropriate type of EC will be determined in the
EPA/State-approved RAWP. Table 2-8 displays the applicable ECs for each site. Site-specific discussions
of ECs required under Alternative Non-VOC2 are provided in Attachment D.
2.12.4 Alternative Non-VOC4a
Under Alternative Non-VOC4a, contaminated soil and/or sediment above the applicable cleanup levels in
Table 2-3 will be excavated, and the excavated soil will be transported to an appropriate facility for disposal.
Pre-excavation sampling may be conducted to refine the excavation area boundaries prior to construction
work. Excavation will not be required in areas where validated pre-excavation sampling results are below
cleanup levels. Alternative Non-VOC4a uses cleanup levels for restricted land use (i.e., industrial land
use), and all soil containing concentrations of contaminants above industrial use cleanup levels (which
could include cleanup levels for protection of surface water and groundwater) will be removed.
If, based on the sampling for specific sites as identified in Attachment D during the Remedial Design phase,
the average residual concentrations in the 0- to 1-foot-bgs interval exceed cleanup levels for protection of
surface water, then a water quality assessment, ECs (e.g., maintaining the existing surface cover or sediment
traps and quarterly monitoring), ICs (i.e., digging restrictions), additional excavation, and/or monitoring
will be required to address potential impacts to surface water. If monitoring is required, it would be
conducted over a period of at least three years or as long as levels protective of surface water quality as
shown in Table 2-4 are exceeded. ICs include use restrictions to prevent residential and sensitive use (e.g.,
hospitals, public or private schools for persons under 18 years of age, daycares, etc.), protection of surface
covers or sediment traps, and digging restrictions to prevent soil disturbing activities (e.g., digging,
excavation, grading, removal, trenching, filling, or other earth movement) that do not comply with the
McClellan Park Soils Management Manual for Transfer Parcels that is in effect at the time of proposed soil
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
or surface cover disturbing activities. The selected ICs will be implemented through provisions in the
property deeds and in SLUCs. Table 2-7 displays the applicable ICs for each site. The most appropriate
type of EC will be determined in the EPA/State-approved RAWP. Table 2-8 displays the applicable ECs
for each site. Site-specific discussions of ECs required under Alternative Non-VOC4a are provided in
Attachment D.
Contaminated soil at concentrations exceeding cleanup levels will be physically excavated using
conventional earthmoving equipment. The estimated extent of excavation for each site is shown on the
site-specific figures in Attachment D and in Table 2-1. The type and quantity of equipment used will
depend on the depth, areal extent, and volume of soil requiring removal. Field screening and/or onsite
laboratory analysis might be used to guide excavation. Site controls such as fencing, signage, and security
will be implemented as necessary during the remedial action. During excavation, stormwater runoff will
be controlled using best management practices (e.g., staked straw waddles, silt fence curtains) to ensure
that discharges of stormwater do not negatively impact surrounding surface water.
Following initial excavation, confirmation sampling will be conducted to verify that cleanup levels have
been achieved. The details of this confirmation sampling, including sampling locations, sampling
frequency, specific analytical methods, and acceptable confirmation sampling results, will be provided in
the work plans associated with the Remedial Design phase of the project. If the analytical results indicate
that contamination has been adequately removed, then the excavation void will be backfilled with clean
soil. Otherwise, excavation will continue until cleanup levels are met. Verification sampling of the backfill,
including sampling frequency, analytical methods, and acceptable results, will be provided in the work plan
associated with the Remedial Design phase of this project. Backfill material used as cover soil (0 to 1 foot
bgs) will be required to meet the screening levels for protection of surface water.
Excavated material will be segregated to remove drums, containers, saturated wastes/sludges (i.e., wastes
containing less than 50 percent solids), and other incompatible materials for disposal at an appropriate
facility. The details of the characterization sampling that will be performed on this material and the
proposed disposal or recycle facility options will be provided in the work plan associated with the Remedial
Design phase of this project. Segregation and any preparation required for transportation offsite (e.g.,
overpacking of drums) will be performed in a dedicated area at each site during excavation. The segregation
and preparation area will be engineered to ensure that all contaminated material is contained. The remaining
material (presumably mostly soil) would be stockpiled.
2.12.5 Institutional Controls
ICs are a component of all the selected remedies. The intent of the ICs is to limit or eliminate exposure
pathways to humans by prohibiting certain uses of the property.
The selected use restrictions described in Table 2-7 will be implemented in the deeds of the property and
in SLUCs recorded on the property, if they have not already been implemented as described below. The
SLUCs run with the land and are binding on the current and future property owners. The SLUCs are
enforceable by DTSC and the Central Valley Water Board, and by EPA as a third-party beneficiary.
The performance objectives for ICs are as follows:
• Prohibit the development and use of the property for residential housing, hospitals, public or private
schools for persons under 18 years of age, and childcare facilities;
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• Prohibit digging except in accordance with the approved McClellan Park Soils Management
Manual for Transfer Parcels that is in effect at the time of proposed soil or surface cover disturbing
activities; and
• Require construction of new buildings in a manner that would mitigate unacceptable risk through
installation of vapor intrusion controls or install vapor intrusion controls in existing buildings that
will be modified to mitigate unacceptable risk.
• Prevent removal of any surface cover that is part of the selected remedy, including but not limited
to asphalt, pavement, gravel, building foundations, and landscaping, or if surface cover is removed,
replacement of such surface cover with an equivalent cover, or installation and monitoring of
sediment traps. Alternatively, sampling and risk assessment may be performed to determine if
levels of COCs remain that exceed surface water quality protection levels, as listed in Table 2-4.
The site feature maps for each site in Attachment D show the remedy location and the associated IC
compliance boundaries and buffers. The 100-foot buffer zone can be reduced or eliminated in the future if
there is SSG data that demonstrates there is no SSG contamination above the IC compliance levels in an
area.
The selected ICs for each FOSET #2 Group 2 Action Site are listed in Table 2-7, while the ECs and
monitoring for each FOSET #2 Group 2 Action Site are listed in Table 2-8.
2.12.5.1 Existing ICs
Some ICs are already in place on the property because they were put in place at the time the property was
transferred by the Air Force. Use restrictions described in the FOSET based on the existing conditions at
the property were incorporated into the deeds for the transferred parcels. In addition, at the time of transfer,
the new property owner, MBP, recorded SLUCs containing the same use restrictions. The existing
restrictions specify that the property shall not be put to any of the following uses:
1) A residence, including any mobile home or factory built housing, used as residential human
habitation;
2) A hospital for humans;
3) A public or private school for persons under 18 years of age;
4) A day care center for children;
5) Any use in a manner that causes the covering or disturbing of groundwater monitoring wells or that
restricts access to groundwater monitoring wells;
6) Any use that includes construction of any well or extraction of groundwater for any purposes other
than monitoring or treatment of groundwater or that would cause the surface application or injection
of water or other fluids, unless approved by EPA, DTSC, and Central Valley Water Board;
7) Any use that would disturb or limit access to any equipment or systems associated with
groundwater or soil vapor extraction remediation or monitoring;
8) Any use that would restrict investigation activities, remedial actions or long term maintenance and
operations.
Furthermore, pursuant to the federal deed and SLUC, no activities at the FOSET #2 Group 2 Action Sites,
except response actions pursuant to the AoC (EPA, 2013) or FFA Amendment (AFRPA, 2011), shall
disturb the soil unless conducted in accordance with the approved McClellan Park Soils Management
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Manual for Transfer Parcels that is in effect at the time of proposed soil or surface cover disturbing
activities. Any soils brought to the surface as a result are required to be managed in accordance with all
applicable provisions of state and federal law.
Following the implementation of the selected remedies, some or all of the use or activity restrictions may
no longer be necessary to protect human health and the environment.
2.12.5.2 Selected ICs
The use restrictions selected in this ROD for each site are listed in Table 2-7.
Sensitive Use Restriction
For those sites at which the sensitive use restriction is selected, the SLUC and deed shall specify that the
property shall not be put to any of the following uses:
1) A residence, including any mobile home or factory built housing, used as residential human
habitation;
2) A hospital for humans;
3) A public or private school for persons under 18 years of age; and
4) A day care center for children.
Digging and Protection of Surface Cover Restriction
For those sites at which the digging and protection of surface cover restriction is selected, the SLUC and
deed shall contain the following use restriction:
All soil disturbing activities (e.g., digging, excavation, grading, removal, trenching, filling, or other earth
movement) and surface cover removal activities (e.g., removal of any surface cover that is part of the
selected remedy, including but not limited to asphalt, pavement, gravel, building foundations, and
landscaping) shall be prohibited, except those undertaken in accordance with the McClellan Park Soils
Management Manual for Transfer Parcels that is in effect at the time of proposed soil or surface cover
disturbing activities. Normal landscaping and lawn maintenance activities are excluded from this
restriction.
Vapor Intrusion Restriction
For those sites at which the vapor intrusion restriction is selected, the SLUC and deed shall contain the
following use restriction:
Any (i) new, enclosed structure on the property, or (ii) any modification to an existing enclosed structure
on the property that disturbs the soil and/or building slab (e.g., digging, excavation, grading, removal,
trenching, filling, or other earth movement), must be designed, constructed, or modified in a manner that
would mitigate unacceptable risk from vapor intrusion (e.g., through installation of a vapor intrusion barrier,
vapor collection system, and/or other appropriate EC), or the property user shall evaluate the potential for
such unacceptable risk prior to the erection of any new enclosed structure (or modification to an existing
structure as described above) in the same area, and include mitigation of the vapor intrusion in the
design/construction ofthe structure priorto occupancy, if an unacceptable risk is posed (i.e., IC compliance
levels are exceeded) as determined by DTSC and EPA. The property user shall provide any related reports
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
evaluating risk from vapor intrusion to DTSC and EPA for this determination and must obtain prior written
approval from DTSC and EPA for any ECs proposed.
Protection of Remedy Components Restriction
For all sites at which the protection of remedy components restriction is selected, the SLUC and deed shall
include the following:
Any interference with the following is prohibited: existing infrastructure such as groundwater treatment
systems, SVE systems, monitoring and extraction wells, and associated piping. Activities are prohibited
that would inject, percolate, or allow infiltration of water/other fluids into the groundwater (e.g.,
construction or creation of any groundwater recharge area, percolation ponds, unlined surface
impoundments, trenches, or irrigation) to the extent that the injection/infiltration of water/other fluids might
affect groundwater flow direction or gradient. Normal watering to support landscaping is excluded from
this restriction. For each site at which the existing use restrictions in the deed and SLUCs are consistent
with the selected use restrictions, no additional action will be necessary to implement those ICs. For those
sites at which the existing use restrictions are not consistent with the selected remedies the SLUCs and
deeds will be modified to implement the selected use restrictions.
ICs shall be maintained until the concentration of hazardous substances in the soil and shallow soil gas are
at concentrations that allow for unrestricted use and unlimited exposure, as listed in Tables 2-3, 2-4, and
Table 2-5. The ICs will be monitored to ensure that they remain in place and are effective and will be
further evaluated in the Five-Year review for the sites. The existing SLUCs and a Memorandum of
Agreement entered into by MBP and DTSC require MBP or the current owner to conduct annual inspections
and submit inspection reports regarding the use restrictions. In addition, pursuant to the 2013 AoC, MBP
will prepare an Institutional Controls Implementation and Assurance Plan that, once approved by EPA, in
consultation with DTSC and the Central Valley Water Board, will describe the process and requirements
for any additional IC implementation pursuant to this ROD, and monitoring and enforcement processes for
the ICs.
Table 2-7 Summary of Selected Institutional Controls
Silo II)
Selected Institutional C ontrols
Sensitne I se
Restrict ion
\ apor
Intrusion
Restriction
Protection of Remedy
Components
Restriction
Digging and Protection
of Surface (o\er
Restriction
Alternative VOC2 - ICs to Restrict Land Use and
Alternative Non-VOC2- ICs to Restrict Land Use, ECs, and Monitoring
CS P-005
X
X
X
SA 038
X
X
X
SA 040
X
X
X
SA 043
X
X
X
SA 047
X
X
X
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Site II)
Selected Institutional Controls
Sensili>e I so
Restriction
\ apor
Intrusion
Restriction
Protection of Remedy
Components
Restriction
Digging and Protection
of Surface (mer
Restriction
SA 059
X
X
X
SA 071
X
X
X
SA 073
X
X
X
SA 086
X
X
X
SA 094
X
X
X
Alternative VOC2 - ICs to Restrict Land Use and
Alternative Non-VOC4a- Excavation and Disposal and ICs to Restrict Land Use
PRL T-015
X
X
X
Alternative VOC2- ICs to Restrict Land Use
CS T-059
X
X
PRL P-003
X
X
PRL S-037
X
X
SA 037
X
X
SA 048
X
X
SA 068
X
X
SA 077
X
X
SA 098
X
X
Alternative VOC3 - ICs to Restrict Land Use and ECs to Mitigate Shallow Soil Gas
Contamination and Alternative Non-VOC2 - ICs to Restrict Land Use, ECs, and Monitoring
AOC 325
X
X
X
X
CS P-006
X
X
X
X
PRL L-001
(F2)
X
X
X
X
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site II)
Selected 1 n si it ut ion n 1 Controls
Sensili>e I so
Rest rid ion
\ apor
Intrusion
Restriction
Protection of Remedy
Components
Restriction
Digging and Protection
of Surface (mer
Restriction
PRL L-002
X
X
X
X
PRL L-003
(F2)
X
X
X
X
PRL T-031
X
X
X
X
PRL T-033
X
X
X
X
SA 079
X
X
X
X
SA 102
X
X
X
X
Alternative VOC3 - ICs to Restrict Land Use and ECs to Mitigate Shallow Soil Gas
Contamination and Alternative Non-VOC4a - Excavation and Disposal and ICs to Restrict Land
Use
PRL L-004
X
X
X
X
PRL S-022 &
SA 069
X
X
X
X
SA 081
X
X
X
X
Alternative VOC3 - ICs to Restrict Land Use and ECs to Mitigate Shallow Soil Gas
Contamination
CS S-021
X
X
X
CS S-027
X
X
X
CS T-037
X
X
X
PRL L-005
(F2)
X
X
X
PRL P-004
X
X
X
SA 044
X
X
X
SA 053
X
X
X
SA 058
X
X
X
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Silo II)
Selected Institutional C ontrols
Sonsitne I se
Restrict ion
\ apor
Intrusion
Restriction
Protection of Remedy
Components
Restriction
Digging and Protection
of Surface ("o\er
Restriction
SA 067
X
X
X
SA 101
X
X
X
Alternative Non-VOC2- ICs to Restrict Land Use, ECs, and Monitoring
PRL P-001
X
X
X
PRL T-019
X
X
X
SA 078
X
X
X
X
Component to be implemented as necessary by MBP under this ROD.
AOC
area of concern
CS
confirmed site
EC
engineering control
F2
portion of the IRP site within FOSET #2
IC
institutional control
ID
identification
PRL
potential release location
SA
study area
VOC
volatile organic compound
Engineering Controls
ECs are a component of Alternatives VOC3, Non-VOC2, and Non-VOC4a as indicated in Table 2-8. For
Alternative VOC3, ECs include vapor barriers, gas collection, or ventilation. For Alternatives Non-
VOC2 and Non-VOC4a, ECs may include maintaining surface cover and sediment traps or monitoring.
The performance objectives for ECs are as follows:
• Maintain the integrity of surface cover to protect surface water quality. Where there are no
surface covers, trap sediment to protect surface water quality;
• Install and maintain vapor barriers or other vapor controls to protect workers under the
industrial/commercial reuse scenario until concentrations are below the SSGIC compliance
levels (Table 2-5).
Specific descriptions of the ECs are included in the sections below.
2.12.6.1 Vapor Barrier
Vapor barriers are impermeable membranes placed over contaminated soils that are specially designed to
limit VOC exposure pathways to human and ecological receptors. Vapor barriers are made from various
materials, which may include high-density polyethylene, polyvinyl chloride, chlorosulphonated
polyethylene, neoprene, butyl rubber, and elasticized polyolefin. Vapor barriers can be applied as solid
liners or sprayed on in liquid form. Spray-on vapor barriers consist of a rubberized asphalt emulsion that
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solidifies when exposed to ambient air. New building construction often requires the installation of a
vapor barrier when the threat of soil gas infiltration exists. For new construction, the vapor barriers are
applied beneath the building foundation. For retrofit of existing buildings with a slab-on-grade
foundation, either the slab may be removed to allow for installation of the barrier and then reinstalled, or
the vapor barrier may be applied directly to the slab, with the addition of a shallow slab cover for
protection. Land use restrictions will be necessary at each site containing a vapor barrier to prevent
damage to the barrier and the creation of exposure pathways.
2.12.6.2 Gas Collection
Gas collection systems consist of a network of perforated piping situated within a layer of permeable
material (e.g., gravel) just below the foundation of a building. The piping is connected to a vent pipe that
typically extends vertically up to a point at or slightly above the height of the building. VOCs emanating
from contaminated soil beneath the building collect within the piping and are discharged to the
atmosphere through the vent pipe. Gas collection systems are specifically designed to limit VOC
intrusion into indoor air. The systems can operate passively where driven primarily by diffusion; VOCs
collect within the piping and slowly dissipate to the atmosphere through the vent pipe. The systems can
also be designed to operate actively, where a pump is used to create a vacuum within the piping that
actively collects VOCs and forcibly discharges them to the atmosphere. Gas collection systems are
typically installed at the time of new building construction; however, the retrofit of existing buildings
may also be possible. Land use restrictions will be necessary at each site containing a gas collection
system to prevent damage to the system and the creation of exposure pathways.
2.12.6.3 Ventilation
Ventilation systems use fans to dilute the air within a building. Ventilation systems can be designed and
used to prevent or minimize the migration of VOCs into indoor air (i.e., positive pressure systems), and/or
to dilute VOCs within the indoor air. Positive pressure ventilation systems are designed to create and
maintain pressure within the building at a level slightly higher than ambient. Fresh air is drawn from
outside the building, filtered, and then circulated within the building. The higher pressure within the
building forces air outward through openings in the building such as cracks in the foundation. The
positive pressure and outward movement of air prevents or minimizes the potential for VOCs emanating
from contaminated soil to enter the building. Positive pressure systems work most effectively in
buildings that are typically sealed (e.g., office buildings) and do not have access points that are routinely
left open (e.g., loading docks).
Negative pressure systems are designed to create a slight negative pressure within the building. Air is
constantly withdrawn from the inside of the building and discharged to the outside. The constant air
movement flushes the building and removes VOCs from indoor air. Negative pressure systems typically
are more effective in buildings with multiple doors and windows that are routinely left open. Ventilation
systems are routinely installed during new construction. Ventilation systems can also be installed or
upgraded in existing buildings.
2.12.6.4 Surface Cover
Surface cover would consist of maintaining landscaping or existing hard surfaces such as concrete,
asphalt, or building foundations to prevent direct contact with contaminated soil, or to prevent erosion and
associated impacts to surface water. Surface cover must be maintained where contaminants remain at
concentrations exceeding the levels for protection of water quality. If the existing surface cover is
removed, sampling must be done to determine if a surface cover must be restored or if a sediment trap and
sediment monitoring are required. This EC is implemented with the IC for protection of surface cover.
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2.12.6.5 Sediment Collection
Sediment collection would use engineered methods to control and trap sediment where contaminants
remain at concentrations in surface soil (0-1 foot bgs) that exceed the levels for protection of water
quality. Sediment collection methods involve the installation of pre-fabricated sediment traps to collect
sediment and prevent it from reaching sensitive surface water features such as creeks. Monitoring and
maintaining the sediment traps are required.
Table 2-8 Summary of Selected Engineered Controls and Monitoring
Silo II)
Engineering C ontrols
Monitoi'ing
\ apor
Barrier
(las
Collodion
Ventilation
Maintain
Existing
Surface
Cover
Sediment
Traps and
Collection
Surl'ace Water
and/or Sediment
Trap
Monitoring
Alternative VOC2 - ICs to Restrict Land Use and Alternative Non-VOC2 - ICs to Restrict Land
Use, ECs, and Monitoring
CS P-005
--
--
--
*
--
--
SA 038
--
--
--
*
--
~
SA 040
--
--
--
*
~
--
SA 043
--
--
--
--
~
~
SA 047
--
--
~
*
~
~
SA 059
--
--
~
*
~
~
SA 071
--
--
~
*
--
~
SA 073
--
--
~
--
~
--
SA 086
--
--
--
*
~
~
SA 094
--
--
~
*
~
~
Alternative VOC2- ICs to Restrict Land Use and Alternative Non-VOC4a- Excavation and
Disposal and ICs to Restrict Land Use
PRL T-015
--
--
~
*
~
~
Alternative VOC2 - ICs to Restrict Land Use
CS T-059
--
--
~
~
--
~
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site II)
Engineering Controls
Moniloi'ing
\ apor
Harrier
Gas
Collection
Ventilation
Maintain
Existing
Surface
C 'o\ or
Sediment
Traps and
Collection
Surface Water
and/or Sediment
Trap
Monitoring
PRL P-003
--
--
--
--
--
--
PRL S-037
--
--
--
--
--
~
SA 037
--
--
~
~
--
~
SA 048
~
~
--
~
~
~
SA 068
~
~
~
~
--
~
SA 077
--
~
~
--
~
--
SA 098
~
--
~
~
~
~
Alternative VOC3 - ICs to Restrict Land Use and ECs to Mitigate Shallow Soil Gas
Contamination and Alternative Non-VOC2- ICs to Restrict Land Use, ECs, and Monitoring
AOC 325
X
X
X
*
~
~
CS P-006
X
X
X
*
~
~
PRL L-001
(F2)
X
X
X
*
--
~
PRL L-002
X
X
X
*
~
--
PRL L-003
(F2)
X
X
X
*
~
~
PRL T-031
X
X
X
*
~
~
PRL T-033
X
X
X
*
~
~
SA 079
X
X
X
*
--
~
SA 102
X
X
X
*
~
--
Alternative VOC3 - ICs to Restrict Land Use and ECs to Mitigate Shallow Soil Gas
Contamination and Alternative Non-VOC4a - Excavation and Disposal and ICs to Restrict Land
Use
PRL L-004
X
X
X
*
~
~
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site II)
Engineering Controls
Moniloi'ing
\ apor
Harrier
(las
Collection
Ventilation
Maintain
Existing
Surface
C <>\ or
Sediment
Traps and
Collection
Surface Water
and/or Sediment
Trap
Monitoring
PRL S-022 &
SA 069
X
X
X
~
--
~
SA 081
X
X
X
*
~
~
Alternative VOC3 - ICs to Restrict Land Use and ECs to Mitigate Shallow Soil Gas
Contamination
CS S-021
X
X
X
--
--
~
CS S-027
X
X
X
~
~
~
CS T-037
X
X
X
~
~
~
PRL L-005
(F2)
X
X
X
~
~
--
PRL P-004
X
X
X
--
~
~
SA 044
X
X
X
~
--
~
SA 053
X
X
X
~
~
~
SA 058
X
X
X
~
~
~
SA 067
X
X
X
~
~
--
SA 101
X
X
X
--
~
~
Alternative Non-VOC2 - ICs, ECs, and Monitoring
PRL P-001
"
"
"
*
--
~
PRL T-019
"
"
"
*
~
~
SA 078
"
"
"
*
~
~
X
One or more components to be implemented to mitigate SSG contamination.
*
Component to be implemented under this ROD.
-
Engineered Controls not applicable to the specified site.
AOC
area of concern
CS
confirmed site
EC
engineered control
F2
portion of the IRP site within FOSET #2
IC
institutional control
ID
identification
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PRL potential release location
SA study area
VOC volatile organic compound
2.12.7 Summary of the Estimated Remedy Costs
The cost summary presented in Table 2-9 is based on information provided in the FS documents and FS
Addendums, where complete cost details can be found (CH2MHill, 2011 and 2012; EPA, 2016b and
2016c). The information in this cost estimate summary table is based on the best available information
regarding the anticipated scope of the selected remedial alternatives. Changes in the cost elements are
likely to occur as a result of new information and data collected during the engineering design of the
remedial alternative. Changes may be documented in the form of a memorandum in the Administrative
Record file, an Explanation of Significant Difference, or a ROD amendment. This is an order-of-magnitude
engineering cost estimate that is expected to be within +50 to -30 percent of the actual project cost. The
estimated costs are based on the selected remedial alternatives for each of the FOSET #2 Group 2 Action
Sites (Table 1-2) and the estimated remedy costs (Table 2-6).
Table 2-9 Summary of Estimated Selected Remedy Costs
Remedial Alternative
Total Cost (PW30) ($)
Alternative VOC2
$1,981,200
Alternative VOC3
$6,320,200
Alternative Non-VOC2
$2,570,900
Alternative Non-VOC4a
$7,199,610
Total Costs
$18,071,910
Notes: PW30 = present worth 30-year costs
A 3.0 percent discount rate, as per the United States Office of Management and Budget (OMB) Circular A-94 Appendix
C (2012), was used for real discount rates over a 30-year period.
2.12.8 Summary of the Rationale for the Selected Remedies
EPA selected the remedies for the FOSET #2 Group 2 Action Sites based on the Air Force FSs (CH2MHill,
2011 and 2012) and FS Addendums (EPA, 2016b and 2016c), as well as the 2017 data gap investigation
results (TetraTech, 2017). The principal factors considered in choosing the selected remedies for each site
are summarized in the following sections. Site-specific rationale for remedy selection can be found in
Attachment D.
Alternative VOC2 - Institutional Controls to Prohibit Residential Use (Restricted Land Use) was
selected for eight of the FOSET #2 Group 2 Action Sites - CS T-059, PRL P-003, PRL S-037, SA 037, SA
048, SA 068, SA 077, and SA 098.
For these sites, Alternative VOC2 was chosen because ICs for VOCs in SSG are cost-effective and
technically feasible solutions for sites with low-level or limited contamination. Alternative VOC is also
protective for sites where SSG characterization remains uncertain. ICs limit exposure to contaminants
remaining in place above unrestricted levels in SSG by prohibiting use by residents and other sensitive
receptors (e.g., hospitals, day care centers, and public or private schools for persons under 18 years of age).
ICs are easily implementable and effective in the short- and long-term as long as they are monitored and
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enforced. Because the future land use is expected to be industrial or industrial/commercial, ICs selected as
the remedial alternative to prohibit residential use are protective of human health and the environment and
comply with ARARs.
Alternative VOC2 - Institutional Controls to Prohibit Residential Use (Restricted Land Use) and
Alternative Non-VOC2 - Institutional Controls to Restrict Land Use, Engineering Controls, and
Monitoring (Restricted Land Use) were selected for ten of the FOSET #2 Group 2 Action Sites - CS P-
005, SA 038, SA 040, SA 043, SA 047, SA 059, SA 071, SA 073, SA 086, and SA 094.
For these sites, Alternative VOC2 was chosen because ICs for VOCs in SSG are cost-effective solutions
for sites with low-level or limited contamination. Alternative VOC is also protective for sites where SSG
characterization remains uncertain. ICs limit exposure to contaminants remaining in place above
unrestricted use levels in SSG by prohibiting use by residents and other sensitive receptors (e.g., hospitals,
day care centers, and public or private schools for persons under 18 years of age). ICs are easily
implementable and effective in the short- and long-term, as long as they are monitored and enforced.
Because the future land use is expected to be industrial or industrial/commercial, ICs selected as the
remedial alternative to prohibit residential use are protective of human health and the environment and
comply with ARARs. Alternative Non-VOC2 was chosen either because the soil risks are greater than the
risk management range for restricted use or because COC concentrations in soil exceed cleanup levels for
protection of surface water quality. ICs and ECs are protective of site workers, are protective of surface
water quality, and are easily implementable and effective in the short- and long-term. ECs limit impacts to
water quality. Both ICs and ECs are easily implementable and effective in the short- and long-term, as long
as they are monitored and enforced. Non-VOC2 may be preferable to Non-VOC4a because the use of this
area is industrial and because there is uncertainty at some sites regarding the extent of contaminants (i.e.,
beneath buildings, etc.), and thus the cost to achieve industrial use cleanup levels under Alternative Non-
VOC4a is more uncertain.
Alternative VOC2 - Institutional Controls to Prohibit Residential Use (Restricted Land Use) and
Alternative Non-VOC4a - Excavation/Disposal (Restricted Land Use) was selected for one of the
FOSET #2 Group 2 Action Sites - PRL T-015.
For this site, Alternative VOC2 was chosen because ICs for VOCs in SSG are cost-effective solutions for
sites with low-level or limited contamination. Alternative VOC is also protective for sites where SSG
characterization remains uncertain. ICs limit exposure to contaminants remaining in place above
unrestricted use levels in SSG by prohibiting use by residents and other sensitive receptors (e.g., hospitals,
day care centers, and public or private schools for persons under 18 years of age). ICs are easily
implementable and effective in the short- and long-term, as long as they are monitored and enforced.
Because the future land use is expected to be industrial or industrial/commercial, ICs selected as the
remedial alternative to prohibit residential use are protective of human health and the environment and
comply with ARARs. Alternative Non-VOC4a was chosen either because COC concentrations in soil
exceed cleanup levels for both unrestricted and industrial use. Excavation will remove soil contaminants
to eliminate risk to workers, is protective of water quality, and is easily implementable and effective in the
short- and long-term. ECs limit impacts to surface water quality. Both ICs and ECs are easily
implementable and effective in the short- and long-term, as long as they are monitored and enforced. Non-
VOC4a is preferable to Non-VOC4b because the use of this area is industrial and because there is
uncertainty at some sites regarding the extent of contaminants (i.e., beneath buildings, etc.), and thus the
cost to achieve unrestricted use cleanup levels under Alternative Non-VOC4b is more uncertain.
Alternative VOC3 - Institutional Controls to Mitigate Shallow Soil Gas Contamination (Restricted
Land Use) were selected for ten of the FOSET #2 Group 2 Action Sites - CS S-021, CS S-027, CS T-037,
PRL L-005 (F2), PRL P-004, SA 044, SA 053, SA 058, SA 067, and SA 101.
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For these sites, Alternative VOC3 was chosen because the SSG risks are greater than or within the risk
management range for restricted use. Alternative VOC3 is protective because it ensures that the vapor
inhalation pathway will not be complete for site users, as it requires mitigation for potential vapor intrusion
from SSG for new construction. The landowner may choose to mitigate SSG through the use of ECs
including vapor barriers, gas collection, and/or ventilation. Alternatively, prior to new construction, the
landowner or developer is required to demonstrate there is not an unacceptable risk under the restricted use
scenario for a vapor intrusion pathway through sampling and analysis. ICs limit exposure to contaminants
remaining in place above unrestricted levels in SSG by prohibiting use by residents and other sensitive
receptors (e.g., hospitals, day care centers, and public or private schools for persons under 18 years of age),
while ECs limit exposure for workers. Both ICs and ECs are easily implementable and effective in the
short- and long-term, as long as they are monitored and enforced. Because the future land use is expected
to be industrial or industrial/commercial, maintenance of the existing ICs as well as the implementation of
ECs, as necessary, are protective of human health and the environment and comply with ARARs. SSG IC
compliance levels for VOCs, above which ECs for mitigation are necessary, are presented in Table 2-5;
they are protective of human health and the environment and comply with ARARs. The 100-foot buffer
zone can be reduced or eliminated if there is SSG data that demonstrates there is no SSG contamination
above the IC compliance levels in an area.
Alternative VOC3 - Institutional Controls to Mitigate Shallow Soil Gas Contamination (Restricted
Land Use) and Alternative Non-VOC2 - Institutional Controls to Restrict Land Use, Engineering
Controls, and Monitoring (Restricted Land Use) were selected for nine of the FOSET #2 Group 2 Action
Sites - AOC 325, CS P-006, PRL L-001 (F2), PRL L-002, PRL L-003 (F2), PRL T-031, PRL T-033, SA
079, and SA 102.
For these sites, Alternative VOC3 was chosen because the SSG risks are greater than or within the risk
management range for restricted use. Alternative VOC3 is protective because it ensures that the vapor
inhalation pathway will not be complete for site users, as it requires mitigation for potential vapor intrusion
from SSG for new construction. The landowner may choose to mitigate SSG through the use of ECs
including vapor barriers, gas collection, and/or ventilation. Alternatively, prior to new construction, the
landowner or developer is required to demonstrate there is not an unacceptable risk under the restricted use
scenario for the vapor intrusion pathway through sampling and analysis. ICs limit exposure to contaminants
remaining in place above unrestricted levels in SSG by prohibiting use by residents and other sensitive
receptors (e.g., hospitals, day care centers, and public or private schools for persons under 18 years of age),
while ECs limit exposure for workers. Both ICs and ECs are easily implementable and effective in the
short- and long-term, as long as they are monitored and enforced. Because the future land use is expected
to be industrial or industrial/commercial, maintenance of the existing ICs as well as the implementation of
ECs, as necessary, are protective of human health and the environment and comply with ARARs. SSG IC
compliance levels for VOCs, above which ECs for mitigation are necessary, are presented in Table 2-5;
they are protective of human health and the environment and comply with ARARs. The 100-foot buffer
zone associated with VOC3 can be reduced or eliminated if there is SSG data that demonstrates there is no
SSG contamination above the IC compliance levels in an area.
Alternative Non-VOC2 was chosen either because the soil risks are greater than the risk management range
for restricted use or because COC concentrations in soil exceed cleanup levels for protection of surface
water quality. ICs and ECs are protective of site workers, are protective of surface water quality, and are
easily implementable and effective in the short- and long-term. ECs limit impacts to water quality. Both
ICs and ECs are easily implementable and effective in the short- and long-term, as long as they are
monitored and enforced. Non-VOC2 is preferable to Non-VOC4a because the use of this area is industrial
and because there is uncertainty at some sites regarding the extent of contaminants (i.e., beneath buildings,
etc.), and thus the cost to achieve industrial use cleanup levels under Alternative Non-VOC4a is more
uncertain.
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Alternative VOC3 - Institutional Controls to Mitigate Shallow Soil Gas Contamination (Restricted
Land Use) and Alternative Non-VOC4a - Excavation/Disposal (Restricted Land Use) were selected
for four of the FOSET #2 Group 2 Action Sites -PRL L-004, PRL S-022 & SA 069, and SA 081.
For these sites, Alternative VOC3 was chosen because the SSG risks are greater than or within the risk
management range for restricted use. Alternative VOC3 is protective because it ensures that the vapor
inhalation pathway will not be complete for site users, as it requires mitigation for potential vapor intrusion
from SSG for new construction. The landowner may choose to mitigate SSG through the use of ECs
including vapor barriers, gas collection, and/or ventilation. Alternatively, prior to new construction, the
landowner or developer is required to demonstrate there is not an unacceptable risk under the restricted use
scenario for a vapor intrusion pathway through sampling and analysis. ICs limit exposure to contaminants
remaining in place above unrestricted levels in SSG by prohibiting use by residents and other sensitive
receptors (e.g., hospitals, day care centers, and public or private schools for persons under 18 years of age),
while ECs limit exposure for workers. Both ICs and ECs are easily implementable and effective in the
short- and long-term, as long as they are monitored and enforced. Because the future land use is expected
to be industrial or industrial/commercial, maintenance of the existing ICs as well as the implementation of
ECs, as necessary, are protective of human health and the environment and comply with ARARs. SSG IC
compliance levels for VOCs, above which ECs for mitigation are necessary, are presented in Table 2-5;
they are protective of human health and the environment and comply with ARARs. The 100-foot buffer
zone associated with VOC3 can be reduced or eliminated if there is SSG data that demonstrates there is no
SSG contamination above the IC compliance levels in an area.
Alternative Non-VOC4a was chosen either because the soil risks are greater than the risk management
range for restricted use or because COC concentrations in soil exceed cleanup levels for protection of
groundwater and/or surface water quality. Excavation will remove soil contaminants to eliminate risk to
workers, is protective of water quality, and is easily implementable and effective in the short- and long-
term. ECs limit impacts to surface water quality. Both ICs and ECs are easily implementable and effective
in the short- and long-term, as long as they are monitored and enforced. Non-VOC4a is preferable to Non-
VOC4b because the use of this area is industrial and because there is uncertainty at some sites regarding
the extent of contaminants (i.e., beneath buildings, etc.), and thus the cost to achieve unrestricted use
cleanup levels under Alternative Non-VOC4b is more uncertain.
Based on estimates of the vertical and lateral extent of contamination at the sites requiring excavation,
approximately 50,830 cubic yards will be excavated and disposed from all of the FOSET #2 Group 2 Action
Sites using Alternative Non-VOC4a. Because the future land use is expected to be industrial or
industrial/commercial, maintenance of the existing ICs as well as the implementation of the excavation and
disposal remedy are protective of human health and the environment and comply with ARARs.
Alternative Non-VOC2 - Institutional Controls to Restrict Land Use, Engineering Controls, and
Monitoring (Restricted Land Use) was selected for three of the FOSET #2 Group 2 Action Sites - PRL
P-001, PRL T-019, and SA 078.
Alternative Non-VOC2 was chosen either because the soil risks are greater than the risk management range
for restricted use or because COC concentrations in soil exceed cleanup levels for protection of surface
water quality. ICs and ECs are protective of site workers, are protective of surface water quality, and are
easily implementable and effective in the short- and long-term. ECs limit impacts to surface water quality.
Both ICs and ECs are easily implementable and effective in the short- and long-term, as long as they are
monitored and enforced. Non-VOC2 is preferable to Non-VOC4a because the use of this area is industrial
and because there is uncertainty at some sites regarding the extent of contaminants (i.e., beneath buildings,
etc.), and thus the cost to achieve industrial use cleanup levels under Alternative Non-VOC4a is more
uncertain.
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2.12.9 Expected Outcomes
Following implementation of Alternatives VOC2 (ICs to Prohibit Residential Use) and VOC3 (ICs to
Restrict Land Use and ECs to Mitigate SSG Contamination), the expected outcome would be a restriction
on land use to industrial purposes only. SSG IC compliance levels apply to VOCs at sites where Alternative
VOC3 is selected as part of the remedy. SSG IC compliance levels are used as the basis for the extent of
IC compliance boundaries for SSG and are presented in Table 2-5. Under Alternative VOC3, mitigation
for vapor intrusion or sampling to show acceptable risk for any future construction or significant remodeling
of existing buildings would be required for any areas within the IC compliance boundaries, as well as the
100 foot buffer zone. The 100-foot buffer zone can be reduced or eliminated if there is SSG data that
demonstrates there is no SSG contamination above the IC compliance levels in an area. Because anticipated
future land use at these sites is industrial in nature, the restrictions and limitations are consistent with the
intended reuse. The property would be available for industrial reuse immediately upon implementation of
the remedies selected in this ROD.
Following implementation of Alternative Non-VOC2 (ICs, ECs, and Monitoring [Restricted Use]), the
expected outcome would be a restriction on land use to industrial purposes only. Potential threats to surface
water would also be mitigated by ECs. If the average residual concentrations in the 0- to 1-foot-bgs interval
exceed cleanup levels for protection of surface water, then a water quality assessment, ECs, and/or
monitoring would be required to address potential impacts to surface water. If monitoring is required, it
would be conducted over a period of at least three years. Additional limitations on intrusive activities
without regulatory agency approval and/or ECs to address potential impacts to surface water would be
required at some sites (Table 2-8). Because anticipated future land use at these sites is industrial in nature,
the restrictions and limitations are consistent with the intended reuse. The property would be available for
industrial reuse immediately upon implementation of the remedies selected in this ROD.
Following implementation of Alternative Non-VOC4a (Excavation and Disposal [Restricted Land Use]),
all wastes exceeding industrial use cleanup levels (see Table 2-3) will have been removed, and the resulting
risks would be acceptable for industrial reuse of the property. Potential threats to groundwater and surface
water would also be mitigated. If, based on the sampling for specific sites as identified in Attachment D
during the Remedial Design phase, the average residual concentrations in the 0- to 1-foot-bgs interval
exceed cleanup levels for protection of surface water, then a water quality assessment, ECs, additional
excavation, and/or monitoring would be required to address potential impacts to surface water. If
monitoring is required, it would be conducted over a period of at least three years. The expected outcome
would be a restriction on land use to industrial purposes only. Additional limitations on intrusive activities
without regulatory agency approval and/or ECs to address potential impacts to surface water would be
required at some sites (Table 2-8). Because anticipated future land use at these sites is industrial in nature,
the restrictions and limitations are consistent with the intended reuse. Industrial or commercial use of the
property could be achieved within 6 months to a year.
The first RAO (protection of human health, prevent inhalation, ingestion, direct contact, and external
exposure to shallow soil gas and soil within the upper 15 feet bgs posing excess cancer risk greater than the
CERCLA risk range [1 x 10-6 to 1 x 10-4] or an HI greater than 1) will be achieved if the concentration of
each contaminant is less than or equal to cleanup levels presented in Section 2.8.3 for current and anticipated
future land use. Cleanup levels are included for both unrestricted and industrial use and are generally based
on a risk of 1 x 10-6 or an HQ of 1. In cases where concentrations still exceed the cleanup levels, ICs and
ECs will be implemented, monitored, enforced, maintained, and reported on in order to prevent exposure
and protect human health.
For non-VOCs, the second RAO (protect surface water and groundwater quality and beneficial uses from
contaminants in soil and sediment) will achieve protection of groundwater if the concentration of each
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
contaminant in soil is less than its respective cleanup level for protection of groundwater as presented in
Section 2.8.3. For protection of surface water, the RAO is achieved if the concentration of each contaminant
in soil is less than its respective cleanup levels for protection of surface water or if ECs eliminate
contaminant migration. For VOCs, impacts to surface water are not expected because of the inherent
volatility of VOCs. Impacts to groundwater from VOCs are not addressed in this ROD. Impacts to
groundwater from VOCs below 15 feet bgs at several of the FOSET #2 Group 2 Action Sites are being
addressed as part of the ongoing SVE program under the VOC Groundwater ROD (AFRPA, 2007).
For the third RAO (protect ecological receptors), land use at the FOSET #2 Group 2 Action Sites is
currently, and is expected to remain into the foreseeable future, primarily industrial or
industrial/commercial. There are limited areas with grassland within and wetland/vernal pool habitats
adjacent to some of the FOSET #2 Group 2 Action Sites. As described in Section 2.7.2, all of the FOSET
#2 Group 2 Action Sites have been determined not to pose significant risks, at this time, to ecological
receptors either onsite or in downgradient habitats.
2.13 STATUTORY DETERMINATIONS
Under CERCLA §121 and the NCP, the lead agency must select remedies that are protective of human
health and the environment, comply with ARARs (unless a statutory waiver is justified), are cost-effective,
and use permanent solutions and alternative treatment technologies or resource recovery technologies to
the maximum extent practicable. In addition, CERCLA includes a preference for remedies that employ
treatment that permanently and significantly reduces the volume, toxicity, and mobility of hazardous wastes
as a principal element and a bias against disposal of untreated wastes. The selected site remedies do not
satisfy the statutory preference for treatment as a principal element of the remedies because costs to achieve
the same risk reduction using treatment are significantly higher. The response actions selected in this ROD
are necessary to protect public health or the environment from actual or threatened releases of hazardous
substances into the environment and from actual or threatened releases of pollutants.
The following sections provide a brief description of how (or if) the selected remedies satisfy the statutory
requirements of CERCLA §121 and the Five-Year Review requirements.
2.13.1 Protection of Human Health and the Environment
The selected remedies will protect human health and the environment through a series of remedies,
including excavating contaminated surface and subsurface soils within the upper 15 feet bgs, ICs and/or
ECs selected to prevent human exposure to contaminants that exceed the health-based clean up levels or
removal of sediments and subsurface soils that exceed cleanup levels for the protection of water quality.
Where excavation has been selected, soil will be excavated and transported for disposal at an appropriate
facility, further limiting human and environmental exposure. ICs implemented as part of the selected
remedies will also protect human health and the environment by restricting site uses that would allow
exposure to any residual contamination. The selected remedies will not pose unacceptable short-term risks
or result in cross-media impacts.
Under Alternatives VOC2 and VOC3, ICs would provide protection of human health and the environment
by limiting exposure to contaminants in SSG. Access restrictions and land use restrictions would be
designed to prevent exposure.
Under Alternative Non-VOC2, ICs and ECs would provide protection of human health and the environment
by limiting exposure to contaminants in soil. Access restrictions and land use restrictions would be
designed to prevent exposure and ECs would be used to minimize the potential for migration of
contaminants to surface water.
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Under Alternative Non-VOC4a, excavation and disposal of contaminated soil/sediment within the upper
15 feet bgs at concentrations greater than industrial use cleanup levels or surface water and/or groundwater
cleanup levels would provide protection of human health and the environment by physically removing the
contaminants from the site, eliminating direct exposure, and minimizing the potential for migration of
contaminants to groundwater and surface water. Under Alternative Non-VOC4a, contamination would
remain at the sites at levels acceptable for industrial use. Therefore, ICs would be implemented to protect
human health and, as appropriate, ECs and/or monitoring would be implemented to protect surface water.
2.13.2 Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)
Section 121(d) of CERCLA states that remedial actions on CERCLA sites must attain (or justify the waiver
of) any federal or more stringent state environmental standards, requirements, criteria, or limitations that
are determined to be ARARs. Applicable requirements are those cleanup standards, criteria, or limitations
promulgated under federal or state law that specifically extend to the situation at a CERCLA site. Relevant
and appropriate requirements are federal or state cleanup standards, requirements, criteria, or limitations
that, while not "applicable" to a hazardous substance, action, location, or other circumstance at a CERCLA
site, address problems or situations sufficiently similar to those found at the site. The selected remedies
will meet all federal or state standards, requirements, criteria or limitations that have been determined to be
ARARs for the FOSET #2 Group 2 Action Sites contamination. These ARARS are presented in Attachment
A.
California Regional Water Quality Control Board, Central Valley Region Position Regarding
Resolution 92-49 as an ARAR for the FOSET #2 Group 2 Action Sites ROD:
The Central Valley Water Board has identified State Water Resources Control Board Resolution No. 92-
49 as an ARAR for several of the remedial actions being selected for certain sites in this ROD. The Water
Board asserts that Resolution No. 92-49 is an applicable requirement for remedial actions that may impact
waters of the state pursuant to Water Code Section 13050, "Waters of the state" means any surface water
or ground water, including saline waters, within the boundaries of the state.
EPA disagrees with the Central Valley Water Board about the applicability of Resolution No. 92-49 for the
remedial actions being selected in this ROD. However, there is no substantive dispute as to the selected
remedies and cleanup levels for this cleanup action, and the Central Valley Water Board believes the
selected remedies and cleanup levels set forth in the ROD substantively comply with Resolution No. 92-
49. The Central Valley Water Board reserves any and all rights to assert Resolution No. 92-49 as an ARAR
in any future ROD and without prejudice to its position, the Central Valley Water Board agrees to concur
with this ROD.
EPA's Position Regarding Resolution 92-49 as an ARAR for the FOSET #2 Group 2 Action Sites
ROD:
In general, EPA does not believe Resolution 92-49 is a relevant and appropriate requirement when the
remedial action only addresses soil. This has been EPA's legal opinion over many years and its
longstanding practice in identifying ARARs for soil cleanups at both private and Federal Facility sites.
EPA agrees there may be instances where a soils remedial action could directly impact groundwater and in
such instances, certain substantive provisions of Resolution 92-49 may be an ARAR.
The FOSET #2 Group 2 Action Sites ROD addresses only soil, with MBP undertaking the implementation
of the ROD under the 2013 AoC. The Air Force has retained responsibility for "groundwater and existing
contamination or other environmental conditions greater than 15 feet below ground surface" at the FOSET
#2 Group 2 Action Sites (designated as "retained conditions" in the Administrative Order on Consent).
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Although there are a number of sites addressed in this ROD that have groundwater contamination
underneath, this contaminated groundwater is being addressed in the VOC Groundwater ROD, which was
signed in 2007, and the Non-VOC ROD Amendment signed in 2009. If the soils remedial action required
by the FOSET #2 Group 2 Action Sites ROD fails to address the impacts to the groundwater, the Air Force
VOC Groundwater ROD will address such impacts or, if necessary, the Air Force VOC Groundwater ROD
can be amended to address such impacts. In addition, EPA has provided language in the Declaration that
describes the mechanisms to address soils contamination near the 15-foot bgs horizon.
2.13.3 Use of Permanent Solutions and Alternative Treatment Technologies to the
Maximum Extent Practicable
EPA has selected remedies for the FOSET #2 Group 2 Action Sites that are protective of human health and
the environment, comply with federal and state ARARs for the remedial actions, and are cost-effective.
The selected remedies will remove some of the source materials that contribute substantially to the risks.
The selected remedies do not use alternative treatment technologies because they are not appropriate for
site circumstances. The selected remedies satisfy the criteria for long-term effectiveness by removing TPHs
and metals from the site. Off-site disposal of contaminated soil effectively reduces the mobility of
chemicals and potential for direct contact.
2.13.4 Preference for Treatment as a Principal Element
The selected site remedies do not satisfy the statutory preference for treatment as a principal element of the
remedies because costs to achieve the same risk reduction using treatment are significantly higher. The
hazardous substances present at the FOSET #2 Group 2 Action Sites are not considered principal threat
wastes and, therefore, do not trigger the NCP expectation for treatment of principal threat wastes. For
example, there are no liquid, mobile, or highly toxic source materials present at the FOSET #2 Group 2
Action Sites.
For VOCs in shallow soil gas, treatment is not practicable to address the indoor air pathway. SVE was
evaluated in the FSs as a treatment option (Alternative VOC4); however, given the relatively low and
distributed concentrations of SSG, SVE is not technically feasible and was therefore screened out. There
are no liquid, highly mobile, or highly toxic source materials that would require treatment. Treatment of
excavated soil prior to disposal is not expected to be necessary; however, need for treatment cannot be
determined until excavation occurs and the removed soil is characterized for disposal.
2.13.5 Requirements for Five-Year Reviews
Because these remedies result in hazardous substances, pollutants, or contaminants remaining on the site
above levels that allow for unlimited use and unrestricted exposure, a statutory Five-Year review will be
conducted for the FOSET #2 Group 2 Action Sites.
The Air Force will consolidate the protectiveness determinations for the remedies at the FOSET #2 Group
2 Action Sites in subsequent Five-Year Reviews. The next Five-Year Review will occur in 2019 in
coordination with Five-Year Reviews being conducted by the Air Force and every 5 years thereafter to
ensure that the remedies are, or will be, protective of human health and the environment.
2.13.6 Cost Effectiveness
In EPA's judgment, the selected remedies for the FOSET #2 Group 2 Action Sites are cost-effective.
According to the NCP, a remedy is cost-effective if its costs are proportional to its overall effectiveness.
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The overall effectiveness of the selected remedies was demonstrated in the comparative analysis of the
alternatives. The selected remedies satisfy the threshold criteria (overall protectiveness and compliance
with ARARs), while scoring high with respect to long-term effectiveness and short-term effectiveness.
The overall effectiveness of the alternatives was then evaluated with respect to cost. Alternative VOC2
includes limited additional costs to modify the land use restrictions in the federal deed and SLUC and is,
therefore, a cost-effective remedy. Alternative VOC3 incurs limited costs, other than for maintenance,
inspection, reporting and possible enforcement of the ICs, and for any potential future sampling or ECs
necessary to address risks of vapor intrusion. Costs for Alternatives Non-VOC 2 and Non-VOC4a are
required to protect public health and the environment. Therefore, these remedies are also considered cost-
effective for these sites relative to the necessary remedial action.
2.13.7 State Acceptance
The DTSC and Central Valley Water Board have been an integral part of the CERCLA process for the
FOSET #2 Group 2 Action Sites including the 2017 Proposed Plan and drafting this ROD. They concur on
the selected remedies for the FOSET #2 Group 2 Action Sites.
2.13.8 Community Acceptance
EPA issued a final Proposed Plan (EPA, 2017a) for the FOSET #2 Group 2 Action Sites on April 10, 2017
for public comment. The public comment period on the Proposed Plan was held from April 10 to May 10,
2017 and a public meeting was held on April 20, 2017. Responses to all comments received are presented
in Section 3.0.
2.14 DOCUMENTATION OF SIGNIFICANT CHANGES
The following changes have occurred subsequent to the Proposed Plan that was released for public comment
in April 2017.
• The Proposed Plan listed Alternatives VOC2 and Non-VOC2 as the selected remedies for PRL T-
015. However, there were concerns regarding potential impacts to industrial users and to surface
water due to an elevated PCB concentration at sample location PL2SB004 (Aroclor-1260 was
detected at a concentration of 6.65 mg/kg in a sample collected from 0-0.5 ft bgs, which exceeds
the residential cleanup level of 0.063 mg/kg for residential and the industrial cleanup level of 0.17
mg/kg). Non-VOC4a will remove the elevated PCBs at sample location PL2SB004. Therefore,
Alternatives VOC2 and Non-VOC4a were selected for PRL T-015 in this ROD.
• The Proposed Plan listed Alternatives VOC2 and Non-VOC2 as the selected remedies for PRL T-
031. However, there were concerns regarding potential impacts to industrial users due to elevated
VOC concentrations in SSG. VOC2 provides protection under the unrestricted use scenario, but
would not protect industrial users. VOC3 includes the addition of ECs, which will control
migration of soil gas into indoor air and provide protection of industrial users. Therefore,
Alternatives VOC3 and Non-VOC2 were selected for PRL T-031 in this ROD.
• The Proposed Plan listed Alternative VOC2 as the selected remedy for PRL P-004, SA 044, SA
053, and SA 101. However, elevated concentrations of TCE were detected at SA 044 during the
2017 interim SSG data gap investigation and there were concerns regarding potential impacts to
industrial users. Similarly, elevated concentrations of chloroform were detected at PRL P-004 and
SA 101 during the 2017 interim SSG data gap investigation and there were concerns regarding
potential impacts to industrial users. At SA 053, TCE was detected at approximately ten times
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above the IC compliance level in a sample collected in 2005, so there were concerns regarding
potential impacts to industrial users. VOC2 provides protection under the unrestricted use scenario,
but would not protect industrial users. VOC3 includes the addition of ECs, which will control
migration of soil gas into indoor air and provide protection of industrial users. Therefore
Alternative VOC3 was selected for PRL P-004, SA 044, SA 053, and SA 101 in this ROD.
• The Proposed Plan listed Alternative VOC3 as the selected remedy for SA 079. However, cadmium
was under-represented in the risk assessment. A maximum value of 2.0 mg/kg was considered in
the risk assessment, but the maximum concentration is 18 mg/kg at a depth of 10.25 feet bgs.
Cadmium concentrations exceed the cleanup level and add to the HI value (by approximately 3
resulting in a soil HI of 6). The HI is greater than 1, so a Non-VOC remedy was selected to protect
human health. Therefore Alternatives VOC3 and Non-VOC2 were selected for SA 079 in this
ROD.
3.0 PART 3: RESPONSIVENESS SUMMARY
EPA received four verbal comment during the public meeting, however only one comment was related to
the remedies described in the proposed plan. The comment and EPA's response are provided below. There
were no written comments received during the public comment period.
3.1 STAKEHOLDER COMMENTS AND LEAD AGENCY RESPONSES
Tracey Payne, Community Member: Well, so far from what I've read of it, I agree with what I have
read. I have not read the entire plan, but I just - obviously, it's very detailed, but just some of the
descriptions that I've read, I agree with your plan. Just how soon will it get done ? I mean, when will it be
implemented?
EPA Response: The remedies with ICs/ECs only will be implemented within one to two years of the
signature of the ROD, while remedies that include excavation and disposal will be implemented within two
to three years.
Frank Miller, Community Member: But all these programs you've talked about tonight, there is no
imminent threat to health and/or safety here. This is nothing more than a lot of make-work. You mentioned
low-level - low-level contaminants, that have no effect on people 's health and safety. This is nothing more
than make-work and environmental welfare. And moving forward, next year, all these plans that you have
are going to be swept away.
EPA Response: Although contaminants are present at low levels, the risks are cumulative. The presence
of multiple contaminants, even at low levels, result in risk values at exceed the risk management range
(greater than 1 x 10"4) or in HI values greater than 1, which are not insignificant risks.
Dabney Lee, Community Member: I just feel that it would be important to stick with the guidelines like
he has mentioned, five years on cleaning up the soil. And I think that they should not take any longer. And
then he mentioned about 20 years to clean up the water. And I don't think that should take longer than the
20 years. And so, much planning has to be done so that all of these steps are divided, not to extent the
employment any longer. And that's all I have to say.
EPA Response: It should be noted that groundwater cleanup is addressed under separate RODs, (the VOC
Groundwater ROD and the Non-VOC ROD Amendment). This ROD for the FOSET #2 Group 2 Action
Sites does not address groundwater or soil deeper than 15 feet bgs.
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Robert Blanchard, Community Member, Retired U.S. Air Force: I have to say that, in my opinion, and
I sat on the RAB for 20 years, and I've seen from the very beginning of it, that a lot ofpeople made a lot of
money or got a lot of credit towards retirement or whatever. Because initially, there's - something had to
be done, small thing.
But the first thing is, we gave that to Sacramento County, and we've been paying for it ever since. And
anything that they can generate to put a little more money and give it to the Air Force, it seems like they
take the opportunity. I '11 tell you, as - I had over 4,000 hours in the Air Force, flying, and I 'm sure that
that money could have been used for aircraft, and today they cost much more than they did then. We 're
going to need that money desperately.
Comparatively, it's like going in the desert with a can of shrimp or something in your pocket. I mean, my
God. We have wasted and squandered on these. I think the Russians had a better idea: encapsulate the
damn thing. Each puddle they had out there, fill it full of cement and leave it there
Right now, what have they got out there? The fire department is practicing out there, and they 're making
their own contamination. But that land was fine for that. We 're not growing tomatoes out there.
1 think that really it - from the very concept was wrong
We wasted millions. And right now we 're farming out the maintenance from this. So that right - going
right back to the very roots of it, it was a waste to give this to Sacramento County.
EPA Response: Sacramento County has not provided the funds for remediation of the FOSET #2 Group
2 Action Sites under this ROD. The funds for remediation of the FOSET #2 Group 2 Action Sites under
this ROD have been provided by the Air Force and transferred to Sacramento County.
In addition, while it is understood that no one is currently living or growing food on the FOSET #2 Group
2 Action Sites, ICs and ECs are needed to ensure these types of site uses are prevented in the future. Without
the implementation of ICs and ECs, there would be no restrictions regarding the future site use.
3.2 TECHNICAL AND LEGAL ISSUES
There are no significant technical changes to the selected remedy. There are no additional significant
technical or legal issues.
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4.0 REFERENCES
Air Force Real Property Agency (AFRPA). 2003. Record of Decision For No Action For Soil at Six (6)
Sites: PRL B-004, SA 064, SA 039, SA 050, PRL 035, and SA 017. Former McClellan Air Force
Base, California. Final. January.
AFRPA. 2004. LRA Initial Parcel Record of Decision #1 (7 Sites) For Soil at PRL S-014, PRL S-033,
PRL S-040, SA 003, SA 035, SA 041, SA 091. Former McClellan Air Force Base, California.
Final. June.
AFRPA. 2007. Basewide VOC Groundwater Record of Decision. Former McClellan Air Force Base,
California. Final. August.
AFRPA. 2008. Local Reuse Authority Initial Parcel Record of Decision #2. Former McClellan Air Force
Base, California. October.
AFRPA. 2009. Non-VOC Amendment to the Basewide VOC Groundwater Record of Decision. Former
McClellan Air Force Base, California. Final. September.
AFRPA. 2010. Area of Concern G-l Record of Decision. Former McClellan Air Force Base, California.
Final. January.
AFRPA. 201 la. McClellan Federal Facility Agreement Amendment No. 3. August.
AFRPA. 201 lb. SR401 Skeet Range Record of Decision. Former McClellan Air Force Base, California.
Final. June.
AFRPA. 2012a. Finding of Suitability for Early Transfer (FOSET) #2 Privatized Cleanup Parcels A4b,
A4c, A4d, Bla, Bib, Blc, Bid, B2, B3, C9, C10, C14, C16, E, and L4. May.
AFRPA. 2012b. Environmental Services Cooperative Agreement (ESCA) between the Air Force and
McClellan Business Park. May.
AFRPA. 2012c. Focused Strategic Sites Record of Decision. Former McClellan Air Force Base, California.
Final. April.
AFCEC. 2013. Ecological Sites Record of Decision. Former McClellan Air Force Base, California. Final.
March.
AFCEC. 2014. Follow-on Strategic Sites Record of Decision. Former McClellan Air Force Base,
California. Final. April.
California Environmental Protection Agency (Cal-EPA). 2009. Revised California Human Health
Screening Levels for Lead. Office of Environmental Health Hazard Assessment. September.
California Regional Water Quality Control Board, Central Valley Region (Central Valley Water Board).
1989. Designated Level Methodology.
CH2MHill. 2011. Small Volume Sites Remedial Investigation Characterization Summaries Addenda and
Feasibility Study, Former McClellan Air Force Base. Final. May.
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CH2MHill. 2012. Follow-on Strategic Sites Remedial Investigation Characterization Summaries Addenda
and Feasibility Study, Former McClellan Air Force Base. Final. June.
County of Sacramento. 2002. McClellan Park Special Planning Area. Ordinance No. SZC-2002-0029.
Department of the Air Force. 1990. The McClellan Air Force Base Interagency Agreement, Amended
Federal Facilities Agreement. May.
ED AW. 2000. McClellan Air Force Base Draft Final Reuse Plan. Prepared for the County of Sacramento.
July.
Parsons. 2005. Basewide Vernal Pool Scoping Level/Tier 1 Ecological Risk Assessment. May.
Tetra Tech, Inc. 2014. Soils Management Manual for Transfer Parcels, Revision 1. Prepared for
McClellan Park, LLC.
Tetra Tech, Inc. 2017. FOSET #2 Data Gap Sampling Data Package. Prepared for McClellan Park, LLC.
URS. 2009. Final PRL T-044 Soil Vapor Extraction Termination or Optimization Process (STOP)
Evaluation. June.
URS. 2017. Quarterly Groundwater and SVE Remediation and Monitoring Report - Fourth Quarter 2016.
March.
United States Department of the Interior Fish and Wildlife Service (USFWS). 2010. Biological Opinion
for the Proposed Sanitary Sewer Replacement Project, Sacramento California. August.
U.S. Environmental Protection Agency (EPA). 1989. Risk Assessment Guidance for Superfund, Volume
1, Human Health Evaluation Manual (Part A). EPA/540/1-89/002. December.
EPA. 1999. A Guide to Preparing Superfund Proposed Plans, Records of Decision, and Other Remedy
Selection Decision Documents. Solid Waste and Emergency Response. EPA 540-R-98-031. July.
EPA. 2007. National Priorities List Narrative for McClellan Air Force Base.
http://www.epa.gov/superfund/sites/npl/nar920.htm. Last updated 28 November 2007.
EPA 2009. Parcel C-6 Record of Decision. Prepared for the former McClellan Air Force Base, California.
Final. May.
EPA 2012. Record of Decision for Initial Parcel #3 Property. Former McClellan Air Force Base.
September.
EPA. 2013. Administrative Order on Consent for RI/FS and RD/RA for Cleanup of Portions of Former
McClellan AFB. Prepared by Region 9. Effective date 20 February.
EPA. 2015. Final Record of Decision for FOSET #2 - Action Sites. Former McClellan Air Force Base
Superfund Sites, McClellan, California. Prepared by Region 9. March.
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EPA. 2016a. Final Record of Decision for FOSET #2 - No Further Action Sites. Former McClellan Air
Force Base Superfund Site, McClellan, California. Prepared by Region 9. July.
EPA. 2016b. Final Feasibility Study Addendum for FOSET #2 Small Volume Sites. Former McClellan
Air Force Base, McClellan, California. Prepared by Region 9. November.
EPA. 2016c. Final Feasibility Study Addendum for FOSET #2 Follow-On Strategic Sites. Former
McClellan Air Force Base, McClellan, California. Prepared by Region 9. November.
EPA. 2017a. Final Superfund Proposed Plan, Finding of Suitability for Early Transfer (FOSET) #2 Group
2 Action Sites. Former McClellan Air Force Base. Prepared by Region 9. March.
EPA. 2017b. Memo to File by Valerie Walker regarding the industrial use cleanup level for
poly chlorinated biphenyls. March 16.
EPA. 2018. Final Community Involvement Plan (CIP) for McClellan Business Park. Prepared by Region
9. March.
United States Office of Management and Budget (OMB). 2012. Circular A-94 Appendix C.
http://www.whitehouse.gov/omb/circulars a094/a94 appx-c
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5.0 GLOSSARY/ACRONYMS
Administrative Record—A collection of all the pertinent documents that support the final decisions for
each site. This is located at the former McClellan Air Force Base and at EPA, Region IX.
Air Force Civil Engineer Center (AFCEC or AFCEC/CIBW) —An Air Force unit responsible for
real property management and environmental compliance and restoration, among other things.
Includes the former Air Force Real Property Agency (AFRPA).
Air Force Real Property Agency (AFRPA)—A former field operating agency activated by the secretary
of the Air Force. The mission was to execute the environmental programs and real and personal
property disposal for major Air Force bases being closed in the U.S. Incorporated into AFCEC in
October 2012.
Applicable or relevant and appropriate requirements (ARARs)— Applicable requirements are those
cleanup standards, standards of control, and other substantive environmental protection requirements,
criteria, or limitations promulgated under Federal or State law that specifically address a hazardous
substance, pollutant, contaminant, remedial action, location, or other circumstance at a CERCLA site.
Relevant and appropriate requirements are those cleanup standards, standards of control, and other
substantive environmental protection requirements, criteria, or limitations promulgated under Federal
or State law that, while not "applicable" to a hazardous substance, pollutant, contaminant, remedial
action, location, or other circumstance at a CERCLA site, address problems or situations sufficiently
similar to those encountered at the CERCLA site that their use is well suited to the particular site.
Area of Concern (AOC)—An area identified for further investigation during the Installation Restoration
Program process.
Cleanup levels—Levels set for the protection of human health, groundwater, or surface water. To protect
human health, the set risk level is usually one in a million—an additional person in a million people
may contract cancer.
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)—
Legislation passed in 1980 and designed to respond to the past disposal of hazardous substances. The
act was extensively amended in 1986 by the Superfund Amendments and Reauthorization Act, which
added many provisions and clarified unclear areas in the original law.
Conceptual Site Model (CSM) —A conceptual site model organizes information about a site. It
describes sites geology, hydrogeology, climate, and how and where contaminants are expected to
move and what impacts such movement may have on human health and the environment.
Confirmed Site (CS)—Site identified during the Installation Restoration Program process to have
contaminants above the screening levels being used at the time.
Contaminant of Concern (COC)—A substance selected for environmental cleanup based on predicted
impacts to groundwater resources and a health risk posed by the contaminant.
Engineered Controls (ECs)—Methods of managing environmental and health risks. Engineered
controls, such as barriers placed between a contaminated area and the rest of a site, can be used to
limit exposure pathways.
Explanation of Significant Difference (ESD) —A document to explain and document significant post-
ROD changes. Significant changes generally involve a change to a component of a remedy that does
not fundamentally alter the overall cleanup approach.
Exposure pathway—Ways that people can be exposed to contaminants. Common pathways include
breathing, ingestion, or absorption through the skin.
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Feasibility Study (FS)—A study of a hazardous waste site that must be completed before a cleanup
remedy can be chosen and implemented. The Feasibility Study identifies and evaluates alternatives
for addressing contamination.
Finding of Suitability for Early Transfer (FOSET) —A document that record that a parcel of real
property at a former military installation is suitable for transfer by deed, but that remedial action to
address environmental contamination may still be required.
Five-year review—Regular check-ups conducted on certain Superfund sites (where either treatment
systems are still operating after 5 years or where waste is left behind) to make sure the site is still
safe. Five-year review reports make recommendations on the continuation, modification, or
elimination of annual reports and institutional control monitoring frequencies. Five-year reviews also
represent an opportunity for the public to voice any concerns.
Groundwater—Underground water that fills pores between particles of soil, sand, and gravel or
openings in rocks to the point of saturation. Where groundwater occurs in significant quantity, it can
be used as a source of drinking water.
Hazard index (HI)—The ratio of contaminant concentration divided by the safe exposure level. If the
hazard index exceeds 1, people are exposed to contaminants that may pose non-cancer health risks.
Non-cancer health risks are contaminant-dependent but may include kidney disease, headaches,
dizziness, and anemia. For more information, go to ToxFAQs at http://www.atsdr.cdc.gov/.
Industrial Use—When land is used for industrial, commercial, office, retail, or other occupational
purposes.
Installation Restoration Program (IRP)—Program designed to identify, investigate, and cleanup
contamination.
Institutional Controls (ICs) —Non-engineered mechanisms such as administrative and/or legal controls
that minimize the potential for human exposure to contamination by limiting land or resource use.
Mitigate—The implementation of engineered controls or actions that prevent or make conditions less
severe or harsh.
National Oil and Hazardous Substances Pollution Contingency Plan (NCP)—The federal regulation
that guides determination of the sites to be cleaned up under the Superfund program. This plan also
provides the organizational structure and procedures for preparing for and responding to discharges of
oil and releases of hazardous substances in accordance with CERCLA and the Clean Water Act.
National Priorities List (NPL)—The U.S. Environmental Protection Agency's published list of the
highest priority hazardous waste sites in the U.S. for investigation and cleanup, which are subject to
the Superfund program.
Non-cancer health risk—Health risks that do not result in cancer and may include kidney disease,
headaches, dizziness, and anemia.
Non-volatile organic compounds (non-VOCs)—A group of compounds that do not readily evaporate at
room temperature. They include metals, pesticides, SVOCs, petroleum hydrocarbons, dioxins/furans
and radionuclides.
Occupational Worker—Includes indoor and outdoor workers who may be exposed to chemicals in soil,
air, and water during the course of a workday.
Operable Unit (OU) —The cleanup of a site can be divided into a number of operable units, depending
on the complexity of the problems associated with a site. Operable units may address geographic
portions of a site, specific site problems, or initial phases of an action, or may consist of any set of
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actions that are concurrent but located in different parts of a site. The determination of an operable
unit may vary over time as a result of change in activity or need. For management purposes,
McClellan is subdivided into 11 operable units. Ten operable units correspond to discrete areas of the
base where specific industrial operations and/or waste management activities took place: A, B, Bl, C,
CI, D, E, F, G, and H. The remaining operable unit is the Groundwater OU, which encompasses the
entire base.
Polychlorinated Biphenyls (PCBs)—A group of man-made compounds that were widely used, mainly
in electrical equipment, but were banned at the end of the 1970s in many countries because of
environmental concerns.
Polycyclic aromatic hydrocarbons (PAHs)—Any of a class of carcinogenic organic molecules that
consist of three or more benzene rings.
Potential Release Location (PRL)—A Site identified during the Installation Restoration Program
process to have potentially released contaminants.
Preferred Alternative—EPA's suggested cleanup method(s) for the contaminated site(s). The preferred
alternative is protective of human health and the environment, complies with applicable or relevant
and appropriate requirements, and is cost-effective.
Preliminary Cleanup Goal (PCG)—A preliminary cleanup value used in the FS to evaluate alternatives
and establish target volumes for excavation. This term is replaced by the term "cleanup level" in the
ROD. The term PCG will appear in the legend of the figures in Attachment D, which were taken
from the FSs documents.
Privatization—The process where the Department of Defense provides cleanup funds to a new property
owner with the goal of speeding up redevelopment. EPA, instead of the military in conjunction with
EPA, will decide how the contamination will be cleaned up.
Proposed Plan—A summary of cleanup alternatives for a contaminated site, including a preferred
alternative and the reasons for its selection. This step is the community's opportunity to review and
comment on all cleanup alternatives under consideration. The responses to the comments are
presented in the Record of Decision. All changes from the Proposed Plan are explained in the Record
of Decision.
Record of Decision (ROD)—A document explaining and legally committing the lead agency to the
cleanup alternative(s) that will be used at a site. The Record of Decision is based on information and
technical analyses generated during the Remedial Investigation, the Feasibility Study, and
consideration of public comments and community concerns.
Record of Decision Amendment (ROD Amendment) —A document to explain and document
fundamental post-ROD changes. Fundamental changes involve an appreciable change or changes in
the scope, performance, and/or cost or may be a number of significant changes that together have the
effect of a fundamental change.
Remedial Investigation (RI)—A hazardous waste site study to examine the nature and extent of site
contamination.
Residential Receptor—A resident (child or adult) who may be exposed to chemicals through soil, air,
and water from indoor and outdoor exposure.
Residential Use—When land is suitable for use as housing or any other purpose.
Responsiveness Summary—The section within the Record of Decision that summarizes comments
received from the public during the public comment period and the responses from the lead agency.
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Restoration Advisory Board (RAB)—A board consisting primarily of members of the public. Board
members have the opportunity to review cleanup reports and provide advice to decision makers on
investigation and cleanup matters. The Restoration Advisory Board is a forum for the exchange of
information between community members, regulatory agencies, and Air Force personnel.
Risk Assessment—A study based on the results of the Remedial Investigation to determine the extent to
which chemical contaminants found at a Superfund site pose a risk to public health and the
environment.
Semi-volatile organic compounds (SVOCs)—A group of chemical compounds that evaporate in air at a
slower rate than VOCs. SVOC is a name for a class of compounds and includes PAHs, PCBs,
pesticides, and dioxins/fiirans.
Shallow soil gas (SSG)—Soil gas in the upper 15 feet of soil.
State Land Use Covenant (SLUC)—A legal document that limits future land use.
Soil gas—The air between soil particles that may be contaminated by contaminants that have vaporized in
the soil.
Soil Vapor Extraction (SVE)—A method of treating soil contaminants by extracting contaminated soil
gas using perforated underground pipes connected to vacuum pumps.
State land use covenant (SLUC) —Imposes appropriate limitations on land use and shall be executed
and recorded when hazardous materials, hazardous wastes or constituents, or hazardous substances
will remain at the property at levels which are not suitable for unrestricted use of the land. DTSC is
responsible for recording and enforcement of SLUCs with assistance from EPA and the Central
Valley Water Board.
Study Area (SA)—A site identified during the Installation Restoration Program process that requires
further study for potential contamination.
Total petroleum hydrocarbons (TPH)—A wide range of liquid hydrocarbons, including gasoline and
diesel fuel.
Unrestricted land use—A designation that risk is reduced to such a low level as to allow anything to be
built, including homes and public or private schools for persons under 18 years of age.
Vapor inhalation pathway—A pathway used in risk analysis where contaminants in the soil volatilize
into soil gas, migrate into buildings, and are inhaled by the occupants.
Volatile organic compound (VOC)—An organic compound containing carbon that evaporates
(volatilizes) readily at room temperature. VOCs are used in the manufacturing of paints,
pharmaceuticals, and refrigerants. VOCs typically are industrial solvents, such as trichloroethene
(TCE). Some VOCs are known carcinogens. For more information, go to ToxFAQs at
http://www.atsdr.cdc.gov/.
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
ATTACHMENT A.
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
The ARARs listed below include provisions that could be triggered by activity associated with the selected remedy, although EPA does not expect or anticipate that a number of these provisions will be triggered. The list does not include
provisions that would be triggered by a failure of the selected remedy. Those ARARs would be addressed in an amendment to the ROD.
Action-Specific ARARs
Source
Requirement/
Citation
ARAR
Determination
Description of Requirement
Comments
Sites
Water Quality Control Plan
(Basin Plan) for the Sacramento
and San Joaquin River Basins
Chapter III, Water Quality
Objectives for Inland
Surface Waters
Applicable
The water quality objectives apply to all surface waters in the
Sacramento and San Joaquin River Basins, including the Delta or as
noted.
Any activity, including, for example, a new
discharge of contaminated soils that may affect
water quality must not result in water quality
exceeding water quality objectives.
All Non-VOC sites
Water Quality Control Plan
(Basin Plan) for the Sacramento
and San Joaquin River Basins
Narrative Toxicity Standard
in the Water Quality
Control Basin
Applicable
Chapter III, Narrative Toxicity Objective, states as a policy that all
waters shall be maintained free of toxic substances that produce
detrimental physiological responses in human, plant, animal or
aquatic life.
The narrative toxicity objective is a federally
required water quality objective for surface waters.
All Non-VOC sites
Clean Water Act -
National Pollutant Discharge
Elimination System (NPDES)
Program
California Toxics
Rule (CTR) 40
Code of Federal
Regulations (CFR) Part 131
Applicable
Water quality standards:
EPA adopted water quality criteria that apply in California, called
the California Toxics Rule (CTR).
The CTR establishes water quality standards that apply to NPDES
discharges when certain conditions are met.
The CTR is an ARAR for the sites that pose a
threat to surface water quality. The CTR
establishes criteria for surface water quality.
All Non-VOC sites
Discharges of Storm Water from
Construction Areas
40 CFR Parts 122, 123, 124,
NPDES, implemented by
California Storm Water
Permit for Construction
Activities, State Water
Resources Control Board
Order 2010-0014-DWQ
Applicable
Regulates pollutants in discharge of storm water associated with
construction activity (clearing, grading, or excavation) involving the
disturbance of 1 acre or more. Requirements to ensure storm water
discharges do not contribute to a violation of surface water quality
standards.
Substantive requirements relating to potential
discharge of pollutants to Waters of the United
States from cleanup and remedial action activities.
Applies to construction areas over 1 acre in size.
Includes measures to minimize and/or eliminate
pollutants in storm water discharges and
monitoring to demonstrate compliance
All sites
Discharges of Storm Water from
Industrial Areas
40 CFR Parts 122, 123, 124,
NPDES, implemented by
California Storm Water
Permit for Industrial
Activities, SWRCB Order
97-03 -DWQ
Applicable
Regulates pollutants in discharge of storm water associated with
hazardous waste treatment, storage, and disposal facilities,
wastewater treatment plants, landfills, land application sites, and
open dumps. Requirements to ensure storm water discharges do not
contribute to a violation of surface water quality standards.
The CERCLA permit exemption applies to all
discharges that are related to response actions and
that are "onsite," as that term is defined in the
NCP. Remedial activities should meet the
substantive requirements of the NPDES Program.
All sites
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Source
Requirement/
C'iliilion
ARAR
Detenu in;ilion
Description of Requirement
Comments
Sites
Porter-Cologne Water Quality
Control Act (California Water
Code Sections
13140-13147, 13172, 13260,
13263, 13269).
Title 23, California Code of
Regulations (CCR), Section
2520, 2521
Applicable
Action taken by public agencies to cleanup unauthorized releases are
exempt from Title 27/ Title 23 except that wastes removed from
immediate place of release and discharged to land must be managed
in accordance with classification (Title 27 CCR, Section 20200/
Title 23 CCR, Sections 2520) and siting requirements of Title 27 or
Title 23 and wastes contained or left in place must comply with Title
27 or Title 23 to the extent feasible. Requires that waste be sent to
the appropriate waste management unit, depending on its
classification.
Applies to discharges of waste to land for
treatment, storage or disposal.
All Sites
Remediation and Monitoring of
Sites
Title 27, CCR, Section
20090(d) Title 23 CCR,
Section 2511(d)
Applicable
Exempts cleanup actions taken at the direction of public agencies
from Title 27 provided the waste is discharged in accordance with
Article 2, Subchapter 2, Chapter 3, Subdivision 1 of Section 20090.
Applies if there is designated waste on site and if
hazardous waste is present. Applies to remediation
and monitoring of sites. Before action, waste must
be classified and disposed of consistent with its
classification.
All Sites
Porter-Cologne Water Quality
Control Act (California Water
Code Sections
13140-13147, 13172, 13260,
13263, 13267, 13304).
Title 27, CCR, Section
20080 (d)
Title 23, CCR, Section
2510(d)
Relevant and
Appropriate
Requires closure of existing waste management units according to
Title 27/Title 23.
Applies to "existing" waste management units (i.e.,
areas where waste was discharged to land on or
before November 27, 1984, but that were not
closed, abandoned, or inactive prior to that date).
All Sites
Porter-Cologne Water Quality
Control Act (California Water
Code Sections
13140-13147, 13172, 13260,
13263, 13269).
Title 27, CCR Section
20200(c), 20210
Applicable
Requires that designated waste be sent to Class I or Class II waste
management units.
Applies to discharges of designated waste
(nonhazardous waste that could cause degradation
of surface or ground waters) to land for treatment,
storage, or disposal.
All Sites
Porter-Cologne Water Quality
Control Act (California Water
Code Sections
13140-13147, 13172, 13260,
13263, 13269).
Title 27, CCR Section
20200(c), 20220
Applicable
Requires that nonhazardous solid waste be sent to an appropriate
waste management unit.
Applies to discharges of nonhazardous solid waste
to land for treatment, storage, or disposal.
All Sites
Porter-Cologne
Water Quality
Control Act
(California Water
Code Sections
13140-13147, 13172, 13260,
13263, 13267, 13269).
Title 27, CCR,
Section 20410
Title 23, CCR,
Section 2550.6
Relevant and
Appropriate*
Requires monitoring for compliance with remedial action objectives
for three years from the date of achieving cleanup levels.
Post remediation sediment trap monitoring shall be
conducted to demonstrate that the source of
contamination has been eliminated and to assure
protection of surface water quality.
All Sites
Porter-Cologne Water Quality
Control Act (California Water
Code Sections
13140-13147, 13172, 13260,
13263, 13267, 13269).
Title 27, CCR Section
20950 (a)(2)(B)
Relevant and
Appropriate*
(2) Performance Standards -The performance standards applicable to
closure of a Unit and, for Units that are not clean-closed, to post-
closure maintenance at the Unit are as follows:
(B) Unit Clean-Closed — for Units that are clean-closed, the goal of
closure is to physically remove all waste and contaminated materials
from the Unit and from its underlying and surrounding environs,
such that the waste in the Unit no longer poses a threat to water
quality. Successful completion of clean-closure eliminates the need
for any post-closure maintenance period and removes the Unit from
being subject to the SWRCB-promulgated requirements of this
subdivision.
Applicable to excavated soil to determine partial or
final closure of waste management units.
All Sites
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Source
Requirement/
Citation
ARAR
Determination
Description of Requirement
Comments
Sites
Land Use Covenant
California Civil Code
Section 1471
Relevant and
Appropriate
Allows an owner to enter into restrictive land use covenants as
"reasonably necessary to protect present or future human health or
safety or the environment as a result of the presence on the land of
hazardous materials..." 1471(a)(3)
This language provides authority for establishing a
durable IC that will be implemented through
incorporation of restrictive covenants that run with
the land.
VOC2, VOC3, and Non-
VOC4a sites
Land Use Covenants
Title 22, CCR Section
67391.1
Relevant and
Appropriate
Requires that a land use covenant imposing appropriate limitations
on land use shall be executed and recorded when hazardous
substances will remain at the property at levels not suitable for
unrestricted use of the land.
EPA specifically identifies subsections (a) and (d)
as relevant and appropriate for this ROD. DTSC's
position is that all of the State regulation is an
ARAR.
VOC2, VOC3, and Non-
VOC4a sites
Hazardous Waste Determination
Title 22, CCR Section
66262.11
Applicable
Defines the methods to be used to determine whether a waste is a
hazardous waste.
All Sites
Criteria for Identifying Hazardous
Waste and Persistent and Bio-
accumulative Toxic Substances
Title 22, CCR Ch. 11,
§ 66261.24
Applicable
Presents criteria for testing and identifying RCRA hazardous wastes,
sets levels for total threshold limit concentrations (TTLC) and
soluble threshold limit concentrations (STLC).
The criteria and TTLC and STLC levels are
applicable for the characterization of excavated
soils or other wastes generated by remedial actions.
Non-VOC4a and Non-
VOC4b sites
Standards Applicable to
Generators of Hazardous Waste
Title 22, CCR Sections
66262.10 and 66262.11
Applicable
Establishes standards for generators of hazardous wastes in
California, including those for hazardous waste determination.
Substantive requirements are applicable to
management of excavated soils or treatment
residuals if they exceed RCRA hazardous waste
thresholds.
Non-VOC4a and Non-
VOC4b sites
Use and Management of
Containers
Title 22, CCR Sections
66264.171, 66264.172,
66264.173, 66264,174,
66264.175(a) and (b),
66264.177, and 66264.178
Applicable
These regulations define the requirements for using and managing
containers, including compatibility between wastes and containers,
storage of containers, inspections for leakage/deterioration,
containment of container transfer/storage areas, incompatible wastes,
and containment system closure.
Applicable to sites where containers will be used
for temporary storage or excavated soil /
remediation units.
Non-VOC4a and Non-
VOC4b sites
Land Disposal Restrictions
Title 22, CCR Section
66268.124, Corrective
Management Rule,
§§ 66264.91; 66262.100,
66264.708; 66270.30; and
66272.1
Applicable
Identifies hazardous wastes that are restricted from land disposal.
If excavated soil or treatment residuals exceed
limits they will be evaluated using TTLC/STLC to
determine if treatment is required prior to off-site
disposal.
Non-VOC4a and Non-
VOC4b sites
Pre-transportation Handling of
Hazardous Waste
Title 22, CCR Sections
66262.30, 66262.31,
66262.32, 66262.33, and
66262.34
Applicable
Defines pre-transport requirements for RCRA or California
hazardous waste, including packaging, labeling, marking,
placarding, and accumulation time limitations.
Applicable to RCRA or California hazardous waste
that may be shipped offsite for disposal.
Non-VOC4a and Non-
VOC4b sites
Control of Air Emissions
Rule 403, Fugitive Dusts
Applicable
Limits visible particulate emissions to the property line.
Would be applicable for soil excavation and
handling
Non-VOC4a and Non-
VOC4b sites
Toxic Substances Control Act
(TSCA)
40 CFR Parts 761.60-
761.79
Relevant and
Appropriate
Regulates PCB-contaminated material.
TSCA provides requirements for sampling,
characterization and cleanup of PCB contaminated
soils, including the management of excavated
material and off-site disposal requirements.
CS P-005
PRLP-001
PRL T-033
The State disagrees with EPA's characterization of these requirements as "relevant and appropriate" as by statute and regulation they apply expressly to the circumstances at the site. The State, however, does not object to the ROD because
the State concurs with the selected remedies, and when the ROD is final the performance standards of these ARARs will become the enforceable requirements for the remedial action.
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
ATTACHMENT B. PAST FOSET #2 GROUP 2 ACTION SITES REMOVAL
ACTIONS
Summary of Underground Storage Tank and Oil and Water Separator Removal Actions
Site
keimnal Descriptions
Stains
AOC 325
One 4,000-gallon diesel UST and one 2,000-
gallon aviation fuel UST, both removed in 1996.
Closure granted in 2016.
CS S-021
One solvent UST removed in 1989.
Closure not yet granted.
CS S-027
One OWS, removal date not specified.
Closure not yet granted.
CS T-037
One 500-gallon solvent UST and attached
"homemade" 130-gallon tank, both removed in
1989.
Closure not yet granted.
CS T-059
One 4,000-gallon fuel UST removed in 1987.
Closure granted in 2000.
PRL P-003
One 150-gallon diesel UST removed in 1990.
Closure not yet granted.
PRL S-022
& SA 069
Two 21,000-gallon fuel oil USTs abandoned in
place in 1991 and 1995, respectively. Two
20,000-gallon diesel USTs removed in 1996 and
replaced with two new 20,000-gallon diesel
tanks. The new tanks were removed in July
2003.
Closure not yet granted.
PRL T-015
Nine 50,000-gallon fuel USTs removed in 1997.
Closure not yet granted.
PRL T-019
Three 12,000-gallon aviation fuel and waste
aviation fuel USTs removed in 1960.
Closure not yet granted.
PRL T-031
Two USTs removed in 1989.
Closure granted in 1999.
SA 038
One 5,000-gallon gasohol UST and one 5,000-
gallon leaded gasoline UST replaced in 1980
with one 5,000-gallon diesel UST and one
10,000-gallon unleaded gasoline UST. The new
tanks were removed in 1990.
Closure not yet granted.
SA 048
One 375-gallon UST, removal date not specified.
Closure granted in 1996.
SA 059
One 500-gallon diesel UST and one 200-gallon
gasoline UST, both removed in 1988.
Closure granted in 1995.
SA 078
One 3,100-gallon diesel UST removed in 1985.
Closure granted in 1999.
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 079
Four fuel and lubricant USTs ranging from 265
gallons to 10,000 gallon, all removed in 1989.
Closure not yet granted.
SA 086
Four 1,000-gallon waste oil USTs, removal date
not specified.
Closure granted in 1996.
Notes: AOC
area of concern
CS
confirmed site
CSM
conceptual site model
OWS
oil and water separator
PRL
potential release location
SA
study area
UST
underground storage tank
Sources:
Follow-on Strategic Sites RICS Addenda and FS (CH2MHill, 2012).
Small Volume Sites RICS Addenda and FS (CffiMHill, 2011).
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Summary of SVE Systems and Bioventing Systems
SYK System
SYK System Description
lOSK I #2 (iroup 2
Action Sites
within ROI of
SYK System
IC 23 SVE System
Status: Decommissioned December 2011
Primary COCs: TCE; 1,1-DCE; 1,2-DCA
Cumulative Mass Removed: 4,260 lbs.
PRL L-002
SA 047
IC 25 SVE System
Status: Decommissioned December 2011
Primary COCs: TCE; Carbon Tetrachloride
Cumulative Mass Removed: 56 lbs.
SA 037
SA 038
SA 040
SA 048
IC 27 SVE System
Status: Decommissioned December 2006
Primary COCs: TCE; Carbon Tetrachloride
Cumulative Mass Removed: 431 lbs.
SA 053
SA 058
SA 059
IC 29 SVE System
Status: Decommissioned December 2011
Primary COCs: TCE; 1,2-DCA; Carbon
Tetrachloride; 1,1,2,2-PCA; Chloroform;
Naphthalene; 1,2,4-TMB
Cumulative Mass Removed: 1,650 lbs.
CS S-021
CS T-037
PRL L-002
PRL P-003
PRL S-022 & SA 069
SA 067
SA 068
IC 30 SVE System
Status: Decommissioned December 2011
Primary COCs: TCE; 1,2-DCA
Cumulative Mass Removed: 125 lbs.
PRL L-002
IC 31 SVE System
Status: Decommissioned January 2016
Primary COCs: TCE; 1,2-DCA; cis-l,2-DCE
Cumulative Mass Removed: 6,356 lbs.
CS S-021
CS T-037
PRL L-002
PRL P-004
SA 102
IC 32 SVE System
Status: Decommissioned December 2011
Primary COCs: 1,2-DCA; Naphthalene
Cumulative Mass Removed: 1,205 lbs.
PRL T-019
SA 101
IC 34 SVE System
Status: Decommissioned October 2014
Primary COCs: TCE; 1,2-DCA
Cumulative Mass Removed: 225 lbs.
PRL L-004
IC 35 SVE System
Status: Decommissioned October 2014
Primary COCs: cis-l,2-DCE; 1,2-DCA;
Carbon Tetrachloride; TCE
CS P-005
CS P-006
PRL L-003 (F2)
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SYK System
SYK System Description
lOSK I #2 Group 2
Action Sites
within KOI of
SYK System
Cumulative Mass Removed: 1,855 lbs.
PRL T-015
SA 079
SA 094
IC 37 SVE System
Status: Operational, shut down for rebound
assessment March 2017
Primary COCs: TCE; Benzene; Carbon
Tetrachloride; PCE; cis-l,2-DCE; 1,2-DCA
Cumulative Mass Removed: 13,936 lbs.
CS S-027
PRL L-004
SA 077
PRL T-044 SVE
System
Status: Decommissioned June 2009
Primary COCs: TCE; PCE; cis-l,2-DCE
Cumulative Mass Removed: 3,510 lbs.
PRL L-001 (F2)
PRL T-033
AOC 325 Bioventing
System
Status: Decommissioned
Primary COCs: TPH-D; TPH-G; TPH-JP4
AOC 325
SA 038 Bioventing
System
Status: Shut down since September 2003
Primary COCs: TPH-D; TPH-G
SA 038
Notes: AOC
area of concern
COC
contaminant of concern
CS
confirmed site
DCA
dichloroethane
DCE
dichloroethene
F2
the portion of the IRP site within FOSET #2
IC (#)
Investigation Cluster
lbs
pounds
PCA
tetrachloroethane
PCE
tetrachloroethene
PRL
potential release location
ROI
radius of influence
SA
study area
SVE
soil vapor extraction
TCE
trichloroethene
TMB
trimethylbenzene
TPH-D
diesel range total petroleum hydrocarbons
TPH-G gasoline range total petroleum hydrocarbons
TPH-JP4 jet fuel range total petroleum hydrocarbons
Sources: Final PRL T-044 STOP Evaluation (URS, 2009).
Small Volume Sites RICS Addenda and FS, Appendix I - STOP Analyses (CH2MHill, 2011).
Follow-on Strategic Sites RICS Addenda and FS (CH2MHill, 2012).
Quarterly Groundwater and SVE Remediation Monitoring Report, Fourth Quarter 2016 (URS, 2017).
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ATTACHMENT C. SUMMARY OF SITE RISKS
Site
Residential Risk
Commercial/Industrial Risk
COC Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Soil
Shallow Soil Gas
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcino genie
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Soil
Shallow Soil Gas
AOC 325
1E-4
2
7E-5
2
7E-6
<1
4E-6
< 1
Arsenic*
Benzo(a)pyrene
Vanadium
Chloroform
Naphthalene
VOC3
Non-VOC2
CS P-005
8E-5
2
2E-5
2
5E-6
< 1
1E-6
< 1
Arsenic*
Aroclor 1260
Naphthalene
1.2.4-TMB
1.3.5-TMB
VOC2
Non-VOC2
CS P-006
4E-4
2
2E-3
9
4E-5
< 1
9E-5
< 1
Dioxins/Furans
Benzo(a)anthracene
Benzo(a)pyrene
Cadmium
PCE
TCE
Cis-1,2-DCE
1.2.4-TMB
1.3.5-TMB
VOC3
Non-VOC2
CS S-021
7E-5
< 1
1E-4
< 1
5E-6
< 1
7E-6
< 1
Arsenic*
PCE
TCE
Chloroform
Cis-1,2-DCE
1,2,4-TMB
1,4-DCB
VOC3
CS S-027
6E-5
< 1
2E-4
14
4E-6
< 1
1E-5
< 1
Arsenic*
Naphthalene
PCE
1,4-DCB
1.2.4-TMB
1.3.5-TMB
VOC3
CS T-037
1E-4
4
1E-4
< 1
6E-6
< 1
7E-6
< 1
Arsenic*
Aluminum*
Cobalt*
PCE
TCE
Cis-1,2-DCE
1,2,4-TMB
VOC3
CS T-059
4E-8
< 1
2E-5
1
1E-8
< 1
1E-6
< 1
None
Naphtlialene
1.2.4-TMB
1.3.5-TMB
VOC2
PRL L-001
(F2)
7E-4
5
1E-4
3
7E-5
< 1
7E-6
< 1
Arsenic
Vanadium
PAHs
PCE
TCE
Cis-1,2-DCE
1.2.4-TMB
1.3.5-TMB
VOC3
Non-VOC2
149
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Residential Risk
Commercial/Industrial Risk
COC Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Soil
Shallow Soil Gas
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcino genie
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Soil
Shallow Soil Gas
PRL L-002
2E-4
2
7E-2
422
2E-5
< 1
4E-3
29
Arsenic*
Cadmium
Benzo(a)pyrene
TCE
Cis-1,2-DCE
1,2,4-TMB
VOC3
Non-VOC2
PRL L-003
(F2)
1E-4
2
1E-4
1
1E-5
< 1
6E-6
< 1
Arsenic*
Aluminum*
Benzo(a)anthracene
Benzo(a)pyrene
PCE
TCE
Carbon Tetrachloride
VOC3
Non-VOC2
PRL L-004
1E-4
4
2E-4
58
1E-5
< 1
1E-5
4
Arsenic*
Cadmium*
2-methylnaphthalene
PCE
TCE
1,4-DCB
Naphthalene
Ethylbenzene
Cliloroform
Vinyl Chloride
1.2.4-TMB
1.3.5-TMB
VOC3
Non-VOC4a
PRL L-005
(F2)
1E-4
2
3E-4
3
8E-6
< 1
2E-5
< 1
Arsenic*
Vanadium
PCE
VOC3
PRL P-001
2E-6
1
1E-5
< 1
3E-7
< 1
8E-7
< 1
Cadmium
Vanadium
Aroclor-1254
Cliloroform
Carbon Tetracliloride
TCE
PCE
1,1-DCE
Naphthalene
Benzene
Non-VOC2
PRL P-003
N/A
N/A
2E-5
< 1
N/A
N/A
1E-6
< 1
None
PCE
TCE
Naphthalene
Ethylbenzene
Benzene
VOC2
PRL P-004
5E-5
< 1
1E-5
< 1
3E-6
< 1
6E-7
< 1
Arsenic*
TCE
Cliloroform
Cis-1,2-DCE
PCE
Benzene
VOC3
150
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Residential Risk
Commercial/Industrial Risk
COC Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Soil
Shallow Soil Gas
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcino genie
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Soil
Shallow Soil Gas
PRL S-022 &
SA 069
1E-4
1
6E-5
< 1
1E-5
< 1
4E-6
< 1
Arsenic*
Benzo(a)pyrene
PCE
TCE
Carbon Tetrachloride
Chloroform
VOC3
Non-VOC4a
PRL S-037
N/A
N/A
2E-5
< 1
N/A
N/A
1E-6
< 1
None
1,1,2,2-TCA
1,3-Butadiene
Carbon Tetrachloride
PCE
Ethylbenzene
Benzene
VOC2
PRL T-015
2E-8
6
5E-6
3
9E-9
< 1
3E-7
< 1
Thallium
1.2.4-TMB
1.3.5-TMB
Naphthalene
Ethylbenzene
Benzene
PCE
VOC2
Non-VOC4a
PRL T-019
1E-8
5
3E-6
< 1
1E-9
< 1
2E-7
< 1
Thallium*
Naphthalene
Benzene
PCE
TCE
Non-VOC2
PRL T-031
2E-4
6
2E-4
2
1E-5
< 1
1E-5
< 1
Arsenic*
Vanadium
Manganese*
Chloroform
Benzene
1,2,4-TMB
PCE
TCE
Cis-1,2-DCE
VOC3
Non-VOC2
PRL T-033
2E-4
5
9E-5
3
2E-5
< 1
5E-6
< 1
Arsenic*
Cadmium*
Vanadium*
Aroclor-1254
Aroclor-1260
PAHs
TCE
Chloroform
Naphthalene
N-propylbenzene
Xylenes
1.2.4-TMB
1.3.5-TMB
VOC3
Non-VOC2
SA 037
7E-5
5
6E-5
< 1
5E-6
< 1
3E-6
< 1
Arsenic*
Aluminum*
Thallium*
PCE
TCE
Chloroform
Benzene
VOC2
151
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Residential Risk
Commercial/Industrial Risk
COC Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Soil
Shallow Soil Gas
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcino genie
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Soil
Shallow Soil Gas
SA 038
N/A
N/A
5E-6
< 1
N/A
N/A
3E-7
< 1
None
Benzene
Ethylbenzene
Methylene Chloride
PCE
TCE
Chloroform
VOC2
Non-VOC2
SA 040
2E-4
6
1E-6
< 1
1E-5
< 1
9E-8
< 1
Arsenic*
Cadmium
Cobalt
Carbon Tetrachloride
Chloroform
Benzene
Ethylbenzene
PCE
TCE
VOC2
Non-VOC2
SA 043
8E-5
7
2E-5
< 1
6E-6
< 1
1E-6
< 1
Arsenic
Cobalt
Zinc
Cadmium
Benzene
Naphthalene
MTBE
PCE
TCE
Methylene Chloride
VOC2
Non-VOC2
SA 044
2E-9
7
N/A1
N/A1
3E-10
< 1
N/A1
N/A1
Thallium*
TCE
VOC3
SA 047
1E-4
5
1E-5
< 1
7E-6
< 1
7E-7
< 1
Arsenic*
Cadmium
Cobalt
Vanadium
Chloroform
PCE
TCE
Benzene
Ethylbenzene
Naphthalene
VOC2
Non-VOC2
SA 048
2E-10
< 1
3E-5
< 1
9E-11
< 1
2E-6
< 1
None
Benzene
Chloroform
Ethylbenzene
Methylene Chloride
MTBE
Naphthalene
VOC2
SA 053
5E-5
5
1E-4
< 1
3E-6
< 1
8E-6
< 1
Arsenic*
Thallium
TCE
PCE
Carbon tetrachloride
Ethylbenzene
Naphthalene
Chloroform
Hexachlorobutadiene
VOC3
152
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Residential Risk
Commercial/Industrial Risk
COC Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Soil
Shallow Soil Gas
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcino genie
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Soil
Shallow Soil Gas
SA 058
5E-5
< 1
2E-3
6
3E-6
< 1
1E-4
< 1
Arsenic*
Carbon Tetrachloride
Chloroform
PCE
VOC3
SA 059
4E-6
1
6E-6
< 1
5E-7
< 1
4E-7
< 1
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Aluminum
Vanadium
Naphthalene
Hexachlorobutadiene
Chloroform
Chloro methane
Benzene
Ethylbenzene
Methylene Chloride
PCE
1,4-DCB
TCE
VOC2
Non-VOC2
SA 067
4E-5
4
4E-6
< 1
3E-6
< 1
2E-7
< 1
Arsenic*
Cobalt*
Benzene
Ethylbenzene
Naphthalene
PCE
TCE
Chloroform
Vinyl Chloride
1,4-DCB
VOC3
SA 068
4E-7
6
1E-6
< 1
6E-8
< 1
9E-8
< 1
Cobalt*
Benzene
Ethylbenzene
1,4-DCB
PCE
TCE
Carbon Tetrachloride
Chloroform
Naphthalene
Methylene Chloride
VOC2
SA 071
2E-4
4
1E-5
< 1
1E-5
< 1
7E-7
< 1
Arsenic*
Cadmium
Vanadium
Chloroform
Methylene Chloride
PCE
TCE
Benzene
VOC2
Non-VOC2
SA 073
N/A1
N/A1
N/A1
N/A1
N/A1
N/A1
N/A1
N/A1
None
None
VOC2
Non-VOC2
153
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Residential Risk
Commercial/Industrial Risk
COC Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Soil
Shallow Soil Gas
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcino genie
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Soil
Shallow Soil Gas
SA 077
5E-5
< 1
3E-5
< 1
3E-6
< 1
2E-6
< 1
Arsenic*
Benzene
Carbon Tetrachloride
Ethylbenzene
1,4-DCB
Naphthalene
PCE
Chloroform
VOC2
SA 078
7E-5
< 1
4E-6
< 1
5E-6
< 1
2E-7
< 1
Arsenic*
Benzene
Carbon Tetrachloride
Chloroform
Ethylbenzene
Hexachlorobutadiene
Naphthalene
PCE
TCE
Non-VOC2
SA 079
1E-4
6
2E-4
58
1E-5
< 1
1E-5
4
Arsenic*
Aluminum
Cadmium
2-Methylnaphthalene
1,4-DCB
Chloroform
Ethylbenzene
Naphthalene
PCE
TCE
Cis-U-DCE
Vinyl Chloride
1.2.4-TMB
1.3.5-TMB
VOC3
Non-VOC2
SA 081
1E-4
3
7E-5
9
9E-6
< 1
5E-6
< 1
Arsenic*
Cadmium
Thallium
Dioxins
PAHs
Naphthalene
2-Methylnaphthalene
Vinyl Chloride
TCE
Xylenes
Naphthalene
1.2.4-TMB
1.3.5-TMB
VOC3
Non-VOC4a
SA 086
3E-7
2
1E-5
12
2E-7
< 1
8E-7
< 1
Cadmium*
Benzene
Ethylbenzene
Naphthalene
PCE
1.2.4-TMB
1.3.5-TMB
VOC2
Non-VOC2
154
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Site
Residential Risk
Commercial/Industrial Risk
COC Risk Drivers
Selected Remedial
Alternative(s)
Soil
Shallow Soil Gas
Soil
Shallow Soil Gas
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Carcinogenic
Risk
Non-carcino genie
HI
Carcinogenic
Risk
Non-carcinogenic
HI
Soil
Shallow Soil Gas
SA 094
5E-5
< 1
2E-5
< 1
4E-6
< 1
1E-6
< 1
Arsenic*
Benzo(a)pyrene
Benzene
Methylene Chloride
MTBE
Naphthalene
VOC2
Non-VOC2
SA 098
8E-5
< 1
2E-5
< 1
5E-6
< 1
1E-6
< 1
Arsenic*
Benzene
Ethylbenzene
Naphthalene
Chloroform
TCE
PCE
VOC2
SA 101
N/A1
N/A1
N/A1
N/A1
N/A1
N/A1
N/A1
N/A1
None
Chloroform
VOC3
SA 102
2E-4
2
7E-2
422
7E-6
< 1
4E-3
29
Arsenic*
2,4-Dinitrotoluene
TCE
PCE
Cis-U-DCE
1,2,4-TMB
VOC3
Non-VOC2
Notes: Green indicates a risk below the risk management range or an HI less than one, yellow indicates risk within the risk management range or an HI equal to one, and red indicates risk above the risk management range or an HI greater than one.
*Metals concentrations are below or within the range of background for soils, detected with an unreliable analytical method, or not considered to be representative of site contamination. Excluding the listed metal, the soil risk is below or at the low end of the risk management range and/or
the HI is less than 1.
1) Although additional data was collected during 2017 data gap sampling investigation, no risk assessments were conducted following the data collection, so the risk values have not been revised.
AOC area of concern
COC contaminant of concern
CS confirmed site
DCB dichlorobenzene
DCE dichloroethene
F2 the portion of the IRP site within FOSET #2
HI Hazard Index
MTBE methyl tert-butyl ether
N/A Not available, risk values were not calculated because samples were not collected, chemicals of potential concern (COPCs) were not identified, or sufficient data was not available
PAH polycyclic aromatic hydrocarbon
PCA tetrachloroethane
PCE tetrachloroethene
PRL potential release location
SA study area
TCE trichloroethene
TMB trimethylbenzene
VOC volatile organic compound
155
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
THIS PAGE INTENTIONALLY LEFT BLANK
156
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
ATTACHMENT D. RATIONALE FOR SELECTED REMEDIES AND SITE
FIGURES
AOC 325: This site consists of the 0.3-acre area between Building 1033 and former Building 1036, which
was formerly used as a hazardous waste storage area, and a small portion of Building 1033. A portion of
the IWL (PRL L-001) runs through AOC 325 from east to west. Surface spills from hazardous waste
storage areas at Building 1033 (engine testing and motor/generator repairs) and former Building 1036 (fuel
storage), or from a washrack east of former Building 1036 may have released contaminants to surface soil.
Additionally, contaminants may have been released to subsurface soil as a result of exfiltration from the
IWL and USTs. There are two USTs associated with former Building 1036: 1036A - 4,000 gallon diesel
UST, and 1036B - 2,000 gallon aviation fuel tank removed in 1996. A bioventing system was installed in
January 2010 to address TPH contamination. The USTs and bioventing system associated with former
Building 1036 were granted closure by the Central Valley Water Board on August 8, 2016. A bermed
storage area (concrete pad) is located in the northeastern side of the site, where former Building 1036 was
located. A second bermed area, located in the northwestern corner of AOC 325, may have supported a
hazardous waste storage area.
Selected Remedies: Alternatives VOC3 (ICs/ECs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; PAHs, and TPH in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 7 * 10~5 (from chloroform and naphthalene) and for
industrial use is 4 x 10"6 (from naphthalene), which are both within the risk management range. The HI is
2 (from naphthalene) for the unrestricted use scenario and is less than 1 for the industrial use scenario. In
addition, the TCE concentration in SSG at boring PT31SB006, located at Building 1033 just to the south
of AOC 325, exceeds the IC compliance level. This boring location is outside of the buffer zone associated
with PRL T-031, but is included within the VOC3 buffer zone associated with AOC 325. The COCs
identified in SSG are chloroform, naphthalene, PCE, and TCE.
Soil: Soil risk for unrestricted use is 1 x 10~4 (from arsenic and benzo(a)pyrene), which is at the high end
of the risk management range. Soil risk for industrial use is 7 x 10"6 (from arsenic), which is at the low end
of the risk management range. The HI is 2 (from arsenic and vanadium) for the unrestricted use scenario
and is less than 1 for the industrial use scenario. However, arsenic concentrations are within the range of
background for subsurface soils; therefore, arsenic was not identified as a COC. Excluding arsenic, the soil
risk is at the low end of the risk management range for the unrestricted use scenario. The COCs identified
in soil are benzo(a)pyrene, TPH-D, and TPH-G.
There are potential impacts to groundwater and surface water quality from TPH-D and TPH-G. TPH-D
and TPH-G were detected at maximum concentrations of 2,680 mg/kg, and 351 mg/kg, respectively, which
exceed levels for the protection of groundwater and surface water quality. There are potential impacts to
surface water quality from lead, but the result is below background levels.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.1 x 10~5 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for AOC 325 is commercial/industrial.
VOC3 was selected to prevent unrestricted use (the HI for unrestricted use is greater than 1) and to require
ECs to mitigate SSG for industrial users (multiple VOCs were detected at concentrations exceeding IC
compliance levels). VOC3 was selected over VOC2 because VOC2 may not be protective of industrial
users considering the number of VOCs exceeding IC compliance levels. ICs established by VOC3 will
restrict the use of the site and require the installation of ECs in any future buildings or during significant
remodeling of existing buildings to mitigate the potential for VOCs in SSG from migrating into buildings
and impacting occupants via the vapor inhalation pathway. The parcel and lots affected by the 100-foot IC
157
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
compliance buffer for VOC3 are Parcel C14, Lots 6, 8, and 17. Because portions of the IC compliance
buffer extend beyond the FOSET #2 boundary, soil vapor sampling along the site boundary may be
conducted to reduce or modify the extent of the IC compliance buffer zone.
Non-VOC2 was selected to prevent unrestricted use and address the potential impacts to surface water
quality using ECs. Current risks (without arsenic) are at the low end of the risk management range for
unrestricted use and less than the risk management range for industrial use. Non-VOC2 was selected over
the other non-VOC alternatives because site investigations determined that the past operation of the
bioventing system reduced TPH concentrations and that residual TPH contamination was not a threat to
groundwater quality. Non-VOC2 is protective and cost effective. The ICs and ECs require that if existing
surface covers on the site are removed or remodeled, sampling must be done, as surface cover must be
maintained, or other soil/sediment ECs implemented, as warranted as long as levels protective of surface
water quality as shown in Table 2-4 are exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
158
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
HAZARDOUS MATERIALS
STORAGE AREA \ CONCRETE \
APPROXI MATE LOCATION \
OF FORMER USTs \ \ A32SSBQ07 •,
AIW-1
35
B4
06 q
MW-ll
BEftM OUTLET -
r^ mw
67 4
¦ MW-2V
Wo W
CONCRETE
(ft-
MW-4
D5
A'W 2 ^ MW-5
82 *
i 68
m£ A325SBQQ4
A325SB009 "
--FWrt^ODT t
AOC 325
AG05SB030
:
-"0=
~
"¦—WASHRACK ' A325SB008
- A325SB005
\
AOCG-5
PRL L-001A j
^ A325SB002
^ EitRM OUTLET [
A
o
LEGEND
A
SOIL GAS BORING
•
SHALLOW BORING {0-15 FT BGS)
O
PREVIOUS BORING LOCATION
D
AIR INJECTION WELL
s
MONITORING WELL
O
MANHOLE
~
LIFT STATION
INDUSTRIAL WASTE LINES
ROADS
I I AOC 325
BUILDINGS
j FOLLQW-QN STRATEGIC SITES N
Note: Q
Analytical data associated with the locations |
shown in gray are not presented in the attachments. Feel
Figure D-l AOC 325 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento, CA
— —— CH2MHII I
159
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lot Number
| | FOSET #2 Action Site
100 Foot VOCs Compliance Buffer
Roads
Figure D-2 AOC 325 IC Compliance
IC Compliance Boundary Boundary Map
Boundary FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
160
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
CS P-005: This site is the location of former 600-feet long, 20-feet wide and 7-feet deep unlined drainage
ditch that conveyed surface water runoff from Buildings 473 and 475 (reciprocating aircraft engine repair
and test area) to Magpie Creek from 1943 to the early 1990s. Runoff from former engine repair and the
test area flowed into storm drains that emptied into the site, and then flowed north into Magpie Creek. In
the early 1990s, the ditch was rerouted to the west, and all but the southern end of site was filled with soil.
Currently, all but the extreme southern portion of the site is covered by Building 445 or asphalt. From
October 1999 to May 2008, the southern half of the site was under the influence of the former IC 35 SVE
system.
Selected Remedies: Alternatives VOC2 (ICs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; PCBs, pesticides, and dioxins/furans in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 2 x 10~5 (from naphthalene), which is within the risk
management range. SSG risk for industrial use is 1 x 10"6, which is at the low end of the risk management
range. The HI is 2 (from 1,2,4-TMB and 1,3,5-TMB) for the unrestricted use scenario and less than 1 for
the industrial use scenario. The COCs identified in SSG are naphthalene, PCE, 1,3,5-TMB and 1,2,4-TMB.
There is some uncertainty regarding SSG, because SSG samples were only collected at two locations
(CSP5SBB004 and CSP5SBB007), one of which is northeast of the site boundaries (CSP5SBB007).
Soil: Soil risk for unrestricted use is 8 x 10"5 (from arsenic), which is at the upper end of the risk
management range. However, excluding arsenic, soil risks are within the low end of the risk management
range for unrestricted use. Soil risk for industrial use is 5 x 10"6, which is within the risk management
range. The HI is 2 (from arsenic) for unrestricted use and less than 1 for industrial use. Arsenic exceedances
were detected using Method SW6010, which is deemed unreliable at the reported concentrations. Arsenic
data from Method SW7060 were within the range of naturally occurring background concentrations. Cobalt
was detected at a concentration exceeding the unrestricted use screening level and slightly exceeding the
range of concentrations in the background data set. The cobalt detection was isolated and is not considered
a source of contamination. PCBs concentrations in surface soil (0.078 mg/kg) exceed the cleanup level for
protection of human health.
There are potential impacts to surface water quality from dieldrin and dioxins/furans. While concentrations
of Aroclor-1260 exceed the cleanup level for human health, concentrations do not exceed the protection of
surface water quality level (0.17 mg/kg).
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 6 / 10~6 and may be higher when exposure to all pathways,
including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for CS P-005 is commercial/industrial.
VOC2 was selected to prevent unrestricted use (the HI for unrestricted use is greater than 1 and due to
uncertainty because SSG samples were only collected from two locations). VOC2 was selected over VOC3
because VOC2 is sufficiently protective of human health given the uncertainty in SSG characterization.
ICs established by VOC2 will prohibit unrestricted use of the property.
Non-VOC2 was selected to prevent unrestricted use and address the potential impacts to surface water
quality. Non-VOC2 was selected over Non-VOC4a because the ECs component of Non-VOC2 is
protective of surface water quality, will not disrupt current site use because no excavation will occur, and
is cost effective. The ICs and ECs require that if existing surface covers on the site are removed or
remodeled, sampling must be done, as surface cover must be maintained, or other soil/sediment ECs
implemented, as warranted as long as levels protective of surface water quality as shown in Table 2-4 are
exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
161
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
,005
o
LEGEND
¦ DUAL PHASE VAPOR EXTRACTION WELL
* SOIL OAS BORING
Cjj SURFACE SCRAPE/SEDIMENT SAMPLE
SHALLOW BORING (0-15 FT BGS)
MID TO DEEP BORING <»15FT BGS)
Q MANHOLE
INDUSTRIAL WASTE LINES
ROADS
BUILDINGS
I Ics P-005
IC BOUNDARY
Notes:
Small Volume Sites boring locations are shown in bold.
The analytical data for borings shown in can be
Found iri the OU A RICS (Jacobs, 2001).
VICINITY MAP
It
A.
1 4v
CS P-005
60
I
120
Figure D-3 CS P-005 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base,
Sacramento, CA
CH2MHILL
162
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
| Arnold Ave
Winona
Way
Legend Figure D-4 CS P-005 IC Compliance
200 Lot Number IC Compliance Boundary Boundary Map
I | FOSET#2 Action Site [___] Boundary FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, C/\
Roads — Lot Line
163
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
CS P-006: This site is a drainage ditch that accepts run-off from several source areas. The drainage ditch
was 1150 feet long and was previously unlined, but the northern portion was widened and lined with
concrete in 1980. The southern portion was backfilled in the late 1940s and Building 431 was constructed
over part of the former ditch, leaving about 260 feet of remaining drainage ditch that is 30 feet wide, and 9
feet deep. The ditch receives storm water, which overflows into Magpie Creek when it reaches a certain
level. The site may have been impacted by runoff from fire-training activities at adjacent site CS T-057
and nearby industrial areas that drain to the lined portion of the drainage ditch. The site was formerly under
the influence of the former IC 35 SVE system, which operated from June 1999 until May 2008.
Selected Remedies: Alternatives VOC3 (ICs/ECs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; metals, dioxins/furans, PAHs, and TPH in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 2 * 10~3 (from TCE and PCE), which is greater than the
risk management range. SSG risk for industrial use is 9 x 10"5 (from TCE and PCE), which is within the
risk management range. The HI is 9 (from 1,2,4-TMB, 1,3,5-TMB, and xylenes) for the unrestricted use
scenario and is less than 1 for the industrial use scenario. The COCs identified in SSG are benzene;
chloroform; cis-l,2-DCE; 1,2-DCA; ethylbenzene; naphthalene; PCE; TCE; vinyl chloride; 1,2,4-TMB;
and 1,3,5-TMB.
Soil: Soil risk for unrestricted use is 4 x 10"4 (from dioxins/furans, benzo(a)anthracene, and
benzo(a)pyrene), which is greater than the risk management range. Soil risk for industrial use is 4 x 10~5
(from dioxins/furans), which is within the risk management range. The HI is 2 (from dioxins/furans and
cadmium) for the unrestricted use scenario and is less than 1 for the industrial use scenario. Dioxins/furans
and cadmium have been identified as COCs.
There are potential impacts to groundwater quality from arsenic; however, the arsenic was detected using
Method SW6010, which is considered to be an unreliable method for arsenic. There are potential impacts
to surface water quality from TPH-D, dioxins/furans, and chrysene. The dioxin/furans contamination may
be associated with overlapping source sites CS T-057, SA 080, and SA 107
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.3 * 10~4 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for CS P-006 is commercial/industrial.
VOC3 was selected to prevent unrestricted use (the HI for unrestricted use is greater than 1) and to require
ECs to mitigate SSG for industrial users (multiple VOCs were detected at concentrations exceeding
industrial screening levels). VOC3 was selected over VOC2 in order to protect industrial users (with the
addition of ECs) due to the uncertainty regarding SSG characterization. The ECs will control migration of
soil gas to into indoor air. The parcels and lots affected by the 100-foot IC compliance buffer for VOC3
are Parcels Bl, B2, and Big, Lots 1, 118, 120, 123B, 123D, 212, and 219. Soil vapor sampling along the
site boundary may be conducted to reduce or modify the extent of the IC compliance buffer zone.
Non-VOC2 was selected to prevent unrestricted use and address the potential impacts to surface water
quality using ECs. Risks are greater than the risk management range for unrestricted use and within the
risk management range for industrial use. Non-VOC2 is protective of human health and includes ECs that
will be protective of surface quality. Non-VOC2 will effectively prevent unrestricted use. The ICs and
ECs require that if existing surface covers on the site are removed or remodeled, sampling must be done,
as surface cover must be maintained, or other soil/sediment ECs implemented, as warranted as long as
levels protective of surface water quality as shown in Table 2-4 are exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
164
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
0%3
STS7S0I7
———
yy"^WV0.v
/// ' &
. ¦ >0
/ // o- etu l
f- H®W*A
C$.&026
NT
SAQ52"
LEGEND
¦ DUAL PHASE VAPOR EXTRACTION WELL © STORM DRAIN
¦ SOIL VAPOR EXTRACTION WELl
~ SOU VAPOR MONITORING WELL
A SOIL GAS BORING
Cj) SURFACE SCRAP&SEOIMEMT SAMPLE
• SHALLOW BORING (0-15 FT BGS>
O MID TO DEEP BORING <>15 FT BGS»
O MANHOLE
~ IIFT 5TATIOH
M SUMP
Moms:
KSi» or* rfiOwn •r bokl
If TRANSFORMER
INDUSTRIAL WASTE LWIES
ROADS
I ICS P-006
IC BOUNDARY
Figure D-5 CS P-006 Site Features Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
- CH2MHILL
165
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lot Number
| I FOSET n Action Site
100 Foot VOCsCompliance Buffer
Roads
Figure D-6 CS P-006 IC Compliance
IC Compliance Boundary Boundary Map
Boundary FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base. Sacramento, CA
¦-it i na
166
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
CS S-021: This site consists of 31,000-square foot Building 351, which contained an ordnance shop, a
paint shop, and a cleaning shop. The building was also used for degreasing, machining, and blasting
operations. In the 1950s, Building 351 housed a hydraulic repair shop, an electrical equipment repair shop,
and a small-toll repair shop. Materials handled in Building 351 included solvents, VOCs, SVOCs, acids,
bases, fuels, oils, and paint. The building originally had six floor drains that were connected to the IWL.
As of 1997, five of the drains had been grouted, capped, or covered. Leaks from a former solvent UST
(located in the southeast corner of Building 351 and removed in 1989), a degreaser (located in the northwest
corner of Building 351), and releases from IWL drains located within Building 351 may have impacted the
subsurface soil. Spills or leaks from the degreaser may have impacted the surface soil. Additionally,
contamination from nearby sites SA 102 (washrack), leaking sections of the IWL (PRL L-002D), and CS
T-017 (tank farm) has affected soil gas and groundwater at CS S-021. CS S-021 was formerly under the
influence of the IC 29 and IC 31 SVE systems. The UST has not been granted closure. Soil samples were
collected to determine the presence of contamination as a result of releases from the UST, the IWL drains,
and the former degreaser. VOCs and TPH were detected at concentrations less than screening levels in soil
samples collected beneath and near the location of the former solvent UST.
Selected Remedy: Alternative VOC3 (ICs/ECs)
Contaminants Addressed: VOCs in SSG.
Shallow Soil Gas: SSG risk for unrestricted use is 1 x 10~4 (from TCE and PCE), which is at the upper end
of the risk management range. SSG risk for industrial use is 7 x 10"6 (from TCE and PCE), which is within
the risk management range. The HI is less than 1 for both the unrestricted and industrial use scenarios.
Although risk for industrial use is within the risk management range, there are multiple VOCs detected at
concentrations exceeding IC compliance levels and ECs are needed to mitigate SSG risk for industrial users.
The COCs identified in SSG are ethylbenzene; carbon tetrachloride; chloroform; 1,4-DCB; TCE; and PCE.
Soil: Soil risk for unrestricted use is 7 x 10~5 (from arsenic) and for industrial use is 5 x 10~6 (from arsenic),
both of which are within the risk management range. The HI is less than 1 for both the unrestricted and
industrial use scenarios. Arsenic is the main driver of soil risk, but soil concentrations are within the range
of background. Excluding arsenic, the soil risk is on the low end of the risk management range for
unrestricted use and below the risk management range for industrial use. No COCs have been identified in
soil at CS S-021.
There are potential impacts to groundwater quality from arsenic, but concentrations are within the range of
natural background. No potential impact to surface water quality is indicated.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.2 x 10~5 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for CS S-021 is commercial/industrial.
VOC3 was selected to prevent unrestricted use (SSG risk for unrestricted use is 1 x 10~4) and to require ECs
to mitigate SSG for industrial users (multiple VOCs were detected at concentrations exceeding industrial
screening levels). VOC3 was chosen over VOC2 because of the number of VOCs detected above IC
compliance levels. In addition, the long-term reliability and permanence of VOC3 will be increased relative
to VOC2 with the addition of ECs, which will control migration of soil gas into indoor air. ICs established
by VOC3 will restrict the use of the site and require the installation of ECs in any future buildings or during
significant remodeling of existing buildings to mitigate the potential for VOCs in SSG from migrating into
buildings and impacting occupants via the vapor inhalation pathway. The parcel and lots affected by the
100-foot IC compliance buffer for VOC3 are Parcel A4d, Lots 98, 99, 100, 101, 104, and 108. Soil vapor
sampling along the site boundary may be conducted to reduce or modify the extent of the IC compliance
buffer zone.
167
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
168
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
-!
est
SA 067
PHLL-002B
,C3S21SSC05
J
FORMER'
EGREA3ER
X
CST37SB001^
LJC
OFFICES AND
STORAGF ROOMS
ORDNANCE
SHOP
CS S-021
CSS21SB0Q6
IVU
DRAIN
7
CSS21SB004
CSS21SB002
^\cSS21SB001,' ' \ V
LEGEND
¦ DUAL PHASE VAPOR EXTRACTION WELL INDUSTRIAL WASTE LINES
SOIL VAPOR MONITORING WELL ROADS
• SHALLOW BORING <0-15 FT BGS) | |cs S-021
IC BOUNDARY
O MID TO DEEP BORING (>15 FT BGS)
~ LIFT STATION
MANHOLE
[H TRANSFORMER
BUILDINGS
Notes
Small Volume Sites sample locations are shown in bold,
The analytical data for borings shown in a1 can be
found in the OU A RICS (Jacobs. 2001) and the most
recent SVE repots.
Jl
Figure D-7 CS S-021 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento, CA
CH2MHIU
VICNITY MAP
S-021
169
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Arnold Ave
Legend
200 Lo! Number IC Compliance Boundary
| | FOSET #2 Action Site Boundary
100 Foot VOCs Compliance Buffer * Loi Line
Roads
Figure D-8 CS S-021 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base,
Sacramento, CA
170
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
CS S-027: This site consists of a former solvent supply and recovery system that included a 10,000-gallon
solvent above ground storage tank (AST), an oil water separator (OWS), a piping trench, and a solvent
distillation unit located in Building 478. CS S-027, which is about 1000 square feet, was at least partially
paved during site operations. All site features associated with the solvent supply and recovery unit and
Building 478 were demolished in 1994. Most of CS S-027 is now covered by gravel, with some pavement
present in the southern portion of the site. Spills from operations at the solvent supply and recovery unit,
the AST, and the OWS may have impacted the surface soil. Leaks from the piping trench, sump, and drain
may have impacted the subsurface soil. The OWS at this site has not been granted closure status. CS S-
027 was within the radius of influence of two IC 37 SVE wells.
Selected Remedy: Alternative VOC3 (ICs/ECs)
Contaminants Addressed: VOCs in SSG.
Shallow Soil Gas: SSG risk for unrestricted use is 2 * 10~4 (from naphthalene and 1,4-DCB), which is
greater than the risk management range. SSG risk for industrial use is 1 x 10"5 (from naphthalene and 1,4-
DCB), which is within the risk management range. The HI is 14 (from 1,2,4-TMB, 1,3,5-TMB, and
naphthalene) for the unrestricted use scenario and is less than 1 for the industrial use scenario. Although
risk for industrial use is within the risk management range, there are multiple VOCs detected at
concentrations exceeding industrial screening levels and ECs are needed to mitigate SSG risk for industrial
users. The COCs identified in SSG are naphthalene; 1,4-DCB; 1,2,4-TMB; 1,3,5-TMB; TCE; and PCE.
Soil: Soil risk for unrestricted use is 6 x 10"5 (from arsenic) and for industrial use is 4 x 10"6 (from arsenic),
both of which are within the risk management range. The HI is less than 1 for both the unrestricted and
industrial use scenarios. Arsenic is the main driver of soil risk, but concentrations in soil are within the
range of background. Excluding arsenic, soil risks are at the low end of the risk management range for
unrestricted use and below the risk management range for industrial use. No COCs have been identified in
soil at CS S-027.
While concentrations of TPH-D and TPH-G exceed screening levels, concentrations are shallow and do not
exceed the likely protection of groundwater quality levels (3,900 mg/kg and 220 mg/kg, respectively).
Arsenic concentrations in soil are within the range of natural background. No surface soil samples were
collected at this site.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.4 * 10~5 and may be higher when exposure to all
pathways, including groundwater, are considered. However, excluding arsenic, risk to a commercial/
industrial worker are based primarily on exposure to SSG, which is 1 x 10"5.
Rationale for Selected Remedy: The expected future land use for CS S-027 is commercial/industrial.
VOC3 was selected to prevent unrestricted use (SSG risk for unrestricted use exceeds the risk management
range and the HI for unrestricted use is greater than 1) and to require ECs to mitigate SSG for industrial
users (multiple VOCs were detected at concentrations exceeding IC compliance levels). VOC3 was
selected over VOC2 because VOC3 will better protect industrial users given the number of VOCs detected
above IC compliance levels. In addition, the long-term reliability and permanence of VOC3 will be
increased relative to VOC2 with the addition of ECs, which will control migration of soil gas into indoor
air. ICs established by V OC3 will restrict the use of the site and require the installation of ECs in any future
buildings or during significant remodeling of existing buildings to mitigate the potential for VOCs in SSG
from migrating into buildings and impacting occupants via the vapor inhalation pathway. The parcel and
lots affected by the 100-foot IC compliance buffer for VOC3 are Parcel B3, Lots 123C, 125,126, and 127A.
Soil vapor sampling along the site boundary may be conducted to reduce or modify the extent of the IC
compliance buffer zone.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
171
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
3327HP*^
CSS27SB002
FORMER PIPING
/ TRhNCH
FORMER
SOlVEN I
STORAGE X
AREA \
DRAIN
•7 PROG 1
CONCRETE
. BERM
PKL 1-004^'
FORMER OUAWTER
SEPARAIOR
FORMER m.OOO-OAi - "
"A0OVEGROUNO ¦
STORAGEJAMK
4* it 3' CONCRETE WW.I
LEGEND
~ SOIL GAS BORING —*r— FENCELINE
# SHALLOW BORING (0-15 FT BOS) ROADS
O MID TO DEEP BORING (>15 FT BGS) ¦ ,
I |CS S-027
MANHOLE
IC BOUNDARY
INDUSTRIAL WASTE LINES
BUILDINGS
The analytical data for borings shown in , can be
found in the OU ARICS (Jacobs. 2001)
Figure D-9 CS S-027 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
CM2MHILL
VICINITY
Notes:
Small Volume Sites Boring locations ere shown in bold
S-DZ7
172
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
100 200 300 400 500
i Feet
1276
I
Legend Figure D-10 CS S-027 IC Compliance
200 Lol Number IC Compliance Boundary Boundary Map
I I FOSET #2 Action Site | | Boundary FOSET #2 'G™P2 Action Sites Record of
j i ! Decision
100 Foot VOCs Compliance Buffer Lot Line Former McClellan Air Force Base, Sacramento,
Roads CA
173
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
CS T-037: This 50-square foot site is the former location of a 500-gallon Stoddard solvent UST contained
within an open-top and open-bottomed concrete vault. In 1989, the vault was reportedly and intentionally
filled with water above the level of the tank, and product from the tank was observed floating on the water.
When inspected in 1989, it was observed that a "homemade" 130-gallon tank had been mounted on the top
of the UST. No information is available about when the homemade tank was installed or what function it
served. The tank, the concrete vault, and 2 feet of soil from beneath the concrete pads were removed in
1989 and backfilled with clean soil. Currently, CS T-037 is paved, and the surrounding area is covered in
asphalt. CS T-037 was within the former radius of influence of the former IC 29 and IC 31 SVE systems.
Releases resulting from leaks in UST and associated piping may have impacted the subsurface soil. The
UST has not been granted closure. Given the lack of exceedances in soil samples near the former UST, soil
data indicate that either significant releases from the UST did not occur or that contaminated soil was
removed as part of the tank removal.
Selected Remedy: Alternative VOC3 (ICs/ECs)
Contaminants Addressed: VOCs in SSG.
Shallow Soil Gas: SSG risk for unrestricted use is 1 x 10~4 (from TCE and PCE), which is at the high end
of the risk management range. SSG risk for industrial use is 7 x 10"6 (from TCE and PCE), which is at the
low end the risk management range. The HI is less than 1 for both the unrestricted use and industrial use
scenarios. Although risk for industrial use is within the risk management range, there are multiple VOCs
detected at concentrations exceeding IC compliance levels and ECs are needed to mitigate SSG risk for
industrial users. The COCs identified in SSG are carbon tetrachloride, chloroform, 1,4-DCB, ethylbenzene,
PCE, and TCE.
Soil: Soil risk for unrestricted use is 1 x 10~4 (from arsenic), which is at the high end of the risk management
range. Soil risk for industrial use is 6 x 10"6 (from arsenic), which is at the low end of the risk management
range. The HI is 4 (from arsenic, aluminum, and cobalt) for the unrestricted use scenario and is less than 1
for the industrial use scenario. Arsenic and cobalt are the main drivers of soil risk, but concentrations of
both metals are within the range of natural background concentrations and the maximum detected
concentrations are less than the background values. Aluminum is also within the range of natural
background concentrations. Excluding arsenic, the soil risk is below the risk management range. Excluding
arsenic, aluminum, and cobalt, the soil HI is less than 1. No COCs for soil were identified at CS T-037.
There are potential impacts to groundwater quality from arsenic, but the maximum concentration was within
the range of background levels. No surface soil samples were collected, but surface releases at CS T-037
are not consistent with the CSM.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.3 x 10~5 and may be higher when exposure to all
pathways, including groundwater, are considered. However, excluding arsenic, risks to a commercial/
industrial worker are based primarily on exposure to SSG, which is 7 x 10~6.
Rationale for Selected Remedy: The expected future land use for CS T-037 is commercial/industrial.
VOC3 was selected to prevent unrestricted use (SSG risk for unrestricted use is 1 x 10~4) and to require ECs
to mitigate SSG for industrial users (multiple VOCs were detected at concentrations exceeding IC
compliance levels). VOC3 was selected over VOC2 because VOC3 will better protect industrial users
given the number of VOCs detected above IC compliance levels. In addition, the long-term reliability and
permanence of VOC3 is greater than VOC2 with the addition of ECs, which will control migration of soil
gas into indoor air. ICs established by VOC3 will restrict the use of the site and require the installation of
ECs in any future buildings or during significant remodeling of existing buildings to mitigate the potential
for VOCs in SSG from migrating into buildings and impacting occupants via the vapor inhalation pathway.
The parcel and lots affected by the 100-foot IC compliance buffer for VOC3 are Parcel A4d, Lots 100 and
174
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
101. Soil vapor sampling along the site boundary may be conducted to reduce or modify the extent of the
IC compliance buffer zone.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
175
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 0€?
PRL L-002B
PZ-193
PZ-194
PZ-196
Figure D-ll CS T-037 Site Features
Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
CH2IVIHILL
T-037
'v /
ST37SBQ1
^/ST37SB02
location of
FORME* 300
GALLON fAMK
LEGEND
SOIL VAPOR MONITORING WELL
# SHALLOW BORING (0-15 FT BGS)
G MANHOLE
~ LIFT STATION
til TRANSFORMER
¦ INDUSTRIAL SNASJE LINES
ROADS
BUILDINGS
| |CS T-037
IC BOUNDARY
Note;
Small Volume Sites boring locations are shown in bold.
vicwrrv
176
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lot Number
| | FOSET #2 Action Site
100 Foot VOCs Compliance Buffer
Roads
Figure D-12 CS T-037 IC Compliance
IC Compliance Boundary Boundary Map
Boundary FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
111
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
CS T-059: This site is the former location of a 4,000-gallon UST (circa 1962-1987) that provided fuel for
a nearby service station. The UST was removed in 1987 and the site was reportedly backfilled with clean
soil. Closure was granted for the UST by the Central Valley Water Board in September 2000. Prior to
installation of the UST, a small southern portion of the site overlapped an area used for vehicle parking and
storage.
Selected Remedy: Alternative VOC2 (ICs)
Contaminants Addressed: VOCs in SSG.
Shallow Soil Gas: SSG risk for unrestricted use is 2 * 10~5 (from naphthalene) and for industrial use is
1 x 10 6, both of which are within the risk management range. The HI is equal to 1 (from naphthalene,
1,2,4-TMB, and 1,3,5-TMB) for unrestricted use and less than 1 for industrial use. However, there is
uncertainty regarding SSG because only one SSG sample was collected for this site. The COC in SSG is
naphthalene.
Soil: Soil risk for unrestricted use is 4 x 10~8 and for industrial use is 1 x 10~8, both of which are less than
the risk management range. The HI is less than 1 for both use scenarios. No COCs were identified in soil.
Soil data do not indicate potential impacts to surface water or groundwater quality. Arsenic in a single
sample was detected at a concentration (12.4 mg/kg) slightly above background (12 mg/kg); however, this
sample was analyzed using Method SW6010, which is considered unreliable for arsenic.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.01 * 10~6 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for CS T-059 is commercial/industrial.
VOC2 was selected to prevent unrestricted use. VOC2 was selected over VOC3 because VOC2 is
sufficiently protective of human health given the uncertainty regarding characterization of SSG and is more
cost effective. NFA would not be protective given the uncertainty regarding SSG characterization.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
178
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
LEGEND
A SOIL GAS BORING
0 HANDAUGER
O MID TO DEEP BORING {>15 FT BGS)
INDUSTRIAL WASTE LINES
» FENCE
——RAILROAD
ROADS
BUILDINGS
1 lCST-059
IC BOUNDARY
[
\
Js
J*
CS T-059
Figure D-13 CS T-059 Site Features
Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
— . —: CH2MIIILL.
179
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lot Number
| | FOSET #2 Action Site
Roads
Figure D-14 CS T-059 IC Compliance
IC Compliance Boundary Boundary Map
Boundary FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
180
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL L-001 (F2): This site is the location of an underground IWL that transports wastewater generated
from numerous industrial facilities to the Industrial Waste Treatment Plant (IWTP). Potential IWL leaks
as a result of deteriorated pipes and/or offset joints, lift stations, manholes, and sumps may have released
contaminants to subsurface soil. A short segment of the IWL line was within the radius of influence of the
former SVE system at PRL T-044.
PRL L-001 (F2) includes the portions of the IWL within OUs F and G and the northern portion of OU H.
PRL L-001 (F2) extends into OU H approximately 400 feet south of Lift Station 1000 to the west-east length
of Price Avenue. The remainder of PRL L-001 in OU H was included in FOSET #1 and will be included
with the PRL L-001 A/B (Fl) remedy with the FOSET #1 Group 4 sites. It should be noted that the short
segment in OU G between Manholes 36A and Sump 1048, which was included in FOSET #1 (Parcel A4,
Lot 23, near PRL T-044) will be included with the PRL T-044 remedy with the FOSET #1 Group 4 sites.
Selected Remedies: Alternatives VOC3 (ICs/ECs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; PAHs, PCBs, TPH, and metals in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 1 x 10~4 (from PCE and TCE), which is at the high end
of the risk management range. SSG risk for industrial use is 7 x 10~6 (from PCE and TCE), which is at the
low end of the risk management range. The HI is 3 (from 1,2,4-TMB and 1,3,5-TMB) for the unrestricted
use scenario and is less than 1 for the industrial use scenario. Although risk for industrial use is within the
risk management range, there is uncertainty because the full length of the IWL has not been characterized.
The COCs identified in SSG are 1,2,4-TMB; benzene; chloroform; chloromethane; methylene chloride;
naphthalene; PCE; TCE; and vinyl chloride.
Soil: Soil risk for unrestricted use is 7 x 10~4 (from arsenic and PAHs), which is greater than the risk
management range. Soil risk for industrial use is 7 x 10~5 (from arsenic and PAHs), which is within the risk
management range. The HI is 5 (from arsenic and vanadium) for the unrestricted use scenario and is less
than 1 for the industrial use scenario. PCBs concentrations in surface soil (0.0862 mg/kg) exceed the
cleanup level for protection of human health. No COCs were identified in soil at PRL L-001 (F2) in the
RICS; however, benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene,
chrysene, dibenzo(a,h)anthracene, indeno(l,2,3-c,d)pyrene, lead, PCBs, TPH-G are identified as COCs in
soil because surface and near surface soil contamination along PRL L-001 is addressed as part of this site.
There are potential impacts to groundwater quality from arsenic, but arsenic concentrations are either within
the range or natural background or were measured using Method 6010, which is unreliable for this metal.
There are potential impacts to surface water quality from arsenic, lead, PAHs [benzo(a)anthracene,
benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, dibenzo(a,h)anthracene,
indeno(l,2,3-c,d)pyrene], TPH-G, and PCBs. The CSM for PRL L-001 does not support surface or near
surface releases, so nearby site activities (including aircraft maintenance and fuel/solvent storage) are most
likely the source of shallow soil contamination along this portion of the IWL; however, each site must have
a remedy to address the contamination within the site boundaries. For that reason, surface and near surface
soil contamination along PRL L-001 is addressed as part of this site.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 7.7 x 10~5 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for PRL L-001 (F2) is
commercial/industrial. VOC3 was selected to prevent unrestricted use (SSG risk for unrestricted use is 1
x 10"4 and the HI for unrestricted use is greater than 1) and to require ECs to mitigate SSG for industrial
users because there are uncertainties related to characterizing the length of the entire IWL. VOC3 was
selected over VOC2 because VOC2 may not be protective of industrial users considering the uncertainty
related to characterization along the length of the IWL. In addition, the long-term reliability and
permanence of VOC3 will be increased relative to VOC2 with the addition of ECs, which will control
181
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
migration of soil gas into indoor air. ICs established by VOC3 will restrict the use of the site and require
the installation of ECs in any future buildings or during significant remodeling of existing buildings to
mitigate the potential for VOCs in SSG from migrating into buildings and impacting occupants via the
vapor inhalation pathway. The parcel and lots affected by the 100-foot IC compliance buffer for VOC3 are
Parcels Bib, C14, and C16, Lots 3A, 3B, 4, 4A, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,
22, 23, 24, 25, 49, 49A, 49B, 49C, and 200. Because portions of the IC compliance buffer extend beyond
the FOSET #2 boundary, soil vapor sampling along the site boundary may be conducted to reduce or modify
the extent of the IC compliance buffer zone.
Non-VOC2 was selected to prevent unrestricted use and address the potential impacts to surface water
quality using ECs. Non-VOC2 will effectively prevent unrestricted use and includes ECs that will be
protective of surface water quality. The ICs and ECs require that if existing surface covers on the site are
removed or remodeled, sampling must be done, as surface cover must be maintained, or other
soil/sediment ECs implemented, as warranted as long as levels protective of surface water quality as
shown in Table 2-4 are exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
182
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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Figure D-15 PRL L-001 (F2) Site
Features Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
CH2MHILL
183
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lot Number
Boundary
FOSET#2 Action Site — -
IC C ompliance Boundary
100 FootVOCs Compliance Buffer
'— Lot Line
R oads
Figure D-16 PRL L-001 (F2) IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
I Former McClellan Air Force Base, Sacramento, CA
Sacramento, CA
184
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL L-002: This site is the location of an underground IWL (PRL L-002A-D) consisting of four segments
(A-D) located throughout IC 23, IC 29, IC 30, and IC 31 in OU A. The IWL is situated at depths ranging
from 5 to 13 feet bgs and was used to collect wastewater from buildings in this portion of former McClellan
AFB for treatment at an IWTP. Leaks from the IWL as a result of deteriorated pipes or offset joints may
have impacted subsurface soil. The maj ority of PRL L-002A-D was within the radius of influence of former
SVE systems (IC 23, IC 29, IC 30, and IC 31).
Selected Remedies: Alternatives VOC3 (ICs/ECs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; PAHs, TPH, and metals in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 7 x 10~2 (from TCE and ethylbenzene) and for industrial
use is 4 x 10"3 (from TCE), both of which are greater than the risk management range. The HI is 422 (from
cis-l,2-DCE, 1,2,4-TMB, and TCE) for the unrestricted use scenario and is 29 (from cis-l,2-DCE, 1,2,4-
TMB, and TCE) for the industrial use scenario. Almost all portions of PRL L-002 were within the radius
of influence of the former IC 23, IC 29, IC 30, and IC 31 SVE systems. The COCs identified in SSG are
benzene; carbon tetrachloride; chloroform; cis-l,2-DCE; ethylbenzene; naphthalene; 1,2,4-TMB,
1,3,5-TMB, PCE; TCE; and xylenes.
Soil: Soil risk for unrestricted use is 2 x 10"4 (from arsenic and benzo(a)pyrene), which is greater than the
risk management range. Soil risk for industrial use is 2 x 10"5 (from arsenic and benzo(a)pyrene), which is
within the risk management range. The HI is 2 (from arsenic and cadmium) for the unrestricted use scenario
and less than 1 for the industrial use scenario. Arsenic is the main driver of soil risk, but soil concentrations
are below natural background. Excluding arsenic, soil risks are within the risk management range for
unrestricted and industrial use. Cadmium only exceeded screening levels at two sample locations, so the
extent is isolated and limited. Benzo(a)pyrene concentrations (1.04 mg/kg) exceed the cleanup level for
protection of human health. No COCs were identified for soil at PRL L-002 RICS; however, cadmium,
lead, benzo(a)pyrene, TPH-G are identified as COCs in soil because surface and near surface soil
contamination along PRL L-002 is addressed as part of this site.
There are potential impacts to groundwater quality from arsenic. There are potential impacts to surface
water quality from arsenic and lead and to human health from lead. Arsenic concentrations were either
below the background level or were measured using Method 6010, which is unreliable for this metal. Soil
contamination detected during previous investigations and the SVS investigation is considered too shallow
to be attributable to leaks in the IWL. Although this shallow soil contamination is most likely related to
activities at nearby sites (including PRL S-017 near PRL L-002A, CS S-024 near PRL L-002C, and SA 102
near PRL L-002D), each site should have a remedy to address the contamination within the site boundaries.
For that reason, surface and near surface soil contamination along PRL L-002 is addressed as part of this
site.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 4 * 10~3 and may be higher when exposure to all pathways,
including groundwater, are considered. However, excluding arsenic, risks to a commercial/industrial
worker are primarily attributable to exposure to SSG, which is 4 x 10"3.
Rationale for Selected Remedies: The expected future land use for PRL L-002 is commercial/industrial.
VOC3 was selected to prevent unrestricted use and to require ECs to mitigate SSG for industrial users (SSG
risk for both industrial and unrestricted use exceeds the risk management range and the HI for both
industrial and unrestricted use is greater than 1). VOC3 was selected over VOC2 because VOC2 may not
be protective of industrial users considering the uncertainty related to characterization along the length of
the IWL. In addition, the long-term reliability and permanence of VOC3 will be increased relative to VOC2
with the addition of ECs, which will control migration of soil gas into indoor air. ICs established by VOC3
will restrict the use of the site and require the installation of ECs in any future buildings or during significant
remodeling of existing buildings to mitigate the potential for VOCs in SSG from migrating into buildings
185
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
and impacting occupants via the vapor inhalation pathway. The parcels and lots affected by the 100-foot
IC compliance buffer for VOC3 are Parcels A4d, Bid, B2, CIO, and E Lots 54, 58, 82A, 82B, 83, 95B, 96,
97, 98, 99, 100, 101, 102, 103, 104, 105, 107A, 107B, 108, 114B, 114C, 114D, 114F, 115A, 115C, 208,
and 209. Soil vapor sampling along the site boundary may be conducted to reduce or modify the extent of
the IC compliance buffer zone.
Non-VOC2 was selected to prevent unrestricted use and address the potential impacts to surface water
quality using ECs. Non-VOC2 will effectively prevent unrestricted use and includes ECs that will be
protective of surface water quality. The ICs and ECs require that if existing surface covers on the site are
removed or remodeled, sampling must be done, as surface cover must be maintained, or other soil/sediment
ECs implemented, as warranted as long as levels protective of surface water quality as shown in Table 2-4
are exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
186
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
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Figure D-17 PRL L-002 Site Features
Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base. Sacramento. CA
187
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
01 soft;
St
j
m Price Ave
200 400 600^800^1:000 i
, Feet^
Legend
200 Lot Number
Boundary
] FOSET #2 Action Site
IC Compliarvce Bourxlary
100 Foot VOCs Compliance Buffer
Lot Line
Roads
Figure D-18 PRL L-002 Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
188
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL L-003 (F2): This site is an underground IWL (PRL L-003A-B) located in the west-central portion of
OU A in the southeastern area of the former McClellan AFB, and is a main conduit of the IWL piping
system that transports industrial wastewater from five facilities (Buildings 443, 447, and 651, Tank Farm
1, and a washrack located in IC 35 and IC 36). The IWL is below ground at depths ranging from about 3
to 15 feet bgs and was in operation from the 1940s until the late 1990s. Most of PRL L-003B (the eastern
portion of PRL L-003) was within the radius of influence ofthe former SVE system at IC 35. Figure D-19
shows an arm ofthe IWL north of Manhole 431J that is located in Parcel Big, Lot 219, of FOSET #3; the
remedy for this portion of the IWL was selected in the Follow-On Strategic Sites ROD. Leaks from the
IWL as a result of deteriorated pipes or offset joints may have impacted the subsurface soil.
Selected Remedies: Alternatives VOC3 (ICs/ECs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; PAHs, and metals in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 1 x 10~4 (from PCE, TCE, and carbon tetrachloride),
which is at the high end of the risk management range. SSG risk for industrial use is 6 x 10"6 (from PCE,
TCE, and carbon tetrachloride), which is at the low end of the risk management range. The HI is 1 (from
PCE, TCE, and carbon tetrachloride) for the unrestricted use scenario and is less than 1 for the industrial
use scenario. Although risk for industrial use is within the risk management range, there is uncertainty
associated with characterizing the entire length of the IWL. The COCs identified in SSG are benzene,
carbon tetrachloride, chloroform, naphthalene, PCE, and TCE.
Soil: Soil risk for unrestricted use is 1 x 10"4 (from arsenic, benzo(a)anthracene, and benzo(a)pyrene),
which is at the high end of the risk management range. Soil risk for industrial use is 1 * 10"5 (from arsenic,
benzo(a)anthracene, and benzo(a)pyrene), which is within the risk management range. The HI is 2 (from
aluminum and arsenic) for the unrestricted use scenario and is less than 1 for the industrial use scenario.
Arsenic and aluminum are the main drivers of soil hazard, but concentrations of both are within the range
of natural background. Excluding arsenic and aluminum, soil risks are within the risk management range
and the HI is less than 1 for both unrestricted and industrial use; however, cadmium was under-represented
in the risk assessment. A maximum value of 0.96 mg/kg was considered in the risk assessment, but
concentrations up to 10 mg/kg were detected. Cadmium concentrations exceed the cleanup level and add
to the HI value (by approximately 1.5 for an HI of 3.5). Cadmium, benzo(a)pyrene, benzo(a)anthracene,
benzo(b)fluoranthene, benzo(k)fluoranthene, indeno(l,2,3-c,d)pyrene, and chrysene were identified as
COCs in soil.
There are potential impacts to groundwater quality from arsenic. There are potential impacts to surface
water quality from chrysene.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.6 * 10~5 and may be higher when exposure to all
pathways, including groundwater, are considered. However, excluding arsenic and aluminum, risks to a
commercial/industrial worker are primarily from exposure to SSG, which is 6 x 10~6.
Rationale for Selected Remedies: The expected future land use for PRL L-003 (F2) is
commercial/industrial. VOC3 was selected to prevent unrestricted use (SSG risk for unrestricted use is 1
x 10"4) and to require ECs to mitigate SSG for industrial users associated with uncertainties related to
characterizing the length of the entire IWL. VOC3 was selected over VOC2 because VOC2 may not be
protective of industrial users considering the uncertainty related to characterization along the length of the
IWL. In addition, the long-term reliability and permanence of VOC3 will be increased relative to VOC2
with the addition of ECs, which will control migration of soil gas into indoor air. ICs established by VOC3
will restrict the use of the site and require the installation of ECs in any future buildings or during significant
remodeling of existing buildings to mitigate the potential for VOCs in SSG from migrating into buildings
and impacting occupants via the vapor inhalation pathway. The parcels and lots affected by the 100-foot
IC compliance buffer for VOC3 are Parcels Blc, Big, and B2, Lots 120, 123A, 123B, 123C, 123D, 204,
189
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
205, 206, 207, and 219. Soil vapor sampling along the site boundary may be conducted to reduce or modify
the extent of the IC compliance buffer zone.
Non-VOC2 was selected to prevent unrestricted use (the HI is greater than 1) and address potential impacts
to surface water quality using ECs. Non-VOC2 meets the threshold criteria, will effectively prevent
unrestricted use, and includes ECs that will protect surface water quality. The ICs and ECs require that if
existing surface covers on the site are removed or remodeled, sampling must be done, as surface cover must
be maintained, or other soil/sediment ECs implemented, as warranted as long as levels protective of surface
water quality as shown in Table 2-4 are exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
190
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Former McClellan Air Force Base, Sacramento, CA
191
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
E Ac St
200 400
Legend
200 Lot Number IC Compliance Boundary
| Boundary [=] FOSET #2 Action Site
100 Foot VOCs Compliance Buffer Lot Line
Figure D-20 PRL L-003 (F2) IC
Compliance Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
Sacramento, CA
192
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL L-004: This site is the location of the underground IWL (PRL L-004A-B). Wastewater from both
lines A and B drained by gravity to Lift Station D, which is located near former Building 473A. Wastewater
from Lift Station D then flowed by gravity through the IWL system westward to the IWTP. Leaks from
the IWL as a result of deteriorated pipes or offset joints may have impacted the subsurface soil. The
majority of PRL L-004A was within the radius of influence of the former IC 34 and IC 37 SVE systems.
Only the northern portion of PRL L-004B (north and east of SA 060) was within the radius of influence of
the IC 37 SVE system.
Selected Remedies: Alternatives VOC3 (ICs/ECs) and Non-VOC4a (Excavation and Disposal-Restricted
Land Use)
Contaminants Addressed: VOCs in SSG; TPH and metals in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 2 * 10~4 (from PCE, TCE, 1,4-DCB, naphthalene,
ethylbenzene, chloroform, and vinyl chloride), which is greater than the risk management range. SSG risk
for industrial use is 1 x 10"5 (from PCE, TCE, 1,4-DCB, naphthalene, ethylbenzene, chloroform, and vinyl
chloride), which is within the risk management range. The HI is 58 (from 1,2,4-TMB, 1,3,5-TMB, and
PCE) for the unrestricted use scenario and is 4 (from 1,2,4-TMB,, 1,3,5-TMB, and PCE) for the industrial
use scenario. The COCs identified in SSG are benzene; 1,3-butadiene; carbon tetrachloride; chloroform;
1,4-DCB; ethylbenzene; hexane; hexachlorobutadiene; naphthalene; PCE; TCE; 1,1,2,2-PCA; 1,2,4-TMB;
1,3,5-TMB; and vinyl chloride.
Soil: Soil risk for unrestricted use is 1 x 10"4 (from arsenic), which at the top of the risk management range.
Soil risk for industrial use is 1 * 10"5 (from arsenic), which is within the risk management range. The HI is
4 (from arsenic and cadmium) for the unrestricted use scenario and is less than 1 for the industrial use
scenario. Arsenic, selenium, and thallium data by Method SW6010 were not used in the risk assessment
because sufficient data by methods other than SW6010 were available. Arsenic and cadmium are the main
drivers of soil risk, but isolated elevated concentrations of arsenic do not appear indicative of contamination
from Air Force activities. The HI (without arsenic) is still greater than 1. Cadmium, lead, TPH-D, and
TPH-G are the COCs identified for soil at PRL L-004A.
There are potential impacts to groundwater quality from arsenic (using methods other than SW6010),
thallium, TPH-D, and TPH-G. Thallium concentrations are considered to be within the range of
background. TPH-G exceeded the preliminary cleanup goal for groundwater protection and is considered
a COC for PRL L-004A. There are potential impacts to surface water quality from TPH-D, arsenic,
cadmium, and lead and to human health from lead. While concentrations of TPH-D exceed screening
levels, concentrations do not exceed the protection of surface water quality level (3,200 mg/kg). There are
also potential impacts to surface water quality from aluminum, but concentrations of aluminum were within
the range of background levels.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 2 * 10~5 and may be higher when exposure to all pathways,
including groundwater, are considered. However, excluding arsenic and cadmium, risks to a
commercial/industrial worker are primarily from exposure to SSG, which is 1 x 10"5.
Rationale for Selected Remedies: The expected future land use for PRL L-004 is commercial/industrial.
VOC3 was selected to prevent unrestricted use and require ECs to mitigate SSG for industrial users (SSG
risk for unrestricted use exceeds the risk management range and the HI for both industrial and unrestricted
use is greater than 1). VOC3 was selected over VOC2 because it is more protective of industrial users
given that the HI is greater than 1 for the industrial scenario and due to uncertainty related to
characterization along the length of the IWL. In addition, the long-term reliability and permanence of
VOC3 would be increased relative to VOC2 because of the inclusion of ECs, which will control migration
of soil gas into indoor air. ICs established by VOC3 will restrict the use of the site and require the
installation of ECs in any future buildings or during significant remodeling of existing buildings to mitigate
193
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
the potential for VOCs in SSG from migrating into buildings and impacting occupants via the vapor
inhalation pathway. The parcel and lots affected by the 100-foot IC compliance buffer for VOC3 are Parcels
B2 and B3, Lots 118, 119, 120, 121, 122A, 122B, 123A, 123B, 123C, 123D, 124, 125, 126, 127A, 128,
and 205. Soil vapor sampling along the site boundary may be conducted to reduce or modify the extent of
the IC compliance buffer zone.
Non-VOC4a was selected to address potential impacts to groundwater and surface water quality and prevent
unrestricted use. The target excavation volume is 6,210 cubic yards. However, contamination below 15
feet bgs is Air Force retained condition. Levels acceptable for industrial use will be achieved by excavation
and offsite disposal. Due to the complexity of the infrastructure at PRL L-004, it is recognized that
excavation of some contamination may not be possible and that bioventing may be necessary to address
TPH contamination with Regulatory Agency approval. Non-VOC4a was selected over Non-VOC4b
because contamination likely extends too deep for excavation to unrestricted use levels. In addition, future
site use is anticipated to be industrial; therefore, excavation to unrestricted use levels is not necessary. The
ICs and ECs require that if existing surface covers on the site are removed or remodeled, sampling must be
done, as surface cover must be maintained, or other soil/sediment ECs implemented, as warranted as long
as levels protective of surface water quality as shown in Table 2-4 are exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
194
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
LEGEND
GTOLMD^TERMONITQfliNGWEU.
¦ SOIL VAPOR fcXT RACTICJN WELL
^ set i. vapor ucwrrcaiHo vwi i
A SCL OAS BORNG
0 hMJ4CJMWfc»
SURFACE SCRAPOSCOflHEWT SAMPLE
• sH*ncweoRw«ro-isrrBC55j
O MID TO DEEP BOaWG(>15 FT BOSi
Notes
Smtf< Vo4jm» SSh tmnng taeslKXIi ar« shuiwi n bold.
toftwwfis shctwirt canlM
fcuna in 5v»CUA RfGS 1 Jacobs, 2001)
T«9»C vv'unji
(bImi than y
fe« t
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
IFGEHO
Q SOIL V»POR MONITOR:IMG WELL
A SOIL GAS BOEING
M HAND MJGER
£¦ SURFAC E SC iWEiSEDIM ENT SAMPLE
• WALLOW BORIMG <0-15 FT BSS>
~ MID TO OCer RCAIHC <>tS Ft &OSJ
¦© MANHOLE
LIFT STATION
n l QCATICW OF 1 EA<#K5 UANHOtF
ROADS
® STORM DRAW 1 IFSLL W
El TRANSFORMER C BOUNDARY
* APPROXIMATE LOCATION OF REPORTED BREAK BUILDINGS
WOySTRiAimSTE Lf-JES
Lt^E FAILED PRESSURE TESTING
LWt PASSED PRESSURE TESTING
LMEN0T TESTED
DJR6CTIOM OF fcVL FLOW <
____- y, y\
mUL4C3A / w
" \V7 " \
\JB/
Figure D-22 PRL L-004 Site Features
Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
CSS-027
PftLS-OSC
196
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Orange Grove Ave
'\117BX-
\
Legend
200 Lot Number
~ FOSET #2 Action Site
100 Foot VOCs Compliance Buffer
Roads
1C Compliance Boundary
Boundary
Lot Line
Figure D-23 PRL L-004 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
197
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL L-005 (F2): This site is the location of an underground IWL (PRL L-005G), that received wastewater
from eight facilities. The IWL consists of 2,900 feet of piping consisting predominantly of 15- to 18-inch
vitrified clay pipe and buried at depths between 11 and 19 feet bgs. The FOSET #2 portion of PRL L-005G
is approximately 2,000 feet long and includes the section of IWL between Manhole 16 and just east of
Manhole 19, plus the branch to Building 651. This segment of IWL runs east-west and connects the eastern
portion of Former McClellan AFB with the western portion and the IWTP. The IWL operated from 1940
to 1994 and transported materials including fuels, oils, paints, cyanide, acids, bases, metals, and
radionuclides. Leaks from the IWL as a result of deteriorated pipes or offset joints may have impacted the
subsurface soil.
Selected Remedy: Alternative VOC3 (ICs/ECs)
Contaminants Addressed: VOCs in SSG.
Shallow Soil Gas: SSG risk for unrestricted use is 3 * 10~4 (from PCE), which is greater than the risk
management range. SSG risk for industrial use is 2 x 10"5 (from PCE), which is within the risk management
range. The HI is 3 (from PCE) for the unrestricted use scenario and less than 1 for industrial use. Although
risk for industrial use is within the risk management range, there is uncertainty related to characterizing the
length of the entire IWL. The COCs identified in SSG at PRL L-005 are benzene, chloroform, 1,2-DCA,
1,4-DCB, ethylbenzene, naphthalene, PCE, TCE, 2-methylnaphthalene, 1,2,4-TMB, and 1,3,5-TMB.
Soil: Soil risk for unrestricted use is 1 x 10~4 (from arsenic), which is at the high end of the risk management
range. Soil risk for industrial use is 8 x 10"6 (from arsenic), which is at the low end of the risk management
range. The HI is 2 (from arsenic) for the unrestricted use scenario and is less than 1 for the industrial use
scenario. Arsenic is the main driver of soil risk, but soil concentrations are within the range of background.
Excluding arsenic, soil risks are below the unrestricted risk management range. No COCs have been
identified in soil at PRL L-005 (F2).
There are potential impacts to groundwater quality from arsenic. Arsenic concentrations are within the
range of background. No surface soil samples were collected. However, surface releases are not consistent
with the CSM for the IWL.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 2.8 / 10~5 and may be higher when exposure to all
pathways, including groundwater, are considered. However, excluding arsenic, risks to a
commercial/industrial worker come primarily from exposure to SSG, which is 2 x 10~5.
Rationale for Selected Remedy: The expected future land use for PRL L-005 (F2) is
commercial/industrial. VOC3 was selected to prevent unrestricted use (SSG risk for unrestricted use
exceeds the risk management range and the HI for unrestricted use is greater than 1) and to require ECs to
mitigate SSG for industrial users due to uncertainties related to characterizing the length of the entire IWL.
VOC3 was selected over VOC2 because VOC2 may not be protective of industrial users considering that
the HI is greater than 1 for the industrial scenario and the uncertainty related to characterization along the
length of the IWL. In addition, the long-term reliability and permanence of VOC3 would be increased
relative to VOC2 with the addition of ECs, which will control migration of soil gas into indoor air. ICs
established by VOC3 will restrict the use of the site and require the installation of ECs in any future
buildings or during significant remodeling of existing buildings to mitigate the potential for VOCs in SSG
from migrating into buildings and impacting occupants via the vapor inhalation pathway. The parcels and
lots affected by the 100-foot IC compliance buffer for VOC3 are Parcels B1 and Blc, Lots 148A, 148B,
149A, 206, and 207. Soil vapor sampling along the site boundary may be conducted to reduce or modify
the extent of the IC compliance buffer zone.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUC) prohibiting
residential and other sensitive uses.
198
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
LEGEND
4 SOIL GAS BORING
A SCREENING SOIL GAS BORlNG
O WD TO DEEP BORING (>15 FT BGSi
O manhoie
RAILROiAD TRACKS
ISM. FLOW DIRECTION
INDUSTRIAL WASTE UNES
IWL EX FILTRATION STATUS
NO POTENTIAL EXFILTRATION
MODERATE POfENTIAI EXF11TRATO*
I Ipsl l-oosg
I I^OSET A3 BOUNDARY
1 VERNAL POOL
BUILOINGS
=OL LOW-ON STRATEGIC SITES
Mctr
FotKNV- Qn SSi*:og!t StnsOTola lacattorsiMB
tflOWl l|> DCMd
Figure D-24 PRL L-005
(F2) Site Features Map
FOSET #2 Group 2 Action Sites
Record of Decision
Former McClellan Air Force Base,
Sacramento, CA
-CM2MHILL
199
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Taxiway J
RL L-005|
Dean St
Dudley Blvd
Mckinney
Legend
200 Lot Number IC Compliance
| 1 FOSET #2 Action Site | j Boundary
100 Foot VOCs Compliance Buffer Lot Line
Roads
Figure D-25 PRL L-005 (F2) IC
Boundary Compliance Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
200
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL P-001: This site comprises a former engine test cell, revetment area, and drainage ditch. Currently,
Building 877 (former administrative office and aircraft maintenance hangar), a parking lot, a grassy area,
and streets are present in this area. A diesel-powered backup generator and associated 250-gallon diesel
AST were located at this site. Activities such as cleaning, maintenance, and testing of reciprocating engines
took place at two portable test stands.
Building 877 is currently used by the California Department of Forestry and Fire Protection for maintaining
aircraft. Potential releases may have resulted from historical surface disposal practices, surface spills, and
leaks. Nearby IRP sites include PRL S-045 to southwest, AOC H-6 to east, AOC H-4 and AOC H-5 to
north, and AOC H-3 to northeast.
Selected Remedy: Alternative Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: PCBs in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 1 x 10"5 (from chloroform, carbon tetrachloride, TCE,
naphthalene, and benzene), which is within the risk management range. SSG risk for industrial use is
8 x 10"7, which is less than the risk management range. The HI is less than 1 for both the unrestricted use
and industrial use scenarios.
Soil: Soil risk for unrestricted use is 2 x 10"6 (from Aroclor-1254), which is at the low end of the risk
management range. Soil risk for industrial use is 3 x 10"7, which is less than the risk management range.
The HI is 1 (from vanadium) for the unrestricted use scenario and is less than 1 for the industrial use
scenario. The COC identified in soil are PCBs.
There are potential impacts to groundwater quality from arsenic; however, arsenic concentrations are less
than the background level. There are potential impacts to surface water quality from PCBs.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.1 x 10~6 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for PRL P-001 is commercial/industrial.
The preferred alternative is Non-VOC2 to prevent unrestricted use and address potential impacts to surface
water quality using ECs. Non-VOC2 will protect human health by prohibiting unrestricted use and includes
ECs to minimize or eliminate impacts to surface water by requiring that the surface cover be maintained.
Considering the relatively low risks under an unrestricted use scenario (2 x 10"6), ICs/ECs and monitoring
are preferable to excavation and off-site disposal. The ICs and ECs require that if existing surface covers
on the site are removed or remodeled, sampling must be done, as surface cover must be maintained, or other
soil/sediment ECs implemented, as warranted as long as levels protective of surface water quality as shown
in Table 2-4 are exceeded.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
201
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PP01SB003
PPQ1HAGQ5/
PP01HA006-
PP01HA002
PARKING
LOT
TRANSFORMER
PP01SB001
PP01SB004
PP01HA004
PP01SB002
GRASS
LEGEND
& HANDAUGER
0 SURFACE SCRAPE/SEDIMENT SAMPLE
+ SHALLOW BORING (0-15 FT BGS)
O MID TO DEEP BORING (>15 FT BGS)
® STORM DRAIN
INDUSTRIAL WASTE LINES
ROADS
~ PRLP-Q01
BUILDINGS
FOLLOWON STRATEGIC SITES
Note:
Follow-on Strategic Site sample locations
are shown in bold.
former Ditch,
CURRENTLY A SWALE
DRAINAGE D»TCH CUL^ERTED
BENEATH ROAD
Figure D-26 PRL P-001 Site Features
Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
CH2MH1LL
PRL S-045A PRL S-045C
. PP01HA003
STORM DKAIN
GRASS
- DITCH GRADED OR FILLED
PS45SS001
| ' PS45SB014
GRASS
VICINITY
P-001
202
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend Figure D-27 PRL P-001IC Compliance
Boundary Map
200 Lot Number B I IC Compliance Boundary
"1 ^ | | _ , FOSET #2 Group 2 Action Sites Record of Decision
J u _. ion e | | oun ary Former McClellan Air Force Base, Sacramento, CA
Roads Lot Line
Sacramento, CA
203
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL P-003: This site is the location of a former oil fill pit where mop carts were placed beneath aircraft
to collect the oil and hydraulic fluid drained from the aircraft. PRL P-003 is also the location of a former
150-gallon diesel UST, which was removed in 1990. There are no records of the location of the tank or if
it was given closure status. If the UST was not granted closure status, then it will need to be closed by the
Central Valley Water Board after the FOSET #2 Group 2 Action Sites ROD is completed. Possible leaks
from the fill pit, and from the nearby UST and associated piping pose the potential subsurface impacts.
PRL P-003 is currently filled with soil and covered with concrete. PRL P-003 was within the radius of
influence of the former IC 29 SVE system.
Selected Remedy: Alternative VOC2 (ICs)
Contaminants Addressed: VOCs in SSG.
Shallow Soil Gas: SSG risk for unrestricted use is 2 * 10~5 (from TCE, PCE, naphthalene, ethylbenzene,
and benzene) and for industrial use is 1 x 10~6 (from TCE, PCE, naphthalene, ethylbenzene, and benzene),
which are both within the risk management range. The HI is less than 1 for both the unrestricted use and
industrial use scenarios. Two older SSG sample locations (locations PLL2ASB001 and PLL2ASB012) are
located approximately 15 and 60 feet outside of the PRL P-003 site boundaries (the other previous soil gas
samples were collected deeper than 15 feet bgs). Based on the original SSG sampling, the COCs identified
in SSG are benzene, naphthalene, and TCE.
An interim SSG data gap investigation was completed in 2017 to verify the CSM and to collect supporting
information within the Site boundaries and included the collection of two SSG samples at 7 feet bgs
(locations PP03-SG-01 and PP03-SG-02). Chloroform, cis-l,2-DCE, PCE, and TCE were detected in the
2017 samples, but no VOCs were present at concentrations above the IC compliance levels. Therefore, no
additional SSG COCs were identified.
Soil: No COPCs have been identified in soil at PRL P-003. Thus, no carcinogenic risks or non-
carcinogenic hazards for soil exposures were calculated. Arsenic (detected by Method SW6020) was the
only analyte detected in soil that exceeded screening levels, but was below background.
Soil data do not indicate potential impacts to groundwater quality, but no surface water samples were
collected.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for exposure to SSG is 1 x 10~6 and may be higher when exposure to all pathways, including
groundwater, are considered. Risk was not calculated for exposure to soil.
Rationale for Selected Remedy: The expected future land use for PRL P-003 is commercial/industrial.
VOC2 was selected to prevent unrestricted use. VOC2 was selected overNFA considering that the risk for
unrestricted use is within the risk management range and the uncertainty related to characterization of SSG.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
204
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
CRt vol t
lAPPftOXiMATIr
LOCATION OF FORMET? -
15WUONOIESEH UST
, PP3SB02"sSs.
A oA.
PRL P-003
SA64HP2l',_ /
•Ol I
=^?V
it
PRL'L-0J?2A
PRL £-022
SA097
LEGEND
$ SOIL VAPOR MONITORING WELL
• SHALLOW BORING (0-15 FT BGS)
O MID TO DEEP BORING (>15 FT BGS)
0 MANHOLE
~ LIFT STATION
INDUSTRIAL WASTE LINES
ROADS
BUILDINGS
PRL P-003
IC BOUNDARY
Notes:
Small Volume Sites boring locations are shown in bold
The analytical data for borings shown in gray can be
found in the OU A RICS (Jacobs. 2001).
VieiWTY MAP
Jj
J. nj
/ PRL P-003
Figure D-28 PRL P-003 Site Features
Map
FOSET #2 Group 2 Action Sites Record of Decision
m Former McClellan Air Force Base, Sacramento, CA
-J
CH2MHILL
205
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lot Number
[ | FOSET #2 Artion Site
Roads
IC Compliance Boundary
Boundary
Lot Line
Figure D-29 PRL P-003 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellari Air Force Base, Sacramento, CA
206
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL P-004: This site consists of Lift Station F, two manholes, and a multiple line junction of the IWL.
This site received wastewater from Buildings 351, 362, 363, and 375, as well as facilities upstream of these
locations. Lift Station F consists of a sump that operated from approximately 1955 to 1991. PRL P-004
was within the radius of influence of an extraction well (EW-408) of the former IC 31 SVE system.
Selected Remedy: Alternative VOC3 (ICs/ECs)
Contaminants Addressed: VOCs in SSG.
Shallow Soil Gas: SSG risk for unrestricted use is 1 x 10~5 (from TCE, chloroform, benzene, and styrene),
which is within the risk management range. SSG risk for industrial use is 6 x 10~7, which is below the risk
management range. The HI is less than 1 for both use scenarios. Based on the original SSG data, the COCs
identified in SSG are chloroform and TCE. There is uncertainty regarding the initial SSG characterization;
although eight SSG samples were collected at four locations, these locations are located approximately 20
to 45 feet outside of the site boundaries (to the west, southwest and southeast). Prior to 2017, there were
no SSG samples collected within the boundaries of this site, where several IWL lines come together.
An interim SSG data gap investigation was completed in 2017 to verify the CSM and to collect supporting
information within the Site boundaries and included the collection of two SSG samples at 7 feet bgs
(locations PP04-SG-01 and PP04-SG-02). Benzene, chloroform, cis-l,2-DCE, 1,1-DCA, ethylbenzene,
PCE, TCE, 1,3,5-TMB, and vinyl chloride were detected in the 2017 samples, and the chloroform
concentration in one sample (PP04-SG-01-7.0) was above the IC compliance level. Based on the previous
data and the 2017 sampling, the COCs identified in SSG are chloroform and TCE.
Soil: Soil risk for unrestricted use is 5 x 10"5 (from arsenic) and for industrial use is 3 x 10"6, both of which
are within the risk management range. The HI is less than 1 for both use scenarios. Only arsenic and cobalt
were detected in soil at concentrations greater than any screening levels; however, they are not considered
to represent a source of contamination. Arsenic is the risk driver but was detected at a concentration less
than the background.
Soil data do not indicate potential impacts to groundwater. No surface soil samples have been collected at
this site, but since PRL P-004 is a multiple line junction of the IWL, surface soil contamination is not
consistent with the CSM.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 3.6 x 10~6 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for PRL P-004 is commercial/industrial.
VOC3 was selected to prevent unrestricted use (there is uncertainty regarding the initial SSG
characterization and chloroform concentrations exceed the IC compliance level in a recent sample collected
during the 2017 interim SSG data gap investigation). VOC3 was selected over VOC2 because it provides
protection for industrial users given the chloroform exceedance. The long-term reliability and permanence
of VOC3 is increased relative to VOC2 with the addition of ECs, which will control migration of soil gas
into indoor air. ICs established by VOC3 will restrict the use of the site and require the installation of ECs
in any future buildings or during significant remodeling of existing buildings to mitigate the potential for
VOCs in SSG from migrating into buildings and impacting occupants via the vapor inhalation pathway.
The parcel and lots affected by the 100-foot IC compliance buffer for VOC3 are Parcel A4d, Lots 101, 104,
and 108.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
207
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
LEGEND
# SHALLOW BORING <0-15 FT BGS)
O MID TO DEEP BORING {>15 FT BGS)
D LIFT station
O MANHOLE
INDUSTRIAL WASTE LINES
ROADS
BUILDINGS
| | PRL P-0Q4
IC BOUNDARY
Notes:
Small Volume Siles boong locations are shewn in bold.
Figure D-30 PRL P-004 Site
Features Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
CH2MHILL
208
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lot Number IC Compliance Boi
Boundary ~ FOSET #2 Action i
100 Foot VOCs Compliance Buffer Lot Line
Roads
Figure D-31 PRL P-004 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
hormer McClellan Air Force Base
Sacramento, C/4
209
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL S-022 & SA 069: PRL S-022 and SA 069 were evaluated together. PRL S-022 consists of Building
355 and SA 069 consists of Building 367. Building 355 has housed a number of operations since its
construction. In the 1940s and 1950s, the northern portion of Building 355 contained the carpentry shop,
the southern portion contained the welding shop, and the southern wing contained the battery shop. In the
1960s, the main section of Building 355 was converted to hydraulic and pneumatic repair shops.
During this time, there were hydraulic and solvent spray booths located in the southern wing of the building.
An aboveground bulk solvent tank was located adjacent to the southern wall of Building 355, east of the
former fuel USTs. There was a chemical degreaser located on the western side of Building 355, which was
used to clean various pieces of equipment being repaired in the hydraulic and pneumatic shops. In 1983,
the hydraulic and pneumatic repair shops moved out of Building 355 and the building was converted to
office space. The southern wing remained the battery repair shop. Approximately 80 batteries a month
were serviced at the battery shop.
This service included draining and refilling, which produced approximately 100 to 150 gallons of waste
sulfuric acid per month. The waste sulfuric acid was poured into 55 gallon drums that were periodically
transferred to 15-gallon containers and transferred to the plating shop (exact building on base is unknown).
Building 355 was vacated in 2001. A transformer location with oily staining on the concrete surrounding
the transformer was noted on the western side of Building 355.
Building 367 contained a steam-generation facility. Chemical-mixing tanks, on the southern side of
Building 367, were used to soften water upstream from the boilers. An IWL drain and sump adjacent to
the chemical tank area were used to drain excess fluid from the chemical mixing tanks, which had been
removed from the site. An oil/water runoff sump was used to collect oil/water discharges from the boilers.
A transformer is located at the northwestern corner of Building 367. The entire site is covered by asphalt
or concrete, and it is unlikely that any leaks or spills associated with a potentially leaking transformer
migrated to the soils below the concrete or asphalt.
Several former USTs located between PRL S-022 and SA 069 supplied fuel to the boilers used for steam
production in Building 367. There were two 21,000-gallon fuel oil USTs and two 20,000-gallon diesel fuel
storage USTs. The 21,000-gallon tanks (367A and 367D) were constructed of concrete and used to store
fuel oil; these tanks were abandoned in place in 1991 and 1995. Two 20,000-gallon USTs (367B and 367C)
were constructed of steel and were used to store diesel fuel. In 1996, tanks 367B and 367C (the steel diesel
USTs) were removed and replaced with tanks 367E and 367F. Tanks 367E and 367F were 20,000-gallon
tanks that were also used to stored diesel fuel. Use of the diesel tanks 367E and 367F was discontinued in
1998, when the boilers were converted to operate using natural gas. Tanks 367E and 367F were removed
in July 2003, along with the associated piping connecting them to Building 367. The USTs at PRL S-022
and SA 069 have not been granted closure status. Leaks from IWL drains and lines, a sump, abandoned
fuel oil USTs, former diesel USTs and associated lines, or the oil and boiler water runoff sump and chemical
mixing tanks may have impacted the subsurface soil and spills, leakage, and/or runoff from the solvent
AST, transformer, fuel pumps, solvent spray booths, hydraulic spray booth, and chemical degreaser at this
site may have impacted the surface soil. PRL S-022 and SA 069 were within the radius of influence of the
former IC 29 SVE system.
Selected Remedies: Alternatives VOC3 (ICs/ECs) and Non-VOC4a (Excavation and Disposal-Restricted
Land Use)
Contaminants Addressed: VOCs in SSG; TPH in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 6 * 10~5 (from PCE, TCE, carbon tetrachloride, and
chloroform) and for industrial use is 4 x 10"6 (from PCE, TCE, carbon tetrachloride, and chloroform), both
of which are within the risk management range. The HI is less than 1 for both the unrestricted use and
industrial use scenarios. The majority of the risks are based on a single sample, and there is uncertainty
about SSG concentrations surrounding PLS22SB013. There is also uncertainty regarding SSG
210
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
characterization other than the extent surrounding sample location PLS22SB013; although SSG samples
were collected at seven locations, only two of these locations are within the site boundaries. The COCs
identified in SSG are PCE; TCE; 1,1,2,2-PCA; benzene; carbon tetrachloride; and chloroform.
Soil: Soil risk for unrestricted use is 1 x 10"4 (from arsenic and benzo(a)pyrene), which is at the high end
of the risk management range. Soil risk for industrial use is 1 x 10"5 (from arsenic and benzo(a)pyrene),
which is within the risk management range. The HI is 1 (from arsenic) for the unrestricted use scenario
and is less than 1 for the industrial use scenario. Arsenic is the main driver of soil risk, but soil
concentrations are below background. Soil risks (without arsenic) are within the risk management range
for unrestricted use and at the low end of the risk management range for industrial use. The COCs identified
in soil are TPH-D, benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, chrysene, and naphthalene.
There are potential impacts to groundwater quality from TPH-D and arsenic and to surface water quality
from arsenic. In addition, arsenic exceedances were detected using Method SW6010, which is considered
unreliable for this metal. Detections of arsenic using the more reliable Method SW7060 are all below
background.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.4 * 10"5 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for PRL S-022 & SA 069 is
commercial/industrial. VOC3 was selected to prevent unrestricted use and to require ECs to mitigate SSG
for industrial users (due to uncertainties related to characterizing SSG). VOC3 was selected over VOC2
because it provides additional protection for industrial users considering the uncertainty related to
characterization of SSG. The long-term reliability and permanence of VOC3 will be increased relative to
VOC2 with the addition of ECs, which will control migration of soil gas into indoor air. VOC3 will restrict
the use of the site and require the installation of ECs in any future buildings or during significant remodeling
of existing buildings to mitigate the potential for VOCs in SSG from migrating into buildings and impacting
occupants via the vapor inhalation pathway. The parcel and lots affected by the 100-foot IC compliance
buffer for VOC3 are Parcel A4d, Lots 82A, 82B, 100, 102, 103, 104, 105, 106, and 107A. Soil vapor
sampling along the site boundary may be conducted to reduce or modify the extent of the IC compliance
buffer zone.
Non-VOC4a was selected to prevent unrestricted use and to address potential impacts to groundwater
quality. The target excavation volume is 1,940 cubic yards. Due to the complexity of the infrastructure at
PRL S-022 & SA 069, it is recognized that excavation of some contamination may not be possible and that
bioventing may be necessary to address TPH contamination with Regulatory Agency approval. These sites
have Air Force retained conditions for contamination below 15 feet bgs. Non-VOC4a was selected over
Non-VOC4b because restrictions will still be required for SSG, so PRL S-022 & SA 069 will not be
available for unrestricted use.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
211
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
-¦ .LVtttf
3CCTH ,MT1
ACO£l*«F
pssssem
LEGEND
¦ dual phase vapor extraction well
¦ SOIL VAPOR EXTRACTION WEI L
$ SOIL VAPOR MONITORING WELL
A SOIl GAS BORING
^ HAND AIJGER
SURFACE SCRAPt/SfcDlMEM I SAMPLE
• SHALLOW BORING 10-15 l"T BG5)
O MID TO DEEP BORING\» 15 ET BGSi
MANHOLE
IL LIFT STATION
QJ TRANSFORMER
- INDUSTRIAL WASTE UNES
ROADS
I I INDUSTRIAL USE TARGET VOLUME
BUILDINGS
I l=>RL S-022 AND SA 069
IC BOUNDARY
NCWV
Snail Volume S'tes and Soils Data Gso twr-ns
location* we $h(h*r in bold.
The awry»cai data •« bongs she*" In . car t>e
fjjund'tilfie OUARICS (Jnecfct. 2001J
Sorirgs n - have colconlriiruSn*
yetrim ihon PCSS
Tugci vCrfwroe &clindine& shwn vwtfi o JusfioJ ire src less
Mffiain llvan tiujsc sfown ««iti a scfid line Please see *t»« le-xl
tor turtfcw information.
Figure D-32 PRL S-022 & SA
069 Site Features and Target
Volume Map
FOSET #2 Group 2 Action Sites Record
of Decision
Former McClellan Air Force Base,
Sacramento, CA
212
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Howard
43th St
Legend
200 Lot Number
| | FOSET #2 Action Site
100 Foot VOCs Compliance Buffer-
Roads
IC Compliance Boundary
Boundary
Lot Line
Figure D-33 PRL S-022 IC
Compliance Boundary Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
213
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Howard St
107A
Legend
200 Lot Number
| | FOSET #2 Aiion Site
100 Foot VOCsCompliance Buffer
Roads
IC Compliance Boundary
Boundary
Lot Line
Figure D-34 SA 069 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
214
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL S-037: This site is the 1.5 acre location of former outdoor drum storage area. The eastern portion is
covered by asphalt and the western portion by concrete. The asphalt was reportedly cracked from
weathering. A shallow unlined drainage ditch is located to the south; surface runoff from PRL S-037 flows
south to the unlined drainage ditch and eventually into Arcade Creek. Releases resulting from leaks and/or
spills from historically stored drums containing solvents, oils, and automotive waste fluids may have
impacted surface soil.
Selected Remedy: Alternative VOC2 (ICs)
Contaminants Addressed: VOCs in SSG
Shallow Soil Gas: SSG risk for unrestricted use is 2 * 10"5 (from 1,3-butadiene, PCE, ethylbenzene, and
benzene), which is within the risk management range. SSG risk for industrial use is 1 x 10"6 (from 1,3-
butadiene, PCE, ethylbenzene, and benzene), which is at the low end of the risk management range. The
HI is less than 1 for both the unrestricted use and the industrial use scenario. Although risk for unrestricted
use is within the risk management range, there are multiple VOCs detected at concentrations exceeding
residential screening levels and ICs are needed to prevent unrestricted use. The COCs identified in SSG
are 1,3-butadiene, benzene, carbon tetrachloride, PCE, and 1,1,2,2-PCA.
Soil: Metals were detected at concentrations consistent with background levels. No COPCs have been
identified for soil at PRL S-037. Thus, no carcinogenic risks or non-carcinogenic hazards for soil exposures
were calculated.
There are potential impacts to groundwater and surface water from TPH-D; however, while concentrations
of TPH-D exceed screening levels, concentrations do not exceed the protection of surface water and
groundwater quality levels (3,200 mg/kg and 3,900 mg/kg, respectively).
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for exposure to SSG is 1 x 10~6 and may be higher when exposure to all pathways, including
groundwater, are considered. Risk was not calculated for exposure to soil.
Rationale for Selected Remedy: The expected future land use for PRL S-037 is commercial/industrial.
VOC2 was selected to prevent unrestricted use (multiple VOCs were detected at concentrations exceeding
residential screening levels). VOC2 is protective because unrestricted use will be prohibited and was
selected over NFA because NFA would not be protective given the multiple VOCs detected at
concentrations exceeding residential screening levels. ICs are needed to prevent unrestricted use.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
215
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
LEGEND
© HAND AUGER
(J) SURFACE SCRAPE/SEDIMENT SAMPLE
• SHALLOW BOR1NG (0-15 FT BGS)
O MID TO DEEP BORING (>15 FT BGS)
ROADS
~ PRL S-037
BUILDINGS
~ FOSS SITES
Figure D-35 PRL S-037 Site Features
Map
FOSET #2 Group 2 Action Sites Record of Decision
1?° Former McClellan Air Force Base, Sacramento, CA
Fee*
CH2MHILL
VICINITY MAP
S-037
216
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
»RL S-037'—i
Legend Figure D-36 PRL S-037 IC Compliance
200 Lot Number IC Compliance Boundary Boundary Map
"1 FOSET #2 Action Site I I Boundary FOSET #2 Group 2 Action Sites Record of Decision
Former McCiellari Air Force Base, Sacramento, CA
Roads Lot Line
217
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL T-015: This site is the location of former Tank Farm #1 (nine 50,000-gallon fuel USTs) and two
buildings (448 and 449) that served as fill stands. Buildings 448 and 449 were constructed in 1955. Prior
to the construction of these buildings, PRL T-015 was used intermittently for storage. The USTs were also
installed in 1955 and removed in 1997 along with associated piping. It is unknown if the fill used in the
excavation was tested. The USTs have not been granted closure status. The surface of the site is covered
with a mixture of gravel and vegetation. Spills from the fill stands may have impacted the surface soil, and
releases from leaks in USTs and piping may have impacted subsurface soil. PRL T-015 was within the
radius of influence of the former IC 35 SVE system.
Selected Remedies: Alternatives VOC2 (ICs) andNon-VOC4a (Excavation and Disposal-Restricted Land
Use)
Contaminants Addressed: VOCs in SSG; PCBs in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 5 * 10~6 (from naphthalene, benzene, ethylbenzene, and
PCE), which is at the low end of the risk management range. SSG risk for industrial use is 3 x 10"7, which
is below the risk management range. The HI is 3 (from 1,2,4-TMB and 1,3,5-TMB) for the unrestricted
use scenario and less than 1 for the industrial use scenario. The COCs identified in SSG are benzene,
ethylbenzene, naphthalene, PCE, TCE, 1,2,4-TMB, and 1,3,5-TMB.
Soil: Soil risk for unrestricted use is 2 x 10"8 and for industrial use is 9 x 10"9, both of which are below the
risk management range. The HI is 6 (from thallium) for the unrestricted use scenario and is less than 1 for
the industrial use scenarios. Thallium was detected using Method SW6010; however, this method is
considered unreliable for thallium. Excluding thallium, soil risks are below the risk management range for
both scenarios. Although they are not risk drivers, concentrations of benzo(a)anthracene, benzo(a)pyrene,
benzo(b)fluoranthene, benzo(k)fluoranthene, and naphthalene in soil exceed the soil cleanup levels in Table
2-3. The COCs identified in soil are Aroclor-1260, benzo(a)anthracene, benzo(a)pyrene,
benzo(b)fluoranthene, benzo(k)fluoranthene, and naphthalene.
There are potential impacts to groundwater quality from arsenic; however, most of the arsenic detections
were analyzed using Method SW6010, with is unreliable for this metal. Arsenic detections using Method
SW7060 were below the background level. There are potential impacts to surface water quality from
Aroclor-1260.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 3.1 x 10~7 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for PRL T-015 is commercial/industrial.
VOC2 was selected to prevent unrestricted use (the HI for unrestricted use is greater than 1). VOC2 was
selected over NFA because NFA is not protective of human health given that the HI is greater than 1 for
unrestricted use. Alternative VOC2 will be protective of human health and will effectively prevent
unrestricted use.
Non-VOC4a was selected to prevent unrestricted use and address potential impacts to surface water quality
using ECs. The target excavation volume is 60 cubic yards. NFA would not be protective of human health
because the HI is greater than 1 for the unrestricted use scenario. NFA would also do nothing to address
potential impacts to surface water quality. Non-VOC4a was selected over Non-VOC2 because the PCB
concentration at sample location PL2SB004 is over 100 times the unrestricted cleanup level and 50 times
the industrial cleanup level. Non-VOC4a will effectively prevent unrestricted use and includes ECs that
will be protective of surface water quality. The ICs and ECs require that if existing surface covers on the
site are removed or remodeled, sampling must be done, as surface cover must be maintained, or other
soil/sediment ECs implemented, as warranted as long as levels protective of surface water quality as shown
in Table 2-4 are exceeded.
218
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
219
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
EWAB3PH:2-v,
APPROKlMATfi LOCATION
0|: FORMB? U$T*
-0\
5A81FSB013-
PT15SB24-
PLT15SBQ10
PT15SB25
PLT15SB012-
EW-462
PT15SB07
PRLT-015
0r PT15SB06
0— PT15SB05
I— PLT15SB011
PT15SB04
«C3i>SB0l
PZ-362
PZ-363
PZ-364 I
'X-60S V
PZ-483
PZ-4M
PZ-465
L- PZ-478
^4— P2-479
PZ-40G
PZ-481
PT15SB28
I
0-PT15SBQ3
I
0- PT15SB02
- PLT15SB013
(Z>r- PT15SB01
^ PLT15SB008
MW-32B
H
« Vfj,
ATM - 400 »q.15 FT BGS)
IC BOUNDARY
r 1 INDUSTRIAL USE TARGET
yF
v PRLT-015
VOLUME
Notes:
Small Volume Sites boring locations are shown in bold.
The analytical data for borings shown in m can be
found in the OU ARICS (Jacobs. 2001).
3i -
Figure D-37 PRL T-015 Site Features
Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
CH2MHILL
220
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
] FOSET #2 Action Site | | Boundary FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
Roads Lot Line
221
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL T-019: This 18,000-square foot site is the location of the former UST farm known as Tank Farm
No. 5. The UST farm consisted of a fuel filling stand, loading area, and three 12,000-gallon USTs. The
USTs were installed in 1946 and used for storing aviation fuel and waste aviation fuel. The tanks and filling
equipment were removed in 1960, and the tank excavation was filled with clean soil. The exact location of
the fuel filling stand and loading area is unknown. The tanks have not been given closure status because
of contamination detected during previous investigations. The USTs will need to be closed by the Central
Valley Water Board after this ROD is completed. Releases during filling activities may have impacted the
surface soil, and releases from the USTs may have impacted the subsurface. PRL T-019 was within the
former radius of influence of the IC 32 SVE system.
Selected Remedy: Alternative Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: TPH in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 3 * 10~6 (from naphthalene, benzene, TCE, and PCE),
which is at the low end of the risk management range. SSG risk for industrial use is 2 x 10"7, which is
below the risk management range. The HI is less than 1 for both the unrestricted use scenario and the
industrial use scenario. No SSG COCs are identified at PRL T-019.
Soil: Soil risk for unrestricted use is 1 x 10"8 and for industrial use is 1 x 10"9, both of which are below the
risk management range. The HI is 5 (from thallium) for the unrestricted use scenario and less than 1 for
the industrial use scenario. Thallium is the main driver of soil risk, but elevated thallium detections are
most likely the result of an unreliable analytical method (Method SW6010) and not representative of site
conditions. Thallium was not detected at a concentration greater than the screening level in samples
analyzed using Method SW7421, which is considered reliable for thallium. Excluding thallium, soil risks
are below the unrestricted risk management range; however, the HI is still greater than 1. The soil COC is
thallium.
There are potential impacts to groundwater quality from thallium and arsenic, but data were obtained by
Method SW6010 and are considered unreliable. The arsenic concentrations detected by Method SW7060
showing potential impacts to groundwater are below background levels.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 2.01 * 10~7 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for PRL T-019 is commercial/industrial.
Non-VOC2 was selected to prevent unrestricted use (the HI is greater than 1). Non-VOC2 was selected
over NFA because NFA would not be protective of human health. Non-VOC2 will be protective of human
health.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
222
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PLT19SB005
o
MWM18
n
Q
PLT19SB014
LEGEND
m SOIL VAPOR EXTRACTION WELL
SOIL VAPOR MONITORING WELL
~ SOIL GAS BORING
O MID TO DEEP BORING (»15 FT BGS)
ROADS
~ PRLT-019
IC BOUNDARY
BUILDINGS
Notes:
Small Vdurne Sites boring locations are shown in bold
The analytical data for borings shown in can be
found in the OU A R6CS (Jacobs, 2001).
a
VICINffy M/»P
M. I
"• A
•' PRLT-019
Figure D-39 PRL T-019 Site Features
Map
FOSET #2 Group 2 Action Sites Record of Decision
4 J Former McClellan Air Force Base, Sacramento, CA
CH2MHILL
223
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
JPRLT-019U-,
48th
St
Myrtle Ave
Legend
200 Lot Number
| r l| FOSET #2 Action Site
Roads
IC Compliarvce Boundary
Boundary
Lot Line
Figure D-40 PRL T-019 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, G4
224
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL T-031: This site originally consisted of Buildings 1027 and 1028, both of which were constructed in
1957 and used primarily for aircraft maintenance. Beginning in 1994, the buildings stored office furniture,
administrative supplies, and military supplies and equipment of the 940th Division. Currently, Building
1027 is vacant and Building 1028 houses the aerospace museum. At least two USTs supported these
buildings' operations, one 500-gallon diesel UST (1028A) and one 500-gallon gasoline UST (1028B), both
located between Buildings 1027 and 1028. USTs 1028A and 1028B were removed in 1989, and an
unknown amount of soil was excavated. Both USTs received no further action designations by the Central
Valley Water Board in July 1999. Buildings 1032 and 1033 are outside the site boundary, but they were
included with the site in order to investigate additional hangars in an area that was not previously included
within an IRP site. These buildings also supported aircraft maintenance activities. Releases from USTs or
from light maintenance activities to floor drains and the IWL may have impacted subsurface soil. Releases
from transformers along Price Avenue may have impacted the surface soil.
Selected Remedies: Alternatives VOC3 (ICs/ECs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; metals in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 2 x 10~4 (from chloroform, PCE, and TCE), which is
greater than the risk management range. SSG risk for industrial use is 1 x 10"5 (from chloroform, PCE, and
TCE), which is within the risk management range. The HI is 2 (from PCE, TCE, and DCE) for the
unrestricted use scenario and less than 1 for the industrial use scenario. The COCs identified in SSG are
benzene, naphthalene, chloroform, PCE, and TCE.
Soil: Soil risk for unrestricted use is 2 x 10"4 (from arsenic), which is greater than the risk management
range. Soil risk for industrial use is 1 x 10~5 (from arsenic), which is within the risk management range.
The HI is 6 (from arsenic, vanadium, and manganese) for the unrestricted use scenario and less than 1 for
the industrial use scenario. Arsenic and manganese are the main drivers of soil risk, but soil concentrations
are within the range of natural background for arsenic or were analyzed using Method SW6010, which is
considered unreliable for arsenic. Excluding arsenic, soil risks are below the unrestricted risk management
range, but the HI is still greater than 1 for the unrestricted use scenario due to manganese and vanadium.
There are potential impacts to groundwater quality from arsenic, but soil concentrations are within the range
of natural variation of background or were analyzed using Method SW6010, which is considered unreliable
for arsenic. Note only one boring had multiple samples with arsenic detections that exceeded background.
There are potential impacts to surface water quality from PCBs; however, the reported concentrations do
not exceed the protection of surface water cleanup level (0.17 mg/kg).
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 2 / 10"5 and may be higher when exposure to all pathways,
including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for PRL T-031 is commercial/industrial.
VOC3 was selected to prevent unrestricted use (SSG risk for unrestricted use is greater than the risk
management range and the HI for unrestricted use is greater than 1). VOC3 was selected over VOC2
because it provides protection for industrial users given the elevated SSG concentrations. The long-term
reliability and permanence of VOC3 is increased relative to VOC2 with the addition of ECs, which will
control migration of soil gas into indoor air. ICs established by VOC3 will restrict the use of the site and
require the installation of ECs in any future buildings or during significant remodeling of existing buildings
to mitigate the potential for VOCs in SSG from migrating into buildings and impacting occupants via the
vapor inhalation pathway. The parcel and lots affected by the 100-foot IC compliance buffer for VOC3 are
Parcel C14, Lots 6, 10, 11, 20, and 21. Because portions of the IC compliance buffer extend beyond the
FOSET #2 boundary, soil vapor sampling along the site boundary may be conducted to reduce or modify
the extent of the IC compliance buffer zone.
225
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Non-VOC2 was selected to prevent unrestricted use (HI for unrestricted use is greater than 1). Non-VOC2
was selected over NFA because NFA would not be protective of human health.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
226
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
~=cr
3
I P e a J)
. 0
e e b
s> Qj"
OWtS
® 0 PLO1SB0I2
© X5
SfLL CONTHM€'<15 FT BGS)
© FLOOR DRAIN
© STORM DRAIN
H TRANSFORMER
Q M^JMHOLi
~ LIFT STATION
COLLECTION sump
INDUSTRIAL WASTE LINES
ROADS
< < SURFACE RUNOFF FLOW DIRECTION
I I PRL T-031
BUILDINGS
FOLLOW-ON STRATEGIC SITES
Kfltc:
FdiC7*-ari SSra!srjc S4e sample toca'ionr.
ore sftewii in bold
VICINITY MAP
- j sl
PRL T-031
Figure D-41 PRL T-031 Site Features Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
221
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
10D20C30C40C500
Legend
200 Lot Number
| | FOSET #2 Action Site
Roads
Lot Line
IC Compliance Boundary
100 Foot VOCsCompliar
Boundary
Figure D-42 PRL T-031 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
228
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL T-033: This site consists of Buildings 1020 and 1021 (aircraft maintenance hangars) and a former
aircraft wash area. Building 1022 (aircraft maintenance hangar) was also investigated as part of the site,
although it is outside the site boundary. During the early 1990s, the hangar buildings were extended and
the former aircraft wash area was completely covered. A segment of the IWL (PRL L-001A) runs through
the eastern portion of PRL T-033. Surface features at PRL T-033 include Buildings 1020 and 1021 and an
unpaved grassy area between the buildings. Releases from light maintenance activities to floor drains and
the IWL may have impacted the subsurface soil. Spills and leaks near the aircraft wash area and from
transformers located adjacent to Price Avenue east of Building 1021 may have impacted the surface soil.
The northeastern portion of PRL T-033 was within the former radius of influence of the PRL T-044 SVE
system.
Selected Remedies: Alternatives VOC3 (ICs/ECs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; metals, PAHs, and PCBs in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 9 * 10~5 (from TCE), which is at the upper end of the
risk management range, and for industrial use is 5 x 10~6 (from TCE), which is within the risk management
range. The HI is 3 (from n-propylbenzene, xylenes, 1,2,4-TMB, and 1,3,5-TMB) for the unrestricted use
scenario and less than 1 for the industrial use scenario. However, the TCE results at boring PT33SB005
(under Building 1021) were 2030 ppbv at 5 feet bgs and 516 ppbv at 15 feet bgs, which raises concerns
regarding exposure for current and future occupants at Building 1021. The COCs identified in SSG are
1,2,4-TMB, benzene, chloroform, chloromethane, naphthalene, PCE, TCE, and vinyl chloride.
Soil: Soil risk for unrestricted use is 2 x 10"4 (from arsenic, Aroclor-1254, Aroclor-1260, and PAHs), which
is greater than the risk management range. Soil risk for industrial use is 2 x 10~5 (from arsenic and PAHs),
which is within the risk management range. The HI is 5 (from cobalt, arsenic, cadmium, and vanadium)
for the unrestricted use scenario and less than 1 for the industrial use scenario. Arsenic, cadmium, cobalt,
and vanadium are the primary contributors to the soil risk, but arsenic and cadmium concentrations are
generally within the range of background, and vanadium concentrations do not exceed screening levels.
PAH contamination is addressed under source site PRL S-044. Excluding arsenic, cadmium, and vanadium,
soil risks are within the risk management range for unrestricted use and below the risk management range
for industrial use; however, the HI is still greater than 1 for unrestricted use due to cobalt. Lead
concentrations (229 mg/kg) exceed the cleanup level for protection of human health. Cadmium, cobalt,
lead, Aroclor-1254, and Aroclor-1260 are identified as COCs in soil at PRL T-033.
Soil data indicate potential impacts to groundwater quality from arsenic; however, arsenic concentrations
are within the range of natural background. There are potential impacts to surface water quality from
cadmium, lead, PAHs (benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, chrysene,
dibenzo(a,h)anthracene, indeno(l,2,3-c,d)pyrene), and PCBs.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 2.5 x 10~5 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for PRL T-033 is commercial/industrial.
VOC3 was selected to prevent unrestricted use (the HI for unrestricted use is greater than 1) and to require
ECs to mitigate SSG for industrial users (due to elevated TCE results beneath Building 1021). VOC3 was
selected over VOC2 because it provides protection for industrial users given the elevated TCE
concentrations beneath Building 1021. The long-term reliability and permanence of VOC3 is increased
relative to VOC2 with the addition of ECs, which will control migration of soil gas into indoor air. ICs
established by VOC3 will restrict the use of the site and require the installation of ECs in any future
buildings or during significant remodeling of existing buildings to mitigate the potential for VOCs in SSG
from migrating into buildings and impacting occupants via the vapor inhalation pathway. The parcel and
lots affected by the 100-foot IC compliance buffer forVOC3 are Parcel C14, Lots 6, 14, 15, 16, 23, 24, and
229
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
25. Because portions of the IC compliance buffer extend beyond the FOSET #2 boundary, soil vapor
sampling along the site boundary may be conducted to reduce or modify the extent of the IC compliance
buffer zone.
Non-VOC2 was selected to prevent unrestricted use (soil risk for unrestricted use is greater than the risk
management range and the HI for unrestricted use is greater than 1) and to address potential impacts to
surface water quality. Non-VOC2 was selected over Alternative Non-VOC4b because the site is covered
by buildings and asphalt, so use of ECs to maintain surface cover under Non-VOC2 will be protective. In
addition, unrestricted use would not be possible given the restrictions for SSG. The ICs and ECs require
that if existing surface covers on the site are removed or remodeled, sampling must be done, as surface
cover must be maintained, or other soil/sediment ICs and ECs implemented, as warranted as long as levels
protective of surface water quality as shown in Table 2-4 are exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
230
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
©
0
• PT33SB018
PT33SS002
TRENCH DRAIN
PT33SB015
PRL S-044
ILL CONTAINM£r;f
TANK
FORMER WRCRAFTvyASH ARE
PRL L-D01A
EXdWATEDAfiEA
PT33SB010
PS44SB0O5
LEGEND
A SOIL GAS BORING
$ SURFACE SCRAPE/SEDIMENT SAMPLE
• SHALLOW BORING (0-15 FT BGS)
O MID TO DEEP BORING (>15 FT BGS)
® FLOOR DRAIN
® STORM DRAIN
HI TRANSFORMER
O MANHOLE
fj LIFT STATION
03 SUMP
INDUSTRIAL WASTE LINES
ROADS
< < SURFACE RUNOFF FLOW DIRECTION
(J" ^300' SVE RADIUS OF INFLUENCE
I I PRL T-Q33
BUILDINGS
FOLLOW-ON STRATEGIC SITES
Notes:
Foliow-on Strategic Site sample locations
are in bold.
Soil gas data from borings In gray were collected
prior to or during Ihe operation of the PRL T-044
SVE system: therefore, they are not presented
in Ihe data attachments. Analytical data for
these locations can be found in the OU A RICS
(Jacobs. 2001) or the Soils Data Gap RICS
Addendum
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
iproce St
Redwooc^^
James W
Legend
200 Lot Number IC Compliance
| | FOSET #2 Action Site [___| Boundary
100 Foot VOCs Compliance Butter Lot Line
Roads
Figure D-44 PRL T-033 IC Compliance
Boundary Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
232
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 037: This 8,500-square foot site consists of Building 24 (a motor pool) and the location of a former
small storage shed to the northwest of the building. The former motor pool operated from 1939 until 1972.
The storage shed was removed in 1971. Since 1972, Building 24 has been used for administrative offices.
A new addition, approximately 60 feet by 40 feet, was added to the south end of Building 24 around 1992.
Automotive fluids, including fuels, oils, and solvents (generated from degreasing activities), were stored
and handled at Building 24 and the shed, and mineral oil contaminated with PCBs was also handled at the
site. Spills from motor pool operations and possible leaks or spills from storage shed may have impacted
surface soil. SA 037 was within the former radius of influence of the IC 25 SVE system.
Selected Remedy: Alternative VOC2 (ICs)
Contaminants Addressed: VOCs in SSG
Shallow Soil Gas: SSG risk for unrestricted use is 6 * 10~5 (from chloroform, benzene, TCE, and PCE)
and for industrial use is 3 x 10"6 (from chloroform, benzene, TCE, and PCE), both of which are within the
risk management range. The HI is less than 1 for both the unrestricted use scenario and the industrial use
scenario. Although risk for unrestricted use is within the risk management range, there are multiple VOCs
detected at concentrations exceeding residential screening levels and ICs are needed to prevent unrestricted
use. The COCs identified in SSG are chloroform and PCE.
Soil: Soil risk for unrestricted use is 7 x 10"5 (from arsenic) and for industrial use is 5 x 10"6 (from arsenic),
both of which are within the risk management range. The HI is 5 (from thallium, aluminum, and arsenic)
for the unrestricted use scenario and less than 1 for the industrial use scenario. Aluminum, thallium, and
arsenic are the primary contributors to the soil risk; however, aluminum and arsenic concentrations are
within the range of natural background, and thallium was detected with an unreliable method (Method
SW6010). Excluding aluminum, thallium, and arsenic, soil risks are below the unrestricted risk
management range. No COCs have been identified for soil at SA 037.
There are potential impacts to groundwater and surface water quality from arsenic, but the data indicate
that the detected concentrations are below background levels.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and S SG is 8 * 10~6 and may be higher when exposure to all pathways,
including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for SA 037 is commercial/industrial. VOC2
was selected to prevent unrestricted use (multiple VOCs were detected at concentrations exceeding
residential screening levels). VOC2 was selected over NFA because NFA would not be protective of human
health given that there are multiple VOCs detected at concentrations exceeding residential screening levels.
ICs are needed to prevent unrestricted use. VOC2 was selected over VOC3 because VOC2 is sufficiently
protective considering the relatively low risks for residential and industrial use.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
233
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
LTILlTr
vwer Bwes"
.APPROXIMATE .
WCATIDNCF -
-OWMKft SHED
iK>H VOLTAGE
RwrrnH eox
;'Y'
^ CONCRETE
I FOUNDATION
5A37SBQ13
• SA37SB017 ,SA37SRn<
- SA37SBQ14
SA 037
~wflW'--11 o r
SrA37HP0l3
»i.of /
w
PZ-465
PZ-456
PZ-457
SA37SB011 -
5I0EWAI> LANDSCAPES
/ or manicured <_^v\n
sAsrsscc
LEGEND
¦ SOIL VAPOR EXTRACTION WEL L
-V SOIL VAPOR MONITORING VUELL
~ SOIL GAS BORING
• SHAL LOW BORIN G (0-15 FT BGS)
O MID TO DEEP BORING (>15 FT BGS)
IYI TRANSFORMER
ROADS
~ SA037
SIDEWALK, LANDSCAPING,
OR MANICURED LAWN
|C BOUNDARY
BUILDINGS
Notes;
Small Volume Sites boring locations are shown in bold
The analytical data for bcongs shown »n • can be
found in the OU A RICS (Jacobs. 2001).
"fCitvrrr map
n
¦
J
SA 037
\_y
Figure D-45 SA 037 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
CH2MHILL
234
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
tegend
Roads Lot Line
Figure D-46 SA 037 IC Compliance Boundary
Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
235
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 038: This 5,000-square foot site consists of Building 26, which served as gas station from 1940 to
about 1990, and two former USTs. From 1940 to 1980, two 5,000-gallon USTs stored gasohol and leaded
gasoline. In 1980, these USTs were removed and replaced with a 5,000-gallon diesel UST and a 10,000-
gallon unleaded gasoline UST. These two USTs and associated piping were removed in 1990. The
pipelines were reportedly 4 inches in diameter and 3.5 inches long. The USTs were over-excavated to 13
feet bgs and backfilled with clean soil. The USTs have not been granted closure. Building 26 was most
recently used as a locksmith shop, but is not currently occupied. In 1997, a bioventing system was installed
to remediate TPH contamination. The bioventing system was recommended for shutdown and has been
inactive since September 2003. The southern portion of SA 038 was within the former radius of influence
of the IC 25 SVE system. Leaks from the USTs and associated piping may have impacted the subsurface
soil, and spills from fuel pumps may have impacted the surface soil.
Selected Remedies: Alternatives VOC2 (ICs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; TPHs in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 5 * 10~6 (from benzene, ethylbenzene, methylene
chloride, TCE, PCE, and chloroform), which is within the risk management range. SSG risk for industrial
use is 3 x 10 7 which is below the risk management range. The HI is less than 1 for both the unrestricted
use scenario and the industrial use scenario; however, the risks are based on a single sample location, and
there is some uncertainty regarding SSG concentrations to the north. The COCs identified in SSG are
benzene and chloroform.
Soil: No soil COPCs were identified at SA 038 in the human health risk assessment. Thus, no carcinogenic
risks or non-carcinogenic hazards for soil exposures have been calculated.
There are potential impacts to groundwater quality from arsenic, TPH-D, and TPH-G; however, the arsenic
concentrations were detected using Method SW6010, which is considered to be an unreliable method for
arsenic. Although there are no COCs present in soil that pose a human health risk, TPH-D and TPH-G
exceed groundwater protection preliminary cleanup goals, and data indicate that natural degradation of TPH
is still occurring. TPH-D and TPH-G are identified as COCs in soil at SA 038. No surface soil samples
were collected.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for exposure to SSG is 3 x 10~7 and may be higher when exposure to all pathways, including
groundwater, are considered. Risks from exposure to soil were not calculated.
Rationale for Selected Remedies: The expected future land use for SA 038 is commercial/industrial.
VOC2 was selected to prevent unrestricted use (there are uncertainties regarding the extent of SSG
contamination to the north). VOC2 was selected over NFA because there are uncertainties regarding SSG
characterization and NFA would not be protective of human health. VOC2 will effectively prevent
unrestricted use.
Non-VOC2 was selected to prevent unrestricted use and to include digging restrictions in order to prevent
exposure to deeper TPH contamination. Non-VOC2 was selected over NFA because NFA would not
prevent unrestricted use and prevent digging.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
236
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA38-SB-QQ4
SA38SB007U
SA38-VMP4-15
5A39-VMP4-30- "
oAaflPROOk
SA38SB010U Q
SA38-WV2,
m £
sazb- vMArt (OCAl ION
Of l.'STEKt-AVAriON
¦ SA38-VMP1-15
' 5/3S-VMfM-;W
•-HIGH VOlTAGE BQW
LEGEND
^ SOIL VAPOR MONITORING WELL
~ SOIL GAS BORING
O MFD TO DEEP BORING (>15 FT BGS)
m TRANSFORMER
ROADS
BUILDINGS
I | SAO 38
IC BOUNDARY
Notes:
The analytical data for borings shewn in ;, can be
found in the OU A RICS (Jacobs, 2001).
n
Figure D-47 SA 038 Site Features
Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
CH2MHILL
237
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Peacekeeper
Howard St
Lesend Figure D-48 SA 038 IC Compliance
200 Lot Number IC Compliance Boundary Boundary Map
I - ¦' | | , FOSET #2 Group 2 Action Sites Record of Decision
- ^ ' Former McClellan Air Force Base, Sacramento, CA
Roads Lot Line
238
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 040: This 35,000-square foot site includes a former electrical repair shop and civil engineering storage
area for construction materials and chemicals. Buildings 49, 50, 53, 56, and 58 were all located within SA
040, and the remainder of the site is paved. Materials handled at these buildings include acids, gas cylinders,
batteries, and solvents. The electrical repair shop was located on the eastern side of Building 53 (exterior)
and began operation in 1967. Drums and electrical maintenance equipment were stored in a "lean-to"
structure built directly on the asphalt. Building 58 is the only building that still exists onsite. All other
buildings have been removed and the site is completely covered in asphalt or by concrete foundations
(Building 53), and is currently divided by a fence. Materials typically stored included paint, oil, chemicals,
and other miscellaneous construction items. A gasoline spill was reported to have occurred in March 1993
at the former location of Building 53 (URS, 2000). The specific location and amount of gasoline released
is unknown. SA 040 was partially within the former radius of influence of the IC 25 SVE system.
Selected Remedies: Alternatives VOC2 (ICs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; metals and TPH in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 1 x 10~6 (from carbon tetrachloride, chloroform,
benzene, TCE, and PCE), which is at the low end of the risk management range. SSG risk for industrial
use is 9 x 10 s which is below the risk management range. The HI is less than 1 for both the unrestricted
use scenario and the industrial use scenario. No COCs have been identified for SSG at SA 040 based on
the older data. Prior to 2017, only two SSG samples were collected from a single location (SA40SB001)
at this 35,000-square foot site.
An interim SSG data gap investigation was completed in 2017 to verify the CSM and to collect
supporting information within the Site boundaries and included the collection of two SSG samples at 7
feet bgs (locations SA40-SG-01 and SA40-SG-02). Carbon tetrachloride, chloroform, PCE, and TCE
were detected in the 2017 samples, but no VOCs were detected at concentrations above the IC
compliance levels. No additional SSG COCs were identified. Uncertainty remains regarding SSG
characterization because three SSG samples locations are not sufficient to characterize the 35,000-square
foot site.
Soil: Soil risk for unrestricted use is 2 x 10~4 (from arsenic), which is greater than the risk management
range. Soil risk for industrial use is 1 x 10~5 (from arsenic), which is within the risk management range.
The HI is 6 (from arsenic, cadmium, and cobalt) for the unrestricted use scenario and less than 1 for the
industrial use scenario. Arsenic exceeded the background level in two samples, but these were analyzed
using Method SW6010, which is unreliable for this metal. Excluding arsenic, the soil risk is below the risk
management range for both unrestricted and industrial use; however, the HI is still greater than 1 for
unrestricted use due to cadmium and cobalt. Based on the older soil data, cadmium, cobalt, lead, and TPH-
D are identified as soil COCs.
An interim soil investigation for arsenic was completed in 2017 that included the collection of two samples
(one surface soil and one subsurface soil) from two locations (SA40-SB-01 and SA40-SB-02) and analysis
using Method SW6020. Arsenic was detected in all four samples, but all detections were below
background. Therefore, arsenic was not identified as a soil COC.
There are potential impacts to groundwater quality and to surface water quality from arsenic based on older
data, but these results were obtained by Method SW6010 and are considered unreliable. There are potential
impacts to surface water from cadmium, lead, and TPH-D, but SA 040 is completely paved by asphalt or
covered by former building foundations. ECs are needed to maintain the pavement and a soil management
plan is needed to address diesel in shallow soil.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1 * 10~5 and may be higher when exposure to all pathways,
including groundwater, are considered.
239
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Rationale for Selected Remedies: The expected future land use for SA 040 is commercial/industrial.
VOC2 was selected to prevent unrestricted use. VOC2 was selected over NFA because NFA would not be
protective of human health due to the uncertainties regarding SSG characterization of this 35,000 square
foot site. Considering the relatively low risks for residential and industrial use, VOC2 is protective and is
necessary given the uncertainty related to characterization of SSG. VOC2 will effectively prevent
unrestricted use.
Non-VOC2 was selected to prevent unrestricted use (the HI for unrestricted use is greater than 1) and to
address potential impacts to surface water quality using ECs. Soil risks (excluding arsenic) are less than
the risk management range for both unrestricted use and industrial use; however, the HI is greater than 1
for unrestricted use and there are potential impacts to surface water quality from soil. Non-VOC2 will be
protective of human health by preventing unrestricted use and includes ECs that will be protective of surface
water quality. The ICs and ECs require that if existing surface covers on the site are removed or remodeled,
sampling must be done, as surface cover must be maintained, or other soil/sediment ECs implemented, as
warranted as long as levels protective of surface water quality as shown in Table 2-4 are exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
240
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
LEGEND
HAND AUGER
(J) SURFACE SCRAP BSE DIM EN T SAMPLE
• SHALLOW BORING (0-15 FT BGS)
(§) STORM DRAIN
0 TRANSFORMER
——- FENCELINE
ROADS
I |SA040
1C BOUNDARY
BUILDINGS
Notes;
Small Volume Sites boring locations are shown in bold
The analytical data for borings shown in gray can be
found in the OU A RICS (Jacobs. 2001).
FFILESV3I FSM5A 040
VICINITY MAP
L L
\r r
\ 3l
XJL
L. J
SA 040
Figure D-49 SA 040 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
CH2MHILL
241
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lot Number
| | FOSET #2 Action Site
Roads
IC Compliance Boundary
Boundary
Lot Line
Figure D-50 SA 040 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento, CA
242
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 043: This 2.91 acre site is the former location of Building 236 and four storage sheds, and the current
location of Building 239 (aircraft maintenance hangar). A concrete-asphalt-paved area surrounds Building
239 and extends approximately 410 feet south of the building. The site includes sumps, a drainage trench,
and a hazardous waste storage area. Building 239 contained a sump, a drain, and an approximately 180-
foot drainage trench. The trench is not connected to the IWL or to the sanitary sewer. The final discharge
location of the drainage is most likely an outdoor sump located about 150 feet southwest of Building 239.
Waste solvent was poured into a 33-gallon hazardous storage container that was serviced by a contractor.
A transformer is located at the southwest corner of Building 239. All four storage sheds were demolished
and removed by 1988, and no information concerning their contents or function is available. No
information about the use of former Building 236 is available. In 2002, the drain trench in Building 239
was abandoned-in-place by grouting with concrete. Activities associated with aircraft maintenance,
hazardous materials and/or waste storage, possible leaks in waste oil/fuel bowser, and discharges/leaks from
outdoor sumps may have impacted surface and/or subsurface soil.
Selected Remedies: Alternatives VOC2 (ICs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; metals in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 2 * 10~5 (from naphthalene, TCE, and methylene
chloride), which is within the risk management range. SSG risk for industrial use is 1 x 10~6 (from
naphthalene), which is at the low end of the risk management range. The HI is less than 1, for both the
unrestricted use scenario and the industrial use scenario. Although risk for both unrestricted and
industrial use is within the risk management range, SSG samples were collected from only six locations,
which is not sufficient to characterize such a large site (2.91 acres). The COCs identified in SSG are
naphthalene, methylene chloride, and PCE.
Soil: Soil risk for unrestricted use is 8 x 10~5 (from arsenic) and for industrial use is 6 x 10~6 (from arsenic),
both of which are within the risk management range. The HI is 7 (from cobalt, zinc, cadmium, and arsenic)
for the unrestricted use scenario and less than 1 for the industrial use scenario. The COCs identified in soil
are cadmium, cobalt, and zinc. Arsenic is the primary driver of the carcinogenic risk, while cobalt is the
primary driver for the non-carcinogenic HI. Although arsenic concentrations (by Method SW6020) exceed
background levels for shallow soils, they are within the background data set for subsurface soils. Excluding
arsenic, the carcinogenic risks for both scenarios are less than the risk management range, but the HI
remains elevated under the unrestricted scenario.
There are potential impacts to groundwater quality from arsenic; however, arsenic concentrations are within
the background data set. Soil data do not indicate potential impacts to surface water; however, only one
surface soil sample was collected.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 7 * 10~6 and may be higher when exposure to all pathways,
including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for SA 043 is commercial/industrial.
VOC2 was selected to prevent unrestricted use due to uncertainty in the characterization of SSG. VOC2
was selected over VOC3 because VOC2 is sufficiently protective considering the relatively low risks for
industrial use and the limited extent of contamination and is also more cost effective than VOC3.
Non-VOC2 was selected to prevent unrestricted use (the HI for unrestricted use is greater than 1). Non-
VOC2 was selected because NFA would not be protective of human health. In addition, unrestricted use
would still not be possible due to SSG. Non-VOC2 will protect human health by prohibiting unrestricted
use.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUC) prohibiting
residential and other sensitive uses.
243
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 108B
PRL B-003.
PRLS-01?
SA 108C^
V
LEGEND
• SHALLOW BORING {0-15 FT BGS)
@ STORM DRAIN
H TRANSFORMER
< < SURFACE RUNOFF FLOW DIRECTION
ROADS
| | SA 043
FOLLOW-ON STRATEGIC SITES
BUILDINGS
VICINITY MAP
'Ojj
—, y'-'
£ SA043
TO
I
Figure D-50 SA 043 Site Features
Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, C/l
-CH2MHILL
244
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
r J 202
SA 043
Legend
200 Lot Number
[ | FOSET #2 Action Site
Roads
Lot Line
IC Compliance Boundary
100 Foot VOCs Compliance Buffi
Boundary
Figure D-51 SA 043 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, G4
Sacramento, CA
245
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 044: This site consists of Building 240, which supported a former aircraft nose dock from 1957 to 1973
and an x-ray facility for aircraft components from 1973 until at least 1990. X-ray film developing and
silver recovery were performed inside Building 240. A 300-gallon sump on the north side of the building
was used to collect filtered wastewater from these operations. Wastewater was later pumped into a 1,000-
gallon bowser (mobile fuel tanker) that was emptied weekly at the on-base Industrial Waste Treatment
Plant. Hazardous materials used or stored at the site included aircraft fuels, hydraulic fluids, metals, acids,
bases, solvents, oils, grease, and waste absorbent. Abandoned fuel distribution lines associated with the
adjacent SA 108 are located east of Building 240.
Selected Remedy: Alternative VOC3 (ICs/ECs)
Contaminants Addressed: VOCs in SSG
Shallow Soil Gas: There is limited older SSG data available for the site. The 1996 samples were
analyzed using TO 14, but a sample was only collected at 21.3 feet bgs (no SSG samples were collected
from within 15 feet bgs) and the 1999 samples were analyzed using M18MS. Risk values are not
available (they were not calculated because no VOCs were detected in the samples collected, but
detection limits were elevated). Based on the older data, TCE was identified as a SSG COC.
An interim SSG data gap investigation was completed in 2017 to verify the CSM and supporting
information within the Site boundaries and included the collection of two SSG samples at 7 feet bgs.
Benzene, carbon tetrachloride, chloroform, cis-l,2-DCE, 1,1-DCA, ethylbenzene, PCE, and TCE were
detected in the 2017 samples, and the TCE concentration in one sample (SA44-SG-01-7.0) and its
duplicate was above the IC compliance level. These results confirm the identification of TCE as a SSG
COC.
Soil: Soil risk for unrestricted use is 2 x 10~9 and for industrial use is 3 x 10~10, both of which are less than
the risk management range. The HI is 7 (from thallium) for unrestricted use and is less than 1 for industrial
use. Excluding thallium, the HI is less than 1 for unrestricted use. Results for thallium were flagged by the
laboratory as "estimated" amounts and do not increase in concentration with depth, indicating the
concentrations of thallium in soil are representative of natural variation in background levels. The thallium
concentration was detected with Method SW6010, which is considered to be unreliable at the reported
concentrations.
An interim soil investigation for arsenic and thallium was completed in 2017 that included the collection
of two samples (one surface soil and one subsurface soil) and analysis using Method SW6020. Arsenic and
thallium were detected in both samples, but all arsenic detections were below background and all thallium
detections were below cleanup levels. Therefore, arsenic and thallium were not identified as soil COCs.
There are potential impacts to groundwater quality from thallium and arsenic based on older data, but these
data were obtained with Method SW6010 and are considered unreliable at the reported concentrations. Soil
data do not indicate potential impacts to surface water. These findings were confirmed by the interim soil
investigation.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil is 3 x 10~10 and may be higher when exposure to all pathways,
including groundwater and SSG, are considered.
Rationale for Selected Remedy: The expected future land use for SA 044 is commercial/industrial. VOC3
will prevent unrestricted use. The need for VOC3 is confirmed by the findings of the interim SSG data gap
investigation, where TCE was detected above the IC compliance level. VOC3 was selected over VOC2
because it provides protection for industrial users given the elevated TCE concentrations detected during
the interim SSG data gap investigation and the limited number of sampling locations. The long-term
reliability and permanence of VOC3 is increased relative to VOC2 with the addition of ECs, which will
control migration of soil gas into indoor air. ICs established by VOC3 will restrict the use of the site and
246
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
require the installation of ECs in any future buildings or during significant remodeling of existing buildings
to mitigate the potential for VOCs in SSG from migrating into buildings and impacting occupants via the
vapor inhalation pathway. The parcels and lots affected by the 100-foot IC compliance buffer for VOC3
are Parcels B1 and Bid, Lots 1C, 79A, 79B, 80, and 216. Because portions of the IC compliance buffer
extend beyond the FOSET #2 boundary, soil vapor sampling along the site boundary may be conducted to
reduce or modify the extent of the IC compliance buffer zone.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
247
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
BOWSER
MW-573 —-0-
MW-574
SA44PR004
.SA44SB001
SA44PR003 . * / SA44SB002
v ^ «
SUVSR UNIT
I
SA44SB005
SA T08B
•i
¦ SA44SB004
SA 044
u
LEGEND
GROUNDWATER MONITORING WELL
A SOIL GAS BORING
# SHALLOW BORING {D-15 FT BGS)
ROADS
|SA044
FOSS SfTES
BUILDINGS
VICINITY MAP
-W
SA 044
Figure D-52 SA 044 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
CH2MHILL
248
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend Figure D-53 SA 044 IC Compliance
200 Lot Number IC Compliance Boundary Boundary Map
foset #2 Adion Site 100 Foot vocsCompliance Buffe FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
Roads | | Boundary
Sacramento, CA
Lot Line
249
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 047: This 7,600-square foot site consists of two former wash racks housed inside Buildings 254 and
257 and a hazardous materials storage area. The wash rack in Building 254 was built circa 1940 and was
demolished in 1986. The wash rack in Building 257 was built in 1986 near the east side of Building 251
and the former location of the wash rack in Building 254. At each wash rack, wastewater flowed into
drains, which were reportedly connected to the IWL. This site also included a 1,000-gallon bowser tank
used for storage of waste motor and hydraulic oil. SA 047 was within the radius of the influence of EW-
326 and EW-367 from the IC 23 SVE system.
Selected Remedies: Alternatives VOC2 (ICs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; metals in soil.
Shallow Soil Gas: SSG risk for unrestricted use is 1 x 10~5 (from chloroform, PCE, TCE, benzene,
ethylbenzene, and naphthalene), which is within the risk management range. SSG risk for industrial use is
7 x 10"7, which is below the risk management range. The HI is less than 1 for both scenarios. There is
uncertainty regarding SSG characterization. Although three SSG samples were collected at two locations,
only one of these samples was collected within the site boundaries. The SSG COCs are chloroform,
naphthalene, and PCE.
Soil: Soil risk for unrestricted use is 1 x 10"4 (from arsenic), which is greater than the risk management
range. Soil risk for industrial use is 7 x 10"6, which is within the risk management range. The HI is 5 (from
cobalt, arsenic, vanadium, and cadmium) for unrestricted use and less than 1 for industrial use. Arsenic
was detected by Method SW6010, which is considered unreliable for this metal at the reported
concentrations. Arsenic was not detected greater than background in the sample analyzed by Method
SW7060. Excluding arsenic, soil risk is less than the risk management range for both unrestricted and
industrial use; however, the HI is still greater than 1 due to cadmium and cobalt. Lead concentrations (150
mg/kg) exceed the cleanup level for protection of human health.
Soil data do not indicate potential impacts to groundwater quality. There are potential impacts to surface
water quality from arsenic, cadmium, and lead. Arsenic data were obtained with Method SW6010 and are
considered unreliable at the reported concentrations.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 7.7 x 10~6 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for SA 047 is commercial/industrial. The
preferred alternatives are VOC2 to prevent unrestricted use (due to uncertainty in characterization of SSG).
VOC2 was selected over NFA because NFA would not be protective given the uncertainty regarding SSG
characterization. Alternative VOC2 will be protective because unrestricted use will be prohibited.
Non-VOC2 to prevent unrestricted use (the HI for unrestricted use is greater than 1) and to address potential
impacts to surface water quality using ECs. Non-VOC2 was selected over Non-VOC4a because it is
protective of human health and includes ECs that will be protective of surface water quality, will not disrupt
current site use, and is more cost effective than Alternate Non-VOC4a. The ICs and ECs require that if
existing surface covers on the site are removed or remodeled, sampling must be done, as surface cover must
be maintained, or other soil/sediment ECs implemented, as warranted as long as levels protective of surface
water quality as shown in Table 2-4 are exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
250
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
LEGEND
A SOIL GAS BORING
0 HAND AUGER
O MID TO DEEP BORING (>15 FT BGS)
MANHOLE
0 FLOOR DRAIN
INDUSTRIAL WASTE LINES
ROADS
BUILDINGS
~ SA047
IC BOUNDARY
Notes:
Small Volume Sites boring locations are shown in bold.
The analytical datB for borings shewn in ti. . can be
found In the OU A RICS (Jacobs. 2001).
SA 047
Figure D-54 SA 047 Site Features
Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
CH2MHILL
251
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lot Number
| I FOSET n Action Site
Roads
IC Compliance Boundary
Boundary
Lot Line
Figure D-55 SA 047 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
Howard St
252
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 048: This 20,000-square foot site consists of Building 264 (which was used for storage of building and
ground maintenance materials) and a former 375-gallon diesel UST that was used as backup fuel source for
the generator on the west side of the building. In 1996, UST 264 was granted closure status by the Central
Valley Water Board. SA 048 was partially within the former radius of influence of the IC 25 SVE system.
Small quantities of solvents, paints, stains, resins, and glues were stored in hazmat cabinets along the south
wall of Building 264.
Selected Remedy: Alternative VOC2 (ICs)
Contaminants Addressed: VOCs in SSG
Shallow Soil Gas: SSG risk for unrestricted use is 3 * 10"5 (from chloroform and naphthalene) and for
industrial use is 2 x 10"6 (from chloroform and naphthalene), both of which are within the risk
management range. The HI is less than 1 for both the unrestricted use scenario and the industrial use
scenario. Although risk for both unrestricted and industrial use is within the risk management range, SSG
samples were collected from only three locations, which is not sufficient to characterize such a large site
(20,000 square feet). Chloroform and naphthalene were identified as COCs in SSG due to limited
exceedances in SSG samples beneath Building 264.
Soil: Soil risk for unrestricted use is 2 x 10"10 and for industrial use is 9 x 1011, both of which are below
the risk management range. The HI is less than 1 for both the unrestricted use scenario and the industrial
use scenario. No COCs have been identified for soil at SA 048.
Soil data do not indicate potential impacts to groundwater or surface water quality.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 2 / 10~6 and may be higher when exposure to all pathways,
including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for SA 048 is commercial/industrial. VOC2
was selected to prevent unrestricted use (due to uncertainty in characterization of SSG). VOC2 was selected
over VOC3 because VOC2 is sufficiently protective considering the relatively low risks for industrial use
and the limited extent of contamination. NFA would not be protective of human health given the
uncertainty regarding SSG characterization.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
253
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
L
k 050
FORMERLOCATION
OFGENEftATOR
tl-
ROU.-UP DOOR
SA 048
5A48SB01
0 ^ SA48SB004
FORMER LOCATION
OFUST
SA48SB03
^-ROLL-UP DOOR
SA 098 \ STOWAGE^
CABINET 5>
LEGEND
A SOIL GAS BORING
O MID TO DEEP BORING (>15 FT BGS)
[7] TRANSFORMER
ROADS
BUILDINGS
~ SA 048
IC BOUNDARY
VICINITY MAP
pTV-
SA 048
Figure D-56 SA 048 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento, CA
CH2MHILL
254
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Howard St
Legend Figure D-57 SA 048 IC Compliance
200 Lot Number IC Compliance Boundary Boundary Map
FOSET #2 Action site | | Boundary FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
Roads — Lot Line
255
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 053: This site approximately 0.83 acres and is the location of Building 310, which contained an
equipment repair area and special vehicle maintenance facility, a hazardous waste staging area, a washrack,
a storage shed, and a bowser tank. The washrack was used to wash maintenance equipment, and the wash
water was collected in a centrally located drain. It is unknown if the drain connected to the IWL or the
sanitary sewer. Petroleum-based wastes were stored in a 750-gallon bowser tank that was emptied every 4
to 6 months. According to Base personnel, the bowser tank was in a gravel area east of Building 310;
however, the exact location of the tank is unknown. A discolored area is in the southern portion of the site
where waste oil may have been stored. Leaks from the storage shed and bowser tank, and subsurface leaks
from the washrack area and associated piping may have impacted the surface and subsurface soil. SA 053
was within the former radius of influence of the IC 27 SVE system.
Selected Remedy: Alternative VOC3 (ICs/ECs)
Contaminants Addressed: VOCs in SSG
Shallow Soil Gas: SSG risk for unrestricted use is 1 x 10~4 (from TCE, PCE, chloroform, and
hexachlorobutadiene), which is at the high end of the risk management range. SSG risk for industrial use
is 8 x 10 6 (from TCE, PCE, chloroform, and hexachlorobutadiene), which is within the risk management
range. The HI is less than 1 for both the unrestricted use scenario and the industrial use scenario.
However, no SSG samples were collected beneath the washrack or the hazardous waste storage area,
which results in some uncertainty with regard to SSG characterization. The COCs identified in SSG are
benzene, carbon tetrachloride, chloroform, PCE, TCE, hexachlorobutadiene, and naphthalene.
Soil: Soil risk for unrestricted use is 5 x 10~5 (from arsenic) and for industrial use is 3 x 10~6 (from arsenic),
both of which are within the risk management range. The HI is 5 (from thallium and arsenic) for the
unrestricted use scenario and less than 1 for the industrial use scenario. Arsenic and thallium are the risk
drivers in soil at SA 053, but arsenic was detected below background and both metals were detected using
an unreliable method (SW6010). When arsenic and thallium are excluded, soil risks are below the
unrestricted risk management range. No COCs have been identified in soil at SA 053.
There are potential impacts to groundwater quality from arsenic and thallium and to surface water quality
from arsenic, but data for these metals were obtained with Method SW6010 and are considered unreliable.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.1 x 10~5 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for SA 053 is commercial/industrial. VOC3
was selected to prevent unrestricted use (SSG risk for unrestricted use is 1 x 10~4 and there is uncertainty
because no SSG samples were collected beneath the washrack and hazardous waste storage area). VOC3
was selected over VOC2 because it provides protection for industrial users given the TCE exceedance. The
long-term reliability and permanence of VOC3 is increased relative to VOC2 with the addition of ECs,
which will control migration of soil gas into indoor air. ICs established by VOC3 will restrict the use of
the site and require the installation of ECs in any future buildings or during significant remodeling of
existing buildings to mitigate the potential for VOCs in SSG from migrating into buildings and impacting
occupants via the vapor inhalation pathway. The parcels and lots affected by the 100-foot IC compliance
buffer for VOC3 are Parcels A4c and C9, Lots 85B, 85C, 110, 111, and 112.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
256
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
IC27SB0G4C
SA53HP0Q1
SA53PR0Q|
r-1 a
.ASPHALT
xSA53PRnQ3
J A53SB002
IC27SBQ14C
IC27SB003C
• EW-376
W-430
IC27SB015C
^ IC27SB0Q5U
/
SA53SB01
SA53SB003
[IM7SB004U
LEGEND
^ SOIL VAPOR MONITORING WELL
A SOIL GAS BORING
CD SURFACE SCRAPE/SEDIMENT SAMPLE
• SHALLOW BORING (0-15 FT BGS)
O MID TO DEEP BORING {>15 FT BGS)
© FLOOR DRAIN
E TRANSFORMER
-INDUSTRIALW^STE LINES
ROADS
BUILDINGS
~ SAQ53
IC BOUNDARY
Notes:
Small Volume Sites boring locations are shown in bold
The analytical data for borings shown in 1 can be
found in tbeOUARICS (Jacobs. 2001).
Figure D-58 SA 053 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
—' CA
— — CH2MHILL
VICINITY
SA 053
IC27SB011C
SA53HP002
IC27SB001C
f PZ-344
/ PZ-345
/ PZ-346
,SA533G03—
IC27SB003U
IC27SBD07U
MAINTENANCE
ARE/1.
HAZARDOUS
WASTE
STAGING AREA
SA 053
vv®-$n
rack
IC2/SB001L
C275B013C
PZ-335 N
PZ-336 - g.
PZ 337 ^
V ilC27Se00^'U
ASPHALT
IC27SB009C
PZ-340
STORAGE SHED
(1943 1958)
IC27SB010C
DISCOLORED AREA
PZ-341
257
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Howai i St
Legend Figure D-59 SA 053 IC Compliance Boundary
200 Lot Number IC Compliance Map
FOSET #2 Group 2 Action Sites Record of Decision
g 1 i-us>l i wc ijroup a Action sues Kecora or uecision
n ry I J FOSET #2 Act poimer McClellan Air Force Base, Sacramento, CA
100 Foot VOCs Compliance Buffer Lot Line
Sacramento, CA
Roads
258
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 058: This 17,500-square foot site consists of former Building 334 (wet chemistry, x-ray diffraction,
and radiological laboratories), which was built sometime between 1938 and 1942. The building included
floor drains connected to the sanitary sewer lines and a suspected AST at the southern end of the building.
Spent laboratory samples, including acids, bases, and small quantities of chloroform, were disposed of into
the sanitary sewer system. A transformer was located outside the southwest corner of Building 334.
Building 334 was demolished in 1993, and only the foundation remains. Releases from disposal or spills
of material used in labs and leaks from a suspected AST and transformer may have impacted the surface
soil. Leaks from a sanitary sewer may have impacted the subsurface soil. SA 058 was partially under the
influence of the IC 27 SVE system.
Selected Remedy: Alternative VOC3 (ICs/ECs)
Contaminants Addressed: VOCs in SSG
Shallow Soil Gas: SSG risk for unrestricted use is 2 * 10"3 (from carbon tetrachloride and chloroform),
which is greater than the risk management range. SSG risk for industrial use is 1 x 10"4 (from carbon
tetrachloride and chloroform), which is at the high end of the risk management range. The HI is 6 (from
carbon tetrachloride and chloroform) for the unrestricted use scenario and less than 1 for the industrial use
scenario. Although the risk for industrial use is within the risk management range, it is at the very upper
end and ECs are needed to mitigate SSG for industrial users. The COCs identified in SSG are benzene,
chloroform, carbon tetrachloride, naphthalene, and PCE.
Soil: Soil risk for unrestricted use is 5 x 10"5 (from arsenic) and for industrial use is 3 x 10"6 (from arsenic),
which are both within the risk management range. The HI is less than 1 for both the unrestricted use
scenario and the industrial use scenario. Arsenic is the main driver of soil risk, but soil concentrations are
within the range of natural background. Excluding arsenic, soil risks are below the risk management range
for unrestricted use. No COCs have been identified in soil at SA 058.
There are potential impacts to groundwater quality from arsenic, but arsenic data are below background.
There are potential impacts to surface water quality from PCBs. However, the reported concentrations do
not exceed the protection of surface water cleanup level (0.17 mg/kg).
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.03 * 10~4 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for SA 058 is commercial/industrial. VOC3
was selected to prevent unrestricted use (SSG risk for unrestricted use is greater than the risk management
range and the HI for unrestricted use is greater than 1) and to require ECs to mitigate SSG for industrial
users (SSG risk for industrial use is 1 x 10"4 and multiple COCs were detected above IC compliance levels).
VOC3 was selected over VOC2 because it is more protective to human health given the risk at the high end
of the risk management range for industrial use and the number of VOCs above IC compliance levels. ICs
established by VOC3 will restrict the use of the site and require the installation of ECs in any future
buildings or during significant remodeling of existing buildings to mitigate the potential for VOCs in SSG
from migrating into buildings and impacting occupants via the vapor inhalation pathway. The parcels and
lots affected by the 100-foot IC compliance buffer for VOC3 are Parcels A4c and C9, Lots 85C, 90B, 91,
94, 111,112, and 113A. Because portions of the IC compliance buffer extend beyond the MBP property
boundary, soil vapor sampling along the site boundary may be conducted to reduce or modify the extent of
the IC compliance buffer zone.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
259
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA58SB015
SA58SB01
IC27SBQ06C
OLD EQUIPMENT PAD
HIGH VOLTAGE BOX
FORMER ASTs
FORMER UST
IC27SB007C
SASBSBOISTV^.
ylC27SB020C
/ / SA58SB02Q
IC27SBQ17C
SA58SB018
FORMERAST PAD
IC27SB023U
IC27SB019C
CWKAREA
ON AERIAL
PHOTO
SA58HA001
IC27SB021U
SHALLOW ASPHALT
DRANAGE
(FLOWS SOUTH)
SA 039
LEGEND
A SOIL GAS BORING
® HAND AUGER
• SHALLOW BORING (0-15 FT BGS)
O MID TO DEEP BORING (>15 FT BGS)
© FLOOR DRAIN
© STORM DRAIN
~ TRANSFORMER
ROADS
BUILDINGS
~ SA 058
IC BOUNDARY
Notes:
The analytical data for borings shown in gray can be
found in the OU A RICS (Jacobs. 2001).
Figure D-60 SA 058 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
® Former McClellan Air Force Base, Sacramento,
CA
... v t., CH2MI I I
VICINITY
SA 058
260
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Hafwa rd St
Le3end Figure D-61 SA 058 IC Compliance
200 Lot Number IC Compliance Boundary Boundary Map
| FOSET #2 .action Site Boundary FOSET #2 Group 2 Action Sites Record of
" """ Decision
100 Foot VOCs Compliance Buffer - - Lot Line Former McClejlan Air Force Base Sacramento,
Roads CA
261
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 059: This 9,000-square foot site consists of Building 338 (which contained classrooms, offices, and a
500-gallon diesel UST) and former Building 91 (Base Well 8, which consisted of a 3,000-gallon AST, 500-
gallon AST, 200-gallon gasoline UST, and a sump). A railroad spur ran along the east side of Building
338. The Spur was removed prior to 1971, and the entire area is currently covered with asphalt. The USTs
were removed in 1988 and received closure from the Central Valley Water Board in 1995. An area of
discolored soil had been identified in aerial photographs between the railroad tracks; it is no longer present.
SA 059 was partially within the former radius of influence of the IC 27 SVE system.
Selected Remedies: Alternatives VOC2 (ICs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; PAHs in soil
Shallow Soil Gas: SSG risks are 6 * 10~6 (from naphthalene, hexachlorobutadiene, chloroform,
chloromethane, benzene, ethylbenzene, PCE, 1,4-DCB, and TCE), which is at the low end of the risk
management range. SSG risk for industrial use is 4 x 10"7 which is below the risk management range.
The HI is less than 1 for both the unrestricted use scenario and the industrial use scenario. Although the
risk for unrestricted use is within the risk management range, there is uncertainty remaining because SSG
samples were only collected from two locations in the southern portion of SA 059. The COCs identified
in SSG are hexachlorobutadiene, benzene, and naphthalene.
Soil: Soil risk for unrestricted use is 4 x 10"6 (from benzo(a)anthracene, benzo(a)pyrene, and
benzo(b)fluoranthene), which is at the low end of the risk management range. Soil risk for industrial use
is 5 x 10 7 which is below the risk management range. The HI is 1 (from aluminum and vanadium) for the
unrestricted use scenario and less than 1 for the industrial use scenario. The COCs identified in soil are
benzo(a)anthracene, benzo(a)pyrene, and benzo(b)fluoranthene.
There are potential impacts to groundwater from arsenic. There are potential impacts to surface water
from arsenic, TPH-D, and chrysene. Arsenic was detected using Method SW6010, which is considered
unreliable for this metal.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 9 / 10"7 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for SA 059 is commercial/industrial.
VOC2 was selected to prevent unrestricted use (due to uncertainty in characterization of SSG). VOC2 was
selected over NFA because there is uncertainty regarding SSG characterization and VOC2 will effectively
prevent unrestricted use.
Non-VOC2 was selected to prevent unrestricted use and address potential impacts to surface water quality
using ECs. Non-VOC2 was selected over Non-VOC4b because Non-VOC2 is protective of human health
and includes ECs that are protective of surface water quality, will not disrupt current site use, and is more
cost effective than Non-VOC4b. In addition, unrestricted use will not be possible due to restrictions
required to address SSG. The ICs and ECs require that if existing surface covers on the site are removed
or remodeled, sampling must be done, as surface cover must be maintained, or other soil/sediment ECs
implemented, as warranted as long as levels protective of surface water quality as shown in Table 2-4 are
exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
262
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
LEGEND
A SOIL GAS BORING
S HANDAUGER
• SHALLOW BORING (0-15 FT BGS)
O MID TO DEEP BORING (>15 FT BGS)
= DOORS
-+— FORMER RAILROAD TRACK
ROADS
BUILDINGS
I ISA 059
IC BOUNDARY
Notes:
The analytical data for borings shown in gray can be
found in the OU A RICS (Jacobs, 2001).
SA 098
SA 039
Figure D-62 SA 059 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
so Former McClellan Air Force Base, Sacramento,
CA
QH2MHILL
SA 053
SA 059
SA59SB003
SHALLOW ASPHALT
DRAINAGE (FLOWS SOUTH)
SA59SB02
SA59HA001
SA59SB01
SA59PR002
263
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend Figure D-63 SA 059 IC Compliance
200 Lot Number IC Compliance Boundary Boundary Map
FOSET #2 Action Site | | Boundary FOSET #2 Group 2 Action Sites Record of Decision
1 Former McClellan Air Force Base, Sacramento, CA
Roads Lot Line
264
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 067: This site consists of the 73,000-square foot Building 360 (used for F-15 and A-10 aircraft
maintenance) and the area south of the building, which was used for hazardous waste storage. Areas west
of the building include a former wash rack, a former 400-gallon hydraulic fluid AST, a former 1,000-gallon
steel bowser tank, and a hazardous materials storage area. A catch basin/vault on the southern end of the
washrack collected runoff. The catch basin/vault was located in 1985 and was determined to be abandoned,
but its exact location was never documented and is currently unknown. The washrack was located on badly
cracked concrete and asphalt and was used to clean and remove paint from aircraft. The AST was located
in a bermed area that had repeatedly filled up with hydraulic fluid over the last 25 years; and that light
solvents and heavy detergents were used to remove paint and to wash down aircraft in the former washrack
area west of Building 360. The removal date of the AST is unknown and the bowser tank was reported to
have been removed following the environmental baseline survey in 1999. The washrack room in the
southeastern corner of Building 360 was used to steam clean aircraft parts. A sump collected wash water
from the steam cleaning activities performed in the southeastern washrack room. The sump discharged
wash water into the IWL system. Operations inside Building 360 ceased in April 1999. SA 067 was within
the former radius of influence of the IC 29 SVE system.
Selected Remedy: Alternative VOC3 (ICs/ECs)
Contaminants Addressed: VOCs in SSG
Shallow Soil Gas: SSG risk for unrestricted use is 4 * 10~6 (from benzene, ethylbenzene, naphthalene,
PCE, TCE, and chloroform), which is at the low end of the risk management range. SSG risk for
industrial use is 2 x 10"7, which is less than the risk management range. The HI is less than 1 for both use
scenarios. However, there is uncertainty regarding SSG characterization. This site is about 147,650
square feet (approx. 3.39 acres) with a 73,000-square foot building that was used for aircraft maintenance,
but no SSG samples were collected beneath the building and only five SSG sample locations were located
within the site boundaries.
Soil: Soil risk for unrestricted use is 4 x 10~5 (from arsenic) and for industrial use is 3 x 10~6, both of
which are within the risk management range. The HI is 4 (from cobalt and arsenic) for unrestricted use
and less than 1 for industrial use. Soil risks (excluding arsenic and cobalt) are within the risk
management range for unrestricted use and the HI is less than 1 for unrestricted use. Arsenic was
detected using Method SW7060 background. Cobalt was detected above the unrestricted use screening
level in one sample.
There are potential impacts to groundwater quality from thallium and arsenic, but data were obtained with
Method SW6010 and are considered unreliable at the reported concentrations. There are also potential
impacts to groundwater quality from TPH-D; however, while concentrations of TPH-D exceed screening
levels, concentrations do not exceed the likely protection of groundwater quality level (3,900 mg/kg).
Soil data do not indicate potential impacts to surface water quality.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 3.2 / 10"6 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for SA 067 is commercial/industrial. VOC3
was selected to prevent unrestricted use and to require ECs to mitigate SSG for industrial users (due to
uncertainty in characterization of SSG). ICs established by VOC3 will restrict the use of the site and require
the installation of ECs in any future buildings or during significant remodeling of existing buildings to
mitigate the potential for VOCs in SSG from migrating into buildings and impacting occupants via the
vapor inhalation pathway. The parcels and lots affected by the 100-foot IC compliance buffer for VOC3
are Parcels A4d, Bid, and C10, Lots 82B, 97, 98, 100, 101, 102, 103, 104, and 203. Because portions of
the IC compliance buffer extend beyond the FOSET #2 boundary, soil vapor sampling along the site
boundary may be conducted to reduce or modify the extent of the IC compliance buffer zone.
265
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
266
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
P2-I59
SA 0?A P^boeze
.;PF?L ^.0020.
-\///
s
- 1 y&Sa
LEGEND
¦ DUAL PHASE 'MPOR EXTRACTION WELL 21 TRANSFORMER
¦ SOU VAPOR EXTRACTION WELl INDUSTRIAL WASTE LINES
SOU VAPOR MON»TC4?INGWELl „
A SOIL GAS GORtMG '
C SURFACE SCRAPBSEOIMENT SAMPLE I |SAC6T
• SHALLOW BORING (0-1S FT BGS) »C BOUNDARY
C MID TO DEEP BORING (>15 FT BGS) BUILDINGS
V MANHOLE
~ LIFT STATION
tJ SUMP
The analyOcai data for wxlngs shown in can be
found in II* OU A RJCS (Jacct* H»t)
Figure D-64 SA 067 Site Features Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
• Transformer is located outside {wilding, fcul u
267
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Peacekt
Arnold Ave
43th St
Legend
200 Lot Number
1 | FOSET #2 Action Site
100 Foot VOCs Compliance Buffer
Roads
IC Compliance Boundary
Boundary
Lot Line
Figure D-65 SA 067 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
268
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 068: This site is approximately 0.90 acres and consists of Building 365 (aircraft hangar), where aircraft
maintenance and minor paint stripping activities took place dating back to 1943. TCE was known to be
sprayed on parts and left to air-dry. TCE spills on the floor were not uncommon. A hydraulic manifold
system was present in the building and consisted of hydraulic fluid lines that ran beneath the building. A
hazardous material storage area used to store paint was located in the north end of the building, and 55-
gallon waste drums (potentially containing Freon or hydraulic oil) were stored in the southwest portion of
the building. Two additional hazardous materials storage areas were located along the west edge of the
building where chemicals for maintenance activities and waste from building activities were stored. Trench
drains ran along each side of the hangar. Cracks in the concrete foundation were noted throughout the
building, and an employee noted that a floor drain in the west-central portion of the building occasionally
backed up and overflowed. SA 068 is partially within the former radius of influence of the IC 29 SVE
system.
Selected Remedy: Alternative VOC2 (ICs)
Contaminants Addressed: VOCs in SSG
Shallow Soil Gas: SSG risk for unrestricted use is 1 x 10~6 (from benzene, ethylbenzene 1,4-DCB, PCE,
TCE, carbon tetrachloride, chloroform, and naphthalene), which is at the low end of the risk management
range. SSG risk for industrial use is 9 x 10~8, which is less than the risk management range. The HI is
less than 1 for both use scenarios. However, there is uncertainty regarding SSG characterization, because
only two SSG samples were collected from a single location (PT10SB017) prior to 2017. Based on the
past SSG data, benzene, chloroform, 1,4-DCB, ethylbenzene, naphthalene, PCE, TCE, and carbon
tetrachloride were identified as SSG COCs.
An interim SSG data gap investigation was completed in 2017 to verify the CSM and supporting
information within the Site boundaries and included the collection of three SSG samples at 7 feet bgs.
Chloroform, cis-l,2-DCE, 1,4-DCB, PCE, and TCE were detected in the 2017 samples, but no VOCs
were detected at concentrations above the IC compliance levels. Therefore, no additional SSG COCs
were identified. The SSG COCs are carbon tetrachloride and TCE.
Soil: Soil risk for unrestricted use is 4 x 10"7 and for industrial use is 6 x 10~8, both of which are less than
the risk management range. The HI is 6 (from cobalt) for unrestricted use and less than 1 for industrial
use. The HI excluding cobalt is less than 1 for unrestricted use. Cobalt was detected above the
unrestricted use screening level in one sample; however, it was not detected above screening levels in
deeper samples from the same location, indicating that the detection is isolated and does not represent a
source of contamination.
An interim soil investigation for arsenic was completed in 2017 that included the collection of two
samples (one surface soil and one subsurface soil) and analysis using Method SW6020. Arsenic was
detected in both samples, but all arsenic detections were below background. Therefore, arsenic was not
identified as a soil COC.
There are potential impacts to groundwater quality from arsenic based on older data, but these data were
obtained with Method SW6010 and are considered unreliable at the reported concentrations. Arsenic
results by a more reliable method (Method SW7060) indicate concentrations are within background
levels. Soil data do not indicate potential impacts to surface water quality.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.5 x 10~7 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for SA 068 is commercial/industrial. VOC2
was selected to prevent unrestricted use (due to uncertainty in characterization of S SG). VOC2 was selected
269
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
over NFA because NFA is not protective of human health given the uncertainty regarding SSG
characterization. Alternative VOC2 will be effective by preventing unrestricted use.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
270
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRLS-
S4S0SBDO1
^ /
STORAGE.
APEAS
55 GAl LOW WASTE
5? GRACE CfiUMS
L-OWC
SA68PRD03
U0UO
IKEwen
yS OfefllM
' SA68PR001
TRENCH
, SAeeSBCC j 3AB0SG1 5
DRAIN
0 'ID 0 *
S.A68PR002
SAtffiSGM
0
<¦>
0
0
0 0 0 0O
tP
SA 068
SA685GCH
•-V \
X TRENCH
DRAIN
I-
. TRENCH
ItSfAJBNl
vK
LEGEND
~ SOIL GAS BORING
Cl) SURFACE SCRAPE/SEDIMENT SAMPLE
• SHALLOW BORING (0-15 FT BGS)
O MID TO DEEP BORING (>15 FT BGS}
0 FLOOR DRAIN
INDUSTRIAL WASTE LINES
ROADS
BUILDINGS
[ | SA 068
IC BOUNDARY
Notes.
Small Volume Sites coring locations are shown in bold
The analytical data for borings shown in n i / can be u
found in the OU A RICS (Jacobs. 2001 j.
p
"\
Figure D-66 SA 068 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento, CA
CH2MHILL
271
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lot Number
| | FOSET #2 Action Site
Roads
IC Compliance Boundary
Boundary
— Lot Line
Figure D-67 SA 068 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
272
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 071: This 1,400-square foot site includes Building 369, which is the former location of hazardous
material (southern part of building) and hazardous waste (northern part of building) storage areas that were
used from 1969 until base closure in 2001. An open area to along the west side of the building was used as
a staging area for hazardous waste from the reprographics department. An area southwest of the building
was used to containerize 55-gallon drums on pallets. Additionally, two transformers are located on the west
side of the building. Hazardous materials stored at the site included paints, oils, thinners, and film-
developing chemicals. Hazardous wastes stored along the side of the building included solvents, spent
containers, paints, solvent-contaminated rags, and chemicals found in printing and photo developing labs.
Selected Remedies: Alternatives VOC2 (ICs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; Metals and PCBs in soil
Shallow Soil Gas: SSG risk for unrestricted use is 1 x 10~5 (from chloroform, methylene chloride, PCE,
TCE, and benzene), which is within the risk management range. SSG risk for industrial use is 7 x 10"7,
which is less than the risk management range. The HI is less than 1 for both the unrestricted use scenario
and the industrial use scenario. Although the risk for unrestricted use is within the risk management
range, there is uncertainty remaining because SSG samples were only collected from a single location.
The COCs identified in SSG are benzene and chloroform.
Soil: Soil risk for unrestricted use is 2 x 10"4 (from arsenic), which is greater than the risk management
range. Soil risk for industrial use is 1 x 10~5 (from arsenic), which is within the risk management range.
The HI is 4 (from arsenic, cadmium, and vanadium) for the unrestricted use scenario and is less than 1 for
the industrial use scenario. Arsenic was detected at concentrations above screening levels using Method
SW6010, which is considered unreliable for this metal, but is not present at concentrations that represent
contamination. Arsenic concentrations are likely representative of the natural variation of background
levels. Excluding arsenic, soil risks are less than the risk management range for unrestricted use;
however, the soil HI for unrestricted use is still greater than 1 due to cadmium.
There are potential impacts to groundwater and surface water quality from arsenic, but arsenic data were
obtained with Method SW6010 and are considered unreliable. There are potential impacts to surface
water quality from PCBs, arsenic, and cadmium; however, arsenic data were obtained with Method
SW6010 and are considered unreliable. ECs are needed to maintain the surface cover because of PCBs
and cadmium.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.07 * 10~5 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for SA 071 is commercial/industrial.
VOC2 was selected to prevent unrestricted use (due to uncertainty in characterization of SSG). VOC2 was
selected over NFA because NFA is not protective of human health due to uncertainty regarding SSG
characterization. Alternative VOC2 will effectively prevent unrestricted use.
Non-VOC2 was selected to prevent unrestricted use (the HI for unrestricted use is greater than 1) and to
address potential impacts to surface water quality using ECs. Alternative Non-VOC2 was selected over
Alternative Non-VOC4b because it is protective of human health and includes ECs that will be protective
of surface water quality, would not disrupt current site use, and is more cost effective than Alternate Non-
VOC4b. The ICs and ECs require that if existing surface covers on the site are removed or remodeled,
sampling must be done, as surface cover must be maintained, or other soil/sediment ECs implemented, as
warranted as long as levels protective of surface water quality as shown in Table 2-4 are exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
273
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
HAND MJGER
! SHALLOW BORING (0-16 FT BG3)
. FLOOR DRAIN
R STORM DRAIN
) TRANSFORMER
ROADS
] BUILDINGS
I ISAtffl
IC BOUNDARY
Figure D-68 SA 071 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base,
Sacramento, CA
r.ypRO JfMCCL EL LAN
CH2MHILL
274
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Roads - Lot Line Former McClellan Air Force Base, Sacramento, CA
275
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 073: This approximately 0.32-acre site consists of former Building 385 (comprised of a hangar,
observation room, heating and cooling equipment room, and a basement containing hydraulic equipment)
and the surrounding area. Before Building 385 was constructed in 1970, this area was used to wash aircraft.
Operations in Building 385 ceased in 1999. Approximately 300 gallons of hydraulic fluid was used to
operate stress rams. A sump that discharged to Magpie Creek was reportedly located in the basement and
collected spills that may have occurred. A 25,000-gallon liquid nitrogen AST was located at the southwest
side of the building. Current site conditions are dirt and grass, some concrete and remaining curbing, and
a concrete pad with electrical switching station.
Selected Remedies: Alternatives VOC2 (ICs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; Metals, PAHs, and PCBs in soil
Shallow Soil Gas: There is insufficient SSG data available. The soil gas sample from 21-21.5 feet bgs at
SA73HP31 contained high levels of VOCs, but there were no SSG samples collected at the site prior to
2017. Risk values are not available (none were calculated because SSG samples were not collected). No
COCs have been identified.
An interim SSG data gap investigation was completed in 2017 to verify the CSM and supporting
information within the Site boundaries and included the collection of two SSG samples at 7 feet bgs
(TetraTech, 2017). Chloroform and TCE were detected in the 2017 samples, but no VOCs were detected
at concentrations above the IC compliance levels. Therefore, no SSG COCs were identified.
Soil: No soil samples were collected prior to 2017, so the risk associated with soil is uncertain and it is
unknown if contaminants with potential impacts to groundwater and surface water quality are present.
An interim soil investigation was completed in 2017 that included the collection of three surface soil and
two subsurface soil samples from three locations (TetraTech, 2017). Several metals and PAHs were
detected, but only lead and benzo(a)pyrene concentrations exceeded cleanup levels. The reporting limit
for PCBs was greater than the cleanup level, resulting in uncertainty regarding the characterization of
PBCs. Therefore, benzo(a)pyrene, lead, and PCBs have been identified as soil COCs.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is unable to be determined at this time.
Rationale for Selected Remedies: The expected future land use for SA 073 is commercial/industrial.
VOC2 was selected because the CSM of Site SA 073, along with the knowledge of the risks posed by other
sites with a similar CSM and additional sampling data, indicate that VOC2 is appropriate and will prevent
unrestricted use.
Non-VOC2 was selected because the CSM of Site SA 073, along with the knowledge of the risks posed by
other sites with a similar CSM and additional sampling data, indicate that Non-VOC2 is appropriate and
will prevent unrestricted use. The need to prevent unrestricted use was confirmed by the results of the
interim soil investigation.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
276
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
, CSS24SB024
6
LEGEND
O MID TO DEEP BORING (>15 FT BGS)
ROADS
~ SA073
VERNAL POOL
BUILDINGS
0,
SA 073
Figure D-70 SA 073 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento, CA
-CH2MHILL
277
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
] FOSET#2 Action Site | | Boundary FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
Roads Lot Line
278
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 077: This site is approximately 0.58 acres and consists of Building 411, which was used for aircraft
and automotive maintenance. In 1965, two 500- gallon oil ASTs were installed at the north corner of
Building 411 and were used until 1990. The site also included a hazardous material staging and storage
area and three self-contained solvent/degreasing sinks. Site drawings show a capped IWL drain and three
sanitary drains. Spills from the USTs at CS T-020 or hazardous material staging and storage area may have
impacted surface soil. Releases from the solvent/degreasing sinks, IWL drain, USTs at CS T-020, or fuel
distribution pipeline may have impacted the subsurface soil. SA 077 is within the former radius of influence
of the IC 37 SVE system.
Selected Remedy: Alternative VOC2 (ICs)
Contaminants Addressed: VOCs in SSG
Shallow Soil Gas: SSG risk for unrestricted use is 3 * 10~5 (from carbon tetrachloride, PCE, and
chloroform) and for industrial use is 2 x 10"6 (from carbon tetrachloride, PCE, and chloroform), both of
which are within the risk management range. The HI is less than 1 for both the unrestricted use scenario
and the industrial use scenario; however, there is some uncertainty regarding this risk characterization due
to the continued SVE system operation. The COCs identified in SSG are benzene, carbon tetrachloride,
chloroform, PCE, 1,2,4-TMB, ethylbenzene, and naphthalene.
Soil: Soil risk for unrestricted use is 5 x 10"5 (from arsenic) and for industrial use is 3 x 10"6 (from
arsenic), both of which are within the risk management range. The HI is less than 1 for both the
unrestricted use scenario and the industrial use scenario. Soil risks are below the risk management range
for unrestricted use when excluding arsenic, which is present at concentrations below background.
There are potential impacts to groundwater quality from arsenic and thallium, but data were obtained with
Method SW6010 and are considered unreliable for these metals. There are potential impacts to
groundwater quality from TPH-D and TPH-G located north and northeast of SA 077, but this area is
addressed with site SA 081. No COCs have been identified in soil at SA 077.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 5 x 10~6 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for SA 077 is commercial/industrial. VOC2
was selected to prevent unrestricted use (due to uncertainty regarding characterization of SSG). VOC2 was
selected over NFA because NFA is not protective of human health due to uncertainty regarding SSG
characterization. Alternative VOC2 will effectively prevent unrestricted use.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
279
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
'SA77PRG03,
> SA77HA01
SA77SB005
SA77SB004
V/-SA77P«002V V
/* SA77SB008
' s SA77SB003
> PL IMAGED IWl DftAW
SA77PRIIIW
SA77SB009
OSA77SB006
^xSA7 7PR00l 020
- rORMEP SOLVENT Sm .
SA81ESB 007 sfl
—- SA77SB013
SA77SB010
FORMER
CARBURETOR —.
•CLEANER TANK
SA77SB012
FORMER OL'DftUMSlgKAGfc
fc I ORMEP K»A2ARDOua
M£TER1ALV 5T/VVIN0 APFA
SA106HA10-*
SA77PR006
3A77PRQ07
N CST20HA0Q1
' ORMEjR WB.UINU SHOP'
SA77SG02
-OlVMPRSCUVeNI SIMMS
MW-382
Notes:
Small Volume Sites boring locations are shown in bold
The analytical data for borings shown in ¦, can be
found in the OU A RICS (Jacobs, 2001).
Figure D-72 SA 077 Site Features
Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento, CA
CHZMH1LL
$ SOIL VAPOR MONITORING WELL INDUSTRIAL WASTE LINES
A SOIL GAS BORING —'— RAILROADS
HAND AUGER ROADS
H
fj> SURFACE SCRAPBSEDIMENT SAMPLE BUILDINGS
• SHALLOW BORING (0-15 FT BGS)
0 MID TO DEEP BORING (>15 FT BGS) I |SA077
1 MANHOLE IC BOUNDARY
077
VJGINITY
LEGEND
280
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lot Number
| | FOSET #2 Action Site
Roads
IC Compliance Boundary
Boundary
— Lot Line
Figure D-73 SA 077 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
281
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 078: This approximately 0.66-acre site consists of Building 412, a former locomotive maintenance
facility that operated from 1946 to 1994. This area consisted of a hazardous materials storage building and
locomotive washing area, a service pit for working on locomotives, and a former 3,100-gallon diesel UST
located in the northwestern portion of the building that was removed in November 1985. IWL drains were
located in the washing area, and a hazardous material shed was located adjacent to the washing area.
Closure for the UST was granted by the Central Valley Water Board in September 1999. From 1988 to
1994, the concrete service pit collected water, which was pumped to the IWL. Before 1988, wastewater
was pumped into a 1,000-gallon bowsertank. Materials used, handled, and stored at SA 078 include fuels,
oils, solvents, and acids. Wastes were containerized and picked up by Defense Reutilization Marketing
Office for proper disposal. There was evidence of spills in the stained berm area southwest of Building
412. Building 412 is currently used as a locomotive maintenance facility by Sacramento Valley Railroad.
Selected Remedy: Alternative Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: TPH and metals in soil
Shallow Soil Gas: SSG risk for unrestricted use is 4 * 10~6 (from benzene, carbon tetrachloride,
chloroform, ethylbenzene, hexachlorobutadiene, naphthalene, PCE, and TCE), which is at the low end of
the risk management range. SSG risk for industrial use is 2 x 10"7, which is below the risk management
range. The HI is less than 1 for both the unrestricted use scenario and the industrial use scenario. The
SSG COCs are benzene, 1,4-DCB, and TCE.
Soil: Soil risk for unrestricted use is 7 x 10"5 (from arsenic) and for industrial use is 5 x 10"6 (from
arsenic), both of which are within the risk management range. The HI is less than 1 for both the
unrestricted use scenario and the industrial use scenario. Arsenic is the main driver of risk, but data
exceeding background values were detected using Method SW6010, which is considered unreliable for
arsenic. Data analyzed using Method SW7060 are below the background value for arsenic. Excluding
arsenic, soil risks are within the low end of the risk management range for unrestricted use and below the
risk management range for industrial use.
There are potential impacts to groundwater quality from arsenic and to surface water quality from arsenic,
lead, and TPH-D. Arsenic data exceeding background values were detected using Method SW6010,
which is considered unreliable for arsenic. Arsenic data analyzed using Method SW7060 are below the
background value for arsenic. Lead and TPH-D are identified as soil COCs.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 5.2 * 10~6 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for SA 078 is commercial/industrial. Non-
VOC2 was selected to prevent unrestricted use and address impacts to surface water quality using ECs.
Non-VOC2 was selected over NFA because NFA would not include ECs. The ECs associated with Non-
VOC2 will be protective of surface water quality. The ICs and ECs require that if existing surface covers
on the site are removed or remodeled, sampling must be done, as surface cover must be maintained, or other
soil/sediment ECs implemented, as warranted as long as levels protective of surface water quality as shown
in Table 2-4 are exceeded.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
282
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
DECOMMISSIONED / /
S MARIRA1 OAS I WE / f
f A /
FORMER y£»CAT ION OF, I non
rRASS^nGAl i ON VvfeTFVATER, BOWSER ,
TAWK'/CUFREWT L OgATIQN OF OW©
SA79SB016 (&HWLSG163
'TOOL 7
room/ a
SA78SB020 SA^BSBOI 8 ¦
SA78SB007
rretM£jH I IAZaPDOUo
WATER lALSTGPAfiF ¦
eiACMNG
SA7BSB004 ,
SA7BSB02 -J
SA78HA028 - -j(
SA78SB009 —y-
SA78SB0Q6 -f]
SA78SB022
SA78S8Q03 •
DfTCH- *
SA78SB008
SA78SB019r
SA78SB026 \ SERVlCFy^
SA7BSB005 /
/ FOR MER LG CAT ION OF 31 CO
—--XGAll.ONUNPERCjWOI (NT/
/ ^DJBSEL 1AWf-
1 3A78SB021 /
¦?V
SA78SB01,
locomotive;
AftEA*
5A78SB01
IVVi. DRAMS
and piheLme
CULANOLll
L OCATION
IMfFP PIT
d SA78S8DI
/f
/ reseat
v9A76sem2
SA78SB023
LEGEND
0 HAND AUGER INDUSTRIAL WASTE LINES
0 SURFACE SCRAPE/SEDIMENT SAMPLE ROADS
# SHALLOW BORING (0-15 FT BGS) n SA078
O MID TO DEEP BORING (>15 FT BGS) ^ BQUNDARY
MANHOLE
BUILDINGS
- FENCELINE
- RAILROADS
Notes:
Small Volume Sites boring locations are shown in bold.
The analytical data for bonngs shown in gr - can be
found in the OU A R1CS (Jacobs, 2001).
Figure D-74 SA 078 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
CH2MHILL
283
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA078
Legend
200 Lot Number
| | FOSET #2 Action Site
Roads
IC Compliance Boundary
Boundary
Lot Line
Figure D-75 SA 078 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base. Sacramento, CA
284
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 079: This site is approximately 0.50 acres and consists of Building 429 (former fuel-testing facility and
electronics and motor shop), which was constructed in 1951. Building 429 operated as an electronics and
motor shop from 1964 to 1985. Stoddard solvent was reportedly used to degrease parts at the electronics
shop. Building 429 had 4 solvent trench pipelines and 18 IWL floor drains. The IWL runs along the
southwestern corner of the building. Four fuel and lubricant USTs ranging from 265 gallons to 10,000
gallons were in the southeast corner of the building. These USTs were installed in the 1950s and removed
prior to April 1989. The USTs have not been granted closure. Releases from USTs, solvent supply line,
solvent drain line trenches, and IWL drains inside the building may have impacted the subsurface soil. SA
079 was within the former radius of influence of the IC 35 SVE system.
Selected Remedy: Alternative VOC3 (ICs/ECs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; metals in soil
Shallow Soil Gas: SSG risk for unrestricted use is 2 x 10~4 (from 1,4-DCB, chloroform, ethylbenzene,
naphthalene, PCE, TCE, and vinyl chloride), which is greater than the risk management range. SSG risk
for industrial use is 1 x 10~5 (from 1,4-DCB, chloroform, ethylbenzene, naphthalene, PCE, TCE, and vinyl
chloride), which is within the risk management range. The HI is 58 (from DCE, 1,2,4-TMB, and 1,3,5-
TMB) for the unrestricted use scenario and is 4 (from DCE, 1,2,4-TMB, and 1,3,5-TMB) for the industrial
use scenario. The COCs identified in SSG are chloroform, 1,4-DCB, ethylbenzene, hexachlorobutadiene,
naphthalene, PCE, TCE, 1,2,4-TMB, 1,3,5-TMB, and vinyl chloride.
Soil: Soil risk for unrestricted use is 1 x 10~4 (from arsenic), which is at the high end of the risk management
range. Soil risk for industrial use is 1 x 10~5 (from arsenic), which is within the risk management range.
The HI is 3 (from arsenic, aluminum, and 2-methylnaphthalene) for the unrestricted use scenario and less
than 1 for the industrial use scenario. Arsenic is the main driver of soil risk, but was analyzed using Method
SW6010, which is considered unreliable. Excluding arsenic, soil risks are below the risk management
range for unrestricted use and industrial use; however, cadmium was under-represented in the risk
assessment. A maximum value of 2.0 mg/kg was considered in the risk assessment, but maximum
concentration is 18 mg/kg at a depth of 10.25 feet bgs. Cadmium concentrations exceed the cleanup level
and add to the HI value (by approximately 3 for an HI of 6). The COC in soil is cadmium.
There are potential impacts to groundwater quality from arsenic and thallium, but the data for these metals
were obtained with Method SW6010 and are considered unreliable.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and S SG is 2 x 10 5 and may be higher when exposure to all pathways,
including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for SA 079 is commercial/industrial.
VOC3 was selected to prevent unrestricted use (SSG risk for unrestricted use is 2 x 10~4 and the HI for
unrestricted use is greater than 1) and to require ECs to mitigate SSG for industrial users (the HI is greater
than 1). VOC3 was selected over VOC2 because VOC2 would not be protective of industrial users given
that the HI is greater than 1 for the industrial scenario. ICs established by VOC3 will restrict the use of the
site and require the installation of ECs in any future buildings or during significant remodeling of existing
buildings to mitigate the potential for VOCs in SSG from migrating into buildings and impacting occupants
via the vapor inhalation pathway. The parcel and lots affected by the 100-foot IC compliance buffer for
VOC3 are Parcels B2 and B3, Lots 120, 123A, 123B, 123D, and 125. Soil vapor sampling along the site
boundary may be conducted to reduce or modify the extent of the IC compliance buffer zone.
Non-VOC2 was selected to prevent unrestricted use (the HI is greater than 1). Non-VOC2 was selected
over NFA because NFA would not be protective of human health since the HI is greater than 1 for the
unrestricted use scenario. Non-VOC2 meets the threshold criteria, will effectively prevent unrestricted use,
and is protective of human health.
285
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
286
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA79SB006
SA7QPR001
SA79SB0Q7
91 u vi N1
DRAIN LINE
TRENCHES
IVM- DRAINS
SA79PR003
SA/9PR0CU
SA79SB01.
SA795B03 CsJ
approximate: location
OF FORMER 265 GAL UST
APPROXIMATE LOCATION OF
FORMER 3,000 GAL UST
UST (UNKNOWN CAPACITY)
SA79SB02''
/\ /
f SA79PR005
/.pwoxiMAre low ion <>r
rciRMEB 10,000 GAL UST
PLL4ASB007
LEGEND
A SOIL GAS BORING
• SHALLOW BORING (0-15 FT BGS)
O MID TO DEEP BORING (>15 FT BBS)
© MANHOLE
D LIFT STATION
© FLOOR DRAIN
INDUSTRIAL WASTE LINES
ROADS
| | SA 079
IC BOUNDARY
BUILDINGS
079
Notes:
Small Volume Sites boring locations are shown in bold
The analytical data for borings shown in gray can be
found in the OU A RICS (Jacobs. 2001).
Figure D-76 SA 079 Site Features Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
CH2MHILL
287
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend Figure D-77 SA 079 IC Compliance
200 Lot Number IC Compliance Boundary Boundary Map
FOSET #2 Action Site I I Boundary FOSET #2 Group 2 Action Sites Record of
100 Foot VOCs Compliance Buffer — - Lot Line Decision
Former McClellan Air Force Base, Sacramento,
Roads CA
288
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 081: This site consists of a fuel distribution pipeline constructed of 3-, 4- and 6-inch-diameter black
iron pipe. The pipeline was constructed to convey aviation gas, jet fuel, and lube oil from former Tank
Farms 1, 2, 3, 6 and 8 to various buildings throughout OU A. The fuel pipeline began operations in 1956
and operated until 1992. Approximately one-quarter of the pipeline is located in an underground, concrete-
lined trench. The remaining sections of the pipeline are buried underground. Following the end of
operations, the various sections were drained, steam cleaned, and then abandoned in place. Leaks from the
fuel distribution pipeline as result of deteriorated pipes and offset joints may have impacted the subsurface
soil.
Selected Remedies: Alternatives VOC3 (ICs/ECs) and Non-VOC4a (Excavation and Disposal-Restricted
Land Use)
Contaminants Addressed: VOCs in SSG; metals and TPH in soil
Shallow Soil Gas: SSG risk for unrestricted use is 7 x 10"5 (from vinyl chloride and TCE) and for industrial
use is 5 x 10"6 (from vinyl chloride), both of which are within the risk management range. The HI is 9
(from xylenes, naphthalene, 1,2,4-TMB, and 1,3,5-TMB) for the unrestricted use scenario and less than 1
for the industrial use scenario. The COCs identified in SSG are TCE; PCE; benzene; chloroform;
ethylbenzene; naphthalene; vinyl chloride; 1,2,4-TMB; and 1,3,5-TMB.
Soil: Soil risk for unrestricted use is 1 x 10"4 (from arsenic, dioxins/furans, PAHs and naphthalene), which
is at the high end of the risk management range. Soil risk for industrial use is 9 x 10"6 (from arsenic, PAHs,
and naphthalene), which is within the risk management range. The HI is 3 (from arsenic, cadmium,
thallium, and 2-methylnaphthalene) for the unrestricted use scenario and is less than 1 for the industrial use
scenario. Arsenic and thallium results from Method SW6010 were not used in the risk summary tables
because sufficient data by non-SW6010 methods were available. Arsenic is the main driver of the soil risk
at SA 081, but it is not a COC for fuel pipelines, and it was within the range of natural background.
Excluding arsenic, soil risks are within the risk management range for unrestricted use and at the low end
of the risk management range for industrial use. Concentrations of benzo(a)anthracene, benzo(a)pyrene,
benzo(b)fluoranthene, chrysene, 2-methylnaphthalene, and naphthalene exceeded cleanup levels. The soil
COCs are benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, cadmium, chrysene, lead,
naphthalene, 2-methylnaphthalene, TPH-D, and TPH-G.
There are potential impacts to surface water quality from cadmium, lead, and TPH-D and to groundwater
quality from TPH-D, TPH-G, arsenic, and thallium, but arsenic was detected below background levels and
thallium was detected using a method that is considered unreliable.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 1.4 * 10"5 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for SA 081 is commercial/industrial.
VOC3 was selected to prevent unrestricted use (the HI for unrestricted use is greater than 1) and to require
ECs to mitigate SSG for industrial users (due to uncertainties related to characterizing the length of the
entire fuel line). VOC3 was selected over VOC2 because VOC2 is not protective of industrial users
considering the uncertainty related to characterization the length of the fuel line. ICs established by VOC3
will restrict the use of the site and require the installation of ECs in any future buildings or during significant
remodeling of existing buildings to mitigate the potential for VOCs in SSG from migrating into buildings
and impacting occupants via the vapor inhalation pathway. The parcel and lots affected by the 100-foot IC
compliance buffer for VOC3 are Parcels Blc, B2, and B3, Lots 114B, 114C, 114D, 114F, 115A, 115B,
115C, 119, 120, 121, 122A, 122B, 123A, 123C, 124, 125, 126, 127A, 204, and 205. Soil vapor sampling
along the site boundary may be conducted to reduce or modify the extent of the IC compliance buffer zone.
Non-VOC4a was selected to prevent unrestricted use and excavation to address potential impacts to
groundwater and surface water quality. The target excavation volume is 42,620 cubic yards. Due to the
289
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
complexity of the infrastructure and buildings at SA 081, it is recognized that excavation of some
contamination may not be possible and that bioventing may be necessary to address TPH contamination
with Regulatory Agency approval. This site also has Air Force retained conditions due to contamination
below 15 feet bgs. Non-VOC4a was selected over Non-VOC4b because restrictions will remain for SSG,
even if soil is unrestricted.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
290
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
gAWHAww,
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Smail v'nk»r
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
^ Arnold Ave
L'— fin'K
W'l nona Way
Legend
200 Lot Number
Boundary
Lot Line
Roads
~
Figure D-79 SA 081IC Compliance
Boundary Map
IC Compliance Boundary ^ 1
FOSET #2 Group 2 Action Sites Record of Decision
FOSET n Action Site Former McClellan Air Force Base, Sacramento, CA
100 Foot VOCs Compliance Buffer fvrmerMcCleilanAirForce Base
Sacramento. OA
292
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 086: This site is approximately 0.25 acres and consists of former Building 458 (demolished), four
former 1,000-gallon single-wall steel USTs (removed in 1989), and an oil sump in the building's basement
(removed during building demolition). Building 458 is a former engine testing facility (from 1940 to 1972),
with a radioactive instrumentation calibration-repair laboratory (from the early 1960s to the late 1970s) and
a dry-cleaning facility (from 1990 to the early 2000s). A portion of the IWL runs west of Building 458. An
IWL sump was off the north corner of the building and received wastewater from operations at Building
458. Wastewater from building operations discharged to the sump (oil/water separator with a sump) in the
basement. The sump was connected to the IWL. According to the 1997 physical site survey, there were
two floor drains in the basement; however, the exact locations cannot be determined because the building
has been demolished. The four USTs contained waste oil to support jet engine testing operations at Building
458. One of the USTs (Tank 458C) had a significant hole on one side. During the removal of the USTs,
contaminated soil was excavated, and the site was backfilled with clean soil and covered with concrete.
Closure was granted for the four USTs by the Central Valley Water Board in 1996. Releases from the
USTs, the oil sump, and IWL may have impacted the subsurface soil, and releases from activities in building
may have impacted the surface.
Selected Remedies: Alternatives VOC2 (ICs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; TPH and metals in soil
Shallow Soil Gas: SSG risk for unrestricted is 1 x 10~5 (from PCE), which is within the risk management
range. SSG risk for industrial use is 8 x 10"7, which is less than the risk management range. The HI is 12
(from 1,2,4-TMB and 1,3,5-TMB) for unrestricted use and is less than 1 for industrial use. Although the
risk for unrestricted use is within the risk management range, there is uncertainty remaining because SSG
samples were only collected from two locations in the southern portion of SA 086. The COCs identified
in SSG are PCE, benzene, 1,2,4-TMB, and 1,3,5-TMB.
Soil: Soil risk for unrestricted use is 3 x 10~7 and for industrial use is 2 x 10~7, both of which are less than
the risk management range. The HI is 2 (from cadmium) for unrestricted use and is less than 1 for industrial
use. The COC for soil is cadmium.
There are potential impacts to groundwater quality from arsenic, but most arsenic data were obtained with
Method SW6010 and are considered unreliable. Arsenic results from samples analyzed using Method
SW7060 were below background. There are potential impacts to groundwater quality from TPH-D. There
are potential impacts to surface water quality from cadmium and lead.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and S SG is 1 x 10 6 and may be higher when exposure to all pathways,
including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for SA 086 is commercial/industrial.
VOC2 was selected to prevent unrestricted use (the HI for unrestricted use is greater than 1). VOC2 was
selected over VOC3 due to the relatively low risks for industrial use. VOC2 is sufficiently protective and
is more cost effective than VOC3.
Non-VOC2 was selected to prevent unrestricted use (the HI for unrestricted use is greater than 1) and to
address potential impacts to surface water quality using ECs. Alternative Non-VOC2 was selected over
Alternative Non-VOC4b because it is protective of human health and includes ECs that are protective of
surface water quality, will not disrupt current site use, and is more cost effective than Alternate Non-
VOC4b. The ICs and ECs require that if existing surface covers on the site are removed or remodeled,
sampling must be done, as surface cover must be maintained, or other soil/sediment ECs implemented, as
warranted as long as levels protective of surface water quality as shown in Table 2-4 are exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
293
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
S.A081C
Olt iJJMP
M BASFMFNT
3A8SSCQ4
FORMER C«Y CLfcANNC-
OPERATIONS
REPAIR SHOP- FORMER VOCAf ION
NSTR UMENTaTW WQPL IBRATION
PRj/L-004A
SA86SB0C
SA86SG01
APPBOXMATE LCOtflON
OF FORMER USTs
SA66SB03
CS 036
SA86SB01
SA86SB01Q #
SA86MW001
Notes:
Small Volume Sites sample locations are shown in bold
The analytical data for borings shown In gra , can be
found in the OU A RICS (Jacobs, 2001).
Figure D-80 SA 086 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
CH2MHILL
LEGEND
¦ SOIL VAPOR EXTRACT ION WELL INDUSTRIAL WASTE LINES
$ SOIL VAPOR MONITORING WELL ROADS
4> SURFACE SCRAP0SEDIMENT SAMPLE
BUILDINGS
• SHALLOW BORING (0-15 FT BGS)
O MIC TO DEEP BORING (>15 FT BGS) I 1^086
o MANHOLE IC BOUNDARY
m eump
VIGINfTv WP
SA 086
294
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lot Number
| | FOSET #2 Action Site
Roads
Figure D-81 SA 086 IC Compliance
IC Compliance Boundary Boundary Map
Boundary FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
Lot Line
Sacramento, OA
295
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 094: This 2.4 acre site is the location of a former fuel metering station, fuel pipeline, hazardous
waste/material storage area, former motor oil storage shed, and fuel truck parking and maintenance area.
The fuel metering station was in the southeastern corner of SA 094 and operated from 1946 to 1964. The
fuel lines in this area carried jet fuel from the Southern Pacific railroad to the metering station. The fuel
meters were capped and decommissioned in 1979, and this area now consists of an empty asphalt lot. The
fuel truck parking and maintenance area began operations in 1964. It is unknown when these operations
ended. The fuel truck parking and maintenance area contained an asphalt-covered, bermed hazardous
waste/material storage area along the western boundary of SA 094. The hazardous materials storage area
was decommissioned and capped with asphalt and concrete prior to 1979. Releases from spills within the
fuel metering station, hazardous waste/material handling, spills from the suspected motor oil storage shed,
and truck leaks may have impacted the surface soil. Leaking fuel pipelines may have impacted the
subsurface soil. The southern portion of SA 094 was within the former radius of influence of the IC 35
SVE system.
Selected Remedies: Alternatives VOC2 (ICs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; PAHs in soil
Shallow Soil Gas: SSG risk for unrestricted use is 2 * 10~5 (from benzene and naphthalene), which is
within the risk management range. SSG risk for industrial use is 1 x 10"6 (from naphthalene), which is at
the lower end of the risk management range. The HI is less than 1, for both the residential use scenario and
the industrial use scenario. It should be noted that the extent of naphthalene in SSG is uncertain. The COCs
identified in SSG are benzene and naphthalene.
Soil: Soil risk for unrestricted use is 5 x 10~5 (from arsenic and benzo(a)pyrene) and for industrial use is 4
x 10"6 (from arsenic and benzo(a)pyrene), which are both within the risk management range. The HI is less
than 1 for both the unrestricted use scenario and the industrial use scenario. Arsenic is the main driver of
soil risk, but it was detected below background levels.
There are potential impacts to groundwater quality from arsenic; however, arsenic is below the background
level. There are potential impacts to surface water quality from chrysene.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 5 x 10~6 and may be higher when exposure to all pathways,
including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for SA 094 is commercial/industrial.
VOC2 was selected to prevent unrestricted use (due to the uncertainty in the extent of naphthalene). VOC2
was selected over NFA because NFA would not be protective of human health given the uncertainty
regarding the SSG characterization. VOC2 will effectively prevent unrestricted use.
Non-VOC2 was selected to prevent unrestricted use and address potential impacts to surface water quality
using ICs. Non-VOC2 was selected over Non-VOC4a because it is protective of human health and includes
ICs protective of surface water quality, would not disrupt current site use, and is more cost effective than
Non-VOC4a. The ICs and ECs require that if existing surface covers on the site are removed or remodeled,
sampling must be done, as surface cover must be maintained, or other soil/sediment ECs implemented, as
warranted as long as levels protective of surface water quality as shown in Table 2-4 are exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
296
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Pf?L^O30
SA94SB010
SA94HAQ02
EYV-436-.-,
r ^
•
0
C 5 /
. SAS4SG12
/
EW-2SS
E*J '
*L L-OD3A
LOCATION Of- SUSPECT Si
MOTOR OIL STORAGE SHED
MW-329 -
SA94HA01
HAJARfOUS WASTF/MATFRIAt _
{HANDLING AREA3J
TOOL/PARTS TRAILER
PRLS-003
*RL S-002 PRL L 003B/
EW-437 - g
LEGEND
GROUNDWATER MONITORING WELL
fi] GROUNDWATER EXTRACTION WELL
A. SOIL GAS BORING
0 HANDAUGER
• SHALLOW BORING (0-15 FT BGS)
O MID TO DEEP BORING (>15 FT BGS)
< < SUR FACE RUNOFF FLOW DIRECTION
ROADS
1^^300' SVE RADIUS OF INFLUENCE
|SA094
BUILDINGS
FOLLOW-ON STRATEGIC SITES
Notes:
For a complete sel of analytical dala
ro< borings in gray see Draft Operable
Unit B Soli Gas Investigation Dala
Summary 2 (Radian, 1991).
Follow-on Strategic Site. Small Volume
Site, and Soils Data Gap sample locations
are shown hi bow
vtclNitv map-
Figure D-82 SA 094 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
CH2MHILL
297
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lol Number
| | FOSET #2 Action Site
Roads
!C Compliance Boundary
Boundary
Lot Line
0/100 200 300 400 500 A
Feet A
Figure D-83 SA 094 IC Compliance
Boundary Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
298
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 098: This 20,000-square foot site consists of Building 271, where electronic repair, electrical testing,
a spray paint booth, and a solvent spray booth rooms were located. The building was constructed in 1943.
The floor consists of concrete, and no floor drains have been identified. The spray paint and solvent spray
booths operated until 1985. From 1985 to 1991, building materials were stored at the site. The northern
part of the building is currently occupied by Sun Edison, and the southern part is occupied by Silver State
Helicopters Flight Academy. Building 271 is surrounded by asphalt and concrete. Releases from disposal
or spills of materials used in the solvent and spray paint booth may have impacted the surface soil.
Selected Remedy: Alternatives VOC2 (ICs)
Contaminants Addressed: VOCs in SSG
Shallow Soil Gas: SSG risk for unrestricted use is 2 * 10"5 (from benzene, ethylbenzene, naphthalene,
chloroform, naphthalene, TCE, and PCE), which is within the risk management range. SSG risk for
industrial use is 1 x 10"6 (from benzene, ethylbenzene, naphthalene, chloroform, naphthalene, TCE, and
PCE), which is at the low end of the risk management range. The HI is less than 1 for both the unrestricted
use scenario and the industrial use scenario. Although the risk for unrestricted use is within the risk
management range, there is uncertainty remaining because SSG samples were only collected from three
locations in the southern portion of SA 098. The COCs identified in SSG are naphthalene and chloroform.
Soil: Soil risk for unrestricted use is 8 x 10"5 (from arsenic) and for industrial use is 5 x 10"6 (from arsenic),
both of which are within the risk management range. The HI is less than lfor both the unrestricted use
scenario and the industrial use scenario. Arsenic is the main driver of soil risk, but soil concentrations are
below background. Excluding arsenic, soil risks are below the risk management range for unrestricted use
and industrial use. No COCs were identified in soil at SA 098.
There are potential impacts to groundwater quality from arsenic; however, soil concentrations are below
background. Soil data do not indicate potential impacts to surface water.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 6 / 10~6 and may be higher when exposure to all pathways,
including groundwater, are considered.
Rationale for Selected Remedy: The expected future land use for SA 098 is commercial/industrial. VOC2
was selected to prevent unrestricted use (due to uncertainty in characterization of SSG). VOC2 was selected
over VOC3 due to the relatively low risks for industrial use. VOC2 will effectively prevent unrestricted
use.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
299
-------
McClellan FOSET #2 - Group 2 Action Sites ROD Final
CONCRETE
LOADING DOCK v
ROLL-UP DO OR-
SA98SBQ02'
SA 050
SA 048
SA 098
FORMER SOLVENT
PAINT
SPRAY BOOTH
ROLL UP DOOR
SA98SB003
CONCRETE RAMP
/SA 059
LEGEND
A SOIL GAS BORING
• SHALLOW BORING (0-15 FT BGS)
0 TRANSFORMER
ROADS
BUILDINGS
~ SA 098
IC BOUNDARY
VICINITY MAP
SA 098
Figure D-84 SA 098 Site Features Map
FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
30
I
60
I
CH2MHILL
300
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend Figure D-85 SA 098 IC Compliance
200 Lo! Number IC Compliance Boundary Boundary Map
"I FOSET#2 Action Site | | Boundary FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
Roads Lot Line
301
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 101: This 31,000-square foot site consists of the former location of Building T-57, a radiochemical
laboratory that operated from 1943 to 1971, when it was demolished. The building was a semi-permanent
wood structure set on a concrete foundation that was reportedly used as the central kitchen, until World
War II when it was converted into a laboratory. A sump and sump pump were in the southwest corner of
the building. It is unclear if the building or sump drained to the IWL or the sanitary sewer system. The site
is currently an asphalt-paved parking lot. SA 101 was within the former radius of influence of the IC 32
SVE system.
Selected Remedy: Alternative VOC3 (ICs/ECs)
Contaminants Addressed: VOCs in SSG
Shallow Soil Gas: Prior to 2017, only screening-level SSG data are available for SA 101, and none of the
screening-level data contained VOCs at concentrations greater than screening levels. There is uncertainty
regarding SSG characterization, because only two soil gas samples were collected (both at depths of 21.5
feet bgs), and not within 15 feet bgs.
An interim SSG data gap investigation was completed in 2017 to verify the CSM and supporting
information within the Site boundaries and included the collection of two SSG samples at 7 feet bgs.
Chloroform, ethylbenzene, PCE, TCE, 1,2,4-TMB, 1,3,5-TMB, and o-xylene were detected in the 2017
samples, but only chloroform was detected at a concentration above the IC compliance level. Chloroform
was identified as a SSG COC.
Soil: Soil data do not indicate potential impacts to groundwater or surface water quality. No metals were
detected above background levels and no other analytes were detected. No risk values were calculated and
no COCs were identified in soil at SA 101.
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is unable to be calculated.
Rationale for Selected Remedy: The expected future land use for SA 101 is commercial/industrial. VOC3
was to prevent unrestricted use due to chloroform concentrations greater than the IC compliance level and
uncertainty in characterization of SSG of this 31,000 square foot site). VOC3 was selected over NFA
because NFA would not be protective of human health given the SSG uncertainties. VOC3 was selected
over VOC2 because VOC2 may not be protective of industrial users given the uncertainty related to
characterization of SSG and the chloroform concentrations above the IC compliance level. ICs established
by VOC3 will restrict the use of the site and require the installation of ECs in any future buildings or during
significant remodeling of existing buildings to mitigate the potential for VOCs in SSG from migrating into
buildings and impacting occupants via the vapor inhalation pathway. The parcels and lots affected by the
100-foot IC compliance buffer for VOC3 are Parcels A4c, A4d, and B2, Lots 107B, 109, 110, 113A, 114A,
114B, and 209. Soil vapor sampling along the site boundary may be conducted to reduce or modify the
extent of the IC compliance buffer zone.
The selected alternative results in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
302
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
PRL S-023
FORMER LOCATION
OF CHEMICAL
LABORATORY
SA101SB02
SA101SB01
SA101SBQ04"
ASFHALT
PARKING LOT
FORMER LOCATION
OF PUMP/SUMP PUMP
LEGEND
O MID TO DEEP BORING (>15 FT BGS)
ROADS
BUILDINGS
I ISA 101
[C BOUNDARY
CH2MHILL
VICINITY MAP
SA 101
Notes:
The analytical data for borings shown in gray can be
found in the OU A RICS( Jacobs, 2001).
Figure D-86 SA 101 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
_ „
CA
PRLT-018
303
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend
200 Lett Number
I | FOSET #2 Action Site
Roads
Lot Line
IC Compliance Boundary
Figure D-87 SA 101 IC Compliance
Boundary Map
100 Foot VOCsCompliance Buffer FOSET #2 Group 2 Action Sites Record of Decision
Former McClellan Air Force Base, Sacramento, CA
Boundary
S act a me r/to, CA
304
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
SA 102: This 21,000-square foot site is the former location of Building 361, a masonry shack, and an
abandoned bermed washrack. The southeastern side of Building 361 was used as a paint shop, where small
paint jobs were performed on repaired equipment. The southwestern side of the building was used for
vehicle repairs. The north end of Building 361 was used as storage for rigging equipment. The washrack
was used to steam-clean machinery parts, such as gear boxes, and releases during operations at the washrack
may have impacted the surface soil. The section of the IWL under Building 361 was reported in poor
condition prior to repairs in 1988; therefore, potential releases of solvents and wastes discharged to IWL
drains may have impacted the subsurface soil. SA 102 was under the influence of the former IC 31 SVE
system.
Selected Remedies: Alternatives VOC3 (ICs/ECs) and Non-VOC2 (ICs/ECs and Monitoring)
Contaminants Addressed: VOCs in SSG; 2,4-dinitrotoluene and PCBs in soil
Shallow Soil Gas: SSG risk for unrestricted use is 7 * 10"2 (from TCE) and for industrial use is 4 * 10"3
(from TCE), both of which are greater than the risk management range. The HI is 422 (from cis-l,2-DCE,
TCE, and 1,2,4-TMB) for unrestricted use and the HI is 29 (from cis-l,2-DCE, TCE, and 1,2,4-TMB) for
industrial use, both of which are much greater than 1. The COCs identified in SSG are benzene, carbon
tetrachloride, chloroform, cis-l,2-DCE, 1,4-DCB, ethylbenzene, naphthalene, 1,2,4-TMB, 1,3,5-TMB,
m,p-xylene, o-xylene, PCE, and TCE.
Soil: Soil risk for unrestricted use is 2 x 10"4 (from arsenic and 2,4-dinitrotoluene), which is greater than
the risk management range. Soil risk for industrial use is 7 x 10"6, which is within the risk management
range. The HI is 2 (from arsenic and 2,4-dinitrotoluene) for unrestricted use and is less than 1 for industrial
use. Arsenic concentrations detected using Method SW7060 were within the range of background.
Excluding arsenic, soil risks are 6 x 10"5, within the risk management range for unrestricted use, and below
the risk management range for industrial use. Without arsenic, the HI for the residential scenario is less
than 1. The COCs identified in soil at SA 102 are 2,4-dinitrotoluene and PCBs.
Data indicate potential impacts to groundwater quality from arsenic and TPH-G and to surface water quality
from PCBs. TPH-G was detected in a single sample at 3 feet bgs, only slightly exceeded the concentration
for protection of groundwater, and was not detected at 8 feet bgs in the same boring, so it was not identified
as a COC. The arsenic concentrations showing potential impacts to groundwater are below background or
were analyzed using an unreliable analytical method (Method SW6010).
Combined Soil and Shallow Soil Gas Risks: The maximum estimated risk to a commercial/industrial
worker for combined exposure to soil and SSG is 4.01 * 10~3 and may be higher when exposure to all
pathways, including groundwater, are considered.
Rationale for Selected Remedies: The expected future land use for SA 102 is commercial/industrial.
VOC3 was selected to prevent unrestricted use and to require ECs to mitigate SSG for industrial users (SSG
risk for both industrial and unrestricted use is greater than the risk management range and the HI for both
industrial and unrestricted use is greater than 1). VOC3 was selected over VOC2 because VOC2 is not
protective of industrial users given the risk for industrial use is greater than the risk management range and
the HI for industrial use is greater than 1. ICs established by VOC3 will restrict the use of the site and
require the installation of ECs in any future buildings or during significant remodeling of existing buildings
to mitigate the potential for VOCs in SSG from migrating into buildings and impacting occupants via the
vapor inhalation pathway. The parcels and lots affected by the 100-foot IC compliance buffer for VOC3
are Parcels A4d and B2, Lots 101, 104, 108, 114C, and 208. Soil vapor sampling along the site boundary
may be conducted to reduce or modify the extent of the IC compliance buffer zone.
Non-VOC2 was selected to prevent unrestricted use (soil risk for unrestricted use is greater than the risk
management range) and to address potential impacts to surface water using ECs. The ICs and ECs require
that if existing surface covers on the site are removed or remodeled, sampling must be done, as surface
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cover must be maintained, or other soil/sediment ECs implemented, as warranted as long as levels
protective of surface water quality as shown in Table 2-4 are exceeded.
The selected alternatives result in restricted land use with ICs (deed restrictions and SLUCs) prohibiting
residential and other sensitive uses.
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$
LEGEND
¦ DUAL PHASE VAPOR EXTRACTION WELL
¦ SOIL VAPOR EXTRACTION WELL
SOIL VAPOR MONITORING WELL
SURFACE SCRAPE/SEDIMENT SAMPLE
SHALLOW BORING (0-15 FT BGS)
MID TO DEEP BORING (>15 FT BGS)
MANHOLE
LIFT STATION
TRANSFORMER
Notes:
Small Volume Sites boring locations are shown in bold
The analytical data for borings shown in ¦, , can be
found in the OU A RICS (Jacobs, 2001).
INDUSTRIAL WASTE LINES
ROADS
| | SA102
IC BOUNDARY
BUILDINGS
JVti
Figure D-88 SA 102 Site Features Map
FOSET #2 Group 2 Action Sites Record of
Decision
Former McClellan Air Force Base, Sacramento,
CA
CH2MHILL
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McClellan FOSET #2 - Group 2 Action Sites ROD Final
Legend Figure D-89 SA 102 IC Compliance
200 Lot Number IC Compliance Boun BoiUld&ry M&p
1 1 F0SET #2 ^ion Site I i Boundary FOSET #2 Group 2 Action Sites Record of
100 Foot VOCs Compliance Buffer Lot Line Decision
Former McClellan Air Force Base, Sacramento, CA
Roads
Wyrtlia
Ava
Winona Way
Y\
A \
117A
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